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1/*
2 * linux/mm/page_alloc.c
3 *
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
6 *
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
15 */
16
17#include <linux/stddef.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/interrupt.h>
21#include <linux/pagemap.h>
22#include <linux/jiffies.h>
23#include <linux/bootmem.h>
24#include <linux/memblock.h>
25#include <linux/compiler.h>
26#include <linux/kernel.h>
27#include <linux/kasan.h>
28#include <linux/module.h>
29#include <linux/suspend.h>
30#include <linux/pagevec.h>
31#include <linux/blkdev.h>
32#include <linux/slab.h>
33#include <linux/ratelimit.h>
34#include <linux/oom.h>
35#include <linux/notifier.h>
36#include <linux/topology.h>
37#include <linux/sysctl.h>
38#include <linux/cpu.h>
39#include <linux/cpuset.h>
40#include <linux/memory_hotplug.h>
41#include <linux/nodemask.h>
42#include <linux/vmalloc.h>
43#include <linux/vmstat.h>
44#include <linux/mempolicy.h>
45#include <linux/memremap.h>
46#include <linux/stop_machine.h>
47#include <linux/sort.h>
48#include <linux/pfn.h>
49#include <linux/backing-dev.h>
50#include <linux/fault-inject.h>
51#include <linux/page-isolation.h>
52#include <linux/page_ext.h>
53#include <linux/debugobjects.h>
54#include <linux/kmemleak.h>
55#include <linux/compaction.h>
56#include <trace/events/kmem.h>
57#include <trace/events/oom.h>
58#include <linux/prefetch.h>
59#include <linux/mm_inline.h>
60#include <linux/migrate.h>
61#include <linux/hugetlb.h>
62#include <linux/sched/rt.h>
63#include <linux/sched/mm.h>
64#include <linux/page_owner.h>
65#include <linux/kthread.h>
66#include <linux/memcontrol.h>
67#include <linux/ftrace.h>
68#include <linux/lockdep.h>
69#include <linux/nmi.h>
70
71#include <asm/sections.h>
72#include <asm/tlbflush.h>
73#include <asm/div64.h>
74#include "internal.h"
75
76/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
77static DEFINE_MUTEX(pcp_batch_high_lock);
78#define MIN_PERCPU_PAGELIST_FRACTION (8)
79
80#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
81DEFINE_PER_CPU(int, numa_node);
82EXPORT_PER_CPU_SYMBOL(numa_node);
83#endif
84
85DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
86
87#ifdef CONFIG_HAVE_MEMORYLESS_NODES
88/*
89 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
90 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
91 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
92 * defined in <linux/topology.h>.
93 */
94DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
95EXPORT_PER_CPU_SYMBOL(_numa_mem_);
96int _node_numa_mem_[MAX_NUMNODES];
97#endif
98
99/* work_structs for global per-cpu drains */
100DEFINE_MUTEX(pcpu_drain_mutex);
101DEFINE_PER_CPU(struct work_struct, pcpu_drain);
102
103#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
104volatile unsigned long latent_entropy __latent_entropy;
105EXPORT_SYMBOL(latent_entropy);
106#endif
107
108/*
109 * Array of node states.
110 */
111nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
112 [N_POSSIBLE] = NODE_MASK_ALL,
113 [N_ONLINE] = { { [0] = 1UL } },
114#ifndef CONFIG_NUMA
115 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
116#ifdef CONFIG_HIGHMEM
117 [N_HIGH_MEMORY] = { { [0] = 1UL } },
118#endif
119 [N_MEMORY] = { { [0] = 1UL } },
120 [N_CPU] = { { [0] = 1UL } },
121#endif /* NUMA */
122};
123EXPORT_SYMBOL(node_states);
124
125/* Protect totalram_pages and zone->managed_pages */
126static DEFINE_SPINLOCK(managed_page_count_lock);
127
128unsigned long totalram_pages __read_mostly;
129unsigned long totalreserve_pages __read_mostly;
130unsigned long totalcma_pages __read_mostly;
131
132int percpu_pagelist_fraction;
133gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
134
135/*
136 * A cached value of the page's pageblock's migratetype, used when the page is
137 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
138 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
139 * Also the migratetype set in the page does not necessarily match the pcplist
140 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
141 * other index - this ensures that it will be put on the correct CMA freelist.
142 */
143static inline int get_pcppage_migratetype(struct page *page)
144{
145 return page->index;
146}
147
148static inline void set_pcppage_migratetype(struct page *page, int migratetype)
149{
150 page->index = migratetype;
151}
152
153#ifdef CONFIG_PM_SLEEP
154/*
155 * The following functions are used by the suspend/hibernate code to temporarily
156 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
157 * while devices are suspended. To avoid races with the suspend/hibernate code,
158 * they should always be called with pm_mutex held (gfp_allowed_mask also should
159 * only be modified with pm_mutex held, unless the suspend/hibernate code is
160 * guaranteed not to run in parallel with that modification).
161 */
162
163static gfp_t saved_gfp_mask;
164
165void pm_restore_gfp_mask(void)
166{
167 WARN_ON(!mutex_is_locked(&pm_mutex));
168 if (saved_gfp_mask) {
169 gfp_allowed_mask = saved_gfp_mask;
170 saved_gfp_mask = 0;
171 }
172}
173
174void pm_restrict_gfp_mask(void)
175{
176 WARN_ON(!mutex_is_locked(&pm_mutex));
177 WARN_ON(saved_gfp_mask);
178 saved_gfp_mask = gfp_allowed_mask;
179 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
180}
181
182bool pm_suspended_storage(void)
183{
184 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
185 return false;
186 return true;
187}
188#endif /* CONFIG_PM_SLEEP */
189
190#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
191unsigned int pageblock_order __read_mostly;
192#endif
193
194static void __free_pages_ok(struct page *page, unsigned int order);
195
196/*
197 * results with 256, 32 in the lowmem_reserve sysctl:
198 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
199 * 1G machine -> (16M dma, 784M normal, 224M high)
200 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
201 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
202 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
203 *
204 * TBD: should special case ZONE_DMA32 machines here - in those we normally
205 * don't need any ZONE_NORMAL reservation
206 */
207int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
208#ifdef CONFIG_ZONE_DMA
209 [ZONE_DMA] = 256,
210#endif
211#ifdef CONFIG_ZONE_DMA32
212 [ZONE_DMA32] = 256,
213#endif
214 [ZONE_NORMAL] = 32,
215#ifdef CONFIG_HIGHMEM
216 [ZONE_HIGHMEM] = 0,
217#endif
218 [ZONE_MOVABLE] = 0,
219};
220
221EXPORT_SYMBOL(totalram_pages);
222
223static char * const zone_names[MAX_NR_ZONES] = {
224#ifdef CONFIG_ZONE_DMA
225 "DMA",
226#endif
227#ifdef CONFIG_ZONE_DMA32
228 "DMA32",
229#endif
230 "Normal",
231#ifdef CONFIG_HIGHMEM
232 "HighMem",
233#endif
234 "Movable",
235#ifdef CONFIG_ZONE_DEVICE
236 "Device",
237#endif
238};
239
240char * const migratetype_names[MIGRATE_TYPES] = {
241 "Unmovable",
242 "Movable",
243 "Reclaimable",
244 "HighAtomic",
245#ifdef CONFIG_CMA
246 "CMA",
247#endif
248#ifdef CONFIG_MEMORY_ISOLATION
249 "Isolate",
250#endif
251};
252
253compound_page_dtor * const compound_page_dtors[] = {
254 NULL,
255 free_compound_page,
256#ifdef CONFIG_HUGETLB_PAGE
257 free_huge_page,
258#endif
259#ifdef CONFIG_TRANSPARENT_HUGEPAGE
260 free_transhuge_page,
261#endif
262};
263
264int min_free_kbytes = 1024;
265int user_min_free_kbytes = -1;
266int watermark_scale_factor = 10;
267
268static unsigned long nr_kernel_pages __meminitdata;
269static unsigned long nr_all_pages __meminitdata;
270static unsigned long dma_reserve __meminitdata;
271
272#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
273static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __meminitdata;
274static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __meminitdata;
275static unsigned long required_kernelcore __initdata;
276static unsigned long required_kernelcore_percent __initdata;
277static unsigned long required_movablecore __initdata;
278static unsigned long required_movablecore_percent __initdata;
279static unsigned long zone_movable_pfn[MAX_NUMNODES] __meminitdata;
280static bool mirrored_kernelcore __meminitdata;
281
282/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
283int movable_zone;
284EXPORT_SYMBOL(movable_zone);
285#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
286
287#if MAX_NUMNODES > 1
288int nr_node_ids __read_mostly = MAX_NUMNODES;
289int nr_online_nodes __read_mostly = 1;
290EXPORT_SYMBOL(nr_node_ids);
291EXPORT_SYMBOL(nr_online_nodes);
292#endif
293
294int page_group_by_mobility_disabled __read_mostly;
295
296#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
297/* Returns true if the struct page for the pfn is uninitialised */
298static inline bool __meminit early_page_uninitialised(unsigned long pfn)
299{
300 int nid = early_pfn_to_nid(pfn);
301
302 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
303 return true;
304
305 return false;
306}
307
308/*
309 * Returns false when the remaining initialisation should be deferred until
310 * later in the boot cycle when it can be parallelised.
311 */
312static inline bool update_defer_init(pg_data_t *pgdat,
313 unsigned long pfn, unsigned long zone_end,
314 unsigned long *nr_initialised)
315{
316 /* Always populate low zones for address-constrained allocations */
317 if (zone_end < pgdat_end_pfn(pgdat))
318 return true;
319 (*nr_initialised)++;
320 if ((*nr_initialised > pgdat->static_init_pgcnt) &&
321 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
322 pgdat->first_deferred_pfn = pfn;
323 return false;
324 }
325
326 return true;
327}
328#else
329static inline bool early_page_uninitialised(unsigned long pfn)
330{
331 return false;
332}
333
334static inline bool update_defer_init(pg_data_t *pgdat,
335 unsigned long pfn, unsigned long zone_end,
336 unsigned long *nr_initialised)
337{
338 return true;
339}
340#endif
341
342/* Return a pointer to the bitmap storing bits affecting a block of pages */
343static inline unsigned long *get_pageblock_bitmap(struct page *page,
344 unsigned long pfn)
345{
346#ifdef CONFIG_SPARSEMEM
347 return __pfn_to_section(pfn)->pageblock_flags;
348#else
349 return page_zone(page)->pageblock_flags;
350#endif /* CONFIG_SPARSEMEM */
351}
352
353static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
354{
355#ifdef CONFIG_SPARSEMEM
356 pfn &= (PAGES_PER_SECTION-1);
357 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
358#else
359 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
360 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
361#endif /* CONFIG_SPARSEMEM */
362}
363
364/**
365 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
366 * @page: The page within the block of interest
367 * @pfn: The target page frame number
368 * @end_bitidx: The last bit of interest to retrieve
369 * @mask: mask of bits that the caller is interested in
370 *
371 * Return: pageblock_bits flags
372 */
373static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
374 unsigned long pfn,
375 unsigned long end_bitidx,
376 unsigned long mask)
377{
378 unsigned long *bitmap;
379 unsigned long bitidx, word_bitidx;
380 unsigned long word;
381
382 bitmap = get_pageblock_bitmap(page, pfn);
383 bitidx = pfn_to_bitidx(page, pfn);
384 word_bitidx = bitidx / BITS_PER_LONG;
385 bitidx &= (BITS_PER_LONG-1);
386
387 word = bitmap[word_bitidx];
388 bitidx += end_bitidx;
389 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
390}
391
392unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
393 unsigned long end_bitidx,
394 unsigned long mask)
395{
396 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
397}
398
399static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
400{
401 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
402}
403
404/**
405 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
406 * @page: The page within the block of interest
407 * @flags: The flags to set
408 * @pfn: The target page frame number
409 * @end_bitidx: The last bit of interest
410 * @mask: mask of bits that the caller is interested in
411 */
412void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
413 unsigned long pfn,
414 unsigned long end_bitidx,
415 unsigned long mask)
416{
417 unsigned long *bitmap;
418 unsigned long bitidx, word_bitidx;
419 unsigned long old_word, word;
420
421 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
422
423 bitmap = get_pageblock_bitmap(page, pfn);
424 bitidx = pfn_to_bitidx(page, pfn);
425 word_bitidx = bitidx / BITS_PER_LONG;
426 bitidx &= (BITS_PER_LONG-1);
427
428 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
429
430 bitidx += end_bitidx;
431 mask <<= (BITS_PER_LONG - bitidx - 1);
432 flags <<= (BITS_PER_LONG - bitidx - 1);
433
434 word = READ_ONCE(bitmap[word_bitidx]);
435 for (;;) {
436 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
437 if (word == old_word)
438 break;
439 word = old_word;
440 }
441}
442
443void set_pageblock_migratetype(struct page *page, int migratetype)
444{
445 if (unlikely(page_group_by_mobility_disabled &&
446 migratetype < MIGRATE_PCPTYPES))
447 migratetype = MIGRATE_UNMOVABLE;
448
449 set_pageblock_flags_group(page, (unsigned long)migratetype,
450 PB_migrate, PB_migrate_end);
451}
452
453#ifdef CONFIG_DEBUG_VM
454static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
455{
456 int ret = 0;
457 unsigned seq;
458 unsigned long pfn = page_to_pfn(page);
459 unsigned long sp, start_pfn;
460
461 do {
462 seq = zone_span_seqbegin(zone);
463 start_pfn = zone->zone_start_pfn;
464 sp = zone->spanned_pages;
465 if (!zone_spans_pfn(zone, pfn))
466 ret = 1;
467 } while (zone_span_seqretry(zone, seq));
468
469 if (ret)
470 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
471 pfn, zone_to_nid(zone), zone->name,
472 start_pfn, start_pfn + sp);
473
474 return ret;
475}
476
477static int page_is_consistent(struct zone *zone, struct page *page)
478{
479 if (!pfn_valid_within(page_to_pfn(page)))
480 return 0;
481 if (zone != page_zone(page))
482 return 0;
483
484 return 1;
485}
486/*
487 * Temporary debugging check for pages not lying within a given zone.
488 */
489static int __maybe_unused bad_range(struct zone *zone, struct page *page)
490{
491 if (page_outside_zone_boundaries(zone, page))
492 return 1;
493 if (!page_is_consistent(zone, page))
494 return 1;
495
496 return 0;
497}
498#else
499static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
500{
501 return 0;
502}
503#endif
504
505static void bad_page(struct page *page, const char *reason,
506 unsigned long bad_flags)
507{
508 static unsigned long resume;
509 static unsigned long nr_shown;
510 static unsigned long nr_unshown;
511
512 /*
513 * Allow a burst of 60 reports, then keep quiet for that minute;
514 * or allow a steady drip of one report per second.
515 */
516 if (nr_shown == 60) {
517 if (time_before(jiffies, resume)) {
518 nr_unshown++;
519 goto out;
520 }
521 if (nr_unshown) {
522 pr_alert(
523 "BUG: Bad page state: %lu messages suppressed\n",
524 nr_unshown);
525 nr_unshown = 0;
526 }
527 nr_shown = 0;
528 }
529 if (nr_shown++ == 0)
530 resume = jiffies + 60 * HZ;
531
532 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
533 current->comm, page_to_pfn(page));
534 __dump_page(page, reason);
535 bad_flags &= page->flags;
536 if (bad_flags)
537 pr_alert("bad because of flags: %#lx(%pGp)\n",
538 bad_flags, &bad_flags);
539 dump_page_owner(page);
540
541 print_modules();
542 dump_stack();
543out:
544 /* Leave bad fields for debug, except PageBuddy could make trouble */
545 page_mapcount_reset(page); /* remove PageBuddy */
546 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
547}
548
549/*
550 * Higher-order pages are called "compound pages". They are structured thusly:
551 *
552 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
553 *
554 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
555 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
556 *
557 * The first tail page's ->compound_dtor holds the offset in array of compound
558 * page destructors. See compound_page_dtors.
559 *
560 * The first tail page's ->compound_order holds the order of allocation.
561 * This usage means that zero-order pages may not be compound.
562 */
563
564void free_compound_page(struct page *page)
565{
566 __free_pages_ok(page, compound_order(page));
567}
568
569void prep_compound_page(struct page *page, unsigned int order)
570{
571 int i;
572 int nr_pages = 1 << order;
573
574 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
575 set_compound_order(page, order);
576 __SetPageHead(page);
577 for (i = 1; i < nr_pages; i++) {
578 struct page *p = page + i;
579 set_page_count(p, 0);
580 p->mapping = TAIL_MAPPING;
581 set_compound_head(p, page);
582 }
583 atomic_set(compound_mapcount_ptr(page), -1);
584}
585
586#ifdef CONFIG_DEBUG_PAGEALLOC
587unsigned int _debug_guardpage_minorder;
588bool _debug_pagealloc_enabled __read_mostly
589 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
590EXPORT_SYMBOL(_debug_pagealloc_enabled);
591bool _debug_guardpage_enabled __read_mostly;
592
593static int __init early_debug_pagealloc(char *buf)
594{
595 if (!buf)
596 return -EINVAL;
597 return kstrtobool(buf, &_debug_pagealloc_enabled);
598}
599early_param("debug_pagealloc", early_debug_pagealloc);
600
601static bool need_debug_guardpage(void)
602{
603 /* If we don't use debug_pagealloc, we don't need guard page */
604 if (!debug_pagealloc_enabled())
605 return false;
606
607 if (!debug_guardpage_minorder())
608 return false;
609
610 return true;
611}
612
613static void init_debug_guardpage(void)
614{
615 if (!debug_pagealloc_enabled())
616 return;
617
618 if (!debug_guardpage_minorder())
619 return;
620
621 _debug_guardpage_enabled = true;
622}
623
624struct page_ext_operations debug_guardpage_ops = {
625 .need = need_debug_guardpage,
626 .init = init_debug_guardpage,
627};
628
629static int __init debug_guardpage_minorder_setup(char *buf)
630{
631 unsigned long res;
632
633 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
634 pr_err("Bad debug_guardpage_minorder value\n");
635 return 0;
636 }
637 _debug_guardpage_minorder = res;
638 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
639 return 0;
640}
641early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
642
643static inline bool set_page_guard(struct zone *zone, struct page *page,
644 unsigned int order, int migratetype)
645{
646 struct page_ext *page_ext;
647
648 if (!debug_guardpage_enabled())
649 return false;
650
651 if (order >= debug_guardpage_minorder())
652 return false;
653
654 page_ext = lookup_page_ext(page);
655 if (unlikely(!page_ext))
656 return false;
657
658 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
659
660 INIT_LIST_HEAD(&page->lru);
661 set_page_private(page, order);
662 /* Guard pages are not available for any usage */
663 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
664
665 return true;
666}
667
668static inline void clear_page_guard(struct zone *zone, struct page *page,
669 unsigned int order, int migratetype)
670{
671 struct page_ext *page_ext;
672
673 if (!debug_guardpage_enabled())
674 return;
675
676 page_ext = lookup_page_ext(page);
677 if (unlikely(!page_ext))
678 return;
679
680 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
681
682 set_page_private(page, 0);
683 if (!is_migrate_isolate(migratetype))
684 __mod_zone_freepage_state(zone, (1 << order), migratetype);
685}
686#else
687struct page_ext_operations debug_guardpage_ops;
688static inline bool set_page_guard(struct zone *zone, struct page *page,
689 unsigned int order, int migratetype) { return false; }
690static inline void clear_page_guard(struct zone *zone, struct page *page,
691 unsigned int order, int migratetype) {}
692#endif
693
694static inline void set_page_order(struct page *page, unsigned int order)
695{
696 set_page_private(page, order);
697 __SetPageBuddy(page);
698}
699
700static inline void rmv_page_order(struct page *page)
701{
702 __ClearPageBuddy(page);
703 set_page_private(page, 0);
704}
705
706/*
707 * This function checks whether a page is free && is the buddy
708 * we can do coalesce a page and its buddy if
709 * (a) the buddy is not in a hole (check before calling!) &&
710 * (b) the buddy is in the buddy system &&
711 * (c) a page and its buddy have the same order &&
712 * (d) a page and its buddy are in the same zone.
713 *
714 * For recording whether a page is in the buddy system, we set ->_mapcount
715 * PAGE_BUDDY_MAPCOUNT_VALUE.
716 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
717 * serialized by zone->lock.
718 *
719 * For recording page's order, we use page_private(page).
720 */
721static inline int page_is_buddy(struct page *page, struct page *buddy,
722 unsigned int order)
723{
724 if (page_is_guard(buddy) && page_order(buddy) == order) {
725 if (page_zone_id(page) != page_zone_id(buddy))
726 return 0;
727
728 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
729
730 return 1;
731 }
732
733 if (PageBuddy(buddy) && page_order(buddy) == order) {
734 /*
735 * zone check is done late to avoid uselessly
736 * calculating zone/node ids for pages that could
737 * never merge.
738 */
739 if (page_zone_id(page) != page_zone_id(buddy))
740 return 0;
741
742 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
743
744 return 1;
745 }
746 return 0;
747}
748
749/*
750 * Freeing function for a buddy system allocator.
751 *
752 * The concept of a buddy system is to maintain direct-mapped table
753 * (containing bit values) for memory blocks of various "orders".
754 * The bottom level table contains the map for the smallest allocatable
755 * units of memory (here, pages), and each level above it describes
756 * pairs of units from the levels below, hence, "buddies".
757 * At a high level, all that happens here is marking the table entry
758 * at the bottom level available, and propagating the changes upward
759 * as necessary, plus some accounting needed to play nicely with other
760 * parts of the VM system.
761 * At each level, we keep a list of pages, which are heads of continuous
762 * free pages of length of (1 << order) and marked with _mapcount
763 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
764 * field.
765 * So when we are allocating or freeing one, we can derive the state of the
766 * other. That is, if we allocate a small block, and both were
767 * free, the remainder of the region must be split into blocks.
768 * If a block is freed, and its buddy is also free, then this
769 * triggers coalescing into a block of larger size.
770 *
771 * -- nyc
772 */
773
774static inline void __free_one_page(struct page *page,
775 unsigned long pfn,
776 struct zone *zone, unsigned int order,
777 int migratetype)
778{
779 unsigned long combined_pfn;
780 unsigned long uninitialized_var(buddy_pfn);
781 struct page *buddy;
782 unsigned int max_order;
783
784 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
785
786 VM_BUG_ON(!zone_is_initialized(zone));
787 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
788
789 VM_BUG_ON(migratetype == -1);
790 if (likely(!is_migrate_isolate(migratetype)))
791 __mod_zone_freepage_state(zone, 1 << order, migratetype);
792
793 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
794 VM_BUG_ON_PAGE(bad_range(zone, page), page);
795
796continue_merging:
797 while (order < max_order - 1) {
798 buddy_pfn = __find_buddy_pfn(pfn, order);
799 buddy = page + (buddy_pfn - pfn);
800
801 if (!pfn_valid_within(buddy_pfn))
802 goto done_merging;
803 if (!page_is_buddy(page, buddy, order))
804 goto done_merging;
805 /*
806 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
807 * merge with it and move up one order.
808 */
809 if (page_is_guard(buddy)) {
810 clear_page_guard(zone, buddy, order, migratetype);
811 } else {
812 list_del(&buddy->lru);
813 zone->free_area[order].nr_free--;
814 rmv_page_order(buddy);
815 }
816 combined_pfn = buddy_pfn & pfn;
817 page = page + (combined_pfn - pfn);
818 pfn = combined_pfn;
819 order++;
820 }
821 if (max_order < MAX_ORDER) {
822 /* If we are here, it means order is >= pageblock_order.
823 * We want to prevent merge between freepages on isolate
824 * pageblock and normal pageblock. Without this, pageblock
825 * isolation could cause incorrect freepage or CMA accounting.
826 *
827 * We don't want to hit this code for the more frequent
828 * low-order merging.
829 */
830 if (unlikely(has_isolate_pageblock(zone))) {
831 int buddy_mt;
832
833 buddy_pfn = __find_buddy_pfn(pfn, order);
834 buddy = page + (buddy_pfn - pfn);
835 buddy_mt = get_pageblock_migratetype(buddy);
836
837 if (migratetype != buddy_mt
838 && (is_migrate_isolate(migratetype) ||
839 is_migrate_isolate(buddy_mt)))
840 goto done_merging;
841 }
842 max_order++;
843 goto continue_merging;
844 }
845
846done_merging:
847 set_page_order(page, order);
848
849 /*
850 * If this is not the largest possible page, check if the buddy
851 * of the next-highest order is free. If it is, it's possible
852 * that pages are being freed that will coalesce soon. In case,
853 * that is happening, add the free page to the tail of the list
854 * so it's less likely to be used soon and more likely to be merged
855 * as a higher order page
856 */
857 if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) {
858 struct page *higher_page, *higher_buddy;
859 combined_pfn = buddy_pfn & pfn;
860 higher_page = page + (combined_pfn - pfn);
861 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
862 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
863 if (pfn_valid_within(buddy_pfn) &&
864 page_is_buddy(higher_page, higher_buddy, order + 1)) {
865 list_add_tail(&page->lru,
866 &zone->free_area[order].free_list[migratetype]);
867 goto out;
868 }
869 }
870
871 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
872out:
873 zone->free_area[order].nr_free++;
874}
875
876/*
877 * A bad page could be due to a number of fields. Instead of multiple branches,
878 * try and check multiple fields with one check. The caller must do a detailed
879 * check if necessary.
880 */
881static inline bool page_expected_state(struct page *page,
882 unsigned long check_flags)
883{
884 if (unlikely(atomic_read(&page->_mapcount) != -1))
885 return false;
886
887 if (unlikely((unsigned long)page->mapping |
888 page_ref_count(page) |
889#ifdef CONFIG_MEMCG
890 (unsigned long)page->mem_cgroup |
891#endif
892 (page->flags & check_flags)))
893 return false;
894
895 return true;
896}
897
898static void free_pages_check_bad(struct page *page)
899{
900 const char *bad_reason;
901 unsigned long bad_flags;
902
903 bad_reason = NULL;
904 bad_flags = 0;
905
906 if (unlikely(atomic_read(&page->_mapcount) != -1))
907 bad_reason = "nonzero mapcount";
908 if (unlikely(page->mapping != NULL))
909 bad_reason = "non-NULL mapping";
910 if (unlikely(page_ref_count(page) != 0))
911 bad_reason = "nonzero _refcount";
912 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
913 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
914 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
915 }
916#ifdef CONFIG_MEMCG
917 if (unlikely(page->mem_cgroup))
918 bad_reason = "page still charged to cgroup";
919#endif
920 bad_page(page, bad_reason, bad_flags);
921}
922
923static inline int free_pages_check(struct page *page)
924{
925 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
926 return 0;
927
928 /* Something has gone sideways, find it */
929 free_pages_check_bad(page);
930 return 1;
931}
932
933static int free_tail_pages_check(struct page *head_page, struct page *page)
934{
935 int ret = 1;
936
937 /*
938 * We rely page->lru.next never has bit 0 set, unless the page
939 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
940 */
941 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
942
943 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
944 ret = 0;
945 goto out;
946 }
947 switch (page - head_page) {
948 case 1:
949 /* the first tail page: ->mapping is compound_mapcount() */
950 if (unlikely(compound_mapcount(page))) {
951 bad_page(page, "nonzero compound_mapcount", 0);
952 goto out;
953 }
954 break;
955 case 2:
956 /*
957 * the second tail page: ->mapping is
958 * page_deferred_list().next -- ignore value.
959 */
960 break;
961 default:
962 if (page->mapping != TAIL_MAPPING) {
963 bad_page(page, "corrupted mapping in tail page", 0);
964 goto out;
965 }
966 break;
967 }
968 if (unlikely(!PageTail(page))) {
969 bad_page(page, "PageTail not set", 0);
970 goto out;
971 }
972 if (unlikely(compound_head(page) != head_page)) {
973 bad_page(page, "compound_head not consistent", 0);
974 goto out;
975 }
976 ret = 0;
977out:
978 page->mapping = NULL;
979 clear_compound_head(page);
980 return ret;
981}
982
983static __always_inline bool free_pages_prepare(struct page *page,
984 unsigned int order, bool check_free)
985{
986 int bad = 0;
987
988 VM_BUG_ON_PAGE(PageTail(page), page);
989
990 trace_mm_page_free(page, order);
991
992 /*
993 * Check tail pages before head page information is cleared to
994 * avoid checking PageCompound for order-0 pages.
995 */
996 if (unlikely(order)) {
997 bool compound = PageCompound(page);
998 int i;
999
1000 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1001
1002 if (compound)
1003 ClearPageDoubleMap(page);
1004 for (i = 1; i < (1 << order); i++) {
1005 if (compound)
1006 bad += free_tail_pages_check(page, page + i);
1007 if (unlikely(free_pages_check(page + i))) {
1008 bad++;
1009 continue;
1010 }
1011 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1012 }
1013 }
1014 if (PageMappingFlags(page))
1015 page->mapping = NULL;
1016 if (memcg_kmem_enabled() && PageKmemcg(page))
1017 memcg_kmem_uncharge(page, order);
1018 if (check_free)
1019 bad += free_pages_check(page);
1020 if (bad)
1021 return false;
1022
1023 page_cpupid_reset_last(page);
1024 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1025 reset_page_owner(page, order);
1026
1027 if (!PageHighMem(page)) {
1028 debug_check_no_locks_freed(page_address(page),
1029 PAGE_SIZE << order);
1030 debug_check_no_obj_freed(page_address(page),
1031 PAGE_SIZE << order);
1032 }
1033 arch_free_page(page, order);
1034 kernel_poison_pages(page, 1 << order, 0);
1035 kernel_map_pages(page, 1 << order, 0);
1036 kasan_free_pages(page, order);
1037
1038 return true;
1039}
1040
1041#ifdef CONFIG_DEBUG_VM
1042static inline bool free_pcp_prepare(struct page *page)
1043{
1044 return free_pages_prepare(page, 0, true);
1045}
1046
1047static inline bool bulkfree_pcp_prepare(struct page *page)
1048{
1049 return false;
1050}
1051#else
1052static bool free_pcp_prepare(struct page *page)
1053{
1054 return free_pages_prepare(page, 0, false);
1055}
1056
1057static bool bulkfree_pcp_prepare(struct page *page)
1058{
1059 return free_pages_check(page);
1060}
1061#endif /* CONFIG_DEBUG_VM */
1062
1063static inline void prefetch_buddy(struct page *page)
1064{
1065 unsigned long pfn = page_to_pfn(page);
1066 unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0);
1067 struct page *buddy = page + (buddy_pfn - pfn);
1068
1069 prefetch(buddy);
1070}
1071
1072/*
1073 * Frees a number of pages from the PCP lists
1074 * Assumes all pages on list are in same zone, and of same order.
1075 * count is the number of pages to free.
1076 *
1077 * If the zone was previously in an "all pages pinned" state then look to
1078 * see if this freeing clears that state.
1079 *
1080 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1081 * pinned" detection logic.
1082 */
1083static void free_pcppages_bulk(struct zone *zone, int count,
1084 struct per_cpu_pages *pcp)
1085{
1086 int migratetype = 0;
1087 int batch_free = 0;
1088 int prefetch_nr = 0;
1089 bool isolated_pageblocks;
1090 struct page *page, *tmp;
1091 LIST_HEAD(head);
1092
1093 while (count) {
1094 struct list_head *list;
1095
1096 /*
1097 * Remove pages from lists in a round-robin fashion. A
1098 * batch_free count is maintained that is incremented when an
1099 * empty list is encountered. This is so more pages are freed
1100 * off fuller lists instead of spinning excessively around empty
1101 * lists
1102 */
1103 do {
1104 batch_free++;
1105 if (++migratetype == MIGRATE_PCPTYPES)
1106 migratetype = 0;
1107 list = &pcp->lists[migratetype];
1108 } while (list_empty(list));
1109
1110 /* This is the only non-empty list. Free them all. */
1111 if (batch_free == MIGRATE_PCPTYPES)
1112 batch_free = count;
1113
1114 do {
1115 page = list_last_entry(list, struct page, lru);
1116 /* must delete to avoid corrupting pcp list */
1117 list_del(&page->lru);
1118 pcp->count--;
1119
1120 if (bulkfree_pcp_prepare(page))
1121 continue;
1122
1123 list_add_tail(&page->lru, &head);
1124
1125 /*
1126 * We are going to put the page back to the global
1127 * pool, prefetch its buddy to speed up later access
1128 * under zone->lock. It is believed the overhead of
1129 * an additional test and calculating buddy_pfn here
1130 * can be offset by reduced memory latency later. To
1131 * avoid excessive prefetching due to large count, only
1132 * prefetch buddy for the first pcp->batch nr of pages.
1133 */
1134 if (prefetch_nr++ < pcp->batch)
1135 prefetch_buddy(page);
1136 } while (--count && --batch_free && !list_empty(list));
1137 }
1138
1139 spin_lock(&zone->lock);
1140 isolated_pageblocks = has_isolate_pageblock(zone);
1141
1142 /*
1143 * Use safe version since after __free_one_page(),
1144 * page->lru.next will not point to original list.
1145 */
1146 list_for_each_entry_safe(page, tmp, &head, lru) {
1147 int mt = get_pcppage_migratetype(page);
1148 /* MIGRATE_ISOLATE page should not go to pcplists */
1149 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1150 /* Pageblock could have been isolated meanwhile */
1151 if (unlikely(isolated_pageblocks))
1152 mt = get_pageblock_migratetype(page);
1153
1154 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1155 trace_mm_page_pcpu_drain(page, 0, mt);
1156 }
1157 spin_unlock(&zone->lock);
1158}
1159
1160static void free_one_page(struct zone *zone,
1161 struct page *page, unsigned long pfn,
1162 unsigned int order,
1163 int migratetype)
1164{
1165 spin_lock(&zone->lock);
1166 if (unlikely(has_isolate_pageblock(zone) ||
1167 is_migrate_isolate(migratetype))) {
1168 migratetype = get_pfnblock_migratetype(page, pfn);
1169 }
1170 __free_one_page(page, pfn, zone, order, migratetype);
1171 spin_unlock(&zone->lock);
1172}
1173
1174static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1175 unsigned long zone, int nid)
1176{
1177 mm_zero_struct_page(page);
1178 set_page_links(page, zone, nid, pfn);
1179 init_page_count(page);
1180 page_mapcount_reset(page);
1181 page_cpupid_reset_last(page);
1182
1183 INIT_LIST_HEAD(&page->lru);
1184#ifdef WANT_PAGE_VIRTUAL
1185 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1186 if (!is_highmem_idx(zone))
1187 set_page_address(page, __va(pfn << PAGE_SHIFT));
1188#endif
1189}
1190
1191#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1192static void __meminit init_reserved_page(unsigned long pfn)
1193{
1194 pg_data_t *pgdat;
1195 int nid, zid;
1196
1197 if (!early_page_uninitialised(pfn))
1198 return;
1199
1200 nid = early_pfn_to_nid(pfn);
1201 pgdat = NODE_DATA(nid);
1202
1203 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1204 struct zone *zone = &pgdat->node_zones[zid];
1205
1206 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1207 break;
1208 }
1209 __init_single_page(pfn_to_page(pfn), pfn, zid, nid);
1210}
1211#else
1212static inline void init_reserved_page(unsigned long pfn)
1213{
1214}
1215#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1216
1217/*
1218 * Initialised pages do not have PageReserved set. This function is
1219 * called for each range allocated by the bootmem allocator and
1220 * marks the pages PageReserved. The remaining valid pages are later
1221 * sent to the buddy page allocator.
1222 */
1223void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1224{
1225 unsigned long start_pfn = PFN_DOWN(start);
1226 unsigned long end_pfn = PFN_UP(end);
1227
1228 for (; start_pfn < end_pfn; start_pfn++) {
1229 if (pfn_valid(start_pfn)) {
1230 struct page *page = pfn_to_page(start_pfn);
1231
1232 init_reserved_page(start_pfn);
1233
1234 /* Avoid false-positive PageTail() */
1235 INIT_LIST_HEAD(&page->lru);
1236
1237 SetPageReserved(page);
1238 }
1239 }
1240}
1241
1242static void __free_pages_ok(struct page *page, unsigned int order)
1243{
1244 unsigned long flags;
1245 int migratetype;
1246 unsigned long pfn = page_to_pfn(page);
1247
1248 if (!free_pages_prepare(page, order, true))
1249 return;
1250
1251 migratetype = get_pfnblock_migratetype(page, pfn);
1252 local_irq_save(flags);
1253 __count_vm_events(PGFREE, 1 << order);
1254 free_one_page(page_zone(page), page, pfn, order, migratetype);
1255 local_irq_restore(flags);
1256}
1257
1258static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1259{
1260 unsigned int nr_pages = 1 << order;
1261 struct page *p = page;
1262 unsigned int loop;
1263
1264 prefetchw(p);
1265 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1266 prefetchw(p + 1);
1267 __ClearPageReserved(p);
1268 set_page_count(p, 0);
1269 }
1270 __ClearPageReserved(p);
1271 set_page_count(p, 0);
1272
1273 page_zone(page)->managed_pages += nr_pages;
1274 set_page_refcounted(page);
1275 __free_pages(page, order);
1276}
1277
1278#if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1279 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1280
1281static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1282
1283int __meminit early_pfn_to_nid(unsigned long pfn)
1284{
1285 static DEFINE_SPINLOCK(early_pfn_lock);
1286 int nid;
1287
1288 spin_lock(&early_pfn_lock);
1289 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1290 if (nid < 0)
1291 nid = first_online_node;
1292 spin_unlock(&early_pfn_lock);
1293
1294 return nid;
1295}
1296#endif
1297
1298#ifdef CONFIG_NODES_SPAN_OTHER_NODES
1299static inline bool __meminit __maybe_unused
1300meminit_pfn_in_nid(unsigned long pfn, int node,
1301 struct mminit_pfnnid_cache *state)
1302{
1303 int nid;
1304
1305 nid = __early_pfn_to_nid(pfn, state);
1306 if (nid >= 0 && nid != node)
1307 return false;
1308 return true;
1309}
1310
1311/* Only safe to use early in boot when initialisation is single-threaded */
1312static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1313{
1314 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1315}
1316
1317#else
1318
1319static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1320{
1321 return true;
1322}
1323static inline bool __meminit __maybe_unused
1324meminit_pfn_in_nid(unsigned long pfn, int node,
1325 struct mminit_pfnnid_cache *state)
1326{
1327 return true;
1328}
1329#endif
1330
1331
1332void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1333 unsigned int order)
1334{
1335 if (early_page_uninitialised(pfn))
1336 return;
1337 return __free_pages_boot_core(page, order);
1338}
1339
1340/*
1341 * Check that the whole (or subset of) a pageblock given by the interval of
1342 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1343 * with the migration of free compaction scanner. The scanners then need to
1344 * use only pfn_valid_within() check for arches that allow holes within
1345 * pageblocks.
1346 *
1347 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1348 *
1349 * It's possible on some configurations to have a setup like node0 node1 node0
1350 * i.e. it's possible that all pages within a zones range of pages do not
1351 * belong to a single zone. We assume that a border between node0 and node1
1352 * can occur within a single pageblock, but not a node0 node1 node0
1353 * interleaving within a single pageblock. It is therefore sufficient to check
1354 * the first and last page of a pageblock and avoid checking each individual
1355 * page in a pageblock.
1356 */
1357struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1358 unsigned long end_pfn, struct zone *zone)
1359{
1360 struct page *start_page;
1361 struct page *end_page;
1362
1363 /* end_pfn is one past the range we are checking */
1364 end_pfn--;
1365
1366 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1367 return NULL;
1368
1369 start_page = pfn_to_online_page(start_pfn);
1370 if (!start_page)
1371 return NULL;
1372
1373 if (page_zone(start_page) != zone)
1374 return NULL;
1375
1376 end_page = pfn_to_page(end_pfn);
1377
1378 /* This gives a shorter code than deriving page_zone(end_page) */
1379 if (page_zone_id(start_page) != page_zone_id(end_page))
1380 return NULL;
1381
1382 return start_page;
1383}
1384
1385void set_zone_contiguous(struct zone *zone)
1386{
1387 unsigned long block_start_pfn = zone->zone_start_pfn;
1388 unsigned long block_end_pfn;
1389
1390 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1391 for (; block_start_pfn < zone_end_pfn(zone);
1392 block_start_pfn = block_end_pfn,
1393 block_end_pfn += pageblock_nr_pages) {
1394
1395 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1396
1397 if (!__pageblock_pfn_to_page(block_start_pfn,
1398 block_end_pfn, zone))
1399 return;
1400 }
1401
1402 /* We confirm that there is no hole */
1403 zone->contiguous = true;
1404}
1405
1406void clear_zone_contiguous(struct zone *zone)
1407{
1408 zone->contiguous = false;
1409}
1410
1411#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1412static void __init deferred_free_range(unsigned long pfn,
1413 unsigned long nr_pages)
1414{
1415 struct page *page;
1416 unsigned long i;
1417
1418 if (!nr_pages)
1419 return;
1420
1421 page = pfn_to_page(pfn);
1422
1423 /* Free a large naturally-aligned chunk if possible */
1424 if (nr_pages == pageblock_nr_pages &&
1425 (pfn & (pageblock_nr_pages - 1)) == 0) {
1426 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1427 __free_pages_boot_core(page, pageblock_order);
1428 return;
1429 }
1430
1431 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1432 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1433 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1434 __free_pages_boot_core(page, 0);
1435 }
1436}
1437
1438/* Completion tracking for deferred_init_memmap() threads */
1439static atomic_t pgdat_init_n_undone __initdata;
1440static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1441
1442static inline void __init pgdat_init_report_one_done(void)
1443{
1444 if (atomic_dec_and_test(&pgdat_init_n_undone))
1445 complete(&pgdat_init_all_done_comp);
1446}
1447
1448/*
1449 * Returns true if page needs to be initialized or freed to buddy allocator.
1450 *
1451 * First we check if pfn is valid on architectures where it is possible to have
1452 * holes within pageblock_nr_pages. On systems where it is not possible, this
1453 * function is optimized out.
1454 *
1455 * Then, we check if a current large page is valid by only checking the validity
1456 * of the head pfn.
1457 *
1458 * Finally, meminit_pfn_in_nid is checked on systems where pfns can interleave
1459 * within a node: a pfn is between start and end of a node, but does not belong
1460 * to this memory node.
1461 */
1462static inline bool __init
1463deferred_pfn_valid(int nid, unsigned long pfn,
1464 struct mminit_pfnnid_cache *nid_init_state)
1465{
1466 if (!pfn_valid_within(pfn))
1467 return false;
1468 if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
1469 return false;
1470 if (!meminit_pfn_in_nid(pfn, nid, nid_init_state))
1471 return false;
1472 return true;
1473}
1474
1475/*
1476 * Free pages to buddy allocator. Try to free aligned pages in
1477 * pageblock_nr_pages sizes.
1478 */
1479static void __init deferred_free_pages(int nid, int zid, unsigned long pfn,
1480 unsigned long end_pfn)
1481{
1482 struct mminit_pfnnid_cache nid_init_state = { };
1483 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1484 unsigned long nr_free = 0;
1485
1486 for (; pfn < end_pfn; pfn++) {
1487 if (!deferred_pfn_valid(nid, pfn, &nid_init_state)) {
1488 deferred_free_range(pfn - nr_free, nr_free);
1489 nr_free = 0;
1490 } else if (!(pfn & nr_pgmask)) {
1491 deferred_free_range(pfn - nr_free, nr_free);
1492 nr_free = 1;
1493 touch_nmi_watchdog();
1494 } else {
1495 nr_free++;
1496 }
1497 }
1498 /* Free the last block of pages to allocator */
1499 deferred_free_range(pfn - nr_free, nr_free);
1500}
1501
1502/*
1503 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1504 * by performing it only once every pageblock_nr_pages.
1505 * Return number of pages initialized.
1506 */
1507static unsigned long __init deferred_init_pages(int nid, int zid,
1508 unsigned long pfn,
1509 unsigned long end_pfn)
1510{
1511 struct mminit_pfnnid_cache nid_init_state = { };
1512 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1513 unsigned long nr_pages = 0;
1514 struct page *page = NULL;
1515
1516 for (; pfn < end_pfn; pfn++) {
1517 if (!deferred_pfn_valid(nid, pfn, &nid_init_state)) {
1518 page = NULL;
1519 continue;
1520 } else if (!page || !(pfn & nr_pgmask)) {
1521 page = pfn_to_page(pfn);
1522 touch_nmi_watchdog();
1523 } else {
1524 page++;
1525 }
1526 __init_single_page(page, pfn, zid, nid);
1527 nr_pages++;
1528 }
1529 return (nr_pages);
1530}
1531
1532/* Initialise remaining memory on a node */
1533static int __init deferred_init_memmap(void *data)
1534{
1535 pg_data_t *pgdat = data;
1536 int nid = pgdat->node_id;
1537 unsigned long start = jiffies;
1538 unsigned long nr_pages = 0;
1539 unsigned long spfn, epfn, first_init_pfn, flags;
1540 phys_addr_t spa, epa;
1541 int zid;
1542 struct zone *zone;
1543 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1544 u64 i;
1545
1546 /* Bind memory initialisation thread to a local node if possible */
1547 if (!cpumask_empty(cpumask))
1548 set_cpus_allowed_ptr(current, cpumask);
1549
1550 pgdat_resize_lock(pgdat, &flags);
1551 first_init_pfn = pgdat->first_deferred_pfn;
1552 if (first_init_pfn == ULONG_MAX) {
1553 pgdat_resize_unlock(pgdat, &flags);
1554 pgdat_init_report_one_done();
1555 return 0;
1556 }
1557
1558 /* Sanity check boundaries */
1559 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1560 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1561 pgdat->first_deferred_pfn = ULONG_MAX;
1562
1563 /* Only the highest zone is deferred so find it */
1564 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1565 zone = pgdat->node_zones + zid;
1566 if (first_init_pfn < zone_end_pfn(zone))
1567 break;
1568 }
1569 first_init_pfn = max(zone->zone_start_pfn, first_init_pfn);
1570
1571 /*
1572 * Initialize and free pages. We do it in two loops: first we initialize
1573 * struct page, than free to buddy allocator, because while we are
1574 * freeing pages we can access pages that are ahead (computing buddy
1575 * page in __free_one_page()).
1576 */
1577 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1578 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1579 epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
1580 nr_pages += deferred_init_pages(nid, zid, spfn, epfn);
1581 }
1582 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1583 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1584 epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
1585 deferred_free_pages(nid, zid, spfn, epfn);
1586 }
1587 pgdat_resize_unlock(pgdat, &flags);
1588
1589 /* Sanity check that the next zone really is unpopulated */
1590 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1591
1592 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1593 jiffies_to_msecs(jiffies - start));
1594
1595 pgdat_init_report_one_done();
1596 return 0;
1597}
1598
1599/*
1600 * During boot we initialize deferred pages on-demand, as needed, but once
1601 * page_alloc_init_late() has finished, the deferred pages are all initialized,
1602 * and we can permanently disable that path.
1603 */
1604static DEFINE_STATIC_KEY_TRUE(deferred_pages);
1605
1606/*
1607 * If this zone has deferred pages, try to grow it by initializing enough
1608 * deferred pages to satisfy the allocation specified by order, rounded up to
1609 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1610 * of SECTION_SIZE bytes by initializing struct pages in increments of
1611 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1612 *
1613 * Return true when zone was grown, otherwise return false. We return true even
1614 * when we grow less than requested, to let the caller decide if there are
1615 * enough pages to satisfy the allocation.
1616 *
1617 * Note: We use noinline because this function is needed only during boot, and
1618 * it is called from a __ref function _deferred_grow_zone. This way we are
1619 * making sure that it is not inlined into permanent text section.
1620 */
1621static noinline bool __init
1622deferred_grow_zone(struct zone *zone, unsigned int order)
1623{
1624 int zid = zone_idx(zone);
1625 int nid = zone_to_nid(zone);
1626 pg_data_t *pgdat = NODE_DATA(nid);
1627 unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
1628 unsigned long nr_pages = 0;
1629 unsigned long first_init_pfn, spfn, epfn, t, flags;
1630 unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
1631 phys_addr_t spa, epa;
1632 u64 i;
1633
1634 /* Only the last zone may have deferred pages */
1635 if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))
1636 return false;
1637
1638 pgdat_resize_lock(pgdat, &flags);
1639
1640 /*
1641 * If deferred pages have been initialized while we were waiting for
1642 * the lock, return true, as the zone was grown. The caller will retry
1643 * this zone. We won't return to this function since the caller also
1644 * has this static branch.
1645 */
1646 if (!static_branch_unlikely(&deferred_pages)) {
1647 pgdat_resize_unlock(pgdat, &flags);
1648 return true;
1649 }
1650
1651 /*
1652 * If someone grew this zone while we were waiting for spinlock, return
1653 * true, as there might be enough pages already.
1654 */
1655 if (first_deferred_pfn != pgdat->first_deferred_pfn) {
1656 pgdat_resize_unlock(pgdat, &flags);
1657 return true;
1658 }
1659
1660 first_init_pfn = max(zone->zone_start_pfn, first_deferred_pfn);
1661
1662 if (first_init_pfn >= pgdat_end_pfn(pgdat)) {
1663 pgdat_resize_unlock(pgdat, &flags);
1664 return false;
1665 }
1666
1667 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1668 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1669 epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
1670
1671 while (spfn < epfn && nr_pages < nr_pages_needed) {
1672 t = ALIGN(spfn + PAGES_PER_SECTION, PAGES_PER_SECTION);
1673 first_deferred_pfn = min(t, epfn);
1674 nr_pages += deferred_init_pages(nid, zid, spfn,
1675 first_deferred_pfn);
1676 spfn = first_deferred_pfn;
1677 }
1678
1679 if (nr_pages >= nr_pages_needed)
1680 break;
1681 }
1682
1683 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1684 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1685 epfn = min_t(unsigned long, first_deferred_pfn, PFN_DOWN(epa));
1686 deferred_free_pages(nid, zid, spfn, epfn);
1687
1688 if (first_deferred_pfn == epfn)
1689 break;
1690 }
1691 pgdat->first_deferred_pfn = first_deferred_pfn;
1692 pgdat_resize_unlock(pgdat, &flags);
1693
1694 return nr_pages > 0;
1695}
1696
1697/*
1698 * deferred_grow_zone() is __init, but it is called from
1699 * get_page_from_freelist() during early boot until deferred_pages permanently
1700 * disables this call. This is why we have refdata wrapper to avoid warning,
1701 * and to ensure that the function body gets unloaded.
1702 */
1703static bool __ref
1704_deferred_grow_zone(struct zone *zone, unsigned int order)
1705{
1706 return deferred_grow_zone(zone, order);
1707}
1708
1709#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1710
1711void __init page_alloc_init_late(void)
1712{
1713 struct zone *zone;
1714
1715#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1716 int nid;
1717
1718 /* There will be num_node_state(N_MEMORY) threads */
1719 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1720 for_each_node_state(nid, N_MEMORY) {
1721 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1722 }
1723
1724 /* Block until all are initialised */
1725 wait_for_completion(&pgdat_init_all_done_comp);
1726
1727 /*
1728 * We initialized the rest of the deferred pages. Permanently disable
1729 * on-demand struct page initialization.
1730 */
1731 static_branch_disable(&deferred_pages);
1732
1733 /* Reinit limits that are based on free pages after the kernel is up */
1734 files_maxfiles_init();
1735#endif
1736#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
1737 /* Discard memblock private memory */
1738 memblock_discard();
1739#endif
1740
1741 for_each_populated_zone(zone)
1742 set_zone_contiguous(zone);
1743}
1744
1745#ifdef CONFIG_CMA
1746/* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1747void __init init_cma_reserved_pageblock(struct page *page)
1748{
1749 unsigned i = pageblock_nr_pages;
1750 struct page *p = page;
1751
1752 do {
1753 __ClearPageReserved(p);
1754 set_page_count(p, 0);
1755 } while (++p, --i);
1756
1757 set_pageblock_migratetype(page, MIGRATE_CMA);
1758
1759 if (pageblock_order >= MAX_ORDER) {
1760 i = pageblock_nr_pages;
1761 p = page;
1762 do {
1763 set_page_refcounted(p);
1764 __free_pages(p, MAX_ORDER - 1);
1765 p += MAX_ORDER_NR_PAGES;
1766 } while (i -= MAX_ORDER_NR_PAGES);
1767 } else {
1768 set_page_refcounted(page);
1769 __free_pages(page, pageblock_order);
1770 }
1771
1772 adjust_managed_page_count(page, pageblock_nr_pages);
1773}
1774#endif
1775
1776/*
1777 * The order of subdivision here is critical for the IO subsystem.
1778 * Please do not alter this order without good reasons and regression
1779 * testing. Specifically, as large blocks of memory are subdivided,
1780 * the order in which smaller blocks are delivered depends on the order
1781 * they're subdivided in this function. This is the primary factor
1782 * influencing the order in which pages are delivered to the IO
1783 * subsystem according to empirical testing, and this is also justified
1784 * by considering the behavior of a buddy system containing a single
1785 * large block of memory acted on by a series of small allocations.
1786 * This behavior is a critical factor in sglist merging's success.
1787 *
1788 * -- nyc
1789 */
1790static inline void expand(struct zone *zone, struct page *page,
1791 int low, int high, struct free_area *area,
1792 int migratetype)
1793{
1794 unsigned long size = 1 << high;
1795
1796 while (high > low) {
1797 area--;
1798 high--;
1799 size >>= 1;
1800 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1801
1802 /*
1803 * Mark as guard pages (or page), that will allow to
1804 * merge back to allocator when buddy will be freed.
1805 * Corresponding page table entries will not be touched,
1806 * pages will stay not present in virtual address space
1807 */
1808 if (set_page_guard(zone, &page[size], high, migratetype))
1809 continue;
1810
1811 list_add(&page[size].lru, &area->free_list[migratetype]);
1812 area->nr_free++;
1813 set_page_order(&page[size], high);
1814 }
1815}
1816
1817static void check_new_page_bad(struct page *page)
1818{
1819 const char *bad_reason = NULL;
1820 unsigned long bad_flags = 0;
1821
1822 if (unlikely(atomic_read(&page->_mapcount) != -1))
1823 bad_reason = "nonzero mapcount";
1824 if (unlikely(page->mapping != NULL))
1825 bad_reason = "non-NULL mapping";
1826 if (unlikely(page_ref_count(page) != 0))
1827 bad_reason = "nonzero _count";
1828 if (unlikely(page->flags & __PG_HWPOISON)) {
1829 bad_reason = "HWPoisoned (hardware-corrupted)";
1830 bad_flags = __PG_HWPOISON;
1831 /* Don't complain about hwpoisoned pages */
1832 page_mapcount_reset(page); /* remove PageBuddy */
1833 return;
1834 }
1835 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1836 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1837 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1838 }
1839#ifdef CONFIG_MEMCG
1840 if (unlikely(page->mem_cgroup))
1841 bad_reason = "page still charged to cgroup";
1842#endif
1843 bad_page(page, bad_reason, bad_flags);
1844}
1845
1846/*
1847 * This page is about to be returned from the page allocator
1848 */
1849static inline int check_new_page(struct page *page)
1850{
1851 if (likely(page_expected_state(page,
1852 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
1853 return 0;
1854
1855 check_new_page_bad(page);
1856 return 1;
1857}
1858
1859static inline bool free_pages_prezeroed(void)
1860{
1861 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1862 page_poisoning_enabled();
1863}
1864
1865#ifdef CONFIG_DEBUG_VM
1866static bool check_pcp_refill(struct page *page)
1867{
1868 return false;
1869}
1870
1871static bool check_new_pcp(struct page *page)
1872{
1873 return check_new_page(page);
1874}
1875#else
1876static bool check_pcp_refill(struct page *page)
1877{
1878 return check_new_page(page);
1879}
1880static bool check_new_pcp(struct page *page)
1881{
1882 return false;
1883}
1884#endif /* CONFIG_DEBUG_VM */
1885
1886static bool check_new_pages(struct page *page, unsigned int order)
1887{
1888 int i;
1889 for (i = 0; i < (1 << order); i++) {
1890 struct page *p = page + i;
1891
1892 if (unlikely(check_new_page(p)))
1893 return true;
1894 }
1895
1896 return false;
1897}
1898
1899inline void post_alloc_hook(struct page *page, unsigned int order,
1900 gfp_t gfp_flags)
1901{
1902 set_page_private(page, 0);
1903 set_page_refcounted(page);
1904
1905 arch_alloc_page(page, order);
1906 kernel_map_pages(page, 1 << order, 1);
1907 kernel_poison_pages(page, 1 << order, 1);
1908 kasan_alloc_pages(page, order);
1909 set_page_owner(page, order, gfp_flags);
1910}
1911
1912static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1913 unsigned int alloc_flags)
1914{
1915 int i;
1916
1917 post_alloc_hook(page, order, gfp_flags);
1918
1919 if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO))
1920 for (i = 0; i < (1 << order); i++)
1921 clear_highpage(page + i);
1922
1923 if (order && (gfp_flags & __GFP_COMP))
1924 prep_compound_page(page, order);
1925
1926 /*
1927 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1928 * allocate the page. The expectation is that the caller is taking
1929 * steps that will free more memory. The caller should avoid the page
1930 * being used for !PFMEMALLOC purposes.
1931 */
1932 if (alloc_flags & ALLOC_NO_WATERMARKS)
1933 set_page_pfmemalloc(page);
1934 else
1935 clear_page_pfmemalloc(page);
1936}
1937
1938/*
1939 * Go through the free lists for the given migratetype and remove
1940 * the smallest available page from the freelists
1941 */
1942static __always_inline
1943struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1944 int migratetype)
1945{
1946 unsigned int current_order;
1947 struct free_area *area;
1948 struct page *page;
1949
1950 /* Find a page of the appropriate size in the preferred list */
1951 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1952 area = &(zone->free_area[current_order]);
1953 page = list_first_entry_or_null(&area->free_list[migratetype],
1954 struct page, lru);
1955 if (!page)
1956 continue;
1957 list_del(&page->lru);
1958 rmv_page_order(page);
1959 area->nr_free--;
1960 expand(zone, page, order, current_order, area, migratetype);
1961 set_pcppage_migratetype(page, migratetype);
1962 return page;
1963 }
1964
1965 return NULL;
1966}
1967
1968
1969/*
1970 * This array describes the order lists are fallen back to when
1971 * the free lists for the desirable migrate type are depleted
1972 */
1973static int fallbacks[MIGRATE_TYPES][4] = {
1974 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1975 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1976 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1977#ifdef CONFIG_CMA
1978 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1979#endif
1980#ifdef CONFIG_MEMORY_ISOLATION
1981 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1982#endif
1983};
1984
1985#ifdef CONFIG_CMA
1986static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1987 unsigned int order)
1988{
1989 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1990}
1991#else
1992static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1993 unsigned int order) { return NULL; }
1994#endif
1995
1996/*
1997 * Move the free pages in a range to the free lists of the requested type.
1998 * Note that start_page and end_pages are not aligned on a pageblock
1999 * boundary. If alignment is required, use move_freepages_block()
2000 */
2001static int move_freepages(struct zone *zone,
2002 struct page *start_page, struct page *end_page,
2003 int migratetype, int *num_movable)
2004{
2005 struct page *page;
2006 unsigned int order;
2007 int pages_moved = 0;
2008
2009#ifndef CONFIG_HOLES_IN_ZONE
2010 /*
2011 * page_zone is not safe to call in this context when
2012 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
2013 * anyway as we check zone boundaries in move_freepages_block().
2014 * Remove at a later date when no bug reports exist related to
2015 * grouping pages by mobility
2016 */
2017 VM_BUG_ON(pfn_valid(page_to_pfn(start_page)) &&
2018 pfn_valid(page_to_pfn(end_page)) &&
2019 page_zone(start_page) != page_zone(end_page));
2020#endif
2021
2022 if (num_movable)
2023 *num_movable = 0;
2024
2025 for (page = start_page; page <= end_page;) {
2026 if (!pfn_valid_within(page_to_pfn(page))) {
2027 page++;
2028 continue;
2029 }
2030
2031 /* Make sure we are not inadvertently changing nodes */
2032 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
2033
2034 if (!PageBuddy(page)) {
2035 /*
2036 * We assume that pages that could be isolated for
2037 * migration are movable. But we don't actually try
2038 * isolating, as that would be expensive.
2039 */
2040 if (num_movable &&
2041 (PageLRU(page) || __PageMovable(page)))
2042 (*num_movable)++;
2043
2044 page++;
2045 continue;
2046 }
2047
2048 order = page_order(page);
2049 list_move(&page->lru,
2050 &zone->free_area[order].free_list[migratetype]);
2051 page += 1 << order;
2052 pages_moved += 1 << order;
2053 }
2054
2055 return pages_moved;
2056}
2057
2058int move_freepages_block(struct zone *zone, struct page *page,
2059 int migratetype, int *num_movable)
2060{
2061 unsigned long start_pfn, end_pfn;
2062 struct page *start_page, *end_page;
2063
2064 start_pfn = page_to_pfn(page);
2065 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
2066 start_page = pfn_to_page(start_pfn);
2067 end_page = start_page + pageblock_nr_pages - 1;
2068 end_pfn = start_pfn + pageblock_nr_pages - 1;
2069
2070 /* Do not cross zone boundaries */
2071 if (!zone_spans_pfn(zone, start_pfn))
2072 start_page = page;
2073 if (!zone_spans_pfn(zone, end_pfn))
2074 return 0;
2075
2076 return move_freepages(zone, start_page, end_page, migratetype,
2077 num_movable);
2078}
2079
2080static void change_pageblock_range(struct page *pageblock_page,
2081 int start_order, int migratetype)
2082{
2083 int nr_pageblocks = 1 << (start_order - pageblock_order);
2084
2085 while (nr_pageblocks--) {
2086 set_pageblock_migratetype(pageblock_page, migratetype);
2087 pageblock_page += pageblock_nr_pages;
2088 }
2089}
2090
2091/*
2092 * When we are falling back to another migratetype during allocation, try to
2093 * steal extra free pages from the same pageblocks to satisfy further
2094 * allocations, instead of polluting multiple pageblocks.
2095 *
2096 * If we are stealing a relatively large buddy page, it is likely there will
2097 * be more free pages in the pageblock, so try to steal them all. For
2098 * reclaimable and unmovable allocations, we steal regardless of page size,
2099 * as fragmentation caused by those allocations polluting movable pageblocks
2100 * is worse than movable allocations stealing from unmovable and reclaimable
2101 * pageblocks.
2102 */
2103static bool can_steal_fallback(unsigned int order, int start_mt)
2104{
2105 /*
2106 * Leaving this order check is intended, although there is
2107 * relaxed order check in next check. The reason is that
2108 * we can actually steal whole pageblock if this condition met,
2109 * but, below check doesn't guarantee it and that is just heuristic
2110 * so could be changed anytime.
2111 */
2112 if (order >= pageblock_order)
2113 return true;
2114
2115 if (order >= pageblock_order / 2 ||
2116 start_mt == MIGRATE_RECLAIMABLE ||
2117 start_mt == MIGRATE_UNMOVABLE ||
2118 page_group_by_mobility_disabled)
2119 return true;
2120
2121 return false;
2122}
2123
2124/*
2125 * This function implements actual steal behaviour. If order is large enough,
2126 * we can steal whole pageblock. If not, we first move freepages in this
2127 * pageblock to our migratetype and determine how many already-allocated pages
2128 * are there in the pageblock with a compatible migratetype. If at least half
2129 * of pages are free or compatible, we can change migratetype of the pageblock
2130 * itself, so pages freed in the future will be put on the correct free list.
2131 */
2132static void steal_suitable_fallback(struct zone *zone, struct page *page,
2133 int start_type, bool whole_block)
2134{
2135 unsigned int current_order = page_order(page);
2136 struct free_area *area;
2137 int free_pages, movable_pages, alike_pages;
2138 int old_block_type;
2139
2140 old_block_type = get_pageblock_migratetype(page);
2141
2142 /*
2143 * This can happen due to races and we want to prevent broken
2144 * highatomic accounting.
2145 */
2146 if (is_migrate_highatomic(old_block_type))
2147 goto single_page;
2148
2149 /* Take ownership for orders >= pageblock_order */
2150 if (current_order >= pageblock_order) {
2151 change_pageblock_range(page, current_order, start_type);
2152 goto single_page;
2153 }
2154
2155 /* We are not allowed to try stealing from the whole block */
2156 if (!whole_block)
2157 goto single_page;
2158
2159 free_pages = move_freepages_block(zone, page, start_type,
2160 &movable_pages);
2161 /*
2162 * Determine how many pages are compatible with our allocation.
2163 * For movable allocation, it's the number of movable pages which
2164 * we just obtained. For other types it's a bit more tricky.
2165 */
2166 if (start_type == MIGRATE_MOVABLE) {
2167 alike_pages = movable_pages;
2168 } else {
2169 /*
2170 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2171 * to MOVABLE pageblock, consider all non-movable pages as
2172 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2173 * vice versa, be conservative since we can't distinguish the
2174 * exact migratetype of non-movable pages.
2175 */
2176 if (old_block_type == MIGRATE_MOVABLE)
2177 alike_pages = pageblock_nr_pages
2178 - (free_pages + movable_pages);
2179 else
2180 alike_pages = 0;
2181 }
2182
2183 /* moving whole block can fail due to zone boundary conditions */
2184 if (!free_pages)
2185 goto single_page;
2186
2187 /*
2188 * If a sufficient number of pages in the block are either free or of
2189 * comparable migratability as our allocation, claim the whole block.
2190 */
2191 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2192 page_group_by_mobility_disabled)
2193 set_pageblock_migratetype(page, start_type);
2194
2195 return;
2196
2197single_page:
2198 area = &zone->free_area[current_order];
2199 list_move(&page->lru, &area->free_list[start_type]);
2200}
2201
2202/*
2203 * Check whether there is a suitable fallback freepage with requested order.
2204 * If only_stealable is true, this function returns fallback_mt only if
2205 * we can steal other freepages all together. This would help to reduce
2206 * fragmentation due to mixed migratetype pages in one pageblock.
2207 */
2208int find_suitable_fallback(struct free_area *area, unsigned int order,
2209 int migratetype, bool only_stealable, bool *can_steal)
2210{
2211 int i;
2212 int fallback_mt;
2213
2214 if (area->nr_free == 0)
2215 return -1;
2216
2217 *can_steal = false;
2218 for (i = 0;; i++) {
2219 fallback_mt = fallbacks[migratetype][i];
2220 if (fallback_mt == MIGRATE_TYPES)
2221 break;
2222
2223 if (list_empty(&area->free_list[fallback_mt]))
2224 continue;
2225
2226 if (can_steal_fallback(order, migratetype))
2227 *can_steal = true;
2228
2229 if (!only_stealable)
2230 return fallback_mt;
2231
2232 if (*can_steal)
2233 return fallback_mt;
2234 }
2235
2236 return -1;
2237}
2238
2239/*
2240 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2241 * there are no empty page blocks that contain a page with a suitable order
2242 */
2243static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2244 unsigned int alloc_order)
2245{
2246 int mt;
2247 unsigned long max_managed, flags;
2248
2249 /*
2250 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2251 * Check is race-prone but harmless.
2252 */
2253 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2254 if (zone->nr_reserved_highatomic >= max_managed)
2255 return;
2256
2257 spin_lock_irqsave(&zone->lock, flags);
2258
2259 /* Recheck the nr_reserved_highatomic limit under the lock */
2260 if (zone->nr_reserved_highatomic >= max_managed)
2261 goto out_unlock;
2262
2263 /* Yoink! */
2264 mt = get_pageblock_migratetype(page);
2265 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2266 && !is_migrate_cma(mt)) {
2267 zone->nr_reserved_highatomic += pageblock_nr_pages;
2268 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2269 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2270 }
2271
2272out_unlock:
2273 spin_unlock_irqrestore(&zone->lock, flags);
2274}
2275
2276/*
2277 * Used when an allocation is about to fail under memory pressure. This
2278 * potentially hurts the reliability of high-order allocations when under
2279 * intense memory pressure but failed atomic allocations should be easier
2280 * to recover from than an OOM.
2281 *
2282 * If @force is true, try to unreserve a pageblock even though highatomic
2283 * pageblock is exhausted.
2284 */
2285static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2286 bool force)
2287{
2288 struct zonelist *zonelist = ac->zonelist;
2289 unsigned long flags;
2290 struct zoneref *z;
2291 struct zone *zone;
2292 struct page *page;
2293 int order;
2294 bool ret;
2295
2296 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2297 ac->nodemask) {
2298 /*
2299 * Preserve at least one pageblock unless memory pressure
2300 * is really high.
2301 */
2302 if (!force && zone->nr_reserved_highatomic <=
2303 pageblock_nr_pages)
2304 continue;
2305
2306 spin_lock_irqsave(&zone->lock, flags);
2307 for (order = 0; order < MAX_ORDER; order++) {
2308 struct free_area *area = &(zone->free_area[order]);
2309
2310 page = list_first_entry_or_null(
2311 &area->free_list[MIGRATE_HIGHATOMIC],
2312 struct page, lru);
2313 if (!page)
2314 continue;
2315
2316 /*
2317 * In page freeing path, migratetype change is racy so
2318 * we can counter several free pages in a pageblock
2319 * in this loop althoug we changed the pageblock type
2320 * from highatomic to ac->migratetype. So we should
2321 * adjust the count once.
2322 */
2323 if (is_migrate_highatomic_page(page)) {
2324 /*
2325 * It should never happen but changes to
2326 * locking could inadvertently allow a per-cpu
2327 * drain to add pages to MIGRATE_HIGHATOMIC
2328 * while unreserving so be safe and watch for
2329 * underflows.
2330 */
2331 zone->nr_reserved_highatomic -= min(
2332 pageblock_nr_pages,
2333 zone->nr_reserved_highatomic);
2334 }
2335
2336 /*
2337 * Convert to ac->migratetype and avoid the normal
2338 * pageblock stealing heuristics. Minimally, the caller
2339 * is doing the work and needs the pages. More
2340 * importantly, if the block was always converted to
2341 * MIGRATE_UNMOVABLE or another type then the number
2342 * of pageblocks that cannot be completely freed
2343 * may increase.
2344 */
2345 set_pageblock_migratetype(page, ac->migratetype);
2346 ret = move_freepages_block(zone, page, ac->migratetype,
2347 NULL);
2348 if (ret) {
2349 spin_unlock_irqrestore(&zone->lock, flags);
2350 return ret;
2351 }
2352 }
2353 spin_unlock_irqrestore(&zone->lock, flags);
2354 }
2355
2356 return false;
2357}
2358
2359/*
2360 * Try finding a free buddy page on the fallback list and put it on the free
2361 * list of requested migratetype, possibly along with other pages from the same
2362 * block, depending on fragmentation avoidance heuristics. Returns true if
2363 * fallback was found so that __rmqueue_smallest() can grab it.
2364 *
2365 * The use of signed ints for order and current_order is a deliberate
2366 * deviation from the rest of this file, to make the for loop
2367 * condition simpler.
2368 */
2369static __always_inline bool
2370__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
2371{
2372 struct free_area *area;
2373 int current_order;
2374 struct page *page;
2375 int fallback_mt;
2376 bool can_steal;
2377
2378 /*
2379 * Find the largest available free page in the other list. This roughly
2380 * approximates finding the pageblock with the most free pages, which
2381 * would be too costly to do exactly.
2382 */
2383 for (current_order = MAX_ORDER - 1; current_order >= order;
2384 --current_order) {
2385 area = &(zone->free_area[current_order]);
2386 fallback_mt = find_suitable_fallback(area, current_order,
2387 start_migratetype, false, &can_steal);
2388 if (fallback_mt == -1)
2389 continue;
2390
2391 /*
2392 * We cannot steal all free pages from the pageblock and the
2393 * requested migratetype is movable. In that case it's better to
2394 * steal and split the smallest available page instead of the
2395 * largest available page, because even if the next movable
2396 * allocation falls back into a different pageblock than this
2397 * one, it won't cause permanent fragmentation.
2398 */
2399 if (!can_steal && start_migratetype == MIGRATE_MOVABLE
2400 && current_order > order)
2401 goto find_smallest;
2402
2403 goto do_steal;
2404 }
2405
2406 return false;
2407
2408find_smallest:
2409 for (current_order = order; current_order < MAX_ORDER;
2410 current_order++) {
2411 area = &(zone->free_area[current_order]);
2412 fallback_mt = find_suitable_fallback(area, current_order,
2413 start_migratetype, false, &can_steal);
2414 if (fallback_mt != -1)
2415 break;
2416 }
2417
2418 /*
2419 * This should not happen - we already found a suitable fallback
2420 * when looking for the largest page.
2421 */
2422 VM_BUG_ON(current_order == MAX_ORDER);
2423
2424do_steal:
2425 page = list_first_entry(&area->free_list[fallback_mt],
2426 struct page, lru);
2427
2428 steal_suitable_fallback(zone, page, start_migratetype, can_steal);
2429
2430 trace_mm_page_alloc_extfrag(page, order, current_order,
2431 start_migratetype, fallback_mt);
2432
2433 return true;
2434
2435}
2436
2437/*
2438 * Do the hard work of removing an element from the buddy allocator.
2439 * Call me with the zone->lock already held.
2440 */
2441static __always_inline struct page *
2442__rmqueue(struct zone *zone, unsigned int order, int migratetype)
2443{
2444 struct page *page;
2445
2446retry:
2447 page = __rmqueue_smallest(zone, order, migratetype);
2448 if (unlikely(!page)) {
2449 if (migratetype == MIGRATE_MOVABLE)
2450 page = __rmqueue_cma_fallback(zone, order);
2451
2452 if (!page && __rmqueue_fallback(zone, order, migratetype))
2453 goto retry;
2454 }
2455
2456 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2457 return page;
2458}
2459
2460/*
2461 * Obtain a specified number of elements from the buddy allocator, all under
2462 * a single hold of the lock, for efficiency. Add them to the supplied list.
2463 * Returns the number of new pages which were placed at *list.
2464 */
2465static int rmqueue_bulk(struct zone *zone, unsigned int order,
2466 unsigned long count, struct list_head *list,
2467 int migratetype)
2468{
2469 int i, alloced = 0;
2470
2471 spin_lock(&zone->lock);
2472 for (i = 0; i < count; ++i) {
2473 struct page *page = __rmqueue(zone, order, migratetype);
2474 if (unlikely(page == NULL))
2475 break;
2476
2477 if (unlikely(check_pcp_refill(page)))
2478 continue;
2479
2480 /*
2481 * Split buddy pages returned by expand() are received here in
2482 * physical page order. The page is added to the tail of
2483 * caller's list. From the callers perspective, the linked list
2484 * is ordered by page number under some conditions. This is
2485 * useful for IO devices that can forward direction from the
2486 * head, thus also in the physical page order. This is useful
2487 * for IO devices that can merge IO requests if the physical
2488 * pages are ordered properly.
2489 */
2490 list_add_tail(&page->lru, list);
2491 alloced++;
2492 if (is_migrate_cma(get_pcppage_migratetype(page)))
2493 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2494 -(1 << order));
2495 }
2496
2497 /*
2498 * i pages were removed from the buddy list even if some leak due
2499 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2500 * on i. Do not confuse with 'alloced' which is the number of
2501 * pages added to the pcp list.
2502 */
2503 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2504 spin_unlock(&zone->lock);
2505 return alloced;
2506}
2507
2508#ifdef CONFIG_NUMA
2509/*
2510 * Called from the vmstat counter updater to drain pagesets of this
2511 * currently executing processor on remote nodes after they have
2512 * expired.
2513 *
2514 * Note that this function must be called with the thread pinned to
2515 * a single processor.
2516 */
2517void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2518{
2519 unsigned long flags;
2520 int to_drain, batch;
2521
2522 local_irq_save(flags);
2523 batch = READ_ONCE(pcp->batch);
2524 to_drain = min(pcp->count, batch);
2525 if (to_drain > 0)
2526 free_pcppages_bulk(zone, to_drain, pcp);
2527 local_irq_restore(flags);
2528}
2529#endif
2530
2531/*
2532 * Drain pcplists of the indicated processor and zone.
2533 *
2534 * The processor must either be the current processor and the
2535 * thread pinned to the current processor or a processor that
2536 * is not online.
2537 */
2538static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2539{
2540 unsigned long flags;
2541 struct per_cpu_pageset *pset;
2542 struct per_cpu_pages *pcp;
2543
2544 local_irq_save(flags);
2545 pset = per_cpu_ptr(zone->pageset, cpu);
2546
2547 pcp = &pset->pcp;
2548 if (pcp->count)
2549 free_pcppages_bulk(zone, pcp->count, pcp);
2550 local_irq_restore(flags);
2551}
2552
2553/*
2554 * Drain pcplists of all zones on the indicated processor.
2555 *
2556 * The processor must either be the current processor and the
2557 * thread pinned to the current processor or a processor that
2558 * is not online.
2559 */
2560static void drain_pages(unsigned int cpu)
2561{
2562 struct zone *zone;
2563
2564 for_each_populated_zone(zone) {
2565 drain_pages_zone(cpu, zone);
2566 }
2567}
2568
2569/*
2570 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2571 *
2572 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2573 * the single zone's pages.
2574 */
2575void drain_local_pages(struct zone *zone)
2576{
2577 int cpu = smp_processor_id();
2578
2579 if (zone)
2580 drain_pages_zone(cpu, zone);
2581 else
2582 drain_pages(cpu);
2583}
2584
2585static void drain_local_pages_wq(struct work_struct *work)
2586{
2587 /*
2588 * drain_all_pages doesn't use proper cpu hotplug protection so
2589 * we can race with cpu offline when the WQ can move this from
2590 * a cpu pinned worker to an unbound one. We can operate on a different
2591 * cpu which is allright but we also have to make sure to not move to
2592 * a different one.
2593 */
2594 preempt_disable();
2595 drain_local_pages(NULL);
2596 preempt_enable();
2597}
2598
2599/*
2600 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2601 *
2602 * When zone parameter is non-NULL, spill just the single zone's pages.
2603 *
2604 * Note that this can be extremely slow as the draining happens in a workqueue.
2605 */
2606void drain_all_pages(struct zone *zone)
2607{
2608 int cpu;
2609
2610 /*
2611 * Allocate in the BSS so we wont require allocation in
2612 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2613 */
2614 static cpumask_t cpus_with_pcps;
2615
2616 /*
2617 * Make sure nobody triggers this path before mm_percpu_wq is fully
2618 * initialized.
2619 */
2620 if (WARN_ON_ONCE(!mm_percpu_wq))
2621 return;
2622
2623 /*
2624 * Do not drain if one is already in progress unless it's specific to
2625 * a zone. Such callers are primarily CMA and memory hotplug and need
2626 * the drain to be complete when the call returns.
2627 */
2628 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
2629 if (!zone)
2630 return;
2631 mutex_lock(&pcpu_drain_mutex);
2632 }
2633
2634 /*
2635 * We don't care about racing with CPU hotplug event
2636 * as offline notification will cause the notified
2637 * cpu to drain that CPU pcps and on_each_cpu_mask
2638 * disables preemption as part of its processing
2639 */
2640 for_each_online_cpu(cpu) {
2641 struct per_cpu_pageset *pcp;
2642 struct zone *z;
2643 bool has_pcps = false;
2644
2645 if (zone) {
2646 pcp = per_cpu_ptr(zone->pageset, cpu);
2647 if (pcp->pcp.count)
2648 has_pcps = true;
2649 } else {
2650 for_each_populated_zone(z) {
2651 pcp = per_cpu_ptr(z->pageset, cpu);
2652 if (pcp->pcp.count) {
2653 has_pcps = true;
2654 break;
2655 }
2656 }
2657 }
2658
2659 if (has_pcps)
2660 cpumask_set_cpu(cpu, &cpus_with_pcps);
2661 else
2662 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2663 }
2664
2665 for_each_cpu(cpu, &cpus_with_pcps) {
2666 struct work_struct *work = per_cpu_ptr(&pcpu_drain, cpu);
2667 INIT_WORK(work, drain_local_pages_wq);
2668 queue_work_on(cpu, mm_percpu_wq, work);
2669 }
2670 for_each_cpu(cpu, &cpus_with_pcps)
2671 flush_work(per_cpu_ptr(&pcpu_drain, cpu));
2672
2673 mutex_unlock(&pcpu_drain_mutex);
2674}
2675
2676#ifdef CONFIG_HIBERNATION
2677
2678/*
2679 * Touch the watchdog for every WD_PAGE_COUNT pages.
2680 */
2681#define WD_PAGE_COUNT (128*1024)
2682
2683void mark_free_pages(struct zone *zone)
2684{
2685 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
2686 unsigned long flags;
2687 unsigned int order, t;
2688 struct page *page;
2689
2690 if (zone_is_empty(zone))
2691 return;
2692
2693 spin_lock_irqsave(&zone->lock, flags);
2694
2695 max_zone_pfn = zone_end_pfn(zone);
2696 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2697 if (pfn_valid(pfn)) {
2698 page = pfn_to_page(pfn);
2699
2700 if (!--page_count) {
2701 touch_nmi_watchdog();
2702 page_count = WD_PAGE_COUNT;
2703 }
2704
2705 if (page_zone(page) != zone)
2706 continue;
2707
2708 if (!swsusp_page_is_forbidden(page))
2709 swsusp_unset_page_free(page);
2710 }
2711
2712 for_each_migratetype_order(order, t) {
2713 list_for_each_entry(page,
2714 &zone->free_area[order].free_list[t], lru) {
2715 unsigned long i;
2716
2717 pfn = page_to_pfn(page);
2718 for (i = 0; i < (1UL << order); i++) {
2719 if (!--page_count) {
2720 touch_nmi_watchdog();
2721 page_count = WD_PAGE_COUNT;
2722 }
2723 swsusp_set_page_free(pfn_to_page(pfn + i));
2724 }
2725 }
2726 }
2727 spin_unlock_irqrestore(&zone->lock, flags);
2728}
2729#endif /* CONFIG_PM */
2730
2731static bool free_unref_page_prepare(struct page *page, unsigned long pfn)
2732{
2733 int migratetype;
2734
2735 if (!free_pcp_prepare(page))
2736 return false;
2737
2738 migratetype = get_pfnblock_migratetype(page, pfn);
2739 set_pcppage_migratetype(page, migratetype);
2740 return true;
2741}
2742
2743static void free_unref_page_commit(struct page *page, unsigned long pfn)
2744{
2745 struct zone *zone = page_zone(page);
2746 struct per_cpu_pages *pcp;
2747 int migratetype;
2748
2749 migratetype = get_pcppage_migratetype(page);
2750 __count_vm_event(PGFREE);
2751
2752 /*
2753 * We only track unmovable, reclaimable and movable on pcp lists.
2754 * Free ISOLATE pages back to the allocator because they are being
2755 * offlined but treat HIGHATOMIC as movable pages so we can get those
2756 * areas back if necessary. Otherwise, we may have to free
2757 * excessively into the page allocator
2758 */
2759 if (migratetype >= MIGRATE_PCPTYPES) {
2760 if (unlikely(is_migrate_isolate(migratetype))) {
2761 free_one_page(zone, page, pfn, 0, migratetype);
2762 return;
2763 }
2764 migratetype = MIGRATE_MOVABLE;
2765 }
2766
2767 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2768 list_add(&page->lru, &pcp->lists[migratetype]);
2769 pcp->count++;
2770 if (pcp->count >= pcp->high) {
2771 unsigned long batch = READ_ONCE(pcp->batch);
2772 free_pcppages_bulk(zone, batch, pcp);
2773 }
2774}
2775
2776/*
2777 * Free a 0-order page
2778 */
2779void free_unref_page(struct page *page)
2780{
2781 unsigned long flags;
2782 unsigned long pfn = page_to_pfn(page);
2783
2784 if (!free_unref_page_prepare(page, pfn))
2785 return;
2786
2787 local_irq_save(flags);
2788 free_unref_page_commit(page, pfn);
2789 local_irq_restore(flags);
2790}
2791
2792/*
2793 * Free a list of 0-order pages
2794 */
2795void free_unref_page_list(struct list_head *list)
2796{
2797 struct page *page, *next;
2798 unsigned long flags, pfn;
2799 int batch_count = 0;
2800
2801 /* Prepare pages for freeing */
2802 list_for_each_entry_safe(page, next, list, lru) {
2803 pfn = page_to_pfn(page);
2804 if (!free_unref_page_prepare(page, pfn))
2805 list_del(&page->lru);
2806 set_page_private(page, pfn);
2807 }
2808
2809 local_irq_save(flags);
2810 list_for_each_entry_safe(page, next, list, lru) {
2811 unsigned long pfn = page_private(page);
2812
2813 set_page_private(page, 0);
2814 trace_mm_page_free_batched(page);
2815 free_unref_page_commit(page, pfn);
2816
2817 /*
2818 * Guard against excessive IRQ disabled times when we get
2819 * a large list of pages to free.
2820 */
2821 if (++batch_count == SWAP_CLUSTER_MAX) {
2822 local_irq_restore(flags);
2823 batch_count = 0;
2824 local_irq_save(flags);
2825 }
2826 }
2827 local_irq_restore(flags);
2828}
2829
2830/*
2831 * split_page takes a non-compound higher-order page, and splits it into
2832 * n (1<<order) sub-pages: page[0..n]
2833 * Each sub-page must be freed individually.
2834 *
2835 * Note: this is probably too low level an operation for use in drivers.
2836 * Please consult with lkml before using this in your driver.
2837 */
2838void split_page(struct page *page, unsigned int order)
2839{
2840 int i;
2841
2842 VM_BUG_ON_PAGE(PageCompound(page), page);
2843 VM_BUG_ON_PAGE(!page_count(page), page);
2844
2845 for (i = 1; i < (1 << order); i++)
2846 set_page_refcounted(page + i);
2847 split_page_owner(page, order);
2848}
2849EXPORT_SYMBOL_GPL(split_page);
2850
2851int __isolate_free_page(struct page *page, unsigned int order)
2852{
2853 unsigned long watermark;
2854 struct zone *zone;
2855 int mt;
2856
2857 BUG_ON(!PageBuddy(page));
2858
2859 zone = page_zone(page);
2860 mt = get_pageblock_migratetype(page);
2861
2862 if (!is_migrate_isolate(mt)) {
2863 /*
2864 * Obey watermarks as if the page was being allocated. We can
2865 * emulate a high-order watermark check with a raised order-0
2866 * watermark, because we already know our high-order page
2867 * exists.
2868 */
2869 watermark = min_wmark_pages(zone) + (1UL << order);
2870 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
2871 return 0;
2872
2873 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2874 }
2875
2876 /* Remove page from free list */
2877 list_del(&page->lru);
2878 zone->free_area[order].nr_free--;
2879 rmv_page_order(page);
2880
2881 /*
2882 * Set the pageblock if the isolated page is at least half of a
2883 * pageblock
2884 */
2885 if (order >= pageblock_order - 1) {
2886 struct page *endpage = page + (1 << order) - 1;
2887 for (; page < endpage; page += pageblock_nr_pages) {
2888 int mt = get_pageblock_migratetype(page);
2889 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
2890 && !is_migrate_highatomic(mt))
2891 set_pageblock_migratetype(page,
2892 MIGRATE_MOVABLE);
2893 }
2894 }
2895
2896
2897 return 1UL << order;
2898}
2899
2900/*
2901 * Update NUMA hit/miss statistics
2902 *
2903 * Must be called with interrupts disabled.
2904 */
2905static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
2906{
2907#ifdef CONFIG_NUMA
2908 enum numa_stat_item local_stat = NUMA_LOCAL;
2909
2910 /* skip numa counters update if numa stats is disabled */
2911 if (!static_branch_likely(&vm_numa_stat_key))
2912 return;
2913
2914 if (z->node != numa_node_id())
2915 local_stat = NUMA_OTHER;
2916
2917 if (z->node == preferred_zone->node)
2918 __inc_numa_state(z, NUMA_HIT);
2919 else {
2920 __inc_numa_state(z, NUMA_MISS);
2921 __inc_numa_state(preferred_zone, NUMA_FOREIGN);
2922 }
2923 __inc_numa_state(z, local_stat);
2924#endif
2925}
2926
2927/* Remove page from the per-cpu list, caller must protect the list */
2928static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
2929 struct per_cpu_pages *pcp,
2930 struct list_head *list)
2931{
2932 struct page *page;
2933
2934 do {
2935 if (list_empty(list)) {
2936 pcp->count += rmqueue_bulk(zone, 0,
2937 pcp->batch, list,
2938 migratetype);
2939 if (unlikely(list_empty(list)))
2940 return NULL;
2941 }
2942
2943 page = list_first_entry(list, struct page, lru);
2944 list_del(&page->lru);
2945 pcp->count--;
2946 } while (check_new_pcp(page));
2947
2948 return page;
2949}
2950
2951/* Lock and remove page from the per-cpu list */
2952static struct page *rmqueue_pcplist(struct zone *preferred_zone,
2953 struct zone *zone, unsigned int order,
2954 gfp_t gfp_flags, int migratetype)
2955{
2956 struct per_cpu_pages *pcp;
2957 struct list_head *list;
2958 struct page *page;
2959 unsigned long flags;
2960
2961 local_irq_save(flags);
2962 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2963 list = &pcp->lists[migratetype];
2964 page = __rmqueue_pcplist(zone, migratetype, pcp, list);
2965 if (page) {
2966 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
2967 zone_statistics(preferred_zone, zone);
2968 }
2969 local_irq_restore(flags);
2970 return page;
2971}
2972
2973/*
2974 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2975 */
2976static inline
2977struct page *rmqueue(struct zone *preferred_zone,
2978 struct zone *zone, unsigned int order,
2979 gfp_t gfp_flags, unsigned int alloc_flags,
2980 int migratetype)
2981{
2982 unsigned long flags;
2983 struct page *page;
2984
2985 if (likely(order == 0)) {
2986 page = rmqueue_pcplist(preferred_zone, zone, order,
2987 gfp_flags, migratetype);
2988 goto out;
2989 }
2990
2991 /*
2992 * We most definitely don't want callers attempting to
2993 * allocate greater than order-1 page units with __GFP_NOFAIL.
2994 */
2995 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2996 spin_lock_irqsave(&zone->lock, flags);
2997
2998 do {
2999 page = NULL;
3000 if (alloc_flags & ALLOC_HARDER) {
3001 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
3002 if (page)
3003 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3004 }
3005 if (!page)
3006 page = __rmqueue(zone, order, migratetype);
3007 } while (page && check_new_pages(page, order));
3008 spin_unlock(&zone->lock);
3009 if (!page)
3010 goto failed;
3011 __mod_zone_freepage_state(zone, -(1 << order),
3012 get_pcppage_migratetype(page));
3013
3014 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
3015 zone_statistics(preferred_zone, zone);
3016 local_irq_restore(flags);
3017
3018out:
3019 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
3020 return page;
3021
3022failed:
3023 local_irq_restore(flags);
3024 return NULL;
3025}
3026
3027#ifdef CONFIG_FAIL_PAGE_ALLOC
3028
3029static struct {
3030 struct fault_attr attr;
3031
3032 bool ignore_gfp_highmem;
3033 bool ignore_gfp_reclaim;
3034 u32 min_order;
3035} fail_page_alloc = {
3036 .attr = FAULT_ATTR_INITIALIZER,
3037 .ignore_gfp_reclaim = true,
3038 .ignore_gfp_highmem = true,
3039 .min_order = 1,
3040};
3041
3042static int __init setup_fail_page_alloc(char *str)
3043{
3044 return setup_fault_attr(&fail_page_alloc.attr, str);
3045}
3046__setup("fail_page_alloc=", setup_fail_page_alloc);
3047
3048static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3049{
3050 if (order < fail_page_alloc.min_order)
3051 return false;
3052 if (gfp_mask & __GFP_NOFAIL)
3053 return false;
3054 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
3055 return false;
3056 if (fail_page_alloc.ignore_gfp_reclaim &&
3057 (gfp_mask & __GFP_DIRECT_RECLAIM))
3058 return false;
3059
3060 return should_fail(&fail_page_alloc.attr, 1 << order);
3061}
3062
3063#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3064
3065static int __init fail_page_alloc_debugfs(void)
3066{
3067 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
3068 struct dentry *dir;
3069
3070 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
3071 &fail_page_alloc.attr);
3072 if (IS_ERR(dir))
3073 return PTR_ERR(dir);
3074
3075 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
3076 &fail_page_alloc.ignore_gfp_reclaim))
3077 goto fail;
3078 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
3079 &fail_page_alloc.ignore_gfp_highmem))
3080 goto fail;
3081 if (!debugfs_create_u32("min-order", mode, dir,
3082 &fail_page_alloc.min_order))
3083 goto fail;
3084
3085 return 0;
3086fail:
3087 debugfs_remove_recursive(dir);
3088
3089 return -ENOMEM;
3090}
3091
3092late_initcall(fail_page_alloc_debugfs);
3093
3094#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3095
3096#else /* CONFIG_FAIL_PAGE_ALLOC */
3097
3098static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3099{
3100 return false;
3101}
3102
3103#endif /* CONFIG_FAIL_PAGE_ALLOC */
3104
3105/*
3106 * Return true if free base pages are above 'mark'. For high-order checks it
3107 * will return true of the order-0 watermark is reached and there is at least
3108 * one free page of a suitable size. Checking now avoids taking the zone lock
3109 * to check in the allocation paths if no pages are free.
3110 */
3111bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3112 int classzone_idx, unsigned int alloc_flags,
3113 long free_pages)
3114{
3115 long min = mark;
3116 int o;
3117 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3118
3119 /* free_pages may go negative - that's OK */
3120 free_pages -= (1 << order) - 1;
3121
3122 if (alloc_flags & ALLOC_HIGH)
3123 min -= min / 2;
3124
3125 /*
3126 * If the caller does not have rights to ALLOC_HARDER then subtract
3127 * the high-atomic reserves. This will over-estimate the size of the
3128 * atomic reserve but it avoids a search.
3129 */
3130 if (likely(!alloc_harder)) {
3131 free_pages -= z->nr_reserved_highatomic;
3132 } else {
3133 /*
3134 * OOM victims can try even harder than normal ALLOC_HARDER
3135 * users on the grounds that it's definitely going to be in
3136 * the exit path shortly and free memory. Any allocation it
3137 * makes during the free path will be small and short-lived.
3138 */
3139 if (alloc_flags & ALLOC_OOM)
3140 min -= min / 2;
3141 else
3142 min -= min / 4;
3143 }
3144
3145
3146#ifdef CONFIG_CMA
3147 /* If allocation can't use CMA areas don't use free CMA pages */
3148 if (!(alloc_flags & ALLOC_CMA))
3149 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
3150#endif
3151
3152 /*
3153 * Check watermarks for an order-0 allocation request. If these
3154 * are not met, then a high-order request also cannot go ahead
3155 * even if a suitable page happened to be free.
3156 */
3157 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
3158 return false;
3159
3160 /* If this is an order-0 request then the watermark is fine */
3161 if (!order)
3162 return true;
3163
3164 /* For a high-order request, check at least one suitable page is free */
3165 for (o = order; o < MAX_ORDER; o++) {
3166 struct free_area *area = &z->free_area[o];
3167 int mt;
3168
3169 if (!area->nr_free)
3170 continue;
3171
3172 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
3173 if (!list_empty(&area->free_list[mt]))
3174 return true;
3175 }
3176
3177#ifdef CONFIG_CMA
3178 if ((alloc_flags & ALLOC_CMA) &&
3179 !list_empty(&area->free_list[MIGRATE_CMA])) {
3180 return true;
3181 }
3182#endif
3183 if (alloc_harder &&
3184 !list_empty(&area->free_list[MIGRATE_HIGHATOMIC]))
3185 return true;
3186 }
3187 return false;
3188}
3189
3190bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3191 int classzone_idx, unsigned int alloc_flags)
3192{
3193 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
3194 zone_page_state(z, NR_FREE_PAGES));
3195}
3196
3197static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
3198 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
3199{
3200 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3201 long cma_pages = 0;
3202
3203#ifdef CONFIG_CMA
3204 /* If allocation can't use CMA areas don't use free CMA pages */
3205 if (!(alloc_flags & ALLOC_CMA))
3206 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
3207#endif
3208
3209 /*
3210 * Fast check for order-0 only. If this fails then the reserves
3211 * need to be calculated. There is a corner case where the check
3212 * passes but only the high-order atomic reserve are free. If
3213 * the caller is !atomic then it'll uselessly search the free
3214 * list. That corner case is then slower but it is harmless.
3215 */
3216 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
3217 return true;
3218
3219 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
3220 free_pages);
3221}
3222
3223bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
3224 unsigned long mark, int classzone_idx)
3225{
3226 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3227
3228 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
3229 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
3230
3231 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
3232 free_pages);
3233}
3234
3235#ifdef CONFIG_NUMA
3236static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3237{
3238 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3239 RECLAIM_DISTANCE;
3240}
3241#else /* CONFIG_NUMA */
3242static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3243{
3244 return true;
3245}
3246#endif /* CONFIG_NUMA */
3247
3248/*
3249 * get_page_from_freelist goes through the zonelist trying to allocate
3250 * a page.
3251 */
3252static struct page *
3253get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
3254 const struct alloc_context *ac)
3255{
3256 struct zoneref *z = ac->preferred_zoneref;
3257 struct zone *zone;
3258 struct pglist_data *last_pgdat_dirty_limit = NULL;
3259
3260 /*
3261 * Scan zonelist, looking for a zone with enough free.
3262 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3263 */
3264 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3265 ac->nodemask) {
3266 struct page *page;
3267 unsigned long mark;
3268
3269 if (cpusets_enabled() &&
3270 (alloc_flags & ALLOC_CPUSET) &&
3271 !__cpuset_zone_allowed(zone, gfp_mask))
3272 continue;
3273 /*
3274 * When allocating a page cache page for writing, we
3275 * want to get it from a node that is within its dirty
3276 * limit, such that no single node holds more than its
3277 * proportional share of globally allowed dirty pages.
3278 * The dirty limits take into account the node's
3279 * lowmem reserves and high watermark so that kswapd
3280 * should be able to balance it without having to
3281 * write pages from its LRU list.
3282 *
3283 * XXX: For now, allow allocations to potentially
3284 * exceed the per-node dirty limit in the slowpath
3285 * (spread_dirty_pages unset) before going into reclaim,
3286 * which is important when on a NUMA setup the allowed
3287 * nodes are together not big enough to reach the
3288 * global limit. The proper fix for these situations
3289 * will require awareness of nodes in the
3290 * dirty-throttling and the flusher threads.
3291 */
3292 if (ac->spread_dirty_pages) {
3293 if (last_pgdat_dirty_limit == zone->zone_pgdat)
3294 continue;
3295
3296 if (!node_dirty_ok(zone->zone_pgdat)) {
3297 last_pgdat_dirty_limit = zone->zone_pgdat;
3298 continue;
3299 }
3300 }
3301
3302 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
3303 if (!zone_watermark_fast(zone, order, mark,
3304 ac_classzone_idx(ac), alloc_flags)) {
3305 int ret;
3306
3307#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3308 /*
3309 * Watermark failed for this zone, but see if we can
3310 * grow this zone if it contains deferred pages.
3311 */
3312 if (static_branch_unlikely(&deferred_pages)) {
3313 if (_deferred_grow_zone(zone, order))
3314 goto try_this_zone;
3315 }
3316#endif
3317 /* Checked here to keep the fast path fast */
3318 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
3319 if (alloc_flags & ALLOC_NO_WATERMARKS)
3320 goto try_this_zone;
3321
3322 if (node_reclaim_mode == 0 ||
3323 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
3324 continue;
3325
3326 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
3327 switch (ret) {
3328 case NODE_RECLAIM_NOSCAN:
3329 /* did not scan */
3330 continue;
3331 case NODE_RECLAIM_FULL:
3332 /* scanned but unreclaimable */
3333 continue;
3334 default:
3335 /* did we reclaim enough */
3336 if (zone_watermark_ok(zone, order, mark,
3337 ac_classzone_idx(ac), alloc_flags))
3338 goto try_this_zone;
3339
3340 continue;
3341 }
3342 }
3343
3344try_this_zone:
3345 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
3346 gfp_mask, alloc_flags, ac->migratetype);
3347 if (page) {
3348 prep_new_page(page, order, gfp_mask, alloc_flags);
3349
3350 /*
3351 * If this is a high-order atomic allocation then check
3352 * if the pageblock should be reserved for the future
3353 */
3354 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3355 reserve_highatomic_pageblock(page, zone, order);
3356
3357 return page;
3358 } else {
3359#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3360 /* Try again if zone has deferred pages */
3361 if (static_branch_unlikely(&deferred_pages)) {
3362 if (_deferred_grow_zone(zone, order))
3363 goto try_this_zone;
3364 }
3365#endif
3366 }
3367 }
3368
3369 return NULL;
3370}
3371
3372/*
3373 * Large machines with many possible nodes should not always dump per-node
3374 * meminfo in irq context.
3375 */
3376static inline bool should_suppress_show_mem(void)
3377{
3378 bool ret = false;
3379
3380#if NODES_SHIFT > 8
3381 ret = in_interrupt();
3382#endif
3383 return ret;
3384}
3385
3386static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
3387{
3388 unsigned int filter = SHOW_MEM_FILTER_NODES;
3389 static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1);
3390
3391 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs))
3392 return;
3393
3394 /*
3395 * This documents exceptions given to allocations in certain
3396 * contexts that are allowed to allocate outside current's set
3397 * of allowed nodes.
3398 */
3399 if (!(gfp_mask & __GFP_NOMEMALLOC))
3400 if (tsk_is_oom_victim(current) ||
3401 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3402 filter &= ~SHOW_MEM_FILTER_NODES;
3403 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3404 filter &= ~SHOW_MEM_FILTER_NODES;
3405
3406 show_mem(filter, nodemask);
3407}
3408
3409void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
3410{
3411 struct va_format vaf;
3412 va_list args;
3413 static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL,
3414 DEFAULT_RATELIMIT_BURST);
3415
3416 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
3417 return;
3418
3419 va_start(args, fmt);
3420 vaf.fmt = fmt;
3421 vaf.va = &args;
3422 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl\n",
3423 current->comm, &vaf, gfp_mask, &gfp_mask,
3424 nodemask_pr_args(nodemask));
3425 va_end(args);
3426
3427 cpuset_print_current_mems_allowed();
3428
3429 dump_stack();
3430 warn_alloc_show_mem(gfp_mask, nodemask);
3431}
3432
3433static inline struct page *
3434__alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
3435 unsigned int alloc_flags,
3436 const struct alloc_context *ac)
3437{
3438 struct page *page;
3439
3440 page = get_page_from_freelist(gfp_mask, order,
3441 alloc_flags|ALLOC_CPUSET, ac);
3442 /*
3443 * fallback to ignore cpuset restriction if our nodes
3444 * are depleted
3445 */
3446 if (!page)
3447 page = get_page_from_freelist(gfp_mask, order,
3448 alloc_flags, ac);
3449
3450 return page;
3451}
3452
3453static inline struct page *
3454__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3455 const struct alloc_context *ac, unsigned long *did_some_progress)
3456{
3457 struct oom_control oc = {
3458 .zonelist = ac->zonelist,
3459 .nodemask = ac->nodemask,
3460 .memcg = NULL,
3461 .gfp_mask = gfp_mask,
3462 .order = order,
3463 };
3464 struct page *page;
3465
3466 *did_some_progress = 0;
3467
3468 /*
3469 * Acquire the oom lock. If that fails, somebody else is
3470 * making progress for us.
3471 */
3472 if (!mutex_trylock(&oom_lock)) {
3473 *did_some_progress = 1;
3474 schedule_timeout_uninterruptible(1);
3475 return NULL;
3476 }
3477
3478 /*
3479 * Go through the zonelist yet one more time, keep very high watermark
3480 * here, this is only to catch a parallel oom killing, we must fail if
3481 * we're still under heavy pressure. But make sure that this reclaim
3482 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3483 * allocation which will never fail due to oom_lock already held.
3484 */
3485 page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
3486 ~__GFP_DIRECT_RECLAIM, order,
3487 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3488 if (page)
3489 goto out;
3490
3491 /* Coredumps can quickly deplete all memory reserves */
3492 if (current->flags & PF_DUMPCORE)
3493 goto out;
3494 /* The OOM killer will not help higher order allocs */
3495 if (order > PAGE_ALLOC_COSTLY_ORDER)
3496 goto out;
3497 /*
3498 * We have already exhausted all our reclaim opportunities without any
3499 * success so it is time to admit defeat. We will skip the OOM killer
3500 * because it is very likely that the caller has a more reasonable
3501 * fallback than shooting a random task.
3502 */
3503 if (gfp_mask & __GFP_RETRY_MAYFAIL)
3504 goto out;
3505 /* The OOM killer does not needlessly kill tasks for lowmem */
3506 if (ac->high_zoneidx < ZONE_NORMAL)
3507 goto out;
3508 if (pm_suspended_storage())
3509 goto out;
3510 /*
3511 * XXX: GFP_NOFS allocations should rather fail than rely on
3512 * other request to make a forward progress.
3513 * We are in an unfortunate situation where out_of_memory cannot
3514 * do much for this context but let's try it to at least get
3515 * access to memory reserved if the current task is killed (see
3516 * out_of_memory). Once filesystems are ready to handle allocation
3517 * failures more gracefully we should just bail out here.
3518 */
3519
3520 /* The OOM killer may not free memory on a specific node */
3521 if (gfp_mask & __GFP_THISNODE)
3522 goto out;
3523
3524 /* Exhausted what can be done so it's blame time */
3525 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3526 *did_some_progress = 1;
3527
3528 /*
3529 * Help non-failing allocations by giving them access to memory
3530 * reserves
3531 */
3532 if (gfp_mask & __GFP_NOFAIL)
3533 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
3534 ALLOC_NO_WATERMARKS, ac);
3535 }
3536out:
3537 mutex_unlock(&oom_lock);
3538 return page;
3539}
3540
3541/*
3542 * Maximum number of compaction retries wit a progress before OOM
3543 * killer is consider as the only way to move forward.
3544 */
3545#define MAX_COMPACT_RETRIES 16
3546
3547#ifdef CONFIG_COMPACTION
3548/* Try memory compaction for high-order allocations before reclaim */
3549static struct page *
3550__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3551 unsigned int alloc_flags, const struct alloc_context *ac,
3552 enum compact_priority prio, enum compact_result *compact_result)
3553{
3554 struct page *page;
3555 unsigned int noreclaim_flag;
3556
3557 if (!order)
3558 return NULL;
3559
3560 noreclaim_flag = memalloc_noreclaim_save();
3561 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3562 prio);
3563 memalloc_noreclaim_restore(noreclaim_flag);
3564
3565 if (*compact_result <= COMPACT_INACTIVE)
3566 return NULL;
3567
3568 /*
3569 * At least in one zone compaction wasn't deferred or skipped, so let's
3570 * count a compaction stall
3571 */
3572 count_vm_event(COMPACTSTALL);
3573
3574 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3575
3576 if (page) {
3577 struct zone *zone = page_zone(page);
3578
3579 zone->compact_blockskip_flush = false;
3580 compaction_defer_reset(zone, order, true);
3581 count_vm_event(COMPACTSUCCESS);
3582 return page;
3583 }
3584
3585 /*
3586 * It's bad if compaction run occurs and fails. The most likely reason
3587 * is that pages exist, but not enough to satisfy watermarks.
3588 */
3589 count_vm_event(COMPACTFAIL);
3590
3591 cond_resched();
3592
3593 return NULL;
3594}
3595
3596static inline bool
3597should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3598 enum compact_result compact_result,
3599 enum compact_priority *compact_priority,
3600 int *compaction_retries)
3601{
3602 int max_retries = MAX_COMPACT_RETRIES;
3603 int min_priority;
3604 bool ret = false;
3605 int retries = *compaction_retries;
3606 enum compact_priority priority = *compact_priority;
3607
3608 if (!order)
3609 return false;
3610
3611 if (compaction_made_progress(compact_result))
3612 (*compaction_retries)++;
3613
3614 /*
3615 * compaction considers all the zone as desperately out of memory
3616 * so it doesn't really make much sense to retry except when the
3617 * failure could be caused by insufficient priority
3618 */
3619 if (compaction_failed(compact_result))
3620 goto check_priority;
3621
3622 /*
3623 * make sure the compaction wasn't deferred or didn't bail out early
3624 * due to locks contention before we declare that we should give up.
3625 * But do not retry if the given zonelist is not suitable for
3626 * compaction.
3627 */
3628 if (compaction_withdrawn(compact_result)) {
3629 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
3630 goto out;
3631 }
3632
3633 /*
3634 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3635 * costly ones because they are de facto nofail and invoke OOM
3636 * killer to move on while costly can fail and users are ready
3637 * to cope with that. 1/4 retries is rather arbitrary but we
3638 * would need much more detailed feedback from compaction to
3639 * make a better decision.
3640 */
3641 if (order > PAGE_ALLOC_COSTLY_ORDER)
3642 max_retries /= 4;
3643 if (*compaction_retries <= max_retries) {
3644 ret = true;
3645 goto out;
3646 }
3647
3648 /*
3649 * Make sure there are attempts at the highest priority if we exhausted
3650 * all retries or failed at the lower priorities.
3651 */
3652check_priority:
3653 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
3654 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
3655
3656 if (*compact_priority > min_priority) {
3657 (*compact_priority)--;
3658 *compaction_retries = 0;
3659 ret = true;
3660 }
3661out:
3662 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
3663 return ret;
3664}
3665#else
3666static inline struct page *
3667__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3668 unsigned int alloc_flags, const struct alloc_context *ac,
3669 enum compact_priority prio, enum compact_result *compact_result)
3670{
3671 *compact_result = COMPACT_SKIPPED;
3672 return NULL;
3673}
3674
3675static inline bool
3676should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3677 enum compact_result compact_result,
3678 enum compact_priority *compact_priority,
3679 int *compaction_retries)
3680{
3681 struct zone *zone;
3682 struct zoneref *z;
3683
3684 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
3685 return false;
3686
3687 /*
3688 * There are setups with compaction disabled which would prefer to loop
3689 * inside the allocator rather than hit the oom killer prematurely.
3690 * Let's give them a good hope and keep retrying while the order-0
3691 * watermarks are OK.
3692 */
3693 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3694 ac->nodemask) {
3695 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
3696 ac_classzone_idx(ac), alloc_flags))
3697 return true;
3698 }
3699 return false;
3700}
3701#endif /* CONFIG_COMPACTION */
3702
3703#ifdef CONFIG_LOCKDEP
3704struct lockdep_map __fs_reclaim_map =
3705 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
3706
3707static bool __need_fs_reclaim(gfp_t gfp_mask)
3708{
3709 gfp_mask = current_gfp_context(gfp_mask);
3710
3711 /* no reclaim without waiting on it */
3712 if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
3713 return false;
3714
3715 /* this guy won't enter reclaim */
3716 if (current->flags & PF_MEMALLOC)
3717 return false;
3718
3719 /* We're only interested __GFP_FS allocations for now */
3720 if (!(gfp_mask & __GFP_FS))
3721 return false;
3722
3723 if (gfp_mask & __GFP_NOLOCKDEP)
3724 return false;
3725
3726 return true;
3727}
3728
3729void fs_reclaim_acquire(gfp_t gfp_mask)
3730{
3731 if (__need_fs_reclaim(gfp_mask))
3732 lock_map_acquire(&__fs_reclaim_map);
3733}
3734EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
3735
3736void fs_reclaim_release(gfp_t gfp_mask)
3737{
3738 if (__need_fs_reclaim(gfp_mask))
3739 lock_map_release(&__fs_reclaim_map);
3740}
3741EXPORT_SYMBOL_GPL(fs_reclaim_release);
3742#endif
3743
3744/* Perform direct synchronous page reclaim */
3745static int
3746__perform_reclaim(gfp_t gfp_mask, unsigned int order,
3747 const struct alloc_context *ac)
3748{
3749 struct reclaim_state reclaim_state;
3750 int progress;
3751 unsigned int noreclaim_flag;
3752
3753 cond_resched();
3754
3755 /* We now go into synchronous reclaim */
3756 cpuset_memory_pressure_bump();
3757 noreclaim_flag = memalloc_noreclaim_save();
3758 fs_reclaim_acquire(gfp_mask);
3759 reclaim_state.reclaimed_slab = 0;
3760 current->reclaim_state = &reclaim_state;
3761
3762 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3763 ac->nodemask);
3764
3765 current->reclaim_state = NULL;
3766 fs_reclaim_release(gfp_mask);
3767 memalloc_noreclaim_restore(noreclaim_flag);
3768
3769 cond_resched();
3770
3771 return progress;
3772}
3773
3774/* The really slow allocator path where we enter direct reclaim */
3775static inline struct page *
3776__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3777 unsigned int alloc_flags, const struct alloc_context *ac,
3778 unsigned long *did_some_progress)
3779{
3780 struct page *page = NULL;
3781 bool drained = false;
3782
3783 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3784 if (unlikely(!(*did_some_progress)))
3785 return NULL;
3786
3787retry:
3788 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3789
3790 /*
3791 * If an allocation failed after direct reclaim, it could be because
3792 * pages are pinned on the per-cpu lists or in high alloc reserves.
3793 * Shrink them them and try again
3794 */
3795 if (!page && !drained) {
3796 unreserve_highatomic_pageblock(ac, false);
3797 drain_all_pages(NULL);
3798 drained = true;
3799 goto retry;
3800 }
3801
3802 return page;
3803}
3804
3805static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
3806 const struct alloc_context *ac)
3807{
3808 struct zoneref *z;
3809 struct zone *zone;
3810 pg_data_t *last_pgdat = NULL;
3811 enum zone_type high_zoneidx = ac->high_zoneidx;
3812
3813 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, high_zoneidx,
3814 ac->nodemask) {
3815 if (last_pgdat != zone->zone_pgdat)
3816 wakeup_kswapd(zone, gfp_mask, order, high_zoneidx);
3817 last_pgdat = zone->zone_pgdat;
3818 }
3819}
3820
3821static inline unsigned int
3822gfp_to_alloc_flags(gfp_t gfp_mask)
3823{
3824 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3825
3826 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3827 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3828
3829 /*
3830 * The caller may dip into page reserves a bit more if the caller
3831 * cannot run direct reclaim, or if the caller has realtime scheduling
3832 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3833 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3834 */
3835 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3836
3837 if (gfp_mask & __GFP_ATOMIC) {
3838 /*
3839 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3840 * if it can't schedule.
3841 */
3842 if (!(gfp_mask & __GFP_NOMEMALLOC))
3843 alloc_flags |= ALLOC_HARDER;
3844 /*
3845 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3846 * comment for __cpuset_node_allowed().
3847 */
3848 alloc_flags &= ~ALLOC_CPUSET;
3849 } else if (unlikely(rt_task(current)) && !in_interrupt())
3850 alloc_flags |= ALLOC_HARDER;
3851
3852#ifdef CONFIG_CMA
3853 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3854 alloc_flags |= ALLOC_CMA;
3855#endif
3856 return alloc_flags;
3857}
3858
3859static bool oom_reserves_allowed(struct task_struct *tsk)
3860{
3861 if (!tsk_is_oom_victim(tsk))
3862 return false;
3863
3864 /*
3865 * !MMU doesn't have oom reaper so give access to memory reserves
3866 * only to the thread with TIF_MEMDIE set
3867 */
3868 if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
3869 return false;
3870
3871 return true;
3872}
3873
3874/*
3875 * Distinguish requests which really need access to full memory
3876 * reserves from oom victims which can live with a portion of it
3877 */
3878static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
3879{
3880 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
3881 return 0;
3882 if (gfp_mask & __GFP_MEMALLOC)
3883 return ALLOC_NO_WATERMARKS;
3884 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3885 return ALLOC_NO_WATERMARKS;
3886 if (!in_interrupt()) {
3887 if (current->flags & PF_MEMALLOC)
3888 return ALLOC_NO_WATERMARKS;
3889 else if (oom_reserves_allowed(current))
3890 return ALLOC_OOM;
3891 }
3892
3893 return 0;
3894}
3895
3896bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3897{
3898 return !!__gfp_pfmemalloc_flags(gfp_mask);
3899}
3900
3901/*
3902 * Checks whether it makes sense to retry the reclaim to make a forward progress
3903 * for the given allocation request.
3904 *
3905 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3906 * without success, or when we couldn't even meet the watermark if we
3907 * reclaimed all remaining pages on the LRU lists.
3908 *
3909 * Returns true if a retry is viable or false to enter the oom path.
3910 */
3911static inline bool
3912should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3913 struct alloc_context *ac, int alloc_flags,
3914 bool did_some_progress, int *no_progress_loops)
3915{
3916 struct zone *zone;
3917 struct zoneref *z;
3918
3919 /*
3920 * Costly allocations might have made a progress but this doesn't mean
3921 * their order will become available due to high fragmentation so
3922 * always increment the no progress counter for them
3923 */
3924 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3925 *no_progress_loops = 0;
3926 else
3927 (*no_progress_loops)++;
3928
3929 /*
3930 * Make sure we converge to OOM if we cannot make any progress
3931 * several times in the row.
3932 */
3933 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
3934 /* Before OOM, exhaust highatomic_reserve */
3935 return unreserve_highatomic_pageblock(ac, true);
3936 }
3937
3938 /*
3939 * Keep reclaiming pages while there is a chance this will lead
3940 * somewhere. If none of the target zones can satisfy our allocation
3941 * request even if all reclaimable pages are considered then we are
3942 * screwed and have to go OOM.
3943 */
3944 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3945 ac->nodemask) {
3946 unsigned long available;
3947 unsigned long reclaimable;
3948 unsigned long min_wmark = min_wmark_pages(zone);
3949 bool wmark;
3950
3951 available = reclaimable = zone_reclaimable_pages(zone);
3952 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3953
3954 /*
3955 * Would the allocation succeed if we reclaimed all
3956 * reclaimable pages?
3957 */
3958 wmark = __zone_watermark_ok(zone, order, min_wmark,
3959 ac_classzone_idx(ac), alloc_flags, available);
3960 trace_reclaim_retry_zone(z, order, reclaimable,
3961 available, min_wmark, *no_progress_loops, wmark);
3962 if (wmark) {
3963 /*
3964 * If we didn't make any progress and have a lot of
3965 * dirty + writeback pages then we should wait for
3966 * an IO to complete to slow down the reclaim and
3967 * prevent from pre mature OOM
3968 */
3969 if (!did_some_progress) {
3970 unsigned long write_pending;
3971
3972 write_pending = zone_page_state_snapshot(zone,
3973 NR_ZONE_WRITE_PENDING);
3974
3975 if (2 * write_pending > reclaimable) {
3976 congestion_wait(BLK_RW_ASYNC, HZ/10);
3977 return true;
3978 }
3979 }
3980
3981 /*
3982 * Memory allocation/reclaim might be called from a WQ
3983 * context and the current implementation of the WQ
3984 * concurrency control doesn't recognize that
3985 * a particular WQ is congested if the worker thread is
3986 * looping without ever sleeping. Therefore we have to
3987 * do a short sleep here rather than calling
3988 * cond_resched().
3989 */
3990 if (current->flags & PF_WQ_WORKER)
3991 schedule_timeout_uninterruptible(1);
3992 else
3993 cond_resched();
3994
3995 return true;
3996 }
3997 }
3998
3999 return false;
4000}
4001
4002static inline bool
4003check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
4004{
4005 /*
4006 * It's possible that cpuset's mems_allowed and the nodemask from
4007 * mempolicy don't intersect. This should be normally dealt with by
4008 * policy_nodemask(), but it's possible to race with cpuset update in
4009 * such a way the check therein was true, and then it became false
4010 * before we got our cpuset_mems_cookie here.
4011 * This assumes that for all allocations, ac->nodemask can come only
4012 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4013 * when it does not intersect with the cpuset restrictions) or the
4014 * caller can deal with a violated nodemask.
4015 */
4016 if (cpusets_enabled() && ac->nodemask &&
4017 !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
4018 ac->nodemask = NULL;
4019 return true;
4020 }
4021
4022 /*
4023 * When updating a task's mems_allowed or mempolicy nodemask, it is
4024 * possible to race with parallel threads in such a way that our
4025 * allocation can fail while the mask is being updated. If we are about
4026 * to fail, check if the cpuset changed during allocation and if so,
4027 * retry.
4028 */
4029 if (read_mems_allowed_retry(cpuset_mems_cookie))
4030 return true;
4031
4032 return false;
4033}
4034
4035static inline struct page *
4036__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
4037 struct alloc_context *ac)
4038{
4039 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
4040 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
4041 struct page *page = NULL;
4042 unsigned int alloc_flags;
4043 unsigned long did_some_progress;
4044 enum compact_priority compact_priority;
4045 enum compact_result compact_result;
4046 int compaction_retries;
4047 int no_progress_loops;
4048 unsigned int cpuset_mems_cookie;
4049 int reserve_flags;
4050
4051 /*
4052 * In the slowpath, we sanity check order to avoid ever trying to
4053 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
4054 * be using allocators in order of preference for an area that is
4055 * too large.
4056 */
4057 if (order >= MAX_ORDER) {
4058 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4059 return NULL;
4060 }
4061
4062 /*
4063 * We also sanity check to catch abuse of atomic reserves being used by
4064 * callers that are not in atomic context.
4065 */
4066 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
4067 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
4068 gfp_mask &= ~__GFP_ATOMIC;
4069
4070retry_cpuset:
4071 compaction_retries = 0;
4072 no_progress_loops = 0;
4073 compact_priority = DEF_COMPACT_PRIORITY;
4074 cpuset_mems_cookie = read_mems_allowed_begin();
4075
4076 /*
4077 * The fast path uses conservative alloc_flags to succeed only until
4078 * kswapd needs to be woken up, and to avoid the cost of setting up
4079 * alloc_flags precisely. So we do that now.
4080 */
4081 alloc_flags = gfp_to_alloc_flags(gfp_mask);
4082
4083 /*
4084 * We need to recalculate the starting point for the zonelist iterator
4085 * because we might have used different nodemask in the fast path, or
4086 * there was a cpuset modification and we are retrying - otherwise we
4087 * could end up iterating over non-eligible zones endlessly.
4088 */
4089 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4090 ac->high_zoneidx, ac->nodemask);
4091 if (!ac->preferred_zoneref->zone)
4092 goto nopage;
4093
4094 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
4095 wake_all_kswapds(order, gfp_mask, ac);
4096
4097 /*
4098 * The adjusted alloc_flags might result in immediate success, so try
4099 * that first
4100 */
4101 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4102 if (page)
4103 goto got_pg;
4104
4105 /*
4106 * For costly allocations, try direct compaction first, as it's likely
4107 * that we have enough base pages and don't need to reclaim. For non-
4108 * movable high-order allocations, do that as well, as compaction will
4109 * try prevent permanent fragmentation by migrating from blocks of the
4110 * same migratetype.
4111 * Don't try this for allocations that are allowed to ignore
4112 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4113 */
4114 if (can_direct_reclaim &&
4115 (costly_order ||
4116 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
4117 && !gfp_pfmemalloc_allowed(gfp_mask)) {
4118 page = __alloc_pages_direct_compact(gfp_mask, order,
4119 alloc_flags, ac,
4120 INIT_COMPACT_PRIORITY,
4121 &compact_result);
4122 if (page)
4123 goto got_pg;
4124
4125 /*
4126 * Checks for costly allocations with __GFP_NORETRY, which
4127 * includes THP page fault allocations
4128 */
4129 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
4130 /*
4131 * If compaction is deferred for high-order allocations,
4132 * it is because sync compaction recently failed. If
4133 * this is the case and the caller requested a THP
4134 * allocation, we do not want to heavily disrupt the
4135 * system, so we fail the allocation instead of entering
4136 * direct reclaim.
4137 */
4138 if (compact_result == COMPACT_DEFERRED)
4139 goto nopage;
4140
4141 /*
4142 * Looks like reclaim/compaction is worth trying, but
4143 * sync compaction could be very expensive, so keep
4144 * using async compaction.
4145 */
4146 compact_priority = INIT_COMPACT_PRIORITY;
4147 }
4148 }
4149
4150retry:
4151 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4152 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
4153 wake_all_kswapds(order, gfp_mask, ac);
4154
4155 reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
4156 if (reserve_flags)
4157 alloc_flags = reserve_flags;
4158
4159 /*
4160 * Reset the zonelist iterators if memory policies can be ignored.
4161 * These allocations are high priority and system rather than user
4162 * orientated.
4163 */
4164 if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
4165 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
4166 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4167 ac->high_zoneidx, ac->nodemask);
4168 }
4169
4170 /* Attempt with potentially adjusted zonelist and alloc_flags */
4171 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4172 if (page)
4173 goto got_pg;
4174
4175 /* Caller is not willing to reclaim, we can't balance anything */
4176 if (!can_direct_reclaim)
4177 goto nopage;
4178
4179 /* Avoid recursion of direct reclaim */
4180 if (current->flags & PF_MEMALLOC)
4181 goto nopage;
4182
4183 /* Try direct reclaim and then allocating */
4184 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
4185 &did_some_progress);
4186 if (page)
4187 goto got_pg;
4188
4189 /* Try direct compaction and then allocating */
4190 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
4191 compact_priority, &compact_result);
4192 if (page)
4193 goto got_pg;
4194
4195 /* Do not loop if specifically requested */
4196 if (gfp_mask & __GFP_NORETRY)
4197 goto nopage;
4198
4199 /*
4200 * Do not retry costly high order allocations unless they are
4201 * __GFP_RETRY_MAYFAIL
4202 */
4203 if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
4204 goto nopage;
4205
4206 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
4207 did_some_progress > 0, &no_progress_loops))
4208 goto retry;
4209
4210 /*
4211 * It doesn't make any sense to retry for the compaction if the order-0
4212 * reclaim is not able to make any progress because the current
4213 * implementation of the compaction depends on the sufficient amount
4214 * of free memory (see __compaction_suitable)
4215 */
4216 if (did_some_progress > 0 &&
4217 should_compact_retry(ac, order, alloc_flags,
4218 compact_result, &compact_priority,
4219 &compaction_retries))
4220 goto retry;
4221
4222
4223 /* Deal with possible cpuset update races before we start OOM killing */
4224 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4225 goto retry_cpuset;
4226
4227 /* Reclaim has failed us, start killing things */
4228 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
4229 if (page)
4230 goto got_pg;
4231
4232 /* Avoid allocations with no watermarks from looping endlessly */
4233 if (tsk_is_oom_victim(current) &&
4234 (alloc_flags == ALLOC_OOM ||
4235 (gfp_mask & __GFP_NOMEMALLOC)))
4236 goto nopage;
4237
4238 /* Retry as long as the OOM killer is making progress */
4239 if (did_some_progress) {
4240 no_progress_loops = 0;
4241 goto retry;
4242 }
4243
4244nopage:
4245 /* Deal with possible cpuset update races before we fail */
4246 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4247 goto retry_cpuset;
4248
4249 /*
4250 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4251 * we always retry
4252 */
4253 if (gfp_mask & __GFP_NOFAIL) {
4254 /*
4255 * All existing users of the __GFP_NOFAIL are blockable, so warn
4256 * of any new users that actually require GFP_NOWAIT
4257 */
4258 if (WARN_ON_ONCE(!can_direct_reclaim))
4259 goto fail;
4260
4261 /*
4262 * PF_MEMALLOC request from this context is rather bizarre
4263 * because we cannot reclaim anything and only can loop waiting
4264 * for somebody to do a work for us
4265 */
4266 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
4267
4268 /*
4269 * non failing costly orders are a hard requirement which we
4270 * are not prepared for much so let's warn about these users
4271 * so that we can identify them and convert them to something
4272 * else.
4273 */
4274 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
4275
4276 /*
4277 * Help non-failing allocations by giving them access to memory
4278 * reserves but do not use ALLOC_NO_WATERMARKS because this
4279 * could deplete whole memory reserves which would just make
4280 * the situation worse
4281 */
4282 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
4283 if (page)
4284 goto got_pg;
4285
4286 cond_resched();
4287 goto retry;
4288 }
4289fail:
4290 warn_alloc(gfp_mask, ac->nodemask,
4291 "page allocation failure: order:%u", order);
4292got_pg:
4293 return page;
4294}
4295
4296static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
4297 int preferred_nid, nodemask_t *nodemask,
4298 struct alloc_context *ac, gfp_t *alloc_mask,
4299 unsigned int *alloc_flags)
4300{
4301 ac->high_zoneidx = gfp_zone(gfp_mask);
4302 ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
4303 ac->nodemask = nodemask;
4304 ac->migratetype = gfpflags_to_migratetype(gfp_mask);
4305
4306 if (cpusets_enabled()) {
4307 *alloc_mask |= __GFP_HARDWALL;
4308 if (!ac->nodemask)
4309 ac->nodemask = &cpuset_current_mems_allowed;
4310 else
4311 *alloc_flags |= ALLOC_CPUSET;
4312 }
4313
4314 fs_reclaim_acquire(gfp_mask);
4315 fs_reclaim_release(gfp_mask);
4316
4317 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
4318
4319 if (should_fail_alloc_page(gfp_mask, order))
4320 return false;
4321
4322 if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE)
4323 *alloc_flags |= ALLOC_CMA;
4324
4325 return true;
4326}
4327
4328/* Determine whether to spread dirty pages and what the first usable zone */
4329static inline void finalise_ac(gfp_t gfp_mask,
4330 unsigned int order, struct alloc_context *ac)
4331{
4332 /* Dirty zone balancing only done in the fast path */
4333 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
4334
4335 /*
4336 * The preferred zone is used for statistics but crucially it is
4337 * also used as the starting point for the zonelist iterator. It
4338 * may get reset for allocations that ignore memory policies.
4339 */
4340 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4341 ac->high_zoneidx, ac->nodemask);
4342}
4343
4344/*
4345 * This is the 'heart' of the zoned buddy allocator.
4346 */
4347struct page *
4348__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
4349 nodemask_t *nodemask)
4350{
4351 struct page *page;
4352 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4353 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
4354 struct alloc_context ac = { };
4355
4356 gfp_mask &= gfp_allowed_mask;
4357 alloc_mask = gfp_mask;
4358 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
4359 return NULL;
4360
4361 finalise_ac(gfp_mask, order, &ac);
4362
4363 /* First allocation attempt */
4364 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
4365 if (likely(page))
4366 goto out;
4367
4368 /*
4369 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4370 * resp. GFP_NOIO which has to be inherited for all allocation requests
4371 * from a particular context which has been marked by
4372 * memalloc_no{fs,io}_{save,restore}.
4373 */
4374 alloc_mask = current_gfp_context(gfp_mask);
4375 ac.spread_dirty_pages = false;
4376
4377 /*
4378 * Restore the original nodemask if it was potentially replaced with
4379 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4380 */
4381 if (unlikely(ac.nodemask != nodemask))
4382 ac.nodemask = nodemask;
4383
4384 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
4385
4386out:
4387 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
4388 unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
4389 __free_pages(page, order);
4390 page = NULL;
4391 }
4392
4393 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
4394
4395 return page;
4396}
4397EXPORT_SYMBOL(__alloc_pages_nodemask);
4398
4399/*
4400 * Common helper functions.
4401 */
4402unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
4403{
4404 struct page *page;
4405
4406 /*
4407 * __get_free_pages() returns a virtual address, which cannot represent
4408 * a highmem page
4409 */
4410 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
4411
4412 page = alloc_pages(gfp_mask, order);
4413 if (!page)
4414 return 0;
4415 return (unsigned long) page_address(page);
4416}
4417EXPORT_SYMBOL(__get_free_pages);
4418
4419unsigned long get_zeroed_page(gfp_t gfp_mask)
4420{
4421 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
4422}
4423EXPORT_SYMBOL(get_zeroed_page);
4424
4425void __free_pages(struct page *page, unsigned int order)
4426{
4427 if (put_page_testzero(page)) {
4428 if (order == 0)
4429 free_unref_page(page);
4430 else
4431 __free_pages_ok(page, order);
4432 }
4433}
4434
4435EXPORT_SYMBOL(__free_pages);
4436
4437void free_pages(unsigned long addr, unsigned int order)
4438{
4439 if (addr != 0) {
4440 VM_BUG_ON(!virt_addr_valid((void *)addr));
4441 __free_pages(virt_to_page((void *)addr), order);
4442 }
4443}
4444
4445EXPORT_SYMBOL(free_pages);
4446
4447/*
4448 * Page Fragment:
4449 * An arbitrary-length arbitrary-offset area of memory which resides
4450 * within a 0 or higher order page. Multiple fragments within that page
4451 * are individually refcounted, in the page's reference counter.
4452 *
4453 * The page_frag functions below provide a simple allocation framework for
4454 * page fragments. This is used by the network stack and network device
4455 * drivers to provide a backing region of memory for use as either an
4456 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4457 */
4458static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
4459 gfp_t gfp_mask)
4460{
4461 struct page *page = NULL;
4462 gfp_t gfp = gfp_mask;
4463
4464#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4465 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
4466 __GFP_NOMEMALLOC;
4467 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
4468 PAGE_FRAG_CACHE_MAX_ORDER);
4469 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
4470#endif
4471 if (unlikely(!page))
4472 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
4473
4474 nc->va = page ? page_address(page) : NULL;
4475
4476 return page;
4477}
4478
4479void __page_frag_cache_drain(struct page *page, unsigned int count)
4480{
4481 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
4482
4483 if (page_ref_sub_and_test(page, count)) {
4484 unsigned int order = compound_order(page);
4485
4486 if (order == 0)
4487 free_unref_page(page);
4488 else
4489 __free_pages_ok(page, order);
4490 }
4491}
4492EXPORT_SYMBOL(__page_frag_cache_drain);
4493
4494void *page_frag_alloc(struct page_frag_cache *nc,
4495 unsigned int fragsz, gfp_t gfp_mask)
4496{
4497 unsigned int size = PAGE_SIZE;
4498 struct page *page;
4499 int offset;
4500
4501 if (unlikely(!nc->va)) {
4502refill:
4503 page = __page_frag_cache_refill(nc, gfp_mask);
4504 if (!page)
4505 return NULL;
4506
4507#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4508 /* if size can vary use size else just use PAGE_SIZE */
4509 size = nc->size;
4510#endif
4511 /* Even if we own the page, we do not use atomic_set().
4512 * This would break get_page_unless_zero() users.
4513 */
4514 page_ref_add(page, size - 1);
4515
4516 /* reset page count bias and offset to start of new frag */
4517 nc->pfmemalloc = page_is_pfmemalloc(page);
4518 nc->pagecnt_bias = size;
4519 nc->offset = size;
4520 }
4521
4522 offset = nc->offset - fragsz;
4523 if (unlikely(offset < 0)) {
4524 page = virt_to_page(nc->va);
4525
4526 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
4527 goto refill;
4528
4529#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4530 /* if size can vary use size else just use PAGE_SIZE */
4531 size = nc->size;
4532#endif
4533 /* OK, page count is 0, we can safely set it */
4534 set_page_count(page, size);
4535
4536 /* reset page count bias and offset to start of new frag */
4537 nc->pagecnt_bias = size;
4538 offset = size - fragsz;
4539 }
4540
4541 nc->pagecnt_bias--;
4542 nc->offset = offset;
4543
4544 return nc->va + offset;
4545}
4546EXPORT_SYMBOL(page_frag_alloc);
4547
4548/*
4549 * Frees a page fragment allocated out of either a compound or order 0 page.
4550 */
4551void page_frag_free(void *addr)
4552{
4553 struct page *page = virt_to_head_page(addr);
4554
4555 if (unlikely(put_page_testzero(page)))
4556 __free_pages_ok(page, compound_order(page));
4557}
4558EXPORT_SYMBOL(page_frag_free);
4559
4560static void *make_alloc_exact(unsigned long addr, unsigned int order,
4561 size_t size)
4562{
4563 if (addr) {
4564 unsigned long alloc_end = addr + (PAGE_SIZE << order);
4565 unsigned long used = addr + PAGE_ALIGN(size);
4566
4567 split_page(virt_to_page((void *)addr), order);
4568 while (used < alloc_end) {
4569 free_page(used);
4570 used += PAGE_SIZE;
4571 }
4572 }
4573 return (void *)addr;
4574}
4575
4576/**
4577 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4578 * @size: the number of bytes to allocate
4579 * @gfp_mask: GFP flags for the allocation
4580 *
4581 * This function is similar to alloc_pages(), except that it allocates the
4582 * minimum number of pages to satisfy the request. alloc_pages() can only
4583 * allocate memory in power-of-two pages.
4584 *
4585 * This function is also limited by MAX_ORDER.
4586 *
4587 * Memory allocated by this function must be released by free_pages_exact().
4588 */
4589void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
4590{
4591 unsigned int order = get_order(size);
4592 unsigned long addr;
4593
4594 addr = __get_free_pages(gfp_mask, order);
4595 return make_alloc_exact(addr, order, size);
4596}
4597EXPORT_SYMBOL(alloc_pages_exact);
4598
4599/**
4600 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4601 * pages on a node.
4602 * @nid: the preferred node ID where memory should be allocated
4603 * @size: the number of bytes to allocate
4604 * @gfp_mask: GFP flags for the allocation
4605 *
4606 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4607 * back.
4608 */
4609void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4610{
4611 unsigned int order = get_order(size);
4612 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4613 if (!p)
4614 return NULL;
4615 return make_alloc_exact((unsigned long)page_address(p), order, size);
4616}
4617
4618/**
4619 * free_pages_exact - release memory allocated via alloc_pages_exact()
4620 * @virt: the value returned by alloc_pages_exact.
4621 * @size: size of allocation, same value as passed to alloc_pages_exact().
4622 *
4623 * Release the memory allocated by a previous call to alloc_pages_exact.
4624 */
4625void free_pages_exact(void *virt, size_t size)
4626{
4627 unsigned long addr = (unsigned long)virt;
4628 unsigned long end = addr + PAGE_ALIGN(size);
4629
4630 while (addr < end) {
4631 free_page(addr);
4632 addr += PAGE_SIZE;
4633 }
4634}
4635EXPORT_SYMBOL(free_pages_exact);
4636
4637/**
4638 * nr_free_zone_pages - count number of pages beyond high watermark
4639 * @offset: The zone index of the highest zone
4640 *
4641 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4642 * high watermark within all zones at or below a given zone index. For each
4643 * zone, the number of pages is calculated as:
4644 *
4645 * nr_free_zone_pages = managed_pages - high_pages
4646 */
4647static unsigned long nr_free_zone_pages(int offset)
4648{
4649 struct zoneref *z;
4650 struct zone *zone;
4651
4652 /* Just pick one node, since fallback list is circular */
4653 unsigned long sum = 0;
4654
4655 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4656
4657 for_each_zone_zonelist(zone, z, zonelist, offset) {
4658 unsigned long size = zone->managed_pages;
4659 unsigned long high = high_wmark_pages(zone);
4660 if (size > high)
4661 sum += size - high;
4662 }
4663
4664 return sum;
4665}
4666
4667/**
4668 * nr_free_buffer_pages - count number of pages beyond high watermark
4669 *
4670 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4671 * watermark within ZONE_DMA and ZONE_NORMAL.
4672 */
4673unsigned long nr_free_buffer_pages(void)
4674{
4675 return nr_free_zone_pages(gfp_zone(GFP_USER));
4676}
4677EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4678
4679/**
4680 * nr_free_pagecache_pages - count number of pages beyond high watermark
4681 *
4682 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4683 * high watermark within all zones.
4684 */
4685unsigned long nr_free_pagecache_pages(void)
4686{
4687 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4688}
4689
4690static inline void show_node(struct zone *zone)
4691{
4692 if (IS_ENABLED(CONFIG_NUMA))
4693 printk("Node %d ", zone_to_nid(zone));
4694}
4695
4696long si_mem_available(void)
4697{
4698 long available;
4699 unsigned long pagecache;
4700 unsigned long wmark_low = 0;
4701 unsigned long pages[NR_LRU_LISTS];
4702 struct zone *zone;
4703 int lru;
4704
4705 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4706 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
4707
4708 for_each_zone(zone)
4709 wmark_low += zone->watermark[WMARK_LOW];
4710
4711 /*
4712 * Estimate the amount of memory available for userspace allocations,
4713 * without causing swapping.
4714 */
4715 available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
4716
4717 /*
4718 * Not all the page cache can be freed, otherwise the system will
4719 * start swapping. Assume at least half of the page cache, or the
4720 * low watermark worth of cache, needs to stay.
4721 */
4722 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4723 pagecache -= min(pagecache / 2, wmark_low);
4724 available += pagecache;
4725
4726 /*
4727 * Part of the reclaimable slab consists of items that are in use,
4728 * and cannot be freed. Cap this estimate at the low watermark.
4729 */
4730 available += global_node_page_state(NR_SLAB_RECLAIMABLE) -
4731 min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2,
4732 wmark_low);
4733
4734 /*
4735 * Part of the kernel memory, which can be released under memory
4736 * pressure.
4737 */
4738 available += global_node_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES) >>
4739 PAGE_SHIFT;
4740
4741 if (available < 0)
4742 available = 0;
4743 return available;
4744}
4745EXPORT_SYMBOL_GPL(si_mem_available);
4746
4747void si_meminfo(struct sysinfo *val)
4748{
4749 val->totalram = totalram_pages;
4750 val->sharedram = global_node_page_state(NR_SHMEM);
4751 val->freeram = global_zone_page_state(NR_FREE_PAGES);
4752 val->bufferram = nr_blockdev_pages();
4753 val->totalhigh = totalhigh_pages;
4754 val->freehigh = nr_free_highpages();
4755 val->mem_unit = PAGE_SIZE;
4756}
4757
4758EXPORT_SYMBOL(si_meminfo);
4759
4760#ifdef CONFIG_NUMA
4761void si_meminfo_node(struct sysinfo *val, int nid)
4762{
4763 int zone_type; /* needs to be signed */
4764 unsigned long managed_pages = 0;
4765 unsigned long managed_highpages = 0;
4766 unsigned long free_highpages = 0;
4767 pg_data_t *pgdat = NODE_DATA(nid);
4768
4769 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4770 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4771 val->totalram = managed_pages;
4772 val->sharedram = node_page_state(pgdat, NR_SHMEM);
4773 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
4774#ifdef CONFIG_HIGHMEM
4775 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4776 struct zone *zone = &pgdat->node_zones[zone_type];
4777
4778 if (is_highmem(zone)) {
4779 managed_highpages += zone->managed_pages;
4780 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4781 }
4782 }
4783 val->totalhigh = managed_highpages;
4784 val->freehigh = free_highpages;
4785#else
4786 val->totalhigh = managed_highpages;
4787 val->freehigh = free_highpages;
4788#endif
4789 val->mem_unit = PAGE_SIZE;
4790}
4791#endif
4792
4793/*
4794 * Determine whether the node should be displayed or not, depending on whether
4795 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4796 */
4797static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
4798{
4799 if (!(flags & SHOW_MEM_FILTER_NODES))
4800 return false;
4801
4802 /*
4803 * no node mask - aka implicit memory numa policy. Do not bother with
4804 * the synchronization - read_mems_allowed_begin - because we do not
4805 * have to be precise here.
4806 */
4807 if (!nodemask)
4808 nodemask = &cpuset_current_mems_allowed;
4809
4810 return !node_isset(nid, *nodemask);
4811}
4812
4813#define K(x) ((x) << (PAGE_SHIFT-10))
4814
4815static void show_migration_types(unsigned char type)
4816{
4817 static const char types[MIGRATE_TYPES] = {
4818 [MIGRATE_UNMOVABLE] = 'U',
4819 [MIGRATE_MOVABLE] = 'M',
4820 [MIGRATE_RECLAIMABLE] = 'E',
4821 [MIGRATE_HIGHATOMIC] = 'H',
4822#ifdef CONFIG_CMA
4823 [MIGRATE_CMA] = 'C',
4824#endif
4825#ifdef CONFIG_MEMORY_ISOLATION
4826 [MIGRATE_ISOLATE] = 'I',
4827#endif
4828 };
4829 char tmp[MIGRATE_TYPES + 1];
4830 char *p = tmp;
4831 int i;
4832
4833 for (i = 0; i < MIGRATE_TYPES; i++) {
4834 if (type & (1 << i))
4835 *p++ = types[i];
4836 }
4837
4838 *p = '\0';
4839 printk(KERN_CONT "(%s) ", tmp);
4840}
4841
4842/*
4843 * Show free area list (used inside shift_scroll-lock stuff)
4844 * We also calculate the percentage fragmentation. We do this by counting the
4845 * memory on each free list with the exception of the first item on the list.
4846 *
4847 * Bits in @filter:
4848 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4849 * cpuset.
4850 */
4851void show_free_areas(unsigned int filter, nodemask_t *nodemask)
4852{
4853 unsigned long free_pcp = 0;
4854 int cpu;
4855 struct zone *zone;
4856 pg_data_t *pgdat;
4857
4858 for_each_populated_zone(zone) {
4859 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4860 continue;
4861
4862 for_each_online_cpu(cpu)
4863 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4864 }
4865
4866 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4867 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4868 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4869 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4870 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4871 " free:%lu free_pcp:%lu free_cma:%lu\n",
4872 global_node_page_state(NR_ACTIVE_ANON),
4873 global_node_page_state(NR_INACTIVE_ANON),
4874 global_node_page_state(NR_ISOLATED_ANON),
4875 global_node_page_state(NR_ACTIVE_FILE),
4876 global_node_page_state(NR_INACTIVE_FILE),
4877 global_node_page_state(NR_ISOLATED_FILE),
4878 global_node_page_state(NR_UNEVICTABLE),
4879 global_node_page_state(NR_FILE_DIRTY),
4880 global_node_page_state(NR_WRITEBACK),
4881 global_node_page_state(NR_UNSTABLE_NFS),
4882 global_node_page_state(NR_SLAB_RECLAIMABLE),
4883 global_node_page_state(NR_SLAB_UNRECLAIMABLE),
4884 global_node_page_state(NR_FILE_MAPPED),
4885 global_node_page_state(NR_SHMEM),
4886 global_zone_page_state(NR_PAGETABLE),
4887 global_zone_page_state(NR_BOUNCE),
4888 global_zone_page_state(NR_FREE_PAGES),
4889 free_pcp,
4890 global_zone_page_state(NR_FREE_CMA_PAGES));
4891
4892 for_each_online_pgdat(pgdat) {
4893 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
4894 continue;
4895
4896 printk("Node %d"
4897 " active_anon:%lukB"
4898 " inactive_anon:%lukB"
4899 " active_file:%lukB"
4900 " inactive_file:%lukB"
4901 " unevictable:%lukB"
4902 " isolated(anon):%lukB"
4903 " isolated(file):%lukB"
4904 " mapped:%lukB"
4905 " dirty:%lukB"
4906 " writeback:%lukB"
4907 " shmem:%lukB"
4908#ifdef CONFIG_TRANSPARENT_HUGEPAGE
4909 " shmem_thp: %lukB"
4910 " shmem_pmdmapped: %lukB"
4911 " anon_thp: %lukB"
4912#endif
4913 " writeback_tmp:%lukB"
4914 " unstable:%lukB"
4915 " all_unreclaimable? %s"
4916 "\n",
4917 pgdat->node_id,
4918 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
4919 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
4920 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
4921 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
4922 K(node_page_state(pgdat, NR_UNEVICTABLE)),
4923 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
4924 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
4925 K(node_page_state(pgdat, NR_FILE_MAPPED)),
4926 K(node_page_state(pgdat, NR_FILE_DIRTY)),
4927 K(node_page_state(pgdat, NR_WRITEBACK)),
4928 K(node_page_state(pgdat, NR_SHMEM)),
4929#ifdef CONFIG_TRANSPARENT_HUGEPAGE
4930 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
4931 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
4932 * HPAGE_PMD_NR),
4933 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
4934#endif
4935 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
4936 K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
4937 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
4938 "yes" : "no");
4939 }
4940
4941 for_each_populated_zone(zone) {
4942 int i;
4943
4944 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4945 continue;
4946
4947 free_pcp = 0;
4948 for_each_online_cpu(cpu)
4949 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4950
4951 show_node(zone);
4952 printk(KERN_CONT
4953 "%s"
4954 " free:%lukB"
4955 " min:%lukB"
4956 " low:%lukB"
4957 " high:%lukB"
4958 " active_anon:%lukB"
4959 " inactive_anon:%lukB"
4960 " active_file:%lukB"
4961 " inactive_file:%lukB"
4962 " unevictable:%lukB"
4963 " writepending:%lukB"
4964 " present:%lukB"
4965 " managed:%lukB"
4966 " mlocked:%lukB"
4967 " kernel_stack:%lukB"
4968 " pagetables:%lukB"
4969 " bounce:%lukB"
4970 " free_pcp:%lukB"
4971 " local_pcp:%ukB"
4972 " free_cma:%lukB"
4973 "\n",
4974 zone->name,
4975 K(zone_page_state(zone, NR_FREE_PAGES)),
4976 K(min_wmark_pages(zone)),
4977 K(low_wmark_pages(zone)),
4978 K(high_wmark_pages(zone)),
4979 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
4980 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
4981 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
4982 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
4983 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
4984 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
4985 K(zone->present_pages),
4986 K(zone->managed_pages),
4987 K(zone_page_state(zone, NR_MLOCK)),
4988 zone_page_state(zone, NR_KERNEL_STACK_KB),
4989 K(zone_page_state(zone, NR_PAGETABLE)),
4990 K(zone_page_state(zone, NR_BOUNCE)),
4991 K(free_pcp),
4992 K(this_cpu_read(zone->pageset->pcp.count)),
4993 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
4994 printk("lowmem_reserve[]:");
4995 for (i = 0; i < MAX_NR_ZONES; i++)
4996 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
4997 printk(KERN_CONT "\n");
4998 }
4999
5000 for_each_populated_zone(zone) {
5001 unsigned int order;
5002 unsigned long nr[MAX_ORDER], flags, total = 0;
5003 unsigned char types[MAX_ORDER];
5004
5005 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5006 continue;
5007 show_node(zone);
5008 printk(KERN_CONT "%s: ", zone->name);
5009
5010 spin_lock_irqsave(&zone->lock, flags);
5011 for (order = 0; order < MAX_ORDER; order++) {
5012 struct free_area *area = &zone->free_area[order];
5013 int type;
5014
5015 nr[order] = area->nr_free;
5016 total += nr[order] << order;
5017
5018 types[order] = 0;
5019 for (type = 0; type < MIGRATE_TYPES; type++) {
5020 if (!list_empty(&area->free_list[type]))
5021 types[order] |= 1 << type;
5022 }
5023 }
5024 spin_unlock_irqrestore(&zone->lock, flags);
5025 for (order = 0; order < MAX_ORDER; order++) {
5026 printk(KERN_CONT "%lu*%lukB ",
5027 nr[order], K(1UL) << order);
5028 if (nr[order])
5029 show_migration_types(types[order]);
5030 }
5031 printk(KERN_CONT "= %lukB\n", K(total));
5032 }
5033
5034 hugetlb_show_meminfo();
5035
5036 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
5037
5038 show_swap_cache_info();
5039}
5040
5041static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
5042{
5043 zoneref->zone = zone;
5044 zoneref->zone_idx = zone_idx(zone);
5045}
5046
5047/*
5048 * Builds allocation fallback zone lists.
5049 *
5050 * Add all populated zones of a node to the zonelist.
5051 */
5052static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
5053{
5054 struct zone *zone;
5055 enum zone_type zone_type = MAX_NR_ZONES;
5056 int nr_zones = 0;
5057
5058 do {
5059 zone_type--;
5060 zone = pgdat->node_zones + zone_type;
5061 if (managed_zone(zone)) {
5062 zoneref_set_zone(zone, &zonerefs[nr_zones++]);
5063 check_highest_zone(zone_type);
5064 }
5065 } while (zone_type);
5066
5067 return nr_zones;
5068}
5069
5070#ifdef CONFIG_NUMA
5071
5072static int __parse_numa_zonelist_order(char *s)
5073{
5074 /*
5075 * We used to support different zonlists modes but they turned
5076 * out to be just not useful. Let's keep the warning in place
5077 * if somebody still use the cmd line parameter so that we do
5078 * not fail it silently
5079 */
5080 if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
5081 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
5082 return -EINVAL;
5083 }
5084 return 0;
5085}
5086
5087static __init int setup_numa_zonelist_order(char *s)
5088{
5089 if (!s)
5090 return 0;
5091
5092 return __parse_numa_zonelist_order(s);
5093}
5094early_param("numa_zonelist_order", setup_numa_zonelist_order);
5095
5096char numa_zonelist_order[] = "Node";
5097
5098/*
5099 * sysctl handler for numa_zonelist_order
5100 */
5101int numa_zonelist_order_handler(struct ctl_table *table, int write,
5102 void __user *buffer, size_t *length,
5103 loff_t *ppos)
5104{
5105 char *str;
5106 int ret;
5107
5108 if (!write)
5109 return proc_dostring(table, write, buffer, length, ppos);
5110 str = memdup_user_nul(buffer, 16);
5111 if (IS_ERR(str))
5112 return PTR_ERR(str);
5113
5114 ret = __parse_numa_zonelist_order(str);
5115 kfree(str);
5116 return ret;
5117}
5118
5119
5120#define MAX_NODE_LOAD (nr_online_nodes)
5121static int node_load[MAX_NUMNODES];
5122
5123/**
5124 * find_next_best_node - find the next node that should appear in a given node's fallback list
5125 * @node: node whose fallback list we're appending
5126 * @used_node_mask: nodemask_t of already used nodes
5127 *
5128 * We use a number of factors to determine which is the next node that should
5129 * appear on a given node's fallback list. The node should not have appeared
5130 * already in @node's fallback list, and it should be the next closest node
5131 * according to the distance array (which contains arbitrary distance values
5132 * from each node to each node in the system), and should also prefer nodes
5133 * with no CPUs, since presumably they'll have very little allocation pressure
5134 * on them otherwise.
5135 * It returns -1 if no node is found.
5136 */
5137static int find_next_best_node(int node, nodemask_t *used_node_mask)
5138{
5139 int n, val;
5140 int min_val = INT_MAX;
5141 int best_node = NUMA_NO_NODE;
5142 const struct cpumask *tmp = cpumask_of_node(0);
5143
5144 /* Use the local node if we haven't already */
5145 if (!node_isset(node, *used_node_mask)) {
5146 node_set(node, *used_node_mask);
5147 return node;
5148 }
5149
5150 for_each_node_state(n, N_MEMORY) {
5151
5152 /* Don't want a node to appear more than once */
5153 if (node_isset(n, *used_node_mask))
5154 continue;
5155
5156 /* Use the distance array to find the distance */
5157 val = node_distance(node, n);
5158
5159 /* Penalize nodes under us ("prefer the next node") */
5160 val += (n < node);
5161
5162 /* Give preference to headless and unused nodes */
5163 tmp = cpumask_of_node(n);
5164 if (!cpumask_empty(tmp))
5165 val += PENALTY_FOR_NODE_WITH_CPUS;
5166
5167 /* Slight preference for less loaded node */
5168 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
5169 val += node_load[n];
5170
5171 if (val < min_val) {
5172 min_val = val;
5173 best_node = n;
5174 }
5175 }
5176
5177 if (best_node >= 0)
5178 node_set(best_node, *used_node_mask);
5179
5180 return best_node;
5181}
5182
5183
5184/*
5185 * Build zonelists ordered by node and zones within node.
5186 * This results in maximum locality--normal zone overflows into local
5187 * DMA zone, if any--but risks exhausting DMA zone.
5188 */
5189static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
5190 unsigned nr_nodes)
5191{
5192 struct zoneref *zonerefs;
5193 int i;
5194
5195 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5196
5197 for (i = 0; i < nr_nodes; i++) {
5198 int nr_zones;
5199
5200 pg_data_t *node = NODE_DATA(node_order[i]);
5201
5202 nr_zones = build_zonerefs_node(node, zonerefs);
5203 zonerefs += nr_zones;
5204 }
5205 zonerefs->zone = NULL;
5206 zonerefs->zone_idx = 0;
5207}
5208
5209/*
5210 * Build gfp_thisnode zonelists
5211 */
5212static void build_thisnode_zonelists(pg_data_t *pgdat)
5213{
5214 struct zoneref *zonerefs;
5215 int nr_zones;
5216
5217 zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
5218 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5219 zonerefs += nr_zones;
5220 zonerefs->zone = NULL;
5221 zonerefs->zone_idx = 0;
5222}
5223
5224/*
5225 * Build zonelists ordered by zone and nodes within zones.
5226 * This results in conserving DMA zone[s] until all Normal memory is
5227 * exhausted, but results in overflowing to remote node while memory
5228 * may still exist in local DMA zone.
5229 */
5230
5231static void build_zonelists(pg_data_t *pgdat)
5232{
5233 static int node_order[MAX_NUMNODES];
5234 int node, load, nr_nodes = 0;
5235 nodemask_t used_mask;
5236 int local_node, prev_node;
5237
5238 /* NUMA-aware ordering of nodes */
5239 local_node = pgdat->node_id;
5240 load = nr_online_nodes;
5241 prev_node = local_node;
5242 nodes_clear(used_mask);
5243
5244 memset(node_order, 0, sizeof(node_order));
5245 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
5246 /*
5247 * We don't want to pressure a particular node.
5248 * So adding penalty to the first node in same
5249 * distance group to make it round-robin.
5250 */
5251 if (node_distance(local_node, node) !=
5252 node_distance(local_node, prev_node))
5253 node_load[node] = load;
5254
5255 node_order[nr_nodes++] = node;
5256 prev_node = node;
5257 load--;
5258 }
5259
5260 build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
5261 build_thisnode_zonelists(pgdat);
5262}
5263
5264#ifdef CONFIG_HAVE_MEMORYLESS_NODES
5265/*
5266 * Return node id of node used for "local" allocations.
5267 * I.e., first node id of first zone in arg node's generic zonelist.
5268 * Used for initializing percpu 'numa_mem', which is used primarily
5269 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5270 */
5271int local_memory_node(int node)
5272{
5273 struct zoneref *z;
5274
5275 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
5276 gfp_zone(GFP_KERNEL),
5277 NULL);
5278 return z->zone->node;
5279}
5280#endif
5281
5282static void setup_min_unmapped_ratio(void);
5283static void setup_min_slab_ratio(void);
5284#else /* CONFIG_NUMA */
5285
5286static void build_zonelists(pg_data_t *pgdat)
5287{
5288 int node, local_node;
5289 struct zoneref *zonerefs;
5290 int nr_zones;
5291
5292 local_node = pgdat->node_id;
5293
5294 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5295 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5296 zonerefs += nr_zones;
5297
5298 /*
5299 * Now we build the zonelist so that it contains the zones
5300 * of all the other nodes.
5301 * We don't want to pressure a particular node, so when
5302 * building the zones for node N, we make sure that the
5303 * zones coming right after the local ones are those from
5304 * node N+1 (modulo N)
5305 */
5306 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
5307 if (!node_online(node))
5308 continue;
5309 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5310 zonerefs += nr_zones;
5311 }
5312 for (node = 0; node < local_node; node++) {
5313 if (!node_online(node))
5314 continue;
5315 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5316 zonerefs += nr_zones;
5317 }
5318
5319 zonerefs->zone = NULL;
5320 zonerefs->zone_idx = 0;
5321}
5322
5323#endif /* CONFIG_NUMA */
5324
5325/*
5326 * Boot pageset table. One per cpu which is going to be used for all
5327 * zones and all nodes. The parameters will be set in such a way
5328 * that an item put on a list will immediately be handed over to
5329 * the buddy list. This is safe since pageset manipulation is done
5330 * with interrupts disabled.
5331 *
5332 * The boot_pagesets must be kept even after bootup is complete for
5333 * unused processors and/or zones. They do play a role for bootstrapping
5334 * hotplugged processors.
5335 *
5336 * zoneinfo_show() and maybe other functions do
5337 * not check if the processor is online before following the pageset pointer.
5338 * Other parts of the kernel may not check if the zone is available.
5339 */
5340static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
5341static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
5342static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
5343
5344static void __build_all_zonelists(void *data)
5345{
5346 int nid;
5347 int __maybe_unused cpu;
5348 pg_data_t *self = data;
5349 static DEFINE_SPINLOCK(lock);
5350
5351 spin_lock(&lock);
5352
5353#ifdef CONFIG_NUMA
5354 memset(node_load, 0, sizeof(node_load));
5355#endif
5356
5357 /*
5358 * This node is hotadded and no memory is yet present. So just
5359 * building zonelists is fine - no need to touch other nodes.
5360 */
5361 if (self && !node_online(self->node_id)) {
5362 build_zonelists(self);
5363 } else {
5364 for_each_online_node(nid) {
5365 pg_data_t *pgdat = NODE_DATA(nid);
5366
5367 build_zonelists(pgdat);
5368 }
5369
5370#ifdef CONFIG_HAVE_MEMORYLESS_NODES
5371 /*
5372 * We now know the "local memory node" for each node--
5373 * i.e., the node of the first zone in the generic zonelist.
5374 * Set up numa_mem percpu variable for on-line cpus. During
5375 * boot, only the boot cpu should be on-line; we'll init the
5376 * secondary cpus' numa_mem as they come on-line. During
5377 * node/memory hotplug, we'll fixup all on-line cpus.
5378 */
5379 for_each_online_cpu(cpu)
5380 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
5381#endif
5382 }
5383
5384 spin_unlock(&lock);
5385}
5386
5387static noinline void __init
5388build_all_zonelists_init(void)
5389{
5390 int cpu;
5391
5392 __build_all_zonelists(NULL);
5393
5394 /*
5395 * Initialize the boot_pagesets that are going to be used
5396 * for bootstrapping processors. The real pagesets for
5397 * each zone will be allocated later when the per cpu
5398 * allocator is available.
5399 *
5400 * boot_pagesets are used also for bootstrapping offline
5401 * cpus if the system is already booted because the pagesets
5402 * are needed to initialize allocators on a specific cpu too.
5403 * F.e. the percpu allocator needs the page allocator which
5404 * needs the percpu allocator in order to allocate its pagesets
5405 * (a chicken-egg dilemma).
5406 */
5407 for_each_possible_cpu(cpu)
5408 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
5409
5410 mminit_verify_zonelist();
5411 cpuset_init_current_mems_allowed();
5412}
5413
5414/*
5415 * unless system_state == SYSTEM_BOOTING.
5416 *
5417 * __ref due to call of __init annotated helper build_all_zonelists_init
5418 * [protected by SYSTEM_BOOTING].
5419 */
5420void __ref build_all_zonelists(pg_data_t *pgdat)
5421{
5422 if (system_state == SYSTEM_BOOTING) {
5423 build_all_zonelists_init();
5424 } else {
5425 __build_all_zonelists(pgdat);
5426 /* cpuset refresh routine should be here */
5427 }
5428 vm_total_pages = nr_free_pagecache_pages();
5429 /*
5430 * Disable grouping by mobility if the number of pages in the
5431 * system is too low to allow the mechanism to work. It would be
5432 * more accurate, but expensive to check per-zone. This check is
5433 * made on memory-hotadd so a system can start with mobility
5434 * disabled and enable it later
5435 */
5436 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5437 page_group_by_mobility_disabled = 1;
5438 else
5439 page_group_by_mobility_disabled = 0;
5440
5441 pr_info("Built %i zonelists, mobility grouping %s. Total pages: %ld\n",
5442 nr_online_nodes,
5443 page_group_by_mobility_disabled ? "off" : "on",
5444 vm_total_pages);
5445#ifdef CONFIG_NUMA
5446 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5447#endif
5448}
5449
5450/*
5451 * Initially all pages are reserved - free ones are freed
5452 * up by free_all_bootmem() once the early boot process is
5453 * done. Non-atomic initialization, single-pass.
5454 */
5455void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5456 unsigned long start_pfn, enum memmap_context context,
5457 struct vmem_altmap *altmap)
5458{
5459 unsigned long end_pfn = start_pfn + size;
5460 pg_data_t *pgdat = NODE_DATA(nid);
5461 unsigned long pfn;
5462 unsigned long nr_initialised = 0;
5463 struct page *page;
5464#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5465 struct memblock_region *r = NULL, *tmp;
5466#endif
5467
5468 if (highest_memmap_pfn < end_pfn - 1)
5469 highest_memmap_pfn = end_pfn - 1;
5470
5471 /*
5472 * Honor reservation requested by the driver for this ZONE_DEVICE
5473 * memory
5474 */
5475 if (altmap && start_pfn == altmap->base_pfn)
5476 start_pfn += altmap->reserve;
5477
5478 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5479 /*
5480 * There can be holes in boot-time mem_map[]s handed to this
5481 * function. They do not exist on hotplugged memory.
5482 */
5483 if (context != MEMMAP_EARLY)
5484 goto not_early;
5485
5486 if (!early_pfn_valid(pfn))
5487 continue;
5488 if (!early_pfn_in_nid(pfn, nid))
5489 continue;
5490 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5491 break;
5492
5493#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5494 /*
5495 * Check given memblock attribute by firmware which can affect
5496 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5497 * mirrored, it's an overlapped memmap init. skip it.
5498 */
5499 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5500 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5501 for_each_memblock(memory, tmp)
5502 if (pfn < memblock_region_memory_end_pfn(tmp))
5503 break;
5504 r = tmp;
5505 }
5506 if (pfn >= memblock_region_memory_base_pfn(r) &&
5507 memblock_is_mirror(r)) {
5508 /* already initialized as NORMAL */
5509 pfn = memblock_region_memory_end_pfn(r);
5510 continue;
5511 }
5512 }
5513#endif
5514
5515not_early:
5516 page = pfn_to_page(pfn);
5517 __init_single_page(page, pfn, zone, nid);
5518 if (context == MEMMAP_HOTPLUG)
5519 SetPageReserved(page);
5520
5521 /*
5522 * Mark the block movable so that blocks are reserved for
5523 * movable at startup. This will force kernel allocations
5524 * to reserve their blocks rather than leaking throughout
5525 * the address space during boot when many long-lived
5526 * kernel allocations are made.
5527 *
5528 * bitmap is created for zone's valid pfn range. but memmap
5529 * can be created for invalid pages (for alignment)
5530 * check here not to call set_pageblock_migratetype() against
5531 * pfn out of zone.
5532 *
5533 * Please note that MEMMAP_HOTPLUG path doesn't clear memmap
5534 * because this is done early in sparse_add_one_section
5535 */
5536 if (!(pfn & (pageblock_nr_pages - 1))) {
5537 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5538 cond_resched();
5539 }
5540 }
5541}
5542
5543static void __meminit zone_init_free_lists(struct zone *zone)
5544{
5545 unsigned int order, t;
5546 for_each_migratetype_order(order, t) {
5547 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5548 zone->free_area[order].nr_free = 0;
5549 }
5550}
5551
5552#ifndef __HAVE_ARCH_MEMMAP_INIT
5553#define memmap_init(size, nid, zone, start_pfn) \
5554 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY, NULL)
5555#endif
5556
5557static int zone_batchsize(struct zone *zone)
5558{
5559#ifdef CONFIG_MMU
5560 int batch;
5561
5562 /*
5563 * The per-cpu-pages pools are set to around 1000th of the
5564 * size of the zone. But no more than 1/2 of a meg.
5565 *
5566 * OK, so we don't know how big the cache is. So guess.
5567 */
5568 batch = zone->managed_pages / 1024;
5569 if (batch * PAGE_SIZE > 512 * 1024)
5570 batch = (512 * 1024) / PAGE_SIZE;
5571 batch /= 4; /* We effectively *= 4 below */
5572 if (batch < 1)
5573 batch = 1;
5574
5575 /*
5576 * Clamp the batch to a 2^n - 1 value. Having a power
5577 * of 2 value was found to be more likely to have
5578 * suboptimal cache aliasing properties in some cases.
5579 *
5580 * For example if 2 tasks are alternately allocating
5581 * batches of pages, one task can end up with a lot
5582 * of pages of one half of the possible page colors
5583 * and the other with pages of the other colors.
5584 */
5585 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5586
5587 return batch;
5588
5589#else
5590 /* The deferral and batching of frees should be suppressed under NOMMU
5591 * conditions.
5592 *
5593 * The problem is that NOMMU needs to be able to allocate large chunks
5594 * of contiguous memory as there's no hardware page translation to
5595 * assemble apparent contiguous memory from discontiguous pages.
5596 *
5597 * Queueing large contiguous runs of pages for batching, however,
5598 * causes the pages to actually be freed in smaller chunks. As there
5599 * can be a significant delay between the individual batches being
5600 * recycled, this leads to the once large chunks of space being
5601 * fragmented and becoming unavailable for high-order allocations.
5602 */
5603 return 0;
5604#endif
5605}
5606
5607/*
5608 * pcp->high and pcp->batch values are related and dependent on one another:
5609 * ->batch must never be higher then ->high.
5610 * The following function updates them in a safe manner without read side
5611 * locking.
5612 *
5613 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5614 * those fields changing asynchronously (acording the the above rule).
5615 *
5616 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5617 * outside of boot time (or some other assurance that no concurrent updaters
5618 * exist).
5619 */
5620static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5621 unsigned long batch)
5622{
5623 /* start with a fail safe value for batch */
5624 pcp->batch = 1;
5625 smp_wmb();
5626
5627 /* Update high, then batch, in order */
5628 pcp->high = high;
5629 smp_wmb();
5630
5631 pcp->batch = batch;
5632}
5633
5634/* a companion to pageset_set_high() */
5635static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5636{
5637 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5638}
5639
5640static void pageset_init(struct per_cpu_pageset *p)
5641{
5642 struct per_cpu_pages *pcp;
5643 int migratetype;
5644
5645 memset(p, 0, sizeof(*p));
5646
5647 pcp = &p->pcp;
5648 pcp->count = 0;
5649 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5650 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5651}
5652
5653static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5654{
5655 pageset_init(p);
5656 pageset_set_batch(p, batch);
5657}
5658
5659/*
5660 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5661 * to the value high for the pageset p.
5662 */
5663static void pageset_set_high(struct per_cpu_pageset *p,
5664 unsigned long high)
5665{
5666 unsigned long batch = max(1UL, high / 4);
5667 if ((high / 4) > (PAGE_SHIFT * 8))
5668 batch = PAGE_SHIFT * 8;
5669
5670 pageset_update(&p->pcp, high, batch);
5671}
5672
5673static void pageset_set_high_and_batch(struct zone *zone,
5674 struct per_cpu_pageset *pcp)
5675{
5676 if (percpu_pagelist_fraction)
5677 pageset_set_high(pcp,
5678 (zone->managed_pages /
5679 percpu_pagelist_fraction));
5680 else
5681 pageset_set_batch(pcp, zone_batchsize(zone));
5682}
5683
5684static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5685{
5686 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5687
5688 pageset_init(pcp);
5689 pageset_set_high_and_batch(zone, pcp);
5690}
5691
5692void __meminit setup_zone_pageset(struct zone *zone)
5693{
5694 int cpu;
5695 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5696 for_each_possible_cpu(cpu)
5697 zone_pageset_init(zone, cpu);
5698}
5699
5700/*
5701 * Allocate per cpu pagesets and initialize them.
5702 * Before this call only boot pagesets were available.
5703 */
5704void __init setup_per_cpu_pageset(void)
5705{
5706 struct pglist_data *pgdat;
5707 struct zone *zone;
5708
5709 for_each_populated_zone(zone)
5710 setup_zone_pageset(zone);
5711
5712 for_each_online_pgdat(pgdat)
5713 pgdat->per_cpu_nodestats =
5714 alloc_percpu(struct per_cpu_nodestat);
5715}
5716
5717static __meminit void zone_pcp_init(struct zone *zone)
5718{
5719 /*
5720 * per cpu subsystem is not up at this point. The following code
5721 * relies on the ability of the linker to provide the
5722 * offset of a (static) per cpu variable into the per cpu area.
5723 */
5724 zone->pageset = &boot_pageset;
5725
5726 if (populated_zone(zone))
5727 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5728 zone->name, zone->present_pages,
5729 zone_batchsize(zone));
5730}
5731
5732void __meminit init_currently_empty_zone(struct zone *zone,
5733 unsigned long zone_start_pfn,
5734 unsigned long size)
5735{
5736 struct pglist_data *pgdat = zone->zone_pgdat;
5737
5738 pgdat->nr_zones = zone_idx(zone) + 1;
5739
5740 zone->zone_start_pfn = zone_start_pfn;
5741
5742 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5743 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5744 pgdat->node_id,
5745 (unsigned long)zone_idx(zone),
5746 zone_start_pfn, (zone_start_pfn + size));
5747
5748 zone_init_free_lists(zone);
5749 zone->initialized = 1;
5750}
5751
5752#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5753#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5754
5755/*
5756 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5757 */
5758int __meminit __early_pfn_to_nid(unsigned long pfn,
5759 struct mminit_pfnnid_cache *state)
5760{
5761 unsigned long start_pfn, end_pfn;
5762 int nid;
5763
5764 if (state->last_start <= pfn && pfn < state->last_end)
5765 return state->last_nid;
5766
5767 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5768 if (nid != -1) {
5769 state->last_start = start_pfn;
5770 state->last_end = end_pfn;
5771 state->last_nid = nid;
5772 }
5773
5774 return nid;
5775}
5776#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5777
5778/**
5779 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5780 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5781 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5782 *
5783 * If an architecture guarantees that all ranges registered contain no holes
5784 * and may be freed, this this function may be used instead of calling
5785 * memblock_free_early_nid() manually.
5786 */
5787void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5788{
5789 unsigned long start_pfn, end_pfn;
5790 int i, this_nid;
5791
5792 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5793 start_pfn = min(start_pfn, max_low_pfn);
5794 end_pfn = min(end_pfn, max_low_pfn);
5795
5796 if (start_pfn < end_pfn)
5797 memblock_free_early_nid(PFN_PHYS(start_pfn),
5798 (end_pfn - start_pfn) << PAGE_SHIFT,
5799 this_nid);
5800 }
5801}
5802
5803/**
5804 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5805 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5806 *
5807 * If an architecture guarantees that all ranges registered contain no holes and may
5808 * be freed, this function may be used instead of calling memory_present() manually.
5809 */
5810void __init sparse_memory_present_with_active_regions(int nid)
5811{
5812 unsigned long start_pfn, end_pfn;
5813 int i, this_nid;
5814
5815 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5816 memory_present(this_nid, start_pfn, end_pfn);
5817}
5818
5819/**
5820 * get_pfn_range_for_nid - Return the start and end page frames for a node
5821 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5822 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5823 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5824 *
5825 * It returns the start and end page frame of a node based on information
5826 * provided by memblock_set_node(). If called for a node
5827 * with no available memory, a warning is printed and the start and end
5828 * PFNs will be 0.
5829 */
5830void __meminit get_pfn_range_for_nid(unsigned int nid,
5831 unsigned long *start_pfn, unsigned long *end_pfn)
5832{
5833 unsigned long this_start_pfn, this_end_pfn;
5834 int i;
5835
5836 *start_pfn = -1UL;
5837 *end_pfn = 0;
5838
5839 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5840 *start_pfn = min(*start_pfn, this_start_pfn);
5841 *end_pfn = max(*end_pfn, this_end_pfn);
5842 }
5843
5844 if (*start_pfn == -1UL)
5845 *start_pfn = 0;
5846}
5847
5848/*
5849 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5850 * assumption is made that zones within a node are ordered in monotonic
5851 * increasing memory addresses so that the "highest" populated zone is used
5852 */
5853static void __init find_usable_zone_for_movable(void)
5854{
5855 int zone_index;
5856 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5857 if (zone_index == ZONE_MOVABLE)
5858 continue;
5859
5860 if (arch_zone_highest_possible_pfn[zone_index] >
5861 arch_zone_lowest_possible_pfn[zone_index])
5862 break;
5863 }
5864
5865 VM_BUG_ON(zone_index == -1);
5866 movable_zone = zone_index;
5867}
5868
5869/*
5870 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5871 * because it is sized independent of architecture. Unlike the other zones,
5872 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5873 * in each node depending on the size of each node and how evenly kernelcore
5874 * is distributed. This helper function adjusts the zone ranges
5875 * provided by the architecture for a given node by using the end of the
5876 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5877 * zones within a node are in order of monotonic increases memory addresses
5878 */
5879static void __meminit adjust_zone_range_for_zone_movable(int nid,
5880 unsigned long zone_type,
5881 unsigned long node_start_pfn,
5882 unsigned long node_end_pfn,
5883 unsigned long *zone_start_pfn,
5884 unsigned long *zone_end_pfn)
5885{
5886 /* Only adjust if ZONE_MOVABLE is on this node */
5887 if (zone_movable_pfn[nid]) {
5888 /* Size ZONE_MOVABLE */
5889 if (zone_type == ZONE_MOVABLE) {
5890 *zone_start_pfn = zone_movable_pfn[nid];
5891 *zone_end_pfn = min(node_end_pfn,
5892 arch_zone_highest_possible_pfn[movable_zone]);
5893
5894 /* Adjust for ZONE_MOVABLE starting within this range */
5895 } else if (!mirrored_kernelcore &&
5896 *zone_start_pfn < zone_movable_pfn[nid] &&
5897 *zone_end_pfn > zone_movable_pfn[nid]) {
5898 *zone_end_pfn = zone_movable_pfn[nid];
5899
5900 /* Check if this whole range is within ZONE_MOVABLE */
5901 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5902 *zone_start_pfn = *zone_end_pfn;
5903 }
5904}
5905
5906/*
5907 * Return the number of pages a zone spans in a node, including holes
5908 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5909 */
5910static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5911 unsigned long zone_type,
5912 unsigned long node_start_pfn,
5913 unsigned long node_end_pfn,
5914 unsigned long *zone_start_pfn,
5915 unsigned long *zone_end_pfn,
5916 unsigned long *ignored)
5917{
5918 /* When hotadd a new node from cpu_up(), the node should be empty */
5919 if (!node_start_pfn && !node_end_pfn)
5920 return 0;
5921
5922 /* Get the start and end of the zone */
5923 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5924 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5925 adjust_zone_range_for_zone_movable(nid, zone_type,
5926 node_start_pfn, node_end_pfn,
5927 zone_start_pfn, zone_end_pfn);
5928
5929 /* Check that this node has pages within the zone's required range */
5930 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5931 return 0;
5932
5933 /* Move the zone boundaries inside the node if necessary */
5934 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5935 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5936
5937 /* Return the spanned pages */
5938 return *zone_end_pfn - *zone_start_pfn;
5939}
5940
5941/*
5942 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5943 * then all holes in the requested range will be accounted for.
5944 */
5945unsigned long __meminit __absent_pages_in_range(int nid,
5946 unsigned long range_start_pfn,
5947 unsigned long range_end_pfn)
5948{
5949 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5950 unsigned long start_pfn, end_pfn;
5951 int i;
5952
5953 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5954 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5955 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5956 nr_absent -= end_pfn - start_pfn;
5957 }
5958 return nr_absent;
5959}
5960
5961/**
5962 * absent_pages_in_range - Return number of page frames in holes within a range
5963 * @start_pfn: The start PFN to start searching for holes
5964 * @end_pfn: The end PFN to stop searching for holes
5965 *
5966 * It returns the number of pages frames in memory holes within a range.
5967 */
5968unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5969 unsigned long end_pfn)
5970{
5971 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5972}
5973
5974/* Return the number of page frames in holes in a zone on a node */
5975static unsigned long __meminit zone_absent_pages_in_node(int nid,
5976 unsigned long zone_type,
5977 unsigned long node_start_pfn,
5978 unsigned long node_end_pfn,
5979 unsigned long *ignored)
5980{
5981 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5982 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5983 unsigned long zone_start_pfn, zone_end_pfn;
5984 unsigned long nr_absent;
5985
5986 /* When hotadd a new node from cpu_up(), the node should be empty */
5987 if (!node_start_pfn && !node_end_pfn)
5988 return 0;
5989
5990 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5991 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5992
5993 adjust_zone_range_for_zone_movable(nid, zone_type,
5994 node_start_pfn, node_end_pfn,
5995 &zone_start_pfn, &zone_end_pfn);
5996 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5997
5998 /*
5999 * ZONE_MOVABLE handling.
6000 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6001 * and vice versa.
6002 */
6003 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
6004 unsigned long start_pfn, end_pfn;
6005 struct memblock_region *r;
6006
6007 for_each_memblock(memory, r) {
6008 start_pfn = clamp(memblock_region_memory_base_pfn(r),
6009 zone_start_pfn, zone_end_pfn);
6010 end_pfn = clamp(memblock_region_memory_end_pfn(r),
6011 zone_start_pfn, zone_end_pfn);
6012
6013 if (zone_type == ZONE_MOVABLE &&
6014 memblock_is_mirror(r))
6015 nr_absent += end_pfn - start_pfn;
6016
6017 if (zone_type == ZONE_NORMAL &&
6018 !memblock_is_mirror(r))
6019 nr_absent += end_pfn - start_pfn;
6020 }
6021 }
6022
6023 return nr_absent;
6024}
6025
6026#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6027static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
6028 unsigned long zone_type,
6029 unsigned long node_start_pfn,
6030 unsigned long node_end_pfn,
6031 unsigned long *zone_start_pfn,
6032 unsigned long *zone_end_pfn,
6033 unsigned long *zones_size)
6034{
6035 unsigned int zone;
6036
6037 *zone_start_pfn = node_start_pfn;
6038 for (zone = 0; zone < zone_type; zone++)
6039 *zone_start_pfn += zones_size[zone];
6040
6041 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
6042
6043 return zones_size[zone_type];
6044}
6045
6046static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
6047 unsigned long zone_type,
6048 unsigned long node_start_pfn,
6049 unsigned long node_end_pfn,
6050 unsigned long *zholes_size)
6051{
6052 if (!zholes_size)
6053 return 0;
6054
6055 return zholes_size[zone_type];
6056}
6057
6058#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6059
6060static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
6061 unsigned long node_start_pfn,
6062 unsigned long node_end_pfn,
6063 unsigned long *zones_size,
6064 unsigned long *zholes_size)
6065{
6066 unsigned long realtotalpages = 0, totalpages = 0;
6067 enum zone_type i;
6068
6069 for (i = 0; i < MAX_NR_ZONES; i++) {
6070 struct zone *zone = pgdat->node_zones + i;
6071 unsigned long zone_start_pfn, zone_end_pfn;
6072 unsigned long size, real_size;
6073
6074 size = zone_spanned_pages_in_node(pgdat->node_id, i,
6075 node_start_pfn,
6076 node_end_pfn,
6077 &zone_start_pfn,
6078 &zone_end_pfn,
6079 zones_size);
6080 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
6081 node_start_pfn, node_end_pfn,
6082 zholes_size);
6083 if (size)
6084 zone->zone_start_pfn = zone_start_pfn;
6085 else
6086 zone->zone_start_pfn = 0;
6087 zone->spanned_pages = size;
6088 zone->present_pages = real_size;
6089
6090 totalpages += size;
6091 realtotalpages += real_size;
6092 }
6093
6094 pgdat->node_spanned_pages = totalpages;
6095 pgdat->node_present_pages = realtotalpages;
6096 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
6097 realtotalpages);
6098}
6099
6100#ifndef CONFIG_SPARSEMEM
6101/*
6102 * Calculate the size of the zone->blockflags rounded to an unsigned long
6103 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6104 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6105 * round what is now in bits to nearest long in bits, then return it in
6106 * bytes.
6107 */
6108static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
6109{
6110 unsigned long usemapsize;
6111
6112 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
6113 usemapsize = roundup(zonesize, pageblock_nr_pages);
6114 usemapsize = usemapsize >> pageblock_order;
6115 usemapsize *= NR_PAGEBLOCK_BITS;
6116 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
6117
6118 return usemapsize / 8;
6119}
6120
6121static void __init setup_usemap(struct pglist_data *pgdat,
6122 struct zone *zone,
6123 unsigned long zone_start_pfn,
6124 unsigned long zonesize)
6125{
6126 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
6127 zone->pageblock_flags = NULL;
6128 if (usemapsize)
6129 zone->pageblock_flags =
6130 memblock_virt_alloc_node_nopanic(usemapsize,
6131 pgdat->node_id);
6132}
6133#else
6134static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
6135 unsigned long zone_start_pfn, unsigned long zonesize) {}
6136#endif /* CONFIG_SPARSEMEM */
6137
6138#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6139
6140/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6141void __paginginit set_pageblock_order(void)
6142{
6143 unsigned int order;
6144
6145 /* Check that pageblock_nr_pages has not already been setup */
6146 if (pageblock_order)
6147 return;
6148
6149 if (HPAGE_SHIFT > PAGE_SHIFT)
6150 order = HUGETLB_PAGE_ORDER;
6151 else
6152 order = MAX_ORDER - 1;
6153
6154 /*
6155 * Assume the largest contiguous order of interest is a huge page.
6156 * This value may be variable depending on boot parameters on IA64 and
6157 * powerpc.
6158 */
6159 pageblock_order = order;
6160}
6161#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6162
6163/*
6164 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6165 * is unused as pageblock_order is set at compile-time. See
6166 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6167 * the kernel config
6168 */
6169void __paginginit set_pageblock_order(void)
6170{
6171}
6172
6173#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6174
6175static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
6176 unsigned long present_pages)
6177{
6178 unsigned long pages = spanned_pages;
6179
6180 /*
6181 * Provide a more accurate estimation if there are holes within
6182 * the zone and SPARSEMEM is in use. If there are holes within the
6183 * zone, each populated memory region may cost us one or two extra
6184 * memmap pages due to alignment because memmap pages for each
6185 * populated regions may not be naturally aligned on page boundary.
6186 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6187 */
6188 if (spanned_pages > present_pages + (present_pages >> 4) &&
6189 IS_ENABLED(CONFIG_SPARSEMEM))
6190 pages = present_pages;
6191
6192 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
6193}
6194
6195/*
6196 * Set up the zone data structures:
6197 * - mark all pages reserved
6198 * - mark all memory queues empty
6199 * - clear the memory bitmaps
6200 *
6201 * NOTE: pgdat should get zeroed by caller.
6202 */
6203static void __paginginit free_area_init_core(struct pglist_data *pgdat)
6204{
6205 enum zone_type j;
6206 int nid = pgdat->node_id;
6207
6208 pgdat_resize_init(pgdat);
6209#ifdef CONFIG_NUMA_BALANCING
6210 spin_lock_init(&pgdat->numabalancing_migrate_lock);
6211 pgdat->numabalancing_migrate_nr_pages = 0;
6212 pgdat->numabalancing_migrate_next_window = jiffies;
6213#endif
6214#ifdef CONFIG_TRANSPARENT_HUGEPAGE
6215 spin_lock_init(&pgdat->split_queue_lock);
6216 INIT_LIST_HEAD(&pgdat->split_queue);
6217 pgdat->split_queue_len = 0;
6218#endif
6219 init_waitqueue_head(&pgdat->kswapd_wait);
6220 init_waitqueue_head(&pgdat->pfmemalloc_wait);
6221#ifdef CONFIG_COMPACTION
6222 init_waitqueue_head(&pgdat->kcompactd_wait);
6223#endif
6224 pgdat_page_ext_init(pgdat);
6225 spin_lock_init(&pgdat->lru_lock);
6226 lruvec_init(node_lruvec(pgdat));
6227
6228 pgdat->per_cpu_nodestats = &boot_nodestats;
6229
6230 for (j = 0; j < MAX_NR_ZONES; j++) {
6231 struct zone *zone = pgdat->node_zones + j;
6232 unsigned long size, realsize, freesize, memmap_pages;
6233 unsigned long zone_start_pfn = zone->zone_start_pfn;
6234
6235 size = zone->spanned_pages;
6236 realsize = freesize = zone->present_pages;
6237
6238 /*
6239 * Adjust freesize so that it accounts for how much memory
6240 * is used by this zone for memmap. This affects the watermark
6241 * and per-cpu initialisations
6242 */
6243 memmap_pages = calc_memmap_size(size, realsize);
6244 if (!is_highmem_idx(j)) {
6245 if (freesize >= memmap_pages) {
6246 freesize -= memmap_pages;
6247 if (memmap_pages)
6248 printk(KERN_DEBUG
6249 " %s zone: %lu pages used for memmap\n",
6250 zone_names[j], memmap_pages);
6251 } else
6252 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6253 zone_names[j], memmap_pages, freesize);
6254 }
6255
6256 /* Account for reserved pages */
6257 if (j == 0 && freesize > dma_reserve) {
6258 freesize -= dma_reserve;
6259 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
6260 zone_names[0], dma_reserve);
6261 }
6262
6263 if (!is_highmem_idx(j))
6264 nr_kernel_pages += freesize;
6265 /* Charge for highmem memmap if there are enough kernel pages */
6266 else if (nr_kernel_pages > memmap_pages * 2)
6267 nr_kernel_pages -= memmap_pages;
6268 nr_all_pages += freesize;
6269
6270 /*
6271 * Set an approximate value for lowmem here, it will be adjusted
6272 * when the bootmem allocator frees pages into the buddy system.
6273 * And all highmem pages will be managed by the buddy system.
6274 */
6275 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
6276#ifdef CONFIG_NUMA
6277 zone->node = nid;
6278#endif
6279 zone->name = zone_names[j];
6280 zone->zone_pgdat = pgdat;
6281 spin_lock_init(&zone->lock);
6282 zone_seqlock_init(zone);
6283 zone_pcp_init(zone);
6284
6285 if (!size)
6286 continue;
6287
6288 set_pageblock_order();
6289 setup_usemap(pgdat, zone, zone_start_pfn, size);
6290 init_currently_empty_zone(zone, zone_start_pfn, size);
6291 memmap_init(size, nid, j, zone_start_pfn);
6292 }
6293}
6294
6295#ifdef CONFIG_FLAT_NODE_MEM_MAP
6296static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
6297{
6298 unsigned long __maybe_unused start = 0;
6299 unsigned long __maybe_unused offset = 0;
6300
6301 /* Skip empty nodes */
6302 if (!pgdat->node_spanned_pages)
6303 return;
6304
6305 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6306 offset = pgdat->node_start_pfn - start;
6307 /* ia64 gets its own node_mem_map, before this, without bootmem */
6308 if (!pgdat->node_mem_map) {
6309 unsigned long size, end;
6310 struct page *map;
6311
6312 /*
6313 * The zone's endpoints aren't required to be MAX_ORDER
6314 * aligned but the node_mem_map endpoints must be in order
6315 * for the buddy allocator to function correctly.
6316 */
6317 end = pgdat_end_pfn(pgdat);
6318 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6319 size = (end - start) * sizeof(struct page);
6320 map = memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
6321 pgdat->node_mem_map = map + offset;
6322 }
6323 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6324 __func__, pgdat->node_id, (unsigned long)pgdat,
6325 (unsigned long)pgdat->node_mem_map);
6326#ifndef CONFIG_NEED_MULTIPLE_NODES
6327 /*
6328 * With no DISCONTIG, the global mem_map is just set as node 0's
6329 */
6330 if (pgdat == NODE_DATA(0)) {
6331 mem_map = NODE_DATA(0)->node_mem_map;
6332#if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6333 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6334 mem_map -= offset;
6335#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6336 }
6337#endif
6338}
6339#else
6340static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
6341#endif /* CONFIG_FLAT_NODE_MEM_MAP */
6342
6343void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
6344 unsigned long node_start_pfn, unsigned long *zholes_size)
6345{
6346 pg_data_t *pgdat = NODE_DATA(nid);
6347 unsigned long start_pfn = 0;
6348 unsigned long end_pfn = 0;
6349
6350 /* pg_data_t should be reset to zero when it's allocated */
6351 WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
6352
6353 pgdat->node_id = nid;
6354 pgdat->node_start_pfn = node_start_pfn;
6355 pgdat->per_cpu_nodestats = NULL;
6356#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6357 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6358 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6359 (u64)start_pfn << PAGE_SHIFT,
6360 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6361#else
6362 start_pfn = node_start_pfn;
6363#endif
6364 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6365 zones_size, zholes_size);
6366
6367 alloc_node_mem_map(pgdat);
6368
6369#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6370 /*
6371 * We start only with one section of pages, more pages are added as
6372 * needed until the rest of deferred pages are initialized.
6373 */
6374 pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
6375 pgdat->node_spanned_pages);
6376 pgdat->first_deferred_pfn = ULONG_MAX;
6377#endif
6378 free_area_init_core(pgdat);
6379}
6380
6381#ifdef CONFIG_HAVE_MEMBLOCK
6382/*
6383 * Only struct pages that are backed by physical memory are zeroed and
6384 * initialized by going through __init_single_page(). But, there are some
6385 * struct pages which are reserved in memblock allocator and their fields
6386 * may be accessed (for example page_to_pfn() on some configuration accesses
6387 * flags). We must explicitly zero those struct pages.
6388 */
6389void __paginginit zero_resv_unavail(void)
6390{
6391 phys_addr_t start, end;
6392 unsigned long pfn;
6393 u64 i, pgcnt;
6394
6395 /*
6396 * Loop through ranges that are reserved, but do not have reported
6397 * physical memory backing.
6398 */
6399 pgcnt = 0;
6400 for_each_resv_unavail_range(i, &start, &end) {
6401 for (pfn = PFN_DOWN(start); pfn < PFN_UP(end); pfn++) {
6402 if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages)))
6403 continue;
6404 mm_zero_struct_page(pfn_to_page(pfn));
6405 pgcnt++;
6406 }
6407 }
6408
6409 /*
6410 * Struct pages that do not have backing memory. This could be because
6411 * firmware is using some of this memory, or for some other reasons.
6412 * Once memblock is changed so such behaviour is not allowed: i.e.
6413 * list of "reserved" memory must be a subset of list of "memory", then
6414 * this code can be removed.
6415 */
6416 if (pgcnt)
6417 pr_info("Reserved but unavailable: %lld pages", pgcnt);
6418}
6419#endif /* CONFIG_HAVE_MEMBLOCK */
6420
6421#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6422
6423#if MAX_NUMNODES > 1
6424/*
6425 * Figure out the number of possible node ids.
6426 */
6427void __init setup_nr_node_ids(void)
6428{
6429 unsigned int highest;
6430
6431 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
6432 nr_node_ids = highest + 1;
6433}
6434#endif
6435
6436/**
6437 * node_map_pfn_alignment - determine the maximum internode alignment
6438 *
6439 * This function should be called after node map is populated and sorted.
6440 * It calculates the maximum power of two alignment which can distinguish
6441 * all the nodes.
6442 *
6443 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6444 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6445 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6446 * shifted, 1GiB is enough and this function will indicate so.
6447 *
6448 * This is used to test whether pfn -> nid mapping of the chosen memory
6449 * model has fine enough granularity to avoid incorrect mapping for the
6450 * populated node map.
6451 *
6452 * Returns the determined alignment in pfn's. 0 if there is no alignment
6453 * requirement (single node).
6454 */
6455unsigned long __init node_map_pfn_alignment(void)
6456{
6457 unsigned long accl_mask = 0, last_end = 0;
6458 unsigned long start, end, mask;
6459 int last_nid = -1;
6460 int i, nid;
6461
6462 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
6463 if (!start || last_nid < 0 || last_nid == nid) {
6464 last_nid = nid;
6465 last_end = end;
6466 continue;
6467 }
6468
6469 /*
6470 * Start with a mask granular enough to pin-point to the
6471 * start pfn and tick off bits one-by-one until it becomes
6472 * too coarse to separate the current node from the last.
6473 */
6474 mask = ~((1 << __ffs(start)) - 1);
6475 while (mask && last_end <= (start & (mask << 1)))
6476 mask <<= 1;
6477
6478 /* accumulate all internode masks */
6479 accl_mask |= mask;
6480 }
6481
6482 /* convert mask to number of pages */
6483 return ~accl_mask + 1;
6484}
6485
6486/* Find the lowest pfn for a node */
6487static unsigned long __init find_min_pfn_for_node(int nid)
6488{
6489 unsigned long min_pfn = ULONG_MAX;
6490 unsigned long start_pfn;
6491 int i;
6492
6493 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
6494 min_pfn = min(min_pfn, start_pfn);
6495
6496 if (min_pfn == ULONG_MAX) {
6497 pr_warn("Could not find start_pfn for node %d\n", nid);
6498 return 0;
6499 }
6500
6501 return min_pfn;
6502}
6503
6504/**
6505 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6506 *
6507 * It returns the minimum PFN based on information provided via
6508 * memblock_set_node().
6509 */
6510unsigned long __init find_min_pfn_with_active_regions(void)
6511{
6512 return find_min_pfn_for_node(MAX_NUMNODES);
6513}
6514
6515/*
6516 * early_calculate_totalpages()
6517 * Sum pages in active regions for movable zone.
6518 * Populate N_MEMORY for calculating usable_nodes.
6519 */
6520static unsigned long __init early_calculate_totalpages(void)
6521{
6522 unsigned long totalpages = 0;
6523 unsigned long start_pfn, end_pfn;
6524 int i, nid;
6525
6526 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6527 unsigned long pages = end_pfn - start_pfn;
6528
6529 totalpages += pages;
6530 if (pages)
6531 node_set_state(nid, N_MEMORY);
6532 }
6533 return totalpages;
6534}
6535
6536/*
6537 * Find the PFN the Movable zone begins in each node. Kernel memory
6538 * is spread evenly between nodes as long as the nodes have enough
6539 * memory. When they don't, some nodes will have more kernelcore than
6540 * others
6541 */
6542static void __init find_zone_movable_pfns_for_nodes(void)
6543{
6544 int i, nid;
6545 unsigned long usable_startpfn;
6546 unsigned long kernelcore_node, kernelcore_remaining;
6547 /* save the state before borrow the nodemask */
6548 nodemask_t saved_node_state = node_states[N_MEMORY];
6549 unsigned long totalpages = early_calculate_totalpages();
6550 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6551 struct memblock_region *r;
6552
6553 /* Need to find movable_zone earlier when movable_node is specified. */
6554 find_usable_zone_for_movable();
6555
6556 /*
6557 * If movable_node is specified, ignore kernelcore and movablecore
6558 * options.
6559 */
6560 if (movable_node_is_enabled()) {
6561 for_each_memblock(memory, r) {
6562 if (!memblock_is_hotpluggable(r))
6563 continue;
6564
6565 nid = r->nid;
6566
6567 usable_startpfn = PFN_DOWN(r->base);
6568 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6569 min(usable_startpfn, zone_movable_pfn[nid]) :
6570 usable_startpfn;
6571 }
6572
6573 goto out2;
6574 }
6575
6576 /*
6577 * If kernelcore=mirror is specified, ignore movablecore option
6578 */
6579 if (mirrored_kernelcore) {
6580 bool mem_below_4gb_not_mirrored = false;
6581
6582 for_each_memblock(memory, r) {
6583 if (memblock_is_mirror(r))
6584 continue;
6585
6586 nid = r->nid;
6587
6588 usable_startpfn = memblock_region_memory_base_pfn(r);
6589
6590 if (usable_startpfn < 0x100000) {
6591 mem_below_4gb_not_mirrored = true;
6592 continue;
6593 }
6594
6595 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6596 min(usable_startpfn, zone_movable_pfn[nid]) :
6597 usable_startpfn;
6598 }
6599
6600 if (mem_below_4gb_not_mirrored)
6601 pr_warn("This configuration results in unmirrored kernel memory.");
6602
6603 goto out2;
6604 }
6605
6606 /*
6607 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
6608 * amount of necessary memory.
6609 */
6610 if (required_kernelcore_percent)
6611 required_kernelcore = (totalpages * 100 * required_kernelcore_percent) /
6612 10000UL;
6613 if (required_movablecore_percent)
6614 required_movablecore = (totalpages * 100 * required_movablecore_percent) /
6615 10000UL;
6616
6617 /*
6618 * If movablecore= was specified, calculate what size of
6619 * kernelcore that corresponds so that memory usable for
6620 * any allocation type is evenly spread. If both kernelcore
6621 * and movablecore are specified, then the value of kernelcore
6622 * will be used for required_kernelcore if it's greater than
6623 * what movablecore would have allowed.
6624 */
6625 if (required_movablecore) {
6626 unsigned long corepages;
6627
6628 /*
6629 * Round-up so that ZONE_MOVABLE is at least as large as what
6630 * was requested by the user
6631 */
6632 required_movablecore =
6633 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6634 required_movablecore = min(totalpages, required_movablecore);
6635 corepages = totalpages - required_movablecore;
6636
6637 required_kernelcore = max(required_kernelcore, corepages);
6638 }
6639
6640 /*
6641 * If kernelcore was not specified or kernelcore size is larger
6642 * than totalpages, there is no ZONE_MOVABLE.
6643 */
6644 if (!required_kernelcore || required_kernelcore >= totalpages)
6645 goto out;
6646
6647 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6648 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6649
6650restart:
6651 /* Spread kernelcore memory as evenly as possible throughout nodes */
6652 kernelcore_node = required_kernelcore / usable_nodes;
6653 for_each_node_state(nid, N_MEMORY) {
6654 unsigned long start_pfn, end_pfn;
6655
6656 /*
6657 * Recalculate kernelcore_node if the division per node
6658 * now exceeds what is necessary to satisfy the requested
6659 * amount of memory for the kernel
6660 */
6661 if (required_kernelcore < kernelcore_node)
6662 kernelcore_node = required_kernelcore / usable_nodes;
6663
6664 /*
6665 * As the map is walked, we track how much memory is usable
6666 * by the kernel using kernelcore_remaining. When it is
6667 * 0, the rest of the node is usable by ZONE_MOVABLE
6668 */
6669 kernelcore_remaining = kernelcore_node;
6670
6671 /* Go through each range of PFNs within this node */
6672 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6673 unsigned long size_pages;
6674
6675 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6676 if (start_pfn >= end_pfn)
6677 continue;
6678
6679 /* Account for what is only usable for kernelcore */
6680 if (start_pfn < usable_startpfn) {
6681 unsigned long kernel_pages;
6682 kernel_pages = min(end_pfn, usable_startpfn)
6683 - start_pfn;
6684
6685 kernelcore_remaining -= min(kernel_pages,
6686 kernelcore_remaining);
6687 required_kernelcore -= min(kernel_pages,
6688 required_kernelcore);
6689
6690 /* Continue if range is now fully accounted */
6691 if (end_pfn <= usable_startpfn) {
6692
6693 /*
6694 * Push zone_movable_pfn to the end so
6695 * that if we have to rebalance
6696 * kernelcore across nodes, we will
6697 * not double account here
6698 */
6699 zone_movable_pfn[nid] = end_pfn;
6700 continue;
6701 }
6702 start_pfn = usable_startpfn;
6703 }
6704
6705 /*
6706 * The usable PFN range for ZONE_MOVABLE is from
6707 * start_pfn->end_pfn. Calculate size_pages as the
6708 * number of pages used as kernelcore
6709 */
6710 size_pages = end_pfn - start_pfn;
6711 if (size_pages > kernelcore_remaining)
6712 size_pages = kernelcore_remaining;
6713 zone_movable_pfn[nid] = start_pfn + size_pages;
6714
6715 /*
6716 * Some kernelcore has been met, update counts and
6717 * break if the kernelcore for this node has been
6718 * satisfied
6719 */
6720 required_kernelcore -= min(required_kernelcore,
6721 size_pages);
6722 kernelcore_remaining -= size_pages;
6723 if (!kernelcore_remaining)
6724 break;
6725 }
6726 }
6727
6728 /*
6729 * If there is still required_kernelcore, we do another pass with one
6730 * less node in the count. This will push zone_movable_pfn[nid] further
6731 * along on the nodes that still have memory until kernelcore is
6732 * satisfied
6733 */
6734 usable_nodes--;
6735 if (usable_nodes && required_kernelcore > usable_nodes)
6736 goto restart;
6737
6738out2:
6739 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6740 for (nid = 0; nid < MAX_NUMNODES; nid++)
6741 zone_movable_pfn[nid] =
6742 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6743
6744out:
6745 /* restore the node_state */
6746 node_states[N_MEMORY] = saved_node_state;
6747}
6748
6749/* Any regular or high memory on that node ? */
6750static void check_for_memory(pg_data_t *pgdat, int nid)
6751{
6752 enum zone_type zone_type;
6753
6754 if (N_MEMORY == N_NORMAL_MEMORY)
6755 return;
6756
6757 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6758 struct zone *zone = &pgdat->node_zones[zone_type];
6759 if (populated_zone(zone)) {
6760 node_set_state(nid, N_HIGH_MEMORY);
6761 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6762 zone_type <= ZONE_NORMAL)
6763 node_set_state(nid, N_NORMAL_MEMORY);
6764 break;
6765 }
6766 }
6767}
6768
6769/**
6770 * free_area_init_nodes - Initialise all pg_data_t and zone data
6771 * @max_zone_pfn: an array of max PFNs for each zone
6772 *
6773 * This will call free_area_init_node() for each active node in the system.
6774 * Using the page ranges provided by memblock_set_node(), the size of each
6775 * zone in each node and their holes is calculated. If the maximum PFN
6776 * between two adjacent zones match, it is assumed that the zone is empty.
6777 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6778 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6779 * starts where the previous one ended. For example, ZONE_DMA32 starts
6780 * at arch_max_dma_pfn.
6781 */
6782void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6783{
6784 unsigned long start_pfn, end_pfn;
6785 int i, nid;
6786
6787 /* Record where the zone boundaries are */
6788 memset(arch_zone_lowest_possible_pfn, 0,
6789 sizeof(arch_zone_lowest_possible_pfn));
6790 memset(arch_zone_highest_possible_pfn, 0,
6791 sizeof(arch_zone_highest_possible_pfn));
6792
6793 start_pfn = find_min_pfn_with_active_regions();
6794
6795 for (i = 0; i < MAX_NR_ZONES; i++) {
6796 if (i == ZONE_MOVABLE)
6797 continue;
6798
6799 end_pfn = max(max_zone_pfn[i], start_pfn);
6800 arch_zone_lowest_possible_pfn[i] = start_pfn;
6801 arch_zone_highest_possible_pfn[i] = end_pfn;
6802
6803 start_pfn = end_pfn;
6804 }
6805
6806 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6807 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6808 find_zone_movable_pfns_for_nodes();
6809
6810 /* Print out the zone ranges */
6811 pr_info("Zone ranges:\n");
6812 for (i = 0; i < MAX_NR_ZONES; i++) {
6813 if (i == ZONE_MOVABLE)
6814 continue;
6815 pr_info(" %-8s ", zone_names[i]);
6816 if (arch_zone_lowest_possible_pfn[i] ==
6817 arch_zone_highest_possible_pfn[i])
6818 pr_cont("empty\n");
6819 else
6820 pr_cont("[mem %#018Lx-%#018Lx]\n",
6821 (u64)arch_zone_lowest_possible_pfn[i]
6822 << PAGE_SHIFT,
6823 ((u64)arch_zone_highest_possible_pfn[i]
6824 << PAGE_SHIFT) - 1);
6825 }
6826
6827 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6828 pr_info("Movable zone start for each node\n");
6829 for (i = 0; i < MAX_NUMNODES; i++) {
6830 if (zone_movable_pfn[i])
6831 pr_info(" Node %d: %#018Lx\n", i,
6832 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6833 }
6834
6835 /* Print out the early node map */
6836 pr_info("Early memory node ranges\n");
6837 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6838 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6839 (u64)start_pfn << PAGE_SHIFT,
6840 ((u64)end_pfn << PAGE_SHIFT) - 1);
6841
6842 /* Initialise every node */
6843 mminit_verify_pageflags_layout();
6844 setup_nr_node_ids();
6845 for_each_online_node(nid) {
6846 pg_data_t *pgdat = NODE_DATA(nid);
6847 free_area_init_node(nid, NULL,
6848 find_min_pfn_for_node(nid), NULL);
6849
6850 /* Any memory on that node */
6851 if (pgdat->node_present_pages)
6852 node_set_state(nid, N_MEMORY);
6853 check_for_memory(pgdat, nid);
6854 }
6855 zero_resv_unavail();
6856}
6857
6858static int __init cmdline_parse_core(char *p, unsigned long *core,
6859 unsigned long *percent)
6860{
6861 unsigned long long coremem;
6862 char *endptr;
6863
6864 if (!p)
6865 return -EINVAL;
6866
6867 /* Value may be a percentage of total memory, otherwise bytes */
6868 coremem = simple_strtoull(p, &endptr, 0);
6869 if (*endptr == '%') {
6870 /* Paranoid check for percent values greater than 100 */
6871 WARN_ON(coremem > 100);
6872
6873 *percent = coremem;
6874 } else {
6875 coremem = memparse(p, &p);
6876 /* Paranoid check that UL is enough for the coremem value */
6877 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6878
6879 *core = coremem >> PAGE_SHIFT;
6880 *percent = 0UL;
6881 }
6882 return 0;
6883}
6884
6885/*
6886 * kernelcore=size sets the amount of memory for use for allocations that
6887 * cannot be reclaimed or migrated.
6888 */
6889static int __init cmdline_parse_kernelcore(char *p)
6890{
6891 /* parse kernelcore=mirror */
6892 if (parse_option_str(p, "mirror")) {
6893 mirrored_kernelcore = true;
6894 return 0;
6895 }
6896
6897 return cmdline_parse_core(p, &required_kernelcore,
6898 &required_kernelcore_percent);
6899}
6900
6901/*
6902 * movablecore=size sets the amount of memory for use for allocations that
6903 * can be reclaimed or migrated.
6904 */
6905static int __init cmdline_parse_movablecore(char *p)
6906{
6907 return cmdline_parse_core(p, &required_movablecore,
6908 &required_movablecore_percent);
6909}
6910
6911early_param("kernelcore", cmdline_parse_kernelcore);
6912early_param("movablecore", cmdline_parse_movablecore);
6913
6914#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6915
6916void adjust_managed_page_count(struct page *page, long count)
6917{
6918 spin_lock(&managed_page_count_lock);
6919 page_zone(page)->managed_pages += count;
6920 totalram_pages += count;
6921#ifdef CONFIG_HIGHMEM
6922 if (PageHighMem(page))
6923 totalhigh_pages += count;
6924#endif
6925 spin_unlock(&managed_page_count_lock);
6926}
6927EXPORT_SYMBOL(adjust_managed_page_count);
6928
6929unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6930{
6931 void *pos;
6932 unsigned long pages = 0;
6933
6934 start = (void *)PAGE_ALIGN((unsigned long)start);
6935 end = (void *)((unsigned long)end & PAGE_MASK);
6936 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6937 if ((unsigned int)poison <= 0xFF)
6938 memset(pos, poison, PAGE_SIZE);
6939 free_reserved_page(virt_to_page(pos));
6940 }
6941
6942 if (pages && s)
6943 pr_info("Freeing %s memory: %ldK\n",
6944 s, pages << (PAGE_SHIFT - 10));
6945
6946 return pages;
6947}
6948EXPORT_SYMBOL(free_reserved_area);
6949
6950#ifdef CONFIG_HIGHMEM
6951void free_highmem_page(struct page *page)
6952{
6953 __free_reserved_page(page);
6954 totalram_pages++;
6955 page_zone(page)->managed_pages++;
6956 totalhigh_pages++;
6957}
6958#endif
6959
6960
6961void __init mem_init_print_info(const char *str)
6962{
6963 unsigned long physpages, codesize, datasize, rosize, bss_size;
6964 unsigned long init_code_size, init_data_size;
6965
6966 physpages = get_num_physpages();
6967 codesize = _etext - _stext;
6968 datasize = _edata - _sdata;
6969 rosize = __end_rodata - __start_rodata;
6970 bss_size = __bss_stop - __bss_start;
6971 init_data_size = __init_end - __init_begin;
6972 init_code_size = _einittext - _sinittext;
6973
6974 /*
6975 * Detect special cases and adjust section sizes accordingly:
6976 * 1) .init.* may be embedded into .data sections
6977 * 2) .init.text.* may be out of [__init_begin, __init_end],
6978 * please refer to arch/tile/kernel/vmlinux.lds.S.
6979 * 3) .rodata.* may be embedded into .text or .data sections.
6980 */
6981#define adj_init_size(start, end, size, pos, adj) \
6982 do { \
6983 if (start <= pos && pos < end && size > adj) \
6984 size -= adj; \
6985 } while (0)
6986
6987 adj_init_size(__init_begin, __init_end, init_data_size,
6988 _sinittext, init_code_size);
6989 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6990 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6991 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6992 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6993
6994#undef adj_init_size
6995
6996 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6997#ifdef CONFIG_HIGHMEM
6998 ", %luK highmem"
6999#endif
7000 "%s%s)\n",
7001 nr_free_pages() << (PAGE_SHIFT - 10),
7002 physpages << (PAGE_SHIFT - 10),
7003 codesize >> 10, datasize >> 10, rosize >> 10,
7004 (init_data_size + init_code_size) >> 10, bss_size >> 10,
7005 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
7006 totalcma_pages << (PAGE_SHIFT - 10),
7007#ifdef CONFIG_HIGHMEM
7008 totalhigh_pages << (PAGE_SHIFT - 10),
7009#endif
7010 str ? ", " : "", str ? str : "");
7011}
7012
7013/**
7014 * set_dma_reserve - set the specified number of pages reserved in the first zone
7015 * @new_dma_reserve: The number of pages to mark reserved
7016 *
7017 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7018 * In the DMA zone, a significant percentage may be consumed by kernel image
7019 * and other unfreeable allocations which can skew the watermarks badly. This
7020 * function may optionally be used to account for unfreeable pages in the
7021 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7022 * smaller per-cpu batchsize.
7023 */
7024void __init set_dma_reserve(unsigned long new_dma_reserve)
7025{
7026 dma_reserve = new_dma_reserve;
7027}
7028
7029void __init free_area_init(unsigned long *zones_size)
7030{
7031 free_area_init_node(0, zones_size,
7032 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
7033 zero_resv_unavail();
7034}
7035
7036static int page_alloc_cpu_dead(unsigned int cpu)
7037{
7038
7039 lru_add_drain_cpu(cpu);
7040 drain_pages(cpu);
7041
7042 /*
7043 * Spill the event counters of the dead processor
7044 * into the current processors event counters.
7045 * This artificially elevates the count of the current
7046 * processor.
7047 */
7048 vm_events_fold_cpu(cpu);
7049
7050 /*
7051 * Zero the differential counters of the dead processor
7052 * so that the vm statistics are consistent.
7053 *
7054 * This is only okay since the processor is dead and cannot
7055 * race with what we are doing.
7056 */
7057 cpu_vm_stats_fold(cpu);
7058 return 0;
7059}
7060
7061void __init page_alloc_init(void)
7062{
7063 int ret;
7064
7065 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD,
7066 "mm/page_alloc:dead", NULL,
7067 page_alloc_cpu_dead);
7068 WARN_ON(ret < 0);
7069}
7070
7071/*
7072 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7073 * or min_free_kbytes changes.
7074 */
7075static void calculate_totalreserve_pages(void)
7076{
7077 struct pglist_data *pgdat;
7078 unsigned long reserve_pages = 0;
7079 enum zone_type i, j;
7080
7081 for_each_online_pgdat(pgdat) {
7082
7083 pgdat->totalreserve_pages = 0;
7084
7085 for (i = 0; i < MAX_NR_ZONES; i++) {
7086 struct zone *zone = pgdat->node_zones + i;
7087 long max = 0;
7088
7089 /* Find valid and maximum lowmem_reserve in the zone */
7090 for (j = i; j < MAX_NR_ZONES; j++) {
7091 if (zone->lowmem_reserve[j] > max)
7092 max = zone->lowmem_reserve[j];
7093 }
7094
7095 /* we treat the high watermark as reserved pages. */
7096 max += high_wmark_pages(zone);
7097
7098 if (max > zone->managed_pages)
7099 max = zone->managed_pages;
7100
7101 pgdat->totalreserve_pages += max;
7102
7103 reserve_pages += max;
7104 }
7105 }
7106 totalreserve_pages = reserve_pages;
7107}
7108
7109/*
7110 * setup_per_zone_lowmem_reserve - called whenever
7111 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7112 * has a correct pages reserved value, so an adequate number of
7113 * pages are left in the zone after a successful __alloc_pages().
7114 */
7115static void setup_per_zone_lowmem_reserve(void)
7116{
7117 struct pglist_data *pgdat;
7118 enum zone_type j, idx;
7119
7120 for_each_online_pgdat(pgdat) {
7121 for (j = 0; j < MAX_NR_ZONES; j++) {
7122 struct zone *zone = pgdat->node_zones + j;
7123 unsigned long managed_pages = zone->managed_pages;
7124
7125 zone->lowmem_reserve[j] = 0;
7126
7127 idx = j;
7128 while (idx) {
7129 struct zone *lower_zone;
7130
7131 idx--;
7132 lower_zone = pgdat->node_zones + idx;
7133
7134 if (sysctl_lowmem_reserve_ratio[idx] < 1) {
7135 sysctl_lowmem_reserve_ratio[idx] = 0;
7136 lower_zone->lowmem_reserve[j] = 0;
7137 } else {
7138 lower_zone->lowmem_reserve[j] =
7139 managed_pages / sysctl_lowmem_reserve_ratio[idx];
7140 }
7141 managed_pages += lower_zone->managed_pages;
7142 }
7143 }
7144 }
7145
7146 /* update totalreserve_pages */
7147 calculate_totalreserve_pages();
7148}
7149
7150static void __setup_per_zone_wmarks(void)
7151{
7152 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
7153 unsigned long lowmem_pages = 0;
7154 struct zone *zone;
7155 unsigned long flags;
7156
7157 /* Calculate total number of !ZONE_HIGHMEM pages */
7158 for_each_zone(zone) {
7159 if (!is_highmem(zone))
7160 lowmem_pages += zone->managed_pages;
7161 }
7162
7163 for_each_zone(zone) {
7164 u64 tmp;
7165
7166 spin_lock_irqsave(&zone->lock, flags);
7167 tmp = (u64)pages_min * zone->managed_pages;
7168 do_div(tmp, lowmem_pages);
7169 if (is_highmem(zone)) {
7170 /*
7171 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7172 * need highmem pages, so cap pages_min to a small
7173 * value here.
7174 *
7175 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7176 * deltas control asynch page reclaim, and so should
7177 * not be capped for highmem.
7178 */
7179 unsigned long min_pages;
7180
7181 min_pages = zone->managed_pages / 1024;
7182 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
7183 zone->watermark[WMARK_MIN] = min_pages;
7184 } else {
7185 /*
7186 * If it's a lowmem zone, reserve a number of pages
7187 * proportionate to the zone's size.
7188 */
7189 zone->watermark[WMARK_MIN] = tmp;
7190 }
7191
7192 /*
7193 * Set the kswapd watermarks distance according to the
7194 * scale factor in proportion to available memory, but
7195 * ensure a minimum size on small systems.
7196 */
7197 tmp = max_t(u64, tmp >> 2,
7198 mult_frac(zone->managed_pages,
7199 watermark_scale_factor, 10000));
7200
7201 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
7202 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
7203
7204 spin_unlock_irqrestore(&zone->lock, flags);
7205 }
7206
7207 /* update totalreserve_pages */
7208 calculate_totalreserve_pages();
7209}
7210
7211/**
7212 * setup_per_zone_wmarks - called when min_free_kbytes changes
7213 * or when memory is hot-{added|removed}
7214 *
7215 * Ensures that the watermark[min,low,high] values for each zone are set
7216 * correctly with respect to min_free_kbytes.
7217 */
7218void setup_per_zone_wmarks(void)
7219{
7220 static DEFINE_SPINLOCK(lock);
7221
7222 spin_lock(&lock);
7223 __setup_per_zone_wmarks();
7224 spin_unlock(&lock);
7225}
7226
7227/*
7228 * Initialise min_free_kbytes.
7229 *
7230 * For small machines we want it small (128k min). For large machines
7231 * we want it large (64MB max). But it is not linear, because network
7232 * bandwidth does not increase linearly with machine size. We use
7233 *
7234 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7235 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7236 *
7237 * which yields
7238 *
7239 * 16MB: 512k
7240 * 32MB: 724k
7241 * 64MB: 1024k
7242 * 128MB: 1448k
7243 * 256MB: 2048k
7244 * 512MB: 2896k
7245 * 1024MB: 4096k
7246 * 2048MB: 5792k
7247 * 4096MB: 8192k
7248 * 8192MB: 11584k
7249 * 16384MB: 16384k
7250 */
7251int __meminit init_per_zone_wmark_min(void)
7252{
7253 unsigned long lowmem_kbytes;
7254 int new_min_free_kbytes;
7255
7256 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
7257 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
7258
7259 if (new_min_free_kbytes > user_min_free_kbytes) {
7260 min_free_kbytes = new_min_free_kbytes;
7261 if (min_free_kbytes < 128)
7262 min_free_kbytes = 128;
7263 if (min_free_kbytes > 65536)
7264 min_free_kbytes = 65536;
7265 } else {
7266 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7267 new_min_free_kbytes, user_min_free_kbytes);
7268 }
7269 setup_per_zone_wmarks();
7270 refresh_zone_stat_thresholds();
7271 setup_per_zone_lowmem_reserve();
7272
7273#ifdef CONFIG_NUMA
7274 setup_min_unmapped_ratio();
7275 setup_min_slab_ratio();
7276#endif
7277
7278 return 0;
7279}
7280core_initcall(init_per_zone_wmark_min)
7281
7282/*
7283 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7284 * that we can call two helper functions whenever min_free_kbytes
7285 * changes.
7286 */
7287int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
7288 void __user *buffer, size_t *length, loff_t *ppos)
7289{
7290 int rc;
7291
7292 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7293 if (rc)
7294 return rc;
7295
7296 if (write) {
7297 user_min_free_kbytes = min_free_kbytes;
7298 setup_per_zone_wmarks();
7299 }
7300 return 0;
7301}
7302
7303int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
7304 void __user *buffer, size_t *length, loff_t *ppos)
7305{
7306 int rc;
7307
7308 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7309 if (rc)
7310 return rc;
7311
7312 if (write)
7313 setup_per_zone_wmarks();
7314
7315 return 0;
7316}
7317
7318#ifdef CONFIG_NUMA
7319static void setup_min_unmapped_ratio(void)
7320{
7321 pg_data_t *pgdat;
7322 struct zone *zone;
7323
7324 for_each_online_pgdat(pgdat)
7325 pgdat->min_unmapped_pages = 0;
7326
7327 for_each_zone(zone)
7328 zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
7329 sysctl_min_unmapped_ratio) / 100;
7330}
7331
7332
7333int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
7334 void __user *buffer, size_t *length, loff_t *ppos)
7335{
7336 int rc;
7337
7338 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7339 if (rc)
7340 return rc;
7341
7342 setup_min_unmapped_ratio();
7343
7344 return 0;
7345}
7346
7347static void setup_min_slab_ratio(void)
7348{
7349 pg_data_t *pgdat;
7350 struct zone *zone;
7351
7352 for_each_online_pgdat(pgdat)
7353 pgdat->min_slab_pages = 0;
7354
7355 for_each_zone(zone)
7356 zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
7357 sysctl_min_slab_ratio) / 100;
7358}
7359
7360int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
7361 void __user *buffer, size_t *length, loff_t *ppos)
7362{
7363 int rc;
7364
7365 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7366 if (rc)
7367 return rc;
7368
7369 setup_min_slab_ratio();
7370
7371 return 0;
7372}
7373#endif
7374
7375/*
7376 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7377 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7378 * whenever sysctl_lowmem_reserve_ratio changes.
7379 *
7380 * The reserve ratio obviously has absolutely no relation with the
7381 * minimum watermarks. The lowmem reserve ratio can only make sense
7382 * if in function of the boot time zone sizes.
7383 */
7384int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
7385 void __user *buffer, size_t *length, loff_t *ppos)
7386{
7387 proc_dointvec_minmax(table, write, buffer, length, ppos);
7388 setup_per_zone_lowmem_reserve();
7389 return 0;
7390}
7391
7392/*
7393 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7394 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7395 * pagelist can have before it gets flushed back to buddy allocator.
7396 */
7397int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
7398 void __user *buffer, size_t *length, loff_t *ppos)
7399{
7400 struct zone *zone;
7401 int old_percpu_pagelist_fraction;
7402 int ret;
7403
7404 mutex_lock(&pcp_batch_high_lock);
7405 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
7406
7407 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
7408 if (!write || ret < 0)
7409 goto out;
7410
7411 /* Sanity checking to avoid pcp imbalance */
7412 if (percpu_pagelist_fraction &&
7413 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
7414 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
7415 ret = -EINVAL;
7416 goto out;
7417 }
7418
7419 /* No change? */
7420 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
7421 goto out;
7422
7423 for_each_populated_zone(zone) {
7424 unsigned int cpu;
7425
7426 for_each_possible_cpu(cpu)
7427 pageset_set_high_and_batch(zone,
7428 per_cpu_ptr(zone->pageset, cpu));
7429 }
7430out:
7431 mutex_unlock(&pcp_batch_high_lock);
7432 return ret;
7433}
7434
7435#ifdef CONFIG_NUMA
7436int hashdist = HASHDIST_DEFAULT;
7437
7438static int __init set_hashdist(char *str)
7439{
7440 if (!str)
7441 return 0;
7442 hashdist = simple_strtoul(str, &str, 0);
7443 return 1;
7444}
7445__setup("hashdist=", set_hashdist);
7446#endif
7447
7448#ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7449/*
7450 * Returns the number of pages that arch has reserved but
7451 * is not known to alloc_large_system_hash().
7452 */
7453static unsigned long __init arch_reserved_kernel_pages(void)
7454{
7455 return 0;
7456}
7457#endif
7458
7459/*
7460 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7461 * machines. As memory size is increased the scale is also increased but at
7462 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7463 * quadruples the scale is increased by one, which means the size of hash table
7464 * only doubles, instead of quadrupling as well.
7465 * Because 32-bit systems cannot have large physical memory, where this scaling
7466 * makes sense, it is disabled on such platforms.
7467 */
7468#if __BITS_PER_LONG > 32
7469#define ADAPT_SCALE_BASE (64ul << 30)
7470#define ADAPT_SCALE_SHIFT 2
7471#define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7472#endif
7473
7474/*
7475 * allocate a large system hash table from bootmem
7476 * - it is assumed that the hash table must contain an exact power-of-2
7477 * quantity of entries
7478 * - limit is the number of hash buckets, not the total allocation size
7479 */
7480void *__init alloc_large_system_hash(const char *tablename,
7481 unsigned long bucketsize,
7482 unsigned long numentries,
7483 int scale,
7484 int flags,
7485 unsigned int *_hash_shift,
7486 unsigned int *_hash_mask,
7487 unsigned long low_limit,
7488 unsigned long high_limit)
7489{
7490 unsigned long long max = high_limit;
7491 unsigned long log2qty, size;
7492 void *table = NULL;
7493 gfp_t gfp_flags;
7494
7495 /* allow the kernel cmdline to have a say */
7496 if (!numentries) {
7497 /* round applicable memory size up to nearest megabyte */
7498 numentries = nr_kernel_pages;
7499 numentries -= arch_reserved_kernel_pages();
7500
7501 /* It isn't necessary when PAGE_SIZE >= 1MB */
7502 if (PAGE_SHIFT < 20)
7503 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
7504
7505#if __BITS_PER_LONG > 32
7506 if (!high_limit) {
7507 unsigned long adapt;
7508
7509 for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries;
7510 adapt <<= ADAPT_SCALE_SHIFT)
7511 scale++;
7512 }
7513#endif
7514
7515 /* limit to 1 bucket per 2^scale bytes of low memory */
7516 if (scale > PAGE_SHIFT)
7517 numentries >>= (scale - PAGE_SHIFT);
7518 else
7519 numentries <<= (PAGE_SHIFT - scale);
7520
7521 /* Make sure we've got at least a 0-order allocation.. */
7522 if (unlikely(flags & HASH_SMALL)) {
7523 /* Makes no sense without HASH_EARLY */
7524 WARN_ON(!(flags & HASH_EARLY));
7525 if (!(numentries >> *_hash_shift)) {
7526 numentries = 1UL << *_hash_shift;
7527 BUG_ON(!numentries);
7528 }
7529 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
7530 numentries = PAGE_SIZE / bucketsize;
7531 }
7532 numentries = roundup_pow_of_two(numentries);
7533
7534 /* limit allocation size to 1/16 total memory by default */
7535 if (max == 0) {
7536 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
7537 do_div(max, bucketsize);
7538 }
7539 max = min(max, 0x80000000ULL);
7540
7541 if (numentries < low_limit)
7542 numentries = low_limit;
7543 if (numentries > max)
7544 numentries = max;
7545
7546 log2qty = ilog2(numentries);
7547
7548 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
7549 do {
7550 size = bucketsize << log2qty;
7551 if (flags & HASH_EARLY) {
7552 if (flags & HASH_ZERO)
7553 table = memblock_virt_alloc_nopanic(size, 0);
7554 else
7555 table = memblock_virt_alloc_raw(size, 0);
7556 } else if (hashdist) {
7557 table = __vmalloc(size, gfp_flags, PAGE_KERNEL);
7558 } else {
7559 /*
7560 * If bucketsize is not a power-of-two, we may free
7561 * some pages at the end of hash table which
7562 * alloc_pages_exact() automatically does
7563 */
7564 if (get_order(size) < MAX_ORDER) {
7565 table = alloc_pages_exact(size, gfp_flags);
7566 kmemleak_alloc(table, size, 1, gfp_flags);
7567 }
7568 }
7569 } while (!table && size > PAGE_SIZE && --log2qty);
7570
7571 if (!table)
7572 panic("Failed to allocate %s hash table\n", tablename);
7573
7574 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7575 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7576
7577 if (_hash_shift)
7578 *_hash_shift = log2qty;
7579 if (_hash_mask)
7580 *_hash_mask = (1 << log2qty) - 1;
7581
7582 return table;
7583}
7584
7585/*
7586 * This function checks whether pageblock includes unmovable pages or not.
7587 * If @count is not zero, it is okay to include less @count unmovable pages
7588 *
7589 * PageLRU check without isolation or lru_lock could race so that
7590 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7591 * check without lock_page also may miss some movable non-lru pages at
7592 * race condition. So you can't expect this function should be exact.
7593 */
7594bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7595 int migratetype,
7596 bool skip_hwpoisoned_pages)
7597{
7598 unsigned long pfn, iter, found;
7599
7600 /*
7601 * TODO we could make this much more efficient by not checking every
7602 * page in the range if we know all of them are in MOVABLE_ZONE and
7603 * that the movable zone guarantees that pages are migratable but
7604 * the later is not the case right now unfortunatelly. E.g. movablecore
7605 * can still lead to having bootmem allocations in zone_movable.
7606 */
7607
7608 /*
7609 * CMA allocations (alloc_contig_range) really need to mark isolate
7610 * CMA pageblocks even when they are not movable in fact so consider
7611 * them movable here.
7612 */
7613 if (is_migrate_cma(migratetype) &&
7614 is_migrate_cma(get_pageblock_migratetype(page)))
7615 return false;
7616
7617 pfn = page_to_pfn(page);
7618 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7619 unsigned long check = pfn + iter;
7620
7621 if (!pfn_valid_within(check))
7622 continue;
7623
7624 page = pfn_to_page(check);
7625
7626 if (PageReserved(page))
7627 goto unmovable;
7628
7629 /*
7630 * Hugepages are not in LRU lists, but they're movable.
7631 * We need not scan over tail pages bacause we don't
7632 * handle each tail page individually in migration.
7633 */
7634 if (PageHuge(page)) {
7635 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7636 continue;
7637 }
7638
7639 /*
7640 * We can't use page_count without pin a page
7641 * because another CPU can free compound page.
7642 * This check already skips compound tails of THP
7643 * because their page->_refcount is zero at all time.
7644 */
7645 if (!page_ref_count(page)) {
7646 if (PageBuddy(page))
7647 iter += (1 << page_order(page)) - 1;
7648 continue;
7649 }
7650
7651 /*
7652 * The HWPoisoned page may be not in buddy system, and
7653 * page_count() is not 0.
7654 */
7655 if (skip_hwpoisoned_pages && PageHWPoison(page))
7656 continue;
7657
7658 if (__PageMovable(page))
7659 continue;
7660
7661 if (!PageLRU(page))
7662 found++;
7663 /*
7664 * If there are RECLAIMABLE pages, we need to check
7665 * it. But now, memory offline itself doesn't call
7666 * shrink_node_slabs() and it still to be fixed.
7667 */
7668 /*
7669 * If the page is not RAM, page_count()should be 0.
7670 * we don't need more check. This is an _used_ not-movable page.
7671 *
7672 * The problematic thing here is PG_reserved pages. PG_reserved
7673 * is set to both of a memory hole page and a _used_ kernel
7674 * page at boot.
7675 */
7676 if (found > count)
7677 goto unmovable;
7678 }
7679 return false;
7680unmovable:
7681 WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE);
7682 return true;
7683}
7684
7685bool is_pageblock_removable_nolock(struct page *page)
7686{
7687 struct zone *zone;
7688 unsigned long pfn;
7689
7690 /*
7691 * We have to be careful here because we are iterating over memory
7692 * sections which are not zone aware so we might end up outside of
7693 * the zone but still within the section.
7694 * We have to take care about the node as well. If the node is offline
7695 * its NODE_DATA will be NULL - see page_zone.
7696 */
7697 if (!node_online(page_to_nid(page)))
7698 return false;
7699
7700 zone = page_zone(page);
7701 pfn = page_to_pfn(page);
7702 if (!zone_spans_pfn(zone, pfn))
7703 return false;
7704
7705 return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE, true);
7706}
7707
7708#if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7709
7710static unsigned long pfn_max_align_down(unsigned long pfn)
7711{
7712 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7713 pageblock_nr_pages) - 1);
7714}
7715
7716static unsigned long pfn_max_align_up(unsigned long pfn)
7717{
7718 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7719 pageblock_nr_pages));
7720}
7721
7722/* [start, end) must belong to a single zone. */
7723static int __alloc_contig_migrate_range(struct compact_control *cc,
7724 unsigned long start, unsigned long end)
7725{
7726 /* This function is based on compact_zone() from compaction.c. */
7727 unsigned long nr_reclaimed;
7728 unsigned long pfn = start;
7729 unsigned int tries = 0;
7730 int ret = 0;
7731
7732 migrate_prep();
7733
7734 while (pfn < end || !list_empty(&cc->migratepages)) {
7735 if (fatal_signal_pending(current)) {
7736 ret = -EINTR;
7737 break;
7738 }
7739
7740 if (list_empty(&cc->migratepages)) {
7741 cc->nr_migratepages = 0;
7742 pfn = isolate_migratepages_range(cc, pfn, end);
7743 if (!pfn) {
7744 ret = -EINTR;
7745 break;
7746 }
7747 tries = 0;
7748 } else if (++tries == 5) {
7749 ret = ret < 0 ? ret : -EBUSY;
7750 break;
7751 }
7752
7753 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7754 &cc->migratepages);
7755 cc->nr_migratepages -= nr_reclaimed;
7756
7757 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7758 NULL, 0, cc->mode, MR_CONTIG_RANGE);
7759 }
7760 if (ret < 0) {
7761 putback_movable_pages(&cc->migratepages);
7762 return ret;
7763 }
7764 return 0;
7765}
7766
7767/**
7768 * alloc_contig_range() -- tries to allocate given range of pages
7769 * @start: start PFN to allocate
7770 * @end: one-past-the-last PFN to allocate
7771 * @migratetype: migratetype of the underlaying pageblocks (either
7772 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7773 * in range must have the same migratetype and it must
7774 * be either of the two.
7775 * @gfp_mask: GFP mask to use during compaction
7776 *
7777 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7778 * aligned. The PFN range must belong to a single zone.
7779 *
7780 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
7781 * pageblocks in the range. Once isolated, the pageblocks should not
7782 * be modified by others.
7783 *
7784 * Returns zero on success or negative error code. On success all
7785 * pages which PFN is in [start, end) are allocated for the caller and
7786 * need to be freed with free_contig_range().
7787 */
7788int alloc_contig_range(unsigned long start, unsigned long end,
7789 unsigned migratetype, gfp_t gfp_mask)
7790{
7791 unsigned long outer_start, outer_end;
7792 unsigned int order;
7793 int ret = 0;
7794
7795 struct compact_control cc = {
7796 .nr_migratepages = 0,
7797 .order = -1,
7798 .zone = page_zone(pfn_to_page(start)),
7799 .mode = MIGRATE_SYNC,
7800 .ignore_skip_hint = true,
7801 .no_set_skip_hint = true,
7802 .gfp_mask = current_gfp_context(gfp_mask),
7803 };
7804 INIT_LIST_HEAD(&cc.migratepages);
7805
7806 /*
7807 * What we do here is we mark all pageblocks in range as
7808 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7809 * have different sizes, and due to the way page allocator
7810 * work, we align the range to biggest of the two pages so
7811 * that page allocator won't try to merge buddies from
7812 * different pageblocks and change MIGRATE_ISOLATE to some
7813 * other migration type.
7814 *
7815 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7816 * migrate the pages from an unaligned range (ie. pages that
7817 * we are interested in). This will put all the pages in
7818 * range back to page allocator as MIGRATE_ISOLATE.
7819 *
7820 * When this is done, we take the pages in range from page
7821 * allocator removing them from the buddy system. This way
7822 * page allocator will never consider using them.
7823 *
7824 * This lets us mark the pageblocks back as
7825 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7826 * aligned range but not in the unaligned, original range are
7827 * put back to page allocator so that buddy can use them.
7828 */
7829
7830 ret = start_isolate_page_range(pfn_max_align_down(start),
7831 pfn_max_align_up(end), migratetype,
7832 false);
7833 if (ret)
7834 return ret;
7835
7836 /*
7837 * In case of -EBUSY, we'd like to know which page causes problem.
7838 * So, just fall through. test_pages_isolated() has a tracepoint
7839 * which will report the busy page.
7840 *
7841 * It is possible that busy pages could become available before
7842 * the call to test_pages_isolated, and the range will actually be
7843 * allocated. So, if we fall through be sure to clear ret so that
7844 * -EBUSY is not accidentally used or returned to caller.
7845 */
7846 ret = __alloc_contig_migrate_range(&cc, start, end);
7847 if (ret && ret != -EBUSY)
7848 goto done;
7849 ret =0;
7850
7851 /*
7852 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7853 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7854 * more, all pages in [start, end) are free in page allocator.
7855 * What we are going to do is to allocate all pages from
7856 * [start, end) (that is remove them from page allocator).
7857 *
7858 * The only problem is that pages at the beginning and at the
7859 * end of interesting range may be not aligned with pages that
7860 * page allocator holds, ie. they can be part of higher order
7861 * pages. Because of this, we reserve the bigger range and
7862 * once this is done free the pages we are not interested in.
7863 *
7864 * We don't have to hold zone->lock here because the pages are
7865 * isolated thus they won't get removed from buddy.
7866 */
7867
7868 lru_add_drain_all();
7869 drain_all_pages(cc.zone);
7870
7871 order = 0;
7872 outer_start = start;
7873 while (!PageBuddy(pfn_to_page(outer_start))) {
7874 if (++order >= MAX_ORDER) {
7875 outer_start = start;
7876 break;
7877 }
7878 outer_start &= ~0UL << order;
7879 }
7880
7881 if (outer_start != start) {
7882 order = page_order(pfn_to_page(outer_start));
7883
7884 /*
7885 * outer_start page could be small order buddy page and
7886 * it doesn't include start page. Adjust outer_start
7887 * in this case to report failed page properly
7888 * on tracepoint in test_pages_isolated()
7889 */
7890 if (outer_start + (1UL << order) <= start)
7891 outer_start = start;
7892 }
7893
7894 /* Make sure the range is really isolated. */
7895 if (test_pages_isolated(outer_start, end, false)) {
7896 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
7897 __func__, outer_start, end);
7898 ret = -EBUSY;
7899 goto done;
7900 }
7901
7902 /* Grab isolated pages from freelists. */
7903 outer_end = isolate_freepages_range(&cc, outer_start, end);
7904 if (!outer_end) {
7905 ret = -EBUSY;
7906 goto done;
7907 }
7908
7909 /* Free head and tail (if any) */
7910 if (start != outer_start)
7911 free_contig_range(outer_start, start - outer_start);
7912 if (end != outer_end)
7913 free_contig_range(end, outer_end - end);
7914
7915done:
7916 undo_isolate_page_range(pfn_max_align_down(start),
7917 pfn_max_align_up(end), migratetype);
7918 return ret;
7919}
7920
7921void free_contig_range(unsigned long pfn, unsigned nr_pages)
7922{
7923 unsigned int count = 0;
7924
7925 for (; nr_pages--; pfn++) {
7926 struct page *page = pfn_to_page(pfn);
7927
7928 count += page_count(page) != 1;
7929 __free_page(page);
7930 }
7931 WARN(count != 0, "%d pages are still in use!\n", count);
7932}
7933#endif
7934
7935#ifdef CONFIG_MEMORY_HOTPLUG
7936/*
7937 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7938 * page high values need to be recalulated.
7939 */
7940void __meminit zone_pcp_update(struct zone *zone)
7941{
7942 unsigned cpu;
7943 mutex_lock(&pcp_batch_high_lock);
7944 for_each_possible_cpu(cpu)
7945 pageset_set_high_and_batch(zone,
7946 per_cpu_ptr(zone->pageset, cpu));
7947 mutex_unlock(&pcp_batch_high_lock);
7948}
7949#endif
7950
7951void zone_pcp_reset(struct zone *zone)
7952{
7953 unsigned long flags;
7954 int cpu;
7955 struct per_cpu_pageset *pset;
7956
7957 /* avoid races with drain_pages() */
7958 local_irq_save(flags);
7959 if (zone->pageset != &boot_pageset) {
7960 for_each_online_cpu(cpu) {
7961 pset = per_cpu_ptr(zone->pageset, cpu);
7962 drain_zonestat(zone, pset);
7963 }
7964 free_percpu(zone->pageset);
7965 zone->pageset = &boot_pageset;
7966 }
7967 local_irq_restore(flags);
7968}
7969
7970#ifdef CONFIG_MEMORY_HOTREMOVE
7971/*
7972 * All pages in the range must be in a single zone and isolated
7973 * before calling this.
7974 */
7975void
7976__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7977{
7978 struct page *page;
7979 struct zone *zone;
7980 unsigned int order, i;
7981 unsigned long pfn;
7982 unsigned long flags;
7983 /* find the first valid pfn */
7984 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7985 if (pfn_valid(pfn))
7986 break;
7987 if (pfn == end_pfn)
7988 return;
7989 offline_mem_sections(pfn, end_pfn);
7990 zone = page_zone(pfn_to_page(pfn));
7991 spin_lock_irqsave(&zone->lock, flags);
7992 pfn = start_pfn;
7993 while (pfn < end_pfn) {
7994 if (!pfn_valid(pfn)) {
7995 pfn++;
7996 continue;
7997 }
7998 page = pfn_to_page(pfn);
7999 /*
8000 * The HWPoisoned page may be not in buddy system, and
8001 * page_count() is not 0.
8002 */
8003 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
8004 pfn++;
8005 SetPageReserved(page);
8006 continue;
8007 }
8008
8009 BUG_ON(page_count(page));
8010 BUG_ON(!PageBuddy(page));
8011 order = page_order(page);
8012#ifdef CONFIG_DEBUG_VM
8013 pr_info("remove from free list %lx %d %lx\n",
8014 pfn, 1 << order, end_pfn);
8015#endif
8016 list_del(&page->lru);
8017 rmv_page_order(page);
8018 zone->free_area[order].nr_free--;
8019 for (i = 0; i < (1 << order); i++)
8020 SetPageReserved((page+i));
8021 pfn += (1 << order);
8022 }
8023 spin_unlock_irqrestore(&zone->lock, flags);
8024}
8025#endif
8026
8027bool is_free_buddy_page(struct page *page)
8028{
8029 struct zone *zone = page_zone(page);
8030 unsigned long pfn = page_to_pfn(page);
8031 unsigned long flags;
8032 unsigned int order;
8033
8034 spin_lock_irqsave(&zone->lock, flags);
8035 for (order = 0; order < MAX_ORDER; order++) {
8036 struct page *page_head = page - (pfn & ((1 << order) - 1));
8037
8038 if (PageBuddy(page_head) && page_order(page_head) >= order)
8039 break;
8040 }
8041 spin_unlock_irqrestore(&zone->lock, flags);
8042
8043 return order < MAX_ORDER;
8044}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/mm/page_alloc.c
4 *
5 * Manages the free list, the system allocates free pages here.
6 * Note that kmalloc() lives in slab.c
7 *
8 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
9 * Swap reorganised 29.12.95, Stephen Tweedie
10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
11 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
12 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
13 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
14 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
15 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
16 */
17
18#include <linux/stddef.h>
19#include <linux/mm.h>
20#include <linux/highmem.h>
21#include <linux/swap.h>
22#include <linux/interrupt.h>
23#include <linux/pagemap.h>
24#include <linux/jiffies.h>
25#include <linux/memblock.h>
26#include <linux/compiler.h>
27#include <linux/kernel.h>
28#include <linux/kasan.h>
29#include <linux/module.h>
30#include <linux/suspend.h>
31#include <linux/pagevec.h>
32#include <linux/blkdev.h>
33#include <linux/slab.h>
34#include <linux/ratelimit.h>
35#include <linux/oom.h>
36#include <linux/topology.h>
37#include <linux/sysctl.h>
38#include <linux/cpu.h>
39#include <linux/cpuset.h>
40#include <linux/memory_hotplug.h>
41#include <linux/nodemask.h>
42#include <linux/vmalloc.h>
43#include <linux/vmstat.h>
44#include <linux/mempolicy.h>
45#include <linux/memremap.h>
46#include <linux/stop_machine.h>
47#include <linux/random.h>
48#include <linux/sort.h>
49#include <linux/pfn.h>
50#include <linux/backing-dev.h>
51#include <linux/fault-inject.h>
52#include <linux/page-isolation.h>
53#include <linux/debugobjects.h>
54#include <linux/kmemleak.h>
55#include <linux/compaction.h>
56#include <trace/events/kmem.h>
57#include <trace/events/oom.h>
58#include <linux/prefetch.h>
59#include <linux/mm_inline.h>
60#include <linux/migrate.h>
61#include <linux/hugetlb.h>
62#include <linux/sched/rt.h>
63#include <linux/sched/mm.h>
64#include <linux/page_owner.h>
65#include <linux/kthread.h>
66#include <linux/memcontrol.h>
67#include <linux/ftrace.h>
68#include <linux/lockdep.h>
69#include <linux/nmi.h>
70#include <linux/psi.h>
71#include <linux/padata.h>
72#include <linux/khugepaged.h>
73
74#include <asm/sections.h>
75#include <asm/tlbflush.h>
76#include <asm/div64.h>
77#include "internal.h"
78#include "shuffle.h"
79#include "page_reporting.h"
80
81/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
82static DEFINE_MUTEX(pcp_batch_high_lock);
83#define MIN_PERCPU_PAGELIST_FRACTION (8)
84
85#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
86DEFINE_PER_CPU(int, numa_node);
87EXPORT_PER_CPU_SYMBOL(numa_node);
88#endif
89
90DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
91
92#ifdef CONFIG_HAVE_MEMORYLESS_NODES
93/*
94 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
95 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
96 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
97 * defined in <linux/topology.h>.
98 */
99DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
100EXPORT_PER_CPU_SYMBOL(_numa_mem_);
101#endif
102
103/* work_structs for global per-cpu drains */
104struct pcpu_drain {
105 struct zone *zone;
106 struct work_struct work;
107};
108static DEFINE_MUTEX(pcpu_drain_mutex);
109static DEFINE_PER_CPU(struct pcpu_drain, pcpu_drain);
110
111#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
112volatile unsigned long latent_entropy __latent_entropy;
113EXPORT_SYMBOL(latent_entropy);
114#endif
115
116/*
117 * Array of node states.
118 */
119nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
120 [N_POSSIBLE] = NODE_MASK_ALL,
121 [N_ONLINE] = { { [0] = 1UL } },
122#ifndef CONFIG_NUMA
123 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
124#ifdef CONFIG_HIGHMEM
125 [N_HIGH_MEMORY] = { { [0] = 1UL } },
126#endif
127 [N_MEMORY] = { { [0] = 1UL } },
128 [N_CPU] = { { [0] = 1UL } },
129#endif /* NUMA */
130};
131EXPORT_SYMBOL(node_states);
132
133atomic_long_t _totalram_pages __read_mostly;
134EXPORT_SYMBOL(_totalram_pages);
135unsigned long totalreserve_pages __read_mostly;
136unsigned long totalcma_pages __read_mostly;
137
138int percpu_pagelist_fraction;
139gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
140#ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
141DEFINE_STATIC_KEY_TRUE(init_on_alloc);
142#else
143DEFINE_STATIC_KEY_FALSE(init_on_alloc);
144#endif
145EXPORT_SYMBOL(init_on_alloc);
146
147#ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
148DEFINE_STATIC_KEY_TRUE(init_on_free);
149#else
150DEFINE_STATIC_KEY_FALSE(init_on_free);
151#endif
152EXPORT_SYMBOL(init_on_free);
153
154static int __init early_init_on_alloc(char *buf)
155{
156 int ret;
157 bool bool_result;
158
159 if (!buf)
160 return -EINVAL;
161 ret = kstrtobool(buf, &bool_result);
162 if (bool_result && page_poisoning_enabled())
163 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_alloc\n");
164 if (bool_result)
165 static_branch_enable(&init_on_alloc);
166 else
167 static_branch_disable(&init_on_alloc);
168 return ret;
169}
170early_param("init_on_alloc", early_init_on_alloc);
171
172static int __init early_init_on_free(char *buf)
173{
174 int ret;
175 bool bool_result;
176
177 if (!buf)
178 return -EINVAL;
179 ret = kstrtobool(buf, &bool_result);
180 if (bool_result && page_poisoning_enabled())
181 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_free\n");
182 if (bool_result)
183 static_branch_enable(&init_on_free);
184 else
185 static_branch_disable(&init_on_free);
186 return ret;
187}
188early_param("init_on_free", early_init_on_free);
189
190/*
191 * A cached value of the page's pageblock's migratetype, used when the page is
192 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
193 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
194 * Also the migratetype set in the page does not necessarily match the pcplist
195 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
196 * other index - this ensures that it will be put on the correct CMA freelist.
197 */
198static inline int get_pcppage_migratetype(struct page *page)
199{
200 return page->index;
201}
202
203static inline void set_pcppage_migratetype(struct page *page, int migratetype)
204{
205 page->index = migratetype;
206}
207
208#ifdef CONFIG_PM_SLEEP
209/*
210 * The following functions are used by the suspend/hibernate code to temporarily
211 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
212 * while devices are suspended. To avoid races with the suspend/hibernate code,
213 * they should always be called with system_transition_mutex held
214 * (gfp_allowed_mask also should only be modified with system_transition_mutex
215 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
216 * with that modification).
217 */
218
219static gfp_t saved_gfp_mask;
220
221void pm_restore_gfp_mask(void)
222{
223 WARN_ON(!mutex_is_locked(&system_transition_mutex));
224 if (saved_gfp_mask) {
225 gfp_allowed_mask = saved_gfp_mask;
226 saved_gfp_mask = 0;
227 }
228}
229
230void pm_restrict_gfp_mask(void)
231{
232 WARN_ON(!mutex_is_locked(&system_transition_mutex));
233 WARN_ON(saved_gfp_mask);
234 saved_gfp_mask = gfp_allowed_mask;
235 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
236}
237
238bool pm_suspended_storage(void)
239{
240 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
241 return false;
242 return true;
243}
244#endif /* CONFIG_PM_SLEEP */
245
246#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
247unsigned int pageblock_order __read_mostly;
248#endif
249
250static void __free_pages_ok(struct page *page, unsigned int order);
251
252/*
253 * results with 256, 32 in the lowmem_reserve sysctl:
254 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
255 * 1G machine -> (16M dma, 784M normal, 224M high)
256 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
257 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
258 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
259 *
260 * TBD: should special case ZONE_DMA32 machines here - in those we normally
261 * don't need any ZONE_NORMAL reservation
262 */
263int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
264#ifdef CONFIG_ZONE_DMA
265 [ZONE_DMA] = 256,
266#endif
267#ifdef CONFIG_ZONE_DMA32
268 [ZONE_DMA32] = 256,
269#endif
270 [ZONE_NORMAL] = 32,
271#ifdef CONFIG_HIGHMEM
272 [ZONE_HIGHMEM] = 0,
273#endif
274 [ZONE_MOVABLE] = 0,
275};
276
277static char * const zone_names[MAX_NR_ZONES] = {
278#ifdef CONFIG_ZONE_DMA
279 "DMA",
280#endif
281#ifdef CONFIG_ZONE_DMA32
282 "DMA32",
283#endif
284 "Normal",
285#ifdef CONFIG_HIGHMEM
286 "HighMem",
287#endif
288 "Movable",
289#ifdef CONFIG_ZONE_DEVICE
290 "Device",
291#endif
292};
293
294const char * const migratetype_names[MIGRATE_TYPES] = {
295 "Unmovable",
296 "Movable",
297 "Reclaimable",
298 "HighAtomic",
299#ifdef CONFIG_CMA
300 "CMA",
301#endif
302#ifdef CONFIG_MEMORY_ISOLATION
303 "Isolate",
304#endif
305};
306
307compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {
308 [NULL_COMPOUND_DTOR] = NULL,
309 [COMPOUND_PAGE_DTOR] = free_compound_page,
310#ifdef CONFIG_HUGETLB_PAGE
311 [HUGETLB_PAGE_DTOR] = free_huge_page,
312#endif
313#ifdef CONFIG_TRANSPARENT_HUGEPAGE
314 [TRANSHUGE_PAGE_DTOR] = free_transhuge_page,
315#endif
316};
317
318int min_free_kbytes = 1024;
319int user_min_free_kbytes = -1;
320#ifdef CONFIG_DISCONTIGMEM
321/*
322 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
323 * are not on separate NUMA nodes. Functionally this works but with
324 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
325 * quite small. By default, do not boost watermarks on discontigmem as in
326 * many cases very high-order allocations like THP are likely to be
327 * unsupported and the premature reclaim offsets the advantage of long-term
328 * fragmentation avoidance.
329 */
330int watermark_boost_factor __read_mostly;
331#else
332int watermark_boost_factor __read_mostly = 15000;
333#endif
334int watermark_scale_factor = 10;
335
336static unsigned long nr_kernel_pages __initdata;
337static unsigned long nr_all_pages __initdata;
338static unsigned long dma_reserve __initdata;
339
340static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata;
341static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata;
342static unsigned long required_kernelcore __initdata;
343static unsigned long required_kernelcore_percent __initdata;
344static unsigned long required_movablecore __initdata;
345static unsigned long required_movablecore_percent __initdata;
346static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
347static bool mirrored_kernelcore __meminitdata;
348
349/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
350int movable_zone;
351EXPORT_SYMBOL(movable_zone);
352
353#if MAX_NUMNODES > 1
354unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
355unsigned int nr_online_nodes __read_mostly = 1;
356EXPORT_SYMBOL(nr_node_ids);
357EXPORT_SYMBOL(nr_online_nodes);
358#endif
359
360int page_group_by_mobility_disabled __read_mostly;
361
362#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
363/*
364 * During boot we initialize deferred pages on-demand, as needed, but once
365 * page_alloc_init_late() has finished, the deferred pages are all initialized,
366 * and we can permanently disable that path.
367 */
368static DEFINE_STATIC_KEY_TRUE(deferred_pages);
369
370/*
371 * Calling kasan_free_pages() only after deferred memory initialization
372 * has completed. Poisoning pages during deferred memory init will greatly
373 * lengthen the process and cause problem in large memory systems as the
374 * deferred pages initialization is done with interrupt disabled.
375 *
376 * Assuming that there will be no reference to those newly initialized
377 * pages before they are ever allocated, this should have no effect on
378 * KASAN memory tracking as the poison will be properly inserted at page
379 * allocation time. The only corner case is when pages are allocated by
380 * on-demand allocation and then freed again before the deferred pages
381 * initialization is done, but this is not likely to happen.
382 */
383static inline void kasan_free_nondeferred_pages(struct page *page, int order)
384{
385 if (!static_branch_unlikely(&deferred_pages))
386 kasan_free_pages(page, order);
387}
388
389/* Returns true if the struct page for the pfn is uninitialised */
390static inline bool __meminit early_page_uninitialised(unsigned long pfn)
391{
392 int nid = early_pfn_to_nid(pfn);
393
394 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
395 return true;
396
397 return false;
398}
399
400/*
401 * Returns true when the remaining initialisation should be deferred until
402 * later in the boot cycle when it can be parallelised.
403 */
404static bool __meminit
405defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
406{
407 static unsigned long prev_end_pfn, nr_initialised;
408
409 /*
410 * prev_end_pfn static that contains the end of previous zone
411 * No need to protect because called very early in boot before smp_init.
412 */
413 if (prev_end_pfn != end_pfn) {
414 prev_end_pfn = end_pfn;
415 nr_initialised = 0;
416 }
417
418 /* Always populate low zones for address-constrained allocations */
419 if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
420 return false;
421
422 /*
423 * We start only with one section of pages, more pages are added as
424 * needed until the rest of deferred pages are initialized.
425 */
426 nr_initialised++;
427 if ((nr_initialised > PAGES_PER_SECTION) &&
428 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
429 NODE_DATA(nid)->first_deferred_pfn = pfn;
430 return true;
431 }
432 return false;
433}
434#else
435#define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
436
437static inline bool early_page_uninitialised(unsigned long pfn)
438{
439 return false;
440}
441
442static inline bool defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
443{
444 return false;
445}
446#endif
447
448/* Return a pointer to the bitmap storing bits affecting a block of pages */
449static inline unsigned long *get_pageblock_bitmap(struct page *page,
450 unsigned long pfn)
451{
452#ifdef CONFIG_SPARSEMEM
453 return section_to_usemap(__pfn_to_section(pfn));
454#else
455 return page_zone(page)->pageblock_flags;
456#endif /* CONFIG_SPARSEMEM */
457}
458
459static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
460{
461#ifdef CONFIG_SPARSEMEM
462 pfn &= (PAGES_PER_SECTION-1);
463#else
464 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
465#endif /* CONFIG_SPARSEMEM */
466 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
467}
468
469/**
470 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
471 * @page: The page within the block of interest
472 * @pfn: The target page frame number
473 * @mask: mask of bits that the caller is interested in
474 *
475 * Return: pageblock_bits flags
476 */
477static __always_inline
478unsigned long __get_pfnblock_flags_mask(struct page *page,
479 unsigned long pfn,
480 unsigned long mask)
481{
482 unsigned long *bitmap;
483 unsigned long bitidx, word_bitidx;
484 unsigned long word;
485
486 bitmap = get_pageblock_bitmap(page, pfn);
487 bitidx = pfn_to_bitidx(page, pfn);
488 word_bitidx = bitidx / BITS_PER_LONG;
489 bitidx &= (BITS_PER_LONG-1);
490
491 word = bitmap[word_bitidx];
492 return (word >> bitidx) & mask;
493}
494
495unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
496 unsigned long mask)
497{
498 return __get_pfnblock_flags_mask(page, pfn, mask);
499}
500
501static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
502{
503 return __get_pfnblock_flags_mask(page, pfn, MIGRATETYPE_MASK);
504}
505
506/**
507 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
508 * @page: The page within the block of interest
509 * @flags: The flags to set
510 * @pfn: The target page frame number
511 * @mask: mask of bits that the caller is interested in
512 */
513void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
514 unsigned long pfn,
515 unsigned long mask)
516{
517 unsigned long *bitmap;
518 unsigned long bitidx, word_bitidx;
519 unsigned long old_word, word;
520
521 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
522 BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
523
524 bitmap = get_pageblock_bitmap(page, pfn);
525 bitidx = pfn_to_bitidx(page, pfn);
526 word_bitidx = bitidx / BITS_PER_LONG;
527 bitidx &= (BITS_PER_LONG-1);
528
529 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
530
531 mask <<= bitidx;
532 flags <<= bitidx;
533
534 word = READ_ONCE(bitmap[word_bitidx]);
535 for (;;) {
536 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
537 if (word == old_word)
538 break;
539 word = old_word;
540 }
541}
542
543void set_pageblock_migratetype(struct page *page, int migratetype)
544{
545 if (unlikely(page_group_by_mobility_disabled &&
546 migratetype < MIGRATE_PCPTYPES))
547 migratetype = MIGRATE_UNMOVABLE;
548
549 set_pfnblock_flags_mask(page, (unsigned long)migratetype,
550 page_to_pfn(page), MIGRATETYPE_MASK);
551}
552
553#ifdef CONFIG_DEBUG_VM
554static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
555{
556 int ret = 0;
557 unsigned seq;
558 unsigned long pfn = page_to_pfn(page);
559 unsigned long sp, start_pfn;
560
561 do {
562 seq = zone_span_seqbegin(zone);
563 start_pfn = zone->zone_start_pfn;
564 sp = zone->spanned_pages;
565 if (!zone_spans_pfn(zone, pfn))
566 ret = 1;
567 } while (zone_span_seqretry(zone, seq));
568
569 if (ret)
570 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
571 pfn, zone_to_nid(zone), zone->name,
572 start_pfn, start_pfn + sp);
573
574 return ret;
575}
576
577static int page_is_consistent(struct zone *zone, struct page *page)
578{
579 if (!pfn_valid_within(page_to_pfn(page)))
580 return 0;
581 if (zone != page_zone(page))
582 return 0;
583
584 return 1;
585}
586/*
587 * Temporary debugging check for pages not lying within a given zone.
588 */
589static int __maybe_unused bad_range(struct zone *zone, struct page *page)
590{
591 if (page_outside_zone_boundaries(zone, page))
592 return 1;
593 if (!page_is_consistent(zone, page))
594 return 1;
595
596 return 0;
597}
598#else
599static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
600{
601 return 0;
602}
603#endif
604
605static void bad_page(struct page *page, const char *reason)
606{
607 static unsigned long resume;
608 static unsigned long nr_shown;
609 static unsigned long nr_unshown;
610
611 /*
612 * Allow a burst of 60 reports, then keep quiet for that minute;
613 * or allow a steady drip of one report per second.
614 */
615 if (nr_shown == 60) {
616 if (time_before(jiffies, resume)) {
617 nr_unshown++;
618 goto out;
619 }
620 if (nr_unshown) {
621 pr_alert(
622 "BUG: Bad page state: %lu messages suppressed\n",
623 nr_unshown);
624 nr_unshown = 0;
625 }
626 nr_shown = 0;
627 }
628 if (nr_shown++ == 0)
629 resume = jiffies + 60 * HZ;
630
631 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
632 current->comm, page_to_pfn(page));
633 __dump_page(page, reason);
634 dump_page_owner(page);
635
636 print_modules();
637 dump_stack();
638out:
639 /* Leave bad fields for debug, except PageBuddy could make trouble */
640 page_mapcount_reset(page); /* remove PageBuddy */
641 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
642}
643
644/*
645 * Higher-order pages are called "compound pages". They are structured thusly:
646 *
647 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
648 *
649 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
650 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
651 *
652 * The first tail page's ->compound_dtor holds the offset in array of compound
653 * page destructors. See compound_page_dtors.
654 *
655 * The first tail page's ->compound_order holds the order of allocation.
656 * This usage means that zero-order pages may not be compound.
657 */
658
659void free_compound_page(struct page *page)
660{
661 mem_cgroup_uncharge(page);
662 __free_pages_ok(page, compound_order(page));
663}
664
665void prep_compound_page(struct page *page, unsigned int order)
666{
667 int i;
668 int nr_pages = 1 << order;
669
670 __SetPageHead(page);
671 for (i = 1; i < nr_pages; i++) {
672 struct page *p = page + i;
673 set_page_count(p, 0);
674 p->mapping = TAIL_MAPPING;
675 set_compound_head(p, page);
676 }
677
678 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
679 set_compound_order(page, order);
680 atomic_set(compound_mapcount_ptr(page), -1);
681 if (hpage_pincount_available(page))
682 atomic_set(compound_pincount_ptr(page), 0);
683}
684
685#ifdef CONFIG_DEBUG_PAGEALLOC
686unsigned int _debug_guardpage_minorder;
687
688bool _debug_pagealloc_enabled_early __read_mostly
689 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
690EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
691DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
692EXPORT_SYMBOL(_debug_pagealloc_enabled);
693
694DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
695
696static int __init early_debug_pagealloc(char *buf)
697{
698 return kstrtobool(buf, &_debug_pagealloc_enabled_early);
699}
700early_param("debug_pagealloc", early_debug_pagealloc);
701
702void init_debug_pagealloc(void)
703{
704 if (!debug_pagealloc_enabled())
705 return;
706
707 static_branch_enable(&_debug_pagealloc_enabled);
708
709 if (!debug_guardpage_minorder())
710 return;
711
712 static_branch_enable(&_debug_guardpage_enabled);
713}
714
715static int __init debug_guardpage_minorder_setup(char *buf)
716{
717 unsigned long res;
718
719 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
720 pr_err("Bad debug_guardpage_minorder value\n");
721 return 0;
722 }
723 _debug_guardpage_minorder = res;
724 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
725 return 0;
726}
727early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
728
729static inline bool set_page_guard(struct zone *zone, struct page *page,
730 unsigned int order, int migratetype)
731{
732 if (!debug_guardpage_enabled())
733 return false;
734
735 if (order >= debug_guardpage_minorder())
736 return false;
737
738 __SetPageGuard(page);
739 INIT_LIST_HEAD(&page->lru);
740 set_page_private(page, order);
741 /* Guard pages are not available for any usage */
742 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
743
744 return true;
745}
746
747static inline void clear_page_guard(struct zone *zone, struct page *page,
748 unsigned int order, int migratetype)
749{
750 if (!debug_guardpage_enabled())
751 return;
752
753 __ClearPageGuard(page);
754
755 set_page_private(page, 0);
756 if (!is_migrate_isolate(migratetype))
757 __mod_zone_freepage_state(zone, (1 << order), migratetype);
758}
759#else
760static inline bool set_page_guard(struct zone *zone, struct page *page,
761 unsigned int order, int migratetype) { return false; }
762static inline void clear_page_guard(struct zone *zone, struct page *page,
763 unsigned int order, int migratetype) {}
764#endif
765
766static inline void set_page_order(struct page *page, unsigned int order)
767{
768 set_page_private(page, order);
769 __SetPageBuddy(page);
770}
771
772/*
773 * This function checks whether a page is free && is the buddy
774 * we can coalesce a page and its buddy if
775 * (a) the buddy is not in a hole (check before calling!) &&
776 * (b) the buddy is in the buddy system &&
777 * (c) a page and its buddy have the same order &&
778 * (d) a page and its buddy are in the same zone.
779 *
780 * For recording whether a page is in the buddy system, we set PageBuddy.
781 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
782 *
783 * For recording page's order, we use page_private(page).
784 */
785static inline bool page_is_buddy(struct page *page, struct page *buddy,
786 unsigned int order)
787{
788 if (!page_is_guard(buddy) && !PageBuddy(buddy))
789 return false;
790
791 if (page_order(buddy) != order)
792 return false;
793
794 /*
795 * zone check is done late to avoid uselessly calculating
796 * zone/node ids for pages that could never merge.
797 */
798 if (page_zone_id(page) != page_zone_id(buddy))
799 return false;
800
801 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
802
803 return true;
804}
805
806#ifdef CONFIG_COMPACTION
807static inline struct capture_control *task_capc(struct zone *zone)
808{
809 struct capture_control *capc = current->capture_control;
810
811 return unlikely(capc) &&
812 !(current->flags & PF_KTHREAD) &&
813 !capc->page &&
814 capc->cc->zone == zone ? capc : NULL;
815}
816
817static inline bool
818compaction_capture(struct capture_control *capc, struct page *page,
819 int order, int migratetype)
820{
821 if (!capc || order != capc->cc->order)
822 return false;
823
824 /* Do not accidentally pollute CMA or isolated regions*/
825 if (is_migrate_cma(migratetype) ||
826 is_migrate_isolate(migratetype))
827 return false;
828
829 /*
830 * Do not let lower order allocations polluate a movable pageblock.
831 * This might let an unmovable request use a reclaimable pageblock
832 * and vice-versa but no more than normal fallback logic which can
833 * have trouble finding a high-order free page.
834 */
835 if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
836 return false;
837
838 capc->page = page;
839 return true;
840}
841
842#else
843static inline struct capture_control *task_capc(struct zone *zone)
844{
845 return NULL;
846}
847
848static inline bool
849compaction_capture(struct capture_control *capc, struct page *page,
850 int order, int migratetype)
851{
852 return false;
853}
854#endif /* CONFIG_COMPACTION */
855
856/* Used for pages not on another list */
857static inline void add_to_free_list(struct page *page, struct zone *zone,
858 unsigned int order, int migratetype)
859{
860 struct free_area *area = &zone->free_area[order];
861
862 list_add(&page->lru, &area->free_list[migratetype]);
863 area->nr_free++;
864}
865
866/* Used for pages not on another list */
867static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
868 unsigned int order, int migratetype)
869{
870 struct free_area *area = &zone->free_area[order];
871
872 list_add_tail(&page->lru, &area->free_list[migratetype]);
873 area->nr_free++;
874}
875
876/* Used for pages which are on another list */
877static inline void move_to_free_list(struct page *page, struct zone *zone,
878 unsigned int order, int migratetype)
879{
880 struct free_area *area = &zone->free_area[order];
881
882 list_move(&page->lru, &area->free_list[migratetype]);
883}
884
885static inline void del_page_from_free_list(struct page *page, struct zone *zone,
886 unsigned int order)
887{
888 /* clear reported state and update reported page count */
889 if (page_reported(page))
890 __ClearPageReported(page);
891
892 list_del(&page->lru);
893 __ClearPageBuddy(page);
894 set_page_private(page, 0);
895 zone->free_area[order].nr_free--;
896}
897
898/*
899 * If this is not the largest possible page, check if the buddy
900 * of the next-highest order is free. If it is, it's possible
901 * that pages are being freed that will coalesce soon. In case,
902 * that is happening, add the free page to the tail of the list
903 * so it's less likely to be used soon and more likely to be merged
904 * as a higher order page
905 */
906static inline bool
907buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
908 struct page *page, unsigned int order)
909{
910 struct page *higher_page, *higher_buddy;
911 unsigned long combined_pfn;
912
913 if (order >= MAX_ORDER - 2)
914 return false;
915
916 if (!pfn_valid_within(buddy_pfn))
917 return false;
918
919 combined_pfn = buddy_pfn & pfn;
920 higher_page = page + (combined_pfn - pfn);
921 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
922 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
923
924 return pfn_valid_within(buddy_pfn) &&
925 page_is_buddy(higher_page, higher_buddy, order + 1);
926}
927
928/*
929 * Freeing function for a buddy system allocator.
930 *
931 * The concept of a buddy system is to maintain direct-mapped table
932 * (containing bit values) for memory blocks of various "orders".
933 * The bottom level table contains the map for the smallest allocatable
934 * units of memory (here, pages), and each level above it describes
935 * pairs of units from the levels below, hence, "buddies".
936 * At a high level, all that happens here is marking the table entry
937 * at the bottom level available, and propagating the changes upward
938 * as necessary, plus some accounting needed to play nicely with other
939 * parts of the VM system.
940 * At each level, we keep a list of pages, which are heads of continuous
941 * free pages of length of (1 << order) and marked with PageBuddy.
942 * Page's order is recorded in page_private(page) field.
943 * So when we are allocating or freeing one, we can derive the state of the
944 * other. That is, if we allocate a small block, and both were
945 * free, the remainder of the region must be split into blocks.
946 * If a block is freed, and its buddy is also free, then this
947 * triggers coalescing into a block of larger size.
948 *
949 * -- nyc
950 */
951
952static inline void __free_one_page(struct page *page,
953 unsigned long pfn,
954 struct zone *zone, unsigned int order,
955 int migratetype, bool report)
956{
957 struct capture_control *capc = task_capc(zone);
958 unsigned long buddy_pfn;
959 unsigned long combined_pfn;
960 unsigned int max_order;
961 struct page *buddy;
962 bool to_tail;
963
964 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
965
966 VM_BUG_ON(!zone_is_initialized(zone));
967 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
968
969 VM_BUG_ON(migratetype == -1);
970 if (likely(!is_migrate_isolate(migratetype)))
971 __mod_zone_freepage_state(zone, 1 << order, migratetype);
972
973 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
974 VM_BUG_ON_PAGE(bad_range(zone, page), page);
975
976continue_merging:
977 while (order < max_order - 1) {
978 if (compaction_capture(capc, page, order, migratetype)) {
979 __mod_zone_freepage_state(zone, -(1 << order),
980 migratetype);
981 return;
982 }
983 buddy_pfn = __find_buddy_pfn(pfn, order);
984 buddy = page + (buddy_pfn - pfn);
985
986 if (!pfn_valid_within(buddy_pfn))
987 goto done_merging;
988 if (!page_is_buddy(page, buddy, order))
989 goto done_merging;
990 /*
991 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
992 * merge with it and move up one order.
993 */
994 if (page_is_guard(buddy))
995 clear_page_guard(zone, buddy, order, migratetype);
996 else
997 del_page_from_free_list(buddy, zone, order);
998 combined_pfn = buddy_pfn & pfn;
999 page = page + (combined_pfn - pfn);
1000 pfn = combined_pfn;
1001 order++;
1002 }
1003 if (max_order < MAX_ORDER) {
1004 /* If we are here, it means order is >= pageblock_order.
1005 * We want to prevent merge between freepages on isolate
1006 * pageblock and normal pageblock. Without this, pageblock
1007 * isolation could cause incorrect freepage or CMA accounting.
1008 *
1009 * We don't want to hit this code for the more frequent
1010 * low-order merging.
1011 */
1012 if (unlikely(has_isolate_pageblock(zone))) {
1013 int buddy_mt;
1014
1015 buddy_pfn = __find_buddy_pfn(pfn, order);
1016 buddy = page + (buddy_pfn - pfn);
1017 buddy_mt = get_pageblock_migratetype(buddy);
1018
1019 if (migratetype != buddy_mt
1020 && (is_migrate_isolate(migratetype) ||
1021 is_migrate_isolate(buddy_mt)))
1022 goto done_merging;
1023 }
1024 max_order++;
1025 goto continue_merging;
1026 }
1027
1028done_merging:
1029 set_page_order(page, order);
1030
1031 if (is_shuffle_order(order))
1032 to_tail = shuffle_pick_tail();
1033 else
1034 to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
1035
1036 if (to_tail)
1037 add_to_free_list_tail(page, zone, order, migratetype);
1038 else
1039 add_to_free_list(page, zone, order, migratetype);
1040
1041 /* Notify page reporting subsystem of freed page */
1042 if (report)
1043 page_reporting_notify_free(order);
1044}
1045
1046/*
1047 * A bad page could be due to a number of fields. Instead of multiple branches,
1048 * try and check multiple fields with one check. The caller must do a detailed
1049 * check if necessary.
1050 */
1051static inline bool page_expected_state(struct page *page,
1052 unsigned long check_flags)
1053{
1054 if (unlikely(atomic_read(&page->_mapcount) != -1))
1055 return false;
1056
1057 if (unlikely((unsigned long)page->mapping |
1058 page_ref_count(page) |
1059#ifdef CONFIG_MEMCG
1060 (unsigned long)page->mem_cgroup |
1061#endif
1062 (page->flags & check_flags)))
1063 return false;
1064
1065 return true;
1066}
1067
1068static const char *page_bad_reason(struct page *page, unsigned long flags)
1069{
1070 const char *bad_reason = NULL;
1071
1072 if (unlikely(atomic_read(&page->_mapcount) != -1))
1073 bad_reason = "nonzero mapcount";
1074 if (unlikely(page->mapping != NULL))
1075 bad_reason = "non-NULL mapping";
1076 if (unlikely(page_ref_count(page) != 0))
1077 bad_reason = "nonzero _refcount";
1078 if (unlikely(page->flags & flags)) {
1079 if (flags == PAGE_FLAGS_CHECK_AT_PREP)
1080 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1081 else
1082 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1083 }
1084#ifdef CONFIG_MEMCG
1085 if (unlikely(page->mem_cgroup))
1086 bad_reason = "page still charged to cgroup";
1087#endif
1088 return bad_reason;
1089}
1090
1091static void check_free_page_bad(struct page *page)
1092{
1093 bad_page(page,
1094 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_FREE));
1095}
1096
1097static inline int check_free_page(struct page *page)
1098{
1099 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
1100 return 0;
1101
1102 /* Something has gone sideways, find it */
1103 check_free_page_bad(page);
1104 return 1;
1105}
1106
1107static int free_tail_pages_check(struct page *head_page, struct page *page)
1108{
1109 int ret = 1;
1110
1111 /*
1112 * We rely page->lru.next never has bit 0 set, unless the page
1113 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1114 */
1115 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
1116
1117 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
1118 ret = 0;
1119 goto out;
1120 }
1121 switch (page - head_page) {
1122 case 1:
1123 /* the first tail page: ->mapping may be compound_mapcount() */
1124 if (unlikely(compound_mapcount(page))) {
1125 bad_page(page, "nonzero compound_mapcount");
1126 goto out;
1127 }
1128 break;
1129 case 2:
1130 /*
1131 * the second tail page: ->mapping is
1132 * deferred_list.next -- ignore value.
1133 */
1134 break;
1135 default:
1136 if (page->mapping != TAIL_MAPPING) {
1137 bad_page(page, "corrupted mapping in tail page");
1138 goto out;
1139 }
1140 break;
1141 }
1142 if (unlikely(!PageTail(page))) {
1143 bad_page(page, "PageTail not set");
1144 goto out;
1145 }
1146 if (unlikely(compound_head(page) != head_page)) {
1147 bad_page(page, "compound_head not consistent");
1148 goto out;
1149 }
1150 ret = 0;
1151out:
1152 page->mapping = NULL;
1153 clear_compound_head(page);
1154 return ret;
1155}
1156
1157static void kernel_init_free_pages(struct page *page, int numpages)
1158{
1159 int i;
1160
1161 /* s390's use of memset() could override KASAN redzones. */
1162 kasan_disable_current();
1163 for (i = 0; i < numpages; i++)
1164 clear_highpage(page + i);
1165 kasan_enable_current();
1166}
1167
1168static __always_inline bool free_pages_prepare(struct page *page,
1169 unsigned int order, bool check_free)
1170{
1171 int bad = 0;
1172
1173 VM_BUG_ON_PAGE(PageTail(page), page);
1174
1175 trace_mm_page_free(page, order);
1176
1177 /*
1178 * Check tail pages before head page information is cleared to
1179 * avoid checking PageCompound for order-0 pages.
1180 */
1181 if (unlikely(order)) {
1182 bool compound = PageCompound(page);
1183 int i;
1184
1185 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1186
1187 if (compound)
1188 ClearPageDoubleMap(page);
1189 for (i = 1; i < (1 << order); i++) {
1190 if (compound)
1191 bad += free_tail_pages_check(page, page + i);
1192 if (unlikely(check_free_page(page + i))) {
1193 bad++;
1194 continue;
1195 }
1196 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1197 }
1198 }
1199 if (PageMappingFlags(page))
1200 page->mapping = NULL;
1201 if (memcg_kmem_enabled() && PageKmemcg(page))
1202 __memcg_kmem_uncharge_page(page, order);
1203 if (check_free)
1204 bad += check_free_page(page);
1205 if (bad)
1206 return false;
1207
1208 page_cpupid_reset_last(page);
1209 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1210 reset_page_owner(page, order);
1211
1212 if (!PageHighMem(page)) {
1213 debug_check_no_locks_freed(page_address(page),
1214 PAGE_SIZE << order);
1215 debug_check_no_obj_freed(page_address(page),
1216 PAGE_SIZE << order);
1217 }
1218 if (want_init_on_free())
1219 kernel_init_free_pages(page, 1 << order);
1220
1221 kernel_poison_pages(page, 1 << order, 0);
1222 /*
1223 * arch_free_page() can make the page's contents inaccessible. s390
1224 * does this. So nothing which can access the page's contents should
1225 * happen after this.
1226 */
1227 arch_free_page(page, order);
1228
1229 if (debug_pagealloc_enabled_static())
1230 kernel_map_pages(page, 1 << order, 0);
1231
1232 kasan_free_nondeferred_pages(page, order);
1233
1234 return true;
1235}
1236
1237#ifdef CONFIG_DEBUG_VM
1238/*
1239 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1240 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1241 * moved from pcp lists to free lists.
1242 */
1243static bool free_pcp_prepare(struct page *page)
1244{
1245 return free_pages_prepare(page, 0, true);
1246}
1247
1248static bool bulkfree_pcp_prepare(struct page *page)
1249{
1250 if (debug_pagealloc_enabled_static())
1251 return check_free_page(page);
1252 else
1253 return false;
1254}
1255#else
1256/*
1257 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1258 * moving from pcp lists to free list in order to reduce overhead. With
1259 * debug_pagealloc enabled, they are checked also immediately when being freed
1260 * to the pcp lists.
1261 */
1262static bool free_pcp_prepare(struct page *page)
1263{
1264 if (debug_pagealloc_enabled_static())
1265 return free_pages_prepare(page, 0, true);
1266 else
1267 return free_pages_prepare(page, 0, false);
1268}
1269
1270static bool bulkfree_pcp_prepare(struct page *page)
1271{
1272 return check_free_page(page);
1273}
1274#endif /* CONFIG_DEBUG_VM */
1275
1276static inline void prefetch_buddy(struct page *page)
1277{
1278 unsigned long pfn = page_to_pfn(page);
1279 unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0);
1280 struct page *buddy = page + (buddy_pfn - pfn);
1281
1282 prefetch(buddy);
1283}
1284
1285/*
1286 * Frees a number of pages from the PCP lists
1287 * Assumes all pages on list are in same zone, and of same order.
1288 * count is the number of pages to free.
1289 *
1290 * If the zone was previously in an "all pages pinned" state then look to
1291 * see if this freeing clears that state.
1292 *
1293 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1294 * pinned" detection logic.
1295 */
1296static void free_pcppages_bulk(struct zone *zone, int count,
1297 struct per_cpu_pages *pcp)
1298{
1299 int migratetype = 0;
1300 int batch_free = 0;
1301 int prefetch_nr = 0;
1302 bool isolated_pageblocks;
1303 struct page *page, *tmp;
1304 LIST_HEAD(head);
1305
1306 /*
1307 * Ensure proper count is passed which otherwise would stuck in the
1308 * below while (list_empty(list)) loop.
1309 */
1310 count = min(pcp->count, count);
1311 while (count) {
1312 struct list_head *list;
1313
1314 /*
1315 * Remove pages from lists in a round-robin fashion. A
1316 * batch_free count is maintained that is incremented when an
1317 * empty list is encountered. This is so more pages are freed
1318 * off fuller lists instead of spinning excessively around empty
1319 * lists
1320 */
1321 do {
1322 batch_free++;
1323 if (++migratetype == MIGRATE_PCPTYPES)
1324 migratetype = 0;
1325 list = &pcp->lists[migratetype];
1326 } while (list_empty(list));
1327
1328 /* This is the only non-empty list. Free them all. */
1329 if (batch_free == MIGRATE_PCPTYPES)
1330 batch_free = count;
1331
1332 do {
1333 page = list_last_entry(list, struct page, lru);
1334 /* must delete to avoid corrupting pcp list */
1335 list_del(&page->lru);
1336 pcp->count--;
1337
1338 if (bulkfree_pcp_prepare(page))
1339 continue;
1340
1341 list_add_tail(&page->lru, &head);
1342
1343 /*
1344 * We are going to put the page back to the global
1345 * pool, prefetch its buddy to speed up later access
1346 * under zone->lock. It is believed the overhead of
1347 * an additional test and calculating buddy_pfn here
1348 * can be offset by reduced memory latency later. To
1349 * avoid excessive prefetching due to large count, only
1350 * prefetch buddy for the first pcp->batch nr of pages.
1351 */
1352 if (prefetch_nr++ < pcp->batch)
1353 prefetch_buddy(page);
1354 } while (--count && --batch_free && !list_empty(list));
1355 }
1356
1357 spin_lock(&zone->lock);
1358 isolated_pageblocks = has_isolate_pageblock(zone);
1359
1360 /*
1361 * Use safe version since after __free_one_page(),
1362 * page->lru.next will not point to original list.
1363 */
1364 list_for_each_entry_safe(page, tmp, &head, lru) {
1365 int mt = get_pcppage_migratetype(page);
1366 /* MIGRATE_ISOLATE page should not go to pcplists */
1367 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1368 /* Pageblock could have been isolated meanwhile */
1369 if (unlikely(isolated_pageblocks))
1370 mt = get_pageblock_migratetype(page);
1371
1372 __free_one_page(page, page_to_pfn(page), zone, 0, mt, true);
1373 trace_mm_page_pcpu_drain(page, 0, mt);
1374 }
1375 spin_unlock(&zone->lock);
1376}
1377
1378static void free_one_page(struct zone *zone,
1379 struct page *page, unsigned long pfn,
1380 unsigned int order,
1381 int migratetype)
1382{
1383 spin_lock(&zone->lock);
1384 if (unlikely(has_isolate_pageblock(zone) ||
1385 is_migrate_isolate(migratetype))) {
1386 migratetype = get_pfnblock_migratetype(page, pfn);
1387 }
1388 __free_one_page(page, pfn, zone, order, migratetype, true);
1389 spin_unlock(&zone->lock);
1390}
1391
1392static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1393 unsigned long zone, int nid)
1394{
1395 mm_zero_struct_page(page);
1396 set_page_links(page, zone, nid, pfn);
1397 init_page_count(page);
1398 page_mapcount_reset(page);
1399 page_cpupid_reset_last(page);
1400 page_kasan_tag_reset(page);
1401
1402 INIT_LIST_HEAD(&page->lru);
1403#ifdef WANT_PAGE_VIRTUAL
1404 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1405 if (!is_highmem_idx(zone))
1406 set_page_address(page, __va(pfn << PAGE_SHIFT));
1407#endif
1408}
1409
1410#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1411static void __meminit init_reserved_page(unsigned long pfn)
1412{
1413 pg_data_t *pgdat;
1414 int nid, zid;
1415
1416 if (!early_page_uninitialised(pfn))
1417 return;
1418
1419 nid = early_pfn_to_nid(pfn);
1420 pgdat = NODE_DATA(nid);
1421
1422 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1423 struct zone *zone = &pgdat->node_zones[zid];
1424
1425 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1426 break;
1427 }
1428 __init_single_page(pfn_to_page(pfn), pfn, zid, nid);
1429}
1430#else
1431static inline void init_reserved_page(unsigned long pfn)
1432{
1433}
1434#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1435
1436/*
1437 * Initialised pages do not have PageReserved set. This function is
1438 * called for each range allocated by the bootmem allocator and
1439 * marks the pages PageReserved. The remaining valid pages are later
1440 * sent to the buddy page allocator.
1441 */
1442void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1443{
1444 unsigned long start_pfn = PFN_DOWN(start);
1445 unsigned long end_pfn = PFN_UP(end);
1446
1447 for (; start_pfn < end_pfn; start_pfn++) {
1448 if (pfn_valid(start_pfn)) {
1449 struct page *page = pfn_to_page(start_pfn);
1450
1451 init_reserved_page(start_pfn);
1452
1453 /* Avoid false-positive PageTail() */
1454 INIT_LIST_HEAD(&page->lru);
1455
1456 /*
1457 * no need for atomic set_bit because the struct
1458 * page is not visible yet so nobody should
1459 * access it yet.
1460 */
1461 __SetPageReserved(page);
1462 }
1463 }
1464}
1465
1466static void __free_pages_ok(struct page *page, unsigned int order)
1467{
1468 unsigned long flags;
1469 int migratetype;
1470 unsigned long pfn = page_to_pfn(page);
1471
1472 if (!free_pages_prepare(page, order, true))
1473 return;
1474
1475 migratetype = get_pfnblock_migratetype(page, pfn);
1476 local_irq_save(flags);
1477 __count_vm_events(PGFREE, 1 << order);
1478 free_one_page(page_zone(page), page, pfn, order, migratetype);
1479 local_irq_restore(flags);
1480}
1481
1482void __free_pages_core(struct page *page, unsigned int order)
1483{
1484 unsigned int nr_pages = 1 << order;
1485 struct page *p = page;
1486 unsigned int loop;
1487
1488 prefetchw(p);
1489 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1490 prefetchw(p + 1);
1491 __ClearPageReserved(p);
1492 set_page_count(p, 0);
1493 }
1494 __ClearPageReserved(p);
1495 set_page_count(p, 0);
1496
1497 atomic_long_add(nr_pages, &page_zone(page)->managed_pages);
1498 set_page_refcounted(page);
1499 __free_pages(page, order);
1500}
1501
1502#ifdef CONFIG_NEED_MULTIPLE_NODES
1503
1504static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1505
1506#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1507
1508/*
1509 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1510 */
1511int __meminit __early_pfn_to_nid(unsigned long pfn,
1512 struct mminit_pfnnid_cache *state)
1513{
1514 unsigned long start_pfn, end_pfn;
1515 int nid;
1516
1517 if (state->last_start <= pfn && pfn < state->last_end)
1518 return state->last_nid;
1519
1520 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
1521 if (nid != NUMA_NO_NODE) {
1522 state->last_start = start_pfn;
1523 state->last_end = end_pfn;
1524 state->last_nid = nid;
1525 }
1526
1527 return nid;
1528}
1529#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1530
1531int __meminit early_pfn_to_nid(unsigned long pfn)
1532{
1533 static DEFINE_SPINLOCK(early_pfn_lock);
1534 int nid;
1535
1536 spin_lock(&early_pfn_lock);
1537 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1538 if (nid < 0)
1539 nid = first_online_node;
1540 spin_unlock(&early_pfn_lock);
1541
1542 return nid;
1543}
1544#endif /* CONFIG_NEED_MULTIPLE_NODES */
1545
1546void __init memblock_free_pages(struct page *page, unsigned long pfn,
1547 unsigned int order)
1548{
1549 if (early_page_uninitialised(pfn))
1550 return;
1551 __free_pages_core(page, order);
1552}
1553
1554/*
1555 * Check that the whole (or subset of) a pageblock given by the interval of
1556 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1557 * with the migration of free compaction scanner. The scanners then need to
1558 * use only pfn_valid_within() check for arches that allow holes within
1559 * pageblocks.
1560 *
1561 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1562 *
1563 * It's possible on some configurations to have a setup like node0 node1 node0
1564 * i.e. it's possible that all pages within a zones range of pages do not
1565 * belong to a single zone. We assume that a border between node0 and node1
1566 * can occur within a single pageblock, but not a node0 node1 node0
1567 * interleaving within a single pageblock. It is therefore sufficient to check
1568 * the first and last page of a pageblock and avoid checking each individual
1569 * page in a pageblock.
1570 */
1571struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1572 unsigned long end_pfn, struct zone *zone)
1573{
1574 struct page *start_page;
1575 struct page *end_page;
1576
1577 /* end_pfn is one past the range we are checking */
1578 end_pfn--;
1579
1580 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1581 return NULL;
1582
1583 start_page = pfn_to_online_page(start_pfn);
1584 if (!start_page)
1585 return NULL;
1586
1587 if (page_zone(start_page) != zone)
1588 return NULL;
1589
1590 end_page = pfn_to_page(end_pfn);
1591
1592 /* This gives a shorter code than deriving page_zone(end_page) */
1593 if (page_zone_id(start_page) != page_zone_id(end_page))
1594 return NULL;
1595
1596 return start_page;
1597}
1598
1599void set_zone_contiguous(struct zone *zone)
1600{
1601 unsigned long block_start_pfn = zone->zone_start_pfn;
1602 unsigned long block_end_pfn;
1603
1604 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1605 for (; block_start_pfn < zone_end_pfn(zone);
1606 block_start_pfn = block_end_pfn,
1607 block_end_pfn += pageblock_nr_pages) {
1608
1609 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1610
1611 if (!__pageblock_pfn_to_page(block_start_pfn,
1612 block_end_pfn, zone))
1613 return;
1614 cond_resched();
1615 }
1616
1617 /* We confirm that there is no hole */
1618 zone->contiguous = true;
1619}
1620
1621void clear_zone_contiguous(struct zone *zone)
1622{
1623 zone->contiguous = false;
1624}
1625
1626#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1627static void __init deferred_free_range(unsigned long pfn,
1628 unsigned long nr_pages)
1629{
1630 struct page *page;
1631 unsigned long i;
1632
1633 if (!nr_pages)
1634 return;
1635
1636 page = pfn_to_page(pfn);
1637
1638 /* Free a large naturally-aligned chunk if possible */
1639 if (nr_pages == pageblock_nr_pages &&
1640 (pfn & (pageblock_nr_pages - 1)) == 0) {
1641 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1642 __free_pages_core(page, pageblock_order);
1643 return;
1644 }
1645
1646 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1647 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1648 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1649 __free_pages_core(page, 0);
1650 }
1651}
1652
1653/* Completion tracking for deferred_init_memmap() threads */
1654static atomic_t pgdat_init_n_undone __initdata;
1655static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1656
1657static inline void __init pgdat_init_report_one_done(void)
1658{
1659 if (atomic_dec_and_test(&pgdat_init_n_undone))
1660 complete(&pgdat_init_all_done_comp);
1661}
1662
1663/*
1664 * Returns true if page needs to be initialized or freed to buddy allocator.
1665 *
1666 * First we check if pfn is valid on architectures where it is possible to have
1667 * holes within pageblock_nr_pages. On systems where it is not possible, this
1668 * function is optimized out.
1669 *
1670 * Then, we check if a current large page is valid by only checking the validity
1671 * of the head pfn.
1672 */
1673static inline bool __init deferred_pfn_valid(unsigned long pfn)
1674{
1675 if (!pfn_valid_within(pfn))
1676 return false;
1677 if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
1678 return false;
1679 return true;
1680}
1681
1682/*
1683 * Free pages to buddy allocator. Try to free aligned pages in
1684 * pageblock_nr_pages sizes.
1685 */
1686static void __init deferred_free_pages(unsigned long pfn,
1687 unsigned long end_pfn)
1688{
1689 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1690 unsigned long nr_free = 0;
1691
1692 for (; pfn < end_pfn; pfn++) {
1693 if (!deferred_pfn_valid(pfn)) {
1694 deferred_free_range(pfn - nr_free, nr_free);
1695 nr_free = 0;
1696 } else if (!(pfn & nr_pgmask)) {
1697 deferred_free_range(pfn - nr_free, nr_free);
1698 nr_free = 1;
1699 } else {
1700 nr_free++;
1701 }
1702 }
1703 /* Free the last block of pages to allocator */
1704 deferred_free_range(pfn - nr_free, nr_free);
1705}
1706
1707/*
1708 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1709 * by performing it only once every pageblock_nr_pages.
1710 * Return number of pages initialized.
1711 */
1712static unsigned long __init deferred_init_pages(struct zone *zone,
1713 unsigned long pfn,
1714 unsigned long end_pfn)
1715{
1716 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1717 int nid = zone_to_nid(zone);
1718 unsigned long nr_pages = 0;
1719 int zid = zone_idx(zone);
1720 struct page *page = NULL;
1721
1722 for (; pfn < end_pfn; pfn++) {
1723 if (!deferred_pfn_valid(pfn)) {
1724 page = NULL;
1725 continue;
1726 } else if (!page || !(pfn & nr_pgmask)) {
1727 page = pfn_to_page(pfn);
1728 } else {
1729 page++;
1730 }
1731 __init_single_page(page, pfn, zid, nid);
1732 nr_pages++;
1733 }
1734 return (nr_pages);
1735}
1736
1737/*
1738 * This function is meant to pre-load the iterator for the zone init.
1739 * Specifically it walks through the ranges until we are caught up to the
1740 * first_init_pfn value and exits there. If we never encounter the value we
1741 * return false indicating there are no valid ranges left.
1742 */
1743static bool __init
1744deferred_init_mem_pfn_range_in_zone(u64 *i, struct zone *zone,
1745 unsigned long *spfn, unsigned long *epfn,
1746 unsigned long first_init_pfn)
1747{
1748 u64 j;
1749
1750 /*
1751 * Start out by walking through the ranges in this zone that have
1752 * already been initialized. We don't need to do anything with them
1753 * so we just need to flush them out of the system.
1754 */
1755 for_each_free_mem_pfn_range_in_zone(j, zone, spfn, epfn) {
1756 if (*epfn <= first_init_pfn)
1757 continue;
1758 if (*spfn < first_init_pfn)
1759 *spfn = first_init_pfn;
1760 *i = j;
1761 return true;
1762 }
1763
1764 return false;
1765}
1766
1767/*
1768 * Initialize and free pages. We do it in two loops: first we initialize
1769 * struct page, then free to buddy allocator, because while we are
1770 * freeing pages we can access pages that are ahead (computing buddy
1771 * page in __free_one_page()).
1772 *
1773 * In order to try and keep some memory in the cache we have the loop
1774 * broken along max page order boundaries. This way we will not cause
1775 * any issues with the buddy page computation.
1776 */
1777static unsigned long __init
1778deferred_init_maxorder(u64 *i, struct zone *zone, unsigned long *start_pfn,
1779 unsigned long *end_pfn)
1780{
1781 unsigned long mo_pfn = ALIGN(*start_pfn + 1, MAX_ORDER_NR_PAGES);
1782 unsigned long spfn = *start_pfn, epfn = *end_pfn;
1783 unsigned long nr_pages = 0;
1784 u64 j = *i;
1785
1786 /* First we loop through and initialize the page values */
1787 for_each_free_mem_pfn_range_in_zone_from(j, zone, start_pfn, end_pfn) {
1788 unsigned long t;
1789
1790 if (mo_pfn <= *start_pfn)
1791 break;
1792
1793 t = min(mo_pfn, *end_pfn);
1794 nr_pages += deferred_init_pages(zone, *start_pfn, t);
1795
1796 if (mo_pfn < *end_pfn) {
1797 *start_pfn = mo_pfn;
1798 break;
1799 }
1800 }
1801
1802 /* Reset values and now loop through freeing pages as needed */
1803 swap(j, *i);
1804
1805 for_each_free_mem_pfn_range_in_zone_from(j, zone, &spfn, &epfn) {
1806 unsigned long t;
1807
1808 if (mo_pfn <= spfn)
1809 break;
1810
1811 t = min(mo_pfn, epfn);
1812 deferred_free_pages(spfn, t);
1813
1814 if (mo_pfn <= epfn)
1815 break;
1816 }
1817
1818 return nr_pages;
1819}
1820
1821static void __init
1822deferred_init_memmap_chunk(unsigned long start_pfn, unsigned long end_pfn,
1823 void *arg)
1824{
1825 unsigned long spfn, epfn;
1826 struct zone *zone = arg;
1827 u64 i;
1828
1829 deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, start_pfn);
1830
1831 /*
1832 * Initialize and free pages in MAX_ORDER sized increments so that we
1833 * can avoid introducing any issues with the buddy allocator.
1834 */
1835 while (spfn < end_pfn) {
1836 deferred_init_maxorder(&i, zone, &spfn, &epfn);
1837 cond_resched();
1838 }
1839}
1840
1841/* An arch may override for more concurrency. */
1842__weak int __init
1843deferred_page_init_max_threads(const struct cpumask *node_cpumask)
1844{
1845 return 1;
1846}
1847
1848/* Initialise remaining memory on a node */
1849static int __init deferred_init_memmap(void *data)
1850{
1851 pg_data_t *pgdat = data;
1852 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1853 unsigned long spfn = 0, epfn = 0;
1854 unsigned long first_init_pfn, flags;
1855 unsigned long start = jiffies;
1856 struct zone *zone;
1857 int zid, max_threads;
1858 u64 i;
1859
1860 /* Bind memory initialisation thread to a local node if possible */
1861 if (!cpumask_empty(cpumask))
1862 set_cpus_allowed_ptr(current, cpumask);
1863
1864 pgdat_resize_lock(pgdat, &flags);
1865 first_init_pfn = pgdat->first_deferred_pfn;
1866 if (first_init_pfn == ULONG_MAX) {
1867 pgdat_resize_unlock(pgdat, &flags);
1868 pgdat_init_report_one_done();
1869 return 0;
1870 }
1871
1872 /* Sanity check boundaries */
1873 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1874 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1875 pgdat->first_deferred_pfn = ULONG_MAX;
1876
1877 /*
1878 * Once we unlock here, the zone cannot be grown anymore, thus if an
1879 * interrupt thread must allocate this early in boot, zone must be
1880 * pre-grown prior to start of deferred page initialization.
1881 */
1882 pgdat_resize_unlock(pgdat, &flags);
1883
1884 /* Only the highest zone is deferred so find it */
1885 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1886 zone = pgdat->node_zones + zid;
1887 if (first_init_pfn < zone_end_pfn(zone))
1888 break;
1889 }
1890
1891 /* If the zone is empty somebody else may have cleared out the zone */
1892 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1893 first_init_pfn))
1894 goto zone_empty;
1895
1896 max_threads = deferred_page_init_max_threads(cpumask);
1897
1898 while (spfn < epfn) {
1899 unsigned long epfn_align = ALIGN(epfn, PAGES_PER_SECTION);
1900 struct padata_mt_job job = {
1901 .thread_fn = deferred_init_memmap_chunk,
1902 .fn_arg = zone,
1903 .start = spfn,
1904 .size = epfn_align - spfn,
1905 .align = PAGES_PER_SECTION,
1906 .min_chunk = PAGES_PER_SECTION,
1907 .max_threads = max_threads,
1908 };
1909
1910 padata_do_multithreaded(&job);
1911 deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1912 epfn_align);
1913 }
1914zone_empty:
1915 /* Sanity check that the next zone really is unpopulated */
1916 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1917
1918 pr_info("node %d deferred pages initialised in %ums\n",
1919 pgdat->node_id, jiffies_to_msecs(jiffies - start));
1920
1921 pgdat_init_report_one_done();
1922 return 0;
1923}
1924
1925/*
1926 * If this zone has deferred pages, try to grow it by initializing enough
1927 * deferred pages to satisfy the allocation specified by order, rounded up to
1928 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1929 * of SECTION_SIZE bytes by initializing struct pages in increments of
1930 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1931 *
1932 * Return true when zone was grown, otherwise return false. We return true even
1933 * when we grow less than requested, to let the caller decide if there are
1934 * enough pages to satisfy the allocation.
1935 *
1936 * Note: We use noinline because this function is needed only during boot, and
1937 * it is called from a __ref function _deferred_grow_zone. This way we are
1938 * making sure that it is not inlined into permanent text section.
1939 */
1940static noinline bool __init
1941deferred_grow_zone(struct zone *zone, unsigned int order)
1942{
1943 unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
1944 pg_data_t *pgdat = zone->zone_pgdat;
1945 unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
1946 unsigned long spfn, epfn, flags;
1947 unsigned long nr_pages = 0;
1948 u64 i;
1949
1950 /* Only the last zone may have deferred pages */
1951 if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))
1952 return false;
1953
1954 pgdat_resize_lock(pgdat, &flags);
1955
1956 /*
1957 * If someone grew this zone while we were waiting for spinlock, return
1958 * true, as there might be enough pages already.
1959 */
1960 if (first_deferred_pfn != pgdat->first_deferred_pfn) {
1961 pgdat_resize_unlock(pgdat, &flags);
1962 return true;
1963 }
1964
1965 /* If the zone is empty somebody else may have cleared out the zone */
1966 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1967 first_deferred_pfn)) {
1968 pgdat->first_deferred_pfn = ULONG_MAX;
1969 pgdat_resize_unlock(pgdat, &flags);
1970 /* Retry only once. */
1971 return first_deferred_pfn != ULONG_MAX;
1972 }
1973
1974 /*
1975 * Initialize and free pages in MAX_ORDER sized increments so
1976 * that we can avoid introducing any issues with the buddy
1977 * allocator.
1978 */
1979 while (spfn < epfn) {
1980 /* update our first deferred PFN for this section */
1981 first_deferred_pfn = spfn;
1982
1983 nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn);
1984 touch_nmi_watchdog();
1985
1986 /* We should only stop along section boundaries */
1987 if ((first_deferred_pfn ^ spfn) < PAGES_PER_SECTION)
1988 continue;
1989
1990 /* If our quota has been met we can stop here */
1991 if (nr_pages >= nr_pages_needed)
1992 break;
1993 }
1994
1995 pgdat->first_deferred_pfn = spfn;
1996 pgdat_resize_unlock(pgdat, &flags);
1997
1998 return nr_pages > 0;
1999}
2000
2001/*
2002 * deferred_grow_zone() is __init, but it is called from
2003 * get_page_from_freelist() during early boot until deferred_pages permanently
2004 * disables this call. This is why we have refdata wrapper to avoid warning,
2005 * and to ensure that the function body gets unloaded.
2006 */
2007static bool __ref
2008_deferred_grow_zone(struct zone *zone, unsigned int order)
2009{
2010 return deferred_grow_zone(zone, order);
2011}
2012
2013#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2014
2015void __init page_alloc_init_late(void)
2016{
2017 struct zone *zone;
2018 int nid;
2019
2020#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2021
2022 /* There will be num_node_state(N_MEMORY) threads */
2023 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
2024 for_each_node_state(nid, N_MEMORY) {
2025 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
2026 }
2027
2028 /* Block until all are initialised */
2029 wait_for_completion(&pgdat_init_all_done_comp);
2030
2031 /*
2032 * The number of managed pages has changed due to the initialisation
2033 * so the pcpu batch and high limits needs to be updated or the limits
2034 * will be artificially small.
2035 */
2036 for_each_populated_zone(zone)
2037 zone_pcp_update(zone);
2038
2039 /*
2040 * We initialized the rest of the deferred pages. Permanently disable
2041 * on-demand struct page initialization.
2042 */
2043 static_branch_disable(&deferred_pages);
2044
2045 /* Reinit limits that are based on free pages after the kernel is up */
2046 files_maxfiles_init();
2047#endif
2048
2049 /* Discard memblock private memory */
2050 memblock_discard();
2051
2052 for_each_node_state(nid, N_MEMORY)
2053 shuffle_free_memory(NODE_DATA(nid));
2054
2055 for_each_populated_zone(zone)
2056 set_zone_contiguous(zone);
2057}
2058
2059#ifdef CONFIG_CMA
2060/* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2061void __init init_cma_reserved_pageblock(struct page *page)
2062{
2063 unsigned i = pageblock_nr_pages;
2064 struct page *p = page;
2065
2066 do {
2067 __ClearPageReserved(p);
2068 set_page_count(p, 0);
2069 } while (++p, --i);
2070
2071 set_pageblock_migratetype(page, MIGRATE_CMA);
2072
2073 if (pageblock_order >= MAX_ORDER) {
2074 i = pageblock_nr_pages;
2075 p = page;
2076 do {
2077 set_page_refcounted(p);
2078 __free_pages(p, MAX_ORDER - 1);
2079 p += MAX_ORDER_NR_PAGES;
2080 } while (i -= MAX_ORDER_NR_PAGES);
2081 } else {
2082 set_page_refcounted(page);
2083 __free_pages(page, pageblock_order);
2084 }
2085
2086 adjust_managed_page_count(page, pageblock_nr_pages);
2087}
2088#endif
2089
2090/*
2091 * The order of subdivision here is critical for the IO subsystem.
2092 * Please do not alter this order without good reasons and regression
2093 * testing. Specifically, as large blocks of memory are subdivided,
2094 * the order in which smaller blocks are delivered depends on the order
2095 * they're subdivided in this function. This is the primary factor
2096 * influencing the order in which pages are delivered to the IO
2097 * subsystem according to empirical testing, and this is also justified
2098 * by considering the behavior of a buddy system containing a single
2099 * large block of memory acted on by a series of small allocations.
2100 * This behavior is a critical factor in sglist merging's success.
2101 *
2102 * -- nyc
2103 */
2104static inline void expand(struct zone *zone, struct page *page,
2105 int low, int high, int migratetype)
2106{
2107 unsigned long size = 1 << high;
2108
2109 while (high > low) {
2110 high--;
2111 size >>= 1;
2112 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
2113
2114 /*
2115 * Mark as guard pages (or page), that will allow to
2116 * merge back to allocator when buddy will be freed.
2117 * Corresponding page table entries will not be touched,
2118 * pages will stay not present in virtual address space
2119 */
2120 if (set_page_guard(zone, &page[size], high, migratetype))
2121 continue;
2122
2123 add_to_free_list(&page[size], zone, high, migratetype);
2124 set_page_order(&page[size], high);
2125 }
2126}
2127
2128static void check_new_page_bad(struct page *page)
2129{
2130 if (unlikely(page->flags & __PG_HWPOISON)) {
2131 /* Don't complain about hwpoisoned pages */
2132 page_mapcount_reset(page); /* remove PageBuddy */
2133 return;
2134 }
2135
2136 bad_page(page,
2137 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
2138}
2139
2140/*
2141 * This page is about to be returned from the page allocator
2142 */
2143static inline int check_new_page(struct page *page)
2144{
2145 if (likely(page_expected_state(page,
2146 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
2147 return 0;
2148
2149 check_new_page_bad(page);
2150 return 1;
2151}
2152
2153static inline bool free_pages_prezeroed(void)
2154{
2155 return (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
2156 page_poisoning_enabled()) || want_init_on_free();
2157}
2158
2159#ifdef CONFIG_DEBUG_VM
2160/*
2161 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2162 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2163 * also checked when pcp lists are refilled from the free lists.
2164 */
2165static inline bool check_pcp_refill(struct page *page)
2166{
2167 if (debug_pagealloc_enabled_static())
2168 return check_new_page(page);
2169 else
2170 return false;
2171}
2172
2173static inline bool check_new_pcp(struct page *page)
2174{
2175 return check_new_page(page);
2176}
2177#else
2178/*
2179 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2180 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2181 * enabled, they are also checked when being allocated from the pcp lists.
2182 */
2183static inline bool check_pcp_refill(struct page *page)
2184{
2185 return check_new_page(page);
2186}
2187static inline bool check_new_pcp(struct page *page)
2188{
2189 if (debug_pagealloc_enabled_static())
2190 return check_new_page(page);
2191 else
2192 return false;
2193}
2194#endif /* CONFIG_DEBUG_VM */
2195
2196static bool check_new_pages(struct page *page, unsigned int order)
2197{
2198 int i;
2199 for (i = 0; i < (1 << order); i++) {
2200 struct page *p = page + i;
2201
2202 if (unlikely(check_new_page(p)))
2203 return true;
2204 }
2205
2206 return false;
2207}
2208
2209inline void post_alloc_hook(struct page *page, unsigned int order,
2210 gfp_t gfp_flags)
2211{
2212 set_page_private(page, 0);
2213 set_page_refcounted(page);
2214
2215 arch_alloc_page(page, order);
2216 if (debug_pagealloc_enabled_static())
2217 kernel_map_pages(page, 1 << order, 1);
2218 kasan_alloc_pages(page, order);
2219 kernel_poison_pages(page, 1 << order, 1);
2220 set_page_owner(page, order, gfp_flags);
2221}
2222
2223static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
2224 unsigned int alloc_flags)
2225{
2226 post_alloc_hook(page, order, gfp_flags);
2227
2228 if (!free_pages_prezeroed() && want_init_on_alloc(gfp_flags))
2229 kernel_init_free_pages(page, 1 << order);
2230
2231 if (order && (gfp_flags & __GFP_COMP))
2232 prep_compound_page(page, order);
2233
2234 /*
2235 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2236 * allocate the page. The expectation is that the caller is taking
2237 * steps that will free more memory. The caller should avoid the page
2238 * being used for !PFMEMALLOC purposes.
2239 */
2240 if (alloc_flags & ALLOC_NO_WATERMARKS)
2241 set_page_pfmemalloc(page);
2242 else
2243 clear_page_pfmemalloc(page);
2244}
2245
2246/*
2247 * Go through the free lists for the given migratetype and remove
2248 * the smallest available page from the freelists
2249 */
2250static __always_inline
2251struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
2252 int migratetype)
2253{
2254 unsigned int current_order;
2255 struct free_area *area;
2256 struct page *page;
2257
2258 /* Find a page of the appropriate size in the preferred list */
2259 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
2260 area = &(zone->free_area[current_order]);
2261 page = get_page_from_free_area(area, migratetype);
2262 if (!page)
2263 continue;
2264 del_page_from_free_list(page, zone, current_order);
2265 expand(zone, page, order, current_order, migratetype);
2266 set_pcppage_migratetype(page, migratetype);
2267 return page;
2268 }
2269
2270 return NULL;
2271}
2272
2273
2274/*
2275 * This array describes the order lists are fallen back to when
2276 * the free lists for the desirable migrate type are depleted
2277 */
2278static int fallbacks[MIGRATE_TYPES][3] = {
2279 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2280 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
2281 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2282#ifdef CONFIG_CMA
2283 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
2284#endif
2285#ifdef CONFIG_MEMORY_ISOLATION
2286 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
2287#endif
2288};
2289
2290#ifdef CONFIG_CMA
2291static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2292 unsigned int order)
2293{
2294 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
2295}
2296#else
2297static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2298 unsigned int order) { return NULL; }
2299#endif
2300
2301/*
2302 * Move the free pages in a range to the free lists of the requested type.
2303 * Note that start_page and end_pages are not aligned on a pageblock
2304 * boundary. If alignment is required, use move_freepages_block()
2305 */
2306static int move_freepages(struct zone *zone,
2307 struct page *start_page, struct page *end_page,
2308 int migratetype, int *num_movable)
2309{
2310 struct page *page;
2311 unsigned int order;
2312 int pages_moved = 0;
2313
2314 for (page = start_page; page <= end_page;) {
2315 if (!pfn_valid_within(page_to_pfn(page))) {
2316 page++;
2317 continue;
2318 }
2319
2320 if (!PageBuddy(page)) {
2321 /*
2322 * We assume that pages that could be isolated for
2323 * migration are movable. But we don't actually try
2324 * isolating, as that would be expensive.
2325 */
2326 if (num_movable &&
2327 (PageLRU(page) || __PageMovable(page)))
2328 (*num_movable)++;
2329
2330 page++;
2331 continue;
2332 }
2333
2334 /* Make sure we are not inadvertently changing nodes */
2335 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
2336 VM_BUG_ON_PAGE(page_zone(page) != zone, page);
2337
2338 order = page_order(page);
2339 move_to_free_list(page, zone, order, migratetype);
2340 page += 1 << order;
2341 pages_moved += 1 << order;
2342 }
2343
2344 return pages_moved;
2345}
2346
2347int move_freepages_block(struct zone *zone, struct page *page,
2348 int migratetype, int *num_movable)
2349{
2350 unsigned long start_pfn, end_pfn;
2351 struct page *start_page, *end_page;
2352
2353 if (num_movable)
2354 *num_movable = 0;
2355
2356 start_pfn = page_to_pfn(page);
2357 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
2358 start_page = pfn_to_page(start_pfn);
2359 end_page = start_page + pageblock_nr_pages - 1;
2360 end_pfn = start_pfn + pageblock_nr_pages - 1;
2361
2362 /* Do not cross zone boundaries */
2363 if (!zone_spans_pfn(zone, start_pfn))
2364 start_page = page;
2365 if (!zone_spans_pfn(zone, end_pfn))
2366 return 0;
2367
2368 return move_freepages(zone, start_page, end_page, migratetype,
2369 num_movable);
2370}
2371
2372static void change_pageblock_range(struct page *pageblock_page,
2373 int start_order, int migratetype)
2374{
2375 int nr_pageblocks = 1 << (start_order - pageblock_order);
2376
2377 while (nr_pageblocks--) {
2378 set_pageblock_migratetype(pageblock_page, migratetype);
2379 pageblock_page += pageblock_nr_pages;
2380 }
2381}
2382
2383/*
2384 * When we are falling back to another migratetype during allocation, try to
2385 * steal extra free pages from the same pageblocks to satisfy further
2386 * allocations, instead of polluting multiple pageblocks.
2387 *
2388 * If we are stealing a relatively large buddy page, it is likely there will
2389 * be more free pages in the pageblock, so try to steal them all. For
2390 * reclaimable and unmovable allocations, we steal regardless of page size,
2391 * as fragmentation caused by those allocations polluting movable pageblocks
2392 * is worse than movable allocations stealing from unmovable and reclaimable
2393 * pageblocks.
2394 */
2395static bool can_steal_fallback(unsigned int order, int start_mt)
2396{
2397 /*
2398 * Leaving this order check is intended, although there is
2399 * relaxed order check in next check. The reason is that
2400 * we can actually steal whole pageblock if this condition met,
2401 * but, below check doesn't guarantee it and that is just heuristic
2402 * so could be changed anytime.
2403 */
2404 if (order >= pageblock_order)
2405 return true;
2406
2407 if (order >= pageblock_order / 2 ||
2408 start_mt == MIGRATE_RECLAIMABLE ||
2409 start_mt == MIGRATE_UNMOVABLE ||
2410 page_group_by_mobility_disabled)
2411 return true;
2412
2413 return false;
2414}
2415
2416static inline void boost_watermark(struct zone *zone)
2417{
2418 unsigned long max_boost;
2419
2420 if (!watermark_boost_factor)
2421 return;
2422 /*
2423 * Don't bother in zones that are unlikely to produce results.
2424 * On small machines, including kdump capture kernels running
2425 * in a small area, boosting the watermark can cause an out of
2426 * memory situation immediately.
2427 */
2428 if ((pageblock_nr_pages * 4) > zone_managed_pages(zone))
2429 return;
2430
2431 max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
2432 watermark_boost_factor, 10000);
2433
2434 /*
2435 * high watermark may be uninitialised if fragmentation occurs
2436 * very early in boot so do not boost. We do not fall
2437 * through and boost by pageblock_nr_pages as failing
2438 * allocations that early means that reclaim is not going
2439 * to help and it may even be impossible to reclaim the
2440 * boosted watermark resulting in a hang.
2441 */
2442 if (!max_boost)
2443 return;
2444
2445 max_boost = max(pageblock_nr_pages, max_boost);
2446
2447 zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages,
2448 max_boost);
2449}
2450
2451/*
2452 * This function implements actual steal behaviour. If order is large enough,
2453 * we can steal whole pageblock. If not, we first move freepages in this
2454 * pageblock to our migratetype and determine how many already-allocated pages
2455 * are there in the pageblock with a compatible migratetype. If at least half
2456 * of pages are free or compatible, we can change migratetype of the pageblock
2457 * itself, so pages freed in the future will be put on the correct free list.
2458 */
2459static void steal_suitable_fallback(struct zone *zone, struct page *page,
2460 unsigned int alloc_flags, int start_type, bool whole_block)
2461{
2462 unsigned int current_order = page_order(page);
2463 int free_pages, movable_pages, alike_pages;
2464 int old_block_type;
2465
2466 old_block_type = get_pageblock_migratetype(page);
2467
2468 /*
2469 * This can happen due to races and we want to prevent broken
2470 * highatomic accounting.
2471 */
2472 if (is_migrate_highatomic(old_block_type))
2473 goto single_page;
2474
2475 /* Take ownership for orders >= pageblock_order */
2476 if (current_order >= pageblock_order) {
2477 change_pageblock_range(page, current_order, start_type);
2478 goto single_page;
2479 }
2480
2481 /*
2482 * Boost watermarks to increase reclaim pressure to reduce the
2483 * likelihood of future fallbacks. Wake kswapd now as the node
2484 * may be balanced overall and kswapd will not wake naturally.
2485 */
2486 boost_watermark(zone);
2487 if (alloc_flags & ALLOC_KSWAPD)
2488 set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
2489
2490 /* We are not allowed to try stealing from the whole block */
2491 if (!whole_block)
2492 goto single_page;
2493
2494 free_pages = move_freepages_block(zone, page, start_type,
2495 &movable_pages);
2496 /*
2497 * Determine how many pages are compatible with our allocation.
2498 * For movable allocation, it's the number of movable pages which
2499 * we just obtained. For other types it's a bit more tricky.
2500 */
2501 if (start_type == MIGRATE_MOVABLE) {
2502 alike_pages = movable_pages;
2503 } else {
2504 /*
2505 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2506 * to MOVABLE pageblock, consider all non-movable pages as
2507 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2508 * vice versa, be conservative since we can't distinguish the
2509 * exact migratetype of non-movable pages.
2510 */
2511 if (old_block_type == MIGRATE_MOVABLE)
2512 alike_pages = pageblock_nr_pages
2513 - (free_pages + movable_pages);
2514 else
2515 alike_pages = 0;
2516 }
2517
2518 /* moving whole block can fail due to zone boundary conditions */
2519 if (!free_pages)
2520 goto single_page;
2521
2522 /*
2523 * If a sufficient number of pages in the block are either free or of
2524 * comparable migratability as our allocation, claim the whole block.
2525 */
2526 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2527 page_group_by_mobility_disabled)
2528 set_pageblock_migratetype(page, start_type);
2529
2530 return;
2531
2532single_page:
2533 move_to_free_list(page, zone, current_order, start_type);
2534}
2535
2536/*
2537 * Check whether there is a suitable fallback freepage with requested order.
2538 * If only_stealable is true, this function returns fallback_mt only if
2539 * we can steal other freepages all together. This would help to reduce
2540 * fragmentation due to mixed migratetype pages in one pageblock.
2541 */
2542int find_suitable_fallback(struct free_area *area, unsigned int order,
2543 int migratetype, bool only_stealable, bool *can_steal)
2544{
2545 int i;
2546 int fallback_mt;
2547
2548 if (area->nr_free == 0)
2549 return -1;
2550
2551 *can_steal = false;
2552 for (i = 0;; i++) {
2553 fallback_mt = fallbacks[migratetype][i];
2554 if (fallback_mt == MIGRATE_TYPES)
2555 break;
2556
2557 if (free_area_empty(area, fallback_mt))
2558 continue;
2559
2560 if (can_steal_fallback(order, migratetype))
2561 *can_steal = true;
2562
2563 if (!only_stealable)
2564 return fallback_mt;
2565
2566 if (*can_steal)
2567 return fallback_mt;
2568 }
2569
2570 return -1;
2571}
2572
2573/*
2574 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2575 * there are no empty page blocks that contain a page with a suitable order
2576 */
2577static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2578 unsigned int alloc_order)
2579{
2580 int mt;
2581 unsigned long max_managed, flags;
2582
2583 /*
2584 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2585 * Check is race-prone but harmless.
2586 */
2587 max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;
2588 if (zone->nr_reserved_highatomic >= max_managed)
2589 return;
2590
2591 spin_lock_irqsave(&zone->lock, flags);
2592
2593 /* Recheck the nr_reserved_highatomic limit under the lock */
2594 if (zone->nr_reserved_highatomic >= max_managed)
2595 goto out_unlock;
2596
2597 /* Yoink! */
2598 mt = get_pageblock_migratetype(page);
2599 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2600 && !is_migrate_cma(mt)) {
2601 zone->nr_reserved_highatomic += pageblock_nr_pages;
2602 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2603 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2604 }
2605
2606out_unlock:
2607 spin_unlock_irqrestore(&zone->lock, flags);
2608}
2609
2610/*
2611 * Used when an allocation is about to fail under memory pressure. This
2612 * potentially hurts the reliability of high-order allocations when under
2613 * intense memory pressure but failed atomic allocations should be easier
2614 * to recover from than an OOM.
2615 *
2616 * If @force is true, try to unreserve a pageblock even though highatomic
2617 * pageblock is exhausted.
2618 */
2619static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2620 bool force)
2621{
2622 struct zonelist *zonelist = ac->zonelist;
2623 unsigned long flags;
2624 struct zoneref *z;
2625 struct zone *zone;
2626 struct page *page;
2627 int order;
2628 bool ret;
2629
2630 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
2631 ac->nodemask) {
2632 /*
2633 * Preserve at least one pageblock unless memory pressure
2634 * is really high.
2635 */
2636 if (!force && zone->nr_reserved_highatomic <=
2637 pageblock_nr_pages)
2638 continue;
2639
2640 spin_lock_irqsave(&zone->lock, flags);
2641 for (order = 0; order < MAX_ORDER; order++) {
2642 struct free_area *area = &(zone->free_area[order]);
2643
2644 page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
2645 if (!page)
2646 continue;
2647
2648 /*
2649 * In page freeing path, migratetype change is racy so
2650 * we can counter several free pages in a pageblock
2651 * in this loop althoug we changed the pageblock type
2652 * from highatomic to ac->migratetype. So we should
2653 * adjust the count once.
2654 */
2655 if (is_migrate_highatomic_page(page)) {
2656 /*
2657 * It should never happen but changes to
2658 * locking could inadvertently allow a per-cpu
2659 * drain to add pages to MIGRATE_HIGHATOMIC
2660 * while unreserving so be safe and watch for
2661 * underflows.
2662 */
2663 zone->nr_reserved_highatomic -= min(
2664 pageblock_nr_pages,
2665 zone->nr_reserved_highatomic);
2666 }
2667
2668 /*
2669 * Convert to ac->migratetype and avoid the normal
2670 * pageblock stealing heuristics. Minimally, the caller
2671 * is doing the work and needs the pages. More
2672 * importantly, if the block was always converted to
2673 * MIGRATE_UNMOVABLE or another type then the number
2674 * of pageblocks that cannot be completely freed
2675 * may increase.
2676 */
2677 set_pageblock_migratetype(page, ac->migratetype);
2678 ret = move_freepages_block(zone, page, ac->migratetype,
2679 NULL);
2680 if (ret) {
2681 spin_unlock_irqrestore(&zone->lock, flags);
2682 return ret;
2683 }
2684 }
2685 spin_unlock_irqrestore(&zone->lock, flags);
2686 }
2687
2688 return false;
2689}
2690
2691/*
2692 * Try finding a free buddy page on the fallback list and put it on the free
2693 * list of requested migratetype, possibly along with other pages from the same
2694 * block, depending on fragmentation avoidance heuristics. Returns true if
2695 * fallback was found so that __rmqueue_smallest() can grab it.
2696 *
2697 * The use of signed ints for order and current_order is a deliberate
2698 * deviation from the rest of this file, to make the for loop
2699 * condition simpler.
2700 */
2701static __always_inline bool
2702__rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
2703 unsigned int alloc_flags)
2704{
2705 struct free_area *area;
2706 int current_order;
2707 int min_order = order;
2708 struct page *page;
2709 int fallback_mt;
2710 bool can_steal;
2711
2712 /*
2713 * Do not steal pages from freelists belonging to other pageblocks
2714 * i.e. orders < pageblock_order. If there are no local zones free,
2715 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2716 */
2717 if (alloc_flags & ALLOC_NOFRAGMENT)
2718 min_order = pageblock_order;
2719
2720 /*
2721 * Find the largest available free page in the other list. This roughly
2722 * approximates finding the pageblock with the most free pages, which
2723 * would be too costly to do exactly.
2724 */
2725 for (current_order = MAX_ORDER - 1; current_order >= min_order;
2726 --current_order) {
2727 area = &(zone->free_area[current_order]);
2728 fallback_mt = find_suitable_fallback(area, current_order,
2729 start_migratetype, false, &can_steal);
2730 if (fallback_mt == -1)
2731 continue;
2732
2733 /*
2734 * We cannot steal all free pages from the pageblock and the
2735 * requested migratetype is movable. In that case it's better to
2736 * steal and split the smallest available page instead of the
2737 * largest available page, because even if the next movable
2738 * allocation falls back into a different pageblock than this
2739 * one, it won't cause permanent fragmentation.
2740 */
2741 if (!can_steal && start_migratetype == MIGRATE_MOVABLE
2742 && current_order > order)
2743 goto find_smallest;
2744
2745 goto do_steal;
2746 }
2747
2748 return false;
2749
2750find_smallest:
2751 for (current_order = order; current_order < MAX_ORDER;
2752 current_order++) {
2753 area = &(zone->free_area[current_order]);
2754 fallback_mt = find_suitable_fallback(area, current_order,
2755 start_migratetype, false, &can_steal);
2756 if (fallback_mt != -1)
2757 break;
2758 }
2759
2760 /*
2761 * This should not happen - we already found a suitable fallback
2762 * when looking for the largest page.
2763 */
2764 VM_BUG_ON(current_order == MAX_ORDER);
2765
2766do_steal:
2767 page = get_page_from_free_area(area, fallback_mt);
2768
2769 steal_suitable_fallback(zone, page, alloc_flags, start_migratetype,
2770 can_steal);
2771
2772 trace_mm_page_alloc_extfrag(page, order, current_order,
2773 start_migratetype, fallback_mt);
2774
2775 return true;
2776
2777}
2778
2779/*
2780 * Do the hard work of removing an element from the buddy allocator.
2781 * Call me with the zone->lock already held.
2782 */
2783static __always_inline struct page *
2784__rmqueue(struct zone *zone, unsigned int order, int migratetype,
2785 unsigned int alloc_flags)
2786{
2787 struct page *page;
2788
2789#ifdef CONFIG_CMA
2790 /*
2791 * Balance movable allocations between regular and CMA areas by
2792 * allocating from CMA when over half of the zone's free memory
2793 * is in the CMA area.
2794 */
2795 if (alloc_flags & ALLOC_CMA &&
2796 zone_page_state(zone, NR_FREE_CMA_PAGES) >
2797 zone_page_state(zone, NR_FREE_PAGES) / 2) {
2798 page = __rmqueue_cma_fallback(zone, order);
2799 if (page)
2800 return page;
2801 }
2802#endif
2803retry:
2804 page = __rmqueue_smallest(zone, order, migratetype);
2805 if (unlikely(!page)) {
2806 if (alloc_flags & ALLOC_CMA)
2807 page = __rmqueue_cma_fallback(zone, order);
2808
2809 if (!page && __rmqueue_fallback(zone, order, migratetype,
2810 alloc_flags))
2811 goto retry;
2812 }
2813
2814 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2815 return page;
2816}
2817
2818/*
2819 * Obtain a specified number of elements from the buddy allocator, all under
2820 * a single hold of the lock, for efficiency. Add them to the supplied list.
2821 * Returns the number of new pages which were placed at *list.
2822 */
2823static int rmqueue_bulk(struct zone *zone, unsigned int order,
2824 unsigned long count, struct list_head *list,
2825 int migratetype, unsigned int alloc_flags)
2826{
2827 int i, alloced = 0;
2828
2829 spin_lock(&zone->lock);
2830 for (i = 0; i < count; ++i) {
2831 struct page *page = __rmqueue(zone, order, migratetype,
2832 alloc_flags);
2833 if (unlikely(page == NULL))
2834 break;
2835
2836 if (unlikely(check_pcp_refill(page)))
2837 continue;
2838
2839 /*
2840 * Split buddy pages returned by expand() are received here in
2841 * physical page order. The page is added to the tail of
2842 * caller's list. From the callers perspective, the linked list
2843 * is ordered by page number under some conditions. This is
2844 * useful for IO devices that can forward direction from the
2845 * head, thus also in the physical page order. This is useful
2846 * for IO devices that can merge IO requests if the physical
2847 * pages are ordered properly.
2848 */
2849 list_add_tail(&page->lru, list);
2850 alloced++;
2851 if (is_migrate_cma(get_pcppage_migratetype(page)))
2852 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2853 -(1 << order));
2854 }
2855
2856 /*
2857 * i pages were removed from the buddy list even if some leak due
2858 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2859 * on i. Do not confuse with 'alloced' which is the number of
2860 * pages added to the pcp list.
2861 */
2862 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2863 spin_unlock(&zone->lock);
2864 return alloced;
2865}
2866
2867#ifdef CONFIG_NUMA
2868/*
2869 * Called from the vmstat counter updater to drain pagesets of this
2870 * currently executing processor on remote nodes after they have
2871 * expired.
2872 *
2873 * Note that this function must be called with the thread pinned to
2874 * a single processor.
2875 */
2876void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2877{
2878 unsigned long flags;
2879 int to_drain, batch;
2880
2881 local_irq_save(flags);
2882 batch = READ_ONCE(pcp->batch);
2883 to_drain = min(pcp->count, batch);
2884 if (to_drain > 0)
2885 free_pcppages_bulk(zone, to_drain, pcp);
2886 local_irq_restore(flags);
2887}
2888#endif
2889
2890/*
2891 * Drain pcplists of the indicated processor and zone.
2892 *
2893 * The processor must either be the current processor and the
2894 * thread pinned to the current processor or a processor that
2895 * is not online.
2896 */
2897static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2898{
2899 unsigned long flags;
2900 struct per_cpu_pageset *pset;
2901 struct per_cpu_pages *pcp;
2902
2903 local_irq_save(flags);
2904 pset = per_cpu_ptr(zone->pageset, cpu);
2905
2906 pcp = &pset->pcp;
2907 if (pcp->count)
2908 free_pcppages_bulk(zone, pcp->count, pcp);
2909 local_irq_restore(flags);
2910}
2911
2912/*
2913 * Drain pcplists of all zones on the indicated processor.
2914 *
2915 * The processor must either be the current processor and the
2916 * thread pinned to the current processor or a processor that
2917 * is not online.
2918 */
2919static void drain_pages(unsigned int cpu)
2920{
2921 struct zone *zone;
2922
2923 for_each_populated_zone(zone) {
2924 drain_pages_zone(cpu, zone);
2925 }
2926}
2927
2928/*
2929 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2930 *
2931 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2932 * the single zone's pages.
2933 */
2934void drain_local_pages(struct zone *zone)
2935{
2936 int cpu = smp_processor_id();
2937
2938 if (zone)
2939 drain_pages_zone(cpu, zone);
2940 else
2941 drain_pages(cpu);
2942}
2943
2944static void drain_local_pages_wq(struct work_struct *work)
2945{
2946 struct pcpu_drain *drain;
2947
2948 drain = container_of(work, struct pcpu_drain, work);
2949
2950 /*
2951 * drain_all_pages doesn't use proper cpu hotplug protection so
2952 * we can race with cpu offline when the WQ can move this from
2953 * a cpu pinned worker to an unbound one. We can operate on a different
2954 * cpu which is allright but we also have to make sure to not move to
2955 * a different one.
2956 */
2957 preempt_disable();
2958 drain_local_pages(drain->zone);
2959 preempt_enable();
2960}
2961
2962/*
2963 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2964 *
2965 * When zone parameter is non-NULL, spill just the single zone's pages.
2966 *
2967 * Note that this can be extremely slow as the draining happens in a workqueue.
2968 */
2969void drain_all_pages(struct zone *zone)
2970{
2971 int cpu;
2972
2973 /*
2974 * Allocate in the BSS so we wont require allocation in
2975 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2976 */
2977 static cpumask_t cpus_with_pcps;
2978
2979 /*
2980 * Make sure nobody triggers this path before mm_percpu_wq is fully
2981 * initialized.
2982 */
2983 if (WARN_ON_ONCE(!mm_percpu_wq))
2984 return;
2985
2986 /*
2987 * Do not drain if one is already in progress unless it's specific to
2988 * a zone. Such callers are primarily CMA and memory hotplug and need
2989 * the drain to be complete when the call returns.
2990 */
2991 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
2992 if (!zone)
2993 return;
2994 mutex_lock(&pcpu_drain_mutex);
2995 }
2996
2997 /*
2998 * We don't care about racing with CPU hotplug event
2999 * as offline notification will cause the notified
3000 * cpu to drain that CPU pcps and on_each_cpu_mask
3001 * disables preemption as part of its processing
3002 */
3003 for_each_online_cpu(cpu) {
3004 struct per_cpu_pageset *pcp;
3005 struct zone *z;
3006 bool has_pcps = false;
3007
3008 if (zone) {
3009 pcp = per_cpu_ptr(zone->pageset, cpu);
3010 if (pcp->pcp.count)
3011 has_pcps = true;
3012 } else {
3013 for_each_populated_zone(z) {
3014 pcp = per_cpu_ptr(z->pageset, cpu);
3015 if (pcp->pcp.count) {
3016 has_pcps = true;
3017 break;
3018 }
3019 }
3020 }
3021
3022 if (has_pcps)
3023 cpumask_set_cpu(cpu, &cpus_with_pcps);
3024 else
3025 cpumask_clear_cpu(cpu, &cpus_with_pcps);
3026 }
3027
3028 for_each_cpu(cpu, &cpus_with_pcps) {
3029 struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu);
3030
3031 drain->zone = zone;
3032 INIT_WORK(&drain->work, drain_local_pages_wq);
3033 queue_work_on(cpu, mm_percpu_wq, &drain->work);
3034 }
3035 for_each_cpu(cpu, &cpus_with_pcps)
3036 flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work);
3037
3038 mutex_unlock(&pcpu_drain_mutex);
3039}
3040
3041#ifdef CONFIG_HIBERNATION
3042
3043/*
3044 * Touch the watchdog for every WD_PAGE_COUNT pages.
3045 */
3046#define WD_PAGE_COUNT (128*1024)
3047
3048void mark_free_pages(struct zone *zone)
3049{
3050 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
3051 unsigned long flags;
3052 unsigned int order, t;
3053 struct page *page;
3054
3055 if (zone_is_empty(zone))
3056 return;
3057
3058 spin_lock_irqsave(&zone->lock, flags);
3059
3060 max_zone_pfn = zone_end_pfn(zone);
3061 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
3062 if (pfn_valid(pfn)) {
3063 page = pfn_to_page(pfn);
3064
3065 if (!--page_count) {
3066 touch_nmi_watchdog();
3067 page_count = WD_PAGE_COUNT;
3068 }
3069
3070 if (page_zone(page) != zone)
3071 continue;
3072
3073 if (!swsusp_page_is_forbidden(page))
3074 swsusp_unset_page_free(page);
3075 }
3076
3077 for_each_migratetype_order(order, t) {
3078 list_for_each_entry(page,
3079 &zone->free_area[order].free_list[t], lru) {
3080 unsigned long i;
3081
3082 pfn = page_to_pfn(page);
3083 for (i = 0; i < (1UL << order); i++) {
3084 if (!--page_count) {
3085 touch_nmi_watchdog();
3086 page_count = WD_PAGE_COUNT;
3087 }
3088 swsusp_set_page_free(pfn_to_page(pfn + i));
3089 }
3090 }
3091 }
3092 spin_unlock_irqrestore(&zone->lock, flags);
3093}
3094#endif /* CONFIG_PM */
3095
3096static bool free_unref_page_prepare(struct page *page, unsigned long pfn)
3097{
3098 int migratetype;
3099
3100 if (!free_pcp_prepare(page))
3101 return false;
3102
3103 migratetype = get_pfnblock_migratetype(page, pfn);
3104 set_pcppage_migratetype(page, migratetype);
3105 return true;
3106}
3107
3108static void free_unref_page_commit(struct page *page, unsigned long pfn)
3109{
3110 struct zone *zone = page_zone(page);
3111 struct per_cpu_pages *pcp;
3112 int migratetype;
3113
3114 migratetype = get_pcppage_migratetype(page);
3115 __count_vm_event(PGFREE);
3116
3117 /*
3118 * We only track unmovable, reclaimable and movable on pcp lists.
3119 * Free ISOLATE pages back to the allocator because they are being
3120 * offlined but treat HIGHATOMIC as movable pages so we can get those
3121 * areas back if necessary. Otherwise, we may have to free
3122 * excessively into the page allocator
3123 */
3124 if (migratetype >= MIGRATE_PCPTYPES) {
3125 if (unlikely(is_migrate_isolate(migratetype))) {
3126 free_one_page(zone, page, pfn, 0, migratetype);
3127 return;
3128 }
3129 migratetype = MIGRATE_MOVABLE;
3130 }
3131
3132 pcp = &this_cpu_ptr(zone->pageset)->pcp;
3133 list_add(&page->lru, &pcp->lists[migratetype]);
3134 pcp->count++;
3135 if (pcp->count >= pcp->high) {
3136 unsigned long batch = READ_ONCE(pcp->batch);
3137 free_pcppages_bulk(zone, batch, pcp);
3138 }
3139}
3140
3141/*
3142 * Free a 0-order page
3143 */
3144void free_unref_page(struct page *page)
3145{
3146 unsigned long flags;
3147 unsigned long pfn = page_to_pfn(page);
3148
3149 if (!free_unref_page_prepare(page, pfn))
3150 return;
3151
3152 local_irq_save(flags);
3153 free_unref_page_commit(page, pfn);
3154 local_irq_restore(flags);
3155}
3156
3157/*
3158 * Free a list of 0-order pages
3159 */
3160void free_unref_page_list(struct list_head *list)
3161{
3162 struct page *page, *next;
3163 unsigned long flags, pfn;
3164 int batch_count = 0;
3165
3166 /* Prepare pages for freeing */
3167 list_for_each_entry_safe(page, next, list, lru) {
3168 pfn = page_to_pfn(page);
3169 if (!free_unref_page_prepare(page, pfn))
3170 list_del(&page->lru);
3171 set_page_private(page, pfn);
3172 }
3173
3174 local_irq_save(flags);
3175 list_for_each_entry_safe(page, next, list, lru) {
3176 unsigned long pfn = page_private(page);
3177
3178 set_page_private(page, 0);
3179 trace_mm_page_free_batched(page);
3180 free_unref_page_commit(page, pfn);
3181
3182 /*
3183 * Guard against excessive IRQ disabled times when we get
3184 * a large list of pages to free.
3185 */
3186 if (++batch_count == SWAP_CLUSTER_MAX) {
3187 local_irq_restore(flags);
3188 batch_count = 0;
3189 local_irq_save(flags);
3190 }
3191 }
3192 local_irq_restore(flags);
3193}
3194
3195/*
3196 * split_page takes a non-compound higher-order page, and splits it into
3197 * n (1<<order) sub-pages: page[0..n]
3198 * Each sub-page must be freed individually.
3199 *
3200 * Note: this is probably too low level an operation for use in drivers.
3201 * Please consult with lkml before using this in your driver.
3202 */
3203void split_page(struct page *page, unsigned int order)
3204{
3205 int i;
3206
3207 VM_BUG_ON_PAGE(PageCompound(page), page);
3208 VM_BUG_ON_PAGE(!page_count(page), page);
3209
3210 for (i = 1; i < (1 << order); i++)
3211 set_page_refcounted(page + i);
3212 split_page_owner(page, order);
3213}
3214EXPORT_SYMBOL_GPL(split_page);
3215
3216int __isolate_free_page(struct page *page, unsigned int order)
3217{
3218 unsigned long watermark;
3219 struct zone *zone;
3220 int mt;
3221
3222 BUG_ON(!PageBuddy(page));
3223
3224 zone = page_zone(page);
3225 mt = get_pageblock_migratetype(page);
3226
3227 if (!is_migrate_isolate(mt)) {
3228 /*
3229 * Obey watermarks as if the page was being allocated. We can
3230 * emulate a high-order watermark check with a raised order-0
3231 * watermark, because we already know our high-order page
3232 * exists.
3233 */
3234 watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
3235 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
3236 return 0;
3237
3238 __mod_zone_freepage_state(zone, -(1UL << order), mt);
3239 }
3240
3241 /* Remove page from free list */
3242
3243 del_page_from_free_list(page, zone, order);
3244
3245 /*
3246 * Set the pageblock if the isolated page is at least half of a
3247 * pageblock
3248 */
3249 if (order >= pageblock_order - 1) {
3250 struct page *endpage = page + (1 << order) - 1;
3251 for (; page < endpage; page += pageblock_nr_pages) {
3252 int mt = get_pageblock_migratetype(page);
3253 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
3254 && !is_migrate_highatomic(mt))
3255 set_pageblock_migratetype(page,
3256 MIGRATE_MOVABLE);
3257 }
3258 }
3259
3260
3261 return 1UL << order;
3262}
3263
3264/**
3265 * __putback_isolated_page - Return a now-isolated page back where we got it
3266 * @page: Page that was isolated
3267 * @order: Order of the isolated page
3268 * @mt: The page's pageblock's migratetype
3269 *
3270 * This function is meant to return a page pulled from the free lists via
3271 * __isolate_free_page back to the free lists they were pulled from.
3272 */
3273void __putback_isolated_page(struct page *page, unsigned int order, int mt)
3274{
3275 struct zone *zone = page_zone(page);
3276
3277 /* zone lock should be held when this function is called */
3278 lockdep_assert_held(&zone->lock);
3279
3280 /* Return isolated page to tail of freelist. */
3281 __free_one_page(page, page_to_pfn(page), zone, order, mt, false);
3282}
3283
3284/*
3285 * Update NUMA hit/miss statistics
3286 *
3287 * Must be called with interrupts disabled.
3288 */
3289static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
3290{
3291#ifdef CONFIG_NUMA
3292 enum numa_stat_item local_stat = NUMA_LOCAL;
3293
3294 /* skip numa counters update if numa stats is disabled */
3295 if (!static_branch_likely(&vm_numa_stat_key))
3296 return;
3297
3298 if (zone_to_nid(z) != numa_node_id())
3299 local_stat = NUMA_OTHER;
3300
3301 if (zone_to_nid(z) == zone_to_nid(preferred_zone))
3302 __inc_numa_state(z, NUMA_HIT);
3303 else {
3304 __inc_numa_state(z, NUMA_MISS);
3305 __inc_numa_state(preferred_zone, NUMA_FOREIGN);
3306 }
3307 __inc_numa_state(z, local_stat);
3308#endif
3309}
3310
3311/* Remove page from the per-cpu list, caller must protect the list */
3312static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
3313 unsigned int alloc_flags,
3314 struct per_cpu_pages *pcp,
3315 struct list_head *list)
3316{
3317 struct page *page;
3318
3319 do {
3320 if (list_empty(list)) {
3321 pcp->count += rmqueue_bulk(zone, 0,
3322 pcp->batch, list,
3323 migratetype, alloc_flags);
3324 if (unlikely(list_empty(list)))
3325 return NULL;
3326 }
3327
3328 page = list_first_entry(list, struct page, lru);
3329 list_del(&page->lru);
3330 pcp->count--;
3331 } while (check_new_pcp(page));
3332
3333 return page;
3334}
3335
3336/* Lock and remove page from the per-cpu list */
3337static struct page *rmqueue_pcplist(struct zone *preferred_zone,
3338 struct zone *zone, gfp_t gfp_flags,
3339 int migratetype, unsigned int alloc_flags)
3340{
3341 struct per_cpu_pages *pcp;
3342 struct list_head *list;
3343 struct page *page;
3344 unsigned long flags;
3345
3346 local_irq_save(flags);
3347 pcp = &this_cpu_ptr(zone->pageset)->pcp;
3348 list = &pcp->lists[migratetype];
3349 page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list);
3350 if (page) {
3351 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1);
3352 zone_statistics(preferred_zone, zone);
3353 }
3354 local_irq_restore(flags);
3355 return page;
3356}
3357
3358/*
3359 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3360 */
3361static inline
3362struct page *rmqueue(struct zone *preferred_zone,
3363 struct zone *zone, unsigned int order,
3364 gfp_t gfp_flags, unsigned int alloc_flags,
3365 int migratetype)
3366{
3367 unsigned long flags;
3368 struct page *page;
3369
3370 if (likely(order == 0)) {
3371 /*
3372 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3373 * we need to skip it when CMA area isn't allowed.
3374 */
3375 if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA ||
3376 migratetype != MIGRATE_MOVABLE) {
3377 page = rmqueue_pcplist(preferred_zone, zone, gfp_flags,
3378 migratetype, alloc_flags);
3379 goto out;
3380 }
3381 }
3382
3383 /*
3384 * We most definitely don't want callers attempting to
3385 * allocate greater than order-1 page units with __GFP_NOFAIL.
3386 */
3387 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
3388 spin_lock_irqsave(&zone->lock, flags);
3389
3390 do {
3391 page = NULL;
3392 /*
3393 * order-0 request can reach here when the pcplist is skipped
3394 * due to non-CMA allocation context. HIGHATOMIC area is
3395 * reserved for high-order atomic allocation, so order-0
3396 * request should skip it.
3397 */
3398 if (order > 0 && alloc_flags & ALLOC_HARDER) {
3399 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
3400 if (page)
3401 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3402 }
3403 if (!page)
3404 page = __rmqueue(zone, order, migratetype, alloc_flags);
3405 } while (page && check_new_pages(page, order));
3406 spin_unlock(&zone->lock);
3407 if (!page)
3408 goto failed;
3409 __mod_zone_freepage_state(zone, -(1 << order),
3410 get_pcppage_migratetype(page));
3411
3412 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
3413 zone_statistics(preferred_zone, zone);
3414 local_irq_restore(flags);
3415
3416out:
3417 /* Separate test+clear to avoid unnecessary atomics */
3418 if (test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags)) {
3419 clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
3420 wakeup_kswapd(zone, 0, 0, zone_idx(zone));
3421 }
3422
3423 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
3424 return page;
3425
3426failed:
3427 local_irq_restore(flags);
3428 return NULL;
3429}
3430
3431#ifdef CONFIG_FAIL_PAGE_ALLOC
3432
3433static struct {
3434 struct fault_attr attr;
3435
3436 bool ignore_gfp_highmem;
3437 bool ignore_gfp_reclaim;
3438 u32 min_order;
3439} fail_page_alloc = {
3440 .attr = FAULT_ATTR_INITIALIZER,
3441 .ignore_gfp_reclaim = true,
3442 .ignore_gfp_highmem = true,
3443 .min_order = 1,
3444};
3445
3446static int __init setup_fail_page_alloc(char *str)
3447{
3448 return setup_fault_attr(&fail_page_alloc.attr, str);
3449}
3450__setup("fail_page_alloc=", setup_fail_page_alloc);
3451
3452static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3453{
3454 if (order < fail_page_alloc.min_order)
3455 return false;
3456 if (gfp_mask & __GFP_NOFAIL)
3457 return false;
3458 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
3459 return false;
3460 if (fail_page_alloc.ignore_gfp_reclaim &&
3461 (gfp_mask & __GFP_DIRECT_RECLAIM))
3462 return false;
3463
3464 return should_fail(&fail_page_alloc.attr, 1 << order);
3465}
3466
3467#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3468
3469static int __init fail_page_alloc_debugfs(void)
3470{
3471 umode_t mode = S_IFREG | 0600;
3472 struct dentry *dir;
3473
3474 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
3475 &fail_page_alloc.attr);
3476
3477 debugfs_create_bool("ignore-gfp-wait", mode, dir,
3478 &fail_page_alloc.ignore_gfp_reclaim);
3479 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
3480 &fail_page_alloc.ignore_gfp_highmem);
3481 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);
3482
3483 return 0;
3484}
3485
3486late_initcall(fail_page_alloc_debugfs);
3487
3488#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3489
3490#else /* CONFIG_FAIL_PAGE_ALLOC */
3491
3492static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3493{
3494 return false;
3495}
3496
3497#endif /* CONFIG_FAIL_PAGE_ALLOC */
3498
3499static noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3500{
3501 return __should_fail_alloc_page(gfp_mask, order);
3502}
3503ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
3504
3505static inline long __zone_watermark_unusable_free(struct zone *z,
3506 unsigned int order, unsigned int alloc_flags)
3507{
3508 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3509 long unusable_free = (1 << order) - 1;
3510
3511 /*
3512 * If the caller does not have rights to ALLOC_HARDER then subtract
3513 * the high-atomic reserves. This will over-estimate the size of the
3514 * atomic reserve but it avoids a search.
3515 */
3516 if (likely(!alloc_harder))
3517 unusable_free += z->nr_reserved_highatomic;
3518
3519#ifdef CONFIG_CMA
3520 /* If allocation can't use CMA areas don't use free CMA pages */
3521 if (!(alloc_flags & ALLOC_CMA))
3522 unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES);
3523#endif
3524
3525 return unusable_free;
3526}
3527
3528/*
3529 * Return true if free base pages are above 'mark'. For high-order checks it
3530 * will return true of the order-0 watermark is reached and there is at least
3531 * one free page of a suitable size. Checking now avoids taking the zone lock
3532 * to check in the allocation paths if no pages are free.
3533 */
3534bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3535 int highest_zoneidx, unsigned int alloc_flags,
3536 long free_pages)
3537{
3538 long min = mark;
3539 int o;
3540 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3541
3542 /* free_pages may go negative - that's OK */
3543 free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags);
3544
3545 if (alloc_flags & ALLOC_HIGH)
3546 min -= min / 2;
3547
3548 if (unlikely(alloc_harder)) {
3549 /*
3550 * OOM victims can try even harder than normal ALLOC_HARDER
3551 * users on the grounds that it's definitely going to be in
3552 * the exit path shortly and free memory. Any allocation it
3553 * makes during the free path will be small and short-lived.
3554 */
3555 if (alloc_flags & ALLOC_OOM)
3556 min -= min / 2;
3557 else
3558 min -= min / 4;
3559 }
3560
3561 /*
3562 * Check watermarks for an order-0 allocation request. If these
3563 * are not met, then a high-order request also cannot go ahead
3564 * even if a suitable page happened to be free.
3565 */
3566 if (free_pages <= min + z->lowmem_reserve[highest_zoneidx])
3567 return false;
3568
3569 /* If this is an order-0 request then the watermark is fine */
3570 if (!order)
3571 return true;
3572
3573 /* For a high-order request, check at least one suitable page is free */
3574 for (o = order; o < MAX_ORDER; o++) {
3575 struct free_area *area = &z->free_area[o];
3576 int mt;
3577
3578 if (!area->nr_free)
3579 continue;
3580
3581 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
3582 if (!free_area_empty(area, mt))
3583 return true;
3584 }
3585
3586#ifdef CONFIG_CMA
3587 if ((alloc_flags & ALLOC_CMA) &&
3588 !free_area_empty(area, MIGRATE_CMA)) {
3589 return true;
3590 }
3591#endif
3592 if (alloc_harder && !free_area_empty(area, MIGRATE_HIGHATOMIC))
3593 return true;
3594 }
3595 return false;
3596}
3597
3598bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3599 int highest_zoneidx, unsigned int alloc_flags)
3600{
3601 return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
3602 zone_page_state(z, NR_FREE_PAGES));
3603}
3604
3605static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
3606 unsigned long mark, int highest_zoneidx,
3607 unsigned int alloc_flags, gfp_t gfp_mask)
3608{
3609 long free_pages;
3610
3611 free_pages = zone_page_state(z, NR_FREE_PAGES);
3612
3613 /*
3614 * Fast check for order-0 only. If this fails then the reserves
3615 * need to be calculated.
3616 */
3617 if (!order) {
3618 long fast_free;
3619
3620 fast_free = free_pages;
3621 fast_free -= __zone_watermark_unusable_free(z, 0, alloc_flags);
3622 if (fast_free > mark + z->lowmem_reserve[highest_zoneidx])
3623 return true;
3624 }
3625
3626 if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
3627 free_pages))
3628 return true;
3629 /*
3630 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3631 * when checking the min watermark. The min watermark is the
3632 * point where boosting is ignored so that kswapd is woken up
3633 * when below the low watermark.
3634 */
3635 if (unlikely(!order && (gfp_mask & __GFP_ATOMIC) && z->watermark_boost
3636 && ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) {
3637 mark = z->_watermark[WMARK_MIN];
3638 return __zone_watermark_ok(z, order, mark, highest_zoneidx,
3639 alloc_flags, free_pages);
3640 }
3641
3642 return false;
3643}
3644
3645bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
3646 unsigned long mark, int highest_zoneidx)
3647{
3648 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3649
3650 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
3651 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
3652
3653 return __zone_watermark_ok(z, order, mark, highest_zoneidx, 0,
3654 free_pages);
3655}
3656
3657#ifdef CONFIG_NUMA
3658static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3659{
3660 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3661 node_reclaim_distance;
3662}
3663#else /* CONFIG_NUMA */
3664static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3665{
3666 return true;
3667}
3668#endif /* CONFIG_NUMA */
3669
3670/*
3671 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3672 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3673 * premature use of a lower zone may cause lowmem pressure problems that
3674 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3675 * probably too small. It only makes sense to spread allocations to avoid
3676 * fragmentation between the Normal and DMA32 zones.
3677 */
3678static inline unsigned int
3679alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
3680{
3681 unsigned int alloc_flags;
3682
3683 /*
3684 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3685 * to save a branch.
3686 */
3687 alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM);
3688
3689#ifdef CONFIG_ZONE_DMA32
3690 if (!zone)
3691 return alloc_flags;
3692
3693 if (zone_idx(zone) != ZONE_NORMAL)
3694 return alloc_flags;
3695
3696 /*
3697 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3698 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3699 * on UMA that if Normal is populated then so is DMA32.
3700 */
3701 BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1);
3702 if (nr_online_nodes > 1 && !populated_zone(--zone))
3703 return alloc_flags;
3704
3705 alloc_flags |= ALLOC_NOFRAGMENT;
3706#endif /* CONFIG_ZONE_DMA32 */
3707 return alloc_flags;
3708}
3709
3710static inline unsigned int current_alloc_flags(gfp_t gfp_mask,
3711 unsigned int alloc_flags)
3712{
3713#ifdef CONFIG_CMA
3714 unsigned int pflags = current->flags;
3715
3716 if (!(pflags & PF_MEMALLOC_NOCMA) &&
3717 gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3718 alloc_flags |= ALLOC_CMA;
3719
3720#endif
3721 return alloc_flags;
3722}
3723
3724/*
3725 * get_page_from_freelist goes through the zonelist trying to allocate
3726 * a page.
3727 */
3728static struct page *
3729get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
3730 const struct alloc_context *ac)
3731{
3732 struct zoneref *z;
3733 struct zone *zone;
3734 struct pglist_data *last_pgdat_dirty_limit = NULL;
3735 bool no_fallback;
3736
3737retry:
3738 /*
3739 * Scan zonelist, looking for a zone with enough free.
3740 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3741 */
3742 no_fallback = alloc_flags & ALLOC_NOFRAGMENT;
3743 z = ac->preferred_zoneref;
3744 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist,
3745 ac->highest_zoneidx, ac->nodemask) {
3746 struct page *page;
3747 unsigned long mark;
3748
3749 if (cpusets_enabled() &&
3750 (alloc_flags & ALLOC_CPUSET) &&
3751 !__cpuset_zone_allowed(zone, gfp_mask))
3752 continue;
3753 /*
3754 * When allocating a page cache page for writing, we
3755 * want to get it from a node that is within its dirty
3756 * limit, such that no single node holds more than its
3757 * proportional share of globally allowed dirty pages.
3758 * The dirty limits take into account the node's
3759 * lowmem reserves and high watermark so that kswapd
3760 * should be able to balance it without having to
3761 * write pages from its LRU list.
3762 *
3763 * XXX: For now, allow allocations to potentially
3764 * exceed the per-node dirty limit in the slowpath
3765 * (spread_dirty_pages unset) before going into reclaim,
3766 * which is important when on a NUMA setup the allowed
3767 * nodes are together not big enough to reach the
3768 * global limit. The proper fix for these situations
3769 * will require awareness of nodes in the
3770 * dirty-throttling and the flusher threads.
3771 */
3772 if (ac->spread_dirty_pages) {
3773 if (last_pgdat_dirty_limit == zone->zone_pgdat)
3774 continue;
3775
3776 if (!node_dirty_ok(zone->zone_pgdat)) {
3777 last_pgdat_dirty_limit = zone->zone_pgdat;
3778 continue;
3779 }
3780 }
3781
3782 if (no_fallback && nr_online_nodes > 1 &&
3783 zone != ac->preferred_zoneref->zone) {
3784 int local_nid;
3785
3786 /*
3787 * If moving to a remote node, retry but allow
3788 * fragmenting fallbacks. Locality is more important
3789 * than fragmentation avoidance.
3790 */
3791 local_nid = zone_to_nid(ac->preferred_zoneref->zone);
3792 if (zone_to_nid(zone) != local_nid) {
3793 alloc_flags &= ~ALLOC_NOFRAGMENT;
3794 goto retry;
3795 }
3796 }
3797
3798 mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
3799 if (!zone_watermark_fast(zone, order, mark,
3800 ac->highest_zoneidx, alloc_flags,
3801 gfp_mask)) {
3802 int ret;
3803
3804#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3805 /*
3806 * Watermark failed for this zone, but see if we can
3807 * grow this zone if it contains deferred pages.
3808 */
3809 if (static_branch_unlikely(&deferred_pages)) {
3810 if (_deferred_grow_zone(zone, order))
3811 goto try_this_zone;
3812 }
3813#endif
3814 /* Checked here to keep the fast path fast */
3815 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
3816 if (alloc_flags & ALLOC_NO_WATERMARKS)
3817 goto try_this_zone;
3818
3819 if (node_reclaim_mode == 0 ||
3820 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
3821 continue;
3822
3823 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
3824 switch (ret) {
3825 case NODE_RECLAIM_NOSCAN:
3826 /* did not scan */
3827 continue;
3828 case NODE_RECLAIM_FULL:
3829 /* scanned but unreclaimable */
3830 continue;
3831 default:
3832 /* did we reclaim enough */
3833 if (zone_watermark_ok(zone, order, mark,
3834 ac->highest_zoneidx, alloc_flags))
3835 goto try_this_zone;
3836
3837 continue;
3838 }
3839 }
3840
3841try_this_zone:
3842 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
3843 gfp_mask, alloc_flags, ac->migratetype);
3844 if (page) {
3845 prep_new_page(page, order, gfp_mask, alloc_flags);
3846
3847 /*
3848 * If this is a high-order atomic allocation then check
3849 * if the pageblock should be reserved for the future
3850 */
3851 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3852 reserve_highatomic_pageblock(page, zone, order);
3853
3854 return page;
3855 } else {
3856#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3857 /* Try again if zone has deferred pages */
3858 if (static_branch_unlikely(&deferred_pages)) {
3859 if (_deferred_grow_zone(zone, order))
3860 goto try_this_zone;
3861 }
3862#endif
3863 }
3864 }
3865
3866 /*
3867 * It's possible on a UMA machine to get through all zones that are
3868 * fragmented. If avoiding fragmentation, reset and try again.
3869 */
3870 if (no_fallback) {
3871 alloc_flags &= ~ALLOC_NOFRAGMENT;
3872 goto retry;
3873 }
3874
3875 return NULL;
3876}
3877
3878static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
3879{
3880 unsigned int filter = SHOW_MEM_FILTER_NODES;
3881
3882 /*
3883 * This documents exceptions given to allocations in certain
3884 * contexts that are allowed to allocate outside current's set
3885 * of allowed nodes.
3886 */
3887 if (!(gfp_mask & __GFP_NOMEMALLOC))
3888 if (tsk_is_oom_victim(current) ||
3889 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3890 filter &= ~SHOW_MEM_FILTER_NODES;
3891 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3892 filter &= ~SHOW_MEM_FILTER_NODES;
3893
3894 show_mem(filter, nodemask);
3895}
3896
3897void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
3898{
3899 struct va_format vaf;
3900 va_list args;
3901 static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1);
3902
3903 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
3904 return;
3905
3906 va_start(args, fmt);
3907 vaf.fmt = fmt;
3908 vaf.va = &args;
3909 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
3910 current->comm, &vaf, gfp_mask, &gfp_mask,
3911 nodemask_pr_args(nodemask));
3912 va_end(args);
3913
3914 cpuset_print_current_mems_allowed();
3915 pr_cont("\n");
3916 dump_stack();
3917 warn_alloc_show_mem(gfp_mask, nodemask);
3918}
3919
3920static inline struct page *
3921__alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
3922 unsigned int alloc_flags,
3923 const struct alloc_context *ac)
3924{
3925 struct page *page;
3926
3927 page = get_page_from_freelist(gfp_mask, order,
3928 alloc_flags|ALLOC_CPUSET, ac);
3929 /*
3930 * fallback to ignore cpuset restriction if our nodes
3931 * are depleted
3932 */
3933 if (!page)
3934 page = get_page_from_freelist(gfp_mask, order,
3935 alloc_flags, ac);
3936
3937 return page;
3938}
3939
3940static inline struct page *
3941__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3942 const struct alloc_context *ac, unsigned long *did_some_progress)
3943{
3944 struct oom_control oc = {
3945 .zonelist = ac->zonelist,
3946 .nodemask = ac->nodemask,
3947 .memcg = NULL,
3948 .gfp_mask = gfp_mask,
3949 .order = order,
3950 };
3951 struct page *page;
3952
3953 *did_some_progress = 0;
3954
3955 /*
3956 * Acquire the oom lock. If that fails, somebody else is
3957 * making progress for us.
3958 */
3959 if (!mutex_trylock(&oom_lock)) {
3960 *did_some_progress = 1;
3961 schedule_timeout_uninterruptible(1);
3962 return NULL;
3963 }
3964
3965 /*
3966 * Go through the zonelist yet one more time, keep very high watermark
3967 * here, this is only to catch a parallel oom killing, we must fail if
3968 * we're still under heavy pressure. But make sure that this reclaim
3969 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3970 * allocation which will never fail due to oom_lock already held.
3971 */
3972 page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
3973 ~__GFP_DIRECT_RECLAIM, order,
3974 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3975 if (page)
3976 goto out;
3977
3978 /* Coredumps can quickly deplete all memory reserves */
3979 if (current->flags & PF_DUMPCORE)
3980 goto out;
3981 /* The OOM killer will not help higher order allocs */
3982 if (order > PAGE_ALLOC_COSTLY_ORDER)
3983 goto out;
3984 /*
3985 * We have already exhausted all our reclaim opportunities without any
3986 * success so it is time to admit defeat. We will skip the OOM killer
3987 * because it is very likely that the caller has a more reasonable
3988 * fallback than shooting a random task.
3989 */
3990 if (gfp_mask & __GFP_RETRY_MAYFAIL)
3991 goto out;
3992 /* The OOM killer does not needlessly kill tasks for lowmem */
3993 if (ac->highest_zoneidx < ZONE_NORMAL)
3994 goto out;
3995 if (pm_suspended_storage())
3996 goto out;
3997 /*
3998 * XXX: GFP_NOFS allocations should rather fail than rely on
3999 * other request to make a forward progress.
4000 * We are in an unfortunate situation where out_of_memory cannot
4001 * do much for this context but let's try it to at least get
4002 * access to memory reserved if the current task is killed (see
4003 * out_of_memory). Once filesystems are ready to handle allocation
4004 * failures more gracefully we should just bail out here.
4005 */
4006
4007 /* The OOM killer may not free memory on a specific node */
4008 if (gfp_mask & __GFP_THISNODE)
4009 goto out;
4010
4011 /* Exhausted what can be done so it's blame time */
4012 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
4013 *did_some_progress = 1;
4014
4015 /*
4016 * Help non-failing allocations by giving them access to memory
4017 * reserves
4018 */
4019 if (gfp_mask & __GFP_NOFAIL)
4020 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
4021 ALLOC_NO_WATERMARKS, ac);
4022 }
4023out:
4024 mutex_unlock(&oom_lock);
4025 return page;
4026}
4027
4028/*
4029 * Maximum number of compaction retries wit a progress before OOM
4030 * killer is consider as the only way to move forward.
4031 */
4032#define MAX_COMPACT_RETRIES 16
4033
4034#ifdef CONFIG_COMPACTION
4035/* Try memory compaction for high-order allocations before reclaim */
4036static struct page *
4037__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4038 unsigned int alloc_flags, const struct alloc_context *ac,
4039 enum compact_priority prio, enum compact_result *compact_result)
4040{
4041 struct page *page = NULL;
4042 unsigned long pflags;
4043 unsigned int noreclaim_flag;
4044
4045 if (!order)
4046 return NULL;
4047
4048 psi_memstall_enter(&pflags);
4049 noreclaim_flag = memalloc_noreclaim_save();
4050
4051 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
4052 prio, &page);
4053
4054 memalloc_noreclaim_restore(noreclaim_flag);
4055 psi_memstall_leave(&pflags);
4056
4057 /*
4058 * At least in one zone compaction wasn't deferred or skipped, so let's
4059 * count a compaction stall
4060 */
4061 count_vm_event(COMPACTSTALL);
4062
4063 /* Prep a captured page if available */
4064 if (page)
4065 prep_new_page(page, order, gfp_mask, alloc_flags);
4066
4067 /* Try get a page from the freelist if available */
4068 if (!page)
4069 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4070
4071 if (page) {
4072 struct zone *zone = page_zone(page);
4073
4074 zone->compact_blockskip_flush = false;
4075 compaction_defer_reset(zone, order, true);
4076 count_vm_event(COMPACTSUCCESS);
4077 return page;
4078 }
4079
4080 /*
4081 * It's bad if compaction run occurs and fails. The most likely reason
4082 * is that pages exist, but not enough to satisfy watermarks.
4083 */
4084 count_vm_event(COMPACTFAIL);
4085
4086 cond_resched();
4087
4088 return NULL;
4089}
4090
4091static inline bool
4092should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
4093 enum compact_result compact_result,
4094 enum compact_priority *compact_priority,
4095 int *compaction_retries)
4096{
4097 int max_retries = MAX_COMPACT_RETRIES;
4098 int min_priority;
4099 bool ret = false;
4100 int retries = *compaction_retries;
4101 enum compact_priority priority = *compact_priority;
4102
4103 if (!order)
4104 return false;
4105
4106 if (compaction_made_progress(compact_result))
4107 (*compaction_retries)++;
4108
4109 /*
4110 * compaction considers all the zone as desperately out of memory
4111 * so it doesn't really make much sense to retry except when the
4112 * failure could be caused by insufficient priority
4113 */
4114 if (compaction_failed(compact_result))
4115 goto check_priority;
4116
4117 /*
4118 * compaction was skipped because there are not enough order-0 pages
4119 * to work with, so we retry only if it looks like reclaim can help.
4120 */
4121 if (compaction_needs_reclaim(compact_result)) {
4122 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
4123 goto out;
4124 }
4125
4126 /*
4127 * make sure the compaction wasn't deferred or didn't bail out early
4128 * due to locks contention before we declare that we should give up.
4129 * But the next retry should use a higher priority if allowed, so
4130 * we don't just keep bailing out endlessly.
4131 */
4132 if (compaction_withdrawn(compact_result)) {
4133 goto check_priority;
4134 }
4135
4136 /*
4137 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4138 * costly ones because they are de facto nofail and invoke OOM
4139 * killer to move on while costly can fail and users are ready
4140 * to cope with that. 1/4 retries is rather arbitrary but we
4141 * would need much more detailed feedback from compaction to
4142 * make a better decision.
4143 */
4144 if (order > PAGE_ALLOC_COSTLY_ORDER)
4145 max_retries /= 4;
4146 if (*compaction_retries <= max_retries) {
4147 ret = true;
4148 goto out;
4149 }
4150
4151 /*
4152 * Make sure there are attempts at the highest priority if we exhausted
4153 * all retries or failed at the lower priorities.
4154 */
4155check_priority:
4156 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
4157 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
4158
4159 if (*compact_priority > min_priority) {
4160 (*compact_priority)--;
4161 *compaction_retries = 0;
4162 ret = true;
4163 }
4164out:
4165 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
4166 return ret;
4167}
4168#else
4169static inline struct page *
4170__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4171 unsigned int alloc_flags, const struct alloc_context *ac,
4172 enum compact_priority prio, enum compact_result *compact_result)
4173{
4174 *compact_result = COMPACT_SKIPPED;
4175 return NULL;
4176}
4177
4178static inline bool
4179should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
4180 enum compact_result compact_result,
4181 enum compact_priority *compact_priority,
4182 int *compaction_retries)
4183{
4184 struct zone *zone;
4185 struct zoneref *z;
4186
4187 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
4188 return false;
4189
4190 /*
4191 * There are setups with compaction disabled which would prefer to loop
4192 * inside the allocator rather than hit the oom killer prematurely.
4193 * Let's give them a good hope and keep retrying while the order-0
4194 * watermarks are OK.
4195 */
4196 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
4197 ac->highest_zoneidx, ac->nodemask) {
4198 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
4199 ac->highest_zoneidx, alloc_flags))
4200 return true;
4201 }
4202 return false;
4203}
4204#endif /* CONFIG_COMPACTION */
4205
4206#ifdef CONFIG_LOCKDEP
4207static struct lockdep_map __fs_reclaim_map =
4208 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
4209
4210static bool __need_fs_reclaim(gfp_t gfp_mask)
4211{
4212 gfp_mask = current_gfp_context(gfp_mask);
4213
4214 /* no reclaim without waiting on it */
4215 if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
4216 return false;
4217
4218 /* this guy won't enter reclaim */
4219 if (current->flags & PF_MEMALLOC)
4220 return false;
4221
4222 /* We're only interested __GFP_FS allocations for now */
4223 if (!(gfp_mask & __GFP_FS))
4224 return false;
4225
4226 if (gfp_mask & __GFP_NOLOCKDEP)
4227 return false;
4228
4229 return true;
4230}
4231
4232void __fs_reclaim_acquire(void)
4233{
4234 lock_map_acquire(&__fs_reclaim_map);
4235}
4236
4237void __fs_reclaim_release(void)
4238{
4239 lock_map_release(&__fs_reclaim_map);
4240}
4241
4242void fs_reclaim_acquire(gfp_t gfp_mask)
4243{
4244 if (__need_fs_reclaim(gfp_mask))
4245 __fs_reclaim_acquire();
4246}
4247EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
4248
4249void fs_reclaim_release(gfp_t gfp_mask)
4250{
4251 if (__need_fs_reclaim(gfp_mask))
4252 __fs_reclaim_release();
4253}
4254EXPORT_SYMBOL_GPL(fs_reclaim_release);
4255#endif
4256
4257/* Perform direct synchronous page reclaim */
4258static int
4259__perform_reclaim(gfp_t gfp_mask, unsigned int order,
4260 const struct alloc_context *ac)
4261{
4262 int progress;
4263 unsigned int noreclaim_flag;
4264 unsigned long pflags;
4265
4266 cond_resched();
4267
4268 /* We now go into synchronous reclaim */
4269 cpuset_memory_pressure_bump();
4270 psi_memstall_enter(&pflags);
4271 fs_reclaim_acquire(gfp_mask);
4272 noreclaim_flag = memalloc_noreclaim_save();
4273
4274 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
4275 ac->nodemask);
4276
4277 memalloc_noreclaim_restore(noreclaim_flag);
4278 fs_reclaim_release(gfp_mask);
4279 psi_memstall_leave(&pflags);
4280
4281 cond_resched();
4282
4283 return progress;
4284}
4285
4286/* The really slow allocator path where we enter direct reclaim */
4287static inline struct page *
4288__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
4289 unsigned int alloc_flags, const struct alloc_context *ac,
4290 unsigned long *did_some_progress)
4291{
4292 struct page *page = NULL;
4293 bool drained = false;
4294
4295 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
4296 if (unlikely(!(*did_some_progress)))
4297 return NULL;
4298
4299retry:
4300 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4301
4302 /*
4303 * If an allocation failed after direct reclaim, it could be because
4304 * pages are pinned on the per-cpu lists or in high alloc reserves.
4305 * Shrink them and try again
4306 */
4307 if (!page && !drained) {
4308 unreserve_highatomic_pageblock(ac, false);
4309 drain_all_pages(NULL);
4310 drained = true;
4311 goto retry;
4312 }
4313
4314 return page;
4315}
4316
4317static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
4318 const struct alloc_context *ac)
4319{
4320 struct zoneref *z;
4321 struct zone *zone;
4322 pg_data_t *last_pgdat = NULL;
4323 enum zone_type highest_zoneidx = ac->highest_zoneidx;
4324
4325 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
4326 ac->nodemask) {
4327 if (last_pgdat != zone->zone_pgdat)
4328 wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
4329 last_pgdat = zone->zone_pgdat;
4330 }
4331}
4332
4333static inline unsigned int
4334gfp_to_alloc_flags(gfp_t gfp_mask)
4335{
4336 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
4337
4338 /*
4339 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4340 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4341 * to save two branches.
4342 */
4343 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
4344 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD);
4345
4346 /*
4347 * The caller may dip into page reserves a bit more if the caller
4348 * cannot run direct reclaim, or if the caller has realtime scheduling
4349 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4350 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4351 */
4352 alloc_flags |= (__force int)
4353 (gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM));
4354
4355 if (gfp_mask & __GFP_ATOMIC) {
4356 /*
4357 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4358 * if it can't schedule.
4359 */
4360 if (!(gfp_mask & __GFP_NOMEMALLOC))
4361 alloc_flags |= ALLOC_HARDER;
4362 /*
4363 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4364 * comment for __cpuset_node_allowed().
4365 */
4366 alloc_flags &= ~ALLOC_CPUSET;
4367 } else if (unlikely(rt_task(current)) && !in_interrupt())
4368 alloc_flags |= ALLOC_HARDER;
4369
4370 alloc_flags = current_alloc_flags(gfp_mask, alloc_flags);
4371
4372 return alloc_flags;
4373}
4374
4375static bool oom_reserves_allowed(struct task_struct *tsk)
4376{
4377 if (!tsk_is_oom_victim(tsk))
4378 return false;
4379
4380 /*
4381 * !MMU doesn't have oom reaper so give access to memory reserves
4382 * only to the thread with TIF_MEMDIE set
4383 */
4384 if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
4385 return false;
4386
4387 return true;
4388}
4389
4390/*
4391 * Distinguish requests which really need access to full memory
4392 * reserves from oom victims which can live with a portion of it
4393 */
4394static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
4395{
4396 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
4397 return 0;
4398 if (gfp_mask & __GFP_MEMALLOC)
4399 return ALLOC_NO_WATERMARKS;
4400 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
4401 return ALLOC_NO_WATERMARKS;
4402 if (!in_interrupt()) {
4403 if (current->flags & PF_MEMALLOC)
4404 return ALLOC_NO_WATERMARKS;
4405 else if (oom_reserves_allowed(current))
4406 return ALLOC_OOM;
4407 }
4408
4409 return 0;
4410}
4411
4412bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
4413{
4414 return !!__gfp_pfmemalloc_flags(gfp_mask);
4415}
4416
4417/*
4418 * Checks whether it makes sense to retry the reclaim to make a forward progress
4419 * for the given allocation request.
4420 *
4421 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4422 * without success, or when we couldn't even meet the watermark if we
4423 * reclaimed all remaining pages on the LRU lists.
4424 *
4425 * Returns true if a retry is viable or false to enter the oom path.
4426 */
4427static inline bool
4428should_reclaim_retry(gfp_t gfp_mask, unsigned order,
4429 struct alloc_context *ac, int alloc_flags,
4430 bool did_some_progress, int *no_progress_loops)
4431{
4432 struct zone *zone;
4433 struct zoneref *z;
4434 bool ret = false;
4435
4436 /*
4437 * Costly allocations might have made a progress but this doesn't mean
4438 * their order will become available due to high fragmentation so
4439 * always increment the no progress counter for them
4440 */
4441 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
4442 *no_progress_loops = 0;
4443 else
4444 (*no_progress_loops)++;
4445
4446 /*
4447 * Make sure we converge to OOM if we cannot make any progress
4448 * several times in the row.
4449 */
4450 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
4451 /* Before OOM, exhaust highatomic_reserve */
4452 return unreserve_highatomic_pageblock(ac, true);
4453 }
4454
4455 /*
4456 * Keep reclaiming pages while there is a chance this will lead
4457 * somewhere. If none of the target zones can satisfy our allocation
4458 * request even if all reclaimable pages are considered then we are
4459 * screwed and have to go OOM.
4460 */
4461 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
4462 ac->highest_zoneidx, ac->nodemask) {
4463 unsigned long available;
4464 unsigned long reclaimable;
4465 unsigned long min_wmark = min_wmark_pages(zone);
4466 bool wmark;
4467
4468 available = reclaimable = zone_reclaimable_pages(zone);
4469 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
4470
4471 /*
4472 * Would the allocation succeed if we reclaimed all
4473 * reclaimable pages?
4474 */
4475 wmark = __zone_watermark_ok(zone, order, min_wmark,
4476 ac->highest_zoneidx, alloc_flags, available);
4477 trace_reclaim_retry_zone(z, order, reclaimable,
4478 available, min_wmark, *no_progress_loops, wmark);
4479 if (wmark) {
4480 /*
4481 * If we didn't make any progress and have a lot of
4482 * dirty + writeback pages then we should wait for
4483 * an IO to complete to slow down the reclaim and
4484 * prevent from pre mature OOM
4485 */
4486 if (!did_some_progress) {
4487 unsigned long write_pending;
4488
4489 write_pending = zone_page_state_snapshot(zone,
4490 NR_ZONE_WRITE_PENDING);
4491
4492 if (2 * write_pending > reclaimable) {
4493 congestion_wait(BLK_RW_ASYNC, HZ/10);
4494 return true;
4495 }
4496 }
4497
4498 ret = true;
4499 goto out;
4500 }
4501 }
4502
4503out:
4504 /*
4505 * Memory allocation/reclaim might be called from a WQ context and the
4506 * current implementation of the WQ concurrency control doesn't
4507 * recognize that a particular WQ is congested if the worker thread is
4508 * looping without ever sleeping. Therefore we have to do a short sleep
4509 * here rather than calling cond_resched().
4510 */
4511 if (current->flags & PF_WQ_WORKER)
4512 schedule_timeout_uninterruptible(1);
4513 else
4514 cond_resched();
4515 return ret;
4516}
4517
4518static inline bool
4519check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
4520{
4521 /*
4522 * It's possible that cpuset's mems_allowed and the nodemask from
4523 * mempolicy don't intersect. This should be normally dealt with by
4524 * policy_nodemask(), but it's possible to race with cpuset update in
4525 * such a way the check therein was true, and then it became false
4526 * before we got our cpuset_mems_cookie here.
4527 * This assumes that for all allocations, ac->nodemask can come only
4528 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4529 * when it does not intersect with the cpuset restrictions) or the
4530 * caller can deal with a violated nodemask.
4531 */
4532 if (cpusets_enabled() && ac->nodemask &&
4533 !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
4534 ac->nodemask = NULL;
4535 return true;
4536 }
4537
4538 /*
4539 * When updating a task's mems_allowed or mempolicy nodemask, it is
4540 * possible to race with parallel threads in such a way that our
4541 * allocation can fail while the mask is being updated. If we are about
4542 * to fail, check if the cpuset changed during allocation and if so,
4543 * retry.
4544 */
4545 if (read_mems_allowed_retry(cpuset_mems_cookie))
4546 return true;
4547
4548 return false;
4549}
4550
4551static inline struct page *
4552__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
4553 struct alloc_context *ac)
4554{
4555 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
4556 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
4557 struct page *page = NULL;
4558 unsigned int alloc_flags;
4559 unsigned long did_some_progress;
4560 enum compact_priority compact_priority;
4561 enum compact_result compact_result;
4562 int compaction_retries;
4563 int no_progress_loops;
4564 unsigned int cpuset_mems_cookie;
4565 int reserve_flags;
4566
4567 /*
4568 * We also sanity check to catch abuse of atomic reserves being used by
4569 * callers that are not in atomic context.
4570 */
4571 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
4572 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
4573 gfp_mask &= ~__GFP_ATOMIC;
4574
4575retry_cpuset:
4576 compaction_retries = 0;
4577 no_progress_loops = 0;
4578 compact_priority = DEF_COMPACT_PRIORITY;
4579 cpuset_mems_cookie = read_mems_allowed_begin();
4580
4581 /*
4582 * The fast path uses conservative alloc_flags to succeed only until
4583 * kswapd needs to be woken up, and to avoid the cost of setting up
4584 * alloc_flags precisely. So we do that now.
4585 */
4586 alloc_flags = gfp_to_alloc_flags(gfp_mask);
4587
4588 /*
4589 * We need to recalculate the starting point for the zonelist iterator
4590 * because we might have used different nodemask in the fast path, or
4591 * there was a cpuset modification and we are retrying - otherwise we
4592 * could end up iterating over non-eligible zones endlessly.
4593 */
4594 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4595 ac->highest_zoneidx, ac->nodemask);
4596 if (!ac->preferred_zoneref->zone)
4597 goto nopage;
4598
4599 if (alloc_flags & ALLOC_KSWAPD)
4600 wake_all_kswapds(order, gfp_mask, ac);
4601
4602 /*
4603 * The adjusted alloc_flags might result in immediate success, so try
4604 * that first
4605 */
4606 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4607 if (page)
4608 goto got_pg;
4609
4610 /*
4611 * For costly allocations, try direct compaction first, as it's likely
4612 * that we have enough base pages and don't need to reclaim. For non-
4613 * movable high-order allocations, do that as well, as compaction will
4614 * try prevent permanent fragmentation by migrating from blocks of the
4615 * same migratetype.
4616 * Don't try this for allocations that are allowed to ignore
4617 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4618 */
4619 if (can_direct_reclaim &&
4620 (costly_order ||
4621 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
4622 && !gfp_pfmemalloc_allowed(gfp_mask)) {
4623 page = __alloc_pages_direct_compact(gfp_mask, order,
4624 alloc_flags, ac,
4625 INIT_COMPACT_PRIORITY,
4626 &compact_result);
4627 if (page)
4628 goto got_pg;
4629
4630 /*
4631 * Checks for costly allocations with __GFP_NORETRY, which
4632 * includes some THP page fault allocations
4633 */
4634 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
4635 /*
4636 * If allocating entire pageblock(s) and compaction
4637 * failed because all zones are below low watermarks
4638 * or is prohibited because it recently failed at this
4639 * order, fail immediately unless the allocator has
4640 * requested compaction and reclaim retry.
4641 *
4642 * Reclaim is
4643 * - potentially very expensive because zones are far
4644 * below their low watermarks or this is part of very
4645 * bursty high order allocations,
4646 * - not guaranteed to help because isolate_freepages()
4647 * may not iterate over freed pages as part of its
4648 * linear scan, and
4649 * - unlikely to make entire pageblocks free on its
4650 * own.
4651 */
4652 if (compact_result == COMPACT_SKIPPED ||
4653 compact_result == COMPACT_DEFERRED)
4654 goto nopage;
4655
4656 /*
4657 * Looks like reclaim/compaction is worth trying, but
4658 * sync compaction could be very expensive, so keep
4659 * using async compaction.
4660 */
4661 compact_priority = INIT_COMPACT_PRIORITY;
4662 }
4663 }
4664
4665retry:
4666 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4667 if (alloc_flags & ALLOC_KSWAPD)
4668 wake_all_kswapds(order, gfp_mask, ac);
4669
4670 reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
4671 if (reserve_flags)
4672 alloc_flags = current_alloc_flags(gfp_mask, reserve_flags);
4673
4674 /*
4675 * Reset the nodemask and zonelist iterators if memory policies can be
4676 * ignored. These allocations are high priority and system rather than
4677 * user oriented.
4678 */
4679 if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
4680 ac->nodemask = NULL;
4681 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4682 ac->highest_zoneidx, ac->nodemask);
4683 }
4684
4685 /* Attempt with potentially adjusted zonelist and alloc_flags */
4686 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4687 if (page)
4688 goto got_pg;
4689
4690 /* Caller is not willing to reclaim, we can't balance anything */
4691 if (!can_direct_reclaim)
4692 goto nopage;
4693
4694 /* Avoid recursion of direct reclaim */
4695 if (current->flags & PF_MEMALLOC)
4696 goto nopage;
4697
4698 /* Try direct reclaim and then allocating */
4699 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
4700 &did_some_progress);
4701 if (page)
4702 goto got_pg;
4703
4704 /* Try direct compaction and then allocating */
4705 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
4706 compact_priority, &compact_result);
4707 if (page)
4708 goto got_pg;
4709
4710 /* Do not loop if specifically requested */
4711 if (gfp_mask & __GFP_NORETRY)
4712 goto nopage;
4713
4714 /*
4715 * Do not retry costly high order allocations unless they are
4716 * __GFP_RETRY_MAYFAIL
4717 */
4718 if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
4719 goto nopage;
4720
4721 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
4722 did_some_progress > 0, &no_progress_loops))
4723 goto retry;
4724
4725 /*
4726 * It doesn't make any sense to retry for the compaction if the order-0
4727 * reclaim is not able to make any progress because the current
4728 * implementation of the compaction depends on the sufficient amount
4729 * of free memory (see __compaction_suitable)
4730 */
4731 if (did_some_progress > 0 &&
4732 should_compact_retry(ac, order, alloc_flags,
4733 compact_result, &compact_priority,
4734 &compaction_retries))
4735 goto retry;
4736
4737
4738 /* Deal with possible cpuset update races before we start OOM killing */
4739 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4740 goto retry_cpuset;
4741
4742 /* Reclaim has failed us, start killing things */
4743 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
4744 if (page)
4745 goto got_pg;
4746
4747 /* Avoid allocations with no watermarks from looping endlessly */
4748 if (tsk_is_oom_victim(current) &&
4749 (alloc_flags & ALLOC_OOM ||
4750 (gfp_mask & __GFP_NOMEMALLOC)))
4751 goto nopage;
4752
4753 /* Retry as long as the OOM killer is making progress */
4754 if (did_some_progress) {
4755 no_progress_loops = 0;
4756 goto retry;
4757 }
4758
4759nopage:
4760 /* Deal with possible cpuset update races before we fail */
4761 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4762 goto retry_cpuset;
4763
4764 /*
4765 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4766 * we always retry
4767 */
4768 if (gfp_mask & __GFP_NOFAIL) {
4769 /*
4770 * All existing users of the __GFP_NOFAIL are blockable, so warn
4771 * of any new users that actually require GFP_NOWAIT
4772 */
4773 if (WARN_ON_ONCE(!can_direct_reclaim))
4774 goto fail;
4775
4776 /*
4777 * PF_MEMALLOC request from this context is rather bizarre
4778 * because we cannot reclaim anything and only can loop waiting
4779 * for somebody to do a work for us
4780 */
4781 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
4782
4783 /*
4784 * non failing costly orders are a hard requirement which we
4785 * are not prepared for much so let's warn about these users
4786 * so that we can identify them and convert them to something
4787 * else.
4788 */
4789 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
4790
4791 /*
4792 * Help non-failing allocations by giving them access to memory
4793 * reserves but do not use ALLOC_NO_WATERMARKS because this
4794 * could deplete whole memory reserves which would just make
4795 * the situation worse
4796 */
4797 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
4798 if (page)
4799 goto got_pg;
4800
4801 cond_resched();
4802 goto retry;
4803 }
4804fail:
4805 warn_alloc(gfp_mask, ac->nodemask,
4806 "page allocation failure: order:%u", order);
4807got_pg:
4808 return page;
4809}
4810
4811static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
4812 int preferred_nid, nodemask_t *nodemask,
4813 struct alloc_context *ac, gfp_t *alloc_mask,
4814 unsigned int *alloc_flags)
4815{
4816 ac->highest_zoneidx = gfp_zone(gfp_mask);
4817 ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
4818 ac->nodemask = nodemask;
4819 ac->migratetype = gfp_migratetype(gfp_mask);
4820
4821 if (cpusets_enabled()) {
4822 *alloc_mask |= __GFP_HARDWALL;
4823 /*
4824 * When we are in the interrupt context, it is irrelevant
4825 * to the current task context. It means that any node ok.
4826 */
4827 if (!in_interrupt() && !ac->nodemask)
4828 ac->nodemask = &cpuset_current_mems_allowed;
4829 else
4830 *alloc_flags |= ALLOC_CPUSET;
4831 }
4832
4833 fs_reclaim_acquire(gfp_mask);
4834 fs_reclaim_release(gfp_mask);
4835
4836 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
4837
4838 if (should_fail_alloc_page(gfp_mask, order))
4839 return false;
4840
4841 *alloc_flags = current_alloc_flags(gfp_mask, *alloc_flags);
4842
4843 return true;
4844}
4845
4846/* Determine whether to spread dirty pages and what the first usable zone */
4847static inline void finalise_ac(gfp_t gfp_mask, struct alloc_context *ac)
4848{
4849 /* Dirty zone balancing only done in the fast path */
4850 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
4851
4852 /*
4853 * The preferred zone is used for statistics but crucially it is
4854 * also used as the starting point for the zonelist iterator. It
4855 * may get reset for allocations that ignore memory policies.
4856 */
4857 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4858 ac->highest_zoneidx, ac->nodemask);
4859}
4860
4861/*
4862 * This is the 'heart' of the zoned buddy allocator.
4863 */
4864struct page *
4865__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
4866 nodemask_t *nodemask)
4867{
4868 struct page *page;
4869 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4870 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
4871 struct alloc_context ac = { };
4872
4873 /*
4874 * There are several places where we assume that the order value is sane
4875 * so bail out early if the request is out of bound.
4876 */
4877 if (unlikely(order >= MAX_ORDER)) {
4878 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4879 return NULL;
4880 }
4881
4882 gfp_mask &= gfp_allowed_mask;
4883 alloc_mask = gfp_mask;
4884 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
4885 return NULL;
4886
4887 finalise_ac(gfp_mask, &ac);
4888
4889 /*
4890 * Forbid the first pass from falling back to types that fragment
4891 * memory until all local zones are considered.
4892 */
4893 alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp_mask);
4894
4895 /* First allocation attempt */
4896 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
4897 if (likely(page))
4898 goto out;
4899
4900 /*
4901 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4902 * resp. GFP_NOIO which has to be inherited for all allocation requests
4903 * from a particular context which has been marked by
4904 * memalloc_no{fs,io}_{save,restore}.
4905 */
4906 alloc_mask = current_gfp_context(gfp_mask);
4907 ac.spread_dirty_pages = false;
4908
4909 /*
4910 * Restore the original nodemask if it was potentially replaced with
4911 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4912 */
4913 ac.nodemask = nodemask;
4914
4915 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
4916
4917out:
4918 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
4919 unlikely(__memcg_kmem_charge_page(page, gfp_mask, order) != 0)) {
4920 __free_pages(page, order);
4921 page = NULL;
4922 }
4923
4924 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
4925
4926 return page;
4927}
4928EXPORT_SYMBOL(__alloc_pages_nodemask);
4929
4930/*
4931 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
4932 * address cannot represent highmem pages. Use alloc_pages and then kmap if
4933 * you need to access high mem.
4934 */
4935unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
4936{
4937 struct page *page;
4938
4939 page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order);
4940 if (!page)
4941 return 0;
4942 return (unsigned long) page_address(page);
4943}
4944EXPORT_SYMBOL(__get_free_pages);
4945
4946unsigned long get_zeroed_page(gfp_t gfp_mask)
4947{
4948 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
4949}
4950EXPORT_SYMBOL(get_zeroed_page);
4951
4952static inline void free_the_page(struct page *page, unsigned int order)
4953{
4954 if (order == 0) /* Via pcp? */
4955 free_unref_page(page);
4956 else
4957 __free_pages_ok(page, order);
4958}
4959
4960void __free_pages(struct page *page, unsigned int order)
4961{
4962 if (put_page_testzero(page))
4963 free_the_page(page, order);
4964}
4965EXPORT_SYMBOL(__free_pages);
4966
4967void free_pages(unsigned long addr, unsigned int order)
4968{
4969 if (addr != 0) {
4970 VM_BUG_ON(!virt_addr_valid((void *)addr));
4971 __free_pages(virt_to_page((void *)addr), order);
4972 }
4973}
4974
4975EXPORT_SYMBOL(free_pages);
4976
4977/*
4978 * Page Fragment:
4979 * An arbitrary-length arbitrary-offset area of memory which resides
4980 * within a 0 or higher order page. Multiple fragments within that page
4981 * are individually refcounted, in the page's reference counter.
4982 *
4983 * The page_frag functions below provide a simple allocation framework for
4984 * page fragments. This is used by the network stack and network device
4985 * drivers to provide a backing region of memory for use as either an
4986 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4987 */
4988static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
4989 gfp_t gfp_mask)
4990{
4991 struct page *page = NULL;
4992 gfp_t gfp = gfp_mask;
4993
4994#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4995 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
4996 __GFP_NOMEMALLOC;
4997 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
4998 PAGE_FRAG_CACHE_MAX_ORDER);
4999 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
5000#endif
5001 if (unlikely(!page))
5002 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
5003
5004 nc->va = page ? page_address(page) : NULL;
5005
5006 return page;
5007}
5008
5009void __page_frag_cache_drain(struct page *page, unsigned int count)
5010{
5011 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
5012
5013 if (page_ref_sub_and_test(page, count))
5014 free_the_page(page, compound_order(page));
5015}
5016EXPORT_SYMBOL(__page_frag_cache_drain);
5017
5018void *page_frag_alloc(struct page_frag_cache *nc,
5019 unsigned int fragsz, gfp_t gfp_mask)
5020{
5021 unsigned int size = PAGE_SIZE;
5022 struct page *page;
5023 int offset;
5024
5025 if (unlikely(!nc->va)) {
5026refill:
5027 page = __page_frag_cache_refill(nc, gfp_mask);
5028 if (!page)
5029 return NULL;
5030
5031#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5032 /* if size can vary use size else just use PAGE_SIZE */
5033 size = nc->size;
5034#endif
5035 /* Even if we own the page, we do not use atomic_set().
5036 * This would break get_page_unless_zero() users.
5037 */
5038 page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE);
5039
5040 /* reset page count bias and offset to start of new frag */
5041 nc->pfmemalloc = page_is_pfmemalloc(page);
5042 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
5043 nc->offset = size;
5044 }
5045
5046 offset = nc->offset - fragsz;
5047 if (unlikely(offset < 0)) {
5048 page = virt_to_page(nc->va);
5049
5050 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
5051 goto refill;
5052
5053#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5054 /* if size can vary use size else just use PAGE_SIZE */
5055 size = nc->size;
5056#endif
5057 /* OK, page count is 0, we can safely set it */
5058 set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1);
5059
5060 /* reset page count bias and offset to start of new frag */
5061 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
5062 offset = size - fragsz;
5063 }
5064
5065 nc->pagecnt_bias--;
5066 nc->offset = offset;
5067
5068 return nc->va + offset;
5069}
5070EXPORT_SYMBOL(page_frag_alloc);
5071
5072/*
5073 * Frees a page fragment allocated out of either a compound or order 0 page.
5074 */
5075void page_frag_free(void *addr)
5076{
5077 struct page *page = virt_to_head_page(addr);
5078
5079 if (unlikely(put_page_testzero(page)))
5080 free_the_page(page, compound_order(page));
5081}
5082EXPORT_SYMBOL(page_frag_free);
5083
5084static void *make_alloc_exact(unsigned long addr, unsigned int order,
5085 size_t size)
5086{
5087 if (addr) {
5088 unsigned long alloc_end = addr + (PAGE_SIZE << order);
5089 unsigned long used = addr + PAGE_ALIGN(size);
5090
5091 split_page(virt_to_page((void *)addr), order);
5092 while (used < alloc_end) {
5093 free_page(used);
5094 used += PAGE_SIZE;
5095 }
5096 }
5097 return (void *)addr;
5098}
5099
5100/**
5101 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5102 * @size: the number of bytes to allocate
5103 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5104 *
5105 * This function is similar to alloc_pages(), except that it allocates the
5106 * minimum number of pages to satisfy the request. alloc_pages() can only
5107 * allocate memory in power-of-two pages.
5108 *
5109 * This function is also limited by MAX_ORDER.
5110 *
5111 * Memory allocated by this function must be released by free_pages_exact().
5112 *
5113 * Return: pointer to the allocated area or %NULL in case of error.
5114 */
5115void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
5116{
5117 unsigned int order = get_order(size);
5118 unsigned long addr;
5119
5120 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5121 gfp_mask &= ~__GFP_COMP;
5122
5123 addr = __get_free_pages(gfp_mask, order);
5124 return make_alloc_exact(addr, order, size);
5125}
5126EXPORT_SYMBOL(alloc_pages_exact);
5127
5128/**
5129 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5130 * pages on a node.
5131 * @nid: the preferred node ID where memory should be allocated
5132 * @size: the number of bytes to allocate
5133 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5134 *
5135 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5136 * back.
5137 *
5138 * Return: pointer to the allocated area or %NULL in case of error.
5139 */
5140void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
5141{
5142 unsigned int order = get_order(size);
5143 struct page *p;
5144
5145 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5146 gfp_mask &= ~__GFP_COMP;
5147
5148 p = alloc_pages_node(nid, gfp_mask, order);
5149 if (!p)
5150 return NULL;
5151 return make_alloc_exact((unsigned long)page_address(p), order, size);
5152}
5153
5154/**
5155 * free_pages_exact - release memory allocated via alloc_pages_exact()
5156 * @virt: the value returned by alloc_pages_exact.
5157 * @size: size of allocation, same value as passed to alloc_pages_exact().
5158 *
5159 * Release the memory allocated by a previous call to alloc_pages_exact.
5160 */
5161void free_pages_exact(void *virt, size_t size)
5162{
5163 unsigned long addr = (unsigned long)virt;
5164 unsigned long end = addr + PAGE_ALIGN(size);
5165
5166 while (addr < end) {
5167 free_page(addr);
5168 addr += PAGE_SIZE;
5169 }
5170}
5171EXPORT_SYMBOL(free_pages_exact);
5172
5173/**
5174 * nr_free_zone_pages - count number of pages beyond high watermark
5175 * @offset: The zone index of the highest zone
5176 *
5177 * nr_free_zone_pages() counts the number of pages which are beyond the
5178 * high watermark within all zones at or below a given zone index. For each
5179 * zone, the number of pages is calculated as:
5180 *
5181 * nr_free_zone_pages = managed_pages - high_pages
5182 *
5183 * Return: number of pages beyond high watermark.
5184 */
5185static unsigned long nr_free_zone_pages(int offset)
5186{
5187 struct zoneref *z;
5188 struct zone *zone;
5189
5190 /* Just pick one node, since fallback list is circular */
5191 unsigned long sum = 0;
5192
5193 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
5194
5195 for_each_zone_zonelist(zone, z, zonelist, offset) {
5196 unsigned long size = zone_managed_pages(zone);
5197 unsigned long high = high_wmark_pages(zone);
5198 if (size > high)
5199 sum += size - high;
5200 }
5201
5202 return sum;
5203}
5204
5205/**
5206 * nr_free_buffer_pages - count number of pages beyond high watermark
5207 *
5208 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5209 * watermark within ZONE_DMA and ZONE_NORMAL.
5210 *
5211 * Return: number of pages beyond high watermark within ZONE_DMA and
5212 * ZONE_NORMAL.
5213 */
5214unsigned long nr_free_buffer_pages(void)
5215{
5216 return nr_free_zone_pages(gfp_zone(GFP_USER));
5217}
5218EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
5219
5220static inline void show_node(struct zone *zone)
5221{
5222 if (IS_ENABLED(CONFIG_NUMA))
5223 printk("Node %d ", zone_to_nid(zone));
5224}
5225
5226long si_mem_available(void)
5227{
5228 long available;
5229 unsigned long pagecache;
5230 unsigned long wmark_low = 0;
5231 unsigned long pages[NR_LRU_LISTS];
5232 unsigned long reclaimable;
5233 struct zone *zone;
5234 int lru;
5235
5236 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
5237 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
5238
5239 for_each_zone(zone)
5240 wmark_low += low_wmark_pages(zone);
5241
5242 /*
5243 * Estimate the amount of memory available for userspace allocations,
5244 * without causing swapping.
5245 */
5246 available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
5247
5248 /*
5249 * Not all the page cache can be freed, otherwise the system will
5250 * start swapping. Assume at least half of the page cache, or the
5251 * low watermark worth of cache, needs to stay.
5252 */
5253 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
5254 pagecache -= min(pagecache / 2, wmark_low);
5255 available += pagecache;
5256
5257 /*
5258 * Part of the reclaimable slab and other kernel memory consists of
5259 * items that are in use, and cannot be freed. Cap this estimate at the
5260 * low watermark.
5261 */
5262 reclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) +
5263 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE);
5264 available += reclaimable - min(reclaimable / 2, wmark_low);
5265
5266 if (available < 0)
5267 available = 0;
5268 return available;
5269}
5270EXPORT_SYMBOL_GPL(si_mem_available);
5271
5272void si_meminfo(struct sysinfo *val)
5273{
5274 val->totalram = totalram_pages();
5275 val->sharedram = global_node_page_state(NR_SHMEM);
5276 val->freeram = global_zone_page_state(NR_FREE_PAGES);
5277 val->bufferram = nr_blockdev_pages();
5278 val->totalhigh = totalhigh_pages();
5279 val->freehigh = nr_free_highpages();
5280 val->mem_unit = PAGE_SIZE;
5281}
5282
5283EXPORT_SYMBOL(si_meminfo);
5284
5285#ifdef CONFIG_NUMA
5286void si_meminfo_node(struct sysinfo *val, int nid)
5287{
5288 int zone_type; /* needs to be signed */
5289 unsigned long managed_pages = 0;
5290 unsigned long managed_highpages = 0;
5291 unsigned long free_highpages = 0;
5292 pg_data_t *pgdat = NODE_DATA(nid);
5293
5294 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
5295 managed_pages += zone_managed_pages(&pgdat->node_zones[zone_type]);
5296 val->totalram = managed_pages;
5297 val->sharedram = node_page_state(pgdat, NR_SHMEM);
5298 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
5299#ifdef CONFIG_HIGHMEM
5300 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
5301 struct zone *zone = &pgdat->node_zones[zone_type];
5302
5303 if (is_highmem(zone)) {
5304 managed_highpages += zone_managed_pages(zone);
5305 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
5306 }
5307 }
5308 val->totalhigh = managed_highpages;
5309 val->freehigh = free_highpages;
5310#else
5311 val->totalhigh = managed_highpages;
5312 val->freehigh = free_highpages;
5313#endif
5314 val->mem_unit = PAGE_SIZE;
5315}
5316#endif
5317
5318/*
5319 * Determine whether the node should be displayed or not, depending on whether
5320 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5321 */
5322static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
5323{
5324 if (!(flags & SHOW_MEM_FILTER_NODES))
5325 return false;
5326
5327 /*
5328 * no node mask - aka implicit memory numa policy. Do not bother with
5329 * the synchronization - read_mems_allowed_begin - because we do not
5330 * have to be precise here.
5331 */
5332 if (!nodemask)
5333 nodemask = &cpuset_current_mems_allowed;
5334
5335 return !node_isset(nid, *nodemask);
5336}
5337
5338#define K(x) ((x) << (PAGE_SHIFT-10))
5339
5340static void show_migration_types(unsigned char type)
5341{
5342 static const char types[MIGRATE_TYPES] = {
5343 [MIGRATE_UNMOVABLE] = 'U',
5344 [MIGRATE_MOVABLE] = 'M',
5345 [MIGRATE_RECLAIMABLE] = 'E',
5346 [MIGRATE_HIGHATOMIC] = 'H',
5347#ifdef CONFIG_CMA
5348 [MIGRATE_CMA] = 'C',
5349#endif
5350#ifdef CONFIG_MEMORY_ISOLATION
5351 [MIGRATE_ISOLATE] = 'I',
5352#endif
5353 };
5354 char tmp[MIGRATE_TYPES + 1];
5355 char *p = tmp;
5356 int i;
5357
5358 for (i = 0; i < MIGRATE_TYPES; i++) {
5359 if (type & (1 << i))
5360 *p++ = types[i];
5361 }
5362
5363 *p = '\0';
5364 printk(KERN_CONT "(%s) ", tmp);
5365}
5366
5367/*
5368 * Show free area list (used inside shift_scroll-lock stuff)
5369 * We also calculate the percentage fragmentation. We do this by counting the
5370 * memory on each free list with the exception of the first item on the list.
5371 *
5372 * Bits in @filter:
5373 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5374 * cpuset.
5375 */
5376void show_free_areas(unsigned int filter, nodemask_t *nodemask)
5377{
5378 unsigned long free_pcp = 0;
5379 int cpu;
5380 struct zone *zone;
5381 pg_data_t *pgdat;
5382
5383 for_each_populated_zone(zone) {
5384 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5385 continue;
5386
5387 for_each_online_cpu(cpu)
5388 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
5389 }
5390
5391 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5392 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5393 " unevictable:%lu dirty:%lu writeback:%lu\n"
5394 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5395 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5396 " free:%lu free_pcp:%lu free_cma:%lu\n",
5397 global_node_page_state(NR_ACTIVE_ANON),
5398 global_node_page_state(NR_INACTIVE_ANON),
5399 global_node_page_state(NR_ISOLATED_ANON),
5400 global_node_page_state(NR_ACTIVE_FILE),
5401 global_node_page_state(NR_INACTIVE_FILE),
5402 global_node_page_state(NR_ISOLATED_FILE),
5403 global_node_page_state(NR_UNEVICTABLE),
5404 global_node_page_state(NR_FILE_DIRTY),
5405 global_node_page_state(NR_WRITEBACK),
5406 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B),
5407 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B),
5408 global_node_page_state(NR_FILE_MAPPED),
5409 global_node_page_state(NR_SHMEM),
5410 global_zone_page_state(NR_PAGETABLE),
5411 global_zone_page_state(NR_BOUNCE),
5412 global_zone_page_state(NR_FREE_PAGES),
5413 free_pcp,
5414 global_zone_page_state(NR_FREE_CMA_PAGES));
5415
5416 for_each_online_pgdat(pgdat) {
5417 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
5418 continue;
5419
5420 printk("Node %d"
5421 " active_anon:%lukB"
5422 " inactive_anon:%lukB"
5423 " active_file:%lukB"
5424 " inactive_file:%lukB"
5425 " unevictable:%lukB"
5426 " isolated(anon):%lukB"
5427 " isolated(file):%lukB"
5428 " mapped:%lukB"
5429 " dirty:%lukB"
5430 " writeback:%lukB"
5431 " shmem:%lukB"
5432#ifdef CONFIG_TRANSPARENT_HUGEPAGE
5433 " shmem_thp: %lukB"
5434 " shmem_pmdmapped: %lukB"
5435 " anon_thp: %lukB"
5436#endif
5437 " writeback_tmp:%lukB"
5438 " kernel_stack:%lukB"
5439#ifdef CONFIG_SHADOW_CALL_STACK
5440 " shadow_call_stack:%lukB"
5441#endif
5442 " all_unreclaimable? %s"
5443 "\n",
5444 pgdat->node_id,
5445 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
5446 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
5447 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
5448 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
5449 K(node_page_state(pgdat, NR_UNEVICTABLE)),
5450 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
5451 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
5452 K(node_page_state(pgdat, NR_FILE_MAPPED)),
5453 K(node_page_state(pgdat, NR_FILE_DIRTY)),
5454 K(node_page_state(pgdat, NR_WRITEBACK)),
5455 K(node_page_state(pgdat, NR_SHMEM)),
5456#ifdef CONFIG_TRANSPARENT_HUGEPAGE
5457 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
5458 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
5459 * HPAGE_PMD_NR),
5460 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
5461#endif
5462 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
5463 node_page_state(pgdat, NR_KERNEL_STACK_KB),
5464#ifdef CONFIG_SHADOW_CALL_STACK
5465 node_page_state(pgdat, NR_KERNEL_SCS_KB),
5466#endif
5467 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
5468 "yes" : "no");
5469 }
5470
5471 for_each_populated_zone(zone) {
5472 int i;
5473
5474 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5475 continue;
5476
5477 free_pcp = 0;
5478 for_each_online_cpu(cpu)
5479 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
5480
5481 show_node(zone);
5482 printk(KERN_CONT
5483 "%s"
5484 " free:%lukB"
5485 " min:%lukB"
5486 " low:%lukB"
5487 " high:%lukB"
5488 " reserved_highatomic:%luKB"
5489 " active_anon:%lukB"
5490 " inactive_anon:%lukB"
5491 " active_file:%lukB"
5492 " inactive_file:%lukB"
5493 " unevictable:%lukB"
5494 " writepending:%lukB"
5495 " present:%lukB"
5496 " managed:%lukB"
5497 " mlocked:%lukB"
5498 " pagetables:%lukB"
5499 " bounce:%lukB"
5500 " free_pcp:%lukB"
5501 " local_pcp:%ukB"
5502 " free_cma:%lukB"
5503 "\n",
5504 zone->name,
5505 K(zone_page_state(zone, NR_FREE_PAGES)),
5506 K(min_wmark_pages(zone)),
5507 K(low_wmark_pages(zone)),
5508 K(high_wmark_pages(zone)),
5509 K(zone->nr_reserved_highatomic),
5510 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
5511 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
5512 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
5513 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
5514 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
5515 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
5516 K(zone->present_pages),
5517 K(zone_managed_pages(zone)),
5518 K(zone_page_state(zone, NR_MLOCK)),
5519 K(zone_page_state(zone, NR_PAGETABLE)),
5520 K(zone_page_state(zone, NR_BOUNCE)),
5521 K(free_pcp),
5522 K(this_cpu_read(zone->pageset->pcp.count)),
5523 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
5524 printk("lowmem_reserve[]:");
5525 for (i = 0; i < MAX_NR_ZONES; i++)
5526 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
5527 printk(KERN_CONT "\n");
5528 }
5529
5530 for_each_populated_zone(zone) {
5531 unsigned int order;
5532 unsigned long nr[MAX_ORDER], flags, total = 0;
5533 unsigned char types[MAX_ORDER];
5534
5535 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5536 continue;
5537 show_node(zone);
5538 printk(KERN_CONT "%s: ", zone->name);
5539
5540 spin_lock_irqsave(&zone->lock, flags);
5541 for (order = 0; order < MAX_ORDER; order++) {
5542 struct free_area *area = &zone->free_area[order];
5543 int type;
5544
5545 nr[order] = area->nr_free;
5546 total += nr[order] << order;
5547
5548 types[order] = 0;
5549 for (type = 0; type < MIGRATE_TYPES; type++) {
5550 if (!free_area_empty(area, type))
5551 types[order] |= 1 << type;
5552 }
5553 }
5554 spin_unlock_irqrestore(&zone->lock, flags);
5555 for (order = 0; order < MAX_ORDER; order++) {
5556 printk(KERN_CONT "%lu*%lukB ",
5557 nr[order], K(1UL) << order);
5558 if (nr[order])
5559 show_migration_types(types[order]);
5560 }
5561 printk(KERN_CONT "= %lukB\n", K(total));
5562 }
5563
5564 hugetlb_show_meminfo();
5565
5566 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
5567
5568 show_swap_cache_info();
5569}
5570
5571static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
5572{
5573 zoneref->zone = zone;
5574 zoneref->zone_idx = zone_idx(zone);
5575}
5576
5577/*
5578 * Builds allocation fallback zone lists.
5579 *
5580 * Add all populated zones of a node to the zonelist.
5581 */
5582static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
5583{
5584 struct zone *zone;
5585 enum zone_type zone_type = MAX_NR_ZONES;
5586 int nr_zones = 0;
5587
5588 do {
5589 zone_type--;
5590 zone = pgdat->node_zones + zone_type;
5591 if (managed_zone(zone)) {
5592 zoneref_set_zone(zone, &zonerefs[nr_zones++]);
5593 check_highest_zone(zone_type);
5594 }
5595 } while (zone_type);
5596
5597 return nr_zones;
5598}
5599
5600#ifdef CONFIG_NUMA
5601
5602static int __parse_numa_zonelist_order(char *s)
5603{
5604 /*
5605 * We used to support different zonlists modes but they turned
5606 * out to be just not useful. Let's keep the warning in place
5607 * if somebody still use the cmd line parameter so that we do
5608 * not fail it silently
5609 */
5610 if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
5611 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
5612 return -EINVAL;
5613 }
5614 return 0;
5615}
5616
5617char numa_zonelist_order[] = "Node";
5618
5619/*
5620 * sysctl handler for numa_zonelist_order
5621 */
5622int numa_zonelist_order_handler(struct ctl_table *table, int write,
5623 void *buffer, size_t *length, loff_t *ppos)
5624{
5625 if (write)
5626 return __parse_numa_zonelist_order(buffer);
5627 return proc_dostring(table, write, buffer, length, ppos);
5628}
5629
5630
5631#define MAX_NODE_LOAD (nr_online_nodes)
5632static int node_load[MAX_NUMNODES];
5633
5634/**
5635 * find_next_best_node - find the next node that should appear in a given node's fallback list
5636 * @node: node whose fallback list we're appending
5637 * @used_node_mask: nodemask_t of already used nodes
5638 *
5639 * We use a number of factors to determine which is the next node that should
5640 * appear on a given node's fallback list. The node should not have appeared
5641 * already in @node's fallback list, and it should be the next closest node
5642 * according to the distance array (which contains arbitrary distance values
5643 * from each node to each node in the system), and should also prefer nodes
5644 * with no CPUs, since presumably they'll have very little allocation pressure
5645 * on them otherwise.
5646 *
5647 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5648 */
5649static int find_next_best_node(int node, nodemask_t *used_node_mask)
5650{
5651 int n, val;
5652 int min_val = INT_MAX;
5653 int best_node = NUMA_NO_NODE;
5654 const struct cpumask *tmp = cpumask_of_node(0);
5655
5656 /* Use the local node if we haven't already */
5657 if (!node_isset(node, *used_node_mask)) {
5658 node_set(node, *used_node_mask);
5659 return node;
5660 }
5661
5662 for_each_node_state(n, N_MEMORY) {
5663
5664 /* Don't want a node to appear more than once */
5665 if (node_isset(n, *used_node_mask))
5666 continue;
5667
5668 /* Use the distance array to find the distance */
5669 val = node_distance(node, n);
5670
5671 /* Penalize nodes under us ("prefer the next node") */
5672 val += (n < node);
5673
5674 /* Give preference to headless and unused nodes */
5675 tmp = cpumask_of_node(n);
5676 if (!cpumask_empty(tmp))
5677 val += PENALTY_FOR_NODE_WITH_CPUS;
5678
5679 /* Slight preference for less loaded node */
5680 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
5681 val += node_load[n];
5682
5683 if (val < min_val) {
5684 min_val = val;
5685 best_node = n;
5686 }
5687 }
5688
5689 if (best_node >= 0)
5690 node_set(best_node, *used_node_mask);
5691
5692 return best_node;
5693}
5694
5695
5696/*
5697 * Build zonelists ordered by node and zones within node.
5698 * This results in maximum locality--normal zone overflows into local
5699 * DMA zone, if any--but risks exhausting DMA zone.
5700 */
5701static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
5702 unsigned nr_nodes)
5703{
5704 struct zoneref *zonerefs;
5705 int i;
5706
5707 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5708
5709 for (i = 0; i < nr_nodes; i++) {
5710 int nr_zones;
5711
5712 pg_data_t *node = NODE_DATA(node_order[i]);
5713
5714 nr_zones = build_zonerefs_node(node, zonerefs);
5715 zonerefs += nr_zones;
5716 }
5717 zonerefs->zone = NULL;
5718 zonerefs->zone_idx = 0;
5719}
5720
5721/*
5722 * Build gfp_thisnode zonelists
5723 */
5724static void build_thisnode_zonelists(pg_data_t *pgdat)
5725{
5726 struct zoneref *zonerefs;
5727 int nr_zones;
5728
5729 zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
5730 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5731 zonerefs += nr_zones;
5732 zonerefs->zone = NULL;
5733 zonerefs->zone_idx = 0;
5734}
5735
5736/*
5737 * Build zonelists ordered by zone and nodes within zones.
5738 * This results in conserving DMA zone[s] until all Normal memory is
5739 * exhausted, but results in overflowing to remote node while memory
5740 * may still exist in local DMA zone.
5741 */
5742
5743static void build_zonelists(pg_data_t *pgdat)
5744{
5745 static int node_order[MAX_NUMNODES];
5746 int node, load, nr_nodes = 0;
5747 nodemask_t used_mask = NODE_MASK_NONE;
5748 int local_node, prev_node;
5749
5750 /* NUMA-aware ordering of nodes */
5751 local_node = pgdat->node_id;
5752 load = nr_online_nodes;
5753 prev_node = local_node;
5754
5755 memset(node_order, 0, sizeof(node_order));
5756 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
5757 /*
5758 * We don't want to pressure a particular node.
5759 * So adding penalty to the first node in same
5760 * distance group to make it round-robin.
5761 */
5762 if (node_distance(local_node, node) !=
5763 node_distance(local_node, prev_node))
5764 node_load[node] = load;
5765
5766 node_order[nr_nodes++] = node;
5767 prev_node = node;
5768 load--;
5769 }
5770
5771 build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
5772 build_thisnode_zonelists(pgdat);
5773}
5774
5775#ifdef CONFIG_HAVE_MEMORYLESS_NODES
5776/*
5777 * Return node id of node used for "local" allocations.
5778 * I.e., first node id of first zone in arg node's generic zonelist.
5779 * Used for initializing percpu 'numa_mem', which is used primarily
5780 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5781 */
5782int local_memory_node(int node)
5783{
5784 struct zoneref *z;
5785
5786 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
5787 gfp_zone(GFP_KERNEL),
5788 NULL);
5789 return zone_to_nid(z->zone);
5790}
5791#endif
5792
5793static void setup_min_unmapped_ratio(void);
5794static void setup_min_slab_ratio(void);
5795#else /* CONFIG_NUMA */
5796
5797static void build_zonelists(pg_data_t *pgdat)
5798{
5799 int node, local_node;
5800 struct zoneref *zonerefs;
5801 int nr_zones;
5802
5803 local_node = pgdat->node_id;
5804
5805 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5806 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5807 zonerefs += nr_zones;
5808
5809 /*
5810 * Now we build the zonelist so that it contains the zones
5811 * of all the other nodes.
5812 * We don't want to pressure a particular node, so when
5813 * building the zones for node N, we make sure that the
5814 * zones coming right after the local ones are those from
5815 * node N+1 (modulo N)
5816 */
5817 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
5818 if (!node_online(node))
5819 continue;
5820 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5821 zonerefs += nr_zones;
5822 }
5823 for (node = 0; node < local_node; node++) {
5824 if (!node_online(node))
5825 continue;
5826 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5827 zonerefs += nr_zones;
5828 }
5829
5830 zonerefs->zone = NULL;
5831 zonerefs->zone_idx = 0;
5832}
5833
5834#endif /* CONFIG_NUMA */
5835
5836/*
5837 * Boot pageset table. One per cpu which is going to be used for all
5838 * zones and all nodes. The parameters will be set in such a way
5839 * that an item put on a list will immediately be handed over to
5840 * the buddy list. This is safe since pageset manipulation is done
5841 * with interrupts disabled.
5842 *
5843 * The boot_pagesets must be kept even after bootup is complete for
5844 * unused processors and/or zones. They do play a role for bootstrapping
5845 * hotplugged processors.
5846 *
5847 * zoneinfo_show() and maybe other functions do
5848 * not check if the processor is online before following the pageset pointer.
5849 * Other parts of the kernel may not check if the zone is available.
5850 */
5851static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
5852static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
5853static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
5854
5855static void __build_all_zonelists(void *data)
5856{
5857 int nid;
5858 int __maybe_unused cpu;
5859 pg_data_t *self = data;
5860 static DEFINE_SPINLOCK(lock);
5861
5862 spin_lock(&lock);
5863
5864#ifdef CONFIG_NUMA
5865 memset(node_load, 0, sizeof(node_load));
5866#endif
5867
5868 /*
5869 * This node is hotadded and no memory is yet present. So just
5870 * building zonelists is fine - no need to touch other nodes.
5871 */
5872 if (self && !node_online(self->node_id)) {
5873 build_zonelists(self);
5874 } else {
5875 for_each_online_node(nid) {
5876 pg_data_t *pgdat = NODE_DATA(nid);
5877
5878 build_zonelists(pgdat);
5879 }
5880
5881#ifdef CONFIG_HAVE_MEMORYLESS_NODES
5882 /*
5883 * We now know the "local memory node" for each node--
5884 * i.e., the node of the first zone in the generic zonelist.
5885 * Set up numa_mem percpu variable for on-line cpus. During
5886 * boot, only the boot cpu should be on-line; we'll init the
5887 * secondary cpus' numa_mem as they come on-line. During
5888 * node/memory hotplug, we'll fixup all on-line cpus.
5889 */
5890 for_each_online_cpu(cpu)
5891 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
5892#endif
5893 }
5894
5895 spin_unlock(&lock);
5896}
5897
5898static noinline void __init
5899build_all_zonelists_init(void)
5900{
5901 int cpu;
5902
5903 __build_all_zonelists(NULL);
5904
5905 /*
5906 * Initialize the boot_pagesets that are going to be used
5907 * for bootstrapping processors. The real pagesets for
5908 * each zone will be allocated later when the per cpu
5909 * allocator is available.
5910 *
5911 * boot_pagesets are used also for bootstrapping offline
5912 * cpus if the system is already booted because the pagesets
5913 * are needed to initialize allocators on a specific cpu too.
5914 * F.e. the percpu allocator needs the page allocator which
5915 * needs the percpu allocator in order to allocate its pagesets
5916 * (a chicken-egg dilemma).
5917 */
5918 for_each_possible_cpu(cpu)
5919 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
5920
5921 mminit_verify_zonelist();
5922 cpuset_init_current_mems_allowed();
5923}
5924
5925/*
5926 * unless system_state == SYSTEM_BOOTING.
5927 *
5928 * __ref due to call of __init annotated helper build_all_zonelists_init
5929 * [protected by SYSTEM_BOOTING].
5930 */
5931void __ref build_all_zonelists(pg_data_t *pgdat)
5932{
5933 unsigned long vm_total_pages;
5934
5935 if (system_state == SYSTEM_BOOTING) {
5936 build_all_zonelists_init();
5937 } else {
5938 __build_all_zonelists(pgdat);
5939 /* cpuset refresh routine should be here */
5940 }
5941 /* Get the number of free pages beyond high watermark in all zones. */
5942 vm_total_pages = nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
5943 /*
5944 * Disable grouping by mobility if the number of pages in the
5945 * system is too low to allow the mechanism to work. It would be
5946 * more accurate, but expensive to check per-zone. This check is
5947 * made on memory-hotadd so a system can start with mobility
5948 * disabled and enable it later
5949 */
5950 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5951 page_group_by_mobility_disabled = 1;
5952 else
5953 page_group_by_mobility_disabled = 0;
5954
5955 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
5956 nr_online_nodes,
5957 page_group_by_mobility_disabled ? "off" : "on",
5958 vm_total_pages);
5959#ifdef CONFIG_NUMA
5960 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5961#endif
5962}
5963
5964/* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
5965static bool __meminit
5966overlap_memmap_init(unsigned long zone, unsigned long *pfn)
5967{
5968 static struct memblock_region *r;
5969
5970 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5971 if (!r || *pfn >= memblock_region_memory_end_pfn(r)) {
5972 for_each_memblock(memory, r) {
5973 if (*pfn < memblock_region_memory_end_pfn(r))
5974 break;
5975 }
5976 }
5977 if (*pfn >= memblock_region_memory_base_pfn(r) &&
5978 memblock_is_mirror(r)) {
5979 *pfn = memblock_region_memory_end_pfn(r);
5980 return true;
5981 }
5982 }
5983 return false;
5984}
5985
5986/*
5987 * Initially all pages are reserved - free ones are freed
5988 * up by memblock_free_all() once the early boot process is
5989 * done. Non-atomic initialization, single-pass.
5990 */
5991void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5992 unsigned long start_pfn, enum meminit_context context,
5993 struct vmem_altmap *altmap)
5994{
5995 unsigned long pfn, end_pfn = start_pfn + size;
5996 struct page *page;
5997
5998 if (highest_memmap_pfn < end_pfn - 1)
5999 highest_memmap_pfn = end_pfn - 1;
6000
6001#ifdef CONFIG_ZONE_DEVICE
6002 /*
6003 * Honor reservation requested by the driver for this ZONE_DEVICE
6004 * memory. We limit the total number of pages to initialize to just
6005 * those that might contain the memory mapping. We will defer the
6006 * ZONE_DEVICE page initialization until after we have released
6007 * the hotplug lock.
6008 */
6009 if (zone == ZONE_DEVICE) {
6010 if (!altmap)
6011 return;
6012
6013 if (start_pfn == altmap->base_pfn)
6014 start_pfn += altmap->reserve;
6015 end_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6016 }
6017#endif
6018
6019 for (pfn = start_pfn; pfn < end_pfn; ) {
6020 /*
6021 * There can be holes in boot-time mem_map[]s handed to this
6022 * function. They do not exist on hotplugged memory.
6023 */
6024 if (context == MEMINIT_EARLY) {
6025 if (overlap_memmap_init(zone, &pfn))
6026 continue;
6027 if (defer_init(nid, pfn, end_pfn))
6028 break;
6029 }
6030
6031 page = pfn_to_page(pfn);
6032 __init_single_page(page, pfn, zone, nid);
6033 if (context == MEMINIT_HOTPLUG)
6034 __SetPageReserved(page);
6035
6036 /*
6037 * Mark the block movable so that blocks are reserved for
6038 * movable at startup. This will force kernel allocations
6039 * to reserve their blocks rather than leaking throughout
6040 * the address space during boot when many long-lived
6041 * kernel allocations are made.
6042 *
6043 * bitmap is created for zone's valid pfn range. but memmap
6044 * can be created for invalid pages (for alignment)
6045 * check here not to call set_pageblock_migratetype() against
6046 * pfn out of zone.
6047 */
6048 if (!(pfn & (pageblock_nr_pages - 1))) {
6049 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
6050 cond_resched();
6051 }
6052 pfn++;
6053 }
6054}
6055
6056#ifdef CONFIG_ZONE_DEVICE
6057void __ref memmap_init_zone_device(struct zone *zone,
6058 unsigned long start_pfn,
6059 unsigned long nr_pages,
6060 struct dev_pagemap *pgmap)
6061{
6062 unsigned long pfn, end_pfn = start_pfn + nr_pages;
6063 struct pglist_data *pgdat = zone->zone_pgdat;
6064 struct vmem_altmap *altmap = pgmap_altmap(pgmap);
6065 unsigned long zone_idx = zone_idx(zone);
6066 unsigned long start = jiffies;
6067 int nid = pgdat->node_id;
6068
6069 if (WARN_ON_ONCE(!pgmap || zone_idx(zone) != ZONE_DEVICE))
6070 return;
6071
6072 /*
6073 * The call to memmap_init_zone should have already taken care
6074 * of the pages reserved for the memmap, so we can just jump to
6075 * the end of that region and start processing the device pages.
6076 */
6077 if (altmap) {
6078 start_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6079 nr_pages = end_pfn - start_pfn;
6080 }
6081
6082 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
6083 struct page *page = pfn_to_page(pfn);
6084
6085 __init_single_page(page, pfn, zone_idx, nid);
6086
6087 /*
6088 * Mark page reserved as it will need to wait for onlining
6089 * phase for it to be fully associated with a zone.
6090 *
6091 * We can use the non-atomic __set_bit operation for setting
6092 * the flag as we are still initializing the pages.
6093 */
6094 __SetPageReserved(page);
6095
6096 /*
6097 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6098 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6099 * ever freed or placed on a driver-private list.
6100 */
6101 page->pgmap = pgmap;
6102 page->zone_device_data = NULL;
6103
6104 /*
6105 * Mark the block movable so that blocks are reserved for
6106 * movable at startup. This will force kernel allocations
6107 * to reserve their blocks rather than leaking throughout
6108 * the address space during boot when many long-lived
6109 * kernel allocations are made.
6110 *
6111 * bitmap is created for zone's valid pfn range. but memmap
6112 * can be created for invalid pages (for alignment)
6113 * check here not to call set_pageblock_migratetype() against
6114 * pfn out of zone.
6115 *
6116 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6117 * because this is done early in section_activate()
6118 */
6119 if (!(pfn & (pageblock_nr_pages - 1))) {
6120 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
6121 cond_resched();
6122 }
6123 }
6124
6125 pr_info("%s initialised %lu pages in %ums\n", __func__,
6126 nr_pages, jiffies_to_msecs(jiffies - start));
6127}
6128
6129#endif
6130static void __meminit zone_init_free_lists(struct zone *zone)
6131{
6132 unsigned int order, t;
6133 for_each_migratetype_order(order, t) {
6134 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
6135 zone->free_area[order].nr_free = 0;
6136 }
6137}
6138
6139void __meminit __weak memmap_init(unsigned long size, int nid,
6140 unsigned long zone,
6141 unsigned long range_start_pfn)
6142{
6143 unsigned long start_pfn, end_pfn;
6144 unsigned long range_end_pfn = range_start_pfn + size;
6145 int i;
6146
6147 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6148 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
6149 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
6150
6151 if (end_pfn > start_pfn) {
6152 size = end_pfn - start_pfn;
6153 memmap_init_zone(size, nid, zone, start_pfn,
6154 MEMINIT_EARLY, NULL);
6155 }
6156 }
6157}
6158
6159static int zone_batchsize(struct zone *zone)
6160{
6161#ifdef CONFIG_MMU
6162 int batch;
6163
6164 /*
6165 * The per-cpu-pages pools are set to around 1000th of the
6166 * size of the zone.
6167 */
6168 batch = zone_managed_pages(zone) / 1024;
6169 /* But no more than a meg. */
6170 if (batch * PAGE_SIZE > 1024 * 1024)
6171 batch = (1024 * 1024) / PAGE_SIZE;
6172 batch /= 4; /* We effectively *= 4 below */
6173 if (batch < 1)
6174 batch = 1;
6175
6176 /*
6177 * Clamp the batch to a 2^n - 1 value. Having a power
6178 * of 2 value was found to be more likely to have
6179 * suboptimal cache aliasing properties in some cases.
6180 *
6181 * For example if 2 tasks are alternately allocating
6182 * batches of pages, one task can end up with a lot
6183 * of pages of one half of the possible page colors
6184 * and the other with pages of the other colors.
6185 */
6186 batch = rounddown_pow_of_two(batch + batch/2) - 1;
6187
6188 return batch;
6189
6190#else
6191 /* The deferral and batching of frees should be suppressed under NOMMU
6192 * conditions.
6193 *
6194 * The problem is that NOMMU needs to be able to allocate large chunks
6195 * of contiguous memory as there's no hardware page translation to
6196 * assemble apparent contiguous memory from discontiguous pages.
6197 *
6198 * Queueing large contiguous runs of pages for batching, however,
6199 * causes the pages to actually be freed in smaller chunks. As there
6200 * can be a significant delay between the individual batches being
6201 * recycled, this leads to the once large chunks of space being
6202 * fragmented and becoming unavailable for high-order allocations.
6203 */
6204 return 0;
6205#endif
6206}
6207
6208/*
6209 * pcp->high and pcp->batch values are related and dependent on one another:
6210 * ->batch must never be higher then ->high.
6211 * The following function updates them in a safe manner without read side
6212 * locking.
6213 *
6214 * Any new users of pcp->batch and pcp->high should ensure they can cope with
6215 * those fields changing asynchronously (acording to the above rule).
6216 *
6217 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6218 * outside of boot time (or some other assurance that no concurrent updaters
6219 * exist).
6220 */
6221static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
6222 unsigned long batch)
6223{
6224 /* start with a fail safe value for batch */
6225 pcp->batch = 1;
6226 smp_wmb();
6227
6228 /* Update high, then batch, in order */
6229 pcp->high = high;
6230 smp_wmb();
6231
6232 pcp->batch = batch;
6233}
6234
6235/* a companion to pageset_set_high() */
6236static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
6237{
6238 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
6239}
6240
6241static void pageset_init(struct per_cpu_pageset *p)
6242{
6243 struct per_cpu_pages *pcp;
6244 int migratetype;
6245
6246 memset(p, 0, sizeof(*p));
6247
6248 pcp = &p->pcp;
6249 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
6250 INIT_LIST_HEAD(&pcp->lists[migratetype]);
6251}
6252
6253static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
6254{
6255 pageset_init(p);
6256 pageset_set_batch(p, batch);
6257}
6258
6259/*
6260 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
6261 * to the value high for the pageset p.
6262 */
6263static void pageset_set_high(struct per_cpu_pageset *p,
6264 unsigned long high)
6265{
6266 unsigned long batch = max(1UL, high / 4);
6267 if ((high / 4) > (PAGE_SHIFT * 8))
6268 batch = PAGE_SHIFT * 8;
6269
6270 pageset_update(&p->pcp, high, batch);
6271}
6272
6273static void pageset_set_high_and_batch(struct zone *zone,
6274 struct per_cpu_pageset *pcp)
6275{
6276 if (percpu_pagelist_fraction)
6277 pageset_set_high(pcp,
6278 (zone_managed_pages(zone) /
6279 percpu_pagelist_fraction));
6280 else
6281 pageset_set_batch(pcp, zone_batchsize(zone));
6282}
6283
6284static void __meminit zone_pageset_init(struct zone *zone, int cpu)
6285{
6286 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
6287
6288 pageset_init(pcp);
6289 pageset_set_high_and_batch(zone, pcp);
6290}
6291
6292void __meminit setup_zone_pageset(struct zone *zone)
6293{
6294 int cpu;
6295 zone->pageset = alloc_percpu(struct per_cpu_pageset);
6296 for_each_possible_cpu(cpu)
6297 zone_pageset_init(zone, cpu);
6298}
6299
6300/*
6301 * Allocate per cpu pagesets and initialize them.
6302 * Before this call only boot pagesets were available.
6303 */
6304void __init setup_per_cpu_pageset(void)
6305{
6306 struct pglist_data *pgdat;
6307 struct zone *zone;
6308 int __maybe_unused cpu;
6309
6310 for_each_populated_zone(zone)
6311 setup_zone_pageset(zone);
6312
6313#ifdef CONFIG_NUMA
6314 /*
6315 * Unpopulated zones continue using the boot pagesets.
6316 * The numa stats for these pagesets need to be reset.
6317 * Otherwise, they will end up skewing the stats of
6318 * the nodes these zones are associated with.
6319 */
6320 for_each_possible_cpu(cpu) {
6321 struct per_cpu_pageset *pcp = &per_cpu(boot_pageset, cpu);
6322 memset(pcp->vm_numa_stat_diff, 0,
6323 sizeof(pcp->vm_numa_stat_diff));
6324 }
6325#endif
6326
6327 for_each_online_pgdat(pgdat)
6328 pgdat->per_cpu_nodestats =
6329 alloc_percpu(struct per_cpu_nodestat);
6330}
6331
6332static __meminit void zone_pcp_init(struct zone *zone)
6333{
6334 /*
6335 * per cpu subsystem is not up at this point. The following code
6336 * relies on the ability of the linker to provide the
6337 * offset of a (static) per cpu variable into the per cpu area.
6338 */
6339 zone->pageset = &boot_pageset;
6340
6341 if (populated_zone(zone))
6342 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
6343 zone->name, zone->present_pages,
6344 zone_batchsize(zone));
6345}
6346
6347void __meminit init_currently_empty_zone(struct zone *zone,
6348 unsigned long zone_start_pfn,
6349 unsigned long size)
6350{
6351 struct pglist_data *pgdat = zone->zone_pgdat;
6352 int zone_idx = zone_idx(zone) + 1;
6353
6354 if (zone_idx > pgdat->nr_zones)
6355 pgdat->nr_zones = zone_idx;
6356
6357 zone->zone_start_pfn = zone_start_pfn;
6358
6359 mminit_dprintk(MMINIT_TRACE, "memmap_init",
6360 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6361 pgdat->node_id,
6362 (unsigned long)zone_idx(zone),
6363 zone_start_pfn, (zone_start_pfn + size));
6364
6365 zone_init_free_lists(zone);
6366 zone->initialized = 1;
6367}
6368
6369/**
6370 * get_pfn_range_for_nid - Return the start and end page frames for a node
6371 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6372 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6373 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6374 *
6375 * It returns the start and end page frame of a node based on information
6376 * provided by memblock_set_node(). If called for a node
6377 * with no available memory, a warning is printed and the start and end
6378 * PFNs will be 0.
6379 */
6380void __init get_pfn_range_for_nid(unsigned int nid,
6381 unsigned long *start_pfn, unsigned long *end_pfn)
6382{
6383 unsigned long this_start_pfn, this_end_pfn;
6384 int i;
6385
6386 *start_pfn = -1UL;
6387 *end_pfn = 0;
6388
6389 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
6390 *start_pfn = min(*start_pfn, this_start_pfn);
6391 *end_pfn = max(*end_pfn, this_end_pfn);
6392 }
6393
6394 if (*start_pfn == -1UL)
6395 *start_pfn = 0;
6396}
6397
6398/*
6399 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6400 * assumption is made that zones within a node are ordered in monotonic
6401 * increasing memory addresses so that the "highest" populated zone is used
6402 */
6403static void __init find_usable_zone_for_movable(void)
6404{
6405 int zone_index;
6406 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
6407 if (zone_index == ZONE_MOVABLE)
6408 continue;
6409
6410 if (arch_zone_highest_possible_pfn[zone_index] >
6411 arch_zone_lowest_possible_pfn[zone_index])
6412 break;
6413 }
6414
6415 VM_BUG_ON(zone_index == -1);
6416 movable_zone = zone_index;
6417}
6418
6419/*
6420 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6421 * because it is sized independent of architecture. Unlike the other zones,
6422 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6423 * in each node depending on the size of each node and how evenly kernelcore
6424 * is distributed. This helper function adjusts the zone ranges
6425 * provided by the architecture for a given node by using the end of the
6426 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6427 * zones within a node are in order of monotonic increases memory addresses
6428 */
6429static void __init adjust_zone_range_for_zone_movable(int nid,
6430 unsigned long zone_type,
6431 unsigned long node_start_pfn,
6432 unsigned long node_end_pfn,
6433 unsigned long *zone_start_pfn,
6434 unsigned long *zone_end_pfn)
6435{
6436 /* Only adjust if ZONE_MOVABLE is on this node */
6437 if (zone_movable_pfn[nid]) {
6438 /* Size ZONE_MOVABLE */
6439 if (zone_type == ZONE_MOVABLE) {
6440 *zone_start_pfn = zone_movable_pfn[nid];
6441 *zone_end_pfn = min(node_end_pfn,
6442 arch_zone_highest_possible_pfn[movable_zone]);
6443
6444 /* Adjust for ZONE_MOVABLE starting within this range */
6445 } else if (!mirrored_kernelcore &&
6446 *zone_start_pfn < zone_movable_pfn[nid] &&
6447 *zone_end_pfn > zone_movable_pfn[nid]) {
6448 *zone_end_pfn = zone_movable_pfn[nid];
6449
6450 /* Check if this whole range is within ZONE_MOVABLE */
6451 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
6452 *zone_start_pfn = *zone_end_pfn;
6453 }
6454}
6455
6456/*
6457 * Return the number of pages a zone spans in a node, including holes
6458 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6459 */
6460static unsigned long __init zone_spanned_pages_in_node(int nid,
6461 unsigned long zone_type,
6462 unsigned long node_start_pfn,
6463 unsigned long node_end_pfn,
6464 unsigned long *zone_start_pfn,
6465 unsigned long *zone_end_pfn)
6466{
6467 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6468 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6469 /* When hotadd a new node from cpu_up(), the node should be empty */
6470 if (!node_start_pfn && !node_end_pfn)
6471 return 0;
6472
6473 /* Get the start and end of the zone */
6474 *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6475 *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6476 adjust_zone_range_for_zone_movable(nid, zone_type,
6477 node_start_pfn, node_end_pfn,
6478 zone_start_pfn, zone_end_pfn);
6479
6480 /* Check that this node has pages within the zone's required range */
6481 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
6482 return 0;
6483
6484 /* Move the zone boundaries inside the node if necessary */
6485 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
6486 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
6487
6488 /* Return the spanned pages */
6489 return *zone_end_pfn - *zone_start_pfn;
6490}
6491
6492/*
6493 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6494 * then all holes in the requested range will be accounted for.
6495 */
6496unsigned long __init __absent_pages_in_range(int nid,
6497 unsigned long range_start_pfn,
6498 unsigned long range_end_pfn)
6499{
6500 unsigned long nr_absent = range_end_pfn - range_start_pfn;
6501 unsigned long start_pfn, end_pfn;
6502 int i;
6503
6504 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6505 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
6506 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
6507 nr_absent -= end_pfn - start_pfn;
6508 }
6509 return nr_absent;
6510}
6511
6512/**
6513 * absent_pages_in_range - Return number of page frames in holes within a range
6514 * @start_pfn: The start PFN to start searching for holes
6515 * @end_pfn: The end PFN to stop searching for holes
6516 *
6517 * Return: the number of pages frames in memory holes within a range.
6518 */
6519unsigned long __init absent_pages_in_range(unsigned long start_pfn,
6520 unsigned long end_pfn)
6521{
6522 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
6523}
6524
6525/* Return the number of page frames in holes in a zone on a node */
6526static unsigned long __init zone_absent_pages_in_node(int nid,
6527 unsigned long zone_type,
6528 unsigned long node_start_pfn,
6529 unsigned long node_end_pfn)
6530{
6531 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6532 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6533 unsigned long zone_start_pfn, zone_end_pfn;
6534 unsigned long nr_absent;
6535
6536 /* When hotadd a new node from cpu_up(), the node should be empty */
6537 if (!node_start_pfn && !node_end_pfn)
6538 return 0;
6539
6540 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6541 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6542
6543 adjust_zone_range_for_zone_movable(nid, zone_type,
6544 node_start_pfn, node_end_pfn,
6545 &zone_start_pfn, &zone_end_pfn);
6546 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
6547
6548 /*
6549 * ZONE_MOVABLE handling.
6550 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6551 * and vice versa.
6552 */
6553 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
6554 unsigned long start_pfn, end_pfn;
6555 struct memblock_region *r;
6556
6557 for_each_memblock(memory, r) {
6558 start_pfn = clamp(memblock_region_memory_base_pfn(r),
6559 zone_start_pfn, zone_end_pfn);
6560 end_pfn = clamp(memblock_region_memory_end_pfn(r),
6561 zone_start_pfn, zone_end_pfn);
6562
6563 if (zone_type == ZONE_MOVABLE &&
6564 memblock_is_mirror(r))
6565 nr_absent += end_pfn - start_pfn;
6566
6567 if (zone_type == ZONE_NORMAL &&
6568 !memblock_is_mirror(r))
6569 nr_absent += end_pfn - start_pfn;
6570 }
6571 }
6572
6573 return nr_absent;
6574}
6575
6576static void __init calculate_node_totalpages(struct pglist_data *pgdat,
6577 unsigned long node_start_pfn,
6578 unsigned long node_end_pfn)
6579{
6580 unsigned long realtotalpages = 0, totalpages = 0;
6581 enum zone_type i;
6582
6583 for (i = 0; i < MAX_NR_ZONES; i++) {
6584 struct zone *zone = pgdat->node_zones + i;
6585 unsigned long zone_start_pfn, zone_end_pfn;
6586 unsigned long spanned, absent;
6587 unsigned long size, real_size;
6588
6589 spanned = zone_spanned_pages_in_node(pgdat->node_id, i,
6590 node_start_pfn,
6591 node_end_pfn,
6592 &zone_start_pfn,
6593 &zone_end_pfn);
6594 absent = zone_absent_pages_in_node(pgdat->node_id, i,
6595 node_start_pfn,
6596 node_end_pfn);
6597
6598 size = spanned;
6599 real_size = size - absent;
6600
6601 if (size)
6602 zone->zone_start_pfn = zone_start_pfn;
6603 else
6604 zone->zone_start_pfn = 0;
6605 zone->spanned_pages = size;
6606 zone->present_pages = real_size;
6607
6608 totalpages += size;
6609 realtotalpages += real_size;
6610 }
6611
6612 pgdat->node_spanned_pages = totalpages;
6613 pgdat->node_present_pages = realtotalpages;
6614 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
6615 realtotalpages);
6616}
6617
6618#ifndef CONFIG_SPARSEMEM
6619/*
6620 * Calculate the size of the zone->blockflags rounded to an unsigned long
6621 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6622 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6623 * round what is now in bits to nearest long in bits, then return it in
6624 * bytes.
6625 */
6626static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
6627{
6628 unsigned long usemapsize;
6629
6630 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
6631 usemapsize = roundup(zonesize, pageblock_nr_pages);
6632 usemapsize = usemapsize >> pageblock_order;
6633 usemapsize *= NR_PAGEBLOCK_BITS;
6634 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
6635
6636 return usemapsize / 8;
6637}
6638
6639static void __ref setup_usemap(struct pglist_data *pgdat,
6640 struct zone *zone,
6641 unsigned long zone_start_pfn,
6642 unsigned long zonesize)
6643{
6644 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
6645 zone->pageblock_flags = NULL;
6646 if (usemapsize) {
6647 zone->pageblock_flags =
6648 memblock_alloc_node(usemapsize, SMP_CACHE_BYTES,
6649 pgdat->node_id);
6650 if (!zone->pageblock_flags)
6651 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6652 usemapsize, zone->name, pgdat->node_id);
6653 }
6654}
6655#else
6656static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
6657 unsigned long zone_start_pfn, unsigned long zonesize) {}
6658#endif /* CONFIG_SPARSEMEM */
6659
6660#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6661
6662/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6663void __init set_pageblock_order(void)
6664{
6665 unsigned int order;
6666
6667 /* Check that pageblock_nr_pages has not already been setup */
6668 if (pageblock_order)
6669 return;
6670
6671 if (HPAGE_SHIFT > PAGE_SHIFT)
6672 order = HUGETLB_PAGE_ORDER;
6673 else
6674 order = MAX_ORDER - 1;
6675
6676 /*
6677 * Assume the largest contiguous order of interest is a huge page.
6678 * This value may be variable depending on boot parameters on IA64 and
6679 * powerpc.
6680 */
6681 pageblock_order = order;
6682}
6683#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6684
6685/*
6686 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6687 * is unused as pageblock_order is set at compile-time. See
6688 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6689 * the kernel config
6690 */
6691void __init set_pageblock_order(void)
6692{
6693}
6694
6695#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6696
6697static unsigned long __init calc_memmap_size(unsigned long spanned_pages,
6698 unsigned long present_pages)
6699{
6700 unsigned long pages = spanned_pages;
6701
6702 /*
6703 * Provide a more accurate estimation if there are holes within
6704 * the zone and SPARSEMEM is in use. If there are holes within the
6705 * zone, each populated memory region may cost us one or two extra
6706 * memmap pages due to alignment because memmap pages for each
6707 * populated regions may not be naturally aligned on page boundary.
6708 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6709 */
6710 if (spanned_pages > present_pages + (present_pages >> 4) &&
6711 IS_ENABLED(CONFIG_SPARSEMEM))
6712 pages = present_pages;
6713
6714 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
6715}
6716
6717#ifdef CONFIG_TRANSPARENT_HUGEPAGE
6718static void pgdat_init_split_queue(struct pglist_data *pgdat)
6719{
6720 struct deferred_split *ds_queue = &pgdat->deferred_split_queue;
6721
6722 spin_lock_init(&ds_queue->split_queue_lock);
6723 INIT_LIST_HEAD(&ds_queue->split_queue);
6724 ds_queue->split_queue_len = 0;
6725}
6726#else
6727static void pgdat_init_split_queue(struct pglist_data *pgdat) {}
6728#endif
6729
6730#ifdef CONFIG_COMPACTION
6731static void pgdat_init_kcompactd(struct pglist_data *pgdat)
6732{
6733 init_waitqueue_head(&pgdat->kcompactd_wait);
6734}
6735#else
6736static void pgdat_init_kcompactd(struct pglist_data *pgdat) {}
6737#endif
6738
6739static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
6740{
6741 pgdat_resize_init(pgdat);
6742
6743 pgdat_init_split_queue(pgdat);
6744 pgdat_init_kcompactd(pgdat);
6745
6746 init_waitqueue_head(&pgdat->kswapd_wait);
6747 init_waitqueue_head(&pgdat->pfmemalloc_wait);
6748
6749 pgdat_page_ext_init(pgdat);
6750 spin_lock_init(&pgdat->lru_lock);
6751 lruvec_init(&pgdat->__lruvec);
6752}
6753
6754static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,
6755 unsigned long remaining_pages)
6756{
6757 atomic_long_set(&zone->managed_pages, remaining_pages);
6758 zone_set_nid(zone, nid);
6759 zone->name = zone_names[idx];
6760 zone->zone_pgdat = NODE_DATA(nid);
6761 spin_lock_init(&zone->lock);
6762 zone_seqlock_init(zone);
6763 zone_pcp_init(zone);
6764}
6765
6766/*
6767 * Set up the zone data structures
6768 * - init pgdat internals
6769 * - init all zones belonging to this node
6770 *
6771 * NOTE: this function is only called during memory hotplug
6772 */
6773#ifdef CONFIG_MEMORY_HOTPLUG
6774void __ref free_area_init_core_hotplug(int nid)
6775{
6776 enum zone_type z;
6777 pg_data_t *pgdat = NODE_DATA(nid);
6778
6779 pgdat_init_internals(pgdat);
6780 for (z = 0; z < MAX_NR_ZONES; z++)
6781 zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
6782}
6783#endif
6784
6785/*
6786 * Set up the zone data structures:
6787 * - mark all pages reserved
6788 * - mark all memory queues empty
6789 * - clear the memory bitmaps
6790 *
6791 * NOTE: pgdat should get zeroed by caller.
6792 * NOTE: this function is only called during early init.
6793 */
6794static void __init free_area_init_core(struct pglist_data *pgdat)
6795{
6796 enum zone_type j;
6797 int nid = pgdat->node_id;
6798
6799 pgdat_init_internals(pgdat);
6800 pgdat->per_cpu_nodestats = &boot_nodestats;
6801
6802 for (j = 0; j < MAX_NR_ZONES; j++) {
6803 struct zone *zone = pgdat->node_zones + j;
6804 unsigned long size, freesize, memmap_pages;
6805 unsigned long zone_start_pfn = zone->zone_start_pfn;
6806
6807 size = zone->spanned_pages;
6808 freesize = zone->present_pages;
6809
6810 /*
6811 * Adjust freesize so that it accounts for how much memory
6812 * is used by this zone for memmap. This affects the watermark
6813 * and per-cpu initialisations
6814 */
6815 memmap_pages = calc_memmap_size(size, freesize);
6816 if (!is_highmem_idx(j)) {
6817 if (freesize >= memmap_pages) {
6818 freesize -= memmap_pages;
6819 if (memmap_pages)
6820 printk(KERN_DEBUG
6821 " %s zone: %lu pages used for memmap\n",
6822 zone_names[j], memmap_pages);
6823 } else
6824 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6825 zone_names[j], memmap_pages, freesize);
6826 }
6827
6828 /* Account for reserved pages */
6829 if (j == 0 && freesize > dma_reserve) {
6830 freesize -= dma_reserve;
6831 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
6832 zone_names[0], dma_reserve);
6833 }
6834
6835 if (!is_highmem_idx(j))
6836 nr_kernel_pages += freesize;
6837 /* Charge for highmem memmap if there are enough kernel pages */
6838 else if (nr_kernel_pages > memmap_pages * 2)
6839 nr_kernel_pages -= memmap_pages;
6840 nr_all_pages += freesize;
6841
6842 /*
6843 * Set an approximate value for lowmem here, it will be adjusted
6844 * when the bootmem allocator frees pages into the buddy system.
6845 * And all highmem pages will be managed by the buddy system.
6846 */
6847 zone_init_internals(zone, j, nid, freesize);
6848
6849 if (!size)
6850 continue;
6851
6852 set_pageblock_order();
6853 setup_usemap(pgdat, zone, zone_start_pfn, size);
6854 init_currently_empty_zone(zone, zone_start_pfn, size);
6855 memmap_init(size, nid, j, zone_start_pfn);
6856 }
6857}
6858
6859#ifdef CONFIG_FLAT_NODE_MEM_MAP
6860static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
6861{
6862 unsigned long __maybe_unused start = 0;
6863 unsigned long __maybe_unused offset = 0;
6864
6865 /* Skip empty nodes */
6866 if (!pgdat->node_spanned_pages)
6867 return;
6868
6869 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6870 offset = pgdat->node_start_pfn - start;
6871 /* ia64 gets its own node_mem_map, before this, without bootmem */
6872 if (!pgdat->node_mem_map) {
6873 unsigned long size, end;
6874 struct page *map;
6875
6876 /*
6877 * The zone's endpoints aren't required to be MAX_ORDER
6878 * aligned but the node_mem_map endpoints must be in order
6879 * for the buddy allocator to function correctly.
6880 */
6881 end = pgdat_end_pfn(pgdat);
6882 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6883 size = (end - start) * sizeof(struct page);
6884 map = memblock_alloc_node(size, SMP_CACHE_BYTES,
6885 pgdat->node_id);
6886 if (!map)
6887 panic("Failed to allocate %ld bytes for node %d memory map\n",
6888 size, pgdat->node_id);
6889 pgdat->node_mem_map = map + offset;
6890 }
6891 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6892 __func__, pgdat->node_id, (unsigned long)pgdat,
6893 (unsigned long)pgdat->node_mem_map);
6894#ifndef CONFIG_NEED_MULTIPLE_NODES
6895 /*
6896 * With no DISCONTIG, the global mem_map is just set as node 0's
6897 */
6898 if (pgdat == NODE_DATA(0)) {
6899 mem_map = NODE_DATA(0)->node_mem_map;
6900 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6901 mem_map -= offset;
6902 }
6903#endif
6904}
6905#else
6906static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
6907#endif /* CONFIG_FLAT_NODE_MEM_MAP */
6908
6909#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6910static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
6911{
6912 pgdat->first_deferred_pfn = ULONG_MAX;
6913}
6914#else
6915static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
6916#endif
6917
6918static void __init free_area_init_node(int nid)
6919{
6920 pg_data_t *pgdat = NODE_DATA(nid);
6921 unsigned long start_pfn = 0;
6922 unsigned long end_pfn = 0;
6923
6924 /* pg_data_t should be reset to zero when it's allocated */
6925 WARN_ON(pgdat->nr_zones || pgdat->kswapd_highest_zoneidx);
6926
6927 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6928
6929 pgdat->node_id = nid;
6930 pgdat->node_start_pfn = start_pfn;
6931 pgdat->per_cpu_nodestats = NULL;
6932
6933 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6934 (u64)start_pfn << PAGE_SHIFT,
6935 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6936 calculate_node_totalpages(pgdat, start_pfn, end_pfn);
6937
6938 alloc_node_mem_map(pgdat);
6939 pgdat_set_deferred_range(pgdat);
6940
6941 free_area_init_core(pgdat);
6942}
6943
6944void __init free_area_init_memoryless_node(int nid)
6945{
6946 free_area_init_node(nid);
6947}
6948
6949#if !defined(CONFIG_FLAT_NODE_MEM_MAP)
6950/*
6951 * Initialize all valid struct pages in the range [spfn, epfn) and mark them
6952 * PageReserved(). Return the number of struct pages that were initialized.
6953 */
6954static u64 __init init_unavailable_range(unsigned long spfn, unsigned long epfn)
6955{
6956 unsigned long pfn;
6957 u64 pgcnt = 0;
6958
6959 for (pfn = spfn; pfn < epfn; pfn++) {
6960 if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
6961 pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
6962 + pageblock_nr_pages - 1;
6963 continue;
6964 }
6965 /*
6966 * Use a fake node/zone (0) for now. Some of these pages
6967 * (in memblock.reserved but not in memblock.memory) will
6968 * get re-initialized via reserve_bootmem_region() later.
6969 */
6970 __init_single_page(pfn_to_page(pfn), pfn, 0, 0);
6971 __SetPageReserved(pfn_to_page(pfn));
6972 pgcnt++;
6973 }
6974
6975 return pgcnt;
6976}
6977
6978/*
6979 * Only struct pages that are backed by physical memory are zeroed and
6980 * initialized by going through __init_single_page(). But, there are some
6981 * struct pages which are reserved in memblock allocator and their fields
6982 * may be accessed (for example page_to_pfn() on some configuration accesses
6983 * flags). We must explicitly initialize those struct pages.
6984 *
6985 * This function also addresses a similar issue where struct pages are left
6986 * uninitialized because the physical address range is not covered by
6987 * memblock.memory or memblock.reserved. That could happen when memblock
6988 * layout is manually configured via memmap=, or when the highest physical
6989 * address (max_pfn) does not end on a section boundary.
6990 */
6991static void __init init_unavailable_mem(void)
6992{
6993 phys_addr_t start, end;
6994 u64 i, pgcnt;
6995 phys_addr_t next = 0;
6996
6997 /*
6998 * Loop through unavailable ranges not covered by memblock.memory.
6999 */
7000 pgcnt = 0;
7001 for_each_mem_range(i, &memblock.memory, NULL,
7002 NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) {
7003 if (next < start)
7004 pgcnt += init_unavailable_range(PFN_DOWN(next),
7005 PFN_UP(start));
7006 next = end;
7007 }
7008
7009 /*
7010 * Early sections always have a fully populated memmap for the whole
7011 * section - see pfn_valid(). If the last section has holes at the
7012 * end and that section is marked "online", the memmap will be
7013 * considered initialized. Make sure that memmap has a well defined
7014 * state.
7015 */
7016 pgcnt += init_unavailable_range(PFN_DOWN(next),
7017 round_up(max_pfn, PAGES_PER_SECTION));
7018
7019 /*
7020 * Struct pages that do not have backing memory. This could be because
7021 * firmware is using some of this memory, or for some other reasons.
7022 */
7023 if (pgcnt)
7024 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt);
7025}
7026#else
7027static inline void __init init_unavailable_mem(void)
7028{
7029}
7030#endif /* !CONFIG_FLAT_NODE_MEM_MAP */
7031
7032#if MAX_NUMNODES > 1
7033/*
7034 * Figure out the number of possible node ids.
7035 */
7036void __init setup_nr_node_ids(void)
7037{
7038 unsigned int highest;
7039
7040 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
7041 nr_node_ids = highest + 1;
7042}
7043#endif
7044
7045/**
7046 * node_map_pfn_alignment - determine the maximum internode alignment
7047 *
7048 * This function should be called after node map is populated and sorted.
7049 * It calculates the maximum power of two alignment which can distinguish
7050 * all the nodes.
7051 *
7052 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7053 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7054 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7055 * shifted, 1GiB is enough and this function will indicate so.
7056 *
7057 * This is used to test whether pfn -> nid mapping of the chosen memory
7058 * model has fine enough granularity to avoid incorrect mapping for the
7059 * populated node map.
7060 *
7061 * Return: the determined alignment in pfn's. 0 if there is no alignment
7062 * requirement (single node).
7063 */
7064unsigned long __init node_map_pfn_alignment(void)
7065{
7066 unsigned long accl_mask = 0, last_end = 0;
7067 unsigned long start, end, mask;
7068 int last_nid = NUMA_NO_NODE;
7069 int i, nid;
7070
7071 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
7072 if (!start || last_nid < 0 || last_nid == nid) {
7073 last_nid = nid;
7074 last_end = end;
7075 continue;
7076 }
7077
7078 /*
7079 * Start with a mask granular enough to pin-point to the
7080 * start pfn and tick off bits one-by-one until it becomes
7081 * too coarse to separate the current node from the last.
7082 */
7083 mask = ~((1 << __ffs(start)) - 1);
7084 while (mask && last_end <= (start & (mask << 1)))
7085 mask <<= 1;
7086
7087 /* accumulate all internode masks */
7088 accl_mask |= mask;
7089 }
7090
7091 /* convert mask to number of pages */
7092 return ~accl_mask + 1;
7093}
7094
7095/**
7096 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7097 *
7098 * Return: the minimum PFN based on information provided via
7099 * memblock_set_node().
7100 */
7101unsigned long __init find_min_pfn_with_active_regions(void)
7102{
7103 return PHYS_PFN(memblock_start_of_DRAM());
7104}
7105
7106/*
7107 * early_calculate_totalpages()
7108 * Sum pages in active regions for movable zone.
7109 * Populate N_MEMORY for calculating usable_nodes.
7110 */
7111static unsigned long __init early_calculate_totalpages(void)
7112{
7113 unsigned long totalpages = 0;
7114 unsigned long start_pfn, end_pfn;
7115 int i, nid;
7116
7117 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7118 unsigned long pages = end_pfn - start_pfn;
7119
7120 totalpages += pages;
7121 if (pages)
7122 node_set_state(nid, N_MEMORY);
7123 }
7124 return totalpages;
7125}
7126
7127/*
7128 * Find the PFN the Movable zone begins in each node. Kernel memory
7129 * is spread evenly between nodes as long as the nodes have enough
7130 * memory. When they don't, some nodes will have more kernelcore than
7131 * others
7132 */
7133static void __init find_zone_movable_pfns_for_nodes(void)
7134{
7135 int i, nid;
7136 unsigned long usable_startpfn;
7137 unsigned long kernelcore_node, kernelcore_remaining;
7138 /* save the state before borrow the nodemask */
7139 nodemask_t saved_node_state = node_states[N_MEMORY];
7140 unsigned long totalpages = early_calculate_totalpages();
7141 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
7142 struct memblock_region *r;
7143
7144 /* Need to find movable_zone earlier when movable_node is specified. */
7145 find_usable_zone_for_movable();
7146
7147 /*
7148 * If movable_node is specified, ignore kernelcore and movablecore
7149 * options.
7150 */
7151 if (movable_node_is_enabled()) {
7152 for_each_memblock(memory, r) {
7153 if (!memblock_is_hotpluggable(r))
7154 continue;
7155
7156 nid = memblock_get_region_node(r);
7157
7158 usable_startpfn = PFN_DOWN(r->base);
7159 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7160 min(usable_startpfn, zone_movable_pfn[nid]) :
7161 usable_startpfn;
7162 }
7163
7164 goto out2;
7165 }
7166
7167 /*
7168 * If kernelcore=mirror is specified, ignore movablecore option
7169 */
7170 if (mirrored_kernelcore) {
7171 bool mem_below_4gb_not_mirrored = false;
7172
7173 for_each_memblock(memory, r) {
7174 if (memblock_is_mirror(r))
7175 continue;
7176
7177 nid = memblock_get_region_node(r);
7178
7179 usable_startpfn = memblock_region_memory_base_pfn(r);
7180
7181 if (usable_startpfn < 0x100000) {
7182 mem_below_4gb_not_mirrored = true;
7183 continue;
7184 }
7185
7186 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7187 min(usable_startpfn, zone_movable_pfn[nid]) :
7188 usable_startpfn;
7189 }
7190
7191 if (mem_below_4gb_not_mirrored)
7192 pr_warn("This configuration results in unmirrored kernel memory.\n");
7193
7194 goto out2;
7195 }
7196
7197 /*
7198 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7199 * amount of necessary memory.
7200 */
7201 if (required_kernelcore_percent)
7202 required_kernelcore = (totalpages * 100 * required_kernelcore_percent) /
7203 10000UL;
7204 if (required_movablecore_percent)
7205 required_movablecore = (totalpages * 100 * required_movablecore_percent) /
7206 10000UL;
7207
7208 /*
7209 * If movablecore= was specified, calculate what size of
7210 * kernelcore that corresponds so that memory usable for
7211 * any allocation type is evenly spread. If both kernelcore
7212 * and movablecore are specified, then the value of kernelcore
7213 * will be used for required_kernelcore if it's greater than
7214 * what movablecore would have allowed.
7215 */
7216 if (required_movablecore) {
7217 unsigned long corepages;
7218
7219 /*
7220 * Round-up so that ZONE_MOVABLE is at least as large as what
7221 * was requested by the user
7222 */
7223 required_movablecore =
7224 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
7225 required_movablecore = min(totalpages, required_movablecore);
7226 corepages = totalpages - required_movablecore;
7227
7228 required_kernelcore = max(required_kernelcore, corepages);
7229 }
7230
7231 /*
7232 * If kernelcore was not specified or kernelcore size is larger
7233 * than totalpages, there is no ZONE_MOVABLE.
7234 */
7235 if (!required_kernelcore || required_kernelcore >= totalpages)
7236 goto out;
7237
7238 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7239 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
7240
7241restart:
7242 /* Spread kernelcore memory as evenly as possible throughout nodes */
7243 kernelcore_node = required_kernelcore / usable_nodes;
7244 for_each_node_state(nid, N_MEMORY) {
7245 unsigned long start_pfn, end_pfn;
7246
7247 /*
7248 * Recalculate kernelcore_node if the division per node
7249 * now exceeds what is necessary to satisfy the requested
7250 * amount of memory for the kernel
7251 */
7252 if (required_kernelcore < kernelcore_node)
7253 kernelcore_node = required_kernelcore / usable_nodes;
7254
7255 /*
7256 * As the map is walked, we track how much memory is usable
7257 * by the kernel using kernelcore_remaining. When it is
7258 * 0, the rest of the node is usable by ZONE_MOVABLE
7259 */
7260 kernelcore_remaining = kernelcore_node;
7261
7262 /* Go through each range of PFNs within this node */
7263 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
7264 unsigned long size_pages;
7265
7266 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
7267 if (start_pfn >= end_pfn)
7268 continue;
7269
7270 /* Account for what is only usable for kernelcore */
7271 if (start_pfn < usable_startpfn) {
7272 unsigned long kernel_pages;
7273 kernel_pages = min(end_pfn, usable_startpfn)
7274 - start_pfn;
7275
7276 kernelcore_remaining -= min(kernel_pages,
7277 kernelcore_remaining);
7278 required_kernelcore -= min(kernel_pages,
7279 required_kernelcore);
7280
7281 /* Continue if range is now fully accounted */
7282 if (end_pfn <= usable_startpfn) {
7283
7284 /*
7285 * Push zone_movable_pfn to the end so
7286 * that if we have to rebalance
7287 * kernelcore across nodes, we will
7288 * not double account here
7289 */
7290 zone_movable_pfn[nid] = end_pfn;
7291 continue;
7292 }
7293 start_pfn = usable_startpfn;
7294 }
7295
7296 /*
7297 * The usable PFN range for ZONE_MOVABLE is from
7298 * start_pfn->end_pfn. Calculate size_pages as the
7299 * number of pages used as kernelcore
7300 */
7301 size_pages = end_pfn - start_pfn;
7302 if (size_pages > kernelcore_remaining)
7303 size_pages = kernelcore_remaining;
7304 zone_movable_pfn[nid] = start_pfn + size_pages;
7305
7306 /*
7307 * Some kernelcore has been met, update counts and
7308 * break if the kernelcore for this node has been
7309 * satisfied
7310 */
7311 required_kernelcore -= min(required_kernelcore,
7312 size_pages);
7313 kernelcore_remaining -= size_pages;
7314 if (!kernelcore_remaining)
7315 break;
7316 }
7317 }
7318
7319 /*
7320 * If there is still required_kernelcore, we do another pass with one
7321 * less node in the count. This will push zone_movable_pfn[nid] further
7322 * along on the nodes that still have memory until kernelcore is
7323 * satisfied
7324 */
7325 usable_nodes--;
7326 if (usable_nodes && required_kernelcore > usable_nodes)
7327 goto restart;
7328
7329out2:
7330 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7331 for (nid = 0; nid < MAX_NUMNODES; nid++)
7332 zone_movable_pfn[nid] =
7333 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
7334
7335out:
7336 /* restore the node_state */
7337 node_states[N_MEMORY] = saved_node_state;
7338}
7339
7340/* Any regular or high memory on that node ? */
7341static void check_for_memory(pg_data_t *pgdat, int nid)
7342{
7343 enum zone_type zone_type;
7344
7345 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
7346 struct zone *zone = &pgdat->node_zones[zone_type];
7347 if (populated_zone(zone)) {
7348 if (IS_ENABLED(CONFIG_HIGHMEM))
7349 node_set_state(nid, N_HIGH_MEMORY);
7350 if (zone_type <= ZONE_NORMAL)
7351 node_set_state(nid, N_NORMAL_MEMORY);
7352 break;
7353 }
7354 }
7355}
7356
7357/*
7358 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7359 * such cases we allow max_zone_pfn sorted in the descending order
7360 */
7361bool __weak arch_has_descending_max_zone_pfns(void)
7362{
7363 return false;
7364}
7365
7366/**
7367 * free_area_init - Initialise all pg_data_t and zone data
7368 * @max_zone_pfn: an array of max PFNs for each zone
7369 *
7370 * This will call free_area_init_node() for each active node in the system.
7371 * Using the page ranges provided by memblock_set_node(), the size of each
7372 * zone in each node and their holes is calculated. If the maximum PFN
7373 * between two adjacent zones match, it is assumed that the zone is empty.
7374 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7375 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7376 * starts where the previous one ended. For example, ZONE_DMA32 starts
7377 * at arch_max_dma_pfn.
7378 */
7379void __init free_area_init(unsigned long *max_zone_pfn)
7380{
7381 unsigned long start_pfn, end_pfn;
7382 int i, nid, zone;
7383 bool descending;
7384
7385 /* Record where the zone boundaries are */
7386 memset(arch_zone_lowest_possible_pfn, 0,
7387 sizeof(arch_zone_lowest_possible_pfn));
7388 memset(arch_zone_highest_possible_pfn, 0,
7389 sizeof(arch_zone_highest_possible_pfn));
7390
7391 start_pfn = find_min_pfn_with_active_regions();
7392 descending = arch_has_descending_max_zone_pfns();
7393
7394 for (i = 0; i < MAX_NR_ZONES; i++) {
7395 if (descending)
7396 zone = MAX_NR_ZONES - i - 1;
7397 else
7398 zone = i;
7399
7400 if (zone == ZONE_MOVABLE)
7401 continue;
7402
7403 end_pfn = max(max_zone_pfn[zone], start_pfn);
7404 arch_zone_lowest_possible_pfn[zone] = start_pfn;
7405 arch_zone_highest_possible_pfn[zone] = end_pfn;
7406
7407 start_pfn = end_pfn;
7408 }
7409
7410 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7411 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
7412 find_zone_movable_pfns_for_nodes();
7413
7414 /* Print out the zone ranges */
7415 pr_info("Zone ranges:\n");
7416 for (i = 0; i < MAX_NR_ZONES; i++) {
7417 if (i == ZONE_MOVABLE)
7418 continue;
7419 pr_info(" %-8s ", zone_names[i]);
7420 if (arch_zone_lowest_possible_pfn[i] ==
7421 arch_zone_highest_possible_pfn[i])
7422 pr_cont("empty\n");
7423 else
7424 pr_cont("[mem %#018Lx-%#018Lx]\n",
7425 (u64)arch_zone_lowest_possible_pfn[i]
7426 << PAGE_SHIFT,
7427 ((u64)arch_zone_highest_possible_pfn[i]
7428 << PAGE_SHIFT) - 1);
7429 }
7430
7431 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7432 pr_info("Movable zone start for each node\n");
7433 for (i = 0; i < MAX_NUMNODES; i++) {
7434 if (zone_movable_pfn[i])
7435 pr_info(" Node %d: %#018Lx\n", i,
7436 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
7437 }
7438
7439 /*
7440 * Print out the early node map, and initialize the
7441 * subsection-map relative to active online memory ranges to
7442 * enable future "sub-section" extensions of the memory map.
7443 */
7444 pr_info("Early memory node ranges\n");
7445 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7446 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
7447 (u64)start_pfn << PAGE_SHIFT,
7448 ((u64)end_pfn << PAGE_SHIFT) - 1);
7449 subsection_map_init(start_pfn, end_pfn - start_pfn);
7450 }
7451
7452 /* Initialise every node */
7453 mminit_verify_pageflags_layout();
7454 setup_nr_node_ids();
7455 init_unavailable_mem();
7456 for_each_online_node(nid) {
7457 pg_data_t *pgdat = NODE_DATA(nid);
7458 free_area_init_node(nid);
7459
7460 /* Any memory on that node */
7461 if (pgdat->node_present_pages)
7462 node_set_state(nid, N_MEMORY);
7463 check_for_memory(pgdat, nid);
7464 }
7465}
7466
7467static int __init cmdline_parse_core(char *p, unsigned long *core,
7468 unsigned long *percent)
7469{
7470 unsigned long long coremem;
7471 char *endptr;
7472
7473 if (!p)
7474 return -EINVAL;
7475
7476 /* Value may be a percentage of total memory, otherwise bytes */
7477 coremem = simple_strtoull(p, &endptr, 0);
7478 if (*endptr == '%') {
7479 /* Paranoid check for percent values greater than 100 */
7480 WARN_ON(coremem > 100);
7481
7482 *percent = coremem;
7483 } else {
7484 coremem = memparse(p, &p);
7485 /* Paranoid check that UL is enough for the coremem value */
7486 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
7487
7488 *core = coremem >> PAGE_SHIFT;
7489 *percent = 0UL;
7490 }
7491 return 0;
7492}
7493
7494/*
7495 * kernelcore=size sets the amount of memory for use for allocations that
7496 * cannot be reclaimed or migrated.
7497 */
7498static int __init cmdline_parse_kernelcore(char *p)
7499{
7500 /* parse kernelcore=mirror */
7501 if (parse_option_str(p, "mirror")) {
7502 mirrored_kernelcore = true;
7503 return 0;
7504 }
7505
7506 return cmdline_parse_core(p, &required_kernelcore,
7507 &required_kernelcore_percent);
7508}
7509
7510/*
7511 * movablecore=size sets the amount of memory for use for allocations that
7512 * can be reclaimed or migrated.
7513 */
7514static int __init cmdline_parse_movablecore(char *p)
7515{
7516 return cmdline_parse_core(p, &required_movablecore,
7517 &required_movablecore_percent);
7518}
7519
7520early_param("kernelcore", cmdline_parse_kernelcore);
7521early_param("movablecore", cmdline_parse_movablecore);
7522
7523void adjust_managed_page_count(struct page *page, long count)
7524{
7525 atomic_long_add(count, &page_zone(page)->managed_pages);
7526 totalram_pages_add(count);
7527#ifdef CONFIG_HIGHMEM
7528 if (PageHighMem(page))
7529 totalhigh_pages_add(count);
7530#endif
7531}
7532EXPORT_SYMBOL(adjust_managed_page_count);
7533
7534unsigned long free_reserved_area(void *start, void *end, int poison, const char *s)
7535{
7536 void *pos;
7537 unsigned long pages = 0;
7538
7539 start = (void *)PAGE_ALIGN((unsigned long)start);
7540 end = (void *)((unsigned long)end & PAGE_MASK);
7541 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
7542 struct page *page = virt_to_page(pos);
7543 void *direct_map_addr;
7544
7545 /*
7546 * 'direct_map_addr' might be different from 'pos'
7547 * because some architectures' virt_to_page()
7548 * work with aliases. Getting the direct map
7549 * address ensures that we get a _writeable_
7550 * alias for the memset().
7551 */
7552 direct_map_addr = page_address(page);
7553 if ((unsigned int)poison <= 0xFF)
7554 memset(direct_map_addr, poison, PAGE_SIZE);
7555
7556 free_reserved_page(page);
7557 }
7558
7559 if (pages && s)
7560 pr_info("Freeing %s memory: %ldK\n",
7561 s, pages << (PAGE_SHIFT - 10));
7562
7563 return pages;
7564}
7565
7566#ifdef CONFIG_HIGHMEM
7567void free_highmem_page(struct page *page)
7568{
7569 __free_reserved_page(page);
7570 totalram_pages_inc();
7571 atomic_long_inc(&page_zone(page)->managed_pages);
7572 totalhigh_pages_inc();
7573}
7574#endif
7575
7576
7577void __init mem_init_print_info(const char *str)
7578{
7579 unsigned long physpages, codesize, datasize, rosize, bss_size;
7580 unsigned long init_code_size, init_data_size;
7581
7582 physpages = get_num_physpages();
7583 codesize = _etext - _stext;
7584 datasize = _edata - _sdata;
7585 rosize = __end_rodata - __start_rodata;
7586 bss_size = __bss_stop - __bss_start;
7587 init_data_size = __init_end - __init_begin;
7588 init_code_size = _einittext - _sinittext;
7589
7590 /*
7591 * Detect special cases and adjust section sizes accordingly:
7592 * 1) .init.* may be embedded into .data sections
7593 * 2) .init.text.* may be out of [__init_begin, __init_end],
7594 * please refer to arch/tile/kernel/vmlinux.lds.S.
7595 * 3) .rodata.* may be embedded into .text or .data sections.
7596 */
7597#define adj_init_size(start, end, size, pos, adj) \
7598 do { \
7599 if (start <= pos && pos < end && size > adj) \
7600 size -= adj; \
7601 } while (0)
7602
7603 adj_init_size(__init_begin, __init_end, init_data_size,
7604 _sinittext, init_code_size);
7605 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
7606 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
7607 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
7608 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
7609
7610#undef adj_init_size
7611
7612 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7613#ifdef CONFIG_HIGHMEM
7614 ", %luK highmem"
7615#endif
7616 "%s%s)\n",
7617 nr_free_pages() << (PAGE_SHIFT - 10),
7618 physpages << (PAGE_SHIFT - 10),
7619 codesize >> 10, datasize >> 10, rosize >> 10,
7620 (init_data_size + init_code_size) >> 10, bss_size >> 10,
7621 (physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10),
7622 totalcma_pages << (PAGE_SHIFT - 10),
7623#ifdef CONFIG_HIGHMEM
7624 totalhigh_pages() << (PAGE_SHIFT - 10),
7625#endif
7626 str ? ", " : "", str ? str : "");
7627}
7628
7629/**
7630 * set_dma_reserve - set the specified number of pages reserved in the first zone
7631 * @new_dma_reserve: The number of pages to mark reserved
7632 *
7633 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7634 * In the DMA zone, a significant percentage may be consumed by kernel image
7635 * and other unfreeable allocations which can skew the watermarks badly. This
7636 * function may optionally be used to account for unfreeable pages in the
7637 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7638 * smaller per-cpu batchsize.
7639 */
7640void __init set_dma_reserve(unsigned long new_dma_reserve)
7641{
7642 dma_reserve = new_dma_reserve;
7643}
7644
7645static int page_alloc_cpu_dead(unsigned int cpu)
7646{
7647
7648 lru_add_drain_cpu(cpu);
7649 drain_pages(cpu);
7650
7651 /*
7652 * Spill the event counters of the dead processor
7653 * into the current processors event counters.
7654 * This artificially elevates the count of the current
7655 * processor.
7656 */
7657 vm_events_fold_cpu(cpu);
7658
7659 /*
7660 * Zero the differential counters of the dead processor
7661 * so that the vm statistics are consistent.
7662 *
7663 * This is only okay since the processor is dead and cannot
7664 * race with what we are doing.
7665 */
7666 cpu_vm_stats_fold(cpu);
7667 return 0;
7668}
7669
7670#ifdef CONFIG_NUMA
7671int hashdist = HASHDIST_DEFAULT;
7672
7673static int __init set_hashdist(char *str)
7674{
7675 if (!str)
7676 return 0;
7677 hashdist = simple_strtoul(str, &str, 0);
7678 return 1;
7679}
7680__setup("hashdist=", set_hashdist);
7681#endif
7682
7683void __init page_alloc_init(void)
7684{
7685 int ret;
7686
7687#ifdef CONFIG_NUMA
7688 if (num_node_state(N_MEMORY) == 1)
7689 hashdist = 0;
7690#endif
7691
7692 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD,
7693 "mm/page_alloc:dead", NULL,
7694 page_alloc_cpu_dead);
7695 WARN_ON(ret < 0);
7696}
7697
7698/*
7699 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7700 * or min_free_kbytes changes.
7701 */
7702static void calculate_totalreserve_pages(void)
7703{
7704 struct pglist_data *pgdat;
7705 unsigned long reserve_pages = 0;
7706 enum zone_type i, j;
7707
7708 for_each_online_pgdat(pgdat) {
7709
7710 pgdat->totalreserve_pages = 0;
7711
7712 for (i = 0; i < MAX_NR_ZONES; i++) {
7713 struct zone *zone = pgdat->node_zones + i;
7714 long max = 0;
7715 unsigned long managed_pages = zone_managed_pages(zone);
7716
7717 /* Find valid and maximum lowmem_reserve in the zone */
7718 for (j = i; j < MAX_NR_ZONES; j++) {
7719 if (zone->lowmem_reserve[j] > max)
7720 max = zone->lowmem_reserve[j];
7721 }
7722
7723 /* we treat the high watermark as reserved pages. */
7724 max += high_wmark_pages(zone);
7725
7726 if (max > managed_pages)
7727 max = managed_pages;
7728
7729 pgdat->totalreserve_pages += max;
7730
7731 reserve_pages += max;
7732 }
7733 }
7734 totalreserve_pages = reserve_pages;
7735}
7736
7737/*
7738 * setup_per_zone_lowmem_reserve - called whenever
7739 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7740 * has a correct pages reserved value, so an adequate number of
7741 * pages are left in the zone after a successful __alloc_pages().
7742 */
7743static void setup_per_zone_lowmem_reserve(void)
7744{
7745 struct pglist_data *pgdat;
7746 enum zone_type j, idx;
7747
7748 for_each_online_pgdat(pgdat) {
7749 for (j = 0; j < MAX_NR_ZONES; j++) {
7750 struct zone *zone = pgdat->node_zones + j;
7751 unsigned long managed_pages = zone_managed_pages(zone);
7752
7753 zone->lowmem_reserve[j] = 0;
7754
7755 idx = j;
7756 while (idx) {
7757 struct zone *lower_zone;
7758
7759 idx--;
7760 lower_zone = pgdat->node_zones + idx;
7761
7762 if (!sysctl_lowmem_reserve_ratio[idx] ||
7763 !zone_managed_pages(lower_zone)) {
7764 lower_zone->lowmem_reserve[j] = 0;
7765 continue;
7766 } else {
7767 lower_zone->lowmem_reserve[j] =
7768 managed_pages / sysctl_lowmem_reserve_ratio[idx];
7769 }
7770 managed_pages += zone_managed_pages(lower_zone);
7771 }
7772 }
7773 }
7774
7775 /* update totalreserve_pages */
7776 calculate_totalreserve_pages();
7777}
7778
7779static void __setup_per_zone_wmarks(void)
7780{
7781 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
7782 unsigned long lowmem_pages = 0;
7783 struct zone *zone;
7784 unsigned long flags;
7785
7786 /* Calculate total number of !ZONE_HIGHMEM pages */
7787 for_each_zone(zone) {
7788 if (!is_highmem(zone))
7789 lowmem_pages += zone_managed_pages(zone);
7790 }
7791
7792 for_each_zone(zone) {
7793 u64 tmp;
7794
7795 spin_lock_irqsave(&zone->lock, flags);
7796 tmp = (u64)pages_min * zone_managed_pages(zone);
7797 do_div(tmp, lowmem_pages);
7798 if (is_highmem(zone)) {
7799 /*
7800 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7801 * need highmem pages, so cap pages_min to a small
7802 * value here.
7803 *
7804 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7805 * deltas control async page reclaim, and so should
7806 * not be capped for highmem.
7807 */
7808 unsigned long min_pages;
7809
7810 min_pages = zone_managed_pages(zone) / 1024;
7811 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
7812 zone->_watermark[WMARK_MIN] = min_pages;
7813 } else {
7814 /*
7815 * If it's a lowmem zone, reserve a number of pages
7816 * proportionate to the zone's size.
7817 */
7818 zone->_watermark[WMARK_MIN] = tmp;
7819 }
7820
7821 /*
7822 * Set the kswapd watermarks distance according to the
7823 * scale factor in proportion to available memory, but
7824 * ensure a minimum size on small systems.
7825 */
7826 tmp = max_t(u64, tmp >> 2,
7827 mult_frac(zone_managed_pages(zone),
7828 watermark_scale_factor, 10000));
7829
7830 zone->watermark_boost = 0;
7831 zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
7832 zone->_watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
7833
7834 spin_unlock_irqrestore(&zone->lock, flags);
7835 }
7836
7837 /* update totalreserve_pages */
7838 calculate_totalreserve_pages();
7839}
7840
7841/**
7842 * setup_per_zone_wmarks - called when min_free_kbytes changes
7843 * or when memory is hot-{added|removed}
7844 *
7845 * Ensures that the watermark[min,low,high] values for each zone are set
7846 * correctly with respect to min_free_kbytes.
7847 */
7848void setup_per_zone_wmarks(void)
7849{
7850 static DEFINE_SPINLOCK(lock);
7851
7852 spin_lock(&lock);
7853 __setup_per_zone_wmarks();
7854 spin_unlock(&lock);
7855}
7856
7857/*
7858 * Initialise min_free_kbytes.
7859 *
7860 * For small machines we want it small (128k min). For large machines
7861 * we want it large (256MB max). But it is not linear, because network
7862 * bandwidth does not increase linearly with machine size. We use
7863 *
7864 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7865 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7866 *
7867 * which yields
7868 *
7869 * 16MB: 512k
7870 * 32MB: 724k
7871 * 64MB: 1024k
7872 * 128MB: 1448k
7873 * 256MB: 2048k
7874 * 512MB: 2896k
7875 * 1024MB: 4096k
7876 * 2048MB: 5792k
7877 * 4096MB: 8192k
7878 * 8192MB: 11584k
7879 * 16384MB: 16384k
7880 */
7881int __meminit init_per_zone_wmark_min(void)
7882{
7883 unsigned long lowmem_kbytes;
7884 int new_min_free_kbytes;
7885
7886 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
7887 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
7888
7889 if (new_min_free_kbytes > user_min_free_kbytes) {
7890 min_free_kbytes = new_min_free_kbytes;
7891 if (min_free_kbytes < 128)
7892 min_free_kbytes = 128;
7893 if (min_free_kbytes > 262144)
7894 min_free_kbytes = 262144;
7895 } else {
7896 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7897 new_min_free_kbytes, user_min_free_kbytes);
7898 }
7899 setup_per_zone_wmarks();
7900 refresh_zone_stat_thresholds();
7901 setup_per_zone_lowmem_reserve();
7902
7903#ifdef CONFIG_NUMA
7904 setup_min_unmapped_ratio();
7905 setup_min_slab_ratio();
7906#endif
7907
7908 khugepaged_min_free_kbytes_update();
7909
7910 return 0;
7911}
7912postcore_initcall(init_per_zone_wmark_min)
7913
7914/*
7915 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7916 * that we can call two helper functions whenever min_free_kbytes
7917 * changes.
7918 */
7919int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
7920 void *buffer, size_t *length, loff_t *ppos)
7921{
7922 int rc;
7923
7924 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7925 if (rc)
7926 return rc;
7927
7928 if (write) {
7929 user_min_free_kbytes = min_free_kbytes;
7930 setup_per_zone_wmarks();
7931 }
7932 return 0;
7933}
7934
7935int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
7936 void *buffer, size_t *length, loff_t *ppos)
7937{
7938 int rc;
7939
7940 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7941 if (rc)
7942 return rc;
7943
7944 if (write)
7945 setup_per_zone_wmarks();
7946
7947 return 0;
7948}
7949
7950#ifdef CONFIG_NUMA
7951static void setup_min_unmapped_ratio(void)
7952{
7953 pg_data_t *pgdat;
7954 struct zone *zone;
7955
7956 for_each_online_pgdat(pgdat)
7957 pgdat->min_unmapped_pages = 0;
7958
7959 for_each_zone(zone)
7960 zone->zone_pgdat->min_unmapped_pages += (zone_managed_pages(zone) *
7961 sysctl_min_unmapped_ratio) / 100;
7962}
7963
7964
7965int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
7966 void *buffer, size_t *length, loff_t *ppos)
7967{
7968 int rc;
7969
7970 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7971 if (rc)
7972 return rc;
7973
7974 setup_min_unmapped_ratio();
7975
7976 return 0;
7977}
7978
7979static void setup_min_slab_ratio(void)
7980{
7981 pg_data_t *pgdat;
7982 struct zone *zone;
7983
7984 for_each_online_pgdat(pgdat)
7985 pgdat->min_slab_pages = 0;
7986
7987 for_each_zone(zone)
7988 zone->zone_pgdat->min_slab_pages += (zone_managed_pages(zone) *
7989 sysctl_min_slab_ratio) / 100;
7990}
7991
7992int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
7993 void *buffer, size_t *length, loff_t *ppos)
7994{
7995 int rc;
7996
7997 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7998 if (rc)
7999 return rc;
8000
8001 setup_min_slab_ratio();
8002
8003 return 0;
8004}
8005#endif
8006
8007/*
8008 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8009 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8010 * whenever sysctl_lowmem_reserve_ratio changes.
8011 *
8012 * The reserve ratio obviously has absolutely no relation with the
8013 * minimum watermarks. The lowmem reserve ratio can only make sense
8014 * if in function of the boot time zone sizes.
8015 */
8016int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
8017 void *buffer, size_t *length, loff_t *ppos)
8018{
8019 int i;
8020
8021 proc_dointvec_minmax(table, write, buffer, length, ppos);
8022
8023 for (i = 0; i < MAX_NR_ZONES; i++) {
8024 if (sysctl_lowmem_reserve_ratio[i] < 1)
8025 sysctl_lowmem_reserve_ratio[i] = 0;
8026 }
8027
8028 setup_per_zone_lowmem_reserve();
8029 return 0;
8030}
8031
8032static void __zone_pcp_update(struct zone *zone)
8033{
8034 unsigned int cpu;
8035
8036 for_each_possible_cpu(cpu)
8037 pageset_set_high_and_batch(zone,
8038 per_cpu_ptr(zone->pageset, cpu));
8039}
8040
8041/*
8042 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8043 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8044 * pagelist can have before it gets flushed back to buddy allocator.
8045 */
8046int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
8047 void *buffer, size_t *length, loff_t *ppos)
8048{
8049 struct zone *zone;
8050 int old_percpu_pagelist_fraction;
8051 int ret;
8052
8053 mutex_lock(&pcp_batch_high_lock);
8054 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
8055
8056 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
8057 if (!write || ret < 0)
8058 goto out;
8059
8060 /* Sanity checking to avoid pcp imbalance */
8061 if (percpu_pagelist_fraction &&
8062 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
8063 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
8064 ret = -EINVAL;
8065 goto out;
8066 }
8067
8068 /* No change? */
8069 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
8070 goto out;
8071
8072 for_each_populated_zone(zone)
8073 __zone_pcp_update(zone);
8074out:
8075 mutex_unlock(&pcp_batch_high_lock);
8076 return ret;
8077}
8078
8079#ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8080/*
8081 * Returns the number of pages that arch has reserved but
8082 * is not known to alloc_large_system_hash().
8083 */
8084static unsigned long __init arch_reserved_kernel_pages(void)
8085{
8086 return 0;
8087}
8088#endif
8089
8090/*
8091 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8092 * machines. As memory size is increased the scale is also increased but at
8093 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8094 * quadruples the scale is increased by one, which means the size of hash table
8095 * only doubles, instead of quadrupling as well.
8096 * Because 32-bit systems cannot have large physical memory, where this scaling
8097 * makes sense, it is disabled on such platforms.
8098 */
8099#if __BITS_PER_LONG > 32
8100#define ADAPT_SCALE_BASE (64ul << 30)
8101#define ADAPT_SCALE_SHIFT 2
8102#define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8103#endif
8104
8105/*
8106 * allocate a large system hash table from bootmem
8107 * - it is assumed that the hash table must contain an exact power-of-2
8108 * quantity of entries
8109 * - limit is the number of hash buckets, not the total allocation size
8110 */
8111void *__init alloc_large_system_hash(const char *tablename,
8112 unsigned long bucketsize,
8113 unsigned long numentries,
8114 int scale,
8115 int flags,
8116 unsigned int *_hash_shift,
8117 unsigned int *_hash_mask,
8118 unsigned long low_limit,
8119 unsigned long high_limit)
8120{
8121 unsigned long long max = high_limit;
8122 unsigned long log2qty, size;
8123 void *table = NULL;
8124 gfp_t gfp_flags;
8125 bool virt;
8126
8127 /* allow the kernel cmdline to have a say */
8128 if (!numentries) {
8129 /* round applicable memory size up to nearest megabyte */
8130 numentries = nr_kernel_pages;
8131 numentries -= arch_reserved_kernel_pages();
8132
8133 /* It isn't necessary when PAGE_SIZE >= 1MB */
8134 if (PAGE_SHIFT < 20)
8135 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
8136
8137#if __BITS_PER_LONG > 32
8138 if (!high_limit) {
8139 unsigned long adapt;
8140
8141 for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries;
8142 adapt <<= ADAPT_SCALE_SHIFT)
8143 scale++;
8144 }
8145#endif
8146
8147 /* limit to 1 bucket per 2^scale bytes of low memory */
8148 if (scale > PAGE_SHIFT)
8149 numentries >>= (scale - PAGE_SHIFT);
8150 else
8151 numentries <<= (PAGE_SHIFT - scale);
8152
8153 /* Make sure we've got at least a 0-order allocation.. */
8154 if (unlikely(flags & HASH_SMALL)) {
8155 /* Makes no sense without HASH_EARLY */
8156 WARN_ON(!(flags & HASH_EARLY));
8157 if (!(numentries >> *_hash_shift)) {
8158 numentries = 1UL << *_hash_shift;
8159 BUG_ON(!numentries);
8160 }
8161 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
8162 numentries = PAGE_SIZE / bucketsize;
8163 }
8164 numentries = roundup_pow_of_two(numentries);
8165
8166 /* limit allocation size to 1/16 total memory by default */
8167 if (max == 0) {
8168 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
8169 do_div(max, bucketsize);
8170 }
8171 max = min(max, 0x80000000ULL);
8172
8173 if (numentries < low_limit)
8174 numentries = low_limit;
8175 if (numentries > max)
8176 numentries = max;
8177
8178 log2qty = ilog2(numentries);
8179
8180 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
8181 do {
8182 virt = false;
8183 size = bucketsize << log2qty;
8184 if (flags & HASH_EARLY) {
8185 if (flags & HASH_ZERO)
8186 table = memblock_alloc(size, SMP_CACHE_BYTES);
8187 else
8188 table = memblock_alloc_raw(size,
8189 SMP_CACHE_BYTES);
8190 } else if (get_order(size) >= MAX_ORDER || hashdist) {
8191 table = __vmalloc(size, gfp_flags);
8192 virt = true;
8193 } else {
8194 /*
8195 * If bucketsize is not a power-of-two, we may free
8196 * some pages at the end of hash table which
8197 * alloc_pages_exact() automatically does
8198 */
8199 table = alloc_pages_exact(size, gfp_flags);
8200 kmemleak_alloc(table, size, 1, gfp_flags);
8201 }
8202 } while (!table && size > PAGE_SIZE && --log2qty);
8203
8204 if (!table)
8205 panic("Failed to allocate %s hash table\n", tablename);
8206
8207 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8208 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
8209 virt ? "vmalloc" : "linear");
8210
8211 if (_hash_shift)
8212 *_hash_shift = log2qty;
8213 if (_hash_mask)
8214 *_hash_mask = (1 << log2qty) - 1;
8215
8216 return table;
8217}
8218
8219/*
8220 * This function checks whether pageblock includes unmovable pages or not.
8221 *
8222 * PageLRU check without isolation or lru_lock could race so that
8223 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8224 * check without lock_page also may miss some movable non-lru pages at
8225 * race condition. So you can't expect this function should be exact.
8226 *
8227 * Returns a page without holding a reference. If the caller wants to
8228 * dereference that page (e.g., dumping), it has to make sure that it
8229 * cannot get removed (e.g., via memory unplug) concurrently.
8230 *
8231 */
8232struct page *has_unmovable_pages(struct zone *zone, struct page *page,
8233 int migratetype, int flags)
8234{
8235 unsigned long iter = 0;
8236 unsigned long pfn = page_to_pfn(page);
8237
8238 /*
8239 * TODO we could make this much more efficient by not checking every
8240 * page in the range if we know all of them are in MOVABLE_ZONE and
8241 * that the movable zone guarantees that pages are migratable but
8242 * the later is not the case right now unfortunatelly. E.g. movablecore
8243 * can still lead to having bootmem allocations in zone_movable.
8244 */
8245
8246 if (is_migrate_cma_page(page)) {
8247 /*
8248 * CMA allocations (alloc_contig_range) really need to mark
8249 * isolate CMA pageblocks even when they are not movable in fact
8250 * so consider them movable here.
8251 */
8252 if (is_migrate_cma(migratetype))
8253 return NULL;
8254
8255 return page;
8256 }
8257
8258 for (; iter < pageblock_nr_pages; iter++) {
8259 if (!pfn_valid_within(pfn + iter))
8260 continue;
8261
8262 page = pfn_to_page(pfn + iter);
8263
8264 if (PageReserved(page))
8265 return page;
8266
8267 /*
8268 * If the zone is movable and we have ruled out all reserved
8269 * pages then it should be reasonably safe to assume the rest
8270 * is movable.
8271 */
8272 if (zone_idx(zone) == ZONE_MOVABLE)
8273 continue;
8274
8275 /*
8276 * Hugepages are not in LRU lists, but they're movable.
8277 * THPs are on the LRU, but need to be counted as #small pages.
8278 * We need not scan over tail pages because we don't
8279 * handle each tail page individually in migration.
8280 */
8281 if (PageHuge(page) || PageTransCompound(page)) {
8282 struct page *head = compound_head(page);
8283 unsigned int skip_pages;
8284
8285 if (PageHuge(page)) {
8286 if (!hugepage_migration_supported(page_hstate(head)))
8287 return page;
8288 } else if (!PageLRU(head) && !__PageMovable(head)) {
8289 return page;
8290 }
8291
8292 skip_pages = compound_nr(head) - (page - head);
8293 iter += skip_pages - 1;
8294 continue;
8295 }
8296
8297 /*
8298 * We can't use page_count without pin a page
8299 * because another CPU can free compound page.
8300 * This check already skips compound tails of THP
8301 * because their page->_refcount is zero at all time.
8302 */
8303 if (!page_ref_count(page)) {
8304 if (PageBuddy(page))
8305 iter += (1 << page_order(page)) - 1;
8306 continue;
8307 }
8308
8309 /*
8310 * The HWPoisoned page may be not in buddy system, and
8311 * page_count() is not 0.
8312 */
8313 if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
8314 continue;
8315
8316 /*
8317 * We treat all PageOffline() pages as movable when offlining
8318 * to give drivers a chance to decrement their reference count
8319 * in MEM_GOING_OFFLINE in order to indicate that these pages
8320 * can be offlined as there are no direct references anymore.
8321 * For actually unmovable PageOffline() where the driver does
8322 * not support this, we will fail later when trying to actually
8323 * move these pages that still have a reference count > 0.
8324 * (false negatives in this function only)
8325 */
8326 if ((flags & MEMORY_OFFLINE) && PageOffline(page))
8327 continue;
8328
8329 if (__PageMovable(page) || PageLRU(page))
8330 continue;
8331
8332 /*
8333 * If there are RECLAIMABLE pages, we need to check
8334 * it. But now, memory offline itself doesn't call
8335 * shrink_node_slabs() and it still to be fixed.
8336 */
8337 /*
8338 * If the page is not RAM, page_count()should be 0.
8339 * we don't need more check. This is an _used_ not-movable page.
8340 *
8341 * The problematic thing here is PG_reserved pages. PG_reserved
8342 * is set to both of a memory hole page and a _used_ kernel
8343 * page at boot.
8344 */
8345 return page;
8346 }
8347 return NULL;
8348}
8349
8350#ifdef CONFIG_CONTIG_ALLOC
8351static unsigned long pfn_max_align_down(unsigned long pfn)
8352{
8353 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
8354 pageblock_nr_pages) - 1);
8355}
8356
8357static unsigned long pfn_max_align_up(unsigned long pfn)
8358{
8359 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
8360 pageblock_nr_pages));
8361}
8362
8363/* [start, end) must belong to a single zone. */
8364static int __alloc_contig_migrate_range(struct compact_control *cc,
8365 unsigned long start, unsigned long end)
8366{
8367 /* This function is based on compact_zone() from compaction.c. */
8368 unsigned int nr_reclaimed;
8369 unsigned long pfn = start;
8370 unsigned int tries = 0;
8371 int ret = 0;
8372 struct migration_target_control mtc = {
8373 .nid = zone_to_nid(cc->zone),
8374 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
8375 };
8376
8377 migrate_prep();
8378
8379 while (pfn < end || !list_empty(&cc->migratepages)) {
8380 if (fatal_signal_pending(current)) {
8381 ret = -EINTR;
8382 break;
8383 }
8384
8385 if (list_empty(&cc->migratepages)) {
8386 cc->nr_migratepages = 0;
8387 pfn = isolate_migratepages_range(cc, pfn, end);
8388 if (!pfn) {
8389 ret = -EINTR;
8390 break;
8391 }
8392 tries = 0;
8393 } else if (++tries == 5) {
8394 ret = ret < 0 ? ret : -EBUSY;
8395 break;
8396 }
8397
8398 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
8399 &cc->migratepages);
8400 cc->nr_migratepages -= nr_reclaimed;
8401
8402 ret = migrate_pages(&cc->migratepages, alloc_migration_target,
8403 NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE);
8404 }
8405 if (ret < 0) {
8406 putback_movable_pages(&cc->migratepages);
8407 return ret;
8408 }
8409 return 0;
8410}
8411
8412/**
8413 * alloc_contig_range() -- tries to allocate given range of pages
8414 * @start: start PFN to allocate
8415 * @end: one-past-the-last PFN to allocate
8416 * @migratetype: migratetype of the underlaying pageblocks (either
8417 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8418 * in range must have the same migratetype and it must
8419 * be either of the two.
8420 * @gfp_mask: GFP mask to use during compaction
8421 *
8422 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8423 * aligned. The PFN range must belong to a single zone.
8424 *
8425 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8426 * pageblocks in the range. Once isolated, the pageblocks should not
8427 * be modified by others.
8428 *
8429 * Return: zero on success or negative error code. On success all
8430 * pages which PFN is in [start, end) are allocated for the caller and
8431 * need to be freed with free_contig_range().
8432 */
8433int alloc_contig_range(unsigned long start, unsigned long end,
8434 unsigned migratetype, gfp_t gfp_mask)
8435{
8436 unsigned long outer_start, outer_end;
8437 unsigned int order;
8438 int ret = 0;
8439
8440 struct compact_control cc = {
8441 .nr_migratepages = 0,
8442 .order = -1,
8443 .zone = page_zone(pfn_to_page(start)),
8444 .mode = MIGRATE_SYNC,
8445 .ignore_skip_hint = true,
8446 .no_set_skip_hint = true,
8447 .gfp_mask = current_gfp_context(gfp_mask),
8448 .alloc_contig = true,
8449 };
8450 INIT_LIST_HEAD(&cc.migratepages);
8451
8452 /*
8453 * What we do here is we mark all pageblocks in range as
8454 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8455 * have different sizes, and due to the way page allocator
8456 * work, we align the range to biggest of the two pages so
8457 * that page allocator won't try to merge buddies from
8458 * different pageblocks and change MIGRATE_ISOLATE to some
8459 * other migration type.
8460 *
8461 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8462 * migrate the pages from an unaligned range (ie. pages that
8463 * we are interested in). This will put all the pages in
8464 * range back to page allocator as MIGRATE_ISOLATE.
8465 *
8466 * When this is done, we take the pages in range from page
8467 * allocator removing them from the buddy system. This way
8468 * page allocator will never consider using them.
8469 *
8470 * This lets us mark the pageblocks back as
8471 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8472 * aligned range but not in the unaligned, original range are
8473 * put back to page allocator so that buddy can use them.
8474 */
8475
8476 ret = start_isolate_page_range(pfn_max_align_down(start),
8477 pfn_max_align_up(end), migratetype, 0);
8478 if (ret < 0)
8479 return ret;
8480
8481 /*
8482 * In case of -EBUSY, we'd like to know which page causes problem.
8483 * So, just fall through. test_pages_isolated() has a tracepoint
8484 * which will report the busy page.
8485 *
8486 * It is possible that busy pages could become available before
8487 * the call to test_pages_isolated, and the range will actually be
8488 * allocated. So, if we fall through be sure to clear ret so that
8489 * -EBUSY is not accidentally used or returned to caller.
8490 */
8491 ret = __alloc_contig_migrate_range(&cc, start, end);
8492 if (ret && ret != -EBUSY)
8493 goto done;
8494 ret =0;
8495
8496 /*
8497 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8498 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8499 * more, all pages in [start, end) are free in page allocator.
8500 * What we are going to do is to allocate all pages from
8501 * [start, end) (that is remove them from page allocator).
8502 *
8503 * The only problem is that pages at the beginning and at the
8504 * end of interesting range may be not aligned with pages that
8505 * page allocator holds, ie. they can be part of higher order
8506 * pages. Because of this, we reserve the bigger range and
8507 * once this is done free the pages we are not interested in.
8508 *
8509 * We don't have to hold zone->lock here because the pages are
8510 * isolated thus they won't get removed from buddy.
8511 */
8512
8513 lru_add_drain_all();
8514
8515 order = 0;
8516 outer_start = start;
8517 while (!PageBuddy(pfn_to_page(outer_start))) {
8518 if (++order >= MAX_ORDER) {
8519 outer_start = start;
8520 break;
8521 }
8522 outer_start &= ~0UL << order;
8523 }
8524
8525 if (outer_start != start) {
8526 order = page_order(pfn_to_page(outer_start));
8527
8528 /*
8529 * outer_start page could be small order buddy page and
8530 * it doesn't include start page. Adjust outer_start
8531 * in this case to report failed page properly
8532 * on tracepoint in test_pages_isolated()
8533 */
8534 if (outer_start + (1UL << order) <= start)
8535 outer_start = start;
8536 }
8537
8538 /* Make sure the range is really isolated. */
8539 if (test_pages_isolated(outer_start, end, 0)) {
8540 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8541 __func__, outer_start, end);
8542 ret = -EBUSY;
8543 goto done;
8544 }
8545
8546 /* Grab isolated pages from freelists. */
8547 outer_end = isolate_freepages_range(&cc, outer_start, end);
8548 if (!outer_end) {
8549 ret = -EBUSY;
8550 goto done;
8551 }
8552
8553 /* Free head and tail (if any) */
8554 if (start != outer_start)
8555 free_contig_range(outer_start, start - outer_start);
8556 if (end != outer_end)
8557 free_contig_range(end, outer_end - end);
8558
8559done:
8560 undo_isolate_page_range(pfn_max_align_down(start),
8561 pfn_max_align_up(end), migratetype);
8562 return ret;
8563}
8564EXPORT_SYMBOL(alloc_contig_range);
8565
8566static int __alloc_contig_pages(unsigned long start_pfn,
8567 unsigned long nr_pages, gfp_t gfp_mask)
8568{
8569 unsigned long end_pfn = start_pfn + nr_pages;
8570
8571 return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
8572 gfp_mask);
8573}
8574
8575static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
8576 unsigned long nr_pages)
8577{
8578 unsigned long i, end_pfn = start_pfn + nr_pages;
8579 struct page *page;
8580
8581 for (i = start_pfn; i < end_pfn; i++) {
8582 page = pfn_to_online_page(i);
8583 if (!page)
8584 return false;
8585
8586 if (page_zone(page) != z)
8587 return false;
8588
8589 if (PageReserved(page))
8590 return false;
8591
8592 if (page_count(page) > 0)
8593 return false;
8594
8595 if (PageHuge(page))
8596 return false;
8597 }
8598 return true;
8599}
8600
8601static bool zone_spans_last_pfn(const struct zone *zone,
8602 unsigned long start_pfn, unsigned long nr_pages)
8603{
8604 unsigned long last_pfn = start_pfn + nr_pages - 1;
8605
8606 return zone_spans_pfn(zone, last_pfn);
8607}
8608
8609/**
8610 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8611 * @nr_pages: Number of contiguous pages to allocate
8612 * @gfp_mask: GFP mask to limit search and used during compaction
8613 * @nid: Target node
8614 * @nodemask: Mask for other possible nodes
8615 *
8616 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8617 * on an applicable zonelist to find a contiguous pfn range which can then be
8618 * tried for allocation with alloc_contig_range(). This routine is intended
8619 * for allocation requests which can not be fulfilled with the buddy allocator.
8620 *
8621 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8622 * power of two then the alignment is guaranteed to be to the given nr_pages
8623 * (e.g. 1GB request would be aligned to 1GB).
8624 *
8625 * Allocated pages can be freed with free_contig_range() or by manually calling
8626 * __free_page() on each allocated page.
8627 *
8628 * Return: pointer to contiguous pages on success, or NULL if not successful.
8629 */
8630struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
8631 int nid, nodemask_t *nodemask)
8632{
8633 unsigned long ret, pfn, flags;
8634 struct zonelist *zonelist;
8635 struct zone *zone;
8636 struct zoneref *z;
8637
8638 zonelist = node_zonelist(nid, gfp_mask);
8639 for_each_zone_zonelist_nodemask(zone, z, zonelist,
8640 gfp_zone(gfp_mask), nodemask) {
8641 spin_lock_irqsave(&zone->lock, flags);
8642
8643 pfn = ALIGN(zone->zone_start_pfn, nr_pages);
8644 while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
8645 if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
8646 /*
8647 * We release the zone lock here because
8648 * alloc_contig_range() will also lock the zone
8649 * at some point. If there's an allocation
8650 * spinning on this lock, it may win the race
8651 * and cause alloc_contig_range() to fail...
8652 */
8653 spin_unlock_irqrestore(&zone->lock, flags);
8654 ret = __alloc_contig_pages(pfn, nr_pages,
8655 gfp_mask);
8656 if (!ret)
8657 return pfn_to_page(pfn);
8658 spin_lock_irqsave(&zone->lock, flags);
8659 }
8660 pfn += nr_pages;
8661 }
8662 spin_unlock_irqrestore(&zone->lock, flags);
8663 }
8664 return NULL;
8665}
8666#endif /* CONFIG_CONTIG_ALLOC */
8667
8668void free_contig_range(unsigned long pfn, unsigned int nr_pages)
8669{
8670 unsigned int count = 0;
8671
8672 for (; nr_pages--; pfn++) {
8673 struct page *page = pfn_to_page(pfn);
8674
8675 count += page_count(page) != 1;
8676 __free_page(page);
8677 }
8678 WARN(count != 0, "%d pages are still in use!\n", count);
8679}
8680EXPORT_SYMBOL(free_contig_range);
8681
8682/*
8683 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8684 * page high values need to be recalulated.
8685 */
8686void __meminit zone_pcp_update(struct zone *zone)
8687{
8688 mutex_lock(&pcp_batch_high_lock);
8689 __zone_pcp_update(zone);
8690 mutex_unlock(&pcp_batch_high_lock);
8691}
8692
8693void zone_pcp_reset(struct zone *zone)
8694{
8695 unsigned long flags;
8696 int cpu;
8697 struct per_cpu_pageset *pset;
8698
8699 /* avoid races with drain_pages() */
8700 local_irq_save(flags);
8701 if (zone->pageset != &boot_pageset) {
8702 for_each_online_cpu(cpu) {
8703 pset = per_cpu_ptr(zone->pageset, cpu);
8704 drain_zonestat(zone, pset);
8705 }
8706 free_percpu(zone->pageset);
8707 zone->pageset = &boot_pageset;
8708 }
8709 local_irq_restore(flags);
8710}
8711
8712#ifdef CONFIG_MEMORY_HOTREMOVE
8713/*
8714 * All pages in the range must be in a single zone and isolated
8715 * before calling this.
8716 */
8717unsigned long
8718__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
8719{
8720 struct page *page;
8721 struct zone *zone;
8722 unsigned int order;
8723 unsigned long pfn;
8724 unsigned long flags;
8725 unsigned long offlined_pages = 0;
8726
8727 /* find the first valid pfn */
8728 for (pfn = start_pfn; pfn < end_pfn; pfn++)
8729 if (pfn_valid(pfn))
8730 break;
8731 if (pfn == end_pfn)
8732 return offlined_pages;
8733
8734 offline_mem_sections(pfn, end_pfn);
8735 zone = page_zone(pfn_to_page(pfn));
8736 spin_lock_irqsave(&zone->lock, flags);
8737 pfn = start_pfn;
8738 while (pfn < end_pfn) {
8739 if (!pfn_valid(pfn)) {
8740 pfn++;
8741 continue;
8742 }
8743 page = pfn_to_page(pfn);
8744 /*
8745 * The HWPoisoned page may be not in buddy system, and
8746 * page_count() is not 0.
8747 */
8748 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
8749 pfn++;
8750 offlined_pages++;
8751 continue;
8752 }
8753 /*
8754 * At this point all remaining PageOffline() pages have a
8755 * reference count of 0 and can simply be skipped.
8756 */
8757 if (PageOffline(page)) {
8758 BUG_ON(page_count(page));
8759 BUG_ON(PageBuddy(page));
8760 pfn++;
8761 offlined_pages++;
8762 continue;
8763 }
8764
8765 BUG_ON(page_count(page));
8766 BUG_ON(!PageBuddy(page));
8767 order = page_order(page);
8768 offlined_pages += 1 << order;
8769 del_page_from_free_list(page, zone, order);
8770 pfn += (1 << order);
8771 }
8772 spin_unlock_irqrestore(&zone->lock, flags);
8773
8774 return offlined_pages;
8775}
8776#endif
8777
8778bool is_free_buddy_page(struct page *page)
8779{
8780 struct zone *zone = page_zone(page);
8781 unsigned long pfn = page_to_pfn(page);
8782 unsigned long flags;
8783 unsigned int order;
8784
8785 spin_lock_irqsave(&zone->lock, flags);
8786 for (order = 0; order < MAX_ORDER; order++) {
8787 struct page *page_head = page - (pfn & ((1 << order) - 1));
8788
8789 if (PageBuddy(page_head) && page_order(page_head) >= order)
8790 break;
8791 }
8792 spin_unlock_irqrestore(&zone->lock, flags);
8793
8794 return order < MAX_ORDER;
8795}
8796
8797#ifdef CONFIG_MEMORY_FAILURE
8798/*
8799 * Set PG_hwpoison flag if a given page is confirmed to be a free page. This
8800 * test is performed under the zone lock to prevent a race against page
8801 * allocation.
8802 */
8803bool set_hwpoison_free_buddy_page(struct page *page)
8804{
8805 struct zone *zone = page_zone(page);
8806 unsigned long pfn = page_to_pfn(page);
8807 unsigned long flags;
8808 unsigned int order;
8809 bool hwpoisoned = false;
8810
8811 spin_lock_irqsave(&zone->lock, flags);
8812 for (order = 0; order < MAX_ORDER; order++) {
8813 struct page *page_head = page - (pfn & ((1 << order) - 1));
8814
8815 if (PageBuddy(page_head) && page_order(page_head) >= order) {
8816 if (!TestSetPageHWPoison(page))
8817 hwpoisoned = true;
8818 break;
8819 }
8820 }
8821 spin_unlock_irqrestore(&zone->lock, flags);
8822
8823 return hwpoisoned;
8824}
8825#endif