Loading...
1/*
2 * linux/mm/vmstat.c
3 *
4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
6 *
7 * zoned VM statistics
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
10 */
11#include <linux/fs.h>
12#include <linux/mm.h>
13#include <linux/err.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/cpu.h>
17#include <linux/vmstat.h>
18#include <linux/sched.h>
19#include <linux/math64.h>
20#include <linux/writeback.h>
21#include <linux/compaction.h>
22
23#ifdef CONFIG_VM_EVENT_COUNTERS
24DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
25EXPORT_PER_CPU_SYMBOL(vm_event_states);
26
27static void sum_vm_events(unsigned long *ret)
28{
29 int cpu;
30 int i;
31
32 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
33
34 for_each_online_cpu(cpu) {
35 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
36
37 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
38 ret[i] += this->event[i];
39 }
40}
41
42/*
43 * Accumulate the vm event counters across all CPUs.
44 * The result is unavoidably approximate - it can change
45 * during and after execution of this function.
46*/
47void all_vm_events(unsigned long *ret)
48{
49 get_online_cpus();
50 sum_vm_events(ret);
51 put_online_cpus();
52}
53EXPORT_SYMBOL_GPL(all_vm_events);
54
55#ifdef CONFIG_HOTPLUG
56/*
57 * Fold the foreign cpu events into our own.
58 *
59 * This is adding to the events on one processor
60 * but keeps the global counts constant.
61 */
62void vm_events_fold_cpu(int cpu)
63{
64 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
65 int i;
66
67 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
68 count_vm_events(i, fold_state->event[i]);
69 fold_state->event[i] = 0;
70 }
71}
72#endif /* CONFIG_HOTPLUG */
73
74#endif /* CONFIG_VM_EVENT_COUNTERS */
75
76/*
77 * Manage combined zone based / global counters
78 *
79 * vm_stat contains the global counters
80 */
81atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
82EXPORT_SYMBOL(vm_stat);
83
84#ifdef CONFIG_SMP
85
86int calculate_pressure_threshold(struct zone *zone)
87{
88 int threshold;
89 int watermark_distance;
90
91 /*
92 * As vmstats are not up to date, there is drift between the estimated
93 * and real values. For high thresholds and a high number of CPUs, it
94 * is possible for the min watermark to be breached while the estimated
95 * value looks fine. The pressure threshold is a reduced value such
96 * that even the maximum amount of drift will not accidentally breach
97 * the min watermark
98 */
99 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
100 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
101
102 /*
103 * Maximum threshold is 125
104 */
105 threshold = min(125, threshold);
106
107 return threshold;
108}
109
110int calculate_normal_threshold(struct zone *zone)
111{
112 int threshold;
113 int mem; /* memory in 128 MB units */
114
115 /*
116 * The threshold scales with the number of processors and the amount
117 * of memory per zone. More memory means that we can defer updates for
118 * longer, more processors could lead to more contention.
119 * fls() is used to have a cheap way of logarithmic scaling.
120 *
121 * Some sample thresholds:
122 *
123 * Threshold Processors (fls) Zonesize fls(mem+1)
124 * ------------------------------------------------------------------
125 * 8 1 1 0.9-1 GB 4
126 * 16 2 2 0.9-1 GB 4
127 * 20 2 2 1-2 GB 5
128 * 24 2 2 2-4 GB 6
129 * 28 2 2 4-8 GB 7
130 * 32 2 2 8-16 GB 8
131 * 4 2 2 <128M 1
132 * 30 4 3 2-4 GB 5
133 * 48 4 3 8-16 GB 8
134 * 32 8 4 1-2 GB 4
135 * 32 8 4 0.9-1GB 4
136 * 10 16 5 <128M 1
137 * 40 16 5 900M 4
138 * 70 64 7 2-4 GB 5
139 * 84 64 7 4-8 GB 6
140 * 108 512 9 4-8 GB 6
141 * 125 1024 10 8-16 GB 8
142 * 125 1024 10 16-32 GB 9
143 */
144
145 mem = zone->present_pages >> (27 - PAGE_SHIFT);
146
147 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
148
149 /*
150 * Maximum threshold is 125
151 */
152 threshold = min(125, threshold);
153
154 return threshold;
155}
156
157/*
158 * Refresh the thresholds for each zone.
159 */
160void refresh_zone_stat_thresholds(void)
161{
162 struct zone *zone;
163 int cpu;
164 int threshold;
165
166 for_each_populated_zone(zone) {
167 unsigned long max_drift, tolerate_drift;
168
169 threshold = calculate_normal_threshold(zone);
170
171 for_each_online_cpu(cpu)
172 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
173 = threshold;
174
175 /*
176 * Only set percpu_drift_mark if there is a danger that
177 * NR_FREE_PAGES reports the low watermark is ok when in fact
178 * the min watermark could be breached by an allocation
179 */
180 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
181 max_drift = num_online_cpus() * threshold;
182 if (max_drift > tolerate_drift)
183 zone->percpu_drift_mark = high_wmark_pages(zone) +
184 max_drift;
185 }
186}
187
188void set_pgdat_percpu_threshold(pg_data_t *pgdat,
189 int (*calculate_pressure)(struct zone *))
190{
191 struct zone *zone;
192 int cpu;
193 int threshold;
194 int i;
195
196 for (i = 0; i < pgdat->nr_zones; i++) {
197 zone = &pgdat->node_zones[i];
198 if (!zone->percpu_drift_mark)
199 continue;
200
201 threshold = (*calculate_pressure)(zone);
202 for_each_possible_cpu(cpu)
203 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
204 = threshold;
205 }
206}
207
208/*
209 * For use when we know that interrupts are disabled.
210 */
211void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
212 int delta)
213{
214 struct per_cpu_pageset __percpu *pcp = zone->pageset;
215 s8 __percpu *p = pcp->vm_stat_diff + item;
216 long x;
217 long t;
218
219 x = delta + __this_cpu_read(*p);
220
221 t = __this_cpu_read(pcp->stat_threshold);
222
223 if (unlikely(x > t || x < -t)) {
224 zone_page_state_add(x, zone, item);
225 x = 0;
226 }
227 __this_cpu_write(*p, x);
228}
229EXPORT_SYMBOL(__mod_zone_page_state);
230
231/*
232 * Optimized increment and decrement functions.
233 *
234 * These are only for a single page and therefore can take a struct page *
235 * argument instead of struct zone *. This allows the inclusion of the code
236 * generated for page_zone(page) into the optimized functions.
237 *
238 * No overflow check is necessary and therefore the differential can be
239 * incremented or decremented in place which may allow the compilers to
240 * generate better code.
241 * The increment or decrement is known and therefore one boundary check can
242 * be omitted.
243 *
244 * NOTE: These functions are very performance sensitive. Change only
245 * with care.
246 *
247 * Some processors have inc/dec instructions that are atomic vs an interrupt.
248 * However, the code must first determine the differential location in a zone
249 * based on the processor number and then inc/dec the counter. There is no
250 * guarantee without disabling preemption that the processor will not change
251 * in between and therefore the atomicity vs. interrupt cannot be exploited
252 * in a useful way here.
253 */
254void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
255{
256 struct per_cpu_pageset __percpu *pcp = zone->pageset;
257 s8 __percpu *p = pcp->vm_stat_diff + item;
258 s8 v, t;
259
260 v = __this_cpu_inc_return(*p);
261 t = __this_cpu_read(pcp->stat_threshold);
262 if (unlikely(v > t)) {
263 s8 overstep = t >> 1;
264
265 zone_page_state_add(v + overstep, zone, item);
266 __this_cpu_write(*p, -overstep);
267 }
268}
269
270void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
271{
272 __inc_zone_state(page_zone(page), item);
273}
274EXPORT_SYMBOL(__inc_zone_page_state);
275
276void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
277{
278 struct per_cpu_pageset __percpu *pcp = zone->pageset;
279 s8 __percpu *p = pcp->vm_stat_diff + item;
280 s8 v, t;
281
282 v = __this_cpu_dec_return(*p);
283 t = __this_cpu_read(pcp->stat_threshold);
284 if (unlikely(v < - t)) {
285 s8 overstep = t >> 1;
286
287 zone_page_state_add(v - overstep, zone, item);
288 __this_cpu_write(*p, overstep);
289 }
290}
291
292void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
293{
294 __dec_zone_state(page_zone(page), item);
295}
296EXPORT_SYMBOL(__dec_zone_page_state);
297
298#ifdef CONFIG_CMPXCHG_LOCAL
299/*
300 * If we have cmpxchg_local support then we do not need to incur the overhead
301 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
302 *
303 * mod_state() modifies the zone counter state through atomic per cpu
304 * operations.
305 *
306 * Overstep mode specifies how overstep should handled:
307 * 0 No overstepping
308 * 1 Overstepping half of threshold
309 * -1 Overstepping minus half of threshold
310*/
311static inline void mod_state(struct zone *zone,
312 enum zone_stat_item item, int delta, int overstep_mode)
313{
314 struct per_cpu_pageset __percpu *pcp = zone->pageset;
315 s8 __percpu *p = pcp->vm_stat_diff + item;
316 long o, n, t, z;
317
318 do {
319 z = 0; /* overflow to zone counters */
320
321 /*
322 * The fetching of the stat_threshold is racy. We may apply
323 * a counter threshold to the wrong the cpu if we get
324 * rescheduled while executing here. However, the next
325 * counter update will apply the threshold again and
326 * therefore bring the counter under the threshold again.
327 *
328 * Most of the time the thresholds are the same anyways
329 * for all cpus in a zone.
330 */
331 t = this_cpu_read(pcp->stat_threshold);
332
333 o = this_cpu_read(*p);
334 n = delta + o;
335
336 if (n > t || n < -t) {
337 int os = overstep_mode * (t >> 1) ;
338
339 /* Overflow must be added to zone counters */
340 z = n + os;
341 n = -os;
342 }
343 } while (this_cpu_cmpxchg(*p, o, n) != o);
344
345 if (z)
346 zone_page_state_add(z, zone, item);
347}
348
349void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
350 int delta)
351{
352 mod_state(zone, item, delta, 0);
353}
354EXPORT_SYMBOL(mod_zone_page_state);
355
356void inc_zone_state(struct zone *zone, enum zone_stat_item item)
357{
358 mod_state(zone, item, 1, 1);
359}
360
361void inc_zone_page_state(struct page *page, enum zone_stat_item item)
362{
363 mod_state(page_zone(page), item, 1, 1);
364}
365EXPORT_SYMBOL(inc_zone_page_state);
366
367void dec_zone_page_state(struct page *page, enum zone_stat_item item)
368{
369 mod_state(page_zone(page), item, -1, -1);
370}
371EXPORT_SYMBOL(dec_zone_page_state);
372#else
373/*
374 * Use interrupt disable to serialize counter updates
375 */
376void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
377 int delta)
378{
379 unsigned long flags;
380
381 local_irq_save(flags);
382 __mod_zone_page_state(zone, item, delta);
383 local_irq_restore(flags);
384}
385EXPORT_SYMBOL(mod_zone_page_state);
386
387void inc_zone_state(struct zone *zone, enum zone_stat_item item)
388{
389 unsigned long flags;
390
391 local_irq_save(flags);
392 __inc_zone_state(zone, item);
393 local_irq_restore(flags);
394}
395
396void inc_zone_page_state(struct page *page, enum zone_stat_item item)
397{
398 unsigned long flags;
399 struct zone *zone;
400
401 zone = page_zone(page);
402 local_irq_save(flags);
403 __inc_zone_state(zone, item);
404 local_irq_restore(flags);
405}
406EXPORT_SYMBOL(inc_zone_page_state);
407
408void dec_zone_page_state(struct page *page, enum zone_stat_item item)
409{
410 unsigned long flags;
411
412 local_irq_save(flags);
413 __dec_zone_page_state(page, item);
414 local_irq_restore(flags);
415}
416EXPORT_SYMBOL(dec_zone_page_state);
417#endif
418
419/*
420 * Update the zone counters for one cpu.
421 *
422 * The cpu specified must be either the current cpu or a processor that
423 * is not online. If it is the current cpu then the execution thread must
424 * be pinned to the current cpu.
425 *
426 * Note that refresh_cpu_vm_stats strives to only access
427 * node local memory. The per cpu pagesets on remote zones are placed
428 * in the memory local to the processor using that pageset. So the
429 * loop over all zones will access a series of cachelines local to
430 * the processor.
431 *
432 * The call to zone_page_state_add updates the cachelines with the
433 * statistics in the remote zone struct as well as the global cachelines
434 * with the global counters. These could cause remote node cache line
435 * bouncing and will have to be only done when necessary.
436 */
437void refresh_cpu_vm_stats(int cpu)
438{
439 struct zone *zone;
440 int i;
441 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
442
443 for_each_populated_zone(zone) {
444 struct per_cpu_pageset *p;
445
446 p = per_cpu_ptr(zone->pageset, cpu);
447
448 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
449 if (p->vm_stat_diff[i]) {
450 unsigned long flags;
451 int v;
452
453 local_irq_save(flags);
454 v = p->vm_stat_diff[i];
455 p->vm_stat_diff[i] = 0;
456 local_irq_restore(flags);
457 atomic_long_add(v, &zone->vm_stat[i]);
458 global_diff[i] += v;
459#ifdef CONFIG_NUMA
460 /* 3 seconds idle till flush */
461 p->expire = 3;
462#endif
463 }
464 cond_resched();
465#ifdef CONFIG_NUMA
466 /*
467 * Deal with draining the remote pageset of this
468 * processor
469 *
470 * Check if there are pages remaining in this pageset
471 * if not then there is nothing to expire.
472 */
473 if (!p->expire || !p->pcp.count)
474 continue;
475
476 /*
477 * We never drain zones local to this processor.
478 */
479 if (zone_to_nid(zone) == numa_node_id()) {
480 p->expire = 0;
481 continue;
482 }
483
484 p->expire--;
485 if (p->expire)
486 continue;
487
488 if (p->pcp.count)
489 drain_zone_pages(zone, &p->pcp);
490#endif
491 }
492
493 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
494 if (global_diff[i])
495 atomic_long_add(global_diff[i], &vm_stat[i]);
496}
497
498#endif
499
500#ifdef CONFIG_NUMA
501/*
502 * zonelist = the list of zones passed to the allocator
503 * z = the zone from which the allocation occurred.
504 *
505 * Must be called with interrupts disabled.
506 *
507 * When __GFP_OTHER_NODE is set assume the node of the preferred
508 * zone is the local node. This is useful for daemons who allocate
509 * memory on behalf of other processes.
510 */
511void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
512{
513 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
514 __inc_zone_state(z, NUMA_HIT);
515 } else {
516 __inc_zone_state(z, NUMA_MISS);
517 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
518 }
519 if (z->node == ((flags & __GFP_OTHER_NODE) ?
520 preferred_zone->node : numa_node_id()))
521 __inc_zone_state(z, NUMA_LOCAL);
522 else
523 __inc_zone_state(z, NUMA_OTHER);
524}
525#endif
526
527#ifdef CONFIG_COMPACTION
528
529struct contig_page_info {
530 unsigned long free_pages;
531 unsigned long free_blocks_total;
532 unsigned long free_blocks_suitable;
533};
534
535/*
536 * Calculate the number of free pages in a zone, how many contiguous
537 * pages are free and how many are large enough to satisfy an allocation of
538 * the target size. Note that this function makes no attempt to estimate
539 * how many suitable free blocks there *might* be if MOVABLE pages were
540 * migrated. Calculating that is possible, but expensive and can be
541 * figured out from userspace
542 */
543static void fill_contig_page_info(struct zone *zone,
544 unsigned int suitable_order,
545 struct contig_page_info *info)
546{
547 unsigned int order;
548
549 info->free_pages = 0;
550 info->free_blocks_total = 0;
551 info->free_blocks_suitable = 0;
552
553 for (order = 0; order < MAX_ORDER; order++) {
554 unsigned long blocks;
555
556 /* Count number of free blocks */
557 blocks = zone->free_area[order].nr_free;
558 info->free_blocks_total += blocks;
559
560 /* Count free base pages */
561 info->free_pages += blocks << order;
562
563 /* Count the suitable free blocks */
564 if (order >= suitable_order)
565 info->free_blocks_suitable += blocks <<
566 (order - suitable_order);
567 }
568}
569
570/*
571 * A fragmentation index only makes sense if an allocation of a requested
572 * size would fail. If that is true, the fragmentation index indicates
573 * whether external fragmentation or a lack of memory was the problem.
574 * The value can be used to determine if page reclaim or compaction
575 * should be used
576 */
577static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
578{
579 unsigned long requested = 1UL << order;
580
581 if (!info->free_blocks_total)
582 return 0;
583
584 /* Fragmentation index only makes sense when a request would fail */
585 if (info->free_blocks_suitable)
586 return -1000;
587
588 /*
589 * Index is between 0 and 1 so return within 3 decimal places
590 *
591 * 0 => allocation would fail due to lack of memory
592 * 1 => allocation would fail due to fragmentation
593 */
594 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
595}
596
597/* Same as __fragmentation index but allocs contig_page_info on stack */
598int fragmentation_index(struct zone *zone, unsigned int order)
599{
600 struct contig_page_info info;
601
602 fill_contig_page_info(zone, order, &info);
603 return __fragmentation_index(order, &info);
604}
605#endif
606
607#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
608#include <linux/proc_fs.h>
609#include <linux/seq_file.h>
610
611static char * const migratetype_names[MIGRATE_TYPES] = {
612 "Unmovable",
613 "Reclaimable",
614 "Movable",
615 "Reserve",
616 "Isolate",
617};
618
619static void *frag_start(struct seq_file *m, loff_t *pos)
620{
621 pg_data_t *pgdat;
622 loff_t node = *pos;
623 for (pgdat = first_online_pgdat();
624 pgdat && node;
625 pgdat = next_online_pgdat(pgdat))
626 --node;
627
628 return pgdat;
629}
630
631static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
632{
633 pg_data_t *pgdat = (pg_data_t *)arg;
634
635 (*pos)++;
636 return next_online_pgdat(pgdat);
637}
638
639static void frag_stop(struct seq_file *m, void *arg)
640{
641}
642
643/* Walk all the zones in a node and print using a callback */
644static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
645 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
646{
647 struct zone *zone;
648 struct zone *node_zones = pgdat->node_zones;
649 unsigned long flags;
650
651 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
652 if (!populated_zone(zone))
653 continue;
654
655 spin_lock_irqsave(&zone->lock, flags);
656 print(m, pgdat, zone);
657 spin_unlock_irqrestore(&zone->lock, flags);
658 }
659}
660#endif
661
662#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
663#ifdef CONFIG_ZONE_DMA
664#define TEXT_FOR_DMA(xx) xx "_dma",
665#else
666#define TEXT_FOR_DMA(xx)
667#endif
668
669#ifdef CONFIG_ZONE_DMA32
670#define TEXT_FOR_DMA32(xx) xx "_dma32",
671#else
672#define TEXT_FOR_DMA32(xx)
673#endif
674
675#ifdef CONFIG_HIGHMEM
676#define TEXT_FOR_HIGHMEM(xx) xx "_high",
677#else
678#define TEXT_FOR_HIGHMEM(xx)
679#endif
680
681#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
682 TEXT_FOR_HIGHMEM(xx) xx "_movable",
683
684const char * const vmstat_text[] = {
685 /* Zoned VM counters */
686 "nr_free_pages",
687 "nr_inactive_anon",
688 "nr_active_anon",
689 "nr_inactive_file",
690 "nr_active_file",
691 "nr_unevictable",
692 "nr_mlock",
693 "nr_anon_pages",
694 "nr_mapped",
695 "nr_file_pages",
696 "nr_dirty",
697 "nr_writeback",
698 "nr_slab_reclaimable",
699 "nr_slab_unreclaimable",
700 "nr_page_table_pages",
701 "nr_kernel_stack",
702 "nr_unstable",
703 "nr_bounce",
704 "nr_vmscan_write",
705 "nr_writeback_temp",
706 "nr_isolated_anon",
707 "nr_isolated_file",
708 "nr_shmem",
709 "nr_dirtied",
710 "nr_written",
711
712#ifdef CONFIG_NUMA
713 "numa_hit",
714 "numa_miss",
715 "numa_foreign",
716 "numa_interleave",
717 "numa_local",
718 "numa_other",
719#endif
720 "nr_anon_transparent_hugepages",
721 "nr_dirty_threshold",
722 "nr_dirty_background_threshold",
723
724#ifdef CONFIG_VM_EVENT_COUNTERS
725 "pgpgin",
726 "pgpgout",
727 "pswpin",
728 "pswpout",
729
730 TEXTS_FOR_ZONES("pgalloc")
731
732 "pgfree",
733 "pgactivate",
734 "pgdeactivate",
735
736 "pgfault",
737 "pgmajfault",
738
739 TEXTS_FOR_ZONES("pgrefill")
740 TEXTS_FOR_ZONES("pgsteal")
741 TEXTS_FOR_ZONES("pgscan_kswapd")
742 TEXTS_FOR_ZONES("pgscan_direct")
743
744#ifdef CONFIG_NUMA
745 "zone_reclaim_failed",
746#endif
747 "pginodesteal",
748 "slabs_scanned",
749 "kswapd_steal",
750 "kswapd_inodesteal",
751 "kswapd_low_wmark_hit_quickly",
752 "kswapd_high_wmark_hit_quickly",
753 "kswapd_skip_congestion_wait",
754 "pageoutrun",
755 "allocstall",
756
757 "pgrotated",
758
759#ifdef CONFIG_COMPACTION
760 "compact_blocks_moved",
761 "compact_pages_moved",
762 "compact_pagemigrate_failed",
763 "compact_stall",
764 "compact_fail",
765 "compact_success",
766#endif
767
768#ifdef CONFIG_HUGETLB_PAGE
769 "htlb_buddy_alloc_success",
770 "htlb_buddy_alloc_fail",
771#endif
772 "unevictable_pgs_culled",
773 "unevictable_pgs_scanned",
774 "unevictable_pgs_rescued",
775 "unevictable_pgs_mlocked",
776 "unevictable_pgs_munlocked",
777 "unevictable_pgs_cleared",
778 "unevictable_pgs_stranded",
779 "unevictable_pgs_mlockfreed",
780
781#ifdef CONFIG_TRANSPARENT_HUGEPAGE
782 "thp_fault_alloc",
783 "thp_fault_fallback",
784 "thp_collapse_alloc",
785 "thp_collapse_alloc_failed",
786 "thp_split",
787#endif
788
789#endif /* CONFIG_VM_EVENTS_COUNTERS */
790};
791#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
792
793
794#ifdef CONFIG_PROC_FS
795static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
796 struct zone *zone)
797{
798 int order;
799
800 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
801 for (order = 0; order < MAX_ORDER; ++order)
802 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
803 seq_putc(m, '\n');
804}
805
806/*
807 * This walks the free areas for each zone.
808 */
809static int frag_show(struct seq_file *m, void *arg)
810{
811 pg_data_t *pgdat = (pg_data_t *)arg;
812 walk_zones_in_node(m, pgdat, frag_show_print);
813 return 0;
814}
815
816static void pagetypeinfo_showfree_print(struct seq_file *m,
817 pg_data_t *pgdat, struct zone *zone)
818{
819 int order, mtype;
820
821 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
822 seq_printf(m, "Node %4d, zone %8s, type %12s ",
823 pgdat->node_id,
824 zone->name,
825 migratetype_names[mtype]);
826 for (order = 0; order < MAX_ORDER; ++order) {
827 unsigned long freecount = 0;
828 struct free_area *area;
829 struct list_head *curr;
830
831 area = &(zone->free_area[order]);
832
833 list_for_each(curr, &area->free_list[mtype])
834 freecount++;
835 seq_printf(m, "%6lu ", freecount);
836 }
837 seq_putc(m, '\n');
838 }
839}
840
841/* Print out the free pages at each order for each migatetype */
842static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
843{
844 int order;
845 pg_data_t *pgdat = (pg_data_t *)arg;
846
847 /* Print header */
848 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
849 for (order = 0; order < MAX_ORDER; ++order)
850 seq_printf(m, "%6d ", order);
851 seq_putc(m, '\n');
852
853 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
854
855 return 0;
856}
857
858static void pagetypeinfo_showblockcount_print(struct seq_file *m,
859 pg_data_t *pgdat, struct zone *zone)
860{
861 int mtype;
862 unsigned long pfn;
863 unsigned long start_pfn = zone->zone_start_pfn;
864 unsigned long end_pfn = start_pfn + zone->spanned_pages;
865 unsigned long count[MIGRATE_TYPES] = { 0, };
866
867 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
868 struct page *page;
869
870 if (!pfn_valid(pfn))
871 continue;
872
873 page = pfn_to_page(pfn);
874
875 /* Watch for unexpected holes punched in the memmap */
876 if (!memmap_valid_within(pfn, page, zone))
877 continue;
878
879 mtype = get_pageblock_migratetype(page);
880
881 if (mtype < MIGRATE_TYPES)
882 count[mtype]++;
883 }
884
885 /* Print counts */
886 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
887 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
888 seq_printf(m, "%12lu ", count[mtype]);
889 seq_putc(m, '\n');
890}
891
892/* Print out the free pages at each order for each migratetype */
893static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
894{
895 int mtype;
896 pg_data_t *pgdat = (pg_data_t *)arg;
897
898 seq_printf(m, "\n%-23s", "Number of blocks type ");
899 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
900 seq_printf(m, "%12s ", migratetype_names[mtype]);
901 seq_putc(m, '\n');
902 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
903
904 return 0;
905}
906
907/*
908 * This prints out statistics in relation to grouping pages by mobility.
909 * It is expensive to collect so do not constantly read the file.
910 */
911static int pagetypeinfo_show(struct seq_file *m, void *arg)
912{
913 pg_data_t *pgdat = (pg_data_t *)arg;
914
915 /* check memoryless node */
916 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
917 return 0;
918
919 seq_printf(m, "Page block order: %d\n", pageblock_order);
920 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
921 seq_putc(m, '\n');
922 pagetypeinfo_showfree(m, pgdat);
923 pagetypeinfo_showblockcount(m, pgdat);
924
925 return 0;
926}
927
928static const struct seq_operations fragmentation_op = {
929 .start = frag_start,
930 .next = frag_next,
931 .stop = frag_stop,
932 .show = frag_show,
933};
934
935static int fragmentation_open(struct inode *inode, struct file *file)
936{
937 return seq_open(file, &fragmentation_op);
938}
939
940static const struct file_operations fragmentation_file_operations = {
941 .open = fragmentation_open,
942 .read = seq_read,
943 .llseek = seq_lseek,
944 .release = seq_release,
945};
946
947static const struct seq_operations pagetypeinfo_op = {
948 .start = frag_start,
949 .next = frag_next,
950 .stop = frag_stop,
951 .show = pagetypeinfo_show,
952};
953
954static int pagetypeinfo_open(struct inode *inode, struct file *file)
955{
956 return seq_open(file, &pagetypeinfo_op);
957}
958
959static const struct file_operations pagetypeinfo_file_ops = {
960 .open = pagetypeinfo_open,
961 .read = seq_read,
962 .llseek = seq_lseek,
963 .release = seq_release,
964};
965
966static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
967 struct zone *zone)
968{
969 int i;
970 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
971 seq_printf(m,
972 "\n pages free %lu"
973 "\n min %lu"
974 "\n low %lu"
975 "\n high %lu"
976 "\n scanned %lu"
977 "\n spanned %lu"
978 "\n present %lu",
979 zone_page_state(zone, NR_FREE_PAGES),
980 min_wmark_pages(zone),
981 low_wmark_pages(zone),
982 high_wmark_pages(zone),
983 zone->pages_scanned,
984 zone->spanned_pages,
985 zone->present_pages);
986
987 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
988 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
989 zone_page_state(zone, i));
990
991 seq_printf(m,
992 "\n protection: (%lu",
993 zone->lowmem_reserve[0]);
994 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
995 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
996 seq_printf(m,
997 ")"
998 "\n pagesets");
999 for_each_online_cpu(i) {
1000 struct per_cpu_pageset *pageset;
1001
1002 pageset = per_cpu_ptr(zone->pageset, i);
1003 seq_printf(m,
1004 "\n cpu: %i"
1005 "\n count: %i"
1006 "\n high: %i"
1007 "\n batch: %i",
1008 i,
1009 pageset->pcp.count,
1010 pageset->pcp.high,
1011 pageset->pcp.batch);
1012#ifdef CONFIG_SMP
1013 seq_printf(m, "\n vm stats threshold: %d",
1014 pageset->stat_threshold);
1015#endif
1016 }
1017 seq_printf(m,
1018 "\n all_unreclaimable: %u"
1019 "\n start_pfn: %lu"
1020 "\n inactive_ratio: %u",
1021 zone->all_unreclaimable,
1022 zone->zone_start_pfn,
1023 zone->inactive_ratio);
1024 seq_putc(m, '\n');
1025}
1026
1027/*
1028 * Output information about zones in @pgdat.
1029 */
1030static int zoneinfo_show(struct seq_file *m, void *arg)
1031{
1032 pg_data_t *pgdat = (pg_data_t *)arg;
1033 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1034 return 0;
1035}
1036
1037static const struct seq_operations zoneinfo_op = {
1038 .start = frag_start, /* iterate over all zones. The same as in
1039 * fragmentation. */
1040 .next = frag_next,
1041 .stop = frag_stop,
1042 .show = zoneinfo_show,
1043};
1044
1045static int zoneinfo_open(struct inode *inode, struct file *file)
1046{
1047 return seq_open(file, &zoneinfo_op);
1048}
1049
1050static const struct file_operations proc_zoneinfo_file_operations = {
1051 .open = zoneinfo_open,
1052 .read = seq_read,
1053 .llseek = seq_lseek,
1054 .release = seq_release,
1055};
1056
1057enum writeback_stat_item {
1058 NR_DIRTY_THRESHOLD,
1059 NR_DIRTY_BG_THRESHOLD,
1060 NR_VM_WRITEBACK_STAT_ITEMS,
1061};
1062
1063static void *vmstat_start(struct seq_file *m, loff_t *pos)
1064{
1065 unsigned long *v;
1066 int i, stat_items_size;
1067
1068 if (*pos >= ARRAY_SIZE(vmstat_text))
1069 return NULL;
1070 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1071 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1072
1073#ifdef CONFIG_VM_EVENT_COUNTERS
1074 stat_items_size += sizeof(struct vm_event_state);
1075#endif
1076
1077 v = kmalloc(stat_items_size, GFP_KERNEL);
1078 m->private = v;
1079 if (!v)
1080 return ERR_PTR(-ENOMEM);
1081 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1082 v[i] = global_page_state(i);
1083 v += NR_VM_ZONE_STAT_ITEMS;
1084
1085 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1086 v + NR_DIRTY_THRESHOLD);
1087 v += NR_VM_WRITEBACK_STAT_ITEMS;
1088
1089#ifdef CONFIG_VM_EVENT_COUNTERS
1090 all_vm_events(v);
1091 v[PGPGIN] /= 2; /* sectors -> kbytes */
1092 v[PGPGOUT] /= 2;
1093#endif
1094 return (unsigned long *)m->private + *pos;
1095}
1096
1097static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1098{
1099 (*pos)++;
1100 if (*pos >= ARRAY_SIZE(vmstat_text))
1101 return NULL;
1102 return (unsigned long *)m->private + *pos;
1103}
1104
1105static int vmstat_show(struct seq_file *m, void *arg)
1106{
1107 unsigned long *l = arg;
1108 unsigned long off = l - (unsigned long *)m->private;
1109
1110 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1111 return 0;
1112}
1113
1114static void vmstat_stop(struct seq_file *m, void *arg)
1115{
1116 kfree(m->private);
1117 m->private = NULL;
1118}
1119
1120static const struct seq_operations vmstat_op = {
1121 .start = vmstat_start,
1122 .next = vmstat_next,
1123 .stop = vmstat_stop,
1124 .show = vmstat_show,
1125};
1126
1127static int vmstat_open(struct inode *inode, struct file *file)
1128{
1129 return seq_open(file, &vmstat_op);
1130}
1131
1132static const struct file_operations proc_vmstat_file_operations = {
1133 .open = vmstat_open,
1134 .read = seq_read,
1135 .llseek = seq_lseek,
1136 .release = seq_release,
1137};
1138#endif /* CONFIG_PROC_FS */
1139
1140#ifdef CONFIG_SMP
1141static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1142int sysctl_stat_interval __read_mostly = HZ;
1143
1144static void vmstat_update(struct work_struct *w)
1145{
1146 refresh_cpu_vm_stats(smp_processor_id());
1147 schedule_delayed_work(&__get_cpu_var(vmstat_work),
1148 round_jiffies_relative(sysctl_stat_interval));
1149}
1150
1151static void __cpuinit start_cpu_timer(int cpu)
1152{
1153 struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1154
1155 INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
1156 schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1157}
1158
1159/*
1160 * Use the cpu notifier to insure that the thresholds are recalculated
1161 * when necessary.
1162 */
1163static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1164 unsigned long action,
1165 void *hcpu)
1166{
1167 long cpu = (long)hcpu;
1168
1169 switch (action) {
1170 case CPU_ONLINE:
1171 case CPU_ONLINE_FROZEN:
1172 refresh_zone_stat_thresholds();
1173 start_cpu_timer(cpu);
1174 node_set_state(cpu_to_node(cpu), N_CPU);
1175 break;
1176 case CPU_DOWN_PREPARE:
1177 case CPU_DOWN_PREPARE_FROZEN:
1178 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1179 per_cpu(vmstat_work, cpu).work.func = NULL;
1180 break;
1181 case CPU_DOWN_FAILED:
1182 case CPU_DOWN_FAILED_FROZEN:
1183 start_cpu_timer(cpu);
1184 break;
1185 case CPU_DEAD:
1186 case CPU_DEAD_FROZEN:
1187 refresh_zone_stat_thresholds();
1188 break;
1189 default:
1190 break;
1191 }
1192 return NOTIFY_OK;
1193}
1194
1195static struct notifier_block __cpuinitdata vmstat_notifier =
1196 { &vmstat_cpuup_callback, NULL, 0 };
1197#endif
1198
1199static int __init setup_vmstat(void)
1200{
1201#ifdef CONFIG_SMP
1202 int cpu;
1203
1204 register_cpu_notifier(&vmstat_notifier);
1205
1206 for_each_online_cpu(cpu)
1207 start_cpu_timer(cpu);
1208#endif
1209#ifdef CONFIG_PROC_FS
1210 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1211 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1212 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1213 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1214#endif
1215 return 0;
1216}
1217module_init(setup_vmstat)
1218
1219#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1220#include <linux/debugfs.h>
1221
1222static struct dentry *extfrag_debug_root;
1223
1224/*
1225 * Return an index indicating how much of the available free memory is
1226 * unusable for an allocation of the requested size.
1227 */
1228static int unusable_free_index(unsigned int order,
1229 struct contig_page_info *info)
1230{
1231 /* No free memory is interpreted as all free memory is unusable */
1232 if (info->free_pages == 0)
1233 return 1000;
1234
1235 /*
1236 * Index should be a value between 0 and 1. Return a value to 3
1237 * decimal places.
1238 *
1239 * 0 => no fragmentation
1240 * 1 => high fragmentation
1241 */
1242 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1243
1244}
1245
1246static void unusable_show_print(struct seq_file *m,
1247 pg_data_t *pgdat, struct zone *zone)
1248{
1249 unsigned int order;
1250 int index;
1251 struct contig_page_info info;
1252
1253 seq_printf(m, "Node %d, zone %8s ",
1254 pgdat->node_id,
1255 zone->name);
1256 for (order = 0; order < MAX_ORDER; ++order) {
1257 fill_contig_page_info(zone, order, &info);
1258 index = unusable_free_index(order, &info);
1259 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1260 }
1261
1262 seq_putc(m, '\n');
1263}
1264
1265/*
1266 * Display unusable free space index
1267 *
1268 * The unusable free space index measures how much of the available free
1269 * memory cannot be used to satisfy an allocation of a given size and is a
1270 * value between 0 and 1. The higher the value, the more of free memory is
1271 * unusable and by implication, the worse the external fragmentation is. This
1272 * can be expressed as a percentage by multiplying by 100.
1273 */
1274static int unusable_show(struct seq_file *m, void *arg)
1275{
1276 pg_data_t *pgdat = (pg_data_t *)arg;
1277
1278 /* check memoryless node */
1279 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1280 return 0;
1281
1282 walk_zones_in_node(m, pgdat, unusable_show_print);
1283
1284 return 0;
1285}
1286
1287static const struct seq_operations unusable_op = {
1288 .start = frag_start,
1289 .next = frag_next,
1290 .stop = frag_stop,
1291 .show = unusable_show,
1292};
1293
1294static int unusable_open(struct inode *inode, struct file *file)
1295{
1296 return seq_open(file, &unusable_op);
1297}
1298
1299static const struct file_operations unusable_file_ops = {
1300 .open = unusable_open,
1301 .read = seq_read,
1302 .llseek = seq_lseek,
1303 .release = seq_release,
1304};
1305
1306static void extfrag_show_print(struct seq_file *m,
1307 pg_data_t *pgdat, struct zone *zone)
1308{
1309 unsigned int order;
1310 int index;
1311
1312 /* Alloc on stack as interrupts are disabled for zone walk */
1313 struct contig_page_info info;
1314
1315 seq_printf(m, "Node %d, zone %8s ",
1316 pgdat->node_id,
1317 zone->name);
1318 for (order = 0; order < MAX_ORDER; ++order) {
1319 fill_contig_page_info(zone, order, &info);
1320 index = __fragmentation_index(order, &info);
1321 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1322 }
1323
1324 seq_putc(m, '\n');
1325}
1326
1327/*
1328 * Display fragmentation index for orders that allocations would fail for
1329 */
1330static int extfrag_show(struct seq_file *m, void *arg)
1331{
1332 pg_data_t *pgdat = (pg_data_t *)arg;
1333
1334 walk_zones_in_node(m, pgdat, extfrag_show_print);
1335
1336 return 0;
1337}
1338
1339static const struct seq_operations extfrag_op = {
1340 .start = frag_start,
1341 .next = frag_next,
1342 .stop = frag_stop,
1343 .show = extfrag_show,
1344};
1345
1346static int extfrag_open(struct inode *inode, struct file *file)
1347{
1348 return seq_open(file, &extfrag_op);
1349}
1350
1351static const struct file_operations extfrag_file_ops = {
1352 .open = extfrag_open,
1353 .read = seq_read,
1354 .llseek = seq_lseek,
1355 .release = seq_release,
1356};
1357
1358static int __init extfrag_debug_init(void)
1359{
1360 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1361 if (!extfrag_debug_root)
1362 return -ENOMEM;
1363
1364 if (!debugfs_create_file("unusable_index", 0444,
1365 extfrag_debug_root, NULL, &unusable_file_ops))
1366 return -ENOMEM;
1367
1368 if (!debugfs_create_file("extfrag_index", 0444,
1369 extfrag_debug_root, NULL, &extfrag_file_ops))
1370 return -ENOMEM;
1371
1372 return 0;
1373}
1374
1375module_init(extfrag_debug_init);
1376#endif
1/*
2 * linux/mm/vmstat.c
3 *
4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
6 *
7 * zoned VM statistics
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
10 */
11#include <linux/fs.h>
12#include <linux/mm.h>
13#include <linux/err.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/cpu.h>
17#include <linux/vmstat.h>
18#include <linux/sched.h>
19#include <linux/math64.h>
20#include <linux/writeback.h>
21#include <linux/compaction.h>
22#include <linux/mm_inline.h>
23
24#include "internal.h"
25
26#ifdef CONFIG_VM_EVENT_COUNTERS
27DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
28EXPORT_PER_CPU_SYMBOL(vm_event_states);
29
30static void sum_vm_events(unsigned long *ret)
31{
32 int cpu;
33 int i;
34
35 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
36
37 for_each_online_cpu(cpu) {
38 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
39
40 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
41 ret[i] += this->event[i];
42 }
43}
44
45/*
46 * Accumulate the vm event counters across all CPUs.
47 * The result is unavoidably approximate - it can change
48 * during and after execution of this function.
49*/
50void all_vm_events(unsigned long *ret)
51{
52 get_online_cpus();
53 sum_vm_events(ret);
54 put_online_cpus();
55}
56EXPORT_SYMBOL_GPL(all_vm_events);
57
58/*
59 * Fold the foreign cpu events into our own.
60 *
61 * This is adding to the events on one processor
62 * but keeps the global counts constant.
63 */
64void vm_events_fold_cpu(int cpu)
65{
66 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
67 int i;
68
69 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
70 count_vm_events(i, fold_state->event[i]);
71 fold_state->event[i] = 0;
72 }
73}
74
75#endif /* CONFIG_VM_EVENT_COUNTERS */
76
77/*
78 * Manage combined zone based / global counters
79 *
80 * vm_stat contains the global counters
81 */
82atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
83EXPORT_SYMBOL(vm_stat);
84
85#ifdef CONFIG_SMP
86
87int calculate_pressure_threshold(struct zone *zone)
88{
89 int threshold;
90 int watermark_distance;
91
92 /*
93 * As vmstats are not up to date, there is drift between the estimated
94 * and real values. For high thresholds and a high number of CPUs, it
95 * is possible for the min watermark to be breached while the estimated
96 * value looks fine. The pressure threshold is a reduced value such
97 * that even the maximum amount of drift will not accidentally breach
98 * the min watermark
99 */
100 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
101 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
102
103 /*
104 * Maximum threshold is 125
105 */
106 threshold = min(125, threshold);
107
108 return threshold;
109}
110
111int calculate_normal_threshold(struct zone *zone)
112{
113 int threshold;
114 int mem; /* memory in 128 MB units */
115
116 /*
117 * The threshold scales with the number of processors and the amount
118 * of memory per zone. More memory means that we can defer updates for
119 * longer, more processors could lead to more contention.
120 * fls() is used to have a cheap way of logarithmic scaling.
121 *
122 * Some sample thresholds:
123 *
124 * Threshold Processors (fls) Zonesize fls(mem+1)
125 * ------------------------------------------------------------------
126 * 8 1 1 0.9-1 GB 4
127 * 16 2 2 0.9-1 GB 4
128 * 20 2 2 1-2 GB 5
129 * 24 2 2 2-4 GB 6
130 * 28 2 2 4-8 GB 7
131 * 32 2 2 8-16 GB 8
132 * 4 2 2 <128M 1
133 * 30 4 3 2-4 GB 5
134 * 48 4 3 8-16 GB 8
135 * 32 8 4 1-2 GB 4
136 * 32 8 4 0.9-1GB 4
137 * 10 16 5 <128M 1
138 * 40 16 5 900M 4
139 * 70 64 7 2-4 GB 5
140 * 84 64 7 4-8 GB 6
141 * 108 512 9 4-8 GB 6
142 * 125 1024 10 8-16 GB 8
143 * 125 1024 10 16-32 GB 9
144 */
145
146 mem = zone->managed_pages >> (27 - PAGE_SHIFT);
147
148 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
149
150 /*
151 * Maximum threshold is 125
152 */
153 threshold = min(125, threshold);
154
155 return threshold;
156}
157
158/*
159 * Refresh the thresholds for each zone.
160 */
161void refresh_zone_stat_thresholds(void)
162{
163 struct zone *zone;
164 int cpu;
165 int threshold;
166
167 for_each_populated_zone(zone) {
168 unsigned long max_drift, tolerate_drift;
169
170 threshold = calculate_normal_threshold(zone);
171
172 for_each_online_cpu(cpu)
173 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
174 = threshold;
175
176 /*
177 * Only set percpu_drift_mark if there is a danger that
178 * NR_FREE_PAGES reports the low watermark is ok when in fact
179 * the min watermark could be breached by an allocation
180 */
181 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
182 max_drift = num_online_cpus() * threshold;
183 if (max_drift > tolerate_drift)
184 zone->percpu_drift_mark = high_wmark_pages(zone) +
185 max_drift;
186 }
187}
188
189void set_pgdat_percpu_threshold(pg_data_t *pgdat,
190 int (*calculate_pressure)(struct zone *))
191{
192 struct zone *zone;
193 int cpu;
194 int threshold;
195 int i;
196
197 for (i = 0; i < pgdat->nr_zones; i++) {
198 zone = &pgdat->node_zones[i];
199 if (!zone->percpu_drift_mark)
200 continue;
201
202 threshold = (*calculate_pressure)(zone);
203 for_each_possible_cpu(cpu)
204 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
205 = threshold;
206 }
207}
208
209/*
210 * For use when we know that interrupts are disabled.
211 */
212void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
213 int delta)
214{
215 struct per_cpu_pageset __percpu *pcp = zone->pageset;
216 s8 __percpu *p = pcp->vm_stat_diff + item;
217 long x;
218 long t;
219
220 x = delta + __this_cpu_read(*p);
221
222 t = __this_cpu_read(pcp->stat_threshold);
223
224 if (unlikely(x > t || x < -t)) {
225 zone_page_state_add(x, zone, item);
226 x = 0;
227 }
228 __this_cpu_write(*p, x);
229}
230EXPORT_SYMBOL(__mod_zone_page_state);
231
232/*
233 * Optimized increment and decrement functions.
234 *
235 * These are only for a single page and therefore can take a struct page *
236 * argument instead of struct zone *. This allows the inclusion of the code
237 * generated for page_zone(page) into the optimized functions.
238 *
239 * No overflow check is necessary and therefore the differential can be
240 * incremented or decremented in place which may allow the compilers to
241 * generate better code.
242 * The increment or decrement is known and therefore one boundary check can
243 * be omitted.
244 *
245 * NOTE: These functions are very performance sensitive. Change only
246 * with care.
247 *
248 * Some processors have inc/dec instructions that are atomic vs an interrupt.
249 * However, the code must first determine the differential location in a zone
250 * based on the processor number and then inc/dec the counter. There is no
251 * guarantee without disabling preemption that the processor will not change
252 * in between and therefore the atomicity vs. interrupt cannot be exploited
253 * in a useful way here.
254 */
255void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
256{
257 struct per_cpu_pageset __percpu *pcp = zone->pageset;
258 s8 __percpu *p = pcp->vm_stat_diff + item;
259 s8 v, t;
260
261 v = __this_cpu_inc_return(*p);
262 t = __this_cpu_read(pcp->stat_threshold);
263 if (unlikely(v > t)) {
264 s8 overstep = t >> 1;
265
266 zone_page_state_add(v + overstep, zone, item);
267 __this_cpu_write(*p, -overstep);
268 }
269}
270
271void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
272{
273 __inc_zone_state(page_zone(page), item);
274}
275EXPORT_SYMBOL(__inc_zone_page_state);
276
277void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
278{
279 struct per_cpu_pageset __percpu *pcp = zone->pageset;
280 s8 __percpu *p = pcp->vm_stat_diff + item;
281 s8 v, t;
282
283 v = __this_cpu_dec_return(*p);
284 t = __this_cpu_read(pcp->stat_threshold);
285 if (unlikely(v < - t)) {
286 s8 overstep = t >> 1;
287
288 zone_page_state_add(v - overstep, zone, item);
289 __this_cpu_write(*p, overstep);
290 }
291}
292
293void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
294{
295 __dec_zone_state(page_zone(page), item);
296}
297EXPORT_SYMBOL(__dec_zone_page_state);
298
299#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
300/*
301 * If we have cmpxchg_local support then we do not need to incur the overhead
302 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
303 *
304 * mod_state() modifies the zone counter state through atomic per cpu
305 * operations.
306 *
307 * Overstep mode specifies how overstep should handled:
308 * 0 No overstepping
309 * 1 Overstepping half of threshold
310 * -1 Overstepping minus half of threshold
311*/
312static inline void mod_state(struct zone *zone,
313 enum zone_stat_item item, int delta, int overstep_mode)
314{
315 struct per_cpu_pageset __percpu *pcp = zone->pageset;
316 s8 __percpu *p = pcp->vm_stat_diff + item;
317 long o, n, t, z;
318
319 do {
320 z = 0; /* overflow to zone counters */
321
322 /*
323 * The fetching of the stat_threshold is racy. We may apply
324 * a counter threshold to the wrong the cpu if we get
325 * rescheduled while executing here. However, the next
326 * counter update will apply the threshold again and
327 * therefore bring the counter under the threshold again.
328 *
329 * Most of the time the thresholds are the same anyways
330 * for all cpus in a zone.
331 */
332 t = this_cpu_read(pcp->stat_threshold);
333
334 o = this_cpu_read(*p);
335 n = delta + o;
336
337 if (n > t || n < -t) {
338 int os = overstep_mode * (t >> 1) ;
339
340 /* Overflow must be added to zone counters */
341 z = n + os;
342 n = -os;
343 }
344 } while (this_cpu_cmpxchg(*p, o, n) != o);
345
346 if (z)
347 zone_page_state_add(z, zone, item);
348}
349
350void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
351 int delta)
352{
353 mod_state(zone, item, delta, 0);
354}
355EXPORT_SYMBOL(mod_zone_page_state);
356
357void inc_zone_state(struct zone *zone, enum zone_stat_item item)
358{
359 mod_state(zone, item, 1, 1);
360}
361
362void inc_zone_page_state(struct page *page, enum zone_stat_item item)
363{
364 mod_state(page_zone(page), item, 1, 1);
365}
366EXPORT_SYMBOL(inc_zone_page_state);
367
368void dec_zone_page_state(struct page *page, enum zone_stat_item item)
369{
370 mod_state(page_zone(page), item, -1, -1);
371}
372EXPORT_SYMBOL(dec_zone_page_state);
373#else
374/*
375 * Use interrupt disable to serialize counter updates
376 */
377void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
378 int delta)
379{
380 unsigned long flags;
381
382 local_irq_save(flags);
383 __mod_zone_page_state(zone, item, delta);
384 local_irq_restore(flags);
385}
386EXPORT_SYMBOL(mod_zone_page_state);
387
388void inc_zone_state(struct zone *zone, enum zone_stat_item item)
389{
390 unsigned long flags;
391
392 local_irq_save(flags);
393 __inc_zone_state(zone, item);
394 local_irq_restore(flags);
395}
396
397void inc_zone_page_state(struct page *page, enum zone_stat_item item)
398{
399 unsigned long flags;
400 struct zone *zone;
401
402 zone = page_zone(page);
403 local_irq_save(flags);
404 __inc_zone_state(zone, item);
405 local_irq_restore(flags);
406}
407EXPORT_SYMBOL(inc_zone_page_state);
408
409void dec_zone_page_state(struct page *page, enum zone_stat_item item)
410{
411 unsigned long flags;
412
413 local_irq_save(flags);
414 __dec_zone_page_state(page, item);
415 local_irq_restore(flags);
416}
417EXPORT_SYMBOL(dec_zone_page_state);
418#endif
419
420static inline void fold_diff(int *diff)
421{
422 int i;
423
424 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
425 if (diff[i])
426 atomic_long_add(diff[i], &vm_stat[i]);
427}
428
429/*
430 * Update the zone counters for the current cpu.
431 *
432 * Note that refresh_cpu_vm_stats strives to only access
433 * node local memory. The per cpu pagesets on remote zones are placed
434 * in the memory local to the processor using that pageset. So the
435 * loop over all zones will access a series of cachelines local to
436 * the processor.
437 *
438 * The call to zone_page_state_add updates the cachelines with the
439 * statistics in the remote zone struct as well as the global cachelines
440 * with the global counters. These could cause remote node cache line
441 * bouncing and will have to be only done when necessary.
442 */
443static void refresh_cpu_vm_stats(void)
444{
445 struct zone *zone;
446 int i;
447 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
448
449 for_each_populated_zone(zone) {
450 struct per_cpu_pageset __percpu *p = zone->pageset;
451
452 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
453 int v;
454
455 v = this_cpu_xchg(p->vm_stat_diff[i], 0);
456 if (v) {
457
458 atomic_long_add(v, &zone->vm_stat[i]);
459 global_diff[i] += v;
460#ifdef CONFIG_NUMA
461 /* 3 seconds idle till flush */
462 __this_cpu_write(p->expire, 3);
463#endif
464 }
465 }
466 cond_resched();
467#ifdef CONFIG_NUMA
468 /*
469 * Deal with draining the remote pageset of this
470 * processor
471 *
472 * Check if there are pages remaining in this pageset
473 * if not then there is nothing to expire.
474 */
475 if (!__this_cpu_read(p->expire) ||
476 !__this_cpu_read(p->pcp.count))
477 continue;
478
479 /*
480 * We never drain zones local to this processor.
481 */
482 if (zone_to_nid(zone) == numa_node_id()) {
483 __this_cpu_write(p->expire, 0);
484 continue;
485 }
486
487
488 if (__this_cpu_dec_return(p->expire))
489 continue;
490
491 if (__this_cpu_read(p->pcp.count))
492 drain_zone_pages(zone, __this_cpu_ptr(&p->pcp));
493#endif
494 }
495 fold_diff(global_diff);
496}
497
498/*
499 * Fold the data for an offline cpu into the global array.
500 * There cannot be any access by the offline cpu and therefore
501 * synchronization is simplified.
502 */
503void cpu_vm_stats_fold(int cpu)
504{
505 struct zone *zone;
506 int i;
507 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
508
509 for_each_populated_zone(zone) {
510 struct per_cpu_pageset *p;
511
512 p = per_cpu_ptr(zone->pageset, cpu);
513
514 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
515 if (p->vm_stat_diff[i]) {
516 int v;
517
518 v = p->vm_stat_diff[i];
519 p->vm_stat_diff[i] = 0;
520 atomic_long_add(v, &zone->vm_stat[i]);
521 global_diff[i] += v;
522 }
523 }
524
525 fold_diff(global_diff);
526}
527
528/*
529 * this is only called if !populated_zone(zone), which implies no other users of
530 * pset->vm_stat_diff[] exsist.
531 */
532void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
533{
534 int i;
535
536 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
537 if (pset->vm_stat_diff[i]) {
538 int v = pset->vm_stat_diff[i];
539 pset->vm_stat_diff[i] = 0;
540 atomic_long_add(v, &zone->vm_stat[i]);
541 atomic_long_add(v, &vm_stat[i]);
542 }
543}
544#endif
545
546#ifdef CONFIG_NUMA
547/*
548 * zonelist = the list of zones passed to the allocator
549 * z = the zone from which the allocation occurred.
550 *
551 * Must be called with interrupts disabled.
552 *
553 * When __GFP_OTHER_NODE is set assume the node of the preferred
554 * zone is the local node. This is useful for daemons who allocate
555 * memory on behalf of other processes.
556 */
557void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
558{
559 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
560 __inc_zone_state(z, NUMA_HIT);
561 } else {
562 __inc_zone_state(z, NUMA_MISS);
563 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
564 }
565 if (z->node == ((flags & __GFP_OTHER_NODE) ?
566 preferred_zone->node : numa_node_id()))
567 __inc_zone_state(z, NUMA_LOCAL);
568 else
569 __inc_zone_state(z, NUMA_OTHER);
570}
571#endif
572
573#ifdef CONFIG_COMPACTION
574
575struct contig_page_info {
576 unsigned long free_pages;
577 unsigned long free_blocks_total;
578 unsigned long free_blocks_suitable;
579};
580
581/*
582 * Calculate the number of free pages in a zone, how many contiguous
583 * pages are free and how many are large enough to satisfy an allocation of
584 * the target size. Note that this function makes no attempt to estimate
585 * how many suitable free blocks there *might* be if MOVABLE pages were
586 * migrated. Calculating that is possible, but expensive and can be
587 * figured out from userspace
588 */
589static void fill_contig_page_info(struct zone *zone,
590 unsigned int suitable_order,
591 struct contig_page_info *info)
592{
593 unsigned int order;
594
595 info->free_pages = 0;
596 info->free_blocks_total = 0;
597 info->free_blocks_suitable = 0;
598
599 for (order = 0; order < MAX_ORDER; order++) {
600 unsigned long blocks;
601
602 /* Count number of free blocks */
603 blocks = zone->free_area[order].nr_free;
604 info->free_blocks_total += blocks;
605
606 /* Count free base pages */
607 info->free_pages += blocks << order;
608
609 /* Count the suitable free blocks */
610 if (order >= suitable_order)
611 info->free_blocks_suitable += blocks <<
612 (order - suitable_order);
613 }
614}
615
616/*
617 * A fragmentation index only makes sense if an allocation of a requested
618 * size would fail. If that is true, the fragmentation index indicates
619 * whether external fragmentation or a lack of memory was the problem.
620 * The value can be used to determine if page reclaim or compaction
621 * should be used
622 */
623static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
624{
625 unsigned long requested = 1UL << order;
626
627 if (!info->free_blocks_total)
628 return 0;
629
630 /* Fragmentation index only makes sense when a request would fail */
631 if (info->free_blocks_suitable)
632 return -1000;
633
634 /*
635 * Index is between 0 and 1 so return within 3 decimal places
636 *
637 * 0 => allocation would fail due to lack of memory
638 * 1 => allocation would fail due to fragmentation
639 */
640 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
641}
642
643/* Same as __fragmentation index but allocs contig_page_info on stack */
644int fragmentation_index(struct zone *zone, unsigned int order)
645{
646 struct contig_page_info info;
647
648 fill_contig_page_info(zone, order, &info);
649 return __fragmentation_index(order, &info);
650}
651#endif
652
653#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
654#include <linux/proc_fs.h>
655#include <linux/seq_file.h>
656
657static char * const migratetype_names[MIGRATE_TYPES] = {
658 "Unmovable",
659 "Reclaimable",
660 "Movable",
661 "Reserve",
662#ifdef CONFIG_CMA
663 "CMA",
664#endif
665#ifdef CONFIG_MEMORY_ISOLATION
666 "Isolate",
667#endif
668};
669
670static void *frag_start(struct seq_file *m, loff_t *pos)
671{
672 pg_data_t *pgdat;
673 loff_t node = *pos;
674 for (pgdat = first_online_pgdat();
675 pgdat && node;
676 pgdat = next_online_pgdat(pgdat))
677 --node;
678
679 return pgdat;
680}
681
682static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
683{
684 pg_data_t *pgdat = (pg_data_t *)arg;
685
686 (*pos)++;
687 return next_online_pgdat(pgdat);
688}
689
690static void frag_stop(struct seq_file *m, void *arg)
691{
692}
693
694/* Walk all the zones in a node and print using a callback */
695static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
696 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
697{
698 struct zone *zone;
699 struct zone *node_zones = pgdat->node_zones;
700 unsigned long flags;
701
702 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
703 if (!populated_zone(zone))
704 continue;
705
706 spin_lock_irqsave(&zone->lock, flags);
707 print(m, pgdat, zone);
708 spin_unlock_irqrestore(&zone->lock, flags);
709 }
710}
711#endif
712
713#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
714#ifdef CONFIG_ZONE_DMA
715#define TEXT_FOR_DMA(xx) xx "_dma",
716#else
717#define TEXT_FOR_DMA(xx)
718#endif
719
720#ifdef CONFIG_ZONE_DMA32
721#define TEXT_FOR_DMA32(xx) xx "_dma32",
722#else
723#define TEXT_FOR_DMA32(xx)
724#endif
725
726#ifdef CONFIG_HIGHMEM
727#define TEXT_FOR_HIGHMEM(xx) xx "_high",
728#else
729#define TEXT_FOR_HIGHMEM(xx)
730#endif
731
732#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
733 TEXT_FOR_HIGHMEM(xx) xx "_movable",
734
735const char * const vmstat_text[] = {
736 /* Zoned VM counters */
737 "nr_free_pages",
738 "nr_alloc_batch",
739 "nr_inactive_anon",
740 "nr_active_anon",
741 "nr_inactive_file",
742 "nr_active_file",
743 "nr_unevictable",
744 "nr_mlock",
745 "nr_anon_pages",
746 "nr_mapped",
747 "nr_file_pages",
748 "nr_dirty",
749 "nr_writeback",
750 "nr_slab_reclaimable",
751 "nr_slab_unreclaimable",
752 "nr_page_table_pages",
753 "nr_kernel_stack",
754 "nr_unstable",
755 "nr_bounce",
756 "nr_vmscan_write",
757 "nr_vmscan_immediate_reclaim",
758 "nr_writeback_temp",
759 "nr_isolated_anon",
760 "nr_isolated_file",
761 "nr_shmem",
762 "nr_dirtied",
763 "nr_written",
764
765#ifdef CONFIG_NUMA
766 "numa_hit",
767 "numa_miss",
768 "numa_foreign",
769 "numa_interleave",
770 "numa_local",
771 "numa_other",
772#endif
773 "workingset_refault",
774 "workingset_activate",
775 "workingset_nodereclaim",
776 "nr_anon_transparent_hugepages",
777 "nr_free_cma",
778 "nr_dirty_threshold",
779 "nr_dirty_background_threshold",
780
781#ifdef CONFIG_VM_EVENT_COUNTERS
782 "pgpgin",
783 "pgpgout",
784 "pswpin",
785 "pswpout",
786
787 TEXTS_FOR_ZONES("pgalloc")
788
789 "pgfree",
790 "pgactivate",
791 "pgdeactivate",
792
793 "pgfault",
794 "pgmajfault",
795
796 TEXTS_FOR_ZONES("pgrefill")
797 TEXTS_FOR_ZONES("pgsteal_kswapd")
798 TEXTS_FOR_ZONES("pgsteal_direct")
799 TEXTS_FOR_ZONES("pgscan_kswapd")
800 TEXTS_FOR_ZONES("pgscan_direct")
801 "pgscan_direct_throttle",
802
803#ifdef CONFIG_NUMA
804 "zone_reclaim_failed",
805#endif
806 "pginodesteal",
807 "slabs_scanned",
808 "kswapd_inodesteal",
809 "kswapd_low_wmark_hit_quickly",
810 "kswapd_high_wmark_hit_quickly",
811 "pageoutrun",
812 "allocstall",
813
814 "pgrotated",
815
816 "drop_pagecache",
817 "drop_slab",
818
819#ifdef CONFIG_NUMA_BALANCING
820 "numa_pte_updates",
821 "numa_huge_pte_updates",
822 "numa_hint_faults",
823 "numa_hint_faults_local",
824 "numa_pages_migrated",
825#endif
826#ifdef CONFIG_MIGRATION
827 "pgmigrate_success",
828 "pgmigrate_fail",
829#endif
830#ifdef CONFIG_COMPACTION
831 "compact_migrate_scanned",
832 "compact_free_scanned",
833 "compact_isolated",
834 "compact_stall",
835 "compact_fail",
836 "compact_success",
837#endif
838
839#ifdef CONFIG_HUGETLB_PAGE
840 "htlb_buddy_alloc_success",
841 "htlb_buddy_alloc_fail",
842#endif
843 "unevictable_pgs_culled",
844 "unevictable_pgs_scanned",
845 "unevictable_pgs_rescued",
846 "unevictable_pgs_mlocked",
847 "unevictable_pgs_munlocked",
848 "unevictable_pgs_cleared",
849 "unevictable_pgs_stranded",
850
851#ifdef CONFIG_TRANSPARENT_HUGEPAGE
852 "thp_fault_alloc",
853 "thp_fault_fallback",
854 "thp_collapse_alloc",
855 "thp_collapse_alloc_failed",
856 "thp_split",
857 "thp_zero_page_alloc",
858 "thp_zero_page_alloc_failed",
859#endif
860#ifdef CONFIG_DEBUG_TLBFLUSH
861#ifdef CONFIG_SMP
862 "nr_tlb_remote_flush",
863 "nr_tlb_remote_flush_received",
864#endif /* CONFIG_SMP */
865 "nr_tlb_local_flush_all",
866 "nr_tlb_local_flush_one",
867#endif /* CONFIG_DEBUG_TLBFLUSH */
868
869#endif /* CONFIG_VM_EVENTS_COUNTERS */
870};
871#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
872
873
874#ifdef CONFIG_PROC_FS
875static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
876 struct zone *zone)
877{
878 int order;
879
880 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
881 for (order = 0; order < MAX_ORDER; ++order)
882 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
883 seq_putc(m, '\n');
884}
885
886/*
887 * This walks the free areas for each zone.
888 */
889static int frag_show(struct seq_file *m, void *arg)
890{
891 pg_data_t *pgdat = (pg_data_t *)arg;
892 walk_zones_in_node(m, pgdat, frag_show_print);
893 return 0;
894}
895
896static void pagetypeinfo_showfree_print(struct seq_file *m,
897 pg_data_t *pgdat, struct zone *zone)
898{
899 int order, mtype;
900
901 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
902 seq_printf(m, "Node %4d, zone %8s, type %12s ",
903 pgdat->node_id,
904 zone->name,
905 migratetype_names[mtype]);
906 for (order = 0; order < MAX_ORDER; ++order) {
907 unsigned long freecount = 0;
908 struct free_area *area;
909 struct list_head *curr;
910
911 area = &(zone->free_area[order]);
912
913 list_for_each(curr, &area->free_list[mtype])
914 freecount++;
915 seq_printf(m, "%6lu ", freecount);
916 }
917 seq_putc(m, '\n');
918 }
919}
920
921/* Print out the free pages at each order for each migatetype */
922static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
923{
924 int order;
925 pg_data_t *pgdat = (pg_data_t *)arg;
926
927 /* Print header */
928 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
929 for (order = 0; order < MAX_ORDER; ++order)
930 seq_printf(m, "%6d ", order);
931 seq_putc(m, '\n');
932
933 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
934
935 return 0;
936}
937
938static void pagetypeinfo_showblockcount_print(struct seq_file *m,
939 pg_data_t *pgdat, struct zone *zone)
940{
941 int mtype;
942 unsigned long pfn;
943 unsigned long start_pfn = zone->zone_start_pfn;
944 unsigned long end_pfn = zone_end_pfn(zone);
945 unsigned long count[MIGRATE_TYPES] = { 0, };
946
947 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
948 struct page *page;
949
950 if (!pfn_valid(pfn))
951 continue;
952
953 page = pfn_to_page(pfn);
954
955 /* Watch for unexpected holes punched in the memmap */
956 if (!memmap_valid_within(pfn, page, zone))
957 continue;
958
959 mtype = get_pageblock_migratetype(page);
960
961 if (mtype < MIGRATE_TYPES)
962 count[mtype]++;
963 }
964
965 /* Print counts */
966 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
967 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
968 seq_printf(m, "%12lu ", count[mtype]);
969 seq_putc(m, '\n');
970}
971
972/* Print out the free pages at each order for each migratetype */
973static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
974{
975 int mtype;
976 pg_data_t *pgdat = (pg_data_t *)arg;
977
978 seq_printf(m, "\n%-23s", "Number of blocks type ");
979 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
980 seq_printf(m, "%12s ", migratetype_names[mtype]);
981 seq_putc(m, '\n');
982 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
983
984 return 0;
985}
986
987/*
988 * This prints out statistics in relation to grouping pages by mobility.
989 * It is expensive to collect so do not constantly read the file.
990 */
991static int pagetypeinfo_show(struct seq_file *m, void *arg)
992{
993 pg_data_t *pgdat = (pg_data_t *)arg;
994
995 /* check memoryless node */
996 if (!node_state(pgdat->node_id, N_MEMORY))
997 return 0;
998
999 seq_printf(m, "Page block order: %d\n", pageblock_order);
1000 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1001 seq_putc(m, '\n');
1002 pagetypeinfo_showfree(m, pgdat);
1003 pagetypeinfo_showblockcount(m, pgdat);
1004
1005 return 0;
1006}
1007
1008static const struct seq_operations fragmentation_op = {
1009 .start = frag_start,
1010 .next = frag_next,
1011 .stop = frag_stop,
1012 .show = frag_show,
1013};
1014
1015static int fragmentation_open(struct inode *inode, struct file *file)
1016{
1017 return seq_open(file, &fragmentation_op);
1018}
1019
1020static const struct file_operations fragmentation_file_operations = {
1021 .open = fragmentation_open,
1022 .read = seq_read,
1023 .llseek = seq_lseek,
1024 .release = seq_release,
1025};
1026
1027static const struct seq_operations pagetypeinfo_op = {
1028 .start = frag_start,
1029 .next = frag_next,
1030 .stop = frag_stop,
1031 .show = pagetypeinfo_show,
1032};
1033
1034static int pagetypeinfo_open(struct inode *inode, struct file *file)
1035{
1036 return seq_open(file, &pagetypeinfo_op);
1037}
1038
1039static const struct file_operations pagetypeinfo_file_ops = {
1040 .open = pagetypeinfo_open,
1041 .read = seq_read,
1042 .llseek = seq_lseek,
1043 .release = seq_release,
1044};
1045
1046static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1047 struct zone *zone)
1048{
1049 int i;
1050 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1051 seq_printf(m,
1052 "\n pages free %lu"
1053 "\n min %lu"
1054 "\n low %lu"
1055 "\n high %lu"
1056 "\n scanned %lu"
1057 "\n spanned %lu"
1058 "\n present %lu"
1059 "\n managed %lu",
1060 zone_page_state(zone, NR_FREE_PAGES),
1061 min_wmark_pages(zone),
1062 low_wmark_pages(zone),
1063 high_wmark_pages(zone),
1064 zone->pages_scanned,
1065 zone->spanned_pages,
1066 zone->present_pages,
1067 zone->managed_pages);
1068
1069 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1070 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
1071 zone_page_state(zone, i));
1072
1073 seq_printf(m,
1074 "\n protection: (%lu",
1075 zone->lowmem_reserve[0]);
1076 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1077 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
1078 seq_printf(m,
1079 ")"
1080 "\n pagesets");
1081 for_each_online_cpu(i) {
1082 struct per_cpu_pageset *pageset;
1083
1084 pageset = per_cpu_ptr(zone->pageset, i);
1085 seq_printf(m,
1086 "\n cpu: %i"
1087 "\n count: %i"
1088 "\n high: %i"
1089 "\n batch: %i",
1090 i,
1091 pageset->pcp.count,
1092 pageset->pcp.high,
1093 pageset->pcp.batch);
1094#ifdef CONFIG_SMP
1095 seq_printf(m, "\n vm stats threshold: %d",
1096 pageset->stat_threshold);
1097#endif
1098 }
1099 seq_printf(m,
1100 "\n all_unreclaimable: %u"
1101 "\n start_pfn: %lu"
1102 "\n inactive_ratio: %u",
1103 !zone_reclaimable(zone),
1104 zone->zone_start_pfn,
1105 zone->inactive_ratio);
1106 seq_putc(m, '\n');
1107}
1108
1109/*
1110 * Output information about zones in @pgdat.
1111 */
1112static int zoneinfo_show(struct seq_file *m, void *arg)
1113{
1114 pg_data_t *pgdat = (pg_data_t *)arg;
1115 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1116 return 0;
1117}
1118
1119static const struct seq_operations zoneinfo_op = {
1120 .start = frag_start, /* iterate over all zones. The same as in
1121 * fragmentation. */
1122 .next = frag_next,
1123 .stop = frag_stop,
1124 .show = zoneinfo_show,
1125};
1126
1127static int zoneinfo_open(struct inode *inode, struct file *file)
1128{
1129 return seq_open(file, &zoneinfo_op);
1130}
1131
1132static const struct file_operations proc_zoneinfo_file_operations = {
1133 .open = zoneinfo_open,
1134 .read = seq_read,
1135 .llseek = seq_lseek,
1136 .release = seq_release,
1137};
1138
1139enum writeback_stat_item {
1140 NR_DIRTY_THRESHOLD,
1141 NR_DIRTY_BG_THRESHOLD,
1142 NR_VM_WRITEBACK_STAT_ITEMS,
1143};
1144
1145static void *vmstat_start(struct seq_file *m, loff_t *pos)
1146{
1147 unsigned long *v;
1148 int i, stat_items_size;
1149
1150 if (*pos >= ARRAY_SIZE(vmstat_text))
1151 return NULL;
1152 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1153 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1154
1155#ifdef CONFIG_VM_EVENT_COUNTERS
1156 stat_items_size += sizeof(struct vm_event_state);
1157#endif
1158
1159 v = kmalloc(stat_items_size, GFP_KERNEL);
1160 m->private = v;
1161 if (!v)
1162 return ERR_PTR(-ENOMEM);
1163 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1164 v[i] = global_page_state(i);
1165 v += NR_VM_ZONE_STAT_ITEMS;
1166
1167 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1168 v + NR_DIRTY_THRESHOLD);
1169 v += NR_VM_WRITEBACK_STAT_ITEMS;
1170
1171#ifdef CONFIG_VM_EVENT_COUNTERS
1172 all_vm_events(v);
1173 v[PGPGIN] /= 2; /* sectors -> kbytes */
1174 v[PGPGOUT] /= 2;
1175#endif
1176 return (unsigned long *)m->private + *pos;
1177}
1178
1179static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1180{
1181 (*pos)++;
1182 if (*pos >= ARRAY_SIZE(vmstat_text))
1183 return NULL;
1184 return (unsigned long *)m->private + *pos;
1185}
1186
1187static int vmstat_show(struct seq_file *m, void *arg)
1188{
1189 unsigned long *l = arg;
1190 unsigned long off = l - (unsigned long *)m->private;
1191
1192 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1193 return 0;
1194}
1195
1196static void vmstat_stop(struct seq_file *m, void *arg)
1197{
1198 kfree(m->private);
1199 m->private = NULL;
1200}
1201
1202static const struct seq_operations vmstat_op = {
1203 .start = vmstat_start,
1204 .next = vmstat_next,
1205 .stop = vmstat_stop,
1206 .show = vmstat_show,
1207};
1208
1209static int vmstat_open(struct inode *inode, struct file *file)
1210{
1211 return seq_open(file, &vmstat_op);
1212}
1213
1214static const struct file_operations proc_vmstat_file_operations = {
1215 .open = vmstat_open,
1216 .read = seq_read,
1217 .llseek = seq_lseek,
1218 .release = seq_release,
1219};
1220#endif /* CONFIG_PROC_FS */
1221
1222#ifdef CONFIG_SMP
1223static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1224int sysctl_stat_interval __read_mostly = HZ;
1225
1226static void vmstat_update(struct work_struct *w)
1227{
1228 refresh_cpu_vm_stats();
1229 schedule_delayed_work(&__get_cpu_var(vmstat_work),
1230 round_jiffies_relative(sysctl_stat_interval));
1231}
1232
1233static void start_cpu_timer(int cpu)
1234{
1235 struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1236
1237 INIT_DEFERRABLE_WORK(work, vmstat_update);
1238 schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1239}
1240
1241static void vmstat_cpu_dead(int node)
1242{
1243 int cpu;
1244
1245 get_online_cpus();
1246 for_each_online_cpu(cpu)
1247 if (cpu_to_node(cpu) == node)
1248 goto end;
1249
1250 node_clear_state(node, N_CPU);
1251end:
1252 put_online_cpus();
1253}
1254
1255/*
1256 * Use the cpu notifier to insure that the thresholds are recalculated
1257 * when necessary.
1258 */
1259static int vmstat_cpuup_callback(struct notifier_block *nfb,
1260 unsigned long action,
1261 void *hcpu)
1262{
1263 long cpu = (long)hcpu;
1264
1265 switch (action) {
1266 case CPU_ONLINE:
1267 case CPU_ONLINE_FROZEN:
1268 refresh_zone_stat_thresholds();
1269 start_cpu_timer(cpu);
1270 node_set_state(cpu_to_node(cpu), N_CPU);
1271 break;
1272 case CPU_DOWN_PREPARE:
1273 case CPU_DOWN_PREPARE_FROZEN:
1274 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1275 per_cpu(vmstat_work, cpu).work.func = NULL;
1276 break;
1277 case CPU_DOWN_FAILED:
1278 case CPU_DOWN_FAILED_FROZEN:
1279 start_cpu_timer(cpu);
1280 break;
1281 case CPU_DEAD:
1282 case CPU_DEAD_FROZEN:
1283 refresh_zone_stat_thresholds();
1284 vmstat_cpu_dead(cpu_to_node(cpu));
1285 break;
1286 default:
1287 break;
1288 }
1289 return NOTIFY_OK;
1290}
1291
1292static struct notifier_block vmstat_notifier =
1293 { &vmstat_cpuup_callback, NULL, 0 };
1294#endif
1295
1296static int __init setup_vmstat(void)
1297{
1298#ifdef CONFIG_SMP
1299 int cpu;
1300
1301 cpu_notifier_register_begin();
1302 __register_cpu_notifier(&vmstat_notifier);
1303
1304 for_each_online_cpu(cpu) {
1305 start_cpu_timer(cpu);
1306 node_set_state(cpu_to_node(cpu), N_CPU);
1307 }
1308 cpu_notifier_register_done();
1309#endif
1310#ifdef CONFIG_PROC_FS
1311 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1312 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1313 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1314 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1315#endif
1316 return 0;
1317}
1318module_init(setup_vmstat)
1319
1320#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1321#include <linux/debugfs.h>
1322
1323
1324/*
1325 * Return an index indicating how much of the available free memory is
1326 * unusable for an allocation of the requested size.
1327 */
1328static int unusable_free_index(unsigned int order,
1329 struct contig_page_info *info)
1330{
1331 /* No free memory is interpreted as all free memory is unusable */
1332 if (info->free_pages == 0)
1333 return 1000;
1334
1335 /*
1336 * Index should be a value between 0 and 1. Return a value to 3
1337 * decimal places.
1338 *
1339 * 0 => no fragmentation
1340 * 1 => high fragmentation
1341 */
1342 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1343
1344}
1345
1346static void unusable_show_print(struct seq_file *m,
1347 pg_data_t *pgdat, struct zone *zone)
1348{
1349 unsigned int order;
1350 int index;
1351 struct contig_page_info info;
1352
1353 seq_printf(m, "Node %d, zone %8s ",
1354 pgdat->node_id,
1355 zone->name);
1356 for (order = 0; order < MAX_ORDER; ++order) {
1357 fill_contig_page_info(zone, order, &info);
1358 index = unusable_free_index(order, &info);
1359 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1360 }
1361
1362 seq_putc(m, '\n');
1363}
1364
1365/*
1366 * Display unusable free space index
1367 *
1368 * The unusable free space index measures how much of the available free
1369 * memory cannot be used to satisfy an allocation of a given size and is a
1370 * value between 0 and 1. The higher the value, the more of free memory is
1371 * unusable and by implication, the worse the external fragmentation is. This
1372 * can be expressed as a percentage by multiplying by 100.
1373 */
1374static int unusable_show(struct seq_file *m, void *arg)
1375{
1376 pg_data_t *pgdat = (pg_data_t *)arg;
1377
1378 /* check memoryless node */
1379 if (!node_state(pgdat->node_id, N_MEMORY))
1380 return 0;
1381
1382 walk_zones_in_node(m, pgdat, unusable_show_print);
1383
1384 return 0;
1385}
1386
1387static const struct seq_operations unusable_op = {
1388 .start = frag_start,
1389 .next = frag_next,
1390 .stop = frag_stop,
1391 .show = unusable_show,
1392};
1393
1394static int unusable_open(struct inode *inode, struct file *file)
1395{
1396 return seq_open(file, &unusable_op);
1397}
1398
1399static const struct file_operations unusable_file_ops = {
1400 .open = unusable_open,
1401 .read = seq_read,
1402 .llseek = seq_lseek,
1403 .release = seq_release,
1404};
1405
1406static void extfrag_show_print(struct seq_file *m,
1407 pg_data_t *pgdat, struct zone *zone)
1408{
1409 unsigned int order;
1410 int index;
1411
1412 /* Alloc on stack as interrupts are disabled for zone walk */
1413 struct contig_page_info info;
1414
1415 seq_printf(m, "Node %d, zone %8s ",
1416 pgdat->node_id,
1417 zone->name);
1418 for (order = 0; order < MAX_ORDER; ++order) {
1419 fill_contig_page_info(zone, order, &info);
1420 index = __fragmentation_index(order, &info);
1421 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1422 }
1423
1424 seq_putc(m, '\n');
1425}
1426
1427/*
1428 * Display fragmentation index for orders that allocations would fail for
1429 */
1430static int extfrag_show(struct seq_file *m, void *arg)
1431{
1432 pg_data_t *pgdat = (pg_data_t *)arg;
1433
1434 walk_zones_in_node(m, pgdat, extfrag_show_print);
1435
1436 return 0;
1437}
1438
1439static const struct seq_operations extfrag_op = {
1440 .start = frag_start,
1441 .next = frag_next,
1442 .stop = frag_stop,
1443 .show = extfrag_show,
1444};
1445
1446static int extfrag_open(struct inode *inode, struct file *file)
1447{
1448 return seq_open(file, &extfrag_op);
1449}
1450
1451static const struct file_operations extfrag_file_ops = {
1452 .open = extfrag_open,
1453 .read = seq_read,
1454 .llseek = seq_lseek,
1455 .release = seq_release,
1456};
1457
1458static int __init extfrag_debug_init(void)
1459{
1460 struct dentry *extfrag_debug_root;
1461
1462 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1463 if (!extfrag_debug_root)
1464 return -ENOMEM;
1465
1466 if (!debugfs_create_file("unusable_index", 0444,
1467 extfrag_debug_root, NULL, &unusable_file_ops))
1468 goto fail;
1469
1470 if (!debugfs_create_file("extfrag_index", 0444,
1471 extfrag_debug_root, NULL, &extfrag_file_ops))
1472 goto fail;
1473
1474 return 0;
1475fail:
1476 debugfs_remove_recursive(extfrag_debug_root);
1477 return -ENOMEM;
1478}
1479
1480module_init(extfrag_debug_init);
1481#endif