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/kmemcheck.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/stop_machine.h>
  46#include <linux/sort.h>
  47#include <linux/pfn.h>
  48#include <linux/backing-dev.h>
  49#include <linux/fault-inject.h>
  50#include <linux/page-isolation.h>
  51#include <linux/page_cgroup.h>
  52#include <linux/debugobjects.h>
  53#include <linux/kmemleak.h>
  54#include <linux/memory.h>
  55#include <linux/compaction.h>
  56#include <trace/events/kmem.h>
  57#include <linux/ftrace_event.h>
  58#include <linux/memcontrol.h>
  59#include <linux/prefetch.h>
 
 
 
 
 
  60
 
  61#include <asm/tlbflush.h>
  62#include <asm/div64.h>
  63#include "internal.h"
  64
 
 
 
  65#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
  66DEFINE_PER_CPU(int, numa_node);
  67EXPORT_PER_CPU_SYMBOL(numa_node);
  68#endif
  69
  70#ifdef CONFIG_HAVE_MEMORYLESS_NODES
  71/*
  72 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
  73 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
  74 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
  75 * defined in <linux/topology.h>.
  76 */
  77DEFINE_PER_CPU(int, _numa_mem_);		/* Kernel "local memory" node */
  78EXPORT_PER_CPU_SYMBOL(_numa_mem_);
  79#endif
  80
  81/*
  82 * Array of node states.
  83 */
  84nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
  85	[N_POSSIBLE] = NODE_MASK_ALL,
  86	[N_ONLINE] = { { [0] = 1UL } },
  87#ifndef CONFIG_NUMA
  88	[N_NORMAL_MEMORY] = { { [0] = 1UL } },
  89#ifdef CONFIG_HIGHMEM
  90	[N_HIGH_MEMORY] = { { [0] = 1UL } },
  91#endif
 
 
 
  92	[N_CPU] = { { [0] = 1UL } },
  93#endif	/* NUMA */
  94};
  95EXPORT_SYMBOL(node_states);
  96
 
 
 
  97unsigned long totalram_pages __read_mostly;
  98unsigned long totalreserve_pages __read_mostly;
 
 
 
 
 
 
 
 
  99int percpu_pagelist_fraction;
 100gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
 101
 102#ifdef CONFIG_PM_SLEEP
 103/*
 104 * The following functions are used by the suspend/hibernate code to temporarily
 105 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
 106 * while devices are suspended.  To avoid races with the suspend/hibernate code,
 107 * they should always be called with pm_mutex held (gfp_allowed_mask also should
 108 * only be modified with pm_mutex held, unless the suspend/hibernate code is
 109 * guaranteed not to run in parallel with that modification).
 110 */
 111
 112static gfp_t saved_gfp_mask;
 113
 114void pm_restore_gfp_mask(void)
 115{
 116	WARN_ON(!mutex_is_locked(&pm_mutex));
 117	if (saved_gfp_mask) {
 118		gfp_allowed_mask = saved_gfp_mask;
 119		saved_gfp_mask = 0;
 120	}
 121}
 122
 123void pm_restrict_gfp_mask(void)
 124{
 125	WARN_ON(!mutex_is_locked(&pm_mutex));
 126	WARN_ON(saved_gfp_mask);
 127	saved_gfp_mask = gfp_allowed_mask;
 128	gfp_allowed_mask &= ~GFP_IOFS;
 129}
 
 
 
 
 
 
 
 130#endif /* CONFIG_PM_SLEEP */
 131
 132#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
 133int pageblock_order __read_mostly;
 134#endif
 135
 136static void __free_pages_ok(struct page *page, unsigned int order);
 137
 138/*
 139 * results with 256, 32 in the lowmem_reserve sysctl:
 140 *	1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
 141 *	1G machine -> (16M dma, 784M normal, 224M high)
 142 *	NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
 143 *	HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
 144 *	HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
 145 *
 146 * TBD: should special case ZONE_DMA32 machines here - in those we normally
 147 * don't need any ZONE_NORMAL reservation
 148 */
 149int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
 150#ifdef CONFIG_ZONE_DMA
 151	 256,
 152#endif
 153#ifdef CONFIG_ZONE_DMA32
 154	 256,
 155#endif
 156#ifdef CONFIG_HIGHMEM
 157	 32,
 158#endif
 159	 32,
 160};
 161
 162EXPORT_SYMBOL(totalram_pages);
 163
 164static char * const zone_names[MAX_NR_ZONES] = {
 165#ifdef CONFIG_ZONE_DMA
 166	 "DMA",
 167#endif
 168#ifdef CONFIG_ZONE_DMA32
 169	 "DMA32",
 170#endif
 171	 "Normal",
 172#ifdef CONFIG_HIGHMEM
 173	 "HighMem",
 174#endif
 175	 "Movable",
 176};
 177
 178int min_free_kbytes = 1024;
 
 179
 180static unsigned long __meminitdata nr_kernel_pages;
 181static unsigned long __meminitdata nr_all_pages;
 182static unsigned long __meminitdata dma_reserve;
 183
 184#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
 185  /*
 186   * MAX_ACTIVE_REGIONS determines the maximum number of distinct
 187   * ranges of memory (RAM) that may be registered with add_active_range().
 188   * Ranges passed to add_active_range() will be merged if possible
 189   * so the number of times add_active_range() can be called is
 190   * related to the number of nodes and the number of holes
 191   */
 192  #ifdef CONFIG_MAX_ACTIVE_REGIONS
 193    /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
 194    #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
 195  #else
 196    #if MAX_NUMNODES >= 32
 197      /* If there can be many nodes, allow up to 50 holes per node */
 198      #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
 199    #else
 200      /* By default, allow up to 256 distinct regions */
 201      #define MAX_ACTIVE_REGIONS 256
 202    #endif
 203  #endif
 204
 205  static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
 206  static int __meminitdata nr_nodemap_entries;
 207  static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
 208  static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
 209  static unsigned long __initdata required_kernelcore;
 210  static unsigned long __initdata required_movablecore;
 211  static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
 212
 213  /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 214  int movable_zone;
 215  EXPORT_SYMBOL(movable_zone);
 216#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 217
 218#if MAX_NUMNODES > 1
 219int nr_node_ids __read_mostly = MAX_NUMNODES;
 220int nr_online_nodes __read_mostly = 1;
 221EXPORT_SYMBOL(nr_node_ids);
 222EXPORT_SYMBOL(nr_online_nodes);
 223#endif
 224
 225int page_group_by_mobility_disabled __read_mostly;
 226
 227static void set_pageblock_migratetype(struct page *page, int migratetype)
 228{
 229
 230	if (unlikely(page_group_by_mobility_disabled))
 231		migratetype = MIGRATE_UNMOVABLE;
 232
 233	set_pageblock_flags_group(page, (unsigned long)migratetype,
 234					PB_migrate, PB_migrate_end);
 235}
 236
 237bool oom_killer_disabled __read_mostly;
 238
 239#ifdef CONFIG_DEBUG_VM
 240static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
 241{
 242	int ret = 0;
 243	unsigned seq;
 244	unsigned long pfn = page_to_pfn(page);
 
 245
 246	do {
 247		seq = zone_span_seqbegin(zone);
 248		if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
 249			ret = 1;
 250		else if (pfn < zone->zone_start_pfn)
 251			ret = 1;
 252	} while (zone_span_seqretry(zone, seq));
 253
 
 
 
 
 254	return ret;
 255}
 256
 257static int page_is_consistent(struct zone *zone, struct page *page)
 258{
 259	if (!pfn_valid_within(page_to_pfn(page)))
 260		return 0;
 261	if (zone != page_zone(page))
 262		return 0;
 263
 264	return 1;
 265}
 266/*
 267 * Temporary debugging check for pages not lying within a given zone.
 268 */
 269static int bad_range(struct zone *zone, struct page *page)
 270{
 271	if (page_outside_zone_boundaries(zone, page))
 272		return 1;
 273	if (!page_is_consistent(zone, page))
 274		return 1;
 275
 276	return 0;
 277}
 278#else
 279static inline int bad_range(struct zone *zone, struct page *page)
 280{
 281	return 0;
 282}
 283#endif
 284
 285static void bad_page(struct page *page)
 
 286{
 287	static unsigned long resume;
 288	static unsigned long nr_shown;
 289	static unsigned long nr_unshown;
 290
 291	/* Don't complain about poisoned pages */
 292	if (PageHWPoison(page)) {
 293		reset_page_mapcount(page); /* remove PageBuddy */
 294		return;
 295	}
 296
 297	/*
 298	 * Allow a burst of 60 reports, then keep quiet for that minute;
 299	 * or allow a steady drip of one report per second.
 300	 */
 301	if (nr_shown == 60) {
 302		if (time_before(jiffies, resume)) {
 303			nr_unshown++;
 304			goto out;
 305		}
 306		if (nr_unshown) {
 307			printk(KERN_ALERT
 308			      "BUG: Bad page state: %lu messages suppressed\n",
 309				nr_unshown);
 310			nr_unshown = 0;
 311		}
 312		nr_shown = 0;
 313	}
 314	if (nr_shown++ == 0)
 315		resume = jiffies + 60 * HZ;
 316
 317	printk(KERN_ALERT "BUG: Bad page state in process %s  pfn:%05lx\n",
 318		current->comm, page_to_pfn(page));
 319	dump_page(page);
 320
 
 321	dump_stack();
 322out:
 323	/* Leave bad fields for debug, except PageBuddy could make trouble */
 324	reset_page_mapcount(page); /* remove PageBuddy */
 325	add_taint(TAINT_BAD_PAGE);
 326}
 327
 328/*
 329 * Higher-order pages are called "compound pages".  They are structured thusly:
 330 *
 331 * The first PAGE_SIZE page is called the "head page".
 332 *
 333 * The remaining PAGE_SIZE pages are called "tail pages".
 334 *
 335 * All pages have PG_compound set.  All pages have their ->private pointing at
 336 * the head page (even the head page has this).
 337 *
 338 * The first tail page's ->lru.next holds the address of the compound page's
 339 * put_page() function.  Its ->lru.prev holds the order of allocation.
 340 * This usage means that zero-order pages may not be compound.
 341 */
 342
 343static void free_compound_page(struct page *page)
 344{
 345	__free_pages_ok(page, compound_order(page));
 346}
 347
 348void prep_compound_page(struct page *page, unsigned long order)
 349{
 350	int i;
 351	int nr_pages = 1 << order;
 352
 353	set_compound_page_dtor(page, free_compound_page);
 354	set_compound_order(page, order);
 355	__SetPageHead(page);
 356	for (i = 1; i < nr_pages; i++) {
 357		struct page *p = page + i;
 358
 359		__SetPageTail(p);
 360		p->first_page = page;
 
 
 
 361	}
 362}
 363
 364/* update __split_huge_page_refcount if you change this function */
 365static int destroy_compound_page(struct page *page, unsigned long order)
 366{
 367	int i;
 368	int nr_pages = 1 << order;
 369	int bad = 0;
 370
 371	if (unlikely(compound_order(page) != order) ||
 372	    unlikely(!PageHead(page))) {
 373		bad_page(page);
 374		bad++;
 375	}
 376
 377	__ClearPageHead(page);
 378
 379	for (i = 1; i < nr_pages; i++) {
 380		struct page *p = page + i;
 381
 382		if (unlikely(!PageTail(p) || (p->first_page != page))) {
 383			bad_page(page);
 
 
 
 384			bad++;
 385		}
 386		__ClearPageTail(p);
 387	}
 388
 389	return bad;
 390}
 391
 392static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
 393{
 394	int i;
 395
 396	/*
 397	 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
 398	 * and __GFP_HIGHMEM from hard or soft interrupt context.
 399	 */
 400	VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
 401	for (i = 0; i < (1 << order); i++)
 402		clear_highpage(page + i);
 403}
 404
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 405static inline void set_page_order(struct page *page, int order)
 406{
 407	set_page_private(page, order);
 408	__SetPageBuddy(page);
 409}
 410
 411static inline void rmv_page_order(struct page *page)
 412{
 413	__ClearPageBuddy(page);
 414	set_page_private(page, 0);
 415}
 416
 417/*
 418 * Locate the struct page for both the matching buddy in our
 419 * pair (buddy1) and the combined O(n+1) page they form (page).
 420 *
 421 * 1) Any buddy B1 will have an order O twin B2 which satisfies
 422 * the following equation:
 423 *     B2 = B1 ^ (1 << O)
 424 * For example, if the starting buddy (buddy2) is #8 its order
 425 * 1 buddy is #10:
 426 *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
 427 *
 428 * 2) Any buddy B will have an order O+1 parent P which
 429 * satisfies the following equation:
 430 *     P = B & ~(1 << O)
 431 *
 432 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
 433 */
 434static inline unsigned long
 435__find_buddy_index(unsigned long page_idx, unsigned int order)
 436{
 437	return page_idx ^ (1 << order);
 438}
 439
 440/*
 441 * This function checks whether a page is free && is the buddy
 442 * we can do coalesce a page and its buddy if
 443 * (a) the buddy is not in a hole &&
 444 * (b) the buddy is in the buddy system &&
 445 * (c) a page and its buddy have the same order &&
 446 * (d) a page and its buddy are in the same zone.
 447 *
 448 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
 449 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
 
 
 450 *
 451 * For recording page's order, we use page_private(page).
 452 */
 453static inline int page_is_buddy(struct page *page, struct page *buddy,
 454								int order)
 455{
 456	if (!pfn_valid_within(page_to_pfn(buddy)))
 457		return 0;
 458
 459	if (page_zone_id(page) != page_zone_id(buddy))
 460		return 0;
 461
 
 
 
 
 
 462	if (PageBuddy(buddy) && page_order(buddy) == order) {
 463		VM_BUG_ON(page_count(buddy) != 0);
 464		return 1;
 465	}
 466	return 0;
 467}
 468
 469/*
 470 * Freeing function for a buddy system allocator.
 471 *
 472 * The concept of a buddy system is to maintain direct-mapped table
 473 * (containing bit values) for memory blocks of various "orders".
 474 * The bottom level table contains the map for the smallest allocatable
 475 * units of memory (here, pages), and each level above it describes
 476 * pairs of units from the levels below, hence, "buddies".
 477 * At a high level, all that happens here is marking the table entry
 478 * at the bottom level available, and propagating the changes upward
 479 * as necessary, plus some accounting needed to play nicely with other
 480 * parts of the VM system.
 481 * At each level, we keep a list of pages, which are heads of continuous
 482 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
 483 * order is recorded in page_private(page) field.
 
 484 * So when we are allocating or freeing one, we can derive the state of the
 485 * other.  That is, if we allocate a small block, and both were   
 486 * free, the remainder of the region must be split into blocks.   
 487 * If a block is freed, and its buddy is also free, then this
 488 * triggers coalescing into a block of larger size.            
 489 *
 490 * -- wli
 491 */
 492
 493static inline void __free_one_page(struct page *page,
 494		struct zone *zone, unsigned int order,
 495		int migratetype)
 496{
 497	unsigned long page_idx;
 498	unsigned long combined_idx;
 499	unsigned long uninitialized_var(buddy_idx);
 500	struct page *buddy;
 501
 
 
 502	if (unlikely(PageCompound(page)))
 503		if (unlikely(destroy_compound_page(page, order)))
 504			return;
 505
 506	VM_BUG_ON(migratetype == -1);
 507
 508	page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
 509
 510	VM_BUG_ON(page_idx & ((1 << order) - 1));
 511	VM_BUG_ON(bad_range(zone, page));
 512
 513	while (order < MAX_ORDER-1) {
 514		buddy_idx = __find_buddy_index(page_idx, order);
 515		buddy = page + (buddy_idx - page_idx);
 516		if (!page_is_buddy(page, buddy, order))
 517			break;
 518
 519		/* Our buddy is free, merge with it and move up one order. */
 520		list_del(&buddy->lru);
 521		zone->free_area[order].nr_free--;
 522		rmv_page_order(buddy);
 
 
 
 
 
 
 
 
 
 523		combined_idx = buddy_idx & page_idx;
 524		page = page + (combined_idx - page_idx);
 525		page_idx = combined_idx;
 526		order++;
 527	}
 528	set_page_order(page, order);
 529
 530	/*
 531	 * If this is not the largest possible page, check if the buddy
 532	 * of the next-highest order is free. If it is, it's possible
 533	 * that pages are being freed that will coalesce soon. In case,
 534	 * that is happening, add the free page to the tail of the list
 535	 * so it's less likely to be used soon and more likely to be merged
 536	 * as a higher order page
 537	 */
 538	if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
 539		struct page *higher_page, *higher_buddy;
 540		combined_idx = buddy_idx & page_idx;
 541		higher_page = page + (combined_idx - page_idx);
 542		buddy_idx = __find_buddy_index(combined_idx, order + 1);
 543		higher_buddy = page + (buddy_idx - combined_idx);
 544		if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
 545			list_add_tail(&page->lru,
 546				&zone->free_area[order].free_list[migratetype]);
 547			goto out;
 548		}
 549	}
 550
 551	list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
 552out:
 553	zone->free_area[order].nr_free++;
 554}
 555
 556/*
 557 * free_page_mlock() -- clean up attempts to free and mlocked() page.
 558 * Page should not be on lru, so no need to fix that up.
 559 * free_pages_check() will verify...
 560 */
 561static inline void free_page_mlock(struct page *page)
 562{
 563	__dec_zone_page_state(page, NR_MLOCK);
 564	__count_vm_event(UNEVICTABLE_MLOCKFREED);
 565}
 566
 567static inline int free_pages_check(struct page *page)
 568{
 569	if (unlikely(page_mapcount(page) |
 570		(page->mapping != NULL)  |
 571		(atomic_read(&page->_count) != 0) |
 572		(page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
 573		(mem_cgroup_bad_page_check(page)))) {
 574		bad_page(page);
 
 
 
 
 
 
 
 
 
 
 
 575		return 1;
 576	}
 
 577	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
 578		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
 579	return 0;
 580}
 581
 582/*
 583 * Frees a number of pages from the PCP lists
 584 * Assumes all pages on list are in same zone, and of same order.
 585 * count is the number of pages to free.
 586 *
 587 * If the zone was previously in an "all pages pinned" state then look to
 588 * see if this freeing clears that state.
 589 *
 590 * And clear the zone's pages_scanned counter, to hold off the "all pages are
 591 * pinned" detection logic.
 592 */
 593static void free_pcppages_bulk(struct zone *zone, int count,
 594					struct per_cpu_pages *pcp)
 595{
 596	int migratetype = 0;
 597	int batch_free = 0;
 598	int to_free = count;
 599
 600	spin_lock(&zone->lock);
 601	zone->all_unreclaimable = 0;
 602	zone->pages_scanned = 0;
 603
 604	while (to_free) {
 605		struct page *page;
 606		struct list_head *list;
 607
 608		/*
 609		 * Remove pages from lists in a round-robin fashion. A
 610		 * batch_free count is maintained that is incremented when an
 611		 * empty list is encountered.  This is so more pages are freed
 612		 * off fuller lists instead of spinning excessively around empty
 613		 * lists
 614		 */
 615		do {
 616			batch_free++;
 617			if (++migratetype == MIGRATE_PCPTYPES)
 618				migratetype = 0;
 619			list = &pcp->lists[migratetype];
 620		} while (list_empty(list));
 621
 622		/* This is the only non-empty list. Free them all. */
 623		if (batch_free == MIGRATE_PCPTYPES)
 624			batch_free = to_free;
 625
 626		do {
 
 
 627			page = list_entry(list->prev, struct page, lru);
 628			/* must delete as __free_one_page list manipulates */
 629			list_del(&page->lru);
 
 630			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
 631			__free_one_page(page, zone, 0, page_private(page));
 632			trace_mm_page_pcpu_drain(page, 0, page_private(page));
 
 
 
 
 
 633		} while (--to_free && --batch_free && !list_empty(list));
 634	}
 635	__mod_zone_page_state(zone, NR_FREE_PAGES, count);
 636	spin_unlock(&zone->lock);
 637}
 638
 639static void free_one_page(struct zone *zone, struct page *page, int order,
 640				int migratetype)
 641{
 642	spin_lock(&zone->lock);
 643	zone->all_unreclaimable = 0;
 644	zone->pages_scanned = 0;
 645
 646	__free_one_page(page, zone, order, migratetype);
 647	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
 
 648	spin_unlock(&zone->lock);
 649}
 650
 651static bool free_pages_prepare(struct page *page, unsigned int order)
 652{
 653	int i;
 654	int bad = 0;
 655
 656	trace_mm_page_free_direct(page, order);
 657	kmemcheck_free_shadow(page, order);
 658
 659	if (PageAnon(page))
 660		page->mapping = NULL;
 661	for (i = 0; i < (1 << order); i++)
 662		bad += free_pages_check(page + i);
 663	if (bad)
 664		return false;
 665
 666	if (!PageHighMem(page)) {
 667		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
 
 668		debug_check_no_obj_freed(page_address(page),
 669					   PAGE_SIZE << order);
 670	}
 671	arch_free_page(page, order);
 672	kernel_map_pages(page, 1 << order, 0);
 673
 674	return true;
 675}
 676
 677static void __free_pages_ok(struct page *page, unsigned int order)
 678{
 679	unsigned long flags;
 680	int wasMlocked = __TestClearPageMlocked(page);
 681
 682	if (!free_pages_prepare(page, order))
 683		return;
 684
 685	local_irq_save(flags);
 686	if (unlikely(wasMlocked))
 687		free_page_mlock(page);
 688	__count_vm_events(PGFREE, 1 << order);
 689	free_one_page(page_zone(page), page, order,
 690					get_pageblock_migratetype(page));
 
 691	local_irq_restore(flags);
 692}
 693
 694/*
 695 * permit the bootmem allocator to evade page validation on high-order frees
 696 */
 697void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
 698{
 699	if (order == 0) {
 700		__ClearPageReserved(page);
 701		set_page_count(page, 0);
 702		set_page_refcounted(page);
 703		__free_page(page);
 704	} else {
 705		int loop;
 
 
 
 
 
 706
 707		prefetchw(page);
 708		for (loop = 0; loop < BITS_PER_LONG; loop++) {
 709			struct page *p = &page[loop];
 
 710
 711			if (loop + 1 < BITS_PER_LONG)
 712				prefetchw(p + 1);
 713			__ClearPageReserved(p);
 714			set_page_count(p, 0);
 715		}
 
 716
 717		set_page_refcounted(page);
 718		__free_pages(page, order);
 719	}
 720}
 721
 
 
 
 
 
 
 722
 723/*
 724 * The order of subdivision here is critical for the IO subsystem.
 725 * Please do not alter this order without good reasons and regression
 726 * testing. Specifically, as large blocks of memory are subdivided,
 727 * the order in which smaller blocks are delivered depends on the order
 728 * they're subdivided in this function. This is the primary factor
 729 * influencing the order in which pages are delivered to the IO
 730 * subsystem according to empirical testing, and this is also justified
 731 * by considering the behavior of a buddy system containing a single
 732 * large block of memory acted on by a series of small allocations.
 733 * This behavior is a critical factor in sglist merging's success.
 734 *
 735 * -- wli
 736 */
 737static inline void expand(struct zone *zone, struct page *page,
 738	int low, int high, struct free_area *area,
 739	int migratetype)
 740{
 741	unsigned long size = 1 << high;
 742
 743	while (high > low) {
 744		area--;
 745		high--;
 746		size >>= 1;
 747		VM_BUG_ON(bad_range(zone, &page[size]));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 748		list_add(&page[size].lru, &area->free_list[migratetype]);
 749		area->nr_free++;
 750		set_page_order(&page[size], high);
 751	}
 752}
 753
 754/*
 755 * This page is about to be returned from the page allocator
 756 */
 757static inline int check_new_page(struct page *page)
 758{
 759	if (unlikely(page_mapcount(page) |
 760		(page->mapping != NULL)  |
 761		(atomic_read(&page->_count) != 0)  |
 762		(page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
 763		(mem_cgroup_bad_page_check(page)))) {
 764		bad_page(page);
 
 
 
 
 
 
 
 
 
 
 
 765		return 1;
 766	}
 767	return 0;
 768}
 769
 770static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
 771{
 772	int i;
 773
 774	for (i = 0; i < (1 << order); i++) {
 775		struct page *p = page + i;
 776		if (unlikely(check_new_page(p)))
 777			return 1;
 778	}
 779
 780	set_page_private(page, 0);
 781	set_page_refcounted(page);
 782
 783	arch_alloc_page(page, order);
 784	kernel_map_pages(page, 1 << order, 1);
 785
 786	if (gfp_flags & __GFP_ZERO)
 787		prep_zero_page(page, order, gfp_flags);
 788
 789	if (order && (gfp_flags & __GFP_COMP))
 790		prep_compound_page(page, order);
 791
 792	return 0;
 793}
 794
 795/*
 796 * Go through the free lists for the given migratetype and remove
 797 * the smallest available page from the freelists
 798 */
 799static inline
 800struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
 801						int migratetype)
 802{
 803	unsigned int current_order;
 804	struct free_area * area;
 805	struct page *page;
 806
 807	/* Find a page of the appropriate size in the preferred list */
 808	for (current_order = order; current_order < MAX_ORDER; ++current_order) {
 809		area = &(zone->free_area[current_order]);
 810		if (list_empty(&area->free_list[migratetype]))
 811			continue;
 812
 813		page = list_entry(area->free_list[migratetype].next,
 814							struct page, lru);
 815		list_del(&page->lru);
 816		rmv_page_order(page);
 817		area->nr_free--;
 818		expand(zone, page, order, current_order, area, migratetype);
 819		return page;
 820	}
 821
 822	return NULL;
 823}
 824
 825
 826/*
 827 * This array describes the order lists are fallen back to when
 828 * the free lists for the desirable migrate type are depleted
 829 */
 830static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
 831	[MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_RESERVE },
 832	[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_RESERVE },
 833	[MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
 834	[MIGRATE_RESERVE]     = { MIGRATE_RESERVE,     MIGRATE_RESERVE,   MIGRATE_RESERVE }, /* Never used */
 
 
 
 
 
 
 
 
 835};
 836
 837/*
 838 * Move the free pages in a range to the free lists of the requested type.
 839 * Note that start_page and end_pages are not aligned on a pageblock
 840 * boundary. If alignment is required, use move_freepages_block()
 841 */
 842static int move_freepages(struct zone *zone,
 843			  struct page *start_page, struct page *end_page,
 844			  int migratetype)
 845{
 846	struct page *page;
 847	unsigned long order;
 848	int pages_moved = 0;
 849
 850#ifndef CONFIG_HOLES_IN_ZONE
 851	/*
 852	 * page_zone is not safe to call in this context when
 853	 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
 854	 * anyway as we check zone boundaries in move_freepages_block().
 855	 * Remove at a later date when no bug reports exist related to
 856	 * grouping pages by mobility
 857	 */
 858	BUG_ON(page_zone(start_page) != page_zone(end_page));
 859#endif
 860
 861	for (page = start_page; page <= end_page;) {
 862		/* Make sure we are not inadvertently changing nodes */
 863		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
 864
 865		if (!pfn_valid_within(page_to_pfn(page))) {
 866			page++;
 867			continue;
 868		}
 869
 870		if (!PageBuddy(page)) {
 871			page++;
 872			continue;
 873		}
 874
 875		order = page_order(page);
 876		list_move(&page->lru,
 877			  &zone->free_area[order].free_list[migratetype]);
 
 878		page += 1 << order;
 879		pages_moved += 1 << order;
 880	}
 881
 882	return pages_moved;
 883}
 884
 885static int move_freepages_block(struct zone *zone, struct page *page,
 886				int migratetype)
 887{
 888	unsigned long start_pfn, end_pfn;
 889	struct page *start_page, *end_page;
 890
 891	start_pfn = page_to_pfn(page);
 892	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
 893	start_page = pfn_to_page(start_pfn);
 894	end_page = start_page + pageblock_nr_pages - 1;
 895	end_pfn = start_pfn + pageblock_nr_pages - 1;
 896
 897	/* Do not cross zone boundaries */
 898	if (start_pfn < zone->zone_start_pfn)
 899		start_page = page;
 900	if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
 901		return 0;
 902
 903	return move_freepages(zone, start_page, end_page, migratetype);
 904}
 905
 906static void change_pageblock_range(struct page *pageblock_page,
 907					int start_order, int migratetype)
 908{
 909	int nr_pageblocks = 1 << (start_order - pageblock_order);
 910
 911	while (nr_pageblocks--) {
 912		set_pageblock_migratetype(pageblock_page, migratetype);
 913		pageblock_page += pageblock_nr_pages;
 914	}
 915}
 916
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 917/* Remove an element from the buddy allocator from the fallback list */
 918static inline struct page *
 919__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
 920{
 921	struct free_area * area;
 922	int current_order;
 923	struct page *page;
 924	int migratetype, i;
 925
 926	/* Find the largest possible block of pages in the other list */
 927	for (current_order = MAX_ORDER-1; current_order >= order;
 928						--current_order) {
 929		for (i = 0; i < MIGRATE_TYPES - 1; i++) {
 930			migratetype = fallbacks[start_migratetype][i];
 931
 932			/* MIGRATE_RESERVE handled later if necessary */
 933			if (migratetype == MIGRATE_RESERVE)
 934				continue;
 935
 936			area = &(zone->free_area[current_order]);
 937			if (list_empty(&area->free_list[migratetype]))
 938				continue;
 939
 940			page = list_entry(area->free_list[migratetype].next,
 941					struct page, lru);
 942			area->nr_free--;
 943
 944			/*
 945			 * If breaking a large block of pages, move all free
 946			 * pages to the preferred allocation list. If falling
 947			 * back for a reclaimable kernel allocation, be more
 948			 * aggressive about taking ownership of free pages
 949			 */
 950			if (unlikely(current_order >= (pageblock_order >> 1)) ||
 951					start_migratetype == MIGRATE_RECLAIMABLE ||
 952					page_group_by_mobility_disabled) {
 953				unsigned long pages;
 954				pages = move_freepages_block(zone, page,
 955								start_migratetype);
 956
 957				/* Claim the whole block if over half of it is free */
 958				if (pages >= (1 << (pageblock_order-1)) ||
 959						page_group_by_mobility_disabled)
 960					set_pageblock_migratetype(page,
 961								start_migratetype);
 962
 963				migratetype = start_migratetype;
 964			}
 965
 966			/* Remove the page from the freelists */
 967			list_del(&page->lru);
 968			rmv_page_order(page);
 969
 970			/* Take ownership for orders >= pageblock_order */
 971			if (current_order >= pageblock_order)
 972				change_pageblock_range(page, current_order,
 973							start_migratetype);
 974
 975			expand(zone, page, order, current_order, area, migratetype);
 976
 977			trace_mm_page_alloc_extfrag(page, order, current_order,
 978				start_migratetype, migratetype);
 979
 980			return page;
 981		}
 982	}
 983
 984	return NULL;
 985}
 986
 987/*
 988 * Do the hard work of removing an element from the buddy allocator.
 989 * Call me with the zone->lock already held.
 990 */
 991static struct page *__rmqueue(struct zone *zone, unsigned int order,
 992						int migratetype)
 993{
 994	struct page *page;
 995
 996retry_reserve:
 997	page = __rmqueue_smallest(zone, order, migratetype);
 998
 999	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1000		page = __rmqueue_fallback(zone, order, migratetype);
1001
1002		/*
1003		 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1004		 * is used because __rmqueue_smallest is an inline function
1005		 * and we want just one call site
1006		 */
1007		if (!page) {
1008			migratetype = MIGRATE_RESERVE;
1009			goto retry_reserve;
1010		}
1011	}
1012
1013	trace_mm_page_alloc_zone_locked(page, order, migratetype);
1014	return page;
1015}
1016
1017/* 
1018 * Obtain a specified number of elements from the buddy allocator, all under
1019 * a single hold of the lock, for efficiency.  Add them to the supplied list.
1020 * Returns the number of new pages which were placed at *list.
1021 */
1022static int rmqueue_bulk(struct zone *zone, unsigned int order, 
1023			unsigned long count, struct list_head *list,
1024			int migratetype, int cold)
1025{
1026	int i;
1027	
1028	spin_lock(&zone->lock);
1029	for (i = 0; i < count; ++i) {
1030		struct page *page = __rmqueue(zone, order, migratetype);
1031		if (unlikely(page == NULL))
1032			break;
1033
1034		/*
1035		 * Split buddy pages returned by expand() are received here
1036		 * in physical page order. The page is added to the callers and
1037		 * list and the list head then moves forward. From the callers
1038		 * perspective, the linked list is ordered by page number in
1039		 * some conditions. This is useful for IO devices that can
1040		 * merge IO requests if the physical pages are ordered
1041		 * properly.
1042		 */
1043		if (likely(cold == 0))
1044			list_add(&page->lru, list);
1045		else
1046			list_add_tail(&page->lru, list);
1047		set_page_private(page, migratetype);
 
 
 
 
 
1048		list = &page->lru;
 
 
 
1049	}
1050	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1051	spin_unlock(&zone->lock);
1052	return i;
1053}
1054
1055#ifdef CONFIG_NUMA
1056/*
1057 * Called from the vmstat counter updater to drain pagesets of this
1058 * currently executing processor on remote nodes after they have
1059 * expired.
1060 *
1061 * Note that this function must be called with the thread pinned to
1062 * a single processor.
1063 */
1064void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1065{
1066	unsigned long flags;
1067	int to_drain;
 
1068
1069	local_irq_save(flags);
1070	if (pcp->count >= pcp->batch)
1071		to_drain = pcp->batch;
 
1072	else
1073		to_drain = pcp->count;
1074	free_pcppages_bulk(zone, to_drain, pcp);
1075	pcp->count -= to_drain;
 
 
1076	local_irq_restore(flags);
1077}
1078#endif
1079
1080/*
1081 * Drain pages of the indicated processor.
1082 *
1083 * The processor must either be the current processor and the
1084 * thread pinned to the current processor or a processor that
1085 * is not online.
1086 */
1087static void drain_pages(unsigned int cpu)
1088{
1089	unsigned long flags;
1090	struct zone *zone;
1091
1092	for_each_populated_zone(zone) {
1093		struct per_cpu_pageset *pset;
1094		struct per_cpu_pages *pcp;
1095
1096		local_irq_save(flags);
1097		pset = per_cpu_ptr(zone->pageset, cpu);
1098
1099		pcp = &pset->pcp;
1100		if (pcp->count) {
1101			free_pcppages_bulk(zone, pcp->count, pcp);
1102			pcp->count = 0;
1103		}
1104		local_irq_restore(flags);
1105	}
1106}
1107
1108/*
1109 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1110 */
1111void drain_local_pages(void *arg)
1112{
1113	drain_pages(smp_processor_id());
1114}
1115
1116/*
1117 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
 
 
 
 
 
 
1118 */
1119void drain_all_pages(void)
1120{
1121	on_each_cpu(drain_local_pages, NULL, 1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1122}
1123
1124#ifdef CONFIG_HIBERNATION
1125
1126void mark_free_pages(struct zone *zone)
1127{
1128	unsigned long pfn, max_zone_pfn;
1129	unsigned long flags;
1130	int order, t;
1131	struct list_head *curr;
1132
1133	if (!zone->spanned_pages)
1134		return;
1135
1136	spin_lock_irqsave(&zone->lock, flags);
1137
1138	max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1139	for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1140		if (pfn_valid(pfn)) {
1141			struct page *page = pfn_to_page(pfn);
1142
1143			if (!swsusp_page_is_forbidden(page))
1144				swsusp_unset_page_free(page);
1145		}
1146
1147	for_each_migratetype_order(order, t) {
1148		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1149			unsigned long i;
1150
1151			pfn = page_to_pfn(list_entry(curr, struct page, lru));
1152			for (i = 0; i < (1UL << order); i++)
1153				swsusp_set_page_free(pfn_to_page(pfn + i));
1154		}
1155	}
1156	spin_unlock_irqrestore(&zone->lock, flags);
1157}
1158#endif /* CONFIG_PM */
1159
1160/*
1161 * Free a 0-order page
1162 * cold == 1 ? free a cold page : free a hot page
1163 */
1164void free_hot_cold_page(struct page *page, int cold)
1165{
1166	struct zone *zone = page_zone(page);
1167	struct per_cpu_pages *pcp;
1168	unsigned long flags;
1169	int migratetype;
1170	int wasMlocked = __TestClearPageMlocked(page);
1171
1172	if (!free_pages_prepare(page, 0))
1173		return;
1174
1175	migratetype = get_pageblock_migratetype(page);
1176	set_page_private(page, migratetype);
1177	local_irq_save(flags);
1178	if (unlikely(wasMlocked))
1179		free_page_mlock(page);
1180	__count_vm_event(PGFREE);
1181
1182	/*
1183	 * We only track unmovable, reclaimable and movable on pcp lists.
1184	 * Free ISOLATE pages back to the allocator because they are being
1185	 * offlined but treat RESERVE as movable pages so we can get those
1186	 * areas back if necessary. Otherwise, we may have to free
1187	 * excessively into the page allocator
1188	 */
1189	if (migratetype >= MIGRATE_PCPTYPES) {
1190		if (unlikely(migratetype == MIGRATE_ISOLATE)) {
1191			free_one_page(zone, page, 0, migratetype);
1192			goto out;
1193		}
1194		migratetype = MIGRATE_MOVABLE;
1195	}
1196
1197	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1198	if (cold)
1199		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1200	else
1201		list_add(&page->lru, &pcp->lists[migratetype]);
1202	pcp->count++;
1203	if (pcp->count >= pcp->high) {
1204		free_pcppages_bulk(zone, pcp->batch, pcp);
1205		pcp->count -= pcp->batch;
 
1206	}
1207
1208out:
1209	local_irq_restore(flags);
1210}
1211
1212/*
 
 
 
 
 
 
 
 
 
 
 
 
 
1213 * split_page takes a non-compound higher-order page, and splits it into
1214 * n (1<<order) sub-pages: page[0..n]
1215 * Each sub-page must be freed individually.
1216 *
1217 * Note: this is probably too low level an operation for use in drivers.
1218 * Please consult with lkml before using this in your driver.
1219 */
1220void split_page(struct page *page, unsigned int order)
1221{
1222	int i;
1223
1224	VM_BUG_ON(PageCompound(page));
1225	VM_BUG_ON(!page_count(page));
1226
1227#ifdef CONFIG_KMEMCHECK
1228	/*
1229	 * Split shadow pages too, because free(page[0]) would
1230	 * otherwise free the whole shadow.
1231	 */
1232	if (kmemcheck_page_is_tracked(page))
1233		split_page(virt_to_page(page[0].shadow), order);
1234#endif
1235
1236	for (i = 1; i < (1 << order); i++)
1237		set_page_refcounted(page + i);
1238}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1239
1240/*
1241 * Similar to split_page except the page is already free. As this is only
1242 * being used for migration, the migratetype of the block also changes.
1243 * As this is called with interrupts disabled, the caller is responsible
1244 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1245 * are enabled.
1246 *
1247 * Note: this is probably too low level an operation for use in drivers.
1248 * Please consult with lkml before using this in your driver.
1249 */
1250int split_free_page(struct page *page)
1251{
1252	unsigned int order;
1253	unsigned long watermark;
1254	struct zone *zone;
1255
1256	BUG_ON(!PageBuddy(page));
1257
1258	zone = page_zone(page);
1259	order = page_order(page);
1260
1261	/* Obey watermarks as if the page was being allocated */
1262	watermark = low_wmark_pages(zone) + (1 << order);
1263	if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1264		return 0;
1265
1266	/* Remove page from free list */
1267	list_del(&page->lru);
1268	zone->free_area[order].nr_free--;
1269	rmv_page_order(page);
1270	__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
1271
1272	/* Split into individual pages */
1273	set_page_refcounted(page);
1274	split_page(page, order);
1275
1276	if (order >= pageblock_order - 1) {
1277		struct page *endpage = page + (1 << order) - 1;
1278		for (; page < endpage; page += pageblock_nr_pages)
1279			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1280	}
1281
1282	return 1 << order;
1283}
1284
1285/*
1286 * Really, prep_compound_page() should be called from __rmqueue_bulk().  But
1287 * we cheat by calling it from here, in the order > 0 path.  Saves a branch
1288 * or two.
1289 */
1290static inline
1291struct page *buffered_rmqueue(struct zone *preferred_zone,
1292			struct zone *zone, int order, gfp_t gfp_flags,
1293			int migratetype)
1294{
1295	unsigned long flags;
1296	struct page *page;
1297	int cold = !!(gfp_flags & __GFP_COLD);
1298
1299again:
1300	if (likely(order == 0)) {
1301		struct per_cpu_pages *pcp;
1302		struct list_head *list;
1303
1304		local_irq_save(flags);
1305		pcp = &this_cpu_ptr(zone->pageset)->pcp;
1306		list = &pcp->lists[migratetype];
1307		if (list_empty(list)) {
1308			pcp->count += rmqueue_bulk(zone, 0,
1309					pcp->batch, list,
1310					migratetype, cold);
1311			if (unlikely(list_empty(list)))
1312				goto failed;
1313		}
1314
1315		if (cold)
1316			page = list_entry(list->prev, struct page, lru);
1317		else
1318			page = list_entry(list->next, struct page, lru);
1319
1320		list_del(&page->lru);
1321		pcp->count--;
1322	} else {
1323		if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1324			/*
1325			 * __GFP_NOFAIL is not to be used in new code.
1326			 *
1327			 * All __GFP_NOFAIL callers should be fixed so that they
1328			 * properly detect and handle allocation failures.
1329			 *
1330			 * We most definitely don't want callers attempting to
1331			 * allocate greater than order-1 page units with
1332			 * __GFP_NOFAIL.
1333			 */
1334			WARN_ON_ONCE(order > 1);
1335		}
1336		spin_lock_irqsave(&zone->lock, flags);
1337		page = __rmqueue(zone, order, migratetype);
1338		spin_unlock(&zone->lock);
1339		if (!page)
1340			goto failed;
1341		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
 
1342	}
1343
 
 
1344	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1345	zone_statistics(preferred_zone, zone, gfp_flags);
1346	local_irq_restore(flags);
1347
1348	VM_BUG_ON(bad_range(zone, page));
1349	if (prep_new_page(page, order, gfp_flags))
1350		goto again;
1351	return page;
1352
1353failed:
1354	local_irq_restore(flags);
1355	return NULL;
1356}
1357
1358/* The ALLOC_WMARK bits are used as an index to zone->watermark */
1359#define ALLOC_WMARK_MIN		WMARK_MIN
1360#define ALLOC_WMARK_LOW		WMARK_LOW
1361#define ALLOC_WMARK_HIGH	WMARK_HIGH
1362#define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
1363
1364/* Mask to get the watermark bits */
1365#define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
1366
1367#define ALLOC_HARDER		0x10 /* try to alloc harder */
1368#define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
1369#define ALLOC_CPUSET		0x40 /* check for correct cpuset */
1370
1371#ifdef CONFIG_FAIL_PAGE_ALLOC
1372
1373static struct {
1374	struct fault_attr attr;
1375
1376	u32 ignore_gfp_highmem;
1377	u32 ignore_gfp_wait;
1378	u32 min_order;
1379} fail_page_alloc = {
1380	.attr = FAULT_ATTR_INITIALIZER,
1381	.ignore_gfp_wait = 1,
1382	.ignore_gfp_highmem = 1,
1383	.min_order = 1,
1384};
1385
1386static int __init setup_fail_page_alloc(char *str)
1387{
1388	return setup_fault_attr(&fail_page_alloc.attr, str);
1389}
1390__setup("fail_page_alloc=", setup_fail_page_alloc);
1391
1392static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1393{
1394	if (order < fail_page_alloc.min_order)
1395		return 0;
1396	if (gfp_mask & __GFP_NOFAIL)
1397		return 0;
1398	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1399		return 0;
1400	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1401		return 0;
1402
1403	return should_fail(&fail_page_alloc.attr, 1 << order);
1404}
1405
1406#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1407
1408static int __init fail_page_alloc_debugfs(void)
1409{
1410	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1411	struct dentry *dir;
1412
1413	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1414					&fail_page_alloc.attr);
1415	if (IS_ERR(dir))
1416		return PTR_ERR(dir);
1417
1418	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1419				&fail_page_alloc.ignore_gfp_wait))
1420		goto fail;
1421	if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1422				&fail_page_alloc.ignore_gfp_highmem))
1423		goto fail;
1424	if (!debugfs_create_u32("min-order", mode, dir,
1425				&fail_page_alloc.min_order))
1426		goto fail;
1427
1428	return 0;
1429fail:
1430	debugfs_remove_recursive(dir);
1431
1432	return -ENOMEM;
1433}
1434
1435late_initcall(fail_page_alloc_debugfs);
1436
1437#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1438
1439#else /* CONFIG_FAIL_PAGE_ALLOC */
1440
1441static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1442{
1443	return 0;
1444}
1445
1446#endif /* CONFIG_FAIL_PAGE_ALLOC */
1447
1448/*
1449 * Return true if free pages are above 'mark'. This takes into account the order
1450 * of the allocation.
1451 */
1452static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1453		      int classzone_idx, int alloc_flags, long free_pages)
1454{
1455	/* free_pages my go negative - that's OK */
1456	long min = mark;
 
1457	int o;
 
1458
1459	free_pages -= (1 << order) + 1;
1460	if (alloc_flags & ALLOC_HIGH)
1461		min -= min / 2;
1462	if (alloc_flags & ALLOC_HARDER)
1463		min -= min / 4;
 
 
 
 
 
1464
1465	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1466		return false;
1467	for (o = 0; o < order; o++) {
1468		/* At the next order, this order's pages become unavailable */
1469		free_pages -= z->free_area[o].nr_free << o;
1470
1471		/* Require fewer higher order pages to be free */
1472		min >>= 1;
1473
1474		if (free_pages <= min)
1475			return false;
1476	}
1477	return true;
1478}
1479
1480bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1481		      int classzone_idx, int alloc_flags)
1482{
1483	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1484					zone_page_state(z, NR_FREE_PAGES));
1485}
1486
1487bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
1488		      int classzone_idx, int alloc_flags)
1489{
1490	long free_pages = zone_page_state(z, NR_FREE_PAGES);
1491
1492	if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1493		free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1494
1495	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1496								free_pages);
1497}
1498
1499#ifdef CONFIG_NUMA
1500/*
1501 * zlc_setup - Setup for "zonelist cache".  Uses cached zone data to
1502 * skip over zones that are not allowed by the cpuset, or that have
1503 * been recently (in last second) found to be nearly full.  See further
1504 * comments in mmzone.h.  Reduces cache footprint of zonelist scans
1505 * that have to skip over a lot of full or unallowed zones.
1506 *
1507 * If the zonelist cache is present in the passed in zonelist, then
1508 * returns a pointer to the allowed node mask (either the current
1509 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1510 *
1511 * If the zonelist cache is not available for this zonelist, does
1512 * nothing and returns NULL.
1513 *
1514 * If the fullzones BITMAP in the zonelist cache is stale (more than
1515 * a second since last zap'd) then we zap it out (clear its bits.)
1516 *
1517 * We hold off even calling zlc_setup, until after we've checked the
1518 * first zone in the zonelist, on the theory that most allocations will
1519 * be satisfied from that first zone, so best to examine that zone as
1520 * quickly as we can.
1521 */
1522static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1523{
1524	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
1525	nodemask_t *allowednodes;	/* zonelist_cache approximation */
1526
1527	zlc = zonelist->zlcache_ptr;
1528	if (!zlc)
1529		return NULL;
1530
1531	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1532		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1533		zlc->last_full_zap = jiffies;
1534	}
1535
1536	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1537					&cpuset_current_mems_allowed :
1538					&node_states[N_HIGH_MEMORY];
1539	return allowednodes;
1540}
1541
1542/*
1543 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1544 * if it is worth looking at further for free memory:
1545 *  1) Check that the zone isn't thought to be full (doesn't have its
1546 *     bit set in the zonelist_cache fullzones BITMAP).
1547 *  2) Check that the zones node (obtained from the zonelist_cache
1548 *     z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1549 * Return true (non-zero) if zone is worth looking at further, or
1550 * else return false (zero) if it is not.
1551 *
1552 * This check -ignores- the distinction between various watermarks,
1553 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ...  If a zone is
1554 * found to be full for any variation of these watermarks, it will
1555 * be considered full for up to one second by all requests, unless
1556 * we are so low on memory on all allowed nodes that we are forced
1557 * into the second scan of the zonelist.
1558 *
1559 * In the second scan we ignore this zonelist cache and exactly
1560 * apply the watermarks to all zones, even it is slower to do so.
1561 * We are low on memory in the second scan, and should leave no stone
1562 * unturned looking for a free page.
1563 */
1564static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1565						nodemask_t *allowednodes)
1566{
1567	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
1568	int i;				/* index of *z in zonelist zones */
1569	int n;				/* node that zone *z is on */
1570
1571	zlc = zonelist->zlcache_ptr;
1572	if (!zlc)
1573		return 1;
1574
1575	i = z - zonelist->_zonerefs;
1576	n = zlc->z_to_n[i];
1577
1578	/* This zone is worth trying if it is allowed but not full */
1579	return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1580}
1581
1582/*
1583 * Given 'z' scanning a zonelist, set the corresponding bit in
1584 * zlc->fullzones, so that subsequent attempts to allocate a page
1585 * from that zone don't waste time re-examining it.
1586 */
1587static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1588{
1589	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
1590	int i;				/* index of *z in zonelist zones */
1591
1592	zlc = zonelist->zlcache_ptr;
1593	if (!zlc)
1594		return;
1595
1596	i = z - zonelist->_zonerefs;
1597
1598	set_bit(i, zlc->fullzones);
1599}
1600
1601/*
1602 * clear all zones full, called after direct reclaim makes progress so that
1603 * a zone that was recently full is not skipped over for up to a second
1604 */
1605static void zlc_clear_zones_full(struct zonelist *zonelist)
1606{
1607	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
1608
1609	zlc = zonelist->zlcache_ptr;
1610	if (!zlc)
1611		return;
1612
1613	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1614}
1615
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1616#else	/* CONFIG_NUMA */
1617
1618static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1619{
1620	return NULL;
1621}
1622
1623static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1624				nodemask_t *allowednodes)
1625{
1626	return 1;
1627}
1628
1629static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1630{
1631}
1632
1633static void zlc_clear_zones_full(struct zonelist *zonelist)
1634{
1635}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1636#endif	/* CONFIG_NUMA */
1637
1638/*
1639 * get_page_from_freelist goes through the zonelist trying to allocate
1640 * a page.
1641 */
1642static struct page *
1643get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1644		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1645		struct zone *preferred_zone, int migratetype)
1646{
1647	struct zoneref *z;
1648	struct page *page = NULL;
1649	int classzone_idx;
1650	struct zone *zone;
1651	nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1652	int zlc_active = 0;		/* set if using zonelist_cache */
1653	int did_zlc_setup = 0;		/* just call zlc_setup() one time */
1654
1655	classzone_idx = zone_idx(preferred_zone);
1656zonelist_scan:
1657	/*
1658	 * Scan zonelist, looking for a zone with enough free.
1659	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1660	 */
1661	for_each_zone_zonelist_nodemask(zone, z, zonelist,
1662						high_zoneidx, nodemask) {
1663		if (NUMA_BUILD && zlc_active &&
 
 
1664			!zlc_zone_worth_trying(zonelist, z, allowednodes))
1665				continue;
1666		if ((alloc_flags & ALLOC_CPUSET) &&
1667			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1668				continue;
1669
1670		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1671		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1672			unsigned long mark;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1673			int ret;
1674
1675			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1676			if (zone_watermark_ok(zone, order, mark,
1677				    classzone_idx, alloc_flags))
1678				goto try_this_zone;
1679
1680			if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1681				/*
1682				 * we do zlc_setup if there are multiple nodes
1683				 * and before considering the first zone allowed
1684				 * by the cpuset.
1685				 */
1686				allowednodes = zlc_setup(zonelist, alloc_flags);
1687				zlc_active = 1;
1688				did_zlc_setup = 1;
1689			}
1690
1691			if (zone_reclaim_mode == 0)
 
1692				goto this_zone_full;
1693
1694			/*
1695			 * As we may have just activated ZLC, check if the first
1696			 * eligible zone has failed zone_reclaim recently.
1697			 */
1698			if (NUMA_BUILD && zlc_active &&
1699				!zlc_zone_worth_trying(zonelist, z, allowednodes))
1700				continue;
1701
1702			ret = zone_reclaim(zone, gfp_mask, order);
1703			switch (ret) {
1704			case ZONE_RECLAIM_NOSCAN:
1705				/* did not scan */
1706				continue;
1707			case ZONE_RECLAIM_FULL:
1708				/* scanned but unreclaimable */
1709				continue;
1710			default:
1711				/* did we reclaim enough */
1712				if (!zone_watermark_ok(zone, order, mark,
1713						classzone_idx, alloc_flags))
 
 
 
 
 
 
 
 
 
 
 
 
 
1714					goto this_zone_full;
 
 
1715			}
1716		}
1717
1718try_this_zone:
1719		page = buffered_rmqueue(preferred_zone, zone, order,
1720						gfp_mask, migratetype);
1721		if (page)
1722			break;
1723this_zone_full:
1724		if (NUMA_BUILD)
1725			zlc_mark_zone_full(zonelist, z);
1726	}
1727
1728	if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1729		/* Disable zlc cache for second zonelist scan */
1730		zlc_active = 0;
1731		goto zonelist_scan;
1732	}
 
 
 
 
 
 
 
 
 
 
 
1733	return page;
1734}
1735
1736/*
1737 * Large machines with many possible nodes should not always dump per-node
1738 * meminfo in irq context.
1739 */
1740static inline bool should_suppress_show_mem(void)
1741{
1742	bool ret = false;
1743
1744#if NODES_SHIFT > 8
1745	ret = in_interrupt();
1746#endif
1747	return ret;
1748}
1749
1750static DEFINE_RATELIMIT_STATE(nopage_rs,
1751		DEFAULT_RATELIMIT_INTERVAL,
1752		DEFAULT_RATELIMIT_BURST);
1753
1754void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
1755{
1756	va_list args;
1757	unsigned int filter = SHOW_MEM_FILTER_NODES;
1758
1759	if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
 
1760		return;
1761
1762	/*
1763	 * This documents exceptions given to allocations in certain
1764	 * contexts that are allowed to allocate outside current's set
1765	 * of allowed nodes.
1766	 */
1767	if (!(gfp_mask & __GFP_NOMEMALLOC))
1768		if (test_thread_flag(TIF_MEMDIE) ||
1769		    (current->flags & (PF_MEMALLOC | PF_EXITING)))
1770			filter &= ~SHOW_MEM_FILTER_NODES;
1771	if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
1772		filter &= ~SHOW_MEM_FILTER_NODES;
1773
1774	if (fmt) {
1775		printk(KERN_WARNING);
 
 
1776		va_start(args, fmt);
1777		vprintk(fmt, args);
 
 
 
 
 
1778		va_end(args);
1779	}
1780
1781	pr_warning("%s: page allocation failure: order:%d, mode:0x%x\n",
1782		   current->comm, order, gfp_mask);
1783
1784	dump_stack();
1785	if (!should_suppress_show_mem())
1786		show_mem(filter);
1787}
1788
1789static inline int
1790should_alloc_retry(gfp_t gfp_mask, unsigned int order,
 
1791				unsigned long pages_reclaimed)
1792{
1793	/* Do not loop if specifically requested */
1794	if (gfp_mask & __GFP_NORETRY)
1795		return 0;
1796
 
 
 
 
 
 
 
 
 
 
 
 
1797	/*
1798	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1799	 * means __GFP_NOFAIL, but that may not be true in other
1800	 * implementations.
1801	 */
1802	if (order <= PAGE_ALLOC_COSTLY_ORDER)
1803		return 1;
1804
1805	/*
1806	 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1807	 * specified, then we retry until we no longer reclaim any pages
1808	 * (above), or we've reclaimed an order of pages at least as
1809	 * large as the allocation's order. In both cases, if the
1810	 * allocation still fails, we stop retrying.
1811	 */
1812	if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
1813		return 1;
1814
1815	/*
1816	 * Don't let big-order allocations loop unless the caller
1817	 * explicitly requests that.
1818	 */
1819	if (gfp_mask & __GFP_NOFAIL)
1820		return 1;
1821
1822	return 0;
1823}
1824
1825static inline struct page *
1826__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
1827	struct zonelist *zonelist, enum zone_type high_zoneidx,
1828	nodemask_t *nodemask, struct zone *preferred_zone,
1829	int migratetype)
1830{
1831	struct page *page;
1832
1833	/* Acquire the OOM killer lock for the zones in zonelist */
1834	if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
1835		schedule_timeout_uninterruptible(1);
1836		return NULL;
1837	}
1838
1839	/*
1840	 * Go through the zonelist yet one more time, keep very high watermark
1841	 * here, this is only to catch a parallel oom killing, we must fail if
1842	 * we're still under heavy pressure.
1843	 */
1844	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
1845		order, zonelist, high_zoneidx,
1846		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1847		preferred_zone, migratetype);
1848	if (page)
1849		goto out;
1850
1851	if (!(gfp_mask & __GFP_NOFAIL)) {
1852		/* The OOM killer will not help higher order allocs */
1853		if (order > PAGE_ALLOC_COSTLY_ORDER)
1854			goto out;
1855		/* The OOM killer does not needlessly kill tasks for lowmem */
1856		if (high_zoneidx < ZONE_NORMAL)
1857			goto out;
1858		/*
1859		 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1860		 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1861		 * The caller should handle page allocation failure by itself if
1862		 * it specifies __GFP_THISNODE.
1863		 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1864		 */
1865		if (gfp_mask & __GFP_THISNODE)
1866			goto out;
1867	}
1868	/* Exhausted what can be done so it's blamo time */
1869	out_of_memory(zonelist, gfp_mask, order, nodemask);
1870
1871out:
1872	clear_zonelist_oom(zonelist, gfp_mask);
1873	return page;
1874}
1875
1876#ifdef CONFIG_COMPACTION
1877/* Try memory compaction for high-order allocations before reclaim */
1878static struct page *
1879__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
1880	struct zonelist *zonelist, enum zone_type high_zoneidx,
1881	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1882	int migratetype, unsigned long *did_some_progress,
1883	bool sync_migration)
 
1884{
1885	struct page *page;
 
1886
1887	if (!order || compaction_deferred(preferred_zone))
 
1888		return NULL;
 
1889
1890	current->flags |= PF_MEMALLOC;
1891	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
1892						nodemask, sync_migration);
 
1893	current->flags &= ~PF_MEMALLOC;
 
1894	if (*did_some_progress != COMPACT_SKIPPED) {
 
1895
1896		/* Page migration frees to the PCP lists but we want merging */
1897		drain_pages(get_cpu());
1898		put_cpu();
1899
1900		page = get_page_from_freelist(gfp_mask, nodemask,
1901				order, zonelist, high_zoneidx,
1902				alloc_flags, preferred_zone,
1903				migratetype);
1904		if (page) {
1905			preferred_zone->compact_considered = 0;
1906			preferred_zone->compact_defer_shift = 0;
1907			count_vm_event(COMPACTSUCCESS);
1908			return page;
1909		}
1910
1911		/*
1912		 * It's bad if compaction run occurs and fails.
1913		 * The most likely reason is that pages exist,
1914		 * but not enough to satisfy watermarks.
1915		 */
1916		count_vm_event(COMPACTFAIL);
1917		defer_compaction(preferred_zone);
 
 
 
 
 
 
1918
1919		cond_resched();
1920	}
1921
1922	return NULL;
1923}
1924#else
1925static inline struct page *
1926__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
1927	struct zonelist *zonelist, enum zone_type high_zoneidx,
1928	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1929	int migratetype, unsigned long *did_some_progress,
1930	bool sync_migration)
 
1931{
1932	return NULL;
1933}
1934#endif /* CONFIG_COMPACTION */
1935
1936/* The really slow allocator path where we enter direct reclaim */
1937static inline struct page *
1938__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
1939	struct zonelist *zonelist, enum zone_type high_zoneidx,
1940	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1941	int migratetype, unsigned long *did_some_progress)
1942{
1943	struct page *page = NULL;
1944	struct reclaim_state reclaim_state;
1945	bool drained = false;
1946
1947	cond_resched();
1948
1949	/* We now go into synchronous reclaim */
1950	cpuset_memory_pressure_bump();
1951	current->flags |= PF_MEMALLOC;
1952	lockdep_set_current_reclaim_state(gfp_mask);
1953	reclaim_state.reclaimed_slab = 0;
1954	current->reclaim_state = &reclaim_state;
1955
1956	*did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
1957
1958	current->reclaim_state = NULL;
1959	lockdep_clear_current_reclaim_state();
1960	current->flags &= ~PF_MEMALLOC;
1961
1962	cond_resched();
1963
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1964	if (unlikely(!(*did_some_progress)))
1965		return NULL;
1966
1967	/* After successful reclaim, reconsider all zones for allocation */
1968	if (NUMA_BUILD)
1969		zlc_clear_zones_full(zonelist);
1970
1971retry:
1972	page = get_page_from_freelist(gfp_mask, nodemask, order,
1973					zonelist, high_zoneidx,
1974					alloc_flags, preferred_zone,
1975					migratetype);
1976
1977	/*
1978	 * If an allocation failed after direct reclaim, it could be because
1979	 * pages are pinned on the per-cpu lists. Drain them and try again
1980	 */
1981	if (!page && !drained) {
1982		drain_all_pages();
1983		drained = true;
1984		goto retry;
1985	}
1986
1987	return page;
1988}
1989
1990/*
1991 * This is called in the allocator slow-path if the allocation request is of
1992 * sufficient urgency to ignore watermarks and take other desperate measures
1993 */
1994static inline struct page *
1995__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
1996	struct zonelist *zonelist, enum zone_type high_zoneidx,
1997	nodemask_t *nodemask, struct zone *preferred_zone,
1998	int migratetype)
1999{
2000	struct page *page;
2001
2002	do {
2003		page = get_page_from_freelist(gfp_mask, nodemask, order,
2004			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2005			preferred_zone, migratetype);
2006
2007		if (!page && gfp_mask & __GFP_NOFAIL)
2008			wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2009	} while (!page && (gfp_mask & __GFP_NOFAIL));
2010
2011	return page;
2012}
2013
2014static inline
2015void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2016						enum zone_type high_zoneidx,
2017						enum zone_type classzone_idx)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2018{
2019	struct zoneref *z;
2020	struct zone *zone;
2021
2022	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2023		wakeup_kswapd(zone, order, classzone_idx);
2024}
2025
2026static inline int
2027gfp_to_alloc_flags(gfp_t gfp_mask)
2028{
2029	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2030	const gfp_t wait = gfp_mask & __GFP_WAIT;
2031
2032	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2033	BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2034
2035	/*
2036	 * The caller may dip into page reserves a bit more if the caller
2037	 * cannot run direct reclaim, or if the caller has realtime scheduling
2038	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
2039	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2040	 */
2041	alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2042
2043	if (!wait) {
2044		/*
2045		 * Not worth trying to allocate harder for
2046		 * __GFP_NOMEMALLOC even if it can't schedule.
2047		 */
2048		if  (!(gfp_mask & __GFP_NOMEMALLOC))
2049			alloc_flags |= ALLOC_HARDER;
2050		/*
2051		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2052		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2053		 */
2054		alloc_flags &= ~ALLOC_CPUSET;
2055	} else if (unlikely(rt_task(current)) && !in_interrupt())
2056		alloc_flags |= ALLOC_HARDER;
2057
2058	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2059		if (!in_interrupt() &&
2060		    ((current->flags & PF_MEMALLOC) ||
2061		     unlikely(test_thread_flag(TIF_MEMDIE))))
 
 
 
 
2062			alloc_flags |= ALLOC_NO_WATERMARKS;
2063	}
2064
 
 
 
2065	return alloc_flags;
2066}
2067
 
 
 
 
 
2068static inline struct page *
2069__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2070	struct zonelist *zonelist, enum zone_type high_zoneidx,
2071	nodemask_t *nodemask, struct zone *preferred_zone,
2072	int migratetype)
2073{
2074	const gfp_t wait = gfp_mask & __GFP_WAIT;
2075	struct page *page = NULL;
2076	int alloc_flags;
2077	unsigned long pages_reclaimed = 0;
2078	unsigned long did_some_progress;
2079	bool sync_migration = false;
 
 
2080
2081	/*
2082	 * In the slowpath, we sanity check order to avoid ever trying to
2083	 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2084	 * be using allocators in order of preference for an area that is
2085	 * too large.
2086	 */
2087	if (order >= MAX_ORDER) {
2088		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2089		return NULL;
2090	}
2091
2092	/*
2093	 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2094	 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2095	 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2096	 * using a larger set of nodes after it has established that the
2097	 * allowed per node queues are empty and that nodes are
2098	 * over allocated.
2099	 */
2100	if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
 
2101		goto nopage;
2102
2103restart:
2104	if (!(gfp_mask & __GFP_NO_KSWAPD))
2105		wake_all_kswapd(order, zonelist, high_zoneidx,
2106						zone_idx(preferred_zone));
2107
2108	/*
2109	 * OK, we're below the kswapd watermark and have kicked background
2110	 * reclaim. Now things get more complex, so set up alloc_flags according
2111	 * to how we want to proceed.
2112	 */
2113	alloc_flags = gfp_to_alloc_flags(gfp_mask);
2114
2115	/*
2116	 * Find the true preferred zone if the allocation is unconstrained by
2117	 * cpusets.
2118	 */
2119	if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
2120		first_zones_zonelist(zonelist, high_zoneidx, NULL,
2121					&preferred_zone);
2122
2123rebalance:
2124	/* This is the last chance, in general, before the goto nopage. */
2125	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2126			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2127			preferred_zone, migratetype);
2128	if (page)
2129		goto got_pg;
2130
2131	/* Allocate without watermarks if the context allows */
2132	if (alloc_flags & ALLOC_NO_WATERMARKS) {
 
 
 
 
 
 
 
2133		page = __alloc_pages_high_priority(gfp_mask, order,
2134				zonelist, high_zoneidx, nodemask,
2135				preferred_zone, migratetype);
2136		if (page)
2137			goto got_pg;
 
2138	}
2139
2140	/* Atomic allocations - we can't balance anything */
2141	if (!wait)
 
 
 
 
 
 
2142		goto nopage;
 
2143
2144	/* Avoid recursion of direct reclaim */
2145	if (current->flags & PF_MEMALLOC)
2146		goto nopage;
2147
2148	/* Avoid allocations with no watermarks from looping endlessly */
2149	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2150		goto nopage;
2151
2152	/*
2153	 * Try direct compaction. The first pass is asynchronous. Subsequent
2154	 * attempts after direct reclaim are synchronous
2155	 */
2156	page = __alloc_pages_direct_compact(gfp_mask, order,
2157					zonelist, high_zoneidx,
2158					nodemask,
2159					alloc_flags, preferred_zone,
2160					migratetype, &did_some_progress,
2161					sync_migration);
 
 
2162	if (page)
2163		goto got_pg;
2164	sync_migration = true;
2165
 
 
 
 
 
 
 
 
 
 
2166	/* Try direct reclaim and then allocating */
2167	page = __alloc_pages_direct_reclaim(gfp_mask, order,
2168					zonelist, high_zoneidx,
2169					nodemask,
2170					alloc_flags, preferred_zone,
2171					migratetype, &did_some_progress);
2172	if (page)
2173		goto got_pg;
2174
2175	/*
2176	 * If we failed to make any progress reclaiming, then we are
2177	 * running out of options and have to consider going OOM
2178	 */
2179	if (!did_some_progress) {
2180		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2181			if (oom_killer_disabled)
2182				goto nopage;
 
 
 
 
2183			page = __alloc_pages_may_oom(gfp_mask, order,
2184					zonelist, high_zoneidx,
2185					nodemask, preferred_zone,
2186					migratetype);
2187			if (page)
2188				goto got_pg;
2189
2190			if (!(gfp_mask & __GFP_NOFAIL)) {
2191				/*
2192				 * The oom killer is not called for high-order
2193				 * allocations that may fail, so if no progress
2194				 * is being made, there are no other options and
2195				 * retrying is unlikely to help.
2196				 */
2197				if (order > PAGE_ALLOC_COSTLY_ORDER)
2198					goto nopage;
2199				/*
2200				 * The oom killer is not called for lowmem
2201				 * allocations to prevent needlessly killing
2202				 * innocent tasks.
2203				 */
2204				if (high_zoneidx < ZONE_NORMAL)
2205					goto nopage;
2206			}
2207
2208			goto restart;
2209		}
2210	}
2211
2212	/* Check if we should retry the allocation */
2213	pages_reclaimed += did_some_progress;
2214	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
 
2215		/* Wait for some write requests to complete then retry */
2216		wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2217		goto rebalance;
2218	} else {
2219		/*
2220		 * High-order allocations do not necessarily loop after
2221		 * direct reclaim and reclaim/compaction depends on compaction
2222		 * being called after reclaim so call directly if necessary
2223		 */
2224		page = __alloc_pages_direct_compact(gfp_mask, order,
2225					zonelist, high_zoneidx,
2226					nodemask,
2227					alloc_flags, preferred_zone,
2228					migratetype, &did_some_progress,
2229					sync_migration);
 
 
2230		if (page)
2231			goto got_pg;
2232	}
2233
2234nopage:
2235	warn_alloc_failed(gfp_mask, order, NULL);
2236	return page;
2237got_pg:
2238	if (kmemcheck_enabled)
2239		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2240	return page;
2241
 
2242}
2243
2244/*
2245 * This is the 'heart' of the zoned buddy allocator.
2246 */
2247struct page *
2248__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2249			struct zonelist *zonelist, nodemask_t *nodemask)
2250{
2251	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2252	struct zone *preferred_zone;
2253	struct page *page;
2254	int migratetype = allocflags_to_migratetype(gfp_mask);
 
 
 
2255
2256	gfp_mask &= gfp_allowed_mask;
2257
2258	lockdep_trace_alloc(gfp_mask);
2259
2260	might_sleep_if(gfp_mask & __GFP_WAIT);
2261
2262	if (should_fail_alloc_page(gfp_mask, order))
2263		return NULL;
2264
2265	/*
2266	 * Check the zones suitable for the gfp_mask contain at least one
2267	 * valid zone. It's possible to have an empty zonelist as a result
2268	 * of GFP_THISNODE and a memoryless node
2269	 */
2270	if (unlikely(!zonelist->_zonerefs->zone))
2271		return NULL;
2272
2273	get_mems_allowed();
 
 
 
 
 
 
 
 
 
2274	/* The preferred zone is used for statistics later */
2275	first_zones_zonelist(zonelist, high_zoneidx,
2276				nodemask ? : &cpuset_current_mems_allowed,
2277				&preferred_zone);
2278	if (!preferred_zone) {
2279		put_mems_allowed();
2280		return NULL;
2281	}
2282
 
 
 
 
 
2283	/* First allocation attempt */
2284	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2285			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
2286			preferred_zone, migratetype);
2287	if (unlikely(!page))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2288		page = __alloc_pages_slowpath(gfp_mask, order,
2289				zonelist, high_zoneidx, nodemask,
2290				preferred_zone, migratetype);
2291	put_mems_allowed();
2292
2293	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
 
 
 
 
 
 
 
 
 
 
 
 
 
2294	return page;
2295}
2296EXPORT_SYMBOL(__alloc_pages_nodemask);
2297
2298/*
2299 * Common helper functions.
2300 */
2301unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2302{
2303	struct page *page;
2304
2305	/*
2306	 * __get_free_pages() returns a 32-bit address, which cannot represent
2307	 * a highmem page
2308	 */
2309	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2310
2311	page = alloc_pages(gfp_mask, order);
2312	if (!page)
2313		return 0;
2314	return (unsigned long) page_address(page);
2315}
2316EXPORT_SYMBOL(__get_free_pages);
2317
2318unsigned long get_zeroed_page(gfp_t gfp_mask)
2319{
2320	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2321}
2322EXPORT_SYMBOL(get_zeroed_page);
2323
2324void __pagevec_free(struct pagevec *pvec)
2325{
2326	int i = pagevec_count(pvec);
2327
2328	while (--i >= 0) {
2329		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
2330		free_hot_cold_page(pvec->pages[i], pvec->cold);
2331	}
2332}
2333
2334void __free_pages(struct page *page, unsigned int order)
2335{
2336	if (put_page_testzero(page)) {
2337		if (order == 0)
2338			free_hot_cold_page(page, 0);
2339		else
2340			__free_pages_ok(page, order);
2341	}
2342}
2343
2344EXPORT_SYMBOL(__free_pages);
2345
2346void free_pages(unsigned long addr, unsigned int order)
2347{
2348	if (addr != 0) {
2349		VM_BUG_ON(!virt_addr_valid((void *)addr));
2350		__free_pages(virt_to_page((void *)addr), order);
2351	}
2352}
2353
2354EXPORT_SYMBOL(free_pages);
2355
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2356static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2357{
2358	if (addr) {
2359		unsigned long alloc_end = addr + (PAGE_SIZE << order);
2360		unsigned long used = addr + PAGE_ALIGN(size);
2361
2362		split_page(virt_to_page((void *)addr), order);
2363		while (used < alloc_end) {
2364			free_page(used);
2365			used += PAGE_SIZE;
2366		}
2367	}
2368	return (void *)addr;
2369}
2370
2371/**
2372 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2373 * @size: the number of bytes to allocate
2374 * @gfp_mask: GFP flags for the allocation
2375 *
2376 * This function is similar to alloc_pages(), except that it allocates the
2377 * minimum number of pages to satisfy the request.  alloc_pages() can only
2378 * allocate memory in power-of-two pages.
2379 *
2380 * This function is also limited by MAX_ORDER.
2381 *
2382 * Memory allocated by this function must be released by free_pages_exact().
2383 */
2384void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2385{
2386	unsigned int order = get_order(size);
2387	unsigned long addr;
2388
2389	addr = __get_free_pages(gfp_mask, order);
2390	return make_alloc_exact(addr, order, size);
2391}
2392EXPORT_SYMBOL(alloc_pages_exact);
2393
2394/**
2395 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2396 *			   pages on a node.
2397 * @nid: the preferred node ID where memory should be allocated
2398 * @size: the number of bytes to allocate
2399 * @gfp_mask: GFP flags for the allocation
2400 *
2401 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2402 * back.
2403 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2404 * but is not exact.
2405 */
2406void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2407{
2408	unsigned order = get_order(size);
2409	struct page *p = alloc_pages_node(nid, gfp_mask, order);
2410	if (!p)
2411		return NULL;
2412	return make_alloc_exact((unsigned long)page_address(p), order, size);
2413}
2414EXPORT_SYMBOL(alloc_pages_exact_nid);
2415
2416/**
2417 * free_pages_exact - release memory allocated via alloc_pages_exact()
2418 * @virt: the value returned by alloc_pages_exact.
2419 * @size: size of allocation, same value as passed to alloc_pages_exact().
2420 *
2421 * Release the memory allocated by a previous call to alloc_pages_exact.
2422 */
2423void free_pages_exact(void *virt, size_t size)
2424{
2425	unsigned long addr = (unsigned long)virt;
2426	unsigned long end = addr + PAGE_ALIGN(size);
2427
2428	while (addr < end) {
2429		free_page(addr);
2430		addr += PAGE_SIZE;
2431	}
2432}
2433EXPORT_SYMBOL(free_pages_exact);
2434
2435static unsigned int nr_free_zone_pages(int offset)
 
 
 
 
 
 
 
 
 
2436{
2437	struct zoneref *z;
2438	struct zone *zone;
2439
2440	/* Just pick one node, since fallback list is circular */
2441	unsigned int sum = 0;
2442
2443	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2444
2445	for_each_zone_zonelist(zone, z, zonelist, offset) {
2446		unsigned long size = zone->present_pages;
2447		unsigned long high = high_wmark_pages(zone);
2448		if (size > high)
2449			sum += size - high;
2450	}
2451
2452	return sum;
2453}
2454
2455/*
2456 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
 
 
 
2457 */
2458unsigned int nr_free_buffer_pages(void)
2459{
2460	return nr_free_zone_pages(gfp_zone(GFP_USER));
2461}
2462EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2463
2464/*
2465 * Amount of free RAM allocatable within all zones
 
 
 
2466 */
2467unsigned int nr_free_pagecache_pages(void)
2468{
2469	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2470}
2471
2472static inline void show_node(struct zone *zone)
2473{
2474	if (NUMA_BUILD)
2475		printk("Node %d ", zone_to_nid(zone));
2476}
2477
2478void si_meminfo(struct sysinfo *val)
2479{
2480	val->totalram = totalram_pages;
2481	val->sharedram = 0;
2482	val->freeram = global_page_state(NR_FREE_PAGES);
2483	val->bufferram = nr_blockdev_pages();
2484	val->totalhigh = totalhigh_pages;
2485	val->freehigh = nr_free_highpages();
2486	val->mem_unit = PAGE_SIZE;
2487}
2488
2489EXPORT_SYMBOL(si_meminfo);
2490
2491#ifdef CONFIG_NUMA
2492void si_meminfo_node(struct sysinfo *val, int nid)
2493{
 
 
2494	pg_data_t *pgdat = NODE_DATA(nid);
2495
2496	val->totalram = pgdat->node_present_pages;
 
 
2497	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2498#ifdef CONFIG_HIGHMEM
2499	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2500	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2501			NR_FREE_PAGES);
2502#else
2503	val->totalhigh = 0;
2504	val->freehigh = 0;
2505#endif
2506	val->mem_unit = PAGE_SIZE;
2507}
2508#endif
2509
2510/*
2511 * Determine whether the node should be displayed or not, depending on whether
2512 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2513 */
2514bool skip_free_areas_node(unsigned int flags, int nid)
2515{
2516	bool ret = false;
 
2517
2518	if (!(flags & SHOW_MEM_FILTER_NODES))
2519		goto out;
2520
2521	get_mems_allowed();
2522	ret = !node_isset(nid, cpuset_current_mems_allowed);
2523	put_mems_allowed();
 
2524out:
2525	return ret;
2526}
2527
2528#define K(x) ((x) << (PAGE_SHIFT-10))
2529
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2530/*
2531 * Show free area list (used inside shift_scroll-lock stuff)
2532 * We also calculate the percentage fragmentation. We do this by counting the
2533 * memory on each free list with the exception of the first item on the list.
2534 * Suppresses nodes that are not allowed by current's cpuset if
2535 * SHOW_MEM_FILTER_NODES is passed.
2536 */
2537void show_free_areas(unsigned int filter)
2538{
2539	int cpu;
2540	struct zone *zone;
2541
2542	for_each_populated_zone(zone) {
2543		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2544			continue;
2545		show_node(zone);
2546		printk("%s per-cpu:\n", zone->name);
2547
2548		for_each_online_cpu(cpu) {
2549			struct per_cpu_pageset *pageset;
2550
2551			pageset = per_cpu_ptr(zone->pageset, cpu);
2552
2553			printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2554			       cpu, pageset->pcp.high,
2555			       pageset->pcp.batch, pageset->pcp.count);
2556		}
2557	}
2558
2559	printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2560		" active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2561		" unevictable:%lu"
2562		" dirty:%lu writeback:%lu unstable:%lu\n"
2563		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2564		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
 
2565		global_page_state(NR_ACTIVE_ANON),
2566		global_page_state(NR_INACTIVE_ANON),
2567		global_page_state(NR_ISOLATED_ANON),
2568		global_page_state(NR_ACTIVE_FILE),
2569		global_page_state(NR_INACTIVE_FILE),
2570		global_page_state(NR_ISOLATED_FILE),
2571		global_page_state(NR_UNEVICTABLE),
2572		global_page_state(NR_FILE_DIRTY),
2573		global_page_state(NR_WRITEBACK),
2574		global_page_state(NR_UNSTABLE_NFS),
2575		global_page_state(NR_FREE_PAGES),
2576		global_page_state(NR_SLAB_RECLAIMABLE),
2577		global_page_state(NR_SLAB_UNRECLAIMABLE),
2578		global_page_state(NR_FILE_MAPPED),
2579		global_page_state(NR_SHMEM),
2580		global_page_state(NR_PAGETABLE),
2581		global_page_state(NR_BOUNCE));
 
2582
2583	for_each_populated_zone(zone) {
2584		int i;
2585
2586		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2587			continue;
2588		show_node(zone);
2589		printk("%s"
2590			" free:%lukB"
2591			" min:%lukB"
2592			" low:%lukB"
2593			" high:%lukB"
2594			" active_anon:%lukB"
2595			" inactive_anon:%lukB"
2596			" active_file:%lukB"
2597			" inactive_file:%lukB"
2598			" unevictable:%lukB"
2599			" isolated(anon):%lukB"
2600			" isolated(file):%lukB"
2601			" present:%lukB"
 
2602			" mlocked:%lukB"
2603			" dirty:%lukB"
2604			" writeback:%lukB"
2605			" mapped:%lukB"
2606			" shmem:%lukB"
2607			" slab_reclaimable:%lukB"
2608			" slab_unreclaimable:%lukB"
2609			" kernel_stack:%lukB"
2610			" pagetables:%lukB"
2611			" unstable:%lukB"
2612			" bounce:%lukB"
 
2613			" writeback_tmp:%lukB"
2614			" pages_scanned:%lu"
2615			" all_unreclaimable? %s"
2616			"\n",
2617			zone->name,
2618			K(zone_page_state(zone, NR_FREE_PAGES)),
2619			K(min_wmark_pages(zone)),
2620			K(low_wmark_pages(zone)),
2621			K(high_wmark_pages(zone)),
2622			K(zone_page_state(zone, NR_ACTIVE_ANON)),
2623			K(zone_page_state(zone, NR_INACTIVE_ANON)),
2624			K(zone_page_state(zone, NR_ACTIVE_FILE)),
2625			K(zone_page_state(zone, NR_INACTIVE_FILE)),
2626			K(zone_page_state(zone, NR_UNEVICTABLE)),
2627			K(zone_page_state(zone, NR_ISOLATED_ANON)),
2628			K(zone_page_state(zone, NR_ISOLATED_FILE)),
2629			K(zone->present_pages),
 
2630			K(zone_page_state(zone, NR_MLOCK)),
2631			K(zone_page_state(zone, NR_FILE_DIRTY)),
2632			K(zone_page_state(zone, NR_WRITEBACK)),
2633			K(zone_page_state(zone, NR_FILE_MAPPED)),
2634			K(zone_page_state(zone, NR_SHMEM)),
2635			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
2636			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2637			zone_page_state(zone, NR_KERNEL_STACK) *
2638				THREAD_SIZE / 1024,
2639			K(zone_page_state(zone, NR_PAGETABLE)),
2640			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
2641			K(zone_page_state(zone, NR_BOUNCE)),
 
2642			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
2643			zone->pages_scanned,
2644			(zone->all_unreclaimable ? "yes" : "no")
2645			);
2646		printk("lowmem_reserve[]:");
2647		for (i = 0; i < MAX_NR_ZONES; i++)
2648			printk(" %lu", zone->lowmem_reserve[i]);
2649		printk("\n");
2650	}
2651
2652	for_each_populated_zone(zone) {
2653 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
 
2654
2655		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2656			continue;
2657		show_node(zone);
2658		printk("%s: ", zone->name);
2659
2660		spin_lock_irqsave(&zone->lock, flags);
2661		for (order = 0; order < MAX_ORDER; order++) {
2662			nr[order] = zone->free_area[order].nr_free;
 
 
 
2663			total += nr[order] << order;
 
 
 
 
 
 
2664		}
2665		spin_unlock_irqrestore(&zone->lock, flags);
2666		for (order = 0; order < MAX_ORDER; order++)
2667			printk("%lu*%lukB ", nr[order], K(1UL) << order);
 
 
 
2668		printk("= %lukB\n", K(total));
2669	}
2670
 
 
2671	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
2672
2673	show_swap_cache_info();
2674}
2675
2676static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
2677{
2678	zoneref->zone = zone;
2679	zoneref->zone_idx = zone_idx(zone);
2680}
2681
2682/*
2683 * Builds allocation fallback zone lists.
2684 *
2685 * Add all populated zones of a node to the zonelist.
2686 */
2687static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
2688				int nr_zones, enum zone_type zone_type)
2689{
2690	struct zone *zone;
2691
2692	BUG_ON(zone_type >= MAX_NR_ZONES);
2693	zone_type++;
2694
2695	do {
2696		zone_type--;
2697		zone = pgdat->node_zones + zone_type;
2698		if (populated_zone(zone)) {
2699			zoneref_set_zone(zone,
2700				&zonelist->_zonerefs[nr_zones++]);
2701			check_highest_zone(zone_type);
2702		}
2703
2704	} while (zone_type);
 
2705	return nr_zones;
2706}
2707
2708
2709/*
2710 *  zonelist_order:
2711 *  0 = automatic detection of better ordering.
2712 *  1 = order by ([node] distance, -zonetype)
2713 *  2 = order by (-zonetype, [node] distance)
2714 *
2715 *  If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2716 *  the same zonelist. So only NUMA can configure this param.
2717 */
2718#define ZONELIST_ORDER_DEFAULT  0
2719#define ZONELIST_ORDER_NODE     1
2720#define ZONELIST_ORDER_ZONE     2
2721
2722/* zonelist order in the kernel.
2723 * set_zonelist_order() will set this to NODE or ZONE.
2724 */
2725static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
2726static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
2727
2728
2729#ifdef CONFIG_NUMA
2730/* The value user specified ....changed by config */
2731static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2732/* string for sysctl */
2733#define NUMA_ZONELIST_ORDER_LEN	16
2734char numa_zonelist_order[16] = "default";
2735
2736/*
2737 * interface for configure zonelist ordering.
2738 * command line option "numa_zonelist_order"
2739 *	= "[dD]efault	- default, automatic configuration.
2740 *	= "[nN]ode 	- order by node locality, then by zone within node
2741 *	= "[zZ]one      - order by zone, then by locality within zone
2742 */
2743
2744static int __parse_numa_zonelist_order(char *s)
2745{
2746	if (*s == 'd' || *s == 'D') {
2747		user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2748	} else if (*s == 'n' || *s == 'N') {
2749		user_zonelist_order = ZONELIST_ORDER_NODE;
2750	} else if (*s == 'z' || *s == 'Z') {
2751		user_zonelist_order = ZONELIST_ORDER_ZONE;
2752	} else {
2753		printk(KERN_WARNING
2754			"Ignoring invalid numa_zonelist_order value:  "
2755			"%s\n", s);
2756		return -EINVAL;
2757	}
2758	return 0;
2759}
2760
2761static __init int setup_numa_zonelist_order(char *s)
2762{
2763	int ret;
2764
2765	if (!s)
2766		return 0;
2767
2768	ret = __parse_numa_zonelist_order(s);
2769	if (ret == 0)
2770		strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
2771
2772	return ret;
2773}
2774early_param("numa_zonelist_order", setup_numa_zonelist_order);
2775
2776/*
2777 * sysctl handler for numa_zonelist_order
2778 */
2779int numa_zonelist_order_handler(ctl_table *table, int write,
2780		void __user *buffer, size_t *length,
2781		loff_t *ppos)
2782{
2783	char saved_string[NUMA_ZONELIST_ORDER_LEN];
2784	int ret;
2785	static DEFINE_MUTEX(zl_order_mutex);
2786
2787	mutex_lock(&zl_order_mutex);
2788	if (write)
2789		strcpy(saved_string, (char*)table->data);
 
 
 
 
 
2790	ret = proc_dostring(table, write, buffer, length, ppos);
2791	if (ret)
2792		goto out;
2793	if (write) {
2794		int oldval = user_zonelist_order;
2795		if (__parse_numa_zonelist_order((char*)table->data)) {
 
 
2796			/*
2797			 * bogus value.  restore saved string
2798			 */
2799			strncpy((char*)table->data, saved_string,
2800				NUMA_ZONELIST_ORDER_LEN);
2801			user_zonelist_order = oldval;
2802		} else if (oldval != user_zonelist_order) {
2803			mutex_lock(&zonelists_mutex);
2804			build_all_zonelists(NULL);
2805			mutex_unlock(&zonelists_mutex);
2806		}
2807	}
2808out:
2809	mutex_unlock(&zl_order_mutex);
2810	return ret;
2811}
2812
2813
2814#define MAX_NODE_LOAD (nr_online_nodes)
2815static int node_load[MAX_NUMNODES];
2816
2817/**
2818 * find_next_best_node - find the next node that should appear in a given node's fallback list
2819 * @node: node whose fallback list we're appending
2820 * @used_node_mask: nodemask_t of already used nodes
2821 *
2822 * We use a number of factors to determine which is the next node that should
2823 * appear on a given node's fallback list.  The node should not have appeared
2824 * already in @node's fallback list, and it should be the next closest node
2825 * according to the distance array (which contains arbitrary distance values
2826 * from each node to each node in the system), and should also prefer nodes
2827 * with no CPUs, since presumably they'll have very little allocation pressure
2828 * on them otherwise.
2829 * It returns -1 if no node is found.
2830 */
2831static int find_next_best_node(int node, nodemask_t *used_node_mask)
2832{
2833	int n, val;
2834	int min_val = INT_MAX;
2835	int best_node = -1;
2836	const struct cpumask *tmp = cpumask_of_node(0);
2837
2838	/* Use the local node if we haven't already */
2839	if (!node_isset(node, *used_node_mask)) {
2840		node_set(node, *used_node_mask);
2841		return node;
2842	}
2843
2844	for_each_node_state(n, N_HIGH_MEMORY) {
2845
2846		/* Don't want a node to appear more than once */
2847		if (node_isset(n, *used_node_mask))
2848			continue;
2849
2850		/* Use the distance array to find the distance */
2851		val = node_distance(node, n);
2852
2853		/* Penalize nodes under us ("prefer the next node") */
2854		val += (n < node);
2855
2856		/* Give preference to headless and unused nodes */
2857		tmp = cpumask_of_node(n);
2858		if (!cpumask_empty(tmp))
2859			val += PENALTY_FOR_NODE_WITH_CPUS;
2860
2861		/* Slight preference for less loaded node */
2862		val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2863		val += node_load[n];
2864
2865		if (val < min_val) {
2866			min_val = val;
2867			best_node = n;
2868		}
2869	}
2870
2871	if (best_node >= 0)
2872		node_set(best_node, *used_node_mask);
2873
2874	return best_node;
2875}
2876
2877
2878/*
2879 * Build zonelists ordered by node and zones within node.
2880 * This results in maximum locality--normal zone overflows into local
2881 * DMA zone, if any--but risks exhausting DMA zone.
2882 */
2883static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2884{
2885	int j;
2886	struct zonelist *zonelist;
2887
2888	zonelist = &pgdat->node_zonelists[0];
2889	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2890		;
2891	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2892							MAX_NR_ZONES - 1);
2893	zonelist->_zonerefs[j].zone = NULL;
2894	zonelist->_zonerefs[j].zone_idx = 0;
2895}
2896
2897/*
2898 * Build gfp_thisnode zonelists
2899 */
2900static void build_thisnode_zonelists(pg_data_t *pgdat)
2901{
2902	int j;
2903	struct zonelist *zonelist;
2904
2905	zonelist = &pgdat->node_zonelists[1];
2906	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2907	zonelist->_zonerefs[j].zone = NULL;
2908	zonelist->_zonerefs[j].zone_idx = 0;
2909}
2910
2911/*
2912 * Build zonelists ordered by zone and nodes within zones.
2913 * This results in conserving DMA zone[s] until all Normal memory is
2914 * exhausted, but results in overflowing to remote node while memory
2915 * may still exist in local DMA zone.
2916 */
2917static int node_order[MAX_NUMNODES];
2918
2919static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2920{
2921	int pos, j, node;
2922	int zone_type;		/* needs to be signed */
2923	struct zone *z;
2924	struct zonelist *zonelist;
2925
2926	zonelist = &pgdat->node_zonelists[0];
2927	pos = 0;
2928	for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
2929		for (j = 0; j < nr_nodes; j++) {
2930			node = node_order[j];
2931			z = &NODE_DATA(node)->node_zones[zone_type];
2932			if (populated_zone(z)) {
2933				zoneref_set_zone(z,
2934					&zonelist->_zonerefs[pos++]);
2935				check_highest_zone(zone_type);
2936			}
2937		}
2938	}
2939	zonelist->_zonerefs[pos].zone = NULL;
2940	zonelist->_zonerefs[pos].zone_idx = 0;
2941}
2942
2943static int default_zonelist_order(void)
2944{
2945	int nid, zone_type;
2946	unsigned long low_kmem_size,total_size;
2947	struct zone *z;
2948	int average_size;
2949	/*
2950         * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2951	 * If they are really small and used heavily, the system can fall
2952	 * into OOM very easily.
2953	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
2954	 */
2955	/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2956	low_kmem_size = 0;
2957	total_size = 0;
2958	for_each_online_node(nid) {
2959		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2960			z = &NODE_DATA(nid)->node_zones[zone_type];
2961			if (populated_zone(z)) {
2962				if (zone_type < ZONE_NORMAL)
2963					low_kmem_size += z->present_pages;
2964				total_size += z->present_pages;
2965			} else if (zone_type == ZONE_NORMAL) {
2966				/*
2967				 * If any node has only lowmem, then node order
2968				 * is preferred to allow kernel allocations
2969				 * locally; otherwise, they can easily infringe
2970				 * on other nodes when there is an abundance of
2971				 * lowmem available to allocate from.
2972				 */
2973				return ZONELIST_ORDER_NODE;
2974			}
2975		}
2976	}
2977	if (!low_kmem_size ||  /* there are no DMA area. */
2978	    low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
2979		return ZONELIST_ORDER_NODE;
2980	/*
2981	 * look into each node's config.
2982  	 * If there is a node whose DMA/DMA32 memory is very big area on
2983 	 * local memory, NODE_ORDER may be suitable.
2984         */
2985	average_size = total_size /
2986				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2987	for_each_online_node(nid) {
2988		low_kmem_size = 0;
2989		total_size = 0;
2990		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2991			z = &NODE_DATA(nid)->node_zones[zone_type];
2992			if (populated_zone(z)) {
2993				if (zone_type < ZONE_NORMAL)
2994					low_kmem_size += z->present_pages;
2995				total_size += z->present_pages;
2996			}
2997		}
2998		if (low_kmem_size &&
2999		    total_size > average_size && /* ignore small node */
3000		    low_kmem_size > total_size * 70/100)
3001			return ZONELIST_ORDER_NODE;
3002	}
3003	return ZONELIST_ORDER_ZONE;
3004}
3005
3006static void set_zonelist_order(void)
3007{
3008	if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3009		current_zonelist_order = default_zonelist_order();
3010	else
3011		current_zonelist_order = user_zonelist_order;
3012}
3013
3014static void build_zonelists(pg_data_t *pgdat)
3015{
3016	int j, node, load;
3017	enum zone_type i;
3018	nodemask_t used_mask;
3019	int local_node, prev_node;
3020	struct zonelist *zonelist;
3021	int order = current_zonelist_order;
3022
3023	/* initialize zonelists */
3024	for (i = 0; i < MAX_ZONELISTS; i++) {
3025		zonelist = pgdat->node_zonelists + i;
3026		zonelist->_zonerefs[0].zone = NULL;
3027		zonelist->_zonerefs[0].zone_idx = 0;
3028	}
3029
3030	/* NUMA-aware ordering of nodes */
3031	local_node = pgdat->node_id;
3032	load = nr_online_nodes;
3033	prev_node = local_node;
3034	nodes_clear(used_mask);
3035
3036	memset(node_order, 0, sizeof(node_order));
3037	j = 0;
3038
3039	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3040		int distance = node_distance(local_node, node);
3041
3042		/*
3043		 * If another node is sufficiently far away then it is better
3044		 * to reclaim pages in a zone before going off node.
3045		 */
3046		if (distance > RECLAIM_DISTANCE)
3047			zone_reclaim_mode = 1;
3048
3049		/*
3050		 * We don't want to pressure a particular node.
3051		 * So adding penalty to the first node in same
3052		 * distance group to make it round-robin.
3053		 */
3054		if (distance != node_distance(local_node, prev_node))
 
3055			node_load[node] = load;
3056
3057		prev_node = node;
3058		load--;
3059		if (order == ZONELIST_ORDER_NODE)
3060			build_zonelists_in_node_order(pgdat, node);
3061		else
3062			node_order[j++] = node;	/* remember order */
3063	}
3064
3065	if (order == ZONELIST_ORDER_ZONE) {
3066		/* calculate node order -- i.e., DMA last! */
3067		build_zonelists_in_zone_order(pgdat, j);
3068	}
3069
3070	build_thisnode_zonelists(pgdat);
3071}
3072
3073/* Construct the zonelist performance cache - see further mmzone.h */
3074static void build_zonelist_cache(pg_data_t *pgdat)
3075{
3076	struct zonelist *zonelist;
3077	struct zonelist_cache *zlc;
3078	struct zoneref *z;
3079
3080	zonelist = &pgdat->node_zonelists[0];
3081	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3082	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3083	for (z = zonelist->_zonerefs; z->zone; z++)
3084		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3085}
3086
3087#ifdef CONFIG_HAVE_MEMORYLESS_NODES
3088/*
3089 * Return node id of node used for "local" allocations.
3090 * I.e., first node id of first zone in arg node's generic zonelist.
3091 * Used for initializing percpu 'numa_mem', which is used primarily
3092 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3093 */
3094int local_memory_node(int node)
3095{
3096	struct zone *zone;
3097
3098	(void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3099				   gfp_zone(GFP_KERNEL),
3100				   NULL,
3101				   &zone);
3102	return zone->node;
3103}
3104#endif
3105
3106#else	/* CONFIG_NUMA */
3107
3108static void set_zonelist_order(void)
3109{
3110	current_zonelist_order = ZONELIST_ORDER_ZONE;
3111}
3112
3113static void build_zonelists(pg_data_t *pgdat)
3114{
3115	int node, local_node;
3116	enum zone_type j;
3117	struct zonelist *zonelist;
3118
3119	local_node = pgdat->node_id;
3120
3121	zonelist = &pgdat->node_zonelists[0];
3122	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3123
3124	/*
3125	 * Now we build the zonelist so that it contains the zones
3126	 * of all the other nodes.
3127	 * We don't want to pressure a particular node, so when
3128	 * building the zones for node N, we make sure that the
3129	 * zones coming right after the local ones are those from
3130	 * node N+1 (modulo N)
3131	 */
3132	for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3133		if (!node_online(node))
3134			continue;
3135		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3136							MAX_NR_ZONES - 1);
3137	}
3138	for (node = 0; node < local_node; node++) {
3139		if (!node_online(node))
3140			continue;
3141		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3142							MAX_NR_ZONES - 1);
3143	}
3144
3145	zonelist->_zonerefs[j].zone = NULL;
3146	zonelist->_zonerefs[j].zone_idx = 0;
3147}
3148
3149/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3150static void build_zonelist_cache(pg_data_t *pgdat)
3151{
3152	pgdat->node_zonelists[0].zlcache_ptr = NULL;
3153}
3154
3155#endif	/* CONFIG_NUMA */
3156
3157/*
3158 * Boot pageset table. One per cpu which is going to be used for all
3159 * zones and all nodes. The parameters will be set in such a way
3160 * that an item put on a list will immediately be handed over to
3161 * the buddy list. This is safe since pageset manipulation is done
3162 * with interrupts disabled.
3163 *
3164 * The boot_pagesets must be kept even after bootup is complete for
3165 * unused processors and/or zones. They do play a role for bootstrapping
3166 * hotplugged processors.
3167 *
3168 * zoneinfo_show() and maybe other functions do
3169 * not check if the processor is online before following the pageset pointer.
3170 * Other parts of the kernel may not check if the zone is available.
3171 */
3172static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3173static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3174static void setup_zone_pageset(struct zone *zone);
3175
3176/*
3177 * Global mutex to protect against size modification of zonelists
3178 * as well as to serialize pageset setup for the new populated zone.
3179 */
3180DEFINE_MUTEX(zonelists_mutex);
3181
3182/* return values int ....just for stop_machine() */
3183static __init_refok int __build_all_zonelists(void *data)
3184{
3185	int nid;
3186	int cpu;
 
3187
3188#ifdef CONFIG_NUMA
3189	memset(node_load, 0, sizeof(node_load));
3190#endif
 
 
 
 
 
 
3191	for_each_online_node(nid) {
3192		pg_data_t *pgdat = NODE_DATA(nid);
3193
3194		build_zonelists(pgdat);
3195		build_zonelist_cache(pgdat);
3196	}
3197
3198	/*
3199	 * Initialize the boot_pagesets that are going to be used
3200	 * for bootstrapping processors. The real pagesets for
3201	 * each zone will be allocated later when the per cpu
3202	 * allocator is available.
3203	 *
3204	 * boot_pagesets are used also for bootstrapping offline
3205	 * cpus if the system is already booted because the pagesets
3206	 * are needed to initialize allocators on a specific cpu too.
3207	 * F.e. the percpu allocator needs the page allocator which
3208	 * needs the percpu allocator in order to allocate its pagesets
3209	 * (a chicken-egg dilemma).
3210	 */
3211	for_each_possible_cpu(cpu) {
3212		setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3213
3214#ifdef CONFIG_HAVE_MEMORYLESS_NODES
3215		/*
3216		 * We now know the "local memory node" for each node--
3217		 * i.e., the node of the first zone in the generic zonelist.
3218		 * Set up numa_mem percpu variable for on-line cpus.  During
3219		 * boot, only the boot cpu should be on-line;  we'll init the
3220		 * secondary cpus' numa_mem as they come on-line.  During
3221		 * node/memory hotplug, we'll fixup all on-line cpus.
3222		 */
3223		if (cpu_online(cpu))
3224			set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3225#endif
3226	}
3227
3228	return 0;
3229}
3230
3231/*
3232 * Called with zonelists_mutex held always
3233 * unless system_state == SYSTEM_BOOTING.
3234 */
3235void __ref build_all_zonelists(void *data)
3236{
3237	set_zonelist_order();
3238
3239	if (system_state == SYSTEM_BOOTING) {
3240		__build_all_zonelists(NULL);
3241		mminit_verify_zonelist();
3242		cpuset_init_current_mems_allowed();
3243	} else {
3244		/* we have to stop all cpus to guarantee there is no user
3245		   of zonelist */
3246#ifdef CONFIG_MEMORY_HOTPLUG
3247		if (data)
3248			setup_zone_pageset((struct zone *)data);
3249#endif
3250		stop_machine(__build_all_zonelists, NULL, NULL);
 
 
3251		/* cpuset refresh routine should be here */
3252	}
3253	vm_total_pages = nr_free_pagecache_pages();
3254	/*
3255	 * Disable grouping by mobility if the number of pages in the
3256	 * system is too low to allow the mechanism to work. It would be
3257	 * more accurate, but expensive to check per-zone. This check is
3258	 * made on memory-hotadd so a system can start with mobility
3259	 * disabled and enable it later
3260	 */
3261	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3262		page_group_by_mobility_disabled = 1;
3263	else
3264		page_group_by_mobility_disabled = 0;
3265
3266	printk("Built %i zonelists in %s order, mobility grouping %s.  "
3267		"Total pages: %ld\n",
3268			nr_online_nodes,
3269			zonelist_order_name[current_zonelist_order],
3270			page_group_by_mobility_disabled ? "off" : "on",
3271			vm_total_pages);
3272#ifdef CONFIG_NUMA
3273	printk("Policy zone: %s\n", zone_names[policy_zone]);
3274#endif
3275}
3276
3277/*
3278 * Helper functions to size the waitqueue hash table.
3279 * Essentially these want to choose hash table sizes sufficiently
3280 * large so that collisions trying to wait on pages are rare.
3281 * But in fact, the number of active page waitqueues on typical
3282 * systems is ridiculously low, less than 200. So this is even
3283 * conservative, even though it seems large.
3284 *
3285 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3286 * waitqueues, i.e. the size of the waitq table given the number of pages.
3287 */
3288#define PAGES_PER_WAITQUEUE	256
3289
3290#ifndef CONFIG_MEMORY_HOTPLUG
3291static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3292{
3293	unsigned long size = 1;
3294
3295	pages /= PAGES_PER_WAITQUEUE;
3296
3297	while (size < pages)
3298		size <<= 1;
3299
3300	/*
3301	 * Once we have dozens or even hundreds of threads sleeping
3302	 * on IO we've got bigger problems than wait queue collision.
3303	 * Limit the size of the wait table to a reasonable size.
3304	 */
3305	size = min(size, 4096UL);
3306
3307	return max(size, 4UL);
3308}
3309#else
3310/*
3311 * A zone's size might be changed by hot-add, so it is not possible to determine
3312 * a suitable size for its wait_table.  So we use the maximum size now.
3313 *
3314 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
3315 *
3316 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
3317 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3318 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
3319 *
3320 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3321 * or more by the traditional way. (See above).  It equals:
3322 *
3323 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
3324 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
3325 *    powerpc (64K page size)             : =  (32G +16M)byte.
3326 */
3327static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3328{
3329	return 4096UL;
3330}
3331#endif
3332
3333/*
3334 * This is an integer logarithm so that shifts can be used later
3335 * to extract the more random high bits from the multiplicative
3336 * hash function before the remainder is taken.
3337 */
3338static inline unsigned long wait_table_bits(unsigned long size)
3339{
3340	return ffz(~size);
3341}
3342
3343#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3344
3345/*
3346 * Check if a pageblock contains reserved pages
3347 */
3348static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3349{
3350	unsigned long pfn;
3351
3352	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3353		if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3354			return 1;
3355	}
3356	return 0;
3357}
3358
3359/*
3360 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3361 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3362 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3363 * higher will lead to a bigger reserve which will get freed as contiguous
3364 * blocks as reclaim kicks in
3365 */
3366static void setup_zone_migrate_reserve(struct zone *zone)
3367{
3368	unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3369	struct page *page;
3370	unsigned long block_migratetype;
3371	int reserve;
 
3372
3373	/* Get the start pfn, end pfn and the number of blocks to reserve */
 
 
 
 
 
3374	start_pfn = zone->zone_start_pfn;
3375	end_pfn = start_pfn + zone->spanned_pages;
 
3376	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3377							pageblock_order;
3378
3379	/*
3380	 * Reserve blocks are generally in place to help high-order atomic
3381	 * allocations that are short-lived. A min_free_kbytes value that
3382	 * would result in more than 2 reserve blocks for atomic allocations
3383	 * is assumed to be in place to help anti-fragmentation for the
3384	 * future allocation of hugepages at runtime.
3385	 */
3386	reserve = min(2, reserve);
 
 
 
 
 
 
3387
3388	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3389		if (!pfn_valid(pfn))
3390			continue;
3391		page = pfn_to_page(pfn);
3392
3393		/* Watch out for overlapping nodes */
3394		if (page_to_nid(page) != zone_to_nid(zone))
3395			continue;
3396
3397		/* Blocks with reserved pages will never free, skip them. */
3398		block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
3399		if (pageblock_is_reserved(pfn, block_end_pfn))
3400			continue;
3401
3402		block_migratetype = get_pageblock_migratetype(page);
3403
3404		/* If this block is reserved, account for it */
3405		if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
3406			reserve--;
3407			continue;
3408		}
 
 
 
 
3409
3410		/* Suitable for reserving if this block is movable */
3411		if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
3412			set_pageblock_migratetype(page, MIGRATE_RESERVE);
3413			move_freepages_block(zone, page, MIGRATE_RESERVE);
3414			reserve--;
3415			continue;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3416		}
3417
3418		/*
3419		 * If the reserve is met and this is a previous reserved block,
3420		 * take it back
3421		 */
3422		if (block_migratetype == MIGRATE_RESERVE) {
3423			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3424			move_freepages_block(zone, page, MIGRATE_MOVABLE);
3425		}
3426	}
3427}
3428
3429/*
3430 * Initially all pages are reserved - free ones are freed
3431 * up by free_all_bootmem() once the early boot process is
3432 * done. Non-atomic initialization, single-pass.
3433 */
3434void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
3435		unsigned long start_pfn, enum memmap_context context)
3436{
3437	struct page *page;
3438	unsigned long end_pfn = start_pfn + size;
3439	unsigned long pfn;
3440	struct zone *z;
3441
3442	if (highest_memmap_pfn < end_pfn - 1)
3443		highest_memmap_pfn = end_pfn - 1;
3444
3445	z = &NODE_DATA(nid)->node_zones[zone];
3446	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3447		/*
3448		 * There can be holes in boot-time mem_map[]s
3449		 * handed to this function.  They do not
3450		 * exist on hotplugged memory.
3451		 */
3452		if (context == MEMMAP_EARLY) {
3453			if (!early_pfn_valid(pfn))
3454				continue;
3455			if (!early_pfn_in_nid(pfn, nid))
3456				continue;
3457		}
3458		page = pfn_to_page(pfn);
3459		set_page_links(page, zone, nid, pfn);
3460		mminit_verify_page_links(page, zone, nid, pfn);
3461		init_page_count(page);
3462		reset_page_mapcount(page);
 
3463		SetPageReserved(page);
3464		/*
3465		 * Mark the block movable so that blocks are reserved for
3466		 * movable at startup. This will force kernel allocations
3467		 * to reserve their blocks rather than leaking throughout
3468		 * the address space during boot when many long-lived
3469		 * kernel allocations are made. Later some blocks near
3470		 * the start are marked MIGRATE_RESERVE by
3471		 * setup_zone_migrate_reserve()
3472		 *
3473		 * bitmap is created for zone's valid pfn range. but memmap
3474		 * can be created for invalid pages (for alignment)
3475		 * check here not to call set_pageblock_migratetype() against
3476		 * pfn out of zone.
3477		 */
3478		if ((z->zone_start_pfn <= pfn)
3479		    && (pfn < z->zone_start_pfn + z->spanned_pages)
3480		    && !(pfn & (pageblock_nr_pages - 1)))
3481			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3482
3483		INIT_LIST_HEAD(&page->lru);
3484#ifdef WANT_PAGE_VIRTUAL
3485		/* The shift won't overflow because ZONE_NORMAL is below 4G. */
3486		if (!is_highmem_idx(zone))
3487			set_page_address(page, __va(pfn << PAGE_SHIFT));
3488#endif
3489	}
3490}
3491
3492static void __meminit zone_init_free_lists(struct zone *zone)
3493{
3494	int order, t;
3495	for_each_migratetype_order(order, t) {
3496		INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
3497		zone->free_area[order].nr_free = 0;
3498	}
3499}
3500
3501#ifndef __HAVE_ARCH_MEMMAP_INIT
3502#define memmap_init(size, nid, zone, start_pfn) \
3503	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3504#endif
3505
3506static int zone_batchsize(struct zone *zone)
3507{
3508#ifdef CONFIG_MMU
3509	int batch;
3510
3511	/*
3512	 * The per-cpu-pages pools are set to around 1000th of the
3513	 * size of the zone.  But no more than 1/2 of a meg.
3514	 *
3515	 * OK, so we don't know how big the cache is.  So guess.
3516	 */
3517	batch = zone->present_pages / 1024;
3518	if (batch * PAGE_SIZE > 512 * 1024)
3519		batch = (512 * 1024) / PAGE_SIZE;
3520	batch /= 4;		/* We effectively *= 4 below */
3521	if (batch < 1)
3522		batch = 1;
3523
3524	/*
3525	 * Clamp the batch to a 2^n - 1 value. Having a power
3526	 * of 2 value was found to be more likely to have
3527	 * suboptimal cache aliasing properties in some cases.
3528	 *
3529	 * For example if 2 tasks are alternately allocating
3530	 * batches of pages, one task can end up with a lot
3531	 * of pages of one half of the possible page colors
3532	 * and the other with pages of the other colors.
3533	 */
3534	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3535
3536	return batch;
3537
3538#else
3539	/* The deferral and batching of frees should be suppressed under NOMMU
3540	 * conditions.
3541	 *
3542	 * The problem is that NOMMU needs to be able to allocate large chunks
3543	 * of contiguous memory as there's no hardware page translation to
3544	 * assemble apparent contiguous memory from discontiguous pages.
3545	 *
3546	 * Queueing large contiguous runs of pages for batching, however,
3547	 * causes the pages to actually be freed in smaller chunks.  As there
3548	 * can be a significant delay between the individual batches being
3549	 * recycled, this leads to the once large chunks of space being
3550	 * fragmented and becoming unavailable for high-order allocations.
3551	 */
3552	return 0;
3553#endif
3554}
3555
3556static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3557{
3558	struct per_cpu_pages *pcp;
3559	int migratetype;
3560
3561	memset(p, 0, sizeof(*p));
3562
3563	pcp = &p->pcp;
3564	pcp->count = 0;
3565	pcp->high = 6 * batch;
3566	pcp->batch = max(1UL, 1 * batch);
3567	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
3568		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3569}
3570
 
 
 
 
 
 
3571/*
3572 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3573 * to the value high for the pageset p.
3574 */
3575
3576static void setup_pagelist_highmark(struct per_cpu_pageset *p,
3577				unsigned long high)
3578{
3579	struct per_cpu_pages *pcp;
 
 
3580
3581	pcp = &p->pcp;
3582	pcp->high = high;
3583	pcp->batch = max(1UL, high/4);
3584	if ((high/4) > (PAGE_SHIFT * 8))
3585		pcp->batch = PAGE_SHIFT * 8;
3586}
3587
3588static void setup_zone_pageset(struct zone *zone)
 
3589{
3590	int cpu;
3591
3592	zone->pageset = alloc_percpu(struct per_cpu_pageset);
 
 
 
 
3593
3594	for_each_possible_cpu(cpu) {
3595		struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
 
3596
3597		setup_pageset(pcp, zone_batchsize(zone));
 
 
3598
3599		if (percpu_pagelist_fraction)
3600			setup_pagelist_highmark(pcp,
3601				(zone->present_pages /
3602					percpu_pagelist_fraction));
3603	}
 
3604}
3605
3606/*
3607 * Allocate per cpu pagesets and initialize them.
3608 * Before this call only boot pagesets were available.
3609 */
3610void __init setup_per_cpu_pageset(void)
3611{
3612	struct zone *zone;
3613
3614	for_each_populated_zone(zone)
3615		setup_zone_pageset(zone);
3616}
3617
3618static noinline __init_refok
3619int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3620{
3621	int i;
3622	struct pglist_data *pgdat = zone->zone_pgdat;
3623	size_t alloc_size;
3624
3625	/*
3626	 * The per-page waitqueue mechanism uses hashed waitqueues
3627	 * per zone.
3628	 */
3629	zone->wait_table_hash_nr_entries =
3630		 wait_table_hash_nr_entries(zone_size_pages);
3631	zone->wait_table_bits =
3632		wait_table_bits(zone->wait_table_hash_nr_entries);
3633	alloc_size = zone->wait_table_hash_nr_entries
3634					* sizeof(wait_queue_head_t);
3635
3636	if (!slab_is_available()) {
3637		zone->wait_table = (wait_queue_head_t *)
3638			alloc_bootmem_node_nopanic(pgdat, alloc_size);
 
3639	} else {
3640		/*
3641		 * This case means that a zone whose size was 0 gets new memory
3642		 * via memory hot-add.
3643		 * But it may be the case that a new node was hot-added.  In
3644		 * this case vmalloc() will not be able to use this new node's
3645		 * memory - this wait_table must be initialized to use this new
3646		 * node itself as well.
3647		 * To use this new node's memory, further consideration will be
3648		 * necessary.
3649		 */
3650		zone->wait_table = vmalloc(alloc_size);
3651	}
3652	if (!zone->wait_table)
3653		return -ENOMEM;
3654
3655	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3656		init_waitqueue_head(zone->wait_table + i);
3657
3658	return 0;
3659}
3660
3661static int __zone_pcp_update(void *data)
3662{
3663	struct zone *zone = data;
3664	int cpu;
3665	unsigned long batch = zone_batchsize(zone), flags;
3666
3667	for_each_possible_cpu(cpu) {
3668		struct per_cpu_pageset *pset;
3669		struct per_cpu_pages *pcp;
3670
3671		pset = per_cpu_ptr(zone->pageset, cpu);
3672		pcp = &pset->pcp;
3673
3674		local_irq_save(flags);
3675		free_pcppages_bulk(zone, pcp->count, pcp);
3676		setup_pageset(pset, batch);
3677		local_irq_restore(flags);
3678	}
3679	return 0;
3680}
3681
3682void zone_pcp_update(struct zone *zone)
3683{
3684	stop_machine(__zone_pcp_update, zone, NULL);
3685}
3686
3687static __meminit void zone_pcp_init(struct zone *zone)
3688{
3689	/*
3690	 * per cpu subsystem is not up at this point. The following code
3691	 * relies on the ability of the linker to provide the
3692	 * offset of a (static) per cpu variable into the per cpu area.
3693	 */
3694	zone->pageset = &boot_pageset;
3695
3696	if (zone->present_pages)
3697		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
3698			zone->name, zone->present_pages,
3699					 zone_batchsize(zone));
3700}
3701
3702__meminit int init_currently_empty_zone(struct zone *zone,
3703					unsigned long zone_start_pfn,
3704					unsigned long size,
3705					enum memmap_context context)
3706{
3707	struct pglist_data *pgdat = zone->zone_pgdat;
3708	int ret;
3709	ret = zone_wait_table_init(zone, size);
3710	if (ret)
3711		return ret;
3712	pgdat->nr_zones = zone_idx(zone) + 1;
3713
3714	zone->zone_start_pfn = zone_start_pfn;
3715
3716	mminit_dprintk(MMINIT_TRACE, "memmap_init",
3717			"Initialising map node %d zone %lu pfns %lu -> %lu\n",
3718			pgdat->node_id,
3719			(unsigned long)zone_idx(zone),
3720			zone_start_pfn, (zone_start_pfn + size));
3721
3722	zone_init_free_lists(zone);
3723
3724	return 0;
3725}
3726
3727#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3728/*
3729 * Basic iterator support. Return the first range of PFNs for a node
3730 * Note: nid == MAX_NUMNODES returns first region regardless of node
3731 */
3732static int __meminit first_active_region_index_in_nid(int nid)
3733{
3734	int i;
3735
3736	for (i = 0; i < nr_nodemap_entries; i++)
3737		if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3738			return i;
3739
3740	return -1;
3741}
3742
3743/*
3744 * Basic iterator support. Return the next active range of PFNs for a node
3745 * Note: nid == MAX_NUMNODES returns next region regardless of node
3746 */
3747static int __meminit next_active_region_index_in_nid(int index, int nid)
3748{
3749	for (index = index + 1; index < nr_nodemap_entries; index++)
3750		if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3751			return index;
3752
3753	return -1;
3754}
3755
3756#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3757/*
3758 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3759 * Architectures may implement their own version but if add_active_range()
3760 * was used and there are no special requirements, this is a convenient
3761 * alternative
3762 */
3763int __meminit __early_pfn_to_nid(unsigned long pfn)
3764{
3765	int i;
 
 
 
 
 
 
 
3766
3767	for (i = 0; i < nr_nodemap_entries; i++) {
3768		unsigned long start_pfn = early_node_map[i].start_pfn;
3769		unsigned long end_pfn = early_node_map[i].end_pfn;
3770
3771		if (start_pfn <= pfn && pfn < end_pfn)
3772			return early_node_map[i].nid;
 
 
 
3773	}
3774	/* This is a memory hole */
3775	return -1;
3776}
3777#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3778
3779int __meminit early_pfn_to_nid(unsigned long pfn)
3780{
3781	int nid;
3782
3783	nid = __early_pfn_to_nid(pfn);
3784	if (nid >= 0)
3785		return nid;
3786	/* just returns 0 */
3787	return 0;
3788}
3789
3790#ifdef CONFIG_NODES_SPAN_OTHER_NODES
3791bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
3792{
3793	int nid;
3794
3795	nid = __early_pfn_to_nid(pfn);
3796	if (nid >= 0 && nid != node)
3797		return false;
3798	return true;
3799}
3800#endif
3801
3802/* Basic iterator support to walk early_node_map[] */
3803#define for_each_active_range_index_in_nid(i, nid) \
3804	for (i = first_active_region_index_in_nid(nid); i != -1; \
3805				i = next_active_region_index_in_nid(i, nid))
3806
3807/**
3808 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3809 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3810 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3811 *
3812 * If an architecture guarantees that all ranges registered with
3813 * add_active_ranges() contain no holes and may be freed, this
3814 * this function may be used instead of calling free_bootmem() manually.
3815 */
3816void __init free_bootmem_with_active_regions(int nid,
3817						unsigned long max_low_pfn)
3818{
3819	int i;
3820
3821	for_each_active_range_index_in_nid(i, nid) {
3822		unsigned long size_pages = 0;
3823		unsigned long end_pfn = early_node_map[i].end_pfn;
3824
3825		if (early_node_map[i].start_pfn >= max_low_pfn)
3826			continue;
3827
3828		if (end_pfn > max_low_pfn)
3829			end_pfn = max_low_pfn;
3830
3831		size_pages = end_pfn - early_node_map[i].start_pfn;
3832		free_bootmem_node(NODE_DATA(early_node_map[i].nid),
3833				PFN_PHYS(early_node_map[i].start_pfn),
3834				size_pages << PAGE_SHIFT);
3835	}
3836}
3837
3838#ifdef CONFIG_HAVE_MEMBLOCK
3839/*
3840 * Basic iterator support. Return the last range of PFNs for a node
3841 * Note: nid == MAX_NUMNODES returns last region regardless of node
3842 */
3843static int __meminit last_active_region_index_in_nid(int nid)
3844{
3845	int i;
3846
3847	for (i = nr_nodemap_entries - 1; i >= 0; i--)
3848		if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3849			return i;
3850
3851	return -1;
3852}
3853
3854/*
3855 * Basic iterator support. Return the previous active range of PFNs for a node
3856 * Note: nid == MAX_NUMNODES returns next region regardless of node
3857 */
3858static int __meminit previous_active_region_index_in_nid(int index, int nid)
3859{
3860	for (index = index - 1; index >= 0; index--)
3861		if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3862			return index;
3863
3864	return -1;
3865}
3866
3867#define for_each_active_range_index_in_nid_reverse(i, nid) \
3868	for (i = last_active_region_index_in_nid(nid); i != -1; \
3869				i = previous_active_region_index_in_nid(i, nid))
3870
3871u64 __init find_memory_core_early(int nid, u64 size, u64 align,
3872					u64 goal, u64 limit)
3873{
3874	int i;
3875
3876	/* Need to go over early_node_map to find out good range for node */
3877	for_each_active_range_index_in_nid_reverse(i, nid) {
3878		u64 addr;
3879		u64 ei_start, ei_last;
3880		u64 final_start, final_end;
3881
3882		ei_last = early_node_map[i].end_pfn;
3883		ei_last <<= PAGE_SHIFT;
3884		ei_start = early_node_map[i].start_pfn;
3885		ei_start <<= PAGE_SHIFT;
3886
3887		final_start = max(ei_start, goal);
3888		final_end = min(ei_last, limit);
3889
3890		if (final_start >= final_end)
3891			continue;
3892
3893		addr = memblock_find_in_range(final_start, final_end, size, align);
3894
3895		if (addr == MEMBLOCK_ERROR)
3896			continue;
3897
3898		return addr;
3899	}
3900
3901	return MEMBLOCK_ERROR;
3902}
3903#endif
3904
3905int __init add_from_early_node_map(struct range *range, int az,
3906				   int nr_range, int nid)
3907{
3908	int i;
3909	u64 start, end;
3910
3911	/* need to go over early_node_map to find out good range for node */
3912	for_each_active_range_index_in_nid(i, nid) {
3913		start = early_node_map[i].start_pfn;
3914		end = early_node_map[i].end_pfn;
3915		nr_range = add_range(range, az, nr_range, start, end);
 
 
 
3916	}
3917	return nr_range;
3918}
3919
3920void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
3921{
3922	int i;
3923	int ret;
3924
3925	for_each_active_range_index_in_nid(i, nid) {
3926		ret = work_fn(early_node_map[i].start_pfn,
3927			      early_node_map[i].end_pfn, data);
3928		if (ret)
3929			break;
3930	}
3931}
3932/**
3933 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3934 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3935 *
3936 * If an architecture guarantees that all ranges registered with
3937 * add_active_ranges() contain no holes and may be freed, this
3938 * function may be used instead of calling memory_present() manually.
3939 */
3940void __init sparse_memory_present_with_active_regions(int nid)
3941{
3942	int i;
 
3943
3944	for_each_active_range_index_in_nid(i, nid)
3945		memory_present(early_node_map[i].nid,
3946				early_node_map[i].start_pfn,
3947				early_node_map[i].end_pfn);
3948}
3949
3950/**
3951 * get_pfn_range_for_nid - Return the start and end page frames for a node
3952 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3953 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3954 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3955 *
3956 * It returns the start and end page frame of a node based on information
3957 * provided by an arch calling add_active_range(). If called for a node
3958 * with no available memory, a warning is printed and the start and end
3959 * PFNs will be 0.
3960 */
3961void __meminit get_pfn_range_for_nid(unsigned int nid,
3962			unsigned long *start_pfn, unsigned long *end_pfn)
3963{
 
3964	int i;
 
3965	*start_pfn = -1UL;
3966	*end_pfn = 0;
3967
3968	for_each_active_range_index_in_nid(i, nid) {
3969		*start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
3970		*end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
3971	}
3972
3973	if (*start_pfn == -1UL)
3974		*start_pfn = 0;
3975}
3976
3977/*
3978 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3979 * assumption is made that zones within a node are ordered in monotonic
3980 * increasing memory addresses so that the "highest" populated zone is used
3981 */
3982static void __init find_usable_zone_for_movable(void)
3983{
3984	int zone_index;
3985	for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
3986		if (zone_index == ZONE_MOVABLE)
3987			continue;
3988
3989		if (arch_zone_highest_possible_pfn[zone_index] >
3990				arch_zone_lowest_possible_pfn[zone_index])
3991			break;
3992	}
3993
3994	VM_BUG_ON(zone_index == -1);
3995	movable_zone = zone_index;
3996}
3997
3998/*
3999 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4000 * because it is sized independent of architecture. Unlike the other zones,
4001 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4002 * in each node depending on the size of each node and how evenly kernelcore
4003 * is distributed. This helper function adjusts the zone ranges
4004 * provided by the architecture for a given node by using the end of the
4005 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4006 * zones within a node are in order of monotonic increases memory addresses
4007 */
4008static void __meminit adjust_zone_range_for_zone_movable(int nid,
4009					unsigned long zone_type,
4010					unsigned long node_start_pfn,
4011					unsigned long node_end_pfn,
4012					unsigned long *zone_start_pfn,
4013					unsigned long *zone_end_pfn)
4014{
4015	/* Only adjust if ZONE_MOVABLE is on this node */
4016	if (zone_movable_pfn[nid]) {
4017		/* Size ZONE_MOVABLE */
4018		if (zone_type == ZONE_MOVABLE) {
4019			*zone_start_pfn = zone_movable_pfn[nid];
4020			*zone_end_pfn = min(node_end_pfn,
4021				arch_zone_highest_possible_pfn[movable_zone]);
4022
4023		/* Adjust for ZONE_MOVABLE starting within this range */
4024		} else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4025				*zone_end_pfn > zone_movable_pfn[nid]) {
4026			*zone_end_pfn = zone_movable_pfn[nid];
4027
4028		/* Check if this whole range is within ZONE_MOVABLE */
4029		} else if (*zone_start_pfn >= zone_movable_pfn[nid])
4030			*zone_start_pfn = *zone_end_pfn;
4031	}
4032}
4033
4034/*
4035 * Return the number of pages a zone spans in a node, including holes
4036 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4037 */
4038static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4039					unsigned long zone_type,
 
 
4040					unsigned long *ignored)
4041{
4042	unsigned long node_start_pfn, node_end_pfn;
4043	unsigned long zone_start_pfn, zone_end_pfn;
4044
4045	/* Get the start and end of the node and zone */
4046	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4047	zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4048	zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4049	adjust_zone_range_for_zone_movable(nid, zone_type,
4050				node_start_pfn, node_end_pfn,
4051				&zone_start_pfn, &zone_end_pfn);
4052
4053	/* Check that this node has pages within the zone's required range */
4054	if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4055		return 0;
4056
4057	/* Move the zone boundaries inside the node if necessary */
4058	zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4059	zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4060
4061	/* Return the spanned pages */
4062	return zone_end_pfn - zone_start_pfn;
4063}
4064
4065/*
4066 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4067 * then all holes in the requested range will be accounted for.
4068 */
4069unsigned long __meminit __absent_pages_in_range(int nid,
4070				unsigned long range_start_pfn,
4071				unsigned long range_end_pfn)
4072{
4073	int i = 0;
4074	unsigned long prev_end_pfn = 0, hole_pages = 0;
4075	unsigned long start_pfn;
4076
4077	/* Find the end_pfn of the first active range of pfns in the node */
4078	i = first_active_region_index_in_nid(nid);
4079	if (i == -1)
4080		return 0;
4081
4082	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
4083
4084	/* Account for ranges before physical memory on this node */
4085	if (early_node_map[i].start_pfn > range_start_pfn)
4086		hole_pages = prev_end_pfn - range_start_pfn;
4087
4088	/* Find all holes for the zone within the node */
4089	for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
4090
4091		/* No need to continue if prev_end_pfn is outside the zone */
4092		if (prev_end_pfn >= range_end_pfn)
4093			break;
4094
4095		/* Make sure the end of the zone is not within the hole */
4096		start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
4097		prev_end_pfn = max(prev_end_pfn, range_start_pfn);
4098
4099		/* Update the hole size cound and move on */
4100		if (start_pfn > range_start_pfn) {
4101			BUG_ON(prev_end_pfn > start_pfn);
4102			hole_pages += start_pfn - prev_end_pfn;
4103		}
4104		prev_end_pfn = early_node_map[i].end_pfn;
4105	}
4106
4107	/* Account for ranges past physical memory on this node */
4108	if (range_end_pfn > prev_end_pfn)
4109		hole_pages += range_end_pfn -
4110				max(range_start_pfn, prev_end_pfn);
4111
4112	return hole_pages;
4113}
4114
4115/**
4116 * absent_pages_in_range - Return number of page frames in holes within a range
4117 * @start_pfn: The start PFN to start searching for holes
4118 * @end_pfn: The end PFN to stop searching for holes
4119 *
4120 * It returns the number of pages frames in memory holes within a range.
4121 */
4122unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4123							unsigned long end_pfn)
4124{
4125	return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4126}
4127
4128/* Return the number of page frames in holes in a zone on a node */
4129static unsigned long __meminit zone_absent_pages_in_node(int nid,
4130					unsigned long zone_type,
 
 
4131					unsigned long *ignored)
4132{
4133	unsigned long node_start_pfn, node_end_pfn;
 
4134	unsigned long zone_start_pfn, zone_end_pfn;
4135
4136	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4137	zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
4138							node_start_pfn);
4139	zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
4140							node_end_pfn);
4141
4142	adjust_zone_range_for_zone_movable(nid, zone_type,
4143			node_start_pfn, node_end_pfn,
4144			&zone_start_pfn, &zone_end_pfn);
4145	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4146}
4147
4148#else
4149static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4150					unsigned long zone_type,
 
 
4151					unsigned long *zones_size)
4152{
4153	return zones_size[zone_type];
4154}
4155
4156static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4157						unsigned long zone_type,
 
 
4158						unsigned long *zholes_size)
4159{
4160	if (!zholes_size)
4161		return 0;
4162
4163	return zholes_size[zone_type];
4164}
4165
4166#endif
4167
4168static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4169		unsigned long *zones_size, unsigned long *zholes_size)
 
 
 
4170{
4171	unsigned long realtotalpages, totalpages = 0;
4172	enum zone_type i;
4173
4174	for (i = 0; i < MAX_NR_ZONES; i++)
4175		totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4176								zones_size);
 
 
4177	pgdat->node_spanned_pages = totalpages;
4178
4179	realtotalpages = totalpages;
4180	for (i = 0; i < MAX_NR_ZONES; i++)
4181		realtotalpages -=
4182			zone_absent_pages_in_node(pgdat->node_id, i,
4183								zholes_size);
 
4184	pgdat->node_present_pages = realtotalpages;
4185	printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4186							realtotalpages);
4187}
4188
4189#ifndef CONFIG_SPARSEMEM
4190/*
4191 * Calculate the size of the zone->blockflags rounded to an unsigned long
4192 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4193 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4194 * round what is now in bits to nearest long in bits, then return it in
4195 * bytes.
4196 */
4197static unsigned long __init usemap_size(unsigned long zonesize)
4198{
4199	unsigned long usemapsize;
4200
 
4201	usemapsize = roundup(zonesize, pageblock_nr_pages);
4202	usemapsize = usemapsize >> pageblock_order;
4203	usemapsize *= NR_PAGEBLOCK_BITS;
4204	usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4205
4206	return usemapsize / 8;
4207}
4208
4209static void __init setup_usemap(struct pglist_data *pgdat,
4210				struct zone *zone, unsigned long zonesize)
 
 
4211{
4212	unsigned long usemapsize = usemap_size(zonesize);
4213	zone->pageblock_flags = NULL;
4214	if (usemapsize)
4215		zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
4216								   usemapsize);
 
4217}
4218#else
4219static inline void setup_usemap(struct pglist_data *pgdat,
4220				struct zone *zone, unsigned long zonesize) {}
4221#endif /* CONFIG_SPARSEMEM */
4222
4223#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4224
4225/* Return a sensible default order for the pageblock size. */
4226static inline int pageblock_default_order(void)
4227{
4228	if (HPAGE_SHIFT > PAGE_SHIFT)
4229		return HUGETLB_PAGE_ORDER;
4230
4231	return MAX_ORDER-1;
4232}
4233
4234/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4235static inline void __init set_pageblock_order(unsigned int order)
4236{
 
 
4237	/* Check that pageblock_nr_pages has not already been setup */
4238	if (pageblock_order)
4239		return;
4240
 
 
 
 
 
4241	/*
4242	 * Assume the largest contiguous order of interest is a huge page.
4243	 * This value may be variable depending on boot parameters on IA64
 
4244	 */
4245	pageblock_order = order;
4246}
4247#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4248
4249/*
4250 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4251 * and pageblock_default_order() are unused as pageblock_order is set
4252 * at compile-time. See include/linux/pageblock-flags.h for the values of
4253 * pageblock_order based on the kernel config
4254 */
4255static inline int pageblock_default_order(unsigned int order)
4256{
4257	return MAX_ORDER-1;
4258}
4259#define set_pageblock_order(x)	do {} while (0)
4260
4261#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4262
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4263/*
4264 * Set up the zone data structures:
4265 *   - mark all pages reserved
4266 *   - mark all memory queues empty
4267 *   - clear the memory bitmaps
 
 
4268 */
4269static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 
4270		unsigned long *zones_size, unsigned long *zholes_size)
4271{
4272	enum zone_type j;
4273	int nid = pgdat->node_id;
4274	unsigned long zone_start_pfn = pgdat->node_start_pfn;
4275	int ret;
4276
4277	pgdat_resize_init(pgdat);
4278	pgdat->nr_zones = 0;
 
 
 
 
4279	init_waitqueue_head(&pgdat->kswapd_wait);
4280	pgdat->kswapd_max_order = 0;
4281	pgdat_page_cgroup_init(pgdat);
4282	
4283	for (j = 0; j < MAX_NR_ZONES; j++) {
4284		struct zone *zone = pgdat->node_zones + j;
4285		unsigned long size, realsize, memmap_pages;
4286		enum lru_list l;
4287
4288		size = zone_spanned_pages_in_node(nid, j, zones_size);
4289		realsize = size - zone_absent_pages_in_node(nid, j,
 
 
 
4290								zholes_size);
4291
4292		/*
4293		 * Adjust realsize so that it accounts for how much memory
4294		 * is used by this zone for memmap. This affects the watermark
4295		 * and per-cpu initialisations
4296		 */
4297		memmap_pages =
4298			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4299		if (realsize >= memmap_pages) {
4300			realsize -= memmap_pages;
4301			if (memmap_pages)
4302				printk(KERN_DEBUG
4303				       "  %s zone: %lu pages used for memmap\n",
4304				       zone_names[j], memmap_pages);
4305		} else
4306			printk(KERN_WARNING
4307				"  %s zone: %lu pages exceeds realsize %lu\n",
4308				zone_names[j], memmap_pages, realsize);
4309
4310		/* Account for reserved pages */
4311		if (j == 0 && realsize > dma_reserve) {
4312			realsize -= dma_reserve;
4313			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
4314					zone_names[0], dma_reserve);
4315		}
4316
4317		if (!is_highmem_idx(j))
4318			nr_kernel_pages += realsize;
4319		nr_all_pages += realsize;
 
 
 
4320
4321		zone->spanned_pages = size;
4322		zone->present_pages = realsize;
 
 
 
 
 
 
4323#ifdef CONFIG_NUMA
4324		zone->node = nid;
4325		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4326						/ 100;
4327		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4328#endif
4329		zone->name = zone_names[j];
4330		spin_lock_init(&zone->lock);
4331		spin_lock_init(&zone->lru_lock);
4332		zone_seqlock_init(zone);
4333		zone->zone_pgdat = pgdat;
4334
4335		zone_pcp_init(zone);
4336		for_each_lru(l)
4337			INIT_LIST_HEAD(&zone->lru[l].list);
4338		zone->reclaim_stat.recent_rotated[0] = 0;
4339		zone->reclaim_stat.recent_rotated[1] = 0;
4340		zone->reclaim_stat.recent_scanned[0] = 0;
4341		zone->reclaim_stat.recent_scanned[1] = 0;
4342		zap_zone_vm_stats(zone);
4343		zone->flags = 0;
4344		if (!size)
4345			continue;
4346
4347		set_pageblock_order(pageblock_default_order());
4348		setup_usemap(pgdat, zone, size);
4349		ret = init_currently_empty_zone(zone, zone_start_pfn,
4350						size, MEMMAP_EARLY);
4351		BUG_ON(ret);
4352		memmap_init(size, nid, j, zone_start_pfn);
4353		zone_start_pfn += size;
4354	}
4355}
4356
4357static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4358{
4359	/* Skip empty nodes */
4360	if (!pgdat->node_spanned_pages)
4361		return;
4362
4363#ifdef CONFIG_FLAT_NODE_MEM_MAP
4364	/* ia64 gets its own node_mem_map, before this, without bootmem */
4365	if (!pgdat->node_mem_map) {
4366		unsigned long size, start, end;
4367		struct page *map;
4368
4369		/*
4370		 * The zone's endpoints aren't required to be MAX_ORDER
4371		 * aligned but the node_mem_map endpoints must be in order
4372		 * for the buddy allocator to function correctly.
4373		 */
4374		start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4375		end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
4376		end = ALIGN(end, MAX_ORDER_NR_PAGES);
4377		size =  (end - start) * sizeof(struct page);
4378		map = alloc_remap(pgdat->node_id, size);
4379		if (!map)
4380			map = alloc_bootmem_node_nopanic(pgdat, size);
 
4381		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4382	}
4383#ifndef CONFIG_NEED_MULTIPLE_NODES
4384	/*
4385	 * With no DISCONTIG, the global mem_map is just set as node 0's
4386	 */
4387	if (pgdat == NODE_DATA(0)) {
4388		mem_map = NODE_DATA(0)->node_mem_map;
4389#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4390		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4391			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4392#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4393	}
4394#endif
4395#endif /* CONFIG_FLAT_NODE_MEM_MAP */
4396}
4397
4398void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4399		unsigned long node_start_pfn, unsigned long *zholes_size)
4400{
4401	pg_data_t *pgdat = NODE_DATA(nid);
 
 
 
 
 
4402
4403	pgdat->node_id = nid;
4404	pgdat->node_start_pfn = node_start_pfn;
4405	calculate_node_totalpages(pgdat, zones_size, zholes_size);
 
 
 
 
 
 
4406
4407	alloc_node_mem_map(pgdat);
4408#ifdef CONFIG_FLAT_NODE_MEM_MAP
4409	printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4410		nid, (unsigned long)pgdat,
4411		(unsigned long)pgdat->node_mem_map);
4412#endif
4413
4414	free_area_init_core(pgdat, zones_size, zholes_size);
 
4415}
4416
4417#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4418
4419#if MAX_NUMNODES > 1
4420/*
4421 * Figure out the number of possible node ids.
4422 */
4423static void __init setup_nr_node_ids(void)
4424{
4425	unsigned int node;
4426	unsigned int highest = 0;
4427
4428	for_each_node_mask(node, node_possible_map)
4429		highest = node;
4430	nr_node_ids = highest + 1;
4431}
4432#else
4433static inline void setup_nr_node_ids(void)
4434{
4435}
4436#endif
4437
4438/**
4439 * add_active_range - Register a range of PFNs backed by physical memory
4440 * @nid: The node ID the range resides on
4441 * @start_pfn: The start PFN of the available physical memory
4442 * @end_pfn: The end PFN of the available physical memory
4443 *
4444 * These ranges are stored in an early_node_map[] and later used by
4445 * free_area_init_nodes() to calculate zone sizes and holes. If the
4446 * range spans a memory hole, it is up to the architecture to ensure
4447 * the memory is not freed by the bootmem allocator. If possible
4448 * the range being registered will be merged with existing ranges.
4449 */
4450void __init add_active_range(unsigned int nid, unsigned long start_pfn,
4451						unsigned long end_pfn)
4452{
4453	int i;
4454
4455	mminit_dprintk(MMINIT_TRACE, "memory_register",
4456			"Entering add_active_range(%d, %#lx, %#lx) "
4457			"%d entries of %d used\n",
4458			nid, start_pfn, end_pfn,
4459			nr_nodemap_entries, MAX_ACTIVE_REGIONS);
4460
4461	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
4462
4463	/* Merge with existing active regions if possible */
4464	for (i = 0; i < nr_nodemap_entries; i++) {
4465		if (early_node_map[i].nid != nid)
4466			continue;
4467
4468		/* Skip if an existing region covers this new one */
4469		if (start_pfn >= early_node_map[i].start_pfn &&
4470				end_pfn <= early_node_map[i].end_pfn)
4471			return;
4472
4473		/* Merge forward if suitable */
4474		if (start_pfn <= early_node_map[i].end_pfn &&
4475				end_pfn > early_node_map[i].end_pfn) {
4476			early_node_map[i].end_pfn = end_pfn;
4477			return;
4478		}
4479
4480		/* Merge backward if suitable */
4481		if (start_pfn < early_node_map[i].start_pfn &&
4482				end_pfn >= early_node_map[i].start_pfn) {
4483			early_node_map[i].start_pfn = start_pfn;
4484			return;
4485		}
4486	}
4487
4488	/* Check that early_node_map is large enough */
4489	if (i >= MAX_ACTIVE_REGIONS) {
4490		printk(KERN_CRIT "More than %d memory regions, truncating\n",
4491							MAX_ACTIVE_REGIONS);
4492		return;
4493	}
4494
4495	early_node_map[i].nid = nid;
4496	early_node_map[i].start_pfn = start_pfn;
4497	early_node_map[i].end_pfn = end_pfn;
4498	nr_nodemap_entries = i + 1;
4499}
4500
4501/**
4502 * remove_active_range - Shrink an existing registered range of PFNs
4503 * @nid: The node id the range is on that should be shrunk
4504 * @start_pfn: The new PFN of the range
4505 * @end_pfn: The new PFN of the range
4506 *
4507 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4508 * The map is kept near the end physical page range that has already been
4509 * registered. This function allows an arch to shrink an existing registered
4510 * range.
4511 */
4512void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
4513				unsigned long end_pfn)
4514{
4515	int i, j;
4516	int removed = 0;
4517
4518	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
4519			  nid, start_pfn, end_pfn);
4520
4521	/* Find the old active region end and shrink */
4522	for_each_active_range_index_in_nid(i, nid) {
4523		if (early_node_map[i].start_pfn >= start_pfn &&
4524		    early_node_map[i].end_pfn <= end_pfn) {
4525			/* clear it */
4526			early_node_map[i].start_pfn = 0;
4527			early_node_map[i].end_pfn = 0;
4528			removed = 1;
4529			continue;
4530		}
4531		if (early_node_map[i].start_pfn < start_pfn &&
4532		    early_node_map[i].end_pfn > start_pfn) {
4533			unsigned long temp_end_pfn = early_node_map[i].end_pfn;
4534			early_node_map[i].end_pfn = start_pfn;
4535			if (temp_end_pfn > end_pfn)
4536				add_active_range(nid, end_pfn, temp_end_pfn);
4537			continue;
4538		}
4539		if (early_node_map[i].start_pfn >= start_pfn &&
4540		    early_node_map[i].end_pfn > end_pfn &&
4541		    early_node_map[i].start_pfn < end_pfn) {
4542			early_node_map[i].start_pfn = end_pfn;
4543			continue;
4544		}
4545	}
4546
4547	if (!removed)
4548		return;
4549
4550	/* remove the blank ones */
4551	for (i = nr_nodemap_entries - 1; i > 0; i--) {
4552		if (early_node_map[i].nid != nid)
4553			continue;
4554		if (early_node_map[i].end_pfn)
4555			continue;
4556		/* we found it, get rid of it */
4557		for (j = i; j < nr_nodemap_entries - 1; j++)
4558			memcpy(&early_node_map[j], &early_node_map[j+1],
4559				sizeof(early_node_map[j]));
4560		j = nr_nodemap_entries - 1;
4561		memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
4562		nr_nodemap_entries--;
4563	}
4564}
4565
4566/**
4567 * remove_all_active_ranges - Remove all currently registered regions
4568 *
4569 * During discovery, it may be found that a table like SRAT is invalid
4570 * and an alternative discovery method must be used. This function removes
4571 * all currently registered regions.
4572 */
4573void __init remove_all_active_ranges(void)
4574{
4575	memset(early_node_map, 0, sizeof(early_node_map));
4576	nr_nodemap_entries = 0;
4577}
4578
4579/* Compare two active node_active_regions */
4580static int __init cmp_node_active_region(const void *a, const void *b)
4581{
4582	struct node_active_region *arange = (struct node_active_region *)a;
4583	struct node_active_region *brange = (struct node_active_region *)b;
4584
4585	/* Done this way to avoid overflows */
4586	if (arange->start_pfn > brange->start_pfn)
4587		return 1;
4588	if (arange->start_pfn < brange->start_pfn)
4589		return -1;
4590
4591	return 0;
4592}
4593
4594/* sort the node_map by start_pfn */
4595void __init sort_node_map(void)
4596{
4597	sort(early_node_map, (size_t)nr_nodemap_entries,
4598			sizeof(struct node_active_region),
4599			cmp_node_active_region, NULL);
4600}
4601
4602/**
4603 * node_map_pfn_alignment - determine the maximum internode alignment
4604 *
4605 * This function should be called after node map is populated and sorted.
4606 * It calculates the maximum power of two alignment which can distinguish
4607 * all the nodes.
4608 *
4609 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4610 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)).  If the
4611 * nodes are shifted by 256MiB, 256MiB.  Note that if only the last node is
4612 * shifted, 1GiB is enough and this function will indicate so.
4613 *
4614 * This is used to test whether pfn -> nid mapping of the chosen memory
4615 * model has fine enough granularity to avoid incorrect mapping for the
4616 * populated node map.
4617 *
4618 * Returns the determined alignment in pfn's.  0 if there is no alignment
4619 * requirement (single node).
4620 */
4621unsigned long __init node_map_pfn_alignment(void)
4622{
4623	unsigned long accl_mask = 0, last_end = 0;
 
4624	int last_nid = -1;
4625	int i;
4626
4627	for_each_active_range_index_in_nid(i, MAX_NUMNODES) {
4628		int nid = early_node_map[i].nid;
4629		unsigned long start = early_node_map[i].start_pfn;
4630		unsigned long end = early_node_map[i].end_pfn;
4631		unsigned long mask;
4632
 
4633		if (!start || last_nid < 0 || last_nid == nid) {
4634			last_nid = nid;
4635			last_end = end;
4636			continue;
4637		}
4638
4639		/*
4640		 * Start with a mask granular enough to pin-point to the
4641		 * start pfn and tick off bits one-by-one until it becomes
4642		 * too coarse to separate the current node from the last.
4643		 */
4644		mask = ~((1 << __ffs(start)) - 1);
4645		while (mask && last_end <= (start & (mask << 1)))
4646			mask <<= 1;
4647
4648		/* accumulate all internode masks */
4649		accl_mask |= mask;
4650	}
4651
4652	/* convert mask to number of pages */
4653	return ~accl_mask + 1;
4654}
4655
4656/* Find the lowest pfn for a node */
4657static unsigned long __init find_min_pfn_for_node(int nid)
4658{
4659	int i;
4660	unsigned long min_pfn = ULONG_MAX;
 
 
4661
4662	/* Assuming a sorted map, the first range found has the starting pfn */
4663	for_each_active_range_index_in_nid(i, nid)
4664		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4665
4666	if (min_pfn == ULONG_MAX) {
4667		printk(KERN_WARNING
4668			"Could not find start_pfn for node %d\n", nid);
4669		return 0;
4670	}
4671
4672	return min_pfn;
4673}
4674
4675/**
4676 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4677 *
4678 * It returns the minimum PFN based on information provided via
4679 * add_active_range().
4680 */
4681unsigned long __init find_min_pfn_with_active_regions(void)
4682{
4683	return find_min_pfn_for_node(MAX_NUMNODES);
4684}
4685
4686/*
4687 * early_calculate_totalpages()
4688 * Sum pages in active regions for movable zone.
4689 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4690 */
4691static unsigned long __init early_calculate_totalpages(void)
4692{
4693	int i;
4694	unsigned long totalpages = 0;
 
 
 
 
 
4695
4696	for (i = 0; i < nr_nodemap_entries; i++) {
4697		unsigned long pages = early_node_map[i].end_pfn -
4698						early_node_map[i].start_pfn;
4699		totalpages += pages;
4700		if (pages)
4701			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
4702	}
4703  	return totalpages;
4704}
4705
4706/*
4707 * Find the PFN the Movable zone begins in each node. Kernel memory
4708 * is spread evenly between nodes as long as the nodes have enough
4709 * memory. When they don't, some nodes will have more kernelcore than
4710 * others
4711 */
4712static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
4713{
4714	int i, nid;
4715	unsigned long usable_startpfn;
4716	unsigned long kernelcore_node, kernelcore_remaining;
4717	/* save the state before borrow the nodemask */
4718	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4719	unsigned long totalpages = early_calculate_totalpages();
4720	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4721
4722	/*
4723	 * If movablecore was specified, calculate what size of
4724	 * kernelcore that corresponds so that memory usable for
4725	 * any allocation type is evenly spread. If both kernelcore
4726	 * and movablecore are specified, then the value of kernelcore
4727	 * will be used for required_kernelcore if it's greater than
4728	 * what movablecore would have allowed.
4729	 */
4730	if (required_movablecore) {
4731		unsigned long corepages;
4732
4733		/*
4734		 * Round-up so that ZONE_MOVABLE is at least as large as what
4735		 * was requested by the user
4736		 */
4737		required_movablecore =
4738			roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4739		corepages = totalpages - required_movablecore;
4740
4741		required_kernelcore = max(required_kernelcore, corepages);
4742	}
4743
4744	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
4745	if (!required_kernelcore)
4746		goto out;
4747
4748	/* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4749	find_usable_zone_for_movable();
4750	usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4751
4752restart:
4753	/* Spread kernelcore memory as evenly as possible throughout nodes */
4754	kernelcore_node = required_kernelcore / usable_nodes;
4755	for_each_node_state(nid, N_HIGH_MEMORY) {
 
 
4756		/*
4757		 * Recalculate kernelcore_node if the division per node
4758		 * now exceeds what is necessary to satisfy the requested
4759		 * amount of memory for the kernel
4760		 */
4761		if (required_kernelcore < kernelcore_node)
4762			kernelcore_node = required_kernelcore / usable_nodes;
4763
4764		/*
4765		 * As the map is walked, we track how much memory is usable
4766		 * by the kernel using kernelcore_remaining. When it is
4767		 * 0, the rest of the node is usable by ZONE_MOVABLE
4768		 */
4769		kernelcore_remaining = kernelcore_node;
4770
4771		/* Go through each range of PFNs within this node */
4772		for_each_active_range_index_in_nid(i, nid) {
4773			unsigned long start_pfn, end_pfn;
4774			unsigned long size_pages;
4775
4776			start_pfn = max(early_node_map[i].start_pfn,
4777						zone_movable_pfn[nid]);
4778			end_pfn = early_node_map[i].end_pfn;
4779			if (start_pfn >= end_pfn)
4780				continue;
4781
4782			/* Account for what is only usable for kernelcore */
4783			if (start_pfn < usable_startpfn) {
4784				unsigned long kernel_pages;
4785				kernel_pages = min(end_pfn, usable_startpfn)
4786								- start_pfn;
4787
4788				kernelcore_remaining -= min(kernel_pages,
4789							kernelcore_remaining);
4790				required_kernelcore -= min(kernel_pages,
4791							required_kernelcore);
4792
4793				/* Continue if range is now fully accounted */
4794				if (end_pfn <= usable_startpfn) {
4795
4796					/*
4797					 * Push zone_movable_pfn to the end so
4798					 * that if we have to rebalance
4799					 * kernelcore across nodes, we will
4800					 * not double account here
4801					 */
4802					zone_movable_pfn[nid] = end_pfn;
4803					continue;
4804				}
4805				start_pfn = usable_startpfn;
4806			}
4807
4808			/*
4809			 * The usable PFN range for ZONE_MOVABLE is from
4810			 * start_pfn->end_pfn. Calculate size_pages as the
4811			 * number of pages used as kernelcore
4812			 */
4813			size_pages = end_pfn - start_pfn;
4814			if (size_pages > kernelcore_remaining)
4815				size_pages = kernelcore_remaining;
4816			zone_movable_pfn[nid] = start_pfn + size_pages;
4817
4818			/*
4819			 * Some kernelcore has been met, update counts and
4820			 * break if the kernelcore for this node has been
4821			 * satisified
4822			 */
4823			required_kernelcore -= min(required_kernelcore,
4824								size_pages);
4825			kernelcore_remaining -= size_pages;
4826			if (!kernelcore_remaining)
4827				break;
4828		}
4829	}
4830
4831	/*
4832	 * If there is still required_kernelcore, we do another pass with one
4833	 * less node in the count. This will push zone_movable_pfn[nid] further
4834	 * along on the nodes that still have memory until kernelcore is
4835	 * satisified
4836	 */
4837	usable_nodes--;
4838	if (usable_nodes && required_kernelcore > usable_nodes)
4839		goto restart;
4840
 
4841	/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4842	for (nid = 0; nid < MAX_NUMNODES; nid++)
4843		zone_movable_pfn[nid] =
4844			roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4845
4846out:
4847	/* restore the node_state */
4848	node_states[N_HIGH_MEMORY] = saved_node_state;
4849}
4850
4851/* Any regular memory on that node ? */
4852static void check_for_regular_memory(pg_data_t *pgdat)
4853{
4854#ifdef CONFIG_HIGHMEM
4855	enum zone_type zone_type;
4856
4857	for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
 
 
 
4858		struct zone *zone = &pgdat->node_zones[zone_type];
4859		if (zone->present_pages)
4860			node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
 
 
 
 
 
4861	}
4862#endif
4863}
4864
4865/**
4866 * free_area_init_nodes - Initialise all pg_data_t and zone data
4867 * @max_zone_pfn: an array of max PFNs for each zone
4868 *
4869 * This will call free_area_init_node() for each active node in the system.
4870 * Using the page ranges provided by add_active_range(), the size of each
4871 * zone in each node and their holes is calculated. If the maximum PFN
4872 * between two adjacent zones match, it is assumed that the zone is empty.
4873 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4874 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4875 * starts where the previous one ended. For example, ZONE_DMA32 starts
4876 * at arch_max_dma_pfn.
4877 */
4878void __init free_area_init_nodes(unsigned long *max_zone_pfn)
4879{
4880	unsigned long nid;
4881	int i;
4882
4883	/* Sort early_node_map as initialisation assumes it is sorted */
4884	sort_node_map();
4885
4886	/* Record where the zone boundaries are */
4887	memset(arch_zone_lowest_possible_pfn, 0,
4888				sizeof(arch_zone_lowest_possible_pfn));
4889	memset(arch_zone_highest_possible_pfn, 0,
4890				sizeof(arch_zone_highest_possible_pfn));
4891	arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
4892	arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
4893	for (i = 1; i < MAX_NR_ZONES; i++) {
4894		if (i == ZONE_MOVABLE)
4895			continue;
4896		arch_zone_lowest_possible_pfn[i] =
4897			arch_zone_highest_possible_pfn[i-1];
4898		arch_zone_highest_possible_pfn[i] =
4899			max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
4900	}
4901	arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
4902	arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
4903
4904	/* Find the PFNs that ZONE_MOVABLE begins at in each node */
4905	memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
4906	find_zone_movable_pfns_for_nodes(zone_movable_pfn);
4907
4908	/* Print out the zone ranges */
4909	printk("Zone PFN ranges:\n");
4910	for (i = 0; i < MAX_NR_ZONES; i++) {
4911		if (i == ZONE_MOVABLE)
4912			continue;
4913		printk("  %-8s ", zone_names[i]);
4914		if (arch_zone_lowest_possible_pfn[i] ==
4915				arch_zone_highest_possible_pfn[i])
4916			printk("empty\n");
4917		else
4918			printk("%0#10lx -> %0#10lx\n",
4919				arch_zone_lowest_possible_pfn[i],
4920				arch_zone_highest_possible_pfn[i]);
 
4921	}
4922
4923	/* Print out the PFNs ZONE_MOVABLE begins at in each node */
4924	printk("Movable zone start PFN for each node\n");
4925	for (i = 0; i < MAX_NUMNODES; i++) {
4926		if (zone_movable_pfn[i])
4927			printk("  Node %d: %lu\n", i, zone_movable_pfn[i]);
 
4928	}
4929
4930	/* Print out the early_node_map[] */
4931	printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
4932	for (i = 0; i < nr_nodemap_entries; i++)
4933		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4934						early_node_map[i].start_pfn,
4935						early_node_map[i].end_pfn);
4936
4937	/* Initialise every node */
4938	mminit_verify_pageflags_layout();
4939	setup_nr_node_ids();
4940	for_each_online_node(nid) {
4941		pg_data_t *pgdat = NODE_DATA(nid);
4942		free_area_init_node(nid, NULL,
4943				find_min_pfn_for_node(nid), NULL);
4944
4945		/* Any memory on that node */
4946		if (pgdat->node_present_pages)
4947			node_set_state(nid, N_HIGH_MEMORY);
4948		check_for_regular_memory(pgdat);
4949	}
4950}
4951
4952static int __init cmdline_parse_core(char *p, unsigned long *core)
4953{
4954	unsigned long long coremem;
4955	if (!p)
4956		return -EINVAL;
4957
4958	coremem = memparse(p, &p);
4959	*core = coremem >> PAGE_SHIFT;
4960
4961	/* Paranoid check that UL is enough for the coremem value */
4962	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
4963
4964	return 0;
4965}
4966
4967/*
4968 * kernelcore=size sets the amount of memory for use for allocations that
4969 * cannot be reclaimed or migrated.
4970 */
4971static int __init cmdline_parse_kernelcore(char *p)
4972{
4973	return cmdline_parse_core(p, &required_kernelcore);
4974}
4975
4976/*
4977 * movablecore=size sets the amount of memory for use for allocations that
4978 * can be reclaimed or migrated.
4979 */
4980static int __init cmdline_parse_movablecore(char *p)
4981{
4982	return cmdline_parse_core(p, &required_movablecore);
4983}
4984
4985early_param("kernelcore", cmdline_parse_kernelcore);
4986early_param("movablecore", cmdline_parse_movablecore);
4987
4988#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4989
4990/**
4991 * set_dma_reserve - set the specified number of pages reserved in the first zone
4992 * @new_dma_reserve: The number of pages to mark reserved
4993 *
4994 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4995 * In the DMA zone, a significant percentage may be consumed by kernel image
4996 * and other unfreeable allocations which can skew the watermarks badly. This
4997 * function may optionally be used to account for unfreeable pages in the
4998 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4999 * smaller per-cpu batchsize.
5000 */
5001void __init set_dma_reserve(unsigned long new_dma_reserve)
5002{
5003	dma_reserve = new_dma_reserve;
5004}
5005
5006void __init free_area_init(unsigned long *zones_size)
5007{
5008	free_area_init_node(0, zones_size,
5009			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5010}
5011
5012static int page_alloc_cpu_notify(struct notifier_block *self,
5013				 unsigned long action, void *hcpu)
5014{
5015	int cpu = (unsigned long)hcpu;
5016
5017	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
 
5018		drain_pages(cpu);
5019
5020		/*
5021		 * Spill the event counters of the dead processor
5022		 * into the current processors event counters.
5023		 * This artificially elevates the count of the current
5024		 * processor.
5025		 */
5026		vm_events_fold_cpu(cpu);
5027
5028		/*
5029		 * Zero the differential counters of the dead processor
5030		 * so that the vm statistics are consistent.
5031		 *
5032		 * This is only okay since the processor is dead and cannot
5033		 * race with what we are doing.
5034		 */
5035		refresh_cpu_vm_stats(cpu);
5036	}
5037	return NOTIFY_OK;
5038}
5039
5040void __init page_alloc_init(void)
5041{
5042	hotcpu_notifier(page_alloc_cpu_notify, 0);
5043}
5044
5045/*
5046 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5047 *	or min_free_kbytes changes.
5048 */
5049static void calculate_totalreserve_pages(void)
5050{
5051	struct pglist_data *pgdat;
5052	unsigned long reserve_pages = 0;
5053	enum zone_type i, j;
5054
5055	for_each_online_pgdat(pgdat) {
5056		for (i = 0; i < MAX_NR_ZONES; i++) {
5057			struct zone *zone = pgdat->node_zones + i;
5058			unsigned long max = 0;
5059
5060			/* Find valid and maximum lowmem_reserve in the zone */
5061			for (j = i; j < MAX_NR_ZONES; j++) {
5062				if (zone->lowmem_reserve[j] > max)
5063					max = zone->lowmem_reserve[j];
5064			}
5065
5066			/* we treat the high watermark as reserved pages. */
5067			max += high_wmark_pages(zone);
5068
5069			if (max > zone->present_pages)
5070				max = zone->present_pages;
5071			reserve_pages += max;
 
 
 
 
 
 
 
 
 
 
5072		}
5073	}
 
5074	totalreserve_pages = reserve_pages;
5075}
5076
5077/*
5078 * setup_per_zone_lowmem_reserve - called whenever
5079 *	sysctl_lower_zone_reserve_ratio changes.  Ensures that each zone
5080 *	has a correct pages reserved value, so an adequate number of
5081 *	pages are left in the zone after a successful __alloc_pages().
5082 */
5083static void setup_per_zone_lowmem_reserve(void)
5084{
5085	struct pglist_data *pgdat;
5086	enum zone_type j, idx;
5087
5088	for_each_online_pgdat(pgdat) {
5089		for (j = 0; j < MAX_NR_ZONES; j++) {
5090			struct zone *zone = pgdat->node_zones + j;
5091			unsigned long present_pages = zone->present_pages;
5092
5093			zone->lowmem_reserve[j] = 0;
5094
5095			idx = j;
5096			while (idx) {
5097				struct zone *lower_zone;
5098
5099				idx--;
5100
5101				if (sysctl_lowmem_reserve_ratio[idx] < 1)
5102					sysctl_lowmem_reserve_ratio[idx] = 1;
5103
5104				lower_zone = pgdat->node_zones + idx;
5105				lower_zone->lowmem_reserve[j] = present_pages /
5106					sysctl_lowmem_reserve_ratio[idx];
5107				present_pages += lower_zone->present_pages;
5108			}
5109		}
5110	}
5111
5112	/* update totalreserve_pages */
5113	calculate_totalreserve_pages();
5114}
5115
5116/**
5117 * setup_per_zone_wmarks - called when min_free_kbytes changes
5118 * or when memory is hot-{added|removed}
5119 *
5120 * Ensures that the watermark[min,low,high] values for each zone are set
5121 * correctly with respect to min_free_kbytes.
5122 */
5123void setup_per_zone_wmarks(void)
5124{
5125	unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5126	unsigned long lowmem_pages = 0;
5127	struct zone *zone;
5128	unsigned long flags;
5129
5130	/* Calculate total number of !ZONE_HIGHMEM pages */
5131	for_each_zone(zone) {
5132		if (!is_highmem(zone))
5133			lowmem_pages += zone->present_pages;
5134	}
5135
5136	for_each_zone(zone) {
5137		u64 tmp;
5138
5139		spin_lock_irqsave(&zone->lock, flags);
5140		tmp = (u64)pages_min * zone->present_pages;
5141		do_div(tmp, lowmem_pages);
5142		if (is_highmem(zone)) {
5143			/*
5144			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5145			 * need highmem pages, so cap pages_min to a small
5146			 * value here.
5147			 *
5148			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5149			 * deltas controls asynch page reclaim, and so should
5150			 * not be capped for highmem.
5151			 */
5152			int min_pages;
5153
5154			min_pages = zone->present_pages / 1024;
5155			if (min_pages < SWAP_CLUSTER_MAX)
5156				min_pages = SWAP_CLUSTER_MAX;
5157			if (min_pages > 128)
5158				min_pages = 128;
5159			zone->watermark[WMARK_MIN] = min_pages;
5160		} else {
5161			/*
5162			 * If it's a lowmem zone, reserve a number of pages
5163			 * proportionate to the zone's size.
5164			 */
5165			zone->watermark[WMARK_MIN] = tmp;
5166		}
5167
5168		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
5169		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
 
 
 
 
 
 
5170		setup_zone_migrate_reserve(zone);
5171		spin_unlock_irqrestore(&zone->lock, flags);
5172	}
5173
5174	/* update totalreserve_pages */
5175	calculate_totalreserve_pages();
5176}
5177
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5178/*
5179 * The inactive anon list should be small enough that the VM never has to
5180 * do too much work, but large enough that each inactive page has a chance
5181 * to be referenced again before it is swapped out.
5182 *
5183 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5184 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5185 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5186 * the anonymous pages are kept on the inactive list.
5187 *
5188 * total     target    max
5189 * memory    ratio     inactive anon
5190 * -------------------------------------
5191 *   10MB       1         5MB
5192 *  100MB       1        50MB
5193 *    1GB       3       250MB
5194 *   10GB      10       0.9GB
5195 *  100GB      31         3GB
5196 *    1TB     101        10GB
5197 *   10TB     320        32GB
5198 */
5199static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5200{
5201	unsigned int gb, ratio;
5202
5203	/* Zone size in gigabytes */
5204	gb = zone->present_pages >> (30 - PAGE_SHIFT);
5205	if (gb)
5206		ratio = int_sqrt(10 * gb);
5207	else
5208		ratio = 1;
5209
5210	zone->inactive_ratio = ratio;
5211}
5212
5213static void __meminit setup_per_zone_inactive_ratio(void)
5214{
5215	struct zone *zone;
5216
5217	for_each_zone(zone)
5218		calculate_zone_inactive_ratio(zone);
5219}
5220
5221/*
5222 * Initialise min_free_kbytes.
5223 *
5224 * For small machines we want it small (128k min).  For large machines
5225 * we want it large (64MB max).  But it is not linear, because network
5226 * bandwidth does not increase linearly with machine size.  We use
5227 *
5228 * 	min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5229 *	min_free_kbytes = sqrt(lowmem_kbytes * 16)
5230 *
5231 * which yields
5232 *
5233 * 16MB:	512k
5234 * 32MB:	724k
5235 * 64MB:	1024k
5236 * 128MB:	1448k
5237 * 256MB:	2048k
5238 * 512MB:	2896k
5239 * 1024MB:	4096k
5240 * 2048MB:	5792k
5241 * 4096MB:	8192k
5242 * 8192MB:	11584k
5243 * 16384MB:	16384k
5244 */
5245int __meminit init_per_zone_wmark_min(void)
5246{
5247	unsigned long lowmem_kbytes;
 
5248
5249	lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
 
5250
5251	min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5252	if (min_free_kbytes < 128)
5253		min_free_kbytes = 128;
5254	if (min_free_kbytes > 65536)
5255		min_free_kbytes = 65536;
 
 
 
 
 
5256	setup_per_zone_wmarks();
5257	refresh_zone_stat_thresholds();
5258	setup_per_zone_lowmem_reserve();
5259	setup_per_zone_inactive_ratio();
5260	return 0;
5261}
5262module_init(init_per_zone_wmark_min)
5263
5264/*
5265 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 
5266 *	that we can call two helper functions whenever min_free_kbytes
5267 *	changes.
5268 */
5269int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
5270	void __user *buffer, size_t *length, loff_t *ppos)
5271{
5272	proc_dointvec(table, write, buffer, length, ppos);
5273	if (write)
 
 
 
 
 
 
5274		setup_per_zone_wmarks();
 
5275	return 0;
5276}
5277
5278#ifdef CONFIG_NUMA
5279int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5280	void __user *buffer, size_t *length, loff_t *ppos)
5281{
5282	struct zone *zone;
5283	int rc;
5284
5285	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5286	if (rc)
5287		return rc;
5288
5289	for_each_zone(zone)
5290		zone->min_unmapped_pages = (zone->present_pages *
5291				sysctl_min_unmapped_ratio) / 100;
5292	return 0;
5293}
5294
5295int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5296	void __user *buffer, size_t *length, loff_t *ppos)
5297{
5298	struct zone *zone;
5299	int rc;
5300
5301	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5302	if (rc)
5303		return rc;
5304
5305	for_each_zone(zone)
5306		zone->min_slab_pages = (zone->present_pages *
5307				sysctl_min_slab_ratio) / 100;
5308	return 0;
5309}
5310#endif
5311
5312/*
5313 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5314 *	proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5315 *	whenever sysctl_lowmem_reserve_ratio changes.
5316 *
5317 * The reserve ratio obviously has absolutely no relation with the
5318 * minimum watermarks. The lowmem reserve ratio can only make sense
5319 * if in function of the boot time zone sizes.
5320 */
5321int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5322	void __user *buffer, size_t *length, loff_t *ppos)
5323{
5324	proc_dointvec_minmax(table, write, buffer, length, ppos);
5325	setup_per_zone_lowmem_reserve();
5326	return 0;
5327}
5328
5329/*
5330 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5331 * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
5332 * can have before it gets flushed back to buddy allocator.
5333 */
5334
5335int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
5336	void __user *buffer, size_t *length, loff_t *ppos)
5337{
5338	struct zone *zone;
5339	unsigned int cpu;
5340	int ret;
5341
5342	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5343	if (!write || (ret == -EINVAL))
5344		return ret;
 
 
5345	for_each_populated_zone(zone) {
5346		for_each_possible_cpu(cpu) {
5347			unsigned long  high;
5348			high = zone->present_pages / percpu_pagelist_fraction;
5349			setup_pagelist_highmark(
5350				per_cpu_ptr(zone->pageset, cpu), high);
5351		}
5352	}
 
5353	return 0;
5354}
5355
5356int hashdist = HASHDIST_DEFAULT;
5357
5358#ifdef CONFIG_NUMA
5359static int __init set_hashdist(char *str)
5360{
5361	if (!str)
5362		return 0;
5363	hashdist = simple_strtoul(str, &str, 0);
5364	return 1;
5365}
5366__setup("hashdist=", set_hashdist);
5367#endif
5368
5369/*
5370 * allocate a large system hash table from bootmem
5371 * - it is assumed that the hash table must contain an exact power-of-2
5372 *   quantity of entries
5373 * - limit is the number of hash buckets, not the total allocation size
5374 */
5375void *__init alloc_large_system_hash(const char *tablename,
5376				     unsigned long bucketsize,
5377				     unsigned long numentries,
5378				     int scale,
5379				     int flags,
5380				     unsigned int *_hash_shift,
5381				     unsigned int *_hash_mask,
5382				     unsigned long limit)
 
5383{
5384	unsigned long long max = limit;
5385	unsigned long log2qty, size;
5386	void *table = NULL;
5387
5388	/* allow the kernel cmdline to have a say */
5389	if (!numentries) {
5390		/* round applicable memory size up to nearest megabyte */
5391		numentries = nr_kernel_pages;
5392		numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
5393		numentries >>= 20 - PAGE_SHIFT;
5394		numentries <<= 20 - PAGE_SHIFT;
 
5395
5396		/* limit to 1 bucket per 2^scale bytes of low memory */
5397		if (scale > PAGE_SHIFT)
5398			numentries >>= (scale - PAGE_SHIFT);
5399		else
5400			numentries <<= (PAGE_SHIFT - scale);
5401
5402		/* Make sure we've got at least a 0-order allocation.. */
5403		if (unlikely(flags & HASH_SMALL)) {
5404			/* Makes no sense without HASH_EARLY */
5405			WARN_ON(!(flags & HASH_EARLY));
5406			if (!(numentries >> *_hash_shift)) {
5407				numentries = 1UL << *_hash_shift;
5408				BUG_ON(!numentries);
5409			}
5410		} else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5411			numentries = PAGE_SIZE / bucketsize;
5412	}
5413	numentries = roundup_pow_of_two(numentries);
5414
5415	/* limit allocation size to 1/16 total memory by default */
5416	if (max == 0) {
5417		max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5418		do_div(max, bucketsize);
5419	}
 
5420
 
 
5421	if (numentries > max)
5422		numentries = max;
5423
5424	log2qty = ilog2(numentries);
5425
5426	do {
5427		size = bucketsize << log2qty;
5428		if (flags & HASH_EARLY)
5429			table = alloc_bootmem_nopanic(size);
5430		else if (hashdist)
5431			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
5432		else {
5433			/*
5434			 * If bucketsize is not a power-of-two, we may free
5435			 * some pages at the end of hash table which
5436			 * alloc_pages_exact() automatically does
5437			 */
5438			if (get_order(size) < MAX_ORDER) {
5439				table = alloc_pages_exact(size, GFP_ATOMIC);
5440				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
5441			}
5442		}
5443	} while (!table && size > PAGE_SIZE && --log2qty);
5444
5445	if (!table)
5446		panic("Failed to allocate %s hash table\n", tablename);
5447
5448	printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
5449	       tablename,
5450	       (1UL << log2qty),
5451	       ilog2(size) - PAGE_SHIFT,
5452	       size);
5453
5454	if (_hash_shift)
5455		*_hash_shift = log2qty;
5456	if (_hash_mask)
5457		*_hash_mask = (1 << log2qty) - 1;
5458
5459	return table;
5460}
5461
5462/* Return a pointer to the bitmap storing bits affecting a block of pages */
5463static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
5464							unsigned long pfn)
5465{
5466#ifdef CONFIG_SPARSEMEM
5467	return __pfn_to_section(pfn)->pageblock_flags;
5468#else
5469	return zone->pageblock_flags;
5470#endif /* CONFIG_SPARSEMEM */
5471}
5472
5473static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
5474{
5475#ifdef CONFIG_SPARSEMEM
5476	pfn &= (PAGES_PER_SECTION-1);
5477	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5478#else
5479	pfn = pfn - zone->zone_start_pfn;
5480	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5481#endif /* CONFIG_SPARSEMEM */
5482}
5483
5484/**
5485 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5486 * @page: The page within the block of interest
5487 * @start_bitidx: The first bit of interest to retrieve
5488 * @end_bitidx: The last bit of interest
5489 * returns pageblock_bits flags
5490 */
5491unsigned long get_pageblock_flags_group(struct page *page,
5492					int start_bitidx, int end_bitidx)
5493{
5494	struct zone *zone;
5495	unsigned long *bitmap;
5496	unsigned long pfn, bitidx;
5497	unsigned long flags = 0;
5498	unsigned long value = 1;
5499
5500	zone = page_zone(page);
5501	pfn = page_to_pfn(page);
5502	bitmap = get_pageblock_bitmap(zone, pfn);
5503	bitidx = pfn_to_bitidx(zone, pfn);
5504
5505	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5506		if (test_bit(bitidx + start_bitidx, bitmap))
5507			flags |= value;
5508
5509	return flags;
5510}
5511
5512/**
5513 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5514 * @page: The page within the block of interest
5515 * @start_bitidx: The first bit of interest
5516 * @end_bitidx: The last bit of interest
5517 * @flags: The flags to set
5518 */
5519void set_pageblock_flags_group(struct page *page, unsigned long flags,
5520					int start_bitidx, int end_bitidx)
5521{
5522	struct zone *zone;
5523	unsigned long *bitmap;
5524	unsigned long pfn, bitidx;
5525	unsigned long value = 1;
5526
5527	zone = page_zone(page);
5528	pfn = page_to_pfn(page);
5529	bitmap = get_pageblock_bitmap(zone, pfn);
5530	bitidx = pfn_to_bitidx(zone, pfn);
5531	VM_BUG_ON(pfn < zone->zone_start_pfn);
5532	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5533
5534	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5535		if (flags & value)
5536			__set_bit(bitidx + start_bitidx, bitmap);
5537		else
5538			__clear_bit(bitidx + start_bitidx, bitmap);
5539}
5540
5541/*
5542 * This is designed as sub function...plz see page_isolation.c also.
5543 * set/clear page block's type to be ISOLATE.
5544 * page allocater never alloc memory from ISOLATE block.
 
 
 
5545 */
5546
5547static int
5548__count_immobile_pages(struct zone *zone, struct page *page, int count)
5549{
5550	unsigned long pfn, iter, found;
 
 
5551	/*
5552	 * For avoiding noise data, lru_add_drain_all() should be called
5553	 * If ZONE_MOVABLE, the zone never contains immobile pages
5554	 */
5555	if (zone_idx(zone) == ZONE_MOVABLE)
5556		return true;
5557
5558	if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
5559		return true;
5560
5561	pfn = page_to_pfn(page);
5562	for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
5563		unsigned long check = pfn + iter;
5564
5565		if (!pfn_valid_within(check))
5566			continue;
5567
5568		page = pfn_to_page(check);
5569		if (!page_count(page)) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5570			if (PageBuddy(page))
5571				iter += (1 << page_order(page)) - 1;
5572			continue;
5573		}
 
 
 
 
 
 
 
 
5574		if (!PageLRU(page))
5575			found++;
5576		/*
5577		 * If there are RECLAIMABLE pages, we need to check it.
5578		 * But now, memory offline itself doesn't call shrink_slab()
5579		 * and it still to be fixed.
5580		 */
5581		/*
5582		 * If the page is not RAM, page_count()should be 0.
5583		 * we don't need more check. This is an _used_ not-movable page.
5584		 *
5585		 * The problematic thing here is PG_reserved pages. PG_reserved
5586		 * is set to both of a memory hole page and a _used_ kernel
5587		 * page at boot.
5588		 */
5589		if (found > count)
5590			return false;
5591	}
5592	return true;
5593}
5594
5595bool is_pageblock_removable_nolock(struct page *page)
5596{
5597	struct zone *zone = page_zone(page);
5598	return __count_immobile_pages(zone, page, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5599}
5600
5601int set_migratetype_isolate(struct page *page)
 
 
5602{
5603	struct zone *zone;
5604	unsigned long flags, pfn;
5605	struct memory_isolate_notify arg;
5606	int notifier_ret;
5607	int ret = -EBUSY;
5608
5609	zone = page_zone(page);
 
 
 
 
5610
5611	spin_lock_irqsave(&zone->lock, flags);
 
 
 
 
 
 
 
 
5612
5613	pfn = page_to_pfn(page);
5614	arg.start_pfn = pfn;
5615	arg.nr_pages = pageblock_nr_pages;
5616	arg.pages_found = 0;
5617
5618	/*
5619	 * It may be possible to isolate a pageblock even if the
5620	 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5621	 * notifier chain is used by balloon drivers to return the
5622	 * number of pages in a range that are held by the balloon
5623	 * driver to shrink memory. If all the pages are accounted for
5624	 * by balloons, are free, or on the LRU, isolation can continue.
5625	 * Later, for example, when memory hotplug notifier runs, these
5626	 * pages reported as "can be isolated" should be isolated(freed)
5627	 * by the balloon driver through the memory notifier chain.
5628	 */
5629	notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
5630	notifier_ret = notifier_to_errno(notifier_ret);
5631	if (notifier_ret)
5632		goto out;
5633	/*
5634	 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5635	 * We just check MOVABLE pages.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5636	 */
5637	if (__count_immobile_pages(zone, page, arg.pages_found))
5638		ret = 0;
 
 
 
 
 
 
 
 
5639
5640	/*
5641	 * immobile means "not-on-lru" paes. If immobile is larger than
5642	 * removable-by-driver pages reported by notifier, we'll fail.
 
 
 
 
 
 
 
 
 
 
 
 
5643	 */
5644
5645out:
5646	if (!ret) {
5647		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
5648		move_freepages_block(zone, page, MIGRATE_ISOLATE);
 
 
 
 
 
 
 
5649	}
5650
5651	spin_unlock_irqrestore(&zone->lock, flags);
5652	if (!ret)
5653		drain_all_pages();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5654	return ret;
5655}
5656
5657void unset_migratetype_isolate(struct page *page)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5658{
5659	struct zone *zone;
5660	unsigned long flags;
5661	zone = page_zone(page);
5662	spin_lock_irqsave(&zone->lock, flags);
5663	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
5664		goto out;
5665	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5666	move_freepages_block(zone, page, MIGRATE_MOVABLE);
5667out:
5668	spin_unlock_irqrestore(&zone->lock, flags);
 
 
 
 
 
 
5669}
5670
5671#ifdef CONFIG_MEMORY_HOTREMOVE
5672/*
5673 * All pages in the range must be isolated before calling this.
5674 */
5675void
5676__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
5677{
5678	struct page *page;
5679	struct zone *zone;
5680	int order, i;
5681	unsigned long pfn;
5682	unsigned long flags;
5683	/* find the first valid pfn */
5684	for (pfn = start_pfn; pfn < end_pfn; pfn++)
5685		if (pfn_valid(pfn))
5686			break;
5687	if (pfn == end_pfn)
5688		return;
5689	zone = page_zone(pfn_to_page(pfn));
5690	spin_lock_irqsave(&zone->lock, flags);
5691	pfn = start_pfn;
5692	while (pfn < end_pfn) {
5693		if (!pfn_valid(pfn)) {
5694			pfn++;
5695			continue;
5696		}
5697		page = pfn_to_page(pfn);
 
 
 
 
 
 
 
 
 
 
5698		BUG_ON(page_count(page));
5699		BUG_ON(!PageBuddy(page));
5700		order = page_order(page);
5701#ifdef CONFIG_DEBUG_VM
5702		printk(KERN_INFO "remove from free list %lx %d %lx\n",
5703		       pfn, 1 << order, end_pfn);
5704#endif
5705		list_del(&page->lru);
5706		rmv_page_order(page);
5707		zone->free_area[order].nr_free--;
5708		__mod_zone_page_state(zone, NR_FREE_PAGES,
5709				      - (1UL << order));
5710		for (i = 0; i < (1 << order); i++)
5711			SetPageReserved((page+i));
5712		pfn += (1 << order);
5713	}
5714	spin_unlock_irqrestore(&zone->lock, flags);
5715}
5716#endif
5717
5718#ifdef CONFIG_MEMORY_FAILURE
5719bool is_free_buddy_page(struct page *page)
5720{
5721	struct zone *zone = page_zone(page);
5722	unsigned long pfn = page_to_pfn(page);
5723	unsigned long flags;
5724	int order;
5725
5726	spin_lock_irqsave(&zone->lock, flags);
5727	for (order = 0; order < MAX_ORDER; order++) {
5728		struct page *page_head = page - (pfn & ((1 << order) - 1));
5729
5730		if (PageBuddy(page_head) && page_order(page_head) >= order)
5731			break;
5732	}
5733	spin_unlock_irqrestore(&zone->lock, flags);
5734
5735	return order < MAX_ORDER;
5736}
5737#endif
5738
5739static struct trace_print_flags pageflag_names[] = {
5740	{1UL << PG_locked,		"locked"	},
5741	{1UL << PG_error,		"error"		},
5742	{1UL << PG_referenced,		"referenced"	},
5743	{1UL << PG_uptodate,		"uptodate"	},
5744	{1UL << PG_dirty,		"dirty"		},
5745	{1UL << PG_lru,			"lru"		},
5746	{1UL << PG_active,		"active"	},
5747	{1UL << PG_slab,		"slab"		},
5748	{1UL << PG_owner_priv_1,	"owner_priv_1"	},
5749	{1UL << PG_arch_1,		"arch_1"	},
5750	{1UL << PG_reserved,		"reserved"	},
5751	{1UL << PG_private,		"private"	},
5752	{1UL << PG_private_2,		"private_2"	},
5753	{1UL << PG_writeback,		"writeback"	},
5754#ifdef CONFIG_PAGEFLAGS_EXTENDED
5755	{1UL << PG_head,		"head"		},
5756	{1UL << PG_tail,		"tail"		},
5757#else
5758	{1UL << PG_compound,		"compound"	},
5759#endif
5760	{1UL << PG_swapcache,		"swapcache"	},
5761	{1UL << PG_mappedtodisk,	"mappedtodisk"	},
5762	{1UL << PG_reclaim,		"reclaim"	},
5763	{1UL << PG_swapbacked,		"swapbacked"	},
5764	{1UL << PG_unevictable,		"unevictable"	},
5765#ifdef CONFIG_MMU
5766	{1UL << PG_mlocked,		"mlocked"	},
5767#endif
5768#ifdef CONFIG_ARCH_USES_PG_UNCACHED
5769	{1UL << PG_uncached,		"uncached"	},
5770#endif
5771#ifdef CONFIG_MEMORY_FAILURE
5772	{1UL << PG_hwpoison,		"hwpoison"	},
5773#endif
5774	{-1UL,				NULL		},
 
 
5775};
5776
5777static void dump_page_flags(unsigned long flags)
5778{
5779	const char *delim = "";
5780	unsigned long mask;
5781	int i;
5782
 
 
5783	printk(KERN_ALERT "page flags: %#lx(", flags);
5784
5785	/* remove zone id */
5786	flags &= (1UL << NR_PAGEFLAGS) - 1;
5787
5788	for (i = 0; pageflag_names[i].name && flags; i++) {
5789
5790		mask = pageflag_names[i].mask;
5791		if ((flags & mask) != mask)
5792			continue;
5793
5794		flags &= ~mask;
5795		printk("%s%s", delim, pageflag_names[i].name);
5796		delim = "|";
5797	}
5798
5799	/* check for left over flags */
5800	if (flags)
5801		printk("%s%#lx", delim, flags);
5802
5803	printk(")\n");
5804}
5805
5806void dump_page(struct page *page)
 
5807{
5808	printk(KERN_ALERT
5809	       "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5810		page, atomic_read(&page->_count), page_mapcount(page),
5811		page->mapping, page->index);
5812	dump_page_flags(page->flags);
 
 
 
 
 
 
5813	mem_cgroup_print_bad_page(page);
5814}