2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
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)
17 #include <linux/stddef.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/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/memremap.h>
47 #include <linux/stop_machine.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page_ext.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
67 #include <asm/sections.h>
68 #include <asm/tlbflush.h>
69 #include <asm/div64.h>
72 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
73 static DEFINE_MUTEX(pcp_batch_high_lock);
74 #define MIN_PERCPU_PAGELIST_FRACTION (8)
76 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
77 DEFINE_PER_CPU(int, numa_node);
78 EXPORT_PER_CPU_SYMBOL(numa_node);
81 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
83 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
84 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
85 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
86 * defined in <linux/topology.h>.
88 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
89 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
90 int _node_numa_mem_[MAX_NUMNODES];
94 * Array of node states.
96 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
97 [N_POSSIBLE] = NODE_MASK_ALL,
98 [N_ONLINE] = { { [0] = 1UL } },
100 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
101 #ifdef CONFIG_HIGHMEM
102 [N_HIGH_MEMORY] = { { [0] = 1UL } },
104 #ifdef CONFIG_MOVABLE_NODE
105 [N_MEMORY] = { { [0] = 1UL } },
107 [N_CPU] = { { [0] = 1UL } },
110 EXPORT_SYMBOL(node_states);
112 /* Protect totalram_pages and zone->managed_pages */
113 static DEFINE_SPINLOCK(managed_page_count_lock);
115 unsigned long totalram_pages __read_mostly;
116 unsigned long totalreserve_pages __read_mostly;
117 unsigned long totalcma_pages __read_mostly;
119 int percpu_pagelist_fraction;
120 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
123 * A cached value of the page's pageblock's migratetype, used when the page is
124 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
125 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
126 * Also the migratetype set in the page does not necessarily match the pcplist
127 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
128 * other index - this ensures that it will be put on the correct CMA freelist.
130 static inline int get_pcppage_migratetype(struct page *page)
135 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
137 page->index = migratetype;
140 #ifdef CONFIG_PM_SLEEP
142 * The following functions are used by the suspend/hibernate code to temporarily
143 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
144 * while devices are suspended. To avoid races with the suspend/hibernate code,
145 * they should always be called with pm_mutex held (gfp_allowed_mask also should
146 * only be modified with pm_mutex held, unless the suspend/hibernate code is
147 * guaranteed not to run in parallel with that modification).
150 static gfp_t saved_gfp_mask;
152 void pm_restore_gfp_mask(void)
154 WARN_ON(!mutex_is_locked(&pm_mutex));
155 if (saved_gfp_mask) {
156 gfp_allowed_mask = saved_gfp_mask;
161 void pm_restrict_gfp_mask(void)
163 WARN_ON(!mutex_is_locked(&pm_mutex));
164 WARN_ON(saved_gfp_mask);
165 saved_gfp_mask = gfp_allowed_mask;
166 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
169 bool pm_suspended_storage(void)
171 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
175 #endif /* CONFIG_PM_SLEEP */
177 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
178 unsigned int pageblock_order __read_mostly;
181 static void __free_pages_ok(struct page *page, unsigned int order);
184 * results with 256, 32 in the lowmem_reserve sysctl:
185 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
186 * 1G machine -> (16M dma, 784M normal, 224M high)
187 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
188 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
189 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
191 * TBD: should special case ZONE_DMA32 machines here - in those we normally
192 * don't need any ZONE_NORMAL reservation
194 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
195 #ifdef CONFIG_ZONE_DMA
198 #ifdef CONFIG_ZONE_DMA32
201 #ifdef CONFIG_HIGHMEM
207 EXPORT_SYMBOL(totalram_pages);
209 static char * const zone_names[MAX_NR_ZONES] = {
210 #ifdef CONFIG_ZONE_DMA
213 #ifdef CONFIG_ZONE_DMA32
217 #ifdef CONFIG_HIGHMEM
221 #ifdef CONFIG_ZONE_DEVICE
226 char * const migratetype_names[MIGRATE_TYPES] = {
234 #ifdef CONFIG_MEMORY_ISOLATION
239 compound_page_dtor * const compound_page_dtors[] = {
242 #ifdef CONFIG_HUGETLB_PAGE
245 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
250 int min_free_kbytes = 1024;
251 int user_min_free_kbytes = -1;
252 int watermark_scale_factor = 10;
254 static unsigned long __meminitdata nr_kernel_pages;
255 static unsigned long __meminitdata nr_all_pages;
256 static unsigned long __meminitdata dma_reserve;
258 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
259 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
260 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
261 static unsigned long __initdata required_kernelcore;
262 static unsigned long __initdata required_movablecore;
263 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
264 static bool mirrored_kernelcore;
266 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
268 EXPORT_SYMBOL(movable_zone);
269 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
272 int nr_node_ids __read_mostly = MAX_NUMNODES;
273 int nr_online_nodes __read_mostly = 1;
274 EXPORT_SYMBOL(nr_node_ids);
275 EXPORT_SYMBOL(nr_online_nodes);
278 int page_group_by_mobility_disabled __read_mostly;
280 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
281 static inline void reset_deferred_meminit(pg_data_t *pgdat)
283 pgdat->first_deferred_pfn = ULONG_MAX;
286 /* Returns true if the struct page for the pfn is uninitialised */
287 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
289 if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn)
295 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
297 if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
304 * Returns false when the remaining initialisation should be deferred until
305 * later in the boot cycle when it can be parallelised.
307 static inline bool update_defer_init(pg_data_t *pgdat,
308 unsigned long pfn, unsigned long zone_end,
309 unsigned long *nr_initialised)
311 unsigned long max_initialise;
313 /* Always populate low zones for address-contrained allocations */
314 if (zone_end < pgdat_end_pfn(pgdat))
317 * Initialise at least 2G of a node but also take into account that
318 * two large system hashes that can take up 1GB for 0.25TB/node.
320 max_initialise = max(2UL << (30 - PAGE_SHIFT),
321 (pgdat->node_spanned_pages >> 8));
324 if ((*nr_initialised > max_initialise) &&
325 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
326 pgdat->first_deferred_pfn = pfn;
333 static inline void reset_deferred_meminit(pg_data_t *pgdat)
337 static inline bool early_page_uninitialised(unsigned long pfn)
342 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
347 static inline bool update_defer_init(pg_data_t *pgdat,
348 unsigned long pfn, unsigned long zone_end,
349 unsigned long *nr_initialised)
355 /* Return a pointer to the bitmap storing bits affecting a block of pages */
356 static inline unsigned long *get_pageblock_bitmap(struct page *page,
359 #ifdef CONFIG_SPARSEMEM
360 return __pfn_to_section(pfn)->pageblock_flags;
362 return page_zone(page)->pageblock_flags;
363 #endif /* CONFIG_SPARSEMEM */
366 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
368 #ifdef CONFIG_SPARSEMEM
369 pfn &= (PAGES_PER_SECTION-1);
370 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
372 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
373 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
374 #endif /* CONFIG_SPARSEMEM */
378 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
379 * @page: The page within the block of interest
380 * @pfn: The target page frame number
381 * @end_bitidx: The last bit of interest to retrieve
382 * @mask: mask of bits that the caller is interested in
384 * Return: pageblock_bits flags
386 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
388 unsigned long end_bitidx,
391 unsigned long *bitmap;
392 unsigned long bitidx, word_bitidx;
395 bitmap = get_pageblock_bitmap(page, pfn);
396 bitidx = pfn_to_bitidx(page, pfn);
397 word_bitidx = bitidx / BITS_PER_LONG;
398 bitidx &= (BITS_PER_LONG-1);
400 word = bitmap[word_bitidx];
401 bitidx += end_bitidx;
402 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
405 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
406 unsigned long end_bitidx,
409 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
412 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
414 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
418 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
419 * @page: The page within the block of interest
420 * @flags: The flags to set
421 * @pfn: The target page frame number
422 * @end_bitidx: The last bit of interest
423 * @mask: mask of bits that the caller is interested in
425 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
427 unsigned long end_bitidx,
430 unsigned long *bitmap;
431 unsigned long bitidx, word_bitidx;
432 unsigned long old_word, word;
434 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
436 bitmap = get_pageblock_bitmap(page, pfn);
437 bitidx = pfn_to_bitidx(page, pfn);
438 word_bitidx = bitidx / BITS_PER_LONG;
439 bitidx &= (BITS_PER_LONG-1);
441 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
443 bitidx += end_bitidx;
444 mask <<= (BITS_PER_LONG - bitidx - 1);
445 flags <<= (BITS_PER_LONG - bitidx - 1);
447 word = READ_ONCE(bitmap[word_bitidx]);
449 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
450 if (word == old_word)
456 void set_pageblock_migratetype(struct page *page, int migratetype)
458 if (unlikely(page_group_by_mobility_disabled &&
459 migratetype < MIGRATE_PCPTYPES))
460 migratetype = MIGRATE_UNMOVABLE;
462 set_pageblock_flags_group(page, (unsigned long)migratetype,
463 PB_migrate, PB_migrate_end);
466 #ifdef CONFIG_DEBUG_VM
467 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
471 unsigned long pfn = page_to_pfn(page);
472 unsigned long sp, start_pfn;
475 seq = zone_span_seqbegin(zone);
476 start_pfn = zone->zone_start_pfn;
477 sp = zone->spanned_pages;
478 if (!zone_spans_pfn(zone, pfn))
480 } while (zone_span_seqretry(zone, seq));
483 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
484 pfn, zone_to_nid(zone), zone->name,
485 start_pfn, start_pfn + sp);
490 static int page_is_consistent(struct zone *zone, struct page *page)
492 if (!pfn_valid_within(page_to_pfn(page)))
494 if (zone != page_zone(page))
500 * Temporary debugging check for pages not lying within a given zone.
502 static int bad_range(struct zone *zone, struct page *page)
504 if (page_outside_zone_boundaries(zone, page))
506 if (!page_is_consistent(zone, page))
512 static inline int bad_range(struct zone *zone, struct page *page)
518 static void bad_page(struct page *page, const char *reason,
519 unsigned long bad_flags)
521 static unsigned long resume;
522 static unsigned long nr_shown;
523 static unsigned long nr_unshown;
525 /* Don't complain about poisoned pages */
526 if (PageHWPoison(page)) {
527 page_mapcount_reset(page); /* remove PageBuddy */
532 * Allow a burst of 60 reports, then keep quiet for that minute;
533 * or allow a steady drip of one report per second.
535 if (nr_shown == 60) {
536 if (time_before(jiffies, resume)) {
542 "BUG: Bad page state: %lu messages suppressed\n",
549 resume = jiffies + 60 * HZ;
551 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
552 current->comm, page_to_pfn(page));
553 __dump_page(page, reason);
554 bad_flags &= page->flags;
556 pr_alert("bad because of flags: %#lx(%pGp)\n",
557 bad_flags, &bad_flags);
558 dump_page_owner(page);
563 /* Leave bad fields for debug, except PageBuddy could make trouble */
564 page_mapcount_reset(page); /* remove PageBuddy */
565 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
569 * Higher-order pages are called "compound pages". They are structured thusly:
571 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
573 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
574 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
576 * The first tail page's ->compound_dtor holds the offset in array of compound
577 * page destructors. See compound_page_dtors.
579 * The first tail page's ->compound_order holds the order of allocation.
580 * This usage means that zero-order pages may not be compound.
583 void free_compound_page(struct page *page)
585 __free_pages_ok(page, compound_order(page));
588 void prep_compound_page(struct page *page, unsigned int order)
591 int nr_pages = 1 << order;
593 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
594 set_compound_order(page, order);
596 for (i = 1; i < nr_pages; i++) {
597 struct page *p = page + i;
598 set_page_count(p, 0);
599 p->mapping = TAIL_MAPPING;
600 set_compound_head(p, page);
602 atomic_set(compound_mapcount_ptr(page), -1);
605 #ifdef CONFIG_DEBUG_PAGEALLOC
606 unsigned int _debug_guardpage_minorder;
607 bool _debug_pagealloc_enabled __read_mostly
608 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
609 EXPORT_SYMBOL(_debug_pagealloc_enabled);
610 bool _debug_guardpage_enabled __read_mostly;
612 static int __init early_debug_pagealloc(char *buf)
617 if (strcmp(buf, "on") == 0)
618 _debug_pagealloc_enabled = true;
620 if (strcmp(buf, "off") == 0)
621 _debug_pagealloc_enabled = false;
625 early_param("debug_pagealloc", early_debug_pagealloc);
627 static bool need_debug_guardpage(void)
629 /* If we don't use debug_pagealloc, we don't need guard page */
630 if (!debug_pagealloc_enabled())
636 static void init_debug_guardpage(void)
638 if (!debug_pagealloc_enabled())
641 _debug_guardpage_enabled = true;
644 struct page_ext_operations debug_guardpage_ops = {
645 .need = need_debug_guardpage,
646 .init = init_debug_guardpage,
649 static int __init debug_guardpage_minorder_setup(char *buf)
653 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
654 pr_err("Bad debug_guardpage_minorder value\n");
657 _debug_guardpage_minorder = res;
658 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
661 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
663 static inline void set_page_guard(struct zone *zone, struct page *page,
664 unsigned int order, int migratetype)
666 struct page_ext *page_ext;
668 if (!debug_guardpage_enabled())
671 page_ext = lookup_page_ext(page);
672 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
674 INIT_LIST_HEAD(&page->lru);
675 set_page_private(page, order);
676 /* Guard pages are not available for any usage */
677 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
680 static inline void clear_page_guard(struct zone *zone, struct page *page,
681 unsigned int order, int migratetype)
683 struct page_ext *page_ext;
685 if (!debug_guardpage_enabled())
688 page_ext = lookup_page_ext(page);
689 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
691 set_page_private(page, 0);
692 if (!is_migrate_isolate(migratetype))
693 __mod_zone_freepage_state(zone, (1 << order), migratetype);
696 struct page_ext_operations debug_guardpage_ops = { NULL, };
697 static inline void set_page_guard(struct zone *zone, struct page *page,
698 unsigned int order, int migratetype) {}
699 static inline void clear_page_guard(struct zone *zone, struct page *page,
700 unsigned int order, int migratetype) {}
703 static inline void set_page_order(struct page *page, unsigned int order)
705 set_page_private(page, order);
706 __SetPageBuddy(page);
709 static inline void rmv_page_order(struct page *page)
711 __ClearPageBuddy(page);
712 set_page_private(page, 0);
716 * This function checks whether a page is free && is the buddy
717 * we can do coalesce a page and its buddy if
718 * (a) the buddy is not in a hole &&
719 * (b) the buddy is in the buddy system &&
720 * (c) a page and its buddy have the same order &&
721 * (d) a page and its buddy are in the same zone.
723 * For recording whether a page is in the buddy system, we set ->_mapcount
724 * PAGE_BUDDY_MAPCOUNT_VALUE.
725 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
726 * serialized by zone->lock.
728 * For recording page's order, we use page_private(page).
730 static inline int page_is_buddy(struct page *page, struct page *buddy,
733 if (!pfn_valid_within(page_to_pfn(buddy)))
736 if (page_is_guard(buddy) && page_order(buddy) == order) {
737 if (page_zone_id(page) != page_zone_id(buddy))
740 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
745 if (PageBuddy(buddy) && page_order(buddy) == order) {
747 * zone check is done late to avoid uselessly
748 * calculating zone/node ids for pages that could
751 if (page_zone_id(page) != page_zone_id(buddy))
754 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
762 * Freeing function for a buddy system allocator.
764 * The concept of a buddy system is to maintain direct-mapped table
765 * (containing bit values) for memory blocks of various "orders".
766 * The bottom level table contains the map for the smallest allocatable
767 * units of memory (here, pages), and each level above it describes
768 * pairs of units from the levels below, hence, "buddies".
769 * At a high level, all that happens here is marking the table entry
770 * at the bottom level available, and propagating the changes upward
771 * as necessary, plus some accounting needed to play nicely with other
772 * parts of the VM system.
773 * At each level, we keep a list of pages, which are heads of continuous
774 * free pages of length of (1 << order) and marked with _mapcount
775 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
777 * So when we are allocating or freeing one, we can derive the state of the
778 * other. That is, if we allocate a small block, and both were
779 * free, the remainder of the region must be split into blocks.
780 * If a block is freed, and its buddy is also free, then this
781 * triggers coalescing into a block of larger size.
786 static inline void __free_one_page(struct page *page,
788 struct zone *zone, unsigned int order,
791 unsigned long page_idx;
792 unsigned long combined_idx;
793 unsigned long uninitialized_var(buddy_idx);
795 unsigned int max_order;
797 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
799 VM_BUG_ON(!zone_is_initialized(zone));
800 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
802 VM_BUG_ON(migratetype == -1);
803 if (likely(!is_migrate_isolate(migratetype)))
804 __mod_zone_freepage_state(zone, 1 << order, migratetype);
806 page_idx = pfn & ((1 << MAX_ORDER) - 1);
808 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
809 VM_BUG_ON_PAGE(bad_range(zone, page), page);
812 while (order < max_order - 1) {
813 buddy_idx = __find_buddy_index(page_idx, order);
814 buddy = page + (buddy_idx - page_idx);
815 if (!page_is_buddy(page, buddy, order))
818 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
819 * merge with it and move up one order.
821 if (page_is_guard(buddy)) {
822 clear_page_guard(zone, buddy, order, migratetype);
824 list_del(&buddy->lru);
825 zone->free_area[order].nr_free--;
826 rmv_page_order(buddy);
828 combined_idx = buddy_idx & page_idx;
829 page = page + (combined_idx - page_idx);
830 page_idx = combined_idx;
833 if (max_order < MAX_ORDER) {
834 /* If we are here, it means order is >= pageblock_order.
835 * We want to prevent merge between freepages on isolate
836 * pageblock and normal pageblock. Without this, pageblock
837 * isolation could cause incorrect freepage or CMA accounting.
839 * We don't want to hit this code for the more frequent
842 if (unlikely(has_isolate_pageblock(zone))) {
845 buddy_idx = __find_buddy_index(page_idx, order);
846 buddy = page + (buddy_idx - page_idx);
847 buddy_mt = get_pageblock_migratetype(buddy);
849 if (migratetype != buddy_mt
850 && (is_migrate_isolate(migratetype) ||
851 is_migrate_isolate(buddy_mt)))
855 goto continue_merging;
859 set_page_order(page, order);
862 * If this is not the largest possible page, check if the buddy
863 * of the next-highest order is free. If it is, it's possible
864 * that pages are being freed that will coalesce soon. In case,
865 * that is happening, add the free page to the tail of the list
866 * so it's less likely to be used soon and more likely to be merged
867 * as a higher order page
869 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
870 struct page *higher_page, *higher_buddy;
871 combined_idx = buddy_idx & page_idx;
872 higher_page = page + (combined_idx - page_idx);
873 buddy_idx = __find_buddy_index(combined_idx, order + 1);
874 higher_buddy = higher_page + (buddy_idx - combined_idx);
875 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
876 list_add_tail(&page->lru,
877 &zone->free_area[order].free_list[migratetype]);
882 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
884 zone->free_area[order].nr_free++;
888 * A bad page could be due to a number of fields. Instead of multiple branches,
889 * try and check multiple fields with one check. The caller must do a detailed
890 * check if necessary.
892 static inline bool page_expected_state(struct page *page,
893 unsigned long check_flags)
895 if (unlikely(atomic_read(&page->_mapcount) != -1))
898 if (unlikely((unsigned long)page->mapping |
899 page_ref_count(page) |
901 (unsigned long)page->mem_cgroup |
903 (page->flags & check_flags)))
909 static void free_pages_check_bad(struct page *page)
911 const char *bad_reason;
912 unsigned long bad_flags;
917 if (unlikely(atomic_read(&page->_mapcount) != -1))
918 bad_reason = "nonzero mapcount";
919 if (unlikely(page->mapping != NULL))
920 bad_reason = "non-NULL mapping";
921 if (unlikely(page_ref_count(page) != 0))
922 bad_reason = "nonzero _refcount";
923 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
924 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
925 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
928 if (unlikely(page->mem_cgroup))
929 bad_reason = "page still charged to cgroup";
931 bad_page(page, bad_reason, bad_flags);
934 static inline int free_pages_check(struct page *page)
936 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
939 /* Something has gone sideways, find it */
940 free_pages_check_bad(page);
945 * Frees a number of pages from the PCP lists
946 * Assumes all pages on list are in same zone, and of same order.
947 * count is the number of pages to free.
949 * If the zone was previously in an "all pages pinned" state then look to
950 * see if this freeing clears that state.
952 * And clear the zone's pages_scanned counter, to hold off the "all pages are
953 * pinned" detection logic.
955 static void free_pcppages_bulk(struct zone *zone, int count,
956 struct per_cpu_pages *pcp)
960 unsigned long nr_scanned;
961 bool isolated_pageblocks;
963 spin_lock(&zone->lock);
964 isolated_pageblocks = has_isolate_pageblock(zone);
965 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
967 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
971 struct list_head *list;
974 * Remove pages from lists in a round-robin fashion. A
975 * batch_free count is maintained that is incremented when an
976 * empty list is encountered. This is so more pages are freed
977 * off fuller lists instead of spinning excessively around empty
982 if (++migratetype == MIGRATE_PCPTYPES)
984 list = &pcp->lists[migratetype];
985 } while (list_empty(list));
987 /* This is the only non-empty list. Free them all. */
988 if (batch_free == MIGRATE_PCPTYPES)
992 int mt; /* migratetype of the to-be-freed page */
994 page = list_last_entry(list, struct page, lru);
995 /* must delete as __free_one_page list manipulates */
996 list_del(&page->lru);
998 mt = get_pcppage_migratetype(page);
999 /* MIGRATE_ISOLATE page should not go to pcplists */
1000 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1001 /* Pageblock could have been isolated meanwhile */
1002 if (unlikely(isolated_pageblocks))
1003 mt = get_pageblock_migratetype(page);
1005 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1006 trace_mm_page_pcpu_drain(page, 0, mt);
1007 } while (--count && --batch_free && !list_empty(list));
1009 spin_unlock(&zone->lock);
1012 static void free_one_page(struct zone *zone,
1013 struct page *page, unsigned long pfn,
1017 unsigned long nr_scanned;
1018 spin_lock(&zone->lock);
1019 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1021 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1023 if (unlikely(has_isolate_pageblock(zone) ||
1024 is_migrate_isolate(migratetype))) {
1025 migratetype = get_pfnblock_migratetype(page, pfn);
1027 __free_one_page(page, pfn, zone, order, migratetype);
1028 spin_unlock(&zone->lock);
1031 static int free_tail_pages_check(struct page *head_page, struct page *page)
1036 * We rely page->lru.next never has bit 0 set, unless the page
1037 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1039 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
1041 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
1045 switch (page - head_page) {
1047 /* the first tail page: ->mapping is compound_mapcount() */
1048 if (unlikely(compound_mapcount(page))) {
1049 bad_page(page, "nonzero compound_mapcount", 0);
1055 * the second tail page: ->mapping is
1056 * page_deferred_list().next -- ignore value.
1060 if (page->mapping != TAIL_MAPPING) {
1061 bad_page(page, "corrupted mapping in tail page", 0);
1066 if (unlikely(!PageTail(page))) {
1067 bad_page(page, "PageTail not set", 0);
1070 if (unlikely(compound_head(page) != head_page)) {
1071 bad_page(page, "compound_head not consistent", 0);
1076 page->mapping = NULL;
1077 clear_compound_head(page);
1081 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1082 unsigned long zone, int nid)
1084 set_page_links(page, zone, nid, pfn);
1085 init_page_count(page);
1086 page_mapcount_reset(page);
1087 page_cpupid_reset_last(page);
1089 INIT_LIST_HEAD(&page->lru);
1090 #ifdef WANT_PAGE_VIRTUAL
1091 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1092 if (!is_highmem_idx(zone))
1093 set_page_address(page, __va(pfn << PAGE_SHIFT));
1097 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
1100 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
1103 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1104 static void init_reserved_page(unsigned long pfn)
1109 if (!early_page_uninitialised(pfn))
1112 nid = early_pfn_to_nid(pfn);
1113 pgdat = NODE_DATA(nid);
1115 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1116 struct zone *zone = &pgdat->node_zones[zid];
1118 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1121 __init_single_pfn(pfn, zid, nid);
1124 static inline void init_reserved_page(unsigned long pfn)
1127 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1130 * Initialised pages do not have PageReserved set. This function is
1131 * called for each range allocated by the bootmem allocator and
1132 * marks the pages PageReserved. The remaining valid pages are later
1133 * sent to the buddy page allocator.
1135 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
1137 unsigned long start_pfn = PFN_DOWN(start);
1138 unsigned long end_pfn = PFN_UP(end);
1140 for (; start_pfn < end_pfn; start_pfn++) {
1141 if (pfn_valid(start_pfn)) {
1142 struct page *page = pfn_to_page(start_pfn);
1144 init_reserved_page(start_pfn);
1146 /* Avoid false-positive PageTail() */
1147 INIT_LIST_HEAD(&page->lru);
1149 SetPageReserved(page);
1154 static bool free_pages_prepare(struct page *page, unsigned int order)
1158 VM_BUG_ON_PAGE(PageTail(page), page);
1160 trace_mm_page_free(page, order);
1161 kmemcheck_free_shadow(page, order);
1162 kasan_free_pages(page, order);
1165 * Check tail pages before head page information is cleared to
1166 * avoid checking PageCompound for order-0 pages.
1168 if (unlikely(order)) {
1169 bool compound = PageCompound(page);
1172 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1174 for (i = 1; i < (1 << order); i++) {
1176 bad += free_tail_pages_check(page, page + i);
1177 if (unlikely(free_pages_check(page + i))) {
1181 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1184 if (PageAnonHead(page))
1185 page->mapping = NULL;
1186 bad += free_pages_check(page);
1190 page_cpupid_reset_last(page);
1191 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1192 reset_page_owner(page, order);
1194 if (!PageHighMem(page)) {
1195 debug_check_no_locks_freed(page_address(page),
1196 PAGE_SIZE << order);
1197 debug_check_no_obj_freed(page_address(page),
1198 PAGE_SIZE << order);
1200 arch_free_page(page, order);
1201 kernel_poison_pages(page, 1 << order, 0);
1202 kernel_map_pages(page, 1 << order, 0);
1207 static void __free_pages_ok(struct page *page, unsigned int order)
1209 unsigned long flags;
1211 unsigned long pfn = page_to_pfn(page);
1213 if (!free_pages_prepare(page, order))
1216 migratetype = get_pfnblock_migratetype(page, pfn);
1217 local_irq_save(flags);
1218 __count_vm_events(PGFREE, 1 << order);
1219 free_one_page(page_zone(page), page, pfn, order, migratetype);
1220 local_irq_restore(flags);
1223 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1225 unsigned int nr_pages = 1 << order;
1226 struct page *p = page;
1230 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1232 __ClearPageReserved(p);
1233 set_page_count(p, 0);
1235 __ClearPageReserved(p);
1236 set_page_count(p, 0);
1238 page_zone(page)->managed_pages += nr_pages;
1239 set_page_refcounted(page);
1240 __free_pages(page, order);
1243 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1244 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1246 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1248 int __meminit early_pfn_to_nid(unsigned long pfn)
1250 static DEFINE_SPINLOCK(early_pfn_lock);
1253 spin_lock(&early_pfn_lock);
1254 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1257 spin_unlock(&early_pfn_lock);
1263 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1264 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1265 struct mminit_pfnnid_cache *state)
1269 nid = __early_pfn_to_nid(pfn, state);
1270 if (nid >= 0 && nid != node)
1275 /* Only safe to use early in boot when initialisation is single-threaded */
1276 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1278 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1283 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1287 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1288 struct mminit_pfnnid_cache *state)
1295 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1298 if (early_page_uninitialised(pfn))
1300 return __free_pages_boot_core(page, order);
1304 * Check that the whole (or subset of) a pageblock given by the interval of
1305 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1306 * with the migration of free compaction scanner. The scanners then need to
1307 * use only pfn_valid_within() check for arches that allow holes within
1310 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1312 * It's possible on some configurations to have a setup like node0 node1 node0
1313 * i.e. it's possible that all pages within a zones range of pages do not
1314 * belong to a single zone. We assume that a border between node0 and node1
1315 * can occur within a single pageblock, but not a node0 node1 node0
1316 * interleaving within a single pageblock. It is therefore sufficient to check
1317 * the first and last page of a pageblock and avoid checking each individual
1318 * page in a pageblock.
1320 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1321 unsigned long end_pfn, struct zone *zone)
1323 struct page *start_page;
1324 struct page *end_page;
1326 /* end_pfn is one past the range we are checking */
1329 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1332 start_page = pfn_to_page(start_pfn);
1334 if (page_zone(start_page) != zone)
1337 end_page = pfn_to_page(end_pfn);
1339 /* This gives a shorter code than deriving page_zone(end_page) */
1340 if (page_zone_id(start_page) != page_zone_id(end_page))
1346 void set_zone_contiguous(struct zone *zone)
1348 unsigned long block_start_pfn = zone->zone_start_pfn;
1349 unsigned long block_end_pfn;
1351 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1352 for (; block_start_pfn < zone_end_pfn(zone);
1353 block_start_pfn = block_end_pfn,
1354 block_end_pfn += pageblock_nr_pages) {
1356 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1358 if (!__pageblock_pfn_to_page(block_start_pfn,
1359 block_end_pfn, zone))
1363 /* We confirm that there is no hole */
1364 zone->contiguous = true;
1367 void clear_zone_contiguous(struct zone *zone)
1369 zone->contiguous = false;
1372 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1373 static void __init deferred_free_range(struct page *page,
1374 unsigned long pfn, int nr_pages)
1381 /* Free a large naturally-aligned chunk if possible */
1382 if (nr_pages == MAX_ORDER_NR_PAGES &&
1383 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1384 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1385 __free_pages_boot_core(page, MAX_ORDER-1);
1389 for (i = 0; i < nr_pages; i++, page++)
1390 __free_pages_boot_core(page, 0);
1393 /* Completion tracking for deferred_init_memmap() threads */
1394 static atomic_t pgdat_init_n_undone __initdata;
1395 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1397 static inline void __init pgdat_init_report_one_done(void)
1399 if (atomic_dec_and_test(&pgdat_init_n_undone))
1400 complete(&pgdat_init_all_done_comp);
1403 /* Initialise remaining memory on a node */
1404 static int __init deferred_init_memmap(void *data)
1406 pg_data_t *pgdat = data;
1407 int nid = pgdat->node_id;
1408 struct mminit_pfnnid_cache nid_init_state = { };
1409 unsigned long start = jiffies;
1410 unsigned long nr_pages = 0;
1411 unsigned long walk_start, walk_end;
1414 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1415 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1417 if (first_init_pfn == ULONG_MAX) {
1418 pgdat_init_report_one_done();
1422 /* Bind memory initialisation thread to a local node if possible */
1423 if (!cpumask_empty(cpumask))
1424 set_cpus_allowed_ptr(current, cpumask);
1426 /* Sanity check boundaries */
1427 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1428 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1429 pgdat->first_deferred_pfn = ULONG_MAX;
1431 /* Only the highest zone is deferred so find it */
1432 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1433 zone = pgdat->node_zones + zid;
1434 if (first_init_pfn < zone_end_pfn(zone))
1438 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1439 unsigned long pfn, end_pfn;
1440 struct page *page = NULL;
1441 struct page *free_base_page = NULL;
1442 unsigned long free_base_pfn = 0;
1445 end_pfn = min(walk_end, zone_end_pfn(zone));
1446 pfn = first_init_pfn;
1447 if (pfn < walk_start)
1449 if (pfn < zone->zone_start_pfn)
1450 pfn = zone->zone_start_pfn;
1452 for (; pfn < end_pfn; pfn++) {
1453 if (!pfn_valid_within(pfn))
1457 * Ensure pfn_valid is checked every
1458 * MAX_ORDER_NR_PAGES for memory holes
1460 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1461 if (!pfn_valid(pfn)) {
1467 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1472 /* Minimise pfn page lookups and scheduler checks */
1473 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1476 nr_pages += nr_to_free;
1477 deferred_free_range(free_base_page,
1478 free_base_pfn, nr_to_free);
1479 free_base_page = NULL;
1480 free_base_pfn = nr_to_free = 0;
1482 page = pfn_to_page(pfn);
1487 VM_BUG_ON(page_zone(page) != zone);
1491 __init_single_page(page, pfn, zid, nid);
1492 if (!free_base_page) {
1493 free_base_page = page;
1494 free_base_pfn = pfn;
1499 /* Where possible, batch up pages for a single free */
1502 /* Free the current block of pages to allocator */
1503 nr_pages += nr_to_free;
1504 deferred_free_range(free_base_page, free_base_pfn,
1506 free_base_page = NULL;
1507 free_base_pfn = nr_to_free = 0;
1510 first_init_pfn = max(end_pfn, first_init_pfn);
1513 /* Sanity check that the next zone really is unpopulated */
1514 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1516 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1517 jiffies_to_msecs(jiffies - start));
1519 pgdat_init_report_one_done();
1522 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1524 void __init page_alloc_init_late(void)
1528 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1531 /* There will be num_node_state(N_MEMORY) threads */
1532 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1533 for_each_node_state(nid, N_MEMORY) {
1534 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1537 /* Block until all are initialised */
1538 wait_for_completion(&pgdat_init_all_done_comp);
1540 /* Reinit limits that are based on free pages after the kernel is up */
1541 files_maxfiles_init();
1544 for_each_populated_zone(zone)
1545 set_zone_contiguous(zone);
1549 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1550 void __init init_cma_reserved_pageblock(struct page *page)
1552 unsigned i = pageblock_nr_pages;
1553 struct page *p = page;
1556 __ClearPageReserved(p);
1557 set_page_count(p, 0);
1560 set_pageblock_migratetype(page, MIGRATE_CMA);
1562 if (pageblock_order >= MAX_ORDER) {
1563 i = pageblock_nr_pages;
1566 set_page_refcounted(p);
1567 __free_pages(p, MAX_ORDER - 1);
1568 p += MAX_ORDER_NR_PAGES;
1569 } while (i -= MAX_ORDER_NR_PAGES);
1571 set_page_refcounted(page);
1572 __free_pages(page, pageblock_order);
1575 adjust_managed_page_count(page, pageblock_nr_pages);
1580 * The order of subdivision here is critical for the IO subsystem.
1581 * Please do not alter this order without good reasons and regression
1582 * testing. Specifically, as large blocks of memory are subdivided,
1583 * the order in which smaller blocks are delivered depends on the order
1584 * they're subdivided in this function. This is the primary factor
1585 * influencing the order in which pages are delivered to the IO
1586 * subsystem according to empirical testing, and this is also justified
1587 * by considering the behavior of a buddy system containing a single
1588 * large block of memory acted on by a series of small allocations.
1589 * This behavior is a critical factor in sglist merging's success.
1593 static inline void expand(struct zone *zone, struct page *page,
1594 int low, int high, struct free_area *area,
1597 unsigned long size = 1 << high;
1599 while (high > low) {
1603 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1605 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1606 debug_guardpage_enabled() &&
1607 high < debug_guardpage_minorder()) {
1609 * Mark as guard pages (or page), that will allow to
1610 * merge back to allocator when buddy will be freed.
1611 * Corresponding page table entries will not be touched,
1612 * pages will stay not present in virtual address space
1614 set_page_guard(zone, &page[size], high, migratetype);
1617 list_add(&page[size].lru, &area->free_list[migratetype]);
1619 set_page_order(&page[size], high);
1624 * This page is about to be returned from the page allocator
1626 static inline int check_new_page(struct page *page)
1628 const char *bad_reason;
1629 unsigned long bad_flags;
1631 if (page_expected_state(page, PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON))
1636 if (unlikely(atomic_read(&page->_mapcount) != -1))
1637 bad_reason = "nonzero mapcount";
1638 if (unlikely(page->mapping != NULL))
1639 bad_reason = "non-NULL mapping";
1640 if (unlikely(page_ref_count(page) != 0))
1641 bad_reason = "nonzero _count";
1642 if (unlikely(page->flags & __PG_HWPOISON)) {
1643 bad_reason = "HWPoisoned (hardware-corrupted)";
1644 bad_flags = __PG_HWPOISON;
1646 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1647 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1648 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1651 if (unlikely(page->mem_cgroup))
1652 bad_reason = "page still charged to cgroup";
1654 if (unlikely(bad_reason)) {
1655 bad_page(page, bad_reason, bad_flags);
1661 static inline bool free_pages_prezeroed(bool poisoned)
1663 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1664 page_poisoning_enabled() && poisoned;
1667 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1668 unsigned int alloc_flags)
1671 bool poisoned = true;
1673 for (i = 0; i < (1 << order); i++) {
1674 struct page *p = page + i;
1675 if (unlikely(check_new_page(p)))
1678 poisoned &= page_is_poisoned(p);
1681 set_page_private(page, 0);
1682 set_page_refcounted(page);
1684 arch_alloc_page(page, order);
1685 kernel_map_pages(page, 1 << order, 1);
1686 kernel_poison_pages(page, 1 << order, 1);
1687 kasan_alloc_pages(page, order);
1689 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1690 for (i = 0; i < (1 << order); i++)
1691 clear_highpage(page + i);
1693 if (order && (gfp_flags & __GFP_COMP))
1694 prep_compound_page(page, order);
1696 set_page_owner(page, order, gfp_flags);
1699 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1700 * allocate the page. The expectation is that the caller is taking
1701 * steps that will free more memory. The caller should avoid the page
1702 * being used for !PFMEMALLOC purposes.
1704 if (alloc_flags & ALLOC_NO_WATERMARKS)
1705 set_page_pfmemalloc(page);
1707 clear_page_pfmemalloc(page);
1713 * Go through the free lists for the given migratetype and remove
1714 * the smallest available page from the freelists
1717 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1720 unsigned int current_order;
1721 struct free_area *area;
1724 /* Find a page of the appropriate size in the preferred list */
1725 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1726 area = &(zone->free_area[current_order]);
1727 page = list_first_entry_or_null(&area->free_list[migratetype],
1731 list_del(&page->lru);
1732 rmv_page_order(page);
1734 expand(zone, page, order, current_order, area, migratetype);
1735 set_pcppage_migratetype(page, migratetype);
1744 * This array describes the order lists are fallen back to when
1745 * the free lists for the desirable migrate type are depleted
1747 static int fallbacks[MIGRATE_TYPES][4] = {
1748 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1749 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1750 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1752 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1754 #ifdef CONFIG_MEMORY_ISOLATION
1755 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1760 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1763 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1766 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1767 unsigned int order) { return NULL; }
1771 * Move the free pages in a range to the free lists of the requested type.
1772 * Note that start_page and end_pages are not aligned on a pageblock
1773 * boundary. If alignment is required, use move_freepages_block()
1775 int move_freepages(struct zone *zone,
1776 struct page *start_page, struct page *end_page,
1781 int pages_moved = 0;
1783 #ifndef CONFIG_HOLES_IN_ZONE
1785 * page_zone is not safe to call in this context when
1786 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1787 * anyway as we check zone boundaries in move_freepages_block().
1788 * Remove at a later date when no bug reports exist related to
1789 * grouping pages by mobility
1791 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1794 for (page = start_page; page <= end_page;) {
1795 /* Make sure we are not inadvertently changing nodes */
1796 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1798 if (!pfn_valid_within(page_to_pfn(page))) {
1803 if (!PageBuddy(page)) {
1808 order = page_order(page);
1809 list_move(&page->lru,
1810 &zone->free_area[order].free_list[migratetype]);
1812 pages_moved += 1 << order;
1818 int move_freepages_block(struct zone *zone, struct page *page,
1821 unsigned long start_pfn, end_pfn;
1822 struct page *start_page, *end_page;
1824 start_pfn = page_to_pfn(page);
1825 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1826 start_page = pfn_to_page(start_pfn);
1827 end_page = start_page + pageblock_nr_pages - 1;
1828 end_pfn = start_pfn + pageblock_nr_pages - 1;
1830 /* Do not cross zone boundaries */
1831 if (!zone_spans_pfn(zone, start_pfn))
1833 if (!zone_spans_pfn(zone, end_pfn))
1836 return move_freepages(zone, start_page, end_page, migratetype);
1839 static void change_pageblock_range(struct page *pageblock_page,
1840 int start_order, int migratetype)
1842 int nr_pageblocks = 1 << (start_order - pageblock_order);
1844 while (nr_pageblocks--) {
1845 set_pageblock_migratetype(pageblock_page, migratetype);
1846 pageblock_page += pageblock_nr_pages;
1851 * When we are falling back to another migratetype during allocation, try to
1852 * steal extra free pages from the same pageblocks to satisfy further
1853 * allocations, instead of polluting multiple pageblocks.
1855 * If we are stealing a relatively large buddy page, it is likely there will
1856 * be more free pages in the pageblock, so try to steal them all. For
1857 * reclaimable and unmovable allocations, we steal regardless of page size,
1858 * as fragmentation caused by those allocations polluting movable pageblocks
1859 * is worse than movable allocations stealing from unmovable and reclaimable
1862 static bool can_steal_fallback(unsigned int order, int start_mt)
1865 * Leaving this order check is intended, although there is
1866 * relaxed order check in next check. The reason is that
1867 * we can actually steal whole pageblock if this condition met,
1868 * but, below check doesn't guarantee it and that is just heuristic
1869 * so could be changed anytime.
1871 if (order >= pageblock_order)
1874 if (order >= pageblock_order / 2 ||
1875 start_mt == MIGRATE_RECLAIMABLE ||
1876 start_mt == MIGRATE_UNMOVABLE ||
1877 page_group_by_mobility_disabled)
1884 * This function implements actual steal behaviour. If order is large enough,
1885 * we can steal whole pageblock. If not, we first move freepages in this
1886 * pageblock and check whether half of pages are moved or not. If half of
1887 * pages are moved, we can change migratetype of pageblock and permanently
1888 * use it's pages as requested migratetype in the future.
1890 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1893 unsigned int current_order = page_order(page);
1896 /* Take ownership for orders >= pageblock_order */
1897 if (current_order >= pageblock_order) {
1898 change_pageblock_range(page, current_order, start_type);
1902 pages = move_freepages_block(zone, page, start_type);
1904 /* Claim the whole block if over half of it is free */
1905 if (pages >= (1 << (pageblock_order-1)) ||
1906 page_group_by_mobility_disabled)
1907 set_pageblock_migratetype(page, start_type);
1911 * Check whether there is a suitable fallback freepage with requested order.
1912 * If only_stealable is true, this function returns fallback_mt only if
1913 * we can steal other freepages all together. This would help to reduce
1914 * fragmentation due to mixed migratetype pages in one pageblock.
1916 int find_suitable_fallback(struct free_area *area, unsigned int order,
1917 int migratetype, bool only_stealable, bool *can_steal)
1922 if (area->nr_free == 0)
1927 fallback_mt = fallbacks[migratetype][i];
1928 if (fallback_mt == MIGRATE_TYPES)
1931 if (list_empty(&area->free_list[fallback_mt]))
1934 if (can_steal_fallback(order, migratetype))
1937 if (!only_stealable)
1948 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1949 * there are no empty page blocks that contain a page with a suitable order
1951 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
1952 unsigned int alloc_order)
1955 unsigned long max_managed, flags;
1958 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1959 * Check is race-prone but harmless.
1961 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
1962 if (zone->nr_reserved_highatomic >= max_managed)
1965 spin_lock_irqsave(&zone->lock, flags);
1967 /* Recheck the nr_reserved_highatomic limit under the lock */
1968 if (zone->nr_reserved_highatomic >= max_managed)
1972 mt = get_pageblock_migratetype(page);
1973 if (mt != MIGRATE_HIGHATOMIC &&
1974 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
1975 zone->nr_reserved_highatomic += pageblock_nr_pages;
1976 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
1977 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
1981 spin_unlock_irqrestore(&zone->lock, flags);
1985 * Used when an allocation is about to fail under memory pressure. This
1986 * potentially hurts the reliability of high-order allocations when under
1987 * intense memory pressure but failed atomic allocations should be easier
1988 * to recover from than an OOM.
1990 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
1992 struct zonelist *zonelist = ac->zonelist;
1993 unsigned long flags;
1999 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2001 /* Preserve at least one pageblock */
2002 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
2005 spin_lock_irqsave(&zone->lock, flags);
2006 for (order = 0; order < MAX_ORDER; order++) {
2007 struct free_area *area = &(zone->free_area[order]);
2009 page = list_first_entry_or_null(
2010 &area->free_list[MIGRATE_HIGHATOMIC],
2016 * It should never happen but changes to locking could
2017 * inadvertently allow a per-cpu drain to add pages
2018 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2019 * and watch for underflows.
2021 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
2022 zone->nr_reserved_highatomic);
2025 * Convert to ac->migratetype and avoid the normal
2026 * pageblock stealing heuristics. Minimally, the caller
2027 * is doing the work and needs the pages. More
2028 * importantly, if the block was always converted to
2029 * MIGRATE_UNMOVABLE or another type then the number
2030 * of pageblocks that cannot be completely freed
2033 set_pageblock_migratetype(page, ac->migratetype);
2034 move_freepages_block(zone, page, ac->migratetype);
2035 spin_unlock_irqrestore(&zone->lock, flags);
2038 spin_unlock_irqrestore(&zone->lock, flags);
2042 /* Remove an element from the buddy allocator from the fallback list */
2043 static inline struct page *
2044 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
2046 struct free_area *area;
2047 unsigned int current_order;
2052 /* Find the largest possible block of pages in the other list */
2053 for (current_order = MAX_ORDER-1;
2054 current_order >= order && current_order <= MAX_ORDER-1;
2056 area = &(zone->free_area[current_order]);
2057 fallback_mt = find_suitable_fallback(area, current_order,
2058 start_migratetype, false, &can_steal);
2059 if (fallback_mt == -1)
2062 page = list_first_entry(&area->free_list[fallback_mt],
2065 steal_suitable_fallback(zone, page, start_migratetype);
2067 /* Remove the page from the freelists */
2069 list_del(&page->lru);
2070 rmv_page_order(page);
2072 expand(zone, page, order, current_order, area,
2075 * The pcppage_migratetype may differ from pageblock's
2076 * migratetype depending on the decisions in
2077 * find_suitable_fallback(). This is OK as long as it does not
2078 * differ for MIGRATE_CMA pageblocks. Those can be used as
2079 * fallback only via special __rmqueue_cma_fallback() function
2081 set_pcppage_migratetype(page, start_migratetype);
2083 trace_mm_page_alloc_extfrag(page, order, current_order,
2084 start_migratetype, fallback_mt);
2093 * Do the hard work of removing an element from the buddy allocator.
2094 * Call me with the zone->lock already held.
2096 static struct page *__rmqueue(struct zone *zone, unsigned int order,
2101 page = __rmqueue_smallest(zone, order, migratetype);
2102 if (unlikely(!page)) {
2103 if (migratetype == MIGRATE_MOVABLE)
2104 page = __rmqueue_cma_fallback(zone, order);
2107 page = __rmqueue_fallback(zone, order, migratetype);
2110 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2115 * Obtain a specified number of elements from the buddy allocator, all under
2116 * a single hold of the lock, for efficiency. Add them to the supplied list.
2117 * Returns the number of new pages which were placed at *list.
2119 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2120 unsigned long count, struct list_head *list,
2121 int migratetype, bool cold)
2125 spin_lock(&zone->lock);
2126 for (i = 0; i < count; ++i) {
2127 struct page *page = __rmqueue(zone, order, migratetype);
2128 if (unlikely(page == NULL))
2132 * Split buddy pages returned by expand() are received here
2133 * in physical page order. The page is added to the callers and
2134 * list and the list head then moves forward. From the callers
2135 * perspective, the linked list is ordered by page number in
2136 * some conditions. This is useful for IO devices that can
2137 * merge IO requests if the physical pages are ordered
2141 list_add(&page->lru, list);
2143 list_add_tail(&page->lru, list);
2145 if (is_migrate_cma(get_pcppage_migratetype(page)))
2146 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2149 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2150 spin_unlock(&zone->lock);
2156 * Called from the vmstat counter updater to drain pagesets of this
2157 * currently executing processor on remote nodes after they have
2160 * Note that this function must be called with the thread pinned to
2161 * a single processor.
2163 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2165 unsigned long flags;
2166 int to_drain, batch;
2168 local_irq_save(flags);
2169 batch = READ_ONCE(pcp->batch);
2170 to_drain = min(pcp->count, batch);
2172 free_pcppages_bulk(zone, to_drain, pcp);
2173 pcp->count -= to_drain;
2175 local_irq_restore(flags);
2180 * Drain pcplists of the indicated processor and zone.
2182 * The processor must either be the current processor and the
2183 * thread pinned to the current processor or a processor that
2186 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2188 unsigned long flags;
2189 struct per_cpu_pageset *pset;
2190 struct per_cpu_pages *pcp;
2192 local_irq_save(flags);
2193 pset = per_cpu_ptr(zone->pageset, cpu);
2197 free_pcppages_bulk(zone, pcp->count, pcp);
2200 local_irq_restore(flags);
2204 * Drain pcplists of all zones on the indicated processor.
2206 * The processor must either be the current processor and the
2207 * thread pinned to the current processor or a processor that
2210 static void drain_pages(unsigned int cpu)
2214 for_each_populated_zone(zone) {
2215 drain_pages_zone(cpu, zone);
2220 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2222 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2223 * the single zone's pages.
2225 void drain_local_pages(struct zone *zone)
2227 int cpu = smp_processor_id();
2230 drain_pages_zone(cpu, zone);
2236 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2238 * When zone parameter is non-NULL, spill just the single zone's pages.
2240 * Note that this code is protected against sending an IPI to an offline
2241 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2242 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2243 * nothing keeps CPUs from showing up after we populated the cpumask and
2244 * before the call to on_each_cpu_mask().
2246 void drain_all_pages(struct zone *zone)
2251 * Allocate in the BSS so we wont require allocation in
2252 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2254 static cpumask_t cpus_with_pcps;
2257 * We don't care about racing with CPU hotplug event
2258 * as offline notification will cause the notified
2259 * cpu to drain that CPU pcps and on_each_cpu_mask
2260 * disables preemption as part of its processing
2262 for_each_online_cpu(cpu) {
2263 struct per_cpu_pageset *pcp;
2265 bool has_pcps = false;
2268 pcp = per_cpu_ptr(zone->pageset, cpu);
2272 for_each_populated_zone(z) {
2273 pcp = per_cpu_ptr(z->pageset, cpu);
2274 if (pcp->pcp.count) {
2282 cpumask_set_cpu(cpu, &cpus_with_pcps);
2284 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2286 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2290 #ifdef CONFIG_HIBERNATION
2292 void mark_free_pages(struct zone *zone)
2294 unsigned long pfn, max_zone_pfn;
2295 unsigned long flags;
2296 unsigned int order, t;
2299 if (zone_is_empty(zone))
2302 spin_lock_irqsave(&zone->lock, flags);
2304 max_zone_pfn = zone_end_pfn(zone);
2305 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2306 if (pfn_valid(pfn)) {
2307 page = pfn_to_page(pfn);
2309 if (page_zone(page) != zone)
2312 if (!swsusp_page_is_forbidden(page))
2313 swsusp_unset_page_free(page);
2316 for_each_migratetype_order(order, t) {
2317 list_for_each_entry(page,
2318 &zone->free_area[order].free_list[t], lru) {
2321 pfn = page_to_pfn(page);
2322 for (i = 0; i < (1UL << order); i++)
2323 swsusp_set_page_free(pfn_to_page(pfn + i));
2326 spin_unlock_irqrestore(&zone->lock, flags);
2328 #endif /* CONFIG_PM */
2331 * Free a 0-order page
2332 * cold == true ? free a cold page : free a hot page
2334 void free_hot_cold_page(struct page *page, bool cold)
2336 struct zone *zone = page_zone(page);
2337 struct per_cpu_pages *pcp;
2338 unsigned long flags;
2339 unsigned long pfn = page_to_pfn(page);
2342 if (!free_pages_prepare(page, 0))
2345 migratetype = get_pfnblock_migratetype(page, pfn);
2346 set_pcppage_migratetype(page, migratetype);
2347 local_irq_save(flags);
2348 __count_vm_event(PGFREE);
2351 * We only track unmovable, reclaimable and movable on pcp lists.
2352 * Free ISOLATE pages back to the allocator because they are being
2353 * offlined but treat RESERVE as movable pages so we can get those
2354 * areas back if necessary. Otherwise, we may have to free
2355 * excessively into the page allocator
2357 if (migratetype >= MIGRATE_PCPTYPES) {
2358 if (unlikely(is_migrate_isolate(migratetype))) {
2359 free_one_page(zone, page, pfn, 0, migratetype);
2362 migratetype = MIGRATE_MOVABLE;
2365 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2367 list_add(&page->lru, &pcp->lists[migratetype]);
2369 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2371 if (pcp->count >= pcp->high) {
2372 unsigned long batch = READ_ONCE(pcp->batch);
2373 free_pcppages_bulk(zone, batch, pcp);
2374 pcp->count -= batch;
2378 local_irq_restore(flags);
2382 * Free a list of 0-order pages
2384 void free_hot_cold_page_list(struct list_head *list, bool cold)
2386 struct page *page, *next;
2388 list_for_each_entry_safe(page, next, list, lru) {
2389 trace_mm_page_free_batched(page, cold);
2390 free_hot_cold_page(page, cold);
2395 * split_page takes a non-compound higher-order page, and splits it into
2396 * n (1<<order) sub-pages: page[0..n]
2397 * Each sub-page must be freed individually.
2399 * Note: this is probably too low level an operation for use in drivers.
2400 * Please consult with lkml before using this in your driver.
2402 void split_page(struct page *page, unsigned int order)
2407 VM_BUG_ON_PAGE(PageCompound(page), page);
2408 VM_BUG_ON_PAGE(!page_count(page), page);
2410 #ifdef CONFIG_KMEMCHECK
2412 * Split shadow pages too, because free(page[0]) would
2413 * otherwise free the whole shadow.
2415 if (kmemcheck_page_is_tracked(page))
2416 split_page(virt_to_page(page[0].shadow), order);
2419 gfp_mask = get_page_owner_gfp(page);
2420 set_page_owner(page, 0, gfp_mask);
2421 for (i = 1; i < (1 << order); i++) {
2422 set_page_refcounted(page + i);
2423 set_page_owner(page + i, 0, gfp_mask);
2426 EXPORT_SYMBOL_GPL(split_page);
2428 int __isolate_free_page(struct page *page, unsigned int order)
2430 unsigned long watermark;
2434 BUG_ON(!PageBuddy(page));
2436 zone = page_zone(page);
2437 mt = get_pageblock_migratetype(page);
2439 if (!is_migrate_isolate(mt)) {
2440 /* Obey watermarks as if the page was being allocated */
2441 watermark = low_wmark_pages(zone) + (1 << order);
2442 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2445 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2448 /* Remove page from free list */
2449 list_del(&page->lru);
2450 zone->free_area[order].nr_free--;
2451 rmv_page_order(page);
2453 set_page_owner(page, order, __GFP_MOVABLE);
2455 /* Set the pageblock if the isolated page is at least a pageblock */
2456 if (order >= pageblock_order - 1) {
2457 struct page *endpage = page + (1 << order) - 1;
2458 for (; page < endpage; page += pageblock_nr_pages) {
2459 int mt = get_pageblock_migratetype(page);
2460 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2461 set_pageblock_migratetype(page,
2467 return 1UL << order;
2471 * Similar to split_page except the page is already free. As this is only
2472 * being used for migration, the migratetype of the block also changes.
2473 * As this is called with interrupts disabled, the caller is responsible
2474 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2477 * Note: this is probably too low level an operation for use in drivers.
2478 * Please consult with lkml before using this in your driver.
2480 int split_free_page(struct page *page)
2485 order = page_order(page);
2487 nr_pages = __isolate_free_page(page, order);
2491 /* Split into individual pages */
2492 set_page_refcounted(page);
2493 split_page(page, order);
2498 * Update NUMA hit/miss statistics
2500 * Must be called with interrupts disabled.
2502 * When __GFP_OTHER_NODE is set assume the node of the preferred
2503 * zone is the local node. This is useful for daemons who allocate
2504 * memory on behalf of other processes.
2506 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2510 int local_nid = numa_node_id();
2511 enum zone_stat_item local_stat = NUMA_LOCAL;
2513 if (unlikely(flags & __GFP_OTHER_NODE)) {
2514 local_stat = NUMA_OTHER;
2515 local_nid = preferred_zone->node;
2518 if (z->node == local_nid) {
2519 __inc_zone_state(z, NUMA_HIT);
2520 __inc_zone_state(z, local_stat);
2522 __inc_zone_state(z, NUMA_MISS);
2523 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2529 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2532 struct page *buffered_rmqueue(struct zone *preferred_zone,
2533 struct zone *zone, unsigned int order,
2534 gfp_t gfp_flags, unsigned int alloc_flags,
2537 unsigned long flags;
2539 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2541 if (likely(order == 0)) {
2542 struct per_cpu_pages *pcp;
2543 struct list_head *list;
2545 local_irq_save(flags);
2546 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2547 list = &pcp->lists[migratetype];
2548 if (list_empty(list)) {
2549 pcp->count += rmqueue_bulk(zone, 0,
2552 if (unlikely(list_empty(list)))
2557 page = list_last_entry(list, struct page, lru);
2559 page = list_first_entry(list, struct page, lru);
2561 __dec_zone_state(zone, NR_ALLOC_BATCH);
2562 list_del(&page->lru);
2566 * We most definitely don't want callers attempting to
2567 * allocate greater than order-1 page units with __GFP_NOFAIL.
2569 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2570 spin_lock_irqsave(&zone->lock, flags);
2573 if (alloc_flags & ALLOC_HARDER) {
2574 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2576 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2579 page = __rmqueue(zone, order, migratetype);
2580 spin_unlock(&zone->lock);
2583 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2584 __mod_zone_freepage_state(zone, -(1 << order),
2585 get_pcppage_migratetype(page));
2588 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2589 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2590 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2592 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2593 zone_statistics(preferred_zone, zone, gfp_flags);
2594 local_irq_restore(flags);
2596 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2600 local_irq_restore(flags);
2604 #ifdef CONFIG_FAIL_PAGE_ALLOC
2607 struct fault_attr attr;
2609 bool ignore_gfp_highmem;
2610 bool ignore_gfp_reclaim;
2612 } fail_page_alloc = {
2613 .attr = FAULT_ATTR_INITIALIZER,
2614 .ignore_gfp_reclaim = true,
2615 .ignore_gfp_highmem = true,
2619 static int __init setup_fail_page_alloc(char *str)
2621 return setup_fault_attr(&fail_page_alloc.attr, str);
2623 __setup("fail_page_alloc=", setup_fail_page_alloc);
2625 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2627 if (order < fail_page_alloc.min_order)
2629 if (gfp_mask & __GFP_NOFAIL)
2631 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2633 if (fail_page_alloc.ignore_gfp_reclaim &&
2634 (gfp_mask & __GFP_DIRECT_RECLAIM))
2637 return should_fail(&fail_page_alloc.attr, 1 << order);
2640 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2642 static int __init fail_page_alloc_debugfs(void)
2644 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2647 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2648 &fail_page_alloc.attr);
2650 return PTR_ERR(dir);
2652 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2653 &fail_page_alloc.ignore_gfp_reclaim))
2655 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2656 &fail_page_alloc.ignore_gfp_highmem))
2658 if (!debugfs_create_u32("min-order", mode, dir,
2659 &fail_page_alloc.min_order))
2664 debugfs_remove_recursive(dir);
2669 late_initcall(fail_page_alloc_debugfs);
2671 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2673 #else /* CONFIG_FAIL_PAGE_ALLOC */
2675 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2680 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2683 * Return true if free base pages are above 'mark'. For high-order checks it
2684 * will return true of the order-0 watermark is reached and there is at least
2685 * one free page of a suitable size. Checking now avoids taking the zone lock
2686 * to check in the allocation paths if no pages are free.
2688 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2689 unsigned long mark, int classzone_idx,
2690 unsigned int alloc_flags,
2695 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2697 /* free_pages may go negative - that's OK */
2698 free_pages -= (1 << order) - 1;
2700 if (alloc_flags & ALLOC_HIGH)
2704 * If the caller does not have rights to ALLOC_HARDER then subtract
2705 * the high-atomic reserves. This will over-estimate the size of the
2706 * atomic reserve but it avoids a search.
2708 if (likely(!alloc_harder))
2709 free_pages -= z->nr_reserved_highatomic;
2714 /* If allocation can't use CMA areas don't use free CMA pages */
2715 if (!(alloc_flags & ALLOC_CMA))
2716 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2720 * Check watermarks for an order-0 allocation request. If these
2721 * are not met, then a high-order request also cannot go ahead
2722 * even if a suitable page happened to be free.
2724 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2727 /* If this is an order-0 request then the watermark is fine */
2731 /* For a high-order request, check at least one suitable page is free */
2732 for (o = order; o < MAX_ORDER; o++) {
2733 struct free_area *area = &z->free_area[o];
2742 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2743 if (!list_empty(&area->free_list[mt]))
2748 if ((alloc_flags & ALLOC_CMA) &&
2749 !list_empty(&area->free_list[MIGRATE_CMA])) {
2757 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2758 int classzone_idx, unsigned int alloc_flags)
2760 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2761 zone_page_state(z, NR_FREE_PAGES));
2764 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2765 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2767 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2771 /* If allocation can't use CMA areas don't use free CMA pages */
2772 if (!(alloc_flags & ALLOC_CMA))
2773 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2777 * Fast check for order-0 only. If this fails then the reserves
2778 * need to be calculated. There is a corner case where the check
2779 * passes but only the high-order atomic reserve are free. If
2780 * the caller is !atomic then it'll uselessly search the free
2781 * list. That corner case is then slower but it is harmless.
2783 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2786 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2790 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2791 unsigned long mark, int classzone_idx)
2793 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2795 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2796 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2798 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2803 static bool zone_local(struct zone *local_zone, struct zone *zone)
2805 return local_zone->node == zone->node;
2808 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2810 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2813 #else /* CONFIG_NUMA */
2814 static bool zone_local(struct zone *local_zone, struct zone *zone)
2819 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2823 #endif /* CONFIG_NUMA */
2825 static void reset_alloc_batches(struct zone *preferred_zone)
2827 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2830 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2831 high_wmark_pages(zone) - low_wmark_pages(zone) -
2832 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2833 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2834 } while (zone++ != preferred_zone);
2838 * get_page_from_freelist goes through the zonelist trying to allocate
2841 static struct page *
2842 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2843 const struct alloc_context *ac)
2845 struct zoneref *z = ac->preferred_zoneref;
2847 bool fair_skipped = false;
2848 bool apply_fair = (alloc_flags & ALLOC_FAIR);
2852 * Scan zonelist, looking for a zone with enough free.
2853 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2855 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
2860 if (cpusets_enabled() &&
2861 (alloc_flags & ALLOC_CPUSET) &&
2862 !__cpuset_zone_allowed(zone, gfp_mask))
2865 * Distribute pages in proportion to the individual
2866 * zone size to ensure fair page aging. The zone a
2867 * page was allocated in should have no effect on the
2868 * time the page has in memory before being reclaimed.
2871 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2872 fair_skipped = true;
2875 if (!zone_local(ac->preferred_zoneref->zone, zone)) {
2882 * When allocating a page cache page for writing, we
2883 * want to get it from a zone that is within its dirty
2884 * limit, such that no single zone holds more than its
2885 * proportional share of globally allowed dirty pages.
2886 * The dirty limits take into account the zone's
2887 * lowmem reserves and high watermark so that kswapd
2888 * should be able to balance it without having to
2889 * write pages from its LRU list.
2891 * This may look like it could increase pressure on
2892 * lower zones by failing allocations in higher zones
2893 * before they are full. But the pages that do spill
2894 * over are limited as the lower zones are protected
2895 * by this very same mechanism. It should not become
2896 * a practical burden to them.
2898 * XXX: For now, allow allocations to potentially
2899 * exceed the per-zone dirty limit in the slowpath
2900 * (spread_dirty_pages unset) before going into reclaim,
2901 * which is important when on a NUMA setup the allowed
2902 * zones are together not big enough to reach the
2903 * global limit. The proper fix for these situations
2904 * will require awareness of zones in the
2905 * dirty-throttling and the flusher threads.
2907 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2910 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2911 if (!zone_watermark_fast(zone, order, mark,
2912 ac_classzone_idx(ac), alloc_flags)) {
2915 /* Checked here to keep the fast path fast */
2916 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2917 if (alloc_flags & ALLOC_NO_WATERMARKS)
2920 if (zone_reclaim_mode == 0 ||
2921 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
2924 ret = zone_reclaim(zone, gfp_mask, order);
2926 case ZONE_RECLAIM_NOSCAN:
2929 case ZONE_RECLAIM_FULL:
2930 /* scanned but unreclaimable */
2933 /* did we reclaim enough */
2934 if (zone_watermark_ok(zone, order, mark,
2935 ac_classzone_idx(ac), alloc_flags))
2943 page = buffered_rmqueue(ac->preferred_zoneref->zone, zone, order,
2944 gfp_mask, alloc_flags, ac->migratetype);
2946 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2950 * If this is a high-order atomic allocation then check
2951 * if the pageblock should be reserved for the future
2953 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2954 reserve_highatomic_pageblock(page, zone, order);
2961 * The first pass makes sure allocations are spread fairly within the
2962 * local node. However, the local node might have free pages left
2963 * after the fairness batches are exhausted, and remote zones haven't
2964 * even been considered yet. Try once more without fairness, and
2965 * include remote zones now, before entering the slowpath and waking
2966 * kswapd: prefer spilling to a remote zone over swapping locally.
2971 fair_skipped = false;
2972 reset_alloc_batches(ac->preferred_zoneref->zone);
2980 * Large machines with many possible nodes should not always dump per-node
2981 * meminfo in irq context.
2983 static inline bool should_suppress_show_mem(void)
2988 ret = in_interrupt();
2993 static DEFINE_RATELIMIT_STATE(nopage_rs,
2994 DEFAULT_RATELIMIT_INTERVAL,
2995 DEFAULT_RATELIMIT_BURST);
2997 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
2999 unsigned int filter = SHOW_MEM_FILTER_NODES;
3001 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
3002 debug_guardpage_minorder() > 0)
3006 * This documents exceptions given to allocations in certain
3007 * contexts that are allowed to allocate outside current's set
3010 if (!(gfp_mask & __GFP_NOMEMALLOC))
3011 if (test_thread_flag(TIF_MEMDIE) ||
3012 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3013 filter &= ~SHOW_MEM_FILTER_NODES;
3014 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3015 filter &= ~SHOW_MEM_FILTER_NODES;
3018 struct va_format vaf;
3021 va_start(args, fmt);
3026 pr_warn("%pV", &vaf);
3031 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3032 current->comm, order, gfp_mask, &gfp_mask);
3034 if (!should_suppress_show_mem())
3038 static inline struct page *
3039 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3040 const struct alloc_context *ac, unsigned long *did_some_progress)
3042 struct oom_control oc = {
3043 .zonelist = ac->zonelist,
3044 .nodemask = ac->nodemask,
3045 .gfp_mask = gfp_mask,
3050 *did_some_progress = 0;
3053 * Acquire the oom lock. If that fails, somebody else is
3054 * making progress for us.
3056 if (!mutex_trylock(&oom_lock)) {
3057 *did_some_progress = 1;
3058 schedule_timeout_uninterruptible(1);
3063 * Go through the zonelist yet one more time, keep very high watermark
3064 * here, this is only to catch a parallel oom killing, we must fail if
3065 * we're still under heavy pressure.
3067 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3068 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3072 if (!(gfp_mask & __GFP_NOFAIL)) {
3073 /* Coredumps can quickly deplete all memory reserves */
3074 if (current->flags & PF_DUMPCORE)
3076 /* The OOM killer will not help higher order allocs */
3077 if (order > PAGE_ALLOC_COSTLY_ORDER)
3079 /* The OOM killer does not needlessly kill tasks for lowmem */
3080 if (ac->high_zoneidx < ZONE_NORMAL)
3082 if (pm_suspended_storage())
3085 * XXX: GFP_NOFS allocations should rather fail than rely on
3086 * other request to make a forward progress.
3087 * We are in an unfortunate situation where out_of_memory cannot
3088 * do much for this context but let's try it to at least get
3089 * access to memory reserved if the current task is killed (see
3090 * out_of_memory). Once filesystems are ready to handle allocation
3091 * failures more gracefully we should just bail out here.
3094 /* The OOM killer may not free memory on a specific node */
3095 if (gfp_mask & __GFP_THISNODE)
3098 /* Exhausted what can be done so it's blamo time */
3099 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3100 *did_some_progress = 1;
3102 if (gfp_mask & __GFP_NOFAIL) {
3103 page = get_page_from_freelist(gfp_mask, order,
3104 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
3106 * fallback to ignore cpuset restriction if our nodes
3110 page = get_page_from_freelist(gfp_mask, order,
3111 ALLOC_NO_WATERMARKS, ac);
3115 mutex_unlock(&oom_lock);
3119 #ifdef CONFIG_COMPACTION
3120 /* Try memory compaction for high-order allocations before reclaim */
3121 static struct page *
3122 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3123 unsigned int alloc_flags, const struct alloc_context *ac,
3124 enum migrate_mode mode, int *contended_compaction,
3125 bool *deferred_compaction)
3127 unsigned long compact_result;
3133 current->flags |= PF_MEMALLOC;
3134 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3135 mode, contended_compaction);
3136 current->flags &= ~PF_MEMALLOC;
3138 switch (compact_result) {
3139 case COMPACT_DEFERRED:
3140 *deferred_compaction = true;
3142 case COMPACT_SKIPPED:
3149 * At least in one zone compaction wasn't deferred or skipped, so let's
3150 * count a compaction stall
3152 count_vm_event(COMPACTSTALL);
3154 page = get_page_from_freelist(gfp_mask, order,
3155 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3158 struct zone *zone = page_zone(page);
3160 zone->compact_blockskip_flush = false;
3161 compaction_defer_reset(zone, order, true);
3162 count_vm_event(COMPACTSUCCESS);
3167 * It's bad if compaction run occurs and fails. The most likely reason
3168 * is that pages exist, but not enough to satisfy watermarks.
3170 count_vm_event(COMPACTFAIL);
3177 static inline struct page *
3178 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3179 unsigned int alloc_flags, const struct alloc_context *ac,
3180 enum migrate_mode mode, int *contended_compaction,
3181 bool *deferred_compaction)
3185 #endif /* CONFIG_COMPACTION */
3187 /* Perform direct synchronous page reclaim */
3189 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3190 const struct alloc_context *ac)
3192 struct reclaim_state reclaim_state;
3197 /* We now go into synchronous reclaim */
3198 cpuset_memory_pressure_bump();
3199 current->flags |= PF_MEMALLOC;
3200 lockdep_set_current_reclaim_state(gfp_mask);
3201 reclaim_state.reclaimed_slab = 0;
3202 current->reclaim_state = &reclaim_state;
3204 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3207 current->reclaim_state = NULL;
3208 lockdep_clear_current_reclaim_state();
3209 current->flags &= ~PF_MEMALLOC;
3216 /* The really slow allocator path where we enter direct reclaim */
3217 static inline struct page *
3218 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3219 unsigned int alloc_flags, const struct alloc_context *ac,
3220 unsigned long *did_some_progress)
3222 struct page *page = NULL;
3223 bool drained = false;
3225 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3226 if (unlikely(!(*did_some_progress)))
3230 page = get_page_from_freelist(gfp_mask, order,
3231 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3234 * If an allocation failed after direct reclaim, it could be because
3235 * pages are pinned on the per-cpu lists or in high alloc reserves.
3236 * Shrink them them and try again
3238 if (!page && !drained) {
3239 unreserve_highatomic_pageblock(ac);
3240 drain_all_pages(NULL);
3248 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3253 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3254 ac->high_zoneidx, ac->nodemask)
3255 wakeup_kswapd(zone, order, ac_classzone_idx(ac));
3258 static inline unsigned int
3259 gfp_to_alloc_flags(gfp_t gfp_mask)
3261 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3263 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3264 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3267 * The caller may dip into page reserves a bit more if the caller
3268 * cannot run direct reclaim, or if the caller has realtime scheduling
3269 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3270 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3272 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3274 if (gfp_mask & __GFP_ATOMIC) {
3276 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3277 * if it can't schedule.
3279 if (!(gfp_mask & __GFP_NOMEMALLOC))
3280 alloc_flags |= ALLOC_HARDER;
3282 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3283 * comment for __cpuset_node_allowed().
3285 alloc_flags &= ~ALLOC_CPUSET;
3286 } else if (unlikely(rt_task(current)) && !in_interrupt())
3287 alloc_flags |= ALLOC_HARDER;
3289 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3290 if (gfp_mask & __GFP_MEMALLOC)
3291 alloc_flags |= ALLOC_NO_WATERMARKS;
3292 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3293 alloc_flags |= ALLOC_NO_WATERMARKS;
3294 else if (!in_interrupt() &&
3295 ((current->flags & PF_MEMALLOC) ||
3296 unlikely(test_thread_flag(TIF_MEMDIE))))
3297 alloc_flags |= ALLOC_NO_WATERMARKS;
3300 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3301 alloc_flags |= ALLOC_CMA;
3306 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3308 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3311 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3313 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3316 static inline struct page *
3317 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3318 struct alloc_context *ac)
3320 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3321 struct page *page = NULL;
3322 unsigned int alloc_flags;
3323 unsigned long pages_reclaimed = 0;
3324 unsigned long did_some_progress;
3325 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3326 bool deferred_compaction = false;
3327 int contended_compaction = COMPACT_CONTENDED_NONE;
3330 * In the slowpath, we sanity check order to avoid ever trying to
3331 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3332 * be using allocators in order of preference for an area that is
3335 if (order >= MAX_ORDER) {
3336 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3341 * We also sanity check to catch abuse of atomic reserves being used by
3342 * callers that are not in atomic context.
3344 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3345 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3346 gfp_mask &= ~__GFP_ATOMIC;
3349 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3350 wake_all_kswapds(order, ac);
3353 * OK, we're below the kswapd watermark and have kicked background
3354 * reclaim. Now things get more complex, so set up alloc_flags according
3355 * to how we want to proceed.
3357 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3359 /* This is the last chance, in general, before the goto nopage. */
3360 page = get_page_from_freelist(gfp_mask, order,
3361 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3365 /* Allocate without watermarks if the context allows */
3366 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3368 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3369 * the allocation is high priority and these type of
3370 * allocations are system rather than user orientated
3372 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3373 page = get_page_from_freelist(gfp_mask, order,
3374 ALLOC_NO_WATERMARKS, ac);
3379 /* Caller is not willing to reclaim, we can't balance anything */
3380 if (!can_direct_reclaim) {
3382 * All existing users of the __GFP_NOFAIL are blockable, so warn
3383 * of any new users that actually allow this type of allocation
3386 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3390 /* Avoid recursion of direct reclaim */
3391 if (current->flags & PF_MEMALLOC) {
3393 * __GFP_NOFAIL request from this context is rather bizarre
3394 * because we cannot reclaim anything and only can loop waiting
3395 * for somebody to do a work for us.
3397 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3404 /* Avoid allocations with no watermarks from looping endlessly */
3405 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3409 * Try direct compaction. The first pass is asynchronous. Subsequent
3410 * attempts after direct reclaim are synchronous
3412 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3414 &contended_compaction,
3415 &deferred_compaction);
3419 /* Checks for THP-specific high-order allocations */
3420 if (is_thp_gfp_mask(gfp_mask)) {
3422 * If compaction is deferred for high-order allocations, it is
3423 * because sync compaction recently failed. If this is the case
3424 * and the caller requested a THP allocation, we do not want
3425 * to heavily disrupt the system, so we fail the allocation
3426 * instead of entering direct reclaim.
3428 if (deferred_compaction)
3432 * In all zones where compaction was attempted (and not
3433 * deferred or skipped), lock contention has been detected.
3434 * For THP allocation we do not want to disrupt the others
3435 * so we fallback to base pages instead.
3437 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3441 * If compaction was aborted due to need_resched(), we do not
3442 * want to further increase allocation latency, unless it is
3443 * khugepaged trying to collapse.
3445 if (contended_compaction == COMPACT_CONTENDED_SCHED
3446 && !(current->flags & PF_KTHREAD))
3451 * It can become very expensive to allocate transparent hugepages at
3452 * fault, so use asynchronous memory compaction for THP unless it is
3453 * khugepaged trying to collapse.
3455 if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
3456 migration_mode = MIGRATE_SYNC_LIGHT;
3458 /* Try direct reclaim and then allocating */
3459 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3460 &did_some_progress);
3464 /* Do not loop if specifically requested */
3465 if (gfp_mask & __GFP_NORETRY)
3468 /* Keep reclaiming pages as long as there is reasonable progress */
3469 pages_reclaimed += did_some_progress;
3470 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3471 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3472 /* Wait for some write requests to complete then retry */
3473 wait_iff_congested(ac->preferred_zoneref->zone, BLK_RW_ASYNC, HZ/50);
3477 /* Reclaim has failed us, start killing things */
3478 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3482 /* Retry as long as the OOM killer is making progress */
3483 if (did_some_progress)
3488 * High-order allocations do not necessarily loop after
3489 * direct reclaim and reclaim/compaction depends on compaction
3490 * being called after reclaim so call directly if necessary
3492 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3494 &contended_compaction,
3495 &deferred_compaction);
3499 warn_alloc_failed(gfp_mask, order, NULL);
3505 * This is the 'heart' of the zoned buddy allocator.
3508 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3509 struct zonelist *zonelist, nodemask_t *nodemask)
3512 unsigned int cpuset_mems_cookie;
3513 unsigned int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR;
3514 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3515 struct alloc_context ac = {
3516 .high_zoneidx = gfp_zone(gfp_mask),
3517 .zonelist = zonelist,
3518 .nodemask = nodemask,
3519 .migratetype = gfpflags_to_migratetype(gfp_mask),
3522 if (cpusets_enabled()) {
3523 alloc_mask |= __GFP_HARDWALL;
3524 alloc_flags |= ALLOC_CPUSET;
3526 ac.nodemask = &cpuset_current_mems_allowed;
3529 gfp_mask &= gfp_allowed_mask;
3531 lockdep_trace_alloc(gfp_mask);
3533 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3535 if (should_fail_alloc_page(gfp_mask, order))
3539 * Check the zones suitable for the gfp_mask contain at least one
3540 * valid zone. It's possible to have an empty zonelist as a result
3541 * of __GFP_THISNODE and a memoryless node
3543 if (unlikely(!zonelist->_zonerefs->zone))
3546 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3547 alloc_flags |= ALLOC_CMA;
3550 cpuset_mems_cookie = read_mems_allowed_begin();
3552 /* Dirty zone balancing only done in the fast path */
3553 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3555 /* The preferred zone is used for statistics later */
3556 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3557 ac.high_zoneidx, ac.nodemask);
3558 if (!ac.preferred_zoneref) {
3563 /* First allocation attempt */
3564 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3569 * Runtime PM, block IO and its error handling path can deadlock
3570 * because I/O on the device might not complete.
3572 alloc_mask = memalloc_noio_flags(gfp_mask);
3573 ac.spread_dirty_pages = false;
3575 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3579 * When updating a task's mems_allowed, it is possible to race with
3580 * parallel threads in such a way that an allocation can fail while
3581 * the mask is being updated. If a page allocation is about to fail,
3582 * check if the cpuset changed during allocation and if so, retry.
3584 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3585 alloc_mask = gfp_mask;
3590 if (kmemcheck_enabled && page)
3591 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3593 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3597 EXPORT_SYMBOL(__alloc_pages_nodemask);
3600 * Common helper functions.
3602 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3607 * __get_free_pages() returns a 32-bit address, which cannot represent
3610 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3612 page = alloc_pages(gfp_mask, order);
3615 return (unsigned long) page_address(page);
3617 EXPORT_SYMBOL(__get_free_pages);
3619 unsigned long get_zeroed_page(gfp_t gfp_mask)
3621 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3623 EXPORT_SYMBOL(get_zeroed_page);
3625 void __free_pages(struct page *page, unsigned int order)
3627 if (put_page_testzero(page)) {
3629 free_hot_cold_page(page, false);
3631 __free_pages_ok(page, order);
3635 EXPORT_SYMBOL(__free_pages);
3637 void free_pages(unsigned long addr, unsigned int order)
3640 VM_BUG_ON(!virt_addr_valid((void *)addr));
3641 __free_pages(virt_to_page((void *)addr), order);
3645 EXPORT_SYMBOL(free_pages);
3649 * An arbitrary-length arbitrary-offset area of memory which resides
3650 * within a 0 or higher order page. Multiple fragments within that page
3651 * are individually refcounted, in the page's reference counter.
3653 * The page_frag functions below provide a simple allocation framework for
3654 * page fragments. This is used by the network stack and network device
3655 * drivers to provide a backing region of memory for use as either an
3656 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3658 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3661 struct page *page = NULL;
3662 gfp_t gfp = gfp_mask;
3664 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3665 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3667 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3668 PAGE_FRAG_CACHE_MAX_ORDER);
3669 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3671 if (unlikely(!page))
3672 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3674 nc->va = page ? page_address(page) : NULL;
3679 void *__alloc_page_frag(struct page_frag_cache *nc,
3680 unsigned int fragsz, gfp_t gfp_mask)
3682 unsigned int size = PAGE_SIZE;
3686 if (unlikely(!nc->va)) {
3688 page = __page_frag_refill(nc, gfp_mask);
3692 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3693 /* if size can vary use size else just use PAGE_SIZE */
3696 /* Even if we own the page, we do not use atomic_set().
3697 * This would break get_page_unless_zero() users.
3699 page_ref_add(page, size - 1);
3701 /* reset page count bias and offset to start of new frag */
3702 nc->pfmemalloc = page_is_pfmemalloc(page);
3703 nc->pagecnt_bias = size;
3707 offset = nc->offset - fragsz;
3708 if (unlikely(offset < 0)) {
3709 page = virt_to_page(nc->va);
3711 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3714 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3715 /* if size can vary use size else just use PAGE_SIZE */
3718 /* OK, page count is 0, we can safely set it */
3719 set_page_count(page, size);
3721 /* reset page count bias and offset to start of new frag */
3722 nc->pagecnt_bias = size;
3723 offset = size - fragsz;
3727 nc->offset = offset;
3729 return nc->va + offset;
3731 EXPORT_SYMBOL(__alloc_page_frag);
3734 * Frees a page fragment allocated out of either a compound or order 0 page.
3736 void __free_page_frag(void *addr)
3738 struct page *page = virt_to_head_page(addr);
3740 if (unlikely(put_page_testzero(page)))
3741 __free_pages_ok(page, compound_order(page));
3743 EXPORT_SYMBOL(__free_page_frag);
3746 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3747 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3748 * equivalent to alloc_pages.
3750 * It should be used when the caller would like to use kmalloc, but since the
3751 * allocation is large, it has to fall back to the page allocator.
3753 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3757 page = alloc_pages(gfp_mask, order);
3758 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3759 __free_pages(page, order);
3765 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3769 page = alloc_pages_node(nid, gfp_mask, order);
3770 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3771 __free_pages(page, order);
3778 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3781 void __free_kmem_pages(struct page *page, unsigned int order)
3783 memcg_kmem_uncharge(page, order);
3784 __free_pages(page, order);
3787 void free_kmem_pages(unsigned long addr, unsigned int order)
3790 VM_BUG_ON(!virt_addr_valid((void *)addr));
3791 __free_kmem_pages(virt_to_page((void *)addr), order);
3795 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3799 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3800 unsigned long used = addr + PAGE_ALIGN(size);
3802 split_page(virt_to_page((void *)addr), order);
3803 while (used < alloc_end) {
3808 return (void *)addr;
3812 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3813 * @size: the number of bytes to allocate
3814 * @gfp_mask: GFP flags for the allocation
3816 * This function is similar to alloc_pages(), except that it allocates the
3817 * minimum number of pages to satisfy the request. alloc_pages() can only
3818 * allocate memory in power-of-two pages.
3820 * This function is also limited by MAX_ORDER.
3822 * Memory allocated by this function must be released by free_pages_exact().
3824 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3826 unsigned int order = get_order(size);
3829 addr = __get_free_pages(gfp_mask, order);
3830 return make_alloc_exact(addr, order, size);
3832 EXPORT_SYMBOL(alloc_pages_exact);
3835 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3837 * @nid: the preferred node ID where memory should be allocated
3838 * @size: the number of bytes to allocate
3839 * @gfp_mask: GFP flags for the allocation
3841 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3844 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3846 unsigned int order = get_order(size);
3847 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3850 return make_alloc_exact((unsigned long)page_address(p), order, size);
3854 * free_pages_exact - release memory allocated via alloc_pages_exact()
3855 * @virt: the value returned by alloc_pages_exact.
3856 * @size: size of allocation, same value as passed to alloc_pages_exact().
3858 * Release the memory allocated by a previous call to alloc_pages_exact.
3860 void free_pages_exact(void *virt, size_t size)
3862 unsigned long addr = (unsigned long)virt;
3863 unsigned long end = addr + PAGE_ALIGN(size);
3865 while (addr < end) {
3870 EXPORT_SYMBOL(free_pages_exact);
3873 * nr_free_zone_pages - count number of pages beyond high watermark
3874 * @offset: The zone index of the highest zone
3876 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3877 * high watermark within all zones at or below a given zone index. For each
3878 * zone, the number of pages is calculated as:
3879 * managed_pages - high_pages
3881 static unsigned long nr_free_zone_pages(int offset)
3886 /* Just pick one node, since fallback list is circular */
3887 unsigned long sum = 0;
3889 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3891 for_each_zone_zonelist(zone, z, zonelist, offset) {
3892 unsigned long size = zone->managed_pages;
3893 unsigned long high = high_wmark_pages(zone);
3902 * nr_free_buffer_pages - count number of pages beyond high watermark
3904 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3905 * watermark within ZONE_DMA and ZONE_NORMAL.
3907 unsigned long nr_free_buffer_pages(void)
3909 return nr_free_zone_pages(gfp_zone(GFP_USER));
3911 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3914 * nr_free_pagecache_pages - count number of pages beyond high watermark
3916 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3917 * high watermark within all zones.
3919 unsigned long nr_free_pagecache_pages(void)
3921 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3924 static inline void show_node(struct zone *zone)
3926 if (IS_ENABLED(CONFIG_NUMA))
3927 printk("Node %d ", zone_to_nid(zone));
3930 long si_mem_available(void)
3933 unsigned long pagecache;
3934 unsigned long wmark_low = 0;
3935 unsigned long pages[NR_LRU_LISTS];
3939 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
3940 pages[lru] = global_page_state(NR_LRU_BASE + lru);
3943 wmark_low += zone->watermark[WMARK_LOW];
3946 * Estimate the amount of memory available for userspace allocations,
3947 * without causing swapping.
3949 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
3952 * Not all the page cache can be freed, otherwise the system will
3953 * start swapping. Assume at least half of the page cache, or the
3954 * low watermark worth of cache, needs to stay.
3956 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
3957 pagecache -= min(pagecache / 2, wmark_low);
3958 available += pagecache;
3961 * Part of the reclaimable slab consists of items that are in use,
3962 * and cannot be freed. Cap this estimate at the low watermark.
3964 available += global_page_state(NR_SLAB_RECLAIMABLE) -
3965 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
3971 EXPORT_SYMBOL_GPL(si_mem_available);
3973 void si_meminfo(struct sysinfo *val)
3975 val->totalram = totalram_pages;
3976 val->sharedram = global_page_state(NR_SHMEM);
3977 val->freeram = global_page_state(NR_FREE_PAGES);
3978 val->bufferram = nr_blockdev_pages();
3979 val->totalhigh = totalhigh_pages;
3980 val->freehigh = nr_free_highpages();
3981 val->mem_unit = PAGE_SIZE;
3984 EXPORT_SYMBOL(si_meminfo);
3987 void si_meminfo_node(struct sysinfo *val, int nid)
3989 int zone_type; /* needs to be signed */
3990 unsigned long managed_pages = 0;
3991 unsigned long managed_highpages = 0;
3992 unsigned long free_highpages = 0;
3993 pg_data_t *pgdat = NODE_DATA(nid);
3995 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3996 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3997 val->totalram = managed_pages;
3998 val->sharedram = node_page_state(nid, NR_SHMEM);
3999 val->freeram = node_page_state(nid, NR_FREE_PAGES);
4000 #ifdef CONFIG_HIGHMEM
4001 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4002 struct zone *zone = &pgdat->node_zones[zone_type];
4004 if (is_highmem(zone)) {
4005 managed_highpages += zone->managed_pages;
4006 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4009 val->totalhigh = managed_highpages;
4010 val->freehigh = free_highpages;
4012 val->totalhigh = managed_highpages;
4013 val->freehigh = free_highpages;
4015 val->mem_unit = PAGE_SIZE;
4020 * Determine whether the node should be displayed or not, depending on whether
4021 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4023 bool skip_free_areas_node(unsigned int flags, int nid)
4026 unsigned int cpuset_mems_cookie;
4028 if (!(flags & SHOW_MEM_FILTER_NODES))
4032 cpuset_mems_cookie = read_mems_allowed_begin();
4033 ret = !node_isset(nid, cpuset_current_mems_allowed);
4034 } while (read_mems_allowed_retry(cpuset_mems_cookie));
4039 #define K(x) ((x) << (PAGE_SHIFT-10))
4041 static void show_migration_types(unsigned char type)
4043 static const char types[MIGRATE_TYPES] = {
4044 [MIGRATE_UNMOVABLE] = 'U',
4045 [MIGRATE_MOVABLE] = 'M',
4046 [MIGRATE_RECLAIMABLE] = 'E',
4047 [MIGRATE_HIGHATOMIC] = 'H',
4049 [MIGRATE_CMA] = 'C',
4051 #ifdef CONFIG_MEMORY_ISOLATION
4052 [MIGRATE_ISOLATE] = 'I',
4055 char tmp[MIGRATE_TYPES + 1];
4059 for (i = 0; i < MIGRATE_TYPES; i++) {
4060 if (type & (1 << i))
4065 printk("(%s) ", tmp);
4069 * Show free area list (used inside shift_scroll-lock stuff)
4070 * We also calculate the percentage fragmentation. We do this by counting the
4071 * memory on each free list with the exception of the first item on the list.
4074 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4077 void show_free_areas(unsigned int filter)
4079 unsigned long free_pcp = 0;
4083 for_each_populated_zone(zone) {
4084 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4087 for_each_online_cpu(cpu)
4088 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4091 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4092 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4093 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4094 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4095 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4096 " free:%lu free_pcp:%lu free_cma:%lu\n",
4097 global_page_state(NR_ACTIVE_ANON),
4098 global_page_state(NR_INACTIVE_ANON),
4099 global_page_state(NR_ISOLATED_ANON),
4100 global_page_state(NR_ACTIVE_FILE),
4101 global_page_state(NR_INACTIVE_FILE),
4102 global_page_state(NR_ISOLATED_FILE),
4103 global_page_state(NR_UNEVICTABLE),
4104 global_page_state(NR_FILE_DIRTY),
4105 global_page_state(NR_WRITEBACK),
4106 global_page_state(NR_UNSTABLE_NFS),
4107 global_page_state(NR_SLAB_RECLAIMABLE),
4108 global_page_state(NR_SLAB_UNRECLAIMABLE),
4109 global_page_state(NR_FILE_MAPPED),
4110 global_page_state(NR_SHMEM),
4111 global_page_state(NR_PAGETABLE),
4112 global_page_state(NR_BOUNCE),
4113 global_page_state(NR_FREE_PAGES),
4115 global_page_state(NR_FREE_CMA_PAGES));
4117 for_each_populated_zone(zone) {
4120 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4124 for_each_online_cpu(cpu)
4125 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4133 " active_anon:%lukB"
4134 " inactive_anon:%lukB"
4135 " active_file:%lukB"
4136 " inactive_file:%lukB"
4137 " unevictable:%lukB"
4138 " isolated(anon):%lukB"
4139 " isolated(file):%lukB"
4147 " slab_reclaimable:%lukB"
4148 " slab_unreclaimable:%lukB"
4149 " kernel_stack:%lukB"
4156 " writeback_tmp:%lukB"
4157 " pages_scanned:%lu"
4158 " all_unreclaimable? %s"
4161 K(zone_page_state(zone, NR_FREE_PAGES)),
4162 K(min_wmark_pages(zone)),
4163 K(low_wmark_pages(zone)),
4164 K(high_wmark_pages(zone)),
4165 K(zone_page_state(zone, NR_ACTIVE_ANON)),
4166 K(zone_page_state(zone, NR_INACTIVE_ANON)),
4167 K(zone_page_state(zone, NR_ACTIVE_FILE)),
4168 K(zone_page_state(zone, NR_INACTIVE_FILE)),
4169 K(zone_page_state(zone, NR_UNEVICTABLE)),
4170 K(zone_page_state(zone, NR_ISOLATED_ANON)),
4171 K(zone_page_state(zone, NR_ISOLATED_FILE)),
4172 K(zone->present_pages),
4173 K(zone->managed_pages),
4174 K(zone_page_state(zone, NR_MLOCK)),
4175 K(zone_page_state(zone, NR_FILE_DIRTY)),
4176 K(zone_page_state(zone, NR_WRITEBACK)),
4177 K(zone_page_state(zone, NR_FILE_MAPPED)),
4178 K(zone_page_state(zone, NR_SHMEM)),
4179 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4180 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4181 zone_page_state(zone, NR_KERNEL_STACK) *
4183 K(zone_page_state(zone, NR_PAGETABLE)),
4184 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
4185 K(zone_page_state(zone, NR_BOUNCE)),
4187 K(this_cpu_read(zone->pageset->pcp.count)),
4188 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
4189 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
4190 K(zone_page_state(zone, NR_PAGES_SCANNED)),
4191 (!zone_reclaimable(zone) ? "yes" : "no")
4193 printk("lowmem_reserve[]:");
4194 for (i = 0; i < MAX_NR_ZONES; i++)
4195 printk(" %ld", zone->lowmem_reserve[i]);
4199 for_each_populated_zone(zone) {
4201 unsigned long nr[MAX_ORDER], flags, total = 0;
4202 unsigned char types[MAX_ORDER];
4204 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4207 printk("%s: ", zone->name);
4209 spin_lock_irqsave(&zone->lock, flags);
4210 for (order = 0; order < MAX_ORDER; order++) {
4211 struct free_area *area = &zone->free_area[order];
4214 nr[order] = area->nr_free;
4215 total += nr[order] << order;
4218 for (type = 0; type < MIGRATE_TYPES; type++) {
4219 if (!list_empty(&area->free_list[type]))
4220 types[order] |= 1 << type;
4223 spin_unlock_irqrestore(&zone->lock, flags);
4224 for (order = 0; order < MAX_ORDER; order++) {
4225 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4227 show_migration_types(types[order]);
4229 printk("= %lukB\n", K(total));
4232 hugetlb_show_meminfo();
4234 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4236 show_swap_cache_info();
4239 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4241 zoneref->zone = zone;
4242 zoneref->zone_idx = zone_idx(zone);
4246 * Builds allocation fallback zone lists.
4248 * Add all populated zones of a node to the zonelist.
4250 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4254 enum zone_type zone_type = MAX_NR_ZONES;
4258 zone = pgdat->node_zones + zone_type;
4259 if (populated_zone(zone)) {
4260 zoneref_set_zone(zone,
4261 &zonelist->_zonerefs[nr_zones++]);
4262 check_highest_zone(zone_type);
4264 } while (zone_type);
4272 * 0 = automatic detection of better ordering.
4273 * 1 = order by ([node] distance, -zonetype)
4274 * 2 = order by (-zonetype, [node] distance)
4276 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4277 * the same zonelist. So only NUMA can configure this param.
4279 #define ZONELIST_ORDER_DEFAULT 0
4280 #define ZONELIST_ORDER_NODE 1
4281 #define ZONELIST_ORDER_ZONE 2
4283 /* zonelist order in the kernel.
4284 * set_zonelist_order() will set this to NODE or ZONE.
4286 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4287 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4291 /* The value user specified ....changed by config */
4292 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4293 /* string for sysctl */
4294 #define NUMA_ZONELIST_ORDER_LEN 16
4295 char numa_zonelist_order[16] = "default";
4298 * interface for configure zonelist ordering.
4299 * command line option "numa_zonelist_order"
4300 * = "[dD]efault - default, automatic configuration.
4301 * = "[nN]ode - order by node locality, then by zone within node
4302 * = "[zZ]one - order by zone, then by locality within zone
4305 static int __parse_numa_zonelist_order(char *s)
4307 if (*s == 'd' || *s == 'D') {
4308 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4309 } else if (*s == 'n' || *s == 'N') {
4310 user_zonelist_order = ZONELIST_ORDER_NODE;
4311 } else if (*s == 'z' || *s == 'Z') {
4312 user_zonelist_order = ZONELIST_ORDER_ZONE;
4314 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4320 static __init int setup_numa_zonelist_order(char *s)
4327 ret = __parse_numa_zonelist_order(s);
4329 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4333 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4336 * sysctl handler for numa_zonelist_order
4338 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4339 void __user *buffer, size_t *length,
4342 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4344 static DEFINE_MUTEX(zl_order_mutex);
4346 mutex_lock(&zl_order_mutex);
4348 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4352 strcpy(saved_string, (char *)table->data);
4354 ret = proc_dostring(table, write, buffer, length, ppos);
4358 int oldval = user_zonelist_order;
4360 ret = __parse_numa_zonelist_order((char *)table->data);
4363 * bogus value. restore saved string
4365 strncpy((char *)table->data, saved_string,
4366 NUMA_ZONELIST_ORDER_LEN);
4367 user_zonelist_order = oldval;
4368 } else if (oldval != user_zonelist_order) {
4369 mutex_lock(&zonelists_mutex);
4370 build_all_zonelists(NULL, NULL);
4371 mutex_unlock(&zonelists_mutex);
4375 mutex_unlock(&zl_order_mutex);
4380 #define MAX_NODE_LOAD (nr_online_nodes)
4381 static int node_load[MAX_NUMNODES];
4384 * find_next_best_node - find the next node that should appear in a given node's fallback list
4385 * @node: node whose fallback list we're appending
4386 * @used_node_mask: nodemask_t of already used nodes
4388 * We use a number of factors to determine which is the next node that should
4389 * appear on a given node's fallback list. The node should not have appeared
4390 * already in @node's fallback list, and it should be the next closest node
4391 * according to the distance array (which contains arbitrary distance values
4392 * from each node to each node in the system), and should also prefer nodes
4393 * with no CPUs, since presumably they'll have very little allocation pressure
4394 * on them otherwise.
4395 * It returns -1 if no node is found.
4397 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4400 int min_val = INT_MAX;
4401 int best_node = NUMA_NO_NODE;
4402 const struct cpumask *tmp = cpumask_of_node(0);
4404 /* Use the local node if we haven't already */
4405 if (!node_isset(node, *used_node_mask)) {
4406 node_set(node, *used_node_mask);
4410 for_each_node_state(n, N_MEMORY) {
4412 /* Don't want a node to appear more than once */
4413 if (node_isset(n, *used_node_mask))
4416 /* Use the distance array to find the distance */
4417 val = node_distance(node, n);
4419 /* Penalize nodes under us ("prefer the next node") */
4422 /* Give preference to headless and unused nodes */
4423 tmp = cpumask_of_node(n);
4424 if (!cpumask_empty(tmp))
4425 val += PENALTY_FOR_NODE_WITH_CPUS;
4427 /* Slight preference for less loaded node */
4428 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4429 val += node_load[n];
4431 if (val < min_val) {
4438 node_set(best_node, *used_node_mask);
4445 * Build zonelists ordered by node and zones within node.
4446 * This results in maximum locality--normal zone overflows into local
4447 * DMA zone, if any--but risks exhausting DMA zone.
4449 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4452 struct zonelist *zonelist;
4454 zonelist = &pgdat->node_zonelists[0];
4455 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4457 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4458 zonelist->_zonerefs[j].zone = NULL;
4459 zonelist->_zonerefs[j].zone_idx = 0;
4463 * Build gfp_thisnode zonelists
4465 static void build_thisnode_zonelists(pg_data_t *pgdat)
4468 struct zonelist *zonelist;
4470 zonelist = &pgdat->node_zonelists[1];
4471 j = build_zonelists_node(pgdat, zonelist, 0);
4472 zonelist->_zonerefs[j].zone = NULL;
4473 zonelist->_zonerefs[j].zone_idx = 0;
4477 * Build zonelists ordered by zone and nodes within zones.
4478 * This results in conserving DMA zone[s] until all Normal memory is
4479 * exhausted, but results in overflowing to remote node while memory
4480 * may still exist in local DMA zone.
4482 static int node_order[MAX_NUMNODES];
4484 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4487 int zone_type; /* needs to be signed */
4489 struct zonelist *zonelist;
4491 zonelist = &pgdat->node_zonelists[0];
4493 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4494 for (j = 0; j < nr_nodes; j++) {
4495 node = node_order[j];
4496 z = &NODE_DATA(node)->node_zones[zone_type];
4497 if (populated_zone(z)) {
4499 &zonelist->_zonerefs[pos++]);
4500 check_highest_zone(zone_type);
4504 zonelist->_zonerefs[pos].zone = NULL;
4505 zonelist->_zonerefs[pos].zone_idx = 0;
4508 #if defined(CONFIG_64BIT)
4510 * Devices that require DMA32/DMA are relatively rare and do not justify a
4511 * penalty to every machine in case the specialised case applies. Default
4512 * to Node-ordering on 64-bit NUMA machines
4514 static int default_zonelist_order(void)
4516 return ZONELIST_ORDER_NODE;
4520 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4521 * by the kernel. If processes running on node 0 deplete the low memory zone
4522 * then reclaim will occur more frequency increasing stalls and potentially
4523 * be easier to OOM if a large percentage of the zone is under writeback or
4524 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4525 * Hence, default to zone ordering on 32-bit.
4527 static int default_zonelist_order(void)
4529 return ZONELIST_ORDER_ZONE;
4531 #endif /* CONFIG_64BIT */
4533 static void set_zonelist_order(void)
4535 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4536 current_zonelist_order = default_zonelist_order();
4538 current_zonelist_order = user_zonelist_order;
4541 static void build_zonelists(pg_data_t *pgdat)
4544 nodemask_t used_mask;
4545 int local_node, prev_node;
4546 struct zonelist *zonelist;
4547 unsigned int order = current_zonelist_order;
4549 /* initialize zonelists */
4550 for (i = 0; i < MAX_ZONELISTS; i++) {
4551 zonelist = pgdat->node_zonelists + i;
4552 zonelist->_zonerefs[0].zone = NULL;
4553 zonelist->_zonerefs[0].zone_idx = 0;
4556 /* NUMA-aware ordering of nodes */
4557 local_node = pgdat->node_id;
4558 load = nr_online_nodes;
4559 prev_node = local_node;
4560 nodes_clear(used_mask);
4562 memset(node_order, 0, sizeof(node_order));
4565 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4567 * We don't want to pressure a particular node.
4568 * So adding penalty to the first node in same
4569 * distance group to make it round-robin.
4571 if (node_distance(local_node, node) !=
4572 node_distance(local_node, prev_node))
4573 node_load[node] = load;
4577 if (order == ZONELIST_ORDER_NODE)
4578 build_zonelists_in_node_order(pgdat, node);
4580 node_order[i++] = node; /* remember order */
4583 if (order == ZONELIST_ORDER_ZONE) {
4584 /* calculate node order -- i.e., DMA last! */
4585 build_zonelists_in_zone_order(pgdat, i);
4588 build_thisnode_zonelists(pgdat);
4591 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4593 * Return node id of node used for "local" allocations.
4594 * I.e., first node id of first zone in arg node's generic zonelist.
4595 * Used for initializing percpu 'numa_mem', which is used primarily
4596 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4598 int local_memory_node(int node)
4602 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4603 gfp_zone(GFP_KERNEL),
4605 return z->zone->node;
4609 #else /* CONFIG_NUMA */
4611 static void set_zonelist_order(void)
4613 current_zonelist_order = ZONELIST_ORDER_ZONE;
4616 static void build_zonelists(pg_data_t *pgdat)
4618 int node, local_node;
4620 struct zonelist *zonelist;
4622 local_node = pgdat->node_id;
4624 zonelist = &pgdat->node_zonelists[0];
4625 j = build_zonelists_node(pgdat, zonelist, 0);
4628 * Now we build the zonelist so that it contains the zones
4629 * of all the other nodes.
4630 * We don't want to pressure a particular node, so when
4631 * building the zones for node N, we make sure that the
4632 * zones coming right after the local ones are those from
4633 * node N+1 (modulo N)
4635 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4636 if (!node_online(node))
4638 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4640 for (node = 0; node < local_node; node++) {
4641 if (!node_online(node))
4643 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4646 zonelist->_zonerefs[j].zone = NULL;
4647 zonelist->_zonerefs[j].zone_idx = 0;
4650 #endif /* CONFIG_NUMA */
4653 * Boot pageset table. One per cpu which is going to be used for all
4654 * zones and all nodes. The parameters will be set in such a way
4655 * that an item put on a list will immediately be handed over to
4656 * the buddy list. This is safe since pageset manipulation is done
4657 * with interrupts disabled.
4659 * The boot_pagesets must be kept even after bootup is complete for
4660 * unused processors and/or zones. They do play a role for bootstrapping
4661 * hotplugged processors.
4663 * zoneinfo_show() and maybe other functions do
4664 * not check if the processor is online before following the pageset pointer.
4665 * Other parts of the kernel may not check if the zone is available.
4667 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4668 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4669 static void setup_zone_pageset(struct zone *zone);
4672 * Global mutex to protect against size modification of zonelists
4673 * as well as to serialize pageset setup for the new populated zone.
4675 DEFINE_MUTEX(zonelists_mutex);
4677 /* return values int ....just for stop_machine() */
4678 static int __build_all_zonelists(void *data)
4682 pg_data_t *self = data;
4685 memset(node_load, 0, sizeof(node_load));
4688 if (self && !node_online(self->node_id)) {
4689 build_zonelists(self);
4692 for_each_online_node(nid) {
4693 pg_data_t *pgdat = NODE_DATA(nid);
4695 build_zonelists(pgdat);
4699 * Initialize the boot_pagesets that are going to be used
4700 * for bootstrapping processors. The real pagesets for
4701 * each zone will be allocated later when the per cpu
4702 * allocator is available.
4704 * boot_pagesets are used also for bootstrapping offline
4705 * cpus if the system is already booted because the pagesets
4706 * are needed to initialize allocators on a specific cpu too.
4707 * F.e. the percpu allocator needs the page allocator which
4708 * needs the percpu allocator in order to allocate its pagesets
4709 * (a chicken-egg dilemma).
4711 for_each_possible_cpu(cpu) {
4712 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4714 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4716 * We now know the "local memory node" for each node--
4717 * i.e., the node of the first zone in the generic zonelist.
4718 * Set up numa_mem percpu variable for on-line cpus. During
4719 * boot, only the boot cpu should be on-line; we'll init the
4720 * secondary cpus' numa_mem as they come on-line. During
4721 * node/memory hotplug, we'll fixup all on-line cpus.
4723 if (cpu_online(cpu))
4724 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4731 static noinline void __init
4732 build_all_zonelists_init(void)
4734 __build_all_zonelists(NULL);
4735 mminit_verify_zonelist();
4736 cpuset_init_current_mems_allowed();
4740 * Called with zonelists_mutex held always
4741 * unless system_state == SYSTEM_BOOTING.
4743 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4744 * [we're only called with non-NULL zone through __meminit paths] and
4745 * (2) call of __init annotated helper build_all_zonelists_init
4746 * [protected by SYSTEM_BOOTING].
4748 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4750 set_zonelist_order();
4752 if (system_state == SYSTEM_BOOTING) {
4753 build_all_zonelists_init();
4755 #ifdef CONFIG_MEMORY_HOTPLUG
4757 setup_zone_pageset(zone);
4759 /* we have to stop all cpus to guarantee there is no user
4761 stop_machine(__build_all_zonelists, pgdat, NULL);
4762 /* cpuset refresh routine should be here */
4764 vm_total_pages = nr_free_pagecache_pages();
4766 * Disable grouping by mobility if the number of pages in the
4767 * system is too low to allow the mechanism to work. It would be
4768 * more accurate, but expensive to check per-zone. This check is
4769 * made on memory-hotadd so a system can start with mobility
4770 * disabled and enable it later
4772 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4773 page_group_by_mobility_disabled = 1;
4775 page_group_by_mobility_disabled = 0;
4777 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4779 zonelist_order_name[current_zonelist_order],
4780 page_group_by_mobility_disabled ? "off" : "on",
4783 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4788 * Helper functions to size the waitqueue hash table.
4789 * Essentially these want to choose hash table sizes sufficiently
4790 * large so that collisions trying to wait on pages are rare.
4791 * But in fact, the number of active page waitqueues on typical
4792 * systems is ridiculously low, less than 200. So this is even
4793 * conservative, even though it seems large.
4795 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4796 * waitqueues, i.e. the size of the waitq table given the number of pages.
4798 #define PAGES_PER_WAITQUEUE 256
4800 #ifndef CONFIG_MEMORY_HOTPLUG
4801 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4803 unsigned long size = 1;
4805 pages /= PAGES_PER_WAITQUEUE;
4807 while (size < pages)
4811 * Once we have dozens or even hundreds of threads sleeping
4812 * on IO we've got bigger problems than wait queue collision.
4813 * Limit the size of the wait table to a reasonable size.
4815 size = min(size, 4096UL);
4817 return max(size, 4UL);
4821 * A zone's size might be changed by hot-add, so it is not possible to determine
4822 * a suitable size for its wait_table. So we use the maximum size now.
4824 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4826 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4827 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4828 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4830 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4831 * or more by the traditional way. (See above). It equals:
4833 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4834 * ia64(16K page size) : = ( 8G + 4M)byte.
4835 * powerpc (64K page size) : = (32G +16M)byte.
4837 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4844 * This is an integer logarithm so that shifts can be used later
4845 * to extract the more random high bits from the multiplicative
4846 * hash function before the remainder is taken.
4848 static inline unsigned long wait_table_bits(unsigned long size)
4854 * Initially all pages are reserved - free ones are freed
4855 * up by free_all_bootmem() once the early boot process is
4856 * done. Non-atomic initialization, single-pass.
4858 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4859 unsigned long start_pfn, enum memmap_context context)
4861 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
4862 unsigned long end_pfn = start_pfn + size;
4863 pg_data_t *pgdat = NODE_DATA(nid);
4865 unsigned long nr_initialised = 0;
4866 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4867 struct memblock_region *r = NULL, *tmp;
4870 if (highest_memmap_pfn < end_pfn - 1)
4871 highest_memmap_pfn = end_pfn - 1;
4874 * Honor reservation requested by the driver for this ZONE_DEVICE
4877 if (altmap && start_pfn == altmap->base_pfn)
4878 start_pfn += altmap->reserve;
4880 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4882 * There can be holes in boot-time mem_map[]s handed to this
4883 * function. They do not exist on hotplugged memory.
4885 if (context != MEMMAP_EARLY)
4888 if (!early_pfn_valid(pfn))
4890 if (!early_pfn_in_nid(pfn, nid))
4892 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
4895 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4897 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4898 * from zone_movable_pfn[nid] to end of each node should be
4899 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4901 if (!mirrored_kernelcore && zone_movable_pfn[nid])
4902 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
4906 * Check given memblock attribute by firmware which can affect
4907 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4908 * mirrored, it's an overlapped memmap init. skip it.
4910 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
4911 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
4912 for_each_memblock(memory, tmp)
4913 if (pfn < memblock_region_memory_end_pfn(tmp))
4917 if (pfn >= memblock_region_memory_base_pfn(r) &&
4918 memblock_is_mirror(r)) {
4919 /* already initialized as NORMAL */
4920 pfn = memblock_region_memory_end_pfn(r);
4928 * Mark the block movable so that blocks are reserved for
4929 * movable at startup. This will force kernel allocations
4930 * to reserve their blocks rather than leaking throughout
4931 * the address space during boot when many long-lived
4932 * kernel allocations are made.
4934 * bitmap is created for zone's valid pfn range. but memmap
4935 * can be created for invalid pages (for alignment)
4936 * check here not to call set_pageblock_migratetype() against
4939 if (!(pfn & (pageblock_nr_pages - 1))) {
4940 struct page *page = pfn_to_page(pfn);
4942 __init_single_page(page, pfn, zone, nid);
4943 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4945 __init_single_pfn(pfn, zone, nid);
4950 static void __meminit zone_init_free_lists(struct zone *zone)
4952 unsigned int order, t;
4953 for_each_migratetype_order(order, t) {
4954 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4955 zone->free_area[order].nr_free = 0;
4959 #ifndef __HAVE_ARCH_MEMMAP_INIT
4960 #define memmap_init(size, nid, zone, start_pfn) \
4961 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4964 static int zone_batchsize(struct zone *zone)
4970 * The per-cpu-pages pools are set to around 1000th of the
4971 * size of the zone. But no more than 1/2 of a meg.
4973 * OK, so we don't know how big the cache is. So guess.
4975 batch = zone->managed_pages / 1024;
4976 if (batch * PAGE_SIZE > 512 * 1024)
4977 batch = (512 * 1024) / PAGE_SIZE;
4978 batch /= 4; /* We effectively *= 4 below */
4983 * Clamp the batch to a 2^n - 1 value. Having a power
4984 * of 2 value was found to be more likely to have
4985 * suboptimal cache aliasing properties in some cases.
4987 * For example if 2 tasks are alternately allocating
4988 * batches of pages, one task can end up with a lot
4989 * of pages of one half of the possible page colors
4990 * and the other with pages of the other colors.
4992 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4997 /* The deferral and batching of frees should be suppressed under NOMMU
5000 * The problem is that NOMMU needs to be able to allocate large chunks
5001 * of contiguous memory as there's no hardware page translation to
5002 * assemble apparent contiguous memory from discontiguous pages.
5004 * Queueing large contiguous runs of pages for batching, however,
5005 * causes the pages to actually be freed in smaller chunks. As there
5006 * can be a significant delay between the individual batches being
5007 * recycled, this leads to the once large chunks of space being
5008 * fragmented and becoming unavailable for high-order allocations.
5015 * pcp->high and pcp->batch values are related and dependent on one another:
5016 * ->batch must never be higher then ->high.
5017 * The following function updates them in a safe manner without read side
5020 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5021 * those fields changing asynchronously (acording the the above rule).
5023 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5024 * outside of boot time (or some other assurance that no concurrent updaters
5027 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5028 unsigned long batch)
5030 /* start with a fail safe value for batch */
5034 /* Update high, then batch, in order */
5041 /* a companion to pageset_set_high() */
5042 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5044 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5047 static void pageset_init(struct per_cpu_pageset *p)
5049 struct per_cpu_pages *pcp;
5052 memset(p, 0, sizeof(*p));
5056 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5057 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5060 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5063 pageset_set_batch(p, batch);
5067 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5068 * to the value high for the pageset p.
5070 static void pageset_set_high(struct per_cpu_pageset *p,
5073 unsigned long batch = max(1UL, high / 4);
5074 if ((high / 4) > (PAGE_SHIFT * 8))
5075 batch = PAGE_SHIFT * 8;
5077 pageset_update(&p->pcp, high, batch);
5080 static void pageset_set_high_and_batch(struct zone *zone,
5081 struct per_cpu_pageset *pcp)
5083 if (percpu_pagelist_fraction)
5084 pageset_set_high(pcp,
5085 (zone->managed_pages /
5086 percpu_pagelist_fraction));
5088 pageset_set_batch(pcp, zone_batchsize(zone));
5091 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5093 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5096 pageset_set_high_and_batch(zone, pcp);
5099 static void __meminit setup_zone_pageset(struct zone *zone)
5102 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5103 for_each_possible_cpu(cpu)
5104 zone_pageset_init(zone, cpu);
5108 * Allocate per cpu pagesets and initialize them.
5109 * Before this call only boot pagesets were available.
5111 void __init setup_per_cpu_pageset(void)
5115 for_each_populated_zone(zone)
5116 setup_zone_pageset(zone);
5119 static noinline __init_refok
5120 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
5126 * The per-page waitqueue mechanism uses hashed waitqueues
5129 zone->wait_table_hash_nr_entries =
5130 wait_table_hash_nr_entries(zone_size_pages);
5131 zone->wait_table_bits =
5132 wait_table_bits(zone->wait_table_hash_nr_entries);
5133 alloc_size = zone->wait_table_hash_nr_entries
5134 * sizeof(wait_queue_head_t);
5136 if (!slab_is_available()) {
5137 zone->wait_table = (wait_queue_head_t *)
5138 memblock_virt_alloc_node_nopanic(
5139 alloc_size, zone->zone_pgdat->node_id);
5142 * This case means that a zone whose size was 0 gets new memory
5143 * via memory hot-add.
5144 * But it may be the case that a new node was hot-added. In
5145 * this case vmalloc() will not be able to use this new node's
5146 * memory - this wait_table must be initialized to use this new
5147 * node itself as well.
5148 * To use this new node's memory, further consideration will be
5151 zone->wait_table = vmalloc(alloc_size);
5153 if (!zone->wait_table)
5156 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
5157 init_waitqueue_head(zone->wait_table + i);
5162 static __meminit void zone_pcp_init(struct zone *zone)
5165 * per cpu subsystem is not up at this point. The following code
5166 * relies on the ability of the linker to provide the
5167 * offset of a (static) per cpu variable into the per cpu area.
5169 zone->pageset = &boot_pageset;
5171 if (populated_zone(zone))
5172 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5173 zone->name, zone->present_pages,
5174 zone_batchsize(zone));
5177 int __meminit init_currently_empty_zone(struct zone *zone,
5178 unsigned long zone_start_pfn,
5181 struct pglist_data *pgdat = zone->zone_pgdat;
5183 ret = zone_wait_table_init(zone, size);
5186 pgdat->nr_zones = zone_idx(zone) + 1;
5188 zone->zone_start_pfn = zone_start_pfn;
5190 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5191 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5193 (unsigned long)zone_idx(zone),
5194 zone_start_pfn, (zone_start_pfn + size));
5196 zone_init_free_lists(zone);
5201 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5202 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5205 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5207 int __meminit __early_pfn_to_nid(unsigned long pfn,
5208 struct mminit_pfnnid_cache *state)
5210 unsigned long start_pfn, end_pfn;
5213 if (state->last_start <= pfn && pfn < state->last_end)
5214 return state->last_nid;
5216 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5218 state->last_start = start_pfn;
5219 state->last_end = end_pfn;
5220 state->last_nid = nid;
5225 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5228 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5229 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5230 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5232 * If an architecture guarantees that all ranges registered contain no holes
5233 * and may be freed, this this function may be used instead of calling
5234 * memblock_free_early_nid() manually.
5236 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5238 unsigned long start_pfn, end_pfn;
5241 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5242 start_pfn = min(start_pfn, max_low_pfn);
5243 end_pfn = min(end_pfn, max_low_pfn);
5245 if (start_pfn < end_pfn)
5246 memblock_free_early_nid(PFN_PHYS(start_pfn),
5247 (end_pfn - start_pfn) << PAGE_SHIFT,
5253 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5254 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5256 * If an architecture guarantees that all ranges registered contain no holes and may
5257 * be freed, this function may be used instead of calling memory_present() manually.
5259 void __init sparse_memory_present_with_active_regions(int nid)
5261 unsigned long start_pfn, end_pfn;
5264 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5265 memory_present(this_nid, start_pfn, end_pfn);
5269 * get_pfn_range_for_nid - Return the start and end page frames for a node
5270 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5271 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5272 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5274 * It returns the start and end page frame of a node based on information
5275 * provided by memblock_set_node(). If called for a node
5276 * with no available memory, a warning is printed and the start and end
5279 void __meminit get_pfn_range_for_nid(unsigned int nid,
5280 unsigned long *start_pfn, unsigned long *end_pfn)
5282 unsigned long this_start_pfn, this_end_pfn;
5288 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5289 *start_pfn = min(*start_pfn, this_start_pfn);
5290 *end_pfn = max(*end_pfn, this_end_pfn);
5293 if (*start_pfn == -1UL)
5298 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5299 * assumption is made that zones within a node are ordered in monotonic
5300 * increasing memory addresses so that the "highest" populated zone is used
5302 static void __init find_usable_zone_for_movable(void)
5305 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5306 if (zone_index == ZONE_MOVABLE)
5309 if (arch_zone_highest_possible_pfn[zone_index] >
5310 arch_zone_lowest_possible_pfn[zone_index])
5314 VM_BUG_ON(zone_index == -1);
5315 movable_zone = zone_index;
5319 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5320 * because it is sized independent of architecture. Unlike the other zones,
5321 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5322 * in each node depending on the size of each node and how evenly kernelcore
5323 * is distributed. This helper function adjusts the zone ranges
5324 * provided by the architecture for a given node by using the end of the
5325 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5326 * zones within a node are in order of monotonic increases memory addresses
5328 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5329 unsigned long zone_type,
5330 unsigned long node_start_pfn,
5331 unsigned long node_end_pfn,
5332 unsigned long *zone_start_pfn,
5333 unsigned long *zone_end_pfn)
5335 /* Only adjust if ZONE_MOVABLE is on this node */
5336 if (zone_movable_pfn[nid]) {
5337 /* Size ZONE_MOVABLE */
5338 if (zone_type == ZONE_MOVABLE) {
5339 *zone_start_pfn = zone_movable_pfn[nid];
5340 *zone_end_pfn = min(node_end_pfn,
5341 arch_zone_highest_possible_pfn[movable_zone]);
5343 /* Check if this whole range is within ZONE_MOVABLE */
5344 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5345 *zone_start_pfn = *zone_end_pfn;
5350 * Return the number of pages a zone spans in a node, including holes
5351 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5353 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5354 unsigned long zone_type,
5355 unsigned long node_start_pfn,
5356 unsigned long node_end_pfn,
5357 unsigned long *zone_start_pfn,
5358 unsigned long *zone_end_pfn,
5359 unsigned long *ignored)
5361 /* When hotadd a new node from cpu_up(), the node should be empty */
5362 if (!node_start_pfn && !node_end_pfn)
5365 /* Get the start and end of the zone */
5366 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5367 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5368 adjust_zone_range_for_zone_movable(nid, zone_type,
5369 node_start_pfn, node_end_pfn,
5370 zone_start_pfn, zone_end_pfn);
5372 /* Check that this node has pages within the zone's required range */
5373 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5376 /* Move the zone boundaries inside the node if necessary */
5377 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5378 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5380 /* Return the spanned pages */
5381 return *zone_end_pfn - *zone_start_pfn;
5385 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5386 * then all holes in the requested range will be accounted for.
5388 unsigned long __meminit __absent_pages_in_range(int nid,
5389 unsigned long range_start_pfn,
5390 unsigned long range_end_pfn)
5392 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5393 unsigned long start_pfn, end_pfn;
5396 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5397 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5398 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5399 nr_absent -= end_pfn - start_pfn;
5405 * absent_pages_in_range - Return number of page frames in holes within a range
5406 * @start_pfn: The start PFN to start searching for holes
5407 * @end_pfn: The end PFN to stop searching for holes
5409 * It returns the number of pages frames in memory holes within a range.
5411 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5412 unsigned long end_pfn)
5414 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5417 /* Return the number of page frames in holes in a zone on a node */
5418 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5419 unsigned long zone_type,
5420 unsigned long node_start_pfn,
5421 unsigned long node_end_pfn,
5422 unsigned long *ignored)
5424 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5425 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5426 unsigned long zone_start_pfn, zone_end_pfn;
5427 unsigned long nr_absent;
5429 /* When hotadd a new node from cpu_up(), the node should be empty */
5430 if (!node_start_pfn && !node_end_pfn)
5433 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5434 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5436 adjust_zone_range_for_zone_movable(nid, zone_type,
5437 node_start_pfn, node_end_pfn,
5438 &zone_start_pfn, &zone_end_pfn);
5439 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5442 * ZONE_MOVABLE handling.
5443 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5446 if (zone_movable_pfn[nid]) {
5447 if (mirrored_kernelcore) {
5448 unsigned long start_pfn, end_pfn;
5449 struct memblock_region *r;
5451 for_each_memblock(memory, r) {
5452 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5453 zone_start_pfn, zone_end_pfn);
5454 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5455 zone_start_pfn, zone_end_pfn);
5457 if (zone_type == ZONE_MOVABLE &&
5458 memblock_is_mirror(r))
5459 nr_absent += end_pfn - start_pfn;
5461 if (zone_type == ZONE_NORMAL &&
5462 !memblock_is_mirror(r))
5463 nr_absent += end_pfn - start_pfn;
5466 if (zone_type == ZONE_NORMAL)
5467 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5474 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5475 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5476 unsigned long zone_type,
5477 unsigned long node_start_pfn,
5478 unsigned long node_end_pfn,
5479 unsigned long *zone_start_pfn,
5480 unsigned long *zone_end_pfn,
5481 unsigned long *zones_size)
5485 *zone_start_pfn = node_start_pfn;
5486 for (zone = 0; zone < zone_type; zone++)
5487 *zone_start_pfn += zones_size[zone];
5489 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5491 return zones_size[zone_type];
5494 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5495 unsigned long zone_type,
5496 unsigned long node_start_pfn,
5497 unsigned long node_end_pfn,
5498 unsigned long *zholes_size)
5503 return zholes_size[zone_type];
5506 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5508 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5509 unsigned long node_start_pfn,
5510 unsigned long node_end_pfn,
5511 unsigned long *zones_size,
5512 unsigned long *zholes_size)
5514 unsigned long realtotalpages = 0, totalpages = 0;
5517 for (i = 0; i < MAX_NR_ZONES; i++) {
5518 struct zone *zone = pgdat->node_zones + i;
5519 unsigned long zone_start_pfn, zone_end_pfn;
5520 unsigned long size, real_size;
5522 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5528 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5529 node_start_pfn, node_end_pfn,
5532 zone->zone_start_pfn = zone_start_pfn;
5534 zone->zone_start_pfn = 0;
5535 zone->spanned_pages = size;
5536 zone->present_pages = real_size;
5539 realtotalpages += real_size;
5542 pgdat->node_spanned_pages = totalpages;
5543 pgdat->node_present_pages = realtotalpages;
5544 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5548 #ifndef CONFIG_SPARSEMEM
5550 * Calculate the size of the zone->blockflags rounded to an unsigned long
5551 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5552 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5553 * round what is now in bits to nearest long in bits, then return it in
5556 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5558 unsigned long usemapsize;
5560 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5561 usemapsize = roundup(zonesize, pageblock_nr_pages);
5562 usemapsize = usemapsize >> pageblock_order;
5563 usemapsize *= NR_PAGEBLOCK_BITS;
5564 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5566 return usemapsize / 8;
5569 static void __init setup_usemap(struct pglist_data *pgdat,
5571 unsigned long zone_start_pfn,
5572 unsigned long zonesize)
5574 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5575 zone->pageblock_flags = NULL;
5577 zone->pageblock_flags =
5578 memblock_virt_alloc_node_nopanic(usemapsize,
5582 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5583 unsigned long zone_start_pfn, unsigned long zonesize) {}
5584 #endif /* CONFIG_SPARSEMEM */
5586 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5588 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5589 void __paginginit set_pageblock_order(void)
5593 /* Check that pageblock_nr_pages has not already been setup */
5594 if (pageblock_order)
5597 if (HPAGE_SHIFT > PAGE_SHIFT)
5598 order = HUGETLB_PAGE_ORDER;
5600 order = MAX_ORDER - 1;
5603 * Assume the largest contiguous order of interest is a huge page.
5604 * This value may be variable depending on boot parameters on IA64 and
5607 pageblock_order = order;
5609 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5612 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5613 * is unused as pageblock_order is set at compile-time. See
5614 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5617 void __paginginit set_pageblock_order(void)
5621 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5623 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5624 unsigned long present_pages)
5626 unsigned long pages = spanned_pages;
5629 * Provide a more accurate estimation if there are holes within
5630 * the zone and SPARSEMEM is in use. If there are holes within the
5631 * zone, each populated memory region may cost us one or two extra
5632 * memmap pages due to alignment because memmap pages for each
5633 * populated regions may not naturally algined on page boundary.
5634 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5636 if (spanned_pages > present_pages + (present_pages >> 4) &&
5637 IS_ENABLED(CONFIG_SPARSEMEM))
5638 pages = present_pages;
5640 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5644 * Set up the zone data structures:
5645 * - mark all pages reserved
5646 * - mark all memory queues empty
5647 * - clear the memory bitmaps
5649 * NOTE: pgdat should get zeroed by caller.
5651 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5654 int nid = pgdat->node_id;
5657 pgdat_resize_init(pgdat);
5658 #ifdef CONFIG_NUMA_BALANCING
5659 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5660 pgdat->numabalancing_migrate_nr_pages = 0;
5661 pgdat->numabalancing_migrate_next_window = jiffies;
5663 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5664 spin_lock_init(&pgdat->split_queue_lock);
5665 INIT_LIST_HEAD(&pgdat->split_queue);
5666 pgdat->split_queue_len = 0;
5668 init_waitqueue_head(&pgdat->kswapd_wait);
5669 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5670 #ifdef CONFIG_COMPACTION
5671 init_waitqueue_head(&pgdat->kcompactd_wait);
5673 pgdat_page_ext_init(pgdat);
5675 for (j = 0; j < MAX_NR_ZONES; j++) {
5676 struct zone *zone = pgdat->node_zones + j;
5677 unsigned long size, realsize, freesize, memmap_pages;
5678 unsigned long zone_start_pfn = zone->zone_start_pfn;
5680 size = zone->spanned_pages;
5681 realsize = freesize = zone->present_pages;
5684 * Adjust freesize so that it accounts for how much memory
5685 * is used by this zone for memmap. This affects the watermark
5686 * and per-cpu initialisations
5688 memmap_pages = calc_memmap_size(size, realsize);
5689 if (!is_highmem_idx(j)) {
5690 if (freesize >= memmap_pages) {
5691 freesize -= memmap_pages;
5694 " %s zone: %lu pages used for memmap\n",
5695 zone_names[j], memmap_pages);
5697 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5698 zone_names[j], memmap_pages, freesize);
5701 /* Account for reserved pages */
5702 if (j == 0 && freesize > dma_reserve) {
5703 freesize -= dma_reserve;
5704 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5705 zone_names[0], dma_reserve);
5708 if (!is_highmem_idx(j))
5709 nr_kernel_pages += freesize;
5710 /* Charge for highmem memmap if there are enough kernel pages */
5711 else if (nr_kernel_pages > memmap_pages * 2)
5712 nr_kernel_pages -= memmap_pages;
5713 nr_all_pages += freesize;
5716 * Set an approximate value for lowmem here, it will be adjusted
5717 * when the bootmem allocator frees pages into the buddy system.
5718 * And all highmem pages will be managed by the buddy system.
5720 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5723 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5725 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5727 zone->name = zone_names[j];
5728 spin_lock_init(&zone->lock);
5729 spin_lock_init(&zone->lru_lock);
5730 zone_seqlock_init(zone);
5731 zone->zone_pgdat = pgdat;
5732 zone_pcp_init(zone);
5734 /* For bootup, initialized properly in watermark setup */
5735 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5737 lruvec_init(&zone->lruvec);
5741 set_pageblock_order();
5742 setup_usemap(pgdat, zone, zone_start_pfn, size);
5743 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5745 memmap_init(size, nid, j, zone_start_pfn);
5749 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5751 unsigned long __maybe_unused start = 0;
5752 unsigned long __maybe_unused offset = 0;
5754 /* Skip empty nodes */
5755 if (!pgdat->node_spanned_pages)
5758 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5759 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5760 offset = pgdat->node_start_pfn - start;
5761 /* ia64 gets its own node_mem_map, before this, without bootmem */
5762 if (!pgdat->node_mem_map) {
5763 unsigned long size, end;
5767 * The zone's endpoints aren't required to be MAX_ORDER
5768 * aligned but the node_mem_map endpoints must be in order
5769 * for the buddy allocator to function correctly.
5771 end = pgdat_end_pfn(pgdat);
5772 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5773 size = (end - start) * sizeof(struct page);
5774 map = alloc_remap(pgdat->node_id, size);
5776 map = memblock_virt_alloc_node_nopanic(size,
5778 pgdat->node_mem_map = map + offset;
5780 #ifndef CONFIG_NEED_MULTIPLE_NODES
5782 * With no DISCONTIG, the global mem_map is just set as node 0's
5784 if (pgdat == NODE_DATA(0)) {
5785 mem_map = NODE_DATA(0)->node_mem_map;
5786 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5787 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5789 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5792 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5795 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5796 unsigned long node_start_pfn, unsigned long *zholes_size)
5798 pg_data_t *pgdat = NODE_DATA(nid);
5799 unsigned long start_pfn = 0;
5800 unsigned long end_pfn = 0;
5802 /* pg_data_t should be reset to zero when it's allocated */
5803 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5805 reset_deferred_meminit(pgdat);
5806 pgdat->node_id = nid;
5807 pgdat->node_start_pfn = node_start_pfn;
5808 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5809 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5810 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5811 (u64)start_pfn << PAGE_SHIFT,
5812 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5814 start_pfn = node_start_pfn;
5816 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5817 zones_size, zholes_size);
5819 alloc_node_mem_map(pgdat);
5820 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5821 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5822 nid, (unsigned long)pgdat,
5823 (unsigned long)pgdat->node_mem_map);
5826 free_area_init_core(pgdat);
5829 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5831 #if MAX_NUMNODES > 1
5833 * Figure out the number of possible node ids.
5835 void __init setup_nr_node_ids(void)
5837 unsigned int highest;
5839 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5840 nr_node_ids = highest + 1;
5845 * node_map_pfn_alignment - determine the maximum internode alignment
5847 * This function should be called after node map is populated and sorted.
5848 * It calculates the maximum power of two alignment which can distinguish
5851 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5852 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5853 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5854 * shifted, 1GiB is enough and this function will indicate so.
5856 * This is used to test whether pfn -> nid mapping of the chosen memory
5857 * model has fine enough granularity to avoid incorrect mapping for the
5858 * populated node map.
5860 * Returns the determined alignment in pfn's. 0 if there is no alignment
5861 * requirement (single node).
5863 unsigned long __init node_map_pfn_alignment(void)
5865 unsigned long accl_mask = 0, last_end = 0;
5866 unsigned long start, end, mask;
5870 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5871 if (!start || last_nid < 0 || last_nid == nid) {
5878 * Start with a mask granular enough to pin-point to the
5879 * start pfn and tick off bits one-by-one until it becomes
5880 * too coarse to separate the current node from the last.
5882 mask = ~((1 << __ffs(start)) - 1);
5883 while (mask && last_end <= (start & (mask << 1)))
5886 /* accumulate all internode masks */
5890 /* convert mask to number of pages */
5891 return ~accl_mask + 1;
5894 /* Find the lowest pfn for a node */
5895 static unsigned long __init find_min_pfn_for_node(int nid)
5897 unsigned long min_pfn = ULONG_MAX;
5898 unsigned long start_pfn;
5901 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5902 min_pfn = min(min_pfn, start_pfn);
5904 if (min_pfn == ULONG_MAX) {
5905 pr_warn("Could not find start_pfn for node %d\n", nid);
5913 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5915 * It returns the minimum PFN based on information provided via
5916 * memblock_set_node().
5918 unsigned long __init find_min_pfn_with_active_regions(void)
5920 return find_min_pfn_for_node(MAX_NUMNODES);
5924 * early_calculate_totalpages()
5925 * Sum pages in active regions for movable zone.
5926 * Populate N_MEMORY for calculating usable_nodes.
5928 static unsigned long __init early_calculate_totalpages(void)
5930 unsigned long totalpages = 0;
5931 unsigned long start_pfn, end_pfn;
5934 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5935 unsigned long pages = end_pfn - start_pfn;
5937 totalpages += pages;
5939 node_set_state(nid, N_MEMORY);
5945 * Find the PFN the Movable zone begins in each node. Kernel memory
5946 * is spread evenly between nodes as long as the nodes have enough
5947 * memory. When they don't, some nodes will have more kernelcore than
5950 static void __init find_zone_movable_pfns_for_nodes(void)
5953 unsigned long usable_startpfn;
5954 unsigned long kernelcore_node, kernelcore_remaining;
5955 /* save the state before borrow the nodemask */
5956 nodemask_t saved_node_state = node_states[N_MEMORY];
5957 unsigned long totalpages = early_calculate_totalpages();
5958 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5959 struct memblock_region *r;
5961 /* Need to find movable_zone earlier when movable_node is specified. */
5962 find_usable_zone_for_movable();
5965 * If movable_node is specified, ignore kernelcore and movablecore
5968 if (movable_node_is_enabled()) {
5969 for_each_memblock(memory, r) {
5970 if (!memblock_is_hotpluggable(r))
5975 usable_startpfn = PFN_DOWN(r->base);
5976 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5977 min(usable_startpfn, zone_movable_pfn[nid]) :
5985 * If kernelcore=mirror is specified, ignore movablecore option
5987 if (mirrored_kernelcore) {
5988 bool mem_below_4gb_not_mirrored = false;
5990 for_each_memblock(memory, r) {
5991 if (memblock_is_mirror(r))
5996 usable_startpfn = memblock_region_memory_base_pfn(r);
5998 if (usable_startpfn < 0x100000) {
5999 mem_below_4gb_not_mirrored = true;
6003 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6004 min(usable_startpfn, zone_movable_pfn[nid]) :
6008 if (mem_below_4gb_not_mirrored)
6009 pr_warn("This configuration results in unmirrored kernel memory.");
6015 * If movablecore=nn[KMG] was specified, calculate what size of
6016 * kernelcore that corresponds so that memory usable for
6017 * any allocation type is evenly spread. If both kernelcore
6018 * and movablecore are specified, then the value of kernelcore
6019 * will be used for required_kernelcore if it's greater than
6020 * what movablecore would have allowed.
6022 if (required_movablecore) {
6023 unsigned long corepages;
6026 * Round-up so that ZONE_MOVABLE is at least as large as what
6027 * was requested by the user
6029 required_movablecore =
6030 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6031 required_movablecore = min(totalpages, required_movablecore);
6032 corepages = totalpages - required_movablecore;
6034 required_kernelcore = max(required_kernelcore, corepages);
6038 * If kernelcore was not specified or kernelcore size is larger
6039 * than totalpages, there is no ZONE_MOVABLE.
6041 if (!required_kernelcore || required_kernelcore >= totalpages)
6044 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6045 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6048 /* Spread kernelcore memory as evenly as possible throughout nodes */
6049 kernelcore_node = required_kernelcore / usable_nodes;
6050 for_each_node_state(nid, N_MEMORY) {
6051 unsigned long start_pfn, end_pfn;
6054 * Recalculate kernelcore_node if the division per node
6055 * now exceeds what is necessary to satisfy the requested
6056 * amount of memory for the kernel
6058 if (required_kernelcore < kernelcore_node)
6059 kernelcore_node = required_kernelcore / usable_nodes;
6062 * As the map is walked, we track how much memory is usable
6063 * by the kernel using kernelcore_remaining. When it is
6064 * 0, the rest of the node is usable by ZONE_MOVABLE
6066 kernelcore_remaining = kernelcore_node;
6068 /* Go through each range of PFNs within this node */
6069 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6070 unsigned long size_pages;
6072 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6073 if (start_pfn >= end_pfn)
6076 /* Account for what is only usable for kernelcore */
6077 if (start_pfn < usable_startpfn) {
6078 unsigned long kernel_pages;
6079 kernel_pages = min(end_pfn, usable_startpfn)
6082 kernelcore_remaining -= min(kernel_pages,
6083 kernelcore_remaining);
6084 required_kernelcore -= min(kernel_pages,
6085 required_kernelcore);
6087 /* Continue if range is now fully accounted */
6088 if (end_pfn <= usable_startpfn) {
6091 * Push zone_movable_pfn to the end so
6092 * that if we have to rebalance
6093 * kernelcore across nodes, we will
6094 * not double account here
6096 zone_movable_pfn[nid] = end_pfn;
6099 start_pfn = usable_startpfn;
6103 * The usable PFN range for ZONE_MOVABLE is from
6104 * start_pfn->end_pfn. Calculate size_pages as the
6105 * number of pages used as kernelcore
6107 size_pages = end_pfn - start_pfn;
6108 if (size_pages > kernelcore_remaining)
6109 size_pages = kernelcore_remaining;
6110 zone_movable_pfn[nid] = start_pfn + size_pages;
6113 * Some kernelcore has been met, update counts and
6114 * break if the kernelcore for this node has been
6117 required_kernelcore -= min(required_kernelcore,
6119 kernelcore_remaining -= size_pages;
6120 if (!kernelcore_remaining)
6126 * If there is still required_kernelcore, we do another pass with one
6127 * less node in the count. This will push zone_movable_pfn[nid] further
6128 * along on the nodes that still have memory until kernelcore is
6132 if (usable_nodes && required_kernelcore > usable_nodes)
6136 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6137 for (nid = 0; nid < MAX_NUMNODES; nid++)
6138 zone_movable_pfn[nid] =
6139 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6142 /* restore the node_state */
6143 node_states[N_MEMORY] = saved_node_state;
6146 /* Any regular or high memory on that node ? */
6147 static void check_for_memory(pg_data_t *pgdat, int nid)
6149 enum zone_type zone_type;
6151 if (N_MEMORY == N_NORMAL_MEMORY)
6154 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6155 struct zone *zone = &pgdat->node_zones[zone_type];
6156 if (populated_zone(zone)) {
6157 node_set_state(nid, N_HIGH_MEMORY);
6158 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6159 zone_type <= ZONE_NORMAL)
6160 node_set_state(nid, N_NORMAL_MEMORY);
6167 * free_area_init_nodes - Initialise all pg_data_t and zone data
6168 * @max_zone_pfn: an array of max PFNs for each zone
6170 * This will call free_area_init_node() for each active node in the system.
6171 * Using the page ranges provided by memblock_set_node(), the size of each
6172 * zone in each node and their holes is calculated. If the maximum PFN
6173 * between two adjacent zones match, it is assumed that the zone is empty.
6174 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6175 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6176 * starts where the previous one ended. For example, ZONE_DMA32 starts
6177 * at arch_max_dma_pfn.
6179 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6181 unsigned long start_pfn, end_pfn;
6184 /* Record where the zone boundaries are */
6185 memset(arch_zone_lowest_possible_pfn, 0,
6186 sizeof(arch_zone_lowest_possible_pfn));
6187 memset(arch_zone_highest_possible_pfn, 0,
6188 sizeof(arch_zone_highest_possible_pfn));
6189 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
6190 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
6191 for (i = 1; i < MAX_NR_ZONES; i++) {
6192 if (i == ZONE_MOVABLE)
6194 arch_zone_lowest_possible_pfn[i] =
6195 arch_zone_highest_possible_pfn[i-1];
6196 arch_zone_highest_possible_pfn[i] =
6197 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
6199 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6200 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6202 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6203 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6204 find_zone_movable_pfns_for_nodes();
6206 /* Print out the zone ranges */
6207 pr_info("Zone ranges:\n");
6208 for (i = 0; i < MAX_NR_ZONES; i++) {
6209 if (i == ZONE_MOVABLE)
6211 pr_info(" %-8s ", zone_names[i]);
6212 if (arch_zone_lowest_possible_pfn[i] ==
6213 arch_zone_highest_possible_pfn[i])
6216 pr_cont("[mem %#018Lx-%#018Lx]\n",
6217 (u64)arch_zone_lowest_possible_pfn[i]
6219 ((u64)arch_zone_highest_possible_pfn[i]
6220 << PAGE_SHIFT) - 1);
6223 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6224 pr_info("Movable zone start for each node\n");
6225 for (i = 0; i < MAX_NUMNODES; i++) {
6226 if (zone_movable_pfn[i])
6227 pr_info(" Node %d: %#018Lx\n", i,
6228 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6231 /* Print out the early node map */
6232 pr_info("Early memory node ranges\n");
6233 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6234 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6235 (u64)start_pfn << PAGE_SHIFT,
6236 ((u64)end_pfn << PAGE_SHIFT) - 1);
6238 /* Initialise every node */
6239 mminit_verify_pageflags_layout();
6240 setup_nr_node_ids();
6241 for_each_online_node(nid) {
6242 pg_data_t *pgdat = NODE_DATA(nid);
6243 free_area_init_node(nid, NULL,
6244 find_min_pfn_for_node(nid), NULL);
6246 /* Any memory on that node */
6247 if (pgdat->node_present_pages)
6248 node_set_state(nid, N_MEMORY);
6249 check_for_memory(pgdat, nid);
6253 static int __init cmdline_parse_core(char *p, unsigned long *core)
6255 unsigned long long coremem;
6259 coremem = memparse(p, &p);
6260 *core = coremem >> PAGE_SHIFT;
6262 /* Paranoid check that UL is enough for the coremem value */
6263 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6269 * kernelcore=size sets the amount of memory for use for allocations that
6270 * cannot be reclaimed or migrated.
6272 static int __init cmdline_parse_kernelcore(char *p)
6274 /* parse kernelcore=mirror */
6275 if (parse_option_str(p, "mirror")) {
6276 mirrored_kernelcore = true;
6280 return cmdline_parse_core(p, &required_kernelcore);
6284 * movablecore=size sets the amount of memory for use for allocations that
6285 * can be reclaimed or migrated.
6287 static int __init cmdline_parse_movablecore(char *p)
6289 return cmdline_parse_core(p, &required_movablecore);
6292 early_param("kernelcore", cmdline_parse_kernelcore);
6293 early_param("movablecore", cmdline_parse_movablecore);
6295 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6297 void adjust_managed_page_count(struct page *page, long count)
6299 spin_lock(&managed_page_count_lock);
6300 page_zone(page)->managed_pages += count;
6301 totalram_pages += count;
6302 #ifdef CONFIG_HIGHMEM
6303 if (PageHighMem(page))
6304 totalhigh_pages += count;
6306 spin_unlock(&managed_page_count_lock);
6308 EXPORT_SYMBOL(adjust_managed_page_count);
6310 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6313 unsigned long pages = 0;
6315 start = (void *)PAGE_ALIGN((unsigned long)start);
6316 end = (void *)((unsigned long)end & PAGE_MASK);
6317 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6318 if ((unsigned int)poison <= 0xFF)
6319 memset(pos, poison, PAGE_SIZE);
6320 free_reserved_page(virt_to_page(pos));
6324 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6325 s, pages << (PAGE_SHIFT - 10), start, end);
6329 EXPORT_SYMBOL(free_reserved_area);
6331 #ifdef CONFIG_HIGHMEM
6332 void free_highmem_page(struct page *page)
6334 __free_reserved_page(page);
6336 page_zone(page)->managed_pages++;
6342 void __init mem_init_print_info(const char *str)
6344 unsigned long physpages, codesize, datasize, rosize, bss_size;
6345 unsigned long init_code_size, init_data_size;
6347 physpages = get_num_physpages();
6348 codesize = _etext - _stext;
6349 datasize = _edata - _sdata;
6350 rosize = __end_rodata - __start_rodata;
6351 bss_size = __bss_stop - __bss_start;
6352 init_data_size = __init_end - __init_begin;
6353 init_code_size = _einittext - _sinittext;
6356 * Detect special cases and adjust section sizes accordingly:
6357 * 1) .init.* may be embedded into .data sections
6358 * 2) .init.text.* may be out of [__init_begin, __init_end],
6359 * please refer to arch/tile/kernel/vmlinux.lds.S.
6360 * 3) .rodata.* may be embedded into .text or .data sections.
6362 #define adj_init_size(start, end, size, pos, adj) \
6364 if (start <= pos && pos < end && size > adj) \
6368 adj_init_size(__init_begin, __init_end, init_data_size,
6369 _sinittext, init_code_size);
6370 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6371 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6372 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6373 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6375 #undef adj_init_size
6377 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6378 #ifdef CONFIG_HIGHMEM
6382 nr_free_pages() << (PAGE_SHIFT - 10),
6383 physpages << (PAGE_SHIFT - 10),
6384 codesize >> 10, datasize >> 10, rosize >> 10,
6385 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6386 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6387 totalcma_pages << (PAGE_SHIFT - 10),
6388 #ifdef CONFIG_HIGHMEM
6389 totalhigh_pages << (PAGE_SHIFT - 10),
6391 str ? ", " : "", str ? str : "");
6395 * set_dma_reserve - set the specified number of pages reserved in the first zone
6396 * @new_dma_reserve: The number of pages to mark reserved
6398 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6399 * In the DMA zone, a significant percentage may be consumed by kernel image
6400 * and other unfreeable allocations which can skew the watermarks badly. This
6401 * function may optionally be used to account for unfreeable pages in the
6402 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6403 * smaller per-cpu batchsize.
6405 void __init set_dma_reserve(unsigned long new_dma_reserve)
6407 dma_reserve = new_dma_reserve;
6410 void __init free_area_init(unsigned long *zones_size)
6412 free_area_init_node(0, zones_size,
6413 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6416 static int page_alloc_cpu_notify(struct notifier_block *self,
6417 unsigned long action, void *hcpu)
6419 int cpu = (unsigned long)hcpu;
6421 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6422 lru_add_drain_cpu(cpu);
6426 * Spill the event counters of the dead processor
6427 * into the current processors event counters.
6428 * This artificially elevates the count of the current
6431 vm_events_fold_cpu(cpu);
6434 * Zero the differential counters of the dead processor
6435 * so that the vm statistics are consistent.
6437 * This is only okay since the processor is dead and cannot
6438 * race with what we are doing.
6440 cpu_vm_stats_fold(cpu);
6445 void __init page_alloc_init(void)
6447 hotcpu_notifier(page_alloc_cpu_notify, 0);
6451 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6452 * or min_free_kbytes changes.
6454 static void calculate_totalreserve_pages(void)
6456 struct pglist_data *pgdat;
6457 unsigned long reserve_pages = 0;
6458 enum zone_type i, j;
6460 for_each_online_pgdat(pgdat) {
6461 for (i = 0; i < MAX_NR_ZONES; i++) {
6462 struct zone *zone = pgdat->node_zones + i;
6465 /* Find valid and maximum lowmem_reserve in the zone */
6466 for (j = i; j < MAX_NR_ZONES; j++) {
6467 if (zone->lowmem_reserve[j] > max)
6468 max = zone->lowmem_reserve[j];
6471 /* we treat the high watermark as reserved pages. */
6472 max += high_wmark_pages(zone);
6474 if (max > zone->managed_pages)
6475 max = zone->managed_pages;
6477 zone->totalreserve_pages = max;
6479 reserve_pages += max;
6482 totalreserve_pages = reserve_pages;
6486 * setup_per_zone_lowmem_reserve - called whenever
6487 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6488 * has a correct pages reserved value, so an adequate number of
6489 * pages are left in the zone after a successful __alloc_pages().
6491 static void setup_per_zone_lowmem_reserve(void)
6493 struct pglist_data *pgdat;
6494 enum zone_type j, idx;
6496 for_each_online_pgdat(pgdat) {
6497 for (j = 0; j < MAX_NR_ZONES; j++) {
6498 struct zone *zone = pgdat->node_zones + j;
6499 unsigned long managed_pages = zone->managed_pages;
6501 zone->lowmem_reserve[j] = 0;
6505 struct zone *lower_zone;
6509 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6510 sysctl_lowmem_reserve_ratio[idx] = 1;
6512 lower_zone = pgdat->node_zones + idx;
6513 lower_zone->lowmem_reserve[j] = managed_pages /
6514 sysctl_lowmem_reserve_ratio[idx];
6515 managed_pages += lower_zone->managed_pages;
6520 /* update totalreserve_pages */
6521 calculate_totalreserve_pages();
6524 static void __setup_per_zone_wmarks(void)
6526 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6527 unsigned long lowmem_pages = 0;
6529 unsigned long flags;
6531 /* Calculate total number of !ZONE_HIGHMEM pages */
6532 for_each_zone(zone) {
6533 if (!is_highmem(zone))
6534 lowmem_pages += zone->managed_pages;
6537 for_each_zone(zone) {
6540 spin_lock_irqsave(&zone->lock, flags);
6541 tmp = (u64)pages_min * zone->managed_pages;
6542 do_div(tmp, lowmem_pages);
6543 if (is_highmem(zone)) {
6545 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6546 * need highmem pages, so cap pages_min to a small
6549 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6550 * deltas control asynch page reclaim, and so should
6551 * not be capped for highmem.
6553 unsigned long min_pages;
6555 min_pages = zone->managed_pages / 1024;
6556 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6557 zone->watermark[WMARK_MIN] = min_pages;
6560 * If it's a lowmem zone, reserve a number of pages
6561 * proportionate to the zone's size.
6563 zone->watermark[WMARK_MIN] = tmp;
6567 * Set the kswapd watermarks distance according to the
6568 * scale factor in proportion to available memory, but
6569 * ensure a minimum size on small systems.
6571 tmp = max_t(u64, tmp >> 2,
6572 mult_frac(zone->managed_pages,
6573 watermark_scale_factor, 10000));
6575 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6576 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6578 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6579 high_wmark_pages(zone) - low_wmark_pages(zone) -
6580 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6582 spin_unlock_irqrestore(&zone->lock, flags);
6585 /* update totalreserve_pages */
6586 calculate_totalreserve_pages();
6590 * setup_per_zone_wmarks - called when min_free_kbytes changes
6591 * or when memory is hot-{added|removed}
6593 * Ensures that the watermark[min,low,high] values for each zone are set
6594 * correctly with respect to min_free_kbytes.
6596 void setup_per_zone_wmarks(void)
6598 mutex_lock(&zonelists_mutex);
6599 __setup_per_zone_wmarks();
6600 mutex_unlock(&zonelists_mutex);
6604 * The inactive anon list should be small enough that the VM never has to
6605 * do too much work, but large enough that each inactive page has a chance
6606 * to be referenced again before it is swapped out.
6608 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6609 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6610 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6611 * the anonymous pages are kept on the inactive list.
6614 * memory ratio inactive anon
6615 * -------------------------------------
6624 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6626 unsigned int gb, ratio;
6628 /* Zone size in gigabytes */
6629 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6631 ratio = int_sqrt(10 * gb);
6635 zone->inactive_ratio = ratio;
6638 static void __meminit setup_per_zone_inactive_ratio(void)
6643 calculate_zone_inactive_ratio(zone);
6647 * Initialise min_free_kbytes.
6649 * For small machines we want it small (128k min). For large machines
6650 * we want it large (64MB max). But it is not linear, because network
6651 * bandwidth does not increase linearly with machine size. We use
6653 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6654 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6670 int __meminit init_per_zone_wmark_min(void)
6672 unsigned long lowmem_kbytes;
6673 int new_min_free_kbytes;
6675 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6676 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6678 if (new_min_free_kbytes > user_min_free_kbytes) {
6679 min_free_kbytes = new_min_free_kbytes;
6680 if (min_free_kbytes < 128)
6681 min_free_kbytes = 128;
6682 if (min_free_kbytes > 65536)
6683 min_free_kbytes = 65536;
6685 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6686 new_min_free_kbytes, user_min_free_kbytes);
6688 setup_per_zone_wmarks();
6689 refresh_zone_stat_thresholds();
6690 setup_per_zone_lowmem_reserve();
6691 setup_per_zone_inactive_ratio();
6694 core_initcall(init_per_zone_wmark_min)
6697 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6698 * that we can call two helper functions whenever min_free_kbytes
6701 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6702 void __user *buffer, size_t *length, loff_t *ppos)
6706 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6711 user_min_free_kbytes = min_free_kbytes;
6712 setup_per_zone_wmarks();
6717 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6718 void __user *buffer, size_t *length, loff_t *ppos)
6722 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6727 setup_per_zone_wmarks();
6733 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6734 void __user *buffer, size_t *length, loff_t *ppos)
6739 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6744 zone->min_unmapped_pages = (zone->managed_pages *
6745 sysctl_min_unmapped_ratio) / 100;
6749 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6750 void __user *buffer, size_t *length, loff_t *ppos)
6755 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6760 zone->min_slab_pages = (zone->managed_pages *
6761 sysctl_min_slab_ratio) / 100;
6767 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6768 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6769 * whenever sysctl_lowmem_reserve_ratio changes.
6771 * The reserve ratio obviously has absolutely no relation with the
6772 * minimum watermarks. The lowmem reserve ratio can only make sense
6773 * if in function of the boot time zone sizes.
6775 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6776 void __user *buffer, size_t *length, loff_t *ppos)
6778 proc_dointvec_minmax(table, write, buffer, length, ppos);
6779 setup_per_zone_lowmem_reserve();
6784 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6785 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6786 * pagelist can have before it gets flushed back to buddy allocator.
6788 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6789 void __user *buffer, size_t *length, loff_t *ppos)
6792 int old_percpu_pagelist_fraction;
6795 mutex_lock(&pcp_batch_high_lock);
6796 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6798 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6799 if (!write || ret < 0)
6802 /* Sanity checking to avoid pcp imbalance */
6803 if (percpu_pagelist_fraction &&
6804 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6805 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6811 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6814 for_each_populated_zone(zone) {
6817 for_each_possible_cpu(cpu)
6818 pageset_set_high_and_batch(zone,
6819 per_cpu_ptr(zone->pageset, cpu));
6822 mutex_unlock(&pcp_batch_high_lock);
6827 int hashdist = HASHDIST_DEFAULT;
6829 static int __init set_hashdist(char *str)
6833 hashdist = simple_strtoul(str, &str, 0);
6836 __setup("hashdist=", set_hashdist);
6840 * allocate a large system hash table from bootmem
6841 * - it is assumed that the hash table must contain an exact power-of-2
6842 * quantity of entries
6843 * - limit is the number of hash buckets, not the total allocation size
6845 void *__init alloc_large_system_hash(const char *tablename,
6846 unsigned long bucketsize,
6847 unsigned long numentries,
6850 unsigned int *_hash_shift,
6851 unsigned int *_hash_mask,
6852 unsigned long low_limit,
6853 unsigned long high_limit)
6855 unsigned long long max = high_limit;
6856 unsigned long log2qty, size;
6859 /* allow the kernel cmdline to have a say */
6861 /* round applicable memory size up to nearest megabyte */
6862 numentries = nr_kernel_pages;
6864 /* It isn't necessary when PAGE_SIZE >= 1MB */
6865 if (PAGE_SHIFT < 20)
6866 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6868 /* limit to 1 bucket per 2^scale bytes of low memory */
6869 if (scale > PAGE_SHIFT)
6870 numentries >>= (scale - PAGE_SHIFT);
6872 numentries <<= (PAGE_SHIFT - scale);
6874 /* Make sure we've got at least a 0-order allocation.. */
6875 if (unlikely(flags & HASH_SMALL)) {
6876 /* Makes no sense without HASH_EARLY */
6877 WARN_ON(!(flags & HASH_EARLY));
6878 if (!(numentries >> *_hash_shift)) {
6879 numentries = 1UL << *_hash_shift;
6880 BUG_ON(!numentries);
6882 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6883 numentries = PAGE_SIZE / bucketsize;
6885 numentries = roundup_pow_of_two(numentries);
6887 /* limit allocation size to 1/16 total memory by default */
6889 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6890 do_div(max, bucketsize);
6892 max = min(max, 0x80000000ULL);
6894 if (numentries < low_limit)
6895 numentries = low_limit;
6896 if (numentries > max)
6899 log2qty = ilog2(numentries);
6902 size = bucketsize << log2qty;
6903 if (flags & HASH_EARLY)
6904 table = memblock_virt_alloc_nopanic(size, 0);
6906 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6909 * If bucketsize is not a power-of-two, we may free
6910 * some pages at the end of hash table which
6911 * alloc_pages_exact() automatically does
6913 if (get_order(size) < MAX_ORDER) {
6914 table = alloc_pages_exact(size, GFP_ATOMIC);
6915 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6918 } while (!table && size > PAGE_SIZE && --log2qty);
6921 panic("Failed to allocate %s hash table\n", tablename);
6923 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6924 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
6927 *_hash_shift = log2qty;
6929 *_hash_mask = (1 << log2qty) - 1;
6935 * This function checks whether pageblock includes unmovable pages or not.
6936 * If @count is not zero, it is okay to include less @count unmovable pages
6938 * PageLRU check without isolation or lru_lock could race so that
6939 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6940 * expect this function should be exact.
6942 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6943 bool skip_hwpoisoned_pages)
6945 unsigned long pfn, iter, found;
6949 * For avoiding noise data, lru_add_drain_all() should be called
6950 * If ZONE_MOVABLE, the zone never contains unmovable pages
6952 if (zone_idx(zone) == ZONE_MOVABLE)
6954 mt = get_pageblock_migratetype(page);
6955 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6958 pfn = page_to_pfn(page);
6959 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6960 unsigned long check = pfn + iter;
6962 if (!pfn_valid_within(check))
6965 page = pfn_to_page(check);
6968 * Hugepages are not in LRU lists, but they're movable.
6969 * We need not scan over tail pages bacause we don't
6970 * handle each tail page individually in migration.
6972 if (PageHuge(page)) {
6973 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6978 * We can't use page_count without pin a page
6979 * because another CPU can free compound page.
6980 * This check already skips compound tails of THP
6981 * because their page->_refcount is zero at all time.
6983 if (!page_ref_count(page)) {
6984 if (PageBuddy(page))
6985 iter += (1 << page_order(page)) - 1;
6990 * The HWPoisoned page may be not in buddy system, and
6991 * page_count() is not 0.
6993 if (skip_hwpoisoned_pages && PageHWPoison(page))
6999 * If there are RECLAIMABLE pages, we need to check
7000 * it. But now, memory offline itself doesn't call
7001 * shrink_node_slabs() and it still to be fixed.
7004 * If the page is not RAM, page_count()should be 0.
7005 * we don't need more check. This is an _used_ not-movable page.
7007 * The problematic thing here is PG_reserved pages. PG_reserved
7008 * is set to both of a memory hole page and a _used_ kernel
7017 bool is_pageblock_removable_nolock(struct page *page)
7023 * We have to be careful here because we are iterating over memory
7024 * sections which are not zone aware so we might end up outside of
7025 * the zone but still within the section.
7026 * We have to take care about the node as well. If the node is offline
7027 * its NODE_DATA will be NULL - see page_zone.
7029 if (!node_online(page_to_nid(page)))
7032 zone = page_zone(page);
7033 pfn = page_to_pfn(page);
7034 if (!zone_spans_pfn(zone, pfn))
7037 return !has_unmovable_pages(zone, page, 0, true);
7040 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7042 static unsigned long pfn_max_align_down(unsigned long pfn)
7044 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7045 pageblock_nr_pages) - 1);
7048 static unsigned long pfn_max_align_up(unsigned long pfn)
7050 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7051 pageblock_nr_pages));
7054 /* [start, end) must belong to a single zone. */
7055 static int __alloc_contig_migrate_range(struct compact_control *cc,
7056 unsigned long start, unsigned long end)
7058 /* This function is based on compact_zone() from compaction.c. */
7059 unsigned long nr_reclaimed;
7060 unsigned long pfn = start;
7061 unsigned int tries = 0;
7066 while (pfn < end || !list_empty(&cc->migratepages)) {
7067 if (fatal_signal_pending(current)) {
7072 if (list_empty(&cc->migratepages)) {
7073 cc->nr_migratepages = 0;
7074 pfn = isolate_migratepages_range(cc, pfn, end);
7080 } else if (++tries == 5) {
7081 ret = ret < 0 ? ret : -EBUSY;
7085 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7087 cc->nr_migratepages -= nr_reclaimed;
7089 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7090 NULL, 0, cc->mode, MR_CMA);
7093 putback_movable_pages(&cc->migratepages);
7100 * alloc_contig_range() -- tries to allocate given range of pages
7101 * @start: start PFN to allocate
7102 * @end: one-past-the-last PFN to allocate
7103 * @migratetype: migratetype of the underlaying pageblocks (either
7104 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7105 * in range must have the same migratetype and it must
7106 * be either of the two.
7108 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7109 * aligned, however it's the caller's responsibility to guarantee that
7110 * we are the only thread that changes migrate type of pageblocks the
7113 * The PFN range must belong to a single zone.
7115 * Returns zero on success or negative error code. On success all
7116 * pages which PFN is in [start, end) are allocated for the caller and
7117 * need to be freed with free_contig_range().
7119 int alloc_contig_range(unsigned long start, unsigned long end,
7120 unsigned migratetype)
7122 unsigned long outer_start, outer_end;
7126 struct compact_control cc = {
7127 .nr_migratepages = 0,
7129 .zone = page_zone(pfn_to_page(start)),
7130 .mode = MIGRATE_SYNC,
7131 .ignore_skip_hint = true,
7133 INIT_LIST_HEAD(&cc.migratepages);
7136 * What we do here is we mark all pageblocks in range as
7137 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7138 * have different sizes, and due to the way page allocator
7139 * work, we align the range to biggest of the two pages so
7140 * that page allocator won't try to merge buddies from
7141 * different pageblocks and change MIGRATE_ISOLATE to some
7142 * other migration type.
7144 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7145 * migrate the pages from an unaligned range (ie. pages that
7146 * we are interested in). This will put all the pages in
7147 * range back to page allocator as MIGRATE_ISOLATE.
7149 * When this is done, we take the pages in range from page
7150 * allocator removing them from the buddy system. This way
7151 * page allocator will never consider using them.
7153 * This lets us mark the pageblocks back as
7154 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7155 * aligned range but not in the unaligned, original range are
7156 * put back to page allocator so that buddy can use them.
7159 ret = start_isolate_page_range(pfn_max_align_down(start),
7160 pfn_max_align_up(end), migratetype,
7166 * In case of -EBUSY, we'd like to know which page causes problem.
7167 * So, just fall through. We will check it in test_pages_isolated().
7169 ret = __alloc_contig_migrate_range(&cc, start, end);
7170 if (ret && ret != -EBUSY)
7174 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7175 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7176 * more, all pages in [start, end) are free in page allocator.
7177 * What we are going to do is to allocate all pages from
7178 * [start, end) (that is remove them from page allocator).
7180 * The only problem is that pages at the beginning and at the
7181 * end of interesting range may be not aligned with pages that
7182 * page allocator holds, ie. they can be part of higher order
7183 * pages. Because of this, we reserve the bigger range and
7184 * once this is done free the pages we are not interested in.
7186 * We don't have to hold zone->lock here because the pages are
7187 * isolated thus they won't get removed from buddy.
7190 lru_add_drain_all();
7191 drain_all_pages(cc.zone);
7194 outer_start = start;
7195 while (!PageBuddy(pfn_to_page(outer_start))) {
7196 if (++order >= MAX_ORDER) {
7197 outer_start = start;
7200 outer_start &= ~0UL << order;
7203 if (outer_start != start) {
7204 order = page_order(pfn_to_page(outer_start));
7207 * outer_start page could be small order buddy page and
7208 * it doesn't include start page. Adjust outer_start
7209 * in this case to report failed page properly
7210 * on tracepoint in test_pages_isolated()
7212 if (outer_start + (1UL << order) <= start)
7213 outer_start = start;
7216 /* Make sure the range is really isolated. */
7217 if (test_pages_isolated(outer_start, end, false)) {
7218 pr_info("%s: [%lx, %lx) PFNs busy\n",
7219 __func__, outer_start, end);
7224 /* Grab isolated pages from freelists. */
7225 outer_end = isolate_freepages_range(&cc, outer_start, end);
7231 /* Free head and tail (if any) */
7232 if (start != outer_start)
7233 free_contig_range(outer_start, start - outer_start);
7234 if (end != outer_end)
7235 free_contig_range(end, outer_end - end);
7238 undo_isolate_page_range(pfn_max_align_down(start),
7239 pfn_max_align_up(end), migratetype);
7243 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7245 unsigned int count = 0;
7247 for (; nr_pages--; pfn++) {
7248 struct page *page = pfn_to_page(pfn);
7250 count += page_count(page) != 1;
7253 WARN(count != 0, "%d pages are still in use!\n", count);
7257 #ifdef CONFIG_MEMORY_HOTPLUG
7259 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7260 * page high values need to be recalulated.
7262 void __meminit zone_pcp_update(struct zone *zone)
7265 mutex_lock(&pcp_batch_high_lock);
7266 for_each_possible_cpu(cpu)
7267 pageset_set_high_and_batch(zone,
7268 per_cpu_ptr(zone->pageset, cpu));
7269 mutex_unlock(&pcp_batch_high_lock);
7273 void zone_pcp_reset(struct zone *zone)
7275 unsigned long flags;
7277 struct per_cpu_pageset *pset;
7279 /* avoid races with drain_pages() */
7280 local_irq_save(flags);
7281 if (zone->pageset != &boot_pageset) {
7282 for_each_online_cpu(cpu) {
7283 pset = per_cpu_ptr(zone->pageset, cpu);
7284 drain_zonestat(zone, pset);
7286 free_percpu(zone->pageset);
7287 zone->pageset = &boot_pageset;
7289 local_irq_restore(flags);
7292 #ifdef CONFIG_MEMORY_HOTREMOVE
7294 * All pages in the range must be in a single zone and isolated
7295 * before calling this.
7298 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7302 unsigned int order, i;
7304 unsigned long flags;
7305 /* find the first valid pfn */
7306 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7311 zone = page_zone(pfn_to_page(pfn));
7312 spin_lock_irqsave(&zone->lock, flags);
7314 while (pfn < end_pfn) {
7315 if (!pfn_valid(pfn)) {
7319 page = pfn_to_page(pfn);
7321 * The HWPoisoned page may be not in buddy system, and
7322 * page_count() is not 0.
7324 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7326 SetPageReserved(page);
7330 BUG_ON(page_count(page));
7331 BUG_ON(!PageBuddy(page));
7332 order = page_order(page);
7333 #ifdef CONFIG_DEBUG_VM
7334 pr_info("remove from free list %lx %d %lx\n",
7335 pfn, 1 << order, end_pfn);
7337 list_del(&page->lru);
7338 rmv_page_order(page);
7339 zone->free_area[order].nr_free--;
7340 for (i = 0; i < (1 << order); i++)
7341 SetPageReserved((page+i));
7342 pfn += (1 << order);
7344 spin_unlock_irqrestore(&zone->lock, flags);
7348 bool is_free_buddy_page(struct page *page)
7350 struct zone *zone = page_zone(page);
7351 unsigned long pfn = page_to_pfn(page);
7352 unsigned long flags;
7355 spin_lock_irqsave(&zone->lock, flags);
7356 for (order = 0; order < MAX_ORDER; order++) {
7357 struct page *page_head = page - (pfn & ((1 << order) - 1));
7359 if (PageBuddy(page_head) && page_order(page_head) >= order)
7362 spin_unlock_irqrestore(&zone->lock, flags);
7364 return order < MAX_ORDER;