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);
944 static int free_tail_pages_check(struct page *head_page, struct page *page)
949 * We rely page->lru.next never has bit 0 set, unless the page
950 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
952 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
954 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
958 switch (page - head_page) {
960 /* the first tail page: ->mapping is compound_mapcount() */
961 if (unlikely(compound_mapcount(page))) {
962 bad_page(page, "nonzero compound_mapcount", 0);
968 * the second tail page: ->mapping is
969 * page_deferred_list().next -- ignore value.
973 if (page->mapping != TAIL_MAPPING) {
974 bad_page(page, "corrupted mapping in tail page", 0);
979 if (unlikely(!PageTail(page))) {
980 bad_page(page, "PageTail not set", 0);
983 if (unlikely(compound_head(page) != head_page)) {
984 bad_page(page, "compound_head not consistent", 0);
989 page->mapping = NULL;
990 clear_compound_head(page);
994 static __always_inline bool free_pages_prepare(struct page *page,
995 unsigned int order, bool check_free)
999 VM_BUG_ON_PAGE(PageTail(page), page);
1001 trace_mm_page_free(page, order);
1002 kmemcheck_free_shadow(page, order);
1003 kasan_free_pages(page, order);
1006 * Check tail pages before head page information is cleared to
1007 * avoid checking PageCompound for order-0 pages.
1009 if (unlikely(order)) {
1010 bool compound = PageCompound(page);
1013 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1015 for (i = 1; i < (1 << order); i++) {
1017 bad += free_tail_pages_check(page, page + i);
1018 if (unlikely(free_pages_check(page + i))) {
1022 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1025 if (PageAnonHead(page))
1026 page->mapping = NULL;
1028 bad += free_pages_check(page);
1032 page_cpupid_reset_last(page);
1033 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1034 reset_page_owner(page, order);
1036 if (!PageHighMem(page)) {
1037 debug_check_no_locks_freed(page_address(page),
1038 PAGE_SIZE << order);
1039 debug_check_no_obj_freed(page_address(page),
1040 PAGE_SIZE << order);
1042 arch_free_page(page, order);
1043 kernel_poison_pages(page, 1 << order, 0);
1044 kernel_map_pages(page, 1 << order, 0);
1049 #ifdef CONFIG_DEBUG_VM
1050 static inline bool free_pcp_prepare(struct page *page)
1052 return free_pages_prepare(page, 0, true);
1055 static inline bool bulkfree_pcp_prepare(struct page *page)
1060 static bool free_pcp_prepare(struct page *page)
1062 return free_pages_prepare(page, 0, false);
1065 static bool bulkfree_pcp_prepare(struct page *page)
1067 return free_pages_check(page);
1069 #endif /* CONFIG_DEBUG_VM */
1072 * Frees a number of pages from the PCP lists
1073 * Assumes all pages on list are in same zone, and of same order.
1074 * count is the number of pages to free.
1076 * If the zone was previously in an "all pages pinned" state then look to
1077 * see if this freeing clears that state.
1079 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1080 * pinned" detection logic.
1082 static void free_pcppages_bulk(struct zone *zone, int count,
1083 struct per_cpu_pages *pcp)
1085 int migratetype = 0;
1087 unsigned long nr_scanned;
1088 bool isolated_pageblocks;
1090 spin_lock(&zone->lock);
1091 isolated_pageblocks = has_isolate_pageblock(zone);
1092 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1094 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1098 struct list_head *list;
1101 * Remove pages from lists in a round-robin fashion. A
1102 * batch_free count is maintained that is incremented when an
1103 * empty list is encountered. This is so more pages are freed
1104 * off fuller lists instead of spinning excessively around empty
1109 if (++migratetype == MIGRATE_PCPTYPES)
1111 list = &pcp->lists[migratetype];
1112 } while (list_empty(list));
1114 /* This is the only non-empty list. Free them all. */
1115 if (batch_free == MIGRATE_PCPTYPES)
1119 int mt; /* migratetype of the to-be-freed page */
1121 page = list_last_entry(list, struct page, lru);
1122 /* must delete as __free_one_page list manipulates */
1123 list_del(&page->lru);
1125 mt = get_pcppage_migratetype(page);
1126 /* MIGRATE_ISOLATE page should not go to pcplists */
1127 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1128 /* Pageblock could have been isolated meanwhile */
1129 if (unlikely(isolated_pageblocks))
1130 mt = get_pageblock_migratetype(page);
1132 if (bulkfree_pcp_prepare(page))
1135 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1136 trace_mm_page_pcpu_drain(page, 0, mt);
1137 } while (--count && --batch_free && !list_empty(list));
1139 spin_unlock(&zone->lock);
1142 static void free_one_page(struct zone *zone,
1143 struct page *page, unsigned long pfn,
1147 unsigned long nr_scanned;
1148 spin_lock(&zone->lock);
1149 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1151 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1153 if (unlikely(has_isolate_pageblock(zone) ||
1154 is_migrate_isolate(migratetype))) {
1155 migratetype = get_pfnblock_migratetype(page, pfn);
1157 __free_one_page(page, pfn, zone, order, migratetype);
1158 spin_unlock(&zone->lock);
1161 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1162 unsigned long zone, int nid)
1164 set_page_links(page, zone, nid, pfn);
1165 init_page_count(page);
1166 page_mapcount_reset(page);
1167 page_cpupid_reset_last(page);
1169 INIT_LIST_HEAD(&page->lru);
1170 #ifdef WANT_PAGE_VIRTUAL
1171 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1172 if (!is_highmem_idx(zone))
1173 set_page_address(page, __va(pfn << PAGE_SHIFT));
1177 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
1180 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
1183 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1184 static void init_reserved_page(unsigned long pfn)
1189 if (!early_page_uninitialised(pfn))
1192 nid = early_pfn_to_nid(pfn);
1193 pgdat = NODE_DATA(nid);
1195 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1196 struct zone *zone = &pgdat->node_zones[zid];
1198 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1201 __init_single_pfn(pfn, zid, nid);
1204 static inline void init_reserved_page(unsigned long pfn)
1207 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1210 * Initialised pages do not have PageReserved set. This function is
1211 * called for each range allocated by the bootmem allocator and
1212 * marks the pages PageReserved. The remaining valid pages are later
1213 * sent to the buddy page allocator.
1215 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
1217 unsigned long start_pfn = PFN_DOWN(start);
1218 unsigned long end_pfn = PFN_UP(end);
1220 for (; start_pfn < end_pfn; start_pfn++) {
1221 if (pfn_valid(start_pfn)) {
1222 struct page *page = pfn_to_page(start_pfn);
1224 init_reserved_page(start_pfn);
1226 /* Avoid false-positive PageTail() */
1227 INIT_LIST_HEAD(&page->lru);
1229 SetPageReserved(page);
1234 static void __free_pages_ok(struct page *page, unsigned int order)
1236 unsigned long flags;
1238 unsigned long pfn = page_to_pfn(page);
1240 if (!free_pages_prepare(page, order, true))
1243 migratetype = get_pfnblock_migratetype(page, pfn);
1244 local_irq_save(flags);
1245 __count_vm_events(PGFREE, 1 << order);
1246 free_one_page(page_zone(page), page, pfn, order, migratetype);
1247 local_irq_restore(flags);
1250 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1252 unsigned int nr_pages = 1 << order;
1253 struct page *p = page;
1257 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1259 __ClearPageReserved(p);
1260 set_page_count(p, 0);
1262 __ClearPageReserved(p);
1263 set_page_count(p, 0);
1265 page_zone(page)->managed_pages += nr_pages;
1266 set_page_refcounted(page);
1267 __free_pages(page, order);
1270 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1271 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1273 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1275 int __meminit early_pfn_to_nid(unsigned long pfn)
1277 static DEFINE_SPINLOCK(early_pfn_lock);
1280 spin_lock(&early_pfn_lock);
1281 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1284 spin_unlock(&early_pfn_lock);
1290 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1291 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1292 struct mminit_pfnnid_cache *state)
1296 nid = __early_pfn_to_nid(pfn, state);
1297 if (nid >= 0 && nid != node)
1302 /* Only safe to use early in boot when initialisation is single-threaded */
1303 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1305 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1310 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1314 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1315 struct mminit_pfnnid_cache *state)
1322 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1325 if (early_page_uninitialised(pfn))
1327 return __free_pages_boot_core(page, order);
1331 * Check that the whole (or subset of) a pageblock given by the interval of
1332 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1333 * with the migration of free compaction scanner. The scanners then need to
1334 * use only pfn_valid_within() check for arches that allow holes within
1337 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1339 * It's possible on some configurations to have a setup like node0 node1 node0
1340 * i.e. it's possible that all pages within a zones range of pages do not
1341 * belong to a single zone. We assume that a border between node0 and node1
1342 * can occur within a single pageblock, but not a node0 node1 node0
1343 * interleaving within a single pageblock. It is therefore sufficient to check
1344 * the first and last page of a pageblock and avoid checking each individual
1345 * page in a pageblock.
1347 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1348 unsigned long end_pfn, struct zone *zone)
1350 struct page *start_page;
1351 struct page *end_page;
1353 /* end_pfn is one past the range we are checking */
1356 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1359 start_page = pfn_to_page(start_pfn);
1361 if (page_zone(start_page) != zone)
1364 end_page = pfn_to_page(end_pfn);
1366 /* This gives a shorter code than deriving page_zone(end_page) */
1367 if (page_zone_id(start_page) != page_zone_id(end_page))
1373 void set_zone_contiguous(struct zone *zone)
1375 unsigned long block_start_pfn = zone->zone_start_pfn;
1376 unsigned long block_end_pfn;
1378 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1379 for (; block_start_pfn < zone_end_pfn(zone);
1380 block_start_pfn = block_end_pfn,
1381 block_end_pfn += pageblock_nr_pages) {
1383 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1385 if (!__pageblock_pfn_to_page(block_start_pfn,
1386 block_end_pfn, zone))
1390 /* We confirm that there is no hole */
1391 zone->contiguous = true;
1394 void clear_zone_contiguous(struct zone *zone)
1396 zone->contiguous = false;
1399 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1400 static void __init deferred_free_range(struct page *page,
1401 unsigned long pfn, int nr_pages)
1408 /* Free a large naturally-aligned chunk if possible */
1409 if (nr_pages == MAX_ORDER_NR_PAGES &&
1410 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1411 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1412 __free_pages_boot_core(page, MAX_ORDER-1);
1416 for (i = 0; i < nr_pages; i++, page++)
1417 __free_pages_boot_core(page, 0);
1420 /* Completion tracking for deferred_init_memmap() threads */
1421 static atomic_t pgdat_init_n_undone __initdata;
1422 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1424 static inline void __init pgdat_init_report_one_done(void)
1426 if (atomic_dec_and_test(&pgdat_init_n_undone))
1427 complete(&pgdat_init_all_done_comp);
1430 /* Initialise remaining memory on a node */
1431 static int __init deferred_init_memmap(void *data)
1433 pg_data_t *pgdat = data;
1434 int nid = pgdat->node_id;
1435 struct mminit_pfnnid_cache nid_init_state = { };
1436 unsigned long start = jiffies;
1437 unsigned long nr_pages = 0;
1438 unsigned long walk_start, walk_end;
1441 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1442 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1444 if (first_init_pfn == ULONG_MAX) {
1445 pgdat_init_report_one_done();
1449 /* Bind memory initialisation thread to a local node if possible */
1450 if (!cpumask_empty(cpumask))
1451 set_cpus_allowed_ptr(current, cpumask);
1453 /* Sanity check boundaries */
1454 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1455 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1456 pgdat->first_deferred_pfn = ULONG_MAX;
1458 /* Only the highest zone is deferred so find it */
1459 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1460 zone = pgdat->node_zones + zid;
1461 if (first_init_pfn < zone_end_pfn(zone))
1465 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1466 unsigned long pfn, end_pfn;
1467 struct page *page = NULL;
1468 struct page *free_base_page = NULL;
1469 unsigned long free_base_pfn = 0;
1472 end_pfn = min(walk_end, zone_end_pfn(zone));
1473 pfn = first_init_pfn;
1474 if (pfn < walk_start)
1476 if (pfn < zone->zone_start_pfn)
1477 pfn = zone->zone_start_pfn;
1479 for (; pfn < end_pfn; pfn++) {
1480 if (!pfn_valid_within(pfn))
1484 * Ensure pfn_valid is checked every
1485 * MAX_ORDER_NR_PAGES for memory holes
1487 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1488 if (!pfn_valid(pfn)) {
1494 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1499 /* Minimise pfn page lookups and scheduler checks */
1500 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1503 nr_pages += nr_to_free;
1504 deferred_free_range(free_base_page,
1505 free_base_pfn, nr_to_free);
1506 free_base_page = NULL;
1507 free_base_pfn = nr_to_free = 0;
1509 page = pfn_to_page(pfn);
1514 VM_BUG_ON(page_zone(page) != zone);
1518 __init_single_page(page, pfn, zid, nid);
1519 if (!free_base_page) {
1520 free_base_page = page;
1521 free_base_pfn = pfn;
1526 /* Where possible, batch up pages for a single free */
1529 /* Free the current block of pages to allocator */
1530 nr_pages += nr_to_free;
1531 deferred_free_range(free_base_page, free_base_pfn,
1533 free_base_page = NULL;
1534 free_base_pfn = nr_to_free = 0;
1537 first_init_pfn = max(end_pfn, first_init_pfn);
1540 /* Sanity check that the next zone really is unpopulated */
1541 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1543 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1544 jiffies_to_msecs(jiffies - start));
1546 pgdat_init_report_one_done();
1549 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1551 void __init page_alloc_init_late(void)
1555 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1558 /* There will be num_node_state(N_MEMORY) threads */
1559 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1560 for_each_node_state(nid, N_MEMORY) {
1561 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1564 /* Block until all are initialised */
1565 wait_for_completion(&pgdat_init_all_done_comp);
1567 /* Reinit limits that are based on free pages after the kernel is up */
1568 files_maxfiles_init();
1571 for_each_populated_zone(zone)
1572 set_zone_contiguous(zone);
1576 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1577 void __init init_cma_reserved_pageblock(struct page *page)
1579 unsigned i = pageblock_nr_pages;
1580 struct page *p = page;
1583 __ClearPageReserved(p);
1584 set_page_count(p, 0);
1587 set_pageblock_migratetype(page, MIGRATE_CMA);
1589 if (pageblock_order >= MAX_ORDER) {
1590 i = pageblock_nr_pages;
1593 set_page_refcounted(p);
1594 __free_pages(p, MAX_ORDER - 1);
1595 p += MAX_ORDER_NR_PAGES;
1596 } while (i -= MAX_ORDER_NR_PAGES);
1598 set_page_refcounted(page);
1599 __free_pages(page, pageblock_order);
1602 adjust_managed_page_count(page, pageblock_nr_pages);
1607 * The order of subdivision here is critical for the IO subsystem.
1608 * Please do not alter this order without good reasons and regression
1609 * testing. Specifically, as large blocks of memory are subdivided,
1610 * the order in which smaller blocks are delivered depends on the order
1611 * they're subdivided in this function. This is the primary factor
1612 * influencing the order in which pages are delivered to the IO
1613 * subsystem according to empirical testing, and this is also justified
1614 * by considering the behavior of a buddy system containing a single
1615 * large block of memory acted on by a series of small allocations.
1616 * This behavior is a critical factor in sglist merging's success.
1620 static inline void expand(struct zone *zone, struct page *page,
1621 int low, int high, struct free_area *area,
1624 unsigned long size = 1 << high;
1626 while (high > low) {
1630 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1632 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1633 debug_guardpage_enabled() &&
1634 high < debug_guardpage_minorder()) {
1636 * Mark as guard pages (or page), that will allow to
1637 * merge back to allocator when buddy will be freed.
1638 * Corresponding page table entries will not be touched,
1639 * pages will stay not present in virtual address space
1641 set_page_guard(zone, &page[size], high, migratetype);
1644 list_add(&page[size].lru, &area->free_list[migratetype]);
1646 set_page_order(&page[size], high);
1650 static void check_new_page_bad(struct page *page)
1652 const char *bad_reason = NULL;
1653 unsigned long bad_flags = 0;
1655 if (unlikely(atomic_read(&page->_mapcount) != -1))
1656 bad_reason = "nonzero mapcount";
1657 if (unlikely(page->mapping != NULL))
1658 bad_reason = "non-NULL mapping";
1659 if (unlikely(page_ref_count(page) != 0))
1660 bad_reason = "nonzero _count";
1661 if (unlikely(page->flags & __PG_HWPOISON)) {
1662 bad_reason = "HWPoisoned (hardware-corrupted)";
1663 bad_flags = __PG_HWPOISON;
1665 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1666 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1667 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1670 if (unlikely(page->mem_cgroup))
1671 bad_reason = "page still charged to cgroup";
1673 bad_page(page, bad_reason, bad_flags);
1677 * This page is about to be returned from the page allocator
1679 static inline int check_new_page(struct page *page)
1681 if (likely(page_expected_state(page,
1682 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
1685 check_new_page_bad(page);
1689 static inline bool free_pages_prezeroed(bool poisoned)
1691 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1692 page_poisoning_enabled() && poisoned;
1695 #ifdef CONFIG_DEBUG_VM
1696 static bool check_pcp_refill(struct page *page)
1701 static bool check_new_pcp(struct page *page)
1703 return check_new_page(page);
1706 static bool check_pcp_refill(struct page *page)
1708 return check_new_page(page);
1710 static bool check_new_pcp(struct page *page)
1714 #endif /* CONFIG_DEBUG_VM */
1716 static bool check_new_pages(struct page *page, unsigned int order)
1719 for (i = 0; i < (1 << order); i++) {
1720 struct page *p = page + i;
1722 if (unlikely(check_new_page(p)))
1729 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1730 unsigned int alloc_flags)
1733 bool poisoned = true;
1735 for (i = 0; i < (1 << order); i++) {
1736 struct page *p = page + i;
1738 poisoned &= page_is_poisoned(p);
1741 set_page_private(page, 0);
1742 set_page_refcounted(page);
1744 arch_alloc_page(page, order);
1745 kernel_map_pages(page, 1 << order, 1);
1746 kernel_poison_pages(page, 1 << order, 1);
1747 kasan_alloc_pages(page, order);
1749 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1750 for (i = 0; i < (1 << order); i++)
1751 clear_highpage(page + i);
1753 if (order && (gfp_flags & __GFP_COMP))
1754 prep_compound_page(page, order);
1756 set_page_owner(page, order, gfp_flags);
1759 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1760 * allocate the page. The expectation is that the caller is taking
1761 * steps that will free more memory. The caller should avoid the page
1762 * being used for !PFMEMALLOC purposes.
1764 if (alloc_flags & ALLOC_NO_WATERMARKS)
1765 set_page_pfmemalloc(page);
1767 clear_page_pfmemalloc(page);
1771 * Go through the free lists for the given migratetype and remove
1772 * the smallest available page from the freelists
1775 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1778 unsigned int current_order;
1779 struct free_area *area;
1782 /* Find a page of the appropriate size in the preferred list */
1783 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1784 area = &(zone->free_area[current_order]);
1785 page = list_first_entry_or_null(&area->free_list[migratetype],
1789 list_del(&page->lru);
1790 rmv_page_order(page);
1792 expand(zone, page, order, current_order, area, migratetype);
1793 set_pcppage_migratetype(page, migratetype);
1802 * This array describes the order lists are fallen back to when
1803 * the free lists for the desirable migrate type are depleted
1805 static int fallbacks[MIGRATE_TYPES][4] = {
1806 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1807 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1808 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1810 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1812 #ifdef CONFIG_MEMORY_ISOLATION
1813 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1818 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1821 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1824 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1825 unsigned int order) { return NULL; }
1829 * Move the free pages in a range to the free lists of the requested type.
1830 * Note that start_page and end_pages are not aligned on a pageblock
1831 * boundary. If alignment is required, use move_freepages_block()
1833 int move_freepages(struct zone *zone,
1834 struct page *start_page, struct page *end_page,
1839 int pages_moved = 0;
1841 #ifndef CONFIG_HOLES_IN_ZONE
1843 * page_zone is not safe to call in this context when
1844 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1845 * anyway as we check zone boundaries in move_freepages_block().
1846 * Remove at a later date when no bug reports exist related to
1847 * grouping pages by mobility
1849 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1852 for (page = start_page; page <= end_page;) {
1853 /* Make sure we are not inadvertently changing nodes */
1854 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1856 if (!pfn_valid_within(page_to_pfn(page))) {
1861 if (!PageBuddy(page)) {
1866 order = page_order(page);
1867 list_move(&page->lru,
1868 &zone->free_area[order].free_list[migratetype]);
1870 pages_moved += 1 << order;
1876 int move_freepages_block(struct zone *zone, struct page *page,
1879 unsigned long start_pfn, end_pfn;
1880 struct page *start_page, *end_page;
1882 start_pfn = page_to_pfn(page);
1883 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1884 start_page = pfn_to_page(start_pfn);
1885 end_page = start_page + pageblock_nr_pages - 1;
1886 end_pfn = start_pfn + pageblock_nr_pages - 1;
1888 /* Do not cross zone boundaries */
1889 if (!zone_spans_pfn(zone, start_pfn))
1891 if (!zone_spans_pfn(zone, end_pfn))
1894 return move_freepages(zone, start_page, end_page, migratetype);
1897 static void change_pageblock_range(struct page *pageblock_page,
1898 int start_order, int migratetype)
1900 int nr_pageblocks = 1 << (start_order - pageblock_order);
1902 while (nr_pageblocks--) {
1903 set_pageblock_migratetype(pageblock_page, migratetype);
1904 pageblock_page += pageblock_nr_pages;
1909 * When we are falling back to another migratetype during allocation, try to
1910 * steal extra free pages from the same pageblocks to satisfy further
1911 * allocations, instead of polluting multiple pageblocks.
1913 * If we are stealing a relatively large buddy page, it is likely there will
1914 * be more free pages in the pageblock, so try to steal them all. For
1915 * reclaimable and unmovable allocations, we steal regardless of page size,
1916 * as fragmentation caused by those allocations polluting movable pageblocks
1917 * is worse than movable allocations stealing from unmovable and reclaimable
1920 static bool can_steal_fallback(unsigned int order, int start_mt)
1923 * Leaving this order check is intended, although there is
1924 * relaxed order check in next check. The reason is that
1925 * we can actually steal whole pageblock if this condition met,
1926 * but, below check doesn't guarantee it and that is just heuristic
1927 * so could be changed anytime.
1929 if (order >= pageblock_order)
1932 if (order >= pageblock_order / 2 ||
1933 start_mt == MIGRATE_RECLAIMABLE ||
1934 start_mt == MIGRATE_UNMOVABLE ||
1935 page_group_by_mobility_disabled)
1942 * This function implements actual steal behaviour. If order is large enough,
1943 * we can steal whole pageblock. If not, we first move freepages in this
1944 * pageblock and check whether half of pages are moved or not. If half of
1945 * pages are moved, we can change migratetype of pageblock and permanently
1946 * use it's pages as requested migratetype in the future.
1948 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1951 unsigned int current_order = page_order(page);
1954 /* Take ownership for orders >= pageblock_order */
1955 if (current_order >= pageblock_order) {
1956 change_pageblock_range(page, current_order, start_type);
1960 pages = move_freepages_block(zone, page, start_type);
1962 /* Claim the whole block if over half of it is free */
1963 if (pages >= (1 << (pageblock_order-1)) ||
1964 page_group_by_mobility_disabled)
1965 set_pageblock_migratetype(page, start_type);
1969 * Check whether there is a suitable fallback freepage with requested order.
1970 * If only_stealable is true, this function returns fallback_mt only if
1971 * we can steal other freepages all together. This would help to reduce
1972 * fragmentation due to mixed migratetype pages in one pageblock.
1974 int find_suitable_fallback(struct free_area *area, unsigned int order,
1975 int migratetype, bool only_stealable, bool *can_steal)
1980 if (area->nr_free == 0)
1985 fallback_mt = fallbacks[migratetype][i];
1986 if (fallback_mt == MIGRATE_TYPES)
1989 if (list_empty(&area->free_list[fallback_mt]))
1992 if (can_steal_fallback(order, migratetype))
1995 if (!only_stealable)
2006 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2007 * there are no empty page blocks that contain a page with a suitable order
2009 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2010 unsigned int alloc_order)
2013 unsigned long max_managed, flags;
2016 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2017 * Check is race-prone but harmless.
2019 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2020 if (zone->nr_reserved_highatomic >= max_managed)
2023 spin_lock_irqsave(&zone->lock, flags);
2025 /* Recheck the nr_reserved_highatomic limit under the lock */
2026 if (zone->nr_reserved_highatomic >= max_managed)
2030 mt = get_pageblock_migratetype(page);
2031 if (mt != MIGRATE_HIGHATOMIC &&
2032 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
2033 zone->nr_reserved_highatomic += pageblock_nr_pages;
2034 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2035 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
2039 spin_unlock_irqrestore(&zone->lock, flags);
2043 * Used when an allocation is about to fail under memory pressure. This
2044 * potentially hurts the reliability of high-order allocations when under
2045 * intense memory pressure but failed atomic allocations should be easier
2046 * to recover from than an OOM.
2048 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
2050 struct zonelist *zonelist = ac->zonelist;
2051 unsigned long flags;
2057 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2059 /* Preserve at least one pageblock */
2060 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
2063 spin_lock_irqsave(&zone->lock, flags);
2064 for (order = 0; order < MAX_ORDER; order++) {
2065 struct free_area *area = &(zone->free_area[order]);
2067 page = list_first_entry_or_null(
2068 &area->free_list[MIGRATE_HIGHATOMIC],
2074 * It should never happen but changes to locking could
2075 * inadvertently allow a per-cpu drain to add pages
2076 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2077 * and watch for underflows.
2079 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
2080 zone->nr_reserved_highatomic);
2083 * Convert to ac->migratetype and avoid the normal
2084 * pageblock stealing heuristics. Minimally, the caller
2085 * is doing the work and needs the pages. More
2086 * importantly, if the block was always converted to
2087 * MIGRATE_UNMOVABLE or another type then the number
2088 * of pageblocks that cannot be completely freed
2091 set_pageblock_migratetype(page, ac->migratetype);
2092 move_freepages_block(zone, page, ac->migratetype);
2093 spin_unlock_irqrestore(&zone->lock, flags);
2096 spin_unlock_irqrestore(&zone->lock, flags);
2100 /* Remove an element from the buddy allocator from the fallback list */
2101 static inline struct page *
2102 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
2104 struct free_area *area;
2105 unsigned int current_order;
2110 /* Find the largest possible block of pages in the other list */
2111 for (current_order = MAX_ORDER-1;
2112 current_order >= order && current_order <= MAX_ORDER-1;
2114 area = &(zone->free_area[current_order]);
2115 fallback_mt = find_suitable_fallback(area, current_order,
2116 start_migratetype, false, &can_steal);
2117 if (fallback_mt == -1)
2120 page = list_first_entry(&area->free_list[fallback_mt],
2123 steal_suitable_fallback(zone, page, start_migratetype);
2125 /* Remove the page from the freelists */
2127 list_del(&page->lru);
2128 rmv_page_order(page);
2130 expand(zone, page, order, current_order, area,
2133 * The pcppage_migratetype may differ from pageblock's
2134 * migratetype depending on the decisions in
2135 * find_suitable_fallback(). This is OK as long as it does not
2136 * differ for MIGRATE_CMA pageblocks. Those can be used as
2137 * fallback only via special __rmqueue_cma_fallback() function
2139 set_pcppage_migratetype(page, start_migratetype);
2141 trace_mm_page_alloc_extfrag(page, order, current_order,
2142 start_migratetype, fallback_mt);
2151 * Do the hard work of removing an element from the buddy allocator.
2152 * Call me with the zone->lock already held.
2154 static struct page *__rmqueue(struct zone *zone, unsigned int order,
2159 page = __rmqueue_smallest(zone, order, migratetype);
2160 if (unlikely(!page)) {
2161 if (migratetype == MIGRATE_MOVABLE)
2162 page = __rmqueue_cma_fallback(zone, order);
2165 page = __rmqueue_fallback(zone, order, migratetype);
2168 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2173 * Obtain a specified number of elements from the buddy allocator, all under
2174 * a single hold of the lock, for efficiency. Add them to the supplied list.
2175 * Returns the number of new pages which were placed at *list.
2177 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2178 unsigned long count, struct list_head *list,
2179 int migratetype, bool cold)
2183 spin_lock(&zone->lock);
2184 for (i = 0; i < count; ++i) {
2185 struct page *page = __rmqueue(zone, order, migratetype);
2186 if (unlikely(page == NULL))
2189 if (unlikely(check_pcp_refill(page)))
2193 * Split buddy pages returned by expand() are received here
2194 * in physical page order. The page is added to the callers and
2195 * list and the list head then moves forward. From the callers
2196 * perspective, the linked list is ordered by page number in
2197 * some conditions. This is useful for IO devices that can
2198 * merge IO requests if the physical pages are ordered
2202 list_add(&page->lru, list);
2204 list_add_tail(&page->lru, list);
2206 if (is_migrate_cma(get_pcppage_migratetype(page)))
2207 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2210 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2211 spin_unlock(&zone->lock);
2217 * Called from the vmstat counter updater to drain pagesets of this
2218 * currently executing processor on remote nodes after they have
2221 * Note that this function must be called with the thread pinned to
2222 * a single processor.
2224 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2226 unsigned long flags;
2227 int to_drain, batch;
2229 local_irq_save(flags);
2230 batch = READ_ONCE(pcp->batch);
2231 to_drain = min(pcp->count, batch);
2233 free_pcppages_bulk(zone, to_drain, pcp);
2234 pcp->count -= to_drain;
2236 local_irq_restore(flags);
2241 * Drain pcplists of the indicated processor and zone.
2243 * The processor must either be the current processor and the
2244 * thread pinned to the current processor or a processor that
2247 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2249 unsigned long flags;
2250 struct per_cpu_pageset *pset;
2251 struct per_cpu_pages *pcp;
2253 local_irq_save(flags);
2254 pset = per_cpu_ptr(zone->pageset, cpu);
2258 free_pcppages_bulk(zone, pcp->count, pcp);
2261 local_irq_restore(flags);
2265 * Drain pcplists of all zones on the indicated processor.
2267 * The processor must either be the current processor and the
2268 * thread pinned to the current processor or a processor that
2271 static void drain_pages(unsigned int cpu)
2275 for_each_populated_zone(zone) {
2276 drain_pages_zone(cpu, zone);
2281 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2283 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2284 * the single zone's pages.
2286 void drain_local_pages(struct zone *zone)
2288 int cpu = smp_processor_id();
2291 drain_pages_zone(cpu, zone);
2297 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2299 * When zone parameter is non-NULL, spill just the single zone's pages.
2301 * Note that this code is protected against sending an IPI to an offline
2302 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2303 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2304 * nothing keeps CPUs from showing up after we populated the cpumask and
2305 * before the call to on_each_cpu_mask().
2307 void drain_all_pages(struct zone *zone)
2312 * Allocate in the BSS so we wont require allocation in
2313 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2315 static cpumask_t cpus_with_pcps;
2318 * We don't care about racing with CPU hotplug event
2319 * as offline notification will cause the notified
2320 * cpu to drain that CPU pcps and on_each_cpu_mask
2321 * disables preemption as part of its processing
2323 for_each_online_cpu(cpu) {
2324 struct per_cpu_pageset *pcp;
2326 bool has_pcps = false;
2329 pcp = per_cpu_ptr(zone->pageset, cpu);
2333 for_each_populated_zone(z) {
2334 pcp = per_cpu_ptr(z->pageset, cpu);
2335 if (pcp->pcp.count) {
2343 cpumask_set_cpu(cpu, &cpus_with_pcps);
2345 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2347 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2351 #ifdef CONFIG_HIBERNATION
2353 void mark_free_pages(struct zone *zone)
2355 unsigned long pfn, max_zone_pfn;
2356 unsigned long flags;
2357 unsigned int order, t;
2360 if (zone_is_empty(zone))
2363 spin_lock_irqsave(&zone->lock, flags);
2365 max_zone_pfn = zone_end_pfn(zone);
2366 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2367 if (pfn_valid(pfn)) {
2368 page = pfn_to_page(pfn);
2370 if (page_zone(page) != zone)
2373 if (!swsusp_page_is_forbidden(page))
2374 swsusp_unset_page_free(page);
2377 for_each_migratetype_order(order, t) {
2378 list_for_each_entry(page,
2379 &zone->free_area[order].free_list[t], lru) {
2382 pfn = page_to_pfn(page);
2383 for (i = 0; i < (1UL << order); i++)
2384 swsusp_set_page_free(pfn_to_page(pfn + i));
2387 spin_unlock_irqrestore(&zone->lock, flags);
2389 #endif /* CONFIG_PM */
2392 * Free a 0-order page
2393 * cold == true ? free a cold page : free a hot page
2395 void free_hot_cold_page(struct page *page, bool cold)
2397 struct zone *zone = page_zone(page);
2398 struct per_cpu_pages *pcp;
2399 unsigned long flags;
2400 unsigned long pfn = page_to_pfn(page);
2403 if (!free_pcp_prepare(page))
2406 migratetype = get_pfnblock_migratetype(page, pfn);
2407 set_pcppage_migratetype(page, migratetype);
2408 local_irq_save(flags);
2409 __count_vm_event(PGFREE);
2412 * We only track unmovable, reclaimable and movable on pcp lists.
2413 * Free ISOLATE pages back to the allocator because they are being
2414 * offlined but treat RESERVE as movable pages so we can get those
2415 * areas back if necessary. Otherwise, we may have to free
2416 * excessively into the page allocator
2418 if (migratetype >= MIGRATE_PCPTYPES) {
2419 if (unlikely(is_migrate_isolate(migratetype))) {
2420 free_one_page(zone, page, pfn, 0, migratetype);
2423 migratetype = MIGRATE_MOVABLE;
2426 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2428 list_add(&page->lru, &pcp->lists[migratetype]);
2430 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2432 if (pcp->count >= pcp->high) {
2433 unsigned long batch = READ_ONCE(pcp->batch);
2434 free_pcppages_bulk(zone, batch, pcp);
2435 pcp->count -= batch;
2439 local_irq_restore(flags);
2443 * Free a list of 0-order pages
2445 void free_hot_cold_page_list(struct list_head *list, bool cold)
2447 struct page *page, *next;
2449 list_for_each_entry_safe(page, next, list, lru) {
2450 trace_mm_page_free_batched(page, cold);
2451 free_hot_cold_page(page, cold);
2456 * split_page takes a non-compound higher-order page, and splits it into
2457 * n (1<<order) sub-pages: page[0..n]
2458 * Each sub-page must be freed individually.
2460 * Note: this is probably too low level an operation for use in drivers.
2461 * Please consult with lkml before using this in your driver.
2463 void split_page(struct page *page, unsigned int order)
2468 VM_BUG_ON_PAGE(PageCompound(page), page);
2469 VM_BUG_ON_PAGE(!page_count(page), page);
2471 #ifdef CONFIG_KMEMCHECK
2473 * Split shadow pages too, because free(page[0]) would
2474 * otherwise free the whole shadow.
2476 if (kmemcheck_page_is_tracked(page))
2477 split_page(virt_to_page(page[0].shadow), order);
2480 gfp_mask = get_page_owner_gfp(page);
2481 set_page_owner(page, 0, gfp_mask);
2482 for (i = 1; i < (1 << order); i++) {
2483 set_page_refcounted(page + i);
2484 set_page_owner(page + i, 0, gfp_mask);
2487 EXPORT_SYMBOL_GPL(split_page);
2489 int __isolate_free_page(struct page *page, unsigned int order)
2491 unsigned long watermark;
2495 BUG_ON(!PageBuddy(page));
2497 zone = page_zone(page);
2498 mt = get_pageblock_migratetype(page);
2500 if (!is_migrate_isolate(mt)) {
2501 /* Obey watermarks as if the page was being allocated */
2502 watermark = low_wmark_pages(zone) + (1 << order);
2503 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2506 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2509 /* Remove page from free list */
2510 list_del(&page->lru);
2511 zone->free_area[order].nr_free--;
2512 rmv_page_order(page);
2514 set_page_owner(page, order, __GFP_MOVABLE);
2516 /* Set the pageblock if the isolated page is at least a pageblock */
2517 if (order >= pageblock_order - 1) {
2518 struct page *endpage = page + (1 << order) - 1;
2519 for (; page < endpage; page += pageblock_nr_pages) {
2520 int mt = get_pageblock_migratetype(page);
2521 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2522 set_pageblock_migratetype(page,
2528 return 1UL << order;
2532 * Similar to split_page except the page is already free. As this is only
2533 * being used for migration, the migratetype of the block also changes.
2534 * As this is called with interrupts disabled, the caller is responsible
2535 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2538 * Note: this is probably too low level an operation for use in drivers.
2539 * Please consult with lkml before using this in your driver.
2541 int split_free_page(struct page *page)
2546 order = page_order(page);
2548 nr_pages = __isolate_free_page(page, order);
2552 /* Split into individual pages */
2553 set_page_refcounted(page);
2554 split_page(page, order);
2559 * Update NUMA hit/miss statistics
2561 * Must be called with interrupts disabled.
2563 * When __GFP_OTHER_NODE is set assume the node of the preferred
2564 * zone is the local node. This is useful for daemons who allocate
2565 * memory on behalf of other processes.
2567 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2571 int local_nid = numa_node_id();
2572 enum zone_stat_item local_stat = NUMA_LOCAL;
2574 if (unlikely(flags & __GFP_OTHER_NODE)) {
2575 local_stat = NUMA_OTHER;
2576 local_nid = preferred_zone->node;
2579 if (z->node == local_nid) {
2580 __inc_zone_state(z, NUMA_HIT);
2581 __inc_zone_state(z, local_stat);
2583 __inc_zone_state(z, NUMA_MISS);
2584 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2590 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2593 struct page *buffered_rmqueue(struct zone *preferred_zone,
2594 struct zone *zone, unsigned int order,
2595 gfp_t gfp_flags, unsigned int alloc_flags,
2598 unsigned long flags;
2600 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2602 if (likely(order == 0)) {
2603 struct per_cpu_pages *pcp;
2604 struct list_head *list;
2606 local_irq_save(flags);
2608 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2609 list = &pcp->lists[migratetype];
2610 if (list_empty(list)) {
2611 pcp->count += rmqueue_bulk(zone, 0,
2614 if (unlikely(list_empty(list)))
2619 page = list_last_entry(list, struct page, lru);
2621 page = list_first_entry(list, struct page, lru);
2622 } while (page && check_new_pcp(page));
2624 __dec_zone_state(zone, NR_ALLOC_BATCH);
2625 list_del(&page->lru);
2629 * We most definitely don't want callers attempting to
2630 * allocate greater than order-1 page units with __GFP_NOFAIL.
2632 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2633 spin_lock_irqsave(&zone->lock, flags);
2637 if (alloc_flags & ALLOC_HARDER) {
2638 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2640 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2643 page = __rmqueue(zone, order, migratetype);
2644 } while (page && check_new_pages(page, order));
2645 spin_unlock(&zone->lock);
2648 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2649 __mod_zone_freepage_state(zone, -(1 << order),
2650 get_pcppage_migratetype(page));
2653 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2654 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2655 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2657 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2658 zone_statistics(preferred_zone, zone, gfp_flags);
2659 local_irq_restore(flags);
2661 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2665 local_irq_restore(flags);
2669 #ifdef CONFIG_FAIL_PAGE_ALLOC
2672 struct fault_attr attr;
2674 bool ignore_gfp_highmem;
2675 bool ignore_gfp_reclaim;
2677 } fail_page_alloc = {
2678 .attr = FAULT_ATTR_INITIALIZER,
2679 .ignore_gfp_reclaim = true,
2680 .ignore_gfp_highmem = true,
2684 static int __init setup_fail_page_alloc(char *str)
2686 return setup_fault_attr(&fail_page_alloc.attr, str);
2688 __setup("fail_page_alloc=", setup_fail_page_alloc);
2690 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2692 if (order < fail_page_alloc.min_order)
2694 if (gfp_mask & __GFP_NOFAIL)
2696 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2698 if (fail_page_alloc.ignore_gfp_reclaim &&
2699 (gfp_mask & __GFP_DIRECT_RECLAIM))
2702 return should_fail(&fail_page_alloc.attr, 1 << order);
2705 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2707 static int __init fail_page_alloc_debugfs(void)
2709 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2712 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2713 &fail_page_alloc.attr);
2715 return PTR_ERR(dir);
2717 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2718 &fail_page_alloc.ignore_gfp_reclaim))
2720 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2721 &fail_page_alloc.ignore_gfp_highmem))
2723 if (!debugfs_create_u32("min-order", mode, dir,
2724 &fail_page_alloc.min_order))
2729 debugfs_remove_recursive(dir);
2734 late_initcall(fail_page_alloc_debugfs);
2736 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2738 #else /* CONFIG_FAIL_PAGE_ALLOC */
2740 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2745 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2748 * Return true if free base pages are above 'mark'. For high-order checks it
2749 * will return true of the order-0 watermark is reached and there is at least
2750 * one free page of a suitable size. Checking now avoids taking the zone lock
2751 * to check in the allocation paths if no pages are free.
2753 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2754 int classzone_idx, unsigned int alloc_flags,
2759 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2761 /* free_pages may go negative - that's OK */
2762 free_pages -= (1 << order) - 1;
2764 if (alloc_flags & ALLOC_HIGH)
2768 * If the caller does not have rights to ALLOC_HARDER then subtract
2769 * the high-atomic reserves. This will over-estimate the size of the
2770 * atomic reserve but it avoids a search.
2772 if (likely(!alloc_harder))
2773 free_pages -= z->nr_reserved_highatomic;
2778 /* If allocation can't use CMA areas don't use free CMA pages */
2779 if (!(alloc_flags & ALLOC_CMA))
2780 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2784 * Check watermarks for an order-0 allocation request. If these
2785 * are not met, then a high-order request also cannot go ahead
2786 * even if a suitable page happened to be free.
2788 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2791 /* If this is an order-0 request then the watermark is fine */
2795 /* For a high-order request, check at least one suitable page is free */
2796 for (o = order; o < MAX_ORDER; o++) {
2797 struct free_area *area = &z->free_area[o];
2806 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2807 if (!list_empty(&area->free_list[mt]))
2812 if ((alloc_flags & ALLOC_CMA) &&
2813 !list_empty(&area->free_list[MIGRATE_CMA])) {
2821 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2822 int classzone_idx, unsigned int alloc_flags)
2824 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2825 zone_page_state(z, NR_FREE_PAGES));
2828 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2829 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2831 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2835 /* If allocation can't use CMA areas don't use free CMA pages */
2836 if (!(alloc_flags & ALLOC_CMA))
2837 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2841 * Fast check for order-0 only. If this fails then the reserves
2842 * need to be calculated. There is a corner case where the check
2843 * passes but only the high-order atomic reserve are free. If
2844 * the caller is !atomic then it'll uselessly search the free
2845 * list. That corner case is then slower but it is harmless.
2847 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2850 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2854 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2855 unsigned long mark, int classzone_idx)
2857 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2859 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2860 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2862 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2867 static bool zone_local(struct zone *local_zone, struct zone *zone)
2869 return local_zone->node == zone->node;
2872 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2874 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2877 #else /* CONFIG_NUMA */
2878 static bool zone_local(struct zone *local_zone, struct zone *zone)
2883 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2887 #endif /* CONFIG_NUMA */
2889 static void reset_alloc_batches(struct zone *preferred_zone)
2891 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2894 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2895 high_wmark_pages(zone) - low_wmark_pages(zone) -
2896 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2897 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2898 } while (zone++ != preferred_zone);
2902 * get_page_from_freelist goes through the zonelist trying to allocate
2905 static struct page *
2906 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2907 const struct alloc_context *ac)
2909 struct zoneref *z = ac->preferred_zoneref;
2911 bool fair_skipped = false;
2912 bool apply_fair = (alloc_flags & ALLOC_FAIR);
2916 * Scan zonelist, looking for a zone with enough free.
2917 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2919 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
2924 if (cpusets_enabled() &&
2925 (alloc_flags & ALLOC_CPUSET) &&
2926 !__cpuset_zone_allowed(zone, gfp_mask))
2929 * Distribute pages in proportion to the individual
2930 * zone size to ensure fair page aging. The zone a
2931 * page was allocated in should have no effect on the
2932 * time the page has in memory before being reclaimed.
2935 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2936 fair_skipped = true;
2939 if (!zone_local(ac->preferred_zoneref->zone, zone)) {
2946 * When allocating a page cache page for writing, we
2947 * want to get it from a zone that is within its dirty
2948 * limit, such that no single zone holds more than its
2949 * proportional share of globally allowed dirty pages.
2950 * The dirty limits take into account the zone's
2951 * lowmem reserves and high watermark so that kswapd
2952 * should be able to balance it without having to
2953 * write pages from its LRU list.
2955 * This may look like it could increase pressure on
2956 * lower zones by failing allocations in higher zones
2957 * before they are full. But the pages that do spill
2958 * over are limited as the lower zones are protected
2959 * by this very same mechanism. It should not become
2960 * a practical burden to them.
2962 * XXX: For now, allow allocations to potentially
2963 * exceed the per-zone dirty limit in the slowpath
2964 * (spread_dirty_pages unset) before going into reclaim,
2965 * which is important when on a NUMA setup the allowed
2966 * zones are together not big enough to reach the
2967 * global limit. The proper fix for these situations
2968 * will require awareness of zones in the
2969 * dirty-throttling and the flusher threads.
2971 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2974 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2975 if (!zone_watermark_fast(zone, order, mark,
2976 ac_classzone_idx(ac), alloc_flags)) {
2979 /* Checked here to keep the fast path fast */
2980 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2981 if (alloc_flags & ALLOC_NO_WATERMARKS)
2984 if (zone_reclaim_mode == 0 ||
2985 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
2988 ret = zone_reclaim(zone, gfp_mask, order);
2990 case ZONE_RECLAIM_NOSCAN:
2993 case ZONE_RECLAIM_FULL:
2994 /* scanned but unreclaimable */
2997 /* did we reclaim enough */
2998 if (zone_watermark_ok(zone, order, mark,
2999 ac_classzone_idx(ac), alloc_flags))
3007 page = buffered_rmqueue(ac->preferred_zoneref->zone, zone, order,
3008 gfp_mask, alloc_flags, ac->migratetype);
3010 prep_new_page(page, order, gfp_mask, alloc_flags);
3013 * If this is a high-order atomic allocation then check
3014 * if the pageblock should be reserved for the future
3016 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3017 reserve_highatomic_pageblock(page, zone, order);
3024 * The first pass makes sure allocations are spread fairly within the
3025 * local node. However, the local node might have free pages left
3026 * after the fairness batches are exhausted, and remote zones haven't
3027 * even been considered yet. Try once more without fairness, and
3028 * include remote zones now, before entering the slowpath and waking
3029 * kswapd: prefer spilling to a remote zone over swapping locally.
3034 fair_skipped = false;
3035 reset_alloc_batches(ac->preferred_zoneref->zone);
3043 * Large machines with many possible nodes should not always dump per-node
3044 * meminfo in irq context.
3046 static inline bool should_suppress_show_mem(void)
3051 ret = in_interrupt();
3056 static DEFINE_RATELIMIT_STATE(nopage_rs,
3057 DEFAULT_RATELIMIT_INTERVAL,
3058 DEFAULT_RATELIMIT_BURST);
3060 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
3062 unsigned int filter = SHOW_MEM_FILTER_NODES;
3064 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
3065 debug_guardpage_minorder() > 0)
3069 * This documents exceptions given to allocations in certain
3070 * contexts that are allowed to allocate outside current's set
3073 if (!(gfp_mask & __GFP_NOMEMALLOC))
3074 if (test_thread_flag(TIF_MEMDIE) ||
3075 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3076 filter &= ~SHOW_MEM_FILTER_NODES;
3077 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3078 filter &= ~SHOW_MEM_FILTER_NODES;
3081 struct va_format vaf;
3084 va_start(args, fmt);
3089 pr_warn("%pV", &vaf);
3094 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3095 current->comm, order, gfp_mask, &gfp_mask);
3097 if (!should_suppress_show_mem())
3101 static inline struct page *
3102 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3103 const struct alloc_context *ac, unsigned long *did_some_progress)
3105 struct oom_control oc = {
3106 .zonelist = ac->zonelist,
3107 .nodemask = ac->nodemask,
3108 .gfp_mask = gfp_mask,
3113 *did_some_progress = 0;
3116 * Acquire the oom lock. If that fails, somebody else is
3117 * making progress for us.
3119 if (!mutex_trylock(&oom_lock)) {
3120 *did_some_progress = 1;
3121 schedule_timeout_uninterruptible(1);
3126 * Go through the zonelist yet one more time, keep very high watermark
3127 * here, this is only to catch a parallel oom killing, we must fail if
3128 * we're still under heavy pressure.
3130 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3131 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3135 if (!(gfp_mask & __GFP_NOFAIL)) {
3136 /* Coredumps can quickly deplete all memory reserves */
3137 if (current->flags & PF_DUMPCORE)
3139 /* The OOM killer will not help higher order allocs */
3140 if (order > PAGE_ALLOC_COSTLY_ORDER)
3142 /* The OOM killer does not needlessly kill tasks for lowmem */
3143 if (ac->high_zoneidx < ZONE_NORMAL)
3145 if (pm_suspended_storage())
3148 * XXX: GFP_NOFS allocations should rather fail than rely on
3149 * other request to make a forward progress.
3150 * We are in an unfortunate situation where out_of_memory cannot
3151 * do much for this context but let's try it to at least get
3152 * access to memory reserved if the current task is killed (see
3153 * out_of_memory). Once filesystems are ready to handle allocation
3154 * failures more gracefully we should just bail out here.
3157 /* The OOM killer may not free memory on a specific node */
3158 if (gfp_mask & __GFP_THISNODE)
3161 /* Exhausted what can be done so it's blamo time */
3162 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3163 *did_some_progress = 1;
3165 if (gfp_mask & __GFP_NOFAIL) {
3166 page = get_page_from_freelist(gfp_mask, order,
3167 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
3169 * fallback to ignore cpuset restriction if our nodes
3173 page = get_page_from_freelist(gfp_mask, order,
3174 ALLOC_NO_WATERMARKS, ac);
3178 mutex_unlock(&oom_lock);
3184 * Maximum number of compaction retries wit a progress before OOM
3185 * killer is consider as the only way to move forward.
3187 #define MAX_COMPACT_RETRIES 16
3189 #ifdef CONFIG_COMPACTION
3190 /* Try memory compaction for high-order allocations before reclaim */
3191 static struct page *
3192 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3193 unsigned int alloc_flags, const struct alloc_context *ac,
3194 enum migrate_mode mode, enum compact_result *compact_result)
3197 int contended_compaction;
3202 current->flags |= PF_MEMALLOC;
3203 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3204 mode, &contended_compaction);
3205 current->flags &= ~PF_MEMALLOC;
3207 if (*compact_result <= COMPACT_INACTIVE)
3211 * At least in one zone compaction wasn't deferred or skipped, so let's
3212 * count a compaction stall
3214 count_vm_event(COMPACTSTALL);
3216 page = get_page_from_freelist(gfp_mask, order,
3217 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3220 struct zone *zone = page_zone(page);
3222 zone->compact_blockskip_flush = false;
3223 compaction_defer_reset(zone, order, true);
3224 count_vm_event(COMPACTSUCCESS);
3229 * It's bad if compaction run occurs and fails. The most likely reason
3230 * is that pages exist, but not enough to satisfy watermarks.
3232 count_vm_event(COMPACTFAIL);
3235 * In all zones where compaction was attempted (and not
3236 * deferred or skipped), lock contention has been detected.
3237 * For THP allocation we do not want to disrupt the others
3238 * so we fallback to base pages instead.
3240 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3241 *compact_result = COMPACT_CONTENDED;
3244 * If compaction was aborted due to need_resched(), we do not
3245 * want to further increase allocation latency, unless it is
3246 * khugepaged trying to collapse.
3248 if (contended_compaction == COMPACT_CONTENDED_SCHED
3249 && !(current->flags & PF_KTHREAD))
3250 *compact_result = COMPACT_CONTENDED;
3258 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3259 enum compact_result compact_result, enum migrate_mode *migrate_mode,
3260 int compaction_retries)
3262 int max_retries = MAX_COMPACT_RETRIES;
3268 * compaction considers all the zone as desperately out of memory
3269 * so it doesn't really make much sense to retry except when the
3270 * failure could be caused by weak migration mode.
3272 if (compaction_failed(compact_result)) {
3273 if (*migrate_mode == MIGRATE_ASYNC) {
3274 *migrate_mode = MIGRATE_SYNC_LIGHT;
3281 * make sure the compaction wasn't deferred or didn't bail out early
3282 * due to locks contention before we declare that we should give up.
3283 * But do not retry if the given zonelist is not suitable for
3286 if (compaction_withdrawn(compact_result))
3287 return compaction_zonelist_suitable(ac, order, alloc_flags);
3290 * !costly requests are much more important than __GFP_REPEAT
3291 * costly ones because they are de facto nofail and invoke OOM
3292 * killer to move on while costly can fail and users are ready
3293 * to cope with that. 1/4 retries is rather arbitrary but we
3294 * would need much more detailed feedback from compaction to
3295 * make a better decision.
3297 if (order > PAGE_ALLOC_COSTLY_ORDER)
3299 if (compaction_retries <= max_retries)
3305 static inline struct page *
3306 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3307 unsigned int alloc_flags, const struct alloc_context *ac,
3308 enum migrate_mode mode, enum compact_result *compact_result)
3310 *compact_result = COMPACT_SKIPPED;
3315 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3316 enum compact_result compact_result,
3317 enum migrate_mode *migrate_mode,
3318 int compaction_retries)
3322 #endif /* CONFIG_COMPACTION */
3324 /* Perform direct synchronous page reclaim */
3326 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3327 const struct alloc_context *ac)
3329 struct reclaim_state reclaim_state;
3334 /* We now go into synchronous reclaim */
3335 cpuset_memory_pressure_bump();
3336 current->flags |= PF_MEMALLOC;
3337 lockdep_set_current_reclaim_state(gfp_mask);
3338 reclaim_state.reclaimed_slab = 0;
3339 current->reclaim_state = &reclaim_state;
3341 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3344 current->reclaim_state = NULL;
3345 lockdep_clear_current_reclaim_state();
3346 current->flags &= ~PF_MEMALLOC;
3353 /* The really slow allocator path where we enter direct reclaim */
3354 static inline struct page *
3355 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3356 unsigned int alloc_flags, const struct alloc_context *ac,
3357 unsigned long *did_some_progress)
3359 struct page *page = NULL;
3360 bool drained = false;
3362 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3363 if (unlikely(!(*did_some_progress)))
3367 page = get_page_from_freelist(gfp_mask, order,
3368 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3371 * If an allocation failed after direct reclaim, it could be because
3372 * pages are pinned on the per-cpu lists or in high alloc reserves.
3373 * Shrink them them and try again
3375 if (!page && !drained) {
3376 unreserve_highatomic_pageblock(ac);
3377 drain_all_pages(NULL);
3385 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3390 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3391 ac->high_zoneidx, ac->nodemask)
3392 wakeup_kswapd(zone, order, ac_classzone_idx(ac));
3395 static inline unsigned int
3396 gfp_to_alloc_flags(gfp_t gfp_mask)
3398 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3400 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3401 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3404 * The caller may dip into page reserves a bit more if the caller
3405 * cannot run direct reclaim, or if the caller has realtime scheduling
3406 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3407 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3409 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3411 if (gfp_mask & __GFP_ATOMIC) {
3413 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3414 * if it can't schedule.
3416 if (!(gfp_mask & __GFP_NOMEMALLOC))
3417 alloc_flags |= ALLOC_HARDER;
3419 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3420 * comment for __cpuset_node_allowed().
3422 alloc_flags &= ~ALLOC_CPUSET;
3423 } else if (unlikely(rt_task(current)) && !in_interrupt())
3424 alloc_flags |= ALLOC_HARDER;
3426 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3427 if (gfp_mask & __GFP_MEMALLOC)
3428 alloc_flags |= ALLOC_NO_WATERMARKS;
3429 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3430 alloc_flags |= ALLOC_NO_WATERMARKS;
3431 else if (!in_interrupt() &&
3432 ((current->flags & PF_MEMALLOC) ||
3433 unlikely(test_thread_flag(TIF_MEMDIE))))
3434 alloc_flags |= ALLOC_NO_WATERMARKS;
3437 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3438 alloc_flags |= ALLOC_CMA;
3443 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3445 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3448 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3450 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3454 * Maximum number of reclaim retries without any progress before OOM killer
3455 * is consider as the only way to move forward.
3457 #define MAX_RECLAIM_RETRIES 16
3460 * Checks whether it makes sense to retry the reclaim to make a forward progress
3461 * for the given allocation request.
3462 * The reclaim feedback represented by did_some_progress (any progress during
3463 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3464 * any progress in a row) is considered as well as the reclaimable pages on the
3465 * applicable zone list (with a backoff mechanism which is a function of
3466 * no_progress_loops).
3468 * Returns true if a retry is viable or false to enter the oom path.
3471 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3472 struct alloc_context *ac, int alloc_flags,
3473 bool did_some_progress, int no_progress_loops)
3479 * Make sure we converge to OOM if we cannot make any progress
3480 * several times in the row.
3482 if (no_progress_loops > MAX_RECLAIM_RETRIES)
3486 * Keep reclaiming pages while there is a chance this will lead somewhere.
3487 * If none of the target zones can satisfy our allocation request even
3488 * if all reclaimable pages are considered then we are screwed and have
3491 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3493 unsigned long available;
3494 unsigned long reclaimable;
3496 available = reclaimable = zone_reclaimable_pages(zone);
3497 available -= DIV_ROUND_UP(no_progress_loops * available,
3498 MAX_RECLAIM_RETRIES);
3499 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3502 * Would the allocation succeed if we reclaimed the whole
3505 if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
3506 ac_classzone_idx(ac), alloc_flags, available)) {
3508 * If we didn't make any progress and have a lot of
3509 * dirty + writeback pages then we should wait for
3510 * an IO to complete to slow down the reclaim and
3511 * prevent from pre mature OOM
3513 if (!did_some_progress) {
3514 unsigned long writeback;
3515 unsigned long dirty;
3517 writeback = zone_page_state_snapshot(zone,
3519 dirty = zone_page_state_snapshot(zone, NR_FILE_DIRTY);
3521 if (2*(writeback + dirty) > reclaimable) {
3522 congestion_wait(BLK_RW_ASYNC, HZ/10);
3528 * Memory allocation/reclaim might be called from a WQ
3529 * context and the current implementation of the WQ
3530 * concurrency control doesn't recognize that
3531 * a particular WQ is congested if the worker thread is
3532 * looping without ever sleeping. Therefore we have to
3533 * do a short sleep here rather than calling
3536 if (current->flags & PF_WQ_WORKER)
3537 schedule_timeout_uninterruptible(1);
3548 static inline struct page *
3549 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3550 struct alloc_context *ac)
3552 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3553 struct page *page = NULL;
3554 unsigned int alloc_flags;
3555 unsigned long did_some_progress;
3556 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3557 enum compact_result compact_result;
3558 int compaction_retries = 0;
3559 int no_progress_loops = 0;
3562 * In the slowpath, we sanity check order to avoid ever trying to
3563 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3564 * be using allocators in order of preference for an area that is
3567 if (order >= MAX_ORDER) {
3568 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3573 * We also sanity check to catch abuse of atomic reserves being used by
3574 * callers that are not in atomic context.
3576 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3577 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3578 gfp_mask &= ~__GFP_ATOMIC;
3581 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3582 wake_all_kswapds(order, ac);
3585 * OK, we're below the kswapd watermark and have kicked background
3586 * reclaim. Now things get more complex, so set up alloc_flags according
3587 * to how we want to proceed.
3589 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3591 /* This is the last chance, in general, before the goto nopage. */
3592 page = get_page_from_freelist(gfp_mask, order,
3593 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3597 /* Allocate without watermarks if the context allows */
3598 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3600 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3601 * the allocation is high priority and these type of
3602 * allocations are system rather than user orientated
3604 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3605 page = get_page_from_freelist(gfp_mask, order,
3606 ALLOC_NO_WATERMARKS, ac);
3611 /* Caller is not willing to reclaim, we can't balance anything */
3612 if (!can_direct_reclaim) {
3614 * All existing users of the __GFP_NOFAIL are blockable, so warn
3615 * of any new users that actually allow this type of allocation
3618 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3622 /* Avoid recursion of direct reclaim */
3623 if (current->flags & PF_MEMALLOC) {
3625 * __GFP_NOFAIL request from this context is rather bizarre
3626 * because we cannot reclaim anything and only can loop waiting
3627 * for somebody to do a work for us.
3629 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3636 /* Avoid allocations with no watermarks from looping endlessly */
3637 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3641 * Try direct compaction. The first pass is asynchronous. Subsequent
3642 * attempts after direct reclaim are synchronous
3644 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3650 /* Checks for THP-specific high-order allocations */
3651 if (is_thp_gfp_mask(gfp_mask)) {
3653 * If compaction is deferred for high-order allocations, it is
3654 * because sync compaction recently failed. If this is the case
3655 * and the caller requested a THP allocation, we do not want
3656 * to heavily disrupt the system, so we fail the allocation
3657 * instead of entering direct reclaim.
3659 if (compact_result == COMPACT_DEFERRED)
3663 * Compaction is contended so rather back off than cause
3666 if(compact_result == COMPACT_CONTENDED)
3670 if (order && compaction_made_progress(compact_result))
3671 compaction_retries++;
3673 /* Try direct reclaim and then allocating */
3674 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3675 &did_some_progress);
3679 /* Do not loop if specifically requested */
3680 if (gfp_mask & __GFP_NORETRY)
3684 * Do not retry costly high order allocations unless they are
3687 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
3691 * Costly allocations might have made a progress but this doesn't mean
3692 * their order will become available due to high fragmentation so
3693 * always increment the no progress counter for them
3695 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3696 no_progress_loops = 0;
3698 no_progress_loops++;
3700 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
3701 did_some_progress > 0, no_progress_loops))
3705 * It doesn't make any sense to retry for the compaction if the order-0
3706 * reclaim is not able to make any progress because the current
3707 * implementation of the compaction depends on the sufficient amount
3708 * of free memory (see __compaction_suitable)
3710 if (did_some_progress > 0 &&
3711 should_compact_retry(ac, order, alloc_flags,
3712 compact_result, &migration_mode,
3713 compaction_retries))
3716 /* Reclaim has failed us, start killing things */
3717 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3721 /* Retry as long as the OOM killer is making progress */
3722 if (did_some_progress) {
3723 no_progress_loops = 0;
3729 * High-order allocations do not necessarily loop after direct reclaim
3730 * and reclaim/compaction depends on compaction being called after
3731 * reclaim so call directly if necessary.
3732 * It can become very expensive to allocate transparent hugepages at
3733 * fault, so use asynchronous memory compaction for THP unless it is
3734 * khugepaged trying to collapse. All other requests should tolerate
3735 * at least light sync migration.
3737 if (is_thp_gfp_mask(gfp_mask) && !(current->flags & PF_KTHREAD))
3738 migration_mode = MIGRATE_ASYNC;
3740 migration_mode = MIGRATE_SYNC_LIGHT;
3741 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3747 warn_alloc_failed(gfp_mask, order, NULL);
3753 * This is the 'heart' of the zoned buddy allocator.
3756 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3757 struct zonelist *zonelist, nodemask_t *nodemask)
3760 unsigned int cpuset_mems_cookie;
3761 unsigned int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR;
3762 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3763 struct alloc_context ac = {
3764 .high_zoneidx = gfp_zone(gfp_mask),
3765 .zonelist = zonelist,
3766 .nodemask = nodemask,
3767 .migratetype = gfpflags_to_migratetype(gfp_mask),
3770 if (cpusets_enabled()) {
3771 alloc_mask |= __GFP_HARDWALL;
3772 alloc_flags |= ALLOC_CPUSET;
3774 ac.nodemask = &cpuset_current_mems_allowed;
3777 gfp_mask &= gfp_allowed_mask;
3779 lockdep_trace_alloc(gfp_mask);
3781 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3783 if (should_fail_alloc_page(gfp_mask, order))
3787 * Check the zones suitable for the gfp_mask contain at least one
3788 * valid zone. It's possible to have an empty zonelist as a result
3789 * of __GFP_THISNODE and a memoryless node
3791 if (unlikely(!zonelist->_zonerefs->zone))
3794 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3795 alloc_flags |= ALLOC_CMA;
3798 cpuset_mems_cookie = read_mems_allowed_begin();
3800 /* Dirty zone balancing only done in the fast path */
3801 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3803 /* The preferred zone is used for statistics later */
3804 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3805 ac.high_zoneidx, ac.nodemask);
3806 if (!ac.preferred_zoneref) {
3811 /* First allocation attempt */
3812 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3817 * Runtime PM, block IO and its error handling path can deadlock
3818 * because I/O on the device might not complete.
3820 alloc_mask = memalloc_noio_flags(gfp_mask);
3821 ac.spread_dirty_pages = false;
3824 * Restore the original nodemask if it was potentially replaced with
3825 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3827 if (cpusets_enabled())
3828 ac.nodemask = nodemask;
3829 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3833 * When updating a task's mems_allowed, it is possible to race with
3834 * parallel threads in such a way that an allocation can fail while
3835 * the mask is being updated. If a page allocation is about to fail,
3836 * check if the cpuset changed during allocation and if so, retry.
3838 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3839 alloc_mask = gfp_mask;
3844 if (kmemcheck_enabled && page)
3845 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3847 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3851 EXPORT_SYMBOL(__alloc_pages_nodemask);
3854 * Common helper functions.
3856 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3861 * __get_free_pages() returns a 32-bit address, which cannot represent
3864 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3866 page = alloc_pages(gfp_mask, order);
3869 return (unsigned long) page_address(page);
3871 EXPORT_SYMBOL(__get_free_pages);
3873 unsigned long get_zeroed_page(gfp_t gfp_mask)
3875 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3877 EXPORT_SYMBOL(get_zeroed_page);
3879 void __free_pages(struct page *page, unsigned int order)
3881 if (put_page_testzero(page)) {
3883 free_hot_cold_page(page, false);
3885 __free_pages_ok(page, order);
3889 EXPORT_SYMBOL(__free_pages);
3891 void free_pages(unsigned long addr, unsigned int order)
3894 VM_BUG_ON(!virt_addr_valid((void *)addr));
3895 __free_pages(virt_to_page((void *)addr), order);
3899 EXPORT_SYMBOL(free_pages);
3903 * An arbitrary-length arbitrary-offset area of memory which resides
3904 * within a 0 or higher order page. Multiple fragments within that page
3905 * are individually refcounted, in the page's reference counter.
3907 * The page_frag functions below provide a simple allocation framework for
3908 * page fragments. This is used by the network stack and network device
3909 * drivers to provide a backing region of memory for use as either an
3910 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3912 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3915 struct page *page = NULL;
3916 gfp_t gfp = gfp_mask;
3918 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3919 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3921 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3922 PAGE_FRAG_CACHE_MAX_ORDER);
3923 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3925 if (unlikely(!page))
3926 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3928 nc->va = page ? page_address(page) : NULL;
3933 void *__alloc_page_frag(struct page_frag_cache *nc,
3934 unsigned int fragsz, gfp_t gfp_mask)
3936 unsigned int size = PAGE_SIZE;
3940 if (unlikely(!nc->va)) {
3942 page = __page_frag_refill(nc, gfp_mask);
3946 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3947 /* if size can vary use size else just use PAGE_SIZE */
3950 /* Even if we own the page, we do not use atomic_set().
3951 * This would break get_page_unless_zero() users.
3953 page_ref_add(page, size - 1);
3955 /* reset page count bias and offset to start of new frag */
3956 nc->pfmemalloc = page_is_pfmemalloc(page);
3957 nc->pagecnt_bias = size;
3961 offset = nc->offset - fragsz;
3962 if (unlikely(offset < 0)) {
3963 page = virt_to_page(nc->va);
3965 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3968 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3969 /* if size can vary use size else just use PAGE_SIZE */
3972 /* OK, page count is 0, we can safely set it */
3973 set_page_count(page, size);
3975 /* reset page count bias and offset to start of new frag */
3976 nc->pagecnt_bias = size;
3977 offset = size - fragsz;
3981 nc->offset = offset;
3983 return nc->va + offset;
3985 EXPORT_SYMBOL(__alloc_page_frag);
3988 * Frees a page fragment allocated out of either a compound or order 0 page.
3990 void __free_page_frag(void *addr)
3992 struct page *page = virt_to_head_page(addr);
3994 if (unlikely(put_page_testzero(page)))
3995 __free_pages_ok(page, compound_order(page));
3997 EXPORT_SYMBOL(__free_page_frag);
4000 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
4001 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
4002 * equivalent to alloc_pages.
4004 * It should be used when the caller would like to use kmalloc, but since the
4005 * allocation is large, it has to fall back to the page allocator.
4007 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
4011 page = alloc_pages(gfp_mask, order);
4012 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
4013 __free_pages(page, order);
4019 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
4023 page = alloc_pages_node(nid, gfp_mask, order);
4024 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
4025 __free_pages(page, order);
4032 * __free_kmem_pages and free_kmem_pages will free pages allocated with
4035 void __free_kmem_pages(struct page *page, unsigned int order)
4037 memcg_kmem_uncharge(page, order);
4038 __free_pages(page, order);
4041 void free_kmem_pages(unsigned long addr, unsigned int order)
4044 VM_BUG_ON(!virt_addr_valid((void *)addr));
4045 __free_kmem_pages(virt_to_page((void *)addr), order);
4049 static void *make_alloc_exact(unsigned long addr, unsigned int order,
4053 unsigned long alloc_end = addr + (PAGE_SIZE << order);
4054 unsigned long used = addr + PAGE_ALIGN(size);
4056 split_page(virt_to_page((void *)addr), order);
4057 while (used < alloc_end) {
4062 return (void *)addr;
4066 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4067 * @size: the number of bytes to allocate
4068 * @gfp_mask: GFP flags for the allocation
4070 * This function is similar to alloc_pages(), except that it allocates the
4071 * minimum number of pages to satisfy the request. alloc_pages() can only
4072 * allocate memory in power-of-two pages.
4074 * This function is also limited by MAX_ORDER.
4076 * Memory allocated by this function must be released by free_pages_exact().
4078 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
4080 unsigned int order = get_order(size);
4083 addr = __get_free_pages(gfp_mask, order);
4084 return make_alloc_exact(addr, order, size);
4086 EXPORT_SYMBOL(alloc_pages_exact);
4089 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4091 * @nid: the preferred node ID where memory should be allocated
4092 * @size: the number of bytes to allocate
4093 * @gfp_mask: GFP flags for the allocation
4095 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4098 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4100 unsigned int order = get_order(size);
4101 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4104 return make_alloc_exact((unsigned long)page_address(p), order, size);
4108 * free_pages_exact - release memory allocated via alloc_pages_exact()
4109 * @virt: the value returned by alloc_pages_exact.
4110 * @size: size of allocation, same value as passed to alloc_pages_exact().
4112 * Release the memory allocated by a previous call to alloc_pages_exact.
4114 void free_pages_exact(void *virt, size_t size)
4116 unsigned long addr = (unsigned long)virt;
4117 unsigned long end = addr + PAGE_ALIGN(size);
4119 while (addr < end) {
4124 EXPORT_SYMBOL(free_pages_exact);
4127 * nr_free_zone_pages - count number of pages beyond high watermark
4128 * @offset: The zone index of the highest zone
4130 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4131 * high watermark within all zones at or below a given zone index. For each
4132 * zone, the number of pages is calculated as:
4133 * managed_pages - high_pages
4135 static unsigned long nr_free_zone_pages(int offset)
4140 /* Just pick one node, since fallback list is circular */
4141 unsigned long sum = 0;
4143 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4145 for_each_zone_zonelist(zone, z, zonelist, offset) {
4146 unsigned long size = zone->managed_pages;
4147 unsigned long high = high_wmark_pages(zone);
4156 * nr_free_buffer_pages - count number of pages beyond high watermark
4158 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4159 * watermark within ZONE_DMA and ZONE_NORMAL.
4161 unsigned long nr_free_buffer_pages(void)
4163 return nr_free_zone_pages(gfp_zone(GFP_USER));
4165 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4168 * nr_free_pagecache_pages - count number of pages beyond high watermark
4170 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4171 * high watermark within all zones.
4173 unsigned long nr_free_pagecache_pages(void)
4175 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4178 static inline void show_node(struct zone *zone)
4180 if (IS_ENABLED(CONFIG_NUMA))
4181 printk("Node %d ", zone_to_nid(zone));
4184 long si_mem_available(void)
4187 unsigned long pagecache;
4188 unsigned long wmark_low = 0;
4189 unsigned long pages[NR_LRU_LISTS];
4193 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4194 pages[lru] = global_page_state(NR_LRU_BASE + lru);
4197 wmark_low += zone->watermark[WMARK_LOW];
4200 * Estimate the amount of memory available for userspace allocations,
4201 * without causing swapping.
4203 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
4206 * Not all the page cache can be freed, otherwise the system will
4207 * start swapping. Assume at least half of the page cache, or the
4208 * low watermark worth of cache, needs to stay.
4210 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4211 pagecache -= min(pagecache / 2, wmark_low);
4212 available += pagecache;
4215 * Part of the reclaimable slab consists of items that are in use,
4216 * and cannot be freed. Cap this estimate at the low watermark.
4218 available += global_page_state(NR_SLAB_RECLAIMABLE) -
4219 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
4225 EXPORT_SYMBOL_GPL(si_mem_available);
4227 void si_meminfo(struct sysinfo *val)
4229 val->totalram = totalram_pages;
4230 val->sharedram = global_page_state(NR_SHMEM);
4231 val->freeram = global_page_state(NR_FREE_PAGES);
4232 val->bufferram = nr_blockdev_pages();
4233 val->totalhigh = totalhigh_pages;
4234 val->freehigh = nr_free_highpages();
4235 val->mem_unit = PAGE_SIZE;
4238 EXPORT_SYMBOL(si_meminfo);
4241 void si_meminfo_node(struct sysinfo *val, int nid)
4243 int zone_type; /* needs to be signed */
4244 unsigned long managed_pages = 0;
4245 unsigned long managed_highpages = 0;
4246 unsigned long free_highpages = 0;
4247 pg_data_t *pgdat = NODE_DATA(nid);
4249 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4250 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4251 val->totalram = managed_pages;
4252 val->sharedram = node_page_state(nid, NR_SHMEM);
4253 val->freeram = node_page_state(nid, NR_FREE_PAGES);
4254 #ifdef CONFIG_HIGHMEM
4255 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4256 struct zone *zone = &pgdat->node_zones[zone_type];
4258 if (is_highmem(zone)) {
4259 managed_highpages += zone->managed_pages;
4260 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4263 val->totalhigh = managed_highpages;
4264 val->freehigh = free_highpages;
4266 val->totalhigh = managed_highpages;
4267 val->freehigh = free_highpages;
4269 val->mem_unit = PAGE_SIZE;
4274 * Determine whether the node should be displayed or not, depending on whether
4275 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4277 bool skip_free_areas_node(unsigned int flags, int nid)
4280 unsigned int cpuset_mems_cookie;
4282 if (!(flags & SHOW_MEM_FILTER_NODES))
4286 cpuset_mems_cookie = read_mems_allowed_begin();
4287 ret = !node_isset(nid, cpuset_current_mems_allowed);
4288 } while (read_mems_allowed_retry(cpuset_mems_cookie));
4293 #define K(x) ((x) << (PAGE_SHIFT-10))
4295 static void show_migration_types(unsigned char type)
4297 static const char types[MIGRATE_TYPES] = {
4298 [MIGRATE_UNMOVABLE] = 'U',
4299 [MIGRATE_MOVABLE] = 'M',
4300 [MIGRATE_RECLAIMABLE] = 'E',
4301 [MIGRATE_HIGHATOMIC] = 'H',
4303 [MIGRATE_CMA] = 'C',
4305 #ifdef CONFIG_MEMORY_ISOLATION
4306 [MIGRATE_ISOLATE] = 'I',
4309 char tmp[MIGRATE_TYPES + 1];
4313 for (i = 0; i < MIGRATE_TYPES; i++) {
4314 if (type & (1 << i))
4319 printk("(%s) ", tmp);
4323 * Show free area list (used inside shift_scroll-lock stuff)
4324 * We also calculate the percentage fragmentation. We do this by counting the
4325 * memory on each free list with the exception of the first item on the list.
4328 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4331 void show_free_areas(unsigned int filter)
4333 unsigned long free_pcp = 0;
4337 for_each_populated_zone(zone) {
4338 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4341 for_each_online_cpu(cpu)
4342 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4345 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4346 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4347 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4348 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4349 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4350 " free:%lu free_pcp:%lu free_cma:%lu\n",
4351 global_page_state(NR_ACTIVE_ANON),
4352 global_page_state(NR_INACTIVE_ANON),
4353 global_page_state(NR_ISOLATED_ANON),
4354 global_page_state(NR_ACTIVE_FILE),
4355 global_page_state(NR_INACTIVE_FILE),
4356 global_page_state(NR_ISOLATED_FILE),
4357 global_page_state(NR_UNEVICTABLE),
4358 global_page_state(NR_FILE_DIRTY),
4359 global_page_state(NR_WRITEBACK),
4360 global_page_state(NR_UNSTABLE_NFS),
4361 global_page_state(NR_SLAB_RECLAIMABLE),
4362 global_page_state(NR_SLAB_UNRECLAIMABLE),
4363 global_page_state(NR_FILE_MAPPED),
4364 global_page_state(NR_SHMEM),
4365 global_page_state(NR_PAGETABLE),
4366 global_page_state(NR_BOUNCE),
4367 global_page_state(NR_FREE_PAGES),
4369 global_page_state(NR_FREE_CMA_PAGES));
4371 for_each_populated_zone(zone) {
4374 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4378 for_each_online_cpu(cpu)
4379 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4387 " active_anon:%lukB"
4388 " inactive_anon:%lukB"
4389 " active_file:%lukB"
4390 " inactive_file:%lukB"
4391 " unevictable:%lukB"
4392 " isolated(anon):%lukB"
4393 " isolated(file):%lukB"
4401 " slab_reclaimable:%lukB"
4402 " slab_unreclaimable:%lukB"
4403 " kernel_stack:%lukB"
4410 " writeback_tmp:%lukB"
4411 " pages_scanned:%lu"
4412 " all_unreclaimable? %s"
4415 K(zone_page_state(zone, NR_FREE_PAGES)),
4416 K(min_wmark_pages(zone)),
4417 K(low_wmark_pages(zone)),
4418 K(high_wmark_pages(zone)),
4419 K(zone_page_state(zone, NR_ACTIVE_ANON)),
4420 K(zone_page_state(zone, NR_INACTIVE_ANON)),
4421 K(zone_page_state(zone, NR_ACTIVE_FILE)),
4422 K(zone_page_state(zone, NR_INACTIVE_FILE)),
4423 K(zone_page_state(zone, NR_UNEVICTABLE)),
4424 K(zone_page_state(zone, NR_ISOLATED_ANON)),
4425 K(zone_page_state(zone, NR_ISOLATED_FILE)),
4426 K(zone->present_pages),
4427 K(zone->managed_pages),
4428 K(zone_page_state(zone, NR_MLOCK)),
4429 K(zone_page_state(zone, NR_FILE_DIRTY)),
4430 K(zone_page_state(zone, NR_WRITEBACK)),
4431 K(zone_page_state(zone, NR_FILE_MAPPED)),
4432 K(zone_page_state(zone, NR_SHMEM)),
4433 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4434 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4435 zone_page_state(zone, NR_KERNEL_STACK) *
4437 K(zone_page_state(zone, NR_PAGETABLE)),
4438 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
4439 K(zone_page_state(zone, NR_BOUNCE)),
4441 K(this_cpu_read(zone->pageset->pcp.count)),
4442 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
4443 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
4444 K(zone_page_state(zone, NR_PAGES_SCANNED)),
4445 (!zone_reclaimable(zone) ? "yes" : "no")
4447 printk("lowmem_reserve[]:");
4448 for (i = 0; i < MAX_NR_ZONES; i++)
4449 printk(" %ld", zone->lowmem_reserve[i]);
4453 for_each_populated_zone(zone) {
4455 unsigned long nr[MAX_ORDER], flags, total = 0;
4456 unsigned char types[MAX_ORDER];
4458 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4461 printk("%s: ", zone->name);
4463 spin_lock_irqsave(&zone->lock, flags);
4464 for (order = 0; order < MAX_ORDER; order++) {
4465 struct free_area *area = &zone->free_area[order];
4468 nr[order] = area->nr_free;
4469 total += nr[order] << order;
4472 for (type = 0; type < MIGRATE_TYPES; type++) {
4473 if (!list_empty(&area->free_list[type]))
4474 types[order] |= 1 << type;
4477 spin_unlock_irqrestore(&zone->lock, flags);
4478 for (order = 0; order < MAX_ORDER; order++) {
4479 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4481 show_migration_types(types[order]);
4483 printk("= %lukB\n", K(total));
4486 hugetlb_show_meminfo();
4488 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4490 show_swap_cache_info();
4493 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4495 zoneref->zone = zone;
4496 zoneref->zone_idx = zone_idx(zone);
4500 * Builds allocation fallback zone lists.
4502 * Add all populated zones of a node to the zonelist.
4504 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4508 enum zone_type zone_type = MAX_NR_ZONES;
4512 zone = pgdat->node_zones + zone_type;
4513 if (populated_zone(zone)) {
4514 zoneref_set_zone(zone,
4515 &zonelist->_zonerefs[nr_zones++]);
4516 check_highest_zone(zone_type);
4518 } while (zone_type);
4526 * 0 = automatic detection of better ordering.
4527 * 1 = order by ([node] distance, -zonetype)
4528 * 2 = order by (-zonetype, [node] distance)
4530 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4531 * the same zonelist. So only NUMA can configure this param.
4533 #define ZONELIST_ORDER_DEFAULT 0
4534 #define ZONELIST_ORDER_NODE 1
4535 #define ZONELIST_ORDER_ZONE 2
4537 /* zonelist order in the kernel.
4538 * set_zonelist_order() will set this to NODE or ZONE.
4540 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4541 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4545 /* The value user specified ....changed by config */
4546 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4547 /* string for sysctl */
4548 #define NUMA_ZONELIST_ORDER_LEN 16
4549 char numa_zonelist_order[16] = "default";
4552 * interface for configure zonelist ordering.
4553 * command line option "numa_zonelist_order"
4554 * = "[dD]efault - default, automatic configuration.
4555 * = "[nN]ode - order by node locality, then by zone within node
4556 * = "[zZ]one - order by zone, then by locality within zone
4559 static int __parse_numa_zonelist_order(char *s)
4561 if (*s == 'd' || *s == 'D') {
4562 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4563 } else if (*s == 'n' || *s == 'N') {
4564 user_zonelist_order = ZONELIST_ORDER_NODE;
4565 } else if (*s == 'z' || *s == 'Z') {
4566 user_zonelist_order = ZONELIST_ORDER_ZONE;
4568 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4574 static __init int setup_numa_zonelist_order(char *s)
4581 ret = __parse_numa_zonelist_order(s);
4583 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4587 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4590 * sysctl handler for numa_zonelist_order
4592 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4593 void __user *buffer, size_t *length,
4596 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4598 static DEFINE_MUTEX(zl_order_mutex);
4600 mutex_lock(&zl_order_mutex);
4602 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4606 strcpy(saved_string, (char *)table->data);
4608 ret = proc_dostring(table, write, buffer, length, ppos);
4612 int oldval = user_zonelist_order;
4614 ret = __parse_numa_zonelist_order((char *)table->data);
4617 * bogus value. restore saved string
4619 strncpy((char *)table->data, saved_string,
4620 NUMA_ZONELIST_ORDER_LEN);
4621 user_zonelist_order = oldval;
4622 } else if (oldval != user_zonelist_order) {
4623 mutex_lock(&zonelists_mutex);
4624 build_all_zonelists(NULL, NULL);
4625 mutex_unlock(&zonelists_mutex);
4629 mutex_unlock(&zl_order_mutex);
4634 #define MAX_NODE_LOAD (nr_online_nodes)
4635 static int node_load[MAX_NUMNODES];
4638 * find_next_best_node - find the next node that should appear in a given node's fallback list
4639 * @node: node whose fallback list we're appending
4640 * @used_node_mask: nodemask_t of already used nodes
4642 * We use a number of factors to determine which is the next node that should
4643 * appear on a given node's fallback list. The node should not have appeared
4644 * already in @node's fallback list, and it should be the next closest node
4645 * according to the distance array (which contains arbitrary distance values
4646 * from each node to each node in the system), and should also prefer nodes
4647 * with no CPUs, since presumably they'll have very little allocation pressure
4648 * on them otherwise.
4649 * It returns -1 if no node is found.
4651 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4654 int min_val = INT_MAX;
4655 int best_node = NUMA_NO_NODE;
4656 const struct cpumask *tmp = cpumask_of_node(0);
4658 /* Use the local node if we haven't already */
4659 if (!node_isset(node, *used_node_mask)) {
4660 node_set(node, *used_node_mask);
4664 for_each_node_state(n, N_MEMORY) {
4666 /* Don't want a node to appear more than once */
4667 if (node_isset(n, *used_node_mask))
4670 /* Use the distance array to find the distance */
4671 val = node_distance(node, n);
4673 /* Penalize nodes under us ("prefer the next node") */
4676 /* Give preference to headless and unused nodes */
4677 tmp = cpumask_of_node(n);
4678 if (!cpumask_empty(tmp))
4679 val += PENALTY_FOR_NODE_WITH_CPUS;
4681 /* Slight preference for less loaded node */
4682 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4683 val += node_load[n];
4685 if (val < min_val) {
4692 node_set(best_node, *used_node_mask);
4699 * Build zonelists ordered by node and zones within node.
4700 * This results in maximum locality--normal zone overflows into local
4701 * DMA zone, if any--but risks exhausting DMA zone.
4703 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4706 struct zonelist *zonelist;
4708 zonelist = &pgdat->node_zonelists[0];
4709 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4711 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4712 zonelist->_zonerefs[j].zone = NULL;
4713 zonelist->_zonerefs[j].zone_idx = 0;
4717 * Build gfp_thisnode zonelists
4719 static void build_thisnode_zonelists(pg_data_t *pgdat)
4722 struct zonelist *zonelist;
4724 zonelist = &pgdat->node_zonelists[1];
4725 j = build_zonelists_node(pgdat, zonelist, 0);
4726 zonelist->_zonerefs[j].zone = NULL;
4727 zonelist->_zonerefs[j].zone_idx = 0;
4731 * Build zonelists ordered by zone and nodes within zones.
4732 * This results in conserving DMA zone[s] until all Normal memory is
4733 * exhausted, but results in overflowing to remote node while memory
4734 * may still exist in local DMA zone.
4736 static int node_order[MAX_NUMNODES];
4738 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4741 int zone_type; /* needs to be signed */
4743 struct zonelist *zonelist;
4745 zonelist = &pgdat->node_zonelists[0];
4747 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4748 for (j = 0; j < nr_nodes; j++) {
4749 node = node_order[j];
4750 z = &NODE_DATA(node)->node_zones[zone_type];
4751 if (populated_zone(z)) {
4753 &zonelist->_zonerefs[pos++]);
4754 check_highest_zone(zone_type);
4758 zonelist->_zonerefs[pos].zone = NULL;
4759 zonelist->_zonerefs[pos].zone_idx = 0;
4762 #if defined(CONFIG_64BIT)
4764 * Devices that require DMA32/DMA are relatively rare and do not justify a
4765 * penalty to every machine in case the specialised case applies. Default
4766 * to Node-ordering on 64-bit NUMA machines
4768 static int default_zonelist_order(void)
4770 return ZONELIST_ORDER_NODE;
4774 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4775 * by the kernel. If processes running on node 0 deplete the low memory zone
4776 * then reclaim will occur more frequency increasing stalls and potentially
4777 * be easier to OOM if a large percentage of the zone is under writeback or
4778 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4779 * Hence, default to zone ordering on 32-bit.
4781 static int default_zonelist_order(void)
4783 return ZONELIST_ORDER_ZONE;
4785 #endif /* CONFIG_64BIT */
4787 static void set_zonelist_order(void)
4789 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4790 current_zonelist_order = default_zonelist_order();
4792 current_zonelist_order = user_zonelist_order;
4795 static void build_zonelists(pg_data_t *pgdat)
4798 nodemask_t used_mask;
4799 int local_node, prev_node;
4800 struct zonelist *zonelist;
4801 unsigned int order = current_zonelist_order;
4803 /* initialize zonelists */
4804 for (i = 0; i < MAX_ZONELISTS; i++) {
4805 zonelist = pgdat->node_zonelists + i;
4806 zonelist->_zonerefs[0].zone = NULL;
4807 zonelist->_zonerefs[0].zone_idx = 0;
4810 /* NUMA-aware ordering of nodes */
4811 local_node = pgdat->node_id;
4812 load = nr_online_nodes;
4813 prev_node = local_node;
4814 nodes_clear(used_mask);
4816 memset(node_order, 0, sizeof(node_order));
4819 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4821 * We don't want to pressure a particular node.
4822 * So adding penalty to the first node in same
4823 * distance group to make it round-robin.
4825 if (node_distance(local_node, node) !=
4826 node_distance(local_node, prev_node))
4827 node_load[node] = load;
4831 if (order == ZONELIST_ORDER_NODE)
4832 build_zonelists_in_node_order(pgdat, node);
4834 node_order[i++] = node; /* remember order */
4837 if (order == ZONELIST_ORDER_ZONE) {
4838 /* calculate node order -- i.e., DMA last! */
4839 build_zonelists_in_zone_order(pgdat, i);
4842 build_thisnode_zonelists(pgdat);
4845 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4847 * Return node id of node used for "local" allocations.
4848 * I.e., first node id of first zone in arg node's generic zonelist.
4849 * Used for initializing percpu 'numa_mem', which is used primarily
4850 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4852 int local_memory_node(int node)
4856 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4857 gfp_zone(GFP_KERNEL),
4859 return z->zone->node;
4863 #else /* CONFIG_NUMA */
4865 static void set_zonelist_order(void)
4867 current_zonelist_order = ZONELIST_ORDER_ZONE;
4870 static void build_zonelists(pg_data_t *pgdat)
4872 int node, local_node;
4874 struct zonelist *zonelist;
4876 local_node = pgdat->node_id;
4878 zonelist = &pgdat->node_zonelists[0];
4879 j = build_zonelists_node(pgdat, zonelist, 0);
4882 * Now we build the zonelist so that it contains the zones
4883 * of all the other nodes.
4884 * We don't want to pressure a particular node, so when
4885 * building the zones for node N, we make sure that the
4886 * zones coming right after the local ones are those from
4887 * node N+1 (modulo N)
4889 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4890 if (!node_online(node))
4892 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4894 for (node = 0; node < local_node; node++) {
4895 if (!node_online(node))
4897 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4900 zonelist->_zonerefs[j].zone = NULL;
4901 zonelist->_zonerefs[j].zone_idx = 0;
4904 #endif /* CONFIG_NUMA */
4907 * Boot pageset table. One per cpu which is going to be used for all
4908 * zones and all nodes. The parameters will be set in such a way
4909 * that an item put on a list will immediately be handed over to
4910 * the buddy list. This is safe since pageset manipulation is done
4911 * with interrupts disabled.
4913 * The boot_pagesets must be kept even after bootup is complete for
4914 * unused processors and/or zones. They do play a role for bootstrapping
4915 * hotplugged processors.
4917 * zoneinfo_show() and maybe other functions do
4918 * not check if the processor is online before following the pageset pointer.
4919 * Other parts of the kernel may not check if the zone is available.
4921 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4922 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4923 static void setup_zone_pageset(struct zone *zone);
4926 * Global mutex to protect against size modification of zonelists
4927 * as well as to serialize pageset setup for the new populated zone.
4929 DEFINE_MUTEX(zonelists_mutex);
4931 /* return values int ....just for stop_machine() */
4932 static int __build_all_zonelists(void *data)
4936 pg_data_t *self = data;
4939 memset(node_load, 0, sizeof(node_load));
4942 if (self && !node_online(self->node_id)) {
4943 build_zonelists(self);
4946 for_each_online_node(nid) {
4947 pg_data_t *pgdat = NODE_DATA(nid);
4949 build_zonelists(pgdat);
4953 * Initialize the boot_pagesets that are going to be used
4954 * for bootstrapping processors. The real pagesets for
4955 * each zone will be allocated later when the per cpu
4956 * allocator is available.
4958 * boot_pagesets are used also for bootstrapping offline
4959 * cpus if the system is already booted because the pagesets
4960 * are needed to initialize allocators on a specific cpu too.
4961 * F.e. the percpu allocator needs the page allocator which
4962 * needs the percpu allocator in order to allocate its pagesets
4963 * (a chicken-egg dilemma).
4965 for_each_possible_cpu(cpu) {
4966 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4968 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4970 * We now know the "local memory node" for each node--
4971 * i.e., the node of the first zone in the generic zonelist.
4972 * Set up numa_mem percpu variable for on-line cpus. During
4973 * boot, only the boot cpu should be on-line; we'll init the
4974 * secondary cpus' numa_mem as they come on-line. During
4975 * node/memory hotplug, we'll fixup all on-line cpus.
4977 if (cpu_online(cpu))
4978 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4985 static noinline void __init
4986 build_all_zonelists_init(void)
4988 __build_all_zonelists(NULL);
4989 mminit_verify_zonelist();
4990 cpuset_init_current_mems_allowed();
4994 * Called with zonelists_mutex held always
4995 * unless system_state == SYSTEM_BOOTING.
4997 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4998 * [we're only called with non-NULL zone through __meminit paths] and
4999 * (2) call of __init annotated helper build_all_zonelists_init
5000 * [protected by SYSTEM_BOOTING].
5002 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
5004 set_zonelist_order();
5006 if (system_state == SYSTEM_BOOTING) {
5007 build_all_zonelists_init();
5009 #ifdef CONFIG_MEMORY_HOTPLUG
5011 setup_zone_pageset(zone);
5013 /* we have to stop all cpus to guarantee there is no user
5015 stop_machine(__build_all_zonelists, pgdat, NULL);
5016 /* cpuset refresh routine should be here */
5018 vm_total_pages = nr_free_pagecache_pages();
5020 * Disable grouping by mobility if the number of pages in the
5021 * system is too low to allow the mechanism to work. It would be
5022 * more accurate, but expensive to check per-zone. This check is
5023 * made on memory-hotadd so a system can start with mobility
5024 * disabled and enable it later
5026 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5027 page_group_by_mobility_disabled = 1;
5029 page_group_by_mobility_disabled = 0;
5031 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5033 zonelist_order_name[current_zonelist_order],
5034 page_group_by_mobility_disabled ? "off" : "on",
5037 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5042 * Helper functions to size the waitqueue hash table.
5043 * Essentially these want to choose hash table sizes sufficiently
5044 * large so that collisions trying to wait on pages are rare.
5045 * But in fact, the number of active page waitqueues on typical
5046 * systems is ridiculously low, less than 200. So this is even
5047 * conservative, even though it seems large.
5049 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
5050 * waitqueues, i.e. the size of the waitq table given the number of pages.
5052 #define PAGES_PER_WAITQUEUE 256
5054 #ifndef CONFIG_MEMORY_HOTPLUG
5055 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
5057 unsigned long size = 1;
5059 pages /= PAGES_PER_WAITQUEUE;
5061 while (size < pages)
5065 * Once we have dozens or even hundreds of threads sleeping
5066 * on IO we've got bigger problems than wait queue collision.
5067 * Limit the size of the wait table to a reasonable size.
5069 size = min(size, 4096UL);
5071 return max(size, 4UL);
5075 * A zone's size might be changed by hot-add, so it is not possible to determine
5076 * a suitable size for its wait_table. So we use the maximum size now.
5078 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5080 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5081 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5082 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5084 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5085 * or more by the traditional way. (See above). It equals:
5087 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5088 * ia64(16K page size) : = ( 8G + 4M)byte.
5089 * powerpc (64K page size) : = (32G +16M)byte.
5091 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
5098 * This is an integer logarithm so that shifts can be used later
5099 * to extract the more random high bits from the multiplicative
5100 * hash function before the remainder is taken.
5102 static inline unsigned long wait_table_bits(unsigned long size)
5108 * Initially all pages are reserved - free ones are freed
5109 * up by free_all_bootmem() once the early boot process is
5110 * done. Non-atomic initialization, single-pass.
5112 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5113 unsigned long start_pfn, enum memmap_context context)
5115 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
5116 unsigned long end_pfn = start_pfn + size;
5117 pg_data_t *pgdat = NODE_DATA(nid);
5119 unsigned long nr_initialised = 0;
5120 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5121 struct memblock_region *r = NULL, *tmp;
5124 if (highest_memmap_pfn < end_pfn - 1)
5125 highest_memmap_pfn = end_pfn - 1;
5128 * Honor reservation requested by the driver for this ZONE_DEVICE
5131 if (altmap && start_pfn == altmap->base_pfn)
5132 start_pfn += altmap->reserve;
5134 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5136 * There can be holes in boot-time mem_map[]s handed to this
5137 * function. They do not exist on hotplugged memory.
5139 if (context != MEMMAP_EARLY)
5142 if (!early_pfn_valid(pfn))
5144 if (!early_pfn_in_nid(pfn, nid))
5146 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5149 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5151 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5152 * from zone_movable_pfn[nid] to end of each node should be
5153 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5155 if (!mirrored_kernelcore && zone_movable_pfn[nid])
5156 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
5160 * Check given memblock attribute by firmware which can affect
5161 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5162 * mirrored, it's an overlapped memmap init. skip it.
5164 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5165 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5166 for_each_memblock(memory, tmp)
5167 if (pfn < memblock_region_memory_end_pfn(tmp))
5171 if (pfn >= memblock_region_memory_base_pfn(r) &&
5172 memblock_is_mirror(r)) {
5173 /* already initialized as NORMAL */
5174 pfn = memblock_region_memory_end_pfn(r);
5182 * Mark the block movable so that blocks are reserved for
5183 * movable at startup. This will force kernel allocations
5184 * to reserve their blocks rather than leaking throughout
5185 * the address space during boot when many long-lived
5186 * kernel allocations are made.
5188 * bitmap is created for zone's valid pfn range. but memmap
5189 * can be created for invalid pages (for alignment)
5190 * check here not to call set_pageblock_migratetype() against
5193 if (!(pfn & (pageblock_nr_pages - 1))) {
5194 struct page *page = pfn_to_page(pfn);
5196 __init_single_page(page, pfn, zone, nid);
5197 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5199 __init_single_pfn(pfn, zone, nid);
5204 static void __meminit zone_init_free_lists(struct zone *zone)
5206 unsigned int order, t;
5207 for_each_migratetype_order(order, t) {
5208 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5209 zone->free_area[order].nr_free = 0;
5213 #ifndef __HAVE_ARCH_MEMMAP_INIT
5214 #define memmap_init(size, nid, zone, start_pfn) \
5215 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5218 static int zone_batchsize(struct zone *zone)
5224 * The per-cpu-pages pools are set to around 1000th of the
5225 * size of the zone. But no more than 1/2 of a meg.
5227 * OK, so we don't know how big the cache is. So guess.
5229 batch = zone->managed_pages / 1024;
5230 if (batch * PAGE_SIZE > 512 * 1024)
5231 batch = (512 * 1024) / PAGE_SIZE;
5232 batch /= 4; /* We effectively *= 4 below */
5237 * Clamp the batch to a 2^n - 1 value. Having a power
5238 * of 2 value was found to be more likely to have
5239 * suboptimal cache aliasing properties in some cases.
5241 * For example if 2 tasks are alternately allocating
5242 * batches of pages, one task can end up with a lot
5243 * of pages of one half of the possible page colors
5244 * and the other with pages of the other colors.
5246 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5251 /* The deferral and batching of frees should be suppressed under NOMMU
5254 * The problem is that NOMMU needs to be able to allocate large chunks
5255 * of contiguous memory as there's no hardware page translation to
5256 * assemble apparent contiguous memory from discontiguous pages.
5258 * Queueing large contiguous runs of pages for batching, however,
5259 * causes the pages to actually be freed in smaller chunks. As there
5260 * can be a significant delay between the individual batches being
5261 * recycled, this leads to the once large chunks of space being
5262 * fragmented and becoming unavailable for high-order allocations.
5269 * pcp->high and pcp->batch values are related and dependent on one another:
5270 * ->batch must never be higher then ->high.
5271 * The following function updates them in a safe manner without read side
5274 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5275 * those fields changing asynchronously (acording the the above rule).
5277 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5278 * outside of boot time (or some other assurance that no concurrent updaters
5281 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5282 unsigned long batch)
5284 /* start with a fail safe value for batch */
5288 /* Update high, then batch, in order */
5295 /* a companion to pageset_set_high() */
5296 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5298 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5301 static void pageset_init(struct per_cpu_pageset *p)
5303 struct per_cpu_pages *pcp;
5306 memset(p, 0, sizeof(*p));
5310 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5311 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5314 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5317 pageset_set_batch(p, batch);
5321 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5322 * to the value high for the pageset p.
5324 static void pageset_set_high(struct per_cpu_pageset *p,
5327 unsigned long batch = max(1UL, high / 4);
5328 if ((high / 4) > (PAGE_SHIFT * 8))
5329 batch = PAGE_SHIFT * 8;
5331 pageset_update(&p->pcp, high, batch);
5334 static void pageset_set_high_and_batch(struct zone *zone,
5335 struct per_cpu_pageset *pcp)
5337 if (percpu_pagelist_fraction)
5338 pageset_set_high(pcp,
5339 (zone->managed_pages /
5340 percpu_pagelist_fraction));
5342 pageset_set_batch(pcp, zone_batchsize(zone));
5345 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5347 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5350 pageset_set_high_and_batch(zone, pcp);
5353 static void __meminit setup_zone_pageset(struct zone *zone)
5356 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5357 for_each_possible_cpu(cpu)
5358 zone_pageset_init(zone, cpu);
5362 * Allocate per cpu pagesets and initialize them.
5363 * Before this call only boot pagesets were available.
5365 void __init setup_per_cpu_pageset(void)
5369 for_each_populated_zone(zone)
5370 setup_zone_pageset(zone);
5373 static noinline __init_refok
5374 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
5380 * The per-page waitqueue mechanism uses hashed waitqueues
5383 zone->wait_table_hash_nr_entries =
5384 wait_table_hash_nr_entries(zone_size_pages);
5385 zone->wait_table_bits =
5386 wait_table_bits(zone->wait_table_hash_nr_entries);
5387 alloc_size = zone->wait_table_hash_nr_entries
5388 * sizeof(wait_queue_head_t);
5390 if (!slab_is_available()) {
5391 zone->wait_table = (wait_queue_head_t *)
5392 memblock_virt_alloc_node_nopanic(
5393 alloc_size, zone->zone_pgdat->node_id);
5396 * This case means that a zone whose size was 0 gets new memory
5397 * via memory hot-add.
5398 * But it may be the case that a new node was hot-added. In
5399 * this case vmalloc() will not be able to use this new node's
5400 * memory - this wait_table must be initialized to use this new
5401 * node itself as well.
5402 * To use this new node's memory, further consideration will be
5405 zone->wait_table = vmalloc(alloc_size);
5407 if (!zone->wait_table)
5410 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
5411 init_waitqueue_head(zone->wait_table + i);
5416 static __meminit void zone_pcp_init(struct zone *zone)
5419 * per cpu subsystem is not up at this point. The following code
5420 * relies on the ability of the linker to provide the
5421 * offset of a (static) per cpu variable into the per cpu area.
5423 zone->pageset = &boot_pageset;
5425 if (populated_zone(zone))
5426 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5427 zone->name, zone->present_pages,
5428 zone_batchsize(zone));
5431 int __meminit init_currently_empty_zone(struct zone *zone,
5432 unsigned long zone_start_pfn,
5435 struct pglist_data *pgdat = zone->zone_pgdat;
5437 ret = zone_wait_table_init(zone, size);
5440 pgdat->nr_zones = zone_idx(zone) + 1;
5442 zone->zone_start_pfn = zone_start_pfn;
5444 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5445 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5447 (unsigned long)zone_idx(zone),
5448 zone_start_pfn, (zone_start_pfn + size));
5450 zone_init_free_lists(zone);
5455 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5456 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5459 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5461 int __meminit __early_pfn_to_nid(unsigned long pfn,
5462 struct mminit_pfnnid_cache *state)
5464 unsigned long start_pfn, end_pfn;
5467 if (state->last_start <= pfn && pfn < state->last_end)
5468 return state->last_nid;
5470 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5472 state->last_start = start_pfn;
5473 state->last_end = end_pfn;
5474 state->last_nid = nid;
5479 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5482 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5483 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5484 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5486 * If an architecture guarantees that all ranges registered contain no holes
5487 * and may be freed, this this function may be used instead of calling
5488 * memblock_free_early_nid() manually.
5490 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5492 unsigned long start_pfn, end_pfn;
5495 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5496 start_pfn = min(start_pfn, max_low_pfn);
5497 end_pfn = min(end_pfn, max_low_pfn);
5499 if (start_pfn < end_pfn)
5500 memblock_free_early_nid(PFN_PHYS(start_pfn),
5501 (end_pfn - start_pfn) << PAGE_SHIFT,
5507 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5508 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5510 * If an architecture guarantees that all ranges registered contain no holes and may
5511 * be freed, this function may be used instead of calling memory_present() manually.
5513 void __init sparse_memory_present_with_active_regions(int nid)
5515 unsigned long start_pfn, end_pfn;
5518 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5519 memory_present(this_nid, start_pfn, end_pfn);
5523 * get_pfn_range_for_nid - Return the start and end page frames for a node
5524 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5525 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5526 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5528 * It returns the start and end page frame of a node based on information
5529 * provided by memblock_set_node(). If called for a node
5530 * with no available memory, a warning is printed and the start and end
5533 void __meminit get_pfn_range_for_nid(unsigned int nid,
5534 unsigned long *start_pfn, unsigned long *end_pfn)
5536 unsigned long this_start_pfn, this_end_pfn;
5542 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5543 *start_pfn = min(*start_pfn, this_start_pfn);
5544 *end_pfn = max(*end_pfn, this_end_pfn);
5547 if (*start_pfn == -1UL)
5552 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5553 * assumption is made that zones within a node are ordered in monotonic
5554 * increasing memory addresses so that the "highest" populated zone is used
5556 static void __init find_usable_zone_for_movable(void)
5559 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5560 if (zone_index == ZONE_MOVABLE)
5563 if (arch_zone_highest_possible_pfn[zone_index] >
5564 arch_zone_lowest_possible_pfn[zone_index])
5568 VM_BUG_ON(zone_index == -1);
5569 movable_zone = zone_index;
5573 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5574 * because it is sized independent of architecture. Unlike the other zones,
5575 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5576 * in each node depending on the size of each node and how evenly kernelcore
5577 * is distributed. This helper function adjusts the zone ranges
5578 * provided by the architecture for a given node by using the end of the
5579 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5580 * zones within a node are in order of monotonic increases memory addresses
5582 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5583 unsigned long zone_type,
5584 unsigned long node_start_pfn,
5585 unsigned long node_end_pfn,
5586 unsigned long *zone_start_pfn,
5587 unsigned long *zone_end_pfn)
5589 /* Only adjust if ZONE_MOVABLE is on this node */
5590 if (zone_movable_pfn[nid]) {
5591 /* Size ZONE_MOVABLE */
5592 if (zone_type == ZONE_MOVABLE) {
5593 *zone_start_pfn = zone_movable_pfn[nid];
5594 *zone_end_pfn = min(node_end_pfn,
5595 arch_zone_highest_possible_pfn[movable_zone]);
5597 /* Check if this whole range is within ZONE_MOVABLE */
5598 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5599 *zone_start_pfn = *zone_end_pfn;
5604 * Return the number of pages a zone spans in a node, including holes
5605 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5607 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5608 unsigned long zone_type,
5609 unsigned long node_start_pfn,
5610 unsigned long node_end_pfn,
5611 unsigned long *zone_start_pfn,
5612 unsigned long *zone_end_pfn,
5613 unsigned long *ignored)
5615 /* When hotadd a new node from cpu_up(), the node should be empty */
5616 if (!node_start_pfn && !node_end_pfn)
5619 /* Get the start and end of the zone */
5620 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5621 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5622 adjust_zone_range_for_zone_movable(nid, zone_type,
5623 node_start_pfn, node_end_pfn,
5624 zone_start_pfn, zone_end_pfn);
5626 /* Check that this node has pages within the zone's required range */
5627 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5630 /* Move the zone boundaries inside the node if necessary */
5631 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5632 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5634 /* Return the spanned pages */
5635 return *zone_end_pfn - *zone_start_pfn;
5639 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5640 * then all holes in the requested range will be accounted for.
5642 unsigned long __meminit __absent_pages_in_range(int nid,
5643 unsigned long range_start_pfn,
5644 unsigned long range_end_pfn)
5646 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5647 unsigned long start_pfn, end_pfn;
5650 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5651 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5652 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5653 nr_absent -= end_pfn - start_pfn;
5659 * absent_pages_in_range - Return number of page frames in holes within a range
5660 * @start_pfn: The start PFN to start searching for holes
5661 * @end_pfn: The end PFN to stop searching for holes
5663 * It returns the number of pages frames in memory holes within a range.
5665 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5666 unsigned long end_pfn)
5668 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5671 /* Return the number of page frames in holes in a zone on a node */
5672 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5673 unsigned long zone_type,
5674 unsigned long node_start_pfn,
5675 unsigned long node_end_pfn,
5676 unsigned long *ignored)
5678 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5679 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5680 unsigned long zone_start_pfn, zone_end_pfn;
5681 unsigned long nr_absent;
5683 /* When hotadd a new node from cpu_up(), the node should be empty */
5684 if (!node_start_pfn && !node_end_pfn)
5687 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5688 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5690 adjust_zone_range_for_zone_movable(nid, zone_type,
5691 node_start_pfn, node_end_pfn,
5692 &zone_start_pfn, &zone_end_pfn);
5693 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5696 * ZONE_MOVABLE handling.
5697 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5700 if (zone_movable_pfn[nid]) {
5701 if (mirrored_kernelcore) {
5702 unsigned long start_pfn, end_pfn;
5703 struct memblock_region *r;
5705 for_each_memblock(memory, r) {
5706 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5707 zone_start_pfn, zone_end_pfn);
5708 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5709 zone_start_pfn, zone_end_pfn);
5711 if (zone_type == ZONE_MOVABLE &&
5712 memblock_is_mirror(r))
5713 nr_absent += end_pfn - start_pfn;
5715 if (zone_type == ZONE_NORMAL &&
5716 !memblock_is_mirror(r))
5717 nr_absent += end_pfn - start_pfn;
5720 if (zone_type == ZONE_NORMAL)
5721 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5728 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5729 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5730 unsigned long zone_type,
5731 unsigned long node_start_pfn,
5732 unsigned long node_end_pfn,
5733 unsigned long *zone_start_pfn,
5734 unsigned long *zone_end_pfn,
5735 unsigned long *zones_size)
5739 *zone_start_pfn = node_start_pfn;
5740 for (zone = 0; zone < zone_type; zone++)
5741 *zone_start_pfn += zones_size[zone];
5743 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5745 return zones_size[zone_type];
5748 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5749 unsigned long zone_type,
5750 unsigned long node_start_pfn,
5751 unsigned long node_end_pfn,
5752 unsigned long *zholes_size)
5757 return zholes_size[zone_type];
5760 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5762 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5763 unsigned long node_start_pfn,
5764 unsigned long node_end_pfn,
5765 unsigned long *zones_size,
5766 unsigned long *zholes_size)
5768 unsigned long realtotalpages = 0, totalpages = 0;
5771 for (i = 0; i < MAX_NR_ZONES; i++) {
5772 struct zone *zone = pgdat->node_zones + i;
5773 unsigned long zone_start_pfn, zone_end_pfn;
5774 unsigned long size, real_size;
5776 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5782 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5783 node_start_pfn, node_end_pfn,
5786 zone->zone_start_pfn = zone_start_pfn;
5788 zone->zone_start_pfn = 0;
5789 zone->spanned_pages = size;
5790 zone->present_pages = real_size;
5793 realtotalpages += real_size;
5796 pgdat->node_spanned_pages = totalpages;
5797 pgdat->node_present_pages = realtotalpages;
5798 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5802 #ifndef CONFIG_SPARSEMEM
5804 * Calculate the size of the zone->blockflags rounded to an unsigned long
5805 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5806 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5807 * round what is now in bits to nearest long in bits, then return it in
5810 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5812 unsigned long usemapsize;
5814 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5815 usemapsize = roundup(zonesize, pageblock_nr_pages);
5816 usemapsize = usemapsize >> pageblock_order;
5817 usemapsize *= NR_PAGEBLOCK_BITS;
5818 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5820 return usemapsize / 8;
5823 static void __init setup_usemap(struct pglist_data *pgdat,
5825 unsigned long zone_start_pfn,
5826 unsigned long zonesize)
5828 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5829 zone->pageblock_flags = NULL;
5831 zone->pageblock_flags =
5832 memblock_virt_alloc_node_nopanic(usemapsize,
5836 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5837 unsigned long zone_start_pfn, unsigned long zonesize) {}
5838 #endif /* CONFIG_SPARSEMEM */
5840 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5842 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5843 void __paginginit set_pageblock_order(void)
5847 /* Check that pageblock_nr_pages has not already been setup */
5848 if (pageblock_order)
5851 if (HPAGE_SHIFT > PAGE_SHIFT)
5852 order = HUGETLB_PAGE_ORDER;
5854 order = MAX_ORDER - 1;
5857 * Assume the largest contiguous order of interest is a huge page.
5858 * This value may be variable depending on boot parameters on IA64 and
5861 pageblock_order = order;
5863 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5866 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5867 * is unused as pageblock_order is set at compile-time. See
5868 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5871 void __paginginit set_pageblock_order(void)
5875 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5877 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5878 unsigned long present_pages)
5880 unsigned long pages = spanned_pages;
5883 * Provide a more accurate estimation if there are holes within
5884 * the zone and SPARSEMEM is in use. If there are holes within the
5885 * zone, each populated memory region may cost us one or two extra
5886 * memmap pages due to alignment because memmap pages for each
5887 * populated regions may not naturally algined on page boundary.
5888 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5890 if (spanned_pages > present_pages + (present_pages >> 4) &&
5891 IS_ENABLED(CONFIG_SPARSEMEM))
5892 pages = present_pages;
5894 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5898 * Set up the zone data structures:
5899 * - mark all pages reserved
5900 * - mark all memory queues empty
5901 * - clear the memory bitmaps
5903 * NOTE: pgdat should get zeroed by caller.
5905 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5908 int nid = pgdat->node_id;
5911 pgdat_resize_init(pgdat);
5912 #ifdef CONFIG_NUMA_BALANCING
5913 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5914 pgdat->numabalancing_migrate_nr_pages = 0;
5915 pgdat->numabalancing_migrate_next_window = jiffies;
5917 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5918 spin_lock_init(&pgdat->split_queue_lock);
5919 INIT_LIST_HEAD(&pgdat->split_queue);
5920 pgdat->split_queue_len = 0;
5922 init_waitqueue_head(&pgdat->kswapd_wait);
5923 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5924 #ifdef CONFIG_COMPACTION
5925 init_waitqueue_head(&pgdat->kcompactd_wait);
5927 pgdat_page_ext_init(pgdat);
5929 for (j = 0; j < MAX_NR_ZONES; j++) {
5930 struct zone *zone = pgdat->node_zones + j;
5931 unsigned long size, realsize, freesize, memmap_pages;
5932 unsigned long zone_start_pfn = zone->zone_start_pfn;
5934 size = zone->spanned_pages;
5935 realsize = freesize = zone->present_pages;
5938 * Adjust freesize so that it accounts for how much memory
5939 * is used by this zone for memmap. This affects the watermark
5940 * and per-cpu initialisations
5942 memmap_pages = calc_memmap_size(size, realsize);
5943 if (!is_highmem_idx(j)) {
5944 if (freesize >= memmap_pages) {
5945 freesize -= memmap_pages;
5948 " %s zone: %lu pages used for memmap\n",
5949 zone_names[j], memmap_pages);
5951 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5952 zone_names[j], memmap_pages, freesize);
5955 /* Account for reserved pages */
5956 if (j == 0 && freesize > dma_reserve) {
5957 freesize -= dma_reserve;
5958 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5959 zone_names[0], dma_reserve);
5962 if (!is_highmem_idx(j))
5963 nr_kernel_pages += freesize;
5964 /* Charge for highmem memmap if there are enough kernel pages */
5965 else if (nr_kernel_pages > memmap_pages * 2)
5966 nr_kernel_pages -= memmap_pages;
5967 nr_all_pages += freesize;
5970 * Set an approximate value for lowmem here, it will be adjusted
5971 * when the bootmem allocator frees pages into the buddy system.
5972 * And all highmem pages will be managed by the buddy system.
5974 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5977 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5979 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5981 zone->name = zone_names[j];
5982 spin_lock_init(&zone->lock);
5983 spin_lock_init(&zone->lru_lock);
5984 zone_seqlock_init(zone);
5985 zone->zone_pgdat = pgdat;
5986 zone_pcp_init(zone);
5988 /* For bootup, initialized properly in watermark setup */
5989 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5991 lruvec_init(&zone->lruvec);
5995 set_pageblock_order();
5996 setup_usemap(pgdat, zone, zone_start_pfn, size);
5997 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5999 memmap_init(size, nid, j, zone_start_pfn);
6003 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
6005 unsigned long __maybe_unused start = 0;
6006 unsigned long __maybe_unused offset = 0;
6008 /* Skip empty nodes */
6009 if (!pgdat->node_spanned_pages)
6012 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6013 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6014 offset = pgdat->node_start_pfn - start;
6015 /* ia64 gets its own node_mem_map, before this, without bootmem */
6016 if (!pgdat->node_mem_map) {
6017 unsigned long size, end;
6021 * The zone's endpoints aren't required to be MAX_ORDER
6022 * aligned but the node_mem_map endpoints must be in order
6023 * for the buddy allocator to function correctly.
6025 end = pgdat_end_pfn(pgdat);
6026 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6027 size = (end - start) * sizeof(struct page);
6028 map = alloc_remap(pgdat->node_id, size);
6030 map = memblock_virt_alloc_node_nopanic(size,
6032 pgdat->node_mem_map = map + offset;
6034 #ifndef CONFIG_NEED_MULTIPLE_NODES
6036 * With no DISCONTIG, the global mem_map is just set as node 0's
6038 if (pgdat == NODE_DATA(0)) {
6039 mem_map = NODE_DATA(0)->node_mem_map;
6040 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6041 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6043 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6046 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6049 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
6050 unsigned long node_start_pfn, unsigned long *zholes_size)
6052 pg_data_t *pgdat = NODE_DATA(nid);
6053 unsigned long start_pfn = 0;
6054 unsigned long end_pfn = 0;
6056 /* pg_data_t should be reset to zero when it's allocated */
6057 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
6059 reset_deferred_meminit(pgdat);
6060 pgdat->node_id = nid;
6061 pgdat->node_start_pfn = node_start_pfn;
6062 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6063 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6064 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6065 (u64)start_pfn << PAGE_SHIFT,
6066 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6068 start_pfn = node_start_pfn;
6070 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6071 zones_size, zholes_size);
6073 alloc_node_mem_map(pgdat);
6074 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6075 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6076 nid, (unsigned long)pgdat,
6077 (unsigned long)pgdat->node_mem_map);
6080 free_area_init_core(pgdat);
6083 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6085 #if MAX_NUMNODES > 1
6087 * Figure out the number of possible node ids.
6089 void __init setup_nr_node_ids(void)
6091 unsigned int highest;
6093 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
6094 nr_node_ids = highest + 1;
6099 * node_map_pfn_alignment - determine the maximum internode alignment
6101 * This function should be called after node map is populated and sorted.
6102 * It calculates the maximum power of two alignment which can distinguish
6105 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6106 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6107 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6108 * shifted, 1GiB is enough and this function will indicate so.
6110 * This is used to test whether pfn -> nid mapping of the chosen memory
6111 * model has fine enough granularity to avoid incorrect mapping for the
6112 * populated node map.
6114 * Returns the determined alignment in pfn's. 0 if there is no alignment
6115 * requirement (single node).
6117 unsigned long __init node_map_pfn_alignment(void)
6119 unsigned long accl_mask = 0, last_end = 0;
6120 unsigned long start, end, mask;
6124 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
6125 if (!start || last_nid < 0 || last_nid == nid) {
6132 * Start with a mask granular enough to pin-point to the
6133 * start pfn and tick off bits one-by-one until it becomes
6134 * too coarse to separate the current node from the last.
6136 mask = ~((1 << __ffs(start)) - 1);
6137 while (mask && last_end <= (start & (mask << 1)))
6140 /* accumulate all internode masks */
6144 /* convert mask to number of pages */
6145 return ~accl_mask + 1;
6148 /* Find the lowest pfn for a node */
6149 static unsigned long __init find_min_pfn_for_node(int nid)
6151 unsigned long min_pfn = ULONG_MAX;
6152 unsigned long start_pfn;
6155 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
6156 min_pfn = min(min_pfn, start_pfn);
6158 if (min_pfn == ULONG_MAX) {
6159 pr_warn("Could not find start_pfn for node %d\n", nid);
6167 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6169 * It returns the minimum PFN based on information provided via
6170 * memblock_set_node().
6172 unsigned long __init find_min_pfn_with_active_regions(void)
6174 return find_min_pfn_for_node(MAX_NUMNODES);
6178 * early_calculate_totalpages()
6179 * Sum pages in active regions for movable zone.
6180 * Populate N_MEMORY for calculating usable_nodes.
6182 static unsigned long __init early_calculate_totalpages(void)
6184 unsigned long totalpages = 0;
6185 unsigned long start_pfn, end_pfn;
6188 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6189 unsigned long pages = end_pfn - start_pfn;
6191 totalpages += pages;
6193 node_set_state(nid, N_MEMORY);
6199 * Find the PFN the Movable zone begins in each node. Kernel memory
6200 * is spread evenly between nodes as long as the nodes have enough
6201 * memory. When they don't, some nodes will have more kernelcore than
6204 static void __init find_zone_movable_pfns_for_nodes(void)
6207 unsigned long usable_startpfn;
6208 unsigned long kernelcore_node, kernelcore_remaining;
6209 /* save the state before borrow the nodemask */
6210 nodemask_t saved_node_state = node_states[N_MEMORY];
6211 unsigned long totalpages = early_calculate_totalpages();
6212 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6213 struct memblock_region *r;
6215 /* Need to find movable_zone earlier when movable_node is specified. */
6216 find_usable_zone_for_movable();
6219 * If movable_node is specified, ignore kernelcore and movablecore
6222 if (movable_node_is_enabled()) {
6223 for_each_memblock(memory, r) {
6224 if (!memblock_is_hotpluggable(r))
6229 usable_startpfn = PFN_DOWN(r->base);
6230 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6231 min(usable_startpfn, zone_movable_pfn[nid]) :
6239 * If kernelcore=mirror is specified, ignore movablecore option
6241 if (mirrored_kernelcore) {
6242 bool mem_below_4gb_not_mirrored = false;
6244 for_each_memblock(memory, r) {
6245 if (memblock_is_mirror(r))
6250 usable_startpfn = memblock_region_memory_base_pfn(r);
6252 if (usable_startpfn < 0x100000) {
6253 mem_below_4gb_not_mirrored = true;
6257 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6258 min(usable_startpfn, zone_movable_pfn[nid]) :
6262 if (mem_below_4gb_not_mirrored)
6263 pr_warn("This configuration results in unmirrored kernel memory.");
6269 * If movablecore=nn[KMG] was specified, calculate what size of
6270 * kernelcore that corresponds so that memory usable for
6271 * any allocation type is evenly spread. If both kernelcore
6272 * and movablecore are specified, then the value of kernelcore
6273 * will be used for required_kernelcore if it's greater than
6274 * what movablecore would have allowed.
6276 if (required_movablecore) {
6277 unsigned long corepages;
6280 * Round-up so that ZONE_MOVABLE is at least as large as what
6281 * was requested by the user
6283 required_movablecore =
6284 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6285 required_movablecore = min(totalpages, required_movablecore);
6286 corepages = totalpages - required_movablecore;
6288 required_kernelcore = max(required_kernelcore, corepages);
6292 * If kernelcore was not specified or kernelcore size is larger
6293 * than totalpages, there is no ZONE_MOVABLE.
6295 if (!required_kernelcore || required_kernelcore >= totalpages)
6298 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6299 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6302 /* Spread kernelcore memory as evenly as possible throughout nodes */
6303 kernelcore_node = required_kernelcore / usable_nodes;
6304 for_each_node_state(nid, N_MEMORY) {
6305 unsigned long start_pfn, end_pfn;
6308 * Recalculate kernelcore_node if the division per node
6309 * now exceeds what is necessary to satisfy the requested
6310 * amount of memory for the kernel
6312 if (required_kernelcore < kernelcore_node)
6313 kernelcore_node = required_kernelcore / usable_nodes;
6316 * As the map is walked, we track how much memory is usable
6317 * by the kernel using kernelcore_remaining. When it is
6318 * 0, the rest of the node is usable by ZONE_MOVABLE
6320 kernelcore_remaining = kernelcore_node;
6322 /* Go through each range of PFNs within this node */
6323 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6324 unsigned long size_pages;
6326 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6327 if (start_pfn >= end_pfn)
6330 /* Account for what is only usable for kernelcore */
6331 if (start_pfn < usable_startpfn) {
6332 unsigned long kernel_pages;
6333 kernel_pages = min(end_pfn, usable_startpfn)
6336 kernelcore_remaining -= min(kernel_pages,
6337 kernelcore_remaining);
6338 required_kernelcore -= min(kernel_pages,
6339 required_kernelcore);
6341 /* Continue if range is now fully accounted */
6342 if (end_pfn <= usable_startpfn) {
6345 * Push zone_movable_pfn to the end so
6346 * that if we have to rebalance
6347 * kernelcore across nodes, we will
6348 * not double account here
6350 zone_movable_pfn[nid] = end_pfn;
6353 start_pfn = usable_startpfn;
6357 * The usable PFN range for ZONE_MOVABLE is from
6358 * start_pfn->end_pfn. Calculate size_pages as the
6359 * number of pages used as kernelcore
6361 size_pages = end_pfn - start_pfn;
6362 if (size_pages > kernelcore_remaining)
6363 size_pages = kernelcore_remaining;
6364 zone_movable_pfn[nid] = start_pfn + size_pages;
6367 * Some kernelcore has been met, update counts and
6368 * break if the kernelcore for this node has been
6371 required_kernelcore -= min(required_kernelcore,
6373 kernelcore_remaining -= size_pages;
6374 if (!kernelcore_remaining)
6380 * If there is still required_kernelcore, we do another pass with one
6381 * less node in the count. This will push zone_movable_pfn[nid] further
6382 * along on the nodes that still have memory until kernelcore is
6386 if (usable_nodes && required_kernelcore > usable_nodes)
6390 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6391 for (nid = 0; nid < MAX_NUMNODES; nid++)
6392 zone_movable_pfn[nid] =
6393 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6396 /* restore the node_state */
6397 node_states[N_MEMORY] = saved_node_state;
6400 /* Any regular or high memory on that node ? */
6401 static void check_for_memory(pg_data_t *pgdat, int nid)
6403 enum zone_type zone_type;
6405 if (N_MEMORY == N_NORMAL_MEMORY)
6408 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6409 struct zone *zone = &pgdat->node_zones[zone_type];
6410 if (populated_zone(zone)) {
6411 node_set_state(nid, N_HIGH_MEMORY);
6412 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6413 zone_type <= ZONE_NORMAL)
6414 node_set_state(nid, N_NORMAL_MEMORY);
6421 * free_area_init_nodes - Initialise all pg_data_t and zone data
6422 * @max_zone_pfn: an array of max PFNs for each zone
6424 * This will call free_area_init_node() for each active node in the system.
6425 * Using the page ranges provided by memblock_set_node(), the size of each
6426 * zone in each node and their holes is calculated. If the maximum PFN
6427 * between two adjacent zones match, it is assumed that the zone is empty.
6428 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6429 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6430 * starts where the previous one ended. For example, ZONE_DMA32 starts
6431 * at arch_max_dma_pfn.
6433 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6435 unsigned long start_pfn, end_pfn;
6438 /* Record where the zone boundaries are */
6439 memset(arch_zone_lowest_possible_pfn, 0,
6440 sizeof(arch_zone_lowest_possible_pfn));
6441 memset(arch_zone_highest_possible_pfn, 0,
6442 sizeof(arch_zone_highest_possible_pfn));
6443 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
6444 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
6445 for (i = 1; i < MAX_NR_ZONES; i++) {
6446 if (i == ZONE_MOVABLE)
6448 arch_zone_lowest_possible_pfn[i] =
6449 arch_zone_highest_possible_pfn[i-1];
6450 arch_zone_highest_possible_pfn[i] =
6451 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
6453 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6454 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6456 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6457 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6458 find_zone_movable_pfns_for_nodes();
6460 /* Print out the zone ranges */
6461 pr_info("Zone ranges:\n");
6462 for (i = 0; i < MAX_NR_ZONES; i++) {
6463 if (i == ZONE_MOVABLE)
6465 pr_info(" %-8s ", zone_names[i]);
6466 if (arch_zone_lowest_possible_pfn[i] ==
6467 arch_zone_highest_possible_pfn[i])
6470 pr_cont("[mem %#018Lx-%#018Lx]\n",
6471 (u64)arch_zone_lowest_possible_pfn[i]
6473 ((u64)arch_zone_highest_possible_pfn[i]
6474 << PAGE_SHIFT) - 1);
6477 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6478 pr_info("Movable zone start for each node\n");
6479 for (i = 0; i < MAX_NUMNODES; i++) {
6480 if (zone_movable_pfn[i])
6481 pr_info(" Node %d: %#018Lx\n", i,
6482 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6485 /* Print out the early node map */
6486 pr_info("Early memory node ranges\n");
6487 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6488 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6489 (u64)start_pfn << PAGE_SHIFT,
6490 ((u64)end_pfn << PAGE_SHIFT) - 1);
6492 /* Initialise every node */
6493 mminit_verify_pageflags_layout();
6494 setup_nr_node_ids();
6495 for_each_online_node(nid) {
6496 pg_data_t *pgdat = NODE_DATA(nid);
6497 free_area_init_node(nid, NULL,
6498 find_min_pfn_for_node(nid), NULL);
6500 /* Any memory on that node */
6501 if (pgdat->node_present_pages)
6502 node_set_state(nid, N_MEMORY);
6503 check_for_memory(pgdat, nid);
6507 static int __init cmdline_parse_core(char *p, unsigned long *core)
6509 unsigned long long coremem;
6513 coremem = memparse(p, &p);
6514 *core = coremem >> PAGE_SHIFT;
6516 /* Paranoid check that UL is enough for the coremem value */
6517 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6523 * kernelcore=size sets the amount of memory for use for allocations that
6524 * cannot be reclaimed or migrated.
6526 static int __init cmdline_parse_kernelcore(char *p)
6528 /* parse kernelcore=mirror */
6529 if (parse_option_str(p, "mirror")) {
6530 mirrored_kernelcore = true;
6534 return cmdline_parse_core(p, &required_kernelcore);
6538 * movablecore=size sets the amount of memory for use for allocations that
6539 * can be reclaimed or migrated.
6541 static int __init cmdline_parse_movablecore(char *p)
6543 return cmdline_parse_core(p, &required_movablecore);
6546 early_param("kernelcore", cmdline_parse_kernelcore);
6547 early_param("movablecore", cmdline_parse_movablecore);
6549 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6551 void adjust_managed_page_count(struct page *page, long count)
6553 spin_lock(&managed_page_count_lock);
6554 page_zone(page)->managed_pages += count;
6555 totalram_pages += count;
6556 #ifdef CONFIG_HIGHMEM
6557 if (PageHighMem(page))
6558 totalhigh_pages += count;
6560 spin_unlock(&managed_page_count_lock);
6562 EXPORT_SYMBOL(adjust_managed_page_count);
6564 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6567 unsigned long pages = 0;
6569 start = (void *)PAGE_ALIGN((unsigned long)start);
6570 end = (void *)((unsigned long)end & PAGE_MASK);
6571 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6572 if ((unsigned int)poison <= 0xFF)
6573 memset(pos, poison, PAGE_SIZE);
6574 free_reserved_page(virt_to_page(pos));
6578 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6579 s, pages << (PAGE_SHIFT - 10), start, end);
6583 EXPORT_SYMBOL(free_reserved_area);
6585 #ifdef CONFIG_HIGHMEM
6586 void free_highmem_page(struct page *page)
6588 __free_reserved_page(page);
6590 page_zone(page)->managed_pages++;
6596 void __init mem_init_print_info(const char *str)
6598 unsigned long physpages, codesize, datasize, rosize, bss_size;
6599 unsigned long init_code_size, init_data_size;
6601 physpages = get_num_physpages();
6602 codesize = _etext - _stext;
6603 datasize = _edata - _sdata;
6604 rosize = __end_rodata - __start_rodata;
6605 bss_size = __bss_stop - __bss_start;
6606 init_data_size = __init_end - __init_begin;
6607 init_code_size = _einittext - _sinittext;
6610 * Detect special cases and adjust section sizes accordingly:
6611 * 1) .init.* may be embedded into .data sections
6612 * 2) .init.text.* may be out of [__init_begin, __init_end],
6613 * please refer to arch/tile/kernel/vmlinux.lds.S.
6614 * 3) .rodata.* may be embedded into .text or .data sections.
6616 #define adj_init_size(start, end, size, pos, adj) \
6618 if (start <= pos && pos < end && size > adj) \
6622 adj_init_size(__init_begin, __init_end, init_data_size,
6623 _sinittext, init_code_size);
6624 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6625 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6626 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6627 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6629 #undef adj_init_size
6631 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6632 #ifdef CONFIG_HIGHMEM
6636 nr_free_pages() << (PAGE_SHIFT - 10),
6637 physpages << (PAGE_SHIFT - 10),
6638 codesize >> 10, datasize >> 10, rosize >> 10,
6639 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6640 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6641 totalcma_pages << (PAGE_SHIFT - 10),
6642 #ifdef CONFIG_HIGHMEM
6643 totalhigh_pages << (PAGE_SHIFT - 10),
6645 str ? ", " : "", str ? str : "");
6649 * set_dma_reserve - set the specified number of pages reserved in the first zone
6650 * @new_dma_reserve: The number of pages to mark reserved
6652 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6653 * In the DMA zone, a significant percentage may be consumed by kernel image
6654 * and other unfreeable allocations which can skew the watermarks badly. This
6655 * function may optionally be used to account for unfreeable pages in the
6656 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6657 * smaller per-cpu batchsize.
6659 void __init set_dma_reserve(unsigned long new_dma_reserve)
6661 dma_reserve = new_dma_reserve;
6664 void __init free_area_init(unsigned long *zones_size)
6666 free_area_init_node(0, zones_size,
6667 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6670 static int page_alloc_cpu_notify(struct notifier_block *self,
6671 unsigned long action, void *hcpu)
6673 int cpu = (unsigned long)hcpu;
6675 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6676 lru_add_drain_cpu(cpu);
6680 * Spill the event counters of the dead processor
6681 * into the current processors event counters.
6682 * This artificially elevates the count of the current
6685 vm_events_fold_cpu(cpu);
6688 * Zero the differential counters of the dead processor
6689 * so that the vm statistics are consistent.
6691 * This is only okay since the processor is dead and cannot
6692 * race with what we are doing.
6694 cpu_vm_stats_fold(cpu);
6699 void __init page_alloc_init(void)
6701 hotcpu_notifier(page_alloc_cpu_notify, 0);
6705 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6706 * or min_free_kbytes changes.
6708 static void calculate_totalreserve_pages(void)
6710 struct pglist_data *pgdat;
6711 unsigned long reserve_pages = 0;
6712 enum zone_type i, j;
6714 for_each_online_pgdat(pgdat) {
6715 for (i = 0; i < MAX_NR_ZONES; i++) {
6716 struct zone *zone = pgdat->node_zones + i;
6719 /* Find valid and maximum lowmem_reserve in the zone */
6720 for (j = i; j < MAX_NR_ZONES; j++) {
6721 if (zone->lowmem_reserve[j] > max)
6722 max = zone->lowmem_reserve[j];
6725 /* we treat the high watermark as reserved pages. */
6726 max += high_wmark_pages(zone);
6728 if (max > zone->managed_pages)
6729 max = zone->managed_pages;
6731 zone->totalreserve_pages = max;
6733 reserve_pages += max;
6736 totalreserve_pages = reserve_pages;
6740 * setup_per_zone_lowmem_reserve - called whenever
6741 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6742 * has a correct pages reserved value, so an adequate number of
6743 * pages are left in the zone after a successful __alloc_pages().
6745 static void setup_per_zone_lowmem_reserve(void)
6747 struct pglist_data *pgdat;
6748 enum zone_type j, idx;
6750 for_each_online_pgdat(pgdat) {
6751 for (j = 0; j < MAX_NR_ZONES; j++) {
6752 struct zone *zone = pgdat->node_zones + j;
6753 unsigned long managed_pages = zone->managed_pages;
6755 zone->lowmem_reserve[j] = 0;
6759 struct zone *lower_zone;
6763 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6764 sysctl_lowmem_reserve_ratio[idx] = 1;
6766 lower_zone = pgdat->node_zones + idx;
6767 lower_zone->lowmem_reserve[j] = managed_pages /
6768 sysctl_lowmem_reserve_ratio[idx];
6769 managed_pages += lower_zone->managed_pages;
6774 /* update totalreserve_pages */
6775 calculate_totalreserve_pages();
6778 static void __setup_per_zone_wmarks(void)
6780 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6781 unsigned long lowmem_pages = 0;
6783 unsigned long flags;
6785 /* Calculate total number of !ZONE_HIGHMEM pages */
6786 for_each_zone(zone) {
6787 if (!is_highmem(zone))
6788 lowmem_pages += zone->managed_pages;
6791 for_each_zone(zone) {
6794 spin_lock_irqsave(&zone->lock, flags);
6795 tmp = (u64)pages_min * zone->managed_pages;
6796 do_div(tmp, lowmem_pages);
6797 if (is_highmem(zone)) {
6799 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6800 * need highmem pages, so cap pages_min to a small
6803 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6804 * deltas control asynch page reclaim, and so should
6805 * not be capped for highmem.
6807 unsigned long min_pages;
6809 min_pages = zone->managed_pages / 1024;
6810 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6811 zone->watermark[WMARK_MIN] = min_pages;
6814 * If it's a lowmem zone, reserve a number of pages
6815 * proportionate to the zone's size.
6817 zone->watermark[WMARK_MIN] = tmp;
6821 * Set the kswapd watermarks distance according to the
6822 * scale factor in proportion to available memory, but
6823 * ensure a minimum size on small systems.
6825 tmp = max_t(u64, tmp >> 2,
6826 mult_frac(zone->managed_pages,
6827 watermark_scale_factor, 10000));
6829 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6830 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6832 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6833 high_wmark_pages(zone) - low_wmark_pages(zone) -
6834 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6836 spin_unlock_irqrestore(&zone->lock, flags);
6839 /* update totalreserve_pages */
6840 calculate_totalreserve_pages();
6844 * setup_per_zone_wmarks - called when min_free_kbytes changes
6845 * or when memory is hot-{added|removed}
6847 * Ensures that the watermark[min,low,high] values for each zone are set
6848 * correctly with respect to min_free_kbytes.
6850 void setup_per_zone_wmarks(void)
6852 mutex_lock(&zonelists_mutex);
6853 __setup_per_zone_wmarks();
6854 mutex_unlock(&zonelists_mutex);
6858 * Initialise min_free_kbytes.
6860 * For small machines we want it small (128k min). For large machines
6861 * we want it large (64MB max). But it is not linear, because network
6862 * bandwidth does not increase linearly with machine size. We use
6864 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6865 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6881 int __meminit init_per_zone_wmark_min(void)
6883 unsigned long lowmem_kbytes;
6884 int new_min_free_kbytes;
6886 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6887 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6889 if (new_min_free_kbytes > user_min_free_kbytes) {
6890 min_free_kbytes = new_min_free_kbytes;
6891 if (min_free_kbytes < 128)
6892 min_free_kbytes = 128;
6893 if (min_free_kbytes > 65536)
6894 min_free_kbytes = 65536;
6896 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6897 new_min_free_kbytes, user_min_free_kbytes);
6899 setup_per_zone_wmarks();
6900 refresh_zone_stat_thresholds();
6901 setup_per_zone_lowmem_reserve();
6904 core_initcall(init_per_zone_wmark_min)
6907 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6908 * that we can call two helper functions whenever min_free_kbytes
6911 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6912 void __user *buffer, size_t *length, loff_t *ppos)
6916 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6921 user_min_free_kbytes = min_free_kbytes;
6922 setup_per_zone_wmarks();
6927 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6928 void __user *buffer, size_t *length, loff_t *ppos)
6932 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6937 setup_per_zone_wmarks();
6943 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6944 void __user *buffer, size_t *length, loff_t *ppos)
6949 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6954 zone->min_unmapped_pages = (zone->managed_pages *
6955 sysctl_min_unmapped_ratio) / 100;
6959 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6960 void __user *buffer, size_t *length, loff_t *ppos)
6965 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6970 zone->min_slab_pages = (zone->managed_pages *
6971 sysctl_min_slab_ratio) / 100;
6977 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6978 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6979 * whenever sysctl_lowmem_reserve_ratio changes.
6981 * The reserve ratio obviously has absolutely no relation with the
6982 * minimum watermarks. The lowmem reserve ratio can only make sense
6983 * if in function of the boot time zone sizes.
6985 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6986 void __user *buffer, size_t *length, loff_t *ppos)
6988 proc_dointvec_minmax(table, write, buffer, length, ppos);
6989 setup_per_zone_lowmem_reserve();
6994 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6995 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6996 * pagelist can have before it gets flushed back to buddy allocator.
6998 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6999 void __user *buffer, size_t *length, loff_t *ppos)
7002 int old_percpu_pagelist_fraction;
7005 mutex_lock(&pcp_batch_high_lock);
7006 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
7008 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
7009 if (!write || ret < 0)
7012 /* Sanity checking to avoid pcp imbalance */
7013 if (percpu_pagelist_fraction &&
7014 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
7015 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
7021 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
7024 for_each_populated_zone(zone) {
7027 for_each_possible_cpu(cpu)
7028 pageset_set_high_and_batch(zone,
7029 per_cpu_ptr(zone->pageset, cpu));
7032 mutex_unlock(&pcp_batch_high_lock);
7037 int hashdist = HASHDIST_DEFAULT;
7039 static int __init set_hashdist(char *str)
7043 hashdist = simple_strtoul(str, &str, 0);
7046 __setup("hashdist=", set_hashdist);
7050 * allocate a large system hash table from bootmem
7051 * - it is assumed that the hash table must contain an exact power-of-2
7052 * quantity of entries
7053 * - limit is the number of hash buckets, not the total allocation size
7055 void *__init alloc_large_system_hash(const char *tablename,
7056 unsigned long bucketsize,
7057 unsigned long numentries,
7060 unsigned int *_hash_shift,
7061 unsigned int *_hash_mask,
7062 unsigned long low_limit,
7063 unsigned long high_limit)
7065 unsigned long long max = high_limit;
7066 unsigned long log2qty, size;
7069 /* allow the kernel cmdline to have a say */
7071 /* round applicable memory size up to nearest megabyte */
7072 numentries = nr_kernel_pages;
7074 /* It isn't necessary when PAGE_SIZE >= 1MB */
7075 if (PAGE_SHIFT < 20)
7076 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
7078 /* limit to 1 bucket per 2^scale bytes of low memory */
7079 if (scale > PAGE_SHIFT)
7080 numentries >>= (scale - PAGE_SHIFT);
7082 numentries <<= (PAGE_SHIFT - scale);
7084 /* Make sure we've got at least a 0-order allocation.. */
7085 if (unlikely(flags & HASH_SMALL)) {
7086 /* Makes no sense without HASH_EARLY */
7087 WARN_ON(!(flags & HASH_EARLY));
7088 if (!(numentries >> *_hash_shift)) {
7089 numentries = 1UL << *_hash_shift;
7090 BUG_ON(!numentries);
7092 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
7093 numentries = PAGE_SIZE / bucketsize;
7095 numentries = roundup_pow_of_two(numentries);
7097 /* limit allocation size to 1/16 total memory by default */
7099 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
7100 do_div(max, bucketsize);
7102 max = min(max, 0x80000000ULL);
7104 if (numentries < low_limit)
7105 numentries = low_limit;
7106 if (numentries > max)
7109 log2qty = ilog2(numentries);
7112 size = bucketsize << log2qty;
7113 if (flags & HASH_EARLY)
7114 table = memblock_virt_alloc_nopanic(size, 0);
7116 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
7119 * If bucketsize is not a power-of-two, we may free
7120 * some pages at the end of hash table which
7121 * alloc_pages_exact() automatically does
7123 if (get_order(size) < MAX_ORDER) {
7124 table = alloc_pages_exact(size, GFP_ATOMIC);
7125 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
7128 } while (!table && size > PAGE_SIZE && --log2qty);
7131 panic("Failed to allocate %s hash table\n", tablename);
7133 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7134 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7137 *_hash_shift = log2qty;
7139 *_hash_mask = (1 << log2qty) - 1;
7145 * This function checks whether pageblock includes unmovable pages or not.
7146 * If @count is not zero, it is okay to include less @count unmovable pages
7148 * PageLRU check without isolation or lru_lock could race so that
7149 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7150 * expect this function should be exact.
7152 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7153 bool skip_hwpoisoned_pages)
7155 unsigned long pfn, iter, found;
7159 * For avoiding noise data, lru_add_drain_all() should be called
7160 * If ZONE_MOVABLE, the zone never contains unmovable pages
7162 if (zone_idx(zone) == ZONE_MOVABLE)
7164 mt = get_pageblock_migratetype(page);
7165 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
7168 pfn = page_to_pfn(page);
7169 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7170 unsigned long check = pfn + iter;
7172 if (!pfn_valid_within(check))
7175 page = pfn_to_page(check);
7178 * Hugepages are not in LRU lists, but they're movable.
7179 * We need not scan over tail pages bacause we don't
7180 * handle each tail page individually in migration.
7182 if (PageHuge(page)) {
7183 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7188 * We can't use page_count without pin a page
7189 * because another CPU can free compound page.
7190 * This check already skips compound tails of THP
7191 * because their page->_refcount is zero at all time.
7193 if (!page_ref_count(page)) {
7194 if (PageBuddy(page))
7195 iter += (1 << page_order(page)) - 1;
7200 * The HWPoisoned page may be not in buddy system, and
7201 * page_count() is not 0.
7203 if (skip_hwpoisoned_pages && PageHWPoison(page))
7209 * If there are RECLAIMABLE pages, we need to check
7210 * it. But now, memory offline itself doesn't call
7211 * shrink_node_slabs() and it still to be fixed.
7214 * If the page is not RAM, page_count()should be 0.
7215 * we don't need more check. This is an _used_ not-movable page.
7217 * The problematic thing here is PG_reserved pages. PG_reserved
7218 * is set to both of a memory hole page and a _used_ kernel
7227 bool is_pageblock_removable_nolock(struct page *page)
7233 * We have to be careful here because we are iterating over memory
7234 * sections which are not zone aware so we might end up outside of
7235 * the zone but still within the section.
7236 * We have to take care about the node as well. If the node is offline
7237 * its NODE_DATA will be NULL - see page_zone.
7239 if (!node_online(page_to_nid(page)))
7242 zone = page_zone(page);
7243 pfn = page_to_pfn(page);
7244 if (!zone_spans_pfn(zone, pfn))
7247 return !has_unmovable_pages(zone, page, 0, true);
7250 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7252 static unsigned long pfn_max_align_down(unsigned long pfn)
7254 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7255 pageblock_nr_pages) - 1);
7258 static unsigned long pfn_max_align_up(unsigned long pfn)
7260 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7261 pageblock_nr_pages));
7264 /* [start, end) must belong to a single zone. */
7265 static int __alloc_contig_migrate_range(struct compact_control *cc,
7266 unsigned long start, unsigned long end)
7268 /* This function is based on compact_zone() from compaction.c. */
7269 unsigned long nr_reclaimed;
7270 unsigned long pfn = start;
7271 unsigned int tries = 0;
7276 while (pfn < end || !list_empty(&cc->migratepages)) {
7277 if (fatal_signal_pending(current)) {
7282 if (list_empty(&cc->migratepages)) {
7283 cc->nr_migratepages = 0;
7284 pfn = isolate_migratepages_range(cc, pfn, end);
7290 } else if (++tries == 5) {
7291 ret = ret < 0 ? ret : -EBUSY;
7295 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7297 cc->nr_migratepages -= nr_reclaimed;
7299 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7300 NULL, 0, cc->mode, MR_CMA);
7303 putback_movable_pages(&cc->migratepages);
7310 * alloc_contig_range() -- tries to allocate given range of pages
7311 * @start: start PFN to allocate
7312 * @end: one-past-the-last PFN to allocate
7313 * @migratetype: migratetype of the underlaying pageblocks (either
7314 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7315 * in range must have the same migratetype and it must
7316 * be either of the two.
7318 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7319 * aligned, however it's the caller's responsibility to guarantee that
7320 * we are the only thread that changes migrate type of pageblocks the
7323 * The PFN range must belong to a single zone.
7325 * Returns zero on success or negative error code. On success all
7326 * pages which PFN is in [start, end) are allocated for the caller and
7327 * need to be freed with free_contig_range().
7329 int alloc_contig_range(unsigned long start, unsigned long end,
7330 unsigned migratetype)
7332 unsigned long outer_start, outer_end;
7336 struct compact_control cc = {
7337 .nr_migratepages = 0,
7339 .zone = page_zone(pfn_to_page(start)),
7340 .mode = MIGRATE_SYNC,
7341 .ignore_skip_hint = true,
7343 INIT_LIST_HEAD(&cc.migratepages);
7346 * What we do here is we mark all pageblocks in range as
7347 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7348 * have different sizes, and due to the way page allocator
7349 * work, we align the range to biggest of the two pages so
7350 * that page allocator won't try to merge buddies from
7351 * different pageblocks and change MIGRATE_ISOLATE to some
7352 * other migration type.
7354 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7355 * migrate the pages from an unaligned range (ie. pages that
7356 * we are interested in). This will put all the pages in
7357 * range back to page allocator as MIGRATE_ISOLATE.
7359 * When this is done, we take the pages in range from page
7360 * allocator removing them from the buddy system. This way
7361 * page allocator will never consider using them.
7363 * This lets us mark the pageblocks back as
7364 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7365 * aligned range but not in the unaligned, original range are
7366 * put back to page allocator so that buddy can use them.
7369 ret = start_isolate_page_range(pfn_max_align_down(start),
7370 pfn_max_align_up(end), migratetype,
7376 * In case of -EBUSY, we'd like to know which page causes problem.
7377 * So, just fall through. We will check it in test_pages_isolated().
7379 ret = __alloc_contig_migrate_range(&cc, start, end);
7380 if (ret && ret != -EBUSY)
7384 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7385 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7386 * more, all pages in [start, end) are free in page allocator.
7387 * What we are going to do is to allocate all pages from
7388 * [start, end) (that is remove them from page allocator).
7390 * The only problem is that pages at the beginning and at the
7391 * end of interesting range may be not aligned with pages that
7392 * page allocator holds, ie. they can be part of higher order
7393 * pages. Because of this, we reserve the bigger range and
7394 * once this is done free the pages we are not interested in.
7396 * We don't have to hold zone->lock here because the pages are
7397 * isolated thus they won't get removed from buddy.
7400 lru_add_drain_all();
7401 drain_all_pages(cc.zone);
7404 outer_start = start;
7405 while (!PageBuddy(pfn_to_page(outer_start))) {
7406 if (++order >= MAX_ORDER) {
7407 outer_start = start;
7410 outer_start &= ~0UL << order;
7413 if (outer_start != start) {
7414 order = page_order(pfn_to_page(outer_start));
7417 * outer_start page could be small order buddy page and
7418 * it doesn't include start page. Adjust outer_start
7419 * in this case to report failed page properly
7420 * on tracepoint in test_pages_isolated()
7422 if (outer_start + (1UL << order) <= start)
7423 outer_start = start;
7426 /* Make sure the range is really isolated. */
7427 if (test_pages_isolated(outer_start, end, false)) {
7428 pr_info("%s: [%lx, %lx) PFNs busy\n",
7429 __func__, outer_start, end);
7434 /* Grab isolated pages from freelists. */
7435 outer_end = isolate_freepages_range(&cc, outer_start, end);
7441 /* Free head and tail (if any) */
7442 if (start != outer_start)
7443 free_contig_range(outer_start, start - outer_start);
7444 if (end != outer_end)
7445 free_contig_range(end, outer_end - end);
7448 undo_isolate_page_range(pfn_max_align_down(start),
7449 pfn_max_align_up(end), migratetype);
7453 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7455 unsigned int count = 0;
7457 for (; nr_pages--; pfn++) {
7458 struct page *page = pfn_to_page(pfn);
7460 count += page_count(page) != 1;
7463 WARN(count != 0, "%d pages are still in use!\n", count);
7467 #ifdef CONFIG_MEMORY_HOTPLUG
7469 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7470 * page high values need to be recalulated.
7472 void __meminit zone_pcp_update(struct zone *zone)
7475 mutex_lock(&pcp_batch_high_lock);
7476 for_each_possible_cpu(cpu)
7477 pageset_set_high_and_batch(zone,
7478 per_cpu_ptr(zone->pageset, cpu));
7479 mutex_unlock(&pcp_batch_high_lock);
7483 void zone_pcp_reset(struct zone *zone)
7485 unsigned long flags;
7487 struct per_cpu_pageset *pset;
7489 /* avoid races with drain_pages() */
7490 local_irq_save(flags);
7491 if (zone->pageset != &boot_pageset) {
7492 for_each_online_cpu(cpu) {
7493 pset = per_cpu_ptr(zone->pageset, cpu);
7494 drain_zonestat(zone, pset);
7496 free_percpu(zone->pageset);
7497 zone->pageset = &boot_pageset;
7499 local_irq_restore(flags);
7502 #ifdef CONFIG_MEMORY_HOTREMOVE
7504 * All pages in the range must be in a single zone and isolated
7505 * before calling this.
7508 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7512 unsigned int order, i;
7514 unsigned long flags;
7515 /* find the first valid pfn */
7516 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7521 zone = page_zone(pfn_to_page(pfn));
7522 spin_lock_irqsave(&zone->lock, flags);
7524 while (pfn < end_pfn) {
7525 if (!pfn_valid(pfn)) {
7529 page = pfn_to_page(pfn);
7531 * The HWPoisoned page may be not in buddy system, and
7532 * page_count() is not 0.
7534 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7536 SetPageReserved(page);
7540 BUG_ON(page_count(page));
7541 BUG_ON(!PageBuddy(page));
7542 order = page_order(page);
7543 #ifdef CONFIG_DEBUG_VM
7544 pr_info("remove from free list %lx %d %lx\n",
7545 pfn, 1 << order, end_pfn);
7547 list_del(&page->lru);
7548 rmv_page_order(page);
7549 zone->free_area[order].nr_free--;
7550 for (i = 0; i < (1 << order); i++)
7551 SetPageReserved((page+i));
7552 pfn += (1 << order);
7554 spin_unlock_irqrestore(&zone->lock, flags);
7558 bool is_free_buddy_page(struct page *page)
7560 struct zone *zone = page_zone(page);
7561 unsigned long pfn = page_to_pfn(page);
7562 unsigned long flags;
7565 spin_lock_irqsave(&zone->lock, flags);
7566 for (order = 0; order < MAX_ORDER; order++) {
7567 struct page *page_head = page - (pfn & ((1 << order) - 1));
7569 if (PageBuddy(page_head) && page_order(page_head) >= order)
7572 spin_unlock_irqrestore(&zone->lock, flags);
7574 return order < MAX_ORDER;