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 <trace/events/oom.h>
59 #include <linux/prefetch.h>
60 #include <linux/mm_inline.h>
61 #include <linux/migrate.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/sched/mm.h>
65 #include <linux/page_owner.h>
66 #include <linux/kthread.h>
67 #include <linux/memcontrol.h>
68 #include <linux/ftrace.h>
70 #include <asm/sections.h>
71 #include <asm/tlbflush.h>
72 #include <asm/div64.h>
75 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
76 static DEFINE_MUTEX(pcp_batch_high_lock);
77 #define MIN_PERCPU_PAGELIST_FRACTION (8)
79 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
80 DEFINE_PER_CPU(int, numa_node);
81 EXPORT_PER_CPU_SYMBOL(numa_node);
84 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
86 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
87 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
88 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
89 * defined in <linux/topology.h>.
91 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
92 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
93 int _node_numa_mem_[MAX_NUMNODES];
96 /* work_structs for global per-cpu drains */
97 DEFINE_MUTEX(pcpu_drain_mutex);
98 DEFINE_PER_CPU(struct work_struct, pcpu_drain);
100 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
101 volatile unsigned long latent_entropy __latent_entropy;
102 EXPORT_SYMBOL(latent_entropy);
106 * Array of node states.
108 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
109 [N_POSSIBLE] = NODE_MASK_ALL,
110 [N_ONLINE] = { { [0] = 1UL } },
112 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
113 #ifdef CONFIG_HIGHMEM
114 [N_HIGH_MEMORY] = { { [0] = 1UL } },
116 #ifdef CONFIG_MOVABLE_NODE
117 [N_MEMORY] = { { [0] = 1UL } },
119 [N_CPU] = { { [0] = 1UL } },
122 EXPORT_SYMBOL(node_states);
124 /* Protect totalram_pages and zone->managed_pages */
125 static DEFINE_SPINLOCK(managed_page_count_lock);
127 unsigned long totalram_pages __read_mostly;
128 unsigned long totalreserve_pages __read_mostly;
129 unsigned long totalcma_pages __read_mostly;
131 int percpu_pagelist_fraction;
132 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
135 * A cached value of the page's pageblock's migratetype, used when the page is
136 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
137 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
138 * Also the migratetype set in the page does not necessarily match the pcplist
139 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
140 * other index - this ensures that it will be put on the correct CMA freelist.
142 static inline int get_pcppage_migratetype(struct page *page)
147 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
149 page->index = migratetype;
152 #ifdef CONFIG_PM_SLEEP
154 * The following functions are used by the suspend/hibernate code to temporarily
155 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
156 * while devices are suspended. To avoid races with the suspend/hibernate code,
157 * they should always be called with pm_mutex held (gfp_allowed_mask also should
158 * only be modified with pm_mutex held, unless the suspend/hibernate code is
159 * guaranteed not to run in parallel with that modification).
162 static gfp_t saved_gfp_mask;
164 void pm_restore_gfp_mask(void)
166 WARN_ON(!mutex_is_locked(&pm_mutex));
167 if (saved_gfp_mask) {
168 gfp_allowed_mask = saved_gfp_mask;
173 void pm_restrict_gfp_mask(void)
175 WARN_ON(!mutex_is_locked(&pm_mutex));
176 WARN_ON(saved_gfp_mask);
177 saved_gfp_mask = gfp_allowed_mask;
178 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
181 bool pm_suspended_storage(void)
183 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
187 #endif /* CONFIG_PM_SLEEP */
189 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
190 unsigned int pageblock_order __read_mostly;
193 static void __free_pages_ok(struct page *page, unsigned int order);
196 * results with 256, 32 in the lowmem_reserve sysctl:
197 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
198 * 1G machine -> (16M dma, 784M normal, 224M high)
199 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
200 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
201 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
203 * TBD: should special case ZONE_DMA32 machines here - in those we normally
204 * don't need any ZONE_NORMAL reservation
206 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
207 #ifdef CONFIG_ZONE_DMA
210 #ifdef CONFIG_ZONE_DMA32
213 #ifdef CONFIG_HIGHMEM
219 EXPORT_SYMBOL(totalram_pages);
221 static char * const zone_names[MAX_NR_ZONES] = {
222 #ifdef CONFIG_ZONE_DMA
225 #ifdef CONFIG_ZONE_DMA32
229 #ifdef CONFIG_HIGHMEM
233 #ifdef CONFIG_ZONE_DEVICE
238 char * const migratetype_names[MIGRATE_TYPES] = {
246 #ifdef CONFIG_MEMORY_ISOLATION
251 compound_page_dtor * const compound_page_dtors[] = {
254 #ifdef CONFIG_HUGETLB_PAGE
257 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
262 int min_free_kbytes = 1024;
263 int user_min_free_kbytes = -1;
264 int watermark_scale_factor = 10;
266 static unsigned long __meminitdata nr_kernel_pages;
267 static unsigned long __meminitdata nr_all_pages;
268 static unsigned long __meminitdata dma_reserve;
270 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
271 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
272 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
273 static unsigned long __initdata required_kernelcore;
274 static unsigned long __initdata required_movablecore;
275 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
276 static bool mirrored_kernelcore;
278 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
280 EXPORT_SYMBOL(movable_zone);
281 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
284 int nr_node_ids __read_mostly = MAX_NUMNODES;
285 int nr_online_nodes __read_mostly = 1;
286 EXPORT_SYMBOL(nr_node_ids);
287 EXPORT_SYMBOL(nr_online_nodes);
290 int page_group_by_mobility_disabled __read_mostly;
292 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
293 static inline void reset_deferred_meminit(pg_data_t *pgdat)
295 unsigned long max_initialise;
296 unsigned long reserved_lowmem;
299 * Initialise at least 2G of a node but also take into account that
300 * two large system hashes that can take up 1GB for 0.25TB/node.
302 max_initialise = max(2UL << (30 - PAGE_SHIFT),
303 (pgdat->node_spanned_pages >> 8));
306 * Compensate the all the memblock reservations (e.g. crash kernel)
307 * from the initial estimation to make sure we will initialize enough
310 reserved_lowmem = memblock_reserved_memory_within(pgdat->node_start_pfn,
311 pgdat->node_start_pfn + max_initialise);
312 max_initialise += reserved_lowmem;
314 pgdat->static_init_size = min(max_initialise, pgdat->node_spanned_pages);
315 pgdat->first_deferred_pfn = ULONG_MAX;
318 /* Returns true if the struct page for the pfn is uninitialised */
319 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
321 int nid = early_pfn_to_nid(pfn);
323 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
330 * Returns false when the remaining initialisation should be deferred until
331 * later in the boot cycle when it can be parallelised.
333 static inline bool update_defer_init(pg_data_t *pgdat,
334 unsigned long pfn, unsigned long zone_end,
335 unsigned long *nr_initialised)
337 /* Always populate low zones for address-contrained allocations */
338 if (zone_end < pgdat_end_pfn(pgdat))
341 if ((*nr_initialised > pgdat->static_init_size) &&
342 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
343 pgdat->first_deferred_pfn = pfn;
350 static inline void reset_deferred_meminit(pg_data_t *pgdat)
354 static inline bool early_page_uninitialised(unsigned long pfn)
359 static inline bool update_defer_init(pg_data_t *pgdat,
360 unsigned long pfn, unsigned long zone_end,
361 unsigned long *nr_initialised)
367 /* Return a pointer to the bitmap storing bits affecting a block of pages */
368 static inline unsigned long *get_pageblock_bitmap(struct page *page,
371 #ifdef CONFIG_SPARSEMEM
372 return __pfn_to_section(pfn)->pageblock_flags;
374 return page_zone(page)->pageblock_flags;
375 #endif /* CONFIG_SPARSEMEM */
378 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
380 #ifdef CONFIG_SPARSEMEM
381 pfn &= (PAGES_PER_SECTION-1);
382 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
384 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
385 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
386 #endif /* CONFIG_SPARSEMEM */
390 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
391 * @page: The page within the block of interest
392 * @pfn: The target page frame number
393 * @end_bitidx: The last bit of interest to retrieve
394 * @mask: mask of bits that the caller is interested in
396 * Return: pageblock_bits flags
398 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
400 unsigned long end_bitidx,
403 unsigned long *bitmap;
404 unsigned long bitidx, word_bitidx;
407 bitmap = get_pageblock_bitmap(page, pfn);
408 bitidx = pfn_to_bitidx(page, pfn);
409 word_bitidx = bitidx / BITS_PER_LONG;
410 bitidx &= (BITS_PER_LONG-1);
412 word = bitmap[word_bitidx];
413 bitidx += end_bitidx;
414 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
417 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
418 unsigned long end_bitidx,
421 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
424 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
426 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
430 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
431 * @page: The page within the block of interest
432 * @flags: The flags to set
433 * @pfn: The target page frame number
434 * @end_bitidx: The last bit of interest
435 * @mask: mask of bits that the caller is interested in
437 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
439 unsigned long end_bitidx,
442 unsigned long *bitmap;
443 unsigned long bitidx, word_bitidx;
444 unsigned long old_word, word;
446 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
448 bitmap = get_pageblock_bitmap(page, pfn);
449 bitidx = pfn_to_bitidx(page, pfn);
450 word_bitidx = bitidx / BITS_PER_LONG;
451 bitidx &= (BITS_PER_LONG-1);
453 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
455 bitidx += end_bitidx;
456 mask <<= (BITS_PER_LONG - bitidx - 1);
457 flags <<= (BITS_PER_LONG - bitidx - 1);
459 word = READ_ONCE(bitmap[word_bitidx]);
461 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
462 if (word == old_word)
468 void set_pageblock_migratetype(struct page *page, int migratetype)
470 if (unlikely(page_group_by_mobility_disabled &&
471 migratetype < MIGRATE_PCPTYPES))
472 migratetype = MIGRATE_UNMOVABLE;
474 set_pageblock_flags_group(page, (unsigned long)migratetype,
475 PB_migrate, PB_migrate_end);
478 #ifdef CONFIG_DEBUG_VM
479 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
483 unsigned long pfn = page_to_pfn(page);
484 unsigned long sp, start_pfn;
487 seq = zone_span_seqbegin(zone);
488 start_pfn = zone->zone_start_pfn;
489 sp = zone->spanned_pages;
490 if (!zone_spans_pfn(zone, pfn))
492 } while (zone_span_seqretry(zone, seq));
495 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
496 pfn, zone_to_nid(zone), zone->name,
497 start_pfn, start_pfn + sp);
502 static int page_is_consistent(struct zone *zone, struct page *page)
504 if (!pfn_valid_within(page_to_pfn(page)))
506 if (zone != page_zone(page))
512 * Temporary debugging check for pages not lying within a given zone.
514 static int bad_range(struct zone *zone, struct page *page)
516 if (page_outside_zone_boundaries(zone, page))
518 if (!page_is_consistent(zone, page))
524 static inline int bad_range(struct zone *zone, struct page *page)
530 static void bad_page(struct page *page, const char *reason,
531 unsigned long bad_flags)
533 static unsigned long resume;
534 static unsigned long nr_shown;
535 static unsigned long nr_unshown;
538 * Allow a burst of 60 reports, then keep quiet for that minute;
539 * or allow a steady drip of one report per second.
541 if (nr_shown == 60) {
542 if (time_before(jiffies, resume)) {
548 "BUG: Bad page state: %lu messages suppressed\n",
555 resume = jiffies + 60 * HZ;
557 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
558 current->comm, page_to_pfn(page));
559 __dump_page(page, reason);
560 bad_flags &= page->flags;
562 pr_alert("bad because of flags: %#lx(%pGp)\n",
563 bad_flags, &bad_flags);
564 dump_page_owner(page);
569 /* Leave bad fields for debug, except PageBuddy could make trouble */
570 page_mapcount_reset(page); /* remove PageBuddy */
571 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
575 * Higher-order pages are called "compound pages". They are structured thusly:
577 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
579 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
580 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
582 * The first tail page's ->compound_dtor holds the offset in array of compound
583 * page destructors. See compound_page_dtors.
585 * The first tail page's ->compound_order holds the order of allocation.
586 * This usage means that zero-order pages may not be compound.
589 void free_compound_page(struct page *page)
591 __free_pages_ok(page, compound_order(page));
594 void prep_compound_page(struct page *page, unsigned int order)
597 int nr_pages = 1 << order;
599 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
600 set_compound_order(page, order);
602 for (i = 1; i < nr_pages; i++) {
603 struct page *p = page + i;
604 set_page_count(p, 0);
605 p->mapping = TAIL_MAPPING;
606 set_compound_head(p, page);
608 atomic_set(compound_mapcount_ptr(page), -1);
611 #ifdef CONFIG_DEBUG_PAGEALLOC
612 unsigned int _debug_guardpage_minorder;
613 bool _debug_pagealloc_enabled __read_mostly
614 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
615 EXPORT_SYMBOL(_debug_pagealloc_enabled);
616 bool _debug_guardpage_enabled __read_mostly;
618 static int __init early_debug_pagealloc(char *buf)
622 return kstrtobool(buf, &_debug_pagealloc_enabled);
624 early_param("debug_pagealloc", early_debug_pagealloc);
626 static bool need_debug_guardpage(void)
628 /* If we don't use debug_pagealloc, we don't need guard page */
629 if (!debug_pagealloc_enabled())
632 if (!debug_guardpage_minorder())
638 static void init_debug_guardpage(void)
640 if (!debug_pagealloc_enabled())
643 if (!debug_guardpage_minorder())
646 _debug_guardpage_enabled = true;
649 struct page_ext_operations debug_guardpage_ops = {
650 .need = need_debug_guardpage,
651 .init = init_debug_guardpage,
654 static int __init debug_guardpage_minorder_setup(char *buf)
658 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
659 pr_err("Bad debug_guardpage_minorder value\n");
662 _debug_guardpage_minorder = res;
663 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
666 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
668 static inline bool set_page_guard(struct zone *zone, struct page *page,
669 unsigned int order, int migratetype)
671 struct page_ext *page_ext;
673 if (!debug_guardpage_enabled())
676 if (order >= debug_guardpage_minorder())
679 page_ext = lookup_page_ext(page);
680 if (unlikely(!page_ext))
683 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
685 INIT_LIST_HEAD(&page->lru);
686 set_page_private(page, order);
687 /* Guard pages are not available for any usage */
688 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
693 static inline void clear_page_guard(struct zone *zone, struct page *page,
694 unsigned int order, int migratetype)
696 struct page_ext *page_ext;
698 if (!debug_guardpage_enabled())
701 page_ext = lookup_page_ext(page);
702 if (unlikely(!page_ext))
705 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
707 set_page_private(page, 0);
708 if (!is_migrate_isolate(migratetype))
709 __mod_zone_freepage_state(zone, (1 << order), migratetype);
712 struct page_ext_operations debug_guardpage_ops;
713 static inline bool set_page_guard(struct zone *zone, struct page *page,
714 unsigned int order, int migratetype) { return false; }
715 static inline void clear_page_guard(struct zone *zone, struct page *page,
716 unsigned int order, int migratetype) {}
719 static inline void set_page_order(struct page *page, unsigned int order)
721 set_page_private(page, order);
722 __SetPageBuddy(page);
725 static inline void rmv_page_order(struct page *page)
727 __ClearPageBuddy(page);
728 set_page_private(page, 0);
732 * This function checks whether a page is free && is the buddy
733 * we can do coalesce a page and its buddy if
734 * (a) the buddy is not in a hole (check before calling!) &&
735 * (b) the buddy is in the buddy system &&
736 * (c) a page and its buddy have the same order &&
737 * (d) a page and its buddy are in the same zone.
739 * For recording whether a page is in the buddy system, we set ->_mapcount
740 * PAGE_BUDDY_MAPCOUNT_VALUE.
741 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
742 * serialized by zone->lock.
744 * For recording page's order, we use page_private(page).
746 static inline int page_is_buddy(struct page *page, struct page *buddy,
749 if (page_is_guard(buddy) && page_order(buddy) == order) {
750 if (page_zone_id(page) != page_zone_id(buddy))
753 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
758 if (PageBuddy(buddy) && page_order(buddy) == order) {
760 * zone check is done late to avoid uselessly
761 * calculating zone/node ids for pages that could
764 if (page_zone_id(page) != page_zone_id(buddy))
767 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
775 * Freeing function for a buddy system allocator.
777 * The concept of a buddy system is to maintain direct-mapped table
778 * (containing bit values) for memory blocks of various "orders".
779 * The bottom level table contains the map for the smallest allocatable
780 * units of memory (here, pages), and each level above it describes
781 * pairs of units from the levels below, hence, "buddies".
782 * At a high level, all that happens here is marking the table entry
783 * at the bottom level available, and propagating the changes upward
784 * as necessary, plus some accounting needed to play nicely with other
785 * parts of the VM system.
786 * At each level, we keep a list of pages, which are heads of continuous
787 * free pages of length of (1 << order) and marked with _mapcount
788 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
790 * So when we are allocating or freeing one, we can derive the state of the
791 * other. That is, if we allocate a small block, and both were
792 * free, the remainder of the region must be split into blocks.
793 * If a block is freed, and its buddy is also free, then this
794 * triggers coalescing into a block of larger size.
799 static inline void __free_one_page(struct page *page,
801 struct zone *zone, unsigned int order,
804 unsigned long combined_pfn;
805 unsigned long uninitialized_var(buddy_pfn);
807 unsigned int max_order;
809 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
811 VM_BUG_ON(!zone_is_initialized(zone));
812 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
814 VM_BUG_ON(migratetype == -1);
815 if (likely(!is_migrate_isolate(migratetype)))
816 __mod_zone_freepage_state(zone, 1 << order, migratetype);
818 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
819 VM_BUG_ON_PAGE(bad_range(zone, page), page);
822 while (order < max_order - 1) {
823 buddy_pfn = __find_buddy_pfn(pfn, order);
824 buddy = page + (buddy_pfn - pfn);
826 if (!pfn_valid_within(buddy_pfn))
828 if (!page_is_buddy(page, buddy, order))
831 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
832 * merge with it and move up one order.
834 if (page_is_guard(buddy)) {
835 clear_page_guard(zone, buddy, order, migratetype);
837 list_del(&buddy->lru);
838 zone->free_area[order].nr_free--;
839 rmv_page_order(buddy);
841 combined_pfn = buddy_pfn & pfn;
842 page = page + (combined_pfn - pfn);
846 if (max_order < MAX_ORDER) {
847 /* If we are here, it means order is >= pageblock_order.
848 * We want to prevent merge between freepages on isolate
849 * pageblock and normal pageblock. Without this, pageblock
850 * isolation could cause incorrect freepage or CMA accounting.
852 * We don't want to hit this code for the more frequent
855 if (unlikely(has_isolate_pageblock(zone))) {
858 buddy_pfn = __find_buddy_pfn(pfn, order);
859 buddy = page + (buddy_pfn - pfn);
860 buddy_mt = get_pageblock_migratetype(buddy);
862 if (migratetype != buddy_mt
863 && (is_migrate_isolate(migratetype) ||
864 is_migrate_isolate(buddy_mt)))
868 goto continue_merging;
872 set_page_order(page, order);
875 * If this is not the largest possible page, check if the buddy
876 * of the next-highest order is free. If it is, it's possible
877 * that pages are being freed that will coalesce soon. In case,
878 * that is happening, add the free page to the tail of the list
879 * so it's less likely to be used soon and more likely to be merged
880 * as a higher order page
882 if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) {
883 struct page *higher_page, *higher_buddy;
884 combined_pfn = buddy_pfn & pfn;
885 higher_page = page + (combined_pfn - pfn);
886 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
887 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
888 if (pfn_valid_within(buddy_pfn) &&
889 page_is_buddy(higher_page, higher_buddy, order + 1)) {
890 list_add_tail(&page->lru,
891 &zone->free_area[order].free_list[migratetype]);
896 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
898 zone->free_area[order].nr_free++;
902 * A bad page could be due to a number of fields. Instead of multiple branches,
903 * try and check multiple fields with one check. The caller must do a detailed
904 * check if necessary.
906 static inline bool page_expected_state(struct page *page,
907 unsigned long check_flags)
909 if (unlikely(atomic_read(&page->_mapcount) != -1))
912 if (unlikely((unsigned long)page->mapping |
913 page_ref_count(page) |
915 (unsigned long)page->mem_cgroup |
917 (page->flags & check_flags)))
923 static void free_pages_check_bad(struct page *page)
925 const char *bad_reason;
926 unsigned long bad_flags;
931 if (unlikely(atomic_read(&page->_mapcount) != -1))
932 bad_reason = "nonzero mapcount";
933 if (unlikely(page->mapping != NULL))
934 bad_reason = "non-NULL mapping";
935 if (unlikely(page_ref_count(page) != 0))
936 bad_reason = "nonzero _refcount";
937 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
938 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
939 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
942 if (unlikely(page->mem_cgroup))
943 bad_reason = "page still charged to cgroup";
945 bad_page(page, bad_reason, bad_flags);
948 static inline int free_pages_check(struct page *page)
950 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
953 /* Something has gone sideways, find it */
954 free_pages_check_bad(page);
958 static int free_tail_pages_check(struct page *head_page, struct page *page)
963 * We rely page->lru.next never has bit 0 set, unless the page
964 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
966 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
968 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
972 switch (page - head_page) {
974 /* the first tail page: ->mapping is compound_mapcount() */
975 if (unlikely(compound_mapcount(page))) {
976 bad_page(page, "nonzero compound_mapcount", 0);
982 * the second tail page: ->mapping is
983 * page_deferred_list().next -- ignore value.
987 if (page->mapping != TAIL_MAPPING) {
988 bad_page(page, "corrupted mapping in tail page", 0);
993 if (unlikely(!PageTail(page))) {
994 bad_page(page, "PageTail not set", 0);
997 if (unlikely(compound_head(page) != head_page)) {
998 bad_page(page, "compound_head not consistent", 0);
1003 page->mapping = NULL;
1004 clear_compound_head(page);
1008 static __always_inline bool free_pages_prepare(struct page *page,
1009 unsigned int order, bool check_free)
1013 VM_BUG_ON_PAGE(PageTail(page), page);
1015 trace_mm_page_free(page, order);
1016 kmemcheck_free_shadow(page, order);
1019 * Check tail pages before head page information is cleared to
1020 * avoid checking PageCompound for order-0 pages.
1022 if (unlikely(order)) {
1023 bool compound = PageCompound(page);
1026 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1029 ClearPageDoubleMap(page);
1030 for (i = 1; i < (1 << order); i++) {
1032 bad += free_tail_pages_check(page, page + i);
1033 if (unlikely(free_pages_check(page + i))) {
1037 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1040 if (PageMappingFlags(page))
1041 page->mapping = NULL;
1042 if (memcg_kmem_enabled() && PageKmemcg(page))
1043 memcg_kmem_uncharge(page, order);
1045 bad += free_pages_check(page);
1049 page_cpupid_reset_last(page);
1050 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1051 reset_page_owner(page, order);
1053 if (!PageHighMem(page)) {
1054 debug_check_no_locks_freed(page_address(page),
1055 PAGE_SIZE << order);
1056 debug_check_no_obj_freed(page_address(page),
1057 PAGE_SIZE << order);
1059 arch_free_page(page, order);
1060 kernel_poison_pages(page, 1 << order, 0);
1061 kernel_map_pages(page, 1 << order, 0);
1062 kasan_free_pages(page, order);
1067 #ifdef CONFIG_DEBUG_VM
1068 static inline bool free_pcp_prepare(struct page *page)
1070 return free_pages_prepare(page, 0, true);
1073 static inline bool bulkfree_pcp_prepare(struct page *page)
1078 static bool free_pcp_prepare(struct page *page)
1080 return free_pages_prepare(page, 0, false);
1083 static bool bulkfree_pcp_prepare(struct page *page)
1085 return free_pages_check(page);
1087 #endif /* CONFIG_DEBUG_VM */
1090 * Frees a number of pages from the PCP lists
1091 * Assumes all pages on list are in same zone, and of same order.
1092 * count is the number of pages to free.
1094 * If the zone was previously in an "all pages pinned" state then look to
1095 * see if this freeing clears that state.
1097 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1098 * pinned" detection logic.
1100 static void free_pcppages_bulk(struct zone *zone, int count,
1101 struct per_cpu_pages *pcp)
1103 int migratetype = 0;
1105 bool isolated_pageblocks;
1107 spin_lock(&zone->lock);
1108 isolated_pageblocks = has_isolate_pageblock(zone);
1112 struct list_head *list;
1115 * Remove pages from lists in a round-robin fashion. A
1116 * batch_free count is maintained that is incremented when an
1117 * empty list is encountered. This is so more pages are freed
1118 * off fuller lists instead of spinning excessively around empty
1123 if (++migratetype == MIGRATE_PCPTYPES)
1125 list = &pcp->lists[migratetype];
1126 } while (list_empty(list));
1128 /* This is the only non-empty list. Free them all. */
1129 if (batch_free == MIGRATE_PCPTYPES)
1133 int mt; /* migratetype of the to-be-freed page */
1135 page = list_last_entry(list, struct page, lru);
1136 /* must delete as __free_one_page list manipulates */
1137 list_del(&page->lru);
1139 mt = get_pcppage_migratetype(page);
1140 /* MIGRATE_ISOLATE page should not go to pcplists */
1141 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1142 /* Pageblock could have been isolated meanwhile */
1143 if (unlikely(isolated_pageblocks))
1144 mt = get_pageblock_migratetype(page);
1146 if (bulkfree_pcp_prepare(page))
1149 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1150 trace_mm_page_pcpu_drain(page, 0, mt);
1151 } while (--count && --batch_free && !list_empty(list));
1153 spin_unlock(&zone->lock);
1156 static void free_one_page(struct zone *zone,
1157 struct page *page, unsigned long pfn,
1161 spin_lock(&zone->lock);
1162 if (unlikely(has_isolate_pageblock(zone) ||
1163 is_migrate_isolate(migratetype))) {
1164 migratetype = get_pfnblock_migratetype(page, pfn);
1166 __free_one_page(page, pfn, zone, order, migratetype);
1167 spin_unlock(&zone->lock);
1170 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1171 unsigned long zone, int nid)
1173 set_page_links(page, zone, nid, pfn);
1174 init_page_count(page);
1175 page_mapcount_reset(page);
1176 page_cpupid_reset_last(page);
1178 INIT_LIST_HEAD(&page->lru);
1179 #ifdef WANT_PAGE_VIRTUAL
1180 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1181 if (!is_highmem_idx(zone))
1182 set_page_address(page, __va(pfn << PAGE_SHIFT));
1186 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
1189 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
1192 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1193 static void init_reserved_page(unsigned long pfn)
1198 if (!early_page_uninitialised(pfn))
1201 nid = early_pfn_to_nid(pfn);
1202 pgdat = NODE_DATA(nid);
1204 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1205 struct zone *zone = &pgdat->node_zones[zid];
1207 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1210 __init_single_pfn(pfn, zid, nid);
1213 static inline void init_reserved_page(unsigned long pfn)
1216 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1219 * Initialised pages do not have PageReserved set. This function is
1220 * called for each range allocated by the bootmem allocator and
1221 * marks the pages PageReserved. The remaining valid pages are later
1222 * sent to the buddy page allocator.
1224 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1226 unsigned long start_pfn = PFN_DOWN(start);
1227 unsigned long end_pfn = PFN_UP(end);
1229 for (; start_pfn < end_pfn; start_pfn++) {
1230 if (pfn_valid(start_pfn)) {
1231 struct page *page = pfn_to_page(start_pfn);
1233 init_reserved_page(start_pfn);
1235 /* Avoid false-positive PageTail() */
1236 INIT_LIST_HEAD(&page->lru);
1238 SetPageReserved(page);
1243 static void __free_pages_ok(struct page *page, unsigned int order)
1245 unsigned long flags;
1247 unsigned long pfn = page_to_pfn(page);
1249 if (!free_pages_prepare(page, order, true))
1252 migratetype = get_pfnblock_migratetype(page, pfn);
1253 local_irq_save(flags);
1254 __count_vm_events(PGFREE, 1 << order);
1255 free_one_page(page_zone(page), page, pfn, order, migratetype);
1256 local_irq_restore(flags);
1259 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1261 unsigned int nr_pages = 1 << order;
1262 struct page *p = page;
1266 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1268 __ClearPageReserved(p);
1269 set_page_count(p, 0);
1271 __ClearPageReserved(p);
1272 set_page_count(p, 0);
1274 page_zone(page)->managed_pages += nr_pages;
1275 set_page_refcounted(page);
1276 __free_pages(page, order);
1279 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1280 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1282 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1284 int __meminit early_pfn_to_nid(unsigned long pfn)
1286 static DEFINE_SPINLOCK(early_pfn_lock);
1289 spin_lock(&early_pfn_lock);
1290 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1292 nid = first_online_node;
1293 spin_unlock(&early_pfn_lock);
1299 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1300 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1301 struct mminit_pfnnid_cache *state)
1305 nid = __early_pfn_to_nid(pfn, state);
1306 if (nid >= 0 && nid != node)
1311 /* Only safe to use early in boot when initialisation is single-threaded */
1312 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1314 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1319 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1323 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1324 struct mminit_pfnnid_cache *state)
1331 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1334 if (early_page_uninitialised(pfn))
1336 return __free_pages_boot_core(page, order);
1340 * Check that the whole (or subset of) a pageblock given by the interval of
1341 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1342 * with the migration of free compaction scanner. The scanners then need to
1343 * use only pfn_valid_within() check for arches that allow holes within
1346 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1348 * It's possible on some configurations to have a setup like node0 node1 node0
1349 * i.e. it's possible that all pages within a zones range of pages do not
1350 * belong to a single zone. We assume that a border between node0 and node1
1351 * can occur within a single pageblock, but not a node0 node1 node0
1352 * interleaving within a single pageblock. It is therefore sufficient to check
1353 * the first and last page of a pageblock and avoid checking each individual
1354 * page in a pageblock.
1356 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1357 unsigned long end_pfn, struct zone *zone)
1359 struct page *start_page;
1360 struct page *end_page;
1362 /* end_pfn is one past the range we are checking */
1365 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1368 start_page = pfn_to_online_page(start_pfn);
1372 if (page_zone(start_page) != zone)
1375 end_page = pfn_to_page(end_pfn);
1377 /* This gives a shorter code than deriving page_zone(end_page) */
1378 if (page_zone_id(start_page) != page_zone_id(end_page))
1384 void set_zone_contiguous(struct zone *zone)
1386 unsigned long block_start_pfn = zone->zone_start_pfn;
1387 unsigned long block_end_pfn;
1389 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1390 for (; block_start_pfn < zone_end_pfn(zone);
1391 block_start_pfn = block_end_pfn,
1392 block_end_pfn += pageblock_nr_pages) {
1394 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1396 if (!__pageblock_pfn_to_page(block_start_pfn,
1397 block_end_pfn, zone))
1401 /* We confirm that there is no hole */
1402 zone->contiguous = true;
1405 void clear_zone_contiguous(struct zone *zone)
1407 zone->contiguous = false;
1410 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1411 static void __init deferred_free_range(struct page *page,
1412 unsigned long pfn, int nr_pages)
1419 /* Free a large naturally-aligned chunk if possible */
1420 if (nr_pages == pageblock_nr_pages &&
1421 (pfn & (pageblock_nr_pages - 1)) == 0) {
1422 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1423 __free_pages_boot_core(page, pageblock_order);
1427 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1428 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1429 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1430 __free_pages_boot_core(page, 0);
1434 /* Completion tracking for deferred_init_memmap() threads */
1435 static atomic_t pgdat_init_n_undone __initdata;
1436 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1438 static inline void __init pgdat_init_report_one_done(void)
1440 if (atomic_dec_and_test(&pgdat_init_n_undone))
1441 complete(&pgdat_init_all_done_comp);
1444 /* Initialise remaining memory on a node */
1445 static int __init deferred_init_memmap(void *data)
1447 pg_data_t *pgdat = data;
1448 int nid = pgdat->node_id;
1449 struct mminit_pfnnid_cache nid_init_state = { };
1450 unsigned long start = jiffies;
1451 unsigned long nr_pages = 0;
1452 unsigned long walk_start, walk_end;
1455 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1456 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1458 if (first_init_pfn == ULONG_MAX) {
1459 pgdat_init_report_one_done();
1463 /* Bind memory initialisation thread to a local node if possible */
1464 if (!cpumask_empty(cpumask))
1465 set_cpus_allowed_ptr(current, cpumask);
1467 /* Sanity check boundaries */
1468 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1469 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1470 pgdat->first_deferred_pfn = ULONG_MAX;
1472 /* Only the highest zone is deferred so find it */
1473 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1474 zone = pgdat->node_zones + zid;
1475 if (first_init_pfn < zone_end_pfn(zone))
1479 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1480 unsigned long pfn, end_pfn;
1481 struct page *page = NULL;
1482 struct page *free_base_page = NULL;
1483 unsigned long free_base_pfn = 0;
1486 end_pfn = min(walk_end, zone_end_pfn(zone));
1487 pfn = first_init_pfn;
1488 if (pfn < walk_start)
1490 if (pfn < zone->zone_start_pfn)
1491 pfn = zone->zone_start_pfn;
1493 for (; pfn < end_pfn; pfn++) {
1494 if (!pfn_valid_within(pfn))
1498 * Ensure pfn_valid is checked every
1499 * pageblock_nr_pages for memory holes
1501 if ((pfn & (pageblock_nr_pages - 1)) == 0) {
1502 if (!pfn_valid(pfn)) {
1508 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1513 /* Minimise pfn page lookups and scheduler checks */
1514 if (page && (pfn & (pageblock_nr_pages - 1)) != 0) {
1517 nr_pages += nr_to_free;
1518 deferred_free_range(free_base_page,
1519 free_base_pfn, nr_to_free);
1520 free_base_page = NULL;
1521 free_base_pfn = nr_to_free = 0;
1523 page = pfn_to_page(pfn);
1528 VM_BUG_ON(page_zone(page) != zone);
1532 __init_single_page(page, pfn, zid, nid);
1533 if (!free_base_page) {
1534 free_base_page = page;
1535 free_base_pfn = pfn;
1540 /* Where possible, batch up pages for a single free */
1543 /* Free the current block of pages to allocator */
1544 nr_pages += nr_to_free;
1545 deferred_free_range(free_base_page, free_base_pfn,
1547 free_base_page = NULL;
1548 free_base_pfn = nr_to_free = 0;
1550 /* Free the last block of pages to allocator */
1551 nr_pages += nr_to_free;
1552 deferred_free_range(free_base_page, free_base_pfn, nr_to_free);
1554 first_init_pfn = max(end_pfn, first_init_pfn);
1557 /* Sanity check that the next zone really is unpopulated */
1558 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1560 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1561 jiffies_to_msecs(jiffies - start));
1563 pgdat_init_report_one_done();
1566 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1568 void __init page_alloc_init_late(void)
1572 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1575 /* There will be num_node_state(N_MEMORY) threads */
1576 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1577 for_each_node_state(nid, N_MEMORY) {
1578 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1581 /* Block until all are initialised */
1582 wait_for_completion(&pgdat_init_all_done_comp);
1584 /* Reinit limits that are based on free pages after the kernel is up */
1585 files_maxfiles_init();
1588 for_each_populated_zone(zone)
1589 set_zone_contiguous(zone);
1593 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1594 void __init init_cma_reserved_pageblock(struct page *page)
1596 unsigned i = pageblock_nr_pages;
1597 struct page *p = page;
1600 __ClearPageReserved(p);
1601 set_page_count(p, 0);
1604 set_pageblock_migratetype(page, MIGRATE_CMA);
1606 if (pageblock_order >= MAX_ORDER) {
1607 i = pageblock_nr_pages;
1610 set_page_refcounted(p);
1611 __free_pages(p, MAX_ORDER - 1);
1612 p += MAX_ORDER_NR_PAGES;
1613 } while (i -= MAX_ORDER_NR_PAGES);
1615 set_page_refcounted(page);
1616 __free_pages(page, pageblock_order);
1619 adjust_managed_page_count(page, pageblock_nr_pages);
1624 * The order of subdivision here is critical for the IO subsystem.
1625 * Please do not alter this order without good reasons and regression
1626 * testing. Specifically, as large blocks of memory are subdivided,
1627 * the order in which smaller blocks are delivered depends on the order
1628 * they're subdivided in this function. This is the primary factor
1629 * influencing the order in which pages are delivered to the IO
1630 * subsystem according to empirical testing, and this is also justified
1631 * by considering the behavior of a buddy system containing a single
1632 * large block of memory acted on by a series of small allocations.
1633 * This behavior is a critical factor in sglist merging's success.
1637 static inline void expand(struct zone *zone, struct page *page,
1638 int low, int high, struct free_area *area,
1641 unsigned long size = 1 << high;
1643 while (high > low) {
1647 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1650 * Mark as guard pages (or page), that will allow to
1651 * merge back to allocator when buddy will be freed.
1652 * Corresponding page table entries will not be touched,
1653 * pages will stay not present in virtual address space
1655 if (set_page_guard(zone, &page[size], high, migratetype))
1658 list_add(&page[size].lru, &area->free_list[migratetype]);
1660 set_page_order(&page[size], high);
1664 static void check_new_page_bad(struct page *page)
1666 const char *bad_reason = NULL;
1667 unsigned long bad_flags = 0;
1669 if (unlikely(atomic_read(&page->_mapcount) != -1))
1670 bad_reason = "nonzero mapcount";
1671 if (unlikely(page->mapping != NULL))
1672 bad_reason = "non-NULL mapping";
1673 if (unlikely(page_ref_count(page) != 0))
1674 bad_reason = "nonzero _count";
1675 if (unlikely(page->flags & __PG_HWPOISON)) {
1676 bad_reason = "HWPoisoned (hardware-corrupted)";
1677 bad_flags = __PG_HWPOISON;
1678 /* Don't complain about hwpoisoned pages */
1679 page_mapcount_reset(page); /* remove PageBuddy */
1682 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1683 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1684 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1687 if (unlikely(page->mem_cgroup))
1688 bad_reason = "page still charged to cgroup";
1690 bad_page(page, bad_reason, bad_flags);
1694 * This page is about to be returned from the page allocator
1696 static inline int check_new_page(struct page *page)
1698 if (likely(page_expected_state(page,
1699 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
1702 check_new_page_bad(page);
1706 static inline bool free_pages_prezeroed(void)
1708 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1709 page_poisoning_enabled();
1712 #ifdef CONFIG_DEBUG_VM
1713 static bool check_pcp_refill(struct page *page)
1718 static bool check_new_pcp(struct page *page)
1720 return check_new_page(page);
1723 static bool check_pcp_refill(struct page *page)
1725 return check_new_page(page);
1727 static bool check_new_pcp(struct page *page)
1731 #endif /* CONFIG_DEBUG_VM */
1733 static bool check_new_pages(struct page *page, unsigned int order)
1736 for (i = 0; i < (1 << order); i++) {
1737 struct page *p = page + i;
1739 if (unlikely(check_new_page(p)))
1746 inline void post_alloc_hook(struct page *page, unsigned int order,
1749 set_page_private(page, 0);
1750 set_page_refcounted(page);
1752 arch_alloc_page(page, order);
1753 kernel_map_pages(page, 1 << order, 1);
1754 kernel_poison_pages(page, 1 << order, 1);
1755 kasan_alloc_pages(page, order);
1756 set_page_owner(page, order, gfp_flags);
1759 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1760 unsigned int alloc_flags)
1764 post_alloc_hook(page, order, gfp_flags);
1766 if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO))
1767 for (i = 0; i < (1 << order); i++)
1768 clear_highpage(page + i);
1770 if (order && (gfp_flags & __GFP_COMP))
1771 prep_compound_page(page, order);
1774 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1775 * allocate the page. The expectation is that the caller is taking
1776 * steps that will free more memory. The caller should avoid the page
1777 * being used for !PFMEMALLOC purposes.
1779 if (alloc_flags & ALLOC_NO_WATERMARKS)
1780 set_page_pfmemalloc(page);
1782 clear_page_pfmemalloc(page);
1786 * Go through the free lists for the given migratetype and remove
1787 * the smallest available page from the freelists
1790 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1793 unsigned int current_order;
1794 struct free_area *area;
1797 /* Find a page of the appropriate size in the preferred list */
1798 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1799 area = &(zone->free_area[current_order]);
1800 page = list_first_entry_or_null(&area->free_list[migratetype],
1804 list_del(&page->lru);
1805 rmv_page_order(page);
1807 expand(zone, page, order, current_order, area, migratetype);
1808 set_pcppage_migratetype(page, migratetype);
1817 * This array describes the order lists are fallen back to when
1818 * the free lists for the desirable migrate type are depleted
1820 static int fallbacks[MIGRATE_TYPES][4] = {
1821 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1822 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1823 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1825 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1827 #ifdef CONFIG_MEMORY_ISOLATION
1828 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1833 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1836 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1839 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1840 unsigned int order) { return NULL; }
1844 * Move the free pages in a range to the free lists of the requested type.
1845 * Note that start_page and end_pages are not aligned on a pageblock
1846 * boundary. If alignment is required, use move_freepages_block()
1848 static int move_freepages(struct zone *zone,
1849 struct page *start_page, struct page *end_page,
1850 int migratetype, int *num_movable)
1854 int pages_moved = 0;
1856 #ifndef CONFIG_HOLES_IN_ZONE
1858 * page_zone is not safe to call in this context when
1859 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1860 * anyway as we check zone boundaries in move_freepages_block().
1861 * Remove at a later date when no bug reports exist related to
1862 * grouping pages by mobility
1864 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1870 for (page = start_page; page <= end_page;) {
1871 if (!pfn_valid_within(page_to_pfn(page))) {
1876 /* Make sure we are not inadvertently changing nodes */
1877 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1879 if (!PageBuddy(page)) {
1881 * We assume that pages that could be isolated for
1882 * migration are movable. But we don't actually try
1883 * isolating, as that would be expensive.
1886 (PageLRU(page) || __PageMovable(page)))
1893 order = page_order(page);
1894 list_move(&page->lru,
1895 &zone->free_area[order].free_list[migratetype]);
1897 pages_moved += 1 << order;
1903 int move_freepages_block(struct zone *zone, struct page *page,
1904 int migratetype, int *num_movable)
1906 unsigned long start_pfn, end_pfn;
1907 struct page *start_page, *end_page;
1909 start_pfn = page_to_pfn(page);
1910 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1911 start_page = pfn_to_page(start_pfn);
1912 end_page = start_page + pageblock_nr_pages - 1;
1913 end_pfn = start_pfn + pageblock_nr_pages - 1;
1915 /* Do not cross zone boundaries */
1916 if (!zone_spans_pfn(zone, start_pfn))
1918 if (!zone_spans_pfn(zone, end_pfn))
1921 return move_freepages(zone, start_page, end_page, migratetype,
1925 static void change_pageblock_range(struct page *pageblock_page,
1926 int start_order, int migratetype)
1928 int nr_pageblocks = 1 << (start_order - pageblock_order);
1930 while (nr_pageblocks--) {
1931 set_pageblock_migratetype(pageblock_page, migratetype);
1932 pageblock_page += pageblock_nr_pages;
1937 * When we are falling back to another migratetype during allocation, try to
1938 * steal extra free pages from the same pageblocks to satisfy further
1939 * allocations, instead of polluting multiple pageblocks.
1941 * If we are stealing a relatively large buddy page, it is likely there will
1942 * be more free pages in the pageblock, so try to steal them all. For
1943 * reclaimable and unmovable allocations, we steal regardless of page size,
1944 * as fragmentation caused by those allocations polluting movable pageblocks
1945 * is worse than movable allocations stealing from unmovable and reclaimable
1948 static bool can_steal_fallback(unsigned int order, int start_mt)
1951 * Leaving this order check is intended, although there is
1952 * relaxed order check in next check. The reason is that
1953 * we can actually steal whole pageblock if this condition met,
1954 * but, below check doesn't guarantee it and that is just heuristic
1955 * so could be changed anytime.
1957 if (order >= pageblock_order)
1960 if (order >= pageblock_order / 2 ||
1961 start_mt == MIGRATE_RECLAIMABLE ||
1962 start_mt == MIGRATE_UNMOVABLE ||
1963 page_group_by_mobility_disabled)
1970 * This function implements actual steal behaviour. If order is large enough,
1971 * we can steal whole pageblock. If not, we first move freepages in this
1972 * pageblock to our migratetype and determine how many already-allocated pages
1973 * are there in the pageblock with a compatible migratetype. If at least half
1974 * of pages are free or compatible, we can change migratetype of the pageblock
1975 * itself, so pages freed in the future will be put on the correct free list.
1977 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1978 int start_type, bool whole_block)
1980 unsigned int current_order = page_order(page);
1981 struct free_area *area;
1982 int free_pages, movable_pages, alike_pages;
1985 old_block_type = get_pageblock_migratetype(page);
1988 * This can happen due to races and we want to prevent broken
1989 * highatomic accounting.
1991 if (is_migrate_highatomic(old_block_type))
1994 /* Take ownership for orders >= pageblock_order */
1995 if (current_order >= pageblock_order) {
1996 change_pageblock_range(page, current_order, start_type);
2000 /* We are not allowed to try stealing from the whole block */
2004 free_pages = move_freepages_block(zone, page, start_type,
2007 * Determine how many pages are compatible with our allocation.
2008 * For movable allocation, it's the number of movable pages which
2009 * we just obtained. For other types it's a bit more tricky.
2011 if (start_type == MIGRATE_MOVABLE) {
2012 alike_pages = movable_pages;
2015 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2016 * to MOVABLE pageblock, consider all non-movable pages as
2017 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2018 * vice versa, be conservative since we can't distinguish the
2019 * exact migratetype of non-movable pages.
2021 if (old_block_type == MIGRATE_MOVABLE)
2022 alike_pages = pageblock_nr_pages
2023 - (free_pages + movable_pages);
2028 /* moving whole block can fail due to zone boundary conditions */
2033 * If a sufficient number of pages in the block are either free or of
2034 * comparable migratability as our allocation, claim the whole block.
2036 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2037 page_group_by_mobility_disabled)
2038 set_pageblock_migratetype(page, start_type);
2043 area = &zone->free_area[current_order];
2044 list_move(&page->lru, &area->free_list[start_type]);
2048 * Check whether there is a suitable fallback freepage with requested order.
2049 * If only_stealable is true, this function returns fallback_mt only if
2050 * we can steal other freepages all together. This would help to reduce
2051 * fragmentation due to mixed migratetype pages in one pageblock.
2053 int find_suitable_fallback(struct free_area *area, unsigned int order,
2054 int migratetype, bool only_stealable, bool *can_steal)
2059 if (area->nr_free == 0)
2064 fallback_mt = fallbacks[migratetype][i];
2065 if (fallback_mt == MIGRATE_TYPES)
2068 if (list_empty(&area->free_list[fallback_mt]))
2071 if (can_steal_fallback(order, migratetype))
2074 if (!only_stealable)
2085 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2086 * there are no empty page blocks that contain a page with a suitable order
2088 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2089 unsigned int alloc_order)
2092 unsigned long max_managed, flags;
2095 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2096 * Check is race-prone but harmless.
2098 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2099 if (zone->nr_reserved_highatomic >= max_managed)
2102 spin_lock_irqsave(&zone->lock, flags);
2104 /* Recheck the nr_reserved_highatomic limit under the lock */
2105 if (zone->nr_reserved_highatomic >= max_managed)
2109 mt = get_pageblock_migratetype(page);
2110 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2111 && !is_migrate_cma(mt)) {
2112 zone->nr_reserved_highatomic += pageblock_nr_pages;
2113 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2114 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2118 spin_unlock_irqrestore(&zone->lock, flags);
2122 * Used when an allocation is about to fail under memory pressure. This
2123 * potentially hurts the reliability of high-order allocations when under
2124 * intense memory pressure but failed atomic allocations should be easier
2125 * to recover from than an OOM.
2127 * If @force is true, try to unreserve a pageblock even though highatomic
2128 * pageblock is exhausted.
2130 static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2133 struct zonelist *zonelist = ac->zonelist;
2134 unsigned long flags;
2141 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2144 * Preserve at least one pageblock unless memory pressure
2147 if (!force && zone->nr_reserved_highatomic <=
2151 spin_lock_irqsave(&zone->lock, flags);
2152 for (order = 0; order < MAX_ORDER; order++) {
2153 struct free_area *area = &(zone->free_area[order]);
2155 page = list_first_entry_or_null(
2156 &area->free_list[MIGRATE_HIGHATOMIC],
2162 * In page freeing path, migratetype change is racy so
2163 * we can counter several free pages in a pageblock
2164 * in this loop althoug we changed the pageblock type
2165 * from highatomic to ac->migratetype. So we should
2166 * adjust the count once.
2168 if (is_migrate_highatomic_page(page)) {
2170 * It should never happen but changes to
2171 * locking could inadvertently allow a per-cpu
2172 * drain to add pages to MIGRATE_HIGHATOMIC
2173 * while unreserving so be safe and watch for
2176 zone->nr_reserved_highatomic -= min(
2178 zone->nr_reserved_highatomic);
2182 * Convert to ac->migratetype and avoid the normal
2183 * pageblock stealing heuristics. Minimally, the caller
2184 * is doing the work and needs the pages. More
2185 * importantly, if the block was always converted to
2186 * MIGRATE_UNMOVABLE or another type then the number
2187 * of pageblocks that cannot be completely freed
2190 set_pageblock_migratetype(page, ac->migratetype);
2191 ret = move_freepages_block(zone, page, ac->migratetype,
2194 spin_unlock_irqrestore(&zone->lock, flags);
2198 spin_unlock_irqrestore(&zone->lock, flags);
2205 * Try finding a free buddy page on the fallback list and put it on the free
2206 * list of requested migratetype, possibly along with other pages from the same
2207 * block, depending on fragmentation avoidance heuristics. Returns true if
2208 * fallback was found so that __rmqueue_smallest() can grab it.
2211 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
2213 struct free_area *area;
2214 unsigned int current_order;
2219 /* Find the largest possible block of pages in the other list */
2220 for (current_order = MAX_ORDER-1;
2221 current_order >= order && current_order <= MAX_ORDER-1;
2223 area = &(zone->free_area[current_order]);
2224 fallback_mt = find_suitable_fallback(area, current_order,
2225 start_migratetype, false, &can_steal);
2226 if (fallback_mt == -1)
2229 page = list_first_entry(&area->free_list[fallback_mt],
2232 steal_suitable_fallback(zone, page, start_migratetype,
2235 trace_mm_page_alloc_extfrag(page, order, current_order,
2236 start_migratetype, fallback_mt);
2245 * Do the hard work of removing an element from the buddy allocator.
2246 * Call me with the zone->lock already held.
2248 static struct page *__rmqueue(struct zone *zone, unsigned int order,
2254 page = __rmqueue_smallest(zone, order, migratetype);
2255 if (unlikely(!page)) {
2256 if (migratetype == MIGRATE_MOVABLE)
2257 page = __rmqueue_cma_fallback(zone, order);
2259 if (!page && __rmqueue_fallback(zone, order, migratetype))
2263 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2268 * Obtain a specified number of elements from the buddy allocator, all under
2269 * a single hold of the lock, for efficiency. Add them to the supplied list.
2270 * Returns the number of new pages which were placed at *list.
2272 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2273 unsigned long count, struct list_head *list,
2274 int migratetype, bool cold)
2278 spin_lock(&zone->lock);
2279 for (i = 0; i < count; ++i) {
2280 struct page *page = __rmqueue(zone, order, migratetype);
2281 if (unlikely(page == NULL))
2284 if (unlikely(check_pcp_refill(page)))
2288 * Split buddy pages returned by expand() are received here
2289 * in physical page order. The page is added to the callers and
2290 * list and the list head then moves forward. From the callers
2291 * perspective, the linked list is ordered by page number in
2292 * some conditions. This is useful for IO devices that can
2293 * merge IO requests if the physical pages are ordered
2297 list_add(&page->lru, list);
2299 list_add_tail(&page->lru, list);
2302 if (is_migrate_cma(get_pcppage_migratetype(page)))
2303 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2308 * i pages were removed from the buddy list even if some leak due
2309 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2310 * on i. Do not confuse with 'alloced' which is the number of
2311 * pages added to the pcp list.
2313 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2314 spin_unlock(&zone->lock);
2320 * Called from the vmstat counter updater to drain pagesets of this
2321 * currently executing processor on remote nodes after they have
2324 * Note that this function must be called with the thread pinned to
2325 * a single processor.
2327 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2329 unsigned long flags;
2330 int to_drain, batch;
2332 local_irq_save(flags);
2333 batch = READ_ONCE(pcp->batch);
2334 to_drain = min(pcp->count, batch);
2336 free_pcppages_bulk(zone, to_drain, pcp);
2337 pcp->count -= to_drain;
2339 local_irq_restore(flags);
2344 * Drain pcplists of the indicated processor and zone.
2346 * The processor must either be the current processor and the
2347 * thread pinned to the current processor or a processor that
2350 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2352 unsigned long flags;
2353 struct per_cpu_pageset *pset;
2354 struct per_cpu_pages *pcp;
2356 local_irq_save(flags);
2357 pset = per_cpu_ptr(zone->pageset, cpu);
2361 free_pcppages_bulk(zone, pcp->count, pcp);
2364 local_irq_restore(flags);
2368 * Drain pcplists of all zones on the indicated processor.
2370 * The processor must either be the current processor and the
2371 * thread pinned to the current processor or a processor that
2374 static void drain_pages(unsigned int cpu)
2378 for_each_populated_zone(zone) {
2379 drain_pages_zone(cpu, zone);
2384 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2386 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2387 * the single zone's pages.
2389 void drain_local_pages(struct zone *zone)
2391 int cpu = smp_processor_id();
2394 drain_pages_zone(cpu, zone);
2399 static void drain_local_pages_wq(struct work_struct *work)
2402 * drain_all_pages doesn't use proper cpu hotplug protection so
2403 * we can race with cpu offline when the WQ can move this from
2404 * a cpu pinned worker to an unbound one. We can operate on a different
2405 * cpu which is allright but we also have to make sure to not move to
2409 drain_local_pages(NULL);
2414 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2416 * When zone parameter is non-NULL, spill just the single zone's pages.
2418 * Note that this can be extremely slow as the draining happens in a workqueue.
2420 void drain_all_pages(struct zone *zone)
2425 * Allocate in the BSS so we wont require allocation in
2426 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2428 static cpumask_t cpus_with_pcps;
2431 * Make sure nobody triggers this path before mm_percpu_wq is fully
2434 if (WARN_ON_ONCE(!mm_percpu_wq))
2437 /* Workqueues cannot recurse */
2438 if (current->flags & PF_WQ_WORKER)
2442 * Do not drain if one is already in progress unless it's specific to
2443 * a zone. Such callers are primarily CMA and memory hotplug and need
2444 * the drain to be complete when the call returns.
2446 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
2449 mutex_lock(&pcpu_drain_mutex);
2453 * We don't care about racing with CPU hotplug event
2454 * as offline notification will cause the notified
2455 * cpu to drain that CPU pcps and on_each_cpu_mask
2456 * disables preemption as part of its processing
2458 for_each_online_cpu(cpu) {
2459 struct per_cpu_pageset *pcp;
2461 bool has_pcps = false;
2464 pcp = per_cpu_ptr(zone->pageset, cpu);
2468 for_each_populated_zone(z) {
2469 pcp = per_cpu_ptr(z->pageset, cpu);
2470 if (pcp->pcp.count) {
2478 cpumask_set_cpu(cpu, &cpus_with_pcps);
2480 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2483 for_each_cpu(cpu, &cpus_with_pcps) {
2484 struct work_struct *work = per_cpu_ptr(&pcpu_drain, cpu);
2485 INIT_WORK(work, drain_local_pages_wq);
2486 queue_work_on(cpu, mm_percpu_wq, work);
2488 for_each_cpu(cpu, &cpus_with_pcps)
2489 flush_work(per_cpu_ptr(&pcpu_drain, cpu));
2491 mutex_unlock(&pcpu_drain_mutex);
2494 #ifdef CONFIG_HIBERNATION
2496 void mark_free_pages(struct zone *zone)
2498 unsigned long pfn, max_zone_pfn;
2499 unsigned long flags;
2500 unsigned int order, t;
2503 if (zone_is_empty(zone))
2506 spin_lock_irqsave(&zone->lock, flags);
2508 max_zone_pfn = zone_end_pfn(zone);
2509 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2510 if (pfn_valid(pfn)) {
2511 page = pfn_to_page(pfn);
2513 if (page_zone(page) != zone)
2516 if (!swsusp_page_is_forbidden(page))
2517 swsusp_unset_page_free(page);
2520 for_each_migratetype_order(order, t) {
2521 list_for_each_entry(page,
2522 &zone->free_area[order].free_list[t], lru) {
2525 pfn = page_to_pfn(page);
2526 for (i = 0; i < (1UL << order); i++)
2527 swsusp_set_page_free(pfn_to_page(pfn + i));
2530 spin_unlock_irqrestore(&zone->lock, flags);
2532 #endif /* CONFIG_PM */
2535 * Free a 0-order page
2536 * cold == true ? free a cold page : free a hot page
2538 void free_hot_cold_page(struct page *page, bool cold)
2540 struct zone *zone = page_zone(page);
2541 struct per_cpu_pages *pcp;
2542 unsigned long flags;
2543 unsigned long pfn = page_to_pfn(page);
2546 if (!free_pcp_prepare(page))
2549 migratetype = get_pfnblock_migratetype(page, pfn);
2550 set_pcppage_migratetype(page, migratetype);
2551 local_irq_save(flags);
2552 __count_vm_event(PGFREE);
2555 * We only track unmovable, reclaimable and movable on pcp lists.
2556 * Free ISOLATE pages back to the allocator because they are being
2557 * offlined but treat HIGHATOMIC as movable pages so we can get those
2558 * areas back if necessary. Otherwise, we may have to free
2559 * excessively into the page allocator
2561 if (migratetype >= MIGRATE_PCPTYPES) {
2562 if (unlikely(is_migrate_isolate(migratetype))) {
2563 free_one_page(zone, page, pfn, 0, migratetype);
2566 migratetype = MIGRATE_MOVABLE;
2569 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2571 list_add(&page->lru, &pcp->lists[migratetype]);
2573 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2575 if (pcp->count >= pcp->high) {
2576 unsigned long batch = READ_ONCE(pcp->batch);
2577 free_pcppages_bulk(zone, batch, pcp);
2578 pcp->count -= batch;
2582 local_irq_restore(flags);
2586 * Free a list of 0-order pages
2588 void free_hot_cold_page_list(struct list_head *list, bool cold)
2590 struct page *page, *next;
2592 list_for_each_entry_safe(page, next, list, lru) {
2593 trace_mm_page_free_batched(page, cold);
2594 free_hot_cold_page(page, cold);
2599 * split_page takes a non-compound higher-order page, and splits it into
2600 * n (1<<order) sub-pages: page[0..n]
2601 * Each sub-page must be freed individually.
2603 * Note: this is probably too low level an operation for use in drivers.
2604 * Please consult with lkml before using this in your driver.
2606 void split_page(struct page *page, unsigned int order)
2610 VM_BUG_ON_PAGE(PageCompound(page), page);
2611 VM_BUG_ON_PAGE(!page_count(page), page);
2613 #ifdef CONFIG_KMEMCHECK
2615 * Split shadow pages too, because free(page[0]) would
2616 * otherwise free the whole shadow.
2618 if (kmemcheck_page_is_tracked(page))
2619 split_page(virt_to_page(page[0].shadow), order);
2622 for (i = 1; i < (1 << order); i++)
2623 set_page_refcounted(page + i);
2624 split_page_owner(page, order);
2626 EXPORT_SYMBOL_GPL(split_page);
2628 int __isolate_free_page(struct page *page, unsigned int order)
2630 unsigned long watermark;
2634 BUG_ON(!PageBuddy(page));
2636 zone = page_zone(page);
2637 mt = get_pageblock_migratetype(page);
2639 if (!is_migrate_isolate(mt)) {
2641 * Obey watermarks as if the page was being allocated. We can
2642 * emulate a high-order watermark check with a raised order-0
2643 * watermark, because we already know our high-order page
2646 watermark = min_wmark_pages(zone) + (1UL << order);
2647 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
2650 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2653 /* Remove page from free list */
2654 list_del(&page->lru);
2655 zone->free_area[order].nr_free--;
2656 rmv_page_order(page);
2659 * Set the pageblock if the isolated page is at least half of a
2662 if (order >= pageblock_order - 1) {
2663 struct page *endpage = page + (1 << order) - 1;
2664 for (; page < endpage; page += pageblock_nr_pages) {
2665 int mt = get_pageblock_migratetype(page);
2666 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
2667 && !is_migrate_highatomic(mt))
2668 set_pageblock_migratetype(page,
2674 return 1UL << order;
2678 * Update NUMA hit/miss statistics
2680 * Must be called with interrupts disabled.
2682 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
2685 enum zone_stat_item local_stat = NUMA_LOCAL;
2687 if (z->node != numa_node_id())
2688 local_stat = NUMA_OTHER;
2690 if (z->node == preferred_zone->node)
2691 __inc_zone_state(z, NUMA_HIT);
2693 __inc_zone_state(z, NUMA_MISS);
2694 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2696 __inc_zone_state(z, local_stat);
2700 /* Remove page from the per-cpu list, caller must protect the list */
2701 static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
2702 bool cold, struct per_cpu_pages *pcp,
2703 struct list_head *list)
2708 if (list_empty(list)) {
2709 pcp->count += rmqueue_bulk(zone, 0,
2712 if (unlikely(list_empty(list)))
2717 page = list_last_entry(list, struct page, lru);
2719 page = list_first_entry(list, struct page, lru);
2721 list_del(&page->lru);
2723 } while (check_new_pcp(page));
2728 /* Lock and remove page from the per-cpu list */
2729 static struct page *rmqueue_pcplist(struct zone *preferred_zone,
2730 struct zone *zone, unsigned int order,
2731 gfp_t gfp_flags, int migratetype)
2733 struct per_cpu_pages *pcp;
2734 struct list_head *list;
2735 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2737 unsigned long flags;
2739 local_irq_save(flags);
2740 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2741 list = &pcp->lists[migratetype];
2742 page = __rmqueue_pcplist(zone, migratetype, cold, pcp, list);
2744 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
2745 zone_statistics(preferred_zone, zone);
2747 local_irq_restore(flags);
2752 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2755 struct page *rmqueue(struct zone *preferred_zone,
2756 struct zone *zone, unsigned int order,
2757 gfp_t gfp_flags, unsigned int alloc_flags,
2760 unsigned long flags;
2763 if (likely(order == 0)) {
2764 page = rmqueue_pcplist(preferred_zone, zone, order,
2765 gfp_flags, migratetype);
2770 * We most definitely don't want callers attempting to
2771 * allocate greater than order-1 page units with __GFP_NOFAIL.
2773 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2774 spin_lock_irqsave(&zone->lock, flags);
2778 if (alloc_flags & ALLOC_HARDER) {
2779 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2781 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2784 page = __rmqueue(zone, order, migratetype);
2785 } while (page && check_new_pages(page, order));
2786 spin_unlock(&zone->lock);
2789 __mod_zone_freepage_state(zone, -(1 << order),
2790 get_pcppage_migratetype(page));
2792 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
2793 zone_statistics(preferred_zone, zone);
2794 local_irq_restore(flags);
2797 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
2801 local_irq_restore(flags);
2805 #ifdef CONFIG_FAIL_PAGE_ALLOC
2808 struct fault_attr attr;
2810 bool ignore_gfp_highmem;
2811 bool ignore_gfp_reclaim;
2813 } fail_page_alloc = {
2814 .attr = FAULT_ATTR_INITIALIZER,
2815 .ignore_gfp_reclaim = true,
2816 .ignore_gfp_highmem = true,
2820 static int __init setup_fail_page_alloc(char *str)
2822 return setup_fault_attr(&fail_page_alloc.attr, str);
2824 __setup("fail_page_alloc=", setup_fail_page_alloc);
2826 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2828 if (order < fail_page_alloc.min_order)
2830 if (gfp_mask & __GFP_NOFAIL)
2832 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2834 if (fail_page_alloc.ignore_gfp_reclaim &&
2835 (gfp_mask & __GFP_DIRECT_RECLAIM))
2838 return should_fail(&fail_page_alloc.attr, 1 << order);
2841 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2843 static int __init fail_page_alloc_debugfs(void)
2845 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2848 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2849 &fail_page_alloc.attr);
2851 return PTR_ERR(dir);
2853 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2854 &fail_page_alloc.ignore_gfp_reclaim))
2856 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2857 &fail_page_alloc.ignore_gfp_highmem))
2859 if (!debugfs_create_u32("min-order", mode, dir,
2860 &fail_page_alloc.min_order))
2865 debugfs_remove_recursive(dir);
2870 late_initcall(fail_page_alloc_debugfs);
2872 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2874 #else /* CONFIG_FAIL_PAGE_ALLOC */
2876 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2881 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2884 * Return true if free base pages are above 'mark'. For high-order checks it
2885 * will return true of the order-0 watermark is reached and there is at least
2886 * one free page of a suitable size. Checking now avoids taking the zone lock
2887 * to check in the allocation paths if no pages are free.
2889 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2890 int classzone_idx, unsigned int alloc_flags,
2895 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2897 /* free_pages may go negative - that's OK */
2898 free_pages -= (1 << order) - 1;
2900 if (alloc_flags & ALLOC_HIGH)
2904 * If the caller does not have rights to ALLOC_HARDER then subtract
2905 * the high-atomic reserves. This will over-estimate the size of the
2906 * atomic reserve but it avoids a search.
2908 if (likely(!alloc_harder))
2909 free_pages -= z->nr_reserved_highatomic;
2914 /* If allocation can't use CMA areas don't use free CMA pages */
2915 if (!(alloc_flags & ALLOC_CMA))
2916 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2920 * Check watermarks for an order-0 allocation request. If these
2921 * are not met, then a high-order request also cannot go ahead
2922 * even if a suitable page happened to be free.
2924 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2927 /* If this is an order-0 request then the watermark is fine */
2931 /* For a high-order request, check at least one suitable page is free */
2932 for (o = order; o < MAX_ORDER; o++) {
2933 struct free_area *area = &z->free_area[o];
2942 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2943 if (!list_empty(&area->free_list[mt]))
2948 if ((alloc_flags & ALLOC_CMA) &&
2949 !list_empty(&area->free_list[MIGRATE_CMA])) {
2957 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2958 int classzone_idx, unsigned int alloc_flags)
2960 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2961 zone_page_state(z, NR_FREE_PAGES));
2964 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2965 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2967 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2971 /* If allocation can't use CMA areas don't use free CMA pages */
2972 if (!(alloc_flags & ALLOC_CMA))
2973 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2977 * Fast check for order-0 only. If this fails then the reserves
2978 * need to be calculated. There is a corner case where the check
2979 * passes but only the high-order atomic reserve are free. If
2980 * the caller is !atomic then it'll uselessly search the free
2981 * list. That corner case is then slower but it is harmless.
2983 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2986 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2990 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2991 unsigned long mark, int classzone_idx)
2993 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2995 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2996 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2998 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
3003 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3005 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3008 #else /* CONFIG_NUMA */
3009 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3013 #endif /* CONFIG_NUMA */
3016 * get_page_from_freelist goes through the zonelist trying to allocate
3019 static struct page *
3020 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
3021 const struct alloc_context *ac)
3023 struct zoneref *z = ac->preferred_zoneref;
3025 struct pglist_data *last_pgdat_dirty_limit = NULL;
3028 * Scan zonelist, looking for a zone with enough free.
3029 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3031 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3036 if (cpusets_enabled() &&
3037 (alloc_flags & ALLOC_CPUSET) &&
3038 !__cpuset_zone_allowed(zone, gfp_mask))
3041 * When allocating a page cache page for writing, we
3042 * want to get it from a node that is within its dirty
3043 * limit, such that no single node holds more than its
3044 * proportional share of globally allowed dirty pages.
3045 * The dirty limits take into account the node's
3046 * lowmem reserves and high watermark so that kswapd
3047 * should be able to balance it without having to
3048 * write pages from its LRU list.
3050 * XXX: For now, allow allocations to potentially
3051 * exceed the per-node dirty limit in the slowpath
3052 * (spread_dirty_pages unset) before going into reclaim,
3053 * which is important when on a NUMA setup the allowed
3054 * nodes are together not big enough to reach the
3055 * global limit. The proper fix for these situations
3056 * will require awareness of nodes in the
3057 * dirty-throttling and the flusher threads.
3059 if (ac->spread_dirty_pages) {
3060 if (last_pgdat_dirty_limit == zone->zone_pgdat)
3063 if (!node_dirty_ok(zone->zone_pgdat)) {
3064 last_pgdat_dirty_limit = zone->zone_pgdat;
3069 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
3070 if (!zone_watermark_fast(zone, order, mark,
3071 ac_classzone_idx(ac), alloc_flags)) {
3074 /* Checked here to keep the fast path fast */
3075 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
3076 if (alloc_flags & ALLOC_NO_WATERMARKS)
3079 if (node_reclaim_mode == 0 ||
3080 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
3083 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
3085 case NODE_RECLAIM_NOSCAN:
3088 case NODE_RECLAIM_FULL:
3089 /* scanned but unreclaimable */
3092 /* did we reclaim enough */
3093 if (zone_watermark_ok(zone, order, mark,
3094 ac_classzone_idx(ac), alloc_flags))
3102 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
3103 gfp_mask, alloc_flags, ac->migratetype);
3105 prep_new_page(page, order, gfp_mask, alloc_flags);
3108 * If this is a high-order atomic allocation then check
3109 * if the pageblock should be reserved for the future
3111 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3112 reserve_highatomic_pageblock(page, zone, order);
3122 * Large machines with many possible nodes should not always dump per-node
3123 * meminfo in irq context.
3125 static inline bool should_suppress_show_mem(void)
3130 ret = in_interrupt();
3135 static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
3137 unsigned int filter = SHOW_MEM_FILTER_NODES;
3138 static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1);
3140 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs))
3144 * This documents exceptions given to allocations in certain
3145 * contexts that are allowed to allocate outside current's set
3148 if (!(gfp_mask & __GFP_NOMEMALLOC))
3149 if (test_thread_flag(TIF_MEMDIE) ||
3150 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3151 filter &= ~SHOW_MEM_FILTER_NODES;
3152 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3153 filter &= ~SHOW_MEM_FILTER_NODES;
3155 show_mem(filter, nodemask);
3158 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
3160 struct va_format vaf;
3162 static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL,
3163 DEFAULT_RATELIMIT_BURST);
3165 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
3168 pr_warn("%s: ", current->comm);
3170 va_start(args, fmt);
3173 pr_cont("%pV", &vaf);
3176 pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask, &gfp_mask);
3178 pr_cont("%*pbl\n", nodemask_pr_args(nodemask));
3180 pr_cont("(null)\n");
3182 cpuset_print_current_mems_allowed();
3185 warn_alloc_show_mem(gfp_mask, nodemask);
3188 static inline struct page *
3189 __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
3190 unsigned int alloc_flags,
3191 const struct alloc_context *ac)
3195 page = get_page_from_freelist(gfp_mask, order,
3196 alloc_flags|ALLOC_CPUSET, ac);
3198 * fallback to ignore cpuset restriction if our nodes
3202 page = get_page_from_freelist(gfp_mask, order,
3208 static inline struct page *
3209 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3210 const struct alloc_context *ac, unsigned long *did_some_progress)
3212 struct oom_control oc = {
3213 .zonelist = ac->zonelist,
3214 .nodemask = ac->nodemask,
3216 .gfp_mask = gfp_mask,
3221 *did_some_progress = 0;
3224 * Acquire the oom lock. If that fails, somebody else is
3225 * making progress for us.
3227 if (!mutex_trylock(&oom_lock)) {
3228 *did_some_progress = 1;
3229 schedule_timeout_uninterruptible(1);
3234 * Go through the zonelist yet one more time, keep very high watermark
3235 * here, this is only to catch a parallel oom killing, we must fail if
3236 * we're still under heavy pressure.
3238 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3239 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3243 /* Coredumps can quickly deplete all memory reserves */
3244 if (current->flags & PF_DUMPCORE)
3246 /* The OOM killer will not help higher order allocs */
3247 if (order > PAGE_ALLOC_COSTLY_ORDER)
3249 /* The OOM killer does not needlessly kill tasks for lowmem */
3250 if (ac->high_zoneidx < ZONE_NORMAL)
3252 if (pm_suspended_storage())
3255 * XXX: GFP_NOFS allocations should rather fail than rely on
3256 * other request to make a forward progress.
3257 * We are in an unfortunate situation where out_of_memory cannot
3258 * do much for this context but let's try it to at least get
3259 * access to memory reserved if the current task is killed (see
3260 * out_of_memory). Once filesystems are ready to handle allocation
3261 * failures more gracefully we should just bail out here.
3264 /* The OOM killer may not free memory on a specific node */
3265 if (gfp_mask & __GFP_THISNODE)
3268 /* Exhausted what can be done so it's blamo time */
3269 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3270 *did_some_progress = 1;
3273 * Help non-failing allocations by giving them access to memory
3276 if (gfp_mask & __GFP_NOFAIL)
3277 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
3278 ALLOC_NO_WATERMARKS, ac);
3281 mutex_unlock(&oom_lock);
3286 * Maximum number of compaction retries wit a progress before OOM
3287 * killer is consider as the only way to move forward.
3289 #define MAX_COMPACT_RETRIES 16
3291 #ifdef CONFIG_COMPACTION
3292 /* Try memory compaction for high-order allocations before reclaim */
3293 static struct page *
3294 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3295 unsigned int alloc_flags, const struct alloc_context *ac,
3296 enum compact_priority prio, enum compact_result *compact_result)
3299 unsigned int noreclaim_flag;
3304 noreclaim_flag = memalloc_noreclaim_save();
3305 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3307 memalloc_noreclaim_restore(noreclaim_flag);
3309 if (*compact_result <= COMPACT_INACTIVE)
3313 * At least in one zone compaction wasn't deferred or skipped, so let's
3314 * count a compaction stall
3316 count_vm_event(COMPACTSTALL);
3318 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3321 struct zone *zone = page_zone(page);
3323 zone->compact_blockskip_flush = false;
3324 compaction_defer_reset(zone, order, true);
3325 count_vm_event(COMPACTSUCCESS);
3330 * It's bad if compaction run occurs and fails. The most likely reason
3331 * is that pages exist, but not enough to satisfy watermarks.
3333 count_vm_event(COMPACTFAIL);
3341 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3342 enum compact_result compact_result,
3343 enum compact_priority *compact_priority,
3344 int *compaction_retries)
3346 int max_retries = MAX_COMPACT_RETRIES;
3349 int retries = *compaction_retries;
3350 enum compact_priority priority = *compact_priority;
3355 if (compaction_made_progress(compact_result))
3356 (*compaction_retries)++;
3359 * compaction considers all the zone as desperately out of memory
3360 * so it doesn't really make much sense to retry except when the
3361 * failure could be caused by insufficient priority
3363 if (compaction_failed(compact_result))
3364 goto check_priority;
3367 * make sure the compaction wasn't deferred or didn't bail out early
3368 * due to locks contention before we declare that we should give up.
3369 * But do not retry if the given zonelist is not suitable for
3372 if (compaction_withdrawn(compact_result)) {
3373 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
3378 * !costly requests are much more important than __GFP_REPEAT
3379 * costly ones because they are de facto nofail and invoke OOM
3380 * killer to move on while costly can fail and users are ready
3381 * to cope with that. 1/4 retries is rather arbitrary but we
3382 * would need much more detailed feedback from compaction to
3383 * make a better decision.
3385 if (order > PAGE_ALLOC_COSTLY_ORDER)
3387 if (*compaction_retries <= max_retries) {
3393 * Make sure there are attempts at the highest priority if we exhausted
3394 * all retries or failed at the lower priorities.
3397 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
3398 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
3400 if (*compact_priority > min_priority) {
3401 (*compact_priority)--;
3402 *compaction_retries = 0;
3406 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
3410 static inline struct page *
3411 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3412 unsigned int alloc_flags, const struct alloc_context *ac,
3413 enum compact_priority prio, enum compact_result *compact_result)
3415 *compact_result = COMPACT_SKIPPED;
3420 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3421 enum compact_result compact_result,
3422 enum compact_priority *compact_priority,
3423 int *compaction_retries)
3428 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
3432 * There are setups with compaction disabled which would prefer to loop
3433 * inside the allocator rather than hit the oom killer prematurely.
3434 * Let's give them a good hope and keep retrying while the order-0
3435 * watermarks are OK.
3437 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3439 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
3440 ac_classzone_idx(ac), alloc_flags))
3445 #endif /* CONFIG_COMPACTION */
3447 /* Perform direct synchronous page reclaim */
3449 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3450 const struct alloc_context *ac)
3452 struct reclaim_state reclaim_state;
3454 unsigned int noreclaim_flag;
3458 /* We now go into synchronous reclaim */
3459 cpuset_memory_pressure_bump();
3460 noreclaim_flag = memalloc_noreclaim_save();
3461 lockdep_set_current_reclaim_state(gfp_mask);
3462 reclaim_state.reclaimed_slab = 0;
3463 current->reclaim_state = &reclaim_state;
3465 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3468 current->reclaim_state = NULL;
3469 lockdep_clear_current_reclaim_state();
3470 memalloc_noreclaim_restore(noreclaim_flag);
3477 /* The really slow allocator path where we enter direct reclaim */
3478 static inline struct page *
3479 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3480 unsigned int alloc_flags, const struct alloc_context *ac,
3481 unsigned long *did_some_progress)
3483 struct page *page = NULL;
3484 bool drained = false;
3486 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3487 if (unlikely(!(*did_some_progress)))
3491 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3494 * If an allocation failed after direct reclaim, it could be because
3495 * pages are pinned on the per-cpu lists or in high alloc reserves.
3496 * Shrink them them and try again
3498 if (!page && !drained) {
3499 unreserve_highatomic_pageblock(ac, false);
3500 drain_all_pages(NULL);
3508 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3512 pg_data_t *last_pgdat = NULL;
3514 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3515 ac->high_zoneidx, ac->nodemask) {
3516 if (last_pgdat != zone->zone_pgdat)
3517 wakeup_kswapd(zone, order, ac->high_zoneidx);
3518 last_pgdat = zone->zone_pgdat;
3522 static inline unsigned int
3523 gfp_to_alloc_flags(gfp_t gfp_mask)
3525 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3527 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3528 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3531 * The caller may dip into page reserves a bit more if the caller
3532 * cannot run direct reclaim, or if the caller has realtime scheduling
3533 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3534 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3536 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3538 if (gfp_mask & __GFP_ATOMIC) {
3540 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3541 * if it can't schedule.
3543 if (!(gfp_mask & __GFP_NOMEMALLOC))
3544 alloc_flags |= ALLOC_HARDER;
3546 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3547 * comment for __cpuset_node_allowed().
3549 alloc_flags &= ~ALLOC_CPUSET;
3550 } else if (unlikely(rt_task(current)) && !in_interrupt())
3551 alloc_flags |= ALLOC_HARDER;
3554 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3555 alloc_flags |= ALLOC_CMA;
3560 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3562 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
3565 if (gfp_mask & __GFP_MEMALLOC)
3567 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3569 if (!in_interrupt() &&
3570 ((current->flags & PF_MEMALLOC) ||
3571 unlikely(test_thread_flag(TIF_MEMDIE))))
3578 * Checks whether it makes sense to retry the reclaim to make a forward progress
3579 * for the given allocation request.
3581 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3582 * without success, or when we couldn't even meet the watermark if we
3583 * reclaimed all remaining pages on the LRU lists.
3585 * Returns true if a retry is viable or false to enter the oom path.
3588 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3589 struct alloc_context *ac, int alloc_flags,
3590 bool did_some_progress, int *no_progress_loops)
3596 * Costly allocations might have made a progress but this doesn't mean
3597 * their order will become available due to high fragmentation so
3598 * always increment the no progress counter for them
3600 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3601 *no_progress_loops = 0;
3603 (*no_progress_loops)++;
3606 * Make sure we converge to OOM if we cannot make any progress
3607 * several times in the row.
3609 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
3610 /* Before OOM, exhaust highatomic_reserve */
3611 return unreserve_highatomic_pageblock(ac, true);
3615 * Keep reclaiming pages while there is a chance this will lead
3616 * somewhere. If none of the target zones can satisfy our allocation
3617 * request even if all reclaimable pages are considered then we are
3618 * screwed and have to go OOM.
3620 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3622 unsigned long available;
3623 unsigned long reclaimable;
3624 unsigned long min_wmark = min_wmark_pages(zone);
3627 available = reclaimable = zone_reclaimable_pages(zone);
3628 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3631 * Would the allocation succeed if we reclaimed all
3632 * reclaimable pages?
3634 wmark = __zone_watermark_ok(zone, order, min_wmark,
3635 ac_classzone_idx(ac), alloc_flags, available);
3636 trace_reclaim_retry_zone(z, order, reclaimable,
3637 available, min_wmark, *no_progress_loops, wmark);
3640 * If we didn't make any progress and have a lot of
3641 * dirty + writeback pages then we should wait for
3642 * an IO to complete to slow down the reclaim and
3643 * prevent from pre mature OOM
3645 if (!did_some_progress) {
3646 unsigned long write_pending;
3648 write_pending = zone_page_state_snapshot(zone,
3649 NR_ZONE_WRITE_PENDING);
3651 if (2 * write_pending > reclaimable) {
3652 congestion_wait(BLK_RW_ASYNC, HZ/10);
3658 * Memory allocation/reclaim might be called from a WQ
3659 * context and the current implementation of the WQ
3660 * concurrency control doesn't recognize that
3661 * a particular WQ is congested if the worker thread is
3662 * looping without ever sleeping. Therefore we have to
3663 * do a short sleep here rather than calling
3666 if (current->flags & PF_WQ_WORKER)
3667 schedule_timeout_uninterruptible(1);
3678 static inline struct page *
3679 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3680 struct alloc_context *ac)
3682 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3683 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
3684 struct page *page = NULL;
3685 unsigned int alloc_flags;
3686 unsigned long did_some_progress;
3687 enum compact_priority compact_priority;
3688 enum compact_result compact_result;
3689 int compaction_retries;
3690 int no_progress_loops;
3691 unsigned long alloc_start = jiffies;
3692 unsigned int stall_timeout = 10 * HZ;
3693 unsigned int cpuset_mems_cookie;
3696 * In the slowpath, we sanity check order to avoid ever trying to
3697 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3698 * be using allocators in order of preference for an area that is
3701 if (order >= MAX_ORDER) {
3702 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3707 * We also sanity check to catch abuse of atomic reserves being used by
3708 * callers that are not in atomic context.
3710 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3711 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3712 gfp_mask &= ~__GFP_ATOMIC;
3715 compaction_retries = 0;
3716 no_progress_loops = 0;
3717 compact_priority = DEF_COMPACT_PRIORITY;
3718 cpuset_mems_cookie = read_mems_allowed_begin();
3721 * The fast path uses conservative alloc_flags to succeed only until
3722 * kswapd needs to be woken up, and to avoid the cost of setting up
3723 * alloc_flags precisely. So we do that now.
3725 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3728 * We need to recalculate the starting point for the zonelist iterator
3729 * because we might have used different nodemask in the fast path, or
3730 * there was a cpuset modification and we are retrying - otherwise we
3731 * could end up iterating over non-eligible zones endlessly.
3733 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
3734 ac->high_zoneidx, ac->nodemask);
3735 if (!ac->preferred_zoneref->zone)
3738 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3739 wake_all_kswapds(order, ac);
3742 * The adjusted alloc_flags might result in immediate success, so try
3745 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3750 * For costly allocations, try direct compaction first, as it's likely
3751 * that we have enough base pages and don't need to reclaim. For non-
3752 * movable high-order allocations, do that as well, as compaction will
3753 * try prevent permanent fragmentation by migrating from blocks of the
3755 * Don't try this for allocations that are allowed to ignore
3756 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
3758 if (can_direct_reclaim &&
3760 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
3761 && !gfp_pfmemalloc_allowed(gfp_mask)) {
3762 page = __alloc_pages_direct_compact(gfp_mask, order,
3764 INIT_COMPACT_PRIORITY,
3770 * Checks for costly allocations with __GFP_NORETRY, which
3771 * includes THP page fault allocations
3773 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
3775 * If compaction is deferred for high-order allocations,
3776 * it is because sync compaction recently failed. If
3777 * this is the case and the caller requested a THP
3778 * allocation, we do not want to heavily disrupt the
3779 * system, so we fail the allocation instead of entering
3782 if (compact_result == COMPACT_DEFERRED)
3786 * Looks like reclaim/compaction is worth trying, but
3787 * sync compaction could be very expensive, so keep
3788 * using async compaction.
3790 compact_priority = INIT_COMPACT_PRIORITY;
3795 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3796 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3797 wake_all_kswapds(order, ac);
3799 if (gfp_pfmemalloc_allowed(gfp_mask))
3800 alloc_flags = ALLOC_NO_WATERMARKS;
3803 * Reset the zonelist iterators if memory policies can be ignored.
3804 * These allocations are high priority and system rather than user
3807 if (!(alloc_flags & ALLOC_CPUSET) || (alloc_flags & ALLOC_NO_WATERMARKS)) {
3808 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3809 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
3810 ac->high_zoneidx, ac->nodemask);
3813 /* Attempt with potentially adjusted zonelist and alloc_flags */
3814 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3818 /* Caller is not willing to reclaim, we can't balance anything */
3819 if (!can_direct_reclaim)
3822 /* Make sure we know about allocations which stall for too long */
3823 if (time_after(jiffies, alloc_start + stall_timeout)) {
3824 warn_alloc(gfp_mask & ~__GFP_NOWARN, ac->nodemask,
3825 "page allocation stalls for %ums, order:%u",
3826 jiffies_to_msecs(jiffies-alloc_start), order);
3827 stall_timeout += 10 * HZ;
3830 /* Avoid recursion of direct reclaim */
3831 if (current->flags & PF_MEMALLOC)
3834 /* Try direct reclaim and then allocating */
3835 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3836 &did_some_progress);
3840 /* Try direct compaction and then allocating */
3841 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3842 compact_priority, &compact_result);
3846 /* Do not loop if specifically requested */
3847 if (gfp_mask & __GFP_NORETRY)
3851 * Do not retry costly high order allocations unless they are
3854 if (costly_order && !(gfp_mask & __GFP_REPEAT))
3857 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
3858 did_some_progress > 0, &no_progress_loops))
3862 * It doesn't make any sense to retry for the compaction if the order-0
3863 * reclaim is not able to make any progress because the current
3864 * implementation of the compaction depends on the sufficient amount
3865 * of free memory (see __compaction_suitable)
3867 if (did_some_progress > 0 &&
3868 should_compact_retry(ac, order, alloc_flags,
3869 compact_result, &compact_priority,
3870 &compaction_retries))
3874 * It's possible we raced with cpuset update so the OOM would be
3875 * premature (see below the nopage: label for full explanation).
3877 if (read_mems_allowed_retry(cpuset_mems_cookie))
3880 /* Reclaim has failed us, start killing things */
3881 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3885 /* Avoid allocations with no watermarks from looping endlessly */
3886 if (test_thread_flag(TIF_MEMDIE) &&
3887 (alloc_flags == ALLOC_NO_WATERMARKS ||
3888 (gfp_mask & __GFP_NOMEMALLOC)))
3891 /* Retry as long as the OOM killer is making progress */
3892 if (did_some_progress) {
3893 no_progress_loops = 0;
3899 * When updating a task's mems_allowed or mempolicy nodemask, it is
3900 * possible to race with parallel threads in such a way that our
3901 * allocation can fail while the mask is being updated. If we are about
3902 * to fail, check if the cpuset changed during allocation and if so,
3905 if (read_mems_allowed_retry(cpuset_mems_cookie))
3909 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
3912 if (gfp_mask & __GFP_NOFAIL) {
3914 * All existing users of the __GFP_NOFAIL are blockable, so warn
3915 * of any new users that actually require GFP_NOWAIT
3917 if (WARN_ON_ONCE(!can_direct_reclaim))
3921 * PF_MEMALLOC request from this context is rather bizarre
3922 * because we cannot reclaim anything and only can loop waiting
3923 * for somebody to do a work for us
3925 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
3928 * non failing costly orders are a hard requirement which we
3929 * are not prepared for much so let's warn about these users
3930 * so that we can identify them and convert them to something
3933 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
3936 * Help non-failing allocations by giving them access to memory
3937 * reserves but do not use ALLOC_NO_WATERMARKS because this
3938 * could deplete whole memory reserves which would just make
3939 * the situation worse
3941 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
3949 warn_alloc(gfp_mask, ac->nodemask,
3950 "page allocation failure: order:%u", order);
3955 static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
3956 struct zonelist *zonelist, nodemask_t *nodemask,
3957 struct alloc_context *ac, gfp_t *alloc_mask,
3958 unsigned int *alloc_flags)
3960 ac->high_zoneidx = gfp_zone(gfp_mask);
3961 ac->zonelist = zonelist;
3962 ac->nodemask = nodemask;
3963 ac->migratetype = gfpflags_to_migratetype(gfp_mask);
3965 if (cpusets_enabled()) {
3966 *alloc_mask |= __GFP_HARDWALL;
3968 ac->nodemask = &cpuset_current_mems_allowed;
3970 *alloc_flags |= ALLOC_CPUSET;
3973 lockdep_trace_alloc(gfp_mask);
3975 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3977 if (should_fail_alloc_page(gfp_mask, order))
3980 if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE)
3981 *alloc_flags |= ALLOC_CMA;
3986 /* Determine whether to spread dirty pages and what the first usable zone */
3987 static inline void finalise_ac(gfp_t gfp_mask,
3988 unsigned int order, struct alloc_context *ac)
3990 /* Dirty zone balancing only done in the fast path */
3991 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3994 * The preferred zone is used for statistics but crucially it is
3995 * also used as the starting point for the zonelist iterator. It
3996 * may get reset for allocations that ignore memory policies.
3998 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
3999 ac->high_zoneidx, ac->nodemask);
4003 * This is the 'heart' of the zoned buddy allocator.
4006 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
4007 struct zonelist *zonelist, nodemask_t *nodemask)
4010 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4011 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
4012 struct alloc_context ac = { };
4014 gfp_mask &= gfp_allowed_mask;
4015 if (!prepare_alloc_pages(gfp_mask, order, zonelist, nodemask, &ac, &alloc_mask, &alloc_flags))
4018 finalise_ac(gfp_mask, order, &ac);
4020 /* First allocation attempt */
4021 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
4026 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4027 * resp. GFP_NOIO which has to be inherited for all allocation requests
4028 * from a particular context which has been marked by
4029 * memalloc_no{fs,io}_{save,restore}.
4031 alloc_mask = current_gfp_context(gfp_mask);
4032 ac.spread_dirty_pages = false;
4035 * Restore the original nodemask if it was potentially replaced with
4036 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4038 if (unlikely(ac.nodemask != nodemask))
4039 ac.nodemask = nodemask;
4041 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
4044 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
4045 unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
4046 __free_pages(page, order);
4050 if (kmemcheck_enabled && page)
4051 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
4053 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
4057 EXPORT_SYMBOL(__alloc_pages_nodemask);
4060 * Common helper functions.
4062 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
4067 * __get_free_pages() returns a 32-bit address, which cannot represent
4070 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
4072 page = alloc_pages(gfp_mask, order);
4075 return (unsigned long) page_address(page);
4077 EXPORT_SYMBOL(__get_free_pages);
4079 unsigned long get_zeroed_page(gfp_t gfp_mask)
4081 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
4083 EXPORT_SYMBOL(get_zeroed_page);
4085 void __free_pages(struct page *page, unsigned int order)
4087 if (put_page_testzero(page)) {
4089 free_hot_cold_page(page, false);
4091 __free_pages_ok(page, order);
4095 EXPORT_SYMBOL(__free_pages);
4097 void free_pages(unsigned long addr, unsigned int order)
4100 VM_BUG_ON(!virt_addr_valid((void *)addr));
4101 __free_pages(virt_to_page((void *)addr), order);
4105 EXPORT_SYMBOL(free_pages);
4109 * An arbitrary-length arbitrary-offset area of memory which resides
4110 * within a 0 or higher order page. Multiple fragments within that page
4111 * are individually refcounted, in the page's reference counter.
4113 * The page_frag functions below provide a simple allocation framework for
4114 * page fragments. This is used by the network stack and network device
4115 * drivers to provide a backing region of memory for use as either an
4116 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4118 static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
4121 struct page *page = NULL;
4122 gfp_t gfp = gfp_mask;
4124 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4125 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
4127 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
4128 PAGE_FRAG_CACHE_MAX_ORDER);
4129 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
4131 if (unlikely(!page))
4132 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
4134 nc->va = page ? page_address(page) : NULL;
4139 void __page_frag_cache_drain(struct page *page, unsigned int count)
4141 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
4143 if (page_ref_sub_and_test(page, count)) {
4144 unsigned int order = compound_order(page);
4147 free_hot_cold_page(page, false);
4149 __free_pages_ok(page, order);
4152 EXPORT_SYMBOL(__page_frag_cache_drain);
4154 void *page_frag_alloc(struct page_frag_cache *nc,
4155 unsigned int fragsz, gfp_t gfp_mask)
4157 unsigned int size = PAGE_SIZE;
4161 if (unlikely(!nc->va)) {
4163 page = __page_frag_cache_refill(nc, gfp_mask);
4167 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4168 /* if size can vary use size else just use PAGE_SIZE */
4171 /* Even if we own the page, we do not use atomic_set().
4172 * This would break get_page_unless_zero() users.
4174 page_ref_add(page, size - 1);
4176 /* reset page count bias and offset to start of new frag */
4177 nc->pfmemalloc = page_is_pfmemalloc(page);
4178 nc->pagecnt_bias = size;
4182 offset = nc->offset - fragsz;
4183 if (unlikely(offset < 0)) {
4184 page = virt_to_page(nc->va);
4186 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
4189 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4190 /* if size can vary use size else just use PAGE_SIZE */
4193 /* OK, page count is 0, we can safely set it */
4194 set_page_count(page, size);
4196 /* reset page count bias and offset to start of new frag */
4197 nc->pagecnt_bias = size;
4198 offset = size - fragsz;
4202 nc->offset = offset;
4204 return nc->va + offset;
4206 EXPORT_SYMBOL(page_frag_alloc);
4209 * Frees a page fragment allocated out of either a compound or order 0 page.
4211 void page_frag_free(void *addr)
4213 struct page *page = virt_to_head_page(addr);
4215 if (unlikely(put_page_testzero(page)))
4216 __free_pages_ok(page, compound_order(page));
4218 EXPORT_SYMBOL(page_frag_free);
4220 static void *make_alloc_exact(unsigned long addr, unsigned int order,
4224 unsigned long alloc_end = addr + (PAGE_SIZE << order);
4225 unsigned long used = addr + PAGE_ALIGN(size);
4227 split_page(virt_to_page((void *)addr), order);
4228 while (used < alloc_end) {
4233 return (void *)addr;
4237 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4238 * @size: the number of bytes to allocate
4239 * @gfp_mask: GFP flags for the allocation
4241 * This function is similar to alloc_pages(), except that it allocates the
4242 * minimum number of pages to satisfy the request. alloc_pages() can only
4243 * allocate memory in power-of-two pages.
4245 * This function is also limited by MAX_ORDER.
4247 * Memory allocated by this function must be released by free_pages_exact().
4249 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
4251 unsigned int order = get_order(size);
4254 addr = __get_free_pages(gfp_mask, order);
4255 return make_alloc_exact(addr, order, size);
4257 EXPORT_SYMBOL(alloc_pages_exact);
4260 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4262 * @nid: the preferred node ID where memory should be allocated
4263 * @size: the number of bytes to allocate
4264 * @gfp_mask: GFP flags for the allocation
4266 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4269 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4271 unsigned int order = get_order(size);
4272 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4275 return make_alloc_exact((unsigned long)page_address(p), order, size);
4279 * free_pages_exact - release memory allocated via alloc_pages_exact()
4280 * @virt: the value returned by alloc_pages_exact.
4281 * @size: size of allocation, same value as passed to alloc_pages_exact().
4283 * Release the memory allocated by a previous call to alloc_pages_exact.
4285 void free_pages_exact(void *virt, size_t size)
4287 unsigned long addr = (unsigned long)virt;
4288 unsigned long end = addr + PAGE_ALIGN(size);
4290 while (addr < end) {
4295 EXPORT_SYMBOL(free_pages_exact);
4298 * nr_free_zone_pages - count number of pages beyond high watermark
4299 * @offset: The zone index of the highest zone
4301 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4302 * high watermark within all zones at or below a given zone index. For each
4303 * zone, the number of pages is calculated as:
4305 * nr_free_zone_pages = managed_pages - high_pages
4307 static unsigned long nr_free_zone_pages(int offset)
4312 /* Just pick one node, since fallback list is circular */
4313 unsigned long sum = 0;
4315 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4317 for_each_zone_zonelist(zone, z, zonelist, offset) {
4318 unsigned long size = zone->managed_pages;
4319 unsigned long high = high_wmark_pages(zone);
4328 * nr_free_buffer_pages - count number of pages beyond high watermark
4330 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4331 * watermark within ZONE_DMA and ZONE_NORMAL.
4333 unsigned long nr_free_buffer_pages(void)
4335 return nr_free_zone_pages(gfp_zone(GFP_USER));
4337 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4340 * nr_free_pagecache_pages - count number of pages beyond high watermark
4342 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4343 * high watermark within all zones.
4345 unsigned long nr_free_pagecache_pages(void)
4347 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4350 static inline void show_node(struct zone *zone)
4352 if (IS_ENABLED(CONFIG_NUMA))
4353 printk("Node %d ", zone_to_nid(zone));
4356 long si_mem_available(void)
4359 unsigned long pagecache;
4360 unsigned long wmark_low = 0;
4361 unsigned long pages[NR_LRU_LISTS];
4365 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4366 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
4369 wmark_low += zone->watermark[WMARK_LOW];
4372 * Estimate the amount of memory available for userspace allocations,
4373 * without causing swapping.
4375 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
4378 * Not all the page cache can be freed, otherwise the system will
4379 * start swapping. Assume at least half of the page cache, or the
4380 * low watermark worth of cache, needs to stay.
4382 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4383 pagecache -= min(pagecache / 2, wmark_low);
4384 available += pagecache;
4387 * Part of the reclaimable slab consists of items that are in use,
4388 * and cannot be freed. Cap this estimate at the low watermark.
4390 available += global_page_state(NR_SLAB_RECLAIMABLE) -
4391 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
4397 EXPORT_SYMBOL_GPL(si_mem_available);
4399 void si_meminfo(struct sysinfo *val)
4401 val->totalram = totalram_pages;
4402 val->sharedram = global_node_page_state(NR_SHMEM);
4403 val->freeram = global_page_state(NR_FREE_PAGES);
4404 val->bufferram = nr_blockdev_pages();
4405 val->totalhigh = totalhigh_pages;
4406 val->freehigh = nr_free_highpages();
4407 val->mem_unit = PAGE_SIZE;
4410 EXPORT_SYMBOL(si_meminfo);
4413 void si_meminfo_node(struct sysinfo *val, int nid)
4415 int zone_type; /* needs to be signed */
4416 unsigned long managed_pages = 0;
4417 unsigned long managed_highpages = 0;
4418 unsigned long free_highpages = 0;
4419 pg_data_t *pgdat = NODE_DATA(nid);
4421 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4422 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4423 val->totalram = managed_pages;
4424 val->sharedram = node_page_state(pgdat, NR_SHMEM);
4425 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
4426 #ifdef CONFIG_HIGHMEM
4427 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4428 struct zone *zone = &pgdat->node_zones[zone_type];
4430 if (is_highmem(zone)) {
4431 managed_highpages += zone->managed_pages;
4432 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4435 val->totalhigh = managed_highpages;
4436 val->freehigh = free_highpages;
4438 val->totalhigh = managed_highpages;
4439 val->freehigh = free_highpages;
4441 val->mem_unit = PAGE_SIZE;
4446 * Determine whether the node should be displayed or not, depending on whether
4447 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4449 static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
4451 if (!(flags & SHOW_MEM_FILTER_NODES))
4455 * no node mask - aka implicit memory numa policy. Do not bother with
4456 * the synchronization - read_mems_allowed_begin - because we do not
4457 * have to be precise here.
4460 nodemask = &cpuset_current_mems_allowed;
4462 return !node_isset(nid, *nodemask);
4465 #define K(x) ((x) << (PAGE_SHIFT-10))
4467 static void show_migration_types(unsigned char type)
4469 static const char types[MIGRATE_TYPES] = {
4470 [MIGRATE_UNMOVABLE] = 'U',
4471 [MIGRATE_MOVABLE] = 'M',
4472 [MIGRATE_RECLAIMABLE] = 'E',
4473 [MIGRATE_HIGHATOMIC] = 'H',
4475 [MIGRATE_CMA] = 'C',
4477 #ifdef CONFIG_MEMORY_ISOLATION
4478 [MIGRATE_ISOLATE] = 'I',
4481 char tmp[MIGRATE_TYPES + 1];
4485 for (i = 0; i < MIGRATE_TYPES; i++) {
4486 if (type & (1 << i))
4491 printk(KERN_CONT "(%s) ", tmp);
4495 * Show free area list (used inside shift_scroll-lock stuff)
4496 * We also calculate the percentage fragmentation. We do this by counting the
4497 * memory on each free list with the exception of the first item on the list.
4500 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4503 void show_free_areas(unsigned int filter, nodemask_t *nodemask)
4505 unsigned long free_pcp = 0;
4510 for_each_populated_zone(zone) {
4511 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4514 for_each_online_cpu(cpu)
4515 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4518 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4519 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4520 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4521 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4522 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4523 " free:%lu free_pcp:%lu free_cma:%lu\n",
4524 global_node_page_state(NR_ACTIVE_ANON),
4525 global_node_page_state(NR_INACTIVE_ANON),
4526 global_node_page_state(NR_ISOLATED_ANON),
4527 global_node_page_state(NR_ACTIVE_FILE),
4528 global_node_page_state(NR_INACTIVE_FILE),
4529 global_node_page_state(NR_ISOLATED_FILE),
4530 global_node_page_state(NR_UNEVICTABLE),
4531 global_node_page_state(NR_FILE_DIRTY),
4532 global_node_page_state(NR_WRITEBACK),
4533 global_node_page_state(NR_UNSTABLE_NFS),
4534 global_page_state(NR_SLAB_RECLAIMABLE),
4535 global_page_state(NR_SLAB_UNRECLAIMABLE),
4536 global_node_page_state(NR_FILE_MAPPED),
4537 global_node_page_state(NR_SHMEM),
4538 global_page_state(NR_PAGETABLE),
4539 global_page_state(NR_BOUNCE),
4540 global_page_state(NR_FREE_PAGES),
4542 global_page_state(NR_FREE_CMA_PAGES));
4544 for_each_online_pgdat(pgdat) {
4545 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
4549 " active_anon:%lukB"
4550 " inactive_anon:%lukB"
4551 " active_file:%lukB"
4552 " inactive_file:%lukB"
4553 " unevictable:%lukB"
4554 " isolated(anon):%lukB"
4555 " isolated(file):%lukB"
4560 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4562 " shmem_pmdmapped: %lukB"
4565 " writeback_tmp:%lukB"
4567 " all_unreclaimable? %s"
4570 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
4571 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
4572 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
4573 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
4574 K(node_page_state(pgdat, NR_UNEVICTABLE)),
4575 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
4576 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
4577 K(node_page_state(pgdat, NR_FILE_MAPPED)),
4578 K(node_page_state(pgdat, NR_FILE_DIRTY)),
4579 K(node_page_state(pgdat, NR_WRITEBACK)),
4580 K(node_page_state(pgdat, NR_SHMEM)),
4581 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4582 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
4583 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
4585 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
4587 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
4588 K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
4589 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
4593 for_each_populated_zone(zone) {
4596 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4600 for_each_online_cpu(cpu)
4601 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4610 " active_anon:%lukB"
4611 " inactive_anon:%lukB"
4612 " active_file:%lukB"
4613 " inactive_file:%lukB"
4614 " unevictable:%lukB"
4615 " writepending:%lukB"
4619 " slab_reclaimable:%lukB"
4620 " slab_unreclaimable:%lukB"
4621 " kernel_stack:%lukB"
4629 K(zone_page_state(zone, NR_FREE_PAGES)),
4630 K(min_wmark_pages(zone)),
4631 K(low_wmark_pages(zone)),
4632 K(high_wmark_pages(zone)),
4633 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
4634 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
4635 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
4636 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
4637 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
4638 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
4639 K(zone->present_pages),
4640 K(zone->managed_pages),
4641 K(zone_page_state(zone, NR_MLOCK)),
4642 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4643 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4644 zone_page_state(zone, NR_KERNEL_STACK_KB),
4645 K(zone_page_state(zone, NR_PAGETABLE)),
4646 K(zone_page_state(zone, NR_BOUNCE)),
4648 K(this_cpu_read(zone->pageset->pcp.count)),
4649 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
4650 printk("lowmem_reserve[]:");
4651 for (i = 0; i < MAX_NR_ZONES; i++)
4652 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
4653 printk(KERN_CONT "\n");
4656 for_each_populated_zone(zone) {
4658 unsigned long nr[MAX_ORDER], flags, total = 0;
4659 unsigned char types[MAX_ORDER];
4661 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4664 printk(KERN_CONT "%s: ", zone->name);
4666 spin_lock_irqsave(&zone->lock, flags);
4667 for (order = 0; order < MAX_ORDER; order++) {
4668 struct free_area *area = &zone->free_area[order];
4671 nr[order] = area->nr_free;
4672 total += nr[order] << order;
4675 for (type = 0; type < MIGRATE_TYPES; type++) {
4676 if (!list_empty(&area->free_list[type]))
4677 types[order] |= 1 << type;
4680 spin_unlock_irqrestore(&zone->lock, flags);
4681 for (order = 0; order < MAX_ORDER; order++) {
4682 printk(KERN_CONT "%lu*%lukB ",
4683 nr[order], K(1UL) << order);
4685 show_migration_types(types[order]);
4687 printk(KERN_CONT "= %lukB\n", K(total));
4690 hugetlb_show_meminfo();
4692 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
4694 show_swap_cache_info();
4697 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4699 zoneref->zone = zone;
4700 zoneref->zone_idx = zone_idx(zone);
4704 * Builds allocation fallback zone lists.
4706 * Add all populated zones of a node to the zonelist.
4708 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4712 enum zone_type zone_type = MAX_NR_ZONES;
4716 zone = pgdat->node_zones + zone_type;
4717 if (managed_zone(zone)) {
4718 zoneref_set_zone(zone,
4719 &zonelist->_zonerefs[nr_zones++]);
4720 check_highest_zone(zone_type);
4722 } while (zone_type);
4730 * 0 = automatic detection of better ordering.
4731 * 1 = order by ([node] distance, -zonetype)
4732 * 2 = order by (-zonetype, [node] distance)
4734 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4735 * the same zonelist. So only NUMA can configure this param.
4737 #define ZONELIST_ORDER_DEFAULT 0
4738 #define ZONELIST_ORDER_NODE 1
4739 #define ZONELIST_ORDER_ZONE 2
4741 /* zonelist order in the kernel.
4742 * set_zonelist_order() will set this to NODE or ZONE.
4744 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4745 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4749 /* The value user specified ....changed by config */
4750 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4751 /* string for sysctl */
4752 #define NUMA_ZONELIST_ORDER_LEN 16
4753 char numa_zonelist_order[16] = "default";
4756 * interface for configure zonelist ordering.
4757 * command line option "numa_zonelist_order"
4758 * = "[dD]efault - default, automatic configuration.
4759 * = "[nN]ode - order by node locality, then by zone within node
4760 * = "[zZ]one - order by zone, then by locality within zone
4763 static int __parse_numa_zonelist_order(char *s)
4765 if (*s == 'd' || *s == 'D') {
4766 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4767 } else if (*s == 'n' || *s == 'N') {
4768 user_zonelist_order = ZONELIST_ORDER_NODE;
4769 } else if (*s == 'z' || *s == 'Z') {
4770 user_zonelist_order = ZONELIST_ORDER_ZONE;
4772 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4778 static __init int setup_numa_zonelist_order(char *s)
4785 ret = __parse_numa_zonelist_order(s);
4787 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4791 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4794 * sysctl handler for numa_zonelist_order
4796 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4797 void __user *buffer, size_t *length,
4800 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4802 static DEFINE_MUTEX(zl_order_mutex);
4804 mutex_lock(&zl_order_mutex);
4806 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4810 strcpy(saved_string, (char *)table->data);
4812 ret = proc_dostring(table, write, buffer, length, ppos);
4816 int oldval = user_zonelist_order;
4818 ret = __parse_numa_zonelist_order((char *)table->data);
4821 * bogus value. restore saved string
4823 strncpy((char *)table->data, saved_string,
4824 NUMA_ZONELIST_ORDER_LEN);
4825 user_zonelist_order = oldval;
4826 } else if (oldval != user_zonelist_order) {
4827 mutex_lock(&zonelists_mutex);
4828 build_all_zonelists(NULL, NULL);
4829 mutex_unlock(&zonelists_mutex);
4833 mutex_unlock(&zl_order_mutex);
4838 #define MAX_NODE_LOAD (nr_online_nodes)
4839 static int node_load[MAX_NUMNODES];
4842 * find_next_best_node - find the next node that should appear in a given node's fallback list
4843 * @node: node whose fallback list we're appending
4844 * @used_node_mask: nodemask_t of already used nodes
4846 * We use a number of factors to determine which is the next node that should
4847 * appear on a given node's fallback list. The node should not have appeared
4848 * already in @node's fallback list, and it should be the next closest node
4849 * according to the distance array (which contains arbitrary distance values
4850 * from each node to each node in the system), and should also prefer nodes
4851 * with no CPUs, since presumably they'll have very little allocation pressure
4852 * on them otherwise.
4853 * It returns -1 if no node is found.
4855 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4858 int min_val = INT_MAX;
4859 int best_node = NUMA_NO_NODE;
4860 const struct cpumask *tmp = cpumask_of_node(0);
4862 /* Use the local node if we haven't already */
4863 if (!node_isset(node, *used_node_mask)) {
4864 node_set(node, *used_node_mask);
4868 for_each_node_state(n, N_MEMORY) {
4870 /* Don't want a node to appear more than once */
4871 if (node_isset(n, *used_node_mask))
4874 /* Use the distance array to find the distance */
4875 val = node_distance(node, n);
4877 /* Penalize nodes under us ("prefer the next node") */
4880 /* Give preference to headless and unused nodes */
4881 tmp = cpumask_of_node(n);
4882 if (!cpumask_empty(tmp))
4883 val += PENALTY_FOR_NODE_WITH_CPUS;
4885 /* Slight preference for less loaded node */
4886 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4887 val += node_load[n];
4889 if (val < min_val) {
4896 node_set(best_node, *used_node_mask);
4903 * Build zonelists ordered by node and zones within node.
4904 * This results in maximum locality--normal zone overflows into local
4905 * DMA zone, if any--but risks exhausting DMA zone.
4907 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4910 struct zonelist *zonelist;
4912 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4913 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4915 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4916 zonelist->_zonerefs[j].zone = NULL;
4917 zonelist->_zonerefs[j].zone_idx = 0;
4921 * Build gfp_thisnode zonelists
4923 static void build_thisnode_zonelists(pg_data_t *pgdat)
4926 struct zonelist *zonelist;
4928 zonelist = &pgdat->node_zonelists[ZONELIST_NOFALLBACK];
4929 j = build_zonelists_node(pgdat, zonelist, 0);
4930 zonelist->_zonerefs[j].zone = NULL;
4931 zonelist->_zonerefs[j].zone_idx = 0;
4935 * Build zonelists ordered by zone and nodes within zones.
4936 * This results in conserving DMA zone[s] until all Normal memory is
4937 * exhausted, but results in overflowing to remote node while memory
4938 * may still exist in local DMA zone.
4940 static int node_order[MAX_NUMNODES];
4942 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4945 int zone_type; /* needs to be signed */
4947 struct zonelist *zonelist;
4949 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4951 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4952 for (j = 0; j < nr_nodes; j++) {
4953 node = node_order[j];
4954 z = &NODE_DATA(node)->node_zones[zone_type];
4955 if (managed_zone(z)) {
4957 &zonelist->_zonerefs[pos++]);
4958 check_highest_zone(zone_type);
4962 zonelist->_zonerefs[pos].zone = NULL;
4963 zonelist->_zonerefs[pos].zone_idx = 0;
4966 #if defined(CONFIG_64BIT)
4968 * Devices that require DMA32/DMA are relatively rare and do not justify a
4969 * penalty to every machine in case the specialised case applies. Default
4970 * to Node-ordering on 64-bit NUMA machines
4972 static int default_zonelist_order(void)
4974 return ZONELIST_ORDER_NODE;
4978 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4979 * by the kernel. If processes running on node 0 deplete the low memory zone
4980 * then reclaim will occur more frequency increasing stalls and potentially
4981 * be easier to OOM if a large percentage of the zone is under writeback or
4982 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4983 * Hence, default to zone ordering on 32-bit.
4985 static int default_zonelist_order(void)
4987 return ZONELIST_ORDER_ZONE;
4989 #endif /* CONFIG_64BIT */
4991 static void set_zonelist_order(void)
4993 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4994 current_zonelist_order = default_zonelist_order();
4996 current_zonelist_order = user_zonelist_order;
4999 static void build_zonelists(pg_data_t *pgdat)
5002 nodemask_t used_mask;
5003 int local_node, prev_node;
5004 struct zonelist *zonelist;
5005 unsigned int order = current_zonelist_order;
5007 /* initialize zonelists */
5008 for (i = 0; i < MAX_ZONELISTS; i++) {
5009 zonelist = pgdat->node_zonelists + i;
5010 zonelist->_zonerefs[0].zone = NULL;
5011 zonelist->_zonerefs[0].zone_idx = 0;
5014 /* NUMA-aware ordering of nodes */
5015 local_node = pgdat->node_id;
5016 load = nr_online_nodes;
5017 prev_node = local_node;
5018 nodes_clear(used_mask);
5020 memset(node_order, 0, sizeof(node_order));
5023 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
5025 * We don't want to pressure a particular node.
5026 * So adding penalty to the first node in same
5027 * distance group to make it round-robin.
5029 if (node_distance(local_node, node) !=
5030 node_distance(local_node, prev_node))
5031 node_load[node] = load;
5035 if (order == ZONELIST_ORDER_NODE)
5036 build_zonelists_in_node_order(pgdat, node);
5038 node_order[i++] = node; /* remember order */
5041 if (order == ZONELIST_ORDER_ZONE) {
5042 /* calculate node order -- i.e., DMA last! */
5043 build_zonelists_in_zone_order(pgdat, i);
5046 build_thisnode_zonelists(pgdat);
5049 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5051 * Return node id of node used for "local" allocations.
5052 * I.e., first node id of first zone in arg node's generic zonelist.
5053 * Used for initializing percpu 'numa_mem', which is used primarily
5054 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5056 int local_memory_node(int node)
5060 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
5061 gfp_zone(GFP_KERNEL),
5063 return z->zone->node;
5067 static void setup_min_unmapped_ratio(void);
5068 static void setup_min_slab_ratio(void);
5069 #else /* CONFIG_NUMA */
5071 static void set_zonelist_order(void)
5073 current_zonelist_order = ZONELIST_ORDER_ZONE;
5076 static void build_zonelists(pg_data_t *pgdat)
5078 int node, local_node;
5080 struct zonelist *zonelist;
5082 local_node = pgdat->node_id;
5084 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
5085 j = build_zonelists_node(pgdat, zonelist, 0);
5088 * Now we build the zonelist so that it contains the zones
5089 * of all the other nodes.
5090 * We don't want to pressure a particular node, so when
5091 * building the zones for node N, we make sure that the
5092 * zones coming right after the local ones are those from
5093 * node N+1 (modulo N)
5095 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
5096 if (!node_online(node))
5098 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
5100 for (node = 0; node < local_node; node++) {
5101 if (!node_online(node))
5103 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
5106 zonelist->_zonerefs[j].zone = NULL;
5107 zonelist->_zonerefs[j].zone_idx = 0;
5110 #endif /* CONFIG_NUMA */
5113 * Boot pageset table. One per cpu which is going to be used for all
5114 * zones and all nodes. The parameters will be set in such a way
5115 * that an item put on a list will immediately be handed over to
5116 * the buddy list. This is safe since pageset manipulation is done
5117 * with interrupts disabled.
5119 * The boot_pagesets must be kept even after bootup is complete for
5120 * unused processors and/or zones. They do play a role for bootstrapping
5121 * hotplugged processors.
5123 * zoneinfo_show() and maybe other functions do
5124 * not check if the processor is online before following the pageset pointer.
5125 * Other parts of the kernel may not check if the zone is available.
5127 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
5128 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
5129 static void setup_zone_pageset(struct zone *zone);
5132 * Global mutex to protect against size modification of zonelists
5133 * as well as to serialize pageset setup for the new populated zone.
5135 DEFINE_MUTEX(zonelists_mutex);
5137 /* return values int ....just for stop_machine() */
5138 static int __build_all_zonelists(void *data)
5142 pg_data_t *self = data;
5145 memset(node_load, 0, sizeof(node_load));
5148 if (self && !node_online(self->node_id)) {
5149 build_zonelists(self);
5152 for_each_online_node(nid) {
5153 pg_data_t *pgdat = NODE_DATA(nid);
5155 build_zonelists(pgdat);
5159 * Initialize the boot_pagesets that are going to be used
5160 * for bootstrapping processors. The real pagesets for
5161 * each zone will be allocated later when the per cpu
5162 * allocator is available.
5164 * boot_pagesets are used also for bootstrapping offline
5165 * cpus if the system is already booted because the pagesets
5166 * are needed to initialize allocators on a specific cpu too.
5167 * F.e. the percpu allocator needs the page allocator which
5168 * needs the percpu allocator in order to allocate its pagesets
5169 * (a chicken-egg dilemma).
5171 for_each_possible_cpu(cpu) {
5172 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
5174 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5176 * We now know the "local memory node" for each node--
5177 * i.e., the node of the first zone in the generic zonelist.
5178 * Set up numa_mem percpu variable for on-line cpus. During
5179 * boot, only the boot cpu should be on-line; we'll init the
5180 * secondary cpus' numa_mem as they come on-line. During
5181 * node/memory hotplug, we'll fixup all on-line cpus.
5183 if (cpu_online(cpu))
5184 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
5191 static noinline void __init
5192 build_all_zonelists_init(void)
5194 __build_all_zonelists(NULL);
5195 mminit_verify_zonelist();
5196 cpuset_init_current_mems_allowed();
5200 * Called with zonelists_mutex held always
5201 * unless system_state == SYSTEM_BOOTING.
5203 * __ref due to (1) call of __meminit annotated setup_zone_pageset
5204 * [we're only called with non-NULL zone through __meminit paths] and
5205 * (2) call of __init annotated helper build_all_zonelists_init
5206 * [protected by SYSTEM_BOOTING].
5208 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
5210 set_zonelist_order();
5212 if (system_state == SYSTEM_BOOTING) {
5213 build_all_zonelists_init();
5215 #ifdef CONFIG_MEMORY_HOTPLUG
5217 setup_zone_pageset(zone);
5219 /* we have to stop all cpus to guarantee there is no user
5221 stop_machine(__build_all_zonelists, pgdat, NULL);
5222 /* cpuset refresh routine should be here */
5224 vm_total_pages = nr_free_pagecache_pages();
5226 * Disable grouping by mobility if the number of pages in the
5227 * system is too low to allow the mechanism to work. It would be
5228 * more accurate, but expensive to check per-zone. This check is
5229 * made on memory-hotadd so a system can start with mobility
5230 * disabled and enable it later
5232 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5233 page_group_by_mobility_disabled = 1;
5235 page_group_by_mobility_disabled = 0;
5237 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5239 zonelist_order_name[current_zonelist_order],
5240 page_group_by_mobility_disabled ? "off" : "on",
5243 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5248 * Initially all pages are reserved - free ones are freed
5249 * up by free_all_bootmem() once the early boot process is
5250 * done. Non-atomic initialization, single-pass.
5252 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5253 unsigned long start_pfn, enum memmap_context context)
5255 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
5256 unsigned long end_pfn = start_pfn + size;
5257 pg_data_t *pgdat = NODE_DATA(nid);
5259 unsigned long nr_initialised = 0;
5260 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5261 struct memblock_region *r = NULL, *tmp;
5264 if (highest_memmap_pfn < end_pfn - 1)
5265 highest_memmap_pfn = end_pfn - 1;
5268 * Honor reservation requested by the driver for this ZONE_DEVICE
5271 if (altmap && start_pfn == altmap->base_pfn)
5272 start_pfn += altmap->reserve;
5274 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5276 * There can be holes in boot-time mem_map[]s handed to this
5277 * function. They do not exist on hotplugged memory.
5279 if (context != MEMMAP_EARLY)
5282 if (!early_pfn_valid(pfn)) {
5283 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5285 * Skip to the pfn preceding the next valid one (or
5286 * end_pfn), such that we hit a valid pfn (or end_pfn)
5287 * on our next iteration of the loop.
5289 pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1;
5293 if (!early_pfn_in_nid(pfn, nid))
5295 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5298 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5300 * Check given memblock attribute by firmware which can affect
5301 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5302 * mirrored, it's an overlapped memmap init. skip it.
5304 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5305 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5306 for_each_memblock(memory, tmp)
5307 if (pfn < memblock_region_memory_end_pfn(tmp))
5311 if (pfn >= memblock_region_memory_base_pfn(r) &&
5312 memblock_is_mirror(r)) {
5313 /* already initialized as NORMAL */
5314 pfn = memblock_region_memory_end_pfn(r);
5322 * Mark the block movable so that blocks are reserved for
5323 * movable at startup. This will force kernel allocations
5324 * to reserve their blocks rather than leaking throughout
5325 * the address space during boot when many long-lived
5326 * kernel allocations are made.
5328 * bitmap is created for zone's valid pfn range. but memmap
5329 * can be created for invalid pages (for alignment)
5330 * check here not to call set_pageblock_migratetype() against
5333 if (!(pfn & (pageblock_nr_pages - 1))) {
5334 struct page *page = pfn_to_page(pfn);
5336 __init_single_page(page, pfn, zone, nid);
5337 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5339 __init_single_pfn(pfn, zone, nid);
5344 static void __meminit zone_init_free_lists(struct zone *zone)
5346 unsigned int order, t;
5347 for_each_migratetype_order(order, t) {
5348 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5349 zone->free_area[order].nr_free = 0;
5353 #ifndef __HAVE_ARCH_MEMMAP_INIT
5354 #define memmap_init(size, nid, zone, start_pfn) \
5355 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5358 static int zone_batchsize(struct zone *zone)
5364 * The per-cpu-pages pools are set to around 1000th of the
5365 * size of the zone. But no more than 1/2 of a meg.
5367 * OK, so we don't know how big the cache is. So guess.
5369 batch = zone->managed_pages / 1024;
5370 if (batch * PAGE_SIZE > 512 * 1024)
5371 batch = (512 * 1024) / PAGE_SIZE;
5372 batch /= 4; /* We effectively *= 4 below */
5377 * Clamp the batch to a 2^n - 1 value. Having a power
5378 * of 2 value was found to be more likely to have
5379 * suboptimal cache aliasing properties in some cases.
5381 * For example if 2 tasks are alternately allocating
5382 * batches of pages, one task can end up with a lot
5383 * of pages of one half of the possible page colors
5384 * and the other with pages of the other colors.
5386 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5391 /* The deferral and batching of frees should be suppressed under NOMMU
5394 * The problem is that NOMMU needs to be able to allocate large chunks
5395 * of contiguous memory as there's no hardware page translation to
5396 * assemble apparent contiguous memory from discontiguous pages.
5398 * Queueing large contiguous runs of pages for batching, however,
5399 * causes the pages to actually be freed in smaller chunks. As there
5400 * can be a significant delay between the individual batches being
5401 * recycled, this leads to the once large chunks of space being
5402 * fragmented and becoming unavailable for high-order allocations.
5409 * pcp->high and pcp->batch values are related and dependent on one another:
5410 * ->batch must never be higher then ->high.
5411 * The following function updates them in a safe manner without read side
5414 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5415 * those fields changing asynchronously (acording the the above rule).
5417 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5418 * outside of boot time (or some other assurance that no concurrent updaters
5421 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5422 unsigned long batch)
5424 /* start with a fail safe value for batch */
5428 /* Update high, then batch, in order */
5435 /* a companion to pageset_set_high() */
5436 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5438 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5441 static void pageset_init(struct per_cpu_pageset *p)
5443 struct per_cpu_pages *pcp;
5446 memset(p, 0, sizeof(*p));
5450 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5451 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5454 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5457 pageset_set_batch(p, batch);
5461 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5462 * to the value high for the pageset p.
5464 static void pageset_set_high(struct per_cpu_pageset *p,
5467 unsigned long batch = max(1UL, high / 4);
5468 if ((high / 4) > (PAGE_SHIFT * 8))
5469 batch = PAGE_SHIFT * 8;
5471 pageset_update(&p->pcp, high, batch);
5474 static void pageset_set_high_and_batch(struct zone *zone,
5475 struct per_cpu_pageset *pcp)
5477 if (percpu_pagelist_fraction)
5478 pageset_set_high(pcp,
5479 (zone->managed_pages /
5480 percpu_pagelist_fraction));
5482 pageset_set_batch(pcp, zone_batchsize(zone));
5485 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5487 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5490 pageset_set_high_and_batch(zone, pcp);
5493 static void __meminit setup_zone_pageset(struct zone *zone)
5496 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5497 for_each_possible_cpu(cpu)
5498 zone_pageset_init(zone, cpu);
5502 * Allocate per cpu pagesets and initialize them.
5503 * Before this call only boot pagesets were available.
5505 void __init setup_per_cpu_pageset(void)
5507 struct pglist_data *pgdat;
5510 for_each_populated_zone(zone)
5511 setup_zone_pageset(zone);
5513 for_each_online_pgdat(pgdat)
5514 pgdat->per_cpu_nodestats =
5515 alloc_percpu(struct per_cpu_nodestat);
5518 static __meminit void zone_pcp_init(struct zone *zone)
5521 * per cpu subsystem is not up at this point. The following code
5522 * relies on the ability of the linker to provide the
5523 * offset of a (static) per cpu variable into the per cpu area.
5525 zone->pageset = &boot_pageset;
5527 if (populated_zone(zone))
5528 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5529 zone->name, zone->present_pages,
5530 zone_batchsize(zone));
5533 void __meminit init_currently_empty_zone(struct zone *zone,
5534 unsigned long zone_start_pfn,
5537 struct pglist_data *pgdat = zone->zone_pgdat;
5539 pgdat->nr_zones = zone_idx(zone) + 1;
5541 zone->zone_start_pfn = zone_start_pfn;
5543 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5544 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5546 (unsigned long)zone_idx(zone),
5547 zone_start_pfn, (zone_start_pfn + size));
5549 zone_init_free_lists(zone);
5550 zone->initialized = 1;
5553 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5554 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5557 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5559 int __meminit __early_pfn_to_nid(unsigned long pfn,
5560 struct mminit_pfnnid_cache *state)
5562 unsigned long start_pfn, end_pfn;
5565 if (state->last_start <= pfn && pfn < state->last_end)
5566 return state->last_nid;
5568 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5570 state->last_start = start_pfn;
5571 state->last_end = end_pfn;
5572 state->last_nid = nid;
5577 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5580 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5581 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5582 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5584 * If an architecture guarantees that all ranges registered contain no holes
5585 * and may be freed, this this function may be used instead of calling
5586 * memblock_free_early_nid() manually.
5588 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5590 unsigned long start_pfn, end_pfn;
5593 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5594 start_pfn = min(start_pfn, max_low_pfn);
5595 end_pfn = min(end_pfn, max_low_pfn);
5597 if (start_pfn < end_pfn)
5598 memblock_free_early_nid(PFN_PHYS(start_pfn),
5599 (end_pfn - start_pfn) << PAGE_SHIFT,
5605 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5606 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5608 * If an architecture guarantees that all ranges registered contain no holes and may
5609 * be freed, this function may be used instead of calling memory_present() manually.
5611 void __init sparse_memory_present_with_active_regions(int nid)
5613 unsigned long start_pfn, end_pfn;
5616 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5617 memory_present(this_nid, start_pfn, end_pfn);
5621 * get_pfn_range_for_nid - Return the start and end page frames for a node
5622 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5623 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5624 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5626 * It returns the start and end page frame of a node based on information
5627 * provided by memblock_set_node(). If called for a node
5628 * with no available memory, a warning is printed and the start and end
5631 void __meminit get_pfn_range_for_nid(unsigned int nid,
5632 unsigned long *start_pfn, unsigned long *end_pfn)
5634 unsigned long this_start_pfn, this_end_pfn;
5640 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5641 *start_pfn = min(*start_pfn, this_start_pfn);
5642 *end_pfn = max(*end_pfn, this_end_pfn);
5645 if (*start_pfn == -1UL)
5650 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5651 * assumption is made that zones within a node are ordered in monotonic
5652 * increasing memory addresses so that the "highest" populated zone is used
5654 static void __init find_usable_zone_for_movable(void)
5657 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5658 if (zone_index == ZONE_MOVABLE)
5661 if (arch_zone_highest_possible_pfn[zone_index] >
5662 arch_zone_lowest_possible_pfn[zone_index])
5666 VM_BUG_ON(zone_index == -1);
5667 movable_zone = zone_index;
5671 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5672 * because it is sized independent of architecture. Unlike the other zones,
5673 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5674 * in each node depending on the size of each node and how evenly kernelcore
5675 * is distributed. This helper function adjusts the zone ranges
5676 * provided by the architecture for a given node by using the end of the
5677 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5678 * zones within a node are in order of monotonic increases memory addresses
5680 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5681 unsigned long zone_type,
5682 unsigned long node_start_pfn,
5683 unsigned long node_end_pfn,
5684 unsigned long *zone_start_pfn,
5685 unsigned long *zone_end_pfn)
5687 /* Only adjust if ZONE_MOVABLE is on this node */
5688 if (zone_movable_pfn[nid]) {
5689 /* Size ZONE_MOVABLE */
5690 if (zone_type == ZONE_MOVABLE) {
5691 *zone_start_pfn = zone_movable_pfn[nid];
5692 *zone_end_pfn = min(node_end_pfn,
5693 arch_zone_highest_possible_pfn[movable_zone]);
5695 /* Adjust for ZONE_MOVABLE starting within this range */
5696 } else if (!mirrored_kernelcore &&
5697 *zone_start_pfn < zone_movable_pfn[nid] &&
5698 *zone_end_pfn > zone_movable_pfn[nid]) {
5699 *zone_end_pfn = zone_movable_pfn[nid];
5701 /* Check if this whole range is within ZONE_MOVABLE */
5702 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5703 *zone_start_pfn = *zone_end_pfn;
5708 * Return the number of pages a zone spans in a node, including holes
5709 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5711 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5712 unsigned long zone_type,
5713 unsigned long node_start_pfn,
5714 unsigned long node_end_pfn,
5715 unsigned long *zone_start_pfn,
5716 unsigned long *zone_end_pfn,
5717 unsigned long *ignored)
5719 /* When hotadd a new node from cpu_up(), the node should be empty */
5720 if (!node_start_pfn && !node_end_pfn)
5723 /* Get the start and end of the zone */
5724 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5725 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5726 adjust_zone_range_for_zone_movable(nid, zone_type,
5727 node_start_pfn, node_end_pfn,
5728 zone_start_pfn, zone_end_pfn);
5730 /* Check that this node has pages within the zone's required range */
5731 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5734 /* Move the zone boundaries inside the node if necessary */
5735 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5736 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5738 /* Return the spanned pages */
5739 return *zone_end_pfn - *zone_start_pfn;
5743 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5744 * then all holes in the requested range will be accounted for.
5746 unsigned long __meminit __absent_pages_in_range(int nid,
5747 unsigned long range_start_pfn,
5748 unsigned long range_end_pfn)
5750 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5751 unsigned long start_pfn, end_pfn;
5754 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5755 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5756 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5757 nr_absent -= end_pfn - start_pfn;
5763 * absent_pages_in_range - Return number of page frames in holes within a range
5764 * @start_pfn: The start PFN to start searching for holes
5765 * @end_pfn: The end PFN to stop searching for holes
5767 * It returns the number of pages frames in memory holes within a range.
5769 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5770 unsigned long end_pfn)
5772 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5775 /* Return the number of page frames in holes in a zone on a node */
5776 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5777 unsigned long zone_type,
5778 unsigned long node_start_pfn,
5779 unsigned long node_end_pfn,
5780 unsigned long *ignored)
5782 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5783 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5784 unsigned long zone_start_pfn, zone_end_pfn;
5785 unsigned long nr_absent;
5787 /* When hotadd a new node from cpu_up(), the node should be empty */
5788 if (!node_start_pfn && !node_end_pfn)
5791 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5792 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5794 adjust_zone_range_for_zone_movable(nid, zone_type,
5795 node_start_pfn, node_end_pfn,
5796 &zone_start_pfn, &zone_end_pfn);
5797 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5800 * ZONE_MOVABLE handling.
5801 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5804 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
5805 unsigned long start_pfn, end_pfn;
5806 struct memblock_region *r;
5808 for_each_memblock(memory, r) {
5809 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5810 zone_start_pfn, zone_end_pfn);
5811 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5812 zone_start_pfn, zone_end_pfn);
5814 if (zone_type == ZONE_MOVABLE &&
5815 memblock_is_mirror(r))
5816 nr_absent += end_pfn - start_pfn;
5818 if (zone_type == ZONE_NORMAL &&
5819 !memblock_is_mirror(r))
5820 nr_absent += end_pfn - start_pfn;
5827 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5828 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5829 unsigned long zone_type,
5830 unsigned long node_start_pfn,
5831 unsigned long node_end_pfn,
5832 unsigned long *zone_start_pfn,
5833 unsigned long *zone_end_pfn,
5834 unsigned long *zones_size)
5838 *zone_start_pfn = node_start_pfn;
5839 for (zone = 0; zone < zone_type; zone++)
5840 *zone_start_pfn += zones_size[zone];
5842 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5844 return zones_size[zone_type];
5847 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5848 unsigned long zone_type,
5849 unsigned long node_start_pfn,
5850 unsigned long node_end_pfn,
5851 unsigned long *zholes_size)
5856 return zholes_size[zone_type];
5859 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5861 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5862 unsigned long node_start_pfn,
5863 unsigned long node_end_pfn,
5864 unsigned long *zones_size,
5865 unsigned long *zholes_size)
5867 unsigned long realtotalpages = 0, totalpages = 0;
5870 for (i = 0; i < MAX_NR_ZONES; i++) {
5871 struct zone *zone = pgdat->node_zones + i;
5872 unsigned long zone_start_pfn, zone_end_pfn;
5873 unsigned long size, real_size;
5875 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5881 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5882 node_start_pfn, node_end_pfn,
5885 zone->zone_start_pfn = zone_start_pfn;
5887 zone->zone_start_pfn = 0;
5888 zone->spanned_pages = size;
5889 zone->present_pages = real_size;
5892 realtotalpages += real_size;
5895 pgdat->node_spanned_pages = totalpages;
5896 pgdat->node_present_pages = realtotalpages;
5897 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5901 #ifndef CONFIG_SPARSEMEM
5903 * Calculate the size of the zone->blockflags rounded to an unsigned long
5904 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5905 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5906 * round what is now in bits to nearest long in bits, then return it in
5909 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5911 unsigned long usemapsize;
5913 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5914 usemapsize = roundup(zonesize, pageblock_nr_pages);
5915 usemapsize = usemapsize >> pageblock_order;
5916 usemapsize *= NR_PAGEBLOCK_BITS;
5917 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5919 return usemapsize / 8;
5922 static void __init setup_usemap(struct pglist_data *pgdat,
5924 unsigned long zone_start_pfn,
5925 unsigned long zonesize)
5927 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5928 zone->pageblock_flags = NULL;
5930 zone->pageblock_flags =
5931 memblock_virt_alloc_node_nopanic(usemapsize,
5935 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5936 unsigned long zone_start_pfn, unsigned long zonesize) {}
5937 #endif /* CONFIG_SPARSEMEM */
5939 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5941 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5942 void __paginginit set_pageblock_order(void)
5946 /* Check that pageblock_nr_pages has not already been setup */
5947 if (pageblock_order)
5950 if (HPAGE_SHIFT > PAGE_SHIFT)
5951 order = HUGETLB_PAGE_ORDER;
5953 order = MAX_ORDER - 1;
5956 * Assume the largest contiguous order of interest is a huge page.
5957 * This value may be variable depending on boot parameters on IA64 and
5960 pageblock_order = order;
5962 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5965 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5966 * is unused as pageblock_order is set at compile-time. See
5967 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5970 void __paginginit set_pageblock_order(void)
5974 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5976 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5977 unsigned long present_pages)
5979 unsigned long pages = spanned_pages;
5982 * Provide a more accurate estimation if there are holes within
5983 * the zone and SPARSEMEM is in use. If there are holes within the
5984 * zone, each populated memory region may cost us one or two extra
5985 * memmap pages due to alignment because memmap pages for each
5986 * populated regions may not be naturally aligned on page boundary.
5987 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5989 if (spanned_pages > present_pages + (present_pages >> 4) &&
5990 IS_ENABLED(CONFIG_SPARSEMEM))
5991 pages = present_pages;
5993 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5997 * Set up the zone data structures:
5998 * - mark all pages reserved
5999 * - mark all memory queues empty
6000 * - clear the memory bitmaps
6002 * NOTE: pgdat should get zeroed by caller.
6004 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
6007 int nid = pgdat->node_id;
6009 pgdat_resize_init(pgdat);
6010 #ifdef CONFIG_NUMA_BALANCING
6011 spin_lock_init(&pgdat->numabalancing_migrate_lock);
6012 pgdat->numabalancing_migrate_nr_pages = 0;
6013 pgdat->numabalancing_migrate_next_window = jiffies;
6015 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6016 spin_lock_init(&pgdat->split_queue_lock);
6017 INIT_LIST_HEAD(&pgdat->split_queue);
6018 pgdat->split_queue_len = 0;
6020 init_waitqueue_head(&pgdat->kswapd_wait);
6021 init_waitqueue_head(&pgdat->pfmemalloc_wait);
6022 #ifdef CONFIG_COMPACTION
6023 init_waitqueue_head(&pgdat->kcompactd_wait);
6025 pgdat_page_ext_init(pgdat);
6026 spin_lock_init(&pgdat->lru_lock);
6027 lruvec_init(node_lruvec(pgdat));
6029 for (j = 0; j < MAX_NR_ZONES; j++) {
6030 struct zone *zone = pgdat->node_zones + j;
6031 unsigned long size, realsize, freesize, memmap_pages;
6032 unsigned long zone_start_pfn = zone->zone_start_pfn;
6034 size = zone->spanned_pages;
6035 realsize = freesize = zone->present_pages;
6038 * Adjust freesize so that it accounts for how much memory
6039 * is used by this zone for memmap. This affects the watermark
6040 * and per-cpu initialisations
6042 memmap_pages = calc_memmap_size(size, realsize);
6043 if (!is_highmem_idx(j)) {
6044 if (freesize >= memmap_pages) {
6045 freesize -= memmap_pages;
6048 " %s zone: %lu pages used for memmap\n",
6049 zone_names[j], memmap_pages);
6051 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6052 zone_names[j], memmap_pages, freesize);
6055 /* Account for reserved pages */
6056 if (j == 0 && freesize > dma_reserve) {
6057 freesize -= dma_reserve;
6058 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
6059 zone_names[0], dma_reserve);
6062 if (!is_highmem_idx(j))
6063 nr_kernel_pages += freesize;
6064 /* Charge for highmem memmap if there are enough kernel pages */
6065 else if (nr_kernel_pages > memmap_pages * 2)
6066 nr_kernel_pages -= memmap_pages;
6067 nr_all_pages += freesize;
6070 * Set an approximate value for lowmem here, it will be adjusted
6071 * when the bootmem allocator frees pages into the buddy system.
6072 * And all highmem pages will be managed by the buddy system.
6074 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
6078 zone->name = zone_names[j];
6079 zone->zone_pgdat = pgdat;
6080 spin_lock_init(&zone->lock);
6081 zone_seqlock_init(zone);
6082 zone_pcp_init(zone);
6087 set_pageblock_order();
6088 setup_usemap(pgdat, zone, zone_start_pfn, size);
6089 init_currently_empty_zone(zone, zone_start_pfn, size);
6090 memmap_init(size, nid, j, zone_start_pfn);
6094 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
6096 unsigned long __maybe_unused start = 0;
6097 unsigned long __maybe_unused offset = 0;
6099 /* Skip empty nodes */
6100 if (!pgdat->node_spanned_pages)
6103 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6104 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6105 offset = pgdat->node_start_pfn - start;
6106 /* ia64 gets its own node_mem_map, before this, without bootmem */
6107 if (!pgdat->node_mem_map) {
6108 unsigned long size, end;
6112 * The zone's endpoints aren't required to be MAX_ORDER
6113 * aligned but the node_mem_map endpoints must be in order
6114 * for the buddy allocator to function correctly.
6116 end = pgdat_end_pfn(pgdat);
6117 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6118 size = (end - start) * sizeof(struct page);
6119 map = alloc_remap(pgdat->node_id, size);
6121 map = memblock_virt_alloc_node_nopanic(size,
6123 pgdat->node_mem_map = map + offset;
6125 #ifndef CONFIG_NEED_MULTIPLE_NODES
6127 * With no DISCONTIG, the global mem_map is just set as node 0's
6129 if (pgdat == NODE_DATA(0)) {
6130 mem_map = NODE_DATA(0)->node_mem_map;
6131 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6132 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6134 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6137 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6140 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
6141 unsigned long node_start_pfn, unsigned long *zholes_size)
6143 pg_data_t *pgdat = NODE_DATA(nid);
6144 unsigned long start_pfn = 0;
6145 unsigned long end_pfn = 0;
6147 /* pg_data_t should be reset to zero when it's allocated */
6148 WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
6150 pgdat->node_id = nid;
6151 pgdat->node_start_pfn = node_start_pfn;
6152 pgdat->per_cpu_nodestats = NULL;
6153 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6154 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6155 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6156 (u64)start_pfn << PAGE_SHIFT,
6157 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6159 start_pfn = node_start_pfn;
6161 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6162 zones_size, zholes_size);
6164 alloc_node_mem_map(pgdat);
6165 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6166 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6167 nid, (unsigned long)pgdat,
6168 (unsigned long)pgdat->node_mem_map);
6171 reset_deferred_meminit(pgdat);
6172 free_area_init_core(pgdat);
6175 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6177 #if MAX_NUMNODES > 1
6179 * Figure out the number of possible node ids.
6181 void __init setup_nr_node_ids(void)
6183 unsigned int highest;
6185 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
6186 nr_node_ids = highest + 1;
6191 * node_map_pfn_alignment - determine the maximum internode alignment
6193 * This function should be called after node map is populated and sorted.
6194 * It calculates the maximum power of two alignment which can distinguish
6197 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6198 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6199 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6200 * shifted, 1GiB is enough and this function will indicate so.
6202 * This is used to test whether pfn -> nid mapping of the chosen memory
6203 * model has fine enough granularity to avoid incorrect mapping for the
6204 * populated node map.
6206 * Returns the determined alignment in pfn's. 0 if there is no alignment
6207 * requirement (single node).
6209 unsigned long __init node_map_pfn_alignment(void)
6211 unsigned long accl_mask = 0, last_end = 0;
6212 unsigned long start, end, mask;
6216 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
6217 if (!start || last_nid < 0 || last_nid == nid) {
6224 * Start with a mask granular enough to pin-point to the
6225 * start pfn and tick off bits one-by-one until it becomes
6226 * too coarse to separate the current node from the last.
6228 mask = ~((1 << __ffs(start)) - 1);
6229 while (mask && last_end <= (start & (mask << 1)))
6232 /* accumulate all internode masks */
6236 /* convert mask to number of pages */
6237 return ~accl_mask + 1;
6240 /* Find the lowest pfn for a node */
6241 static unsigned long __init find_min_pfn_for_node(int nid)
6243 unsigned long min_pfn = ULONG_MAX;
6244 unsigned long start_pfn;
6247 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
6248 min_pfn = min(min_pfn, start_pfn);
6250 if (min_pfn == ULONG_MAX) {
6251 pr_warn("Could not find start_pfn for node %d\n", nid);
6259 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6261 * It returns the minimum PFN based on information provided via
6262 * memblock_set_node().
6264 unsigned long __init find_min_pfn_with_active_regions(void)
6266 return find_min_pfn_for_node(MAX_NUMNODES);
6270 * early_calculate_totalpages()
6271 * Sum pages in active regions for movable zone.
6272 * Populate N_MEMORY for calculating usable_nodes.
6274 static unsigned long __init early_calculate_totalpages(void)
6276 unsigned long totalpages = 0;
6277 unsigned long start_pfn, end_pfn;
6280 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6281 unsigned long pages = end_pfn - start_pfn;
6283 totalpages += pages;
6285 node_set_state(nid, N_MEMORY);
6291 * Find the PFN the Movable zone begins in each node. Kernel memory
6292 * is spread evenly between nodes as long as the nodes have enough
6293 * memory. When they don't, some nodes will have more kernelcore than
6296 static void __init find_zone_movable_pfns_for_nodes(void)
6299 unsigned long usable_startpfn;
6300 unsigned long kernelcore_node, kernelcore_remaining;
6301 /* save the state before borrow the nodemask */
6302 nodemask_t saved_node_state = node_states[N_MEMORY];
6303 unsigned long totalpages = early_calculate_totalpages();
6304 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6305 struct memblock_region *r;
6307 /* Need to find movable_zone earlier when movable_node is specified. */
6308 find_usable_zone_for_movable();
6311 * If movable_node is specified, ignore kernelcore and movablecore
6314 if (movable_node_is_enabled()) {
6315 for_each_memblock(memory, r) {
6316 if (!memblock_is_hotpluggable(r))
6321 usable_startpfn = PFN_DOWN(r->base);
6322 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6323 min(usable_startpfn, zone_movable_pfn[nid]) :
6331 * If kernelcore=mirror is specified, ignore movablecore option
6333 if (mirrored_kernelcore) {
6334 bool mem_below_4gb_not_mirrored = false;
6336 for_each_memblock(memory, r) {
6337 if (memblock_is_mirror(r))
6342 usable_startpfn = memblock_region_memory_base_pfn(r);
6344 if (usable_startpfn < 0x100000) {
6345 mem_below_4gb_not_mirrored = true;
6349 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6350 min(usable_startpfn, zone_movable_pfn[nid]) :
6354 if (mem_below_4gb_not_mirrored)
6355 pr_warn("This configuration results in unmirrored kernel memory.");
6361 * If movablecore=nn[KMG] was specified, calculate what size of
6362 * kernelcore that corresponds so that memory usable for
6363 * any allocation type is evenly spread. If both kernelcore
6364 * and movablecore are specified, then the value of kernelcore
6365 * will be used for required_kernelcore if it's greater than
6366 * what movablecore would have allowed.
6368 if (required_movablecore) {
6369 unsigned long corepages;
6372 * Round-up so that ZONE_MOVABLE is at least as large as what
6373 * was requested by the user
6375 required_movablecore =
6376 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6377 required_movablecore = min(totalpages, required_movablecore);
6378 corepages = totalpages - required_movablecore;
6380 required_kernelcore = max(required_kernelcore, corepages);
6384 * If kernelcore was not specified or kernelcore size is larger
6385 * than totalpages, there is no ZONE_MOVABLE.
6387 if (!required_kernelcore || required_kernelcore >= totalpages)
6390 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6391 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6394 /* Spread kernelcore memory as evenly as possible throughout nodes */
6395 kernelcore_node = required_kernelcore / usable_nodes;
6396 for_each_node_state(nid, N_MEMORY) {
6397 unsigned long start_pfn, end_pfn;
6400 * Recalculate kernelcore_node if the division per node
6401 * now exceeds what is necessary to satisfy the requested
6402 * amount of memory for the kernel
6404 if (required_kernelcore < kernelcore_node)
6405 kernelcore_node = required_kernelcore / usable_nodes;
6408 * As the map is walked, we track how much memory is usable
6409 * by the kernel using kernelcore_remaining. When it is
6410 * 0, the rest of the node is usable by ZONE_MOVABLE
6412 kernelcore_remaining = kernelcore_node;
6414 /* Go through each range of PFNs within this node */
6415 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6416 unsigned long size_pages;
6418 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6419 if (start_pfn >= end_pfn)
6422 /* Account for what is only usable for kernelcore */
6423 if (start_pfn < usable_startpfn) {
6424 unsigned long kernel_pages;
6425 kernel_pages = min(end_pfn, usable_startpfn)
6428 kernelcore_remaining -= min(kernel_pages,
6429 kernelcore_remaining);
6430 required_kernelcore -= min(kernel_pages,
6431 required_kernelcore);
6433 /* Continue if range is now fully accounted */
6434 if (end_pfn <= usable_startpfn) {
6437 * Push zone_movable_pfn to the end so
6438 * that if we have to rebalance
6439 * kernelcore across nodes, we will
6440 * not double account here
6442 zone_movable_pfn[nid] = end_pfn;
6445 start_pfn = usable_startpfn;
6449 * The usable PFN range for ZONE_MOVABLE is from
6450 * start_pfn->end_pfn. Calculate size_pages as the
6451 * number of pages used as kernelcore
6453 size_pages = end_pfn - start_pfn;
6454 if (size_pages > kernelcore_remaining)
6455 size_pages = kernelcore_remaining;
6456 zone_movable_pfn[nid] = start_pfn + size_pages;
6459 * Some kernelcore has been met, update counts and
6460 * break if the kernelcore for this node has been
6463 required_kernelcore -= min(required_kernelcore,
6465 kernelcore_remaining -= size_pages;
6466 if (!kernelcore_remaining)
6472 * If there is still required_kernelcore, we do another pass with one
6473 * less node in the count. This will push zone_movable_pfn[nid] further
6474 * along on the nodes that still have memory until kernelcore is
6478 if (usable_nodes && required_kernelcore > usable_nodes)
6482 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6483 for (nid = 0; nid < MAX_NUMNODES; nid++)
6484 zone_movable_pfn[nid] =
6485 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6488 /* restore the node_state */
6489 node_states[N_MEMORY] = saved_node_state;
6492 /* Any regular or high memory on that node ? */
6493 static void check_for_memory(pg_data_t *pgdat, int nid)
6495 enum zone_type zone_type;
6497 if (N_MEMORY == N_NORMAL_MEMORY)
6500 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6501 struct zone *zone = &pgdat->node_zones[zone_type];
6502 if (populated_zone(zone)) {
6503 node_set_state(nid, N_HIGH_MEMORY);
6504 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6505 zone_type <= ZONE_NORMAL)
6506 node_set_state(nid, N_NORMAL_MEMORY);
6513 * free_area_init_nodes - Initialise all pg_data_t and zone data
6514 * @max_zone_pfn: an array of max PFNs for each zone
6516 * This will call free_area_init_node() for each active node in the system.
6517 * Using the page ranges provided by memblock_set_node(), the size of each
6518 * zone in each node and their holes is calculated. If the maximum PFN
6519 * between two adjacent zones match, it is assumed that the zone is empty.
6520 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6521 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6522 * starts where the previous one ended. For example, ZONE_DMA32 starts
6523 * at arch_max_dma_pfn.
6525 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6527 unsigned long start_pfn, end_pfn;
6530 /* Record where the zone boundaries are */
6531 memset(arch_zone_lowest_possible_pfn, 0,
6532 sizeof(arch_zone_lowest_possible_pfn));
6533 memset(arch_zone_highest_possible_pfn, 0,
6534 sizeof(arch_zone_highest_possible_pfn));
6536 start_pfn = find_min_pfn_with_active_regions();
6538 for (i = 0; i < MAX_NR_ZONES; i++) {
6539 if (i == ZONE_MOVABLE)
6542 end_pfn = max(max_zone_pfn[i], start_pfn);
6543 arch_zone_lowest_possible_pfn[i] = start_pfn;
6544 arch_zone_highest_possible_pfn[i] = end_pfn;
6546 start_pfn = end_pfn;
6549 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6550 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6551 find_zone_movable_pfns_for_nodes();
6553 /* Print out the zone ranges */
6554 pr_info("Zone ranges:\n");
6555 for (i = 0; i < MAX_NR_ZONES; i++) {
6556 if (i == ZONE_MOVABLE)
6558 pr_info(" %-8s ", zone_names[i]);
6559 if (arch_zone_lowest_possible_pfn[i] ==
6560 arch_zone_highest_possible_pfn[i])
6563 pr_cont("[mem %#018Lx-%#018Lx]\n",
6564 (u64)arch_zone_lowest_possible_pfn[i]
6566 ((u64)arch_zone_highest_possible_pfn[i]
6567 << PAGE_SHIFT) - 1);
6570 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6571 pr_info("Movable zone start for each node\n");
6572 for (i = 0; i < MAX_NUMNODES; i++) {
6573 if (zone_movable_pfn[i])
6574 pr_info(" Node %d: %#018Lx\n", i,
6575 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6578 /* Print out the early node map */
6579 pr_info("Early memory node ranges\n");
6580 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6581 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6582 (u64)start_pfn << PAGE_SHIFT,
6583 ((u64)end_pfn << PAGE_SHIFT) - 1);
6585 /* Initialise every node */
6586 mminit_verify_pageflags_layout();
6587 setup_nr_node_ids();
6588 for_each_online_node(nid) {
6589 pg_data_t *pgdat = NODE_DATA(nid);
6590 free_area_init_node(nid, NULL,
6591 find_min_pfn_for_node(nid), NULL);
6593 /* Any memory on that node */
6594 if (pgdat->node_present_pages)
6595 node_set_state(nid, N_MEMORY);
6596 check_for_memory(pgdat, nid);
6600 static int __init cmdline_parse_core(char *p, unsigned long *core)
6602 unsigned long long coremem;
6606 coremem = memparse(p, &p);
6607 *core = coremem >> PAGE_SHIFT;
6609 /* Paranoid check that UL is enough for the coremem value */
6610 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6616 * kernelcore=size sets the amount of memory for use for allocations that
6617 * cannot be reclaimed or migrated.
6619 static int __init cmdline_parse_kernelcore(char *p)
6621 /* parse kernelcore=mirror */
6622 if (parse_option_str(p, "mirror")) {
6623 mirrored_kernelcore = true;
6627 return cmdline_parse_core(p, &required_kernelcore);
6631 * movablecore=size sets the amount of memory for use for allocations that
6632 * can be reclaimed or migrated.
6634 static int __init cmdline_parse_movablecore(char *p)
6636 return cmdline_parse_core(p, &required_movablecore);
6639 early_param("kernelcore", cmdline_parse_kernelcore);
6640 early_param("movablecore", cmdline_parse_movablecore);
6642 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6644 void adjust_managed_page_count(struct page *page, long count)
6646 spin_lock(&managed_page_count_lock);
6647 page_zone(page)->managed_pages += count;
6648 totalram_pages += count;
6649 #ifdef CONFIG_HIGHMEM
6650 if (PageHighMem(page))
6651 totalhigh_pages += count;
6653 spin_unlock(&managed_page_count_lock);
6655 EXPORT_SYMBOL(adjust_managed_page_count);
6657 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6660 unsigned long pages = 0;
6662 start = (void *)PAGE_ALIGN((unsigned long)start);
6663 end = (void *)((unsigned long)end & PAGE_MASK);
6664 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6665 if ((unsigned int)poison <= 0xFF)
6666 memset(pos, poison, PAGE_SIZE);
6667 free_reserved_page(virt_to_page(pos));
6671 pr_info("Freeing %s memory: %ldK\n",
6672 s, pages << (PAGE_SHIFT - 10));
6676 EXPORT_SYMBOL(free_reserved_area);
6678 #ifdef CONFIG_HIGHMEM
6679 void free_highmem_page(struct page *page)
6681 __free_reserved_page(page);
6683 page_zone(page)->managed_pages++;
6689 void __init mem_init_print_info(const char *str)
6691 unsigned long physpages, codesize, datasize, rosize, bss_size;
6692 unsigned long init_code_size, init_data_size;
6694 physpages = get_num_physpages();
6695 codesize = _etext - _stext;
6696 datasize = _edata - _sdata;
6697 rosize = __end_rodata - __start_rodata;
6698 bss_size = __bss_stop - __bss_start;
6699 init_data_size = __init_end - __init_begin;
6700 init_code_size = _einittext - _sinittext;
6703 * Detect special cases and adjust section sizes accordingly:
6704 * 1) .init.* may be embedded into .data sections
6705 * 2) .init.text.* may be out of [__init_begin, __init_end],
6706 * please refer to arch/tile/kernel/vmlinux.lds.S.
6707 * 3) .rodata.* may be embedded into .text or .data sections.
6709 #define adj_init_size(start, end, size, pos, adj) \
6711 if (start <= pos && pos < end && size > adj) \
6715 adj_init_size(__init_begin, __init_end, init_data_size,
6716 _sinittext, init_code_size);
6717 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6718 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6719 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6720 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6722 #undef adj_init_size
6724 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6725 #ifdef CONFIG_HIGHMEM
6729 nr_free_pages() << (PAGE_SHIFT - 10),
6730 physpages << (PAGE_SHIFT - 10),
6731 codesize >> 10, datasize >> 10, rosize >> 10,
6732 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6733 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6734 totalcma_pages << (PAGE_SHIFT - 10),
6735 #ifdef CONFIG_HIGHMEM
6736 totalhigh_pages << (PAGE_SHIFT - 10),
6738 str ? ", " : "", str ? str : "");
6742 * set_dma_reserve - set the specified number of pages reserved in the first zone
6743 * @new_dma_reserve: The number of pages to mark reserved
6745 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6746 * In the DMA zone, a significant percentage may be consumed by kernel image
6747 * and other unfreeable allocations which can skew the watermarks badly. This
6748 * function may optionally be used to account for unfreeable pages in the
6749 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6750 * smaller per-cpu batchsize.
6752 void __init set_dma_reserve(unsigned long new_dma_reserve)
6754 dma_reserve = new_dma_reserve;
6757 void __init free_area_init(unsigned long *zones_size)
6759 free_area_init_node(0, zones_size,
6760 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6763 static int page_alloc_cpu_dead(unsigned int cpu)
6766 lru_add_drain_cpu(cpu);
6770 * Spill the event counters of the dead processor
6771 * into the current processors event counters.
6772 * This artificially elevates the count of the current
6775 vm_events_fold_cpu(cpu);
6778 * Zero the differential counters of the dead processor
6779 * so that the vm statistics are consistent.
6781 * This is only okay since the processor is dead and cannot
6782 * race with what we are doing.
6784 cpu_vm_stats_fold(cpu);
6788 void __init page_alloc_init(void)
6792 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD,
6793 "mm/page_alloc:dead", NULL,
6794 page_alloc_cpu_dead);
6799 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6800 * or min_free_kbytes changes.
6802 static void calculate_totalreserve_pages(void)
6804 struct pglist_data *pgdat;
6805 unsigned long reserve_pages = 0;
6806 enum zone_type i, j;
6808 for_each_online_pgdat(pgdat) {
6810 pgdat->totalreserve_pages = 0;
6812 for (i = 0; i < MAX_NR_ZONES; i++) {
6813 struct zone *zone = pgdat->node_zones + i;
6816 /* Find valid and maximum lowmem_reserve in the zone */
6817 for (j = i; j < MAX_NR_ZONES; j++) {
6818 if (zone->lowmem_reserve[j] > max)
6819 max = zone->lowmem_reserve[j];
6822 /* we treat the high watermark as reserved pages. */
6823 max += high_wmark_pages(zone);
6825 if (max > zone->managed_pages)
6826 max = zone->managed_pages;
6828 pgdat->totalreserve_pages += max;
6830 reserve_pages += max;
6833 totalreserve_pages = reserve_pages;
6837 * setup_per_zone_lowmem_reserve - called whenever
6838 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6839 * has a correct pages reserved value, so an adequate number of
6840 * pages are left in the zone after a successful __alloc_pages().
6842 static void setup_per_zone_lowmem_reserve(void)
6844 struct pglist_data *pgdat;
6845 enum zone_type j, idx;
6847 for_each_online_pgdat(pgdat) {
6848 for (j = 0; j < MAX_NR_ZONES; j++) {
6849 struct zone *zone = pgdat->node_zones + j;
6850 unsigned long managed_pages = zone->managed_pages;
6852 zone->lowmem_reserve[j] = 0;
6856 struct zone *lower_zone;
6860 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6861 sysctl_lowmem_reserve_ratio[idx] = 1;
6863 lower_zone = pgdat->node_zones + idx;
6864 lower_zone->lowmem_reserve[j] = managed_pages /
6865 sysctl_lowmem_reserve_ratio[idx];
6866 managed_pages += lower_zone->managed_pages;
6871 /* update totalreserve_pages */
6872 calculate_totalreserve_pages();
6875 static void __setup_per_zone_wmarks(void)
6877 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6878 unsigned long lowmem_pages = 0;
6880 unsigned long flags;
6882 /* Calculate total number of !ZONE_HIGHMEM pages */
6883 for_each_zone(zone) {
6884 if (!is_highmem(zone))
6885 lowmem_pages += zone->managed_pages;
6888 for_each_zone(zone) {
6891 spin_lock_irqsave(&zone->lock, flags);
6892 tmp = (u64)pages_min * zone->managed_pages;
6893 do_div(tmp, lowmem_pages);
6894 if (is_highmem(zone)) {
6896 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6897 * need highmem pages, so cap pages_min to a small
6900 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6901 * deltas control asynch page reclaim, and so should
6902 * not be capped for highmem.
6904 unsigned long min_pages;
6906 min_pages = zone->managed_pages / 1024;
6907 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6908 zone->watermark[WMARK_MIN] = min_pages;
6911 * If it's a lowmem zone, reserve a number of pages
6912 * proportionate to the zone's size.
6914 zone->watermark[WMARK_MIN] = tmp;
6918 * Set the kswapd watermarks distance according to the
6919 * scale factor in proportion to available memory, but
6920 * ensure a minimum size on small systems.
6922 tmp = max_t(u64, tmp >> 2,
6923 mult_frac(zone->managed_pages,
6924 watermark_scale_factor, 10000));
6926 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6927 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6929 spin_unlock_irqrestore(&zone->lock, flags);
6932 /* update totalreserve_pages */
6933 calculate_totalreserve_pages();
6937 * setup_per_zone_wmarks - called when min_free_kbytes changes
6938 * or when memory is hot-{added|removed}
6940 * Ensures that the watermark[min,low,high] values for each zone are set
6941 * correctly with respect to min_free_kbytes.
6943 void setup_per_zone_wmarks(void)
6945 mutex_lock(&zonelists_mutex);
6946 __setup_per_zone_wmarks();
6947 mutex_unlock(&zonelists_mutex);
6951 * Initialise min_free_kbytes.
6953 * For small machines we want it small (128k min). For large machines
6954 * we want it large (64MB max). But it is not linear, because network
6955 * bandwidth does not increase linearly with machine size. We use
6957 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6958 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6974 int __meminit init_per_zone_wmark_min(void)
6976 unsigned long lowmem_kbytes;
6977 int new_min_free_kbytes;
6979 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6980 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6982 if (new_min_free_kbytes > user_min_free_kbytes) {
6983 min_free_kbytes = new_min_free_kbytes;
6984 if (min_free_kbytes < 128)
6985 min_free_kbytes = 128;
6986 if (min_free_kbytes > 65536)
6987 min_free_kbytes = 65536;
6989 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6990 new_min_free_kbytes, user_min_free_kbytes);
6992 setup_per_zone_wmarks();
6993 refresh_zone_stat_thresholds();
6994 setup_per_zone_lowmem_reserve();
6997 setup_min_unmapped_ratio();
6998 setup_min_slab_ratio();
7003 core_initcall(init_per_zone_wmark_min)
7006 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7007 * that we can call two helper functions whenever min_free_kbytes
7010 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
7011 void __user *buffer, size_t *length, loff_t *ppos)
7015 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7020 user_min_free_kbytes = min_free_kbytes;
7021 setup_per_zone_wmarks();
7026 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
7027 void __user *buffer, size_t *length, loff_t *ppos)
7031 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7036 setup_per_zone_wmarks();
7042 static void setup_min_unmapped_ratio(void)
7047 for_each_online_pgdat(pgdat)
7048 pgdat->min_unmapped_pages = 0;
7051 zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
7052 sysctl_min_unmapped_ratio) / 100;
7056 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
7057 void __user *buffer, size_t *length, loff_t *ppos)
7061 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7065 setup_min_unmapped_ratio();
7070 static void setup_min_slab_ratio(void)
7075 for_each_online_pgdat(pgdat)
7076 pgdat->min_slab_pages = 0;
7079 zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
7080 sysctl_min_slab_ratio) / 100;
7083 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
7084 void __user *buffer, size_t *length, loff_t *ppos)
7088 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7092 setup_min_slab_ratio();
7099 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7100 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7101 * whenever sysctl_lowmem_reserve_ratio changes.
7103 * The reserve ratio obviously has absolutely no relation with the
7104 * minimum watermarks. The lowmem reserve ratio can only make sense
7105 * if in function of the boot time zone sizes.
7107 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
7108 void __user *buffer, size_t *length, loff_t *ppos)
7110 proc_dointvec_minmax(table, write, buffer, length, ppos);
7111 setup_per_zone_lowmem_reserve();
7116 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7117 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7118 * pagelist can have before it gets flushed back to buddy allocator.
7120 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
7121 void __user *buffer, size_t *length, loff_t *ppos)
7124 int old_percpu_pagelist_fraction;
7127 mutex_lock(&pcp_batch_high_lock);
7128 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
7130 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
7131 if (!write || ret < 0)
7134 /* Sanity checking to avoid pcp imbalance */
7135 if (percpu_pagelist_fraction &&
7136 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
7137 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
7143 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
7146 for_each_populated_zone(zone) {
7149 for_each_possible_cpu(cpu)
7150 pageset_set_high_and_batch(zone,
7151 per_cpu_ptr(zone->pageset, cpu));
7154 mutex_unlock(&pcp_batch_high_lock);
7159 int hashdist = HASHDIST_DEFAULT;
7161 static int __init set_hashdist(char *str)
7165 hashdist = simple_strtoul(str, &str, 0);
7168 __setup("hashdist=", set_hashdist);
7171 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7173 * Returns the number of pages that arch has reserved but
7174 * is not known to alloc_large_system_hash().
7176 static unsigned long __init arch_reserved_kernel_pages(void)
7183 * allocate a large system hash table from bootmem
7184 * - it is assumed that the hash table must contain an exact power-of-2
7185 * quantity of entries
7186 * - limit is the number of hash buckets, not the total allocation size
7188 void *__init alloc_large_system_hash(const char *tablename,
7189 unsigned long bucketsize,
7190 unsigned long numentries,
7193 unsigned int *_hash_shift,
7194 unsigned int *_hash_mask,
7195 unsigned long low_limit,
7196 unsigned long high_limit)
7198 unsigned long long max = high_limit;
7199 unsigned long log2qty, size;
7203 /* allow the kernel cmdline to have a say */
7205 /* round applicable memory size up to nearest megabyte */
7206 numentries = nr_kernel_pages;
7207 numentries -= arch_reserved_kernel_pages();
7209 /* It isn't necessary when PAGE_SIZE >= 1MB */
7210 if (PAGE_SHIFT < 20)
7211 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
7213 /* limit to 1 bucket per 2^scale bytes of low memory */
7214 if (scale > PAGE_SHIFT)
7215 numentries >>= (scale - PAGE_SHIFT);
7217 numentries <<= (PAGE_SHIFT - scale);
7219 /* Make sure we've got at least a 0-order allocation.. */
7220 if (unlikely(flags & HASH_SMALL)) {
7221 /* Makes no sense without HASH_EARLY */
7222 WARN_ON(!(flags & HASH_EARLY));
7223 if (!(numentries >> *_hash_shift)) {
7224 numentries = 1UL << *_hash_shift;
7225 BUG_ON(!numentries);
7227 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
7228 numentries = PAGE_SIZE / bucketsize;
7230 numentries = roundup_pow_of_two(numentries);
7232 /* limit allocation size to 1/16 total memory by default */
7234 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
7235 do_div(max, bucketsize);
7237 max = min(max, 0x80000000ULL);
7239 if (numentries < low_limit)
7240 numentries = low_limit;
7241 if (numentries > max)
7244 log2qty = ilog2(numentries);
7247 * memblock allocator returns zeroed memory already, so HASH_ZERO is
7248 * currently not used when HASH_EARLY is specified.
7250 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
7252 size = bucketsize << log2qty;
7253 if (flags & HASH_EARLY)
7254 table = memblock_virt_alloc_nopanic(size, 0);
7256 table = __vmalloc(size, gfp_flags, PAGE_KERNEL);
7259 * If bucketsize is not a power-of-two, we may free
7260 * some pages at the end of hash table which
7261 * alloc_pages_exact() automatically does
7263 if (get_order(size) < MAX_ORDER) {
7264 table = alloc_pages_exact(size, gfp_flags);
7265 kmemleak_alloc(table, size, 1, gfp_flags);
7268 } while (!table && size > PAGE_SIZE && --log2qty);
7271 panic("Failed to allocate %s hash table\n", tablename);
7273 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7274 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7277 *_hash_shift = log2qty;
7279 *_hash_mask = (1 << log2qty) - 1;
7285 * This function checks whether pageblock includes unmovable pages or not.
7286 * If @count is not zero, it is okay to include less @count unmovable pages
7288 * PageLRU check without isolation or lru_lock could race so that
7289 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7290 * check without lock_page also may miss some movable non-lru pages at
7291 * race condition. So you can't expect this function should be exact.
7293 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7294 bool skip_hwpoisoned_pages)
7296 unsigned long pfn, iter, found;
7300 * For avoiding noise data, lru_add_drain_all() should be called
7301 * If ZONE_MOVABLE, the zone never contains unmovable pages
7303 if (zone_idx(zone) == ZONE_MOVABLE)
7305 mt = get_pageblock_migratetype(page);
7306 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
7309 pfn = page_to_pfn(page);
7310 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7311 unsigned long check = pfn + iter;
7313 if (!pfn_valid_within(check))
7316 page = pfn_to_page(check);
7319 * Hugepages are not in LRU lists, but they're movable.
7320 * We need not scan over tail pages bacause we don't
7321 * handle each tail page individually in migration.
7323 if (PageHuge(page)) {
7324 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7329 * We can't use page_count without pin a page
7330 * because another CPU can free compound page.
7331 * This check already skips compound tails of THP
7332 * because their page->_refcount is zero at all time.
7334 if (!page_ref_count(page)) {
7335 if (PageBuddy(page))
7336 iter += (1 << page_order(page)) - 1;
7341 * The HWPoisoned page may be not in buddy system, and
7342 * page_count() is not 0.
7344 if (skip_hwpoisoned_pages && PageHWPoison(page))
7347 if (__PageMovable(page))
7353 * If there are RECLAIMABLE pages, we need to check
7354 * it. But now, memory offline itself doesn't call
7355 * shrink_node_slabs() and it still to be fixed.
7358 * If the page is not RAM, page_count()should be 0.
7359 * we don't need more check. This is an _used_ not-movable page.
7361 * The problematic thing here is PG_reserved pages. PG_reserved
7362 * is set to both of a memory hole page and a _used_ kernel
7371 bool is_pageblock_removable_nolock(struct page *page)
7377 * We have to be careful here because we are iterating over memory
7378 * sections which are not zone aware so we might end up outside of
7379 * the zone but still within the section.
7380 * We have to take care about the node as well. If the node is offline
7381 * its NODE_DATA will be NULL - see page_zone.
7383 if (!node_online(page_to_nid(page)))
7386 zone = page_zone(page);
7387 pfn = page_to_pfn(page);
7388 if (!zone_spans_pfn(zone, pfn))
7391 return !has_unmovable_pages(zone, page, 0, true);
7394 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7396 static unsigned long pfn_max_align_down(unsigned long pfn)
7398 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7399 pageblock_nr_pages) - 1);
7402 static unsigned long pfn_max_align_up(unsigned long pfn)
7404 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7405 pageblock_nr_pages));
7408 /* [start, end) must belong to a single zone. */
7409 static int __alloc_contig_migrate_range(struct compact_control *cc,
7410 unsigned long start, unsigned long end)
7412 /* This function is based on compact_zone() from compaction.c. */
7413 unsigned long nr_reclaimed;
7414 unsigned long pfn = start;
7415 unsigned int tries = 0;
7420 while (pfn < end || !list_empty(&cc->migratepages)) {
7421 if (fatal_signal_pending(current)) {
7426 if (list_empty(&cc->migratepages)) {
7427 cc->nr_migratepages = 0;
7428 pfn = isolate_migratepages_range(cc, pfn, end);
7434 } else if (++tries == 5) {
7435 ret = ret < 0 ? ret : -EBUSY;
7439 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7441 cc->nr_migratepages -= nr_reclaimed;
7443 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7444 NULL, 0, cc->mode, MR_CMA);
7447 putback_movable_pages(&cc->migratepages);
7454 * alloc_contig_range() -- tries to allocate given range of pages
7455 * @start: start PFN to allocate
7456 * @end: one-past-the-last PFN to allocate
7457 * @migratetype: migratetype of the underlaying pageblocks (either
7458 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7459 * in range must have the same migratetype and it must
7460 * be either of the two.
7461 * @gfp_mask: GFP mask to use during compaction
7463 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7464 * aligned, however it's the caller's responsibility to guarantee that
7465 * we are the only thread that changes migrate type of pageblocks the
7468 * The PFN range must belong to a single zone.
7470 * Returns zero on success or negative error code. On success all
7471 * pages which PFN is in [start, end) are allocated for the caller and
7472 * need to be freed with free_contig_range().
7474 int alloc_contig_range(unsigned long start, unsigned long end,
7475 unsigned migratetype, gfp_t gfp_mask)
7477 unsigned long outer_start, outer_end;
7481 struct compact_control cc = {
7482 .nr_migratepages = 0,
7484 .zone = page_zone(pfn_to_page(start)),
7485 .mode = MIGRATE_SYNC,
7486 .ignore_skip_hint = true,
7487 .gfp_mask = current_gfp_context(gfp_mask),
7489 INIT_LIST_HEAD(&cc.migratepages);
7492 * What we do here is we mark all pageblocks in range as
7493 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7494 * have different sizes, and due to the way page allocator
7495 * work, we align the range to biggest of the two pages so
7496 * that page allocator won't try to merge buddies from
7497 * different pageblocks and change MIGRATE_ISOLATE to some
7498 * other migration type.
7500 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7501 * migrate the pages from an unaligned range (ie. pages that
7502 * we are interested in). This will put all the pages in
7503 * range back to page allocator as MIGRATE_ISOLATE.
7505 * When this is done, we take the pages in range from page
7506 * allocator removing them from the buddy system. This way
7507 * page allocator will never consider using them.
7509 * This lets us mark the pageblocks back as
7510 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7511 * aligned range but not in the unaligned, original range are
7512 * put back to page allocator so that buddy can use them.
7515 ret = start_isolate_page_range(pfn_max_align_down(start),
7516 pfn_max_align_up(end), migratetype,
7522 * In case of -EBUSY, we'd like to know which page causes problem.
7523 * So, just fall through. We will check it in test_pages_isolated().
7525 ret = __alloc_contig_migrate_range(&cc, start, end);
7526 if (ret && ret != -EBUSY)
7530 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7531 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7532 * more, all pages in [start, end) are free in page allocator.
7533 * What we are going to do is to allocate all pages from
7534 * [start, end) (that is remove them from page allocator).
7536 * The only problem is that pages at the beginning and at the
7537 * end of interesting range may be not aligned with pages that
7538 * page allocator holds, ie. they can be part of higher order
7539 * pages. Because of this, we reserve the bigger range and
7540 * once this is done free the pages we are not interested in.
7542 * We don't have to hold zone->lock here because the pages are
7543 * isolated thus they won't get removed from buddy.
7546 lru_add_drain_all();
7547 drain_all_pages(cc.zone);
7550 outer_start = start;
7551 while (!PageBuddy(pfn_to_page(outer_start))) {
7552 if (++order >= MAX_ORDER) {
7553 outer_start = start;
7556 outer_start &= ~0UL << order;
7559 if (outer_start != start) {
7560 order = page_order(pfn_to_page(outer_start));
7563 * outer_start page could be small order buddy page and
7564 * it doesn't include start page. Adjust outer_start
7565 * in this case to report failed page properly
7566 * on tracepoint in test_pages_isolated()
7568 if (outer_start + (1UL << order) <= start)
7569 outer_start = start;
7572 /* Make sure the range is really isolated. */
7573 if (test_pages_isolated(outer_start, end, false)) {
7574 pr_info("%s: [%lx, %lx) PFNs busy\n",
7575 __func__, outer_start, end);
7580 /* Grab isolated pages from freelists. */
7581 outer_end = isolate_freepages_range(&cc, outer_start, end);
7587 /* Free head and tail (if any) */
7588 if (start != outer_start)
7589 free_contig_range(outer_start, start - outer_start);
7590 if (end != outer_end)
7591 free_contig_range(end, outer_end - end);
7594 undo_isolate_page_range(pfn_max_align_down(start),
7595 pfn_max_align_up(end), migratetype);
7599 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7601 unsigned int count = 0;
7603 for (; nr_pages--; pfn++) {
7604 struct page *page = pfn_to_page(pfn);
7606 count += page_count(page) != 1;
7609 WARN(count != 0, "%d pages are still in use!\n", count);
7613 #ifdef CONFIG_MEMORY_HOTPLUG
7615 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7616 * page high values need to be recalulated.
7618 void __meminit zone_pcp_update(struct zone *zone)
7621 mutex_lock(&pcp_batch_high_lock);
7622 for_each_possible_cpu(cpu)
7623 pageset_set_high_and_batch(zone,
7624 per_cpu_ptr(zone->pageset, cpu));
7625 mutex_unlock(&pcp_batch_high_lock);
7629 void zone_pcp_reset(struct zone *zone)
7631 unsigned long flags;
7633 struct per_cpu_pageset *pset;
7635 /* avoid races with drain_pages() */
7636 local_irq_save(flags);
7637 if (zone->pageset != &boot_pageset) {
7638 for_each_online_cpu(cpu) {
7639 pset = per_cpu_ptr(zone->pageset, cpu);
7640 drain_zonestat(zone, pset);
7642 free_percpu(zone->pageset);
7643 zone->pageset = &boot_pageset;
7645 local_irq_restore(flags);
7648 #ifdef CONFIG_MEMORY_HOTREMOVE
7650 * All pages in the range must be in a single zone and isolated
7651 * before calling this.
7654 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7658 unsigned int order, i;
7660 unsigned long flags;
7661 /* find the first valid pfn */
7662 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7667 offline_mem_sections(pfn, end_pfn);
7668 zone = page_zone(pfn_to_page(pfn));
7669 spin_lock_irqsave(&zone->lock, flags);
7671 while (pfn < end_pfn) {
7672 if (!pfn_valid(pfn)) {
7676 page = pfn_to_page(pfn);
7678 * The HWPoisoned page may be not in buddy system, and
7679 * page_count() is not 0.
7681 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7683 SetPageReserved(page);
7687 BUG_ON(page_count(page));
7688 BUG_ON(!PageBuddy(page));
7689 order = page_order(page);
7690 #ifdef CONFIG_DEBUG_VM
7691 pr_info("remove from free list %lx %d %lx\n",
7692 pfn, 1 << order, end_pfn);
7694 list_del(&page->lru);
7695 rmv_page_order(page);
7696 zone->free_area[order].nr_free--;
7697 for (i = 0; i < (1 << order); i++)
7698 SetPageReserved((page+i));
7699 pfn += (1 << order);
7701 spin_unlock_irqrestore(&zone->lock, flags);
7705 bool is_free_buddy_page(struct page *page)
7707 struct zone *zone = page_zone(page);
7708 unsigned long pfn = page_to_pfn(page);
7709 unsigned long flags;
7712 spin_lock_irqsave(&zone->lock, flags);
7713 for (order = 0; order < MAX_ORDER; order++) {
7714 struct page *page_head = page - (pfn & ((1 << order) - 1));
7716 if (PageBuddy(page_head) && page_order(page_head) >= order)
7719 spin_unlock_irqrestore(&zone->lock, flags);
7721 return order < MAX_ORDER;