1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/mm/page_alloc.c
5 * Manages the free list, the system allocates free pages here.
6 * Note that kmalloc() lives in slab.c
8 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
9 * Swap reorganised 29.12.95, Stephen Tweedie
10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
11 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
12 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
13 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
14 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
15 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
18 #include <linux/stddef.h>
20 #include <linux/highmem.h>
21 #include <linux/swap.h>
22 #include <linux/interrupt.h>
23 #include <linux/pagemap.h>
24 #include <linux/jiffies.h>
25 #include <linux/memblock.h>
26 #include <linux/compiler.h>
27 #include <linux/kernel.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/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/memremap.h>
46 #include <linux/stop_machine.h>
47 #include <linux/random.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/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <trace/events/oom.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/sched/mm.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66 #include <linux/memcontrol.h>
67 #include <linux/ftrace.h>
68 #include <linux/lockdep.h>
69 #include <linux/nmi.h>
70 #include <linux/psi.h>
72 #include <asm/sections.h>
73 #include <asm/tlbflush.h>
74 #include <asm/div64.h>
77 #include "page_reporting.h"
79 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
80 static DEFINE_MUTEX(pcp_batch_high_lock);
81 #define MIN_PERCPU_PAGELIST_FRACTION (8)
83 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
84 DEFINE_PER_CPU(int, numa_node);
85 EXPORT_PER_CPU_SYMBOL(numa_node);
88 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
90 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
92 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
93 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
94 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
95 * defined in <linux/topology.h>.
97 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
98 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
101 /* work_structs for global per-cpu drains */
104 struct work_struct work;
106 DEFINE_MUTEX(pcpu_drain_mutex);
107 DEFINE_PER_CPU(struct pcpu_drain, pcpu_drain);
109 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
110 volatile unsigned long latent_entropy __latent_entropy;
111 EXPORT_SYMBOL(latent_entropy);
115 * Array of node states.
117 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
118 [N_POSSIBLE] = NODE_MASK_ALL,
119 [N_ONLINE] = { { [0] = 1UL } },
121 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
122 #ifdef CONFIG_HIGHMEM
123 [N_HIGH_MEMORY] = { { [0] = 1UL } },
125 [N_MEMORY] = { { [0] = 1UL } },
126 [N_CPU] = { { [0] = 1UL } },
129 EXPORT_SYMBOL(node_states);
131 atomic_long_t _totalram_pages __read_mostly;
132 EXPORT_SYMBOL(_totalram_pages);
133 unsigned long totalreserve_pages __read_mostly;
134 unsigned long totalcma_pages __read_mostly;
136 int percpu_pagelist_fraction;
137 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
138 #ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
139 DEFINE_STATIC_KEY_TRUE(init_on_alloc);
141 DEFINE_STATIC_KEY_FALSE(init_on_alloc);
143 EXPORT_SYMBOL(init_on_alloc);
145 #ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
146 DEFINE_STATIC_KEY_TRUE(init_on_free);
148 DEFINE_STATIC_KEY_FALSE(init_on_free);
150 EXPORT_SYMBOL(init_on_free);
152 static int __init early_init_on_alloc(char *buf)
159 ret = kstrtobool(buf, &bool_result);
160 if (bool_result && page_poisoning_enabled())
161 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_alloc\n");
163 static_branch_enable(&init_on_alloc);
165 static_branch_disable(&init_on_alloc);
168 early_param("init_on_alloc", early_init_on_alloc);
170 static int __init early_init_on_free(char *buf)
177 ret = kstrtobool(buf, &bool_result);
178 if (bool_result && page_poisoning_enabled())
179 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_free\n");
181 static_branch_enable(&init_on_free);
183 static_branch_disable(&init_on_free);
186 early_param("init_on_free", early_init_on_free);
189 * A cached value of the page's pageblock's migratetype, used when the page is
190 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
191 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
192 * Also the migratetype set in the page does not necessarily match the pcplist
193 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
194 * other index - this ensures that it will be put on the correct CMA freelist.
196 static inline int get_pcppage_migratetype(struct page *page)
201 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
203 page->index = migratetype;
206 #ifdef CONFIG_PM_SLEEP
208 * The following functions are used by the suspend/hibernate code to temporarily
209 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
210 * while devices are suspended. To avoid races with the suspend/hibernate code,
211 * they should always be called with system_transition_mutex held
212 * (gfp_allowed_mask also should only be modified with system_transition_mutex
213 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
214 * with that modification).
217 static gfp_t saved_gfp_mask;
219 void pm_restore_gfp_mask(void)
221 WARN_ON(!mutex_is_locked(&system_transition_mutex));
222 if (saved_gfp_mask) {
223 gfp_allowed_mask = saved_gfp_mask;
228 void pm_restrict_gfp_mask(void)
230 WARN_ON(!mutex_is_locked(&system_transition_mutex));
231 WARN_ON(saved_gfp_mask);
232 saved_gfp_mask = gfp_allowed_mask;
233 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
236 bool pm_suspended_storage(void)
238 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
242 #endif /* CONFIG_PM_SLEEP */
244 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
245 unsigned int pageblock_order __read_mostly;
248 static void __free_pages_ok(struct page *page, unsigned int order);
251 * results with 256, 32 in the lowmem_reserve sysctl:
252 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
253 * 1G machine -> (16M dma, 784M normal, 224M high)
254 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
255 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
256 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
258 * TBD: should special case ZONE_DMA32 machines here - in those we normally
259 * don't need any ZONE_NORMAL reservation
261 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
262 #ifdef CONFIG_ZONE_DMA
265 #ifdef CONFIG_ZONE_DMA32
269 #ifdef CONFIG_HIGHMEM
275 static char * const zone_names[MAX_NR_ZONES] = {
276 #ifdef CONFIG_ZONE_DMA
279 #ifdef CONFIG_ZONE_DMA32
283 #ifdef CONFIG_HIGHMEM
287 #ifdef CONFIG_ZONE_DEVICE
292 const char * const migratetype_names[MIGRATE_TYPES] = {
300 #ifdef CONFIG_MEMORY_ISOLATION
305 compound_page_dtor * const compound_page_dtors[] = {
308 #ifdef CONFIG_HUGETLB_PAGE
311 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
316 int min_free_kbytes = 1024;
317 int user_min_free_kbytes = -1;
318 #ifdef CONFIG_DISCONTIGMEM
320 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
321 * are not on separate NUMA nodes. Functionally this works but with
322 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
323 * quite small. By default, do not boost watermarks on discontigmem as in
324 * many cases very high-order allocations like THP are likely to be
325 * unsupported and the premature reclaim offsets the advantage of long-term
326 * fragmentation avoidance.
328 int watermark_boost_factor __read_mostly;
330 int watermark_boost_factor __read_mostly = 15000;
332 int watermark_scale_factor = 10;
334 static unsigned long nr_kernel_pages __initdata;
335 static unsigned long nr_all_pages __initdata;
336 static unsigned long dma_reserve __initdata;
338 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
339 static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata;
340 static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata;
341 static unsigned long required_kernelcore __initdata;
342 static unsigned long required_kernelcore_percent __initdata;
343 static unsigned long required_movablecore __initdata;
344 static unsigned long required_movablecore_percent __initdata;
345 static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
346 static bool mirrored_kernelcore __meminitdata;
348 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
350 EXPORT_SYMBOL(movable_zone);
351 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
354 unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
355 unsigned int nr_online_nodes __read_mostly = 1;
356 EXPORT_SYMBOL(nr_node_ids);
357 EXPORT_SYMBOL(nr_online_nodes);
360 int page_group_by_mobility_disabled __read_mostly;
362 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
364 * During boot we initialize deferred pages on-demand, as needed, but once
365 * page_alloc_init_late() has finished, the deferred pages are all initialized,
366 * and we can permanently disable that path.
368 static DEFINE_STATIC_KEY_TRUE(deferred_pages);
371 * Calling kasan_free_pages() only after deferred memory initialization
372 * has completed. Poisoning pages during deferred memory init will greatly
373 * lengthen the process and cause problem in large memory systems as the
374 * deferred pages initialization is done with interrupt disabled.
376 * Assuming that there will be no reference to those newly initialized
377 * pages before they are ever allocated, this should have no effect on
378 * KASAN memory tracking as the poison will be properly inserted at page
379 * allocation time. The only corner case is when pages are allocated by
380 * on-demand allocation and then freed again before the deferred pages
381 * initialization is done, but this is not likely to happen.
383 static inline void kasan_free_nondeferred_pages(struct page *page, int order)
385 if (!static_branch_unlikely(&deferred_pages))
386 kasan_free_pages(page, order);
389 /* Returns true if the struct page for the pfn is uninitialised */
390 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
392 int nid = early_pfn_to_nid(pfn);
394 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
401 * Returns true when the remaining initialisation should be deferred until
402 * later in the boot cycle when it can be parallelised.
404 static bool __meminit
405 defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
407 static unsigned long prev_end_pfn, nr_initialised;
410 * prev_end_pfn static that contains the end of previous zone
411 * No need to protect because called very early in boot before smp_init.
413 if (prev_end_pfn != end_pfn) {
414 prev_end_pfn = end_pfn;
418 /* Always populate low zones for address-constrained allocations */
419 if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
423 * We start only with one section of pages, more pages are added as
424 * needed until the rest of deferred pages are initialized.
427 if ((nr_initialised > PAGES_PER_SECTION) &&
428 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
429 NODE_DATA(nid)->first_deferred_pfn = pfn;
435 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
437 static inline bool early_page_uninitialised(unsigned long pfn)
442 static inline bool defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
448 /* Return a pointer to the bitmap storing bits affecting a block of pages */
449 static inline unsigned long *get_pageblock_bitmap(struct page *page,
452 #ifdef CONFIG_SPARSEMEM
453 return section_to_usemap(__pfn_to_section(pfn));
455 return page_zone(page)->pageblock_flags;
456 #endif /* CONFIG_SPARSEMEM */
459 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
461 #ifdef CONFIG_SPARSEMEM
462 pfn &= (PAGES_PER_SECTION-1);
463 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
465 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
466 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
467 #endif /* CONFIG_SPARSEMEM */
471 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
472 * @page: The page within the block of interest
473 * @pfn: The target page frame number
474 * @end_bitidx: The last bit of interest to retrieve
475 * @mask: mask of bits that the caller is interested in
477 * Return: pageblock_bits flags
479 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
481 unsigned long end_bitidx,
484 unsigned long *bitmap;
485 unsigned long bitidx, word_bitidx;
488 bitmap = get_pageblock_bitmap(page, pfn);
489 bitidx = pfn_to_bitidx(page, pfn);
490 word_bitidx = bitidx / BITS_PER_LONG;
491 bitidx &= (BITS_PER_LONG-1);
493 word = bitmap[word_bitidx];
494 bitidx += end_bitidx;
495 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
498 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
499 unsigned long end_bitidx,
502 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
505 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
507 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
511 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
512 * @page: The page within the block of interest
513 * @flags: The flags to set
514 * @pfn: The target page frame number
515 * @end_bitidx: The last bit of interest
516 * @mask: mask of bits that the caller is interested in
518 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
520 unsigned long end_bitidx,
523 unsigned long *bitmap;
524 unsigned long bitidx, word_bitidx;
525 unsigned long old_word, word;
527 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
528 BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
530 bitmap = get_pageblock_bitmap(page, pfn);
531 bitidx = pfn_to_bitidx(page, pfn);
532 word_bitidx = bitidx / BITS_PER_LONG;
533 bitidx &= (BITS_PER_LONG-1);
535 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
537 bitidx += end_bitidx;
538 mask <<= (BITS_PER_LONG - bitidx - 1);
539 flags <<= (BITS_PER_LONG - bitidx - 1);
541 word = READ_ONCE(bitmap[word_bitidx]);
543 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
544 if (word == old_word)
550 void set_pageblock_migratetype(struct page *page, int migratetype)
552 if (unlikely(page_group_by_mobility_disabled &&
553 migratetype < MIGRATE_PCPTYPES))
554 migratetype = MIGRATE_UNMOVABLE;
556 set_pageblock_flags_group(page, (unsigned long)migratetype,
557 PB_migrate, PB_migrate_end);
560 #ifdef CONFIG_DEBUG_VM
561 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
565 unsigned long pfn = page_to_pfn(page);
566 unsigned long sp, start_pfn;
569 seq = zone_span_seqbegin(zone);
570 start_pfn = zone->zone_start_pfn;
571 sp = zone->spanned_pages;
572 if (!zone_spans_pfn(zone, pfn))
574 } while (zone_span_seqretry(zone, seq));
577 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
578 pfn, zone_to_nid(zone), zone->name,
579 start_pfn, start_pfn + sp);
584 static int page_is_consistent(struct zone *zone, struct page *page)
586 if (!pfn_valid_within(page_to_pfn(page)))
588 if (zone != page_zone(page))
594 * Temporary debugging check for pages not lying within a given zone.
596 static int __maybe_unused bad_range(struct zone *zone, struct page *page)
598 if (page_outside_zone_boundaries(zone, page))
600 if (!page_is_consistent(zone, page))
606 static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
612 static void bad_page(struct page *page, const char *reason,
613 unsigned long bad_flags)
615 static unsigned long resume;
616 static unsigned long nr_shown;
617 static unsigned long nr_unshown;
620 * Allow a burst of 60 reports, then keep quiet for that minute;
621 * or allow a steady drip of one report per second.
623 if (nr_shown == 60) {
624 if (time_before(jiffies, resume)) {
630 "BUG: Bad page state: %lu messages suppressed\n",
637 resume = jiffies + 60 * HZ;
639 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
640 current->comm, page_to_pfn(page));
641 __dump_page(page, reason);
642 bad_flags &= page->flags;
644 pr_alert("bad because of flags: %#lx(%pGp)\n",
645 bad_flags, &bad_flags);
646 dump_page_owner(page);
651 /* Leave bad fields for debug, except PageBuddy could make trouble */
652 page_mapcount_reset(page); /* remove PageBuddy */
653 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
657 * Higher-order pages are called "compound pages". They are structured thusly:
659 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
661 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
662 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
664 * The first tail page's ->compound_dtor holds the offset in array of compound
665 * page destructors. See compound_page_dtors.
667 * The first tail page's ->compound_order holds the order of allocation.
668 * This usage means that zero-order pages may not be compound.
671 void free_compound_page(struct page *page)
673 mem_cgroup_uncharge(page);
674 __free_pages_ok(page, compound_order(page));
677 void prep_compound_page(struct page *page, unsigned int order)
680 int nr_pages = 1 << order;
682 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
683 set_compound_order(page, order);
685 for (i = 1; i < nr_pages; i++) {
686 struct page *p = page + i;
687 set_page_count(p, 0);
688 p->mapping = TAIL_MAPPING;
689 set_compound_head(p, page);
691 atomic_set(compound_mapcount_ptr(page), -1);
692 if (hpage_pincount_available(page))
693 atomic_set(compound_pincount_ptr(page), 0);
696 #ifdef CONFIG_DEBUG_PAGEALLOC
697 unsigned int _debug_guardpage_minorder;
699 bool _debug_pagealloc_enabled_early __read_mostly
700 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
701 EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
702 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
703 EXPORT_SYMBOL(_debug_pagealloc_enabled);
705 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
707 static int __init early_debug_pagealloc(char *buf)
709 return kstrtobool(buf, &_debug_pagealloc_enabled_early);
711 early_param("debug_pagealloc", early_debug_pagealloc);
713 void init_debug_pagealloc(void)
715 if (!debug_pagealloc_enabled())
718 static_branch_enable(&_debug_pagealloc_enabled);
720 if (!debug_guardpage_minorder())
723 static_branch_enable(&_debug_guardpage_enabled);
726 static int __init debug_guardpage_minorder_setup(char *buf)
730 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
731 pr_err("Bad debug_guardpage_minorder value\n");
734 _debug_guardpage_minorder = res;
735 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
738 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
740 static inline bool set_page_guard(struct zone *zone, struct page *page,
741 unsigned int order, int migratetype)
743 if (!debug_guardpage_enabled())
746 if (order >= debug_guardpage_minorder())
749 __SetPageGuard(page);
750 INIT_LIST_HEAD(&page->lru);
751 set_page_private(page, order);
752 /* Guard pages are not available for any usage */
753 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
758 static inline void clear_page_guard(struct zone *zone, struct page *page,
759 unsigned int order, int migratetype)
761 if (!debug_guardpage_enabled())
764 __ClearPageGuard(page);
766 set_page_private(page, 0);
767 if (!is_migrate_isolate(migratetype))
768 __mod_zone_freepage_state(zone, (1 << order), migratetype);
771 static inline bool set_page_guard(struct zone *zone, struct page *page,
772 unsigned int order, int migratetype) { return false; }
773 static inline void clear_page_guard(struct zone *zone, struct page *page,
774 unsigned int order, int migratetype) {}
777 static inline void set_page_order(struct page *page, unsigned int order)
779 set_page_private(page, order);
780 __SetPageBuddy(page);
784 * This function checks whether a page is free && is the buddy
785 * we can coalesce a page and its buddy if
786 * (a) the buddy is not in a hole (check before calling!) &&
787 * (b) the buddy is in the buddy system &&
788 * (c) a page and its buddy have the same order &&
789 * (d) a page and its buddy are in the same zone.
791 * For recording whether a page is in the buddy system, we set PageBuddy.
792 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
794 * For recording page's order, we use page_private(page).
796 static inline bool page_is_buddy(struct page *page, struct page *buddy,
799 if (!page_is_guard(buddy) && !PageBuddy(buddy))
802 if (page_order(buddy) != order)
806 * zone check is done late to avoid uselessly calculating
807 * zone/node ids for pages that could never merge.
809 if (page_zone_id(page) != page_zone_id(buddy))
812 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
817 #ifdef CONFIG_COMPACTION
818 static inline struct capture_control *task_capc(struct zone *zone)
820 struct capture_control *capc = current->capture_control;
823 !(current->flags & PF_KTHREAD) &&
825 capc->cc->zone == zone &&
826 capc->cc->direct_compaction ? capc : NULL;
830 compaction_capture(struct capture_control *capc, struct page *page,
831 int order, int migratetype)
833 if (!capc || order != capc->cc->order)
836 /* Do not accidentally pollute CMA or isolated regions*/
837 if (is_migrate_cma(migratetype) ||
838 is_migrate_isolate(migratetype))
842 * Do not let lower order allocations polluate a movable pageblock.
843 * This might let an unmovable request use a reclaimable pageblock
844 * and vice-versa but no more than normal fallback logic which can
845 * have trouble finding a high-order free page.
847 if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
855 static inline struct capture_control *task_capc(struct zone *zone)
861 compaction_capture(struct capture_control *capc, struct page *page,
862 int order, int migratetype)
866 #endif /* CONFIG_COMPACTION */
868 /* Used for pages not on another list */
869 static inline void add_to_free_list(struct page *page, struct zone *zone,
870 unsigned int order, int migratetype)
872 struct free_area *area = &zone->free_area[order];
874 list_add(&page->lru, &area->free_list[migratetype]);
878 /* Used for pages not on another list */
879 static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
880 unsigned int order, int migratetype)
882 struct free_area *area = &zone->free_area[order];
884 list_add_tail(&page->lru, &area->free_list[migratetype]);
888 /* Used for pages which are on another list */
889 static inline void move_to_free_list(struct page *page, struct zone *zone,
890 unsigned int order, int migratetype)
892 struct free_area *area = &zone->free_area[order];
894 list_move(&page->lru, &area->free_list[migratetype]);
897 static inline void del_page_from_free_list(struct page *page, struct zone *zone,
900 /* clear reported state and update reported page count */
901 if (page_reported(page))
902 __ClearPageReported(page);
904 list_del(&page->lru);
905 __ClearPageBuddy(page);
906 set_page_private(page, 0);
907 zone->free_area[order].nr_free--;
911 * If this is not the largest possible page, check if the buddy
912 * of the next-highest order is free. If it is, it's possible
913 * that pages are being freed that will coalesce soon. In case,
914 * that is happening, add the free page to the tail of the list
915 * so it's less likely to be used soon and more likely to be merged
916 * as a higher order page
919 buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
920 struct page *page, unsigned int order)
922 struct page *higher_page, *higher_buddy;
923 unsigned long combined_pfn;
925 if (order >= MAX_ORDER - 2)
928 if (!pfn_valid_within(buddy_pfn))
931 combined_pfn = buddy_pfn & pfn;
932 higher_page = page + (combined_pfn - pfn);
933 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
934 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
936 return pfn_valid_within(buddy_pfn) &&
937 page_is_buddy(higher_page, higher_buddy, order + 1);
941 * Freeing function for a buddy system allocator.
943 * The concept of a buddy system is to maintain direct-mapped table
944 * (containing bit values) for memory blocks of various "orders".
945 * The bottom level table contains the map for the smallest allocatable
946 * units of memory (here, pages), and each level above it describes
947 * pairs of units from the levels below, hence, "buddies".
948 * At a high level, all that happens here is marking the table entry
949 * at the bottom level available, and propagating the changes upward
950 * as necessary, plus some accounting needed to play nicely with other
951 * parts of the VM system.
952 * At each level, we keep a list of pages, which are heads of continuous
953 * free pages of length of (1 << order) and marked with PageBuddy.
954 * Page's order is recorded in page_private(page) field.
955 * So when we are allocating or freeing one, we can derive the state of the
956 * other. That is, if we allocate a small block, and both were
957 * free, the remainder of the region must be split into blocks.
958 * If a block is freed, and its buddy is also free, then this
959 * triggers coalescing into a block of larger size.
964 static inline void __free_one_page(struct page *page,
966 struct zone *zone, unsigned int order,
967 int migratetype, bool report)
969 struct capture_control *capc = task_capc(zone);
970 unsigned long uninitialized_var(buddy_pfn);
971 unsigned long combined_pfn;
972 unsigned int max_order;
976 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
978 VM_BUG_ON(!zone_is_initialized(zone));
979 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
981 VM_BUG_ON(migratetype == -1);
982 if (likely(!is_migrate_isolate(migratetype)))
983 __mod_zone_freepage_state(zone, 1 << order, migratetype);
985 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
986 VM_BUG_ON_PAGE(bad_range(zone, page), page);
989 while (order < max_order - 1) {
990 if (compaction_capture(capc, page, order, migratetype)) {
991 __mod_zone_freepage_state(zone, -(1 << order),
995 buddy_pfn = __find_buddy_pfn(pfn, order);
996 buddy = page + (buddy_pfn - pfn);
998 if (!pfn_valid_within(buddy_pfn))
1000 if (!page_is_buddy(page, buddy, order))
1003 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
1004 * merge with it and move up one order.
1006 if (page_is_guard(buddy))
1007 clear_page_guard(zone, buddy, order, migratetype);
1009 del_page_from_free_list(buddy, zone, order);
1010 combined_pfn = buddy_pfn & pfn;
1011 page = page + (combined_pfn - pfn);
1015 if (max_order < MAX_ORDER) {
1016 /* If we are here, it means order is >= pageblock_order.
1017 * We want to prevent merge between freepages on isolate
1018 * pageblock and normal pageblock. Without this, pageblock
1019 * isolation could cause incorrect freepage or CMA accounting.
1021 * We don't want to hit this code for the more frequent
1022 * low-order merging.
1024 if (unlikely(has_isolate_pageblock(zone))) {
1027 buddy_pfn = __find_buddy_pfn(pfn, order);
1028 buddy = page + (buddy_pfn - pfn);
1029 buddy_mt = get_pageblock_migratetype(buddy);
1031 if (migratetype != buddy_mt
1032 && (is_migrate_isolate(migratetype) ||
1033 is_migrate_isolate(buddy_mt)))
1037 goto continue_merging;
1041 set_page_order(page, order);
1043 if (is_shuffle_order(order))
1044 to_tail = shuffle_pick_tail();
1046 to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
1049 add_to_free_list_tail(page, zone, order, migratetype);
1051 add_to_free_list(page, zone, order, migratetype);
1053 /* Notify page reporting subsystem of freed page */
1055 page_reporting_notify_free(order);
1059 * A bad page could be due to a number of fields. Instead of multiple branches,
1060 * try and check multiple fields with one check. The caller must do a detailed
1061 * check if necessary.
1063 static inline bool page_expected_state(struct page *page,
1064 unsigned long check_flags)
1066 if (unlikely(atomic_read(&page->_mapcount) != -1))
1069 if (unlikely((unsigned long)page->mapping |
1070 page_ref_count(page) |
1072 (unsigned long)page->mem_cgroup |
1074 (page->flags & check_flags)))
1080 static void free_pages_check_bad(struct page *page)
1082 const char *bad_reason;
1083 unsigned long bad_flags;
1088 if (unlikely(atomic_read(&page->_mapcount) != -1))
1089 bad_reason = "nonzero mapcount";
1090 if (unlikely(page->mapping != NULL))
1091 bad_reason = "non-NULL mapping";
1092 if (unlikely(page_ref_count(page) != 0))
1093 bad_reason = "nonzero _refcount";
1094 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
1095 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1096 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
1099 if (unlikely(page->mem_cgroup))
1100 bad_reason = "page still charged to cgroup";
1102 bad_page(page, bad_reason, bad_flags);
1105 static inline int free_pages_check(struct page *page)
1107 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
1110 /* Something has gone sideways, find it */
1111 free_pages_check_bad(page);
1115 static int free_tail_pages_check(struct page *head_page, struct page *page)
1120 * We rely page->lru.next never has bit 0 set, unless the page
1121 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1123 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
1125 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
1129 switch (page - head_page) {
1131 /* the first tail page: ->mapping may be compound_mapcount() */
1132 if (unlikely(compound_mapcount(page))) {
1133 bad_page(page, "nonzero compound_mapcount", 0);
1139 * the second tail page: ->mapping is
1140 * deferred_list.next -- ignore value.
1144 if (page->mapping != TAIL_MAPPING) {
1145 bad_page(page, "corrupted mapping in tail page", 0);
1150 if (unlikely(!PageTail(page))) {
1151 bad_page(page, "PageTail not set", 0);
1154 if (unlikely(compound_head(page) != head_page)) {
1155 bad_page(page, "compound_head not consistent", 0);
1160 page->mapping = NULL;
1161 clear_compound_head(page);
1165 static void kernel_init_free_pages(struct page *page, int numpages)
1169 for (i = 0; i < numpages; i++)
1170 clear_highpage(page + i);
1173 static __always_inline bool free_pages_prepare(struct page *page,
1174 unsigned int order, bool check_free)
1178 VM_BUG_ON_PAGE(PageTail(page), page);
1180 trace_mm_page_free(page, order);
1183 * Check tail pages before head page information is cleared to
1184 * avoid checking PageCompound for order-0 pages.
1186 if (unlikely(order)) {
1187 bool compound = PageCompound(page);
1190 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1193 ClearPageDoubleMap(page);
1194 for (i = 1; i < (1 << order); i++) {
1196 bad += free_tail_pages_check(page, page + i);
1197 if (unlikely(free_pages_check(page + i))) {
1201 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1204 if (PageMappingFlags(page))
1205 page->mapping = NULL;
1206 if (memcg_kmem_enabled() && PageKmemcg(page))
1207 __memcg_kmem_uncharge_page(page, order);
1209 bad += free_pages_check(page);
1213 page_cpupid_reset_last(page);
1214 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1215 reset_page_owner(page, order);
1217 if (!PageHighMem(page)) {
1218 debug_check_no_locks_freed(page_address(page),
1219 PAGE_SIZE << order);
1220 debug_check_no_obj_freed(page_address(page),
1221 PAGE_SIZE << order);
1223 if (want_init_on_free())
1224 kernel_init_free_pages(page, 1 << order);
1226 kernel_poison_pages(page, 1 << order, 0);
1228 * arch_free_page() can make the page's contents inaccessible. s390
1229 * does this. So nothing which can access the page's contents should
1230 * happen after this.
1232 arch_free_page(page, order);
1234 if (debug_pagealloc_enabled_static())
1235 kernel_map_pages(page, 1 << order, 0);
1237 kasan_free_nondeferred_pages(page, order);
1242 #ifdef CONFIG_DEBUG_VM
1244 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1245 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1246 * moved from pcp lists to free lists.
1248 static bool free_pcp_prepare(struct page *page)
1250 return free_pages_prepare(page, 0, true);
1253 static bool bulkfree_pcp_prepare(struct page *page)
1255 if (debug_pagealloc_enabled_static())
1256 return free_pages_check(page);
1262 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1263 * moving from pcp lists to free list in order to reduce overhead. With
1264 * debug_pagealloc enabled, they are checked also immediately when being freed
1267 static bool free_pcp_prepare(struct page *page)
1269 if (debug_pagealloc_enabled_static())
1270 return free_pages_prepare(page, 0, true);
1272 return free_pages_prepare(page, 0, false);
1275 static bool bulkfree_pcp_prepare(struct page *page)
1277 return free_pages_check(page);
1279 #endif /* CONFIG_DEBUG_VM */
1281 static inline void prefetch_buddy(struct page *page)
1283 unsigned long pfn = page_to_pfn(page);
1284 unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0);
1285 struct page *buddy = page + (buddy_pfn - pfn);
1291 * Frees a number of pages from the PCP lists
1292 * Assumes all pages on list are in same zone, and of same order.
1293 * count is the number of pages to free.
1295 * If the zone was previously in an "all pages pinned" state then look to
1296 * see if this freeing clears that state.
1298 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1299 * pinned" detection logic.
1301 static void free_pcppages_bulk(struct zone *zone, int count,
1302 struct per_cpu_pages *pcp)
1304 int migratetype = 0;
1306 int prefetch_nr = 0;
1307 bool isolated_pageblocks;
1308 struct page *page, *tmp;
1312 struct list_head *list;
1315 * Remove pages from lists in a round-robin fashion. A
1316 * batch_free count is maintained that is incremented when an
1317 * empty list is encountered. This is so more pages are freed
1318 * off fuller lists instead of spinning excessively around empty
1323 if (++migratetype == MIGRATE_PCPTYPES)
1325 list = &pcp->lists[migratetype];
1326 } while (list_empty(list));
1328 /* This is the only non-empty list. Free them all. */
1329 if (batch_free == MIGRATE_PCPTYPES)
1333 page = list_last_entry(list, struct page, lru);
1334 /* must delete to avoid corrupting pcp list */
1335 list_del(&page->lru);
1338 if (bulkfree_pcp_prepare(page))
1341 list_add_tail(&page->lru, &head);
1344 * We are going to put the page back to the global
1345 * pool, prefetch its buddy to speed up later access
1346 * under zone->lock. It is believed the overhead of
1347 * an additional test and calculating buddy_pfn here
1348 * can be offset by reduced memory latency later. To
1349 * avoid excessive prefetching due to large count, only
1350 * prefetch buddy for the first pcp->batch nr of pages.
1352 if (prefetch_nr++ < pcp->batch)
1353 prefetch_buddy(page);
1354 } while (--count && --batch_free && !list_empty(list));
1357 spin_lock(&zone->lock);
1358 isolated_pageblocks = has_isolate_pageblock(zone);
1361 * Use safe version since after __free_one_page(),
1362 * page->lru.next will not point to original list.
1364 list_for_each_entry_safe(page, tmp, &head, lru) {
1365 int mt = get_pcppage_migratetype(page);
1366 /* MIGRATE_ISOLATE page should not go to pcplists */
1367 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1368 /* Pageblock could have been isolated meanwhile */
1369 if (unlikely(isolated_pageblocks))
1370 mt = get_pageblock_migratetype(page);
1372 __free_one_page(page, page_to_pfn(page), zone, 0, mt, true);
1373 trace_mm_page_pcpu_drain(page, 0, mt);
1375 spin_unlock(&zone->lock);
1378 static void free_one_page(struct zone *zone,
1379 struct page *page, unsigned long pfn,
1383 spin_lock(&zone->lock);
1384 if (unlikely(has_isolate_pageblock(zone) ||
1385 is_migrate_isolate(migratetype))) {
1386 migratetype = get_pfnblock_migratetype(page, pfn);
1388 __free_one_page(page, pfn, zone, order, migratetype, true);
1389 spin_unlock(&zone->lock);
1392 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1393 unsigned long zone, int nid)
1395 mm_zero_struct_page(page);
1396 set_page_links(page, zone, nid, pfn);
1397 init_page_count(page);
1398 page_mapcount_reset(page);
1399 page_cpupid_reset_last(page);
1400 page_kasan_tag_reset(page);
1402 INIT_LIST_HEAD(&page->lru);
1403 #ifdef WANT_PAGE_VIRTUAL
1404 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1405 if (!is_highmem_idx(zone))
1406 set_page_address(page, __va(pfn << PAGE_SHIFT));
1410 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1411 static void __meminit init_reserved_page(unsigned long pfn)
1416 if (!early_page_uninitialised(pfn))
1419 nid = early_pfn_to_nid(pfn);
1420 pgdat = NODE_DATA(nid);
1422 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1423 struct zone *zone = &pgdat->node_zones[zid];
1425 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1428 __init_single_page(pfn_to_page(pfn), pfn, zid, nid);
1431 static inline void init_reserved_page(unsigned long pfn)
1434 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1437 * Initialised pages do not have PageReserved set. This function is
1438 * called for each range allocated by the bootmem allocator and
1439 * marks the pages PageReserved. The remaining valid pages are later
1440 * sent to the buddy page allocator.
1442 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1444 unsigned long start_pfn = PFN_DOWN(start);
1445 unsigned long end_pfn = PFN_UP(end);
1447 for (; start_pfn < end_pfn; start_pfn++) {
1448 if (pfn_valid(start_pfn)) {
1449 struct page *page = pfn_to_page(start_pfn);
1451 init_reserved_page(start_pfn);
1453 /* Avoid false-positive PageTail() */
1454 INIT_LIST_HEAD(&page->lru);
1457 * no need for atomic set_bit because the struct
1458 * page is not visible yet so nobody should
1461 __SetPageReserved(page);
1466 static void __free_pages_ok(struct page *page, unsigned int order)
1468 unsigned long flags;
1470 unsigned long pfn = page_to_pfn(page);
1472 if (!free_pages_prepare(page, order, true))
1475 migratetype = get_pfnblock_migratetype(page, pfn);
1476 local_irq_save(flags);
1477 __count_vm_events(PGFREE, 1 << order);
1478 free_one_page(page_zone(page), page, pfn, order, migratetype);
1479 local_irq_restore(flags);
1482 void __free_pages_core(struct page *page, unsigned int order)
1484 unsigned int nr_pages = 1 << order;
1485 struct page *p = page;
1489 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1491 __ClearPageReserved(p);
1492 set_page_count(p, 0);
1494 __ClearPageReserved(p);
1495 set_page_count(p, 0);
1497 atomic_long_add(nr_pages, &page_zone(page)->managed_pages);
1498 set_page_refcounted(page);
1499 __free_pages(page, order);
1502 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1503 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1505 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1507 int __meminit early_pfn_to_nid(unsigned long pfn)
1509 static DEFINE_SPINLOCK(early_pfn_lock);
1512 spin_lock(&early_pfn_lock);
1513 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1515 nid = first_online_node;
1516 spin_unlock(&early_pfn_lock);
1522 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1523 /* Only safe to use early in boot when initialisation is single-threaded */
1524 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1528 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1529 if (nid >= 0 && nid != node)
1535 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1542 void __init memblock_free_pages(struct page *page, unsigned long pfn,
1545 if (early_page_uninitialised(pfn))
1547 __free_pages_core(page, order);
1551 * Check that the whole (or subset of) a pageblock given by the interval of
1552 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1553 * with the migration of free compaction scanner. The scanners then need to
1554 * use only pfn_valid_within() check for arches that allow holes within
1557 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1559 * It's possible on some configurations to have a setup like node0 node1 node0
1560 * i.e. it's possible that all pages within a zones range of pages do not
1561 * belong to a single zone. We assume that a border between node0 and node1
1562 * can occur within a single pageblock, but not a node0 node1 node0
1563 * interleaving within a single pageblock. It is therefore sufficient to check
1564 * the first and last page of a pageblock and avoid checking each individual
1565 * page in a pageblock.
1567 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1568 unsigned long end_pfn, struct zone *zone)
1570 struct page *start_page;
1571 struct page *end_page;
1573 /* end_pfn is one past the range we are checking */
1576 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1579 start_page = pfn_to_online_page(start_pfn);
1583 if (page_zone(start_page) != zone)
1586 end_page = pfn_to_page(end_pfn);
1588 /* This gives a shorter code than deriving page_zone(end_page) */
1589 if (page_zone_id(start_page) != page_zone_id(end_page))
1595 void set_zone_contiguous(struct zone *zone)
1597 unsigned long block_start_pfn = zone->zone_start_pfn;
1598 unsigned long block_end_pfn;
1600 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1601 for (; block_start_pfn < zone_end_pfn(zone);
1602 block_start_pfn = block_end_pfn,
1603 block_end_pfn += pageblock_nr_pages) {
1605 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1607 if (!__pageblock_pfn_to_page(block_start_pfn,
1608 block_end_pfn, zone))
1612 /* We confirm that there is no hole */
1613 zone->contiguous = true;
1616 void clear_zone_contiguous(struct zone *zone)
1618 zone->contiguous = false;
1621 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1622 static void __init deferred_free_range(unsigned long pfn,
1623 unsigned long nr_pages)
1631 page = pfn_to_page(pfn);
1633 /* Free a large naturally-aligned chunk if possible */
1634 if (nr_pages == pageblock_nr_pages &&
1635 (pfn & (pageblock_nr_pages - 1)) == 0) {
1636 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1637 __free_pages_core(page, pageblock_order);
1641 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1642 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1643 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1644 __free_pages_core(page, 0);
1648 /* Completion tracking for deferred_init_memmap() threads */
1649 static atomic_t pgdat_init_n_undone __initdata;
1650 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1652 static inline void __init pgdat_init_report_one_done(void)
1654 if (atomic_dec_and_test(&pgdat_init_n_undone))
1655 complete(&pgdat_init_all_done_comp);
1659 * Returns true if page needs to be initialized or freed to buddy allocator.
1661 * First we check if pfn is valid on architectures where it is possible to have
1662 * holes within pageblock_nr_pages. On systems where it is not possible, this
1663 * function is optimized out.
1665 * Then, we check if a current large page is valid by only checking the validity
1668 static inline bool __init deferred_pfn_valid(unsigned long pfn)
1670 if (!pfn_valid_within(pfn))
1672 if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
1678 * Free pages to buddy allocator. Try to free aligned pages in
1679 * pageblock_nr_pages sizes.
1681 static void __init deferred_free_pages(unsigned long pfn,
1682 unsigned long end_pfn)
1684 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1685 unsigned long nr_free = 0;
1687 for (; pfn < end_pfn; pfn++) {
1688 if (!deferred_pfn_valid(pfn)) {
1689 deferred_free_range(pfn - nr_free, nr_free);
1691 } else if (!(pfn & nr_pgmask)) {
1692 deferred_free_range(pfn - nr_free, nr_free);
1694 touch_nmi_watchdog();
1699 /* Free the last block of pages to allocator */
1700 deferred_free_range(pfn - nr_free, nr_free);
1704 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1705 * by performing it only once every pageblock_nr_pages.
1706 * Return number of pages initialized.
1708 static unsigned long __init deferred_init_pages(struct zone *zone,
1710 unsigned long end_pfn)
1712 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1713 int nid = zone_to_nid(zone);
1714 unsigned long nr_pages = 0;
1715 int zid = zone_idx(zone);
1716 struct page *page = NULL;
1718 for (; pfn < end_pfn; pfn++) {
1719 if (!deferred_pfn_valid(pfn)) {
1722 } else if (!page || !(pfn & nr_pgmask)) {
1723 page = pfn_to_page(pfn);
1724 touch_nmi_watchdog();
1728 __init_single_page(page, pfn, zid, nid);
1735 * This function is meant to pre-load the iterator for the zone init.
1736 * Specifically it walks through the ranges until we are caught up to the
1737 * first_init_pfn value and exits there. If we never encounter the value we
1738 * return false indicating there are no valid ranges left.
1741 deferred_init_mem_pfn_range_in_zone(u64 *i, struct zone *zone,
1742 unsigned long *spfn, unsigned long *epfn,
1743 unsigned long first_init_pfn)
1748 * Start out by walking through the ranges in this zone that have
1749 * already been initialized. We don't need to do anything with them
1750 * so we just need to flush them out of the system.
1752 for_each_free_mem_pfn_range_in_zone(j, zone, spfn, epfn) {
1753 if (*epfn <= first_init_pfn)
1755 if (*spfn < first_init_pfn)
1756 *spfn = first_init_pfn;
1765 * Initialize and free pages. We do it in two loops: first we initialize
1766 * struct page, then free to buddy allocator, because while we are
1767 * freeing pages we can access pages that are ahead (computing buddy
1768 * page in __free_one_page()).
1770 * In order to try and keep some memory in the cache we have the loop
1771 * broken along max page order boundaries. This way we will not cause
1772 * any issues with the buddy page computation.
1774 static unsigned long __init
1775 deferred_init_maxorder(u64 *i, struct zone *zone, unsigned long *start_pfn,
1776 unsigned long *end_pfn)
1778 unsigned long mo_pfn = ALIGN(*start_pfn + 1, MAX_ORDER_NR_PAGES);
1779 unsigned long spfn = *start_pfn, epfn = *end_pfn;
1780 unsigned long nr_pages = 0;
1783 /* First we loop through and initialize the page values */
1784 for_each_free_mem_pfn_range_in_zone_from(j, zone, start_pfn, end_pfn) {
1787 if (mo_pfn <= *start_pfn)
1790 t = min(mo_pfn, *end_pfn);
1791 nr_pages += deferred_init_pages(zone, *start_pfn, t);
1793 if (mo_pfn < *end_pfn) {
1794 *start_pfn = mo_pfn;
1799 /* Reset values and now loop through freeing pages as needed */
1802 for_each_free_mem_pfn_range_in_zone_from(j, zone, &spfn, &epfn) {
1808 t = min(mo_pfn, epfn);
1809 deferred_free_pages(spfn, t);
1818 /* Initialise remaining memory on a node */
1819 static int __init deferred_init_memmap(void *data)
1821 pg_data_t *pgdat = data;
1822 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1823 unsigned long spfn = 0, epfn = 0, nr_pages = 0;
1824 unsigned long first_init_pfn, flags;
1825 unsigned long start = jiffies;
1830 /* Bind memory initialisation thread to a local node if possible */
1831 if (!cpumask_empty(cpumask))
1832 set_cpus_allowed_ptr(current, cpumask);
1834 pgdat_resize_lock(pgdat, &flags);
1835 first_init_pfn = pgdat->first_deferred_pfn;
1836 if (first_init_pfn == ULONG_MAX) {
1837 pgdat_resize_unlock(pgdat, &flags);
1838 pgdat_init_report_one_done();
1842 /* Sanity check boundaries */
1843 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1844 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1845 pgdat->first_deferred_pfn = ULONG_MAX;
1847 /* Only the highest zone is deferred so find it */
1848 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1849 zone = pgdat->node_zones + zid;
1850 if (first_init_pfn < zone_end_pfn(zone))
1854 /* If the zone is empty somebody else may have cleared out the zone */
1855 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1860 * Initialize and free pages in MAX_ORDER sized increments so
1861 * that we can avoid introducing any issues with the buddy
1865 nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn);
1867 pgdat_resize_unlock(pgdat, &flags);
1869 /* Sanity check that the next zone really is unpopulated */
1870 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1872 pr_info("node %d initialised, %lu pages in %ums\n",
1873 pgdat->node_id, nr_pages, jiffies_to_msecs(jiffies - start));
1875 pgdat_init_report_one_done();
1880 * If this zone has deferred pages, try to grow it by initializing enough
1881 * deferred pages to satisfy the allocation specified by order, rounded up to
1882 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1883 * of SECTION_SIZE bytes by initializing struct pages in increments of
1884 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1886 * Return true when zone was grown, otherwise return false. We return true even
1887 * when we grow less than requested, to let the caller decide if there are
1888 * enough pages to satisfy the allocation.
1890 * Note: We use noinline because this function is needed only during boot, and
1891 * it is called from a __ref function _deferred_grow_zone. This way we are
1892 * making sure that it is not inlined into permanent text section.
1894 static noinline bool __init
1895 deferred_grow_zone(struct zone *zone, unsigned int order)
1897 unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
1898 pg_data_t *pgdat = zone->zone_pgdat;
1899 unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
1900 unsigned long spfn, epfn, flags;
1901 unsigned long nr_pages = 0;
1904 /* Only the last zone may have deferred pages */
1905 if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))
1908 pgdat_resize_lock(pgdat, &flags);
1911 * If deferred pages have been initialized while we were waiting for
1912 * the lock, return true, as the zone was grown. The caller will retry
1913 * this zone. We won't return to this function since the caller also
1914 * has this static branch.
1916 if (!static_branch_unlikely(&deferred_pages)) {
1917 pgdat_resize_unlock(pgdat, &flags);
1922 * If someone grew this zone while we were waiting for spinlock, return
1923 * true, as there might be enough pages already.
1925 if (first_deferred_pfn != pgdat->first_deferred_pfn) {
1926 pgdat_resize_unlock(pgdat, &flags);
1930 /* If the zone is empty somebody else may have cleared out the zone */
1931 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1932 first_deferred_pfn)) {
1933 pgdat->first_deferred_pfn = ULONG_MAX;
1934 pgdat_resize_unlock(pgdat, &flags);
1935 /* Retry only once. */
1936 return first_deferred_pfn != ULONG_MAX;
1940 * Initialize and free pages in MAX_ORDER sized increments so
1941 * that we can avoid introducing any issues with the buddy
1944 while (spfn < epfn) {
1945 /* update our first deferred PFN for this section */
1946 first_deferred_pfn = spfn;
1948 nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn);
1950 /* We should only stop along section boundaries */
1951 if ((first_deferred_pfn ^ spfn) < PAGES_PER_SECTION)
1954 /* If our quota has been met we can stop here */
1955 if (nr_pages >= nr_pages_needed)
1959 pgdat->first_deferred_pfn = spfn;
1960 pgdat_resize_unlock(pgdat, &flags);
1962 return nr_pages > 0;
1966 * deferred_grow_zone() is __init, but it is called from
1967 * get_page_from_freelist() during early boot until deferred_pages permanently
1968 * disables this call. This is why we have refdata wrapper to avoid warning,
1969 * and to ensure that the function body gets unloaded.
1972 _deferred_grow_zone(struct zone *zone, unsigned int order)
1974 return deferred_grow_zone(zone, order);
1977 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1979 void __init page_alloc_init_late(void)
1984 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1986 /* There will be num_node_state(N_MEMORY) threads */
1987 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1988 for_each_node_state(nid, N_MEMORY) {
1989 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1992 /* Block until all are initialised */
1993 wait_for_completion(&pgdat_init_all_done_comp);
1996 * The number of managed pages has changed due to the initialisation
1997 * so the pcpu batch and high limits needs to be updated or the limits
1998 * will be artificially small.
2000 for_each_populated_zone(zone)
2001 zone_pcp_update(zone);
2004 * We initialized the rest of the deferred pages. Permanently disable
2005 * on-demand struct page initialization.
2007 static_branch_disable(&deferred_pages);
2009 /* Reinit limits that are based on free pages after the kernel is up */
2010 files_maxfiles_init();
2013 /* Discard memblock private memory */
2016 for_each_node_state(nid, N_MEMORY)
2017 shuffle_free_memory(NODE_DATA(nid));
2019 for_each_populated_zone(zone)
2020 set_zone_contiguous(zone);
2024 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2025 void __init init_cma_reserved_pageblock(struct page *page)
2027 unsigned i = pageblock_nr_pages;
2028 struct page *p = page;
2031 __ClearPageReserved(p);
2032 set_page_count(p, 0);
2035 set_pageblock_migratetype(page, MIGRATE_CMA);
2037 if (pageblock_order >= MAX_ORDER) {
2038 i = pageblock_nr_pages;
2041 set_page_refcounted(p);
2042 __free_pages(p, MAX_ORDER - 1);
2043 p += MAX_ORDER_NR_PAGES;
2044 } while (i -= MAX_ORDER_NR_PAGES);
2046 set_page_refcounted(page);
2047 __free_pages(page, pageblock_order);
2050 adjust_managed_page_count(page, pageblock_nr_pages);
2055 * The order of subdivision here is critical for the IO subsystem.
2056 * Please do not alter this order without good reasons and regression
2057 * testing. Specifically, as large blocks of memory are subdivided,
2058 * the order in which smaller blocks are delivered depends on the order
2059 * they're subdivided in this function. This is the primary factor
2060 * influencing the order in which pages are delivered to the IO
2061 * subsystem according to empirical testing, and this is also justified
2062 * by considering the behavior of a buddy system containing a single
2063 * large block of memory acted on by a series of small allocations.
2064 * This behavior is a critical factor in sglist merging's success.
2068 static inline void expand(struct zone *zone, struct page *page,
2069 int low, int high, int migratetype)
2071 unsigned long size = 1 << high;
2073 while (high > low) {
2076 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
2079 * Mark as guard pages (or page), that will allow to
2080 * merge back to allocator when buddy will be freed.
2081 * Corresponding page table entries will not be touched,
2082 * pages will stay not present in virtual address space
2084 if (set_page_guard(zone, &page[size], high, migratetype))
2087 add_to_free_list(&page[size], zone, high, migratetype);
2088 set_page_order(&page[size], high);
2092 static void check_new_page_bad(struct page *page)
2094 const char *bad_reason = NULL;
2095 unsigned long bad_flags = 0;
2097 if (unlikely(atomic_read(&page->_mapcount) != -1))
2098 bad_reason = "nonzero mapcount";
2099 if (unlikely(page->mapping != NULL))
2100 bad_reason = "non-NULL mapping";
2101 if (unlikely(page_ref_count(page) != 0))
2102 bad_reason = "nonzero _refcount";
2103 if (unlikely(page->flags & __PG_HWPOISON)) {
2104 bad_reason = "HWPoisoned (hardware-corrupted)";
2105 bad_flags = __PG_HWPOISON;
2106 /* Don't complain about hwpoisoned pages */
2107 page_mapcount_reset(page); /* remove PageBuddy */
2110 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
2111 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
2112 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
2115 if (unlikely(page->mem_cgroup))
2116 bad_reason = "page still charged to cgroup";
2118 bad_page(page, bad_reason, bad_flags);
2122 * This page is about to be returned from the page allocator
2124 static inline int check_new_page(struct page *page)
2126 if (likely(page_expected_state(page,
2127 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
2130 check_new_page_bad(page);
2134 static inline bool free_pages_prezeroed(void)
2136 return (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
2137 page_poisoning_enabled()) || want_init_on_free();
2140 #ifdef CONFIG_DEBUG_VM
2142 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2143 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2144 * also checked when pcp lists are refilled from the free lists.
2146 static inline bool check_pcp_refill(struct page *page)
2148 if (debug_pagealloc_enabled_static())
2149 return check_new_page(page);
2154 static inline bool check_new_pcp(struct page *page)
2156 return check_new_page(page);
2160 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2161 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2162 * enabled, they are also checked when being allocated from the pcp lists.
2164 static inline bool check_pcp_refill(struct page *page)
2166 return check_new_page(page);
2168 static inline bool check_new_pcp(struct page *page)
2170 if (debug_pagealloc_enabled_static())
2171 return check_new_page(page);
2175 #endif /* CONFIG_DEBUG_VM */
2177 static bool check_new_pages(struct page *page, unsigned int order)
2180 for (i = 0; i < (1 << order); i++) {
2181 struct page *p = page + i;
2183 if (unlikely(check_new_page(p)))
2190 inline void post_alloc_hook(struct page *page, unsigned int order,
2193 set_page_private(page, 0);
2194 set_page_refcounted(page);
2196 arch_alloc_page(page, order);
2197 if (debug_pagealloc_enabled_static())
2198 kernel_map_pages(page, 1 << order, 1);
2199 kasan_alloc_pages(page, order);
2200 kernel_poison_pages(page, 1 << order, 1);
2201 set_page_owner(page, order, gfp_flags);
2204 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
2205 unsigned int alloc_flags)
2207 post_alloc_hook(page, order, gfp_flags);
2209 if (!free_pages_prezeroed() && want_init_on_alloc(gfp_flags))
2210 kernel_init_free_pages(page, 1 << order);
2212 if (order && (gfp_flags & __GFP_COMP))
2213 prep_compound_page(page, order);
2216 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2217 * allocate the page. The expectation is that the caller is taking
2218 * steps that will free more memory. The caller should avoid the page
2219 * being used for !PFMEMALLOC purposes.
2221 if (alloc_flags & ALLOC_NO_WATERMARKS)
2222 set_page_pfmemalloc(page);
2224 clear_page_pfmemalloc(page);
2228 * Go through the free lists for the given migratetype and remove
2229 * the smallest available page from the freelists
2231 static __always_inline
2232 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
2235 unsigned int current_order;
2236 struct free_area *area;
2239 /* Find a page of the appropriate size in the preferred list */
2240 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
2241 area = &(zone->free_area[current_order]);
2242 page = get_page_from_free_area(area, migratetype);
2245 del_page_from_free_list(page, zone, current_order);
2246 expand(zone, page, order, current_order, migratetype);
2247 set_pcppage_migratetype(page, migratetype);
2256 * This array describes the order lists are fallen back to when
2257 * the free lists for the desirable migrate type are depleted
2259 static int fallbacks[MIGRATE_TYPES][4] = {
2260 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2261 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
2262 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2264 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
2266 #ifdef CONFIG_MEMORY_ISOLATION
2267 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
2272 static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2275 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
2278 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2279 unsigned int order) { return NULL; }
2283 * Move the free pages in a range to the free lists of the requested type.
2284 * Note that start_page and end_pages are not aligned on a pageblock
2285 * boundary. If alignment is required, use move_freepages_block()
2287 static int move_freepages(struct zone *zone,
2288 struct page *start_page, struct page *end_page,
2289 int migratetype, int *num_movable)
2293 int pages_moved = 0;
2295 for (page = start_page; page <= end_page;) {
2296 if (!pfn_valid_within(page_to_pfn(page))) {
2301 if (!PageBuddy(page)) {
2303 * We assume that pages that could be isolated for
2304 * migration are movable. But we don't actually try
2305 * isolating, as that would be expensive.
2308 (PageLRU(page) || __PageMovable(page)))
2315 /* Make sure we are not inadvertently changing nodes */
2316 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
2317 VM_BUG_ON_PAGE(page_zone(page) != zone, page);
2319 order = page_order(page);
2320 move_to_free_list(page, zone, order, migratetype);
2322 pages_moved += 1 << order;
2328 int move_freepages_block(struct zone *zone, struct page *page,
2329 int migratetype, int *num_movable)
2331 unsigned long start_pfn, end_pfn;
2332 struct page *start_page, *end_page;
2337 start_pfn = page_to_pfn(page);
2338 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
2339 start_page = pfn_to_page(start_pfn);
2340 end_page = start_page + pageblock_nr_pages - 1;
2341 end_pfn = start_pfn + pageblock_nr_pages - 1;
2343 /* Do not cross zone boundaries */
2344 if (!zone_spans_pfn(zone, start_pfn))
2346 if (!zone_spans_pfn(zone, end_pfn))
2349 return move_freepages(zone, start_page, end_page, migratetype,
2353 static void change_pageblock_range(struct page *pageblock_page,
2354 int start_order, int migratetype)
2356 int nr_pageblocks = 1 << (start_order - pageblock_order);
2358 while (nr_pageblocks--) {
2359 set_pageblock_migratetype(pageblock_page, migratetype);
2360 pageblock_page += pageblock_nr_pages;
2365 * When we are falling back to another migratetype during allocation, try to
2366 * steal extra free pages from the same pageblocks to satisfy further
2367 * allocations, instead of polluting multiple pageblocks.
2369 * If we are stealing a relatively large buddy page, it is likely there will
2370 * be more free pages in the pageblock, so try to steal them all. For
2371 * reclaimable and unmovable allocations, we steal regardless of page size,
2372 * as fragmentation caused by those allocations polluting movable pageblocks
2373 * is worse than movable allocations stealing from unmovable and reclaimable
2376 static bool can_steal_fallback(unsigned int order, int start_mt)
2379 * Leaving this order check is intended, although there is
2380 * relaxed order check in next check. The reason is that
2381 * we can actually steal whole pageblock if this condition met,
2382 * but, below check doesn't guarantee it and that is just heuristic
2383 * so could be changed anytime.
2385 if (order >= pageblock_order)
2388 if (order >= pageblock_order / 2 ||
2389 start_mt == MIGRATE_RECLAIMABLE ||
2390 start_mt == MIGRATE_UNMOVABLE ||
2391 page_group_by_mobility_disabled)
2397 static inline void boost_watermark(struct zone *zone)
2399 unsigned long max_boost;
2401 if (!watermark_boost_factor)
2404 max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
2405 watermark_boost_factor, 10000);
2408 * high watermark may be uninitialised if fragmentation occurs
2409 * very early in boot so do not boost. We do not fall
2410 * through and boost by pageblock_nr_pages as failing
2411 * allocations that early means that reclaim is not going
2412 * to help and it may even be impossible to reclaim the
2413 * boosted watermark resulting in a hang.
2418 max_boost = max(pageblock_nr_pages, max_boost);
2420 zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages,
2425 * This function implements actual steal behaviour. If order is large enough,
2426 * we can steal whole pageblock. If not, we first move freepages in this
2427 * pageblock to our migratetype and determine how many already-allocated pages
2428 * are there in the pageblock with a compatible migratetype. If at least half
2429 * of pages are free or compatible, we can change migratetype of the pageblock
2430 * itself, so pages freed in the future will be put on the correct free list.
2432 static void steal_suitable_fallback(struct zone *zone, struct page *page,
2433 unsigned int alloc_flags, int start_type, bool whole_block)
2435 unsigned int current_order = page_order(page);
2436 int free_pages, movable_pages, alike_pages;
2439 old_block_type = get_pageblock_migratetype(page);
2442 * This can happen due to races and we want to prevent broken
2443 * highatomic accounting.
2445 if (is_migrate_highatomic(old_block_type))
2448 /* Take ownership for orders >= pageblock_order */
2449 if (current_order >= pageblock_order) {
2450 change_pageblock_range(page, current_order, start_type);
2455 * Boost watermarks to increase reclaim pressure to reduce the
2456 * likelihood of future fallbacks. Wake kswapd now as the node
2457 * may be balanced overall and kswapd will not wake naturally.
2459 boost_watermark(zone);
2460 if (alloc_flags & ALLOC_KSWAPD)
2461 set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
2463 /* We are not allowed to try stealing from the whole block */
2467 free_pages = move_freepages_block(zone, page, start_type,
2470 * Determine how many pages are compatible with our allocation.
2471 * For movable allocation, it's the number of movable pages which
2472 * we just obtained. For other types it's a bit more tricky.
2474 if (start_type == MIGRATE_MOVABLE) {
2475 alike_pages = movable_pages;
2478 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2479 * to MOVABLE pageblock, consider all non-movable pages as
2480 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2481 * vice versa, be conservative since we can't distinguish the
2482 * exact migratetype of non-movable pages.
2484 if (old_block_type == MIGRATE_MOVABLE)
2485 alike_pages = pageblock_nr_pages
2486 - (free_pages + movable_pages);
2491 /* moving whole block can fail due to zone boundary conditions */
2496 * If a sufficient number of pages in the block are either free or of
2497 * comparable migratability as our allocation, claim the whole block.
2499 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2500 page_group_by_mobility_disabled)
2501 set_pageblock_migratetype(page, start_type);
2506 move_to_free_list(page, zone, current_order, start_type);
2510 * Check whether there is a suitable fallback freepage with requested order.
2511 * If only_stealable is true, this function returns fallback_mt only if
2512 * we can steal other freepages all together. This would help to reduce
2513 * fragmentation due to mixed migratetype pages in one pageblock.
2515 int find_suitable_fallback(struct free_area *area, unsigned int order,
2516 int migratetype, bool only_stealable, bool *can_steal)
2521 if (area->nr_free == 0)
2526 fallback_mt = fallbacks[migratetype][i];
2527 if (fallback_mt == MIGRATE_TYPES)
2530 if (free_area_empty(area, fallback_mt))
2533 if (can_steal_fallback(order, migratetype))
2536 if (!only_stealable)
2547 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2548 * there are no empty page blocks that contain a page with a suitable order
2550 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2551 unsigned int alloc_order)
2554 unsigned long max_managed, flags;
2557 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2558 * Check is race-prone but harmless.
2560 max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;
2561 if (zone->nr_reserved_highatomic >= max_managed)
2564 spin_lock_irqsave(&zone->lock, flags);
2566 /* Recheck the nr_reserved_highatomic limit under the lock */
2567 if (zone->nr_reserved_highatomic >= max_managed)
2571 mt = get_pageblock_migratetype(page);
2572 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2573 && !is_migrate_cma(mt)) {
2574 zone->nr_reserved_highatomic += pageblock_nr_pages;
2575 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2576 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2580 spin_unlock_irqrestore(&zone->lock, flags);
2584 * Used when an allocation is about to fail under memory pressure. This
2585 * potentially hurts the reliability of high-order allocations when under
2586 * intense memory pressure but failed atomic allocations should be easier
2587 * to recover from than an OOM.
2589 * If @force is true, try to unreserve a pageblock even though highatomic
2590 * pageblock is exhausted.
2592 static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2595 struct zonelist *zonelist = ac->zonelist;
2596 unsigned long flags;
2603 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2606 * Preserve at least one pageblock unless memory pressure
2609 if (!force && zone->nr_reserved_highatomic <=
2613 spin_lock_irqsave(&zone->lock, flags);
2614 for (order = 0; order < MAX_ORDER; order++) {
2615 struct free_area *area = &(zone->free_area[order]);
2617 page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
2622 * In page freeing path, migratetype change is racy so
2623 * we can counter several free pages in a pageblock
2624 * in this loop althoug we changed the pageblock type
2625 * from highatomic to ac->migratetype. So we should
2626 * adjust the count once.
2628 if (is_migrate_highatomic_page(page)) {
2630 * It should never happen but changes to
2631 * locking could inadvertently allow a per-cpu
2632 * drain to add pages to MIGRATE_HIGHATOMIC
2633 * while unreserving so be safe and watch for
2636 zone->nr_reserved_highatomic -= min(
2638 zone->nr_reserved_highatomic);
2642 * Convert to ac->migratetype and avoid the normal
2643 * pageblock stealing heuristics. Minimally, the caller
2644 * is doing the work and needs the pages. More
2645 * importantly, if the block was always converted to
2646 * MIGRATE_UNMOVABLE or another type then the number
2647 * of pageblocks that cannot be completely freed
2650 set_pageblock_migratetype(page, ac->migratetype);
2651 ret = move_freepages_block(zone, page, ac->migratetype,
2654 spin_unlock_irqrestore(&zone->lock, flags);
2658 spin_unlock_irqrestore(&zone->lock, flags);
2665 * Try finding a free buddy page on the fallback list and put it on the free
2666 * list of requested migratetype, possibly along with other pages from the same
2667 * block, depending on fragmentation avoidance heuristics. Returns true if
2668 * fallback was found so that __rmqueue_smallest() can grab it.
2670 * The use of signed ints for order and current_order is a deliberate
2671 * deviation from the rest of this file, to make the for loop
2672 * condition simpler.
2674 static __always_inline bool
2675 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
2676 unsigned int alloc_flags)
2678 struct free_area *area;
2680 int min_order = order;
2686 * Do not steal pages from freelists belonging to other pageblocks
2687 * i.e. orders < pageblock_order. If there are no local zones free,
2688 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2690 if (alloc_flags & ALLOC_NOFRAGMENT)
2691 min_order = pageblock_order;
2694 * Find the largest available free page in the other list. This roughly
2695 * approximates finding the pageblock with the most free pages, which
2696 * would be too costly to do exactly.
2698 for (current_order = MAX_ORDER - 1; current_order >= min_order;
2700 area = &(zone->free_area[current_order]);
2701 fallback_mt = find_suitable_fallback(area, current_order,
2702 start_migratetype, false, &can_steal);
2703 if (fallback_mt == -1)
2707 * We cannot steal all free pages from the pageblock and the
2708 * requested migratetype is movable. In that case it's better to
2709 * steal and split the smallest available page instead of the
2710 * largest available page, because even if the next movable
2711 * allocation falls back into a different pageblock than this
2712 * one, it won't cause permanent fragmentation.
2714 if (!can_steal && start_migratetype == MIGRATE_MOVABLE
2715 && current_order > order)
2724 for (current_order = order; current_order < MAX_ORDER;
2726 area = &(zone->free_area[current_order]);
2727 fallback_mt = find_suitable_fallback(area, current_order,
2728 start_migratetype, false, &can_steal);
2729 if (fallback_mt != -1)
2734 * This should not happen - we already found a suitable fallback
2735 * when looking for the largest page.
2737 VM_BUG_ON(current_order == MAX_ORDER);
2740 page = get_page_from_free_area(area, fallback_mt);
2742 steal_suitable_fallback(zone, page, alloc_flags, start_migratetype,
2745 trace_mm_page_alloc_extfrag(page, order, current_order,
2746 start_migratetype, fallback_mt);
2753 * Do the hard work of removing an element from the buddy allocator.
2754 * Call me with the zone->lock already held.
2756 static __always_inline struct page *
2757 __rmqueue(struct zone *zone, unsigned int order, int migratetype,
2758 unsigned int alloc_flags)
2763 page = __rmqueue_smallest(zone, order, migratetype);
2764 if (unlikely(!page)) {
2765 if (migratetype == MIGRATE_MOVABLE)
2766 page = __rmqueue_cma_fallback(zone, order);
2768 if (!page && __rmqueue_fallback(zone, order, migratetype,
2773 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2778 * Obtain a specified number of elements from the buddy allocator, all under
2779 * a single hold of the lock, for efficiency. Add them to the supplied list.
2780 * Returns the number of new pages which were placed at *list.
2782 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2783 unsigned long count, struct list_head *list,
2784 int migratetype, unsigned int alloc_flags)
2788 spin_lock(&zone->lock);
2789 for (i = 0; i < count; ++i) {
2790 struct page *page = __rmqueue(zone, order, migratetype,
2792 if (unlikely(page == NULL))
2795 if (unlikely(check_pcp_refill(page)))
2799 * Split buddy pages returned by expand() are received here in
2800 * physical page order. The page is added to the tail of
2801 * caller's list. From the callers perspective, the linked list
2802 * is ordered by page number under some conditions. This is
2803 * useful for IO devices that can forward direction from the
2804 * head, thus also in the physical page order. This is useful
2805 * for IO devices that can merge IO requests if the physical
2806 * pages are ordered properly.
2808 list_add_tail(&page->lru, list);
2810 if (is_migrate_cma(get_pcppage_migratetype(page)))
2811 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2816 * i pages were removed from the buddy list even if some leak due
2817 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2818 * on i. Do not confuse with 'alloced' which is the number of
2819 * pages added to the pcp list.
2821 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2822 spin_unlock(&zone->lock);
2828 * Called from the vmstat counter updater to drain pagesets of this
2829 * currently executing processor on remote nodes after they have
2832 * Note that this function must be called with the thread pinned to
2833 * a single processor.
2835 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2837 unsigned long flags;
2838 int to_drain, batch;
2840 local_irq_save(flags);
2841 batch = READ_ONCE(pcp->batch);
2842 to_drain = min(pcp->count, batch);
2844 free_pcppages_bulk(zone, to_drain, pcp);
2845 local_irq_restore(flags);
2850 * Drain pcplists of the indicated processor and zone.
2852 * The processor must either be the current processor and the
2853 * thread pinned to the current processor or a processor that
2856 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2858 unsigned long flags;
2859 struct per_cpu_pageset *pset;
2860 struct per_cpu_pages *pcp;
2862 local_irq_save(flags);
2863 pset = per_cpu_ptr(zone->pageset, cpu);
2867 free_pcppages_bulk(zone, pcp->count, pcp);
2868 local_irq_restore(flags);
2872 * Drain pcplists of all zones on the indicated processor.
2874 * The processor must either be the current processor and the
2875 * thread pinned to the current processor or a processor that
2878 static void drain_pages(unsigned int cpu)
2882 for_each_populated_zone(zone) {
2883 drain_pages_zone(cpu, zone);
2888 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2890 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2891 * the single zone's pages.
2893 void drain_local_pages(struct zone *zone)
2895 int cpu = smp_processor_id();
2898 drain_pages_zone(cpu, zone);
2903 static void drain_local_pages_wq(struct work_struct *work)
2905 struct pcpu_drain *drain;
2907 drain = container_of(work, struct pcpu_drain, work);
2910 * drain_all_pages doesn't use proper cpu hotplug protection so
2911 * we can race with cpu offline when the WQ can move this from
2912 * a cpu pinned worker to an unbound one. We can operate on a different
2913 * cpu which is allright but we also have to make sure to not move to
2917 drain_local_pages(drain->zone);
2922 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2924 * When zone parameter is non-NULL, spill just the single zone's pages.
2926 * Note that this can be extremely slow as the draining happens in a workqueue.
2928 void drain_all_pages(struct zone *zone)
2933 * Allocate in the BSS so we wont require allocation in
2934 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2936 static cpumask_t cpus_with_pcps;
2939 * Make sure nobody triggers this path before mm_percpu_wq is fully
2942 if (WARN_ON_ONCE(!mm_percpu_wq))
2946 * Do not drain if one is already in progress unless it's specific to
2947 * a zone. Such callers are primarily CMA and memory hotplug and need
2948 * the drain to be complete when the call returns.
2950 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
2953 mutex_lock(&pcpu_drain_mutex);
2957 * We don't care about racing with CPU hotplug event
2958 * as offline notification will cause the notified
2959 * cpu to drain that CPU pcps and on_each_cpu_mask
2960 * disables preemption as part of its processing
2962 for_each_online_cpu(cpu) {
2963 struct per_cpu_pageset *pcp;
2965 bool has_pcps = false;
2968 pcp = per_cpu_ptr(zone->pageset, cpu);
2972 for_each_populated_zone(z) {
2973 pcp = per_cpu_ptr(z->pageset, cpu);
2974 if (pcp->pcp.count) {
2982 cpumask_set_cpu(cpu, &cpus_with_pcps);
2984 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2987 for_each_cpu(cpu, &cpus_with_pcps) {
2988 struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu);
2991 INIT_WORK(&drain->work, drain_local_pages_wq);
2992 queue_work_on(cpu, mm_percpu_wq, &drain->work);
2994 for_each_cpu(cpu, &cpus_with_pcps)
2995 flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work);
2997 mutex_unlock(&pcpu_drain_mutex);
3000 #ifdef CONFIG_HIBERNATION
3003 * Touch the watchdog for every WD_PAGE_COUNT pages.
3005 #define WD_PAGE_COUNT (128*1024)
3007 void mark_free_pages(struct zone *zone)
3009 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
3010 unsigned long flags;
3011 unsigned int order, t;
3014 if (zone_is_empty(zone))
3017 spin_lock_irqsave(&zone->lock, flags);
3019 max_zone_pfn = zone_end_pfn(zone);
3020 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
3021 if (pfn_valid(pfn)) {
3022 page = pfn_to_page(pfn);
3024 if (!--page_count) {
3025 touch_nmi_watchdog();
3026 page_count = WD_PAGE_COUNT;
3029 if (page_zone(page) != zone)
3032 if (!swsusp_page_is_forbidden(page))
3033 swsusp_unset_page_free(page);
3036 for_each_migratetype_order(order, t) {
3037 list_for_each_entry(page,
3038 &zone->free_area[order].free_list[t], lru) {
3041 pfn = page_to_pfn(page);
3042 for (i = 0; i < (1UL << order); i++) {
3043 if (!--page_count) {
3044 touch_nmi_watchdog();
3045 page_count = WD_PAGE_COUNT;
3047 swsusp_set_page_free(pfn_to_page(pfn + i));
3051 spin_unlock_irqrestore(&zone->lock, flags);
3053 #endif /* CONFIG_PM */
3055 static bool free_unref_page_prepare(struct page *page, unsigned long pfn)
3059 if (!free_pcp_prepare(page))
3062 migratetype = get_pfnblock_migratetype(page, pfn);
3063 set_pcppage_migratetype(page, migratetype);
3067 static void free_unref_page_commit(struct page *page, unsigned long pfn)
3069 struct zone *zone = page_zone(page);
3070 struct per_cpu_pages *pcp;
3073 migratetype = get_pcppage_migratetype(page);
3074 __count_vm_event(PGFREE);
3077 * We only track unmovable, reclaimable and movable on pcp lists.
3078 * Free ISOLATE pages back to the allocator because they are being
3079 * offlined but treat HIGHATOMIC as movable pages so we can get those
3080 * areas back if necessary. Otherwise, we may have to free
3081 * excessively into the page allocator
3083 if (migratetype >= MIGRATE_PCPTYPES) {
3084 if (unlikely(is_migrate_isolate(migratetype))) {
3085 free_one_page(zone, page, pfn, 0, migratetype);
3088 migratetype = MIGRATE_MOVABLE;
3091 pcp = &this_cpu_ptr(zone->pageset)->pcp;
3092 list_add(&page->lru, &pcp->lists[migratetype]);
3094 if (pcp->count >= pcp->high) {
3095 unsigned long batch = READ_ONCE(pcp->batch);
3096 free_pcppages_bulk(zone, batch, pcp);
3101 * Free a 0-order page
3103 void free_unref_page(struct page *page)
3105 unsigned long flags;
3106 unsigned long pfn = page_to_pfn(page);
3108 if (!free_unref_page_prepare(page, pfn))
3111 local_irq_save(flags);
3112 free_unref_page_commit(page, pfn);
3113 local_irq_restore(flags);
3117 * Free a list of 0-order pages
3119 void free_unref_page_list(struct list_head *list)
3121 struct page *page, *next;
3122 unsigned long flags, pfn;
3123 int batch_count = 0;
3125 /* Prepare pages for freeing */
3126 list_for_each_entry_safe(page, next, list, lru) {
3127 pfn = page_to_pfn(page);
3128 if (!free_unref_page_prepare(page, pfn))
3129 list_del(&page->lru);
3130 set_page_private(page, pfn);
3133 local_irq_save(flags);
3134 list_for_each_entry_safe(page, next, list, lru) {
3135 unsigned long pfn = page_private(page);
3137 set_page_private(page, 0);
3138 trace_mm_page_free_batched(page);
3139 free_unref_page_commit(page, pfn);
3142 * Guard against excessive IRQ disabled times when we get
3143 * a large list of pages to free.
3145 if (++batch_count == SWAP_CLUSTER_MAX) {
3146 local_irq_restore(flags);
3148 local_irq_save(flags);
3151 local_irq_restore(flags);
3155 * split_page takes a non-compound higher-order page, and splits it into
3156 * n (1<<order) sub-pages: page[0..n]
3157 * Each sub-page must be freed individually.
3159 * Note: this is probably too low level an operation for use in drivers.
3160 * Please consult with lkml before using this in your driver.
3162 void split_page(struct page *page, unsigned int order)
3166 VM_BUG_ON_PAGE(PageCompound(page), page);
3167 VM_BUG_ON_PAGE(!page_count(page), page);
3169 for (i = 1; i < (1 << order); i++)
3170 set_page_refcounted(page + i);
3171 split_page_owner(page, order);
3173 EXPORT_SYMBOL_GPL(split_page);
3175 int __isolate_free_page(struct page *page, unsigned int order)
3177 unsigned long watermark;
3181 BUG_ON(!PageBuddy(page));
3183 zone = page_zone(page);
3184 mt = get_pageblock_migratetype(page);
3186 if (!is_migrate_isolate(mt)) {
3188 * Obey watermarks as if the page was being allocated. We can
3189 * emulate a high-order watermark check with a raised order-0
3190 * watermark, because we already know our high-order page
3193 watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
3194 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
3197 __mod_zone_freepage_state(zone, -(1UL << order), mt);
3200 /* Remove page from free list */
3202 del_page_from_free_list(page, zone, order);
3205 * Set the pageblock if the isolated page is at least half of a
3208 if (order >= pageblock_order - 1) {
3209 struct page *endpage = page + (1 << order) - 1;
3210 for (; page < endpage; page += pageblock_nr_pages) {
3211 int mt = get_pageblock_migratetype(page);
3212 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
3213 && !is_migrate_highatomic(mt))
3214 set_pageblock_migratetype(page,
3220 return 1UL << order;
3224 * __putback_isolated_page - Return a now-isolated page back where we got it
3225 * @page: Page that was isolated
3226 * @order: Order of the isolated page
3228 * This function is meant to return a page pulled from the free lists via
3229 * __isolate_free_page back to the free lists they were pulled from.
3231 void __putback_isolated_page(struct page *page, unsigned int order, int mt)
3233 struct zone *zone = page_zone(page);
3235 /* zone lock should be held when this function is called */
3236 lockdep_assert_held(&zone->lock);
3238 /* Return isolated page to tail of freelist. */
3239 __free_one_page(page, page_to_pfn(page), zone, order, mt, false);
3243 * Update NUMA hit/miss statistics
3245 * Must be called with interrupts disabled.
3247 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
3250 enum numa_stat_item local_stat = NUMA_LOCAL;
3252 /* skip numa counters update if numa stats is disabled */
3253 if (!static_branch_likely(&vm_numa_stat_key))
3256 if (zone_to_nid(z) != numa_node_id())
3257 local_stat = NUMA_OTHER;
3259 if (zone_to_nid(z) == zone_to_nid(preferred_zone))
3260 __inc_numa_state(z, NUMA_HIT);
3262 __inc_numa_state(z, NUMA_MISS);
3263 __inc_numa_state(preferred_zone, NUMA_FOREIGN);
3265 __inc_numa_state(z, local_stat);
3269 /* Remove page from the per-cpu list, caller must protect the list */
3270 static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
3271 unsigned int alloc_flags,
3272 struct per_cpu_pages *pcp,
3273 struct list_head *list)
3278 if (list_empty(list)) {
3279 pcp->count += rmqueue_bulk(zone, 0,
3281 migratetype, alloc_flags);
3282 if (unlikely(list_empty(list)))
3286 page = list_first_entry(list, struct page, lru);
3287 list_del(&page->lru);
3289 } while (check_new_pcp(page));
3294 /* Lock and remove page from the per-cpu list */
3295 static struct page *rmqueue_pcplist(struct zone *preferred_zone,
3296 struct zone *zone, gfp_t gfp_flags,
3297 int migratetype, unsigned int alloc_flags)
3299 struct per_cpu_pages *pcp;
3300 struct list_head *list;
3302 unsigned long flags;
3304 local_irq_save(flags);
3305 pcp = &this_cpu_ptr(zone->pageset)->pcp;
3306 list = &pcp->lists[migratetype];
3307 page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list);
3309 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1);
3310 zone_statistics(preferred_zone, zone);
3312 local_irq_restore(flags);
3317 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3320 struct page *rmqueue(struct zone *preferred_zone,
3321 struct zone *zone, unsigned int order,
3322 gfp_t gfp_flags, unsigned int alloc_flags,
3325 unsigned long flags;
3328 if (likely(order == 0)) {
3329 page = rmqueue_pcplist(preferred_zone, zone, gfp_flags,
3330 migratetype, alloc_flags);
3335 * We most definitely don't want callers attempting to
3336 * allocate greater than order-1 page units with __GFP_NOFAIL.
3338 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
3339 spin_lock_irqsave(&zone->lock, flags);
3343 if (alloc_flags & ALLOC_HARDER) {
3344 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
3346 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3349 page = __rmqueue(zone, order, migratetype, alloc_flags);
3350 } while (page && check_new_pages(page, order));
3351 spin_unlock(&zone->lock);
3354 __mod_zone_freepage_state(zone, -(1 << order),
3355 get_pcppage_migratetype(page));
3357 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
3358 zone_statistics(preferred_zone, zone);
3359 local_irq_restore(flags);
3362 /* Separate test+clear to avoid unnecessary atomics */
3363 if (test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags)) {
3364 clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
3365 wakeup_kswapd(zone, 0, 0, zone_idx(zone));
3368 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
3372 local_irq_restore(flags);
3376 #ifdef CONFIG_FAIL_PAGE_ALLOC
3379 struct fault_attr attr;
3381 bool ignore_gfp_highmem;
3382 bool ignore_gfp_reclaim;
3384 } fail_page_alloc = {
3385 .attr = FAULT_ATTR_INITIALIZER,
3386 .ignore_gfp_reclaim = true,
3387 .ignore_gfp_highmem = true,
3391 static int __init setup_fail_page_alloc(char *str)
3393 return setup_fault_attr(&fail_page_alloc.attr, str);
3395 __setup("fail_page_alloc=", setup_fail_page_alloc);
3397 static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3399 if (order < fail_page_alloc.min_order)
3401 if (gfp_mask & __GFP_NOFAIL)
3403 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
3405 if (fail_page_alloc.ignore_gfp_reclaim &&
3406 (gfp_mask & __GFP_DIRECT_RECLAIM))
3409 return should_fail(&fail_page_alloc.attr, 1 << order);
3412 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3414 static int __init fail_page_alloc_debugfs(void)
3416 umode_t mode = S_IFREG | 0600;
3419 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
3420 &fail_page_alloc.attr);
3422 debugfs_create_bool("ignore-gfp-wait", mode, dir,
3423 &fail_page_alloc.ignore_gfp_reclaim);
3424 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
3425 &fail_page_alloc.ignore_gfp_highmem);
3426 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);
3431 late_initcall(fail_page_alloc_debugfs);
3433 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3435 #else /* CONFIG_FAIL_PAGE_ALLOC */
3437 static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3442 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3444 static noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3446 return __should_fail_alloc_page(gfp_mask, order);
3448 ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
3451 * Return true if free base pages are above 'mark'. For high-order checks it
3452 * will return true of the order-0 watermark is reached and there is at least
3453 * one free page of a suitable size. Checking now avoids taking the zone lock
3454 * to check in the allocation paths if no pages are free.
3456 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3457 int classzone_idx, unsigned int alloc_flags,
3462 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3464 /* free_pages may go negative - that's OK */
3465 free_pages -= (1 << order) - 1;
3467 if (alloc_flags & ALLOC_HIGH)
3471 * If the caller does not have rights to ALLOC_HARDER then subtract
3472 * the high-atomic reserves. This will over-estimate the size of the
3473 * atomic reserve but it avoids a search.
3475 if (likely(!alloc_harder)) {
3476 free_pages -= z->nr_reserved_highatomic;
3479 * OOM victims can try even harder than normal ALLOC_HARDER
3480 * users on the grounds that it's definitely going to be in
3481 * the exit path shortly and free memory. Any allocation it
3482 * makes during the free path will be small and short-lived.
3484 if (alloc_flags & ALLOC_OOM)
3492 /* If allocation can't use CMA areas don't use free CMA pages */
3493 if (!(alloc_flags & ALLOC_CMA))
3494 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
3498 * Check watermarks for an order-0 allocation request. If these
3499 * are not met, then a high-order request also cannot go ahead
3500 * even if a suitable page happened to be free.
3502 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
3505 /* If this is an order-0 request then the watermark is fine */
3509 /* For a high-order request, check at least one suitable page is free */
3510 for (o = order; o < MAX_ORDER; o++) {
3511 struct free_area *area = &z->free_area[o];
3517 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
3518 if (!free_area_empty(area, mt))
3523 if ((alloc_flags & ALLOC_CMA) &&
3524 !free_area_empty(area, MIGRATE_CMA)) {
3528 if (alloc_harder && !free_area_empty(area, MIGRATE_HIGHATOMIC))
3534 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3535 int classzone_idx, unsigned int alloc_flags)
3537 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
3538 zone_page_state(z, NR_FREE_PAGES));
3541 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
3542 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
3544 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3548 /* If allocation can't use CMA areas don't use free CMA pages */
3549 if (!(alloc_flags & ALLOC_CMA))
3550 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
3554 * Fast check for order-0 only. If this fails then the reserves
3555 * need to be calculated. There is a corner case where the check
3556 * passes but only the high-order atomic reserve are free. If
3557 * the caller is !atomic then it'll uselessly search the free
3558 * list. That corner case is then slower but it is harmless.
3560 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
3563 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
3567 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
3568 unsigned long mark, int classzone_idx)
3570 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3572 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
3573 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
3575 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
3580 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3582 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3583 node_reclaim_distance;
3585 #else /* CONFIG_NUMA */
3586 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3590 #endif /* CONFIG_NUMA */
3593 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3594 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3595 * premature use of a lower zone may cause lowmem pressure problems that
3596 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3597 * probably too small. It only makes sense to spread allocations to avoid
3598 * fragmentation between the Normal and DMA32 zones.
3600 static inline unsigned int
3601 alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
3603 unsigned int alloc_flags;
3606 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3609 alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM);
3611 #ifdef CONFIG_ZONE_DMA32
3615 if (zone_idx(zone) != ZONE_NORMAL)
3619 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3620 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3621 * on UMA that if Normal is populated then so is DMA32.
3623 BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1);
3624 if (nr_online_nodes > 1 && !populated_zone(--zone))
3627 alloc_flags |= ALLOC_NOFRAGMENT;
3628 #endif /* CONFIG_ZONE_DMA32 */
3633 * get_page_from_freelist goes through the zonelist trying to allocate
3636 static struct page *
3637 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
3638 const struct alloc_context *ac)
3642 struct pglist_data *last_pgdat_dirty_limit = NULL;
3647 * Scan zonelist, looking for a zone with enough free.
3648 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3650 no_fallback = alloc_flags & ALLOC_NOFRAGMENT;
3651 z = ac->preferred_zoneref;
3652 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3657 if (cpusets_enabled() &&
3658 (alloc_flags & ALLOC_CPUSET) &&
3659 !__cpuset_zone_allowed(zone, gfp_mask))
3662 * When allocating a page cache page for writing, we
3663 * want to get it from a node that is within its dirty
3664 * limit, such that no single node holds more than its
3665 * proportional share of globally allowed dirty pages.
3666 * The dirty limits take into account the node's
3667 * lowmem reserves and high watermark so that kswapd
3668 * should be able to balance it without having to
3669 * write pages from its LRU list.
3671 * XXX: For now, allow allocations to potentially
3672 * exceed the per-node dirty limit in the slowpath
3673 * (spread_dirty_pages unset) before going into reclaim,
3674 * which is important when on a NUMA setup the allowed
3675 * nodes are together not big enough to reach the
3676 * global limit. The proper fix for these situations
3677 * will require awareness of nodes in the
3678 * dirty-throttling and the flusher threads.
3680 if (ac->spread_dirty_pages) {
3681 if (last_pgdat_dirty_limit == zone->zone_pgdat)
3684 if (!node_dirty_ok(zone->zone_pgdat)) {
3685 last_pgdat_dirty_limit = zone->zone_pgdat;
3690 if (no_fallback && nr_online_nodes > 1 &&
3691 zone != ac->preferred_zoneref->zone) {
3695 * If moving to a remote node, retry but allow
3696 * fragmenting fallbacks. Locality is more important
3697 * than fragmentation avoidance.
3699 local_nid = zone_to_nid(ac->preferred_zoneref->zone);
3700 if (zone_to_nid(zone) != local_nid) {
3701 alloc_flags &= ~ALLOC_NOFRAGMENT;
3706 mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
3707 if (!zone_watermark_fast(zone, order, mark,
3708 ac_classzone_idx(ac), alloc_flags)) {
3711 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3713 * Watermark failed for this zone, but see if we can
3714 * grow this zone if it contains deferred pages.
3716 if (static_branch_unlikely(&deferred_pages)) {
3717 if (_deferred_grow_zone(zone, order))
3721 /* Checked here to keep the fast path fast */
3722 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
3723 if (alloc_flags & ALLOC_NO_WATERMARKS)
3726 if (node_reclaim_mode == 0 ||
3727 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
3730 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
3732 case NODE_RECLAIM_NOSCAN:
3735 case NODE_RECLAIM_FULL:
3736 /* scanned but unreclaimable */
3739 /* did we reclaim enough */
3740 if (zone_watermark_ok(zone, order, mark,
3741 ac_classzone_idx(ac), alloc_flags))
3749 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
3750 gfp_mask, alloc_flags, ac->migratetype);
3752 prep_new_page(page, order, gfp_mask, alloc_flags);
3755 * If this is a high-order atomic allocation then check
3756 * if the pageblock should be reserved for the future
3758 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3759 reserve_highatomic_pageblock(page, zone, order);
3763 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3764 /* Try again if zone has deferred pages */
3765 if (static_branch_unlikely(&deferred_pages)) {
3766 if (_deferred_grow_zone(zone, order))
3774 * It's possible on a UMA machine to get through all zones that are
3775 * fragmented. If avoiding fragmentation, reset and try again.
3778 alloc_flags &= ~ALLOC_NOFRAGMENT;
3785 static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
3787 unsigned int filter = SHOW_MEM_FILTER_NODES;
3790 * This documents exceptions given to allocations in certain
3791 * contexts that are allowed to allocate outside current's set
3794 if (!(gfp_mask & __GFP_NOMEMALLOC))
3795 if (tsk_is_oom_victim(current) ||
3796 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3797 filter &= ~SHOW_MEM_FILTER_NODES;
3798 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3799 filter &= ~SHOW_MEM_FILTER_NODES;
3801 show_mem(filter, nodemask);
3804 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
3806 struct va_format vaf;
3808 static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1);
3810 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
3813 va_start(args, fmt);
3816 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
3817 current->comm, &vaf, gfp_mask, &gfp_mask,
3818 nodemask_pr_args(nodemask));
3821 cpuset_print_current_mems_allowed();
3824 warn_alloc_show_mem(gfp_mask, nodemask);
3827 static inline struct page *
3828 __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
3829 unsigned int alloc_flags,
3830 const struct alloc_context *ac)
3834 page = get_page_from_freelist(gfp_mask, order,
3835 alloc_flags|ALLOC_CPUSET, ac);
3837 * fallback to ignore cpuset restriction if our nodes
3841 page = get_page_from_freelist(gfp_mask, order,
3847 static inline struct page *
3848 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3849 const struct alloc_context *ac, unsigned long *did_some_progress)
3851 struct oom_control oc = {
3852 .zonelist = ac->zonelist,
3853 .nodemask = ac->nodemask,
3855 .gfp_mask = gfp_mask,
3860 *did_some_progress = 0;
3863 * Acquire the oom lock. If that fails, somebody else is
3864 * making progress for us.
3866 if (!mutex_trylock(&oom_lock)) {
3867 *did_some_progress = 1;
3868 schedule_timeout_uninterruptible(1);
3873 * Go through the zonelist yet one more time, keep very high watermark
3874 * here, this is only to catch a parallel oom killing, we must fail if
3875 * we're still under heavy pressure. But make sure that this reclaim
3876 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3877 * allocation which will never fail due to oom_lock already held.
3879 page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
3880 ~__GFP_DIRECT_RECLAIM, order,
3881 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3885 /* Coredumps can quickly deplete all memory reserves */
3886 if (current->flags & PF_DUMPCORE)
3888 /* The OOM killer will not help higher order allocs */
3889 if (order > PAGE_ALLOC_COSTLY_ORDER)
3892 * We have already exhausted all our reclaim opportunities without any
3893 * success so it is time to admit defeat. We will skip the OOM killer
3894 * because it is very likely that the caller has a more reasonable
3895 * fallback than shooting a random task.
3897 if (gfp_mask & __GFP_RETRY_MAYFAIL)
3899 /* The OOM killer does not needlessly kill tasks for lowmem */
3900 if (ac->high_zoneidx < ZONE_NORMAL)
3902 if (pm_suspended_storage())
3905 * XXX: GFP_NOFS allocations should rather fail than rely on
3906 * other request to make a forward progress.
3907 * We are in an unfortunate situation where out_of_memory cannot
3908 * do much for this context but let's try it to at least get
3909 * access to memory reserved if the current task is killed (see
3910 * out_of_memory). Once filesystems are ready to handle allocation
3911 * failures more gracefully we should just bail out here.
3914 /* The OOM killer may not free memory on a specific node */
3915 if (gfp_mask & __GFP_THISNODE)
3918 /* Exhausted what can be done so it's blame time */
3919 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3920 *did_some_progress = 1;
3923 * Help non-failing allocations by giving them access to memory
3926 if (gfp_mask & __GFP_NOFAIL)
3927 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
3928 ALLOC_NO_WATERMARKS, ac);
3931 mutex_unlock(&oom_lock);
3936 * Maximum number of compaction retries wit a progress before OOM
3937 * killer is consider as the only way to move forward.
3939 #define MAX_COMPACT_RETRIES 16
3941 #ifdef CONFIG_COMPACTION
3942 /* Try memory compaction for high-order allocations before reclaim */
3943 static struct page *
3944 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3945 unsigned int alloc_flags, const struct alloc_context *ac,
3946 enum compact_priority prio, enum compact_result *compact_result)
3948 struct page *page = NULL;
3949 unsigned long pflags;
3950 unsigned int noreclaim_flag;
3955 psi_memstall_enter(&pflags);
3956 noreclaim_flag = memalloc_noreclaim_save();
3958 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3961 memalloc_noreclaim_restore(noreclaim_flag);
3962 psi_memstall_leave(&pflags);
3965 * At least in one zone compaction wasn't deferred or skipped, so let's
3966 * count a compaction stall
3968 count_vm_event(COMPACTSTALL);
3970 /* Prep a captured page if available */
3972 prep_new_page(page, order, gfp_mask, alloc_flags);
3974 /* Try get a page from the freelist if available */
3976 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3979 struct zone *zone = page_zone(page);
3981 zone->compact_blockskip_flush = false;
3982 compaction_defer_reset(zone, order, true);
3983 count_vm_event(COMPACTSUCCESS);
3988 * It's bad if compaction run occurs and fails. The most likely reason
3989 * is that pages exist, but not enough to satisfy watermarks.
3991 count_vm_event(COMPACTFAIL);
3999 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
4000 enum compact_result compact_result,
4001 enum compact_priority *compact_priority,
4002 int *compaction_retries)
4004 int max_retries = MAX_COMPACT_RETRIES;
4007 int retries = *compaction_retries;
4008 enum compact_priority priority = *compact_priority;
4013 if (compaction_made_progress(compact_result))
4014 (*compaction_retries)++;
4017 * compaction considers all the zone as desperately out of memory
4018 * so it doesn't really make much sense to retry except when the
4019 * failure could be caused by insufficient priority
4021 if (compaction_failed(compact_result))
4022 goto check_priority;
4025 * compaction was skipped because there are not enough order-0 pages
4026 * to work with, so we retry only if it looks like reclaim can help.
4028 if (compaction_needs_reclaim(compact_result)) {
4029 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
4034 * make sure the compaction wasn't deferred or didn't bail out early
4035 * due to locks contention before we declare that we should give up.
4036 * But the next retry should use a higher priority if allowed, so
4037 * we don't just keep bailing out endlessly.
4039 if (compaction_withdrawn(compact_result)) {
4040 goto check_priority;
4044 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4045 * costly ones because they are de facto nofail and invoke OOM
4046 * killer to move on while costly can fail and users are ready
4047 * to cope with that. 1/4 retries is rather arbitrary but we
4048 * would need much more detailed feedback from compaction to
4049 * make a better decision.
4051 if (order > PAGE_ALLOC_COSTLY_ORDER)
4053 if (*compaction_retries <= max_retries) {
4059 * Make sure there are attempts at the highest priority if we exhausted
4060 * all retries or failed at the lower priorities.
4063 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
4064 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
4066 if (*compact_priority > min_priority) {
4067 (*compact_priority)--;
4068 *compaction_retries = 0;
4072 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
4076 static inline struct page *
4077 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4078 unsigned int alloc_flags, const struct alloc_context *ac,
4079 enum compact_priority prio, enum compact_result *compact_result)
4081 *compact_result = COMPACT_SKIPPED;
4086 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
4087 enum compact_result compact_result,
4088 enum compact_priority *compact_priority,
4089 int *compaction_retries)
4094 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
4098 * There are setups with compaction disabled which would prefer to loop
4099 * inside the allocator rather than hit the oom killer prematurely.
4100 * Let's give them a good hope and keep retrying while the order-0
4101 * watermarks are OK.
4103 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
4105 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
4106 ac_classzone_idx(ac), alloc_flags))
4111 #endif /* CONFIG_COMPACTION */
4113 #ifdef CONFIG_LOCKDEP
4114 static struct lockdep_map __fs_reclaim_map =
4115 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
4117 static bool __need_fs_reclaim(gfp_t gfp_mask)
4119 gfp_mask = current_gfp_context(gfp_mask);
4121 /* no reclaim without waiting on it */
4122 if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
4125 /* this guy won't enter reclaim */
4126 if (current->flags & PF_MEMALLOC)
4129 /* We're only interested __GFP_FS allocations for now */
4130 if (!(gfp_mask & __GFP_FS))
4133 if (gfp_mask & __GFP_NOLOCKDEP)
4139 void __fs_reclaim_acquire(void)
4141 lock_map_acquire(&__fs_reclaim_map);
4144 void __fs_reclaim_release(void)
4146 lock_map_release(&__fs_reclaim_map);
4149 void fs_reclaim_acquire(gfp_t gfp_mask)
4151 if (__need_fs_reclaim(gfp_mask))
4152 __fs_reclaim_acquire();
4154 EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
4156 void fs_reclaim_release(gfp_t gfp_mask)
4158 if (__need_fs_reclaim(gfp_mask))
4159 __fs_reclaim_release();
4161 EXPORT_SYMBOL_GPL(fs_reclaim_release);
4164 /* Perform direct synchronous page reclaim */
4166 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
4167 const struct alloc_context *ac)
4170 unsigned int noreclaim_flag;
4171 unsigned long pflags;
4175 /* We now go into synchronous reclaim */
4176 cpuset_memory_pressure_bump();
4177 psi_memstall_enter(&pflags);
4178 fs_reclaim_acquire(gfp_mask);
4179 noreclaim_flag = memalloc_noreclaim_save();
4181 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
4184 memalloc_noreclaim_restore(noreclaim_flag);
4185 fs_reclaim_release(gfp_mask);
4186 psi_memstall_leave(&pflags);
4193 /* The really slow allocator path where we enter direct reclaim */
4194 static inline struct page *
4195 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
4196 unsigned int alloc_flags, const struct alloc_context *ac,
4197 unsigned long *did_some_progress)
4199 struct page *page = NULL;
4200 bool drained = false;
4202 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
4203 if (unlikely(!(*did_some_progress)))
4207 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4210 * If an allocation failed after direct reclaim, it could be because
4211 * pages are pinned on the per-cpu lists or in high alloc reserves.
4212 * Shrink them them and try again
4214 if (!page && !drained) {
4215 unreserve_highatomic_pageblock(ac, false);
4216 drain_all_pages(NULL);
4224 static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
4225 const struct alloc_context *ac)
4229 pg_data_t *last_pgdat = NULL;
4230 enum zone_type high_zoneidx = ac->high_zoneidx;
4232 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, high_zoneidx,
4234 if (last_pgdat != zone->zone_pgdat)
4235 wakeup_kswapd(zone, gfp_mask, order, high_zoneidx);
4236 last_pgdat = zone->zone_pgdat;
4240 static inline unsigned int
4241 gfp_to_alloc_flags(gfp_t gfp_mask)
4243 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
4246 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4247 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4248 * to save two branches.
4250 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
4251 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD);
4254 * The caller may dip into page reserves a bit more if the caller
4255 * cannot run direct reclaim, or if the caller has realtime scheduling
4256 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4257 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4259 alloc_flags |= (__force int)
4260 (gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM));
4262 if (gfp_mask & __GFP_ATOMIC) {
4264 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4265 * if it can't schedule.
4267 if (!(gfp_mask & __GFP_NOMEMALLOC))
4268 alloc_flags |= ALLOC_HARDER;
4270 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4271 * comment for __cpuset_node_allowed().
4273 alloc_flags &= ~ALLOC_CPUSET;
4274 } else if (unlikely(rt_task(current)) && !in_interrupt())
4275 alloc_flags |= ALLOC_HARDER;
4278 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
4279 alloc_flags |= ALLOC_CMA;
4284 static bool oom_reserves_allowed(struct task_struct *tsk)
4286 if (!tsk_is_oom_victim(tsk))
4290 * !MMU doesn't have oom reaper so give access to memory reserves
4291 * only to the thread with TIF_MEMDIE set
4293 if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
4300 * Distinguish requests which really need access to full memory
4301 * reserves from oom victims which can live with a portion of it
4303 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
4305 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
4307 if (gfp_mask & __GFP_MEMALLOC)
4308 return ALLOC_NO_WATERMARKS;
4309 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
4310 return ALLOC_NO_WATERMARKS;
4311 if (!in_interrupt()) {
4312 if (current->flags & PF_MEMALLOC)
4313 return ALLOC_NO_WATERMARKS;
4314 else if (oom_reserves_allowed(current))
4321 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
4323 return !!__gfp_pfmemalloc_flags(gfp_mask);
4327 * Checks whether it makes sense to retry the reclaim to make a forward progress
4328 * for the given allocation request.
4330 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4331 * without success, or when we couldn't even meet the watermark if we
4332 * reclaimed all remaining pages on the LRU lists.
4334 * Returns true if a retry is viable or false to enter the oom path.
4337 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
4338 struct alloc_context *ac, int alloc_flags,
4339 bool did_some_progress, int *no_progress_loops)
4346 * Costly allocations might have made a progress but this doesn't mean
4347 * their order will become available due to high fragmentation so
4348 * always increment the no progress counter for them
4350 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
4351 *no_progress_loops = 0;
4353 (*no_progress_loops)++;
4356 * Make sure we converge to OOM if we cannot make any progress
4357 * several times in the row.
4359 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
4360 /* Before OOM, exhaust highatomic_reserve */
4361 return unreserve_highatomic_pageblock(ac, true);
4365 * Keep reclaiming pages while there is a chance this will lead
4366 * somewhere. If none of the target zones can satisfy our allocation
4367 * request even if all reclaimable pages are considered then we are
4368 * screwed and have to go OOM.
4370 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
4372 unsigned long available;
4373 unsigned long reclaimable;
4374 unsigned long min_wmark = min_wmark_pages(zone);
4377 available = reclaimable = zone_reclaimable_pages(zone);
4378 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
4381 * Would the allocation succeed if we reclaimed all
4382 * reclaimable pages?
4384 wmark = __zone_watermark_ok(zone, order, min_wmark,
4385 ac_classzone_idx(ac), alloc_flags, available);
4386 trace_reclaim_retry_zone(z, order, reclaimable,
4387 available, min_wmark, *no_progress_loops, wmark);
4390 * If we didn't make any progress and have a lot of
4391 * dirty + writeback pages then we should wait for
4392 * an IO to complete to slow down the reclaim and
4393 * prevent from pre mature OOM
4395 if (!did_some_progress) {
4396 unsigned long write_pending;
4398 write_pending = zone_page_state_snapshot(zone,
4399 NR_ZONE_WRITE_PENDING);
4401 if (2 * write_pending > reclaimable) {
4402 congestion_wait(BLK_RW_ASYNC, HZ/10);
4414 * Memory allocation/reclaim might be called from a WQ context and the
4415 * current implementation of the WQ concurrency control doesn't
4416 * recognize that a particular WQ is congested if the worker thread is
4417 * looping without ever sleeping. Therefore we have to do a short sleep
4418 * here rather than calling cond_resched().
4420 if (current->flags & PF_WQ_WORKER)
4421 schedule_timeout_uninterruptible(1);
4428 check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
4431 * It's possible that cpuset's mems_allowed and the nodemask from
4432 * mempolicy don't intersect. This should be normally dealt with by
4433 * policy_nodemask(), but it's possible to race with cpuset update in
4434 * such a way the check therein was true, and then it became false
4435 * before we got our cpuset_mems_cookie here.
4436 * This assumes that for all allocations, ac->nodemask can come only
4437 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4438 * when it does not intersect with the cpuset restrictions) or the
4439 * caller can deal with a violated nodemask.
4441 if (cpusets_enabled() && ac->nodemask &&
4442 !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
4443 ac->nodemask = NULL;
4448 * When updating a task's mems_allowed or mempolicy nodemask, it is
4449 * possible to race with parallel threads in such a way that our
4450 * allocation can fail while the mask is being updated. If we are about
4451 * to fail, check if the cpuset changed during allocation and if so,
4454 if (read_mems_allowed_retry(cpuset_mems_cookie))
4460 static inline struct page *
4461 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
4462 struct alloc_context *ac)
4464 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
4465 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
4466 struct page *page = NULL;
4467 unsigned int alloc_flags;
4468 unsigned long did_some_progress;
4469 enum compact_priority compact_priority;
4470 enum compact_result compact_result;
4471 int compaction_retries;
4472 int no_progress_loops;
4473 unsigned int cpuset_mems_cookie;
4477 * We also sanity check to catch abuse of atomic reserves being used by
4478 * callers that are not in atomic context.
4480 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
4481 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
4482 gfp_mask &= ~__GFP_ATOMIC;
4485 compaction_retries = 0;
4486 no_progress_loops = 0;
4487 compact_priority = DEF_COMPACT_PRIORITY;
4488 cpuset_mems_cookie = read_mems_allowed_begin();
4491 * The fast path uses conservative alloc_flags to succeed only until
4492 * kswapd needs to be woken up, and to avoid the cost of setting up
4493 * alloc_flags precisely. So we do that now.
4495 alloc_flags = gfp_to_alloc_flags(gfp_mask);
4498 * We need to recalculate the starting point for the zonelist iterator
4499 * because we might have used different nodemask in the fast path, or
4500 * there was a cpuset modification and we are retrying - otherwise we
4501 * could end up iterating over non-eligible zones endlessly.
4503 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4504 ac->high_zoneidx, ac->nodemask);
4505 if (!ac->preferred_zoneref->zone)
4508 if (alloc_flags & ALLOC_KSWAPD)
4509 wake_all_kswapds(order, gfp_mask, ac);
4512 * The adjusted alloc_flags might result in immediate success, so try
4515 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4520 * For costly allocations, try direct compaction first, as it's likely
4521 * that we have enough base pages and don't need to reclaim. For non-
4522 * movable high-order allocations, do that as well, as compaction will
4523 * try prevent permanent fragmentation by migrating from blocks of the
4525 * Don't try this for allocations that are allowed to ignore
4526 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4528 if (can_direct_reclaim &&
4530 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
4531 && !gfp_pfmemalloc_allowed(gfp_mask)) {
4532 page = __alloc_pages_direct_compact(gfp_mask, order,
4534 INIT_COMPACT_PRIORITY,
4540 * Checks for costly allocations with __GFP_NORETRY, which
4541 * includes some THP page fault allocations
4543 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
4545 * If allocating entire pageblock(s) and compaction
4546 * failed because all zones are below low watermarks
4547 * or is prohibited because it recently failed at this
4548 * order, fail immediately unless the allocator has
4549 * requested compaction and reclaim retry.
4552 * - potentially very expensive because zones are far
4553 * below their low watermarks or this is part of very
4554 * bursty high order allocations,
4555 * - not guaranteed to help because isolate_freepages()
4556 * may not iterate over freed pages as part of its
4558 * - unlikely to make entire pageblocks free on its
4561 if (compact_result == COMPACT_SKIPPED ||
4562 compact_result == COMPACT_DEFERRED)
4566 * Looks like reclaim/compaction is worth trying, but
4567 * sync compaction could be very expensive, so keep
4568 * using async compaction.
4570 compact_priority = INIT_COMPACT_PRIORITY;
4575 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4576 if (alloc_flags & ALLOC_KSWAPD)
4577 wake_all_kswapds(order, gfp_mask, ac);
4579 reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
4581 alloc_flags = reserve_flags;
4584 * Reset the nodemask and zonelist iterators if memory policies can be
4585 * ignored. These allocations are high priority and system rather than
4588 if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
4589 ac->nodemask = NULL;
4590 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4591 ac->high_zoneidx, ac->nodemask);
4594 /* Attempt with potentially adjusted zonelist and alloc_flags */
4595 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4599 /* Caller is not willing to reclaim, we can't balance anything */
4600 if (!can_direct_reclaim)
4603 /* Avoid recursion of direct reclaim */
4604 if (current->flags & PF_MEMALLOC)
4607 /* Try direct reclaim and then allocating */
4608 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
4609 &did_some_progress);
4613 /* Try direct compaction and then allocating */
4614 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
4615 compact_priority, &compact_result);
4619 /* Do not loop if specifically requested */
4620 if (gfp_mask & __GFP_NORETRY)
4624 * Do not retry costly high order allocations unless they are
4625 * __GFP_RETRY_MAYFAIL
4627 if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
4630 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
4631 did_some_progress > 0, &no_progress_loops))
4635 * It doesn't make any sense to retry for the compaction if the order-0
4636 * reclaim is not able to make any progress because the current
4637 * implementation of the compaction depends on the sufficient amount
4638 * of free memory (see __compaction_suitable)
4640 if (did_some_progress > 0 &&
4641 should_compact_retry(ac, order, alloc_flags,
4642 compact_result, &compact_priority,
4643 &compaction_retries))
4647 /* Deal with possible cpuset update races before we start OOM killing */
4648 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4651 /* Reclaim has failed us, start killing things */
4652 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
4656 /* Avoid allocations with no watermarks from looping endlessly */
4657 if (tsk_is_oom_victim(current) &&
4658 (alloc_flags == ALLOC_OOM ||
4659 (gfp_mask & __GFP_NOMEMALLOC)))
4662 /* Retry as long as the OOM killer is making progress */
4663 if (did_some_progress) {
4664 no_progress_loops = 0;
4669 /* Deal with possible cpuset update races before we fail */
4670 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4674 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4677 if (gfp_mask & __GFP_NOFAIL) {
4679 * All existing users of the __GFP_NOFAIL are blockable, so warn
4680 * of any new users that actually require GFP_NOWAIT
4682 if (WARN_ON_ONCE(!can_direct_reclaim))
4686 * PF_MEMALLOC request from this context is rather bizarre
4687 * because we cannot reclaim anything and only can loop waiting
4688 * for somebody to do a work for us
4690 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
4693 * non failing costly orders are a hard requirement which we
4694 * are not prepared for much so let's warn about these users
4695 * so that we can identify them and convert them to something
4698 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
4701 * Help non-failing allocations by giving them access to memory
4702 * reserves but do not use ALLOC_NO_WATERMARKS because this
4703 * could deplete whole memory reserves which would just make
4704 * the situation worse
4706 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
4714 warn_alloc(gfp_mask, ac->nodemask,
4715 "page allocation failure: order:%u", order);
4720 static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
4721 int preferred_nid, nodemask_t *nodemask,
4722 struct alloc_context *ac, gfp_t *alloc_mask,
4723 unsigned int *alloc_flags)
4725 ac->high_zoneidx = gfp_zone(gfp_mask);
4726 ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
4727 ac->nodemask = nodemask;
4728 ac->migratetype = gfpflags_to_migratetype(gfp_mask);
4730 if (cpusets_enabled()) {
4731 *alloc_mask |= __GFP_HARDWALL;
4733 ac->nodemask = &cpuset_current_mems_allowed;
4735 *alloc_flags |= ALLOC_CPUSET;
4738 fs_reclaim_acquire(gfp_mask);
4739 fs_reclaim_release(gfp_mask);
4741 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
4743 if (should_fail_alloc_page(gfp_mask, order))
4746 if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE)
4747 *alloc_flags |= ALLOC_CMA;
4752 /* Determine whether to spread dirty pages and what the first usable zone */
4753 static inline void finalise_ac(gfp_t gfp_mask, struct alloc_context *ac)
4755 /* Dirty zone balancing only done in the fast path */
4756 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
4759 * The preferred zone is used for statistics but crucially it is
4760 * also used as the starting point for the zonelist iterator. It
4761 * may get reset for allocations that ignore memory policies.
4763 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4764 ac->high_zoneidx, ac->nodemask);
4768 * This is the 'heart' of the zoned buddy allocator.
4771 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
4772 nodemask_t *nodemask)
4775 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4776 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
4777 struct alloc_context ac = { };
4780 * There are several places where we assume that the order value is sane
4781 * so bail out early if the request is out of bound.
4783 if (unlikely(order >= MAX_ORDER)) {
4784 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4788 gfp_mask &= gfp_allowed_mask;
4789 alloc_mask = gfp_mask;
4790 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
4793 finalise_ac(gfp_mask, &ac);
4796 * Forbid the first pass from falling back to types that fragment
4797 * memory until all local zones are considered.
4799 alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp_mask);
4801 /* First allocation attempt */
4802 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
4807 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4808 * resp. GFP_NOIO which has to be inherited for all allocation requests
4809 * from a particular context which has been marked by
4810 * memalloc_no{fs,io}_{save,restore}.
4812 alloc_mask = current_gfp_context(gfp_mask);
4813 ac.spread_dirty_pages = false;
4816 * Restore the original nodemask if it was potentially replaced with
4817 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4819 ac.nodemask = nodemask;
4821 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
4824 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
4825 unlikely(__memcg_kmem_charge_page(page, gfp_mask, order) != 0)) {
4826 __free_pages(page, order);
4830 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
4834 EXPORT_SYMBOL(__alloc_pages_nodemask);
4837 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
4838 * address cannot represent highmem pages. Use alloc_pages and then kmap if
4839 * you need to access high mem.
4841 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
4845 page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order);
4848 return (unsigned long) page_address(page);
4850 EXPORT_SYMBOL(__get_free_pages);
4852 unsigned long get_zeroed_page(gfp_t gfp_mask)
4854 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
4856 EXPORT_SYMBOL(get_zeroed_page);
4858 static inline void free_the_page(struct page *page, unsigned int order)
4860 if (order == 0) /* Via pcp? */
4861 free_unref_page(page);
4863 __free_pages_ok(page, order);
4866 void __free_pages(struct page *page, unsigned int order)
4868 if (put_page_testzero(page))
4869 free_the_page(page, order);
4871 EXPORT_SYMBOL(__free_pages);
4873 void free_pages(unsigned long addr, unsigned int order)
4876 VM_BUG_ON(!virt_addr_valid((void *)addr));
4877 __free_pages(virt_to_page((void *)addr), order);
4881 EXPORT_SYMBOL(free_pages);
4885 * An arbitrary-length arbitrary-offset area of memory which resides
4886 * within a 0 or higher order page. Multiple fragments within that page
4887 * are individually refcounted, in the page's reference counter.
4889 * The page_frag functions below provide a simple allocation framework for
4890 * page fragments. This is used by the network stack and network device
4891 * drivers to provide a backing region of memory for use as either an
4892 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4894 static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
4897 struct page *page = NULL;
4898 gfp_t gfp = gfp_mask;
4900 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4901 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
4903 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
4904 PAGE_FRAG_CACHE_MAX_ORDER);
4905 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
4907 if (unlikely(!page))
4908 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
4910 nc->va = page ? page_address(page) : NULL;
4915 void __page_frag_cache_drain(struct page *page, unsigned int count)
4917 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
4919 if (page_ref_sub_and_test(page, count))
4920 free_the_page(page, compound_order(page));
4922 EXPORT_SYMBOL(__page_frag_cache_drain);
4924 void *page_frag_alloc(struct page_frag_cache *nc,
4925 unsigned int fragsz, gfp_t gfp_mask)
4927 unsigned int size = PAGE_SIZE;
4931 if (unlikely(!nc->va)) {
4933 page = __page_frag_cache_refill(nc, gfp_mask);
4937 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4938 /* if size can vary use size else just use PAGE_SIZE */
4941 /* Even if we own the page, we do not use atomic_set().
4942 * This would break get_page_unless_zero() users.
4944 page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE);
4946 /* reset page count bias and offset to start of new frag */
4947 nc->pfmemalloc = page_is_pfmemalloc(page);
4948 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
4952 offset = nc->offset - fragsz;
4953 if (unlikely(offset < 0)) {
4954 page = virt_to_page(nc->va);
4956 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
4959 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4960 /* if size can vary use size else just use PAGE_SIZE */
4963 /* OK, page count is 0, we can safely set it */
4964 set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1);
4966 /* reset page count bias and offset to start of new frag */
4967 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
4968 offset = size - fragsz;
4972 nc->offset = offset;
4974 return nc->va + offset;
4976 EXPORT_SYMBOL(page_frag_alloc);
4979 * Frees a page fragment allocated out of either a compound or order 0 page.
4981 void page_frag_free(void *addr)
4983 struct page *page = virt_to_head_page(addr);
4985 if (unlikely(put_page_testzero(page)))
4986 free_the_page(page, compound_order(page));
4988 EXPORT_SYMBOL(page_frag_free);
4990 static void *make_alloc_exact(unsigned long addr, unsigned int order,
4994 unsigned long alloc_end = addr + (PAGE_SIZE << order);
4995 unsigned long used = addr + PAGE_ALIGN(size);
4997 split_page(virt_to_page((void *)addr), order);
4998 while (used < alloc_end) {
5003 return (void *)addr;
5007 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5008 * @size: the number of bytes to allocate
5009 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5011 * This function is similar to alloc_pages(), except that it allocates the
5012 * minimum number of pages to satisfy the request. alloc_pages() can only
5013 * allocate memory in power-of-two pages.
5015 * This function is also limited by MAX_ORDER.
5017 * Memory allocated by this function must be released by free_pages_exact().
5019 * Return: pointer to the allocated area or %NULL in case of error.
5021 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
5023 unsigned int order = get_order(size);
5026 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5027 gfp_mask &= ~__GFP_COMP;
5029 addr = __get_free_pages(gfp_mask, order);
5030 return make_alloc_exact(addr, order, size);
5032 EXPORT_SYMBOL(alloc_pages_exact);
5035 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5037 * @nid: the preferred node ID where memory should be allocated
5038 * @size: the number of bytes to allocate
5039 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5041 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5044 * Return: pointer to the allocated area or %NULL in case of error.
5046 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
5048 unsigned int order = get_order(size);
5051 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5052 gfp_mask &= ~__GFP_COMP;
5054 p = alloc_pages_node(nid, gfp_mask, order);
5057 return make_alloc_exact((unsigned long)page_address(p), order, size);
5061 * free_pages_exact - release memory allocated via alloc_pages_exact()
5062 * @virt: the value returned by alloc_pages_exact.
5063 * @size: size of allocation, same value as passed to alloc_pages_exact().
5065 * Release the memory allocated by a previous call to alloc_pages_exact.
5067 void free_pages_exact(void *virt, size_t size)
5069 unsigned long addr = (unsigned long)virt;
5070 unsigned long end = addr + PAGE_ALIGN(size);
5072 while (addr < end) {
5077 EXPORT_SYMBOL(free_pages_exact);
5080 * nr_free_zone_pages - count number of pages beyond high watermark
5081 * @offset: The zone index of the highest zone
5083 * nr_free_zone_pages() counts the number of pages which are beyond the
5084 * high watermark within all zones at or below a given zone index. For each
5085 * zone, the number of pages is calculated as:
5087 * nr_free_zone_pages = managed_pages - high_pages
5089 * Return: number of pages beyond high watermark.
5091 static unsigned long nr_free_zone_pages(int offset)
5096 /* Just pick one node, since fallback list is circular */
5097 unsigned long sum = 0;
5099 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
5101 for_each_zone_zonelist(zone, z, zonelist, offset) {
5102 unsigned long size = zone_managed_pages(zone);
5103 unsigned long high = high_wmark_pages(zone);
5112 * nr_free_buffer_pages - count number of pages beyond high watermark
5114 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5115 * watermark within ZONE_DMA and ZONE_NORMAL.
5117 * Return: number of pages beyond high watermark within ZONE_DMA and
5120 unsigned long nr_free_buffer_pages(void)
5122 return nr_free_zone_pages(gfp_zone(GFP_USER));
5124 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
5127 * nr_free_pagecache_pages - count number of pages beyond high watermark
5129 * nr_free_pagecache_pages() counts the number of pages which are beyond the
5130 * high watermark within all zones.
5132 * Return: number of pages beyond high watermark within all zones.
5134 unsigned long nr_free_pagecache_pages(void)
5136 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
5139 static inline void show_node(struct zone *zone)
5141 if (IS_ENABLED(CONFIG_NUMA))
5142 printk("Node %d ", zone_to_nid(zone));
5145 long si_mem_available(void)
5148 unsigned long pagecache;
5149 unsigned long wmark_low = 0;
5150 unsigned long pages[NR_LRU_LISTS];
5151 unsigned long reclaimable;
5155 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
5156 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
5159 wmark_low += low_wmark_pages(zone);
5162 * Estimate the amount of memory available for userspace allocations,
5163 * without causing swapping.
5165 available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
5168 * Not all the page cache can be freed, otherwise the system will
5169 * start swapping. Assume at least half of the page cache, or the
5170 * low watermark worth of cache, needs to stay.
5172 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
5173 pagecache -= min(pagecache / 2, wmark_low);
5174 available += pagecache;
5177 * Part of the reclaimable slab and other kernel memory consists of
5178 * items that are in use, and cannot be freed. Cap this estimate at the
5181 reclaimable = global_node_page_state(NR_SLAB_RECLAIMABLE) +
5182 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE);
5183 available += reclaimable - min(reclaimable / 2, wmark_low);
5189 EXPORT_SYMBOL_GPL(si_mem_available);
5191 void si_meminfo(struct sysinfo *val)
5193 val->totalram = totalram_pages();
5194 val->sharedram = global_node_page_state(NR_SHMEM);
5195 val->freeram = global_zone_page_state(NR_FREE_PAGES);
5196 val->bufferram = nr_blockdev_pages();
5197 val->totalhigh = totalhigh_pages();
5198 val->freehigh = nr_free_highpages();
5199 val->mem_unit = PAGE_SIZE;
5202 EXPORT_SYMBOL(si_meminfo);
5205 void si_meminfo_node(struct sysinfo *val, int nid)
5207 int zone_type; /* needs to be signed */
5208 unsigned long managed_pages = 0;
5209 unsigned long managed_highpages = 0;
5210 unsigned long free_highpages = 0;
5211 pg_data_t *pgdat = NODE_DATA(nid);
5213 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
5214 managed_pages += zone_managed_pages(&pgdat->node_zones[zone_type]);
5215 val->totalram = managed_pages;
5216 val->sharedram = node_page_state(pgdat, NR_SHMEM);
5217 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
5218 #ifdef CONFIG_HIGHMEM
5219 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
5220 struct zone *zone = &pgdat->node_zones[zone_type];
5222 if (is_highmem(zone)) {
5223 managed_highpages += zone_managed_pages(zone);
5224 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
5227 val->totalhigh = managed_highpages;
5228 val->freehigh = free_highpages;
5230 val->totalhigh = managed_highpages;
5231 val->freehigh = free_highpages;
5233 val->mem_unit = PAGE_SIZE;
5238 * Determine whether the node should be displayed or not, depending on whether
5239 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5241 static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
5243 if (!(flags & SHOW_MEM_FILTER_NODES))
5247 * no node mask - aka implicit memory numa policy. Do not bother with
5248 * the synchronization - read_mems_allowed_begin - because we do not
5249 * have to be precise here.
5252 nodemask = &cpuset_current_mems_allowed;
5254 return !node_isset(nid, *nodemask);
5257 #define K(x) ((x) << (PAGE_SHIFT-10))
5259 static void show_migration_types(unsigned char type)
5261 static const char types[MIGRATE_TYPES] = {
5262 [MIGRATE_UNMOVABLE] = 'U',
5263 [MIGRATE_MOVABLE] = 'M',
5264 [MIGRATE_RECLAIMABLE] = 'E',
5265 [MIGRATE_HIGHATOMIC] = 'H',
5267 [MIGRATE_CMA] = 'C',
5269 #ifdef CONFIG_MEMORY_ISOLATION
5270 [MIGRATE_ISOLATE] = 'I',
5273 char tmp[MIGRATE_TYPES + 1];
5277 for (i = 0; i < MIGRATE_TYPES; i++) {
5278 if (type & (1 << i))
5283 printk(KERN_CONT "(%s) ", tmp);
5287 * Show free area list (used inside shift_scroll-lock stuff)
5288 * We also calculate the percentage fragmentation. We do this by counting the
5289 * memory on each free list with the exception of the first item on the list.
5292 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5295 void show_free_areas(unsigned int filter, nodemask_t *nodemask)
5297 unsigned long free_pcp = 0;
5302 for_each_populated_zone(zone) {
5303 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5306 for_each_online_cpu(cpu)
5307 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
5310 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5311 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5312 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
5313 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5314 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5315 " free:%lu free_pcp:%lu free_cma:%lu\n",
5316 global_node_page_state(NR_ACTIVE_ANON),
5317 global_node_page_state(NR_INACTIVE_ANON),
5318 global_node_page_state(NR_ISOLATED_ANON),
5319 global_node_page_state(NR_ACTIVE_FILE),
5320 global_node_page_state(NR_INACTIVE_FILE),
5321 global_node_page_state(NR_ISOLATED_FILE),
5322 global_node_page_state(NR_UNEVICTABLE),
5323 global_node_page_state(NR_FILE_DIRTY),
5324 global_node_page_state(NR_WRITEBACK),
5325 global_node_page_state(NR_UNSTABLE_NFS),
5326 global_node_page_state(NR_SLAB_RECLAIMABLE),
5327 global_node_page_state(NR_SLAB_UNRECLAIMABLE),
5328 global_node_page_state(NR_FILE_MAPPED),
5329 global_node_page_state(NR_SHMEM),
5330 global_zone_page_state(NR_PAGETABLE),
5331 global_zone_page_state(NR_BOUNCE),
5332 global_zone_page_state(NR_FREE_PAGES),
5334 global_zone_page_state(NR_FREE_CMA_PAGES));
5336 for_each_online_pgdat(pgdat) {
5337 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
5341 " active_anon:%lukB"
5342 " inactive_anon:%lukB"
5343 " active_file:%lukB"
5344 " inactive_file:%lukB"
5345 " unevictable:%lukB"
5346 " isolated(anon):%lukB"
5347 " isolated(file):%lukB"
5352 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5354 " shmem_pmdmapped: %lukB"
5357 " writeback_tmp:%lukB"
5359 " all_unreclaimable? %s"
5362 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
5363 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
5364 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
5365 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
5366 K(node_page_state(pgdat, NR_UNEVICTABLE)),
5367 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
5368 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
5369 K(node_page_state(pgdat, NR_FILE_MAPPED)),
5370 K(node_page_state(pgdat, NR_FILE_DIRTY)),
5371 K(node_page_state(pgdat, NR_WRITEBACK)),
5372 K(node_page_state(pgdat, NR_SHMEM)),
5373 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5374 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
5375 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
5377 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
5379 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
5380 K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
5381 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
5385 for_each_populated_zone(zone) {
5388 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5392 for_each_online_cpu(cpu)
5393 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
5402 " reserved_highatomic:%luKB"
5403 " active_anon:%lukB"
5404 " inactive_anon:%lukB"
5405 " active_file:%lukB"
5406 " inactive_file:%lukB"
5407 " unevictable:%lukB"
5408 " writepending:%lukB"
5412 " kernel_stack:%lukB"
5420 K(zone_page_state(zone, NR_FREE_PAGES)),
5421 K(min_wmark_pages(zone)),
5422 K(low_wmark_pages(zone)),
5423 K(high_wmark_pages(zone)),
5424 K(zone->nr_reserved_highatomic),
5425 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
5426 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
5427 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
5428 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
5429 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
5430 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
5431 K(zone->present_pages),
5432 K(zone_managed_pages(zone)),
5433 K(zone_page_state(zone, NR_MLOCK)),
5434 zone_page_state(zone, NR_KERNEL_STACK_KB),
5435 K(zone_page_state(zone, NR_PAGETABLE)),
5436 K(zone_page_state(zone, NR_BOUNCE)),
5438 K(this_cpu_read(zone->pageset->pcp.count)),
5439 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
5440 printk("lowmem_reserve[]:");
5441 for (i = 0; i < MAX_NR_ZONES; i++)
5442 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
5443 printk(KERN_CONT "\n");
5446 for_each_populated_zone(zone) {
5448 unsigned long nr[MAX_ORDER], flags, total = 0;
5449 unsigned char types[MAX_ORDER];
5451 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5454 printk(KERN_CONT "%s: ", zone->name);
5456 spin_lock_irqsave(&zone->lock, flags);
5457 for (order = 0; order < MAX_ORDER; order++) {
5458 struct free_area *area = &zone->free_area[order];
5461 nr[order] = area->nr_free;
5462 total += nr[order] << order;
5465 for (type = 0; type < MIGRATE_TYPES; type++) {
5466 if (!free_area_empty(area, type))
5467 types[order] |= 1 << type;
5470 spin_unlock_irqrestore(&zone->lock, flags);
5471 for (order = 0; order < MAX_ORDER; order++) {
5472 printk(KERN_CONT "%lu*%lukB ",
5473 nr[order], K(1UL) << order);
5475 show_migration_types(types[order]);
5477 printk(KERN_CONT "= %lukB\n", K(total));
5480 hugetlb_show_meminfo();
5482 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
5484 show_swap_cache_info();
5487 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
5489 zoneref->zone = zone;
5490 zoneref->zone_idx = zone_idx(zone);
5494 * Builds allocation fallback zone lists.
5496 * Add all populated zones of a node to the zonelist.
5498 static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
5501 enum zone_type zone_type = MAX_NR_ZONES;
5506 zone = pgdat->node_zones + zone_type;
5507 if (managed_zone(zone)) {
5508 zoneref_set_zone(zone, &zonerefs[nr_zones++]);
5509 check_highest_zone(zone_type);
5511 } while (zone_type);
5518 static int __parse_numa_zonelist_order(char *s)
5521 * We used to support different zonlists modes but they turned
5522 * out to be just not useful. Let's keep the warning in place
5523 * if somebody still use the cmd line parameter so that we do
5524 * not fail it silently
5526 if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
5527 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
5533 static __init int setup_numa_zonelist_order(char *s)
5538 return __parse_numa_zonelist_order(s);
5540 early_param("numa_zonelist_order", setup_numa_zonelist_order);
5542 char numa_zonelist_order[] = "Node";
5545 * sysctl handler for numa_zonelist_order
5547 int numa_zonelist_order_handler(struct ctl_table *table, int write,
5548 void __user *buffer, size_t *length,
5555 return proc_dostring(table, write, buffer, length, ppos);
5556 str = memdup_user_nul(buffer, 16);
5558 return PTR_ERR(str);
5560 ret = __parse_numa_zonelist_order(str);
5566 #define MAX_NODE_LOAD (nr_online_nodes)
5567 static int node_load[MAX_NUMNODES];
5570 * find_next_best_node - find the next node that should appear in a given node's fallback list
5571 * @node: node whose fallback list we're appending
5572 * @used_node_mask: nodemask_t of already used nodes
5574 * We use a number of factors to determine which is the next node that should
5575 * appear on a given node's fallback list. The node should not have appeared
5576 * already in @node's fallback list, and it should be the next closest node
5577 * according to the distance array (which contains arbitrary distance values
5578 * from each node to each node in the system), and should also prefer nodes
5579 * with no CPUs, since presumably they'll have very little allocation pressure
5580 * on them otherwise.
5582 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5584 static int find_next_best_node(int node, nodemask_t *used_node_mask)
5587 int min_val = INT_MAX;
5588 int best_node = NUMA_NO_NODE;
5589 const struct cpumask *tmp = cpumask_of_node(0);
5591 /* Use the local node if we haven't already */
5592 if (!node_isset(node, *used_node_mask)) {
5593 node_set(node, *used_node_mask);
5597 for_each_node_state(n, N_MEMORY) {
5599 /* Don't want a node to appear more than once */
5600 if (node_isset(n, *used_node_mask))
5603 /* Use the distance array to find the distance */
5604 val = node_distance(node, n);
5606 /* Penalize nodes under us ("prefer the next node") */
5609 /* Give preference to headless and unused nodes */
5610 tmp = cpumask_of_node(n);
5611 if (!cpumask_empty(tmp))
5612 val += PENALTY_FOR_NODE_WITH_CPUS;
5614 /* Slight preference for less loaded node */
5615 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
5616 val += node_load[n];
5618 if (val < min_val) {
5625 node_set(best_node, *used_node_mask);
5632 * Build zonelists ordered by node and zones within node.
5633 * This results in maximum locality--normal zone overflows into local
5634 * DMA zone, if any--but risks exhausting DMA zone.
5636 static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
5639 struct zoneref *zonerefs;
5642 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5644 for (i = 0; i < nr_nodes; i++) {
5647 pg_data_t *node = NODE_DATA(node_order[i]);
5649 nr_zones = build_zonerefs_node(node, zonerefs);
5650 zonerefs += nr_zones;
5652 zonerefs->zone = NULL;
5653 zonerefs->zone_idx = 0;
5657 * Build gfp_thisnode zonelists
5659 static void build_thisnode_zonelists(pg_data_t *pgdat)
5661 struct zoneref *zonerefs;
5664 zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
5665 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5666 zonerefs += nr_zones;
5667 zonerefs->zone = NULL;
5668 zonerefs->zone_idx = 0;
5672 * Build zonelists ordered by zone and nodes within zones.
5673 * This results in conserving DMA zone[s] until all Normal memory is
5674 * exhausted, but results in overflowing to remote node while memory
5675 * may still exist in local DMA zone.
5678 static void build_zonelists(pg_data_t *pgdat)
5680 static int node_order[MAX_NUMNODES];
5681 int node, load, nr_nodes = 0;
5682 nodemask_t used_mask;
5683 int local_node, prev_node;
5685 /* NUMA-aware ordering of nodes */
5686 local_node = pgdat->node_id;
5687 load = nr_online_nodes;
5688 prev_node = local_node;
5689 nodes_clear(used_mask);
5691 memset(node_order, 0, sizeof(node_order));
5692 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
5694 * We don't want to pressure a particular node.
5695 * So adding penalty to the first node in same
5696 * distance group to make it round-robin.
5698 if (node_distance(local_node, node) !=
5699 node_distance(local_node, prev_node))
5700 node_load[node] = load;
5702 node_order[nr_nodes++] = node;
5707 build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
5708 build_thisnode_zonelists(pgdat);
5711 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5713 * Return node id of node used for "local" allocations.
5714 * I.e., first node id of first zone in arg node's generic zonelist.
5715 * Used for initializing percpu 'numa_mem', which is used primarily
5716 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5718 int local_memory_node(int node)
5722 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
5723 gfp_zone(GFP_KERNEL),
5725 return zone_to_nid(z->zone);
5729 static void setup_min_unmapped_ratio(void);
5730 static void setup_min_slab_ratio(void);
5731 #else /* CONFIG_NUMA */
5733 static void build_zonelists(pg_data_t *pgdat)
5735 int node, local_node;
5736 struct zoneref *zonerefs;
5739 local_node = pgdat->node_id;
5741 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5742 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5743 zonerefs += nr_zones;
5746 * Now we build the zonelist so that it contains the zones
5747 * of all the other nodes.
5748 * We don't want to pressure a particular node, so when
5749 * building the zones for node N, we make sure that the
5750 * zones coming right after the local ones are those from
5751 * node N+1 (modulo N)
5753 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
5754 if (!node_online(node))
5756 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5757 zonerefs += nr_zones;
5759 for (node = 0; node < local_node; node++) {
5760 if (!node_online(node))
5762 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5763 zonerefs += nr_zones;
5766 zonerefs->zone = NULL;
5767 zonerefs->zone_idx = 0;
5770 #endif /* CONFIG_NUMA */
5773 * Boot pageset table. One per cpu which is going to be used for all
5774 * zones and all nodes. The parameters will be set in such a way
5775 * that an item put on a list will immediately be handed over to
5776 * the buddy list. This is safe since pageset manipulation is done
5777 * with interrupts disabled.
5779 * The boot_pagesets must be kept even after bootup is complete for
5780 * unused processors and/or zones. They do play a role for bootstrapping
5781 * hotplugged processors.
5783 * zoneinfo_show() and maybe other functions do
5784 * not check if the processor is online before following the pageset pointer.
5785 * Other parts of the kernel may not check if the zone is available.
5787 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
5788 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
5789 static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
5791 static void __build_all_zonelists(void *data)
5794 int __maybe_unused cpu;
5795 pg_data_t *self = data;
5796 static DEFINE_SPINLOCK(lock);
5801 memset(node_load, 0, sizeof(node_load));
5805 * This node is hotadded and no memory is yet present. So just
5806 * building zonelists is fine - no need to touch other nodes.
5808 if (self && !node_online(self->node_id)) {
5809 build_zonelists(self);
5811 for_each_online_node(nid) {
5812 pg_data_t *pgdat = NODE_DATA(nid);
5814 build_zonelists(pgdat);
5817 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5819 * We now know the "local memory node" for each node--
5820 * i.e., the node of the first zone in the generic zonelist.
5821 * Set up numa_mem percpu variable for on-line cpus. During
5822 * boot, only the boot cpu should be on-line; we'll init the
5823 * secondary cpus' numa_mem as they come on-line. During
5824 * node/memory hotplug, we'll fixup all on-line cpus.
5826 for_each_online_cpu(cpu)
5827 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
5834 static noinline void __init
5835 build_all_zonelists_init(void)
5839 __build_all_zonelists(NULL);
5842 * Initialize the boot_pagesets that are going to be used
5843 * for bootstrapping processors. The real pagesets for
5844 * each zone will be allocated later when the per cpu
5845 * allocator is available.
5847 * boot_pagesets are used also for bootstrapping offline
5848 * cpus if the system is already booted because the pagesets
5849 * are needed to initialize allocators on a specific cpu too.
5850 * F.e. the percpu allocator needs the page allocator which
5851 * needs the percpu allocator in order to allocate its pagesets
5852 * (a chicken-egg dilemma).
5854 for_each_possible_cpu(cpu)
5855 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
5857 mminit_verify_zonelist();
5858 cpuset_init_current_mems_allowed();
5862 * unless system_state == SYSTEM_BOOTING.
5864 * __ref due to call of __init annotated helper build_all_zonelists_init
5865 * [protected by SYSTEM_BOOTING].
5867 void __ref build_all_zonelists(pg_data_t *pgdat)
5869 if (system_state == SYSTEM_BOOTING) {
5870 build_all_zonelists_init();
5872 __build_all_zonelists(pgdat);
5873 /* cpuset refresh routine should be here */
5875 vm_total_pages = nr_free_pagecache_pages();
5877 * Disable grouping by mobility if the number of pages in the
5878 * system is too low to allow the mechanism to work. It would be
5879 * more accurate, but expensive to check per-zone. This check is
5880 * made on memory-hotadd so a system can start with mobility
5881 * disabled and enable it later
5883 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5884 page_group_by_mobility_disabled = 1;
5886 page_group_by_mobility_disabled = 0;
5888 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
5890 page_group_by_mobility_disabled ? "off" : "on",
5893 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5897 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
5898 static bool __meminit
5899 overlap_memmap_init(unsigned long zone, unsigned long *pfn)
5901 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5902 static struct memblock_region *r;
5904 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5905 if (!r || *pfn >= memblock_region_memory_end_pfn(r)) {
5906 for_each_memblock(memory, r) {
5907 if (*pfn < memblock_region_memory_end_pfn(r))
5911 if (*pfn >= memblock_region_memory_base_pfn(r) &&
5912 memblock_is_mirror(r)) {
5913 *pfn = memblock_region_memory_end_pfn(r);
5921 #ifdef CONFIG_SPARSEMEM
5922 /* Skip PFNs that belong to non-present sections */
5923 static inline __meminit unsigned long next_pfn(unsigned long pfn)
5925 const unsigned long section_nr = pfn_to_section_nr(++pfn);
5927 if (present_section_nr(section_nr))
5929 return section_nr_to_pfn(next_present_section_nr(section_nr));
5932 static inline __meminit unsigned long next_pfn(unsigned long pfn)
5939 * Initially all pages are reserved - free ones are freed
5940 * up by memblock_free_all() once the early boot process is
5941 * done. Non-atomic initialization, single-pass.
5943 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5944 unsigned long start_pfn, enum memmap_context context,
5945 struct vmem_altmap *altmap)
5947 unsigned long pfn, end_pfn = start_pfn + size;
5950 if (highest_memmap_pfn < end_pfn - 1)
5951 highest_memmap_pfn = end_pfn - 1;
5953 #ifdef CONFIG_ZONE_DEVICE
5955 * Honor reservation requested by the driver for this ZONE_DEVICE
5956 * memory. We limit the total number of pages to initialize to just
5957 * those that might contain the memory mapping. We will defer the
5958 * ZONE_DEVICE page initialization until after we have released
5961 if (zone == ZONE_DEVICE) {
5965 if (start_pfn == altmap->base_pfn)
5966 start_pfn += altmap->reserve;
5967 end_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
5971 for (pfn = start_pfn; pfn < end_pfn; ) {
5973 * There can be holes in boot-time mem_map[]s handed to this
5974 * function. They do not exist on hotplugged memory.
5976 if (context == MEMMAP_EARLY) {
5977 if (!early_pfn_valid(pfn)) {
5978 pfn = next_pfn(pfn);
5981 if (!early_pfn_in_nid(pfn, nid)) {
5985 if (overlap_memmap_init(zone, &pfn))
5987 if (defer_init(nid, pfn, end_pfn))
5991 page = pfn_to_page(pfn);
5992 __init_single_page(page, pfn, zone, nid);
5993 if (context == MEMMAP_HOTPLUG)
5994 __SetPageReserved(page);
5997 * Mark the block movable so that blocks are reserved for
5998 * movable at startup. This will force kernel allocations
5999 * to reserve their blocks rather than leaking throughout
6000 * the address space during boot when many long-lived
6001 * kernel allocations are made.
6003 * bitmap is created for zone's valid pfn range. but memmap
6004 * can be created for invalid pages (for alignment)
6005 * check here not to call set_pageblock_migratetype() against
6008 if (!(pfn & (pageblock_nr_pages - 1))) {
6009 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
6016 #ifdef CONFIG_ZONE_DEVICE
6017 void __ref memmap_init_zone_device(struct zone *zone,
6018 unsigned long start_pfn,
6019 unsigned long nr_pages,
6020 struct dev_pagemap *pgmap)
6022 unsigned long pfn, end_pfn = start_pfn + nr_pages;
6023 struct pglist_data *pgdat = zone->zone_pgdat;
6024 struct vmem_altmap *altmap = pgmap_altmap(pgmap);
6025 unsigned long zone_idx = zone_idx(zone);
6026 unsigned long start = jiffies;
6027 int nid = pgdat->node_id;
6029 if (WARN_ON_ONCE(!pgmap || zone_idx(zone) != ZONE_DEVICE))
6033 * The call to memmap_init_zone should have already taken care
6034 * of the pages reserved for the memmap, so we can just jump to
6035 * the end of that region and start processing the device pages.
6038 start_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6039 nr_pages = end_pfn - start_pfn;
6042 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
6043 struct page *page = pfn_to_page(pfn);
6045 __init_single_page(page, pfn, zone_idx, nid);
6048 * Mark page reserved as it will need to wait for onlining
6049 * phase for it to be fully associated with a zone.
6051 * We can use the non-atomic __set_bit operation for setting
6052 * the flag as we are still initializing the pages.
6054 __SetPageReserved(page);
6057 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6058 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6059 * ever freed or placed on a driver-private list.
6061 page->pgmap = pgmap;
6062 page->zone_device_data = NULL;
6065 * Mark the block movable so that blocks are reserved for
6066 * movable at startup. This will force kernel allocations
6067 * to reserve their blocks rather than leaking throughout
6068 * the address space during boot when many long-lived
6069 * kernel allocations are made.
6071 * bitmap is created for zone's valid pfn range. but memmap
6072 * can be created for invalid pages (for alignment)
6073 * check here not to call set_pageblock_migratetype() against
6076 * Please note that MEMMAP_HOTPLUG path doesn't clear memmap
6077 * because this is done early in section_activate()
6079 if (!(pfn & (pageblock_nr_pages - 1))) {
6080 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
6085 pr_info("%s initialised %lu pages in %ums\n", __func__,
6086 nr_pages, jiffies_to_msecs(jiffies - start));
6090 static void __meminit zone_init_free_lists(struct zone *zone)
6092 unsigned int order, t;
6093 for_each_migratetype_order(order, t) {
6094 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
6095 zone->free_area[order].nr_free = 0;
6099 void __meminit __weak memmap_init(unsigned long size, int nid,
6100 unsigned long zone, unsigned long start_pfn)
6102 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY, NULL);
6105 static int zone_batchsize(struct zone *zone)
6111 * The per-cpu-pages pools are set to around 1000th of the
6114 batch = zone_managed_pages(zone) / 1024;
6115 /* But no more than a meg. */
6116 if (batch * PAGE_SIZE > 1024 * 1024)
6117 batch = (1024 * 1024) / PAGE_SIZE;
6118 batch /= 4; /* We effectively *= 4 below */
6123 * Clamp the batch to a 2^n - 1 value. Having a power
6124 * of 2 value was found to be more likely to have
6125 * suboptimal cache aliasing properties in some cases.
6127 * For example if 2 tasks are alternately allocating
6128 * batches of pages, one task can end up with a lot
6129 * of pages of one half of the possible page colors
6130 * and the other with pages of the other colors.
6132 batch = rounddown_pow_of_two(batch + batch/2) - 1;
6137 /* The deferral and batching of frees should be suppressed under NOMMU
6140 * The problem is that NOMMU needs to be able to allocate large chunks
6141 * of contiguous memory as there's no hardware page translation to
6142 * assemble apparent contiguous memory from discontiguous pages.
6144 * Queueing large contiguous runs of pages for batching, however,
6145 * causes the pages to actually be freed in smaller chunks. As there
6146 * can be a significant delay between the individual batches being
6147 * recycled, this leads to the once large chunks of space being
6148 * fragmented and becoming unavailable for high-order allocations.
6155 * pcp->high and pcp->batch values are related and dependent on one another:
6156 * ->batch must never be higher then ->high.
6157 * The following function updates them in a safe manner without read side
6160 * Any new users of pcp->batch and pcp->high should ensure they can cope with
6161 * those fields changing asynchronously (acording the the above rule).
6163 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6164 * outside of boot time (or some other assurance that no concurrent updaters
6167 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
6168 unsigned long batch)
6170 /* start with a fail safe value for batch */
6174 /* Update high, then batch, in order */
6181 /* a companion to pageset_set_high() */
6182 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
6184 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
6187 static void pageset_init(struct per_cpu_pageset *p)
6189 struct per_cpu_pages *pcp;
6192 memset(p, 0, sizeof(*p));
6195 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
6196 INIT_LIST_HEAD(&pcp->lists[migratetype]);
6199 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
6202 pageset_set_batch(p, batch);
6206 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
6207 * to the value high for the pageset p.
6209 static void pageset_set_high(struct per_cpu_pageset *p,
6212 unsigned long batch = max(1UL, high / 4);
6213 if ((high / 4) > (PAGE_SHIFT * 8))
6214 batch = PAGE_SHIFT * 8;
6216 pageset_update(&p->pcp, high, batch);
6219 static void pageset_set_high_and_batch(struct zone *zone,
6220 struct per_cpu_pageset *pcp)
6222 if (percpu_pagelist_fraction)
6223 pageset_set_high(pcp,
6224 (zone_managed_pages(zone) /
6225 percpu_pagelist_fraction));
6227 pageset_set_batch(pcp, zone_batchsize(zone));
6230 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
6232 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
6235 pageset_set_high_and_batch(zone, pcp);
6238 void __meminit setup_zone_pageset(struct zone *zone)
6241 zone->pageset = alloc_percpu(struct per_cpu_pageset);
6242 for_each_possible_cpu(cpu)
6243 zone_pageset_init(zone, cpu);
6247 * Allocate per cpu pagesets and initialize them.
6248 * Before this call only boot pagesets were available.
6250 void __init setup_per_cpu_pageset(void)
6252 struct pglist_data *pgdat;
6255 for_each_populated_zone(zone)
6256 setup_zone_pageset(zone);
6258 for_each_online_pgdat(pgdat)
6259 pgdat->per_cpu_nodestats =
6260 alloc_percpu(struct per_cpu_nodestat);
6263 static __meminit void zone_pcp_init(struct zone *zone)
6266 * per cpu subsystem is not up at this point. The following code
6267 * relies on the ability of the linker to provide the
6268 * offset of a (static) per cpu variable into the per cpu area.
6270 zone->pageset = &boot_pageset;
6272 if (populated_zone(zone))
6273 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
6274 zone->name, zone->present_pages,
6275 zone_batchsize(zone));
6278 void __meminit init_currently_empty_zone(struct zone *zone,
6279 unsigned long zone_start_pfn,
6282 struct pglist_data *pgdat = zone->zone_pgdat;
6283 int zone_idx = zone_idx(zone) + 1;
6285 if (zone_idx > pgdat->nr_zones)
6286 pgdat->nr_zones = zone_idx;
6288 zone->zone_start_pfn = zone_start_pfn;
6290 mminit_dprintk(MMINIT_TRACE, "memmap_init",
6291 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6293 (unsigned long)zone_idx(zone),
6294 zone_start_pfn, (zone_start_pfn + size));
6296 zone_init_free_lists(zone);
6297 zone->initialized = 1;
6300 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6301 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
6304 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
6306 int __meminit __early_pfn_to_nid(unsigned long pfn,
6307 struct mminit_pfnnid_cache *state)
6309 unsigned long start_pfn, end_pfn;
6312 if (state->last_start <= pfn && pfn < state->last_end)
6313 return state->last_nid;
6315 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
6316 if (nid != NUMA_NO_NODE) {
6317 state->last_start = start_pfn;
6318 state->last_end = end_pfn;
6319 state->last_nid = nid;
6324 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
6327 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
6328 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
6329 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
6331 * If an architecture guarantees that all ranges registered contain no holes
6332 * and may be freed, this this function may be used instead of calling
6333 * memblock_free_early_nid() manually.
6335 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
6337 unsigned long start_pfn, end_pfn;
6340 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
6341 start_pfn = min(start_pfn, max_low_pfn);
6342 end_pfn = min(end_pfn, max_low_pfn);
6344 if (start_pfn < end_pfn)
6345 memblock_free_early_nid(PFN_PHYS(start_pfn),
6346 (end_pfn - start_pfn) << PAGE_SHIFT,
6352 * sparse_memory_present_with_active_regions - Call memory_present for each active range
6353 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
6355 * If an architecture guarantees that all ranges registered contain no holes and may
6356 * be freed, this function may be used instead of calling memory_present() manually.
6358 void __init sparse_memory_present_with_active_regions(int nid)
6360 unsigned long start_pfn, end_pfn;
6363 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
6364 memory_present(this_nid, start_pfn, end_pfn);
6368 * get_pfn_range_for_nid - Return the start and end page frames for a node
6369 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6370 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6371 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6373 * It returns the start and end page frame of a node based on information
6374 * provided by memblock_set_node(). If called for a node
6375 * with no available memory, a warning is printed and the start and end
6378 void __init get_pfn_range_for_nid(unsigned int nid,
6379 unsigned long *start_pfn, unsigned long *end_pfn)
6381 unsigned long this_start_pfn, this_end_pfn;
6387 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
6388 *start_pfn = min(*start_pfn, this_start_pfn);
6389 *end_pfn = max(*end_pfn, this_end_pfn);
6392 if (*start_pfn == -1UL)
6397 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6398 * assumption is made that zones within a node are ordered in monotonic
6399 * increasing memory addresses so that the "highest" populated zone is used
6401 static void __init find_usable_zone_for_movable(void)
6404 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
6405 if (zone_index == ZONE_MOVABLE)
6408 if (arch_zone_highest_possible_pfn[zone_index] >
6409 arch_zone_lowest_possible_pfn[zone_index])
6413 VM_BUG_ON(zone_index == -1);
6414 movable_zone = zone_index;
6418 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6419 * because it is sized independent of architecture. Unlike the other zones,
6420 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6421 * in each node depending on the size of each node and how evenly kernelcore
6422 * is distributed. This helper function adjusts the zone ranges
6423 * provided by the architecture for a given node by using the end of the
6424 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6425 * zones within a node are in order of monotonic increases memory addresses
6427 static void __init adjust_zone_range_for_zone_movable(int nid,
6428 unsigned long zone_type,
6429 unsigned long node_start_pfn,
6430 unsigned long node_end_pfn,
6431 unsigned long *zone_start_pfn,
6432 unsigned long *zone_end_pfn)
6434 /* Only adjust if ZONE_MOVABLE is on this node */
6435 if (zone_movable_pfn[nid]) {
6436 /* Size ZONE_MOVABLE */
6437 if (zone_type == ZONE_MOVABLE) {
6438 *zone_start_pfn = zone_movable_pfn[nid];
6439 *zone_end_pfn = min(node_end_pfn,
6440 arch_zone_highest_possible_pfn[movable_zone]);
6442 /* Adjust for ZONE_MOVABLE starting within this range */
6443 } else if (!mirrored_kernelcore &&
6444 *zone_start_pfn < zone_movable_pfn[nid] &&
6445 *zone_end_pfn > zone_movable_pfn[nid]) {
6446 *zone_end_pfn = zone_movable_pfn[nid];
6448 /* Check if this whole range is within ZONE_MOVABLE */
6449 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
6450 *zone_start_pfn = *zone_end_pfn;
6455 * Return the number of pages a zone spans in a node, including holes
6456 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6458 static unsigned long __init zone_spanned_pages_in_node(int nid,
6459 unsigned long zone_type,
6460 unsigned long node_start_pfn,
6461 unsigned long node_end_pfn,
6462 unsigned long *zone_start_pfn,
6463 unsigned long *zone_end_pfn,
6464 unsigned long *ignored)
6466 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6467 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6468 /* When hotadd a new node from cpu_up(), the node should be empty */
6469 if (!node_start_pfn && !node_end_pfn)
6472 /* Get the start and end of the zone */
6473 *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6474 *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6475 adjust_zone_range_for_zone_movable(nid, zone_type,
6476 node_start_pfn, node_end_pfn,
6477 zone_start_pfn, zone_end_pfn);
6479 /* Check that this node has pages within the zone's required range */
6480 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
6483 /* Move the zone boundaries inside the node if necessary */
6484 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
6485 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
6487 /* Return the spanned pages */
6488 return *zone_end_pfn - *zone_start_pfn;
6492 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6493 * then all holes in the requested range will be accounted for.
6495 unsigned long __init __absent_pages_in_range(int nid,
6496 unsigned long range_start_pfn,
6497 unsigned long range_end_pfn)
6499 unsigned long nr_absent = range_end_pfn - range_start_pfn;
6500 unsigned long start_pfn, end_pfn;
6503 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6504 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
6505 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
6506 nr_absent -= end_pfn - start_pfn;
6512 * absent_pages_in_range - Return number of page frames in holes within a range
6513 * @start_pfn: The start PFN to start searching for holes
6514 * @end_pfn: The end PFN to stop searching for holes
6516 * Return: the number of pages frames in memory holes within a range.
6518 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
6519 unsigned long end_pfn)
6521 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
6524 /* Return the number of page frames in holes in a zone on a node */
6525 static unsigned long __init zone_absent_pages_in_node(int nid,
6526 unsigned long zone_type,
6527 unsigned long node_start_pfn,
6528 unsigned long node_end_pfn,
6529 unsigned long *ignored)
6531 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6532 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6533 unsigned long zone_start_pfn, zone_end_pfn;
6534 unsigned long nr_absent;
6536 /* When hotadd a new node from cpu_up(), the node should be empty */
6537 if (!node_start_pfn && !node_end_pfn)
6540 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6541 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6543 adjust_zone_range_for_zone_movable(nid, zone_type,
6544 node_start_pfn, node_end_pfn,
6545 &zone_start_pfn, &zone_end_pfn);
6546 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
6549 * ZONE_MOVABLE handling.
6550 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6553 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
6554 unsigned long start_pfn, end_pfn;
6555 struct memblock_region *r;
6557 for_each_memblock(memory, r) {
6558 start_pfn = clamp(memblock_region_memory_base_pfn(r),
6559 zone_start_pfn, zone_end_pfn);
6560 end_pfn = clamp(memblock_region_memory_end_pfn(r),
6561 zone_start_pfn, zone_end_pfn);
6563 if (zone_type == ZONE_MOVABLE &&
6564 memblock_is_mirror(r))
6565 nr_absent += end_pfn - start_pfn;
6567 if (zone_type == ZONE_NORMAL &&
6568 !memblock_is_mirror(r))
6569 nr_absent += end_pfn - start_pfn;
6576 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6577 static inline unsigned long __init zone_spanned_pages_in_node(int nid,
6578 unsigned long zone_type,
6579 unsigned long node_start_pfn,
6580 unsigned long node_end_pfn,
6581 unsigned long *zone_start_pfn,
6582 unsigned long *zone_end_pfn,
6583 unsigned long *zones_size)
6587 *zone_start_pfn = node_start_pfn;
6588 for (zone = 0; zone < zone_type; zone++)
6589 *zone_start_pfn += zones_size[zone];
6591 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
6593 return zones_size[zone_type];
6596 static inline unsigned long __init zone_absent_pages_in_node(int nid,
6597 unsigned long zone_type,
6598 unsigned long node_start_pfn,
6599 unsigned long node_end_pfn,
6600 unsigned long *zholes_size)
6605 return zholes_size[zone_type];
6608 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6610 static void __init calculate_node_totalpages(struct pglist_data *pgdat,
6611 unsigned long node_start_pfn,
6612 unsigned long node_end_pfn,
6613 unsigned long *zones_size,
6614 unsigned long *zholes_size)
6616 unsigned long realtotalpages = 0, totalpages = 0;
6619 for (i = 0; i < MAX_NR_ZONES; i++) {
6620 struct zone *zone = pgdat->node_zones + i;
6621 unsigned long zone_start_pfn, zone_end_pfn;
6622 unsigned long size, real_size;
6624 size = zone_spanned_pages_in_node(pgdat->node_id, i,
6630 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
6631 node_start_pfn, node_end_pfn,
6634 zone->zone_start_pfn = zone_start_pfn;
6636 zone->zone_start_pfn = 0;
6637 zone->spanned_pages = size;
6638 zone->present_pages = real_size;
6641 realtotalpages += real_size;
6644 pgdat->node_spanned_pages = totalpages;
6645 pgdat->node_present_pages = realtotalpages;
6646 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
6650 #ifndef CONFIG_SPARSEMEM
6652 * Calculate the size of the zone->blockflags rounded to an unsigned long
6653 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6654 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6655 * round what is now in bits to nearest long in bits, then return it in
6658 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
6660 unsigned long usemapsize;
6662 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
6663 usemapsize = roundup(zonesize, pageblock_nr_pages);
6664 usemapsize = usemapsize >> pageblock_order;
6665 usemapsize *= NR_PAGEBLOCK_BITS;
6666 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
6668 return usemapsize / 8;
6671 static void __ref setup_usemap(struct pglist_data *pgdat,
6673 unsigned long zone_start_pfn,
6674 unsigned long zonesize)
6676 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
6677 zone->pageblock_flags = NULL;
6679 zone->pageblock_flags =
6680 memblock_alloc_node(usemapsize, SMP_CACHE_BYTES,
6682 if (!zone->pageblock_flags)
6683 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6684 usemapsize, zone->name, pgdat->node_id);
6688 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
6689 unsigned long zone_start_pfn, unsigned long zonesize) {}
6690 #endif /* CONFIG_SPARSEMEM */
6692 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6694 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6695 void __init set_pageblock_order(void)
6699 /* Check that pageblock_nr_pages has not already been setup */
6700 if (pageblock_order)
6703 if (HPAGE_SHIFT > PAGE_SHIFT)
6704 order = HUGETLB_PAGE_ORDER;
6706 order = MAX_ORDER - 1;
6709 * Assume the largest contiguous order of interest is a huge page.
6710 * This value may be variable depending on boot parameters on IA64 and
6713 pageblock_order = order;
6715 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6718 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6719 * is unused as pageblock_order is set at compile-time. See
6720 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6723 void __init set_pageblock_order(void)
6727 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6729 static unsigned long __init calc_memmap_size(unsigned long spanned_pages,
6730 unsigned long present_pages)
6732 unsigned long pages = spanned_pages;
6735 * Provide a more accurate estimation if there are holes within
6736 * the zone and SPARSEMEM is in use. If there are holes within the
6737 * zone, each populated memory region may cost us one or two extra
6738 * memmap pages due to alignment because memmap pages for each
6739 * populated regions may not be naturally aligned on page boundary.
6740 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6742 if (spanned_pages > present_pages + (present_pages >> 4) &&
6743 IS_ENABLED(CONFIG_SPARSEMEM))
6744 pages = present_pages;
6746 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
6749 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6750 static void pgdat_init_split_queue(struct pglist_data *pgdat)
6752 struct deferred_split *ds_queue = &pgdat->deferred_split_queue;
6754 spin_lock_init(&ds_queue->split_queue_lock);
6755 INIT_LIST_HEAD(&ds_queue->split_queue);
6756 ds_queue->split_queue_len = 0;
6759 static void pgdat_init_split_queue(struct pglist_data *pgdat) {}
6762 #ifdef CONFIG_COMPACTION
6763 static void pgdat_init_kcompactd(struct pglist_data *pgdat)
6765 init_waitqueue_head(&pgdat->kcompactd_wait);
6768 static void pgdat_init_kcompactd(struct pglist_data *pgdat) {}
6771 static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
6773 pgdat_resize_init(pgdat);
6775 pgdat_init_split_queue(pgdat);
6776 pgdat_init_kcompactd(pgdat);
6778 init_waitqueue_head(&pgdat->kswapd_wait);
6779 init_waitqueue_head(&pgdat->pfmemalloc_wait);
6781 pgdat_page_ext_init(pgdat);
6782 spin_lock_init(&pgdat->lru_lock);
6783 lruvec_init(&pgdat->__lruvec);
6786 static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,
6787 unsigned long remaining_pages)
6789 atomic_long_set(&zone->managed_pages, remaining_pages);
6790 zone_set_nid(zone, nid);
6791 zone->name = zone_names[idx];
6792 zone->zone_pgdat = NODE_DATA(nid);
6793 spin_lock_init(&zone->lock);
6794 zone_seqlock_init(zone);
6795 zone_pcp_init(zone);
6799 * Set up the zone data structures
6800 * - init pgdat internals
6801 * - init all zones belonging to this node
6803 * NOTE: this function is only called during memory hotplug
6805 #ifdef CONFIG_MEMORY_HOTPLUG
6806 void __ref free_area_init_core_hotplug(int nid)
6809 pg_data_t *pgdat = NODE_DATA(nid);
6811 pgdat_init_internals(pgdat);
6812 for (z = 0; z < MAX_NR_ZONES; z++)
6813 zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
6818 * Set up the zone data structures:
6819 * - mark all pages reserved
6820 * - mark all memory queues empty
6821 * - clear the memory bitmaps
6823 * NOTE: pgdat should get zeroed by caller.
6824 * NOTE: this function is only called during early init.
6826 static void __init free_area_init_core(struct pglist_data *pgdat)
6829 int nid = pgdat->node_id;
6831 pgdat_init_internals(pgdat);
6832 pgdat->per_cpu_nodestats = &boot_nodestats;
6834 for (j = 0; j < MAX_NR_ZONES; j++) {
6835 struct zone *zone = pgdat->node_zones + j;
6836 unsigned long size, freesize, memmap_pages;
6837 unsigned long zone_start_pfn = zone->zone_start_pfn;
6839 size = zone->spanned_pages;
6840 freesize = zone->present_pages;
6843 * Adjust freesize so that it accounts for how much memory
6844 * is used by this zone for memmap. This affects the watermark
6845 * and per-cpu initialisations
6847 memmap_pages = calc_memmap_size(size, freesize);
6848 if (!is_highmem_idx(j)) {
6849 if (freesize >= memmap_pages) {
6850 freesize -= memmap_pages;
6853 " %s zone: %lu pages used for memmap\n",
6854 zone_names[j], memmap_pages);
6856 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6857 zone_names[j], memmap_pages, freesize);
6860 /* Account for reserved pages */
6861 if (j == 0 && freesize > dma_reserve) {
6862 freesize -= dma_reserve;
6863 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
6864 zone_names[0], dma_reserve);
6867 if (!is_highmem_idx(j))
6868 nr_kernel_pages += freesize;
6869 /* Charge for highmem memmap if there are enough kernel pages */
6870 else if (nr_kernel_pages > memmap_pages * 2)
6871 nr_kernel_pages -= memmap_pages;
6872 nr_all_pages += freesize;
6875 * Set an approximate value for lowmem here, it will be adjusted
6876 * when the bootmem allocator frees pages into the buddy system.
6877 * And all highmem pages will be managed by the buddy system.
6879 zone_init_internals(zone, j, nid, freesize);
6884 set_pageblock_order();
6885 setup_usemap(pgdat, zone, zone_start_pfn, size);
6886 init_currently_empty_zone(zone, zone_start_pfn, size);
6887 memmap_init(size, nid, j, zone_start_pfn);
6891 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6892 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
6894 unsigned long __maybe_unused start = 0;
6895 unsigned long __maybe_unused offset = 0;
6897 /* Skip empty nodes */
6898 if (!pgdat->node_spanned_pages)
6901 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6902 offset = pgdat->node_start_pfn - start;
6903 /* ia64 gets its own node_mem_map, before this, without bootmem */
6904 if (!pgdat->node_mem_map) {
6905 unsigned long size, end;
6909 * The zone's endpoints aren't required to be MAX_ORDER
6910 * aligned but the node_mem_map endpoints must be in order
6911 * for the buddy allocator to function correctly.
6913 end = pgdat_end_pfn(pgdat);
6914 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6915 size = (end - start) * sizeof(struct page);
6916 map = memblock_alloc_node(size, SMP_CACHE_BYTES,
6919 panic("Failed to allocate %ld bytes for node %d memory map\n",
6920 size, pgdat->node_id);
6921 pgdat->node_mem_map = map + offset;
6923 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6924 __func__, pgdat->node_id, (unsigned long)pgdat,
6925 (unsigned long)pgdat->node_mem_map);
6926 #ifndef CONFIG_NEED_MULTIPLE_NODES
6928 * With no DISCONTIG, the global mem_map is just set as node 0's
6930 if (pgdat == NODE_DATA(0)) {
6931 mem_map = NODE_DATA(0)->node_mem_map;
6932 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6933 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6935 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6940 static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
6941 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6943 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6944 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
6946 pgdat->first_deferred_pfn = ULONG_MAX;
6949 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
6952 void __init free_area_init_node(int nid, unsigned long *zones_size,
6953 unsigned long node_start_pfn,
6954 unsigned long *zholes_size)
6956 pg_data_t *pgdat = NODE_DATA(nid);
6957 unsigned long start_pfn = 0;
6958 unsigned long end_pfn = 0;
6960 /* pg_data_t should be reset to zero when it's allocated */
6961 WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
6963 pgdat->node_id = nid;
6964 pgdat->node_start_pfn = node_start_pfn;
6965 pgdat->per_cpu_nodestats = NULL;
6966 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6967 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6968 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6969 (u64)start_pfn << PAGE_SHIFT,
6970 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6972 start_pfn = node_start_pfn;
6974 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6975 zones_size, zholes_size);
6977 alloc_node_mem_map(pgdat);
6978 pgdat_set_deferred_range(pgdat);
6980 free_area_init_core(pgdat);
6983 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
6985 * Initialize all valid struct pages in the range [spfn, epfn) and mark them
6986 * PageReserved(). Return the number of struct pages that were initialized.
6988 static u64 __init init_unavailable_range(unsigned long spfn, unsigned long epfn)
6993 for (pfn = spfn; pfn < epfn; pfn++) {
6994 if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
6995 pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
6996 + pageblock_nr_pages - 1;
7000 * Use a fake node/zone (0) for now. Some of these pages
7001 * (in memblock.reserved but not in memblock.memory) will
7002 * get re-initialized via reserve_bootmem_region() later.
7004 __init_single_page(pfn_to_page(pfn), pfn, 0, 0);
7005 __SetPageReserved(pfn_to_page(pfn));
7013 * Only struct pages that are backed by physical memory are zeroed and
7014 * initialized by going through __init_single_page(). But, there are some
7015 * struct pages which are reserved in memblock allocator and their fields
7016 * may be accessed (for example page_to_pfn() on some configuration accesses
7017 * flags). We must explicitly initialize those struct pages.
7019 * This function also addresses a similar issue where struct pages are left
7020 * uninitialized because the physical address range is not covered by
7021 * memblock.memory or memblock.reserved. That could happen when memblock
7022 * layout is manually configured via memmap=, or when the highest physical
7023 * address (max_pfn) does not end on a section boundary.
7025 static void __init init_unavailable_mem(void)
7027 phys_addr_t start, end;
7029 phys_addr_t next = 0;
7032 * Loop through unavailable ranges not covered by memblock.memory.
7035 for_each_mem_range(i, &memblock.memory, NULL,
7036 NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) {
7038 pgcnt += init_unavailable_range(PFN_DOWN(next),
7044 * Early sections always have a fully populated memmap for the whole
7045 * section - see pfn_valid(). If the last section has holes at the
7046 * end and that section is marked "online", the memmap will be
7047 * considered initialized. Make sure that memmap has a well defined
7050 pgcnt += init_unavailable_range(PFN_DOWN(next),
7051 round_up(max_pfn, PAGES_PER_SECTION));
7054 * Struct pages that do not have backing memory. This could be because
7055 * firmware is using some of this memory, or for some other reasons.
7058 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt);
7061 static inline void __init init_unavailable_mem(void)
7064 #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
7066 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
7068 #if MAX_NUMNODES > 1
7070 * Figure out the number of possible node ids.
7072 void __init setup_nr_node_ids(void)
7074 unsigned int highest;
7076 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
7077 nr_node_ids = highest + 1;
7082 * node_map_pfn_alignment - determine the maximum internode alignment
7084 * This function should be called after node map is populated and sorted.
7085 * It calculates the maximum power of two alignment which can distinguish
7088 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7089 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7090 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7091 * shifted, 1GiB is enough and this function will indicate so.
7093 * This is used to test whether pfn -> nid mapping of the chosen memory
7094 * model has fine enough granularity to avoid incorrect mapping for the
7095 * populated node map.
7097 * Return: the determined alignment in pfn's. 0 if there is no alignment
7098 * requirement (single node).
7100 unsigned long __init node_map_pfn_alignment(void)
7102 unsigned long accl_mask = 0, last_end = 0;
7103 unsigned long start, end, mask;
7104 int last_nid = NUMA_NO_NODE;
7107 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
7108 if (!start || last_nid < 0 || last_nid == nid) {
7115 * Start with a mask granular enough to pin-point to the
7116 * start pfn and tick off bits one-by-one until it becomes
7117 * too coarse to separate the current node from the last.
7119 mask = ~((1 << __ffs(start)) - 1);
7120 while (mask && last_end <= (start & (mask << 1)))
7123 /* accumulate all internode masks */
7127 /* convert mask to number of pages */
7128 return ~accl_mask + 1;
7131 /* Find the lowest pfn for a node */
7132 static unsigned long __init find_min_pfn_for_node(int nid)
7134 unsigned long min_pfn = ULONG_MAX;
7135 unsigned long start_pfn;
7138 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
7139 min_pfn = min(min_pfn, start_pfn);
7141 if (min_pfn == ULONG_MAX) {
7142 pr_warn("Could not find start_pfn for node %d\n", nid);
7150 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7152 * Return: the minimum PFN based on information provided via
7153 * memblock_set_node().
7155 unsigned long __init find_min_pfn_with_active_regions(void)
7157 return find_min_pfn_for_node(MAX_NUMNODES);
7161 * early_calculate_totalpages()
7162 * Sum pages in active regions for movable zone.
7163 * Populate N_MEMORY for calculating usable_nodes.
7165 static unsigned long __init early_calculate_totalpages(void)
7167 unsigned long totalpages = 0;
7168 unsigned long start_pfn, end_pfn;
7171 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7172 unsigned long pages = end_pfn - start_pfn;
7174 totalpages += pages;
7176 node_set_state(nid, N_MEMORY);
7182 * Find the PFN the Movable zone begins in each node. Kernel memory
7183 * is spread evenly between nodes as long as the nodes have enough
7184 * memory. When they don't, some nodes will have more kernelcore than
7187 static void __init find_zone_movable_pfns_for_nodes(void)
7190 unsigned long usable_startpfn;
7191 unsigned long kernelcore_node, kernelcore_remaining;
7192 /* save the state before borrow the nodemask */
7193 nodemask_t saved_node_state = node_states[N_MEMORY];
7194 unsigned long totalpages = early_calculate_totalpages();
7195 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
7196 struct memblock_region *r;
7198 /* Need to find movable_zone earlier when movable_node is specified. */
7199 find_usable_zone_for_movable();
7202 * If movable_node is specified, ignore kernelcore and movablecore
7205 if (movable_node_is_enabled()) {
7206 for_each_memblock(memory, r) {
7207 if (!memblock_is_hotpluggable(r))
7212 usable_startpfn = PFN_DOWN(r->base);
7213 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7214 min(usable_startpfn, zone_movable_pfn[nid]) :
7222 * If kernelcore=mirror is specified, ignore movablecore option
7224 if (mirrored_kernelcore) {
7225 bool mem_below_4gb_not_mirrored = false;
7227 for_each_memblock(memory, r) {
7228 if (memblock_is_mirror(r))
7233 usable_startpfn = memblock_region_memory_base_pfn(r);
7235 if (usable_startpfn < 0x100000) {
7236 mem_below_4gb_not_mirrored = true;
7240 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7241 min(usable_startpfn, zone_movable_pfn[nid]) :
7245 if (mem_below_4gb_not_mirrored)
7246 pr_warn("This configuration results in unmirrored kernel memory.");
7252 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7253 * amount of necessary memory.
7255 if (required_kernelcore_percent)
7256 required_kernelcore = (totalpages * 100 * required_kernelcore_percent) /
7258 if (required_movablecore_percent)
7259 required_movablecore = (totalpages * 100 * required_movablecore_percent) /
7263 * If movablecore= was specified, calculate what size of
7264 * kernelcore that corresponds so that memory usable for
7265 * any allocation type is evenly spread. If both kernelcore
7266 * and movablecore are specified, then the value of kernelcore
7267 * will be used for required_kernelcore if it's greater than
7268 * what movablecore would have allowed.
7270 if (required_movablecore) {
7271 unsigned long corepages;
7274 * Round-up so that ZONE_MOVABLE is at least as large as what
7275 * was requested by the user
7277 required_movablecore =
7278 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
7279 required_movablecore = min(totalpages, required_movablecore);
7280 corepages = totalpages - required_movablecore;
7282 required_kernelcore = max(required_kernelcore, corepages);
7286 * If kernelcore was not specified or kernelcore size is larger
7287 * than totalpages, there is no ZONE_MOVABLE.
7289 if (!required_kernelcore || required_kernelcore >= totalpages)
7292 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7293 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
7296 /* Spread kernelcore memory as evenly as possible throughout nodes */
7297 kernelcore_node = required_kernelcore / usable_nodes;
7298 for_each_node_state(nid, N_MEMORY) {
7299 unsigned long start_pfn, end_pfn;
7302 * Recalculate kernelcore_node if the division per node
7303 * now exceeds what is necessary to satisfy the requested
7304 * amount of memory for the kernel
7306 if (required_kernelcore < kernelcore_node)
7307 kernelcore_node = required_kernelcore / usable_nodes;
7310 * As the map is walked, we track how much memory is usable
7311 * by the kernel using kernelcore_remaining. When it is
7312 * 0, the rest of the node is usable by ZONE_MOVABLE
7314 kernelcore_remaining = kernelcore_node;
7316 /* Go through each range of PFNs within this node */
7317 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
7318 unsigned long size_pages;
7320 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
7321 if (start_pfn >= end_pfn)
7324 /* Account for what is only usable for kernelcore */
7325 if (start_pfn < usable_startpfn) {
7326 unsigned long kernel_pages;
7327 kernel_pages = min(end_pfn, usable_startpfn)
7330 kernelcore_remaining -= min(kernel_pages,
7331 kernelcore_remaining);
7332 required_kernelcore -= min(kernel_pages,
7333 required_kernelcore);
7335 /* Continue if range is now fully accounted */
7336 if (end_pfn <= usable_startpfn) {
7339 * Push zone_movable_pfn to the end so
7340 * that if we have to rebalance
7341 * kernelcore across nodes, we will
7342 * not double account here
7344 zone_movable_pfn[nid] = end_pfn;
7347 start_pfn = usable_startpfn;
7351 * The usable PFN range for ZONE_MOVABLE is from
7352 * start_pfn->end_pfn. Calculate size_pages as the
7353 * number of pages used as kernelcore
7355 size_pages = end_pfn - start_pfn;
7356 if (size_pages > kernelcore_remaining)
7357 size_pages = kernelcore_remaining;
7358 zone_movable_pfn[nid] = start_pfn + size_pages;
7361 * Some kernelcore has been met, update counts and
7362 * break if the kernelcore for this node has been
7365 required_kernelcore -= min(required_kernelcore,
7367 kernelcore_remaining -= size_pages;
7368 if (!kernelcore_remaining)
7374 * If there is still required_kernelcore, we do another pass with one
7375 * less node in the count. This will push zone_movable_pfn[nid] further
7376 * along on the nodes that still have memory until kernelcore is
7380 if (usable_nodes && required_kernelcore > usable_nodes)
7384 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7385 for (nid = 0; nid < MAX_NUMNODES; nid++)
7386 zone_movable_pfn[nid] =
7387 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
7390 /* restore the node_state */
7391 node_states[N_MEMORY] = saved_node_state;
7394 /* Any regular or high memory on that node ? */
7395 static void check_for_memory(pg_data_t *pgdat, int nid)
7397 enum zone_type zone_type;
7399 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
7400 struct zone *zone = &pgdat->node_zones[zone_type];
7401 if (populated_zone(zone)) {
7402 if (IS_ENABLED(CONFIG_HIGHMEM))
7403 node_set_state(nid, N_HIGH_MEMORY);
7404 if (zone_type <= ZONE_NORMAL)
7405 node_set_state(nid, N_NORMAL_MEMORY);
7412 * free_area_init_nodes - Initialise all pg_data_t and zone data
7413 * @max_zone_pfn: an array of max PFNs for each zone
7415 * This will call free_area_init_node() for each active node in the system.
7416 * Using the page ranges provided by memblock_set_node(), the size of each
7417 * zone in each node and their holes is calculated. If the maximum PFN
7418 * between two adjacent zones match, it is assumed that the zone is empty.
7419 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7420 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7421 * starts where the previous one ended. For example, ZONE_DMA32 starts
7422 * at arch_max_dma_pfn.
7424 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
7426 unsigned long start_pfn, end_pfn;
7429 /* Record where the zone boundaries are */
7430 memset(arch_zone_lowest_possible_pfn, 0,
7431 sizeof(arch_zone_lowest_possible_pfn));
7432 memset(arch_zone_highest_possible_pfn, 0,
7433 sizeof(arch_zone_highest_possible_pfn));
7435 start_pfn = find_min_pfn_with_active_regions();
7437 for (i = 0; i < MAX_NR_ZONES; i++) {
7438 if (i == ZONE_MOVABLE)
7441 end_pfn = max(max_zone_pfn[i], start_pfn);
7442 arch_zone_lowest_possible_pfn[i] = start_pfn;
7443 arch_zone_highest_possible_pfn[i] = end_pfn;
7445 start_pfn = end_pfn;
7448 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7449 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
7450 find_zone_movable_pfns_for_nodes();
7452 /* Print out the zone ranges */
7453 pr_info("Zone ranges:\n");
7454 for (i = 0; i < MAX_NR_ZONES; i++) {
7455 if (i == ZONE_MOVABLE)
7457 pr_info(" %-8s ", zone_names[i]);
7458 if (arch_zone_lowest_possible_pfn[i] ==
7459 arch_zone_highest_possible_pfn[i])
7462 pr_cont("[mem %#018Lx-%#018Lx]\n",
7463 (u64)arch_zone_lowest_possible_pfn[i]
7465 ((u64)arch_zone_highest_possible_pfn[i]
7466 << PAGE_SHIFT) - 1);
7469 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7470 pr_info("Movable zone start for each node\n");
7471 for (i = 0; i < MAX_NUMNODES; i++) {
7472 if (zone_movable_pfn[i])
7473 pr_info(" Node %d: %#018Lx\n", i,
7474 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
7478 * Print out the early node map, and initialize the
7479 * subsection-map relative to active online memory ranges to
7480 * enable future "sub-section" extensions of the memory map.
7482 pr_info("Early memory node ranges\n");
7483 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7484 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
7485 (u64)start_pfn << PAGE_SHIFT,
7486 ((u64)end_pfn << PAGE_SHIFT) - 1);
7487 subsection_map_init(start_pfn, end_pfn - start_pfn);
7490 /* Initialise every node */
7491 mminit_verify_pageflags_layout();
7492 setup_nr_node_ids();
7493 init_unavailable_mem();
7494 for_each_online_node(nid) {
7495 pg_data_t *pgdat = NODE_DATA(nid);
7496 free_area_init_node(nid, NULL,
7497 find_min_pfn_for_node(nid), NULL);
7499 /* Any memory on that node */
7500 if (pgdat->node_present_pages)
7501 node_set_state(nid, N_MEMORY);
7502 check_for_memory(pgdat, nid);
7506 static int __init cmdline_parse_core(char *p, unsigned long *core,
7507 unsigned long *percent)
7509 unsigned long long coremem;
7515 /* Value may be a percentage of total memory, otherwise bytes */
7516 coremem = simple_strtoull(p, &endptr, 0);
7517 if (*endptr == '%') {
7518 /* Paranoid check for percent values greater than 100 */
7519 WARN_ON(coremem > 100);
7523 coremem = memparse(p, &p);
7524 /* Paranoid check that UL is enough for the coremem value */
7525 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
7527 *core = coremem >> PAGE_SHIFT;
7534 * kernelcore=size sets the amount of memory for use for allocations that
7535 * cannot be reclaimed or migrated.
7537 static int __init cmdline_parse_kernelcore(char *p)
7539 /* parse kernelcore=mirror */
7540 if (parse_option_str(p, "mirror")) {
7541 mirrored_kernelcore = true;
7545 return cmdline_parse_core(p, &required_kernelcore,
7546 &required_kernelcore_percent);
7550 * movablecore=size sets the amount of memory for use for allocations that
7551 * can be reclaimed or migrated.
7553 static int __init cmdline_parse_movablecore(char *p)
7555 return cmdline_parse_core(p, &required_movablecore,
7556 &required_movablecore_percent);
7559 early_param("kernelcore", cmdline_parse_kernelcore);
7560 early_param("movablecore", cmdline_parse_movablecore);
7562 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
7564 void adjust_managed_page_count(struct page *page, long count)
7566 atomic_long_add(count, &page_zone(page)->managed_pages);
7567 totalram_pages_add(count);
7568 #ifdef CONFIG_HIGHMEM
7569 if (PageHighMem(page))
7570 totalhigh_pages_add(count);
7573 EXPORT_SYMBOL(adjust_managed_page_count);
7575 unsigned long free_reserved_area(void *start, void *end, int poison, const char *s)
7578 unsigned long pages = 0;
7580 start = (void *)PAGE_ALIGN((unsigned long)start);
7581 end = (void *)((unsigned long)end & PAGE_MASK);
7582 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
7583 struct page *page = virt_to_page(pos);
7584 void *direct_map_addr;
7587 * 'direct_map_addr' might be different from 'pos'
7588 * because some architectures' virt_to_page()
7589 * work with aliases. Getting the direct map
7590 * address ensures that we get a _writeable_
7591 * alias for the memset().
7593 direct_map_addr = page_address(page);
7594 if ((unsigned int)poison <= 0xFF)
7595 memset(direct_map_addr, poison, PAGE_SIZE);
7597 free_reserved_page(page);
7601 pr_info("Freeing %s memory: %ldK\n",
7602 s, pages << (PAGE_SHIFT - 10));
7607 #ifdef CONFIG_HIGHMEM
7608 void free_highmem_page(struct page *page)
7610 __free_reserved_page(page);
7611 totalram_pages_inc();
7612 atomic_long_inc(&page_zone(page)->managed_pages);
7613 totalhigh_pages_inc();
7618 void __init mem_init_print_info(const char *str)
7620 unsigned long physpages, codesize, datasize, rosize, bss_size;
7621 unsigned long init_code_size, init_data_size;
7623 physpages = get_num_physpages();
7624 codesize = _etext - _stext;
7625 datasize = _edata - _sdata;
7626 rosize = __end_rodata - __start_rodata;
7627 bss_size = __bss_stop - __bss_start;
7628 init_data_size = __init_end - __init_begin;
7629 init_code_size = _einittext - _sinittext;
7632 * Detect special cases and adjust section sizes accordingly:
7633 * 1) .init.* may be embedded into .data sections
7634 * 2) .init.text.* may be out of [__init_begin, __init_end],
7635 * please refer to arch/tile/kernel/vmlinux.lds.S.
7636 * 3) .rodata.* may be embedded into .text or .data sections.
7638 #define adj_init_size(start, end, size, pos, adj) \
7640 if (start <= pos && pos < end && size > adj) \
7644 adj_init_size(__init_begin, __init_end, init_data_size,
7645 _sinittext, init_code_size);
7646 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
7647 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
7648 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
7649 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
7651 #undef adj_init_size
7653 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7654 #ifdef CONFIG_HIGHMEM
7658 nr_free_pages() << (PAGE_SHIFT - 10),
7659 physpages << (PAGE_SHIFT - 10),
7660 codesize >> 10, datasize >> 10, rosize >> 10,
7661 (init_data_size + init_code_size) >> 10, bss_size >> 10,
7662 (physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10),
7663 totalcma_pages << (PAGE_SHIFT - 10),
7664 #ifdef CONFIG_HIGHMEM
7665 totalhigh_pages() << (PAGE_SHIFT - 10),
7667 str ? ", " : "", str ? str : "");
7671 * set_dma_reserve - set the specified number of pages reserved in the first zone
7672 * @new_dma_reserve: The number of pages to mark reserved
7674 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7675 * In the DMA zone, a significant percentage may be consumed by kernel image
7676 * and other unfreeable allocations which can skew the watermarks badly. This
7677 * function may optionally be used to account for unfreeable pages in the
7678 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7679 * smaller per-cpu batchsize.
7681 void __init set_dma_reserve(unsigned long new_dma_reserve)
7683 dma_reserve = new_dma_reserve;
7686 void __init free_area_init(unsigned long *zones_size)
7688 init_unavailable_mem();
7689 free_area_init_node(0, zones_size,
7690 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
7693 static int page_alloc_cpu_dead(unsigned int cpu)
7696 lru_add_drain_cpu(cpu);
7700 * Spill the event counters of the dead processor
7701 * into the current processors event counters.
7702 * This artificially elevates the count of the current
7705 vm_events_fold_cpu(cpu);
7708 * Zero the differential counters of the dead processor
7709 * so that the vm statistics are consistent.
7711 * This is only okay since the processor is dead and cannot
7712 * race with what we are doing.
7714 cpu_vm_stats_fold(cpu);
7719 int hashdist = HASHDIST_DEFAULT;
7721 static int __init set_hashdist(char *str)
7725 hashdist = simple_strtoul(str, &str, 0);
7728 __setup("hashdist=", set_hashdist);
7731 void __init page_alloc_init(void)
7736 if (num_node_state(N_MEMORY) == 1)
7740 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD,
7741 "mm/page_alloc:dead", NULL,
7742 page_alloc_cpu_dead);
7747 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7748 * or min_free_kbytes changes.
7750 static void calculate_totalreserve_pages(void)
7752 struct pglist_data *pgdat;
7753 unsigned long reserve_pages = 0;
7754 enum zone_type i, j;
7756 for_each_online_pgdat(pgdat) {
7758 pgdat->totalreserve_pages = 0;
7760 for (i = 0; i < MAX_NR_ZONES; i++) {
7761 struct zone *zone = pgdat->node_zones + i;
7763 unsigned long managed_pages = zone_managed_pages(zone);
7765 /* Find valid and maximum lowmem_reserve in the zone */
7766 for (j = i; j < MAX_NR_ZONES; j++) {
7767 if (zone->lowmem_reserve[j] > max)
7768 max = zone->lowmem_reserve[j];
7771 /* we treat the high watermark as reserved pages. */
7772 max += high_wmark_pages(zone);
7774 if (max > managed_pages)
7775 max = managed_pages;
7777 pgdat->totalreserve_pages += max;
7779 reserve_pages += max;
7782 totalreserve_pages = reserve_pages;
7786 * setup_per_zone_lowmem_reserve - called whenever
7787 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7788 * has a correct pages reserved value, so an adequate number of
7789 * pages are left in the zone after a successful __alloc_pages().
7791 static void setup_per_zone_lowmem_reserve(void)
7793 struct pglist_data *pgdat;
7794 enum zone_type j, idx;
7796 for_each_online_pgdat(pgdat) {
7797 for (j = 0; j < MAX_NR_ZONES; j++) {
7798 struct zone *zone = pgdat->node_zones + j;
7799 unsigned long managed_pages = zone_managed_pages(zone);
7801 zone->lowmem_reserve[j] = 0;
7805 struct zone *lower_zone;
7808 lower_zone = pgdat->node_zones + idx;
7810 if (sysctl_lowmem_reserve_ratio[idx] < 1) {
7811 sysctl_lowmem_reserve_ratio[idx] = 0;
7812 lower_zone->lowmem_reserve[j] = 0;
7814 lower_zone->lowmem_reserve[j] =
7815 managed_pages / sysctl_lowmem_reserve_ratio[idx];
7817 managed_pages += zone_managed_pages(lower_zone);
7822 /* update totalreserve_pages */
7823 calculate_totalreserve_pages();
7826 static void __setup_per_zone_wmarks(void)
7828 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
7829 unsigned long lowmem_pages = 0;
7831 unsigned long flags;
7833 /* Calculate total number of !ZONE_HIGHMEM pages */
7834 for_each_zone(zone) {
7835 if (!is_highmem(zone))
7836 lowmem_pages += zone_managed_pages(zone);
7839 for_each_zone(zone) {
7842 spin_lock_irqsave(&zone->lock, flags);
7843 tmp = (u64)pages_min * zone_managed_pages(zone);
7844 do_div(tmp, lowmem_pages);
7845 if (is_highmem(zone)) {
7847 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7848 * need highmem pages, so cap pages_min to a small
7851 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7852 * deltas control async page reclaim, and so should
7853 * not be capped for highmem.
7855 unsigned long min_pages;
7857 min_pages = zone_managed_pages(zone) / 1024;
7858 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
7859 zone->_watermark[WMARK_MIN] = min_pages;
7862 * If it's a lowmem zone, reserve a number of pages
7863 * proportionate to the zone's size.
7865 zone->_watermark[WMARK_MIN] = tmp;
7869 * Set the kswapd watermarks distance according to the
7870 * scale factor in proportion to available memory, but
7871 * ensure a minimum size on small systems.
7873 tmp = max_t(u64, tmp >> 2,
7874 mult_frac(zone_managed_pages(zone),
7875 watermark_scale_factor, 10000));
7877 zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
7878 zone->_watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
7879 zone->watermark_boost = 0;
7881 spin_unlock_irqrestore(&zone->lock, flags);
7884 /* update totalreserve_pages */
7885 calculate_totalreserve_pages();
7889 * setup_per_zone_wmarks - called when min_free_kbytes changes
7890 * or when memory is hot-{added|removed}
7892 * Ensures that the watermark[min,low,high] values for each zone are set
7893 * correctly with respect to min_free_kbytes.
7895 void setup_per_zone_wmarks(void)
7897 static DEFINE_SPINLOCK(lock);
7900 __setup_per_zone_wmarks();
7905 * Initialise min_free_kbytes.
7907 * For small machines we want it small (128k min). For large machines
7908 * we want it large (64MB max). But it is not linear, because network
7909 * bandwidth does not increase linearly with machine size. We use
7911 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7912 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7928 int __meminit init_per_zone_wmark_min(void)
7930 unsigned long lowmem_kbytes;
7931 int new_min_free_kbytes;
7933 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
7934 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
7936 if (new_min_free_kbytes > user_min_free_kbytes) {
7937 min_free_kbytes = new_min_free_kbytes;
7938 if (min_free_kbytes < 128)
7939 min_free_kbytes = 128;
7940 if (min_free_kbytes > 262144)
7941 min_free_kbytes = 262144;
7943 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7944 new_min_free_kbytes, user_min_free_kbytes);
7946 setup_per_zone_wmarks();
7947 refresh_zone_stat_thresholds();
7948 setup_per_zone_lowmem_reserve();
7951 setup_min_unmapped_ratio();
7952 setup_min_slab_ratio();
7957 core_initcall(init_per_zone_wmark_min)
7960 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7961 * that we can call two helper functions whenever min_free_kbytes
7964 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
7965 void __user *buffer, size_t *length, loff_t *ppos)
7969 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7974 user_min_free_kbytes = min_free_kbytes;
7975 setup_per_zone_wmarks();
7980 int watermark_boost_factor_sysctl_handler(struct ctl_table *table, int write,
7981 void __user *buffer, size_t *length, loff_t *ppos)
7985 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7992 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
7993 void __user *buffer, size_t *length, loff_t *ppos)
7997 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8002 setup_per_zone_wmarks();
8008 static void setup_min_unmapped_ratio(void)
8013 for_each_online_pgdat(pgdat)
8014 pgdat->min_unmapped_pages = 0;
8017 zone->zone_pgdat->min_unmapped_pages += (zone_managed_pages(zone) *
8018 sysctl_min_unmapped_ratio) / 100;
8022 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
8023 void __user *buffer, size_t *length, loff_t *ppos)
8027 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8031 setup_min_unmapped_ratio();
8036 static void setup_min_slab_ratio(void)
8041 for_each_online_pgdat(pgdat)
8042 pgdat->min_slab_pages = 0;
8045 zone->zone_pgdat->min_slab_pages += (zone_managed_pages(zone) *
8046 sysctl_min_slab_ratio) / 100;
8049 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
8050 void __user *buffer, size_t *length, loff_t *ppos)
8054 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8058 setup_min_slab_ratio();
8065 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8066 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8067 * whenever sysctl_lowmem_reserve_ratio changes.
8069 * The reserve ratio obviously has absolutely no relation with the
8070 * minimum watermarks. The lowmem reserve ratio can only make sense
8071 * if in function of the boot time zone sizes.
8073 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
8074 void __user *buffer, size_t *length, loff_t *ppos)
8076 proc_dointvec_minmax(table, write, buffer, length, ppos);
8077 setup_per_zone_lowmem_reserve();
8081 static void __zone_pcp_update(struct zone *zone)
8085 for_each_possible_cpu(cpu)
8086 pageset_set_high_and_batch(zone,
8087 per_cpu_ptr(zone->pageset, cpu));
8091 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8092 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8093 * pagelist can have before it gets flushed back to buddy allocator.
8095 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
8096 void __user *buffer, size_t *length, loff_t *ppos)
8099 int old_percpu_pagelist_fraction;
8102 mutex_lock(&pcp_batch_high_lock);
8103 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
8105 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
8106 if (!write || ret < 0)
8109 /* Sanity checking to avoid pcp imbalance */
8110 if (percpu_pagelist_fraction &&
8111 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
8112 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
8118 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
8121 for_each_populated_zone(zone)
8122 __zone_pcp_update(zone);
8124 mutex_unlock(&pcp_batch_high_lock);
8128 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8130 * Returns the number of pages that arch has reserved but
8131 * is not known to alloc_large_system_hash().
8133 static unsigned long __init arch_reserved_kernel_pages(void)
8140 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8141 * machines. As memory size is increased the scale is also increased but at
8142 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8143 * quadruples the scale is increased by one, which means the size of hash table
8144 * only doubles, instead of quadrupling as well.
8145 * Because 32-bit systems cannot have large physical memory, where this scaling
8146 * makes sense, it is disabled on such platforms.
8148 #if __BITS_PER_LONG > 32
8149 #define ADAPT_SCALE_BASE (64ul << 30)
8150 #define ADAPT_SCALE_SHIFT 2
8151 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8155 * allocate a large system hash table from bootmem
8156 * - it is assumed that the hash table must contain an exact power-of-2
8157 * quantity of entries
8158 * - limit is the number of hash buckets, not the total allocation size
8160 void *__init alloc_large_system_hash(const char *tablename,
8161 unsigned long bucketsize,
8162 unsigned long numentries,
8165 unsigned int *_hash_shift,
8166 unsigned int *_hash_mask,
8167 unsigned long low_limit,
8168 unsigned long high_limit)
8170 unsigned long long max = high_limit;
8171 unsigned long log2qty, size;
8176 /* allow the kernel cmdline to have a say */
8178 /* round applicable memory size up to nearest megabyte */
8179 numentries = nr_kernel_pages;
8180 numentries -= arch_reserved_kernel_pages();
8182 /* It isn't necessary when PAGE_SIZE >= 1MB */
8183 if (PAGE_SHIFT < 20)
8184 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
8186 #if __BITS_PER_LONG > 32
8188 unsigned long adapt;
8190 for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries;
8191 adapt <<= ADAPT_SCALE_SHIFT)
8196 /* limit to 1 bucket per 2^scale bytes of low memory */
8197 if (scale > PAGE_SHIFT)
8198 numentries >>= (scale - PAGE_SHIFT);
8200 numentries <<= (PAGE_SHIFT - scale);
8202 /* Make sure we've got at least a 0-order allocation.. */
8203 if (unlikely(flags & HASH_SMALL)) {
8204 /* Makes no sense without HASH_EARLY */
8205 WARN_ON(!(flags & HASH_EARLY));
8206 if (!(numentries >> *_hash_shift)) {
8207 numentries = 1UL << *_hash_shift;
8208 BUG_ON(!numentries);
8210 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
8211 numentries = PAGE_SIZE / bucketsize;
8213 numentries = roundup_pow_of_two(numentries);
8215 /* limit allocation size to 1/16 total memory by default */
8217 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
8218 do_div(max, bucketsize);
8220 max = min(max, 0x80000000ULL);
8222 if (numentries < low_limit)
8223 numentries = low_limit;
8224 if (numentries > max)
8227 log2qty = ilog2(numentries);
8229 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
8232 size = bucketsize << log2qty;
8233 if (flags & HASH_EARLY) {
8234 if (flags & HASH_ZERO)
8235 table = memblock_alloc(size, SMP_CACHE_BYTES);
8237 table = memblock_alloc_raw(size,
8239 } else if (get_order(size) >= MAX_ORDER || hashdist) {
8240 table = __vmalloc(size, gfp_flags, PAGE_KERNEL);
8244 * If bucketsize is not a power-of-two, we may free
8245 * some pages at the end of hash table which
8246 * alloc_pages_exact() automatically does
8248 table = alloc_pages_exact(size, gfp_flags);
8249 kmemleak_alloc(table, size, 1, gfp_flags);
8251 } while (!table && size > PAGE_SIZE && --log2qty);
8254 panic("Failed to allocate %s hash table\n", tablename);
8256 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8257 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
8258 virt ? "vmalloc" : "linear");
8261 *_hash_shift = log2qty;
8263 *_hash_mask = (1 << log2qty) - 1;
8269 * This function checks whether pageblock includes unmovable pages or not.
8271 * PageLRU check without isolation or lru_lock could race so that
8272 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8273 * check without lock_page also may miss some movable non-lru pages at
8274 * race condition. So you can't expect this function should be exact.
8276 * Returns a page without holding a reference. If the caller wants to
8277 * dereference that page (e.g., dumping), it has to make sure that that it
8278 * cannot get removed (e.g., via memory unplug) concurrently.
8281 struct page *has_unmovable_pages(struct zone *zone, struct page *page,
8282 int migratetype, int flags)
8284 unsigned long iter = 0;
8285 unsigned long pfn = page_to_pfn(page);
8288 * TODO we could make this much more efficient by not checking every
8289 * page in the range if we know all of them are in MOVABLE_ZONE and
8290 * that the movable zone guarantees that pages are migratable but
8291 * the later is not the case right now unfortunatelly. E.g. movablecore
8292 * can still lead to having bootmem allocations in zone_movable.
8295 if (is_migrate_cma_page(page)) {
8297 * CMA allocations (alloc_contig_range) really need to mark
8298 * isolate CMA pageblocks even when they are not movable in fact
8299 * so consider them movable here.
8301 if (is_migrate_cma(migratetype))
8307 for (; iter < pageblock_nr_pages; iter++) {
8308 if (!pfn_valid_within(pfn + iter))
8311 page = pfn_to_page(pfn + iter);
8313 if (PageReserved(page))
8317 * If the zone is movable and we have ruled out all reserved
8318 * pages then it should be reasonably safe to assume the rest
8321 if (zone_idx(zone) == ZONE_MOVABLE)
8325 * Hugepages are not in LRU lists, but they're movable.
8326 * THPs are on the LRU, but need to be counted as #small pages.
8327 * We need not scan over tail pages because we don't
8328 * handle each tail page individually in migration.
8330 if (PageHuge(page) || PageTransCompound(page)) {
8331 struct page *head = compound_head(page);
8332 unsigned int skip_pages;
8334 if (PageHuge(page)) {
8335 if (!hugepage_migration_supported(page_hstate(head)))
8337 } else if (!PageLRU(head) && !__PageMovable(head)) {
8341 skip_pages = compound_nr(head) - (page - head);
8342 iter += skip_pages - 1;
8347 * We can't use page_count without pin a page
8348 * because another CPU can free compound page.
8349 * This check already skips compound tails of THP
8350 * because their page->_refcount is zero at all time.
8352 if (!page_ref_count(page)) {
8353 if (PageBuddy(page))
8354 iter += (1 << page_order(page)) - 1;
8359 * The HWPoisoned page may be not in buddy system, and
8360 * page_count() is not 0.
8362 if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
8365 if (__PageMovable(page) || PageLRU(page))
8369 * If there are RECLAIMABLE pages, we need to check
8370 * it. But now, memory offline itself doesn't call
8371 * shrink_node_slabs() and it still to be fixed.
8374 * If the page is not RAM, page_count()should be 0.
8375 * we don't need more check. This is an _used_ not-movable page.
8377 * The problematic thing here is PG_reserved pages. PG_reserved
8378 * is set to both of a memory hole page and a _used_ kernel
8386 #ifdef CONFIG_CONTIG_ALLOC
8387 static unsigned long pfn_max_align_down(unsigned long pfn)
8389 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
8390 pageblock_nr_pages) - 1);
8393 static unsigned long pfn_max_align_up(unsigned long pfn)
8395 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
8396 pageblock_nr_pages));
8399 /* [start, end) must belong to a single zone. */
8400 static int __alloc_contig_migrate_range(struct compact_control *cc,
8401 unsigned long start, unsigned long end)
8403 /* This function is based on compact_zone() from compaction.c. */
8404 unsigned long nr_reclaimed;
8405 unsigned long pfn = start;
8406 unsigned int tries = 0;
8411 while (pfn < end || !list_empty(&cc->migratepages)) {
8412 if (fatal_signal_pending(current)) {
8417 if (list_empty(&cc->migratepages)) {
8418 cc->nr_migratepages = 0;
8419 pfn = isolate_migratepages_range(cc, pfn, end);
8425 } else if (++tries == 5) {
8426 ret = ret < 0 ? ret : -EBUSY;
8430 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
8432 cc->nr_migratepages -= nr_reclaimed;
8434 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
8435 NULL, 0, cc->mode, MR_CONTIG_RANGE);
8438 putback_movable_pages(&cc->migratepages);
8445 * alloc_contig_range() -- tries to allocate given range of pages
8446 * @start: start PFN to allocate
8447 * @end: one-past-the-last PFN to allocate
8448 * @migratetype: migratetype of the underlaying pageblocks (either
8449 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8450 * in range must have the same migratetype and it must
8451 * be either of the two.
8452 * @gfp_mask: GFP mask to use during compaction
8454 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8455 * aligned. The PFN range must belong to a single zone.
8457 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8458 * pageblocks in the range. Once isolated, the pageblocks should not
8459 * be modified by others.
8461 * Return: zero on success or negative error code. On success all
8462 * pages which PFN is in [start, end) are allocated for the caller and
8463 * need to be freed with free_contig_range().
8465 int alloc_contig_range(unsigned long start, unsigned long end,
8466 unsigned migratetype, gfp_t gfp_mask)
8468 unsigned long outer_start, outer_end;
8472 struct compact_control cc = {
8473 .nr_migratepages = 0,
8475 .zone = page_zone(pfn_to_page(start)),
8476 .mode = MIGRATE_SYNC,
8477 .ignore_skip_hint = true,
8478 .no_set_skip_hint = true,
8479 .gfp_mask = current_gfp_context(gfp_mask),
8480 .alloc_contig = true,
8482 INIT_LIST_HEAD(&cc.migratepages);
8485 * What we do here is we mark all pageblocks in range as
8486 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8487 * have different sizes, and due to the way page allocator
8488 * work, we align the range to biggest of the two pages so
8489 * that page allocator won't try to merge buddies from
8490 * different pageblocks and change MIGRATE_ISOLATE to some
8491 * other migration type.
8493 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8494 * migrate the pages from an unaligned range (ie. pages that
8495 * we are interested in). This will put all the pages in
8496 * range back to page allocator as MIGRATE_ISOLATE.
8498 * When this is done, we take the pages in range from page
8499 * allocator removing them from the buddy system. This way
8500 * page allocator will never consider using them.
8502 * This lets us mark the pageblocks back as
8503 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8504 * aligned range but not in the unaligned, original range are
8505 * put back to page allocator so that buddy can use them.
8508 ret = start_isolate_page_range(pfn_max_align_down(start),
8509 pfn_max_align_up(end), migratetype, 0);
8514 * In case of -EBUSY, we'd like to know which page causes problem.
8515 * So, just fall through. test_pages_isolated() has a tracepoint
8516 * which will report the busy page.
8518 * It is possible that busy pages could become available before
8519 * the call to test_pages_isolated, and the range will actually be
8520 * allocated. So, if we fall through be sure to clear ret so that
8521 * -EBUSY is not accidentally used or returned to caller.
8523 ret = __alloc_contig_migrate_range(&cc, start, end);
8524 if (ret && ret != -EBUSY)
8529 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8530 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8531 * more, all pages in [start, end) are free in page allocator.
8532 * What we are going to do is to allocate all pages from
8533 * [start, end) (that is remove them from page allocator).
8535 * The only problem is that pages at the beginning and at the
8536 * end of interesting range may be not aligned with pages that
8537 * page allocator holds, ie. they can be part of higher order
8538 * pages. Because of this, we reserve the bigger range and
8539 * once this is done free the pages we are not interested in.
8541 * We don't have to hold zone->lock here because the pages are
8542 * isolated thus they won't get removed from buddy.
8545 lru_add_drain_all();
8548 outer_start = start;
8549 while (!PageBuddy(pfn_to_page(outer_start))) {
8550 if (++order >= MAX_ORDER) {
8551 outer_start = start;
8554 outer_start &= ~0UL << order;
8557 if (outer_start != start) {
8558 order = page_order(pfn_to_page(outer_start));
8561 * outer_start page could be small order buddy page and
8562 * it doesn't include start page. Adjust outer_start
8563 * in this case to report failed page properly
8564 * on tracepoint in test_pages_isolated()
8566 if (outer_start + (1UL << order) <= start)
8567 outer_start = start;
8570 /* Make sure the range is really isolated. */
8571 if (test_pages_isolated(outer_start, end, 0)) {
8572 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8573 __func__, outer_start, end);
8578 /* Grab isolated pages from freelists. */
8579 outer_end = isolate_freepages_range(&cc, outer_start, end);
8585 /* Free head and tail (if any) */
8586 if (start != outer_start)
8587 free_contig_range(outer_start, start - outer_start);
8588 if (end != outer_end)
8589 free_contig_range(end, outer_end - end);
8592 undo_isolate_page_range(pfn_max_align_down(start),
8593 pfn_max_align_up(end), migratetype);
8597 static int __alloc_contig_pages(unsigned long start_pfn,
8598 unsigned long nr_pages, gfp_t gfp_mask)
8600 unsigned long end_pfn = start_pfn + nr_pages;
8602 return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
8606 static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
8607 unsigned long nr_pages)
8609 unsigned long i, end_pfn = start_pfn + nr_pages;
8612 for (i = start_pfn; i < end_pfn; i++) {
8613 page = pfn_to_online_page(i);
8617 if (page_zone(page) != z)
8620 if (PageReserved(page))
8623 if (page_count(page) > 0)
8632 static bool zone_spans_last_pfn(const struct zone *zone,
8633 unsigned long start_pfn, unsigned long nr_pages)
8635 unsigned long last_pfn = start_pfn + nr_pages - 1;
8637 return zone_spans_pfn(zone, last_pfn);
8641 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8642 * @nr_pages: Number of contiguous pages to allocate
8643 * @gfp_mask: GFP mask to limit search and used during compaction
8645 * @nodemask: Mask for other possible nodes
8647 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8648 * on an applicable zonelist to find a contiguous pfn range which can then be
8649 * tried for allocation with alloc_contig_range(). This routine is intended
8650 * for allocation requests which can not be fulfilled with the buddy allocator.
8652 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8653 * power of two then the alignment is guaranteed to be to the given nr_pages
8654 * (e.g. 1GB request would be aligned to 1GB).
8656 * Allocated pages can be freed with free_contig_range() or by manually calling
8657 * __free_page() on each allocated page.
8659 * Return: pointer to contiguous pages on success, or NULL if not successful.
8661 struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
8662 int nid, nodemask_t *nodemask)
8664 unsigned long ret, pfn, flags;
8665 struct zonelist *zonelist;
8669 zonelist = node_zonelist(nid, gfp_mask);
8670 for_each_zone_zonelist_nodemask(zone, z, zonelist,
8671 gfp_zone(gfp_mask), nodemask) {
8672 spin_lock_irqsave(&zone->lock, flags);
8674 pfn = ALIGN(zone->zone_start_pfn, nr_pages);
8675 while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
8676 if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
8678 * We release the zone lock here because
8679 * alloc_contig_range() will also lock the zone
8680 * at some point. If there's an allocation
8681 * spinning on this lock, it may win the race
8682 * and cause alloc_contig_range() to fail...
8684 spin_unlock_irqrestore(&zone->lock, flags);
8685 ret = __alloc_contig_pages(pfn, nr_pages,
8688 return pfn_to_page(pfn);
8689 spin_lock_irqsave(&zone->lock, flags);
8693 spin_unlock_irqrestore(&zone->lock, flags);
8697 #endif /* CONFIG_CONTIG_ALLOC */
8699 void free_contig_range(unsigned long pfn, unsigned int nr_pages)
8701 unsigned int count = 0;
8703 for (; nr_pages--; pfn++) {
8704 struct page *page = pfn_to_page(pfn);
8706 count += page_count(page) != 1;
8709 WARN(count != 0, "%d pages are still in use!\n", count);
8713 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8714 * page high values need to be recalulated.
8716 void __meminit zone_pcp_update(struct zone *zone)
8718 mutex_lock(&pcp_batch_high_lock);
8719 __zone_pcp_update(zone);
8720 mutex_unlock(&pcp_batch_high_lock);
8723 void zone_pcp_reset(struct zone *zone)
8725 unsigned long flags;
8727 struct per_cpu_pageset *pset;
8729 /* avoid races with drain_pages() */
8730 local_irq_save(flags);
8731 if (zone->pageset != &boot_pageset) {
8732 for_each_online_cpu(cpu) {
8733 pset = per_cpu_ptr(zone->pageset, cpu);
8734 drain_zonestat(zone, pset);
8736 free_percpu(zone->pageset);
8737 zone->pageset = &boot_pageset;
8739 local_irq_restore(flags);
8742 #ifdef CONFIG_MEMORY_HOTREMOVE
8744 * All pages in the range must be in a single zone and isolated
8745 * before calling this.
8748 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
8754 unsigned long flags;
8755 unsigned long offlined_pages = 0;
8757 /* find the first valid pfn */
8758 for (pfn = start_pfn; pfn < end_pfn; pfn++)
8762 return offlined_pages;
8764 offline_mem_sections(pfn, end_pfn);
8765 zone = page_zone(pfn_to_page(pfn));
8766 spin_lock_irqsave(&zone->lock, flags);
8768 while (pfn < end_pfn) {
8769 if (!pfn_valid(pfn)) {
8773 page = pfn_to_page(pfn);
8775 * The HWPoisoned page may be not in buddy system, and
8776 * page_count() is not 0.
8778 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
8784 BUG_ON(page_count(page));
8785 BUG_ON(!PageBuddy(page));
8786 order = page_order(page);
8787 offlined_pages += 1 << order;
8788 del_page_from_free_list(page, zone, order);
8789 pfn += (1 << order);
8791 spin_unlock_irqrestore(&zone->lock, flags);
8793 return offlined_pages;
8797 bool is_free_buddy_page(struct page *page)
8799 struct zone *zone = page_zone(page);
8800 unsigned long pfn = page_to_pfn(page);
8801 unsigned long flags;
8804 spin_lock_irqsave(&zone->lock, flags);
8805 for (order = 0; order < MAX_ORDER; order++) {
8806 struct page *page_head = page - (pfn & ((1 << order) - 1));
8808 if (PageBuddy(page_head) && page_order(page_head) >= order)
8811 spin_unlock_irqrestore(&zone->lock, flags);
8813 return order < MAX_ORDER;
8816 #ifdef CONFIG_MEMORY_FAILURE
8818 * Set PG_hwpoison flag if a given page is confirmed to be a free page. This
8819 * test is performed under the zone lock to prevent a race against page
8822 bool set_hwpoison_free_buddy_page(struct page *page)
8824 struct zone *zone = page_zone(page);
8825 unsigned long pfn = page_to_pfn(page);
8826 unsigned long flags;
8828 bool hwpoisoned = false;
8830 spin_lock_irqsave(&zone->lock, flags);
8831 for (order = 0; order < MAX_ORDER; order++) {
8832 struct page *page_head = page - (pfn & ((1 << order) - 1));
8834 if (PageBuddy(page_head) && page_order(page_head) >= order) {
8835 if (!TestSetPageHWPoison(page))
8840 spin_unlock_irqrestore(&zone->lock, flags);