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/mmu_notifier.h>
61 #include <linux/migrate.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/sched/mm.h>
65 #include <linux/page_owner.h>
66 #include <linux/kthread.h>
67 #include <linux/memcontrol.h>
68 #include <linux/ftrace.h>
69 #include <linux/lockdep.h>
70 #include <linux/nmi.h>
71 #include <linux/psi.h>
72 #include <linux/padata.h>
73 #include <linux/khugepaged.h>
74 #include <linux/buffer_head.h>
75 #include <asm/sections.h>
76 #include <asm/tlbflush.h>
77 #include <asm/div64.h>
80 #include "page_reporting.h"
82 /* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
83 typedef int __bitwise fpi_t;
85 /* No special request */
86 #define FPI_NONE ((__force fpi_t)0)
89 * Skip free page reporting notification for the (possibly merged) page.
90 * This does not hinder free page reporting from grabbing the page,
91 * reporting it and marking it "reported" - it only skips notifying
92 * the free page reporting infrastructure about a newly freed page. For
93 * example, used when temporarily pulling a page from a freelist and
94 * putting it back unmodified.
96 #define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0))
99 * Place the (possibly merged) page to the tail of the freelist. Will ignore
100 * page shuffling (relevant code - e.g., memory onlining - is expected to
101 * shuffle the whole zone).
103 * Note: No code should rely on this flag for correctness - it's purely
104 * to allow for optimizations when handing back either fresh pages
105 * (memory onlining) or untouched pages (page isolation, free page
108 #define FPI_TO_TAIL ((__force fpi_t)BIT(1))
111 * Don't poison memory with KASAN (only for the tag-based modes).
112 * During boot, all non-reserved memblock memory is exposed to page_alloc.
113 * Poisoning all that memory lengthens boot time, especially on systems with
114 * large amount of RAM. This flag is used to skip that poisoning.
115 * This is only done for the tag-based KASAN modes, as those are able to
116 * detect memory corruptions with the memory tags assigned by default.
117 * All memory allocated normally after boot gets poisoned as usual.
119 #define FPI_SKIP_KASAN_POISON ((__force fpi_t)BIT(2))
121 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
122 static DEFINE_MUTEX(pcp_batch_high_lock);
123 #define MIN_PERCPU_PAGELIST_HIGH_FRACTION (8)
128 static DEFINE_PER_CPU(struct pagesets, pagesets) = {
129 .lock = INIT_LOCAL_LOCK(lock),
132 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
133 DEFINE_PER_CPU(int, numa_node);
134 EXPORT_PER_CPU_SYMBOL(numa_node);
137 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
139 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
141 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
142 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
143 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
144 * defined in <linux/topology.h>.
146 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
147 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
150 /* work_structs for global per-cpu drains */
153 struct work_struct work;
155 static DEFINE_MUTEX(pcpu_drain_mutex);
156 static DEFINE_PER_CPU(struct pcpu_drain, pcpu_drain);
158 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
159 volatile unsigned long latent_entropy __latent_entropy;
160 EXPORT_SYMBOL(latent_entropy);
164 * Array of node states.
166 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
167 [N_POSSIBLE] = NODE_MASK_ALL,
168 [N_ONLINE] = { { [0] = 1UL } },
170 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
171 #ifdef CONFIG_HIGHMEM
172 [N_HIGH_MEMORY] = { { [0] = 1UL } },
174 [N_MEMORY] = { { [0] = 1UL } },
175 [N_CPU] = { { [0] = 1UL } },
178 EXPORT_SYMBOL(node_states);
180 atomic_long_t _totalram_pages __read_mostly;
181 EXPORT_SYMBOL(_totalram_pages);
182 unsigned long totalreserve_pages __read_mostly;
183 unsigned long totalcma_pages __read_mostly;
185 int percpu_pagelist_high_fraction;
186 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
187 DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc);
188 EXPORT_SYMBOL(init_on_alloc);
190 DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
191 EXPORT_SYMBOL(init_on_free);
193 static bool _init_on_alloc_enabled_early __read_mostly
194 = IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON);
195 static int __init early_init_on_alloc(char *buf)
198 return kstrtobool(buf, &_init_on_alloc_enabled_early);
200 early_param("init_on_alloc", early_init_on_alloc);
202 static bool _init_on_free_enabled_early __read_mostly
203 = IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON);
204 static int __init early_init_on_free(char *buf)
206 return kstrtobool(buf, &_init_on_free_enabled_early);
208 early_param("init_on_free", early_init_on_free);
211 * A cached value of the page's pageblock's migratetype, used when the page is
212 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
213 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
214 * Also the migratetype set in the page does not necessarily match the pcplist
215 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
216 * other index - this ensures that it will be put on the correct CMA freelist.
218 static inline int get_pcppage_migratetype(struct page *page)
223 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
225 page->index = migratetype;
228 #ifdef CONFIG_PM_SLEEP
230 * The following functions are used by the suspend/hibernate code to temporarily
231 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
232 * while devices are suspended. To avoid races with the suspend/hibernate code,
233 * they should always be called with system_transition_mutex held
234 * (gfp_allowed_mask also should only be modified with system_transition_mutex
235 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
236 * with that modification).
239 static gfp_t saved_gfp_mask;
241 void pm_restore_gfp_mask(void)
243 WARN_ON(!mutex_is_locked(&system_transition_mutex));
244 if (saved_gfp_mask) {
245 gfp_allowed_mask = saved_gfp_mask;
250 void pm_restrict_gfp_mask(void)
252 WARN_ON(!mutex_is_locked(&system_transition_mutex));
253 WARN_ON(saved_gfp_mask);
254 saved_gfp_mask = gfp_allowed_mask;
255 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
258 bool pm_suspended_storage(void)
260 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
264 #endif /* CONFIG_PM_SLEEP */
266 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
267 unsigned int pageblock_order __read_mostly;
270 static void __free_pages_ok(struct page *page, unsigned int order,
274 * results with 256, 32 in the lowmem_reserve sysctl:
275 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
276 * 1G machine -> (16M dma, 784M normal, 224M high)
277 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
278 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
279 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
281 * TBD: should special case ZONE_DMA32 machines here - in those we normally
282 * don't need any ZONE_NORMAL reservation
284 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
285 #ifdef CONFIG_ZONE_DMA
288 #ifdef CONFIG_ZONE_DMA32
292 #ifdef CONFIG_HIGHMEM
298 static char * const zone_names[MAX_NR_ZONES] = {
299 #ifdef CONFIG_ZONE_DMA
302 #ifdef CONFIG_ZONE_DMA32
306 #ifdef CONFIG_HIGHMEM
310 #ifdef CONFIG_ZONE_DEVICE
315 const char * const migratetype_names[MIGRATE_TYPES] = {
323 #ifdef CONFIG_MEMORY_ISOLATION
328 compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {
329 [NULL_COMPOUND_DTOR] = NULL,
330 [COMPOUND_PAGE_DTOR] = free_compound_page,
331 #ifdef CONFIG_HUGETLB_PAGE
332 [HUGETLB_PAGE_DTOR] = free_huge_page,
334 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
335 [TRANSHUGE_PAGE_DTOR] = free_transhuge_page,
339 int min_free_kbytes = 1024;
340 int user_min_free_kbytes = -1;
341 int watermark_boost_factor __read_mostly = 15000;
342 int watermark_scale_factor = 10;
344 static unsigned long nr_kernel_pages __initdata;
345 static unsigned long nr_all_pages __initdata;
346 static unsigned long dma_reserve __initdata;
348 static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata;
349 static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata;
350 static unsigned long required_kernelcore __initdata;
351 static unsigned long required_kernelcore_percent __initdata;
352 static unsigned long required_movablecore __initdata;
353 static unsigned long required_movablecore_percent __initdata;
354 static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
355 static bool mirrored_kernelcore __meminitdata;
357 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
359 EXPORT_SYMBOL(movable_zone);
362 unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
363 unsigned int nr_online_nodes __read_mostly = 1;
364 EXPORT_SYMBOL(nr_node_ids);
365 EXPORT_SYMBOL(nr_online_nodes);
368 int page_group_by_mobility_disabled __read_mostly;
370 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
372 * During boot we initialize deferred pages on-demand, as needed, but once
373 * page_alloc_init_late() has finished, the deferred pages are all initialized,
374 * and we can permanently disable that path.
376 static DEFINE_STATIC_KEY_TRUE(deferred_pages);
379 * Calling kasan_poison_pages() only after deferred memory initialization
380 * has completed. Poisoning pages during deferred memory init will greatly
381 * lengthen the process and cause problem in large memory systems as the
382 * deferred pages initialization is done with interrupt disabled.
384 * Assuming that there will be no reference to those newly initialized
385 * pages before they are ever allocated, this should have no effect on
386 * KASAN memory tracking as the poison will be properly inserted at page
387 * allocation time. The only corner case is when pages are allocated by
388 * on-demand allocation and then freed again before the deferred pages
389 * initialization is done, but this is not likely to happen.
391 static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags)
393 return static_branch_unlikely(&deferred_pages) ||
394 (!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
395 (fpi_flags & FPI_SKIP_KASAN_POISON)) ||
396 PageSkipKASanPoison(page);
399 /* Returns true if the struct page for the pfn is uninitialised */
400 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
402 int nid = early_pfn_to_nid(pfn);
404 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
411 * Returns true when the remaining initialisation should be deferred until
412 * later in the boot cycle when it can be parallelised.
414 static bool __meminit
415 defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
417 static unsigned long prev_end_pfn, nr_initialised;
420 * prev_end_pfn static that contains the end of previous zone
421 * No need to protect because called very early in boot before smp_init.
423 if (prev_end_pfn != end_pfn) {
424 prev_end_pfn = end_pfn;
428 /* Always populate low zones for address-constrained allocations */
429 if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
432 if (NODE_DATA(nid)->first_deferred_pfn != ULONG_MAX)
435 * We start only with one section of pages, more pages are added as
436 * needed until the rest of deferred pages are initialized.
439 if ((nr_initialised > PAGES_PER_SECTION) &&
440 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
441 NODE_DATA(nid)->first_deferred_pfn = pfn;
447 static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags)
449 return (!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
450 (fpi_flags & FPI_SKIP_KASAN_POISON)) ||
451 PageSkipKASanPoison(page);
454 static inline bool early_page_uninitialised(unsigned long pfn)
459 static inline bool defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
465 /* Return a pointer to the bitmap storing bits affecting a block of pages */
466 static inline unsigned long *get_pageblock_bitmap(const struct page *page,
469 #ifdef CONFIG_SPARSEMEM
470 return section_to_usemap(__pfn_to_section(pfn));
472 return page_zone(page)->pageblock_flags;
473 #endif /* CONFIG_SPARSEMEM */
476 static inline int pfn_to_bitidx(const struct page *page, unsigned long pfn)
478 #ifdef CONFIG_SPARSEMEM
479 pfn &= (PAGES_PER_SECTION-1);
481 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
482 #endif /* CONFIG_SPARSEMEM */
483 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
486 static __always_inline
487 unsigned long __get_pfnblock_flags_mask(const struct page *page,
491 unsigned long *bitmap;
492 unsigned long bitidx, word_bitidx;
495 bitmap = get_pageblock_bitmap(page, pfn);
496 bitidx = pfn_to_bitidx(page, pfn);
497 word_bitidx = bitidx / BITS_PER_LONG;
498 bitidx &= (BITS_PER_LONG-1);
500 word = bitmap[word_bitidx];
501 return (word >> bitidx) & mask;
505 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
506 * @page: The page within the block of interest
507 * @pfn: The target page frame number
508 * @mask: mask of bits that the caller is interested in
510 * Return: pageblock_bits flags
512 unsigned long get_pfnblock_flags_mask(const struct page *page,
513 unsigned long pfn, unsigned long mask)
515 return __get_pfnblock_flags_mask(page, pfn, mask);
518 static __always_inline int get_pfnblock_migratetype(const struct page *page,
521 return __get_pfnblock_flags_mask(page, pfn, MIGRATETYPE_MASK);
525 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
526 * @page: The page within the block of interest
527 * @flags: The flags to set
528 * @pfn: The target page frame number
529 * @mask: mask of bits that the caller is interested in
531 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
535 unsigned long *bitmap;
536 unsigned long bitidx, word_bitidx;
537 unsigned long old_word, word;
539 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
540 BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
542 bitmap = get_pageblock_bitmap(page, pfn);
543 bitidx = pfn_to_bitidx(page, pfn);
544 word_bitidx = bitidx / BITS_PER_LONG;
545 bitidx &= (BITS_PER_LONG-1);
547 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
552 word = READ_ONCE(bitmap[word_bitidx]);
554 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
555 if (word == old_word)
561 void set_pageblock_migratetype(struct page *page, int migratetype)
563 if (unlikely(page_group_by_mobility_disabled &&
564 migratetype < MIGRATE_PCPTYPES))
565 migratetype = MIGRATE_UNMOVABLE;
567 set_pfnblock_flags_mask(page, (unsigned long)migratetype,
568 page_to_pfn(page), MIGRATETYPE_MASK);
571 #ifdef CONFIG_DEBUG_VM
572 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
576 unsigned long pfn = page_to_pfn(page);
577 unsigned long sp, start_pfn;
580 seq = zone_span_seqbegin(zone);
581 start_pfn = zone->zone_start_pfn;
582 sp = zone->spanned_pages;
583 if (!zone_spans_pfn(zone, pfn))
585 } while (zone_span_seqretry(zone, seq));
588 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
589 pfn, zone_to_nid(zone), zone->name,
590 start_pfn, start_pfn + sp);
595 static int page_is_consistent(struct zone *zone, struct page *page)
597 if (zone != page_zone(page))
603 * Temporary debugging check for pages not lying within a given zone.
605 static int __maybe_unused bad_range(struct zone *zone, struct page *page)
607 if (page_outside_zone_boundaries(zone, page))
609 if (!page_is_consistent(zone, page))
615 static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
621 static void bad_page(struct page *page, const char *reason)
623 static unsigned long resume;
624 static unsigned long nr_shown;
625 static unsigned long nr_unshown;
628 * Allow a burst of 60 reports, then keep quiet for that minute;
629 * or allow a steady drip of one report per second.
631 if (nr_shown == 60) {
632 if (time_before(jiffies, resume)) {
638 "BUG: Bad page state: %lu messages suppressed\n",
645 resume = jiffies + 60 * HZ;
647 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
648 current->comm, page_to_pfn(page));
649 dump_page(page, reason);
654 /* Leave bad fields for debug, except PageBuddy could make trouble */
655 page_mapcount_reset(page); /* remove PageBuddy */
656 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
659 static inline unsigned int order_to_pindex(int migratetype, int order)
663 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
664 if (order > PAGE_ALLOC_COSTLY_ORDER) {
665 VM_BUG_ON(order != pageblock_order);
666 base = PAGE_ALLOC_COSTLY_ORDER + 1;
669 VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
672 return (MIGRATE_PCPTYPES * base) + migratetype;
675 static inline int pindex_to_order(unsigned int pindex)
677 int order = pindex / MIGRATE_PCPTYPES;
679 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
680 if (order > PAGE_ALLOC_COSTLY_ORDER) {
681 order = pageblock_order;
682 VM_BUG_ON(order != pageblock_order);
685 VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
691 static inline bool pcp_allowed_order(unsigned int order)
693 if (order <= PAGE_ALLOC_COSTLY_ORDER)
695 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
696 if (order == pageblock_order)
702 static inline void free_the_page(struct page *page, unsigned int order)
704 if (pcp_allowed_order(order)) /* Via pcp? */
705 free_unref_page(page, order);
707 __free_pages_ok(page, order, FPI_NONE);
711 * Higher-order pages are called "compound pages". They are structured thusly:
713 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
715 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
716 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
718 * The first tail page's ->compound_dtor holds the offset in array of compound
719 * page destructors. See compound_page_dtors.
721 * The first tail page's ->compound_order holds the order of allocation.
722 * This usage means that zero-order pages may not be compound.
725 void free_compound_page(struct page *page)
727 mem_cgroup_uncharge(page_folio(page));
728 free_the_page(page, compound_order(page));
731 void prep_compound_page(struct page *page, unsigned int order)
734 int nr_pages = 1 << order;
737 for (i = 1; i < nr_pages; i++) {
738 struct page *p = page + i;
739 p->mapping = TAIL_MAPPING;
740 set_compound_head(p, page);
743 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
744 set_compound_order(page, order);
745 atomic_set(compound_mapcount_ptr(page), -1);
746 if (hpage_pincount_available(page))
747 atomic_set(compound_pincount_ptr(page), 0);
750 #ifdef CONFIG_DEBUG_PAGEALLOC
751 unsigned int _debug_guardpage_minorder;
753 bool _debug_pagealloc_enabled_early __read_mostly
754 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
755 EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
756 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
757 EXPORT_SYMBOL(_debug_pagealloc_enabled);
759 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
761 static int __init early_debug_pagealloc(char *buf)
763 return kstrtobool(buf, &_debug_pagealloc_enabled_early);
765 early_param("debug_pagealloc", early_debug_pagealloc);
767 static int __init debug_guardpage_minorder_setup(char *buf)
771 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
772 pr_err("Bad debug_guardpage_minorder value\n");
775 _debug_guardpage_minorder = res;
776 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
779 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
781 static inline bool set_page_guard(struct zone *zone, struct page *page,
782 unsigned int order, int migratetype)
784 if (!debug_guardpage_enabled())
787 if (order >= debug_guardpage_minorder())
790 __SetPageGuard(page);
791 INIT_LIST_HEAD(&page->lru);
792 set_page_private(page, order);
793 /* Guard pages are not available for any usage */
794 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
799 static inline void clear_page_guard(struct zone *zone, struct page *page,
800 unsigned int order, int migratetype)
802 if (!debug_guardpage_enabled())
805 __ClearPageGuard(page);
807 set_page_private(page, 0);
808 if (!is_migrate_isolate(migratetype))
809 __mod_zone_freepage_state(zone, (1 << order), migratetype);
812 static inline bool set_page_guard(struct zone *zone, struct page *page,
813 unsigned int order, int migratetype) { return false; }
814 static inline void clear_page_guard(struct zone *zone, struct page *page,
815 unsigned int order, int migratetype) {}
819 * Enable static keys related to various memory debugging and hardening options.
820 * Some override others, and depend on early params that are evaluated in the
821 * order of appearance. So we need to first gather the full picture of what was
822 * enabled, and then make decisions.
824 void init_mem_debugging_and_hardening(void)
826 bool page_poisoning_requested = false;
828 #ifdef CONFIG_PAGE_POISONING
830 * Page poisoning is debug page alloc for some arches. If
831 * either of those options are enabled, enable poisoning.
833 if (page_poisoning_enabled() ||
834 (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
835 debug_pagealloc_enabled())) {
836 static_branch_enable(&_page_poisoning_enabled);
837 page_poisoning_requested = true;
841 if ((_init_on_alloc_enabled_early || _init_on_free_enabled_early) &&
842 page_poisoning_requested) {
843 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
844 "will take precedence over init_on_alloc and init_on_free\n");
845 _init_on_alloc_enabled_early = false;
846 _init_on_free_enabled_early = false;
849 if (_init_on_alloc_enabled_early)
850 static_branch_enable(&init_on_alloc);
852 static_branch_disable(&init_on_alloc);
854 if (_init_on_free_enabled_early)
855 static_branch_enable(&init_on_free);
857 static_branch_disable(&init_on_free);
859 #ifdef CONFIG_DEBUG_PAGEALLOC
860 if (!debug_pagealloc_enabled())
863 static_branch_enable(&_debug_pagealloc_enabled);
865 if (!debug_guardpage_minorder())
868 static_branch_enable(&_debug_guardpage_enabled);
872 static inline void set_buddy_order(struct page *page, unsigned int order)
874 set_page_private(page, order);
875 __SetPageBuddy(page);
879 * This function checks whether a page is free && is the buddy
880 * we can coalesce a page and its buddy if
881 * (a) the buddy is not in a hole (check before calling!) &&
882 * (b) the buddy is in the buddy system &&
883 * (c) a page and its buddy have the same order &&
884 * (d) a page and its buddy are in the same zone.
886 * For recording whether a page is in the buddy system, we set PageBuddy.
887 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
889 * For recording page's order, we use page_private(page).
891 static inline bool page_is_buddy(struct page *page, struct page *buddy,
894 if (!page_is_guard(buddy) && !PageBuddy(buddy))
897 if (buddy_order(buddy) != order)
901 * zone check is done late to avoid uselessly calculating
902 * zone/node ids for pages that could never merge.
904 if (page_zone_id(page) != page_zone_id(buddy))
907 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
912 #ifdef CONFIG_COMPACTION
913 static inline struct capture_control *task_capc(struct zone *zone)
915 struct capture_control *capc = current->capture_control;
917 return unlikely(capc) &&
918 !(current->flags & PF_KTHREAD) &&
920 capc->cc->zone == zone ? capc : NULL;
924 compaction_capture(struct capture_control *capc, struct page *page,
925 int order, int migratetype)
927 if (!capc || order != capc->cc->order)
930 /* Do not accidentally pollute CMA or isolated regions*/
931 if (is_migrate_cma(migratetype) ||
932 is_migrate_isolate(migratetype))
936 * Do not let lower order allocations pollute a movable pageblock.
937 * This might let an unmovable request use a reclaimable pageblock
938 * and vice-versa but no more than normal fallback logic which can
939 * have trouble finding a high-order free page.
941 if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
949 static inline struct capture_control *task_capc(struct zone *zone)
955 compaction_capture(struct capture_control *capc, struct page *page,
956 int order, int migratetype)
960 #endif /* CONFIG_COMPACTION */
962 /* Used for pages not on another list */
963 static inline void add_to_free_list(struct page *page, struct zone *zone,
964 unsigned int order, int migratetype)
966 struct free_area *area = &zone->free_area[order];
968 list_add(&page->lru, &area->free_list[migratetype]);
972 /* Used for pages not on another list */
973 static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
974 unsigned int order, int migratetype)
976 struct free_area *area = &zone->free_area[order];
978 list_add_tail(&page->lru, &area->free_list[migratetype]);
983 * Used for pages which are on another list. Move the pages to the tail
984 * of the list - so the moved pages won't immediately be considered for
985 * allocation again (e.g., optimization for memory onlining).
987 static inline void move_to_free_list(struct page *page, struct zone *zone,
988 unsigned int order, int migratetype)
990 struct free_area *area = &zone->free_area[order];
992 list_move_tail(&page->lru, &area->free_list[migratetype]);
995 static inline void del_page_from_free_list(struct page *page, struct zone *zone,
998 /* clear reported state and update reported page count */
999 if (page_reported(page))
1000 __ClearPageReported(page);
1002 list_del(&page->lru);
1003 __ClearPageBuddy(page);
1004 set_page_private(page, 0);
1005 zone->free_area[order].nr_free--;
1009 * If this is not the largest possible page, check if the buddy
1010 * of the next-highest order is free. If it is, it's possible
1011 * that pages are being freed that will coalesce soon. In case,
1012 * that is happening, add the free page to the tail of the list
1013 * so it's less likely to be used soon and more likely to be merged
1014 * as a higher order page
1017 buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
1018 struct page *page, unsigned int order)
1020 struct page *higher_page, *higher_buddy;
1021 unsigned long combined_pfn;
1023 if (order >= MAX_ORDER - 2)
1026 combined_pfn = buddy_pfn & pfn;
1027 higher_page = page + (combined_pfn - pfn);
1028 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
1029 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
1031 return page_is_buddy(higher_page, higher_buddy, order + 1);
1035 * Freeing function for a buddy system allocator.
1037 * The concept of a buddy system is to maintain direct-mapped table
1038 * (containing bit values) for memory blocks of various "orders".
1039 * The bottom level table contains the map for the smallest allocatable
1040 * units of memory (here, pages), and each level above it describes
1041 * pairs of units from the levels below, hence, "buddies".
1042 * At a high level, all that happens here is marking the table entry
1043 * at the bottom level available, and propagating the changes upward
1044 * as necessary, plus some accounting needed to play nicely with other
1045 * parts of the VM system.
1046 * At each level, we keep a list of pages, which are heads of continuous
1047 * free pages of length of (1 << order) and marked with PageBuddy.
1048 * Page's order is recorded in page_private(page) field.
1049 * So when we are allocating or freeing one, we can derive the state of the
1050 * other. That is, if we allocate a small block, and both were
1051 * free, the remainder of the region must be split into blocks.
1052 * If a block is freed, and its buddy is also free, then this
1053 * triggers coalescing into a block of larger size.
1058 static inline void __free_one_page(struct page *page,
1060 struct zone *zone, unsigned int order,
1061 int migratetype, fpi_t fpi_flags)
1063 struct capture_control *capc = task_capc(zone);
1064 unsigned long buddy_pfn;
1065 unsigned long combined_pfn;
1066 unsigned int max_order;
1070 max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order);
1072 VM_BUG_ON(!zone_is_initialized(zone));
1073 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
1075 VM_BUG_ON(migratetype == -1);
1076 if (likely(!is_migrate_isolate(migratetype)))
1077 __mod_zone_freepage_state(zone, 1 << order, migratetype);
1079 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
1080 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1083 while (order < max_order) {
1084 if (compaction_capture(capc, page, order, migratetype)) {
1085 __mod_zone_freepage_state(zone, -(1 << order),
1089 buddy_pfn = __find_buddy_pfn(pfn, order);
1090 buddy = page + (buddy_pfn - pfn);
1092 if (!page_is_buddy(page, buddy, order))
1095 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
1096 * merge with it and move up one order.
1098 if (page_is_guard(buddy))
1099 clear_page_guard(zone, buddy, order, migratetype);
1101 del_page_from_free_list(buddy, zone, order);
1102 combined_pfn = buddy_pfn & pfn;
1103 page = page + (combined_pfn - pfn);
1107 if (order < MAX_ORDER - 1) {
1108 /* If we are here, it means order is >= pageblock_order.
1109 * We want to prevent merge between freepages on isolate
1110 * pageblock and normal pageblock. Without this, pageblock
1111 * isolation could cause incorrect freepage or CMA accounting.
1113 * We don't want to hit this code for the more frequent
1114 * low-order merging.
1116 if (unlikely(has_isolate_pageblock(zone))) {
1119 buddy_pfn = __find_buddy_pfn(pfn, order);
1120 buddy = page + (buddy_pfn - pfn);
1121 buddy_mt = get_pageblock_migratetype(buddy);
1123 if (migratetype != buddy_mt
1124 && (is_migrate_isolate(migratetype) ||
1125 is_migrate_isolate(buddy_mt)))
1128 max_order = order + 1;
1129 goto continue_merging;
1133 set_buddy_order(page, order);
1135 if (fpi_flags & FPI_TO_TAIL)
1137 else if (is_shuffle_order(order))
1138 to_tail = shuffle_pick_tail();
1140 to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
1143 add_to_free_list_tail(page, zone, order, migratetype);
1145 add_to_free_list(page, zone, order, migratetype);
1147 /* Notify page reporting subsystem of freed page */
1148 if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY))
1149 page_reporting_notify_free(order);
1153 * A bad page could be due to a number of fields. Instead of multiple branches,
1154 * try and check multiple fields with one check. The caller must do a detailed
1155 * check if necessary.
1157 static inline bool page_expected_state(struct page *page,
1158 unsigned long check_flags)
1160 if (unlikely(atomic_read(&page->_mapcount) != -1))
1163 if (unlikely((unsigned long)page->mapping |
1164 page_ref_count(page) |
1168 (page->flags & check_flags)))
1174 static const char *page_bad_reason(struct page *page, unsigned long flags)
1176 const char *bad_reason = NULL;
1178 if (unlikely(atomic_read(&page->_mapcount) != -1))
1179 bad_reason = "nonzero mapcount";
1180 if (unlikely(page->mapping != NULL))
1181 bad_reason = "non-NULL mapping";
1182 if (unlikely(page_ref_count(page) != 0))
1183 bad_reason = "nonzero _refcount";
1184 if (unlikely(page->flags & flags)) {
1185 if (flags == PAGE_FLAGS_CHECK_AT_PREP)
1186 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1188 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1191 if (unlikely(page->memcg_data))
1192 bad_reason = "page still charged to cgroup";
1197 static void check_free_page_bad(struct page *page)
1200 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_FREE));
1203 static inline int check_free_page(struct page *page)
1205 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
1208 /* Something has gone sideways, find it */
1209 check_free_page_bad(page);
1213 static int free_tail_pages_check(struct page *head_page, struct page *page)
1218 * We rely page->lru.next never has bit 0 set, unless the page
1219 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1221 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
1223 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
1227 switch (page - head_page) {
1229 /* the first tail page: ->mapping may be compound_mapcount() */
1230 if (unlikely(compound_mapcount(page))) {
1231 bad_page(page, "nonzero compound_mapcount");
1237 * the second tail page: ->mapping is
1238 * deferred_list.next -- ignore value.
1242 if (page->mapping != TAIL_MAPPING) {
1243 bad_page(page, "corrupted mapping in tail page");
1248 if (unlikely(!PageTail(page))) {
1249 bad_page(page, "PageTail not set");
1252 if (unlikely(compound_head(page) != head_page)) {
1253 bad_page(page, "compound_head not consistent");
1258 page->mapping = NULL;
1259 clear_compound_head(page);
1263 static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags)
1268 for (i = 0; i < numpages; i++)
1269 tag_clear_highpage(page + i);
1273 /* s390's use of memset() could override KASAN redzones. */
1274 kasan_disable_current();
1275 for (i = 0; i < numpages; i++) {
1276 u8 tag = page_kasan_tag(page + i);
1277 page_kasan_tag_reset(page + i);
1278 clear_highpage(page + i);
1279 page_kasan_tag_set(page + i, tag);
1281 kasan_enable_current();
1284 static __always_inline bool free_pages_prepare(struct page *page,
1285 unsigned int order, bool check_free, fpi_t fpi_flags)
1288 bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags);
1290 VM_BUG_ON_PAGE(PageTail(page), page);
1292 trace_mm_page_free(page, order);
1294 if (unlikely(PageHWPoison(page)) && !order) {
1296 * Do not let hwpoison pages hit pcplists/buddy
1297 * Untie memcg state and reset page's owner
1299 if (memcg_kmem_enabled() && PageMemcgKmem(page))
1300 __memcg_kmem_uncharge_page(page, order);
1301 reset_page_owner(page, order);
1306 * Check tail pages before head page information is cleared to
1307 * avoid checking PageCompound for order-0 pages.
1309 if (unlikely(order)) {
1310 bool compound = PageCompound(page);
1313 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1316 ClearPageDoubleMap(page);
1317 ClearPageHasHWPoisoned(page);
1319 for (i = 1; i < (1 << order); i++) {
1321 bad += free_tail_pages_check(page, page + i);
1322 if (unlikely(check_free_page(page + i))) {
1326 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1329 if (PageMappingFlags(page))
1330 page->mapping = NULL;
1331 if (memcg_kmem_enabled() && PageMemcgKmem(page))
1332 __memcg_kmem_uncharge_page(page, order);
1334 bad += check_free_page(page);
1338 page_cpupid_reset_last(page);
1339 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1340 reset_page_owner(page, order);
1342 if (!PageHighMem(page)) {
1343 debug_check_no_locks_freed(page_address(page),
1344 PAGE_SIZE << order);
1345 debug_check_no_obj_freed(page_address(page),
1346 PAGE_SIZE << order);
1349 kernel_poison_pages(page, 1 << order);
1352 * As memory initialization might be integrated into KASAN,
1353 * kasan_free_pages and kernel_init_free_pages must be
1354 * kept together to avoid discrepancies in behavior.
1356 * With hardware tag-based KASAN, memory tags must be set before the
1357 * page becomes unavailable via debug_pagealloc or arch_free_page.
1359 if (kasan_has_integrated_init()) {
1360 if (!skip_kasan_poison)
1361 kasan_free_pages(page, order);
1363 bool init = want_init_on_free();
1366 kernel_init_free_pages(page, 1 << order, false);
1367 if (!skip_kasan_poison)
1368 kasan_poison_pages(page, order, init);
1372 * arch_free_page() can make the page's contents inaccessible. s390
1373 * does this. So nothing which can access the page's contents should
1374 * happen after this.
1376 arch_free_page(page, order);
1378 debug_pagealloc_unmap_pages(page, 1 << order);
1383 #ifdef CONFIG_DEBUG_VM
1385 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1386 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1387 * moved from pcp lists to free lists.
1389 static bool free_pcp_prepare(struct page *page, unsigned int order)
1391 return free_pages_prepare(page, order, true, FPI_NONE);
1394 static bool bulkfree_pcp_prepare(struct page *page)
1396 if (debug_pagealloc_enabled_static())
1397 return check_free_page(page);
1403 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1404 * moving from pcp lists to free list in order to reduce overhead. With
1405 * debug_pagealloc enabled, they are checked also immediately when being freed
1408 static bool free_pcp_prepare(struct page *page, unsigned int order)
1410 if (debug_pagealloc_enabled_static())
1411 return free_pages_prepare(page, order, true, FPI_NONE);
1413 return free_pages_prepare(page, order, false, FPI_NONE);
1416 static bool bulkfree_pcp_prepare(struct page *page)
1418 return check_free_page(page);
1420 #endif /* CONFIG_DEBUG_VM */
1422 static inline void prefetch_buddy(struct page *page)
1424 unsigned long pfn = page_to_pfn(page);
1425 unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0);
1426 struct page *buddy = page + (buddy_pfn - pfn);
1432 * Frees a number of pages from the PCP lists
1433 * Assumes all pages on list are in same zone, and of same order.
1434 * count is the number of pages to free.
1436 * If the zone was previously in an "all pages pinned" state then look to
1437 * see if this freeing clears that state.
1439 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1440 * pinned" detection logic.
1442 static void free_pcppages_bulk(struct zone *zone, int count,
1443 struct per_cpu_pages *pcp)
1449 int prefetch_nr = READ_ONCE(pcp->batch);
1450 bool isolated_pageblocks;
1451 struct page *page, *tmp;
1455 * Ensure proper count is passed which otherwise would stuck in the
1456 * below while (list_empty(list)) loop.
1458 count = min(pcp->count, count);
1460 struct list_head *list;
1463 * Remove pages from lists in a round-robin fashion. A
1464 * batch_free count is maintained that is incremented when an
1465 * empty list is encountered. This is so more pages are freed
1466 * off fuller lists instead of spinning excessively around empty
1471 if (++pindex == NR_PCP_LISTS)
1473 list = &pcp->lists[pindex];
1474 } while (list_empty(list));
1476 /* This is the only non-empty list. Free them all. */
1477 if (batch_free == NR_PCP_LISTS)
1480 order = pindex_to_order(pindex);
1481 BUILD_BUG_ON(MAX_ORDER >= (1<<NR_PCP_ORDER_WIDTH));
1483 page = list_last_entry(list, struct page, lru);
1484 /* must delete to avoid corrupting pcp list */
1485 list_del(&page->lru);
1486 nr_freed += 1 << order;
1487 count -= 1 << order;
1489 if (bulkfree_pcp_prepare(page))
1492 /* Encode order with the migratetype */
1493 page->index <<= NR_PCP_ORDER_WIDTH;
1494 page->index |= order;
1496 list_add_tail(&page->lru, &head);
1499 * We are going to put the page back to the global
1500 * pool, prefetch its buddy to speed up later access
1501 * under zone->lock. It is believed the overhead of
1502 * an additional test and calculating buddy_pfn here
1503 * can be offset by reduced memory latency later. To
1504 * avoid excessive prefetching due to large count, only
1505 * prefetch buddy for the first pcp->batch nr of pages.
1508 prefetch_buddy(page);
1511 } while (count > 0 && --batch_free && !list_empty(list));
1513 pcp->count -= nr_freed;
1516 * local_lock_irq held so equivalent to spin_lock_irqsave for
1517 * both PREEMPT_RT and non-PREEMPT_RT configurations.
1519 spin_lock(&zone->lock);
1520 isolated_pageblocks = has_isolate_pageblock(zone);
1523 * Use safe version since after __free_one_page(),
1524 * page->lru.next will not point to original list.
1526 list_for_each_entry_safe(page, tmp, &head, lru) {
1527 int mt = get_pcppage_migratetype(page);
1529 /* mt has been encoded with the order (see above) */
1530 order = mt & NR_PCP_ORDER_MASK;
1531 mt >>= NR_PCP_ORDER_WIDTH;
1533 /* MIGRATE_ISOLATE page should not go to pcplists */
1534 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1535 /* Pageblock could have been isolated meanwhile */
1536 if (unlikely(isolated_pageblocks))
1537 mt = get_pageblock_migratetype(page);
1539 __free_one_page(page, page_to_pfn(page), zone, order, mt, FPI_NONE);
1540 trace_mm_page_pcpu_drain(page, order, mt);
1542 spin_unlock(&zone->lock);
1545 static void free_one_page(struct zone *zone,
1546 struct page *page, unsigned long pfn,
1548 int migratetype, fpi_t fpi_flags)
1550 unsigned long flags;
1552 spin_lock_irqsave(&zone->lock, flags);
1553 if (unlikely(has_isolate_pageblock(zone) ||
1554 is_migrate_isolate(migratetype))) {
1555 migratetype = get_pfnblock_migratetype(page, pfn);
1557 __free_one_page(page, pfn, zone, order, migratetype, fpi_flags);
1558 spin_unlock_irqrestore(&zone->lock, flags);
1561 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1562 unsigned long zone, int nid)
1564 mm_zero_struct_page(page);
1565 set_page_links(page, zone, nid, pfn);
1566 init_page_count(page);
1567 page_mapcount_reset(page);
1568 page_cpupid_reset_last(page);
1569 page_kasan_tag_reset(page);
1571 INIT_LIST_HEAD(&page->lru);
1572 #ifdef WANT_PAGE_VIRTUAL
1573 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1574 if (!is_highmem_idx(zone))
1575 set_page_address(page, __va(pfn << PAGE_SHIFT));
1579 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1580 static void __meminit init_reserved_page(unsigned long pfn)
1585 if (!early_page_uninitialised(pfn))
1588 nid = early_pfn_to_nid(pfn);
1589 pgdat = NODE_DATA(nid);
1591 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1592 struct zone *zone = &pgdat->node_zones[zid];
1594 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1597 __init_single_page(pfn_to_page(pfn), pfn, zid, nid);
1600 static inline void init_reserved_page(unsigned long pfn)
1603 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1606 * Initialised pages do not have PageReserved set. This function is
1607 * called for each range allocated by the bootmem allocator and
1608 * marks the pages PageReserved. The remaining valid pages are later
1609 * sent to the buddy page allocator.
1611 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1613 unsigned long start_pfn = PFN_DOWN(start);
1614 unsigned long end_pfn = PFN_UP(end);
1616 for (; start_pfn < end_pfn; start_pfn++) {
1617 if (pfn_valid(start_pfn)) {
1618 struct page *page = pfn_to_page(start_pfn);
1620 init_reserved_page(start_pfn);
1622 /* Avoid false-positive PageTail() */
1623 INIT_LIST_HEAD(&page->lru);
1626 * no need for atomic set_bit because the struct
1627 * page is not visible yet so nobody should
1630 __SetPageReserved(page);
1635 static void __free_pages_ok(struct page *page, unsigned int order,
1638 unsigned long flags;
1640 unsigned long pfn = page_to_pfn(page);
1641 struct zone *zone = page_zone(page);
1643 if (!free_pages_prepare(page, order, true, fpi_flags))
1646 migratetype = get_pfnblock_migratetype(page, pfn);
1648 spin_lock_irqsave(&zone->lock, flags);
1649 if (unlikely(has_isolate_pageblock(zone) ||
1650 is_migrate_isolate(migratetype))) {
1651 migratetype = get_pfnblock_migratetype(page, pfn);
1653 __free_one_page(page, pfn, zone, order, migratetype, fpi_flags);
1654 spin_unlock_irqrestore(&zone->lock, flags);
1656 __count_vm_events(PGFREE, 1 << order);
1659 void __free_pages_core(struct page *page, unsigned int order)
1661 unsigned int nr_pages = 1 << order;
1662 struct page *p = page;
1666 * When initializing the memmap, __init_single_page() sets the refcount
1667 * of all pages to 1 ("allocated"/"not free"). We have to set the
1668 * refcount of all involved pages to 0.
1671 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1673 __ClearPageReserved(p);
1674 set_page_count(p, 0);
1676 __ClearPageReserved(p);
1677 set_page_count(p, 0);
1679 atomic_long_add(nr_pages, &page_zone(page)->managed_pages);
1682 * Bypass PCP and place fresh pages right to the tail, primarily
1683 * relevant for memory onlining.
1685 __free_pages_ok(page, order, FPI_TO_TAIL | FPI_SKIP_KASAN_POISON);
1691 * During memory init memblocks map pfns to nids. The search is expensive and
1692 * this caches recent lookups. The implementation of __early_pfn_to_nid
1693 * treats start/end as pfns.
1695 struct mminit_pfnnid_cache {
1696 unsigned long last_start;
1697 unsigned long last_end;
1701 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1704 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1706 static int __meminit __early_pfn_to_nid(unsigned long pfn,
1707 struct mminit_pfnnid_cache *state)
1709 unsigned long start_pfn, end_pfn;
1712 if (state->last_start <= pfn && pfn < state->last_end)
1713 return state->last_nid;
1715 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
1716 if (nid != NUMA_NO_NODE) {
1717 state->last_start = start_pfn;
1718 state->last_end = end_pfn;
1719 state->last_nid = nid;
1725 int __meminit early_pfn_to_nid(unsigned long pfn)
1727 static DEFINE_SPINLOCK(early_pfn_lock);
1730 spin_lock(&early_pfn_lock);
1731 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1733 nid = first_online_node;
1734 spin_unlock(&early_pfn_lock);
1738 #endif /* CONFIG_NUMA */
1740 void __init memblock_free_pages(struct page *page, unsigned long pfn,
1743 if (early_page_uninitialised(pfn))
1745 __free_pages_core(page, order);
1749 * Check that the whole (or subset of) a pageblock given by the interval of
1750 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1751 * with the migration of free compaction scanner.
1753 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1755 * It's possible on some configurations to have a setup like node0 node1 node0
1756 * i.e. it's possible that all pages within a zones range of pages do not
1757 * belong to a single zone. We assume that a border between node0 and node1
1758 * can occur within a single pageblock, but not a node0 node1 node0
1759 * interleaving within a single pageblock. It is therefore sufficient to check
1760 * the first and last page of a pageblock and avoid checking each individual
1761 * page in a pageblock.
1763 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1764 unsigned long end_pfn, struct zone *zone)
1766 struct page *start_page;
1767 struct page *end_page;
1769 /* end_pfn is one past the range we are checking */
1772 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1775 start_page = pfn_to_online_page(start_pfn);
1779 if (page_zone(start_page) != zone)
1782 end_page = pfn_to_page(end_pfn);
1784 /* This gives a shorter code than deriving page_zone(end_page) */
1785 if (page_zone_id(start_page) != page_zone_id(end_page))
1791 void set_zone_contiguous(struct zone *zone)
1793 unsigned long block_start_pfn = zone->zone_start_pfn;
1794 unsigned long block_end_pfn;
1796 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1797 for (; block_start_pfn < zone_end_pfn(zone);
1798 block_start_pfn = block_end_pfn,
1799 block_end_pfn += pageblock_nr_pages) {
1801 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1803 if (!__pageblock_pfn_to_page(block_start_pfn,
1804 block_end_pfn, zone))
1809 /* We confirm that there is no hole */
1810 zone->contiguous = true;
1813 void clear_zone_contiguous(struct zone *zone)
1815 zone->contiguous = false;
1818 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1819 static void __init deferred_free_range(unsigned long pfn,
1820 unsigned long nr_pages)
1828 page = pfn_to_page(pfn);
1830 /* Free a large naturally-aligned chunk if possible */
1831 if (nr_pages == pageblock_nr_pages &&
1832 (pfn & (pageblock_nr_pages - 1)) == 0) {
1833 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1834 __free_pages_core(page, pageblock_order);
1838 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1839 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1840 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1841 __free_pages_core(page, 0);
1845 /* Completion tracking for deferred_init_memmap() threads */
1846 static atomic_t pgdat_init_n_undone __initdata;
1847 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1849 static inline void __init pgdat_init_report_one_done(void)
1851 if (atomic_dec_and_test(&pgdat_init_n_undone))
1852 complete(&pgdat_init_all_done_comp);
1856 * Returns true if page needs to be initialized or freed to buddy allocator.
1858 * First we check if pfn is valid on architectures where it is possible to have
1859 * holes within pageblock_nr_pages. On systems where it is not possible, this
1860 * function is optimized out.
1862 * Then, we check if a current large page is valid by only checking the validity
1865 static inline bool __init deferred_pfn_valid(unsigned long pfn)
1867 if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
1873 * Free pages to buddy allocator. Try to free aligned pages in
1874 * pageblock_nr_pages sizes.
1876 static void __init deferred_free_pages(unsigned long pfn,
1877 unsigned long end_pfn)
1879 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1880 unsigned long nr_free = 0;
1882 for (; pfn < end_pfn; pfn++) {
1883 if (!deferred_pfn_valid(pfn)) {
1884 deferred_free_range(pfn - nr_free, nr_free);
1886 } else if (!(pfn & nr_pgmask)) {
1887 deferred_free_range(pfn - nr_free, nr_free);
1893 /* Free the last block of pages to allocator */
1894 deferred_free_range(pfn - nr_free, nr_free);
1898 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1899 * by performing it only once every pageblock_nr_pages.
1900 * Return number of pages initialized.
1902 static unsigned long __init deferred_init_pages(struct zone *zone,
1904 unsigned long end_pfn)
1906 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1907 int nid = zone_to_nid(zone);
1908 unsigned long nr_pages = 0;
1909 int zid = zone_idx(zone);
1910 struct page *page = NULL;
1912 for (; pfn < end_pfn; pfn++) {
1913 if (!deferred_pfn_valid(pfn)) {
1916 } else if (!page || !(pfn & nr_pgmask)) {
1917 page = pfn_to_page(pfn);
1921 __init_single_page(page, pfn, zid, nid);
1928 * This function is meant to pre-load the iterator for the zone init.
1929 * Specifically it walks through the ranges until we are caught up to the
1930 * first_init_pfn value and exits there. If we never encounter the value we
1931 * return false indicating there are no valid ranges left.
1934 deferred_init_mem_pfn_range_in_zone(u64 *i, struct zone *zone,
1935 unsigned long *spfn, unsigned long *epfn,
1936 unsigned long first_init_pfn)
1941 * Start out by walking through the ranges in this zone that have
1942 * already been initialized. We don't need to do anything with them
1943 * so we just need to flush them out of the system.
1945 for_each_free_mem_pfn_range_in_zone(j, zone, spfn, epfn) {
1946 if (*epfn <= first_init_pfn)
1948 if (*spfn < first_init_pfn)
1949 *spfn = first_init_pfn;
1958 * Initialize and free pages. We do it in two loops: first we initialize
1959 * struct page, then free to buddy allocator, because while we are
1960 * freeing pages we can access pages that are ahead (computing buddy
1961 * page in __free_one_page()).
1963 * In order to try and keep some memory in the cache we have the loop
1964 * broken along max page order boundaries. This way we will not cause
1965 * any issues with the buddy page computation.
1967 static unsigned long __init
1968 deferred_init_maxorder(u64 *i, struct zone *zone, unsigned long *start_pfn,
1969 unsigned long *end_pfn)
1971 unsigned long mo_pfn = ALIGN(*start_pfn + 1, MAX_ORDER_NR_PAGES);
1972 unsigned long spfn = *start_pfn, epfn = *end_pfn;
1973 unsigned long nr_pages = 0;
1976 /* First we loop through and initialize the page values */
1977 for_each_free_mem_pfn_range_in_zone_from(j, zone, start_pfn, end_pfn) {
1980 if (mo_pfn <= *start_pfn)
1983 t = min(mo_pfn, *end_pfn);
1984 nr_pages += deferred_init_pages(zone, *start_pfn, t);
1986 if (mo_pfn < *end_pfn) {
1987 *start_pfn = mo_pfn;
1992 /* Reset values and now loop through freeing pages as needed */
1995 for_each_free_mem_pfn_range_in_zone_from(j, zone, &spfn, &epfn) {
2001 t = min(mo_pfn, epfn);
2002 deferred_free_pages(spfn, t);
2012 deferred_init_memmap_chunk(unsigned long start_pfn, unsigned long end_pfn,
2015 unsigned long spfn, epfn;
2016 struct zone *zone = arg;
2019 deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, start_pfn);
2022 * Initialize and free pages in MAX_ORDER sized increments so that we
2023 * can avoid introducing any issues with the buddy allocator.
2025 while (spfn < end_pfn) {
2026 deferred_init_maxorder(&i, zone, &spfn, &epfn);
2031 /* An arch may override for more concurrency. */
2033 deferred_page_init_max_threads(const struct cpumask *node_cpumask)
2038 /* Initialise remaining memory on a node */
2039 static int __init deferred_init_memmap(void *data)
2041 pg_data_t *pgdat = data;
2042 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
2043 unsigned long spfn = 0, epfn = 0;
2044 unsigned long first_init_pfn, flags;
2045 unsigned long start = jiffies;
2047 int zid, max_threads;
2050 /* Bind memory initialisation thread to a local node if possible */
2051 if (!cpumask_empty(cpumask))
2052 set_cpus_allowed_ptr(current, cpumask);
2054 pgdat_resize_lock(pgdat, &flags);
2055 first_init_pfn = pgdat->first_deferred_pfn;
2056 if (first_init_pfn == ULONG_MAX) {
2057 pgdat_resize_unlock(pgdat, &flags);
2058 pgdat_init_report_one_done();
2062 /* Sanity check boundaries */
2063 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
2064 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
2065 pgdat->first_deferred_pfn = ULONG_MAX;
2068 * Once we unlock here, the zone cannot be grown anymore, thus if an
2069 * interrupt thread must allocate this early in boot, zone must be
2070 * pre-grown prior to start of deferred page initialization.
2072 pgdat_resize_unlock(pgdat, &flags);
2074 /* Only the highest zone is deferred so find it */
2075 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
2076 zone = pgdat->node_zones + zid;
2077 if (first_init_pfn < zone_end_pfn(zone))
2081 /* If the zone is empty somebody else may have cleared out the zone */
2082 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
2086 max_threads = deferred_page_init_max_threads(cpumask);
2088 while (spfn < epfn) {
2089 unsigned long epfn_align = ALIGN(epfn, PAGES_PER_SECTION);
2090 struct padata_mt_job job = {
2091 .thread_fn = deferred_init_memmap_chunk,
2094 .size = epfn_align - spfn,
2095 .align = PAGES_PER_SECTION,
2096 .min_chunk = PAGES_PER_SECTION,
2097 .max_threads = max_threads,
2100 padata_do_multithreaded(&job);
2101 deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
2105 /* Sanity check that the next zone really is unpopulated */
2106 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
2108 pr_info("node %d deferred pages initialised in %ums\n",
2109 pgdat->node_id, jiffies_to_msecs(jiffies - start));
2111 pgdat_init_report_one_done();
2116 * If this zone has deferred pages, try to grow it by initializing enough
2117 * deferred pages to satisfy the allocation specified by order, rounded up to
2118 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
2119 * of SECTION_SIZE bytes by initializing struct pages in increments of
2120 * PAGES_PER_SECTION * sizeof(struct page) bytes.
2122 * Return true when zone was grown, otherwise return false. We return true even
2123 * when we grow less than requested, to let the caller decide if there are
2124 * enough pages to satisfy the allocation.
2126 * Note: We use noinline because this function is needed only during boot, and
2127 * it is called from a __ref function _deferred_grow_zone. This way we are
2128 * making sure that it is not inlined into permanent text section.
2130 static noinline bool __init
2131 deferred_grow_zone(struct zone *zone, unsigned int order)
2133 unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
2134 pg_data_t *pgdat = zone->zone_pgdat;
2135 unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
2136 unsigned long spfn, epfn, flags;
2137 unsigned long nr_pages = 0;
2140 /* Only the last zone may have deferred pages */
2141 if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))
2144 pgdat_resize_lock(pgdat, &flags);
2147 * If someone grew this zone while we were waiting for spinlock, return
2148 * true, as there might be enough pages already.
2150 if (first_deferred_pfn != pgdat->first_deferred_pfn) {
2151 pgdat_resize_unlock(pgdat, &flags);
2155 /* If the zone is empty somebody else may have cleared out the zone */
2156 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
2157 first_deferred_pfn)) {
2158 pgdat->first_deferred_pfn = ULONG_MAX;
2159 pgdat_resize_unlock(pgdat, &flags);
2160 /* Retry only once. */
2161 return first_deferred_pfn != ULONG_MAX;
2165 * Initialize and free pages in MAX_ORDER sized increments so
2166 * that we can avoid introducing any issues with the buddy
2169 while (spfn < epfn) {
2170 /* update our first deferred PFN for this section */
2171 first_deferred_pfn = spfn;
2173 nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn);
2174 touch_nmi_watchdog();
2176 /* We should only stop along section boundaries */
2177 if ((first_deferred_pfn ^ spfn) < PAGES_PER_SECTION)
2180 /* If our quota has been met we can stop here */
2181 if (nr_pages >= nr_pages_needed)
2185 pgdat->first_deferred_pfn = spfn;
2186 pgdat_resize_unlock(pgdat, &flags);
2188 return nr_pages > 0;
2192 * deferred_grow_zone() is __init, but it is called from
2193 * get_page_from_freelist() during early boot until deferred_pages permanently
2194 * disables this call. This is why we have refdata wrapper to avoid warning,
2195 * and to ensure that the function body gets unloaded.
2198 _deferred_grow_zone(struct zone *zone, unsigned int order)
2200 return deferred_grow_zone(zone, order);
2203 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2205 void __init page_alloc_init_late(void)
2210 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2212 /* There will be num_node_state(N_MEMORY) threads */
2213 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
2214 for_each_node_state(nid, N_MEMORY) {
2215 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
2218 /* Block until all are initialised */
2219 wait_for_completion(&pgdat_init_all_done_comp);
2222 * We initialized the rest of the deferred pages. Permanently disable
2223 * on-demand struct page initialization.
2225 static_branch_disable(&deferred_pages);
2227 /* Reinit limits that are based on free pages after the kernel is up */
2228 files_maxfiles_init();
2233 /* Discard memblock private memory */
2236 for_each_node_state(nid, N_MEMORY)
2237 shuffle_free_memory(NODE_DATA(nid));
2239 for_each_populated_zone(zone)
2240 set_zone_contiguous(zone);
2244 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2245 void __init init_cma_reserved_pageblock(struct page *page)
2247 unsigned i = pageblock_nr_pages;
2248 struct page *p = page;
2251 __ClearPageReserved(p);
2252 set_page_count(p, 0);
2255 set_pageblock_migratetype(page, MIGRATE_CMA);
2257 if (pageblock_order >= MAX_ORDER) {
2258 i = pageblock_nr_pages;
2261 set_page_refcounted(p);
2262 __free_pages(p, MAX_ORDER - 1);
2263 p += MAX_ORDER_NR_PAGES;
2264 } while (i -= MAX_ORDER_NR_PAGES);
2266 set_page_refcounted(page);
2267 __free_pages(page, pageblock_order);
2270 adjust_managed_page_count(page, pageblock_nr_pages);
2271 page_zone(page)->cma_pages += pageblock_nr_pages;
2276 * The order of subdivision here is critical for the IO subsystem.
2277 * Please do not alter this order without good reasons and regression
2278 * testing. Specifically, as large blocks of memory are subdivided,
2279 * the order in which smaller blocks are delivered depends on the order
2280 * they're subdivided in this function. This is the primary factor
2281 * influencing the order in which pages are delivered to the IO
2282 * subsystem according to empirical testing, and this is also justified
2283 * by considering the behavior of a buddy system containing a single
2284 * large block of memory acted on by a series of small allocations.
2285 * This behavior is a critical factor in sglist merging's success.
2289 static inline void expand(struct zone *zone, struct page *page,
2290 int low, int high, int migratetype)
2292 unsigned long size = 1 << high;
2294 while (high > low) {
2297 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
2300 * Mark as guard pages (or page), that will allow to
2301 * merge back to allocator when buddy will be freed.
2302 * Corresponding page table entries will not be touched,
2303 * pages will stay not present in virtual address space
2305 if (set_page_guard(zone, &page[size], high, migratetype))
2308 add_to_free_list(&page[size], zone, high, migratetype);
2309 set_buddy_order(&page[size], high);
2313 static void check_new_page_bad(struct page *page)
2315 if (unlikely(page->flags & __PG_HWPOISON)) {
2316 /* Don't complain about hwpoisoned pages */
2317 page_mapcount_reset(page); /* remove PageBuddy */
2322 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
2326 * This page is about to be returned from the page allocator
2328 static inline int check_new_page(struct page *page)
2330 if (likely(page_expected_state(page,
2331 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
2334 check_new_page_bad(page);
2338 #ifdef CONFIG_DEBUG_VM
2340 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2341 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2342 * also checked when pcp lists are refilled from the free lists.
2344 static inline bool check_pcp_refill(struct page *page)
2346 if (debug_pagealloc_enabled_static())
2347 return check_new_page(page);
2352 static inline bool check_new_pcp(struct page *page)
2354 return check_new_page(page);
2358 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2359 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2360 * enabled, they are also checked when being allocated from the pcp lists.
2362 static inline bool check_pcp_refill(struct page *page)
2364 return check_new_page(page);
2366 static inline bool check_new_pcp(struct page *page)
2368 if (debug_pagealloc_enabled_static())
2369 return check_new_page(page);
2373 #endif /* CONFIG_DEBUG_VM */
2375 static bool check_new_pages(struct page *page, unsigned int order)
2378 for (i = 0; i < (1 << order); i++) {
2379 struct page *p = page + i;
2381 if (unlikely(check_new_page(p)))
2388 inline void post_alloc_hook(struct page *page, unsigned int order,
2391 set_page_private(page, 0);
2392 set_page_refcounted(page);
2394 arch_alloc_page(page, order);
2395 debug_pagealloc_map_pages(page, 1 << order);
2398 * Page unpoisoning must happen before memory initialization.
2399 * Otherwise, the poison pattern will be overwritten for __GFP_ZERO
2400 * allocations and the page unpoisoning code will complain.
2402 kernel_unpoison_pages(page, 1 << order);
2405 * As memory initialization might be integrated into KASAN,
2406 * kasan_alloc_pages and kernel_init_free_pages must be
2407 * kept together to avoid discrepancies in behavior.
2409 if (kasan_has_integrated_init()) {
2410 kasan_alloc_pages(page, order, gfp_flags);
2412 bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags);
2414 kasan_unpoison_pages(page, order, init);
2416 kernel_init_free_pages(page, 1 << order,
2417 gfp_flags & __GFP_ZEROTAGS);
2420 set_page_owner(page, order, gfp_flags);
2423 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
2424 unsigned int alloc_flags)
2426 post_alloc_hook(page, order, gfp_flags);
2428 if (order && (gfp_flags & __GFP_COMP))
2429 prep_compound_page(page, order);
2432 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2433 * allocate the page. The expectation is that the caller is taking
2434 * steps that will free more memory. The caller should avoid the page
2435 * being used for !PFMEMALLOC purposes.
2437 if (alloc_flags & ALLOC_NO_WATERMARKS)
2438 set_page_pfmemalloc(page);
2440 clear_page_pfmemalloc(page);
2444 * Go through the free lists for the given migratetype and remove
2445 * the smallest available page from the freelists
2447 static __always_inline
2448 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
2451 unsigned int current_order;
2452 struct free_area *area;
2455 /* Find a page of the appropriate size in the preferred list */
2456 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
2457 area = &(zone->free_area[current_order]);
2458 page = get_page_from_free_area(area, migratetype);
2461 del_page_from_free_list(page, zone, current_order);
2462 expand(zone, page, order, current_order, migratetype);
2463 set_pcppage_migratetype(page, migratetype);
2472 * This array describes the order lists are fallen back to when
2473 * the free lists for the desirable migrate type are depleted
2475 static int fallbacks[MIGRATE_TYPES][3] = {
2476 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2477 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
2478 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2480 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
2482 #ifdef CONFIG_MEMORY_ISOLATION
2483 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
2488 static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2491 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
2494 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2495 unsigned int order) { return NULL; }
2499 * Move the free pages in a range to the freelist tail of the requested type.
2500 * Note that start_page and end_pages are not aligned on a pageblock
2501 * boundary. If alignment is required, use move_freepages_block()
2503 static int move_freepages(struct zone *zone,
2504 unsigned long start_pfn, unsigned long end_pfn,
2505 int migratetype, int *num_movable)
2510 int pages_moved = 0;
2512 for (pfn = start_pfn; pfn <= end_pfn;) {
2513 page = pfn_to_page(pfn);
2514 if (!PageBuddy(page)) {
2516 * We assume that pages that could be isolated for
2517 * migration are movable. But we don't actually try
2518 * isolating, as that would be expensive.
2521 (PageLRU(page) || __PageMovable(page)))
2527 /* Make sure we are not inadvertently changing nodes */
2528 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
2529 VM_BUG_ON_PAGE(page_zone(page) != zone, page);
2531 order = buddy_order(page);
2532 move_to_free_list(page, zone, order, migratetype);
2534 pages_moved += 1 << order;
2540 int move_freepages_block(struct zone *zone, struct page *page,
2541 int migratetype, int *num_movable)
2543 unsigned long start_pfn, end_pfn, pfn;
2548 pfn = page_to_pfn(page);
2549 start_pfn = pfn & ~(pageblock_nr_pages - 1);
2550 end_pfn = start_pfn + pageblock_nr_pages - 1;
2552 /* Do not cross zone boundaries */
2553 if (!zone_spans_pfn(zone, start_pfn))
2555 if (!zone_spans_pfn(zone, end_pfn))
2558 return move_freepages(zone, start_pfn, end_pfn, migratetype,
2562 static void change_pageblock_range(struct page *pageblock_page,
2563 int start_order, int migratetype)
2565 int nr_pageblocks = 1 << (start_order - pageblock_order);
2567 while (nr_pageblocks--) {
2568 set_pageblock_migratetype(pageblock_page, migratetype);
2569 pageblock_page += pageblock_nr_pages;
2574 * When we are falling back to another migratetype during allocation, try to
2575 * steal extra free pages from the same pageblocks to satisfy further
2576 * allocations, instead of polluting multiple pageblocks.
2578 * If we are stealing a relatively large buddy page, it is likely there will
2579 * be more free pages in the pageblock, so try to steal them all. For
2580 * reclaimable and unmovable allocations, we steal regardless of page size,
2581 * as fragmentation caused by those allocations polluting movable pageblocks
2582 * is worse than movable allocations stealing from unmovable and reclaimable
2585 static bool can_steal_fallback(unsigned int order, int start_mt)
2588 * Leaving this order check is intended, although there is
2589 * relaxed order check in next check. The reason is that
2590 * we can actually steal whole pageblock if this condition met,
2591 * but, below check doesn't guarantee it and that is just heuristic
2592 * so could be changed anytime.
2594 if (order >= pageblock_order)
2597 if (order >= pageblock_order / 2 ||
2598 start_mt == MIGRATE_RECLAIMABLE ||
2599 start_mt == MIGRATE_UNMOVABLE ||
2600 page_group_by_mobility_disabled)
2606 static inline bool boost_watermark(struct zone *zone)
2608 unsigned long max_boost;
2610 if (!watermark_boost_factor)
2613 * Don't bother in zones that are unlikely to produce results.
2614 * On small machines, including kdump capture kernels running
2615 * in a small area, boosting the watermark can cause an out of
2616 * memory situation immediately.
2618 if ((pageblock_nr_pages * 4) > zone_managed_pages(zone))
2621 max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
2622 watermark_boost_factor, 10000);
2625 * high watermark may be uninitialised if fragmentation occurs
2626 * very early in boot so do not boost. We do not fall
2627 * through and boost by pageblock_nr_pages as failing
2628 * allocations that early means that reclaim is not going
2629 * to help and it may even be impossible to reclaim the
2630 * boosted watermark resulting in a hang.
2635 max_boost = max(pageblock_nr_pages, max_boost);
2637 zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages,
2644 * This function implements actual steal behaviour. If order is large enough,
2645 * we can steal whole pageblock. If not, we first move freepages in this
2646 * pageblock to our migratetype and determine how many already-allocated pages
2647 * are there in the pageblock with a compatible migratetype. If at least half
2648 * of pages are free or compatible, we can change migratetype of the pageblock
2649 * itself, so pages freed in the future will be put on the correct free list.
2651 static void steal_suitable_fallback(struct zone *zone, struct page *page,
2652 unsigned int alloc_flags, int start_type, bool whole_block)
2654 unsigned int current_order = buddy_order(page);
2655 int free_pages, movable_pages, alike_pages;
2658 old_block_type = get_pageblock_migratetype(page);
2661 * This can happen due to races and we want to prevent broken
2662 * highatomic accounting.
2664 if (is_migrate_highatomic(old_block_type))
2667 /* Take ownership for orders >= pageblock_order */
2668 if (current_order >= pageblock_order) {
2669 change_pageblock_range(page, current_order, start_type);
2674 * Boost watermarks to increase reclaim pressure to reduce the
2675 * likelihood of future fallbacks. Wake kswapd now as the node
2676 * may be balanced overall and kswapd will not wake naturally.
2678 if (boost_watermark(zone) && (alloc_flags & ALLOC_KSWAPD))
2679 set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
2681 /* We are not allowed to try stealing from the whole block */
2685 free_pages = move_freepages_block(zone, page, start_type,
2688 * Determine how many pages are compatible with our allocation.
2689 * For movable allocation, it's the number of movable pages which
2690 * we just obtained. For other types it's a bit more tricky.
2692 if (start_type == MIGRATE_MOVABLE) {
2693 alike_pages = movable_pages;
2696 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2697 * to MOVABLE pageblock, consider all non-movable pages as
2698 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2699 * vice versa, be conservative since we can't distinguish the
2700 * exact migratetype of non-movable pages.
2702 if (old_block_type == MIGRATE_MOVABLE)
2703 alike_pages = pageblock_nr_pages
2704 - (free_pages + movable_pages);
2709 /* moving whole block can fail due to zone boundary conditions */
2714 * If a sufficient number of pages in the block are either free or of
2715 * comparable migratability as our allocation, claim the whole block.
2717 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2718 page_group_by_mobility_disabled)
2719 set_pageblock_migratetype(page, start_type);
2724 move_to_free_list(page, zone, current_order, start_type);
2728 * Check whether there is a suitable fallback freepage with requested order.
2729 * If only_stealable is true, this function returns fallback_mt only if
2730 * we can steal other freepages all together. This would help to reduce
2731 * fragmentation due to mixed migratetype pages in one pageblock.
2733 int find_suitable_fallback(struct free_area *area, unsigned int order,
2734 int migratetype, bool only_stealable, bool *can_steal)
2739 if (area->nr_free == 0)
2744 fallback_mt = fallbacks[migratetype][i];
2745 if (fallback_mt == MIGRATE_TYPES)
2748 if (free_area_empty(area, fallback_mt))
2751 if (can_steal_fallback(order, migratetype))
2754 if (!only_stealable)
2765 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2766 * there are no empty page blocks that contain a page with a suitable order
2768 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2769 unsigned int alloc_order)
2772 unsigned long max_managed, flags;
2775 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2776 * Check is race-prone but harmless.
2778 max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;
2779 if (zone->nr_reserved_highatomic >= max_managed)
2782 spin_lock_irqsave(&zone->lock, flags);
2784 /* Recheck the nr_reserved_highatomic limit under the lock */
2785 if (zone->nr_reserved_highatomic >= max_managed)
2789 mt = get_pageblock_migratetype(page);
2790 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2791 && !is_migrate_cma(mt)) {
2792 zone->nr_reserved_highatomic += pageblock_nr_pages;
2793 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2794 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2798 spin_unlock_irqrestore(&zone->lock, flags);
2802 * Used when an allocation is about to fail under memory pressure. This
2803 * potentially hurts the reliability of high-order allocations when under
2804 * intense memory pressure but failed atomic allocations should be easier
2805 * to recover from than an OOM.
2807 * If @force is true, try to unreserve a pageblock even though highatomic
2808 * pageblock is exhausted.
2810 static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2813 struct zonelist *zonelist = ac->zonelist;
2814 unsigned long flags;
2821 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
2824 * Preserve at least one pageblock unless memory pressure
2827 if (!force && zone->nr_reserved_highatomic <=
2831 spin_lock_irqsave(&zone->lock, flags);
2832 for (order = 0; order < MAX_ORDER; order++) {
2833 struct free_area *area = &(zone->free_area[order]);
2835 page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
2840 * In page freeing path, migratetype change is racy so
2841 * we can counter several free pages in a pageblock
2842 * in this loop although we changed the pageblock type
2843 * from highatomic to ac->migratetype. So we should
2844 * adjust the count once.
2846 if (is_migrate_highatomic_page(page)) {
2848 * It should never happen but changes to
2849 * locking could inadvertently allow a per-cpu
2850 * drain to add pages to MIGRATE_HIGHATOMIC
2851 * while unreserving so be safe and watch for
2854 zone->nr_reserved_highatomic -= min(
2856 zone->nr_reserved_highatomic);
2860 * Convert to ac->migratetype and avoid the normal
2861 * pageblock stealing heuristics. Minimally, the caller
2862 * is doing the work and needs the pages. More
2863 * importantly, if the block was always converted to
2864 * MIGRATE_UNMOVABLE or another type then the number
2865 * of pageblocks that cannot be completely freed
2868 set_pageblock_migratetype(page, ac->migratetype);
2869 ret = move_freepages_block(zone, page, ac->migratetype,
2872 spin_unlock_irqrestore(&zone->lock, flags);
2876 spin_unlock_irqrestore(&zone->lock, flags);
2883 * Try finding a free buddy page on the fallback list and put it on the free
2884 * list of requested migratetype, possibly along with other pages from the same
2885 * block, depending on fragmentation avoidance heuristics. Returns true if
2886 * fallback was found so that __rmqueue_smallest() can grab it.
2888 * The use of signed ints for order and current_order is a deliberate
2889 * deviation from the rest of this file, to make the for loop
2890 * condition simpler.
2892 static __always_inline bool
2893 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
2894 unsigned int alloc_flags)
2896 struct free_area *area;
2898 int min_order = order;
2904 * Do not steal pages from freelists belonging to other pageblocks
2905 * i.e. orders < pageblock_order. If there are no local zones free,
2906 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2908 if (alloc_flags & ALLOC_NOFRAGMENT)
2909 min_order = pageblock_order;
2912 * Find the largest available free page in the other list. This roughly
2913 * approximates finding the pageblock with the most free pages, which
2914 * would be too costly to do exactly.
2916 for (current_order = MAX_ORDER - 1; current_order >= min_order;
2918 area = &(zone->free_area[current_order]);
2919 fallback_mt = find_suitable_fallback(area, current_order,
2920 start_migratetype, false, &can_steal);
2921 if (fallback_mt == -1)
2925 * We cannot steal all free pages from the pageblock and the
2926 * requested migratetype is movable. In that case it's better to
2927 * steal and split the smallest available page instead of the
2928 * largest available page, because even if the next movable
2929 * allocation falls back into a different pageblock than this
2930 * one, it won't cause permanent fragmentation.
2932 if (!can_steal && start_migratetype == MIGRATE_MOVABLE
2933 && current_order > order)
2942 for (current_order = order; current_order < MAX_ORDER;
2944 area = &(zone->free_area[current_order]);
2945 fallback_mt = find_suitable_fallback(area, current_order,
2946 start_migratetype, false, &can_steal);
2947 if (fallback_mt != -1)
2952 * This should not happen - we already found a suitable fallback
2953 * when looking for the largest page.
2955 VM_BUG_ON(current_order == MAX_ORDER);
2958 page = get_page_from_free_area(area, fallback_mt);
2960 steal_suitable_fallback(zone, page, alloc_flags, start_migratetype,
2963 trace_mm_page_alloc_extfrag(page, order, current_order,
2964 start_migratetype, fallback_mt);
2971 * Do the hard work of removing an element from the buddy allocator.
2972 * Call me with the zone->lock already held.
2974 static __always_inline struct page *
2975 __rmqueue(struct zone *zone, unsigned int order, int migratetype,
2976 unsigned int alloc_flags)
2980 if (IS_ENABLED(CONFIG_CMA)) {
2982 * Balance movable allocations between regular and CMA areas by
2983 * allocating from CMA when over half of the zone's free memory
2984 * is in the CMA area.
2986 if (alloc_flags & ALLOC_CMA &&
2987 zone_page_state(zone, NR_FREE_CMA_PAGES) >
2988 zone_page_state(zone, NR_FREE_PAGES) / 2) {
2989 page = __rmqueue_cma_fallback(zone, order);
2995 page = __rmqueue_smallest(zone, order, migratetype);
2996 if (unlikely(!page)) {
2997 if (alloc_flags & ALLOC_CMA)
2998 page = __rmqueue_cma_fallback(zone, order);
3000 if (!page && __rmqueue_fallback(zone, order, migratetype,
3006 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3011 * Obtain a specified number of elements from the buddy allocator, all under
3012 * a single hold of the lock, for efficiency. Add them to the supplied list.
3013 * Returns the number of new pages which were placed at *list.
3015 static int rmqueue_bulk(struct zone *zone, unsigned int order,
3016 unsigned long count, struct list_head *list,
3017 int migratetype, unsigned int alloc_flags)
3019 int i, allocated = 0;
3022 * local_lock_irq held so equivalent to spin_lock_irqsave for
3023 * both PREEMPT_RT and non-PREEMPT_RT configurations.
3025 spin_lock(&zone->lock);
3026 for (i = 0; i < count; ++i) {
3027 struct page *page = __rmqueue(zone, order, migratetype,
3029 if (unlikely(page == NULL))
3032 if (unlikely(check_pcp_refill(page)))
3036 * Split buddy pages returned by expand() are received here in
3037 * physical page order. The page is added to the tail of
3038 * caller's list. From the callers perspective, the linked list
3039 * is ordered by page number under some conditions. This is
3040 * useful for IO devices that can forward direction from the
3041 * head, thus also in the physical page order. This is useful
3042 * for IO devices that can merge IO requests if the physical
3043 * pages are ordered properly.
3045 list_add_tail(&page->lru, list);
3047 if (is_migrate_cma(get_pcppage_migratetype(page)))
3048 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
3053 * i pages were removed from the buddy list even if some leak due
3054 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
3055 * on i. Do not confuse with 'allocated' which is the number of
3056 * pages added to the pcp list.
3058 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
3059 spin_unlock(&zone->lock);
3065 * Called from the vmstat counter updater to drain pagesets of this
3066 * currently executing processor on remote nodes after they have
3069 * Note that this function must be called with the thread pinned to
3070 * a single processor.
3072 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
3074 unsigned long flags;
3075 int to_drain, batch;
3077 local_lock_irqsave(&pagesets.lock, flags);
3078 batch = READ_ONCE(pcp->batch);
3079 to_drain = min(pcp->count, batch);
3081 free_pcppages_bulk(zone, to_drain, pcp);
3082 local_unlock_irqrestore(&pagesets.lock, flags);
3087 * Drain pcplists of the indicated processor and zone.
3089 * The processor must either be the current processor and the
3090 * thread pinned to the current processor or a processor that
3093 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
3095 unsigned long flags;
3096 struct per_cpu_pages *pcp;
3098 local_lock_irqsave(&pagesets.lock, flags);
3100 pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
3102 free_pcppages_bulk(zone, pcp->count, pcp);
3104 local_unlock_irqrestore(&pagesets.lock, flags);
3108 * Drain pcplists of all zones on the indicated processor.
3110 * The processor must either be the current processor and the
3111 * thread pinned to the current processor or a processor that
3114 static void drain_pages(unsigned int cpu)
3118 for_each_populated_zone(zone) {
3119 drain_pages_zone(cpu, zone);
3124 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
3126 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
3127 * the single zone's pages.
3129 void drain_local_pages(struct zone *zone)
3131 int cpu = smp_processor_id();
3134 drain_pages_zone(cpu, zone);
3139 static void drain_local_pages_wq(struct work_struct *work)
3141 struct pcpu_drain *drain;
3143 drain = container_of(work, struct pcpu_drain, work);
3146 * drain_all_pages doesn't use proper cpu hotplug protection so
3147 * we can race with cpu offline when the WQ can move this from
3148 * a cpu pinned worker to an unbound one. We can operate on a different
3149 * cpu which is alright but we also have to make sure to not move to
3153 drain_local_pages(drain->zone);
3158 * The implementation of drain_all_pages(), exposing an extra parameter to
3159 * drain on all cpus.
3161 * drain_all_pages() is optimized to only execute on cpus where pcplists are
3162 * not empty. The check for non-emptiness can however race with a free to
3163 * pcplist that has not yet increased the pcp->count from 0 to 1. Callers
3164 * that need the guarantee that every CPU has drained can disable the
3165 * optimizing racy check.
3167 static void __drain_all_pages(struct zone *zone, bool force_all_cpus)
3172 * Allocate in the BSS so we won't require allocation in
3173 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
3175 static cpumask_t cpus_with_pcps;
3178 * Make sure nobody triggers this path before mm_percpu_wq is fully
3181 if (WARN_ON_ONCE(!mm_percpu_wq))
3185 * Do not drain if one is already in progress unless it's specific to
3186 * a zone. Such callers are primarily CMA and memory hotplug and need
3187 * the drain to be complete when the call returns.
3189 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
3192 mutex_lock(&pcpu_drain_mutex);
3196 * We don't care about racing with CPU hotplug event
3197 * as offline notification will cause the notified
3198 * cpu to drain that CPU pcps and on_each_cpu_mask
3199 * disables preemption as part of its processing
3201 for_each_online_cpu(cpu) {
3202 struct per_cpu_pages *pcp;
3204 bool has_pcps = false;
3206 if (force_all_cpus) {
3208 * The pcp.count check is racy, some callers need a
3209 * guarantee that no cpu is missed.
3213 pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
3217 for_each_populated_zone(z) {
3218 pcp = per_cpu_ptr(z->per_cpu_pageset, cpu);
3227 cpumask_set_cpu(cpu, &cpus_with_pcps);
3229 cpumask_clear_cpu(cpu, &cpus_with_pcps);
3232 for_each_cpu(cpu, &cpus_with_pcps) {
3233 struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu);
3236 INIT_WORK(&drain->work, drain_local_pages_wq);
3237 queue_work_on(cpu, mm_percpu_wq, &drain->work);
3239 for_each_cpu(cpu, &cpus_with_pcps)
3240 flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work);
3242 mutex_unlock(&pcpu_drain_mutex);
3246 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
3248 * When zone parameter is non-NULL, spill just the single zone's pages.
3250 * Note that this can be extremely slow as the draining happens in a workqueue.
3252 void drain_all_pages(struct zone *zone)
3254 __drain_all_pages(zone, false);
3257 #ifdef CONFIG_HIBERNATION
3260 * Touch the watchdog for every WD_PAGE_COUNT pages.
3262 #define WD_PAGE_COUNT (128*1024)
3264 void mark_free_pages(struct zone *zone)
3266 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
3267 unsigned long flags;
3268 unsigned int order, t;
3271 if (zone_is_empty(zone))
3274 spin_lock_irqsave(&zone->lock, flags);
3276 max_zone_pfn = zone_end_pfn(zone);
3277 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
3278 if (pfn_valid(pfn)) {
3279 page = pfn_to_page(pfn);
3281 if (!--page_count) {
3282 touch_nmi_watchdog();
3283 page_count = WD_PAGE_COUNT;
3286 if (page_zone(page) != zone)
3289 if (!swsusp_page_is_forbidden(page))
3290 swsusp_unset_page_free(page);
3293 for_each_migratetype_order(order, t) {
3294 list_for_each_entry(page,
3295 &zone->free_area[order].free_list[t], lru) {
3298 pfn = page_to_pfn(page);
3299 for (i = 0; i < (1UL << order); i++) {
3300 if (!--page_count) {
3301 touch_nmi_watchdog();
3302 page_count = WD_PAGE_COUNT;
3304 swsusp_set_page_free(pfn_to_page(pfn + i));
3308 spin_unlock_irqrestore(&zone->lock, flags);
3310 #endif /* CONFIG_PM */
3312 static bool free_unref_page_prepare(struct page *page, unsigned long pfn,
3317 if (!free_pcp_prepare(page, order))
3320 migratetype = get_pfnblock_migratetype(page, pfn);
3321 set_pcppage_migratetype(page, migratetype);
3325 static int nr_pcp_free(struct per_cpu_pages *pcp, int high, int batch)
3327 int min_nr_free, max_nr_free;
3329 /* Check for PCP disabled or boot pageset */
3330 if (unlikely(high < batch))
3333 /* Leave at least pcp->batch pages on the list */
3334 min_nr_free = batch;
3335 max_nr_free = high - batch;
3338 * Double the number of pages freed each time there is subsequent
3339 * freeing of pages without any allocation.
3341 batch <<= pcp->free_factor;
3342 if (batch < max_nr_free)
3344 batch = clamp(batch, min_nr_free, max_nr_free);
3349 static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone)
3351 int high = READ_ONCE(pcp->high);
3353 if (unlikely(!high))
3356 if (!test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags))
3360 * If reclaim is active, limit the number of pages that can be
3361 * stored on pcp lists
3363 return min(READ_ONCE(pcp->batch) << 2, high);
3366 static void free_unref_page_commit(struct page *page, unsigned long pfn,
3367 int migratetype, unsigned int order)
3369 struct zone *zone = page_zone(page);
3370 struct per_cpu_pages *pcp;
3374 __count_vm_event(PGFREE);
3375 pcp = this_cpu_ptr(zone->per_cpu_pageset);
3376 pindex = order_to_pindex(migratetype, order);
3377 list_add(&page->lru, &pcp->lists[pindex]);
3378 pcp->count += 1 << order;
3379 high = nr_pcp_high(pcp, zone);
3380 if (pcp->count >= high) {
3381 int batch = READ_ONCE(pcp->batch);
3383 free_pcppages_bulk(zone, nr_pcp_free(pcp, high, batch), pcp);
3390 void free_unref_page(struct page *page, unsigned int order)
3392 unsigned long flags;
3393 unsigned long pfn = page_to_pfn(page);
3396 if (!free_unref_page_prepare(page, pfn, order))
3400 * We only track unmovable, reclaimable and movable on pcp lists.
3401 * Place ISOLATE pages on the isolated list because they are being
3402 * offlined but treat HIGHATOMIC as movable pages so we can get those
3403 * areas back if necessary. Otherwise, we may have to free
3404 * excessively into the page allocator
3406 migratetype = get_pcppage_migratetype(page);
3407 if (unlikely(migratetype >= MIGRATE_PCPTYPES)) {
3408 if (unlikely(is_migrate_isolate(migratetype))) {
3409 free_one_page(page_zone(page), page, pfn, order, migratetype, FPI_NONE);
3412 migratetype = MIGRATE_MOVABLE;
3415 local_lock_irqsave(&pagesets.lock, flags);
3416 free_unref_page_commit(page, pfn, migratetype, order);
3417 local_unlock_irqrestore(&pagesets.lock, flags);
3421 * Free a list of 0-order pages
3423 void free_unref_page_list(struct list_head *list)
3425 struct page *page, *next;
3426 unsigned long flags, pfn;
3427 int batch_count = 0;
3430 /* Prepare pages for freeing */
3431 list_for_each_entry_safe(page, next, list, lru) {
3432 pfn = page_to_pfn(page);
3433 if (!free_unref_page_prepare(page, pfn, 0)) {
3434 list_del(&page->lru);
3439 * Free isolated pages directly to the allocator, see
3440 * comment in free_unref_page.
3442 migratetype = get_pcppage_migratetype(page);
3443 if (unlikely(is_migrate_isolate(migratetype))) {
3444 list_del(&page->lru);
3445 free_one_page(page_zone(page), page, pfn, 0, migratetype, FPI_NONE);
3449 set_page_private(page, pfn);
3452 local_lock_irqsave(&pagesets.lock, flags);
3453 list_for_each_entry_safe(page, next, list, lru) {
3454 pfn = page_private(page);
3455 set_page_private(page, 0);
3458 * Non-isolated types over MIGRATE_PCPTYPES get added
3459 * to the MIGRATE_MOVABLE pcp list.
3461 migratetype = get_pcppage_migratetype(page);
3462 if (unlikely(migratetype >= MIGRATE_PCPTYPES))
3463 migratetype = MIGRATE_MOVABLE;
3465 trace_mm_page_free_batched(page);
3466 free_unref_page_commit(page, pfn, migratetype, 0);
3469 * Guard against excessive IRQ disabled times when we get
3470 * a large list of pages to free.
3472 if (++batch_count == SWAP_CLUSTER_MAX) {
3473 local_unlock_irqrestore(&pagesets.lock, flags);
3475 local_lock_irqsave(&pagesets.lock, flags);
3478 local_unlock_irqrestore(&pagesets.lock, flags);
3482 * split_page takes a non-compound higher-order page, and splits it into
3483 * n (1<<order) sub-pages: page[0..n]
3484 * Each sub-page must be freed individually.
3486 * Note: this is probably too low level an operation for use in drivers.
3487 * Please consult with lkml before using this in your driver.
3489 void split_page(struct page *page, unsigned int order)
3493 VM_BUG_ON_PAGE(PageCompound(page), page);
3494 VM_BUG_ON_PAGE(!page_count(page), page);
3496 for (i = 1; i < (1 << order); i++)
3497 set_page_refcounted(page + i);
3498 split_page_owner(page, 1 << order);
3499 split_page_memcg(page, 1 << order);
3501 EXPORT_SYMBOL_GPL(split_page);
3503 int __isolate_free_page(struct page *page, unsigned int order)
3505 unsigned long watermark;
3509 BUG_ON(!PageBuddy(page));
3511 zone = page_zone(page);
3512 mt = get_pageblock_migratetype(page);
3514 if (!is_migrate_isolate(mt)) {
3516 * Obey watermarks as if the page was being allocated. We can
3517 * emulate a high-order watermark check with a raised order-0
3518 * watermark, because we already know our high-order page
3521 watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
3522 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
3525 __mod_zone_freepage_state(zone, -(1UL << order), mt);
3528 /* Remove page from free list */
3530 del_page_from_free_list(page, zone, order);
3533 * Set the pageblock if the isolated page is at least half of a
3536 if (order >= pageblock_order - 1) {
3537 struct page *endpage = page + (1 << order) - 1;
3538 for (; page < endpage; page += pageblock_nr_pages) {
3539 int mt = get_pageblock_migratetype(page);
3540 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
3541 && !is_migrate_highatomic(mt))
3542 set_pageblock_migratetype(page,
3548 return 1UL << order;
3552 * __putback_isolated_page - Return a now-isolated page back where we got it
3553 * @page: Page that was isolated
3554 * @order: Order of the isolated page
3555 * @mt: The page's pageblock's migratetype
3557 * This function is meant to return a page pulled from the free lists via
3558 * __isolate_free_page back to the free lists they were pulled from.
3560 void __putback_isolated_page(struct page *page, unsigned int order, int mt)
3562 struct zone *zone = page_zone(page);
3564 /* zone lock should be held when this function is called */
3565 lockdep_assert_held(&zone->lock);
3567 /* Return isolated page to tail of freelist. */
3568 __free_one_page(page, page_to_pfn(page), zone, order, mt,
3569 FPI_SKIP_REPORT_NOTIFY | FPI_TO_TAIL);
3573 * Update NUMA hit/miss statistics
3575 * Must be called with interrupts disabled.
3577 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
3581 enum numa_stat_item local_stat = NUMA_LOCAL;
3583 /* skip numa counters update if numa stats is disabled */
3584 if (!static_branch_likely(&vm_numa_stat_key))
3587 if (zone_to_nid(z) != numa_node_id())
3588 local_stat = NUMA_OTHER;
3590 if (zone_to_nid(z) == zone_to_nid(preferred_zone))
3591 __count_numa_events(z, NUMA_HIT, nr_account);
3593 __count_numa_events(z, NUMA_MISS, nr_account);
3594 __count_numa_events(preferred_zone, NUMA_FOREIGN, nr_account);
3596 __count_numa_events(z, local_stat, nr_account);
3600 /* Remove page from the per-cpu list, caller must protect the list */
3602 struct page *__rmqueue_pcplist(struct zone *zone, unsigned int order,
3604 unsigned int alloc_flags,
3605 struct per_cpu_pages *pcp,
3606 struct list_head *list)
3611 if (list_empty(list)) {
3612 int batch = READ_ONCE(pcp->batch);
3616 * Scale batch relative to order if batch implies
3617 * free pages can be stored on the PCP. Batch can
3618 * be 1 for small zones or for boot pagesets which
3619 * should never store free pages as the pages may
3620 * belong to arbitrary zones.
3623 batch = max(batch >> order, 2);
3624 alloced = rmqueue_bulk(zone, order,
3626 migratetype, alloc_flags);
3628 pcp->count += alloced << order;
3629 if (unlikely(list_empty(list)))
3633 page = list_first_entry(list, struct page, lru);
3634 list_del(&page->lru);
3635 pcp->count -= 1 << order;
3636 } while (check_new_pcp(page));
3641 /* Lock and remove page from the per-cpu list */
3642 static struct page *rmqueue_pcplist(struct zone *preferred_zone,
3643 struct zone *zone, unsigned int order,
3644 gfp_t gfp_flags, int migratetype,
3645 unsigned int alloc_flags)
3647 struct per_cpu_pages *pcp;
3648 struct list_head *list;
3650 unsigned long flags;
3652 local_lock_irqsave(&pagesets.lock, flags);
3655 * On allocation, reduce the number of pages that are batch freed.
3656 * See nr_pcp_free() where free_factor is increased for subsequent
3659 pcp = this_cpu_ptr(zone->per_cpu_pageset);
3660 pcp->free_factor >>= 1;
3661 list = &pcp->lists[order_to_pindex(migratetype, order)];
3662 page = __rmqueue_pcplist(zone, order, migratetype, alloc_flags, pcp, list);
3663 local_unlock_irqrestore(&pagesets.lock, flags);
3665 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1);
3666 zone_statistics(preferred_zone, zone, 1);
3672 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3675 struct page *rmqueue(struct zone *preferred_zone,
3676 struct zone *zone, unsigned int order,
3677 gfp_t gfp_flags, unsigned int alloc_flags,
3680 unsigned long flags;
3683 if (likely(pcp_allowed_order(order))) {
3685 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3686 * we need to skip it when CMA area isn't allowed.
3688 if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA ||
3689 migratetype != MIGRATE_MOVABLE) {
3690 page = rmqueue_pcplist(preferred_zone, zone, order,
3691 gfp_flags, migratetype, alloc_flags);
3697 * We most definitely don't want callers attempting to
3698 * allocate greater than order-1 page units with __GFP_NOFAIL.
3700 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
3701 spin_lock_irqsave(&zone->lock, flags);
3706 * order-0 request can reach here when the pcplist is skipped
3707 * due to non-CMA allocation context. HIGHATOMIC area is
3708 * reserved for high-order atomic allocation, so order-0
3709 * request should skip it.
3711 if (order > 0 && alloc_flags & ALLOC_HARDER) {
3712 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
3714 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3717 page = __rmqueue(zone, order, migratetype, alloc_flags);
3718 } while (page && check_new_pages(page, order));
3722 __mod_zone_freepage_state(zone, -(1 << order),
3723 get_pcppage_migratetype(page));
3724 spin_unlock_irqrestore(&zone->lock, flags);
3726 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
3727 zone_statistics(preferred_zone, zone, 1);
3730 /* Separate test+clear to avoid unnecessary atomics */
3731 if (test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags)) {
3732 clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
3733 wakeup_kswapd(zone, 0, 0, zone_idx(zone));
3736 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
3740 spin_unlock_irqrestore(&zone->lock, flags);
3744 #ifdef CONFIG_FAIL_PAGE_ALLOC
3747 struct fault_attr attr;
3749 bool ignore_gfp_highmem;
3750 bool ignore_gfp_reclaim;
3752 } fail_page_alloc = {
3753 .attr = FAULT_ATTR_INITIALIZER,
3754 .ignore_gfp_reclaim = true,
3755 .ignore_gfp_highmem = true,
3759 static int __init setup_fail_page_alloc(char *str)
3761 return setup_fault_attr(&fail_page_alloc.attr, str);
3763 __setup("fail_page_alloc=", setup_fail_page_alloc);
3765 static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3767 if (order < fail_page_alloc.min_order)
3769 if (gfp_mask & __GFP_NOFAIL)
3771 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
3773 if (fail_page_alloc.ignore_gfp_reclaim &&
3774 (gfp_mask & __GFP_DIRECT_RECLAIM))
3777 return should_fail(&fail_page_alloc.attr, 1 << order);
3780 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3782 static int __init fail_page_alloc_debugfs(void)
3784 umode_t mode = S_IFREG | 0600;
3787 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
3788 &fail_page_alloc.attr);
3790 debugfs_create_bool("ignore-gfp-wait", mode, dir,
3791 &fail_page_alloc.ignore_gfp_reclaim);
3792 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
3793 &fail_page_alloc.ignore_gfp_highmem);
3794 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);
3799 late_initcall(fail_page_alloc_debugfs);
3801 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3803 #else /* CONFIG_FAIL_PAGE_ALLOC */
3805 static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3810 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3812 noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3814 return __should_fail_alloc_page(gfp_mask, order);
3816 ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
3818 static inline long __zone_watermark_unusable_free(struct zone *z,
3819 unsigned int order, unsigned int alloc_flags)
3821 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3822 long unusable_free = (1 << order) - 1;
3825 * If the caller does not have rights to ALLOC_HARDER then subtract
3826 * the high-atomic reserves. This will over-estimate the size of the
3827 * atomic reserve but it avoids a search.
3829 if (likely(!alloc_harder))
3830 unusable_free += z->nr_reserved_highatomic;
3833 /* If allocation can't use CMA areas don't use free CMA pages */
3834 if (!(alloc_flags & ALLOC_CMA))
3835 unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES);
3838 return unusable_free;
3842 * Return true if free base pages are above 'mark'. For high-order checks it
3843 * will return true of the order-0 watermark is reached and there is at least
3844 * one free page of a suitable size. Checking now avoids taking the zone lock
3845 * to check in the allocation paths if no pages are free.
3847 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3848 int highest_zoneidx, unsigned int alloc_flags,
3853 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3855 /* free_pages may go negative - that's OK */
3856 free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags);
3858 if (alloc_flags & ALLOC_HIGH)
3861 if (unlikely(alloc_harder)) {
3863 * OOM victims can try even harder than normal ALLOC_HARDER
3864 * users on the grounds that it's definitely going to be in
3865 * the exit path shortly and free memory. Any allocation it
3866 * makes during the free path will be small and short-lived.
3868 if (alloc_flags & ALLOC_OOM)
3875 * Check watermarks for an order-0 allocation request. If these
3876 * are not met, then a high-order request also cannot go ahead
3877 * even if a suitable page happened to be free.
3879 if (free_pages <= min + z->lowmem_reserve[highest_zoneidx])
3882 /* If this is an order-0 request then the watermark is fine */
3886 /* For a high-order request, check at least one suitable page is free */
3887 for (o = order; o < MAX_ORDER; o++) {
3888 struct free_area *area = &z->free_area[o];
3894 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
3895 if (!free_area_empty(area, mt))
3900 if ((alloc_flags & ALLOC_CMA) &&
3901 !free_area_empty(area, MIGRATE_CMA)) {
3905 if (alloc_harder && !free_area_empty(area, MIGRATE_HIGHATOMIC))
3911 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3912 int highest_zoneidx, unsigned int alloc_flags)
3914 return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
3915 zone_page_state(z, NR_FREE_PAGES));
3918 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
3919 unsigned long mark, int highest_zoneidx,
3920 unsigned int alloc_flags, gfp_t gfp_mask)
3924 free_pages = zone_page_state(z, NR_FREE_PAGES);
3927 * Fast check for order-0 only. If this fails then the reserves
3928 * need to be calculated.
3933 fast_free = free_pages;
3934 fast_free -= __zone_watermark_unusable_free(z, 0, alloc_flags);
3935 if (fast_free > mark + z->lowmem_reserve[highest_zoneidx])
3939 if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
3943 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3944 * when checking the min watermark. The min watermark is the
3945 * point where boosting is ignored so that kswapd is woken up
3946 * when below the low watermark.
3948 if (unlikely(!order && (gfp_mask & __GFP_ATOMIC) && z->watermark_boost
3949 && ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) {
3950 mark = z->_watermark[WMARK_MIN];
3951 return __zone_watermark_ok(z, order, mark, highest_zoneidx,
3952 alloc_flags, free_pages);
3958 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
3959 unsigned long mark, int highest_zoneidx)
3961 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3963 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
3964 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
3966 return __zone_watermark_ok(z, order, mark, highest_zoneidx, 0,
3971 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3973 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3974 node_reclaim_distance;
3976 #else /* CONFIG_NUMA */
3977 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3981 #endif /* CONFIG_NUMA */
3984 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3985 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3986 * premature use of a lower zone may cause lowmem pressure problems that
3987 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3988 * probably too small. It only makes sense to spread allocations to avoid
3989 * fragmentation between the Normal and DMA32 zones.
3991 static inline unsigned int
3992 alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
3994 unsigned int alloc_flags;
3997 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4000 alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM);
4002 #ifdef CONFIG_ZONE_DMA32
4006 if (zone_idx(zone) != ZONE_NORMAL)
4010 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
4011 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
4012 * on UMA that if Normal is populated then so is DMA32.
4014 BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1);
4015 if (nr_online_nodes > 1 && !populated_zone(--zone))
4018 alloc_flags |= ALLOC_NOFRAGMENT;
4019 #endif /* CONFIG_ZONE_DMA32 */
4023 /* Must be called after current_gfp_context() which can change gfp_mask */
4024 static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask,
4025 unsigned int alloc_flags)
4028 if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
4029 alloc_flags |= ALLOC_CMA;
4035 * get_page_from_freelist goes through the zonelist trying to allocate
4038 static struct page *
4039 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
4040 const struct alloc_context *ac)
4044 struct pglist_data *last_pgdat_dirty_limit = NULL;
4049 * Scan zonelist, looking for a zone with enough free.
4050 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
4052 no_fallback = alloc_flags & ALLOC_NOFRAGMENT;
4053 z = ac->preferred_zoneref;
4054 for_next_zone_zonelist_nodemask(zone, z, ac->highest_zoneidx,
4059 if (cpusets_enabled() &&
4060 (alloc_flags & ALLOC_CPUSET) &&
4061 !__cpuset_zone_allowed(zone, gfp_mask))
4064 * When allocating a page cache page for writing, we
4065 * want to get it from a node that is within its dirty
4066 * limit, such that no single node holds more than its
4067 * proportional share of globally allowed dirty pages.
4068 * The dirty limits take into account the node's
4069 * lowmem reserves and high watermark so that kswapd
4070 * should be able to balance it without having to
4071 * write pages from its LRU list.
4073 * XXX: For now, allow allocations to potentially
4074 * exceed the per-node dirty limit in the slowpath
4075 * (spread_dirty_pages unset) before going into reclaim,
4076 * which is important when on a NUMA setup the allowed
4077 * nodes are together not big enough to reach the
4078 * global limit. The proper fix for these situations
4079 * will require awareness of nodes in the
4080 * dirty-throttling and the flusher threads.
4082 if (ac->spread_dirty_pages) {
4083 if (last_pgdat_dirty_limit == zone->zone_pgdat)
4086 if (!node_dirty_ok(zone->zone_pgdat)) {
4087 last_pgdat_dirty_limit = zone->zone_pgdat;
4092 if (no_fallback && nr_online_nodes > 1 &&
4093 zone != ac->preferred_zoneref->zone) {
4097 * If moving to a remote node, retry but allow
4098 * fragmenting fallbacks. Locality is more important
4099 * than fragmentation avoidance.
4101 local_nid = zone_to_nid(ac->preferred_zoneref->zone);
4102 if (zone_to_nid(zone) != local_nid) {
4103 alloc_flags &= ~ALLOC_NOFRAGMENT;
4108 mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
4109 if (!zone_watermark_fast(zone, order, mark,
4110 ac->highest_zoneidx, alloc_flags,
4114 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
4116 * Watermark failed for this zone, but see if we can
4117 * grow this zone if it contains deferred pages.
4119 if (static_branch_unlikely(&deferred_pages)) {
4120 if (_deferred_grow_zone(zone, order))
4124 /* Checked here to keep the fast path fast */
4125 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
4126 if (alloc_flags & ALLOC_NO_WATERMARKS)
4129 if (!node_reclaim_enabled() ||
4130 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
4133 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
4135 case NODE_RECLAIM_NOSCAN:
4138 case NODE_RECLAIM_FULL:
4139 /* scanned but unreclaimable */
4142 /* did we reclaim enough */
4143 if (zone_watermark_ok(zone, order, mark,
4144 ac->highest_zoneidx, alloc_flags))
4152 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
4153 gfp_mask, alloc_flags, ac->migratetype);
4155 prep_new_page(page, order, gfp_mask, alloc_flags);
4158 * If this is a high-order atomic allocation then check
4159 * if the pageblock should be reserved for the future
4161 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
4162 reserve_highatomic_pageblock(page, zone, order);
4166 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
4167 /* Try again if zone has deferred pages */
4168 if (static_branch_unlikely(&deferred_pages)) {
4169 if (_deferred_grow_zone(zone, order))
4177 * It's possible on a UMA machine to get through all zones that are
4178 * fragmented. If avoiding fragmentation, reset and try again.
4181 alloc_flags &= ~ALLOC_NOFRAGMENT;
4188 static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
4190 unsigned int filter = SHOW_MEM_FILTER_NODES;
4193 * This documents exceptions given to allocations in certain
4194 * contexts that are allowed to allocate outside current's set
4197 if (!(gfp_mask & __GFP_NOMEMALLOC))
4198 if (tsk_is_oom_victim(current) ||
4199 (current->flags & (PF_MEMALLOC | PF_EXITING)))
4200 filter &= ~SHOW_MEM_FILTER_NODES;
4201 if (!in_task() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
4202 filter &= ~SHOW_MEM_FILTER_NODES;
4204 show_mem(filter, nodemask);
4207 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
4209 struct va_format vaf;
4211 static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1);
4213 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
4216 va_start(args, fmt);
4219 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
4220 current->comm, &vaf, gfp_mask, &gfp_mask,
4221 nodemask_pr_args(nodemask));
4224 cpuset_print_current_mems_allowed();
4227 warn_alloc_show_mem(gfp_mask, nodemask);
4230 static inline struct page *
4231 __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
4232 unsigned int alloc_flags,
4233 const struct alloc_context *ac)
4237 page = get_page_from_freelist(gfp_mask, order,
4238 alloc_flags|ALLOC_CPUSET, ac);
4240 * fallback to ignore cpuset restriction if our nodes
4244 page = get_page_from_freelist(gfp_mask, order,
4250 static inline struct page *
4251 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
4252 const struct alloc_context *ac, unsigned long *did_some_progress)
4254 struct oom_control oc = {
4255 .zonelist = ac->zonelist,
4256 .nodemask = ac->nodemask,
4258 .gfp_mask = gfp_mask,
4263 *did_some_progress = 0;
4266 * Acquire the oom lock. If that fails, somebody else is
4267 * making progress for us.
4269 if (!mutex_trylock(&oom_lock)) {
4270 *did_some_progress = 1;
4271 schedule_timeout_uninterruptible(1);
4276 * Go through the zonelist yet one more time, keep very high watermark
4277 * here, this is only to catch a parallel oom killing, we must fail if
4278 * we're still under heavy pressure. But make sure that this reclaim
4279 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
4280 * allocation which will never fail due to oom_lock already held.
4282 page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
4283 ~__GFP_DIRECT_RECLAIM, order,
4284 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
4288 /* Coredumps can quickly deplete all memory reserves */
4289 if (current->flags & PF_DUMPCORE)
4291 /* The OOM killer will not help higher order allocs */
4292 if (order > PAGE_ALLOC_COSTLY_ORDER)
4295 * We have already exhausted all our reclaim opportunities without any
4296 * success so it is time to admit defeat. We will skip the OOM killer
4297 * because it is very likely that the caller has a more reasonable
4298 * fallback than shooting a random task.
4300 * The OOM killer may not free memory on a specific node.
4302 if (gfp_mask & (__GFP_RETRY_MAYFAIL | __GFP_THISNODE))
4304 /* The OOM killer does not needlessly kill tasks for lowmem */
4305 if (ac->highest_zoneidx < ZONE_NORMAL)
4307 if (pm_suspended_storage())
4310 * XXX: GFP_NOFS allocations should rather fail than rely on
4311 * other request to make a forward progress.
4312 * We are in an unfortunate situation where out_of_memory cannot
4313 * do much for this context but let's try it to at least get
4314 * access to memory reserved if the current task is killed (see
4315 * out_of_memory). Once filesystems are ready to handle allocation
4316 * failures more gracefully we should just bail out here.
4319 /* Exhausted what can be done so it's blame time */
4320 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
4321 *did_some_progress = 1;
4324 * Help non-failing allocations by giving them access to memory
4327 if (gfp_mask & __GFP_NOFAIL)
4328 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
4329 ALLOC_NO_WATERMARKS, ac);
4332 mutex_unlock(&oom_lock);
4337 * Maximum number of compaction retries with a progress before OOM
4338 * killer is consider as the only way to move forward.
4340 #define MAX_COMPACT_RETRIES 16
4342 #ifdef CONFIG_COMPACTION
4343 /* Try memory compaction for high-order allocations before reclaim */
4344 static struct page *
4345 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4346 unsigned int alloc_flags, const struct alloc_context *ac,
4347 enum compact_priority prio, enum compact_result *compact_result)
4349 struct page *page = NULL;
4350 unsigned long pflags;
4351 unsigned int noreclaim_flag;
4356 psi_memstall_enter(&pflags);
4357 noreclaim_flag = memalloc_noreclaim_save();
4359 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
4362 memalloc_noreclaim_restore(noreclaim_flag);
4363 psi_memstall_leave(&pflags);
4365 if (*compact_result == COMPACT_SKIPPED)
4368 * At least in one zone compaction wasn't deferred or skipped, so let's
4369 * count a compaction stall
4371 count_vm_event(COMPACTSTALL);
4373 /* Prep a captured page if available */
4375 prep_new_page(page, order, gfp_mask, alloc_flags);
4377 /* Try get a page from the freelist if available */
4379 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4382 struct zone *zone = page_zone(page);
4384 zone->compact_blockskip_flush = false;
4385 compaction_defer_reset(zone, order, true);
4386 count_vm_event(COMPACTSUCCESS);
4391 * It's bad if compaction run occurs and fails. The most likely reason
4392 * is that pages exist, but not enough to satisfy watermarks.
4394 count_vm_event(COMPACTFAIL);
4402 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
4403 enum compact_result compact_result,
4404 enum compact_priority *compact_priority,
4405 int *compaction_retries)
4407 int max_retries = MAX_COMPACT_RETRIES;
4410 int retries = *compaction_retries;
4411 enum compact_priority priority = *compact_priority;
4416 if (fatal_signal_pending(current))
4419 if (compaction_made_progress(compact_result))
4420 (*compaction_retries)++;
4423 * compaction considers all the zone as desperately out of memory
4424 * so it doesn't really make much sense to retry except when the
4425 * failure could be caused by insufficient priority
4427 if (compaction_failed(compact_result))
4428 goto check_priority;
4431 * compaction was skipped because there are not enough order-0 pages
4432 * to work with, so we retry only if it looks like reclaim can help.
4434 if (compaction_needs_reclaim(compact_result)) {
4435 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
4440 * make sure the compaction wasn't deferred or didn't bail out early
4441 * due to locks contention before we declare that we should give up.
4442 * But the next retry should use a higher priority if allowed, so
4443 * we don't just keep bailing out endlessly.
4445 if (compaction_withdrawn(compact_result)) {
4446 goto check_priority;
4450 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4451 * costly ones because they are de facto nofail and invoke OOM
4452 * killer to move on while costly can fail and users are ready
4453 * to cope with that. 1/4 retries is rather arbitrary but we
4454 * would need much more detailed feedback from compaction to
4455 * make a better decision.
4457 if (order > PAGE_ALLOC_COSTLY_ORDER)
4459 if (*compaction_retries <= max_retries) {
4465 * Make sure there are attempts at the highest priority if we exhausted
4466 * all retries or failed at the lower priorities.
4469 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
4470 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
4472 if (*compact_priority > min_priority) {
4473 (*compact_priority)--;
4474 *compaction_retries = 0;
4478 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
4482 static inline struct page *
4483 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4484 unsigned int alloc_flags, const struct alloc_context *ac,
4485 enum compact_priority prio, enum compact_result *compact_result)
4487 *compact_result = COMPACT_SKIPPED;
4492 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
4493 enum compact_result compact_result,
4494 enum compact_priority *compact_priority,
4495 int *compaction_retries)
4500 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
4504 * There are setups with compaction disabled which would prefer to loop
4505 * inside the allocator rather than hit the oom killer prematurely.
4506 * Let's give them a good hope and keep retrying while the order-0
4507 * watermarks are OK.
4509 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
4510 ac->highest_zoneidx, ac->nodemask) {
4511 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
4512 ac->highest_zoneidx, alloc_flags))
4517 #endif /* CONFIG_COMPACTION */
4519 #ifdef CONFIG_LOCKDEP
4520 static struct lockdep_map __fs_reclaim_map =
4521 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
4523 static bool __need_reclaim(gfp_t gfp_mask)
4525 /* no reclaim without waiting on it */
4526 if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
4529 /* this guy won't enter reclaim */
4530 if (current->flags & PF_MEMALLOC)
4533 if (gfp_mask & __GFP_NOLOCKDEP)
4539 void __fs_reclaim_acquire(unsigned long ip)
4541 lock_acquire_exclusive(&__fs_reclaim_map, 0, 0, NULL, ip);
4544 void __fs_reclaim_release(unsigned long ip)
4546 lock_release(&__fs_reclaim_map, ip);
4549 void fs_reclaim_acquire(gfp_t gfp_mask)
4551 gfp_mask = current_gfp_context(gfp_mask);
4553 if (__need_reclaim(gfp_mask)) {
4554 if (gfp_mask & __GFP_FS)
4555 __fs_reclaim_acquire(_RET_IP_);
4557 #ifdef CONFIG_MMU_NOTIFIER
4558 lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
4559 lock_map_release(&__mmu_notifier_invalidate_range_start_map);
4564 EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
4566 void fs_reclaim_release(gfp_t gfp_mask)
4568 gfp_mask = current_gfp_context(gfp_mask);
4570 if (__need_reclaim(gfp_mask)) {
4571 if (gfp_mask & __GFP_FS)
4572 __fs_reclaim_release(_RET_IP_);
4575 EXPORT_SYMBOL_GPL(fs_reclaim_release);
4578 /* Perform direct synchronous page reclaim */
4579 static unsigned long
4580 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
4581 const struct alloc_context *ac)
4583 unsigned int noreclaim_flag;
4584 unsigned long pflags, progress;
4588 /* We now go into synchronous reclaim */
4589 cpuset_memory_pressure_bump();
4590 psi_memstall_enter(&pflags);
4591 fs_reclaim_acquire(gfp_mask);
4592 noreclaim_flag = memalloc_noreclaim_save();
4594 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
4597 memalloc_noreclaim_restore(noreclaim_flag);
4598 fs_reclaim_release(gfp_mask);
4599 psi_memstall_leave(&pflags);
4606 /* The really slow allocator path where we enter direct reclaim */
4607 static inline struct page *
4608 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
4609 unsigned int alloc_flags, const struct alloc_context *ac,
4610 unsigned long *did_some_progress)
4612 struct page *page = NULL;
4613 bool drained = false;
4615 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
4616 if (unlikely(!(*did_some_progress)))
4620 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4623 * If an allocation failed after direct reclaim, it could be because
4624 * pages are pinned on the per-cpu lists or in high alloc reserves.
4625 * Shrink them and try again
4627 if (!page && !drained) {
4628 unreserve_highatomic_pageblock(ac, false);
4629 drain_all_pages(NULL);
4637 static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
4638 const struct alloc_context *ac)
4642 pg_data_t *last_pgdat = NULL;
4643 enum zone_type highest_zoneidx = ac->highest_zoneidx;
4645 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
4647 if (last_pgdat != zone->zone_pgdat)
4648 wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
4649 last_pgdat = zone->zone_pgdat;
4653 static inline unsigned int
4654 gfp_to_alloc_flags(gfp_t gfp_mask)
4656 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
4659 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4660 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4661 * to save two branches.
4663 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
4664 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD);
4667 * The caller may dip into page reserves a bit more if the caller
4668 * cannot run direct reclaim, or if the caller has realtime scheduling
4669 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4670 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4672 alloc_flags |= (__force int)
4673 (gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM));
4675 if (gfp_mask & __GFP_ATOMIC) {
4677 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4678 * if it can't schedule.
4680 if (!(gfp_mask & __GFP_NOMEMALLOC))
4681 alloc_flags |= ALLOC_HARDER;
4683 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4684 * comment for __cpuset_node_allowed().
4686 alloc_flags &= ~ALLOC_CPUSET;
4687 } else if (unlikely(rt_task(current)) && in_task())
4688 alloc_flags |= ALLOC_HARDER;
4690 alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags);
4695 static bool oom_reserves_allowed(struct task_struct *tsk)
4697 if (!tsk_is_oom_victim(tsk))
4701 * !MMU doesn't have oom reaper so give access to memory reserves
4702 * only to the thread with TIF_MEMDIE set
4704 if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
4711 * Distinguish requests which really need access to full memory
4712 * reserves from oom victims which can live with a portion of it
4714 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
4716 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
4718 if (gfp_mask & __GFP_MEMALLOC)
4719 return ALLOC_NO_WATERMARKS;
4720 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
4721 return ALLOC_NO_WATERMARKS;
4722 if (!in_interrupt()) {
4723 if (current->flags & PF_MEMALLOC)
4724 return ALLOC_NO_WATERMARKS;
4725 else if (oom_reserves_allowed(current))
4732 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
4734 return !!__gfp_pfmemalloc_flags(gfp_mask);
4738 * Checks whether it makes sense to retry the reclaim to make a forward progress
4739 * for the given allocation request.
4741 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4742 * without success, or when we couldn't even meet the watermark if we
4743 * reclaimed all remaining pages on the LRU lists.
4745 * Returns true if a retry is viable or false to enter the oom path.
4748 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
4749 struct alloc_context *ac, int alloc_flags,
4750 bool did_some_progress, int *no_progress_loops)
4757 * Costly allocations might have made a progress but this doesn't mean
4758 * their order will become available due to high fragmentation so
4759 * always increment the no progress counter for them
4761 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
4762 *no_progress_loops = 0;
4764 (*no_progress_loops)++;
4767 * Make sure we converge to OOM if we cannot make any progress
4768 * several times in the row.
4770 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
4771 /* Before OOM, exhaust highatomic_reserve */
4772 return unreserve_highatomic_pageblock(ac, true);
4776 * Keep reclaiming pages while there is a chance this will lead
4777 * somewhere. If none of the target zones can satisfy our allocation
4778 * request even if all reclaimable pages are considered then we are
4779 * screwed and have to go OOM.
4781 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
4782 ac->highest_zoneidx, ac->nodemask) {
4783 unsigned long available;
4784 unsigned long reclaimable;
4785 unsigned long min_wmark = min_wmark_pages(zone);
4788 available = reclaimable = zone_reclaimable_pages(zone);
4789 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
4792 * Would the allocation succeed if we reclaimed all
4793 * reclaimable pages?
4795 wmark = __zone_watermark_ok(zone, order, min_wmark,
4796 ac->highest_zoneidx, alloc_flags, available);
4797 trace_reclaim_retry_zone(z, order, reclaimable,
4798 available, min_wmark, *no_progress_loops, wmark);
4801 * If we didn't make any progress and have a lot of
4802 * dirty + writeback pages then we should wait for
4803 * an IO to complete to slow down the reclaim and
4804 * prevent from pre mature OOM
4806 if (!did_some_progress) {
4807 unsigned long write_pending;
4809 write_pending = zone_page_state_snapshot(zone,
4810 NR_ZONE_WRITE_PENDING);
4812 if (2 * write_pending > reclaimable) {
4813 congestion_wait(BLK_RW_ASYNC, HZ/10);
4825 * Memory allocation/reclaim might be called from a WQ context and the
4826 * current implementation of the WQ concurrency control doesn't
4827 * recognize that a particular WQ is congested if the worker thread is
4828 * looping without ever sleeping. Therefore we have to do a short sleep
4829 * here rather than calling cond_resched().
4831 if (current->flags & PF_WQ_WORKER)
4832 schedule_timeout_uninterruptible(1);
4839 check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
4842 * It's possible that cpuset's mems_allowed and the nodemask from
4843 * mempolicy don't intersect. This should be normally dealt with by
4844 * policy_nodemask(), but it's possible to race with cpuset update in
4845 * such a way the check therein was true, and then it became false
4846 * before we got our cpuset_mems_cookie here.
4847 * This assumes that for all allocations, ac->nodemask can come only
4848 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4849 * when it does not intersect with the cpuset restrictions) or the
4850 * caller can deal with a violated nodemask.
4852 if (cpusets_enabled() && ac->nodemask &&
4853 !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
4854 ac->nodemask = NULL;
4859 * When updating a task's mems_allowed or mempolicy nodemask, it is
4860 * possible to race with parallel threads in such a way that our
4861 * allocation can fail while the mask is being updated. If we are about
4862 * to fail, check if the cpuset changed during allocation and if so,
4865 if (read_mems_allowed_retry(cpuset_mems_cookie))
4871 static inline struct page *
4872 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
4873 struct alloc_context *ac)
4875 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
4876 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
4877 struct page *page = NULL;
4878 unsigned int alloc_flags;
4879 unsigned long did_some_progress;
4880 enum compact_priority compact_priority;
4881 enum compact_result compact_result;
4882 int compaction_retries;
4883 int no_progress_loops;
4884 unsigned int cpuset_mems_cookie;
4888 * We also sanity check to catch abuse of atomic reserves being used by
4889 * callers that are not in atomic context.
4891 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
4892 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
4893 gfp_mask &= ~__GFP_ATOMIC;
4896 compaction_retries = 0;
4897 no_progress_loops = 0;
4898 compact_priority = DEF_COMPACT_PRIORITY;
4899 cpuset_mems_cookie = read_mems_allowed_begin();
4902 * The fast path uses conservative alloc_flags to succeed only until
4903 * kswapd needs to be woken up, and to avoid the cost of setting up
4904 * alloc_flags precisely. So we do that now.
4906 alloc_flags = gfp_to_alloc_flags(gfp_mask);
4909 * We need to recalculate the starting point for the zonelist iterator
4910 * because we might have used different nodemask in the fast path, or
4911 * there was a cpuset modification and we are retrying - otherwise we
4912 * could end up iterating over non-eligible zones endlessly.
4914 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4915 ac->highest_zoneidx, ac->nodemask);
4916 if (!ac->preferred_zoneref->zone)
4919 if (alloc_flags & ALLOC_KSWAPD)
4920 wake_all_kswapds(order, gfp_mask, ac);
4923 * The adjusted alloc_flags might result in immediate success, so try
4926 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4931 * For costly allocations, try direct compaction first, as it's likely
4932 * that we have enough base pages and don't need to reclaim. For non-
4933 * movable high-order allocations, do that as well, as compaction will
4934 * try prevent permanent fragmentation by migrating from blocks of the
4936 * Don't try this for allocations that are allowed to ignore
4937 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4939 if (can_direct_reclaim &&
4941 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
4942 && !gfp_pfmemalloc_allowed(gfp_mask)) {
4943 page = __alloc_pages_direct_compact(gfp_mask, order,
4945 INIT_COMPACT_PRIORITY,
4951 * Checks for costly allocations with __GFP_NORETRY, which
4952 * includes some THP page fault allocations
4954 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
4956 * If allocating entire pageblock(s) and compaction
4957 * failed because all zones are below low watermarks
4958 * or is prohibited because it recently failed at this
4959 * order, fail immediately unless the allocator has
4960 * requested compaction and reclaim retry.
4963 * - potentially very expensive because zones are far
4964 * below their low watermarks or this is part of very
4965 * bursty high order allocations,
4966 * - not guaranteed to help because isolate_freepages()
4967 * may not iterate over freed pages as part of its
4969 * - unlikely to make entire pageblocks free on its
4972 if (compact_result == COMPACT_SKIPPED ||
4973 compact_result == COMPACT_DEFERRED)
4977 * Looks like reclaim/compaction is worth trying, but
4978 * sync compaction could be very expensive, so keep
4979 * using async compaction.
4981 compact_priority = INIT_COMPACT_PRIORITY;
4986 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4987 if (alloc_flags & ALLOC_KSWAPD)
4988 wake_all_kswapds(order, gfp_mask, ac);
4990 reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
4992 alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags);
4995 * Reset the nodemask and zonelist iterators if memory policies can be
4996 * ignored. These allocations are high priority and system rather than
4999 if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
5000 ac->nodemask = NULL;
5001 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
5002 ac->highest_zoneidx, ac->nodemask);
5005 /* Attempt with potentially adjusted zonelist and alloc_flags */
5006 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
5010 /* Caller is not willing to reclaim, we can't balance anything */
5011 if (!can_direct_reclaim)
5014 /* Avoid recursion of direct reclaim */
5015 if (current->flags & PF_MEMALLOC)
5018 /* Try direct reclaim and then allocating */
5019 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
5020 &did_some_progress);
5024 /* Try direct compaction and then allocating */
5025 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
5026 compact_priority, &compact_result);
5030 /* Do not loop if specifically requested */
5031 if (gfp_mask & __GFP_NORETRY)
5035 * Do not retry costly high order allocations unless they are
5036 * __GFP_RETRY_MAYFAIL
5038 if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
5041 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
5042 did_some_progress > 0, &no_progress_loops))
5046 * It doesn't make any sense to retry for the compaction if the order-0
5047 * reclaim is not able to make any progress because the current
5048 * implementation of the compaction depends on the sufficient amount
5049 * of free memory (see __compaction_suitable)
5051 if (did_some_progress > 0 &&
5052 should_compact_retry(ac, order, alloc_flags,
5053 compact_result, &compact_priority,
5054 &compaction_retries))
5058 /* Deal with possible cpuset update races before we start OOM killing */
5059 if (check_retry_cpuset(cpuset_mems_cookie, ac))
5062 /* Reclaim has failed us, start killing things */
5063 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
5067 /* Avoid allocations with no watermarks from looping endlessly */
5068 if (tsk_is_oom_victim(current) &&
5069 (alloc_flags & ALLOC_OOM ||
5070 (gfp_mask & __GFP_NOMEMALLOC)))
5073 /* Retry as long as the OOM killer is making progress */
5074 if (did_some_progress) {
5075 no_progress_loops = 0;
5080 /* Deal with possible cpuset update races before we fail */
5081 if (check_retry_cpuset(cpuset_mems_cookie, ac))
5085 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
5088 if (gfp_mask & __GFP_NOFAIL) {
5090 * All existing users of the __GFP_NOFAIL are blockable, so warn
5091 * of any new users that actually require GFP_NOWAIT
5093 if (WARN_ON_ONCE(!can_direct_reclaim))
5097 * PF_MEMALLOC request from this context is rather bizarre
5098 * because we cannot reclaim anything and only can loop waiting
5099 * for somebody to do a work for us
5101 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
5104 * non failing costly orders are a hard requirement which we
5105 * are not prepared for much so let's warn about these users
5106 * so that we can identify them and convert them to something
5109 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
5112 * Help non-failing allocations by giving them access to memory
5113 * reserves but do not use ALLOC_NO_WATERMARKS because this
5114 * could deplete whole memory reserves which would just make
5115 * the situation worse
5117 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
5125 warn_alloc(gfp_mask, ac->nodemask,
5126 "page allocation failure: order:%u", order);
5131 static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
5132 int preferred_nid, nodemask_t *nodemask,
5133 struct alloc_context *ac, gfp_t *alloc_gfp,
5134 unsigned int *alloc_flags)
5136 ac->highest_zoneidx = gfp_zone(gfp_mask);
5137 ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
5138 ac->nodemask = nodemask;
5139 ac->migratetype = gfp_migratetype(gfp_mask);
5141 if (cpusets_enabled()) {
5142 *alloc_gfp |= __GFP_HARDWALL;
5144 * When we are in the interrupt context, it is irrelevant
5145 * to the current task context. It means that any node ok.
5147 if (in_task() && !ac->nodemask)
5148 ac->nodemask = &cpuset_current_mems_allowed;
5150 *alloc_flags |= ALLOC_CPUSET;
5153 fs_reclaim_acquire(gfp_mask);
5154 fs_reclaim_release(gfp_mask);
5156 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
5158 if (should_fail_alloc_page(gfp_mask, order))
5161 *alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags);
5163 /* Dirty zone balancing only done in the fast path */
5164 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
5167 * The preferred zone is used for statistics but crucially it is
5168 * also used as the starting point for the zonelist iterator. It
5169 * may get reset for allocations that ignore memory policies.
5171 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
5172 ac->highest_zoneidx, ac->nodemask);
5178 * __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
5179 * @gfp: GFP flags for the allocation
5180 * @preferred_nid: The preferred NUMA node ID to allocate from
5181 * @nodemask: Set of nodes to allocate from, may be NULL
5182 * @nr_pages: The number of pages desired on the list or array
5183 * @page_list: Optional list to store the allocated pages
5184 * @page_array: Optional array to store the pages
5186 * This is a batched version of the page allocator that attempts to
5187 * allocate nr_pages quickly. Pages are added to page_list if page_list
5188 * is not NULL, otherwise it is assumed that the page_array is valid.
5190 * For lists, nr_pages is the number of pages that should be allocated.
5192 * For arrays, only NULL elements are populated with pages and nr_pages
5193 * is the maximum number of pages that will be stored in the array.
5195 * Returns the number of pages on the list or array.
5197 unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
5198 nodemask_t *nodemask, int nr_pages,
5199 struct list_head *page_list,
5200 struct page **page_array)
5203 unsigned long flags;
5206 struct per_cpu_pages *pcp;
5207 struct list_head *pcp_list;
5208 struct alloc_context ac;
5210 unsigned int alloc_flags = ALLOC_WMARK_LOW;
5211 int nr_populated = 0, nr_account = 0;
5214 * Skip populated array elements to determine if any pages need
5215 * to be allocated before disabling IRQs.
5217 while (page_array && nr_populated < nr_pages && page_array[nr_populated])
5220 /* No pages requested? */
5221 if (unlikely(nr_pages <= 0))
5224 /* Already populated array? */
5225 if (unlikely(page_array && nr_pages - nr_populated == 0))
5228 /* Bulk allocator does not support memcg accounting. */
5229 if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
5232 /* Use the single page allocator for one page. */
5233 if (nr_pages - nr_populated == 1)
5236 #ifdef CONFIG_PAGE_OWNER
5238 * PAGE_OWNER may recurse into the allocator to allocate space to
5239 * save the stack with pagesets.lock held. Releasing/reacquiring
5240 * removes much of the performance benefit of bulk allocation so
5241 * force the caller to allocate one page at a time as it'll have
5242 * similar performance to added complexity to the bulk allocator.
5244 if (static_branch_unlikely(&page_owner_inited))
5248 /* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */
5249 gfp &= gfp_allowed_mask;
5251 if (!prepare_alloc_pages(gfp, 0, preferred_nid, nodemask, &ac, &alloc_gfp, &alloc_flags))
5255 /* Find an allowed local zone that meets the low watermark. */
5256 for_each_zone_zonelist_nodemask(zone, z, ac.zonelist, ac.highest_zoneidx, ac.nodemask) {
5259 if (cpusets_enabled() && (alloc_flags & ALLOC_CPUSET) &&
5260 !__cpuset_zone_allowed(zone, gfp)) {
5264 if (nr_online_nodes > 1 && zone != ac.preferred_zoneref->zone &&
5265 zone_to_nid(zone) != zone_to_nid(ac.preferred_zoneref->zone)) {
5269 mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK) + nr_pages;
5270 if (zone_watermark_fast(zone, 0, mark,
5271 zonelist_zone_idx(ac.preferred_zoneref),
5272 alloc_flags, gfp)) {
5278 * If there are no allowed local zones that meets the watermarks then
5279 * try to allocate a single page and reclaim if necessary.
5281 if (unlikely(!zone))
5284 /* Attempt the batch allocation */
5285 local_lock_irqsave(&pagesets.lock, flags);
5286 pcp = this_cpu_ptr(zone->per_cpu_pageset);
5287 pcp_list = &pcp->lists[order_to_pindex(ac.migratetype, 0)];
5289 while (nr_populated < nr_pages) {
5291 /* Skip existing pages */
5292 if (page_array && page_array[nr_populated]) {
5297 page = __rmqueue_pcplist(zone, 0, ac.migratetype, alloc_flags,
5299 if (unlikely(!page)) {
5300 /* Try and get at least one page */
5307 prep_new_page(page, 0, gfp, 0);
5309 list_add(&page->lru, page_list);
5311 page_array[nr_populated] = page;
5315 local_unlock_irqrestore(&pagesets.lock, flags);
5317 __count_zid_vm_events(PGALLOC, zone_idx(zone), nr_account);
5318 zone_statistics(ac.preferred_zoneref->zone, zone, nr_account);
5321 return nr_populated;
5324 local_unlock_irqrestore(&pagesets.lock, flags);
5327 page = __alloc_pages(gfp, 0, preferred_nid, nodemask);
5330 list_add(&page->lru, page_list);
5332 page_array[nr_populated] = page;
5338 EXPORT_SYMBOL_GPL(__alloc_pages_bulk);
5341 * This is the 'heart' of the zoned buddy allocator.
5343 struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
5344 nodemask_t *nodemask)
5347 unsigned int alloc_flags = ALLOC_WMARK_LOW;
5348 gfp_t alloc_gfp; /* The gfp_t that was actually used for allocation */
5349 struct alloc_context ac = { };
5352 * There are several places where we assume that the order value is sane
5353 * so bail out early if the request is out of bound.
5355 if (unlikely(order >= MAX_ORDER)) {
5356 WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
5360 gfp &= gfp_allowed_mask;
5362 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
5363 * resp. GFP_NOIO which has to be inherited for all allocation requests
5364 * from a particular context which has been marked by
5365 * memalloc_no{fs,io}_{save,restore}. And PF_MEMALLOC_PIN which ensures
5366 * movable zones are not used during allocation.
5368 gfp = current_gfp_context(gfp);
5370 if (!prepare_alloc_pages(gfp, order, preferred_nid, nodemask, &ac,
5371 &alloc_gfp, &alloc_flags))
5375 * Forbid the first pass from falling back to types that fragment
5376 * memory until all local zones are considered.
5378 alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp);
5380 /* First allocation attempt */
5381 page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac);
5386 ac.spread_dirty_pages = false;
5389 * Restore the original nodemask if it was potentially replaced with
5390 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
5392 ac.nodemask = nodemask;
5394 page = __alloc_pages_slowpath(alloc_gfp, order, &ac);
5397 if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT) && page &&
5398 unlikely(__memcg_kmem_charge_page(page, gfp, order) != 0)) {
5399 __free_pages(page, order);
5403 trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype);
5407 EXPORT_SYMBOL(__alloc_pages);
5409 struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
5410 nodemask_t *nodemask)
5412 struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
5413 preferred_nid, nodemask);
5415 if (page && order > 1)
5416 prep_transhuge_page(page);
5417 return (struct folio *)page;
5419 EXPORT_SYMBOL(__folio_alloc);
5422 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
5423 * address cannot represent highmem pages. Use alloc_pages and then kmap if
5424 * you need to access high mem.
5426 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
5430 page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order);
5433 return (unsigned long) page_address(page);
5435 EXPORT_SYMBOL(__get_free_pages);
5437 unsigned long get_zeroed_page(gfp_t gfp_mask)
5439 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
5441 EXPORT_SYMBOL(get_zeroed_page);
5444 * __free_pages - Free pages allocated with alloc_pages().
5445 * @page: The page pointer returned from alloc_pages().
5446 * @order: The order of the allocation.
5448 * This function can free multi-page allocations that are not compound
5449 * pages. It does not check that the @order passed in matches that of
5450 * the allocation, so it is easy to leak memory. Freeing more memory
5451 * than was allocated will probably emit a warning.
5453 * If the last reference to this page is speculative, it will be released
5454 * by put_page() which only frees the first page of a non-compound
5455 * allocation. To prevent the remaining pages from being leaked, we free
5456 * the subsequent pages here. If you want to use the page's reference
5457 * count to decide when to free the allocation, you should allocate a
5458 * compound page, and use put_page() instead of __free_pages().
5460 * Context: May be called in interrupt context or while holding a normal
5461 * spinlock, but not in NMI context or while holding a raw spinlock.
5463 void __free_pages(struct page *page, unsigned int order)
5465 if (put_page_testzero(page))
5466 free_the_page(page, order);
5467 else if (!PageHead(page))
5469 free_the_page(page + (1 << order), order);
5471 EXPORT_SYMBOL(__free_pages);
5473 void free_pages(unsigned long addr, unsigned int order)
5476 VM_BUG_ON(!virt_addr_valid((void *)addr));
5477 __free_pages(virt_to_page((void *)addr), order);
5481 EXPORT_SYMBOL(free_pages);
5485 * An arbitrary-length arbitrary-offset area of memory which resides
5486 * within a 0 or higher order page. Multiple fragments within that page
5487 * are individually refcounted, in the page's reference counter.
5489 * The page_frag functions below provide a simple allocation framework for
5490 * page fragments. This is used by the network stack and network device
5491 * drivers to provide a backing region of memory for use as either an
5492 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
5494 static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
5497 struct page *page = NULL;
5498 gfp_t gfp = gfp_mask;
5500 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5501 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
5503 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
5504 PAGE_FRAG_CACHE_MAX_ORDER);
5505 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
5507 if (unlikely(!page))
5508 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
5510 nc->va = page ? page_address(page) : NULL;
5515 void __page_frag_cache_drain(struct page *page, unsigned int count)
5517 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
5519 if (page_ref_sub_and_test(page, count))
5520 free_the_page(page, compound_order(page));
5522 EXPORT_SYMBOL(__page_frag_cache_drain);
5524 void *page_frag_alloc_align(struct page_frag_cache *nc,
5525 unsigned int fragsz, gfp_t gfp_mask,
5526 unsigned int align_mask)
5528 unsigned int size = PAGE_SIZE;
5532 if (unlikely(!nc->va)) {
5534 page = __page_frag_cache_refill(nc, gfp_mask);
5538 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5539 /* if size can vary use size else just use PAGE_SIZE */
5542 /* Even if we own the page, we do not use atomic_set().
5543 * This would break get_page_unless_zero() users.
5545 page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE);
5547 /* reset page count bias and offset to start of new frag */
5548 nc->pfmemalloc = page_is_pfmemalloc(page);
5549 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
5553 offset = nc->offset - fragsz;
5554 if (unlikely(offset < 0)) {
5555 page = virt_to_page(nc->va);
5557 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
5560 if (unlikely(nc->pfmemalloc)) {
5561 free_the_page(page, compound_order(page));
5565 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5566 /* if size can vary use size else just use PAGE_SIZE */
5569 /* OK, page count is 0, we can safely set it */
5570 set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1);
5572 /* reset page count bias and offset to start of new frag */
5573 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
5574 offset = size - fragsz;
5578 offset &= align_mask;
5579 nc->offset = offset;
5581 return nc->va + offset;
5583 EXPORT_SYMBOL(page_frag_alloc_align);
5586 * Frees a page fragment allocated out of either a compound or order 0 page.
5588 void page_frag_free(void *addr)
5590 struct page *page = virt_to_head_page(addr);
5592 if (unlikely(put_page_testzero(page)))
5593 free_the_page(page, compound_order(page));
5595 EXPORT_SYMBOL(page_frag_free);
5597 static void *make_alloc_exact(unsigned long addr, unsigned int order,
5601 unsigned long alloc_end = addr + (PAGE_SIZE << order);
5602 unsigned long used = addr + PAGE_ALIGN(size);
5604 split_page(virt_to_page((void *)addr), order);
5605 while (used < alloc_end) {
5610 return (void *)addr;
5614 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5615 * @size: the number of bytes to allocate
5616 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5618 * This function is similar to alloc_pages(), except that it allocates the
5619 * minimum number of pages to satisfy the request. alloc_pages() can only
5620 * allocate memory in power-of-two pages.
5622 * This function is also limited by MAX_ORDER.
5624 * Memory allocated by this function must be released by free_pages_exact().
5626 * Return: pointer to the allocated area or %NULL in case of error.
5628 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
5630 unsigned int order = get_order(size);
5633 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5634 gfp_mask &= ~__GFP_COMP;
5636 addr = __get_free_pages(gfp_mask, order);
5637 return make_alloc_exact(addr, order, size);
5639 EXPORT_SYMBOL(alloc_pages_exact);
5642 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5644 * @nid: the preferred node ID where memory should be allocated
5645 * @size: the number of bytes to allocate
5646 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5648 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5651 * Return: pointer to the allocated area or %NULL in case of error.
5653 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
5655 unsigned int order = get_order(size);
5658 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5659 gfp_mask &= ~__GFP_COMP;
5661 p = alloc_pages_node(nid, gfp_mask, order);
5664 return make_alloc_exact((unsigned long)page_address(p), order, size);
5668 * free_pages_exact - release memory allocated via alloc_pages_exact()
5669 * @virt: the value returned by alloc_pages_exact.
5670 * @size: size of allocation, same value as passed to alloc_pages_exact().
5672 * Release the memory allocated by a previous call to alloc_pages_exact.
5674 void free_pages_exact(void *virt, size_t size)
5676 unsigned long addr = (unsigned long)virt;
5677 unsigned long end = addr + PAGE_ALIGN(size);
5679 while (addr < end) {
5684 EXPORT_SYMBOL(free_pages_exact);
5687 * nr_free_zone_pages - count number of pages beyond high watermark
5688 * @offset: The zone index of the highest zone
5690 * nr_free_zone_pages() counts the number of pages which are beyond the
5691 * high watermark within all zones at or below a given zone index. For each
5692 * zone, the number of pages is calculated as:
5694 * nr_free_zone_pages = managed_pages - high_pages
5696 * Return: number of pages beyond high watermark.
5698 static unsigned long nr_free_zone_pages(int offset)
5703 /* Just pick one node, since fallback list is circular */
5704 unsigned long sum = 0;
5706 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
5708 for_each_zone_zonelist(zone, z, zonelist, offset) {
5709 unsigned long size = zone_managed_pages(zone);
5710 unsigned long high = high_wmark_pages(zone);
5719 * nr_free_buffer_pages - count number of pages beyond high watermark
5721 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5722 * watermark within ZONE_DMA and ZONE_NORMAL.
5724 * Return: number of pages beyond high watermark within ZONE_DMA and
5727 unsigned long nr_free_buffer_pages(void)
5729 return nr_free_zone_pages(gfp_zone(GFP_USER));
5731 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
5733 static inline void show_node(struct zone *zone)
5735 if (IS_ENABLED(CONFIG_NUMA))
5736 printk("Node %d ", zone_to_nid(zone));
5739 long si_mem_available(void)
5742 unsigned long pagecache;
5743 unsigned long wmark_low = 0;
5744 unsigned long pages[NR_LRU_LISTS];
5745 unsigned long reclaimable;
5749 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
5750 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
5753 wmark_low += low_wmark_pages(zone);
5756 * Estimate the amount of memory available for userspace allocations,
5757 * without causing swapping.
5759 available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
5762 * Not all the page cache can be freed, otherwise the system will
5763 * start swapping. Assume at least half of the page cache, or the
5764 * low watermark worth of cache, needs to stay.
5766 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
5767 pagecache -= min(pagecache / 2, wmark_low);
5768 available += pagecache;
5771 * Part of the reclaimable slab and other kernel memory consists of
5772 * items that are in use, and cannot be freed. Cap this estimate at the
5775 reclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) +
5776 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE);
5777 available += reclaimable - min(reclaimable / 2, wmark_low);
5783 EXPORT_SYMBOL_GPL(si_mem_available);
5785 void si_meminfo(struct sysinfo *val)
5787 val->totalram = totalram_pages();
5788 val->sharedram = global_node_page_state(NR_SHMEM);
5789 val->freeram = global_zone_page_state(NR_FREE_PAGES);
5790 val->bufferram = nr_blockdev_pages();
5791 val->totalhigh = totalhigh_pages();
5792 val->freehigh = nr_free_highpages();
5793 val->mem_unit = PAGE_SIZE;
5796 EXPORT_SYMBOL(si_meminfo);
5799 void si_meminfo_node(struct sysinfo *val, int nid)
5801 int zone_type; /* needs to be signed */
5802 unsigned long managed_pages = 0;
5803 unsigned long managed_highpages = 0;
5804 unsigned long free_highpages = 0;
5805 pg_data_t *pgdat = NODE_DATA(nid);
5807 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
5808 managed_pages += zone_managed_pages(&pgdat->node_zones[zone_type]);
5809 val->totalram = managed_pages;
5810 val->sharedram = node_page_state(pgdat, NR_SHMEM);
5811 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
5812 #ifdef CONFIG_HIGHMEM
5813 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
5814 struct zone *zone = &pgdat->node_zones[zone_type];
5816 if (is_highmem(zone)) {
5817 managed_highpages += zone_managed_pages(zone);
5818 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
5821 val->totalhigh = managed_highpages;
5822 val->freehigh = free_highpages;
5824 val->totalhigh = managed_highpages;
5825 val->freehigh = free_highpages;
5827 val->mem_unit = PAGE_SIZE;
5832 * Determine whether the node should be displayed or not, depending on whether
5833 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5835 static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
5837 if (!(flags & SHOW_MEM_FILTER_NODES))
5841 * no node mask - aka implicit memory numa policy. Do not bother with
5842 * the synchronization - read_mems_allowed_begin - because we do not
5843 * have to be precise here.
5846 nodemask = &cpuset_current_mems_allowed;
5848 return !node_isset(nid, *nodemask);
5851 #define K(x) ((x) << (PAGE_SHIFT-10))
5853 static void show_migration_types(unsigned char type)
5855 static const char types[MIGRATE_TYPES] = {
5856 [MIGRATE_UNMOVABLE] = 'U',
5857 [MIGRATE_MOVABLE] = 'M',
5858 [MIGRATE_RECLAIMABLE] = 'E',
5859 [MIGRATE_HIGHATOMIC] = 'H',
5861 [MIGRATE_CMA] = 'C',
5863 #ifdef CONFIG_MEMORY_ISOLATION
5864 [MIGRATE_ISOLATE] = 'I',
5867 char tmp[MIGRATE_TYPES + 1];
5871 for (i = 0; i < MIGRATE_TYPES; i++) {
5872 if (type & (1 << i))
5877 printk(KERN_CONT "(%s) ", tmp);
5881 * Show free area list (used inside shift_scroll-lock stuff)
5882 * We also calculate the percentage fragmentation. We do this by counting the
5883 * memory on each free list with the exception of the first item on the list.
5886 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5889 void show_free_areas(unsigned int filter, nodemask_t *nodemask)
5891 unsigned long free_pcp = 0;
5896 for_each_populated_zone(zone) {
5897 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5900 for_each_online_cpu(cpu)
5901 free_pcp += per_cpu_ptr(zone->per_cpu_pageset, cpu)->count;
5904 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5905 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5906 " unevictable:%lu dirty:%lu writeback:%lu\n"
5907 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5908 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5909 " kernel_misc_reclaimable:%lu\n"
5910 " free:%lu free_pcp:%lu free_cma:%lu\n",
5911 global_node_page_state(NR_ACTIVE_ANON),
5912 global_node_page_state(NR_INACTIVE_ANON),
5913 global_node_page_state(NR_ISOLATED_ANON),
5914 global_node_page_state(NR_ACTIVE_FILE),
5915 global_node_page_state(NR_INACTIVE_FILE),
5916 global_node_page_state(NR_ISOLATED_FILE),
5917 global_node_page_state(NR_UNEVICTABLE),
5918 global_node_page_state(NR_FILE_DIRTY),
5919 global_node_page_state(NR_WRITEBACK),
5920 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B),
5921 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B),
5922 global_node_page_state(NR_FILE_MAPPED),
5923 global_node_page_state(NR_SHMEM),
5924 global_node_page_state(NR_PAGETABLE),
5925 global_zone_page_state(NR_BOUNCE),
5926 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE),
5927 global_zone_page_state(NR_FREE_PAGES),
5929 global_zone_page_state(NR_FREE_CMA_PAGES));
5931 for_each_online_pgdat(pgdat) {
5932 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
5936 " active_anon:%lukB"
5937 " inactive_anon:%lukB"
5938 " active_file:%lukB"
5939 " inactive_file:%lukB"
5940 " unevictable:%lukB"
5941 " isolated(anon):%lukB"
5942 " isolated(file):%lukB"
5947 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5949 " shmem_pmdmapped: %lukB"
5952 " writeback_tmp:%lukB"
5953 " kernel_stack:%lukB"
5954 #ifdef CONFIG_SHADOW_CALL_STACK
5955 " shadow_call_stack:%lukB"
5958 " all_unreclaimable? %s"
5961 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
5962 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
5963 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
5964 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
5965 K(node_page_state(pgdat, NR_UNEVICTABLE)),
5966 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
5967 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
5968 K(node_page_state(pgdat, NR_FILE_MAPPED)),
5969 K(node_page_state(pgdat, NR_FILE_DIRTY)),
5970 K(node_page_state(pgdat, NR_WRITEBACK)),
5971 K(node_page_state(pgdat, NR_SHMEM)),
5972 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5973 K(node_page_state(pgdat, NR_SHMEM_THPS)),
5974 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
5975 K(node_page_state(pgdat, NR_ANON_THPS)),
5977 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
5978 node_page_state(pgdat, NR_KERNEL_STACK_KB),
5979 #ifdef CONFIG_SHADOW_CALL_STACK
5980 node_page_state(pgdat, NR_KERNEL_SCS_KB),
5982 K(node_page_state(pgdat, NR_PAGETABLE)),
5983 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
5987 for_each_populated_zone(zone) {
5990 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5994 for_each_online_cpu(cpu)
5995 free_pcp += per_cpu_ptr(zone->per_cpu_pageset, cpu)->count;
6004 " reserved_highatomic:%luKB"
6005 " active_anon:%lukB"
6006 " inactive_anon:%lukB"
6007 " active_file:%lukB"
6008 " inactive_file:%lukB"
6009 " unevictable:%lukB"
6010 " writepending:%lukB"
6020 K(zone_page_state(zone, NR_FREE_PAGES)),
6021 K(min_wmark_pages(zone)),
6022 K(low_wmark_pages(zone)),
6023 K(high_wmark_pages(zone)),
6024 K(zone->nr_reserved_highatomic),
6025 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
6026 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
6027 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
6028 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
6029 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
6030 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
6031 K(zone->present_pages),
6032 K(zone_managed_pages(zone)),
6033 K(zone_page_state(zone, NR_MLOCK)),
6034 K(zone_page_state(zone, NR_BOUNCE)),
6036 K(this_cpu_read(zone->per_cpu_pageset->count)),
6037 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
6038 printk("lowmem_reserve[]:");
6039 for (i = 0; i < MAX_NR_ZONES; i++)
6040 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
6041 printk(KERN_CONT "\n");
6044 for_each_populated_zone(zone) {
6046 unsigned long nr[MAX_ORDER], flags, total = 0;
6047 unsigned char types[MAX_ORDER];
6049 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
6052 printk(KERN_CONT "%s: ", zone->name);
6054 spin_lock_irqsave(&zone->lock, flags);
6055 for (order = 0; order < MAX_ORDER; order++) {
6056 struct free_area *area = &zone->free_area[order];
6059 nr[order] = area->nr_free;
6060 total += nr[order] << order;
6063 for (type = 0; type < MIGRATE_TYPES; type++) {
6064 if (!free_area_empty(area, type))
6065 types[order] |= 1 << type;
6068 spin_unlock_irqrestore(&zone->lock, flags);
6069 for (order = 0; order < MAX_ORDER; order++) {
6070 printk(KERN_CONT "%lu*%lukB ",
6071 nr[order], K(1UL) << order);
6073 show_migration_types(types[order]);
6075 printk(KERN_CONT "= %lukB\n", K(total));
6078 hugetlb_show_meminfo();
6080 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
6082 show_swap_cache_info();
6085 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
6087 zoneref->zone = zone;
6088 zoneref->zone_idx = zone_idx(zone);
6092 * Builds allocation fallback zone lists.
6094 * Add all populated zones of a node to the zonelist.
6096 static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
6099 enum zone_type zone_type = MAX_NR_ZONES;
6104 zone = pgdat->node_zones + zone_type;
6105 if (managed_zone(zone)) {
6106 zoneref_set_zone(zone, &zonerefs[nr_zones++]);
6107 check_highest_zone(zone_type);
6109 } while (zone_type);
6116 static int __parse_numa_zonelist_order(char *s)
6119 * We used to support different zonelists modes but they turned
6120 * out to be just not useful. Let's keep the warning in place
6121 * if somebody still use the cmd line parameter so that we do
6122 * not fail it silently
6124 if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
6125 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
6131 char numa_zonelist_order[] = "Node";
6134 * sysctl handler for numa_zonelist_order
6136 int numa_zonelist_order_handler(struct ctl_table *table, int write,
6137 void *buffer, size_t *length, loff_t *ppos)
6140 return __parse_numa_zonelist_order(buffer);
6141 return proc_dostring(table, write, buffer, length, ppos);
6145 #define MAX_NODE_LOAD (nr_online_nodes)
6146 static int node_load[MAX_NUMNODES];
6149 * find_next_best_node - find the next node that should appear in a given node's fallback list
6150 * @node: node whose fallback list we're appending
6151 * @used_node_mask: nodemask_t of already used nodes
6153 * We use a number of factors to determine which is the next node that should
6154 * appear on a given node's fallback list. The node should not have appeared
6155 * already in @node's fallback list, and it should be the next closest node
6156 * according to the distance array (which contains arbitrary distance values
6157 * from each node to each node in the system), and should also prefer nodes
6158 * with no CPUs, since presumably they'll have very little allocation pressure
6159 * on them otherwise.
6161 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
6163 int find_next_best_node(int node, nodemask_t *used_node_mask)
6166 int min_val = INT_MAX;
6167 int best_node = NUMA_NO_NODE;
6169 /* Use the local node if we haven't already */
6170 if (!node_isset(node, *used_node_mask)) {
6171 node_set(node, *used_node_mask);
6175 for_each_node_state(n, N_MEMORY) {
6177 /* Don't want a node to appear more than once */
6178 if (node_isset(n, *used_node_mask))
6181 /* Use the distance array to find the distance */
6182 val = node_distance(node, n);
6184 /* Penalize nodes under us ("prefer the next node") */
6187 /* Give preference to headless and unused nodes */
6188 if (!cpumask_empty(cpumask_of_node(n)))
6189 val += PENALTY_FOR_NODE_WITH_CPUS;
6191 /* Slight preference for less loaded node */
6192 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
6193 val += node_load[n];
6195 if (val < min_val) {
6202 node_set(best_node, *used_node_mask);
6209 * Build zonelists ordered by node and zones within node.
6210 * This results in maximum locality--normal zone overflows into local
6211 * DMA zone, if any--but risks exhausting DMA zone.
6213 static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
6216 struct zoneref *zonerefs;
6219 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
6221 for (i = 0; i < nr_nodes; i++) {
6224 pg_data_t *node = NODE_DATA(node_order[i]);
6226 nr_zones = build_zonerefs_node(node, zonerefs);
6227 zonerefs += nr_zones;
6229 zonerefs->zone = NULL;
6230 zonerefs->zone_idx = 0;
6234 * Build gfp_thisnode zonelists
6236 static void build_thisnode_zonelists(pg_data_t *pgdat)
6238 struct zoneref *zonerefs;
6241 zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
6242 nr_zones = build_zonerefs_node(pgdat, zonerefs);
6243 zonerefs += nr_zones;
6244 zonerefs->zone = NULL;
6245 zonerefs->zone_idx = 0;
6249 * Build zonelists ordered by zone and nodes within zones.
6250 * This results in conserving DMA zone[s] until all Normal memory is
6251 * exhausted, but results in overflowing to remote node while memory
6252 * may still exist in local DMA zone.
6255 static void build_zonelists(pg_data_t *pgdat)
6257 static int node_order[MAX_NUMNODES];
6258 int node, load, nr_nodes = 0;
6259 nodemask_t used_mask = NODE_MASK_NONE;
6260 int local_node, prev_node;
6262 /* NUMA-aware ordering of nodes */
6263 local_node = pgdat->node_id;
6264 load = nr_online_nodes;
6265 prev_node = local_node;
6267 memset(node_order, 0, sizeof(node_order));
6268 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
6270 * We don't want to pressure a particular node.
6271 * So adding penalty to the first node in same
6272 * distance group to make it round-robin.
6274 if (node_distance(local_node, node) !=
6275 node_distance(local_node, prev_node))
6276 node_load[node] = load;
6278 node_order[nr_nodes++] = node;
6283 build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
6284 build_thisnode_zonelists(pgdat);
6287 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
6289 * Return node id of node used for "local" allocations.
6290 * I.e., first node id of first zone in arg node's generic zonelist.
6291 * Used for initializing percpu 'numa_mem', which is used primarily
6292 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
6294 int local_memory_node(int node)
6298 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
6299 gfp_zone(GFP_KERNEL),
6301 return zone_to_nid(z->zone);
6305 static void setup_min_unmapped_ratio(void);
6306 static void setup_min_slab_ratio(void);
6307 #else /* CONFIG_NUMA */
6309 static void build_zonelists(pg_data_t *pgdat)
6311 int node, local_node;
6312 struct zoneref *zonerefs;
6315 local_node = pgdat->node_id;
6317 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
6318 nr_zones = build_zonerefs_node(pgdat, zonerefs);
6319 zonerefs += nr_zones;
6322 * Now we build the zonelist so that it contains the zones
6323 * of all the other nodes.
6324 * We don't want to pressure a particular node, so when
6325 * building the zones for node N, we make sure that the
6326 * zones coming right after the local ones are those from
6327 * node N+1 (modulo N)
6329 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
6330 if (!node_online(node))
6332 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
6333 zonerefs += nr_zones;
6335 for (node = 0; node < local_node; node++) {
6336 if (!node_online(node))
6338 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
6339 zonerefs += nr_zones;
6342 zonerefs->zone = NULL;
6343 zonerefs->zone_idx = 0;
6346 #endif /* CONFIG_NUMA */
6349 * Boot pageset table. One per cpu which is going to be used for all
6350 * zones and all nodes. The parameters will be set in such a way
6351 * that an item put on a list will immediately be handed over to
6352 * the buddy list. This is safe since pageset manipulation is done
6353 * with interrupts disabled.
6355 * The boot_pagesets must be kept even after bootup is complete for
6356 * unused processors and/or zones. They do play a role for bootstrapping
6357 * hotplugged processors.
6359 * zoneinfo_show() and maybe other functions do
6360 * not check if the processor is online before following the pageset pointer.
6361 * Other parts of the kernel may not check if the zone is available.
6363 static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats);
6364 /* These effectively disable the pcplists in the boot pageset completely */
6365 #define BOOT_PAGESET_HIGH 0
6366 #define BOOT_PAGESET_BATCH 1
6367 static DEFINE_PER_CPU(struct per_cpu_pages, boot_pageset);
6368 static DEFINE_PER_CPU(struct per_cpu_zonestat, boot_zonestats);
6369 static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
6371 static void __build_all_zonelists(void *data)
6374 int __maybe_unused cpu;
6375 pg_data_t *self = data;
6376 static DEFINE_SPINLOCK(lock);
6381 memset(node_load, 0, sizeof(node_load));
6385 * This node is hotadded and no memory is yet present. So just
6386 * building zonelists is fine - no need to touch other nodes.
6388 if (self && !node_online(self->node_id)) {
6389 build_zonelists(self);
6391 for_each_online_node(nid) {
6392 pg_data_t *pgdat = NODE_DATA(nid);
6394 build_zonelists(pgdat);
6397 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
6399 * We now know the "local memory node" for each node--
6400 * i.e., the node of the first zone in the generic zonelist.
6401 * Set up numa_mem percpu variable for on-line cpus. During
6402 * boot, only the boot cpu should be on-line; we'll init the
6403 * secondary cpus' numa_mem as they come on-line. During
6404 * node/memory hotplug, we'll fixup all on-line cpus.
6406 for_each_online_cpu(cpu)
6407 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
6414 static noinline void __init
6415 build_all_zonelists_init(void)
6419 __build_all_zonelists(NULL);
6422 * Initialize the boot_pagesets that are going to be used
6423 * for bootstrapping processors. The real pagesets for
6424 * each zone will be allocated later when the per cpu
6425 * allocator is available.
6427 * boot_pagesets are used also for bootstrapping offline
6428 * cpus if the system is already booted because the pagesets
6429 * are needed to initialize allocators on a specific cpu too.
6430 * F.e. the percpu allocator needs the page allocator which
6431 * needs the percpu allocator in order to allocate its pagesets
6432 * (a chicken-egg dilemma).
6434 for_each_possible_cpu(cpu)
6435 per_cpu_pages_init(&per_cpu(boot_pageset, cpu), &per_cpu(boot_zonestats, cpu));
6437 mminit_verify_zonelist();
6438 cpuset_init_current_mems_allowed();
6442 * unless system_state == SYSTEM_BOOTING.
6444 * __ref due to call of __init annotated helper build_all_zonelists_init
6445 * [protected by SYSTEM_BOOTING].
6447 void __ref build_all_zonelists(pg_data_t *pgdat)
6449 unsigned long vm_total_pages;
6451 if (system_state == SYSTEM_BOOTING) {
6452 build_all_zonelists_init();
6454 __build_all_zonelists(pgdat);
6455 /* cpuset refresh routine should be here */
6457 /* Get the number of free pages beyond high watermark in all zones. */
6458 vm_total_pages = nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
6460 * Disable grouping by mobility if the number of pages in the
6461 * system is too low to allow the mechanism to work. It would be
6462 * more accurate, but expensive to check per-zone. This check is
6463 * made on memory-hotadd so a system can start with mobility
6464 * disabled and enable it later
6466 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
6467 page_group_by_mobility_disabled = 1;
6469 page_group_by_mobility_disabled = 0;
6471 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
6473 page_group_by_mobility_disabled ? "off" : "on",
6476 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
6480 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
6481 static bool __meminit
6482 overlap_memmap_init(unsigned long zone, unsigned long *pfn)
6484 static struct memblock_region *r;
6486 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
6487 if (!r || *pfn >= memblock_region_memory_end_pfn(r)) {
6488 for_each_mem_region(r) {
6489 if (*pfn < memblock_region_memory_end_pfn(r))
6493 if (*pfn >= memblock_region_memory_base_pfn(r) &&
6494 memblock_is_mirror(r)) {
6495 *pfn = memblock_region_memory_end_pfn(r);
6503 * Initially all pages are reserved - free ones are freed
6504 * up by memblock_free_all() once the early boot process is
6505 * done. Non-atomic initialization, single-pass.
6507 * All aligned pageblocks are initialized to the specified migratetype
6508 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related
6509 * zone stats (e.g., nr_isolate_pageblock) are touched.
6511 void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone,
6512 unsigned long start_pfn, unsigned long zone_end_pfn,
6513 enum meminit_context context,
6514 struct vmem_altmap *altmap, int migratetype)
6516 unsigned long pfn, end_pfn = start_pfn + size;
6519 if (highest_memmap_pfn < end_pfn - 1)
6520 highest_memmap_pfn = end_pfn - 1;
6522 #ifdef CONFIG_ZONE_DEVICE
6524 * Honor reservation requested by the driver for this ZONE_DEVICE
6525 * memory. We limit the total number of pages to initialize to just
6526 * those that might contain the memory mapping. We will defer the
6527 * ZONE_DEVICE page initialization until after we have released
6530 if (zone == ZONE_DEVICE) {
6534 if (start_pfn == altmap->base_pfn)
6535 start_pfn += altmap->reserve;
6536 end_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6540 for (pfn = start_pfn; pfn < end_pfn; ) {
6542 * There can be holes in boot-time mem_map[]s handed to this
6543 * function. They do not exist on hotplugged memory.
6545 if (context == MEMINIT_EARLY) {
6546 if (overlap_memmap_init(zone, &pfn))
6548 if (defer_init(nid, pfn, zone_end_pfn))
6552 page = pfn_to_page(pfn);
6553 __init_single_page(page, pfn, zone, nid);
6554 if (context == MEMINIT_HOTPLUG)
6555 __SetPageReserved(page);
6558 * Usually, we want to mark the pageblock MIGRATE_MOVABLE,
6559 * such that unmovable allocations won't be scattered all
6560 * over the place during system boot.
6562 if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
6563 set_pageblock_migratetype(page, migratetype);
6570 #ifdef CONFIG_ZONE_DEVICE
6571 void __ref memmap_init_zone_device(struct zone *zone,
6572 unsigned long start_pfn,
6573 unsigned long nr_pages,
6574 struct dev_pagemap *pgmap)
6576 unsigned long pfn, end_pfn = start_pfn + nr_pages;
6577 struct pglist_data *pgdat = zone->zone_pgdat;
6578 struct vmem_altmap *altmap = pgmap_altmap(pgmap);
6579 unsigned long zone_idx = zone_idx(zone);
6580 unsigned long start = jiffies;
6581 int nid = pgdat->node_id;
6583 if (WARN_ON_ONCE(!pgmap || zone_idx(zone) != ZONE_DEVICE))
6587 * The call to memmap_init should have already taken care
6588 * of the pages reserved for the memmap, so we can just jump to
6589 * the end of that region and start processing the device pages.
6592 start_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6593 nr_pages = end_pfn - start_pfn;
6596 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
6597 struct page *page = pfn_to_page(pfn);
6599 __init_single_page(page, pfn, zone_idx, nid);
6602 * Mark page reserved as it will need to wait for onlining
6603 * phase for it to be fully associated with a zone.
6605 * We can use the non-atomic __set_bit operation for setting
6606 * the flag as we are still initializing the pages.
6608 __SetPageReserved(page);
6611 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6612 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6613 * ever freed or placed on a driver-private list.
6615 page->pgmap = pgmap;
6616 page->zone_device_data = NULL;
6619 * Mark the block movable so that blocks are reserved for
6620 * movable at startup. This will force kernel allocations
6621 * to reserve their blocks rather than leaking throughout
6622 * the address space during boot when many long-lived
6623 * kernel allocations are made.
6625 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6626 * because this is done early in section_activate()
6628 if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
6629 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
6634 pr_info("%s initialised %lu pages in %ums\n", __func__,
6635 nr_pages, jiffies_to_msecs(jiffies - start));
6639 static void __meminit zone_init_free_lists(struct zone *zone)
6641 unsigned int order, t;
6642 for_each_migratetype_order(order, t) {
6643 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
6644 zone->free_area[order].nr_free = 0;
6649 * Only struct pages that correspond to ranges defined by memblock.memory
6650 * are zeroed and initialized by going through __init_single_page() during
6651 * memmap_init_zone_range().
6653 * But, there could be struct pages that correspond to holes in
6654 * memblock.memory. This can happen because of the following reasons:
6655 * - physical memory bank size is not necessarily the exact multiple of the
6656 * arbitrary section size
6657 * - early reserved memory may not be listed in memblock.memory
6658 * - memory layouts defined with memmap= kernel parameter may not align
6659 * nicely with memmap sections
6661 * Explicitly initialize those struct pages so that:
6662 * - PG_Reserved is set
6663 * - zone and node links point to zone and node that span the page if the
6664 * hole is in the middle of a zone
6665 * - zone and node links point to adjacent zone/node if the hole falls on
6666 * the zone boundary; the pages in such holes will be prepended to the
6667 * zone/node above the hole except for the trailing pages in the last
6668 * section that will be appended to the zone/node below.
6670 static void __init init_unavailable_range(unsigned long spfn,
6677 for (pfn = spfn; pfn < epfn; pfn++) {
6678 if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
6679 pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
6680 + pageblock_nr_pages - 1;
6683 __init_single_page(pfn_to_page(pfn), pfn, zone, node);
6684 __SetPageReserved(pfn_to_page(pfn));
6689 pr_info("On node %d, zone %s: %lld pages in unavailable ranges",
6690 node, zone_names[zone], pgcnt);
6693 static void __init memmap_init_zone_range(struct zone *zone,
6694 unsigned long start_pfn,
6695 unsigned long end_pfn,
6696 unsigned long *hole_pfn)
6698 unsigned long zone_start_pfn = zone->zone_start_pfn;
6699 unsigned long zone_end_pfn = zone_start_pfn + zone->spanned_pages;
6700 int nid = zone_to_nid(zone), zone_id = zone_idx(zone);
6702 start_pfn = clamp(start_pfn, zone_start_pfn, zone_end_pfn);
6703 end_pfn = clamp(end_pfn, zone_start_pfn, zone_end_pfn);
6705 if (start_pfn >= end_pfn)
6708 memmap_init_range(end_pfn - start_pfn, nid, zone_id, start_pfn,
6709 zone_end_pfn, MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
6711 if (*hole_pfn < start_pfn)
6712 init_unavailable_range(*hole_pfn, start_pfn, zone_id, nid);
6714 *hole_pfn = end_pfn;
6717 static void __init memmap_init(void)
6719 unsigned long start_pfn, end_pfn;
6720 unsigned long hole_pfn = 0;
6721 int i, j, zone_id = 0, nid;
6723 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6724 struct pglist_data *node = NODE_DATA(nid);
6726 for (j = 0; j < MAX_NR_ZONES; j++) {
6727 struct zone *zone = node->node_zones + j;
6729 if (!populated_zone(zone))
6732 memmap_init_zone_range(zone, start_pfn, end_pfn,
6738 #ifdef CONFIG_SPARSEMEM
6740 * Initialize the memory map for hole in the range [memory_end,
6742 * Append the pages in this hole to the highest zone in the last
6744 * The call to init_unavailable_range() is outside the ifdef to
6745 * silence the compiler warining about zone_id set but not used;
6746 * for FLATMEM it is a nop anyway
6748 end_pfn = round_up(end_pfn, PAGES_PER_SECTION);
6749 if (hole_pfn < end_pfn)
6751 init_unavailable_range(hole_pfn, end_pfn, zone_id, nid);
6754 void __init *memmap_alloc(phys_addr_t size, phys_addr_t align,
6755 phys_addr_t min_addr, int nid, bool exact_nid)
6760 ptr = memblock_alloc_exact_nid_raw(size, align, min_addr,
6761 MEMBLOCK_ALLOC_ACCESSIBLE,
6764 ptr = memblock_alloc_try_nid_raw(size, align, min_addr,
6765 MEMBLOCK_ALLOC_ACCESSIBLE,
6768 if (ptr && size > 0)
6769 page_init_poison(ptr, size);
6774 static int zone_batchsize(struct zone *zone)
6780 * The number of pages to batch allocate is either ~0.1%
6781 * of the zone or 1MB, whichever is smaller. The batch
6782 * size is striking a balance between allocation latency
6783 * and zone lock contention.
6785 batch = min(zone_managed_pages(zone) >> 10, (1024 * 1024) / PAGE_SIZE);
6786 batch /= 4; /* We effectively *= 4 below */
6791 * Clamp the batch to a 2^n - 1 value. Having a power
6792 * of 2 value was found to be more likely to have
6793 * suboptimal cache aliasing properties in some cases.
6795 * For example if 2 tasks are alternately allocating
6796 * batches of pages, one task can end up with a lot
6797 * of pages of one half of the possible page colors
6798 * and the other with pages of the other colors.
6800 batch = rounddown_pow_of_two(batch + batch/2) - 1;
6805 /* The deferral and batching of frees should be suppressed under NOMMU
6808 * The problem is that NOMMU needs to be able to allocate large chunks
6809 * of contiguous memory as there's no hardware page translation to
6810 * assemble apparent contiguous memory from discontiguous pages.
6812 * Queueing large contiguous runs of pages for batching, however,
6813 * causes the pages to actually be freed in smaller chunks. As there
6814 * can be a significant delay between the individual batches being
6815 * recycled, this leads to the once large chunks of space being
6816 * fragmented and becoming unavailable for high-order allocations.
6822 static int zone_highsize(struct zone *zone, int batch, int cpu_online)
6827 unsigned long total_pages;
6829 if (!percpu_pagelist_high_fraction) {
6831 * By default, the high value of the pcp is based on the zone
6832 * low watermark so that if they are full then background
6833 * reclaim will not be started prematurely.
6835 total_pages = low_wmark_pages(zone);
6838 * If percpu_pagelist_high_fraction is configured, the high
6839 * value is based on a fraction of the managed pages in the
6842 total_pages = zone_managed_pages(zone) / percpu_pagelist_high_fraction;
6846 * Split the high value across all online CPUs local to the zone. Note
6847 * that early in boot that CPUs may not be online yet and that during
6848 * CPU hotplug that the cpumask is not yet updated when a CPU is being
6849 * onlined. For memory nodes that have no CPUs, split pcp->high across
6850 * all online CPUs to mitigate the risk that reclaim is triggered
6851 * prematurely due to pages stored on pcp lists.
6853 nr_split_cpus = cpumask_weight(cpumask_of_node(zone_to_nid(zone))) + cpu_online;
6855 nr_split_cpus = num_online_cpus();
6856 high = total_pages / nr_split_cpus;
6859 * Ensure high is at least batch*4. The multiple is based on the
6860 * historical relationship between high and batch.
6862 high = max(high, batch << 2);
6871 * pcp->high and pcp->batch values are related and generally batch is lower
6872 * than high. They are also related to pcp->count such that count is lower
6873 * than high, and as soon as it reaches high, the pcplist is flushed.
6875 * However, guaranteeing these relations at all times would require e.g. write
6876 * barriers here but also careful usage of read barriers at the read side, and
6877 * thus be prone to error and bad for performance. Thus the update only prevents
6878 * store tearing. Any new users of pcp->batch and pcp->high should ensure they
6879 * can cope with those fields changing asynchronously, and fully trust only the
6880 * pcp->count field on the local CPU with interrupts disabled.
6882 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6883 * outside of boot time (or some other assurance that no concurrent updaters
6886 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
6887 unsigned long batch)
6889 WRITE_ONCE(pcp->batch, batch);
6890 WRITE_ONCE(pcp->high, high);
6893 static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats)
6897 memset(pcp, 0, sizeof(*pcp));
6898 memset(pzstats, 0, sizeof(*pzstats));
6900 for (pindex = 0; pindex < NR_PCP_LISTS; pindex++)
6901 INIT_LIST_HEAD(&pcp->lists[pindex]);
6904 * Set batch and high values safe for a boot pageset. A true percpu
6905 * pageset's initialization will update them subsequently. Here we don't
6906 * need to be as careful as pageset_update() as nobody can access the
6909 pcp->high = BOOT_PAGESET_HIGH;
6910 pcp->batch = BOOT_PAGESET_BATCH;
6911 pcp->free_factor = 0;
6914 static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high,
6915 unsigned long batch)
6917 struct per_cpu_pages *pcp;
6920 for_each_possible_cpu(cpu) {
6921 pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
6922 pageset_update(pcp, high, batch);
6927 * Calculate and set new high and batch values for all per-cpu pagesets of a
6928 * zone based on the zone's size.
6930 static void zone_set_pageset_high_and_batch(struct zone *zone, int cpu_online)
6932 int new_high, new_batch;
6934 new_batch = max(1, zone_batchsize(zone));
6935 new_high = zone_highsize(zone, new_batch, cpu_online);
6937 if (zone->pageset_high == new_high &&
6938 zone->pageset_batch == new_batch)
6941 zone->pageset_high = new_high;
6942 zone->pageset_batch = new_batch;
6944 __zone_set_pageset_high_and_batch(zone, new_high, new_batch);
6947 void __meminit setup_zone_pageset(struct zone *zone)
6951 /* Size may be 0 on !SMP && !NUMA */
6952 if (sizeof(struct per_cpu_zonestat) > 0)
6953 zone->per_cpu_zonestats = alloc_percpu(struct per_cpu_zonestat);
6955 zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages);
6956 for_each_possible_cpu(cpu) {
6957 struct per_cpu_pages *pcp;
6958 struct per_cpu_zonestat *pzstats;
6960 pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
6961 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
6962 per_cpu_pages_init(pcp, pzstats);
6965 zone_set_pageset_high_and_batch(zone, 0);
6969 * Allocate per cpu pagesets and initialize them.
6970 * Before this call only boot pagesets were available.
6972 void __init setup_per_cpu_pageset(void)
6974 struct pglist_data *pgdat;
6976 int __maybe_unused cpu;
6978 for_each_populated_zone(zone)
6979 setup_zone_pageset(zone);
6983 * Unpopulated zones continue using the boot pagesets.
6984 * The numa stats for these pagesets need to be reset.
6985 * Otherwise, they will end up skewing the stats of
6986 * the nodes these zones are associated with.
6988 for_each_possible_cpu(cpu) {
6989 struct per_cpu_zonestat *pzstats = &per_cpu(boot_zonestats, cpu);
6990 memset(pzstats->vm_numa_event, 0,
6991 sizeof(pzstats->vm_numa_event));
6995 for_each_online_pgdat(pgdat)
6996 pgdat->per_cpu_nodestats =
6997 alloc_percpu(struct per_cpu_nodestat);
7000 static __meminit void zone_pcp_init(struct zone *zone)
7003 * per cpu subsystem is not up at this point. The following code
7004 * relies on the ability of the linker to provide the
7005 * offset of a (static) per cpu variable into the per cpu area.
7007 zone->per_cpu_pageset = &boot_pageset;
7008 zone->per_cpu_zonestats = &boot_zonestats;
7009 zone->pageset_high = BOOT_PAGESET_HIGH;
7010 zone->pageset_batch = BOOT_PAGESET_BATCH;
7012 if (populated_zone(zone))
7013 pr_debug(" %s zone: %lu pages, LIFO batch:%u\n", zone->name,
7014 zone->present_pages, zone_batchsize(zone));
7017 void __meminit init_currently_empty_zone(struct zone *zone,
7018 unsigned long zone_start_pfn,
7021 struct pglist_data *pgdat = zone->zone_pgdat;
7022 int zone_idx = zone_idx(zone) + 1;
7024 if (zone_idx > pgdat->nr_zones)
7025 pgdat->nr_zones = zone_idx;
7027 zone->zone_start_pfn = zone_start_pfn;
7029 mminit_dprintk(MMINIT_TRACE, "memmap_init",
7030 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
7032 (unsigned long)zone_idx(zone),
7033 zone_start_pfn, (zone_start_pfn + size));
7035 zone_init_free_lists(zone);
7036 zone->initialized = 1;
7040 * get_pfn_range_for_nid - Return the start and end page frames for a node
7041 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
7042 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
7043 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
7045 * It returns the start and end page frame of a node based on information
7046 * provided by memblock_set_node(). If called for a node
7047 * with no available memory, a warning is printed and the start and end
7050 void __init get_pfn_range_for_nid(unsigned int nid,
7051 unsigned long *start_pfn, unsigned long *end_pfn)
7053 unsigned long this_start_pfn, this_end_pfn;
7059 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
7060 *start_pfn = min(*start_pfn, this_start_pfn);
7061 *end_pfn = max(*end_pfn, this_end_pfn);
7064 if (*start_pfn == -1UL)
7069 * This finds a zone that can be used for ZONE_MOVABLE pages. The
7070 * assumption is made that zones within a node are ordered in monotonic
7071 * increasing memory addresses so that the "highest" populated zone is used
7073 static void __init find_usable_zone_for_movable(void)
7076 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
7077 if (zone_index == ZONE_MOVABLE)
7080 if (arch_zone_highest_possible_pfn[zone_index] >
7081 arch_zone_lowest_possible_pfn[zone_index])
7085 VM_BUG_ON(zone_index == -1);
7086 movable_zone = zone_index;
7090 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
7091 * because it is sized independent of architecture. Unlike the other zones,
7092 * the starting point for ZONE_MOVABLE is not fixed. It may be different
7093 * in each node depending on the size of each node and how evenly kernelcore
7094 * is distributed. This helper function adjusts the zone ranges
7095 * provided by the architecture for a given node by using the end of the
7096 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
7097 * zones within a node are in order of monotonic increases memory addresses
7099 static void __init adjust_zone_range_for_zone_movable(int nid,
7100 unsigned long zone_type,
7101 unsigned long node_start_pfn,
7102 unsigned long node_end_pfn,
7103 unsigned long *zone_start_pfn,
7104 unsigned long *zone_end_pfn)
7106 /* Only adjust if ZONE_MOVABLE is on this node */
7107 if (zone_movable_pfn[nid]) {
7108 /* Size ZONE_MOVABLE */
7109 if (zone_type == ZONE_MOVABLE) {
7110 *zone_start_pfn = zone_movable_pfn[nid];
7111 *zone_end_pfn = min(node_end_pfn,
7112 arch_zone_highest_possible_pfn[movable_zone]);
7114 /* Adjust for ZONE_MOVABLE starting within this range */
7115 } else if (!mirrored_kernelcore &&
7116 *zone_start_pfn < zone_movable_pfn[nid] &&
7117 *zone_end_pfn > zone_movable_pfn[nid]) {
7118 *zone_end_pfn = zone_movable_pfn[nid];
7120 /* Check if this whole range is within ZONE_MOVABLE */
7121 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
7122 *zone_start_pfn = *zone_end_pfn;
7127 * Return the number of pages a zone spans in a node, including holes
7128 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
7130 static unsigned long __init zone_spanned_pages_in_node(int nid,
7131 unsigned long zone_type,
7132 unsigned long node_start_pfn,
7133 unsigned long node_end_pfn,
7134 unsigned long *zone_start_pfn,
7135 unsigned long *zone_end_pfn)
7137 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
7138 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
7139 /* When hotadd a new node from cpu_up(), the node should be empty */
7140 if (!node_start_pfn && !node_end_pfn)
7143 /* Get the start and end of the zone */
7144 *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
7145 *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
7146 adjust_zone_range_for_zone_movable(nid, zone_type,
7147 node_start_pfn, node_end_pfn,
7148 zone_start_pfn, zone_end_pfn);
7150 /* Check that this node has pages within the zone's required range */
7151 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
7154 /* Move the zone boundaries inside the node if necessary */
7155 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
7156 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
7158 /* Return the spanned pages */
7159 return *zone_end_pfn - *zone_start_pfn;
7163 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
7164 * then all holes in the requested range will be accounted for.
7166 unsigned long __init __absent_pages_in_range(int nid,
7167 unsigned long range_start_pfn,
7168 unsigned long range_end_pfn)
7170 unsigned long nr_absent = range_end_pfn - range_start_pfn;
7171 unsigned long start_pfn, end_pfn;
7174 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
7175 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
7176 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
7177 nr_absent -= end_pfn - start_pfn;
7183 * absent_pages_in_range - Return number of page frames in holes within a range
7184 * @start_pfn: The start PFN to start searching for holes
7185 * @end_pfn: The end PFN to stop searching for holes
7187 * Return: the number of pages frames in memory holes within a range.
7189 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
7190 unsigned long end_pfn)
7192 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
7195 /* Return the number of page frames in holes in a zone on a node */
7196 static unsigned long __init zone_absent_pages_in_node(int nid,
7197 unsigned long zone_type,
7198 unsigned long node_start_pfn,
7199 unsigned long node_end_pfn)
7201 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
7202 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
7203 unsigned long zone_start_pfn, zone_end_pfn;
7204 unsigned long nr_absent;
7206 /* When hotadd a new node from cpu_up(), the node should be empty */
7207 if (!node_start_pfn && !node_end_pfn)
7210 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
7211 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
7213 adjust_zone_range_for_zone_movable(nid, zone_type,
7214 node_start_pfn, node_end_pfn,
7215 &zone_start_pfn, &zone_end_pfn);
7216 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
7219 * ZONE_MOVABLE handling.
7220 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
7223 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
7224 unsigned long start_pfn, end_pfn;
7225 struct memblock_region *r;
7227 for_each_mem_region(r) {
7228 start_pfn = clamp(memblock_region_memory_base_pfn(r),
7229 zone_start_pfn, zone_end_pfn);
7230 end_pfn = clamp(memblock_region_memory_end_pfn(r),
7231 zone_start_pfn, zone_end_pfn);
7233 if (zone_type == ZONE_MOVABLE &&
7234 memblock_is_mirror(r))
7235 nr_absent += end_pfn - start_pfn;
7237 if (zone_type == ZONE_NORMAL &&
7238 !memblock_is_mirror(r))
7239 nr_absent += end_pfn - start_pfn;
7246 static void __init calculate_node_totalpages(struct pglist_data *pgdat,
7247 unsigned long node_start_pfn,
7248 unsigned long node_end_pfn)
7250 unsigned long realtotalpages = 0, totalpages = 0;
7253 for (i = 0; i < MAX_NR_ZONES; i++) {
7254 struct zone *zone = pgdat->node_zones + i;
7255 unsigned long zone_start_pfn, zone_end_pfn;
7256 unsigned long spanned, absent;
7257 unsigned long size, real_size;
7259 spanned = zone_spanned_pages_in_node(pgdat->node_id, i,
7264 absent = zone_absent_pages_in_node(pgdat->node_id, i,
7269 real_size = size - absent;
7272 zone->zone_start_pfn = zone_start_pfn;
7274 zone->zone_start_pfn = 0;
7275 zone->spanned_pages = size;
7276 zone->present_pages = real_size;
7277 #if defined(CONFIG_MEMORY_HOTPLUG)
7278 zone->present_early_pages = real_size;
7282 realtotalpages += real_size;
7285 pgdat->node_spanned_pages = totalpages;
7286 pgdat->node_present_pages = realtotalpages;
7287 pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
7290 #ifndef CONFIG_SPARSEMEM
7292 * Calculate the size of the zone->blockflags rounded to an unsigned long
7293 * Start by making sure zonesize is a multiple of pageblock_order by rounding
7294 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
7295 * round what is now in bits to nearest long in bits, then return it in
7298 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
7300 unsigned long usemapsize;
7302 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
7303 usemapsize = roundup(zonesize, pageblock_nr_pages);
7304 usemapsize = usemapsize >> pageblock_order;
7305 usemapsize *= NR_PAGEBLOCK_BITS;
7306 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
7308 return usemapsize / 8;
7311 static void __ref setup_usemap(struct zone *zone)
7313 unsigned long usemapsize = usemap_size(zone->zone_start_pfn,
7314 zone->spanned_pages);
7315 zone->pageblock_flags = NULL;
7317 zone->pageblock_flags =
7318 memblock_alloc_node(usemapsize, SMP_CACHE_BYTES,
7320 if (!zone->pageblock_flags)
7321 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
7322 usemapsize, zone->name, zone_to_nid(zone));
7326 static inline void setup_usemap(struct zone *zone) {}
7327 #endif /* CONFIG_SPARSEMEM */
7329 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
7331 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
7332 void __init set_pageblock_order(void)
7336 /* Check that pageblock_nr_pages has not already been setup */
7337 if (pageblock_order)
7340 if (HPAGE_SHIFT > PAGE_SHIFT)
7341 order = HUGETLB_PAGE_ORDER;
7343 order = MAX_ORDER - 1;
7346 * Assume the largest contiguous order of interest is a huge page.
7347 * This value may be variable depending on boot parameters on IA64 and
7350 pageblock_order = order;
7352 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
7355 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
7356 * is unused as pageblock_order is set at compile-time. See
7357 * include/linux/pageblock-flags.h for the values of pageblock_order based on
7360 void __init set_pageblock_order(void)
7364 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
7366 static unsigned long __init calc_memmap_size(unsigned long spanned_pages,
7367 unsigned long present_pages)
7369 unsigned long pages = spanned_pages;
7372 * Provide a more accurate estimation if there are holes within
7373 * the zone and SPARSEMEM is in use. If there are holes within the
7374 * zone, each populated memory region may cost us one or two extra
7375 * memmap pages due to alignment because memmap pages for each
7376 * populated regions may not be naturally aligned on page boundary.
7377 * So the (present_pages >> 4) heuristic is a tradeoff for that.
7379 if (spanned_pages > present_pages + (present_pages >> 4) &&
7380 IS_ENABLED(CONFIG_SPARSEMEM))
7381 pages = present_pages;
7383 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
7386 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
7387 static void pgdat_init_split_queue(struct pglist_data *pgdat)
7389 struct deferred_split *ds_queue = &pgdat->deferred_split_queue;
7391 spin_lock_init(&ds_queue->split_queue_lock);
7392 INIT_LIST_HEAD(&ds_queue->split_queue);
7393 ds_queue->split_queue_len = 0;
7396 static void pgdat_init_split_queue(struct pglist_data *pgdat) {}
7399 #ifdef CONFIG_COMPACTION
7400 static void pgdat_init_kcompactd(struct pglist_data *pgdat)
7402 init_waitqueue_head(&pgdat->kcompactd_wait);
7405 static void pgdat_init_kcompactd(struct pglist_data *pgdat) {}
7408 static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
7410 pgdat_resize_init(pgdat);
7412 pgdat_init_split_queue(pgdat);
7413 pgdat_init_kcompactd(pgdat);
7415 init_waitqueue_head(&pgdat->kswapd_wait);
7416 init_waitqueue_head(&pgdat->pfmemalloc_wait);
7418 pgdat_page_ext_init(pgdat);
7419 lruvec_init(&pgdat->__lruvec);
7422 static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,
7423 unsigned long remaining_pages)
7425 atomic_long_set(&zone->managed_pages, remaining_pages);
7426 zone_set_nid(zone, nid);
7427 zone->name = zone_names[idx];
7428 zone->zone_pgdat = NODE_DATA(nid);
7429 spin_lock_init(&zone->lock);
7430 zone_seqlock_init(zone);
7431 zone_pcp_init(zone);
7435 * Set up the zone data structures
7436 * - init pgdat internals
7437 * - init all zones belonging to this node
7439 * NOTE: this function is only called during memory hotplug
7441 #ifdef CONFIG_MEMORY_HOTPLUG
7442 void __ref free_area_init_core_hotplug(int nid)
7445 pg_data_t *pgdat = NODE_DATA(nid);
7447 pgdat_init_internals(pgdat);
7448 for (z = 0; z < MAX_NR_ZONES; z++)
7449 zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
7454 * Set up the zone data structures:
7455 * - mark all pages reserved
7456 * - mark all memory queues empty
7457 * - clear the memory bitmaps
7459 * NOTE: pgdat should get zeroed by caller.
7460 * NOTE: this function is only called during early init.
7462 static void __init free_area_init_core(struct pglist_data *pgdat)
7465 int nid = pgdat->node_id;
7467 pgdat_init_internals(pgdat);
7468 pgdat->per_cpu_nodestats = &boot_nodestats;
7470 for (j = 0; j < MAX_NR_ZONES; j++) {
7471 struct zone *zone = pgdat->node_zones + j;
7472 unsigned long size, freesize, memmap_pages;
7474 size = zone->spanned_pages;
7475 freesize = zone->present_pages;
7478 * Adjust freesize so that it accounts for how much memory
7479 * is used by this zone for memmap. This affects the watermark
7480 * and per-cpu initialisations
7482 memmap_pages = calc_memmap_size(size, freesize);
7483 if (!is_highmem_idx(j)) {
7484 if (freesize >= memmap_pages) {
7485 freesize -= memmap_pages;
7487 pr_debug(" %s zone: %lu pages used for memmap\n",
7488 zone_names[j], memmap_pages);
7490 pr_warn(" %s zone: %lu memmap pages exceeds freesize %lu\n",
7491 zone_names[j], memmap_pages, freesize);
7494 /* Account for reserved pages */
7495 if (j == 0 && freesize > dma_reserve) {
7496 freesize -= dma_reserve;
7497 pr_debug(" %s zone: %lu pages reserved\n", zone_names[0], dma_reserve);
7500 if (!is_highmem_idx(j))
7501 nr_kernel_pages += freesize;
7502 /* Charge for highmem memmap if there are enough kernel pages */
7503 else if (nr_kernel_pages > memmap_pages * 2)
7504 nr_kernel_pages -= memmap_pages;
7505 nr_all_pages += freesize;
7508 * Set an approximate value for lowmem here, it will be adjusted
7509 * when the bootmem allocator frees pages into the buddy system.
7510 * And all highmem pages will be managed by the buddy system.
7512 zone_init_internals(zone, j, nid, freesize);
7517 set_pageblock_order();
7519 init_currently_empty_zone(zone, zone->zone_start_pfn, size);
7523 #ifdef CONFIG_FLATMEM
7524 static void __init alloc_node_mem_map(struct pglist_data *pgdat)
7526 unsigned long __maybe_unused start = 0;
7527 unsigned long __maybe_unused offset = 0;
7529 /* Skip empty nodes */
7530 if (!pgdat->node_spanned_pages)
7533 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
7534 offset = pgdat->node_start_pfn - start;
7535 /* ia64 gets its own node_mem_map, before this, without bootmem */
7536 if (!pgdat->node_mem_map) {
7537 unsigned long size, end;
7541 * The zone's endpoints aren't required to be MAX_ORDER
7542 * aligned but the node_mem_map endpoints must be in order
7543 * for the buddy allocator to function correctly.
7545 end = pgdat_end_pfn(pgdat);
7546 end = ALIGN(end, MAX_ORDER_NR_PAGES);
7547 size = (end - start) * sizeof(struct page);
7548 map = memmap_alloc(size, SMP_CACHE_BYTES, MEMBLOCK_LOW_LIMIT,
7549 pgdat->node_id, false);
7551 panic("Failed to allocate %ld bytes for node %d memory map\n",
7552 size, pgdat->node_id);
7553 pgdat->node_mem_map = map + offset;
7555 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
7556 __func__, pgdat->node_id, (unsigned long)pgdat,
7557 (unsigned long)pgdat->node_mem_map);
7560 * With no DISCONTIG, the global mem_map is just set as node 0's
7562 if (pgdat == NODE_DATA(0)) {
7563 mem_map = NODE_DATA(0)->node_mem_map;
7564 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
7570 static inline void alloc_node_mem_map(struct pglist_data *pgdat) { }
7571 #endif /* CONFIG_FLATMEM */
7573 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
7574 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
7576 pgdat->first_deferred_pfn = ULONG_MAX;
7579 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
7582 static void __init free_area_init_node(int nid)
7584 pg_data_t *pgdat = NODE_DATA(nid);
7585 unsigned long start_pfn = 0;
7586 unsigned long end_pfn = 0;
7588 /* pg_data_t should be reset to zero when it's allocated */
7589 WARN_ON(pgdat->nr_zones || pgdat->kswapd_highest_zoneidx);
7591 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
7593 pgdat->node_id = nid;
7594 pgdat->node_start_pfn = start_pfn;
7595 pgdat->per_cpu_nodestats = NULL;
7597 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
7598 (u64)start_pfn << PAGE_SHIFT,
7599 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
7600 calculate_node_totalpages(pgdat, start_pfn, end_pfn);
7602 alloc_node_mem_map(pgdat);
7603 pgdat_set_deferred_range(pgdat);
7605 free_area_init_core(pgdat);
7608 void __init free_area_init_memoryless_node(int nid)
7610 free_area_init_node(nid);
7613 #if MAX_NUMNODES > 1
7615 * Figure out the number of possible node ids.
7617 void __init setup_nr_node_ids(void)
7619 unsigned int highest;
7621 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
7622 nr_node_ids = highest + 1;
7627 * node_map_pfn_alignment - determine the maximum internode alignment
7629 * This function should be called after node map is populated and sorted.
7630 * It calculates the maximum power of two alignment which can distinguish
7633 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7634 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7635 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7636 * shifted, 1GiB is enough and this function will indicate so.
7638 * This is used to test whether pfn -> nid mapping of the chosen memory
7639 * model has fine enough granularity to avoid incorrect mapping for the
7640 * populated node map.
7642 * Return: the determined alignment in pfn's. 0 if there is no alignment
7643 * requirement (single node).
7645 unsigned long __init node_map_pfn_alignment(void)
7647 unsigned long accl_mask = 0, last_end = 0;
7648 unsigned long start, end, mask;
7649 int last_nid = NUMA_NO_NODE;
7652 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
7653 if (!start || last_nid < 0 || last_nid == nid) {
7660 * Start with a mask granular enough to pin-point to the
7661 * start pfn and tick off bits one-by-one until it becomes
7662 * too coarse to separate the current node from the last.
7664 mask = ~((1 << __ffs(start)) - 1);
7665 while (mask && last_end <= (start & (mask << 1)))
7668 /* accumulate all internode masks */
7672 /* convert mask to number of pages */
7673 return ~accl_mask + 1;
7677 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7679 * Return: the minimum PFN based on information provided via
7680 * memblock_set_node().
7682 unsigned long __init find_min_pfn_with_active_regions(void)
7684 return PHYS_PFN(memblock_start_of_DRAM());
7688 * early_calculate_totalpages()
7689 * Sum pages in active regions for movable zone.
7690 * Populate N_MEMORY for calculating usable_nodes.
7692 static unsigned long __init early_calculate_totalpages(void)
7694 unsigned long totalpages = 0;
7695 unsigned long start_pfn, end_pfn;
7698 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7699 unsigned long pages = end_pfn - start_pfn;
7701 totalpages += pages;
7703 node_set_state(nid, N_MEMORY);
7709 * Find the PFN the Movable zone begins in each node. Kernel memory
7710 * is spread evenly between nodes as long as the nodes have enough
7711 * memory. When they don't, some nodes will have more kernelcore than
7714 static void __init find_zone_movable_pfns_for_nodes(void)
7717 unsigned long usable_startpfn;
7718 unsigned long kernelcore_node, kernelcore_remaining;
7719 /* save the state before borrow the nodemask */
7720 nodemask_t saved_node_state = node_states[N_MEMORY];
7721 unsigned long totalpages = early_calculate_totalpages();
7722 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
7723 struct memblock_region *r;
7725 /* Need to find movable_zone earlier when movable_node is specified. */
7726 find_usable_zone_for_movable();
7729 * If movable_node is specified, ignore kernelcore and movablecore
7732 if (movable_node_is_enabled()) {
7733 for_each_mem_region(r) {
7734 if (!memblock_is_hotpluggable(r))
7737 nid = memblock_get_region_node(r);
7739 usable_startpfn = PFN_DOWN(r->base);
7740 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7741 min(usable_startpfn, zone_movable_pfn[nid]) :
7749 * If kernelcore=mirror is specified, ignore movablecore option
7751 if (mirrored_kernelcore) {
7752 bool mem_below_4gb_not_mirrored = false;
7754 for_each_mem_region(r) {
7755 if (memblock_is_mirror(r))
7758 nid = memblock_get_region_node(r);
7760 usable_startpfn = memblock_region_memory_base_pfn(r);
7762 if (usable_startpfn < 0x100000) {
7763 mem_below_4gb_not_mirrored = true;
7767 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7768 min(usable_startpfn, zone_movable_pfn[nid]) :
7772 if (mem_below_4gb_not_mirrored)
7773 pr_warn("This configuration results in unmirrored kernel memory.\n");
7779 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7780 * amount of necessary memory.
7782 if (required_kernelcore_percent)
7783 required_kernelcore = (totalpages * 100 * required_kernelcore_percent) /
7785 if (required_movablecore_percent)
7786 required_movablecore = (totalpages * 100 * required_movablecore_percent) /
7790 * If movablecore= was specified, calculate what size of
7791 * kernelcore that corresponds so that memory usable for
7792 * any allocation type is evenly spread. If both kernelcore
7793 * and movablecore are specified, then the value of kernelcore
7794 * will be used for required_kernelcore if it's greater than
7795 * what movablecore would have allowed.
7797 if (required_movablecore) {
7798 unsigned long corepages;
7801 * Round-up so that ZONE_MOVABLE is at least as large as what
7802 * was requested by the user
7804 required_movablecore =
7805 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
7806 required_movablecore = min(totalpages, required_movablecore);
7807 corepages = totalpages - required_movablecore;
7809 required_kernelcore = max(required_kernelcore, corepages);
7813 * If kernelcore was not specified or kernelcore size is larger
7814 * than totalpages, there is no ZONE_MOVABLE.
7816 if (!required_kernelcore || required_kernelcore >= totalpages)
7819 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7820 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
7823 /* Spread kernelcore memory as evenly as possible throughout nodes */
7824 kernelcore_node = required_kernelcore / usable_nodes;
7825 for_each_node_state(nid, N_MEMORY) {
7826 unsigned long start_pfn, end_pfn;
7829 * Recalculate kernelcore_node if the division per node
7830 * now exceeds what is necessary to satisfy the requested
7831 * amount of memory for the kernel
7833 if (required_kernelcore < kernelcore_node)
7834 kernelcore_node = required_kernelcore / usable_nodes;
7837 * As the map is walked, we track how much memory is usable
7838 * by the kernel using kernelcore_remaining. When it is
7839 * 0, the rest of the node is usable by ZONE_MOVABLE
7841 kernelcore_remaining = kernelcore_node;
7843 /* Go through each range of PFNs within this node */
7844 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
7845 unsigned long size_pages;
7847 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
7848 if (start_pfn >= end_pfn)
7851 /* Account for what is only usable for kernelcore */
7852 if (start_pfn < usable_startpfn) {
7853 unsigned long kernel_pages;
7854 kernel_pages = min(end_pfn, usable_startpfn)
7857 kernelcore_remaining -= min(kernel_pages,
7858 kernelcore_remaining);
7859 required_kernelcore -= min(kernel_pages,
7860 required_kernelcore);
7862 /* Continue if range is now fully accounted */
7863 if (end_pfn <= usable_startpfn) {
7866 * Push zone_movable_pfn to the end so
7867 * that if we have to rebalance
7868 * kernelcore across nodes, we will
7869 * not double account here
7871 zone_movable_pfn[nid] = end_pfn;
7874 start_pfn = usable_startpfn;
7878 * The usable PFN range for ZONE_MOVABLE is from
7879 * start_pfn->end_pfn. Calculate size_pages as the
7880 * number of pages used as kernelcore
7882 size_pages = end_pfn - start_pfn;
7883 if (size_pages > kernelcore_remaining)
7884 size_pages = kernelcore_remaining;
7885 zone_movable_pfn[nid] = start_pfn + size_pages;
7888 * Some kernelcore has been met, update counts and
7889 * break if the kernelcore for this node has been
7892 required_kernelcore -= min(required_kernelcore,
7894 kernelcore_remaining -= size_pages;
7895 if (!kernelcore_remaining)
7901 * If there is still required_kernelcore, we do another pass with one
7902 * less node in the count. This will push zone_movable_pfn[nid] further
7903 * along on the nodes that still have memory until kernelcore is
7907 if (usable_nodes && required_kernelcore > usable_nodes)
7911 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7912 for (nid = 0; nid < MAX_NUMNODES; nid++)
7913 zone_movable_pfn[nid] =
7914 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
7917 /* restore the node_state */
7918 node_states[N_MEMORY] = saved_node_state;
7921 /* Any regular or high memory on that node ? */
7922 static void check_for_memory(pg_data_t *pgdat, int nid)
7924 enum zone_type zone_type;
7926 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
7927 struct zone *zone = &pgdat->node_zones[zone_type];
7928 if (populated_zone(zone)) {
7929 if (IS_ENABLED(CONFIG_HIGHMEM))
7930 node_set_state(nid, N_HIGH_MEMORY);
7931 if (zone_type <= ZONE_NORMAL)
7932 node_set_state(nid, N_NORMAL_MEMORY);
7939 * Some architectures, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7940 * such cases we allow max_zone_pfn sorted in the descending order
7942 bool __weak arch_has_descending_max_zone_pfns(void)
7948 * free_area_init - Initialise all pg_data_t and zone data
7949 * @max_zone_pfn: an array of max PFNs for each zone
7951 * This will call free_area_init_node() for each active node in the system.
7952 * Using the page ranges provided by memblock_set_node(), the size of each
7953 * zone in each node and their holes is calculated. If the maximum PFN
7954 * between two adjacent zones match, it is assumed that the zone is empty.
7955 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7956 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7957 * starts where the previous one ended. For example, ZONE_DMA32 starts
7958 * at arch_max_dma_pfn.
7960 void __init free_area_init(unsigned long *max_zone_pfn)
7962 unsigned long start_pfn, end_pfn;
7966 /* Record where the zone boundaries are */
7967 memset(arch_zone_lowest_possible_pfn, 0,
7968 sizeof(arch_zone_lowest_possible_pfn));
7969 memset(arch_zone_highest_possible_pfn, 0,
7970 sizeof(arch_zone_highest_possible_pfn));
7972 start_pfn = find_min_pfn_with_active_regions();
7973 descending = arch_has_descending_max_zone_pfns();
7975 for (i = 0; i < MAX_NR_ZONES; i++) {
7977 zone = MAX_NR_ZONES - i - 1;
7981 if (zone == ZONE_MOVABLE)
7984 end_pfn = max(max_zone_pfn[zone], start_pfn);
7985 arch_zone_lowest_possible_pfn[zone] = start_pfn;
7986 arch_zone_highest_possible_pfn[zone] = end_pfn;
7988 start_pfn = end_pfn;
7991 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7992 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
7993 find_zone_movable_pfns_for_nodes();
7995 /* Print out the zone ranges */
7996 pr_info("Zone ranges:\n");
7997 for (i = 0; i < MAX_NR_ZONES; i++) {
7998 if (i == ZONE_MOVABLE)
8000 pr_info(" %-8s ", zone_names[i]);
8001 if (arch_zone_lowest_possible_pfn[i] ==
8002 arch_zone_highest_possible_pfn[i])
8005 pr_cont("[mem %#018Lx-%#018Lx]\n",
8006 (u64)arch_zone_lowest_possible_pfn[i]
8008 ((u64)arch_zone_highest_possible_pfn[i]
8009 << PAGE_SHIFT) - 1);
8012 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
8013 pr_info("Movable zone start for each node\n");
8014 for (i = 0; i < MAX_NUMNODES; i++) {
8015 if (zone_movable_pfn[i])
8016 pr_info(" Node %d: %#018Lx\n", i,
8017 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
8021 * Print out the early node map, and initialize the
8022 * subsection-map relative to active online memory ranges to
8023 * enable future "sub-section" extensions of the memory map.
8025 pr_info("Early memory node ranges\n");
8026 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
8027 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
8028 (u64)start_pfn << PAGE_SHIFT,
8029 ((u64)end_pfn << PAGE_SHIFT) - 1);
8030 subsection_map_init(start_pfn, end_pfn - start_pfn);
8033 /* Initialise every node */
8034 mminit_verify_pageflags_layout();
8035 setup_nr_node_ids();
8036 for_each_online_node(nid) {
8037 pg_data_t *pgdat = NODE_DATA(nid);
8038 free_area_init_node(nid);
8040 /* Any memory on that node */
8041 if (pgdat->node_present_pages)
8042 node_set_state(nid, N_MEMORY);
8043 check_for_memory(pgdat, nid);
8049 static int __init cmdline_parse_core(char *p, unsigned long *core,
8050 unsigned long *percent)
8052 unsigned long long coremem;
8058 /* Value may be a percentage of total memory, otherwise bytes */
8059 coremem = simple_strtoull(p, &endptr, 0);
8060 if (*endptr == '%') {
8061 /* Paranoid check for percent values greater than 100 */
8062 WARN_ON(coremem > 100);
8066 coremem = memparse(p, &p);
8067 /* Paranoid check that UL is enough for the coremem value */
8068 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
8070 *core = coremem >> PAGE_SHIFT;
8077 * kernelcore=size sets the amount of memory for use for allocations that
8078 * cannot be reclaimed or migrated.
8080 static int __init cmdline_parse_kernelcore(char *p)
8082 /* parse kernelcore=mirror */
8083 if (parse_option_str(p, "mirror")) {
8084 mirrored_kernelcore = true;
8088 return cmdline_parse_core(p, &required_kernelcore,
8089 &required_kernelcore_percent);
8093 * movablecore=size sets the amount of memory for use for allocations that
8094 * can be reclaimed or migrated.
8096 static int __init cmdline_parse_movablecore(char *p)
8098 return cmdline_parse_core(p, &required_movablecore,
8099 &required_movablecore_percent);
8102 early_param("kernelcore", cmdline_parse_kernelcore);
8103 early_param("movablecore", cmdline_parse_movablecore);
8105 void adjust_managed_page_count(struct page *page, long count)
8107 atomic_long_add(count, &page_zone(page)->managed_pages);
8108 totalram_pages_add(count);
8109 #ifdef CONFIG_HIGHMEM
8110 if (PageHighMem(page))
8111 totalhigh_pages_add(count);
8114 EXPORT_SYMBOL(adjust_managed_page_count);
8116 unsigned long free_reserved_area(void *start, void *end, int poison, const char *s)
8119 unsigned long pages = 0;
8121 start = (void *)PAGE_ALIGN((unsigned long)start);
8122 end = (void *)((unsigned long)end & PAGE_MASK);
8123 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
8124 struct page *page = virt_to_page(pos);
8125 void *direct_map_addr;
8128 * 'direct_map_addr' might be different from 'pos'
8129 * because some architectures' virt_to_page()
8130 * work with aliases. Getting the direct map
8131 * address ensures that we get a _writeable_
8132 * alias for the memset().
8134 direct_map_addr = page_address(page);
8136 * Perform a kasan-unchecked memset() since this memory
8137 * has not been initialized.
8139 direct_map_addr = kasan_reset_tag(direct_map_addr);
8140 if ((unsigned int)poison <= 0xFF)
8141 memset(direct_map_addr, poison, PAGE_SIZE);
8143 free_reserved_page(page);
8147 pr_info("Freeing %s memory: %ldK\n",
8148 s, pages << (PAGE_SHIFT - 10));
8153 void __init mem_init_print_info(void)
8155 unsigned long physpages, codesize, datasize, rosize, bss_size;
8156 unsigned long init_code_size, init_data_size;
8158 physpages = get_num_physpages();
8159 codesize = _etext - _stext;
8160 datasize = _edata - _sdata;
8161 rosize = __end_rodata - __start_rodata;
8162 bss_size = __bss_stop - __bss_start;
8163 init_data_size = __init_end - __init_begin;
8164 init_code_size = _einittext - _sinittext;
8167 * Detect special cases and adjust section sizes accordingly:
8168 * 1) .init.* may be embedded into .data sections
8169 * 2) .init.text.* may be out of [__init_begin, __init_end],
8170 * please refer to arch/tile/kernel/vmlinux.lds.S.
8171 * 3) .rodata.* may be embedded into .text or .data sections.
8173 #define adj_init_size(start, end, size, pos, adj) \
8175 if (start <= pos && pos < end && size > adj) \
8179 adj_init_size(__init_begin, __init_end, init_data_size,
8180 _sinittext, init_code_size);
8181 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
8182 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
8183 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
8184 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
8186 #undef adj_init_size
8188 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
8189 #ifdef CONFIG_HIGHMEM
8193 nr_free_pages() << (PAGE_SHIFT - 10),
8194 physpages << (PAGE_SHIFT - 10),
8195 codesize >> 10, datasize >> 10, rosize >> 10,
8196 (init_data_size + init_code_size) >> 10, bss_size >> 10,
8197 (physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10),
8198 totalcma_pages << (PAGE_SHIFT - 10)
8199 #ifdef CONFIG_HIGHMEM
8200 , totalhigh_pages() << (PAGE_SHIFT - 10)
8206 * set_dma_reserve - set the specified number of pages reserved in the first zone
8207 * @new_dma_reserve: The number of pages to mark reserved
8209 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
8210 * In the DMA zone, a significant percentage may be consumed by kernel image
8211 * and other unfreeable allocations which can skew the watermarks badly. This
8212 * function may optionally be used to account for unfreeable pages in the
8213 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
8214 * smaller per-cpu batchsize.
8216 void __init set_dma_reserve(unsigned long new_dma_reserve)
8218 dma_reserve = new_dma_reserve;
8221 static int page_alloc_cpu_dead(unsigned int cpu)
8225 lru_add_drain_cpu(cpu);
8229 * Spill the event counters of the dead processor
8230 * into the current processors event counters.
8231 * This artificially elevates the count of the current
8234 vm_events_fold_cpu(cpu);
8237 * Zero the differential counters of the dead processor
8238 * so that the vm statistics are consistent.
8240 * This is only okay since the processor is dead and cannot
8241 * race with what we are doing.
8243 cpu_vm_stats_fold(cpu);
8245 for_each_populated_zone(zone)
8246 zone_pcp_update(zone, 0);
8251 static int page_alloc_cpu_online(unsigned int cpu)
8255 for_each_populated_zone(zone)
8256 zone_pcp_update(zone, 1);
8261 int hashdist = HASHDIST_DEFAULT;
8263 static int __init set_hashdist(char *str)
8267 hashdist = simple_strtoul(str, &str, 0);
8270 __setup("hashdist=", set_hashdist);
8273 void __init page_alloc_init(void)
8278 if (num_node_state(N_MEMORY) == 1)
8282 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC,
8283 "mm/page_alloc:pcp",
8284 page_alloc_cpu_online,
8285 page_alloc_cpu_dead);
8290 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
8291 * or min_free_kbytes changes.
8293 static void calculate_totalreserve_pages(void)
8295 struct pglist_data *pgdat;
8296 unsigned long reserve_pages = 0;
8297 enum zone_type i, j;
8299 for_each_online_pgdat(pgdat) {
8301 pgdat->totalreserve_pages = 0;
8303 for (i = 0; i < MAX_NR_ZONES; i++) {
8304 struct zone *zone = pgdat->node_zones + i;
8306 unsigned long managed_pages = zone_managed_pages(zone);
8308 /* Find valid and maximum lowmem_reserve in the zone */
8309 for (j = i; j < MAX_NR_ZONES; j++) {
8310 if (zone->lowmem_reserve[j] > max)
8311 max = zone->lowmem_reserve[j];
8314 /* we treat the high watermark as reserved pages. */
8315 max += high_wmark_pages(zone);
8317 if (max > managed_pages)
8318 max = managed_pages;
8320 pgdat->totalreserve_pages += max;
8322 reserve_pages += max;
8325 totalreserve_pages = reserve_pages;
8329 * setup_per_zone_lowmem_reserve - called whenever
8330 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
8331 * has a correct pages reserved value, so an adequate number of
8332 * pages are left in the zone after a successful __alloc_pages().
8334 static void setup_per_zone_lowmem_reserve(void)
8336 struct pglist_data *pgdat;
8337 enum zone_type i, j;
8339 for_each_online_pgdat(pgdat) {
8340 for (i = 0; i < MAX_NR_ZONES - 1; i++) {
8341 struct zone *zone = &pgdat->node_zones[i];
8342 int ratio = sysctl_lowmem_reserve_ratio[i];
8343 bool clear = !ratio || !zone_managed_pages(zone);
8344 unsigned long managed_pages = 0;
8346 for (j = i + 1; j < MAX_NR_ZONES; j++) {
8347 struct zone *upper_zone = &pgdat->node_zones[j];
8349 managed_pages += zone_managed_pages(upper_zone);
8352 zone->lowmem_reserve[j] = 0;
8354 zone->lowmem_reserve[j] = managed_pages / ratio;
8359 /* update totalreserve_pages */
8360 calculate_totalreserve_pages();
8363 static void __setup_per_zone_wmarks(void)
8365 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
8366 unsigned long lowmem_pages = 0;
8368 unsigned long flags;
8370 /* Calculate total number of !ZONE_HIGHMEM pages */
8371 for_each_zone(zone) {
8372 if (!is_highmem(zone))
8373 lowmem_pages += zone_managed_pages(zone);
8376 for_each_zone(zone) {
8379 spin_lock_irqsave(&zone->lock, flags);
8380 tmp = (u64)pages_min * zone_managed_pages(zone);
8381 do_div(tmp, lowmem_pages);
8382 if (is_highmem(zone)) {
8384 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
8385 * need highmem pages, so cap pages_min to a small
8388 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
8389 * deltas control async page reclaim, and so should
8390 * not be capped for highmem.
8392 unsigned long min_pages;
8394 min_pages = zone_managed_pages(zone) / 1024;
8395 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
8396 zone->_watermark[WMARK_MIN] = min_pages;
8399 * If it's a lowmem zone, reserve a number of pages
8400 * proportionate to the zone's size.
8402 zone->_watermark[WMARK_MIN] = tmp;
8406 * Set the kswapd watermarks distance according to the
8407 * scale factor in proportion to available memory, but
8408 * ensure a minimum size on small systems.
8410 tmp = max_t(u64, tmp >> 2,
8411 mult_frac(zone_managed_pages(zone),
8412 watermark_scale_factor, 10000));
8414 zone->watermark_boost = 0;
8415 zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
8416 zone->_watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
8418 spin_unlock_irqrestore(&zone->lock, flags);
8421 /* update totalreserve_pages */
8422 calculate_totalreserve_pages();
8426 * setup_per_zone_wmarks - called when min_free_kbytes changes
8427 * or when memory is hot-{added|removed}
8429 * Ensures that the watermark[min,low,high] values for each zone are set
8430 * correctly with respect to min_free_kbytes.
8432 void setup_per_zone_wmarks(void)
8435 static DEFINE_SPINLOCK(lock);
8438 __setup_per_zone_wmarks();
8442 * The watermark size have changed so update the pcpu batch
8443 * and high limits or the limits may be inappropriate.
8446 zone_pcp_update(zone, 0);
8450 * Initialise min_free_kbytes.
8452 * For small machines we want it small (128k min). For large machines
8453 * we want it large (256MB max). But it is not linear, because network
8454 * bandwidth does not increase linearly with machine size. We use
8456 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
8457 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
8473 int __meminit init_per_zone_wmark_min(void)
8475 unsigned long lowmem_kbytes;
8476 int new_min_free_kbytes;
8478 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
8479 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
8481 if (new_min_free_kbytes > user_min_free_kbytes) {
8482 min_free_kbytes = new_min_free_kbytes;
8483 if (min_free_kbytes < 128)
8484 min_free_kbytes = 128;
8485 if (min_free_kbytes > 262144)
8486 min_free_kbytes = 262144;
8488 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
8489 new_min_free_kbytes, user_min_free_kbytes);
8491 setup_per_zone_wmarks();
8492 refresh_zone_stat_thresholds();
8493 setup_per_zone_lowmem_reserve();
8496 setup_min_unmapped_ratio();
8497 setup_min_slab_ratio();
8500 khugepaged_min_free_kbytes_update();
8504 postcore_initcall(init_per_zone_wmark_min)
8507 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
8508 * that we can call two helper functions whenever min_free_kbytes
8511 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
8512 void *buffer, size_t *length, loff_t *ppos)
8516 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8521 user_min_free_kbytes = min_free_kbytes;
8522 setup_per_zone_wmarks();
8527 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
8528 void *buffer, size_t *length, loff_t *ppos)
8532 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8537 setup_per_zone_wmarks();
8543 static void setup_min_unmapped_ratio(void)
8548 for_each_online_pgdat(pgdat)
8549 pgdat->min_unmapped_pages = 0;
8552 zone->zone_pgdat->min_unmapped_pages += (zone_managed_pages(zone) *
8553 sysctl_min_unmapped_ratio) / 100;
8557 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
8558 void *buffer, size_t *length, loff_t *ppos)
8562 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8566 setup_min_unmapped_ratio();
8571 static void setup_min_slab_ratio(void)
8576 for_each_online_pgdat(pgdat)
8577 pgdat->min_slab_pages = 0;
8580 zone->zone_pgdat->min_slab_pages += (zone_managed_pages(zone) *
8581 sysctl_min_slab_ratio) / 100;
8584 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
8585 void *buffer, size_t *length, loff_t *ppos)
8589 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8593 setup_min_slab_ratio();
8600 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8601 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8602 * whenever sysctl_lowmem_reserve_ratio changes.
8604 * The reserve ratio obviously has absolutely no relation with the
8605 * minimum watermarks. The lowmem reserve ratio can only make sense
8606 * if in function of the boot time zone sizes.
8608 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
8609 void *buffer, size_t *length, loff_t *ppos)
8613 proc_dointvec_minmax(table, write, buffer, length, ppos);
8615 for (i = 0; i < MAX_NR_ZONES; i++) {
8616 if (sysctl_lowmem_reserve_ratio[i] < 1)
8617 sysctl_lowmem_reserve_ratio[i] = 0;
8620 setup_per_zone_lowmem_reserve();
8625 * percpu_pagelist_high_fraction - changes the pcp->high for each zone on each
8626 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8627 * pagelist can have before it gets flushed back to buddy allocator.
8629 int percpu_pagelist_high_fraction_sysctl_handler(struct ctl_table *table,
8630 int write, void *buffer, size_t *length, loff_t *ppos)
8633 int old_percpu_pagelist_high_fraction;
8636 mutex_lock(&pcp_batch_high_lock);
8637 old_percpu_pagelist_high_fraction = percpu_pagelist_high_fraction;
8639 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
8640 if (!write || ret < 0)
8643 /* Sanity checking to avoid pcp imbalance */
8644 if (percpu_pagelist_high_fraction &&
8645 percpu_pagelist_high_fraction < MIN_PERCPU_PAGELIST_HIGH_FRACTION) {
8646 percpu_pagelist_high_fraction = old_percpu_pagelist_high_fraction;
8652 if (percpu_pagelist_high_fraction == old_percpu_pagelist_high_fraction)
8655 for_each_populated_zone(zone)
8656 zone_set_pageset_high_and_batch(zone, 0);
8658 mutex_unlock(&pcp_batch_high_lock);
8662 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8664 * Returns the number of pages that arch has reserved but
8665 * is not known to alloc_large_system_hash().
8667 static unsigned long __init arch_reserved_kernel_pages(void)
8674 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8675 * machines. As memory size is increased the scale is also increased but at
8676 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8677 * quadruples the scale is increased by one, which means the size of hash table
8678 * only doubles, instead of quadrupling as well.
8679 * Because 32-bit systems cannot have large physical memory, where this scaling
8680 * makes sense, it is disabled on such platforms.
8682 #if __BITS_PER_LONG > 32
8683 #define ADAPT_SCALE_BASE (64ul << 30)
8684 #define ADAPT_SCALE_SHIFT 2
8685 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8689 * allocate a large system hash table from bootmem
8690 * - it is assumed that the hash table must contain an exact power-of-2
8691 * quantity of entries
8692 * - limit is the number of hash buckets, not the total allocation size
8694 void *__init alloc_large_system_hash(const char *tablename,
8695 unsigned long bucketsize,
8696 unsigned long numentries,
8699 unsigned int *_hash_shift,
8700 unsigned int *_hash_mask,
8701 unsigned long low_limit,
8702 unsigned long high_limit)
8704 unsigned long long max = high_limit;
8705 unsigned long log2qty, size;
8711 /* allow the kernel cmdline to have a say */
8713 /* round applicable memory size up to nearest megabyte */
8714 numentries = nr_kernel_pages;
8715 numentries -= arch_reserved_kernel_pages();
8717 /* It isn't necessary when PAGE_SIZE >= 1MB */
8718 if (PAGE_SHIFT < 20)
8719 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
8721 #if __BITS_PER_LONG > 32
8723 unsigned long adapt;
8725 for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries;
8726 adapt <<= ADAPT_SCALE_SHIFT)
8731 /* limit to 1 bucket per 2^scale bytes of low memory */
8732 if (scale > PAGE_SHIFT)
8733 numentries >>= (scale - PAGE_SHIFT);
8735 numentries <<= (PAGE_SHIFT - scale);
8737 /* Make sure we've got at least a 0-order allocation.. */
8738 if (unlikely(flags & HASH_SMALL)) {
8739 /* Makes no sense without HASH_EARLY */
8740 WARN_ON(!(flags & HASH_EARLY));
8741 if (!(numentries >> *_hash_shift)) {
8742 numentries = 1UL << *_hash_shift;
8743 BUG_ON(!numentries);
8745 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
8746 numentries = PAGE_SIZE / bucketsize;
8748 numentries = roundup_pow_of_two(numentries);
8750 /* limit allocation size to 1/16 total memory by default */
8752 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
8753 do_div(max, bucketsize);
8755 max = min(max, 0x80000000ULL);
8757 if (numentries < low_limit)
8758 numentries = low_limit;
8759 if (numentries > max)
8762 log2qty = ilog2(numentries);
8764 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
8767 size = bucketsize << log2qty;
8768 if (flags & HASH_EARLY) {
8769 if (flags & HASH_ZERO)
8770 table = memblock_alloc(size, SMP_CACHE_BYTES);
8772 table = memblock_alloc_raw(size,
8774 } else if (get_order(size) >= MAX_ORDER || hashdist) {
8775 table = __vmalloc(size, gfp_flags);
8777 huge = is_vm_area_hugepages(table);
8780 * If bucketsize is not a power-of-two, we may free
8781 * some pages at the end of hash table which
8782 * alloc_pages_exact() automatically does
8784 table = alloc_pages_exact(size, gfp_flags);
8785 kmemleak_alloc(table, size, 1, gfp_flags);
8787 } while (!table && size > PAGE_SIZE && --log2qty);
8790 panic("Failed to allocate %s hash table\n", tablename);
8792 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8793 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
8794 virt ? (huge ? "vmalloc hugepage" : "vmalloc") : "linear");
8797 *_hash_shift = log2qty;
8799 *_hash_mask = (1 << log2qty) - 1;
8805 * This function checks whether pageblock includes unmovable pages or not.
8807 * PageLRU check without isolation or lru_lock could race so that
8808 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8809 * check without lock_page also may miss some movable non-lru pages at
8810 * race condition. So you can't expect this function should be exact.
8812 * Returns a page without holding a reference. If the caller wants to
8813 * dereference that page (e.g., dumping), it has to make sure that it
8814 * cannot get removed (e.g., via memory unplug) concurrently.
8817 struct page *has_unmovable_pages(struct zone *zone, struct page *page,
8818 int migratetype, int flags)
8820 unsigned long iter = 0;
8821 unsigned long pfn = page_to_pfn(page);
8822 unsigned long offset = pfn % pageblock_nr_pages;
8824 if (is_migrate_cma_page(page)) {
8826 * CMA allocations (alloc_contig_range) really need to mark
8827 * isolate CMA pageblocks even when they are not movable in fact
8828 * so consider them movable here.
8830 if (is_migrate_cma(migratetype))
8836 for (; iter < pageblock_nr_pages - offset; iter++) {
8837 page = pfn_to_page(pfn + iter);
8840 * Both, bootmem allocations and memory holes are marked
8841 * PG_reserved and are unmovable. We can even have unmovable
8842 * allocations inside ZONE_MOVABLE, for example when
8843 * specifying "movablecore".
8845 if (PageReserved(page))
8849 * If the zone is movable and we have ruled out all reserved
8850 * pages then it should be reasonably safe to assume the rest
8853 if (zone_idx(zone) == ZONE_MOVABLE)
8857 * Hugepages are not in LRU lists, but they're movable.
8858 * THPs are on the LRU, but need to be counted as #small pages.
8859 * We need not scan over tail pages because we don't
8860 * handle each tail page individually in migration.
8862 if (PageHuge(page) || PageTransCompound(page)) {
8863 struct page *head = compound_head(page);
8864 unsigned int skip_pages;
8866 if (PageHuge(page)) {
8867 if (!hugepage_migration_supported(page_hstate(head)))
8869 } else if (!PageLRU(head) && !__PageMovable(head)) {
8873 skip_pages = compound_nr(head) - (page - head);
8874 iter += skip_pages - 1;
8879 * We can't use page_count without pin a page
8880 * because another CPU can free compound page.
8881 * This check already skips compound tails of THP
8882 * because their page->_refcount is zero at all time.
8884 if (!page_ref_count(page)) {
8885 if (PageBuddy(page))
8886 iter += (1 << buddy_order(page)) - 1;
8891 * The HWPoisoned page may be not in buddy system, and
8892 * page_count() is not 0.
8894 if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
8898 * We treat all PageOffline() pages as movable when offlining
8899 * to give drivers a chance to decrement their reference count
8900 * in MEM_GOING_OFFLINE in order to indicate that these pages
8901 * can be offlined as there are no direct references anymore.
8902 * For actually unmovable PageOffline() where the driver does
8903 * not support this, we will fail later when trying to actually
8904 * move these pages that still have a reference count > 0.
8905 * (false negatives in this function only)
8907 if ((flags & MEMORY_OFFLINE) && PageOffline(page))
8910 if (__PageMovable(page) || PageLRU(page))
8914 * If there are RECLAIMABLE pages, we need to check
8915 * it. But now, memory offline itself doesn't call
8916 * shrink_node_slabs() and it still to be fixed.
8923 #ifdef CONFIG_CONTIG_ALLOC
8924 static unsigned long pfn_max_align_down(unsigned long pfn)
8926 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
8927 pageblock_nr_pages) - 1);
8930 static unsigned long pfn_max_align_up(unsigned long pfn)
8932 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
8933 pageblock_nr_pages));
8936 #if defined(CONFIG_DYNAMIC_DEBUG) || \
8937 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
8938 /* Usage: See admin-guide/dynamic-debug-howto.rst */
8939 static void alloc_contig_dump_pages(struct list_head *page_list)
8941 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, "migrate failure");
8943 if (DYNAMIC_DEBUG_BRANCH(descriptor)) {
8947 list_for_each_entry(page, page_list, lru)
8948 dump_page(page, "migration failure");
8952 static inline void alloc_contig_dump_pages(struct list_head *page_list)
8957 /* [start, end) must belong to a single zone. */
8958 static int __alloc_contig_migrate_range(struct compact_control *cc,
8959 unsigned long start, unsigned long end)
8961 /* This function is based on compact_zone() from compaction.c. */
8962 unsigned int nr_reclaimed;
8963 unsigned long pfn = start;
8964 unsigned int tries = 0;
8966 struct migration_target_control mtc = {
8967 .nid = zone_to_nid(cc->zone),
8968 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
8971 lru_cache_disable();
8973 while (pfn < end || !list_empty(&cc->migratepages)) {
8974 if (fatal_signal_pending(current)) {
8979 if (list_empty(&cc->migratepages)) {
8980 cc->nr_migratepages = 0;
8981 ret = isolate_migratepages_range(cc, pfn, end);
8982 if (ret && ret != -EAGAIN)
8984 pfn = cc->migrate_pfn;
8986 } else if (++tries == 5) {
8991 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
8993 cc->nr_migratepages -= nr_reclaimed;
8995 ret = migrate_pages(&cc->migratepages, alloc_migration_target,
8996 NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE, NULL);
8999 * On -ENOMEM, migrate_pages() bails out right away. It is pointless
9000 * to retry again over this error, so do the same here.
9009 alloc_contig_dump_pages(&cc->migratepages);
9010 putback_movable_pages(&cc->migratepages);
9017 * alloc_contig_range() -- tries to allocate given range of pages
9018 * @start: start PFN to allocate
9019 * @end: one-past-the-last PFN to allocate
9020 * @migratetype: migratetype of the underlying pageblocks (either
9021 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
9022 * in range must have the same migratetype and it must
9023 * be either of the two.
9024 * @gfp_mask: GFP mask to use during compaction
9026 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
9027 * aligned. The PFN range must belong to a single zone.
9029 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
9030 * pageblocks in the range. Once isolated, the pageblocks should not
9031 * be modified by others.
9033 * Return: zero on success or negative error code. On success all
9034 * pages which PFN is in [start, end) are allocated for the caller and
9035 * need to be freed with free_contig_range().
9037 int alloc_contig_range(unsigned long start, unsigned long end,
9038 unsigned migratetype, gfp_t gfp_mask)
9040 unsigned long outer_start, outer_end;
9044 struct compact_control cc = {
9045 .nr_migratepages = 0,
9047 .zone = page_zone(pfn_to_page(start)),
9048 .mode = MIGRATE_SYNC,
9049 .ignore_skip_hint = true,
9050 .no_set_skip_hint = true,
9051 .gfp_mask = current_gfp_context(gfp_mask),
9052 .alloc_contig = true,
9054 INIT_LIST_HEAD(&cc.migratepages);
9057 * What we do here is we mark all pageblocks in range as
9058 * MIGRATE_ISOLATE. Because pageblock and max order pages may
9059 * have different sizes, and due to the way page allocator
9060 * work, we align the range to biggest of the two pages so
9061 * that page allocator won't try to merge buddies from
9062 * different pageblocks and change MIGRATE_ISOLATE to some
9063 * other migration type.
9065 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
9066 * migrate the pages from an unaligned range (ie. pages that
9067 * we are interested in). This will put all the pages in
9068 * range back to page allocator as MIGRATE_ISOLATE.
9070 * When this is done, we take the pages in range from page
9071 * allocator removing them from the buddy system. This way
9072 * page allocator will never consider using them.
9074 * This lets us mark the pageblocks back as
9075 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
9076 * aligned range but not in the unaligned, original range are
9077 * put back to page allocator so that buddy can use them.
9080 ret = start_isolate_page_range(pfn_max_align_down(start),
9081 pfn_max_align_up(end), migratetype, 0);
9085 drain_all_pages(cc.zone);
9088 * In case of -EBUSY, we'd like to know which page causes problem.
9089 * So, just fall through. test_pages_isolated() has a tracepoint
9090 * which will report the busy page.
9092 * It is possible that busy pages could become available before
9093 * the call to test_pages_isolated, and the range will actually be
9094 * allocated. So, if we fall through be sure to clear ret so that
9095 * -EBUSY is not accidentally used or returned to caller.
9097 ret = __alloc_contig_migrate_range(&cc, start, end);
9098 if (ret && ret != -EBUSY)
9103 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
9104 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
9105 * more, all pages in [start, end) are free in page allocator.
9106 * What we are going to do is to allocate all pages from
9107 * [start, end) (that is remove them from page allocator).
9109 * The only problem is that pages at the beginning and at the
9110 * end of interesting range may be not aligned with pages that
9111 * page allocator holds, ie. they can be part of higher order
9112 * pages. Because of this, we reserve the bigger range and
9113 * once this is done free the pages we are not interested in.
9115 * We don't have to hold zone->lock here because the pages are
9116 * isolated thus they won't get removed from buddy.
9120 outer_start = start;
9121 while (!PageBuddy(pfn_to_page(outer_start))) {
9122 if (++order >= MAX_ORDER) {
9123 outer_start = start;
9126 outer_start &= ~0UL << order;
9129 if (outer_start != start) {
9130 order = buddy_order(pfn_to_page(outer_start));
9133 * outer_start page could be small order buddy page and
9134 * it doesn't include start page. Adjust outer_start
9135 * in this case to report failed page properly
9136 * on tracepoint in test_pages_isolated()
9138 if (outer_start + (1UL << order) <= start)
9139 outer_start = start;
9142 /* Make sure the range is really isolated. */
9143 if (test_pages_isolated(outer_start, end, 0)) {
9148 /* Grab isolated pages from freelists. */
9149 outer_end = isolate_freepages_range(&cc, outer_start, end);
9155 /* Free head and tail (if any) */
9156 if (start != outer_start)
9157 free_contig_range(outer_start, start - outer_start);
9158 if (end != outer_end)
9159 free_contig_range(end, outer_end - end);
9162 undo_isolate_page_range(pfn_max_align_down(start),
9163 pfn_max_align_up(end), migratetype);
9166 EXPORT_SYMBOL(alloc_contig_range);
9168 static int __alloc_contig_pages(unsigned long start_pfn,
9169 unsigned long nr_pages, gfp_t gfp_mask)
9171 unsigned long end_pfn = start_pfn + nr_pages;
9173 return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
9177 static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
9178 unsigned long nr_pages)
9180 unsigned long i, end_pfn = start_pfn + nr_pages;
9183 for (i = start_pfn; i < end_pfn; i++) {
9184 page = pfn_to_online_page(i);
9188 if (page_zone(page) != z)
9191 if (PageReserved(page))
9197 static bool zone_spans_last_pfn(const struct zone *zone,
9198 unsigned long start_pfn, unsigned long nr_pages)
9200 unsigned long last_pfn = start_pfn + nr_pages - 1;
9202 return zone_spans_pfn(zone, last_pfn);
9206 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
9207 * @nr_pages: Number of contiguous pages to allocate
9208 * @gfp_mask: GFP mask to limit search and used during compaction
9210 * @nodemask: Mask for other possible nodes
9212 * This routine is a wrapper around alloc_contig_range(). It scans over zones
9213 * on an applicable zonelist to find a contiguous pfn range which can then be
9214 * tried for allocation with alloc_contig_range(). This routine is intended
9215 * for allocation requests which can not be fulfilled with the buddy allocator.
9217 * The allocated memory is always aligned to a page boundary. If nr_pages is a
9218 * power of two then the alignment is guaranteed to be to the given nr_pages
9219 * (e.g. 1GB request would be aligned to 1GB).
9221 * Allocated pages can be freed with free_contig_range() or by manually calling
9222 * __free_page() on each allocated page.
9224 * Return: pointer to contiguous pages on success, or NULL if not successful.
9226 struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
9227 int nid, nodemask_t *nodemask)
9229 unsigned long ret, pfn, flags;
9230 struct zonelist *zonelist;
9234 zonelist = node_zonelist(nid, gfp_mask);
9235 for_each_zone_zonelist_nodemask(zone, z, zonelist,
9236 gfp_zone(gfp_mask), nodemask) {
9237 spin_lock_irqsave(&zone->lock, flags);
9239 pfn = ALIGN(zone->zone_start_pfn, nr_pages);
9240 while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
9241 if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
9243 * We release the zone lock here because
9244 * alloc_contig_range() will also lock the zone
9245 * at some point. If there's an allocation
9246 * spinning on this lock, it may win the race
9247 * and cause alloc_contig_range() to fail...
9249 spin_unlock_irqrestore(&zone->lock, flags);
9250 ret = __alloc_contig_pages(pfn, nr_pages,
9253 return pfn_to_page(pfn);
9254 spin_lock_irqsave(&zone->lock, flags);
9258 spin_unlock_irqrestore(&zone->lock, flags);
9262 #endif /* CONFIG_CONTIG_ALLOC */
9264 void free_contig_range(unsigned long pfn, unsigned long nr_pages)
9266 unsigned long count = 0;
9268 for (; nr_pages--; pfn++) {
9269 struct page *page = pfn_to_page(pfn);
9271 count += page_count(page) != 1;
9274 WARN(count != 0, "%lu pages are still in use!\n", count);
9276 EXPORT_SYMBOL(free_contig_range);
9279 * The zone indicated has a new number of managed_pages; batch sizes and percpu
9280 * page high values need to be recalculated.
9282 void zone_pcp_update(struct zone *zone, int cpu_online)
9284 mutex_lock(&pcp_batch_high_lock);
9285 zone_set_pageset_high_and_batch(zone, cpu_online);
9286 mutex_unlock(&pcp_batch_high_lock);
9290 * Effectively disable pcplists for the zone by setting the high limit to 0
9291 * and draining all cpus. A concurrent page freeing on another CPU that's about
9292 * to put the page on pcplist will either finish before the drain and the page
9293 * will be drained, or observe the new high limit and skip the pcplist.
9295 * Must be paired with a call to zone_pcp_enable().
9297 void zone_pcp_disable(struct zone *zone)
9299 mutex_lock(&pcp_batch_high_lock);
9300 __zone_set_pageset_high_and_batch(zone, 0, 1);
9301 __drain_all_pages(zone, true);
9304 void zone_pcp_enable(struct zone *zone)
9306 __zone_set_pageset_high_and_batch(zone, zone->pageset_high, zone->pageset_batch);
9307 mutex_unlock(&pcp_batch_high_lock);
9310 void zone_pcp_reset(struct zone *zone)
9313 struct per_cpu_zonestat *pzstats;
9315 if (zone->per_cpu_pageset != &boot_pageset) {
9316 for_each_online_cpu(cpu) {
9317 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
9318 drain_zonestat(zone, pzstats);
9320 free_percpu(zone->per_cpu_pageset);
9321 free_percpu(zone->per_cpu_zonestats);
9322 zone->per_cpu_pageset = &boot_pageset;
9323 zone->per_cpu_zonestats = &boot_zonestats;
9327 #ifdef CONFIG_MEMORY_HOTREMOVE
9329 * All pages in the range must be in a single zone, must not contain holes,
9330 * must span full sections, and must be isolated before calling this function.
9332 void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
9334 unsigned long pfn = start_pfn;
9338 unsigned long flags;
9340 offline_mem_sections(pfn, end_pfn);
9341 zone = page_zone(pfn_to_page(pfn));
9342 spin_lock_irqsave(&zone->lock, flags);
9343 while (pfn < end_pfn) {
9344 page = pfn_to_page(pfn);
9346 * The HWPoisoned page may be not in buddy system, and
9347 * page_count() is not 0.
9349 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
9354 * At this point all remaining PageOffline() pages have a
9355 * reference count of 0 and can simply be skipped.
9357 if (PageOffline(page)) {
9358 BUG_ON(page_count(page));
9359 BUG_ON(PageBuddy(page));
9364 BUG_ON(page_count(page));
9365 BUG_ON(!PageBuddy(page));
9366 order = buddy_order(page);
9367 del_page_from_free_list(page, zone, order);
9368 pfn += (1 << order);
9370 spin_unlock_irqrestore(&zone->lock, flags);
9374 bool is_free_buddy_page(struct page *page)
9376 struct zone *zone = page_zone(page);
9377 unsigned long pfn = page_to_pfn(page);
9378 unsigned long flags;
9381 spin_lock_irqsave(&zone->lock, flags);
9382 for (order = 0; order < MAX_ORDER; order++) {
9383 struct page *page_head = page - (pfn & ((1 << order) - 1));
9385 if (PageBuddy(page_head) && buddy_order(page_head) >= order)
9388 spin_unlock_irqrestore(&zone->lock, flags);
9390 return order < MAX_ORDER;
9393 #ifdef CONFIG_MEMORY_FAILURE
9395 * Break down a higher-order page in sub-pages, and keep our target out of
9398 static void break_down_buddy_pages(struct zone *zone, struct page *page,
9399 struct page *target, int low, int high,
9402 unsigned long size = 1 << high;
9403 struct page *current_buddy, *next_page;
9405 while (high > low) {
9409 if (target >= &page[size]) {
9410 next_page = page + size;
9411 current_buddy = page;
9414 current_buddy = page + size;
9417 if (set_page_guard(zone, current_buddy, high, migratetype))
9420 if (current_buddy != target) {
9421 add_to_free_list(current_buddy, zone, high, migratetype);
9422 set_buddy_order(current_buddy, high);
9429 * Take a page that will be marked as poisoned off the buddy allocator.
9431 bool take_page_off_buddy(struct page *page)
9433 struct zone *zone = page_zone(page);
9434 unsigned long pfn = page_to_pfn(page);
9435 unsigned long flags;
9439 spin_lock_irqsave(&zone->lock, flags);
9440 for (order = 0; order < MAX_ORDER; order++) {
9441 struct page *page_head = page - (pfn & ((1 << order) - 1));
9442 int page_order = buddy_order(page_head);
9444 if (PageBuddy(page_head) && page_order >= order) {
9445 unsigned long pfn_head = page_to_pfn(page_head);
9446 int migratetype = get_pfnblock_migratetype(page_head,
9449 del_page_from_free_list(page_head, zone, page_order);
9450 break_down_buddy_pages(zone, page_head, page, 0,
9451 page_order, migratetype);
9452 if (!is_migrate_isolate(migratetype))
9453 __mod_zone_freepage_state(zone, -1, migratetype);
9457 if (page_count(page_head) > 0)
9460 spin_unlock_irqrestore(&zone->lock, flags);