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>
76 #include <asm/sections.h>
77 #include <asm/tlbflush.h>
78 #include <asm/div64.h>
81 #include "page_reporting.h"
83 /* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
84 typedef int __bitwise fpi_t;
86 /* No special request */
87 #define FPI_NONE ((__force fpi_t)0)
90 * Skip free page reporting notification for the (possibly merged) page.
91 * This does not hinder free page reporting from grabbing the page,
92 * reporting it and marking it "reported" - it only skips notifying
93 * the free page reporting infrastructure about a newly freed page. For
94 * example, used when temporarily pulling a page from a freelist and
95 * putting it back unmodified.
97 #define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0))
100 * Place the (possibly merged) page to the tail of the freelist. Will ignore
101 * page shuffling (relevant code - e.g., memory onlining - is expected to
102 * shuffle the whole zone).
104 * Note: No code should rely on this flag for correctness - it's purely
105 * to allow for optimizations when handing back either fresh pages
106 * (memory onlining) or untouched pages (page isolation, free page
109 #define FPI_TO_TAIL ((__force fpi_t)BIT(1))
111 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
112 static DEFINE_MUTEX(pcp_batch_high_lock);
113 #define MIN_PERCPU_PAGELIST_FRACTION (8)
115 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
116 DEFINE_PER_CPU(int, numa_node);
117 EXPORT_PER_CPU_SYMBOL(numa_node);
120 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
122 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
124 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
125 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
126 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
127 * defined in <linux/topology.h>.
129 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
130 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
133 /* work_structs for global per-cpu drains */
136 struct work_struct work;
138 static DEFINE_MUTEX(pcpu_drain_mutex);
139 static DEFINE_PER_CPU(struct pcpu_drain, pcpu_drain);
141 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
142 volatile unsigned long latent_entropy __latent_entropy;
143 EXPORT_SYMBOL(latent_entropy);
147 * Array of node states.
149 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
150 [N_POSSIBLE] = NODE_MASK_ALL,
151 [N_ONLINE] = { { [0] = 1UL } },
153 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
154 #ifdef CONFIG_HIGHMEM
155 [N_HIGH_MEMORY] = { { [0] = 1UL } },
157 [N_MEMORY] = { { [0] = 1UL } },
158 [N_CPU] = { { [0] = 1UL } },
161 EXPORT_SYMBOL(node_states);
163 atomic_long_t _totalram_pages __read_mostly;
164 EXPORT_SYMBOL(_totalram_pages);
165 unsigned long totalreserve_pages __read_mostly;
166 unsigned long totalcma_pages __read_mostly;
168 int percpu_pagelist_fraction;
169 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
170 DEFINE_STATIC_KEY_FALSE(init_on_alloc);
171 EXPORT_SYMBOL(init_on_alloc);
173 DEFINE_STATIC_KEY_FALSE(init_on_free);
174 EXPORT_SYMBOL(init_on_free);
176 static bool _init_on_alloc_enabled_early __read_mostly
177 = IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON);
178 static int __init early_init_on_alloc(char *buf)
181 return kstrtobool(buf, &_init_on_alloc_enabled_early);
183 early_param("init_on_alloc", early_init_on_alloc);
185 static bool _init_on_free_enabled_early __read_mostly
186 = IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON);
187 static int __init early_init_on_free(char *buf)
189 return kstrtobool(buf, &_init_on_free_enabled_early);
191 early_param("init_on_free", early_init_on_free);
194 * A cached value of the page's pageblock's migratetype, used when the page is
195 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
196 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
197 * Also the migratetype set in the page does not necessarily match the pcplist
198 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
199 * other index - this ensures that it will be put on the correct CMA freelist.
201 static inline int get_pcppage_migratetype(struct page *page)
206 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
208 page->index = migratetype;
211 #ifdef CONFIG_PM_SLEEP
213 * The following functions are used by the suspend/hibernate code to temporarily
214 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
215 * while devices are suspended. To avoid races with the suspend/hibernate code,
216 * they should always be called with system_transition_mutex held
217 * (gfp_allowed_mask also should only be modified with system_transition_mutex
218 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
219 * with that modification).
222 static gfp_t saved_gfp_mask;
224 void pm_restore_gfp_mask(void)
226 WARN_ON(!mutex_is_locked(&system_transition_mutex));
227 if (saved_gfp_mask) {
228 gfp_allowed_mask = saved_gfp_mask;
233 void pm_restrict_gfp_mask(void)
235 WARN_ON(!mutex_is_locked(&system_transition_mutex));
236 WARN_ON(saved_gfp_mask);
237 saved_gfp_mask = gfp_allowed_mask;
238 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
241 bool pm_suspended_storage(void)
243 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
247 #endif /* CONFIG_PM_SLEEP */
249 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
250 unsigned int pageblock_order __read_mostly;
253 static void __free_pages_ok(struct page *page, unsigned int order,
257 * results with 256, 32 in the lowmem_reserve sysctl:
258 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
259 * 1G machine -> (16M dma, 784M normal, 224M high)
260 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
261 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
262 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
264 * TBD: should special case ZONE_DMA32 machines here - in those we normally
265 * don't need any ZONE_NORMAL reservation
267 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
268 #ifdef CONFIG_ZONE_DMA
271 #ifdef CONFIG_ZONE_DMA32
275 #ifdef CONFIG_HIGHMEM
281 static char * const zone_names[MAX_NR_ZONES] = {
282 #ifdef CONFIG_ZONE_DMA
285 #ifdef CONFIG_ZONE_DMA32
289 #ifdef CONFIG_HIGHMEM
293 #ifdef CONFIG_ZONE_DEVICE
298 const char * const migratetype_names[MIGRATE_TYPES] = {
306 #ifdef CONFIG_MEMORY_ISOLATION
311 compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {
312 [NULL_COMPOUND_DTOR] = NULL,
313 [COMPOUND_PAGE_DTOR] = free_compound_page,
314 #ifdef CONFIG_HUGETLB_PAGE
315 [HUGETLB_PAGE_DTOR] = free_huge_page,
317 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
318 [TRANSHUGE_PAGE_DTOR] = free_transhuge_page,
322 int min_free_kbytes = 1024;
323 int user_min_free_kbytes = -1;
324 #ifdef CONFIG_DISCONTIGMEM
326 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
327 * are not on separate NUMA nodes. Functionally this works but with
328 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
329 * quite small. By default, do not boost watermarks on discontigmem as in
330 * many cases very high-order allocations like THP are likely to be
331 * unsupported and the premature reclaim offsets the advantage of long-term
332 * fragmentation avoidance.
334 int watermark_boost_factor __read_mostly;
336 int watermark_boost_factor __read_mostly = 15000;
338 int watermark_scale_factor = 10;
340 static unsigned long nr_kernel_pages __initdata;
341 static unsigned long nr_all_pages __initdata;
342 static unsigned long dma_reserve __initdata;
344 static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata;
345 static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata;
346 static unsigned long required_kernelcore __initdata;
347 static unsigned long required_kernelcore_percent __initdata;
348 static unsigned long required_movablecore __initdata;
349 static unsigned long required_movablecore_percent __initdata;
350 static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
351 static bool mirrored_kernelcore __meminitdata;
353 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
355 EXPORT_SYMBOL(movable_zone);
358 unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
359 unsigned int nr_online_nodes __read_mostly = 1;
360 EXPORT_SYMBOL(nr_node_ids);
361 EXPORT_SYMBOL(nr_online_nodes);
364 int page_group_by_mobility_disabled __read_mostly;
366 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
368 * During boot we initialize deferred pages on-demand, as needed, but once
369 * page_alloc_init_late() has finished, the deferred pages are all initialized,
370 * and we can permanently disable that path.
372 static DEFINE_STATIC_KEY_TRUE(deferred_pages);
375 * Calling kasan_free_pages() only after deferred memory initialization
376 * has completed. Poisoning pages during deferred memory init will greatly
377 * lengthen the process and cause problem in large memory systems as the
378 * deferred pages initialization is done with interrupt disabled.
380 * Assuming that there will be no reference to those newly initialized
381 * pages before they are ever allocated, this should have no effect on
382 * KASAN memory tracking as the poison will be properly inserted at page
383 * allocation time. The only corner case is when pages are allocated by
384 * on-demand allocation and then freed again before the deferred pages
385 * initialization is done, but this is not likely to happen.
387 static inline void kasan_free_nondeferred_pages(struct page *page, int order)
389 if (!static_branch_unlikely(&deferred_pages))
390 kasan_free_pages(page, order);
393 /* Returns true if the struct page for the pfn is uninitialised */
394 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
396 int nid = early_pfn_to_nid(pfn);
398 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
405 * Returns true when the remaining initialisation should be deferred until
406 * later in the boot cycle when it can be parallelised.
408 static bool __meminit
409 defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
411 static unsigned long prev_end_pfn, nr_initialised;
414 * prev_end_pfn static that contains the end of previous zone
415 * No need to protect because called very early in boot before smp_init.
417 if (prev_end_pfn != end_pfn) {
418 prev_end_pfn = end_pfn;
422 /* Always populate low zones for address-constrained allocations */
423 if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
426 if (NODE_DATA(nid)->first_deferred_pfn != ULONG_MAX)
429 * We start only with one section of pages, more pages are added as
430 * needed until the rest of deferred pages are initialized.
433 if ((nr_initialised > PAGES_PER_SECTION) &&
434 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
435 NODE_DATA(nid)->first_deferred_pfn = pfn;
441 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
443 static inline bool early_page_uninitialised(unsigned long pfn)
448 static inline bool defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
454 /* Return a pointer to the bitmap storing bits affecting a block of pages */
455 static inline unsigned long *get_pageblock_bitmap(struct page *page,
458 #ifdef CONFIG_SPARSEMEM
459 return section_to_usemap(__pfn_to_section(pfn));
461 return page_zone(page)->pageblock_flags;
462 #endif /* CONFIG_SPARSEMEM */
465 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
467 #ifdef CONFIG_SPARSEMEM
468 pfn &= (PAGES_PER_SECTION-1);
470 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
471 #endif /* CONFIG_SPARSEMEM */
472 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
475 static __always_inline
476 unsigned long __get_pfnblock_flags_mask(struct page *page,
480 unsigned long *bitmap;
481 unsigned long bitidx, word_bitidx;
484 bitmap = get_pageblock_bitmap(page, pfn);
485 bitidx = pfn_to_bitidx(page, pfn);
486 word_bitidx = bitidx / BITS_PER_LONG;
487 bitidx &= (BITS_PER_LONG-1);
489 word = bitmap[word_bitidx];
490 return (word >> bitidx) & mask;
494 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
495 * @page: The page within the block of interest
496 * @pfn: The target page frame number
497 * @mask: mask of bits that the caller is interested in
499 * Return: pageblock_bits flags
501 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
504 return __get_pfnblock_flags_mask(page, pfn, mask);
507 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
509 return __get_pfnblock_flags_mask(page, pfn, MIGRATETYPE_MASK);
513 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
514 * @page: The page within the block of interest
515 * @flags: The flags to set
516 * @pfn: The target page frame number
517 * @mask: mask of bits that the caller is interested in
519 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
523 unsigned long *bitmap;
524 unsigned long bitidx, word_bitidx;
525 unsigned long old_word, word;
527 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
528 BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
530 bitmap = get_pageblock_bitmap(page, pfn);
531 bitidx = pfn_to_bitidx(page, pfn);
532 word_bitidx = bitidx / BITS_PER_LONG;
533 bitidx &= (BITS_PER_LONG-1);
535 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
540 word = READ_ONCE(bitmap[word_bitidx]);
542 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
543 if (word == old_word)
549 void set_pageblock_migratetype(struct page *page, int migratetype)
551 if (unlikely(page_group_by_mobility_disabled &&
552 migratetype < MIGRATE_PCPTYPES))
553 migratetype = MIGRATE_UNMOVABLE;
555 set_pfnblock_flags_mask(page, (unsigned long)migratetype,
556 page_to_pfn(page), MIGRATETYPE_MASK);
559 #ifdef CONFIG_DEBUG_VM
560 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
564 unsigned long pfn = page_to_pfn(page);
565 unsigned long sp, start_pfn;
568 seq = zone_span_seqbegin(zone);
569 start_pfn = zone->zone_start_pfn;
570 sp = zone->spanned_pages;
571 if (!zone_spans_pfn(zone, pfn))
573 } while (zone_span_seqretry(zone, seq));
576 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
577 pfn, zone_to_nid(zone), zone->name,
578 start_pfn, start_pfn + sp);
583 static int page_is_consistent(struct zone *zone, struct page *page)
585 if (!pfn_valid_within(page_to_pfn(page)))
587 if (zone != page_zone(page))
593 * Temporary debugging check for pages not lying within a given zone.
595 static int __maybe_unused bad_range(struct zone *zone, struct page *page)
597 if (page_outside_zone_boundaries(zone, page))
599 if (!page_is_consistent(zone, page))
605 static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
611 static void bad_page(struct page *page, const char *reason)
613 static unsigned long resume;
614 static unsigned long nr_shown;
615 static unsigned long nr_unshown;
618 * Allow a burst of 60 reports, then keep quiet for that minute;
619 * or allow a steady drip of one report per second.
621 if (nr_shown == 60) {
622 if (time_before(jiffies, resume)) {
628 "BUG: Bad page state: %lu messages suppressed\n",
635 resume = jiffies + 60 * HZ;
637 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
638 current->comm, page_to_pfn(page));
639 __dump_page(page, reason);
640 dump_page_owner(page);
645 /* Leave bad fields for debug, except PageBuddy could make trouble */
646 page_mapcount_reset(page); /* remove PageBuddy */
647 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
651 * Higher-order pages are called "compound pages". They are structured thusly:
653 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
655 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
656 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
658 * The first tail page's ->compound_dtor holds the offset in array of compound
659 * page destructors. See compound_page_dtors.
661 * The first tail page's ->compound_order holds the order of allocation.
662 * This usage means that zero-order pages may not be compound.
665 void free_compound_page(struct page *page)
667 mem_cgroup_uncharge(page);
668 __free_pages_ok(page, compound_order(page), FPI_NONE);
671 void prep_compound_page(struct page *page, unsigned int order)
674 int nr_pages = 1 << order;
677 for (i = 1; i < nr_pages; i++) {
678 struct page *p = page + i;
679 set_page_count(p, 0);
680 p->mapping = TAIL_MAPPING;
681 set_compound_head(p, page);
684 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
685 set_compound_order(page, order);
686 atomic_set(compound_mapcount_ptr(page), -1);
687 if (hpage_pincount_available(page))
688 atomic_set(compound_pincount_ptr(page), 0);
691 #ifdef CONFIG_DEBUG_PAGEALLOC
692 unsigned int _debug_guardpage_minorder;
694 bool _debug_pagealloc_enabled_early __read_mostly
695 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
696 EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
697 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
698 EXPORT_SYMBOL(_debug_pagealloc_enabled);
700 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
702 static int __init early_debug_pagealloc(char *buf)
704 return kstrtobool(buf, &_debug_pagealloc_enabled_early);
706 early_param("debug_pagealloc", early_debug_pagealloc);
708 static int __init debug_guardpage_minorder_setup(char *buf)
712 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
713 pr_err("Bad debug_guardpage_minorder value\n");
716 _debug_guardpage_minorder = res;
717 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
720 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
722 static inline bool set_page_guard(struct zone *zone, struct page *page,
723 unsigned int order, int migratetype)
725 if (!debug_guardpage_enabled())
728 if (order >= debug_guardpage_minorder())
731 __SetPageGuard(page);
732 INIT_LIST_HEAD(&page->lru);
733 set_page_private(page, order);
734 /* Guard pages are not available for any usage */
735 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
740 static inline void clear_page_guard(struct zone *zone, struct page *page,
741 unsigned int order, int migratetype)
743 if (!debug_guardpage_enabled())
746 __ClearPageGuard(page);
748 set_page_private(page, 0);
749 if (!is_migrate_isolate(migratetype))
750 __mod_zone_freepage_state(zone, (1 << order), migratetype);
753 static inline bool set_page_guard(struct zone *zone, struct page *page,
754 unsigned int order, int migratetype) { return false; }
755 static inline void clear_page_guard(struct zone *zone, struct page *page,
756 unsigned int order, int migratetype) {}
760 * Enable static keys related to various memory debugging and hardening options.
761 * Some override others, and depend on early params that are evaluated in the
762 * order of appearance. So we need to first gather the full picture of what was
763 * enabled, and then make decisions.
765 void init_mem_debugging_and_hardening(void)
767 if (_init_on_alloc_enabled_early) {
768 if (page_poisoning_enabled())
769 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
770 "will take precedence over init_on_alloc\n");
772 static_branch_enable(&init_on_alloc);
774 if (_init_on_free_enabled_early) {
775 if (page_poisoning_enabled())
776 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
777 "will take precedence over init_on_free\n");
779 static_branch_enable(&init_on_free);
782 #ifdef CONFIG_PAGE_POISONING
784 * Page poisoning is debug page alloc for some arches. If
785 * either of those options are enabled, enable poisoning.
787 if (page_poisoning_enabled() ||
788 (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
789 debug_pagealloc_enabled()))
790 static_branch_enable(&_page_poisoning_enabled);
793 #ifdef CONFIG_DEBUG_PAGEALLOC
794 if (!debug_pagealloc_enabled())
797 static_branch_enable(&_debug_pagealloc_enabled);
799 if (!debug_guardpage_minorder())
802 static_branch_enable(&_debug_guardpage_enabled);
806 static inline void set_buddy_order(struct page *page, unsigned int order)
808 set_page_private(page, order);
809 __SetPageBuddy(page);
813 * This function checks whether a page is free && is the buddy
814 * we can coalesce a page and its buddy if
815 * (a) the buddy is not in a hole (check before calling!) &&
816 * (b) the buddy is in the buddy system &&
817 * (c) a page and its buddy have the same order &&
818 * (d) a page and its buddy are in the same zone.
820 * For recording whether a page is in the buddy system, we set PageBuddy.
821 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
823 * For recording page's order, we use page_private(page).
825 static inline bool page_is_buddy(struct page *page, struct page *buddy,
828 if (!page_is_guard(buddy) && !PageBuddy(buddy))
831 if (buddy_order(buddy) != order)
835 * zone check is done late to avoid uselessly calculating
836 * zone/node ids for pages that could never merge.
838 if (page_zone_id(page) != page_zone_id(buddy))
841 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
846 #ifdef CONFIG_COMPACTION
847 static inline struct capture_control *task_capc(struct zone *zone)
849 struct capture_control *capc = current->capture_control;
851 return unlikely(capc) &&
852 !(current->flags & PF_KTHREAD) &&
854 capc->cc->zone == zone ? capc : NULL;
858 compaction_capture(struct capture_control *capc, struct page *page,
859 int order, int migratetype)
861 if (!capc || order != capc->cc->order)
864 /* Do not accidentally pollute CMA or isolated regions*/
865 if (is_migrate_cma(migratetype) ||
866 is_migrate_isolate(migratetype))
870 * Do not let lower order allocations polluate a movable pageblock.
871 * This might let an unmovable request use a reclaimable pageblock
872 * and vice-versa but no more than normal fallback logic which can
873 * have trouble finding a high-order free page.
875 if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
883 static inline struct capture_control *task_capc(struct zone *zone)
889 compaction_capture(struct capture_control *capc, struct page *page,
890 int order, int migratetype)
894 #endif /* CONFIG_COMPACTION */
896 /* Used for pages not on another list */
897 static inline void add_to_free_list(struct page *page, struct zone *zone,
898 unsigned int order, int migratetype)
900 struct free_area *area = &zone->free_area[order];
902 list_add(&page->lru, &area->free_list[migratetype]);
906 /* Used for pages not on another list */
907 static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
908 unsigned int order, int migratetype)
910 struct free_area *area = &zone->free_area[order];
912 list_add_tail(&page->lru, &area->free_list[migratetype]);
917 * Used for pages which are on another list. Move the pages to the tail
918 * of the list - so the moved pages won't immediately be considered for
919 * allocation again (e.g., optimization for memory onlining).
921 static inline void move_to_free_list(struct page *page, struct zone *zone,
922 unsigned int order, int migratetype)
924 struct free_area *area = &zone->free_area[order];
926 list_move_tail(&page->lru, &area->free_list[migratetype]);
929 static inline void del_page_from_free_list(struct page *page, struct zone *zone,
932 /* clear reported state and update reported page count */
933 if (page_reported(page))
934 __ClearPageReported(page);
936 list_del(&page->lru);
937 __ClearPageBuddy(page);
938 set_page_private(page, 0);
939 zone->free_area[order].nr_free--;
943 * If this is not the largest possible page, check if the buddy
944 * of the next-highest order is free. If it is, it's possible
945 * that pages are being freed that will coalesce soon. In case,
946 * that is happening, add the free page to the tail of the list
947 * so it's less likely to be used soon and more likely to be merged
948 * as a higher order page
951 buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
952 struct page *page, unsigned int order)
954 struct page *higher_page, *higher_buddy;
955 unsigned long combined_pfn;
957 if (order >= MAX_ORDER - 2)
960 if (!pfn_valid_within(buddy_pfn))
963 combined_pfn = buddy_pfn & pfn;
964 higher_page = page + (combined_pfn - pfn);
965 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
966 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
968 return pfn_valid_within(buddy_pfn) &&
969 page_is_buddy(higher_page, higher_buddy, order + 1);
973 * Freeing function for a buddy system allocator.
975 * The concept of a buddy system is to maintain direct-mapped table
976 * (containing bit values) for memory blocks of various "orders".
977 * The bottom level table contains the map for the smallest allocatable
978 * units of memory (here, pages), and each level above it describes
979 * pairs of units from the levels below, hence, "buddies".
980 * At a high level, all that happens here is marking the table entry
981 * at the bottom level available, and propagating the changes upward
982 * as necessary, plus some accounting needed to play nicely with other
983 * parts of the VM system.
984 * At each level, we keep a list of pages, which are heads of continuous
985 * free pages of length of (1 << order) and marked with PageBuddy.
986 * Page's order is recorded in page_private(page) field.
987 * So when we are allocating or freeing one, we can derive the state of the
988 * other. That is, if we allocate a small block, and both were
989 * free, the remainder of the region must be split into blocks.
990 * If a block is freed, and its buddy is also free, then this
991 * triggers coalescing into a block of larger size.
996 static inline void __free_one_page(struct page *page,
998 struct zone *zone, unsigned int order,
999 int migratetype, fpi_t fpi_flags)
1001 struct capture_control *capc = task_capc(zone);
1002 unsigned long buddy_pfn;
1003 unsigned long combined_pfn;
1004 unsigned int max_order;
1008 max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order);
1010 VM_BUG_ON(!zone_is_initialized(zone));
1011 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
1013 VM_BUG_ON(migratetype == -1);
1014 if (likely(!is_migrate_isolate(migratetype)))
1015 __mod_zone_freepage_state(zone, 1 << order, migratetype);
1017 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
1018 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1021 while (order < max_order) {
1022 if (compaction_capture(capc, page, order, migratetype)) {
1023 __mod_zone_freepage_state(zone, -(1 << order),
1027 buddy_pfn = __find_buddy_pfn(pfn, order);
1028 buddy = page + (buddy_pfn - pfn);
1030 if (!pfn_valid_within(buddy_pfn))
1032 if (!page_is_buddy(page, buddy, order))
1035 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
1036 * merge with it and move up one order.
1038 if (page_is_guard(buddy))
1039 clear_page_guard(zone, buddy, order, migratetype);
1041 del_page_from_free_list(buddy, zone, order);
1042 combined_pfn = buddy_pfn & pfn;
1043 page = page + (combined_pfn - pfn);
1047 if (order < MAX_ORDER - 1) {
1048 /* If we are here, it means order is >= pageblock_order.
1049 * We want to prevent merge between freepages on isolate
1050 * pageblock and normal pageblock. Without this, pageblock
1051 * isolation could cause incorrect freepage or CMA accounting.
1053 * We don't want to hit this code for the more frequent
1054 * low-order merging.
1056 if (unlikely(has_isolate_pageblock(zone))) {
1059 buddy_pfn = __find_buddy_pfn(pfn, order);
1060 buddy = page + (buddy_pfn - pfn);
1061 buddy_mt = get_pageblock_migratetype(buddy);
1063 if (migratetype != buddy_mt
1064 && (is_migrate_isolate(migratetype) ||
1065 is_migrate_isolate(buddy_mt)))
1068 max_order = order + 1;
1069 goto continue_merging;
1073 set_buddy_order(page, order);
1075 if (fpi_flags & FPI_TO_TAIL)
1077 else if (is_shuffle_order(order))
1078 to_tail = shuffle_pick_tail();
1080 to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
1083 add_to_free_list_tail(page, zone, order, migratetype);
1085 add_to_free_list(page, zone, order, migratetype);
1087 /* Notify page reporting subsystem of freed page */
1088 if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY))
1089 page_reporting_notify_free(order);
1093 * A bad page could be due to a number of fields. Instead of multiple branches,
1094 * try and check multiple fields with one check. The caller must do a detailed
1095 * check if necessary.
1097 static inline bool page_expected_state(struct page *page,
1098 unsigned long check_flags)
1100 if (unlikely(atomic_read(&page->_mapcount) != -1))
1103 if (unlikely((unsigned long)page->mapping |
1104 page_ref_count(page) |
1106 (unsigned long)page_memcg(page) |
1108 (page->flags & check_flags)))
1114 static const char *page_bad_reason(struct page *page, unsigned long flags)
1116 const char *bad_reason = NULL;
1118 if (unlikely(atomic_read(&page->_mapcount) != -1))
1119 bad_reason = "nonzero mapcount";
1120 if (unlikely(page->mapping != NULL))
1121 bad_reason = "non-NULL mapping";
1122 if (unlikely(page_ref_count(page) != 0))
1123 bad_reason = "nonzero _refcount";
1124 if (unlikely(page->flags & flags)) {
1125 if (flags == PAGE_FLAGS_CHECK_AT_PREP)
1126 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1128 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1131 if (unlikely(page_memcg(page)))
1132 bad_reason = "page still charged to cgroup";
1137 static void check_free_page_bad(struct page *page)
1140 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_FREE));
1143 static inline int check_free_page(struct page *page)
1145 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
1148 /* Something has gone sideways, find it */
1149 check_free_page_bad(page);
1153 static int free_tail_pages_check(struct page *head_page, struct page *page)
1158 * We rely page->lru.next never has bit 0 set, unless the page
1159 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1161 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
1163 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
1167 switch (page - head_page) {
1169 /* the first tail page: ->mapping may be compound_mapcount() */
1170 if (unlikely(compound_mapcount(page))) {
1171 bad_page(page, "nonzero compound_mapcount");
1177 * the second tail page: ->mapping is
1178 * deferred_list.next -- ignore value.
1182 if (page->mapping != TAIL_MAPPING) {
1183 bad_page(page, "corrupted mapping in tail page");
1188 if (unlikely(!PageTail(page))) {
1189 bad_page(page, "PageTail not set");
1192 if (unlikely(compound_head(page) != head_page)) {
1193 bad_page(page, "compound_head not consistent");
1198 page->mapping = NULL;
1199 clear_compound_head(page);
1203 static void kernel_init_free_pages(struct page *page, int numpages)
1207 /* s390's use of memset() could override KASAN redzones. */
1208 kasan_disable_current();
1209 for (i = 0; i < numpages; i++) {
1210 u8 tag = page_kasan_tag(page + i);
1211 page_kasan_tag_reset(page + i);
1212 clear_highpage(page + i);
1213 page_kasan_tag_set(page + i, tag);
1215 kasan_enable_current();
1218 static __always_inline bool free_pages_prepare(struct page *page,
1219 unsigned int order, bool check_free)
1223 VM_BUG_ON_PAGE(PageTail(page), page);
1225 trace_mm_page_free(page, order);
1227 if (unlikely(PageHWPoison(page)) && !order) {
1229 * Do not let hwpoison pages hit pcplists/buddy
1230 * Untie memcg state and reset page's owner
1232 if (memcg_kmem_enabled() && PageMemcgKmem(page))
1233 __memcg_kmem_uncharge_page(page, order);
1234 reset_page_owner(page, order);
1239 * Check tail pages before head page information is cleared to
1240 * avoid checking PageCompound for order-0 pages.
1242 if (unlikely(order)) {
1243 bool compound = PageCompound(page);
1246 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1249 ClearPageDoubleMap(page);
1250 for (i = 1; i < (1 << order); i++) {
1252 bad += free_tail_pages_check(page, page + i);
1253 if (unlikely(check_free_page(page + i))) {
1257 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1260 if (PageMappingFlags(page))
1261 page->mapping = NULL;
1262 if (memcg_kmem_enabled() && PageMemcgKmem(page))
1263 __memcg_kmem_uncharge_page(page, order);
1265 bad += check_free_page(page);
1269 page_cpupid_reset_last(page);
1270 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1271 reset_page_owner(page, order);
1273 if (!PageHighMem(page)) {
1274 debug_check_no_locks_freed(page_address(page),
1275 PAGE_SIZE << order);
1276 debug_check_no_obj_freed(page_address(page),
1277 PAGE_SIZE << order);
1279 if (want_init_on_free())
1280 kernel_init_free_pages(page, 1 << order);
1282 kernel_poison_pages(page, 1 << order);
1285 * arch_free_page() can make the page's contents inaccessible. s390
1286 * does this. So nothing which can access the page's contents should
1287 * happen after this.
1289 arch_free_page(page, order);
1291 debug_pagealloc_unmap_pages(page, 1 << order);
1293 kasan_free_nondeferred_pages(page, order);
1298 #ifdef CONFIG_DEBUG_VM
1300 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1301 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1302 * moved from pcp lists to free lists.
1304 static bool free_pcp_prepare(struct page *page)
1306 return free_pages_prepare(page, 0, true);
1309 static bool bulkfree_pcp_prepare(struct page *page)
1311 if (debug_pagealloc_enabled_static())
1312 return check_free_page(page);
1318 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1319 * moving from pcp lists to free list in order to reduce overhead. With
1320 * debug_pagealloc enabled, they are checked also immediately when being freed
1323 static bool free_pcp_prepare(struct page *page)
1325 if (debug_pagealloc_enabled_static())
1326 return free_pages_prepare(page, 0, true);
1328 return free_pages_prepare(page, 0, false);
1331 static bool bulkfree_pcp_prepare(struct page *page)
1333 return check_free_page(page);
1335 #endif /* CONFIG_DEBUG_VM */
1337 static inline void prefetch_buddy(struct page *page)
1339 unsigned long pfn = page_to_pfn(page);
1340 unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0);
1341 struct page *buddy = page + (buddy_pfn - pfn);
1347 * Frees a number of pages from the PCP lists
1348 * Assumes all pages on list are in same zone, and of same order.
1349 * count is the number of pages to free.
1351 * If the zone was previously in an "all pages pinned" state then look to
1352 * see if this freeing clears that state.
1354 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1355 * pinned" detection logic.
1357 static void free_pcppages_bulk(struct zone *zone, int count,
1358 struct per_cpu_pages *pcp)
1360 int migratetype = 0;
1362 int prefetch_nr = READ_ONCE(pcp->batch);
1363 bool isolated_pageblocks;
1364 struct page *page, *tmp;
1368 * Ensure proper count is passed which otherwise would stuck in the
1369 * below while (list_empty(list)) loop.
1371 count = min(pcp->count, count);
1373 struct list_head *list;
1376 * Remove pages from lists in a round-robin fashion. A
1377 * batch_free count is maintained that is incremented when an
1378 * empty list is encountered. This is so more pages are freed
1379 * off fuller lists instead of spinning excessively around empty
1384 if (++migratetype == MIGRATE_PCPTYPES)
1386 list = &pcp->lists[migratetype];
1387 } while (list_empty(list));
1389 /* This is the only non-empty list. Free them all. */
1390 if (batch_free == MIGRATE_PCPTYPES)
1394 page = list_last_entry(list, struct page, lru);
1395 /* must delete to avoid corrupting pcp list */
1396 list_del(&page->lru);
1399 if (bulkfree_pcp_prepare(page))
1402 list_add_tail(&page->lru, &head);
1405 * We are going to put the page back to the global
1406 * pool, prefetch its buddy to speed up later access
1407 * under zone->lock. It is believed the overhead of
1408 * an additional test and calculating buddy_pfn here
1409 * can be offset by reduced memory latency later. To
1410 * avoid excessive prefetching due to large count, only
1411 * prefetch buddy for the first pcp->batch nr of pages.
1414 prefetch_buddy(page);
1417 } while (--count && --batch_free && !list_empty(list));
1420 spin_lock(&zone->lock);
1421 isolated_pageblocks = has_isolate_pageblock(zone);
1424 * Use safe version since after __free_one_page(),
1425 * page->lru.next will not point to original list.
1427 list_for_each_entry_safe(page, tmp, &head, lru) {
1428 int mt = get_pcppage_migratetype(page);
1429 /* MIGRATE_ISOLATE page should not go to pcplists */
1430 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1431 /* Pageblock could have been isolated meanwhile */
1432 if (unlikely(isolated_pageblocks))
1433 mt = get_pageblock_migratetype(page);
1435 __free_one_page(page, page_to_pfn(page), zone, 0, mt, FPI_NONE);
1436 trace_mm_page_pcpu_drain(page, 0, mt);
1438 spin_unlock(&zone->lock);
1441 static void free_one_page(struct zone *zone,
1442 struct page *page, unsigned long pfn,
1444 int migratetype, fpi_t fpi_flags)
1446 spin_lock(&zone->lock);
1447 if (unlikely(has_isolate_pageblock(zone) ||
1448 is_migrate_isolate(migratetype))) {
1449 migratetype = get_pfnblock_migratetype(page, pfn);
1451 __free_one_page(page, pfn, zone, order, migratetype, fpi_flags);
1452 spin_unlock(&zone->lock);
1455 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1456 unsigned long zone, int nid)
1458 mm_zero_struct_page(page);
1459 set_page_links(page, zone, nid, pfn);
1460 init_page_count(page);
1461 page_mapcount_reset(page);
1462 page_cpupid_reset_last(page);
1463 page_kasan_tag_reset(page);
1465 INIT_LIST_HEAD(&page->lru);
1466 #ifdef WANT_PAGE_VIRTUAL
1467 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1468 if (!is_highmem_idx(zone))
1469 set_page_address(page, __va(pfn << PAGE_SHIFT));
1473 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1474 static void __meminit init_reserved_page(unsigned long pfn)
1479 if (!early_page_uninitialised(pfn))
1482 nid = early_pfn_to_nid(pfn);
1483 pgdat = NODE_DATA(nid);
1485 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1486 struct zone *zone = &pgdat->node_zones[zid];
1488 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1491 __init_single_page(pfn_to_page(pfn), pfn, zid, nid);
1494 static inline void init_reserved_page(unsigned long pfn)
1497 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1500 * Initialised pages do not have PageReserved set. This function is
1501 * called for each range allocated by the bootmem allocator and
1502 * marks the pages PageReserved. The remaining valid pages are later
1503 * sent to the buddy page allocator.
1505 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1507 unsigned long start_pfn = PFN_DOWN(start);
1508 unsigned long end_pfn = PFN_UP(end);
1510 for (; start_pfn < end_pfn; start_pfn++) {
1511 if (pfn_valid(start_pfn)) {
1512 struct page *page = pfn_to_page(start_pfn);
1514 init_reserved_page(start_pfn);
1516 /* Avoid false-positive PageTail() */
1517 INIT_LIST_HEAD(&page->lru);
1520 * no need for atomic set_bit because the struct
1521 * page is not visible yet so nobody should
1524 __SetPageReserved(page);
1529 static void __free_pages_ok(struct page *page, unsigned int order,
1532 unsigned long flags;
1534 unsigned long pfn = page_to_pfn(page);
1536 if (!free_pages_prepare(page, order, true))
1539 migratetype = get_pfnblock_migratetype(page, pfn);
1540 local_irq_save(flags);
1541 __count_vm_events(PGFREE, 1 << order);
1542 free_one_page(page_zone(page), page, pfn, order, migratetype,
1544 local_irq_restore(flags);
1547 void __free_pages_core(struct page *page, unsigned int order)
1549 unsigned int nr_pages = 1 << order;
1550 struct page *p = page;
1554 * When initializing the memmap, __init_single_page() sets the refcount
1555 * of all pages to 1 ("allocated"/"not free"). We have to set the
1556 * refcount of all involved pages to 0.
1559 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1561 __ClearPageReserved(p);
1562 set_page_count(p, 0);
1564 __ClearPageReserved(p);
1565 set_page_count(p, 0);
1567 atomic_long_add(nr_pages, &page_zone(page)->managed_pages);
1570 * Bypass PCP and place fresh pages right to the tail, primarily
1571 * relevant for memory onlining.
1573 __free_pages_ok(page, order, FPI_TO_TAIL);
1576 #ifdef CONFIG_NEED_MULTIPLE_NODES
1579 * During memory init memblocks map pfns to nids. The search is expensive and
1580 * this caches recent lookups. The implementation of __early_pfn_to_nid
1581 * treats start/end as pfns.
1583 struct mminit_pfnnid_cache {
1584 unsigned long last_start;
1585 unsigned long last_end;
1589 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1592 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1594 static int __meminit __early_pfn_to_nid(unsigned long pfn,
1595 struct mminit_pfnnid_cache *state)
1597 unsigned long start_pfn, end_pfn;
1600 if (state->last_start <= pfn && pfn < state->last_end)
1601 return state->last_nid;
1603 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
1604 if (nid != NUMA_NO_NODE) {
1605 state->last_start = start_pfn;
1606 state->last_end = end_pfn;
1607 state->last_nid = nid;
1613 int __meminit early_pfn_to_nid(unsigned long pfn)
1615 static DEFINE_SPINLOCK(early_pfn_lock);
1618 spin_lock(&early_pfn_lock);
1619 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1621 nid = first_online_node;
1622 spin_unlock(&early_pfn_lock);
1626 #endif /* CONFIG_NEED_MULTIPLE_NODES */
1628 void __init memblock_free_pages(struct page *page, unsigned long pfn,
1631 if (early_page_uninitialised(pfn))
1633 __free_pages_core(page, order);
1637 * Check that the whole (or subset of) a pageblock given by the interval of
1638 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1639 * with the migration of free compaction scanner. The scanners then need to
1640 * use only pfn_valid_within() check for arches that allow holes within
1643 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1645 * It's possible on some configurations to have a setup like node0 node1 node0
1646 * i.e. it's possible that all pages within a zones range of pages do not
1647 * belong to a single zone. We assume that a border between node0 and node1
1648 * can occur within a single pageblock, but not a node0 node1 node0
1649 * interleaving within a single pageblock. It is therefore sufficient to check
1650 * the first and last page of a pageblock and avoid checking each individual
1651 * page in a pageblock.
1653 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1654 unsigned long end_pfn, struct zone *zone)
1656 struct page *start_page;
1657 struct page *end_page;
1659 /* end_pfn is one past the range we are checking */
1662 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1665 start_page = pfn_to_online_page(start_pfn);
1669 if (page_zone(start_page) != zone)
1672 end_page = pfn_to_page(end_pfn);
1674 /* This gives a shorter code than deriving page_zone(end_page) */
1675 if (page_zone_id(start_page) != page_zone_id(end_page))
1681 void set_zone_contiguous(struct zone *zone)
1683 unsigned long block_start_pfn = zone->zone_start_pfn;
1684 unsigned long block_end_pfn;
1686 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1687 for (; block_start_pfn < zone_end_pfn(zone);
1688 block_start_pfn = block_end_pfn,
1689 block_end_pfn += pageblock_nr_pages) {
1691 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1693 if (!__pageblock_pfn_to_page(block_start_pfn,
1694 block_end_pfn, zone))
1699 /* We confirm that there is no hole */
1700 zone->contiguous = true;
1703 void clear_zone_contiguous(struct zone *zone)
1705 zone->contiguous = false;
1708 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1709 static void __init deferred_free_range(unsigned long pfn,
1710 unsigned long nr_pages)
1718 page = pfn_to_page(pfn);
1720 /* Free a large naturally-aligned chunk if possible */
1721 if (nr_pages == pageblock_nr_pages &&
1722 (pfn & (pageblock_nr_pages - 1)) == 0) {
1723 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1724 __free_pages_core(page, pageblock_order);
1728 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1729 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1730 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1731 __free_pages_core(page, 0);
1735 /* Completion tracking for deferred_init_memmap() threads */
1736 static atomic_t pgdat_init_n_undone __initdata;
1737 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1739 static inline void __init pgdat_init_report_one_done(void)
1741 if (atomic_dec_and_test(&pgdat_init_n_undone))
1742 complete(&pgdat_init_all_done_comp);
1746 * Returns true if page needs to be initialized or freed to buddy allocator.
1748 * First we check if pfn is valid on architectures where it is possible to have
1749 * holes within pageblock_nr_pages. On systems where it is not possible, this
1750 * function is optimized out.
1752 * Then, we check if a current large page is valid by only checking the validity
1755 static inline bool __init deferred_pfn_valid(unsigned long pfn)
1757 if (!pfn_valid_within(pfn))
1759 if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
1765 * Free pages to buddy allocator. Try to free aligned pages in
1766 * pageblock_nr_pages sizes.
1768 static void __init deferred_free_pages(unsigned long pfn,
1769 unsigned long end_pfn)
1771 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1772 unsigned long nr_free = 0;
1774 for (; pfn < end_pfn; pfn++) {
1775 if (!deferred_pfn_valid(pfn)) {
1776 deferred_free_range(pfn - nr_free, nr_free);
1778 } else if (!(pfn & nr_pgmask)) {
1779 deferred_free_range(pfn - nr_free, nr_free);
1785 /* Free the last block of pages to allocator */
1786 deferred_free_range(pfn - nr_free, nr_free);
1790 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1791 * by performing it only once every pageblock_nr_pages.
1792 * Return number of pages initialized.
1794 static unsigned long __init deferred_init_pages(struct zone *zone,
1796 unsigned long end_pfn)
1798 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1799 int nid = zone_to_nid(zone);
1800 unsigned long nr_pages = 0;
1801 int zid = zone_idx(zone);
1802 struct page *page = NULL;
1804 for (; pfn < end_pfn; pfn++) {
1805 if (!deferred_pfn_valid(pfn)) {
1808 } else if (!page || !(pfn & nr_pgmask)) {
1809 page = pfn_to_page(pfn);
1813 __init_single_page(page, pfn, zid, nid);
1820 * This function is meant to pre-load the iterator for the zone init.
1821 * Specifically it walks through the ranges until we are caught up to the
1822 * first_init_pfn value and exits there. If we never encounter the value we
1823 * return false indicating there are no valid ranges left.
1826 deferred_init_mem_pfn_range_in_zone(u64 *i, struct zone *zone,
1827 unsigned long *spfn, unsigned long *epfn,
1828 unsigned long first_init_pfn)
1833 * Start out by walking through the ranges in this zone that have
1834 * already been initialized. We don't need to do anything with them
1835 * so we just need to flush them out of the system.
1837 for_each_free_mem_pfn_range_in_zone(j, zone, spfn, epfn) {
1838 if (*epfn <= first_init_pfn)
1840 if (*spfn < first_init_pfn)
1841 *spfn = first_init_pfn;
1850 * Initialize and free pages. We do it in two loops: first we initialize
1851 * struct page, then free to buddy allocator, because while we are
1852 * freeing pages we can access pages that are ahead (computing buddy
1853 * page in __free_one_page()).
1855 * In order to try and keep some memory in the cache we have the loop
1856 * broken along max page order boundaries. This way we will not cause
1857 * any issues with the buddy page computation.
1859 static unsigned long __init
1860 deferred_init_maxorder(u64 *i, struct zone *zone, unsigned long *start_pfn,
1861 unsigned long *end_pfn)
1863 unsigned long mo_pfn = ALIGN(*start_pfn + 1, MAX_ORDER_NR_PAGES);
1864 unsigned long spfn = *start_pfn, epfn = *end_pfn;
1865 unsigned long nr_pages = 0;
1868 /* First we loop through and initialize the page values */
1869 for_each_free_mem_pfn_range_in_zone_from(j, zone, start_pfn, end_pfn) {
1872 if (mo_pfn <= *start_pfn)
1875 t = min(mo_pfn, *end_pfn);
1876 nr_pages += deferred_init_pages(zone, *start_pfn, t);
1878 if (mo_pfn < *end_pfn) {
1879 *start_pfn = mo_pfn;
1884 /* Reset values and now loop through freeing pages as needed */
1887 for_each_free_mem_pfn_range_in_zone_from(j, zone, &spfn, &epfn) {
1893 t = min(mo_pfn, epfn);
1894 deferred_free_pages(spfn, t);
1904 deferred_init_memmap_chunk(unsigned long start_pfn, unsigned long end_pfn,
1907 unsigned long spfn, epfn;
1908 struct zone *zone = arg;
1911 deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, start_pfn);
1914 * Initialize and free pages in MAX_ORDER sized increments so that we
1915 * can avoid introducing any issues with the buddy allocator.
1917 while (spfn < end_pfn) {
1918 deferred_init_maxorder(&i, zone, &spfn, &epfn);
1923 /* An arch may override for more concurrency. */
1925 deferred_page_init_max_threads(const struct cpumask *node_cpumask)
1930 /* Initialise remaining memory on a node */
1931 static int __init deferred_init_memmap(void *data)
1933 pg_data_t *pgdat = data;
1934 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1935 unsigned long spfn = 0, epfn = 0;
1936 unsigned long first_init_pfn, flags;
1937 unsigned long start = jiffies;
1939 int zid, max_threads;
1942 /* Bind memory initialisation thread to a local node if possible */
1943 if (!cpumask_empty(cpumask))
1944 set_cpus_allowed_ptr(current, cpumask);
1946 pgdat_resize_lock(pgdat, &flags);
1947 first_init_pfn = pgdat->first_deferred_pfn;
1948 if (first_init_pfn == ULONG_MAX) {
1949 pgdat_resize_unlock(pgdat, &flags);
1950 pgdat_init_report_one_done();
1954 /* Sanity check boundaries */
1955 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1956 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1957 pgdat->first_deferred_pfn = ULONG_MAX;
1960 * Once we unlock here, the zone cannot be grown anymore, thus if an
1961 * interrupt thread must allocate this early in boot, zone must be
1962 * pre-grown prior to start of deferred page initialization.
1964 pgdat_resize_unlock(pgdat, &flags);
1966 /* Only the highest zone is deferred so find it */
1967 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1968 zone = pgdat->node_zones + zid;
1969 if (first_init_pfn < zone_end_pfn(zone))
1973 /* If the zone is empty somebody else may have cleared out the zone */
1974 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1978 max_threads = deferred_page_init_max_threads(cpumask);
1980 while (spfn < epfn) {
1981 unsigned long epfn_align = ALIGN(epfn, PAGES_PER_SECTION);
1982 struct padata_mt_job job = {
1983 .thread_fn = deferred_init_memmap_chunk,
1986 .size = epfn_align - spfn,
1987 .align = PAGES_PER_SECTION,
1988 .min_chunk = PAGES_PER_SECTION,
1989 .max_threads = max_threads,
1992 padata_do_multithreaded(&job);
1993 deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
1997 /* Sanity check that the next zone really is unpopulated */
1998 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
2000 pr_info("node %d deferred pages initialised in %ums\n",
2001 pgdat->node_id, jiffies_to_msecs(jiffies - start));
2003 pgdat_init_report_one_done();
2008 * If this zone has deferred pages, try to grow it by initializing enough
2009 * deferred pages to satisfy the allocation specified by order, rounded up to
2010 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
2011 * of SECTION_SIZE bytes by initializing struct pages in increments of
2012 * PAGES_PER_SECTION * sizeof(struct page) bytes.
2014 * Return true when zone was grown, otherwise return false. We return true even
2015 * when we grow less than requested, to let the caller decide if there are
2016 * enough pages to satisfy the allocation.
2018 * Note: We use noinline because this function is needed only during boot, and
2019 * it is called from a __ref function _deferred_grow_zone. This way we are
2020 * making sure that it is not inlined into permanent text section.
2022 static noinline bool __init
2023 deferred_grow_zone(struct zone *zone, unsigned int order)
2025 unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
2026 pg_data_t *pgdat = zone->zone_pgdat;
2027 unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
2028 unsigned long spfn, epfn, flags;
2029 unsigned long nr_pages = 0;
2032 /* Only the last zone may have deferred pages */
2033 if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))
2036 pgdat_resize_lock(pgdat, &flags);
2039 * If someone grew this zone while we were waiting for spinlock, return
2040 * true, as there might be enough pages already.
2042 if (first_deferred_pfn != pgdat->first_deferred_pfn) {
2043 pgdat_resize_unlock(pgdat, &flags);
2047 /* If the zone is empty somebody else may have cleared out the zone */
2048 if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
2049 first_deferred_pfn)) {
2050 pgdat->first_deferred_pfn = ULONG_MAX;
2051 pgdat_resize_unlock(pgdat, &flags);
2052 /* Retry only once. */
2053 return first_deferred_pfn != ULONG_MAX;
2057 * Initialize and free pages in MAX_ORDER sized increments so
2058 * that we can avoid introducing any issues with the buddy
2061 while (spfn < epfn) {
2062 /* update our first deferred PFN for this section */
2063 first_deferred_pfn = spfn;
2065 nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn);
2066 touch_nmi_watchdog();
2068 /* We should only stop along section boundaries */
2069 if ((first_deferred_pfn ^ spfn) < PAGES_PER_SECTION)
2072 /* If our quota has been met we can stop here */
2073 if (nr_pages >= nr_pages_needed)
2077 pgdat->first_deferred_pfn = spfn;
2078 pgdat_resize_unlock(pgdat, &flags);
2080 return nr_pages > 0;
2084 * deferred_grow_zone() is __init, but it is called from
2085 * get_page_from_freelist() during early boot until deferred_pages permanently
2086 * disables this call. This is why we have refdata wrapper to avoid warning,
2087 * and to ensure that the function body gets unloaded.
2090 _deferred_grow_zone(struct zone *zone, unsigned int order)
2092 return deferred_grow_zone(zone, order);
2095 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2097 void __init page_alloc_init_late(void)
2102 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2104 /* There will be num_node_state(N_MEMORY) threads */
2105 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
2106 for_each_node_state(nid, N_MEMORY) {
2107 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
2110 /* Block until all are initialised */
2111 wait_for_completion(&pgdat_init_all_done_comp);
2114 * The number of managed pages has changed due to the initialisation
2115 * so the pcpu batch and high limits needs to be updated or the limits
2116 * will be artificially small.
2118 for_each_populated_zone(zone)
2119 zone_pcp_update(zone);
2122 * We initialized the rest of the deferred pages. Permanently disable
2123 * on-demand struct page initialization.
2125 static_branch_disable(&deferred_pages);
2127 /* Reinit limits that are based on free pages after the kernel is up */
2128 files_maxfiles_init();
2133 /* Discard memblock private memory */
2136 for_each_node_state(nid, N_MEMORY)
2137 shuffle_free_memory(NODE_DATA(nid));
2139 for_each_populated_zone(zone)
2140 set_zone_contiguous(zone);
2144 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2145 void __init init_cma_reserved_pageblock(struct page *page)
2147 unsigned i = pageblock_nr_pages;
2148 struct page *p = page;
2151 __ClearPageReserved(p);
2152 set_page_count(p, 0);
2155 set_pageblock_migratetype(page, MIGRATE_CMA);
2157 if (pageblock_order >= MAX_ORDER) {
2158 i = pageblock_nr_pages;
2161 set_page_refcounted(p);
2162 __free_pages(p, MAX_ORDER - 1);
2163 p += MAX_ORDER_NR_PAGES;
2164 } while (i -= MAX_ORDER_NR_PAGES);
2166 set_page_refcounted(page);
2167 __free_pages(page, pageblock_order);
2170 adjust_managed_page_count(page, pageblock_nr_pages);
2175 * The order of subdivision here is critical for the IO subsystem.
2176 * Please do not alter this order without good reasons and regression
2177 * testing. Specifically, as large blocks of memory are subdivided,
2178 * the order in which smaller blocks are delivered depends on the order
2179 * they're subdivided in this function. This is the primary factor
2180 * influencing the order in which pages are delivered to the IO
2181 * subsystem according to empirical testing, and this is also justified
2182 * by considering the behavior of a buddy system containing a single
2183 * large block of memory acted on by a series of small allocations.
2184 * This behavior is a critical factor in sglist merging's success.
2188 static inline void expand(struct zone *zone, struct page *page,
2189 int low, int high, int migratetype)
2191 unsigned long size = 1 << high;
2193 while (high > low) {
2196 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
2199 * Mark as guard pages (or page), that will allow to
2200 * merge back to allocator when buddy will be freed.
2201 * Corresponding page table entries will not be touched,
2202 * pages will stay not present in virtual address space
2204 if (set_page_guard(zone, &page[size], high, migratetype))
2207 add_to_free_list(&page[size], zone, high, migratetype);
2208 set_buddy_order(&page[size], high);
2212 static void check_new_page_bad(struct page *page)
2214 if (unlikely(page->flags & __PG_HWPOISON)) {
2215 /* Don't complain about hwpoisoned pages */
2216 page_mapcount_reset(page); /* remove PageBuddy */
2221 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
2225 * This page is about to be returned from the page allocator
2227 static inline int check_new_page(struct page *page)
2229 if (likely(page_expected_state(page,
2230 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
2233 check_new_page_bad(page);
2237 #ifdef CONFIG_DEBUG_VM
2239 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2240 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2241 * also checked when pcp lists are refilled from the free lists.
2243 static inline bool check_pcp_refill(struct page *page)
2245 if (debug_pagealloc_enabled_static())
2246 return check_new_page(page);
2251 static inline bool check_new_pcp(struct page *page)
2253 return check_new_page(page);
2257 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2258 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2259 * enabled, they are also checked when being allocated from the pcp lists.
2261 static inline bool check_pcp_refill(struct page *page)
2263 return check_new_page(page);
2265 static inline bool check_new_pcp(struct page *page)
2267 if (debug_pagealloc_enabled_static())
2268 return check_new_page(page);
2272 #endif /* CONFIG_DEBUG_VM */
2274 static bool check_new_pages(struct page *page, unsigned int order)
2277 for (i = 0; i < (1 << order); i++) {
2278 struct page *p = page + i;
2280 if (unlikely(check_new_page(p)))
2287 inline void post_alloc_hook(struct page *page, unsigned int order,
2290 set_page_private(page, 0);
2291 set_page_refcounted(page);
2293 arch_alloc_page(page, order);
2294 debug_pagealloc_map_pages(page, 1 << order);
2295 kasan_alloc_pages(page, order);
2296 kernel_unpoison_pages(page, 1 << order);
2297 set_page_owner(page, order, gfp_flags);
2299 if (!want_init_on_free() && want_init_on_alloc(gfp_flags))
2300 kernel_init_free_pages(page, 1 << order);
2303 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
2304 unsigned int alloc_flags)
2306 post_alloc_hook(page, order, gfp_flags);
2308 if (order && (gfp_flags & __GFP_COMP))
2309 prep_compound_page(page, order);
2312 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2313 * allocate the page. The expectation is that the caller is taking
2314 * steps that will free more memory. The caller should avoid the page
2315 * being used for !PFMEMALLOC purposes.
2317 if (alloc_flags & ALLOC_NO_WATERMARKS)
2318 set_page_pfmemalloc(page);
2320 clear_page_pfmemalloc(page);
2324 * Go through the free lists for the given migratetype and remove
2325 * the smallest available page from the freelists
2327 static __always_inline
2328 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
2331 unsigned int current_order;
2332 struct free_area *area;
2335 /* Find a page of the appropriate size in the preferred list */
2336 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
2337 area = &(zone->free_area[current_order]);
2338 page = get_page_from_free_area(area, migratetype);
2341 del_page_from_free_list(page, zone, current_order);
2342 expand(zone, page, order, current_order, migratetype);
2343 set_pcppage_migratetype(page, migratetype);
2352 * This array describes the order lists are fallen back to when
2353 * the free lists for the desirable migrate type are depleted
2355 static int fallbacks[MIGRATE_TYPES][3] = {
2356 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2357 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
2358 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2360 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
2362 #ifdef CONFIG_MEMORY_ISOLATION
2363 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
2368 static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2371 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
2374 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2375 unsigned int order) { return NULL; }
2379 * Move the free pages in a range to the freelist tail of the requested type.
2380 * Note that start_page and end_pages are not aligned on a pageblock
2381 * boundary. If alignment is required, use move_freepages_block()
2383 static int move_freepages(struct zone *zone,
2384 struct page *start_page, struct page *end_page,
2385 int migratetype, int *num_movable)
2389 int pages_moved = 0;
2391 for (page = start_page; page <= end_page;) {
2392 if (!pfn_valid_within(page_to_pfn(page))) {
2397 if (!PageBuddy(page)) {
2399 * We assume that pages that could be isolated for
2400 * migration are movable. But we don't actually try
2401 * isolating, as that would be expensive.
2404 (PageLRU(page) || __PageMovable(page)))
2411 /* Make sure we are not inadvertently changing nodes */
2412 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
2413 VM_BUG_ON_PAGE(page_zone(page) != zone, page);
2415 order = buddy_order(page);
2416 move_to_free_list(page, zone, order, migratetype);
2418 pages_moved += 1 << order;
2424 int move_freepages_block(struct zone *zone, struct page *page,
2425 int migratetype, int *num_movable)
2427 unsigned long start_pfn, end_pfn;
2428 struct page *start_page, *end_page;
2433 start_pfn = page_to_pfn(page);
2434 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
2435 start_page = pfn_to_page(start_pfn);
2436 end_page = start_page + pageblock_nr_pages - 1;
2437 end_pfn = start_pfn + pageblock_nr_pages - 1;
2439 /* Do not cross zone boundaries */
2440 if (!zone_spans_pfn(zone, start_pfn))
2442 if (!zone_spans_pfn(zone, end_pfn))
2445 return move_freepages(zone, start_page, end_page, migratetype,
2449 static void change_pageblock_range(struct page *pageblock_page,
2450 int start_order, int migratetype)
2452 int nr_pageblocks = 1 << (start_order - pageblock_order);
2454 while (nr_pageblocks--) {
2455 set_pageblock_migratetype(pageblock_page, migratetype);
2456 pageblock_page += pageblock_nr_pages;
2461 * When we are falling back to another migratetype during allocation, try to
2462 * steal extra free pages from the same pageblocks to satisfy further
2463 * allocations, instead of polluting multiple pageblocks.
2465 * If we are stealing a relatively large buddy page, it is likely there will
2466 * be more free pages in the pageblock, so try to steal them all. For
2467 * reclaimable and unmovable allocations, we steal regardless of page size,
2468 * as fragmentation caused by those allocations polluting movable pageblocks
2469 * is worse than movable allocations stealing from unmovable and reclaimable
2472 static bool can_steal_fallback(unsigned int order, int start_mt)
2475 * Leaving this order check is intended, although there is
2476 * relaxed order check in next check. The reason is that
2477 * we can actually steal whole pageblock if this condition met,
2478 * but, below check doesn't guarantee it and that is just heuristic
2479 * so could be changed anytime.
2481 if (order >= pageblock_order)
2484 if (order >= pageblock_order / 2 ||
2485 start_mt == MIGRATE_RECLAIMABLE ||
2486 start_mt == MIGRATE_UNMOVABLE ||
2487 page_group_by_mobility_disabled)
2493 static inline bool boost_watermark(struct zone *zone)
2495 unsigned long max_boost;
2497 if (!watermark_boost_factor)
2500 * Don't bother in zones that are unlikely to produce results.
2501 * On small machines, including kdump capture kernels running
2502 * in a small area, boosting the watermark can cause an out of
2503 * memory situation immediately.
2505 if ((pageblock_nr_pages * 4) > zone_managed_pages(zone))
2508 max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
2509 watermark_boost_factor, 10000);
2512 * high watermark may be uninitialised if fragmentation occurs
2513 * very early in boot so do not boost. We do not fall
2514 * through and boost by pageblock_nr_pages as failing
2515 * allocations that early means that reclaim is not going
2516 * to help and it may even be impossible to reclaim the
2517 * boosted watermark resulting in a hang.
2522 max_boost = max(pageblock_nr_pages, max_boost);
2524 zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages,
2531 * This function implements actual steal behaviour. If order is large enough,
2532 * we can steal whole pageblock. If not, we first move freepages in this
2533 * pageblock to our migratetype and determine how many already-allocated pages
2534 * are there in the pageblock with a compatible migratetype. If at least half
2535 * of pages are free or compatible, we can change migratetype of the pageblock
2536 * itself, so pages freed in the future will be put on the correct free list.
2538 static void steal_suitable_fallback(struct zone *zone, struct page *page,
2539 unsigned int alloc_flags, int start_type, bool whole_block)
2541 unsigned int current_order = buddy_order(page);
2542 int free_pages, movable_pages, alike_pages;
2545 old_block_type = get_pageblock_migratetype(page);
2548 * This can happen due to races and we want to prevent broken
2549 * highatomic accounting.
2551 if (is_migrate_highatomic(old_block_type))
2554 /* Take ownership for orders >= pageblock_order */
2555 if (current_order >= pageblock_order) {
2556 change_pageblock_range(page, current_order, start_type);
2561 * Boost watermarks to increase reclaim pressure to reduce the
2562 * likelihood of future fallbacks. Wake kswapd now as the node
2563 * may be balanced overall and kswapd will not wake naturally.
2565 if (boost_watermark(zone) && (alloc_flags & ALLOC_KSWAPD))
2566 set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
2568 /* We are not allowed to try stealing from the whole block */
2572 free_pages = move_freepages_block(zone, page, start_type,
2575 * Determine how many pages are compatible with our allocation.
2576 * For movable allocation, it's the number of movable pages which
2577 * we just obtained. For other types it's a bit more tricky.
2579 if (start_type == MIGRATE_MOVABLE) {
2580 alike_pages = movable_pages;
2583 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2584 * to MOVABLE pageblock, consider all non-movable pages as
2585 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2586 * vice versa, be conservative since we can't distinguish the
2587 * exact migratetype of non-movable pages.
2589 if (old_block_type == MIGRATE_MOVABLE)
2590 alike_pages = pageblock_nr_pages
2591 - (free_pages + movable_pages);
2596 /* moving whole block can fail due to zone boundary conditions */
2601 * If a sufficient number of pages in the block are either free or of
2602 * comparable migratability as our allocation, claim the whole block.
2604 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2605 page_group_by_mobility_disabled)
2606 set_pageblock_migratetype(page, start_type);
2611 move_to_free_list(page, zone, current_order, start_type);
2615 * Check whether there is a suitable fallback freepage with requested order.
2616 * If only_stealable is true, this function returns fallback_mt only if
2617 * we can steal other freepages all together. This would help to reduce
2618 * fragmentation due to mixed migratetype pages in one pageblock.
2620 int find_suitable_fallback(struct free_area *area, unsigned int order,
2621 int migratetype, bool only_stealable, bool *can_steal)
2626 if (area->nr_free == 0)
2631 fallback_mt = fallbacks[migratetype][i];
2632 if (fallback_mt == MIGRATE_TYPES)
2635 if (free_area_empty(area, fallback_mt))
2638 if (can_steal_fallback(order, migratetype))
2641 if (!only_stealable)
2652 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2653 * there are no empty page blocks that contain a page with a suitable order
2655 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2656 unsigned int alloc_order)
2659 unsigned long max_managed, flags;
2662 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2663 * Check is race-prone but harmless.
2665 max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;
2666 if (zone->nr_reserved_highatomic >= max_managed)
2669 spin_lock_irqsave(&zone->lock, flags);
2671 /* Recheck the nr_reserved_highatomic limit under the lock */
2672 if (zone->nr_reserved_highatomic >= max_managed)
2676 mt = get_pageblock_migratetype(page);
2677 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2678 && !is_migrate_cma(mt)) {
2679 zone->nr_reserved_highatomic += pageblock_nr_pages;
2680 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2681 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2685 spin_unlock_irqrestore(&zone->lock, flags);
2689 * Used when an allocation is about to fail under memory pressure. This
2690 * potentially hurts the reliability of high-order allocations when under
2691 * intense memory pressure but failed atomic allocations should be easier
2692 * to recover from than an OOM.
2694 * If @force is true, try to unreserve a pageblock even though highatomic
2695 * pageblock is exhausted.
2697 static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2700 struct zonelist *zonelist = ac->zonelist;
2701 unsigned long flags;
2708 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
2711 * Preserve at least one pageblock unless memory pressure
2714 if (!force && zone->nr_reserved_highatomic <=
2718 spin_lock_irqsave(&zone->lock, flags);
2719 for (order = 0; order < MAX_ORDER; order++) {
2720 struct free_area *area = &(zone->free_area[order]);
2722 page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
2727 * In page freeing path, migratetype change is racy so
2728 * we can counter several free pages in a pageblock
2729 * in this loop althoug we changed the pageblock type
2730 * from highatomic to ac->migratetype. So we should
2731 * adjust the count once.
2733 if (is_migrate_highatomic_page(page)) {
2735 * It should never happen but changes to
2736 * locking could inadvertently allow a per-cpu
2737 * drain to add pages to MIGRATE_HIGHATOMIC
2738 * while unreserving so be safe and watch for
2741 zone->nr_reserved_highatomic -= min(
2743 zone->nr_reserved_highatomic);
2747 * Convert to ac->migratetype and avoid the normal
2748 * pageblock stealing heuristics. Minimally, the caller
2749 * is doing the work and needs the pages. More
2750 * importantly, if the block was always converted to
2751 * MIGRATE_UNMOVABLE or another type then the number
2752 * of pageblocks that cannot be completely freed
2755 set_pageblock_migratetype(page, ac->migratetype);
2756 ret = move_freepages_block(zone, page, ac->migratetype,
2759 spin_unlock_irqrestore(&zone->lock, flags);
2763 spin_unlock_irqrestore(&zone->lock, flags);
2770 * Try finding a free buddy page on the fallback list and put it on the free
2771 * list of requested migratetype, possibly along with other pages from the same
2772 * block, depending on fragmentation avoidance heuristics. Returns true if
2773 * fallback was found so that __rmqueue_smallest() can grab it.
2775 * The use of signed ints for order and current_order is a deliberate
2776 * deviation from the rest of this file, to make the for loop
2777 * condition simpler.
2779 static __always_inline bool
2780 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
2781 unsigned int alloc_flags)
2783 struct free_area *area;
2785 int min_order = order;
2791 * Do not steal pages from freelists belonging to other pageblocks
2792 * i.e. orders < pageblock_order. If there are no local zones free,
2793 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2795 if (alloc_flags & ALLOC_NOFRAGMENT)
2796 min_order = pageblock_order;
2799 * Find the largest available free page in the other list. This roughly
2800 * approximates finding the pageblock with the most free pages, which
2801 * would be too costly to do exactly.
2803 for (current_order = MAX_ORDER - 1; current_order >= min_order;
2805 area = &(zone->free_area[current_order]);
2806 fallback_mt = find_suitable_fallback(area, current_order,
2807 start_migratetype, false, &can_steal);
2808 if (fallback_mt == -1)
2812 * We cannot steal all free pages from the pageblock and the
2813 * requested migratetype is movable. In that case it's better to
2814 * steal and split the smallest available page instead of the
2815 * largest available page, because even if the next movable
2816 * allocation falls back into a different pageblock than this
2817 * one, it won't cause permanent fragmentation.
2819 if (!can_steal && start_migratetype == MIGRATE_MOVABLE
2820 && current_order > order)
2829 for (current_order = order; current_order < MAX_ORDER;
2831 area = &(zone->free_area[current_order]);
2832 fallback_mt = find_suitable_fallback(area, current_order,
2833 start_migratetype, false, &can_steal);
2834 if (fallback_mt != -1)
2839 * This should not happen - we already found a suitable fallback
2840 * when looking for the largest page.
2842 VM_BUG_ON(current_order == MAX_ORDER);
2845 page = get_page_from_free_area(area, fallback_mt);
2847 steal_suitable_fallback(zone, page, alloc_flags, start_migratetype,
2850 trace_mm_page_alloc_extfrag(page, order, current_order,
2851 start_migratetype, fallback_mt);
2858 * Do the hard work of removing an element from the buddy allocator.
2859 * Call me with the zone->lock already held.
2861 static __always_inline struct page *
2862 __rmqueue(struct zone *zone, unsigned int order, int migratetype,
2863 unsigned int alloc_flags)
2867 if (IS_ENABLED(CONFIG_CMA)) {
2869 * Balance movable allocations between regular and CMA areas by
2870 * allocating from CMA when over half of the zone's free memory
2871 * is in the CMA area.
2873 if (alloc_flags & ALLOC_CMA &&
2874 zone_page_state(zone, NR_FREE_CMA_PAGES) >
2875 zone_page_state(zone, NR_FREE_PAGES) / 2) {
2876 page = __rmqueue_cma_fallback(zone, order);
2882 page = __rmqueue_smallest(zone, order, migratetype);
2883 if (unlikely(!page)) {
2884 if (alloc_flags & ALLOC_CMA)
2885 page = __rmqueue_cma_fallback(zone, order);
2887 if (!page && __rmqueue_fallback(zone, order, migratetype,
2893 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2898 * Obtain a specified number of elements from the buddy allocator, all under
2899 * a single hold of the lock, for efficiency. Add them to the supplied list.
2900 * Returns the number of new pages which were placed at *list.
2902 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2903 unsigned long count, struct list_head *list,
2904 int migratetype, unsigned int alloc_flags)
2908 spin_lock(&zone->lock);
2909 for (i = 0; i < count; ++i) {
2910 struct page *page = __rmqueue(zone, order, migratetype,
2912 if (unlikely(page == NULL))
2915 if (unlikely(check_pcp_refill(page)))
2919 * Split buddy pages returned by expand() are received here in
2920 * physical page order. The page is added to the tail of
2921 * caller's list. From the callers perspective, the linked list
2922 * is ordered by page number under some conditions. This is
2923 * useful for IO devices that can forward direction from the
2924 * head, thus also in the physical page order. This is useful
2925 * for IO devices that can merge IO requests if the physical
2926 * pages are ordered properly.
2928 list_add_tail(&page->lru, list);
2930 if (is_migrate_cma(get_pcppage_migratetype(page)))
2931 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2936 * i pages were removed from the buddy list even if some leak due
2937 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2938 * on i. Do not confuse with 'alloced' which is the number of
2939 * pages added to the pcp list.
2941 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2942 spin_unlock(&zone->lock);
2948 * Called from the vmstat counter updater to drain pagesets of this
2949 * currently executing processor on remote nodes after they have
2952 * Note that this function must be called with the thread pinned to
2953 * a single processor.
2955 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2957 unsigned long flags;
2958 int to_drain, batch;
2960 local_irq_save(flags);
2961 batch = READ_ONCE(pcp->batch);
2962 to_drain = min(pcp->count, batch);
2964 free_pcppages_bulk(zone, to_drain, pcp);
2965 local_irq_restore(flags);
2970 * Drain pcplists of the indicated processor and zone.
2972 * The processor must either be the current processor and the
2973 * thread pinned to the current processor or a processor that
2976 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2978 unsigned long flags;
2979 struct per_cpu_pageset *pset;
2980 struct per_cpu_pages *pcp;
2982 local_irq_save(flags);
2983 pset = per_cpu_ptr(zone->pageset, cpu);
2987 free_pcppages_bulk(zone, pcp->count, pcp);
2988 local_irq_restore(flags);
2992 * Drain pcplists of all zones on the indicated processor.
2994 * The processor must either be the current processor and the
2995 * thread pinned to the current processor or a processor that
2998 static void drain_pages(unsigned int cpu)
3002 for_each_populated_zone(zone) {
3003 drain_pages_zone(cpu, zone);
3008 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
3010 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
3011 * the single zone's pages.
3013 void drain_local_pages(struct zone *zone)
3015 int cpu = smp_processor_id();
3018 drain_pages_zone(cpu, zone);
3023 static void drain_local_pages_wq(struct work_struct *work)
3025 struct pcpu_drain *drain;
3027 drain = container_of(work, struct pcpu_drain, work);
3030 * drain_all_pages doesn't use proper cpu hotplug protection so
3031 * we can race with cpu offline when the WQ can move this from
3032 * a cpu pinned worker to an unbound one. We can operate on a different
3033 * cpu which is allright but we also have to make sure to not move to
3037 drain_local_pages(drain->zone);
3042 * The implementation of drain_all_pages(), exposing an extra parameter to
3043 * drain on all cpus.
3045 * drain_all_pages() is optimized to only execute on cpus where pcplists are
3046 * not empty. The check for non-emptiness can however race with a free to
3047 * pcplist that has not yet increased the pcp->count from 0 to 1. Callers
3048 * that need the guarantee that every CPU has drained can disable the
3049 * optimizing racy check.
3051 static void __drain_all_pages(struct zone *zone, bool force_all_cpus)
3056 * Allocate in the BSS so we wont require allocation in
3057 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
3059 static cpumask_t cpus_with_pcps;
3062 * Make sure nobody triggers this path before mm_percpu_wq is fully
3065 if (WARN_ON_ONCE(!mm_percpu_wq))
3069 * Do not drain if one is already in progress unless it's specific to
3070 * a zone. Such callers are primarily CMA and memory hotplug and need
3071 * the drain to be complete when the call returns.
3073 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
3076 mutex_lock(&pcpu_drain_mutex);
3080 * We don't care about racing with CPU hotplug event
3081 * as offline notification will cause the notified
3082 * cpu to drain that CPU pcps and on_each_cpu_mask
3083 * disables preemption as part of its processing
3085 for_each_online_cpu(cpu) {
3086 struct per_cpu_pageset *pcp;
3088 bool has_pcps = false;
3090 if (force_all_cpus) {
3092 * The pcp.count check is racy, some callers need a
3093 * guarantee that no cpu is missed.
3097 pcp = per_cpu_ptr(zone->pageset, cpu);
3101 for_each_populated_zone(z) {
3102 pcp = per_cpu_ptr(z->pageset, cpu);
3103 if (pcp->pcp.count) {
3111 cpumask_set_cpu(cpu, &cpus_with_pcps);
3113 cpumask_clear_cpu(cpu, &cpus_with_pcps);
3116 for_each_cpu(cpu, &cpus_with_pcps) {
3117 struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu);
3120 INIT_WORK(&drain->work, drain_local_pages_wq);
3121 queue_work_on(cpu, mm_percpu_wq, &drain->work);
3123 for_each_cpu(cpu, &cpus_with_pcps)
3124 flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work);
3126 mutex_unlock(&pcpu_drain_mutex);
3130 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
3132 * When zone parameter is non-NULL, spill just the single zone's pages.
3134 * Note that this can be extremely slow as the draining happens in a workqueue.
3136 void drain_all_pages(struct zone *zone)
3138 __drain_all_pages(zone, false);
3141 #ifdef CONFIG_HIBERNATION
3144 * Touch the watchdog for every WD_PAGE_COUNT pages.
3146 #define WD_PAGE_COUNT (128*1024)
3148 void mark_free_pages(struct zone *zone)
3150 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
3151 unsigned long flags;
3152 unsigned int order, t;
3155 if (zone_is_empty(zone))
3158 spin_lock_irqsave(&zone->lock, flags);
3160 max_zone_pfn = zone_end_pfn(zone);
3161 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
3162 if (pfn_valid(pfn)) {
3163 page = pfn_to_page(pfn);
3165 if (!--page_count) {
3166 touch_nmi_watchdog();
3167 page_count = WD_PAGE_COUNT;
3170 if (page_zone(page) != zone)
3173 if (!swsusp_page_is_forbidden(page))
3174 swsusp_unset_page_free(page);
3177 for_each_migratetype_order(order, t) {
3178 list_for_each_entry(page,
3179 &zone->free_area[order].free_list[t], lru) {
3182 pfn = page_to_pfn(page);
3183 for (i = 0; i < (1UL << order); i++) {
3184 if (!--page_count) {
3185 touch_nmi_watchdog();
3186 page_count = WD_PAGE_COUNT;
3188 swsusp_set_page_free(pfn_to_page(pfn + i));
3192 spin_unlock_irqrestore(&zone->lock, flags);
3194 #endif /* CONFIG_PM */
3196 static bool free_unref_page_prepare(struct page *page, unsigned long pfn)
3200 if (!free_pcp_prepare(page))
3203 migratetype = get_pfnblock_migratetype(page, pfn);
3204 set_pcppage_migratetype(page, migratetype);
3208 static void free_unref_page_commit(struct page *page, unsigned long pfn)
3210 struct zone *zone = page_zone(page);
3211 struct per_cpu_pages *pcp;
3214 migratetype = get_pcppage_migratetype(page);
3215 __count_vm_event(PGFREE);
3218 * We only track unmovable, reclaimable and movable on pcp lists.
3219 * Free ISOLATE pages back to the allocator because they are being
3220 * offlined but treat HIGHATOMIC as movable pages so we can get those
3221 * areas back if necessary. Otherwise, we may have to free
3222 * excessively into the page allocator
3224 if (migratetype >= MIGRATE_PCPTYPES) {
3225 if (unlikely(is_migrate_isolate(migratetype))) {
3226 free_one_page(zone, page, pfn, 0, migratetype,
3230 migratetype = MIGRATE_MOVABLE;
3233 pcp = &this_cpu_ptr(zone->pageset)->pcp;
3234 list_add(&page->lru, &pcp->lists[migratetype]);
3236 if (pcp->count >= READ_ONCE(pcp->high))
3237 free_pcppages_bulk(zone, READ_ONCE(pcp->batch), pcp);
3241 * Free a 0-order page
3243 void free_unref_page(struct page *page)
3245 unsigned long flags;
3246 unsigned long pfn = page_to_pfn(page);
3248 if (!free_unref_page_prepare(page, pfn))
3251 local_irq_save(flags);
3252 free_unref_page_commit(page, pfn);
3253 local_irq_restore(flags);
3257 * Free a list of 0-order pages
3259 void free_unref_page_list(struct list_head *list)
3261 struct page *page, *next;
3262 unsigned long flags, pfn;
3263 int batch_count = 0;
3265 /* Prepare pages for freeing */
3266 list_for_each_entry_safe(page, next, list, lru) {
3267 pfn = page_to_pfn(page);
3268 if (!free_unref_page_prepare(page, pfn))
3269 list_del(&page->lru);
3270 set_page_private(page, pfn);
3273 local_irq_save(flags);
3274 list_for_each_entry_safe(page, next, list, lru) {
3275 unsigned long pfn = page_private(page);
3277 set_page_private(page, 0);
3278 trace_mm_page_free_batched(page);
3279 free_unref_page_commit(page, pfn);
3282 * Guard against excessive IRQ disabled times when we get
3283 * a large list of pages to free.
3285 if (++batch_count == SWAP_CLUSTER_MAX) {
3286 local_irq_restore(flags);
3288 local_irq_save(flags);
3291 local_irq_restore(flags);
3295 * split_page takes a non-compound higher-order page, and splits it into
3296 * n (1<<order) sub-pages: page[0..n]
3297 * Each sub-page must be freed individually.
3299 * Note: this is probably too low level an operation for use in drivers.
3300 * Please consult with lkml before using this in your driver.
3302 void split_page(struct page *page, unsigned int order)
3306 VM_BUG_ON_PAGE(PageCompound(page), page);
3307 VM_BUG_ON_PAGE(!page_count(page), page);
3309 for (i = 1; i < (1 << order); i++)
3310 set_page_refcounted(page + i);
3311 split_page_owner(page, 1 << order);
3313 EXPORT_SYMBOL_GPL(split_page);
3315 int __isolate_free_page(struct page *page, unsigned int order)
3317 unsigned long watermark;
3321 BUG_ON(!PageBuddy(page));
3323 zone = page_zone(page);
3324 mt = get_pageblock_migratetype(page);
3326 if (!is_migrate_isolate(mt)) {
3328 * Obey watermarks as if the page was being allocated. We can
3329 * emulate a high-order watermark check with a raised order-0
3330 * watermark, because we already know our high-order page
3333 watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
3334 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
3337 __mod_zone_freepage_state(zone, -(1UL << order), mt);
3340 /* Remove page from free list */
3342 del_page_from_free_list(page, zone, order);
3345 * Set the pageblock if the isolated page is at least half of a
3348 if (order >= pageblock_order - 1) {
3349 struct page *endpage = page + (1 << order) - 1;
3350 for (; page < endpage; page += pageblock_nr_pages) {
3351 int mt = get_pageblock_migratetype(page);
3352 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
3353 && !is_migrate_highatomic(mt))
3354 set_pageblock_migratetype(page,
3360 return 1UL << order;
3364 * __putback_isolated_page - Return a now-isolated page back where we got it
3365 * @page: Page that was isolated
3366 * @order: Order of the isolated page
3367 * @mt: The page's pageblock's migratetype
3369 * This function is meant to return a page pulled from the free lists via
3370 * __isolate_free_page back to the free lists they were pulled from.
3372 void __putback_isolated_page(struct page *page, unsigned int order, int mt)
3374 struct zone *zone = page_zone(page);
3376 /* zone lock should be held when this function is called */
3377 lockdep_assert_held(&zone->lock);
3379 /* Return isolated page to tail of freelist. */
3380 __free_one_page(page, page_to_pfn(page), zone, order, mt,
3381 FPI_SKIP_REPORT_NOTIFY | FPI_TO_TAIL);
3385 * Update NUMA hit/miss statistics
3387 * Must be called with interrupts disabled.
3389 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
3392 enum numa_stat_item local_stat = NUMA_LOCAL;
3394 /* skip numa counters update if numa stats is disabled */
3395 if (!static_branch_likely(&vm_numa_stat_key))
3398 if (zone_to_nid(z) != numa_node_id())
3399 local_stat = NUMA_OTHER;
3401 if (zone_to_nid(z) == zone_to_nid(preferred_zone))
3402 __inc_numa_state(z, NUMA_HIT);
3404 __inc_numa_state(z, NUMA_MISS);
3405 __inc_numa_state(preferred_zone, NUMA_FOREIGN);
3407 __inc_numa_state(z, local_stat);
3411 /* Remove page from the per-cpu list, caller must protect the list */
3412 static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
3413 unsigned int alloc_flags,
3414 struct per_cpu_pages *pcp,
3415 struct list_head *list)
3420 if (list_empty(list)) {
3421 pcp->count += rmqueue_bulk(zone, 0,
3422 READ_ONCE(pcp->batch), list,
3423 migratetype, alloc_flags);
3424 if (unlikely(list_empty(list)))
3428 page = list_first_entry(list, struct page, lru);
3429 list_del(&page->lru);
3431 } while (check_new_pcp(page));
3436 /* Lock and remove page from the per-cpu list */
3437 static struct page *rmqueue_pcplist(struct zone *preferred_zone,
3438 struct zone *zone, gfp_t gfp_flags,
3439 int migratetype, unsigned int alloc_flags)
3441 struct per_cpu_pages *pcp;
3442 struct list_head *list;
3444 unsigned long flags;
3446 local_irq_save(flags);
3447 pcp = &this_cpu_ptr(zone->pageset)->pcp;
3448 list = &pcp->lists[migratetype];
3449 page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list);
3451 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1);
3452 zone_statistics(preferred_zone, zone);
3454 local_irq_restore(flags);
3459 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3462 struct page *rmqueue(struct zone *preferred_zone,
3463 struct zone *zone, unsigned int order,
3464 gfp_t gfp_flags, unsigned int alloc_flags,
3467 unsigned long flags;
3470 if (likely(order == 0)) {
3472 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3473 * we need to skip it when CMA area isn't allowed.
3475 if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA ||
3476 migratetype != MIGRATE_MOVABLE) {
3477 page = rmqueue_pcplist(preferred_zone, zone, gfp_flags,
3478 migratetype, alloc_flags);
3484 * We most definitely don't want callers attempting to
3485 * allocate greater than order-1 page units with __GFP_NOFAIL.
3487 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
3488 spin_lock_irqsave(&zone->lock, flags);
3493 * order-0 request can reach here when the pcplist is skipped
3494 * due to non-CMA allocation context. HIGHATOMIC area is
3495 * reserved for high-order atomic allocation, so order-0
3496 * request should skip it.
3498 if (order > 0 && alloc_flags & ALLOC_HARDER) {
3499 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
3501 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3504 page = __rmqueue(zone, order, migratetype, alloc_flags);
3505 } while (page && check_new_pages(page, order));
3506 spin_unlock(&zone->lock);
3509 __mod_zone_freepage_state(zone, -(1 << order),
3510 get_pcppage_migratetype(page));
3512 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
3513 zone_statistics(preferred_zone, zone);
3514 local_irq_restore(flags);
3517 /* Separate test+clear to avoid unnecessary atomics */
3518 if (test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags)) {
3519 clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
3520 wakeup_kswapd(zone, 0, 0, zone_idx(zone));
3523 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
3527 local_irq_restore(flags);
3531 #ifdef CONFIG_FAIL_PAGE_ALLOC
3534 struct fault_attr attr;
3536 bool ignore_gfp_highmem;
3537 bool ignore_gfp_reclaim;
3539 } fail_page_alloc = {
3540 .attr = FAULT_ATTR_INITIALIZER,
3541 .ignore_gfp_reclaim = true,
3542 .ignore_gfp_highmem = true,
3546 static int __init setup_fail_page_alloc(char *str)
3548 return setup_fault_attr(&fail_page_alloc.attr, str);
3550 __setup("fail_page_alloc=", setup_fail_page_alloc);
3552 static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3554 if (order < fail_page_alloc.min_order)
3556 if (gfp_mask & __GFP_NOFAIL)
3558 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
3560 if (fail_page_alloc.ignore_gfp_reclaim &&
3561 (gfp_mask & __GFP_DIRECT_RECLAIM))
3564 return should_fail(&fail_page_alloc.attr, 1 << order);
3567 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3569 static int __init fail_page_alloc_debugfs(void)
3571 umode_t mode = S_IFREG | 0600;
3574 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
3575 &fail_page_alloc.attr);
3577 debugfs_create_bool("ignore-gfp-wait", mode, dir,
3578 &fail_page_alloc.ignore_gfp_reclaim);
3579 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
3580 &fail_page_alloc.ignore_gfp_highmem);
3581 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);
3586 late_initcall(fail_page_alloc_debugfs);
3588 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3590 #else /* CONFIG_FAIL_PAGE_ALLOC */
3592 static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3597 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3599 noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3601 return __should_fail_alloc_page(gfp_mask, order);
3603 ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
3605 static inline long __zone_watermark_unusable_free(struct zone *z,
3606 unsigned int order, unsigned int alloc_flags)
3608 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3609 long unusable_free = (1 << order) - 1;
3612 * If the caller does not have rights to ALLOC_HARDER then subtract
3613 * the high-atomic reserves. This will over-estimate the size of the
3614 * atomic reserve but it avoids a search.
3616 if (likely(!alloc_harder))
3617 unusable_free += z->nr_reserved_highatomic;
3620 /* If allocation can't use CMA areas don't use free CMA pages */
3621 if (!(alloc_flags & ALLOC_CMA))
3622 unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES);
3625 return unusable_free;
3629 * Return true if free base pages are above 'mark'. For high-order checks it
3630 * will return true of the order-0 watermark is reached and there is at least
3631 * one free page of a suitable size. Checking now avoids taking the zone lock
3632 * to check in the allocation paths if no pages are free.
3634 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3635 int highest_zoneidx, unsigned int alloc_flags,
3640 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3642 /* free_pages may go negative - that's OK */
3643 free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags);
3645 if (alloc_flags & ALLOC_HIGH)
3648 if (unlikely(alloc_harder)) {
3650 * OOM victims can try even harder than normal ALLOC_HARDER
3651 * users on the grounds that it's definitely going to be in
3652 * the exit path shortly and free memory. Any allocation it
3653 * makes during the free path will be small and short-lived.
3655 if (alloc_flags & ALLOC_OOM)
3662 * Check watermarks for an order-0 allocation request. If these
3663 * are not met, then a high-order request also cannot go ahead
3664 * even if a suitable page happened to be free.
3666 if (free_pages <= min + z->lowmem_reserve[highest_zoneidx])
3669 /* If this is an order-0 request then the watermark is fine */
3673 /* For a high-order request, check at least one suitable page is free */
3674 for (o = order; o < MAX_ORDER; o++) {
3675 struct free_area *area = &z->free_area[o];
3681 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
3682 if (!free_area_empty(area, mt))
3687 if ((alloc_flags & ALLOC_CMA) &&
3688 !free_area_empty(area, MIGRATE_CMA)) {
3692 if (alloc_harder && !free_area_empty(area, MIGRATE_HIGHATOMIC))
3698 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3699 int highest_zoneidx, unsigned int alloc_flags)
3701 return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
3702 zone_page_state(z, NR_FREE_PAGES));
3705 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
3706 unsigned long mark, int highest_zoneidx,
3707 unsigned int alloc_flags, gfp_t gfp_mask)
3711 free_pages = zone_page_state(z, NR_FREE_PAGES);
3714 * Fast check for order-0 only. If this fails then the reserves
3715 * need to be calculated.
3720 fast_free = free_pages;
3721 fast_free -= __zone_watermark_unusable_free(z, 0, alloc_flags);
3722 if (fast_free > mark + z->lowmem_reserve[highest_zoneidx])
3726 if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
3730 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3731 * when checking the min watermark. The min watermark is the
3732 * point where boosting is ignored so that kswapd is woken up
3733 * when below the low watermark.
3735 if (unlikely(!order && (gfp_mask & __GFP_ATOMIC) && z->watermark_boost
3736 && ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) {
3737 mark = z->_watermark[WMARK_MIN];
3738 return __zone_watermark_ok(z, order, mark, highest_zoneidx,
3739 alloc_flags, free_pages);
3745 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
3746 unsigned long mark, int highest_zoneidx)
3748 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3750 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
3751 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
3753 return __zone_watermark_ok(z, order, mark, highest_zoneidx, 0,
3758 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3760 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3761 node_reclaim_distance;
3763 #else /* CONFIG_NUMA */
3764 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3768 #endif /* CONFIG_NUMA */
3771 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3772 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3773 * premature use of a lower zone may cause lowmem pressure problems that
3774 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3775 * probably too small. It only makes sense to spread allocations to avoid
3776 * fragmentation between the Normal and DMA32 zones.
3778 static inline unsigned int
3779 alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
3781 unsigned int alloc_flags;
3784 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3787 alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM);
3789 #ifdef CONFIG_ZONE_DMA32
3793 if (zone_idx(zone) != ZONE_NORMAL)
3797 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3798 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3799 * on UMA that if Normal is populated then so is DMA32.
3801 BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1);
3802 if (nr_online_nodes > 1 && !populated_zone(--zone))
3805 alloc_flags |= ALLOC_NOFRAGMENT;
3806 #endif /* CONFIG_ZONE_DMA32 */
3810 static inline unsigned int current_alloc_flags(gfp_t gfp_mask,
3811 unsigned int alloc_flags)
3814 unsigned int pflags = current->flags;
3816 if (!(pflags & PF_MEMALLOC_NOCMA) &&
3817 gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3818 alloc_flags |= ALLOC_CMA;
3825 * get_page_from_freelist goes through the zonelist trying to allocate
3828 static struct page *
3829 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
3830 const struct alloc_context *ac)
3834 struct pglist_data *last_pgdat_dirty_limit = NULL;
3839 * Scan zonelist, looking for a zone with enough free.
3840 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3842 no_fallback = alloc_flags & ALLOC_NOFRAGMENT;
3843 z = ac->preferred_zoneref;
3844 for_next_zone_zonelist_nodemask(zone, z, ac->highest_zoneidx,
3849 if (cpusets_enabled() &&
3850 (alloc_flags & ALLOC_CPUSET) &&
3851 !__cpuset_zone_allowed(zone, gfp_mask))
3854 * When allocating a page cache page for writing, we
3855 * want to get it from a node that is within its dirty
3856 * limit, such that no single node holds more than its
3857 * proportional share of globally allowed dirty pages.
3858 * The dirty limits take into account the node's
3859 * lowmem reserves and high watermark so that kswapd
3860 * should be able to balance it without having to
3861 * write pages from its LRU list.
3863 * XXX: For now, allow allocations to potentially
3864 * exceed the per-node dirty limit in the slowpath
3865 * (spread_dirty_pages unset) before going into reclaim,
3866 * which is important when on a NUMA setup the allowed
3867 * nodes are together not big enough to reach the
3868 * global limit. The proper fix for these situations
3869 * will require awareness of nodes in the
3870 * dirty-throttling and the flusher threads.
3872 if (ac->spread_dirty_pages) {
3873 if (last_pgdat_dirty_limit == zone->zone_pgdat)
3876 if (!node_dirty_ok(zone->zone_pgdat)) {
3877 last_pgdat_dirty_limit = zone->zone_pgdat;
3882 if (no_fallback && nr_online_nodes > 1 &&
3883 zone != ac->preferred_zoneref->zone) {
3887 * If moving to a remote node, retry but allow
3888 * fragmenting fallbacks. Locality is more important
3889 * than fragmentation avoidance.
3891 local_nid = zone_to_nid(ac->preferred_zoneref->zone);
3892 if (zone_to_nid(zone) != local_nid) {
3893 alloc_flags &= ~ALLOC_NOFRAGMENT;
3898 mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
3899 if (!zone_watermark_fast(zone, order, mark,
3900 ac->highest_zoneidx, alloc_flags,
3904 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3906 * Watermark failed for this zone, but see if we can
3907 * grow this zone if it contains deferred pages.
3909 if (static_branch_unlikely(&deferred_pages)) {
3910 if (_deferred_grow_zone(zone, order))
3914 /* Checked here to keep the fast path fast */
3915 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
3916 if (alloc_flags & ALLOC_NO_WATERMARKS)
3919 if (node_reclaim_mode == 0 ||
3920 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
3923 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
3925 case NODE_RECLAIM_NOSCAN:
3928 case NODE_RECLAIM_FULL:
3929 /* scanned but unreclaimable */
3932 /* did we reclaim enough */
3933 if (zone_watermark_ok(zone, order, mark,
3934 ac->highest_zoneidx, alloc_flags))
3942 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
3943 gfp_mask, alloc_flags, ac->migratetype);
3945 prep_new_page(page, order, gfp_mask, alloc_flags);
3948 * If this is a high-order atomic allocation then check
3949 * if the pageblock should be reserved for the future
3951 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3952 reserve_highatomic_pageblock(page, zone, order);
3956 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3957 /* Try again if zone has deferred pages */
3958 if (static_branch_unlikely(&deferred_pages)) {
3959 if (_deferred_grow_zone(zone, order))
3967 * It's possible on a UMA machine to get through all zones that are
3968 * fragmented. If avoiding fragmentation, reset and try again.
3971 alloc_flags &= ~ALLOC_NOFRAGMENT;
3978 static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
3980 unsigned int filter = SHOW_MEM_FILTER_NODES;
3983 * This documents exceptions given to allocations in certain
3984 * contexts that are allowed to allocate outside current's set
3987 if (!(gfp_mask & __GFP_NOMEMALLOC))
3988 if (tsk_is_oom_victim(current) ||
3989 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3990 filter &= ~SHOW_MEM_FILTER_NODES;
3991 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3992 filter &= ~SHOW_MEM_FILTER_NODES;
3994 show_mem(filter, nodemask);
3997 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
3999 struct va_format vaf;
4001 static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1);
4003 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
4006 va_start(args, fmt);
4009 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
4010 current->comm, &vaf, gfp_mask, &gfp_mask,
4011 nodemask_pr_args(nodemask));
4014 cpuset_print_current_mems_allowed();
4017 warn_alloc_show_mem(gfp_mask, nodemask);
4020 static inline struct page *
4021 __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
4022 unsigned int alloc_flags,
4023 const struct alloc_context *ac)
4027 page = get_page_from_freelist(gfp_mask, order,
4028 alloc_flags|ALLOC_CPUSET, ac);
4030 * fallback to ignore cpuset restriction if our nodes
4034 page = get_page_from_freelist(gfp_mask, order,
4040 static inline struct page *
4041 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
4042 const struct alloc_context *ac, unsigned long *did_some_progress)
4044 struct oom_control oc = {
4045 .zonelist = ac->zonelist,
4046 .nodemask = ac->nodemask,
4048 .gfp_mask = gfp_mask,
4053 *did_some_progress = 0;
4056 * Acquire the oom lock. If that fails, somebody else is
4057 * making progress for us.
4059 if (!mutex_trylock(&oom_lock)) {
4060 *did_some_progress = 1;
4061 schedule_timeout_uninterruptible(1);
4066 * Go through the zonelist yet one more time, keep very high watermark
4067 * here, this is only to catch a parallel oom killing, we must fail if
4068 * we're still under heavy pressure. But make sure that this reclaim
4069 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
4070 * allocation which will never fail due to oom_lock already held.
4072 page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
4073 ~__GFP_DIRECT_RECLAIM, order,
4074 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
4078 /* Coredumps can quickly deplete all memory reserves */
4079 if (current->flags & PF_DUMPCORE)
4081 /* The OOM killer will not help higher order allocs */
4082 if (order > PAGE_ALLOC_COSTLY_ORDER)
4085 * We have already exhausted all our reclaim opportunities without any
4086 * success so it is time to admit defeat. We will skip the OOM killer
4087 * because it is very likely that the caller has a more reasonable
4088 * fallback than shooting a random task.
4090 * The OOM killer may not free memory on a specific node.
4092 if (gfp_mask & (__GFP_RETRY_MAYFAIL | __GFP_THISNODE))
4094 /* The OOM killer does not needlessly kill tasks for lowmem */
4095 if (ac->highest_zoneidx < ZONE_NORMAL)
4097 if (pm_suspended_storage())
4100 * XXX: GFP_NOFS allocations should rather fail than rely on
4101 * other request to make a forward progress.
4102 * We are in an unfortunate situation where out_of_memory cannot
4103 * do much for this context but let's try it to at least get
4104 * access to memory reserved if the current task is killed (see
4105 * out_of_memory). Once filesystems are ready to handle allocation
4106 * failures more gracefully we should just bail out here.
4109 /* Exhausted what can be done so it's blame time */
4110 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
4111 *did_some_progress = 1;
4114 * Help non-failing allocations by giving them access to memory
4117 if (gfp_mask & __GFP_NOFAIL)
4118 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
4119 ALLOC_NO_WATERMARKS, ac);
4122 mutex_unlock(&oom_lock);
4127 * Maximum number of compaction retries wit a progress before OOM
4128 * killer is consider as the only way to move forward.
4130 #define MAX_COMPACT_RETRIES 16
4132 #ifdef CONFIG_COMPACTION
4133 /* Try memory compaction for high-order allocations before reclaim */
4134 static struct page *
4135 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4136 unsigned int alloc_flags, const struct alloc_context *ac,
4137 enum compact_priority prio, enum compact_result *compact_result)
4139 struct page *page = NULL;
4140 unsigned long pflags;
4141 unsigned int noreclaim_flag;
4146 psi_memstall_enter(&pflags);
4147 noreclaim_flag = memalloc_noreclaim_save();
4149 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
4152 memalloc_noreclaim_restore(noreclaim_flag);
4153 psi_memstall_leave(&pflags);
4156 * At least in one zone compaction wasn't deferred or skipped, so let's
4157 * count a compaction stall
4159 count_vm_event(COMPACTSTALL);
4161 /* Prep a captured page if available */
4163 prep_new_page(page, order, gfp_mask, alloc_flags);
4165 /* Try get a page from the freelist if available */
4167 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4170 struct zone *zone = page_zone(page);
4172 zone->compact_blockskip_flush = false;
4173 compaction_defer_reset(zone, order, true);
4174 count_vm_event(COMPACTSUCCESS);
4179 * It's bad if compaction run occurs and fails. The most likely reason
4180 * is that pages exist, but not enough to satisfy watermarks.
4182 count_vm_event(COMPACTFAIL);
4190 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
4191 enum compact_result compact_result,
4192 enum compact_priority *compact_priority,
4193 int *compaction_retries)
4195 int max_retries = MAX_COMPACT_RETRIES;
4198 int retries = *compaction_retries;
4199 enum compact_priority priority = *compact_priority;
4204 if (compaction_made_progress(compact_result))
4205 (*compaction_retries)++;
4208 * compaction considers all the zone as desperately out of memory
4209 * so it doesn't really make much sense to retry except when the
4210 * failure could be caused by insufficient priority
4212 if (compaction_failed(compact_result))
4213 goto check_priority;
4216 * compaction was skipped because there are not enough order-0 pages
4217 * to work with, so we retry only if it looks like reclaim can help.
4219 if (compaction_needs_reclaim(compact_result)) {
4220 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
4225 * make sure the compaction wasn't deferred or didn't bail out early
4226 * due to locks contention before we declare that we should give up.
4227 * But the next retry should use a higher priority if allowed, so
4228 * we don't just keep bailing out endlessly.
4230 if (compaction_withdrawn(compact_result)) {
4231 goto check_priority;
4235 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4236 * costly ones because they are de facto nofail and invoke OOM
4237 * killer to move on while costly can fail and users are ready
4238 * to cope with that. 1/4 retries is rather arbitrary but we
4239 * would need much more detailed feedback from compaction to
4240 * make a better decision.
4242 if (order > PAGE_ALLOC_COSTLY_ORDER)
4244 if (*compaction_retries <= max_retries) {
4250 * Make sure there are attempts at the highest priority if we exhausted
4251 * all retries or failed at the lower priorities.
4254 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
4255 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
4257 if (*compact_priority > min_priority) {
4258 (*compact_priority)--;
4259 *compaction_retries = 0;
4263 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
4267 static inline struct page *
4268 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
4269 unsigned int alloc_flags, const struct alloc_context *ac,
4270 enum compact_priority prio, enum compact_result *compact_result)
4272 *compact_result = COMPACT_SKIPPED;
4277 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
4278 enum compact_result compact_result,
4279 enum compact_priority *compact_priority,
4280 int *compaction_retries)
4285 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
4289 * There are setups with compaction disabled which would prefer to loop
4290 * inside the allocator rather than hit the oom killer prematurely.
4291 * Let's give them a good hope and keep retrying while the order-0
4292 * watermarks are OK.
4294 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
4295 ac->highest_zoneidx, ac->nodemask) {
4296 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
4297 ac->highest_zoneidx, alloc_flags))
4302 #endif /* CONFIG_COMPACTION */
4304 #ifdef CONFIG_LOCKDEP
4305 static struct lockdep_map __fs_reclaim_map =
4306 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
4308 static bool __need_reclaim(gfp_t gfp_mask)
4310 /* no reclaim without waiting on it */
4311 if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
4314 /* this guy won't enter reclaim */
4315 if (current->flags & PF_MEMALLOC)
4318 if (gfp_mask & __GFP_NOLOCKDEP)
4324 void __fs_reclaim_acquire(void)
4326 lock_map_acquire(&__fs_reclaim_map);
4329 void __fs_reclaim_release(void)
4331 lock_map_release(&__fs_reclaim_map);
4334 void fs_reclaim_acquire(gfp_t gfp_mask)
4336 gfp_mask = current_gfp_context(gfp_mask);
4338 if (__need_reclaim(gfp_mask)) {
4339 if (gfp_mask & __GFP_FS)
4340 __fs_reclaim_acquire();
4342 #ifdef CONFIG_MMU_NOTIFIER
4343 lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
4344 lock_map_release(&__mmu_notifier_invalidate_range_start_map);
4349 EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
4351 void fs_reclaim_release(gfp_t gfp_mask)
4353 gfp_mask = current_gfp_context(gfp_mask);
4355 if (__need_reclaim(gfp_mask)) {
4356 if (gfp_mask & __GFP_FS)
4357 __fs_reclaim_release();
4360 EXPORT_SYMBOL_GPL(fs_reclaim_release);
4363 /* Perform direct synchronous page reclaim */
4364 static unsigned long
4365 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
4366 const struct alloc_context *ac)
4368 unsigned int noreclaim_flag;
4369 unsigned long pflags, progress;
4373 /* We now go into synchronous reclaim */
4374 cpuset_memory_pressure_bump();
4375 psi_memstall_enter(&pflags);
4376 fs_reclaim_acquire(gfp_mask);
4377 noreclaim_flag = memalloc_noreclaim_save();
4379 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
4382 memalloc_noreclaim_restore(noreclaim_flag);
4383 fs_reclaim_release(gfp_mask);
4384 psi_memstall_leave(&pflags);
4391 /* The really slow allocator path where we enter direct reclaim */
4392 static inline struct page *
4393 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
4394 unsigned int alloc_flags, const struct alloc_context *ac,
4395 unsigned long *did_some_progress)
4397 struct page *page = NULL;
4398 bool drained = false;
4400 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
4401 if (unlikely(!(*did_some_progress)))
4405 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4408 * If an allocation failed after direct reclaim, it could be because
4409 * pages are pinned on the per-cpu lists or in high alloc reserves.
4410 * Shrink them and try again
4412 if (!page && !drained) {
4413 unreserve_highatomic_pageblock(ac, false);
4414 drain_all_pages(NULL);
4422 static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
4423 const struct alloc_context *ac)
4427 pg_data_t *last_pgdat = NULL;
4428 enum zone_type highest_zoneidx = ac->highest_zoneidx;
4430 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
4432 if (last_pgdat != zone->zone_pgdat)
4433 wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
4434 last_pgdat = zone->zone_pgdat;
4438 static inline unsigned int
4439 gfp_to_alloc_flags(gfp_t gfp_mask)
4441 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
4444 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4445 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4446 * to save two branches.
4448 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
4449 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD);
4452 * The caller may dip into page reserves a bit more if the caller
4453 * cannot run direct reclaim, or if the caller has realtime scheduling
4454 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4455 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4457 alloc_flags |= (__force int)
4458 (gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM));
4460 if (gfp_mask & __GFP_ATOMIC) {
4462 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4463 * if it can't schedule.
4465 if (!(gfp_mask & __GFP_NOMEMALLOC))
4466 alloc_flags |= ALLOC_HARDER;
4468 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4469 * comment for __cpuset_node_allowed().
4471 alloc_flags &= ~ALLOC_CPUSET;
4472 } else if (unlikely(rt_task(current)) && !in_interrupt())
4473 alloc_flags |= ALLOC_HARDER;
4475 alloc_flags = current_alloc_flags(gfp_mask, alloc_flags);
4480 static bool oom_reserves_allowed(struct task_struct *tsk)
4482 if (!tsk_is_oom_victim(tsk))
4486 * !MMU doesn't have oom reaper so give access to memory reserves
4487 * only to the thread with TIF_MEMDIE set
4489 if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
4496 * Distinguish requests which really need access to full memory
4497 * reserves from oom victims which can live with a portion of it
4499 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
4501 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
4503 if (gfp_mask & __GFP_MEMALLOC)
4504 return ALLOC_NO_WATERMARKS;
4505 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
4506 return ALLOC_NO_WATERMARKS;
4507 if (!in_interrupt()) {
4508 if (current->flags & PF_MEMALLOC)
4509 return ALLOC_NO_WATERMARKS;
4510 else if (oom_reserves_allowed(current))
4517 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
4519 return !!__gfp_pfmemalloc_flags(gfp_mask);
4523 * Checks whether it makes sense to retry the reclaim to make a forward progress
4524 * for the given allocation request.
4526 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4527 * without success, or when we couldn't even meet the watermark if we
4528 * reclaimed all remaining pages on the LRU lists.
4530 * Returns true if a retry is viable or false to enter the oom path.
4533 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
4534 struct alloc_context *ac, int alloc_flags,
4535 bool did_some_progress, int *no_progress_loops)
4542 * Costly allocations might have made a progress but this doesn't mean
4543 * their order will become available due to high fragmentation so
4544 * always increment the no progress counter for them
4546 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
4547 *no_progress_loops = 0;
4549 (*no_progress_loops)++;
4552 * Make sure we converge to OOM if we cannot make any progress
4553 * several times in the row.
4555 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
4556 /* Before OOM, exhaust highatomic_reserve */
4557 return unreserve_highatomic_pageblock(ac, true);
4561 * Keep reclaiming pages while there is a chance this will lead
4562 * somewhere. If none of the target zones can satisfy our allocation
4563 * request even if all reclaimable pages are considered then we are
4564 * screwed and have to go OOM.
4566 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
4567 ac->highest_zoneidx, ac->nodemask) {
4568 unsigned long available;
4569 unsigned long reclaimable;
4570 unsigned long min_wmark = min_wmark_pages(zone);
4573 available = reclaimable = zone_reclaimable_pages(zone);
4574 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
4577 * Would the allocation succeed if we reclaimed all
4578 * reclaimable pages?
4580 wmark = __zone_watermark_ok(zone, order, min_wmark,
4581 ac->highest_zoneidx, alloc_flags, available);
4582 trace_reclaim_retry_zone(z, order, reclaimable,
4583 available, min_wmark, *no_progress_loops, wmark);
4586 * If we didn't make any progress and have a lot of
4587 * dirty + writeback pages then we should wait for
4588 * an IO to complete to slow down the reclaim and
4589 * prevent from pre mature OOM
4591 if (!did_some_progress) {
4592 unsigned long write_pending;
4594 write_pending = zone_page_state_snapshot(zone,
4595 NR_ZONE_WRITE_PENDING);
4597 if (2 * write_pending > reclaimable) {
4598 congestion_wait(BLK_RW_ASYNC, HZ/10);
4610 * Memory allocation/reclaim might be called from a WQ context and the
4611 * current implementation of the WQ concurrency control doesn't
4612 * recognize that a particular WQ is congested if the worker thread is
4613 * looping without ever sleeping. Therefore we have to do a short sleep
4614 * here rather than calling cond_resched().
4616 if (current->flags & PF_WQ_WORKER)
4617 schedule_timeout_uninterruptible(1);
4624 check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
4627 * It's possible that cpuset's mems_allowed and the nodemask from
4628 * mempolicy don't intersect. This should be normally dealt with by
4629 * policy_nodemask(), but it's possible to race with cpuset update in
4630 * such a way the check therein was true, and then it became false
4631 * before we got our cpuset_mems_cookie here.
4632 * This assumes that for all allocations, ac->nodemask can come only
4633 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4634 * when it does not intersect with the cpuset restrictions) or the
4635 * caller can deal with a violated nodemask.
4637 if (cpusets_enabled() && ac->nodemask &&
4638 !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
4639 ac->nodemask = NULL;
4644 * When updating a task's mems_allowed or mempolicy nodemask, it is
4645 * possible to race with parallel threads in such a way that our
4646 * allocation can fail while the mask is being updated. If we are about
4647 * to fail, check if the cpuset changed during allocation and if so,
4650 if (read_mems_allowed_retry(cpuset_mems_cookie))
4656 static inline struct page *
4657 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
4658 struct alloc_context *ac)
4660 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
4661 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
4662 struct page *page = NULL;
4663 unsigned int alloc_flags;
4664 unsigned long did_some_progress;
4665 enum compact_priority compact_priority;
4666 enum compact_result compact_result;
4667 int compaction_retries;
4668 int no_progress_loops;
4669 unsigned int cpuset_mems_cookie;
4673 * We also sanity check to catch abuse of atomic reserves being used by
4674 * callers that are not in atomic context.
4676 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
4677 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
4678 gfp_mask &= ~__GFP_ATOMIC;
4681 compaction_retries = 0;
4682 no_progress_loops = 0;
4683 compact_priority = DEF_COMPACT_PRIORITY;
4684 cpuset_mems_cookie = read_mems_allowed_begin();
4687 * The fast path uses conservative alloc_flags to succeed only until
4688 * kswapd needs to be woken up, and to avoid the cost of setting up
4689 * alloc_flags precisely. So we do that now.
4691 alloc_flags = gfp_to_alloc_flags(gfp_mask);
4694 * We need to recalculate the starting point for the zonelist iterator
4695 * because we might have used different nodemask in the fast path, or
4696 * there was a cpuset modification and we are retrying - otherwise we
4697 * could end up iterating over non-eligible zones endlessly.
4699 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4700 ac->highest_zoneidx, ac->nodemask);
4701 if (!ac->preferred_zoneref->zone)
4704 if (alloc_flags & ALLOC_KSWAPD)
4705 wake_all_kswapds(order, gfp_mask, ac);
4708 * The adjusted alloc_flags might result in immediate success, so try
4711 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4716 * For costly allocations, try direct compaction first, as it's likely
4717 * that we have enough base pages and don't need to reclaim. For non-
4718 * movable high-order allocations, do that as well, as compaction will
4719 * try prevent permanent fragmentation by migrating from blocks of the
4721 * Don't try this for allocations that are allowed to ignore
4722 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4724 if (can_direct_reclaim &&
4726 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
4727 && !gfp_pfmemalloc_allowed(gfp_mask)) {
4728 page = __alloc_pages_direct_compact(gfp_mask, order,
4730 INIT_COMPACT_PRIORITY,
4736 * Checks for costly allocations with __GFP_NORETRY, which
4737 * includes some THP page fault allocations
4739 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
4741 * If allocating entire pageblock(s) and compaction
4742 * failed because all zones are below low watermarks
4743 * or is prohibited because it recently failed at this
4744 * order, fail immediately unless the allocator has
4745 * requested compaction and reclaim retry.
4748 * - potentially very expensive because zones are far
4749 * below their low watermarks or this is part of very
4750 * bursty high order allocations,
4751 * - not guaranteed to help because isolate_freepages()
4752 * may not iterate over freed pages as part of its
4754 * - unlikely to make entire pageblocks free on its
4757 if (compact_result == COMPACT_SKIPPED ||
4758 compact_result == COMPACT_DEFERRED)
4762 * Looks like reclaim/compaction is worth trying, but
4763 * sync compaction could be very expensive, so keep
4764 * using async compaction.
4766 compact_priority = INIT_COMPACT_PRIORITY;
4771 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4772 if (alloc_flags & ALLOC_KSWAPD)
4773 wake_all_kswapds(order, gfp_mask, ac);
4775 reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
4777 alloc_flags = current_alloc_flags(gfp_mask, reserve_flags);
4780 * Reset the nodemask and zonelist iterators if memory policies can be
4781 * ignored. These allocations are high priority and system rather than
4784 if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
4785 ac->nodemask = NULL;
4786 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4787 ac->highest_zoneidx, ac->nodemask);
4790 /* Attempt with potentially adjusted zonelist and alloc_flags */
4791 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4795 /* Caller is not willing to reclaim, we can't balance anything */
4796 if (!can_direct_reclaim)
4799 /* Avoid recursion of direct reclaim */
4800 if (current->flags & PF_MEMALLOC)
4803 /* Try direct reclaim and then allocating */
4804 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
4805 &did_some_progress);
4809 /* Try direct compaction and then allocating */
4810 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
4811 compact_priority, &compact_result);
4815 /* Do not loop if specifically requested */
4816 if (gfp_mask & __GFP_NORETRY)
4820 * Do not retry costly high order allocations unless they are
4821 * __GFP_RETRY_MAYFAIL
4823 if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
4826 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
4827 did_some_progress > 0, &no_progress_loops))
4831 * It doesn't make any sense to retry for the compaction if the order-0
4832 * reclaim is not able to make any progress because the current
4833 * implementation of the compaction depends on the sufficient amount
4834 * of free memory (see __compaction_suitable)
4836 if (did_some_progress > 0 &&
4837 should_compact_retry(ac, order, alloc_flags,
4838 compact_result, &compact_priority,
4839 &compaction_retries))
4843 /* Deal with possible cpuset update races before we start OOM killing */
4844 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4847 /* Reclaim has failed us, start killing things */
4848 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
4852 /* Avoid allocations with no watermarks from looping endlessly */
4853 if (tsk_is_oom_victim(current) &&
4854 (alloc_flags & ALLOC_OOM ||
4855 (gfp_mask & __GFP_NOMEMALLOC)))
4858 /* Retry as long as the OOM killer is making progress */
4859 if (did_some_progress) {
4860 no_progress_loops = 0;
4865 /* Deal with possible cpuset update races before we fail */
4866 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4870 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4873 if (gfp_mask & __GFP_NOFAIL) {
4875 * All existing users of the __GFP_NOFAIL are blockable, so warn
4876 * of any new users that actually require GFP_NOWAIT
4878 if (WARN_ON_ONCE(!can_direct_reclaim))
4882 * PF_MEMALLOC request from this context is rather bizarre
4883 * because we cannot reclaim anything and only can loop waiting
4884 * for somebody to do a work for us
4886 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
4889 * non failing costly orders are a hard requirement which we
4890 * are not prepared for much so let's warn about these users
4891 * so that we can identify them and convert them to something
4894 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
4897 * Help non-failing allocations by giving them access to memory
4898 * reserves but do not use ALLOC_NO_WATERMARKS because this
4899 * could deplete whole memory reserves which would just make
4900 * the situation worse
4902 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
4910 warn_alloc(gfp_mask, ac->nodemask,
4911 "page allocation failure: order:%u", order);
4916 static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
4917 int preferred_nid, nodemask_t *nodemask,
4918 struct alloc_context *ac, gfp_t *alloc_mask,
4919 unsigned int *alloc_flags)
4921 ac->highest_zoneidx = gfp_zone(gfp_mask);
4922 ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
4923 ac->nodemask = nodemask;
4924 ac->migratetype = gfp_migratetype(gfp_mask);
4926 if (cpusets_enabled()) {
4927 *alloc_mask |= __GFP_HARDWALL;
4929 * When we are in the interrupt context, it is irrelevant
4930 * to the current task context. It means that any node ok.
4932 if (!in_interrupt() && !ac->nodemask)
4933 ac->nodemask = &cpuset_current_mems_allowed;
4935 *alloc_flags |= ALLOC_CPUSET;
4938 fs_reclaim_acquire(gfp_mask);
4939 fs_reclaim_release(gfp_mask);
4941 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
4943 if (should_fail_alloc_page(gfp_mask, order))
4946 *alloc_flags = current_alloc_flags(gfp_mask, *alloc_flags);
4948 /* Dirty zone balancing only done in the fast path */
4949 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
4952 * The preferred zone is used for statistics but crucially it is
4953 * also used as the starting point for the zonelist iterator. It
4954 * may get reset for allocations that ignore memory policies.
4956 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4957 ac->highest_zoneidx, ac->nodemask);
4963 * This is the 'heart' of the zoned buddy allocator.
4966 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
4967 nodemask_t *nodemask)
4970 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4971 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
4972 struct alloc_context ac = { };
4975 * There are several places where we assume that the order value is sane
4976 * so bail out early if the request is out of bound.
4978 if (unlikely(order >= MAX_ORDER)) {
4979 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4983 gfp_mask &= gfp_allowed_mask;
4984 alloc_mask = gfp_mask;
4985 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
4989 * Forbid the first pass from falling back to types that fragment
4990 * memory until all local zones are considered.
4992 alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp_mask);
4994 /* First allocation attempt */
4995 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
5000 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
5001 * resp. GFP_NOIO which has to be inherited for all allocation requests
5002 * from a particular context which has been marked by
5003 * memalloc_no{fs,io}_{save,restore}.
5005 alloc_mask = current_gfp_context(gfp_mask);
5006 ac.spread_dirty_pages = false;
5009 * Restore the original nodemask if it was potentially replaced with
5010 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
5012 ac.nodemask = nodemask;
5014 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
5017 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
5018 unlikely(__memcg_kmem_charge_page(page, gfp_mask, order) != 0)) {
5019 __free_pages(page, order);
5023 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
5027 EXPORT_SYMBOL(__alloc_pages_nodemask);
5030 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
5031 * address cannot represent highmem pages. Use alloc_pages and then kmap if
5032 * you need to access high mem.
5034 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
5038 page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order);
5041 return (unsigned long) page_address(page);
5043 EXPORT_SYMBOL(__get_free_pages);
5045 unsigned long get_zeroed_page(gfp_t gfp_mask)
5047 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
5049 EXPORT_SYMBOL(get_zeroed_page);
5051 static inline void free_the_page(struct page *page, unsigned int order)
5053 if (order == 0) /* Via pcp? */
5054 free_unref_page(page);
5056 __free_pages_ok(page, order, FPI_NONE);
5060 * __free_pages - Free pages allocated with alloc_pages().
5061 * @page: The page pointer returned from alloc_pages().
5062 * @order: The order of the allocation.
5064 * This function can free multi-page allocations that are not compound
5065 * pages. It does not check that the @order passed in matches that of
5066 * the allocation, so it is easy to leak memory. Freeing more memory
5067 * than was allocated will probably emit a warning.
5069 * If the last reference to this page is speculative, it will be released
5070 * by put_page() which only frees the first page of a non-compound
5071 * allocation. To prevent the remaining pages from being leaked, we free
5072 * the subsequent pages here. If you want to use the page's reference
5073 * count to decide when to free the allocation, you should allocate a
5074 * compound page, and use put_page() instead of __free_pages().
5076 * Context: May be called in interrupt context or while holding a normal
5077 * spinlock, but not in NMI context or while holding a raw spinlock.
5079 void __free_pages(struct page *page, unsigned int order)
5081 if (put_page_testzero(page))
5082 free_the_page(page, order);
5083 else if (!PageHead(page))
5085 free_the_page(page + (1 << order), order);
5087 EXPORT_SYMBOL(__free_pages);
5089 void free_pages(unsigned long addr, unsigned int order)
5092 VM_BUG_ON(!virt_addr_valid((void *)addr));
5093 __free_pages(virt_to_page((void *)addr), order);
5097 EXPORT_SYMBOL(free_pages);
5101 * An arbitrary-length arbitrary-offset area of memory which resides
5102 * within a 0 or higher order page. Multiple fragments within that page
5103 * are individually refcounted, in the page's reference counter.
5105 * The page_frag functions below provide a simple allocation framework for
5106 * page fragments. This is used by the network stack and network device
5107 * drivers to provide a backing region of memory for use as either an
5108 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
5110 static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
5113 struct page *page = NULL;
5114 gfp_t gfp = gfp_mask;
5116 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5117 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
5119 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
5120 PAGE_FRAG_CACHE_MAX_ORDER);
5121 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
5123 if (unlikely(!page))
5124 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
5126 nc->va = page ? page_address(page) : NULL;
5131 void __page_frag_cache_drain(struct page *page, unsigned int count)
5133 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
5135 if (page_ref_sub_and_test(page, count))
5136 free_the_page(page, compound_order(page));
5138 EXPORT_SYMBOL(__page_frag_cache_drain);
5140 void *page_frag_alloc_align(struct page_frag_cache *nc,
5141 unsigned int fragsz, gfp_t gfp_mask,
5142 unsigned int align_mask)
5144 unsigned int size = PAGE_SIZE;
5148 if (unlikely(!nc->va)) {
5150 page = __page_frag_cache_refill(nc, gfp_mask);
5154 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5155 /* if size can vary use size else just use PAGE_SIZE */
5158 /* Even if we own the page, we do not use atomic_set().
5159 * This would break get_page_unless_zero() users.
5161 page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE);
5163 /* reset page count bias and offset to start of new frag */
5164 nc->pfmemalloc = page_is_pfmemalloc(page);
5165 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
5169 offset = nc->offset - fragsz;
5170 if (unlikely(offset < 0)) {
5171 page = virt_to_page(nc->va);
5173 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
5176 if (unlikely(nc->pfmemalloc)) {
5177 free_the_page(page, compound_order(page));
5181 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5182 /* if size can vary use size else just use PAGE_SIZE */
5185 /* OK, page count is 0, we can safely set it */
5186 set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1);
5188 /* reset page count bias and offset to start of new frag */
5189 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
5190 offset = size - fragsz;
5194 offset &= align_mask;
5195 nc->offset = offset;
5197 return nc->va + offset;
5199 EXPORT_SYMBOL(page_frag_alloc_align);
5202 * Frees a page fragment allocated out of either a compound or order 0 page.
5204 void page_frag_free(void *addr)
5206 struct page *page = virt_to_head_page(addr);
5208 if (unlikely(put_page_testzero(page)))
5209 free_the_page(page, compound_order(page));
5211 EXPORT_SYMBOL(page_frag_free);
5213 static void *make_alloc_exact(unsigned long addr, unsigned int order,
5217 unsigned long alloc_end = addr + (PAGE_SIZE << order);
5218 unsigned long used = addr + PAGE_ALIGN(size);
5220 split_page(virt_to_page((void *)addr), order);
5221 while (used < alloc_end) {
5226 return (void *)addr;
5230 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5231 * @size: the number of bytes to allocate
5232 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5234 * This function is similar to alloc_pages(), except that it allocates the
5235 * minimum number of pages to satisfy the request. alloc_pages() can only
5236 * allocate memory in power-of-two pages.
5238 * This function is also limited by MAX_ORDER.
5240 * Memory allocated by this function must be released by free_pages_exact().
5242 * Return: pointer to the allocated area or %NULL in case of error.
5244 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
5246 unsigned int order = get_order(size);
5249 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5250 gfp_mask &= ~__GFP_COMP;
5252 addr = __get_free_pages(gfp_mask, order);
5253 return make_alloc_exact(addr, order, size);
5255 EXPORT_SYMBOL(alloc_pages_exact);
5258 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5260 * @nid: the preferred node ID where memory should be allocated
5261 * @size: the number of bytes to allocate
5262 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5264 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5267 * Return: pointer to the allocated area or %NULL in case of error.
5269 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
5271 unsigned int order = get_order(size);
5274 if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
5275 gfp_mask &= ~__GFP_COMP;
5277 p = alloc_pages_node(nid, gfp_mask, order);
5280 return make_alloc_exact((unsigned long)page_address(p), order, size);
5284 * free_pages_exact - release memory allocated via alloc_pages_exact()
5285 * @virt: the value returned by alloc_pages_exact.
5286 * @size: size of allocation, same value as passed to alloc_pages_exact().
5288 * Release the memory allocated by a previous call to alloc_pages_exact.
5290 void free_pages_exact(void *virt, size_t size)
5292 unsigned long addr = (unsigned long)virt;
5293 unsigned long end = addr + PAGE_ALIGN(size);
5295 while (addr < end) {
5300 EXPORT_SYMBOL(free_pages_exact);
5303 * nr_free_zone_pages - count number of pages beyond high watermark
5304 * @offset: The zone index of the highest zone
5306 * nr_free_zone_pages() counts the number of pages which are beyond the
5307 * high watermark within all zones at or below a given zone index. For each
5308 * zone, the number of pages is calculated as:
5310 * nr_free_zone_pages = managed_pages - high_pages
5312 * Return: number of pages beyond high watermark.
5314 static unsigned long nr_free_zone_pages(int offset)
5319 /* Just pick one node, since fallback list is circular */
5320 unsigned long sum = 0;
5322 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
5324 for_each_zone_zonelist(zone, z, zonelist, offset) {
5325 unsigned long size = zone_managed_pages(zone);
5326 unsigned long high = high_wmark_pages(zone);
5335 * nr_free_buffer_pages - count number of pages beyond high watermark
5337 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5338 * watermark within ZONE_DMA and ZONE_NORMAL.
5340 * Return: number of pages beyond high watermark within ZONE_DMA and
5343 unsigned long nr_free_buffer_pages(void)
5345 return nr_free_zone_pages(gfp_zone(GFP_USER));
5347 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
5349 static inline void show_node(struct zone *zone)
5351 if (IS_ENABLED(CONFIG_NUMA))
5352 printk("Node %d ", zone_to_nid(zone));
5355 long si_mem_available(void)
5358 unsigned long pagecache;
5359 unsigned long wmark_low = 0;
5360 unsigned long pages[NR_LRU_LISTS];
5361 unsigned long reclaimable;
5365 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
5366 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
5369 wmark_low += low_wmark_pages(zone);
5372 * Estimate the amount of memory available for userspace allocations,
5373 * without causing swapping.
5375 available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
5378 * Not all the page cache can be freed, otherwise the system will
5379 * start swapping. Assume at least half of the page cache, or the
5380 * low watermark worth of cache, needs to stay.
5382 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
5383 pagecache -= min(pagecache / 2, wmark_low);
5384 available += pagecache;
5387 * Part of the reclaimable slab and other kernel memory consists of
5388 * items that are in use, and cannot be freed. Cap this estimate at the
5391 reclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) +
5392 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE);
5393 available += reclaimable - min(reclaimable / 2, wmark_low);
5399 EXPORT_SYMBOL_GPL(si_mem_available);
5401 void si_meminfo(struct sysinfo *val)
5403 val->totalram = totalram_pages();
5404 val->sharedram = global_node_page_state(NR_SHMEM);
5405 val->freeram = global_zone_page_state(NR_FREE_PAGES);
5406 val->bufferram = nr_blockdev_pages();
5407 val->totalhigh = totalhigh_pages();
5408 val->freehigh = nr_free_highpages();
5409 val->mem_unit = PAGE_SIZE;
5412 EXPORT_SYMBOL(si_meminfo);
5415 void si_meminfo_node(struct sysinfo *val, int nid)
5417 int zone_type; /* needs to be signed */
5418 unsigned long managed_pages = 0;
5419 unsigned long managed_highpages = 0;
5420 unsigned long free_highpages = 0;
5421 pg_data_t *pgdat = NODE_DATA(nid);
5423 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
5424 managed_pages += zone_managed_pages(&pgdat->node_zones[zone_type]);
5425 val->totalram = managed_pages;
5426 val->sharedram = node_page_state(pgdat, NR_SHMEM);
5427 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
5428 #ifdef CONFIG_HIGHMEM
5429 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
5430 struct zone *zone = &pgdat->node_zones[zone_type];
5432 if (is_highmem(zone)) {
5433 managed_highpages += zone_managed_pages(zone);
5434 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
5437 val->totalhigh = managed_highpages;
5438 val->freehigh = free_highpages;
5440 val->totalhigh = managed_highpages;
5441 val->freehigh = free_highpages;
5443 val->mem_unit = PAGE_SIZE;
5448 * Determine whether the node should be displayed or not, depending on whether
5449 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5451 static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
5453 if (!(flags & SHOW_MEM_FILTER_NODES))
5457 * no node mask - aka implicit memory numa policy. Do not bother with
5458 * the synchronization - read_mems_allowed_begin - because we do not
5459 * have to be precise here.
5462 nodemask = &cpuset_current_mems_allowed;
5464 return !node_isset(nid, *nodemask);
5467 #define K(x) ((x) << (PAGE_SHIFT-10))
5469 static void show_migration_types(unsigned char type)
5471 static const char types[MIGRATE_TYPES] = {
5472 [MIGRATE_UNMOVABLE] = 'U',
5473 [MIGRATE_MOVABLE] = 'M',
5474 [MIGRATE_RECLAIMABLE] = 'E',
5475 [MIGRATE_HIGHATOMIC] = 'H',
5477 [MIGRATE_CMA] = 'C',
5479 #ifdef CONFIG_MEMORY_ISOLATION
5480 [MIGRATE_ISOLATE] = 'I',
5483 char tmp[MIGRATE_TYPES + 1];
5487 for (i = 0; i < MIGRATE_TYPES; i++) {
5488 if (type & (1 << i))
5493 printk(KERN_CONT "(%s) ", tmp);
5497 * Show free area list (used inside shift_scroll-lock stuff)
5498 * We also calculate the percentage fragmentation. We do this by counting the
5499 * memory on each free list with the exception of the first item on the list.
5502 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5505 void show_free_areas(unsigned int filter, nodemask_t *nodemask)
5507 unsigned long free_pcp = 0;
5512 for_each_populated_zone(zone) {
5513 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5516 for_each_online_cpu(cpu)
5517 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
5520 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5521 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5522 " unevictable:%lu dirty:%lu writeback:%lu\n"
5523 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5524 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5525 " free:%lu free_pcp:%lu free_cma:%lu\n",
5526 global_node_page_state(NR_ACTIVE_ANON),
5527 global_node_page_state(NR_INACTIVE_ANON),
5528 global_node_page_state(NR_ISOLATED_ANON),
5529 global_node_page_state(NR_ACTIVE_FILE),
5530 global_node_page_state(NR_INACTIVE_FILE),
5531 global_node_page_state(NR_ISOLATED_FILE),
5532 global_node_page_state(NR_UNEVICTABLE),
5533 global_node_page_state(NR_FILE_DIRTY),
5534 global_node_page_state(NR_WRITEBACK),
5535 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B),
5536 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B),
5537 global_node_page_state(NR_FILE_MAPPED),
5538 global_node_page_state(NR_SHMEM),
5539 global_node_page_state(NR_PAGETABLE),
5540 global_zone_page_state(NR_BOUNCE),
5541 global_zone_page_state(NR_FREE_PAGES),
5543 global_zone_page_state(NR_FREE_CMA_PAGES));
5545 for_each_online_pgdat(pgdat) {
5546 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
5550 " active_anon:%lukB"
5551 " inactive_anon:%lukB"
5552 " active_file:%lukB"
5553 " inactive_file:%lukB"
5554 " unevictable:%lukB"
5555 " isolated(anon):%lukB"
5556 " isolated(file):%lukB"
5561 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5563 " shmem_pmdmapped: %lukB"
5566 " writeback_tmp:%lukB"
5567 " kernel_stack:%lukB"
5568 #ifdef CONFIG_SHADOW_CALL_STACK
5569 " shadow_call_stack:%lukB"
5572 " all_unreclaimable? %s"
5575 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
5576 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
5577 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
5578 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
5579 K(node_page_state(pgdat, NR_UNEVICTABLE)),
5580 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
5581 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
5582 K(node_page_state(pgdat, NR_FILE_MAPPED)),
5583 K(node_page_state(pgdat, NR_FILE_DIRTY)),
5584 K(node_page_state(pgdat, NR_WRITEBACK)),
5585 K(node_page_state(pgdat, NR_SHMEM)),
5586 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5587 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
5588 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
5590 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
5592 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
5593 node_page_state(pgdat, NR_KERNEL_STACK_KB),
5594 #ifdef CONFIG_SHADOW_CALL_STACK
5595 node_page_state(pgdat, NR_KERNEL_SCS_KB),
5597 K(node_page_state(pgdat, NR_PAGETABLE)),
5598 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
5602 for_each_populated_zone(zone) {
5605 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5609 for_each_online_cpu(cpu)
5610 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
5619 " reserved_highatomic:%luKB"
5620 " active_anon:%lukB"
5621 " inactive_anon:%lukB"
5622 " active_file:%lukB"
5623 " inactive_file:%lukB"
5624 " unevictable:%lukB"
5625 " writepending:%lukB"
5635 K(zone_page_state(zone, NR_FREE_PAGES)),
5636 K(min_wmark_pages(zone)),
5637 K(low_wmark_pages(zone)),
5638 K(high_wmark_pages(zone)),
5639 K(zone->nr_reserved_highatomic),
5640 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
5641 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
5642 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
5643 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
5644 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
5645 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
5646 K(zone->present_pages),
5647 K(zone_managed_pages(zone)),
5648 K(zone_page_state(zone, NR_MLOCK)),
5649 K(zone_page_state(zone, NR_BOUNCE)),
5651 K(this_cpu_read(zone->pageset->pcp.count)),
5652 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
5653 printk("lowmem_reserve[]:");
5654 for (i = 0; i < MAX_NR_ZONES; i++)
5655 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
5656 printk(KERN_CONT "\n");
5659 for_each_populated_zone(zone) {
5661 unsigned long nr[MAX_ORDER], flags, total = 0;
5662 unsigned char types[MAX_ORDER];
5664 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5667 printk(KERN_CONT "%s: ", zone->name);
5669 spin_lock_irqsave(&zone->lock, flags);
5670 for (order = 0; order < MAX_ORDER; order++) {
5671 struct free_area *area = &zone->free_area[order];
5674 nr[order] = area->nr_free;
5675 total += nr[order] << order;
5678 for (type = 0; type < MIGRATE_TYPES; type++) {
5679 if (!free_area_empty(area, type))
5680 types[order] |= 1 << type;
5683 spin_unlock_irqrestore(&zone->lock, flags);
5684 for (order = 0; order < MAX_ORDER; order++) {
5685 printk(KERN_CONT "%lu*%lukB ",
5686 nr[order], K(1UL) << order);
5688 show_migration_types(types[order]);
5690 printk(KERN_CONT "= %lukB\n", K(total));
5693 hugetlb_show_meminfo();
5695 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
5697 show_swap_cache_info();
5700 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
5702 zoneref->zone = zone;
5703 zoneref->zone_idx = zone_idx(zone);
5707 * Builds allocation fallback zone lists.
5709 * Add all populated zones of a node to the zonelist.
5711 static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
5714 enum zone_type zone_type = MAX_NR_ZONES;
5719 zone = pgdat->node_zones + zone_type;
5720 if (managed_zone(zone)) {
5721 zoneref_set_zone(zone, &zonerefs[nr_zones++]);
5722 check_highest_zone(zone_type);
5724 } while (zone_type);
5731 static int __parse_numa_zonelist_order(char *s)
5734 * We used to support different zonlists modes but they turned
5735 * out to be just not useful. Let's keep the warning in place
5736 * if somebody still use the cmd line parameter so that we do
5737 * not fail it silently
5739 if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
5740 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
5746 char numa_zonelist_order[] = "Node";
5749 * sysctl handler for numa_zonelist_order
5751 int numa_zonelist_order_handler(struct ctl_table *table, int write,
5752 void *buffer, size_t *length, loff_t *ppos)
5755 return __parse_numa_zonelist_order(buffer);
5756 return proc_dostring(table, write, buffer, length, ppos);
5760 #define MAX_NODE_LOAD (nr_online_nodes)
5761 static int node_load[MAX_NUMNODES];
5764 * find_next_best_node - find the next node that should appear in a given node's fallback list
5765 * @node: node whose fallback list we're appending
5766 * @used_node_mask: nodemask_t of already used nodes
5768 * We use a number of factors to determine which is the next node that should
5769 * appear on a given node's fallback list. The node should not have appeared
5770 * already in @node's fallback list, and it should be the next closest node
5771 * according to the distance array (which contains arbitrary distance values
5772 * from each node to each node in the system), and should also prefer nodes
5773 * with no CPUs, since presumably they'll have very little allocation pressure
5774 * on them otherwise.
5776 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5778 static int find_next_best_node(int node, nodemask_t *used_node_mask)
5781 int min_val = INT_MAX;
5782 int best_node = NUMA_NO_NODE;
5784 /* Use the local node if we haven't already */
5785 if (!node_isset(node, *used_node_mask)) {
5786 node_set(node, *used_node_mask);
5790 for_each_node_state(n, N_MEMORY) {
5792 /* Don't want a node to appear more than once */
5793 if (node_isset(n, *used_node_mask))
5796 /* Use the distance array to find the distance */
5797 val = node_distance(node, n);
5799 /* Penalize nodes under us ("prefer the next node") */
5802 /* Give preference to headless and unused nodes */
5803 if (!cpumask_empty(cpumask_of_node(n)))
5804 val += PENALTY_FOR_NODE_WITH_CPUS;
5806 /* Slight preference for less loaded node */
5807 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
5808 val += node_load[n];
5810 if (val < min_val) {
5817 node_set(best_node, *used_node_mask);
5824 * Build zonelists ordered by node and zones within node.
5825 * This results in maximum locality--normal zone overflows into local
5826 * DMA zone, if any--but risks exhausting DMA zone.
5828 static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
5831 struct zoneref *zonerefs;
5834 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5836 for (i = 0; i < nr_nodes; i++) {
5839 pg_data_t *node = NODE_DATA(node_order[i]);
5841 nr_zones = build_zonerefs_node(node, zonerefs);
5842 zonerefs += nr_zones;
5844 zonerefs->zone = NULL;
5845 zonerefs->zone_idx = 0;
5849 * Build gfp_thisnode zonelists
5851 static void build_thisnode_zonelists(pg_data_t *pgdat)
5853 struct zoneref *zonerefs;
5856 zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
5857 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5858 zonerefs += nr_zones;
5859 zonerefs->zone = NULL;
5860 zonerefs->zone_idx = 0;
5864 * Build zonelists ordered by zone and nodes within zones.
5865 * This results in conserving DMA zone[s] until all Normal memory is
5866 * exhausted, but results in overflowing to remote node while memory
5867 * may still exist in local DMA zone.
5870 static void build_zonelists(pg_data_t *pgdat)
5872 static int node_order[MAX_NUMNODES];
5873 int node, load, nr_nodes = 0;
5874 nodemask_t used_mask = NODE_MASK_NONE;
5875 int local_node, prev_node;
5877 /* NUMA-aware ordering of nodes */
5878 local_node = pgdat->node_id;
5879 load = nr_online_nodes;
5880 prev_node = local_node;
5882 memset(node_order, 0, sizeof(node_order));
5883 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
5885 * We don't want to pressure a particular node.
5886 * So adding penalty to the first node in same
5887 * distance group to make it round-robin.
5889 if (node_distance(local_node, node) !=
5890 node_distance(local_node, prev_node))
5891 node_load[node] = load;
5893 node_order[nr_nodes++] = node;
5898 build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
5899 build_thisnode_zonelists(pgdat);
5902 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5904 * Return node id of node used for "local" allocations.
5905 * I.e., first node id of first zone in arg node's generic zonelist.
5906 * Used for initializing percpu 'numa_mem', which is used primarily
5907 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5909 int local_memory_node(int node)
5913 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
5914 gfp_zone(GFP_KERNEL),
5916 return zone_to_nid(z->zone);
5920 static void setup_min_unmapped_ratio(void);
5921 static void setup_min_slab_ratio(void);
5922 #else /* CONFIG_NUMA */
5924 static void build_zonelists(pg_data_t *pgdat)
5926 int node, local_node;
5927 struct zoneref *zonerefs;
5930 local_node = pgdat->node_id;
5932 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5933 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5934 zonerefs += nr_zones;
5937 * Now we build the zonelist so that it contains the zones
5938 * of all the other nodes.
5939 * We don't want to pressure a particular node, so when
5940 * building the zones for node N, we make sure that the
5941 * zones coming right after the local ones are those from
5942 * node N+1 (modulo N)
5944 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
5945 if (!node_online(node))
5947 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5948 zonerefs += nr_zones;
5950 for (node = 0; node < local_node; node++) {
5951 if (!node_online(node))
5953 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5954 zonerefs += nr_zones;
5957 zonerefs->zone = NULL;
5958 zonerefs->zone_idx = 0;
5961 #endif /* CONFIG_NUMA */
5964 * Boot pageset table. One per cpu which is going to be used for all
5965 * zones and all nodes. The parameters will be set in such a way
5966 * that an item put on a list will immediately be handed over to
5967 * the buddy list. This is safe since pageset manipulation is done
5968 * with interrupts disabled.
5970 * The boot_pagesets must be kept even after bootup is complete for
5971 * unused processors and/or zones. They do play a role for bootstrapping
5972 * hotplugged processors.
5974 * zoneinfo_show() and maybe other functions do
5975 * not check if the processor is online before following the pageset pointer.
5976 * Other parts of the kernel may not check if the zone is available.
5978 static void pageset_init(struct per_cpu_pageset *p);
5979 /* These effectively disable the pcplists in the boot pageset completely */
5980 #define BOOT_PAGESET_HIGH 0
5981 #define BOOT_PAGESET_BATCH 1
5982 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
5983 static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
5985 static void __build_all_zonelists(void *data)
5988 int __maybe_unused cpu;
5989 pg_data_t *self = data;
5990 static DEFINE_SPINLOCK(lock);
5995 memset(node_load, 0, sizeof(node_load));
5999 * This node is hotadded and no memory is yet present. So just
6000 * building zonelists is fine - no need to touch other nodes.
6002 if (self && !node_online(self->node_id)) {
6003 build_zonelists(self);
6005 for_each_online_node(nid) {
6006 pg_data_t *pgdat = NODE_DATA(nid);
6008 build_zonelists(pgdat);
6011 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
6013 * We now know the "local memory node" for each node--
6014 * i.e., the node of the first zone in the generic zonelist.
6015 * Set up numa_mem percpu variable for on-line cpus. During
6016 * boot, only the boot cpu should be on-line; we'll init the
6017 * secondary cpus' numa_mem as they come on-line. During
6018 * node/memory hotplug, we'll fixup all on-line cpus.
6020 for_each_online_cpu(cpu)
6021 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
6028 static noinline void __init
6029 build_all_zonelists_init(void)
6033 __build_all_zonelists(NULL);
6036 * Initialize the boot_pagesets that are going to be used
6037 * for bootstrapping processors. The real pagesets for
6038 * each zone will be allocated later when the per cpu
6039 * allocator is available.
6041 * boot_pagesets are used also for bootstrapping offline
6042 * cpus if the system is already booted because the pagesets
6043 * are needed to initialize allocators on a specific cpu too.
6044 * F.e. the percpu allocator needs the page allocator which
6045 * needs the percpu allocator in order to allocate its pagesets
6046 * (a chicken-egg dilemma).
6048 for_each_possible_cpu(cpu)
6049 pageset_init(&per_cpu(boot_pageset, cpu));
6051 mminit_verify_zonelist();
6052 cpuset_init_current_mems_allowed();
6056 * unless system_state == SYSTEM_BOOTING.
6058 * __ref due to call of __init annotated helper build_all_zonelists_init
6059 * [protected by SYSTEM_BOOTING].
6061 void __ref build_all_zonelists(pg_data_t *pgdat)
6063 unsigned long vm_total_pages;
6065 if (system_state == SYSTEM_BOOTING) {
6066 build_all_zonelists_init();
6068 __build_all_zonelists(pgdat);
6069 /* cpuset refresh routine should be here */
6071 /* Get the number of free pages beyond high watermark in all zones. */
6072 vm_total_pages = nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
6074 * Disable grouping by mobility if the number of pages in the
6075 * system is too low to allow the mechanism to work. It would be
6076 * more accurate, but expensive to check per-zone. This check is
6077 * made on memory-hotadd so a system can start with mobility
6078 * disabled and enable it later
6080 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
6081 page_group_by_mobility_disabled = 1;
6083 page_group_by_mobility_disabled = 0;
6085 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
6087 page_group_by_mobility_disabled ? "off" : "on",
6090 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
6094 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
6095 static bool __meminit
6096 overlap_memmap_init(unsigned long zone, unsigned long *pfn)
6098 static struct memblock_region *r;
6100 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
6101 if (!r || *pfn >= memblock_region_memory_end_pfn(r)) {
6102 for_each_mem_region(r) {
6103 if (*pfn < memblock_region_memory_end_pfn(r))
6107 if (*pfn >= memblock_region_memory_base_pfn(r) &&
6108 memblock_is_mirror(r)) {
6109 *pfn = memblock_region_memory_end_pfn(r);
6117 * Initially all pages are reserved - free ones are freed
6118 * up by memblock_free_all() once the early boot process is
6119 * done. Non-atomic initialization, single-pass.
6121 * All aligned pageblocks are initialized to the specified migratetype
6122 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related
6123 * zone stats (e.g., nr_isolate_pageblock) are touched.
6125 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
6126 unsigned long start_pfn, unsigned long zone_end_pfn,
6127 enum meminit_context context,
6128 struct vmem_altmap *altmap, int migratetype)
6130 unsigned long pfn, end_pfn = start_pfn + size;
6133 if (highest_memmap_pfn < end_pfn - 1)
6134 highest_memmap_pfn = end_pfn - 1;
6136 #ifdef CONFIG_ZONE_DEVICE
6138 * Honor reservation requested by the driver for this ZONE_DEVICE
6139 * memory. We limit the total number of pages to initialize to just
6140 * those that might contain the memory mapping. We will defer the
6141 * ZONE_DEVICE page initialization until after we have released
6144 if (zone == ZONE_DEVICE) {
6148 if (start_pfn == altmap->base_pfn)
6149 start_pfn += altmap->reserve;
6150 end_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6154 for (pfn = start_pfn; pfn < end_pfn; ) {
6156 * There can be holes in boot-time mem_map[]s handed to this
6157 * function. They do not exist on hotplugged memory.
6159 if (context == MEMINIT_EARLY) {
6160 if (overlap_memmap_init(zone, &pfn))
6162 if (defer_init(nid, pfn, zone_end_pfn))
6166 page = pfn_to_page(pfn);
6167 __init_single_page(page, pfn, zone, nid);
6168 if (context == MEMINIT_HOTPLUG)
6169 __SetPageReserved(page);
6172 * Usually, we want to mark the pageblock MIGRATE_MOVABLE,
6173 * such that unmovable allocations won't be scattered all
6174 * over the place during system boot.
6176 if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
6177 set_pageblock_migratetype(page, migratetype);
6184 #ifdef CONFIG_ZONE_DEVICE
6185 void __ref memmap_init_zone_device(struct zone *zone,
6186 unsigned long start_pfn,
6187 unsigned long nr_pages,
6188 struct dev_pagemap *pgmap)
6190 unsigned long pfn, end_pfn = start_pfn + nr_pages;
6191 struct pglist_data *pgdat = zone->zone_pgdat;
6192 struct vmem_altmap *altmap = pgmap_altmap(pgmap);
6193 unsigned long zone_idx = zone_idx(zone);
6194 unsigned long start = jiffies;
6195 int nid = pgdat->node_id;
6197 if (WARN_ON_ONCE(!pgmap || zone_idx(zone) != ZONE_DEVICE))
6201 * The call to memmap_init_zone should have already taken care
6202 * of the pages reserved for the memmap, so we can just jump to
6203 * the end of that region and start processing the device pages.
6206 start_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
6207 nr_pages = end_pfn - start_pfn;
6210 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
6211 struct page *page = pfn_to_page(pfn);
6213 __init_single_page(page, pfn, zone_idx, nid);
6216 * Mark page reserved as it will need to wait for onlining
6217 * phase for it to be fully associated with a zone.
6219 * We can use the non-atomic __set_bit operation for setting
6220 * the flag as we are still initializing the pages.
6222 __SetPageReserved(page);
6225 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6226 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6227 * ever freed or placed on a driver-private list.
6229 page->pgmap = pgmap;
6230 page->zone_device_data = NULL;
6233 * Mark the block movable so that blocks are reserved for
6234 * movable at startup. This will force kernel allocations
6235 * to reserve their blocks rather than leaking throughout
6236 * the address space during boot when many long-lived
6237 * kernel allocations are made.
6239 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6240 * because this is done early in section_activate()
6242 if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
6243 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
6248 pr_info("%s initialised %lu pages in %ums\n", __func__,
6249 nr_pages, jiffies_to_msecs(jiffies - start));
6253 static void __meminit zone_init_free_lists(struct zone *zone)
6255 unsigned int order, t;
6256 for_each_migratetype_order(order, t) {
6257 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
6258 zone->free_area[order].nr_free = 0;
6262 void __meminit __weak memmap_init(unsigned long size, int nid,
6264 unsigned long range_start_pfn)
6266 unsigned long start_pfn, end_pfn;
6267 unsigned long range_end_pfn = range_start_pfn + size;
6270 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6271 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
6272 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
6274 if (end_pfn > start_pfn) {
6275 size = end_pfn - start_pfn;
6276 memmap_init_zone(size, nid, zone, start_pfn, range_end_pfn,
6277 MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
6282 static int zone_batchsize(struct zone *zone)
6288 * The per-cpu-pages pools are set to around 1000th of the
6291 batch = zone_managed_pages(zone) / 1024;
6292 /* But no more than a meg. */
6293 if (batch * PAGE_SIZE > 1024 * 1024)
6294 batch = (1024 * 1024) / PAGE_SIZE;
6295 batch /= 4; /* We effectively *= 4 below */
6300 * Clamp the batch to a 2^n - 1 value. Having a power
6301 * of 2 value was found to be more likely to have
6302 * suboptimal cache aliasing properties in some cases.
6304 * For example if 2 tasks are alternately allocating
6305 * batches of pages, one task can end up with a lot
6306 * of pages of one half of the possible page colors
6307 * and the other with pages of the other colors.
6309 batch = rounddown_pow_of_two(batch + batch/2) - 1;
6314 /* The deferral and batching of frees should be suppressed under NOMMU
6317 * The problem is that NOMMU needs to be able to allocate large chunks
6318 * of contiguous memory as there's no hardware page translation to
6319 * assemble apparent contiguous memory from discontiguous pages.
6321 * Queueing large contiguous runs of pages for batching, however,
6322 * causes the pages to actually be freed in smaller chunks. As there
6323 * can be a significant delay between the individual batches being
6324 * recycled, this leads to the once large chunks of space being
6325 * fragmented and becoming unavailable for high-order allocations.
6332 * pcp->high and pcp->batch values are related and generally batch is lower
6333 * than high. They are also related to pcp->count such that count is lower
6334 * than high, and as soon as it reaches high, the pcplist is flushed.
6336 * However, guaranteeing these relations at all times would require e.g. write
6337 * barriers here but also careful usage of read barriers at the read side, and
6338 * thus be prone to error and bad for performance. Thus the update only prevents
6339 * store tearing. Any new users of pcp->batch and pcp->high should ensure they
6340 * can cope with those fields changing asynchronously, and fully trust only the
6341 * pcp->count field on the local CPU with interrupts disabled.
6343 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6344 * outside of boot time (or some other assurance that no concurrent updaters
6347 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
6348 unsigned long batch)
6350 WRITE_ONCE(pcp->batch, batch);
6351 WRITE_ONCE(pcp->high, high);
6354 static void pageset_init(struct per_cpu_pageset *p)
6356 struct per_cpu_pages *pcp;
6359 memset(p, 0, sizeof(*p));
6362 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
6363 INIT_LIST_HEAD(&pcp->lists[migratetype]);
6366 * Set batch and high values safe for a boot pageset. A true percpu
6367 * pageset's initialization will update them subsequently. Here we don't
6368 * need to be as careful as pageset_update() as nobody can access the
6371 pcp->high = BOOT_PAGESET_HIGH;
6372 pcp->batch = BOOT_PAGESET_BATCH;
6375 static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high,
6376 unsigned long batch)
6378 struct per_cpu_pageset *p;
6381 for_each_possible_cpu(cpu) {
6382 p = per_cpu_ptr(zone->pageset, cpu);
6383 pageset_update(&p->pcp, high, batch);
6388 * Calculate and set new high and batch values for all per-cpu pagesets of a
6389 * zone, based on the zone's size and the percpu_pagelist_fraction sysctl.
6391 static void zone_set_pageset_high_and_batch(struct zone *zone)
6393 unsigned long new_high, new_batch;
6395 if (percpu_pagelist_fraction) {
6396 new_high = zone_managed_pages(zone) / percpu_pagelist_fraction;
6397 new_batch = max(1UL, new_high / 4);
6398 if ((new_high / 4) > (PAGE_SHIFT * 8))
6399 new_batch = PAGE_SHIFT * 8;
6401 new_batch = zone_batchsize(zone);
6402 new_high = 6 * new_batch;
6403 new_batch = max(1UL, 1 * new_batch);
6406 if (zone->pageset_high == new_high &&
6407 zone->pageset_batch == new_batch)
6410 zone->pageset_high = new_high;
6411 zone->pageset_batch = new_batch;
6413 __zone_set_pageset_high_and_batch(zone, new_high, new_batch);
6416 void __meminit setup_zone_pageset(struct zone *zone)
6418 struct per_cpu_pageset *p;
6421 zone->pageset = alloc_percpu(struct per_cpu_pageset);
6422 for_each_possible_cpu(cpu) {
6423 p = per_cpu_ptr(zone->pageset, cpu);
6427 zone_set_pageset_high_and_batch(zone);
6431 * Allocate per cpu pagesets and initialize them.
6432 * Before this call only boot pagesets were available.
6434 void __init setup_per_cpu_pageset(void)
6436 struct pglist_data *pgdat;
6438 int __maybe_unused cpu;
6440 for_each_populated_zone(zone)
6441 setup_zone_pageset(zone);
6445 * Unpopulated zones continue using the boot pagesets.
6446 * The numa stats for these pagesets need to be reset.
6447 * Otherwise, they will end up skewing the stats of
6448 * the nodes these zones are associated with.
6450 for_each_possible_cpu(cpu) {
6451 struct per_cpu_pageset *pcp = &per_cpu(boot_pageset, cpu);
6452 memset(pcp->vm_numa_stat_diff, 0,
6453 sizeof(pcp->vm_numa_stat_diff));
6457 for_each_online_pgdat(pgdat)
6458 pgdat->per_cpu_nodestats =
6459 alloc_percpu(struct per_cpu_nodestat);
6462 static __meminit void zone_pcp_init(struct zone *zone)
6465 * per cpu subsystem is not up at this point. The following code
6466 * relies on the ability of the linker to provide the
6467 * offset of a (static) per cpu variable into the per cpu area.
6469 zone->pageset = &boot_pageset;
6470 zone->pageset_high = BOOT_PAGESET_HIGH;
6471 zone->pageset_batch = BOOT_PAGESET_BATCH;
6473 if (populated_zone(zone))
6474 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
6475 zone->name, zone->present_pages,
6476 zone_batchsize(zone));
6479 void __meminit init_currently_empty_zone(struct zone *zone,
6480 unsigned long zone_start_pfn,
6483 struct pglist_data *pgdat = zone->zone_pgdat;
6484 int zone_idx = zone_idx(zone) + 1;
6486 if (zone_idx > pgdat->nr_zones)
6487 pgdat->nr_zones = zone_idx;
6489 zone->zone_start_pfn = zone_start_pfn;
6491 mminit_dprintk(MMINIT_TRACE, "memmap_init",
6492 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6494 (unsigned long)zone_idx(zone),
6495 zone_start_pfn, (zone_start_pfn + size));
6497 zone_init_free_lists(zone);
6498 zone->initialized = 1;
6502 * get_pfn_range_for_nid - Return the start and end page frames for a node
6503 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6504 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6505 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6507 * It returns the start and end page frame of a node based on information
6508 * provided by memblock_set_node(). If called for a node
6509 * with no available memory, a warning is printed and the start and end
6512 void __init get_pfn_range_for_nid(unsigned int nid,
6513 unsigned long *start_pfn, unsigned long *end_pfn)
6515 unsigned long this_start_pfn, this_end_pfn;
6521 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
6522 *start_pfn = min(*start_pfn, this_start_pfn);
6523 *end_pfn = max(*end_pfn, this_end_pfn);
6526 if (*start_pfn == -1UL)
6531 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6532 * assumption is made that zones within a node are ordered in monotonic
6533 * increasing memory addresses so that the "highest" populated zone is used
6535 static void __init find_usable_zone_for_movable(void)
6538 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
6539 if (zone_index == ZONE_MOVABLE)
6542 if (arch_zone_highest_possible_pfn[zone_index] >
6543 arch_zone_lowest_possible_pfn[zone_index])
6547 VM_BUG_ON(zone_index == -1);
6548 movable_zone = zone_index;
6552 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6553 * because it is sized independent of architecture. Unlike the other zones,
6554 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6555 * in each node depending on the size of each node and how evenly kernelcore
6556 * is distributed. This helper function adjusts the zone ranges
6557 * provided by the architecture for a given node by using the end of the
6558 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6559 * zones within a node are in order of monotonic increases memory addresses
6561 static void __init adjust_zone_range_for_zone_movable(int nid,
6562 unsigned long zone_type,
6563 unsigned long node_start_pfn,
6564 unsigned long node_end_pfn,
6565 unsigned long *zone_start_pfn,
6566 unsigned long *zone_end_pfn)
6568 /* Only adjust if ZONE_MOVABLE is on this node */
6569 if (zone_movable_pfn[nid]) {
6570 /* Size ZONE_MOVABLE */
6571 if (zone_type == ZONE_MOVABLE) {
6572 *zone_start_pfn = zone_movable_pfn[nid];
6573 *zone_end_pfn = min(node_end_pfn,
6574 arch_zone_highest_possible_pfn[movable_zone]);
6576 /* Adjust for ZONE_MOVABLE starting within this range */
6577 } else if (!mirrored_kernelcore &&
6578 *zone_start_pfn < zone_movable_pfn[nid] &&
6579 *zone_end_pfn > zone_movable_pfn[nid]) {
6580 *zone_end_pfn = zone_movable_pfn[nid];
6582 /* Check if this whole range is within ZONE_MOVABLE */
6583 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
6584 *zone_start_pfn = *zone_end_pfn;
6589 * Return the number of pages a zone spans in a node, including holes
6590 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6592 static unsigned long __init zone_spanned_pages_in_node(int nid,
6593 unsigned long zone_type,
6594 unsigned long node_start_pfn,
6595 unsigned long node_end_pfn,
6596 unsigned long *zone_start_pfn,
6597 unsigned long *zone_end_pfn)
6599 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6600 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6601 /* When hotadd a new node from cpu_up(), the node should be empty */
6602 if (!node_start_pfn && !node_end_pfn)
6605 /* Get the start and end of the zone */
6606 *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6607 *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6608 adjust_zone_range_for_zone_movable(nid, zone_type,
6609 node_start_pfn, node_end_pfn,
6610 zone_start_pfn, zone_end_pfn);
6612 /* Check that this node has pages within the zone's required range */
6613 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
6616 /* Move the zone boundaries inside the node if necessary */
6617 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
6618 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
6620 /* Return the spanned pages */
6621 return *zone_end_pfn - *zone_start_pfn;
6625 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6626 * then all holes in the requested range will be accounted for.
6628 unsigned long __init __absent_pages_in_range(int nid,
6629 unsigned long range_start_pfn,
6630 unsigned long range_end_pfn)
6632 unsigned long nr_absent = range_end_pfn - range_start_pfn;
6633 unsigned long start_pfn, end_pfn;
6636 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6637 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
6638 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
6639 nr_absent -= end_pfn - start_pfn;
6645 * absent_pages_in_range - Return number of page frames in holes within a range
6646 * @start_pfn: The start PFN to start searching for holes
6647 * @end_pfn: The end PFN to stop searching for holes
6649 * Return: the number of pages frames in memory holes within a range.
6651 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
6652 unsigned long end_pfn)
6654 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
6657 /* Return the number of page frames in holes in a zone on a node */
6658 static unsigned long __init zone_absent_pages_in_node(int nid,
6659 unsigned long zone_type,
6660 unsigned long node_start_pfn,
6661 unsigned long node_end_pfn)
6663 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6664 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6665 unsigned long zone_start_pfn, zone_end_pfn;
6666 unsigned long nr_absent;
6668 /* When hotadd a new node from cpu_up(), the node should be empty */
6669 if (!node_start_pfn && !node_end_pfn)
6672 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6673 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6675 adjust_zone_range_for_zone_movable(nid, zone_type,
6676 node_start_pfn, node_end_pfn,
6677 &zone_start_pfn, &zone_end_pfn);
6678 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
6681 * ZONE_MOVABLE handling.
6682 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6685 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
6686 unsigned long start_pfn, end_pfn;
6687 struct memblock_region *r;
6689 for_each_mem_region(r) {
6690 start_pfn = clamp(memblock_region_memory_base_pfn(r),
6691 zone_start_pfn, zone_end_pfn);
6692 end_pfn = clamp(memblock_region_memory_end_pfn(r),
6693 zone_start_pfn, zone_end_pfn);
6695 if (zone_type == ZONE_MOVABLE &&
6696 memblock_is_mirror(r))
6697 nr_absent += end_pfn - start_pfn;
6699 if (zone_type == ZONE_NORMAL &&
6700 !memblock_is_mirror(r))
6701 nr_absent += end_pfn - start_pfn;
6708 static void __init calculate_node_totalpages(struct pglist_data *pgdat,
6709 unsigned long node_start_pfn,
6710 unsigned long node_end_pfn)
6712 unsigned long realtotalpages = 0, totalpages = 0;
6715 for (i = 0; i < MAX_NR_ZONES; i++) {
6716 struct zone *zone = pgdat->node_zones + i;
6717 unsigned long zone_start_pfn, zone_end_pfn;
6718 unsigned long spanned, absent;
6719 unsigned long size, real_size;
6721 spanned = zone_spanned_pages_in_node(pgdat->node_id, i,
6726 absent = zone_absent_pages_in_node(pgdat->node_id, i,
6731 real_size = size - absent;
6734 zone->zone_start_pfn = zone_start_pfn;
6736 zone->zone_start_pfn = 0;
6737 zone->spanned_pages = size;
6738 zone->present_pages = real_size;
6741 realtotalpages += real_size;
6744 pgdat->node_spanned_pages = totalpages;
6745 pgdat->node_present_pages = realtotalpages;
6746 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
6750 #ifndef CONFIG_SPARSEMEM
6752 * Calculate the size of the zone->blockflags rounded to an unsigned long
6753 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6754 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6755 * round what is now in bits to nearest long in bits, then return it in
6758 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
6760 unsigned long usemapsize;
6762 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
6763 usemapsize = roundup(zonesize, pageblock_nr_pages);
6764 usemapsize = usemapsize >> pageblock_order;
6765 usemapsize *= NR_PAGEBLOCK_BITS;
6766 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
6768 return usemapsize / 8;
6771 static void __ref setup_usemap(struct pglist_data *pgdat,
6773 unsigned long zone_start_pfn,
6774 unsigned long zonesize)
6776 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
6777 zone->pageblock_flags = NULL;
6779 zone->pageblock_flags =
6780 memblock_alloc_node(usemapsize, SMP_CACHE_BYTES,
6782 if (!zone->pageblock_flags)
6783 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6784 usemapsize, zone->name, pgdat->node_id);
6788 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
6789 unsigned long zone_start_pfn, unsigned long zonesize) {}
6790 #endif /* CONFIG_SPARSEMEM */
6792 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6794 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6795 void __init set_pageblock_order(void)
6799 /* Check that pageblock_nr_pages has not already been setup */
6800 if (pageblock_order)
6803 if (HPAGE_SHIFT > PAGE_SHIFT)
6804 order = HUGETLB_PAGE_ORDER;
6806 order = MAX_ORDER - 1;
6809 * Assume the largest contiguous order of interest is a huge page.
6810 * This value may be variable depending on boot parameters on IA64 and
6813 pageblock_order = order;
6815 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6818 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6819 * is unused as pageblock_order is set at compile-time. See
6820 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6823 void __init set_pageblock_order(void)
6827 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6829 static unsigned long __init calc_memmap_size(unsigned long spanned_pages,
6830 unsigned long present_pages)
6832 unsigned long pages = spanned_pages;
6835 * Provide a more accurate estimation if there are holes within
6836 * the zone and SPARSEMEM is in use. If there are holes within the
6837 * zone, each populated memory region may cost us one or two extra
6838 * memmap pages due to alignment because memmap pages for each
6839 * populated regions may not be naturally aligned on page boundary.
6840 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6842 if (spanned_pages > present_pages + (present_pages >> 4) &&
6843 IS_ENABLED(CONFIG_SPARSEMEM))
6844 pages = present_pages;
6846 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
6849 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6850 static void pgdat_init_split_queue(struct pglist_data *pgdat)
6852 struct deferred_split *ds_queue = &pgdat->deferred_split_queue;
6854 spin_lock_init(&ds_queue->split_queue_lock);
6855 INIT_LIST_HEAD(&ds_queue->split_queue);
6856 ds_queue->split_queue_len = 0;
6859 static void pgdat_init_split_queue(struct pglist_data *pgdat) {}
6862 #ifdef CONFIG_COMPACTION
6863 static void pgdat_init_kcompactd(struct pglist_data *pgdat)
6865 init_waitqueue_head(&pgdat->kcompactd_wait);
6868 static void pgdat_init_kcompactd(struct pglist_data *pgdat) {}
6871 static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
6873 pgdat_resize_init(pgdat);
6875 pgdat_init_split_queue(pgdat);
6876 pgdat_init_kcompactd(pgdat);
6878 init_waitqueue_head(&pgdat->kswapd_wait);
6879 init_waitqueue_head(&pgdat->pfmemalloc_wait);
6881 pgdat_page_ext_init(pgdat);
6882 lruvec_init(&pgdat->__lruvec);
6885 static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,
6886 unsigned long remaining_pages)
6888 atomic_long_set(&zone->managed_pages, remaining_pages);
6889 zone_set_nid(zone, nid);
6890 zone->name = zone_names[idx];
6891 zone->zone_pgdat = NODE_DATA(nid);
6892 spin_lock_init(&zone->lock);
6893 zone_seqlock_init(zone);
6894 zone_pcp_init(zone);
6898 * Set up the zone data structures
6899 * - init pgdat internals
6900 * - init all zones belonging to this node
6902 * NOTE: this function is only called during memory hotplug
6904 #ifdef CONFIG_MEMORY_HOTPLUG
6905 void __ref free_area_init_core_hotplug(int nid)
6908 pg_data_t *pgdat = NODE_DATA(nid);
6910 pgdat_init_internals(pgdat);
6911 for (z = 0; z < MAX_NR_ZONES; z++)
6912 zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
6917 * Set up the zone data structures:
6918 * - mark all pages reserved
6919 * - mark all memory queues empty
6920 * - clear the memory bitmaps
6922 * NOTE: pgdat should get zeroed by caller.
6923 * NOTE: this function is only called during early init.
6925 static void __init free_area_init_core(struct pglist_data *pgdat)
6928 int nid = pgdat->node_id;
6930 pgdat_init_internals(pgdat);
6931 pgdat->per_cpu_nodestats = &boot_nodestats;
6933 for (j = 0; j < MAX_NR_ZONES; j++) {
6934 struct zone *zone = pgdat->node_zones + j;
6935 unsigned long size, freesize, memmap_pages;
6936 unsigned long zone_start_pfn = zone->zone_start_pfn;
6938 size = zone->spanned_pages;
6939 freesize = zone->present_pages;
6942 * Adjust freesize so that it accounts for how much memory
6943 * is used by this zone for memmap. This affects the watermark
6944 * and per-cpu initialisations
6946 memmap_pages = calc_memmap_size(size, freesize);
6947 if (!is_highmem_idx(j)) {
6948 if (freesize >= memmap_pages) {
6949 freesize -= memmap_pages;
6952 " %s zone: %lu pages used for memmap\n",
6953 zone_names[j], memmap_pages);
6955 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6956 zone_names[j], memmap_pages, freesize);
6959 /* Account for reserved pages */
6960 if (j == 0 && freesize > dma_reserve) {
6961 freesize -= dma_reserve;
6962 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
6963 zone_names[0], dma_reserve);
6966 if (!is_highmem_idx(j))
6967 nr_kernel_pages += freesize;
6968 /* Charge for highmem memmap if there are enough kernel pages */
6969 else if (nr_kernel_pages > memmap_pages * 2)
6970 nr_kernel_pages -= memmap_pages;
6971 nr_all_pages += freesize;
6974 * Set an approximate value for lowmem here, it will be adjusted
6975 * when the bootmem allocator frees pages into the buddy system.
6976 * And all highmem pages will be managed by the buddy system.
6978 zone_init_internals(zone, j, nid, freesize);
6983 set_pageblock_order();
6984 setup_usemap(pgdat, zone, zone_start_pfn, size);
6985 init_currently_empty_zone(zone, zone_start_pfn, size);
6986 memmap_init(size, nid, j, zone_start_pfn);
6990 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6991 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
6993 unsigned long __maybe_unused start = 0;
6994 unsigned long __maybe_unused offset = 0;
6996 /* Skip empty nodes */
6997 if (!pgdat->node_spanned_pages)
7000 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
7001 offset = pgdat->node_start_pfn - start;
7002 /* ia64 gets its own node_mem_map, before this, without bootmem */
7003 if (!pgdat->node_mem_map) {
7004 unsigned long size, end;
7008 * The zone's endpoints aren't required to be MAX_ORDER
7009 * aligned but the node_mem_map endpoints must be in order
7010 * for the buddy allocator to function correctly.
7012 end = pgdat_end_pfn(pgdat);
7013 end = ALIGN(end, MAX_ORDER_NR_PAGES);
7014 size = (end - start) * sizeof(struct page);
7015 map = memblock_alloc_node(size, SMP_CACHE_BYTES,
7018 panic("Failed to allocate %ld bytes for node %d memory map\n",
7019 size, pgdat->node_id);
7020 pgdat->node_mem_map = map + offset;
7022 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
7023 __func__, pgdat->node_id, (unsigned long)pgdat,
7024 (unsigned long)pgdat->node_mem_map);
7025 #ifndef CONFIG_NEED_MULTIPLE_NODES
7027 * With no DISCONTIG, the global mem_map is just set as node 0's
7029 if (pgdat == NODE_DATA(0)) {
7030 mem_map = NODE_DATA(0)->node_mem_map;
7031 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
7037 static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
7038 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
7040 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
7041 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
7043 pgdat->first_deferred_pfn = ULONG_MAX;
7046 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
7049 static void __init free_area_init_node(int nid)
7051 pg_data_t *pgdat = NODE_DATA(nid);
7052 unsigned long start_pfn = 0;
7053 unsigned long end_pfn = 0;
7055 /* pg_data_t should be reset to zero when it's allocated */
7056 WARN_ON(pgdat->nr_zones || pgdat->kswapd_highest_zoneidx);
7058 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
7060 pgdat->node_id = nid;
7061 pgdat->node_start_pfn = start_pfn;
7062 pgdat->per_cpu_nodestats = NULL;
7064 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
7065 (u64)start_pfn << PAGE_SHIFT,
7066 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
7067 calculate_node_totalpages(pgdat, start_pfn, end_pfn);
7069 alloc_node_mem_map(pgdat);
7070 pgdat_set_deferred_range(pgdat);
7072 free_area_init_core(pgdat);
7075 void __init free_area_init_memoryless_node(int nid)
7077 free_area_init_node(nid);
7080 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
7082 * Initialize all valid struct pages in the range [spfn, epfn) and mark them
7083 * PageReserved(). Return the number of struct pages that were initialized.
7085 static u64 __init init_unavailable_range(unsigned long spfn, unsigned long epfn)
7090 for (pfn = spfn; pfn < epfn; pfn++) {
7091 if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
7092 pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
7093 + pageblock_nr_pages - 1;
7097 * Use a fake node/zone (0) for now. Some of these pages
7098 * (in memblock.reserved but not in memblock.memory) will
7099 * get re-initialized via reserve_bootmem_region() later.
7101 __init_single_page(pfn_to_page(pfn), pfn, 0, 0);
7102 __SetPageReserved(pfn_to_page(pfn));
7110 * Only struct pages that are backed by physical memory are zeroed and
7111 * initialized by going through __init_single_page(). But, there are some
7112 * struct pages which are reserved in memblock allocator and their fields
7113 * may be accessed (for example page_to_pfn() on some configuration accesses
7114 * flags). We must explicitly initialize those struct pages.
7116 * This function also addresses a similar issue where struct pages are left
7117 * uninitialized because the physical address range is not covered by
7118 * memblock.memory or memblock.reserved. That could happen when memblock
7119 * layout is manually configured via memmap=, or when the highest physical
7120 * address (max_pfn) does not end on a section boundary.
7122 static void __init init_unavailable_mem(void)
7124 phys_addr_t start, end;
7126 phys_addr_t next = 0;
7129 * Loop through unavailable ranges not covered by memblock.memory.
7132 for_each_mem_range(i, &start, &end) {
7134 pgcnt += init_unavailable_range(PFN_DOWN(next),
7140 * Early sections always have a fully populated memmap for the whole
7141 * section - see pfn_valid(). If the last section has holes at the
7142 * end and that section is marked "online", the memmap will be
7143 * considered initialized. Make sure that memmap has a well defined
7146 pgcnt += init_unavailable_range(PFN_DOWN(next),
7147 round_up(max_pfn, PAGES_PER_SECTION));
7150 * Struct pages that do not have backing memory. This could be because
7151 * firmware is using some of this memory, or for some other reasons.
7154 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt);
7157 static inline void __init init_unavailable_mem(void)
7160 #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
7162 #if MAX_NUMNODES > 1
7164 * Figure out the number of possible node ids.
7166 void __init setup_nr_node_ids(void)
7168 unsigned int highest;
7170 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
7171 nr_node_ids = highest + 1;
7176 * node_map_pfn_alignment - determine the maximum internode alignment
7178 * This function should be called after node map is populated and sorted.
7179 * It calculates the maximum power of two alignment which can distinguish
7182 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7183 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7184 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7185 * shifted, 1GiB is enough and this function will indicate so.
7187 * This is used to test whether pfn -> nid mapping of the chosen memory
7188 * model has fine enough granularity to avoid incorrect mapping for the
7189 * populated node map.
7191 * Return: the determined alignment in pfn's. 0 if there is no alignment
7192 * requirement (single node).
7194 unsigned long __init node_map_pfn_alignment(void)
7196 unsigned long accl_mask = 0, last_end = 0;
7197 unsigned long start, end, mask;
7198 int last_nid = NUMA_NO_NODE;
7201 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
7202 if (!start || last_nid < 0 || last_nid == nid) {
7209 * Start with a mask granular enough to pin-point to the
7210 * start pfn and tick off bits one-by-one until it becomes
7211 * too coarse to separate the current node from the last.
7213 mask = ~((1 << __ffs(start)) - 1);
7214 while (mask && last_end <= (start & (mask << 1)))
7217 /* accumulate all internode masks */
7221 /* convert mask to number of pages */
7222 return ~accl_mask + 1;
7226 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7228 * Return: the minimum PFN based on information provided via
7229 * memblock_set_node().
7231 unsigned long __init find_min_pfn_with_active_regions(void)
7233 return PHYS_PFN(memblock_start_of_DRAM());
7237 * early_calculate_totalpages()
7238 * Sum pages in active regions for movable zone.
7239 * Populate N_MEMORY for calculating usable_nodes.
7241 static unsigned long __init early_calculate_totalpages(void)
7243 unsigned long totalpages = 0;
7244 unsigned long start_pfn, end_pfn;
7247 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7248 unsigned long pages = end_pfn - start_pfn;
7250 totalpages += pages;
7252 node_set_state(nid, N_MEMORY);
7258 * Find the PFN the Movable zone begins in each node. Kernel memory
7259 * is spread evenly between nodes as long as the nodes have enough
7260 * memory. When they don't, some nodes will have more kernelcore than
7263 static void __init find_zone_movable_pfns_for_nodes(void)
7266 unsigned long usable_startpfn;
7267 unsigned long kernelcore_node, kernelcore_remaining;
7268 /* save the state before borrow the nodemask */
7269 nodemask_t saved_node_state = node_states[N_MEMORY];
7270 unsigned long totalpages = early_calculate_totalpages();
7271 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
7272 struct memblock_region *r;
7274 /* Need to find movable_zone earlier when movable_node is specified. */
7275 find_usable_zone_for_movable();
7278 * If movable_node is specified, ignore kernelcore and movablecore
7281 if (movable_node_is_enabled()) {
7282 for_each_mem_region(r) {
7283 if (!memblock_is_hotpluggable(r))
7286 nid = memblock_get_region_node(r);
7288 usable_startpfn = PFN_DOWN(r->base);
7289 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7290 min(usable_startpfn, zone_movable_pfn[nid]) :
7298 * If kernelcore=mirror is specified, ignore movablecore option
7300 if (mirrored_kernelcore) {
7301 bool mem_below_4gb_not_mirrored = false;
7303 for_each_mem_region(r) {
7304 if (memblock_is_mirror(r))
7307 nid = memblock_get_region_node(r);
7309 usable_startpfn = memblock_region_memory_base_pfn(r);
7311 if (usable_startpfn < 0x100000) {
7312 mem_below_4gb_not_mirrored = true;
7316 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
7317 min(usable_startpfn, zone_movable_pfn[nid]) :
7321 if (mem_below_4gb_not_mirrored)
7322 pr_warn("This configuration results in unmirrored kernel memory.\n");
7328 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7329 * amount of necessary memory.
7331 if (required_kernelcore_percent)
7332 required_kernelcore = (totalpages * 100 * required_kernelcore_percent) /
7334 if (required_movablecore_percent)
7335 required_movablecore = (totalpages * 100 * required_movablecore_percent) /
7339 * If movablecore= was specified, calculate what size of
7340 * kernelcore that corresponds so that memory usable for
7341 * any allocation type is evenly spread. If both kernelcore
7342 * and movablecore are specified, then the value of kernelcore
7343 * will be used for required_kernelcore if it's greater than
7344 * what movablecore would have allowed.
7346 if (required_movablecore) {
7347 unsigned long corepages;
7350 * Round-up so that ZONE_MOVABLE is at least as large as what
7351 * was requested by the user
7353 required_movablecore =
7354 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
7355 required_movablecore = min(totalpages, required_movablecore);
7356 corepages = totalpages - required_movablecore;
7358 required_kernelcore = max(required_kernelcore, corepages);
7362 * If kernelcore was not specified or kernelcore size is larger
7363 * than totalpages, there is no ZONE_MOVABLE.
7365 if (!required_kernelcore || required_kernelcore >= totalpages)
7368 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7369 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
7372 /* Spread kernelcore memory as evenly as possible throughout nodes */
7373 kernelcore_node = required_kernelcore / usable_nodes;
7374 for_each_node_state(nid, N_MEMORY) {
7375 unsigned long start_pfn, end_pfn;
7378 * Recalculate kernelcore_node if the division per node
7379 * now exceeds what is necessary to satisfy the requested
7380 * amount of memory for the kernel
7382 if (required_kernelcore < kernelcore_node)
7383 kernelcore_node = required_kernelcore / usable_nodes;
7386 * As the map is walked, we track how much memory is usable
7387 * by the kernel using kernelcore_remaining. When it is
7388 * 0, the rest of the node is usable by ZONE_MOVABLE
7390 kernelcore_remaining = kernelcore_node;
7392 /* Go through each range of PFNs within this node */
7393 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
7394 unsigned long size_pages;
7396 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
7397 if (start_pfn >= end_pfn)
7400 /* Account for what is only usable for kernelcore */
7401 if (start_pfn < usable_startpfn) {
7402 unsigned long kernel_pages;
7403 kernel_pages = min(end_pfn, usable_startpfn)
7406 kernelcore_remaining -= min(kernel_pages,
7407 kernelcore_remaining);
7408 required_kernelcore -= min(kernel_pages,
7409 required_kernelcore);
7411 /* Continue if range is now fully accounted */
7412 if (end_pfn <= usable_startpfn) {
7415 * Push zone_movable_pfn to the end so
7416 * that if we have to rebalance
7417 * kernelcore across nodes, we will
7418 * not double account here
7420 zone_movable_pfn[nid] = end_pfn;
7423 start_pfn = usable_startpfn;
7427 * The usable PFN range for ZONE_MOVABLE is from
7428 * start_pfn->end_pfn. Calculate size_pages as the
7429 * number of pages used as kernelcore
7431 size_pages = end_pfn - start_pfn;
7432 if (size_pages > kernelcore_remaining)
7433 size_pages = kernelcore_remaining;
7434 zone_movable_pfn[nid] = start_pfn + size_pages;
7437 * Some kernelcore has been met, update counts and
7438 * break if the kernelcore for this node has been
7441 required_kernelcore -= min(required_kernelcore,
7443 kernelcore_remaining -= size_pages;
7444 if (!kernelcore_remaining)
7450 * If there is still required_kernelcore, we do another pass with one
7451 * less node in the count. This will push zone_movable_pfn[nid] further
7452 * along on the nodes that still have memory until kernelcore is
7456 if (usable_nodes && required_kernelcore > usable_nodes)
7460 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7461 for (nid = 0; nid < MAX_NUMNODES; nid++)
7462 zone_movable_pfn[nid] =
7463 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
7466 /* restore the node_state */
7467 node_states[N_MEMORY] = saved_node_state;
7470 /* Any regular or high memory on that node ? */
7471 static void check_for_memory(pg_data_t *pgdat, int nid)
7473 enum zone_type zone_type;
7475 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
7476 struct zone *zone = &pgdat->node_zones[zone_type];
7477 if (populated_zone(zone)) {
7478 if (IS_ENABLED(CONFIG_HIGHMEM))
7479 node_set_state(nid, N_HIGH_MEMORY);
7480 if (zone_type <= ZONE_NORMAL)
7481 node_set_state(nid, N_NORMAL_MEMORY);
7488 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7489 * such cases we allow max_zone_pfn sorted in the descending order
7491 bool __weak arch_has_descending_max_zone_pfns(void)
7497 * free_area_init - Initialise all pg_data_t and zone data
7498 * @max_zone_pfn: an array of max PFNs for each zone
7500 * This will call free_area_init_node() for each active node in the system.
7501 * Using the page ranges provided by memblock_set_node(), the size of each
7502 * zone in each node and their holes is calculated. If the maximum PFN
7503 * between two adjacent zones match, it is assumed that the zone is empty.
7504 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7505 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7506 * starts where the previous one ended. For example, ZONE_DMA32 starts
7507 * at arch_max_dma_pfn.
7509 void __init free_area_init(unsigned long *max_zone_pfn)
7511 unsigned long start_pfn, end_pfn;
7515 /* Record where the zone boundaries are */
7516 memset(arch_zone_lowest_possible_pfn, 0,
7517 sizeof(arch_zone_lowest_possible_pfn));
7518 memset(arch_zone_highest_possible_pfn, 0,
7519 sizeof(arch_zone_highest_possible_pfn));
7521 start_pfn = find_min_pfn_with_active_regions();
7522 descending = arch_has_descending_max_zone_pfns();
7524 for (i = 0; i < MAX_NR_ZONES; i++) {
7526 zone = MAX_NR_ZONES - i - 1;
7530 if (zone == ZONE_MOVABLE)
7533 end_pfn = max(max_zone_pfn[zone], start_pfn);
7534 arch_zone_lowest_possible_pfn[zone] = start_pfn;
7535 arch_zone_highest_possible_pfn[zone] = end_pfn;
7537 start_pfn = end_pfn;
7540 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7541 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
7542 find_zone_movable_pfns_for_nodes();
7544 /* Print out the zone ranges */
7545 pr_info("Zone ranges:\n");
7546 for (i = 0; i < MAX_NR_ZONES; i++) {
7547 if (i == ZONE_MOVABLE)
7549 pr_info(" %-8s ", zone_names[i]);
7550 if (arch_zone_lowest_possible_pfn[i] ==
7551 arch_zone_highest_possible_pfn[i])
7554 pr_cont("[mem %#018Lx-%#018Lx]\n",
7555 (u64)arch_zone_lowest_possible_pfn[i]
7557 ((u64)arch_zone_highest_possible_pfn[i]
7558 << PAGE_SHIFT) - 1);
7561 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7562 pr_info("Movable zone start for each node\n");
7563 for (i = 0; i < MAX_NUMNODES; i++) {
7564 if (zone_movable_pfn[i])
7565 pr_info(" Node %d: %#018Lx\n", i,
7566 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
7570 * Print out the early node map, and initialize the
7571 * subsection-map relative to active online memory ranges to
7572 * enable future "sub-section" extensions of the memory map.
7574 pr_info("Early memory node ranges\n");
7575 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
7576 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
7577 (u64)start_pfn << PAGE_SHIFT,
7578 ((u64)end_pfn << PAGE_SHIFT) - 1);
7579 subsection_map_init(start_pfn, end_pfn - start_pfn);
7582 /* Initialise every node */
7583 mminit_verify_pageflags_layout();
7584 setup_nr_node_ids();
7585 init_unavailable_mem();
7586 for_each_online_node(nid) {
7587 pg_data_t *pgdat = NODE_DATA(nid);
7588 free_area_init_node(nid);
7590 /* Any memory on that node */
7591 if (pgdat->node_present_pages)
7592 node_set_state(nid, N_MEMORY);
7593 check_for_memory(pgdat, nid);
7597 static int __init cmdline_parse_core(char *p, unsigned long *core,
7598 unsigned long *percent)
7600 unsigned long long coremem;
7606 /* Value may be a percentage of total memory, otherwise bytes */
7607 coremem = simple_strtoull(p, &endptr, 0);
7608 if (*endptr == '%') {
7609 /* Paranoid check for percent values greater than 100 */
7610 WARN_ON(coremem > 100);
7614 coremem = memparse(p, &p);
7615 /* Paranoid check that UL is enough for the coremem value */
7616 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
7618 *core = coremem >> PAGE_SHIFT;
7625 * kernelcore=size sets the amount of memory for use for allocations that
7626 * cannot be reclaimed or migrated.
7628 static int __init cmdline_parse_kernelcore(char *p)
7630 /* parse kernelcore=mirror */
7631 if (parse_option_str(p, "mirror")) {
7632 mirrored_kernelcore = true;
7636 return cmdline_parse_core(p, &required_kernelcore,
7637 &required_kernelcore_percent);
7641 * movablecore=size sets the amount of memory for use for allocations that
7642 * can be reclaimed or migrated.
7644 static int __init cmdline_parse_movablecore(char *p)
7646 return cmdline_parse_core(p, &required_movablecore,
7647 &required_movablecore_percent);
7650 early_param("kernelcore", cmdline_parse_kernelcore);
7651 early_param("movablecore", cmdline_parse_movablecore);
7653 void adjust_managed_page_count(struct page *page, long count)
7655 atomic_long_add(count, &page_zone(page)->managed_pages);
7656 totalram_pages_add(count);
7657 #ifdef CONFIG_HIGHMEM
7658 if (PageHighMem(page))
7659 totalhigh_pages_add(count);
7662 EXPORT_SYMBOL(adjust_managed_page_count);
7664 unsigned long free_reserved_area(void *start, void *end, int poison, const char *s)
7667 unsigned long pages = 0;
7669 start = (void *)PAGE_ALIGN((unsigned long)start);
7670 end = (void *)((unsigned long)end & PAGE_MASK);
7671 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
7672 struct page *page = virt_to_page(pos);
7673 void *direct_map_addr;
7676 * 'direct_map_addr' might be different from 'pos'
7677 * because some architectures' virt_to_page()
7678 * work with aliases. Getting the direct map
7679 * address ensures that we get a _writeable_
7680 * alias for the memset().
7682 direct_map_addr = page_address(page);
7684 * Perform a kasan-unchecked memset() since this memory
7685 * has not been initialized.
7687 direct_map_addr = kasan_reset_tag(direct_map_addr);
7688 if ((unsigned int)poison <= 0xFF)
7689 memset(direct_map_addr, poison, PAGE_SIZE);
7691 free_reserved_page(page);
7695 pr_info("Freeing %s memory: %ldK\n",
7696 s, pages << (PAGE_SHIFT - 10));
7701 #ifdef CONFIG_HIGHMEM
7702 void free_highmem_page(struct page *page)
7704 __free_reserved_page(page);
7705 totalram_pages_inc();
7706 atomic_long_inc(&page_zone(page)->managed_pages);
7707 totalhigh_pages_inc();
7712 void __init mem_init_print_info(const char *str)
7714 unsigned long physpages, codesize, datasize, rosize, bss_size;
7715 unsigned long init_code_size, init_data_size;
7717 physpages = get_num_physpages();
7718 codesize = _etext - _stext;
7719 datasize = _edata - _sdata;
7720 rosize = __end_rodata - __start_rodata;
7721 bss_size = __bss_stop - __bss_start;
7722 init_data_size = __init_end - __init_begin;
7723 init_code_size = _einittext - _sinittext;
7726 * Detect special cases and adjust section sizes accordingly:
7727 * 1) .init.* may be embedded into .data sections
7728 * 2) .init.text.* may be out of [__init_begin, __init_end],
7729 * please refer to arch/tile/kernel/vmlinux.lds.S.
7730 * 3) .rodata.* may be embedded into .text or .data sections.
7732 #define adj_init_size(start, end, size, pos, adj) \
7734 if (start <= pos && pos < end && size > adj) \
7738 adj_init_size(__init_begin, __init_end, init_data_size,
7739 _sinittext, init_code_size);
7740 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
7741 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
7742 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
7743 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
7745 #undef adj_init_size
7747 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7748 #ifdef CONFIG_HIGHMEM
7752 nr_free_pages() << (PAGE_SHIFT - 10),
7753 physpages << (PAGE_SHIFT - 10),
7754 codesize >> 10, datasize >> 10, rosize >> 10,
7755 (init_data_size + init_code_size) >> 10, bss_size >> 10,
7756 (physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10),
7757 totalcma_pages << (PAGE_SHIFT - 10),
7758 #ifdef CONFIG_HIGHMEM
7759 totalhigh_pages() << (PAGE_SHIFT - 10),
7761 str ? ", " : "", str ? str : "");
7765 * set_dma_reserve - set the specified number of pages reserved in the first zone
7766 * @new_dma_reserve: The number of pages to mark reserved
7768 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7769 * In the DMA zone, a significant percentage may be consumed by kernel image
7770 * and other unfreeable allocations which can skew the watermarks badly. This
7771 * function may optionally be used to account for unfreeable pages in the
7772 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7773 * smaller per-cpu batchsize.
7775 void __init set_dma_reserve(unsigned long new_dma_reserve)
7777 dma_reserve = new_dma_reserve;
7780 static int page_alloc_cpu_dead(unsigned int cpu)
7783 lru_add_drain_cpu(cpu);
7787 * Spill the event counters of the dead processor
7788 * into the current processors event counters.
7789 * This artificially elevates the count of the current
7792 vm_events_fold_cpu(cpu);
7795 * Zero the differential counters of the dead processor
7796 * so that the vm statistics are consistent.
7798 * This is only okay since the processor is dead and cannot
7799 * race with what we are doing.
7801 cpu_vm_stats_fold(cpu);
7806 int hashdist = HASHDIST_DEFAULT;
7808 static int __init set_hashdist(char *str)
7812 hashdist = simple_strtoul(str, &str, 0);
7815 __setup("hashdist=", set_hashdist);
7818 void __init page_alloc_init(void)
7823 if (num_node_state(N_MEMORY) == 1)
7827 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD,
7828 "mm/page_alloc:dead", NULL,
7829 page_alloc_cpu_dead);
7834 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7835 * or min_free_kbytes changes.
7837 static void calculate_totalreserve_pages(void)
7839 struct pglist_data *pgdat;
7840 unsigned long reserve_pages = 0;
7841 enum zone_type i, j;
7843 for_each_online_pgdat(pgdat) {
7845 pgdat->totalreserve_pages = 0;
7847 for (i = 0; i < MAX_NR_ZONES; i++) {
7848 struct zone *zone = pgdat->node_zones + i;
7850 unsigned long managed_pages = zone_managed_pages(zone);
7852 /* Find valid and maximum lowmem_reserve in the zone */
7853 for (j = i; j < MAX_NR_ZONES; j++) {
7854 if (zone->lowmem_reserve[j] > max)
7855 max = zone->lowmem_reserve[j];
7858 /* we treat the high watermark as reserved pages. */
7859 max += high_wmark_pages(zone);
7861 if (max > managed_pages)
7862 max = managed_pages;
7864 pgdat->totalreserve_pages += max;
7866 reserve_pages += max;
7869 totalreserve_pages = reserve_pages;
7873 * setup_per_zone_lowmem_reserve - called whenever
7874 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7875 * has a correct pages reserved value, so an adequate number of
7876 * pages are left in the zone after a successful __alloc_pages().
7878 static void setup_per_zone_lowmem_reserve(void)
7880 struct pglist_data *pgdat;
7881 enum zone_type i, j;
7883 for_each_online_pgdat(pgdat) {
7884 for (i = 0; i < MAX_NR_ZONES - 1; i++) {
7885 struct zone *zone = &pgdat->node_zones[i];
7886 int ratio = sysctl_lowmem_reserve_ratio[i];
7887 bool clear = !ratio || !zone_managed_pages(zone);
7888 unsigned long managed_pages = 0;
7890 for (j = i + 1; j < MAX_NR_ZONES; j++) {
7892 zone->lowmem_reserve[j] = 0;
7894 struct zone *upper_zone = &pgdat->node_zones[j];
7896 managed_pages += zone_managed_pages(upper_zone);
7897 zone->lowmem_reserve[j] = managed_pages / ratio;
7903 /* update totalreserve_pages */
7904 calculate_totalreserve_pages();
7907 static void __setup_per_zone_wmarks(void)
7909 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
7910 unsigned long lowmem_pages = 0;
7912 unsigned long flags;
7914 /* Calculate total number of !ZONE_HIGHMEM pages */
7915 for_each_zone(zone) {
7916 if (!is_highmem(zone))
7917 lowmem_pages += zone_managed_pages(zone);
7920 for_each_zone(zone) {
7923 spin_lock_irqsave(&zone->lock, flags);
7924 tmp = (u64)pages_min * zone_managed_pages(zone);
7925 do_div(tmp, lowmem_pages);
7926 if (is_highmem(zone)) {
7928 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7929 * need highmem pages, so cap pages_min to a small
7932 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7933 * deltas control async page reclaim, and so should
7934 * not be capped for highmem.
7936 unsigned long min_pages;
7938 min_pages = zone_managed_pages(zone) / 1024;
7939 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
7940 zone->_watermark[WMARK_MIN] = min_pages;
7943 * If it's a lowmem zone, reserve a number of pages
7944 * proportionate to the zone's size.
7946 zone->_watermark[WMARK_MIN] = tmp;
7950 * Set the kswapd watermarks distance according to the
7951 * scale factor in proportion to available memory, but
7952 * ensure a minimum size on small systems.
7954 tmp = max_t(u64, tmp >> 2,
7955 mult_frac(zone_managed_pages(zone),
7956 watermark_scale_factor, 10000));
7958 zone->watermark_boost = 0;
7959 zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
7960 zone->_watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
7962 spin_unlock_irqrestore(&zone->lock, flags);
7965 /* update totalreserve_pages */
7966 calculate_totalreserve_pages();
7970 * setup_per_zone_wmarks - called when min_free_kbytes changes
7971 * or when memory is hot-{added|removed}
7973 * Ensures that the watermark[min,low,high] values for each zone are set
7974 * correctly with respect to min_free_kbytes.
7976 void setup_per_zone_wmarks(void)
7978 static DEFINE_SPINLOCK(lock);
7981 __setup_per_zone_wmarks();
7986 * Initialise min_free_kbytes.
7988 * For small machines we want it small (128k min). For large machines
7989 * we want it large (256MB max). But it is not linear, because network
7990 * bandwidth does not increase linearly with machine size. We use
7992 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7993 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
8009 int __meminit init_per_zone_wmark_min(void)
8011 unsigned long lowmem_kbytes;
8012 int new_min_free_kbytes;
8014 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
8015 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
8017 if (new_min_free_kbytes > user_min_free_kbytes) {
8018 min_free_kbytes = new_min_free_kbytes;
8019 if (min_free_kbytes < 128)
8020 min_free_kbytes = 128;
8021 if (min_free_kbytes > 262144)
8022 min_free_kbytes = 262144;
8024 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
8025 new_min_free_kbytes, user_min_free_kbytes);
8027 setup_per_zone_wmarks();
8028 refresh_zone_stat_thresholds();
8029 setup_per_zone_lowmem_reserve();
8032 setup_min_unmapped_ratio();
8033 setup_min_slab_ratio();
8036 khugepaged_min_free_kbytes_update();
8040 postcore_initcall(init_per_zone_wmark_min)
8043 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
8044 * that we can call two helper functions whenever min_free_kbytes
8047 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
8048 void *buffer, size_t *length, loff_t *ppos)
8052 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8057 user_min_free_kbytes = min_free_kbytes;
8058 setup_per_zone_wmarks();
8063 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
8064 void *buffer, size_t *length, loff_t *ppos)
8068 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8073 setup_per_zone_wmarks();
8079 static void setup_min_unmapped_ratio(void)
8084 for_each_online_pgdat(pgdat)
8085 pgdat->min_unmapped_pages = 0;
8088 zone->zone_pgdat->min_unmapped_pages += (zone_managed_pages(zone) *
8089 sysctl_min_unmapped_ratio) / 100;
8093 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
8094 void *buffer, size_t *length, loff_t *ppos)
8098 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8102 setup_min_unmapped_ratio();
8107 static void setup_min_slab_ratio(void)
8112 for_each_online_pgdat(pgdat)
8113 pgdat->min_slab_pages = 0;
8116 zone->zone_pgdat->min_slab_pages += (zone_managed_pages(zone) *
8117 sysctl_min_slab_ratio) / 100;
8120 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
8121 void *buffer, size_t *length, loff_t *ppos)
8125 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
8129 setup_min_slab_ratio();
8136 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8137 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8138 * whenever sysctl_lowmem_reserve_ratio changes.
8140 * The reserve ratio obviously has absolutely no relation with the
8141 * minimum watermarks. The lowmem reserve ratio can only make sense
8142 * if in function of the boot time zone sizes.
8144 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
8145 void *buffer, size_t *length, loff_t *ppos)
8149 proc_dointvec_minmax(table, write, buffer, length, ppos);
8151 for (i = 0; i < MAX_NR_ZONES; i++) {
8152 if (sysctl_lowmem_reserve_ratio[i] < 1)
8153 sysctl_lowmem_reserve_ratio[i] = 0;
8156 setup_per_zone_lowmem_reserve();
8161 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8162 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8163 * pagelist can have before it gets flushed back to buddy allocator.
8165 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
8166 void *buffer, size_t *length, loff_t *ppos)
8169 int old_percpu_pagelist_fraction;
8172 mutex_lock(&pcp_batch_high_lock);
8173 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
8175 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
8176 if (!write || ret < 0)
8179 /* Sanity checking to avoid pcp imbalance */
8180 if (percpu_pagelist_fraction &&
8181 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
8182 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
8188 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
8191 for_each_populated_zone(zone)
8192 zone_set_pageset_high_and_batch(zone);
8194 mutex_unlock(&pcp_batch_high_lock);
8198 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8200 * Returns the number of pages that arch has reserved but
8201 * is not known to alloc_large_system_hash().
8203 static unsigned long __init arch_reserved_kernel_pages(void)
8210 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8211 * machines. As memory size is increased the scale is also increased but at
8212 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8213 * quadruples the scale is increased by one, which means the size of hash table
8214 * only doubles, instead of quadrupling as well.
8215 * Because 32-bit systems cannot have large physical memory, where this scaling
8216 * makes sense, it is disabled on such platforms.
8218 #if __BITS_PER_LONG > 32
8219 #define ADAPT_SCALE_BASE (64ul << 30)
8220 #define ADAPT_SCALE_SHIFT 2
8221 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8225 * allocate a large system hash table from bootmem
8226 * - it is assumed that the hash table must contain an exact power-of-2
8227 * quantity of entries
8228 * - limit is the number of hash buckets, not the total allocation size
8230 void *__init alloc_large_system_hash(const char *tablename,
8231 unsigned long bucketsize,
8232 unsigned long numentries,
8235 unsigned int *_hash_shift,
8236 unsigned int *_hash_mask,
8237 unsigned long low_limit,
8238 unsigned long high_limit)
8240 unsigned long long max = high_limit;
8241 unsigned long log2qty, size;
8246 /* allow the kernel cmdline to have a say */
8248 /* round applicable memory size up to nearest megabyte */
8249 numentries = nr_kernel_pages;
8250 numentries -= arch_reserved_kernel_pages();
8252 /* It isn't necessary when PAGE_SIZE >= 1MB */
8253 if (PAGE_SHIFT < 20)
8254 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
8256 #if __BITS_PER_LONG > 32
8258 unsigned long adapt;
8260 for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries;
8261 adapt <<= ADAPT_SCALE_SHIFT)
8266 /* limit to 1 bucket per 2^scale bytes of low memory */
8267 if (scale > PAGE_SHIFT)
8268 numentries >>= (scale - PAGE_SHIFT);
8270 numentries <<= (PAGE_SHIFT - scale);
8272 /* Make sure we've got at least a 0-order allocation.. */
8273 if (unlikely(flags & HASH_SMALL)) {
8274 /* Makes no sense without HASH_EARLY */
8275 WARN_ON(!(flags & HASH_EARLY));
8276 if (!(numentries >> *_hash_shift)) {
8277 numentries = 1UL << *_hash_shift;
8278 BUG_ON(!numentries);
8280 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
8281 numentries = PAGE_SIZE / bucketsize;
8283 numentries = roundup_pow_of_two(numentries);
8285 /* limit allocation size to 1/16 total memory by default */
8287 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
8288 do_div(max, bucketsize);
8290 max = min(max, 0x80000000ULL);
8292 if (numentries < low_limit)
8293 numentries = low_limit;
8294 if (numentries > max)
8297 log2qty = ilog2(numentries);
8299 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
8302 size = bucketsize << log2qty;
8303 if (flags & HASH_EARLY) {
8304 if (flags & HASH_ZERO)
8305 table = memblock_alloc(size, SMP_CACHE_BYTES);
8307 table = memblock_alloc_raw(size,
8309 } else if (get_order(size) >= MAX_ORDER || hashdist) {
8310 table = __vmalloc(size, gfp_flags);
8314 * If bucketsize is not a power-of-two, we may free
8315 * some pages at the end of hash table which
8316 * alloc_pages_exact() automatically does
8318 table = alloc_pages_exact(size, gfp_flags);
8319 kmemleak_alloc(table, size, 1, gfp_flags);
8321 } while (!table && size > PAGE_SIZE && --log2qty);
8324 panic("Failed to allocate %s hash table\n", tablename);
8326 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8327 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
8328 virt ? "vmalloc" : "linear");
8331 *_hash_shift = log2qty;
8333 *_hash_mask = (1 << log2qty) - 1;
8339 * This function checks whether pageblock includes unmovable pages or not.
8341 * PageLRU check without isolation or lru_lock could race so that
8342 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8343 * check without lock_page also may miss some movable non-lru pages at
8344 * race condition. So you can't expect this function should be exact.
8346 * Returns a page without holding a reference. If the caller wants to
8347 * dereference that page (e.g., dumping), it has to make sure that it
8348 * cannot get removed (e.g., via memory unplug) concurrently.
8351 struct page *has_unmovable_pages(struct zone *zone, struct page *page,
8352 int migratetype, int flags)
8354 unsigned long iter = 0;
8355 unsigned long pfn = page_to_pfn(page);
8356 unsigned long offset = pfn % pageblock_nr_pages;
8358 if (is_migrate_cma_page(page)) {
8360 * CMA allocations (alloc_contig_range) really need to mark
8361 * isolate CMA pageblocks even when they are not movable in fact
8362 * so consider them movable here.
8364 if (is_migrate_cma(migratetype))
8370 for (; iter < pageblock_nr_pages - offset; iter++) {
8371 if (!pfn_valid_within(pfn + iter))
8374 page = pfn_to_page(pfn + iter);
8377 * Both, bootmem allocations and memory holes are marked
8378 * PG_reserved and are unmovable. We can even have unmovable
8379 * allocations inside ZONE_MOVABLE, for example when
8380 * specifying "movablecore".
8382 if (PageReserved(page))
8386 * If the zone is movable and we have ruled out all reserved
8387 * pages then it should be reasonably safe to assume the rest
8390 if (zone_idx(zone) == ZONE_MOVABLE)
8394 * Hugepages are not in LRU lists, but they're movable.
8395 * THPs are on the LRU, but need to be counted as #small pages.
8396 * We need not scan over tail pages because we don't
8397 * handle each tail page individually in migration.
8399 if (PageHuge(page) || PageTransCompound(page)) {
8400 struct page *head = compound_head(page);
8401 unsigned int skip_pages;
8403 if (PageHuge(page)) {
8404 if (!hugepage_migration_supported(page_hstate(head)))
8406 } else if (!PageLRU(head) && !__PageMovable(head)) {
8410 skip_pages = compound_nr(head) - (page - head);
8411 iter += skip_pages - 1;
8416 * We can't use page_count without pin a page
8417 * because another CPU can free compound page.
8418 * This check already skips compound tails of THP
8419 * because their page->_refcount is zero at all time.
8421 if (!page_ref_count(page)) {
8422 if (PageBuddy(page))
8423 iter += (1 << buddy_order(page)) - 1;
8428 * The HWPoisoned page may be not in buddy system, and
8429 * page_count() is not 0.
8431 if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
8435 * We treat all PageOffline() pages as movable when offlining
8436 * to give drivers a chance to decrement their reference count
8437 * in MEM_GOING_OFFLINE in order to indicate that these pages
8438 * can be offlined as there are no direct references anymore.
8439 * For actually unmovable PageOffline() where the driver does
8440 * not support this, we will fail later when trying to actually
8441 * move these pages that still have a reference count > 0.
8442 * (false negatives in this function only)
8444 if ((flags & MEMORY_OFFLINE) && PageOffline(page))
8447 if (__PageMovable(page) || PageLRU(page))
8451 * If there are RECLAIMABLE pages, we need to check
8452 * it. But now, memory offline itself doesn't call
8453 * shrink_node_slabs() and it still to be fixed.
8460 #ifdef CONFIG_CONTIG_ALLOC
8461 static unsigned long pfn_max_align_down(unsigned long pfn)
8463 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
8464 pageblock_nr_pages) - 1);
8467 static unsigned long pfn_max_align_up(unsigned long pfn)
8469 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
8470 pageblock_nr_pages));
8473 /* [start, end) must belong to a single zone. */
8474 static int __alloc_contig_migrate_range(struct compact_control *cc,
8475 unsigned long start, unsigned long end)
8477 /* This function is based on compact_zone() from compaction.c. */
8478 unsigned int nr_reclaimed;
8479 unsigned long pfn = start;
8480 unsigned int tries = 0;
8482 struct migration_target_control mtc = {
8483 .nid = zone_to_nid(cc->zone),
8484 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
8489 while (pfn < end || !list_empty(&cc->migratepages)) {
8490 if (fatal_signal_pending(current)) {
8495 if (list_empty(&cc->migratepages)) {
8496 cc->nr_migratepages = 0;
8497 pfn = isolate_migratepages_range(cc, pfn, end);
8503 } else if (++tries == 5) {
8504 ret = ret < 0 ? ret : -EBUSY;
8508 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
8510 cc->nr_migratepages -= nr_reclaimed;
8512 ret = migrate_pages(&cc->migratepages, alloc_migration_target,
8513 NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE);
8516 putback_movable_pages(&cc->migratepages);
8523 * alloc_contig_range() -- tries to allocate given range of pages
8524 * @start: start PFN to allocate
8525 * @end: one-past-the-last PFN to allocate
8526 * @migratetype: migratetype of the underlaying pageblocks (either
8527 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8528 * in range must have the same migratetype and it must
8529 * be either of the two.
8530 * @gfp_mask: GFP mask to use during compaction
8532 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8533 * aligned. The PFN range must belong to a single zone.
8535 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8536 * pageblocks in the range. Once isolated, the pageblocks should not
8537 * be modified by others.
8539 * Return: zero on success or negative error code. On success all
8540 * pages which PFN is in [start, end) are allocated for the caller and
8541 * need to be freed with free_contig_range().
8543 int alloc_contig_range(unsigned long start, unsigned long end,
8544 unsigned migratetype, gfp_t gfp_mask)
8546 unsigned long outer_start, outer_end;
8550 struct compact_control cc = {
8551 .nr_migratepages = 0,
8553 .zone = page_zone(pfn_to_page(start)),
8554 .mode = MIGRATE_SYNC,
8555 .ignore_skip_hint = true,
8556 .no_set_skip_hint = true,
8557 .gfp_mask = current_gfp_context(gfp_mask),
8558 .alloc_contig = true,
8560 INIT_LIST_HEAD(&cc.migratepages);
8563 * What we do here is we mark all pageblocks in range as
8564 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8565 * have different sizes, and due to the way page allocator
8566 * work, we align the range to biggest of the two pages so
8567 * that page allocator won't try to merge buddies from
8568 * different pageblocks and change MIGRATE_ISOLATE to some
8569 * other migration type.
8571 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8572 * migrate the pages from an unaligned range (ie. pages that
8573 * we are interested in). This will put all the pages in
8574 * range back to page allocator as MIGRATE_ISOLATE.
8576 * When this is done, we take the pages in range from page
8577 * allocator removing them from the buddy system. This way
8578 * page allocator will never consider using them.
8580 * This lets us mark the pageblocks back as
8581 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8582 * aligned range but not in the unaligned, original range are
8583 * put back to page allocator so that buddy can use them.
8586 ret = start_isolate_page_range(pfn_max_align_down(start),
8587 pfn_max_align_up(end), migratetype, 0);
8591 drain_all_pages(cc.zone);
8594 * In case of -EBUSY, we'd like to know which page causes problem.
8595 * So, just fall through. test_pages_isolated() has a tracepoint
8596 * which will report the busy page.
8598 * It is possible that busy pages could become available before
8599 * the call to test_pages_isolated, and the range will actually be
8600 * allocated. So, if we fall through be sure to clear ret so that
8601 * -EBUSY is not accidentally used or returned to caller.
8603 ret = __alloc_contig_migrate_range(&cc, start, end);
8604 if (ret && ret != -EBUSY)
8609 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8610 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8611 * more, all pages in [start, end) are free in page allocator.
8612 * What we are going to do is to allocate all pages from
8613 * [start, end) (that is remove them from page allocator).
8615 * The only problem is that pages at the beginning and at the
8616 * end of interesting range may be not aligned with pages that
8617 * page allocator holds, ie. they can be part of higher order
8618 * pages. Because of this, we reserve the bigger range and
8619 * once this is done free the pages we are not interested in.
8621 * We don't have to hold zone->lock here because the pages are
8622 * isolated thus they won't get removed from buddy.
8625 lru_add_drain_all();
8628 outer_start = start;
8629 while (!PageBuddy(pfn_to_page(outer_start))) {
8630 if (++order >= MAX_ORDER) {
8631 outer_start = start;
8634 outer_start &= ~0UL << order;
8637 if (outer_start != start) {
8638 order = buddy_order(pfn_to_page(outer_start));
8641 * outer_start page could be small order buddy page and
8642 * it doesn't include start page. Adjust outer_start
8643 * in this case to report failed page properly
8644 * on tracepoint in test_pages_isolated()
8646 if (outer_start + (1UL << order) <= start)
8647 outer_start = start;
8650 /* Make sure the range is really isolated. */
8651 if (test_pages_isolated(outer_start, end, 0)) {
8652 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8653 __func__, outer_start, end);
8658 /* Grab isolated pages from freelists. */
8659 outer_end = isolate_freepages_range(&cc, outer_start, end);
8665 /* Free head and tail (if any) */
8666 if (start != outer_start)
8667 free_contig_range(outer_start, start - outer_start);
8668 if (end != outer_end)
8669 free_contig_range(end, outer_end - end);
8672 undo_isolate_page_range(pfn_max_align_down(start),
8673 pfn_max_align_up(end), migratetype);
8676 EXPORT_SYMBOL(alloc_contig_range);
8678 static int __alloc_contig_pages(unsigned long start_pfn,
8679 unsigned long nr_pages, gfp_t gfp_mask)
8681 unsigned long end_pfn = start_pfn + nr_pages;
8683 return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
8687 static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
8688 unsigned long nr_pages)
8690 unsigned long i, end_pfn = start_pfn + nr_pages;
8693 for (i = start_pfn; i < end_pfn; i++) {
8694 page = pfn_to_online_page(i);
8698 if (page_zone(page) != z)
8701 if (PageReserved(page))
8704 if (page_count(page) > 0)
8713 static bool zone_spans_last_pfn(const struct zone *zone,
8714 unsigned long start_pfn, unsigned long nr_pages)
8716 unsigned long last_pfn = start_pfn + nr_pages - 1;
8718 return zone_spans_pfn(zone, last_pfn);
8722 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8723 * @nr_pages: Number of contiguous pages to allocate
8724 * @gfp_mask: GFP mask to limit search and used during compaction
8726 * @nodemask: Mask for other possible nodes
8728 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8729 * on an applicable zonelist to find a contiguous pfn range which can then be
8730 * tried for allocation with alloc_contig_range(). This routine is intended
8731 * for allocation requests which can not be fulfilled with the buddy allocator.
8733 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8734 * power of two then the alignment is guaranteed to be to the given nr_pages
8735 * (e.g. 1GB request would be aligned to 1GB).
8737 * Allocated pages can be freed with free_contig_range() or by manually calling
8738 * __free_page() on each allocated page.
8740 * Return: pointer to contiguous pages on success, or NULL if not successful.
8742 struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
8743 int nid, nodemask_t *nodemask)
8745 unsigned long ret, pfn, flags;
8746 struct zonelist *zonelist;
8750 zonelist = node_zonelist(nid, gfp_mask);
8751 for_each_zone_zonelist_nodemask(zone, z, zonelist,
8752 gfp_zone(gfp_mask), nodemask) {
8753 spin_lock_irqsave(&zone->lock, flags);
8755 pfn = ALIGN(zone->zone_start_pfn, nr_pages);
8756 while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
8757 if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
8759 * We release the zone lock here because
8760 * alloc_contig_range() will also lock the zone
8761 * at some point. If there's an allocation
8762 * spinning on this lock, it may win the race
8763 * and cause alloc_contig_range() to fail...
8765 spin_unlock_irqrestore(&zone->lock, flags);
8766 ret = __alloc_contig_pages(pfn, nr_pages,
8769 return pfn_to_page(pfn);
8770 spin_lock_irqsave(&zone->lock, flags);
8774 spin_unlock_irqrestore(&zone->lock, flags);
8778 #endif /* CONFIG_CONTIG_ALLOC */
8780 void free_contig_range(unsigned long pfn, unsigned int nr_pages)
8782 unsigned int count = 0;
8784 for (; nr_pages--; pfn++) {
8785 struct page *page = pfn_to_page(pfn);
8787 count += page_count(page) != 1;
8790 WARN(count != 0, "%d pages are still in use!\n", count);
8792 EXPORT_SYMBOL(free_contig_range);
8795 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8796 * page high values need to be recalulated.
8798 void __meminit zone_pcp_update(struct zone *zone)
8800 mutex_lock(&pcp_batch_high_lock);
8801 zone_set_pageset_high_and_batch(zone);
8802 mutex_unlock(&pcp_batch_high_lock);
8806 * Effectively disable pcplists for the zone by setting the high limit to 0
8807 * and draining all cpus. A concurrent page freeing on another CPU that's about
8808 * to put the page on pcplist will either finish before the drain and the page
8809 * will be drained, or observe the new high limit and skip the pcplist.
8811 * Must be paired with a call to zone_pcp_enable().
8813 void zone_pcp_disable(struct zone *zone)
8815 mutex_lock(&pcp_batch_high_lock);
8816 __zone_set_pageset_high_and_batch(zone, 0, 1);
8817 __drain_all_pages(zone, true);
8820 void zone_pcp_enable(struct zone *zone)
8822 __zone_set_pageset_high_and_batch(zone, zone->pageset_high, zone->pageset_batch);
8823 mutex_unlock(&pcp_batch_high_lock);
8826 void zone_pcp_reset(struct zone *zone)
8828 unsigned long flags;
8830 struct per_cpu_pageset *pset;
8832 /* avoid races with drain_pages() */
8833 local_irq_save(flags);
8834 if (zone->pageset != &boot_pageset) {
8835 for_each_online_cpu(cpu) {
8836 pset = per_cpu_ptr(zone->pageset, cpu);
8837 drain_zonestat(zone, pset);
8839 free_percpu(zone->pageset);
8840 zone->pageset = &boot_pageset;
8842 local_irq_restore(flags);
8845 #ifdef CONFIG_MEMORY_HOTREMOVE
8847 * All pages in the range must be in a single zone, must not contain holes,
8848 * must span full sections, and must be isolated before calling this function.
8850 void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
8852 unsigned long pfn = start_pfn;
8856 unsigned long flags;
8858 offline_mem_sections(pfn, end_pfn);
8859 zone = page_zone(pfn_to_page(pfn));
8860 spin_lock_irqsave(&zone->lock, flags);
8861 while (pfn < end_pfn) {
8862 page = pfn_to_page(pfn);
8864 * The HWPoisoned page may be not in buddy system, and
8865 * page_count() is not 0.
8867 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
8872 * At this point all remaining PageOffline() pages have a
8873 * reference count of 0 and can simply be skipped.
8875 if (PageOffline(page)) {
8876 BUG_ON(page_count(page));
8877 BUG_ON(PageBuddy(page));
8882 BUG_ON(page_count(page));
8883 BUG_ON(!PageBuddy(page));
8884 order = buddy_order(page);
8885 del_page_from_free_list(page, zone, order);
8886 pfn += (1 << order);
8888 spin_unlock_irqrestore(&zone->lock, flags);
8892 bool is_free_buddy_page(struct page *page)
8894 struct zone *zone = page_zone(page);
8895 unsigned long pfn = page_to_pfn(page);
8896 unsigned long flags;
8899 spin_lock_irqsave(&zone->lock, flags);
8900 for (order = 0; order < MAX_ORDER; order++) {
8901 struct page *page_head = page - (pfn & ((1 << order) - 1));
8903 if (PageBuddy(page_head) && buddy_order(page_head) >= order)
8906 spin_unlock_irqrestore(&zone->lock, flags);
8908 return order < MAX_ORDER;
8911 #ifdef CONFIG_MEMORY_FAILURE
8913 * Break down a higher-order page in sub-pages, and keep our target out of
8916 static void break_down_buddy_pages(struct zone *zone, struct page *page,
8917 struct page *target, int low, int high,
8920 unsigned long size = 1 << high;
8921 struct page *current_buddy, *next_page;
8923 while (high > low) {
8927 if (target >= &page[size]) {
8928 next_page = page + size;
8929 current_buddy = page;
8932 current_buddy = page + size;
8935 if (set_page_guard(zone, current_buddy, high, migratetype))
8938 if (current_buddy != target) {
8939 add_to_free_list(current_buddy, zone, high, migratetype);
8940 set_buddy_order(current_buddy, high);
8947 * Take a page that will be marked as poisoned off the buddy allocator.
8949 bool take_page_off_buddy(struct page *page)
8951 struct zone *zone = page_zone(page);
8952 unsigned long pfn = page_to_pfn(page);
8953 unsigned long flags;
8957 spin_lock_irqsave(&zone->lock, flags);
8958 for (order = 0; order < MAX_ORDER; order++) {
8959 struct page *page_head = page - (pfn & ((1 << order) - 1));
8960 int page_order = buddy_order(page_head);
8962 if (PageBuddy(page_head) && page_order >= order) {
8963 unsigned long pfn_head = page_to_pfn(page_head);
8964 int migratetype = get_pfnblock_migratetype(page_head,
8967 del_page_from_free_list(page_head, zone, page_order);
8968 break_down_buddy_pages(zone, page_head, page, 0,
8969 page_order, migratetype);
8973 if (page_count(page_head) > 0)
8976 spin_unlock_irqrestore(&zone->lock, flags);