2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kasan.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/topology.h>
36 #include <linux/sysctl.h>
37 #include <linux/cpu.h>
38 #include <linux/cpuset.h>
39 #include <linux/memory_hotplug.h>
40 #include <linux/nodemask.h>
41 #include <linux/vmalloc.h>
42 #include <linux/vmstat.h>
43 #include <linux/mempolicy.h>
44 #include <linux/memremap.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_ext.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <trace/events/oom.h>
57 #include <linux/prefetch.h>
58 #include <linux/mm_inline.h>
59 #include <linux/migrate.h>
60 #include <linux/hugetlb.h>
61 #include <linux/sched/rt.h>
62 #include <linux/sched/mm.h>
63 #include <linux/page_owner.h>
64 #include <linux/kthread.h>
65 #include <linux/memcontrol.h>
66 #include <linux/ftrace.h>
67 #include <linux/lockdep.h>
68 #include <linux/nmi.h>
69 #include <linux/khugepaged.h>
71 #include <asm/sections.h>
72 #include <asm/tlbflush.h>
73 #include <asm/div64.h>
76 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
77 static DEFINE_MUTEX(pcp_batch_high_lock);
78 #define MIN_PERCPU_PAGELIST_FRACTION (8)
80 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
81 DEFINE_PER_CPU(int, numa_node);
82 EXPORT_PER_CPU_SYMBOL(numa_node);
85 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key);
87 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
89 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
90 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
91 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
92 * defined in <linux/topology.h>.
94 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
95 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
96 int _node_numa_mem_[MAX_NUMNODES];
99 /* work_structs for global per-cpu drains */
100 DEFINE_MUTEX(pcpu_drain_mutex);
101 DEFINE_PER_CPU(struct work_struct, pcpu_drain);
103 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
104 volatile unsigned long latent_entropy __latent_entropy;
105 EXPORT_SYMBOL(latent_entropy);
109 * Array of node states.
111 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
112 [N_POSSIBLE] = NODE_MASK_ALL,
113 [N_ONLINE] = { { [0] = 1UL } },
115 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
116 #ifdef CONFIG_HIGHMEM
117 [N_HIGH_MEMORY] = { { [0] = 1UL } },
119 [N_MEMORY] = { { [0] = 1UL } },
120 [N_CPU] = { { [0] = 1UL } },
123 EXPORT_SYMBOL(node_states);
125 /* Protect totalram_pages and zone->managed_pages */
126 static DEFINE_SPINLOCK(managed_page_count_lock);
128 unsigned long totalram_pages __read_mostly;
129 unsigned long totalreserve_pages __read_mostly;
130 unsigned long totalcma_pages __read_mostly;
132 int percpu_pagelist_fraction;
133 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
136 * A cached value of the page's pageblock's migratetype, used when the page is
137 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
138 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
139 * Also the migratetype set in the page does not necessarily match the pcplist
140 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
141 * other index - this ensures that it will be put on the correct CMA freelist.
143 static inline int get_pcppage_migratetype(struct page *page)
148 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
150 page->index = migratetype;
153 #ifdef CONFIG_PM_SLEEP
155 * The following functions are used by the suspend/hibernate code to temporarily
156 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
157 * while devices are suspended. To avoid races with the suspend/hibernate code,
158 * they should always be called with system_transition_mutex held
159 * (gfp_allowed_mask also should only be modified with system_transition_mutex
160 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
161 * with that modification).
164 static gfp_t saved_gfp_mask;
166 void pm_restore_gfp_mask(void)
168 WARN_ON(!mutex_is_locked(&system_transition_mutex));
169 if (saved_gfp_mask) {
170 gfp_allowed_mask = saved_gfp_mask;
175 void pm_restrict_gfp_mask(void)
177 WARN_ON(!mutex_is_locked(&system_transition_mutex));
178 WARN_ON(saved_gfp_mask);
179 saved_gfp_mask = gfp_allowed_mask;
180 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
183 bool pm_suspended_storage(void)
185 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
189 #endif /* CONFIG_PM_SLEEP */
191 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
192 unsigned int pageblock_order __read_mostly;
195 static void __free_pages_ok(struct page *page, unsigned int order);
198 * results with 256, 32 in the lowmem_reserve sysctl:
199 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
200 * 1G machine -> (16M dma, 784M normal, 224M high)
201 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
202 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
203 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
205 * TBD: should special case ZONE_DMA32 machines here - in those we normally
206 * don't need any ZONE_NORMAL reservation
208 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
209 #ifdef CONFIG_ZONE_DMA
212 #ifdef CONFIG_ZONE_DMA32
216 #ifdef CONFIG_HIGHMEM
222 EXPORT_SYMBOL(totalram_pages);
224 static char * const zone_names[MAX_NR_ZONES] = {
225 #ifdef CONFIG_ZONE_DMA
228 #ifdef CONFIG_ZONE_DMA32
232 #ifdef CONFIG_HIGHMEM
236 #ifdef CONFIG_ZONE_DEVICE
241 char * const migratetype_names[MIGRATE_TYPES] = {
249 #ifdef CONFIG_MEMORY_ISOLATION
254 compound_page_dtor * const compound_page_dtors[] = {
257 #ifdef CONFIG_HUGETLB_PAGE
260 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
265 int min_free_kbytes = 1024;
266 int user_min_free_kbytes = -1;
267 int watermark_scale_factor = 10;
269 static unsigned long nr_kernel_pages __meminitdata;
270 static unsigned long nr_all_pages __meminitdata;
271 static unsigned long dma_reserve __meminitdata;
273 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
274 static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __meminitdata;
275 static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __meminitdata;
276 static unsigned long required_kernelcore __initdata;
277 static unsigned long required_kernelcore_percent __initdata;
278 static unsigned long required_movablecore __initdata;
279 static unsigned long required_movablecore_percent __initdata;
280 static unsigned long zone_movable_pfn[MAX_NUMNODES] __meminitdata;
281 static bool mirrored_kernelcore __meminitdata;
283 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
285 EXPORT_SYMBOL(movable_zone);
286 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
289 int nr_node_ids __read_mostly = MAX_NUMNODES;
290 int nr_online_nodes __read_mostly = 1;
291 EXPORT_SYMBOL(nr_node_ids);
292 EXPORT_SYMBOL(nr_online_nodes);
295 int page_group_by_mobility_disabled __read_mostly;
297 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
299 * During boot we initialize deferred pages on-demand, as needed, but once
300 * page_alloc_init_late() has finished, the deferred pages are all initialized,
301 * and we can permanently disable that path.
303 static DEFINE_STATIC_KEY_TRUE(deferred_pages);
306 * Calling kasan_free_pages() only after deferred memory initialization
307 * has completed. Poisoning pages during deferred memory init will greatly
308 * lengthen the process and cause problem in large memory systems as the
309 * deferred pages initialization is done with interrupt disabled.
311 * Assuming that there will be no reference to those newly initialized
312 * pages before they are ever allocated, this should have no effect on
313 * KASAN memory tracking as the poison will be properly inserted at page
314 * allocation time. The only corner case is when pages are allocated by
315 * on-demand allocation and then freed again before the deferred pages
316 * initialization is done, but this is not likely to happen.
318 static inline void kasan_free_nondeferred_pages(struct page *page, int order)
320 if (!static_branch_unlikely(&deferred_pages))
321 kasan_free_pages(page, order);
324 /* Returns true if the struct page for the pfn is uninitialised */
325 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
327 int nid = early_pfn_to_nid(pfn);
329 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
336 * Returns false when the remaining initialisation should be deferred until
337 * later in the boot cycle when it can be parallelised.
339 static inline bool update_defer_init(pg_data_t *pgdat,
340 unsigned long pfn, unsigned long zone_end,
341 unsigned long *nr_initialised)
343 /* Always populate low zones for address-constrained allocations */
344 if (zone_end < pgdat_end_pfn(pgdat))
347 if ((*nr_initialised > pgdat->static_init_pgcnt) &&
348 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
349 pgdat->first_deferred_pfn = pfn;
356 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
358 static inline bool early_page_uninitialised(unsigned long pfn)
363 static inline bool update_defer_init(pg_data_t *pgdat,
364 unsigned long pfn, unsigned long zone_end,
365 unsigned long *nr_initialised)
371 /* Return a pointer to the bitmap storing bits affecting a block of pages */
372 static inline unsigned long *get_pageblock_bitmap(struct page *page,
375 #ifdef CONFIG_SPARSEMEM
376 return __pfn_to_section(pfn)->pageblock_flags;
378 return page_zone(page)->pageblock_flags;
379 #endif /* CONFIG_SPARSEMEM */
382 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
384 #ifdef CONFIG_SPARSEMEM
385 pfn &= (PAGES_PER_SECTION-1);
386 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
388 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
389 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
390 #endif /* CONFIG_SPARSEMEM */
394 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
395 * @page: The page within the block of interest
396 * @pfn: The target page frame number
397 * @end_bitidx: The last bit of interest to retrieve
398 * @mask: mask of bits that the caller is interested in
400 * Return: pageblock_bits flags
402 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
404 unsigned long end_bitidx,
407 unsigned long *bitmap;
408 unsigned long bitidx, word_bitidx;
411 bitmap = get_pageblock_bitmap(page, pfn);
412 bitidx = pfn_to_bitidx(page, pfn);
413 word_bitidx = bitidx / BITS_PER_LONG;
414 bitidx &= (BITS_PER_LONG-1);
416 word = bitmap[word_bitidx];
417 bitidx += end_bitidx;
418 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
421 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
422 unsigned long end_bitidx,
425 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
428 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
430 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
434 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
435 * @page: The page within the block of interest
436 * @flags: The flags to set
437 * @pfn: The target page frame number
438 * @end_bitidx: The last bit of interest
439 * @mask: mask of bits that the caller is interested in
441 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
443 unsigned long end_bitidx,
446 unsigned long *bitmap;
447 unsigned long bitidx, word_bitidx;
448 unsigned long old_word, word;
450 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
452 bitmap = get_pageblock_bitmap(page, pfn);
453 bitidx = pfn_to_bitidx(page, pfn);
454 word_bitidx = bitidx / BITS_PER_LONG;
455 bitidx &= (BITS_PER_LONG-1);
457 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
459 bitidx += end_bitidx;
460 mask <<= (BITS_PER_LONG - bitidx - 1);
461 flags <<= (BITS_PER_LONG - bitidx - 1);
463 word = READ_ONCE(bitmap[word_bitidx]);
465 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
466 if (word == old_word)
472 void set_pageblock_migratetype(struct page *page, int migratetype)
474 if (unlikely(page_group_by_mobility_disabled &&
475 migratetype < MIGRATE_PCPTYPES))
476 migratetype = MIGRATE_UNMOVABLE;
478 set_pageblock_flags_group(page, (unsigned long)migratetype,
479 PB_migrate, PB_migrate_end);
482 #ifdef CONFIG_DEBUG_VM
483 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
487 unsigned long pfn = page_to_pfn(page);
488 unsigned long sp, start_pfn;
491 seq = zone_span_seqbegin(zone);
492 start_pfn = zone->zone_start_pfn;
493 sp = zone->spanned_pages;
494 if (!zone_spans_pfn(zone, pfn))
496 } while (zone_span_seqretry(zone, seq));
499 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
500 pfn, zone_to_nid(zone), zone->name,
501 start_pfn, start_pfn + sp);
506 static int page_is_consistent(struct zone *zone, struct page *page)
508 if (!pfn_valid_within(page_to_pfn(page)))
510 if (zone != page_zone(page))
516 * Temporary debugging check for pages not lying within a given zone.
518 static int __maybe_unused bad_range(struct zone *zone, struct page *page)
520 if (page_outside_zone_boundaries(zone, page))
522 if (!page_is_consistent(zone, page))
528 static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
534 static void bad_page(struct page *page, const char *reason,
535 unsigned long bad_flags)
537 static unsigned long resume;
538 static unsigned long nr_shown;
539 static unsigned long nr_unshown;
542 * Allow a burst of 60 reports, then keep quiet for that minute;
543 * or allow a steady drip of one report per second.
545 if (nr_shown == 60) {
546 if (time_before(jiffies, resume)) {
552 "BUG: Bad page state: %lu messages suppressed\n",
559 resume = jiffies + 60 * HZ;
561 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
562 current->comm, page_to_pfn(page));
563 __dump_page(page, reason);
564 bad_flags &= page->flags;
566 pr_alert("bad because of flags: %#lx(%pGp)\n",
567 bad_flags, &bad_flags);
568 dump_page_owner(page);
573 /* Leave bad fields for debug, except PageBuddy could make trouble */
574 page_mapcount_reset(page); /* remove PageBuddy */
575 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
579 * Higher-order pages are called "compound pages". They are structured thusly:
581 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
583 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
584 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
586 * The first tail page's ->compound_dtor holds the offset in array of compound
587 * page destructors. See compound_page_dtors.
589 * The first tail page's ->compound_order holds the order of allocation.
590 * This usage means that zero-order pages may not be compound.
593 void free_compound_page(struct page *page)
595 __free_pages_ok(page, compound_order(page));
598 void prep_compound_page(struct page *page, unsigned int order)
601 int nr_pages = 1 << order;
603 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
604 set_compound_order(page, order);
606 for (i = 1; i < nr_pages; i++) {
607 struct page *p = page + i;
608 set_page_count(p, 0);
609 p->mapping = TAIL_MAPPING;
610 set_compound_head(p, page);
612 atomic_set(compound_mapcount_ptr(page), -1);
615 #ifdef CONFIG_DEBUG_PAGEALLOC
616 unsigned int _debug_guardpage_minorder;
617 bool _debug_pagealloc_enabled __read_mostly
618 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
619 EXPORT_SYMBOL(_debug_pagealloc_enabled);
620 bool _debug_guardpage_enabled __read_mostly;
622 static int __init early_debug_pagealloc(char *buf)
626 return kstrtobool(buf, &_debug_pagealloc_enabled);
628 early_param("debug_pagealloc", early_debug_pagealloc);
630 static bool need_debug_guardpage(void)
632 /* If we don't use debug_pagealloc, we don't need guard page */
633 if (!debug_pagealloc_enabled())
636 if (!debug_guardpage_minorder())
642 static void init_debug_guardpage(void)
644 if (!debug_pagealloc_enabled())
647 if (!debug_guardpage_minorder())
650 _debug_guardpage_enabled = true;
653 struct page_ext_operations debug_guardpage_ops = {
654 .need = need_debug_guardpage,
655 .init = init_debug_guardpage,
658 static int __init debug_guardpage_minorder_setup(char *buf)
662 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
663 pr_err("Bad debug_guardpage_minorder value\n");
666 _debug_guardpage_minorder = res;
667 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
670 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
672 static inline bool set_page_guard(struct zone *zone, struct page *page,
673 unsigned int order, int migratetype)
675 struct page_ext *page_ext;
677 if (!debug_guardpage_enabled())
680 if (order >= debug_guardpage_minorder())
683 page_ext = lookup_page_ext(page);
684 if (unlikely(!page_ext))
687 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
689 INIT_LIST_HEAD(&page->lru);
690 set_page_private(page, order);
691 /* Guard pages are not available for any usage */
692 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
697 static inline void clear_page_guard(struct zone *zone, struct page *page,
698 unsigned int order, int migratetype)
700 struct page_ext *page_ext;
702 if (!debug_guardpage_enabled())
705 page_ext = lookup_page_ext(page);
706 if (unlikely(!page_ext))
709 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
711 set_page_private(page, 0);
712 if (!is_migrate_isolate(migratetype))
713 __mod_zone_freepage_state(zone, (1 << order), migratetype);
716 struct page_ext_operations debug_guardpage_ops;
717 static inline bool set_page_guard(struct zone *zone, struct page *page,
718 unsigned int order, int migratetype) { return false; }
719 static inline void clear_page_guard(struct zone *zone, struct page *page,
720 unsigned int order, int migratetype) {}
723 static inline void set_page_order(struct page *page, unsigned int order)
725 set_page_private(page, order);
726 __SetPageBuddy(page);
729 static inline void rmv_page_order(struct page *page)
731 __ClearPageBuddy(page);
732 set_page_private(page, 0);
736 * This function checks whether a page is free && is the buddy
737 * we can coalesce a page and its buddy if
738 * (a) the buddy is not in a hole (check before calling!) &&
739 * (b) the buddy is in the buddy system &&
740 * (c) a page and its buddy have the same order &&
741 * (d) a page and its buddy are in the same zone.
743 * For recording whether a page is in the buddy system, we set PageBuddy.
744 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
746 * For recording page's order, we use page_private(page).
748 static inline int page_is_buddy(struct page *page, struct page *buddy,
751 if (page_is_guard(buddy) && page_order(buddy) == order) {
752 if (page_zone_id(page) != page_zone_id(buddy))
755 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
760 if (PageBuddy(buddy) && page_order(buddy) == order) {
762 * zone check is done late to avoid uselessly
763 * calculating zone/node ids for pages that could
766 if (page_zone_id(page) != page_zone_id(buddy))
769 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
777 * Freeing function for a buddy system allocator.
779 * The concept of a buddy system is to maintain direct-mapped table
780 * (containing bit values) for memory blocks of various "orders".
781 * The bottom level table contains the map for the smallest allocatable
782 * units of memory (here, pages), and each level above it describes
783 * pairs of units from the levels below, hence, "buddies".
784 * At a high level, all that happens here is marking the table entry
785 * at the bottom level available, and propagating the changes upward
786 * as necessary, plus some accounting needed to play nicely with other
787 * parts of the VM system.
788 * At each level, we keep a list of pages, which are heads of continuous
789 * free pages of length of (1 << order) and marked with PageBuddy.
790 * Page's order is recorded in page_private(page) field.
791 * So when we are allocating or freeing one, we can derive the state of the
792 * other. That is, if we allocate a small block, and both were
793 * free, the remainder of the region must be split into blocks.
794 * If a block is freed, and its buddy is also free, then this
795 * triggers coalescing into a block of larger size.
800 static inline void __free_one_page(struct page *page,
802 struct zone *zone, unsigned int order,
805 unsigned long combined_pfn;
806 unsigned long uninitialized_var(buddy_pfn);
808 unsigned int max_order;
810 max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order);
812 VM_BUG_ON(!zone_is_initialized(zone));
813 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
815 VM_BUG_ON(migratetype == -1);
816 if (likely(!is_migrate_isolate(migratetype)))
817 __mod_zone_freepage_state(zone, 1 << order, migratetype);
819 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
820 VM_BUG_ON_PAGE(bad_range(zone, page), page);
823 while (order < max_order) {
824 buddy_pfn = __find_buddy_pfn(pfn, order);
825 buddy = page + (buddy_pfn - pfn);
827 if (!pfn_valid_within(buddy_pfn))
829 if (!page_is_buddy(page, buddy, order))
832 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
833 * merge with it and move up one order.
835 if (page_is_guard(buddy)) {
836 clear_page_guard(zone, buddy, order, migratetype);
838 list_del(&buddy->lru);
839 zone->free_area[order].nr_free--;
840 rmv_page_order(buddy);
842 combined_pfn = buddy_pfn & pfn;
843 page = page + (combined_pfn - pfn);
847 if (order < MAX_ORDER - 1) {
848 /* If we are here, it means order is >= pageblock_order.
849 * We want to prevent merge between freepages on isolate
850 * pageblock and normal pageblock. Without this, pageblock
851 * isolation could cause incorrect freepage or CMA accounting.
853 * We don't want to hit this code for the more frequent
856 if (unlikely(has_isolate_pageblock(zone))) {
859 buddy_pfn = __find_buddy_pfn(pfn, order);
860 buddy = page + (buddy_pfn - pfn);
861 buddy_mt = get_pageblock_migratetype(buddy);
863 if (migratetype != buddy_mt
864 && (is_migrate_isolate(migratetype) ||
865 is_migrate_isolate(buddy_mt)))
868 max_order = order + 1;
869 goto continue_merging;
873 set_page_order(page, order);
876 * If this is not the largest possible page, check if the buddy
877 * of the next-highest order is free. If it is, it's possible
878 * that pages are being freed that will coalesce soon. In case,
879 * that is happening, add the free page to the tail of the list
880 * so it's less likely to be used soon and more likely to be merged
881 * as a higher order page
883 if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) {
884 struct page *higher_page, *higher_buddy;
885 combined_pfn = buddy_pfn & pfn;
886 higher_page = page + (combined_pfn - pfn);
887 buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
888 higher_buddy = higher_page + (buddy_pfn - combined_pfn);
889 if (pfn_valid_within(buddy_pfn) &&
890 page_is_buddy(higher_page, higher_buddy, order + 1)) {
891 list_add_tail(&page->lru,
892 &zone->free_area[order].free_list[migratetype]);
897 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
899 zone->free_area[order].nr_free++;
903 * A bad page could be due to a number of fields. Instead of multiple branches,
904 * try and check multiple fields with one check. The caller must do a detailed
905 * check if necessary.
907 static inline bool page_expected_state(struct page *page,
908 unsigned long check_flags)
910 if (unlikely(atomic_read(&page->_mapcount) != -1))
913 if (unlikely((unsigned long)page->mapping |
914 page_ref_count(page) |
916 (unsigned long)page->mem_cgroup |
918 (page->flags & check_flags)))
924 static void free_pages_check_bad(struct page *page)
926 const char *bad_reason;
927 unsigned long bad_flags;
932 if (unlikely(atomic_read(&page->_mapcount) != -1))
933 bad_reason = "nonzero mapcount";
934 if (unlikely(page->mapping != NULL))
935 bad_reason = "non-NULL mapping";
936 if (unlikely(page_ref_count(page) != 0))
937 bad_reason = "nonzero _refcount";
938 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
939 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
940 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
943 if (unlikely(page->mem_cgroup))
944 bad_reason = "page still charged to cgroup";
946 bad_page(page, bad_reason, bad_flags);
949 static inline int free_pages_check(struct page *page)
951 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
954 /* Something has gone sideways, find it */
955 free_pages_check_bad(page);
959 static int free_tail_pages_check(struct page *head_page, struct page *page)
964 * We rely page->lru.next never has bit 0 set, unless the page
965 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
967 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
969 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
973 switch (page - head_page) {
975 /* the first tail page: ->mapping may be compound_mapcount() */
976 if (unlikely(compound_mapcount(page))) {
977 bad_page(page, "nonzero compound_mapcount", 0);
983 * the second tail page: ->mapping is
984 * deferred_list.next -- ignore value.
988 if (page->mapping != TAIL_MAPPING) {
989 bad_page(page, "corrupted mapping in tail page", 0);
994 if (unlikely(!PageTail(page))) {
995 bad_page(page, "PageTail not set", 0);
998 if (unlikely(compound_head(page) != head_page)) {
999 bad_page(page, "compound_head not consistent", 0);
1004 page->mapping = NULL;
1005 clear_compound_head(page);
1009 static __always_inline bool free_pages_prepare(struct page *page,
1010 unsigned int order, bool check_free)
1014 VM_BUG_ON_PAGE(PageTail(page), page);
1016 trace_mm_page_free(page, order);
1019 * Check tail pages before head page information is cleared to
1020 * avoid checking PageCompound for order-0 pages.
1022 if (unlikely(order)) {
1023 bool compound = PageCompound(page);
1026 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1029 ClearPageDoubleMap(page);
1030 for (i = 1; i < (1 << order); i++) {
1032 bad += free_tail_pages_check(page, page + i);
1033 if (unlikely(free_pages_check(page + i))) {
1037 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1040 if (PageMappingFlags(page))
1041 page->mapping = NULL;
1042 if (memcg_kmem_enabled() && PageKmemcg(page))
1043 memcg_kmem_uncharge(page, order);
1045 bad += free_pages_check(page);
1049 page_cpupid_reset_last(page);
1050 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1051 reset_page_owner(page, order);
1053 if (!PageHighMem(page)) {
1054 debug_check_no_locks_freed(page_address(page),
1055 PAGE_SIZE << order);
1056 debug_check_no_obj_freed(page_address(page),
1057 PAGE_SIZE << order);
1059 arch_free_page(page, order);
1060 kernel_poison_pages(page, 1 << order, 0);
1061 kernel_map_pages(page, 1 << order, 0);
1062 kasan_free_nondeferred_pages(page, order);
1067 #ifdef CONFIG_DEBUG_VM
1068 static inline bool free_pcp_prepare(struct page *page)
1070 return free_pages_prepare(page, 0, true);
1073 static inline bool bulkfree_pcp_prepare(struct page *page)
1078 static bool free_pcp_prepare(struct page *page)
1080 return free_pages_prepare(page, 0, false);
1083 static bool bulkfree_pcp_prepare(struct page *page)
1085 return free_pages_check(page);
1087 #endif /* CONFIG_DEBUG_VM */
1089 static inline void prefetch_buddy(struct page *page)
1091 unsigned long pfn = page_to_pfn(page);
1092 unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0);
1093 struct page *buddy = page + (buddy_pfn - pfn);
1099 * Frees a number of pages from the PCP lists
1100 * Assumes all pages on list are in same zone, and of same order.
1101 * count is the number of pages to free.
1103 * If the zone was previously in an "all pages pinned" state then look to
1104 * see if this freeing clears that state.
1106 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1107 * pinned" detection logic.
1109 static void free_pcppages_bulk(struct zone *zone, int count,
1110 struct per_cpu_pages *pcp)
1112 int migratetype = 0;
1114 int prefetch_nr = 0;
1115 bool isolated_pageblocks;
1116 struct page *page, *tmp;
1120 * Ensure proper count is passed which otherwise would stuck in the
1121 * below while (list_empty(list)) loop.
1123 count = min(pcp->count, count);
1125 struct list_head *list;
1128 * Remove pages from lists in a round-robin fashion. A
1129 * batch_free count is maintained that is incremented when an
1130 * empty list is encountered. This is so more pages are freed
1131 * off fuller lists instead of spinning excessively around empty
1136 if (++migratetype == MIGRATE_PCPTYPES)
1138 list = &pcp->lists[migratetype];
1139 } while (list_empty(list));
1141 /* This is the only non-empty list. Free them all. */
1142 if (batch_free == MIGRATE_PCPTYPES)
1146 page = list_last_entry(list, struct page, lru);
1147 /* must delete to avoid corrupting pcp list */
1148 list_del(&page->lru);
1151 if (bulkfree_pcp_prepare(page))
1154 list_add_tail(&page->lru, &head);
1157 * We are going to put the page back to the global
1158 * pool, prefetch its buddy to speed up later access
1159 * under zone->lock. It is believed the overhead of
1160 * an additional test and calculating buddy_pfn here
1161 * can be offset by reduced memory latency later. To
1162 * avoid excessive prefetching due to large count, only
1163 * prefetch buddy for the first pcp->batch nr of pages.
1165 if (prefetch_nr++ < pcp->batch)
1166 prefetch_buddy(page);
1167 } while (--count && --batch_free && !list_empty(list));
1170 spin_lock(&zone->lock);
1171 isolated_pageblocks = has_isolate_pageblock(zone);
1174 * Use safe version since after __free_one_page(),
1175 * page->lru.next will not point to original list.
1177 list_for_each_entry_safe(page, tmp, &head, lru) {
1178 int mt = get_pcppage_migratetype(page);
1179 /* MIGRATE_ISOLATE page should not go to pcplists */
1180 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1181 /* Pageblock could have been isolated meanwhile */
1182 if (unlikely(isolated_pageblocks))
1183 mt = get_pageblock_migratetype(page);
1185 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1186 trace_mm_page_pcpu_drain(page, 0, mt);
1188 spin_unlock(&zone->lock);
1191 static void free_one_page(struct zone *zone,
1192 struct page *page, unsigned long pfn,
1196 spin_lock(&zone->lock);
1197 if (unlikely(has_isolate_pageblock(zone) ||
1198 is_migrate_isolate(migratetype))) {
1199 migratetype = get_pfnblock_migratetype(page, pfn);
1201 __free_one_page(page, pfn, zone, order, migratetype);
1202 spin_unlock(&zone->lock);
1205 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1206 unsigned long zone, int nid)
1208 mm_zero_struct_page(page);
1209 set_page_links(page, zone, nid, pfn);
1210 init_page_count(page);
1211 page_mapcount_reset(page);
1212 page_cpupid_reset_last(page);
1214 INIT_LIST_HEAD(&page->lru);
1215 #ifdef WANT_PAGE_VIRTUAL
1216 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1217 if (!is_highmem_idx(zone))
1218 set_page_address(page, __va(pfn << PAGE_SHIFT));
1222 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1223 static void __meminit init_reserved_page(unsigned long pfn)
1228 if (!early_page_uninitialised(pfn))
1231 nid = early_pfn_to_nid(pfn);
1232 pgdat = NODE_DATA(nid);
1234 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1235 struct zone *zone = &pgdat->node_zones[zid];
1237 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1240 __init_single_page(pfn_to_page(pfn), pfn, zid, nid);
1243 static inline void init_reserved_page(unsigned long pfn)
1246 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1249 * Initialised pages do not have PageReserved set. This function is
1250 * called for each range allocated by the bootmem allocator and
1251 * marks the pages PageReserved. The remaining valid pages are later
1252 * sent to the buddy page allocator.
1254 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1256 unsigned long start_pfn = PFN_DOWN(start);
1257 unsigned long end_pfn = PFN_UP(end);
1259 for (; start_pfn < end_pfn; start_pfn++) {
1260 if (pfn_valid(start_pfn)) {
1261 struct page *page = pfn_to_page(start_pfn);
1263 init_reserved_page(start_pfn);
1265 /* Avoid false-positive PageTail() */
1266 INIT_LIST_HEAD(&page->lru);
1268 SetPageReserved(page);
1273 static void __free_pages_ok(struct page *page, unsigned int order)
1275 unsigned long flags;
1277 unsigned long pfn = page_to_pfn(page);
1279 if (!free_pages_prepare(page, order, true))
1282 migratetype = get_pfnblock_migratetype(page, pfn);
1283 local_irq_save(flags);
1284 __count_vm_events(PGFREE, 1 << order);
1285 free_one_page(page_zone(page), page, pfn, order, migratetype);
1286 local_irq_restore(flags);
1289 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1291 unsigned int nr_pages = 1 << order;
1292 struct page *p = page;
1296 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1298 __ClearPageReserved(p);
1299 set_page_count(p, 0);
1301 __ClearPageReserved(p);
1302 set_page_count(p, 0);
1304 page_zone(page)->managed_pages += nr_pages;
1305 set_page_refcounted(page);
1306 __free_pages(page, order);
1309 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1310 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1312 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1314 int __meminit early_pfn_to_nid(unsigned long pfn)
1316 static DEFINE_SPINLOCK(early_pfn_lock);
1319 spin_lock(&early_pfn_lock);
1320 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1322 nid = first_online_node;
1323 spin_unlock(&early_pfn_lock);
1329 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1330 static inline bool __meminit __maybe_unused
1331 meminit_pfn_in_nid(unsigned long pfn, int node,
1332 struct mminit_pfnnid_cache *state)
1336 nid = __early_pfn_to_nid(pfn, state);
1337 if (nid >= 0 && nid != node)
1342 /* Only safe to use early in boot when initialisation is single-threaded */
1343 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1345 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1350 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1354 static inline bool __meminit __maybe_unused
1355 meminit_pfn_in_nid(unsigned long pfn, int node,
1356 struct mminit_pfnnid_cache *state)
1363 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1366 if (early_page_uninitialised(pfn))
1368 return __free_pages_boot_core(page, order);
1372 * Check that the whole (or subset of) a pageblock given by the interval of
1373 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1374 * with the migration of free compaction scanner. The scanners then need to
1375 * use only pfn_valid_within() check for arches that allow holes within
1378 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1380 * It's possible on some configurations to have a setup like node0 node1 node0
1381 * i.e. it's possible that all pages within a zones range of pages do not
1382 * belong to a single zone. We assume that a border between node0 and node1
1383 * can occur within a single pageblock, but not a node0 node1 node0
1384 * interleaving within a single pageblock. It is therefore sufficient to check
1385 * the first and last page of a pageblock and avoid checking each individual
1386 * page in a pageblock.
1388 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1389 unsigned long end_pfn, struct zone *zone)
1391 struct page *start_page;
1392 struct page *end_page;
1394 /* end_pfn is one past the range we are checking */
1397 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1400 start_page = pfn_to_online_page(start_pfn);
1404 if (page_zone(start_page) != zone)
1407 end_page = pfn_to_page(end_pfn);
1409 /* This gives a shorter code than deriving page_zone(end_page) */
1410 if (page_zone_id(start_page) != page_zone_id(end_page))
1416 void set_zone_contiguous(struct zone *zone)
1418 unsigned long block_start_pfn = zone->zone_start_pfn;
1419 unsigned long block_end_pfn;
1421 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1422 for (; block_start_pfn < zone_end_pfn(zone);
1423 block_start_pfn = block_end_pfn,
1424 block_end_pfn += pageblock_nr_pages) {
1426 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1428 if (!__pageblock_pfn_to_page(block_start_pfn,
1429 block_end_pfn, zone))
1434 /* We confirm that there is no hole */
1435 zone->contiguous = true;
1438 void clear_zone_contiguous(struct zone *zone)
1440 zone->contiguous = false;
1443 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1444 static void __init deferred_free_range(unsigned long pfn,
1445 unsigned long nr_pages)
1453 page = pfn_to_page(pfn);
1455 /* Free a large naturally-aligned chunk if possible */
1456 if (nr_pages == pageblock_nr_pages &&
1457 (pfn & (pageblock_nr_pages - 1)) == 0) {
1458 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1459 __free_pages_boot_core(page, pageblock_order);
1463 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1464 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1465 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1466 __free_pages_boot_core(page, 0);
1470 /* Completion tracking for deferred_init_memmap() threads */
1471 static atomic_t pgdat_init_n_undone __initdata;
1472 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1474 static inline void __init pgdat_init_report_one_done(void)
1476 if (atomic_dec_and_test(&pgdat_init_n_undone))
1477 complete(&pgdat_init_all_done_comp);
1481 * Returns true if page needs to be initialized or freed to buddy allocator.
1483 * First we check if pfn is valid on architectures where it is possible to have
1484 * holes within pageblock_nr_pages. On systems where it is not possible, this
1485 * function is optimized out.
1487 * Then, we check if a current large page is valid by only checking the validity
1490 * Finally, meminit_pfn_in_nid is checked on systems where pfns can interleave
1491 * within a node: a pfn is between start and end of a node, but does not belong
1492 * to this memory node.
1494 static inline bool __init
1495 deferred_pfn_valid(int nid, unsigned long pfn,
1496 struct mminit_pfnnid_cache *nid_init_state)
1498 if (!pfn_valid_within(pfn))
1500 if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
1502 if (!meminit_pfn_in_nid(pfn, nid, nid_init_state))
1508 * Free pages to buddy allocator. Try to free aligned pages in
1509 * pageblock_nr_pages sizes.
1511 static void __init deferred_free_pages(int nid, int zid, unsigned long pfn,
1512 unsigned long end_pfn)
1514 struct mminit_pfnnid_cache nid_init_state = { };
1515 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1516 unsigned long nr_free = 0;
1518 for (; pfn < end_pfn; pfn++) {
1519 if (!deferred_pfn_valid(nid, pfn, &nid_init_state)) {
1520 deferred_free_range(pfn - nr_free, nr_free);
1522 } else if (!(pfn & nr_pgmask)) {
1523 deferred_free_range(pfn - nr_free, nr_free);
1525 touch_nmi_watchdog();
1530 /* Free the last block of pages to allocator */
1531 deferred_free_range(pfn - nr_free, nr_free);
1535 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1536 * by performing it only once every pageblock_nr_pages.
1537 * Return number of pages initialized.
1539 static unsigned long __init deferred_init_pages(int nid, int zid,
1541 unsigned long end_pfn)
1543 struct mminit_pfnnid_cache nid_init_state = { };
1544 unsigned long nr_pgmask = pageblock_nr_pages - 1;
1545 unsigned long nr_pages = 0;
1546 struct page *page = NULL;
1548 for (; pfn < end_pfn; pfn++) {
1549 if (!deferred_pfn_valid(nid, pfn, &nid_init_state)) {
1552 } else if (!page || !(pfn & nr_pgmask)) {
1553 page = pfn_to_page(pfn);
1554 touch_nmi_watchdog();
1558 __init_single_page(page, pfn, zid, nid);
1564 /* Initialise remaining memory on a node */
1565 static int __init deferred_init_memmap(void *data)
1567 pg_data_t *pgdat = data;
1568 int nid = pgdat->node_id;
1569 unsigned long start = jiffies;
1570 unsigned long nr_pages = 0;
1571 unsigned long spfn, epfn, first_init_pfn, flags;
1572 phys_addr_t spa, epa;
1575 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1578 /* Bind memory initialisation thread to a local node if possible */
1579 if (!cpumask_empty(cpumask))
1580 set_cpus_allowed_ptr(current, cpumask);
1582 pgdat_resize_lock(pgdat, &flags);
1583 first_init_pfn = pgdat->first_deferred_pfn;
1584 if (first_init_pfn == ULONG_MAX) {
1585 pgdat_resize_unlock(pgdat, &flags);
1586 pgdat_init_report_one_done();
1590 /* Sanity check boundaries */
1591 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1592 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1593 pgdat->first_deferred_pfn = ULONG_MAX;
1596 * Once we unlock here, the zone cannot be grown anymore, thus if an
1597 * interrupt thread must allocate this early in boot, zone must be
1598 * pre-grown prior to start of deferred page initialization.
1600 pgdat_resize_unlock(pgdat, &flags);
1602 /* Only the highest zone is deferred so find it */
1603 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1604 zone = pgdat->node_zones + zid;
1605 if (first_init_pfn < zone_end_pfn(zone))
1608 first_init_pfn = max(zone->zone_start_pfn, first_init_pfn);
1611 * Initialize and free pages. We do it in two loops: first we initialize
1612 * struct page, than free to buddy allocator, because while we are
1613 * freeing pages we can access pages that are ahead (computing buddy
1614 * page in __free_one_page()).
1616 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1617 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1618 epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
1619 nr_pages += deferred_init_pages(nid, zid, spfn, epfn);
1621 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1622 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1623 epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
1624 deferred_free_pages(nid, zid, spfn, epfn);
1627 /* Sanity check that the next zone really is unpopulated */
1628 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1630 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1631 jiffies_to_msecs(jiffies - start));
1633 pgdat_init_report_one_done();
1638 * If this zone has deferred pages, try to grow it by initializing enough
1639 * deferred pages to satisfy the allocation specified by order, rounded up to
1640 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1641 * of SECTION_SIZE bytes by initializing struct pages in increments of
1642 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1644 * Return true when zone was grown, otherwise return false. We return true even
1645 * when we grow less than requested, to let the caller decide if there are
1646 * enough pages to satisfy the allocation.
1648 * Note: We use noinline because this function is needed only during boot, and
1649 * it is called from a __ref function _deferred_grow_zone. This way we are
1650 * making sure that it is not inlined into permanent text section.
1652 static noinline bool __init
1653 deferred_grow_zone(struct zone *zone, unsigned int order)
1655 int zid = zone_idx(zone);
1656 int nid = zone_to_nid(zone);
1657 pg_data_t *pgdat = NODE_DATA(nid);
1658 unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION);
1659 unsigned long nr_pages = 0;
1660 unsigned long first_init_pfn, spfn, epfn, t, flags;
1661 unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;
1662 phys_addr_t spa, epa;
1665 /* Only the last zone may have deferred pages */
1666 if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))
1669 pgdat_resize_lock(pgdat, &flags);
1672 * If someone grew this zone while we were waiting for spinlock, return
1673 * true, as there might be enough pages already.
1675 if (first_deferred_pfn != pgdat->first_deferred_pfn) {
1676 pgdat_resize_unlock(pgdat, &flags);
1680 first_init_pfn = max(zone->zone_start_pfn, first_deferred_pfn);
1682 if (first_init_pfn >= pgdat_end_pfn(pgdat)) {
1683 pgdat_resize_unlock(pgdat, &flags);
1687 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1688 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1689 epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa));
1691 while (spfn < epfn && nr_pages < nr_pages_needed) {
1692 t = ALIGN(spfn + PAGES_PER_SECTION, PAGES_PER_SECTION);
1693 first_deferred_pfn = min(t, epfn);
1694 nr_pages += deferred_init_pages(nid, zid, spfn,
1695 first_deferred_pfn);
1696 spfn = first_deferred_pfn;
1699 if (nr_pages >= nr_pages_needed)
1703 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) {
1704 spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa));
1705 epfn = min_t(unsigned long, first_deferred_pfn, PFN_DOWN(epa));
1706 deferred_free_pages(nid, zid, spfn, epfn);
1708 if (first_deferred_pfn == epfn)
1711 pgdat->first_deferred_pfn = first_deferred_pfn;
1712 pgdat_resize_unlock(pgdat, &flags);
1714 return nr_pages > 0;
1718 * deferred_grow_zone() is __init, but it is called from
1719 * get_page_from_freelist() during early boot until deferred_pages permanently
1720 * disables this call. This is why we have refdata wrapper to avoid warning,
1721 * and to ensure that the function body gets unloaded.
1724 _deferred_grow_zone(struct zone *zone, unsigned int order)
1726 return deferred_grow_zone(zone, order);
1729 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1731 void __init page_alloc_init_late(void)
1735 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1738 /* There will be num_node_state(N_MEMORY) threads */
1739 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1740 for_each_node_state(nid, N_MEMORY) {
1741 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1744 /* Block until all are initialised */
1745 wait_for_completion(&pgdat_init_all_done_comp);
1748 * The number of managed pages has changed due to the initialisation
1749 * so the pcpu batch and high limits needs to be updated or the limits
1750 * will be artificially small.
1752 for_each_populated_zone(zone)
1753 zone_pcp_update(zone);
1756 * We initialized the rest of the deferred pages. Permanently disable
1757 * on-demand struct page initialization.
1759 static_branch_disable(&deferred_pages);
1761 /* Reinit limits that are based on free pages after the kernel is up */
1762 files_maxfiles_init();
1764 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
1765 /* Discard memblock private memory */
1769 for_each_populated_zone(zone)
1770 set_zone_contiguous(zone);
1774 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1775 void __init init_cma_reserved_pageblock(struct page *page)
1777 unsigned i = pageblock_nr_pages;
1778 struct page *p = page;
1781 __ClearPageReserved(p);
1782 set_page_count(p, 0);
1785 set_pageblock_migratetype(page, MIGRATE_CMA);
1787 if (pageblock_order >= MAX_ORDER) {
1788 i = pageblock_nr_pages;
1791 set_page_refcounted(p);
1792 __free_pages(p, MAX_ORDER - 1);
1793 p += MAX_ORDER_NR_PAGES;
1794 } while (i -= MAX_ORDER_NR_PAGES);
1796 set_page_refcounted(page);
1797 __free_pages(page, pageblock_order);
1800 adjust_managed_page_count(page, pageblock_nr_pages);
1805 * The order of subdivision here is critical for the IO subsystem.
1806 * Please do not alter this order without good reasons and regression
1807 * testing. Specifically, as large blocks of memory are subdivided,
1808 * the order in which smaller blocks are delivered depends on the order
1809 * they're subdivided in this function. This is the primary factor
1810 * influencing the order in which pages are delivered to the IO
1811 * subsystem according to empirical testing, and this is also justified
1812 * by considering the behavior of a buddy system containing a single
1813 * large block of memory acted on by a series of small allocations.
1814 * This behavior is a critical factor in sglist merging's success.
1818 static inline void expand(struct zone *zone, struct page *page,
1819 int low, int high, struct free_area *area,
1822 unsigned long size = 1 << high;
1824 while (high > low) {
1828 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1831 * Mark as guard pages (or page), that will allow to
1832 * merge back to allocator when buddy will be freed.
1833 * Corresponding page table entries will not be touched,
1834 * pages will stay not present in virtual address space
1836 if (set_page_guard(zone, &page[size], high, migratetype))
1839 list_add(&page[size].lru, &area->free_list[migratetype]);
1841 set_page_order(&page[size], high);
1845 static void check_new_page_bad(struct page *page)
1847 const char *bad_reason = NULL;
1848 unsigned long bad_flags = 0;
1850 if (unlikely(atomic_read(&page->_mapcount) != -1))
1851 bad_reason = "nonzero mapcount";
1852 if (unlikely(page->mapping != NULL))
1853 bad_reason = "non-NULL mapping";
1854 if (unlikely(page_ref_count(page) != 0))
1855 bad_reason = "nonzero _count";
1856 if (unlikely(page->flags & __PG_HWPOISON)) {
1857 bad_reason = "HWPoisoned (hardware-corrupted)";
1858 bad_flags = __PG_HWPOISON;
1859 /* Don't complain about hwpoisoned pages */
1860 page_mapcount_reset(page); /* remove PageBuddy */
1863 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1864 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1865 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1868 if (unlikely(page->mem_cgroup))
1869 bad_reason = "page still charged to cgroup";
1871 bad_page(page, bad_reason, bad_flags);
1875 * This page is about to be returned from the page allocator
1877 static inline int check_new_page(struct page *page)
1879 if (likely(page_expected_state(page,
1880 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
1883 check_new_page_bad(page);
1887 static inline bool free_pages_prezeroed(void)
1889 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1890 page_poisoning_enabled();
1893 #ifdef CONFIG_DEBUG_VM
1894 static bool check_pcp_refill(struct page *page)
1899 static bool check_new_pcp(struct page *page)
1901 return check_new_page(page);
1904 static bool check_pcp_refill(struct page *page)
1906 return check_new_page(page);
1908 static bool check_new_pcp(struct page *page)
1912 #endif /* CONFIG_DEBUG_VM */
1914 static bool check_new_pages(struct page *page, unsigned int order)
1917 for (i = 0; i < (1 << order); i++) {
1918 struct page *p = page + i;
1920 if (unlikely(check_new_page(p)))
1927 inline void post_alloc_hook(struct page *page, unsigned int order,
1930 set_page_private(page, 0);
1931 set_page_refcounted(page);
1933 arch_alloc_page(page, order);
1934 kernel_map_pages(page, 1 << order, 1);
1935 kasan_alloc_pages(page, order);
1936 kernel_poison_pages(page, 1 << order, 1);
1937 set_page_owner(page, order, gfp_flags);
1940 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1941 unsigned int alloc_flags)
1945 post_alloc_hook(page, order, gfp_flags);
1947 if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO))
1948 for (i = 0; i < (1 << order); i++)
1949 clear_highpage(page + i);
1951 if (order && (gfp_flags & __GFP_COMP))
1952 prep_compound_page(page, order);
1955 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1956 * allocate the page. The expectation is that the caller is taking
1957 * steps that will free more memory. The caller should avoid the page
1958 * being used for !PFMEMALLOC purposes.
1960 if (alloc_flags & ALLOC_NO_WATERMARKS)
1961 set_page_pfmemalloc(page);
1963 clear_page_pfmemalloc(page);
1967 * Go through the free lists for the given migratetype and remove
1968 * the smallest available page from the freelists
1970 static __always_inline
1971 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1974 unsigned int current_order;
1975 struct free_area *area;
1978 /* Find a page of the appropriate size in the preferred list */
1979 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1980 area = &(zone->free_area[current_order]);
1981 page = list_first_entry_or_null(&area->free_list[migratetype],
1985 list_del(&page->lru);
1986 rmv_page_order(page);
1988 expand(zone, page, order, current_order, area, migratetype);
1989 set_pcppage_migratetype(page, migratetype);
1998 * This array describes the order lists are fallen back to when
1999 * the free lists for the desirable migrate type are depleted
2001 static int fallbacks[MIGRATE_TYPES][4] = {
2002 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2003 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
2004 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
2006 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
2008 #ifdef CONFIG_MEMORY_ISOLATION
2009 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
2014 static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2017 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
2020 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
2021 unsigned int order) { return NULL; }
2025 * Move the free pages in a range to the free lists of the requested type.
2026 * Note that start_page and end_pages are not aligned on a pageblock
2027 * boundary. If alignment is required, use move_freepages_block()
2029 static int move_freepages(struct zone *zone,
2030 struct page *start_page, struct page *end_page,
2031 int migratetype, int *num_movable)
2035 int pages_moved = 0;
2037 #ifndef CONFIG_HOLES_IN_ZONE
2039 * page_zone is not safe to call in this context when
2040 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
2041 * anyway as we check zone boundaries in move_freepages_block().
2042 * Remove at a later date when no bug reports exist related to
2043 * grouping pages by mobility
2045 VM_BUG_ON(pfn_valid(page_to_pfn(start_page)) &&
2046 pfn_valid(page_to_pfn(end_page)) &&
2047 page_zone(start_page) != page_zone(end_page));
2053 for (page = start_page; page <= end_page;) {
2054 if (!pfn_valid_within(page_to_pfn(page))) {
2059 /* Make sure we are not inadvertently changing nodes */
2060 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
2062 if (!PageBuddy(page)) {
2064 * We assume that pages that could be isolated for
2065 * migration are movable. But we don't actually try
2066 * isolating, as that would be expensive.
2069 (PageLRU(page) || __PageMovable(page)))
2076 order = page_order(page);
2077 list_move(&page->lru,
2078 &zone->free_area[order].free_list[migratetype]);
2080 pages_moved += 1 << order;
2086 int move_freepages_block(struct zone *zone, struct page *page,
2087 int migratetype, int *num_movable)
2089 unsigned long start_pfn, end_pfn;
2090 struct page *start_page, *end_page;
2092 start_pfn = page_to_pfn(page);
2093 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
2094 start_page = pfn_to_page(start_pfn);
2095 end_page = start_page + pageblock_nr_pages - 1;
2096 end_pfn = start_pfn + pageblock_nr_pages - 1;
2098 /* Do not cross zone boundaries */
2099 if (!zone_spans_pfn(zone, start_pfn))
2101 if (!zone_spans_pfn(zone, end_pfn))
2104 return move_freepages(zone, start_page, end_page, migratetype,
2108 static void change_pageblock_range(struct page *pageblock_page,
2109 int start_order, int migratetype)
2111 int nr_pageblocks = 1 << (start_order - pageblock_order);
2113 while (nr_pageblocks--) {
2114 set_pageblock_migratetype(pageblock_page, migratetype);
2115 pageblock_page += pageblock_nr_pages;
2120 * When we are falling back to another migratetype during allocation, try to
2121 * steal extra free pages from the same pageblocks to satisfy further
2122 * allocations, instead of polluting multiple pageblocks.
2124 * If we are stealing a relatively large buddy page, it is likely there will
2125 * be more free pages in the pageblock, so try to steal them all. For
2126 * reclaimable and unmovable allocations, we steal regardless of page size,
2127 * as fragmentation caused by those allocations polluting movable pageblocks
2128 * is worse than movable allocations stealing from unmovable and reclaimable
2131 static bool can_steal_fallback(unsigned int order, int start_mt)
2134 * Leaving this order check is intended, although there is
2135 * relaxed order check in next check. The reason is that
2136 * we can actually steal whole pageblock if this condition met,
2137 * but, below check doesn't guarantee it and that is just heuristic
2138 * so could be changed anytime.
2140 if (order >= pageblock_order)
2143 if (order >= pageblock_order / 2 ||
2144 start_mt == MIGRATE_RECLAIMABLE ||
2145 start_mt == MIGRATE_UNMOVABLE ||
2146 page_group_by_mobility_disabled)
2153 * This function implements actual steal behaviour. If order is large enough,
2154 * we can steal whole pageblock. If not, we first move freepages in this
2155 * pageblock to our migratetype and determine how many already-allocated pages
2156 * are there in the pageblock with a compatible migratetype. If at least half
2157 * of pages are free or compatible, we can change migratetype of the pageblock
2158 * itself, so pages freed in the future will be put on the correct free list.
2160 static void steal_suitable_fallback(struct zone *zone, struct page *page,
2161 int start_type, bool whole_block)
2163 unsigned int current_order = page_order(page);
2164 struct free_area *area;
2165 int free_pages, movable_pages, alike_pages;
2168 old_block_type = get_pageblock_migratetype(page);
2171 * This can happen due to races and we want to prevent broken
2172 * highatomic accounting.
2174 if (is_migrate_highatomic(old_block_type))
2177 /* Take ownership for orders >= pageblock_order */
2178 if (current_order >= pageblock_order) {
2179 change_pageblock_range(page, current_order, start_type);
2183 /* We are not allowed to try stealing from the whole block */
2187 free_pages = move_freepages_block(zone, page, start_type,
2190 * Determine how many pages are compatible with our allocation.
2191 * For movable allocation, it's the number of movable pages which
2192 * we just obtained. For other types it's a bit more tricky.
2194 if (start_type == MIGRATE_MOVABLE) {
2195 alike_pages = movable_pages;
2198 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2199 * to MOVABLE pageblock, consider all non-movable pages as
2200 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2201 * vice versa, be conservative since we can't distinguish the
2202 * exact migratetype of non-movable pages.
2204 if (old_block_type == MIGRATE_MOVABLE)
2205 alike_pages = pageblock_nr_pages
2206 - (free_pages + movable_pages);
2211 /* moving whole block can fail due to zone boundary conditions */
2216 * If a sufficient number of pages in the block are either free or of
2217 * comparable migratability as our allocation, claim the whole block.
2219 if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
2220 page_group_by_mobility_disabled)
2221 set_pageblock_migratetype(page, start_type);
2226 area = &zone->free_area[current_order];
2227 list_move(&page->lru, &area->free_list[start_type]);
2231 * Check whether there is a suitable fallback freepage with requested order.
2232 * If only_stealable is true, this function returns fallback_mt only if
2233 * we can steal other freepages all together. This would help to reduce
2234 * fragmentation due to mixed migratetype pages in one pageblock.
2236 int find_suitable_fallback(struct free_area *area, unsigned int order,
2237 int migratetype, bool only_stealable, bool *can_steal)
2242 if (area->nr_free == 0)
2247 fallback_mt = fallbacks[migratetype][i];
2248 if (fallback_mt == MIGRATE_TYPES)
2251 if (list_empty(&area->free_list[fallback_mt]))
2254 if (can_steal_fallback(order, migratetype))
2257 if (!only_stealable)
2268 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2269 * there are no empty page blocks that contain a page with a suitable order
2271 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2272 unsigned int alloc_order)
2275 unsigned long max_managed, flags;
2278 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2279 * Check is race-prone but harmless.
2281 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2282 if (zone->nr_reserved_highatomic >= max_managed)
2285 spin_lock_irqsave(&zone->lock, flags);
2287 /* Recheck the nr_reserved_highatomic limit under the lock */
2288 if (zone->nr_reserved_highatomic >= max_managed)
2292 mt = get_pageblock_migratetype(page);
2293 if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
2294 && !is_migrate_cma(mt)) {
2295 zone->nr_reserved_highatomic += pageblock_nr_pages;
2296 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2297 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
2301 spin_unlock_irqrestore(&zone->lock, flags);
2305 * Used when an allocation is about to fail under memory pressure. This
2306 * potentially hurts the reliability of high-order allocations when under
2307 * intense memory pressure but failed atomic allocations should be easier
2308 * to recover from than an OOM.
2310 * If @force is true, try to unreserve a pageblock even though highatomic
2311 * pageblock is exhausted.
2313 static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
2316 struct zonelist *zonelist = ac->zonelist;
2317 unsigned long flags;
2324 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2327 * Preserve at least one pageblock unless memory pressure
2330 if (!force && zone->nr_reserved_highatomic <=
2334 spin_lock_irqsave(&zone->lock, flags);
2335 for (order = 0; order < MAX_ORDER; order++) {
2336 struct free_area *area = &(zone->free_area[order]);
2338 page = list_first_entry_or_null(
2339 &area->free_list[MIGRATE_HIGHATOMIC],
2345 * In page freeing path, migratetype change is racy so
2346 * we can counter several free pages in a pageblock
2347 * in this loop althoug we changed the pageblock type
2348 * from highatomic to ac->migratetype. So we should
2349 * adjust the count once.
2351 if (is_migrate_highatomic_page(page)) {
2353 * It should never happen but changes to
2354 * locking could inadvertently allow a per-cpu
2355 * drain to add pages to MIGRATE_HIGHATOMIC
2356 * while unreserving so be safe and watch for
2359 zone->nr_reserved_highatomic -= min(
2361 zone->nr_reserved_highatomic);
2365 * Convert to ac->migratetype and avoid the normal
2366 * pageblock stealing heuristics. Minimally, the caller
2367 * is doing the work and needs the pages. More
2368 * importantly, if the block was always converted to
2369 * MIGRATE_UNMOVABLE or another type then the number
2370 * of pageblocks that cannot be completely freed
2373 set_pageblock_migratetype(page, ac->migratetype);
2374 ret = move_freepages_block(zone, page, ac->migratetype,
2377 spin_unlock_irqrestore(&zone->lock, flags);
2381 spin_unlock_irqrestore(&zone->lock, flags);
2388 * Try finding a free buddy page on the fallback list and put it on the free
2389 * list of requested migratetype, possibly along with other pages from the same
2390 * block, depending on fragmentation avoidance heuristics. Returns true if
2391 * fallback was found so that __rmqueue_smallest() can grab it.
2393 * The use of signed ints for order and current_order is a deliberate
2394 * deviation from the rest of this file, to make the for loop
2395 * condition simpler.
2397 static __always_inline bool
2398 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
2400 struct free_area *area;
2407 * Find the largest available free page in the other list. This roughly
2408 * approximates finding the pageblock with the most free pages, which
2409 * would be too costly to do exactly.
2411 for (current_order = MAX_ORDER - 1; current_order >= order;
2413 area = &(zone->free_area[current_order]);
2414 fallback_mt = find_suitable_fallback(area, current_order,
2415 start_migratetype, false, &can_steal);
2416 if (fallback_mt == -1)
2420 * We cannot steal all free pages from the pageblock and the
2421 * requested migratetype is movable. In that case it's better to
2422 * steal and split the smallest available page instead of the
2423 * largest available page, because even if the next movable
2424 * allocation falls back into a different pageblock than this
2425 * one, it won't cause permanent fragmentation.
2427 if (!can_steal && start_migratetype == MIGRATE_MOVABLE
2428 && current_order > order)
2437 for (current_order = order; current_order < MAX_ORDER;
2439 area = &(zone->free_area[current_order]);
2440 fallback_mt = find_suitable_fallback(area, current_order,
2441 start_migratetype, false, &can_steal);
2442 if (fallback_mt != -1)
2447 * This should not happen - we already found a suitable fallback
2448 * when looking for the largest page.
2450 VM_BUG_ON(current_order == MAX_ORDER);
2453 page = list_first_entry(&area->free_list[fallback_mt],
2456 steal_suitable_fallback(zone, page, start_migratetype, can_steal);
2458 trace_mm_page_alloc_extfrag(page, order, current_order,
2459 start_migratetype, fallback_mt);
2466 * Do the hard work of removing an element from the buddy allocator.
2467 * Call me with the zone->lock already held.
2469 static __always_inline struct page *
2470 __rmqueue(struct zone *zone, unsigned int order, int migratetype)
2475 page = __rmqueue_smallest(zone, order, migratetype);
2476 if (unlikely(!page)) {
2477 if (migratetype == MIGRATE_MOVABLE)
2478 page = __rmqueue_cma_fallback(zone, order);
2480 if (!page && __rmqueue_fallback(zone, order, migratetype))
2484 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2489 * Obtain a specified number of elements from the buddy allocator, all under
2490 * a single hold of the lock, for efficiency. Add them to the supplied list.
2491 * Returns the number of new pages which were placed at *list.
2493 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2494 unsigned long count, struct list_head *list,
2499 spin_lock(&zone->lock);
2500 for (i = 0; i < count; ++i) {
2501 struct page *page = __rmqueue(zone, order, migratetype);
2502 if (unlikely(page == NULL))
2505 if (unlikely(check_pcp_refill(page)))
2509 * Split buddy pages returned by expand() are received here in
2510 * physical page order. The page is added to the tail of
2511 * caller's list. From the callers perspective, the linked list
2512 * is ordered by page number under some conditions. This is
2513 * useful for IO devices that can forward direction from the
2514 * head, thus also in the physical page order. This is useful
2515 * for IO devices that can merge IO requests if the physical
2516 * pages are ordered properly.
2518 list_add_tail(&page->lru, list);
2520 if (is_migrate_cma(get_pcppage_migratetype(page)))
2521 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2526 * i pages were removed from the buddy list even if some leak due
2527 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2528 * on i. Do not confuse with 'alloced' which is the number of
2529 * pages added to the pcp list.
2531 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2532 spin_unlock(&zone->lock);
2538 * Called from the vmstat counter updater to drain pagesets of this
2539 * currently executing processor on remote nodes after they have
2542 * Note that this function must be called with the thread pinned to
2543 * a single processor.
2545 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2547 unsigned long flags;
2548 int to_drain, batch;
2550 local_irq_save(flags);
2551 batch = READ_ONCE(pcp->batch);
2552 to_drain = min(pcp->count, batch);
2554 free_pcppages_bulk(zone, to_drain, pcp);
2555 local_irq_restore(flags);
2560 * Drain pcplists of the indicated processor and zone.
2562 * The processor must either be the current processor and the
2563 * thread pinned to the current processor or a processor that
2566 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2568 unsigned long flags;
2569 struct per_cpu_pageset *pset;
2570 struct per_cpu_pages *pcp;
2572 local_irq_save(flags);
2573 pset = per_cpu_ptr(zone->pageset, cpu);
2577 free_pcppages_bulk(zone, pcp->count, pcp);
2578 local_irq_restore(flags);
2582 * Drain pcplists of all zones on the indicated processor.
2584 * The processor must either be the current processor and the
2585 * thread pinned to the current processor or a processor that
2588 static void drain_pages(unsigned int cpu)
2592 for_each_populated_zone(zone) {
2593 drain_pages_zone(cpu, zone);
2598 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2600 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2601 * the single zone's pages.
2603 void drain_local_pages(struct zone *zone)
2605 int cpu = smp_processor_id();
2608 drain_pages_zone(cpu, zone);
2613 static void drain_local_pages_wq(struct work_struct *work)
2616 * drain_all_pages doesn't use proper cpu hotplug protection so
2617 * we can race with cpu offline when the WQ can move this from
2618 * a cpu pinned worker to an unbound one. We can operate on a different
2619 * cpu which is allright but we also have to make sure to not move to
2623 drain_local_pages(NULL);
2628 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2630 * When zone parameter is non-NULL, spill just the single zone's pages.
2632 * Note that this can be extremely slow as the draining happens in a workqueue.
2634 void drain_all_pages(struct zone *zone)
2639 * Allocate in the BSS so we wont require allocation in
2640 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2642 static cpumask_t cpus_with_pcps;
2645 * Make sure nobody triggers this path before mm_percpu_wq is fully
2648 if (WARN_ON_ONCE(!mm_percpu_wq))
2652 * Do not drain if one is already in progress unless it's specific to
2653 * a zone. Such callers are primarily CMA and memory hotplug and need
2654 * the drain to be complete when the call returns.
2656 if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) {
2659 mutex_lock(&pcpu_drain_mutex);
2663 * We don't care about racing with CPU hotplug event
2664 * as offline notification will cause the notified
2665 * cpu to drain that CPU pcps and on_each_cpu_mask
2666 * disables preemption as part of its processing
2668 for_each_online_cpu(cpu) {
2669 struct per_cpu_pageset *pcp;
2671 bool has_pcps = false;
2674 pcp = per_cpu_ptr(zone->pageset, cpu);
2678 for_each_populated_zone(z) {
2679 pcp = per_cpu_ptr(z->pageset, cpu);
2680 if (pcp->pcp.count) {
2688 cpumask_set_cpu(cpu, &cpus_with_pcps);
2690 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2693 for_each_cpu(cpu, &cpus_with_pcps) {
2694 struct work_struct *work = per_cpu_ptr(&pcpu_drain, cpu);
2695 INIT_WORK(work, drain_local_pages_wq);
2696 queue_work_on(cpu, mm_percpu_wq, work);
2698 for_each_cpu(cpu, &cpus_with_pcps)
2699 flush_work(per_cpu_ptr(&pcpu_drain, cpu));
2701 mutex_unlock(&pcpu_drain_mutex);
2704 #ifdef CONFIG_HIBERNATION
2707 * Touch the watchdog for every WD_PAGE_COUNT pages.
2709 #define WD_PAGE_COUNT (128*1024)
2711 void mark_free_pages(struct zone *zone)
2713 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
2714 unsigned long flags;
2715 unsigned int order, t;
2718 if (zone_is_empty(zone))
2721 spin_lock_irqsave(&zone->lock, flags);
2723 max_zone_pfn = zone_end_pfn(zone);
2724 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2725 if (pfn_valid(pfn)) {
2726 page = pfn_to_page(pfn);
2728 if (!--page_count) {
2729 touch_nmi_watchdog();
2730 page_count = WD_PAGE_COUNT;
2733 if (page_zone(page) != zone)
2736 if (!swsusp_page_is_forbidden(page))
2737 swsusp_unset_page_free(page);
2740 for_each_migratetype_order(order, t) {
2741 list_for_each_entry(page,
2742 &zone->free_area[order].free_list[t], lru) {
2745 pfn = page_to_pfn(page);
2746 for (i = 0; i < (1UL << order); i++) {
2747 if (!--page_count) {
2748 touch_nmi_watchdog();
2749 page_count = WD_PAGE_COUNT;
2751 swsusp_set_page_free(pfn_to_page(pfn + i));
2755 spin_unlock_irqrestore(&zone->lock, flags);
2757 #endif /* CONFIG_PM */
2759 static bool free_unref_page_prepare(struct page *page, unsigned long pfn)
2763 if (!free_pcp_prepare(page))
2766 migratetype = get_pfnblock_migratetype(page, pfn);
2767 set_pcppage_migratetype(page, migratetype);
2771 static void free_unref_page_commit(struct page *page, unsigned long pfn)
2773 struct zone *zone = page_zone(page);
2774 struct per_cpu_pages *pcp;
2777 migratetype = get_pcppage_migratetype(page);
2778 __count_vm_event(PGFREE);
2781 * We only track unmovable, reclaimable and movable on pcp lists.
2782 * Free ISOLATE pages back to the allocator because they are being
2783 * offlined but treat HIGHATOMIC as movable pages so we can get those
2784 * areas back if necessary. Otherwise, we may have to free
2785 * excessively into the page allocator
2787 if (migratetype >= MIGRATE_PCPTYPES) {
2788 if (unlikely(is_migrate_isolate(migratetype))) {
2789 free_one_page(zone, page, pfn, 0, migratetype);
2792 migratetype = MIGRATE_MOVABLE;
2795 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2796 list_add(&page->lru, &pcp->lists[migratetype]);
2798 if (pcp->count >= pcp->high) {
2799 unsigned long batch = READ_ONCE(pcp->batch);
2800 free_pcppages_bulk(zone, batch, pcp);
2805 * Free a 0-order page
2807 void free_unref_page(struct page *page)
2809 unsigned long flags;
2810 unsigned long pfn = page_to_pfn(page);
2812 if (!free_unref_page_prepare(page, pfn))
2815 local_irq_save(flags);
2816 free_unref_page_commit(page, pfn);
2817 local_irq_restore(flags);
2821 * Free a list of 0-order pages
2823 void free_unref_page_list(struct list_head *list)
2825 struct page *page, *next;
2826 unsigned long flags, pfn;
2827 int batch_count = 0;
2829 /* Prepare pages for freeing */
2830 list_for_each_entry_safe(page, next, list, lru) {
2831 pfn = page_to_pfn(page);
2832 if (!free_unref_page_prepare(page, pfn))
2833 list_del(&page->lru);
2834 set_page_private(page, pfn);
2837 local_irq_save(flags);
2838 list_for_each_entry_safe(page, next, list, lru) {
2839 unsigned long pfn = page_private(page);
2841 set_page_private(page, 0);
2842 trace_mm_page_free_batched(page);
2843 free_unref_page_commit(page, pfn);
2846 * Guard against excessive IRQ disabled times when we get
2847 * a large list of pages to free.
2849 if (++batch_count == SWAP_CLUSTER_MAX) {
2850 local_irq_restore(flags);
2852 local_irq_save(flags);
2855 local_irq_restore(flags);
2859 * split_page takes a non-compound higher-order page, and splits it into
2860 * n (1<<order) sub-pages: page[0..n]
2861 * Each sub-page must be freed individually.
2863 * Note: this is probably too low level an operation for use in drivers.
2864 * Please consult with lkml before using this in your driver.
2866 void split_page(struct page *page, unsigned int order)
2870 VM_BUG_ON_PAGE(PageCompound(page), page);
2871 VM_BUG_ON_PAGE(!page_count(page), page);
2873 for (i = 1; i < (1 << order); i++)
2874 set_page_refcounted(page + i);
2875 split_page_owner(page, order);
2877 EXPORT_SYMBOL_GPL(split_page);
2879 int __isolate_free_page(struct page *page, unsigned int order)
2881 unsigned long watermark;
2885 BUG_ON(!PageBuddy(page));
2887 zone = page_zone(page);
2888 mt = get_pageblock_migratetype(page);
2890 if (!is_migrate_isolate(mt)) {
2892 * Obey watermarks as if the page was being allocated. We can
2893 * emulate a high-order watermark check with a raised order-0
2894 * watermark, because we already know our high-order page
2897 watermark = min_wmark_pages(zone) + (1UL << order);
2898 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
2901 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2904 /* Remove page from free list */
2905 list_del(&page->lru);
2906 zone->free_area[order].nr_free--;
2907 rmv_page_order(page);
2910 * Set the pageblock if the isolated page is at least half of a
2913 if (order >= pageblock_order - 1) {
2914 struct page *endpage = page + (1 << order) - 1;
2915 for (; page < endpage; page += pageblock_nr_pages) {
2916 int mt = get_pageblock_migratetype(page);
2917 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
2918 && !is_migrate_highatomic(mt))
2919 set_pageblock_migratetype(page,
2925 return 1UL << order;
2929 * Update NUMA hit/miss statistics
2931 * Must be called with interrupts disabled.
2933 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
2936 enum numa_stat_item local_stat = NUMA_LOCAL;
2938 /* skip numa counters update if numa stats is disabled */
2939 if (!static_branch_likely(&vm_numa_stat_key))
2942 if (zone_to_nid(z) != numa_node_id())
2943 local_stat = NUMA_OTHER;
2945 if (zone_to_nid(z) == zone_to_nid(preferred_zone))
2946 __inc_numa_state(z, NUMA_HIT);
2948 __inc_numa_state(z, NUMA_MISS);
2949 __inc_numa_state(preferred_zone, NUMA_FOREIGN);
2951 __inc_numa_state(z, local_stat);
2955 /* Remove page from the per-cpu list, caller must protect the list */
2956 static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
2957 struct per_cpu_pages *pcp,
2958 struct list_head *list)
2963 if (list_empty(list)) {
2964 pcp->count += rmqueue_bulk(zone, 0,
2967 if (unlikely(list_empty(list)))
2971 page = list_first_entry(list, struct page, lru);
2972 list_del(&page->lru);
2974 } while (check_new_pcp(page));
2979 /* Lock and remove page from the per-cpu list */
2980 static struct page *rmqueue_pcplist(struct zone *preferred_zone,
2981 struct zone *zone, unsigned int order,
2982 gfp_t gfp_flags, int migratetype)
2984 struct per_cpu_pages *pcp;
2985 struct list_head *list;
2987 unsigned long flags;
2989 local_irq_save(flags);
2990 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2991 list = &pcp->lists[migratetype];
2992 page = __rmqueue_pcplist(zone, migratetype, pcp, list);
2994 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
2995 zone_statistics(preferred_zone, zone);
2997 local_irq_restore(flags);
3002 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3005 struct page *rmqueue(struct zone *preferred_zone,
3006 struct zone *zone, unsigned int order,
3007 gfp_t gfp_flags, unsigned int alloc_flags,
3010 unsigned long flags;
3013 if (likely(order == 0)) {
3014 page = rmqueue_pcplist(preferred_zone, zone, order,
3015 gfp_flags, migratetype);
3020 * We most definitely don't want callers attempting to
3021 * allocate greater than order-1 page units with __GFP_NOFAIL.
3023 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
3024 spin_lock_irqsave(&zone->lock, flags);
3028 if (alloc_flags & ALLOC_HARDER) {
3029 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
3031 trace_mm_page_alloc_zone_locked(page, order, migratetype);
3034 page = __rmqueue(zone, order, migratetype);
3035 } while (page && check_new_pages(page, order));
3036 spin_unlock(&zone->lock);
3039 __mod_zone_freepage_state(zone, -(1 << order),
3040 get_pcppage_migratetype(page));
3042 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
3043 zone_statistics(preferred_zone, zone);
3044 local_irq_restore(flags);
3047 VM_BUG_ON_PAGE(page && bad_range(zone, page), page);
3051 local_irq_restore(flags);
3055 #ifdef CONFIG_FAIL_PAGE_ALLOC
3058 struct fault_attr attr;
3060 bool ignore_gfp_highmem;
3061 bool ignore_gfp_reclaim;
3063 } fail_page_alloc = {
3064 .attr = FAULT_ATTR_INITIALIZER,
3065 .ignore_gfp_reclaim = true,
3066 .ignore_gfp_highmem = true,
3070 static int __init setup_fail_page_alloc(char *str)
3072 return setup_fault_attr(&fail_page_alloc.attr, str);
3074 __setup("fail_page_alloc=", setup_fail_page_alloc);
3076 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3078 if (order < fail_page_alloc.min_order)
3080 if (gfp_mask & __GFP_NOFAIL)
3082 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
3084 if (fail_page_alloc.ignore_gfp_reclaim &&
3085 (gfp_mask & __GFP_DIRECT_RECLAIM))
3088 return should_fail(&fail_page_alloc.attr, 1 << order);
3091 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3093 static int __init fail_page_alloc_debugfs(void)
3095 umode_t mode = S_IFREG | 0600;
3098 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
3099 &fail_page_alloc.attr);
3101 return PTR_ERR(dir);
3103 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
3104 &fail_page_alloc.ignore_gfp_reclaim))
3106 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
3107 &fail_page_alloc.ignore_gfp_highmem))
3109 if (!debugfs_create_u32("min-order", mode, dir,
3110 &fail_page_alloc.min_order))
3115 debugfs_remove_recursive(dir);
3120 late_initcall(fail_page_alloc_debugfs);
3122 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3124 #else /* CONFIG_FAIL_PAGE_ALLOC */
3126 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
3131 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3134 * Return true if free base pages are above 'mark'. For high-order checks it
3135 * will return true of the order-0 watermark is reached and there is at least
3136 * one free page of a suitable size. Checking now avoids taking the zone lock
3137 * to check in the allocation paths if no pages are free.
3139 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3140 int classzone_idx, unsigned int alloc_flags,
3145 const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM));
3147 /* free_pages may go negative - that's OK */
3148 free_pages -= (1 << order) - 1;
3150 if (alloc_flags & ALLOC_HIGH)
3154 * If the caller does not have rights to ALLOC_HARDER then subtract
3155 * the high-atomic reserves. This will over-estimate the size of the
3156 * atomic reserve but it avoids a search.
3158 if (likely(!alloc_harder)) {
3159 free_pages -= z->nr_reserved_highatomic;
3162 * OOM victims can try even harder than normal ALLOC_HARDER
3163 * users on the grounds that it's definitely going to be in
3164 * the exit path shortly and free memory. Any allocation it
3165 * makes during the free path will be small and short-lived.
3167 if (alloc_flags & ALLOC_OOM)
3175 /* If allocation can't use CMA areas don't use free CMA pages */
3176 if (!(alloc_flags & ALLOC_CMA))
3177 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
3181 * Check watermarks for an order-0 allocation request. If these
3182 * are not met, then a high-order request also cannot go ahead
3183 * even if a suitable page happened to be free.
3185 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
3188 /* If this is an order-0 request then the watermark is fine */
3192 /* For a high-order request, check at least one suitable page is free */
3193 for (o = order; o < MAX_ORDER; o++) {
3194 struct free_area *area = &z->free_area[o];
3200 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
3201 if (!list_empty(&area->free_list[mt]))
3206 if ((alloc_flags & ALLOC_CMA) &&
3207 !list_empty(&area->free_list[MIGRATE_CMA])) {
3212 !list_empty(&area->free_list[MIGRATE_HIGHATOMIC]))
3218 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
3219 int classzone_idx, unsigned int alloc_flags)
3221 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
3222 zone_page_state(z, NR_FREE_PAGES));
3225 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
3226 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
3228 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3232 /* If allocation can't use CMA areas don't use free CMA pages */
3233 if (!(alloc_flags & ALLOC_CMA))
3234 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
3238 * Fast check for order-0 only. If this fails then the reserves
3239 * need to be calculated. There is a corner case where the check
3240 * passes but only the high-order atomic reserve are free. If
3241 * the caller is !atomic then it'll uselessly search the free
3242 * list. That corner case is then slower but it is harmless.
3244 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
3247 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
3251 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
3252 unsigned long mark, int classzone_idx)
3254 long free_pages = zone_page_state(z, NR_FREE_PAGES);
3256 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
3257 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
3259 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
3264 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3266 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <=
3269 #else /* CONFIG_NUMA */
3270 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
3274 #endif /* CONFIG_NUMA */
3277 * get_page_from_freelist goes through the zonelist trying to allocate
3280 static struct page *
3281 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
3282 const struct alloc_context *ac)
3284 struct zoneref *z = ac->preferred_zoneref;
3286 struct pglist_data *last_pgdat_dirty_limit = NULL;
3289 * Scan zonelist, looking for a zone with enough free.
3290 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3292 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3297 if (cpusets_enabled() &&
3298 (alloc_flags & ALLOC_CPUSET) &&
3299 !__cpuset_zone_allowed(zone, gfp_mask))
3302 * When allocating a page cache page for writing, we
3303 * want to get it from a node that is within its dirty
3304 * limit, such that no single node holds more than its
3305 * proportional share of globally allowed dirty pages.
3306 * The dirty limits take into account the node's
3307 * lowmem reserves and high watermark so that kswapd
3308 * should be able to balance it without having to
3309 * write pages from its LRU list.
3311 * XXX: For now, allow allocations to potentially
3312 * exceed the per-node dirty limit in the slowpath
3313 * (spread_dirty_pages unset) before going into reclaim,
3314 * which is important when on a NUMA setup the allowed
3315 * nodes are together not big enough to reach the
3316 * global limit. The proper fix for these situations
3317 * will require awareness of nodes in the
3318 * dirty-throttling and the flusher threads.
3320 if (ac->spread_dirty_pages) {
3321 if (last_pgdat_dirty_limit == zone->zone_pgdat)
3324 if (!node_dirty_ok(zone->zone_pgdat)) {
3325 last_pgdat_dirty_limit = zone->zone_pgdat;
3330 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
3331 if (!zone_watermark_fast(zone, order, mark,
3332 ac_classzone_idx(ac), alloc_flags)) {
3335 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3337 * Watermark failed for this zone, but see if we can
3338 * grow this zone if it contains deferred pages.
3340 if (static_branch_unlikely(&deferred_pages)) {
3341 if (_deferred_grow_zone(zone, order))
3345 /* Checked here to keep the fast path fast */
3346 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
3347 if (alloc_flags & ALLOC_NO_WATERMARKS)
3350 if (node_reclaim_mode == 0 ||
3351 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
3354 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
3356 case NODE_RECLAIM_NOSCAN:
3359 case NODE_RECLAIM_FULL:
3360 /* scanned but unreclaimable */
3363 /* did we reclaim enough */
3364 if (zone_watermark_ok(zone, order, mark,
3365 ac_classzone_idx(ac), alloc_flags))
3373 page = rmqueue(ac->preferred_zoneref->zone, zone, order,
3374 gfp_mask, alloc_flags, ac->migratetype);
3376 prep_new_page(page, order, gfp_mask, alloc_flags);
3379 * If this is a high-order atomic allocation then check
3380 * if the pageblock should be reserved for the future
3382 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3383 reserve_highatomic_pageblock(page, zone, order);
3387 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3388 /* Try again if zone has deferred pages */
3389 if (static_branch_unlikely(&deferred_pages)) {
3390 if (_deferred_grow_zone(zone, order))
3401 * Large machines with many possible nodes should not always dump per-node
3402 * meminfo in irq context.
3404 static inline bool should_suppress_show_mem(void)
3409 ret = in_interrupt();
3414 static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
3416 unsigned int filter = SHOW_MEM_FILTER_NODES;
3417 static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1);
3419 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs))
3423 * This documents exceptions given to allocations in certain
3424 * contexts that are allowed to allocate outside current's set
3427 if (!(gfp_mask & __GFP_NOMEMALLOC))
3428 if (tsk_is_oom_victim(current) ||
3429 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3430 filter &= ~SHOW_MEM_FILTER_NODES;
3431 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3432 filter &= ~SHOW_MEM_FILTER_NODES;
3434 show_mem(filter, nodemask);
3437 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
3439 struct va_format vaf;
3441 static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL,
3442 DEFAULT_RATELIMIT_BURST);
3444 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
3447 va_start(args, fmt);
3450 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl\n",
3451 current->comm, &vaf, gfp_mask, &gfp_mask,
3452 nodemask_pr_args(nodemask));
3455 cpuset_print_current_mems_allowed();
3458 warn_alloc_show_mem(gfp_mask, nodemask);
3461 static inline struct page *
3462 __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
3463 unsigned int alloc_flags,
3464 const struct alloc_context *ac)
3468 page = get_page_from_freelist(gfp_mask, order,
3469 alloc_flags|ALLOC_CPUSET, ac);
3471 * fallback to ignore cpuset restriction if our nodes
3475 page = get_page_from_freelist(gfp_mask, order,
3481 static inline struct page *
3482 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3483 const struct alloc_context *ac, unsigned long *did_some_progress)
3485 struct oom_control oc = {
3486 .zonelist = ac->zonelist,
3487 .nodemask = ac->nodemask,
3489 .gfp_mask = gfp_mask,
3494 *did_some_progress = 0;
3497 * Acquire the oom lock. If that fails, somebody else is
3498 * making progress for us.
3500 if (!mutex_trylock(&oom_lock)) {
3501 *did_some_progress = 1;
3502 schedule_timeout_uninterruptible(1);
3507 * Go through the zonelist yet one more time, keep very high watermark
3508 * here, this is only to catch a parallel oom killing, we must fail if
3509 * we're still under heavy pressure. But make sure that this reclaim
3510 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3511 * allocation which will never fail due to oom_lock already held.
3513 page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
3514 ~__GFP_DIRECT_RECLAIM, order,
3515 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3519 /* Coredumps can quickly deplete all memory reserves */
3520 if (current->flags & PF_DUMPCORE)
3522 /* The OOM killer will not help higher order allocs */
3523 if (order > PAGE_ALLOC_COSTLY_ORDER)
3526 * We have already exhausted all our reclaim opportunities without any
3527 * success so it is time to admit defeat. We will skip the OOM killer
3528 * because it is very likely that the caller has a more reasonable
3529 * fallback than shooting a random task.
3531 if (gfp_mask & __GFP_RETRY_MAYFAIL)
3533 /* The OOM killer does not needlessly kill tasks for lowmem */
3534 if (ac->high_zoneidx < ZONE_NORMAL)
3536 if (pm_suspended_storage())
3539 * XXX: GFP_NOFS allocations should rather fail than rely on
3540 * other request to make a forward progress.
3541 * We are in an unfortunate situation where out_of_memory cannot
3542 * do much for this context but let's try it to at least get
3543 * access to memory reserved if the current task is killed (see
3544 * out_of_memory). Once filesystems are ready to handle allocation
3545 * failures more gracefully we should just bail out here.
3548 /* The OOM killer may not free memory on a specific node */
3549 if (gfp_mask & __GFP_THISNODE)
3552 /* Exhausted what can be done so it's blame time */
3553 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3554 *did_some_progress = 1;
3557 * Help non-failing allocations by giving them access to memory
3560 if (gfp_mask & __GFP_NOFAIL)
3561 page = __alloc_pages_cpuset_fallback(gfp_mask, order,
3562 ALLOC_NO_WATERMARKS, ac);
3565 mutex_unlock(&oom_lock);
3570 * Maximum number of compaction retries wit a progress before OOM
3571 * killer is consider as the only way to move forward.
3573 #define MAX_COMPACT_RETRIES 16
3575 #ifdef CONFIG_COMPACTION
3576 /* Try memory compaction for high-order allocations before reclaim */
3577 static struct page *
3578 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3579 unsigned int alloc_flags, const struct alloc_context *ac,
3580 enum compact_priority prio, enum compact_result *compact_result)
3583 unsigned int noreclaim_flag;
3588 noreclaim_flag = memalloc_noreclaim_save();
3589 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3591 memalloc_noreclaim_restore(noreclaim_flag);
3593 if (*compact_result <= COMPACT_INACTIVE)
3597 * At least in one zone compaction wasn't deferred or skipped, so let's
3598 * count a compaction stall
3600 count_vm_event(COMPACTSTALL);
3602 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3605 struct zone *zone = page_zone(page);
3607 zone->compact_blockskip_flush = false;
3608 compaction_defer_reset(zone, order, true);
3609 count_vm_event(COMPACTSUCCESS);
3614 * It's bad if compaction run occurs and fails. The most likely reason
3615 * is that pages exist, but not enough to satisfy watermarks.
3617 count_vm_event(COMPACTFAIL);
3625 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3626 enum compact_result compact_result,
3627 enum compact_priority *compact_priority,
3628 int *compaction_retries)
3630 int max_retries = MAX_COMPACT_RETRIES;
3633 int retries = *compaction_retries;
3634 enum compact_priority priority = *compact_priority;
3639 if (compaction_made_progress(compact_result))
3640 (*compaction_retries)++;
3643 * compaction considers all the zone as desperately out of memory
3644 * so it doesn't really make much sense to retry except when the
3645 * failure could be caused by insufficient priority
3647 if (compaction_failed(compact_result))
3648 goto check_priority;
3651 * make sure the compaction wasn't deferred or didn't bail out early
3652 * due to locks contention before we declare that we should give up.
3653 * But do not retry if the given zonelist is not suitable for
3656 if (compaction_withdrawn(compact_result)) {
3657 ret = compaction_zonelist_suitable(ac, order, alloc_flags);
3662 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3663 * costly ones because they are de facto nofail and invoke OOM
3664 * killer to move on while costly can fail and users are ready
3665 * to cope with that. 1/4 retries is rather arbitrary but we
3666 * would need much more detailed feedback from compaction to
3667 * make a better decision.
3669 if (order > PAGE_ALLOC_COSTLY_ORDER)
3671 if (*compaction_retries <= max_retries) {
3677 * Make sure there are attempts at the highest priority if we exhausted
3678 * all retries or failed at the lower priorities.
3681 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
3682 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
3684 if (*compact_priority > min_priority) {
3685 (*compact_priority)--;
3686 *compaction_retries = 0;
3690 trace_compact_retry(order, priority, compact_result, retries, max_retries, ret);
3694 static inline struct page *
3695 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3696 unsigned int alloc_flags, const struct alloc_context *ac,
3697 enum compact_priority prio, enum compact_result *compact_result)
3699 *compact_result = COMPACT_SKIPPED;
3704 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3705 enum compact_result compact_result,
3706 enum compact_priority *compact_priority,
3707 int *compaction_retries)
3712 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
3716 * There are setups with compaction disabled which would prefer to loop
3717 * inside the allocator rather than hit the oom killer prematurely.
3718 * Let's give them a good hope and keep retrying while the order-0
3719 * watermarks are OK.
3721 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3723 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
3724 ac_classzone_idx(ac), alloc_flags))
3729 #endif /* CONFIG_COMPACTION */
3731 #ifdef CONFIG_LOCKDEP
3732 static struct lockdep_map __fs_reclaim_map =
3733 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map);
3735 static bool __need_fs_reclaim(gfp_t gfp_mask)
3737 gfp_mask = current_gfp_context(gfp_mask);
3739 /* no reclaim without waiting on it */
3740 if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
3743 /* this guy won't enter reclaim */
3744 if (current->flags & PF_MEMALLOC)
3747 /* We're only interested __GFP_FS allocations for now */
3748 if (!(gfp_mask & __GFP_FS))
3751 if (gfp_mask & __GFP_NOLOCKDEP)
3757 void __fs_reclaim_acquire(void)
3759 lock_map_acquire(&__fs_reclaim_map);
3762 void __fs_reclaim_release(void)
3764 lock_map_release(&__fs_reclaim_map);
3767 void fs_reclaim_acquire(gfp_t gfp_mask)
3769 if (__need_fs_reclaim(gfp_mask))
3770 __fs_reclaim_acquire();
3772 EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
3774 void fs_reclaim_release(gfp_t gfp_mask)
3776 if (__need_fs_reclaim(gfp_mask))
3777 __fs_reclaim_release();
3779 EXPORT_SYMBOL_GPL(fs_reclaim_release);
3782 /* Perform direct synchronous page reclaim */
3784 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3785 const struct alloc_context *ac)
3787 struct reclaim_state reclaim_state;
3789 unsigned int noreclaim_flag;
3793 /* We now go into synchronous reclaim */
3794 cpuset_memory_pressure_bump();
3795 fs_reclaim_acquire(gfp_mask);
3796 noreclaim_flag = memalloc_noreclaim_save();
3797 reclaim_state.reclaimed_slab = 0;
3798 current->reclaim_state = &reclaim_state;
3800 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3803 current->reclaim_state = NULL;
3804 memalloc_noreclaim_restore(noreclaim_flag);
3805 fs_reclaim_release(gfp_mask);
3812 /* The really slow allocator path where we enter direct reclaim */
3813 static inline struct page *
3814 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3815 unsigned int alloc_flags, const struct alloc_context *ac,
3816 unsigned long *did_some_progress)
3818 struct page *page = NULL;
3819 bool drained = false;
3821 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3822 if (unlikely(!(*did_some_progress)))
3826 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3829 * If an allocation failed after direct reclaim, it could be because
3830 * pages are pinned on the per-cpu lists or in high alloc reserves.
3831 * Shrink them them and try again
3833 if (!page && !drained) {
3834 unreserve_highatomic_pageblock(ac, false);
3835 drain_all_pages(NULL);
3843 static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
3844 const struct alloc_context *ac)
3848 pg_data_t *last_pgdat = NULL;
3849 enum zone_type high_zoneidx = ac->high_zoneidx;
3851 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, high_zoneidx,
3853 if (last_pgdat != zone->zone_pgdat)
3854 wakeup_kswapd(zone, gfp_mask, order, high_zoneidx);
3855 last_pgdat = zone->zone_pgdat;
3859 static inline unsigned int
3860 gfp_to_alloc_flags(gfp_t gfp_mask)
3862 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3864 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3865 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3868 * The caller may dip into page reserves a bit more if the caller
3869 * cannot run direct reclaim, or if the caller has realtime scheduling
3870 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3871 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3873 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3875 if (gfp_mask & __GFP_ATOMIC) {
3877 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3878 * if it can't schedule.
3880 if (!(gfp_mask & __GFP_NOMEMALLOC))
3881 alloc_flags |= ALLOC_HARDER;
3883 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3884 * comment for __cpuset_node_allowed().
3886 alloc_flags &= ~ALLOC_CPUSET;
3887 } else if (unlikely(rt_task(current)) && !in_interrupt())
3888 alloc_flags |= ALLOC_HARDER;
3891 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3892 alloc_flags |= ALLOC_CMA;
3897 static bool oom_reserves_allowed(struct task_struct *tsk)
3899 if (!tsk_is_oom_victim(tsk))
3903 * !MMU doesn't have oom reaper so give access to memory reserves
3904 * only to the thread with TIF_MEMDIE set
3906 if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE))
3913 * Distinguish requests which really need access to full memory
3914 * reserves from oom victims which can live with a portion of it
3916 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask)
3918 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
3920 if (gfp_mask & __GFP_MEMALLOC)
3921 return ALLOC_NO_WATERMARKS;
3922 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3923 return ALLOC_NO_WATERMARKS;
3924 if (!in_interrupt()) {
3925 if (current->flags & PF_MEMALLOC)
3926 return ALLOC_NO_WATERMARKS;
3927 else if (oom_reserves_allowed(current))
3934 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3936 return !!__gfp_pfmemalloc_flags(gfp_mask);
3940 * Checks whether it makes sense to retry the reclaim to make a forward progress
3941 * for the given allocation request.
3943 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3944 * without success, or when we couldn't even meet the watermark if we
3945 * reclaimed all remaining pages on the LRU lists.
3947 * Returns true if a retry is viable or false to enter the oom path.
3950 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3951 struct alloc_context *ac, int alloc_flags,
3952 bool did_some_progress, int *no_progress_loops)
3958 * Costly allocations might have made a progress but this doesn't mean
3959 * their order will become available due to high fragmentation so
3960 * always increment the no progress counter for them
3962 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3963 *no_progress_loops = 0;
3965 (*no_progress_loops)++;
3968 * Make sure we converge to OOM if we cannot make any progress
3969 * several times in the row.
3971 if (*no_progress_loops > MAX_RECLAIM_RETRIES) {
3972 /* Before OOM, exhaust highatomic_reserve */
3973 return unreserve_highatomic_pageblock(ac, true);
3977 * Keep reclaiming pages while there is a chance this will lead
3978 * somewhere. If none of the target zones can satisfy our allocation
3979 * request even if all reclaimable pages are considered then we are
3980 * screwed and have to go OOM.
3982 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3984 unsigned long available;
3985 unsigned long reclaimable;
3986 unsigned long min_wmark = min_wmark_pages(zone);
3989 available = reclaimable = zone_reclaimable_pages(zone);
3990 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3993 * Would the allocation succeed if we reclaimed all
3994 * reclaimable pages?
3996 wmark = __zone_watermark_ok(zone, order, min_wmark,
3997 ac_classzone_idx(ac), alloc_flags, available);
3998 trace_reclaim_retry_zone(z, order, reclaimable,
3999 available, min_wmark, *no_progress_loops, wmark);
4002 * If we didn't make any progress and have a lot of
4003 * dirty + writeback pages then we should wait for
4004 * an IO to complete to slow down the reclaim and
4005 * prevent from pre mature OOM
4007 if (!did_some_progress) {
4008 unsigned long write_pending;
4010 write_pending = zone_page_state_snapshot(zone,
4011 NR_ZONE_WRITE_PENDING);
4013 if (2 * write_pending > reclaimable) {
4014 congestion_wait(BLK_RW_ASYNC, HZ/10);
4020 * Memory allocation/reclaim might be called from a WQ
4021 * context and the current implementation of the WQ
4022 * concurrency control doesn't recognize that
4023 * a particular WQ is congested if the worker thread is
4024 * looping without ever sleeping. Therefore we have to
4025 * do a short sleep here rather than calling
4028 if (current->flags & PF_WQ_WORKER)
4029 schedule_timeout_uninterruptible(1);
4041 check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
4044 * It's possible that cpuset's mems_allowed and the nodemask from
4045 * mempolicy don't intersect. This should be normally dealt with by
4046 * policy_nodemask(), but it's possible to race with cpuset update in
4047 * such a way the check therein was true, and then it became false
4048 * before we got our cpuset_mems_cookie here.
4049 * This assumes that for all allocations, ac->nodemask can come only
4050 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4051 * when it does not intersect with the cpuset restrictions) or the
4052 * caller can deal with a violated nodemask.
4054 if (cpusets_enabled() && ac->nodemask &&
4055 !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) {
4056 ac->nodemask = NULL;
4061 * When updating a task's mems_allowed or mempolicy nodemask, it is
4062 * possible to race with parallel threads in such a way that our
4063 * allocation can fail while the mask is being updated. If we are about
4064 * to fail, check if the cpuset changed during allocation and if so,
4067 if (read_mems_allowed_retry(cpuset_mems_cookie))
4073 static inline struct page *
4074 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
4075 struct alloc_context *ac)
4077 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
4078 const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
4079 struct page *page = NULL;
4080 unsigned int alloc_flags;
4081 unsigned long did_some_progress;
4082 enum compact_priority compact_priority;
4083 enum compact_result compact_result;
4084 int compaction_retries;
4085 int no_progress_loops;
4086 unsigned int cpuset_mems_cookie;
4090 * We also sanity check to catch abuse of atomic reserves being used by
4091 * callers that are not in atomic context.
4093 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
4094 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
4095 gfp_mask &= ~__GFP_ATOMIC;
4098 compaction_retries = 0;
4099 no_progress_loops = 0;
4100 compact_priority = DEF_COMPACT_PRIORITY;
4101 cpuset_mems_cookie = read_mems_allowed_begin();
4104 * The fast path uses conservative alloc_flags to succeed only until
4105 * kswapd needs to be woken up, and to avoid the cost of setting up
4106 * alloc_flags precisely. So we do that now.
4108 alloc_flags = gfp_to_alloc_flags(gfp_mask);
4111 * We need to recalculate the starting point for the zonelist iterator
4112 * because we might have used different nodemask in the fast path, or
4113 * there was a cpuset modification and we are retrying - otherwise we
4114 * could end up iterating over non-eligible zones endlessly.
4116 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4117 ac->high_zoneidx, ac->nodemask);
4118 if (!ac->preferred_zoneref->zone)
4121 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
4122 wake_all_kswapds(order, gfp_mask, ac);
4125 * The adjusted alloc_flags might result in immediate success, so try
4128 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4133 * For costly allocations, try direct compaction first, as it's likely
4134 * that we have enough base pages and don't need to reclaim. For non-
4135 * movable high-order allocations, do that as well, as compaction will
4136 * try prevent permanent fragmentation by migrating from blocks of the
4138 * Don't try this for allocations that are allowed to ignore
4139 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4141 if (can_direct_reclaim &&
4143 (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
4144 && !gfp_pfmemalloc_allowed(gfp_mask)) {
4145 page = __alloc_pages_direct_compact(gfp_mask, order,
4147 INIT_COMPACT_PRIORITY,
4153 * Checks for costly allocations with __GFP_NORETRY, which
4154 * includes THP page fault allocations
4156 if (costly_order && (gfp_mask & __GFP_NORETRY)) {
4158 * If compaction is deferred for high-order allocations,
4159 * it is because sync compaction recently failed. If
4160 * this is the case and the caller requested a THP
4161 * allocation, we do not want to heavily disrupt the
4162 * system, so we fail the allocation instead of entering
4165 if (compact_result == COMPACT_DEFERRED)
4169 * Looks like reclaim/compaction is worth trying, but
4170 * sync compaction could be very expensive, so keep
4171 * using async compaction.
4173 compact_priority = INIT_COMPACT_PRIORITY;
4178 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4179 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
4180 wake_all_kswapds(order, gfp_mask, ac);
4182 reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
4184 alloc_flags = reserve_flags;
4187 * Reset the nodemask and zonelist iterators if memory policies can be
4188 * ignored. These allocations are high priority and system rather than
4191 if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
4192 ac->nodemask = NULL;
4193 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4194 ac->high_zoneidx, ac->nodemask);
4197 /* Attempt with potentially adjusted zonelist and alloc_flags */
4198 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
4202 /* Caller is not willing to reclaim, we can't balance anything */
4203 if (!can_direct_reclaim)
4206 /* Avoid recursion of direct reclaim */
4207 if (current->flags & PF_MEMALLOC)
4210 /* Try direct reclaim and then allocating */
4211 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
4212 &did_some_progress);
4216 /* Try direct compaction and then allocating */
4217 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
4218 compact_priority, &compact_result);
4222 /* Do not loop if specifically requested */
4223 if (gfp_mask & __GFP_NORETRY)
4227 * Do not retry costly high order allocations unless they are
4228 * __GFP_RETRY_MAYFAIL
4230 if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL))
4233 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
4234 did_some_progress > 0, &no_progress_loops))
4238 * It doesn't make any sense to retry for the compaction if the order-0
4239 * reclaim is not able to make any progress because the current
4240 * implementation of the compaction depends on the sufficient amount
4241 * of free memory (see __compaction_suitable)
4243 if (did_some_progress > 0 &&
4244 should_compact_retry(ac, order, alloc_flags,
4245 compact_result, &compact_priority,
4246 &compaction_retries))
4250 /* Deal with possible cpuset update races before we start OOM killing */
4251 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4254 /* Reclaim has failed us, start killing things */
4255 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
4259 /* Avoid allocations with no watermarks from looping endlessly */
4260 if (tsk_is_oom_victim(current) &&
4261 (alloc_flags == ALLOC_OOM ||
4262 (gfp_mask & __GFP_NOMEMALLOC)))
4265 /* Retry as long as the OOM killer is making progress */
4266 if (did_some_progress) {
4267 no_progress_loops = 0;
4272 /* Deal with possible cpuset update races before we fail */
4273 if (check_retry_cpuset(cpuset_mems_cookie, ac))
4277 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4280 if (gfp_mask & __GFP_NOFAIL) {
4282 * All existing users of the __GFP_NOFAIL are blockable, so warn
4283 * of any new users that actually require GFP_NOWAIT
4285 if (WARN_ON_ONCE(!can_direct_reclaim))
4289 * PF_MEMALLOC request from this context is rather bizarre
4290 * because we cannot reclaim anything and only can loop waiting
4291 * for somebody to do a work for us
4293 WARN_ON_ONCE(current->flags & PF_MEMALLOC);
4296 * non failing costly orders are a hard requirement which we
4297 * are not prepared for much so let's warn about these users
4298 * so that we can identify them and convert them to something
4301 WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
4304 * Help non-failing allocations by giving them access to memory
4305 * reserves but do not use ALLOC_NO_WATERMARKS because this
4306 * could deplete whole memory reserves which would just make
4307 * the situation worse
4309 page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac);
4317 warn_alloc(gfp_mask, ac->nodemask,
4318 "page allocation failure: order:%u", order);
4323 static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
4324 int preferred_nid, nodemask_t *nodemask,
4325 struct alloc_context *ac, gfp_t *alloc_mask,
4326 unsigned int *alloc_flags)
4328 ac->high_zoneidx = gfp_zone(gfp_mask);
4329 ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
4330 ac->nodemask = nodemask;
4331 ac->migratetype = gfpflags_to_migratetype(gfp_mask);
4333 if (cpusets_enabled()) {
4334 *alloc_mask |= __GFP_HARDWALL;
4336 ac->nodemask = &cpuset_current_mems_allowed;
4338 *alloc_flags |= ALLOC_CPUSET;
4341 fs_reclaim_acquire(gfp_mask);
4342 fs_reclaim_release(gfp_mask);
4344 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
4346 if (should_fail_alloc_page(gfp_mask, order))
4349 if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE)
4350 *alloc_flags |= ALLOC_CMA;
4355 /* Determine whether to spread dirty pages and what the first usable zone */
4356 static inline void finalise_ac(gfp_t gfp_mask, struct alloc_context *ac)
4358 /* Dirty zone balancing only done in the fast path */
4359 ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
4362 * The preferred zone is used for statistics but crucially it is
4363 * also used as the starting point for the zonelist iterator. It
4364 * may get reset for allocations that ignore memory policies.
4366 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
4367 ac->high_zoneidx, ac->nodemask);
4371 * This is the 'heart' of the zoned buddy allocator.
4374 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
4375 nodemask_t *nodemask)
4378 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4379 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
4380 struct alloc_context ac = { };
4383 * There are several places where we assume that the order value is sane
4384 * so bail out early if the request is out of bound.
4386 if (unlikely(order >= MAX_ORDER)) {
4387 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4391 gfp_mask &= gfp_allowed_mask;
4392 alloc_mask = gfp_mask;
4393 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
4396 finalise_ac(gfp_mask, &ac);
4398 /* First allocation attempt */
4399 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
4404 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4405 * resp. GFP_NOIO which has to be inherited for all allocation requests
4406 * from a particular context which has been marked by
4407 * memalloc_no{fs,io}_{save,restore}.
4409 alloc_mask = current_gfp_context(gfp_mask);
4410 ac.spread_dirty_pages = false;
4413 * Restore the original nodemask if it was potentially replaced with
4414 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4416 if (unlikely(ac.nodemask != nodemask))
4417 ac.nodemask = nodemask;
4419 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
4422 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
4423 unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
4424 __free_pages(page, order);
4428 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
4432 EXPORT_SYMBOL(__alloc_pages_nodemask);
4435 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
4436 * address cannot represent highmem pages. Use alloc_pages and then kmap if
4437 * you need to access high mem.
4439 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
4443 page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order);
4446 return (unsigned long) page_address(page);
4448 EXPORT_SYMBOL(__get_free_pages);
4450 unsigned long get_zeroed_page(gfp_t gfp_mask)
4452 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
4454 EXPORT_SYMBOL(get_zeroed_page);
4456 static inline void free_the_page(struct page *page, unsigned int order)
4458 if (order == 0) /* Via pcp? */
4459 free_unref_page(page);
4461 __free_pages_ok(page, order);
4464 void __free_pages(struct page *page, unsigned int order)
4466 if (put_page_testzero(page))
4467 free_the_page(page, order);
4469 EXPORT_SYMBOL(__free_pages);
4471 void free_pages(unsigned long addr, unsigned int order)
4474 VM_BUG_ON(!virt_addr_valid((void *)addr));
4475 __free_pages(virt_to_page((void *)addr), order);
4479 EXPORT_SYMBOL(free_pages);
4483 * An arbitrary-length arbitrary-offset area of memory which resides
4484 * within a 0 or higher order page. Multiple fragments within that page
4485 * are individually refcounted, in the page's reference counter.
4487 * The page_frag functions below provide a simple allocation framework for
4488 * page fragments. This is used by the network stack and network device
4489 * drivers to provide a backing region of memory for use as either an
4490 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4492 static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
4495 struct page *page = NULL;
4496 gfp_t gfp = gfp_mask;
4498 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4499 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
4501 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
4502 PAGE_FRAG_CACHE_MAX_ORDER);
4503 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
4505 if (unlikely(!page))
4506 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
4508 nc->va = page ? page_address(page) : NULL;
4513 void __page_frag_cache_drain(struct page *page, unsigned int count)
4515 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
4517 if (page_ref_sub_and_test(page, count))
4518 free_the_page(page, compound_order(page));
4520 EXPORT_SYMBOL(__page_frag_cache_drain);
4522 void *page_frag_alloc(struct page_frag_cache *nc,
4523 unsigned int fragsz, gfp_t gfp_mask)
4525 unsigned int size = PAGE_SIZE;
4529 if (unlikely(!nc->va)) {
4531 page = __page_frag_cache_refill(nc, gfp_mask);
4535 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4536 /* if size can vary use size else just use PAGE_SIZE */
4539 /* Even if we own the page, we do not use atomic_set().
4540 * This would break get_page_unless_zero() users.
4542 page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE);
4544 /* reset page count bias and offset to start of new frag */
4545 nc->pfmemalloc = page_is_pfmemalloc(page);
4546 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
4550 offset = nc->offset - fragsz;
4551 if (unlikely(offset < 0)) {
4552 page = virt_to_page(nc->va);
4554 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
4557 if (unlikely(nc->pfmemalloc)) {
4558 free_the_page(page, compound_order(page));
4562 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4563 /* if size can vary use size else just use PAGE_SIZE */
4566 /* OK, page count is 0, we can safely set it */
4567 set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1);
4569 /* reset page count bias and offset to start of new frag */
4570 nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
4571 offset = size - fragsz;
4575 nc->offset = offset;
4577 return nc->va + offset;
4579 EXPORT_SYMBOL(page_frag_alloc);
4582 * Frees a page fragment allocated out of either a compound or order 0 page.
4584 void page_frag_free(void *addr)
4586 struct page *page = virt_to_head_page(addr);
4588 if (unlikely(put_page_testzero(page)))
4589 free_the_page(page, compound_order(page));
4591 EXPORT_SYMBOL(page_frag_free);
4593 static void *make_alloc_exact(unsigned long addr, unsigned int order,
4597 unsigned long alloc_end = addr + (PAGE_SIZE << order);
4598 unsigned long used = addr + PAGE_ALIGN(size);
4600 split_page(virt_to_page((void *)addr), order);
4601 while (used < alloc_end) {
4606 return (void *)addr;
4610 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4611 * @size: the number of bytes to allocate
4612 * @gfp_mask: GFP flags for the allocation
4614 * This function is similar to alloc_pages(), except that it allocates the
4615 * minimum number of pages to satisfy the request. alloc_pages() can only
4616 * allocate memory in power-of-two pages.
4618 * This function is also limited by MAX_ORDER.
4620 * Memory allocated by this function must be released by free_pages_exact().
4622 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
4624 unsigned int order = get_order(size);
4627 addr = __get_free_pages(gfp_mask, order);
4628 return make_alloc_exact(addr, order, size);
4630 EXPORT_SYMBOL(alloc_pages_exact);
4633 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4635 * @nid: the preferred node ID where memory should be allocated
4636 * @size: the number of bytes to allocate
4637 * @gfp_mask: GFP flags for the allocation
4639 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4642 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4644 unsigned int order = get_order(size);
4645 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4648 return make_alloc_exact((unsigned long)page_address(p), order, size);
4652 * free_pages_exact - release memory allocated via alloc_pages_exact()
4653 * @virt: the value returned by alloc_pages_exact.
4654 * @size: size of allocation, same value as passed to alloc_pages_exact().
4656 * Release the memory allocated by a previous call to alloc_pages_exact.
4658 void free_pages_exact(void *virt, size_t size)
4660 unsigned long addr = (unsigned long)virt;
4661 unsigned long end = addr + PAGE_ALIGN(size);
4663 while (addr < end) {
4668 EXPORT_SYMBOL(free_pages_exact);
4671 * nr_free_zone_pages - count number of pages beyond high watermark
4672 * @offset: The zone index of the highest zone
4674 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4675 * high watermark within all zones at or below a given zone index. For each
4676 * zone, the number of pages is calculated as:
4678 * nr_free_zone_pages = managed_pages - high_pages
4680 static unsigned long nr_free_zone_pages(int offset)
4685 /* Just pick one node, since fallback list is circular */
4686 unsigned long sum = 0;
4688 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4690 for_each_zone_zonelist(zone, z, zonelist, offset) {
4691 unsigned long size = zone->managed_pages;
4692 unsigned long high = high_wmark_pages(zone);
4701 * nr_free_buffer_pages - count number of pages beyond high watermark
4703 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4704 * watermark within ZONE_DMA and ZONE_NORMAL.
4706 unsigned long nr_free_buffer_pages(void)
4708 return nr_free_zone_pages(gfp_zone(GFP_USER));
4710 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4713 * nr_free_pagecache_pages - count number of pages beyond high watermark
4715 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4716 * high watermark within all zones.
4718 unsigned long nr_free_pagecache_pages(void)
4720 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4723 static inline void show_node(struct zone *zone)
4725 if (IS_ENABLED(CONFIG_NUMA))
4726 printk("Node %d ", zone_to_nid(zone));
4729 long si_mem_available(void)
4732 unsigned long pagecache;
4733 unsigned long wmark_low = 0;
4734 unsigned long pages[NR_LRU_LISTS];
4738 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4739 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
4742 wmark_low += zone->watermark[WMARK_LOW];
4745 * Estimate the amount of memory available for userspace allocations,
4746 * without causing swapping.
4748 available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;
4751 * Not all the page cache can be freed, otherwise the system will
4752 * start swapping. Assume at least half of the page cache, or the
4753 * low watermark worth of cache, needs to stay.
4755 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4756 pagecache -= min(pagecache / 2, wmark_low);
4757 available += pagecache;
4760 * Part of the reclaimable slab consists of items that are in use,
4761 * and cannot be freed. Cap this estimate at the low watermark.
4763 available += global_node_page_state(NR_SLAB_RECLAIMABLE) -
4764 min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2,
4768 * Part of the kernel memory, which can be released under memory
4771 available += global_node_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES) >>
4778 EXPORT_SYMBOL_GPL(si_mem_available);
4780 void si_meminfo(struct sysinfo *val)
4782 val->totalram = totalram_pages;
4783 val->sharedram = global_node_page_state(NR_SHMEM);
4784 val->freeram = global_zone_page_state(NR_FREE_PAGES);
4785 val->bufferram = nr_blockdev_pages();
4786 val->totalhigh = totalhigh_pages;
4787 val->freehigh = nr_free_highpages();
4788 val->mem_unit = PAGE_SIZE;
4791 EXPORT_SYMBOL(si_meminfo);
4794 void si_meminfo_node(struct sysinfo *val, int nid)
4796 int zone_type; /* needs to be signed */
4797 unsigned long managed_pages = 0;
4798 unsigned long managed_highpages = 0;
4799 unsigned long free_highpages = 0;
4800 pg_data_t *pgdat = NODE_DATA(nid);
4802 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4803 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4804 val->totalram = managed_pages;
4805 val->sharedram = node_page_state(pgdat, NR_SHMEM);
4806 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
4807 #ifdef CONFIG_HIGHMEM
4808 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4809 struct zone *zone = &pgdat->node_zones[zone_type];
4811 if (is_highmem(zone)) {
4812 managed_highpages += zone->managed_pages;
4813 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4816 val->totalhigh = managed_highpages;
4817 val->freehigh = free_highpages;
4819 val->totalhigh = managed_highpages;
4820 val->freehigh = free_highpages;
4822 val->mem_unit = PAGE_SIZE;
4827 * Determine whether the node should be displayed or not, depending on whether
4828 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4830 static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
4832 if (!(flags & SHOW_MEM_FILTER_NODES))
4836 * no node mask - aka implicit memory numa policy. Do not bother with
4837 * the synchronization - read_mems_allowed_begin - because we do not
4838 * have to be precise here.
4841 nodemask = &cpuset_current_mems_allowed;
4843 return !node_isset(nid, *nodemask);
4846 #define K(x) ((x) << (PAGE_SHIFT-10))
4848 static void show_migration_types(unsigned char type)
4850 static const char types[MIGRATE_TYPES] = {
4851 [MIGRATE_UNMOVABLE] = 'U',
4852 [MIGRATE_MOVABLE] = 'M',
4853 [MIGRATE_RECLAIMABLE] = 'E',
4854 [MIGRATE_HIGHATOMIC] = 'H',
4856 [MIGRATE_CMA] = 'C',
4858 #ifdef CONFIG_MEMORY_ISOLATION
4859 [MIGRATE_ISOLATE] = 'I',
4862 char tmp[MIGRATE_TYPES + 1];
4866 for (i = 0; i < MIGRATE_TYPES; i++) {
4867 if (type & (1 << i))
4872 printk(KERN_CONT "(%s) ", tmp);
4876 * Show free area list (used inside shift_scroll-lock stuff)
4877 * We also calculate the percentage fragmentation. We do this by counting the
4878 * memory on each free list with the exception of the first item on the list.
4881 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4884 void show_free_areas(unsigned int filter, nodemask_t *nodemask)
4886 unsigned long free_pcp = 0;
4891 for_each_populated_zone(zone) {
4892 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4895 for_each_online_cpu(cpu)
4896 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4899 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4900 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4901 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4902 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4903 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4904 " free:%lu free_pcp:%lu free_cma:%lu\n",
4905 global_node_page_state(NR_ACTIVE_ANON),
4906 global_node_page_state(NR_INACTIVE_ANON),
4907 global_node_page_state(NR_ISOLATED_ANON),
4908 global_node_page_state(NR_ACTIVE_FILE),
4909 global_node_page_state(NR_INACTIVE_FILE),
4910 global_node_page_state(NR_ISOLATED_FILE),
4911 global_node_page_state(NR_UNEVICTABLE),
4912 global_node_page_state(NR_FILE_DIRTY),
4913 global_node_page_state(NR_WRITEBACK),
4914 global_node_page_state(NR_UNSTABLE_NFS),
4915 global_node_page_state(NR_SLAB_RECLAIMABLE),
4916 global_node_page_state(NR_SLAB_UNRECLAIMABLE),
4917 global_node_page_state(NR_FILE_MAPPED),
4918 global_node_page_state(NR_SHMEM),
4919 global_zone_page_state(NR_PAGETABLE),
4920 global_zone_page_state(NR_BOUNCE),
4921 global_zone_page_state(NR_FREE_PAGES),
4923 global_zone_page_state(NR_FREE_CMA_PAGES));
4925 for_each_online_pgdat(pgdat) {
4926 if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
4930 " active_anon:%lukB"
4931 " inactive_anon:%lukB"
4932 " active_file:%lukB"
4933 " inactive_file:%lukB"
4934 " unevictable:%lukB"
4935 " isolated(anon):%lukB"
4936 " isolated(file):%lukB"
4941 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4943 " shmem_pmdmapped: %lukB"
4946 " writeback_tmp:%lukB"
4948 " all_unreclaimable? %s"
4951 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
4952 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
4953 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
4954 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
4955 K(node_page_state(pgdat, NR_UNEVICTABLE)),
4956 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
4957 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
4958 K(node_page_state(pgdat, NR_FILE_MAPPED)),
4959 K(node_page_state(pgdat, NR_FILE_DIRTY)),
4960 K(node_page_state(pgdat, NR_WRITEBACK)),
4961 K(node_page_state(pgdat, NR_SHMEM)),
4962 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4963 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
4964 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
4966 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
4968 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
4969 K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
4970 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
4974 for_each_populated_zone(zone) {
4977 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
4981 for_each_online_cpu(cpu)
4982 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4991 " active_anon:%lukB"
4992 " inactive_anon:%lukB"
4993 " active_file:%lukB"
4994 " inactive_file:%lukB"
4995 " unevictable:%lukB"
4996 " writepending:%lukB"
5000 " kernel_stack:%lukB"
5008 K(zone_page_state(zone, NR_FREE_PAGES)),
5009 K(min_wmark_pages(zone)),
5010 K(low_wmark_pages(zone)),
5011 K(high_wmark_pages(zone)),
5012 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
5013 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
5014 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
5015 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
5016 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
5017 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
5018 K(zone->present_pages),
5019 K(zone->managed_pages),
5020 K(zone_page_state(zone, NR_MLOCK)),
5021 zone_page_state(zone, NR_KERNEL_STACK_KB),
5022 K(zone_page_state(zone, NR_PAGETABLE)),
5023 K(zone_page_state(zone, NR_BOUNCE)),
5025 K(this_cpu_read(zone->pageset->pcp.count)),
5026 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
5027 printk("lowmem_reserve[]:");
5028 for (i = 0; i < MAX_NR_ZONES; i++)
5029 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
5030 printk(KERN_CONT "\n");
5033 for_each_populated_zone(zone) {
5035 unsigned long nr[MAX_ORDER], flags, total = 0;
5036 unsigned char types[MAX_ORDER];
5038 if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
5041 printk(KERN_CONT "%s: ", zone->name);
5043 spin_lock_irqsave(&zone->lock, flags);
5044 for (order = 0; order < MAX_ORDER; order++) {
5045 struct free_area *area = &zone->free_area[order];
5048 nr[order] = area->nr_free;
5049 total += nr[order] << order;
5052 for (type = 0; type < MIGRATE_TYPES; type++) {
5053 if (!list_empty(&area->free_list[type]))
5054 types[order] |= 1 << type;
5057 spin_unlock_irqrestore(&zone->lock, flags);
5058 for (order = 0; order < MAX_ORDER; order++) {
5059 printk(KERN_CONT "%lu*%lukB ",
5060 nr[order], K(1UL) << order);
5062 show_migration_types(types[order]);
5064 printk(KERN_CONT "= %lukB\n", K(total));
5067 hugetlb_show_meminfo();
5069 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
5071 show_swap_cache_info();
5074 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
5076 zoneref->zone = zone;
5077 zoneref->zone_idx = zone_idx(zone);
5081 * Builds allocation fallback zone lists.
5083 * Add all populated zones of a node to the zonelist.
5085 static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs)
5088 enum zone_type zone_type = MAX_NR_ZONES;
5093 zone = pgdat->node_zones + zone_type;
5094 if (populated_zone(zone)) {
5095 zoneref_set_zone(zone, &zonerefs[nr_zones++]);
5096 check_highest_zone(zone_type);
5098 } while (zone_type);
5105 static int __parse_numa_zonelist_order(char *s)
5108 * We used to support different zonlists modes but they turned
5109 * out to be just not useful. Let's keep the warning in place
5110 * if somebody still use the cmd line parameter so that we do
5111 * not fail it silently
5113 if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
5114 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s);
5120 static __init int setup_numa_zonelist_order(char *s)
5125 return __parse_numa_zonelist_order(s);
5127 early_param("numa_zonelist_order", setup_numa_zonelist_order);
5129 char numa_zonelist_order[] = "Node";
5132 * sysctl handler for numa_zonelist_order
5134 int numa_zonelist_order_handler(struct ctl_table *table, int write,
5135 void __user *buffer, size_t *length,
5142 return proc_dostring(table, write, buffer, length, ppos);
5143 str = memdup_user_nul(buffer, 16);
5145 return PTR_ERR(str);
5147 ret = __parse_numa_zonelist_order(str);
5153 #define MAX_NODE_LOAD (nr_online_nodes)
5154 static int node_load[MAX_NUMNODES];
5157 * find_next_best_node - find the next node that should appear in a given node's fallback list
5158 * @node: node whose fallback list we're appending
5159 * @used_node_mask: nodemask_t of already used nodes
5161 * We use a number of factors to determine which is the next node that should
5162 * appear on a given node's fallback list. The node should not have appeared
5163 * already in @node's fallback list, and it should be the next closest node
5164 * according to the distance array (which contains arbitrary distance values
5165 * from each node to each node in the system), and should also prefer nodes
5166 * with no CPUs, since presumably they'll have very little allocation pressure
5167 * on them otherwise.
5168 * It returns -1 if no node is found.
5170 static int find_next_best_node(int node, nodemask_t *used_node_mask)
5173 int min_val = INT_MAX;
5174 int best_node = NUMA_NO_NODE;
5175 const struct cpumask *tmp = cpumask_of_node(0);
5177 /* Use the local node if we haven't already */
5178 if (!node_isset(node, *used_node_mask)) {
5179 node_set(node, *used_node_mask);
5183 for_each_node_state(n, N_MEMORY) {
5185 /* Don't want a node to appear more than once */
5186 if (node_isset(n, *used_node_mask))
5189 /* Use the distance array to find the distance */
5190 val = node_distance(node, n);
5192 /* Penalize nodes under us ("prefer the next node") */
5195 /* Give preference to headless and unused nodes */
5196 tmp = cpumask_of_node(n);
5197 if (!cpumask_empty(tmp))
5198 val += PENALTY_FOR_NODE_WITH_CPUS;
5200 /* Slight preference for less loaded node */
5201 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
5202 val += node_load[n];
5204 if (val < min_val) {
5211 node_set(best_node, *used_node_mask);
5218 * Build zonelists ordered by node and zones within node.
5219 * This results in maximum locality--normal zone overflows into local
5220 * DMA zone, if any--but risks exhausting DMA zone.
5222 static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order,
5225 struct zoneref *zonerefs;
5228 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5230 for (i = 0; i < nr_nodes; i++) {
5233 pg_data_t *node = NODE_DATA(node_order[i]);
5235 nr_zones = build_zonerefs_node(node, zonerefs);
5236 zonerefs += nr_zones;
5238 zonerefs->zone = NULL;
5239 zonerefs->zone_idx = 0;
5243 * Build gfp_thisnode zonelists
5245 static void build_thisnode_zonelists(pg_data_t *pgdat)
5247 struct zoneref *zonerefs;
5250 zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs;
5251 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5252 zonerefs += nr_zones;
5253 zonerefs->zone = NULL;
5254 zonerefs->zone_idx = 0;
5258 * Build zonelists ordered by zone and nodes within zones.
5259 * This results in conserving DMA zone[s] until all Normal memory is
5260 * exhausted, but results in overflowing to remote node while memory
5261 * may still exist in local DMA zone.
5264 static void build_zonelists(pg_data_t *pgdat)
5266 static int node_order[MAX_NUMNODES];
5267 int node, load, nr_nodes = 0;
5268 nodemask_t used_mask;
5269 int local_node, prev_node;
5271 /* NUMA-aware ordering of nodes */
5272 local_node = pgdat->node_id;
5273 load = nr_online_nodes;
5274 prev_node = local_node;
5275 nodes_clear(used_mask);
5277 memset(node_order, 0, sizeof(node_order));
5278 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
5280 * We don't want to pressure a particular node.
5281 * So adding penalty to the first node in same
5282 * distance group to make it round-robin.
5284 if (node_distance(local_node, node) !=
5285 node_distance(local_node, prev_node))
5286 node_load[node] = load;
5288 node_order[nr_nodes++] = node;
5293 build_zonelists_in_node_order(pgdat, node_order, nr_nodes);
5294 build_thisnode_zonelists(pgdat);
5297 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5299 * Return node id of node used for "local" allocations.
5300 * I.e., first node id of first zone in arg node's generic zonelist.
5301 * Used for initializing percpu 'numa_mem', which is used primarily
5302 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5304 int local_memory_node(int node)
5308 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
5309 gfp_zone(GFP_KERNEL),
5311 return zone_to_nid(z->zone);
5315 static void setup_min_unmapped_ratio(void);
5316 static void setup_min_slab_ratio(void);
5317 #else /* CONFIG_NUMA */
5319 static void build_zonelists(pg_data_t *pgdat)
5321 int node, local_node;
5322 struct zoneref *zonerefs;
5325 local_node = pgdat->node_id;
5327 zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs;
5328 nr_zones = build_zonerefs_node(pgdat, zonerefs);
5329 zonerefs += nr_zones;
5332 * Now we build the zonelist so that it contains the zones
5333 * of all the other nodes.
5334 * We don't want to pressure a particular node, so when
5335 * building the zones for node N, we make sure that the
5336 * zones coming right after the local ones are those from
5337 * node N+1 (modulo N)
5339 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
5340 if (!node_online(node))
5342 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5343 zonerefs += nr_zones;
5345 for (node = 0; node < local_node; node++) {
5346 if (!node_online(node))
5348 nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs);
5349 zonerefs += nr_zones;
5352 zonerefs->zone = NULL;
5353 zonerefs->zone_idx = 0;
5356 #endif /* CONFIG_NUMA */
5359 * Boot pageset table. One per cpu which is going to be used for all
5360 * zones and all nodes. The parameters will be set in such a way
5361 * that an item put on a list will immediately be handed over to
5362 * the buddy list. This is safe since pageset manipulation is done
5363 * with interrupts disabled.
5365 * The boot_pagesets must be kept even after bootup is complete for
5366 * unused processors and/or zones. They do play a role for bootstrapping
5367 * hotplugged processors.
5369 * zoneinfo_show() and maybe other functions do
5370 * not check if the processor is online before following the pageset pointer.
5371 * Other parts of the kernel may not check if the zone is available.
5373 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
5374 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
5375 static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
5377 static void __build_all_zonelists(void *data)
5380 int __maybe_unused cpu;
5381 pg_data_t *self = data;
5382 static DEFINE_SPINLOCK(lock);
5387 memset(node_load, 0, sizeof(node_load));
5391 * This node is hotadded and no memory is yet present. So just
5392 * building zonelists is fine - no need to touch other nodes.
5394 if (self && !node_online(self->node_id)) {
5395 build_zonelists(self);
5397 for_each_online_node(nid) {
5398 pg_data_t *pgdat = NODE_DATA(nid);
5400 build_zonelists(pgdat);
5403 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5405 * We now know the "local memory node" for each node--
5406 * i.e., the node of the first zone in the generic zonelist.
5407 * Set up numa_mem percpu variable for on-line cpus. During
5408 * boot, only the boot cpu should be on-line; we'll init the
5409 * secondary cpus' numa_mem as they come on-line. During
5410 * node/memory hotplug, we'll fixup all on-line cpus.
5412 for_each_online_cpu(cpu)
5413 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
5420 static noinline void __init
5421 build_all_zonelists_init(void)
5425 __build_all_zonelists(NULL);
5428 * Initialize the boot_pagesets that are going to be used
5429 * for bootstrapping processors. The real pagesets for
5430 * each zone will be allocated later when the per cpu
5431 * allocator is available.
5433 * boot_pagesets are used also for bootstrapping offline
5434 * cpus if the system is already booted because the pagesets
5435 * are needed to initialize allocators on a specific cpu too.
5436 * F.e. the percpu allocator needs the page allocator which
5437 * needs the percpu allocator in order to allocate its pagesets
5438 * (a chicken-egg dilemma).
5440 for_each_possible_cpu(cpu)
5441 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
5443 mminit_verify_zonelist();
5444 cpuset_init_current_mems_allowed();
5448 * unless system_state == SYSTEM_BOOTING.
5450 * __ref due to call of __init annotated helper build_all_zonelists_init
5451 * [protected by SYSTEM_BOOTING].
5453 void __ref build_all_zonelists(pg_data_t *pgdat)
5455 if (system_state == SYSTEM_BOOTING) {
5456 build_all_zonelists_init();
5458 __build_all_zonelists(pgdat);
5459 /* cpuset refresh routine should be here */
5461 vm_total_pages = nr_free_pagecache_pages();
5463 * Disable grouping by mobility if the number of pages in the
5464 * system is too low to allow the mechanism to work. It would be
5465 * more accurate, but expensive to check per-zone. This check is
5466 * made on memory-hotadd so a system can start with mobility
5467 * disabled and enable it later
5469 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5470 page_group_by_mobility_disabled = 1;
5472 page_group_by_mobility_disabled = 0;
5474 pr_info("Built %i zonelists, mobility grouping %s. Total pages: %ld\n",
5476 page_group_by_mobility_disabled ? "off" : "on",
5479 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5484 * Initially all pages are reserved - free ones are freed
5485 * up by free_all_bootmem() once the early boot process is
5486 * done. Non-atomic initialization, single-pass.
5488 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5489 unsigned long start_pfn, enum meminit_context context,
5490 struct vmem_altmap *altmap)
5492 unsigned long end_pfn = start_pfn + size;
5493 pg_data_t *pgdat = NODE_DATA(nid);
5495 unsigned long nr_initialised = 0;
5497 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5498 struct memblock_region *r = NULL, *tmp;
5501 if (highest_memmap_pfn < end_pfn - 1)
5502 highest_memmap_pfn = end_pfn - 1;
5505 * Honor reservation requested by the driver for this ZONE_DEVICE
5508 if (altmap && start_pfn == altmap->base_pfn)
5509 start_pfn += altmap->reserve;
5511 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5513 * There can be holes in boot-time mem_map[]s handed to this
5514 * function. They do not exist on hotplugged memory.
5516 if (context != MEMINIT_EARLY)
5519 if (!early_pfn_valid(pfn))
5521 if (!early_pfn_in_nid(pfn, nid))
5523 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5526 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5528 * Check given memblock attribute by firmware which can affect
5529 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5530 * mirrored, it's an overlapped memmap init. skip it.
5532 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5533 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5534 for_each_memblock(memory, tmp)
5535 if (pfn < memblock_region_memory_end_pfn(tmp))
5539 if (pfn >= memblock_region_memory_base_pfn(r) &&
5540 memblock_is_mirror(r)) {
5541 /* already initialized as NORMAL */
5542 pfn = memblock_region_memory_end_pfn(r);
5549 page = pfn_to_page(pfn);
5550 __init_single_page(page, pfn, zone, nid);
5551 if (context == MEMINIT_HOTPLUG)
5552 SetPageReserved(page);
5555 * Mark the block movable so that blocks are reserved for
5556 * movable at startup. This will force kernel allocations
5557 * to reserve their blocks rather than leaking throughout
5558 * the address space during boot when many long-lived
5559 * kernel allocations are made.
5561 * bitmap is created for zone's valid pfn range. but memmap
5562 * can be created for invalid pages (for alignment)
5563 * check here not to call set_pageblock_migratetype() against
5566 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
5567 * because this is done early in sparse_add_one_section
5569 if (!(pfn & (pageblock_nr_pages - 1))) {
5570 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5576 static void __meminit zone_init_free_lists(struct zone *zone)
5578 unsigned int order, t;
5579 for_each_migratetype_order(order, t) {
5580 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5581 zone->free_area[order].nr_free = 0;
5585 #ifndef __HAVE_ARCH_MEMMAP_INIT
5586 #define memmap_init(size, nid, zone, start_pfn) \
5587 memmap_init_zone((size), (nid), (zone), (start_pfn), \
5588 MEMINIT_EARLY, NULL)
5591 static int zone_batchsize(struct zone *zone)
5597 * The per-cpu-pages pools are set to around 1000th of the
5600 batch = zone->managed_pages / 1024;
5601 /* But no more than a meg. */
5602 if (batch * PAGE_SIZE > 1024 * 1024)
5603 batch = (1024 * 1024) / PAGE_SIZE;
5604 batch /= 4; /* We effectively *= 4 below */
5609 * Clamp the batch to a 2^n - 1 value. Having a power
5610 * of 2 value was found to be more likely to have
5611 * suboptimal cache aliasing properties in some cases.
5613 * For example if 2 tasks are alternately allocating
5614 * batches of pages, one task can end up with a lot
5615 * of pages of one half of the possible page colors
5616 * and the other with pages of the other colors.
5618 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5623 /* The deferral and batching of frees should be suppressed under NOMMU
5626 * The problem is that NOMMU needs to be able to allocate large chunks
5627 * of contiguous memory as there's no hardware page translation to
5628 * assemble apparent contiguous memory from discontiguous pages.
5630 * Queueing large contiguous runs of pages for batching, however,
5631 * causes the pages to actually be freed in smaller chunks. As there
5632 * can be a significant delay between the individual batches being
5633 * recycled, this leads to the once large chunks of space being
5634 * fragmented and becoming unavailable for high-order allocations.
5641 * pcp->high and pcp->batch values are related and dependent on one another:
5642 * ->batch must never be higher then ->high.
5643 * The following function updates them in a safe manner without read side
5646 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5647 * those fields changing asynchronously (acording the the above rule).
5649 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5650 * outside of boot time (or some other assurance that no concurrent updaters
5653 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5654 unsigned long batch)
5656 /* start with a fail safe value for batch */
5660 /* Update high, then batch, in order */
5667 /* a companion to pageset_set_high() */
5668 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5670 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5673 static void pageset_init(struct per_cpu_pageset *p)
5675 struct per_cpu_pages *pcp;
5678 memset(p, 0, sizeof(*p));
5682 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5683 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5686 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5689 pageset_set_batch(p, batch);
5693 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5694 * to the value high for the pageset p.
5696 static void pageset_set_high(struct per_cpu_pageset *p,
5699 unsigned long batch = max(1UL, high / 4);
5700 if ((high / 4) > (PAGE_SHIFT * 8))
5701 batch = PAGE_SHIFT * 8;
5703 pageset_update(&p->pcp, high, batch);
5706 static void pageset_set_high_and_batch(struct zone *zone,
5707 struct per_cpu_pageset *pcp)
5709 if (percpu_pagelist_fraction)
5710 pageset_set_high(pcp,
5711 (zone->managed_pages /
5712 percpu_pagelist_fraction));
5714 pageset_set_batch(pcp, zone_batchsize(zone));
5717 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5719 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5722 pageset_set_high_and_batch(zone, pcp);
5725 void __meminit setup_zone_pageset(struct zone *zone)
5728 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5729 for_each_possible_cpu(cpu)
5730 zone_pageset_init(zone, cpu);
5734 * Allocate per cpu pagesets and initialize them.
5735 * Before this call only boot pagesets were available.
5737 void __init setup_per_cpu_pageset(void)
5739 struct pglist_data *pgdat;
5742 for_each_populated_zone(zone)
5743 setup_zone_pageset(zone);
5745 for_each_online_pgdat(pgdat)
5746 pgdat->per_cpu_nodestats =
5747 alloc_percpu(struct per_cpu_nodestat);
5750 static __meminit void zone_pcp_init(struct zone *zone)
5753 * per cpu subsystem is not up at this point. The following code
5754 * relies on the ability of the linker to provide the
5755 * offset of a (static) per cpu variable into the per cpu area.
5757 zone->pageset = &boot_pageset;
5759 if (populated_zone(zone))
5760 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5761 zone->name, zone->present_pages,
5762 zone_batchsize(zone));
5765 void __meminit init_currently_empty_zone(struct zone *zone,
5766 unsigned long zone_start_pfn,
5769 struct pglist_data *pgdat = zone->zone_pgdat;
5770 int zone_idx = zone_idx(zone) + 1;
5772 if (zone_idx > pgdat->nr_zones)
5773 pgdat->nr_zones = zone_idx;
5775 zone->zone_start_pfn = zone_start_pfn;
5777 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5778 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5780 (unsigned long)zone_idx(zone),
5781 zone_start_pfn, (zone_start_pfn + size));
5783 zone_init_free_lists(zone);
5784 zone->initialized = 1;
5787 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5788 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5791 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5793 int __meminit __early_pfn_to_nid(unsigned long pfn,
5794 struct mminit_pfnnid_cache *state)
5796 unsigned long start_pfn, end_pfn;
5799 if (state->last_start <= pfn && pfn < state->last_end)
5800 return state->last_nid;
5802 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5804 state->last_start = start_pfn;
5805 state->last_end = end_pfn;
5806 state->last_nid = nid;
5811 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5814 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5815 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5816 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5818 * If an architecture guarantees that all ranges registered contain no holes
5819 * and may be freed, this this function may be used instead of calling
5820 * memblock_free_early_nid() manually.
5822 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5824 unsigned long start_pfn, end_pfn;
5827 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5828 start_pfn = min(start_pfn, max_low_pfn);
5829 end_pfn = min(end_pfn, max_low_pfn);
5831 if (start_pfn < end_pfn)
5832 memblock_free_early_nid(PFN_PHYS(start_pfn),
5833 (end_pfn - start_pfn) << PAGE_SHIFT,
5839 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5840 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5842 * If an architecture guarantees that all ranges registered contain no holes and may
5843 * be freed, this function may be used instead of calling memory_present() manually.
5845 void __init sparse_memory_present_with_active_regions(int nid)
5847 unsigned long start_pfn, end_pfn;
5850 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5851 memory_present(this_nid, start_pfn, end_pfn);
5855 * get_pfn_range_for_nid - Return the start and end page frames for a node
5856 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5857 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5858 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5860 * It returns the start and end page frame of a node based on information
5861 * provided by memblock_set_node(). If called for a node
5862 * with no available memory, a warning is printed and the start and end
5865 void __meminit get_pfn_range_for_nid(unsigned int nid,
5866 unsigned long *start_pfn, unsigned long *end_pfn)
5868 unsigned long this_start_pfn, this_end_pfn;
5874 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5875 *start_pfn = min(*start_pfn, this_start_pfn);
5876 *end_pfn = max(*end_pfn, this_end_pfn);
5879 if (*start_pfn == -1UL)
5884 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5885 * assumption is made that zones within a node are ordered in monotonic
5886 * increasing memory addresses so that the "highest" populated zone is used
5888 static void __init find_usable_zone_for_movable(void)
5891 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5892 if (zone_index == ZONE_MOVABLE)
5895 if (arch_zone_highest_possible_pfn[zone_index] >
5896 arch_zone_lowest_possible_pfn[zone_index])
5900 VM_BUG_ON(zone_index == -1);
5901 movable_zone = zone_index;
5905 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5906 * because it is sized independent of architecture. Unlike the other zones,
5907 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5908 * in each node depending on the size of each node and how evenly kernelcore
5909 * is distributed. This helper function adjusts the zone ranges
5910 * provided by the architecture for a given node by using the end of the
5911 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5912 * zones within a node are in order of monotonic increases memory addresses
5914 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5915 unsigned long zone_type,
5916 unsigned long node_start_pfn,
5917 unsigned long node_end_pfn,
5918 unsigned long *zone_start_pfn,
5919 unsigned long *zone_end_pfn)
5921 /* Only adjust if ZONE_MOVABLE is on this node */
5922 if (zone_movable_pfn[nid]) {
5923 /* Size ZONE_MOVABLE */
5924 if (zone_type == ZONE_MOVABLE) {
5925 *zone_start_pfn = zone_movable_pfn[nid];
5926 *zone_end_pfn = min(node_end_pfn,
5927 arch_zone_highest_possible_pfn[movable_zone]);
5929 /* Adjust for ZONE_MOVABLE starting within this range */
5930 } else if (!mirrored_kernelcore &&
5931 *zone_start_pfn < zone_movable_pfn[nid] &&
5932 *zone_end_pfn > zone_movable_pfn[nid]) {
5933 *zone_end_pfn = zone_movable_pfn[nid];
5935 /* Check if this whole range is within ZONE_MOVABLE */
5936 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5937 *zone_start_pfn = *zone_end_pfn;
5942 * Return the number of pages a zone spans in a node, including holes
5943 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5945 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5946 unsigned long zone_type,
5947 unsigned long node_start_pfn,
5948 unsigned long node_end_pfn,
5949 unsigned long *zone_start_pfn,
5950 unsigned long *zone_end_pfn,
5951 unsigned long *ignored)
5953 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5954 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5955 /* When hotadd a new node from cpu_up(), the node should be empty */
5956 if (!node_start_pfn && !node_end_pfn)
5959 /* Get the start and end of the zone */
5960 *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5961 *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5962 adjust_zone_range_for_zone_movable(nid, zone_type,
5963 node_start_pfn, node_end_pfn,
5964 zone_start_pfn, zone_end_pfn);
5966 /* Check that this node has pages within the zone's required range */
5967 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5970 /* Move the zone boundaries inside the node if necessary */
5971 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5972 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5974 /* Return the spanned pages */
5975 return *zone_end_pfn - *zone_start_pfn;
5979 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5980 * then all holes in the requested range will be accounted for.
5982 unsigned long __meminit __absent_pages_in_range(int nid,
5983 unsigned long range_start_pfn,
5984 unsigned long range_end_pfn)
5986 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5987 unsigned long start_pfn, end_pfn;
5990 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5991 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5992 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5993 nr_absent -= end_pfn - start_pfn;
5999 * absent_pages_in_range - Return number of page frames in holes within a range
6000 * @start_pfn: The start PFN to start searching for holes
6001 * @end_pfn: The end PFN to stop searching for holes
6003 * It returns the number of pages frames in memory holes within a range.
6005 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
6006 unsigned long end_pfn)
6008 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
6011 /* Return the number of page frames in holes in a zone on a node */
6012 static unsigned long __meminit zone_absent_pages_in_node(int nid,
6013 unsigned long zone_type,
6014 unsigned long node_start_pfn,
6015 unsigned long node_end_pfn,
6016 unsigned long *ignored)
6018 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
6019 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
6020 unsigned long zone_start_pfn, zone_end_pfn;
6021 unsigned long nr_absent;
6023 /* When hotadd a new node from cpu_up(), the node should be empty */
6024 if (!node_start_pfn && !node_end_pfn)
6027 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
6028 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
6030 adjust_zone_range_for_zone_movable(nid, zone_type,
6031 node_start_pfn, node_end_pfn,
6032 &zone_start_pfn, &zone_end_pfn);
6033 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
6036 * ZONE_MOVABLE handling.
6037 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6040 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
6041 unsigned long start_pfn, end_pfn;
6042 struct memblock_region *r;
6044 for_each_memblock(memory, r) {
6045 start_pfn = clamp(memblock_region_memory_base_pfn(r),
6046 zone_start_pfn, zone_end_pfn);
6047 end_pfn = clamp(memblock_region_memory_end_pfn(r),
6048 zone_start_pfn, zone_end_pfn);
6050 if (zone_type == ZONE_MOVABLE &&
6051 memblock_is_mirror(r))
6052 nr_absent += end_pfn - start_pfn;
6054 if (zone_type == ZONE_NORMAL &&
6055 !memblock_is_mirror(r))
6056 nr_absent += end_pfn - start_pfn;
6063 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6064 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
6065 unsigned long zone_type,
6066 unsigned long node_start_pfn,
6067 unsigned long node_end_pfn,
6068 unsigned long *zone_start_pfn,
6069 unsigned long *zone_end_pfn,
6070 unsigned long *zones_size)
6074 *zone_start_pfn = node_start_pfn;
6075 for (zone = 0; zone < zone_type; zone++)
6076 *zone_start_pfn += zones_size[zone];
6078 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
6080 return zones_size[zone_type];
6083 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
6084 unsigned long zone_type,
6085 unsigned long node_start_pfn,
6086 unsigned long node_end_pfn,
6087 unsigned long *zholes_size)
6092 return zholes_size[zone_type];
6095 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6097 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
6098 unsigned long node_start_pfn,
6099 unsigned long node_end_pfn,
6100 unsigned long *zones_size,
6101 unsigned long *zholes_size)
6103 unsigned long realtotalpages = 0, totalpages = 0;
6106 for (i = 0; i < MAX_NR_ZONES; i++) {
6107 struct zone *zone = pgdat->node_zones + i;
6108 unsigned long zone_start_pfn, zone_end_pfn;
6109 unsigned long size, real_size;
6111 size = zone_spanned_pages_in_node(pgdat->node_id, i,
6117 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
6118 node_start_pfn, node_end_pfn,
6121 zone->zone_start_pfn = zone_start_pfn;
6123 zone->zone_start_pfn = 0;
6124 zone->spanned_pages = size;
6125 zone->present_pages = real_size;
6128 realtotalpages += real_size;
6131 pgdat->node_spanned_pages = totalpages;
6132 pgdat->node_present_pages = realtotalpages;
6133 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
6137 #ifndef CONFIG_SPARSEMEM
6139 * Calculate the size of the zone->blockflags rounded to an unsigned long
6140 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6141 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6142 * round what is now in bits to nearest long in bits, then return it in
6145 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
6147 unsigned long usemapsize;
6149 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
6150 usemapsize = roundup(zonesize, pageblock_nr_pages);
6151 usemapsize = usemapsize >> pageblock_order;
6152 usemapsize *= NR_PAGEBLOCK_BITS;
6153 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
6155 return usemapsize / 8;
6158 static void __ref setup_usemap(struct pglist_data *pgdat,
6160 unsigned long zone_start_pfn,
6161 unsigned long zonesize)
6163 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
6164 zone->pageblock_flags = NULL;
6166 zone->pageblock_flags =
6167 memblock_virt_alloc_node_nopanic(usemapsize,
6171 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
6172 unsigned long zone_start_pfn, unsigned long zonesize) {}
6173 #endif /* CONFIG_SPARSEMEM */
6175 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6177 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6178 void __init set_pageblock_order(void)
6182 /* Check that pageblock_nr_pages has not already been setup */
6183 if (pageblock_order)
6186 if (HPAGE_SHIFT > PAGE_SHIFT)
6187 order = HUGETLB_PAGE_ORDER;
6189 order = MAX_ORDER - 1;
6192 * Assume the largest contiguous order of interest is a huge page.
6193 * This value may be variable depending on boot parameters on IA64 and
6196 pageblock_order = order;
6198 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6201 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6202 * is unused as pageblock_order is set at compile-time. See
6203 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6206 void __init set_pageblock_order(void)
6210 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6212 static unsigned long __init calc_memmap_size(unsigned long spanned_pages,
6213 unsigned long present_pages)
6215 unsigned long pages = spanned_pages;
6218 * Provide a more accurate estimation if there are holes within
6219 * the zone and SPARSEMEM is in use. If there are holes within the
6220 * zone, each populated memory region may cost us one or two extra
6221 * memmap pages due to alignment because memmap pages for each
6222 * populated regions may not be naturally aligned on page boundary.
6223 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6225 if (spanned_pages > present_pages + (present_pages >> 4) &&
6226 IS_ENABLED(CONFIG_SPARSEMEM))
6227 pages = present_pages;
6229 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
6232 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6233 static void pgdat_init_split_queue(struct pglist_data *pgdat)
6235 spin_lock_init(&pgdat->split_queue_lock);
6236 INIT_LIST_HEAD(&pgdat->split_queue);
6237 pgdat->split_queue_len = 0;
6240 static void pgdat_init_split_queue(struct pglist_data *pgdat) {}
6243 #ifdef CONFIG_COMPACTION
6244 static void pgdat_init_kcompactd(struct pglist_data *pgdat)
6246 init_waitqueue_head(&pgdat->kcompactd_wait);
6249 static void pgdat_init_kcompactd(struct pglist_data *pgdat) {}
6252 static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
6254 pgdat_resize_init(pgdat);
6256 pgdat_init_split_queue(pgdat);
6257 pgdat_init_kcompactd(pgdat);
6259 init_waitqueue_head(&pgdat->kswapd_wait);
6260 init_waitqueue_head(&pgdat->pfmemalloc_wait);
6262 pgdat_page_ext_init(pgdat);
6263 spin_lock_init(&pgdat->lru_lock);
6264 lruvec_init(node_lruvec(pgdat));
6267 static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,
6268 unsigned long remaining_pages)
6270 zone->managed_pages = remaining_pages;
6271 zone_set_nid(zone, nid);
6272 zone->name = zone_names[idx];
6273 zone->zone_pgdat = NODE_DATA(nid);
6274 spin_lock_init(&zone->lock);
6275 zone_seqlock_init(zone);
6276 zone_pcp_init(zone);
6280 * Set up the zone data structures
6281 * - init pgdat internals
6282 * - init all zones belonging to this node
6284 * NOTE: this function is only called during memory hotplug
6286 #ifdef CONFIG_MEMORY_HOTPLUG
6287 void __ref free_area_init_core_hotplug(int nid)
6290 pg_data_t *pgdat = NODE_DATA(nid);
6292 pgdat_init_internals(pgdat);
6293 for (z = 0; z < MAX_NR_ZONES; z++)
6294 zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
6299 * Set up the zone data structures:
6300 * - mark all pages reserved
6301 * - mark all memory queues empty
6302 * - clear the memory bitmaps
6304 * NOTE: pgdat should get zeroed by caller.
6305 * NOTE: this function is only called during early init.
6307 static void __init free_area_init_core(struct pglist_data *pgdat)
6310 int nid = pgdat->node_id;
6312 pgdat_init_internals(pgdat);
6313 pgdat->per_cpu_nodestats = &boot_nodestats;
6315 for (j = 0; j < MAX_NR_ZONES; j++) {
6316 struct zone *zone = pgdat->node_zones + j;
6317 unsigned long size, freesize, memmap_pages;
6318 unsigned long zone_start_pfn = zone->zone_start_pfn;
6320 size = zone->spanned_pages;
6321 freesize = zone->present_pages;
6324 * Adjust freesize so that it accounts for how much memory
6325 * is used by this zone for memmap. This affects the watermark
6326 * and per-cpu initialisations
6328 memmap_pages = calc_memmap_size(size, freesize);
6329 if (!is_highmem_idx(j)) {
6330 if (freesize >= memmap_pages) {
6331 freesize -= memmap_pages;
6334 " %s zone: %lu pages used for memmap\n",
6335 zone_names[j], memmap_pages);
6337 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6338 zone_names[j], memmap_pages, freesize);
6341 /* Account for reserved pages */
6342 if (j == 0 && freesize > dma_reserve) {
6343 freesize -= dma_reserve;
6344 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
6345 zone_names[0], dma_reserve);
6348 if (!is_highmem_idx(j))
6349 nr_kernel_pages += freesize;
6350 /* Charge for highmem memmap if there are enough kernel pages */
6351 else if (nr_kernel_pages > memmap_pages * 2)
6352 nr_kernel_pages -= memmap_pages;
6353 nr_all_pages += freesize;
6356 * Set an approximate value for lowmem here, it will be adjusted
6357 * when the bootmem allocator frees pages into the buddy system.
6358 * And all highmem pages will be managed by the buddy system.
6360 zone_init_internals(zone, j, nid, freesize);
6365 set_pageblock_order();
6366 setup_usemap(pgdat, zone, zone_start_pfn, size);
6367 init_currently_empty_zone(zone, zone_start_pfn, size);
6368 memmap_init(size, nid, j, zone_start_pfn);
6372 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6373 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
6375 unsigned long __maybe_unused start = 0;
6376 unsigned long __maybe_unused offset = 0;
6378 /* Skip empty nodes */
6379 if (!pgdat->node_spanned_pages)
6382 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6383 offset = pgdat->node_start_pfn - start;
6384 /* ia64 gets its own node_mem_map, before this, without bootmem */
6385 if (!pgdat->node_mem_map) {
6386 unsigned long size, end;
6390 * The zone's endpoints aren't required to be MAX_ORDER
6391 * aligned but the node_mem_map endpoints must be in order
6392 * for the buddy allocator to function correctly.
6394 end = pgdat_end_pfn(pgdat);
6395 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6396 size = (end - start) * sizeof(struct page);
6397 map = memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
6398 pgdat->node_mem_map = map + offset;
6400 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6401 __func__, pgdat->node_id, (unsigned long)pgdat,
6402 (unsigned long)pgdat->node_mem_map);
6403 #ifndef CONFIG_NEED_MULTIPLE_NODES
6405 * With no DISCONTIG, the global mem_map is just set as node 0's
6407 if (pgdat == NODE_DATA(0)) {
6408 mem_map = NODE_DATA(0)->node_mem_map;
6409 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6410 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6412 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6417 static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
6418 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6420 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6421 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
6424 * We start only with one section of pages, more pages are added as
6425 * needed until the rest of deferred pages are initialized.
6427 pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
6428 pgdat->node_spanned_pages);
6429 pgdat->first_deferred_pfn = ULONG_MAX;
6432 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
6435 void __init free_area_init_node(int nid, unsigned long *zones_size,
6436 unsigned long node_start_pfn,
6437 unsigned long *zholes_size)
6439 pg_data_t *pgdat = NODE_DATA(nid);
6440 unsigned long start_pfn = 0;
6441 unsigned long end_pfn = 0;
6443 /* pg_data_t should be reset to zero when it's allocated */
6444 WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
6446 pgdat->node_id = nid;
6447 pgdat->node_start_pfn = node_start_pfn;
6448 pgdat->per_cpu_nodestats = NULL;
6449 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6450 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6451 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6452 (u64)start_pfn << PAGE_SHIFT,
6453 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6455 start_pfn = node_start_pfn;
6457 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6458 zones_size, zholes_size);
6460 alloc_node_mem_map(pgdat);
6461 pgdat_set_deferred_range(pgdat);
6463 free_area_init_core(pgdat);
6466 #if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP)
6469 * Zero all valid struct pages in range [spfn, epfn), return number of struct
6472 static u64 zero_pfn_range(unsigned long spfn, unsigned long epfn)
6477 for (pfn = spfn; pfn < epfn; pfn++) {
6478 if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
6479 pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
6480 + pageblock_nr_pages - 1;
6483 mm_zero_struct_page(pfn_to_page(pfn));
6491 * Only struct pages that are backed by physical memory are zeroed and
6492 * initialized by going through __init_single_page(). But, there are some
6493 * struct pages which are reserved in memblock allocator and their fields
6494 * may be accessed (for example page_to_pfn() on some configuration accesses
6495 * flags). We must explicitly zero those struct pages.
6497 * This function also addresses a similar issue where struct pages are left
6498 * uninitialized because the physical address range is not covered by
6499 * memblock.memory or memblock.reserved. That could happen when memblock
6500 * layout is manually configured via memmap=, or when the highest physical
6501 * address (max_pfn) does not end on a section boundary.
6503 void __init zero_resv_unavail(void)
6505 phys_addr_t start, end;
6507 phys_addr_t next = 0;
6510 * Loop through unavailable ranges not covered by memblock.memory.
6513 for_each_mem_range(i, &memblock.memory, NULL,
6514 NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) {
6516 pgcnt += zero_pfn_range(PFN_DOWN(next), PFN_UP(start));
6521 * Early sections always have a fully populated memmap for the whole
6522 * section - see pfn_valid(). If the last section has holes at the
6523 * end and that section is marked "online", the memmap will be
6524 * considered initialized. Make sure that memmap has a well defined
6527 pgcnt += zero_pfn_range(PFN_DOWN(next),
6528 round_up(max_pfn, PAGES_PER_SECTION));
6531 * Struct pages that do not have backing memory. This could be because
6532 * firmware is using some of this memory, or for some other reasons.
6535 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt);
6537 #endif /* CONFIG_HAVE_MEMBLOCK && !CONFIG_FLAT_NODE_MEM_MAP */
6539 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6541 #if MAX_NUMNODES > 1
6543 * Figure out the number of possible node ids.
6545 void __init setup_nr_node_ids(void)
6547 unsigned int highest;
6549 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
6550 nr_node_ids = highest + 1;
6555 * node_map_pfn_alignment - determine the maximum internode alignment
6557 * This function should be called after node map is populated and sorted.
6558 * It calculates the maximum power of two alignment which can distinguish
6561 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6562 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6563 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6564 * shifted, 1GiB is enough and this function will indicate so.
6566 * This is used to test whether pfn -> nid mapping of the chosen memory
6567 * model has fine enough granularity to avoid incorrect mapping for the
6568 * populated node map.
6570 * Returns the determined alignment in pfn's. 0 if there is no alignment
6571 * requirement (single node).
6573 unsigned long __init node_map_pfn_alignment(void)
6575 unsigned long accl_mask = 0, last_end = 0;
6576 unsigned long start, end, mask;
6580 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
6581 if (!start || last_nid < 0 || last_nid == nid) {
6588 * Start with a mask granular enough to pin-point to the
6589 * start pfn and tick off bits one-by-one until it becomes
6590 * too coarse to separate the current node from the last.
6592 mask = ~((1 << __ffs(start)) - 1);
6593 while (mask && last_end <= (start & (mask << 1)))
6596 /* accumulate all internode masks */
6600 /* convert mask to number of pages */
6601 return ~accl_mask + 1;
6604 /* Find the lowest pfn for a node */
6605 static unsigned long __init find_min_pfn_for_node(int nid)
6607 unsigned long min_pfn = ULONG_MAX;
6608 unsigned long start_pfn;
6611 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
6612 min_pfn = min(min_pfn, start_pfn);
6614 if (min_pfn == ULONG_MAX) {
6615 pr_warn("Could not find start_pfn for node %d\n", nid);
6623 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6625 * It returns the minimum PFN based on information provided via
6626 * memblock_set_node().
6628 unsigned long __init find_min_pfn_with_active_regions(void)
6630 return find_min_pfn_for_node(MAX_NUMNODES);
6634 * early_calculate_totalpages()
6635 * Sum pages in active regions for movable zone.
6636 * Populate N_MEMORY for calculating usable_nodes.
6638 static unsigned long __init early_calculate_totalpages(void)
6640 unsigned long totalpages = 0;
6641 unsigned long start_pfn, end_pfn;
6644 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6645 unsigned long pages = end_pfn - start_pfn;
6647 totalpages += pages;
6649 node_set_state(nid, N_MEMORY);
6655 * Find the PFN the Movable zone begins in each node. Kernel memory
6656 * is spread evenly between nodes as long as the nodes have enough
6657 * memory. When they don't, some nodes will have more kernelcore than
6660 static void __init find_zone_movable_pfns_for_nodes(void)
6663 unsigned long usable_startpfn;
6664 unsigned long kernelcore_node, kernelcore_remaining;
6665 /* save the state before borrow the nodemask */
6666 nodemask_t saved_node_state = node_states[N_MEMORY];
6667 unsigned long totalpages = early_calculate_totalpages();
6668 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6669 struct memblock_region *r;
6671 /* Need to find movable_zone earlier when movable_node is specified. */
6672 find_usable_zone_for_movable();
6675 * If movable_node is specified, ignore kernelcore and movablecore
6678 if (movable_node_is_enabled()) {
6679 for_each_memblock(memory, r) {
6680 if (!memblock_is_hotpluggable(r))
6685 usable_startpfn = PFN_DOWN(r->base);
6686 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6687 min(usable_startpfn, zone_movable_pfn[nid]) :
6695 * If kernelcore=mirror is specified, ignore movablecore option
6697 if (mirrored_kernelcore) {
6698 bool mem_below_4gb_not_mirrored = false;
6700 for_each_memblock(memory, r) {
6701 if (memblock_is_mirror(r))
6706 usable_startpfn = memblock_region_memory_base_pfn(r);
6708 if (usable_startpfn < 0x100000) {
6709 mem_below_4gb_not_mirrored = true;
6713 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6714 min(usable_startpfn, zone_movable_pfn[nid]) :
6718 if (mem_below_4gb_not_mirrored)
6719 pr_warn("This configuration results in unmirrored kernel memory.");
6725 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
6726 * amount of necessary memory.
6728 if (required_kernelcore_percent)
6729 required_kernelcore = (totalpages * 100 * required_kernelcore_percent) /
6731 if (required_movablecore_percent)
6732 required_movablecore = (totalpages * 100 * required_movablecore_percent) /
6736 * If movablecore= was specified, calculate what size of
6737 * kernelcore that corresponds so that memory usable for
6738 * any allocation type is evenly spread. If both kernelcore
6739 * and movablecore are specified, then the value of kernelcore
6740 * will be used for required_kernelcore if it's greater than
6741 * what movablecore would have allowed.
6743 if (required_movablecore) {
6744 unsigned long corepages;
6747 * Round-up so that ZONE_MOVABLE is at least as large as what
6748 * was requested by the user
6750 required_movablecore =
6751 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6752 required_movablecore = min(totalpages, required_movablecore);
6753 corepages = totalpages - required_movablecore;
6755 required_kernelcore = max(required_kernelcore, corepages);
6759 * If kernelcore was not specified or kernelcore size is larger
6760 * than totalpages, there is no ZONE_MOVABLE.
6762 if (!required_kernelcore || required_kernelcore >= totalpages)
6765 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6766 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6769 /* Spread kernelcore memory as evenly as possible throughout nodes */
6770 kernelcore_node = required_kernelcore / usable_nodes;
6771 for_each_node_state(nid, N_MEMORY) {
6772 unsigned long start_pfn, end_pfn;
6775 * Recalculate kernelcore_node if the division per node
6776 * now exceeds what is necessary to satisfy the requested
6777 * amount of memory for the kernel
6779 if (required_kernelcore < kernelcore_node)
6780 kernelcore_node = required_kernelcore / usable_nodes;
6783 * As the map is walked, we track how much memory is usable
6784 * by the kernel using kernelcore_remaining. When it is
6785 * 0, the rest of the node is usable by ZONE_MOVABLE
6787 kernelcore_remaining = kernelcore_node;
6789 /* Go through each range of PFNs within this node */
6790 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6791 unsigned long size_pages;
6793 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6794 if (start_pfn >= end_pfn)
6797 /* Account for what is only usable for kernelcore */
6798 if (start_pfn < usable_startpfn) {
6799 unsigned long kernel_pages;
6800 kernel_pages = min(end_pfn, usable_startpfn)
6803 kernelcore_remaining -= min(kernel_pages,
6804 kernelcore_remaining);
6805 required_kernelcore -= min(kernel_pages,
6806 required_kernelcore);
6808 /* Continue if range is now fully accounted */
6809 if (end_pfn <= usable_startpfn) {
6812 * Push zone_movable_pfn to the end so
6813 * that if we have to rebalance
6814 * kernelcore across nodes, we will
6815 * not double account here
6817 zone_movable_pfn[nid] = end_pfn;
6820 start_pfn = usable_startpfn;
6824 * The usable PFN range for ZONE_MOVABLE is from
6825 * start_pfn->end_pfn. Calculate size_pages as the
6826 * number of pages used as kernelcore
6828 size_pages = end_pfn - start_pfn;
6829 if (size_pages > kernelcore_remaining)
6830 size_pages = kernelcore_remaining;
6831 zone_movable_pfn[nid] = start_pfn + size_pages;
6834 * Some kernelcore has been met, update counts and
6835 * break if the kernelcore for this node has been
6838 required_kernelcore -= min(required_kernelcore,
6840 kernelcore_remaining -= size_pages;
6841 if (!kernelcore_remaining)
6847 * If there is still required_kernelcore, we do another pass with one
6848 * less node in the count. This will push zone_movable_pfn[nid] further
6849 * along on the nodes that still have memory until kernelcore is
6853 if (usable_nodes && required_kernelcore > usable_nodes)
6857 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6858 for (nid = 0; nid < MAX_NUMNODES; nid++) {
6859 unsigned long start_pfn, end_pfn;
6861 zone_movable_pfn[nid] =
6862 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6864 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6865 if (zone_movable_pfn[nid] >= end_pfn)
6866 zone_movable_pfn[nid] = 0;
6870 /* restore the node_state */
6871 node_states[N_MEMORY] = saved_node_state;
6874 /* Any regular or high memory on that node ? */
6875 static void check_for_memory(pg_data_t *pgdat, int nid)
6877 enum zone_type zone_type;
6879 if (N_MEMORY == N_NORMAL_MEMORY)
6882 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6883 struct zone *zone = &pgdat->node_zones[zone_type];
6884 if (populated_zone(zone)) {
6885 node_set_state(nid, N_HIGH_MEMORY);
6886 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6887 zone_type <= ZONE_NORMAL)
6888 node_set_state(nid, N_NORMAL_MEMORY);
6895 * free_area_init_nodes - Initialise all pg_data_t and zone data
6896 * @max_zone_pfn: an array of max PFNs for each zone
6898 * This will call free_area_init_node() for each active node in the system.
6899 * Using the page ranges provided by memblock_set_node(), the size of each
6900 * zone in each node and their holes is calculated. If the maximum PFN
6901 * between two adjacent zones match, it is assumed that the zone is empty.
6902 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6903 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6904 * starts where the previous one ended. For example, ZONE_DMA32 starts
6905 * at arch_max_dma_pfn.
6907 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6909 unsigned long start_pfn, end_pfn;
6912 /* Record where the zone boundaries are */
6913 memset(arch_zone_lowest_possible_pfn, 0,
6914 sizeof(arch_zone_lowest_possible_pfn));
6915 memset(arch_zone_highest_possible_pfn, 0,
6916 sizeof(arch_zone_highest_possible_pfn));
6918 start_pfn = find_min_pfn_with_active_regions();
6920 for (i = 0; i < MAX_NR_ZONES; i++) {
6921 if (i == ZONE_MOVABLE)
6924 end_pfn = max(max_zone_pfn[i], start_pfn);
6925 arch_zone_lowest_possible_pfn[i] = start_pfn;
6926 arch_zone_highest_possible_pfn[i] = end_pfn;
6928 start_pfn = end_pfn;
6931 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6932 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6933 find_zone_movable_pfns_for_nodes();
6935 /* Print out the zone ranges */
6936 pr_info("Zone ranges:\n");
6937 for (i = 0; i < MAX_NR_ZONES; i++) {
6938 if (i == ZONE_MOVABLE)
6940 pr_info(" %-8s ", zone_names[i]);
6941 if (arch_zone_lowest_possible_pfn[i] ==
6942 arch_zone_highest_possible_pfn[i])
6945 pr_cont("[mem %#018Lx-%#018Lx]\n",
6946 (u64)arch_zone_lowest_possible_pfn[i]
6948 ((u64)arch_zone_highest_possible_pfn[i]
6949 << PAGE_SHIFT) - 1);
6952 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6953 pr_info("Movable zone start for each node\n");
6954 for (i = 0; i < MAX_NUMNODES; i++) {
6955 if (zone_movable_pfn[i])
6956 pr_info(" Node %d: %#018Lx\n", i,
6957 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6960 /* Print out the early node map */
6961 pr_info("Early memory node ranges\n");
6962 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6963 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6964 (u64)start_pfn << PAGE_SHIFT,
6965 ((u64)end_pfn << PAGE_SHIFT) - 1);
6967 /* Initialise every node */
6968 mminit_verify_pageflags_layout();
6969 setup_nr_node_ids();
6970 zero_resv_unavail();
6971 for_each_online_node(nid) {
6972 pg_data_t *pgdat = NODE_DATA(nid);
6973 free_area_init_node(nid, NULL,
6974 find_min_pfn_for_node(nid), NULL);
6976 /* Any memory on that node */
6977 if (pgdat->node_present_pages)
6978 node_set_state(nid, N_MEMORY);
6979 check_for_memory(pgdat, nid);
6983 static int __init cmdline_parse_core(char *p, unsigned long *core,
6984 unsigned long *percent)
6986 unsigned long long coremem;
6992 /* Value may be a percentage of total memory, otherwise bytes */
6993 coremem = simple_strtoull(p, &endptr, 0);
6994 if (*endptr == '%') {
6995 /* Paranoid check for percent values greater than 100 */
6996 WARN_ON(coremem > 100);
7000 coremem = memparse(p, &p);
7001 /* Paranoid check that UL is enough for the coremem value */
7002 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
7004 *core = coremem >> PAGE_SHIFT;
7011 * kernelcore=size sets the amount of memory for use for allocations that
7012 * cannot be reclaimed or migrated.
7014 static int __init cmdline_parse_kernelcore(char *p)
7016 /* parse kernelcore=mirror */
7017 if (parse_option_str(p, "mirror")) {
7018 mirrored_kernelcore = true;
7022 return cmdline_parse_core(p, &required_kernelcore,
7023 &required_kernelcore_percent);
7027 * movablecore=size sets the amount of memory for use for allocations that
7028 * can be reclaimed or migrated.
7030 static int __init cmdline_parse_movablecore(char *p)
7032 return cmdline_parse_core(p, &required_movablecore,
7033 &required_movablecore_percent);
7036 early_param("kernelcore", cmdline_parse_kernelcore);
7037 early_param("movablecore", cmdline_parse_movablecore);
7039 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
7041 void adjust_managed_page_count(struct page *page, long count)
7043 spin_lock(&managed_page_count_lock);
7044 page_zone(page)->managed_pages += count;
7045 totalram_pages += count;
7046 #ifdef CONFIG_HIGHMEM
7047 if (PageHighMem(page))
7048 totalhigh_pages += count;
7050 spin_unlock(&managed_page_count_lock);
7052 EXPORT_SYMBOL(adjust_managed_page_count);
7054 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
7057 unsigned long pages = 0;
7059 start = (void *)PAGE_ALIGN((unsigned long)start);
7060 end = (void *)((unsigned long)end & PAGE_MASK);
7061 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
7062 struct page *page = virt_to_page(pos);
7063 void *direct_map_addr;
7066 * 'direct_map_addr' might be different from 'pos'
7067 * because some architectures' virt_to_page()
7068 * work with aliases. Getting the direct map
7069 * address ensures that we get a _writeable_
7070 * alias for the memset().
7072 direct_map_addr = page_address(page);
7073 if ((unsigned int)poison <= 0xFF)
7074 memset(direct_map_addr, poison, PAGE_SIZE);
7076 free_reserved_page(page);
7080 pr_info("Freeing %s memory: %ldK\n",
7081 s, pages << (PAGE_SHIFT - 10));
7085 EXPORT_SYMBOL(free_reserved_area);
7087 #ifdef CONFIG_HIGHMEM
7088 void free_highmem_page(struct page *page)
7090 __free_reserved_page(page);
7092 page_zone(page)->managed_pages++;
7098 void __init mem_init_print_info(const char *str)
7100 unsigned long physpages, codesize, datasize, rosize, bss_size;
7101 unsigned long init_code_size, init_data_size;
7103 physpages = get_num_physpages();
7104 codesize = _etext - _stext;
7105 datasize = _edata - _sdata;
7106 rosize = __end_rodata - __start_rodata;
7107 bss_size = __bss_stop - __bss_start;
7108 init_data_size = __init_end - __init_begin;
7109 init_code_size = _einittext - _sinittext;
7112 * Detect special cases and adjust section sizes accordingly:
7113 * 1) .init.* may be embedded into .data sections
7114 * 2) .init.text.* may be out of [__init_begin, __init_end],
7115 * please refer to arch/tile/kernel/vmlinux.lds.S.
7116 * 3) .rodata.* may be embedded into .text or .data sections.
7118 #define adj_init_size(start, end, size, pos, adj) \
7120 if (&start[0] <= &pos[0] && &pos[0] < &end[0] && size > adj) \
7124 adj_init_size(__init_begin, __init_end, init_data_size,
7125 _sinittext, init_code_size);
7126 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
7127 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
7128 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
7129 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
7131 #undef adj_init_size
7133 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7134 #ifdef CONFIG_HIGHMEM
7138 nr_free_pages() << (PAGE_SHIFT - 10),
7139 physpages << (PAGE_SHIFT - 10),
7140 codesize >> 10, datasize >> 10, rosize >> 10,
7141 (init_data_size + init_code_size) >> 10, bss_size >> 10,
7142 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
7143 totalcma_pages << (PAGE_SHIFT - 10),
7144 #ifdef CONFIG_HIGHMEM
7145 totalhigh_pages << (PAGE_SHIFT - 10),
7147 str ? ", " : "", str ? str : "");
7151 * set_dma_reserve - set the specified number of pages reserved in the first zone
7152 * @new_dma_reserve: The number of pages to mark reserved
7154 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7155 * In the DMA zone, a significant percentage may be consumed by kernel image
7156 * and other unfreeable allocations which can skew the watermarks badly. This
7157 * function may optionally be used to account for unfreeable pages in the
7158 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7159 * smaller per-cpu batchsize.
7161 void __init set_dma_reserve(unsigned long new_dma_reserve)
7163 dma_reserve = new_dma_reserve;
7166 void __init free_area_init(unsigned long *zones_size)
7168 zero_resv_unavail();
7169 free_area_init_node(0, zones_size,
7170 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
7173 static int page_alloc_cpu_dead(unsigned int cpu)
7176 lru_add_drain_cpu(cpu);
7180 * Spill the event counters of the dead processor
7181 * into the current processors event counters.
7182 * This artificially elevates the count of the current
7185 vm_events_fold_cpu(cpu);
7188 * Zero the differential counters of the dead processor
7189 * so that the vm statistics are consistent.
7191 * This is only okay since the processor is dead and cannot
7192 * race with what we are doing.
7194 cpu_vm_stats_fold(cpu);
7198 void __init page_alloc_init(void)
7202 ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD,
7203 "mm/page_alloc:dead", NULL,
7204 page_alloc_cpu_dead);
7209 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7210 * or min_free_kbytes changes.
7212 static void calculate_totalreserve_pages(void)
7214 struct pglist_data *pgdat;
7215 unsigned long reserve_pages = 0;
7216 enum zone_type i, j;
7218 for_each_online_pgdat(pgdat) {
7220 pgdat->totalreserve_pages = 0;
7222 for (i = 0; i < MAX_NR_ZONES; i++) {
7223 struct zone *zone = pgdat->node_zones + i;
7226 /* Find valid and maximum lowmem_reserve in the zone */
7227 for (j = i; j < MAX_NR_ZONES; j++) {
7228 if (zone->lowmem_reserve[j] > max)
7229 max = zone->lowmem_reserve[j];
7232 /* we treat the high watermark as reserved pages. */
7233 max += high_wmark_pages(zone);
7235 if (max > zone->managed_pages)
7236 max = zone->managed_pages;
7238 pgdat->totalreserve_pages += max;
7240 reserve_pages += max;
7243 totalreserve_pages = reserve_pages;
7247 * setup_per_zone_lowmem_reserve - called whenever
7248 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7249 * has a correct pages reserved value, so an adequate number of
7250 * pages are left in the zone after a successful __alloc_pages().
7252 static void setup_per_zone_lowmem_reserve(void)
7254 struct pglist_data *pgdat;
7255 enum zone_type j, idx;
7257 for_each_online_pgdat(pgdat) {
7258 for (j = 0; j < MAX_NR_ZONES; j++) {
7259 struct zone *zone = pgdat->node_zones + j;
7260 unsigned long managed_pages = zone->managed_pages;
7262 zone->lowmem_reserve[j] = 0;
7266 struct zone *lower_zone;
7269 lower_zone = pgdat->node_zones + idx;
7271 if (sysctl_lowmem_reserve_ratio[idx] < 1) {
7272 sysctl_lowmem_reserve_ratio[idx] = 0;
7273 lower_zone->lowmem_reserve[j] = 0;
7275 lower_zone->lowmem_reserve[j] =
7276 managed_pages / sysctl_lowmem_reserve_ratio[idx];
7278 managed_pages += lower_zone->managed_pages;
7283 /* update totalreserve_pages */
7284 calculate_totalreserve_pages();
7287 static void __setup_per_zone_wmarks(void)
7289 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
7290 unsigned long lowmem_pages = 0;
7292 unsigned long flags;
7294 /* Calculate total number of !ZONE_HIGHMEM pages */
7295 for_each_zone(zone) {
7296 if (!is_highmem(zone))
7297 lowmem_pages += zone->managed_pages;
7300 for_each_zone(zone) {
7303 spin_lock_irqsave(&zone->lock, flags);
7304 tmp = (u64)pages_min * zone->managed_pages;
7305 do_div(tmp, lowmem_pages);
7306 if (is_highmem(zone)) {
7308 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7309 * need highmem pages, so cap pages_min to a small
7312 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7313 * deltas control asynch page reclaim, and so should
7314 * not be capped for highmem.
7316 unsigned long min_pages;
7318 min_pages = zone->managed_pages / 1024;
7319 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
7320 zone->watermark[WMARK_MIN] = min_pages;
7323 * If it's a lowmem zone, reserve a number of pages
7324 * proportionate to the zone's size.
7326 zone->watermark[WMARK_MIN] = tmp;
7330 * Set the kswapd watermarks distance according to the
7331 * scale factor in proportion to available memory, but
7332 * ensure a minimum size on small systems.
7334 tmp = max_t(u64, tmp >> 2,
7335 mult_frac(zone->managed_pages,
7336 watermark_scale_factor, 10000));
7338 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
7339 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
7341 spin_unlock_irqrestore(&zone->lock, flags);
7344 /* update totalreserve_pages */
7345 calculate_totalreserve_pages();
7349 * setup_per_zone_wmarks - called when min_free_kbytes changes
7350 * or when memory is hot-{added|removed}
7352 * Ensures that the watermark[min,low,high] values for each zone are set
7353 * correctly with respect to min_free_kbytes.
7355 void setup_per_zone_wmarks(void)
7357 static DEFINE_SPINLOCK(lock);
7360 __setup_per_zone_wmarks();
7365 * Initialise min_free_kbytes.
7367 * For small machines we want it small (128k min). For large machines
7368 * we want it large (64MB max). But it is not linear, because network
7369 * bandwidth does not increase linearly with machine size. We use
7371 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7372 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7388 int __meminit init_per_zone_wmark_min(void)
7390 unsigned long lowmem_kbytes;
7391 int new_min_free_kbytes;
7393 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
7394 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
7396 if (new_min_free_kbytes > user_min_free_kbytes) {
7397 min_free_kbytes = new_min_free_kbytes;
7398 if (min_free_kbytes < 128)
7399 min_free_kbytes = 128;
7400 if (min_free_kbytes > 65536)
7401 min_free_kbytes = 65536;
7403 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7404 new_min_free_kbytes, user_min_free_kbytes);
7406 setup_per_zone_wmarks();
7407 refresh_zone_stat_thresholds();
7408 setup_per_zone_lowmem_reserve();
7411 setup_min_unmapped_ratio();
7412 setup_min_slab_ratio();
7415 khugepaged_min_free_kbytes_update();
7419 postcore_initcall(init_per_zone_wmark_min)
7422 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7423 * that we can call two helper functions whenever min_free_kbytes
7426 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
7427 void __user *buffer, size_t *length, loff_t *ppos)
7431 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7436 user_min_free_kbytes = min_free_kbytes;
7437 setup_per_zone_wmarks();
7442 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
7443 void __user *buffer, size_t *length, loff_t *ppos)
7447 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7452 setup_per_zone_wmarks();
7458 static void setup_min_unmapped_ratio(void)
7463 for_each_online_pgdat(pgdat)
7464 pgdat->min_unmapped_pages = 0;
7467 zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
7468 sysctl_min_unmapped_ratio) / 100;
7472 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
7473 void __user *buffer, size_t *length, loff_t *ppos)
7477 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7481 setup_min_unmapped_ratio();
7486 static void setup_min_slab_ratio(void)
7491 for_each_online_pgdat(pgdat)
7492 pgdat->min_slab_pages = 0;
7495 zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
7496 sysctl_min_slab_ratio) / 100;
7499 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
7500 void __user *buffer, size_t *length, loff_t *ppos)
7504 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7508 setup_min_slab_ratio();
7515 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7516 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7517 * whenever sysctl_lowmem_reserve_ratio changes.
7519 * The reserve ratio obviously has absolutely no relation with the
7520 * minimum watermarks. The lowmem reserve ratio can only make sense
7521 * if in function of the boot time zone sizes.
7523 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
7524 void __user *buffer, size_t *length, loff_t *ppos)
7526 proc_dointvec_minmax(table, write, buffer, length, ppos);
7527 setup_per_zone_lowmem_reserve();
7532 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7533 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7534 * pagelist can have before it gets flushed back to buddy allocator.
7536 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
7537 void __user *buffer, size_t *length, loff_t *ppos)
7540 int old_percpu_pagelist_fraction;
7543 mutex_lock(&pcp_batch_high_lock);
7544 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
7546 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
7547 if (!write || ret < 0)
7550 /* Sanity checking to avoid pcp imbalance */
7551 if (percpu_pagelist_fraction &&
7552 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
7553 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
7559 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
7562 for_each_populated_zone(zone) {
7565 for_each_possible_cpu(cpu)
7566 pageset_set_high_and_batch(zone,
7567 per_cpu_ptr(zone->pageset, cpu));
7570 mutex_unlock(&pcp_batch_high_lock);
7575 int hashdist = HASHDIST_DEFAULT;
7577 static int __init set_hashdist(char *str)
7581 hashdist = simple_strtoul(str, &str, 0);
7584 __setup("hashdist=", set_hashdist);
7587 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7589 * Returns the number of pages that arch has reserved but
7590 * is not known to alloc_large_system_hash().
7592 static unsigned long __init arch_reserved_kernel_pages(void)
7599 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7600 * machines. As memory size is increased the scale is also increased but at
7601 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7602 * quadruples the scale is increased by one, which means the size of hash table
7603 * only doubles, instead of quadrupling as well.
7604 * Because 32-bit systems cannot have large physical memory, where this scaling
7605 * makes sense, it is disabled on such platforms.
7607 #if __BITS_PER_LONG > 32
7608 #define ADAPT_SCALE_BASE (64ul << 30)
7609 #define ADAPT_SCALE_SHIFT 2
7610 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7614 * allocate a large system hash table from bootmem
7615 * - it is assumed that the hash table must contain an exact power-of-2
7616 * quantity of entries
7617 * - limit is the number of hash buckets, not the total allocation size
7619 void *__init alloc_large_system_hash(const char *tablename,
7620 unsigned long bucketsize,
7621 unsigned long numentries,
7624 unsigned int *_hash_shift,
7625 unsigned int *_hash_mask,
7626 unsigned long low_limit,
7627 unsigned long high_limit)
7629 unsigned long long max = high_limit;
7630 unsigned long log2qty, size;
7634 /* allow the kernel cmdline to have a say */
7636 /* round applicable memory size up to nearest megabyte */
7637 numentries = nr_kernel_pages;
7638 numentries -= arch_reserved_kernel_pages();
7640 /* It isn't necessary when PAGE_SIZE >= 1MB */
7641 if (PAGE_SHIFT < 20)
7642 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
7644 #if __BITS_PER_LONG > 32
7646 unsigned long adapt;
7648 for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries;
7649 adapt <<= ADAPT_SCALE_SHIFT)
7654 /* limit to 1 bucket per 2^scale bytes of low memory */
7655 if (scale > PAGE_SHIFT)
7656 numentries >>= (scale - PAGE_SHIFT);
7658 numentries <<= (PAGE_SHIFT - scale);
7660 /* Make sure we've got at least a 0-order allocation.. */
7661 if (unlikely(flags & HASH_SMALL)) {
7662 /* Makes no sense without HASH_EARLY */
7663 WARN_ON(!(flags & HASH_EARLY));
7664 if (!(numentries >> *_hash_shift)) {
7665 numentries = 1UL << *_hash_shift;
7666 BUG_ON(!numentries);
7668 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
7669 numentries = PAGE_SIZE / bucketsize;
7671 numentries = roundup_pow_of_two(numentries);
7673 /* limit allocation size to 1/16 total memory by default */
7675 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
7676 do_div(max, bucketsize);
7678 max = min(max, 0x80000000ULL);
7680 if (numentries < low_limit)
7681 numentries = low_limit;
7682 if (numentries > max)
7685 log2qty = ilog2(numentries);
7687 gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
7689 size = bucketsize << log2qty;
7690 if (flags & HASH_EARLY) {
7691 if (flags & HASH_ZERO)
7692 table = memblock_virt_alloc_nopanic(size, 0);
7694 table = memblock_virt_alloc_raw(size, 0);
7695 } else if (hashdist) {
7696 table = __vmalloc(size, gfp_flags, PAGE_KERNEL);
7699 * If bucketsize is not a power-of-two, we may free
7700 * some pages at the end of hash table which
7701 * alloc_pages_exact() automatically does
7703 if (get_order(size) < MAX_ORDER) {
7704 table = alloc_pages_exact(size, gfp_flags);
7705 kmemleak_alloc(table, size, 1, gfp_flags);
7708 } while (!table && size > PAGE_SIZE && --log2qty);
7711 panic("Failed to allocate %s hash table\n", tablename);
7713 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7714 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7717 *_hash_shift = log2qty;
7719 *_hash_mask = (1 << log2qty) - 1;
7725 * This function checks whether pageblock includes unmovable pages or not.
7726 * If @count is not zero, it is okay to include less @count unmovable pages
7728 * PageLRU check without isolation or lru_lock could race so that
7729 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7730 * check without lock_page also may miss some movable non-lru pages at
7731 * race condition. So you can't expect this function should be exact.
7733 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7735 bool skip_hwpoisoned_pages)
7737 unsigned long pfn, iter, found;
7740 * TODO we could make this much more efficient by not checking every
7741 * page in the range if we know all of them are in MOVABLE_ZONE and
7742 * that the movable zone guarantees that pages are migratable but
7743 * the later is not the case right now unfortunatelly. E.g. movablecore
7744 * can still lead to having bootmem allocations in zone_movable.
7748 * CMA allocations (alloc_contig_range) really need to mark isolate
7749 * CMA pageblocks even when they are not movable in fact so consider
7750 * them movable here.
7752 if (is_migrate_cma(migratetype) &&
7753 is_migrate_cma(get_pageblock_migratetype(page)))
7756 pfn = page_to_pfn(page);
7757 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7758 unsigned long check = pfn + iter;
7760 if (!pfn_valid_within(check))
7763 page = pfn_to_page(check);
7765 if (PageReserved(page))
7769 * If the zone is movable and we have ruled out all reserved
7770 * pages then it should be reasonably safe to assume the rest
7773 if (zone_idx(zone) == ZONE_MOVABLE)
7777 * Hugepages are not in LRU lists, but they're movable.
7778 * We need not scan over tail pages bacause we don't
7779 * handle each tail page individually in migration.
7781 if (PageHuge(page)) {
7782 struct page *head = compound_head(page);
7783 unsigned int skip_pages;
7785 if (!hugepage_migration_supported(page_hstate(head)))
7788 skip_pages = (1 << compound_order(head)) - (page - head);
7789 iter += skip_pages - 1;
7794 * We can't use page_count without pin a page
7795 * because another CPU can free compound page.
7796 * This check already skips compound tails of THP
7797 * because their page->_refcount is zero at all time.
7799 if (!page_ref_count(page)) {
7800 if (PageBuddy(page))
7801 iter += (1 << page_order(page)) - 1;
7806 * The HWPoisoned page may be not in buddy system, and
7807 * page_count() is not 0.
7809 if (skip_hwpoisoned_pages && PageHWPoison(page))
7812 if (__PageMovable(page))
7818 * If there are RECLAIMABLE pages, we need to check
7819 * it. But now, memory offline itself doesn't call
7820 * shrink_node_slabs() and it still to be fixed.
7823 * If the page is not RAM, page_count()should be 0.
7824 * we don't need more check. This is an _used_ not-movable page.
7826 * The problematic thing here is PG_reserved pages. PG_reserved
7827 * is set to both of a memory hole page and a _used_ kernel
7835 WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE);
7839 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7841 static unsigned long pfn_max_align_down(unsigned long pfn)
7843 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7844 pageblock_nr_pages) - 1);
7847 static unsigned long pfn_max_align_up(unsigned long pfn)
7849 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7850 pageblock_nr_pages));
7853 /* [start, end) must belong to a single zone. */
7854 static int __alloc_contig_migrate_range(struct compact_control *cc,
7855 unsigned long start, unsigned long end)
7857 /* This function is based on compact_zone() from compaction.c. */
7858 unsigned long nr_reclaimed;
7859 unsigned long pfn = start;
7860 unsigned int tries = 0;
7865 while (pfn < end || !list_empty(&cc->migratepages)) {
7866 if (fatal_signal_pending(current)) {
7871 if (list_empty(&cc->migratepages)) {
7872 cc->nr_migratepages = 0;
7873 pfn = isolate_migratepages_range(cc, pfn, end);
7879 } else if (++tries == 5) {
7880 ret = ret < 0 ? ret : -EBUSY;
7884 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7886 cc->nr_migratepages -= nr_reclaimed;
7888 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7889 NULL, 0, cc->mode, MR_CONTIG_RANGE);
7892 putback_movable_pages(&cc->migratepages);
7899 * alloc_contig_range() -- tries to allocate given range of pages
7900 * @start: start PFN to allocate
7901 * @end: one-past-the-last PFN to allocate
7902 * @migratetype: migratetype of the underlaying pageblocks (either
7903 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7904 * in range must have the same migratetype and it must
7905 * be either of the two.
7906 * @gfp_mask: GFP mask to use during compaction
7908 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7909 * aligned. The PFN range must belong to a single zone.
7911 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
7912 * pageblocks in the range. Once isolated, the pageblocks should not
7913 * be modified by others.
7915 * Returns zero on success or negative error code. On success all
7916 * pages which PFN is in [start, end) are allocated for the caller and
7917 * need to be freed with free_contig_range().
7919 int alloc_contig_range(unsigned long start, unsigned long end,
7920 unsigned migratetype, gfp_t gfp_mask)
7922 unsigned long outer_start, outer_end;
7926 struct compact_control cc = {
7927 .nr_migratepages = 0,
7929 .zone = page_zone(pfn_to_page(start)),
7930 .mode = MIGRATE_SYNC,
7931 .ignore_skip_hint = true,
7932 .no_set_skip_hint = true,
7933 .gfp_mask = current_gfp_context(gfp_mask),
7935 INIT_LIST_HEAD(&cc.migratepages);
7938 * What we do here is we mark all pageblocks in range as
7939 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7940 * have different sizes, and due to the way page allocator
7941 * work, we align the range to biggest of the two pages so
7942 * that page allocator won't try to merge buddies from
7943 * different pageblocks and change MIGRATE_ISOLATE to some
7944 * other migration type.
7946 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7947 * migrate the pages from an unaligned range (ie. pages that
7948 * we are interested in). This will put all the pages in
7949 * range back to page allocator as MIGRATE_ISOLATE.
7951 * When this is done, we take the pages in range from page
7952 * allocator removing them from the buddy system. This way
7953 * page allocator will never consider using them.
7955 * This lets us mark the pageblocks back as
7956 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7957 * aligned range but not in the unaligned, original range are
7958 * put back to page allocator so that buddy can use them.
7961 ret = start_isolate_page_range(pfn_max_align_down(start),
7962 pfn_max_align_up(end), migratetype,
7968 * In case of -EBUSY, we'd like to know which page causes problem.
7969 * So, just fall through. test_pages_isolated() has a tracepoint
7970 * which will report the busy page.
7972 * It is possible that busy pages could become available before
7973 * the call to test_pages_isolated, and the range will actually be
7974 * allocated. So, if we fall through be sure to clear ret so that
7975 * -EBUSY is not accidentally used or returned to caller.
7977 ret = __alloc_contig_migrate_range(&cc, start, end);
7978 if (ret && ret != -EBUSY)
7983 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7984 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7985 * more, all pages in [start, end) are free in page allocator.
7986 * What we are going to do is to allocate all pages from
7987 * [start, end) (that is remove them from page allocator).
7989 * The only problem is that pages at the beginning and at the
7990 * end of interesting range may be not aligned with pages that
7991 * page allocator holds, ie. they can be part of higher order
7992 * pages. Because of this, we reserve the bigger range and
7993 * once this is done free the pages we are not interested in.
7995 * We don't have to hold zone->lock here because the pages are
7996 * isolated thus they won't get removed from buddy.
7999 lru_add_drain_all();
8000 drain_all_pages(cc.zone);
8003 outer_start = start;
8004 while (!PageBuddy(pfn_to_page(outer_start))) {
8005 if (++order >= MAX_ORDER) {
8006 outer_start = start;
8009 outer_start &= ~0UL << order;
8012 if (outer_start != start) {
8013 order = page_order(pfn_to_page(outer_start));
8016 * outer_start page could be small order buddy page and
8017 * it doesn't include start page. Adjust outer_start
8018 * in this case to report failed page properly
8019 * on tracepoint in test_pages_isolated()
8021 if (outer_start + (1UL << order) <= start)
8022 outer_start = start;
8025 /* Make sure the range is really isolated. */
8026 if (test_pages_isolated(outer_start, end, false)) {
8027 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8028 __func__, outer_start, end);
8033 /* Grab isolated pages from freelists. */
8034 outer_end = isolate_freepages_range(&cc, outer_start, end);
8040 /* Free head and tail (if any) */
8041 if (start != outer_start)
8042 free_contig_range(outer_start, start - outer_start);
8043 if (end != outer_end)
8044 free_contig_range(end, outer_end - end);
8047 undo_isolate_page_range(pfn_max_align_down(start),
8048 pfn_max_align_up(end), migratetype);
8052 void free_contig_range(unsigned long pfn, unsigned nr_pages)
8054 unsigned int count = 0;
8056 for (; nr_pages--; pfn++) {
8057 struct page *page = pfn_to_page(pfn);
8059 count += page_count(page) != 1;
8062 WARN(count != 0, "%d pages are still in use!\n", count);
8067 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8068 * page high values need to be recalulated.
8070 void __meminit zone_pcp_update(struct zone *zone)
8073 mutex_lock(&pcp_batch_high_lock);
8074 for_each_possible_cpu(cpu)
8075 pageset_set_high_and_batch(zone,
8076 per_cpu_ptr(zone->pageset, cpu));
8077 mutex_unlock(&pcp_batch_high_lock);
8080 void zone_pcp_reset(struct zone *zone)
8082 unsigned long flags;
8084 struct per_cpu_pageset *pset;
8086 /* avoid races with drain_pages() */
8087 local_irq_save(flags);
8088 if (zone->pageset != &boot_pageset) {
8089 for_each_online_cpu(cpu) {
8090 pset = per_cpu_ptr(zone->pageset, cpu);
8091 drain_zonestat(zone, pset);
8093 free_percpu(zone->pageset);
8094 zone->pageset = &boot_pageset;
8096 local_irq_restore(flags);
8099 #ifdef CONFIG_MEMORY_HOTREMOVE
8101 * All pages in the range must be in a single zone and isolated
8102 * before calling this.
8105 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
8109 unsigned int order, i;
8111 unsigned long flags;
8112 /* find the first valid pfn */
8113 for (pfn = start_pfn; pfn < end_pfn; pfn++)
8118 offline_mem_sections(pfn, end_pfn);
8119 zone = page_zone(pfn_to_page(pfn));
8120 spin_lock_irqsave(&zone->lock, flags);
8122 while (pfn < end_pfn) {
8123 if (!pfn_valid(pfn)) {
8127 page = pfn_to_page(pfn);
8129 * The HWPoisoned page may be not in buddy system, and
8130 * page_count() is not 0.
8132 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
8134 SetPageReserved(page);
8138 BUG_ON(page_count(page));
8139 BUG_ON(!PageBuddy(page));
8140 order = page_order(page);
8141 #ifdef CONFIG_DEBUG_VM
8142 pr_info("remove from free list %lx %d %lx\n",
8143 pfn, 1 << order, end_pfn);
8145 list_del(&page->lru);
8146 rmv_page_order(page);
8147 zone->free_area[order].nr_free--;
8148 for (i = 0; i < (1 << order); i++)
8149 SetPageReserved((page+i));
8150 pfn += (1 << order);
8152 spin_unlock_irqrestore(&zone->lock, flags);
8156 bool is_free_buddy_page(struct page *page)
8158 struct zone *zone = page_zone(page);
8159 unsigned long pfn = page_to_pfn(page);
8160 unsigned long flags;
8163 spin_lock_irqsave(&zone->lock, flags);
8164 for (order = 0; order < MAX_ORDER; order++) {
8165 struct page *page_head = page - (pfn & ((1 << order) - 1));
8167 if (PageBuddy(page_head) && page_order(page_head) >= order)
8170 spin_unlock_irqrestore(&zone->lock, flags);
8172 return order < MAX_ORDER;
8175 #ifdef CONFIG_MEMORY_FAILURE
8177 * Set PG_hwpoison flag if a given page is confirmed to be a free page. This
8178 * test is performed under the zone lock to prevent a race against page
8181 bool set_hwpoison_free_buddy_page(struct page *page)
8183 struct zone *zone = page_zone(page);
8184 unsigned long pfn = page_to_pfn(page);
8185 unsigned long flags;
8187 bool hwpoisoned = false;
8189 spin_lock_irqsave(&zone->lock, flags);
8190 for (order = 0; order < MAX_ORDER; order++) {
8191 struct page *page_head = page - (pfn & ((1 << order) - 1));
8193 if (PageBuddy(page_head) && page_order(page_head) >= order) {
8194 if (!TestSetPageHWPoison(page))
8199 spin_unlock_irqrestore(&zone->lock, flags);