2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/memremap.h>
47 #include <linux/stop_machine.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page_ext.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
67 #include <asm/sections.h>
68 #include <asm/tlbflush.h>
69 #include <asm/div64.h>
72 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
73 static DEFINE_MUTEX(pcp_batch_high_lock);
74 #define MIN_PERCPU_PAGELIST_FRACTION (8)
76 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
77 DEFINE_PER_CPU(int, numa_node);
78 EXPORT_PER_CPU_SYMBOL(numa_node);
81 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
83 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
84 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
85 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
86 * defined in <linux/topology.h>.
88 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
89 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
90 int _node_numa_mem_[MAX_NUMNODES];
94 * Array of node states.
96 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
97 [N_POSSIBLE] = NODE_MASK_ALL,
98 [N_ONLINE] = { { [0] = 1UL } },
100 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
101 #ifdef CONFIG_HIGHMEM
102 [N_HIGH_MEMORY] = { { [0] = 1UL } },
104 #ifdef CONFIG_MOVABLE_NODE
105 [N_MEMORY] = { { [0] = 1UL } },
107 [N_CPU] = { { [0] = 1UL } },
110 EXPORT_SYMBOL(node_states);
112 /* Protect totalram_pages and zone->managed_pages */
113 static DEFINE_SPINLOCK(managed_page_count_lock);
115 unsigned long totalram_pages __read_mostly;
116 unsigned long totalreserve_pages __read_mostly;
117 unsigned long totalcma_pages __read_mostly;
119 int percpu_pagelist_fraction;
120 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
123 * A cached value of the page's pageblock's migratetype, used when the page is
124 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
125 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
126 * Also the migratetype set in the page does not necessarily match the pcplist
127 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
128 * other index - this ensures that it will be put on the correct CMA freelist.
130 static inline int get_pcppage_migratetype(struct page *page)
135 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
137 page->index = migratetype;
140 #ifdef CONFIG_PM_SLEEP
142 * The following functions are used by the suspend/hibernate code to temporarily
143 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
144 * while devices are suspended. To avoid races with the suspend/hibernate code,
145 * they should always be called with pm_mutex held (gfp_allowed_mask also should
146 * only be modified with pm_mutex held, unless the suspend/hibernate code is
147 * guaranteed not to run in parallel with that modification).
150 static gfp_t saved_gfp_mask;
152 void pm_restore_gfp_mask(void)
154 WARN_ON(!mutex_is_locked(&pm_mutex));
155 if (saved_gfp_mask) {
156 gfp_allowed_mask = saved_gfp_mask;
161 void pm_restrict_gfp_mask(void)
163 WARN_ON(!mutex_is_locked(&pm_mutex));
164 WARN_ON(saved_gfp_mask);
165 saved_gfp_mask = gfp_allowed_mask;
166 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
169 bool pm_suspended_storage(void)
171 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
175 #endif /* CONFIG_PM_SLEEP */
177 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
178 unsigned int pageblock_order __read_mostly;
181 static void __free_pages_ok(struct page *page, unsigned int order);
184 * results with 256, 32 in the lowmem_reserve sysctl:
185 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
186 * 1G machine -> (16M dma, 784M normal, 224M high)
187 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
188 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
189 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
191 * TBD: should special case ZONE_DMA32 machines here - in those we normally
192 * don't need any ZONE_NORMAL reservation
194 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
195 #ifdef CONFIG_ZONE_DMA
198 #ifdef CONFIG_ZONE_DMA32
201 #ifdef CONFIG_HIGHMEM
207 EXPORT_SYMBOL(totalram_pages);
209 static char * const zone_names[MAX_NR_ZONES] = {
210 #ifdef CONFIG_ZONE_DMA
213 #ifdef CONFIG_ZONE_DMA32
217 #ifdef CONFIG_HIGHMEM
221 #ifdef CONFIG_ZONE_DEVICE
226 char * const migratetype_names[MIGRATE_TYPES] = {
234 #ifdef CONFIG_MEMORY_ISOLATION
239 compound_page_dtor * const compound_page_dtors[] = {
242 #ifdef CONFIG_HUGETLB_PAGE
245 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
250 int min_free_kbytes = 1024;
251 int user_min_free_kbytes = -1;
252 int watermark_scale_factor = 10;
254 static unsigned long __meminitdata nr_kernel_pages;
255 static unsigned long __meminitdata nr_all_pages;
256 static unsigned long __meminitdata dma_reserve;
258 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
259 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
260 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
261 static unsigned long __initdata required_kernelcore;
262 static unsigned long __initdata required_movablecore;
263 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
264 static bool mirrored_kernelcore;
266 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
268 EXPORT_SYMBOL(movable_zone);
269 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
272 int nr_node_ids __read_mostly = MAX_NUMNODES;
273 int nr_online_nodes __read_mostly = 1;
274 EXPORT_SYMBOL(nr_node_ids);
275 EXPORT_SYMBOL(nr_online_nodes);
278 int page_group_by_mobility_disabled __read_mostly;
280 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
281 static inline void reset_deferred_meminit(pg_data_t *pgdat)
283 pgdat->first_deferred_pfn = ULONG_MAX;
286 /* Returns true if the struct page for the pfn is uninitialised */
287 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
289 int nid = early_pfn_to_nid(pfn);
291 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
297 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
299 if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
306 * Returns false when the remaining initialisation should be deferred until
307 * later in the boot cycle when it can be parallelised.
309 static inline bool update_defer_init(pg_data_t *pgdat,
310 unsigned long pfn, unsigned long zone_end,
311 unsigned long *nr_initialised)
313 unsigned long max_initialise;
315 /* Always populate low zones for address-contrained allocations */
316 if (zone_end < pgdat_end_pfn(pgdat))
319 * Initialise at least 2G of a node but also take into account that
320 * two large system hashes that can take up 1GB for 0.25TB/node.
322 max_initialise = max(2UL << (30 - PAGE_SHIFT),
323 (pgdat->node_spanned_pages >> 8));
326 if ((*nr_initialised > max_initialise) &&
327 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
328 pgdat->first_deferred_pfn = pfn;
335 static inline void reset_deferred_meminit(pg_data_t *pgdat)
339 static inline bool early_page_uninitialised(unsigned long pfn)
344 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
349 static inline bool update_defer_init(pg_data_t *pgdat,
350 unsigned long pfn, unsigned long zone_end,
351 unsigned long *nr_initialised)
357 /* Return a pointer to the bitmap storing bits affecting a block of pages */
358 static inline unsigned long *get_pageblock_bitmap(struct page *page,
361 #ifdef CONFIG_SPARSEMEM
362 return __pfn_to_section(pfn)->pageblock_flags;
364 return page_zone(page)->pageblock_flags;
365 #endif /* CONFIG_SPARSEMEM */
368 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
370 #ifdef CONFIG_SPARSEMEM
371 pfn &= (PAGES_PER_SECTION-1);
372 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
374 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
375 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
376 #endif /* CONFIG_SPARSEMEM */
380 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
381 * @page: The page within the block of interest
382 * @pfn: The target page frame number
383 * @end_bitidx: The last bit of interest to retrieve
384 * @mask: mask of bits that the caller is interested in
386 * Return: pageblock_bits flags
388 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
390 unsigned long end_bitidx,
393 unsigned long *bitmap;
394 unsigned long bitidx, word_bitidx;
397 bitmap = get_pageblock_bitmap(page, pfn);
398 bitidx = pfn_to_bitidx(page, pfn);
399 word_bitidx = bitidx / BITS_PER_LONG;
400 bitidx &= (BITS_PER_LONG-1);
402 word = bitmap[word_bitidx];
403 bitidx += end_bitidx;
404 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
407 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
408 unsigned long end_bitidx,
411 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
414 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
416 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
420 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
421 * @page: The page within the block of interest
422 * @flags: The flags to set
423 * @pfn: The target page frame number
424 * @end_bitidx: The last bit of interest
425 * @mask: mask of bits that the caller is interested in
427 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
429 unsigned long end_bitidx,
432 unsigned long *bitmap;
433 unsigned long bitidx, word_bitidx;
434 unsigned long old_word, word;
436 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
438 bitmap = get_pageblock_bitmap(page, pfn);
439 bitidx = pfn_to_bitidx(page, pfn);
440 word_bitidx = bitidx / BITS_PER_LONG;
441 bitidx &= (BITS_PER_LONG-1);
443 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
445 bitidx += end_bitidx;
446 mask <<= (BITS_PER_LONG - bitidx - 1);
447 flags <<= (BITS_PER_LONG - bitidx - 1);
449 word = READ_ONCE(bitmap[word_bitidx]);
451 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
452 if (word == old_word)
458 void set_pageblock_migratetype(struct page *page, int migratetype)
460 if (unlikely(page_group_by_mobility_disabled &&
461 migratetype < MIGRATE_PCPTYPES))
462 migratetype = MIGRATE_UNMOVABLE;
464 set_pageblock_flags_group(page, (unsigned long)migratetype,
465 PB_migrate, PB_migrate_end);
468 #ifdef CONFIG_DEBUG_VM
469 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
473 unsigned long pfn = page_to_pfn(page);
474 unsigned long sp, start_pfn;
477 seq = zone_span_seqbegin(zone);
478 start_pfn = zone->zone_start_pfn;
479 sp = zone->spanned_pages;
480 if (!zone_spans_pfn(zone, pfn))
482 } while (zone_span_seqretry(zone, seq));
485 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
486 pfn, zone_to_nid(zone), zone->name,
487 start_pfn, start_pfn + sp);
492 static int page_is_consistent(struct zone *zone, struct page *page)
494 if (!pfn_valid_within(page_to_pfn(page)))
496 if (zone != page_zone(page))
502 * Temporary debugging check for pages not lying within a given zone.
504 static int bad_range(struct zone *zone, struct page *page)
506 if (page_outside_zone_boundaries(zone, page))
508 if (!page_is_consistent(zone, page))
514 static inline int bad_range(struct zone *zone, struct page *page)
520 static void bad_page(struct page *page, const char *reason,
521 unsigned long bad_flags)
523 static unsigned long resume;
524 static unsigned long nr_shown;
525 static unsigned long nr_unshown;
528 * Allow a burst of 60 reports, then keep quiet for that minute;
529 * or allow a steady drip of one report per second.
531 if (nr_shown == 60) {
532 if (time_before(jiffies, resume)) {
538 "BUG: Bad page state: %lu messages suppressed\n",
545 resume = jiffies + 60 * HZ;
547 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
548 current->comm, page_to_pfn(page));
549 __dump_page(page, reason);
550 bad_flags &= page->flags;
552 pr_alert("bad because of flags: %#lx(%pGp)\n",
553 bad_flags, &bad_flags);
554 dump_page_owner(page);
559 /* Leave bad fields for debug, except PageBuddy could make trouble */
560 page_mapcount_reset(page); /* remove PageBuddy */
561 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
565 * Higher-order pages are called "compound pages". They are structured thusly:
567 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
569 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
570 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
572 * The first tail page's ->compound_dtor holds the offset in array of compound
573 * page destructors. See compound_page_dtors.
575 * The first tail page's ->compound_order holds the order of allocation.
576 * This usage means that zero-order pages may not be compound.
579 void free_compound_page(struct page *page)
581 __free_pages_ok(page, compound_order(page));
584 void prep_compound_page(struct page *page, unsigned int order)
587 int nr_pages = 1 << order;
589 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
590 set_compound_order(page, order);
592 for (i = 1; i < nr_pages; i++) {
593 struct page *p = page + i;
594 set_page_count(p, 0);
595 p->mapping = TAIL_MAPPING;
596 set_compound_head(p, page);
598 atomic_set(compound_mapcount_ptr(page), -1);
601 #ifdef CONFIG_DEBUG_PAGEALLOC
602 unsigned int _debug_guardpage_minorder;
603 bool _debug_pagealloc_enabled __read_mostly
604 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
605 EXPORT_SYMBOL(_debug_pagealloc_enabled);
606 bool _debug_guardpage_enabled __read_mostly;
608 static int __init early_debug_pagealloc(char *buf)
612 return kstrtobool(buf, &_debug_pagealloc_enabled);
614 early_param("debug_pagealloc", early_debug_pagealloc);
616 static bool need_debug_guardpage(void)
618 /* If we don't use debug_pagealloc, we don't need guard page */
619 if (!debug_pagealloc_enabled())
625 static void init_debug_guardpage(void)
627 if (!debug_pagealloc_enabled())
630 _debug_guardpage_enabled = true;
633 struct page_ext_operations debug_guardpage_ops = {
634 .need = need_debug_guardpage,
635 .init = init_debug_guardpage,
638 static int __init debug_guardpage_minorder_setup(char *buf)
642 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
643 pr_err("Bad debug_guardpage_minorder value\n");
646 _debug_guardpage_minorder = res;
647 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
650 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
652 static inline void set_page_guard(struct zone *zone, struct page *page,
653 unsigned int order, int migratetype)
655 struct page_ext *page_ext;
657 if (!debug_guardpage_enabled())
660 page_ext = lookup_page_ext(page);
661 if (unlikely(!page_ext))
664 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
666 INIT_LIST_HEAD(&page->lru);
667 set_page_private(page, order);
668 /* Guard pages are not available for any usage */
669 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
672 static inline void clear_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 page_ext = lookup_page_ext(page);
681 if (unlikely(!page_ext))
684 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
686 set_page_private(page, 0);
687 if (!is_migrate_isolate(migratetype))
688 __mod_zone_freepage_state(zone, (1 << order), migratetype);
691 struct page_ext_operations debug_guardpage_ops = { NULL, };
692 static inline void set_page_guard(struct zone *zone, struct page *page,
693 unsigned int order, int migratetype) {}
694 static inline void clear_page_guard(struct zone *zone, struct page *page,
695 unsigned int order, int migratetype) {}
698 static inline void set_page_order(struct page *page, unsigned int order)
700 set_page_private(page, order);
701 __SetPageBuddy(page);
704 static inline void rmv_page_order(struct page *page)
706 __ClearPageBuddy(page);
707 set_page_private(page, 0);
711 * This function checks whether a page is free && is the buddy
712 * we can do coalesce a page and its buddy if
713 * (a) the buddy is not in a hole &&
714 * (b) the buddy is in the buddy system &&
715 * (c) a page and its buddy have the same order &&
716 * (d) a page and its buddy are in the same zone.
718 * For recording whether a page is in the buddy system, we set ->_mapcount
719 * PAGE_BUDDY_MAPCOUNT_VALUE.
720 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
721 * serialized by zone->lock.
723 * For recording page's order, we use page_private(page).
725 static inline int page_is_buddy(struct page *page, struct page *buddy,
728 if (!pfn_valid_within(page_to_pfn(buddy)))
731 if (page_is_guard(buddy) && page_order(buddy) == order) {
732 if (page_zone_id(page) != page_zone_id(buddy))
735 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
740 if (PageBuddy(buddy) && page_order(buddy) == order) {
742 * zone check is done late to avoid uselessly
743 * calculating zone/node ids for pages that could
746 if (page_zone_id(page) != page_zone_id(buddy))
749 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
757 * Freeing function for a buddy system allocator.
759 * The concept of a buddy system is to maintain direct-mapped table
760 * (containing bit values) for memory blocks of various "orders".
761 * The bottom level table contains the map for the smallest allocatable
762 * units of memory (here, pages), and each level above it describes
763 * pairs of units from the levels below, hence, "buddies".
764 * At a high level, all that happens here is marking the table entry
765 * at the bottom level available, and propagating the changes upward
766 * as necessary, plus some accounting needed to play nicely with other
767 * parts of the VM system.
768 * At each level, we keep a list of pages, which are heads of continuous
769 * free pages of length of (1 << order) and marked with _mapcount
770 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
772 * So when we are allocating or freeing one, we can derive the state of the
773 * other. That is, if we allocate a small block, and both were
774 * free, the remainder of the region must be split into blocks.
775 * If a block is freed, and its buddy is also free, then this
776 * triggers coalescing into a block of larger size.
781 static inline void __free_one_page(struct page *page,
783 struct zone *zone, unsigned int order,
786 unsigned long page_idx;
787 unsigned long combined_idx;
788 unsigned long uninitialized_var(buddy_idx);
790 unsigned int max_order;
792 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
794 VM_BUG_ON(!zone_is_initialized(zone));
795 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
797 VM_BUG_ON(migratetype == -1);
798 if (likely(!is_migrate_isolate(migratetype)))
799 __mod_zone_freepage_state(zone, 1 << order, migratetype);
801 page_idx = pfn & ((1 << MAX_ORDER) - 1);
803 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
804 VM_BUG_ON_PAGE(bad_range(zone, page), page);
807 while (order < max_order - 1) {
808 buddy_idx = __find_buddy_index(page_idx, order);
809 buddy = page + (buddy_idx - page_idx);
810 if (!page_is_buddy(page, buddy, order))
813 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
814 * merge with it and move up one order.
816 if (page_is_guard(buddy)) {
817 clear_page_guard(zone, buddy, order, migratetype);
819 list_del(&buddy->lru);
820 zone->free_area[order].nr_free--;
821 rmv_page_order(buddy);
823 combined_idx = buddy_idx & page_idx;
824 page = page + (combined_idx - page_idx);
825 page_idx = combined_idx;
828 if (max_order < MAX_ORDER) {
829 /* If we are here, it means order is >= pageblock_order.
830 * We want to prevent merge between freepages on isolate
831 * pageblock and normal pageblock. Without this, pageblock
832 * isolation could cause incorrect freepage or CMA accounting.
834 * We don't want to hit this code for the more frequent
837 if (unlikely(has_isolate_pageblock(zone))) {
840 buddy_idx = __find_buddy_index(page_idx, order);
841 buddy = page + (buddy_idx - page_idx);
842 buddy_mt = get_pageblock_migratetype(buddy);
844 if (migratetype != buddy_mt
845 && (is_migrate_isolate(migratetype) ||
846 is_migrate_isolate(buddy_mt)))
850 goto continue_merging;
854 set_page_order(page, order);
857 * If this is not the largest possible page, check if the buddy
858 * of the next-highest order is free. If it is, it's possible
859 * that pages are being freed that will coalesce soon. In case,
860 * that is happening, add the free page to the tail of the list
861 * so it's less likely to be used soon and more likely to be merged
862 * as a higher order page
864 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
865 struct page *higher_page, *higher_buddy;
866 combined_idx = buddy_idx & page_idx;
867 higher_page = page + (combined_idx - page_idx);
868 buddy_idx = __find_buddy_index(combined_idx, order + 1);
869 higher_buddy = higher_page + (buddy_idx - combined_idx);
870 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
871 list_add_tail(&page->lru,
872 &zone->free_area[order].free_list[migratetype]);
877 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
879 zone->free_area[order].nr_free++;
883 * A bad page could be due to a number of fields. Instead of multiple branches,
884 * try and check multiple fields with one check. The caller must do a detailed
885 * check if necessary.
887 static inline bool page_expected_state(struct page *page,
888 unsigned long check_flags)
890 if (unlikely(atomic_read(&page->_mapcount) != -1))
893 if (unlikely((unsigned long)page->mapping |
894 page_ref_count(page) |
896 (unsigned long)page->mem_cgroup |
898 (page->flags & check_flags)))
904 static void free_pages_check_bad(struct page *page)
906 const char *bad_reason;
907 unsigned long bad_flags;
912 if (unlikely(atomic_read(&page->_mapcount) != -1))
913 bad_reason = "nonzero mapcount";
914 if (unlikely(page->mapping != NULL))
915 bad_reason = "non-NULL mapping";
916 if (unlikely(page_ref_count(page) != 0))
917 bad_reason = "nonzero _refcount";
918 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
919 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
920 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
923 if (unlikely(page->mem_cgroup))
924 bad_reason = "page still charged to cgroup";
926 bad_page(page, bad_reason, bad_flags);
929 static inline int free_pages_check(struct page *page)
931 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
934 /* Something has gone sideways, find it */
935 free_pages_check_bad(page);
939 static int free_tail_pages_check(struct page *head_page, struct page *page)
944 * We rely page->lru.next never has bit 0 set, unless the page
945 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
947 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
949 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
953 switch (page - head_page) {
955 /* the first tail page: ->mapping is compound_mapcount() */
956 if (unlikely(compound_mapcount(page))) {
957 bad_page(page, "nonzero compound_mapcount", 0);
963 * the second tail page: ->mapping is
964 * page_deferred_list().next -- ignore value.
968 if (page->mapping != TAIL_MAPPING) {
969 bad_page(page, "corrupted mapping in tail page", 0);
974 if (unlikely(!PageTail(page))) {
975 bad_page(page, "PageTail not set", 0);
978 if (unlikely(compound_head(page) != head_page)) {
979 bad_page(page, "compound_head not consistent", 0);
984 page->mapping = NULL;
985 clear_compound_head(page);
989 static __always_inline bool free_pages_prepare(struct page *page,
990 unsigned int order, bool check_free)
994 VM_BUG_ON_PAGE(PageTail(page), page);
996 trace_mm_page_free(page, order);
997 kmemcheck_free_shadow(page, order);
1000 * Check tail pages before head page information is cleared to
1001 * avoid checking PageCompound for order-0 pages.
1003 if (unlikely(order)) {
1004 bool compound = PageCompound(page);
1007 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1009 for (i = 1; i < (1 << order); i++) {
1011 bad += free_tail_pages_check(page, page + i);
1012 if (unlikely(free_pages_check(page + i))) {
1016 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1019 if (PageMappingFlags(page))
1020 page->mapping = NULL;
1022 bad += free_pages_check(page);
1026 page_cpupid_reset_last(page);
1027 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1028 reset_page_owner(page, order);
1030 if (!PageHighMem(page)) {
1031 debug_check_no_locks_freed(page_address(page),
1032 PAGE_SIZE << order);
1033 debug_check_no_obj_freed(page_address(page),
1034 PAGE_SIZE << order);
1036 arch_free_page(page, order);
1037 kernel_poison_pages(page, 1 << order, 0);
1038 kernel_map_pages(page, 1 << order, 0);
1039 kasan_free_pages(page, order);
1044 #ifdef CONFIG_DEBUG_VM
1045 static inline bool free_pcp_prepare(struct page *page)
1047 return free_pages_prepare(page, 0, true);
1050 static inline bool bulkfree_pcp_prepare(struct page *page)
1055 static bool free_pcp_prepare(struct page *page)
1057 return free_pages_prepare(page, 0, false);
1060 static bool bulkfree_pcp_prepare(struct page *page)
1062 return free_pages_check(page);
1064 #endif /* CONFIG_DEBUG_VM */
1067 * Frees a number of pages from the PCP lists
1068 * Assumes all pages on list are in same zone, and of same order.
1069 * count is the number of pages to free.
1071 * If the zone was previously in an "all pages pinned" state then look to
1072 * see if this freeing clears that state.
1074 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1075 * pinned" detection logic.
1077 static void free_pcppages_bulk(struct zone *zone, int count,
1078 struct per_cpu_pages *pcp)
1080 int migratetype = 0;
1082 unsigned long nr_scanned;
1083 bool isolated_pageblocks;
1085 spin_lock(&zone->lock);
1086 isolated_pageblocks = has_isolate_pageblock(zone);
1087 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1089 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1093 struct list_head *list;
1096 * Remove pages from lists in a round-robin fashion. A
1097 * batch_free count is maintained that is incremented when an
1098 * empty list is encountered. This is so more pages are freed
1099 * off fuller lists instead of spinning excessively around empty
1104 if (++migratetype == MIGRATE_PCPTYPES)
1106 list = &pcp->lists[migratetype];
1107 } while (list_empty(list));
1109 /* This is the only non-empty list. Free them all. */
1110 if (batch_free == MIGRATE_PCPTYPES)
1114 int mt; /* migratetype of the to-be-freed page */
1116 page = list_last_entry(list, struct page, lru);
1117 /* must delete as __free_one_page list manipulates */
1118 list_del(&page->lru);
1120 mt = get_pcppage_migratetype(page);
1121 /* MIGRATE_ISOLATE page should not go to pcplists */
1122 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1123 /* Pageblock could have been isolated meanwhile */
1124 if (unlikely(isolated_pageblocks))
1125 mt = get_pageblock_migratetype(page);
1127 if (bulkfree_pcp_prepare(page))
1130 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1131 trace_mm_page_pcpu_drain(page, 0, mt);
1132 } while (--count && --batch_free && !list_empty(list));
1134 spin_unlock(&zone->lock);
1137 static void free_one_page(struct zone *zone,
1138 struct page *page, unsigned long pfn,
1142 unsigned long nr_scanned;
1143 spin_lock(&zone->lock);
1144 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1146 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1148 if (unlikely(has_isolate_pageblock(zone) ||
1149 is_migrate_isolate(migratetype))) {
1150 migratetype = get_pfnblock_migratetype(page, pfn);
1152 __free_one_page(page, pfn, zone, order, migratetype);
1153 spin_unlock(&zone->lock);
1156 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1157 unsigned long zone, int nid)
1159 set_page_links(page, zone, nid, pfn);
1160 init_page_count(page);
1161 page_mapcount_reset(page);
1162 page_cpupid_reset_last(page);
1164 INIT_LIST_HEAD(&page->lru);
1165 #ifdef WANT_PAGE_VIRTUAL
1166 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1167 if (!is_highmem_idx(zone))
1168 set_page_address(page, __va(pfn << PAGE_SHIFT));
1172 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
1175 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
1178 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1179 static void init_reserved_page(unsigned long pfn)
1184 if (!early_page_uninitialised(pfn))
1187 nid = early_pfn_to_nid(pfn);
1188 pgdat = NODE_DATA(nid);
1190 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1191 struct zone *zone = &pgdat->node_zones[zid];
1193 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1196 __init_single_pfn(pfn, zid, nid);
1199 static inline void init_reserved_page(unsigned long pfn)
1202 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1205 * Initialised pages do not have PageReserved set. This function is
1206 * called for each range allocated by the bootmem allocator and
1207 * marks the pages PageReserved. The remaining valid pages are later
1208 * sent to the buddy page allocator.
1210 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1212 unsigned long start_pfn = PFN_DOWN(start);
1213 unsigned long end_pfn = PFN_UP(end);
1215 for (; start_pfn < end_pfn; start_pfn++) {
1216 if (pfn_valid(start_pfn)) {
1217 struct page *page = pfn_to_page(start_pfn);
1219 init_reserved_page(start_pfn);
1221 /* Avoid false-positive PageTail() */
1222 INIT_LIST_HEAD(&page->lru);
1224 SetPageReserved(page);
1229 static void __free_pages_ok(struct page *page, unsigned int order)
1231 unsigned long flags;
1233 unsigned long pfn = page_to_pfn(page);
1235 if (!free_pages_prepare(page, order, true))
1238 migratetype = get_pfnblock_migratetype(page, pfn);
1239 local_irq_save(flags);
1240 __count_vm_events(PGFREE, 1 << order);
1241 free_one_page(page_zone(page), page, pfn, order, migratetype);
1242 local_irq_restore(flags);
1245 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1247 unsigned int nr_pages = 1 << order;
1248 struct page *p = page;
1252 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1254 __ClearPageReserved(p);
1255 set_page_count(p, 0);
1257 __ClearPageReserved(p);
1258 set_page_count(p, 0);
1260 page_zone(page)->managed_pages += nr_pages;
1261 set_page_refcounted(page);
1262 __free_pages(page, order);
1265 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1266 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1268 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1270 int __meminit early_pfn_to_nid(unsigned long pfn)
1272 static DEFINE_SPINLOCK(early_pfn_lock);
1275 spin_lock(&early_pfn_lock);
1276 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1278 nid = first_online_node;
1279 spin_unlock(&early_pfn_lock);
1285 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1286 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1287 struct mminit_pfnnid_cache *state)
1291 nid = __early_pfn_to_nid(pfn, state);
1292 if (nid >= 0 && nid != node)
1297 /* Only safe to use early in boot when initialisation is single-threaded */
1298 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1300 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1305 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1309 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1310 struct mminit_pfnnid_cache *state)
1317 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1320 if (early_page_uninitialised(pfn))
1322 return __free_pages_boot_core(page, order);
1326 * Check that the whole (or subset of) a pageblock given by the interval of
1327 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1328 * with the migration of free compaction scanner. The scanners then need to
1329 * use only pfn_valid_within() check for arches that allow holes within
1332 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1334 * It's possible on some configurations to have a setup like node0 node1 node0
1335 * i.e. it's possible that all pages within a zones range of pages do not
1336 * belong to a single zone. We assume that a border between node0 and node1
1337 * can occur within a single pageblock, but not a node0 node1 node0
1338 * interleaving within a single pageblock. It is therefore sufficient to check
1339 * the first and last page of a pageblock and avoid checking each individual
1340 * page in a pageblock.
1342 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1343 unsigned long end_pfn, struct zone *zone)
1345 struct page *start_page;
1346 struct page *end_page;
1348 /* end_pfn is one past the range we are checking */
1351 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1354 start_page = pfn_to_page(start_pfn);
1356 if (page_zone(start_page) != zone)
1359 end_page = pfn_to_page(end_pfn);
1361 /* This gives a shorter code than deriving page_zone(end_page) */
1362 if (page_zone_id(start_page) != page_zone_id(end_page))
1368 void set_zone_contiguous(struct zone *zone)
1370 unsigned long block_start_pfn = zone->zone_start_pfn;
1371 unsigned long block_end_pfn;
1373 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1374 for (; block_start_pfn < zone_end_pfn(zone);
1375 block_start_pfn = block_end_pfn,
1376 block_end_pfn += pageblock_nr_pages) {
1378 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1380 if (!__pageblock_pfn_to_page(block_start_pfn,
1381 block_end_pfn, zone))
1385 /* We confirm that there is no hole */
1386 zone->contiguous = true;
1389 void clear_zone_contiguous(struct zone *zone)
1391 zone->contiguous = false;
1394 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1395 static void __init deferred_free_range(struct page *page,
1396 unsigned long pfn, int nr_pages)
1403 /* Free a large naturally-aligned chunk if possible */
1404 if (nr_pages == MAX_ORDER_NR_PAGES &&
1405 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1406 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1407 __free_pages_boot_core(page, MAX_ORDER-1);
1411 for (i = 0; i < nr_pages; i++, page++)
1412 __free_pages_boot_core(page, 0);
1415 /* Completion tracking for deferred_init_memmap() threads */
1416 static atomic_t pgdat_init_n_undone __initdata;
1417 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1419 static inline void __init pgdat_init_report_one_done(void)
1421 if (atomic_dec_and_test(&pgdat_init_n_undone))
1422 complete(&pgdat_init_all_done_comp);
1425 /* Initialise remaining memory on a node */
1426 static int __init deferred_init_memmap(void *data)
1428 pg_data_t *pgdat = data;
1429 int nid = pgdat->node_id;
1430 struct mminit_pfnnid_cache nid_init_state = { };
1431 unsigned long start = jiffies;
1432 unsigned long nr_pages = 0;
1433 unsigned long walk_start, walk_end;
1436 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1437 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1439 if (first_init_pfn == ULONG_MAX) {
1440 pgdat_init_report_one_done();
1444 /* Bind memory initialisation thread to a local node if possible */
1445 if (!cpumask_empty(cpumask))
1446 set_cpus_allowed_ptr(current, cpumask);
1448 /* Sanity check boundaries */
1449 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1450 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1451 pgdat->first_deferred_pfn = ULONG_MAX;
1453 /* Only the highest zone is deferred so find it */
1454 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1455 zone = pgdat->node_zones + zid;
1456 if (first_init_pfn < zone_end_pfn(zone))
1460 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1461 unsigned long pfn, end_pfn;
1462 struct page *page = NULL;
1463 struct page *free_base_page = NULL;
1464 unsigned long free_base_pfn = 0;
1467 end_pfn = min(walk_end, zone_end_pfn(zone));
1468 pfn = first_init_pfn;
1469 if (pfn < walk_start)
1471 if (pfn < zone->zone_start_pfn)
1472 pfn = zone->zone_start_pfn;
1474 for (; pfn < end_pfn; pfn++) {
1475 if (!pfn_valid_within(pfn))
1479 * Ensure pfn_valid is checked every
1480 * MAX_ORDER_NR_PAGES for memory holes
1482 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1483 if (!pfn_valid(pfn)) {
1489 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1494 /* Minimise pfn page lookups and scheduler checks */
1495 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1498 nr_pages += nr_to_free;
1499 deferred_free_range(free_base_page,
1500 free_base_pfn, nr_to_free);
1501 free_base_page = NULL;
1502 free_base_pfn = nr_to_free = 0;
1504 page = pfn_to_page(pfn);
1509 VM_BUG_ON(page_zone(page) != zone);
1513 __init_single_page(page, pfn, zid, nid);
1514 if (!free_base_page) {
1515 free_base_page = page;
1516 free_base_pfn = pfn;
1521 /* Where possible, batch up pages for a single free */
1524 /* Free the current block of pages to allocator */
1525 nr_pages += nr_to_free;
1526 deferred_free_range(free_base_page, free_base_pfn,
1528 free_base_page = NULL;
1529 free_base_pfn = nr_to_free = 0;
1532 first_init_pfn = max(end_pfn, first_init_pfn);
1535 /* Sanity check that the next zone really is unpopulated */
1536 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1538 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1539 jiffies_to_msecs(jiffies - start));
1541 pgdat_init_report_one_done();
1544 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1546 void __init page_alloc_init_late(void)
1550 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1553 /* There will be num_node_state(N_MEMORY) threads */
1554 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1555 for_each_node_state(nid, N_MEMORY) {
1556 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1559 /* Block until all are initialised */
1560 wait_for_completion(&pgdat_init_all_done_comp);
1562 /* Reinit limits that are based on free pages after the kernel is up */
1563 files_maxfiles_init();
1566 for_each_populated_zone(zone)
1567 set_zone_contiguous(zone);
1571 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1572 void __init init_cma_reserved_pageblock(struct page *page)
1574 unsigned i = pageblock_nr_pages;
1575 struct page *p = page;
1578 __ClearPageReserved(p);
1579 set_page_count(p, 0);
1582 set_pageblock_migratetype(page, MIGRATE_CMA);
1584 if (pageblock_order >= MAX_ORDER) {
1585 i = pageblock_nr_pages;
1588 set_page_refcounted(p);
1589 __free_pages(p, MAX_ORDER - 1);
1590 p += MAX_ORDER_NR_PAGES;
1591 } while (i -= MAX_ORDER_NR_PAGES);
1593 set_page_refcounted(page);
1594 __free_pages(page, pageblock_order);
1597 adjust_managed_page_count(page, pageblock_nr_pages);
1602 * The order of subdivision here is critical for the IO subsystem.
1603 * Please do not alter this order without good reasons and regression
1604 * testing. Specifically, as large blocks of memory are subdivided,
1605 * the order in which smaller blocks are delivered depends on the order
1606 * they're subdivided in this function. This is the primary factor
1607 * influencing the order in which pages are delivered to the IO
1608 * subsystem according to empirical testing, and this is also justified
1609 * by considering the behavior of a buddy system containing a single
1610 * large block of memory acted on by a series of small allocations.
1611 * This behavior is a critical factor in sglist merging's success.
1615 static inline void expand(struct zone *zone, struct page *page,
1616 int low, int high, struct free_area *area,
1619 unsigned long size = 1 << high;
1621 while (high > low) {
1625 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1627 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1628 debug_guardpage_enabled() &&
1629 high < debug_guardpage_minorder()) {
1631 * Mark as guard pages (or page), that will allow to
1632 * merge back to allocator when buddy will be freed.
1633 * Corresponding page table entries will not be touched,
1634 * pages will stay not present in virtual address space
1636 set_page_guard(zone, &page[size], high, migratetype);
1639 list_add(&page[size].lru, &area->free_list[migratetype]);
1641 set_page_order(&page[size], high);
1645 static void check_new_page_bad(struct page *page)
1647 const char *bad_reason = NULL;
1648 unsigned long bad_flags = 0;
1650 if (unlikely(atomic_read(&page->_mapcount) != -1))
1651 bad_reason = "nonzero mapcount";
1652 if (unlikely(page->mapping != NULL))
1653 bad_reason = "non-NULL mapping";
1654 if (unlikely(page_ref_count(page) != 0))
1655 bad_reason = "nonzero _count";
1656 if (unlikely(page->flags & __PG_HWPOISON)) {
1657 bad_reason = "HWPoisoned (hardware-corrupted)";
1658 bad_flags = __PG_HWPOISON;
1659 /* Don't complain about hwpoisoned pages */
1660 page_mapcount_reset(page); /* remove PageBuddy */
1663 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1664 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1665 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1668 if (unlikely(page->mem_cgroup))
1669 bad_reason = "page still charged to cgroup";
1671 bad_page(page, bad_reason, bad_flags);
1675 * This page is about to be returned from the page allocator
1677 static inline int check_new_page(struct page *page)
1679 if (likely(page_expected_state(page,
1680 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
1683 check_new_page_bad(page);
1687 static inline bool free_pages_prezeroed(bool poisoned)
1689 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1690 page_poisoning_enabled() && poisoned;
1693 #ifdef CONFIG_DEBUG_VM
1694 static bool check_pcp_refill(struct page *page)
1699 static bool check_new_pcp(struct page *page)
1701 return check_new_page(page);
1704 static bool check_pcp_refill(struct page *page)
1706 return check_new_page(page);
1708 static bool check_new_pcp(struct page *page)
1712 #endif /* CONFIG_DEBUG_VM */
1714 static bool check_new_pages(struct page *page, unsigned int order)
1717 for (i = 0; i < (1 << order); i++) {
1718 struct page *p = page + i;
1720 if (unlikely(check_new_page(p)))
1727 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1728 unsigned int alloc_flags)
1731 bool poisoned = true;
1733 for (i = 0; i < (1 << order); i++) {
1734 struct page *p = page + i;
1736 poisoned &= page_is_poisoned(p);
1739 set_page_private(page, 0);
1740 set_page_refcounted(page);
1742 arch_alloc_page(page, order);
1743 kernel_map_pages(page, 1 << order, 1);
1744 kernel_poison_pages(page, 1 << order, 1);
1745 kasan_alloc_pages(page, order);
1747 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1748 for (i = 0; i < (1 << order); i++)
1749 clear_highpage(page + i);
1751 if (order && (gfp_flags & __GFP_COMP))
1752 prep_compound_page(page, order);
1754 set_page_owner(page, order, gfp_flags);
1757 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1758 * allocate the page. The expectation is that the caller is taking
1759 * steps that will free more memory. The caller should avoid the page
1760 * being used for !PFMEMALLOC purposes.
1762 if (alloc_flags & ALLOC_NO_WATERMARKS)
1763 set_page_pfmemalloc(page);
1765 clear_page_pfmemalloc(page);
1769 * Go through the free lists for the given migratetype and remove
1770 * the smallest available page from the freelists
1773 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1776 unsigned int current_order;
1777 struct free_area *area;
1780 /* Find a page of the appropriate size in the preferred list */
1781 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1782 area = &(zone->free_area[current_order]);
1783 page = list_first_entry_or_null(&area->free_list[migratetype],
1787 list_del(&page->lru);
1788 rmv_page_order(page);
1790 expand(zone, page, order, current_order, area, migratetype);
1791 set_pcppage_migratetype(page, migratetype);
1800 * This array describes the order lists are fallen back to when
1801 * the free lists for the desirable migrate type are depleted
1803 static int fallbacks[MIGRATE_TYPES][4] = {
1804 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1805 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1806 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1808 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1810 #ifdef CONFIG_MEMORY_ISOLATION
1811 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1816 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1819 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1822 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1823 unsigned int order) { return NULL; }
1827 * Move the free pages in a range to the free lists of the requested type.
1828 * Note that start_page and end_pages are not aligned on a pageblock
1829 * boundary. If alignment is required, use move_freepages_block()
1831 int move_freepages(struct zone *zone,
1832 struct page *start_page, struct page *end_page,
1837 int pages_moved = 0;
1839 #ifndef CONFIG_HOLES_IN_ZONE
1841 * page_zone is not safe to call in this context when
1842 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1843 * anyway as we check zone boundaries in move_freepages_block().
1844 * Remove at a later date when no bug reports exist related to
1845 * grouping pages by mobility
1847 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1850 for (page = start_page; page <= end_page;) {
1851 /* Make sure we are not inadvertently changing nodes */
1852 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1854 if (!pfn_valid_within(page_to_pfn(page))) {
1859 if (!PageBuddy(page)) {
1864 order = page_order(page);
1865 list_move(&page->lru,
1866 &zone->free_area[order].free_list[migratetype]);
1868 pages_moved += 1 << order;
1874 int move_freepages_block(struct zone *zone, struct page *page,
1877 unsigned long start_pfn, end_pfn;
1878 struct page *start_page, *end_page;
1880 start_pfn = page_to_pfn(page);
1881 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1882 start_page = pfn_to_page(start_pfn);
1883 end_page = start_page + pageblock_nr_pages - 1;
1884 end_pfn = start_pfn + pageblock_nr_pages - 1;
1886 /* Do not cross zone boundaries */
1887 if (!zone_spans_pfn(zone, start_pfn))
1889 if (!zone_spans_pfn(zone, end_pfn))
1892 return move_freepages(zone, start_page, end_page, migratetype);
1895 static void change_pageblock_range(struct page *pageblock_page,
1896 int start_order, int migratetype)
1898 int nr_pageblocks = 1 << (start_order - pageblock_order);
1900 while (nr_pageblocks--) {
1901 set_pageblock_migratetype(pageblock_page, migratetype);
1902 pageblock_page += pageblock_nr_pages;
1907 * When we are falling back to another migratetype during allocation, try to
1908 * steal extra free pages from the same pageblocks to satisfy further
1909 * allocations, instead of polluting multiple pageblocks.
1911 * If we are stealing a relatively large buddy page, it is likely there will
1912 * be more free pages in the pageblock, so try to steal them all. For
1913 * reclaimable and unmovable allocations, we steal regardless of page size,
1914 * as fragmentation caused by those allocations polluting movable pageblocks
1915 * is worse than movable allocations stealing from unmovable and reclaimable
1918 static bool can_steal_fallback(unsigned int order, int start_mt)
1921 * Leaving this order check is intended, although there is
1922 * relaxed order check in next check. The reason is that
1923 * we can actually steal whole pageblock if this condition met,
1924 * but, below check doesn't guarantee it and that is just heuristic
1925 * so could be changed anytime.
1927 if (order >= pageblock_order)
1930 if (order >= pageblock_order / 2 ||
1931 start_mt == MIGRATE_RECLAIMABLE ||
1932 start_mt == MIGRATE_UNMOVABLE ||
1933 page_group_by_mobility_disabled)
1940 * This function implements actual steal behaviour. If order is large enough,
1941 * we can steal whole pageblock. If not, we first move freepages in this
1942 * pageblock and check whether half of pages are moved or not. If half of
1943 * pages are moved, we can change migratetype of pageblock and permanently
1944 * use it's pages as requested migratetype in the future.
1946 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1949 unsigned int current_order = page_order(page);
1952 /* Take ownership for orders >= pageblock_order */
1953 if (current_order >= pageblock_order) {
1954 change_pageblock_range(page, current_order, start_type);
1958 pages = move_freepages_block(zone, page, start_type);
1960 /* Claim the whole block if over half of it is free */
1961 if (pages >= (1 << (pageblock_order-1)) ||
1962 page_group_by_mobility_disabled)
1963 set_pageblock_migratetype(page, start_type);
1967 * Check whether there is a suitable fallback freepage with requested order.
1968 * If only_stealable is true, this function returns fallback_mt only if
1969 * we can steal other freepages all together. This would help to reduce
1970 * fragmentation due to mixed migratetype pages in one pageblock.
1972 int find_suitable_fallback(struct free_area *area, unsigned int order,
1973 int migratetype, bool only_stealable, bool *can_steal)
1978 if (area->nr_free == 0)
1983 fallback_mt = fallbacks[migratetype][i];
1984 if (fallback_mt == MIGRATE_TYPES)
1987 if (list_empty(&area->free_list[fallback_mt]))
1990 if (can_steal_fallback(order, migratetype))
1993 if (!only_stealable)
2004 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2005 * there are no empty page blocks that contain a page with a suitable order
2007 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2008 unsigned int alloc_order)
2011 unsigned long max_managed, flags;
2014 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2015 * Check is race-prone but harmless.
2017 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2018 if (zone->nr_reserved_highatomic >= max_managed)
2021 spin_lock_irqsave(&zone->lock, flags);
2023 /* Recheck the nr_reserved_highatomic limit under the lock */
2024 if (zone->nr_reserved_highatomic >= max_managed)
2028 mt = get_pageblock_migratetype(page);
2029 if (mt != MIGRATE_HIGHATOMIC &&
2030 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
2031 zone->nr_reserved_highatomic += pageblock_nr_pages;
2032 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2033 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
2037 spin_unlock_irqrestore(&zone->lock, flags);
2041 * Used when an allocation is about to fail under memory pressure. This
2042 * potentially hurts the reliability of high-order allocations when under
2043 * intense memory pressure but failed atomic allocations should be easier
2044 * to recover from than an OOM.
2046 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
2048 struct zonelist *zonelist = ac->zonelist;
2049 unsigned long flags;
2055 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2057 /* Preserve at least one pageblock */
2058 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
2061 spin_lock_irqsave(&zone->lock, flags);
2062 for (order = 0; order < MAX_ORDER; order++) {
2063 struct free_area *area = &(zone->free_area[order]);
2065 page = list_first_entry_or_null(
2066 &area->free_list[MIGRATE_HIGHATOMIC],
2072 * It should never happen but changes to locking could
2073 * inadvertently allow a per-cpu drain to add pages
2074 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2075 * and watch for underflows.
2077 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
2078 zone->nr_reserved_highatomic);
2081 * Convert to ac->migratetype and avoid the normal
2082 * pageblock stealing heuristics. Minimally, the caller
2083 * is doing the work and needs the pages. More
2084 * importantly, if the block was always converted to
2085 * MIGRATE_UNMOVABLE or another type then the number
2086 * of pageblocks that cannot be completely freed
2089 set_pageblock_migratetype(page, ac->migratetype);
2090 move_freepages_block(zone, page, ac->migratetype);
2091 spin_unlock_irqrestore(&zone->lock, flags);
2094 spin_unlock_irqrestore(&zone->lock, flags);
2098 /* Remove an element from the buddy allocator from the fallback list */
2099 static inline struct page *
2100 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
2102 struct free_area *area;
2103 unsigned int current_order;
2108 /* Find the largest possible block of pages in the other list */
2109 for (current_order = MAX_ORDER-1;
2110 current_order >= order && current_order <= MAX_ORDER-1;
2112 area = &(zone->free_area[current_order]);
2113 fallback_mt = find_suitable_fallback(area, current_order,
2114 start_migratetype, false, &can_steal);
2115 if (fallback_mt == -1)
2118 page = list_first_entry(&area->free_list[fallback_mt],
2121 steal_suitable_fallback(zone, page, start_migratetype);
2123 /* Remove the page from the freelists */
2125 list_del(&page->lru);
2126 rmv_page_order(page);
2128 expand(zone, page, order, current_order, area,
2131 * The pcppage_migratetype may differ from pageblock's
2132 * migratetype depending on the decisions in
2133 * find_suitable_fallback(). This is OK as long as it does not
2134 * differ for MIGRATE_CMA pageblocks. Those can be used as
2135 * fallback only via special __rmqueue_cma_fallback() function
2137 set_pcppage_migratetype(page, start_migratetype);
2139 trace_mm_page_alloc_extfrag(page, order, current_order,
2140 start_migratetype, fallback_mt);
2149 * Do the hard work of removing an element from the buddy allocator.
2150 * Call me with the zone->lock already held.
2152 static struct page *__rmqueue(struct zone *zone, unsigned int order,
2157 page = __rmqueue_smallest(zone, order, migratetype);
2158 if (unlikely(!page)) {
2159 if (migratetype == MIGRATE_MOVABLE)
2160 page = __rmqueue_cma_fallback(zone, order);
2163 page = __rmqueue_fallback(zone, order, migratetype);
2166 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2171 * Obtain a specified number of elements from the buddy allocator, all under
2172 * a single hold of the lock, for efficiency. Add them to the supplied list.
2173 * Returns the number of new pages which were placed at *list.
2175 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2176 unsigned long count, struct list_head *list,
2177 int migratetype, bool cold)
2181 spin_lock(&zone->lock);
2182 for (i = 0; i < count; ++i) {
2183 struct page *page = __rmqueue(zone, order, migratetype);
2184 if (unlikely(page == NULL))
2187 if (unlikely(check_pcp_refill(page)))
2191 * Split buddy pages returned by expand() are received here
2192 * in physical page order. The page is added to the callers and
2193 * list and the list head then moves forward. From the callers
2194 * perspective, the linked list is ordered by page number in
2195 * some conditions. This is useful for IO devices that can
2196 * merge IO requests if the physical pages are ordered
2200 list_add(&page->lru, list);
2202 list_add_tail(&page->lru, list);
2204 if (is_migrate_cma(get_pcppage_migratetype(page)))
2205 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2208 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2209 spin_unlock(&zone->lock);
2215 * Called from the vmstat counter updater to drain pagesets of this
2216 * currently executing processor on remote nodes after they have
2219 * Note that this function must be called with the thread pinned to
2220 * a single processor.
2222 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2224 unsigned long flags;
2225 int to_drain, batch;
2227 local_irq_save(flags);
2228 batch = READ_ONCE(pcp->batch);
2229 to_drain = min(pcp->count, batch);
2231 free_pcppages_bulk(zone, to_drain, pcp);
2232 pcp->count -= to_drain;
2234 local_irq_restore(flags);
2239 * Drain pcplists of the indicated processor and zone.
2241 * The processor must either be the current processor and the
2242 * thread pinned to the current processor or a processor that
2245 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2247 unsigned long flags;
2248 struct per_cpu_pageset *pset;
2249 struct per_cpu_pages *pcp;
2251 local_irq_save(flags);
2252 pset = per_cpu_ptr(zone->pageset, cpu);
2256 free_pcppages_bulk(zone, pcp->count, pcp);
2259 local_irq_restore(flags);
2263 * Drain pcplists of all zones on the indicated processor.
2265 * The processor must either be the current processor and the
2266 * thread pinned to the current processor or a processor that
2269 static void drain_pages(unsigned int cpu)
2273 for_each_populated_zone(zone) {
2274 drain_pages_zone(cpu, zone);
2279 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2281 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2282 * the single zone's pages.
2284 void drain_local_pages(struct zone *zone)
2286 int cpu = smp_processor_id();
2289 drain_pages_zone(cpu, zone);
2295 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2297 * When zone parameter is non-NULL, spill just the single zone's pages.
2299 * Note that this code is protected against sending an IPI to an offline
2300 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2301 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2302 * nothing keeps CPUs from showing up after we populated the cpumask and
2303 * before the call to on_each_cpu_mask().
2305 void drain_all_pages(struct zone *zone)
2310 * Allocate in the BSS so we wont require allocation in
2311 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2313 static cpumask_t cpus_with_pcps;
2316 * We don't care about racing with CPU hotplug event
2317 * as offline notification will cause the notified
2318 * cpu to drain that CPU pcps and on_each_cpu_mask
2319 * disables preemption as part of its processing
2321 for_each_online_cpu(cpu) {
2322 struct per_cpu_pageset *pcp;
2324 bool has_pcps = false;
2327 pcp = per_cpu_ptr(zone->pageset, cpu);
2331 for_each_populated_zone(z) {
2332 pcp = per_cpu_ptr(z->pageset, cpu);
2333 if (pcp->pcp.count) {
2341 cpumask_set_cpu(cpu, &cpus_with_pcps);
2343 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2345 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2349 #ifdef CONFIG_HIBERNATION
2351 void mark_free_pages(struct zone *zone)
2353 unsigned long pfn, max_zone_pfn;
2354 unsigned long flags;
2355 unsigned int order, t;
2358 if (zone_is_empty(zone))
2361 spin_lock_irqsave(&zone->lock, flags);
2363 max_zone_pfn = zone_end_pfn(zone);
2364 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2365 if (pfn_valid(pfn)) {
2366 page = pfn_to_page(pfn);
2368 if (page_zone(page) != zone)
2371 if (!swsusp_page_is_forbidden(page))
2372 swsusp_unset_page_free(page);
2375 for_each_migratetype_order(order, t) {
2376 list_for_each_entry(page,
2377 &zone->free_area[order].free_list[t], lru) {
2380 pfn = page_to_pfn(page);
2381 for (i = 0; i < (1UL << order); i++)
2382 swsusp_set_page_free(pfn_to_page(pfn + i));
2385 spin_unlock_irqrestore(&zone->lock, flags);
2387 #endif /* CONFIG_PM */
2390 * Free a 0-order page
2391 * cold == true ? free a cold page : free a hot page
2393 void free_hot_cold_page(struct page *page, bool cold)
2395 struct zone *zone = page_zone(page);
2396 struct per_cpu_pages *pcp;
2397 unsigned long flags;
2398 unsigned long pfn = page_to_pfn(page);
2401 if (!free_pcp_prepare(page))
2404 migratetype = get_pfnblock_migratetype(page, pfn);
2405 set_pcppage_migratetype(page, migratetype);
2406 local_irq_save(flags);
2407 __count_vm_event(PGFREE);
2410 * We only track unmovable, reclaimable and movable on pcp lists.
2411 * Free ISOLATE pages back to the allocator because they are being
2412 * offlined but treat RESERVE as movable pages so we can get those
2413 * areas back if necessary. Otherwise, we may have to free
2414 * excessively into the page allocator
2416 if (migratetype >= MIGRATE_PCPTYPES) {
2417 if (unlikely(is_migrate_isolate(migratetype))) {
2418 free_one_page(zone, page, pfn, 0, migratetype);
2421 migratetype = MIGRATE_MOVABLE;
2424 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2426 list_add(&page->lru, &pcp->lists[migratetype]);
2428 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2430 if (pcp->count >= pcp->high) {
2431 unsigned long batch = READ_ONCE(pcp->batch);
2432 free_pcppages_bulk(zone, batch, pcp);
2433 pcp->count -= batch;
2437 local_irq_restore(flags);
2441 * Free a list of 0-order pages
2443 void free_hot_cold_page_list(struct list_head *list, bool cold)
2445 struct page *page, *next;
2447 list_for_each_entry_safe(page, next, list, lru) {
2448 trace_mm_page_free_batched(page, cold);
2449 free_hot_cold_page(page, cold);
2454 * split_page takes a non-compound higher-order page, and splits it into
2455 * n (1<<order) sub-pages: page[0..n]
2456 * Each sub-page must be freed individually.
2458 * Note: this is probably too low level an operation for use in drivers.
2459 * Please consult with lkml before using this in your driver.
2461 void split_page(struct page *page, unsigned int order)
2466 VM_BUG_ON_PAGE(PageCompound(page), page);
2467 VM_BUG_ON_PAGE(!page_count(page), page);
2469 #ifdef CONFIG_KMEMCHECK
2471 * Split shadow pages too, because free(page[0]) would
2472 * otherwise free the whole shadow.
2474 if (kmemcheck_page_is_tracked(page))
2475 split_page(virt_to_page(page[0].shadow), order);
2478 gfp_mask = get_page_owner_gfp(page);
2479 set_page_owner(page, 0, gfp_mask);
2480 for (i = 1; i < (1 << order); i++) {
2481 set_page_refcounted(page + i);
2482 set_page_owner(page + i, 0, gfp_mask);
2485 EXPORT_SYMBOL_GPL(split_page);
2487 int __isolate_free_page(struct page *page, unsigned int order)
2489 unsigned long watermark;
2493 BUG_ON(!PageBuddy(page));
2495 zone = page_zone(page);
2496 mt = get_pageblock_migratetype(page);
2498 if (!is_migrate_isolate(mt)) {
2499 /* Obey watermarks as if the page was being allocated */
2500 watermark = low_wmark_pages(zone) + (1 << order);
2501 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2504 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2507 /* Remove page from free list */
2508 list_del(&page->lru);
2509 zone->free_area[order].nr_free--;
2510 rmv_page_order(page);
2512 set_page_owner(page, order, __GFP_MOVABLE);
2514 /* Set the pageblock if the isolated page is at least a pageblock */
2515 if (order >= pageblock_order - 1) {
2516 struct page *endpage = page + (1 << order) - 1;
2517 for (; page < endpage; page += pageblock_nr_pages) {
2518 int mt = get_pageblock_migratetype(page);
2519 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2520 set_pageblock_migratetype(page,
2526 return 1UL << order;
2530 * Similar to split_page except the page is already free. As this is only
2531 * being used for migration, the migratetype of the block also changes.
2532 * As this is called with interrupts disabled, the caller is responsible
2533 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2536 * Note: this is probably too low level an operation for use in drivers.
2537 * Please consult with lkml before using this in your driver.
2539 int split_free_page(struct page *page)
2544 order = page_order(page);
2546 nr_pages = __isolate_free_page(page, order);
2550 /* Split into individual pages */
2551 set_page_refcounted(page);
2552 split_page(page, order);
2557 * Update NUMA hit/miss statistics
2559 * Must be called with interrupts disabled.
2561 * When __GFP_OTHER_NODE is set assume the node of the preferred
2562 * zone is the local node. This is useful for daemons who allocate
2563 * memory on behalf of other processes.
2565 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2569 int local_nid = numa_node_id();
2570 enum zone_stat_item local_stat = NUMA_LOCAL;
2572 if (unlikely(flags & __GFP_OTHER_NODE)) {
2573 local_stat = NUMA_OTHER;
2574 local_nid = preferred_zone->node;
2577 if (z->node == local_nid) {
2578 __inc_zone_state(z, NUMA_HIT);
2579 __inc_zone_state(z, local_stat);
2581 __inc_zone_state(z, NUMA_MISS);
2582 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2588 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2591 struct page *buffered_rmqueue(struct zone *preferred_zone,
2592 struct zone *zone, unsigned int order,
2593 gfp_t gfp_flags, unsigned int alloc_flags,
2596 unsigned long flags;
2598 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2600 if (likely(order == 0)) {
2601 struct per_cpu_pages *pcp;
2602 struct list_head *list;
2604 local_irq_save(flags);
2606 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2607 list = &pcp->lists[migratetype];
2608 if (list_empty(list)) {
2609 pcp->count += rmqueue_bulk(zone, 0,
2612 if (unlikely(list_empty(list)))
2617 page = list_last_entry(list, struct page, lru);
2619 page = list_first_entry(list, struct page, lru);
2621 __dec_zone_state(zone, NR_ALLOC_BATCH);
2622 list_del(&page->lru);
2625 } while (check_new_pcp(page));
2628 * We most definitely don't want callers attempting to
2629 * allocate greater than order-1 page units with __GFP_NOFAIL.
2631 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2632 spin_lock_irqsave(&zone->lock, flags);
2636 if (alloc_flags & ALLOC_HARDER) {
2637 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2639 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2642 page = __rmqueue(zone, order, migratetype);
2643 } while (page && check_new_pages(page, order));
2644 spin_unlock(&zone->lock);
2647 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2648 __mod_zone_freepage_state(zone, -(1 << order),
2649 get_pcppage_migratetype(page));
2652 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2653 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2654 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2656 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2657 zone_statistics(preferred_zone, zone, gfp_flags);
2658 local_irq_restore(flags);
2660 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2664 local_irq_restore(flags);
2668 #ifdef CONFIG_FAIL_PAGE_ALLOC
2671 struct fault_attr attr;
2673 bool ignore_gfp_highmem;
2674 bool ignore_gfp_reclaim;
2676 } fail_page_alloc = {
2677 .attr = FAULT_ATTR_INITIALIZER,
2678 .ignore_gfp_reclaim = true,
2679 .ignore_gfp_highmem = true,
2683 static int __init setup_fail_page_alloc(char *str)
2685 return setup_fault_attr(&fail_page_alloc.attr, str);
2687 __setup("fail_page_alloc=", setup_fail_page_alloc);
2689 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2691 if (order < fail_page_alloc.min_order)
2693 if (gfp_mask & __GFP_NOFAIL)
2695 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2697 if (fail_page_alloc.ignore_gfp_reclaim &&
2698 (gfp_mask & __GFP_DIRECT_RECLAIM))
2701 return should_fail(&fail_page_alloc.attr, 1 << order);
2704 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2706 static int __init fail_page_alloc_debugfs(void)
2708 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2711 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2712 &fail_page_alloc.attr);
2714 return PTR_ERR(dir);
2716 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2717 &fail_page_alloc.ignore_gfp_reclaim))
2719 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2720 &fail_page_alloc.ignore_gfp_highmem))
2722 if (!debugfs_create_u32("min-order", mode, dir,
2723 &fail_page_alloc.min_order))
2728 debugfs_remove_recursive(dir);
2733 late_initcall(fail_page_alloc_debugfs);
2735 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2737 #else /* CONFIG_FAIL_PAGE_ALLOC */
2739 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2744 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2747 * Return true if free base pages are above 'mark'. For high-order checks it
2748 * will return true of the order-0 watermark is reached and there is at least
2749 * one free page of a suitable size. Checking now avoids taking the zone lock
2750 * to check in the allocation paths if no pages are free.
2752 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2753 int classzone_idx, unsigned int alloc_flags,
2758 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2760 /* free_pages may go negative - that's OK */
2761 free_pages -= (1 << order) - 1;
2763 if (alloc_flags & ALLOC_HIGH)
2767 * If the caller does not have rights to ALLOC_HARDER then subtract
2768 * the high-atomic reserves. This will over-estimate the size of the
2769 * atomic reserve but it avoids a search.
2771 if (likely(!alloc_harder))
2772 free_pages -= z->nr_reserved_highatomic;
2777 /* If allocation can't use CMA areas don't use free CMA pages */
2778 if (!(alloc_flags & ALLOC_CMA))
2779 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2783 * Check watermarks for an order-0 allocation request. If these
2784 * are not met, then a high-order request also cannot go ahead
2785 * even if a suitable page happened to be free.
2787 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2790 /* If this is an order-0 request then the watermark is fine */
2794 /* For a high-order request, check at least one suitable page is free */
2795 for (o = order; o < MAX_ORDER; o++) {
2796 struct free_area *area = &z->free_area[o];
2805 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2806 if (!list_empty(&area->free_list[mt]))
2811 if ((alloc_flags & ALLOC_CMA) &&
2812 !list_empty(&area->free_list[MIGRATE_CMA])) {
2820 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2821 int classzone_idx, unsigned int alloc_flags)
2823 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2824 zone_page_state(z, NR_FREE_PAGES));
2827 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2828 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2830 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2834 /* If allocation can't use CMA areas don't use free CMA pages */
2835 if (!(alloc_flags & ALLOC_CMA))
2836 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2840 * Fast check for order-0 only. If this fails then the reserves
2841 * need to be calculated. There is a corner case where the check
2842 * passes but only the high-order atomic reserve are free. If
2843 * the caller is !atomic then it'll uselessly search the free
2844 * list. That corner case is then slower but it is harmless.
2846 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2849 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2853 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2854 unsigned long mark, int classzone_idx)
2856 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2858 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2859 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2861 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2866 static bool zone_local(struct zone *local_zone, struct zone *zone)
2868 return local_zone->node == zone->node;
2871 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2873 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2876 #else /* CONFIG_NUMA */
2877 static bool zone_local(struct zone *local_zone, struct zone *zone)
2882 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2886 #endif /* CONFIG_NUMA */
2888 static void reset_alloc_batches(struct zone *preferred_zone)
2890 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2893 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2894 high_wmark_pages(zone) - low_wmark_pages(zone) -
2895 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2896 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2897 } while (zone++ != preferred_zone);
2901 * get_page_from_freelist goes through the zonelist trying to allocate
2904 static struct page *
2905 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2906 const struct alloc_context *ac)
2908 struct zoneref *z = ac->preferred_zoneref;
2910 bool fair_skipped = false;
2911 bool apply_fair = (alloc_flags & ALLOC_FAIR);
2915 * Scan zonelist, looking for a zone with enough free.
2916 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2918 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
2923 if (cpusets_enabled() &&
2924 (alloc_flags & ALLOC_CPUSET) &&
2925 !__cpuset_zone_allowed(zone, gfp_mask))
2928 * Distribute pages in proportion to the individual
2929 * zone size to ensure fair page aging. The zone a
2930 * page was allocated in should have no effect on the
2931 * time the page has in memory before being reclaimed.
2934 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2935 fair_skipped = true;
2938 if (!zone_local(ac->preferred_zoneref->zone, zone)) {
2945 * When allocating a page cache page for writing, we
2946 * want to get it from a zone that is within its dirty
2947 * limit, such that no single zone holds more than its
2948 * proportional share of globally allowed dirty pages.
2949 * The dirty limits take into account the zone's
2950 * lowmem reserves and high watermark so that kswapd
2951 * should be able to balance it without having to
2952 * write pages from its LRU list.
2954 * This may look like it could increase pressure on
2955 * lower zones by failing allocations in higher zones
2956 * before they are full. But the pages that do spill
2957 * over are limited as the lower zones are protected
2958 * by this very same mechanism. It should not become
2959 * a practical burden to them.
2961 * XXX: For now, allow allocations to potentially
2962 * exceed the per-zone dirty limit in the slowpath
2963 * (spread_dirty_pages unset) before going into reclaim,
2964 * which is important when on a NUMA setup the allowed
2965 * zones are together not big enough to reach the
2966 * global limit. The proper fix for these situations
2967 * will require awareness of zones in the
2968 * dirty-throttling and the flusher threads.
2970 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2973 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2974 if (!zone_watermark_fast(zone, order, mark,
2975 ac_classzone_idx(ac), alloc_flags)) {
2978 /* Checked here to keep the fast path fast */
2979 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2980 if (alloc_flags & ALLOC_NO_WATERMARKS)
2983 if (zone_reclaim_mode == 0 ||
2984 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
2987 ret = zone_reclaim(zone, gfp_mask, order);
2989 case ZONE_RECLAIM_NOSCAN:
2992 case ZONE_RECLAIM_FULL:
2993 /* scanned but unreclaimable */
2996 /* did we reclaim enough */
2997 if (zone_watermark_ok(zone, order, mark,
2998 ac_classzone_idx(ac), alloc_flags))
3006 page = buffered_rmqueue(ac->preferred_zoneref->zone, zone, order,
3007 gfp_mask, alloc_flags, ac->migratetype);
3009 prep_new_page(page, order, gfp_mask, alloc_flags);
3012 * If this is a high-order atomic allocation then check
3013 * if the pageblock should be reserved for the future
3015 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3016 reserve_highatomic_pageblock(page, zone, order);
3023 * The first pass makes sure allocations are spread fairly within the
3024 * local node. However, the local node might have free pages left
3025 * after the fairness batches are exhausted, and remote zones haven't
3026 * even been considered yet. Try once more without fairness, and
3027 * include remote zones now, before entering the slowpath and waking
3028 * kswapd: prefer spilling to a remote zone over swapping locally.
3033 fair_skipped = false;
3034 reset_alloc_batches(ac->preferred_zoneref->zone);
3035 z = ac->preferred_zoneref;
3043 * Large machines with many possible nodes should not always dump per-node
3044 * meminfo in irq context.
3046 static inline bool should_suppress_show_mem(void)
3051 ret = in_interrupt();
3056 static DEFINE_RATELIMIT_STATE(nopage_rs,
3057 DEFAULT_RATELIMIT_INTERVAL,
3058 DEFAULT_RATELIMIT_BURST);
3060 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
3062 unsigned int filter = SHOW_MEM_FILTER_NODES;
3064 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
3065 debug_guardpage_minorder() > 0)
3069 * This documents exceptions given to allocations in certain
3070 * contexts that are allowed to allocate outside current's set
3073 if (!(gfp_mask & __GFP_NOMEMALLOC))
3074 if (test_thread_flag(TIF_MEMDIE) ||
3075 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3076 filter &= ~SHOW_MEM_FILTER_NODES;
3077 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3078 filter &= ~SHOW_MEM_FILTER_NODES;
3081 struct va_format vaf;
3084 va_start(args, fmt);
3089 pr_warn("%pV", &vaf);
3094 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3095 current->comm, order, gfp_mask, &gfp_mask);
3097 if (!should_suppress_show_mem())
3101 static inline struct page *
3102 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3103 const struct alloc_context *ac, unsigned long *did_some_progress)
3105 struct oom_control oc = {
3106 .zonelist = ac->zonelist,
3107 .nodemask = ac->nodemask,
3109 .gfp_mask = gfp_mask,
3114 *did_some_progress = 0;
3117 * Acquire the oom lock. If that fails, somebody else is
3118 * making progress for us.
3120 if (!mutex_trylock(&oom_lock)) {
3121 *did_some_progress = 1;
3122 schedule_timeout_uninterruptible(1);
3127 * Go through the zonelist yet one more time, keep very high watermark
3128 * here, this is only to catch a parallel oom killing, we must fail if
3129 * we're still under heavy pressure.
3131 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3132 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3136 if (!(gfp_mask & __GFP_NOFAIL)) {
3137 /* Coredumps can quickly deplete all memory reserves */
3138 if (current->flags & PF_DUMPCORE)
3140 /* The OOM killer will not help higher order allocs */
3141 if (order > PAGE_ALLOC_COSTLY_ORDER)
3143 /* The OOM killer does not needlessly kill tasks for lowmem */
3144 if (ac->high_zoneidx < ZONE_NORMAL)
3146 if (pm_suspended_storage())
3149 * XXX: GFP_NOFS allocations should rather fail than rely on
3150 * other request to make a forward progress.
3151 * We are in an unfortunate situation where out_of_memory cannot
3152 * do much for this context but let's try it to at least get
3153 * access to memory reserved if the current task is killed (see
3154 * out_of_memory). Once filesystems are ready to handle allocation
3155 * failures more gracefully we should just bail out here.
3158 /* The OOM killer may not free memory on a specific node */
3159 if (gfp_mask & __GFP_THISNODE)
3162 /* Exhausted what can be done so it's blamo time */
3163 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3164 *did_some_progress = 1;
3166 if (gfp_mask & __GFP_NOFAIL) {
3167 page = get_page_from_freelist(gfp_mask, order,
3168 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
3170 * fallback to ignore cpuset restriction if our nodes
3174 page = get_page_from_freelist(gfp_mask, order,
3175 ALLOC_NO_WATERMARKS, ac);
3179 mutex_unlock(&oom_lock);
3185 * Maximum number of compaction retries wit a progress before OOM
3186 * killer is consider as the only way to move forward.
3188 #define MAX_COMPACT_RETRIES 16
3190 #ifdef CONFIG_COMPACTION
3191 /* Try memory compaction for high-order allocations before reclaim */
3192 static struct page *
3193 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3194 unsigned int alloc_flags, const struct alloc_context *ac,
3195 enum migrate_mode mode, enum compact_result *compact_result)
3198 int contended_compaction;
3203 current->flags |= PF_MEMALLOC;
3204 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3205 mode, &contended_compaction);
3206 current->flags &= ~PF_MEMALLOC;
3208 if (*compact_result <= COMPACT_INACTIVE)
3212 * At least in one zone compaction wasn't deferred or skipped, so let's
3213 * count a compaction stall
3215 count_vm_event(COMPACTSTALL);
3217 page = get_page_from_freelist(gfp_mask, order,
3218 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3221 struct zone *zone = page_zone(page);
3223 zone->compact_blockskip_flush = false;
3224 compaction_defer_reset(zone, order, true);
3225 count_vm_event(COMPACTSUCCESS);
3230 * It's bad if compaction run occurs and fails. The most likely reason
3231 * is that pages exist, but not enough to satisfy watermarks.
3233 count_vm_event(COMPACTFAIL);
3236 * In all zones where compaction was attempted (and not
3237 * deferred or skipped), lock contention has been detected.
3238 * For THP allocation we do not want to disrupt the others
3239 * so we fallback to base pages instead.
3241 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3242 *compact_result = COMPACT_CONTENDED;
3245 * If compaction was aborted due to need_resched(), we do not
3246 * want to further increase allocation latency, unless it is
3247 * khugepaged trying to collapse.
3249 if (contended_compaction == COMPACT_CONTENDED_SCHED
3250 && !(current->flags & PF_KTHREAD))
3251 *compact_result = COMPACT_CONTENDED;
3259 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3260 enum compact_result compact_result, enum migrate_mode *migrate_mode,
3261 int compaction_retries)
3263 int max_retries = MAX_COMPACT_RETRIES;
3269 * compaction considers all the zone as desperately out of memory
3270 * so it doesn't really make much sense to retry except when the
3271 * failure could be caused by weak migration mode.
3273 if (compaction_failed(compact_result)) {
3274 if (*migrate_mode == MIGRATE_ASYNC) {
3275 *migrate_mode = MIGRATE_SYNC_LIGHT;
3282 * make sure the compaction wasn't deferred or didn't bail out early
3283 * due to locks contention before we declare that we should give up.
3284 * But do not retry if the given zonelist is not suitable for
3287 if (compaction_withdrawn(compact_result))
3288 return compaction_zonelist_suitable(ac, order, alloc_flags);
3291 * !costly requests are much more important than __GFP_REPEAT
3292 * costly ones because they are de facto nofail and invoke OOM
3293 * killer to move on while costly can fail and users are ready
3294 * to cope with that. 1/4 retries is rather arbitrary but we
3295 * would need much more detailed feedback from compaction to
3296 * make a better decision.
3298 if (order > PAGE_ALLOC_COSTLY_ORDER)
3300 if (compaction_retries <= max_retries)
3306 static inline struct page *
3307 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3308 unsigned int alloc_flags, const struct alloc_context *ac,
3309 enum migrate_mode mode, enum compact_result *compact_result)
3311 *compact_result = COMPACT_SKIPPED;
3316 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3317 enum compact_result compact_result,
3318 enum migrate_mode *migrate_mode,
3319 int compaction_retries)
3324 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
3328 * There are setups with compaction disabled which would prefer to loop
3329 * inside the allocator rather than hit the oom killer prematurely.
3330 * Let's give them a good hope and keep retrying while the order-0
3331 * watermarks are OK.
3333 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3335 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
3336 ac_classzone_idx(ac), alloc_flags))
3341 #endif /* CONFIG_COMPACTION */
3343 /* Perform direct synchronous page reclaim */
3345 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3346 const struct alloc_context *ac)
3348 struct reclaim_state reclaim_state;
3353 /* We now go into synchronous reclaim */
3354 cpuset_memory_pressure_bump();
3355 current->flags |= PF_MEMALLOC;
3356 lockdep_set_current_reclaim_state(gfp_mask);
3357 reclaim_state.reclaimed_slab = 0;
3358 current->reclaim_state = &reclaim_state;
3360 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3363 current->reclaim_state = NULL;
3364 lockdep_clear_current_reclaim_state();
3365 current->flags &= ~PF_MEMALLOC;
3372 /* The really slow allocator path where we enter direct reclaim */
3373 static inline struct page *
3374 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3375 unsigned int alloc_flags, const struct alloc_context *ac,
3376 unsigned long *did_some_progress)
3378 struct page *page = NULL;
3379 bool drained = false;
3381 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3382 if (unlikely(!(*did_some_progress)))
3386 page = get_page_from_freelist(gfp_mask, order,
3387 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3390 * If an allocation failed after direct reclaim, it could be because
3391 * pages are pinned on the per-cpu lists or in high alloc reserves.
3392 * Shrink them them and try again
3394 if (!page && !drained) {
3395 unreserve_highatomic_pageblock(ac);
3396 drain_all_pages(NULL);
3404 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3409 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3410 ac->high_zoneidx, ac->nodemask)
3411 wakeup_kswapd(zone, order, ac_classzone_idx(ac));
3414 static inline unsigned int
3415 gfp_to_alloc_flags(gfp_t gfp_mask)
3417 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3419 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3420 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3423 * The caller may dip into page reserves a bit more if the caller
3424 * cannot run direct reclaim, or if the caller has realtime scheduling
3425 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3426 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3428 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3430 if (gfp_mask & __GFP_ATOMIC) {
3432 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3433 * if it can't schedule.
3435 if (!(gfp_mask & __GFP_NOMEMALLOC))
3436 alloc_flags |= ALLOC_HARDER;
3438 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3439 * comment for __cpuset_node_allowed().
3441 alloc_flags &= ~ALLOC_CPUSET;
3442 } else if (unlikely(rt_task(current)) && !in_interrupt())
3443 alloc_flags |= ALLOC_HARDER;
3445 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3446 if (gfp_mask & __GFP_MEMALLOC)
3447 alloc_flags |= ALLOC_NO_WATERMARKS;
3448 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3449 alloc_flags |= ALLOC_NO_WATERMARKS;
3450 else if (!in_interrupt() &&
3451 ((current->flags & PF_MEMALLOC) ||
3452 unlikely(test_thread_flag(TIF_MEMDIE))))
3453 alloc_flags |= ALLOC_NO_WATERMARKS;
3456 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3457 alloc_flags |= ALLOC_CMA;
3462 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3464 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3467 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3469 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3473 * Maximum number of reclaim retries without any progress before OOM killer
3474 * is consider as the only way to move forward.
3476 #define MAX_RECLAIM_RETRIES 16
3479 * Checks whether it makes sense to retry the reclaim to make a forward progress
3480 * for the given allocation request.
3481 * The reclaim feedback represented by did_some_progress (any progress during
3482 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3483 * any progress in a row) is considered as well as the reclaimable pages on the
3484 * applicable zone list (with a backoff mechanism which is a function of
3485 * no_progress_loops).
3487 * Returns true if a retry is viable or false to enter the oom path.
3490 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3491 struct alloc_context *ac, int alloc_flags,
3492 bool did_some_progress, int no_progress_loops)
3498 * Make sure we converge to OOM if we cannot make any progress
3499 * several times in the row.
3501 if (no_progress_loops > MAX_RECLAIM_RETRIES)
3505 * Keep reclaiming pages while there is a chance this will lead somewhere.
3506 * If none of the target zones can satisfy our allocation request even
3507 * if all reclaimable pages are considered then we are screwed and have
3510 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3512 unsigned long available;
3513 unsigned long reclaimable;
3515 available = reclaimable = zone_reclaimable_pages(zone);
3516 available -= DIV_ROUND_UP(no_progress_loops * available,
3517 MAX_RECLAIM_RETRIES);
3518 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3521 * Would the allocation succeed if we reclaimed the whole
3524 if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
3525 ac_classzone_idx(ac), alloc_flags, available)) {
3527 * If we didn't make any progress and have a lot of
3528 * dirty + writeback pages then we should wait for
3529 * an IO to complete to slow down the reclaim and
3530 * prevent from pre mature OOM
3532 if (!did_some_progress) {
3533 unsigned long writeback;
3534 unsigned long dirty;
3536 writeback = zone_page_state_snapshot(zone,
3538 dirty = zone_page_state_snapshot(zone, NR_FILE_DIRTY);
3540 if (2*(writeback + dirty) > reclaimable) {
3541 congestion_wait(BLK_RW_ASYNC, HZ/10);
3547 * Memory allocation/reclaim might be called from a WQ
3548 * context and the current implementation of the WQ
3549 * concurrency control doesn't recognize that
3550 * a particular WQ is congested if the worker thread is
3551 * looping without ever sleeping. Therefore we have to
3552 * do a short sleep here rather than calling
3555 if (current->flags & PF_WQ_WORKER)
3556 schedule_timeout_uninterruptible(1);
3567 static inline struct page *
3568 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3569 struct alloc_context *ac)
3571 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3572 struct page *page = NULL;
3573 unsigned int alloc_flags;
3574 unsigned long did_some_progress;
3575 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3576 enum compact_result compact_result;
3577 int compaction_retries = 0;
3578 int no_progress_loops = 0;
3581 * In the slowpath, we sanity check order to avoid ever trying to
3582 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3583 * be using allocators in order of preference for an area that is
3586 if (order >= MAX_ORDER) {
3587 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3592 * We also sanity check to catch abuse of atomic reserves being used by
3593 * callers that are not in atomic context.
3595 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3596 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3597 gfp_mask &= ~__GFP_ATOMIC;
3600 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3601 wake_all_kswapds(order, ac);
3604 * OK, we're below the kswapd watermark and have kicked background
3605 * reclaim. Now things get more complex, so set up alloc_flags according
3606 * to how we want to proceed.
3608 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3611 * Reset the zonelist iterators if memory policies can be ignored.
3612 * These allocations are high priority and system rather than user
3615 if ((alloc_flags & ALLOC_NO_WATERMARKS) || !(alloc_flags & ALLOC_CPUSET)) {
3616 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3617 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
3618 ac->high_zoneidx, ac->nodemask);
3621 /* This is the last chance, in general, before the goto nopage. */
3622 page = get_page_from_freelist(gfp_mask, order,
3623 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3627 /* Allocate without watermarks if the context allows */
3628 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3629 page = get_page_from_freelist(gfp_mask, order,
3630 ALLOC_NO_WATERMARKS, ac);
3635 /* Caller is not willing to reclaim, we can't balance anything */
3636 if (!can_direct_reclaim) {
3638 * All existing users of the __GFP_NOFAIL are blockable, so warn
3639 * of any new users that actually allow this type of allocation
3642 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3646 /* Avoid recursion of direct reclaim */
3647 if (current->flags & PF_MEMALLOC) {
3649 * __GFP_NOFAIL request from this context is rather bizarre
3650 * because we cannot reclaim anything and only can loop waiting
3651 * for somebody to do a work for us.
3653 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3660 /* Avoid allocations with no watermarks from looping endlessly */
3661 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3665 * Try direct compaction. The first pass is asynchronous. Subsequent
3666 * attempts after direct reclaim are synchronous
3668 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3674 /* Checks for THP-specific high-order allocations */
3675 if (is_thp_gfp_mask(gfp_mask)) {
3677 * If compaction is deferred for high-order allocations, it is
3678 * because sync compaction recently failed. If this is the case
3679 * and the caller requested a THP allocation, we do not want
3680 * to heavily disrupt the system, so we fail the allocation
3681 * instead of entering direct reclaim.
3683 if (compact_result == COMPACT_DEFERRED)
3687 * Compaction is contended so rather back off than cause
3690 if(compact_result == COMPACT_CONTENDED)
3694 if (order && compaction_made_progress(compact_result))
3695 compaction_retries++;
3697 /* Try direct reclaim and then allocating */
3698 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3699 &did_some_progress);
3703 /* Do not loop if specifically requested */
3704 if (gfp_mask & __GFP_NORETRY)
3708 * Do not retry costly high order allocations unless they are
3711 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
3715 * Costly allocations might have made a progress but this doesn't mean
3716 * their order will become available due to high fragmentation so
3717 * always increment the no progress counter for them
3719 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3720 no_progress_loops = 0;
3722 no_progress_loops++;
3724 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
3725 did_some_progress > 0, no_progress_loops))
3729 * It doesn't make any sense to retry for the compaction if the order-0
3730 * reclaim is not able to make any progress because the current
3731 * implementation of the compaction depends on the sufficient amount
3732 * of free memory (see __compaction_suitable)
3734 if (did_some_progress > 0 &&
3735 should_compact_retry(ac, order, alloc_flags,
3736 compact_result, &migration_mode,
3737 compaction_retries))
3740 /* Reclaim has failed us, start killing things */
3741 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3745 /* Retry as long as the OOM killer is making progress */
3746 if (did_some_progress) {
3747 no_progress_loops = 0;
3753 * High-order allocations do not necessarily loop after direct reclaim
3754 * and reclaim/compaction depends on compaction being called after
3755 * reclaim so call directly if necessary.
3756 * It can become very expensive to allocate transparent hugepages at
3757 * fault, so use asynchronous memory compaction for THP unless it is
3758 * khugepaged trying to collapse. All other requests should tolerate
3759 * at least light sync migration.
3761 if (is_thp_gfp_mask(gfp_mask) && !(current->flags & PF_KTHREAD))
3762 migration_mode = MIGRATE_ASYNC;
3764 migration_mode = MIGRATE_SYNC_LIGHT;
3765 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3771 warn_alloc_failed(gfp_mask, order, NULL);
3777 * This is the 'heart' of the zoned buddy allocator.
3780 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3781 struct zonelist *zonelist, nodemask_t *nodemask)
3784 unsigned int cpuset_mems_cookie;
3785 unsigned int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR;
3786 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3787 struct alloc_context ac = {
3788 .high_zoneidx = gfp_zone(gfp_mask),
3789 .zonelist = zonelist,
3790 .nodemask = nodemask,
3791 .migratetype = gfpflags_to_migratetype(gfp_mask),
3794 if (cpusets_enabled()) {
3795 alloc_mask |= __GFP_HARDWALL;
3796 alloc_flags |= ALLOC_CPUSET;
3798 ac.nodemask = &cpuset_current_mems_allowed;
3801 gfp_mask &= gfp_allowed_mask;
3803 lockdep_trace_alloc(gfp_mask);
3805 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3807 if (should_fail_alloc_page(gfp_mask, order))
3811 * Check the zones suitable for the gfp_mask contain at least one
3812 * valid zone. It's possible to have an empty zonelist as a result
3813 * of __GFP_THISNODE and a memoryless node
3815 if (unlikely(!zonelist->_zonerefs->zone))
3818 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3819 alloc_flags |= ALLOC_CMA;
3822 cpuset_mems_cookie = read_mems_allowed_begin();
3824 /* Dirty zone balancing only done in the fast path */
3825 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3828 * The preferred zone is used for statistics but crucially it is
3829 * also used as the starting point for the zonelist iterator. It
3830 * may get reset for allocations that ignore memory policies.
3832 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3833 ac.high_zoneidx, ac.nodemask);
3834 if (!ac.preferred_zoneref) {
3839 /* First allocation attempt */
3840 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3845 * Runtime PM, block IO and its error handling path can deadlock
3846 * because I/O on the device might not complete.
3848 alloc_mask = memalloc_noio_flags(gfp_mask);
3849 ac.spread_dirty_pages = false;
3852 * Restore the original nodemask if it was potentially replaced with
3853 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3855 if (cpusets_enabled())
3856 ac.nodemask = nodemask;
3857 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3861 * When updating a task's mems_allowed, it is possible to race with
3862 * parallel threads in such a way that an allocation can fail while
3863 * the mask is being updated. If a page allocation is about to fail,
3864 * check if the cpuset changed during allocation and if so, retry.
3866 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3867 alloc_mask = gfp_mask;
3872 if (kmemcheck_enabled && page)
3873 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3875 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3879 EXPORT_SYMBOL(__alloc_pages_nodemask);
3882 * Common helper functions.
3884 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3889 * __get_free_pages() returns a 32-bit address, which cannot represent
3892 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3894 page = alloc_pages(gfp_mask, order);
3897 return (unsigned long) page_address(page);
3899 EXPORT_SYMBOL(__get_free_pages);
3901 unsigned long get_zeroed_page(gfp_t gfp_mask)
3903 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3905 EXPORT_SYMBOL(get_zeroed_page);
3907 void __free_pages(struct page *page, unsigned int order)
3909 if (put_page_testzero(page)) {
3911 free_hot_cold_page(page, false);
3913 __free_pages_ok(page, order);
3917 EXPORT_SYMBOL(__free_pages);
3919 void free_pages(unsigned long addr, unsigned int order)
3922 VM_BUG_ON(!virt_addr_valid((void *)addr));
3923 __free_pages(virt_to_page((void *)addr), order);
3927 EXPORT_SYMBOL(free_pages);
3931 * An arbitrary-length arbitrary-offset area of memory which resides
3932 * within a 0 or higher order page. Multiple fragments within that page
3933 * are individually refcounted, in the page's reference counter.
3935 * The page_frag functions below provide a simple allocation framework for
3936 * page fragments. This is used by the network stack and network device
3937 * drivers to provide a backing region of memory for use as either an
3938 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3940 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3943 struct page *page = NULL;
3944 gfp_t gfp = gfp_mask;
3946 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3947 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3949 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3950 PAGE_FRAG_CACHE_MAX_ORDER);
3951 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3953 if (unlikely(!page))
3954 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3956 nc->va = page ? page_address(page) : NULL;
3961 void *__alloc_page_frag(struct page_frag_cache *nc,
3962 unsigned int fragsz, gfp_t gfp_mask)
3964 unsigned int size = PAGE_SIZE;
3968 if (unlikely(!nc->va)) {
3970 page = __page_frag_refill(nc, gfp_mask);
3974 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3975 /* if size can vary use size else just use PAGE_SIZE */
3978 /* Even if we own the page, we do not use atomic_set().
3979 * This would break get_page_unless_zero() users.
3981 page_ref_add(page, size - 1);
3983 /* reset page count bias and offset to start of new frag */
3984 nc->pfmemalloc = page_is_pfmemalloc(page);
3985 nc->pagecnt_bias = size;
3989 offset = nc->offset - fragsz;
3990 if (unlikely(offset < 0)) {
3991 page = virt_to_page(nc->va);
3993 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3996 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3997 /* if size can vary use size else just use PAGE_SIZE */
4000 /* OK, page count is 0, we can safely set it */
4001 set_page_count(page, size);
4003 /* reset page count bias and offset to start of new frag */
4004 nc->pagecnt_bias = size;
4005 offset = size - fragsz;
4009 nc->offset = offset;
4011 return nc->va + offset;
4013 EXPORT_SYMBOL(__alloc_page_frag);
4016 * Frees a page fragment allocated out of either a compound or order 0 page.
4018 void __free_page_frag(void *addr)
4020 struct page *page = virt_to_head_page(addr);
4022 if (unlikely(put_page_testzero(page)))
4023 __free_pages_ok(page, compound_order(page));
4025 EXPORT_SYMBOL(__free_page_frag);
4028 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
4029 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
4030 * equivalent to alloc_pages.
4032 * It should be used when the caller would like to use kmalloc, but since the
4033 * allocation is large, it has to fall back to the page allocator.
4035 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
4039 page = alloc_pages(gfp_mask, order);
4040 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
4041 __free_pages(page, order);
4047 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
4051 page = alloc_pages_node(nid, gfp_mask, order);
4052 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
4053 __free_pages(page, order);
4060 * __free_kmem_pages and free_kmem_pages will free pages allocated with
4063 void __free_kmem_pages(struct page *page, unsigned int order)
4065 memcg_kmem_uncharge(page, order);
4066 __free_pages(page, order);
4069 void free_kmem_pages(unsigned long addr, unsigned int order)
4072 VM_BUG_ON(!virt_addr_valid((void *)addr));
4073 __free_kmem_pages(virt_to_page((void *)addr), order);
4077 static void *make_alloc_exact(unsigned long addr, unsigned int order,
4081 unsigned long alloc_end = addr + (PAGE_SIZE << order);
4082 unsigned long used = addr + PAGE_ALIGN(size);
4084 split_page(virt_to_page((void *)addr), order);
4085 while (used < alloc_end) {
4090 return (void *)addr;
4094 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4095 * @size: the number of bytes to allocate
4096 * @gfp_mask: GFP flags for the allocation
4098 * This function is similar to alloc_pages(), except that it allocates the
4099 * minimum number of pages to satisfy the request. alloc_pages() can only
4100 * allocate memory in power-of-two pages.
4102 * This function is also limited by MAX_ORDER.
4104 * Memory allocated by this function must be released by free_pages_exact().
4106 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
4108 unsigned int order = get_order(size);
4111 addr = __get_free_pages(gfp_mask, order);
4112 return make_alloc_exact(addr, order, size);
4114 EXPORT_SYMBOL(alloc_pages_exact);
4117 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4119 * @nid: the preferred node ID where memory should be allocated
4120 * @size: the number of bytes to allocate
4121 * @gfp_mask: GFP flags for the allocation
4123 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4126 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4128 unsigned int order = get_order(size);
4129 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4132 return make_alloc_exact((unsigned long)page_address(p), order, size);
4136 * free_pages_exact - release memory allocated via alloc_pages_exact()
4137 * @virt: the value returned by alloc_pages_exact.
4138 * @size: size of allocation, same value as passed to alloc_pages_exact().
4140 * Release the memory allocated by a previous call to alloc_pages_exact.
4142 void free_pages_exact(void *virt, size_t size)
4144 unsigned long addr = (unsigned long)virt;
4145 unsigned long end = addr + PAGE_ALIGN(size);
4147 while (addr < end) {
4152 EXPORT_SYMBOL(free_pages_exact);
4155 * nr_free_zone_pages - count number of pages beyond high watermark
4156 * @offset: The zone index of the highest zone
4158 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4159 * high watermark within all zones at or below a given zone index. For each
4160 * zone, the number of pages is calculated as:
4161 * managed_pages - high_pages
4163 static unsigned long nr_free_zone_pages(int offset)
4168 /* Just pick one node, since fallback list is circular */
4169 unsigned long sum = 0;
4171 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4173 for_each_zone_zonelist(zone, z, zonelist, offset) {
4174 unsigned long size = zone->managed_pages;
4175 unsigned long high = high_wmark_pages(zone);
4184 * nr_free_buffer_pages - count number of pages beyond high watermark
4186 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4187 * watermark within ZONE_DMA and ZONE_NORMAL.
4189 unsigned long nr_free_buffer_pages(void)
4191 return nr_free_zone_pages(gfp_zone(GFP_USER));
4193 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4196 * nr_free_pagecache_pages - count number of pages beyond high watermark
4198 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4199 * high watermark within all zones.
4201 unsigned long nr_free_pagecache_pages(void)
4203 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4206 static inline void show_node(struct zone *zone)
4208 if (IS_ENABLED(CONFIG_NUMA))
4209 printk("Node %d ", zone_to_nid(zone));
4212 long si_mem_available(void)
4215 unsigned long pagecache;
4216 unsigned long wmark_low = 0;
4217 unsigned long pages[NR_LRU_LISTS];
4221 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4222 pages[lru] = global_page_state(NR_LRU_BASE + lru);
4225 wmark_low += zone->watermark[WMARK_LOW];
4228 * Estimate the amount of memory available for userspace allocations,
4229 * without causing swapping.
4231 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
4234 * Not all the page cache can be freed, otherwise the system will
4235 * start swapping. Assume at least half of the page cache, or the
4236 * low watermark worth of cache, needs to stay.
4238 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4239 pagecache -= min(pagecache / 2, wmark_low);
4240 available += pagecache;
4243 * Part of the reclaimable slab consists of items that are in use,
4244 * and cannot be freed. Cap this estimate at the low watermark.
4246 available += global_page_state(NR_SLAB_RECLAIMABLE) -
4247 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
4253 EXPORT_SYMBOL_GPL(si_mem_available);
4255 void si_meminfo(struct sysinfo *val)
4257 val->totalram = totalram_pages;
4258 val->sharedram = global_page_state(NR_SHMEM);
4259 val->freeram = global_page_state(NR_FREE_PAGES);
4260 val->bufferram = nr_blockdev_pages();
4261 val->totalhigh = totalhigh_pages;
4262 val->freehigh = nr_free_highpages();
4263 val->mem_unit = PAGE_SIZE;
4266 EXPORT_SYMBOL(si_meminfo);
4269 void si_meminfo_node(struct sysinfo *val, int nid)
4271 int zone_type; /* needs to be signed */
4272 unsigned long managed_pages = 0;
4273 unsigned long managed_highpages = 0;
4274 unsigned long free_highpages = 0;
4275 pg_data_t *pgdat = NODE_DATA(nid);
4277 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4278 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4279 val->totalram = managed_pages;
4280 val->sharedram = node_page_state(nid, NR_SHMEM);
4281 val->freeram = node_page_state(nid, NR_FREE_PAGES);
4282 #ifdef CONFIG_HIGHMEM
4283 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4284 struct zone *zone = &pgdat->node_zones[zone_type];
4286 if (is_highmem(zone)) {
4287 managed_highpages += zone->managed_pages;
4288 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4291 val->totalhigh = managed_highpages;
4292 val->freehigh = free_highpages;
4294 val->totalhigh = managed_highpages;
4295 val->freehigh = free_highpages;
4297 val->mem_unit = PAGE_SIZE;
4302 * Determine whether the node should be displayed or not, depending on whether
4303 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4305 bool skip_free_areas_node(unsigned int flags, int nid)
4308 unsigned int cpuset_mems_cookie;
4310 if (!(flags & SHOW_MEM_FILTER_NODES))
4314 cpuset_mems_cookie = read_mems_allowed_begin();
4315 ret = !node_isset(nid, cpuset_current_mems_allowed);
4316 } while (read_mems_allowed_retry(cpuset_mems_cookie));
4321 #define K(x) ((x) << (PAGE_SHIFT-10))
4323 static void show_migration_types(unsigned char type)
4325 static const char types[MIGRATE_TYPES] = {
4326 [MIGRATE_UNMOVABLE] = 'U',
4327 [MIGRATE_MOVABLE] = 'M',
4328 [MIGRATE_RECLAIMABLE] = 'E',
4329 [MIGRATE_HIGHATOMIC] = 'H',
4331 [MIGRATE_CMA] = 'C',
4333 #ifdef CONFIG_MEMORY_ISOLATION
4334 [MIGRATE_ISOLATE] = 'I',
4337 char tmp[MIGRATE_TYPES + 1];
4341 for (i = 0; i < MIGRATE_TYPES; i++) {
4342 if (type & (1 << i))
4347 printk("(%s) ", tmp);
4351 * Show free area list (used inside shift_scroll-lock stuff)
4352 * We also calculate the percentage fragmentation. We do this by counting the
4353 * memory on each free list with the exception of the first item on the list.
4356 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4359 void show_free_areas(unsigned int filter)
4361 unsigned long free_pcp = 0;
4365 for_each_populated_zone(zone) {
4366 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4369 for_each_online_cpu(cpu)
4370 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4373 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4374 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4375 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4376 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4377 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4378 " free:%lu free_pcp:%lu free_cma:%lu\n",
4379 global_page_state(NR_ACTIVE_ANON),
4380 global_page_state(NR_INACTIVE_ANON),
4381 global_page_state(NR_ISOLATED_ANON),
4382 global_page_state(NR_ACTIVE_FILE),
4383 global_page_state(NR_INACTIVE_FILE),
4384 global_page_state(NR_ISOLATED_FILE),
4385 global_page_state(NR_UNEVICTABLE),
4386 global_page_state(NR_FILE_DIRTY),
4387 global_page_state(NR_WRITEBACK),
4388 global_page_state(NR_UNSTABLE_NFS),
4389 global_page_state(NR_SLAB_RECLAIMABLE),
4390 global_page_state(NR_SLAB_UNRECLAIMABLE),
4391 global_page_state(NR_FILE_MAPPED),
4392 global_page_state(NR_SHMEM),
4393 global_page_state(NR_PAGETABLE),
4394 global_page_state(NR_BOUNCE),
4395 global_page_state(NR_FREE_PAGES),
4397 global_page_state(NR_FREE_CMA_PAGES));
4399 for_each_populated_zone(zone) {
4402 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4406 for_each_online_cpu(cpu)
4407 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4415 " active_anon:%lukB"
4416 " inactive_anon:%lukB"
4417 " active_file:%lukB"
4418 " inactive_file:%lukB"
4419 " unevictable:%lukB"
4420 " isolated(anon):%lukB"
4421 " isolated(file):%lukB"
4429 " slab_reclaimable:%lukB"
4430 " slab_unreclaimable:%lukB"
4431 " kernel_stack:%lukB"
4438 " writeback_tmp:%lukB"
4439 " pages_scanned:%lu"
4440 " all_unreclaimable? %s"
4443 K(zone_page_state(zone, NR_FREE_PAGES)),
4444 K(min_wmark_pages(zone)),
4445 K(low_wmark_pages(zone)),
4446 K(high_wmark_pages(zone)),
4447 K(zone_page_state(zone, NR_ACTIVE_ANON)),
4448 K(zone_page_state(zone, NR_INACTIVE_ANON)),
4449 K(zone_page_state(zone, NR_ACTIVE_FILE)),
4450 K(zone_page_state(zone, NR_INACTIVE_FILE)),
4451 K(zone_page_state(zone, NR_UNEVICTABLE)),
4452 K(zone_page_state(zone, NR_ISOLATED_ANON)),
4453 K(zone_page_state(zone, NR_ISOLATED_FILE)),
4454 K(zone->present_pages),
4455 K(zone->managed_pages),
4456 K(zone_page_state(zone, NR_MLOCK)),
4457 K(zone_page_state(zone, NR_FILE_DIRTY)),
4458 K(zone_page_state(zone, NR_WRITEBACK)),
4459 K(zone_page_state(zone, NR_FILE_MAPPED)),
4460 K(zone_page_state(zone, NR_SHMEM)),
4461 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4462 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4463 zone_page_state(zone, NR_KERNEL_STACK) *
4465 K(zone_page_state(zone, NR_PAGETABLE)),
4466 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
4467 K(zone_page_state(zone, NR_BOUNCE)),
4469 K(this_cpu_read(zone->pageset->pcp.count)),
4470 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
4471 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
4472 K(zone_page_state(zone, NR_PAGES_SCANNED)),
4473 (!zone_reclaimable(zone) ? "yes" : "no")
4475 printk("lowmem_reserve[]:");
4476 for (i = 0; i < MAX_NR_ZONES; i++)
4477 printk(" %ld", zone->lowmem_reserve[i]);
4481 for_each_populated_zone(zone) {
4483 unsigned long nr[MAX_ORDER], flags, total = 0;
4484 unsigned char types[MAX_ORDER];
4486 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4489 printk("%s: ", zone->name);
4491 spin_lock_irqsave(&zone->lock, flags);
4492 for (order = 0; order < MAX_ORDER; order++) {
4493 struct free_area *area = &zone->free_area[order];
4496 nr[order] = area->nr_free;
4497 total += nr[order] << order;
4500 for (type = 0; type < MIGRATE_TYPES; type++) {
4501 if (!list_empty(&area->free_list[type]))
4502 types[order] |= 1 << type;
4505 spin_unlock_irqrestore(&zone->lock, flags);
4506 for (order = 0; order < MAX_ORDER; order++) {
4507 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4509 show_migration_types(types[order]);
4511 printk("= %lukB\n", K(total));
4514 hugetlb_show_meminfo();
4516 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4518 show_swap_cache_info();
4521 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4523 zoneref->zone = zone;
4524 zoneref->zone_idx = zone_idx(zone);
4528 * Builds allocation fallback zone lists.
4530 * Add all populated zones of a node to the zonelist.
4532 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4536 enum zone_type zone_type = MAX_NR_ZONES;
4540 zone = pgdat->node_zones + zone_type;
4541 if (populated_zone(zone)) {
4542 zoneref_set_zone(zone,
4543 &zonelist->_zonerefs[nr_zones++]);
4544 check_highest_zone(zone_type);
4546 } while (zone_type);
4554 * 0 = automatic detection of better ordering.
4555 * 1 = order by ([node] distance, -zonetype)
4556 * 2 = order by (-zonetype, [node] distance)
4558 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4559 * the same zonelist. So only NUMA can configure this param.
4561 #define ZONELIST_ORDER_DEFAULT 0
4562 #define ZONELIST_ORDER_NODE 1
4563 #define ZONELIST_ORDER_ZONE 2
4565 /* zonelist order in the kernel.
4566 * set_zonelist_order() will set this to NODE or ZONE.
4568 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4569 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4573 /* The value user specified ....changed by config */
4574 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4575 /* string for sysctl */
4576 #define NUMA_ZONELIST_ORDER_LEN 16
4577 char numa_zonelist_order[16] = "default";
4580 * interface for configure zonelist ordering.
4581 * command line option "numa_zonelist_order"
4582 * = "[dD]efault - default, automatic configuration.
4583 * = "[nN]ode - order by node locality, then by zone within node
4584 * = "[zZ]one - order by zone, then by locality within zone
4587 static int __parse_numa_zonelist_order(char *s)
4589 if (*s == 'd' || *s == 'D') {
4590 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4591 } else if (*s == 'n' || *s == 'N') {
4592 user_zonelist_order = ZONELIST_ORDER_NODE;
4593 } else if (*s == 'z' || *s == 'Z') {
4594 user_zonelist_order = ZONELIST_ORDER_ZONE;
4596 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4602 static __init int setup_numa_zonelist_order(char *s)
4609 ret = __parse_numa_zonelist_order(s);
4611 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4615 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4618 * sysctl handler for numa_zonelist_order
4620 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4621 void __user *buffer, size_t *length,
4624 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4626 static DEFINE_MUTEX(zl_order_mutex);
4628 mutex_lock(&zl_order_mutex);
4630 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4634 strcpy(saved_string, (char *)table->data);
4636 ret = proc_dostring(table, write, buffer, length, ppos);
4640 int oldval = user_zonelist_order;
4642 ret = __parse_numa_zonelist_order((char *)table->data);
4645 * bogus value. restore saved string
4647 strncpy((char *)table->data, saved_string,
4648 NUMA_ZONELIST_ORDER_LEN);
4649 user_zonelist_order = oldval;
4650 } else if (oldval != user_zonelist_order) {
4651 mutex_lock(&zonelists_mutex);
4652 build_all_zonelists(NULL, NULL);
4653 mutex_unlock(&zonelists_mutex);
4657 mutex_unlock(&zl_order_mutex);
4662 #define MAX_NODE_LOAD (nr_online_nodes)
4663 static int node_load[MAX_NUMNODES];
4666 * find_next_best_node - find the next node that should appear in a given node's fallback list
4667 * @node: node whose fallback list we're appending
4668 * @used_node_mask: nodemask_t of already used nodes
4670 * We use a number of factors to determine which is the next node that should
4671 * appear on a given node's fallback list. The node should not have appeared
4672 * already in @node's fallback list, and it should be the next closest node
4673 * according to the distance array (which contains arbitrary distance values
4674 * from each node to each node in the system), and should also prefer nodes
4675 * with no CPUs, since presumably they'll have very little allocation pressure
4676 * on them otherwise.
4677 * It returns -1 if no node is found.
4679 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4682 int min_val = INT_MAX;
4683 int best_node = NUMA_NO_NODE;
4684 const struct cpumask *tmp = cpumask_of_node(0);
4686 /* Use the local node if we haven't already */
4687 if (!node_isset(node, *used_node_mask)) {
4688 node_set(node, *used_node_mask);
4692 for_each_node_state(n, N_MEMORY) {
4694 /* Don't want a node to appear more than once */
4695 if (node_isset(n, *used_node_mask))
4698 /* Use the distance array to find the distance */
4699 val = node_distance(node, n);
4701 /* Penalize nodes under us ("prefer the next node") */
4704 /* Give preference to headless and unused nodes */
4705 tmp = cpumask_of_node(n);
4706 if (!cpumask_empty(tmp))
4707 val += PENALTY_FOR_NODE_WITH_CPUS;
4709 /* Slight preference for less loaded node */
4710 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4711 val += node_load[n];
4713 if (val < min_val) {
4720 node_set(best_node, *used_node_mask);
4727 * Build zonelists ordered by node and zones within node.
4728 * This results in maximum locality--normal zone overflows into local
4729 * DMA zone, if any--but risks exhausting DMA zone.
4731 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4734 struct zonelist *zonelist;
4736 zonelist = &pgdat->node_zonelists[0];
4737 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4739 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4740 zonelist->_zonerefs[j].zone = NULL;
4741 zonelist->_zonerefs[j].zone_idx = 0;
4745 * Build gfp_thisnode zonelists
4747 static void build_thisnode_zonelists(pg_data_t *pgdat)
4750 struct zonelist *zonelist;
4752 zonelist = &pgdat->node_zonelists[1];
4753 j = build_zonelists_node(pgdat, zonelist, 0);
4754 zonelist->_zonerefs[j].zone = NULL;
4755 zonelist->_zonerefs[j].zone_idx = 0;
4759 * Build zonelists ordered by zone and nodes within zones.
4760 * This results in conserving DMA zone[s] until all Normal memory is
4761 * exhausted, but results in overflowing to remote node while memory
4762 * may still exist in local DMA zone.
4764 static int node_order[MAX_NUMNODES];
4766 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4769 int zone_type; /* needs to be signed */
4771 struct zonelist *zonelist;
4773 zonelist = &pgdat->node_zonelists[0];
4775 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4776 for (j = 0; j < nr_nodes; j++) {
4777 node = node_order[j];
4778 z = &NODE_DATA(node)->node_zones[zone_type];
4779 if (populated_zone(z)) {
4781 &zonelist->_zonerefs[pos++]);
4782 check_highest_zone(zone_type);
4786 zonelist->_zonerefs[pos].zone = NULL;
4787 zonelist->_zonerefs[pos].zone_idx = 0;
4790 #if defined(CONFIG_64BIT)
4792 * Devices that require DMA32/DMA are relatively rare and do not justify a
4793 * penalty to every machine in case the specialised case applies. Default
4794 * to Node-ordering on 64-bit NUMA machines
4796 static int default_zonelist_order(void)
4798 return ZONELIST_ORDER_NODE;
4802 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4803 * by the kernel. If processes running on node 0 deplete the low memory zone
4804 * then reclaim will occur more frequency increasing stalls and potentially
4805 * be easier to OOM if a large percentage of the zone is under writeback or
4806 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4807 * Hence, default to zone ordering on 32-bit.
4809 static int default_zonelist_order(void)
4811 return ZONELIST_ORDER_ZONE;
4813 #endif /* CONFIG_64BIT */
4815 static void set_zonelist_order(void)
4817 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4818 current_zonelist_order = default_zonelist_order();
4820 current_zonelist_order = user_zonelist_order;
4823 static void build_zonelists(pg_data_t *pgdat)
4826 nodemask_t used_mask;
4827 int local_node, prev_node;
4828 struct zonelist *zonelist;
4829 unsigned int order = current_zonelist_order;
4831 /* initialize zonelists */
4832 for (i = 0; i < MAX_ZONELISTS; i++) {
4833 zonelist = pgdat->node_zonelists + i;
4834 zonelist->_zonerefs[0].zone = NULL;
4835 zonelist->_zonerefs[0].zone_idx = 0;
4838 /* NUMA-aware ordering of nodes */
4839 local_node = pgdat->node_id;
4840 load = nr_online_nodes;
4841 prev_node = local_node;
4842 nodes_clear(used_mask);
4844 memset(node_order, 0, sizeof(node_order));
4847 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4849 * We don't want to pressure a particular node.
4850 * So adding penalty to the first node in same
4851 * distance group to make it round-robin.
4853 if (node_distance(local_node, node) !=
4854 node_distance(local_node, prev_node))
4855 node_load[node] = load;
4859 if (order == ZONELIST_ORDER_NODE)
4860 build_zonelists_in_node_order(pgdat, node);
4862 node_order[i++] = node; /* remember order */
4865 if (order == ZONELIST_ORDER_ZONE) {
4866 /* calculate node order -- i.e., DMA last! */
4867 build_zonelists_in_zone_order(pgdat, i);
4870 build_thisnode_zonelists(pgdat);
4873 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4875 * Return node id of node used for "local" allocations.
4876 * I.e., first node id of first zone in arg node's generic zonelist.
4877 * Used for initializing percpu 'numa_mem', which is used primarily
4878 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4880 int local_memory_node(int node)
4884 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4885 gfp_zone(GFP_KERNEL),
4887 return z->zone->node;
4891 #else /* CONFIG_NUMA */
4893 static void set_zonelist_order(void)
4895 current_zonelist_order = ZONELIST_ORDER_ZONE;
4898 static void build_zonelists(pg_data_t *pgdat)
4900 int node, local_node;
4902 struct zonelist *zonelist;
4904 local_node = pgdat->node_id;
4906 zonelist = &pgdat->node_zonelists[0];
4907 j = build_zonelists_node(pgdat, zonelist, 0);
4910 * Now we build the zonelist so that it contains the zones
4911 * of all the other nodes.
4912 * We don't want to pressure a particular node, so when
4913 * building the zones for node N, we make sure that the
4914 * zones coming right after the local ones are those from
4915 * node N+1 (modulo N)
4917 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4918 if (!node_online(node))
4920 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4922 for (node = 0; node < local_node; node++) {
4923 if (!node_online(node))
4925 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4928 zonelist->_zonerefs[j].zone = NULL;
4929 zonelist->_zonerefs[j].zone_idx = 0;
4932 #endif /* CONFIG_NUMA */
4935 * Boot pageset table. One per cpu which is going to be used for all
4936 * zones and all nodes. The parameters will be set in such a way
4937 * that an item put on a list will immediately be handed over to
4938 * the buddy list. This is safe since pageset manipulation is done
4939 * with interrupts disabled.
4941 * The boot_pagesets must be kept even after bootup is complete for
4942 * unused processors and/or zones. They do play a role for bootstrapping
4943 * hotplugged processors.
4945 * zoneinfo_show() and maybe other functions do
4946 * not check if the processor is online before following the pageset pointer.
4947 * Other parts of the kernel may not check if the zone is available.
4949 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4950 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4951 static void setup_zone_pageset(struct zone *zone);
4954 * Global mutex to protect against size modification of zonelists
4955 * as well as to serialize pageset setup for the new populated zone.
4957 DEFINE_MUTEX(zonelists_mutex);
4959 /* return values int ....just for stop_machine() */
4960 static int __build_all_zonelists(void *data)
4964 pg_data_t *self = data;
4967 memset(node_load, 0, sizeof(node_load));
4970 if (self && !node_online(self->node_id)) {
4971 build_zonelists(self);
4974 for_each_online_node(nid) {
4975 pg_data_t *pgdat = NODE_DATA(nid);
4977 build_zonelists(pgdat);
4981 * Initialize the boot_pagesets that are going to be used
4982 * for bootstrapping processors. The real pagesets for
4983 * each zone will be allocated later when the per cpu
4984 * allocator is available.
4986 * boot_pagesets are used also for bootstrapping offline
4987 * cpus if the system is already booted because the pagesets
4988 * are needed to initialize allocators on a specific cpu too.
4989 * F.e. the percpu allocator needs the page allocator which
4990 * needs the percpu allocator in order to allocate its pagesets
4991 * (a chicken-egg dilemma).
4993 for_each_possible_cpu(cpu) {
4994 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4996 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4998 * We now know the "local memory node" for each node--
4999 * i.e., the node of the first zone in the generic zonelist.
5000 * Set up numa_mem percpu variable for on-line cpus. During
5001 * boot, only the boot cpu should be on-line; we'll init the
5002 * secondary cpus' numa_mem as they come on-line. During
5003 * node/memory hotplug, we'll fixup all on-line cpus.
5005 if (cpu_online(cpu))
5006 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
5013 static noinline void __init
5014 build_all_zonelists_init(void)
5016 __build_all_zonelists(NULL);
5017 mminit_verify_zonelist();
5018 cpuset_init_current_mems_allowed();
5022 * Called with zonelists_mutex held always
5023 * unless system_state == SYSTEM_BOOTING.
5025 * __ref due to (1) call of __meminit annotated setup_zone_pageset
5026 * [we're only called with non-NULL zone through __meminit paths] and
5027 * (2) call of __init annotated helper build_all_zonelists_init
5028 * [protected by SYSTEM_BOOTING].
5030 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
5032 set_zonelist_order();
5034 if (system_state == SYSTEM_BOOTING) {
5035 build_all_zonelists_init();
5037 #ifdef CONFIG_MEMORY_HOTPLUG
5039 setup_zone_pageset(zone);
5041 /* we have to stop all cpus to guarantee there is no user
5043 stop_machine(__build_all_zonelists, pgdat, NULL);
5044 /* cpuset refresh routine should be here */
5046 vm_total_pages = nr_free_pagecache_pages();
5048 * Disable grouping by mobility if the number of pages in the
5049 * system is too low to allow the mechanism to work. It would be
5050 * more accurate, but expensive to check per-zone. This check is
5051 * made on memory-hotadd so a system can start with mobility
5052 * disabled and enable it later
5054 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
5055 page_group_by_mobility_disabled = 1;
5057 page_group_by_mobility_disabled = 0;
5059 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5061 zonelist_order_name[current_zonelist_order],
5062 page_group_by_mobility_disabled ? "off" : "on",
5065 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
5070 * Helper functions to size the waitqueue hash table.
5071 * Essentially these want to choose hash table sizes sufficiently
5072 * large so that collisions trying to wait on pages are rare.
5073 * But in fact, the number of active page waitqueues on typical
5074 * systems is ridiculously low, less than 200. So this is even
5075 * conservative, even though it seems large.
5077 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
5078 * waitqueues, i.e. the size of the waitq table given the number of pages.
5080 #define PAGES_PER_WAITQUEUE 256
5082 #ifndef CONFIG_MEMORY_HOTPLUG
5083 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
5085 unsigned long size = 1;
5087 pages /= PAGES_PER_WAITQUEUE;
5089 while (size < pages)
5093 * Once we have dozens or even hundreds of threads sleeping
5094 * on IO we've got bigger problems than wait queue collision.
5095 * Limit the size of the wait table to a reasonable size.
5097 size = min(size, 4096UL);
5099 return max(size, 4UL);
5103 * A zone's size might be changed by hot-add, so it is not possible to determine
5104 * a suitable size for its wait_table. So we use the maximum size now.
5106 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5108 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5109 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5110 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5112 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5113 * or more by the traditional way. (See above). It equals:
5115 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5116 * ia64(16K page size) : = ( 8G + 4M)byte.
5117 * powerpc (64K page size) : = (32G +16M)byte.
5119 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
5126 * This is an integer logarithm so that shifts can be used later
5127 * to extract the more random high bits from the multiplicative
5128 * hash function before the remainder is taken.
5130 static inline unsigned long wait_table_bits(unsigned long size)
5136 * Initially all pages are reserved - free ones are freed
5137 * up by free_all_bootmem() once the early boot process is
5138 * done. Non-atomic initialization, single-pass.
5140 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5141 unsigned long start_pfn, enum memmap_context context)
5143 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
5144 unsigned long end_pfn = start_pfn + size;
5145 pg_data_t *pgdat = NODE_DATA(nid);
5147 unsigned long nr_initialised = 0;
5148 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5149 struct memblock_region *r = NULL, *tmp;
5152 if (highest_memmap_pfn < end_pfn - 1)
5153 highest_memmap_pfn = end_pfn - 1;
5156 * Honor reservation requested by the driver for this ZONE_DEVICE
5159 if (altmap && start_pfn == altmap->base_pfn)
5160 start_pfn += altmap->reserve;
5162 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5164 * There can be holes in boot-time mem_map[]s handed to this
5165 * function. They do not exist on hotplugged memory.
5167 if (context != MEMMAP_EARLY)
5170 if (!early_pfn_valid(pfn))
5172 if (!early_pfn_in_nid(pfn, nid))
5174 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5177 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5179 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5180 * from zone_movable_pfn[nid] to end of each node should be
5181 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5183 if (!mirrored_kernelcore && zone_movable_pfn[nid])
5184 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
5188 * Check given memblock attribute by firmware which can affect
5189 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5190 * mirrored, it's an overlapped memmap init. skip it.
5192 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5193 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5194 for_each_memblock(memory, tmp)
5195 if (pfn < memblock_region_memory_end_pfn(tmp))
5199 if (pfn >= memblock_region_memory_base_pfn(r) &&
5200 memblock_is_mirror(r)) {
5201 /* already initialized as NORMAL */
5202 pfn = memblock_region_memory_end_pfn(r);
5210 * Mark the block movable so that blocks are reserved for
5211 * movable at startup. This will force kernel allocations
5212 * to reserve their blocks rather than leaking throughout
5213 * the address space during boot when many long-lived
5214 * kernel allocations are made.
5216 * bitmap is created for zone's valid pfn range. but memmap
5217 * can be created for invalid pages (for alignment)
5218 * check here not to call set_pageblock_migratetype() against
5221 if (!(pfn & (pageblock_nr_pages - 1))) {
5222 struct page *page = pfn_to_page(pfn);
5224 __init_single_page(page, pfn, zone, nid);
5225 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5227 __init_single_pfn(pfn, zone, nid);
5232 static void __meminit zone_init_free_lists(struct zone *zone)
5234 unsigned int order, t;
5235 for_each_migratetype_order(order, t) {
5236 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5237 zone->free_area[order].nr_free = 0;
5241 #ifndef __HAVE_ARCH_MEMMAP_INIT
5242 #define memmap_init(size, nid, zone, start_pfn) \
5243 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5246 static int zone_batchsize(struct zone *zone)
5252 * The per-cpu-pages pools are set to around 1000th of the
5253 * size of the zone. But no more than 1/2 of a meg.
5255 * OK, so we don't know how big the cache is. So guess.
5257 batch = zone->managed_pages / 1024;
5258 if (batch * PAGE_SIZE > 512 * 1024)
5259 batch = (512 * 1024) / PAGE_SIZE;
5260 batch /= 4; /* We effectively *= 4 below */
5265 * Clamp the batch to a 2^n - 1 value. Having a power
5266 * of 2 value was found to be more likely to have
5267 * suboptimal cache aliasing properties in some cases.
5269 * For example if 2 tasks are alternately allocating
5270 * batches of pages, one task can end up with a lot
5271 * of pages of one half of the possible page colors
5272 * and the other with pages of the other colors.
5274 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5279 /* The deferral and batching of frees should be suppressed under NOMMU
5282 * The problem is that NOMMU needs to be able to allocate large chunks
5283 * of contiguous memory as there's no hardware page translation to
5284 * assemble apparent contiguous memory from discontiguous pages.
5286 * Queueing large contiguous runs of pages for batching, however,
5287 * causes the pages to actually be freed in smaller chunks. As there
5288 * can be a significant delay between the individual batches being
5289 * recycled, this leads to the once large chunks of space being
5290 * fragmented and becoming unavailable for high-order allocations.
5297 * pcp->high and pcp->batch values are related and dependent on one another:
5298 * ->batch must never be higher then ->high.
5299 * The following function updates them in a safe manner without read side
5302 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5303 * those fields changing asynchronously (acording the the above rule).
5305 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5306 * outside of boot time (or some other assurance that no concurrent updaters
5309 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5310 unsigned long batch)
5312 /* start with a fail safe value for batch */
5316 /* Update high, then batch, in order */
5323 /* a companion to pageset_set_high() */
5324 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5326 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5329 static void pageset_init(struct per_cpu_pageset *p)
5331 struct per_cpu_pages *pcp;
5334 memset(p, 0, sizeof(*p));
5338 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5339 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5342 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5345 pageset_set_batch(p, batch);
5349 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5350 * to the value high for the pageset p.
5352 static void pageset_set_high(struct per_cpu_pageset *p,
5355 unsigned long batch = max(1UL, high / 4);
5356 if ((high / 4) > (PAGE_SHIFT * 8))
5357 batch = PAGE_SHIFT * 8;
5359 pageset_update(&p->pcp, high, batch);
5362 static void pageset_set_high_and_batch(struct zone *zone,
5363 struct per_cpu_pageset *pcp)
5365 if (percpu_pagelist_fraction)
5366 pageset_set_high(pcp,
5367 (zone->managed_pages /
5368 percpu_pagelist_fraction));
5370 pageset_set_batch(pcp, zone_batchsize(zone));
5373 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5375 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5378 pageset_set_high_and_batch(zone, pcp);
5381 static void __meminit setup_zone_pageset(struct zone *zone)
5384 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5385 for_each_possible_cpu(cpu)
5386 zone_pageset_init(zone, cpu);
5390 * Allocate per cpu pagesets and initialize them.
5391 * Before this call only boot pagesets were available.
5393 void __init setup_per_cpu_pageset(void)
5397 for_each_populated_zone(zone)
5398 setup_zone_pageset(zone);
5401 static noinline __init_refok
5402 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
5408 * The per-page waitqueue mechanism uses hashed waitqueues
5411 zone->wait_table_hash_nr_entries =
5412 wait_table_hash_nr_entries(zone_size_pages);
5413 zone->wait_table_bits =
5414 wait_table_bits(zone->wait_table_hash_nr_entries);
5415 alloc_size = zone->wait_table_hash_nr_entries
5416 * sizeof(wait_queue_head_t);
5418 if (!slab_is_available()) {
5419 zone->wait_table = (wait_queue_head_t *)
5420 memblock_virt_alloc_node_nopanic(
5421 alloc_size, zone->zone_pgdat->node_id);
5424 * This case means that a zone whose size was 0 gets new memory
5425 * via memory hot-add.
5426 * But it may be the case that a new node was hot-added. In
5427 * this case vmalloc() will not be able to use this new node's
5428 * memory - this wait_table must be initialized to use this new
5429 * node itself as well.
5430 * To use this new node's memory, further consideration will be
5433 zone->wait_table = vmalloc(alloc_size);
5435 if (!zone->wait_table)
5438 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
5439 init_waitqueue_head(zone->wait_table + i);
5444 static __meminit void zone_pcp_init(struct zone *zone)
5447 * per cpu subsystem is not up at this point. The following code
5448 * relies on the ability of the linker to provide the
5449 * offset of a (static) per cpu variable into the per cpu area.
5451 zone->pageset = &boot_pageset;
5453 if (populated_zone(zone))
5454 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5455 zone->name, zone->present_pages,
5456 zone_batchsize(zone));
5459 int __meminit init_currently_empty_zone(struct zone *zone,
5460 unsigned long zone_start_pfn,
5463 struct pglist_data *pgdat = zone->zone_pgdat;
5465 ret = zone_wait_table_init(zone, size);
5468 pgdat->nr_zones = zone_idx(zone) + 1;
5470 zone->zone_start_pfn = zone_start_pfn;
5472 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5473 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5475 (unsigned long)zone_idx(zone),
5476 zone_start_pfn, (zone_start_pfn + size));
5478 zone_init_free_lists(zone);
5483 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5484 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5487 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5489 int __meminit __early_pfn_to_nid(unsigned long pfn,
5490 struct mminit_pfnnid_cache *state)
5492 unsigned long start_pfn, end_pfn;
5495 if (state->last_start <= pfn && pfn < state->last_end)
5496 return state->last_nid;
5498 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5500 state->last_start = start_pfn;
5501 state->last_end = end_pfn;
5502 state->last_nid = nid;
5507 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5510 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5511 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5512 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5514 * If an architecture guarantees that all ranges registered contain no holes
5515 * and may be freed, this this function may be used instead of calling
5516 * memblock_free_early_nid() manually.
5518 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5520 unsigned long start_pfn, end_pfn;
5523 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5524 start_pfn = min(start_pfn, max_low_pfn);
5525 end_pfn = min(end_pfn, max_low_pfn);
5527 if (start_pfn < end_pfn)
5528 memblock_free_early_nid(PFN_PHYS(start_pfn),
5529 (end_pfn - start_pfn) << PAGE_SHIFT,
5535 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5536 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5538 * If an architecture guarantees that all ranges registered contain no holes and may
5539 * be freed, this function may be used instead of calling memory_present() manually.
5541 void __init sparse_memory_present_with_active_regions(int nid)
5543 unsigned long start_pfn, end_pfn;
5546 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5547 memory_present(this_nid, start_pfn, end_pfn);
5551 * get_pfn_range_for_nid - Return the start and end page frames for a node
5552 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5553 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5554 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5556 * It returns the start and end page frame of a node based on information
5557 * provided by memblock_set_node(). If called for a node
5558 * with no available memory, a warning is printed and the start and end
5561 void __meminit get_pfn_range_for_nid(unsigned int nid,
5562 unsigned long *start_pfn, unsigned long *end_pfn)
5564 unsigned long this_start_pfn, this_end_pfn;
5570 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5571 *start_pfn = min(*start_pfn, this_start_pfn);
5572 *end_pfn = max(*end_pfn, this_end_pfn);
5575 if (*start_pfn == -1UL)
5580 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5581 * assumption is made that zones within a node are ordered in monotonic
5582 * increasing memory addresses so that the "highest" populated zone is used
5584 static void __init find_usable_zone_for_movable(void)
5587 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5588 if (zone_index == ZONE_MOVABLE)
5591 if (arch_zone_highest_possible_pfn[zone_index] >
5592 arch_zone_lowest_possible_pfn[zone_index])
5596 VM_BUG_ON(zone_index == -1);
5597 movable_zone = zone_index;
5601 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5602 * because it is sized independent of architecture. Unlike the other zones,
5603 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5604 * in each node depending on the size of each node and how evenly kernelcore
5605 * is distributed. This helper function adjusts the zone ranges
5606 * provided by the architecture for a given node by using the end of the
5607 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5608 * zones within a node are in order of monotonic increases memory addresses
5610 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5611 unsigned long zone_type,
5612 unsigned long node_start_pfn,
5613 unsigned long node_end_pfn,
5614 unsigned long *zone_start_pfn,
5615 unsigned long *zone_end_pfn)
5617 /* Only adjust if ZONE_MOVABLE is on this node */
5618 if (zone_movable_pfn[nid]) {
5619 /* Size ZONE_MOVABLE */
5620 if (zone_type == ZONE_MOVABLE) {
5621 *zone_start_pfn = zone_movable_pfn[nid];
5622 *zone_end_pfn = min(node_end_pfn,
5623 arch_zone_highest_possible_pfn[movable_zone]);
5625 /* Check if this whole range is within ZONE_MOVABLE */
5626 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5627 *zone_start_pfn = *zone_end_pfn;
5632 * Return the number of pages a zone spans in a node, including holes
5633 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5635 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5636 unsigned long zone_type,
5637 unsigned long node_start_pfn,
5638 unsigned long node_end_pfn,
5639 unsigned long *zone_start_pfn,
5640 unsigned long *zone_end_pfn,
5641 unsigned long *ignored)
5643 /* When hotadd a new node from cpu_up(), the node should be empty */
5644 if (!node_start_pfn && !node_end_pfn)
5647 /* Get the start and end of the zone */
5648 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5649 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5650 adjust_zone_range_for_zone_movable(nid, zone_type,
5651 node_start_pfn, node_end_pfn,
5652 zone_start_pfn, zone_end_pfn);
5654 /* Check that this node has pages within the zone's required range */
5655 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5658 /* Move the zone boundaries inside the node if necessary */
5659 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5660 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5662 /* Return the spanned pages */
5663 return *zone_end_pfn - *zone_start_pfn;
5667 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5668 * then all holes in the requested range will be accounted for.
5670 unsigned long __meminit __absent_pages_in_range(int nid,
5671 unsigned long range_start_pfn,
5672 unsigned long range_end_pfn)
5674 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5675 unsigned long start_pfn, end_pfn;
5678 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5679 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5680 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5681 nr_absent -= end_pfn - start_pfn;
5687 * absent_pages_in_range - Return number of page frames in holes within a range
5688 * @start_pfn: The start PFN to start searching for holes
5689 * @end_pfn: The end PFN to stop searching for holes
5691 * It returns the number of pages frames in memory holes within a range.
5693 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5694 unsigned long end_pfn)
5696 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5699 /* Return the number of page frames in holes in a zone on a node */
5700 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5701 unsigned long zone_type,
5702 unsigned long node_start_pfn,
5703 unsigned long node_end_pfn,
5704 unsigned long *ignored)
5706 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5707 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5708 unsigned long zone_start_pfn, zone_end_pfn;
5709 unsigned long nr_absent;
5711 /* When hotadd a new node from cpu_up(), the node should be empty */
5712 if (!node_start_pfn && !node_end_pfn)
5715 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5716 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5718 adjust_zone_range_for_zone_movable(nid, zone_type,
5719 node_start_pfn, node_end_pfn,
5720 &zone_start_pfn, &zone_end_pfn);
5721 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5724 * ZONE_MOVABLE handling.
5725 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5728 if (zone_movable_pfn[nid]) {
5729 if (mirrored_kernelcore) {
5730 unsigned long start_pfn, end_pfn;
5731 struct memblock_region *r;
5733 for_each_memblock(memory, r) {
5734 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5735 zone_start_pfn, zone_end_pfn);
5736 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5737 zone_start_pfn, zone_end_pfn);
5739 if (zone_type == ZONE_MOVABLE &&
5740 memblock_is_mirror(r))
5741 nr_absent += end_pfn - start_pfn;
5743 if (zone_type == ZONE_NORMAL &&
5744 !memblock_is_mirror(r))
5745 nr_absent += end_pfn - start_pfn;
5748 if (zone_type == ZONE_NORMAL)
5749 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5756 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5757 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5758 unsigned long zone_type,
5759 unsigned long node_start_pfn,
5760 unsigned long node_end_pfn,
5761 unsigned long *zone_start_pfn,
5762 unsigned long *zone_end_pfn,
5763 unsigned long *zones_size)
5767 *zone_start_pfn = node_start_pfn;
5768 for (zone = 0; zone < zone_type; zone++)
5769 *zone_start_pfn += zones_size[zone];
5771 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5773 return zones_size[zone_type];
5776 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5777 unsigned long zone_type,
5778 unsigned long node_start_pfn,
5779 unsigned long node_end_pfn,
5780 unsigned long *zholes_size)
5785 return zholes_size[zone_type];
5788 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5790 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5791 unsigned long node_start_pfn,
5792 unsigned long node_end_pfn,
5793 unsigned long *zones_size,
5794 unsigned long *zholes_size)
5796 unsigned long realtotalpages = 0, totalpages = 0;
5799 for (i = 0; i < MAX_NR_ZONES; i++) {
5800 struct zone *zone = pgdat->node_zones + i;
5801 unsigned long zone_start_pfn, zone_end_pfn;
5802 unsigned long size, real_size;
5804 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5810 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5811 node_start_pfn, node_end_pfn,
5814 zone->zone_start_pfn = zone_start_pfn;
5816 zone->zone_start_pfn = 0;
5817 zone->spanned_pages = size;
5818 zone->present_pages = real_size;
5821 realtotalpages += real_size;
5824 pgdat->node_spanned_pages = totalpages;
5825 pgdat->node_present_pages = realtotalpages;
5826 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5830 #ifndef CONFIG_SPARSEMEM
5832 * Calculate the size of the zone->blockflags rounded to an unsigned long
5833 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5834 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5835 * round what is now in bits to nearest long in bits, then return it in
5838 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5840 unsigned long usemapsize;
5842 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5843 usemapsize = roundup(zonesize, pageblock_nr_pages);
5844 usemapsize = usemapsize >> pageblock_order;
5845 usemapsize *= NR_PAGEBLOCK_BITS;
5846 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5848 return usemapsize / 8;
5851 static void __init setup_usemap(struct pglist_data *pgdat,
5853 unsigned long zone_start_pfn,
5854 unsigned long zonesize)
5856 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5857 zone->pageblock_flags = NULL;
5859 zone->pageblock_flags =
5860 memblock_virt_alloc_node_nopanic(usemapsize,
5864 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5865 unsigned long zone_start_pfn, unsigned long zonesize) {}
5866 #endif /* CONFIG_SPARSEMEM */
5868 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5870 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5871 void __paginginit set_pageblock_order(void)
5875 /* Check that pageblock_nr_pages has not already been setup */
5876 if (pageblock_order)
5879 if (HPAGE_SHIFT > PAGE_SHIFT)
5880 order = HUGETLB_PAGE_ORDER;
5882 order = MAX_ORDER - 1;
5885 * Assume the largest contiguous order of interest is a huge page.
5886 * This value may be variable depending on boot parameters on IA64 and
5889 pageblock_order = order;
5891 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5894 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5895 * is unused as pageblock_order is set at compile-time. See
5896 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5899 void __paginginit set_pageblock_order(void)
5903 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5905 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5906 unsigned long present_pages)
5908 unsigned long pages = spanned_pages;
5911 * Provide a more accurate estimation if there are holes within
5912 * the zone and SPARSEMEM is in use. If there are holes within the
5913 * zone, each populated memory region may cost us one or two extra
5914 * memmap pages due to alignment because memmap pages for each
5915 * populated regions may not naturally algined on page boundary.
5916 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5918 if (spanned_pages > present_pages + (present_pages >> 4) &&
5919 IS_ENABLED(CONFIG_SPARSEMEM))
5920 pages = present_pages;
5922 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5926 * Set up the zone data structures:
5927 * - mark all pages reserved
5928 * - mark all memory queues empty
5929 * - clear the memory bitmaps
5931 * NOTE: pgdat should get zeroed by caller.
5933 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5936 int nid = pgdat->node_id;
5939 pgdat_resize_init(pgdat);
5940 #ifdef CONFIG_NUMA_BALANCING
5941 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5942 pgdat->numabalancing_migrate_nr_pages = 0;
5943 pgdat->numabalancing_migrate_next_window = jiffies;
5945 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5946 spin_lock_init(&pgdat->split_queue_lock);
5947 INIT_LIST_HEAD(&pgdat->split_queue);
5948 pgdat->split_queue_len = 0;
5950 init_waitqueue_head(&pgdat->kswapd_wait);
5951 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5952 #ifdef CONFIG_COMPACTION
5953 init_waitqueue_head(&pgdat->kcompactd_wait);
5955 pgdat_page_ext_init(pgdat);
5957 for (j = 0; j < MAX_NR_ZONES; j++) {
5958 struct zone *zone = pgdat->node_zones + j;
5959 unsigned long size, realsize, freesize, memmap_pages;
5960 unsigned long zone_start_pfn = zone->zone_start_pfn;
5962 size = zone->spanned_pages;
5963 realsize = freesize = zone->present_pages;
5966 * Adjust freesize so that it accounts for how much memory
5967 * is used by this zone for memmap. This affects the watermark
5968 * and per-cpu initialisations
5970 memmap_pages = calc_memmap_size(size, realsize);
5971 if (!is_highmem_idx(j)) {
5972 if (freesize >= memmap_pages) {
5973 freesize -= memmap_pages;
5976 " %s zone: %lu pages used for memmap\n",
5977 zone_names[j], memmap_pages);
5979 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5980 zone_names[j], memmap_pages, freesize);
5983 /* Account for reserved pages */
5984 if (j == 0 && freesize > dma_reserve) {
5985 freesize -= dma_reserve;
5986 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5987 zone_names[0], dma_reserve);
5990 if (!is_highmem_idx(j))
5991 nr_kernel_pages += freesize;
5992 /* Charge for highmem memmap if there are enough kernel pages */
5993 else if (nr_kernel_pages > memmap_pages * 2)
5994 nr_kernel_pages -= memmap_pages;
5995 nr_all_pages += freesize;
5998 * Set an approximate value for lowmem here, it will be adjusted
5999 * when the bootmem allocator frees pages into the buddy system.
6000 * And all highmem pages will be managed by the buddy system.
6002 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
6005 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
6007 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
6009 zone->name = zone_names[j];
6010 spin_lock_init(&zone->lock);
6011 spin_lock_init(&zone->lru_lock);
6012 zone_seqlock_init(zone);
6013 zone->zone_pgdat = pgdat;
6014 zone_pcp_init(zone);
6016 /* For bootup, initialized properly in watermark setup */
6017 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
6019 lruvec_init(&zone->lruvec);
6023 set_pageblock_order();
6024 setup_usemap(pgdat, zone, zone_start_pfn, size);
6025 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
6027 memmap_init(size, nid, j, zone_start_pfn);
6031 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
6033 unsigned long __maybe_unused start = 0;
6034 unsigned long __maybe_unused offset = 0;
6036 /* Skip empty nodes */
6037 if (!pgdat->node_spanned_pages)
6040 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6041 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
6042 offset = pgdat->node_start_pfn - start;
6043 /* ia64 gets its own node_mem_map, before this, without bootmem */
6044 if (!pgdat->node_mem_map) {
6045 unsigned long size, end;
6049 * The zone's endpoints aren't required to be MAX_ORDER
6050 * aligned but the node_mem_map endpoints must be in order
6051 * for the buddy allocator to function correctly.
6053 end = pgdat_end_pfn(pgdat);
6054 end = ALIGN(end, MAX_ORDER_NR_PAGES);
6055 size = (end - start) * sizeof(struct page);
6056 map = alloc_remap(pgdat->node_id, size);
6058 map = memblock_virt_alloc_node_nopanic(size,
6060 pgdat->node_mem_map = map + offset;
6062 #ifndef CONFIG_NEED_MULTIPLE_NODES
6064 * With no DISCONTIG, the global mem_map is just set as node 0's
6066 if (pgdat == NODE_DATA(0)) {
6067 mem_map = NODE_DATA(0)->node_mem_map;
6068 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6069 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
6071 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6074 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6077 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
6078 unsigned long node_start_pfn, unsigned long *zholes_size)
6080 pg_data_t *pgdat = NODE_DATA(nid);
6081 unsigned long start_pfn = 0;
6082 unsigned long end_pfn = 0;
6084 /* pg_data_t should be reset to zero when it's allocated */
6085 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
6087 reset_deferred_meminit(pgdat);
6088 pgdat->node_id = nid;
6089 pgdat->node_start_pfn = node_start_pfn;
6090 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6091 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
6092 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
6093 (u64)start_pfn << PAGE_SHIFT,
6094 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
6096 start_pfn = node_start_pfn;
6098 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6099 zones_size, zholes_size);
6101 alloc_node_mem_map(pgdat);
6102 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6103 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6104 nid, (unsigned long)pgdat,
6105 (unsigned long)pgdat->node_mem_map);
6108 free_area_init_core(pgdat);
6111 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6113 #if MAX_NUMNODES > 1
6115 * Figure out the number of possible node ids.
6117 void __init setup_nr_node_ids(void)
6119 unsigned int highest;
6121 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
6122 nr_node_ids = highest + 1;
6127 * node_map_pfn_alignment - determine the maximum internode alignment
6129 * This function should be called after node map is populated and sorted.
6130 * It calculates the maximum power of two alignment which can distinguish
6133 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6134 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6135 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6136 * shifted, 1GiB is enough and this function will indicate so.
6138 * This is used to test whether pfn -> nid mapping of the chosen memory
6139 * model has fine enough granularity to avoid incorrect mapping for the
6140 * populated node map.
6142 * Returns the determined alignment in pfn's. 0 if there is no alignment
6143 * requirement (single node).
6145 unsigned long __init node_map_pfn_alignment(void)
6147 unsigned long accl_mask = 0, last_end = 0;
6148 unsigned long start, end, mask;
6152 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
6153 if (!start || last_nid < 0 || last_nid == nid) {
6160 * Start with a mask granular enough to pin-point to the
6161 * start pfn and tick off bits one-by-one until it becomes
6162 * too coarse to separate the current node from the last.
6164 mask = ~((1 << __ffs(start)) - 1);
6165 while (mask && last_end <= (start & (mask << 1)))
6168 /* accumulate all internode masks */
6172 /* convert mask to number of pages */
6173 return ~accl_mask + 1;
6176 /* Find the lowest pfn for a node */
6177 static unsigned long __init find_min_pfn_for_node(int nid)
6179 unsigned long min_pfn = ULONG_MAX;
6180 unsigned long start_pfn;
6183 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
6184 min_pfn = min(min_pfn, start_pfn);
6186 if (min_pfn == ULONG_MAX) {
6187 pr_warn("Could not find start_pfn for node %d\n", nid);
6195 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6197 * It returns the minimum PFN based on information provided via
6198 * memblock_set_node().
6200 unsigned long __init find_min_pfn_with_active_regions(void)
6202 return find_min_pfn_for_node(MAX_NUMNODES);
6206 * early_calculate_totalpages()
6207 * Sum pages in active regions for movable zone.
6208 * Populate N_MEMORY for calculating usable_nodes.
6210 static unsigned long __init early_calculate_totalpages(void)
6212 unsigned long totalpages = 0;
6213 unsigned long start_pfn, end_pfn;
6216 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6217 unsigned long pages = end_pfn - start_pfn;
6219 totalpages += pages;
6221 node_set_state(nid, N_MEMORY);
6227 * Find the PFN the Movable zone begins in each node. Kernel memory
6228 * is spread evenly between nodes as long as the nodes have enough
6229 * memory. When they don't, some nodes will have more kernelcore than
6232 static void __init find_zone_movable_pfns_for_nodes(void)
6235 unsigned long usable_startpfn;
6236 unsigned long kernelcore_node, kernelcore_remaining;
6237 /* save the state before borrow the nodemask */
6238 nodemask_t saved_node_state = node_states[N_MEMORY];
6239 unsigned long totalpages = early_calculate_totalpages();
6240 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6241 struct memblock_region *r;
6243 /* Need to find movable_zone earlier when movable_node is specified. */
6244 find_usable_zone_for_movable();
6247 * If movable_node is specified, ignore kernelcore and movablecore
6250 if (movable_node_is_enabled()) {
6251 for_each_memblock(memory, r) {
6252 if (!memblock_is_hotpluggable(r))
6257 usable_startpfn = PFN_DOWN(r->base);
6258 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6259 min(usable_startpfn, zone_movable_pfn[nid]) :
6267 * If kernelcore=mirror is specified, ignore movablecore option
6269 if (mirrored_kernelcore) {
6270 bool mem_below_4gb_not_mirrored = false;
6272 for_each_memblock(memory, r) {
6273 if (memblock_is_mirror(r))
6278 usable_startpfn = memblock_region_memory_base_pfn(r);
6280 if (usable_startpfn < 0x100000) {
6281 mem_below_4gb_not_mirrored = true;
6285 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6286 min(usable_startpfn, zone_movable_pfn[nid]) :
6290 if (mem_below_4gb_not_mirrored)
6291 pr_warn("This configuration results in unmirrored kernel memory.");
6297 * If movablecore=nn[KMG] was specified, calculate what size of
6298 * kernelcore that corresponds so that memory usable for
6299 * any allocation type is evenly spread. If both kernelcore
6300 * and movablecore are specified, then the value of kernelcore
6301 * will be used for required_kernelcore if it's greater than
6302 * what movablecore would have allowed.
6304 if (required_movablecore) {
6305 unsigned long corepages;
6308 * Round-up so that ZONE_MOVABLE is at least as large as what
6309 * was requested by the user
6311 required_movablecore =
6312 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6313 required_movablecore = min(totalpages, required_movablecore);
6314 corepages = totalpages - required_movablecore;
6316 required_kernelcore = max(required_kernelcore, corepages);
6320 * If kernelcore was not specified or kernelcore size is larger
6321 * than totalpages, there is no ZONE_MOVABLE.
6323 if (!required_kernelcore || required_kernelcore >= totalpages)
6326 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6327 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6330 /* Spread kernelcore memory as evenly as possible throughout nodes */
6331 kernelcore_node = required_kernelcore / usable_nodes;
6332 for_each_node_state(nid, N_MEMORY) {
6333 unsigned long start_pfn, end_pfn;
6336 * Recalculate kernelcore_node if the division per node
6337 * now exceeds what is necessary to satisfy the requested
6338 * amount of memory for the kernel
6340 if (required_kernelcore < kernelcore_node)
6341 kernelcore_node = required_kernelcore / usable_nodes;
6344 * As the map is walked, we track how much memory is usable
6345 * by the kernel using kernelcore_remaining. When it is
6346 * 0, the rest of the node is usable by ZONE_MOVABLE
6348 kernelcore_remaining = kernelcore_node;
6350 /* Go through each range of PFNs within this node */
6351 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6352 unsigned long size_pages;
6354 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6355 if (start_pfn >= end_pfn)
6358 /* Account for what is only usable for kernelcore */
6359 if (start_pfn < usable_startpfn) {
6360 unsigned long kernel_pages;
6361 kernel_pages = min(end_pfn, usable_startpfn)
6364 kernelcore_remaining -= min(kernel_pages,
6365 kernelcore_remaining);
6366 required_kernelcore -= min(kernel_pages,
6367 required_kernelcore);
6369 /* Continue if range is now fully accounted */
6370 if (end_pfn <= usable_startpfn) {
6373 * Push zone_movable_pfn to the end so
6374 * that if we have to rebalance
6375 * kernelcore across nodes, we will
6376 * not double account here
6378 zone_movable_pfn[nid] = end_pfn;
6381 start_pfn = usable_startpfn;
6385 * The usable PFN range for ZONE_MOVABLE is from
6386 * start_pfn->end_pfn. Calculate size_pages as the
6387 * number of pages used as kernelcore
6389 size_pages = end_pfn - start_pfn;
6390 if (size_pages > kernelcore_remaining)
6391 size_pages = kernelcore_remaining;
6392 zone_movable_pfn[nid] = start_pfn + size_pages;
6395 * Some kernelcore has been met, update counts and
6396 * break if the kernelcore for this node has been
6399 required_kernelcore -= min(required_kernelcore,
6401 kernelcore_remaining -= size_pages;
6402 if (!kernelcore_remaining)
6408 * If there is still required_kernelcore, we do another pass with one
6409 * less node in the count. This will push zone_movable_pfn[nid] further
6410 * along on the nodes that still have memory until kernelcore is
6414 if (usable_nodes && required_kernelcore > usable_nodes)
6418 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6419 for (nid = 0; nid < MAX_NUMNODES; nid++)
6420 zone_movable_pfn[nid] =
6421 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6424 /* restore the node_state */
6425 node_states[N_MEMORY] = saved_node_state;
6428 /* Any regular or high memory on that node ? */
6429 static void check_for_memory(pg_data_t *pgdat, int nid)
6431 enum zone_type zone_type;
6433 if (N_MEMORY == N_NORMAL_MEMORY)
6436 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6437 struct zone *zone = &pgdat->node_zones[zone_type];
6438 if (populated_zone(zone)) {
6439 node_set_state(nid, N_HIGH_MEMORY);
6440 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6441 zone_type <= ZONE_NORMAL)
6442 node_set_state(nid, N_NORMAL_MEMORY);
6449 * free_area_init_nodes - Initialise all pg_data_t and zone data
6450 * @max_zone_pfn: an array of max PFNs for each zone
6452 * This will call free_area_init_node() for each active node in the system.
6453 * Using the page ranges provided by memblock_set_node(), the size of each
6454 * zone in each node and their holes is calculated. If the maximum PFN
6455 * between two adjacent zones match, it is assumed that the zone is empty.
6456 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6457 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6458 * starts where the previous one ended. For example, ZONE_DMA32 starts
6459 * at arch_max_dma_pfn.
6461 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6463 unsigned long start_pfn, end_pfn;
6466 /* Record where the zone boundaries are */
6467 memset(arch_zone_lowest_possible_pfn, 0,
6468 sizeof(arch_zone_lowest_possible_pfn));
6469 memset(arch_zone_highest_possible_pfn, 0,
6470 sizeof(arch_zone_highest_possible_pfn));
6472 start_pfn = find_min_pfn_with_active_regions();
6474 for (i = 0; i < MAX_NR_ZONES; i++) {
6475 if (i == ZONE_MOVABLE)
6478 end_pfn = max(max_zone_pfn[i], start_pfn);
6479 arch_zone_lowest_possible_pfn[i] = start_pfn;
6480 arch_zone_highest_possible_pfn[i] = end_pfn;
6482 start_pfn = end_pfn;
6484 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6485 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6487 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6488 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6489 find_zone_movable_pfns_for_nodes();
6491 /* Print out the zone ranges */
6492 pr_info("Zone ranges:\n");
6493 for (i = 0; i < MAX_NR_ZONES; i++) {
6494 if (i == ZONE_MOVABLE)
6496 pr_info(" %-8s ", zone_names[i]);
6497 if (arch_zone_lowest_possible_pfn[i] ==
6498 arch_zone_highest_possible_pfn[i])
6501 pr_cont("[mem %#018Lx-%#018Lx]\n",
6502 (u64)arch_zone_lowest_possible_pfn[i]
6504 ((u64)arch_zone_highest_possible_pfn[i]
6505 << PAGE_SHIFT) - 1);
6508 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6509 pr_info("Movable zone start for each node\n");
6510 for (i = 0; i < MAX_NUMNODES; i++) {
6511 if (zone_movable_pfn[i])
6512 pr_info(" Node %d: %#018Lx\n", i,
6513 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6516 /* Print out the early node map */
6517 pr_info("Early memory node ranges\n");
6518 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6519 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6520 (u64)start_pfn << PAGE_SHIFT,
6521 ((u64)end_pfn << PAGE_SHIFT) - 1);
6523 /* Initialise every node */
6524 mminit_verify_pageflags_layout();
6525 setup_nr_node_ids();
6526 for_each_online_node(nid) {
6527 pg_data_t *pgdat = NODE_DATA(nid);
6528 free_area_init_node(nid, NULL,
6529 find_min_pfn_for_node(nid), NULL);
6531 /* Any memory on that node */
6532 if (pgdat->node_present_pages)
6533 node_set_state(nid, N_MEMORY);
6534 check_for_memory(pgdat, nid);
6538 static int __init cmdline_parse_core(char *p, unsigned long *core)
6540 unsigned long long coremem;
6544 coremem = memparse(p, &p);
6545 *core = coremem >> PAGE_SHIFT;
6547 /* Paranoid check that UL is enough for the coremem value */
6548 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6554 * kernelcore=size sets the amount of memory for use for allocations that
6555 * cannot be reclaimed or migrated.
6557 static int __init cmdline_parse_kernelcore(char *p)
6559 /* parse kernelcore=mirror */
6560 if (parse_option_str(p, "mirror")) {
6561 mirrored_kernelcore = true;
6565 return cmdline_parse_core(p, &required_kernelcore);
6569 * movablecore=size sets the amount of memory for use for allocations that
6570 * can be reclaimed or migrated.
6572 static int __init cmdline_parse_movablecore(char *p)
6574 return cmdline_parse_core(p, &required_movablecore);
6577 early_param("kernelcore", cmdline_parse_kernelcore);
6578 early_param("movablecore", cmdline_parse_movablecore);
6580 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6582 void adjust_managed_page_count(struct page *page, long count)
6584 spin_lock(&managed_page_count_lock);
6585 page_zone(page)->managed_pages += count;
6586 totalram_pages += count;
6587 #ifdef CONFIG_HIGHMEM
6588 if (PageHighMem(page))
6589 totalhigh_pages += count;
6591 spin_unlock(&managed_page_count_lock);
6593 EXPORT_SYMBOL(adjust_managed_page_count);
6595 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6598 unsigned long pages = 0;
6600 start = (void *)PAGE_ALIGN((unsigned long)start);
6601 end = (void *)((unsigned long)end & PAGE_MASK);
6602 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6603 if ((unsigned int)poison <= 0xFF)
6604 memset(pos, poison, PAGE_SIZE);
6605 free_reserved_page(virt_to_page(pos));
6609 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6610 s, pages << (PAGE_SHIFT - 10), start, end);
6614 EXPORT_SYMBOL(free_reserved_area);
6616 #ifdef CONFIG_HIGHMEM
6617 void free_highmem_page(struct page *page)
6619 __free_reserved_page(page);
6621 page_zone(page)->managed_pages++;
6627 void __init mem_init_print_info(const char *str)
6629 unsigned long physpages, codesize, datasize, rosize, bss_size;
6630 unsigned long init_code_size, init_data_size;
6632 physpages = get_num_physpages();
6633 codesize = _etext - _stext;
6634 datasize = _edata - _sdata;
6635 rosize = __end_rodata - __start_rodata;
6636 bss_size = __bss_stop - __bss_start;
6637 init_data_size = __init_end - __init_begin;
6638 init_code_size = _einittext - _sinittext;
6641 * Detect special cases and adjust section sizes accordingly:
6642 * 1) .init.* may be embedded into .data sections
6643 * 2) .init.text.* may be out of [__init_begin, __init_end],
6644 * please refer to arch/tile/kernel/vmlinux.lds.S.
6645 * 3) .rodata.* may be embedded into .text or .data sections.
6647 #define adj_init_size(start, end, size, pos, adj) \
6649 if (start <= pos && pos < end && size > adj) \
6653 adj_init_size(__init_begin, __init_end, init_data_size,
6654 _sinittext, init_code_size);
6655 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6656 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6657 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6658 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6660 #undef adj_init_size
6662 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6663 #ifdef CONFIG_HIGHMEM
6667 nr_free_pages() << (PAGE_SHIFT - 10),
6668 physpages << (PAGE_SHIFT - 10),
6669 codesize >> 10, datasize >> 10, rosize >> 10,
6670 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6671 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6672 totalcma_pages << (PAGE_SHIFT - 10),
6673 #ifdef CONFIG_HIGHMEM
6674 totalhigh_pages << (PAGE_SHIFT - 10),
6676 str ? ", " : "", str ? str : "");
6680 * set_dma_reserve - set the specified number of pages reserved in the first zone
6681 * @new_dma_reserve: The number of pages to mark reserved
6683 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6684 * In the DMA zone, a significant percentage may be consumed by kernel image
6685 * and other unfreeable allocations which can skew the watermarks badly. This
6686 * function may optionally be used to account for unfreeable pages in the
6687 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6688 * smaller per-cpu batchsize.
6690 void __init set_dma_reserve(unsigned long new_dma_reserve)
6692 dma_reserve = new_dma_reserve;
6695 void __init free_area_init(unsigned long *zones_size)
6697 free_area_init_node(0, zones_size,
6698 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6701 static int page_alloc_cpu_notify(struct notifier_block *self,
6702 unsigned long action, void *hcpu)
6704 int cpu = (unsigned long)hcpu;
6706 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6707 lru_add_drain_cpu(cpu);
6711 * Spill the event counters of the dead processor
6712 * into the current processors event counters.
6713 * This artificially elevates the count of the current
6716 vm_events_fold_cpu(cpu);
6719 * Zero the differential counters of the dead processor
6720 * so that the vm statistics are consistent.
6722 * This is only okay since the processor is dead and cannot
6723 * race with what we are doing.
6725 cpu_vm_stats_fold(cpu);
6730 void __init page_alloc_init(void)
6732 hotcpu_notifier(page_alloc_cpu_notify, 0);
6736 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6737 * or min_free_kbytes changes.
6739 static void calculate_totalreserve_pages(void)
6741 struct pglist_data *pgdat;
6742 unsigned long reserve_pages = 0;
6743 enum zone_type i, j;
6745 for_each_online_pgdat(pgdat) {
6746 for (i = 0; i < MAX_NR_ZONES; i++) {
6747 struct zone *zone = pgdat->node_zones + i;
6750 /* Find valid and maximum lowmem_reserve in the zone */
6751 for (j = i; j < MAX_NR_ZONES; j++) {
6752 if (zone->lowmem_reserve[j] > max)
6753 max = zone->lowmem_reserve[j];
6756 /* we treat the high watermark as reserved pages. */
6757 max += high_wmark_pages(zone);
6759 if (max > zone->managed_pages)
6760 max = zone->managed_pages;
6762 zone->totalreserve_pages = max;
6764 reserve_pages += max;
6767 totalreserve_pages = reserve_pages;
6771 * setup_per_zone_lowmem_reserve - called whenever
6772 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6773 * has a correct pages reserved value, so an adequate number of
6774 * pages are left in the zone after a successful __alloc_pages().
6776 static void setup_per_zone_lowmem_reserve(void)
6778 struct pglist_data *pgdat;
6779 enum zone_type j, idx;
6781 for_each_online_pgdat(pgdat) {
6782 for (j = 0; j < MAX_NR_ZONES; j++) {
6783 struct zone *zone = pgdat->node_zones + j;
6784 unsigned long managed_pages = zone->managed_pages;
6786 zone->lowmem_reserve[j] = 0;
6790 struct zone *lower_zone;
6794 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6795 sysctl_lowmem_reserve_ratio[idx] = 1;
6797 lower_zone = pgdat->node_zones + idx;
6798 lower_zone->lowmem_reserve[j] = managed_pages /
6799 sysctl_lowmem_reserve_ratio[idx];
6800 managed_pages += lower_zone->managed_pages;
6805 /* update totalreserve_pages */
6806 calculate_totalreserve_pages();
6809 static void __setup_per_zone_wmarks(void)
6811 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6812 unsigned long lowmem_pages = 0;
6814 unsigned long flags;
6816 /* Calculate total number of !ZONE_HIGHMEM pages */
6817 for_each_zone(zone) {
6818 if (!is_highmem(zone))
6819 lowmem_pages += zone->managed_pages;
6822 for_each_zone(zone) {
6825 spin_lock_irqsave(&zone->lock, flags);
6826 tmp = (u64)pages_min * zone->managed_pages;
6827 do_div(tmp, lowmem_pages);
6828 if (is_highmem(zone)) {
6830 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6831 * need highmem pages, so cap pages_min to a small
6834 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6835 * deltas control asynch page reclaim, and so should
6836 * not be capped for highmem.
6838 unsigned long min_pages;
6840 min_pages = zone->managed_pages / 1024;
6841 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6842 zone->watermark[WMARK_MIN] = min_pages;
6845 * If it's a lowmem zone, reserve a number of pages
6846 * proportionate to the zone's size.
6848 zone->watermark[WMARK_MIN] = tmp;
6852 * Set the kswapd watermarks distance according to the
6853 * scale factor in proportion to available memory, but
6854 * ensure a minimum size on small systems.
6856 tmp = max_t(u64, tmp >> 2,
6857 mult_frac(zone->managed_pages,
6858 watermark_scale_factor, 10000));
6860 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6861 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6863 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6864 high_wmark_pages(zone) - low_wmark_pages(zone) -
6865 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6867 spin_unlock_irqrestore(&zone->lock, flags);
6870 /* update totalreserve_pages */
6871 calculate_totalreserve_pages();
6875 * setup_per_zone_wmarks - called when min_free_kbytes changes
6876 * or when memory is hot-{added|removed}
6878 * Ensures that the watermark[min,low,high] values for each zone are set
6879 * correctly with respect to min_free_kbytes.
6881 void setup_per_zone_wmarks(void)
6883 mutex_lock(&zonelists_mutex);
6884 __setup_per_zone_wmarks();
6885 mutex_unlock(&zonelists_mutex);
6889 * Initialise min_free_kbytes.
6891 * For small machines we want it small (128k min). For large machines
6892 * we want it large (64MB max). But it is not linear, because network
6893 * bandwidth does not increase linearly with machine size. We use
6895 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6896 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6912 int __meminit init_per_zone_wmark_min(void)
6914 unsigned long lowmem_kbytes;
6915 int new_min_free_kbytes;
6917 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6918 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6920 if (new_min_free_kbytes > user_min_free_kbytes) {
6921 min_free_kbytes = new_min_free_kbytes;
6922 if (min_free_kbytes < 128)
6923 min_free_kbytes = 128;
6924 if (min_free_kbytes > 65536)
6925 min_free_kbytes = 65536;
6927 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6928 new_min_free_kbytes, user_min_free_kbytes);
6930 setup_per_zone_wmarks();
6931 refresh_zone_stat_thresholds();
6932 setup_per_zone_lowmem_reserve();
6935 core_initcall(init_per_zone_wmark_min)
6938 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6939 * that we can call two helper functions whenever min_free_kbytes
6942 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6943 void __user *buffer, size_t *length, loff_t *ppos)
6947 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6952 user_min_free_kbytes = min_free_kbytes;
6953 setup_per_zone_wmarks();
6958 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6959 void __user *buffer, size_t *length, loff_t *ppos)
6963 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6968 setup_per_zone_wmarks();
6974 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6975 void __user *buffer, size_t *length, loff_t *ppos)
6980 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6985 zone->min_unmapped_pages = (zone->managed_pages *
6986 sysctl_min_unmapped_ratio) / 100;
6990 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6991 void __user *buffer, size_t *length, loff_t *ppos)
6996 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
7001 zone->min_slab_pages = (zone->managed_pages *
7002 sysctl_min_slab_ratio) / 100;
7008 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7009 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7010 * whenever sysctl_lowmem_reserve_ratio changes.
7012 * The reserve ratio obviously has absolutely no relation with the
7013 * minimum watermarks. The lowmem reserve ratio can only make sense
7014 * if in function of the boot time zone sizes.
7016 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
7017 void __user *buffer, size_t *length, loff_t *ppos)
7019 proc_dointvec_minmax(table, write, buffer, length, ppos);
7020 setup_per_zone_lowmem_reserve();
7025 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7026 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7027 * pagelist can have before it gets flushed back to buddy allocator.
7029 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
7030 void __user *buffer, size_t *length, loff_t *ppos)
7033 int old_percpu_pagelist_fraction;
7036 mutex_lock(&pcp_batch_high_lock);
7037 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
7039 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
7040 if (!write || ret < 0)
7043 /* Sanity checking to avoid pcp imbalance */
7044 if (percpu_pagelist_fraction &&
7045 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
7046 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
7052 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
7055 for_each_populated_zone(zone) {
7058 for_each_possible_cpu(cpu)
7059 pageset_set_high_and_batch(zone,
7060 per_cpu_ptr(zone->pageset, cpu));
7063 mutex_unlock(&pcp_batch_high_lock);
7068 int hashdist = HASHDIST_DEFAULT;
7070 static int __init set_hashdist(char *str)
7074 hashdist = simple_strtoul(str, &str, 0);
7077 __setup("hashdist=", set_hashdist);
7081 * allocate a large system hash table from bootmem
7082 * - it is assumed that the hash table must contain an exact power-of-2
7083 * quantity of entries
7084 * - limit is the number of hash buckets, not the total allocation size
7086 void *__init alloc_large_system_hash(const char *tablename,
7087 unsigned long bucketsize,
7088 unsigned long numentries,
7091 unsigned int *_hash_shift,
7092 unsigned int *_hash_mask,
7093 unsigned long low_limit,
7094 unsigned long high_limit)
7096 unsigned long long max = high_limit;
7097 unsigned long log2qty, size;
7100 /* allow the kernel cmdline to have a say */
7102 /* round applicable memory size up to nearest megabyte */
7103 numentries = nr_kernel_pages;
7105 /* It isn't necessary when PAGE_SIZE >= 1MB */
7106 if (PAGE_SHIFT < 20)
7107 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
7109 /* limit to 1 bucket per 2^scale bytes of low memory */
7110 if (scale > PAGE_SHIFT)
7111 numentries >>= (scale - PAGE_SHIFT);
7113 numentries <<= (PAGE_SHIFT - scale);
7115 /* Make sure we've got at least a 0-order allocation.. */
7116 if (unlikely(flags & HASH_SMALL)) {
7117 /* Makes no sense without HASH_EARLY */
7118 WARN_ON(!(flags & HASH_EARLY));
7119 if (!(numentries >> *_hash_shift)) {
7120 numentries = 1UL << *_hash_shift;
7121 BUG_ON(!numentries);
7123 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
7124 numentries = PAGE_SIZE / bucketsize;
7126 numentries = roundup_pow_of_two(numentries);
7128 /* limit allocation size to 1/16 total memory by default */
7130 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
7131 do_div(max, bucketsize);
7133 max = min(max, 0x80000000ULL);
7135 if (numentries < low_limit)
7136 numentries = low_limit;
7137 if (numentries > max)
7140 log2qty = ilog2(numentries);
7143 size = bucketsize << log2qty;
7144 if (flags & HASH_EARLY)
7145 table = memblock_virt_alloc_nopanic(size, 0);
7147 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
7150 * If bucketsize is not a power-of-two, we may free
7151 * some pages at the end of hash table which
7152 * alloc_pages_exact() automatically does
7154 if (get_order(size) < MAX_ORDER) {
7155 table = alloc_pages_exact(size, GFP_ATOMIC);
7156 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
7159 } while (!table && size > PAGE_SIZE && --log2qty);
7162 panic("Failed to allocate %s hash table\n", tablename);
7164 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7165 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7168 *_hash_shift = log2qty;
7170 *_hash_mask = (1 << log2qty) - 1;
7176 * This function checks whether pageblock includes unmovable pages or not.
7177 * If @count is not zero, it is okay to include less @count unmovable pages
7179 * PageLRU check without isolation or lru_lock could race so that
7180 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7181 * expect this function should be exact.
7183 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7184 bool skip_hwpoisoned_pages)
7186 unsigned long pfn, iter, found;
7190 * For avoiding noise data, lru_add_drain_all() should be called
7191 * If ZONE_MOVABLE, the zone never contains unmovable pages
7193 if (zone_idx(zone) == ZONE_MOVABLE)
7195 mt = get_pageblock_migratetype(page);
7196 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
7199 pfn = page_to_pfn(page);
7200 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7201 unsigned long check = pfn + iter;
7203 if (!pfn_valid_within(check))
7206 page = pfn_to_page(check);
7209 * Hugepages are not in LRU lists, but they're movable.
7210 * We need not scan over tail pages bacause we don't
7211 * handle each tail page individually in migration.
7213 if (PageHuge(page)) {
7214 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7219 * We can't use page_count without pin a page
7220 * because another CPU can free compound page.
7221 * This check already skips compound tails of THP
7222 * because their page->_refcount is zero at all time.
7224 if (!page_ref_count(page)) {
7225 if (PageBuddy(page))
7226 iter += (1 << page_order(page)) - 1;
7231 * The HWPoisoned page may be not in buddy system, and
7232 * page_count() is not 0.
7234 if (skip_hwpoisoned_pages && PageHWPoison(page))
7240 * If there are RECLAIMABLE pages, we need to check
7241 * it. But now, memory offline itself doesn't call
7242 * shrink_node_slabs() and it still to be fixed.
7245 * If the page is not RAM, page_count()should be 0.
7246 * we don't need more check. This is an _used_ not-movable page.
7248 * The problematic thing here is PG_reserved pages. PG_reserved
7249 * is set to both of a memory hole page and a _used_ kernel
7258 bool is_pageblock_removable_nolock(struct page *page)
7264 * We have to be careful here because we are iterating over memory
7265 * sections which are not zone aware so we might end up outside of
7266 * the zone but still within the section.
7267 * We have to take care about the node as well. If the node is offline
7268 * its NODE_DATA will be NULL - see page_zone.
7270 if (!node_online(page_to_nid(page)))
7273 zone = page_zone(page);
7274 pfn = page_to_pfn(page);
7275 if (!zone_spans_pfn(zone, pfn))
7278 return !has_unmovable_pages(zone, page, 0, true);
7281 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7283 static unsigned long pfn_max_align_down(unsigned long pfn)
7285 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7286 pageblock_nr_pages) - 1);
7289 static unsigned long pfn_max_align_up(unsigned long pfn)
7291 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7292 pageblock_nr_pages));
7295 /* [start, end) must belong to a single zone. */
7296 static int __alloc_contig_migrate_range(struct compact_control *cc,
7297 unsigned long start, unsigned long end)
7299 /* This function is based on compact_zone() from compaction.c. */
7300 unsigned long nr_reclaimed;
7301 unsigned long pfn = start;
7302 unsigned int tries = 0;
7307 while (pfn < end || !list_empty(&cc->migratepages)) {
7308 if (fatal_signal_pending(current)) {
7313 if (list_empty(&cc->migratepages)) {
7314 cc->nr_migratepages = 0;
7315 pfn = isolate_migratepages_range(cc, pfn, end);
7321 } else if (++tries == 5) {
7322 ret = ret < 0 ? ret : -EBUSY;
7326 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7328 cc->nr_migratepages -= nr_reclaimed;
7330 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7331 NULL, 0, cc->mode, MR_CMA);
7334 putback_movable_pages(&cc->migratepages);
7341 * alloc_contig_range() -- tries to allocate given range of pages
7342 * @start: start PFN to allocate
7343 * @end: one-past-the-last PFN to allocate
7344 * @migratetype: migratetype of the underlaying pageblocks (either
7345 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7346 * in range must have the same migratetype and it must
7347 * be either of the two.
7349 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7350 * aligned, however it's the caller's responsibility to guarantee that
7351 * we are the only thread that changes migrate type of pageblocks the
7354 * The PFN range must belong to a single zone.
7356 * Returns zero on success or negative error code. On success all
7357 * pages which PFN is in [start, end) are allocated for the caller and
7358 * need to be freed with free_contig_range().
7360 int alloc_contig_range(unsigned long start, unsigned long end,
7361 unsigned migratetype)
7363 unsigned long outer_start, outer_end;
7367 struct compact_control cc = {
7368 .nr_migratepages = 0,
7370 .zone = page_zone(pfn_to_page(start)),
7371 .mode = MIGRATE_SYNC,
7372 .ignore_skip_hint = true,
7374 INIT_LIST_HEAD(&cc.migratepages);
7377 * What we do here is we mark all pageblocks in range as
7378 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7379 * have different sizes, and due to the way page allocator
7380 * work, we align the range to biggest of the two pages so
7381 * that page allocator won't try to merge buddies from
7382 * different pageblocks and change MIGRATE_ISOLATE to some
7383 * other migration type.
7385 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7386 * migrate the pages from an unaligned range (ie. pages that
7387 * we are interested in). This will put all the pages in
7388 * range back to page allocator as MIGRATE_ISOLATE.
7390 * When this is done, we take the pages in range from page
7391 * allocator removing them from the buddy system. This way
7392 * page allocator will never consider using them.
7394 * This lets us mark the pageblocks back as
7395 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7396 * aligned range but not in the unaligned, original range are
7397 * put back to page allocator so that buddy can use them.
7400 ret = start_isolate_page_range(pfn_max_align_down(start),
7401 pfn_max_align_up(end), migratetype,
7407 * In case of -EBUSY, we'd like to know which page causes problem.
7408 * So, just fall through. We will check it in test_pages_isolated().
7410 ret = __alloc_contig_migrate_range(&cc, start, end);
7411 if (ret && ret != -EBUSY)
7415 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7416 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7417 * more, all pages in [start, end) are free in page allocator.
7418 * What we are going to do is to allocate all pages from
7419 * [start, end) (that is remove them from page allocator).
7421 * The only problem is that pages at the beginning and at the
7422 * end of interesting range may be not aligned with pages that
7423 * page allocator holds, ie. they can be part of higher order
7424 * pages. Because of this, we reserve the bigger range and
7425 * once this is done free the pages we are not interested in.
7427 * We don't have to hold zone->lock here because the pages are
7428 * isolated thus they won't get removed from buddy.
7431 lru_add_drain_all();
7432 drain_all_pages(cc.zone);
7435 outer_start = start;
7436 while (!PageBuddy(pfn_to_page(outer_start))) {
7437 if (++order >= MAX_ORDER) {
7438 outer_start = start;
7441 outer_start &= ~0UL << order;
7444 if (outer_start != start) {
7445 order = page_order(pfn_to_page(outer_start));
7448 * outer_start page could be small order buddy page and
7449 * it doesn't include start page. Adjust outer_start
7450 * in this case to report failed page properly
7451 * on tracepoint in test_pages_isolated()
7453 if (outer_start + (1UL << order) <= start)
7454 outer_start = start;
7457 /* Make sure the range is really isolated. */
7458 if (test_pages_isolated(outer_start, end, false)) {
7459 pr_info("%s: [%lx, %lx) PFNs busy\n",
7460 __func__, outer_start, end);
7465 /* Grab isolated pages from freelists. */
7466 outer_end = isolate_freepages_range(&cc, outer_start, end);
7472 /* Free head and tail (if any) */
7473 if (start != outer_start)
7474 free_contig_range(outer_start, start - outer_start);
7475 if (end != outer_end)
7476 free_contig_range(end, outer_end - end);
7479 undo_isolate_page_range(pfn_max_align_down(start),
7480 pfn_max_align_up(end), migratetype);
7484 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7486 unsigned int count = 0;
7488 for (; nr_pages--; pfn++) {
7489 struct page *page = pfn_to_page(pfn);
7491 count += page_count(page) != 1;
7494 WARN(count != 0, "%d pages are still in use!\n", count);
7498 #ifdef CONFIG_MEMORY_HOTPLUG
7500 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7501 * page high values need to be recalulated.
7503 void __meminit zone_pcp_update(struct zone *zone)
7506 mutex_lock(&pcp_batch_high_lock);
7507 for_each_possible_cpu(cpu)
7508 pageset_set_high_and_batch(zone,
7509 per_cpu_ptr(zone->pageset, cpu));
7510 mutex_unlock(&pcp_batch_high_lock);
7514 void zone_pcp_reset(struct zone *zone)
7516 unsigned long flags;
7518 struct per_cpu_pageset *pset;
7520 /* avoid races with drain_pages() */
7521 local_irq_save(flags);
7522 if (zone->pageset != &boot_pageset) {
7523 for_each_online_cpu(cpu) {
7524 pset = per_cpu_ptr(zone->pageset, cpu);
7525 drain_zonestat(zone, pset);
7527 free_percpu(zone->pageset);
7528 zone->pageset = &boot_pageset;
7530 local_irq_restore(flags);
7533 #ifdef CONFIG_MEMORY_HOTREMOVE
7535 * All pages in the range must be in a single zone and isolated
7536 * before calling this.
7539 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7543 unsigned int order, i;
7545 unsigned long flags;
7546 /* find the first valid pfn */
7547 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7552 zone = page_zone(pfn_to_page(pfn));
7553 spin_lock_irqsave(&zone->lock, flags);
7555 while (pfn < end_pfn) {
7556 if (!pfn_valid(pfn)) {
7560 page = pfn_to_page(pfn);
7562 * The HWPoisoned page may be not in buddy system, and
7563 * page_count() is not 0.
7565 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7567 SetPageReserved(page);
7571 BUG_ON(page_count(page));
7572 BUG_ON(!PageBuddy(page));
7573 order = page_order(page);
7574 #ifdef CONFIG_DEBUG_VM
7575 pr_info("remove from free list %lx %d %lx\n",
7576 pfn, 1 << order, end_pfn);
7578 list_del(&page->lru);
7579 rmv_page_order(page);
7580 zone->free_area[order].nr_free--;
7581 for (i = 0; i < (1 << order); i++)
7582 SetPageReserved((page+i));
7583 pfn += (1 << order);
7585 spin_unlock_irqrestore(&zone->lock, flags);
7589 bool is_free_buddy_page(struct page *page)
7591 struct zone *zone = page_zone(page);
7592 unsigned long pfn = page_to_pfn(page);
7593 unsigned long flags;
7596 spin_lock_irqsave(&zone->lock, flags);
7597 for (order = 0; order < MAX_ORDER; order++) {
7598 struct page *page_head = page - (pfn & ((1 << order) - 1));
7600 if (PageBuddy(page_head) && page_order(page_head) >= order)
7603 spin_unlock_irqrestore(&zone->lock, flags);
7605 return order < MAX_ORDER;