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 if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn)
295 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
297 if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
304 * Returns false when the remaining initialisation should be deferred until
305 * later in the boot cycle when it can be parallelised.
307 static inline bool update_defer_init(pg_data_t *pgdat,
308 unsigned long pfn, unsigned long zone_end,
309 unsigned long *nr_initialised)
311 /* Always populate low zones for address-contrained allocations */
312 if (zone_end < pgdat_end_pfn(pgdat))
315 /* Initialise at least 2G of the highest zone */
317 if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) &&
318 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
319 pgdat->first_deferred_pfn = pfn;
326 static inline void reset_deferred_meminit(pg_data_t *pgdat)
330 static inline bool early_page_uninitialised(unsigned long pfn)
335 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
340 static inline bool update_defer_init(pg_data_t *pgdat,
341 unsigned long pfn, unsigned long zone_end,
342 unsigned long *nr_initialised)
349 void set_pageblock_migratetype(struct page *page, int migratetype)
351 if (unlikely(page_group_by_mobility_disabled &&
352 migratetype < MIGRATE_PCPTYPES))
353 migratetype = MIGRATE_UNMOVABLE;
355 set_pageblock_flags_group(page, (unsigned long)migratetype,
356 PB_migrate, PB_migrate_end);
359 #ifdef CONFIG_DEBUG_VM
360 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
364 unsigned long pfn = page_to_pfn(page);
365 unsigned long sp, start_pfn;
368 seq = zone_span_seqbegin(zone);
369 start_pfn = zone->zone_start_pfn;
370 sp = zone->spanned_pages;
371 if (!zone_spans_pfn(zone, pfn))
373 } while (zone_span_seqretry(zone, seq));
376 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
377 pfn, zone_to_nid(zone), zone->name,
378 start_pfn, start_pfn + sp);
383 static int page_is_consistent(struct zone *zone, struct page *page)
385 if (!pfn_valid_within(page_to_pfn(page)))
387 if (zone != page_zone(page))
393 * Temporary debugging check for pages not lying within a given zone.
395 static int bad_range(struct zone *zone, struct page *page)
397 if (page_outside_zone_boundaries(zone, page))
399 if (!page_is_consistent(zone, page))
405 static inline int bad_range(struct zone *zone, struct page *page)
411 static void bad_page(struct page *page, const char *reason,
412 unsigned long bad_flags)
414 static unsigned long resume;
415 static unsigned long nr_shown;
416 static unsigned long nr_unshown;
418 /* Don't complain about poisoned pages */
419 if (PageHWPoison(page)) {
420 page_mapcount_reset(page); /* remove PageBuddy */
425 * Allow a burst of 60 reports, then keep quiet for that minute;
426 * or allow a steady drip of one report per second.
428 if (nr_shown == 60) {
429 if (time_before(jiffies, resume)) {
435 "BUG: Bad page state: %lu messages suppressed\n",
442 resume = jiffies + 60 * HZ;
444 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
445 current->comm, page_to_pfn(page));
446 __dump_page(page, reason);
447 bad_flags &= page->flags;
449 pr_alert("bad because of flags: %#lx(%pGp)\n",
450 bad_flags, &bad_flags);
451 dump_page_owner(page);
456 /* Leave bad fields for debug, except PageBuddy could make trouble */
457 page_mapcount_reset(page); /* remove PageBuddy */
458 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
462 * Higher-order pages are called "compound pages". They are structured thusly:
464 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
466 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
467 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
469 * The first tail page's ->compound_dtor holds the offset in array of compound
470 * page destructors. See compound_page_dtors.
472 * The first tail page's ->compound_order holds the order of allocation.
473 * This usage means that zero-order pages may not be compound.
476 void free_compound_page(struct page *page)
478 __free_pages_ok(page, compound_order(page));
481 void prep_compound_page(struct page *page, unsigned int order)
484 int nr_pages = 1 << order;
486 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
487 set_compound_order(page, order);
489 for (i = 1; i < nr_pages; i++) {
490 struct page *p = page + i;
491 set_page_count(p, 0);
492 p->mapping = TAIL_MAPPING;
493 set_compound_head(p, page);
495 atomic_set(compound_mapcount_ptr(page), -1);
498 #ifdef CONFIG_DEBUG_PAGEALLOC
499 unsigned int _debug_guardpage_minorder;
500 bool _debug_pagealloc_enabled __read_mostly
501 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
502 EXPORT_SYMBOL(_debug_pagealloc_enabled);
503 bool _debug_guardpage_enabled __read_mostly;
505 static int __init early_debug_pagealloc(char *buf)
510 if (strcmp(buf, "on") == 0)
511 _debug_pagealloc_enabled = true;
513 if (strcmp(buf, "off") == 0)
514 _debug_pagealloc_enabled = false;
518 early_param("debug_pagealloc", early_debug_pagealloc);
520 static bool need_debug_guardpage(void)
522 /* If we don't use debug_pagealloc, we don't need guard page */
523 if (!debug_pagealloc_enabled())
529 static void init_debug_guardpage(void)
531 if (!debug_pagealloc_enabled())
534 _debug_guardpage_enabled = true;
537 struct page_ext_operations debug_guardpage_ops = {
538 .need = need_debug_guardpage,
539 .init = init_debug_guardpage,
542 static int __init debug_guardpage_minorder_setup(char *buf)
546 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
547 pr_err("Bad debug_guardpage_minorder value\n");
550 _debug_guardpage_minorder = res;
551 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
554 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
556 static inline void set_page_guard(struct zone *zone, struct page *page,
557 unsigned int order, int migratetype)
559 struct page_ext *page_ext;
561 if (!debug_guardpage_enabled())
564 page_ext = lookup_page_ext(page);
565 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
567 INIT_LIST_HEAD(&page->lru);
568 set_page_private(page, order);
569 /* Guard pages are not available for any usage */
570 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
573 static inline void clear_page_guard(struct zone *zone, struct page *page,
574 unsigned int order, int migratetype)
576 struct page_ext *page_ext;
578 if (!debug_guardpage_enabled())
581 page_ext = lookup_page_ext(page);
582 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
584 set_page_private(page, 0);
585 if (!is_migrate_isolate(migratetype))
586 __mod_zone_freepage_state(zone, (1 << order), migratetype);
589 struct page_ext_operations debug_guardpage_ops = { NULL, };
590 static inline void set_page_guard(struct zone *zone, struct page *page,
591 unsigned int order, int migratetype) {}
592 static inline void clear_page_guard(struct zone *zone, struct page *page,
593 unsigned int order, int migratetype) {}
596 static inline void set_page_order(struct page *page, unsigned int order)
598 set_page_private(page, order);
599 __SetPageBuddy(page);
602 static inline void rmv_page_order(struct page *page)
604 __ClearPageBuddy(page);
605 set_page_private(page, 0);
609 * This function checks whether a page is free && is the buddy
610 * we can do coalesce a page and its buddy if
611 * (a) the buddy is not in a hole &&
612 * (b) the buddy is in the buddy system &&
613 * (c) a page and its buddy have the same order &&
614 * (d) a page and its buddy are in the same zone.
616 * For recording whether a page is in the buddy system, we set ->_mapcount
617 * PAGE_BUDDY_MAPCOUNT_VALUE.
618 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
619 * serialized by zone->lock.
621 * For recording page's order, we use page_private(page).
623 static inline int page_is_buddy(struct page *page, struct page *buddy,
626 if (!pfn_valid_within(page_to_pfn(buddy)))
629 if (page_is_guard(buddy) && page_order(buddy) == order) {
630 if (page_zone_id(page) != page_zone_id(buddy))
633 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
638 if (PageBuddy(buddy) && page_order(buddy) == order) {
640 * zone check is done late to avoid uselessly
641 * calculating zone/node ids for pages that could
644 if (page_zone_id(page) != page_zone_id(buddy))
647 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
655 * Freeing function for a buddy system allocator.
657 * The concept of a buddy system is to maintain direct-mapped table
658 * (containing bit values) for memory blocks of various "orders".
659 * The bottom level table contains the map for the smallest allocatable
660 * units of memory (here, pages), and each level above it describes
661 * pairs of units from the levels below, hence, "buddies".
662 * At a high level, all that happens here is marking the table entry
663 * at the bottom level available, and propagating the changes upward
664 * as necessary, plus some accounting needed to play nicely with other
665 * parts of the VM system.
666 * At each level, we keep a list of pages, which are heads of continuous
667 * free pages of length of (1 << order) and marked with _mapcount
668 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
670 * So when we are allocating or freeing one, we can derive the state of the
671 * other. That is, if we allocate a small block, and both were
672 * free, the remainder of the region must be split into blocks.
673 * If a block is freed, and its buddy is also free, then this
674 * triggers coalescing into a block of larger size.
679 static inline void __free_one_page(struct page *page,
681 struct zone *zone, unsigned int order,
684 unsigned long page_idx;
685 unsigned long combined_idx;
686 unsigned long uninitialized_var(buddy_idx);
688 unsigned int max_order = MAX_ORDER;
690 VM_BUG_ON(!zone_is_initialized(zone));
691 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
693 VM_BUG_ON(migratetype == -1);
694 if (is_migrate_isolate(migratetype)) {
696 * We restrict max order of merging to prevent merge
697 * between freepages on isolate pageblock and normal
698 * pageblock. Without this, pageblock isolation
699 * could cause incorrect freepage accounting.
701 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
703 __mod_zone_freepage_state(zone, 1 << order, migratetype);
706 page_idx = pfn & ((1 << max_order) - 1);
708 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
709 VM_BUG_ON_PAGE(bad_range(zone, page), page);
711 while (order < max_order - 1) {
712 buddy_idx = __find_buddy_index(page_idx, order);
713 buddy = page + (buddy_idx - page_idx);
714 if (!page_is_buddy(page, buddy, order))
717 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
718 * merge with it and move up one order.
720 if (page_is_guard(buddy)) {
721 clear_page_guard(zone, buddy, order, migratetype);
723 list_del(&buddy->lru);
724 zone->free_area[order].nr_free--;
725 rmv_page_order(buddy);
727 combined_idx = buddy_idx & page_idx;
728 page = page + (combined_idx - page_idx);
729 page_idx = combined_idx;
732 set_page_order(page, order);
735 * If this is not the largest possible page, check if the buddy
736 * of the next-highest order is free. If it is, it's possible
737 * that pages are being freed that will coalesce soon. In case,
738 * that is happening, add the free page to the tail of the list
739 * so it's less likely to be used soon and more likely to be merged
740 * as a higher order page
742 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
743 struct page *higher_page, *higher_buddy;
744 combined_idx = buddy_idx & page_idx;
745 higher_page = page + (combined_idx - page_idx);
746 buddy_idx = __find_buddy_index(combined_idx, order + 1);
747 higher_buddy = higher_page + (buddy_idx - combined_idx);
748 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
749 list_add_tail(&page->lru,
750 &zone->free_area[order].free_list[migratetype]);
755 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
757 zone->free_area[order].nr_free++;
760 static inline int free_pages_check(struct page *page)
762 const char *bad_reason = NULL;
763 unsigned long bad_flags = 0;
765 if (unlikely(atomic_read(&page->_mapcount) != -1))
766 bad_reason = "nonzero mapcount";
767 if (unlikely(page->mapping != NULL))
768 bad_reason = "non-NULL mapping";
769 if (unlikely(page_ref_count(page) != 0))
770 bad_reason = "nonzero _count";
771 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
772 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
773 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
776 if (unlikely(page->mem_cgroup))
777 bad_reason = "page still charged to cgroup";
779 if (unlikely(bad_reason)) {
780 bad_page(page, bad_reason, bad_flags);
783 page_cpupid_reset_last(page);
784 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
785 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
790 * Frees a number of pages from the PCP lists
791 * Assumes all pages on list are in same zone, and of same order.
792 * count is the number of pages to free.
794 * If the zone was previously in an "all pages pinned" state then look to
795 * see if this freeing clears that state.
797 * And clear the zone's pages_scanned counter, to hold off the "all pages are
798 * pinned" detection logic.
800 static void free_pcppages_bulk(struct zone *zone, int count,
801 struct per_cpu_pages *pcp)
806 unsigned long nr_scanned;
808 spin_lock(&zone->lock);
809 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
811 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
815 struct list_head *list;
818 * Remove pages from lists in a round-robin fashion. A
819 * batch_free count is maintained that is incremented when an
820 * empty list is encountered. This is so more pages are freed
821 * off fuller lists instead of spinning excessively around empty
826 if (++migratetype == MIGRATE_PCPTYPES)
828 list = &pcp->lists[migratetype];
829 } while (list_empty(list));
831 /* This is the only non-empty list. Free them all. */
832 if (batch_free == MIGRATE_PCPTYPES)
833 batch_free = to_free;
836 int mt; /* migratetype of the to-be-freed page */
838 page = list_last_entry(list, struct page, lru);
839 /* must delete as __free_one_page list manipulates */
840 list_del(&page->lru);
842 mt = get_pcppage_migratetype(page);
843 /* MIGRATE_ISOLATE page should not go to pcplists */
844 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
845 /* Pageblock could have been isolated meanwhile */
846 if (unlikely(has_isolate_pageblock(zone)))
847 mt = get_pageblock_migratetype(page);
849 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
850 trace_mm_page_pcpu_drain(page, 0, mt);
851 } while (--to_free && --batch_free && !list_empty(list));
853 spin_unlock(&zone->lock);
856 static void free_one_page(struct zone *zone,
857 struct page *page, unsigned long pfn,
861 unsigned long nr_scanned;
862 spin_lock(&zone->lock);
863 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
865 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
867 if (unlikely(has_isolate_pageblock(zone) ||
868 is_migrate_isolate(migratetype))) {
869 migratetype = get_pfnblock_migratetype(page, pfn);
871 __free_one_page(page, pfn, zone, order, migratetype);
872 spin_unlock(&zone->lock);
875 static int free_tail_pages_check(struct page *head_page, struct page *page)
880 * We rely page->lru.next never has bit 0 set, unless the page
881 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
883 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
885 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
889 switch (page - head_page) {
891 /* the first tail page: ->mapping is compound_mapcount() */
892 if (unlikely(compound_mapcount(page))) {
893 bad_page(page, "nonzero compound_mapcount", 0);
899 * the second tail page: ->mapping is
900 * page_deferred_list().next -- ignore value.
904 if (page->mapping != TAIL_MAPPING) {
905 bad_page(page, "corrupted mapping in tail page", 0);
910 if (unlikely(!PageTail(page))) {
911 bad_page(page, "PageTail not set", 0);
914 if (unlikely(compound_head(page) != head_page)) {
915 bad_page(page, "compound_head not consistent", 0);
920 page->mapping = NULL;
921 clear_compound_head(page);
925 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
926 unsigned long zone, int nid)
928 set_page_links(page, zone, nid, pfn);
929 init_page_count(page);
930 page_mapcount_reset(page);
931 page_cpupid_reset_last(page);
933 INIT_LIST_HEAD(&page->lru);
934 #ifdef WANT_PAGE_VIRTUAL
935 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
936 if (!is_highmem_idx(zone))
937 set_page_address(page, __va(pfn << PAGE_SHIFT));
941 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
944 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
947 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
948 static void init_reserved_page(unsigned long pfn)
953 if (!early_page_uninitialised(pfn))
956 nid = early_pfn_to_nid(pfn);
957 pgdat = NODE_DATA(nid);
959 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
960 struct zone *zone = &pgdat->node_zones[zid];
962 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
965 __init_single_pfn(pfn, zid, nid);
968 static inline void init_reserved_page(unsigned long pfn)
971 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
974 * Initialised pages do not have PageReserved set. This function is
975 * called for each range allocated by the bootmem allocator and
976 * marks the pages PageReserved. The remaining valid pages are later
977 * sent to the buddy page allocator.
979 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
981 unsigned long start_pfn = PFN_DOWN(start);
982 unsigned long end_pfn = PFN_UP(end);
984 for (; start_pfn < end_pfn; start_pfn++) {
985 if (pfn_valid(start_pfn)) {
986 struct page *page = pfn_to_page(start_pfn);
988 init_reserved_page(start_pfn);
990 /* Avoid false-positive PageTail() */
991 INIT_LIST_HEAD(&page->lru);
993 SetPageReserved(page);
998 static bool free_pages_prepare(struct page *page, unsigned int order)
1000 bool compound = PageCompound(page);
1003 VM_BUG_ON_PAGE(PageTail(page), page);
1004 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1006 trace_mm_page_free(page, order);
1007 kmemcheck_free_shadow(page, order);
1008 kasan_free_pages(page, order);
1011 page->mapping = NULL;
1012 bad += free_pages_check(page);
1013 for (i = 1; i < (1 << order); i++) {
1015 bad += free_tail_pages_check(page, page + i);
1016 bad += free_pages_check(page + i);
1021 reset_page_owner(page, order);
1023 if (!PageHighMem(page)) {
1024 debug_check_no_locks_freed(page_address(page),
1025 PAGE_SIZE << order);
1026 debug_check_no_obj_freed(page_address(page),
1027 PAGE_SIZE << order);
1029 arch_free_page(page, order);
1030 kernel_poison_pages(page, 1 << order, 0);
1031 kernel_map_pages(page, 1 << order, 0);
1036 static void __free_pages_ok(struct page *page, unsigned int order)
1038 unsigned long flags;
1040 unsigned long pfn = page_to_pfn(page);
1042 if (!free_pages_prepare(page, order))
1045 migratetype = get_pfnblock_migratetype(page, pfn);
1046 local_irq_save(flags);
1047 __count_vm_events(PGFREE, 1 << order);
1048 free_one_page(page_zone(page), page, pfn, order, migratetype);
1049 local_irq_restore(flags);
1052 static void __init __free_pages_boot_core(struct page *page,
1053 unsigned long pfn, unsigned int order)
1055 unsigned int nr_pages = 1 << order;
1056 struct page *p = page;
1060 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1062 __ClearPageReserved(p);
1063 set_page_count(p, 0);
1065 __ClearPageReserved(p);
1066 set_page_count(p, 0);
1068 page_zone(page)->managed_pages += nr_pages;
1069 set_page_refcounted(page);
1070 __free_pages(page, order);
1073 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1074 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1076 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1078 int __meminit early_pfn_to_nid(unsigned long pfn)
1080 static DEFINE_SPINLOCK(early_pfn_lock);
1083 spin_lock(&early_pfn_lock);
1084 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1087 spin_unlock(&early_pfn_lock);
1093 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1094 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1095 struct mminit_pfnnid_cache *state)
1099 nid = __early_pfn_to_nid(pfn, state);
1100 if (nid >= 0 && nid != node)
1105 /* Only safe to use early in boot when initialisation is single-threaded */
1106 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1108 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1113 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1117 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1118 struct mminit_pfnnid_cache *state)
1125 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1128 if (early_page_uninitialised(pfn))
1130 return __free_pages_boot_core(page, pfn, order);
1134 * Check that the whole (or subset of) a pageblock given by the interval of
1135 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1136 * with the migration of free compaction scanner. The scanners then need to
1137 * use only pfn_valid_within() check for arches that allow holes within
1140 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1142 * It's possible on some configurations to have a setup like node0 node1 node0
1143 * i.e. it's possible that all pages within a zones range of pages do not
1144 * belong to a single zone. We assume that a border between node0 and node1
1145 * can occur within a single pageblock, but not a node0 node1 node0
1146 * interleaving within a single pageblock. It is therefore sufficient to check
1147 * the first and last page of a pageblock and avoid checking each individual
1148 * page in a pageblock.
1150 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1151 unsigned long end_pfn, struct zone *zone)
1153 struct page *start_page;
1154 struct page *end_page;
1156 /* end_pfn is one past the range we are checking */
1159 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1162 start_page = pfn_to_page(start_pfn);
1164 if (page_zone(start_page) != zone)
1167 end_page = pfn_to_page(end_pfn);
1169 /* This gives a shorter code than deriving page_zone(end_page) */
1170 if (page_zone_id(start_page) != page_zone_id(end_page))
1176 void set_zone_contiguous(struct zone *zone)
1178 unsigned long block_start_pfn = zone->zone_start_pfn;
1179 unsigned long block_end_pfn;
1181 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1182 for (; block_start_pfn < zone_end_pfn(zone);
1183 block_start_pfn = block_end_pfn,
1184 block_end_pfn += pageblock_nr_pages) {
1186 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1188 if (!__pageblock_pfn_to_page(block_start_pfn,
1189 block_end_pfn, zone))
1193 /* We confirm that there is no hole */
1194 zone->contiguous = true;
1197 void clear_zone_contiguous(struct zone *zone)
1199 zone->contiguous = false;
1202 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1203 static void __init deferred_free_range(struct page *page,
1204 unsigned long pfn, int nr_pages)
1211 /* Free a large naturally-aligned chunk if possible */
1212 if (nr_pages == MAX_ORDER_NR_PAGES &&
1213 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1214 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1215 __free_pages_boot_core(page, pfn, MAX_ORDER-1);
1219 for (i = 0; i < nr_pages; i++, page++, pfn++)
1220 __free_pages_boot_core(page, pfn, 0);
1223 /* Completion tracking for deferred_init_memmap() threads */
1224 static atomic_t pgdat_init_n_undone __initdata;
1225 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1227 static inline void __init pgdat_init_report_one_done(void)
1229 if (atomic_dec_and_test(&pgdat_init_n_undone))
1230 complete(&pgdat_init_all_done_comp);
1233 /* Initialise remaining memory on a node */
1234 static int __init deferred_init_memmap(void *data)
1236 pg_data_t *pgdat = data;
1237 int nid = pgdat->node_id;
1238 struct mminit_pfnnid_cache nid_init_state = { };
1239 unsigned long start = jiffies;
1240 unsigned long nr_pages = 0;
1241 unsigned long walk_start, walk_end;
1244 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1245 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1247 if (first_init_pfn == ULONG_MAX) {
1248 pgdat_init_report_one_done();
1252 /* Bind memory initialisation thread to a local node if possible */
1253 if (!cpumask_empty(cpumask))
1254 set_cpus_allowed_ptr(current, cpumask);
1256 /* Sanity check boundaries */
1257 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1258 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1259 pgdat->first_deferred_pfn = ULONG_MAX;
1261 /* Only the highest zone is deferred so find it */
1262 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1263 zone = pgdat->node_zones + zid;
1264 if (first_init_pfn < zone_end_pfn(zone))
1268 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1269 unsigned long pfn, end_pfn;
1270 struct page *page = NULL;
1271 struct page *free_base_page = NULL;
1272 unsigned long free_base_pfn = 0;
1275 end_pfn = min(walk_end, zone_end_pfn(zone));
1276 pfn = first_init_pfn;
1277 if (pfn < walk_start)
1279 if (pfn < zone->zone_start_pfn)
1280 pfn = zone->zone_start_pfn;
1282 for (; pfn < end_pfn; pfn++) {
1283 if (!pfn_valid_within(pfn))
1287 * Ensure pfn_valid is checked every
1288 * MAX_ORDER_NR_PAGES for memory holes
1290 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1291 if (!pfn_valid(pfn)) {
1297 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1302 /* Minimise pfn page lookups and scheduler checks */
1303 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1306 nr_pages += nr_to_free;
1307 deferred_free_range(free_base_page,
1308 free_base_pfn, nr_to_free);
1309 free_base_page = NULL;
1310 free_base_pfn = nr_to_free = 0;
1312 page = pfn_to_page(pfn);
1317 VM_BUG_ON(page_zone(page) != zone);
1321 __init_single_page(page, pfn, zid, nid);
1322 if (!free_base_page) {
1323 free_base_page = page;
1324 free_base_pfn = pfn;
1329 /* Where possible, batch up pages for a single free */
1332 /* Free the current block of pages to allocator */
1333 nr_pages += nr_to_free;
1334 deferred_free_range(free_base_page, free_base_pfn,
1336 free_base_page = NULL;
1337 free_base_pfn = nr_to_free = 0;
1340 first_init_pfn = max(end_pfn, first_init_pfn);
1343 /* Sanity check that the next zone really is unpopulated */
1344 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1346 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1347 jiffies_to_msecs(jiffies - start));
1349 pgdat_init_report_one_done();
1352 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1354 void __init page_alloc_init_late(void)
1358 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1361 /* There will be num_node_state(N_MEMORY) threads */
1362 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1363 for_each_node_state(nid, N_MEMORY) {
1364 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1367 /* Block until all are initialised */
1368 wait_for_completion(&pgdat_init_all_done_comp);
1370 /* Reinit limits that are based on free pages after the kernel is up */
1371 files_maxfiles_init();
1374 for_each_populated_zone(zone)
1375 set_zone_contiguous(zone);
1379 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1380 void __init init_cma_reserved_pageblock(struct page *page)
1382 unsigned i = pageblock_nr_pages;
1383 struct page *p = page;
1386 __ClearPageReserved(p);
1387 set_page_count(p, 0);
1390 set_pageblock_migratetype(page, MIGRATE_CMA);
1392 if (pageblock_order >= MAX_ORDER) {
1393 i = pageblock_nr_pages;
1396 set_page_refcounted(p);
1397 __free_pages(p, MAX_ORDER - 1);
1398 p += MAX_ORDER_NR_PAGES;
1399 } while (i -= MAX_ORDER_NR_PAGES);
1401 set_page_refcounted(page);
1402 __free_pages(page, pageblock_order);
1405 adjust_managed_page_count(page, pageblock_nr_pages);
1410 * The order of subdivision here is critical for the IO subsystem.
1411 * Please do not alter this order without good reasons and regression
1412 * testing. Specifically, as large blocks of memory are subdivided,
1413 * the order in which smaller blocks are delivered depends on the order
1414 * they're subdivided in this function. This is the primary factor
1415 * influencing the order in which pages are delivered to the IO
1416 * subsystem according to empirical testing, and this is also justified
1417 * by considering the behavior of a buddy system containing a single
1418 * large block of memory acted on by a series of small allocations.
1419 * This behavior is a critical factor in sglist merging's success.
1423 static inline void expand(struct zone *zone, struct page *page,
1424 int low, int high, struct free_area *area,
1427 unsigned long size = 1 << high;
1429 while (high > low) {
1433 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1435 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1436 debug_guardpage_enabled() &&
1437 high < debug_guardpage_minorder()) {
1439 * Mark as guard pages (or page), that will allow to
1440 * merge back to allocator when buddy will be freed.
1441 * Corresponding page table entries will not be touched,
1442 * pages will stay not present in virtual address space
1444 set_page_guard(zone, &page[size], high, migratetype);
1447 list_add(&page[size].lru, &area->free_list[migratetype]);
1449 set_page_order(&page[size], high);
1454 * This page is about to be returned from the page allocator
1456 static inline int check_new_page(struct page *page)
1458 const char *bad_reason = NULL;
1459 unsigned long bad_flags = 0;
1461 if (unlikely(atomic_read(&page->_mapcount) != -1))
1462 bad_reason = "nonzero mapcount";
1463 if (unlikely(page->mapping != NULL))
1464 bad_reason = "non-NULL mapping";
1465 if (unlikely(page_ref_count(page) != 0))
1466 bad_reason = "nonzero _count";
1467 if (unlikely(page->flags & __PG_HWPOISON)) {
1468 bad_reason = "HWPoisoned (hardware-corrupted)";
1469 bad_flags = __PG_HWPOISON;
1471 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1472 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1473 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1476 if (unlikely(page->mem_cgroup))
1477 bad_reason = "page still charged to cgroup";
1479 if (unlikely(bad_reason)) {
1480 bad_page(page, bad_reason, bad_flags);
1486 static inline bool free_pages_prezeroed(bool poisoned)
1488 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1489 page_poisoning_enabled() && poisoned;
1492 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1496 bool poisoned = true;
1498 for (i = 0; i < (1 << order); i++) {
1499 struct page *p = page + i;
1500 if (unlikely(check_new_page(p)))
1503 poisoned &= page_is_poisoned(p);
1506 set_page_private(page, 0);
1507 set_page_refcounted(page);
1509 arch_alloc_page(page, order);
1510 kernel_map_pages(page, 1 << order, 1);
1511 kernel_poison_pages(page, 1 << order, 1);
1512 kasan_alloc_pages(page, order);
1514 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1515 for (i = 0; i < (1 << order); i++)
1516 clear_highpage(page + i);
1518 if (order && (gfp_flags & __GFP_COMP))
1519 prep_compound_page(page, order);
1521 set_page_owner(page, order, gfp_flags);
1524 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1525 * allocate the page. The expectation is that the caller is taking
1526 * steps that will free more memory. The caller should avoid the page
1527 * being used for !PFMEMALLOC purposes.
1529 if (alloc_flags & ALLOC_NO_WATERMARKS)
1530 set_page_pfmemalloc(page);
1532 clear_page_pfmemalloc(page);
1538 * Go through the free lists for the given migratetype and remove
1539 * the smallest available page from the freelists
1542 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1545 unsigned int current_order;
1546 struct free_area *area;
1549 /* Find a page of the appropriate size in the preferred list */
1550 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1551 area = &(zone->free_area[current_order]);
1552 page = list_first_entry_or_null(&area->free_list[migratetype],
1556 list_del(&page->lru);
1557 rmv_page_order(page);
1559 expand(zone, page, order, current_order, area, migratetype);
1560 set_pcppage_migratetype(page, migratetype);
1569 * This array describes the order lists are fallen back to when
1570 * the free lists for the desirable migrate type are depleted
1572 static int fallbacks[MIGRATE_TYPES][4] = {
1573 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1574 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1575 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1577 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1579 #ifdef CONFIG_MEMORY_ISOLATION
1580 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1585 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1588 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1591 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1592 unsigned int order) { return NULL; }
1596 * Move the free pages in a range to the free lists of the requested type.
1597 * Note that start_page and end_pages are not aligned on a pageblock
1598 * boundary. If alignment is required, use move_freepages_block()
1600 int move_freepages(struct zone *zone,
1601 struct page *start_page, struct page *end_page,
1606 int pages_moved = 0;
1608 #ifndef CONFIG_HOLES_IN_ZONE
1610 * page_zone is not safe to call in this context when
1611 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1612 * anyway as we check zone boundaries in move_freepages_block().
1613 * Remove at a later date when no bug reports exist related to
1614 * grouping pages by mobility
1616 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1619 for (page = start_page; page <= end_page;) {
1620 /* Make sure we are not inadvertently changing nodes */
1621 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1623 if (!pfn_valid_within(page_to_pfn(page))) {
1628 if (!PageBuddy(page)) {
1633 order = page_order(page);
1634 list_move(&page->lru,
1635 &zone->free_area[order].free_list[migratetype]);
1637 pages_moved += 1 << order;
1643 int move_freepages_block(struct zone *zone, struct page *page,
1646 unsigned long start_pfn, end_pfn;
1647 struct page *start_page, *end_page;
1649 start_pfn = page_to_pfn(page);
1650 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1651 start_page = pfn_to_page(start_pfn);
1652 end_page = start_page + pageblock_nr_pages - 1;
1653 end_pfn = start_pfn + pageblock_nr_pages - 1;
1655 /* Do not cross zone boundaries */
1656 if (!zone_spans_pfn(zone, start_pfn))
1658 if (!zone_spans_pfn(zone, end_pfn))
1661 return move_freepages(zone, start_page, end_page, migratetype);
1664 static void change_pageblock_range(struct page *pageblock_page,
1665 int start_order, int migratetype)
1667 int nr_pageblocks = 1 << (start_order - pageblock_order);
1669 while (nr_pageblocks--) {
1670 set_pageblock_migratetype(pageblock_page, migratetype);
1671 pageblock_page += pageblock_nr_pages;
1676 * When we are falling back to another migratetype during allocation, try to
1677 * steal extra free pages from the same pageblocks to satisfy further
1678 * allocations, instead of polluting multiple pageblocks.
1680 * If we are stealing a relatively large buddy page, it is likely there will
1681 * be more free pages in the pageblock, so try to steal them all. For
1682 * reclaimable and unmovable allocations, we steal regardless of page size,
1683 * as fragmentation caused by those allocations polluting movable pageblocks
1684 * is worse than movable allocations stealing from unmovable and reclaimable
1687 static bool can_steal_fallback(unsigned int order, int start_mt)
1690 * Leaving this order check is intended, although there is
1691 * relaxed order check in next check. The reason is that
1692 * we can actually steal whole pageblock if this condition met,
1693 * but, below check doesn't guarantee it and that is just heuristic
1694 * so could be changed anytime.
1696 if (order >= pageblock_order)
1699 if (order >= pageblock_order / 2 ||
1700 start_mt == MIGRATE_RECLAIMABLE ||
1701 start_mt == MIGRATE_UNMOVABLE ||
1702 page_group_by_mobility_disabled)
1709 * This function implements actual steal behaviour. If order is large enough,
1710 * we can steal whole pageblock. If not, we first move freepages in this
1711 * pageblock and check whether half of pages are moved or not. If half of
1712 * pages are moved, we can change migratetype of pageblock and permanently
1713 * use it's pages as requested migratetype in the future.
1715 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1718 unsigned int current_order = page_order(page);
1721 /* Take ownership for orders >= pageblock_order */
1722 if (current_order >= pageblock_order) {
1723 change_pageblock_range(page, current_order, start_type);
1727 pages = move_freepages_block(zone, page, start_type);
1729 /* Claim the whole block if over half of it is free */
1730 if (pages >= (1 << (pageblock_order-1)) ||
1731 page_group_by_mobility_disabled)
1732 set_pageblock_migratetype(page, start_type);
1736 * Check whether there is a suitable fallback freepage with requested order.
1737 * If only_stealable is true, this function returns fallback_mt only if
1738 * we can steal other freepages all together. This would help to reduce
1739 * fragmentation due to mixed migratetype pages in one pageblock.
1741 int find_suitable_fallback(struct free_area *area, unsigned int order,
1742 int migratetype, bool only_stealable, bool *can_steal)
1747 if (area->nr_free == 0)
1752 fallback_mt = fallbacks[migratetype][i];
1753 if (fallback_mt == MIGRATE_TYPES)
1756 if (list_empty(&area->free_list[fallback_mt]))
1759 if (can_steal_fallback(order, migratetype))
1762 if (!only_stealable)
1773 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1774 * there are no empty page blocks that contain a page with a suitable order
1776 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
1777 unsigned int alloc_order)
1780 unsigned long max_managed, flags;
1783 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1784 * Check is race-prone but harmless.
1786 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
1787 if (zone->nr_reserved_highatomic >= max_managed)
1790 spin_lock_irqsave(&zone->lock, flags);
1792 /* Recheck the nr_reserved_highatomic limit under the lock */
1793 if (zone->nr_reserved_highatomic >= max_managed)
1797 mt = get_pageblock_migratetype(page);
1798 if (mt != MIGRATE_HIGHATOMIC &&
1799 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
1800 zone->nr_reserved_highatomic += pageblock_nr_pages;
1801 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
1802 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
1806 spin_unlock_irqrestore(&zone->lock, flags);
1810 * Used when an allocation is about to fail under memory pressure. This
1811 * potentially hurts the reliability of high-order allocations when under
1812 * intense memory pressure but failed atomic allocations should be easier
1813 * to recover from than an OOM.
1815 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
1817 struct zonelist *zonelist = ac->zonelist;
1818 unsigned long flags;
1824 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
1826 /* Preserve at least one pageblock */
1827 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
1830 spin_lock_irqsave(&zone->lock, flags);
1831 for (order = 0; order < MAX_ORDER; order++) {
1832 struct free_area *area = &(zone->free_area[order]);
1834 page = list_first_entry_or_null(
1835 &area->free_list[MIGRATE_HIGHATOMIC],
1841 * It should never happen but changes to locking could
1842 * inadvertently allow a per-cpu drain to add pages
1843 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1844 * and watch for underflows.
1846 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
1847 zone->nr_reserved_highatomic);
1850 * Convert to ac->migratetype and avoid the normal
1851 * pageblock stealing heuristics. Minimally, the caller
1852 * is doing the work and needs the pages. More
1853 * importantly, if the block was always converted to
1854 * MIGRATE_UNMOVABLE or another type then the number
1855 * of pageblocks that cannot be completely freed
1858 set_pageblock_migratetype(page, ac->migratetype);
1859 move_freepages_block(zone, page, ac->migratetype);
1860 spin_unlock_irqrestore(&zone->lock, flags);
1863 spin_unlock_irqrestore(&zone->lock, flags);
1867 /* Remove an element from the buddy allocator from the fallback list */
1868 static inline struct page *
1869 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1871 struct free_area *area;
1872 unsigned int current_order;
1877 /* Find the largest possible block of pages in the other list */
1878 for (current_order = MAX_ORDER-1;
1879 current_order >= order && current_order <= MAX_ORDER-1;
1881 area = &(zone->free_area[current_order]);
1882 fallback_mt = find_suitable_fallback(area, current_order,
1883 start_migratetype, false, &can_steal);
1884 if (fallback_mt == -1)
1887 page = list_first_entry(&area->free_list[fallback_mt],
1890 steal_suitable_fallback(zone, page, start_migratetype);
1892 /* Remove the page from the freelists */
1894 list_del(&page->lru);
1895 rmv_page_order(page);
1897 expand(zone, page, order, current_order, area,
1900 * The pcppage_migratetype may differ from pageblock's
1901 * migratetype depending on the decisions in
1902 * find_suitable_fallback(). This is OK as long as it does not
1903 * differ for MIGRATE_CMA pageblocks. Those can be used as
1904 * fallback only via special __rmqueue_cma_fallback() function
1906 set_pcppage_migratetype(page, start_migratetype);
1908 trace_mm_page_alloc_extfrag(page, order, current_order,
1909 start_migratetype, fallback_mt);
1918 * Do the hard work of removing an element from the buddy allocator.
1919 * Call me with the zone->lock already held.
1921 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1926 page = __rmqueue_smallest(zone, order, migratetype);
1927 if (unlikely(!page)) {
1928 if (migratetype == MIGRATE_MOVABLE)
1929 page = __rmqueue_cma_fallback(zone, order);
1932 page = __rmqueue_fallback(zone, order, migratetype);
1935 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1940 * Obtain a specified number of elements from the buddy allocator, all under
1941 * a single hold of the lock, for efficiency. Add them to the supplied list.
1942 * Returns the number of new pages which were placed at *list.
1944 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1945 unsigned long count, struct list_head *list,
1946 int migratetype, bool cold)
1950 spin_lock(&zone->lock);
1951 for (i = 0; i < count; ++i) {
1952 struct page *page = __rmqueue(zone, order, migratetype);
1953 if (unlikely(page == NULL))
1957 * Split buddy pages returned by expand() are received here
1958 * in physical page order. The page is added to the callers and
1959 * list and the list head then moves forward. From the callers
1960 * perspective, the linked list is ordered by page number in
1961 * some conditions. This is useful for IO devices that can
1962 * merge IO requests if the physical pages are ordered
1966 list_add(&page->lru, list);
1968 list_add_tail(&page->lru, list);
1970 if (is_migrate_cma(get_pcppage_migratetype(page)))
1971 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1974 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1975 spin_unlock(&zone->lock);
1981 * Called from the vmstat counter updater to drain pagesets of this
1982 * currently executing processor on remote nodes after they have
1985 * Note that this function must be called with the thread pinned to
1986 * a single processor.
1988 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1990 unsigned long flags;
1991 int to_drain, batch;
1993 local_irq_save(flags);
1994 batch = READ_ONCE(pcp->batch);
1995 to_drain = min(pcp->count, batch);
1997 free_pcppages_bulk(zone, to_drain, pcp);
1998 pcp->count -= to_drain;
2000 local_irq_restore(flags);
2005 * Drain pcplists of the indicated processor and zone.
2007 * The processor must either be the current processor and the
2008 * thread pinned to the current processor or a processor that
2011 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2013 unsigned long flags;
2014 struct per_cpu_pageset *pset;
2015 struct per_cpu_pages *pcp;
2017 local_irq_save(flags);
2018 pset = per_cpu_ptr(zone->pageset, cpu);
2022 free_pcppages_bulk(zone, pcp->count, pcp);
2025 local_irq_restore(flags);
2029 * Drain pcplists of all zones on the indicated processor.
2031 * The processor must either be the current processor and the
2032 * thread pinned to the current processor or a processor that
2035 static void drain_pages(unsigned int cpu)
2039 for_each_populated_zone(zone) {
2040 drain_pages_zone(cpu, zone);
2045 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2047 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2048 * the single zone's pages.
2050 void drain_local_pages(struct zone *zone)
2052 int cpu = smp_processor_id();
2055 drain_pages_zone(cpu, zone);
2061 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2063 * When zone parameter is non-NULL, spill just the single zone's pages.
2065 * Note that this code is protected against sending an IPI to an offline
2066 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2067 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2068 * nothing keeps CPUs from showing up after we populated the cpumask and
2069 * before the call to on_each_cpu_mask().
2071 void drain_all_pages(struct zone *zone)
2076 * Allocate in the BSS so we wont require allocation in
2077 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2079 static cpumask_t cpus_with_pcps;
2082 * We don't care about racing with CPU hotplug event
2083 * as offline notification will cause the notified
2084 * cpu to drain that CPU pcps and on_each_cpu_mask
2085 * disables preemption as part of its processing
2087 for_each_online_cpu(cpu) {
2088 struct per_cpu_pageset *pcp;
2090 bool has_pcps = false;
2093 pcp = per_cpu_ptr(zone->pageset, cpu);
2097 for_each_populated_zone(z) {
2098 pcp = per_cpu_ptr(z->pageset, cpu);
2099 if (pcp->pcp.count) {
2107 cpumask_set_cpu(cpu, &cpus_with_pcps);
2109 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2111 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2115 #ifdef CONFIG_HIBERNATION
2117 void mark_free_pages(struct zone *zone)
2119 unsigned long pfn, max_zone_pfn;
2120 unsigned long flags;
2121 unsigned int order, t;
2124 if (zone_is_empty(zone))
2127 spin_lock_irqsave(&zone->lock, flags);
2129 max_zone_pfn = zone_end_pfn(zone);
2130 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2131 if (pfn_valid(pfn)) {
2132 page = pfn_to_page(pfn);
2133 if (!swsusp_page_is_forbidden(page))
2134 swsusp_unset_page_free(page);
2137 for_each_migratetype_order(order, t) {
2138 list_for_each_entry(page,
2139 &zone->free_area[order].free_list[t], lru) {
2142 pfn = page_to_pfn(page);
2143 for (i = 0; i < (1UL << order); i++)
2144 swsusp_set_page_free(pfn_to_page(pfn + i));
2147 spin_unlock_irqrestore(&zone->lock, flags);
2149 #endif /* CONFIG_PM */
2152 * Free a 0-order page
2153 * cold == true ? free a cold page : free a hot page
2155 void free_hot_cold_page(struct page *page, bool cold)
2157 struct zone *zone = page_zone(page);
2158 struct per_cpu_pages *pcp;
2159 unsigned long flags;
2160 unsigned long pfn = page_to_pfn(page);
2163 if (!free_pages_prepare(page, 0))
2166 migratetype = get_pfnblock_migratetype(page, pfn);
2167 set_pcppage_migratetype(page, migratetype);
2168 local_irq_save(flags);
2169 __count_vm_event(PGFREE);
2172 * We only track unmovable, reclaimable and movable on pcp lists.
2173 * Free ISOLATE pages back to the allocator because they are being
2174 * offlined but treat RESERVE as movable pages so we can get those
2175 * areas back if necessary. Otherwise, we may have to free
2176 * excessively into the page allocator
2178 if (migratetype >= MIGRATE_PCPTYPES) {
2179 if (unlikely(is_migrate_isolate(migratetype))) {
2180 free_one_page(zone, page, pfn, 0, migratetype);
2183 migratetype = MIGRATE_MOVABLE;
2186 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2188 list_add(&page->lru, &pcp->lists[migratetype]);
2190 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2192 if (pcp->count >= pcp->high) {
2193 unsigned long batch = READ_ONCE(pcp->batch);
2194 free_pcppages_bulk(zone, batch, pcp);
2195 pcp->count -= batch;
2199 local_irq_restore(flags);
2203 * Free a list of 0-order pages
2205 void free_hot_cold_page_list(struct list_head *list, bool cold)
2207 struct page *page, *next;
2209 list_for_each_entry_safe(page, next, list, lru) {
2210 trace_mm_page_free_batched(page, cold);
2211 free_hot_cold_page(page, cold);
2216 * split_page takes a non-compound higher-order page, and splits it into
2217 * n (1<<order) sub-pages: page[0..n]
2218 * Each sub-page must be freed individually.
2220 * Note: this is probably too low level an operation for use in drivers.
2221 * Please consult with lkml before using this in your driver.
2223 void split_page(struct page *page, unsigned int order)
2228 VM_BUG_ON_PAGE(PageCompound(page), page);
2229 VM_BUG_ON_PAGE(!page_count(page), page);
2231 #ifdef CONFIG_KMEMCHECK
2233 * Split shadow pages too, because free(page[0]) would
2234 * otherwise free the whole shadow.
2236 if (kmemcheck_page_is_tracked(page))
2237 split_page(virt_to_page(page[0].shadow), order);
2240 gfp_mask = get_page_owner_gfp(page);
2241 set_page_owner(page, 0, gfp_mask);
2242 for (i = 1; i < (1 << order); i++) {
2243 set_page_refcounted(page + i);
2244 set_page_owner(page + i, 0, gfp_mask);
2247 EXPORT_SYMBOL_GPL(split_page);
2249 int __isolate_free_page(struct page *page, unsigned int order)
2251 unsigned long watermark;
2255 BUG_ON(!PageBuddy(page));
2257 zone = page_zone(page);
2258 mt = get_pageblock_migratetype(page);
2260 if (!is_migrate_isolate(mt)) {
2261 /* Obey watermarks as if the page was being allocated */
2262 watermark = low_wmark_pages(zone) + (1 << order);
2263 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2266 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2269 /* Remove page from free list */
2270 list_del(&page->lru);
2271 zone->free_area[order].nr_free--;
2272 rmv_page_order(page);
2274 set_page_owner(page, order, __GFP_MOVABLE);
2276 /* Set the pageblock if the isolated page is at least a pageblock */
2277 if (order >= pageblock_order - 1) {
2278 struct page *endpage = page + (1 << order) - 1;
2279 for (; page < endpage; page += pageblock_nr_pages) {
2280 int mt = get_pageblock_migratetype(page);
2281 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2282 set_pageblock_migratetype(page,
2288 return 1UL << order;
2292 * Similar to split_page except the page is already free. As this is only
2293 * being used for migration, the migratetype of the block also changes.
2294 * As this is called with interrupts disabled, the caller is responsible
2295 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2298 * Note: this is probably too low level an operation for use in drivers.
2299 * Please consult with lkml before using this in your driver.
2301 int split_free_page(struct page *page)
2306 order = page_order(page);
2308 nr_pages = __isolate_free_page(page, order);
2312 /* Split into individual pages */
2313 set_page_refcounted(page);
2314 split_page(page, order);
2319 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2322 struct page *buffered_rmqueue(struct zone *preferred_zone,
2323 struct zone *zone, unsigned int order,
2324 gfp_t gfp_flags, int alloc_flags, int migratetype)
2326 unsigned long flags;
2328 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2330 if (likely(order == 0)) {
2331 struct per_cpu_pages *pcp;
2332 struct list_head *list;
2334 local_irq_save(flags);
2335 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2336 list = &pcp->lists[migratetype];
2337 if (list_empty(list)) {
2338 pcp->count += rmqueue_bulk(zone, 0,
2341 if (unlikely(list_empty(list)))
2346 page = list_last_entry(list, struct page, lru);
2348 page = list_first_entry(list, struct page, lru);
2350 list_del(&page->lru);
2354 * We most definitely don't want callers attempting to
2355 * allocate greater than order-1 page units with __GFP_NOFAIL.
2357 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2358 spin_lock_irqsave(&zone->lock, flags);
2361 if (alloc_flags & ALLOC_HARDER) {
2362 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2364 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2367 page = __rmqueue(zone, order, migratetype);
2368 spin_unlock(&zone->lock);
2371 __mod_zone_freepage_state(zone, -(1 << order),
2372 get_pcppage_migratetype(page));
2375 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2376 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2377 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2378 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2380 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2381 zone_statistics(preferred_zone, zone, gfp_flags);
2382 local_irq_restore(flags);
2384 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2388 local_irq_restore(flags);
2392 #ifdef CONFIG_FAIL_PAGE_ALLOC
2395 struct fault_attr attr;
2397 bool ignore_gfp_highmem;
2398 bool ignore_gfp_reclaim;
2400 } fail_page_alloc = {
2401 .attr = FAULT_ATTR_INITIALIZER,
2402 .ignore_gfp_reclaim = true,
2403 .ignore_gfp_highmem = true,
2407 static int __init setup_fail_page_alloc(char *str)
2409 return setup_fault_attr(&fail_page_alloc.attr, str);
2411 __setup("fail_page_alloc=", setup_fail_page_alloc);
2413 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2415 if (order < fail_page_alloc.min_order)
2417 if (gfp_mask & __GFP_NOFAIL)
2419 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2421 if (fail_page_alloc.ignore_gfp_reclaim &&
2422 (gfp_mask & __GFP_DIRECT_RECLAIM))
2425 return should_fail(&fail_page_alloc.attr, 1 << order);
2428 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2430 static int __init fail_page_alloc_debugfs(void)
2432 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2435 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2436 &fail_page_alloc.attr);
2438 return PTR_ERR(dir);
2440 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2441 &fail_page_alloc.ignore_gfp_reclaim))
2443 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2444 &fail_page_alloc.ignore_gfp_highmem))
2446 if (!debugfs_create_u32("min-order", mode, dir,
2447 &fail_page_alloc.min_order))
2452 debugfs_remove_recursive(dir);
2457 late_initcall(fail_page_alloc_debugfs);
2459 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2461 #else /* CONFIG_FAIL_PAGE_ALLOC */
2463 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2468 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2471 * Return true if free base pages are above 'mark'. For high-order checks it
2472 * will return true of the order-0 watermark is reached and there is at least
2473 * one free page of a suitable size. Checking now avoids taking the zone lock
2474 * to check in the allocation paths if no pages are free.
2476 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2477 unsigned long mark, int classzone_idx, int alloc_flags,
2482 const int alloc_harder = (alloc_flags & ALLOC_HARDER);
2484 /* free_pages may go negative - that's OK */
2485 free_pages -= (1 << order) - 1;
2487 if (alloc_flags & ALLOC_HIGH)
2491 * If the caller does not have rights to ALLOC_HARDER then subtract
2492 * the high-atomic reserves. This will over-estimate the size of the
2493 * atomic reserve but it avoids a search.
2495 if (likely(!alloc_harder))
2496 free_pages -= z->nr_reserved_highatomic;
2501 /* If allocation can't use CMA areas don't use free CMA pages */
2502 if (!(alloc_flags & ALLOC_CMA))
2503 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2507 * Check watermarks for an order-0 allocation request. If these
2508 * are not met, then a high-order request also cannot go ahead
2509 * even if a suitable page happened to be free.
2511 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2514 /* If this is an order-0 request then the watermark is fine */
2518 /* For a high-order request, check at least one suitable page is free */
2519 for (o = order; o < MAX_ORDER; o++) {
2520 struct free_area *area = &z->free_area[o];
2529 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2530 if (!list_empty(&area->free_list[mt]))
2535 if ((alloc_flags & ALLOC_CMA) &&
2536 !list_empty(&area->free_list[MIGRATE_CMA])) {
2544 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2545 int classzone_idx, int alloc_flags)
2547 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2548 zone_page_state(z, NR_FREE_PAGES));
2551 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2552 unsigned long mark, int classzone_idx)
2554 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2556 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2557 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2559 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2564 static bool zone_local(struct zone *local_zone, struct zone *zone)
2566 return local_zone->node == zone->node;
2569 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2571 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2574 #else /* CONFIG_NUMA */
2575 static bool zone_local(struct zone *local_zone, struct zone *zone)
2580 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2584 #endif /* CONFIG_NUMA */
2586 static void reset_alloc_batches(struct zone *preferred_zone)
2588 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2591 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2592 high_wmark_pages(zone) - low_wmark_pages(zone) -
2593 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2594 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2595 } while (zone++ != preferred_zone);
2599 * get_page_from_freelist goes through the zonelist trying to allocate
2602 static struct page *
2603 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2604 const struct alloc_context *ac)
2606 struct zonelist *zonelist = ac->zonelist;
2608 struct page *page = NULL;
2610 int nr_fair_skipped = 0;
2611 bool zonelist_rescan;
2614 zonelist_rescan = false;
2617 * Scan zonelist, looking for a zone with enough free.
2618 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2620 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2624 if (cpusets_enabled() &&
2625 (alloc_flags & ALLOC_CPUSET) &&
2626 !cpuset_zone_allowed(zone, gfp_mask))
2629 * Distribute pages in proportion to the individual
2630 * zone size to ensure fair page aging. The zone a
2631 * page was allocated in should have no effect on the
2632 * time the page has in memory before being reclaimed.
2634 if (alloc_flags & ALLOC_FAIR) {
2635 if (!zone_local(ac->preferred_zone, zone))
2637 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2643 * When allocating a page cache page for writing, we
2644 * want to get it from a zone that is within its dirty
2645 * limit, such that no single zone holds more than its
2646 * proportional share of globally allowed dirty pages.
2647 * The dirty limits take into account the zone's
2648 * lowmem reserves and high watermark so that kswapd
2649 * should be able to balance it without having to
2650 * write pages from its LRU list.
2652 * This may look like it could increase pressure on
2653 * lower zones by failing allocations in higher zones
2654 * before they are full. But the pages that do spill
2655 * over are limited as the lower zones are protected
2656 * by this very same mechanism. It should not become
2657 * a practical burden to them.
2659 * XXX: For now, allow allocations to potentially
2660 * exceed the per-zone dirty limit in the slowpath
2661 * (spread_dirty_pages unset) before going into reclaim,
2662 * which is important when on a NUMA setup the allowed
2663 * zones are together not big enough to reach the
2664 * global limit. The proper fix for these situations
2665 * will require awareness of zones in the
2666 * dirty-throttling and the flusher threads.
2668 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2671 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2672 if (!zone_watermark_ok(zone, order, mark,
2673 ac->classzone_idx, alloc_flags)) {
2676 /* Checked here to keep the fast path fast */
2677 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2678 if (alloc_flags & ALLOC_NO_WATERMARKS)
2681 if (zone_reclaim_mode == 0 ||
2682 !zone_allows_reclaim(ac->preferred_zone, zone))
2685 ret = zone_reclaim(zone, gfp_mask, order);
2687 case ZONE_RECLAIM_NOSCAN:
2690 case ZONE_RECLAIM_FULL:
2691 /* scanned but unreclaimable */
2694 /* did we reclaim enough */
2695 if (zone_watermark_ok(zone, order, mark,
2696 ac->classzone_idx, alloc_flags))
2704 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2705 gfp_mask, alloc_flags, ac->migratetype);
2707 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2711 * If this is a high-order atomic allocation then check
2712 * if the pageblock should be reserved for the future
2714 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2715 reserve_highatomic_pageblock(page, zone, order);
2722 * The first pass makes sure allocations are spread fairly within the
2723 * local node. However, the local node might have free pages left
2724 * after the fairness batches are exhausted, and remote zones haven't
2725 * even been considered yet. Try once more without fairness, and
2726 * include remote zones now, before entering the slowpath and waking
2727 * kswapd: prefer spilling to a remote zone over swapping locally.
2729 if (alloc_flags & ALLOC_FAIR) {
2730 alloc_flags &= ~ALLOC_FAIR;
2731 if (nr_fair_skipped) {
2732 zonelist_rescan = true;
2733 reset_alloc_batches(ac->preferred_zone);
2735 if (nr_online_nodes > 1)
2736 zonelist_rescan = true;
2739 if (zonelist_rescan)
2746 * Large machines with many possible nodes should not always dump per-node
2747 * meminfo in irq context.
2749 static inline bool should_suppress_show_mem(void)
2754 ret = in_interrupt();
2759 static DEFINE_RATELIMIT_STATE(nopage_rs,
2760 DEFAULT_RATELIMIT_INTERVAL,
2761 DEFAULT_RATELIMIT_BURST);
2763 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
2765 unsigned int filter = SHOW_MEM_FILTER_NODES;
2767 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2768 debug_guardpage_minorder() > 0)
2772 * This documents exceptions given to allocations in certain
2773 * contexts that are allowed to allocate outside current's set
2776 if (!(gfp_mask & __GFP_NOMEMALLOC))
2777 if (test_thread_flag(TIF_MEMDIE) ||
2778 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2779 filter &= ~SHOW_MEM_FILTER_NODES;
2780 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
2781 filter &= ~SHOW_MEM_FILTER_NODES;
2784 struct va_format vaf;
2787 va_start(args, fmt);
2792 pr_warn("%pV", &vaf);
2797 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2798 current->comm, order, gfp_mask, &gfp_mask);
2800 if (!should_suppress_show_mem())
2804 static inline struct page *
2805 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2806 const struct alloc_context *ac, unsigned long *did_some_progress)
2808 struct oom_control oc = {
2809 .zonelist = ac->zonelist,
2810 .nodemask = ac->nodemask,
2811 .gfp_mask = gfp_mask,
2816 *did_some_progress = 0;
2819 * Acquire the oom lock. If that fails, somebody else is
2820 * making progress for us.
2822 if (!mutex_trylock(&oom_lock)) {
2823 *did_some_progress = 1;
2824 schedule_timeout_uninterruptible(1);
2829 * Go through the zonelist yet one more time, keep very high watermark
2830 * here, this is only to catch a parallel oom killing, we must fail if
2831 * we're still under heavy pressure.
2833 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2834 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2838 if (!(gfp_mask & __GFP_NOFAIL)) {
2839 /* Coredumps can quickly deplete all memory reserves */
2840 if (current->flags & PF_DUMPCORE)
2842 /* The OOM killer will not help higher order allocs */
2843 if (order > PAGE_ALLOC_COSTLY_ORDER)
2845 /* The OOM killer does not needlessly kill tasks for lowmem */
2846 if (ac->high_zoneidx < ZONE_NORMAL)
2848 /* The OOM killer does not compensate for IO-less reclaim */
2849 if (!(gfp_mask & __GFP_FS)) {
2851 * XXX: Page reclaim didn't yield anything,
2852 * and the OOM killer can't be invoked, but
2853 * keep looping as per tradition.
2855 *did_some_progress = 1;
2858 if (pm_suspended_storage())
2860 /* The OOM killer may not free memory on a specific node */
2861 if (gfp_mask & __GFP_THISNODE)
2864 /* Exhausted what can be done so it's blamo time */
2865 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
2866 *did_some_progress = 1;
2868 if (gfp_mask & __GFP_NOFAIL) {
2869 page = get_page_from_freelist(gfp_mask, order,
2870 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
2872 * fallback to ignore cpuset restriction if our nodes
2876 page = get_page_from_freelist(gfp_mask, order,
2877 ALLOC_NO_WATERMARKS, ac);
2881 mutex_unlock(&oom_lock);
2885 #ifdef CONFIG_COMPACTION
2886 /* Try memory compaction for high-order allocations before reclaim */
2887 static struct page *
2888 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2889 int alloc_flags, const struct alloc_context *ac,
2890 enum migrate_mode mode, int *contended_compaction,
2891 bool *deferred_compaction)
2893 unsigned long compact_result;
2899 current->flags |= PF_MEMALLOC;
2900 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2901 mode, contended_compaction);
2902 current->flags &= ~PF_MEMALLOC;
2904 switch (compact_result) {
2905 case COMPACT_DEFERRED:
2906 *deferred_compaction = true;
2908 case COMPACT_SKIPPED:
2915 * At least in one zone compaction wasn't deferred or skipped, so let's
2916 * count a compaction stall
2918 count_vm_event(COMPACTSTALL);
2920 page = get_page_from_freelist(gfp_mask, order,
2921 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2924 struct zone *zone = page_zone(page);
2926 zone->compact_blockskip_flush = false;
2927 compaction_defer_reset(zone, order, true);
2928 count_vm_event(COMPACTSUCCESS);
2933 * It's bad if compaction run occurs and fails. The most likely reason
2934 * is that pages exist, but not enough to satisfy watermarks.
2936 count_vm_event(COMPACTFAIL);
2943 static inline struct page *
2944 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2945 int alloc_flags, const struct alloc_context *ac,
2946 enum migrate_mode mode, int *contended_compaction,
2947 bool *deferred_compaction)
2951 #endif /* CONFIG_COMPACTION */
2953 /* Perform direct synchronous page reclaim */
2955 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
2956 const struct alloc_context *ac)
2958 struct reclaim_state reclaim_state;
2963 /* We now go into synchronous reclaim */
2964 cpuset_memory_pressure_bump();
2965 current->flags |= PF_MEMALLOC;
2966 lockdep_set_current_reclaim_state(gfp_mask);
2967 reclaim_state.reclaimed_slab = 0;
2968 current->reclaim_state = &reclaim_state;
2970 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
2973 current->reclaim_state = NULL;
2974 lockdep_clear_current_reclaim_state();
2975 current->flags &= ~PF_MEMALLOC;
2982 /* The really slow allocator path where we enter direct reclaim */
2983 static inline struct page *
2984 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2985 int alloc_flags, const struct alloc_context *ac,
2986 unsigned long *did_some_progress)
2988 struct page *page = NULL;
2989 bool drained = false;
2991 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
2992 if (unlikely(!(*did_some_progress)))
2996 page = get_page_from_freelist(gfp_mask, order,
2997 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3000 * If an allocation failed after direct reclaim, it could be because
3001 * pages are pinned on the per-cpu lists or in high alloc reserves.
3002 * Shrink them them and try again
3004 if (!page && !drained) {
3005 unreserve_highatomic_pageblock(ac);
3006 drain_all_pages(NULL);
3014 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3019 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3020 ac->high_zoneidx, ac->nodemask)
3021 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
3025 gfp_to_alloc_flags(gfp_t gfp_mask)
3027 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3029 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3030 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3033 * The caller may dip into page reserves a bit more if the caller
3034 * cannot run direct reclaim, or if the caller has realtime scheduling
3035 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3036 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3038 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3040 if (gfp_mask & __GFP_ATOMIC) {
3042 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3043 * if it can't schedule.
3045 if (!(gfp_mask & __GFP_NOMEMALLOC))
3046 alloc_flags |= ALLOC_HARDER;
3048 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3049 * comment for __cpuset_node_allowed().
3051 alloc_flags &= ~ALLOC_CPUSET;
3052 } else if (unlikely(rt_task(current)) && !in_interrupt())
3053 alloc_flags |= ALLOC_HARDER;
3055 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3056 if (gfp_mask & __GFP_MEMALLOC)
3057 alloc_flags |= ALLOC_NO_WATERMARKS;
3058 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3059 alloc_flags |= ALLOC_NO_WATERMARKS;
3060 else if (!in_interrupt() &&
3061 ((current->flags & PF_MEMALLOC) ||
3062 unlikely(test_thread_flag(TIF_MEMDIE))))
3063 alloc_flags |= ALLOC_NO_WATERMARKS;
3066 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3067 alloc_flags |= ALLOC_CMA;
3072 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3074 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3077 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3079 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3082 static inline struct page *
3083 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3084 struct alloc_context *ac)
3086 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3087 struct page *page = NULL;
3089 unsigned long pages_reclaimed = 0;
3090 unsigned long did_some_progress;
3091 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3092 bool deferred_compaction = false;
3093 int contended_compaction = COMPACT_CONTENDED_NONE;
3096 * In the slowpath, we sanity check order to avoid ever trying to
3097 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3098 * be using allocators in order of preference for an area that is
3101 if (order >= MAX_ORDER) {
3102 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3107 * We also sanity check to catch abuse of atomic reserves being used by
3108 * callers that are not in atomic context.
3110 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3111 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3112 gfp_mask &= ~__GFP_ATOMIC;
3115 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3116 wake_all_kswapds(order, ac);
3119 * OK, we're below the kswapd watermark and have kicked background
3120 * reclaim. Now things get more complex, so set up alloc_flags according
3121 * to how we want to proceed.
3123 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3126 * Find the true preferred zone if the allocation is unconstrained by
3129 if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) {
3130 struct zoneref *preferred_zoneref;
3131 preferred_zoneref = first_zones_zonelist(ac->zonelist,
3132 ac->high_zoneidx, NULL, &ac->preferred_zone);
3133 ac->classzone_idx = zonelist_zone_idx(preferred_zoneref);
3136 /* This is the last chance, in general, before the goto nopage. */
3137 page = get_page_from_freelist(gfp_mask, order,
3138 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3142 /* Allocate without watermarks if the context allows */
3143 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3145 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3146 * the allocation is high priority and these type of
3147 * allocations are system rather than user orientated
3149 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3150 page = get_page_from_freelist(gfp_mask, order,
3151 ALLOC_NO_WATERMARKS, ac);
3156 /* Caller is not willing to reclaim, we can't balance anything */
3157 if (!can_direct_reclaim) {
3159 * All existing users of the __GFP_NOFAIL are blockable, so warn
3160 * of any new users that actually allow this type of allocation
3163 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3167 /* Avoid recursion of direct reclaim */
3168 if (current->flags & PF_MEMALLOC) {
3170 * __GFP_NOFAIL request from this context is rather bizarre
3171 * because we cannot reclaim anything and only can loop waiting
3172 * for somebody to do a work for us.
3174 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3181 /* Avoid allocations with no watermarks from looping endlessly */
3182 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3186 * Try direct compaction. The first pass is asynchronous. Subsequent
3187 * attempts after direct reclaim are synchronous
3189 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3191 &contended_compaction,
3192 &deferred_compaction);
3196 /* Checks for THP-specific high-order allocations */
3197 if (is_thp_gfp_mask(gfp_mask)) {
3199 * If compaction is deferred for high-order allocations, it is
3200 * because sync compaction recently failed. If this is the case
3201 * and the caller requested a THP allocation, we do not want
3202 * to heavily disrupt the system, so we fail the allocation
3203 * instead of entering direct reclaim.
3205 if (deferred_compaction)
3209 * In all zones where compaction was attempted (and not
3210 * deferred or skipped), lock contention has been detected.
3211 * For THP allocation we do not want to disrupt the others
3212 * so we fallback to base pages instead.
3214 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3218 * If compaction was aborted due to need_resched(), we do not
3219 * want to further increase allocation latency, unless it is
3220 * khugepaged trying to collapse.
3222 if (contended_compaction == COMPACT_CONTENDED_SCHED
3223 && !(current->flags & PF_KTHREAD))
3228 * It can become very expensive to allocate transparent hugepages at
3229 * fault, so use asynchronous memory compaction for THP unless it is
3230 * khugepaged trying to collapse.
3232 if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
3233 migration_mode = MIGRATE_SYNC_LIGHT;
3235 /* Try direct reclaim and then allocating */
3236 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3237 &did_some_progress);
3241 /* Do not loop if specifically requested */
3242 if (gfp_mask & __GFP_NORETRY)
3245 /* Keep reclaiming pages as long as there is reasonable progress */
3246 pages_reclaimed += did_some_progress;
3247 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3248 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3249 /* Wait for some write requests to complete then retry */
3250 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
3254 /* Reclaim has failed us, start killing things */
3255 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3259 /* Retry as long as the OOM killer is making progress */
3260 if (did_some_progress)
3265 * High-order allocations do not necessarily loop after
3266 * direct reclaim and reclaim/compaction depends on compaction
3267 * being called after reclaim so call directly if necessary
3269 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3271 &contended_compaction,
3272 &deferred_compaction);
3276 warn_alloc_failed(gfp_mask, order, NULL);
3282 * This is the 'heart' of the zoned buddy allocator.
3285 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3286 struct zonelist *zonelist, nodemask_t *nodemask)
3288 struct zoneref *preferred_zoneref;
3289 struct page *page = NULL;
3290 unsigned int cpuset_mems_cookie;
3291 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
3292 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
3293 struct alloc_context ac = {
3294 .high_zoneidx = gfp_zone(gfp_mask),
3295 .nodemask = nodemask,
3296 .migratetype = gfpflags_to_migratetype(gfp_mask),
3299 gfp_mask &= gfp_allowed_mask;
3301 lockdep_trace_alloc(gfp_mask);
3303 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3305 if (should_fail_alloc_page(gfp_mask, order))
3309 * Check the zones suitable for the gfp_mask contain at least one
3310 * valid zone. It's possible to have an empty zonelist as a result
3311 * of __GFP_THISNODE and a memoryless node
3313 if (unlikely(!zonelist->_zonerefs->zone))
3316 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3317 alloc_flags |= ALLOC_CMA;
3320 cpuset_mems_cookie = read_mems_allowed_begin();
3322 /* We set it here, as __alloc_pages_slowpath might have changed it */
3323 ac.zonelist = zonelist;
3325 /* Dirty zone balancing only done in the fast path */
3326 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3328 /* The preferred zone is used for statistics later */
3329 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
3330 ac.nodemask ? : &cpuset_current_mems_allowed,
3331 &ac.preferred_zone);
3332 if (!ac.preferred_zone)
3334 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
3336 /* First allocation attempt */
3337 alloc_mask = gfp_mask|__GFP_HARDWALL;
3338 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3339 if (unlikely(!page)) {
3341 * Runtime PM, block IO and its error handling path
3342 * can deadlock because I/O on the device might not
3345 alloc_mask = memalloc_noio_flags(gfp_mask);
3346 ac.spread_dirty_pages = false;
3348 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3351 if (kmemcheck_enabled && page)
3352 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3354 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3358 * When updating a task's mems_allowed, it is possible to race with
3359 * parallel threads in such a way that an allocation can fail while
3360 * the mask is being updated. If a page allocation is about to fail,
3361 * check if the cpuset changed during allocation and if so, retry.
3363 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
3368 EXPORT_SYMBOL(__alloc_pages_nodemask);
3371 * Common helper functions.
3373 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3378 * __get_free_pages() returns a 32-bit address, which cannot represent
3381 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3383 page = alloc_pages(gfp_mask, order);
3386 return (unsigned long) page_address(page);
3388 EXPORT_SYMBOL(__get_free_pages);
3390 unsigned long get_zeroed_page(gfp_t gfp_mask)
3392 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3394 EXPORT_SYMBOL(get_zeroed_page);
3396 void __free_pages(struct page *page, unsigned int order)
3398 if (put_page_testzero(page)) {
3400 free_hot_cold_page(page, false);
3402 __free_pages_ok(page, order);
3406 EXPORT_SYMBOL(__free_pages);
3408 void free_pages(unsigned long addr, unsigned int order)
3411 VM_BUG_ON(!virt_addr_valid((void *)addr));
3412 __free_pages(virt_to_page((void *)addr), order);
3416 EXPORT_SYMBOL(free_pages);
3420 * An arbitrary-length arbitrary-offset area of memory which resides
3421 * within a 0 or higher order page. Multiple fragments within that page
3422 * are individually refcounted, in the page's reference counter.
3424 * The page_frag functions below provide a simple allocation framework for
3425 * page fragments. This is used by the network stack and network device
3426 * drivers to provide a backing region of memory for use as either an
3427 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3429 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3432 struct page *page = NULL;
3433 gfp_t gfp = gfp_mask;
3435 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3436 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3438 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3439 PAGE_FRAG_CACHE_MAX_ORDER);
3440 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3442 if (unlikely(!page))
3443 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3445 nc->va = page ? page_address(page) : NULL;
3450 void *__alloc_page_frag(struct page_frag_cache *nc,
3451 unsigned int fragsz, gfp_t gfp_mask)
3453 unsigned int size = PAGE_SIZE;
3457 if (unlikely(!nc->va)) {
3459 page = __page_frag_refill(nc, gfp_mask);
3463 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3464 /* if size can vary use size else just use PAGE_SIZE */
3467 /* Even if we own the page, we do not use atomic_set().
3468 * This would break get_page_unless_zero() users.
3470 page_ref_add(page, size - 1);
3472 /* reset page count bias and offset to start of new frag */
3473 nc->pfmemalloc = page_is_pfmemalloc(page);
3474 nc->pagecnt_bias = size;
3478 offset = nc->offset - fragsz;
3479 if (unlikely(offset < 0)) {
3480 page = virt_to_page(nc->va);
3482 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3485 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3486 /* if size can vary use size else just use PAGE_SIZE */
3489 /* OK, page count is 0, we can safely set it */
3490 set_page_count(page, size);
3492 /* reset page count bias and offset to start of new frag */
3493 nc->pagecnt_bias = size;
3494 offset = size - fragsz;
3498 nc->offset = offset;
3500 return nc->va + offset;
3502 EXPORT_SYMBOL(__alloc_page_frag);
3505 * Frees a page fragment allocated out of either a compound or order 0 page.
3507 void __free_page_frag(void *addr)
3509 struct page *page = virt_to_head_page(addr);
3511 if (unlikely(put_page_testzero(page)))
3512 __free_pages_ok(page, compound_order(page));
3514 EXPORT_SYMBOL(__free_page_frag);
3517 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3518 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3519 * equivalent to alloc_pages.
3521 * It should be used when the caller would like to use kmalloc, but since the
3522 * allocation is large, it has to fall back to the page allocator.
3524 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3528 page = alloc_pages(gfp_mask, order);
3529 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3530 __free_pages(page, order);
3536 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3540 page = alloc_pages_node(nid, gfp_mask, order);
3541 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3542 __free_pages(page, order);
3549 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3552 void __free_kmem_pages(struct page *page, unsigned int order)
3554 memcg_kmem_uncharge(page, order);
3555 __free_pages(page, order);
3558 void free_kmem_pages(unsigned long addr, unsigned int order)
3561 VM_BUG_ON(!virt_addr_valid((void *)addr));
3562 __free_kmem_pages(virt_to_page((void *)addr), order);
3566 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3570 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3571 unsigned long used = addr + PAGE_ALIGN(size);
3573 split_page(virt_to_page((void *)addr), order);
3574 while (used < alloc_end) {
3579 return (void *)addr;
3583 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3584 * @size: the number of bytes to allocate
3585 * @gfp_mask: GFP flags for the allocation
3587 * This function is similar to alloc_pages(), except that it allocates the
3588 * minimum number of pages to satisfy the request. alloc_pages() can only
3589 * allocate memory in power-of-two pages.
3591 * This function is also limited by MAX_ORDER.
3593 * Memory allocated by this function must be released by free_pages_exact().
3595 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3597 unsigned int order = get_order(size);
3600 addr = __get_free_pages(gfp_mask, order);
3601 return make_alloc_exact(addr, order, size);
3603 EXPORT_SYMBOL(alloc_pages_exact);
3606 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3608 * @nid: the preferred node ID where memory should be allocated
3609 * @size: the number of bytes to allocate
3610 * @gfp_mask: GFP flags for the allocation
3612 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3615 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3617 unsigned int order = get_order(size);
3618 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3621 return make_alloc_exact((unsigned long)page_address(p), order, size);
3625 * free_pages_exact - release memory allocated via alloc_pages_exact()
3626 * @virt: the value returned by alloc_pages_exact.
3627 * @size: size of allocation, same value as passed to alloc_pages_exact().
3629 * Release the memory allocated by a previous call to alloc_pages_exact.
3631 void free_pages_exact(void *virt, size_t size)
3633 unsigned long addr = (unsigned long)virt;
3634 unsigned long end = addr + PAGE_ALIGN(size);
3636 while (addr < end) {
3641 EXPORT_SYMBOL(free_pages_exact);
3644 * nr_free_zone_pages - count number of pages beyond high watermark
3645 * @offset: The zone index of the highest zone
3647 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3648 * high watermark within all zones at or below a given zone index. For each
3649 * zone, the number of pages is calculated as:
3650 * managed_pages - high_pages
3652 static unsigned long nr_free_zone_pages(int offset)
3657 /* Just pick one node, since fallback list is circular */
3658 unsigned long sum = 0;
3660 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3662 for_each_zone_zonelist(zone, z, zonelist, offset) {
3663 unsigned long size = zone->managed_pages;
3664 unsigned long high = high_wmark_pages(zone);
3673 * nr_free_buffer_pages - count number of pages beyond high watermark
3675 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3676 * watermark within ZONE_DMA and ZONE_NORMAL.
3678 unsigned long nr_free_buffer_pages(void)
3680 return nr_free_zone_pages(gfp_zone(GFP_USER));
3682 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3685 * nr_free_pagecache_pages - count number of pages beyond high watermark
3687 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3688 * high watermark within all zones.
3690 unsigned long nr_free_pagecache_pages(void)
3692 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3695 static inline void show_node(struct zone *zone)
3697 if (IS_ENABLED(CONFIG_NUMA))
3698 printk("Node %d ", zone_to_nid(zone));
3701 long si_mem_available(void)
3704 unsigned long pagecache;
3705 unsigned long wmark_low = 0;
3706 unsigned long pages[NR_LRU_LISTS];
3710 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
3711 pages[lru] = global_page_state(NR_LRU_BASE + lru);
3714 wmark_low += zone->watermark[WMARK_LOW];
3717 * Estimate the amount of memory available for userspace allocations,
3718 * without causing swapping.
3720 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
3723 * Not all the page cache can be freed, otherwise the system will
3724 * start swapping. Assume at least half of the page cache, or the
3725 * low watermark worth of cache, needs to stay.
3727 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
3728 pagecache -= min(pagecache / 2, wmark_low);
3729 available += pagecache;
3732 * Part of the reclaimable slab consists of items that are in use,
3733 * and cannot be freed. Cap this estimate at the low watermark.
3735 available += global_page_state(NR_SLAB_RECLAIMABLE) -
3736 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
3742 EXPORT_SYMBOL_GPL(si_mem_available);
3744 void si_meminfo(struct sysinfo *val)
3746 val->totalram = totalram_pages;
3747 val->sharedram = global_page_state(NR_SHMEM);
3748 val->freeram = global_page_state(NR_FREE_PAGES);
3749 val->bufferram = nr_blockdev_pages();
3750 val->totalhigh = totalhigh_pages;
3751 val->freehigh = nr_free_highpages();
3752 val->mem_unit = PAGE_SIZE;
3755 EXPORT_SYMBOL(si_meminfo);
3758 void si_meminfo_node(struct sysinfo *val, int nid)
3760 int zone_type; /* needs to be signed */
3761 unsigned long managed_pages = 0;
3762 pg_data_t *pgdat = NODE_DATA(nid);
3764 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3765 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3766 val->totalram = managed_pages;
3767 val->sharedram = node_page_state(nid, NR_SHMEM);
3768 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3769 #ifdef CONFIG_HIGHMEM
3770 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3771 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3777 val->mem_unit = PAGE_SIZE;
3782 * Determine whether the node should be displayed or not, depending on whether
3783 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3785 bool skip_free_areas_node(unsigned int flags, int nid)
3788 unsigned int cpuset_mems_cookie;
3790 if (!(flags & SHOW_MEM_FILTER_NODES))
3794 cpuset_mems_cookie = read_mems_allowed_begin();
3795 ret = !node_isset(nid, cpuset_current_mems_allowed);
3796 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3801 #define K(x) ((x) << (PAGE_SHIFT-10))
3803 static void show_migration_types(unsigned char type)
3805 static const char types[MIGRATE_TYPES] = {
3806 [MIGRATE_UNMOVABLE] = 'U',
3807 [MIGRATE_MOVABLE] = 'M',
3808 [MIGRATE_RECLAIMABLE] = 'E',
3809 [MIGRATE_HIGHATOMIC] = 'H',
3811 [MIGRATE_CMA] = 'C',
3813 #ifdef CONFIG_MEMORY_ISOLATION
3814 [MIGRATE_ISOLATE] = 'I',
3817 char tmp[MIGRATE_TYPES + 1];
3821 for (i = 0; i < MIGRATE_TYPES; i++) {
3822 if (type & (1 << i))
3827 printk("(%s) ", tmp);
3831 * Show free area list (used inside shift_scroll-lock stuff)
3832 * We also calculate the percentage fragmentation. We do this by counting the
3833 * memory on each free list with the exception of the first item on the list.
3836 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3839 void show_free_areas(unsigned int filter)
3841 unsigned long free_pcp = 0;
3845 for_each_populated_zone(zone) {
3846 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3849 for_each_online_cpu(cpu)
3850 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3853 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3854 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3855 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3856 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3857 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3858 " free:%lu free_pcp:%lu free_cma:%lu\n",
3859 global_page_state(NR_ACTIVE_ANON),
3860 global_page_state(NR_INACTIVE_ANON),
3861 global_page_state(NR_ISOLATED_ANON),
3862 global_page_state(NR_ACTIVE_FILE),
3863 global_page_state(NR_INACTIVE_FILE),
3864 global_page_state(NR_ISOLATED_FILE),
3865 global_page_state(NR_UNEVICTABLE),
3866 global_page_state(NR_FILE_DIRTY),
3867 global_page_state(NR_WRITEBACK),
3868 global_page_state(NR_UNSTABLE_NFS),
3869 global_page_state(NR_SLAB_RECLAIMABLE),
3870 global_page_state(NR_SLAB_UNRECLAIMABLE),
3871 global_page_state(NR_FILE_MAPPED),
3872 global_page_state(NR_SHMEM),
3873 global_page_state(NR_PAGETABLE),
3874 global_page_state(NR_BOUNCE),
3875 global_page_state(NR_FREE_PAGES),
3877 global_page_state(NR_FREE_CMA_PAGES));
3879 for_each_populated_zone(zone) {
3882 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3886 for_each_online_cpu(cpu)
3887 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3895 " active_anon:%lukB"
3896 " inactive_anon:%lukB"
3897 " active_file:%lukB"
3898 " inactive_file:%lukB"
3899 " unevictable:%lukB"
3900 " isolated(anon):%lukB"
3901 " isolated(file):%lukB"
3909 " slab_reclaimable:%lukB"
3910 " slab_unreclaimable:%lukB"
3911 " kernel_stack:%lukB"
3918 " writeback_tmp:%lukB"
3919 " pages_scanned:%lu"
3920 " all_unreclaimable? %s"
3923 K(zone_page_state(zone, NR_FREE_PAGES)),
3924 K(min_wmark_pages(zone)),
3925 K(low_wmark_pages(zone)),
3926 K(high_wmark_pages(zone)),
3927 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3928 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3929 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3930 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3931 K(zone_page_state(zone, NR_UNEVICTABLE)),
3932 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3933 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3934 K(zone->present_pages),
3935 K(zone->managed_pages),
3936 K(zone_page_state(zone, NR_MLOCK)),
3937 K(zone_page_state(zone, NR_FILE_DIRTY)),
3938 K(zone_page_state(zone, NR_WRITEBACK)),
3939 K(zone_page_state(zone, NR_FILE_MAPPED)),
3940 K(zone_page_state(zone, NR_SHMEM)),
3941 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3942 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3943 zone_page_state(zone, NR_KERNEL_STACK) *
3945 K(zone_page_state(zone, NR_PAGETABLE)),
3946 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3947 K(zone_page_state(zone, NR_BOUNCE)),
3949 K(this_cpu_read(zone->pageset->pcp.count)),
3950 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3951 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3952 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3953 (!zone_reclaimable(zone) ? "yes" : "no")
3955 printk("lowmem_reserve[]:");
3956 for (i = 0; i < MAX_NR_ZONES; i++)
3957 printk(" %ld", zone->lowmem_reserve[i]);
3961 for_each_populated_zone(zone) {
3963 unsigned long nr[MAX_ORDER], flags, total = 0;
3964 unsigned char types[MAX_ORDER];
3966 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3969 printk("%s: ", zone->name);
3971 spin_lock_irqsave(&zone->lock, flags);
3972 for (order = 0; order < MAX_ORDER; order++) {
3973 struct free_area *area = &zone->free_area[order];
3976 nr[order] = area->nr_free;
3977 total += nr[order] << order;
3980 for (type = 0; type < MIGRATE_TYPES; type++) {
3981 if (!list_empty(&area->free_list[type]))
3982 types[order] |= 1 << type;
3985 spin_unlock_irqrestore(&zone->lock, flags);
3986 for (order = 0; order < MAX_ORDER; order++) {
3987 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3989 show_migration_types(types[order]);
3991 printk("= %lukB\n", K(total));
3994 hugetlb_show_meminfo();
3996 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3998 show_swap_cache_info();
4001 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4003 zoneref->zone = zone;
4004 zoneref->zone_idx = zone_idx(zone);
4008 * Builds allocation fallback zone lists.
4010 * Add all populated zones of a node to the zonelist.
4012 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4016 enum zone_type zone_type = MAX_NR_ZONES;
4020 zone = pgdat->node_zones + zone_type;
4021 if (populated_zone(zone)) {
4022 zoneref_set_zone(zone,
4023 &zonelist->_zonerefs[nr_zones++]);
4024 check_highest_zone(zone_type);
4026 } while (zone_type);
4034 * 0 = automatic detection of better ordering.
4035 * 1 = order by ([node] distance, -zonetype)
4036 * 2 = order by (-zonetype, [node] distance)
4038 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4039 * the same zonelist. So only NUMA can configure this param.
4041 #define ZONELIST_ORDER_DEFAULT 0
4042 #define ZONELIST_ORDER_NODE 1
4043 #define ZONELIST_ORDER_ZONE 2
4045 /* zonelist order in the kernel.
4046 * set_zonelist_order() will set this to NODE or ZONE.
4048 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4049 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4053 /* The value user specified ....changed by config */
4054 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4055 /* string for sysctl */
4056 #define NUMA_ZONELIST_ORDER_LEN 16
4057 char numa_zonelist_order[16] = "default";
4060 * interface for configure zonelist ordering.
4061 * command line option "numa_zonelist_order"
4062 * = "[dD]efault - default, automatic configuration.
4063 * = "[nN]ode - order by node locality, then by zone within node
4064 * = "[zZ]one - order by zone, then by locality within zone
4067 static int __parse_numa_zonelist_order(char *s)
4069 if (*s == 'd' || *s == 'D') {
4070 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4071 } else if (*s == 'n' || *s == 'N') {
4072 user_zonelist_order = ZONELIST_ORDER_NODE;
4073 } else if (*s == 'z' || *s == 'Z') {
4074 user_zonelist_order = ZONELIST_ORDER_ZONE;
4076 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4082 static __init int setup_numa_zonelist_order(char *s)
4089 ret = __parse_numa_zonelist_order(s);
4091 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4095 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4098 * sysctl handler for numa_zonelist_order
4100 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4101 void __user *buffer, size_t *length,
4104 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4106 static DEFINE_MUTEX(zl_order_mutex);
4108 mutex_lock(&zl_order_mutex);
4110 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4114 strcpy(saved_string, (char *)table->data);
4116 ret = proc_dostring(table, write, buffer, length, ppos);
4120 int oldval = user_zonelist_order;
4122 ret = __parse_numa_zonelist_order((char *)table->data);
4125 * bogus value. restore saved string
4127 strncpy((char *)table->data, saved_string,
4128 NUMA_ZONELIST_ORDER_LEN);
4129 user_zonelist_order = oldval;
4130 } else if (oldval != user_zonelist_order) {
4131 mutex_lock(&zonelists_mutex);
4132 build_all_zonelists(NULL, NULL);
4133 mutex_unlock(&zonelists_mutex);
4137 mutex_unlock(&zl_order_mutex);
4142 #define MAX_NODE_LOAD (nr_online_nodes)
4143 static int node_load[MAX_NUMNODES];
4146 * find_next_best_node - find the next node that should appear in a given node's fallback list
4147 * @node: node whose fallback list we're appending
4148 * @used_node_mask: nodemask_t of already used nodes
4150 * We use a number of factors to determine which is the next node that should
4151 * appear on a given node's fallback list. The node should not have appeared
4152 * already in @node's fallback list, and it should be the next closest node
4153 * according to the distance array (which contains arbitrary distance values
4154 * from each node to each node in the system), and should also prefer nodes
4155 * with no CPUs, since presumably they'll have very little allocation pressure
4156 * on them otherwise.
4157 * It returns -1 if no node is found.
4159 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4162 int min_val = INT_MAX;
4163 int best_node = NUMA_NO_NODE;
4164 const struct cpumask *tmp = cpumask_of_node(0);
4166 /* Use the local node if we haven't already */
4167 if (!node_isset(node, *used_node_mask)) {
4168 node_set(node, *used_node_mask);
4172 for_each_node_state(n, N_MEMORY) {
4174 /* Don't want a node to appear more than once */
4175 if (node_isset(n, *used_node_mask))
4178 /* Use the distance array to find the distance */
4179 val = node_distance(node, n);
4181 /* Penalize nodes under us ("prefer the next node") */
4184 /* Give preference to headless and unused nodes */
4185 tmp = cpumask_of_node(n);
4186 if (!cpumask_empty(tmp))
4187 val += PENALTY_FOR_NODE_WITH_CPUS;
4189 /* Slight preference for less loaded node */
4190 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4191 val += node_load[n];
4193 if (val < min_val) {
4200 node_set(best_node, *used_node_mask);
4207 * Build zonelists ordered by node and zones within node.
4208 * This results in maximum locality--normal zone overflows into local
4209 * DMA zone, if any--but risks exhausting DMA zone.
4211 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4214 struct zonelist *zonelist;
4216 zonelist = &pgdat->node_zonelists[0];
4217 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4219 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4220 zonelist->_zonerefs[j].zone = NULL;
4221 zonelist->_zonerefs[j].zone_idx = 0;
4225 * Build gfp_thisnode zonelists
4227 static void build_thisnode_zonelists(pg_data_t *pgdat)
4230 struct zonelist *zonelist;
4232 zonelist = &pgdat->node_zonelists[1];
4233 j = build_zonelists_node(pgdat, zonelist, 0);
4234 zonelist->_zonerefs[j].zone = NULL;
4235 zonelist->_zonerefs[j].zone_idx = 0;
4239 * Build zonelists ordered by zone and nodes within zones.
4240 * This results in conserving DMA zone[s] until all Normal memory is
4241 * exhausted, but results in overflowing to remote node while memory
4242 * may still exist in local DMA zone.
4244 static int node_order[MAX_NUMNODES];
4246 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4249 int zone_type; /* needs to be signed */
4251 struct zonelist *zonelist;
4253 zonelist = &pgdat->node_zonelists[0];
4255 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4256 for (j = 0; j < nr_nodes; j++) {
4257 node = node_order[j];
4258 z = &NODE_DATA(node)->node_zones[zone_type];
4259 if (populated_zone(z)) {
4261 &zonelist->_zonerefs[pos++]);
4262 check_highest_zone(zone_type);
4266 zonelist->_zonerefs[pos].zone = NULL;
4267 zonelist->_zonerefs[pos].zone_idx = 0;
4270 #if defined(CONFIG_64BIT)
4272 * Devices that require DMA32/DMA are relatively rare and do not justify a
4273 * penalty to every machine in case the specialised case applies. Default
4274 * to Node-ordering on 64-bit NUMA machines
4276 static int default_zonelist_order(void)
4278 return ZONELIST_ORDER_NODE;
4282 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4283 * by the kernel. If processes running on node 0 deplete the low memory zone
4284 * then reclaim will occur more frequency increasing stalls and potentially
4285 * be easier to OOM if a large percentage of the zone is under writeback or
4286 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4287 * Hence, default to zone ordering on 32-bit.
4289 static int default_zonelist_order(void)
4291 return ZONELIST_ORDER_ZONE;
4293 #endif /* CONFIG_64BIT */
4295 static void set_zonelist_order(void)
4297 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4298 current_zonelist_order = default_zonelist_order();
4300 current_zonelist_order = user_zonelist_order;
4303 static void build_zonelists(pg_data_t *pgdat)
4306 nodemask_t used_mask;
4307 int local_node, prev_node;
4308 struct zonelist *zonelist;
4309 unsigned int order = current_zonelist_order;
4311 /* initialize zonelists */
4312 for (i = 0; i < MAX_ZONELISTS; i++) {
4313 zonelist = pgdat->node_zonelists + i;
4314 zonelist->_zonerefs[0].zone = NULL;
4315 zonelist->_zonerefs[0].zone_idx = 0;
4318 /* NUMA-aware ordering of nodes */
4319 local_node = pgdat->node_id;
4320 load = nr_online_nodes;
4321 prev_node = local_node;
4322 nodes_clear(used_mask);
4324 memset(node_order, 0, sizeof(node_order));
4327 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4329 * We don't want to pressure a particular node.
4330 * So adding penalty to the first node in same
4331 * distance group to make it round-robin.
4333 if (node_distance(local_node, node) !=
4334 node_distance(local_node, prev_node))
4335 node_load[node] = load;
4339 if (order == ZONELIST_ORDER_NODE)
4340 build_zonelists_in_node_order(pgdat, node);
4342 node_order[i++] = node; /* remember order */
4345 if (order == ZONELIST_ORDER_ZONE) {
4346 /* calculate node order -- i.e., DMA last! */
4347 build_zonelists_in_zone_order(pgdat, i);
4350 build_thisnode_zonelists(pgdat);
4353 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4355 * Return node id of node used for "local" allocations.
4356 * I.e., first node id of first zone in arg node's generic zonelist.
4357 * Used for initializing percpu 'numa_mem', which is used primarily
4358 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4360 int local_memory_node(int node)
4364 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4365 gfp_zone(GFP_KERNEL),
4372 #else /* CONFIG_NUMA */
4374 static void set_zonelist_order(void)
4376 current_zonelist_order = ZONELIST_ORDER_ZONE;
4379 static void build_zonelists(pg_data_t *pgdat)
4381 int node, local_node;
4383 struct zonelist *zonelist;
4385 local_node = pgdat->node_id;
4387 zonelist = &pgdat->node_zonelists[0];
4388 j = build_zonelists_node(pgdat, zonelist, 0);
4391 * Now we build the zonelist so that it contains the zones
4392 * of all the other nodes.
4393 * We don't want to pressure a particular node, so when
4394 * building the zones for node N, we make sure that the
4395 * zones coming right after the local ones are those from
4396 * node N+1 (modulo N)
4398 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4399 if (!node_online(node))
4401 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4403 for (node = 0; node < local_node; node++) {
4404 if (!node_online(node))
4406 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4409 zonelist->_zonerefs[j].zone = NULL;
4410 zonelist->_zonerefs[j].zone_idx = 0;
4413 #endif /* CONFIG_NUMA */
4416 * Boot pageset table. One per cpu which is going to be used for all
4417 * zones and all nodes. The parameters will be set in such a way
4418 * that an item put on a list will immediately be handed over to
4419 * the buddy list. This is safe since pageset manipulation is done
4420 * with interrupts disabled.
4422 * The boot_pagesets must be kept even after bootup is complete for
4423 * unused processors and/or zones. They do play a role for bootstrapping
4424 * hotplugged processors.
4426 * zoneinfo_show() and maybe other functions do
4427 * not check if the processor is online before following the pageset pointer.
4428 * Other parts of the kernel may not check if the zone is available.
4430 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4431 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4432 static void setup_zone_pageset(struct zone *zone);
4435 * Global mutex to protect against size modification of zonelists
4436 * as well as to serialize pageset setup for the new populated zone.
4438 DEFINE_MUTEX(zonelists_mutex);
4440 /* return values int ....just for stop_machine() */
4441 static int __build_all_zonelists(void *data)
4445 pg_data_t *self = data;
4448 memset(node_load, 0, sizeof(node_load));
4451 if (self && !node_online(self->node_id)) {
4452 build_zonelists(self);
4455 for_each_online_node(nid) {
4456 pg_data_t *pgdat = NODE_DATA(nid);
4458 build_zonelists(pgdat);
4462 * Initialize the boot_pagesets that are going to be used
4463 * for bootstrapping processors. The real pagesets for
4464 * each zone will be allocated later when the per cpu
4465 * allocator is available.
4467 * boot_pagesets are used also for bootstrapping offline
4468 * cpus if the system is already booted because the pagesets
4469 * are needed to initialize allocators on a specific cpu too.
4470 * F.e. the percpu allocator needs the page allocator which
4471 * needs the percpu allocator in order to allocate its pagesets
4472 * (a chicken-egg dilemma).
4474 for_each_possible_cpu(cpu) {
4475 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4477 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4479 * We now know the "local memory node" for each node--
4480 * i.e., the node of the first zone in the generic zonelist.
4481 * Set up numa_mem percpu variable for on-line cpus. During
4482 * boot, only the boot cpu should be on-line; we'll init the
4483 * secondary cpus' numa_mem as they come on-line. During
4484 * node/memory hotplug, we'll fixup all on-line cpus.
4486 if (cpu_online(cpu))
4487 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4494 static noinline void __init
4495 build_all_zonelists_init(void)
4497 __build_all_zonelists(NULL);
4498 mminit_verify_zonelist();
4499 cpuset_init_current_mems_allowed();
4503 * Called with zonelists_mutex held always
4504 * unless system_state == SYSTEM_BOOTING.
4506 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4507 * [we're only called with non-NULL zone through __meminit paths] and
4508 * (2) call of __init annotated helper build_all_zonelists_init
4509 * [protected by SYSTEM_BOOTING].
4511 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4513 set_zonelist_order();
4515 if (system_state == SYSTEM_BOOTING) {
4516 build_all_zonelists_init();
4518 #ifdef CONFIG_MEMORY_HOTPLUG
4520 setup_zone_pageset(zone);
4522 /* we have to stop all cpus to guarantee there is no user
4524 stop_machine(__build_all_zonelists, pgdat, NULL);
4525 /* cpuset refresh routine should be here */
4527 vm_total_pages = nr_free_pagecache_pages();
4529 * Disable grouping by mobility if the number of pages in the
4530 * system is too low to allow the mechanism to work. It would be
4531 * more accurate, but expensive to check per-zone. This check is
4532 * made on memory-hotadd so a system can start with mobility
4533 * disabled and enable it later
4535 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4536 page_group_by_mobility_disabled = 1;
4538 page_group_by_mobility_disabled = 0;
4540 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4542 zonelist_order_name[current_zonelist_order],
4543 page_group_by_mobility_disabled ? "off" : "on",
4546 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4551 * Helper functions to size the waitqueue hash table.
4552 * Essentially these want to choose hash table sizes sufficiently
4553 * large so that collisions trying to wait on pages are rare.
4554 * But in fact, the number of active page waitqueues on typical
4555 * systems is ridiculously low, less than 200. So this is even
4556 * conservative, even though it seems large.
4558 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4559 * waitqueues, i.e. the size of the waitq table given the number of pages.
4561 #define PAGES_PER_WAITQUEUE 256
4563 #ifndef CONFIG_MEMORY_HOTPLUG
4564 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4566 unsigned long size = 1;
4568 pages /= PAGES_PER_WAITQUEUE;
4570 while (size < pages)
4574 * Once we have dozens or even hundreds of threads sleeping
4575 * on IO we've got bigger problems than wait queue collision.
4576 * Limit the size of the wait table to a reasonable size.
4578 size = min(size, 4096UL);
4580 return max(size, 4UL);
4584 * A zone's size might be changed by hot-add, so it is not possible to determine
4585 * a suitable size for its wait_table. So we use the maximum size now.
4587 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4589 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4590 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4591 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4593 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4594 * or more by the traditional way. (See above). It equals:
4596 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4597 * ia64(16K page size) : = ( 8G + 4M)byte.
4598 * powerpc (64K page size) : = (32G +16M)byte.
4600 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4607 * This is an integer logarithm so that shifts can be used later
4608 * to extract the more random high bits from the multiplicative
4609 * hash function before the remainder is taken.
4611 static inline unsigned long wait_table_bits(unsigned long size)
4617 * Initially all pages are reserved - free ones are freed
4618 * up by free_all_bootmem() once the early boot process is
4619 * done. Non-atomic initialization, single-pass.
4621 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4622 unsigned long start_pfn, enum memmap_context context)
4624 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
4625 unsigned long end_pfn = start_pfn + size;
4626 pg_data_t *pgdat = NODE_DATA(nid);
4628 unsigned long nr_initialised = 0;
4629 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4630 struct memblock_region *r = NULL, *tmp;
4633 if (highest_memmap_pfn < end_pfn - 1)
4634 highest_memmap_pfn = end_pfn - 1;
4637 * Honor reservation requested by the driver for this ZONE_DEVICE
4640 if (altmap && start_pfn == altmap->base_pfn)
4641 start_pfn += altmap->reserve;
4643 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4645 * There can be holes in boot-time mem_map[]s handed to this
4646 * function. They do not exist on hotplugged memory.
4648 if (context != MEMMAP_EARLY)
4651 if (!early_pfn_valid(pfn))
4653 if (!early_pfn_in_nid(pfn, nid))
4655 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
4658 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4660 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4661 * from zone_movable_pfn[nid] to end of each node should be
4662 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4664 if (!mirrored_kernelcore && zone_movable_pfn[nid])
4665 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
4669 * Check given memblock attribute by firmware which can affect
4670 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4671 * mirrored, it's an overlapped memmap init. skip it.
4673 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
4674 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
4675 for_each_memblock(memory, tmp)
4676 if (pfn < memblock_region_memory_end_pfn(tmp))
4680 if (pfn >= memblock_region_memory_base_pfn(r) &&
4681 memblock_is_mirror(r)) {
4682 /* already initialized as NORMAL */
4683 pfn = memblock_region_memory_end_pfn(r);
4691 * Mark the block movable so that blocks are reserved for
4692 * movable at startup. This will force kernel allocations
4693 * to reserve their blocks rather than leaking throughout
4694 * the address space during boot when many long-lived
4695 * kernel allocations are made.
4697 * bitmap is created for zone's valid pfn range. but memmap
4698 * can be created for invalid pages (for alignment)
4699 * check here not to call set_pageblock_migratetype() against
4702 if (!(pfn & (pageblock_nr_pages - 1))) {
4703 struct page *page = pfn_to_page(pfn);
4705 __init_single_page(page, pfn, zone, nid);
4706 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4708 __init_single_pfn(pfn, zone, nid);
4713 static void __meminit zone_init_free_lists(struct zone *zone)
4715 unsigned int order, t;
4716 for_each_migratetype_order(order, t) {
4717 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4718 zone->free_area[order].nr_free = 0;
4722 #ifndef __HAVE_ARCH_MEMMAP_INIT
4723 #define memmap_init(size, nid, zone, start_pfn) \
4724 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4727 static int zone_batchsize(struct zone *zone)
4733 * The per-cpu-pages pools are set to around 1000th of the
4734 * size of the zone. But no more than 1/2 of a meg.
4736 * OK, so we don't know how big the cache is. So guess.
4738 batch = zone->managed_pages / 1024;
4739 if (batch * PAGE_SIZE > 512 * 1024)
4740 batch = (512 * 1024) / PAGE_SIZE;
4741 batch /= 4; /* We effectively *= 4 below */
4746 * Clamp the batch to a 2^n - 1 value. Having a power
4747 * of 2 value was found to be more likely to have
4748 * suboptimal cache aliasing properties in some cases.
4750 * For example if 2 tasks are alternately allocating
4751 * batches of pages, one task can end up with a lot
4752 * of pages of one half of the possible page colors
4753 * and the other with pages of the other colors.
4755 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4760 /* The deferral and batching of frees should be suppressed under NOMMU
4763 * The problem is that NOMMU needs to be able to allocate large chunks
4764 * of contiguous memory as there's no hardware page translation to
4765 * assemble apparent contiguous memory from discontiguous pages.
4767 * Queueing large contiguous runs of pages for batching, however,
4768 * causes the pages to actually be freed in smaller chunks. As there
4769 * can be a significant delay between the individual batches being
4770 * recycled, this leads to the once large chunks of space being
4771 * fragmented and becoming unavailable for high-order allocations.
4778 * pcp->high and pcp->batch values are related and dependent on one another:
4779 * ->batch must never be higher then ->high.
4780 * The following function updates them in a safe manner without read side
4783 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4784 * those fields changing asynchronously (acording the the above rule).
4786 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4787 * outside of boot time (or some other assurance that no concurrent updaters
4790 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4791 unsigned long batch)
4793 /* start with a fail safe value for batch */
4797 /* Update high, then batch, in order */
4804 /* a companion to pageset_set_high() */
4805 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4807 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4810 static void pageset_init(struct per_cpu_pageset *p)
4812 struct per_cpu_pages *pcp;
4815 memset(p, 0, sizeof(*p));
4819 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4820 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4823 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4826 pageset_set_batch(p, batch);
4830 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4831 * to the value high for the pageset p.
4833 static void pageset_set_high(struct per_cpu_pageset *p,
4836 unsigned long batch = max(1UL, high / 4);
4837 if ((high / 4) > (PAGE_SHIFT * 8))
4838 batch = PAGE_SHIFT * 8;
4840 pageset_update(&p->pcp, high, batch);
4843 static void pageset_set_high_and_batch(struct zone *zone,
4844 struct per_cpu_pageset *pcp)
4846 if (percpu_pagelist_fraction)
4847 pageset_set_high(pcp,
4848 (zone->managed_pages /
4849 percpu_pagelist_fraction));
4851 pageset_set_batch(pcp, zone_batchsize(zone));
4854 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4856 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4859 pageset_set_high_and_batch(zone, pcp);
4862 static void __meminit setup_zone_pageset(struct zone *zone)
4865 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4866 for_each_possible_cpu(cpu)
4867 zone_pageset_init(zone, cpu);
4871 * Allocate per cpu pagesets and initialize them.
4872 * Before this call only boot pagesets were available.
4874 void __init setup_per_cpu_pageset(void)
4878 for_each_populated_zone(zone)
4879 setup_zone_pageset(zone);
4882 static noinline __init_refok
4883 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4889 * The per-page waitqueue mechanism uses hashed waitqueues
4892 zone->wait_table_hash_nr_entries =
4893 wait_table_hash_nr_entries(zone_size_pages);
4894 zone->wait_table_bits =
4895 wait_table_bits(zone->wait_table_hash_nr_entries);
4896 alloc_size = zone->wait_table_hash_nr_entries
4897 * sizeof(wait_queue_head_t);
4899 if (!slab_is_available()) {
4900 zone->wait_table = (wait_queue_head_t *)
4901 memblock_virt_alloc_node_nopanic(
4902 alloc_size, zone->zone_pgdat->node_id);
4905 * This case means that a zone whose size was 0 gets new memory
4906 * via memory hot-add.
4907 * But it may be the case that a new node was hot-added. In
4908 * this case vmalloc() will not be able to use this new node's
4909 * memory - this wait_table must be initialized to use this new
4910 * node itself as well.
4911 * To use this new node's memory, further consideration will be
4914 zone->wait_table = vmalloc(alloc_size);
4916 if (!zone->wait_table)
4919 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4920 init_waitqueue_head(zone->wait_table + i);
4925 static __meminit void zone_pcp_init(struct zone *zone)
4928 * per cpu subsystem is not up at this point. The following code
4929 * relies on the ability of the linker to provide the
4930 * offset of a (static) per cpu variable into the per cpu area.
4932 zone->pageset = &boot_pageset;
4934 if (populated_zone(zone))
4935 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4936 zone->name, zone->present_pages,
4937 zone_batchsize(zone));
4940 int __meminit init_currently_empty_zone(struct zone *zone,
4941 unsigned long zone_start_pfn,
4944 struct pglist_data *pgdat = zone->zone_pgdat;
4946 ret = zone_wait_table_init(zone, size);
4949 pgdat->nr_zones = zone_idx(zone) + 1;
4951 zone->zone_start_pfn = zone_start_pfn;
4953 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4954 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4956 (unsigned long)zone_idx(zone),
4957 zone_start_pfn, (zone_start_pfn + size));
4959 zone_init_free_lists(zone);
4964 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4965 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4968 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4970 int __meminit __early_pfn_to_nid(unsigned long pfn,
4971 struct mminit_pfnnid_cache *state)
4973 unsigned long start_pfn, end_pfn;
4976 if (state->last_start <= pfn && pfn < state->last_end)
4977 return state->last_nid;
4979 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4981 state->last_start = start_pfn;
4982 state->last_end = end_pfn;
4983 state->last_nid = nid;
4988 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4991 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4992 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4993 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4995 * If an architecture guarantees that all ranges registered contain no holes
4996 * and may be freed, this this function may be used instead of calling
4997 * memblock_free_early_nid() manually.
4999 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5001 unsigned long start_pfn, end_pfn;
5004 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5005 start_pfn = min(start_pfn, max_low_pfn);
5006 end_pfn = min(end_pfn, max_low_pfn);
5008 if (start_pfn < end_pfn)
5009 memblock_free_early_nid(PFN_PHYS(start_pfn),
5010 (end_pfn - start_pfn) << PAGE_SHIFT,
5016 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5017 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5019 * If an architecture guarantees that all ranges registered contain no holes and may
5020 * be freed, this function may be used instead of calling memory_present() manually.
5022 void __init sparse_memory_present_with_active_regions(int nid)
5024 unsigned long start_pfn, end_pfn;
5027 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5028 memory_present(this_nid, start_pfn, end_pfn);
5032 * get_pfn_range_for_nid - Return the start and end page frames for a node
5033 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5034 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5035 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5037 * It returns the start and end page frame of a node based on information
5038 * provided by memblock_set_node(). If called for a node
5039 * with no available memory, a warning is printed and the start and end
5042 void __meminit get_pfn_range_for_nid(unsigned int nid,
5043 unsigned long *start_pfn, unsigned long *end_pfn)
5045 unsigned long this_start_pfn, this_end_pfn;
5051 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5052 *start_pfn = min(*start_pfn, this_start_pfn);
5053 *end_pfn = max(*end_pfn, this_end_pfn);
5056 if (*start_pfn == -1UL)
5061 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5062 * assumption is made that zones within a node are ordered in monotonic
5063 * increasing memory addresses so that the "highest" populated zone is used
5065 static void __init find_usable_zone_for_movable(void)
5068 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5069 if (zone_index == ZONE_MOVABLE)
5072 if (arch_zone_highest_possible_pfn[zone_index] >
5073 arch_zone_lowest_possible_pfn[zone_index])
5077 VM_BUG_ON(zone_index == -1);
5078 movable_zone = zone_index;
5082 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5083 * because it is sized independent of architecture. Unlike the other zones,
5084 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5085 * in each node depending on the size of each node and how evenly kernelcore
5086 * is distributed. This helper function adjusts the zone ranges
5087 * provided by the architecture for a given node by using the end of the
5088 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5089 * zones within a node are in order of monotonic increases memory addresses
5091 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5092 unsigned long zone_type,
5093 unsigned long node_start_pfn,
5094 unsigned long node_end_pfn,
5095 unsigned long *zone_start_pfn,
5096 unsigned long *zone_end_pfn)
5098 /* Only adjust if ZONE_MOVABLE is on this node */
5099 if (zone_movable_pfn[nid]) {
5100 /* Size ZONE_MOVABLE */
5101 if (zone_type == ZONE_MOVABLE) {
5102 *zone_start_pfn = zone_movable_pfn[nid];
5103 *zone_end_pfn = min(node_end_pfn,
5104 arch_zone_highest_possible_pfn[movable_zone]);
5106 /* Check if this whole range is within ZONE_MOVABLE */
5107 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5108 *zone_start_pfn = *zone_end_pfn;
5113 * Return the number of pages a zone spans in a node, including holes
5114 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5116 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5117 unsigned long zone_type,
5118 unsigned long node_start_pfn,
5119 unsigned long node_end_pfn,
5120 unsigned long *zone_start_pfn,
5121 unsigned long *zone_end_pfn,
5122 unsigned long *ignored)
5124 /* When hotadd a new node from cpu_up(), the node should be empty */
5125 if (!node_start_pfn && !node_end_pfn)
5128 /* Get the start and end of the zone */
5129 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5130 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5131 adjust_zone_range_for_zone_movable(nid, zone_type,
5132 node_start_pfn, node_end_pfn,
5133 zone_start_pfn, zone_end_pfn);
5135 /* Check that this node has pages within the zone's required range */
5136 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5139 /* Move the zone boundaries inside the node if necessary */
5140 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5141 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5143 /* Return the spanned pages */
5144 return *zone_end_pfn - *zone_start_pfn;
5148 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5149 * then all holes in the requested range will be accounted for.
5151 unsigned long __meminit __absent_pages_in_range(int nid,
5152 unsigned long range_start_pfn,
5153 unsigned long range_end_pfn)
5155 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5156 unsigned long start_pfn, end_pfn;
5159 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5160 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5161 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5162 nr_absent -= end_pfn - start_pfn;
5168 * absent_pages_in_range - Return number of page frames in holes within a range
5169 * @start_pfn: The start PFN to start searching for holes
5170 * @end_pfn: The end PFN to stop searching for holes
5172 * It returns the number of pages frames in memory holes within a range.
5174 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5175 unsigned long end_pfn)
5177 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5180 /* Return the number of page frames in holes in a zone on a node */
5181 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5182 unsigned long zone_type,
5183 unsigned long node_start_pfn,
5184 unsigned long node_end_pfn,
5185 unsigned long *ignored)
5187 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5188 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5189 unsigned long zone_start_pfn, zone_end_pfn;
5190 unsigned long nr_absent;
5192 /* When hotadd a new node from cpu_up(), the node should be empty */
5193 if (!node_start_pfn && !node_end_pfn)
5196 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5197 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5199 adjust_zone_range_for_zone_movable(nid, zone_type,
5200 node_start_pfn, node_end_pfn,
5201 &zone_start_pfn, &zone_end_pfn);
5202 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5205 * ZONE_MOVABLE handling.
5206 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5209 if (zone_movable_pfn[nid]) {
5210 if (mirrored_kernelcore) {
5211 unsigned long start_pfn, end_pfn;
5212 struct memblock_region *r;
5214 for_each_memblock(memory, r) {
5215 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5216 zone_start_pfn, zone_end_pfn);
5217 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5218 zone_start_pfn, zone_end_pfn);
5220 if (zone_type == ZONE_MOVABLE &&
5221 memblock_is_mirror(r))
5222 nr_absent += end_pfn - start_pfn;
5224 if (zone_type == ZONE_NORMAL &&
5225 !memblock_is_mirror(r))
5226 nr_absent += end_pfn - start_pfn;
5229 if (zone_type == ZONE_NORMAL)
5230 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5237 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5238 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5239 unsigned long zone_type,
5240 unsigned long node_start_pfn,
5241 unsigned long node_end_pfn,
5242 unsigned long *zone_start_pfn,
5243 unsigned long *zone_end_pfn,
5244 unsigned long *zones_size)
5248 *zone_start_pfn = node_start_pfn;
5249 for (zone = 0; zone < zone_type; zone++)
5250 *zone_start_pfn += zones_size[zone];
5252 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5254 return zones_size[zone_type];
5257 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5258 unsigned long zone_type,
5259 unsigned long node_start_pfn,
5260 unsigned long node_end_pfn,
5261 unsigned long *zholes_size)
5266 return zholes_size[zone_type];
5269 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5271 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5272 unsigned long node_start_pfn,
5273 unsigned long node_end_pfn,
5274 unsigned long *zones_size,
5275 unsigned long *zholes_size)
5277 unsigned long realtotalpages = 0, totalpages = 0;
5280 for (i = 0; i < MAX_NR_ZONES; i++) {
5281 struct zone *zone = pgdat->node_zones + i;
5282 unsigned long zone_start_pfn, zone_end_pfn;
5283 unsigned long size, real_size;
5285 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5291 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5292 node_start_pfn, node_end_pfn,
5295 zone->zone_start_pfn = zone_start_pfn;
5297 zone->zone_start_pfn = 0;
5298 zone->spanned_pages = size;
5299 zone->present_pages = real_size;
5302 realtotalpages += real_size;
5305 pgdat->node_spanned_pages = totalpages;
5306 pgdat->node_present_pages = realtotalpages;
5307 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5311 #ifndef CONFIG_SPARSEMEM
5313 * Calculate the size of the zone->blockflags rounded to an unsigned long
5314 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5315 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5316 * round what is now in bits to nearest long in bits, then return it in
5319 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5321 unsigned long usemapsize;
5323 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5324 usemapsize = roundup(zonesize, pageblock_nr_pages);
5325 usemapsize = usemapsize >> pageblock_order;
5326 usemapsize *= NR_PAGEBLOCK_BITS;
5327 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5329 return usemapsize / 8;
5332 static void __init setup_usemap(struct pglist_data *pgdat,
5334 unsigned long zone_start_pfn,
5335 unsigned long zonesize)
5337 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5338 zone->pageblock_flags = NULL;
5340 zone->pageblock_flags =
5341 memblock_virt_alloc_node_nopanic(usemapsize,
5345 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5346 unsigned long zone_start_pfn, unsigned long zonesize) {}
5347 #endif /* CONFIG_SPARSEMEM */
5349 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5351 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5352 void __paginginit set_pageblock_order(void)
5356 /* Check that pageblock_nr_pages has not already been setup */
5357 if (pageblock_order)
5360 if (HPAGE_SHIFT > PAGE_SHIFT)
5361 order = HUGETLB_PAGE_ORDER;
5363 order = MAX_ORDER - 1;
5366 * Assume the largest contiguous order of interest is a huge page.
5367 * This value may be variable depending on boot parameters on IA64 and
5370 pageblock_order = order;
5372 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5375 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5376 * is unused as pageblock_order is set at compile-time. See
5377 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5380 void __paginginit set_pageblock_order(void)
5384 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5386 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5387 unsigned long present_pages)
5389 unsigned long pages = spanned_pages;
5392 * Provide a more accurate estimation if there are holes within
5393 * the zone and SPARSEMEM is in use. If there are holes within the
5394 * zone, each populated memory region may cost us one or two extra
5395 * memmap pages due to alignment because memmap pages for each
5396 * populated regions may not naturally algined on page boundary.
5397 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5399 if (spanned_pages > present_pages + (present_pages >> 4) &&
5400 IS_ENABLED(CONFIG_SPARSEMEM))
5401 pages = present_pages;
5403 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5407 * Set up the zone data structures:
5408 * - mark all pages reserved
5409 * - mark all memory queues empty
5410 * - clear the memory bitmaps
5412 * NOTE: pgdat should get zeroed by caller.
5414 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5417 int nid = pgdat->node_id;
5420 pgdat_resize_init(pgdat);
5421 #ifdef CONFIG_NUMA_BALANCING
5422 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5423 pgdat->numabalancing_migrate_nr_pages = 0;
5424 pgdat->numabalancing_migrate_next_window = jiffies;
5426 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5427 spin_lock_init(&pgdat->split_queue_lock);
5428 INIT_LIST_HEAD(&pgdat->split_queue);
5429 pgdat->split_queue_len = 0;
5431 init_waitqueue_head(&pgdat->kswapd_wait);
5432 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5433 #ifdef CONFIG_COMPACTION
5434 init_waitqueue_head(&pgdat->kcompactd_wait);
5436 pgdat_page_ext_init(pgdat);
5438 for (j = 0; j < MAX_NR_ZONES; j++) {
5439 struct zone *zone = pgdat->node_zones + j;
5440 unsigned long size, realsize, freesize, memmap_pages;
5441 unsigned long zone_start_pfn = zone->zone_start_pfn;
5443 size = zone->spanned_pages;
5444 realsize = freesize = zone->present_pages;
5447 * Adjust freesize so that it accounts for how much memory
5448 * is used by this zone for memmap. This affects the watermark
5449 * and per-cpu initialisations
5451 memmap_pages = calc_memmap_size(size, realsize);
5452 if (!is_highmem_idx(j)) {
5453 if (freesize >= memmap_pages) {
5454 freesize -= memmap_pages;
5457 " %s zone: %lu pages used for memmap\n",
5458 zone_names[j], memmap_pages);
5460 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5461 zone_names[j], memmap_pages, freesize);
5464 /* Account for reserved pages */
5465 if (j == 0 && freesize > dma_reserve) {
5466 freesize -= dma_reserve;
5467 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5468 zone_names[0], dma_reserve);
5471 if (!is_highmem_idx(j))
5472 nr_kernel_pages += freesize;
5473 /* Charge for highmem memmap if there are enough kernel pages */
5474 else if (nr_kernel_pages > memmap_pages * 2)
5475 nr_kernel_pages -= memmap_pages;
5476 nr_all_pages += freesize;
5479 * Set an approximate value for lowmem here, it will be adjusted
5480 * when the bootmem allocator frees pages into the buddy system.
5481 * And all highmem pages will be managed by the buddy system.
5483 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5486 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5488 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5490 zone->name = zone_names[j];
5491 spin_lock_init(&zone->lock);
5492 spin_lock_init(&zone->lru_lock);
5493 zone_seqlock_init(zone);
5494 zone->zone_pgdat = pgdat;
5495 zone_pcp_init(zone);
5497 /* For bootup, initialized properly in watermark setup */
5498 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5500 lruvec_init(&zone->lruvec);
5504 set_pageblock_order();
5505 setup_usemap(pgdat, zone, zone_start_pfn, size);
5506 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5508 memmap_init(size, nid, j, zone_start_pfn);
5512 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5514 unsigned long __maybe_unused start = 0;
5515 unsigned long __maybe_unused offset = 0;
5517 /* Skip empty nodes */
5518 if (!pgdat->node_spanned_pages)
5521 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5522 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5523 offset = pgdat->node_start_pfn - start;
5524 /* ia64 gets its own node_mem_map, before this, without bootmem */
5525 if (!pgdat->node_mem_map) {
5526 unsigned long size, end;
5530 * The zone's endpoints aren't required to be MAX_ORDER
5531 * aligned but the node_mem_map endpoints must be in order
5532 * for the buddy allocator to function correctly.
5534 end = pgdat_end_pfn(pgdat);
5535 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5536 size = (end - start) * sizeof(struct page);
5537 map = alloc_remap(pgdat->node_id, size);
5539 map = memblock_virt_alloc_node_nopanic(size,
5541 pgdat->node_mem_map = map + offset;
5543 #ifndef CONFIG_NEED_MULTIPLE_NODES
5545 * With no DISCONTIG, the global mem_map is just set as node 0's
5547 if (pgdat == NODE_DATA(0)) {
5548 mem_map = NODE_DATA(0)->node_mem_map;
5549 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5550 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5552 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5555 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5558 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5559 unsigned long node_start_pfn, unsigned long *zholes_size)
5561 pg_data_t *pgdat = NODE_DATA(nid);
5562 unsigned long start_pfn = 0;
5563 unsigned long end_pfn = 0;
5565 /* pg_data_t should be reset to zero when it's allocated */
5566 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5568 reset_deferred_meminit(pgdat);
5569 pgdat->node_id = nid;
5570 pgdat->node_start_pfn = node_start_pfn;
5571 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5572 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5573 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5574 (u64)start_pfn << PAGE_SHIFT,
5575 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5577 start_pfn = node_start_pfn;
5579 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5580 zones_size, zholes_size);
5582 alloc_node_mem_map(pgdat);
5583 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5584 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5585 nid, (unsigned long)pgdat,
5586 (unsigned long)pgdat->node_mem_map);
5589 free_area_init_core(pgdat);
5592 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5594 #if MAX_NUMNODES > 1
5596 * Figure out the number of possible node ids.
5598 void __init setup_nr_node_ids(void)
5600 unsigned int highest;
5602 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5603 nr_node_ids = highest + 1;
5608 * node_map_pfn_alignment - determine the maximum internode alignment
5610 * This function should be called after node map is populated and sorted.
5611 * It calculates the maximum power of two alignment which can distinguish
5614 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5615 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5616 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5617 * shifted, 1GiB is enough and this function will indicate so.
5619 * This is used to test whether pfn -> nid mapping of the chosen memory
5620 * model has fine enough granularity to avoid incorrect mapping for the
5621 * populated node map.
5623 * Returns the determined alignment in pfn's. 0 if there is no alignment
5624 * requirement (single node).
5626 unsigned long __init node_map_pfn_alignment(void)
5628 unsigned long accl_mask = 0, last_end = 0;
5629 unsigned long start, end, mask;
5633 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5634 if (!start || last_nid < 0 || last_nid == nid) {
5641 * Start with a mask granular enough to pin-point to the
5642 * start pfn and tick off bits one-by-one until it becomes
5643 * too coarse to separate the current node from the last.
5645 mask = ~((1 << __ffs(start)) - 1);
5646 while (mask && last_end <= (start & (mask << 1)))
5649 /* accumulate all internode masks */
5653 /* convert mask to number of pages */
5654 return ~accl_mask + 1;
5657 /* Find the lowest pfn for a node */
5658 static unsigned long __init find_min_pfn_for_node(int nid)
5660 unsigned long min_pfn = ULONG_MAX;
5661 unsigned long start_pfn;
5664 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5665 min_pfn = min(min_pfn, start_pfn);
5667 if (min_pfn == ULONG_MAX) {
5668 pr_warn("Could not find start_pfn for node %d\n", nid);
5676 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5678 * It returns the minimum PFN based on information provided via
5679 * memblock_set_node().
5681 unsigned long __init find_min_pfn_with_active_regions(void)
5683 return find_min_pfn_for_node(MAX_NUMNODES);
5687 * early_calculate_totalpages()
5688 * Sum pages in active regions for movable zone.
5689 * Populate N_MEMORY for calculating usable_nodes.
5691 static unsigned long __init early_calculate_totalpages(void)
5693 unsigned long totalpages = 0;
5694 unsigned long start_pfn, end_pfn;
5697 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5698 unsigned long pages = end_pfn - start_pfn;
5700 totalpages += pages;
5702 node_set_state(nid, N_MEMORY);
5708 * Find the PFN the Movable zone begins in each node. Kernel memory
5709 * is spread evenly between nodes as long as the nodes have enough
5710 * memory. When they don't, some nodes will have more kernelcore than
5713 static void __init find_zone_movable_pfns_for_nodes(void)
5716 unsigned long usable_startpfn;
5717 unsigned long kernelcore_node, kernelcore_remaining;
5718 /* save the state before borrow the nodemask */
5719 nodemask_t saved_node_state = node_states[N_MEMORY];
5720 unsigned long totalpages = early_calculate_totalpages();
5721 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5722 struct memblock_region *r;
5724 /* Need to find movable_zone earlier when movable_node is specified. */
5725 find_usable_zone_for_movable();
5728 * If movable_node is specified, ignore kernelcore and movablecore
5731 if (movable_node_is_enabled()) {
5732 for_each_memblock(memory, r) {
5733 if (!memblock_is_hotpluggable(r))
5738 usable_startpfn = PFN_DOWN(r->base);
5739 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5740 min(usable_startpfn, zone_movable_pfn[nid]) :
5748 * If kernelcore=mirror is specified, ignore movablecore option
5750 if (mirrored_kernelcore) {
5751 bool mem_below_4gb_not_mirrored = false;
5753 for_each_memblock(memory, r) {
5754 if (memblock_is_mirror(r))
5759 usable_startpfn = memblock_region_memory_base_pfn(r);
5761 if (usable_startpfn < 0x100000) {
5762 mem_below_4gb_not_mirrored = true;
5766 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5767 min(usable_startpfn, zone_movable_pfn[nid]) :
5771 if (mem_below_4gb_not_mirrored)
5772 pr_warn("This configuration results in unmirrored kernel memory.");
5778 * If movablecore=nn[KMG] was specified, calculate what size of
5779 * kernelcore that corresponds so that memory usable for
5780 * any allocation type is evenly spread. If both kernelcore
5781 * and movablecore are specified, then the value of kernelcore
5782 * will be used for required_kernelcore if it's greater than
5783 * what movablecore would have allowed.
5785 if (required_movablecore) {
5786 unsigned long corepages;
5789 * Round-up so that ZONE_MOVABLE is at least as large as what
5790 * was requested by the user
5792 required_movablecore =
5793 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5794 required_movablecore = min(totalpages, required_movablecore);
5795 corepages = totalpages - required_movablecore;
5797 required_kernelcore = max(required_kernelcore, corepages);
5801 * If kernelcore was not specified or kernelcore size is larger
5802 * than totalpages, there is no ZONE_MOVABLE.
5804 if (!required_kernelcore || required_kernelcore >= totalpages)
5807 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5808 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5811 /* Spread kernelcore memory as evenly as possible throughout nodes */
5812 kernelcore_node = required_kernelcore / usable_nodes;
5813 for_each_node_state(nid, N_MEMORY) {
5814 unsigned long start_pfn, end_pfn;
5817 * Recalculate kernelcore_node if the division per node
5818 * now exceeds what is necessary to satisfy the requested
5819 * amount of memory for the kernel
5821 if (required_kernelcore < kernelcore_node)
5822 kernelcore_node = required_kernelcore / usable_nodes;
5825 * As the map is walked, we track how much memory is usable
5826 * by the kernel using kernelcore_remaining. When it is
5827 * 0, the rest of the node is usable by ZONE_MOVABLE
5829 kernelcore_remaining = kernelcore_node;
5831 /* Go through each range of PFNs within this node */
5832 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5833 unsigned long size_pages;
5835 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5836 if (start_pfn >= end_pfn)
5839 /* Account for what is only usable for kernelcore */
5840 if (start_pfn < usable_startpfn) {
5841 unsigned long kernel_pages;
5842 kernel_pages = min(end_pfn, usable_startpfn)
5845 kernelcore_remaining -= min(kernel_pages,
5846 kernelcore_remaining);
5847 required_kernelcore -= min(kernel_pages,
5848 required_kernelcore);
5850 /* Continue if range is now fully accounted */
5851 if (end_pfn <= usable_startpfn) {
5854 * Push zone_movable_pfn to the end so
5855 * that if we have to rebalance
5856 * kernelcore across nodes, we will
5857 * not double account here
5859 zone_movable_pfn[nid] = end_pfn;
5862 start_pfn = usable_startpfn;
5866 * The usable PFN range for ZONE_MOVABLE is from
5867 * start_pfn->end_pfn. Calculate size_pages as the
5868 * number of pages used as kernelcore
5870 size_pages = end_pfn - start_pfn;
5871 if (size_pages > kernelcore_remaining)
5872 size_pages = kernelcore_remaining;
5873 zone_movable_pfn[nid] = start_pfn + size_pages;
5876 * Some kernelcore has been met, update counts and
5877 * break if the kernelcore for this node has been
5880 required_kernelcore -= min(required_kernelcore,
5882 kernelcore_remaining -= size_pages;
5883 if (!kernelcore_remaining)
5889 * If there is still required_kernelcore, we do another pass with one
5890 * less node in the count. This will push zone_movable_pfn[nid] further
5891 * along on the nodes that still have memory until kernelcore is
5895 if (usable_nodes && required_kernelcore > usable_nodes)
5899 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5900 for (nid = 0; nid < MAX_NUMNODES; nid++)
5901 zone_movable_pfn[nid] =
5902 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5905 /* restore the node_state */
5906 node_states[N_MEMORY] = saved_node_state;
5909 /* Any regular or high memory on that node ? */
5910 static void check_for_memory(pg_data_t *pgdat, int nid)
5912 enum zone_type zone_type;
5914 if (N_MEMORY == N_NORMAL_MEMORY)
5917 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5918 struct zone *zone = &pgdat->node_zones[zone_type];
5919 if (populated_zone(zone)) {
5920 node_set_state(nid, N_HIGH_MEMORY);
5921 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5922 zone_type <= ZONE_NORMAL)
5923 node_set_state(nid, N_NORMAL_MEMORY);
5930 * free_area_init_nodes - Initialise all pg_data_t and zone data
5931 * @max_zone_pfn: an array of max PFNs for each zone
5933 * This will call free_area_init_node() for each active node in the system.
5934 * Using the page ranges provided by memblock_set_node(), the size of each
5935 * zone in each node and their holes is calculated. If the maximum PFN
5936 * between two adjacent zones match, it is assumed that the zone is empty.
5937 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5938 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5939 * starts where the previous one ended. For example, ZONE_DMA32 starts
5940 * at arch_max_dma_pfn.
5942 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5944 unsigned long start_pfn, end_pfn;
5947 /* Record where the zone boundaries are */
5948 memset(arch_zone_lowest_possible_pfn, 0,
5949 sizeof(arch_zone_lowest_possible_pfn));
5950 memset(arch_zone_highest_possible_pfn, 0,
5951 sizeof(arch_zone_highest_possible_pfn));
5952 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5953 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5954 for (i = 1; i < MAX_NR_ZONES; i++) {
5955 if (i == ZONE_MOVABLE)
5957 arch_zone_lowest_possible_pfn[i] =
5958 arch_zone_highest_possible_pfn[i-1];
5959 arch_zone_highest_possible_pfn[i] =
5960 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5962 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5963 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5965 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5966 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5967 find_zone_movable_pfns_for_nodes();
5969 /* Print out the zone ranges */
5970 pr_info("Zone ranges:\n");
5971 for (i = 0; i < MAX_NR_ZONES; i++) {
5972 if (i == ZONE_MOVABLE)
5974 pr_info(" %-8s ", zone_names[i]);
5975 if (arch_zone_lowest_possible_pfn[i] ==
5976 arch_zone_highest_possible_pfn[i])
5979 pr_cont("[mem %#018Lx-%#018Lx]\n",
5980 (u64)arch_zone_lowest_possible_pfn[i]
5982 ((u64)arch_zone_highest_possible_pfn[i]
5983 << PAGE_SHIFT) - 1);
5986 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5987 pr_info("Movable zone start for each node\n");
5988 for (i = 0; i < MAX_NUMNODES; i++) {
5989 if (zone_movable_pfn[i])
5990 pr_info(" Node %d: %#018Lx\n", i,
5991 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
5994 /* Print out the early node map */
5995 pr_info("Early memory node ranges\n");
5996 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5997 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
5998 (u64)start_pfn << PAGE_SHIFT,
5999 ((u64)end_pfn << PAGE_SHIFT) - 1);
6001 /* Initialise every node */
6002 mminit_verify_pageflags_layout();
6003 setup_nr_node_ids();
6004 for_each_online_node(nid) {
6005 pg_data_t *pgdat = NODE_DATA(nid);
6006 free_area_init_node(nid, NULL,
6007 find_min_pfn_for_node(nid), NULL);
6009 /* Any memory on that node */
6010 if (pgdat->node_present_pages)
6011 node_set_state(nid, N_MEMORY);
6012 check_for_memory(pgdat, nid);
6016 static int __init cmdline_parse_core(char *p, unsigned long *core)
6018 unsigned long long coremem;
6022 coremem = memparse(p, &p);
6023 *core = coremem >> PAGE_SHIFT;
6025 /* Paranoid check that UL is enough for the coremem value */
6026 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6032 * kernelcore=size sets the amount of memory for use for allocations that
6033 * cannot be reclaimed or migrated.
6035 static int __init cmdline_parse_kernelcore(char *p)
6037 /* parse kernelcore=mirror */
6038 if (parse_option_str(p, "mirror")) {
6039 mirrored_kernelcore = true;
6043 return cmdline_parse_core(p, &required_kernelcore);
6047 * movablecore=size sets the amount of memory for use for allocations that
6048 * can be reclaimed or migrated.
6050 static int __init cmdline_parse_movablecore(char *p)
6052 return cmdline_parse_core(p, &required_movablecore);
6055 early_param("kernelcore", cmdline_parse_kernelcore);
6056 early_param("movablecore", cmdline_parse_movablecore);
6058 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6060 void adjust_managed_page_count(struct page *page, long count)
6062 spin_lock(&managed_page_count_lock);
6063 page_zone(page)->managed_pages += count;
6064 totalram_pages += count;
6065 #ifdef CONFIG_HIGHMEM
6066 if (PageHighMem(page))
6067 totalhigh_pages += count;
6069 spin_unlock(&managed_page_count_lock);
6071 EXPORT_SYMBOL(adjust_managed_page_count);
6073 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6076 unsigned long pages = 0;
6078 start = (void *)PAGE_ALIGN((unsigned long)start);
6079 end = (void *)((unsigned long)end & PAGE_MASK);
6080 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6081 if ((unsigned int)poison <= 0xFF)
6082 memset(pos, poison, PAGE_SIZE);
6083 free_reserved_page(virt_to_page(pos));
6087 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6088 s, pages << (PAGE_SHIFT - 10), start, end);
6092 EXPORT_SYMBOL(free_reserved_area);
6094 #ifdef CONFIG_HIGHMEM
6095 void free_highmem_page(struct page *page)
6097 __free_reserved_page(page);
6099 page_zone(page)->managed_pages++;
6105 void __init mem_init_print_info(const char *str)
6107 unsigned long physpages, codesize, datasize, rosize, bss_size;
6108 unsigned long init_code_size, init_data_size;
6110 physpages = get_num_physpages();
6111 codesize = _etext - _stext;
6112 datasize = _edata - _sdata;
6113 rosize = __end_rodata - __start_rodata;
6114 bss_size = __bss_stop - __bss_start;
6115 init_data_size = __init_end - __init_begin;
6116 init_code_size = _einittext - _sinittext;
6119 * Detect special cases and adjust section sizes accordingly:
6120 * 1) .init.* may be embedded into .data sections
6121 * 2) .init.text.* may be out of [__init_begin, __init_end],
6122 * please refer to arch/tile/kernel/vmlinux.lds.S.
6123 * 3) .rodata.* may be embedded into .text or .data sections.
6125 #define adj_init_size(start, end, size, pos, adj) \
6127 if (start <= pos && pos < end && size > adj) \
6131 adj_init_size(__init_begin, __init_end, init_data_size,
6132 _sinittext, init_code_size);
6133 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6134 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6135 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6136 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6138 #undef adj_init_size
6140 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6141 #ifdef CONFIG_HIGHMEM
6145 nr_free_pages() << (PAGE_SHIFT - 10),
6146 physpages << (PAGE_SHIFT - 10),
6147 codesize >> 10, datasize >> 10, rosize >> 10,
6148 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6149 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6150 totalcma_pages << (PAGE_SHIFT - 10),
6151 #ifdef CONFIG_HIGHMEM
6152 totalhigh_pages << (PAGE_SHIFT - 10),
6154 str ? ", " : "", str ? str : "");
6158 * set_dma_reserve - set the specified number of pages reserved in the first zone
6159 * @new_dma_reserve: The number of pages to mark reserved
6161 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6162 * In the DMA zone, a significant percentage may be consumed by kernel image
6163 * and other unfreeable allocations which can skew the watermarks badly. This
6164 * function may optionally be used to account for unfreeable pages in the
6165 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6166 * smaller per-cpu batchsize.
6168 void __init set_dma_reserve(unsigned long new_dma_reserve)
6170 dma_reserve = new_dma_reserve;
6173 void __init free_area_init(unsigned long *zones_size)
6175 free_area_init_node(0, zones_size,
6176 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6179 static int page_alloc_cpu_notify(struct notifier_block *self,
6180 unsigned long action, void *hcpu)
6182 int cpu = (unsigned long)hcpu;
6184 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6185 lru_add_drain_cpu(cpu);
6189 * Spill the event counters of the dead processor
6190 * into the current processors event counters.
6191 * This artificially elevates the count of the current
6194 vm_events_fold_cpu(cpu);
6197 * Zero the differential counters of the dead processor
6198 * so that the vm statistics are consistent.
6200 * This is only okay since the processor is dead and cannot
6201 * race with what we are doing.
6203 cpu_vm_stats_fold(cpu);
6208 void __init page_alloc_init(void)
6210 hotcpu_notifier(page_alloc_cpu_notify, 0);
6214 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6215 * or min_free_kbytes changes.
6217 static void calculate_totalreserve_pages(void)
6219 struct pglist_data *pgdat;
6220 unsigned long reserve_pages = 0;
6221 enum zone_type i, j;
6223 for_each_online_pgdat(pgdat) {
6224 for (i = 0; i < MAX_NR_ZONES; i++) {
6225 struct zone *zone = pgdat->node_zones + i;
6228 /* Find valid and maximum lowmem_reserve in the zone */
6229 for (j = i; j < MAX_NR_ZONES; j++) {
6230 if (zone->lowmem_reserve[j] > max)
6231 max = zone->lowmem_reserve[j];
6234 /* we treat the high watermark as reserved pages. */
6235 max += high_wmark_pages(zone);
6237 if (max > zone->managed_pages)
6238 max = zone->managed_pages;
6240 zone->totalreserve_pages = max;
6242 reserve_pages += max;
6245 totalreserve_pages = reserve_pages;
6249 * setup_per_zone_lowmem_reserve - called whenever
6250 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6251 * has a correct pages reserved value, so an adequate number of
6252 * pages are left in the zone after a successful __alloc_pages().
6254 static void setup_per_zone_lowmem_reserve(void)
6256 struct pglist_data *pgdat;
6257 enum zone_type j, idx;
6259 for_each_online_pgdat(pgdat) {
6260 for (j = 0; j < MAX_NR_ZONES; j++) {
6261 struct zone *zone = pgdat->node_zones + j;
6262 unsigned long managed_pages = zone->managed_pages;
6264 zone->lowmem_reserve[j] = 0;
6268 struct zone *lower_zone;
6272 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6273 sysctl_lowmem_reserve_ratio[idx] = 1;
6275 lower_zone = pgdat->node_zones + idx;
6276 lower_zone->lowmem_reserve[j] = managed_pages /
6277 sysctl_lowmem_reserve_ratio[idx];
6278 managed_pages += lower_zone->managed_pages;
6283 /* update totalreserve_pages */
6284 calculate_totalreserve_pages();
6287 static void __setup_per_zone_wmarks(void)
6289 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6290 unsigned long lowmem_pages = 0;
6292 unsigned long flags;
6294 /* Calculate total number of !ZONE_HIGHMEM pages */
6295 for_each_zone(zone) {
6296 if (!is_highmem(zone))
6297 lowmem_pages += zone->managed_pages;
6300 for_each_zone(zone) {
6303 spin_lock_irqsave(&zone->lock, flags);
6304 tmp = (u64)pages_min * zone->managed_pages;
6305 do_div(tmp, lowmem_pages);
6306 if (is_highmem(zone)) {
6308 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6309 * need highmem pages, so cap pages_min to a small
6312 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6313 * deltas control asynch page reclaim, and so should
6314 * not be capped for highmem.
6316 unsigned long min_pages;
6318 min_pages = zone->managed_pages / 1024;
6319 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6320 zone->watermark[WMARK_MIN] = min_pages;
6323 * If it's a lowmem zone, reserve a number of pages
6324 * proportionate to the zone's size.
6326 zone->watermark[WMARK_MIN] = tmp;
6330 * Set the kswapd watermarks distance according to the
6331 * scale factor in proportion to available memory, but
6332 * ensure a minimum size on small systems.
6334 tmp = max_t(u64, tmp >> 2,
6335 mult_frac(zone->managed_pages,
6336 watermark_scale_factor, 10000));
6338 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6339 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6341 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6342 high_wmark_pages(zone) - low_wmark_pages(zone) -
6343 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6345 spin_unlock_irqrestore(&zone->lock, flags);
6348 /* update totalreserve_pages */
6349 calculate_totalreserve_pages();
6353 * setup_per_zone_wmarks - called when min_free_kbytes changes
6354 * or when memory is hot-{added|removed}
6356 * Ensures that the watermark[min,low,high] values for each zone are set
6357 * correctly with respect to min_free_kbytes.
6359 void setup_per_zone_wmarks(void)
6361 mutex_lock(&zonelists_mutex);
6362 __setup_per_zone_wmarks();
6363 mutex_unlock(&zonelists_mutex);
6367 * The inactive anon list should be small enough that the VM never has to
6368 * do too much work, but large enough that each inactive page has a chance
6369 * to be referenced again before it is swapped out.
6371 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6372 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6373 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6374 * the anonymous pages are kept on the inactive list.
6377 * memory ratio inactive anon
6378 * -------------------------------------
6387 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6389 unsigned int gb, ratio;
6391 /* Zone size in gigabytes */
6392 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6394 ratio = int_sqrt(10 * gb);
6398 zone->inactive_ratio = ratio;
6401 static void __meminit setup_per_zone_inactive_ratio(void)
6406 calculate_zone_inactive_ratio(zone);
6410 * Initialise min_free_kbytes.
6412 * For small machines we want it small (128k min). For large machines
6413 * we want it large (64MB max). But it is not linear, because network
6414 * bandwidth does not increase linearly with machine size. We use
6416 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6417 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6433 int __meminit init_per_zone_wmark_min(void)
6435 unsigned long lowmem_kbytes;
6436 int new_min_free_kbytes;
6438 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6439 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6441 if (new_min_free_kbytes > user_min_free_kbytes) {
6442 min_free_kbytes = new_min_free_kbytes;
6443 if (min_free_kbytes < 128)
6444 min_free_kbytes = 128;
6445 if (min_free_kbytes > 65536)
6446 min_free_kbytes = 65536;
6448 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6449 new_min_free_kbytes, user_min_free_kbytes);
6451 setup_per_zone_wmarks();
6452 refresh_zone_stat_thresholds();
6453 setup_per_zone_lowmem_reserve();
6454 setup_per_zone_inactive_ratio();
6457 module_init(init_per_zone_wmark_min)
6460 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6461 * that we can call two helper functions whenever min_free_kbytes
6464 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6465 void __user *buffer, size_t *length, loff_t *ppos)
6469 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6474 user_min_free_kbytes = min_free_kbytes;
6475 setup_per_zone_wmarks();
6480 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6481 void __user *buffer, size_t *length, loff_t *ppos)
6485 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6490 setup_per_zone_wmarks();
6496 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6497 void __user *buffer, size_t *length, loff_t *ppos)
6502 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6507 zone->min_unmapped_pages = (zone->managed_pages *
6508 sysctl_min_unmapped_ratio) / 100;
6512 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6513 void __user *buffer, size_t *length, loff_t *ppos)
6518 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6523 zone->min_slab_pages = (zone->managed_pages *
6524 sysctl_min_slab_ratio) / 100;
6530 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6531 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6532 * whenever sysctl_lowmem_reserve_ratio changes.
6534 * The reserve ratio obviously has absolutely no relation with the
6535 * minimum watermarks. The lowmem reserve ratio can only make sense
6536 * if in function of the boot time zone sizes.
6538 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6539 void __user *buffer, size_t *length, loff_t *ppos)
6541 proc_dointvec_minmax(table, write, buffer, length, ppos);
6542 setup_per_zone_lowmem_reserve();
6547 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6548 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6549 * pagelist can have before it gets flushed back to buddy allocator.
6551 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6552 void __user *buffer, size_t *length, loff_t *ppos)
6555 int old_percpu_pagelist_fraction;
6558 mutex_lock(&pcp_batch_high_lock);
6559 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6561 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6562 if (!write || ret < 0)
6565 /* Sanity checking to avoid pcp imbalance */
6566 if (percpu_pagelist_fraction &&
6567 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6568 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6574 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6577 for_each_populated_zone(zone) {
6580 for_each_possible_cpu(cpu)
6581 pageset_set_high_and_batch(zone,
6582 per_cpu_ptr(zone->pageset, cpu));
6585 mutex_unlock(&pcp_batch_high_lock);
6590 int hashdist = HASHDIST_DEFAULT;
6592 static int __init set_hashdist(char *str)
6596 hashdist = simple_strtoul(str, &str, 0);
6599 __setup("hashdist=", set_hashdist);
6603 * allocate a large system hash table from bootmem
6604 * - it is assumed that the hash table must contain an exact power-of-2
6605 * quantity of entries
6606 * - limit is the number of hash buckets, not the total allocation size
6608 void *__init alloc_large_system_hash(const char *tablename,
6609 unsigned long bucketsize,
6610 unsigned long numentries,
6613 unsigned int *_hash_shift,
6614 unsigned int *_hash_mask,
6615 unsigned long low_limit,
6616 unsigned long high_limit)
6618 unsigned long long max = high_limit;
6619 unsigned long log2qty, size;
6622 /* allow the kernel cmdline to have a say */
6624 /* round applicable memory size up to nearest megabyte */
6625 numentries = nr_kernel_pages;
6627 /* It isn't necessary when PAGE_SIZE >= 1MB */
6628 if (PAGE_SHIFT < 20)
6629 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6631 /* limit to 1 bucket per 2^scale bytes of low memory */
6632 if (scale > PAGE_SHIFT)
6633 numentries >>= (scale - PAGE_SHIFT);
6635 numentries <<= (PAGE_SHIFT - scale);
6637 /* Make sure we've got at least a 0-order allocation.. */
6638 if (unlikely(flags & HASH_SMALL)) {
6639 /* Makes no sense without HASH_EARLY */
6640 WARN_ON(!(flags & HASH_EARLY));
6641 if (!(numentries >> *_hash_shift)) {
6642 numentries = 1UL << *_hash_shift;
6643 BUG_ON(!numentries);
6645 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6646 numentries = PAGE_SIZE / bucketsize;
6648 numentries = roundup_pow_of_two(numentries);
6650 /* limit allocation size to 1/16 total memory by default */
6652 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6653 do_div(max, bucketsize);
6655 max = min(max, 0x80000000ULL);
6657 if (numentries < low_limit)
6658 numentries = low_limit;
6659 if (numentries > max)
6662 log2qty = ilog2(numentries);
6665 size = bucketsize << log2qty;
6666 if (flags & HASH_EARLY)
6667 table = memblock_virt_alloc_nopanic(size, 0);
6669 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6672 * If bucketsize is not a power-of-two, we may free
6673 * some pages at the end of hash table which
6674 * alloc_pages_exact() automatically does
6676 if (get_order(size) < MAX_ORDER) {
6677 table = alloc_pages_exact(size, GFP_ATOMIC);
6678 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6681 } while (!table && size > PAGE_SIZE && --log2qty);
6684 panic("Failed to allocate %s hash table\n", tablename);
6686 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6687 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
6690 *_hash_shift = log2qty;
6692 *_hash_mask = (1 << log2qty) - 1;
6697 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6698 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6701 #ifdef CONFIG_SPARSEMEM
6702 return __pfn_to_section(pfn)->pageblock_flags;
6704 return zone->pageblock_flags;
6705 #endif /* CONFIG_SPARSEMEM */
6708 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6710 #ifdef CONFIG_SPARSEMEM
6711 pfn &= (PAGES_PER_SECTION-1);
6712 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6714 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6715 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6716 #endif /* CONFIG_SPARSEMEM */
6720 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6721 * @page: The page within the block of interest
6722 * @pfn: The target page frame number
6723 * @end_bitidx: The last bit of interest to retrieve
6724 * @mask: mask of bits that the caller is interested in
6726 * Return: pageblock_bits flags
6728 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6729 unsigned long end_bitidx,
6733 unsigned long *bitmap;
6734 unsigned long bitidx, word_bitidx;
6737 zone = page_zone(page);
6738 bitmap = get_pageblock_bitmap(zone, pfn);
6739 bitidx = pfn_to_bitidx(zone, pfn);
6740 word_bitidx = bitidx / BITS_PER_LONG;
6741 bitidx &= (BITS_PER_LONG-1);
6743 word = bitmap[word_bitidx];
6744 bitidx += end_bitidx;
6745 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6749 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6750 * @page: The page within the block of interest
6751 * @flags: The flags to set
6752 * @pfn: The target page frame number
6753 * @end_bitidx: The last bit of interest
6754 * @mask: mask of bits that the caller is interested in
6756 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6758 unsigned long end_bitidx,
6762 unsigned long *bitmap;
6763 unsigned long bitidx, word_bitidx;
6764 unsigned long old_word, word;
6766 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6768 zone = page_zone(page);
6769 bitmap = get_pageblock_bitmap(zone, pfn);
6770 bitidx = pfn_to_bitidx(zone, pfn);
6771 word_bitidx = bitidx / BITS_PER_LONG;
6772 bitidx &= (BITS_PER_LONG-1);
6774 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6776 bitidx += end_bitidx;
6777 mask <<= (BITS_PER_LONG - bitidx - 1);
6778 flags <<= (BITS_PER_LONG - bitidx - 1);
6780 word = READ_ONCE(bitmap[word_bitidx]);
6782 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6783 if (word == old_word)
6790 * This function checks whether pageblock includes unmovable pages or not.
6791 * If @count is not zero, it is okay to include less @count unmovable pages
6793 * PageLRU check without isolation or lru_lock could race so that
6794 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6795 * expect this function should be exact.
6797 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6798 bool skip_hwpoisoned_pages)
6800 unsigned long pfn, iter, found;
6804 * For avoiding noise data, lru_add_drain_all() should be called
6805 * If ZONE_MOVABLE, the zone never contains unmovable pages
6807 if (zone_idx(zone) == ZONE_MOVABLE)
6809 mt = get_pageblock_migratetype(page);
6810 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6813 pfn = page_to_pfn(page);
6814 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6815 unsigned long check = pfn + iter;
6817 if (!pfn_valid_within(check))
6820 page = pfn_to_page(check);
6823 * Hugepages are not in LRU lists, but they're movable.
6824 * We need not scan over tail pages bacause we don't
6825 * handle each tail page individually in migration.
6827 if (PageHuge(page)) {
6828 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6833 * We can't use page_count without pin a page
6834 * because another CPU can free compound page.
6835 * This check already skips compound tails of THP
6836 * because their page->_count is zero at all time.
6838 if (!page_ref_count(page)) {
6839 if (PageBuddy(page))
6840 iter += (1 << page_order(page)) - 1;
6845 * The HWPoisoned page may be not in buddy system, and
6846 * page_count() is not 0.
6848 if (skip_hwpoisoned_pages && PageHWPoison(page))
6854 * If there are RECLAIMABLE pages, we need to check
6855 * it. But now, memory offline itself doesn't call
6856 * shrink_node_slabs() and it still to be fixed.
6859 * If the page is not RAM, page_count()should be 0.
6860 * we don't need more check. This is an _used_ not-movable page.
6862 * The problematic thing here is PG_reserved pages. PG_reserved
6863 * is set to both of a memory hole page and a _used_ kernel
6872 bool is_pageblock_removable_nolock(struct page *page)
6878 * We have to be careful here because we are iterating over memory
6879 * sections which are not zone aware so we might end up outside of
6880 * the zone but still within the section.
6881 * We have to take care about the node as well. If the node is offline
6882 * its NODE_DATA will be NULL - see page_zone.
6884 if (!node_online(page_to_nid(page)))
6887 zone = page_zone(page);
6888 pfn = page_to_pfn(page);
6889 if (!zone_spans_pfn(zone, pfn))
6892 return !has_unmovable_pages(zone, page, 0, true);
6895 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6897 static unsigned long pfn_max_align_down(unsigned long pfn)
6899 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6900 pageblock_nr_pages) - 1);
6903 static unsigned long pfn_max_align_up(unsigned long pfn)
6905 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6906 pageblock_nr_pages));
6909 /* [start, end) must belong to a single zone. */
6910 static int __alloc_contig_migrate_range(struct compact_control *cc,
6911 unsigned long start, unsigned long end)
6913 /* This function is based on compact_zone() from compaction.c. */
6914 unsigned long nr_reclaimed;
6915 unsigned long pfn = start;
6916 unsigned int tries = 0;
6921 while (pfn < end || !list_empty(&cc->migratepages)) {
6922 if (fatal_signal_pending(current)) {
6927 if (list_empty(&cc->migratepages)) {
6928 cc->nr_migratepages = 0;
6929 pfn = isolate_migratepages_range(cc, pfn, end);
6935 } else if (++tries == 5) {
6936 ret = ret < 0 ? ret : -EBUSY;
6940 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6942 cc->nr_migratepages -= nr_reclaimed;
6944 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6945 NULL, 0, cc->mode, MR_CMA);
6948 putback_movable_pages(&cc->migratepages);
6955 * alloc_contig_range() -- tries to allocate given range of pages
6956 * @start: start PFN to allocate
6957 * @end: one-past-the-last PFN to allocate
6958 * @migratetype: migratetype of the underlaying pageblocks (either
6959 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6960 * in range must have the same migratetype and it must
6961 * be either of the two.
6963 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6964 * aligned, however it's the caller's responsibility to guarantee that
6965 * we are the only thread that changes migrate type of pageblocks the
6968 * The PFN range must belong to a single zone.
6970 * Returns zero on success or negative error code. On success all
6971 * pages which PFN is in [start, end) are allocated for the caller and
6972 * need to be freed with free_contig_range().
6974 int alloc_contig_range(unsigned long start, unsigned long end,
6975 unsigned migratetype)
6977 unsigned long outer_start, outer_end;
6981 struct compact_control cc = {
6982 .nr_migratepages = 0,
6984 .zone = page_zone(pfn_to_page(start)),
6985 .mode = MIGRATE_SYNC,
6986 .ignore_skip_hint = true,
6988 INIT_LIST_HEAD(&cc.migratepages);
6991 * What we do here is we mark all pageblocks in range as
6992 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6993 * have different sizes, and due to the way page allocator
6994 * work, we align the range to biggest of the two pages so
6995 * that page allocator won't try to merge buddies from
6996 * different pageblocks and change MIGRATE_ISOLATE to some
6997 * other migration type.
6999 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7000 * migrate the pages from an unaligned range (ie. pages that
7001 * we are interested in). This will put all the pages in
7002 * range back to page allocator as MIGRATE_ISOLATE.
7004 * When this is done, we take the pages in range from page
7005 * allocator removing them from the buddy system. This way
7006 * page allocator will never consider using them.
7008 * This lets us mark the pageblocks back as
7009 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7010 * aligned range but not in the unaligned, original range are
7011 * put back to page allocator so that buddy can use them.
7014 ret = start_isolate_page_range(pfn_max_align_down(start),
7015 pfn_max_align_up(end), migratetype,
7021 * In case of -EBUSY, we'd like to know which page causes problem.
7022 * So, just fall through. We will check it in test_pages_isolated().
7024 ret = __alloc_contig_migrate_range(&cc, start, end);
7025 if (ret && ret != -EBUSY)
7029 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7030 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7031 * more, all pages in [start, end) are free in page allocator.
7032 * What we are going to do is to allocate all pages from
7033 * [start, end) (that is remove them from page allocator).
7035 * The only problem is that pages at the beginning and at the
7036 * end of interesting range may be not aligned with pages that
7037 * page allocator holds, ie. they can be part of higher order
7038 * pages. Because of this, we reserve the bigger range and
7039 * once this is done free the pages we are not interested in.
7041 * We don't have to hold zone->lock here because the pages are
7042 * isolated thus they won't get removed from buddy.
7045 lru_add_drain_all();
7046 drain_all_pages(cc.zone);
7049 outer_start = start;
7050 while (!PageBuddy(pfn_to_page(outer_start))) {
7051 if (++order >= MAX_ORDER) {
7052 outer_start = start;
7055 outer_start &= ~0UL << order;
7058 if (outer_start != start) {
7059 order = page_order(pfn_to_page(outer_start));
7062 * outer_start page could be small order buddy page and
7063 * it doesn't include start page. Adjust outer_start
7064 * in this case to report failed page properly
7065 * on tracepoint in test_pages_isolated()
7067 if (outer_start + (1UL << order) <= start)
7068 outer_start = start;
7071 /* Make sure the range is really isolated. */
7072 if (test_pages_isolated(outer_start, end, false)) {
7073 pr_info("%s: [%lx, %lx) PFNs busy\n",
7074 __func__, outer_start, end);
7079 /* Grab isolated pages from freelists. */
7080 outer_end = isolate_freepages_range(&cc, outer_start, end);
7086 /* Free head and tail (if any) */
7087 if (start != outer_start)
7088 free_contig_range(outer_start, start - outer_start);
7089 if (end != outer_end)
7090 free_contig_range(end, outer_end - end);
7093 undo_isolate_page_range(pfn_max_align_down(start),
7094 pfn_max_align_up(end), migratetype);
7098 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7100 unsigned int count = 0;
7102 for (; nr_pages--; pfn++) {
7103 struct page *page = pfn_to_page(pfn);
7105 count += page_count(page) != 1;
7108 WARN(count != 0, "%d pages are still in use!\n", count);
7112 #ifdef CONFIG_MEMORY_HOTPLUG
7114 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7115 * page high values need to be recalulated.
7117 void __meminit zone_pcp_update(struct zone *zone)
7120 mutex_lock(&pcp_batch_high_lock);
7121 for_each_possible_cpu(cpu)
7122 pageset_set_high_and_batch(zone,
7123 per_cpu_ptr(zone->pageset, cpu));
7124 mutex_unlock(&pcp_batch_high_lock);
7128 void zone_pcp_reset(struct zone *zone)
7130 unsigned long flags;
7132 struct per_cpu_pageset *pset;
7134 /* avoid races with drain_pages() */
7135 local_irq_save(flags);
7136 if (zone->pageset != &boot_pageset) {
7137 for_each_online_cpu(cpu) {
7138 pset = per_cpu_ptr(zone->pageset, cpu);
7139 drain_zonestat(zone, pset);
7141 free_percpu(zone->pageset);
7142 zone->pageset = &boot_pageset;
7144 local_irq_restore(flags);
7147 #ifdef CONFIG_MEMORY_HOTREMOVE
7149 * All pages in the range must be isolated before calling this.
7152 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7156 unsigned int order, i;
7158 unsigned long flags;
7159 /* find the first valid pfn */
7160 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7165 zone = page_zone(pfn_to_page(pfn));
7166 spin_lock_irqsave(&zone->lock, flags);
7168 while (pfn < end_pfn) {
7169 if (!pfn_valid(pfn)) {
7173 page = pfn_to_page(pfn);
7175 * The HWPoisoned page may be not in buddy system, and
7176 * page_count() is not 0.
7178 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7180 SetPageReserved(page);
7184 BUG_ON(page_count(page));
7185 BUG_ON(!PageBuddy(page));
7186 order = page_order(page);
7187 #ifdef CONFIG_DEBUG_VM
7188 pr_info("remove from free list %lx %d %lx\n",
7189 pfn, 1 << order, end_pfn);
7191 list_del(&page->lru);
7192 rmv_page_order(page);
7193 zone->free_area[order].nr_free--;
7194 for (i = 0; i < (1 << order); i++)
7195 SetPageReserved((page+i));
7196 pfn += (1 << order);
7198 spin_unlock_irqrestore(&zone->lock, flags);
7202 bool is_free_buddy_page(struct page *page)
7204 struct zone *zone = page_zone(page);
7205 unsigned long pfn = page_to_pfn(page);
7206 unsigned long flags;
7209 spin_lock_irqsave(&zone->lock, flags);
7210 for (order = 0; order < MAX_ORDER; order++) {
7211 struct page *page_head = page - (pfn & ((1 << order) - 1));
7213 if (PageBuddy(page_head) && page_order(page_head) >= order)
7216 spin_unlock_irqrestore(&zone->lock, flags);
7218 return order < MAX_ORDER;