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 unsigned long max_initialise;
313 /* Always populate low zones for address-contrained allocations */
314 if (zone_end < pgdat_end_pfn(pgdat))
317 * Initialise at least 2G of a node but also take into account that
318 * two large system hashes that can take up 1GB for 0.25TB/node.
320 max_initialise = max(2UL << (30 - PAGE_SHIFT),
321 (pgdat->node_spanned_pages >> 8));
324 if ((*nr_initialised > max_initialise) &&
325 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
326 pgdat->first_deferred_pfn = pfn;
333 static inline void reset_deferred_meminit(pg_data_t *pgdat)
337 static inline bool early_page_uninitialised(unsigned long pfn)
342 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
347 static inline bool update_defer_init(pg_data_t *pgdat,
348 unsigned long pfn, unsigned long zone_end,
349 unsigned long *nr_initialised)
356 void set_pageblock_migratetype(struct page *page, int migratetype)
358 if (unlikely(page_group_by_mobility_disabled &&
359 migratetype < MIGRATE_PCPTYPES))
360 migratetype = MIGRATE_UNMOVABLE;
362 set_pageblock_flags_group(page, (unsigned long)migratetype,
363 PB_migrate, PB_migrate_end);
366 #ifdef CONFIG_DEBUG_VM
367 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
371 unsigned long pfn = page_to_pfn(page);
372 unsigned long sp, start_pfn;
375 seq = zone_span_seqbegin(zone);
376 start_pfn = zone->zone_start_pfn;
377 sp = zone->spanned_pages;
378 if (!zone_spans_pfn(zone, pfn))
380 } while (zone_span_seqretry(zone, seq));
383 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
384 pfn, zone_to_nid(zone), zone->name,
385 start_pfn, start_pfn + sp);
390 static int page_is_consistent(struct zone *zone, struct page *page)
392 if (!pfn_valid_within(page_to_pfn(page)))
394 if (zone != page_zone(page))
400 * Temporary debugging check for pages not lying within a given zone.
402 static int bad_range(struct zone *zone, struct page *page)
404 if (page_outside_zone_boundaries(zone, page))
406 if (!page_is_consistent(zone, page))
412 static inline int bad_range(struct zone *zone, struct page *page)
418 static void bad_page(struct page *page, const char *reason,
419 unsigned long bad_flags)
421 static unsigned long resume;
422 static unsigned long nr_shown;
423 static unsigned long nr_unshown;
425 /* Don't complain about poisoned pages */
426 if (PageHWPoison(page)) {
427 page_mapcount_reset(page); /* remove PageBuddy */
432 * Allow a burst of 60 reports, then keep quiet for that minute;
433 * or allow a steady drip of one report per second.
435 if (nr_shown == 60) {
436 if (time_before(jiffies, resume)) {
442 "BUG: Bad page state: %lu messages suppressed\n",
449 resume = jiffies + 60 * HZ;
451 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
452 current->comm, page_to_pfn(page));
453 __dump_page(page, reason);
454 bad_flags &= page->flags;
456 pr_alert("bad because of flags: %#lx(%pGp)\n",
457 bad_flags, &bad_flags);
458 dump_page_owner(page);
463 /* Leave bad fields for debug, except PageBuddy could make trouble */
464 page_mapcount_reset(page); /* remove PageBuddy */
465 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
469 * Higher-order pages are called "compound pages". They are structured thusly:
471 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
473 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
474 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
476 * The first tail page's ->compound_dtor holds the offset in array of compound
477 * page destructors. See compound_page_dtors.
479 * The first tail page's ->compound_order holds the order of allocation.
480 * This usage means that zero-order pages may not be compound.
483 void free_compound_page(struct page *page)
485 __free_pages_ok(page, compound_order(page));
488 void prep_compound_page(struct page *page, unsigned int order)
491 int nr_pages = 1 << order;
493 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
494 set_compound_order(page, order);
496 for (i = 1; i < nr_pages; i++) {
497 struct page *p = page + i;
498 set_page_count(p, 0);
499 p->mapping = TAIL_MAPPING;
500 set_compound_head(p, page);
502 atomic_set(compound_mapcount_ptr(page), -1);
505 #ifdef CONFIG_DEBUG_PAGEALLOC
506 unsigned int _debug_guardpage_minorder;
507 bool _debug_pagealloc_enabled __read_mostly
508 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
509 EXPORT_SYMBOL(_debug_pagealloc_enabled);
510 bool _debug_guardpage_enabled __read_mostly;
512 static int __init early_debug_pagealloc(char *buf)
517 if (strcmp(buf, "on") == 0)
518 _debug_pagealloc_enabled = true;
520 if (strcmp(buf, "off") == 0)
521 _debug_pagealloc_enabled = false;
525 early_param("debug_pagealloc", early_debug_pagealloc);
527 static bool need_debug_guardpage(void)
529 /* If we don't use debug_pagealloc, we don't need guard page */
530 if (!debug_pagealloc_enabled())
536 static void init_debug_guardpage(void)
538 if (!debug_pagealloc_enabled())
541 _debug_guardpage_enabled = true;
544 struct page_ext_operations debug_guardpage_ops = {
545 .need = need_debug_guardpage,
546 .init = init_debug_guardpage,
549 static int __init debug_guardpage_minorder_setup(char *buf)
553 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
554 pr_err("Bad debug_guardpage_minorder value\n");
557 _debug_guardpage_minorder = res;
558 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
561 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
563 static inline void set_page_guard(struct zone *zone, struct page *page,
564 unsigned int order, int migratetype)
566 struct page_ext *page_ext;
568 if (!debug_guardpage_enabled())
571 page_ext = lookup_page_ext(page);
572 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
574 INIT_LIST_HEAD(&page->lru);
575 set_page_private(page, order);
576 /* Guard pages are not available for any usage */
577 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
580 static inline void clear_page_guard(struct zone *zone, struct page *page,
581 unsigned int order, int migratetype)
583 struct page_ext *page_ext;
585 if (!debug_guardpage_enabled())
588 page_ext = lookup_page_ext(page);
589 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
591 set_page_private(page, 0);
592 if (!is_migrate_isolate(migratetype))
593 __mod_zone_freepage_state(zone, (1 << order), migratetype);
596 struct page_ext_operations debug_guardpage_ops = { NULL, };
597 static inline void set_page_guard(struct zone *zone, struct page *page,
598 unsigned int order, int migratetype) {}
599 static inline void clear_page_guard(struct zone *zone, struct page *page,
600 unsigned int order, int migratetype) {}
603 static inline void set_page_order(struct page *page, unsigned int order)
605 set_page_private(page, order);
606 __SetPageBuddy(page);
609 static inline void rmv_page_order(struct page *page)
611 __ClearPageBuddy(page);
612 set_page_private(page, 0);
616 * This function checks whether a page is free && is the buddy
617 * we can do coalesce a page and its buddy if
618 * (a) the buddy is not in a hole &&
619 * (b) the buddy is in the buddy system &&
620 * (c) a page and its buddy have the same order &&
621 * (d) a page and its buddy are in the same zone.
623 * For recording whether a page is in the buddy system, we set ->_mapcount
624 * PAGE_BUDDY_MAPCOUNT_VALUE.
625 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
626 * serialized by zone->lock.
628 * For recording page's order, we use page_private(page).
630 static inline int page_is_buddy(struct page *page, struct page *buddy,
633 if (!pfn_valid_within(page_to_pfn(buddy)))
636 if (page_is_guard(buddy) && page_order(buddy) == order) {
637 if (page_zone_id(page) != page_zone_id(buddy))
640 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
645 if (PageBuddy(buddy) && page_order(buddy) == order) {
647 * zone check is done late to avoid uselessly
648 * calculating zone/node ids for pages that could
651 if (page_zone_id(page) != page_zone_id(buddy))
654 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
662 * Freeing function for a buddy system allocator.
664 * The concept of a buddy system is to maintain direct-mapped table
665 * (containing bit values) for memory blocks of various "orders".
666 * The bottom level table contains the map for the smallest allocatable
667 * units of memory (here, pages), and each level above it describes
668 * pairs of units from the levels below, hence, "buddies".
669 * At a high level, all that happens here is marking the table entry
670 * at the bottom level available, and propagating the changes upward
671 * as necessary, plus some accounting needed to play nicely with other
672 * parts of the VM system.
673 * At each level, we keep a list of pages, which are heads of continuous
674 * free pages of length of (1 << order) and marked with _mapcount
675 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
677 * So when we are allocating or freeing one, we can derive the state of the
678 * other. That is, if we allocate a small block, and both were
679 * free, the remainder of the region must be split into blocks.
680 * If a block is freed, and its buddy is also free, then this
681 * triggers coalescing into a block of larger size.
686 static inline void __free_one_page(struct page *page,
688 struct zone *zone, unsigned int order,
691 unsigned long page_idx;
692 unsigned long combined_idx;
693 unsigned long uninitialized_var(buddy_idx);
695 unsigned int max_order;
697 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
699 VM_BUG_ON(!zone_is_initialized(zone));
700 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
702 VM_BUG_ON(migratetype == -1);
703 if (likely(!is_migrate_isolate(migratetype)))
704 __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);
712 while (order < max_order - 1) {
713 buddy_idx = __find_buddy_index(page_idx, order);
714 buddy = page + (buddy_idx - page_idx);
715 if (!page_is_buddy(page, buddy, order))
718 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
719 * merge with it and move up one order.
721 if (page_is_guard(buddy)) {
722 clear_page_guard(zone, buddy, order, migratetype);
724 list_del(&buddy->lru);
725 zone->free_area[order].nr_free--;
726 rmv_page_order(buddy);
728 combined_idx = buddy_idx & page_idx;
729 page = page + (combined_idx - page_idx);
730 page_idx = combined_idx;
733 if (max_order < MAX_ORDER) {
734 /* If we are here, it means order is >= pageblock_order.
735 * We want to prevent merge between freepages on isolate
736 * pageblock and normal pageblock. Without this, pageblock
737 * isolation could cause incorrect freepage or CMA accounting.
739 * We don't want to hit this code for the more frequent
742 if (unlikely(has_isolate_pageblock(zone))) {
745 buddy_idx = __find_buddy_index(page_idx, order);
746 buddy = page + (buddy_idx - page_idx);
747 buddy_mt = get_pageblock_migratetype(buddy);
749 if (migratetype != buddy_mt
750 && (is_migrate_isolate(migratetype) ||
751 is_migrate_isolate(buddy_mt)))
755 goto continue_merging;
759 set_page_order(page, order);
762 * If this is not the largest possible page, check if the buddy
763 * of the next-highest order is free. If it is, it's possible
764 * that pages are being freed that will coalesce soon. In case,
765 * that is happening, add the free page to the tail of the list
766 * so it's less likely to be used soon and more likely to be merged
767 * as a higher order page
769 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
770 struct page *higher_page, *higher_buddy;
771 combined_idx = buddy_idx & page_idx;
772 higher_page = page + (combined_idx - page_idx);
773 buddy_idx = __find_buddy_index(combined_idx, order + 1);
774 higher_buddy = higher_page + (buddy_idx - combined_idx);
775 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
776 list_add_tail(&page->lru,
777 &zone->free_area[order].free_list[migratetype]);
782 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
784 zone->free_area[order].nr_free++;
787 static inline int free_pages_check(struct page *page)
789 const char *bad_reason = NULL;
790 unsigned long bad_flags = 0;
792 if (unlikely(atomic_read(&page->_mapcount) != -1))
793 bad_reason = "nonzero mapcount";
794 if (unlikely(page->mapping != NULL))
795 bad_reason = "non-NULL mapping";
796 if (unlikely(page_ref_count(page) != 0))
797 bad_reason = "nonzero _refcount";
798 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
799 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
800 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
803 if (unlikely(page->mem_cgroup))
804 bad_reason = "page still charged to cgroup";
806 if (unlikely(bad_reason)) {
807 bad_page(page, bad_reason, bad_flags);
810 page_cpupid_reset_last(page);
811 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
812 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
817 * Frees a number of pages from the PCP lists
818 * Assumes all pages on list are in same zone, and of same order.
819 * count is the number of pages to free.
821 * If the zone was previously in an "all pages pinned" state then look to
822 * see if this freeing clears that state.
824 * And clear the zone's pages_scanned counter, to hold off the "all pages are
825 * pinned" detection logic.
827 static void free_pcppages_bulk(struct zone *zone, int count,
828 struct per_cpu_pages *pcp)
833 unsigned long nr_scanned;
835 spin_lock(&zone->lock);
836 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
838 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
842 struct list_head *list;
845 * Remove pages from lists in a round-robin fashion. A
846 * batch_free count is maintained that is incremented when an
847 * empty list is encountered. This is so more pages are freed
848 * off fuller lists instead of spinning excessively around empty
853 if (++migratetype == MIGRATE_PCPTYPES)
855 list = &pcp->lists[migratetype];
856 } while (list_empty(list));
858 /* This is the only non-empty list. Free them all. */
859 if (batch_free == MIGRATE_PCPTYPES)
860 batch_free = to_free;
863 int mt; /* migratetype of the to-be-freed page */
865 page = list_last_entry(list, struct page, lru);
866 /* must delete as __free_one_page list manipulates */
867 list_del(&page->lru);
869 mt = get_pcppage_migratetype(page);
870 /* MIGRATE_ISOLATE page should not go to pcplists */
871 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
872 /* Pageblock could have been isolated meanwhile */
873 if (unlikely(has_isolate_pageblock(zone)))
874 mt = get_pageblock_migratetype(page);
876 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
877 trace_mm_page_pcpu_drain(page, 0, mt);
878 } while (--to_free && --batch_free && !list_empty(list));
880 spin_unlock(&zone->lock);
883 static void free_one_page(struct zone *zone,
884 struct page *page, unsigned long pfn,
888 unsigned long nr_scanned;
889 spin_lock(&zone->lock);
890 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
892 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
894 if (unlikely(has_isolate_pageblock(zone) ||
895 is_migrate_isolate(migratetype))) {
896 migratetype = get_pfnblock_migratetype(page, pfn);
898 __free_one_page(page, pfn, zone, order, migratetype);
899 spin_unlock(&zone->lock);
902 static int free_tail_pages_check(struct page *head_page, struct page *page)
907 * We rely page->lru.next never has bit 0 set, unless the page
908 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
910 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
912 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
916 switch (page - head_page) {
918 /* the first tail page: ->mapping is compound_mapcount() */
919 if (unlikely(compound_mapcount(page))) {
920 bad_page(page, "nonzero compound_mapcount", 0);
926 * the second tail page: ->mapping is
927 * page_deferred_list().next -- ignore value.
931 if (page->mapping != TAIL_MAPPING) {
932 bad_page(page, "corrupted mapping in tail page", 0);
937 if (unlikely(!PageTail(page))) {
938 bad_page(page, "PageTail not set", 0);
941 if (unlikely(compound_head(page) != head_page)) {
942 bad_page(page, "compound_head not consistent", 0);
947 page->mapping = NULL;
948 clear_compound_head(page);
952 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
953 unsigned long zone, int nid)
955 set_page_links(page, zone, nid, pfn);
956 init_page_count(page);
957 page_mapcount_reset(page);
958 page_cpupid_reset_last(page);
960 INIT_LIST_HEAD(&page->lru);
961 #ifdef WANT_PAGE_VIRTUAL
962 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
963 if (!is_highmem_idx(zone))
964 set_page_address(page, __va(pfn << PAGE_SHIFT));
968 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
971 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
974 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
975 static void init_reserved_page(unsigned long pfn)
980 if (!early_page_uninitialised(pfn))
983 nid = early_pfn_to_nid(pfn);
984 pgdat = NODE_DATA(nid);
986 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
987 struct zone *zone = &pgdat->node_zones[zid];
989 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
992 __init_single_pfn(pfn, zid, nid);
995 static inline void init_reserved_page(unsigned long pfn)
998 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1001 * Initialised pages do not have PageReserved set. This function is
1002 * called for each range allocated by the bootmem allocator and
1003 * marks the pages PageReserved. The remaining valid pages are later
1004 * sent to the buddy page allocator.
1006 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
1008 unsigned long start_pfn = PFN_DOWN(start);
1009 unsigned long end_pfn = PFN_UP(end);
1011 for (; start_pfn < end_pfn; start_pfn++) {
1012 if (pfn_valid(start_pfn)) {
1013 struct page *page = pfn_to_page(start_pfn);
1015 init_reserved_page(start_pfn);
1017 /* Avoid false-positive PageTail() */
1018 INIT_LIST_HEAD(&page->lru);
1020 SetPageReserved(page);
1025 static bool free_pages_prepare(struct page *page, unsigned int order)
1029 VM_BUG_ON_PAGE(PageTail(page), page);
1031 trace_mm_page_free(page, order);
1032 kmemcheck_free_shadow(page, order);
1033 kasan_free_pages(page, order);
1036 * Check tail pages before head page information is cleared to
1037 * avoid checking PageCompound for order-0 pages.
1039 if (unlikely(order)) {
1040 bool compound = PageCompound(page);
1043 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1045 for (i = 1; i < (1 << order); i++) {
1047 bad += free_tail_pages_check(page, page + i);
1048 bad += free_pages_check(page + i);
1051 if (PageAnonHead(page))
1052 page->mapping = NULL;
1053 bad += free_pages_check(page);
1057 reset_page_owner(page, order);
1059 if (!PageHighMem(page)) {
1060 debug_check_no_locks_freed(page_address(page),
1061 PAGE_SIZE << order);
1062 debug_check_no_obj_freed(page_address(page),
1063 PAGE_SIZE << order);
1065 arch_free_page(page, order);
1066 kernel_poison_pages(page, 1 << order, 0);
1067 kernel_map_pages(page, 1 << order, 0);
1072 static void __free_pages_ok(struct page *page, unsigned int order)
1074 unsigned long flags;
1076 unsigned long pfn = page_to_pfn(page);
1078 if (!free_pages_prepare(page, order))
1081 migratetype = get_pfnblock_migratetype(page, pfn);
1082 local_irq_save(flags);
1083 __count_vm_events(PGFREE, 1 << order);
1084 free_one_page(page_zone(page), page, pfn, order, migratetype);
1085 local_irq_restore(flags);
1088 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1090 unsigned int nr_pages = 1 << order;
1091 struct page *p = page;
1095 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1097 __ClearPageReserved(p);
1098 set_page_count(p, 0);
1100 __ClearPageReserved(p);
1101 set_page_count(p, 0);
1103 page_zone(page)->managed_pages += nr_pages;
1104 set_page_refcounted(page);
1105 __free_pages(page, order);
1108 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1109 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1111 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1113 int __meminit early_pfn_to_nid(unsigned long pfn)
1115 static DEFINE_SPINLOCK(early_pfn_lock);
1118 spin_lock(&early_pfn_lock);
1119 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1122 spin_unlock(&early_pfn_lock);
1128 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1129 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1130 struct mminit_pfnnid_cache *state)
1134 nid = __early_pfn_to_nid(pfn, state);
1135 if (nid >= 0 && nid != node)
1140 /* Only safe to use early in boot when initialisation is single-threaded */
1141 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1143 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1148 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1152 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1153 struct mminit_pfnnid_cache *state)
1160 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1163 if (early_page_uninitialised(pfn))
1165 return __free_pages_boot_core(page, order);
1169 * Check that the whole (or subset of) a pageblock given by the interval of
1170 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1171 * with the migration of free compaction scanner. The scanners then need to
1172 * use only pfn_valid_within() check for arches that allow holes within
1175 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1177 * It's possible on some configurations to have a setup like node0 node1 node0
1178 * i.e. it's possible that all pages within a zones range of pages do not
1179 * belong to a single zone. We assume that a border between node0 and node1
1180 * can occur within a single pageblock, but not a node0 node1 node0
1181 * interleaving within a single pageblock. It is therefore sufficient to check
1182 * the first and last page of a pageblock and avoid checking each individual
1183 * page in a pageblock.
1185 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1186 unsigned long end_pfn, struct zone *zone)
1188 struct page *start_page;
1189 struct page *end_page;
1191 /* end_pfn is one past the range we are checking */
1194 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1197 start_page = pfn_to_page(start_pfn);
1199 if (page_zone(start_page) != zone)
1202 end_page = pfn_to_page(end_pfn);
1204 /* This gives a shorter code than deriving page_zone(end_page) */
1205 if (page_zone_id(start_page) != page_zone_id(end_page))
1211 void set_zone_contiguous(struct zone *zone)
1213 unsigned long block_start_pfn = zone->zone_start_pfn;
1214 unsigned long block_end_pfn;
1216 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1217 for (; block_start_pfn < zone_end_pfn(zone);
1218 block_start_pfn = block_end_pfn,
1219 block_end_pfn += pageblock_nr_pages) {
1221 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1223 if (!__pageblock_pfn_to_page(block_start_pfn,
1224 block_end_pfn, zone))
1228 /* We confirm that there is no hole */
1229 zone->contiguous = true;
1232 void clear_zone_contiguous(struct zone *zone)
1234 zone->contiguous = false;
1237 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1238 static void __init deferred_free_range(struct page *page,
1239 unsigned long pfn, int nr_pages)
1246 /* Free a large naturally-aligned chunk if possible */
1247 if (nr_pages == MAX_ORDER_NR_PAGES &&
1248 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1249 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1250 __free_pages_boot_core(page, MAX_ORDER-1);
1254 for (i = 0; i < nr_pages; i++, page++)
1255 __free_pages_boot_core(page, 0);
1258 /* Completion tracking for deferred_init_memmap() threads */
1259 static atomic_t pgdat_init_n_undone __initdata;
1260 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1262 static inline void __init pgdat_init_report_one_done(void)
1264 if (atomic_dec_and_test(&pgdat_init_n_undone))
1265 complete(&pgdat_init_all_done_comp);
1268 /* Initialise remaining memory on a node */
1269 static int __init deferred_init_memmap(void *data)
1271 pg_data_t *pgdat = data;
1272 int nid = pgdat->node_id;
1273 struct mminit_pfnnid_cache nid_init_state = { };
1274 unsigned long start = jiffies;
1275 unsigned long nr_pages = 0;
1276 unsigned long walk_start, walk_end;
1279 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1280 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1282 if (first_init_pfn == ULONG_MAX) {
1283 pgdat_init_report_one_done();
1287 /* Bind memory initialisation thread to a local node if possible */
1288 if (!cpumask_empty(cpumask))
1289 set_cpus_allowed_ptr(current, cpumask);
1291 /* Sanity check boundaries */
1292 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1293 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1294 pgdat->first_deferred_pfn = ULONG_MAX;
1296 /* Only the highest zone is deferred so find it */
1297 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1298 zone = pgdat->node_zones + zid;
1299 if (first_init_pfn < zone_end_pfn(zone))
1303 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1304 unsigned long pfn, end_pfn;
1305 struct page *page = NULL;
1306 struct page *free_base_page = NULL;
1307 unsigned long free_base_pfn = 0;
1310 end_pfn = min(walk_end, zone_end_pfn(zone));
1311 pfn = first_init_pfn;
1312 if (pfn < walk_start)
1314 if (pfn < zone->zone_start_pfn)
1315 pfn = zone->zone_start_pfn;
1317 for (; pfn < end_pfn; pfn++) {
1318 if (!pfn_valid_within(pfn))
1322 * Ensure pfn_valid is checked every
1323 * MAX_ORDER_NR_PAGES for memory holes
1325 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1326 if (!pfn_valid(pfn)) {
1332 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1337 /* Minimise pfn page lookups and scheduler checks */
1338 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1341 nr_pages += nr_to_free;
1342 deferred_free_range(free_base_page,
1343 free_base_pfn, nr_to_free);
1344 free_base_page = NULL;
1345 free_base_pfn = nr_to_free = 0;
1347 page = pfn_to_page(pfn);
1352 VM_BUG_ON(page_zone(page) != zone);
1356 __init_single_page(page, pfn, zid, nid);
1357 if (!free_base_page) {
1358 free_base_page = page;
1359 free_base_pfn = pfn;
1364 /* Where possible, batch up pages for a single free */
1367 /* Free the current block of pages to allocator */
1368 nr_pages += nr_to_free;
1369 deferred_free_range(free_base_page, free_base_pfn,
1371 free_base_page = NULL;
1372 free_base_pfn = nr_to_free = 0;
1375 first_init_pfn = max(end_pfn, first_init_pfn);
1378 /* Sanity check that the next zone really is unpopulated */
1379 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1381 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1382 jiffies_to_msecs(jiffies - start));
1384 pgdat_init_report_one_done();
1387 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1389 void __init page_alloc_init_late(void)
1393 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1396 /* There will be num_node_state(N_MEMORY) threads */
1397 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1398 for_each_node_state(nid, N_MEMORY) {
1399 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1402 /* Block until all are initialised */
1403 wait_for_completion(&pgdat_init_all_done_comp);
1405 /* Reinit limits that are based on free pages after the kernel is up */
1406 files_maxfiles_init();
1409 for_each_populated_zone(zone)
1410 set_zone_contiguous(zone);
1414 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1415 void __init init_cma_reserved_pageblock(struct page *page)
1417 unsigned i = pageblock_nr_pages;
1418 struct page *p = page;
1421 __ClearPageReserved(p);
1422 set_page_count(p, 0);
1425 set_pageblock_migratetype(page, MIGRATE_CMA);
1427 if (pageblock_order >= MAX_ORDER) {
1428 i = pageblock_nr_pages;
1431 set_page_refcounted(p);
1432 __free_pages(p, MAX_ORDER - 1);
1433 p += MAX_ORDER_NR_PAGES;
1434 } while (i -= MAX_ORDER_NR_PAGES);
1436 set_page_refcounted(page);
1437 __free_pages(page, pageblock_order);
1440 adjust_managed_page_count(page, pageblock_nr_pages);
1445 * The order of subdivision here is critical for the IO subsystem.
1446 * Please do not alter this order without good reasons and regression
1447 * testing. Specifically, as large blocks of memory are subdivided,
1448 * the order in which smaller blocks are delivered depends on the order
1449 * they're subdivided in this function. This is the primary factor
1450 * influencing the order in which pages are delivered to the IO
1451 * subsystem according to empirical testing, and this is also justified
1452 * by considering the behavior of a buddy system containing a single
1453 * large block of memory acted on by a series of small allocations.
1454 * This behavior is a critical factor in sglist merging's success.
1458 static inline void expand(struct zone *zone, struct page *page,
1459 int low, int high, struct free_area *area,
1462 unsigned long size = 1 << high;
1464 while (high > low) {
1468 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1470 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1471 debug_guardpage_enabled() &&
1472 high < debug_guardpage_minorder()) {
1474 * Mark as guard pages (or page), that will allow to
1475 * merge back to allocator when buddy will be freed.
1476 * Corresponding page table entries will not be touched,
1477 * pages will stay not present in virtual address space
1479 set_page_guard(zone, &page[size], high, migratetype);
1482 list_add(&page[size].lru, &area->free_list[migratetype]);
1484 set_page_order(&page[size], high);
1489 * This page is about to be returned from the page allocator
1491 static inline int check_new_page(struct page *page)
1493 const char *bad_reason = NULL;
1494 unsigned long bad_flags = 0;
1496 if (unlikely(atomic_read(&page->_mapcount) != -1))
1497 bad_reason = "nonzero mapcount";
1498 if (unlikely(page->mapping != NULL))
1499 bad_reason = "non-NULL mapping";
1500 if (unlikely(page_ref_count(page) != 0))
1501 bad_reason = "nonzero _count";
1502 if (unlikely(page->flags & __PG_HWPOISON)) {
1503 bad_reason = "HWPoisoned (hardware-corrupted)";
1504 bad_flags = __PG_HWPOISON;
1506 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1507 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1508 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1511 if (unlikely(page->mem_cgroup))
1512 bad_reason = "page still charged to cgroup";
1514 if (unlikely(bad_reason)) {
1515 bad_page(page, bad_reason, bad_flags);
1521 static inline bool free_pages_prezeroed(bool poisoned)
1523 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1524 page_poisoning_enabled() && poisoned;
1527 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1531 bool poisoned = true;
1533 for (i = 0; i < (1 << order); i++) {
1534 struct page *p = page + i;
1535 if (unlikely(check_new_page(p)))
1538 poisoned &= page_is_poisoned(p);
1541 set_page_private(page, 0);
1542 set_page_refcounted(page);
1544 arch_alloc_page(page, order);
1545 kernel_map_pages(page, 1 << order, 1);
1546 kernel_poison_pages(page, 1 << order, 1);
1547 kasan_alloc_pages(page, order);
1549 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1550 for (i = 0; i < (1 << order); i++)
1551 clear_highpage(page + i);
1553 if (order && (gfp_flags & __GFP_COMP))
1554 prep_compound_page(page, order);
1556 set_page_owner(page, order, gfp_flags);
1559 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1560 * allocate the page. The expectation is that the caller is taking
1561 * steps that will free more memory. The caller should avoid the page
1562 * being used for !PFMEMALLOC purposes.
1564 if (alloc_flags & ALLOC_NO_WATERMARKS)
1565 set_page_pfmemalloc(page);
1567 clear_page_pfmemalloc(page);
1573 * Go through the free lists for the given migratetype and remove
1574 * the smallest available page from the freelists
1577 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1580 unsigned int current_order;
1581 struct free_area *area;
1584 /* Find a page of the appropriate size in the preferred list */
1585 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1586 area = &(zone->free_area[current_order]);
1587 page = list_first_entry_or_null(&area->free_list[migratetype],
1591 list_del(&page->lru);
1592 rmv_page_order(page);
1594 expand(zone, page, order, current_order, area, migratetype);
1595 set_pcppage_migratetype(page, migratetype);
1604 * This array describes the order lists are fallen back to when
1605 * the free lists for the desirable migrate type are depleted
1607 static int fallbacks[MIGRATE_TYPES][4] = {
1608 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1609 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1610 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1612 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1614 #ifdef CONFIG_MEMORY_ISOLATION
1615 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1620 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1623 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1626 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1627 unsigned int order) { return NULL; }
1631 * Move the free pages in a range to the free lists of the requested type.
1632 * Note that start_page and end_pages are not aligned on a pageblock
1633 * boundary. If alignment is required, use move_freepages_block()
1635 int move_freepages(struct zone *zone,
1636 struct page *start_page, struct page *end_page,
1641 int pages_moved = 0;
1643 #ifndef CONFIG_HOLES_IN_ZONE
1645 * page_zone is not safe to call in this context when
1646 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1647 * anyway as we check zone boundaries in move_freepages_block().
1648 * Remove at a later date when no bug reports exist related to
1649 * grouping pages by mobility
1651 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1654 for (page = start_page; page <= end_page;) {
1655 /* Make sure we are not inadvertently changing nodes */
1656 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1658 if (!pfn_valid_within(page_to_pfn(page))) {
1663 if (!PageBuddy(page)) {
1668 order = page_order(page);
1669 list_move(&page->lru,
1670 &zone->free_area[order].free_list[migratetype]);
1672 pages_moved += 1 << order;
1678 int move_freepages_block(struct zone *zone, struct page *page,
1681 unsigned long start_pfn, end_pfn;
1682 struct page *start_page, *end_page;
1684 start_pfn = page_to_pfn(page);
1685 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1686 start_page = pfn_to_page(start_pfn);
1687 end_page = start_page + pageblock_nr_pages - 1;
1688 end_pfn = start_pfn + pageblock_nr_pages - 1;
1690 /* Do not cross zone boundaries */
1691 if (!zone_spans_pfn(zone, start_pfn))
1693 if (!zone_spans_pfn(zone, end_pfn))
1696 return move_freepages(zone, start_page, end_page, migratetype);
1699 static void change_pageblock_range(struct page *pageblock_page,
1700 int start_order, int migratetype)
1702 int nr_pageblocks = 1 << (start_order - pageblock_order);
1704 while (nr_pageblocks--) {
1705 set_pageblock_migratetype(pageblock_page, migratetype);
1706 pageblock_page += pageblock_nr_pages;
1711 * When we are falling back to another migratetype during allocation, try to
1712 * steal extra free pages from the same pageblocks to satisfy further
1713 * allocations, instead of polluting multiple pageblocks.
1715 * If we are stealing a relatively large buddy page, it is likely there will
1716 * be more free pages in the pageblock, so try to steal them all. For
1717 * reclaimable and unmovable allocations, we steal regardless of page size,
1718 * as fragmentation caused by those allocations polluting movable pageblocks
1719 * is worse than movable allocations stealing from unmovable and reclaimable
1722 static bool can_steal_fallback(unsigned int order, int start_mt)
1725 * Leaving this order check is intended, although there is
1726 * relaxed order check in next check. The reason is that
1727 * we can actually steal whole pageblock if this condition met,
1728 * but, below check doesn't guarantee it and that is just heuristic
1729 * so could be changed anytime.
1731 if (order >= pageblock_order)
1734 if (order >= pageblock_order / 2 ||
1735 start_mt == MIGRATE_RECLAIMABLE ||
1736 start_mt == MIGRATE_UNMOVABLE ||
1737 page_group_by_mobility_disabled)
1744 * This function implements actual steal behaviour. If order is large enough,
1745 * we can steal whole pageblock. If not, we first move freepages in this
1746 * pageblock and check whether half of pages are moved or not. If half of
1747 * pages are moved, we can change migratetype of pageblock and permanently
1748 * use it's pages as requested migratetype in the future.
1750 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1753 unsigned int current_order = page_order(page);
1756 /* Take ownership for orders >= pageblock_order */
1757 if (current_order >= pageblock_order) {
1758 change_pageblock_range(page, current_order, start_type);
1762 pages = move_freepages_block(zone, page, start_type);
1764 /* Claim the whole block if over half of it is free */
1765 if (pages >= (1 << (pageblock_order-1)) ||
1766 page_group_by_mobility_disabled)
1767 set_pageblock_migratetype(page, start_type);
1771 * Check whether there is a suitable fallback freepage with requested order.
1772 * If only_stealable is true, this function returns fallback_mt only if
1773 * we can steal other freepages all together. This would help to reduce
1774 * fragmentation due to mixed migratetype pages in one pageblock.
1776 int find_suitable_fallback(struct free_area *area, unsigned int order,
1777 int migratetype, bool only_stealable, bool *can_steal)
1782 if (area->nr_free == 0)
1787 fallback_mt = fallbacks[migratetype][i];
1788 if (fallback_mt == MIGRATE_TYPES)
1791 if (list_empty(&area->free_list[fallback_mt]))
1794 if (can_steal_fallback(order, migratetype))
1797 if (!only_stealable)
1808 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1809 * there are no empty page blocks that contain a page with a suitable order
1811 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
1812 unsigned int alloc_order)
1815 unsigned long max_managed, flags;
1818 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1819 * Check is race-prone but harmless.
1821 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
1822 if (zone->nr_reserved_highatomic >= max_managed)
1825 spin_lock_irqsave(&zone->lock, flags);
1827 /* Recheck the nr_reserved_highatomic limit under the lock */
1828 if (zone->nr_reserved_highatomic >= max_managed)
1832 mt = get_pageblock_migratetype(page);
1833 if (mt != MIGRATE_HIGHATOMIC &&
1834 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
1835 zone->nr_reserved_highatomic += pageblock_nr_pages;
1836 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
1837 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
1841 spin_unlock_irqrestore(&zone->lock, flags);
1845 * Used when an allocation is about to fail under memory pressure. This
1846 * potentially hurts the reliability of high-order allocations when under
1847 * intense memory pressure but failed atomic allocations should be easier
1848 * to recover from than an OOM.
1850 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
1852 struct zonelist *zonelist = ac->zonelist;
1853 unsigned long flags;
1859 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
1861 /* Preserve at least one pageblock */
1862 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
1865 spin_lock_irqsave(&zone->lock, flags);
1866 for (order = 0; order < MAX_ORDER; order++) {
1867 struct free_area *area = &(zone->free_area[order]);
1869 page = list_first_entry_or_null(
1870 &area->free_list[MIGRATE_HIGHATOMIC],
1876 * It should never happen but changes to locking could
1877 * inadvertently allow a per-cpu drain to add pages
1878 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1879 * and watch for underflows.
1881 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
1882 zone->nr_reserved_highatomic);
1885 * Convert to ac->migratetype and avoid the normal
1886 * pageblock stealing heuristics. Minimally, the caller
1887 * is doing the work and needs the pages. More
1888 * importantly, if the block was always converted to
1889 * MIGRATE_UNMOVABLE or another type then the number
1890 * of pageblocks that cannot be completely freed
1893 set_pageblock_migratetype(page, ac->migratetype);
1894 move_freepages_block(zone, page, ac->migratetype);
1895 spin_unlock_irqrestore(&zone->lock, flags);
1898 spin_unlock_irqrestore(&zone->lock, flags);
1902 /* Remove an element from the buddy allocator from the fallback list */
1903 static inline struct page *
1904 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1906 struct free_area *area;
1907 unsigned int current_order;
1912 /* Find the largest possible block of pages in the other list */
1913 for (current_order = MAX_ORDER-1;
1914 current_order >= order && current_order <= MAX_ORDER-1;
1916 area = &(zone->free_area[current_order]);
1917 fallback_mt = find_suitable_fallback(area, current_order,
1918 start_migratetype, false, &can_steal);
1919 if (fallback_mt == -1)
1922 page = list_first_entry(&area->free_list[fallback_mt],
1925 steal_suitable_fallback(zone, page, start_migratetype);
1927 /* Remove the page from the freelists */
1929 list_del(&page->lru);
1930 rmv_page_order(page);
1932 expand(zone, page, order, current_order, area,
1935 * The pcppage_migratetype may differ from pageblock's
1936 * migratetype depending on the decisions in
1937 * find_suitable_fallback(). This is OK as long as it does not
1938 * differ for MIGRATE_CMA pageblocks. Those can be used as
1939 * fallback only via special __rmqueue_cma_fallback() function
1941 set_pcppage_migratetype(page, start_migratetype);
1943 trace_mm_page_alloc_extfrag(page, order, current_order,
1944 start_migratetype, fallback_mt);
1953 * Do the hard work of removing an element from the buddy allocator.
1954 * Call me with the zone->lock already held.
1956 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1961 page = __rmqueue_smallest(zone, order, migratetype);
1962 if (unlikely(!page)) {
1963 if (migratetype == MIGRATE_MOVABLE)
1964 page = __rmqueue_cma_fallback(zone, order);
1967 page = __rmqueue_fallback(zone, order, migratetype);
1970 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1975 * Obtain a specified number of elements from the buddy allocator, all under
1976 * a single hold of the lock, for efficiency. Add them to the supplied list.
1977 * Returns the number of new pages which were placed at *list.
1979 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1980 unsigned long count, struct list_head *list,
1981 int migratetype, bool cold)
1985 spin_lock(&zone->lock);
1986 for (i = 0; i < count; ++i) {
1987 struct page *page = __rmqueue(zone, order, migratetype);
1988 if (unlikely(page == NULL))
1992 * Split buddy pages returned by expand() are received here
1993 * in physical page order. The page is added to the callers and
1994 * list and the list head then moves forward. From the callers
1995 * perspective, the linked list is ordered by page number in
1996 * some conditions. This is useful for IO devices that can
1997 * merge IO requests if the physical pages are ordered
2001 list_add(&page->lru, list);
2003 list_add_tail(&page->lru, list);
2005 if (is_migrate_cma(get_pcppage_migratetype(page)))
2006 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2009 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2010 spin_unlock(&zone->lock);
2016 * Called from the vmstat counter updater to drain pagesets of this
2017 * currently executing processor on remote nodes after they have
2020 * Note that this function must be called with the thread pinned to
2021 * a single processor.
2023 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2025 unsigned long flags;
2026 int to_drain, batch;
2028 local_irq_save(flags);
2029 batch = READ_ONCE(pcp->batch);
2030 to_drain = min(pcp->count, batch);
2032 free_pcppages_bulk(zone, to_drain, pcp);
2033 pcp->count -= to_drain;
2035 local_irq_restore(flags);
2040 * Drain pcplists of the indicated processor and zone.
2042 * The processor must either be the current processor and the
2043 * thread pinned to the current processor or a processor that
2046 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2048 unsigned long flags;
2049 struct per_cpu_pageset *pset;
2050 struct per_cpu_pages *pcp;
2052 local_irq_save(flags);
2053 pset = per_cpu_ptr(zone->pageset, cpu);
2057 free_pcppages_bulk(zone, pcp->count, pcp);
2060 local_irq_restore(flags);
2064 * Drain pcplists of all zones on the indicated processor.
2066 * The processor must either be the current processor and the
2067 * thread pinned to the current processor or a processor that
2070 static void drain_pages(unsigned int cpu)
2074 for_each_populated_zone(zone) {
2075 drain_pages_zone(cpu, zone);
2080 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2082 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2083 * the single zone's pages.
2085 void drain_local_pages(struct zone *zone)
2087 int cpu = smp_processor_id();
2090 drain_pages_zone(cpu, zone);
2096 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2098 * When zone parameter is non-NULL, spill just the single zone's pages.
2100 * Note that this code is protected against sending an IPI to an offline
2101 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2102 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2103 * nothing keeps CPUs from showing up after we populated the cpumask and
2104 * before the call to on_each_cpu_mask().
2106 void drain_all_pages(struct zone *zone)
2111 * Allocate in the BSS so we wont require allocation in
2112 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2114 static cpumask_t cpus_with_pcps;
2117 * We don't care about racing with CPU hotplug event
2118 * as offline notification will cause the notified
2119 * cpu to drain that CPU pcps and on_each_cpu_mask
2120 * disables preemption as part of its processing
2122 for_each_online_cpu(cpu) {
2123 struct per_cpu_pageset *pcp;
2125 bool has_pcps = false;
2128 pcp = per_cpu_ptr(zone->pageset, cpu);
2132 for_each_populated_zone(z) {
2133 pcp = per_cpu_ptr(z->pageset, cpu);
2134 if (pcp->pcp.count) {
2142 cpumask_set_cpu(cpu, &cpus_with_pcps);
2144 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2146 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2150 #ifdef CONFIG_HIBERNATION
2152 void mark_free_pages(struct zone *zone)
2154 unsigned long pfn, max_zone_pfn;
2155 unsigned long flags;
2156 unsigned int order, t;
2159 if (zone_is_empty(zone))
2162 spin_lock_irqsave(&zone->lock, flags);
2164 max_zone_pfn = zone_end_pfn(zone);
2165 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2166 if (pfn_valid(pfn)) {
2167 page = pfn_to_page(pfn);
2169 if (page_zone(page) != zone)
2172 if (!swsusp_page_is_forbidden(page))
2173 swsusp_unset_page_free(page);
2176 for_each_migratetype_order(order, t) {
2177 list_for_each_entry(page,
2178 &zone->free_area[order].free_list[t], lru) {
2181 pfn = page_to_pfn(page);
2182 for (i = 0; i < (1UL << order); i++)
2183 swsusp_set_page_free(pfn_to_page(pfn + i));
2186 spin_unlock_irqrestore(&zone->lock, flags);
2188 #endif /* CONFIG_PM */
2191 * Free a 0-order page
2192 * cold == true ? free a cold page : free a hot page
2194 void free_hot_cold_page(struct page *page, bool cold)
2196 struct zone *zone = page_zone(page);
2197 struct per_cpu_pages *pcp;
2198 unsigned long flags;
2199 unsigned long pfn = page_to_pfn(page);
2202 if (!free_pages_prepare(page, 0))
2205 migratetype = get_pfnblock_migratetype(page, pfn);
2206 set_pcppage_migratetype(page, migratetype);
2207 local_irq_save(flags);
2208 __count_vm_event(PGFREE);
2211 * We only track unmovable, reclaimable and movable on pcp lists.
2212 * Free ISOLATE pages back to the allocator because they are being
2213 * offlined but treat RESERVE as movable pages so we can get those
2214 * areas back if necessary. Otherwise, we may have to free
2215 * excessively into the page allocator
2217 if (migratetype >= MIGRATE_PCPTYPES) {
2218 if (unlikely(is_migrate_isolate(migratetype))) {
2219 free_one_page(zone, page, pfn, 0, migratetype);
2222 migratetype = MIGRATE_MOVABLE;
2225 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2227 list_add(&page->lru, &pcp->lists[migratetype]);
2229 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2231 if (pcp->count >= pcp->high) {
2232 unsigned long batch = READ_ONCE(pcp->batch);
2233 free_pcppages_bulk(zone, batch, pcp);
2234 pcp->count -= batch;
2238 local_irq_restore(flags);
2242 * Free a list of 0-order pages
2244 void free_hot_cold_page_list(struct list_head *list, bool cold)
2246 struct page *page, *next;
2248 list_for_each_entry_safe(page, next, list, lru) {
2249 trace_mm_page_free_batched(page, cold);
2250 free_hot_cold_page(page, cold);
2255 * split_page takes a non-compound higher-order page, and splits it into
2256 * n (1<<order) sub-pages: page[0..n]
2257 * Each sub-page must be freed individually.
2259 * Note: this is probably too low level an operation for use in drivers.
2260 * Please consult with lkml before using this in your driver.
2262 void split_page(struct page *page, unsigned int order)
2267 VM_BUG_ON_PAGE(PageCompound(page), page);
2268 VM_BUG_ON_PAGE(!page_count(page), page);
2270 #ifdef CONFIG_KMEMCHECK
2272 * Split shadow pages too, because free(page[0]) would
2273 * otherwise free the whole shadow.
2275 if (kmemcheck_page_is_tracked(page))
2276 split_page(virt_to_page(page[0].shadow), order);
2279 gfp_mask = get_page_owner_gfp(page);
2280 set_page_owner(page, 0, gfp_mask);
2281 for (i = 1; i < (1 << order); i++) {
2282 set_page_refcounted(page + i);
2283 set_page_owner(page + i, 0, gfp_mask);
2286 EXPORT_SYMBOL_GPL(split_page);
2288 int __isolate_free_page(struct page *page, unsigned int order)
2290 unsigned long watermark;
2294 BUG_ON(!PageBuddy(page));
2296 zone = page_zone(page);
2297 mt = get_pageblock_migratetype(page);
2299 if (!is_migrate_isolate(mt)) {
2300 /* Obey watermarks as if the page was being allocated */
2301 watermark = low_wmark_pages(zone) + (1 << order);
2302 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2305 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2308 /* Remove page from free list */
2309 list_del(&page->lru);
2310 zone->free_area[order].nr_free--;
2311 rmv_page_order(page);
2313 set_page_owner(page, order, __GFP_MOVABLE);
2315 /* Set the pageblock if the isolated page is at least a pageblock */
2316 if (order >= pageblock_order - 1) {
2317 struct page *endpage = page + (1 << order) - 1;
2318 for (; page < endpage; page += pageblock_nr_pages) {
2319 int mt = get_pageblock_migratetype(page);
2320 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2321 set_pageblock_migratetype(page,
2327 return 1UL << order;
2331 * Similar to split_page except the page is already free. As this is only
2332 * being used for migration, the migratetype of the block also changes.
2333 * As this is called with interrupts disabled, the caller is responsible
2334 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2337 * Note: this is probably too low level an operation for use in drivers.
2338 * Please consult with lkml before using this in your driver.
2340 int split_free_page(struct page *page)
2345 order = page_order(page);
2347 nr_pages = __isolate_free_page(page, order);
2351 /* Split into individual pages */
2352 set_page_refcounted(page);
2353 split_page(page, order);
2358 * Update NUMA hit/miss statistics
2360 * Must be called with interrupts disabled.
2362 * When __GFP_OTHER_NODE is set assume the node of the preferred
2363 * zone is the local node. This is useful for daemons who allocate
2364 * memory on behalf of other processes.
2366 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2370 int local_nid = numa_node_id();
2371 enum zone_stat_item local_stat = NUMA_LOCAL;
2373 if (unlikely(flags & __GFP_OTHER_NODE)) {
2374 local_stat = NUMA_OTHER;
2375 local_nid = preferred_zone->node;
2378 if (z->node == local_nid) {
2379 __inc_zone_state(z, NUMA_HIT);
2380 __inc_zone_state(z, local_stat);
2382 __inc_zone_state(z, NUMA_MISS);
2383 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2389 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2392 struct page *buffered_rmqueue(struct zone *preferred_zone,
2393 struct zone *zone, unsigned int order,
2394 gfp_t gfp_flags, int alloc_flags, int migratetype)
2396 unsigned long flags;
2398 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2400 if (likely(order == 0)) {
2401 struct per_cpu_pages *pcp;
2402 struct list_head *list;
2404 local_irq_save(flags);
2405 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2406 list = &pcp->lists[migratetype];
2407 if (list_empty(list)) {
2408 pcp->count += rmqueue_bulk(zone, 0,
2411 if (unlikely(list_empty(list)))
2416 page = list_last_entry(list, struct page, lru);
2418 page = list_first_entry(list, struct page, lru);
2420 __dec_zone_state(zone, NR_ALLOC_BATCH);
2421 list_del(&page->lru);
2425 * We most definitely don't want callers attempting to
2426 * allocate greater than order-1 page units with __GFP_NOFAIL.
2428 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2429 spin_lock_irqsave(&zone->lock, flags);
2432 if (alloc_flags & ALLOC_HARDER) {
2433 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2435 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2438 page = __rmqueue(zone, order, migratetype);
2439 spin_unlock(&zone->lock);
2442 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2443 __mod_zone_freepage_state(zone, -(1 << order),
2444 get_pcppage_migratetype(page));
2447 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2448 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2449 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2451 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2452 zone_statistics(preferred_zone, zone, gfp_flags);
2453 local_irq_restore(flags);
2455 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2459 local_irq_restore(flags);
2463 #ifdef CONFIG_FAIL_PAGE_ALLOC
2466 struct fault_attr attr;
2468 bool ignore_gfp_highmem;
2469 bool ignore_gfp_reclaim;
2471 } fail_page_alloc = {
2472 .attr = FAULT_ATTR_INITIALIZER,
2473 .ignore_gfp_reclaim = true,
2474 .ignore_gfp_highmem = true,
2478 static int __init setup_fail_page_alloc(char *str)
2480 return setup_fault_attr(&fail_page_alloc.attr, str);
2482 __setup("fail_page_alloc=", setup_fail_page_alloc);
2484 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2486 if (order < fail_page_alloc.min_order)
2488 if (gfp_mask & __GFP_NOFAIL)
2490 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2492 if (fail_page_alloc.ignore_gfp_reclaim &&
2493 (gfp_mask & __GFP_DIRECT_RECLAIM))
2496 return should_fail(&fail_page_alloc.attr, 1 << order);
2499 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2501 static int __init fail_page_alloc_debugfs(void)
2503 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2506 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2507 &fail_page_alloc.attr);
2509 return PTR_ERR(dir);
2511 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2512 &fail_page_alloc.ignore_gfp_reclaim))
2514 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2515 &fail_page_alloc.ignore_gfp_highmem))
2517 if (!debugfs_create_u32("min-order", mode, dir,
2518 &fail_page_alloc.min_order))
2523 debugfs_remove_recursive(dir);
2528 late_initcall(fail_page_alloc_debugfs);
2530 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2532 #else /* CONFIG_FAIL_PAGE_ALLOC */
2534 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2539 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2542 * Return true if free base pages are above 'mark'. For high-order checks it
2543 * will return true of the order-0 watermark is reached and there is at least
2544 * one free page of a suitable size. Checking now avoids taking the zone lock
2545 * to check in the allocation paths if no pages are free.
2547 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2548 unsigned long mark, int classzone_idx, int alloc_flags,
2553 const int alloc_harder = (alloc_flags & ALLOC_HARDER);
2555 /* free_pages may go negative - that's OK */
2556 free_pages -= (1 << order) - 1;
2558 if (alloc_flags & ALLOC_HIGH)
2562 * If the caller does not have rights to ALLOC_HARDER then subtract
2563 * the high-atomic reserves. This will over-estimate the size of the
2564 * atomic reserve but it avoids a search.
2566 if (likely(!alloc_harder))
2567 free_pages -= z->nr_reserved_highatomic;
2572 /* If allocation can't use CMA areas don't use free CMA pages */
2573 if (!(alloc_flags & ALLOC_CMA))
2574 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2578 * Check watermarks for an order-0 allocation request. If these
2579 * are not met, then a high-order request also cannot go ahead
2580 * even if a suitable page happened to be free.
2582 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2585 /* If this is an order-0 request then the watermark is fine */
2589 /* For a high-order request, check at least one suitable page is free */
2590 for (o = order; o < MAX_ORDER; o++) {
2591 struct free_area *area = &z->free_area[o];
2600 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2601 if (!list_empty(&area->free_list[mt]))
2606 if ((alloc_flags & ALLOC_CMA) &&
2607 !list_empty(&area->free_list[MIGRATE_CMA])) {
2615 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2616 int classzone_idx, int alloc_flags)
2618 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2619 zone_page_state(z, NR_FREE_PAGES));
2622 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2623 unsigned long mark, int classzone_idx)
2625 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2627 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2628 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2630 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2635 static bool zone_local(struct zone *local_zone, struct zone *zone)
2637 return local_zone->node == zone->node;
2640 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2642 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2645 #else /* CONFIG_NUMA */
2646 static bool zone_local(struct zone *local_zone, struct zone *zone)
2651 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2655 #endif /* CONFIG_NUMA */
2657 static void reset_alloc_batches(struct zone *preferred_zone)
2659 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2662 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2663 high_wmark_pages(zone) - low_wmark_pages(zone) -
2664 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2665 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2666 } while (zone++ != preferred_zone);
2670 * get_page_from_freelist goes through the zonelist trying to allocate
2673 static struct page *
2674 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2675 const struct alloc_context *ac)
2677 struct zonelist *zonelist = ac->zonelist;
2679 struct page *page = NULL;
2681 int nr_fair_skipped = 0;
2682 bool zonelist_rescan;
2685 zonelist_rescan = false;
2688 * Scan zonelist, looking for a zone with enough free.
2689 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2691 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2695 if (cpusets_enabled() &&
2696 (alloc_flags & ALLOC_CPUSET) &&
2697 !cpuset_zone_allowed(zone, gfp_mask))
2700 * Distribute pages in proportion to the individual
2701 * zone size to ensure fair page aging. The zone a
2702 * page was allocated in should have no effect on the
2703 * time the page has in memory before being reclaimed.
2705 if (alloc_flags & ALLOC_FAIR) {
2706 if (!zone_local(ac->preferred_zone, zone))
2708 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2714 * When allocating a page cache page for writing, we
2715 * want to get it from a zone that is within its dirty
2716 * limit, such that no single zone holds more than its
2717 * proportional share of globally allowed dirty pages.
2718 * The dirty limits take into account the zone's
2719 * lowmem reserves and high watermark so that kswapd
2720 * should be able to balance it without having to
2721 * write pages from its LRU list.
2723 * This may look like it could increase pressure on
2724 * lower zones by failing allocations in higher zones
2725 * before they are full. But the pages that do spill
2726 * over are limited as the lower zones are protected
2727 * by this very same mechanism. It should not become
2728 * a practical burden to them.
2730 * XXX: For now, allow allocations to potentially
2731 * exceed the per-zone dirty limit in the slowpath
2732 * (spread_dirty_pages unset) before going into reclaim,
2733 * which is important when on a NUMA setup the allowed
2734 * zones are together not big enough to reach the
2735 * global limit. The proper fix for these situations
2736 * will require awareness of zones in the
2737 * dirty-throttling and the flusher threads.
2739 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2742 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2743 if (!zone_watermark_ok(zone, order, mark,
2744 ac->classzone_idx, alloc_flags)) {
2747 /* Checked here to keep the fast path fast */
2748 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2749 if (alloc_flags & ALLOC_NO_WATERMARKS)
2752 if (zone_reclaim_mode == 0 ||
2753 !zone_allows_reclaim(ac->preferred_zone, zone))
2756 ret = zone_reclaim(zone, gfp_mask, order);
2758 case ZONE_RECLAIM_NOSCAN:
2761 case ZONE_RECLAIM_FULL:
2762 /* scanned but unreclaimable */
2765 /* did we reclaim enough */
2766 if (zone_watermark_ok(zone, order, mark,
2767 ac->classzone_idx, alloc_flags))
2775 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2776 gfp_mask, alloc_flags, ac->migratetype);
2778 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2782 * If this is a high-order atomic allocation then check
2783 * if the pageblock should be reserved for the future
2785 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2786 reserve_highatomic_pageblock(page, zone, order);
2793 * The first pass makes sure allocations are spread fairly within the
2794 * local node. However, the local node might have free pages left
2795 * after the fairness batches are exhausted, and remote zones haven't
2796 * even been considered yet. Try once more without fairness, and
2797 * include remote zones now, before entering the slowpath and waking
2798 * kswapd: prefer spilling to a remote zone over swapping locally.
2800 if (alloc_flags & ALLOC_FAIR) {
2801 alloc_flags &= ~ALLOC_FAIR;
2802 if (nr_fair_skipped) {
2803 zonelist_rescan = true;
2804 reset_alloc_batches(ac->preferred_zone);
2806 if (nr_online_nodes > 1)
2807 zonelist_rescan = true;
2810 if (zonelist_rescan)
2817 * Large machines with many possible nodes should not always dump per-node
2818 * meminfo in irq context.
2820 static inline bool should_suppress_show_mem(void)
2825 ret = in_interrupt();
2830 static DEFINE_RATELIMIT_STATE(nopage_rs,
2831 DEFAULT_RATELIMIT_INTERVAL,
2832 DEFAULT_RATELIMIT_BURST);
2834 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
2836 unsigned int filter = SHOW_MEM_FILTER_NODES;
2838 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2839 debug_guardpage_minorder() > 0)
2843 * This documents exceptions given to allocations in certain
2844 * contexts that are allowed to allocate outside current's set
2847 if (!(gfp_mask & __GFP_NOMEMALLOC))
2848 if (test_thread_flag(TIF_MEMDIE) ||
2849 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2850 filter &= ~SHOW_MEM_FILTER_NODES;
2851 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
2852 filter &= ~SHOW_MEM_FILTER_NODES;
2855 struct va_format vaf;
2858 va_start(args, fmt);
2863 pr_warn("%pV", &vaf);
2868 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2869 current->comm, order, gfp_mask, &gfp_mask);
2871 if (!should_suppress_show_mem())
2875 static inline struct page *
2876 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2877 const struct alloc_context *ac, unsigned long *did_some_progress)
2879 struct oom_control oc = {
2880 .zonelist = ac->zonelist,
2881 .nodemask = ac->nodemask,
2882 .gfp_mask = gfp_mask,
2887 *did_some_progress = 0;
2890 * Acquire the oom lock. If that fails, somebody else is
2891 * making progress for us.
2893 if (!mutex_trylock(&oom_lock)) {
2894 *did_some_progress = 1;
2895 schedule_timeout_uninterruptible(1);
2900 * Go through the zonelist yet one more time, keep very high watermark
2901 * here, this is only to catch a parallel oom killing, we must fail if
2902 * we're still under heavy pressure.
2904 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2905 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2909 if (!(gfp_mask & __GFP_NOFAIL)) {
2910 /* Coredumps can quickly deplete all memory reserves */
2911 if (current->flags & PF_DUMPCORE)
2913 /* The OOM killer will not help higher order allocs */
2914 if (order > PAGE_ALLOC_COSTLY_ORDER)
2916 /* The OOM killer does not needlessly kill tasks for lowmem */
2917 if (ac->high_zoneidx < ZONE_NORMAL)
2919 if (pm_suspended_storage())
2922 * XXX: GFP_NOFS allocations should rather fail than rely on
2923 * other request to make a forward progress.
2924 * We are in an unfortunate situation where out_of_memory cannot
2925 * do much for this context but let's try it to at least get
2926 * access to memory reserved if the current task is killed (see
2927 * out_of_memory). Once filesystems are ready to handle allocation
2928 * failures more gracefully we should just bail out here.
2931 /* The OOM killer may not free memory on a specific node */
2932 if (gfp_mask & __GFP_THISNODE)
2935 /* Exhausted what can be done so it's blamo time */
2936 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
2937 *did_some_progress = 1;
2939 if (gfp_mask & __GFP_NOFAIL) {
2940 page = get_page_from_freelist(gfp_mask, order,
2941 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
2943 * fallback to ignore cpuset restriction if our nodes
2947 page = get_page_from_freelist(gfp_mask, order,
2948 ALLOC_NO_WATERMARKS, ac);
2952 mutex_unlock(&oom_lock);
2956 #ifdef CONFIG_COMPACTION
2957 /* Try memory compaction for high-order allocations before reclaim */
2958 static struct page *
2959 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2960 int alloc_flags, const struct alloc_context *ac,
2961 enum migrate_mode mode, int *contended_compaction,
2962 bool *deferred_compaction)
2964 unsigned long compact_result;
2970 current->flags |= PF_MEMALLOC;
2971 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2972 mode, contended_compaction);
2973 current->flags &= ~PF_MEMALLOC;
2975 switch (compact_result) {
2976 case COMPACT_DEFERRED:
2977 *deferred_compaction = true;
2979 case COMPACT_SKIPPED:
2986 * At least in one zone compaction wasn't deferred or skipped, so let's
2987 * count a compaction stall
2989 count_vm_event(COMPACTSTALL);
2991 page = get_page_from_freelist(gfp_mask, order,
2992 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2995 struct zone *zone = page_zone(page);
2997 zone->compact_blockskip_flush = false;
2998 compaction_defer_reset(zone, order, true);
2999 count_vm_event(COMPACTSUCCESS);
3004 * It's bad if compaction run occurs and fails. The most likely reason
3005 * is that pages exist, but not enough to satisfy watermarks.
3007 count_vm_event(COMPACTFAIL);
3014 static inline struct page *
3015 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3016 int alloc_flags, const struct alloc_context *ac,
3017 enum migrate_mode mode, int *contended_compaction,
3018 bool *deferred_compaction)
3022 #endif /* CONFIG_COMPACTION */
3024 /* Perform direct synchronous page reclaim */
3026 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3027 const struct alloc_context *ac)
3029 struct reclaim_state reclaim_state;
3034 /* We now go into synchronous reclaim */
3035 cpuset_memory_pressure_bump();
3036 current->flags |= PF_MEMALLOC;
3037 lockdep_set_current_reclaim_state(gfp_mask);
3038 reclaim_state.reclaimed_slab = 0;
3039 current->reclaim_state = &reclaim_state;
3041 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3044 current->reclaim_state = NULL;
3045 lockdep_clear_current_reclaim_state();
3046 current->flags &= ~PF_MEMALLOC;
3053 /* The really slow allocator path where we enter direct reclaim */
3054 static inline struct page *
3055 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3056 int alloc_flags, const struct alloc_context *ac,
3057 unsigned long *did_some_progress)
3059 struct page *page = NULL;
3060 bool drained = false;
3062 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3063 if (unlikely(!(*did_some_progress)))
3067 page = get_page_from_freelist(gfp_mask, order,
3068 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3071 * If an allocation failed after direct reclaim, it could be because
3072 * pages are pinned on the per-cpu lists or in high alloc reserves.
3073 * Shrink them them and try again
3075 if (!page && !drained) {
3076 unreserve_highatomic_pageblock(ac);
3077 drain_all_pages(NULL);
3085 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3090 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3091 ac->high_zoneidx, ac->nodemask)
3092 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
3096 gfp_to_alloc_flags(gfp_t gfp_mask)
3098 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3100 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3101 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3104 * The caller may dip into page reserves a bit more if the caller
3105 * cannot run direct reclaim, or if the caller has realtime scheduling
3106 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3107 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3109 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3111 if (gfp_mask & __GFP_ATOMIC) {
3113 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3114 * if it can't schedule.
3116 if (!(gfp_mask & __GFP_NOMEMALLOC))
3117 alloc_flags |= ALLOC_HARDER;
3119 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3120 * comment for __cpuset_node_allowed().
3122 alloc_flags &= ~ALLOC_CPUSET;
3123 } else if (unlikely(rt_task(current)) && !in_interrupt())
3124 alloc_flags |= ALLOC_HARDER;
3126 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3127 if (gfp_mask & __GFP_MEMALLOC)
3128 alloc_flags |= ALLOC_NO_WATERMARKS;
3129 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3130 alloc_flags |= ALLOC_NO_WATERMARKS;
3131 else if (!in_interrupt() &&
3132 ((current->flags & PF_MEMALLOC) ||
3133 unlikely(test_thread_flag(TIF_MEMDIE))))
3134 alloc_flags |= ALLOC_NO_WATERMARKS;
3137 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3138 alloc_flags |= ALLOC_CMA;
3143 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3145 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3148 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3150 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3153 static inline struct page *
3154 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3155 struct alloc_context *ac)
3157 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3158 struct page *page = NULL;
3160 unsigned long pages_reclaimed = 0;
3161 unsigned long did_some_progress;
3162 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3163 bool deferred_compaction = false;
3164 int contended_compaction = COMPACT_CONTENDED_NONE;
3167 * In the slowpath, we sanity check order to avoid ever trying to
3168 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3169 * be using allocators in order of preference for an area that is
3172 if (order >= MAX_ORDER) {
3173 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3178 * We also sanity check to catch abuse of atomic reserves being used by
3179 * callers that are not in atomic context.
3181 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3182 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3183 gfp_mask &= ~__GFP_ATOMIC;
3186 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3187 wake_all_kswapds(order, ac);
3190 * OK, we're below the kswapd watermark and have kicked background
3191 * reclaim. Now things get more complex, so set up alloc_flags according
3192 * to how we want to proceed.
3194 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3196 /* This is the last chance, in general, before the goto nopage. */
3197 page = get_page_from_freelist(gfp_mask, order,
3198 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3202 /* Allocate without watermarks if the context allows */
3203 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3205 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3206 * the allocation is high priority and these type of
3207 * allocations are system rather than user orientated
3209 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3210 page = get_page_from_freelist(gfp_mask, order,
3211 ALLOC_NO_WATERMARKS, ac);
3216 /* Caller is not willing to reclaim, we can't balance anything */
3217 if (!can_direct_reclaim) {
3219 * All existing users of the __GFP_NOFAIL are blockable, so warn
3220 * of any new users that actually allow this type of allocation
3223 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3227 /* Avoid recursion of direct reclaim */
3228 if (current->flags & PF_MEMALLOC) {
3230 * __GFP_NOFAIL request from this context is rather bizarre
3231 * because we cannot reclaim anything and only can loop waiting
3232 * for somebody to do a work for us.
3234 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3241 /* Avoid allocations with no watermarks from looping endlessly */
3242 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3246 * Try direct compaction. The first pass is asynchronous. Subsequent
3247 * attempts after direct reclaim are synchronous
3249 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3251 &contended_compaction,
3252 &deferred_compaction);
3256 /* Checks for THP-specific high-order allocations */
3257 if (is_thp_gfp_mask(gfp_mask)) {
3259 * If compaction is deferred for high-order allocations, it is
3260 * because sync compaction recently failed. If this is the case
3261 * and the caller requested a THP allocation, we do not want
3262 * to heavily disrupt the system, so we fail the allocation
3263 * instead of entering direct reclaim.
3265 if (deferred_compaction)
3269 * In all zones where compaction was attempted (and not
3270 * deferred or skipped), lock contention has been detected.
3271 * For THP allocation we do not want to disrupt the others
3272 * so we fallback to base pages instead.
3274 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3278 * If compaction was aborted due to need_resched(), we do not
3279 * want to further increase allocation latency, unless it is
3280 * khugepaged trying to collapse.
3282 if (contended_compaction == COMPACT_CONTENDED_SCHED
3283 && !(current->flags & PF_KTHREAD))
3288 * It can become very expensive to allocate transparent hugepages at
3289 * fault, so use asynchronous memory compaction for THP unless it is
3290 * khugepaged trying to collapse.
3292 if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
3293 migration_mode = MIGRATE_SYNC_LIGHT;
3295 /* Try direct reclaim and then allocating */
3296 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3297 &did_some_progress);
3301 /* Do not loop if specifically requested */
3302 if (gfp_mask & __GFP_NORETRY)
3305 /* Keep reclaiming pages as long as there is reasonable progress */
3306 pages_reclaimed += did_some_progress;
3307 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3308 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3309 /* Wait for some write requests to complete then retry */
3310 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
3314 /* Reclaim has failed us, start killing things */
3315 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3319 /* Retry as long as the OOM killer is making progress */
3320 if (did_some_progress)
3325 * High-order allocations do not necessarily loop after
3326 * direct reclaim and reclaim/compaction depends on compaction
3327 * being called after reclaim so call directly if necessary
3329 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3331 &contended_compaction,
3332 &deferred_compaction);
3336 warn_alloc_failed(gfp_mask, order, NULL);
3342 * This is the 'heart' of the zoned buddy allocator.
3345 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3346 struct zonelist *zonelist, nodemask_t *nodemask)
3348 struct zoneref *preferred_zoneref;
3349 struct page *page = NULL;
3350 unsigned int cpuset_mems_cookie;
3351 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR;
3352 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
3353 struct alloc_context ac = {
3354 .high_zoneidx = gfp_zone(gfp_mask),
3355 .zonelist = zonelist,
3356 .nodemask = nodemask,
3357 .migratetype = gfpflags_to_migratetype(gfp_mask),
3360 if (cpusets_enabled()) {
3361 alloc_flags |= ALLOC_CPUSET;
3363 ac.nodemask = &cpuset_current_mems_allowed;
3366 gfp_mask &= gfp_allowed_mask;
3368 lockdep_trace_alloc(gfp_mask);
3370 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3372 if (should_fail_alloc_page(gfp_mask, order))
3376 * Check the zones suitable for the gfp_mask contain at least one
3377 * valid zone. It's possible to have an empty zonelist as a result
3378 * of __GFP_THISNODE and a memoryless node
3380 if (unlikely(!zonelist->_zonerefs->zone))
3383 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3384 alloc_flags |= ALLOC_CMA;
3387 cpuset_mems_cookie = read_mems_allowed_begin();
3389 /* Dirty zone balancing only done in the fast path */
3390 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3392 /* The preferred zone is used for statistics later */
3393 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
3394 ac.nodemask, &ac.preferred_zone);
3395 if (!ac.preferred_zone)
3397 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
3399 /* First allocation attempt */
3400 alloc_mask = gfp_mask|__GFP_HARDWALL;
3401 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3402 if (unlikely(!page)) {
3404 * Runtime PM, block IO and its error handling path
3405 * can deadlock because I/O on the device might not
3408 alloc_mask = memalloc_noio_flags(gfp_mask);
3409 ac.spread_dirty_pages = false;
3411 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3414 if (kmemcheck_enabled && page)
3415 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3417 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3421 * When updating a task's mems_allowed, it is possible to race with
3422 * parallel threads in such a way that an allocation can fail while
3423 * the mask is being updated. If a page allocation is about to fail,
3424 * check if the cpuset changed during allocation and if so, retry.
3426 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
3431 EXPORT_SYMBOL(__alloc_pages_nodemask);
3434 * Common helper functions.
3436 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3441 * __get_free_pages() returns a 32-bit address, which cannot represent
3444 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3446 page = alloc_pages(gfp_mask, order);
3449 return (unsigned long) page_address(page);
3451 EXPORT_SYMBOL(__get_free_pages);
3453 unsigned long get_zeroed_page(gfp_t gfp_mask)
3455 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3457 EXPORT_SYMBOL(get_zeroed_page);
3459 void __free_pages(struct page *page, unsigned int order)
3461 if (put_page_testzero(page)) {
3463 free_hot_cold_page(page, false);
3465 __free_pages_ok(page, order);
3469 EXPORT_SYMBOL(__free_pages);
3471 void free_pages(unsigned long addr, unsigned int order)
3474 VM_BUG_ON(!virt_addr_valid((void *)addr));
3475 __free_pages(virt_to_page((void *)addr), order);
3479 EXPORT_SYMBOL(free_pages);
3483 * An arbitrary-length arbitrary-offset area of memory which resides
3484 * within a 0 or higher order page. Multiple fragments within that page
3485 * are individually refcounted, in the page's reference counter.
3487 * The page_frag functions below provide a simple allocation framework for
3488 * page fragments. This is used by the network stack and network device
3489 * drivers to provide a backing region of memory for use as either an
3490 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3492 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3495 struct page *page = NULL;
3496 gfp_t gfp = gfp_mask;
3498 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3499 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3501 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3502 PAGE_FRAG_CACHE_MAX_ORDER);
3503 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3505 if (unlikely(!page))
3506 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3508 nc->va = page ? page_address(page) : NULL;
3513 void *__alloc_page_frag(struct page_frag_cache *nc,
3514 unsigned int fragsz, gfp_t gfp_mask)
3516 unsigned int size = PAGE_SIZE;
3520 if (unlikely(!nc->va)) {
3522 page = __page_frag_refill(nc, gfp_mask);
3526 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3527 /* if size can vary use size else just use PAGE_SIZE */
3530 /* Even if we own the page, we do not use atomic_set().
3531 * This would break get_page_unless_zero() users.
3533 page_ref_add(page, size - 1);
3535 /* reset page count bias and offset to start of new frag */
3536 nc->pfmemalloc = page_is_pfmemalloc(page);
3537 nc->pagecnt_bias = size;
3541 offset = nc->offset - fragsz;
3542 if (unlikely(offset < 0)) {
3543 page = virt_to_page(nc->va);
3545 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3548 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3549 /* if size can vary use size else just use PAGE_SIZE */
3552 /* OK, page count is 0, we can safely set it */
3553 set_page_count(page, size);
3555 /* reset page count bias and offset to start of new frag */
3556 nc->pagecnt_bias = size;
3557 offset = size - fragsz;
3561 nc->offset = offset;
3563 return nc->va + offset;
3565 EXPORT_SYMBOL(__alloc_page_frag);
3568 * Frees a page fragment allocated out of either a compound or order 0 page.
3570 void __free_page_frag(void *addr)
3572 struct page *page = virt_to_head_page(addr);
3574 if (unlikely(put_page_testzero(page)))
3575 __free_pages_ok(page, compound_order(page));
3577 EXPORT_SYMBOL(__free_page_frag);
3580 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3581 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3582 * equivalent to alloc_pages.
3584 * It should be used when the caller would like to use kmalloc, but since the
3585 * allocation is large, it has to fall back to the page allocator.
3587 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3591 page = alloc_pages(gfp_mask, order);
3592 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3593 __free_pages(page, order);
3599 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3603 page = alloc_pages_node(nid, gfp_mask, order);
3604 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3605 __free_pages(page, order);
3612 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3615 void __free_kmem_pages(struct page *page, unsigned int order)
3617 memcg_kmem_uncharge(page, order);
3618 __free_pages(page, order);
3621 void free_kmem_pages(unsigned long addr, unsigned int order)
3624 VM_BUG_ON(!virt_addr_valid((void *)addr));
3625 __free_kmem_pages(virt_to_page((void *)addr), order);
3629 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3633 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3634 unsigned long used = addr + PAGE_ALIGN(size);
3636 split_page(virt_to_page((void *)addr), order);
3637 while (used < alloc_end) {
3642 return (void *)addr;
3646 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3647 * @size: the number of bytes to allocate
3648 * @gfp_mask: GFP flags for the allocation
3650 * This function is similar to alloc_pages(), except that it allocates the
3651 * minimum number of pages to satisfy the request. alloc_pages() can only
3652 * allocate memory in power-of-two pages.
3654 * This function is also limited by MAX_ORDER.
3656 * Memory allocated by this function must be released by free_pages_exact().
3658 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3660 unsigned int order = get_order(size);
3663 addr = __get_free_pages(gfp_mask, order);
3664 return make_alloc_exact(addr, order, size);
3666 EXPORT_SYMBOL(alloc_pages_exact);
3669 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3671 * @nid: the preferred node ID where memory should be allocated
3672 * @size: the number of bytes to allocate
3673 * @gfp_mask: GFP flags for the allocation
3675 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3678 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3680 unsigned int order = get_order(size);
3681 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3684 return make_alloc_exact((unsigned long)page_address(p), order, size);
3688 * free_pages_exact - release memory allocated via alloc_pages_exact()
3689 * @virt: the value returned by alloc_pages_exact.
3690 * @size: size of allocation, same value as passed to alloc_pages_exact().
3692 * Release the memory allocated by a previous call to alloc_pages_exact.
3694 void free_pages_exact(void *virt, size_t size)
3696 unsigned long addr = (unsigned long)virt;
3697 unsigned long end = addr + PAGE_ALIGN(size);
3699 while (addr < end) {
3704 EXPORT_SYMBOL(free_pages_exact);
3707 * nr_free_zone_pages - count number of pages beyond high watermark
3708 * @offset: The zone index of the highest zone
3710 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3711 * high watermark within all zones at or below a given zone index. For each
3712 * zone, the number of pages is calculated as:
3713 * managed_pages - high_pages
3715 static unsigned long nr_free_zone_pages(int offset)
3720 /* Just pick one node, since fallback list is circular */
3721 unsigned long sum = 0;
3723 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3725 for_each_zone_zonelist(zone, z, zonelist, offset) {
3726 unsigned long size = zone->managed_pages;
3727 unsigned long high = high_wmark_pages(zone);
3736 * nr_free_buffer_pages - count number of pages beyond high watermark
3738 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3739 * watermark within ZONE_DMA and ZONE_NORMAL.
3741 unsigned long nr_free_buffer_pages(void)
3743 return nr_free_zone_pages(gfp_zone(GFP_USER));
3745 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3748 * nr_free_pagecache_pages - count number of pages beyond high watermark
3750 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3751 * high watermark within all zones.
3753 unsigned long nr_free_pagecache_pages(void)
3755 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3758 static inline void show_node(struct zone *zone)
3760 if (IS_ENABLED(CONFIG_NUMA))
3761 printk("Node %d ", zone_to_nid(zone));
3764 long si_mem_available(void)
3767 unsigned long pagecache;
3768 unsigned long wmark_low = 0;
3769 unsigned long pages[NR_LRU_LISTS];
3773 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
3774 pages[lru] = global_page_state(NR_LRU_BASE + lru);
3777 wmark_low += zone->watermark[WMARK_LOW];
3780 * Estimate the amount of memory available for userspace allocations,
3781 * without causing swapping.
3783 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
3786 * Not all the page cache can be freed, otherwise the system will
3787 * start swapping. Assume at least half of the page cache, or the
3788 * low watermark worth of cache, needs to stay.
3790 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
3791 pagecache -= min(pagecache / 2, wmark_low);
3792 available += pagecache;
3795 * Part of the reclaimable slab consists of items that are in use,
3796 * and cannot be freed. Cap this estimate at the low watermark.
3798 available += global_page_state(NR_SLAB_RECLAIMABLE) -
3799 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
3805 EXPORT_SYMBOL_GPL(si_mem_available);
3807 void si_meminfo(struct sysinfo *val)
3809 val->totalram = totalram_pages;
3810 val->sharedram = global_page_state(NR_SHMEM);
3811 val->freeram = global_page_state(NR_FREE_PAGES);
3812 val->bufferram = nr_blockdev_pages();
3813 val->totalhigh = totalhigh_pages;
3814 val->freehigh = nr_free_highpages();
3815 val->mem_unit = PAGE_SIZE;
3818 EXPORT_SYMBOL(si_meminfo);
3821 void si_meminfo_node(struct sysinfo *val, int nid)
3823 int zone_type; /* needs to be signed */
3824 unsigned long managed_pages = 0;
3825 unsigned long managed_highpages = 0;
3826 unsigned long free_highpages = 0;
3827 pg_data_t *pgdat = NODE_DATA(nid);
3829 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3830 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3831 val->totalram = managed_pages;
3832 val->sharedram = node_page_state(nid, NR_SHMEM);
3833 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3834 #ifdef CONFIG_HIGHMEM
3835 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3836 struct zone *zone = &pgdat->node_zones[zone_type];
3838 if (is_highmem(zone)) {
3839 managed_highpages += zone->managed_pages;
3840 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
3843 val->totalhigh = managed_highpages;
3844 val->freehigh = free_highpages;
3846 val->totalhigh = managed_highpages;
3847 val->freehigh = free_highpages;
3849 val->mem_unit = PAGE_SIZE;
3854 * Determine whether the node should be displayed or not, depending on whether
3855 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3857 bool skip_free_areas_node(unsigned int flags, int nid)
3860 unsigned int cpuset_mems_cookie;
3862 if (!(flags & SHOW_MEM_FILTER_NODES))
3866 cpuset_mems_cookie = read_mems_allowed_begin();
3867 ret = !node_isset(nid, cpuset_current_mems_allowed);
3868 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3873 #define K(x) ((x) << (PAGE_SHIFT-10))
3875 static void show_migration_types(unsigned char type)
3877 static const char types[MIGRATE_TYPES] = {
3878 [MIGRATE_UNMOVABLE] = 'U',
3879 [MIGRATE_MOVABLE] = 'M',
3880 [MIGRATE_RECLAIMABLE] = 'E',
3881 [MIGRATE_HIGHATOMIC] = 'H',
3883 [MIGRATE_CMA] = 'C',
3885 #ifdef CONFIG_MEMORY_ISOLATION
3886 [MIGRATE_ISOLATE] = 'I',
3889 char tmp[MIGRATE_TYPES + 1];
3893 for (i = 0; i < MIGRATE_TYPES; i++) {
3894 if (type & (1 << i))
3899 printk("(%s) ", tmp);
3903 * Show free area list (used inside shift_scroll-lock stuff)
3904 * We also calculate the percentage fragmentation. We do this by counting the
3905 * memory on each free list with the exception of the first item on the list.
3908 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3911 void show_free_areas(unsigned int filter)
3913 unsigned long free_pcp = 0;
3917 for_each_populated_zone(zone) {
3918 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3921 for_each_online_cpu(cpu)
3922 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3925 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3926 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3927 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3928 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3929 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3930 " free:%lu free_pcp:%lu free_cma:%lu\n",
3931 global_page_state(NR_ACTIVE_ANON),
3932 global_page_state(NR_INACTIVE_ANON),
3933 global_page_state(NR_ISOLATED_ANON),
3934 global_page_state(NR_ACTIVE_FILE),
3935 global_page_state(NR_INACTIVE_FILE),
3936 global_page_state(NR_ISOLATED_FILE),
3937 global_page_state(NR_UNEVICTABLE),
3938 global_page_state(NR_FILE_DIRTY),
3939 global_page_state(NR_WRITEBACK),
3940 global_page_state(NR_UNSTABLE_NFS),
3941 global_page_state(NR_SLAB_RECLAIMABLE),
3942 global_page_state(NR_SLAB_UNRECLAIMABLE),
3943 global_page_state(NR_FILE_MAPPED),
3944 global_page_state(NR_SHMEM),
3945 global_page_state(NR_PAGETABLE),
3946 global_page_state(NR_BOUNCE),
3947 global_page_state(NR_FREE_PAGES),
3949 global_page_state(NR_FREE_CMA_PAGES));
3951 for_each_populated_zone(zone) {
3954 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3958 for_each_online_cpu(cpu)
3959 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3967 " active_anon:%lukB"
3968 " inactive_anon:%lukB"
3969 " active_file:%lukB"
3970 " inactive_file:%lukB"
3971 " unevictable:%lukB"
3972 " isolated(anon):%lukB"
3973 " isolated(file):%lukB"
3981 " slab_reclaimable:%lukB"
3982 " slab_unreclaimable:%lukB"
3983 " kernel_stack:%lukB"
3990 " writeback_tmp:%lukB"
3991 " pages_scanned:%lu"
3992 " all_unreclaimable? %s"
3995 K(zone_page_state(zone, NR_FREE_PAGES)),
3996 K(min_wmark_pages(zone)),
3997 K(low_wmark_pages(zone)),
3998 K(high_wmark_pages(zone)),
3999 K(zone_page_state(zone, NR_ACTIVE_ANON)),
4000 K(zone_page_state(zone, NR_INACTIVE_ANON)),
4001 K(zone_page_state(zone, NR_ACTIVE_FILE)),
4002 K(zone_page_state(zone, NR_INACTIVE_FILE)),
4003 K(zone_page_state(zone, NR_UNEVICTABLE)),
4004 K(zone_page_state(zone, NR_ISOLATED_ANON)),
4005 K(zone_page_state(zone, NR_ISOLATED_FILE)),
4006 K(zone->present_pages),
4007 K(zone->managed_pages),
4008 K(zone_page_state(zone, NR_MLOCK)),
4009 K(zone_page_state(zone, NR_FILE_DIRTY)),
4010 K(zone_page_state(zone, NR_WRITEBACK)),
4011 K(zone_page_state(zone, NR_FILE_MAPPED)),
4012 K(zone_page_state(zone, NR_SHMEM)),
4013 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4014 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4015 zone_page_state(zone, NR_KERNEL_STACK) *
4017 K(zone_page_state(zone, NR_PAGETABLE)),
4018 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
4019 K(zone_page_state(zone, NR_BOUNCE)),
4021 K(this_cpu_read(zone->pageset->pcp.count)),
4022 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
4023 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
4024 K(zone_page_state(zone, NR_PAGES_SCANNED)),
4025 (!zone_reclaimable(zone) ? "yes" : "no")
4027 printk("lowmem_reserve[]:");
4028 for (i = 0; i < MAX_NR_ZONES; i++)
4029 printk(" %ld", zone->lowmem_reserve[i]);
4033 for_each_populated_zone(zone) {
4035 unsigned long nr[MAX_ORDER], flags, total = 0;
4036 unsigned char types[MAX_ORDER];
4038 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4041 printk("%s: ", zone->name);
4043 spin_lock_irqsave(&zone->lock, flags);
4044 for (order = 0; order < MAX_ORDER; order++) {
4045 struct free_area *area = &zone->free_area[order];
4048 nr[order] = area->nr_free;
4049 total += nr[order] << order;
4052 for (type = 0; type < MIGRATE_TYPES; type++) {
4053 if (!list_empty(&area->free_list[type]))
4054 types[order] |= 1 << type;
4057 spin_unlock_irqrestore(&zone->lock, flags);
4058 for (order = 0; order < MAX_ORDER; order++) {
4059 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4061 show_migration_types(types[order]);
4063 printk("= %lukB\n", K(total));
4066 hugetlb_show_meminfo();
4068 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4070 show_swap_cache_info();
4073 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4075 zoneref->zone = zone;
4076 zoneref->zone_idx = zone_idx(zone);
4080 * Builds allocation fallback zone lists.
4082 * Add all populated zones of a node to the zonelist.
4084 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4088 enum zone_type zone_type = MAX_NR_ZONES;
4092 zone = pgdat->node_zones + zone_type;
4093 if (populated_zone(zone)) {
4094 zoneref_set_zone(zone,
4095 &zonelist->_zonerefs[nr_zones++]);
4096 check_highest_zone(zone_type);
4098 } while (zone_type);
4106 * 0 = automatic detection of better ordering.
4107 * 1 = order by ([node] distance, -zonetype)
4108 * 2 = order by (-zonetype, [node] distance)
4110 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4111 * the same zonelist. So only NUMA can configure this param.
4113 #define ZONELIST_ORDER_DEFAULT 0
4114 #define ZONELIST_ORDER_NODE 1
4115 #define ZONELIST_ORDER_ZONE 2
4117 /* zonelist order in the kernel.
4118 * set_zonelist_order() will set this to NODE or ZONE.
4120 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4121 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4125 /* The value user specified ....changed by config */
4126 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4127 /* string for sysctl */
4128 #define NUMA_ZONELIST_ORDER_LEN 16
4129 char numa_zonelist_order[16] = "default";
4132 * interface for configure zonelist ordering.
4133 * command line option "numa_zonelist_order"
4134 * = "[dD]efault - default, automatic configuration.
4135 * = "[nN]ode - order by node locality, then by zone within node
4136 * = "[zZ]one - order by zone, then by locality within zone
4139 static int __parse_numa_zonelist_order(char *s)
4141 if (*s == 'd' || *s == 'D') {
4142 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4143 } else if (*s == 'n' || *s == 'N') {
4144 user_zonelist_order = ZONELIST_ORDER_NODE;
4145 } else if (*s == 'z' || *s == 'Z') {
4146 user_zonelist_order = ZONELIST_ORDER_ZONE;
4148 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4154 static __init int setup_numa_zonelist_order(char *s)
4161 ret = __parse_numa_zonelist_order(s);
4163 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4167 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4170 * sysctl handler for numa_zonelist_order
4172 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4173 void __user *buffer, size_t *length,
4176 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4178 static DEFINE_MUTEX(zl_order_mutex);
4180 mutex_lock(&zl_order_mutex);
4182 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4186 strcpy(saved_string, (char *)table->data);
4188 ret = proc_dostring(table, write, buffer, length, ppos);
4192 int oldval = user_zonelist_order;
4194 ret = __parse_numa_zonelist_order((char *)table->data);
4197 * bogus value. restore saved string
4199 strncpy((char *)table->data, saved_string,
4200 NUMA_ZONELIST_ORDER_LEN);
4201 user_zonelist_order = oldval;
4202 } else if (oldval != user_zonelist_order) {
4203 mutex_lock(&zonelists_mutex);
4204 build_all_zonelists(NULL, NULL);
4205 mutex_unlock(&zonelists_mutex);
4209 mutex_unlock(&zl_order_mutex);
4214 #define MAX_NODE_LOAD (nr_online_nodes)
4215 static int node_load[MAX_NUMNODES];
4218 * find_next_best_node - find the next node that should appear in a given node's fallback list
4219 * @node: node whose fallback list we're appending
4220 * @used_node_mask: nodemask_t of already used nodes
4222 * We use a number of factors to determine which is the next node that should
4223 * appear on a given node's fallback list. The node should not have appeared
4224 * already in @node's fallback list, and it should be the next closest node
4225 * according to the distance array (which contains arbitrary distance values
4226 * from each node to each node in the system), and should also prefer nodes
4227 * with no CPUs, since presumably they'll have very little allocation pressure
4228 * on them otherwise.
4229 * It returns -1 if no node is found.
4231 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4234 int min_val = INT_MAX;
4235 int best_node = NUMA_NO_NODE;
4236 const struct cpumask *tmp = cpumask_of_node(0);
4238 /* Use the local node if we haven't already */
4239 if (!node_isset(node, *used_node_mask)) {
4240 node_set(node, *used_node_mask);
4244 for_each_node_state(n, N_MEMORY) {
4246 /* Don't want a node to appear more than once */
4247 if (node_isset(n, *used_node_mask))
4250 /* Use the distance array to find the distance */
4251 val = node_distance(node, n);
4253 /* Penalize nodes under us ("prefer the next node") */
4256 /* Give preference to headless and unused nodes */
4257 tmp = cpumask_of_node(n);
4258 if (!cpumask_empty(tmp))
4259 val += PENALTY_FOR_NODE_WITH_CPUS;
4261 /* Slight preference for less loaded node */
4262 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4263 val += node_load[n];
4265 if (val < min_val) {
4272 node_set(best_node, *used_node_mask);
4279 * Build zonelists ordered by node and zones within node.
4280 * This results in maximum locality--normal zone overflows into local
4281 * DMA zone, if any--but risks exhausting DMA zone.
4283 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4286 struct zonelist *zonelist;
4288 zonelist = &pgdat->node_zonelists[0];
4289 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4291 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4292 zonelist->_zonerefs[j].zone = NULL;
4293 zonelist->_zonerefs[j].zone_idx = 0;
4297 * Build gfp_thisnode zonelists
4299 static void build_thisnode_zonelists(pg_data_t *pgdat)
4302 struct zonelist *zonelist;
4304 zonelist = &pgdat->node_zonelists[1];
4305 j = build_zonelists_node(pgdat, zonelist, 0);
4306 zonelist->_zonerefs[j].zone = NULL;
4307 zonelist->_zonerefs[j].zone_idx = 0;
4311 * Build zonelists ordered by zone and nodes within zones.
4312 * This results in conserving DMA zone[s] until all Normal memory is
4313 * exhausted, but results in overflowing to remote node while memory
4314 * may still exist in local DMA zone.
4316 static int node_order[MAX_NUMNODES];
4318 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4321 int zone_type; /* needs to be signed */
4323 struct zonelist *zonelist;
4325 zonelist = &pgdat->node_zonelists[0];
4327 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4328 for (j = 0; j < nr_nodes; j++) {
4329 node = node_order[j];
4330 z = &NODE_DATA(node)->node_zones[zone_type];
4331 if (populated_zone(z)) {
4333 &zonelist->_zonerefs[pos++]);
4334 check_highest_zone(zone_type);
4338 zonelist->_zonerefs[pos].zone = NULL;
4339 zonelist->_zonerefs[pos].zone_idx = 0;
4342 #if defined(CONFIG_64BIT)
4344 * Devices that require DMA32/DMA are relatively rare and do not justify a
4345 * penalty to every machine in case the specialised case applies. Default
4346 * to Node-ordering on 64-bit NUMA machines
4348 static int default_zonelist_order(void)
4350 return ZONELIST_ORDER_NODE;
4354 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4355 * by the kernel. If processes running on node 0 deplete the low memory zone
4356 * then reclaim will occur more frequency increasing stalls and potentially
4357 * be easier to OOM if a large percentage of the zone is under writeback or
4358 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4359 * Hence, default to zone ordering on 32-bit.
4361 static int default_zonelist_order(void)
4363 return ZONELIST_ORDER_ZONE;
4365 #endif /* CONFIG_64BIT */
4367 static void set_zonelist_order(void)
4369 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4370 current_zonelist_order = default_zonelist_order();
4372 current_zonelist_order = user_zonelist_order;
4375 static void build_zonelists(pg_data_t *pgdat)
4378 nodemask_t used_mask;
4379 int local_node, prev_node;
4380 struct zonelist *zonelist;
4381 unsigned int order = current_zonelist_order;
4383 /* initialize zonelists */
4384 for (i = 0; i < MAX_ZONELISTS; i++) {
4385 zonelist = pgdat->node_zonelists + i;
4386 zonelist->_zonerefs[0].zone = NULL;
4387 zonelist->_zonerefs[0].zone_idx = 0;
4390 /* NUMA-aware ordering of nodes */
4391 local_node = pgdat->node_id;
4392 load = nr_online_nodes;
4393 prev_node = local_node;
4394 nodes_clear(used_mask);
4396 memset(node_order, 0, sizeof(node_order));
4399 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4401 * We don't want to pressure a particular node.
4402 * So adding penalty to the first node in same
4403 * distance group to make it round-robin.
4405 if (node_distance(local_node, node) !=
4406 node_distance(local_node, prev_node))
4407 node_load[node] = load;
4411 if (order == ZONELIST_ORDER_NODE)
4412 build_zonelists_in_node_order(pgdat, node);
4414 node_order[i++] = node; /* remember order */
4417 if (order == ZONELIST_ORDER_ZONE) {
4418 /* calculate node order -- i.e., DMA last! */
4419 build_zonelists_in_zone_order(pgdat, i);
4422 build_thisnode_zonelists(pgdat);
4425 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4427 * Return node id of node used for "local" allocations.
4428 * I.e., first node id of first zone in arg node's generic zonelist.
4429 * Used for initializing percpu 'numa_mem', which is used primarily
4430 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4432 int local_memory_node(int node)
4436 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4437 gfp_zone(GFP_KERNEL),
4444 #else /* CONFIG_NUMA */
4446 static void set_zonelist_order(void)
4448 current_zonelist_order = ZONELIST_ORDER_ZONE;
4451 static void build_zonelists(pg_data_t *pgdat)
4453 int node, local_node;
4455 struct zonelist *zonelist;
4457 local_node = pgdat->node_id;
4459 zonelist = &pgdat->node_zonelists[0];
4460 j = build_zonelists_node(pgdat, zonelist, 0);
4463 * Now we build the zonelist so that it contains the zones
4464 * of all the other nodes.
4465 * We don't want to pressure a particular node, so when
4466 * building the zones for node N, we make sure that the
4467 * zones coming right after the local ones are those from
4468 * node N+1 (modulo N)
4470 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4471 if (!node_online(node))
4473 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4475 for (node = 0; node < local_node; node++) {
4476 if (!node_online(node))
4478 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4481 zonelist->_zonerefs[j].zone = NULL;
4482 zonelist->_zonerefs[j].zone_idx = 0;
4485 #endif /* CONFIG_NUMA */
4488 * Boot pageset table. One per cpu which is going to be used for all
4489 * zones and all nodes. The parameters will be set in such a way
4490 * that an item put on a list will immediately be handed over to
4491 * the buddy list. This is safe since pageset manipulation is done
4492 * with interrupts disabled.
4494 * The boot_pagesets must be kept even after bootup is complete for
4495 * unused processors and/or zones. They do play a role for bootstrapping
4496 * hotplugged processors.
4498 * zoneinfo_show() and maybe other functions do
4499 * not check if the processor is online before following the pageset pointer.
4500 * Other parts of the kernel may not check if the zone is available.
4502 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4503 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4504 static void setup_zone_pageset(struct zone *zone);
4507 * Global mutex to protect against size modification of zonelists
4508 * as well as to serialize pageset setup for the new populated zone.
4510 DEFINE_MUTEX(zonelists_mutex);
4512 /* return values int ....just for stop_machine() */
4513 static int __build_all_zonelists(void *data)
4517 pg_data_t *self = data;
4520 memset(node_load, 0, sizeof(node_load));
4523 if (self && !node_online(self->node_id)) {
4524 build_zonelists(self);
4527 for_each_online_node(nid) {
4528 pg_data_t *pgdat = NODE_DATA(nid);
4530 build_zonelists(pgdat);
4534 * Initialize the boot_pagesets that are going to be used
4535 * for bootstrapping processors. The real pagesets for
4536 * each zone will be allocated later when the per cpu
4537 * allocator is available.
4539 * boot_pagesets are used also for bootstrapping offline
4540 * cpus if the system is already booted because the pagesets
4541 * are needed to initialize allocators on a specific cpu too.
4542 * F.e. the percpu allocator needs the page allocator which
4543 * needs the percpu allocator in order to allocate its pagesets
4544 * (a chicken-egg dilemma).
4546 for_each_possible_cpu(cpu) {
4547 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4549 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4551 * We now know the "local memory node" for each node--
4552 * i.e., the node of the first zone in the generic zonelist.
4553 * Set up numa_mem percpu variable for on-line cpus. During
4554 * boot, only the boot cpu should be on-line; we'll init the
4555 * secondary cpus' numa_mem as they come on-line. During
4556 * node/memory hotplug, we'll fixup all on-line cpus.
4558 if (cpu_online(cpu))
4559 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4566 static noinline void __init
4567 build_all_zonelists_init(void)
4569 __build_all_zonelists(NULL);
4570 mminit_verify_zonelist();
4571 cpuset_init_current_mems_allowed();
4575 * Called with zonelists_mutex held always
4576 * unless system_state == SYSTEM_BOOTING.
4578 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4579 * [we're only called with non-NULL zone through __meminit paths] and
4580 * (2) call of __init annotated helper build_all_zonelists_init
4581 * [protected by SYSTEM_BOOTING].
4583 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4585 set_zonelist_order();
4587 if (system_state == SYSTEM_BOOTING) {
4588 build_all_zonelists_init();
4590 #ifdef CONFIG_MEMORY_HOTPLUG
4592 setup_zone_pageset(zone);
4594 /* we have to stop all cpus to guarantee there is no user
4596 stop_machine(__build_all_zonelists, pgdat, NULL);
4597 /* cpuset refresh routine should be here */
4599 vm_total_pages = nr_free_pagecache_pages();
4601 * Disable grouping by mobility if the number of pages in the
4602 * system is too low to allow the mechanism to work. It would be
4603 * more accurate, but expensive to check per-zone. This check is
4604 * made on memory-hotadd so a system can start with mobility
4605 * disabled and enable it later
4607 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4608 page_group_by_mobility_disabled = 1;
4610 page_group_by_mobility_disabled = 0;
4612 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4614 zonelist_order_name[current_zonelist_order],
4615 page_group_by_mobility_disabled ? "off" : "on",
4618 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4623 * Helper functions to size the waitqueue hash table.
4624 * Essentially these want to choose hash table sizes sufficiently
4625 * large so that collisions trying to wait on pages are rare.
4626 * But in fact, the number of active page waitqueues on typical
4627 * systems is ridiculously low, less than 200. So this is even
4628 * conservative, even though it seems large.
4630 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4631 * waitqueues, i.e. the size of the waitq table given the number of pages.
4633 #define PAGES_PER_WAITQUEUE 256
4635 #ifndef CONFIG_MEMORY_HOTPLUG
4636 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4638 unsigned long size = 1;
4640 pages /= PAGES_PER_WAITQUEUE;
4642 while (size < pages)
4646 * Once we have dozens or even hundreds of threads sleeping
4647 * on IO we've got bigger problems than wait queue collision.
4648 * Limit the size of the wait table to a reasonable size.
4650 size = min(size, 4096UL);
4652 return max(size, 4UL);
4656 * A zone's size might be changed by hot-add, so it is not possible to determine
4657 * a suitable size for its wait_table. So we use the maximum size now.
4659 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4661 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4662 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4663 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4665 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4666 * or more by the traditional way. (See above). It equals:
4668 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4669 * ia64(16K page size) : = ( 8G + 4M)byte.
4670 * powerpc (64K page size) : = (32G +16M)byte.
4672 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4679 * This is an integer logarithm so that shifts can be used later
4680 * to extract the more random high bits from the multiplicative
4681 * hash function before the remainder is taken.
4683 static inline unsigned long wait_table_bits(unsigned long size)
4689 * Initially all pages are reserved - free ones are freed
4690 * up by free_all_bootmem() once the early boot process is
4691 * done. Non-atomic initialization, single-pass.
4693 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4694 unsigned long start_pfn, enum memmap_context context)
4696 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
4697 unsigned long end_pfn = start_pfn + size;
4698 pg_data_t *pgdat = NODE_DATA(nid);
4700 unsigned long nr_initialised = 0;
4701 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4702 struct memblock_region *r = NULL, *tmp;
4705 if (highest_memmap_pfn < end_pfn - 1)
4706 highest_memmap_pfn = end_pfn - 1;
4709 * Honor reservation requested by the driver for this ZONE_DEVICE
4712 if (altmap && start_pfn == altmap->base_pfn)
4713 start_pfn += altmap->reserve;
4715 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4717 * There can be holes in boot-time mem_map[]s handed to this
4718 * function. They do not exist on hotplugged memory.
4720 if (context != MEMMAP_EARLY)
4723 if (!early_pfn_valid(pfn))
4725 if (!early_pfn_in_nid(pfn, nid))
4727 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
4730 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4732 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4733 * from zone_movable_pfn[nid] to end of each node should be
4734 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4736 if (!mirrored_kernelcore && zone_movable_pfn[nid])
4737 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
4741 * Check given memblock attribute by firmware which can affect
4742 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4743 * mirrored, it's an overlapped memmap init. skip it.
4745 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
4746 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
4747 for_each_memblock(memory, tmp)
4748 if (pfn < memblock_region_memory_end_pfn(tmp))
4752 if (pfn >= memblock_region_memory_base_pfn(r) &&
4753 memblock_is_mirror(r)) {
4754 /* already initialized as NORMAL */
4755 pfn = memblock_region_memory_end_pfn(r);
4763 * Mark the block movable so that blocks are reserved for
4764 * movable at startup. This will force kernel allocations
4765 * to reserve their blocks rather than leaking throughout
4766 * the address space during boot when many long-lived
4767 * kernel allocations are made.
4769 * bitmap is created for zone's valid pfn range. but memmap
4770 * can be created for invalid pages (for alignment)
4771 * check here not to call set_pageblock_migratetype() against
4774 if (!(pfn & (pageblock_nr_pages - 1))) {
4775 struct page *page = pfn_to_page(pfn);
4777 __init_single_page(page, pfn, zone, nid);
4778 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4780 __init_single_pfn(pfn, zone, nid);
4785 static void __meminit zone_init_free_lists(struct zone *zone)
4787 unsigned int order, t;
4788 for_each_migratetype_order(order, t) {
4789 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4790 zone->free_area[order].nr_free = 0;
4794 #ifndef __HAVE_ARCH_MEMMAP_INIT
4795 #define memmap_init(size, nid, zone, start_pfn) \
4796 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4799 static int zone_batchsize(struct zone *zone)
4805 * The per-cpu-pages pools are set to around 1000th of the
4806 * size of the zone. But no more than 1/2 of a meg.
4808 * OK, so we don't know how big the cache is. So guess.
4810 batch = zone->managed_pages / 1024;
4811 if (batch * PAGE_SIZE > 512 * 1024)
4812 batch = (512 * 1024) / PAGE_SIZE;
4813 batch /= 4; /* We effectively *= 4 below */
4818 * Clamp the batch to a 2^n - 1 value. Having a power
4819 * of 2 value was found to be more likely to have
4820 * suboptimal cache aliasing properties in some cases.
4822 * For example if 2 tasks are alternately allocating
4823 * batches of pages, one task can end up with a lot
4824 * of pages of one half of the possible page colors
4825 * and the other with pages of the other colors.
4827 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4832 /* The deferral and batching of frees should be suppressed under NOMMU
4835 * The problem is that NOMMU needs to be able to allocate large chunks
4836 * of contiguous memory as there's no hardware page translation to
4837 * assemble apparent contiguous memory from discontiguous pages.
4839 * Queueing large contiguous runs of pages for batching, however,
4840 * causes the pages to actually be freed in smaller chunks. As there
4841 * can be a significant delay between the individual batches being
4842 * recycled, this leads to the once large chunks of space being
4843 * fragmented and becoming unavailable for high-order allocations.
4850 * pcp->high and pcp->batch values are related and dependent on one another:
4851 * ->batch must never be higher then ->high.
4852 * The following function updates them in a safe manner without read side
4855 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4856 * those fields changing asynchronously (acording the the above rule).
4858 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4859 * outside of boot time (or some other assurance that no concurrent updaters
4862 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4863 unsigned long batch)
4865 /* start with a fail safe value for batch */
4869 /* Update high, then batch, in order */
4876 /* a companion to pageset_set_high() */
4877 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4879 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4882 static void pageset_init(struct per_cpu_pageset *p)
4884 struct per_cpu_pages *pcp;
4887 memset(p, 0, sizeof(*p));
4891 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4892 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4895 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4898 pageset_set_batch(p, batch);
4902 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4903 * to the value high for the pageset p.
4905 static void pageset_set_high(struct per_cpu_pageset *p,
4908 unsigned long batch = max(1UL, high / 4);
4909 if ((high / 4) > (PAGE_SHIFT * 8))
4910 batch = PAGE_SHIFT * 8;
4912 pageset_update(&p->pcp, high, batch);
4915 static void pageset_set_high_and_batch(struct zone *zone,
4916 struct per_cpu_pageset *pcp)
4918 if (percpu_pagelist_fraction)
4919 pageset_set_high(pcp,
4920 (zone->managed_pages /
4921 percpu_pagelist_fraction));
4923 pageset_set_batch(pcp, zone_batchsize(zone));
4926 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4928 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4931 pageset_set_high_and_batch(zone, pcp);
4934 static void __meminit setup_zone_pageset(struct zone *zone)
4937 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4938 for_each_possible_cpu(cpu)
4939 zone_pageset_init(zone, cpu);
4943 * Allocate per cpu pagesets and initialize them.
4944 * Before this call only boot pagesets were available.
4946 void __init setup_per_cpu_pageset(void)
4950 for_each_populated_zone(zone)
4951 setup_zone_pageset(zone);
4954 static noinline __init_refok
4955 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4961 * The per-page waitqueue mechanism uses hashed waitqueues
4964 zone->wait_table_hash_nr_entries =
4965 wait_table_hash_nr_entries(zone_size_pages);
4966 zone->wait_table_bits =
4967 wait_table_bits(zone->wait_table_hash_nr_entries);
4968 alloc_size = zone->wait_table_hash_nr_entries
4969 * sizeof(wait_queue_head_t);
4971 if (!slab_is_available()) {
4972 zone->wait_table = (wait_queue_head_t *)
4973 memblock_virt_alloc_node_nopanic(
4974 alloc_size, zone->zone_pgdat->node_id);
4977 * This case means that a zone whose size was 0 gets new memory
4978 * via memory hot-add.
4979 * But it may be the case that a new node was hot-added. In
4980 * this case vmalloc() will not be able to use this new node's
4981 * memory - this wait_table must be initialized to use this new
4982 * node itself as well.
4983 * To use this new node's memory, further consideration will be
4986 zone->wait_table = vmalloc(alloc_size);
4988 if (!zone->wait_table)
4991 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4992 init_waitqueue_head(zone->wait_table + i);
4997 static __meminit void zone_pcp_init(struct zone *zone)
5000 * per cpu subsystem is not up at this point. The following code
5001 * relies on the ability of the linker to provide the
5002 * offset of a (static) per cpu variable into the per cpu area.
5004 zone->pageset = &boot_pageset;
5006 if (populated_zone(zone))
5007 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5008 zone->name, zone->present_pages,
5009 zone_batchsize(zone));
5012 int __meminit init_currently_empty_zone(struct zone *zone,
5013 unsigned long zone_start_pfn,
5016 struct pglist_data *pgdat = zone->zone_pgdat;
5018 ret = zone_wait_table_init(zone, size);
5021 pgdat->nr_zones = zone_idx(zone) + 1;
5023 zone->zone_start_pfn = zone_start_pfn;
5025 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5026 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5028 (unsigned long)zone_idx(zone),
5029 zone_start_pfn, (zone_start_pfn + size));
5031 zone_init_free_lists(zone);
5036 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5037 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5040 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5042 int __meminit __early_pfn_to_nid(unsigned long pfn,
5043 struct mminit_pfnnid_cache *state)
5045 unsigned long start_pfn, end_pfn;
5048 if (state->last_start <= pfn && pfn < state->last_end)
5049 return state->last_nid;
5051 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5053 state->last_start = start_pfn;
5054 state->last_end = end_pfn;
5055 state->last_nid = nid;
5060 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5063 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5064 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5065 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5067 * If an architecture guarantees that all ranges registered contain no holes
5068 * and may be freed, this this function may be used instead of calling
5069 * memblock_free_early_nid() manually.
5071 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5073 unsigned long start_pfn, end_pfn;
5076 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5077 start_pfn = min(start_pfn, max_low_pfn);
5078 end_pfn = min(end_pfn, max_low_pfn);
5080 if (start_pfn < end_pfn)
5081 memblock_free_early_nid(PFN_PHYS(start_pfn),
5082 (end_pfn - start_pfn) << PAGE_SHIFT,
5088 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5089 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5091 * If an architecture guarantees that all ranges registered contain no holes and may
5092 * be freed, this function may be used instead of calling memory_present() manually.
5094 void __init sparse_memory_present_with_active_regions(int nid)
5096 unsigned long start_pfn, end_pfn;
5099 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5100 memory_present(this_nid, start_pfn, end_pfn);
5104 * get_pfn_range_for_nid - Return the start and end page frames for a node
5105 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5106 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5107 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5109 * It returns the start and end page frame of a node based on information
5110 * provided by memblock_set_node(). If called for a node
5111 * with no available memory, a warning is printed and the start and end
5114 void __meminit get_pfn_range_for_nid(unsigned int nid,
5115 unsigned long *start_pfn, unsigned long *end_pfn)
5117 unsigned long this_start_pfn, this_end_pfn;
5123 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5124 *start_pfn = min(*start_pfn, this_start_pfn);
5125 *end_pfn = max(*end_pfn, this_end_pfn);
5128 if (*start_pfn == -1UL)
5133 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5134 * assumption is made that zones within a node are ordered in monotonic
5135 * increasing memory addresses so that the "highest" populated zone is used
5137 static void __init find_usable_zone_for_movable(void)
5140 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5141 if (zone_index == ZONE_MOVABLE)
5144 if (arch_zone_highest_possible_pfn[zone_index] >
5145 arch_zone_lowest_possible_pfn[zone_index])
5149 VM_BUG_ON(zone_index == -1);
5150 movable_zone = zone_index;
5154 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5155 * because it is sized independent of architecture. Unlike the other zones,
5156 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5157 * in each node depending on the size of each node and how evenly kernelcore
5158 * is distributed. This helper function adjusts the zone ranges
5159 * provided by the architecture for a given node by using the end of the
5160 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5161 * zones within a node are in order of monotonic increases memory addresses
5163 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5164 unsigned long zone_type,
5165 unsigned long node_start_pfn,
5166 unsigned long node_end_pfn,
5167 unsigned long *zone_start_pfn,
5168 unsigned long *zone_end_pfn)
5170 /* Only adjust if ZONE_MOVABLE is on this node */
5171 if (zone_movable_pfn[nid]) {
5172 /* Size ZONE_MOVABLE */
5173 if (zone_type == ZONE_MOVABLE) {
5174 *zone_start_pfn = zone_movable_pfn[nid];
5175 *zone_end_pfn = min(node_end_pfn,
5176 arch_zone_highest_possible_pfn[movable_zone]);
5178 /* Check if this whole range is within ZONE_MOVABLE */
5179 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5180 *zone_start_pfn = *zone_end_pfn;
5185 * Return the number of pages a zone spans in a node, including holes
5186 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5188 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5189 unsigned long zone_type,
5190 unsigned long node_start_pfn,
5191 unsigned long node_end_pfn,
5192 unsigned long *zone_start_pfn,
5193 unsigned long *zone_end_pfn,
5194 unsigned long *ignored)
5196 /* When hotadd a new node from cpu_up(), the node should be empty */
5197 if (!node_start_pfn && !node_end_pfn)
5200 /* Get the start and end of the zone */
5201 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5202 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5203 adjust_zone_range_for_zone_movable(nid, zone_type,
5204 node_start_pfn, node_end_pfn,
5205 zone_start_pfn, zone_end_pfn);
5207 /* Check that this node has pages within the zone's required range */
5208 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5211 /* Move the zone boundaries inside the node if necessary */
5212 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5213 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5215 /* Return the spanned pages */
5216 return *zone_end_pfn - *zone_start_pfn;
5220 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5221 * then all holes in the requested range will be accounted for.
5223 unsigned long __meminit __absent_pages_in_range(int nid,
5224 unsigned long range_start_pfn,
5225 unsigned long range_end_pfn)
5227 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5228 unsigned long start_pfn, end_pfn;
5231 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5232 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5233 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5234 nr_absent -= end_pfn - start_pfn;
5240 * absent_pages_in_range - Return number of page frames in holes within a range
5241 * @start_pfn: The start PFN to start searching for holes
5242 * @end_pfn: The end PFN to stop searching for holes
5244 * It returns the number of pages frames in memory holes within a range.
5246 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5247 unsigned long end_pfn)
5249 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5252 /* Return the number of page frames in holes in a zone on a node */
5253 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5254 unsigned long zone_type,
5255 unsigned long node_start_pfn,
5256 unsigned long node_end_pfn,
5257 unsigned long *ignored)
5259 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5260 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5261 unsigned long zone_start_pfn, zone_end_pfn;
5262 unsigned long nr_absent;
5264 /* When hotadd a new node from cpu_up(), the node should be empty */
5265 if (!node_start_pfn && !node_end_pfn)
5268 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5269 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5271 adjust_zone_range_for_zone_movable(nid, zone_type,
5272 node_start_pfn, node_end_pfn,
5273 &zone_start_pfn, &zone_end_pfn);
5274 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5277 * ZONE_MOVABLE handling.
5278 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5281 if (zone_movable_pfn[nid]) {
5282 if (mirrored_kernelcore) {
5283 unsigned long start_pfn, end_pfn;
5284 struct memblock_region *r;
5286 for_each_memblock(memory, r) {
5287 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5288 zone_start_pfn, zone_end_pfn);
5289 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5290 zone_start_pfn, zone_end_pfn);
5292 if (zone_type == ZONE_MOVABLE &&
5293 memblock_is_mirror(r))
5294 nr_absent += end_pfn - start_pfn;
5296 if (zone_type == ZONE_NORMAL &&
5297 !memblock_is_mirror(r))
5298 nr_absent += end_pfn - start_pfn;
5301 if (zone_type == ZONE_NORMAL)
5302 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5309 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5310 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5311 unsigned long zone_type,
5312 unsigned long node_start_pfn,
5313 unsigned long node_end_pfn,
5314 unsigned long *zone_start_pfn,
5315 unsigned long *zone_end_pfn,
5316 unsigned long *zones_size)
5320 *zone_start_pfn = node_start_pfn;
5321 for (zone = 0; zone < zone_type; zone++)
5322 *zone_start_pfn += zones_size[zone];
5324 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5326 return zones_size[zone_type];
5329 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5330 unsigned long zone_type,
5331 unsigned long node_start_pfn,
5332 unsigned long node_end_pfn,
5333 unsigned long *zholes_size)
5338 return zholes_size[zone_type];
5341 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5343 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5344 unsigned long node_start_pfn,
5345 unsigned long node_end_pfn,
5346 unsigned long *zones_size,
5347 unsigned long *zholes_size)
5349 unsigned long realtotalpages = 0, totalpages = 0;
5352 for (i = 0; i < MAX_NR_ZONES; i++) {
5353 struct zone *zone = pgdat->node_zones + i;
5354 unsigned long zone_start_pfn, zone_end_pfn;
5355 unsigned long size, real_size;
5357 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5363 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5364 node_start_pfn, node_end_pfn,
5367 zone->zone_start_pfn = zone_start_pfn;
5369 zone->zone_start_pfn = 0;
5370 zone->spanned_pages = size;
5371 zone->present_pages = real_size;
5374 realtotalpages += real_size;
5377 pgdat->node_spanned_pages = totalpages;
5378 pgdat->node_present_pages = realtotalpages;
5379 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5383 #ifndef CONFIG_SPARSEMEM
5385 * Calculate the size of the zone->blockflags rounded to an unsigned long
5386 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5387 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5388 * round what is now in bits to nearest long in bits, then return it in
5391 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5393 unsigned long usemapsize;
5395 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5396 usemapsize = roundup(zonesize, pageblock_nr_pages);
5397 usemapsize = usemapsize >> pageblock_order;
5398 usemapsize *= NR_PAGEBLOCK_BITS;
5399 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5401 return usemapsize / 8;
5404 static void __init setup_usemap(struct pglist_data *pgdat,
5406 unsigned long zone_start_pfn,
5407 unsigned long zonesize)
5409 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5410 zone->pageblock_flags = NULL;
5412 zone->pageblock_flags =
5413 memblock_virt_alloc_node_nopanic(usemapsize,
5417 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5418 unsigned long zone_start_pfn, unsigned long zonesize) {}
5419 #endif /* CONFIG_SPARSEMEM */
5421 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5423 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5424 void __paginginit set_pageblock_order(void)
5428 /* Check that pageblock_nr_pages has not already been setup */
5429 if (pageblock_order)
5432 if (HPAGE_SHIFT > PAGE_SHIFT)
5433 order = HUGETLB_PAGE_ORDER;
5435 order = MAX_ORDER - 1;
5438 * Assume the largest contiguous order of interest is a huge page.
5439 * This value may be variable depending on boot parameters on IA64 and
5442 pageblock_order = order;
5444 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5447 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5448 * is unused as pageblock_order is set at compile-time. See
5449 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5452 void __paginginit set_pageblock_order(void)
5456 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5458 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5459 unsigned long present_pages)
5461 unsigned long pages = spanned_pages;
5464 * Provide a more accurate estimation if there are holes within
5465 * the zone and SPARSEMEM is in use. If there are holes within the
5466 * zone, each populated memory region may cost us one or two extra
5467 * memmap pages due to alignment because memmap pages for each
5468 * populated regions may not naturally algined on page boundary.
5469 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5471 if (spanned_pages > present_pages + (present_pages >> 4) &&
5472 IS_ENABLED(CONFIG_SPARSEMEM))
5473 pages = present_pages;
5475 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5479 * Set up the zone data structures:
5480 * - mark all pages reserved
5481 * - mark all memory queues empty
5482 * - clear the memory bitmaps
5484 * NOTE: pgdat should get zeroed by caller.
5486 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5489 int nid = pgdat->node_id;
5492 pgdat_resize_init(pgdat);
5493 #ifdef CONFIG_NUMA_BALANCING
5494 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5495 pgdat->numabalancing_migrate_nr_pages = 0;
5496 pgdat->numabalancing_migrate_next_window = jiffies;
5498 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5499 spin_lock_init(&pgdat->split_queue_lock);
5500 INIT_LIST_HEAD(&pgdat->split_queue);
5501 pgdat->split_queue_len = 0;
5503 init_waitqueue_head(&pgdat->kswapd_wait);
5504 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5505 #ifdef CONFIG_COMPACTION
5506 init_waitqueue_head(&pgdat->kcompactd_wait);
5508 pgdat_page_ext_init(pgdat);
5510 for (j = 0; j < MAX_NR_ZONES; j++) {
5511 struct zone *zone = pgdat->node_zones + j;
5512 unsigned long size, realsize, freesize, memmap_pages;
5513 unsigned long zone_start_pfn = zone->zone_start_pfn;
5515 size = zone->spanned_pages;
5516 realsize = freesize = zone->present_pages;
5519 * Adjust freesize so that it accounts for how much memory
5520 * is used by this zone for memmap. This affects the watermark
5521 * and per-cpu initialisations
5523 memmap_pages = calc_memmap_size(size, realsize);
5524 if (!is_highmem_idx(j)) {
5525 if (freesize >= memmap_pages) {
5526 freesize -= memmap_pages;
5529 " %s zone: %lu pages used for memmap\n",
5530 zone_names[j], memmap_pages);
5532 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5533 zone_names[j], memmap_pages, freesize);
5536 /* Account for reserved pages */
5537 if (j == 0 && freesize > dma_reserve) {
5538 freesize -= dma_reserve;
5539 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5540 zone_names[0], dma_reserve);
5543 if (!is_highmem_idx(j))
5544 nr_kernel_pages += freesize;
5545 /* Charge for highmem memmap if there are enough kernel pages */
5546 else if (nr_kernel_pages > memmap_pages * 2)
5547 nr_kernel_pages -= memmap_pages;
5548 nr_all_pages += freesize;
5551 * Set an approximate value for lowmem here, it will be adjusted
5552 * when the bootmem allocator frees pages into the buddy system.
5553 * And all highmem pages will be managed by the buddy system.
5555 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5558 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5560 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5562 zone->name = zone_names[j];
5563 spin_lock_init(&zone->lock);
5564 spin_lock_init(&zone->lru_lock);
5565 zone_seqlock_init(zone);
5566 zone->zone_pgdat = pgdat;
5567 zone_pcp_init(zone);
5569 /* For bootup, initialized properly in watermark setup */
5570 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5572 lruvec_init(&zone->lruvec);
5576 set_pageblock_order();
5577 setup_usemap(pgdat, zone, zone_start_pfn, size);
5578 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5580 memmap_init(size, nid, j, zone_start_pfn);
5584 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5586 unsigned long __maybe_unused start = 0;
5587 unsigned long __maybe_unused offset = 0;
5589 /* Skip empty nodes */
5590 if (!pgdat->node_spanned_pages)
5593 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5594 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5595 offset = pgdat->node_start_pfn - start;
5596 /* ia64 gets its own node_mem_map, before this, without bootmem */
5597 if (!pgdat->node_mem_map) {
5598 unsigned long size, end;
5602 * The zone's endpoints aren't required to be MAX_ORDER
5603 * aligned but the node_mem_map endpoints must be in order
5604 * for the buddy allocator to function correctly.
5606 end = pgdat_end_pfn(pgdat);
5607 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5608 size = (end - start) * sizeof(struct page);
5609 map = alloc_remap(pgdat->node_id, size);
5611 map = memblock_virt_alloc_node_nopanic(size,
5613 pgdat->node_mem_map = map + offset;
5615 #ifndef CONFIG_NEED_MULTIPLE_NODES
5617 * With no DISCONTIG, the global mem_map is just set as node 0's
5619 if (pgdat == NODE_DATA(0)) {
5620 mem_map = NODE_DATA(0)->node_mem_map;
5621 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5622 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5624 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5627 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5630 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5631 unsigned long node_start_pfn, unsigned long *zholes_size)
5633 pg_data_t *pgdat = NODE_DATA(nid);
5634 unsigned long start_pfn = 0;
5635 unsigned long end_pfn = 0;
5637 /* pg_data_t should be reset to zero when it's allocated */
5638 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5640 reset_deferred_meminit(pgdat);
5641 pgdat->node_id = nid;
5642 pgdat->node_start_pfn = node_start_pfn;
5643 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5644 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5645 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5646 (u64)start_pfn << PAGE_SHIFT,
5647 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5649 start_pfn = node_start_pfn;
5651 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5652 zones_size, zholes_size);
5654 alloc_node_mem_map(pgdat);
5655 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5656 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5657 nid, (unsigned long)pgdat,
5658 (unsigned long)pgdat->node_mem_map);
5661 free_area_init_core(pgdat);
5664 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5666 #if MAX_NUMNODES > 1
5668 * Figure out the number of possible node ids.
5670 void __init setup_nr_node_ids(void)
5672 unsigned int highest;
5674 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5675 nr_node_ids = highest + 1;
5680 * node_map_pfn_alignment - determine the maximum internode alignment
5682 * This function should be called after node map is populated and sorted.
5683 * It calculates the maximum power of two alignment which can distinguish
5686 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5687 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5688 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5689 * shifted, 1GiB is enough and this function will indicate so.
5691 * This is used to test whether pfn -> nid mapping of the chosen memory
5692 * model has fine enough granularity to avoid incorrect mapping for the
5693 * populated node map.
5695 * Returns the determined alignment in pfn's. 0 if there is no alignment
5696 * requirement (single node).
5698 unsigned long __init node_map_pfn_alignment(void)
5700 unsigned long accl_mask = 0, last_end = 0;
5701 unsigned long start, end, mask;
5705 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5706 if (!start || last_nid < 0 || last_nid == nid) {
5713 * Start with a mask granular enough to pin-point to the
5714 * start pfn and tick off bits one-by-one until it becomes
5715 * too coarse to separate the current node from the last.
5717 mask = ~((1 << __ffs(start)) - 1);
5718 while (mask && last_end <= (start & (mask << 1)))
5721 /* accumulate all internode masks */
5725 /* convert mask to number of pages */
5726 return ~accl_mask + 1;
5729 /* Find the lowest pfn for a node */
5730 static unsigned long __init find_min_pfn_for_node(int nid)
5732 unsigned long min_pfn = ULONG_MAX;
5733 unsigned long start_pfn;
5736 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5737 min_pfn = min(min_pfn, start_pfn);
5739 if (min_pfn == ULONG_MAX) {
5740 pr_warn("Could not find start_pfn for node %d\n", nid);
5748 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5750 * It returns the minimum PFN based on information provided via
5751 * memblock_set_node().
5753 unsigned long __init find_min_pfn_with_active_regions(void)
5755 return find_min_pfn_for_node(MAX_NUMNODES);
5759 * early_calculate_totalpages()
5760 * Sum pages in active regions for movable zone.
5761 * Populate N_MEMORY for calculating usable_nodes.
5763 static unsigned long __init early_calculate_totalpages(void)
5765 unsigned long totalpages = 0;
5766 unsigned long start_pfn, end_pfn;
5769 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5770 unsigned long pages = end_pfn - start_pfn;
5772 totalpages += pages;
5774 node_set_state(nid, N_MEMORY);
5780 * Find the PFN the Movable zone begins in each node. Kernel memory
5781 * is spread evenly between nodes as long as the nodes have enough
5782 * memory. When they don't, some nodes will have more kernelcore than
5785 static void __init find_zone_movable_pfns_for_nodes(void)
5788 unsigned long usable_startpfn;
5789 unsigned long kernelcore_node, kernelcore_remaining;
5790 /* save the state before borrow the nodemask */
5791 nodemask_t saved_node_state = node_states[N_MEMORY];
5792 unsigned long totalpages = early_calculate_totalpages();
5793 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5794 struct memblock_region *r;
5796 /* Need to find movable_zone earlier when movable_node is specified. */
5797 find_usable_zone_for_movable();
5800 * If movable_node is specified, ignore kernelcore and movablecore
5803 if (movable_node_is_enabled()) {
5804 for_each_memblock(memory, r) {
5805 if (!memblock_is_hotpluggable(r))
5810 usable_startpfn = PFN_DOWN(r->base);
5811 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5812 min(usable_startpfn, zone_movable_pfn[nid]) :
5820 * If kernelcore=mirror is specified, ignore movablecore option
5822 if (mirrored_kernelcore) {
5823 bool mem_below_4gb_not_mirrored = false;
5825 for_each_memblock(memory, r) {
5826 if (memblock_is_mirror(r))
5831 usable_startpfn = memblock_region_memory_base_pfn(r);
5833 if (usable_startpfn < 0x100000) {
5834 mem_below_4gb_not_mirrored = true;
5838 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5839 min(usable_startpfn, zone_movable_pfn[nid]) :
5843 if (mem_below_4gb_not_mirrored)
5844 pr_warn("This configuration results in unmirrored kernel memory.");
5850 * If movablecore=nn[KMG] was specified, calculate what size of
5851 * kernelcore that corresponds so that memory usable for
5852 * any allocation type is evenly spread. If both kernelcore
5853 * and movablecore are specified, then the value of kernelcore
5854 * will be used for required_kernelcore if it's greater than
5855 * what movablecore would have allowed.
5857 if (required_movablecore) {
5858 unsigned long corepages;
5861 * Round-up so that ZONE_MOVABLE is at least as large as what
5862 * was requested by the user
5864 required_movablecore =
5865 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5866 required_movablecore = min(totalpages, required_movablecore);
5867 corepages = totalpages - required_movablecore;
5869 required_kernelcore = max(required_kernelcore, corepages);
5873 * If kernelcore was not specified or kernelcore size is larger
5874 * than totalpages, there is no ZONE_MOVABLE.
5876 if (!required_kernelcore || required_kernelcore >= totalpages)
5879 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5880 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5883 /* Spread kernelcore memory as evenly as possible throughout nodes */
5884 kernelcore_node = required_kernelcore / usable_nodes;
5885 for_each_node_state(nid, N_MEMORY) {
5886 unsigned long start_pfn, end_pfn;
5889 * Recalculate kernelcore_node if the division per node
5890 * now exceeds what is necessary to satisfy the requested
5891 * amount of memory for the kernel
5893 if (required_kernelcore < kernelcore_node)
5894 kernelcore_node = required_kernelcore / usable_nodes;
5897 * As the map is walked, we track how much memory is usable
5898 * by the kernel using kernelcore_remaining. When it is
5899 * 0, the rest of the node is usable by ZONE_MOVABLE
5901 kernelcore_remaining = kernelcore_node;
5903 /* Go through each range of PFNs within this node */
5904 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5905 unsigned long size_pages;
5907 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5908 if (start_pfn >= end_pfn)
5911 /* Account for what is only usable for kernelcore */
5912 if (start_pfn < usable_startpfn) {
5913 unsigned long kernel_pages;
5914 kernel_pages = min(end_pfn, usable_startpfn)
5917 kernelcore_remaining -= min(kernel_pages,
5918 kernelcore_remaining);
5919 required_kernelcore -= min(kernel_pages,
5920 required_kernelcore);
5922 /* Continue if range is now fully accounted */
5923 if (end_pfn <= usable_startpfn) {
5926 * Push zone_movable_pfn to the end so
5927 * that if we have to rebalance
5928 * kernelcore across nodes, we will
5929 * not double account here
5931 zone_movable_pfn[nid] = end_pfn;
5934 start_pfn = usable_startpfn;
5938 * The usable PFN range for ZONE_MOVABLE is from
5939 * start_pfn->end_pfn. Calculate size_pages as the
5940 * number of pages used as kernelcore
5942 size_pages = end_pfn - start_pfn;
5943 if (size_pages > kernelcore_remaining)
5944 size_pages = kernelcore_remaining;
5945 zone_movable_pfn[nid] = start_pfn + size_pages;
5948 * Some kernelcore has been met, update counts and
5949 * break if the kernelcore for this node has been
5952 required_kernelcore -= min(required_kernelcore,
5954 kernelcore_remaining -= size_pages;
5955 if (!kernelcore_remaining)
5961 * If there is still required_kernelcore, we do another pass with one
5962 * less node in the count. This will push zone_movable_pfn[nid] further
5963 * along on the nodes that still have memory until kernelcore is
5967 if (usable_nodes && required_kernelcore > usable_nodes)
5971 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5972 for (nid = 0; nid < MAX_NUMNODES; nid++)
5973 zone_movable_pfn[nid] =
5974 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5977 /* restore the node_state */
5978 node_states[N_MEMORY] = saved_node_state;
5981 /* Any regular or high memory on that node ? */
5982 static void check_for_memory(pg_data_t *pgdat, int nid)
5984 enum zone_type zone_type;
5986 if (N_MEMORY == N_NORMAL_MEMORY)
5989 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5990 struct zone *zone = &pgdat->node_zones[zone_type];
5991 if (populated_zone(zone)) {
5992 node_set_state(nid, N_HIGH_MEMORY);
5993 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5994 zone_type <= ZONE_NORMAL)
5995 node_set_state(nid, N_NORMAL_MEMORY);
6002 * free_area_init_nodes - Initialise all pg_data_t and zone data
6003 * @max_zone_pfn: an array of max PFNs for each zone
6005 * This will call free_area_init_node() for each active node in the system.
6006 * Using the page ranges provided by memblock_set_node(), the size of each
6007 * zone in each node and their holes is calculated. If the maximum PFN
6008 * between two adjacent zones match, it is assumed that the zone is empty.
6009 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6010 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6011 * starts where the previous one ended. For example, ZONE_DMA32 starts
6012 * at arch_max_dma_pfn.
6014 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6016 unsigned long start_pfn, end_pfn;
6019 /* Record where the zone boundaries are */
6020 memset(arch_zone_lowest_possible_pfn, 0,
6021 sizeof(arch_zone_lowest_possible_pfn));
6022 memset(arch_zone_highest_possible_pfn, 0,
6023 sizeof(arch_zone_highest_possible_pfn));
6024 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
6025 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
6026 for (i = 1; i < MAX_NR_ZONES; i++) {
6027 if (i == ZONE_MOVABLE)
6029 arch_zone_lowest_possible_pfn[i] =
6030 arch_zone_highest_possible_pfn[i-1];
6031 arch_zone_highest_possible_pfn[i] =
6032 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
6034 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6035 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6037 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6038 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6039 find_zone_movable_pfns_for_nodes();
6041 /* Print out the zone ranges */
6042 pr_info("Zone ranges:\n");
6043 for (i = 0; i < MAX_NR_ZONES; i++) {
6044 if (i == ZONE_MOVABLE)
6046 pr_info(" %-8s ", zone_names[i]);
6047 if (arch_zone_lowest_possible_pfn[i] ==
6048 arch_zone_highest_possible_pfn[i])
6051 pr_cont("[mem %#018Lx-%#018Lx]\n",
6052 (u64)arch_zone_lowest_possible_pfn[i]
6054 ((u64)arch_zone_highest_possible_pfn[i]
6055 << PAGE_SHIFT) - 1);
6058 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6059 pr_info("Movable zone start for each node\n");
6060 for (i = 0; i < MAX_NUMNODES; i++) {
6061 if (zone_movable_pfn[i])
6062 pr_info(" Node %d: %#018Lx\n", i,
6063 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6066 /* Print out the early node map */
6067 pr_info("Early memory node ranges\n");
6068 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6069 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6070 (u64)start_pfn << PAGE_SHIFT,
6071 ((u64)end_pfn << PAGE_SHIFT) - 1);
6073 /* Initialise every node */
6074 mminit_verify_pageflags_layout();
6075 setup_nr_node_ids();
6076 for_each_online_node(nid) {
6077 pg_data_t *pgdat = NODE_DATA(nid);
6078 free_area_init_node(nid, NULL,
6079 find_min_pfn_for_node(nid), NULL);
6081 /* Any memory on that node */
6082 if (pgdat->node_present_pages)
6083 node_set_state(nid, N_MEMORY);
6084 check_for_memory(pgdat, nid);
6088 static int __init cmdline_parse_core(char *p, unsigned long *core)
6090 unsigned long long coremem;
6094 coremem = memparse(p, &p);
6095 *core = coremem >> PAGE_SHIFT;
6097 /* Paranoid check that UL is enough for the coremem value */
6098 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6104 * kernelcore=size sets the amount of memory for use for allocations that
6105 * cannot be reclaimed or migrated.
6107 static int __init cmdline_parse_kernelcore(char *p)
6109 /* parse kernelcore=mirror */
6110 if (parse_option_str(p, "mirror")) {
6111 mirrored_kernelcore = true;
6115 return cmdline_parse_core(p, &required_kernelcore);
6119 * movablecore=size sets the amount of memory for use for allocations that
6120 * can be reclaimed or migrated.
6122 static int __init cmdline_parse_movablecore(char *p)
6124 return cmdline_parse_core(p, &required_movablecore);
6127 early_param("kernelcore", cmdline_parse_kernelcore);
6128 early_param("movablecore", cmdline_parse_movablecore);
6130 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6132 void adjust_managed_page_count(struct page *page, long count)
6134 spin_lock(&managed_page_count_lock);
6135 page_zone(page)->managed_pages += count;
6136 totalram_pages += count;
6137 #ifdef CONFIG_HIGHMEM
6138 if (PageHighMem(page))
6139 totalhigh_pages += count;
6141 spin_unlock(&managed_page_count_lock);
6143 EXPORT_SYMBOL(adjust_managed_page_count);
6145 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6148 unsigned long pages = 0;
6150 start = (void *)PAGE_ALIGN((unsigned long)start);
6151 end = (void *)((unsigned long)end & PAGE_MASK);
6152 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6153 if ((unsigned int)poison <= 0xFF)
6154 memset(pos, poison, PAGE_SIZE);
6155 free_reserved_page(virt_to_page(pos));
6159 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6160 s, pages << (PAGE_SHIFT - 10), start, end);
6164 EXPORT_SYMBOL(free_reserved_area);
6166 #ifdef CONFIG_HIGHMEM
6167 void free_highmem_page(struct page *page)
6169 __free_reserved_page(page);
6171 page_zone(page)->managed_pages++;
6177 void __init mem_init_print_info(const char *str)
6179 unsigned long physpages, codesize, datasize, rosize, bss_size;
6180 unsigned long init_code_size, init_data_size;
6182 physpages = get_num_physpages();
6183 codesize = _etext - _stext;
6184 datasize = _edata - _sdata;
6185 rosize = __end_rodata - __start_rodata;
6186 bss_size = __bss_stop - __bss_start;
6187 init_data_size = __init_end - __init_begin;
6188 init_code_size = _einittext - _sinittext;
6191 * Detect special cases and adjust section sizes accordingly:
6192 * 1) .init.* may be embedded into .data sections
6193 * 2) .init.text.* may be out of [__init_begin, __init_end],
6194 * please refer to arch/tile/kernel/vmlinux.lds.S.
6195 * 3) .rodata.* may be embedded into .text or .data sections.
6197 #define adj_init_size(start, end, size, pos, adj) \
6199 if (start <= pos && pos < end && size > adj) \
6203 adj_init_size(__init_begin, __init_end, init_data_size,
6204 _sinittext, init_code_size);
6205 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6206 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6207 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6208 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6210 #undef adj_init_size
6212 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6213 #ifdef CONFIG_HIGHMEM
6217 nr_free_pages() << (PAGE_SHIFT - 10),
6218 physpages << (PAGE_SHIFT - 10),
6219 codesize >> 10, datasize >> 10, rosize >> 10,
6220 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6221 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6222 totalcma_pages << (PAGE_SHIFT - 10),
6223 #ifdef CONFIG_HIGHMEM
6224 totalhigh_pages << (PAGE_SHIFT - 10),
6226 str ? ", " : "", str ? str : "");
6230 * set_dma_reserve - set the specified number of pages reserved in the first zone
6231 * @new_dma_reserve: The number of pages to mark reserved
6233 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6234 * In the DMA zone, a significant percentage may be consumed by kernel image
6235 * and other unfreeable allocations which can skew the watermarks badly. This
6236 * function may optionally be used to account for unfreeable pages in the
6237 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6238 * smaller per-cpu batchsize.
6240 void __init set_dma_reserve(unsigned long new_dma_reserve)
6242 dma_reserve = new_dma_reserve;
6245 void __init free_area_init(unsigned long *zones_size)
6247 free_area_init_node(0, zones_size,
6248 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6251 static int page_alloc_cpu_notify(struct notifier_block *self,
6252 unsigned long action, void *hcpu)
6254 int cpu = (unsigned long)hcpu;
6256 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6257 lru_add_drain_cpu(cpu);
6261 * Spill the event counters of the dead processor
6262 * into the current processors event counters.
6263 * This artificially elevates the count of the current
6266 vm_events_fold_cpu(cpu);
6269 * Zero the differential counters of the dead processor
6270 * so that the vm statistics are consistent.
6272 * This is only okay since the processor is dead and cannot
6273 * race with what we are doing.
6275 cpu_vm_stats_fold(cpu);
6280 void __init page_alloc_init(void)
6282 hotcpu_notifier(page_alloc_cpu_notify, 0);
6286 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6287 * or min_free_kbytes changes.
6289 static void calculate_totalreserve_pages(void)
6291 struct pglist_data *pgdat;
6292 unsigned long reserve_pages = 0;
6293 enum zone_type i, j;
6295 for_each_online_pgdat(pgdat) {
6296 for (i = 0; i < MAX_NR_ZONES; i++) {
6297 struct zone *zone = pgdat->node_zones + i;
6300 /* Find valid and maximum lowmem_reserve in the zone */
6301 for (j = i; j < MAX_NR_ZONES; j++) {
6302 if (zone->lowmem_reserve[j] > max)
6303 max = zone->lowmem_reserve[j];
6306 /* we treat the high watermark as reserved pages. */
6307 max += high_wmark_pages(zone);
6309 if (max > zone->managed_pages)
6310 max = zone->managed_pages;
6312 zone->totalreserve_pages = max;
6314 reserve_pages += max;
6317 totalreserve_pages = reserve_pages;
6321 * setup_per_zone_lowmem_reserve - called whenever
6322 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6323 * has a correct pages reserved value, so an adequate number of
6324 * pages are left in the zone after a successful __alloc_pages().
6326 static void setup_per_zone_lowmem_reserve(void)
6328 struct pglist_data *pgdat;
6329 enum zone_type j, idx;
6331 for_each_online_pgdat(pgdat) {
6332 for (j = 0; j < MAX_NR_ZONES; j++) {
6333 struct zone *zone = pgdat->node_zones + j;
6334 unsigned long managed_pages = zone->managed_pages;
6336 zone->lowmem_reserve[j] = 0;
6340 struct zone *lower_zone;
6344 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6345 sysctl_lowmem_reserve_ratio[idx] = 1;
6347 lower_zone = pgdat->node_zones + idx;
6348 lower_zone->lowmem_reserve[j] = managed_pages /
6349 sysctl_lowmem_reserve_ratio[idx];
6350 managed_pages += lower_zone->managed_pages;
6355 /* update totalreserve_pages */
6356 calculate_totalreserve_pages();
6359 static void __setup_per_zone_wmarks(void)
6361 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6362 unsigned long lowmem_pages = 0;
6364 unsigned long flags;
6366 /* Calculate total number of !ZONE_HIGHMEM pages */
6367 for_each_zone(zone) {
6368 if (!is_highmem(zone))
6369 lowmem_pages += zone->managed_pages;
6372 for_each_zone(zone) {
6375 spin_lock_irqsave(&zone->lock, flags);
6376 tmp = (u64)pages_min * zone->managed_pages;
6377 do_div(tmp, lowmem_pages);
6378 if (is_highmem(zone)) {
6380 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6381 * need highmem pages, so cap pages_min to a small
6384 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6385 * deltas control asynch page reclaim, and so should
6386 * not be capped for highmem.
6388 unsigned long min_pages;
6390 min_pages = zone->managed_pages / 1024;
6391 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6392 zone->watermark[WMARK_MIN] = min_pages;
6395 * If it's a lowmem zone, reserve a number of pages
6396 * proportionate to the zone's size.
6398 zone->watermark[WMARK_MIN] = tmp;
6402 * Set the kswapd watermarks distance according to the
6403 * scale factor in proportion to available memory, but
6404 * ensure a minimum size on small systems.
6406 tmp = max_t(u64, tmp >> 2,
6407 mult_frac(zone->managed_pages,
6408 watermark_scale_factor, 10000));
6410 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6411 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6413 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6414 high_wmark_pages(zone) - low_wmark_pages(zone) -
6415 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6417 spin_unlock_irqrestore(&zone->lock, flags);
6420 /* update totalreserve_pages */
6421 calculate_totalreserve_pages();
6425 * setup_per_zone_wmarks - called when min_free_kbytes changes
6426 * or when memory is hot-{added|removed}
6428 * Ensures that the watermark[min,low,high] values for each zone are set
6429 * correctly with respect to min_free_kbytes.
6431 void setup_per_zone_wmarks(void)
6433 mutex_lock(&zonelists_mutex);
6434 __setup_per_zone_wmarks();
6435 mutex_unlock(&zonelists_mutex);
6439 * The inactive anon list should be small enough that the VM never has to
6440 * do too much work, but large enough that each inactive page has a chance
6441 * to be referenced again before it is swapped out.
6443 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6444 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6445 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6446 * the anonymous pages are kept on the inactive list.
6449 * memory ratio inactive anon
6450 * -------------------------------------
6459 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6461 unsigned int gb, ratio;
6463 /* Zone size in gigabytes */
6464 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6466 ratio = int_sqrt(10 * gb);
6470 zone->inactive_ratio = ratio;
6473 static void __meminit setup_per_zone_inactive_ratio(void)
6478 calculate_zone_inactive_ratio(zone);
6482 * Initialise min_free_kbytes.
6484 * For small machines we want it small (128k min). For large machines
6485 * we want it large (64MB max). But it is not linear, because network
6486 * bandwidth does not increase linearly with machine size. We use
6488 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6489 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6505 int __meminit init_per_zone_wmark_min(void)
6507 unsigned long lowmem_kbytes;
6508 int new_min_free_kbytes;
6510 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6511 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6513 if (new_min_free_kbytes > user_min_free_kbytes) {
6514 min_free_kbytes = new_min_free_kbytes;
6515 if (min_free_kbytes < 128)
6516 min_free_kbytes = 128;
6517 if (min_free_kbytes > 65536)
6518 min_free_kbytes = 65536;
6520 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6521 new_min_free_kbytes, user_min_free_kbytes);
6523 setup_per_zone_wmarks();
6524 refresh_zone_stat_thresholds();
6525 setup_per_zone_lowmem_reserve();
6526 setup_per_zone_inactive_ratio();
6529 core_initcall(init_per_zone_wmark_min)
6532 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6533 * that we can call two helper functions whenever min_free_kbytes
6536 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6537 void __user *buffer, size_t *length, loff_t *ppos)
6541 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6546 user_min_free_kbytes = min_free_kbytes;
6547 setup_per_zone_wmarks();
6552 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6553 void __user *buffer, size_t *length, loff_t *ppos)
6557 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6562 setup_per_zone_wmarks();
6568 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6569 void __user *buffer, size_t *length, loff_t *ppos)
6574 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6579 zone->min_unmapped_pages = (zone->managed_pages *
6580 sysctl_min_unmapped_ratio) / 100;
6584 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6585 void __user *buffer, size_t *length, loff_t *ppos)
6590 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6595 zone->min_slab_pages = (zone->managed_pages *
6596 sysctl_min_slab_ratio) / 100;
6602 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6603 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6604 * whenever sysctl_lowmem_reserve_ratio changes.
6606 * The reserve ratio obviously has absolutely no relation with the
6607 * minimum watermarks. The lowmem reserve ratio can only make sense
6608 * if in function of the boot time zone sizes.
6610 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6611 void __user *buffer, size_t *length, loff_t *ppos)
6613 proc_dointvec_minmax(table, write, buffer, length, ppos);
6614 setup_per_zone_lowmem_reserve();
6619 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6620 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6621 * pagelist can have before it gets flushed back to buddy allocator.
6623 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6624 void __user *buffer, size_t *length, loff_t *ppos)
6627 int old_percpu_pagelist_fraction;
6630 mutex_lock(&pcp_batch_high_lock);
6631 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6633 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6634 if (!write || ret < 0)
6637 /* Sanity checking to avoid pcp imbalance */
6638 if (percpu_pagelist_fraction &&
6639 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6640 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6646 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6649 for_each_populated_zone(zone) {
6652 for_each_possible_cpu(cpu)
6653 pageset_set_high_and_batch(zone,
6654 per_cpu_ptr(zone->pageset, cpu));
6657 mutex_unlock(&pcp_batch_high_lock);
6662 int hashdist = HASHDIST_DEFAULT;
6664 static int __init set_hashdist(char *str)
6668 hashdist = simple_strtoul(str, &str, 0);
6671 __setup("hashdist=", set_hashdist);
6675 * allocate a large system hash table from bootmem
6676 * - it is assumed that the hash table must contain an exact power-of-2
6677 * quantity of entries
6678 * - limit is the number of hash buckets, not the total allocation size
6680 void *__init alloc_large_system_hash(const char *tablename,
6681 unsigned long bucketsize,
6682 unsigned long numentries,
6685 unsigned int *_hash_shift,
6686 unsigned int *_hash_mask,
6687 unsigned long low_limit,
6688 unsigned long high_limit)
6690 unsigned long long max = high_limit;
6691 unsigned long log2qty, size;
6694 /* allow the kernel cmdline to have a say */
6696 /* round applicable memory size up to nearest megabyte */
6697 numentries = nr_kernel_pages;
6699 /* It isn't necessary when PAGE_SIZE >= 1MB */
6700 if (PAGE_SHIFT < 20)
6701 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6703 /* limit to 1 bucket per 2^scale bytes of low memory */
6704 if (scale > PAGE_SHIFT)
6705 numentries >>= (scale - PAGE_SHIFT);
6707 numentries <<= (PAGE_SHIFT - scale);
6709 /* Make sure we've got at least a 0-order allocation.. */
6710 if (unlikely(flags & HASH_SMALL)) {
6711 /* Makes no sense without HASH_EARLY */
6712 WARN_ON(!(flags & HASH_EARLY));
6713 if (!(numentries >> *_hash_shift)) {
6714 numentries = 1UL << *_hash_shift;
6715 BUG_ON(!numentries);
6717 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6718 numentries = PAGE_SIZE / bucketsize;
6720 numentries = roundup_pow_of_two(numentries);
6722 /* limit allocation size to 1/16 total memory by default */
6724 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6725 do_div(max, bucketsize);
6727 max = min(max, 0x80000000ULL);
6729 if (numentries < low_limit)
6730 numentries = low_limit;
6731 if (numentries > max)
6734 log2qty = ilog2(numentries);
6737 size = bucketsize << log2qty;
6738 if (flags & HASH_EARLY)
6739 table = memblock_virt_alloc_nopanic(size, 0);
6741 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6744 * If bucketsize is not a power-of-two, we may free
6745 * some pages at the end of hash table which
6746 * alloc_pages_exact() automatically does
6748 if (get_order(size) < MAX_ORDER) {
6749 table = alloc_pages_exact(size, GFP_ATOMIC);
6750 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6753 } while (!table && size > PAGE_SIZE && --log2qty);
6756 panic("Failed to allocate %s hash table\n", tablename);
6758 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6759 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
6762 *_hash_shift = log2qty;
6764 *_hash_mask = (1 << log2qty) - 1;
6769 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6770 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6773 #ifdef CONFIG_SPARSEMEM
6774 return __pfn_to_section(pfn)->pageblock_flags;
6776 return zone->pageblock_flags;
6777 #endif /* CONFIG_SPARSEMEM */
6780 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6782 #ifdef CONFIG_SPARSEMEM
6783 pfn &= (PAGES_PER_SECTION-1);
6784 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6786 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6787 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6788 #endif /* CONFIG_SPARSEMEM */
6792 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6793 * @page: The page within the block of interest
6794 * @pfn: The target page frame number
6795 * @end_bitidx: The last bit of interest to retrieve
6796 * @mask: mask of bits that the caller is interested in
6798 * Return: pageblock_bits flags
6800 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6801 unsigned long end_bitidx,
6805 unsigned long *bitmap;
6806 unsigned long bitidx, word_bitidx;
6809 zone = page_zone(page);
6810 bitmap = get_pageblock_bitmap(zone, pfn);
6811 bitidx = pfn_to_bitidx(zone, pfn);
6812 word_bitidx = bitidx / BITS_PER_LONG;
6813 bitidx &= (BITS_PER_LONG-1);
6815 word = bitmap[word_bitidx];
6816 bitidx += end_bitidx;
6817 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6821 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6822 * @page: The page within the block of interest
6823 * @flags: The flags to set
6824 * @pfn: The target page frame number
6825 * @end_bitidx: The last bit of interest
6826 * @mask: mask of bits that the caller is interested in
6828 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6830 unsigned long end_bitidx,
6834 unsigned long *bitmap;
6835 unsigned long bitidx, word_bitidx;
6836 unsigned long old_word, word;
6838 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6840 zone = page_zone(page);
6841 bitmap = get_pageblock_bitmap(zone, pfn);
6842 bitidx = pfn_to_bitidx(zone, pfn);
6843 word_bitidx = bitidx / BITS_PER_LONG;
6844 bitidx &= (BITS_PER_LONG-1);
6846 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6848 bitidx += end_bitidx;
6849 mask <<= (BITS_PER_LONG - bitidx - 1);
6850 flags <<= (BITS_PER_LONG - bitidx - 1);
6852 word = READ_ONCE(bitmap[word_bitidx]);
6854 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6855 if (word == old_word)
6862 * This function checks whether pageblock includes unmovable pages or not.
6863 * If @count is not zero, it is okay to include less @count unmovable pages
6865 * PageLRU check without isolation or lru_lock could race so that
6866 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6867 * expect this function should be exact.
6869 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6870 bool skip_hwpoisoned_pages)
6872 unsigned long pfn, iter, found;
6876 * For avoiding noise data, lru_add_drain_all() should be called
6877 * If ZONE_MOVABLE, the zone never contains unmovable pages
6879 if (zone_idx(zone) == ZONE_MOVABLE)
6881 mt = get_pageblock_migratetype(page);
6882 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6885 pfn = page_to_pfn(page);
6886 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6887 unsigned long check = pfn + iter;
6889 if (!pfn_valid_within(check))
6892 page = pfn_to_page(check);
6895 * Hugepages are not in LRU lists, but they're movable.
6896 * We need not scan over tail pages bacause we don't
6897 * handle each tail page individually in migration.
6899 if (PageHuge(page)) {
6900 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6905 * We can't use page_count without pin a page
6906 * because another CPU can free compound page.
6907 * This check already skips compound tails of THP
6908 * because their page->_refcount is zero at all time.
6910 if (!page_ref_count(page)) {
6911 if (PageBuddy(page))
6912 iter += (1 << page_order(page)) - 1;
6917 * The HWPoisoned page may be not in buddy system, and
6918 * page_count() is not 0.
6920 if (skip_hwpoisoned_pages && PageHWPoison(page))
6926 * If there are RECLAIMABLE pages, we need to check
6927 * it. But now, memory offline itself doesn't call
6928 * shrink_node_slabs() and it still to be fixed.
6931 * If the page is not RAM, page_count()should be 0.
6932 * we don't need more check. This is an _used_ not-movable page.
6934 * The problematic thing here is PG_reserved pages. PG_reserved
6935 * is set to both of a memory hole page and a _used_ kernel
6944 bool is_pageblock_removable_nolock(struct page *page)
6950 * We have to be careful here because we are iterating over memory
6951 * sections which are not zone aware so we might end up outside of
6952 * the zone but still within the section.
6953 * We have to take care about the node as well. If the node is offline
6954 * its NODE_DATA will be NULL - see page_zone.
6956 if (!node_online(page_to_nid(page)))
6959 zone = page_zone(page);
6960 pfn = page_to_pfn(page);
6961 if (!zone_spans_pfn(zone, pfn))
6964 return !has_unmovable_pages(zone, page, 0, true);
6967 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6969 static unsigned long pfn_max_align_down(unsigned long pfn)
6971 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6972 pageblock_nr_pages) - 1);
6975 static unsigned long pfn_max_align_up(unsigned long pfn)
6977 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6978 pageblock_nr_pages));
6981 /* [start, end) must belong to a single zone. */
6982 static int __alloc_contig_migrate_range(struct compact_control *cc,
6983 unsigned long start, unsigned long end)
6985 /* This function is based on compact_zone() from compaction.c. */
6986 unsigned long nr_reclaimed;
6987 unsigned long pfn = start;
6988 unsigned int tries = 0;
6993 while (pfn < end || !list_empty(&cc->migratepages)) {
6994 if (fatal_signal_pending(current)) {
6999 if (list_empty(&cc->migratepages)) {
7000 cc->nr_migratepages = 0;
7001 pfn = isolate_migratepages_range(cc, pfn, end);
7007 } else if (++tries == 5) {
7008 ret = ret < 0 ? ret : -EBUSY;
7012 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7014 cc->nr_migratepages -= nr_reclaimed;
7016 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7017 NULL, 0, cc->mode, MR_CMA);
7020 putback_movable_pages(&cc->migratepages);
7027 * alloc_contig_range() -- tries to allocate given range of pages
7028 * @start: start PFN to allocate
7029 * @end: one-past-the-last PFN to allocate
7030 * @migratetype: migratetype of the underlaying pageblocks (either
7031 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7032 * in range must have the same migratetype and it must
7033 * be either of the two.
7035 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7036 * aligned, however it's the caller's responsibility to guarantee that
7037 * we are the only thread that changes migrate type of pageblocks the
7040 * The PFN range must belong to a single zone.
7042 * Returns zero on success or negative error code. On success all
7043 * pages which PFN is in [start, end) are allocated for the caller and
7044 * need to be freed with free_contig_range().
7046 int alloc_contig_range(unsigned long start, unsigned long end,
7047 unsigned migratetype)
7049 unsigned long outer_start, outer_end;
7053 struct compact_control cc = {
7054 .nr_migratepages = 0,
7056 .zone = page_zone(pfn_to_page(start)),
7057 .mode = MIGRATE_SYNC,
7058 .ignore_skip_hint = true,
7060 INIT_LIST_HEAD(&cc.migratepages);
7063 * What we do here is we mark all pageblocks in range as
7064 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7065 * have different sizes, and due to the way page allocator
7066 * work, we align the range to biggest of the two pages so
7067 * that page allocator won't try to merge buddies from
7068 * different pageblocks and change MIGRATE_ISOLATE to some
7069 * other migration type.
7071 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7072 * migrate the pages from an unaligned range (ie. pages that
7073 * we are interested in). This will put all the pages in
7074 * range back to page allocator as MIGRATE_ISOLATE.
7076 * When this is done, we take the pages in range from page
7077 * allocator removing them from the buddy system. This way
7078 * page allocator will never consider using them.
7080 * This lets us mark the pageblocks back as
7081 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7082 * aligned range but not in the unaligned, original range are
7083 * put back to page allocator so that buddy can use them.
7086 ret = start_isolate_page_range(pfn_max_align_down(start),
7087 pfn_max_align_up(end), migratetype,
7093 * In case of -EBUSY, we'd like to know which page causes problem.
7094 * So, just fall through. We will check it in test_pages_isolated().
7096 ret = __alloc_contig_migrate_range(&cc, start, end);
7097 if (ret && ret != -EBUSY)
7101 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7102 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7103 * more, all pages in [start, end) are free in page allocator.
7104 * What we are going to do is to allocate all pages from
7105 * [start, end) (that is remove them from page allocator).
7107 * The only problem is that pages at the beginning and at the
7108 * end of interesting range may be not aligned with pages that
7109 * page allocator holds, ie. they can be part of higher order
7110 * pages. Because of this, we reserve the bigger range and
7111 * once this is done free the pages we are not interested in.
7113 * We don't have to hold zone->lock here because the pages are
7114 * isolated thus they won't get removed from buddy.
7117 lru_add_drain_all();
7118 drain_all_pages(cc.zone);
7121 outer_start = start;
7122 while (!PageBuddy(pfn_to_page(outer_start))) {
7123 if (++order >= MAX_ORDER) {
7124 outer_start = start;
7127 outer_start &= ~0UL << order;
7130 if (outer_start != start) {
7131 order = page_order(pfn_to_page(outer_start));
7134 * outer_start page could be small order buddy page and
7135 * it doesn't include start page. Adjust outer_start
7136 * in this case to report failed page properly
7137 * on tracepoint in test_pages_isolated()
7139 if (outer_start + (1UL << order) <= start)
7140 outer_start = start;
7143 /* Make sure the range is really isolated. */
7144 if (test_pages_isolated(outer_start, end, false)) {
7145 pr_info("%s: [%lx, %lx) PFNs busy\n",
7146 __func__, outer_start, end);
7151 /* Grab isolated pages from freelists. */
7152 outer_end = isolate_freepages_range(&cc, outer_start, end);
7158 /* Free head and tail (if any) */
7159 if (start != outer_start)
7160 free_contig_range(outer_start, start - outer_start);
7161 if (end != outer_end)
7162 free_contig_range(end, outer_end - end);
7165 undo_isolate_page_range(pfn_max_align_down(start),
7166 pfn_max_align_up(end), migratetype);
7170 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7172 unsigned int count = 0;
7174 for (; nr_pages--; pfn++) {
7175 struct page *page = pfn_to_page(pfn);
7177 count += page_count(page) != 1;
7180 WARN(count != 0, "%d pages are still in use!\n", count);
7184 #ifdef CONFIG_MEMORY_HOTPLUG
7186 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7187 * page high values need to be recalulated.
7189 void __meminit zone_pcp_update(struct zone *zone)
7192 mutex_lock(&pcp_batch_high_lock);
7193 for_each_possible_cpu(cpu)
7194 pageset_set_high_and_batch(zone,
7195 per_cpu_ptr(zone->pageset, cpu));
7196 mutex_unlock(&pcp_batch_high_lock);
7200 void zone_pcp_reset(struct zone *zone)
7202 unsigned long flags;
7204 struct per_cpu_pageset *pset;
7206 /* avoid races with drain_pages() */
7207 local_irq_save(flags);
7208 if (zone->pageset != &boot_pageset) {
7209 for_each_online_cpu(cpu) {
7210 pset = per_cpu_ptr(zone->pageset, cpu);
7211 drain_zonestat(zone, pset);
7213 free_percpu(zone->pageset);
7214 zone->pageset = &boot_pageset;
7216 local_irq_restore(flags);
7219 #ifdef CONFIG_MEMORY_HOTREMOVE
7221 * All pages in the range must be in a single zone and isolated
7222 * before calling this.
7225 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7229 unsigned int order, i;
7231 unsigned long flags;
7232 /* find the first valid pfn */
7233 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7238 zone = page_zone(pfn_to_page(pfn));
7239 spin_lock_irqsave(&zone->lock, flags);
7241 while (pfn < end_pfn) {
7242 if (!pfn_valid(pfn)) {
7246 page = pfn_to_page(pfn);
7248 * The HWPoisoned page may be not in buddy system, and
7249 * page_count() is not 0.
7251 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7253 SetPageReserved(page);
7257 BUG_ON(page_count(page));
7258 BUG_ON(!PageBuddy(page));
7259 order = page_order(page);
7260 #ifdef CONFIG_DEBUG_VM
7261 pr_info("remove from free list %lx %d %lx\n",
7262 pfn, 1 << order, end_pfn);
7264 list_del(&page->lru);
7265 rmv_page_order(page);
7266 zone->free_area[order].nr_free--;
7267 for (i = 0; i < (1 << order); i++)
7268 SetPageReserved((page+i));
7269 pfn += (1 << order);
7271 spin_unlock_irqrestore(&zone->lock, flags);
7275 bool is_free_buddy_page(struct page *page)
7277 struct zone *zone = page_zone(page);
7278 unsigned long pfn = page_to_pfn(page);
7279 unsigned long flags;
7282 spin_lock_irqsave(&zone->lock, flags);
7283 for (order = 0; order < MAX_ORDER; order++) {
7284 struct page *page_head = page - (pfn & ((1 << order) - 1));
7286 if (PageBuddy(page_head) && page_order(page_head) >= order)
7289 spin_unlock_irqrestore(&zone->lock, flags);
7291 return order < MAX_ORDER;