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;
834 bool isolated_pageblocks;
836 spin_lock(&zone->lock);
837 isolated_pageblocks = has_isolate_pageblock(zone);
838 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
840 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
844 struct list_head *list;
847 * Remove pages from lists in a round-robin fashion. A
848 * batch_free count is maintained that is incremented when an
849 * empty list is encountered. This is so more pages are freed
850 * off fuller lists instead of spinning excessively around empty
855 if (++migratetype == MIGRATE_PCPTYPES)
857 list = &pcp->lists[migratetype];
858 } while (list_empty(list));
860 /* This is the only non-empty list. Free them all. */
861 if (batch_free == MIGRATE_PCPTYPES)
862 batch_free = to_free;
865 int mt; /* migratetype of the to-be-freed page */
867 page = list_last_entry(list, struct page, lru);
868 /* must delete as __free_one_page list manipulates */
869 list_del(&page->lru);
871 mt = get_pcppage_migratetype(page);
872 /* MIGRATE_ISOLATE page should not go to pcplists */
873 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
874 /* Pageblock could have been isolated meanwhile */
875 if (unlikely(isolated_pageblocks))
876 mt = get_pageblock_migratetype(page);
878 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
879 trace_mm_page_pcpu_drain(page, 0, mt);
880 } while (--to_free && --batch_free && !list_empty(list));
882 spin_unlock(&zone->lock);
885 static void free_one_page(struct zone *zone,
886 struct page *page, unsigned long pfn,
890 unsigned long nr_scanned;
891 spin_lock(&zone->lock);
892 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
894 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
896 if (unlikely(has_isolate_pageblock(zone) ||
897 is_migrate_isolate(migratetype))) {
898 migratetype = get_pfnblock_migratetype(page, pfn);
900 __free_one_page(page, pfn, zone, order, migratetype);
901 spin_unlock(&zone->lock);
904 static int free_tail_pages_check(struct page *head_page, struct page *page)
909 * We rely page->lru.next never has bit 0 set, unless the page
910 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
912 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
914 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
918 switch (page - head_page) {
920 /* the first tail page: ->mapping is compound_mapcount() */
921 if (unlikely(compound_mapcount(page))) {
922 bad_page(page, "nonzero compound_mapcount", 0);
928 * the second tail page: ->mapping is
929 * page_deferred_list().next -- ignore value.
933 if (page->mapping != TAIL_MAPPING) {
934 bad_page(page, "corrupted mapping in tail page", 0);
939 if (unlikely(!PageTail(page))) {
940 bad_page(page, "PageTail not set", 0);
943 if (unlikely(compound_head(page) != head_page)) {
944 bad_page(page, "compound_head not consistent", 0);
949 page->mapping = NULL;
950 clear_compound_head(page);
954 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
955 unsigned long zone, int nid)
957 set_page_links(page, zone, nid, pfn);
958 init_page_count(page);
959 page_mapcount_reset(page);
960 page_cpupid_reset_last(page);
962 INIT_LIST_HEAD(&page->lru);
963 #ifdef WANT_PAGE_VIRTUAL
964 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
965 if (!is_highmem_idx(zone))
966 set_page_address(page, __va(pfn << PAGE_SHIFT));
970 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
973 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
976 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
977 static void init_reserved_page(unsigned long pfn)
982 if (!early_page_uninitialised(pfn))
985 nid = early_pfn_to_nid(pfn);
986 pgdat = NODE_DATA(nid);
988 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
989 struct zone *zone = &pgdat->node_zones[zid];
991 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
994 __init_single_pfn(pfn, zid, nid);
997 static inline void init_reserved_page(unsigned long pfn)
1000 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1003 * Initialised pages do not have PageReserved set. This function is
1004 * called for each range allocated by the bootmem allocator and
1005 * marks the pages PageReserved. The remaining valid pages are later
1006 * sent to the buddy page allocator.
1008 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
1010 unsigned long start_pfn = PFN_DOWN(start);
1011 unsigned long end_pfn = PFN_UP(end);
1013 for (; start_pfn < end_pfn; start_pfn++) {
1014 if (pfn_valid(start_pfn)) {
1015 struct page *page = pfn_to_page(start_pfn);
1017 init_reserved_page(start_pfn);
1019 /* Avoid false-positive PageTail() */
1020 INIT_LIST_HEAD(&page->lru);
1022 SetPageReserved(page);
1027 static bool free_pages_prepare(struct page *page, unsigned int order)
1031 VM_BUG_ON_PAGE(PageTail(page), page);
1033 trace_mm_page_free(page, order);
1034 kmemcheck_free_shadow(page, order);
1035 kasan_free_pages(page, order);
1038 * Check tail pages before head page information is cleared to
1039 * avoid checking PageCompound for order-0 pages.
1041 if (unlikely(order)) {
1042 bool compound = PageCompound(page);
1045 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1047 for (i = 1; i < (1 << order); i++) {
1049 bad += free_tail_pages_check(page, page + i);
1050 bad += free_pages_check(page + i);
1053 if (PageAnonHead(page))
1054 page->mapping = NULL;
1055 bad += free_pages_check(page);
1059 reset_page_owner(page, order);
1061 if (!PageHighMem(page)) {
1062 debug_check_no_locks_freed(page_address(page),
1063 PAGE_SIZE << order);
1064 debug_check_no_obj_freed(page_address(page),
1065 PAGE_SIZE << order);
1067 arch_free_page(page, order);
1068 kernel_poison_pages(page, 1 << order, 0);
1069 kernel_map_pages(page, 1 << order, 0);
1074 static void __free_pages_ok(struct page *page, unsigned int order)
1076 unsigned long flags;
1078 unsigned long pfn = page_to_pfn(page);
1080 if (!free_pages_prepare(page, order))
1083 migratetype = get_pfnblock_migratetype(page, pfn);
1084 local_irq_save(flags);
1085 __count_vm_events(PGFREE, 1 << order);
1086 free_one_page(page_zone(page), page, pfn, order, migratetype);
1087 local_irq_restore(flags);
1090 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1092 unsigned int nr_pages = 1 << order;
1093 struct page *p = page;
1097 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1099 __ClearPageReserved(p);
1100 set_page_count(p, 0);
1102 __ClearPageReserved(p);
1103 set_page_count(p, 0);
1105 page_zone(page)->managed_pages += nr_pages;
1106 set_page_refcounted(page);
1107 __free_pages(page, order);
1110 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1111 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1113 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1115 int __meminit early_pfn_to_nid(unsigned long pfn)
1117 static DEFINE_SPINLOCK(early_pfn_lock);
1120 spin_lock(&early_pfn_lock);
1121 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1124 spin_unlock(&early_pfn_lock);
1130 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1131 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1132 struct mminit_pfnnid_cache *state)
1136 nid = __early_pfn_to_nid(pfn, state);
1137 if (nid >= 0 && nid != node)
1142 /* Only safe to use early in boot when initialisation is single-threaded */
1143 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1145 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1150 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1154 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1155 struct mminit_pfnnid_cache *state)
1162 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1165 if (early_page_uninitialised(pfn))
1167 return __free_pages_boot_core(page, order);
1171 * Check that the whole (or subset of) a pageblock given by the interval of
1172 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1173 * with the migration of free compaction scanner. The scanners then need to
1174 * use only pfn_valid_within() check for arches that allow holes within
1177 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1179 * It's possible on some configurations to have a setup like node0 node1 node0
1180 * i.e. it's possible that all pages within a zones range of pages do not
1181 * belong to a single zone. We assume that a border between node0 and node1
1182 * can occur within a single pageblock, but not a node0 node1 node0
1183 * interleaving within a single pageblock. It is therefore sufficient to check
1184 * the first and last page of a pageblock and avoid checking each individual
1185 * page in a pageblock.
1187 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1188 unsigned long end_pfn, struct zone *zone)
1190 struct page *start_page;
1191 struct page *end_page;
1193 /* end_pfn is one past the range we are checking */
1196 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1199 start_page = pfn_to_page(start_pfn);
1201 if (page_zone(start_page) != zone)
1204 end_page = pfn_to_page(end_pfn);
1206 /* This gives a shorter code than deriving page_zone(end_page) */
1207 if (page_zone_id(start_page) != page_zone_id(end_page))
1213 void set_zone_contiguous(struct zone *zone)
1215 unsigned long block_start_pfn = zone->zone_start_pfn;
1216 unsigned long block_end_pfn;
1218 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1219 for (; block_start_pfn < zone_end_pfn(zone);
1220 block_start_pfn = block_end_pfn,
1221 block_end_pfn += pageblock_nr_pages) {
1223 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1225 if (!__pageblock_pfn_to_page(block_start_pfn,
1226 block_end_pfn, zone))
1230 /* We confirm that there is no hole */
1231 zone->contiguous = true;
1234 void clear_zone_contiguous(struct zone *zone)
1236 zone->contiguous = false;
1239 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1240 static void __init deferred_free_range(struct page *page,
1241 unsigned long pfn, int nr_pages)
1248 /* Free a large naturally-aligned chunk if possible */
1249 if (nr_pages == MAX_ORDER_NR_PAGES &&
1250 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1251 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1252 __free_pages_boot_core(page, MAX_ORDER-1);
1256 for (i = 0; i < nr_pages; i++, page++)
1257 __free_pages_boot_core(page, 0);
1260 /* Completion tracking for deferred_init_memmap() threads */
1261 static atomic_t pgdat_init_n_undone __initdata;
1262 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1264 static inline void __init pgdat_init_report_one_done(void)
1266 if (atomic_dec_and_test(&pgdat_init_n_undone))
1267 complete(&pgdat_init_all_done_comp);
1270 /* Initialise remaining memory on a node */
1271 static int __init deferred_init_memmap(void *data)
1273 pg_data_t *pgdat = data;
1274 int nid = pgdat->node_id;
1275 struct mminit_pfnnid_cache nid_init_state = { };
1276 unsigned long start = jiffies;
1277 unsigned long nr_pages = 0;
1278 unsigned long walk_start, walk_end;
1281 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1282 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1284 if (first_init_pfn == ULONG_MAX) {
1285 pgdat_init_report_one_done();
1289 /* Bind memory initialisation thread to a local node if possible */
1290 if (!cpumask_empty(cpumask))
1291 set_cpus_allowed_ptr(current, cpumask);
1293 /* Sanity check boundaries */
1294 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1295 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1296 pgdat->first_deferred_pfn = ULONG_MAX;
1298 /* Only the highest zone is deferred so find it */
1299 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1300 zone = pgdat->node_zones + zid;
1301 if (first_init_pfn < zone_end_pfn(zone))
1305 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1306 unsigned long pfn, end_pfn;
1307 struct page *page = NULL;
1308 struct page *free_base_page = NULL;
1309 unsigned long free_base_pfn = 0;
1312 end_pfn = min(walk_end, zone_end_pfn(zone));
1313 pfn = first_init_pfn;
1314 if (pfn < walk_start)
1316 if (pfn < zone->zone_start_pfn)
1317 pfn = zone->zone_start_pfn;
1319 for (; pfn < end_pfn; pfn++) {
1320 if (!pfn_valid_within(pfn))
1324 * Ensure pfn_valid is checked every
1325 * MAX_ORDER_NR_PAGES for memory holes
1327 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1328 if (!pfn_valid(pfn)) {
1334 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1339 /* Minimise pfn page lookups and scheduler checks */
1340 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1343 nr_pages += nr_to_free;
1344 deferred_free_range(free_base_page,
1345 free_base_pfn, nr_to_free);
1346 free_base_page = NULL;
1347 free_base_pfn = nr_to_free = 0;
1349 page = pfn_to_page(pfn);
1354 VM_BUG_ON(page_zone(page) != zone);
1358 __init_single_page(page, pfn, zid, nid);
1359 if (!free_base_page) {
1360 free_base_page = page;
1361 free_base_pfn = pfn;
1366 /* Where possible, batch up pages for a single free */
1369 /* Free the current block of pages to allocator */
1370 nr_pages += nr_to_free;
1371 deferred_free_range(free_base_page, free_base_pfn,
1373 free_base_page = NULL;
1374 free_base_pfn = nr_to_free = 0;
1377 first_init_pfn = max(end_pfn, first_init_pfn);
1380 /* Sanity check that the next zone really is unpopulated */
1381 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1383 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1384 jiffies_to_msecs(jiffies - start));
1386 pgdat_init_report_one_done();
1389 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1391 void __init page_alloc_init_late(void)
1395 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1398 /* There will be num_node_state(N_MEMORY) threads */
1399 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1400 for_each_node_state(nid, N_MEMORY) {
1401 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1404 /* Block until all are initialised */
1405 wait_for_completion(&pgdat_init_all_done_comp);
1407 /* Reinit limits that are based on free pages after the kernel is up */
1408 files_maxfiles_init();
1411 for_each_populated_zone(zone)
1412 set_zone_contiguous(zone);
1416 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1417 void __init init_cma_reserved_pageblock(struct page *page)
1419 unsigned i = pageblock_nr_pages;
1420 struct page *p = page;
1423 __ClearPageReserved(p);
1424 set_page_count(p, 0);
1427 set_pageblock_migratetype(page, MIGRATE_CMA);
1429 if (pageblock_order >= MAX_ORDER) {
1430 i = pageblock_nr_pages;
1433 set_page_refcounted(p);
1434 __free_pages(p, MAX_ORDER - 1);
1435 p += MAX_ORDER_NR_PAGES;
1436 } while (i -= MAX_ORDER_NR_PAGES);
1438 set_page_refcounted(page);
1439 __free_pages(page, pageblock_order);
1442 adjust_managed_page_count(page, pageblock_nr_pages);
1447 * The order of subdivision here is critical for the IO subsystem.
1448 * Please do not alter this order without good reasons and regression
1449 * testing. Specifically, as large blocks of memory are subdivided,
1450 * the order in which smaller blocks are delivered depends on the order
1451 * they're subdivided in this function. This is the primary factor
1452 * influencing the order in which pages are delivered to the IO
1453 * subsystem according to empirical testing, and this is also justified
1454 * by considering the behavior of a buddy system containing a single
1455 * large block of memory acted on by a series of small allocations.
1456 * This behavior is a critical factor in sglist merging's success.
1460 static inline void expand(struct zone *zone, struct page *page,
1461 int low, int high, struct free_area *area,
1464 unsigned long size = 1 << high;
1466 while (high > low) {
1470 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1472 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1473 debug_guardpage_enabled() &&
1474 high < debug_guardpage_minorder()) {
1476 * Mark as guard pages (or page), that will allow to
1477 * merge back to allocator when buddy will be freed.
1478 * Corresponding page table entries will not be touched,
1479 * pages will stay not present in virtual address space
1481 set_page_guard(zone, &page[size], high, migratetype);
1484 list_add(&page[size].lru, &area->free_list[migratetype]);
1486 set_page_order(&page[size], high);
1491 * This page is about to be returned from the page allocator
1493 static inline int check_new_page(struct page *page)
1495 const char *bad_reason = NULL;
1496 unsigned long bad_flags = 0;
1498 if (unlikely(atomic_read(&page->_mapcount) != -1))
1499 bad_reason = "nonzero mapcount";
1500 if (unlikely(page->mapping != NULL))
1501 bad_reason = "non-NULL mapping";
1502 if (unlikely(page_ref_count(page) != 0))
1503 bad_reason = "nonzero _count";
1504 if (unlikely(page->flags & __PG_HWPOISON)) {
1505 bad_reason = "HWPoisoned (hardware-corrupted)";
1506 bad_flags = __PG_HWPOISON;
1508 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1509 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1510 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1513 if (unlikely(page->mem_cgroup))
1514 bad_reason = "page still charged to cgroup";
1516 if (unlikely(bad_reason)) {
1517 bad_page(page, bad_reason, bad_flags);
1523 static inline bool free_pages_prezeroed(bool poisoned)
1525 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1526 page_poisoning_enabled() && poisoned;
1529 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1530 unsigned int alloc_flags)
1533 bool poisoned = true;
1535 for (i = 0; i < (1 << order); i++) {
1536 struct page *p = page + i;
1537 if (unlikely(check_new_page(p)))
1540 poisoned &= page_is_poisoned(p);
1543 set_page_private(page, 0);
1544 set_page_refcounted(page);
1546 arch_alloc_page(page, order);
1547 kernel_map_pages(page, 1 << order, 1);
1548 kernel_poison_pages(page, 1 << order, 1);
1549 kasan_alloc_pages(page, order);
1551 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1552 for (i = 0; i < (1 << order); i++)
1553 clear_highpage(page + i);
1555 if (order && (gfp_flags & __GFP_COMP))
1556 prep_compound_page(page, order);
1558 set_page_owner(page, order, gfp_flags);
1561 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1562 * allocate the page. The expectation is that the caller is taking
1563 * steps that will free more memory. The caller should avoid the page
1564 * being used for !PFMEMALLOC purposes.
1566 if (alloc_flags & ALLOC_NO_WATERMARKS)
1567 set_page_pfmemalloc(page);
1569 clear_page_pfmemalloc(page);
1575 * Go through the free lists for the given migratetype and remove
1576 * the smallest available page from the freelists
1579 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1582 unsigned int current_order;
1583 struct free_area *area;
1586 /* Find a page of the appropriate size in the preferred list */
1587 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1588 area = &(zone->free_area[current_order]);
1589 page = list_first_entry_or_null(&area->free_list[migratetype],
1593 list_del(&page->lru);
1594 rmv_page_order(page);
1596 expand(zone, page, order, current_order, area, migratetype);
1597 set_pcppage_migratetype(page, migratetype);
1606 * This array describes the order lists are fallen back to when
1607 * the free lists for the desirable migrate type are depleted
1609 static int fallbacks[MIGRATE_TYPES][4] = {
1610 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1611 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1612 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1614 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1616 #ifdef CONFIG_MEMORY_ISOLATION
1617 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1622 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1625 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1628 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1629 unsigned int order) { return NULL; }
1633 * Move the free pages in a range to the free lists of the requested type.
1634 * Note that start_page and end_pages are not aligned on a pageblock
1635 * boundary. If alignment is required, use move_freepages_block()
1637 int move_freepages(struct zone *zone,
1638 struct page *start_page, struct page *end_page,
1643 int pages_moved = 0;
1645 #ifndef CONFIG_HOLES_IN_ZONE
1647 * page_zone is not safe to call in this context when
1648 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1649 * anyway as we check zone boundaries in move_freepages_block().
1650 * Remove at a later date when no bug reports exist related to
1651 * grouping pages by mobility
1653 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1656 for (page = start_page; page <= end_page;) {
1657 /* Make sure we are not inadvertently changing nodes */
1658 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1660 if (!pfn_valid_within(page_to_pfn(page))) {
1665 if (!PageBuddy(page)) {
1670 order = page_order(page);
1671 list_move(&page->lru,
1672 &zone->free_area[order].free_list[migratetype]);
1674 pages_moved += 1 << order;
1680 int move_freepages_block(struct zone *zone, struct page *page,
1683 unsigned long start_pfn, end_pfn;
1684 struct page *start_page, *end_page;
1686 start_pfn = page_to_pfn(page);
1687 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1688 start_page = pfn_to_page(start_pfn);
1689 end_page = start_page + pageblock_nr_pages - 1;
1690 end_pfn = start_pfn + pageblock_nr_pages - 1;
1692 /* Do not cross zone boundaries */
1693 if (!zone_spans_pfn(zone, start_pfn))
1695 if (!zone_spans_pfn(zone, end_pfn))
1698 return move_freepages(zone, start_page, end_page, migratetype);
1701 static void change_pageblock_range(struct page *pageblock_page,
1702 int start_order, int migratetype)
1704 int nr_pageblocks = 1 << (start_order - pageblock_order);
1706 while (nr_pageblocks--) {
1707 set_pageblock_migratetype(pageblock_page, migratetype);
1708 pageblock_page += pageblock_nr_pages;
1713 * When we are falling back to another migratetype during allocation, try to
1714 * steal extra free pages from the same pageblocks to satisfy further
1715 * allocations, instead of polluting multiple pageblocks.
1717 * If we are stealing a relatively large buddy page, it is likely there will
1718 * be more free pages in the pageblock, so try to steal them all. For
1719 * reclaimable and unmovable allocations, we steal regardless of page size,
1720 * as fragmentation caused by those allocations polluting movable pageblocks
1721 * is worse than movable allocations stealing from unmovable and reclaimable
1724 static bool can_steal_fallback(unsigned int order, int start_mt)
1727 * Leaving this order check is intended, although there is
1728 * relaxed order check in next check. The reason is that
1729 * we can actually steal whole pageblock if this condition met,
1730 * but, below check doesn't guarantee it and that is just heuristic
1731 * so could be changed anytime.
1733 if (order >= pageblock_order)
1736 if (order >= pageblock_order / 2 ||
1737 start_mt == MIGRATE_RECLAIMABLE ||
1738 start_mt == MIGRATE_UNMOVABLE ||
1739 page_group_by_mobility_disabled)
1746 * This function implements actual steal behaviour. If order is large enough,
1747 * we can steal whole pageblock. If not, we first move freepages in this
1748 * pageblock and check whether half of pages are moved or not. If half of
1749 * pages are moved, we can change migratetype of pageblock and permanently
1750 * use it's pages as requested migratetype in the future.
1752 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1755 unsigned int current_order = page_order(page);
1758 /* Take ownership for orders >= pageblock_order */
1759 if (current_order >= pageblock_order) {
1760 change_pageblock_range(page, current_order, start_type);
1764 pages = move_freepages_block(zone, page, start_type);
1766 /* Claim the whole block if over half of it is free */
1767 if (pages >= (1 << (pageblock_order-1)) ||
1768 page_group_by_mobility_disabled)
1769 set_pageblock_migratetype(page, start_type);
1773 * Check whether there is a suitable fallback freepage with requested order.
1774 * If only_stealable is true, this function returns fallback_mt only if
1775 * we can steal other freepages all together. This would help to reduce
1776 * fragmentation due to mixed migratetype pages in one pageblock.
1778 int find_suitable_fallback(struct free_area *area, unsigned int order,
1779 int migratetype, bool only_stealable, bool *can_steal)
1784 if (area->nr_free == 0)
1789 fallback_mt = fallbacks[migratetype][i];
1790 if (fallback_mt == MIGRATE_TYPES)
1793 if (list_empty(&area->free_list[fallback_mt]))
1796 if (can_steal_fallback(order, migratetype))
1799 if (!only_stealable)
1810 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1811 * there are no empty page blocks that contain a page with a suitable order
1813 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
1814 unsigned int alloc_order)
1817 unsigned long max_managed, flags;
1820 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1821 * Check is race-prone but harmless.
1823 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
1824 if (zone->nr_reserved_highatomic >= max_managed)
1827 spin_lock_irqsave(&zone->lock, flags);
1829 /* Recheck the nr_reserved_highatomic limit under the lock */
1830 if (zone->nr_reserved_highatomic >= max_managed)
1834 mt = get_pageblock_migratetype(page);
1835 if (mt != MIGRATE_HIGHATOMIC &&
1836 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
1837 zone->nr_reserved_highatomic += pageblock_nr_pages;
1838 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
1839 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
1843 spin_unlock_irqrestore(&zone->lock, flags);
1847 * Used when an allocation is about to fail under memory pressure. This
1848 * potentially hurts the reliability of high-order allocations when under
1849 * intense memory pressure but failed atomic allocations should be easier
1850 * to recover from than an OOM.
1852 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
1854 struct zonelist *zonelist = ac->zonelist;
1855 unsigned long flags;
1861 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
1863 /* Preserve at least one pageblock */
1864 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
1867 spin_lock_irqsave(&zone->lock, flags);
1868 for (order = 0; order < MAX_ORDER; order++) {
1869 struct free_area *area = &(zone->free_area[order]);
1871 page = list_first_entry_or_null(
1872 &area->free_list[MIGRATE_HIGHATOMIC],
1878 * It should never happen but changes to locking could
1879 * inadvertently allow a per-cpu drain to add pages
1880 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1881 * and watch for underflows.
1883 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
1884 zone->nr_reserved_highatomic);
1887 * Convert to ac->migratetype and avoid the normal
1888 * pageblock stealing heuristics. Minimally, the caller
1889 * is doing the work and needs the pages. More
1890 * importantly, if the block was always converted to
1891 * MIGRATE_UNMOVABLE or another type then the number
1892 * of pageblocks that cannot be completely freed
1895 set_pageblock_migratetype(page, ac->migratetype);
1896 move_freepages_block(zone, page, ac->migratetype);
1897 spin_unlock_irqrestore(&zone->lock, flags);
1900 spin_unlock_irqrestore(&zone->lock, flags);
1904 /* Remove an element from the buddy allocator from the fallback list */
1905 static inline struct page *
1906 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1908 struct free_area *area;
1909 unsigned int current_order;
1914 /* Find the largest possible block of pages in the other list */
1915 for (current_order = MAX_ORDER-1;
1916 current_order >= order && current_order <= MAX_ORDER-1;
1918 area = &(zone->free_area[current_order]);
1919 fallback_mt = find_suitable_fallback(area, current_order,
1920 start_migratetype, false, &can_steal);
1921 if (fallback_mt == -1)
1924 page = list_first_entry(&area->free_list[fallback_mt],
1927 steal_suitable_fallback(zone, page, start_migratetype);
1929 /* Remove the page from the freelists */
1931 list_del(&page->lru);
1932 rmv_page_order(page);
1934 expand(zone, page, order, current_order, area,
1937 * The pcppage_migratetype may differ from pageblock's
1938 * migratetype depending on the decisions in
1939 * find_suitable_fallback(). This is OK as long as it does not
1940 * differ for MIGRATE_CMA pageblocks. Those can be used as
1941 * fallback only via special __rmqueue_cma_fallback() function
1943 set_pcppage_migratetype(page, start_migratetype);
1945 trace_mm_page_alloc_extfrag(page, order, current_order,
1946 start_migratetype, fallback_mt);
1955 * Do the hard work of removing an element from the buddy allocator.
1956 * Call me with the zone->lock already held.
1958 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1963 page = __rmqueue_smallest(zone, order, migratetype);
1964 if (unlikely(!page)) {
1965 if (migratetype == MIGRATE_MOVABLE)
1966 page = __rmqueue_cma_fallback(zone, order);
1969 page = __rmqueue_fallback(zone, order, migratetype);
1972 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1977 * Obtain a specified number of elements from the buddy allocator, all under
1978 * a single hold of the lock, for efficiency. Add them to the supplied list.
1979 * Returns the number of new pages which were placed at *list.
1981 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1982 unsigned long count, struct list_head *list,
1983 int migratetype, bool cold)
1987 spin_lock(&zone->lock);
1988 for (i = 0; i < count; ++i) {
1989 struct page *page = __rmqueue(zone, order, migratetype);
1990 if (unlikely(page == NULL))
1994 * Split buddy pages returned by expand() are received here
1995 * in physical page order. The page is added to the callers and
1996 * list and the list head then moves forward. From the callers
1997 * perspective, the linked list is ordered by page number in
1998 * some conditions. This is useful for IO devices that can
1999 * merge IO requests if the physical pages are ordered
2003 list_add(&page->lru, list);
2005 list_add_tail(&page->lru, list);
2007 if (is_migrate_cma(get_pcppage_migratetype(page)))
2008 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2011 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2012 spin_unlock(&zone->lock);
2018 * Called from the vmstat counter updater to drain pagesets of this
2019 * currently executing processor on remote nodes after they have
2022 * Note that this function must be called with the thread pinned to
2023 * a single processor.
2025 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2027 unsigned long flags;
2028 int to_drain, batch;
2030 local_irq_save(flags);
2031 batch = READ_ONCE(pcp->batch);
2032 to_drain = min(pcp->count, batch);
2034 free_pcppages_bulk(zone, to_drain, pcp);
2035 pcp->count -= to_drain;
2037 local_irq_restore(flags);
2042 * Drain pcplists of the indicated processor and zone.
2044 * The processor must either be the current processor and the
2045 * thread pinned to the current processor or a processor that
2048 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2050 unsigned long flags;
2051 struct per_cpu_pageset *pset;
2052 struct per_cpu_pages *pcp;
2054 local_irq_save(flags);
2055 pset = per_cpu_ptr(zone->pageset, cpu);
2059 free_pcppages_bulk(zone, pcp->count, pcp);
2062 local_irq_restore(flags);
2066 * Drain pcplists of all zones on the indicated processor.
2068 * The processor must either be the current processor and the
2069 * thread pinned to the current processor or a processor that
2072 static void drain_pages(unsigned int cpu)
2076 for_each_populated_zone(zone) {
2077 drain_pages_zone(cpu, zone);
2082 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2084 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2085 * the single zone's pages.
2087 void drain_local_pages(struct zone *zone)
2089 int cpu = smp_processor_id();
2092 drain_pages_zone(cpu, zone);
2098 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2100 * When zone parameter is non-NULL, spill just the single zone's pages.
2102 * Note that this code is protected against sending an IPI to an offline
2103 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2104 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2105 * nothing keeps CPUs from showing up after we populated the cpumask and
2106 * before the call to on_each_cpu_mask().
2108 void drain_all_pages(struct zone *zone)
2113 * Allocate in the BSS so we wont require allocation in
2114 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2116 static cpumask_t cpus_with_pcps;
2119 * We don't care about racing with CPU hotplug event
2120 * as offline notification will cause the notified
2121 * cpu to drain that CPU pcps and on_each_cpu_mask
2122 * disables preemption as part of its processing
2124 for_each_online_cpu(cpu) {
2125 struct per_cpu_pageset *pcp;
2127 bool has_pcps = false;
2130 pcp = per_cpu_ptr(zone->pageset, cpu);
2134 for_each_populated_zone(z) {
2135 pcp = per_cpu_ptr(z->pageset, cpu);
2136 if (pcp->pcp.count) {
2144 cpumask_set_cpu(cpu, &cpus_with_pcps);
2146 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2148 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2152 #ifdef CONFIG_HIBERNATION
2154 void mark_free_pages(struct zone *zone)
2156 unsigned long pfn, max_zone_pfn;
2157 unsigned long flags;
2158 unsigned int order, t;
2161 if (zone_is_empty(zone))
2164 spin_lock_irqsave(&zone->lock, flags);
2166 max_zone_pfn = zone_end_pfn(zone);
2167 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2168 if (pfn_valid(pfn)) {
2169 page = pfn_to_page(pfn);
2171 if (page_zone(page) != zone)
2174 if (!swsusp_page_is_forbidden(page))
2175 swsusp_unset_page_free(page);
2178 for_each_migratetype_order(order, t) {
2179 list_for_each_entry(page,
2180 &zone->free_area[order].free_list[t], lru) {
2183 pfn = page_to_pfn(page);
2184 for (i = 0; i < (1UL << order); i++)
2185 swsusp_set_page_free(pfn_to_page(pfn + i));
2188 spin_unlock_irqrestore(&zone->lock, flags);
2190 #endif /* CONFIG_PM */
2193 * Free a 0-order page
2194 * cold == true ? free a cold page : free a hot page
2196 void free_hot_cold_page(struct page *page, bool cold)
2198 struct zone *zone = page_zone(page);
2199 struct per_cpu_pages *pcp;
2200 unsigned long flags;
2201 unsigned long pfn = page_to_pfn(page);
2204 if (!free_pages_prepare(page, 0))
2207 migratetype = get_pfnblock_migratetype(page, pfn);
2208 set_pcppage_migratetype(page, migratetype);
2209 local_irq_save(flags);
2210 __count_vm_event(PGFREE);
2213 * We only track unmovable, reclaimable and movable on pcp lists.
2214 * Free ISOLATE pages back to the allocator because they are being
2215 * offlined but treat RESERVE as movable pages so we can get those
2216 * areas back if necessary. Otherwise, we may have to free
2217 * excessively into the page allocator
2219 if (migratetype >= MIGRATE_PCPTYPES) {
2220 if (unlikely(is_migrate_isolate(migratetype))) {
2221 free_one_page(zone, page, pfn, 0, migratetype);
2224 migratetype = MIGRATE_MOVABLE;
2227 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2229 list_add(&page->lru, &pcp->lists[migratetype]);
2231 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2233 if (pcp->count >= pcp->high) {
2234 unsigned long batch = READ_ONCE(pcp->batch);
2235 free_pcppages_bulk(zone, batch, pcp);
2236 pcp->count -= batch;
2240 local_irq_restore(flags);
2244 * Free a list of 0-order pages
2246 void free_hot_cold_page_list(struct list_head *list, bool cold)
2248 struct page *page, *next;
2250 list_for_each_entry_safe(page, next, list, lru) {
2251 trace_mm_page_free_batched(page, cold);
2252 free_hot_cold_page(page, cold);
2257 * split_page takes a non-compound higher-order page, and splits it into
2258 * n (1<<order) sub-pages: page[0..n]
2259 * Each sub-page must be freed individually.
2261 * Note: this is probably too low level an operation for use in drivers.
2262 * Please consult with lkml before using this in your driver.
2264 void split_page(struct page *page, unsigned int order)
2269 VM_BUG_ON_PAGE(PageCompound(page), page);
2270 VM_BUG_ON_PAGE(!page_count(page), page);
2272 #ifdef CONFIG_KMEMCHECK
2274 * Split shadow pages too, because free(page[0]) would
2275 * otherwise free the whole shadow.
2277 if (kmemcheck_page_is_tracked(page))
2278 split_page(virt_to_page(page[0].shadow), order);
2281 gfp_mask = get_page_owner_gfp(page);
2282 set_page_owner(page, 0, gfp_mask);
2283 for (i = 1; i < (1 << order); i++) {
2284 set_page_refcounted(page + i);
2285 set_page_owner(page + i, 0, gfp_mask);
2288 EXPORT_SYMBOL_GPL(split_page);
2290 int __isolate_free_page(struct page *page, unsigned int order)
2292 unsigned long watermark;
2296 BUG_ON(!PageBuddy(page));
2298 zone = page_zone(page);
2299 mt = get_pageblock_migratetype(page);
2301 if (!is_migrate_isolate(mt)) {
2302 /* Obey watermarks as if the page was being allocated */
2303 watermark = low_wmark_pages(zone) + (1 << order);
2304 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2307 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2310 /* Remove page from free list */
2311 list_del(&page->lru);
2312 zone->free_area[order].nr_free--;
2313 rmv_page_order(page);
2315 set_page_owner(page, order, __GFP_MOVABLE);
2317 /* Set the pageblock if the isolated page is at least a pageblock */
2318 if (order >= pageblock_order - 1) {
2319 struct page *endpage = page + (1 << order) - 1;
2320 for (; page < endpage; page += pageblock_nr_pages) {
2321 int mt = get_pageblock_migratetype(page);
2322 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2323 set_pageblock_migratetype(page,
2329 return 1UL << order;
2333 * Similar to split_page except the page is already free. As this is only
2334 * being used for migration, the migratetype of the block also changes.
2335 * As this is called with interrupts disabled, the caller is responsible
2336 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2339 * Note: this is probably too low level an operation for use in drivers.
2340 * Please consult with lkml before using this in your driver.
2342 int split_free_page(struct page *page)
2347 order = page_order(page);
2349 nr_pages = __isolate_free_page(page, order);
2353 /* Split into individual pages */
2354 set_page_refcounted(page);
2355 split_page(page, order);
2360 * Update NUMA hit/miss statistics
2362 * Must be called with interrupts disabled.
2364 * When __GFP_OTHER_NODE is set assume the node of the preferred
2365 * zone is the local node. This is useful for daemons who allocate
2366 * memory on behalf of other processes.
2368 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2372 int local_nid = numa_node_id();
2373 enum zone_stat_item local_stat = NUMA_LOCAL;
2375 if (unlikely(flags & __GFP_OTHER_NODE)) {
2376 local_stat = NUMA_OTHER;
2377 local_nid = preferred_zone->node;
2380 if (z->node == local_nid) {
2381 __inc_zone_state(z, NUMA_HIT);
2382 __inc_zone_state(z, local_stat);
2384 __inc_zone_state(z, NUMA_MISS);
2385 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2391 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2394 struct page *buffered_rmqueue(struct zone *preferred_zone,
2395 struct zone *zone, unsigned int order,
2396 gfp_t gfp_flags, unsigned int alloc_flags,
2399 unsigned long flags;
2401 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2403 if (likely(order == 0)) {
2404 struct per_cpu_pages *pcp;
2405 struct list_head *list;
2407 local_irq_save(flags);
2408 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2409 list = &pcp->lists[migratetype];
2410 if (list_empty(list)) {
2411 pcp->count += rmqueue_bulk(zone, 0,
2414 if (unlikely(list_empty(list)))
2419 page = list_last_entry(list, struct page, lru);
2421 page = list_first_entry(list, struct page, lru);
2423 __dec_zone_state(zone, NR_ALLOC_BATCH);
2424 list_del(&page->lru);
2428 * We most definitely don't want callers attempting to
2429 * allocate greater than order-1 page units with __GFP_NOFAIL.
2431 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2432 spin_lock_irqsave(&zone->lock, flags);
2435 if (alloc_flags & ALLOC_HARDER) {
2436 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2438 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2441 page = __rmqueue(zone, order, migratetype);
2442 spin_unlock(&zone->lock);
2445 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2446 __mod_zone_freepage_state(zone, -(1 << order),
2447 get_pcppage_migratetype(page));
2450 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2451 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2452 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2454 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2455 zone_statistics(preferred_zone, zone, gfp_flags);
2456 local_irq_restore(flags);
2458 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2462 local_irq_restore(flags);
2466 #ifdef CONFIG_FAIL_PAGE_ALLOC
2469 struct fault_attr attr;
2471 bool ignore_gfp_highmem;
2472 bool ignore_gfp_reclaim;
2474 } fail_page_alloc = {
2475 .attr = FAULT_ATTR_INITIALIZER,
2476 .ignore_gfp_reclaim = true,
2477 .ignore_gfp_highmem = true,
2481 static int __init setup_fail_page_alloc(char *str)
2483 return setup_fault_attr(&fail_page_alloc.attr, str);
2485 __setup("fail_page_alloc=", setup_fail_page_alloc);
2487 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2489 if (order < fail_page_alloc.min_order)
2491 if (gfp_mask & __GFP_NOFAIL)
2493 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2495 if (fail_page_alloc.ignore_gfp_reclaim &&
2496 (gfp_mask & __GFP_DIRECT_RECLAIM))
2499 return should_fail(&fail_page_alloc.attr, 1 << order);
2502 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2504 static int __init fail_page_alloc_debugfs(void)
2506 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2509 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2510 &fail_page_alloc.attr);
2512 return PTR_ERR(dir);
2514 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2515 &fail_page_alloc.ignore_gfp_reclaim))
2517 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2518 &fail_page_alloc.ignore_gfp_highmem))
2520 if (!debugfs_create_u32("min-order", mode, dir,
2521 &fail_page_alloc.min_order))
2526 debugfs_remove_recursive(dir);
2531 late_initcall(fail_page_alloc_debugfs);
2533 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2535 #else /* CONFIG_FAIL_PAGE_ALLOC */
2537 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2542 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2545 * Return true if free base pages are above 'mark'. For high-order checks it
2546 * will return true of the order-0 watermark is reached and there is at least
2547 * one free page of a suitable size. Checking now avoids taking the zone lock
2548 * to check in the allocation paths if no pages are free.
2550 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2551 unsigned long mark, int classzone_idx,
2552 unsigned int alloc_flags,
2557 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2559 /* free_pages may go negative - that's OK */
2560 free_pages -= (1 << order) - 1;
2562 if (alloc_flags & ALLOC_HIGH)
2566 * If the caller does not have rights to ALLOC_HARDER then subtract
2567 * the high-atomic reserves. This will over-estimate the size of the
2568 * atomic reserve but it avoids a search.
2570 if (likely(!alloc_harder))
2571 free_pages -= z->nr_reserved_highatomic;
2576 /* If allocation can't use CMA areas don't use free CMA pages */
2577 if (!(alloc_flags & ALLOC_CMA))
2578 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2582 * Check watermarks for an order-0 allocation request. If these
2583 * are not met, then a high-order request also cannot go ahead
2584 * even if a suitable page happened to be free.
2586 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2589 /* If this is an order-0 request then the watermark is fine */
2593 /* For a high-order request, check at least one suitable page is free */
2594 for (o = order; o < MAX_ORDER; o++) {
2595 struct free_area *area = &z->free_area[o];
2604 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2605 if (!list_empty(&area->free_list[mt]))
2610 if ((alloc_flags & ALLOC_CMA) &&
2611 !list_empty(&area->free_list[MIGRATE_CMA])) {
2619 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2620 int classzone_idx, unsigned int alloc_flags)
2622 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2623 zone_page_state(z, NR_FREE_PAGES));
2626 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2627 unsigned long mark, int classzone_idx)
2629 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2631 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2632 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2634 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2639 static bool zone_local(struct zone *local_zone, struct zone *zone)
2641 return local_zone->node == zone->node;
2644 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2646 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2649 #else /* CONFIG_NUMA */
2650 static bool zone_local(struct zone *local_zone, struct zone *zone)
2655 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2659 #endif /* CONFIG_NUMA */
2661 static void reset_alloc_batches(struct zone *preferred_zone)
2663 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2666 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2667 high_wmark_pages(zone) - low_wmark_pages(zone) -
2668 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2669 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2670 } while (zone++ != preferred_zone);
2674 * get_page_from_freelist goes through the zonelist trying to allocate
2677 static struct page *
2678 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2679 const struct alloc_context *ac)
2683 bool fair_skipped = false;
2684 bool apply_fair = (alloc_flags & ALLOC_FAIR);
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, ac->zonelist, ac->high_zoneidx,
2696 if (cpusets_enabled() &&
2697 (alloc_flags & ALLOC_CPUSET) &&
2698 !cpuset_zone_allowed(zone, gfp_mask))
2701 * Distribute pages in proportion to the individual
2702 * zone size to ensure fair page aging. The zone a
2703 * page was allocated in should have no effect on the
2704 * time the page has in memory before being reclaimed.
2707 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2708 fair_skipped = true;
2711 if (!zone_local(ac->preferred_zone, zone)) {
2718 * When allocating a page cache page for writing, we
2719 * want to get it from a zone that is within its dirty
2720 * limit, such that no single zone holds more than its
2721 * proportional share of globally allowed dirty pages.
2722 * The dirty limits take into account the zone's
2723 * lowmem reserves and high watermark so that kswapd
2724 * should be able to balance it without having to
2725 * write pages from its LRU list.
2727 * This may look like it could increase pressure on
2728 * lower zones by failing allocations in higher zones
2729 * before they are full. But the pages that do spill
2730 * over are limited as the lower zones are protected
2731 * by this very same mechanism. It should not become
2732 * a practical burden to them.
2734 * XXX: For now, allow allocations to potentially
2735 * exceed the per-zone dirty limit in the slowpath
2736 * (spread_dirty_pages unset) before going into reclaim,
2737 * which is important when on a NUMA setup the allowed
2738 * zones are together not big enough to reach the
2739 * global limit. The proper fix for these situations
2740 * will require awareness of zones in the
2741 * dirty-throttling and the flusher threads.
2743 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2746 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2747 if (!zone_watermark_ok(zone, order, mark,
2748 ac->classzone_idx, alloc_flags)) {
2751 /* Checked here to keep the fast path fast */
2752 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2753 if (alloc_flags & ALLOC_NO_WATERMARKS)
2756 if (zone_reclaim_mode == 0 ||
2757 !zone_allows_reclaim(ac->preferred_zone, zone))
2760 ret = zone_reclaim(zone, gfp_mask, order);
2762 case ZONE_RECLAIM_NOSCAN:
2765 case ZONE_RECLAIM_FULL:
2766 /* scanned but unreclaimable */
2769 /* did we reclaim enough */
2770 if (zone_watermark_ok(zone, order, mark,
2771 ac->classzone_idx, alloc_flags))
2779 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2780 gfp_mask, alloc_flags, ac->migratetype);
2782 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2786 * If this is a high-order atomic allocation then check
2787 * if the pageblock should be reserved for the future
2789 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2790 reserve_highatomic_pageblock(page, zone, order);
2797 * The first pass makes sure allocations are spread fairly within the
2798 * local node. However, the local node might have free pages left
2799 * after the fairness batches are exhausted, and remote zones haven't
2800 * even been considered yet. Try once more without fairness, and
2801 * include remote zones now, before entering the slowpath and waking
2802 * kswapd: prefer spilling to a remote zone over swapping locally.
2807 fair_skipped = false;
2808 reset_alloc_batches(ac->preferred_zone);
2816 * Large machines with many possible nodes should not always dump per-node
2817 * meminfo in irq context.
2819 static inline bool should_suppress_show_mem(void)
2824 ret = in_interrupt();
2829 static DEFINE_RATELIMIT_STATE(nopage_rs,
2830 DEFAULT_RATELIMIT_INTERVAL,
2831 DEFAULT_RATELIMIT_BURST);
2833 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
2835 unsigned int filter = SHOW_MEM_FILTER_NODES;
2837 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2838 debug_guardpage_minorder() > 0)
2842 * This documents exceptions given to allocations in certain
2843 * contexts that are allowed to allocate outside current's set
2846 if (!(gfp_mask & __GFP_NOMEMALLOC))
2847 if (test_thread_flag(TIF_MEMDIE) ||
2848 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2849 filter &= ~SHOW_MEM_FILTER_NODES;
2850 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
2851 filter &= ~SHOW_MEM_FILTER_NODES;
2854 struct va_format vaf;
2857 va_start(args, fmt);
2862 pr_warn("%pV", &vaf);
2867 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2868 current->comm, order, gfp_mask, &gfp_mask);
2870 if (!should_suppress_show_mem())
2874 static inline struct page *
2875 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2876 const struct alloc_context *ac, unsigned long *did_some_progress)
2878 struct oom_control oc = {
2879 .zonelist = ac->zonelist,
2880 .nodemask = ac->nodemask,
2881 .gfp_mask = gfp_mask,
2886 *did_some_progress = 0;
2889 * Acquire the oom lock. If that fails, somebody else is
2890 * making progress for us.
2892 if (!mutex_trylock(&oom_lock)) {
2893 *did_some_progress = 1;
2894 schedule_timeout_uninterruptible(1);
2899 * Go through the zonelist yet one more time, keep very high watermark
2900 * here, this is only to catch a parallel oom killing, we must fail if
2901 * we're still under heavy pressure.
2903 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2904 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2908 if (!(gfp_mask & __GFP_NOFAIL)) {
2909 /* Coredumps can quickly deplete all memory reserves */
2910 if (current->flags & PF_DUMPCORE)
2912 /* The OOM killer will not help higher order allocs */
2913 if (order > PAGE_ALLOC_COSTLY_ORDER)
2915 /* The OOM killer does not needlessly kill tasks for lowmem */
2916 if (ac->high_zoneidx < ZONE_NORMAL)
2918 if (pm_suspended_storage())
2921 * XXX: GFP_NOFS allocations should rather fail than rely on
2922 * other request to make a forward progress.
2923 * We are in an unfortunate situation where out_of_memory cannot
2924 * do much for this context but let's try it to at least get
2925 * access to memory reserved if the current task is killed (see
2926 * out_of_memory). Once filesystems are ready to handle allocation
2927 * failures more gracefully we should just bail out here.
2930 /* The OOM killer may not free memory on a specific node */
2931 if (gfp_mask & __GFP_THISNODE)
2934 /* Exhausted what can be done so it's blamo time */
2935 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
2936 *did_some_progress = 1;
2938 if (gfp_mask & __GFP_NOFAIL) {
2939 page = get_page_from_freelist(gfp_mask, order,
2940 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
2942 * fallback to ignore cpuset restriction if our nodes
2946 page = get_page_from_freelist(gfp_mask, order,
2947 ALLOC_NO_WATERMARKS, ac);
2951 mutex_unlock(&oom_lock);
2955 #ifdef CONFIG_COMPACTION
2956 /* Try memory compaction for high-order allocations before reclaim */
2957 static struct page *
2958 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2959 unsigned int alloc_flags, const struct alloc_context *ac,
2960 enum migrate_mode mode, int *contended_compaction,
2961 bool *deferred_compaction)
2963 unsigned long compact_result;
2969 current->flags |= PF_MEMALLOC;
2970 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2971 mode, contended_compaction);
2972 current->flags &= ~PF_MEMALLOC;
2974 switch (compact_result) {
2975 case COMPACT_DEFERRED:
2976 *deferred_compaction = true;
2978 case COMPACT_SKIPPED:
2985 * At least in one zone compaction wasn't deferred or skipped, so let's
2986 * count a compaction stall
2988 count_vm_event(COMPACTSTALL);
2990 page = get_page_from_freelist(gfp_mask, order,
2991 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2994 struct zone *zone = page_zone(page);
2996 zone->compact_blockskip_flush = false;
2997 compaction_defer_reset(zone, order, true);
2998 count_vm_event(COMPACTSUCCESS);
3003 * It's bad if compaction run occurs and fails. The most likely reason
3004 * is that pages exist, but not enough to satisfy watermarks.
3006 count_vm_event(COMPACTFAIL);
3013 static inline struct page *
3014 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3015 unsigned int alloc_flags, const struct alloc_context *ac,
3016 enum migrate_mode mode, int *contended_compaction,
3017 bool *deferred_compaction)
3021 #endif /* CONFIG_COMPACTION */
3023 /* Perform direct synchronous page reclaim */
3025 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3026 const struct alloc_context *ac)
3028 struct reclaim_state reclaim_state;
3033 /* We now go into synchronous reclaim */
3034 cpuset_memory_pressure_bump();
3035 current->flags |= PF_MEMALLOC;
3036 lockdep_set_current_reclaim_state(gfp_mask);
3037 reclaim_state.reclaimed_slab = 0;
3038 current->reclaim_state = &reclaim_state;
3040 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3043 current->reclaim_state = NULL;
3044 lockdep_clear_current_reclaim_state();
3045 current->flags &= ~PF_MEMALLOC;
3052 /* The really slow allocator path where we enter direct reclaim */
3053 static inline struct page *
3054 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3055 unsigned int alloc_flags, const struct alloc_context *ac,
3056 unsigned long *did_some_progress)
3058 struct page *page = NULL;
3059 bool drained = false;
3061 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3062 if (unlikely(!(*did_some_progress)))
3066 page = get_page_from_freelist(gfp_mask, order,
3067 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3070 * If an allocation failed after direct reclaim, it could be because
3071 * pages are pinned on the per-cpu lists or in high alloc reserves.
3072 * Shrink them them and try again
3074 if (!page && !drained) {
3075 unreserve_highatomic_pageblock(ac);
3076 drain_all_pages(NULL);
3084 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3089 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3090 ac->high_zoneidx, ac->nodemask)
3091 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
3094 static inline unsigned int
3095 gfp_to_alloc_flags(gfp_t gfp_mask)
3097 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3099 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3100 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3103 * The caller may dip into page reserves a bit more if the caller
3104 * cannot run direct reclaim, or if the caller has realtime scheduling
3105 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3106 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3108 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3110 if (gfp_mask & __GFP_ATOMIC) {
3112 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3113 * if it can't schedule.
3115 if (!(gfp_mask & __GFP_NOMEMALLOC))
3116 alloc_flags |= ALLOC_HARDER;
3118 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3119 * comment for __cpuset_node_allowed().
3121 alloc_flags &= ~ALLOC_CPUSET;
3122 } else if (unlikely(rt_task(current)) && !in_interrupt())
3123 alloc_flags |= ALLOC_HARDER;
3125 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3126 if (gfp_mask & __GFP_MEMALLOC)
3127 alloc_flags |= ALLOC_NO_WATERMARKS;
3128 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3129 alloc_flags |= ALLOC_NO_WATERMARKS;
3130 else if (!in_interrupt() &&
3131 ((current->flags & PF_MEMALLOC) ||
3132 unlikely(test_thread_flag(TIF_MEMDIE))))
3133 alloc_flags |= ALLOC_NO_WATERMARKS;
3136 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3137 alloc_flags |= ALLOC_CMA;
3142 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3144 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3147 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3149 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3152 static inline struct page *
3153 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3154 struct alloc_context *ac)
3156 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3157 struct page *page = NULL;
3158 unsigned int alloc_flags;
3159 unsigned long pages_reclaimed = 0;
3160 unsigned long did_some_progress;
3161 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3162 bool deferred_compaction = false;
3163 int contended_compaction = COMPACT_CONTENDED_NONE;
3166 * In the slowpath, we sanity check order to avoid ever trying to
3167 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3168 * be using allocators in order of preference for an area that is
3171 if (order >= MAX_ORDER) {
3172 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3177 * We also sanity check to catch abuse of atomic reserves being used by
3178 * callers that are not in atomic context.
3180 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3181 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3182 gfp_mask &= ~__GFP_ATOMIC;
3185 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3186 wake_all_kswapds(order, ac);
3189 * OK, we're below the kswapd watermark and have kicked background
3190 * reclaim. Now things get more complex, so set up alloc_flags according
3191 * to how we want to proceed.
3193 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3195 /* This is the last chance, in general, before the goto nopage. */
3196 page = get_page_from_freelist(gfp_mask, order,
3197 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3201 /* Allocate without watermarks if the context allows */
3202 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3204 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3205 * the allocation is high priority and these type of
3206 * allocations are system rather than user orientated
3208 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3209 page = get_page_from_freelist(gfp_mask, order,
3210 ALLOC_NO_WATERMARKS, ac);
3215 /* Caller is not willing to reclaim, we can't balance anything */
3216 if (!can_direct_reclaim) {
3218 * All existing users of the __GFP_NOFAIL are blockable, so warn
3219 * of any new users that actually allow this type of allocation
3222 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3226 /* Avoid recursion of direct reclaim */
3227 if (current->flags & PF_MEMALLOC) {
3229 * __GFP_NOFAIL request from this context is rather bizarre
3230 * because we cannot reclaim anything and only can loop waiting
3231 * for somebody to do a work for us.
3233 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3240 /* Avoid allocations with no watermarks from looping endlessly */
3241 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3245 * Try direct compaction. The first pass is asynchronous. Subsequent
3246 * attempts after direct reclaim are synchronous
3248 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3250 &contended_compaction,
3251 &deferred_compaction);
3255 /* Checks for THP-specific high-order allocations */
3256 if (is_thp_gfp_mask(gfp_mask)) {
3258 * If compaction is deferred for high-order allocations, it is
3259 * because sync compaction recently failed. If this is the case
3260 * and the caller requested a THP allocation, we do not want
3261 * to heavily disrupt the system, so we fail the allocation
3262 * instead of entering direct reclaim.
3264 if (deferred_compaction)
3268 * In all zones where compaction was attempted (and not
3269 * deferred or skipped), lock contention has been detected.
3270 * For THP allocation we do not want to disrupt the others
3271 * so we fallback to base pages instead.
3273 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3277 * If compaction was aborted due to need_resched(), we do not
3278 * want to further increase allocation latency, unless it is
3279 * khugepaged trying to collapse.
3281 if (contended_compaction == COMPACT_CONTENDED_SCHED
3282 && !(current->flags & PF_KTHREAD))
3287 * It can become very expensive to allocate transparent hugepages at
3288 * fault, so use asynchronous memory compaction for THP unless it is
3289 * khugepaged trying to collapse.
3291 if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
3292 migration_mode = MIGRATE_SYNC_LIGHT;
3294 /* Try direct reclaim and then allocating */
3295 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3296 &did_some_progress);
3300 /* Do not loop if specifically requested */
3301 if (gfp_mask & __GFP_NORETRY)
3304 /* Keep reclaiming pages as long as there is reasonable progress */
3305 pages_reclaimed += did_some_progress;
3306 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3307 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3308 /* Wait for some write requests to complete then retry */
3309 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
3313 /* Reclaim has failed us, start killing things */
3314 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3318 /* Retry as long as the OOM killer is making progress */
3319 if (did_some_progress)
3324 * High-order allocations do not necessarily loop after
3325 * direct reclaim and reclaim/compaction depends on compaction
3326 * being called after reclaim so call directly if necessary
3328 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3330 &contended_compaction,
3331 &deferred_compaction);
3335 warn_alloc_failed(gfp_mask, order, NULL);
3341 * This is the 'heart' of the zoned buddy allocator.
3344 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3345 struct zonelist *zonelist, nodemask_t *nodemask)
3347 struct zoneref *preferred_zoneref;
3349 unsigned int cpuset_mems_cookie;
3350 unsigned int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR;
3351 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3352 struct alloc_context ac = {
3353 .high_zoneidx = gfp_zone(gfp_mask),
3354 .zonelist = zonelist,
3355 .nodemask = nodemask,
3356 .migratetype = gfpflags_to_migratetype(gfp_mask),
3359 if (cpusets_enabled()) {
3360 alloc_mask |= __GFP_HARDWALL;
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) {
3400 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
3402 /* First allocation attempt */
3403 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3408 * Runtime PM, block IO and its error handling path can deadlock
3409 * because I/O on the device might not complete.
3411 alloc_mask = memalloc_noio_flags(gfp_mask);
3412 ac.spread_dirty_pages = false;
3414 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3418 * When updating a task's mems_allowed, it is possible to race with
3419 * parallel threads in such a way that an allocation can fail while
3420 * the mask is being updated. If a page allocation is about to fail,
3421 * check if the cpuset changed during allocation and if so, retry.
3423 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3424 alloc_mask = gfp_mask;
3429 if (kmemcheck_enabled && page)
3430 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3432 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3436 EXPORT_SYMBOL(__alloc_pages_nodemask);
3439 * Common helper functions.
3441 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3446 * __get_free_pages() returns a 32-bit address, which cannot represent
3449 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3451 page = alloc_pages(gfp_mask, order);
3454 return (unsigned long) page_address(page);
3456 EXPORT_SYMBOL(__get_free_pages);
3458 unsigned long get_zeroed_page(gfp_t gfp_mask)
3460 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3462 EXPORT_SYMBOL(get_zeroed_page);
3464 void __free_pages(struct page *page, unsigned int order)
3466 if (put_page_testzero(page)) {
3468 free_hot_cold_page(page, false);
3470 __free_pages_ok(page, order);
3474 EXPORT_SYMBOL(__free_pages);
3476 void free_pages(unsigned long addr, unsigned int order)
3479 VM_BUG_ON(!virt_addr_valid((void *)addr));
3480 __free_pages(virt_to_page((void *)addr), order);
3484 EXPORT_SYMBOL(free_pages);
3488 * An arbitrary-length arbitrary-offset area of memory which resides
3489 * within a 0 or higher order page. Multiple fragments within that page
3490 * are individually refcounted, in the page's reference counter.
3492 * The page_frag functions below provide a simple allocation framework for
3493 * page fragments. This is used by the network stack and network device
3494 * drivers to provide a backing region of memory for use as either an
3495 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3497 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3500 struct page *page = NULL;
3501 gfp_t gfp = gfp_mask;
3503 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3504 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3506 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3507 PAGE_FRAG_CACHE_MAX_ORDER);
3508 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3510 if (unlikely(!page))
3511 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3513 nc->va = page ? page_address(page) : NULL;
3518 void *__alloc_page_frag(struct page_frag_cache *nc,
3519 unsigned int fragsz, gfp_t gfp_mask)
3521 unsigned int size = PAGE_SIZE;
3525 if (unlikely(!nc->va)) {
3527 page = __page_frag_refill(nc, gfp_mask);
3531 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3532 /* if size can vary use size else just use PAGE_SIZE */
3535 /* Even if we own the page, we do not use atomic_set().
3536 * This would break get_page_unless_zero() users.
3538 page_ref_add(page, size - 1);
3540 /* reset page count bias and offset to start of new frag */
3541 nc->pfmemalloc = page_is_pfmemalloc(page);
3542 nc->pagecnt_bias = size;
3546 offset = nc->offset - fragsz;
3547 if (unlikely(offset < 0)) {
3548 page = virt_to_page(nc->va);
3550 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3553 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3554 /* if size can vary use size else just use PAGE_SIZE */
3557 /* OK, page count is 0, we can safely set it */
3558 set_page_count(page, size);
3560 /* reset page count bias and offset to start of new frag */
3561 nc->pagecnt_bias = size;
3562 offset = size - fragsz;
3566 nc->offset = offset;
3568 return nc->va + offset;
3570 EXPORT_SYMBOL(__alloc_page_frag);
3573 * Frees a page fragment allocated out of either a compound or order 0 page.
3575 void __free_page_frag(void *addr)
3577 struct page *page = virt_to_head_page(addr);
3579 if (unlikely(put_page_testzero(page)))
3580 __free_pages_ok(page, compound_order(page));
3582 EXPORT_SYMBOL(__free_page_frag);
3585 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3586 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3587 * equivalent to alloc_pages.
3589 * It should be used when the caller would like to use kmalloc, but since the
3590 * allocation is large, it has to fall back to the page allocator.
3592 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3596 page = alloc_pages(gfp_mask, order);
3597 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3598 __free_pages(page, order);
3604 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3608 page = alloc_pages_node(nid, gfp_mask, order);
3609 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3610 __free_pages(page, order);
3617 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3620 void __free_kmem_pages(struct page *page, unsigned int order)
3622 memcg_kmem_uncharge(page, order);
3623 __free_pages(page, order);
3626 void free_kmem_pages(unsigned long addr, unsigned int order)
3629 VM_BUG_ON(!virt_addr_valid((void *)addr));
3630 __free_kmem_pages(virt_to_page((void *)addr), order);
3634 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3638 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3639 unsigned long used = addr + PAGE_ALIGN(size);
3641 split_page(virt_to_page((void *)addr), order);
3642 while (used < alloc_end) {
3647 return (void *)addr;
3651 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3652 * @size: the number of bytes to allocate
3653 * @gfp_mask: GFP flags for the allocation
3655 * This function is similar to alloc_pages(), except that it allocates the
3656 * minimum number of pages to satisfy the request. alloc_pages() can only
3657 * allocate memory in power-of-two pages.
3659 * This function is also limited by MAX_ORDER.
3661 * Memory allocated by this function must be released by free_pages_exact().
3663 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3665 unsigned int order = get_order(size);
3668 addr = __get_free_pages(gfp_mask, order);
3669 return make_alloc_exact(addr, order, size);
3671 EXPORT_SYMBOL(alloc_pages_exact);
3674 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3676 * @nid: the preferred node ID where memory should be allocated
3677 * @size: the number of bytes to allocate
3678 * @gfp_mask: GFP flags for the allocation
3680 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3683 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3685 unsigned int order = get_order(size);
3686 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3689 return make_alloc_exact((unsigned long)page_address(p), order, size);
3693 * free_pages_exact - release memory allocated via alloc_pages_exact()
3694 * @virt: the value returned by alloc_pages_exact.
3695 * @size: size of allocation, same value as passed to alloc_pages_exact().
3697 * Release the memory allocated by a previous call to alloc_pages_exact.
3699 void free_pages_exact(void *virt, size_t size)
3701 unsigned long addr = (unsigned long)virt;
3702 unsigned long end = addr + PAGE_ALIGN(size);
3704 while (addr < end) {
3709 EXPORT_SYMBOL(free_pages_exact);
3712 * nr_free_zone_pages - count number of pages beyond high watermark
3713 * @offset: The zone index of the highest zone
3715 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3716 * high watermark within all zones at or below a given zone index. For each
3717 * zone, the number of pages is calculated as:
3718 * managed_pages - high_pages
3720 static unsigned long nr_free_zone_pages(int offset)
3725 /* Just pick one node, since fallback list is circular */
3726 unsigned long sum = 0;
3728 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3730 for_each_zone_zonelist(zone, z, zonelist, offset) {
3731 unsigned long size = zone->managed_pages;
3732 unsigned long high = high_wmark_pages(zone);
3741 * nr_free_buffer_pages - count number of pages beyond high watermark
3743 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3744 * watermark within ZONE_DMA and ZONE_NORMAL.
3746 unsigned long nr_free_buffer_pages(void)
3748 return nr_free_zone_pages(gfp_zone(GFP_USER));
3750 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3753 * nr_free_pagecache_pages - count number of pages beyond high watermark
3755 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3756 * high watermark within all zones.
3758 unsigned long nr_free_pagecache_pages(void)
3760 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3763 static inline void show_node(struct zone *zone)
3765 if (IS_ENABLED(CONFIG_NUMA))
3766 printk("Node %d ", zone_to_nid(zone));
3769 long si_mem_available(void)
3772 unsigned long pagecache;
3773 unsigned long wmark_low = 0;
3774 unsigned long pages[NR_LRU_LISTS];
3778 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
3779 pages[lru] = global_page_state(NR_LRU_BASE + lru);
3782 wmark_low += zone->watermark[WMARK_LOW];
3785 * Estimate the amount of memory available for userspace allocations,
3786 * without causing swapping.
3788 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
3791 * Not all the page cache can be freed, otherwise the system will
3792 * start swapping. Assume at least half of the page cache, or the
3793 * low watermark worth of cache, needs to stay.
3795 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
3796 pagecache -= min(pagecache / 2, wmark_low);
3797 available += pagecache;
3800 * Part of the reclaimable slab consists of items that are in use,
3801 * and cannot be freed. Cap this estimate at the low watermark.
3803 available += global_page_state(NR_SLAB_RECLAIMABLE) -
3804 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
3810 EXPORT_SYMBOL_GPL(si_mem_available);
3812 void si_meminfo(struct sysinfo *val)
3814 val->totalram = totalram_pages;
3815 val->sharedram = global_page_state(NR_SHMEM);
3816 val->freeram = global_page_state(NR_FREE_PAGES);
3817 val->bufferram = nr_blockdev_pages();
3818 val->totalhigh = totalhigh_pages;
3819 val->freehigh = nr_free_highpages();
3820 val->mem_unit = PAGE_SIZE;
3823 EXPORT_SYMBOL(si_meminfo);
3826 void si_meminfo_node(struct sysinfo *val, int nid)
3828 int zone_type; /* needs to be signed */
3829 unsigned long managed_pages = 0;
3830 unsigned long managed_highpages = 0;
3831 unsigned long free_highpages = 0;
3832 pg_data_t *pgdat = NODE_DATA(nid);
3834 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3835 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3836 val->totalram = managed_pages;
3837 val->sharedram = node_page_state(nid, NR_SHMEM);
3838 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3839 #ifdef CONFIG_HIGHMEM
3840 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3841 struct zone *zone = &pgdat->node_zones[zone_type];
3843 if (is_highmem(zone)) {
3844 managed_highpages += zone->managed_pages;
3845 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
3848 val->totalhigh = managed_highpages;
3849 val->freehigh = free_highpages;
3851 val->totalhigh = managed_highpages;
3852 val->freehigh = free_highpages;
3854 val->mem_unit = PAGE_SIZE;
3859 * Determine whether the node should be displayed or not, depending on whether
3860 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3862 bool skip_free_areas_node(unsigned int flags, int nid)
3865 unsigned int cpuset_mems_cookie;
3867 if (!(flags & SHOW_MEM_FILTER_NODES))
3871 cpuset_mems_cookie = read_mems_allowed_begin();
3872 ret = !node_isset(nid, cpuset_current_mems_allowed);
3873 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3878 #define K(x) ((x) << (PAGE_SHIFT-10))
3880 static void show_migration_types(unsigned char type)
3882 static const char types[MIGRATE_TYPES] = {
3883 [MIGRATE_UNMOVABLE] = 'U',
3884 [MIGRATE_MOVABLE] = 'M',
3885 [MIGRATE_RECLAIMABLE] = 'E',
3886 [MIGRATE_HIGHATOMIC] = 'H',
3888 [MIGRATE_CMA] = 'C',
3890 #ifdef CONFIG_MEMORY_ISOLATION
3891 [MIGRATE_ISOLATE] = 'I',
3894 char tmp[MIGRATE_TYPES + 1];
3898 for (i = 0; i < MIGRATE_TYPES; i++) {
3899 if (type & (1 << i))
3904 printk("(%s) ", tmp);
3908 * Show free area list (used inside shift_scroll-lock stuff)
3909 * We also calculate the percentage fragmentation. We do this by counting the
3910 * memory on each free list with the exception of the first item on the list.
3913 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3916 void show_free_areas(unsigned int filter)
3918 unsigned long free_pcp = 0;
3922 for_each_populated_zone(zone) {
3923 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3926 for_each_online_cpu(cpu)
3927 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3930 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3931 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3932 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3933 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3934 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3935 " free:%lu free_pcp:%lu free_cma:%lu\n",
3936 global_page_state(NR_ACTIVE_ANON),
3937 global_page_state(NR_INACTIVE_ANON),
3938 global_page_state(NR_ISOLATED_ANON),
3939 global_page_state(NR_ACTIVE_FILE),
3940 global_page_state(NR_INACTIVE_FILE),
3941 global_page_state(NR_ISOLATED_FILE),
3942 global_page_state(NR_UNEVICTABLE),
3943 global_page_state(NR_FILE_DIRTY),
3944 global_page_state(NR_WRITEBACK),
3945 global_page_state(NR_UNSTABLE_NFS),
3946 global_page_state(NR_SLAB_RECLAIMABLE),
3947 global_page_state(NR_SLAB_UNRECLAIMABLE),
3948 global_page_state(NR_FILE_MAPPED),
3949 global_page_state(NR_SHMEM),
3950 global_page_state(NR_PAGETABLE),
3951 global_page_state(NR_BOUNCE),
3952 global_page_state(NR_FREE_PAGES),
3954 global_page_state(NR_FREE_CMA_PAGES));
3956 for_each_populated_zone(zone) {
3959 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3963 for_each_online_cpu(cpu)
3964 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3972 " active_anon:%lukB"
3973 " inactive_anon:%lukB"
3974 " active_file:%lukB"
3975 " inactive_file:%lukB"
3976 " unevictable:%lukB"
3977 " isolated(anon):%lukB"
3978 " isolated(file):%lukB"
3986 " slab_reclaimable:%lukB"
3987 " slab_unreclaimable:%lukB"
3988 " kernel_stack:%lukB"
3995 " writeback_tmp:%lukB"
3996 " pages_scanned:%lu"
3997 " all_unreclaimable? %s"
4000 K(zone_page_state(zone, NR_FREE_PAGES)),
4001 K(min_wmark_pages(zone)),
4002 K(low_wmark_pages(zone)),
4003 K(high_wmark_pages(zone)),
4004 K(zone_page_state(zone, NR_ACTIVE_ANON)),
4005 K(zone_page_state(zone, NR_INACTIVE_ANON)),
4006 K(zone_page_state(zone, NR_ACTIVE_FILE)),
4007 K(zone_page_state(zone, NR_INACTIVE_FILE)),
4008 K(zone_page_state(zone, NR_UNEVICTABLE)),
4009 K(zone_page_state(zone, NR_ISOLATED_ANON)),
4010 K(zone_page_state(zone, NR_ISOLATED_FILE)),
4011 K(zone->present_pages),
4012 K(zone->managed_pages),
4013 K(zone_page_state(zone, NR_MLOCK)),
4014 K(zone_page_state(zone, NR_FILE_DIRTY)),
4015 K(zone_page_state(zone, NR_WRITEBACK)),
4016 K(zone_page_state(zone, NR_FILE_MAPPED)),
4017 K(zone_page_state(zone, NR_SHMEM)),
4018 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4019 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4020 zone_page_state(zone, NR_KERNEL_STACK) *
4022 K(zone_page_state(zone, NR_PAGETABLE)),
4023 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
4024 K(zone_page_state(zone, NR_BOUNCE)),
4026 K(this_cpu_read(zone->pageset->pcp.count)),
4027 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
4028 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
4029 K(zone_page_state(zone, NR_PAGES_SCANNED)),
4030 (!zone_reclaimable(zone) ? "yes" : "no")
4032 printk("lowmem_reserve[]:");
4033 for (i = 0; i < MAX_NR_ZONES; i++)
4034 printk(" %ld", zone->lowmem_reserve[i]);
4038 for_each_populated_zone(zone) {
4040 unsigned long nr[MAX_ORDER], flags, total = 0;
4041 unsigned char types[MAX_ORDER];
4043 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4046 printk("%s: ", zone->name);
4048 spin_lock_irqsave(&zone->lock, flags);
4049 for (order = 0; order < MAX_ORDER; order++) {
4050 struct free_area *area = &zone->free_area[order];
4053 nr[order] = area->nr_free;
4054 total += nr[order] << order;
4057 for (type = 0; type < MIGRATE_TYPES; type++) {
4058 if (!list_empty(&area->free_list[type]))
4059 types[order] |= 1 << type;
4062 spin_unlock_irqrestore(&zone->lock, flags);
4063 for (order = 0; order < MAX_ORDER; order++) {
4064 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4066 show_migration_types(types[order]);
4068 printk("= %lukB\n", K(total));
4071 hugetlb_show_meminfo();
4073 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4075 show_swap_cache_info();
4078 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4080 zoneref->zone = zone;
4081 zoneref->zone_idx = zone_idx(zone);
4085 * Builds allocation fallback zone lists.
4087 * Add all populated zones of a node to the zonelist.
4089 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4093 enum zone_type zone_type = MAX_NR_ZONES;
4097 zone = pgdat->node_zones + zone_type;
4098 if (populated_zone(zone)) {
4099 zoneref_set_zone(zone,
4100 &zonelist->_zonerefs[nr_zones++]);
4101 check_highest_zone(zone_type);
4103 } while (zone_type);
4111 * 0 = automatic detection of better ordering.
4112 * 1 = order by ([node] distance, -zonetype)
4113 * 2 = order by (-zonetype, [node] distance)
4115 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4116 * the same zonelist. So only NUMA can configure this param.
4118 #define ZONELIST_ORDER_DEFAULT 0
4119 #define ZONELIST_ORDER_NODE 1
4120 #define ZONELIST_ORDER_ZONE 2
4122 /* zonelist order in the kernel.
4123 * set_zonelist_order() will set this to NODE or ZONE.
4125 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4126 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4130 /* The value user specified ....changed by config */
4131 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4132 /* string for sysctl */
4133 #define NUMA_ZONELIST_ORDER_LEN 16
4134 char numa_zonelist_order[16] = "default";
4137 * interface for configure zonelist ordering.
4138 * command line option "numa_zonelist_order"
4139 * = "[dD]efault - default, automatic configuration.
4140 * = "[nN]ode - order by node locality, then by zone within node
4141 * = "[zZ]one - order by zone, then by locality within zone
4144 static int __parse_numa_zonelist_order(char *s)
4146 if (*s == 'd' || *s == 'D') {
4147 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4148 } else if (*s == 'n' || *s == 'N') {
4149 user_zonelist_order = ZONELIST_ORDER_NODE;
4150 } else if (*s == 'z' || *s == 'Z') {
4151 user_zonelist_order = ZONELIST_ORDER_ZONE;
4153 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4159 static __init int setup_numa_zonelist_order(char *s)
4166 ret = __parse_numa_zonelist_order(s);
4168 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4172 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4175 * sysctl handler for numa_zonelist_order
4177 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4178 void __user *buffer, size_t *length,
4181 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4183 static DEFINE_MUTEX(zl_order_mutex);
4185 mutex_lock(&zl_order_mutex);
4187 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4191 strcpy(saved_string, (char *)table->data);
4193 ret = proc_dostring(table, write, buffer, length, ppos);
4197 int oldval = user_zonelist_order;
4199 ret = __parse_numa_zonelist_order((char *)table->data);
4202 * bogus value. restore saved string
4204 strncpy((char *)table->data, saved_string,
4205 NUMA_ZONELIST_ORDER_LEN);
4206 user_zonelist_order = oldval;
4207 } else if (oldval != user_zonelist_order) {
4208 mutex_lock(&zonelists_mutex);
4209 build_all_zonelists(NULL, NULL);
4210 mutex_unlock(&zonelists_mutex);
4214 mutex_unlock(&zl_order_mutex);
4219 #define MAX_NODE_LOAD (nr_online_nodes)
4220 static int node_load[MAX_NUMNODES];
4223 * find_next_best_node - find the next node that should appear in a given node's fallback list
4224 * @node: node whose fallback list we're appending
4225 * @used_node_mask: nodemask_t of already used nodes
4227 * We use a number of factors to determine which is the next node that should
4228 * appear on a given node's fallback list. The node should not have appeared
4229 * already in @node's fallback list, and it should be the next closest node
4230 * according to the distance array (which contains arbitrary distance values
4231 * from each node to each node in the system), and should also prefer nodes
4232 * with no CPUs, since presumably they'll have very little allocation pressure
4233 * on them otherwise.
4234 * It returns -1 if no node is found.
4236 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4239 int min_val = INT_MAX;
4240 int best_node = NUMA_NO_NODE;
4241 const struct cpumask *tmp = cpumask_of_node(0);
4243 /* Use the local node if we haven't already */
4244 if (!node_isset(node, *used_node_mask)) {
4245 node_set(node, *used_node_mask);
4249 for_each_node_state(n, N_MEMORY) {
4251 /* Don't want a node to appear more than once */
4252 if (node_isset(n, *used_node_mask))
4255 /* Use the distance array to find the distance */
4256 val = node_distance(node, n);
4258 /* Penalize nodes under us ("prefer the next node") */
4261 /* Give preference to headless and unused nodes */
4262 tmp = cpumask_of_node(n);
4263 if (!cpumask_empty(tmp))
4264 val += PENALTY_FOR_NODE_WITH_CPUS;
4266 /* Slight preference for less loaded node */
4267 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4268 val += node_load[n];
4270 if (val < min_val) {
4277 node_set(best_node, *used_node_mask);
4284 * Build zonelists ordered by node and zones within node.
4285 * This results in maximum locality--normal zone overflows into local
4286 * DMA zone, if any--but risks exhausting DMA zone.
4288 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4291 struct zonelist *zonelist;
4293 zonelist = &pgdat->node_zonelists[0];
4294 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4296 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4297 zonelist->_zonerefs[j].zone = NULL;
4298 zonelist->_zonerefs[j].zone_idx = 0;
4302 * Build gfp_thisnode zonelists
4304 static void build_thisnode_zonelists(pg_data_t *pgdat)
4307 struct zonelist *zonelist;
4309 zonelist = &pgdat->node_zonelists[1];
4310 j = build_zonelists_node(pgdat, zonelist, 0);
4311 zonelist->_zonerefs[j].zone = NULL;
4312 zonelist->_zonerefs[j].zone_idx = 0;
4316 * Build zonelists ordered by zone and nodes within zones.
4317 * This results in conserving DMA zone[s] until all Normal memory is
4318 * exhausted, but results in overflowing to remote node while memory
4319 * may still exist in local DMA zone.
4321 static int node_order[MAX_NUMNODES];
4323 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4326 int zone_type; /* needs to be signed */
4328 struct zonelist *zonelist;
4330 zonelist = &pgdat->node_zonelists[0];
4332 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4333 for (j = 0; j < nr_nodes; j++) {
4334 node = node_order[j];
4335 z = &NODE_DATA(node)->node_zones[zone_type];
4336 if (populated_zone(z)) {
4338 &zonelist->_zonerefs[pos++]);
4339 check_highest_zone(zone_type);
4343 zonelist->_zonerefs[pos].zone = NULL;
4344 zonelist->_zonerefs[pos].zone_idx = 0;
4347 #if defined(CONFIG_64BIT)
4349 * Devices that require DMA32/DMA are relatively rare and do not justify a
4350 * penalty to every machine in case the specialised case applies. Default
4351 * to Node-ordering on 64-bit NUMA machines
4353 static int default_zonelist_order(void)
4355 return ZONELIST_ORDER_NODE;
4359 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4360 * by the kernel. If processes running on node 0 deplete the low memory zone
4361 * then reclaim will occur more frequency increasing stalls and potentially
4362 * be easier to OOM if a large percentage of the zone is under writeback or
4363 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4364 * Hence, default to zone ordering on 32-bit.
4366 static int default_zonelist_order(void)
4368 return ZONELIST_ORDER_ZONE;
4370 #endif /* CONFIG_64BIT */
4372 static void set_zonelist_order(void)
4374 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4375 current_zonelist_order = default_zonelist_order();
4377 current_zonelist_order = user_zonelist_order;
4380 static void build_zonelists(pg_data_t *pgdat)
4383 nodemask_t used_mask;
4384 int local_node, prev_node;
4385 struct zonelist *zonelist;
4386 unsigned int order = current_zonelist_order;
4388 /* initialize zonelists */
4389 for (i = 0; i < MAX_ZONELISTS; i++) {
4390 zonelist = pgdat->node_zonelists + i;
4391 zonelist->_zonerefs[0].zone = NULL;
4392 zonelist->_zonerefs[0].zone_idx = 0;
4395 /* NUMA-aware ordering of nodes */
4396 local_node = pgdat->node_id;
4397 load = nr_online_nodes;
4398 prev_node = local_node;
4399 nodes_clear(used_mask);
4401 memset(node_order, 0, sizeof(node_order));
4404 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4406 * We don't want to pressure a particular node.
4407 * So adding penalty to the first node in same
4408 * distance group to make it round-robin.
4410 if (node_distance(local_node, node) !=
4411 node_distance(local_node, prev_node))
4412 node_load[node] = load;
4416 if (order == ZONELIST_ORDER_NODE)
4417 build_zonelists_in_node_order(pgdat, node);
4419 node_order[i++] = node; /* remember order */
4422 if (order == ZONELIST_ORDER_ZONE) {
4423 /* calculate node order -- i.e., DMA last! */
4424 build_zonelists_in_zone_order(pgdat, i);
4427 build_thisnode_zonelists(pgdat);
4430 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4432 * Return node id of node used for "local" allocations.
4433 * I.e., first node id of first zone in arg node's generic zonelist.
4434 * Used for initializing percpu 'numa_mem', which is used primarily
4435 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4437 int local_memory_node(int node)
4441 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4442 gfp_zone(GFP_KERNEL),
4449 #else /* CONFIG_NUMA */
4451 static void set_zonelist_order(void)
4453 current_zonelist_order = ZONELIST_ORDER_ZONE;
4456 static void build_zonelists(pg_data_t *pgdat)
4458 int node, local_node;
4460 struct zonelist *zonelist;
4462 local_node = pgdat->node_id;
4464 zonelist = &pgdat->node_zonelists[0];
4465 j = build_zonelists_node(pgdat, zonelist, 0);
4468 * Now we build the zonelist so that it contains the zones
4469 * of all the other nodes.
4470 * We don't want to pressure a particular node, so when
4471 * building the zones for node N, we make sure that the
4472 * zones coming right after the local ones are those from
4473 * node N+1 (modulo N)
4475 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4476 if (!node_online(node))
4478 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4480 for (node = 0; node < local_node; node++) {
4481 if (!node_online(node))
4483 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4486 zonelist->_zonerefs[j].zone = NULL;
4487 zonelist->_zonerefs[j].zone_idx = 0;
4490 #endif /* CONFIG_NUMA */
4493 * Boot pageset table. One per cpu which is going to be used for all
4494 * zones and all nodes. The parameters will be set in such a way
4495 * that an item put on a list will immediately be handed over to
4496 * the buddy list. This is safe since pageset manipulation is done
4497 * with interrupts disabled.
4499 * The boot_pagesets must be kept even after bootup is complete for
4500 * unused processors and/or zones. They do play a role for bootstrapping
4501 * hotplugged processors.
4503 * zoneinfo_show() and maybe other functions do
4504 * not check if the processor is online before following the pageset pointer.
4505 * Other parts of the kernel may not check if the zone is available.
4507 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4508 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4509 static void setup_zone_pageset(struct zone *zone);
4512 * Global mutex to protect against size modification of zonelists
4513 * as well as to serialize pageset setup for the new populated zone.
4515 DEFINE_MUTEX(zonelists_mutex);
4517 /* return values int ....just for stop_machine() */
4518 static int __build_all_zonelists(void *data)
4522 pg_data_t *self = data;
4525 memset(node_load, 0, sizeof(node_load));
4528 if (self && !node_online(self->node_id)) {
4529 build_zonelists(self);
4532 for_each_online_node(nid) {
4533 pg_data_t *pgdat = NODE_DATA(nid);
4535 build_zonelists(pgdat);
4539 * Initialize the boot_pagesets that are going to be used
4540 * for bootstrapping processors. The real pagesets for
4541 * each zone will be allocated later when the per cpu
4542 * allocator is available.
4544 * boot_pagesets are used also for bootstrapping offline
4545 * cpus if the system is already booted because the pagesets
4546 * are needed to initialize allocators on a specific cpu too.
4547 * F.e. the percpu allocator needs the page allocator which
4548 * needs the percpu allocator in order to allocate its pagesets
4549 * (a chicken-egg dilemma).
4551 for_each_possible_cpu(cpu) {
4552 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4554 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4556 * We now know the "local memory node" for each node--
4557 * i.e., the node of the first zone in the generic zonelist.
4558 * Set up numa_mem percpu variable for on-line cpus. During
4559 * boot, only the boot cpu should be on-line; we'll init the
4560 * secondary cpus' numa_mem as they come on-line. During
4561 * node/memory hotplug, we'll fixup all on-line cpus.
4563 if (cpu_online(cpu))
4564 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4571 static noinline void __init
4572 build_all_zonelists_init(void)
4574 __build_all_zonelists(NULL);
4575 mminit_verify_zonelist();
4576 cpuset_init_current_mems_allowed();
4580 * Called with zonelists_mutex held always
4581 * unless system_state == SYSTEM_BOOTING.
4583 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4584 * [we're only called with non-NULL zone through __meminit paths] and
4585 * (2) call of __init annotated helper build_all_zonelists_init
4586 * [protected by SYSTEM_BOOTING].
4588 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4590 set_zonelist_order();
4592 if (system_state == SYSTEM_BOOTING) {
4593 build_all_zonelists_init();
4595 #ifdef CONFIG_MEMORY_HOTPLUG
4597 setup_zone_pageset(zone);
4599 /* we have to stop all cpus to guarantee there is no user
4601 stop_machine(__build_all_zonelists, pgdat, NULL);
4602 /* cpuset refresh routine should be here */
4604 vm_total_pages = nr_free_pagecache_pages();
4606 * Disable grouping by mobility if the number of pages in the
4607 * system is too low to allow the mechanism to work. It would be
4608 * more accurate, but expensive to check per-zone. This check is
4609 * made on memory-hotadd so a system can start with mobility
4610 * disabled and enable it later
4612 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4613 page_group_by_mobility_disabled = 1;
4615 page_group_by_mobility_disabled = 0;
4617 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4619 zonelist_order_name[current_zonelist_order],
4620 page_group_by_mobility_disabled ? "off" : "on",
4623 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4628 * Helper functions to size the waitqueue hash table.
4629 * Essentially these want to choose hash table sizes sufficiently
4630 * large so that collisions trying to wait on pages are rare.
4631 * But in fact, the number of active page waitqueues on typical
4632 * systems is ridiculously low, less than 200. So this is even
4633 * conservative, even though it seems large.
4635 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4636 * waitqueues, i.e. the size of the waitq table given the number of pages.
4638 #define PAGES_PER_WAITQUEUE 256
4640 #ifndef CONFIG_MEMORY_HOTPLUG
4641 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4643 unsigned long size = 1;
4645 pages /= PAGES_PER_WAITQUEUE;
4647 while (size < pages)
4651 * Once we have dozens or even hundreds of threads sleeping
4652 * on IO we've got bigger problems than wait queue collision.
4653 * Limit the size of the wait table to a reasonable size.
4655 size = min(size, 4096UL);
4657 return max(size, 4UL);
4661 * A zone's size might be changed by hot-add, so it is not possible to determine
4662 * a suitable size for its wait_table. So we use the maximum size now.
4664 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4666 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4667 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4668 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4670 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4671 * or more by the traditional way. (See above). It equals:
4673 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4674 * ia64(16K page size) : = ( 8G + 4M)byte.
4675 * powerpc (64K page size) : = (32G +16M)byte.
4677 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4684 * This is an integer logarithm so that shifts can be used later
4685 * to extract the more random high bits from the multiplicative
4686 * hash function before the remainder is taken.
4688 static inline unsigned long wait_table_bits(unsigned long size)
4694 * Initially all pages are reserved - free ones are freed
4695 * up by free_all_bootmem() once the early boot process is
4696 * done. Non-atomic initialization, single-pass.
4698 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4699 unsigned long start_pfn, enum memmap_context context)
4701 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
4702 unsigned long end_pfn = start_pfn + size;
4703 pg_data_t *pgdat = NODE_DATA(nid);
4705 unsigned long nr_initialised = 0;
4706 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4707 struct memblock_region *r = NULL, *tmp;
4710 if (highest_memmap_pfn < end_pfn - 1)
4711 highest_memmap_pfn = end_pfn - 1;
4714 * Honor reservation requested by the driver for this ZONE_DEVICE
4717 if (altmap && start_pfn == altmap->base_pfn)
4718 start_pfn += altmap->reserve;
4720 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4722 * There can be holes in boot-time mem_map[]s handed to this
4723 * function. They do not exist on hotplugged memory.
4725 if (context != MEMMAP_EARLY)
4728 if (!early_pfn_valid(pfn))
4730 if (!early_pfn_in_nid(pfn, nid))
4732 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
4735 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4737 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4738 * from zone_movable_pfn[nid] to end of each node should be
4739 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4741 if (!mirrored_kernelcore && zone_movable_pfn[nid])
4742 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
4746 * Check given memblock attribute by firmware which can affect
4747 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4748 * mirrored, it's an overlapped memmap init. skip it.
4750 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
4751 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
4752 for_each_memblock(memory, tmp)
4753 if (pfn < memblock_region_memory_end_pfn(tmp))
4757 if (pfn >= memblock_region_memory_base_pfn(r) &&
4758 memblock_is_mirror(r)) {
4759 /* already initialized as NORMAL */
4760 pfn = memblock_region_memory_end_pfn(r);
4768 * Mark the block movable so that blocks are reserved for
4769 * movable at startup. This will force kernel allocations
4770 * to reserve their blocks rather than leaking throughout
4771 * the address space during boot when many long-lived
4772 * kernel allocations are made.
4774 * bitmap is created for zone's valid pfn range. but memmap
4775 * can be created for invalid pages (for alignment)
4776 * check here not to call set_pageblock_migratetype() against
4779 if (!(pfn & (pageblock_nr_pages - 1))) {
4780 struct page *page = pfn_to_page(pfn);
4782 __init_single_page(page, pfn, zone, nid);
4783 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4785 __init_single_pfn(pfn, zone, nid);
4790 static void __meminit zone_init_free_lists(struct zone *zone)
4792 unsigned int order, t;
4793 for_each_migratetype_order(order, t) {
4794 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4795 zone->free_area[order].nr_free = 0;
4799 #ifndef __HAVE_ARCH_MEMMAP_INIT
4800 #define memmap_init(size, nid, zone, start_pfn) \
4801 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4804 static int zone_batchsize(struct zone *zone)
4810 * The per-cpu-pages pools are set to around 1000th of the
4811 * size of the zone. But no more than 1/2 of a meg.
4813 * OK, so we don't know how big the cache is. So guess.
4815 batch = zone->managed_pages / 1024;
4816 if (batch * PAGE_SIZE > 512 * 1024)
4817 batch = (512 * 1024) / PAGE_SIZE;
4818 batch /= 4; /* We effectively *= 4 below */
4823 * Clamp the batch to a 2^n - 1 value. Having a power
4824 * of 2 value was found to be more likely to have
4825 * suboptimal cache aliasing properties in some cases.
4827 * For example if 2 tasks are alternately allocating
4828 * batches of pages, one task can end up with a lot
4829 * of pages of one half of the possible page colors
4830 * and the other with pages of the other colors.
4832 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4837 /* The deferral and batching of frees should be suppressed under NOMMU
4840 * The problem is that NOMMU needs to be able to allocate large chunks
4841 * of contiguous memory as there's no hardware page translation to
4842 * assemble apparent contiguous memory from discontiguous pages.
4844 * Queueing large contiguous runs of pages for batching, however,
4845 * causes the pages to actually be freed in smaller chunks. As there
4846 * can be a significant delay between the individual batches being
4847 * recycled, this leads to the once large chunks of space being
4848 * fragmented and becoming unavailable for high-order allocations.
4855 * pcp->high and pcp->batch values are related and dependent on one another:
4856 * ->batch must never be higher then ->high.
4857 * The following function updates them in a safe manner without read side
4860 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4861 * those fields changing asynchronously (acording the the above rule).
4863 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4864 * outside of boot time (or some other assurance that no concurrent updaters
4867 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4868 unsigned long batch)
4870 /* start with a fail safe value for batch */
4874 /* Update high, then batch, in order */
4881 /* a companion to pageset_set_high() */
4882 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4884 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4887 static void pageset_init(struct per_cpu_pageset *p)
4889 struct per_cpu_pages *pcp;
4892 memset(p, 0, sizeof(*p));
4896 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4897 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4900 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4903 pageset_set_batch(p, batch);
4907 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4908 * to the value high for the pageset p.
4910 static void pageset_set_high(struct per_cpu_pageset *p,
4913 unsigned long batch = max(1UL, high / 4);
4914 if ((high / 4) > (PAGE_SHIFT * 8))
4915 batch = PAGE_SHIFT * 8;
4917 pageset_update(&p->pcp, high, batch);
4920 static void pageset_set_high_and_batch(struct zone *zone,
4921 struct per_cpu_pageset *pcp)
4923 if (percpu_pagelist_fraction)
4924 pageset_set_high(pcp,
4925 (zone->managed_pages /
4926 percpu_pagelist_fraction));
4928 pageset_set_batch(pcp, zone_batchsize(zone));
4931 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4933 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4936 pageset_set_high_and_batch(zone, pcp);
4939 static void __meminit setup_zone_pageset(struct zone *zone)
4942 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4943 for_each_possible_cpu(cpu)
4944 zone_pageset_init(zone, cpu);
4948 * Allocate per cpu pagesets and initialize them.
4949 * Before this call only boot pagesets were available.
4951 void __init setup_per_cpu_pageset(void)
4955 for_each_populated_zone(zone)
4956 setup_zone_pageset(zone);
4959 static noinline __init_refok
4960 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4966 * The per-page waitqueue mechanism uses hashed waitqueues
4969 zone->wait_table_hash_nr_entries =
4970 wait_table_hash_nr_entries(zone_size_pages);
4971 zone->wait_table_bits =
4972 wait_table_bits(zone->wait_table_hash_nr_entries);
4973 alloc_size = zone->wait_table_hash_nr_entries
4974 * sizeof(wait_queue_head_t);
4976 if (!slab_is_available()) {
4977 zone->wait_table = (wait_queue_head_t *)
4978 memblock_virt_alloc_node_nopanic(
4979 alloc_size, zone->zone_pgdat->node_id);
4982 * This case means that a zone whose size was 0 gets new memory
4983 * via memory hot-add.
4984 * But it may be the case that a new node was hot-added. In
4985 * this case vmalloc() will not be able to use this new node's
4986 * memory - this wait_table must be initialized to use this new
4987 * node itself as well.
4988 * To use this new node's memory, further consideration will be
4991 zone->wait_table = vmalloc(alloc_size);
4993 if (!zone->wait_table)
4996 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4997 init_waitqueue_head(zone->wait_table + i);
5002 static __meminit void zone_pcp_init(struct zone *zone)
5005 * per cpu subsystem is not up at this point. The following code
5006 * relies on the ability of the linker to provide the
5007 * offset of a (static) per cpu variable into the per cpu area.
5009 zone->pageset = &boot_pageset;
5011 if (populated_zone(zone))
5012 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5013 zone->name, zone->present_pages,
5014 zone_batchsize(zone));
5017 int __meminit init_currently_empty_zone(struct zone *zone,
5018 unsigned long zone_start_pfn,
5021 struct pglist_data *pgdat = zone->zone_pgdat;
5023 ret = zone_wait_table_init(zone, size);
5026 pgdat->nr_zones = zone_idx(zone) + 1;
5028 zone->zone_start_pfn = zone_start_pfn;
5030 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5031 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5033 (unsigned long)zone_idx(zone),
5034 zone_start_pfn, (zone_start_pfn + size));
5036 zone_init_free_lists(zone);
5041 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5042 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5045 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5047 int __meminit __early_pfn_to_nid(unsigned long pfn,
5048 struct mminit_pfnnid_cache *state)
5050 unsigned long start_pfn, end_pfn;
5053 if (state->last_start <= pfn && pfn < state->last_end)
5054 return state->last_nid;
5056 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5058 state->last_start = start_pfn;
5059 state->last_end = end_pfn;
5060 state->last_nid = nid;
5065 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5068 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5069 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5070 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5072 * If an architecture guarantees that all ranges registered contain no holes
5073 * and may be freed, this this function may be used instead of calling
5074 * memblock_free_early_nid() manually.
5076 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5078 unsigned long start_pfn, end_pfn;
5081 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5082 start_pfn = min(start_pfn, max_low_pfn);
5083 end_pfn = min(end_pfn, max_low_pfn);
5085 if (start_pfn < end_pfn)
5086 memblock_free_early_nid(PFN_PHYS(start_pfn),
5087 (end_pfn - start_pfn) << PAGE_SHIFT,
5093 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5094 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5096 * If an architecture guarantees that all ranges registered contain no holes and may
5097 * be freed, this function may be used instead of calling memory_present() manually.
5099 void __init sparse_memory_present_with_active_regions(int nid)
5101 unsigned long start_pfn, end_pfn;
5104 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5105 memory_present(this_nid, start_pfn, end_pfn);
5109 * get_pfn_range_for_nid - Return the start and end page frames for a node
5110 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5111 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5112 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5114 * It returns the start and end page frame of a node based on information
5115 * provided by memblock_set_node(). If called for a node
5116 * with no available memory, a warning is printed and the start and end
5119 void __meminit get_pfn_range_for_nid(unsigned int nid,
5120 unsigned long *start_pfn, unsigned long *end_pfn)
5122 unsigned long this_start_pfn, this_end_pfn;
5128 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5129 *start_pfn = min(*start_pfn, this_start_pfn);
5130 *end_pfn = max(*end_pfn, this_end_pfn);
5133 if (*start_pfn == -1UL)
5138 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5139 * assumption is made that zones within a node are ordered in monotonic
5140 * increasing memory addresses so that the "highest" populated zone is used
5142 static void __init find_usable_zone_for_movable(void)
5145 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5146 if (zone_index == ZONE_MOVABLE)
5149 if (arch_zone_highest_possible_pfn[zone_index] >
5150 arch_zone_lowest_possible_pfn[zone_index])
5154 VM_BUG_ON(zone_index == -1);
5155 movable_zone = zone_index;
5159 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5160 * because it is sized independent of architecture. Unlike the other zones,
5161 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5162 * in each node depending on the size of each node and how evenly kernelcore
5163 * is distributed. This helper function adjusts the zone ranges
5164 * provided by the architecture for a given node by using the end of the
5165 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5166 * zones within a node are in order of monotonic increases memory addresses
5168 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5169 unsigned long zone_type,
5170 unsigned long node_start_pfn,
5171 unsigned long node_end_pfn,
5172 unsigned long *zone_start_pfn,
5173 unsigned long *zone_end_pfn)
5175 /* Only adjust if ZONE_MOVABLE is on this node */
5176 if (zone_movable_pfn[nid]) {
5177 /* Size ZONE_MOVABLE */
5178 if (zone_type == ZONE_MOVABLE) {
5179 *zone_start_pfn = zone_movable_pfn[nid];
5180 *zone_end_pfn = min(node_end_pfn,
5181 arch_zone_highest_possible_pfn[movable_zone]);
5183 /* Check if this whole range is within ZONE_MOVABLE */
5184 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5185 *zone_start_pfn = *zone_end_pfn;
5190 * Return the number of pages a zone spans in a node, including holes
5191 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5193 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5194 unsigned long zone_type,
5195 unsigned long node_start_pfn,
5196 unsigned long node_end_pfn,
5197 unsigned long *zone_start_pfn,
5198 unsigned long *zone_end_pfn,
5199 unsigned long *ignored)
5201 /* When hotadd a new node from cpu_up(), the node should be empty */
5202 if (!node_start_pfn && !node_end_pfn)
5205 /* Get the start and end of the zone */
5206 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5207 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5208 adjust_zone_range_for_zone_movable(nid, zone_type,
5209 node_start_pfn, node_end_pfn,
5210 zone_start_pfn, zone_end_pfn);
5212 /* Check that this node has pages within the zone's required range */
5213 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5216 /* Move the zone boundaries inside the node if necessary */
5217 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5218 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5220 /* Return the spanned pages */
5221 return *zone_end_pfn - *zone_start_pfn;
5225 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5226 * then all holes in the requested range will be accounted for.
5228 unsigned long __meminit __absent_pages_in_range(int nid,
5229 unsigned long range_start_pfn,
5230 unsigned long range_end_pfn)
5232 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5233 unsigned long start_pfn, end_pfn;
5236 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5237 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5238 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5239 nr_absent -= end_pfn - start_pfn;
5245 * absent_pages_in_range - Return number of page frames in holes within a range
5246 * @start_pfn: The start PFN to start searching for holes
5247 * @end_pfn: The end PFN to stop searching for holes
5249 * It returns the number of pages frames in memory holes within a range.
5251 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5252 unsigned long end_pfn)
5254 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5257 /* Return the number of page frames in holes in a zone on a node */
5258 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5259 unsigned long zone_type,
5260 unsigned long node_start_pfn,
5261 unsigned long node_end_pfn,
5262 unsigned long *ignored)
5264 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5265 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5266 unsigned long zone_start_pfn, zone_end_pfn;
5267 unsigned long nr_absent;
5269 /* When hotadd a new node from cpu_up(), the node should be empty */
5270 if (!node_start_pfn && !node_end_pfn)
5273 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5274 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5276 adjust_zone_range_for_zone_movable(nid, zone_type,
5277 node_start_pfn, node_end_pfn,
5278 &zone_start_pfn, &zone_end_pfn);
5279 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5282 * ZONE_MOVABLE handling.
5283 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5286 if (zone_movable_pfn[nid]) {
5287 if (mirrored_kernelcore) {
5288 unsigned long start_pfn, end_pfn;
5289 struct memblock_region *r;
5291 for_each_memblock(memory, r) {
5292 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5293 zone_start_pfn, zone_end_pfn);
5294 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5295 zone_start_pfn, zone_end_pfn);
5297 if (zone_type == ZONE_MOVABLE &&
5298 memblock_is_mirror(r))
5299 nr_absent += end_pfn - start_pfn;
5301 if (zone_type == ZONE_NORMAL &&
5302 !memblock_is_mirror(r))
5303 nr_absent += end_pfn - start_pfn;
5306 if (zone_type == ZONE_NORMAL)
5307 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5314 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5315 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5316 unsigned long zone_type,
5317 unsigned long node_start_pfn,
5318 unsigned long node_end_pfn,
5319 unsigned long *zone_start_pfn,
5320 unsigned long *zone_end_pfn,
5321 unsigned long *zones_size)
5325 *zone_start_pfn = node_start_pfn;
5326 for (zone = 0; zone < zone_type; zone++)
5327 *zone_start_pfn += zones_size[zone];
5329 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5331 return zones_size[zone_type];
5334 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5335 unsigned long zone_type,
5336 unsigned long node_start_pfn,
5337 unsigned long node_end_pfn,
5338 unsigned long *zholes_size)
5343 return zholes_size[zone_type];
5346 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5348 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5349 unsigned long node_start_pfn,
5350 unsigned long node_end_pfn,
5351 unsigned long *zones_size,
5352 unsigned long *zholes_size)
5354 unsigned long realtotalpages = 0, totalpages = 0;
5357 for (i = 0; i < MAX_NR_ZONES; i++) {
5358 struct zone *zone = pgdat->node_zones + i;
5359 unsigned long zone_start_pfn, zone_end_pfn;
5360 unsigned long size, real_size;
5362 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5368 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5369 node_start_pfn, node_end_pfn,
5372 zone->zone_start_pfn = zone_start_pfn;
5374 zone->zone_start_pfn = 0;
5375 zone->spanned_pages = size;
5376 zone->present_pages = real_size;
5379 realtotalpages += real_size;
5382 pgdat->node_spanned_pages = totalpages;
5383 pgdat->node_present_pages = realtotalpages;
5384 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5388 #ifndef CONFIG_SPARSEMEM
5390 * Calculate the size of the zone->blockflags rounded to an unsigned long
5391 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5392 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5393 * round what is now in bits to nearest long in bits, then return it in
5396 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5398 unsigned long usemapsize;
5400 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5401 usemapsize = roundup(zonesize, pageblock_nr_pages);
5402 usemapsize = usemapsize >> pageblock_order;
5403 usemapsize *= NR_PAGEBLOCK_BITS;
5404 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5406 return usemapsize / 8;
5409 static void __init setup_usemap(struct pglist_data *pgdat,
5411 unsigned long zone_start_pfn,
5412 unsigned long zonesize)
5414 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5415 zone->pageblock_flags = NULL;
5417 zone->pageblock_flags =
5418 memblock_virt_alloc_node_nopanic(usemapsize,
5422 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5423 unsigned long zone_start_pfn, unsigned long zonesize) {}
5424 #endif /* CONFIG_SPARSEMEM */
5426 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5428 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5429 void __paginginit set_pageblock_order(void)
5433 /* Check that pageblock_nr_pages has not already been setup */
5434 if (pageblock_order)
5437 if (HPAGE_SHIFT > PAGE_SHIFT)
5438 order = HUGETLB_PAGE_ORDER;
5440 order = MAX_ORDER - 1;
5443 * Assume the largest contiguous order of interest is a huge page.
5444 * This value may be variable depending on boot parameters on IA64 and
5447 pageblock_order = order;
5449 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5452 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5453 * is unused as pageblock_order is set at compile-time. See
5454 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5457 void __paginginit set_pageblock_order(void)
5461 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5463 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5464 unsigned long present_pages)
5466 unsigned long pages = spanned_pages;
5469 * Provide a more accurate estimation if there are holes within
5470 * the zone and SPARSEMEM is in use. If there are holes within the
5471 * zone, each populated memory region may cost us one or two extra
5472 * memmap pages due to alignment because memmap pages for each
5473 * populated regions may not naturally algined on page boundary.
5474 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5476 if (spanned_pages > present_pages + (present_pages >> 4) &&
5477 IS_ENABLED(CONFIG_SPARSEMEM))
5478 pages = present_pages;
5480 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5484 * Set up the zone data structures:
5485 * - mark all pages reserved
5486 * - mark all memory queues empty
5487 * - clear the memory bitmaps
5489 * NOTE: pgdat should get zeroed by caller.
5491 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5494 int nid = pgdat->node_id;
5497 pgdat_resize_init(pgdat);
5498 #ifdef CONFIG_NUMA_BALANCING
5499 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5500 pgdat->numabalancing_migrate_nr_pages = 0;
5501 pgdat->numabalancing_migrate_next_window = jiffies;
5503 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5504 spin_lock_init(&pgdat->split_queue_lock);
5505 INIT_LIST_HEAD(&pgdat->split_queue);
5506 pgdat->split_queue_len = 0;
5508 init_waitqueue_head(&pgdat->kswapd_wait);
5509 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5510 #ifdef CONFIG_COMPACTION
5511 init_waitqueue_head(&pgdat->kcompactd_wait);
5513 pgdat_page_ext_init(pgdat);
5515 for (j = 0; j < MAX_NR_ZONES; j++) {
5516 struct zone *zone = pgdat->node_zones + j;
5517 unsigned long size, realsize, freesize, memmap_pages;
5518 unsigned long zone_start_pfn = zone->zone_start_pfn;
5520 size = zone->spanned_pages;
5521 realsize = freesize = zone->present_pages;
5524 * Adjust freesize so that it accounts for how much memory
5525 * is used by this zone for memmap. This affects the watermark
5526 * and per-cpu initialisations
5528 memmap_pages = calc_memmap_size(size, realsize);
5529 if (!is_highmem_idx(j)) {
5530 if (freesize >= memmap_pages) {
5531 freesize -= memmap_pages;
5534 " %s zone: %lu pages used for memmap\n",
5535 zone_names[j], memmap_pages);
5537 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5538 zone_names[j], memmap_pages, freesize);
5541 /* Account for reserved pages */
5542 if (j == 0 && freesize > dma_reserve) {
5543 freesize -= dma_reserve;
5544 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5545 zone_names[0], dma_reserve);
5548 if (!is_highmem_idx(j))
5549 nr_kernel_pages += freesize;
5550 /* Charge for highmem memmap if there are enough kernel pages */
5551 else if (nr_kernel_pages > memmap_pages * 2)
5552 nr_kernel_pages -= memmap_pages;
5553 nr_all_pages += freesize;
5556 * Set an approximate value for lowmem here, it will be adjusted
5557 * when the bootmem allocator frees pages into the buddy system.
5558 * And all highmem pages will be managed by the buddy system.
5560 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5563 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5565 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5567 zone->name = zone_names[j];
5568 spin_lock_init(&zone->lock);
5569 spin_lock_init(&zone->lru_lock);
5570 zone_seqlock_init(zone);
5571 zone->zone_pgdat = pgdat;
5572 zone_pcp_init(zone);
5574 /* For bootup, initialized properly in watermark setup */
5575 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5577 lruvec_init(&zone->lruvec);
5581 set_pageblock_order();
5582 setup_usemap(pgdat, zone, zone_start_pfn, size);
5583 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5585 memmap_init(size, nid, j, zone_start_pfn);
5589 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5591 unsigned long __maybe_unused start = 0;
5592 unsigned long __maybe_unused offset = 0;
5594 /* Skip empty nodes */
5595 if (!pgdat->node_spanned_pages)
5598 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5599 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5600 offset = pgdat->node_start_pfn - start;
5601 /* ia64 gets its own node_mem_map, before this, without bootmem */
5602 if (!pgdat->node_mem_map) {
5603 unsigned long size, end;
5607 * The zone's endpoints aren't required to be MAX_ORDER
5608 * aligned but the node_mem_map endpoints must be in order
5609 * for the buddy allocator to function correctly.
5611 end = pgdat_end_pfn(pgdat);
5612 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5613 size = (end - start) * sizeof(struct page);
5614 map = alloc_remap(pgdat->node_id, size);
5616 map = memblock_virt_alloc_node_nopanic(size,
5618 pgdat->node_mem_map = map + offset;
5620 #ifndef CONFIG_NEED_MULTIPLE_NODES
5622 * With no DISCONTIG, the global mem_map is just set as node 0's
5624 if (pgdat == NODE_DATA(0)) {
5625 mem_map = NODE_DATA(0)->node_mem_map;
5626 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5627 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5629 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5632 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5635 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5636 unsigned long node_start_pfn, unsigned long *zholes_size)
5638 pg_data_t *pgdat = NODE_DATA(nid);
5639 unsigned long start_pfn = 0;
5640 unsigned long end_pfn = 0;
5642 /* pg_data_t should be reset to zero when it's allocated */
5643 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5645 reset_deferred_meminit(pgdat);
5646 pgdat->node_id = nid;
5647 pgdat->node_start_pfn = node_start_pfn;
5648 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5649 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5650 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5651 (u64)start_pfn << PAGE_SHIFT,
5652 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5654 start_pfn = node_start_pfn;
5656 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5657 zones_size, zholes_size);
5659 alloc_node_mem_map(pgdat);
5660 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5661 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5662 nid, (unsigned long)pgdat,
5663 (unsigned long)pgdat->node_mem_map);
5666 free_area_init_core(pgdat);
5669 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5671 #if MAX_NUMNODES > 1
5673 * Figure out the number of possible node ids.
5675 void __init setup_nr_node_ids(void)
5677 unsigned int highest;
5679 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5680 nr_node_ids = highest + 1;
5685 * node_map_pfn_alignment - determine the maximum internode alignment
5687 * This function should be called after node map is populated and sorted.
5688 * It calculates the maximum power of two alignment which can distinguish
5691 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5692 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5693 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5694 * shifted, 1GiB is enough and this function will indicate so.
5696 * This is used to test whether pfn -> nid mapping of the chosen memory
5697 * model has fine enough granularity to avoid incorrect mapping for the
5698 * populated node map.
5700 * Returns the determined alignment in pfn's. 0 if there is no alignment
5701 * requirement (single node).
5703 unsigned long __init node_map_pfn_alignment(void)
5705 unsigned long accl_mask = 0, last_end = 0;
5706 unsigned long start, end, mask;
5710 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5711 if (!start || last_nid < 0 || last_nid == nid) {
5718 * Start with a mask granular enough to pin-point to the
5719 * start pfn and tick off bits one-by-one until it becomes
5720 * too coarse to separate the current node from the last.
5722 mask = ~((1 << __ffs(start)) - 1);
5723 while (mask && last_end <= (start & (mask << 1)))
5726 /* accumulate all internode masks */
5730 /* convert mask to number of pages */
5731 return ~accl_mask + 1;
5734 /* Find the lowest pfn for a node */
5735 static unsigned long __init find_min_pfn_for_node(int nid)
5737 unsigned long min_pfn = ULONG_MAX;
5738 unsigned long start_pfn;
5741 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5742 min_pfn = min(min_pfn, start_pfn);
5744 if (min_pfn == ULONG_MAX) {
5745 pr_warn("Could not find start_pfn for node %d\n", nid);
5753 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5755 * It returns the minimum PFN based on information provided via
5756 * memblock_set_node().
5758 unsigned long __init find_min_pfn_with_active_regions(void)
5760 return find_min_pfn_for_node(MAX_NUMNODES);
5764 * early_calculate_totalpages()
5765 * Sum pages in active regions for movable zone.
5766 * Populate N_MEMORY for calculating usable_nodes.
5768 static unsigned long __init early_calculate_totalpages(void)
5770 unsigned long totalpages = 0;
5771 unsigned long start_pfn, end_pfn;
5774 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5775 unsigned long pages = end_pfn - start_pfn;
5777 totalpages += pages;
5779 node_set_state(nid, N_MEMORY);
5785 * Find the PFN the Movable zone begins in each node. Kernel memory
5786 * is spread evenly between nodes as long as the nodes have enough
5787 * memory. When they don't, some nodes will have more kernelcore than
5790 static void __init find_zone_movable_pfns_for_nodes(void)
5793 unsigned long usable_startpfn;
5794 unsigned long kernelcore_node, kernelcore_remaining;
5795 /* save the state before borrow the nodemask */
5796 nodemask_t saved_node_state = node_states[N_MEMORY];
5797 unsigned long totalpages = early_calculate_totalpages();
5798 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5799 struct memblock_region *r;
5801 /* Need to find movable_zone earlier when movable_node is specified. */
5802 find_usable_zone_for_movable();
5805 * If movable_node is specified, ignore kernelcore and movablecore
5808 if (movable_node_is_enabled()) {
5809 for_each_memblock(memory, r) {
5810 if (!memblock_is_hotpluggable(r))
5815 usable_startpfn = PFN_DOWN(r->base);
5816 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5817 min(usable_startpfn, zone_movable_pfn[nid]) :
5825 * If kernelcore=mirror is specified, ignore movablecore option
5827 if (mirrored_kernelcore) {
5828 bool mem_below_4gb_not_mirrored = false;
5830 for_each_memblock(memory, r) {
5831 if (memblock_is_mirror(r))
5836 usable_startpfn = memblock_region_memory_base_pfn(r);
5838 if (usable_startpfn < 0x100000) {
5839 mem_below_4gb_not_mirrored = true;
5843 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5844 min(usable_startpfn, zone_movable_pfn[nid]) :
5848 if (mem_below_4gb_not_mirrored)
5849 pr_warn("This configuration results in unmirrored kernel memory.");
5855 * If movablecore=nn[KMG] was specified, calculate what size of
5856 * kernelcore that corresponds so that memory usable for
5857 * any allocation type is evenly spread. If both kernelcore
5858 * and movablecore are specified, then the value of kernelcore
5859 * will be used for required_kernelcore if it's greater than
5860 * what movablecore would have allowed.
5862 if (required_movablecore) {
5863 unsigned long corepages;
5866 * Round-up so that ZONE_MOVABLE is at least as large as what
5867 * was requested by the user
5869 required_movablecore =
5870 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5871 required_movablecore = min(totalpages, required_movablecore);
5872 corepages = totalpages - required_movablecore;
5874 required_kernelcore = max(required_kernelcore, corepages);
5878 * If kernelcore was not specified or kernelcore size is larger
5879 * than totalpages, there is no ZONE_MOVABLE.
5881 if (!required_kernelcore || required_kernelcore >= totalpages)
5884 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5885 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5888 /* Spread kernelcore memory as evenly as possible throughout nodes */
5889 kernelcore_node = required_kernelcore / usable_nodes;
5890 for_each_node_state(nid, N_MEMORY) {
5891 unsigned long start_pfn, end_pfn;
5894 * Recalculate kernelcore_node if the division per node
5895 * now exceeds what is necessary to satisfy the requested
5896 * amount of memory for the kernel
5898 if (required_kernelcore < kernelcore_node)
5899 kernelcore_node = required_kernelcore / usable_nodes;
5902 * As the map is walked, we track how much memory is usable
5903 * by the kernel using kernelcore_remaining. When it is
5904 * 0, the rest of the node is usable by ZONE_MOVABLE
5906 kernelcore_remaining = kernelcore_node;
5908 /* Go through each range of PFNs within this node */
5909 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5910 unsigned long size_pages;
5912 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5913 if (start_pfn >= end_pfn)
5916 /* Account for what is only usable for kernelcore */
5917 if (start_pfn < usable_startpfn) {
5918 unsigned long kernel_pages;
5919 kernel_pages = min(end_pfn, usable_startpfn)
5922 kernelcore_remaining -= min(kernel_pages,
5923 kernelcore_remaining);
5924 required_kernelcore -= min(kernel_pages,
5925 required_kernelcore);
5927 /* Continue if range is now fully accounted */
5928 if (end_pfn <= usable_startpfn) {
5931 * Push zone_movable_pfn to the end so
5932 * that if we have to rebalance
5933 * kernelcore across nodes, we will
5934 * not double account here
5936 zone_movable_pfn[nid] = end_pfn;
5939 start_pfn = usable_startpfn;
5943 * The usable PFN range for ZONE_MOVABLE is from
5944 * start_pfn->end_pfn. Calculate size_pages as the
5945 * number of pages used as kernelcore
5947 size_pages = end_pfn - start_pfn;
5948 if (size_pages > kernelcore_remaining)
5949 size_pages = kernelcore_remaining;
5950 zone_movable_pfn[nid] = start_pfn + size_pages;
5953 * Some kernelcore has been met, update counts and
5954 * break if the kernelcore for this node has been
5957 required_kernelcore -= min(required_kernelcore,
5959 kernelcore_remaining -= size_pages;
5960 if (!kernelcore_remaining)
5966 * If there is still required_kernelcore, we do another pass with one
5967 * less node in the count. This will push zone_movable_pfn[nid] further
5968 * along on the nodes that still have memory until kernelcore is
5972 if (usable_nodes && required_kernelcore > usable_nodes)
5976 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5977 for (nid = 0; nid < MAX_NUMNODES; nid++)
5978 zone_movable_pfn[nid] =
5979 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5982 /* restore the node_state */
5983 node_states[N_MEMORY] = saved_node_state;
5986 /* Any regular or high memory on that node ? */
5987 static void check_for_memory(pg_data_t *pgdat, int nid)
5989 enum zone_type zone_type;
5991 if (N_MEMORY == N_NORMAL_MEMORY)
5994 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5995 struct zone *zone = &pgdat->node_zones[zone_type];
5996 if (populated_zone(zone)) {
5997 node_set_state(nid, N_HIGH_MEMORY);
5998 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5999 zone_type <= ZONE_NORMAL)
6000 node_set_state(nid, N_NORMAL_MEMORY);
6007 * free_area_init_nodes - Initialise all pg_data_t and zone data
6008 * @max_zone_pfn: an array of max PFNs for each zone
6010 * This will call free_area_init_node() for each active node in the system.
6011 * Using the page ranges provided by memblock_set_node(), the size of each
6012 * zone in each node and their holes is calculated. If the maximum PFN
6013 * between two adjacent zones match, it is assumed that the zone is empty.
6014 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6015 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6016 * starts where the previous one ended. For example, ZONE_DMA32 starts
6017 * at arch_max_dma_pfn.
6019 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6021 unsigned long start_pfn, end_pfn;
6024 /* Record where the zone boundaries are */
6025 memset(arch_zone_lowest_possible_pfn, 0,
6026 sizeof(arch_zone_lowest_possible_pfn));
6027 memset(arch_zone_highest_possible_pfn, 0,
6028 sizeof(arch_zone_highest_possible_pfn));
6029 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
6030 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
6031 for (i = 1; i < MAX_NR_ZONES; i++) {
6032 if (i == ZONE_MOVABLE)
6034 arch_zone_lowest_possible_pfn[i] =
6035 arch_zone_highest_possible_pfn[i-1];
6036 arch_zone_highest_possible_pfn[i] =
6037 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
6039 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6040 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6042 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6043 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6044 find_zone_movable_pfns_for_nodes();
6046 /* Print out the zone ranges */
6047 pr_info("Zone ranges:\n");
6048 for (i = 0; i < MAX_NR_ZONES; i++) {
6049 if (i == ZONE_MOVABLE)
6051 pr_info(" %-8s ", zone_names[i]);
6052 if (arch_zone_lowest_possible_pfn[i] ==
6053 arch_zone_highest_possible_pfn[i])
6056 pr_cont("[mem %#018Lx-%#018Lx]\n",
6057 (u64)arch_zone_lowest_possible_pfn[i]
6059 ((u64)arch_zone_highest_possible_pfn[i]
6060 << PAGE_SHIFT) - 1);
6063 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6064 pr_info("Movable zone start for each node\n");
6065 for (i = 0; i < MAX_NUMNODES; i++) {
6066 if (zone_movable_pfn[i])
6067 pr_info(" Node %d: %#018Lx\n", i,
6068 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6071 /* Print out the early node map */
6072 pr_info("Early memory node ranges\n");
6073 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6074 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6075 (u64)start_pfn << PAGE_SHIFT,
6076 ((u64)end_pfn << PAGE_SHIFT) - 1);
6078 /* Initialise every node */
6079 mminit_verify_pageflags_layout();
6080 setup_nr_node_ids();
6081 for_each_online_node(nid) {
6082 pg_data_t *pgdat = NODE_DATA(nid);
6083 free_area_init_node(nid, NULL,
6084 find_min_pfn_for_node(nid), NULL);
6086 /* Any memory on that node */
6087 if (pgdat->node_present_pages)
6088 node_set_state(nid, N_MEMORY);
6089 check_for_memory(pgdat, nid);
6093 static int __init cmdline_parse_core(char *p, unsigned long *core)
6095 unsigned long long coremem;
6099 coremem = memparse(p, &p);
6100 *core = coremem >> PAGE_SHIFT;
6102 /* Paranoid check that UL is enough for the coremem value */
6103 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6109 * kernelcore=size sets the amount of memory for use for allocations that
6110 * cannot be reclaimed or migrated.
6112 static int __init cmdline_parse_kernelcore(char *p)
6114 /* parse kernelcore=mirror */
6115 if (parse_option_str(p, "mirror")) {
6116 mirrored_kernelcore = true;
6120 return cmdline_parse_core(p, &required_kernelcore);
6124 * movablecore=size sets the amount of memory for use for allocations that
6125 * can be reclaimed or migrated.
6127 static int __init cmdline_parse_movablecore(char *p)
6129 return cmdline_parse_core(p, &required_movablecore);
6132 early_param("kernelcore", cmdline_parse_kernelcore);
6133 early_param("movablecore", cmdline_parse_movablecore);
6135 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6137 void adjust_managed_page_count(struct page *page, long count)
6139 spin_lock(&managed_page_count_lock);
6140 page_zone(page)->managed_pages += count;
6141 totalram_pages += count;
6142 #ifdef CONFIG_HIGHMEM
6143 if (PageHighMem(page))
6144 totalhigh_pages += count;
6146 spin_unlock(&managed_page_count_lock);
6148 EXPORT_SYMBOL(adjust_managed_page_count);
6150 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6153 unsigned long pages = 0;
6155 start = (void *)PAGE_ALIGN((unsigned long)start);
6156 end = (void *)((unsigned long)end & PAGE_MASK);
6157 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6158 if ((unsigned int)poison <= 0xFF)
6159 memset(pos, poison, PAGE_SIZE);
6160 free_reserved_page(virt_to_page(pos));
6164 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6165 s, pages << (PAGE_SHIFT - 10), start, end);
6169 EXPORT_SYMBOL(free_reserved_area);
6171 #ifdef CONFIG_HIGHMEM
6172 void free_highmem_page(struct page *page)
6174 __free_reserved_page(page);
6176 page_zone(page)->managed_pages++;
6182 void __init mem_init_print_info(const char *str)
6184 unsigned long physpages, codesize, datasize, rosize, bss_size;
6185 unsigned long init_code_size, init_data_size;
6187 physpages = get_num_physpages();
6188 codesize = _etext - _stext;
6189 datasize = _edata - _sdata;
6190 rosize = __end_rodata - __start_rodata;
6191 bss_size = __bss_stop - __bss_start;
6192 init_data_size = __init_end - __init_begin;
6193 init_code_size = _einittext - _sinittext;
6196 * Detect special cases and adjust section sizes accordingly:
6197 * 1) .init.* may be embedded into .data sections
6198 * 2) .init.text.* may be out of [__init_begin, __init_end],
6199 * please refer to arch/tile/kernel/vmlinux.lds.S.
6200 * 3) .rodata.* may be embedded into .text or .data sections.
6202 #define adj_init_size(start, end, size, pos, adj) \
6204 if (start <= pos && pos < end && size > adj) \
6208 adj_init_size(__init_begin, __init_end, init_data_size,
6209 _sinittext, init_code_size);
6210 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6211 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6212 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6213 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6215 #undef adj_init_size
6217 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6218 #ifdef CONFIG_HIGHMEM
6222 nr_free_pages() << (PAGE_SHIFT - 10),
6223 physpages << (PAGE_SHIFT - 10),
6224 codesize >> 10, datasize >> 10, rosize >> 10,
6225 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6226 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6227 totalcma_pages << (PAGE_SHIFT - 10),
6228 #ifdef CONFIG_HIGHMEM
6229 totalhigh_pages << (PAGE_SHIFT - 10),
6231 str ? ", " : "", str ? str : "");
6235 * set_dma_reserve - set the specified number of pages reserved in the first zone
6236 * @new_dma_reserve: The number of pages to mark reserved
6238 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6239 * In the DMA zone, a significant percentage may be consumed by kernel image
6240 * and other unfreeable allocations which can skew the watermarks badly. This
6241 * function may optionally be used to account for unfreeable pages in the
6242 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6243 * smaller per-cpu batchsize.
6245 void __init set_dma_reserve(unsigned long new_dma_reserve)
6247 dma_reserve = new_dma_reserve;
6250 void __init free_area_init(unsigned long *zones_size)
6252 free_area_init_node(0, zones_size,
6253 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6256 static int page_alloc_cpu_notify(struct notifier_block *self,
6257 unsigned long action, void *hcpu)
6259 int cpu = (unsigned long)hcpu;
6261 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6262 lru_add_drain_cpu(cpu);
6266 * Spill the event counters of the dead processor
6267 * into the current processors event counters.
6268 * This artificially elevates the count of the current
6271 vm_events_fold_cpu(cpu);
6274 * Zero the differential counters of the dead processor
6275 * so that the vm statistics are consistent.
6277 * This is only okay since the processor is dead and cannot
6278 * race with what we are doing.
6280 cpu_vm_stats_fold(cpu);
6285 void __init page_alloc_init(void)
6287 hotcpu_notifier(page_alloc_cpu_notify, 0);
6291 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6292 * or min_free_kbytes changes.
6294 static void calculate_totalreserve_pages(void)
6296 struct pglist_data *pgdat;
6297 unsigned long reserve_pages = 0;
6298 enum zone_type i, j;
6300 for_each_online_pgdat(pgdat) {
6301 for (i = 0; i < MAX_NR_ZONES; i++) {
6302 struct zone *zone = pgdat->node_zones + i;
6305 /* Find valid and maximum lowmem_reserve in the zone */
6306 for (j = i; j < MAX_NR_ZONES; j++) {
6307 if (zone->lowmem_reserve[j] > max)
6308 max = zone->lowmem_reserve[j];
6311 /* we treat the high watermark as reserved pages. */
6312 max += high_wmark_pages(zone);
6314 if (max > zone->managed_pages)
6315 max = zone->managed_pages;
6317 zone->totalreserve_pages = max;
6319 reserve_pages += max;
6322 totalreserve_pages = reserve_pages;
6326 * setup_per_zone_lowmem_reserve - called whenever
6327 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6328 * has a correct pages reserved value, so an adequate number of
6329 * pages are left in the zone after a successful __alloc_pages().
6331 static void setup_per_zone_lowmem_reserve(void)
6333 struct pglist_data *pgdat;
6334 enum zone_type j, idx;
6336 for_each_online_pgdat(pgdat) {
6337 for (j = 0; j < MAX_NR_ZONES; j++) {
6338 struct zone *zone = pgdat->node_zones + j;
6339 unsigned long managed_pages = zone->managed_pages;
6341 zone->lowmem_reserve[j] = 0;
6345 struct zone *lower_zone;
6349 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6350 sysctl_lowmem_reserve_ratio[idx] = 1;
6352 lower_zone = pgdat->node_zones + idx;
6353 lower_zone->lowmem_reserve[j] = managed_pages /
6354 sysctl_lowmem_reserve_ratio[idx];
6355 managed_pages += lower_zone->managed_pages;
6360 /* update totalreserve_pages */
6361 calculate_totalreserve_pages();
6364 static void __setup_per_zone_wmarks(void)
6366 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6367 unsigned long lowmem_pages = 0;
6369 unsigned long flags;
6371 /* Calculate total number of !ZONE_HIGHMEM pages */
6372 for_each_zone(zone) {
6373 if (!is_highmem(zone))
6374 lowmem_pages += zone->managed_pages;
6377 for_each_zone(zone) {
6380 spin_lock_irqsave(&zone->lock, flags);
6381 tmp = (u64)pages_min * zone->managed_pages;
6382 do_div(tmp, lowmem_pages);
6383 if (is_highmem(zone)) {
6385 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6386 * need highmem pages, so cap pages_min to a small
6389 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6390 * deltas control asynch page reclaim, and so should
6391 * not be capped for highmem.
6393 unsigned long min_pages;
6395 min_pages = zone->managed_pages / 1024;
6396 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6397 zone->watermark[WMARK_MIN] = min_pages;
6400 * If it's a lowmem zone, reserve a number of pages
6401 * proportionate to the zone's size.
6403 zone->watermark[WMARK_MIN] = tmp;
6407 * Set the kswapd watermarks distance according to the
6408 * scale factor in proportion to available memory, but
6409 * ensure a minimum size on small systems.
6411 tmp = max_t(u64, tmp >> 2,
6412 mult_frac(zone->managed_pages,
6413 watermark_scale_factor, 10000));
6415 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6416 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6418 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6419 high_wmark_pages(zone) - low_wmark_pages(zone) -
6420 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6422 spin_unlock_irqrestore(&zone->lock, flags);
6425 /* update totalreserve_pages */
6426 calculate_totalreserve_pages();
6430 * setup_per_zone_wmarks - called when min_free_kbytes changes
6431 * or when memory is hot-{added|removed}
6433 * Ensures that the watermark[min,low,high] values for each zone are set
6434 * correctly with respect to min_free_kbytes.
6436 void setup_per_zone_wmarks(void)
6438 mutex_lock(&zonelists_mutex);
6439 __setup_per_zone_wmarks();
6440 mutex_unlock(&zonelists_mutex);
6444 * The inactive anon list should be small enough that the VM never has to
6445 * do too much work, but large enough that each inactive page has a chance
6446 * to be referenced again before it is swapped out.
6448 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6449 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6450 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6451 * the anonymous pages are kept on the inactive list.
6454 * memory ratio inactive anon
6455 * -------------------------------------
6464 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6466 unsigned int gb, ratio;
6468 /* Zone size in gigabytes */
6469 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6471 ratio = int_sqrt(10 * gb);
6475 zone->inactive_ratio = ratio;
6478 static void __meminit setup_per_zone_inactive_ratio(void)
6483 calculate_zone_inactive_ratio(zone);
6487 * Initialise min_free_kbytes.
6489 * For small machines we want it small (128k min). For large machines
6490 * we want it large (64MB max). But it is not linear, because network
6491 * bandwidth does not increase linearly with machine size. We use
6493 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6494 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6510 int __meminit init_per_zone_wmark_min(void)
6512 unsigned long lowmem_kbytes;
6513 int new_min_free_kbytes;
6515 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6516 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6518 if (new_min_free_kbytes > user_min_free_kbytes) {
6519 min_free_kbytes = new_min_free_kbytes;
6520 if (min_free_kbytes < 128)
6521 min_free_kbytes = 128;
6522 if (min_free_kbytes > 65536)
6523 min_free_kbytes = 65536;
6525 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6526 new_min_free_kbytes, user_min_free_kbytes);
6528 setup_per_zone_wmarks();
6529 refresh_zone_stat_thresholds();
6530 setup_per_zone_lowmem_reserve();
6531 setup_per_zone_inactive_ratio();
6534 core_initcall(init_per_zone_wmark_min)
6537 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6538 * that we can call two helper functions whenever min_free_kbytes
6541 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6542 void __user *buffer, size_t *length, loff_t *ppos)
6546 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6551 user_min_free_kbytes = min_free_kbytes;
6552 setup_per_zone_wmarks();
6557 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6558 void __user *buffer, size_t *length, loff_t *ppos)
6562 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6567 setup_per_zone_wmarks();
6573 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6574 void __user *buffer, size_t *length, loff_t *ppos)
6579 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6584 zone->min_unmapped_pages = (zone->managed_pages *
6585 sysctl_min_unmapped_ratio) / 100;
6589 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6590 void __user *buffer, size_t *length, loff_t *ppos)
6595 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6600 zone->min_slab_pages = (zone->managed_pages *
6601 sysctl_min_slab_ratio) / 100;
6607 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6608 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6609 * whenever sysctl_lowmem_reserve_ratio changes.
6611 * The reserve ratio obviously has absolutely no relation with the
6612 * minimum watermarks. The lowmem reserve ratio can only make sense
6613 * if in function of the boot time zone sizes.
6615 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6616 void __user *buffer, size_t *length, loff_t *ppos)
6618 proc_dointvec_minmax(table, write, buffer, length, ppos);
6619 setup_per_zone_lowmem_reserve();
6624 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6625 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6626 * pagelist can have before it gets flushed back to buddy allocator.
6628 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6629 void __user *buffer, size_t *length, loff_t *ppos)
6632 int old_percpu_pagelist_fraction;
6635 mutex_lock(&pcp_batch_high_lock);
6636 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6638 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6639 if (!write || ret < 0)
6642 /* Sanity checking to avoid pcp imbalance */
6643 if (percpu_pagelist_fraction &&
6644 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6645 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6651 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6654 for_each_populated_zone(zone) {
6657 for_each_possible_cpu(cpu)
6658 pageset_set_high_and_batch(zone,
6659 per_cpu_ptr(zone->pageset, cpu));
6662 mutex_unlock(&pcp_batch_high_lock);
6667 int hashdist = HASHDIST_DEFAULT;
6669 static int __init set_hashdist(char *str)
6673 hashdist = simple_strtoul(str, &str, 0);
6676 __setup("hashdist=", set_hashdist);
6680 * allocate a large system hash table from bootmem
6681 * - it is assumed that the hash table must contain an exact power-of-2
6682 * quantity of entries
6683 * - limit is the number of hash buckets, not the total allocation size
6685 void *__init alloc_large_system_hash(const char *tablename,
6686 unsigned long bucketsize,
6687 unsigned long numentries,
6690 unsigned int *_hash_shift,
6691 unsigned int *_hash_mask,
6692 unsigned long low_limit,
6693 unsigned long high_limit)
6695 unsigned long long max = high_limit;
6696 unsigned long log2qty, size;
6699 /* allow the kernel cmdline to have a say */
6701 /* round applicable memory size up to nearest megabyte */
6702 numentries = nr_kernel_pages;
6704 /* It isn't necessary when PAGE_SIZE >= 1MB */
6705 if (PAGE_SHIFT < 20)
6706 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6708 /* limit to 1 bucket per 2^scale bytes of low memory */
6709 if (scale > PAGE_SHIFT)
6710 numentries >>= (scale - PAGE_SHIFT);
6712 numentries <<= (PAGE_SHIFT - scale);
6714 /* Make sure we've got at least a 0-order allocation.. */
6715 if (unlikely(flags & HASH_SMALL)) {
6716 /* Makes no sense without HASH_EARLY */
6717 WARN_ON(!(flags & HASH_EARLY));
6718 if (!(numentries >> *_hash_shift)) {
6719 numentries = 1UL << *_hash_shift;
6720 BUG_ON(!numentries);
6722 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6723 numentries = PAGE_SIZE / bucketsize;
6725 numentries = roundup_pow_of_two(numentries);
6727 /* limit allocation size to 1/16 total memory by default */
6729 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6730 do_div(max, bucketsize);
6732 max = min(max, 0x80000000ULL);
6734 if (numentries < low_limit)
6735 numentries = low_limit;
6736 if (numentries > max)
6739 log2qty = ilog2(numentries);
6742 size = bucketsize << log2qty;
6743 if (flags & HASH_EARLY)
6744 table = memblock_virt_alloc_nopanic(size, 0);
6746 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6749 * If bucketsize is not a power-of-two, we may free
6750 * some pages at the end of hash table which
6751 * alloc_pages_exact() automatically does
6753 if (get_order(size) < MAX_ORDER) {
6754 table = alloc_pages_exact(size, GFP_ATOMIC);
6755 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6758 } while (!table && size > PAGE_SIZE && --log2qty);
6761 panic("Failed to allocate %s hash table\n", tablename);
6763 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6764 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
6767 *_hash_shift = log2qty;
6769 *_hash_mask = (1 << log2qty) - 1;
6774 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6775 static inline unsigned long *get_pageblock_bitmap(struct page *page,
6778 #ifdef CONFIG_SPARSEMEM
6779 return __pfn_to_section(pfn)->pageblock_flags;
6781 return page_zone(page)->pageblock_flags;
6782 #endif /* CONFIG_SPARSEMEM */
6785 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
6787 #ifdef CONFIG_SPARSEMEM
6788 pfn &= (PAGES_PER_SECTION-1);
6789 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6791 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
6792 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6793 #endif /* CONFIG_SPARSEMEM */
6797 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6798 * @page: The page within the block of interest
6799 * @pfn: The target page frame number
6800 * @end_bitidx: The last bit of interest to retrieve
6801 * @mask: mask of bits that the caller is interested in
6803 * Return: pageblock_bits flags
6805 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6806 unsigned long end_bitidx,
6809 unsigned long *bitmap;
6810 unsigned long bitidx, word_bitidx;
6813 bitmap = get_pageblock_bitmap(page, pfn);
6814 bitidx = pfn_to_bitidx(page, pfn);
6815 word_bitidx = bitidx / BITS_PER_LONG;
6816 bitidx &= (BITS_PER_LONG-1);
6818 word = bitmap[word_bitidx];
6819 bitidx += end_bitidx;
6820 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6824 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6825 * @page: The page within the block of interest
6826 * @flags: The flags to set
6827 * @pfn: The target page frame number
6828 * @end_bitidx: The last bit of interest
6829 * @mask: mask of bits that the caller is interested in
6831 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6833 unsigned long end_bitidx,
6836 unsigned long *bitmap;
6837 unsigned long bitidx, word_bitidx;
6838 unsigned long old_word, word;
6840 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6842 bitmap = get_pageblock_bitmap(page, pfn);
6843 bitidx = pfn_to_bitidx(page, pfn);
6844 word_bitidx = bitidx / BITS_PER_LONG;
6845 bitidx &= (BITS_PER_LONG-1);
6847 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
6849 bitidx += end_bitidx;
6850 mask <<= (BITS_PER_LONG - bitidx - 1);
6851 flags <<= (BITS_PER_LONG - bitidx - 1);
6853 word = READ_ONCE(bitmap[word_bitidx]);
6855 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6856 if (word == old_word)
6863 * This function checks whether pageblock includes unmovable pages or not.
6864 * If @count is not zero, it is okay to include less @count unmovable pages
6866 * PageLRU check without isolation or lru_lock could race so that
6867 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6868 * expect this function should be exact.
6870 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6871 bool skip_hwpoisoned_pages)
6873 unsigned long pfn, iter, found;
6877 * For avoiding noise data, lru_add_drain_all() should be called
6878 * If ZONE_MOVABLE, the zone never contains unmovable pages
6880 if (zone_idx(zone) == ZONE_MOVABLE)
6882 mt = get_pageblock_migratetype(page);
6883 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6886 pfn = page_to_pfn(page);
6887 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6888 unsigned long check = pfn + iter;
6890 if (!pfn_valid_within(check))
6893 page = pfn_to_page(check);
6896 * Hugepages are not in LRU lists, but they're movable.
6897 * We need not scan over tail pages bacause we don't
6898 * handle each tail page individually in migration.
6900 if (PageHuge(page)) {
6901 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6906 * We can't use page_count without pin a page
6907 * because another CPU can free compound page.
6908 * This check already skips compound tails of THP
6909 * because their page->_refcount is zero at all time.
6911 if (!page_ref_count(page)) {
6912 if (PageBuddy(page))
6913 iter += (1 << page_order(page)) - 1;
6918 * The HWPoisoned page may be not in buddy system, and
6919 * page_count() is not 0.
6921 if (skip_hwpoisoned_pages && PageHWPoison(page))
6927 * If there are RECLAIMABLE pages, we need to check
6928 * it. But now, memory offline itself doesn't call
6929 * shrink_node_slabs() and it still to be fixed.
6932 * If the page is not RAM, page_count()should be 0.
6933 * we don't need more check. This is an _used_ not-movable page.
6935 * The problematic thing here is PG_reserved pages. PG_reserved
6936 * is set to both of a memory hole page and a _used_ kernel
6945 bool is_pageblock_removable_nolock(struct page *page)
6951 * We have to be careful here because we are iterating over memory
6952 * sections which are not zone aware so we might end up outside of
6953 * the zone but still within the section.
6954 * We have to take care about the node as well. If the node is offline
6955 * its NODE_DATA will be NULL - see page_zone.
6957 if (!node_online(page_to_nid(page)))
6960 zone = page_zone(page);
6961 pfn = page_to_pfn(page);
6962 if (!zone_spans_pfn(zone, pfn))
6965 return !has_unmovable_pages(zone, page, 0, true);
6968 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6970 static unsigned long pfn_max_align_down(unsigned long pfn)
6972 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6973 pageblock_nr_pages) - 1);
6976 static unsigned long pfn_max_align_up(unsigned long pfn)
6978 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6979 pageblock_nr_pages));
6982 /* [start, end) must belong to a single zone. */
6983 static int __alloc_contig_migrate_range(struct compact_control *cc,
6984 unsigned long start, unsigned long end)
6986 /* This function is based on compact_zone() from compaction.c. */
6987 unsigned long nr_reclaimed;
6988 unsigned long pfn = start;
6989 unsigned int tries = 0;
6994 while (pfn < end || !list_empty(&cc->migratepages)) {
6995 if (fatal_signal_pending(current)) {
7000 if (list_empty(&cc->migratepages)) {
7001 cc->nr_migratepages = 0;
7002 pfn = isolate_migratepages_range(cc, pfn, end);
7008 } else if (++tries == 5) {
7009 ret = ret < 0 ? ret : -EBUSY;
7013 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7015 cc->nr_migratepages -= nr_reclaimed;
7017 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7018 NULL, 0, cc->mode, MR_CMA);
7021 putback_movable_pages(&cc->migratepages);
7028 * alloc_contig_range() -- tries to allocate given range of pages
7029 * @start: start PFN to allocate
7030 * @end: one-past-the-last PFN to allocate
7031 * @migratetype: migratetype of the underlaying pageblocks (either
7032 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7033 * in range must have the same migratetype and it must
7034 * be either of the two.
7036 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7037 * aligned, however it's the caller's responsibility to guarantee that
7038 * we are the only thread that changes migrate type of pageblocks the
7041 * The PFN range must belong to a single zone.
7043 * Returns zero on success or negative error code. On success all
7044 * pages which PFN is in [start, end) are allocated for the caller and
7045 * need to be freed with free_contig_range().
7047 int alloc_contig_range(unsigned long start, unsigned long end,
7048 unsigned migratetype)
7050 unsigned long outer_start, outer_end;
7054 struct compact_control cc = {
7055 .nr_migratepages = 0,
7057 .zone = page_zone(pfn_to_page(start)),
7058 .mode = MIGRATE_SYNC,
7059 .ignore_skip_hint = true,
7061 INIT_LIST_HEAD(&cc.migratepages);
7064 * What we do here is we mark all pageblocks in range as
7065 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7066 * have different sizes, and due to the way page allocator
7067 * work, we align the range to biggest of the two pages so
7068 * that page allocator won't try to merge buddies from
7069 * different pageblocks and change MIGRATE_ISOLATE to some
7070 * other migration type.
7072 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7073 * migrate the pages from an unaligned range (ie. pages that
7074 * we are interested in). This will put all the pages in
7075 * range back to page allocator as MIGRATE_ISOLATE.
7077 * When this is done, we take the pages in range from page
7078 * allocator removing them from the buddy system. This way
7079 * page allocator will never consider using them.
7081 * This lets us mark the pageblocks back as
7082 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7083 * aligned range but not in the unaligned, original range are
7084 * put back to page allocator so that buddy can use them.
7087 ret = start_isolate_page_range(pfn_max_align_down(start),
7088 pfn_max_align_up(end), migratetype,
7094 * In case of -EBUSY, we'd like to know which page causes problem.
7095 * So, just fall through. We will check it in test_pages_isolated().
7097 ret = __alloc_contig_migrate_range(&cc, start, end);
7098 if (ret && ret != -EBUSY)
7102 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7103 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7104 * more, all pages in [start, end) are free in page allocator.
7105 * What we are going to do is to allocate all pages from
7106 * [start, end) (that is remove them from page allocator).
7108 * The only problem is that pages at the beginning and at the
7109 * end of interesting range may be not aligned with pages that
7110 * page allocator holds, ie. they can be part of higher order
7111 * pages. Because of this, we reserve the bigger range and
7112 * once this is done free the pages we are not interested in.
7114 * We don't have to hold zone->lock here because the pages are
7115 * isolated thus they won't get removed from buddy.
7118 lru_add_drain_all();
7119 drain_all_pages(cc.zone);
7122 outer_start = start;
7123 while (!PageBuddy(pfn_to_page(outer_start))) {
7124 if (++order >= MAX_ORDER) {
7125 outer_start = start;
7128 outer_start &= ~0UL << order;
7131 if (outer_start != start) {
7132 order = page_order(pfn_to_page(outer_start));
7135 * outer_start page could be small order buddy page and
7136 * it doesn't include start page. Adjust outer_start
7137 * in this case to report failed page properly
7138 * on tracepoint in test_pages_isolated()
7140 if (outer_start + (1UL << order) <= start)
7141 outer_start = start;
7144 /* Make sure the range is really isolated. */
7145 if (test_pages_isolated(outer_start, end, false)) {
7146 pr_info("%s: [%lx, %lx) PFNs busy\n",
7147 __func__, outer_start, end);
7152 /* Grab isolated pages from freelists. */
7153 outer_end = isolate_freepages_range(&cc, outer_start, end);
7159 /* Free head and tail (if any) */
7160 if (start != outer_start)
7161 free_contig_range(outer_start, start - outer_start);
7162 if (end != outer_end)
7163 free_contig_range(end, outer_end - end);
7166 undo_isolate_page_range(pfn_max_align_down(start),
7167 pfn_max_align_up(end), migratetype);
7171 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7173 unsigned int count = 0;
7175 for (; nr_pages--; pfn++) {
7176 struct page *page = pfn_to_page(pfn);
7178 count += page_count(page) != 1;
7181 WARN(count != 0, "%d pages are still in use!\n", count);
7185 #ifdef CONFIG_MEMORY_HOTPLUG
7187 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7188 * page high values need to be recalulated.
7190 void __meminit zone_pcp_update(struct zone *zone)
7193 mutex_lock(&pcp_batch_high_lock);
7194 for_each_possible_cpu(cpu)
7195 pageset_set_high_and_batch(zone,
7196 per_cpu_ptr(zone->pageset, cpu));
7197 mutex_unlock(&pcp_batch_high_lock);
7201 void zone_pcp_reset(struct zone *zone)
7203 unsigned long flags;
7205 struct per_cpu_pageset *pset;
7207 /* avoid races with drain_pages() */
7208 local_irq_save(flags);
7209 if (zone->pageset != &boot_pageset) {
7210 for_each_online_cpu(cpu) {
7211 pset = per_cpu_ptr(zone->pageset, cpu);
7212 drain_zonestat(zone, pset);
7214 free_percpu(zone->pageset);
7215 zone->pageset = &boot_pageset;
7217 local_irq_restore(flags);
7220 #ifdef CONFIG_MEMORY_HOTREMOVE
7222 * All pages in the range must be in a single zone and isolated
7223 * before calling this.
7226 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7230 unsigned int order, i;
7232 unsigned long flags;
7233 /* find the first valid pfn */
7234 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7239 zone = page_zone(pfn_to_page(pfn));
7240 spin_lock_irqsave(&zone->lock, flags);
7242 while (pfn < end_pfn) {
7243 if (!pfn_valid(pfn)) {
7247 page = pfn_to_page(pfn);
7249 * The HWPoisoned page may be not in buddy system, and
7250 * page_count() is not 0.
7252 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7254 SetPageReserved(page);
7258 BUG_ON(page_count(page));
7259 BUG_ON(!PageBuddy(page));
7260 order = page_order(page);
7261 #ifdef CONFIG_DEBUG_VM
7262 pr_info("remove from free list %lx %d %lx\n",
7263 pfn, 1 << order, end_pfn);
7265 list_del(&page->lru);
7266 rmv_page_order(page);
7267 zone->free_area[order].nr_free--;
7268 for (i = 0; i < (1 << order); i++)
7269 SetPageReserved((page+i));
7270 pfn += (1 << order);
7272 spin_unlock_irqrestore(&zone->lock, flags);
7276 bool is_free_buddy_page(struct page *page)
7278 struct zone *zone = page_zone(page);
7279 unsigned long pfn = page_to_pfn(page);
7280 unsigned long flags;
7283 spin_lock_irqsave(&zone->lock, flags);
7284 for (order = 0; order < MAX_ORDER; order++) {
7285 struct page *page_head = page - (pfn & ((1 << order) - 1));
7287 if (PageBuddy(page_head) && page_order(page_head) >= order)
7290 spin_unlock_irqrestore(&zone->lock, flags);
7292 return order < MAX_ORDER;