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;
253 static unsigned long __meminitdata nr_kernel_pages;
254 static unsigned long __meminitdata nr_all_pages;
255 static unsigned long __meminitdata dma_reserve;
257 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
258 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
259 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
260 static unsigned long __initdata required_kernelcore;
261 static unsigned long __initdata required_movablecore;
262 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
263 static bool mirrored_kernelcore;
265 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
267 EXPORT_SYMBOL(movable_zone);
268 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
271 int nr_node_ids __read_mostly = MAX_NUMNODES;
272 int nr_online_nodes __read_mostly = 1;
273 EXPORT_SYMBOL(nr_node_ids);
274 EXPORT_SYMBOL(nr_online_nodes);
277 int page_group_by_mobility_disabled __read_mostly;
279 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
280 static inline void reset_deferred_meminit(pg_data_t *pgdat)
282 pgdat->first_deferred_pfn = ULONG_MAX;
285 /* Returns true if the struct page for the pfn is uninitialised */
286 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
288 if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn)
294 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
296 if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
303 * Returns false when the remaining initialisation should be deferred until
304 * later in the boot cycle when it can be parallelised.
306 static inline bool update_defer_init(pg_data_t *pgdat,
307 unsigned long pfn, unsigned long zone_end,
308 unsigned long *nr_initialised)
310 /* Always populate low zones for address-contrained allocations */
311 if (zone_end < pgdat_end_pfn(pgdat))
314 /* Initialise at least 2G of the highest zone */
316 if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) &&
317 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
318 pgdat->first_deferred_pfn = pfn;
325 static inline void reset_deferred_meminit(pg_data_t *pgdat)
329 static inline bool early_page_uninitialised(unsigned long pfn)
334 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
339 static inline bool update_defer_init(pg_data_t *pgdat,
340 unsigned long pfn, unsigned long zone_end,
341 unsigned long *nr_initialised)
348 void set_pageblock_migratetype(struct page *page, int migratetype)
350 if (unlikely(page_group_by_mobility_disabled &&
351 migratetype < MIGRATE_PCPTYPES))
352 migratetype = MIGRATE_UNMOVABLE;
354 set_pageblock_flags_group(page, (unsigned long)migratetype,
355 PB_migrate, PB_migrate_end);
358 #ifdef CONFIG_DEBUG_VM
359 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
363 unsigned long pfn = page_to_pfn(page);
364 unsigned long sp, start_pfn;
367 seq = zone_span_seqbegin(zone);
368 start_pfn = zone->zone_start_pfn;
369 sp = zone->spanned_pages;
370 if (!zone_spans_pfn(zone, pfn))
372 } while (zone_span_seqretry(zone, seq));
375 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
376 pfn, zone_to_nid(zone), zone->name,
377 start_pfn, start_pfn + sp);
382 static int page_is_consistent(struct zone *zone, struct page *page)
384 if (!pfn_valid_within(page_to_pfn(page)))
386 if (zone != page_zone(page))
392 * Temporary debugging check for pages not lying within a given zone.
394 static int bad_range(struct zone *zone, struct page *page)
396 if (page_outside_zone_boundaries(zone, page))
398 if (!page_is_consistent(zone, page))
404 static inline int bad_range(struct zone *zone, struct page *page)
410 static void bad_page(struct page *page, const char *reason,
411 unsigned long bad_flags)
413 static unsigned long resume;
414 static unsigned long nr_shown;
415 static unsigned long nr_unshown;
417 /* Don't complain about poisoned pages */
418 if (PageHWPoison(page)) {
419 page_mapcount_reset(page); /* remove PageBuddy */
424 * Allow a burst of 60 reports, then keep quiet for that minute;
425 * or allow a steady drip of one report per second.
427 if (nr_shown == 60) {
428 if (time_before(jiffies, resume)) {
434 "BUG: Bad page state: %lu messages suppressed\n",
441 resume = jiffies + 60 * HZ;
443 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
444 current->comm, page_to_pfn(page));
445 __dump_page(page, reason);
446 bad_flags &= page->flags;
448 pr_alert("bad because of flags: %#lx(%pGp)\n",
449 bad_flags, &bad_flags);
450 dump_page_owner(page);
455 /* Leave bad fields for debug, except PageBuddy could make trouble */
456 page_mapcount_reset(page); /* remove PageBuddy */
457 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
461 * Higher-order pages are called "compound pages". They are structured thusly:
463 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
465 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
466 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
468 * The first tail page's ->compound_dtor holds the offset in array of compound
469 * page destructors. See compound_page_dtors.
471 * The first tail page's ->compound_order holds the order of allocation.
472 * This usage means that zero-order pages may not be compound.
475 void free_compound_page(struct page *page)
477 __free_pages_ok(page, compound_order(page));
480 void prep_compound_page(struct page *page, unsigned int order)
483 int nr_pages = 1 << order;
485 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
486 set_compound_order(page, order);
488 for (i = 1; i < nr_pages; i++) {
489 struct page *p = page + i;
490 set_page_count(p, 0);
491 p->mapping = TAIL_MAPPING;
492 set_compound_head(p, page);
494 atomic_set(compound_mapcount_ptr(page), -1);
497 #ifdef CONFIG_DEBUG_PAGEALLOC
498 unsigned int _debug_guardpage_minorder;
499 bool _debug_pagealloc_enabled __read_mostly
500 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
501 EXPORT_SYMBOL(_debug_pagealloc_enabled);
502 bool _debug_guardpage_enabled __read_mostly;
504 static int __init early_debug_pagealloc(char *buf)
509 if (strcmp(buf, "on") == 0)
510 _debug_pagealloc_enabled = true;
512 if (strcmp(buf, "off") == 0)
513 _debug_pagealloc_enabled = false;
517 early_param("debug_pagealloc", early_debug_pagealloc);
519 static bool need_debug_guardpage(void)
521 /* If we don't use debug_pagealloc, we don't need guard page */
522 if (!debug_pagealloc_enabled())
528 static void init_debug_guardpage(void)
530 if (!debug_pagealloc_enabled())
533 _debug_guardpage_enabled = true;
536 struct page_ext_operations debug_guardpage_ops = {
537 .need = need_debug_guardpage,
538 .init = init_debug_guardpage,
541 static int __init debug_guardpage_minorder_setup(char *buf)
545 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
546 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
549 _debug_guardpage_minorder = res;
550 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
553 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
555 static inline void set_page_guard(struct zone *zone, struct page *page,
556 unsigned int order, int migratetype)
558 struct page_ext *page_ext;
560 if (!debug_guardpage_enabled())
563 page_ext = lookup_page_ext(page);
564 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
566 INIT_LIST_HEAD(&page->lru);
567 set_page_private(page, order);
568 /* Guard pages are not available for any usage */
569 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
572 static inline void clear_page_guard(struct zone *zone, struct page *page,
573 unsigned int order, int migratetype)
575 struct page_ext *page_ext;
577 if (!debug_guardpage_enabled())
580 page_ext = lookup_page_ext(page);
581 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
583 set_page_private(page, 0);
584 if (!is_migrate_isolate(migratetype))
585 __mod_zone_freepage_state(zone, (1 << order), migratetype);
588 struct page_ext_operations debug_guardpage_ops = { NULL, };
589 static inline void set_page_guard(struct zone *zone, struct page *page,
590 unsigned int order, int migratetype) {}
591 static inline void clear_page_guard(struct zone *zone, struct page *page,
592 unsigned int order, int migratetype) {}
595 static inline void set_page_order(struct page *page, unsigned int order)
597 set_page_private(page, order);
598 __SetPageBuddy(page);
601 static inline void rmv_page_order(struct page *page)
603 __ClearPageBuddy(page);
604 set_page_private(page, 0);
608 * This function checks whether a page is free && is the buddy
609 * we can do coalesce a page and its buddy if
610 * (a) the buddy is not in a hole &&
611 * (b) the buddy is in the buddy system &&
612 * (c) a page and its buddy have the same order &&
613 * (d) a page and its buddy are in the same zone.
615 * For recording whether a page is in the buddy system, we set ->_mapcount
616 * PAGE_BUDDY_MAPCOUNT_VALUE.
617 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
618 * serialized by zone->lock.
620 * For recording page's order, we use page_private(page).
622 static inline int page_is_buddy(struct page *page, struct page *buddy,
625 if (!pfn_valid_within(page_to_pfn(buddy)))
628 if (page_is_guard(buddy) && page_order(buddy) == order) {
629 if (page_zone_id(page) != page_zone_id(buddy))
632 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
637 if (PageBuddy(buddy) && page_order(buddy) == order) {
639 * zone check is done late to avoid uselessly
640 * calculating zone/node ids for pages that could
643 if (page_zone_id(page) != page_zone_id(buddy))
646 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
654 * Freeing function for a buddy system allocator.
656 * The concept of a buddy system is to maintain direct-mapped table
657 * (containing bit values) for memory blocks of various "orders".
658 * The bottom level table contains the map for the smallest allocatable
659 * units of memory (here, pages), and each level above it describes
660 * pairs of units from the levels below, hence, "buddies".
661 * At a high level, all that happens here is marking the table entry
662 * at the bottom level available, and propagating the changes upward
663 * as necessary, plus some accounting needed to play nicely with other
664 * parts of the VM system.
665 * At each level, we keep a list of pages, which are heads of continuous
666 * free pages of length of (1 << order) and marked with _mapcount
667 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
669 * So when we are allocating or freeing one, we can derive the state of the
670 * other. That is, if we allocate a small block, and both were
671 * free, the remainder of the region must be split into blocks.
672 * If a block is freed, and its buddy is also free, then this
673 * triggers coalescing into a block of larger size.
678 static inline void __free_one_page(struct page *page,
680 struct zone *zone, unsigned int order,
683 unsigned long page_idx;
684 unsigned long combined_idx;
685 unsigned long uninitialized_var(buddy_idx);
687 unsigned int max_order = MAX_ORDER;
689 VM_BUG_ON(!zone_is_initialized(zone));
690 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
692 VM_BUG_ON(migratetype == -1);
693 if (is_migrate_isolate(migratetype)) {
695 * We restrict max order of merging to prevent merge
696 * between freepages on isolate pageblock and normal
697 * pageblock. Without this, pageblock isolation
698 * could cause incorrect freepage accounting.
700 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
702 __mod_zone_freepage_state(zone, 1 << order, migratetype);
705 page_idx = pfn & ((1 << max_order) - 1);
707 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
708 VM_BUG_ON_PAGE(bad_range(zone, page), page);
710 while (order < max_order - 1) {
711 buddy_idx = __find_buddy_index(page_idx, order);
712 buddy = page + (buddy_idx - page_idx);
713 if (!page_is_buddy(page, buddy, order))
716 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
717 * merge with it and move up one order.
719 if (page_is_guard(buddy)) {
720 clear_page_guard(zone, buddy, order, migratetype);
722 list_del(&buddy->lru);
723 zone->free_area[order].nr_free--;
724 rmv_page_order(buddy);
726 combined_idx = buddy_idx & page_idx;
727 page = page + (combined_idx - page_idx);
728 page_idx = combined_idx;
731 set_page_order(page, order);
734 * If this is not the largest possible page, check if the buddy
735 * of the next-highest order is free. If it is, it's possible
736 * that pages are being freed that will coalesce soon. In case,
737 * that is happening, add the free page to the tail of the list
738 * so it's less likely to be used soon and more likely to be merged
739 * as a higher order page
741 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
742 struct page *higher_page, *higher_buddy;
743 combined_idx = buddy_idx & page_idx;
744 higher_page = page + (combined_idx - page_idx);
745 buddy_idx = __find_buddy_index(combined_idx, order + 1);
746 higher_buddy = higher_page + (buddy_idx - combined_idx);
747 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
748 list_add_tail(&page->lru,
749 &zone->free_area[order].free_list[migratetype]);
754 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
756 zone->free_area[order].nr_free++;
759 static inline int free_pages_check(struct page *page)
761 const char *bad_reason = NULL;
762 unsigned long bad_flags = 0;
764 if (unlikely(atomic_read(&page->_mapcount) != -1))
765 bad_reason = "nonzero mapcount";
766 if (unlikely(page->mapping != NULL))
767 bad_reason = "non-NULL mapping";
768 if (unlikely(atomic_read(&page->_count) != 0))
769 bad_reason = "nonzero _count";
770 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
771 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
772 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
775 if (unlikely(page->mem_cgroup))
776 bad_reason = "page still charged to cgroup";
778 if (unlikely(bad_reason)) {
779 bad_page(page, bad_reason, bad_flags);
782 page_cpupid_reset_last(page);
783 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
784 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
789 * Frees a number of pages from the PCP lists
790 * Assumes all pages on list are in same zone, and of same order.
791 * count is the number of pages to free.
793 * If the zone was previously in an "all pages pinned" state then look to
794 * see if this freeing clears that state.
796 * And clear the zone's pages_scanned counter, to hold off the "all pages are
797 * pinned" detection logic.
799 static void free_pcppages_bulk(struct zone *zone, int count,
800 struct per_cpu_pages *pcp)
805 unsigned long nr_scanned;
807 spin_lock(&zone->lock);
808 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
810 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
814 struct list_head *list;
817 * Remove pages from lists in a round-robin fashion. A
818 * batch_free count is maintained that is incremented when an
819 * empty list is encountered. This is so more pages are freed
820 * off fuller lists instead of spinning excessively around empty
825 if (++migratetype == MIGRATE_PCPTYPES)
827 list = &pcp->lists[migratetype];
828 } while (list_empty(list));
830 /* This is the only non-empty list. Free them all. */
831 if (batch_free == MIGRATE_PCPTYPES)
832 batch_free = to_free;
835 int mt; /* migratetype of the to-be-freed page */
837 page = list_last_entry(list, struct page, lru);
838 /* must delete as __free_one_page list manipulates */
839 list_del(&page->lru);
841 mt = get_pcppage_migratetype(page);
842 /* MIGRATE_ISOLATE page should not go to pcplists */
843 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
844 /* Pageblock could have been isolated meanwhile */
845 if (unlikely(has_isolate_pageblock(zone)))
846 mt = get_pageblock_migratetype(page);
848 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
849 trace_mm_page_pcpu_drain(page, 0, mt);
850 } while (--to_free && --batch_free && !list_empty(list));
852 spin_unlock(&zone->lock);
855 static void free_one_page(struct zone *zone,
856 struct page *page, unsigned long pfn,
860 unsigned long nr_scanned;
861 spin_lock(&zone->lock);
862 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
864 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
866 if (unlikely(has_isolate_pageblock(zone) ||
867 is_migrate_isolate(migratetype))) {
868 migratetype = get_pfnblock_migratetype(page, pfn);
870 __free_one_page(page, pfn, zone, order, migratetype);
871 spin_unlock(&zone->lock);
874 static int free_tail_pages_check(struct page *head_page, struct page *page)
879 * We rely page->lru.next never has bit 0 set, unless the page
880 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
882 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
884 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
888 switch (page - head_page) {
890 /* the first tail page: ->mapping is compound_mapcount() */
891 if (unlikely(compound_mapcount(page))) {
892 bad_page(page, "nonzero compound_mapcount", 0);
898 * the second tail page: ->mapping is
899 * page_deferred_list().next -- ignore value.
903 if (page->mapping != TAIL_MAPPING) {
904 bad_page(page, "corrupted mapping in tail page", 0);
909 if (unlikely(!PageTail(page))) {
910 bad_page(page, "PageTail not set", 0);
913 if (unlikely(compound_head(page) != head_page)) {
914 bad_page(page, "compound_head not consistent", 0);
919 page->mapping = NULL;
920 clear_compound_head(page);
924 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
925 unsigned long zone, int nid)
927 set_page_links(page, zone, nid, pfn);
928 init_page_count(page);
929 page_mapcount_reset(page);
930 page_cpupid_reset_last(page);
932 INIT_LIST_HEAD(&page->lru);
933 #ifdef WANT_PAGE_VIRTUAL
934 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
935 if (!is_highmem_idx(zone))
936 set_page_address(page, __va(pfn << PAGE_SHIFT));
940 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
943 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
946 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
947 static void init_reserved_page(unsigned long pfn)
952 if (!early_page_uninitialised(pfn))
955 nid = early_pfn_to_nid(pfn);
956 pgdat = NODE_DATA(nid);
958 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
959 struct zone *zone = &pgdat->node_zones[zid];
961 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
964 __init_single_pfn(pfn, zid, nid);
967 static inline void init_reserved_page(unsigned long pfn)
970 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
973 * Initialised pages do not have PageReserved set. This function is
974 * called for each range allocated by the bootmem allocator and
975 * marks the pages PageReserved. The remaining valid pages are later
976 * sent to the buddy page allocator.
978 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
980 unsigned long start_pfn = PFN_DOWN(start);
981 unsigned long end_pfn = PFN_UP(end);
983 for (; start_pfn < end_pfn; start_pfn++) {
984 if (pfn_valid(start_pfn)) {
985 struct page *page = pfn_to_page(start_pfn);
987 init_reserved_page(start_pfn);
989 /* Avoid false-positive PageTail() */
990 INIT_LIST_HEAD(&page->lru);
992 SetPageReserved(page);
997 static bool free_pages_prepare(struct page *page, unsigned int order)
999 bool compound = PageCompound(page);
1002 VM_BUG_ON_PAGE(PageTail(page), page);
1003 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1005 trace_mm_page_free(page, order);
1006 kmemcheck_free_shadow(page, order);
1007 kasan_free_pages(page, order);
1010 page->mapping = NULL;
1011 bad += free_pages_check(page);
1012 for (i = 1; i < (1 << order); i++) {
1014 bad += free_tail_pages_check(page, page + i);
1015 bad += free_pages_check(page + i);
1020 reset_page_owner(page, order);
1022 if (!PageHighMem(page)) {
1023 debug_check_no_locks_freed(page_address(page),
1024 PAGE_SIZE << order);
1025 debug_check_no_obj_freed(page_address(page),
1026 PAGE_SIZE << order);
1028 arch_free_page(page, order);
1029 kernel_poison_pages(page, 1 << order, 0);
1030 kernel_map_pages(page, 1 << order, 0);
1035 static void __free_pages_ok(struct page *page, unsigned int order)
1037 unsigned long flags;
1039 unsigned long pfn = page_to_pfn(page);
1041 if (!free_pages_prepare(page, order))
1044 migratetype = get_pfnblock_migratetype(page, pfn);
1045 local_irq_save(flags);
1046 __count_vm_events(PGFREE, 1 << order);
1047 free_one_page(page_zone(page), page, pfn, order, migratetype);
1048 local_irq_restore(flags);
1051 static void __init __free_pages_boot_core(struct page *page,
1052 unsigned long pfn, unsigned int order)
1054 unsigned int nr_pages = 1 << order;
1055 struct page *p = page;
1059 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1061 __ClearPageReserved(p);
1062 set_page_count(p, 0);
1064 __ClearPageReserved(p);
1065 set_page_count(p, 0);
1067 page_zone(page)->managed_pages += nr_pages;
1068 set_page_refcounted(page);
1069 __free_pages(page, order);
1072 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1073 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1075 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1077 int __meminit early_pfn_to_nid(unsigned long pfn)
1079 static DEFINE_SPINLOCK(early_pfn_lock);
1082 spin_lock(&early_pfn_lock);
1083 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1086 spin_unlock(&early_pfn_lock);
1092 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1093 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1094 struct mminit_pfnnid_cache *state)
1098 nid = __early_pfn_to_nid(pfn, state);
1099 if (nid >= 0 && nid != node)
1104 /* Only safe to use early in boot when initialisation is single-threaded */
1105 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1107 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1112 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1116 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1117 struct mminit_pfnnid_cache *state)
1124 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1127 if (early_page_uninitialised(pfn))
1129 return __free_pages_boot_core(page, pfn, order);
1133 * Check that the whole (or subset of) a pageblock given by the interval of
1134 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1135 * with the migration of free compaction scanner. The scanners then need to
1136 * use only pfn_valid_within() check for arches that allow holes within
1139 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1141 * It's possible on some configurations to have a setup like node0 node1 node0
1142 * i.e. it's possible that all pages within a zones range of pages do not
1143 * belong to a single zone. We assume that a border between node0 and node1
1144 * can occur within a single pageblock, but not a node0 node1 node0
1145 * interleaving within a single pageblock. It is therefore sufficient to check
1146 * the first and last page of a pageblock and avoid checking each individual
1147 * page in a pageblock.
1149 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1150 unsigned long end_pfn, struct zone *zone)
1152 struct page *start_page;
1153 struct page *end_page;
1155 /* end_pfn is one past the range we are checking */
1158 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1161 start_page = pfn_to_page(start_pfn);
1163 if (page_zone(start_page) != zone)
1166 end_page = pfn_to_page(end_pfn);
1168 /* This gives a shorter code than deriving page_zone(end_page) */
1169 if (page_zone_id(start_page) != page_zone_id(end_page))
1175 void set_zone_contiguous(struct zone *zone)
1177 unsigned long block_start_pfn = zone->zone_start_pfn;
1178 unsigned long block_end_pfn;
1180 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1181 for (; block_start_pfn < zone_end_pfn(zone);
1182 block_start_pfn = block_end_pfn,
1183 block_end_pfn += pageblock_nr_pages) {
1185 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1187 if (!__pageblock_pfn_to_page(block_start_pfn,
1188 block_end_pfn, zone))
1192 /* We confirm that there is no hole */
1193 zone->contiguous = true;
1196 void clear_zone_contiguous(struct zone *zone)
1198 zone->contiguous = false;
1201 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1202 static void __init deferred_free_range(struct page *page,
1203 unsigned long pfn, int nr_pages)
1210 /* Free a large naturally-aligned chunk if possible */
1211 if (nr_pages == MAX_ORDER_NR_PAGES &&
1212 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1213 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1214 __free_pages_boot_core(page, pfn, MAX_ORDER-1);
1218 for (i = 0; i < nr_pages; i++, page++, pfn++)
1219 __free_pages_boot_core(page, pfn, 0);
1222 /* Completion tracking for deferred_init_memmap() threads */
1223 static atomic_t pgdat_init_n_undone __initdata;
1224 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1226 static inline void __init pgdat_init_report_one_done(void)
1228 if (atomic_dec_and_test(&pgdat_init_n_undone))
1229 complete(&pgdat_init_all_done_comp);
1232 /* Initialise remaining memory on a node */
1233 static int __init deferred_init_memmap(void *data)
1235 pg_data_t *pgdat = data;
1236 int nid = pgdat->node_id;
1237 struct mminit_pfnnid_cache nid_init_state = { };
1238 unsigned long start = jiffies;
1239 unsigned long nr_pages = 0;
1240 unsigned long walk_start, walk_end;
1243 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1244 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1246 if (first_init_pfn == ULONG_MAX) {
1247 pgdat_init_report_one_done();
1251 /* Bind memory initialisation thread to a local node if possible */
1252 if (!cpumask_empty(cpumask))
1253 set_cpus_allowed_ptr(current, cpumask);
1255 /* Sanity check boundaries */
1256 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1257 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1258 pgdat->first_deferred_pfn = ULONG_MAX;
1260 /* Only the highest zone is deferred so find it */
1261 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1262 zone = pgdat->node_zones + zid;
1263 if (first_init_pfn < zone_end_pfn(zone))
1267 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1268 unsigned long pfn, end_pfn;
1269 struct page *page = NULL;
1270 struct page *free_base_page = NULL;
1271 unsigned long free_base_pfn = 0;
1274 end_pfn = min(walk_end, zone_end_pfn(zone));
1275 pfn = first_init_pfn;
1276 if (pfn < walk_start)
1278 if (pfn < zone->zone_start_pfn)
1279 pfn = zone->zone_start_pfn;
1281 for (; pfn < end_pfn; pfn++) {
1282 if (!pfn_valid_within(pfn))
1286 * Ensure pfn_valid is checked every
1287 * MAX_ORDER_NR_PAGES for memory holes
1289 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1290 if (!pfn_valid(pfn)) {
1296 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1301 /* Minimise pfn page lookups and scheduler checks */
1302 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1305 nr_pages += nr_to_free;
1306 deferred_free_range(free_base_page,
1307 free_base_pfn, nr_to_free);
1308 free_base_page = NULL;
1309 free_base_pfn = nr_to_free = 0;
1311 page = pfn_to_page(pfn);
1316 VM_BUG_ON(page_zone(page) != zone);
1320 __init_single_page(page, pfn, zid, nid);
1321 if (!free_base_page) {
1322 free_base_page = page;
1323 free_base_pfn = pfn;
1328 /* Where possible, batch up pages for a single free */
1331 /* Free the current block of pages to allocator */
1332 nr_pages += nr_to_free;
1333 deferred_free_range(free_base_page, free_base_pfn,
1335 free_base_page = NULL;
1336 free_base_pfn = nr_to_free = 0;
1339 first_init_pfn = max(end_pfn, first_init_pfn);
1342 /* Sanity check that the next zone really is unpopulated */
1343 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1345 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1346 jiffies_to_msecs(jiffies - start));
1348 pgdat_init_report_one_done();
1351 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1353 void __init page_alloc_init_late(void)
1357 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1360 /* There will be num_node_state(N_MEMORY) threads */
1361 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1362 for_each_node_state(nid, N_MEMORY) {
1363 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1366 /* Block until all are initialised */
1367 wait_for_completion(&pgdat_init_all_done_comp);
1369 /* Reinit limits that are based on free pages after the kernel is up */
1370 files_maxfiles_init();
1373 for_each_populated_zone(zone)
1374 set_zone_contiguous(zone);
1378 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1379 void __init init_cma_reserved_pageblock(struct page *page)
1381 unsigned i = pageblock_nr_pages;
1382 struct page *p = page;
1385 __ClearPageReserved(p);
1386 set_page_count(p, 0);
1389 set_pageblock_migratetype(page, MIGRATE_CMA);
1391 if (pageblock_order >= MAX_ORDER) {
1392 i = pageblock_nr_pages;
1395 set_page_refcounted(p);
1396 __free_pages(p, MAX_ORDER - 1);
1397 p += MAX_ORDER_NR_PAGES;
1398 } while (i -= MAX_ORDER_NR_PAGES);
1400 set_page_refcounted(page);
1401 __free_pages(page, pageblock_order);
1404 adjust_managed_page_count(page, pageblock_nr_pages);
1409 * The order of subdivision here is critical for the IO subsystem.
1410 * Please do not alter this order without good reasons and regression
1411 * testing. Specifically, as large blocks of memory are subdivided,
1412 * the order in which smaller blocks are delivered depends on the order
1413 * they're subdivided in this function. This is the primary factor
1414 * influencing the order in which pages are delivered to the IO
1415 * subsystem according to empirical testing, and this is also justified
1416 * by considering the behavior of a buddy system containing a single
1417 * large block of memory acted on by a series of small allocations.
1418 * This behavior is a critical factor in sglist merging's success.
1422 static inline void expand(struct zone *zone, struct page *page,
1423 int low, int high, struct free_area *area,
1426 unsigned long size = 1 << high;
1428 while (high > low) {
1432 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1434 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1435 debug_guardpage_enabled() &&
1436 high < debug_guardpage_minorder()) {
1438 * Mark as guard pages (or page), that will allow to
1439 * merge back to allocator when buddy will be freed.
1440 * Corresponding page table entries will not be touched,
1441 * pages will stay not present in virtual address space
1443 set_page_guard(zone, &page[size], high, migratetype);
1446 list_add(&page[size].lru, &area->free_list[migratetype]);
1448 set_page_order(&page[size], high);
1453 * This page is about to be returned from the page allocator
1455 static inline int check_new_page(struct page *page)
1457 const char *bad_reason = NULL;
1458 unsigned long bad_flags = 0;
1460 if (unlikely(atomic_read(&page->_mapcount) != -1))
1461 bad_reason = "nonzero mapcount";
1462 if (unlikely(page->mapping != NULL))
1463 bad_reason = "non-NULL mapping";
1464 if (unlikely(atomic_read(&page->_count) != 0))
1465 bad_reason = "nonzero _count";
1466 if (unlikely(page->flags & __PG_HWPOISON)) {
1467 bad_reason = "HWPoisoned (hardware-corrupted)";
1468 bad_flags = __PG_HWPOISON;
1470 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1471 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1472 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1475 if (unlikely(page->mem_cgroup))
1476 bad_reason = "page still charged to cgroup";
1478 if (unlikely(bad_reason)) {
1479 bad_page(page, bad_reason, bad_flags);
1485 static inline bool free_pages_prezeroed(bool poisoned)
1487 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1488 page_poisoning_enabled() && poisoned;
1491 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1495 bool poisoned = true;
1497 for (i = 0; i < (1 << order); i++) {
1498 struct page *p = page + i;
1499 if (unlikely(check_new_page(p)))
1502 poisoned &= page_is_poisoned(p);
1505 set_page_private(page, 0);
1506 set_page_refcounted(page);
1508 arch_alloc_page(page, order);
1509 kernel_map_pages(page, 1 << order, 1);
1510 kernel_poison_pages(page, 1 << order, 1);
1511 kasan_alloc_pages(page, order);
1513 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1514 for (i = 0; i < (1 << order); i++)
1515 clear_highpage(page + i);
1517 if (order && (gfp_flags & __GFP_COMP))
1518 prep_compound_page(page, order);
1520 set_page_owner(page, order, gfp_flags);
1523 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1524 * allocate the page. The expectation is that the caller is taking
1525 * steps that will free more memory. The caller should avoid the page
1526 * being used for !PFMEMALLOC purposes.
1528 if (alloc_flags & ALLOC_NO_WATERMARKS)
1529 set_page_pfmemalloc(page);
1531 clear_page_pfmemalloc(page);
1537 * Go through the free lists for the given migratetype and remove
1538 * the smallest available page from the freelists
1541 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1544 unsigned int current_order;
1545 struct free_area *area;
1548 /* Find a page of the appropriate size in the preferred list */
1549 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1550 area = &(zone->free_area[current_order]);
1551 page = list_first_entry_or_null(&area->free_list[migratetype],
1555 list_del(&page->lru);
1556 rmv_page_order(page);
1558 expand(zone, page, order, current_order, area, migratetype);
1559 set_pcppage_migratetype(page, migratetype);
1568 * This array describes the order lists are fallen back to when
1569 * the free lists for the desirable migrate type are depleted
1571 static int fallbacks[MIGRATE_TYPES][4] = {
1572 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1573 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1574 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1576 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1578 #ifdef CONFIG_MEMORY_ISOLATION
1579 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1584 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1587 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1590 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1591 unsigned int order) { return NULL; }
1595 * Move the free pages in a range to the free lists of the requested type.
1596 * Note that start_page and end_pages are not aligned on a pageblock
1597 * boundary. If alignment is required, use move_freepages_block()
1599 int move_freepages(struct zone *zone,
1600 struct page *start_page, struct page *end_page,
1605 int pages_moved = 0;
1607 #ifndef CONFIG_HOLES_IN_ZONE
1609 * page_zone is not safe to call in this context when
1610 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1611 * anyway as we check zone boundaries in move_freepages_block().
1612 * Remove at a later date when no bug reports exist related to
1613 * grouping pages by mobility
1615 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1618 for (page = start_page; page <= end_page;) {
1619 /* Make sure we are not inadvertently changing nodes */
1620 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1622 if (!pfn_valid_within(page_to_pfn(page))) {
1627 if (!PageBuddy(page)) {
1632 order = page_order(page);
1633 list_move(&page->lru,
1634 &zone->free_area[order].free_list[migratetype]);
1636 pages_moved += 1 << order;
1642 int move_freepages_block(struct zone *zone, struct page *page,
1645 unsigned long start_pfn, end_pfn;
1646 struct page *start_page, *end_page;
1648 start_pfn = page_to_pfn(page);
1649 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1650 start_page = pfn_to_page(start_pfn);
1651 end_page = start_page + pageblock_nr_pages - 1;
1652 end_pfn = start_pfn + pageblock_nr_pages - 1;
1654 /* Do not cross zone boundaries */
1655 if (!zone_spans_pfn(zone, start_pfn))
1657 if (!zone_spans_pfn(zone, end_pfn))
1660 return move_freepages(zone, start_page, end_page, migratetype);
1663 static void change_pageblock_range(struct page *pageblock_page,
1664 int start_order, int migratetype)
1666 int nr_pageblocks = 1 << (start_order - pageblock_order);
1668 while (nr_pageblocks--) {
1669 set_pageblock_migratetype(pageblock_page, migratetype);
1670 pageblock_page += pageblock_nr_pages;
1675 * When we are falling back to another migratetype during allocation, try to
1676 * steal extra free pages from the same pageblocks to satisfy further
1677 * allocations, instead of polluting multiple pageblocks.
1679 * If we are stealing a relatively large buddy page, it is likely there will
1680 * be more free pages in the pageblock, so try to steal them all. For
1681 * reclaimable and unmovable allocations, we steal regardless of page size,
1682 * as fragmentation caused by those allocations polluting movable pageblocks
1683 * is worse than movable allocations stealing from unmovable and reclaimable
1686 static bool can_steal_fallback(unsigned int order, int start_mt)
1689 * Leaving this order check is intended, although there is
1690 * relaxed order check in next check. The reason is that
1691 * we can actually steal whole pageblock if this condition met,
1692 * but, below check doesn't guarantee it and that is just heuristic
1693 * so could be changed anytime.
1695 if (order >= pageblock_order)
1698 if (order >= pageblock_order / 2 ||
1699 start_mt == MIGRATE_RECLAIMABLE ||
1700 start_mt == MIGRATE_UNMOVABLE ||
1701 page_group_by_mobility_disabled)
1708 * This function implements actual steal behaviour. If order is large enough,
1709 * we can steal whole pageblock. If not, we first move freepages in this
1710 * pageblock and check whether half of pages are moved or not. If half of
1711 * pages are moved, we can change migratetype of pageblock and permanently
1712 * use it's pages as requested migratetype in the future.
1714 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1717 unsigned int current_order = page_order(page);
1720 /* Take ownership for orders >= pageblock_order */
1721 if (current_order >= pageblock_order) {
1722 change_pageblock_range(page, current_order, start_type);
1726 pages = move_freepages_block(zone, page, start_type);
1728 /* Claim the whole block if over half of it is free */
1729 if (pages >= (1 << (pageblock_order-1)) ||
1730 page_group_by_mobility_disabled)
1731 set_pageblock_migratetype(page, start_type);
1735 * Check whether there is a suitable fallback freepage with requested order.
1736 * If only_stealable is true, this function returns fallback_mt only if
1737 * we can steal other freepages all together. This would help to reduce
1738 * fragmentation due to mixed migratetype pages in one pageblock.
1740 int find_suitable_fallback(struct free_area *area, unsigned int order,
1741 int migratetype, bool only_stealable, bool *can_steal)
1746 if (area->nr_free == 0)
1751 fallback_mt = fallbacks[migratetype][i];
1752 if (fallback_mt == MIGRATE_TYPES)
1755 if (list_empty(&area->free_list[fallback_mt]))
1758 if (can_steal_fallback(order, migratetype))
1761 if (!only_stealable)
1772 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1773 * there are no empty page blocks that contain a page with a suitable order
1775 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
1776 unsigned int alloc_order)
1779 unsigned long max_managed, flags;
1782 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1783 * Check is race-prone but harmless.
1785 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
1786 if (zone->nr_reserved_highatomic >= max_managed)
1789 spin_lock_irqsave(&zone->lock, flags);
1791 /* Recheck the nr_reserved_highatomic limit under the lock */
1792 if (zone->nr_reserved_highatomic >= max_managed)
1796 mt = get_pageblock_migratetype(page);
1797 if (mt != MIGRATE_HIGHATOMIC &&
1798 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
1799 zone->nr_reserved_highatomic += pageblock_nr_pages;
1800 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
1801 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
1805 spin_unlock_irqrestore(&zone->lock, flags);
1809 * Used when an allocation is about to fail under memory pressure. This
1810 * potentially hurts the reliability of high-order allocations when under
1811 * intense memory pressure but failed atomic allocations should be easier
1812 * to recover from than an OOM.
1814 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
1816 struct zonelist *zonelist = ac->zonelist;
1817 unsigned long flags;
1823 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
1825 /* Preserve at least one pageblock */
1826 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
1829 spin_lock_irqsave(&zone->lock, flags);
1830 for (order = 0; order < MAX_ORDER; order++) {
1831 struct free_area *area = &(zone->free_area[order]);
1833 page = list_first_entry_or_null(
1834 &area->free_list[MIGRATE_HIGHATOMIC],
1840 * It should never happen but changes to locking could
1841 * inadvertently allow a per-cpu drain to add pages
1842 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1843 * and watch for underflows.
1845 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
1846 zone->nr_reserved_highatomic);
1849 * Convert to ac->migratetype and avoid the normal
1850 * pageblock stealing heuristics. Minimally, the caller
1851 * is doing the work and needs the pages. More
1852 * importantly, if the block was always converted to
1853 * MIGRATE_UNMOVABLE or another type then the number
1854 * of pageblocks that cannot be completely freed
1857 set_pageblock_migratetype(page, ac->migratetype);
1858 move_freepages_block(zone, page, ac->migratetype);
1859 spin_unlock_irqrestore(&zone->lock, flags);
1862 spin_unlock_irqrestore(&zone->lock, flags);
1866 /* Remove an element from the buddy allocator from the fallback list */
1867 static inline struct page *
1868 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1870 struct free_area *area;
1871 unsigned int current_order;
1876 /* Find the largest possible block of pages in the other list */
1877 for (current_order = MAX_ORDER-1;
1878 current_order >= order && current_order <= MAX_ORDER-1;
1880 area = &(zone->free_area[current_order]);
1881 fallback_mt = find_suitable_fallback(area, current_order,
1882 start_migratetype, false, &can_steal);
1883 if (fallback_mt == -1)
1886 page = list_first_entry(&area->free_list[fallback_mt],
1889 steal_suitable_fallback(zone, page, start_migratetype);
1891 /* Remove the page from the freelists */
1893 list_del(&page->lru);
1894 rmv_page_order(page);
1896 expand(zone, page, order, current_order, area,
1899 * The pcppage_migratetype may differ from pageblock's
1900 * migratetype depending on the decisions in
1901 * find_suitable_fallback(). This is OK as long as it does not
1902 * differ for MIGRATE_CMA pageblocks. Those can be used as
1903 * fallback only via special __rmqueue_cma_fallback() function
1905 set_pcppage_migratetype(page, start_migratetype);
1907 trace_mm_page_alloc_extfrag(page, order, current_order,
1908 start_migratetype, fallback_mt);
1917 * Do the hard work of removing an element from the buddy allocator.
1918 * Call me with the zone->lock already held.
1920 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1925 page = __rmqueue_smallest(zone, order, migratetype);
1926 if (unlikely(!page)) {
1927 if (migratetype == MIGRATE_MOVABLE)
1928 page = __rmqueue_cma_fallback(zone, order);
1931 page = __rmqueue_fallback(zone, order, migratetype);
1934 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1939 * Obtain a specified number of elements from the buddy allocator, all under
1940 * a single hold of the lock, for efficiency. Add them to the supplied list.
1941 * Returns the number of new pages which were placed at *list.
1943 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1944 unsigned long count, struct list_head *list,
1945 int migratetype, bool cold)
1949 spin_lock(&zone->lock);
1950 for (i = 0; i < count; ++i) {
1951 struct page *page = __rmqueue(zone, order, migratetype);
1952 if (unlikely(page == NULL))
1956 * Split buddy pages returned by expand() are received here
1957 * in physical page order. The page is added to the callers and
1958 * list and the list head then moves forward. From the callers
1959 * perspective, the linked list is ordered by page number in
1960 * some conditions. This is useful for IO devices that can
1961 * merge IO requests if the physical pages are ordered
1965 list_add(&page->lru, list);
1967 list_add_tail(&page->lru, list);
1969 if (is_migrate_cma(get_pcppage_migratetype(page)))
1970 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1973 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1974 spin_unlock(&zone->lock);
1980 * Called from the vmstat counter updater to drain pagesets of this
1981 * currently executing processor on remote nodes after they have
1984 * Note that this function must be called with the thread pinned to
1985 * a single processor.
1987 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1989 unsigned long flags;
1990 int to_drain, batch;
1992 local_irq_save(flags);
1993 batch = READ_ONCE(pcp->batch);
1994 to_drain = min(pcp->count, batch);
1996 free_pcppages_bulk(zone, to_drain, pcp);
1997 pcp->count -= to_drain;
1999 local_irq_restore(flags);
2004 * Drain pcplists of the indicated processor and zone.
2006 * The processor must either be the current processor and the
2007 * thread pinned to the current processor or a processor that
2010 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2012 unsigned long flags;
2013 struct per_cpu_pageset *pset;
2014 struct per_cpu_pages *pcp;
2016 local_irq_save(flags);
2017 pset = per_cpu_ptr(zone->pageset, cpu);
2021 free_pcppages_bulk(zone, pcp->count, pcp);
2024 local_irq_restore(flags);
2028 * Drain pcplists of all zones on the indicated processor.
2030 * The processor must either be the current processor and the
2031 * thread pinned to the current processor or a processor that
2034 static void drain_pages(unsigned int cpu)
2038 for_each_populated_zone(zone) {
2039 drain_pages_zone(cpu, zone);
2044 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2046 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2047 * the single zone's pages.
2049 void drain_local_pages(struct zone *zone)
2051 int cpu = smp_processor_id();
2054 drain_pages_zone(cpu, zone);
2060 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2062 * When zone parameter is non-NULL, spill just the single zone's pages.
2064 * Note that this code is protected against sending an IPI to an offline
2065 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2066 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2067 * nothing keeps CPUs from showing up after we populated the cpumask and
2068 * before the call to on_each_cpu_mask().
2070 void drain_all_pages(struct zone *zone)
2075 * Allocate in the BSS so we wont require allocation in
2076 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2078 static cpumask_t cpus_with_pcps;
2081 * We don't care about racing with CPU hotplug event
2082 * as offline notification will cause the notified
2083 * cpu to drain that CPU pcps and on_each_cpu_mask
2084 * disables preemption as part of its processing
2086 for_each_online_cpu(cpu) {
2087 struct per_cpu_pageset *pcp;
2089 bool has_pcps = false;
2092 pcp = per_cpu_ptr(zone->pageset, cpu);
2096 for_each_populated_zone(z) {
2097 pcp = per_cpu_ptr(z->pageset, cpu);
2098 if (pcp->pcp.count) {
2106 cpumask_set_cpu(cpu, &cpus_with_pcps);
2108 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2110 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2114 #ifdef CONFIG_HIBERNATION
2116 void mark_free_pages(struct zone *zone)
2118 unsigned long pfn, max_zone_pfn;
2119 unsigned long flags;
2120 unsigned int order, t;
2123 if (zone_is_empty(zone))
2126 spin_lock_irqsave(&zone->lock, flags);
2128 max_zone_pfn = zone_end_pfn(zone);
2129 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2130 if (pfn_valid(pfn)) {
2131 page = pfn_to_page(pfn);
2132 if (!swsusp_page_is_forbidden(page))
2133 swsusp_unset_page_free(page);
2136 for_each_migratetype_order(order, t) {
2137 list_for_each_entry(page,
2138 &zone->free_area[order].free_list[t], lru) {
2141 pfn = page_to_pfn(page);
2142 for (i = 0; i < (1UL << order); i++)
2143 swsusp_set_page_free(pfn_to_page(pfn + i));
2146 spin_unlock_irqrestore(&zone->lock, flags);
2148 #endif /* CONFIG_PM */
2151 * Free a 0-order page
2152 * cold == true ? free a cold page : free a hot page
2154 void free_hot_cold_page(struct page *page, bool cold)
2156 struct zone *zone = page_zone(page);
2157 struct per_cpu_pages *pcp;
2158 unsigned long flags;
2159 unsigned long pfn = page_to_pfn(page);
2162 if (!free_pages_prepare(page, 0))
2165 migratetype = get_pfnblock_migratetype(page, pfn);
2166 set_pcppage_migratetype(page, migratetype);
2167 local_irq_save(flags);
2168 __count_vm_event(PGFREE);
2171 * We only track unmovable, reclaimable and movable on pcp lists.
2172 * Free ISOLATE pages back to the allocator because they are being
2173 * offlined but treat RESERVE as movable pages so we can get those
2174 * areas back if necessary. Otherwise, we may have to free
2175 * excessively into the page allocator
2177 if (migratetype >= MIGRATE_PCPTYPES) {
2178 if (unlikely(is_migrate_isolate(migratetype))) {
2179 free_one_page(zone, page, pfn, 0, migratetype);
2182 migratetype = MIGRATE_MOVABLE;
2185 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2187 list_add(&page->lru, &pcp->lists[migratetype]);
2189 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2191 if (pcp->count >= pcp->high) {
2192 unsigned long batch = READ_ONCE(pcp->batch);
2193 free_pcppages_bulk(zone, batch, pcp);
2194 pcp->count -= batch;
2198 local_irq_restore(flags);
2202 * Free a list of 0-order pages
2204 void free_hot_cold_page_list(struct list_head *list, bool cold)
2206 struct page *page, *next;
2208 list_for_each_entry_safe(page, next, list, lru) {
2209 trace_mm_page_free_batched(page, cold);
2210 free_hot_cold_page(page, cold);
2215 * split_page takes a non-compound higher-order page, and splits it into
2216 * n (1<<order) sub-pages: page[0..n]
2217 * Each sub-page must be freed individually.
2219 * Note: this is probably too low level an operation for use in drivers.
2220 * Please consult with lkml before using this in your driver.
2222 void split_page(struct page *page, unsigned int order)
2227 VM_BUG_ON_PAGE(PageCompound(page), page);
2228 VM_BUG_ON_PAGE(!page_count(page), page);
2230 #ifdef CONFIG_KMEMCHECK
2232 * Split shadow pages too, because free(page[0]) would
2233 * otherwise free the whole shadow.
2235 if (kmemcheck_page_is_tracked(page))
2236 split_page(virt_to_page(page[0].shadow), order);
2239 gfp_mask = get_page_owner_gfp(page);
2240 set_page_owner(page, 0, gfp_mask);
2241 for (i = 1; i < (1 << order); i++) {
2242 set_page_refcounted(page + i);
2243 set_page_owner(page + i, 0, gfp_mask);
2246 EXPORT_SYMBOL_GPL(split_page);
2248 int __isolate_free_page(struct page *page, unsigned int order)
2250 unsigned long watermark;
2254 BUG_ON(!PageBuddy(page));
2256 zone = page_zone(page);
2257 mt = get_pageblock_migratetype(page);
2259 if (!is_migrate_isolate(mt)) {
2260 /* Obey watermarks as if the page was being allocated */
2261 watermark = low_wmark_pages(zone) + (1 << order);
2262 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2265 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2268 /* Remove page from free list */
2269 list_del(&page->lru);
2270 zone->free_area[order].nr_free--;
2271 rmv_page_order(page);
2273 set_page_owner(page, order, __GFP_MOVABLE);
2275 /* Set the pageblock if the isolated page is at least a pageblock */
2276 if (order >= pageblock_order - 1) {
2277 struct page *endpage = page + (1 << order) - 1;
2278 for (; page < endpage; page += pageblock_nr_pages) {
2279 int mt = get_pageblock_migratetype(page);
2280 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2281 set_pageblock_migratetype(page,
2287 return 1UL << order;
2291 * Similar to split_page except the page is already free. As this is only
2292 * being used for migration, the migratetype of the block also changes.
2293 * As this is called with interrupts disabled, the caller is responsible
2294 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2297 * Note: this is probably too low level an operation for use in drivers.
2298 * Please consult with lkml before using this in your driver.
2300 int split_free_page(struct page *page)
2305 order = page_order(page);
2307 nr_pages = __isolate_free_page(page, order);
2311 /* Split into individual pages */
2312 set_page_refcounted(page);
2313 split_page(page, order);
2318 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2321 struct page *buffered_rmqueue(struct zone *preferred_zone,
2322 struct zone *zone, unsigned int order,
2323 gfp_t gfp_flags, int alloc_flags, int migratetype)
2325 unsigned long flags;
2327 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2329 if (likely(order == 0)) {
2330 struct per_cpu_pages *pcp;
2331 struct list_head *list;
2333 local_irq_save(flags);
2334 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2335 list = &pcp->lists[migratetype];
2336 if (list_empty(list)) {
2337 pcp->count += rmqueue_bulk(zone, 0,
2340 if (unlikely(list_empty(list)))
2345 page = list_last_entry(list, struct page, lru);
2347 page = list_first_entry(list, struct page, lru);
2349 list_del(&page->lru);
2352 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
2354 * __GFP_NOFAIL is not to be used in new code.
2356 * All __GFP_NOFAIL callers should be fixed so that they
2357 * properly detect and handle allocation failures.
2359 * We most definitely don't want callers attempting to
2360 * allocate greater than order-1 page units with
2363 WARN_ON_ONCE(order > 1);
2365 spin_lock_irqsave(&zone->lock, flags);
2368 if (alloc_flags & ALLOC_HARDER) {
2369 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2371 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2374 page = __rmqueue(zone, order, migratetype);
2375 spin_unlock(&zone->lock);
2378 __mod_zone_freepage_state(zone, -(1 << order),
2379 get_pcppage_migratetype(page));
2382 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2383 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2384 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2385 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2387 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2388 zone_statistics(preferred_zone, zone, gfp_flags);
2389 local_irq_restore(flags);
2391 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2395 local_irq_restore(flags);
2399 #ifdef CONFIG_FAIL_PAGE_ALLOC
2402 struct fault_attr attr;
2404 bool ignore_gfp_highmem;
2405 bool ignore_gfp_reclaim;
2407 } fail_page_alloc = {
2408 .attr = FAULT_ATTR_INITIALIZER,
2409 .ignore_gfp_reclaim = true,
2410 .ignore_gfp_highmem = true,
2414 static int __init setup_fail_page_alloc(char *str)
2416 return setup_fault_attr(&fail_page_alloc.attr, str);
2418 __setup("fail_page_alloc=", setup_fail_page_alloc);
2420 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2422 if (order < fail_page_alloc.min_order)
2424 if (gfp_mask & __GFP_NOFAIL)
2426 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2428 if (fail_page_alloc.ignore_gfp_reclaim &&
2429 (gfp_mask & __GFP_DIRECT_RECLAIM))
2432 return should_fail(&fail_page_alloc.attr, 1 << order);
2435 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2437 static int __init fail_page_alloc_debugfs(void)
2439 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2442 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2443 &fail_page_alloc.attr);
2445 return PTR_ERR(dir);
2447 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2448 &fail_page_alloc.ignore_gfp_reclaim))
2450 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2451 &fail_page_alloc.ignore_gfp_highmem))
2453 if (!debugfs_create_u32("min-order", mode, dir,
2454 &fail_page_alloc.min_order))
2459 debugfs_remove_recursive(dir);
2464 late_initcall(fail_page_alloc_debugfs);
2466 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2468 #else /* CONFIG_FAIL_PAGE_ALLOC */
2470 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2475 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2478 * Return true if free base pages are above 'mark'. For high-order checks it
2479 * will return true of the order-0 watermark is reached and there is at least
2480 * one free page of a suitable size. Checking now avoids taking the zone lock
2481 * to check in the allocation paths if no pages are free.
2483 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2484 unsigned long mark, int classzone_idx, int alloc_flags,
2489 const int alloc_harder = (alloc_flags & ALLOC_HARDER);
2491 /* free_pages may go negative - that's OK */
2492 free_pages -= (1 << order) - 1;
2494 if (alloc_flags & ALLOC_HIGH)
2498 * If the caller does not have rights to ALLOC_HARDER then subtract
2499 * the high-atomic reserves. This will over-estimate the size of the
2500 * atomic reserve but it avoids a search.
2502 if (likely(!alloc_harder))
2503 free_pages -= z->nr_reserved_highatomic;
2508 /* If allocation can't use CMA areas don't use free CMA pages */
2509 if (!(alloc_flags & ALLOC_CMA))
2510 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2514 * Check watermarks for an order-0 allocation request. If these
2515 * are not met, then a high-order request also cannot go ahead
2516 * even if a suitable page happened to be free.
2518 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2521 /* If this is an order-0 request then the watermark is fine */
2525 /* For a high-order request, check at least one suitable page is free */
2526 for (o = order; o < MAX_ORDER; o++) {
2527 struct free_area *area = &z->free_area[o];
2536 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2537 if (!list_empty(&area->free_list[mt]))
2542 if ((alloc_flags & ALLOC_CMA) &&
2543 !list_empty(&area->free_list[MIGRATE_CMA])) {
2551 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2552 int classzone_idx, int alloc_flags)
2554 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2555 zone_page_state(z, NR_FREE_PAGES));
2558 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2559 unsigned long mark, int classzone_idx)
2561 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2563 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2564 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2566 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2571 static bool zone_local(struct zone *local_zone, struct zone *zone)
2573 return local_zone->node == zone->node;
2576 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2578 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2581 #else /* CONFIG_NUMA */
2582 static bool zone_local(struct zone *local_zone, struct zone *zone)
2587 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2591 #endif /* CONFIG_NUMA */
2593 static void reset_alloc_batches(struct zone *preferred_zone)
2595 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2598 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2599 high_wmark_pages(zone) - low_wmark_pages(zone) -
2600 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2601 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2602 } while (zone++ != preferred_zone);
2606 * get_page_from_freelist goes through the zonelist trying to allocate
2609 static struct page *
2610 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2611 const struct alloc_context *ac)
2613 struct zonelist *zonelist = ac->zonelist;
2615 struct page *page = NULL;
2617 int nr_fair_skipped = 0;
2618 bool zonelist_rescan;
2621 zonelist_rescan = false;
2624 * Scan zonelist, looking for a zone with enough free.
2625 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2627 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2631 if (cpusets_enabled() &&
2632 (alloc_flags & ALLOC_CPUSET) &&
2633 !cpuset_zone_allowed(zone, gfp_mask))
2636 * Distribute pages in proportion to the individual
2637 * zone size to ensure fair page aging. The zone a
2638 * page was allocated in should have no effect on the
2639 * time the page has in memory before being reclaimed.
2641 if (alloc_flags & ALLOC_FAIR) {
2642 if (!zone_local(ac->preferred_zone, zone))
2644 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2650 * When allocating a page cache page for writing, we
2651 * want to get it from a zone that is within its dirty
2652 * limit, such that no single zone holds more than its
2653 * proportional share of globally allowed dirty pages.
2654 * The dirty limits take into account the zone's
2655 * lowmem reserves and high watermark so that kswapd
2656 * should be able to balance it without having to
2657 * write pages from its LRU list.
2659 * This may look like it could increase pressure on
2660 * lower zones by failing allocations in higher zones
2661 * before they are full. But the pages that do spill
2662 * over are limited as the lower zones are protected
2663 * by this very same mechanism. It should not become
2664 * a practical burden to them.
2666 * XXX: For now, allow allocations to potentially
2667 * exceed the per-zone dirty limit in the slowpath
2668 * (spread_dirty_pages unset) before going into reclaim,
2669 * which is important when on a NUMA setup the allowed
2670 * zones are together not big enough to reach the
2671 * global limit. The proper fix for these situations
2672 * will require awareness of zones in the
2673 * dirty-throttling and the flusher threads.
2675 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2678 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2679 if (!zone_watermark_ok(zone, order, mark,
2680 ac->classzone_idx, alloc_flags)) {
2683 /* Checked here to keep the fast path fast */
2684 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2685 if (alloc_flags & ALLOC_NO_WATERMARKS)
2688 if (zone_reclaim_mode == 0 ||
2689 !zone_allows_reclaim(ac->preferred_zone, zone))
2692 ret = zone_reclaim(zone, gfp_mask, order);
2694 case ZONE_RECLAIM_NOSCAN:
2697 case ZONE_RECLAIM_FULL:
2698 /* scanned but unreclaimable */
2701 /* did we reclaim enough */
2702 if (zone_watermark_ok(zone, order, mark,
2703 ac->classzone_idx, alloc_flags))
2711 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2712 gfp_mask, alloc_flags, ac->migratetype);
2714 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2718 * If this is a high-order atomic allocation then check
2719 * if the pageblock should be reserved for the future
2721 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2722 reserve_highatomic_pageblock(page, zone, order);
2729 * The first pass makes sure allocations are spread fairly within the
2730 * local node. However, the local node might have free pages left
2731 * after the fairness batches are exhausted, and remote zones haven't
2732 * even been considered yet. Try once more without fairness, and
2733 * include remote zones now, before entering the slowpath and waking
2734 * kswapd: prefer spilling to a remote zone over swapping locally.
2736 if (alloc_flags & ALLOC_FAIR) {
2737 alloc_flags &= ~ALLOC_FAIR;
2738 if (nr_fair_skipped) {
2739 zonelist_rescan = true;
2740 reset_alloc_batches(ac->preferred_zone);
2742 if (nr_online_nodes > 1)
2743 zonelist_rescan = true;
2746 if (zonelist_rescan)
2753 * Large machines with many possible nodes should not always dump per-node
2754 * meminfo in irq context.
2756 static inline bool should_suppress_show_mem(void)
2761 ret = in_interrupt();
2766 static DEFINE_RATELIMIT_STATE(nopage_rs,
2767 DEFAULT_RATELIMIT_INTERVAL,
2768 DEFAULT_RATELIMIT_BURST);
2770 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
2772 unsigned int filter = SHOW_MEM_FILTER_NODES;
2774 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2775 debug_guardpage_minorder() > 0)
2779 * This documents exceptions given to allocations in certain
2780 * contexts that are allowed to allocate outside current's set
2783 if (!(gfp_mask & __GFP_NOMEMALLOC))
2784 if (test_thread_flag(TIF_MEMDIE) ||
2785 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2786 filter &= ~SHOW_MEM_FILTER_NODES;
2787 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
2788 filter &= ~SHOW_MEM_FILTER_NODES;
2791 struct va_format vaf;
2794 va_start(args, fmt);
2799 pr_warn("%pV", &vaf);
2804 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2805 current->comm, order, gfp_mask, &gfp_mask);
2807 if (!should_suppress_show_mem())
2811 static inline struct page *
2812 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2813 const struct alloc_context *ac, unsigned long *did_some_progress)
2815 struct oom_control oc = {
2816 .zonelist = ac->zonelist,
2817 .nodemask = ac->nodemask,
2818 .gfp_mask = gfp_mask,
2823 *did_some_progress = 0;
2826 * Acquire the oom lock. If that fails, somebody else is
2827 * making progress for us.
2829 if (!mutex_trylock(&oom_lock)) {
2830 *did_some_progress = 1;
2831 schedule_timeout_uninterruptible(1);
2836 * Go through the zonelist yet one more time, keep very high watermark
2837 * here, this is only to catch a parallel oom killing, we must fail if
2838 * we're still under heavy pressure.
2840 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2841 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2845 if (!(gfp_mask & __GFP_NOFAIL)) {
2846 /* Coredumps can quickly deplete all memory reserves */
2847 if (current->flags & PF_DUMPCORE)
2849 /* The OOM killer will not help higher order allocs */
2850 if (order > PAGE_ALLOC_COSTLY_ORDER)
2852 /* The OOM killer does not needlessly kill tasks for lowmem */
2853 if (ac->high_zoneidx < ZONE_NORMAL)
2855 /* The OOM killer does not compensate for IO-less reclaim */
2856 if (!(gfp_mask & __GFP_FS)) {
2858 * XXX: Page reclaim didn't yield anything,
2859 * and the OOM killer can't be invoked, but
2860 * keep looping as per tradition.
2862 *did_some_progress = 1;
2865 if (pm_suspended_storage())
2867 /* The OOM killer may not free memory on a specific node */
2868 if (gfp_mask & __GFP_THISNODE)
2871 /* Exhausted what can be done so it's blamo time */
2872 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
2873 *did_some_progress = 1;
2875 if (gfp_mask & __GFP_NOFAIL) {
2876 page = get_page_from_freelist(gfp_mask, order,
2877 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
2879 * fallback to ignore cpuset restriction if our nodes
2883 page = get_page_from_freelist(gfp_mask, order,
2884 ALLOC_NO_WATERMARKS, ac);
2888 mutex_unlock(&oom_lock);
2892 #ifdef CONFIG_COMPACTION
2893 /* Try memory compaction for high-order allocations before reclaim */
2894 static struct page *
2895 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2896 int alloc_flags, const struct alloc_context *ac,
2897 enum migrate_mode mode, int *contended_compaction,
2898 bool *deferred_compaction)
2900 unsigned long compact_result;
2906 current->flags |= PF_MEMALLOC;
2907 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2908 mode, contended_compaction);
2909 current->flags &= ~PF_MEMALLOC;
2911 switch (compact_result) {
2912 case COMPACT_DEFERRED:
2913 *deferred_compaction = true;
2915 case COMPACT_SKIPPED:
2922 * At least in one zone compaction wasn't deferred or skipped, so let's
2923 * count a compaction stall
2925 count_vm_event(COMPACTSTALL);
2927 page = get_page_from_freelist(gfp_mask, order,
2928 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2931 struct zone *zone = page_zone(page);
2933 zone->compact_blockskip_flush = false;
2934 compaction_defer_reset(zone, order, true);
2935 count_vm_event(COMPACTSUCCESS);
2940 * It's bad if compaction run occurs and fails. The most likely reason
2941 * is that pages exist, but not enough to satisfy watermarks.
2943 count_vm_event(COMPACTFAIL);
2950 static inline struct page *
2951 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2952 int alloc_flags, const struct alloc_context *ac,
2953 enum migrate_mode mode, int *contended_compaction,
2954 bool *deferred_compaction)
2958 #endif /* CONFIG_COMPACTION */
2960 /* Perform direct synchronous page reclaim */
2962 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
2963 const struct alloc_context *ac)
2965 struct reclaim_state reclaim_state;
2970 /* We now go into synchronous reclaim */
2971 cpuset_memory_pressure_bump();
2972 current->flags |= PF_MEMALLOC;
2973 lockdep_set_current_reclaim_state(gfp_mask);
2974 reclaim_state.reclaimed_slab = 0;
2975 current->reclaim_state = &reclaim_state;
2977 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
2980 current->reclaim_state = NULL;
2981 lockdep_clear_current_reclaim_state();
2982 current->flags &= ~PF_MEMALLOC;
2989 /* The really slow allocator path where we enter direct reclaim */
2990 static inline struct page *
2991 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2992 int alloc_flags, const struct alloc_context *ac,
2993 unsigned long *did_some_progress)
2995 struct page *page = NULL;
2996 bool drained = false;
2998 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
2999 if (unlikely(!(*did_some_progress)))
3003 page = get_page_from_freelist(gfp_mask, order,
3004 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3007 * If an allocation failed after direct reclaim, it could be because
3008 * pages are pinned on the per-cpu lists or in high alloc reserves.
3009 * Shrink them them and try again
3011 if (!page && !drained) {
3012 unreserve_highatomic_pageblock(ac);
3013 drain_all_pages(NULL);
3021 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3026 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3027 ac->high_zoneidx, ac->nodemask)
3028 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
3032 gfp_to_alloc_flags(gfp_t gfp_mask)
3034 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3036 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3037 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3040 * The caller may dip into page reserves a bit more if the caller
3041 * cannot run direct reclaim, or if the caller has realtime scheduling
3042 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3043 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3045 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3047 if (gfp_mask & __GFP_ATOMIC) {
3049 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3050 * if it can't schedule.
3052 if (!(gfp_mask & __GFP_NOMEMALLOC))
3053 alloc_flags |= ALLOC_HARDER;
3055 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3056 * comment for __cpuset_node_allowed().
3058 alloc_flags &= ~ALLOC_CPUSET;
3059 } else if (unlikely(rt_task(current)) && !in_interrupt())
3060 alloc_flags |= ALLOC_HARDER;
3062 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3063 if (gfp_mask & __GFP_MEMALLOC)
3064 alloc_flags |= ALLOC_NO_WATERMARKS;
3065 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3066 alloc_flags |= ALLOC_NO_WATERMARKS;
3067 else if (!in_interrupt() &&
3068 ((current->flags & PF_MEMALLOC) ||
3069 unlikely(test_thread_flag(TIF_MEMDIE))))
3070 alloc_flags |= ALLOC_NO_WATERMARKS;
3073 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3074 alloc_flags |= ALLOC_CMA;
3079 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3081 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3084 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3086 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3089 static inline struct page *
3090 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3091 struct alloc_context *ac)
3093 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3094 struct page *page = NULL;
3096 unsigned long pages_reclaimed = 0;
3097 unsigned long did_some_progress;
3098 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3099 bool deferred_compaction = false;
3100 int contended_compaction = COMPACT_CONTENDED_NONE;
3103 * In the slowpath, we sanity check order to avoid ever trying to
3104 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3105 * be using allocators in order of preference for an area that is
3108 if (order >= MAX_ORDER) {
3109 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3114 * We also sanity check to catch abuse of atomic reserves being used by
3115 * callers that are not in atomic context.
3117 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3118 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3119 gfp_mask &= ~__GFP_ATOMIC;
3122 * If this allocation cannot block and it is for a specific node, then
3123 * fail early. There's no need to wakeup kswapd or retry for a
3124 * speculative node-specific allocation.
3126 if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !can_direct_reclaim)
3130 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3131 wake_all_kswapds(order, ac);
3134 * OK, we're below the kswapd watermark and have kicked background
3135 * reclaim. Now things get more complex, so set up alloc_flags according
3136 * to how we want to proceed.
3138 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3141 * Find the true preferred zone if the allocation is unconstrained by
3144 if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) {
3145 struct zoneref *preferred_zoneref;
3146 preferred_zoneref = first_zones_zonelist(ac->zonelist,
3147 ac->high_zoneidx, NULL, &ac->preferred_zone);
3148 ac->classzone_idx = zonelist_zone_idx(preferred_zoneref);
3151 /* This is the last chance, in general, before the goto nopage. */
3152 page = get_page_from_freelist(gfp_mask, order,
3153 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3157 /* Allocate without watermarks if the context allows */
3158 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3160 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3161 * the allocation is high priority and these type of
3162 * allocations are system rather than user orientated
3164 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3165 page = get_page_from_freelist(gfp_mask, order,
3166 ALLOC_NO_WATERMARKS, ac);
3171 /* Caller is not willing to reclaim, we can't balance anything */
3172 if (!can_direct_reclaim) {
3174 * All existing users of the __GFP_NOFAIL are blockable, so warn
3175 * of any new users that actually allow this type of allocation
3178 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3182 /* Avoid recursion of direct reclaim */
3183 if (current->flags & PF_MEMALLOC) {
3185 * __GFP_NOFAIL request from this context is rather bizarre
3186 * because we cannot reclaim anything and only can loop waiting
3187 * for somebody to do a work for us.
3189 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3196 /* Avoid allocations with no watermarks from looping endlessly */
3197 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3201 * Try direct compaction. The first pass is asynchronous. Subsequent
3202 * attempts after direct reclaim are synchronous
3204 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3206 &contended_compaction,
3207 &deferred_compaction);
3211 /* Checks for THP-specific high-order allocations */
3212 if (is_thp_gfp_mask(gfp_mask)) {
3214 * If compaction is deferred for high-order allocations, it is
3215 * because sync compaction recently failed. If this is the case
3216 * and the caller requested a THP allocation, we do not want
3217 * to heavily disrupt the system, so we fail the allocation
3218 * instead of entering direct reclaim.
3220 if (deferred_compaction)
3224 * In all zones where compaction was attempted (and not
3225 * deferred or skipped), lock contention has been detected.
3226 * For THP allocation we do not want to disrupt the others
3227 * so we fallback to base pages instead.
3229 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3233 * If compaction was aborted due to need_resched(), we do not
3234 * want to further increase allocation latency, unless it is
3235 * khugepaged trying to collapse.
3237 if (contended_compaction == COMPACT_CONTENDED_SCHED
3238 && !(current->flags & PF_KTHREAD))
3243 * It can become very expensive to allocate transparent hugepages at
3244 * fault, so use asynchronous memory compaction for THP unless it is
3245 * khugepaged trying to collapse.
3247 if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
3248 migration_mode = MIGRATE_SYNC_LIGHT;
3250 /* Try direct reclaim and then allocating */
3251 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3252 &did_some_progress);
3256 /* Do not loop if specifically requested */
3257 if (gfp_mask & __GFP_NORETRY)
3260 /* Keep reclaiming pages as long as there is reasonable progress */
3261 pages_reclaimed += did_some_progress;
3262 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3263 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3264 /* Wait for some write requests to complete then retry */
3265 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
3269 /* Reclaim has failed us, start killing things */
3270 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3274 /* Retry as long as the OOM killer is making progress */
3275 if (did_some_progress)
3280 * High-order allocations do not necessarily loop after
3281 * direct reclaim and reclaim/compaction depends on compaction
3282 * being called after reclaim so call directly if necessary
3284 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3286 &contended_compaction,
3287 &deferred_compaction);
3291 warn_alloc_failed(gfp_mask, order, NULL);
3297 * This is the 'heart' of the zoned buddy allocator.
3300 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3301 struct zonelist *zonelist, nodemask_t *nodemask)
3303 struct zoneref *preferred_zoneref;
3304 struct page *page = NULL;
3305 unsigned int cpuset_mems_cookie;
3306 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
3307 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
3308 struct alloc_context ac = {
3309 .high_zoneidx = gfp_zone(gfp_mask),
3310 .nodemask = nodemask,
3311 .migratetype = gfpflags_to_migratetype(gfp_mask),
3314 gfp_mask &= gfp_allowed_mask;
3316 lockdep_trace_alloc(gfp_mask);
3318 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3320 if (should_fail_alloc_page(gfp_mask, order))
3324 * Check the zones suitable for the gfp_mask contain at least one
3325 * valid zone. It's possible to have an empty zonelist as a result
3326 * of __GFP_THISNODE and a memoryless node
3328 if (unlikely(!zonelist->_zonerefs->zone))
3331 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3332 alloc_flags |= ALLOC_CMA;
3335 cpuset_mems_cookie = read_mems_allowed_begin();
3337 /* We set it here, as __alloc_pages_slowpath might have changed it */
3338 ac.zonelist = zonelist;
3340 /* Dirty zone balancing only done in the fast path */
3341 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3343 /* The preferred zone is used for statistics later */
3344 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
3345 ac.nodemask ? : &cpuset_current_mems_allowed,
3346 &ac.preferred_zone);
3347 if (!ac.preferred_zone)
3349 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
3351 /* First allocation attempt */
3352 alloc_mask = gfp_mask|__GFP_HARDWALL;
3353 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3354 if (unlikely(!page)) {
3356 * Runtime PM, block IO and its error handling path
3357 * can deadlock because I/O on the device might not
3360 alloc_mask = memalloc_noio_flags(gfp_mask);
3361 ac.spread_dirty_pages = false;
3363 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3366 if (kmemcheck_enabled && page)
3367 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3369 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3373 * When updating a task's mems_allowed, it is possible to race with
3374 * parallel threads in such a way that an allocation can fail while
3375 * the mask is being updated. If a page allocation is about to fail,
3376 * check if the cpuset changed during allocation and if so, retry.
3378 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
3383 EXPORT_SYMBOL(__alloc_pages_nodemask);
3386 * Common helper functions.
3388 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3393 * __get_free_pages() returns a 32-bit address, which cannot represent
3396 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3398 page = alloc_pages(gfp_mask, order);
3401 return (unsigned long) page_address(page);
3403 EXPORT_SYMBOL(__get_free_pages);
3405 unsigned long get_zeroed_page(gfp_t gfp_mask)
3407 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3409 EXPORT_SYMBOL(get_zeroed_page);
3411 void __free_pages(struct page *page, unsigned int order)
3413 if (put_page_testzero(page)) {
3415 free_hot_cold_page(page, false);
3417 __free_pages_ok(page, order);
3421 EXPORT_SYMBOL(__free_pages);
3423 void free_pages(unsigned long addr, unsigned int order)
3426 VM_BUG_ON(!virt_addr_valid((void *)addr));
3427 __free_pages(virt_to_page((void *)addr), order);
3431 EXPORT_SYMBOL(free_pages);
3435 * An arbitrary-length arbitrary-offset area of memory which resides
3436 * within a 0 or higher order page. Multiple fragments within that page
3437 * are individually refcounted, in the page's reference counter.
3439 * The page_frag functions below provide a simple allocation framework for
3440 * page fragments. This is used by the network stack and network device
3441 * drivers to provide a backing region of memory for use as either an
3442 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3444 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3447 struct page *page = NULL;
3448 gfp_t gfp = gfp_mask;
3450 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3451 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3453 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3454 PAGE_FRAG_CACHE_MAX_ORDER);
3455 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3457 if (unlikely(!page))
3458 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3460 nc->va = page ? page_address(page) : NULL;
3465 void *__alloc_page_frag(struct page_frag_cache *nc,
3466 unsigned int fragsz, gfp_t gfp_mask)
3468 unsigned int size = PAGE_SIZE;
3472 if (unlikely(!nc->va)) {
3474 page = __page_frag_refill(nc, gfp_mask);
3478 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3479 /* if size can vary use size else just use PAGE_SIZE */
3482 /* Even if we own the page, we do not use atomic_set().
3483 * This would break get_page_unless_zero() users.
3485 atomic_add(size - 1, &page->_count);
3487 /* reset page count bias and offset to start of new frag */
3488 nc->pfmemalloc = page_is_pfmemalloc(page);
3489 nc->pagecnt_bias = size;
3493 offset = nc->offset - fragsz;
3494 if (unlikely(offset < 0)) {
3495 page = virt_to_page(nc->va);
3497 if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count))
3500 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3501 /* if size can vary use size else just use PAGE_SIZE */
3504 /* OK, page count is 0, we can safely set it */
3505 atomic_set(&page->_count, size);
3507 /* reset page count bias and offset to start of new frag */
3508 nc->pagecnt_bias = size;
3509 offset = size - fragsz;
3513 nc->offset = offset;
3515 return nc->va + offset;
3517 EXPORT_SYMBOL(__alloc_page_frag);
3520 * Frees a page fragment allocated out of either a compound or order 0 page.
3522 void __free_page_frag(void *addr)
3524 struct page *page = virt_to_head_page(addr);
3526 if (unlikely(put_page_testzero(page)))
3527 __free_pages_ok(page, compound_order(page));
3529 EXPORT_SYMBOL(__free_page_frag);
3532 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3533 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3534 * equivalent to alloc_pages.
3536 * It should be used when the caller would like to use kmalloc, but since the
3537 * allocation is large, it has to fall back to the page allocator.
3539 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3543 page = alloc_pages(gfp_mask, order);
3544 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3545 __free_pages(page, order);
3551 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3555 page = alloc_pages_node(nid, gfp_mask, order);
3556 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3557 __free_pages(page, order);
3564 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3567 void __free_kmem_pages(struct page *page, unsigned int order)
3569 memcg_kmem_uncharge(page, order);
3570 __free_pages(page, order);
3573 void free_kmem_pages(unsigned long addr, unsigned int order)
3576 VM_BUG_ON(!virt_addr_valid((void *)addr));
3577 __free_kmem_pages(virt_to_page((void *)addr), order);
3581 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3585 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3586 unsigned long used = addr + PAGE_ALIGN(size);
3588 split_page(virt_to_page((void *)addr), order);
3589 while (used < alloc_end) {
3594 return (void *)addr;
3598 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3599 * @size: the number of bytes to allocate
3600 * @gfp_mask: GFP flags for the allocation
3602 * This function is similar to alloc_pages(), except that it allocates the
3603 * minimum number of pages to satisfy the request. alloc_pages() can only
3604 * allocate memory in power-of-two pages.
3606 * This function is also limited by MAX_ORDER.
3608 * Memory allocated by this function must be released by free_pages_exact().
3610 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3612 unsigned int order = get_order(size);
3615 addr = __get_free_pages(gfp_mask, order);
3616 return make_alloc_exact(addr, order, size);
3618 EXPORT_SYMBOL(alloc_pages_exact);
3621 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3623 * @nid: the preferred node ID where memory should be allocated
3624 * @size: the number of bytes to allocate
3625 * @gfp_mask: GFP flags for the allocation
3627 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3630 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3632 unsigned int order = get_order(size);
3633 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3636 return make_alloc_exact((unsigned long)page_address(p), order, size);
3640 * free_pages_exact - release memory allocated via alloc_pages_exact()
3641 * @virt: the value returned by alloc_pages_exact.
3642 * @size: size of allocation, same value as passed to alloc_pages_exact().
3644 * Release the memory allocated by a previous call to alloc_pages_exact.
3646 void free_pages_exact(void *virt, size_t size)
3648 unsigned long addr = (unsigned long)virt;
3649 unsigned long end = addr + PAGE_ALIGN(size);
3651 while (addr < end) {
3656 EXPORT_SYMBOL(free_pages_exact);
3659 * nr_free_zone_pages - count number of pages beyond high watermark
3660 * @offset: The zone index of the highest zone
3662 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3663 * high watermark within all zones at or below a given zone index. For each
3664 * zone, the number of pages is calculated as:
3665 * managed_pages - high_pages
3667 static unsigned long nr_free_zone_pages(int offset)
3672 /* Just pick one node, since fallback list is circular */
3673 unsigned long sum = 0;
3675 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3677 for_each_zone_zonelist(zone, z, zonelist, offset) {
3678 unsigned long size = zone->managed_pages;
3679 unsigned long high = high_wmark_pages(zone);
3688 * nr_free_buffer_pages - count number of pages beyond high watermark
3690 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3691 * watermark within ZONE_DMA and ZONE_NORMAL.
3693 unsigned long nr_free_buffer_pages(void)
3695 return nr_free_zone_pages(gfp_zone(GFP_USER));
3697 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3700 * nr_free_pagecache_pages - count number of pages beyond high watermark
3702 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3703 * high watermark within all zones.
3705 unsigned long nr_free_pagecache_pages(void)
3707 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3710 static inline void show_node(struct zone *zone)
3712 if (IS_ENABLED(CONFIG_NUMA))
3713 printk("Node %d ", zone_to_nid(zone));
3716 long si_mem_available(void)
3719 unsigned long pagecache;
3720 unsigned long wmark_low = 0;
3721 unsigned long pages[NR_LRU_LISTS];
3725 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
3726 pages[lru] = global_page_state(NR_LRU_BASE + lru);
3729 wmark_low += zone->watermark[WMARK_LOW];
3732 * Estimate the amount of memory available for userspace allocations,
3733 * without causing swapping.
3735 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
3738 * Not all the page cache can be freed, otherwise the system will
3739 * start swapping. Assume at least half of the page cache, or the
3740 * low watermark worth of cache, needs to stay.
3742 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
3743 pagecache -= min(pagecache / 2, wmark_low);
3744 available += pagecache;
3747 * Part of the reclaimable slab consists of items that are in use,
3748 * and cannot be freed. Cap this estimate at the low watermark.
3750 available += global_page_state(NR_SLAB_RECLAIMABLE) -
3751 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
3757 EXPORT_SYMBOL_GPL(si_mem_available);
3759 void si_meminfo(struct sysinfo *val)
3761 val->totalram = totalram_pages;
3762 val->sharedram = global_page_state(NR_SHMEM);
3763 val->freeram = global_page_state(NR_FREE_PAGES);
3764 val->bufferram = nr_blockdev_pages();
3765 val->totalhigh = totalhigh_pages;
3766 val->freehigh = nr_free_highpages();
3767 val->mem_unit = PAGE_SIZE;
3770 EXPORT_SYMBOL(si_meminfo);
3773 void si_meminfo_node(struct sysinfo *val, int nid)
3775 int zone_type; /* needs to be signed */
3776 unsigned long managed_pages = 0;
3777 pg_data_t *pgdat = NODE_DATA(nid);
3779 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3780 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3781 val->totalram = managed_pages;
3782 val->sharedram = node_page_state(nid, NR_SHMEM);
3783 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3784 #ifdef CONFIG_HIGHMEM
3785 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3786 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3792 val->mem_unit = PAGE_SIZE;
3797 * Determine whether the node should be displayed or not, depending on whether
3798 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3800 bool skip_free_areas_node(unsigned int flags, int nid)
3803 unsigned int cpuset_mems_cookie;
3805 if (!(flags & SHOW_MEM_FILTER_NODES))
3809 cpuset_mems_cookie = read_mems_allowed_begin();
3810 ret = !node_isset(nid, cpuset_current_mems_allowed);
3811 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3816 #define K(x) ((x) << (PAGE_SHIFT-10))
3818 static void show_migration_types(unsigned char type)
3820 static const char types[MIGRATE_TYPES] = {
3821 [MIGRATE_UNMOVABLE] = 'U',
3822 [MIGRATE_MOVABLE] = 'M',
3823 [MIGRATE_RECLAIMABLE] = 'E',
3824 [MIGRATE_HIGHATOMIC] = 'H',
3826 [MIGRATE_CMA] = 'C',
3828 #ifdef CONFIG_MEMORY_ISOLATION
3829 [MIGRATE_ISOLATE] = 'I',
3832 char tmp[MIGRATE_TYPES + 1];
3836 for (i = 0; i < MIGRATE_TYPES; i++) {
3837 if (type & (1 << i))
3842 printk("(%s) ", tmp);
3846 * Show free area list (used inside shift_scroll-lock stuff)
3847 * We also calculate the percentage fragmentation. We do this by counting the
3848 * memory on each free list with the exception of the first item on the list.
3851 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3854 void show_free_areas(unsigned int filter)
3856 unsigned long free_pcp = 0;
3860 for_each_populated_zone(zone) {
3861 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3864 for_each_online_cpu(cpu)
3865 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3868 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3869 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3870 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3871 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3872 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3873 " free:%lu free_pcp:%lu free_cma:%lu\n",
3874 global_page_state(NR_ACTIVE_ANON),
3875 global_page_state(NR_INACTIVE_ANON),
3876 global_page_state(NR_ISOLATED_ANON),
3877 global_page_state(NR_ACTIVE_FILE),
3878 global_page_state(NR_INACTIVE_FILE),
3879 global_page_state(NR_ISOLATED_FILE),
3880 global_page_state(NR_UNEVICTABLE),
3881 global_page_state(NR_FILE_DIRTY),
3882 global_page_state(NR_WRITEBACK),
3883 global_page_state(NR_UNSTABLE_NFS),
3884 global_page_state(NR_SLAB_RECLAIMABLE),
3885 global_page_state(NR_SLAB_UNRECLAIMABLE),
3886 global_page_state(NR_FILE_MAPPED),
3887 global_page_state(NR_SHMEM),
3888 global_page_state(NR_PAGETABLE),
3889 global_page_state(NR_BOUNCE),
3890 global_page_state(NR_FREE_PAGES),
3892 global_page_state(NR_FREE_CMA_PAGES));
3894 for_each_populated_zone(zone) {
3897 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3901 for_each_online_cpu(cpu)
3902 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3910 " active_anon:%lukB"
3911 " inactive_anon:%lukB"
3912 " active_file:%lukB"
3913 " inactive_file:%lukB"
3914 " unevictable:%lukB"
3915 " isolated(anon):%lukB"
3916 " isolated(file):%lukB"
3924 " slab_reclaimable:%lukB"
3925 " slab_unreclaimable:%lukB"
3926 " kernel_stack:%lukB"
3933 " writeback_tmp:%lukB"
3934 " pages_scanned:%lu"
3935 " all_unreclaimable? %s"
3938 K(zone_page_state(zone, NR_FREE_PAGES)),
3939 K(min_wmark_pages(zone)),
3940 K(low_wmark_pages(zone)),
3941 K(high_wmark_pages(zone)),
3942 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3943 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3944 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3945 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3946 K(zone_page_state(zone, NR_UNEVICTABLE)),
3947 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3948 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3949 K(zone->present_pages),
3950 K(zone->managed_pages),
3951 K(zone_page_state(zone, NR_MLOCK)),
3952 K(zone_page_state(zone, NR_FILE_DIRTY)),
3953 K(zone_page_state(zone, NR_WRITEBACK)),
3954 K(zone_page_state(zone, NR_FILE_MAPPED)),
3955 K(zone_page_state(zone, NR_SHMEM)),
3956 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3957 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3958 zone_page_state(zone, NR_KERNEL_STACK) *
3960 K(zone_page_state(zone, NR_PAGETABLE)),
3961 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3962 K(zone_page_state(zone, NR_BOUNCE)),
3964 K(this_cpu_read(zone->pageset->pcp.count)),
3965 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3966 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3967 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3968 (!zone_reclaimable(zone) ? "yes" : "no")
3970 printk("lowmem_reserve[]:");
3971 for (i = 0; i < MAX_NR_ZONES; i++)
3972 printk(" %ld", zone->lowmem_reserve[i]);
3976 for_each_populated_zone(zone) {
3978 unsigned long nr[MAX_ORDER], flags, total = 0;
3979 unsigned char types[MAX_ORDER];
3981 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3984 printk("%s: ", zone->name);
3986 spin_lock_irqsave(&zone->lock, flags);
3987 for (order = 0; order < MAX_ORDER; order++) {
3988 struct free_area *area = &zone->free_area[order];
3991 nr[order] = area->nr_free;
3992 total += nr[order] << order;
3995 for (type = 0; type < MIGRATE_TYPES; type++) {
3996 if (!list_empty(&area->free_list[type]))
3997 types[order] |= 1 << type;
4000 spin_unlock_irqrestore(&zone->lock, flags);
4001 for (order = 0; order < MAX_ORDER; order++) {
4002 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4004 show_migration_types(types[order]);
4006 printk("= %lukB\n", K(total));
4009 hugetlb_show_meminfo();
4011 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4013 show_swap_cache_info();
4016 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4018 zoneref->zone = zone;
4019 zoneref->zone_idx = zone_idx(zone);
4023 * Builds allocation fallback zone lists.
4025 * Add all populated zones of a node to the zonelist.
4027 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4031 enum zone_type zone_type = MAX_NR_ZONES;
4035 zone = pgdat->node_zones + zone_type;
4036 if (populated_zone(zone)) {
4037 zoneref_set_zone(zone,
4038 &zonelist->_zonerefs[nr_zones++]);
4039 check_highest_zone(zone_type);
4041 } while (zone_type);
4049 * 0 = automatic detection of better ordering.
4050 * 1 = order by ([node] distance, -zonetype)
4051 * 2 = order by (-zonetype, [node] distance)
4053 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4054 * the same zonelist. So only NUMA can configure this param.
4056 #define ZONELIST_ORDER_DEFAULT 0
4057 #define ZONELIST_ORDER_NODE 1
4058 #define ZONELIST_ORDER_ZONE 2
4060 /* zonelist order in the kernel.
4061 * set_zonelist_order() will set this to NODE or ZONE.
4063 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4064 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4068 /* The value user specified ....changed by config */
4069 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4070 /* string for sysctl */
4071 #define NUMA_ZONELIST_ORDER_LEN 16
4072 char numa_zonelist_order[16] = "default";
4075 * interface for configure zonelist ordering.
4076 * command line option "numa_zonelist_order"
4077 * = "[dD]efault - default, automatic configuration.
4078 * = "[nN]ode - order by node locality, then by zone within node
4079 * = "[zZ]one - order by zone, then by locality within zone
4082 static int __parse_numa_zonelist_order(char *s)
4084 if (*s == 'd' || *s == 'D') {
4085 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4086 } else if (*s == 'n' || *s == 'N') {
4087 user_zonelist_order = ZONELIST_ORDER_NODE;
4088 } else if (*s == 'z' || *s == 'Z') {
4089 user_zonelist_order = ZONELIST_ORDER_ZONE;
4092 "Ignoring invalid numa_zonelist_order value: "
4099 static __init int setup_numa_zonelist_order(char *s)
4106 ret = __parse_numa_zonelist_order(s);
4108 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4112 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4115 * sysctl handler for numa_zonelist_order
4117 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4118 void __user *buffer, size_t *length,
4121 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4123 static DEFINE_MUTEX(zl_order_mutex);
4125 mutex_lock(&zl_order_mutex);
4127 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4131 strcpy(saved_string, (char *)table->data);
4133 ret = proc_dostring(table, write, buffer, length, ppos);
4137 int oldval = user_zonelist_order;
4139 ret = __parse_numa_zonelist_order((char *)table->data);
4142 * bogus value. restore saved string
4144 strncpy((char *)table->data, saved_string,
4145 NUMA_ZONELIST_ORDER_LEN);
4146 user_zonelist_order = oldval;
4147 } else if (oldval != user_zonelist_order) {
4148 mutex_lock(&zonelists_mutex);
4149 build_all_zonelists(NULL, NULL);
4150 mutex_unlock(&zonelists_mutex);
4154 mutex_unlock(&zl_order_mutex);
4159 #define MAX_NODE_LOAD (nr_online_nodes)
4160 static int node_load[MAX_NUMNODES];
4163 * find_next_best_node - find the next node that should appear in a given node's fallback list
4164 * @node: node whose fallback list we're appending
4165 * @used_node_mask: nodemask_t of already used nodes
4167 * We use a number of factors to determine which is the next node that should
4168 * appear on a given node's fallback list. The node should not have appeared
4169 * already in @node's fallback list, and it should be the next closest node
4170 * according to the distance array (which contains arbitrary distance values
4171 * from each node to each node in the system), and should also prefer nodes
4172 * with no CPUs, since presumably they'll have very little allocation pressure
4173 * on them otherwise.
4174 * It returns -1 if no node is found.
4176 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4179 int min_val = INT_MAX;
4180 int best_node = NUMA_NO_NODE;
4181 const struct cpumask *tmp = cpumask_of_node(0);
4183 /* Use the local node if we haven't already */
4184 if (!node_isset(node, *used_node_mask)) {
4185 node_set(node, *used_node_mask);
4189 for_each_node_state(n, N_MEMORY) {
4191 /* Don't want a node to appear more than once */
4192 if (node_isset(n, *used_node_mask))
4195 /* Use the distance array to find the distance */
4196 val = node_distance(node, n);
4198 /* Penalize nodes under us ("prefer the next node") */
4201 /* Give preference to headless and unused nodes */
4202 tmp = cpumask_of_node(n);
4203 if (!cpumask_empty(tmp))
4204 val += PENALTY_FOR_NODE_WITH_CPUS;
4206 /* Slight preference for less loaded node */
4207 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4208 val += node_load[n];
4210 if (val < min_val) {
4217 node_set(best_node, *used_node_mask);
4224 * Build zonelists ordered by node and zones within node.
4225 * This results in maximum locality--normal zone overflows into local
4226 * DMA zone, if any--but risks exhausting DMA zone.
4228 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4231 struct zonelist *zonelist;
4233 zonelist = &pgdat->node_zonelists[0];
4234 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4236 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4237 zonelist->_zonerefs[j].zone = NULL;
4238 zonelist->_zonerefs[j].zone_idx = 0;
4242 * Build gfp_thisnode zonelists
4244 static void build_thisnode_zonelists(pg_data_t *pgdat)
4247 struct zonelist *zonelist;
4249 zonelist = &pgdat->node_zonelists[1];
4250 j = build_zonelists_node(pgdat, zonelist, 0);
4251 zonelist->_zonerefs[j].zone = NULL;
4252 zonelist->_zonerefs[j].zone_idx = 0;
4256 * Build zonelists ordered by zone and nodes within zones.
4257 * This results in conserving DMA zone[s] until all Normal memory is
4258 * exhausted, but results in overflowing to remote node while memory
4259 * may still exist in local DMA zone.
4261 static int node_order[MAX_NUMNODES];
4263 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4266 int zone_type; /* needs to be signed */
4268 struct zonelist *zonelist;
4270 zonelist = &pgdat->node_zonelists[0];
4272 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4273 for (j = 0; j < nr_nodes; j++) {
4274 node = node_order[j];
4275 z = &NODE_DATA(node)->node_zones[zone_type];
4276 if (populated_zone(z)) {
4278 &zonelist->_zonerefs[pos++]);
4279 check_highest_zone(zone_type);
4283 zonelist->_zonerefs[pos].zone = NULL;
4284 zonelist->_zonerefs[pos].zone_idx = 0;
4287 #if defined(CONFIG_64BIT)
4289 * Devices that require DMA32/DMA are relatively rare and do not justify a
4290 * penalty to every machine in case the specialised case applies. Default
4291 * to Node-ordering on 64-bit NUMA machines
4293 static int default_zonelist_order(void)
4295 return ZONELIST_ORDER_NODE;
4299 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4300 * by the kernel. If processes running on node 0 deplete the low memory zone
4301 * then reclaim will occur more frequency increasing stalls and potentially
4302 * be easier to OOM if a large percentage of the zone is under writeback or
4303 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4304 * Hence, default to zone ordering on 32-bit.
4306 static int default_zonelist_order(void)
4308 return ZONELIST_ORDER_ZONE;
4310 #endif /* CONFIG_64BIT */
4312 static void set_zonelist_order(void)
4314 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4315 current_zonelist_order = default_zonelist_order();
4317 current_zonelist_order = user_zonelist_order;
4320 static void build_zonelists(pg_data_t *pgdat)
4323 nodemask_t used_mask;
4324 int local_node, prev_node;
4325 struct zonelist *zonelist;
4326 unsigned int order = current_zonelist_order;
4328 /* initialize zonelists */
4329 for (i = 0; i < MAX_ZONELISTS; i++) {
4330 zonelist = pgdat->node_zonelists + i;
4331 zonelist->_zonerefs[0].zone = NULL;
4332 zonelist->_zonerefs[0].zone_idx = 0;
4335 /* NUMA-aware ordering of nodes */
4336 local_node = pgdat->node_id;
4337 load = nr_online_nodes;
4338 prev_node = local_node;
4339 nodes_clear(used_mask);
4341 memset(node_order, 0, sizeof(node_order));
4344 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4346 * We don't want to pressure a particular node.
4347 * So adding penalty to the first node in same
4348 * distance group to make it round-robin.
4350 if (node_distance(local_node, node) !=
4351 node_distance(local_node, prev_node))
4352 node_load[node] = load;
4356 if (order == ZONELIST_ORDER_NODE)
4357 build_zonelists_in_node_order(pgdat, node);
4359 node_order[i++] = node; /* remember order */
4362 if (order == ZONELIST_ORDER_ZONE) {
4363 /* calculate node order -- i.e., DMA last! */
4364 build_zonelists_in_zone_order(pgdat, i);
4367 build_thisnode_zonelists(pgdat);
4370 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4372 * Return node id of node used for "local" allocations.
4373 * I.e., first node id of first zone in arg node's generic zonelist.
4374 * Used for initializing percpu 'numa_mem', which is used primarily
4375 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4377 int local_memory_node(int node)
4381 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4382 gfp_zone(GFP_KERNEL),
4389 #else /* CONFIG_NUMA */
4391 static void set_zonelist_order(void)
4393 current_zonelist_order = ZONELIST_ORDER_ZONE;
4396 static void build_zonelists(pg_data_t *pgdat)
4398 int node, local_node;
4400 struct zonelist *zonelist;
4402 local_node = pgdat->node_id;
4404 zonelist = &pgdat->node_zonelists[0];
4405 j = build_zonelists_node(pgdat, zonelist, 0);
4408 * Now we build the zonelist so that it contains the zones
4409 * of all the other nodes.
4410 * We don't want to pressure a particular node, so when
4411 * building the zones for node N, we make sure that the
4412 * zones coming right after the local ones are those from
4413 * node N+1 (modulo N)
4415 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4416 if (!node_online(node))
4418 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4420 for (node = 0; node < local_node; node++) {
4421 if (!node_online(node))
4423 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4426 zonelist->_zonerefs[j].zone = NULL;
4427 zonelist->_zonerefs[j].zone_idx = 0;
4430 #endif /* CONFIG_NUMA */
4433 * Boot pageset table. One per cpu which is going to be used for all
4434 * zones and all nodes. The parameters will be set in such a way
4435 * that an item put on a list will immediately be handed over to
4436 * the buddy list. This is safe since pageset manipulation is done
4437 * with interrupts disabled.
4439 * The boot_pagesets must be kept even after bootup is complete for
4440 * unused processors and/or zones. They do play a role for bootstrapping
4441 * hotplugged processors.
4443 * zoneinfo_show() and maybe other functions do
4444 * not check if the processor is online before following the pageset pointer.
4445 * Other parts of the kernel may not check if the zone is available.
4447 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4448 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4449 static void setup_zone_pageset(struct zone *zone);
4452 * Global mutex to protect against size modification of zonelists
4453 * as well as to serialize pageset setup for the new populated zone.
4455 DEFINE_MUTEX(zonelists_mutex);
4457 /* return values int ....just for stop_machine() */
4458 static int __build_all_zonelists(void *data)
4462 pg_data_t *self = data;
4465 memset(node_load, 0, sizeof(node_load));
4468 if (self && !node_online(self->node_id)) {
4469 build_zonelists(self);
4472 for_each_online_node(nid) {
4473 pg_data_t *pgdat = NODE_DATA(nid);
4475 build_zonelists(pgdat);
4479 * Initialize the boot_pagesets that are going to be used
4480 * for bootstrapping processors. The real pagesets for
4481 * each zone will be allocated later when the per cpu
4482 * allocator is available.
4484 * boot_pagesets are used also for bootstrapping offline
4485 * cpus if the system is already booted because the pagesets
4486 * are needed to initialize allocators on a specific cpu too.
4487 * F.e. the percpu allocator needs the page allocator which
4488 * needs the percpu allocator in order to allocate its pagesets
4489 * (a chicken-egg dilemma).
4491 for_each_possible_cpu(cpu) {
4492 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4494 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4496 * We now know the "local memory node" for each node--
4497 * i.e., the node of the first zone in the generic zonelist.
4498 * Set up numa_mem percpu variable for on-line cpus. During
4499 * boot, only the boot cpu should be on-line; we'll init the
4500 * secondary cpus' numa_mem as they come on-line. During
4501 * node/memory hotplug, we'll fixup all on-line cpus.
4503 if (cpu_online(cpu))
4504 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4511 static noinline void __init
4512 build_all_zonelists_init(void)
4514 __build_all_zonelists(NULL);
4515 mminit_verify_zonelist();
4516 cpuset_init_current_mems_allowed();
4520 * Called with zonelists_mutex held always
4521 * unless system_state == SYSTEM_BOOTING.
4523 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4524 * [we're only called with non-NULL zone through __meminit paths] and
4525 * (2) call of __init annotated helper build_all_zonelists_init
4526 * [protected by SYSTEM_BOOTING].
4528 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4530 set_zonelist_order();
4532 if (system_state == SYSTEM_BOOTING) {
4533 build_all_zonelists_init();
4535 #ifdef CONFIG_MEMORY_HOTPLUG
4537 setup_zone_pageset(zone);
4539 /* we have to stop all cpus to guarantee there is no user
4541 stop_machine(__build_all_zonelists, pgdat, NULL);
4542 /* cpuset refresh routine should be here */
4544 vm_total_pages = nr_free_pagecache_pages();
4546 * Disable grouping by mobility if the number of pages in the
4547 * system is too low to allow the mechanism to work. It would be
4548 * more accurate, but expensive to check per-zone. This check is
4549 * made on memory-hotadd so a system can start with mobility
4550 * disabled and enable it later
4552 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4553 page_group_by_mobility_disabled = 1;
4555 page_group_by_mobility_disabled = 0;
4557 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4558 "Total pages: %ld\n",
4560 zonelist_order_name[current_zonelist_order],
4561 page_group_by_mobility_disabled ? "off" : "on",
4564 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4569 * Helper functions to size the waitqueue hash table.
4570 * Essentially these want to choose hash table sizes sufficiently
4571 * large so that collisions trying to wait on pages are rare.
4572 * But in fact, the number of active page waitqueues on typical
4573 * systems is ridiculously low, less than 200. So this is even
4574 * conservative, even though it seems large.
4576 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4577 * waitqueues, i.e. the size of the waitq table given the number of pages.
4579 #define PAGES_PER_WAITQUEUE 256
4581 #ifndef CONFIG_MEMORY_HOTPLUG
4582 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4584 unsigned long size = 1;
4586 pages /= PAGES_PER_WAITQUEUE;
4588 while (size < pages)
4592 * Once we have dozens or even hundreds of threads sleeping
4593 * on IO we've got bigger problems than wait queue collision.
4594 * Limit the size of the wait table to a reasonable size.
4596 size = min(size, 4096UL);
4598 return max(size, 4UL);
4602 * A zone's size might be changed by hot-add, so it is not possible to determine
4603 * a suitable size for its wait_table. So we use the maximum size now.
4605 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4607 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4608 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4609 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4611 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4612 * or more by the traditional way. (See above). It equals:
4614 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4615 * ia64(16K page size) : = ( 8G + 4M)byte.
4616 * powerpc (64K page size) : = (32G +16M)byte.
4618 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4625 * This is an integer logarithm so that shifts can be used later
4626 * to extract the more random high bits from the multiplicative
4627 * hash function before the remainder is taken.
4629 static inline unsigned long wait_table_bits(unsigned long size)
4635 * Initially all pages are reserved - free ones are freed
4636 * up by free_all_bootmem() once the early boot process is
4637 * done. Non-atomic initialization, single-pass.
4639 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4640 unsigned long start_pfn, enum memmap_context context)
4642 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
4643 unsigned long end_pfn = start_pfn + size;
4644 pg_data_t *pgdat = NODE_DATA(nid);
4646 unsigned long nr_initialised = 0;
4647 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4648 struct memblock_region *r = NULL, *tmp;
4651 if (highest_memmap_pfn < end_pfn - 1)
4652 highest_memmap_pfn = end_pfn - 1;
4655 * Honor reservation requested by the driver for this ZONE_DEVICE
4658 if (altmap && start_pfn == altmap->base_pfn)
4659 start_pfn += altmap->reserve;
4661 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4663 * There can be holes in boot-time mem_map[]s handed to this
4664 * function. They do not exist on hotplugged memory.
4666 if (context != MEMMAP_EARLY)
4669 if (!early_pfn_valid(pfn))
4671 if (!early_pfn_in_nid(pfn, nid))
4673 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
4676 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4678 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4679 * from zone_movable_pfn[nid] to end of each node should be
4680 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4682 if (!mirrored_kernelcore && zone_movable_pfn[nid])
4683 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
4687 * Check given memblock attribute by firmware which can affect
4688 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4689 * mirrored, it's an overlapped memmap init. skip it.
4691 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
4692 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
4693 for_each_memblock(memory, tmp)
4694 if (pfn < memblock_region_memory_end_pfn(tmp))
4698 if (pfn >= memblock_region_memory_base_pfn(r) &&
4699 memblock_is_mirror(r)) {
4700 /* already initialized as NORMAL */
4701 pfn = memblock_region_memory_end_pfn(r);
4709 * Mark the block movable so that blocks are reserved for
4710 * movable at startup. This will force kernel allocations
4711 * to reserve their blocks rather than leaking throughout
4712 * the address space during boot when many long-lived
4713 * kernel allocations are made.
4715 * bitmap is created for zone's valid pfn range. but memmap
4716 * can be created for invalid pages (for alignment)
4717 * check here not to call set_pageblock_migratetype() against
4720 if (!(pfn & (pageblock_nr_pages - 1))) {
4721 struct page *page = pfn_to_page(pfn);
4723 __init_single_page(page, pfn, zone, nid);
4724 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4726 __init_single_pfn(pfn, zone, nid);
4731 static void __meminit zone_init_free_lists(struct zone *zone)
4733 unsigned int order, t;
4734 for_each_migratetype_order(order, t) {
4735 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4736 zone->free_area[order].nr_free = 0;
4740 #ifndef __HAVE_ARCH_MEMMAP_INIT
4741 #define memmap_init(size, nid, zone, start_pfn) \
4742 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4745 static int zone_batchsize(struct zone *zone)
4751 * The per-cpu-pages pools are set to around 1000th of the
4752 * size of the zone. But no more than 1/2 of a meg.
4754 * OK, so we don't know how big the cache is. So guess.
4756 batch = zone->managed_pages / 1024;
4757 if (batch * PAGE_SIZE > 512 * 1024)
4758 batch = (512 * 1024) / PAGE_SIZE;
4759 batch /= 4; /* We effectively *= 4 below */
4764 * Clamp the batch to a 2^n - 1 value. Having a power
4765 * of 2 value was found to be more likely to have
4766 * suboptimal cache aliasing properties in some cases.
4768 * For example if 2 tasks are alternately allocating
4769 * batches of pages, one task can end up with a lot
4770 * of pages of one half of the possible page colors
4771 * and the other with pages of the other colors.
4773 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4778 /* The deferral and batching of frees should be suppressed under NOMMU
4781 * The problem is that NOMMU needs to be able to allocate large chunks
4782 * of contiguous memory as there's no hardware page translation to
4783 * assemble apparent contiguous memory from discontiguous pages.
4785 * Queueing large contiguous runs of pages for batching, however,
4786 * causes the pages to actually be freed in smaller chunks. As there
4787 * can be a significant delay between the individual batches being
4788 * recycled, this leads to the once large chunks of space being
4789 * fragmented and becoming unavailable for high-order allocations.
4796 * pcp->high and pcp->batch values are related and dependent on one another:
4797 * ->batch must never be higher then ->high.
4798 * The following function updates them in a safe manner without read side
4801 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4802 * those fields changing asynchronously (acording the the above rule).
4804 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4805 * outside of boot time (or some other assurance that no concurrent updaters
4808 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4809 unsigned long batch)
4811 /* start with a fail safe value for batch */
4815 /* Update high, then batch, in order */
4822 /* a companion to pageset_set_high() */
4823 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4825 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4828 static void pageset_init(struct per_cpu_pageset *p)
4830 struct per_cpu_pages *pcp;
4833 memset(p, 0, sizeof(*p));
4837 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4838 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4841 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4844 pageset_set_batch(p, batch);
4848 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4849 * to the value high for the pageset p.
4851 static void pageset_set_high(struct per_cpu_pageset *p,
4854 unsigned long batch = max(1UL, high / 4);
4855 if ((high / 4) > (PAGE_SHIFT * 8))
4856 batch = PAGE_SHIFT * 8;
4858 pageset_update(&p->pcp, high, batch);
4861 static void pageset_set_high_and_batch(struct zone *zone,
4862 struct per_cpu_pageset *pcp)
4864 if (percpu_pagelist_fraction)
4865 pageset_set_high(pcp,
4866 (zone->managed_pages /
4867 percpu_pagelist_fraction));
4869 pageset_set_batch(pcp, zone_batchsize(zone));
4872 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4874 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4877 pageset_set_high_and_batch(zone, pcp);
4880 static void __meminit setup_zone_pageset(struct zone *zone)
4883 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4884 for_each_possible_cpu(cpu)
4885 zone_pageset_init(zone, cpu);
4889 * Allocate per cpu pagesets and initialize them.
4890 * Before this call only boot pagesets were available.
4892 void __init setup_per_cpu_pageset(void)
4896 for_each_populated_zone(zone)
4897 setup_zone_pageset(zone);
4900 static noinline __init_refok
4901 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4907 * The per-page waitqueue mechanism uses hashed waitqueues
4910 zone->wait_table_hash_nr_entries =
4911 wait_table_hash_nr_entries(zone_size_pages);
4912 zone->wait_table_bits =
4913 wait_table_bits(zone->wait_table_hash_nr_entries);
4914 alloc_size = zone->wait_table_hash_nr_entries
4915 * sizeof(wait_queue_head_t);
4917 if (!slab_is_available()) {
4918 zone->wait_table = (wait_queue_head_t *)
4919 memblock_virt_alloc_node_nopanic(
4920 alloc_size, zone->zone_pgdat->node_id);
4923 * This case means that a zone whose size was 0 gets new memory
4924 * via memory hot-add.
4925 * But it may be the case that a new node was hot-added. In
4926 * this case vmalloc() will not be able to use this new node's
4927 * memory - this wait_table must be initialized to use this new
4928 * node itself as well.
4929 * To use this new node's memory, further consideration will be
4932 zone->wait_table = vmalloc(alloc_size);
4934 if (!zone->wait_table)
4937 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4938 init_waitqueue_head(zone->wait_table + i);
4943 static __meminit void zone_pcp_init(struct zone *zone)
4946 * per cpu subsystem is not up at this point. The following code
4947 * relies on the ability of the linker to provide the
4948 * offset of a (static) per cpu variable into the per cpu area.
4950 zone->pageset = &boot_pageset;
4952 if (populated_zone(zone))
4953 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4954 zone->name, zone->present_pages,
4955 zone_batchsize(zone));
4958 int __meminit init_currently_empty_zone(struct zone *zone,
4959 unsigned long zone_start_pfn,
4962 struct pglist_data *pgdat = zone->zone_pgdat;
4964 ret = zone_wait_table_init(zone, size);
4967 pgdat->nr_zones = zone_idx(zone) + 1;
4969 zone->zone_start_pfn = zone_start_pfn;
4971 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4972 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4974 (unsigned long)zone_idx(zone),
4975 zone_start_pfn, (zone_start_pfn + size));
4977 zone_init_free_lists(zone);
4982 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4983 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4986 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4988 int __meminit __early_pfn_to_nid(unsigned long pfn,
4989 struct mminit_pfnnid_cache *state)
4991 unsigned long start_pfn, end_pfn;
4994 if (state->last_start <= pfn && pfn < state->last_end)
4995 return state->last_nid;
4997 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4999 state->last_start = start_pfn;
5000 state->last_end = end_pfn;
5001 state->last_nid = nid;
5006 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5009 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5010 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5011 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5013 * If an architecture guarantees that all ranges registered contain no holes
5014 * and may be freed, this this function may be used instead of calling
5015 * memblock_free_early_nid() manually.
5017 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5019 unsigned long start_pfn, end_pfn;
5022 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5023 start_pfn = min(start_pfn, max_low_pfn);
5024 end_pfn = min(end_pfn, max_low_pfn);
5026 if (start_pfn < end_pfn)
5027 memblock_free_early_nid(PFN_PHYS(start_pfn),
5028 (end_pfn - start_pfn) << PAGE_SHIFT,
5034 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5035 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5037 * If an architecture guarantees that all ranges registered contain no holes and may
5038 * be freed, this function may be used instead of calling memory_present() manually.
5040 void __init sparse_memory_present_with_active_regions(int nid)
5042 unsigned long start_pfn, end_pfn;
5045 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5046 memory_present(this_nid, start_pfn, end_pfn);
5050 * get_pfn_range_for_nid - Return the start and end page frames for a node
5051 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5052 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5053 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5055 * It returns the start and end page frame of a node based on information
5056 * provided by memblock_set_node(). If called for a node
5057 * with no available memory, a warning is printed and the start and end
5060 void __meminit get_pfn_range_for_nid(unsigned int nid,
5061 unsigned long *start_pfn, unsigned long *end_pfn)
5063 unsigned long this_start_pfn, this_end_pfn;
5069 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5070 *start_pfn = min(*start_pfn, this_start_pfn);
5071 *end_pfn = max(*end_pfn, this_end_pfn);
5074 if (*start_pfn == -1UL)
5079 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5080 * assumption is made that zones within a node are ordered in monotonic
5081 * increasing memory addresses so that the "highest" populated zone is used
5083 static void __init find_usable_zone_for_movable(void)
5086 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5087 if (zone_index == ZONE_MOVABLE)
5090 if (arch_zone_highest_possible_pfn[zone_index] >
5091 arch_zone_lowest_possible_pfn[zone_index])
5095 VM_BUG_ON(zone_index == -1);
5096 movable_zone = zone_index;
5100 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5101 * because it is sized independent of architecture. Unlike the other zones,
5102 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5103 * in each node depending on the size of each node and how evenly kernelcore
5104 * is distributed. This helper function adjusts the zone ranges
5105 * provided by the architecture for a given node by using the end of the
5106 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5107 * zones within a node are in order of monotonic increases memory addresses
5109 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5110 unsigned long zone_type,
5111 unsigned long node_start_pfn,
5112 unsigned long node_end_pfn,
5113 unsigned long *zone_start_pfn,
5114 unsigned long *zone_end_pfn)
5116 /* Only adjust if ZONE_MOVABLE is on this node */
5117 if (zone_movable_pfn[nid]) {
5118 /* Size ZONE_MOVABLE */
5119 if (zone_type == ZONE_MOVABLE) {
5120 *zone_start_pfn = zone_movable_pfn[nid];
5121 *zone_end_pfn = min(node_end_pfn,
5122 arch_zone_highest_possible_pfn[movable_zone]);
5124 /* Check if this whole range is within ZONE_MOVABLE */
5125 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5126 *zone_start_pfn = *zone_end_pfn;
5131 * Return the number of pages a zone spans in a node, including holes
5132 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5134 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5135 unsigned long zone_type,
5136 unsigned long node_start_pfn,
5137 unsigned long node_end_pfn,
5138 unsigned long *zone_start_pfn,
5139 unsigned long *zone_end_pfn,
5140 unsigned long *ignored)
5142 /* When hotadd a new node from cpu_up(), the node should be empty */
5143 if (!node_start_pfn && !node_end_pfn)
5146 /* Get the start and end of the zone */
5147 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5148 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5149 adjust_zone_range_for_zone_movable(nid, zone_type,
5150 node_start_pfn, node_end_pfn,
5151 zone_start_pfn, zone_end_pfn);
5153 /* Check that this node has pages within the zone's required range */
5154 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5157 /* Move the zone boundaries inside the node if necessary */
5158 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5159 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5161 /* Return the spanned pages */
5162 return *zone_end_pfn - *zone_start_pfn;
5166 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5167 * then all holes in the requested range will be accounted for.
5169 unsigned long __meminit __absent_pages_in_range(int nid,
5170 unsigned long range_start_pfn,
5171 unsigned long range_end_pfn)
5173 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5174 unsigned long start_pfn, end_pfn;
5177 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5178 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5179 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5180 nr_absent -= end_pfn - start_pfn;
5186 * absent_pages_in_range - Return number of page frames in holes within a range
5187 * @start_pfn: The start PFN to start searching for holes
5188 * @end_pfn: The end PFN to stop searching for holes
5190 * It returns the number of pages frames in memory holes within a range.
5192 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5193 unsigned long end_pfn)
5195 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5198 /* Return the number of page frames in holes in a zone on a node */
5199 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5200 unsigned long zone_type,
5201 unsigned long node_start_pfn,
5202 unsigned long node_end_pfn,
5203 unsigned long *ignored)
5205 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5206 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5207 unsigned long zone_start_pfn, zone_end_pfn;
5208 unsigned long nr_absent;
5210 /* When hotadd a new node from cpu_up(), the node should be empty */
5211 if (!node_start_pfn && !node_end_pfn)
5214 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5215 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5217 adjust_zone_range_for_zone_movable(nid, zone_type,
5218 node_start_pfn, node_end_pfn,
5219 &zone_start_pfn, &zone_end_pfn);
5220 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5223 * ZONE_MOVABLE handling.
5224 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5227 if (zone_movable_pfn[nid]) {
5228 if (mirrored_kernelcore) {
5229 unsigned long start_pfn, end_pfn;
5230 struct memblock_region *r;
5232 for_each_memblock(memory, r) {
5233 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5234 zone_start_pfn, zone_end_pfn);
5235 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5236 zone_start_pfn, zone_end_pfn);
5238 if (zone_type == ZONE_MOVABLE &&
5239 memblock_is_mirror(r))
5240 nr_absent += end_pfn - start_pfn;
5242 if (zone_type == ZONE_NORMAL &&
5243 !memblock_is_mirror(r))
5244 nr_absent += end_pfn - start_pfn;
5247 if (zone_type == ZONE_NORMAL)
5248 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5255 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5256 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5257 unsigned long zone_type,
5258 unsigned long node_start_pfn,
5259 unsigned long node_end_pfn,
5260 unsigned long *zone_start_pfn,
5261 unsigned long *zone_end_pfn,
5262 unsigned long *zones_size)
5266 *zone_start_pfn = node_start_pfn;
5267 for (zone = 0; zone < zone_type; zone++)
5268 *zone_start_pfn += zones_size[zone];
5270 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5272 return zones_size[zone_type];
5275 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5276 unsigned long zone_type,
5277 unsigned long node_start_pfn,
5278 unsigned long node_end_pfn,
5279 unsigned long *zholes_size)
5284 return zholes_size[zone_type];
5287 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5289 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5290 unsigned long node_start_pfn,
5291 unsigned long node_end_pfn,
5292 unsigned long *zones_size,
5293 unsigned long *zholes_size)
5295 unsigned long realtotalpages = 0, totalpages = 0;
5298 for (i = 0; i < MAX_NR_ZONES; i++) {
5299 struct zone *zone = pgdat->node_zones + i;
5300 unsigned long zone_start_pfn, zone_end_pfn;
5301 unsigned long size, real_size;
5303 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5309 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5310 node_start_pfn, node_end_pfn,
5313 zone->zone_start_pfn = zone_start_pfn;
5315 zone->zone_start_pfn = 0;
5316 zone->spanned_pages = size;
5317 zone->present_pages = real_size;
5320 realtotalpages += real_size;
5323 pgdat->node_spanned_pages = totalpages;
5324 pgdat->node_present_pages = realtotalpages;
5325 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5329 #ifndef CONFIG_SPARSEMEM
5331 * Calculate the size of the zone->blockflags rounded to an unsigned long
5332 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5333 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5334 * round what is now in bits to nearest long in bits, then return it in
5337 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5339 unsigned long usemapsize;
5341 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5342 usemapsize = roundup(zonesize, pageblock_nr_pages);
5343 usemapsize = usemapsize >> pageblock_order;
5344 usemapsize *= NR_PAGEBLOCK_BITS;
5345 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5347 return usemapsize / 8;
5350 static void __init setup_usemap(struct pglist_data *pgdat,
5352 unsigned long zone_start_pfn,
5353 unsigned long zonesize)
5355 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5356 zone->pageblock_flags = NULL;
5358 zone->pageblock_flags =
5359 memblock_virt_alloc_node_nopanic(usemapsize,
5363 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5364 unsigned long zone_start_pfn, unsigned long zonesize) {}
5365 #endif /* CONFIG_SPARSEMEM */
5367 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5369 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5370 void __paginginit set_pageblock_order(void)
5374 /* Check that pageblock_nr_pages has not already been setup */
5375 if (pageblock_order)
5378 if (HPAGE_SHIFT > PAGE_SHIFT)
5379 order = HUGETLB_PAGE_ORDER;
5381 order = MAX_ORDER - 1;
5384 * Assume the largest contiguous order of interest is a huge page.
5385 * This value may be variable depending on boot parameters on IA64 and
5388 pageblock_order = order;
5390 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5393 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5394 * is unused as pageblock_order is set at compile-time. See
5395 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5398 void __paginginit set_pageblock_order(void)
5402 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5404 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5405 unsigned long present_pages)
5407 unsigned long pages = spanned_pages;
5410 * Provide a more accurate estimation if there are holes within
5411 * the zone and SPARSEMEM is in use. If there are holes within the
5412 * zone, each populated memory region may cost us one or two extra
5413 * memmap pages due to alignment because memmap pages for each
5414 * populated regions may not naturally algined on page boundary.
5415 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5417 if (spanned_pages > present_pages + (present_pages >> 4) &&
5418 IS_ENABLED(CONFIG_SPARSEMEM))
5419 pages = present_pages;
5421 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5425 * Set up the zone data structures:
5426 * - mark all pages reserved
5427 * - mark all memory queues empty
5428 * - clear the memory bitmaps
5430 * NOTE: pgdat should get zeroed by caller.
5432 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5435 int nid = pgdat->node_id;
5438 pgdat_resize_init(pgdat);
5439 #ifdef CONFIG_NUMA_BALANCING
5440 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5441 pgdat->numabalancing_migrate_nr_pages = 0;
5442 pgdat->numabalancing_migrate_next_window = jiffies;
5444 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5445 spin_lock_init(&pgdat->split_queue_lock);
5446 INIT_LIST_HEAD(&pgdat->split_queue);
5447 pgdat->split_queue_len = 0;
5449 init_waitqueue_head(&pgdat->kswapd_wait);
5450 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5451 #ifdef CONFIG_COMPACTION
5452 init_waitqueue_head(&pgdat->kcompactd_wait);
5454 pgdat_page_ext_init(pgdat);
5456 for (j = 0; j < MAX_NR_ZONES; j++) {
5457 struct zone *zone = pgdat->node_zones + j;
5458 unsigned long size, realsize, freesize, memmap_pages;
5459 unsigned long zone_start_pfn = zone->zone_start_pfn;
5461 size = zone->spanned_pages;
5462 realsize = freesize = zone->present_pages;
5465 * Adjust freesize so that it accounts for how much memory
5466 * is used by this zone for memmap. This affects the watermark
5467 * and per-cpu initialisations
5469 memmap_pages = calc_memmap_size(size, realsize);
5470 if (!is_highmem_idx(j)) {
5471 if (freesize >= memmap_pages) {
5472 freesize -= memmap_pages;
5475 " %s zone: %lu pages used for memmap\n",
5476 zone_names[j], memmap_pages);
5479 " %s zone: %lu pages exceeds freesize %lu\n",
5480 zone_names[j], memmap_pages, freesize);
5483 /* Account for reserved pages */
5484 if (j == 0 && freesize > dma_reserve) {
5485 freesize -= dma_reserve;
5486 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5487 zone_names[0], dma_reserve);
5490 if (!is_highmem_idx(j))
5491 nr_kernel_pages += freesize;
5492 /* Charge for highmem memmap if there are enough kernel pages */
5493 else if (nr_kernel_pages > memmap_pages * 2)
5494 nr_kernel_pages -= memmap_pages;
5495 nr_all_pages += freesize;
5498 * Set an approximate value for lowmem here, it will be adjusted
5499 * when the bootmem allocator frees pages into the buddy system.
5500 * And all highmem pages will be managed by the buddy system.
5502 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5505 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5507 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5509 zone->name = zone_names[j];
5510 spin_lock_init(&zone->lock);
5511 spin_lock_init(&zone->lru_lock);
5512 zone_seqlock_init(zone);
5513 zone->zone_pgdat = pgdat;
5514 zone_pcp_init(zone);
5516 /* For bootup, initialized properly in watermark setup */
5517 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5519 lruvec_init(&zone->lruvec);
5523 set_pageblock_order();
5524 setup_usemap(pgdat, zone, zone_start_pfn, size);
5525 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5527 memmap_init(size, nid, j, zone_start_pfn);
5531 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5533 unsigned long __maybe_unused start = 0;
5534 unsigned long __maybe_unused offset = 0;
5536 /* Skip empty nodes */
5537 if (!pgdat->node_spanned_pages)
5540 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5541 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5542 offset = pgdat->node_start_pfn - start;
5543 /* ia64 gets its own node_mem_map, before this, without bootmem */
5544 if (!pgdat->node_mem_map) {
5545 unsigned long size, end;
5549 * The zone's endpoints aren't required to be MAX_ORDER
5550 * aligned but the node_mem_map endpoints must be in order
5551 * for the buddy allocator to function correctly.
5553 end = pgdat_end_pfn(pgdat);
5554 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5555 size = (end - start) * sizeof(struct page);
5556 map = alloc_remap(pgdat->node_id, size);
5558 map = memblock_virt_alloc_node_nopanic(size,
5560 pgdat->node_mem_map = map + offset;
5562 #ifndef CONFIG_NEED_MULTIPLE_NODES
5564 * With no DISCONTIG, the global mem_map is just set as node 0's
5566 if (pgdat == NODE_DATA(0)) {
5567 mem_map = NODE_DATA(0)->node_mem_map;
5568 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5569 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5571 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5574 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5577 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5578 unsigned long node_start_pfn, unsigned long *zholes_size)
5580 pg_data_t *pgdat = NODE_DATA(nid);
5581 unsigned long start_pfn = 0;
5582 unsigned long end_pfn = 0;
5584 /* pg_data_t should be reset to zero when it's allocated */
5585 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5587 reset_deferred_meminit(pgdat);
5588 pgdat->node_id = nid;
5589 pgdat->node_start_pfn = node_start_pfn;
5590 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5591 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5592 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5593 (u64)start_pfn << PAGE_SHIFT,
5594 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5596 start_pfn = node_start_pfn;
5598 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5599 zones_size, zholes_size);
5601 alloc_node_mem_map(pgdat);
5602 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5603 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5604 nid, (unsigned long)pgdat,
5605 (unsigned long)pgdat->node_mem_map);
5608 free_area_init_core(pgdat);
5611 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5613 #if MAX_NUMNODES > 1
5615 * Figure out the number of possible node ids.
5617 void __init setup_nr_node_ids(void)
5619 unsigned int highest;
5621 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5622 nr_node_ids = highest + 1;
5627 * node_map_pfn_alignment - determine the maximum internode alignment
5629 * This function should be called after node map is populated and sorted.
5630 * It calculates the maximum power of two alignment which can distinguish
5633 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5634 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5635 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5636 * shifted, 1GiB is enough and this function will indicate so.
5638 * This is used to test whether pfn -> nid mapping of the chosen memory
5639 * model has fine enough granularity to avoid incorrect mapping for the
5640 * populated node map.
5642 * Returns the determined alignment in pfn's. 0 if there is no alignment
5643 * requirement (single node).
5645 unsigned long __init node_map_pfn_alignment(void)
5647 unsigned long accl_mask = 0, last_end = 0;
5648 unsigned long start, end, mask;
5652 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5653 if (!start || last_nid < 0 || last_nid == nid) {
5660 * Start with a mask granular enough to pin-point to the
5661 * start pfn and tick off bits one-by-one until it becomes
5662 * too coarse to separate the current node from the last.
5664 mask = ~((1 << __ffs(start)) - 1);
5665 while (mask && last_end <= (start & (mask << 1)))
5668 /* accumulate all internode masks */
5672 /* convert mask to number of pages */
5673 return ~accl_mask + 1;
5676 /* Find the lowest pfn for a node */
5677 static unsigned long __init find_min_pfn_for_node(int nid)
5679 unsigned long min_pfn = ULONG_MAX;
5680 unsigned long start_pfn;
5683 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5684 min_pfn = min(min_pfn, start_pfn);
5686 if (min_pfn == ULONG_MAX) {
5688 "Could not find start_pfn for node %d\n", nid);
5696 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5698 * It returns the minimum PFN based on information provided via
5699 * memblock_set_node().
5701 unsigned long __init find_min_pfn_with_active_regions(void)
5703 return find_min_pfn_for_node(MAX_NUMNODES);
5707 * early_calculate_totalpages()
5708 * Sum pages in active regions for movable zone.
5709 * Populate N_MEMORY for calculating usable_nodes.
5711 static unsigned long __init early_calculate_totalpages(void)
5713 unsigned long totalpages = 0;
5714 unsigned long start_pfn, end_pfn;
5717 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5718 unsigned long pages = end_pfn - start_pfn;
5720 totalpages += pages;
5722 node_set_state(nid, N_MEMORY);
5728 * Find the PFN the Movable zone begins in each node. Kernel memory
5729 * is spread evenly between nodes as long as the nodes have enough
5730 * memory. When they don't, some nodes will have more kernelcore than
5733 static void __init find_zone_movable_pfns_for_nodes(void)
5736 unsigned long usable_startpfn;
5737 unsigned long kernelcore_node, kernelcore_remaining;
5738 /* save the state before borrow the nodemask */
5739 nodemask_t saved_node_state = node_states[N_MEMORY];
5740 unsigned long totalpages = early_calculate_totalpages();
5741 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5742 struct memblock_region *r;
5744 /* Need to find movable_zone earlier when movable_node is specified. */
5745 find_usable_zone_for_movable();
5748 * If movable_node is specified, ignore kernelcore and movablecore
5751 if (movable_node_is_enabled()) {
5752 for_each_memblock(memory, r) {
5753 if (!memblock_is_hotpluggable(r))
5758 usable_startpfn = PFN_DOWN(r->base);
5759 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5760 min(usable_startpfn, zone_movable_pfn[nid]) :
5768 * If kernelcore=mirror is specified, ignore movablecore option
5770 if (mirrored_kernelcore) {
5771 bool mem_below_4gb_not_mirrored = false;
5773 for_each_memblock(memory, r) {
5774 if (memblock_is_mirror(r))
5779 usable_startpfn = memblock_region_memory_base_pfn(r);
5781 if (usable_startpfn < 0x100000) {
5782 mem_below_4gb_not_mirrored = true;
5786 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5787 min(usable_startpfn, zone_movable_pfn[nid]) :
5791 if (mem_below_4gb_not_mirrored)
5792 pr_warn("This configuration results in unmirrored kernel memory.");
5798 * If movablecore=nn[KMG] was specified, calculate what size of
5799 * kernelcore that corresponds so that memory usable for
5800 * any allocation type is evenly spread. If both kernelcore
5801 * and movablecore are specified, then the value of kernelcore
5802 * will be used for required_kernelcore if it's greater than
5803 * what movablecore would have allowed.
5805 if (required_movablecore) {
5806 unsigned long corepages;
5809 * Round-up so that ZONE_MOVABLE is at least as large as what
5810 * was requested by the user
5812 required_movablecore =
5813 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5814 required_movablecore = min(totalpages, required_movablecore);
5815 corepages = totalpages - required_movablecore;
5817 required_kernelcore = max(required_kernelcore, corepages);
5821 * If kernelcore was not specified or kernelcore size is larger
5822 * than totalpages, there is no ZONE_MOVABLE.
5824 if (!required_kernelcore || required_kernelcore >= totalpages)
5827 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5828 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5831 /* Spread kernelcore memory as evenly as possible throughout nodes */
5832 kernelcore_node = required_kernelcore / usable_nodes;
5833 for_each_node_state(nid, N_MEMORY) {
5834 unsigned long start_pfn, end_pfn;
5837 * Recalculate kernelcore_node if the division per node
5838 * now exceeds what is necessary to satisfy the requested
5839 * amount of memory for the kernel
5841 if (required_kernelcore < kernelcore_node)
5842 kernelcore_node = required_kernelcore / usable_nodes;
5845 * As the map is walked, we track how much memory is usable
5846 * by the kernel using kernelcore_remaining. When it is
5847 * 0, the rest of the node is usable by ZONE_MOVABLE
5849 kernelcore_remaining = kernelcore_node;
5851 /* Go through each range of PFNs within this node */
5852 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5853 unsigned long size_pages;
5855 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5856 if (start_pfn >= end_pfn)
5859 /* Account for what is only usable for kernelcore */
5860 if (start_pfn < usable_startpfn) {
5861 unsigned long kernel_pages;
5862 kernel_pages = min(end_pfn, usable_startpfn)
5865 kernelcore_remaining -= min(kernel_pages,
5866 kernelcore_remaining);
5867 required_kernelcore -= min(kernel_pages,
5868 required_kernelcore);
5870 /* Continue if range is now fully accounted */
5871 if (end_pfn <= usable_startpfn) {
5874 * Push zone_movable_pfn to the end so
5875 * that if we have to rebalance
5876 * kernelcore across nodes, we will
5877 * not double account here
5879 zone_movable_pfn[nid] = end_pfn;
5882 start_pfn = usable_startpfn;
5886 * The usable PFN range for ZONE_MOVABLE is from
5887 * start_pfn->end_pfn. Calculate size_pages as the
5888 * number of pages used as kernelcore
5890 size_pages = end_pfn - start_pfn;
5891 if (size_pages > kernelcore_remaining)
5892 size_pages = kernelcore_remaining;
5893 zone_movable_pfn[nid] = start_pfn + size_pages;
5896 * Some kernelcore has been met, update counts and
5897 * break if the kernelcore for this node has been
5900 required_kernelcore -= min(required_kernelcore,
5902 kernelcore_remaining -= size_pages;
5903 if (!kernelcore_remaining)
5909 * If there is still required_kernelcore, we do another pass with one
5910 * less node in the count. This will push zone_movable_pfn[nid] further
5911 * along on the nodes that still have memory until kernelcore is
5915 if (usable_nodes && required_kernelcore > usable_nodes)
5919 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5920 for (nid = 0; nid < MAX_NUMNODES; nid++)
5921 zone_movable_pfn[nid] =
5922 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5925 /* restore the node_state */
5926 node_states[N_MEMORY] = saved_node_state;
5929 /* Any regular or high memory on that node ? */
5930 static void check_for_memory(pg_data_t *pgdat, int nid)
5932 enum zone_type zone_type;
5934 if (N_MEMORY == N_NORMAL_MEMORY)
5937 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5938 struct zone *zone = &pgdat->node_zones[zone_type];
5939 if (populated_zone(zone)) {
5940 node_set_state(nid, N_HIGH_MEMORY);
5941 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5942 zone_type <= ZONE_NORMAL)
5943 node_set_state(nid, N_NORMAL_MEMORY);
5950 * free_area_init_nodes - Initialise all pg_data_t and zone data
5951 * @max_zone_pfn: an array of max PFNs for each zone
5953 * This will call free_area_init_node() for each active node in the system.
5954 * Using the page ranges provided by memblock_set_node(), the size of each
5955 * zone in each node and their holes is calculated. If the maximum PFN
5956 * between two adjacent zones match, it is assumed that the zone is empty.
5957 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5958 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5959 * starts where the previous one ended. For example, ZONE_DMA32 starts
5960 * at arch_max_dma_pfn.
5962 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5964 unsigned long start_pfn, end_pfn;
5967 /* Record where the zone boundaries are */
5968 memset(arch_zone_lowest_possible_pfn, 0,
5969 sizeof(arch_zone_lowest_possible_pfn));
5970 memset(arch_zone_highest_possible_pfn, 0,
5971 sizeof(arch_zone_highest_possible_pfn));
5972 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5973 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5974 for (i = 1; i < MAX_NR_ZONES; i++) {
5975 if (i == ZONE_MOVABLE)
5977 arch_zone_lowest_possible_pfn[i] =
5978 arch_zone_highest_possible_pfn[i-1];
5979 arch_zone_highest_possible_pfn[i] =
5980 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5982 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5983 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5985 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5986 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5987 find_zone_movable_pfns_for_nodes();
5989 /* Print out the zone ranges */
5990 pr_info("Zone ranges:\n");
5991 for (i = 0; i < MAX_NR_ZONES; i++) {
5992 if (i == ZONE_MOVABLE)
5994 pr_info(" %-8s ", zone_names[i]);
5995 if (arch_zone_lowest_possible_pfn[i] ==
5996 arch_zone_highest_possible_pfn[i])
5999 pr_cont("[mem %#018Lx-%#018Lx]\n",
6000 (u64)arch_zone_lowest_possible_pfn[i]
6002 ((u64)arch_zone_highest_possible_pfn[i]
6003 << PAGE_SHIFT) - 1);
6006 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6007 pr_info("Movable zone start for each node\n");
6008 for (i = 0; i < MAX_NUMNODES; i++) {
6009 if (zone_movable_pfn[i])
6010 pr_info(" Node %d: %#018Lx\n", i,
6011 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6014 /* Print out the early node map */
6015 pr_info("Early memory node ranges\n");
6016 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6017 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6018 (u64)start_pfn << PAGE_SHIFT,
6019 ((u64)end_pfn << PAGE_SHIFT) - 1);
6021 /* Initialise every node */
6022 mminit_verify_pageflags_layout();
6023 setup_nr_node_ids();
6024 for_each_online_node(nid) {
6025 pg_data_t *pgdat = NODE_DATA(nid);
6026 free_area_init_node(nid, NULL,
6027 find_min_pfn_for_node(nid), NULL);
6029 /* Any memory on that node */
6030 if (pgdat->node_present_pages)
6031 node_set_state(nid, N_MEMORY);
6032 check_for_memory(pgdat, nid);
6036 static int __init cmdline_parse_core(char *p, unsigned long *core)
6038 unsigned long long coremem;
6042 coremem = memparse(p, &p);
6043 *core = coremem >> PAGE_SHIFT;
6045 /* Paranoid check that UL is enough for the coremem value */
6046 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6052 * kernelcore=size sets the amount of memory for use for allocations that
6053 * cannot be reclaimed or migrated.
6055 static int __init cmdline_parse_kernelcore(char *p)
6057 /* parse kernelcore=mirror */
6058 if (parse_option_str(p, "mirror")) {
6059 mirrored_kernelcore = true;
6063 return cmdline_parse_core(p, &required_kernelcore);
6067 * movablecore=size sets the amount of memory for use for allocations that
6068 * can be reclaimed or migrated.
6070 static int __init cmdline_parse_movablecore(char *p)
6072 return cmdline_parse_core(p, &required_movablecore);
6075 early_param("kernelcore", cmdline_parse_kernelcore);
6076 early_param("movablecore", cmdline_parse_movablecore);
6078 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6080 void adjust_managed_page_count(struct page *page, long count)
6082 spin_lock(&managed_page_count_lock);
6083 page_zone(page)->managed_pages += count;
6084 totalram_pages += count;
6085 #ifdef CONFIG_HIGHMEM
6086 if (PageHighMem(page))
6087 totalhigh_pages += count;
6089 spin_unlock(&managed_page_count_lock);
6091 EXPORT_SYMBOL(adjust_managed_page_count);
6093 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6096 unsigned long pages = 0;
6098 start = (void *)PAGE_ALIGN((unsigned long)start);
6099 end = (void *)((unsigned long)end & PAGE_MASK);
6100 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6101 if ((unsigned int)poison <= 0xFF)
6102 memset(pos, poison, PAGE_SIZE);
6103 free_reserved_page(virt_to_page(pos));
6107 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6108 s, pages << (PAGE_SHIFT - 10), start, end);
6112 EXPORT_SYMBOL(free_reserved_area);
6114 #ifdef CONFIG_HIGHMEM
6115 void free_highmem_page(struct page *page)
6117 __free_reserved_page(page);
6119 page_zone(page)->managed_pages++;
6125 void __init mem_init_print_info(const char *str)
6127 unsigned long physpages, codesize, datasize, rosize, bss_size;
6128 unsigned long init_code_size, init_data_size;
6130 physpages = get_num_physpages();
6131 codesize = _etext - _stext;
6132 datasize = _edata - _sdata;
6133 rosize = __end_rodata - __start_rodata;
6134 bss_size = __bss_stop - __bss_start;
6135 init_data_size = __init_end - __init_begin;
6136 init_code_size = _einittext - _sinittext;
6139 * Detect special cases and adjust section sizes accordingly:
6140 * 1) .init.* may be embedded into .data sections
6141 * 2) .init.text.* may be out of [__init_begin, __init_end],
6142 * please refer to arch/tile/kernel/vmlinux.lds.S.
6143 * 3) .rodata.* may be embedded into .text or .data sections.
6145 #define adj_init_size(start, end, size, pos, adj) \
6147 if (start <= pos && pos < end && size > adj) \
6151 adj_init_size(__init_begin, __init_end, init_data_size,
6152 _sinittext, init_code_size);
6153 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6154 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6155 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6156 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6158 #undef adj_init_size
6160 pr_info("Memory: %luK/%luK available "
6161 "(%luK kernel code, %luK rwdata, %luK rodata, "
6162 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
6163 #ifdef CONFIG_HIGHMEM
6167 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
6168 codesize >> 10, datasize >> 10, rosize >> 10,
6169 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6170 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10),
6171 totalcma_pages << (PAGE_SHIFT-10),
6172 #ifdef CONFIG_HIGHMEM
6173 totalhigh_pages << (PAGE_SHIFT-10),
6175 str ? ", " : "", str ? str : "");
6179 * set_dma_reserve - set the specified number of pages reserved in the first zone
6180 * @new_dma_reserve: The number of pages to mark reserved
6182 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6183 * In the DMA zone, a significant percentage may be consumed by kernel image
6184 * and other unfreeable allocations which can skew the watermarks badly. This
6185 * function may optionally be used to account for unfreeable pages in the
6186 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6187 * smaller per-cpu batchsize.
6189 void __init set_dma_reserve(unsigned long new_dma_reserve)
6191 dma_reserve = new_dma_reserve;
6194 void __init free_area_init(unsigned long *zones_size)
6196 free_area_init_node(0, zones_size,
6197 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6200 static int page_alloc_cpu_notify(struct notifier_block *self,
6201 unsigned long action, void *hcpu)
6203 int cpu = (unsigned long)hcpu;
6205 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6206 lru_add_drain_cpu(cpu);
6210 * Spill the event counters of the dead processor
6211 * into the current processors event counters.
6212 * This artificially elevates the count of the current
6215 vm_events_fold_cpu(cpu);
6218 * Zero the differential counters of the dead processor
6219 * so that the vm statistics are consistent.
6221 * This is only okay since the processor is dead and cannot
6222 * race with what we are doing.
6224 cpu_vm_stats_fold(cpu);
6229 void __init page_alloc_init(void)
6231 hotcpu_notifier(page_alloc_cpu_notify, 0);
6235 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6236 * or min_free_kbytes changes.
6238 static void calculate_totalreserve_pages(void)
6240 struct pglist_data *pgdat;
6241 unsigned long reserve_pages = 0;
6242 enum zone_type i, j;
6244 for_each_online_pgdat(pgdat) {
6245 for (i = 0; i < MAX_NR_ZONES; i++) {
6246 struct zone *zone = pgdat->node_zones + i;
6249 /* Find valid and maximum lowmem_reserve in the zone */
6250 for (j = i; j < MAX_NR_ZONES; j++) {
6251 if (zone->lowmem_reserve[j] > max)
6252 max = zone->lowmem_reserve[j];
6255 /* we treat the high watermark as reserved pages. */
6256 max += high_wmark_pages(zone);
6258 if (max > zone->managed_pages)
6259 max = zone->managed_pages;
6261 zone->totalreserve_pages = max;
6263 reserve_pages += max;
6266 totalreserve_pages = reserve_pages;
6270 * setup_per_zone_lowmem_reserve - called whenever
6271 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6272 * has a correct pages reserved value, so an adequate number of
6273 * pages are left in the zone after a successful __alloc_pages().
6275 static void setup_per_zone_lowmem_reserve(void)
6277 struct pglist_data *pgdat;
6278 enum zone_type j, idx;
6280 for_each_online_pgdat(pgdat) {
6281 for (j = 0; j < MAX_NR_ZONES; j++) {
6282 struct zone *zone = pgdat->node_zones + j;
6283 unsigned long managed_pages = zone->managed_pages;
6285 zone->lowmem_reserve[j] = 0;
6289 struct zone *lower_zone;
6293 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6294 sysctl_lowmem_reserve_ratio[idx] = 1;
6296 lower_zone = pgdat->node_zones + idx;
6297 lower_zone->lowmem_reserve[j] = managed_pages /
6298 sysctl_lowmem_reserve_ratio[idx];
6299 managed_pages += lower_zone->managed_pages;
6304 /* update totalreserve_pages */
6305 calculate_totalreserve_pages();
6308 static void __setup_per_zone_wmarks(void)
6310 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6311 unsigned long lowmem_pages = 0;
6313 unsigned long flags;
6315 /* Calculate total number of !ZONE_HIGHMEM pages */
6316 for_each_zone(zone) {
6317 if (!is_highmem(zone))
6318 lowmem_pages += zone->managed_pages;
6321 for_each_zone(zone) {
6324 spin_lock_irqsave(&zone->lock, flags);
6325 tmp = (u64)pages_min * zone->managed_pages;
6326 do_div(tmp, lowmem_pages);
6327 if (is_highmem(zone)) {
6329 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6330 * need highmem pages, so cap pages_min to a small
6333 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6334 * deltas control asynch page reclaim, and so should
6335 * not be capped for highmem.
6337 unsigned long min_pages;
6339 min_pages = zone->managed_pages / 1024;
6340 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6341 zone->watermark[WMARK_MIN] = min_pages;
6344 * If it's a lowmem zone, reserve a number of pages
6345 * proportionate to the zone's size.
6347 zone->watermark[WMARK_MIN] = tmp;
6350 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
6351 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
6353 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6354 high_wmark_pages(zone) - low_wmark_pages(zone) -
6355 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6357 spin_unlock_irqrestore(&zone->lock, flags);
6360 /* update totalreserve_pages */
6361 calculate_totalreserve_pages();
6365 * setup_per_zone_wmarks - called when min_free_kbytes changes
6366 * or when memory is hot-{added|removed}
6368 * Ensures that the watermark[min,low,high] values for each zone are set
6369 * correctly with respect to min_free_kbytes.
6371 void setup_per_zone_wmarks(void)
6373 mutex_lock(&zonelists_mutex);
6374 __setup_per_zone_wmarks();
6375 mutex_unlock(&zonelists_mutex);
6379 * The inactive anon list should be small enough that the VM never has to
6380 * do too much work, but large enough that each inactive page has a chance
6381 * to be referenced again before it is swapped out.
6383 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6384 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6385 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6386 * the anonymous pages are kept on the inactive list.
6389 * memory ratio inactive anon
6390 * -------------------------------------
6399 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6401 unsigned int gb, ratio;
6403 /* Zone size in gigabytes */
6404 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6406 ratio = int_sqrt(10 * gb);
6410 zone->inactive_ratio = ratio;
6413 static void __meminit setup_per_zone_inactive_ratio(void)
6418 calculate_zone_inactive_ratio(zone);
6422 * Initialise min_free_kbytes.
6424 * For small machines we want it small (128k min). For large machines
6425 * we want it large (64MB max). But it is not linear, because network
6426 * bandwidth does not increase linearly with machine size. We use
6428 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6429 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6445 int __meminit init_per_zone_wmark_min(void)
6447 unsigned long lowmem_kbytes;
6448 int new_min_free_kbytes;
6450 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6451 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6453 if (new_min_free_kbytes > user_min_free_kbytes) {
6454 min_free_kbytes = new_min_free_kbytes;
6455 if (min_free_kbytes < 128)
6456 min_free_kbytes = 128;
6457 if (min_free_kbytes > 65536)
6458 min_free_kbytes = 65536;
6460 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6461 new_min_free_kbytes, user_min_free_kbytes);
6463 setup_per_zone_wmarks();
6464 refresh_zone_stat_thresholds();
6465 setup_per_zone_lowmem_reserve();
6466 setup_per_zone_inactive_ratio();
6469 module_init(init_per_zone_wmark_min)
6472 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6473 * that we can call two helper functions whenever min_free_kbytes
6476 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6477 void __user *buffer, size_t *length, loff_t *ppos)
6481 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6486 user_min_free_kbytes = min_free_kbytes;
6487 setup_per_zone_wmarks();
6493 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6494 void __user *buffer, size_t *length, loff_t *ppos)
6499 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6504 zone->min_unmapped_pages = (zone->managed_pages *
6505 sysctl_min_unmapped_ratio) / 100;
6509 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6510 void __user *buffer, size_t *length, loff_t *ppos)
6515 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6520 zone->min_slab_pages = (zone->managed_pages *
6521 sysctl_min_slab_ratio) / 100;
6527 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6528 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6529 * whenever sysctl_lowmem_reserve_ratio changes.
6531 * The reserve ratio obviously has absolutely no relation with the
6532 * minimum watermarks. The lowmem reserve ratio can only make sense
6533 * if in function of the boot time zone sizes.
6535 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6536 void __user *buffer, size_t *length, loff_t *ppos)
6538 proc_dointvec_minmax(table, write, buffer, length, ppos);
6539 setup_per_zone_lowmem_reserve();
6544 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6545 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6546 * pagelist can have before it gets flushed back to buddy allocator.
6548 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6549 void __user *buffer, size_t *length, loff_t *ppos)
6552 int old_percpu_pagelist_fraction;
6555 mutex_lock(&pcp_batch_high_lock);
6556 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6558 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6559 if (!write || ret < 0)
6562 /* Sanity checking to avoid pcp imbalance */
6563 if (percpu_pagelist_fraction &&
6564 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6565 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6571 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6574 for_each_populated_zone(zone) {
6577 for_each_possible_cpu(cpu)
6578 pageset_set_high_and_batch(zone,
6579 per_cpu_ptr(zone->pageset, cpu));
6582 mutex_unlock(&pcp_batch_high_lock);
6587 int hashdist = HASHDIST_DEFAULT;
6589 static int __init set_hashdist(char *str)
6593 hashdist = simple_strtoul(str, &str, 0);
6596 __setup("hashdist=", set_hashdist);
6600 * allocate a large system hash table from bootmem
6601 * - it is assumed that the hash table must contain an exact power-of-2
6602 * quantity of entries
6603 * - limit is the number of hash buckets, not the total allocation size
6605 void *__init alloc_large_system_hash(const char *tablename,
6606 unsigned long bucketsize,
6607 unsigned long numentries,
6610 unsigned int *_hash_shift,
6611 unsigned int *_hash_mask,
6612 unsigned long low_limit,
6613 unsigned long high_limit)
6615 unsigned long long max = high_limit;
6616 unsigned long log2qty, size;
6619 /* allow the kernel cmdline to have a say */
6621 /* round applicable memory size up to nearest megabyte */
6622 numentries = nr_kernel_pages;
6624 /* It isn't necessary when PAGE_SIZE >= 1MB */
6625 if (PAGE_SHIFT < 20)
6626 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6628 /* limit to 1 bucket per 2^scale bytes of low memory */
6629 if (scale > PAGE_SHIFT)
6630 numentries >>= (scale - PAGE_SHIFT);
6632 numentries <<= (PAGE_SHIFT - scale);
6634 /* Make sure we've got at least a 0-order allocation.. */
6635 if (unlikely(flags & HASH_SMALL)) {
6636 /* Makes no sense without HASH_EARLY */
6637 WARN_ON(!(flags & HASH_EARLY));
6638 if (!(numentries >> *_hash_shift)) {
6639 numentries = 1UL << *_hash_shift;
6640 BUG_ON(!numentries);
6642 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6643 numentries = PAGE_SIZE / bucketsize;
6645 numentries = roundup_pow_of_two(numentries);
6647 /* limit allocation size to 1/16 total memory by default */
6649 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6650 do_div(max, bucketsize);
6652 max = min(max, 0x80000000ULL);
6654 if (numentries < low_limit)
6655 numentries = low_limit;
6656 if (numentries > max)
6659 log2qty = ilog2(numentries);
6662 size = bucketsize << log2qty;
6663 if (flags & HASH_EARLY)
6664 table = memblock_virt_alloc_nopanic(size, 0);
6666 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6669 * If bucketsize is not a power-of-two, we may free
6670 * some pages at the end of hash table which
6671 * alloc_pages_exact() automatically does
6673 if (get_order(size) < MAX_ORDER) {
6674 table = alloc_pages_exact(size, GFP_ATOMIC);
6675 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6678 } while (!table && size > PAGE_SIZE && --log2qty);
6681 panic("Failed to allocate %s hash table\n", tablename);
6683 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6686 ilog2(size) - PAGE_SHIFT,
6690 *_hash_shift = log2qty;
6692 *_hash_mask = (1 << log2qty) - 1;
6697 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6698 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6701 #ifdef CONFIG_SPARSEMEM
6702 return __pfn_to_section(pfn)->pageblock_flags;
6704 return zone->pageblock_flags;
6705 #endif /* CONFIG_SPARSEMEM */
6708 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6710 #ifdef CONFIG_SPARSEMEM
6711 pfn &= (PAGES_PER_SECTION-1);
6712 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6714 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6715 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6716 #endif /* CONFIG_SPARSEMEM */
6720 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6721 * @page: The page within the block of interest
6722 * @pfn: The target page frame number
6723 * @end_bitidx: The last bit of interest to retrieve
6724 * @mask: mask of bits that the caller is interested in
6726 * Return: pageblock_bits flags
6728 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6729 unsigned long end_bitidx,
6733 unsigned long *bitmap;
6734 unsigned long bitidx, word_bitidx;
6737 zone = page_zone(page);
6738 bitmap = get_pageblock_bitmap(zone, pfn);
6739 bitidx = pfn_to_bitidx(zone, pfn);
6740 word_bitidx = bitidx / BITS_PER_LONG;
6741 bitidx &= (BITS_PER_LONG-1);
6743 word = bitmap[word_bitidx];
6744 bitidx += end_bitidx;
6745 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6749 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6750 * @page: The page within the block of interest
6751 * @flags: The flags to set
6752 * @pfn: The target page frame number
6753 * @end_bitidx: The last bit of interest
6754 * @mask: mask of bits that the caller is interested in
6756 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6758 unsigned long end_bitidx,
6762 unsigned long *bitmap;
6763 unsigned long bitidx, word_bitidx;
6764 unsigned long old_word, word;
6766 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6768 zone = page_zone(page);
6769 bitmap = get_pageblock_bitmap(zone, pfn);
6770 bitidx = pfn_to_bitidx(zone, pfn);
6771 word_bitidx = bitidx / BITS_PER_LONG;
6772 bitidx &= (BITS_PER_LONG-1);
6774 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6776 bitidx += end_bitidx;
6777 mask <<= (BITS_PER_LONG - bitidx - 1);
6778 flags <<= (BITS_PER_LONG - bitidx - 1);
6780 word = READ_ONCE(bitmap[word_bitidx]);
6782 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6783 if (word == old_word)
6790 * This function checks whether pageblock includes unmovable pages or not.
6791 * If @count is not zero, it is okay to include less @count unmovable pages
6793 * PageLRU check without isolation or lru_lock could race so that
6794 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6795 * expect this function should be exact.
6797 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6798 bool skip_hwpoisoned_pages)
6800 unsigned long pfn, iter, found;
6804 * For avoiding noise data, lru_add_drain_all() should be called
6805 * If ZONE_MOVABLE, the zone never contains unmovable pages
6807 if (zone_idx(zone) == ZONE_MOVABLE)
6809 mt = get_pageblock_migratetype(page);
6810 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6813 pfn = page_to_pfn(page);
6814 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6815 unsigned long check = pfn + iter;
6817 if (!pfn_valid_within(check))
6820 page = pfn_to_page(check);
6823 * Hugepages are not in LRU lists, but they're movable.
6824 * We need not scan over tail pages bacause we don't
6825 * handle each tail page individually in migration.
6827 if (PageHuge(page)) {
6828 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6833 * We can't use page_count without pin a page
6834 * because another CPU can free compound page.
6835 * This check already skips compound tails of THP
6836 * because their page->_count is zero at all time.
6838 if (!atomic_read(&page->_count)) {
6839 if (PageBuddy(page))
6840 iter += (1 << page_order(page)) - 1;
6845 * The HWPoisoned page may be not in buddy system, and
6846 * page_count() is not 0.
6848 if (skip_hwpoisoned_pages && PageHWPoison(page))
6854 * If there are RECLAIMABLE pages, we need to check
6855 * it. But now, memory offline itself doesn't call
6856 * shrink_node_slabs() and it still to be fixed.
6859 * If the page is not RAM, page_count()should be 0.
6860 * we don't need more check. This is an _used_ not-movable page.
6862 * The problematic thing here is PG_reserved pages. PG_reserved
6863 * is set to both of a memory hole page and a _used_ kernel
6872 bool is_pageblock_removable_nolock(struct page *page)
6878 * We have to be careful here because we are iterating over memory
6879 * sections which are not zone aware so we might end up outside of
6880 * the zone but still within the section.
6881 * We have to take care about the node as well. If the node is offline
6882 * its NODE_DATA will be NULL - see page_zone.
6884 if (!node_online(page_to_nid(page)))
6887 zone = page_zone(page);
6888 pfn = page_to_pfn(page);
6889 if (!zone_spans_pfn(zone, pfn))
6892 return !has_unmovable_pages(zone, page, 0, true);
6895 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6897 static unsigned long pfn_max_align_down(unsigned long pfn)
6899 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6900 pageblock_nr_pages) - 1);
6903 static unsigned long pfn_max_align_up(unsigned long pfn)
6905 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6906 pageblock_nr_pages));
6909 /* [start, end) must belong to a single zone. */
6910 static int __alloc_contig_migrate_range(struct compact_control *cc,
6911 unsigned long start, unsigned long end)
6913 /* This function is based on compact_zone() from compaction.c. */
6914 unsigned long nr_reclaimed;
6915 unsigned long pfn = start;
6916 unsigned int tries = 0;
6921 while (pfn < end || !list_empty(&cc->migratepages)) {
6922 if (fatal_signal_pending(current)) {
6927 if (list_empty(&cc->migratepages)) {
6928 cc->nr_migratepages = 0;
6929 pfn = isolate_migratepages_range(cc, pfn, end);
6935 } else if (++tries == 5) {
6936 ret = ret < 0 ? ret : -EBUSY;
6940 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6942 cc->nr_migratepages -= nr_reclaimed;
6944 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6945 NULL, 0, cc->mode, MR_CMA);
6948 putback_movable_pages(&cc->migratepages);
6955 * alloc_contig_range() -- tries to allocate given range of pages
6956 * @start: start PFN to allocate
6957 * @end: one-past-the-last PFN to allocate
6958 * @migratetype: migratetype of the underlaying pageblocks (either
6959 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6960 * in range must have the same migratetype and it must
6961 * be either of the two.
6963 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6964 * aligned, however it's the caller's responsibility to guarantee that
6965 * we are the only thread that changes migrate type of pageblocks the
6968 * The PFN range must belong to a single zone.
6970 * Returns zero on success or negative error code. On success all
6971 * pages which PFN is in [start, end) are allocated for the caller and
6972 * need to be freed with free_contig_range().
6974 int alloc_contig_range(unsigned long start, unsigned long end,
6975 unsigned migratetype)
6977 unsigned long outer_start, outer_end;
6981 struct compact_control cc = {
6982 .nr_migratepages = 0,
6984 .zone = page_zone(pfn_to_page(start)),
6985 .mode = MIGRATE_SYNC,
6986 .ignore_skip_hint = true,
6988 INIT_LIST_HEAD(&cc.migratepages);
6991 * What we do here is we mark all pageblocks in range as
6992 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6993 * have different sizes, and due to the way page allocator
6994 * work, we align the range to biggest of the two pages so
6995 * that page allocator won't try to merge buddies from
6996 * different pageblocks and change MIGRATE_ISOLATE to some
6997 * other migration type.
6999 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7000 * migrate the pages from an unaligned range (ie. pages that
7001 * we are interested in). This will put all the pages in
7002 * range back to page allocator as MIGRATE_ISOLATE.
7004 * When this is done, we take the pages in range from page
7005 * allocator removing them from the buddy system. This way
7006 * page allocator will never consider using them.
7008 * This lets us mark the pageblocks back as
7009 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7010 * aligned range but not in the unaligned, original range are
7011 * put back to page allocator so that buddy can use them.
7014 ret = start_isolate_page_range(pfn_max_align_down(start),
7015 pfn_max_align_up(end), migratetype,
7021 * In case of -EBUSY, we'd like to know which page causes problem.
7022 * So, just fall through. We will check it in test_pages_isolated().
7024 ret = __alloc_contig_migrate_range(&cc, start, end);
7025 if (ret && ret != -EBUSY)
7029 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7030 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7031 * more, all pages in [start, end) are free in page allocator.
7032 * What we are going to do is to allocate all pages from
7033 * [start, end) (that is remove them from page allocator).
7035 * The only problem is that pages at the beginning and at the
7036 * end of interesting range may be not aligned with pages that
7037 * page allocator holds, ie. they can be part of higher order
7038 * pages. Because of this, we reserve the bigger range and
7039 * once this is done free the pages we are not interested in.
7041 * We don't have to hold zone->lock here because the pages are
7042 * isolated thus they won't get removed from buddy.
7045 lru_add_drain_all();
7046 drain_all_pages(cc.zone);
7049 outer_start = start;
7050 while (!PageBuddy(pfn_to_page(outer_start))) {
7051 if (++order >= MAX_ORDER) {
7052 outer_start = start;
7055 outer_start &= ~0UL << order;
7058 if (outer_start != start) {
7059 order = page_order(pfn_to_page(outer_start));
7062 * outer_start page could be small order buddy page and
7063 * it doesn't include start page. Adjust outer_start
7064 * in this case to report failed page properly
7065 * on tracepoint in test_pages_isolated()
7067 if (outer_start + (1UL << order) <= start)
7068 outer_start = start;
7071 /* Make sure the range is really isolated. */
7072 if (test_pages_isolated(outer_start, end, false)) {
7073 pr_info("%s: [%lx, %lx) PFNs busy\n",
7074 __func__, outer_start, end);
7079 /* Grab isolated pages from freelists. */
7080 outer_end = isolate_freepages_range(&cc, outer_start, end);
7086 /* Free head and tail (if any) */
7087 if (start != outer_start)
7088 free_contig_range(outer_start, start - outer_start);
7089 if (end != outer_end)
7090 free_contig_range(end, outer_end - end);
7093 undo_isolate_page_range(pfn_max_align_down(start),
7094 pfn_max_align_up(end), migratetype);
7098 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7100 unsigned int count = 0;
7102 for (; nr_pages--; pfn++) {
7103 struct page *page = pfn_to_page(pfn);
7105 count += page_count(page) != 1;
7108 WARN(count != 0, "%d pages are still in use!\n", count);
7112 #ifdef CONFIG_MEMORY_HOTPLUG
7114 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7115 * page high values need to be recalulated.
7117 void __meminit zone_pcp_update(struct zone *zone)
7120 mutex_lock(&pcp_batch_high_lock);
7121 for_each_possible_cpu(cpu)
7122 pageset_set_high_and_batch(zone,
7123 per_cpu_ptr(zone->pageset, cpu));
7124 mutex_unlock(&pcp_batch_high_lock);
7128 void zone_pcp_reset(struct zone *zone)
7130 unsigned long flags;
7132 struct per_cpu_pageset *pset;
7134 /* avoid races with drain_pages() */
7135 local_irq_save(flags);
7136 if (zone->pageset != &boot_pageset) {
7137 for_each_online_cpu(cpu) {
7138 pset = per_cpu_ptr(zone->pageset, cpu);
7139 drain_zonestat(zone, pset);
7141 free_percpu(zone->pageset);
7142 zone->pageset = &boot_pageset;
7144 local_irq_restore(flags);
7147 #ifdef CONFIG_MEMORY_HOTREMOVE
7149 * All pages in the range must be isolated before calling this.
7152 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7156 unsigned int order, i;
7158 unsigned long flags;
7159 /* find the first valid pfn */
7160 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7165 zone = page_zone(pfn_to_page(pfn));
7166 spin_lock_irqsave(&zone->lock, flags);
7168 while (pfn < end_pfn) {
7169 if (!pfn_valid(pfn)) {
7173 page = pfn_to_page(pfn);
7175 * The HWPoisoned page may be not in buddy system, and
7176 * page_count() is not 0.
7178 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7180 SetPageReserved(page);
7184 BUG_ON(page_count(page));
7185 BUG_ON(!PageBuddy(page));
7186 order = page_order(page);
7187 #ifdef CONFIG_DEBUG_VM
7188 printk(KERN_INFO "remove from free list %lx %d %lx\n",
7189 pfn, 1 << order, end_pfn);
7191 list_del(&page->lru);
7192 rmv_page_order(page);
7193 zone->free_area[order].nr_free--;
7194 for (i = 0; i < (1 << order); i++)
7195 SetPageReserved((page+i));
7196 pfn += (1 << order);
7198 spin_unlock_irqrestore(&zone->lock, flags);
7202 bool is_free_buddy_page(struct page *page)
7204 struct zone *zone = page_zone(page);
7205 unsigned long pfn = page_to_pfn(page);
7206 unsigned long flags;
7209 spin_lock_irqsave(&zone->lock, flags);
7210 for (order = 0; order < MAX_ORDER; order++) {
7211 struct page *page_head = page - (pfn & ((1 << order) - 1));
7213 if (PageBuddy(page_head) && page_order(page_head) >= order)
7216 spin_unlock_irqrestore(&zone->lock, flags);
7218 return order < MAX_ORDER;