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>
66 #include <linux/memcontrol.h>
68 #include <asm/sections.h>
69 #include <asm/tlbflush.h>
70 #include <asm/div64.h>
73 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
74 static DEFINE_MUTEX(pcp_batch_high_lock);
75 #define MIN_PERCPU_PAGELIST_FRACTION (8)
77 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
78 DEFINE_PER_CPU(int, numa_node);
79 EXPORT_PER_CPU_SYMBOL(numa_node);
82 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
84 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
85 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
86 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
87 * defined in <linux/topology.h>.
89 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
90 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
91 int _node_numa_mem_[MAX_NUMNODES];
94 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
95 volatile u64 latent_entropy __latent_entropy;
96 EXPORT_SYMBOL(latent_entropy);
100 * Array of node states.
102 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
103 [N_POSSIBLE] = NODE_MASK_ALL,
104 [N_ONLINE] = { { [0] = 1UL } },
106 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
107 #ifdef CONFIG_HIGHMEM
108 [N_HIGH_MEMORY] = { { [0] = 1UL } },
110 #ifdef CONFIG_MOVABLE_NODE
111 [N_MEMORY] = { { [0] = 1UL } },
113 [N_CPU] = { { [0] = 1UL } },
116 EXPORT_SYMBOL(node_states);
118 /* Protect totalram_pages and zone->managed_pages */
119 static DEFINE_SPINLOCK(managed_page_count_lock);
121 unsigned long totalram_pages __read_mostly;
122 unsigned long totalreserve_pages __read_mostly;
123 unsigned long totalcma_pages __read_mostly;
125 int percpu_pagelist_fraction;
126 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
129 * A cached value of the page's pageblock's migratetype, used when the page is
130 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
131 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
132 * Also the migratetype set in the page does not necessarily match the pcplist
133 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
134 * other index - this ensures that it will be put on the correct CMA freelist.
136 static inline int get_pcppage_migratetype(struct page *page)
141 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
143 page->index = migratetype;
146 #ifdef CONFIG_PM_SLEEP
148 * The following functions are used by the suspend/hibernate code to temporarily
149 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
150 * while devices are suspended. To avoid races with the suspend/hibernate code,
151 * they should always be called with pm_mutex held (gfp_allowed_mask also should
152 * only be modified with pm_mutex held, unless the suspend/hibernate code is
153 * guaranteed not to run in parallel with that modification).
156 static gfp_t saved_gfp_mask;
158 void pm_restore_gfp_mask(void)
160 WARN_ON(!mutex_is_locked(&pm_mutex));
161 if (saved_gfp_mask) {
162 gfp_allowed_mask = saved_gfp_mask;
167 void pm_restrict_gfp_mask(void)
169 WARN_ON(!mutex_is_locked(&pm_mutex));
170 WARN_ON(saved_gfp_mask);
171 saved_gfp_mask = gfp_allowed_mask;
172 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
175 bool pm_suspended_storage(void)
177 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
181 #endif /* CONFIG_PM_SLEEP */
183 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
184 unsigned int pageblock_order __read_mostly;
187 static void __free_pages_ok(struct page *page, unsigned int order);
190 * results with 256, 32 in the lowmem_reserve sysctl:
191 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
192 * 1G machine -> (16M dma, 784M normal, 224M high)
193 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
194 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
195 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
197 * TBD: should special case ZONE_DMA32 machines here - in those we normally
198 * don't need any ZONE_NORMAL reservation
200 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
201 #ifdef CONFIG_ZONE_DMA
204 #ifdef CONFIG_ZONE_DMA32
207 #ifdef CONFIG_HIGHMEM
213 EXPORT_SYMBOL(totalram_pages);
215 static char * const zone_names[MAX_NR_ZONES] = {
216 #ifdef CONFIG_ZONE_DMA
219 #ifdef CONFIG_ZONE_DMA32
223 #ifdef CONFIG_HIGHMEM
227 #ifdef CONFIG_ZONE_DEVICE
232 char * const migratetype_names[MIGRATE_TYPES] = {
240 #ifdef CONFIG_MEMORY_ISOLATION
245 compound_page_dtor * const compound_page_dtors[] = {
248 #ifdef CONFIG_HUGETLB_PAGE
251 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
256 int min_free_kbytes = 1024;
257 int user_min_free_kbytes = -1;
258 int watermark_scale_factor = 10;
260 static unsigned long __meminitdata nr_kernel_pages;
261 static unsigned long __meminitdata nr_all_pages;
262 static unsigned long __meminitdata dma_reserve;
264 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
265 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
266 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
267 static unsigned long __initdata required_kernelcore;
268 static unsigned long __initdata required_movablecore;
269 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
270 static bool mirrored_kernelcore;
272 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
274 EXPORT_SYMBOL(movable_zone);
275 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
278 int nr_node_ids __read_mostly = MAX_NUMNODES;
279 int nr_online_nodes __read_mostly = 1;
280 EXPORT_SYMBOL(nr_node_ids);
281 EXPORT_SYMBOL(nr_online_nodes);
284 int page_group_by_mobility_disabled __read_mostly;
286 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
287 static inline void reset_deferred_meminit(pg_data_t *pgdat)
289 pgdat->first_deferred_pfn = ULONG_MAX;
292 /* Returns true if the struct page for the pfn is uninitialised */
293 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
295 int nid = early_pfn_to_nid(pfn);
297 if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
304 * Returns false when the remaining initialisation should be deferred until
305 * later in the boot cycle when it can be parallelised.
307 static inline bool update_defer_init(pg_data_t *pgdat,
308 unsigned long pfn, unsigned long zone_end,
309 unsigned long *nr_initialised)
311 unsigned long max_initialise;
313 /* Always populate low zones for address-contrained allocations */
314 if (zone_end < pgdat_end_pfn(pgdat))
317 * Initialise at least 2G of a node but also take into account that
318 * two large system hashes that can take up 1GB for 0.25TB/node.
320 max_initialise = max(2UL << (30 - PAGE_SHIFT),
321 (pgdat->node_spanned_pages >> 8));
324 if ((*nr_initialised > max_initialise) &&
325 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
326 pgdat->first_deferred_pfn = pfn;
333 static inline void reset_deferred_meminit(pg_data_t *pgdat)
337 static inline bool early_page_uninitialised(unsigned long pfn)
342 static inline bool update_defer_init(pg_data_t *pgdat,
343 unsigned long pfn, unsigned long zone_end,
344 unsigned long *nr_initialised)
350 /* Return a pointer to the bitmap storing bits affecting a block of pages */
351 static inline unsigned long *get_pageblock_bitmap(struct page *page,
354 #ifdef CONFIG_SPARSEMEM
355 return __pfn_to_section(pfn)->pageblock_flags;
357 return page_zone(page)->pageblock_flags;
358 #endif /* CONFIG_SPARSEMEM */
361 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
363 #ifdef CONFIG_SPARSEMEM
364 pfn &= (PAGES_PER_SECTION-1);
365 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
367 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
368 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
369 #endif /* CONFIG_SPARSEMEM */
373 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
374 * @page: The page within the block of interest
375 * @pfn: The target page frame number
376 * @end_bitidx: The last bit of interest to retrieve
377 * @mask: mask of bits that the caller is interested in
379 * Return: pageblock_bits flags
381 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
383 unsigned long end_bitidx,
386 unsigned long *bitmap;
387 unsigned long bitidx, word_bitidx;
390 bitmap = get_pageblock_bitmap(page, pfn);
391 bitidx = pfn_to_bitidx(page, pfn);
392 word_bitidx = bitidx / BITS_PER_LONG;
393 bitidx &= (BITS_PER_LONG-1);
395 word = bitmap[word_bitidx];
396 bitidx += end_bitidx;
397 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
400 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
401 unsigned long end_bitidx,
404 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
407 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
409 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
413 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
414 * @page: The page within the block of interest
415 * @flags: The flags to set
416 * @pfn: The target page frame number
417 * @end_bitidx: The last bit of interest
418 * @mask: mask of bits that the caller is interested in
420 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
422 unsigned long end_bitidx,
425 unsigned long *bitmap;
426 unsigned long bitidx, word_bitidx;
427 unsigned long old_word, word;
429 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
431 bitmap = get_pageblock_bitmap(page, pfn);
432 bitidx = pfn_to_bitidx(page, pfn);
433 word_bitidx = bitidx / BITS_PER_LONG;
434 bitidx &= (BITS_PER_LONG-1);
436 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
438 bitidx += end_bitidx;
439 mask <<= (BITS_PER_LONG - bitidx - 1);
440 flags <<= (BITS_PER_LONG - bitidx - 1);
442 word = READ_ONCE(bitmap[word_bitidx]);
444 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
445 if (word == old_word)
451 void set_pageblock_migratetype(struct page *page, int migratetype)
453 if (unlikely(page_group_by_mobility_disabled &&
454 migratetype < MIGRATE_PCPTYPES))
455 migratetype = MIGRATE_UNMOVABLE;
457 set_pageblock_flags_group(page, (unsigned long)migratetype,
458 PB_migrate, PB_migrate_end);
461 #ifdef CONFIG_DEBUG_VM
462 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
466 unsigned long pfn = page_to_pfn(page);
467 unsigned long sp, start_pfn;
470 seq = zone_span_seqbegin(zone);
471 start_pfn = zone->zone_start_pfn;
472 sp = zone->spanned_pages;
473 if (!zone_spans_pfn(zone, pfn))
475 } while (zone_span_seqretry(zone, seq));
478 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
479 pfn, zone_to_nid(zone), zone->name,
480 start_pfn, start_pfn + sp);
485 static int page_is_consistent(struct zone *zone, struct page *page)
487 if (!pfn_valid_within(page_to_pfn(page)))
489 if (zone != page_zone(page))
495 * Temporary debugging check for pages not lying within a given zone.
497 static int bad_range(struct zone *zone, struct page *page)
499 if (page_outside_zone_boundaries(zone, page))
501 if (!page_is_consistent(zone, page))
507 static inline int bad_range(struct zone *zone, struct page *page)
513 static void bad_page(struct page *page, const char *reason,
514 unsigned long bad_flags)
516 static unsigned long resume;
517 static unsigned long nr_shown;
518 static unsigned long nr_unshown;
521 * Allow a burst of 60 reports, then keep quiet for that minute;
522 * or allow a steady drip of one report per second.
524 if (nr_shown == 60) {
525 if (time_before(jiffies, resume)) {
531 "BUG: Bad page state: %lu messages suppressed\n",
538 resume = jiffies + 60 * HZ;
540 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
541 current->comm, page_to_pfn(page));
542 __dump_page(page, reason);
543 bad_flags &= page->flags;
545 pr_alert("bad because of flags: %#lx(%pGp)\n",
546 bad_flags, &bad_flags);
547 dump_page_owner(page);
552 /* Leave bad fields for debug, except PageBuddy could make trouble */
553 page_mapcount_reset(page); /* remove PageBuddy */
554 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
558 * Higher-order pages are called "compound pages". They are structured thusly:
560 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
562 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
563 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
565 * The first tail page's ->compound_dtor holds the offset in array of compound
566 * page destructors. See compound_page_dtors.
568 * The first tail page's ->compound_order holds the order of allocation.
569 * This usage means that zero-order pages may not be compound.
572 void free_compound_page(struct page *page)
574 __free_pages_ok(page, compound_order(page));
577 void prep_compound_page(struct page *page, unsigned int order)
580 int nr_pages = 1 << order;
582 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
583 set_compound_order(page, order);
585 for (i = 1; i < nr_pages; i++) {
586 struct page *p = page + i;
587 set_page_count(p, 0);
588 p->mapping = TAIL_MAPPING;
589 set_compound_head(p, page);
591 atomic_set(compound_mapcount_ptr(page), -1);
594 #ifdef CONFIG_DEBUG_PAGEALLOC
595 unsigned int _debug_guardpage_minorder;
596 bool _debug_pagealloc_enabled __read_mostly
597 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
598 EXPORT_SYMBOL(_debug_pagealloc_enabled);
599 bool _debug_guardpage_enabled __read_mostly;
601 static int __init early_debug_pagealloc(char *buf)
605 return kstrtobool(buf, &_debug_pagealloc_enabled);
607 early_param("debug_pagealloc", early_debug_pagealloc);
609 static bool need_debug_guardpage(void)
611 /* If we don't use debug_pagealloc, we don't need guard page */
612 if (!debug_pagealloc_enabled())
615 if (!debug_guardpage_minorder())
621 static void init_debug_guardpage(void)
623 if (!debug_pagealloc_enabled())
626 if (!debug_guardpage_minorder())
629 _debug_guardpage_enabled = true;
632 struct page_ext_operations debug_guardpage_ops = {
633 .need = need_debug_guardpage,
634 .init = init_debug_guardpage,
637 static int __init debug_guardpage_minorder_setup(char *buf)
641 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
642 pr_err("Bad debug_guardpage_minorder value\n");
645 _debug_guardpage_minorder = res;
646 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
649 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
651 static inline bool set_page_guard(struct zone *zone, struct page *page,
652 unsigned int order, int migratetype)
654 struct page_ext *page_ext;
656 if (!debug_guardpage_enabled())
659 if (order >= debug_guardpage_minorder())
662 page_ext = lookup_page_ext(page);
663 if (unlikely(!page_ext))
666 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
668 INIT_LIST_HEAD(&page->lru);
669 set_page_private(page, order);
670 /* Guard pages are not available for any usage */
671 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
676 static inline void clear_page_guard(struct zone *zone, struct page *page,
677 unsigned int order, int migratetype)
679 struct page_ext *page_ext;
681 if (!debug_guardpage_enabled())
684 page_ext = lookup_page_ext(page);
685 if (unlikely(!page_ext))
688 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
690 set_page_private(page, 0);
691 if (!is_migrate_isolate(migratetype))
692 __mod_zone_freepage_state(zone, (1 << order), migratetype);
695 struct page_ext_operations debug_guardpage_ops;
696 static inline bool set_page_guard(struct zone *zone, struct page *page,
697 unsigned int order, int migratetype) { return false; }
698 static inline void clear_page_guard(struct zone *zone, struct page *page,
699 unsigned int order, int migratetype) {}
702 static inline void set_page_order(struct page *page, unsigned int order)
704 set_page_private(page, order);
705 __SetPageBuddy(page);
708 static inline void rmv_page_order(struct page *page)
710 __ClearPageBuddy(page);
711 set_page_private(page, 0);
715 * This function checks whether a page is free && is the buddy
716 * we can do coalesce a page and its buddy if
717 * (a) the buddy is not in a hole &&
718 * (b) the buddy is in the buddy system &&
719 * (c) a page and its buddy have the same order &&
720 * (d) a page and its buddy are in the same zone.
722 * For recording whether a page is in the buddy system, we set ->_mapcount
723 * PAGE_BUDDY_MAPCOUNT_VALUE.
724 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
725 * serialized by zone->lock.
727 * For recording page's order, we use page_private(page).
729 static inline int page_is_buddy(struct page *page, struct page *buddy,
732 if (!pfn_valid_within(page_to_pfn(buddy)))
735 if (page_is_guard(buddy) && page_order(buddy) == order) {
736 if (page_zone_id(page) != page_zone_id(buddy))
739 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
744 if (PageBuddy(buddy) && page_order(buddy) == order) {
746 * zone check is done late to avoid uselessly
747 * calculating zone/node ids for pages that could
750 if (page_zone_id(page) != page_zone_id(buddy))
753 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
761 * Freeing function for a buddy system allocator.
763 * The concept of a buddy system is to maintain direct-mapped table
764 * (containing bit values) for memory blocks of various "orders".
765 * The bottom level table contains the map for the smallest allocatable
766 * units of memory (here, pages), and each level above it describes
767 * pairs of units from the levels below, hence, "buddies".
768 * At a high level, all that happens here is marking the table entry
769 * at the bottom level available, and propagating the changes upward
770 * as necessary, plus some accounting needed to play nicely with other
771 * parts of the VM system.
772 * At each level, we keep a list of pages, which are heads of continuous
773 * free pages of length of (1 << order) and marked with _mapcount
774 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
776 * So when we are allocating or freeing one, we can derive the state of the
777 * other. That is, if we allocate a small block, and both were
778 * free, the remainder of the region must be split into blocks.
779 * If a block is freed, and its buddy is also free, then this
780 * triggers coalescing into a block of larger size.
785 static inline void __free_one_page(struct page *page,
787 struct zone *zone, unsigned int order,
790 unsigned long page_idx;
791 unsigned long combined_idx;
792 unsigned long uninitialized_var(buddy_idx);
794 unsigned int max_order;
796 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
798 VM_BUG_ON(!zone_is_initialized(zone));
799 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
801 VM_BUG_ON(migratetype == -1);
802 if (likely(!is_migrate_isolate(migratetype)))
803 __mod_zone_freepage_state(zone, 1 << order, migratetype);
805 page_idx = pfn & ((1 << MAX_ORDER) - 1);
807 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
808 VM_BUG_ON_PAGE(bad_range(zone, page), page);
811 while (order < max_order - 1) {
812 buddy_idx = __find_buddy_index(page_idx, order);
813 buddy = page + (buddy_idx - page_idx);
814 if (!page_is_buddy(page, buddy, order))
817 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
818 * merge with it and move up one order.
820 if (page_is_guard(buddy)) {
821 clear_page_guard(zone, buddy, order, migratetype);
823 list_del(&buddy->lru);
824 zone->free_area[order].nr_free--;
825 rmv_page_order(buddy);
827 combined_idx = buddy_idx & page_idx;
828 page = page + (combined_idx - page_idx);
829 page_idx = combined_idx;
832 if (max_order < MAX_ORDER) {
833 /* If we are here, it means order is >= pageblock_order.
834 * We want to prevent merge between freepages on isolate
835 * pageblock and normal pageblock. Without this, pageblock
836 * isolation could cause incorrect freepage or CMA accounting.
838 * We don't want to hit this code for the more frequent
841 if (unlikely(has_isolate_pageblock(zone))) {
844 buddy_idx = __find_buddy_index(page_idx, order);
845 buddy = page + (buddy_idx - page_idx);
846 buddy_mt = get_pageblock_migratetype(buddy);
848 if (migratetype != buddy_mt
849 && (is_migrate_isolate(migratetype) ||
850 is_migrate_isolate(buddy_mt)))
854 goto continue_merging;
858 set_page_order(page, order);
861 * If this is not the largest possible page, check if the buddy
862 * of the next-highest order is free. If it is, it's possible
863 * that pages are being freed that will coalesce soon. In case,
864 * that is happening, add the free page to the tail of the list
865 * so it's less likely to be used soon and more likely to be merged
866 * as a higher order page
868 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
869 struct page *higher_page, *higher_buddy;
870 combined_idx = buddy_idx & page_idx;
871 higher_page = page + (combined_idx - page_idx);
872 buddy_idx = __find_buddy_index(combined_idx, order + 1);
873 higher_buddy = higher_page + (buddy_idx - combined_idx);
874 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
875 list_add_tail(&page->lru,
876 &zone->free_area[order].free_list[migratetype]);
881 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
883 zone->free_area[order].nr_free++;
887 * A bad page could be due to a number of fields. Instead of multiple branches,
888 * try and check multiple fields with one check. The caller must do a detailed
889 * check if necessary.
891 static inline bool page_expected_state(struct page *page,
892 unsigned long check_flags)
894 if (unlikely(atomic_read(&page->_mapcount) != -1))
897 if (unlikely((unsigned long)page->mapping |
898 page_ref_count(page) |
900 (unsigned long)page->mem_cgroup |
902 (page->flags & check_flags)))
908 static void free_pages_check_bad(struct page *page)
910 const char *bad_reason;
911 unsigned long bad_flags;
916 if (unlikely(atomic_read(&page->_mapcount) != -1))
917 bad_reason = "nonzero mapcount";
918 if (unlikely(page->mapping != NULL))
919 bad_reason = "non-NULL mapping";
920 if (unlikely(page_ref_count(page) != 0))
921 bad_reason = "nonzero _refcount";
922 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
923 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
924 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
927 if (unlikely(page->mem_cgroup))
928 bad_reason = "page still charged to cgroup";
930 bad_page(page, bad_reason, bad_flags);
933 static inline int free_pages_check(struct page *page)
935 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
938 /* Something has gone sideways, find it */
939 free_pages_check_bad(page);
943 static int free_tail_pages_check(struct page *head_page, struct page *page)
948 * We rely page->lru.next never has bit 0 set, unless the page
949 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
951 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
953 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
957 switch (page - head_page) {
959 /* the first tail page: ->mapping is compound_mapcount() */
960 if (unlikely(compound_mapcount(page))) {
961 bad_page(page, "nonzero compound_mapcount", 0);
967 * the second tail page: ->mapping is
968 * page_deferred_list().next -- ignore value.
972 if (page->mapping != TAIL_MAPPING) {
973 bad_page(page, "corrupted mapping in tail page", 0);
978 if (unlikely(!PageTail(page))) {
979 bad_page(page, "PageTail not set", 0);
982 if (unlikely(compound_head(page) != head_page)) {
983 bad_page(page, "compound_head not consistent", 0);
988 page->mapping = NULL;
989 clear_compound_head(page);
993 static __always_inline bool free_pages_prepare(struct page *page,
994 unsigned int order, bool check_free)
998 VM_BUG_ON_PAGE(PageTail(page), page);
1000 trace_mm_page_free(page, order);
1001 kmemcheck_free_shadow(page, order);
1004 * Check tail pages before head page information is cleared to
1005 * avoid checking PageCompound for order-0 pages.
1007 if (unlikely(order)) {
1008 bool compound = PageCompound(page);
1011 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1014 ClearPageDoubleMap(page);
1015 for (i = 1; i < (1 << order); i++) {
1017 bad += free_tail_pages_check(page, page + i);
1018 if (unlikely(free_pages_check(page + i))) {
1022 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1025 if (PageMappingFlags(page))
1026 page->mapping = NULL;
1027 if (memcg_kmem_enabled() && PageKmemcg(page))
1028 memcg_kmem_uncharge(page, order);
1030 bad += free_pages_check(page);
1034 page_cpupid_reset_last(page);
1035 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1036 reset_page_owner(page, order);
1038 if (!PageHighMem(page)) {
1039 debug_check_no_locks_freed(page_address(page),
1040 PAGE_SIZE << order);
1041 debug_check_no_obj_freed(page_address(page),
1042 PAGE_SIZE << order);
1044 arch_free_page(page, order);
1045 kernel_poison_pages(page, 1 << order, 0);
1046 kernel_map_pages(page, 1 << order, 0);
1047 kasan_free_pages(page, order);
1052 #ifdef CONFIG_DEBUG_VM
1053 static inline bool free_pcp_prepare(struct page *page)
1055 return free_pages_prepare(page, 0, true);
1058 static inline bool bulkfree_pcp_prepare(struct page *page)
1063 static bool free_pcp_prepare(struct page *page)
1065 return free_pages_prepare(page, 0, false);
1068 static bool bulkfree_pcp_prepare(struct page *page)
1070 return free_pages_check(page);
1072 #endif /* CONFIG_DEBUG_VM */
1075 * Frees a number of pages from the PCP lists
1076 * Assumes all pages on list are in same zone, and of same order.
1077 * count is the number of pages to free.
1079 * If the zone was previously in an "all pages pinned" state then look to
1080 * see if this freeing clears that state.
1082 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1083 * pinned" detection logic.
1085 static void free_pcppages_bulk(struct zone *zone, int count,
1086 struct per_cpu_pages *pcp)
1088 int migratetype = 0;
1090 unsigned long nr_scanned;
1091 bool isolated_pageblocks;
1093 spin_lock(&zone->lock);
1094 isolated_pageblocks = has_isolate_pageblock(zone);
1095 nr_scanned = node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED);
1097 __mod_node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED, -nr_scanned);
1101 struct list_head *list;
1104 * Remove pages from lists in a round-robin fashion. A
1105 * batch_free count is maintained that is incremented when an
1106 * empty list is encountered. This is so more pages are freed
1107 * off fuller lists instead of spinning excessively around empty
1112 if (++migratetype == MIGRATE_PCPTYPES)
1114 list = &pcp->lists[migratetype];
1115 } while (list_empty(list));
1117 /* This is the only non-empty list. Free them all. */
1118 if (batch_free == MIGRATE_PCPTYPES)
1122 int mt; /* migratetype of the to-be-freed page */
1124 page = list_last_entry(list, struct page, lru);
1125 /* must delete as __free_one_page list manipulates */
1126 list_del(&page->lru);
1128 mt = get_pcppage_migratetype(page);
1129 /* MIGRATE_ISOLATE page should not go to pcplists */
1130 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1131 /* Pageblock could have been isolated meanwhile */
1132 if (unlikely(isolated_pageblocks))
1133 mt = get_pageblock_migratetype(page);
1135 if (bulkfree_pcp_prepare(page))
1138 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1139 trace_mm_page_pcpu_drain(page, 0, mt);
1140 } while (--count && --batch_free && !list_empty(list));
1142 spin_unlock(&zone->lock);
1145 static void free_one_page(struct zone *zone,
1146 struct page *page, unsigned long pfn,
1150 unsigned long nr_scanned;
1151 spin_lock(&zone->lock);
1152 nr_scanned = node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED);
1154 __mod_node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED, -nr_scanned);
1156 if (unlikely(has_isolate_pageblock(zone) ||
1157 is_migrate_isolate(migratetype))) {
1158 migratetype = get_pfnblock_migratetype(page, pfn);
1160 __free_one_page(page, pfn, zone, order, migratetype);
1161 spin_unlock(&zone->lock);
1164 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1165 unsigned long zone, int nid)
1167 set_page_links(page, zone, nid, pfn);
1168 init_page_count(page);
1169 page_mapcount_reset(page);
1170 page_cpupid_reset_last(page);
1172 INIT_LIST_HEAD(&page->lru);
1173 #ifdef WANT_PAGE_VIRTUAL
1174 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1175 if (!is_highmem_idx(zone))
1176 set_page_address(page, __va(pfn << PAGE_SHIFT));
1180 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
1183 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
1186 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1187 static void init_reserved_page(unsigned long pfn)
1192 if (!early_page_uninitialised(pfn))
1195 nid = early_pfn_to_nid(pfn);
1196 pgdat = NODE_DATA(nid);
1198 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1199 struct zone *zone = &pgdat->node_zones[zid];
1201 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1204 __init_single_pfn(pfn, zid, nid);
1207 static inline void init_reserved_page(unsigned long pfn)
1210 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1213 * Initialised pages do not have PageReserved set. This function is
1214 * called for each range allocated by the bootmem allocator and
1215 * marks the pages PageReserved. The remaining valid pages are later
1216 * sent to the buddy page allocator.
1218 void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
1220 unsigned long start_pfn = PFN_DOWN(start);
1221 unsigned long end_pfn = PFN_UP(end);
1223 for (; start_pfn < end_pfn; start_pfn++) {
1224 if (pfn_valid(start_pfn)) {
1225 struct page *page = pfn_to_page(start_pfn);
1227 init_reserved_page(start_pfn);
1229 /* Avoid false-positive PageTail() */
1230 INIT_LIST_HEAD(&page->lru);
1232 SetPageReserved(page);
1237 static void __free_pages_ok(struct page *page, unsigned int order)
1239 unsigned long flags;
1241 unsigned long pfn = page_to_pfn(page);
1243 if (!free_pages_prepare(page, order, true))
1246 migratetype = get_pfnblock_migratetype(page, pfn);
1247 local_irq_save(flags);
1248 __count_vm_events(PGFREE, 1 << order);
1249 free_one_page(page_zone(page), page, pfn, order, migratetype);
1250 local_irq_restore(flags);
1253 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1255 unsigned int nr_pages = 1 << order;
1256 struct page *p = page;
1260 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1262 __ClearPageReserved(p);
1263 set_page_count(p, 0);
1265 __ClearPageReserved(p);
1266 set_page_count(p, 0);
1268 page_zone(page)->managed_pages += nr_pages;
1269 set_page_refcounted(page);
1270 __free_pages(page, order);
1273 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1274 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1276 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1278 int __meminit early_pfn_to_nid(unsigned long pfn)
1280 static DEFINE_SPINLOCK(early_pfn_lock);
1283 spin_lock(&early_pfn_lock);
1284 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1286 nid = first_online_node;
1287 spin_unlock(&early_pfn_lock);
1293 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1294 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1295 struct mminit_pfnnid_cache *state)
1299 nid = __early_pfn_to_nid(pfn, state);
1300 if (nid >= 0 && nid != node)
1305 /* Only safe to use early in boot when initialisation is single-threaded */
1306 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1308 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1313 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1317 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1318 struct mminit_pfnnid_cache *state)
1325 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1328 if (early_page_uninitialised(pfn))
1330 return __free_pages_boot_core(page, order);
1334 * Check that the whole (or subset of) a pageblock given by the interval of
1335 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1336 * with the migration of free compaction scanner. The scanners then need to
1337 * use only pfn_valid_within() check for arches that allow holes within
1340 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1342 * It's possible on some configurations to have a setup like node0 node1 node0
1343 * i.e. it's possible that all pages within a zones range of pages do not
1344 * belong to a single zone. We assume that a border between node0 and node1
1345 * can occur within a single pageblock, but not a node0 node1 node0
1346 * interleaving within a single pageblock. It is therefore sufficient to check
1347 * the first and last page of a pageblock and avoid checking each individual
1348 * page in a pageblock.
1350 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1351 unsigned long end_pfn, struct zone *zone)
1353 struct page *start_page;
1354 struct page *end_page;
1356 /* end_pfn is one past the range we are checking */
1359 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1362 start_page = pfn_to_page(start_pfn);
1364 if (page_zone(start_page) != zone)
1367 end_page = pfn_to_page(end_pfn);
1369 /* This gives a shorter code than deriving page_zone(end_page) */
1370 if (page_zone_id(start_page) != page_zone_id(end_page))
1376 void set_zone_contiguous(struct zone *zone)
1378 unsigned long block_start_pfn = zone->zone_start_pfn;
1379 unsigned long block_end_pfn;
1381 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1382 for (; block_start_pfn < zone_end_pfn(zone);
1383 block_start_pfn = block_end_pfn,
1384 block_end_pfn += pageblock_nr_pages) {
1386 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1388 if (!__pageblock_pfn_to_page(block_start_pfn,
1389 block_end_pfn, zone))
1393 /* We confirm that there is no hole */
1394 zone->contiguous = true;
1397 void clear_zone_contiguous(struct zone *zone)
1399 zone->contiguous = false;
1402 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1403 static void __init deferred_free_range(struct page *page,
1404 unsigned long pfn, int nr_pages)
1411 /* Free a large naturally-aligned chunk if possible */
1412 if (nr_pages == pageblock_nr_pages &&
1413 (pfn & (pageblock_nr_pages - 1)) == 0) {
1414 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1415 __free_pages_boot_core(page, pageblock_order);
1419 for (i = 0; i < nr_pages; i++, page++, pfn++) {
1420 if ((pfn & (pageblock_nr_pages - 1)) == 0)
1421 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1422 __free_pages_boot_core(page, 0);
1426 /* Completion tracking for deferred_init_memmap() threads */
1427 static atomic_t pgdat_init_n_undone __initdata;
1428 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1430 static inline void __init pgdat_init_report_one_done(void)
1432 if (atomic_dec_and_test(&pgdat_init_n_undone))
1433 complete(&pgdat_init_all_done_comp);
1436 /* Initialise remaining memory on a node */
1437 static int __init deferred_init_memmap(void *data)
1439 pg_data_t *pgdat = data;
1440 int nid = pgdat->node_id;
1441 struct mminit_pfnnid_cache nid_init_state = { };
1442 unsigned long start = jiffies;
1443 unsigned long nr_pages = 0;
1444 unsigned long walk_start, walk_end;
1447 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1448 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1450 if (first_init_pfn == ULONG_MAX) {
1451 pgdat_init_report_one_done();
1455 /* Bind memory initialisation thread to a local node if possible */
1456 if (!cpumask_empty(cpumask))
1457 set_cpus_allowed_ptr(current, cpumask);
1459 /* Sanity check boundaries */
1460 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1461 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1462 pgdat->first_deferred_pfn = ULONG_MAX;
1464 /* Only the highest zone is deferred so find it */
1465 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1466 zone = pgdat->node_zones + zid;
1467 if (first_init_pfn < zone_end_pfn(zone))
1471 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1472 unsigned long pfn, end_pfn;
1473 struct page *page = NULL;
1474 struct page *free_base_page = NULL;
1475 unsigned long free_base_pfn = 0;
1478 end_pfn = min(walk_end, zone_end_pfn(zone));
1479 pfn = first_init_pfn;
1480 if (pfn < walk_start)
1482 if (pfn < zone->zone_start_pfn)
1483 pfn = zone->zone_start_pfn;
1485 for (; pfn < end_pfn; pfn++) {
1486 if (!pfn_valid_within(pfn))
1490 * Ensure pfn_valid is checked every
1491 * pageblock_nr_pages for memory holes
1493 if ((pfn & (pageblock_nr_pages - 1)) == 0) {
1494 if (!pfn_valid(pfn)) {
1500 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1505 /* Minimise pfn page lookups and scheduler checks */
1506 if (page && (pfn & (pageblock_nr_pages - 1)) != 0) {
1509 nr_pages += nr_to_free;
1510 deferred_free_range(free_base_page,
1511 free_base_pfn, nr_to_free);
1512 free_base_page = NULL;
1513 free_base_pfn = nr_to_free = 0;
1515 page = pfn_to_page(pfn);
1520 VM_BUG_ON(page_zone(page) != zone);
1524 __init_single_page(page, pfn, zid, nid);
1525 if (!free_base_page) {
1526 free_base_page = page;
1527 free_base_pfn = pfn;
1532 /* Where possible, batch up pages for a single free */
1535 /* Free the current block of pages to allocator */
1536 nr_pages += nr_to_free;
1537 deferred_free_range(free_base_page, free_base_pfn,
1539 free_base_page = NULL;
1540 free_base_pfn = nr_to_free = 0;
1542 /* Free the last block of pages to allocator */
1543 nr_pages += nr_to_free;
1544 deferred_free_range(free_base_page, free_base_pfn, nr_to_free);
1546 first_init_pfn = max(end_pfn, first_init_pfn);
1549 /* Sanity check that the next zone really is unpopulated */
1550 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1552 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1553 jiffies_to_msecs(jiffies - start));
1555 pgdat_init_report_one_done();
1558 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1560 void __init page_alloc_init_late(void)
1564 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1567 /* There will be num_node_state(N_MEMORY) threads */
1568 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1569 for_each_node_state(nid, N_MEMORY) {
1570 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1573 /* Block until all are initialised */
1574 wait_for_completion(&pgdat_init_all_done_comp);
1576 /* Reinit limits that are based on free pages after the kernel is up */
1577 files_maxfiles_init();
1580 for_each_populated_zone(zone)
1581 set_zone_contiguous(zone);
1585 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1586 void __init init_cma_reserved_pageblock(struct page *page)
1588 unsigned i = pageblock_nr_pages;
1589 struct page *p = page;
1592 __ClearPageReserved(p);
1593 set_page_count(p, 0);
1596 set_pageblock_migratetype(page, MIGRATE_CMA);
1598 if (pageblock_order >= MAX_ORDER) {
1599 i = pageblock_nr_pages;
1602 set_page_refcounted(p);
1603 __free_pages(p, MAX_ORDER - 1);
1604 p += MAX_ORDER_NR_PAGES;
1605 } while (i -= MAX_ORDER_NR_PAGES);
1607 set_page_refcounted(page);
1608 __free_pages(page, pageblock_order);
1611 adjust_managed_page_count(page, pageblock_nr_pages);
1616 * The order of subdivision here is critical for the IO subsystem.
1617 * Please do not alter this order without good reasons and regression
1618 * testing. Specifically, as large blocks of memory are subdivided,
1619 * the order in which smaller blocks are delivered depends on the order
1620 * they're subdivided in this function. This is the primary factor
1621 * influencing the order in which pages are delivered to the IO
1622 * subsystem according to empirical testing, and this is also justified
1623 * by considering the behavior of a buddy system containing a single
1624 * large block of memory acted on by a series of small allocations.
1625 * This behavior is a critical factor in sglist merging's success.
1629 static inline void expand(struct zone *zone, struct page *page,
1630 int low, int high, struct free_area *area,
1633 unsigned long size = 1 << high;
1635 while (high > low) {
1639 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1642 * Mark as guard pages (or page), that will allow to
1643 * merge back to allocator when buddy will be freed.
1644 * Corresponding page table entries will not be touched,
1645 * pages will stay not present in virtual address space
1647 if (set_page_guard(zone, &page[size], high, migratetype))
1650 list_add(&page[size].lru, &area->free_list[migratetype]);
1652 set_page_order(&page[size], high);
1656 static void check_new_page_bad(struct page *page)
1658 const char *bad_reason = NULL;
1659 unsigned long bad_flags = 0;
1661 if (unlikely(atomic_read(&page->_mapcount) != -1))
1662 bad_reason = "nonzero mapcount";
1663 if (unlikely(page->mapping != NULL))
1664 bad_reason = "non-NULL mapping";
1665 if (unlikely(page_ref_count(page) != 0))
1666 bad_reason = "nonzero _count";
1667 if (unlikely(page->flags & __PG_HWPOISON)) {
1668 bad_reason = "HWPoisoned (hardware-corrupted)";
1669 bad_flags = __PG_HWPOISON;
1670 /* Don't complain about hwpoisoned pages */
1671 page_mapcount_reset(page); /* remove PageBuddy */
1674 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1675 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1676 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1679 if (unlikely(page->mem_cgroup))
1680 bad_reason = "page still charged to cgroup";
1682 bad_page(page, bad_reason, bad_flags);
1686 * This page is about to be returned from the page allocator
1688 static inline int check_new_page(struct page *page)
1690 if (likely(page_expected_state(page,
1691 PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
1694 check_new_page_bad(page);
1698 static inline bool free_pages_prezeroed(bool poisoned)
1700 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1701 page_poisoning_enabled() && poisoned;
1704 #ifdef CONFIG_DEBUG_VM
1705 static bool check_pcp_refill(struct page *page)
1710 static bool check_new_pcp(struct page *page)
1712 return check_new_page(page);
1715 static bool check_pcp_refill(struct page *page)
1717 return check_new_page(page);
1719 static bool check_new_pcp(struct page *page)
1723 #endif /* CONFIG_DEBUG_VM */
1725 static bool check_new_pages(struct page *page, unsigned int order)
1728 for (i = 0; i < (1 << order); i++) {
1729 struct page *p = page + i;
1731 if (unlikely(check_new_page(p)))
1738 inline void post_alloc_hook(struct page *page, unsigned int order,
1741 set_page_private(page, 0);
1742 set_page_refcounted(page);
1744 arch_alloc_page(page, order);
1745 kernel_map_pages(page, 1 << order, 1);
1746 kernel_poison_pages(page, 1 << order, 1);
1747 kasan_alloc_pages(page, order);
1748 set_page_owner(page, order, gfp_flags);
1751 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1752 unsigned int alloc_flags)
1755 bool poisoned = true;
1757 for (i = 0; i < (1 << order); i++) {
1758 struct page *p = page + i;
1760 poisoned &= page_is_poisoned(p);
1763 post_alloc_hook(page, order, gfp_flags);
1765 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1766 for (i = 0; i < (1 << order); i++)
1767 clear_highpage(page + i);
1769 if (order && (gfp_flags & __GFP_COMP))
1770 prep_compound_page(page, order);
1773 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1774 * allocate the page. The expectation is that the caller is taking
1775 * steps that will free more memory. The caller should avoid the page
1776 * being used for !PFMEMALLOC purposes.
1778 if (alloc_flags & ALLOC_NO_WATERMARKS)
1779 set_page_pfmemalloc(page);
1781 clear_page_pfmemalloc(page);
1785 * Go through the free lists for the given migratetype and remove
1786 * the smallest available page from the freelists
1789 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1792 unsigned int current_order;
1793 struct free_area *area;
1796 /* Find a page of the appropriate size in the preferred list */
1797 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1798 area = &(zone->free_area[current_order]);
1799 page = list_first_entry_or_null(&area->free_list[migratetype],
1803 list_del(&page->lru);
1804 rmv_page_order(page);
1806 expand(zone, page, order, current_order, area, migratetype);
1807 set_pcppage_migratetype(page, migratetype);
1816 * This array describes the order lists are fallen back to when
1817 * the free lists for the desirable migrate type are depleted
1819 static int fallbacks[MIGRATE_TYPES][4] = {
1820 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1821 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1822 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1824 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1826 #ifdef CONFIG_MEMORY_ISOLATION
1827 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1832 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1835 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1838 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1839 unsigned int order) { return NULL; }
1843 * Move the free pages in a range to the free lists of the requested type.
1844 * Note that start_page and end_pages are not aligned on a pageblock
1845 * boundary. If alignment is required, use move_freepages_block()
1847 int move_freepages(struct zone *zone,
1848 struct page *start_page, struct page *end_page,
1853 int pages_moved = 0;
1855 #ifndef CONFIG_HOLES_IN_ZONE
1857 * page_zone is not safe to call in this context when
1858 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1859 * anyway as we check zone boundaries in move_freepages_block().
1860 * Remove at a later date when no bug reports exist related to
1861 * grouping pages by mobility
1863 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1866 for (page = start_page; page <= end_page;) {
1867 /* Make sure we are not inadvertently changing nodes */
1868 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1870 if (!pfn_valid_within(page_to_pfn(page))) {
1875 if (!PageBuddy(page)) {
1880 order = page_order(page);
1881 list_move(&page->lru,
1882 &zone->free_area[order].free_list[migratetype]);
1884 pages_moved += 1 << order;
1890 int move_freepages_block(struct zone *zone, struct page *page,
1893 unsigned long start_pfn, end_pfn;
1894 struct page *start_page, *end_page;
1896 start_pfn = page_to_pfn(page);
1897 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1898 start_page = pfn_to_page(start_pfn);
1899 end_page = start_page + pageblock_nr_pages - 1;
1900 end_pfn = start_pfn + pageblock_nr_pages - 1;
1902 /* Do not cross zone boundaries */
1903 if (!zone_spans_pfn(zone, start_pfn))
1905 if (!zone_spans_pfn(zone, end_pfn))
1908 return move_freepages(zone, start_page, end_page, migratetype);
1911 static void change_pageblock_range(struct page *pageblock_page,
1912 int start_order, int migratetype)
1914 int nr_pageblocks = 1 << (start_order - pageblock_order);
1916 while (nr_pageblocks--) {
1917 set_pageblock_migratetype(pageblock_page, migratetype);
1918 pageblock_page += pageblock_nr_pages;
1923 * When we are falling back to another migratetype during allocation, try to
1924 * steal extra free pages from the same pageblocks to satisfy further
1925 * allocations, instead of polluting multiple pageblocks.
1927 * If we are stealing a relatively large buddy page, it is likely there will
1928 * be more free pages in the pageblock, so try to steal them all. For
1929 * reclaimable and unmovable allocations, we steal regardless of page size,
1930 * as fragmentation caused by those allocations polluting movable pageblocks
1931 * is worse than movable allocations stealing from unmovable and reclaimable
1934 static bool can_steal_fallback(unsigned int order, int start_mt)
1937 * Leaving this order check is intended, although there is
1938 * relaxed order check in next check. The reason is that
1939 * we can actually steal whole pageblock if this condition met,
1940 * but, below check doesn't guarantee it and that is just heuristic
1941 * so could be changed anytime.
1943 if (order >= pageblock_order)
1946 if (order >= pageblock_order / 2 ||
1947 start_mt == MIGRATE_RECLAIMABLE ||
1948 start_mt == MIGRATE_UNMOVABLE ||
1949 page_group_by_mobility_disabled)
1956 * This function implements actual steal behaviour. If order is large enough,
1957 * we can steal whole pageblock. If not, we first move freepages in this
1958 * pageblock and check whether half of pages are moved or not. If half of
1959 * pages are moved, we can change migratetype of pageblock and permanently
1960 * use it's pages as requested migratetype in the future.
1962 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1965 unsigned int current_order = page_order(page);
1968 /* Take ownership for orders >= pageblock_order */
1969 if (current_order >= pageblock_order) {
1970 change_pageblock_range(page, current_order, start_type);
1974 pages = move_freepages_block(zone, page, start_type);
1976 /* Claim the whole block if over half of it is free */
1977 if (pages >= (1 << (pageblock_order-1)) ||
1978 page_group_by_mobility_disabled)
1979 set_pageblock_migratetype(page, start_type);
1983 * Check whether there is a suitable fallback freepage with requested order.
1984 * If only_stealable is true, this function returns fallback_mt only if
1985 * we can steal other freepages all together. This would help to reduce
1986 * fragmentation due to mixed migratetype pages in one pageblock.
1988 int find_suitable_fallback(struct free_area *area, unsigned int order,
1989 int migratetype, bool only_stealable, bool *can_steal)
1994 if (area->nr_free == 0)
1999 fallback_mt = fallbacks[migratetype][i];
2000 if (fallback_mt == MIGRATE_TYPES)
2003 if (list_empty(&area->free_list[fallback_mt]))
2006 if (can_steal_fallback(order, migratetype))
2009 if (!only_stealable)
2020 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2021 * there are no empty page blocks that contain a page with a suitable order
2023 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2024 unsigned int alloc_order)
2027 unsigned long max_managed, flags;
2030 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2031 * Check is race-prone but harmless.
2033 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2034 if (zone->nr_reserved_highatomic >= max_managed)
2037 spin_lock_irqsave(&zone->lock, flags);
2039 /* Recheck the nr_reserved_highatomic limit under the lock */
2040 if (zone->nr_reserved_highatomic >= max_managed)
2044 mt = get_pageblock_migratetype(page);
2045 if (mt != MIGRATE_HIGHATOMIC &&
2046 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
2047 zone->nr_reserved_highatomic += pageblock_nr_pages;
2048 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2049 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
2053 spin_unlock_irqrestore(&zone->lock, flags);
2057 * Used when an allocation is about to fail under memory pressure. This
2058 * potentially hurts the reliability of high-order allocations when under
2059 * intense memory pressure but failed atomic allocations should be easier
2060 * to recover from than an OOM.
2062 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
2064 struct zonelist *zonelist = ac->zonelist;
2065 unsigned long flags;
2071 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2073 /* Preserve at least one pageblock */
2074 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
2077 spin_lock_irqsave(&zone->lock, flags);
2078 for (order = 0; order < MAX_ORDER; order++) {
2079 struct free_area *area = &(zone->free_area[order]);
2081 page = list_first_entry_or_null(
2082 &area->free_list[MIGRATE_HIGHATOMIC],
2088 * It should never happen but changes to locking could
2089 * inadvertently allow a per-cpu drain to add pages
2090 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2091 * and watch for underflows.
2093 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
2094 zone->nr_reserved_highatomic);
2097 * Convert to ac->migratetype and avoid the normal
2098 * pageblock stealing heuristics. Minimally, the caller
2099 * is doing the work and needs the pages. More
2100 * importantly, if the block was always converted to
2101 * MIGRATE_UNMOVABLE or another type then the number
2102 * of pageblocks that cannot be completely freed
2105 set_pageblock_migratetype(page, ac->migratetype);
2106 move_freepages_block(zone, page, ac->migratetype);
2107 spin_unlock_irqrestore(&zone->lock, flags);
2110 spin_unlock_irqrestore(&zone->lock, flags);
2114 /* Remove an element from the buddy allocator from the fallback list */
2115 static inline struct page *
2116 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
2118 struct free_area *area;
2119 unsigned int current_order;
2124 /* Find the largest possible block of pages in the other list */
2125 for (current_order = MAX_ORDER-1;
2126 current_order >= order && current_order <= MAX_ORDER-1;
2128 area = &(zone->free_area[current_order]);
2129 fallback_mt = find_suitable_fallback(area, current_order,
2130 start_migratetype, false, &can_steal);
2131 if (fallback_mt == -1)
2134 page = list_first_entry(&area->free_list[fallback_mt],
2137 steal_suitable_fallback(zone, page, start_migratetype);
2139 /* Remove the page from the freelists */
2141 list_del(&page->lru);
2142 rmv_page_order(page);
2144 expand(zone, page, order, current_order, area,
2147 * The pcppage_migratetype may differ from pageblock's
2148 * migratetype depending on the decisions in
2149 * find_suitable_fallback(). This is OK as long as it does not
2150 * differ for MIGRATE_CMA pageblocks. Those can be used as
2151 * fallback only via special __rmqueue_cma_fallback() function
2153 set_pcppage_migratetype(page, start_migratetype);
2155 trace_mm_page_alloc_extfrag(page, order, current_order,
2156 start_migratetype, fallback_mt);
2165 * Do the hard work of removing an element from the buddy allocator.
2166 * Call me with the zone->lock already held.
2168 static struct page *__rmqueue(struct zone *zone, unsigned int order,
2173 page = __rmqueue_smallest(zone, order, migratetype);
2174 if (unlikely(!page)) {
2175 if (migratetype == MIGRATE_MOVABLE)
2176 page = __rmqueue_cma_fallback(zone, order);
2179 page = __rmqueue_fallback(zone, order, migratetype);
2182 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2187 * Obtain a specified number of elements from the buddy allocator, all under
2188 * a single hold of the lock, for efficiency. Add them to the supplied list.
2189 * Returns the number of new pages which were placed at *list.
2191 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2192 unsigned long count, struct list_head *list,
2193 int migratetype, bool cold)
2197 spin_lock(&zone->lock);
2198 for (i = 0; i < count; ++i) {
2199 struct page *page = __rmqueue(zone, order, migratetype);
2200 if (unlikely(page == NULL))
2203 if (unlikely(check_pcp_refill(page)))
2207 * Split buddy pages returned by expand() are received here
2208 * in physical page order. The page is added to the callers and
2209 * list and the list head then moves forward. From the callers
2210 * perspective, the linked list is ordered by page number in
2211 * some conditions. This is useful for IO devices that can
2212 * merge IO requests if the physical pages are ordered
2216 list_add(&page->lru, list);
2218 list_add_tail(&page->lru, list);
2220 if (is_migrate_cma(get_pcppage_migratetype(page)))
2221 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2224 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2225 spin_unlock(&zone->lock);
2231 * Called from the vmstat counter updater to drain pagesets of this
2232 * currently executing processor on remote nodes after they have
2235 * Note that this function must be called with the thread pinned to
2236 * a single processor.
2238 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2240 unsigned long flags;
2241 int to_drain, batch;
2243 local_irq_save(flags);
2244 batch = READ_ONCE(pcp->batch);
2245 to_drain = min(pcp->count, batch);
2247 free_pcppages_bulk(zone, to_drain, pcp);
2248 pcp->count -= to_drain;
2250 local_irq_restore(flags);
2255 * Drain pcplists of the indicated processor and zone.
2257 * The processor must either be the current processor and the
2258 * thread pinned to the current processor or a processor that
2261 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2263 unsigned long flags;
2264 struct per_cpu_pageset *pset;
2265 struct per_cpu_pages *pcp;
2267 local_irq_save(flags);
2268 pset = per_cpu_ptr(zone->pageset, cpu);
2272 free_pcppages_bulk(zone, pcp->count, pcp);
2275 local_irq_restore(flags);
2279 * Drain pcplists of all zones on the indicated processor.
2281 * The processor must either be the current processor and the
2282 * thread pinned to the current processor or a processor that
2285 static void drain_pages(unsigned int cpu)
2289 for_each_populated_zone(zone) {
2290 drain_pages_zone(cpu, zone);
2295 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2297 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2298 * the single zone's pages.
2300 void drain_local_pages(struct zone *zone)
2302 int cpu = smp_processor_id();
2305 drain_pages_zone(cpu, zone);
2311 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2313 * When zone parameter is non-NULL, spill just the single zone's pages.
2315 * Note that this code is protected against sending an IPI to an offline
2316 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2317 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2318 * nothing keeps CPUs from showing up after we populated the cpumask and
2319 * before the call to on_each_cpu_mask().
2321 void drain_all_pages(struct zone *zone)
2326 * Allocate in the BSS so we wont require allocation in
2327 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2329 static cpumask_t cpus_with_pcps;
2332 * We don't care about racing with CPU hotplug event
2333 * as offline notification will cause the notified
2334 * cpu to drain that CPU pcps and on_each_cpu_mask
2335 * disables preemption as part of its processing
2337 for_each_online_cpu(cpu) {
2338 struct per_cpu_pageset *pcp;
2340 bool has_pcps = false;
2343 pcp = per_cpu_ptr(zone->pageset, cpu);
2347 for_each_populated_zone(z) {
2348 pcp = per_cpu_ptr(z->pageset, cpu);
2349 if (pcp->pcp.count) {
2357 cpumask_set_cpu(cpu, &cpus_with_pcps);
2359 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2361 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2365 #ifdef CONFIG_HIBERNATION
2367 void mark_free_pages(struct zone *zone)
2369 unsigned long pfn, max_zone_pfn;
2370 unsigned long flags;
2371 unsigned int order, t;
2374 if (zone_is_empty(zone))
2377 spin_lock_irqsave(&zone->lock, flags);
2379 max_zone_pfn = zone_end_pfn(zone);
2380 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2381 if (pfn_valid(pfn)) {
2382 page = pfn_to_page(pfn);
2384 if (page_zone(page) != zone)
2387 if (!swsusp_page_is_forbidden(page))
2388 swsusp_unset_page_free(page);
2391 for_each_migratetype_order(order, t) {
2392 list_for_each_entry(page,
2393 &zone->free_area[order].free_list[t], lru) {
2396 pfn = page_to_pfn(page);
2397 for (i = 0; i < (1UL << order); i++)
2398 swsusp_set_page_free(pfn_to_page(pfn + i));
2401 spin_unlock_irqrestore(&zone->lock, flags);
2403 #endif /* CONFIG_PM */
2406 * Free a 0-order page
2407 * cold == true ? free a cold page : free a hot page
2409 void free_hot_cold_page(struct page *page, bool cold)
2411 struct zone *zone = page_zone(page);
2412 struct per_cpu_pages *pcp;
2413 unsigned long flags;
2414 unsigned long pfn = page_to_pfn(page);
2417 if (!free_pcp_prepare(page))
2420 migratetype = get_pfnblock_migratetype(page, pfn);
2421 set_pcppage_migratetype(page, migratetype);
2422 local_irq_save(flags);
2423 __count_vm_event(PGFREE);
2426 * We only track unmovable, reclaimable and movable on pcp lists.
2427 * Free ISOLATE pages back to the allocator because they are being
2428 * offlined but treat RESERVE as movable pages so we can get those
2429 * areas back if necessary. Otherwise, we may have to free
2430 * excessively into the page allocator
2432 if (migratetype >= MIGRATE_PCPTYPES) {
2433 if (unlikely(is_migrate_isolate(migratetype))) {
2434 free_one_page(zone, page, pfn, 0, migratetype);
2437 migratetype = MIGRATE_MOVABLE;
2440 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2442 list_add(&page->lru, &pcp->lists[migratetype]);
2444 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2446 if (pcp->count >= pcp->high) {
2447 unsigned long batch = READ_ONCE(pcp->batch);
2448 free_pcppages_bulk(zone, batch, pcp);
2449 pcp->count -= batch;
2453 local_irq_restore(flags);
2457 * Free a list of 0-order pages
2459 void free_hot_cold_page_list(struct list_head *list, bool cold)
2461 struct page *page, *next;
2463 list_for_each_entry_safe(page, next, list, lru) {
2464 trace_mm_page_free_batched(page, cold);
2465 free_hot_cold_page(page, cold);
2470 * split_page takes a non-compound higher-order page, and splits it into
2471 * n (1<<order) sub-pages: page[0..n]
2472 * Each sub-page must be freed individually.
2474 * Note: this is probably too low level an operation for use in drivers.
2475 * Please consult with lkml before using this in your driver.
2477 void split_page(struct page *page, unsigned int order)
2481 VM_BUG_ON_PAGE(PageCompound(page), page);
2482 VM_BUG_ON_PAGE(!page_count(page), page);
2484 #ifdef CONFIG_KMEMCHECK
2486 * Split shadow pages too, because free(page[0]) would
2487 * otherwise free the whole shadow.
2489 if (kmemcheck_page_is_tracked(page))
2490 split_page(virt_to_page(page[0].shadow), order);
2493 for (i = 1; i < (1 << order); i++)
2494 set_page_refcounted(page + i);
2495 split_page_owner(page, order);
2497 EXPORT_SYMBOL_GPL(split_page);
2499 int __isolate_free_page(struct page *page, unsigned int order)
2501 unsigned long watermark;
2505 BUG_ON(!PageBuddy(page));
2507 zone = page_zone(page);
2508 mt = get_pageblock_migratetype(page);
2510 if (!is_migrate_isolate(mt)) {
2512 * Obey watermarks as if the page was being allocated. We can
2513 * emulate a high-order watermark check with a raised order-0
2514 * watermark, because we already know our high-order page
2517 watermark = min_wmark_pages(zone) + (1UL << order);
2518 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
2521 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2524 /* Remove page from free list */
2525 list_del(&page->lru);
2526 zone->free_area[order].nr_free--;
2527 rmv_page_order(page);
2530 * Set the pageblock if the isolated page is at least half of a
2533 if (order >= pageblock_order - 1) {
2534 struct page *endpage = page + (1 << order) - 1;
2535 for (; page < endpage; page += pageblock_nr_pages) {
2536 int mt = get_pageblock_migratetype(page);
2537 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2538 set_pageblock_migratetype(page,
2544 return 1UL << order;
2548 * Update NUMA hit/miss statistics
2550 * Must be called with interrupts disabled.
2552 * When __GFP_OTHER_NODE is set assume the node of the preferred
2553 * zone is the local node. This is useful for daemons who allocate
2554 * memory on behalf of other processes.
2556 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2560 int local_nid = numa_node_id();
2561 enum zone_stat_item local_stat = NUMA_LOCAL;
2563 if (unlikely(flags & __GFP_OTHER_NODE)) {
2564 local_stat = NUMA_OTHER;
2565 local_nid = preferred_zone->node;
2568 if (z->node == local_nid) {
2569 __inc_zone_state(z, NUMA_HIT);
2570 __inc_zone_state(z, local_stat);
2572 __inc_zone_state(z, NUMA_MISS);
2573 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2579 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2582 struct page *buffered_rmqueue(struct zone *preferred_zone,
2583 struct zone *zone, unsigned int order,
2584 gfp_t gfp_flags, unsigned int alloc_flags,
2587 unsigned long flags;
2589 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2591 if (likely(order == 0)) {
2592 struct per_cpu_pages *pcp;
2593 struct list_head *list;
2595 local_irq_save(flags);
2597 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2598 list = &pcp->lists[migratetype];
2599 if (list_empty(list)) {
2600 pcp->count += rmqueue_bulk(zone, 0,
2603 if (unlikely(list_empty(list)))
2608 page = list_last_entry(list, struct page, lru);
2610 page = list_first_entry(list, struct page, lru);
2612 list_del(&page->lru);
2615 } while (check_new_pcp(page));
2618 * We most definitely don't want callers attempting to
2619 * allocate greater than order-1 page units with __GFP_NOFAIL.
2621 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2622 spin_lock_irqsave(&zone->lock, flags);
2626 if (alloc_flags & ALLOC_HARDER) {
2627 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2629 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2632 page = __rmqueue(zone, order, migratetype);
2633 } while (page && check_new_pages(page, order));
2634 spin_unlock(&zone->lock);
2637 __mod_zone_freepage_state(zone, -(1 << order),
2638 get_pcppage_migratetype(page));
2641 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
2642 zone_statistics(preferred_zone, zone, gfp_flags);
2643 local_irq_restore(flags);
2645 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2649 local_irq_restore(flags);
2653 #ifdef CONFIG_FAIL_PAGE_ALLOC
2656 struct fault_attr attr;
2658 bool ignore_gfp_highmem;
2659 bool ignore_gfp_reclaim;
2661 } fail_page_alloc = {
2662 .attr = FAULT_ATTR_INITIALIZER,
2663 .ignore_gfp_reclaim = true,
2664 .ignore_gfp_highmem = true,
2668 static int __init setup_fail_page_alloc(char *str)
2670 return setup_fault_attr(&fail_page_alloc.attr, str);
2672 __setup("fail_page_alloc=", setup_fail_page_alloc);
2674 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2676 if (order < fail_page_alloc.min_order)
2678 if (gfp_mask & __GFP_NOFAIL)
2680 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2682 if (fail_page_alloc.ignore_gfp_reclaim &&
2683 (gfp_mask & __GFP_DIRECT_RECLAIM))
2686 return should_fail(&fail_page_alloc.attr, 1 << order);
2689 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2691 static int __init fail_page_alloc_debugfs(void)
2693 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2696 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2697 &fail_page_alloc.attr);
2699 return PTR_ERR(dir);
2701 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2702 &fail_page_alloc.ignore_gfp_reclaim))
2704 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2705 &fail_page_alloc.ignore_gfp_highmem))
2707 if (!debugfs_create_u32("min-order", mode, dir,
2708 &fail_page_alloc.min_order))
2713 debugfs_remove_recursive(dir);
2718 late_initcall(fail_page_alloc_debugfs);
2720 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2722 #else /* CONFIG_FAIL_PAGE_ALLOC */
2724 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2729 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2732 * Return true if free base pages are above 'mark'. For high-order checks it
2733 * will return true of the order-0 watermark is reached and there is at least
2734 * one free page of a suitable size. Checking now avoids taking the zone lock
2735 * to check in the allocation paths if no pages are free.
2737 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2738 int classzone_idx, unsigned int alloc_flags,
2743 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2745 /* free_pages may go negative - that's OK */
2746 free_pages -= (1 << order) - 1;
2748 if (alloc_flags & ALLOC_HIGH)
2752 * If the caller does not have rights to ALLOC_HARDER then subtract
2753 * the high-atomic reserves. This will over-estimate the size of the
2754 * atomic reserve but it avoids a search.
2756 if (likely(!alloc_harder))
2757 free_pages -= z->nr_reserved_highatomic;
2762 /* If allocation can't use CMA areas don't use free CMA pages */
2763 if (!(alloc_flags & ALLOC_CMA))
2764 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2768 * Check watermarks for an order-0 allocation request. If these
2769 * are not met, then a high-order request also cannot go ahead
2770 * even if a suitable page happened to be free.
2772 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2775 /* If this is an order-0 request then the watermark is fine */
2779 /* For a high-order request, check at least one suitable page is free */
2780 for (o = order; o < MAX_ORDER; o++) {
2781 struct free_area *area = &z->free_area[o];
2790 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2791 if (!list_empty(&area->free_list[mt]))
2796 if ((alloc_flags & ALLOC_CMA) &&
2797 !list_empty(&area->free_list[MIGRATE_CMA])) {
2805 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2806 int classzone_idx, unsigned int alloc_flags)
2808 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2809 zone_page_state(z, NR_FREE_PAGES));
2812 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2813 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2815 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2819 /* If allocation can't use CMA areas don't use free CMA pages */
2820 if (!(alloc_flags & ALLOC_CMA))
2821 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2825 * Fast check for order-0 only. If this fails then the reserves
2826 * need to be calculated. There is a corner case where the check
2827 * passes but only the high-order atomic reserve are free. If
2828 * the caller is !atomic then it'll uselessly search the free
2829 * list. That corner case is then slower but it is harmless.
2831 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2834 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2838 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2839 unsigned long mark, int classzone_idx)
2841 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2843 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2844 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2846 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2851 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2853 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2856 #else /* CONFIG_NUMA */
2857 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2861 #endif /* CONFIG_NUMA */
2864 * get_page_from_freelist goes through the zonelist trying to allocate
2867 static struct page *
2868 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2869 const struct alloc_context *ac)
2871 struct zoneref *z = ac->preferred_zoneref;
2873 struct pglist_data *last_pgdat_dirty_limit = NULL;
2876 * Scan zonelist, looking for a zone with enough free.
2877 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2879 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
2884 if (cpusets_enabled() &&
2885 (alloc_flags & ALLOC_CPUSET) &&
2886 !__cpuset_zone_allowed(zone, gfp_mask))
2889 * When allocating a page cache page for writing, we
2890 * want to get it from a node that is within its dirty
2891 * limit, such that no single node holds more than its
2892 * proportional share of globally allowed dirty pages.
2893 * The dirty limits take into account the node's
2894 * lowmem reserves and high watermark so that kswapd
2895 * should be able to balance it without having to
2896 * write pages from its LRU list.
2898 * XXX: For now, allow allocations to potentially
2899 * exceed the per-node dirty limit in the slowpath
2900 * (spread_dirty_pages unset) before going into reclaim,
2901 * which is important when on a NUMA setup the allowed
2902 * nodes are together not big enough to reach the
2903 * global limit. The proper fix for these situations
2904 * will require awareness of nodes in the
2905 * dirty-throttling and the flusher threads.
2907 if (ac->spread_dirty_pages) {
2908 if (last_pgdat_dirty_limit == zone->zone_pgdat)
2911 if (!node_dirty_ok(zone->zone_pgdat)) {
2912 last_pgdat_dirty_limit = zone->zone_pgdat;
2917 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2918 if (!zone_watermark_fast(zone, order, mark,
2919 ac_classzone_idx(ac), alloc_flags)) {
2922 /* Checked here to keep the fast path fast */
2923 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2924 if (alloc_flags & ALLOC_NO_WATERMARKS)
2927 if (node_reclaim_mode == 0 ||
2928 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
2931 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
2933 case NODE_RECLAIM_NOSCAN:
2936 case NODE_RECLAIM_FULL:
2937 /* scanned but unreclaimable */
2940 /* did we reclaim enough */
2941 if (zone_watermark_ok(zone, order, mark,
2942 ac_classzone_idx(ac), alloc_flags))
2950 page = buffered_rmqueue(ac->preferred_zoneref->zone, zone, order,
2951 gfp_mask, alloc_flags, ac->migratetype);
2953 prep_new_page(page, order, gfp_mask, alloc_flags);
2956 * If this is a high-order atomic allocation then check
2957 * if the pageblock should be reserved for the future
2959 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2960 reserve_highatomic_pageblock(page, zone, order);
2970 * Large machines with many possible nodes should not always dump per-node
2971 * meminfo in irq context.
2973 static inline bool should_suppress_show_mem(void)
2978 ret = in_interrupt();
2983 static DEFINE_RATELIMIT_STATE(nopage_rs,
2984 DEFAULT_RATELIMIT_INTERVAL,
2985 DEFAULT_RATELIMIT_BURST);
2987 void warn_alloc(gfp_t gfp_mask, const char *fmt, ...)
2989 unsigned int filter = SHOW_MEM_FILTER_NODES;
2990 struct va_format vaf;
2993 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2994 debug_guardpage_minorder() > 0)
2998 * This documents exceptions given to allocations in certain
2999 * contexts that are allowed to allocate outside current's set
3002 if (!(gfp_mask & __GFP_NOMEMALLOC))
3003 if (test_thread_flag(TIF_MEMDIE) ||
3004 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3005 filter &= ~SHOW_MEM_FILTER_NODES;
3006 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3007 filter &= ~SHOW_MEM_FILTER_NODES;
3009 pr_warn("%s: ", current->comm);
3011 va_start(args, fmt);
3014 pr_cont("%pV", &vaf);
3017 pr_cont(", mode:%#x(%pGg)\n", gfp_mask, &gfp_mask);
3020 if (!should_suppress_show_mem())
3024 static inline struct page *
3025 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3026 const struct alloc_context *ac, unsigned long *did_some_progress)
3028 struct oom_control oc = {
3029 .zonelist = ac->zonelist,
3030 .nodemask = ac->nodemask,
3032 .gfp_mask = gfp_mask,
3037 *did_some_progress = 0;
3040 * Acquire the oom lock. If that fails, somebody else is
3041 * making progress for us.
3043 if (!mutex_trylock(&oom_lock)) {
3044 *did_some_progress = 1;
3045 schedule_timeout_uninterruptible(1);
3050 * Go through the zonelist yet one more time, keep very high watermark
3051 * here, this is only to catch a parallel oom killing, we must fail if
3052 * we're still under heavy pressure.
3054 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3055 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3059 if (!(gfp_mask & __GFP_NOFAIL)) {
3060 /* Coredumps can quickly deplete all memory reserves */
3061 if (current->flags & PF_DUMPCORE)
3063 /* The OOM killer will not help higher order allocs */
3064 if (order > PAGE_ALLOC_COSTLY_ORDER)
3066 /* The OOM killer does not needlessly kill tasks for lowmem */
3067 if (ac->high_zoneidx < ZONE_NORMAL)
3069 if (pm_suspended_storage())
3072 * XXX: GFP_NOFS allocations should rather fail than rely on
3073 * other request to make a forward progress.
3074 * We are in an unfortunate situation where out_of_memory cannot
3075 * do much for this context but let's try it to at least get
3076 * access to memory reserved if the current task is killed (see
3077 * out_of_memory). Once filesystems are ready to handle allocation
3078 * failures more gracefully we should just bail out here.
3081 /* The OOM killer may not free memory on a specific node */
3082 if (gfp_mask & __GFP_THISNODE)
3085 /* Exhausted what can be done so it's blamo time */
3086 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3087 *did_some_progress = 1;
3089 if (gfp_mask & __GFP_NOFAIL) {
3090 page = get_page_from_freelist(gfp_mask, order,
3091 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
3093 * fallback to ignore cpuset restriction if our nodes
3097 page = get_page_from_freelist(gfp_mask, order,
3098 ALLOC_NO_WATERMARKS, ac);
3102 mutex_unlock(&oom_lock);
3107 * Maximum number of compaction retries wit a progress before OOM
3108 * killer is consider as the only way to move forward.
3110 #define MAX_COMPACT_RETRIES 16
3112 #ifdef CONFIG_COMPACTION
3113 /* Try memory compaction for high-order allocations before reclaim */
3114 static struct page *
3115 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3116 unsigned int alloc_flags, const struct alloc_context *ac,
3117 enum compact_priority prio, enum compact_result *compact_result)
3124 current->flags |= PF_MEMALLOC;
3125 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3127 current->flags &= ~PF_MEMALLOC;
3129 if (*compact_result <= COMPACT_INACTIVE)
3133 * At least in one zone compaction wasn't deferred or skipped, so let's
3134 * count a compaction stall
3136 count_vm_event(COMPACTSTALL);
3138 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3141 struct zone *zone = page_zone(page);
3143 zone->compact_blockskip_flush = false;
3144 compaction_defer_reset(zone, order, true);
3145 count_vm_event(COMPACTSUCCESS);
3150 * It's bad if compaction run occurs and fails. The most likely reason
3151 * is that pages exist, but not enough to satisfy watermarks.
3153 count_vm_event(COMPACTFAIL);
3161 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3162 enum compact_result compact_result,
3163 enum compact_priority *compact_priority,
3164 int *compaction_retries)
3166 int max_retries = MAX_COMPACT_RETRIES;
3172 if (compaction_made_progress(compact_result))
3173 (*compaction_retries)++;
3176 * compaction considers all the zone as desperately out of memory
3177 * so it doesn't really make much sense to retry except when the
3178 * failure could be caused by insufficient priority
3180 if (compaction_failed(compact_result))
3181 goto check_priority;
3184 * make sure the compaction wasn't deferred or didn't bail out early
3185 * due to locks contention before we declare that we should give up.
3186 * But do not retry if the given zonelist is not suitable for
3189 if (compaction_withdrawn(compact_result))
3190 return compaction_zonelist_suitable(ac, order, alloc_flags);
3193 * !costly requests are much more important than __GFP_REPEAT
3194 * costly ones because they are de facto nofail and invoke OOM
3195 * killer to move on while costly can fail and users are ready
3196 * to cope with that. 1/4 retries is rather arbitrary but we
3197 * would need much more detailed feedback from compaction to
3198 * make a better decision.
3200 if (order > PAGE_ALLOC_COSTLY_ORDER)
3202 if (*compaction_retries <= max_retries)
3206 * Make sure there are attempts at the highest priority if we exhausted
3207 * all retries or failed at the lower priorities.
3210 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
3211 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
3212 if (*compact_priority > min_priority) {
3213 (*compact_priority)--;
3214 *compaction_retries = 0;
3220 static inline struct page *
3221 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3222 unsigned int alloc_flags, const struct alloc_context *ac,
3223 enum compact_priority prio, enum compact_result *compact_result)
3225 *compact_result = COMPACT_SKIPPED;
3230 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3231 enum compact_result compact_result,
3232 enum compact_priority *compact_priority,
3233 int *compaction_retries)
3238 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
3242 * There are setups with compaction disabled which would prefer to loop
3243 * inside the allocator rather than hit the oom killer prematurely.
3244 * Let's give them a good hope and keep retrying while the order-0
3245 * watermarks are OK.
3247 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3249 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
3250 ac_classzone_idx(ac), alloc_flags))
3255 #endif /* CONFIG_COMPACTION */
3257 /* Perform direct synchronous page reclaim */
3259 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3260 const struct alloc_context *ac)
3262 struct reclaim_state reclaim_state;
3267 /* We now go into synchronous reclaim */
3268 cpuset_memory_pressure_bump();
3269 current->flags |= PF_MEMALLOC;
3270 lockdep_set_current_reclaim_state(gfp_mask);
3271 reclaim_state.reclaimed_slab = 0;
3272 current->reclaim_state = &reclaim_state;
3274 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3277 current->reclaim_state = NULL;
3278 lockdep_clear_current_reclaim_state();
3279 current->flags &= ~PF_MEMALLOC;
3286 /* The really slow allocator path where we enter direct reclaim */
3287 static inline struct page *
3288 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3289 unsigned int alloc_flags, const struct alloc_context *ac,
3290 unsigned long *did_some_progress)
3292 struct page *page = NULL;
3293 bool drained = false;
3295 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3296 if (unlikely(!(*did_some_progress)))
3300 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3303 * If an allocation failed after direct reclaim, it could be because
3304 * pages are pinned on the per-cpu lists or in high alloc reserves.
3305 * Shrink them them and try again
3307 if (!page && !drained) {
3308 unreserve_highatomic_pageblock(ac);
3309 drain_all_pages(NULL);
3317 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3321 pg_data_t *last_pgdat = NULL;
3323 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3324 ac->high_zoneidx, ac->nodemask) {
3325 if (last_pgdat != zone->zone_pgdat)
3326 wakeup_kswapd(zone, order, ac->high_zoneidx);
3327 last_pgdat = zone->zone_pgdat;
3331 static inline unsigned int
3332 gfp_to_alloc_flags(gfp_t gfp_mask)
3334 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3336 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3337 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3340 * The caller may dip into page reserves a bit more if the caller
3341 * cannot run direct reclaim, or if the caller has realtime scheduling
3342 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3343 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3345 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3347 if (gfp_mask & __GFP_ATOMIC) {
3349 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3350 * if it can't schedule.
3352 if (!(gfp_mask & __GFP_NOMEMALLOC))
3353 alloc_flags |= ALLOC_HARDER;
3355 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3356 * comment for __cpuset_node_allowed().
3358 alloc_flags &= ~ALLOC_CPUSET;
3359 } else if (unlikely(rt_task(current)) && !in_interrupt())
3360 alloc_flags |= ALLOC_HARDER;
3363 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3364 alloc_flags |= ALLOC_CMA;
3369 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3371 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
3374 if (gfp_mask & __GFP_MEMALLOC)
3376 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3378 if (!in_interrupt() &&
3379 ((current->flags & PF_MEMALLOC) ||
3380 unlikely(test_thread_flag(TIF_MEMDIE))))
3387 * Maximum number of reclaim retries without any progress before OOM killer
3388 * is consider as the only way to move forward.
3390 #define MAX_RECLAIM_RETRIES 16
3393 * Checks whether it makes sense to retry the reclaim to make a forward progress
3394 * for the given allocation request.
3395 * The reclaim feedback represented by did_some_progress (any progress during
3396 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3397 * any progress in a row) is considered as well as the reclaimable pages on the
3398 * applicable zone list (with a backoff mechanism which is a function of
3399 * no_progress_loops).
3401 * Returns true if a retry is viable or false to enter the oom path.
3404 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3405 struct alloc_context *ac, int alloc_flags,
3406 bool did_some_progress, int *no_progress_loops)
3412 * Costly allocations might have made a progress but this doesn't mean
3413 * their order will become available due to high fragmentation so
3414 * always increment the no progress counter for them
3416 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3417 *no_progress_loops = 0;
3419 (*no_progress_loops)++;
3422 * Make sure we converge to OOM if we cannot make any progress
3423 * several times in the row.
3425 if (*no_progress_loops > MAX_RECLAIM_RETRIES)
3429 * Keep reclaiming pages while there is a chance this will lead
3430 * somewhere. If none of the target zones can satisfy our allocation
3431 * request even if all reclaimable pages are considered then we are
3432 * screwed and have to go OOM.
3434 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3436 unsigned long available;
3437 unsigned long reclaimable;
3439 available = reclaimable = zone_reclaimable_pages(zone);
3440 available -= DIV_ROUND_UP((*no_progress_loops) * available,
3441 MAX_RECLAIM_RETRIES);
3442 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3445 * Would the allocation succeed if we reclaimed the whole
3448 if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
3449 ac_classzone_idx(ac), alloc_flags, available)) {
3451 * If we didn't make any progress and have a lot of
3452 * dirty + writeback pages then we should wait for
3453 * an IO to complete to slow down the reclaim and
3454 * prevent from pre mature OOM
3456 if (!did_some_progress) {
3457 unsigned long write_pending;
3459 write_pending = zone_page_state_snapshot(zone,
3460 NR_ZONE_WRITE_PENDING);
3462 if (2 * write_pending > reclaimable) {
3463 congestion_wait(BLK_RW_ASYNC, HZ/10);
3469 * Memory allocation/reclaim might be called from a WQ
3470 * context and the current implementation of the WQ
3471 * concurrency control doesn't recognize that
3472 * a particular WQ is congested if the worker thread is
3473 * looping without ever sleeping. Therefore we have to
3474 * do a short sleep here rather than calling
3477 if (current->flags & PF_WQ_WORKER)
3478 schedule_timeout_uninterruptible(1);
3489 static inline struct page *
3490 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3491 struct alloc_context *ac)
3493 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3494 struct page *page = NULL;
3495 unsigned int alloc_flags;
3496 unsigned long did_some_progress;
3497 enum compact_priority compact_priority = DEF_COMPACT_PRIORITY;
3498 enum compact_result compact_result;
3499 int compaction_retries = 0;
3500 int no_progress_loops = 0;
3501 unsigned long alloc_start = jiffies;
3502 unsigned int stall_timeout = 10 * HZ;
3505 * In the slowpath, we sanity check order to avoid ever trying to
3506 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3507 * be using allocators in order of preference for an area that is
3510 if (order >= MAX_ORDER) {
3511 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3516 * We also sanity check to catch abuse of atomic reserves being used by
3517 * callers that are not in atomic context.
3519 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3520 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3521 gfp_mask &= ~__GFP_ATOMIC;
3524 * The fast path uses conservative alloc_flags to succeed only until
3525 * kswapd needs to be woken up, and to avoid the cost of setting up
3526 * alloc_flags precisely. So we do that now.
3528 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3530 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3531 wake_all_kswapds(order, ac);
3534 * The adjusted alloc_flags might result in immediate success, so try
3537 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3542 * For costly allocations, try direct compaction first, as it's likely
3543 * that we have enough base pages and don't need to reclaim. Don't try
3544 * that for allocations that are allowed to ignore watermarks, as the
3545 * ALLOC_NO_WATERMARKS attempt didn't yet happen.
3547 if (can_direct_reclaim && order > PAGE_ALLOC_COSTLY_ORDER &&
3548 !gfp_pfmemalloc_allowed(gfp_mask)) {
3549 page = __alloc_pages_direct_compact(gfp_mask, order,
3551 INIT_COMPACT_PRIORITY,
3557 * Checks for costly allocations with __GFP_NORETRY, which
3558 * includes THP page fault allocations
3560 if (gfp_mask & __GFP_NORETRY) {
3562 * If compaction is deferred for high-order allocations,
3563 * it is because sync compaction recently failed. If
3564 * this is the case and the caller requested a THP
3565 * allocation, we do not want to heavily disrupt the
3566 * system, so we fail the allocation instead of entering
3569 if (compact_result == COMPACT_DEFERRED)
3573 * Looks like reclaim/compaction is worth trying, but
3574 * sync compaction could be very expensive, so keep
3575 * using async compaction.
3577 compact_priority = INIT_COMPACT_PRIORITY;
3582 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3583 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3584 wake_all_kswapds(order, ac);
3586 if (gfp_pfmemalloc_allowed(gfp_mask))
3587 alloc_flags = ALLOC_NO_WATERMARKS;
3590 * Reset the zonelist iterators if memory policies can be ignored.
3591 * These allocations are high priority and system rather than user
3594 if (!(alloc_flags & ALLOC_CPUSET) || (alloc_flags & ALLOC_NO_WATERMARKS)) {
3595 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3596 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
3597 ac->high_zoneidx, ac->nodemask);
3600 /* Attempt with potentially adjusted zonelist and alloc_flags */
3601 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3605 /* Caller is not willing to reclaim, we can't balance anything */
3606 if (!can_direct_reclaim) {
3608 * All existing users of the __GFP_NOFAIL are blockable, so warn
3609 * of any new users that actually allow this type of allocation
3612 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3616 /* Avoid recursion of direct reclaim */
3617 if (current->flags & PF_MEMALLOC) {
3619 * __GFP_NOFAIL request from this context is rather bizarre
3620 * because we cannot reclaim anything and only can loop waiting
3621 * for somebody to do a work for us.
3623 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3630 /* Avoid allocations with no watermarks from looping endlessly */
3631 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3635 /* Try direct reclaim and then allocating */
3636 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3637 &did_some_progress);
3641 /* Try direct compaction and then allocating */
3642 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3643 compact_priority, &compact_result);
3647 /* Do not loop if specifically requested */
3648 if (gfp_mask & __GFP_NORETRY)
3652 * Do not retry costly high order allocations unless they are
3655 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
3658 /* Make sure we know about allocations which stall for too long */
3659 if (time_after(jiffies, alloc_start + stall_timeout)) {
3660 warn_alloc(gfp_mask,
3661 "page alloction stalls for %ums, order:%u\n",
3662 jiffies_to_msecs(jiffies-alloc_start), order);
3663 stall_timeout += 10 * HZ;
3666 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
3667 did_some_progress > 0, &no_progress_loops))
3671 * It doesn't make any sense to retry for the compaction if the order-0
3672 * reclaim is not able to make any progress because the current
3673 * implementation of the compaction depends on the sufficient amount
3674 * of free memory (see __compaction_suitable)
3676 if (did_some_progress > 0 &&
3677 should_compact_retry(ac, order, alloc_flags,
3678 compact_result, &compact_priority,
3679 &compaction_retries))
3682 /* Reclaim has failed us, start killing things */
3683 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3687 /* Retry as long as the OOM killer is making progress */
3688 if (did_some_progress) {
3689 no_progress_loops = 0;
3694 warn_alloc(gfp_mask,
3695 "page allocation failure: order:%u", order);
3701 * This is the 'heart' of the zoned buddy allocator.
3704 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3705 struct zonelist *zonelist, nodemask_t *nodemask)
3708 unsigned int cpuset_mems_cookie;
3709 unsigned int alloc_flags = ALLOC_WMARK_LOW;
3710 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3711 struct alloc_context ac = {
3712 .high_zoneidx = gfp_zone(gfp_mask),
3713 .zonelist = zonelist,
3714 .nodemask = nodemask,
3715 .migratetype = gfpflags_to_migratetype(gfp_mask),
3718 if (cpusets_enabled()) {
3719 alloc_mask |= __GFP_HARDWALL;
3720 alloc_flags |= ALLOC_CPUSET;
3722 ac.nodemask = &cpuset_current_mems_allowed;
3725 gfp_mask &= gfp_allowed_mask;
3727 lockdep_trace_alloc(gfp_mask);
3729 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3731 if (should_fail_alloc_page(gfp_mask, order))
3735 * Check the zones suitable for the gfp_mask contain at least one
3736 * valid zone. It's possible to have an empty zonelist as a result
3737 * of __GFP_THISNODE and a memoryless node
3739 if (unlikely(!zonelist->_zonerefs->zone))
3742 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3743 alloc_flags |= ALLOC_CMA;
3746 cpuset_mems_cookie = read_mems_allowed_begin();
3748 /* Dirty zone balancing only done in the fast path */
3749 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3752 * The preferred zone is used for statistics but crucially it is
3753 * also used as the starting point for the zonelist iterator. It
3754 * may get reset for allocations that ignore memory policies.
3756 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3757 ac.high_zoneidx, ac.nodemask);
3758 if (!ac.preferred_zoneref) {
3763 /* First allocation attempt */
3764 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3769 * Runtime PM, block IO and its error handling path can deadlock
3770 * because I/O on the device might not complete.
3772 alloc_mask = memalloc_noio_flags(gfp_mask);
3773 ac.spread_dirty_pages = false;
3776 * Restore the original nodemask if it was potentially replaced with
3777 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3779 if (cpusets_enabled())
3780 ac.nodemask = nodemask;
3781 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3785 * When updating a task's mems_allowed, it is possible to race with
3786 * parallel threads in such a way that an allocation can fail while
3787 * the mask is being updated. If a page allocation is about to fail,
3788 * check if the cpuset changed during allocation and if so, retry.
3790 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3791 alloc_mask = gfp_mask;
3796 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
3797 unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
3798 __free_pages(page, order);
3802 if (kmemcheck_enabled && page)
3803 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3805 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3809 EXPORT_SYMBOL(__alloc_pages_nodemask);
3812 * Common helper functions.
3814 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3819 * __get_free_pages() returns a 32-bit address, which cannot represent
3822 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3824 page = alloc_pages(gfp_mask, order);
3827 return (unsigned long) page_address(page);
3829 EXPORT_SYMBOL(__get_free_pages);
3831 unsigned long get_zeroed_page(gfp_t gfp_mask)
3833 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3835 EXPORT_SYMBOL(get_zeroed_page);
3837 void __free_pages(struct page *page, unsigned int order)
3839 if (put_page_testzero(page)) {
3841 free_hot_cold_page(page, false);
3843 __free_pages_ok(page, order);
3847 EXPORT_SYMBOL(__free_pages);
3849 void free_pages(unsigned long addr, unsigned int order)
3852 VM_BUG_ON(!virt_addr_valid((void *)addr));
3853 __free_pages(virt_to_page((void *)addr), order);
3857 EXPORT_SYMBOL(free_pages);
3861 * An arbitrary-length arbitrary-offset area of memory which resides
3862 * within a 0 or higher order page. Multiple fragments within that page
3863 * are individually refcounted, in the page's reference counter.
3865 * The page_frag functions below provide a simple allocation framework for
3866 * page fragments. This is used by the network stack and network device
3867 * drivers to provide a backing region of memory for use as either an
3868 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3870 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3873 struct page *page = NULL;
3874 gfp_t gfp = gfp_mask;
3876 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3877 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3879 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3880 PAGE_FRAG_CACHE_MAX_ORDER);
3881 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3883 if (unlikely(!page))
3884 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3886 nc->va = page ? page_address(page) : NULL;
3891 void *__alloc_page_frag(struct page_frag_cache *nc,
3892 unsigned int fragsz, gfp_t gfp_mask)
3894 unsigned int size = PAGE_SIZE;
3898 if (unlikely(!nc->va)) {
3900 page = __page_frag_refill(nc, gfp_mask);
3904 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3905 /* if size can vary use size else just use PAGE_SIZE */
3908 /* Even if we own the page, we do not use atomic_set().
3909 * This would break get_page_unless_zero() users.
3911 page_ref_add(page, size - 1);
3913 /* reset page count bias and offset to start of new frag */
3914 nc->pfmemalloc = page_is_pfmemalloc(page);
3915 nc->pagecnt_bias = size;
3919 offset = nc->offset - fragsz;
3920 if (unlikely(offset < 0)) {
3921 page = virt_to_page(nc->va);
3923 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3926 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3927 /* if size can vary use size else just use PAGE_SIZE */
3930 /* OK, page count is 0, we can safely set it */
3931 set_page_count(page, size);
3933 /* reset page count bias and offset to start of new frag */
3934 nc->pagecnt_bias = size;
3935 offset = size - fragsz;
3939 nc->offset = offset;
3941 return nc->va + offset;
3943 EXPORT_SYMBOL(__alloc_page_frag);
3946 * Frees a page fragment allocated out of either a compound or order 0 page.
3948 void __free_page_frag(void *addr)
3950 struct page *page = virt_to_head_page(addr);
3952 if (unlikely(put_page_testzero(page)))
3953 __free_pages_ok(page, compound_order(page));
3955 EXPORT_SYMBOL(__free_page_frag);
3957 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3961 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3962 unsigned long used = addr + PAGE_ALIGN(size);
3964 split_page(virt_to_page((void *)addr), order);
3965 while (used < alloc_end) {
3970 return (void *)addr;
3974 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3975 * @size: the number of bytes to allocate
3976 * @gfp_mask: GFP flags for the allocation
3978 * This function is similar to alloc_pages(), except that it allocates the
3979 * minimum number of pages to satisfy the request. alloc_pages() can only
3980 * allocate memory in power-of-two pages.
3982 * This function is also limited by MAX_ORDER.
3984 * Memory allocated by this function must be released by free_pages_exact().
3986 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3988 unsigned int order = get_order(size);
3991 addr = __get_free_pages(gfp_mask, order);
3992 return make_alloc_exact(addr, order, size);
3994 EXPORT_SYMBOL(alloc_pages_exact);
3997 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3999 * @nid: the preferred node ID where memory should be allocated
4000 * @size: the number of bytes to allocate
4001 * @gfp_mask: GFP flags for the allocation
4003 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4006 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4008 unsigned int order = get_order(size);
4009 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4012 return make_alloc_exact((unsigned long)page_address(p), order, size);
4016 * free_pages_exact - release memory allocated via alloc_pages_exact()
4017 * @virt: the value returned by alloc_pages_exact.
4018 * @size: size of allocation, same value as passed to alloc_pages_exact().
4020 * Release the memory allocated by a previous call to alloc_pages_exact.
4022 void free_pages_exact(void *virt, size_t size)
4024 unsigned long addr = (unsigned long)virt;
4025 unsigned long end = addr + PAGE_ALIGN(size);
4027 while (addr < end) {
4032 EXPORT_SYMBOL(free_pages_exact);
4035 * nr_free_zone_pages - count number of pages beyond high watermark
4036 * @offset: The zone index of the highest zone
4038 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4039 * high watermark within all zones at or below a given zone index. For each
4040 * zone, the number of pages is calculated as:
4041 * managed_pages - high_pages
4043 static unsigned long nr_free_zone_pages(int offset)
4048 /* Just pick one node, since fallback list is circular */
4049 unsigned long sum = 0;
4051 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4053 for_each_zone_zonelist(zone, z, zonelist, offset) {
4054 unsigned long size = zone->managed_pages;
4055 unsigned long high = high_wmark_pages(zone);
4064 * nr_free_buffer_pages - count number of pages beyond high watermark
4066 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4067 * watermark within ZONE_DMA and ZONE_NORMAL.
4069 unsigned long nr_free_buffer_pages(void)
4071 return nr_free_zone_pages(gfp_zone(GFP_USER));
4073 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4076 * nr_free_pagecache_pages - count number of pages beyond high watermark
4078 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4079 * high watermark within all zones.
4081 unsigned long nr_free_pagecache_pages(void)
4083 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4086 static inline void show_node(struct zone *zone)
4088 if (IS_ENABLED(CONFIG_NUMA))
4089 printk("Node %d ", zone_to_nid(zone));
4092 long si_mem_available(void)
4095 unsigned long pagecache;
4096 unsigned long wmark_low = 0;
4097 unsigned long pages[NR_LRU_LISTS];
4101 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4102 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
4105 wmark_low += zone->watermark[WMARK_LOW];
4108 * Estimate the amount of memory available for userspace allocations,
4109 * without causing swapping.
4111 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
4114 * Not all the page cache can be freed, otherwise the system will
4115 * start swapping. Assume at least half of the page cache, or the
4116 * low watermark worth of cache, needs to stay.
4118 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4119 pagecache -= min(pagecache / 2, wmark_low);
4120 available += pagecache;
4123 * Part of the reclaimable slab consists of items that are in use,
4124 * and cannot be freed. Cap this estimate at the low watermark.
4126 available += global_page_state(NR_SLAB_RECLAIMABLE) -
4127 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
4133 EXPORT_SYMBOL_GPL(si_mem_available);
4135 void si_meminfo(struct sysinfo *val)
4137 val->totalram = totalram_pages;
4138 val->sharedram = global_node_page_state(NR_SHMEM);
4139 val->freeram = global_page_state(NR_FREE_PAGES);
4140 val->bufferram = nr_blockdev_pages();
4141 val->totalhigh = totalhigh_pages;
4142 val->freehigh = nr_free_highpages();
4143 val->mem_unit = PAGE_SIZE;
4146 EXPORT_SYMBOL(si_meminfo);
4149 void si_meminfo_node(struct sysinfo *val, int nid)
4151 int zone_type; /* needs to be signed */
4152 unsigned long managed_pages = 0;
4153 unsigned long managed_highpages = 0;
4154 unsigned long free_highpages = 0;
4155 pg_data_t *pgdat = NODE_DATA(nid);
4157 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4158 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4159 val->totalram = managed_pages;
4160 val->sharedram = node_page_state(pgdat, NR_SHMEM);
4161 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
4162 #ifdef CONFIG_HIGHMEM
4163 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4164 struct zone *zone = &pgdat->node_zones[zone_type];
4166 if (is_highmem(zone)) {
4167 managed_highpages += zone->managed_pages;
4168 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4171 val->totalhigh = managed_highpages;
4172 val->freehigh = free_highpages;
4174 val->totalhigh = managed_highpages;
4175 val->freehigh = free_highpages;
4177 val->mem_unit = PAGE_SIZE;
4182 * Determine whether the node should be displayed or not, depending on whether
4183 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4185 bool skip_free_areas_node(unsigned int flags, int nid)
4188 unsigned int cpuset_mems_cookie;
4190 if (!(flags & SHOW_MEM_FILTER_NODES))
4194 cpuset_mems_cookie = read_mems_allowed_begin();
4195 ret = !node_isset(nid, cpuset_current_mems_allowed);
4196 } while (read_mems_allowed_retry(cpuset_mems_cookie));
4201 #define K(x) ((x) << (PAGE_SHIFT-10))
4203 static void show_migration_types(unsigned char type)
4205 static const char types[MIGRATE_TYPES] = {
4206 [MIGRATE_UNMOVABLE] = 'U',
4207 [MIGRATE_MOVABLE] = 'M',
4208 [MIGRATE_RECLAIMABLE] = 'E',
4209 [MIGRATE_HIGHATOMIC] = 'H',
4211 [MIGRATE_CMA] = 'C',
4213 #ifdef CONFIG_MEMORY_ISOLATION
4214 [MIGRATE_ISOLATE] = 'I',
4217 char tmp[MIGRATE_TYPES + 1];
4221 for (i = 0; i < MIGRATE_TYPES; i++) {
4222 if (type & (1 << i))
4227 printk("(%s) ", tmp);
4231 * Show free area list (used inside shift_scroll-lock stuff)
4232 * We also calculate the percentage fragmentation. We do this by counting the
4233 * memory on each free list with the exception of the first item on the list.
4236 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4239 void show_free_areas(unsigned int filter)
4241 unsigned long free_pcp = 0;
4246 for_each_populated_zone(zone) {
4247 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4250 for_each_online_cpu(cpu)
4251 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4254 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4255 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4256 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4257 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4258 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4259 " free:%lu free_pcp:%lu free_cma:%lu\n",
4260 global_node_page_state(NR_ACTIVE_ANON),
4261 global_node_page_state(NR_INACTIVE_ANON),
4262 global_node_page_state(NR_ISOLATED_ANON),
4263 global_node_page_state(NR_ACTIVE_FILE),
4264 global_node_page_state(NR_INACTIVE_FILE),
4265 global_node_page_state(NR_ISOLATED_FILE),
4266 global_node_page_state(NR_UNEVICTABLE),
4267 global_node_page_state(NR_FILE_DIRTY),
4268 global_node_page_state(NR_WRITEBACK),
4269 global_node_page_state(NR_UNSTABLE_NFS),
4270 global_page_state(NR_SLAB_RECLAIMABLE),
4271 global_page_state(NR_SLAB_UNRECLAIMABLE),
4272 global_node_page_state(NR_FILE_MAPPED),
4273 global_node_page_state(NR_SHMEM),
4274 global_page_state(NR_PAGETABLE),
4275 global_page_state(NR_BOUNCE),
4276 global_page_state(NR_FREE_PAGES),
4278 global_page_state(NR_FREE_CMA_PAGES));
4280 for_each_online_pgdat(pgdat) {
4282 " active_anon:%lukB"
4283 " inactive_anon:%lukB"
4284 " active_file:%lukB"
4285 " inactive_file:%lukB"
4286 " unevictable:%lukB"
4287 " isolated(anon):%lukB"
4288 " isolated(file):%lukB"
4293 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4295 " shmem_pmdmapped: %lukB"
4298 " writeback_tmp:%lukB"
4300 " pages_scanned:%lu"
4301 " all_unreclaimable? %s"
4304 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
4305 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
4306 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
4307 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
4308 K(node_page_state(pgdat, NR_UNEVICTABLE)),
4309 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
4310 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
4311 K(node_page_state(pgdat, NR_FILE_MAPPED)),
4312 K(node_page_state(pgdat, NR_FILE_DIRTY)),
4313 K(node_page_state(pgdat, NR_WRITEBACK)),
4314 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4315 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
4316 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
4318 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
4320 K(node_page_state(pgdat, NR_SHMEM)),
4321 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
4322 K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
4323 node_page_state(pgdat, NR_PAGES_SCANNED),
4324 !pgdat_reclaimable(pgdat) ? "yes" : "no");
4327 for_each_populated_zone(zone) {
4330 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4334 for_each_online_cpu(cpu)
4335 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4343 " active_anon:%lukB"
4344 " inactive_anon:%lukB"
4345 " active_file:%lukB"
4346 " inactive_file:%lukB"
4347 " unevictable:%lukB"
4348 " writepending:%lukB"
4352 " slab_reclaimable:%lukB"
4353 " slab_unreclaimable:%lukB"
4354 " kernel_stack:%lukB"
4362 K(zone_page_state(zone, NR_FREE_PAGES)),
4363 K(min_wmark_pages(zone)),
4364 K(low_wmark_pages(zone)),
4365 K(high_wmark_pages(zone)),
4366 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
4367 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
4368 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
4369 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
4370 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
4371 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
4372 K(zone->present_pages),
4373 K(zone->managed_pages),
4374 K(zone_page_state(zone, NR_MLOCK)),
4375 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4376 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4377 zone_page_state(zone, NR_KERNEL_STACK_KB),
4378 K(zone_page_state(zone, NR_PAGETABLE)),
4379 K(zone_page_state(zone, NR_BOUNCE)),
4381 K(this_cpu_read(zone->pageset->pcp.count)),
4382 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
4383 printk("lowmem_reserve[]:");
4384 for (i = 0; i < MAX_NR_ZONES; i++)
4385 printk(" %ld", zone->lowmem_reserve[i]);
4389 for_each_populated_zone(zone) {
4391 unsigned long nr[MAX_ORDER], flags, total = 0;
4392 unsigned char types[MAX_ORDER];
4394 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4397 printk("%s: ", zone->name);
4399 spin_lock_irqsave(&zone->lock, flags);
4400 for (order = 0; order < MAX_ORDER; order++) {
4401 struct free_area *area = &zone->free_area[order];
4404 nr[order] = area->nr_free;
4405 total += nr[order] << order;
4408 for (type = 0; type < MIGRATE_TYPES; type++) {
4409 if (!list_empty(&area->free_list[type]))
4410 types[order] |= 1 << type;
4413 spin_unlock_irqrestore(&zone->lock, flags);
4414 for (order = 0; order < MAX_ORDER; order++) {
4415 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4417 show_migration_types(types[order]);
4419 printk("= %lukB\n", K(total));
4422 hugetlb_show_meminfo();
4424 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
4426 show_swap_cache_info();
4429 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4431 zoneref->zone = zone;
4432 zoneref->zone_idx = zone_idx(zone);
4436 * Builds allocation fallback zone lists.
4438 * Add all populated zones of a node to the zonelist.
4440 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4444 enum zone_type zone_type = MAX_NR_ZONES;
4448 zone = pgdat->node_zones + zone_type;
4449 if (managed_zone(zone)) {
4450 zoneref_set_zone(zone,
4451 &zonelist->_zonerefs[nr_zones++]);
4452 check_highest_zone(zone_type);
4454 } while (zone_type);
4462 * 0 = automatic detection of better ordering.
4463 * 1 = order by ([node] distance, -zonetype)
4464 * 2 = order by (-zonetype, [node] distance)
4466 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4467 * the same zonelist. So only NUMA can configure this param.
4469 #define ZONELIST_ORDER_DEFAULT 0
4470 #define ZONELIST_ORDER_NODE 1
4471 #define ZONELIST_ORDER_ZONE 2
4473 /* zonelist order in the kernel.
4474 * set_zonelist_order() will set this to NODE or ZONE.
4476 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4477 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4481 /* The value user specified ....changed by config */
4482 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4483 /* string for sysctl */
4484 #define NUMA_ZONELIST_ORDER_LEN 16
4485 char numa_zonelist_order[16] = "default";
4488 * interface for configure zonelist ordering.
4489 * command line option "numa_zonelist_order"
4490 * = "[dD]efault - default, automatic configuration.
4491 * = "[nN]ode - order by node locality, then by zone within node
4492 * = "[zZ]one - order by zone, then by locality within zone
4495 static int __parse_numa_zonelist_order(char *s)
4497 if (*s == 'd' || *s == 'D') {
4498 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4499 } else if (*s == 'n' || *s == 'N') {
4500 user_zonelist_order = ZONELIST_ORDER_NODE;
4501 } else if (*s == 'z' || *s == 'Z') {
4502 user_zonelist_order = ZONELIST_ORDER_ZONE;
4504 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4510 static __init int setup_numa_zonelist_order(char *s)
4517 ret = __parse_numa_zonelist_order(s);
4519 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4523 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4526 * sysctl handler for numa_zonelist_order
4528 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4529 void __user *buffer, size_t *length,
4532 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4534 static DEFINE_MUTEX(zl_order_mutex);
4536 mutex_lock(&zl_order_mutex);
4538 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4542 strcpy(saved_string, (char *)table->data);
4544 ret = proc_dostring(table, write, buffer, length, ppos);
4548 int oldval = user_zonelist_order;
4550 ret = __parse_numa_zonelist_order((char *)table->data);
4553 * bogus value. restore saved string
4555 strncpy((char *)table->data, saved_string,
4556 NUMA_ZONELIST_ORDER_LEN);
4557 user_zonelist_order = oldval;
4558 } else if (oldval != user_zonelist_order) {
4559 mutex_lock(&zonelists_mutex);
4560 build_all_zonelists(NULL, NULL);
4561 mutex_unlock(&zonelists_mutex);
4565 mutex_unlock(&zl_order_mutex);
4570 #define MAX_NODE_LOAD (nr_online_nodes)
4571 static int node_load[MAX_NUMNODES];
4574 * find_next_best_node - find the next node that should appear in a given node's fallback list
4575 * @node: node whose fallback list we're appending
4576 * @used_node_mask: nodemask_t of already used nodes
4578 * We use a number of factors to determine which is the next node that should
4579 * appear on a given node's fallback list. The node should not have appeared
4580 * already in @node's fallback list, and it should be the next closest node
4581 * according to the distance array (which contains arbitrary distance values
4582 * from each node to each node in the system), and should also prefer nodes
4583 * with no CPUs, since presumably they'll have very little allocation pressure
4584 * on them otherwise.
4585 * It returns -1 if no node is found.
4587 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4590 int min_val = INT_MAX;
4591 int best_node = NUMA_NO_NODE;
4592 const struct cpumask *tmp = cpumask_of_node(0);
4594 /* Use the local node if we haven't already */
4595 if (!node_isset(node, *used_node_mask)) {
4596 node_set(node, *used_node_mask);
4600 for_each_node_state(n, N_MEMORY) {
4602 /* Don't want a node to appear more than once */
4603 if (node_isset(n, *used_node_mask))
4606 /* Use the distance array to find the distance */
4607 val = node_distance(node, n);
4609 /* Penalize nodes under us ("prefer the next node") */
4612 /* Give preference to headless and unused nodes */
4613 tmp = cpumask_of_node(n);
4614 if (!cpumask_empty(tmp))
4615 val += PENALTY_FOR_NODE_WITH_CPUS;
4617 /* Slight preference for less loaded node */
4618 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4619 val += node_load[n];
4621 if (val < min_val) {
4628 node_set(best_node, *used_node_mask);
4635 * Build zonelists ordered by node and zones within node.
4636 * This results in maximum locality--normal zone overflows into local
4637 * DMA zone, if any--but risks exhausting DMA zone.
4639 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4642 struct zonelist *zonelist;
4644 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4645 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4647 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4648 zonelist->_zonerefs[j].zone = NULL;
4649 zonelist->_zonerefs[j].zone_idx = 0;
4653 * Build gfp_thisnode zonelists
4655 static void build_thisnode_zonelists(pg_data_t *pgdat)
4658 struct zonelist *zonelist;
4660 zonelist = &pgdat->node_zonelists[ZONELIST_NOFALLBACK];
4661 j = build_zonelists_node(pgdat, zonelist, 0);
4662 zonelist->_zonerefs[j].zone = NULL;
4663 zonelist->_zonerefs[j].zone_idx = 0;
4667 * Build zonelists ordered by zone and nodes within zones.
4668 * This results in conserving DMA zone[s] until all Normal memory is
4669 * exhausted, but results in overflowing to remote node while memory
4670 * may still exist in local DMA zone.
4672 static int node_order[MAX_NUMNODES];
4674 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4677 int zone_type; /* needs to be signed */
4679 struct zonelist *zonelist;
4681 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4683 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4684 for (j = 0; j < nr_nodes; j++) {
4685 node = node_order[j];
4686 z = &NODE_DATA(node)->node_zones[zone_type];
4687 if (managed_zone(z)) {
4689 &zonelist->_zonerefs[pos++]);
4690 check_highest_zone(zone_type);
4694 zonelist->_zonerefs[pos].zone = NULL;
4695 zonelist->_zonerefs[pos].zone_idx = 0;
4698 #if defined(CONFIG_64BIT)
4700 * Devices that require DMA32/DMA are relatively rare and do not justify a
4701 * penalty to every machine in case the specialised case applies. Default
4702 * to Node-ordering on 64-bit NUMA machines
4704 static int default_zonelist_order(void)
4706 return ZONELIST_ORDER_NODE;
4710 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4711 * by the kernel. If processes running on node 0 deplete the low memory zone
4712 * then reclaim will occur more frequency increasing stalls and potentially
4713 * be easier to OOM if a large percentage of the zone is under writeback or
4714 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4715 * Hence, default to zone ordering on 32-bit.
4717 static int default_zonelist_order(void)
4719 return ZONELIST_ORDER_ZONE;
4721 #endif /* CONFIG_64BIT */
4723 static void set_zonelist_order(void)
4725 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4726 current_zonelist_order = default_zonelist_order();
4728 current_zonelist_order = user_zonelist_order;
4731 static void build_zonelists(pg_data_t *pgdat)
4734 nodemask_t used_mask;
4735 int local_node, prev_node;
4736 struct zonelist *zonelist;
4737 unsigned int order = current_zonelist_order;
4739 /* initialize zonelists */
4740 for (i = 0; i < MAX_ZONELISTS; i++) {
4741 zonelist = pgdat->node_zonelists + i;
4742 zonelist->_zonerefs[0].zone = NULL;
4743 zonelist->_zonerefs[0].zone_idx = 0;
4746 /* NUMA-aware ordering of nodes */
4747 local_node = pgdat->node_id;
4748 load = nr_online_nodes;
4749 prev_node = local_node;
4750 nodes_clear(used_mask);
4752 memset(node_order, 0, sizeof(node_order));
4755 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4757 * We don't want to pressure a particular node.
4758 * So adding penalty to the first node in same
4759 * distance group to make it round-robin.
4761 if (node_distance(local_node, node) !=
4762 node_distance(local_node, prev_node))
4763 node_load[node] = load;
4767 if (order == ZONELIST_ORDER_NODE)
4768 build_zonelists_in_node_order(pgdat, node);
4770 node_order[i++] = node; /* remember order */
4773 if (order == ZONELIST_ORDER_ZONE) {
4774 /* calculate node order -- i.e., DMA last! */
4775 build_zonelists_in_zone_order(pgdat, i);
4778 build_thisnode_zonelists(pgdat);
4781 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4783 * Return node id of node used for "local" allocations.
4784 * I.e., first node id of first zone in arg node's generic zonelist.
4785 * Used for initializing percpu 'numa_mem', which is used primarily
4786 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4788 int local_memory_node(int node)
4792 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4793 gfp_zone(GFP_KERNEL),
4795 return z->zone->node;
4799 static void setup_min_unmapped_ratio(void);
4800 static void setup_min_slab_ratio(void);
4801 #else /* CONFIG_NUMA */
4803 static void set_zonelist_order(void)
4805 current_zonelist_order = ZONELIST_ORDER_ZONE;
4808 static void build_zonelists(pg_data_t *pgdat)
4810 int node, local_node;
4812 struct zonelist *zonelist;
4814 local_node = pgdat->node_id;
4816 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4817 j = build_zonelists_node(pgdat, zonelist, 0);
4820 * Now we build the zonelist so that it contains the zones
4821 * of all the other nodes.
4822 * We don't want to pressure a particular node, so when
4823 * building the zones for node N, we make sure that the
4824 * zones coming right after the local ones are those from
4825 * node N+1 (modulo N)
4827 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4828 if (!node_online(node))
4830 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4832 for (node = 0; node < local_node; node++) {
4833 if (!node_online(node))
4835 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4838 zonelist->_zonerefs[j].zone = NULL;
4839 zonelist->_zonerefs[j].zone_idx = 0;
4842 #endif /* CONFIG_NUMA */
4845 * Boot pageset table. One per cpu which is going to be used for all
4846 * zones and all nodes. The parameters will be set in such a way
4847 * that an item put on a list will immediately be handed over to
4848 * the buddy list. This is safe since pageset manipulation is done
4849 * with interrupts disabled.
4851 * The boot_pagesets must be kept even after bootup is complete for
4852 * unused processors and/or zones. They do play a role for bootstrapping
4853 * hotplugged processors.
4855 * zoneinfo_show() and maybe other functions do
4856 * not check if the processor is online before following the pageset pointer.
4857 * Other parts of the kernel may not check if the zone is available.
4859 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4860 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4861 static void setup_zone_pageset(struct zone *zone);
4864 * Global mutex to protect against size modification of zonelists
4865 * as well as to serialize pageset setup for the new populated zone.
4867 DEFINE_MUTEX(zonelists_mutex);
4869 /* return values int ....just for stop_machine() */
4870 static int __build_all_zonelists(void *data)
4874 pg_data_t *self = data;
4877 memset(node_load, 0, sizeof(node_load));
4880 if (self && !node_online(self->node_id)) {
4881 build_zonelists(self);
4884 for_each_online_node(nid) {
4885 pg_data_t *pgdat = NODE_DATA(nid);
4887 build_zonelists(pgdat);
4891 * Initialize the boot_pagesets that are going to be used
4892 * for bootstrapping processors. The real pagesets for
4893 * each zone will be allocated later when the per cpu
4894 * allocator is available.
4896 * boot_pagesets are used also for bootstrapping offline
4897 * cpus if the system is already booted because the pagesets
4898 * are needed to initialize allocators on a specific cpu too.
4899 * F.e. the percpu allocator needs the page allocator which
4900 * needs the percpu allocator in order to allocate its pagesets
4901 * (a chicken-egg dilemma).
4903 for_each_possible_cpu(cpu) {
4904 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4906 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4908 * We now know the "local memory node" for each node--
4909 * i.e., the node of the first zone in the generic zonelist.
4910 * Set up numa_mem percpu variable for on-line cpus. During
4911 * boot, only the boot cpu should be on-line; we'll init the
4912 * secondary cpus' numa_mem as they come on-line. During
4913 * node/memory hotplug, we'll fixup all on-line cpus.
4915 if (cpu_online(cpu))
4916 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4923 static noinline void __init
4924 build_all_zonelists_init(void)
4926 __build_all_zonelists(NULL);
4927 mminit_verify_zonelist();
4928 cpuset_init_current_mems_allowed();
4932 * Called with zonelists_mutex held always
4933 * unless system_state == SYSTEM_BOOTING.
4935 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4936 * [we're only called with non-NULL zone through __meminit paths] and
4937 * (2) call of __init annotated helper build_all_zonelists_init
4938 * [protected by SYSTEM_BOOTING].
4940 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4942 set_zonelist_order();
4944 if (system_state == SYSTEM_BOOTING) {
4945 build_all_zonelists_init();
4947 #ifdef CONFIG_MEMORY_HOTPLUG
4949 setup_zone_pageset(zone);
4951 /* we have to stop all cpus to guarantee there is no user
4953 stop_machine(__build_all_zonelists, pgdat, NULL);
4954 /* cpuset refresh routine should be here */
4956 vm_total_pages = nr_free_pagecache_pages();
4958 * Disable grouping by mobility if the number of pages in the
4959 * system is too low to allow the mechanism to work. It would be
4960 * more accurate, but expensive to check per-zone. This check is
4961 * made on memory-hotadd so a system can start with mobility
4962 * disabled and enable it later
4964 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4965 page_group_by_mobility_disabled = 1;
4967 page_group_by_mobility_disabled = 0;
4969 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4971 zonelist_order_name[current_zonelist_order],
4972 page_group_by_mobility_disabled ? "off" : "on",
4975 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4980 * Helper functions to size the waitqueue hash table.
4981 * Essentially these want to choose hash table sizes sufficiently
4982 * large so that collisions trying to wait on pages are rare.
4983 * But in fact, the number of active page waitqueues on typical
4984 * systems is ridiculously low, less than 200. So this is even
4985 * conservative, even though it seems large.
4987 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4988 * waitqueues, i.e. the size of the waitq table given the number of pages.
4990 #define PAGES_PER_WAITQUEUE 256
4992 #ifndef CONFIG_MEMORY_HOTPLUG
4993 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4995 unsigned long size = 1;
4997 pages /= PAGES_PER_WAITQUEUE;
4999 while (size < pages)
5003 * Once we have dozens or even hundreds of threads sleeping
5004 * on IO we've got bigger problems than wait queue collision.
5005 * Limit the size of the wait table to a reasonable size.
5007 size = min(size, 4096UL);
5009 return max(size, 4UL);
5013 * A zone's size might be changed by hot-add, so it is not possible to determine
5014 * a suitable size for its wait_table. So we use the maximum size now.
5016 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5018 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5019 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5020 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5022 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5023 * or more by the traditional way. (See above). It equals:
5025 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5026 * ia64(16K page size) : = ( 8G + 4M)byte.
5027 * powerpc (64K page size) : = (32G +16M)byte.
5029 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
5036 * This is an integer logarithm so that shifts can be used later
5037 * to extract the more random high bits from the multiplicative
5038 * hash function before the remainder is taken.
5040 static inline unsigned long wait_table_bits(unsigned long size)
5046 * Initially all pages are reserved - free ones are freed
5047 * up by free_all_bootmem() once the early boot process is
5048 * done. Non-atomic initialization, single-pass.
5050 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5051 unsigned long start_pfn, enum memmap_context context)
5053 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
5054 unsigned long end_pfn = start_pfn + size;
5055 pg_data_t *pgdat = NODE_DATA(nid);
5057 unsigned long nr_initialised = 0;
5058 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5059 struct memblock_region *r = NULL, *tmp;
5062 if (highest_memmap_pfn < end_pfn - 1)
5063 highest_memmap_pfn = end_pfn - 1;
5066 * Honor reservation requested by the driver for this ZONE_DEVICE
5069 if (altmap && start_pfn == altmap->base_pfn)
5070 start_pfn += altmap->reserve;
5072 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5074 * There can be holes in boot-time mem_map[]s handed to this
5075 * function. They do not exist on hotplugged memory.
5077 if (context != MEMMAP_EARLY)
5080 if (!early_pfn_valid(pfn))
5082 if (!early_pfn_in_nid(pfn, nid))
5084 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5087 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5089 * Check given memblock attribute by firmware which can affect
5090 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5091 * mirrored, it's an overlapped memmap init. skip it.
5093 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5094 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5095 for_each_memblock(memory, tmp)
5096 if (pfn < memblock_region_memory_end_pfn(tmp))
5100 if (pfn >= memblock_region_memory_base_pfn(r) &&
5101 memblock_is_mirror(r)) {
5102 /* already initialized as NORMAL */
5103 pfn = memblock_region_memory_end_pfn(r);
5111 * Mark the block movable so that blocks are reserved for
5112 * movable at startup. This will force kernel allocations
5113 * to reserve their blocks rather than leaking throughout
5114 * the address space during boot when many long-lived
5115 * kernel allocations are made.
5117 * bitmap is created for zone's valid pfn range. but memmap
5118 * can be created for invalid pages (for alignment)
5119 * check here not to call set_pageblock_migratetype() against
5122 if (!(pfn & (pageblock_nr_pages - 1))) {
5123 struct page *page = pfn_to_page(pfn);
5125 __init_single_page(page, pfn, zone, nid);
5126 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5128 __init_single_pfn(pfn, zone, nid);
5133 static void __meminit zone_init_free_lists(struct zone *zone)
5135 unsigned int order, t;
5136 for_each_migratetype_order(order, t) {
5137 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5138 zone->free_area[order].nr_free = 0;
5142 #ifndef __HAVE_ARCH_MEMMAP_INIT
5143 #define memmap_init(size, nid, zone, start_pfn) \
5144 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5147 static int zone_batchsize(struct zone *zone)
5153 * The per-cpu-pages pools are set to around 1000th of the
5154 * size of the zone. But no more than 1/2 of a meg.
5156 * OK, so we don't know how big the cache is. So guess.
5158 batch = zone->managed_pages / 1024;
5159 if (batch * PAGE_SIZE > 512 * 1024)
5160 batch = (512 * 1024) / PAGE_SIZE;
5161 batch /= 4; /* We effectively *= 4 below */
5166 * Clamp the batch to a 2^n - 1 value. Having a power
5167 * of 2 value was found to be more likely to have
5168 * suboptimal cache aliasing properties in some cases.
5170 * For example if 2 tasks are alternately allocating
5171 * batches of pages, one task can end up with a lot
5172 * of pages of one half of the possible page colors
5173 * and the other with pages of the other colors.
5175 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5180 /* The deferral and batching of frees should be suppressed under NOMMU
5183 * The problem is that NOMMU needs to be able to allocate large chunks
5184 * of contiguous memory as there's no hardware page translation to
5185 * assemble apparent contiguous memory from discontiguous pages.
5187 * Queueing large contiguous runs of pages for batching, however,
5188 * causes the pages to actually be freed in smaller chunks. As there
5189 * can be a significant delay between the individual batches being
5190 * recycled, this leads to the once large chunks of space being
5191 * fragmented and becoming unavailable for high-order allocations.
5198 * pcp->high and pcp->batch values are related and dependent on one another:
5199 * ->batch must never be higher then ->high.
5200 * The following function updates them in a safe manner without read side
5203 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5204 * those fields changing asynchronously (acording the the above rule).
5206 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5207 * outside of boot time (or some other assurance that no concurrent updaters
5210 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5211 unsigned long batch)
5213 /* start with a fail safe value for batch */
5217 /* Update high, then batch, in order */
5224 /* a companion to pageset_set_high() */
5225 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5227 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5230 static void pageset_init(struct per_cpu_pageset *p)
5232 struct per_cpu_pages *pcp;
5235 memset(p, 0, sizeof(*p));
5239 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5240 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5243 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5246 pageset_set_batch(p, batch);
5250 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5251 * to the value high for the pageset p.
5253 static void pageset_set_high(struct per_cpu_pageset *p,
5256 unsigned long batch = max(1UL, high / 4);
5257 if ((high / 4) > (PAGE_SHIFT * 8))
5258 batch = PAGE_SHIFT * 8;
5260 pageset_update(&p->pcp, high, batch);
5263 static void pageset_set_high_and_batch(struct zone *zone,
5264 struct per_cpu_pageset *pcp)
5266 if (percpu_pagelist_fraction)
5267 pageset_set_high(pcp,
5268 (zone->managed_pages /
5269 percpu_pagelist_fraction));
5271 pageset_set_batch(pcp, zone_batchsize(zone));
5274 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5276 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5279 pageset_set_high_and_batch(zone, pcp);
5282 static void __meminit setup_zone_pageset(struct zone *zone)
5285 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5286 for_each_possible_cpu(cpu)
5287 zone_pageset_init(zone, cpu);
5291 * Allocate per cpu pagesets and initialize them.
5292 * Before this call only boot pagesets were available.
5294 void __init setup_per_cpu_pageset(void)
5296 struct pglist_data *pgdat;
5299 for_each_populated_zone(zone)
5300 setup_zone_pageset(zone);
5302 for_each_online_pgdat(pgdat)
5303 pgdat->per_cpu_nodestats =
5304 alloc_percpu(struct per_cpu_nodestat);
5307 static noinline __ref
5308 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
5314 * The per-page waitqueue mechanism uses hashed waitqueues
5317 zone->wait_table_hash_nr_entries =
5318 wait_table_hash_nr_entries(zone_size_pages);
5319 zone->wait_table_bits =
5320 wait_table_bits(zone->wait_table_hash_nr_entries);
5321 alloc_size = zone->wait_table_hash_nr_entries
5322 * sizeof(wait_queue_head_t);
5324 if (!slab_is_available()) {
5325 zone->wait_table = (wait_queue_head_t *)
5326 memblock_virt_alloc_node_nopanic(
5327 alloc_size, zone->zone_pgdat->node_id);
5330 * This case means that a zone whose size was 0 gets new memory
5331 * via memory hot-add.
5332 * But it may be the case that a new node was hot-added. In
5333 * this case vmalloc() will not be able to use this new node's
5334 * memory - this wait_table must be initialized to use this new
5335 * node itself as well.
5336 * To use this new node's memory, further consideration will be
5339 zone->wait_table = vmalloc(alloc_size);
5341 if (!zone->wait_table)
5344 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
5345 init_waitqueue_head(zone->wait_table + i);
5350 static __meminit void zone_pcp_init(struct zone *zone)
5353 * per cpu subsystem is not up at this point. The following code
5354 * relies on the ability of the linker to provide the
5355 * offset of a (static) per cpu variable into the per cpu area.
5357 zone->pageset = &boot_pageset;
5359 if (populated_zone(zone))
5360 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5361 zone->name, zone->present_pages,
5362 zone_batchsize(zone));
5365 int __meminit init_currently_empty_zone(struct zone *zone,
5366 unsigned long zone_start_pfn,
5369 struct pglist_data *pgdat = zone->zone_pgdat;
5371 ret = zone_wait_table_init(zone, size);
5374 pgdat->nr_zones = zone_idx(zone) + 1;
5376 zone->zone_start_pfn = zone_start_pfn;
5378 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5379 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5381 (unsigned long)zone_idx(zone),
5382 zone_start_pfn, (zone_start_pfn + size));
5384 zone_init_free_lists(zone);
5389 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5390 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5393 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5395 int __meminit __early_pfn_to_nid(unsigned long pfn,
5396 struct mminit_pfnnid_cache *state)
5398 unsigned long start_pfn, end_pfn;
5401 if (state->last_start <= pfn && pfn < state->last_end)
5402 return state->last_nid;
5404 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5406 state->last_start = start_pfn;
5407 state->last_end = end_pfn;
5408 state->last_nid = nid;
5413 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5416 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5417 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5418 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5420 * If an architecture guarantees that all ranges registered contain no holes
5421 * and may be freed, this this function may be used instead of calling
5422 * memblock_free_early_nid() manually.
5424 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5426 unsigned long start_pfn, end_pfn;
5429 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5430 start_pfn = min(start_pfn, max_low_pfn);
5431 end_pfn = min(end_pfn, max_low_pfn);
5433 if (start_pfn < end_pfn)
5434 memblock_free_early_nid(PFN_PHYS(start_pfn),
5435 (end_pfn - start_pfn) << PAGE_SHIFT,
5441 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5442 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5444 * If an architecture guarantees that all ranges registered contain no holes and may
5445 * be freed, this function may be used instead of calling memory_present() manually.
5447 void __init sparse_memory_present_with_active_regions(int nid)
5449 unsigned long start_pfn, end_pfn;
5452 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5453 memory_present(this_nid, start_pfn, end_pfn);
5457 * get_pfn_range_for_nid - Return the start and end page frames for a node
5458 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5459 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5460 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5462 * It returns the start and end page frame of a node based on information
5463 * provided by memblock_set_node(). If called for a node
5464 * with no available memory, a warning is printed and the start and end
5467 void __meminit get_pfn_range_for_nid(unsigned int nid,
5468 unsigned long *start_pfn, unsigned long *end_pfn)
5470 unsigned long this_start_pfn, this_end_pfn;
5476 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5477 *start_pfn = min(*start_pfn, this_start_pfn);
5478 *end_pfn = max(*end_pfn, this_end_pfn);
5481 if (*start_pfn == -1UL)
5486 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5487 * assumption is made that zones within a node are ordered in monotonic
5488 * increasing memory addresses so that the "highest" populated zone is used
5490 static void __init find_usable_zone_for_movable(void)
5493 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5494 if (zone_index == ZONE_MOVABLE)
5497 if (arch_zone_highest_possible_pfn[zone_index] >
5498 arch_zone_lowest_possible_pfn[zone_index])
5502 VM_BUG_ON(zone_index == -1);
5503 movable_zone = zone_index;
5507 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5508 * because it is sized independent of architecture. Unlike the other zones,
5509 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5510 * in each node depending on the size of each node and how evenly kernelcore
5511 * is distributed. This helper function adjusts the zone ranges
5512 * provided by the architecture for a given node by using the end of the
5513 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5514 * zones within a node are in order of monotonic increases memory addresses
5516 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5517 unsigned long zone_type,
5518 unsigned long node_start_pfn,
5519 unsigned long node_end_pfn,
5520 unsigned long *zone_start_pfn,
5521 unsigned long *zone_end_pfn)
5523 /* Only adjust if ZONE_MOVABLE is on this node */
5524 if (zone_movable_pfn[nid]) {
5525 /* Size ZONE_MOVABLE */
5526 if (zone_type == ZONE_MOVABLE) {
5527 *zone_start_pfn = zone_movable_pfn[nid];
5528 *zone_end_pfn = min(node_end_pfn,
5529 arch_zone_highest_possible_pfn[movable_zone]);
5531 /* Adjust for ZONE_MOVABLE starting within this range */
5532 } else if (!mirrored_kernelcore &&
5533 *zone_start_pfn < zone_movable_pfn[nid] &&
5534 *zone_end_pfn > zone_movable_pfn[nid]) {
5535 *zone_end_pfn = zone_movable_pfn[nid];
5537 /* Check if this whole range is within ZONE_MOVABLE */
5538 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5539 *zone_start_pfn = *zone_end_pfn;
5544 * Return the number of pages a zone spans in a node, including holes
5545 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5547 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5548 unsigned long zone_type,
5549 unsigned long node_start_pfn,
5550 unsigned long node_end_pfn,
5551 unsigned long *zone_start_pfn,
5552 unsigned long *zone_end_pfn,
5553 unsigned long *ignored)
5555 /* When hotadd a new node from cpu_up(), the node should be empty */
5556 if (!node_start_pfn && !node_end_pfn)
5559 /* Get the start and end of the zone */
5560 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5561 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5562 adjust_zone_range_for_zone_movable(nid, zone_type,
5563 node_start_pfn, node_end_pfn,
5564 zone_start_pfn, zone_end_pfn);
5566 /* Check that this node has pages within the zone's required range */
5567 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5570 /* Move the zone boundaries inside the node if necessary */
5571 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5572 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5574 /* Return the spanned pages */
5575 return *zone_end_pfn - *zone_start_pfn;
5579 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5580 * then all holes in the requested range will be accounted for.
5582 unsigned long __meminit __absent_pages_in_range(int nid,
5583 unsigned long range_start_pfn,
5584 unsigned long range_end_pfn)
5586 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5587 unsigned long start_pfn, end_pfn;
5590 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5591 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5592 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5593 nr_absent -= end_pfn - start_pfn;
5599 * absent_pages_in_range - Return number of page frames in holes within a range
5600 * @start_pfn: The start PFN to start searching for holes
5601 * @end_pfn: The end PFN to stop searching for holes
5603 * It returns the number of pages frames in memory holes within a range.
5605 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5606 unsigned long end_pfn)
5608 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5611 /* Return the number of page frames in holes in a zone on a node */
5612 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5613 unsigned long zone_type,
5614 unsigned long node_start_pfn,
5615 unsigned long node_end_pfn,
5616 unsigned long *ignored)
5618 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5619 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5620 unsigned long zone_start_pfn, zone_end_pfn;
5621 unsigned long nr_absent;
5623 /* When hotadd a new node from cpu_up(), the node should be empty */
5624 if (!node_start_pfn && !node_end_pfn)
5627 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5628 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5630 adjust_zone_range_for_zone_movable(nid, zone_type,
5631 node_start_pfn, node_end_pfn,
5632 &zone_start_pfn, &zone_end_pfn);
5633 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5636 * ZONE_MOVABLE handling.
5637 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5640 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
5641 unsigned long start_pfn, end_pfn;
5642 struct memblock_region *r;
5644 for_each_memblock(memory, r) {
5645 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5646 zone_start_pfn, zone_end_pfn);
5647 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5648 zone_start_pfn, zone_end_pfn);
5650 if (zone_type == ZONE_MOVABLE &&
5651 memblock_is_mirror(r))
5652 nr_absent += end_pfn - start_pfn;
5654 if (zone_type == ZONE_NORMAL &&
5655 !memblock_is_mirror(r))
5656 nr_absent += end_pfn - start_pfn;
5663 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5664 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5665 unsigned long zone_type,
5666 unsigned long node_start_pfn,
5667 unsigned long node_end_pfn,
5668 unsigned long *zone_start_pfn,
5669 unsigned long *zone_end_pfn,
5670 unsigned long *zones_size)
5674 *zone_start_pfn = node_start_pfn;
5675 for (zone = 0; zone < zone_type; zone++)
5676 *zone_start_pfn += zones_size[zone];
5678 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5680 return zones_size[zone_type];
5683 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5684 unsigned long zone_type,
5685 unsigned long node_start_pfn,
5686 unsigned long node_end_pfn,
5687 unsigned long *zholes_size)
5692 return zholes_size[zone_type];
5695 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5697 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5698 unsigned long node_start_pfn,
5699 unsigned long node_end_pfn,
5700 unsigned long *zones_size,
5701 unsigned long *zholes_size)
5703 unsigned long realtotalpages = 0, totalpages = 0;
5706 for (i = 0; i < MAX_NR_ZONES; i++) {
5707 struct zone *zone = pgdat->node_zones + i;
5708 unsigned long zone_start_pfn, zone_end_pfn;
5709 unsigned long size, real_size;
5711 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5717 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5718 node_start_pfn, node_end_pfn,
5721 zone->zone_start_pfn = zone_start_pfn;
5723 zone->zone_start_pfn = 0;
5724 zone->spanned_pages = size;
5725 zone->present_pages = real_size;
5728 realtotalpages += real_size;
5731 pgdat->node_spanned_pages = totalpages;
5732 pgdat->node_present_pages = realtotalpages;
5733 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5737 #ifndef CONFIG_SPARSEMEM
5739 * Calculate the size of the zone->blockflags rounded to an unsigned long
5740 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5741 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5742 * round what is now in bits to nearest long in bits, then return it in
5745 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5747 unsigned long usemapsize;
5749 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5750 usemapsize = roundup(zonesize, pageblock_nr_pages);
5751 usemapsize = usemapsize >> pageblock_order;
5752 usemapsize *= NR_PAGEBLOCK_BITS;
5753 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5755 return usemapsize / 8;
5758 static void __init setup_usemap(struct pglist_data *pgdat,
5760 unsigned long zone_start_pfn,
5761 unsigned long zonesize)
5763 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5764 zone->pageblock_flags = NULL;
5766 zone->pageblock_flags =
5767 memblock_virt_alloc_node_nopanic(usemapsize,
5771 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5772 unsigned long zone_start_pfn, unsigned long zonesize) {}
5773 #endif /* CONFIG_SPARSEMEM */
5775 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5777 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5778 void __paginginit set_pageblock_order(void)
5782 /* Check that pageblock_nr_pages has not already been setup */
5783 if (pageblock_order)
5786 if (HPAGE_SHIFT > PAGE_SHIFT)
5787 order = HUGETLB_PAGE_ORDER;
5789 order = MAX_ORDER - 1;
5792 * Assume the largest contiguous order of interest is a huge page.
5793 * This value may be variable depending on boot parameters on IA64 and
5796 pageblock_order = order;
5798 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5801 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5802 * is unused as pageblock_order is set at compile-time. See
5803 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5806 void __paginginit set_pageblock_order(void)
5810 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5812 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5813 unsigned long present_pages)
5815 unsigned long pages = spanned_pages;
5818 * Provide a more accurate estimation if there are holes within
5819 * the zone and SPARSEMEM is in use. If there are holes within the
5820 * zone, each populated memory region may cost us one or two extra
5821 * memmap pages due to alignment because memmap pages for each
5822 * populated regions may not naturally algined on page boundary.
5823 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5825 if (spanned_pages > present_pages + (present_pages >> 4) &&
5826 IS_ENABLED(CONFIG_SPARSEMEM))
5827 pages = present_pages;
5829 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5833 * Set up the zone data structures:
5834 * - mark all pages reserved
5835 * - mark all memory queues empty
5836 * - clear the memory bitmaps
5838 * NOTE: pgdat should get zeroed by caller.
5840 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5843 int nid = pgdat->node_id;
5846 pgdat_resize_init(pgdat);
5847 #ifdef CONFIG_NUMA_BALANCING
5848 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5849 pgdat->numabalancing_migrate_nr_pages = 0;
5850 pgdat->numabalancing_migrate_next_window = jiffies;
5852 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5853 spin_lock_init(&pgdat->split_queue_lock);
5854 INIT_LIST_HEAD(&pgdat->split_queue);
5855 pgdat->split_queue_len = 0;
5857 init_waitqueue_head(&pgdat->kswapd_wait);
5858 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5859 #ifdef CONFIG_COMPACTION
5860 init_waitqueue_head(&pgdat->kcompactd_wait);
5862 pgdat_page_ext_init(pgdat);
5863 spin_lock_init(&pgdat->lru_lock);
5864 lruvec_init(node_lruvec(pgdat));
5866 for (j = 0; j < MAX_NR_ZONES; j++) {
5867 struct zone *zone = pgdat->node_zones + j;
5868 unsigned long size, realsize, freesize, memmap_pages;
5869 unsigned long zone_start_pfn = zone->zone_start_pfn;
5871 size = zone->spanned_pages;
5872 realsize = freesize = zone->present_pages;
5875 * Adjust freesize so that it accounts for how much memory
5876 * is used by this zone for memmap. This affects the watermark
5877 * and per-cpu initialisations
5879 memmap_pages = calc_memmap_size(size, realsize);
5880 if (!is_highmem_idx(j)) {
5881 if (freesize >= memmap_pages) {
5882 freesize -= memmap_pages;
5885 " %s zone: %lu pages used for memmap\n",
5886 zone_names[j], memmap_pages);
5888 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5889 zone_names[j], memmap_pages, freesize);
5892 /* Account for reserved pages */
5893 if (j == 0 && freesize > dma_reserve) {
5894 freesize -= dma_reserve;
5895 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5896 zone_names[0], dma_reserve);
5899 if (!is_highmem_idx(j))
5900 nr_kernel_pages += freesize;
5901 /* Charge for highmem memmap if there are enough kernel pages */
5902 else if (nr_kernel_pages > memmap_pages * 2)
5903 nr_kernel_pages -= memmap_pages;
5904 nr_all_pages += freesize;
5907 * Set an approximate value for lowmem here, it will be adjusted
5908 * when the bootmem allocator frees pages into the buddy system.
5909 * And all highmem pages will be managed by the buddy system.
5911 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5915 zone->name = zone_names[j];
5916 zone->zone_pgdat = pgdat;
5917 spin_lock_init(&zone->lock);
5918 zone_seqlock_init(zone);
5919 zone_pcp_init(zone);
5924 set_pageblock_order();
5925 setup_usemap(pgdat, zone, zone_start_pfn, size);
5926 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5928 memmap_init(size, nid, j, zone_start_pfn);
5932 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
5934 unsigned long __maybe_unused start = 0;
5935 unsigned long __maybe_unused offset = 0;
5937 /* Skip empty nodes */
5938 if (!pgdat->node_spanned_pages)
5941 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5942 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5943 offset = pgdat->node_start_pfn - start;
5944 /* ia64 gets its own node_mem_map, before this, without bootmem */
5945 if (!pgdat->node_mem_map) {
5946 unsigned long size, end;
5950 * The zone's endpoints aren't required to be MAX_ORDER
5951 * aligned but the node_mem_map endpoints must be in order
5952 * for the buddy allocator to function correctly.
5954 end = pgdat_end_pfn(pgdat);
5955 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5956 size = (end - start) * sizeof(struct page);
5957 map = alloc_remap(pgdat->node_id, size);
5959 map = memblock_virt_alloc_node_nopanic(size,
5961 pgdat->node_mem_map = map + offset;
5963 #ifndef CONFIG_NEED_MULTIPLE_NODES
5965 * With no DISCONTIG, the global mem_map is just set as node 0's
5967 if (pgdat == NODE_DATA(0)) {
5968 mem_map = NODE_DATA(0)->node_mem_map;
5969 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5970 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5972 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5975 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5978 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5979 unsigned long node_start_pfn, unsigned long *zholes_size)
5981 pg_data_t *pgdat = NODE_DATA(nid);
5982 unsigned long start_pfn = 0;
5983 unsigned long end_pfn = 0;
5985 /* pg_data_t should be reset to zero when it's allocated */
5986 WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
5988 reset_deferred_meminit(pgdat);
5989 pgdat->node_id = nid;
5990 pgdat->node_start_pfn = node_start_pfn;
5991 pgdat->per_cpu_nodestats = NULL;
5992 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5993 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5994 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5995 (u64)start_pfn << PAGE_SHIFT,
5996 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5998 start_pfn = node_start_pfn;
6000 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
6001 zones_size, zholes_size);
6003 alloc_node_mem_map(pgdat);
6004 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6005 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6006 nid, (unsigned long)pgdat,
6007 (unsigned long)pgdat->node_mem_map);
6010 free_area_init_core(pgdat);
6013 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6015 #if MAX_NUMNODES > 1
6017 * Figure out the number of possible node ids.
6019 void __init setup_nr_node_ids(void)
6021 unsigned int highest;
6023 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
6024 nr_node_ids = highest + 1;
6029 * node_map_pfn_alignment - determine the maximum internode alignment
6031 * This function should be called after node map is populated and sorted.
6032 * It calculates the maximum power of two alignment which can distinguish
6035 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6036 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6037 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6038 * shifted, 1GiB is enough and this function will indicate so.
6040 * This is used to test whether pfn -> nid mapping of the chosen memory
6041 * model has fine enough granularity to avoid incorrect mapping for the
6042 * populated node map.
6044 * Returns the determined alignment in pfn's. 0 if there is no alignment
6045 * requirement (single node).
6047 unsigned long __init node_map_pfn_alignment(void)
6049 unsigned long accl_mask = 0, last_end = 0;
6050 unsigned long start, end, mask;
6054 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
6055 if (!start || last_nid < 0 || last_nid == nid) {
6062 * Start with a mask granular enough to pin-point to the
6063 * start pfn and tick off bits one-by-one until it becomes
6064 * too coarse to separate the current node from the last.
6066 mask = ~((1 << __ffs(start)) - 1);
6067 while (mask && last_end <= (start & (mask << 1)))
6070 /* accumulate all internode masks */
6074 /* convert mask to number of pages */
6075 return ~accl_mask + 1;
6078 /* Find the lowest pfn for a node */
6079 static unsigned long __init find_min_pfn_for_node(int nid)
6081 unsigned long min_pfn = ULONG_MAX;
6082 unsigned long start_pfn;
6085 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
6086 min_pfn = min(min_pfn, start_pfn);
6088 if (min_pfn == ULONG_MAX) {
6089 pr_warn("Could not find start_pfn for node %d\n", nid);
6097 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6099 * It returns the minimum PFN based on information provided via
6100 * memblock_set_node().
6102 unsigned long __init find_min_pfn_with_active_regions(void)
6104 return find_min_pfn_for_node(MAX_NUMNODES);
6108 * early_calculate_totalpages()
6109 * Sum pages in active regions for movable zone.
6110 * Populate N_MEMORY for calculating usable_nodes.
6112 static unsigned long __init early_calculate_totalpages(void)
6114 unsigned long totalpages = 0;
6115 unsigned long start_pfn, end_pfn;
6118 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6119 unsigned long pages = end_pfn - start_pfn;
6121 totalpages += pages;
6123 node_set_state(nid, N_MEMORY);
6129 * Find the PFN the Movable zone begins in each node. Kernel memory
6130 * is spread evenly between nodes as long as the nodes have enough
6131 * memory. When they don't, some nodes will have more kernelcore than
6134 static void __init find_zone_movable_pfns_for_nodes(void)
6137 unsigned long usable_startpfn;
6138 unsigned long kernelcore_node, kernelcore_remaining;
6139 /* save the state before borrow the nodemask */
6140 nodemask_t saved_node_state = node_states[N_MEMORY];
6141 unsigned long totalpages = early_calculate_totalpages();
6142 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6143 struct memblock_region *r;
6145 /* Need to find movable_zone earlier when movable_node is specified. */
6146 find_usable_zone_for_movable();
6149 * If movable_node is specified, ignore kernelcore and movablecore
6152 if (movable_node_is_enabled()) {
6153 for_each_memblock(memory, r) {
6154 if (!memblock_is_hotpluggable(r))
6159 usable_startpfn = PFN_DOWN(r->base);
6160 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6161 min(usable_startpfn, zone_movable_pfn[nid]) :
6169 * If kernelcore=mirror is specified, ignore movablecore option
6171 if (mirrored_kernelcore) {
6172 bool mem_below_4gb_not_mirrored = false;
6174 for_each_memblock(memory, r) {
6175 if (memblock_is_mirror(r))
6180 usable_startpfn = memblock_region_memory_base_pfn(r);
6182 if (usable_startpfn < 0x100000) {
6183 mem_below_4gb_not_mirrored = true;
6187 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6188 min(usable_startpfn, zone_movable_pfn[nid]) :
6192 if (mem_below_4gb_not_mirrored)
6193 pr_warn("This configuration results in unmirrored kernel memory.");
6199 * If movablecore=nn[KMG] was specified, calculate what size of
6200 * kernelcore that corresponds so that memory usable for
6201 * any allocation type is evenly spread. If both kernelcore
6202 * and movablecore are specified, then the value of kernelcore
6203 * will be used for required_kernelcore if it's greater than
6204 * what movablecore would have allowed.
6206 if (required_movablecore) {
6207 unsigned long corepages;
6210 * Round-up so that ZONE_MOVABLE is at least as large as what
6211 * was requested by the user
6213 required_movablecore =
6214 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6215 required_movablecore = min(totalpages, required_movablecore);
6216 corepages = totalpages - required_movablecore;
6218 required_kernelcore = max(required_kernelcore, corepages);
6222 * If kernelcore was not specified or kernelcore size is larger
6223 * than totalpages, there is no ZONE_MOVABLE.
6225 if (!required_kernelcore || required_kernelcore >= totalpages)
6228 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6229 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6232 /* Spread kernelcore memory as evenly as possible throughout nodes */
6233 kernelcore_node = required_kernelcore / usable_nodes;
6234 for_each_node_state(nid, N_MEMORY) {
6235 unsigned long start_pfn, end_pfn;
6238 * Recalculate kernelcore_node if the division per node
6239 * now exceeds what is necessary to satisfy the requested
6240 * amount of memory for the kernel
6242 if (required_kernelcore < kernelcore_node)
6243 kernelcore_node = required_kernelcore / usable_nodes;
6246 * As the map is walked, we track how much memory is usable
6247 * by the kernel using kernelcore_remaining. When it is
6248 * 0, the rest of the node is usable by ZONE_MOVABLE
6250 kernelcore_remaining = kernelcore_node;
6252 /* Go through each range of PFNs within this node */
6253 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6254 unsigned long size_pages;
6256 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6257 if (start_pfn >= end_pfn)
6260 /* Account for what is only usable for kernelcore */
6261 if (start_pfn < usable_startpfn) {
6262 unsigned long kernel_pages;
6263 kernel_pages = min(end_pfn, usable_startpfn)
6266 kernelcore_remaining -= min(kernel_pages,
6267 kernelcore_remaining);
6268 required_kernelcore -= min(kernel_pages,
6269 required_kernelcore);
6271 /* Continue if range is now fully accounted */
6272 if (end_pfn <= usable_startpfn) {
6275 * Push zone_movable_pfn to the end so
6276 * that if we have to rebalance
6277 * kernelcore across nodes, we will
6278 * not double account here
6280 zone_movable_pfn[nid] = end_pfn;
6283 start_pfn = usable_startpfn;
6287 * The usable PFN range for ZONE_MOVABLE is from
6288 * start_pfn->end_pfn. Calculate size_pages as the
6289 * number of pages used as kernelcore
6291 size_pages = end_pfn - start_pfn;
6292 if (size_pages > kernelcore_remaining)
6293 size_pages = kernelcore_remaining;
6294 zone_movable_pfn[nid] = start_pfn + size_pages;
6297 * Some kernelcore has been met, update counts and
6298 * break if the kernelcore for this node has been
6301 required_kernelcore -= min(required_kernelcore,
6303 kernelcore_remaining -= size_pages;
6304 if (!kernelcore_remaining)
6310 * If there is still required_kernelcore, we do another pass with one
6311 * less node in the count. This will push zone_movable_pfn[nid] further
6312 * along on the nodes that still have memory until kernelcore is
6316 if (usable_nodes && required_kernelcore > usable_nodes)
6320 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6321 for (nid = 0; nid < MAX_NUMNODES; nid++)
6322 zone_movable_pfn[nid] =
6323 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6326 /* restore the node_state */
6327 node_states[N_MEMORY] = saved_node_state;
6330 /* Any regular or high memory on that node ? */
6331 static void check_for_memory(pg_data_t *pgdat, int nid)
6333 enum zone_type zone_type;
6335 if (N_MEMORY == N_NORMAL_MEMORY)
6338 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6339 struct zone *zone = &pgdat->node_zones[zone_type];
6340 if (populated_zone(zone)) {
6341 node_set_state(nid, N_HIGH_MEMORY);
6342 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6343 zone_type <= ZONE_NORMAL)
6344 node_set_state(nid, N_NORMAL_MEMORY);
6351 * free_area_init_nodes - Initialise all pg_data_t and zone data
6352 * @max_zone_pfn: an array of max PFNs for each zone
6354 * This will call free_area_init_node() for each active node in the system.
6355 * Using the page ranges provided by memblock_set_node(), the size of each
6356 * zone in each node and their holes is calculated. If the maximum PFN
6357 * between two adjacent zones match, it is assumed that the zone is empty.
6358 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6359 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6360 * starts where the previous one ended. For example, ZONE_DMA32 starts
6361 * at arch_max_dma_pfn.
6363 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6365 unsigned long start_pfn, end_pfn;
6368 /* Record where the zone boundaries are */
6369 memset(arch_zone_lowest_possible_pfn, 0,
6370 sizeof(arch_zone_lowest_possible_pfn));
6371 memset(arch_zone_highest_possible_pfn, 0,
6372 sizeof(arch_zone_highest_possible_pfn));
6374 start_pfn = find_min_pfn_with_active_regions();
6376 for (i = 0; i < MAX_NR_ZONES; i++) {
6377 if (i == ZONE_MOVABLE)
6380 end_pfn = max(max_zone_pfn[i], start_pfn);
6381 arch_zone_lowest_possible_pfn[i] = start_pfn;
6382 arch_zone_highest_possible_pfn[i] = end_pfn;
6384 start_pfn = end_pfn;
6386 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6387 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6389 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6390 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6391 find_zone_movable_pfns_for_nodes();
6393 /* Print out the zone ranges */
6394 pr_info("Zone ranges:\n");
6395 for (i = 0; i < MAX_NR_ZONES; i++) {
6396 if (i == ZONE_MOVABLE)
6398 pr_info(" %-8s ", zone_names[i]);
6399 if (arch_zone_lowest_possible_pfn[i] ==
6400 arch_zone_highest_possible_pfn[i])
6403 pr_cont("[mem %#018Lx-%#018Lx]\n",
6404 (u64)arch_zone_lowest_possible_pfn[i]
6406 ((u64)arch_zone_highest_possible_pfn[i]
6407 << PAGE_SHIFT) - 1);
6410 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6411 pr_info("Movable zone start for each node\n");
6412 for (i = 0; i < MAX_NUMNODES; i++) {
6413 if (zone_movable_pfn[i])
6414 pr_info(" Node %d: %#018Lx\n", i,
6415 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6418 /* Print out the early node map */
6419 pr_info("Early memory node ranges\n");
6420 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6421 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6422 (u64)start_pfn << PAGE_SHIFT,
6423 ((u64)end_pfn << PAGE_SHIFT) - 1);
6425 /* Initialise every node */
6426 mminit_verify_pageflags_layout();
6427 setup_nr_node_ids();
6428 for_each_online_node(nid) {
6429 pg_data_t *pgdat = NODE_DATA(nid);
6430 free_area_init_node(nid, NULL,
6431 find_min_pfn_for_node(nid), NULL);
6433 /* Any memory on that node */
6434 if (pgdat->node_present_pages)
6435 node_set_state(nid, N_MEMORY);
6436 check_for_memory(pgdat, nid);
6440 static int __init cmdline_parse_core(char *p, unsigned long *core)
6442 unsigned long long coremem;
6446 coremem = memparse(p, &p);
6447 *core = coremem >> PAGE_SHIFT;
6449 /* Paranoid check that UL is enough for the coremem value */
6450 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6456 * kernelcore=size sets the amount of memory for use for allocations that
6457 * cannot be reclaimed or migrated.
6459 static int __init cmdline_parse_kernelcore(char *p)
6461 /* parse kernelcore=mirror */
6462 if (parse_option_str(p, "mirror")) {
6463 mirrored_kernelcore = true;
6467 return cmdline_parse_core(p, &required_kernelcore);
6471 * movablecore=size sets the amount of memory for use for allocations that
6472 * can be reclaimed or migrated.
6474 static int __init cmdline_parse_movablecore(char *p)
6476 return cmdline_parse_core(p, &required_movablecore);
6479 early_param("kernelcore", cmdline_parse_kernelcore);
6480 early_param("movablecore", cmdline_parse_movablecore);
6482 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6484 void adjust_managed_page_count(struct page *page, long count)
6486 spin_lock(&managed_page_count_lock);
6487 page_zone(page)->managed_pages += count;
6488 totalram_pages += count;
6489 #ifdef CONFIG_HIGHMEM
6490 if (PageHighMem(page))
6491 totalhigh_pages += count;
6493 spin_unlock(&managed_page_count_lock);
6495 EXPORT_SYMBOL(adjust_managed_page_count);
6497 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6500 unsigned long pages = 0;
6502 start = (void *)PAGE_ALIGN((unsigned long)start);
6503 end = (void *)((unsigned long)end & PAGE_MASK);
6504 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6505 if ((unsigned int)poison <= 0xFF)
6506 memset(pos, poison, PAGE_SIZE);
6507 free_reserved_page(virt_to_page(pos));
6511 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6512 s, pages << (PAGE_SHIFT - 10), start, end);
6516 EXPORT_SYMBOL(free_reserved_area);
6518 #ifdef CONFIG_HIGHMEM
6519 void free_highmem_page(struct page *page)
6521 __free_reserved_page(page);
6523 page_zone(page)->managed_pages++;
6529 void __init mem_init_print_info(const char *str)
6531 unsigned long physpages, codesize, datasize, rosize, bss_size;
6532 unsigned long init_code_size, init_data_size;
6534 physpages = get_num_physpages();
6535 codesize = _etext - _stext;
6536 datasize = _edata - _sdata;
6537 rosize = __end_rodata - __start_rodata;
6538 bss_size = __bss_stop - __bss_start;
6539 init_data_size = __init_end - __init_begin;
6540 init_code_size = _einittext - _sinittext;
6543 * Detect special cases and adjust section sizes accordingly:
6544 * 1) .init.* may be embedded into .data sections
6545 * 2) .init.text.* may be out of [__init_begin, __init_end],
6546 * please refer to arch/tile/kernel/vmlinux.lds.S.
6547 * 3) .rodata.* may be embedded into .text or .data sections.
6549 #define adj_init_size(start, end, size, pos, adj) \
6551 if (start <= pos && pos < end && size > adj) \
6555 adj_init_size(__init_begin, __init_end, init_data_size,
6556 _sinittext, init_code_size);
6557 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6558 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6559 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6560 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6562 #undef adj_init_size
6564 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6565 #ifdef CONFIG_HIGHMEM
6569 nr_free_pages() << (PAGE_SHIFT - 10),
6570 physpages << (PAGE_SHIFT - 10),
6571 codesize >> 10, datasize >> 10, rosize >> 10,
6572 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6573 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6574 totalcma_pages << (PAGE_SHIFT - 10),
6575 #ifdef CONFIG_HIGHMEM
6576 totalhigh_pages << (PAGE_SHIFT - 10),
6578 str ? ", " : "", str ? str : "");
6582 * set_dma_reserve - set the specified number of pages reserved in the first zone
6583 * @new_dma_reserve: The number of pages to mark reserved
6585 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6586 * In the DMA zone, a significant percentage may be consumed by kernel image
6587 * and other unfreeable allocations which can skew the watermarks badly. This
6588 * function may optionally be used to account for unfreeable pages in the
6589 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6590 * smaller per-cpu batchsize.
6592 void __init set_dma_reserve(unsigned long new_dma_reserve)
6594 dma_reserve = new_dma_reserve;
6597 void __init free_area_init(unsigned long *zones_size)
6599 free_area_init_node(0, zones_size,
6600 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6603 static int page_alloc_cpu_notify(struct notifier_block *self,
6604 unsigned long action, void *hcpu)
6606 int cpu = (unsigned long)hcpu;
6608 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6609 lru_add_drain_cpu(cpu);
6613 * Spill the event counters of the dead processor
6614 * into the current processors event counters.
6615 * This artificially elevates the count of the current
6618 vm_events_fold_cpu(cpu);
6621 * Zero the differential counters of the dead processor
6622 * so that the vm statistics are consistent.
6624 * This is only okay since the processor is dead and cannot
6625 * race with what we are doing.
6627 cpu_vm_stats_fold(cpu);
6632 void __init page_alloc_init(void)
6634 hotcpu_notifier(page_alloc_cpu_notify, 0);
6638 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6639 * or min_free_kbytes changes.
6641 static void calculate_totalreserve_pages(void)
6643 struct pglist_data *pgdat;
6644 unsigned long reserve_pages = 0;
6645 enum zone_type i, j;
6647 for_each_online_pgdat(pgdat) {
6649 pgdat->totalreserve_pages = 0;
6651 for (i = 0; i < MAX_NR_ZONES; i++) {
6652 struct zone *zone = pgdat->node_zones + i;
6655 /* Find valid and maximum lowmem_reserve in the zone */
6656 for (j = i; j < MAX_NR_ZONES; j++) {
6657 if (zone->lowmem_reserve[j] > max)
6658 max = zone->lowmem_reserve[j];
6661 /* we treat the high watermark as reserved pages. */
6662 max += high_wmark_pages(zone);
6664 if (max > zone->managed_pages)
6665 max = zone->managed_pages;
6667 pgdat->totalreserve_pages += max;
6669 reserve_pages += max;
6672 totalreserve_pages = reserve_pages;
6676 * setup_per_zone_lowmem_reserve - called whenever
6677 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6678 * has a correct pages reserved value, so an adequate number of
6679 * pages are left in the zone after a successful __alloc_pages().
6681 static void setup_per_zone_lowmem_reserve(void)
6683 struct pglist_data *pgdat;
6684 enum zone_type j, idx;
6686 for_each_online_pgdat(pgdat) {
6687 for (j = 0; j < MAX_NR_ZONES; j++) {
6688 struct zone *zone = pgdat->node_zones + j;
6689 unsigned long managed_pages = zone->managed_pages;
6691 zone->lowmem_reserve[j] = 0;
6695 struct zone *lower_zone;
6699 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6700 sysctl_lowmem_reserve_ratio[idx] = 1;
6702 lower_zone = pgdat->node_zones + idx;
6703 lower_zone->lowmem_reserve[j] = managed_pages /
6704 sysctl_lowmem_reserve_ratio[idx];
6705 managed_pages += lower_zone->managed_pages;
6710 /* update totalreserve_pages */
6711 calculate_totalreserve_pages();
6714 static void __setup_per_zone_wmarks(void)
6716 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6717 unsigned long lowmem_pages = 0;
6719 unsigned long flags;
6721 /* Calculate total number of !ZONE_HIGHMEM pages */
6722 for_each_zone(zone) {
6723 if (!is_highmem(zone))
6724 lowmem_pages += zone->managed_pages;
6727 for_each_zone(zone) {
6730 spin_lock_irqsave(&zone->lock, flags);
6731 tmp = (u64)pages_min * zone->managed_pages;
6732 do_div(tmp, lowmem_pages);
6733 if (is_highmem(zone)) {
6735 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6736 * need highmem pages, so cap pages_min to a small
6739 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6740 * deltas control asynch page reclaim, and so should
6741 * not be capped for highmem.
6743 unsigned long min_pages;
6745 min_pages = zone->managed_pages / 1024;
6746 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6747 zone->watermark[WMARK_MIN] = min_pages;
6750 * If it's a lowmem zone, reserve a number of pages
6751 * proportionate to the zone's size.
6753 zone->watermark[WMARK_MIN] = tmp;
6757 * Set the kswapd watermarks distance according to the
6758 * scale factor in proportion to available memory, but
6759 * ensure a minimum size on small systems.
6761 tmp = max_t(u64, tmp >> 2,
6762 mult_frac(zone->managed_pages,
6763 watermark_scale_factor, 10000));
6765 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6766 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6768 spin_unlock_irqrestore(&zone->lock, flags);
6771 /* update totalreserve_pages */
6772 calculate_totalreserve_pages();
6776 * setup_per_zone_wmarks - called when min_free_kbytes changes
6777 * or when memory is hot-{added|removed}
6779 * Ensures that the watermark[min,low,high] values for each zone are set
6780 * correctly with respect to min_free_kbytes.
6782 void setup_per_zone_wmarks(void)
6784 mutex_lock(&zonelists_mutex);
6785 __setup_per_zone_wmarks();
6786 mutex_unlock(&zonelists_mutex);
6790 * Initialise min_free_kbytes.
6792 * For small machines we want it small (128k min). For large machines
6793 * we want it large (64MB max). But it is not linear, because network
6794 * bandwidth does not increase linearly with machine size. We use
6796 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6797 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6813 int __meminit init_per_zone_wmark_min(void)
6815 unsigned long lowmem_kbytes;
6816 int new_min_free_kbytes;
6818 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6819 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6821 if (new_min_free_kbytes > user_min_free_kbytes) {
6822 min_free_kbytes = new_min_free_kbytes;
6823 if (min_free_kbytes < 128)
6824 min_free_kbytes = 128;
6825 if (min_free_kbytes > 65536)
6826 min_free_kbytes = 65536;
6828 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6829 new_min_free_kbytes, user_min_free_kbytes);
6831 setup_per_zone_wmarks();
6832 refresh_zone_stat_thresholds();
6833 setup_per_zone_lowmem_reserve();
6836 setup_min_unmapped_ratio();
6837 setup_min_slab_ratio();
6842 core_initcall(init_per_zone_wmark_min)
6845 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6846 * that we can call two helper functions whenever min_free_kbytes
6849 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6850 void __user *buffer, size_t *length, loff_t *ppos)
6854 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6859 user_min_free_kbytes = min_free_kbytes;
6860 setup_per_zone_wmarks();
6865 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6866 void __user *buffer, size_t *length, loff_t *ppos)
6870 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6875 setup_per_zone_wmarks();
6881 static void setup_min_unmapped_ratio(void)
6886 for_each_online_pgdat(pgdat)
6887 pgdat->min_unmapped_pages = 0;
6890 zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
6891 sysctl_min_unmapped_ratio) / 100;
6895 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6896 void __user *buffer, size_t *length, loff_t *ppos)
6900 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6904 setup_min_unmapped_ratio();
6909 static void setup_min_slab_ratio(void)
6914 for_each_online_pgdat(pgdat)
6915 pgdat->min_slab_pages = 0;
6918 zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
6919 sysctl_min_slab_ratio) / 100;
6922 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6923 void __user *buffer, size_t *length, loff_t *ppos)
6927 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6931 setup_min_slab_ratio();
6938 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6939 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6940 * whenever sysctl_lowmem_reserve_ratio changes.
6942 * The reserve ratio obviously has absolutely no relation with the
6943 * minimum watermarks. The lowmem reserve ratio can only make sense
6944 * if in function of the boot time zone sizes.
6946 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6947 void __user *buffer, size_t *length, loff_t *ppos)
6949 proc_dointvec_minmax(table, write, buffer, length, ppos);
6950 setup_per_zone_lowmem_reserve();
6955 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6956 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6957 * pagelist can have before it gets flushed back to buddy allocator.
6959 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6960 void __user *buffer, size_t *length, loff_t *ppos)
6963 int old_percpu_pagelist_fraction;
6966 mutex_lock(&pcp_batch_high_lock);
6967 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6969 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6970 if (!write || ret < 0)
6973 /* Sanity checking to avoid pcp imbalance */
6974 if (percpu_pagelist_fraction &&
6975 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6976 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6982 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6985 for_each_populated_zone(zone) {
6988 for_each_possible_cpu(cpu)
6989 pageset_set_high_and_batch(zone,
6990 per_cpu_ptr(zone->pageset, cpu));
6993 mutex_unlock(&pcp_batch_high_lock);
6998 int hashdist = HASHDIST_DEFAULT;
7000 static int __init set_hashdist(char *str)
7004 hashdist = simple_strtoul(str, &str, 0);
7007 __setup("hashdist=", set_hashdist);
7010 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7012 * Returns the number of pages that arch has reserved but
7013 * is not known to alloc_large_system_hash().
7015 static unsigned long __init arch_reserved_kernel_pages(void)
7022 * allocate a large system hash table from bootmem
7023 * - it is assumed that the hash table must contain an exact power-of-2
7024 * quantity of entries
7025 * - limit is the number of hash buckets, not the total allocation size
7027 void *__init alloc_large_system_hash(const char *tablename,
7028 unsigned long bucketsize,
7029 unsigned long numentries,
7032 unsigned int *_hash_shift,
7033 unsigned int *_hash_mask,
7034 unsigned long low_limit,
7035 unsigned long high_limit)
7037 unsigned long long max = high_limit;
7038 unsigned long log2qty, size;
7041 /* allow the kernel cmdline to have a say */
7043 /* round applicable memory size up to nearest megabyte */
7044 numentries = nr_kernel_pages;
7045 numentries -= arch_reserved_kernel_pages();
7047 /* It isn't necessary when PAGE_SIZE >= 1MB */
7048 if (PAGE_SHIFT < 20)
7049 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
7051 /* limit to 1 bucket per 2^scale bytes of low memory */
7052 if (scale > PAGE_SHIFT)
7053 numentries >>= (scale - PAGE_SHIFT);
7055 numentries <<= (PAGE_SHIFT - scale);
7057 /* Make sure we've got at least a 0-order allocation.. */
7058 if (unlikely(flags & HASH_SMALL)) {
7059 /* Makes no sense without HASH_EARLY */
7060 WARN_ON(!(flags & HASH_EARLY));
7061 if (!(numentries >> *_hash_shift)) {
7062 numentries = 1UL << *_hash_shift;
7063 BUG_ON(!numentries);
7065 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
7066 numentries = PAGE_SIZE / bucketsize;
7068 numentries = roundup_pow_of_two(numentries);
7070 /* limit allocation size to 1/16 total memory by default */
7072 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
7073 do_div(max, bucketsize);
7075 max = min(max, 0x80000000ULL);
7077 if (numentries < low_limit)
7078 numentries = low_limit;
7079 if (numentries > max)
7082 log2qty = ilog2(numentries);
7085 size = bucketsize << log2qty;
7086 if (flags & HASH_EARLY)
7087 table = memblock_virt_alloc_nopanic(size, 0);
7089 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
7092 * If bucketsize is not a power-of-two, we may free
7093 * some pages at the end of hash table which
7094 * alloc_pages_exact() automatically does
7096 if (get_order(size) < MAX_ORDER) {
7097 table = alloc_pages_exact(size, GFP_ATOMIC);
7098 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
7101 } while (!table && size > PAGE_SIZE && --log2qty);
7104 panic("Failed to allocate %s hash table\n", tablename);
7106 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7107 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7110 *_hash_shift = log2qty;
7112 *_hash_mask = (1 << log2qty) - 1;
7118 * This function checks whether pageblock includes unmovable pages or not.
7119 * If @count is not zero, it is okay to include less @count unmovable pages
7121 * PageLRU check without isolation or lru_lock could race so that
7122 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7123 * expect this function should be exact.
7125 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7126 bool skip_hwpoisoned_pages)
7128 unsigned long pfn, iter, found;
7132 * For avoiding noise data, lru_add_drain_all() should be called
7133 * If ZONE_MOVABLE, the zone never contains unmovable pages
7135 if (zone_idx(zone) == ZONE_MOVABLE)
7137 mt = get_pageblock_migratetype(page);
7138 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
7141 pfn = page_to_pfn(page);
7142 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7143 unsigned long check = pfn + iter;
7145 if (!pfn_valid_within(check))
7148 page = pfn_to_page(check);
7151 * Hugepages are not in LRU lists, but they're movable.
7152 * We need not scan over tail pages bacause we don't
7153 * handle each tail page individually in migration.
7155 if (PageHuge(page)) {
7156 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7161 * We can't use page_count without pin a page
7162 * because another CPU can free compound page.
7163 * This check already skips compound tails of THP
7164 * because their page->_refcount is zero at all time.
7166 if (!page_ref_count(page)) {
7167 if (PageBuddy(page))
7168 iter += (1 << page_order(page)) - 1;
7173 * The HWPoisoned page may be not in buddy system, and
7174 * page_count() is not 0.
7176 if (skip_hwpoisoned_pages && PageHWPoison(page))
7182 * If there are RECLAIMABLE pages, we need to check
7183 * it. But now, memory offline itself doesn't call
7184 * shrink_node_slabs() and it still to be fixed.
7187 * If the page is not RAM, page_count()should be 0.
7188 * we don't need more check. This is an _used_ not-movable page.
7190 * The problematic thing here is PG_reserved pages. PG_reserved
7191 * is set to both of a memory hole page and a _used_ kernel
7200 bool is_pageblock_removable_nolock(struct page *page)
7206 * We have to be careful here because we are iterating over memory
7207 * sections which are not zone aware so we might end up outside of
7208 * the zone but still within the section.
7209 * We have to take care about the node as well. If the node is offline
7210 * its NODE_DATA will be NULL - see page_zone.
7212 if (!node_online(page_to_nid(page)))
7215 zone = page_zone(page);
7216 pfn = page_to_pfn(page);
7217 if (!zone_spans_pfn(zone, pfn))
7220 return !has_unmovable_pages(zone, page, 0, true);
7223 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7225 static unsigned long pfn_max_align_down(unsigned long pfn)
7227 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7228 pageblock_nr_pages) - 1);
7231 static unsigned long pfn_max_align_up(unsigned long pfn)
7233 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7234 pageblock_nr_pages));
7237 /* [start, end) must belong to a single zone. */
7238 static int __alloc_contig_migrate_range(struct compact_control *cc,
7239 unsigned long start, unsigned long end)
7241 /* This function is based on compact_zone() from compaction.c. */
7242 unsigned long nr_reclaimed;
7243 unsigned long pfn = start;
7244 unsigned int tries = 0;
7249 while (pfn < end || !list_empty(&cc->migratepages)) {
7250 if (fatal_signal_pending(current)) {
7255 if (list_empty(&cc->migratepages)) {
7256 cc->nr_migratepages = 0;
7257 pfn = isolate_migratepages_range(cc, pfn, end);
7263 } else if (++tries == 5) {
7264 ret = ret < 0 ? ret : -EBUSY;
7268 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7270 cc->nr_migratepages -= nr_reclaimed;
7272 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7273 NULL, 0, cc->mode, MR_CMA);
7276 putback_movable_pages(&cc->migratepages);
7283 * alloc_contig_range() -- tries to allocate given range of pages
7284 * @start: start PFN to allocate
7285 * @end: one-past-the-last PFN to allocate
7286 * @migratetype: migratetype of the underlaying pageblocks (either
7287 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7288 * in range must have the same migratetype and it must
7289 * be either of the two.
7291 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7292 * aligned, however it's the caller's responsibility to guarantee that
7293 * we are the only thread that changes migrate type of pageblocks the
7296 * The PFN range must belong to a single zone.
7298 * Returns zero on success or negative error code. On success all
7299 * pages which PFN is in [start, end) are allocated for the caller and
7300 * need to be freed with free_contig_range().
7302 int alloc_contig_range(unsigned long start, unsigned long end,
7303 unsigned migratetype)
7305 unsigned long outer_start, outer_end;
7309 struct compact_control cc = {
7310 .nr_migratepages = 0,
7312 .zone = page_zone(pfn_to_page(start)),
7313 .mode = MIGRATE_SYNC,
7314 .ignore_skip_hint = true,
7316 INIT_LIST_HEAD(&cc.migratepages);
7319 * What we do here is we mark all pageblocks in range as
7320 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7321 * have different sizes, and due to the way page allocator
7322 * work, we align the range to biggest of the two pages so
7323 * that page allocator won't try to merge buddies from
7324 * different pageblocks and change MIGRATE_ISOLATE to some
7325 * other migration type.
7327 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7328 * migrate the pages from an unaligned range (ie. pages that
7329 * we are interested in). This will put all the pages in
7330 * range back to page allocator as MIGRATE_ISOLATE.
7332 * When this is done, we take the pages in range from page
7333 * allocator removing them from the buddy system. This way
7334 * page allocator will never consider using them.
7336 * This lets us mark the pageblocks back as
7337 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7338 * aligned range but not in the unaligned, original range are
7339 * put back to page allocator so that buddy can use them.
7342 ret = start_isolate_page_range(pfn_max_align_down(start),
7343 pfn_max_align_up(end), migratetype,
7349 * In case of -EBUSY, we'd like to know which page causes problem.
7350 * So, just fall through. We will check it in test_pages_isolated().
7352 ret = __alloc_contig_migrate_range(&cc, start, end);
7353 if (ret && ret != -EBUSY)
7357 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7358 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7359 * more, all pages in [start, end) are free in page allocator.
7360 * What we are going to do is to allocate all pages from
7361 * [start, end) (that is remove them from page allocator).
7363 * The only problem is that pages at the beginning and at the
7364 * end of interesting range may be not aligned with pages that
7365 * page allocator holds, ie. they can be part of higher order
7366 * pages. Because of this, we reserve the bigger range and
7367 * once this is done free the pages we are not interested in.
7369 * We don't have to hold zone->lock here because the pages are
7370 * isolated thus they won't get removed from buddy.
7373 lru_add_drain_all();
7374 drain_all_pages(cc.zone);
7377 outer_start = start;
7378 while (!PageBuddy(pfn_to_page(outer_start))) {
7379 if (++order >= MAX_ORDER) {
7380 outer_start = start;
7383 outer_start &= ~0UL << order;
7386 if (outer_start != start) {
7387 order = page_order(pfn_to_page(outer_start));
7390 * outer_start page could be small order buddy page and
7391 * it doesn't include start page. Adjust outer_start
7392 * in this case to report failed page properly
7393 * on tracepoint in test_pages_isolated()
7395 if (outer_start + (1UL << order) <= start)
7396 outer_start = start;
7399 /* Make sure the range is really isolated. */
7400 if (test_pages_isolated(outer_start, end, false)) {
7401 pr_info("%s: [%lx, %lx) PFNs busy\n",
7402 __func__, outer_start, end);
7407 /* Grab isolated pages from freelists. */
7408 outer_end = isolate_freepages_range(&cc, outer_start, end);
7414 /* Free head and tail (if any) */
7415 if (start != outer_start)
7416 free_contig_range(outer_start, start - outer_start);
7417 if (end != outer_end)
7418 free_contig_range(end, outer_end - end);
7421 undo_isolate_page_range(pfn_max_align_down(start),
7422 pfn_max_align_up(end), migratetype);
7426 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7428 unsigned int count = 0;
7430 for (; nr_pages--; pfn++) {
7431 struct page *page = pfn_to_page(pfn);
7433 count += page_count(page) != 1;
7436 WARN(count != 0, "%d pages are still in use!\n", count);
7440 #ifdef CONFIG_MEMORY_HOTPLUG
7442 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7443 * page high values need to be recalulated.
7445 void __meminit zone_pcp_update(struct zone *zone)
7448 mutex_lock(&pcp_batch_high_lock);
7449 for_each_possible_cpu(cpu)
7450 pageset_set_high_and_batch(zone,
7451 per_cpu_ptr(zone->pageset, cpu));
7452 mutex_unlock(&pcp_batch_high_lock);
7456 void zone_pcp_reset(struct zone *zone)
7458 unsigned long flags;
7460 struct per_cpu_pageset *pset;
7462 /* avoid races with drain_pages() */
7463 local_irq_save(flags);
7464 if (zone->pageset != &boot_pageset) {
7465 for_each_online_cpu(cpu) {
7466 pset = per_cpu_ptr(zone->pageset, cpu);
7467 drain_zonestat(zone, pset);
7469 free_percpu(zone->pageset);
7470 zone->pageset = &boot_pageset;
7472 local_irq_restore(flags);
7475 #ifdef CONFIG_MEMORY_HOTREMOVE
7477 * All pages in the range must be in a single zone and isolated
7478 * before calling this.
7481 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7485 unsigned int order, i;
7487 unsigned long flags;
7488 /* find the first valid pfn */
7489 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7494 zone = page_zone(pfn_to_page(pfn));
7495 spin_lock_irqsave(&zone->lock, flags);
7497 while (pfn < end_pfn) {
7498 if (!pfn_valid(pfn)) {
7502 page = pfn_to_page(pfn);
7504 * The HWPoisoned page may be not in buddy system, and
7505 * page_count() is not 0.
7507 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7509 SetPageReserved(page);
7513 BUG_ON(page_count(page));
7514 BUG_ON(!PageBuddy(page));
7515 order = page_order(page);
7516 #ifdef CONFIG_DEBUG_VM
7517 pr_info("remove from free list %lx %d %lx\n",
7518 pfn, 1 << order, end_pfn);
7520 list_del(&page->lru);
7521 rmv_page_order(page);
7522 zone->free_area[order].nr_free--;
7523 for (i = 0; i < (1 << order); i++)
7524 SetPageReserved((page+i));
7525 pfn += (1 << order);
7527 spin_unlock_irqrestore(&zone->lock, flags);
7531 bool is_free_buddy_page(struct page *page)
7533 struct zone *zone = page_zone(page);
7534 unsigned long pfn = page_to_pfn(page);
7535 unsigned long flags;
7538 spin_lock_irqsave(&zone->lock, flags);
7539 for (order = 0; order < MAX_ORDER; order++) {
7540 struct page *page_head = page - (pfn & ((1 << order) - 1));
7542 if (PageBuddy(page_head) && page_order(page_head) >= order)
7545 spin_unlock_irqrestore(&zone->lock, flags);
7547 return order < MAX_ORDER;