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 unsigned long 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);
2221 if (is_migrate_cma(get_pcppage_migratetype(page)))
2222 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2227 * i pages were removed from the buddy list even if some leak due
2228 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2229 * on i. Do not confuse with 'alloced' which is the number of
2230 * pages added to the pcp list.
2232 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2233 spin_unlock(&zone->lock);
2239 * Called from the vmstat counter updater to drain pagesets of this
2240 * currently executing processor on remote nodes after they have
2243 * Note that this function must be called with the thread pinned to
2244 * a single processor.
2246 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2248 unsigned long flags;
2249 int to_drain, batch;
2251 local_irq_save(flags);
2252 batch = READ_ONCE(pcp->batch);
2253 to_drain = min(pcp->count, batch);
2255 free_pcppages_bulk(zone, to_drain, pcp);
2256 pcp->count -= to_drain;
2258 local_irq_restore(flags);
2263 * Drain pcplists of the indicated processor and zone.
2265 * The processor must either be the current processor and the
2266 * thread pinned to the current processor or a processor that
2269 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2271 unsigned long flags;
2272 struct per_cpu_pageset *pset;
2273 struct per_cpu_pages *pcp;
2275 local_irq_save(flags);
2276 pset = per_cpu_ptr(zone->pageset, cpu);
2280 free_pcppages_bulk(zone, pcp->count, pcp);
2283 local_irq_restore(flags);
2287 * Drain pcplists of all zones on the indicated processor.
2289 * The processor must either be the current processor and the
2290 * thread pinned to the current processor or a processor that
2293 static void drain_pages(unsigned int cpu)
2297 for_each_populated_zone(zone) {
2298 drain_pages_zone(cpu, zone);
2303 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2305 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2306 * the single zone's pages.
2308 void drain_local_pages(struct zone *zone)
2310 int cpu = smp_processor_id();
2313 drain_pages_zone(cpu, zone);
2319 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2321 * When zone parameter is non-NULL, spill just the single zone's pages.
2323 * Note that this code is protected against sending an IPI to an offline
2324 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2325 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2326 * nothing keeps CPUs from showing up after we populated the cpumask and
2327 * before the call to on_each_cpu_mask().
2329 void drain_all_pages(struct zone *zone)
2334 * Allocate in the BSS so we wont require allocation in
2335 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2337 static cpumask_t cpus_with_pcps;
2340 * We don't care about racing with CPU hotplug event
2341 * as offline notification will cause the notified
2342 * cpu to drain that CPU pcps and on_each_cpu_mask
2343 * disables preemption as part of its processing
2345 for_each_online_cpu(cpu) {
2346 struct per_cpu_pageset *pcp;
2348 bool has_pcps = false;
2351 pcp = per_cpu_ptr(zone->pageset, cpu);
2355 for_each_populated_zone(z) {
2356 pcp = per_cpu_ptr(z->pageset, cpu);
2357 if (pcp->pcp.count) {
2365 cpumask_set_cpu(cpu, &cpus_with_pcps);
2367 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2369 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2373 #ifdef CONFIG_HIBERNATION
2375 void mark_free_pages(struct zone *zone)
2377 unsigned long pfn, max_zone_pfn;
2378 unsigned long flags;
2379 unsigned int order, t;
2382 if (zone_is_empty(zone))
2385 spin_lock_irqsave(&zone->lock, flags);
2387 max_zone_pfn = zone_end_pfn(zone);
2388 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2389 if (pfn_valid(pfn)) {
2390 page = pfn_to_page(pfn);
2392 if (page_zone(page) != zone)
2395 if (!swsusp_page_is_forbidden(page))
2396 swsusp_unset_page_free(page);
2399 for_each_migratetype_order(order, t) {
2400 list_for_each_entry(page,
2401 &zone->free_area[order].free_list[t], lru) {
2404 pfn = page_to_pfn(page);
2405 for (i = 0; i < (1UL << order); i++)
2406 swsusp_set_page_free(pfn_to_page(pfn + i));
2409 spin_unlock_irqrestore(&zone->lock, flags);
2411 #endif /* CONFIG_PM */
2414 * Free a 0-order page
2415 * cold == true ? free a cold page : free a hot page
2417 void free_hot_cold_page(struct page *page, bool cold)
2419 struct zone *zone = page_zone(page);
2420 struct per_cpu_pages *pcp;
2421 unsigned long flags;
2422 unsigned long pfn = page_to_pfn(page);
2425 if (!free_pcp_prepare(page))
2428 migratetype = get_pfnblock_migratetype(page, pfn);
2429 set_pcppage_migratetype(page, migratetype);
2430 local_irq_save(flags);
2431 __count_vm_event(PGFREE);
2434 * We only track unmovable, reclaimable and movable on pcp lists.
2435 * Free ISOLATE pages back to the allocator because they are being
2436 * offlined but treat RESERVE as movable pages so we can get those
2437 * areas back if necessary. Otherwise, we may have to free
2438 * excessively into the page allocator
2440 if (migratetype >= MIGRATE_PCPTYPES) {
2441 if (unlikely(is_migrate_isolate(migratetype))) {
2442 free_one_page(zone, page, pfn, 0, migratetype);
2445 migratetype = MIGRATE_MOVABLE;
2448 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2450 list_add(&page->lru, &pcp->lists[migratetype]);
2452 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2454 if (pcp->count >= pcp->high) {
2455 unsigned long batch = READ_ONCE(pcp->batch);
2456 free_pcppages_bulk(zone, batch, pcp);
2457 pcp->count -= batch;
2461 local_irq_restore(flags);
2465 * Free a list of 0-order pages
2467 void free_hot_cold_page_list(struct list_head *list, bool cold)
2469 struct page *page, *next;
2471 list_for_each_entry_safe(page, next, list, lru) {
2472 trace_mm_page_free_batched(page, cold);
2473 free_hot_cold_page(page, cold);
2478 * split_page takes a non-compound higher-order page, and splits it into
2479 * n (1<<order) sub-pages: page[0..n]
2480 * Each sub-page must be freed individually.
2482 * Note: this is probably too low level an operation for use in drivers.
2483 * Please consult with lkml before using this in your driver.
2485 void split_page(struct page *page, unsigned int order)
2489 VM_BUG_ON_PAGE(PageCompound(page), page);
2490 VM_BUG_ON_PAGE(!page_count(page), page);
2492 #ifdef CONFIG_KMEMCHECK
2494 * Split shadow pages too, because free(page[0]) would
2495 * otherwise free the whole shadow.
2497 if (kmemcheck_page_is_tracked(page))
2498 split_page(virt_to_page(page[0].shadow), order);
2501 for (i = 1; i < (1 << order); i++)
2502 set_page_refcounted(page + i);
2503 split_page_owner(page, order);
2505 EXPORT_SYMBOL_GPL(split_page);
2507 int __isolate_free_page(struct page *page, unsigned int order)
2509 unsigned long watermark;
2513 BUG_ON(!PageBuddy(page));
2515 zone = page_zone(page);
2516 mt = get_pageblock_migratetype(page);
2518 if (!is_migrate_isolate(mt)) {
2520 * Obey watermarks as if the page was being allocated. We can
2521 * emulate a high-order watermark check with a raised order-0
2522 * watermark, because we already know our high-order page
2525 watermark = min_wmark_pages(zone) + (1UL << order);
2526 if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
2529 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2532 /* Remove page from free list */
2533 list_del(&page->lru);
2534 zone->free_area[order].nr_free--;
2535 rmv_page_order(page);
2538 * Set the pageblock if the isolated page is at least half of a
2541 if (order >= pageblock_order - 1) {
2542 struct page *endpage = page + (1 << order) - 1;
2543 for (; page < endpage; page += pageblock_nr_pages) {
2544 int mt = get_pageblock_migratetype(page);
2545 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2546 set_pageblock_migratetype(page,
2552 return 1UL << order;
2556 * Update NUMA hit/miss statistics
2558 * Must be called with interrupts disabled.
2560 * When __GFP_OTHER_NODE is set assume the node of the preferred
2561 * zone is the local node. This is useful for daemons who allocate
2562 * memory on behalf of other processes.
2564 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2568 int local_nid = numa_node_id();
2569 enum zone_stat_item local_stat = NUMA_LOCAL;
2571 if (unlikely(flags & __GFP_OTHER_NODE)) {
2572 local_stat = NUMA_OTHER;
2573 local_nid = preferred_zone->node;
2576 if (z->node == local_nid) {
2577 __inc_zone_state(z, NUMA_HIT);
2578 __inc_zone_state(z, local_stat);
2580 __inc_zone_state(z, NUMA_MISS);
2581 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2587 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2590 struct page *buffered_rmqueue(struct zone *preferred_zone,
2591 struct zone *zone, unsigned int order,
2592 gfp_t gfp_flags, unsigned int alloc_flags,
2595 unsigned long flags;
2597 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2599 if (likely(order == 0)) {
2600 struct per_cpu_pages *pcp;
2601 struct list_head *list;
2603 local_irq_save(flags);
2605 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2606 list = &pcp->lists[migratetype];
2607 if (list_empty(list)) {
2608 pcp->count += rmqueue_bulk(zone, 0,
2611 if (unlikely(list_empty(list)))
2616 page = list_last_entry(list, struct page, lru);
2618 page = list_first_entry(list, struct page, lru);
2620 list_del(&page->lru);
2623 } while (check_new_pcp(page));
2626 * We most definitely don't want callers attempting to
2627 * allocate greater than order-1 page units with __GFP_NOFAIL.
2629 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2630 spin_lock_irqsave(&zone->lock, flags);
2634 if (alloc_flags & ALLOC_HARDER) {
2635 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2637 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2640 page = __rmqueue(zone, order, migratetype);
2641 } while (page && check_new_pages(page, order));
2642 spin_unlock(&zone->lock);
2645 __mod_zone_freepage_state(zone, -(1 << order),
2646 get_pcppage_migratetype(page));
2649 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
2650 zone_statistics(preferred_zone, zone, gfp_flags);
2651 local_irq_restore(flags);
2653 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2657 local_irq_restore(flags);
2661 #ifdef CONFIG_FAIL_PAGE_ALLOC
2664 struct fault_attr attr;
2666 bool ignore_gfp_highmem;
2667 bool ignore_gfp_reclaim;
2669 } fail_page_alloc = {
2670 .attr = FAULT_ATTR_INITIALIZER,
2671 .ignore_gfp_reclaim = true,
2672 .ignore_gfp_highmem = true,
2676 static int __init setup_fail_page_alloc(char *str)
2678 return setup_fault_attr(&fail_page_alloc.attr, str);
2680 __setup("fail_page_alloc=", setup_fail_page_alloc);
2682 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2684 if (order < fail_page_alloc.min_order)
2686 if (gfp_mask & __GFP_NOFAIL)
2688 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2690 if (fail_page_alloc.ignore_gfp_reclaim &&
2691 (gfp_mask & __GFP_DIRECT_RECLAIM))
2694 return should_fail(&fail_page_alloc.attr, 1 << order);
2697 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2699 static int __init fail_page_alloc_debugfs(void)
2701 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2704 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2705 &fail_page_alloc.attr);
2707 return PTR_ERR(dir);
2709 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2710 &fail_page_alloc.ignore_gfp_reclaim))
2712 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2713 &fail_page_alloc.ignore_gfp_highmem))
2715 if (!debugfs_create_u32("min-order", mode, dir,
2716 &fail_page_alloc.min_order))
2721 debugfs_remove_recursive(dir);
2726 late_initcall(fail_page_alloc_debugfs);
2728 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2730 #else /* CONFIG_FAIL_PAGE_ALLOC */
2732 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2737 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2740 * Return true if free base pages are above 'mark'. For high-order checks it
2741 * will return true of the order-0 watermark is reached and there is at least
2742 * one free page of a suitable size. Checking now avoids taking the zone lock
2743 * to check in the allocation paths if no pages are free.
2745 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2746 int classzone_idx, unsigned int alloc_flags,
2751 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2753 /* free_pages may go negative - that's OK */
2754 free_pages -= (1 << order) - 1;
2756 if (alloc_flags & ALLOC_HIGH)
2760 * If the caller does not have rights to ALLOC_HARDER then subtract
2761 * the high-atomic reserves. This will over-estimate the size of the
2762 * atomic reserve but it avoids a search.
2764 if (likely(!alloc_harder))
2765 free_pages -= z->nr_reserved_highatomic;
2770 /* If allocation can't use CMA areas don't use free CMA pages */
2771 if (!(alloc_flags & ALLOC_CMA))
2772 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2776 * Check watermarks for an order-0 allocation request. If these
2777 * are not met, then a high-order request also cannot go ahead
2778 * even if a suitable page happened to be free.
2780 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2783 /* If this is an order-0 request then the watermark is fine */
2787 /* For a high-order request, check at least one suitable page is free */
2788 for (o = order; o < MAX_ORDER; o++) {
2789 struct free_area *area = &z->free_area[o];
2798 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2799 if (!list_empty(&area->free_list[mt]))
2804 if ((alloc_flags & ALLOC_CMA) &&
2805 !list_empty(&area->free_list[MIGRATE_CMA])) {
2813 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2814 int classzone_idx, unsigned int alloc_flags)
2816 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2817 zone_page_state(z, NR_FREE_PAGES));
2820 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2821 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2823 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2827 /* If allocation can't use CMA areas don't use free CMA pages */
2828 if (!(alloc_flags & ALLOC_CMA))
2829 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2833 * Fast check for order-0 only. If this fails then the reserves
2834 * need to be calculated. There is a corner case where the check
2835 * passes but only the high-order atomic reserve are free. If
2836 * the caller is !atomic then it'll uselessly search the free
2837 * list. That corner case is then slower but it is harmless.
2839 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2842 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2846 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2847 unsigned long mark, int classzone_idx)
2849 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2851 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2852 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2854 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2859 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2861 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2864 #else /* CONFIG_NUMA */
2865 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2869 #endif /* CONFIG_NUMA */
2872 * get_page_from_freelist goes through the zonelist trying to allocate
2875 static struct page *
2876 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2877 const struct alloc_context *ac)
2879 struct zoneref *z = ac->preferred_zoneref;
2881 struct pglist_data *last_pgdat_dirty_limit = NULL;
2884 * Scan zonelist, looking for a zone with enough free.
2885 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2887 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
2892 if (cpusets_enabled() &&
2893 (alloc_flags & ALLOC_CPUSET) &&
2894 !__cpuset_zone_allowed(zone, gfp_mask))
2897 * When allocating a page cache page for writing, we
2898 * want to get it from a node that is within its dirty
2899 * limit, such that no single node holds more than its
2900 * proportional share of globally allowed dirty pages.
2901 * The dirty limits take into account the node's
2902 * lowmem reserves and high watermark so that kswapd
2903 * should be able to balance it without having to
2904 * write pages from its LRU list.
2906 * XXX: For now, allow allocations to potentially
2907 * exceed the per-node dirty limit in the slowpath
2908 * (spread_dirty_pages unset) before going into reclaim,
2909 * which is important when on a NUMA setup the allowed
2910 * nodes are together not big enough to reach the
2911 * global limit. The proper fix for these situations
2912 * will require awareness of nodes in the
2913 * dirty-throttling and the flusher threads.
2915 if (ac->spread_dirty_pages) {
2916 if (last_pgdat_dirty_limit == zone->zone_pgdat)
2919 if (!node_dirty_ok(zone->zone_pgdat)) {
2920 last_pgdat_dirty_limit = zone->zone_pgdat;
2925 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2926 if (!zone_watermark_fast(zone, order, mark,
2927 ac_classzone_idx(ac), alloc_flags)) {
2930 /* Checked here to keep the fast path fast */
2931 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2932 if (alloc_flags & ALLOC_NO_WATERMARKS)
2935 if (node_reclaim_mode == 0 ||
2936 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
2939 ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
2941 case NODE_RECLAIM_NOSCAN:
2944 case NODE_RECLAIM_FULL:
2945 /* scanned but unreclaimable */
2948 /* did we reclaim enough */
2949 if (zone_watermark_ok(zone, order, mark,
2950 ac_classzone_idx(ac), alloc_flags))
2958 page = buffered_rmqueue(ac->preferred_zoneref->zone, zone, order,
2959 gfp_mask, alloc_flags, ac->migratetype);
2961 prep_new_page(page, order, gfp_mask, alloc_flags);
2964 * If this is a high-order atomic allocation then check
2965 * if the pageblock should be reserved for the future
2967 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
2968 reserve_highatomic_pageblock(page, zone, order);
2978 * Large machines with many possible nodes should not always dump per-node
2979 * meminfo in irq context.
2981 static inline bool should_suppress_show_mem(void)
2986 ret = in_interrupt();
2991 static DEFINE_RATELIMIT_STATE(nopage_rs,
2992 DEFAULT_RATELIMIT_INTERVAL,
2993 DEFAULT_RATELIMIT_BURST);
2995 void warn_alloc(gfp_t gfp_mask, const char *fmt, ...)
2997 unsigned int filter = SHOW_MEM_FILTER_NODES;
2998 struct va_format vaf;
3001 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
3002 debug_guardpage_minorder() > 0)
3006 * This documents exceptions given to allocations in certain
3007 * contexts that are allowed to allocate outside current's set
3010 if (!(gfp_mask & __GFP_NOMEMALLOC))
3011 if (test_thread_flag(TIF_MEMDIE) ||
3012 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3013 filter &= ~SHOW_MEM_FILTER_NODES;
3014 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3015 filter &= ~SHOW_MEM_FILTER_NODES;
3017 pr_warn("%s: ", current->comm);
3019 va_start(args, fmt);
3022 pr_cont("%pV", &vaf);
3025 pr_cont(", mode:%#x(%pGg)\n", gfp_mask, &gfp_mask);
3028 if (!should_suppress_show_mem())
3032 static inline struct page *
3033 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3034 const struct alloc_context *ac, unsigned long *did_some_progress)
3036 struct oom_control oc = {
3037 .zonelist = ac->zonelist,
3038 .nodemask = ac->nodemask,
3040 .gfp_mask = gfp_mask,
3045 *did_some_progress = 0;
3048 * Acquire the oom lock. If that fails, somebody else is
3049 * making progress for us.
3051 if (!mutex_trylock(&oom_lock)) {
3052 *did_some_progress = 1;
3053 schedule_timeout_uninterruptible(1);
3058 * Go through the zonelist yet one more time, keep very high watermark
3059 * here, this is only to catch a parallel oom killing, we must fail if
3060 * we're still under heavy pressure.
3062 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3063 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3067 if (!(gfp_mask & __GFP_NOFAIL)) {
3068 /* Coredumps can quickly deplete all memory reserves */
3069 if (current->flags & PF_DUMPCORE)
3071 /* The OOM killer will not help higher order allocs */
3072 if (order > PAGE_ALLOC_COSTLY_ORDER)
3074 /* The OOM killer does not needlessly kill tasks for lowmem */
3075 if (ac->high_zoneidx < ZONE_NORMAL)
3077 if (pm_suspended_storage())
3080 * XXX: GFP_NOFS allocations should rather fail than rely on
3081 * other request to make a forward progress.
3082 * We are in an unfortunate situation where out_of_memory cannot
3083 * do much for this context but let's try it to at least get
3084 * access to memory reserved if the current task is killed (see
3085 * out_of_memory). Once filesystems are ready to handle allocation
3086 * failures more gracefully we should just bail out here.
3089 /* The OOM killer may not free memory on a specific node */
3090 if (gfp_mask & __GFP_THISNODE)
3093 /* Exhausted what can be done so it's blamo time */
3094 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3095 *did_some_progress = 1;
3097 if (gfp_mask & __GFP_NOFAIL) {
3098 page = get_page_from_freelist(gfp_mask, order,
3099 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
3101 * fallback to ignore cpuset restriction if our nodes
3105 page = get_page_from_freelist(gfp_mask, order,
3106 ALLOC_NO_WATERMARKS, ac);
3110 mutex_unlock(&oom_lock);
3115 * Maximum number of compaction retries wit a progress before OOM
3116 * killer is consider as the only way to move forward.
3118 #define MAX_COMPACT_RETRIES 16
3120 #ifdef CONFIG_COMPACTION
3121 /* Try memory compaction for high-order allocations before reclaim */
3122 static struct page *
3123 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3124 unsigned int alloc_flags, const struct alloc_context *ac,
3125 enum compact_priority prio, enum compact_result *compact_result)
3132 current->flags |= PF_MEMALLOC;
3133 *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3135 current->flags &= ~PF_MEMALLOC;
3137 if (*compact_result <= COMPACT_INACTIVE)
3141 * At least in one zone compaction wasn't deferred or skipped, so let's
3142 * count a compaction stall
3144 count_vm_event(COMPACTSTALL);
3146 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3149 struct zone *zone = page_zone(page);
3151 zone->compact_blockskip_flush = false;
3152 compaction_defer_reset(zone, order, true);
3153 count_vm_event(COMPACTSUCCESS);
3158 * It's bad if compaction run occurs and fails. The most likely reason
3159 * is that pages exist, but not enough to satisfy watermarks.
3161 count_vm_event(COMPACTFAIL);
3169 should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
3170 enum compact_result compact_result,
3171 enum compact_priority *compact_priority,
3172 int *compaction_retries)
3174 int max_retries = MAX_COMPACT_RETRIES;
3180 if (compaction_made_progress(compact_result))
3181 (*compaction_retries)++;
3184 * compaction considers all the zone as desperately out of memory
3185 * so it doesn't really make much sense to retry except when the
3186 * failure could be caused by insufficient priority
3188 if (compaction_failed(compact_result))
3189 goto check_priority;
3192 * make sure the compaction wasn't deferred or didn't bail out early
3193 * due to locks contention before we declare that we should give up.
3194 * But do not retry if the given zonelist is not suitable for
3197 if (compaction_withdrawn(compact_result))
3198 return compaction_zonelist_suitable(ac, order, alloc_flags);
3201 * !costly requests are much more important than __GFP_REPEAT
3202 * costly ones because they are de facto nofail and invoke OOM
3203 * killer to move on while costly can fail and users are ready
3204 * to cope with that. 1/4 retries is rather arbitrary but we
3205 * would need much more detailed feedback from compaction to
3206 * make a better decision.
3208 if (order > PAGE_ALLOC_COSTLY_ORDER)
3210 if (*compaction_retries <= max_retries)
3214 * Make sure there are attempts at the highest priority if we exhausted
3215 * all retries or failed at the lower priorities.
3218 min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
3219 MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
3220 if (*compact_priority > min_priority) {
3221 (*compact_priority)--;
3222 *compaction_retries = 0;
3228 static inline struct page *
3229 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3230 unsigned int alloc_flags, const struct alloc_context *ac,
3231 enum compact_priority prio, enum compact_result *compact_result)
3233 *compact_result = COMPACT_SKIPPED;
3238 should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
3239 enum compact_result compact_result,
3240 enum compact_priority *compact_priority,
3241 int *compaction_retries)
3246 if (!order || order > PAGE_ALLOC_COSTLY_ORDER)
3250 * There are setups with compaction disabled which would prefer to loop
3251 * inside the allocator rather than hit the oom killer prematurely.
3252 * Let's give them a good hope and keep retrying while the order-0
3253 * watermarks are OK.
3255 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3257 if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
3258 ac_classzone_idx(ac), alloc_flags))
3263 #endif /* CONFIG_COMPACTION */
3265 /* Perform direct synchronous page reclaim */
3267 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3268 const struct alloc_context *ac)
3270 struct reclaim_state reclaim_state;
3275 /* We now go into synchronous reclaim */
3276 cpuset_memory_pressure_bump();
3277 current->flags |= PF_MEMALLOC;
3278 lockdep_set_current_reclaim_state(gfp_mask);
3279 reclaim_state.reclaimed_slab = 0;
3280 current->reclaim_state = &reclaim_state;
3282 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3285 current->reclaim_state = NULL;
3286 lockdep_clear_current_reclaim_state();
3287 current->flags &= ~PF_MEMALLOC;
3294 /* The really slow allocator path where we enter direct reclaim */
3295 static inline struct page *
3296 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3297 unsigned int alloc_flags, const struct alloc_context *ac,
3298 unsigned long *did_some_progress)
3300 struct page *page = NULL;
3301 bool drained = false;
3303 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3304 if (unlikely(!(*did_some_progress)))
3308 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3311 * If an allocation failed after direct reclaim, it could be because
3312 * pages are pinned on the per-cpu lists or in high alloc reserves.
3313 * Shrink them them and try again
3315 if (!page && !drained) {
3316 unreserve_highatomic_pageblock(ac);
3317 drain_all_pages(NULL);
3325 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3329 pg_data_t *last_pgdat = NULL;
3331 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3332 ac->high_zoneidx, ac->nodemask) {
3333 if (last_pgdat != zone->zone_pgdat)
3334 wakeup_kswapd(zone, order, ac->high_zoneidx);
3335 last_pgdat = zone->zone_pgdat;
3339 static inline unsigned int
3340 gfp_to_alloc_flags(gfp_t gfp_mask)
3342 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3344 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3345 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3348 * The caller may dip into page reserves a bit more if the caller
3349 * cannot run direct reclaim, or if the caller has realtime scheduling
3350 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3351 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3353 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3355 if (gfp_mask & __GFP_ATOMIC) {
3357 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3358 * if it can't schedule.
3360 if (!(gfp_mask & __GFP_NOMEMALLOC))
3361 alloc_flags |= ALLOC_HARDER;
3363 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3364 * comment for __cpuset_node_allowed().
3366 alloc_flags &= ~ALLOC_CPUSET;
3367 } else if (unlikely(rt_task(current)) && !in_interrupt())
3368 alloc_flags |= ALLOC_HARDER;
3371 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3372 alloc_flags |= ALLOC_CMA;
3377 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3379 if (unlikely(gfp_mask & __GFP_NOMEMALLOC))
3382 if (gfp_mask & __GFP_MEMALLOC)
3384 if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3386 if (!in_interrupt() &&
3387 ((current->flags & PF_MEMALLOC) ||
3388 unlikely(test_thread_flag(TIF_MEMDIE))))
3395 * Maximum number of reclaim retries without any progress before OOM killer
3396 * is consider as the only way to move forward.
3398 #define MAX_RECLAIM_RETRIES 16
3401 * Checks whether it makes sense to retry the reclaim to make a forward progress
3402 * for the given allocation request.
3403 * The reclaim feedback represented by did_some_progress (any progress during
3404 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3405 * any progress in a row) is considered as well as the reclaimable pages on the
3406 * applicable zone list (with a backoff mechanism which is a function of
3407 * no_progress_loops).
3409 * Returns true if a retry is viable or false to enter the oom path.
3412 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
3413 struct alloc_context *ac, int alloc_flags,
3414 bool did_some_progress, int *no_progress_loops)
3420 * Costly allocations might have made a progress but this doesn't mean
3421 * their order will become available due to high fragmentation so
3422 * always increment the no progress counter for them
3424 if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
3425 *no_progress_loops = 0;
3427 (*no_progress_loops)++;
3430 * Make sure we converge to OOM if we cannot make any progress
3431 * several times in the row.
3433 if (*no_progress_loops > MAX_RECLAIM_RETRIES)
3437 * Keep reclaiming pages while there is a chance this will lead
3438 * somewhere. If none of the target zones can satisfy our allocation
3439 * request even if all reclaimable pages are considered then we are
3440 * screwed and have to go OOM.
3442 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
3444 unsigned long available;
3445 unsigned long reclaimable;
3447 available = reclaimable = zone_reclaimable_pages(zone);
3448 available -= DIV_ROUND_UP((*no_progress_loops) * available,
3449 MAX_RECLAIM_RETRIES);
3450 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
3453 * Would the allocation succeed if we reclaimed the whole
3456 if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
3457 ac_classzone_idx(ac), alloc_flags, available)) {
3459 * If we didn't make any progress and have a lot of
3460 * dirty + writeback pages then we should wait for
3461 * an IO to complete to slow down the reclaim and
3462 * prevent from pre mature OOM
3464 if (!did_some_progress) {
3465 unsigned long write_pending;
3467 write_pending = zone_page_state_snapshot(zone,
3468 NR_ZONE_WRITE_PENDING);
3470 if (2 * write_pending > reclaimable) {
3471 congestion_wait(BLK_RW_ASYNC, HZ/10);
3477 * Memory allocation/reclaim might be called from a WQ
3478 * context and the current implementation of the WQ
3479 * concurrency control doesn't recognize that
3480 * a particular WQ is congested if the worker thread is
3481 * looping without ever sleeping. Therefore we have to
3482 * do a short sleep here rather than calling
3485 if (current->flags & PF_WQ_WORKER)
3486 schedule_timeout_uninterruptible(1);
3497 static inline struct page *
3498 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3499 struct alloc_context *ac)
3501 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3502 struct page *page = NULL;
3503 unsigned int alloc_flags;
3504 unsigned long did_some_progress;
3505 enum compact_priority compact_priority = DEF_COMPACT_PRIORITY;
3506 enum compact_result compact_result;
3507 int compaction_retries = 0;
3508 int no_progress_loops = 0;
3509 unsigned long alloc_start = jiffies;
3510 unsigned int stall_timeout = 10 * HZ;
3513 * In the slowpath, we sanity check order to avoid ever trying to
3514 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3515 * be using allocators in order of preference for an area that is
3518 if (order >= MAX_ORDER) {
3519 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3524 * We also sanity check to catch abuse of atomic reserves being used by
3525 * callers that are not in atomic context.
3527 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3528 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3529 gfp_mask &= ~__GFP_ATOMIC;
3532 * The fast path uses conservative alloc_flags to succeed only until
3533 * kswapd needs to be woken up, and to avoid the cost of setting up
3534 * alloc_flags precisely. So we do that now.
3536 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3538 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3539 wake_all_kswapds(order, ac);
3542 * The adjusted alloc_flags might result in immediate success, so try
3545 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3550 * For costly allocations, try direct compaction first, as it's likely
3551 * that we have enough base pages and don't need to reclaim. Don't try
3552 * that for allocations that are allowed to ignore watermarks, as the
3553 * ALLOC_NO_WATERMARKS attempt didn't yet happen.
3555 if (can_direct_reclaim && order > PAGE_ALLOC_COSTLY_ORDER &&
3556 !gfp_pfmemalloc_allowed(gfp_mask)) {
3557 page = __alloc_pages_direct_compact(gfp_mask, order,
3559 INIT_COMPACT_PRIORITY,
3565 * Checks for costly allocations with __GFP_NORETRY, which
3566 * includes THP page fault allocations
3568 if (gfp_mask & __GFP_NORETRY) {
3570 * If compaction is deferred for high-order allocations,
3571 * it is because sync compaction recently failed. If
3572 * this is the case and the caller requested a THP
3573 * allocation, we do not want to heavily disrupt the
3574 * system, so we fail the allocation instead of entering
3577 if (compact_result == COMPACT_DEFERRED)
3581 * Looks like reclaim/compaction is worth trying, but
3582 * sync compaction could be very expensive, so keep
3583 * using async compaction.
3585 compact_priority = INIT_COMPACT_PRIORITY;
3590 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3591 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3592 wake_all_kswapds(order, ac);
3594 if (gfp_pfmemalloc_allowed(gfp_mask))
3595 alloc_flags = ALLOC_NO_WATERMARKS;
3598 * Reset the zonelist iterators if memory policies can be ignored.
3599 * These allocations are high priority and system rather than user
3602 if (!(alloc_flags & ALLOC_CPUSET) || (alloc_flags & ALLOC_NO_WATERMARKS)) {
3603 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3604 ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
3605 ac->high_zoneidx, ac->nodemask);
3608 /* Attempt with potentially adjusted zonelist and alloc_flags */
3609 page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
3613 /* Caller is not willing to reclaim, we can't balance anything */
3614 if (!can_direct_reclaim) {
3616 * All existing users of the __GFP_NOFAIL are blockable, so warn
3617 * of any new users that actually allow this type of allocation
3620 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3624 /* Avoid recursion of direct reclaim */
3625 if (current->flags & PF_MEMALLOC) {
3627 * __GFP_NOFAIL request from this context is rather bizarre
3628 * because we cannot reclaim anything and only can loop waiting
3629 * for somebody to do a work for us.
3631 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3638 /* Avoid allocations with no watermarks from looping endlessly */
3639 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3643 /* Try direct reclaim and then allocating */
3644 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3645 &did_some_progress);
3649 /* Try direct compaction and then allocating */
3650 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3651 compact_priority, &compact_result);
3655 /* Do not loop if specifically requested */
3656 if (gfp_mask & __GFP_NORETRY)
3660 * Do not retry costly high order allocations unless they are
3663 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
3666 /* Make sure we know about allocations which stall for too long */
3667 if (time_after(jiffies, alloc_start + stall_timeout)) {
3668 warn_alloc(gfp_mask,
3669 "page allocation stalls for %ums, order:%u",
3670 jiffies_to_msecs(jiffies-alloc_start), order);
3671 stall_timeout += 10 * HZ;
3674 if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
3675 did_some_progress > 0, &no_progress_loops))
3679 * It doesn't make any sense to retry for the compaction if the order-0
3680 * reclaim is not able to make any progress because the current
3681 * implementation of the compaction depends on the sufficient amount
3682 * of free memory (see __compaction_suitable)
3684 if (did_some_progress > 0 &&
3685 should_compact_retry(ac, order, alloc_flags,
3686 compact_result, &compact_priority,
3687 &compaction_retries))
3690 /* Reclaim has failed us, start killing things */
3691 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3695 /* Retry as long as the OOM killer is making progress */
3696 if (did_some_progress) {
3697 no_progress_loops = 0;
3702 warn_alloc(gfp_mask,
3703 "page allocation failure: order:%u", order);
3709 * This is the 'heart' of the zoned buddy allocator.
3712 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3713 struct zonelist *zonelist, nodemask_t *nodemask)
3716 unsigned int cpuset_mems_cookie;
3717 unsigned int alloc_flags = ALLOC_WMARK_LOW;
3718 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3719 struct alloc_context ac = {
3720 .high_zoneidx = gfp_zone(gfp_mask),
3721 .zonelist = zonelist,
3722 .nodemask = nodemask,
3723 .migratetype = gfpflags_to_migratetype(gfp_mask),
3726 if (cpusets_enabled()) {
3727 alloc_mask |= __GFP_HARDWALL;
3728 alloc_flags |= ALLOC_CPUSET;
3730 ac.nodemask = &cpuset_current_mems_allowed;
3733 gfp_mask &= gfp_allowed_mask;
3735 lockdep_trace_alloc(gfp_mask);
3737 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3739 if (should_fail_alloc_page(gfp_mask, order))
3743 * Check the zones suitable for the gfp_mask contain at least one
3744 * valid zone. It's possible to have an empty zonelist as a result
3745 * of __GFP_THISNODE and a memoryless node
3747 if (unlikely(!zonelist->_zonerefs->zone))
3750 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3751 alloc_flags |= ALLOC_CMA;
3754 cpuset_mems_cookie = read_mems_allowed_begin();
3756 /* Dirty zone balancing only done in the fast path */
3757 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3760 * The preferred zone is used for statistics but crucially it is
3761 * also used as the starting point for the zonelist iterator. It
3762 * may get reset for allocations that ignore memory policies.
3764 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3765 ac.high_zoneidx, ac.nodemask);
3766 if (!ac.preferred_zoneref->zone) {
3771 /* First allocation attempt */
3772 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3777 * Runtime PM, block IO and its error handling path can deadlock
3778 * because I/O on the device might not complete.
3780 alloc_mask = memalloc_noio_flags(gfp_mask);
3781 ac.spread_dirty_pages = false;
3784 * Restore the original nodemask if it was potentially replaced with
3785 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3786 * Also recalculate the starting point for the zonelist iterator or
3787 * we could end up iterating over non-eligible zones endlessly.
3789 if (unlikely(ac.nodemask != nodemask)) {
3790 ac.nodemask = nodemask;
3791 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3792 ac.high_zoneidx, ac.nodemask);
3793 if (!ac.preferred_zoneref->zone)
3797 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3801 * When updating a task's mems_allowed, it is possible to race with
3802 * parallel threads in such a way that an allocation can fail while
3803 * the mask is being updated. If a page allocation is about to fail,
3804 * check if the cpuset changed during allocation and if so, retry.
3806 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3807 alloc_mask = gfp_mask;
3812 if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
3813 unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
3814 __free_pages(page, order);
3818 if (kmemcheck_enabled && page)
3819 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3821 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3825 EXPORT_SYMBOL(__alloc_pages_nodemask);
3828 * Common helper functions.
3830 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3835 * __get_free_pages() returns a 32-bit address, which cannot represent
3838 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3840 page = alloc_pages(gfp_mask, order);
3843 return (unsigned long) page_address(page);
3845 EXPORT_SYMBOL(__get_free_pages);
3847 unsigned long get_zeroed_page(gfp_t gfp_mask)
3849 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3851 EXPORT_SYMBOL(get_zeroed_page);
3853 void __free_pages(struct page *page, unsigned int order)
3855 if (put_page_testzero(page)) {
3857 free_hot_cold_page(page, false);
3859 __free_pages_ok(page, order);
3863 EXPORT_SYMBOL(__free_pages);
3865 void free_pages(unsigned long addr, unsigned int order)
3868 VM_BUG_ON(!virt_addr_valid((void *)addr));
3869 __free_pages(virt_to_page((void *)addr), order);
3873 EXPORT_SYMBOL(free_pages);
3877 * An arbitrary-length arbitrary-offset area of memory which resides
3878 * within a 0 or higher order page. Multiple fragments within that page
3879 * are individually refcounted, in the page's reference counter.
3881 * The page_frag functions below provide a simple allocation framework for
3882 * page fragments. This is used by the network stack and network device
3883 * drivers to provide a backing region of memory for use as either an
3884 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3886 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3889 struct page *page = NULL;
3890 gfp_t gfp = gfp_mask;
3892 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3893 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3895 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3896 PAGE_FRAG_CACHE_MAX_ORDER);
3897 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3899 if (unlikely(!page))
3900 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3902 nc->va = page ? page_address(page) : NULL;
3907 void *__alloc_page_frag(struct page_frag_cache *nc,
3908 unsigned int fragsz, gfp_t gfp_mask)
3910 unsigned int size = PAGE_SIZE;
3914 if (unlikely(!nc->va)) {
3916 page = __page_frag_refill(nc, gfp_mask);
3920 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3921 /* if size can vary use size else just use PAGE_SIZE */
3924 /* Even if we own the page, we do not use atomic_set().
3925 * This would break get_page_unless_zero() users.
3927 page_ref_add(page, size - 1);
3929 /* reset page count bias and offset to start of new frag */
3930 nc->pfmemalloc = page_is_pfmemalloc(page);
3931 nc->pagecnt_bias = size;
3935 offset = nc->offset - fragsz;
3936 if (unlikely(offset < 0)) {
3937 page = virt_to_page(nc->va);
3939 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3942 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3943 /* if size can vary use size else just use PAGE_SIZE */
3946 /* OK, page count is 0, we can safely set it */
3947 set_page_count(page, size);
3949 /* reset page count bias and offset to start of new frag */
3950 nc->pagecnt_bias = size;
3951 offset = size - fragsz;
3955 nc->offset = offset;
3957 return nc->va + offset;
3959 EXPORT_SYMBOL(__alloc_page_frag);
3962 * Frees a page fragment allocated out of either a compound or order 0 page.
3964 void __free_page_frag(void *addr)
3966 struct page *page = virt_to_head_page(addr);
3968 if (unlikely(put_page_testzero(page)))
3969 __free_pages_ok(page, compound_order(page));
3971 EXPORT_SYMBOL(__free_page_frag);
3973 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3977 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3978 unsigned long used = addr + PAGE_ALIGN(size);
3980 split_page(virt_to_page((void *)addr), order);
3981 while (used < alloc_end) {
3986 return (void *)addr;
3990 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3991 * @size: the number of bytes to allocate
3992 * @gfp_mask: GFP flags for the allocation
3994 * This function is similar to alloc_pages(), except that it allocates the
3995 * minimum number of pages to satisfy the request. alloc_pages() can only
3996 * allocate memory in power-of-two pages.
3998 * This function is also limited by MAX_ORDER.
4000 * Memory allocated by this function must be released by free_pages_exact().
4002 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
4004 unsigned int order = get_order(size);
4007 addr = __get_free_pages(gfp_mask, order);
4008 return make_alloc_exact(addr, order, size);
4010 EXPORT_SYMBOL(alloc_pages_exact);
4013 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4015 * @nid: the preferred node ID where memory should be allocated
4016 * @size: the number of bytes to allocate
4017 * @gfp_mask: GFP flags for the allocation
4019 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4022 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
4024 unsigned int order = get_order(size);
4025 struct page *p = alloc_pages_node(nid, gfp_mask, order);
4028 return make_alloc_exact((unsigned long)page_address(p), order, size);
4032 * free_pages_exact - release memory allocated via alloc_pages_exact()
4033 * @virt: the value returned by alloc_pages_exact.
4034 * @size: size of allocation, same value as passed to alloc_pages_exact().
4036 * Release the memory allocated by a previous call to alloc_pages_exact.
4038 void free_pages_exact(void *virt, size_t size)
4040 unsigned long addr = (unsigned long)virt;
4041 unsigned long end = addr + PAGE_ALIGN(size);
4043 while (addr < end) {
4048 EXPORT_SYMBOL(free_pages_exact);
4051 * nr_free_zone_pages - count number of pages beyond high watermark
4052 * @offset: The zone index of the highest zone
4054 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4055 * high watermark within all zones at or below a given zone index. For each
4056 * zone, the number of pages is calculated as:
4057 * managed_pages - high_pages
4059 static unsigned long nr_free_zone_pages(int offset)
4064 /* Just pick one node, since fallback list is circular */
4065 unsigned long sum = 0;
4067 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
4069 for_each_zone_zonelist(zone, z, zonelist, offset) {
4070 unsigned long size = zone->managed_pages;
4071 unsigned long high = high_wmark_pages(zone);
4080 * nr_free_buffer_pages - count number of pages beyond high watermark
4082 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4083 * watermark within ZONE_DMA and ZONE_NORMAL.
4085 unsigned long nr_free_buffer_pages(void)
4087 return nr_free_zone_pages(gfp_zone(GFP_USER));
4089 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
4092 * nr_free_pagecache_pages - count number of pages beyond high watermark
4094 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4095 * high watermark within all zones.
4097 unsigned long nr_free_pagecache_pages(void)
4099 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
4102 static inline void show_node(struct zone *zone)
4104 if (IS_ENABLED(CONFIG_NUMA))
4105 printk("Node %d ", zone_to_nid(zone));
4108 long si_mem_available(void)
4111 unsigned long pagecache;
4112 unsigned long wmark_low = 0;
4113 unsigned long pages[NR_LRU_LISTS];
4117 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
4118 pages[lru] = global_node_page_state(NR_LRU_BASE + lru);
4121 wmark_low += zone->watermark[WMARK_LOW];
4124 * Estimate the amount of memory available for userspace allocations,
4125 * without causing swapping.
4127 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
4130 * Not all the page cache can be freed, otherwise the system will
4131 * start swapping. Assume at least half of the page cache, or the
4132 * low watermark worth of cache, needs to stay.
4134 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4135 pagecache -= min(pagecache / 2, wmark_low);
4136 available += pagecache;
4139 * Part of the reclaimable slab consists of items that are in use,
4140 * and cannot be freed. Cap this estimate at the low watermark.
4142 available += global_page_state(NR_SLAB_RECLAIMABLE) -
4143 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
4149 EXPORT_SYMBOL_GPL(si_mem_available);
4151 void si_meminfo(struct sysinfo *val)
4153 val->totalram = totalram_pages;
4154 val->sharedram = global_node_page_state(NR_SHMEM);
4155 val->freeram = global_page_state(NR_FREE_PAGES);
4156 val->bufferram = nr_blockdev_pages();
4157 val->totalhigh = totalhigh_pages;
4158 val->freehigh = nr_free_highpages();
4159 val->mem_unit = PAGE_SIZE;
4162 EXPORT_SYMBOL(si_meminfo);
4165 void si_meminfo_node(struct sysinfo *val, int nid)
4167 int zone_type; /* needs to be signed */
4168 unsigned long managed_pages = 0;
4169 unsigned long managed_highpages = 0;
4170 unsigned long free_highpages = 0;
4171 pg_data_t *pgdat = NODE_DATA(nid);
4173 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4174 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4175 val->totalram = managed_pages;
4176 val->sharedram = node_page_state(pgdat, NR_SHMEM);
4177 val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
4178 #ifdef CONFIG_HIGHMEM
4179 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4180 struct zone *zone = &pgdat->node_zones[zone_type];
4182 if (is_highmem(zone)) {
4183 managed_highpages += zone->managed_pages;
4184 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4187 val->totalhigh = managed_highpages;
4188 val->freehigh = free_highpages;
4190 val->totalhigh = managed_highpages;
4191 val->freehigh = free_highpages;
4193 val->mem_unit = PAGE_SIZE;
4198 * Determine whether the node should be displayed or not, depending on whether
4199 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4201 bool skip_free_areas_node(unsigned int flags, int nid)
4204 unsigned int cpuset_mems_cookie;
4206 if (!(flags & SHOW_MEM_FILTER_NODES))
4210 cpuset_mems_cookie = read_mems_allowed_begin();
4211 ret = !node_isset(nid, cpuset_current_mems_allowed);
4212 } while (read_mems_allowed_retry(cpuset_mems_cookie));
4217 #define K(x) ((x) << (PAGE_SHIFT-10))
4219 static void show_migration_types(unsigned char type)
4221 static const char types[MIGRATE_TYPES] = {
4222 [MIGRATE_UNMOVABLE] = 'U',
4223 [MIGRATE_MOVABLE] = 'M',
4224 [MIGRATE_RECLAIMABLE] = 'E',
4225 [MIGRATE_HIGHATOMIC] = 'H',
4227 [MIGRATE_CMA] = 'C',
4229 #ifdef CONFIG_MEMORY_ISOLATION
4230 [MIGRATE_ISOLATE] = 'I',
4233 char tmp[MIGRATE_TYPES + 1];
4237 for (i = 0; i < MIGRATE_TYPES; i++) {
4238 if (type & (1 << i))
4243 printk(KERN_CONT "(%s) ", tmp);
4247 * Show free area list (used inside shift_scroll-lock stuff)
4248 * We also calculate the percentage fragmentation. We do this by counting the
4249 * memory on each free list with the exception of the first item on the list.
4252 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4255 void show_free_areas(unsigned int filter)
4257 unsigned long free_pcp = 0;
4262 for_each_populated_zone(zone) {
4263 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4266 for_each_online_cpu(cpu)
4267 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4270 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4271 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4272 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4273 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4274 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4275 " free:%lu free_pcp:%lu free_cma:%lu\n",
4276 global_node_page_state(NR_ACTIVE_ANON),
4277 global_node_page_state(NR_INACTIVE_ANON),
4278 global_node_page_state(NR_ISOLATED_ANON),
4279 global_node_page_state(NR_ACTIVE_FILE),
4280 global_node_page_state(NR_INACTIVE_FILE),
4281 global_node_page_state(NR_ISOLATED_FILE),
4282 global_node_page_state(NR_UNEVICTABLE),
4283 global_node_page_state(NR_FILE_DIRTY),
4284 global_node_page_state(NR_WRITEBACK),
4285 global_node_page_state(NR_UNSTABLE_NFS),
4286 global_page_state(NR_SLAB_RECLAIMABLE),
4287 global_page_state(NR_SLAB_UNRECLAIMABLE),
4288 global_node_page_state(NR_FILE_MAPPED),
4289 global_node_page_state(NR_SHMEM),
4290 global_page_state(NR_PAGETABLE),
4291 global_page_state(NR_BOUNCE),
4292 global_page_state(NR_FREE_PAGES),
4294 global_page_state(NR_FREE_CMA_PAGES));
4296 for_each_online_pgdat(pgdat) {
4298 " active_anon:%lukB"
4299 " inactive_anon:%lukB"
4300 " active_file:%lukB"
4301 " inactive_file:%lukB"
4302 " unevictable:%lukB"
4303 " isolated(anon):%lukB"
4304 " isolated(file):%lukB"
4309 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4311 " shmem_pmdmapped: %lukB"
4314 " writeback_tmp:%lukB"
4316 " pages_scanned:%lu"
4317 " all_unreclaimable? %s"
4320 K(node_page_state(pgdat, NR_ACTIVE_ANON)),
4321 K(node_page_state(pgdat, NR_INACTIVE_ANON)),
4322 K(node_page_state(pgdat, NR_ACTIVE_FILE)),
4323 K(node_page_state(pgdat, NR_INACTIVE_FILE)),
4324 K(node_page_state(pgdat, NR_UNEVICTABLE)),
4325 K(node_page_state(pgdat, NR_ISOLATED_ANON)),
4326 K(node_page_state(pgdat, NR_ISOLATED_FILE)),
4327 K(node_page_state(pgdat, NR_FILE_MAPPED)),
4328 K(node_page_state(pgdat, NR_FILE_DIRTY)),
4329 K(node_page_state(pgdat, NR_WRITEBACK)),
4330 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4331 K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
4332 K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
4334 K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
4336 K(node_page_state(pgdat, NR_SHMEM)),
4337 K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
4338 K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
4339 node_page_state(pgdat, NR_PAGES_SCANNED),
4340 !pgdat_reclaimable(pgdat) ? "yes" : "no");
4343 for_each_populated_zone(zone) {
4346 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4350 for_each_online_cpu(cpu)
4351 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4360 " active_anon:%lukB"
4361 " inactive_anon:%lukB"
4362 " active_file:%lukB"
4363 " inactive_file:%lukB"
4364 " unevictable:%lukB"
4365 " writepending:%lukB"
4369 " slab_reclaimable:%lukB"
4370 " slab_unreclaimable:%lukB"
4371 " kernel_stack:%lukB"
4379 K(zone_page_state(zone, NR_FREE_PAGES)),
4380 K(min_wmark_pages(zone)),
4381 K(low_wmark_pages(zone)),
4382 K(high_wmark_pages(zone)),
4383 K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
4384 K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
4385 K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
4386 K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
4387 K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
4388 K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
4389 K(zone->present_pages),
4390 K(zone->managed_pages),
4391 K(zone_page_state(zone, NR_MLOCK)),
4392 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4393 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4394 zone_page_state(zone, NR_KERNEL_STACK_KB),
4395 K(zone_page_state(zone, NR_PAGETABLE)),
4396 K(zone_page_state(zone, NR_BOUNCE)),
4398 K(this_cpu_read(zone->pageset->pcp.count)),
4399 K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
4400 printk("lowmem_reserve[]:");
4401 for (i = 0; i < MAX_NR_ZONES; i++)
4402 printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
4403 printk(KERN_CONT "\n");
4406 for_each_populated_zone(zone) {
4408 unsigned long nr[MAX_ORDER], flags, total = 0;
4409 unsigned char types[MAX_ORDER];
4411 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4414 printk(KERN_CONT "%s: ", zone->name);
4416 spin_lock_irqsave(&zone->lock, flags);
4417 for (order = 0; order < MAX_ORDER; order++) {
4418 struct free_area *area = &zone->free_area[order];
4421 nr[order] = area->nr_free;
4422 total += nr[order] << order;
4425 for (type = 0; type < MIGRATE_TYPES; type++) {
4426 if (!list_empty(&area->free_list[type]))
4427 types[order] |= 1 << type;
4430 spin_unlock_irqrestore(&zone->lock, flags);
4431 for (order = 0; order < MAX_ORDER; order++) {
4432 printk(KERN_CONT "%lu*%lukB ",
4433 nr[order], K(1UL) << order);
4435 show_migration_types(types[order]);
4437 printk(KERN_CONT "= %lukB\n", K(total));
4440 hugetlb_show_meminfo();
4442 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
4444 show_swap_cache_info();
4447 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4449 zoneref->zone = zone;
4450 zoneref->zone_idx = zone_idx(zone);
4454 * Builds allocation fallback zone lists.
4456 * Add all populated zones of a node to the zonelist.
4458 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4462 enum zone_type zone_type = MAX_NR_ZONES;
4466 zone = pgdat->node_zones + zone_type;
4467 if (managed_zone(zone)) {
4468 zoneref_set_zone(zone,
4469 &zonelist->_zonerefs[nr_zones++]);
4470 check_highest_zone(zone_type);
4472 } while (zone_type);
4480 * 0 = automatic detection of better ordering.
4481 * 1 = order by ([node] distance, -zonetype)
4482 * 2 = order by (-zonetype, [node] distance)
4484 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4485 * the same zonelist. So only NUMA can configure this param.
4487 #define ZONELIST_ORDER_DEFAULT 0
4488 #define ZONELIST_ORDER_NODE 1
4489 #define ZONELIST_ORDER_ZONE 2
4491 /* zonelist order in the kernel.
4492 * set_zonelist_order() will set this to NODE or ZONE.
4494 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4495 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4499 /* The value user specified ....changed by config */
4500 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4501 /* string for sysctl */
4502 #define NUMA_ZONELIST_ORDER_LEN 16
4503 char numa_zonelist_order[16] = "default";
4506 * interface for configure zonelist ordering.
4507 * command line option "numa_zonelist_order"
4508 * = "[dD]efault - default, automatic configuration.
4509 * = "[nN]ode - order by node locality, then by zone within node
4510 * = "[zZ]one - order by zone, then by locality within zone
4513 static int __parse_numa_zonelist_order(char *s)
4515 if (*s == 'd' || *s == 'D') {
4516 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4517 } else if (*s == 'n' || *s == 'N') {
4518 user_zonelist_order = ZONELIST_ORDER_NODE;
4519 } else if (*s == 'z' || *s == 'Z') {
4520 user_zonelist_order = ZONELIST_ORDER_ZONE;
4522 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4528 static __init int setup_numa_zonelist_order(char *s)
4535 ret = __parse_numa_zonelist_order(s);
4537 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4541 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4544 * sysctl handler for numa_zonelist_order
4546 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4547 void __user *buffer, size_t *length,
4550 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4552 static DEFINE_MUTEX(zl_order_mutex);
4554 mutex_lock(&zl_order_mutex);
4556 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4560 strcpy(saved_string, (char *)table->data);
4562 ret = proc_dostring(table, write, buffer, length, ppos);
4566 int oldval = user_zonelist_order;
4568 ret = __parse_numa_zonelist_order((char *)table->data);
4571 * bogus value. restore saved string
4573 strncpy((char *)table->data, saved_string,
4574 NUMA_ZONELIST_ORDER_LEN);
4575 user_zonelist_order = oldval;
4576 } else if (oldval != user_zonelist_order) {
4577 mutex_lock(&zonelists_mutex);
4578 build_all_zonelists(NULL, NULL);
4579 mutex_unlock(&zonelists_mutex);
4583 mutex_unlock(&zl_order_mutex);
4588 #define MAX_NODE_LOAD (nr_online_nodes)
4589 static int node_load[MAX_NUMNODES];
4592 * find_next_best_node - find the next node that should appear in a given node's fallback list
4593 * @node: node whose fallback list we're appending
4594 * @used_node_mask: nodemask_t of already used nodes
4596 * We use a number of factors to determine which is the next node that should
4597 * appear on a given node's fallback list. The node should not have appeared
4598 * already in @node's fallback list, and it should be the next closest node
4599 * according to the distance array (which contains arbitrary distance values
4600 * from each node to each node in the system), and should also prefer nodes
4601 * with no CPUs, since presumably they'll have very little allocation pressure
4602 * on them otherwise.
4603 * It returns -1 if no node is found.
4605 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4608 int min_val = INT_MAX;
4609 int best_node = NUMA_NO_NODE;
4610 const struct cpumask *tmp = cpumask_of_node(0);
4612 /* Use the local node if we haven't already */
4613 if (!node_isset(node, *used_node_mask)) {
4614 node_set(node, *used_node_mask);
4618 for_each_node_state(n, N_MEMORY) {
4620 /* Don't want a node to appear more than once */
4621 if (node_isset(n, *used_node_mask))
4624 /* Use the distance array to find the distance */
4625 val = node_distance(node, n);
4627 /* Penalize nodes under us ("prefer the next node") */
4630 /* Give preference to headless and unused nodes */
4631 tmp = cpumask_of_node(n);
4632 if (!cpumask_empty(tmp))
4633 val += PENALTY_FOR_NODE_WITH_CPUS;
4635 /* Slight preference for less loaded node */
4636 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4637 val += node_load[n];
4639 if (val < min_val) {
4646 node_set(best_node, *used_node_mask);
4653 * Build zonelists ordered by node and zones within node.
4654 * This results in maximum locality--normal zone overflows into local
4655 * DMA zone, if any--but risks exhausting DMA zone.
4657 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4660 struct zonelist *zonelist;
4662 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4663 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4665 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4666 zonelist->_zonerefs[j].zone = NULL;
4667 zonelist->_zonerefs[j].zone_idx = 0;
4671 * Build gfp_thisnode zonelists
4673 static void build_thisnode_zonelists(pg_data_t *pgdat)
4676 struct zonelist *zonelist;
4678 zonelist = &pgdat->node_zonelists[ZONELIST_NOFALLBACK];
4679 j = build_zonelists_node(pgdat, zonelist, 0);
4680 zonelist->_zonerefs[j].zone = NULL;
4681 zonelist->_zonerefs[j].zone_idx = 0;
4685 * Build zonelists ordered by zone and nodes within zones.
4686 * This results in conserving DMA zone[s] until all Normal memory is
4687 * exhausted, but results in overflowing to remote node while memory
4688 * may still exist in local DMA zone.
4690 static int node_order[MAX_NUMNODES];
4692 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4695 int zone_type; /* needs to be signed */
4697 struct zonelist *zonelist;
4699 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4701 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4702 for (j = 0; j < nr_nodes; j++) {
4703 node = node_order[j];
4704 z = &NODE_DATA(node)->node_zones[zone_type];
4705 if (managed_zone(z)) {
4707 &zonelist->_zonerefs[pos++]);
4708 check_highest_zone(zone_type);
4712 zonelist->_zonerefs[pos].zone = NULL;
4713 zonelist->_zonerefs[pos].zone_idx = 0;
4716 #if defined(CONFIG_64BIT)
4718 * Devices that require DMA32/DMA are relatively rare and do not justify a
4719 * penalty to every machine in case the specialised case applies. Default
4720 * to Node-ordering on 64-bit NUMA machines
4722 static int default_zonelist_order(void)
4724 return ZONELIST_ORDER_NODE;
4728 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4729 * by the kernel. If processes running on node 0 deplete the low memory zone
4730 * then reclaim will occur more frequency increasing stalls and potentially
4731 * be easier to OOM if a large percentage of the zone is under writeback or
4732 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4733 * Hence, default to zone ordering on 32-bit.
4735 static int default_zonelist_order(void)
4737 return ZONELIST_ORDER_ZONE;
4739 #endif /* CONFIG_64BIT */
4741 static void set_zonelist_order(void)
4743 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4744 current_zonelist_order = default_zonelist_order();
4746 current_zonelist_order = user_zonelist_order;
4749 static void build_zonelists(pg_data_t *pgdat)
4752 nodemask_t used_mask;
4753 int local_node, prev_node;
4754 struct zonelist *zonelist;
4755 unsigned int order = current_zonelist_order;
4757 /* initialize zonelists */
4758 for (i = 0; i < MAX_ZONELISTS; i++) {
4759 zonelist = pgdat->node_zonelists + i;
4760 zonelist->_zonerefs[0].zone = NULL;
4761 zonelist->_zonerefs[0].zone_idx = 0;
4764 /* NUMA-aware ordering of nodes */
4765 local_node = pgdat->node_id;
4766 load = nr_online_nodes;
4767 prev_node = local_node;
4768 nodes_clear(used_mask);
4770 memset(node_order, 0, sizeof(node_order));
4773 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4775 * We don't want to pressure a particular node.
4776 * So adding penalty to the first node in same
4777 * distance group to make it round-robin.
4779 if (node_distance(local_node, node) !=
4780 node_distance(local_node, prev_node))
4781 node_load[node] = load;
4785 if (order == ZONELIST_ORDER_NODE)
4786 build_zonelists_in_node_order(pgdat, node);
4788 node_order[i++] = node; /* remember order */
4791 if (order == ZONELIST_ORDER_ZONE) {
4792 /* calculate node order -- i.e., DMA last! */
4793 build_zonelists_in_zone_order(pgdat, i);
4796 build_thisnode_zonelists(pgdat);
4799 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4801 * Return node id of node used for "local" allocations.
4802 * I.e., first node id of first zone in arg node's generic zonelist.
4803 * Used for initializing percpu 'numa_mem', which is used primarily
4804 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4806 int local_memory_node(int node)
4810 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4811 gfp_zone(GFP_KERNEL),
4813 return z->zone->node;
4817 static void setup_min_unmapped_ratio(void);
4818 static void setup_min_slab_ratio(void);
4819 #else /* CONFIG_NUMA */
4821 static void set_zonelist_order(void)
4823 current_zonelist_order = ZONELIST_ORDER_ZONE;
4826 static void build_zonelists(pg_data_t *pgdat)
4828 int node, local_node;
4830 struct zonelist *zonelist;
4832 local_node = pgdat->node_id;
4834 zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
4835 j = build_zonelists_node(pgdat, zonelist, 0);
4838 * Now we build the zonelist so that it contains the zones
4839 * of all the other nodes.
4840 * We don't want to pressure a particular node, so when
4841 * building the zones for node N, we make sure that the
4842 * zones coming right after the local ones are those from
4843 * node N+1 (modulo N)
4845 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4846 if (!node_online(node))
4848 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4850 for (node = 0; node < local_node; node++) {
4851 if (!node_online(node))
4853 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4856 zonelist->_zonerefs[j].zone = NULL;
4857 zonelist->_zonerefs[j].zone_idx = 0;
4860 #endif /* CONFIG_NUMA */
4863 * Boot pageset table. One per cpu which is going to be used for all
4864 * zones and all nodes. The parameters will be set in such a way
4865 * that an item put on a list will immediately be handed over to
4866 * the buddy list. This is safe since pageset manipulation is done
4867 * with interrupts disabled.
4869 * The boot_pagesets must be kept even after bootup is complete for
4870 * unused processors and/or zones. They do play a role for bootstrapping
4871 * hotplugged processors.
4873 * zoneinfo_show() and maybe other functions do
4874 * not check if the processor is online before following the pageset pointer.
4875 * Other parts of the kernel may not check if the zone is available.
4877 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4878 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4879 static void setup_zone_pageset(struct zone *zone);
4882 * Global mutex to protect against size modification of zonelists
4883 * as well as to serialize pageset setup for the new populated zone.
4885 DEFINE_MUTEX(zonelists_mutex);
4887 /* return values int ....just for stop_machine() */
4888 static int __build_all_zonelists(void *data)
4892 pg_data_t *self = data;
4895 memset(node_load, 0, sizeof(node_load));
4898 if (self && !node_online(self->node_id)) {
4899 build_zonelists(self);
4902 for_each_online_node(nid) {
4903 pg_data_t *pgdat = NODE_DATA(nid);
4905 build_zonelists(pgdat);
4909 * Initialize the boot_pagesets that are going to be used
4910 * for bootstrapping processors. The real pagesets for
4911 * each zone will be allocated later when the per cpu
4912 * allocator is available.
4914 * boot_pagesets are used also for bootstrapping offline
4915 * cpus if the system is already booted because the pagesets
4916 * are needed to initialize allocators on a specific cpu too.
4917 * F.e. the percpu allocator needs the page allocator which
4918 * needs the percpu allocator in order to allocate its pagesets
4919 * (a chicken-egg dilemma).
4921 for_each_possible_cpu(cpu) {
4922 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4924 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4926 * We now know the "local memory node" for each node--
4927 * i.e., the node of the first zone in the generic zonelist.
4928 * Set up numa_mem percpu variable for on-line cpus. During
4929 * boot, only the boot cpu should be on-line; we'll init the
4930 * secondary cpus' numa_mem as they come on-line. During
4931 * node/memory hotplug, we'll fixup all on-line cpus.
4933 if (cpu_online(cpu))
4934 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4941 static noinline void __init
4942 build_all_zonelists_init(void)
4944 __build_all_zonelists(NULL);
4945 mminit_verify_zonelist();
4946 cpuset_init_current_mems_allowed();
4950 * Called with zonelists_mutex held always
4951 * unless system_state == SYSTEM_BOOTING.
4953 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4954 * [we're only called with non-NULL zone through __meminit paths] and
4955 * (2) call of __init annotated helper build_all_zonelists_init
4956 * [protected by SYSTEM_BOOTING].
4958 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4960 set_zonelist_order();
4962 if (system_state == SYSTEM_BOOTING) {
4963 build_all_zonelists_init();
4965 #ifdef CONFIG_MEMORY_HOTPLUG
4967 setup_zone_pageset(zone);
4969 /* we have to stop all cpus to guarantee there is no user
4971 stop_machine(__build_all_zonelists, pgdat, NULL);
4972 /* cpuset refresh routine should be here */
4974 vm_total_pages = nr_free_pagecache_pages();
4976 * Disable grouping by mobility if the number of pages in the
4977 * system is too low to allow the mechanism to work. It would be
4978 * more accurate, but expensive to check per-zone. This check is
4979 * made on memory-hotadd so a system can start with mobility
4980 * disabled and enable it later
4982 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4983 page_group_by_mobility_disabled = 1;
4985 page_group_by_mobility_disabled = 0;
4987 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4989 zonelist_order_name[current_zonelist_order],
4990 page_group_by_mobility_disabled ? "off" : "on",
4993 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4998 * Initially all pages are reserved - free ones are freed
4999 * up by free_all_bootmem() once the early boot process is
5000 * done. Non-atomic initialization, single-pass.
5002 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
5003 unsigned long start_pfn, enum memmap_context context)
5005 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
5006 unsigned long end_pfn = start_pfn + size;
5007 pg_data_t *pgdat = NODE_DATA(nid);
5009 unsigned long nr_initialised = 0;
5010 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5011 struct memblock_region *r = NULL, *tmp;
5014 if (highest_memmap_pfn < end_pfn - 1)
5015 highest_memmap_pfn = end_pfn - 1;
5018 * Honor reservation requested by the driver for this ZONE_DEVICE
5021 if (altmap && start_pfn == altmap->base_pfn)
5022 start_pfn += altmap->reserve;
5024 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
5026 * There can be holes in boot-time mem_map[]s handed to this
5027 * function. They do not exist on hotplugged memory.
5029 if (context != MEMMAP_EARLY)
5032 if (!early_pfn_valid(pfn))
5034 if (!early_pfn_in_nid(pfn, nid))
5036 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
5039 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5041 * Check given memblock attribute by firmware which can affect
5042 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5043 * mirrored, it's an overlapped memmap init. skip it.
5045 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
5046 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
5047 for_each_memblock(memory, tmp)
5048 if (pfn < memblock_region_memory_end_pfn(tmp))
5052 if (pfn >= memblock_region_memory_base_pfn(r) &&
5053 memblock_is_mirror(r)) {
5054 /* already initialized as NORMAL */
5055 pfn = memblock_region_memory_end_pfn(r);
5063 * Mark the block movable so that blocks are reserved for
5064 * movable at startup. This will force kernel allocations
5065 * to reserve their blocks rather than leaking throughout
5066 * the address space during boot when many long-lived
5067 * kernel allocations are made.
5069 * bitmap is created for zone's valid pfn range. but memmap
5070 * can be created for invalid pages (for alignment)
5071 * check here not to call set_pageblock_migratetype() against
5074 if (!(pfn & (pageblock_nr_pages - 1))) {
5075 struct page *page = pfn_to_page(pfn);
5077 __init_single_page(page, pfn, zone, nid);
5078 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5080 __init_single_pfn(pfn, zone, nid);
5085 static void __meminit zone_init_free_lists(struct zone *zone)
5087 unsigned int order, t;
5088 for_each_migratetype_order(order, t) {
5089 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5090 zone->free_area[order].nr_free = 0;
5094 #ifndef __HAVE_ARCH_MEMMAP_INIT
5095 #define memmap_init(size, nid, zone, start_pfn) \
5096 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5099 static int zone_batchsize(struct zone *zone)
5105 * The per-cpu-pages pools are set to around 1000th of the
5106 * size of the zone. But no more than 1/2 of a meg.
5108 * OK, so we don't know how big the cache is. So guess.
5110 batch = zone->managed_pages / 1024;
5111 if (batch * PAGE_SIZE > 512 * 1024)
5112 batch = (512 * 1024) / PAGE_SIZE;
5113 batch /= 4; /* We effectively *= 4 below */
5118 * Clamp the batch to a 2^n - 1 value. Having a power
5119 * of 2 value was found to be more likely to have
5120 * suboptimal cache aliasing properties in some cases.
5122 * For example if 2 tasks are alternately allocating
5123 * batches of pages, one task can end up with a lot
5124 * of pages of one half of the possible page colors
5125 * and the other with pages of the other colors.
5127 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5132 /* The deferral and batching of frees should be suppressed under NOMMU
5135 * The problem is that NOMMU needs to be able to allocate large chunks
5136 * of contiguous memory as there's no hardware page translation to
5137 * assemble apparent contiguous memory from discontiguous pages.
5139 * Queueing large contiguous runs of pages for batching, however,
5140 * causes the pages to actually be freed in smaller chunks. As there
5141 * can be a significant delay between the individual batches being
5142 * recycled, this leads to the once large chunks of space being
5143 * fragmented and becoming unavailable for high-order allocations.
5150 * pcp->high and pcp->batch values are related and dependent on one another:
5151 * ->batch must never be higher then ->high.
5152 * The following function updates them in a safe manner without read side
5155 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5156 * those fields changing asynchronously (acording the the above rule).
5158 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5159 * outside of boot time (or some other assurance that no concurrent updaters
5162 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5163 unsigned long batch)
5165 /* start with a fail safe value for batch */
5169 /* Update high, then batch, in order */
5176 /* a companion to pageset_set_high() */
5177 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5179 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5182 static void pageset_init(struct per_cpu_pageset *p)
5184 struct per_cpu_pages *pcp;
5187 memset(p, 0, sizeof(*p));
5191 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5192 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5195 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5198 pageset_set_batch(p, batch);
5202 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5203 * to the value high for the pageset p.
5205 static void pageset_set_high(struct per_cpu_pageset *p,
5208 unsigned long batch = max(1UL, high / 4);
5209 if ((high / 4) > (PAGE_SHIFT * 8))
5210 batch = PAGE_SHIFT * 8;
5212 pageset_update(&p->pcp, high, batch);
5215 static void pageset_set_high_and_batch(struct zone *zone,
5216 struct per_cpu_pageset *pcp)
5218 if (percpu_pagelist_fraction)
5219 pageset_set_high(pcp,
5220 (zone->managed_pages /
5221 percpu_pagelist_fraction));
5223 pageset_set_batch(pcp, zone_batchsize(zone));
5226 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5228 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5231 pageset_set_high_and_batch(zone, pcp);
5234 static void __meminit setup_zone_pageset(struct zone *zone)
5237 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5238 for_each_possible_cpu(cpu)
5239 zone_pageset_init(zone, cpu);
5243 * Allocate per cpu pagesets and initialize them.
5244 * Before this call only boot pagesets were available.
5246 void __init setup_per_cpu_pageset(void)
5248 struct pglist_data *pgdat;
5251 for_each_populated_zone(zone)
5252 setup_zone_pageset(zone);
5254 for_each_online_pgdat(pgdat)
5255 pgdat->per_cpu_nodestats =
5256 alloc_percpu(struct per_cpu_nodestat);
5259 static __meminit void zone_pcp_init(struct zone *zone)
5262 * per cpu subsystem is not up at this point. The following code
5263 * relies on the ability of the linker to provide the
5264 * offset of a (static) per cpu variable into the per cpu area.
5266 zone->pageset = &boot_pageset;
5268 if (populated_zone(zone))
5269 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5270 zone->name, zone->present_pages,
5271 zone_batchsize(zone));
5274 int __meminit init_currently_empty_zone(struct zone *zone,
5275 unsigned long zone_start_pfn,
5278 struct pglist_data *pgdat = zone->zone_pgdat;
5280 pgdat->nr_zones = zone_idx(zone) + 1;
5282 zone->zone_start_pfn = zone_start_pfn;
5284 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5285 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5287 (unsigned long)zone_idx(zone),
5288 zone_start_pfn, (zone_start_pfn + size));
5290 zone_init_free_lists(zone);
5291 zone->initialized = 1;
5296 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5297 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5300 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5302 int __meminit __early_pfn_to_nid(unsigned long pfn,
5303 struct mminit_pfnnid_cache *state)
5305 unsigned long start_pfn, end_pfn;
5308 if (state->last_start <= pfn && pfn < state->last_end)
5309 return state->last_nid;
5311 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5313 state->last_start = start_pfn;
5314 state->last_end = end_pfn;
5315 state->last_nid = nid;
5320 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5323 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5324 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5325 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5327 * If an architecture guarantees that all ranges registered contain no holes
5328 * and may be freed, this this function may be used instead of calling
5329 * memblock_free_early_nid() manually.
5331 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5333 unsigned long start_pfn, end_pfn;
5336 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5337 start_pfn = min(start_pfn, max_low_pfn);
5338 end_pfn = min(end_pfn, max_low_pfn);
5340 if (start_pfn < end_pfn)
5341 memblock_free_early_nid(PFN_PHYS(start_pfn),
5342 (end_pfn - start_pfn) << PAGE_SHIFT,
5348 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5349 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5351 * If an architecture guarantees that all ranges registered contain no holes and may
5352 * be freed, this function may be used instead of calling memory_present() manually.
5354 void __init sparse_memory_present_with_active_regions(int nid)
5356 unsigned long start_pfn, end_pfn;
5359 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5360 memory_present(this_nid, start_pfn, end_pfn);
5364 * get_pfn_range_for_nid - Return the start and end page frames for a node
5365 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5366 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5367 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5369 * It returns the start and end page frame of a node based on information
5370 * provided by memblock_set_node(). If called for a node
5371 * with no available memory, a warning is printed and the start and end
5374 void __meminit get_pfn_range_for_nid(unsigned int nid,
5375 unsigned long *start_pfn, unsigned long *end_pfn)
5377 unsigned long this_start_pfn, this_end_pfn;
5383 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5384 *start_pfn = min(*start_pfn, this_start_pfn);
5385 *end_pfn = max(*end_pfn, this_end_pfn);
5388 if (*start_pfn == -1UL)
5393 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5394 * assumption is made that zones within a node are ordered in monotonic
5395 * increasing memory addresses so that the "highest" populated zone is used
5397 static void __init find_usable_zone_for_movable(void)
5400 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5401 if (zone_index == ZONE_MOVABLE)
5404 if (arch_zone_highest_possible_pfn[zone_index] >
5405 arch_zone_lowest_possible_pfn[zone_index])
5409 VM_BUG_ON(zone_index == -1);
5410 movable_zone = zone_index;
5414 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5415 * because it is sized independent of architecture. Unlike the other zones,
5416 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5417 * in each node depending on the size of each node and how evenly kernelcore
5418 * is distributed. This helper function adjusts the zone ranges
5419 * provided by the architecture for a given node by using the end of the
5420 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5421 * zones within a node are in order of monotonic increases memory addresses
5423 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5424 unsigned long zone_type,
5425 unsigned long node_start_pfn,
5426 unsigned long node_end_pfn,
5427 unsigned long *zone_start_pfn,
5428 unsigned long *zone_end_pfn)
5430 /* Only adjust if ZONE_MOVABLE is on this node */
5431 if (zone_movable_pfn[nid]) {
5432 /* Size ZONE_MOVABLE */
5433 if (zone_type == ZONE_MOVABLE) {
5434 *zone_start_pfn = zone_movable_pfn[nid];
5435 *zone_end_pfn = min(node_end_pfn,
5436 arch_zone_highest_possible_pfn[movable_zone]);
5438 /* Adjust for ZONE_MOVABLE starting within this range */
5439 } else if (!mirrored_kernelcore &&
5440 *zone_start_pfn < zone_movable_pfn[nid] &&
5441 *zone_end_pfn > zone_movable_pfn[nid]) {
5442 *zone_end_pfn = zone_movable_pfn[nid];
5444 /* Check if this whole range is within ZONE_MOVABLE */
5445 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5446 *zone_start_pfn = *zone_end_pfn;
5451 * Return the number of pages a zone spans in a node, including holes
5452 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5454 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5455 unsigned long zone_type,
5456 unsigned long node_start_pfn,
5457 unsigned long node_end_pfn,
5458 unsigned long *zone_start_pfn,
5459 unsigned long *zone_end_pfn,
5460 unsigned long *ignored)
5462 /* When hotadd a new node from cpu_up(), the node should be empty */
5463 if (!node_start_pfn && !node_end_pfn)
5466 /* Get the start and end of the zone */
5467 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5468 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5469 adjust_zone_range_for_zone_movable(nid, zone_type,
5470 node_start_pfn, node_end_pfn,
5471 zone_start_pfn, zone_end_pfn);
5473 /* Check that this node has pages within the zone's required range */
5474 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5477 /* Move the zone boundaries inside the node if necessary */
5478 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5479 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5481 /* Return the spanned pages */
5482 return *zone_end_pfn - *zone_start_pfn;
5486 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5487 * then all holes in the requested range will be accounted for.
5489 unsigned long __meminit __absent_pages_in_range(int nid,
5490 unsigned long range_start_pfn,
5491 unsigned long range_end_pfn)
5493 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5494 unsigned long start_pfn, end_pfn;
5497 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5498 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5499 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5500 nr_absent -= end_pfn - start_pfn;
5506 * absent_pages_in_range - Return number of page frames in holes within a range
5507 * @start_pfn: The start PFN to start searching for holes
5508 * @end_pfn: The end PFN to stop searching for holes
5510 * It returns the number of pages frames in memory holes within a range.
5512 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5513 unsigned long end_pfn)
5515 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5518 /* Return the number of page frames in holes in a zone on a node */
5519 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5520 unsigned long zone_type,
5521 unsigned long node_start_pfn,
5522 unsigned long node_end_pfn,
5523 unsigned long *ignored)
5525 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5526 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5527 unsigned long zone_start_pfn, zone_end_pfn;
5528 unsigned long nr_absent;
5530 /* When hotadd a new node from cpu_up(), the node should be empty */
5531 if (!node_start_pfn && !node_end_pfn)
5534 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5535 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5537 adjust_zone_range_for_zone_movable(nid, zone_type,
5538 node_start_pfn, node_end_pfn,
5539 &zone_start_pfn, &zone_end_pfn);
5540 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5543 * ZONE_MOVABLE handling.
5544 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5547 if (mirrored_kernelcore && zone_movable_pfn[nid]) {
5548 unsigned long start_pfn, end_pfn;
5549 struct memblock_region *r;
5551 for_each_memblock(memory, r) {
5552 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5553 zone_start_pfn, zone_end_pfn);
5554 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5555 zone_start_pfn, zone_end_pfn);
5557 if (zone_type == ZONE_MOVABLE &&
5558 memblock_is_mirror(r))
5559 nr_absent += end_pfn - start_pfn;
5561 if (zone_type == ZONE_NORMAL &&
5562 !memblock_is_mirror(r))
5563 nr_absent += end_pfn - start_pfn;
5570 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5571 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5572 unsigned long zone_type,
5573 unsigned long node_start_pfn,
5574 unsigned long node_end_pfn,
5575 unsigned long *zone_start_pfn,
5576 unsigned long *zone_end_pfn,
5577 unsigned long *zones_size)
5581 *zone_start_pfn = node_start_pfn;
5582 for (zone = 0; zone < zone_type; zone++)
5583 *zone_start_pfn += zones_size[zone];
5585 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5587 return zones_size[zone_type];
5590 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5591 unsigned long zone_type,
5592 unsigned long node_start_pfn,
5593 unsigned long node_end_pfn,
5594 unsigned long *zholes_size)
5599 return zholes_size[zone_type];
5602 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5604 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5605 unsigned long node_start_pfn,
5606 unsigned long node_end_pfn,
5607 unsigned long *zones_size,
5608 unsigned long *zholes_size)
5610 unsigned long realtotalpages = 0, totalpages = 0;
5613 for (i = 0; i < MAX_NR_ZONES; i++) {
5614 struct zone *zone = pgdat->node_zones + i;
5615 unsigned long zone_start_pfn, zone_end_pfn;
5616 unsigned long size, real_size;
5618 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5624 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5625 node_start_pfn, node_end_pfn,
5628 zone->zone_start_pfn = zone_start_pfn;
5630 zone->zone_start_pfn = 0;
5631 zone->spanned_pages = size;
5632 zone->present_pages = real_size;
5635 realtotalpages += real_size;
5638 pgdat->node_spanned_pages = totalpages;
5639 pgdat->node_present_pages = realtotalpages;
5640 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5644 #ifndef CONFIG_SPARSEMEM
5646 * Calculate the size of the zone->blockflags rounded to an unsigned long
5647 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5648 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5649 * round what is now in bits to nearest long in bits, then return it in
5652 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5654 unsigned long usemapsize;
5656 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5657 usemapsize = roundup(zonesize, pageblock_nr_pages);
5658 usemapsize = usemapsize >> pageblock_order;
5659 usemapsize *= NR_PAGEBLOCK_BITS;
5660 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5662 return usemapsize / 8;
5665 static void __init setup_usemap(struct pglist_data *pgdat,
5667 unsigned long zone_start_pfn,
5668 unsigned long zonesize)
5670 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5671 zone->pageblock_flags = NULL;
5673 zone->pageblock_flags =
5674 memblock_virt_alloc_node_nopanic(usemapsize,
5678 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5679 unsigned long zone_start_pfn, unsigned long zonesize) {}
5680 #endif /* CONFIG_SPARSEMEM */
5682 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5684 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5685 void __paginginit set_pageblock_order(void)
5689 /* Check that pageblock_nr_pages has not already been setup */
5690 if (pageblock_order)
5693 if (HPAGE_SHIFT > PAGE_SHIFT)
5694 order = HUGETLB_PAGE_ORDER;
5696 order = MAX_ORDER - 1;
5699 * Assume the largest contiguous order of interest is a huge page.
5700 * This value may be variable depending on boot parameters on IA64 and
5703 pageblock_order = order;
5705 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5708 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5709 * is unused as pageblock_order is set at compile-time. See
5710 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5713 void __paginginit set_pageblock_order(void)
5717 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5719 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5720 unsigned long present_pages)
5722 unsigned long pages = spanned_pages;
5725 * Provide a more accurate estimation if there are holes within
5726 * the zone and SPARSEMEM is in use. If there are holes within the
5727 * zone, each populated memory region may cost us one or two extra
5728 * memmap pages due to alignment because memmap pages for each
5729 * populated regions may not naturally algined on page boundary.
5730 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5732 if (spanned_pages > present_pages + (present_pages >> 4) &&
5733 IS_ENABLED(CONFIG_SPARSEMEM))
5734 pages = present_pages;
5736 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5740 * Set up the zone data structures:
5741 * - mark all pages reserved
5742 * - mark all memory queues empty
5743 * - clear the memory bitmaps
5745 * NOTE: pgdat should get zeroed by caller.
5747 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5750 int nid = pgdat->node_id;
5753 pgdat_resize_init(pgdat);
5754 #ifdef CONFIG_NUMA_BALANCING
5755 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5756 pgdat->numabalancing_migrate_nr_pages = 0;
5757 pgdat->numabalancing_migrate_next_window = jiffies;
5759 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5760 spin_lock_init(&pgdat->split_queue_lock);
5761 INIT_LIST_HEAD(&pgdat->split_queue);
5762 pgdat->split_queue_len = 0;
5764 init_waitqueue_head(&pgdat->kswapd_wait);
5765 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5766 #ifdef CONFIG_COMPACTION
5767 init_waitqueue_head(&pgdat->kcompactd_wait);
5769 pgdat_page_ext_init(pgdat);
5770 spin_lock_init(&pgdat->lru_lock);
5771 lruvec_init(node_lruvec(pgdat));
5773 for (j = 0; j < MAX_NR_ZONES; j++) {
5774 struct zone *zone = pgdat->node_zones + j;
5775 unsigned long size, realsize, freesize, memmap_pages;
5776 unsigned long zone_start_pfn = zone->zone_start_pfn;
5778 size = zone->spanned_pages;
5779 realsize = freesize = zone->present_pages;
5782 * Adjust freesize so that it accounts for how much memory
5783 * is used by this zone for memmap. This affects the watermark
5784 * and per-cpu initialisations
5786 memmap_pages = calc_memmap_size(size, realsize);
5787 if (!is_highmem_idx(j)) {
5788 if (freesize >= memmap_pages) {
5789 freesize -= memmap_pages;
5792 " %s zone: %lu pages used for memmap\n",
5793 zone_names[j], memmap_pages);
5795 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5796 zone_names[j], memmap_pages, freesize);
5799 /* Account for reserved pages */
5800 if (j == 0 && freesize > dma_reserve) {
5801 freesize -= dma_reserve;
5802 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5803 zone_names[0], dma_reserve);
5806 if (!is_highmem_idx(j))
5807 nr_kernel_pages += freesize;
5808 /* Charge for highmem memmap if there are enough kernel pages */
5809 else if (nr_kernel_pages > memmap_pages * 2)
5810 nr_kernel_pages -= memmap_pages;
5811 nr_all_pages += freesize;
5814 * Set an approximate value for lowmem here, it will be adjusted
5815 * when the bootmem allocator frees pages into the buddy system.
5816 * And all highmem pages will be managed by the buddy system.
5818 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5822 zone->name = zone_names[j];
5823 zone->zone_pgdat = pgdat;
5824 spin_lock_init(&zone->lock);
5825 zone_seqlock_init(zone);
5826 zone_pcp_init(zone);
5831 set_pageblock_order();
5832 setup_usemap(pgdat, zone, zone_start_pfn, size);
5833 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5835 memmap_init(size, nid, j, zone_start_pfn);
5839 static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
5841 unsigned long __maybe_unused start = 0;
5842 unsigned long __maybe_unused offset = 0;
5844 /* Skip empty nodes */
5845 if (!pgdat->node_spanned_pages)
5848 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5849 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5850 offset = pgdat->node_start_pfn - start;
5851 /* ia64 gets its own node_mem_map, before this, without bootmem */
5852 if (!pgdat->node_mem_map) {
5853 unsigned long size, end;
5857 * The zone's endpoints aren't required to be MAX_ORDER
5858 * aligned but the node_mem_map endpoints must be in order
5859 * for the buddy allocator to function correctly.
5861 end = pgdat_end_pfn(pgdat);
5862 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5863 size = (end - start) * sizeof(struct page);
5864 map = alloc_remap(pgdat->node_id, size);
5866 map = memblock_virt_alloc_node_nopanic(size,
5868 pgdat->node_mem_map = map + offset;
5870 #ifndef CONFIG_NEED_MULTIPLE_NODES
5872 * With no DISCONTIG, the global mem_map is just set as node 0's
5874 if (pgdat == NODE_DATA(0)) {
5875 mem_map = NODE_DATA(0)->node_mem_map;
5876 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5877 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5879 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5882 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5885 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5886 unsigned long node_start_pfn, unsigned long *zholes_size)
5888 pg_data_t *pgdat = NODE_DATA(nid);
5889 unsigned long start_pfn = 0;
5890 unsigned long end_pfn = 0;
5892 /* pg_data_t should be reset to zero when it's allocated */
5893 WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
5895 reset_deferred_meminit(pgdat);
5896 pgdat->node_id = nid;
5897 pgdat->node_start_pfn = node_start_pfn;
5898 pgdat->per_cpu_nodestats = NULL;
5899 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5900 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5901 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5902 (u64)start_pfn << PAGE_SHIFT,
5903 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5905 start_pfn = node_start_pfn;
5907 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5908 zones_size, zholes_size);
5910 alloc_node_mem_map(pgdat);
5911 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5912 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5913 nid, (unsigned long)pgdat,
5914 (unsigned long)pgdat->node_mem_map);
5917 free_area_init_core(pgdat);
5920 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5922 #if MAX_NUMNODES > 1
5924 * Figure out the number of possible node ids.
5926 void __init setup_nr_node_ids(void)
5928 unsigned int highest;
5930 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5931 nr_node_ids = highest + 1;
5936 * node_map_pfn_alignment - determine the maximum internode alignment
5938 * This function should be called after node map is populated and sorted.
5939 * It calculates the maximum power of two alignment which can distinguish
5942 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5943 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5944 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5945 * shifted, 1GiB is enough and this function will indicate so.
5947 * This is used to test whether pfn -> nid mapping of the chosen memory
5948 * model has fine enough granularity to avoid incorrect mapping for the
5949 * populated node map.
5951 * Returns the determined alignment in pfn's. 0 if there is no alignment
5952 * requirement (single node).
5954 unsigned long __init node_map_pfn_alignment(void)
5956 unsigned long accl_mask = 0, last_end = 0;
5957 unsigned long start, end, mask;
5961 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5962 if (!start || last_nid < 0 || last_nid == nid) {
5969 * Start with a mask granular enough to pin-point to the
5970 * start pfn and tick off bits one-by-one until it becomes
5971 * too coarse to separate the current node from the last.
5973 mask = ~((1 << __ffs(start)) - 1);
5974 while (mask && last_end <= (start & (mask << 1)))
5977 /* accumulate all internode masks */
5981 /* convert mask to number of pages */
5982 return ~accl_mask + 1;
5985 /* Find the lowest pfn for a node */
5986 static unsigned long __init find_min_pfn_for_node(int nid)
5988 unsigned long min_pfn = ULONG_MAX;
5989 unsigned long start_pfn;
5992 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5993 min_pfn = min(min_pfn, start_pfn);
5995 if (min_pfn == ULONG_MAX) {
5996 pr_warn("Could not find start_pfn for node %d\n", nid);
6004 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6006 * It returns the minimum PFN based on information provided via
6007 * memblock_set_node().
6009 unsigned long __init find_min_pfn_with_active_regions(void)
6011 return find_min_pfn_for_node(MAX_NUMNODES);
6015 * early_calculate_totalpages()
6016 * Sum pages in active regions for movable zone.
6017 * Populate N_MEMORY for calculating usable_nodes.
6019 static unsigned long __init early_calculate_totalpages(void)
6021 unsigned long totalpages = 0;
6022 unsigned long start_pfn, end_pfn;
6025 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
6026 unsigned long pages = end_pfn - start_pfn;
6028 totalpages += pages;
6030 node_set_state(nid, N_MEMORY);
6036 * Find the PFN the Movable zone begins in each node. Kernel memory
6037 * is spread evenly between nodes as long as the nodes have enough
6038 * memory. When they don't, some nodes will have more kernelcore than
6041 static void __init find_zone_movable_pfns_for_nodes(void)
6044 unsigned long usable_startpfn;
6045 unsigned long kernelcore_node, kernelcore_remaining;
6046 /* save the state before borrow the nodemask */
6047 nodemask_t saved_node_state = node_states[N_MEMORY];
6048 unsigned long totalpages = early_calculate_totalpages();
6049 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6050 struct memblock_region *r;
6052 /* Need to find movable_zone earlier when movable_node is specified. */
6053 find_usable_zone_for_movable();
6056 * If movable_node is specified, ignore kernelcore and movablecore
6059 if (movable_node_is_enabled()) {
6060 for_each_memblock(memory, r) {
6061 if (!memblock_is_hotpluggable(r))
6066 usable_startpfn = PFN_DOWN(r->base);
6067 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6068 min(usable_startpfn, zone_movable_pfn[nid]) :
6076 * If kernelcore=mirror is specified, ignore movablecore option
6078 if (mirrored_kernelcore) {
6079 bool mem_below_4gb_not_mirrored = false;
6081 for_each_memblock(memory, r) {
6082 if (memblock_is_mirror(r))
6087 usable_startpfn = memblock_region_memory_base_pfn(r);
6089 if (usable_startpfn < 0x100000) {
6090 mem_below_4gb_not_mirrored = true;
6094 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6095 min(usable_startpfn, zone_movable_pfn[nid]) :
6099 if (mem_below_4gb_not_mirrored)
6100 pr_warn("This configuration results in unmirrored kernel memory.");
6106 * If movablecore=nn[KMG] was specified, calculate what size of
6107 * kernelcore that corresponds so that memory usable for
6108 * any allocation type is evenly spread. If both kernelcore
6109 * and movablecore are specified, then the value of kernelcore
6110 * will be used for required_kernelcore if it's greater than
6111 * what movablecore would have allowed.
6113 if (required_movablecore) {
6114 unsigned long corepages;
6117 * Round-up so that ZONE_MOVABLE is at least as large as what
6118 * was requested by the user
6120 required_movablecore =
6121 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6122 required_movablecore = min(totalpages, required_movablecore);
6123 corepages = totalpages - required_movablecore;
6125 required_kernelcore = max(required_kernelcore, corepages);
6129 * If kernelcore was not specified or kernelcore size is larger
6130 * than totalpages, there is no ZONE_MOVABLE.
6132 if (!required_kernelcore || required_kernelcore >= totalpages)
6135 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6136 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6139 /* Spread kernelcore memory as evenly as possible throughout nodes */
6140 kernelcore_node = required_kernelcore / usable_nodes;
6141 for_each_node_state(nid, N_MEMORY) {
6142 unsigned long start_pfn, end_pfn;
6145 * Recalculate kernelcore_node if the division per node
6146 * now exceeds what is necessary to satisfy the requested
6147 * amount of memory for the kernel
6149 if (required_kernelcore < kernelcore_node)
6150 kernelcore_node = required_kernelcore / usable_nodes;
6153 * As the map is walked, we track how much memory is usable
6154 * by the kernel using kernelcore_remaining. When it is
6155 * 0, the rest of the node is usable by ZONE_MOVABLE
6157 kernelcore_remaining = kernelcore_node;
6159 /* Go through each range of PFNs within this node */
6160 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6161 unsigned long size_pages;
6163 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6164 if (start_pfn >= end_pfn)
6167 /* Account for what is only usable for kernelcore */
6168 if (start_pfn < usable_startpfn) {
6169 unsigned long kernel_pages;
6170 kernel_pages = min(end_pfn, usable_startpfn)
6173 kernelcore_remaining -= min(kernel_pages,
6174 kernelcore_remaining);
6175 required_kernelcore -= min(kernel_pages,
6176 required_kernelcore);
6178 /* Continue if range is now fully accounted */
6179 if (end_pfn <= usable_startpfn) {
6182 * Push zone_movable_pfn to the end so
6183 * that if we have to rebalance
6184 * kernelcore across nodes, we will
6185 * not double account here
6187 zone_movable_pfn[nid] = end_pfn;
6190 start_pfn = usable_startpfn;
6194 * The usable PFN range for ZONE_MOVABLE is from
6195 * start_pfn->end_pfn. Calculate size_pages as the
6196 * number of pages used as kernelcore
6198 size_pages = end_pfn - start_pfn;
6199 if (size_pages > kernelcore_remaining)
6200 size_pages = kernelcore_remaining;
6201 zone_movable_pfn[nid] = start_pfn + size_pages;
6204 * Some kernelcore has been met, update counts and
6205 * break if the kernelcore for this node has been
6208 required_kernelcore -= min(required_kernelcore,
6210 kernelcore_remaining -= size_pages;
6211 if (!kernelcore_remaining)
6217 * If there is still required_kernelcore, we do another pass with one
6218 * less node in the count. This will push zone_movable_pfn[nid] further
6219 * along on the nodes that still have memory until kernelcore is
6223 if (usable_nodes && required_kernelcore > usable_nodes)
6227 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6228 for (nid = 0; nid < MAX_NUMNODES; nid++)
6229 zone_movable_pfn[nid] =
6230 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6233 /* restore the node_state */
6234 node_states[N_MEMORY] = saved_node_state;
6237 /* Any regular or high memory on that node ? */
6238 static void check_for_memory(pg_data_t *pgdat, int nid)
6240 enum zone_type zone_type;
6242 if (N_MEMORY == N_NORMAL_MEMORY)
6245 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6246 struct zone *zone = &pgdat->node_zones[zone_type];
6247 if (populated_zone(zone)) {
6248 node_set_state(nid, N_HIGH_MEMORY);
6249 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6250 zone_type <= ZONE_NORMAL)
6251 node_set_state(nid, N_NORMAL_MEMORY);
6258 * free_area_init_nodes - Initialise all pg_data_t and zone data
6259 * @max_zone_pfn: an array of max PFNs for each zone
6261 * This will call free_area_init_node() for each active node in the system.
6262 * Using the page ranges provided by memblock_set_node(), the size of each
6263 * zone in each node and their holes is calculated. If the maximum PFN
6264 * between two adjacent zones match, it is assumed that the zone is empty.
6265 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6266 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6267 * starts where the previous one ended. For example, ZONE_DMA32 starts
6268 * at arch_max_dma_pfn.
6270 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6272 unsigned long start_pfn, end_pfn;
6275 /* Record where the zone boundaries are */
6276 memset(arch_zone_lowest_possible_pfn, 0,
6277 sizeof(arch_zone_lowest_possible_pfn));
6278 memset(arch_zone_highest_possible_pfn, 0,
6279 sizeof(arch_zone_highest_possible_pfn));
6281 start_pfn = find_min_pfn_with_active_regions();
6283 for (i = 0; i < MAX_NR_ZONES; i++) {
6284 if (i == ZONE_MOVABLE)
6287 end_pfn = max(max_zone_pfn[i], start_pfn);
6288 arch_zone_lowest_possible_pfn[i] = start_pfn;
6289 arch_zone_highest_possible_pfn[i] = end_pfn;
6291 start_pfn = end_pfn;
6293 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6294 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6296 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6297 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6298 find_zone_movable_pfns_for_nodes();
6300 /* Print out the zone ranges */
6301 pr_info("Zone ranges:\n");
6302 for (i = 0; i < MAX_NR_ZONES; i++) {
6303 if (i == ZONE_MOVABLE)
6305 pr_info(" %-8s ", zone_names[i]);
6306 if (arch_zone_lowest_possible_pfn[i] ==
6307 arch_zone_highest_possible_pfn[i])
6310 pr_cont("[mem %#018Lx-%#018Lx]\n",
6311 (u64)arch_zone_lowest_possible_pfn[i]
6313 ((u64)arch_zone_highest_possible_pfn[i]
6314 << PAGE_SHIFT) - 1);
6317 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6318 pr_info("Movable zone start for each node\n");
6319 for (i = 0; i < MAX_NUMNODES; i++) {
6320 if (zone_movable_pfn[i])
6321 pr_info(" Node %d: %#018Lx\n", i,
6322 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6325 /* Print out the early node map */
6326 pr_info("Early memory node ranges\n");
6327 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6328 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6329 (u64)start_pfn << PAGE_SHIFT,
6330 ((u64)end_pfn << PAGE_SHIFT) - 1);
6332 /* Initialise every node */
6333 mminit_verify_pageflags_layout();
6334 setup_nr_node_ids();
6335 for_each_online_node(nid) {
6336 pg_data_t *pgdat = NODE_DATA(nid);
6337 free_area_init_node(nid, NULL,
6338 find_min_pfn_for_node(nid), NULL);
6340 /* Any memory on that node */
6341 if (pgdat->node_present_pages)
6342 node_set_state(nid, N_MEMORY);
6343 check_for_memory(pgdat, nid);
6347 static int __init cmdline_parse_core(char *p, unsigned long *core)
6349 unsigned long long coremem;
6353 coremem = memparse(p, &p);
6354 *core = coremem >> PAGE_SHIFT;
6356 /* Paranoid check that UL is enough for the coremem value */
6357 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6363 * kernelcore=size sets the amount of memory for use for allocations that
6364 * cannot be reclaimed or migrated.
6366 static int __init cmdline_parse_kernelcore(char *p)
6368 /* parse kernelcore=mirror */
6369 if (parse_option_str(p, "mirror")) {
6370 mirrored_kernelcore = true;
6374 return cmdline_parse_core(p, &required_kernelcore);
6378 * movablecore=size sets the amount of memory for use for allocations that
6379 * can be reclaimed or migrated.
6381 static int __init cmdline_parse_movablecore(char *p)
6383 return cmdline_parse_core(p, &required_movablecore);
6386 early_param("kernelcore", cmdline_parse_kernelcore);
6387 early_param("movablecore", cmdline_parse_movablecore);
6389 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6391 void adjust_managed_page_count(struct page *page, long count)
6393 spin_lock(&managed_page_count_lock);
6394 page_zone(page)->managed_pages += count;
6395 totalram_pages += count;
6396 #ifdef CONFIG_HIGHMEM
6397 if (PageHighMem(page))
6398 totalhigh_pages += count;
6400 spin_unlock(&managed_page_count_lock);
6402 EXPORT_SYMBOL(adjust_managed_page_count);
6404 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6407 unsigned long pages = 0;
6409 start = (void *)PAGE_ALIGN((unsigned long)start);
6410 end = (void *)((unsigned long)end & PAGE_MASK);
6411 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6412 if ((unsigned int)poison <= 0xFF)
6413 memset(pos, poison, PAGE_SIZE);
6414 free_reserved_page(virt_to_page(pos));
6418 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6419 s, pages << (PAGE_SHIFT - 10), start, end);
6423 EXPORT_SYMBOL(free_reserved_area);
6425 #ifdef CONFIG_HIGHMEM
6426 void free_highmem_page(struct page *page)
6428 __free_reserved_page(page);
6430 page_zone(page)->managed_pages++;
6436 void __init mem_init_print_info(const char *str)
6438 unsigned long physpages, codesize, datasize, rosize, bss_size;
6439 unsigned long init_code_size, init_data_size;
6441 physpages = get_num_physpages();
6442 codesize = _etext - _stext;
6443 datasize = _edata - _sdata;
6444 rosize = __end_rodata - __start_rodata;
6445 bss_size = __bss_stop - __bss_start;
6446 init_data_size = __init_end - __init_begin;
6447 init_code_size = _einittext - _sinittext;
6450 * Detect special cases and adjust section sizes accordingly:
6451 * 1) .init.* may be embedded into .data sections
6452 * 2) .init.text.* may be out of [__init_begin, __init_end],
6453 * please refer to arch/tile/kernel/vmlinux.lds.S.
6454 * 3) .rodata.* may be embedded into .text or .data sections.
6456 #define adj_init_size(start, end, size, pos, adj) \
6458 if (start <= pos && pos < end && size > adj) \
6462 adj_init_size(__init_begin, __init_end, init_data_size,
6463 _sinittext, init_code_size);
6464 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6465 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6466 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6467 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6469 #undef adj_init_size
6471 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6472 #ifdef CONFIG_HIGHMEM
6476 nr_free_pages() << (PAGE_SHIFT - 10),
6477 physpages << (PAGE_SHIFT - 10),
6478 codesize >> 10, datasize >> 10, rosize >> 10,
6479 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6480 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6481 totalcma_pages << (PAGE_SHIFT - 10),
6482 #ifdef CONFIG_HIGHMEM
6483 totalhigh_pages << (PAGE_SHIFT - 10),
6485 str ? ", " : "", str ? str : "");
6489 * set_dma_reserve - set the specified number of pages reserved in the first zone
6490 * @new_dma_reserve: The number of pages to mark reserved
6492 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6493 * In the DMA zone, a significant percentage may be consumed by kernel image
6494 * and other unfreeable allocations which can skew the watermarks badly. This
6495 * function may optionally be used to account for unfreeable pages in the
6496 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6497 * smaller per-cpu batchsize.
6499 void __init set_dma_reserve(unsigned long new_dma_reserve)
6501 dma_reserve = new_dma_reserve;
6504 void __init free_area_init(unsigned long *zones_size)
6506 free_area_init_node(0, zones_size,
6507 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6510 static int page_alloc_cpu_notify(struct notifier_block *self,
6511 unsigned long action, void *hcpu)
6513 int cpu = (unsigned long)hcpu;
6515 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6516 lru_add_drain_cpu(cpu);
6520 * Spill the event counters of the dead processor
6521 * into the current processors event counters.
6522 * This artificially elevates the count of the current
6525 vm_events_fold_cpu(cpu);
6528 * Zero the differential counters of the dead processor
6529 * so that the vm statistics are consistent.
6531 * This is only okay since the processor is dead and cannot
6532 * race with what we are doing.
6534 cpu_vm_stats_fold(cpu);
6539 void __init page_alloc_init(void)
6541 hotcpu_notifier(page_alloc_cpu_notify, 0);
6545 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6546 * or min_free_kbytes changes.
6548 static void calculate_totalreserve_pages(void)
6550 struct pglist_data *pgdat;
6551 unsigned long reserve_pages = 0;
6552 enum zone_type i, j;
6554 for_each_online_pgdat(pgdat) {
6556 pgdat->totalreserve_pages = 0;
6558 for (i = 0; i < MAX_NR_ZONES; i++) {
6559 struct zone *zone = pgdat->node_zones + i;
6562 /* Find valid and maximum lowmem_reserve in the zone */
6563 for (j = i; j < MAX_NR_ZONES; j++) {
6564 if (zone->lowmem_reserve[j] > max)
6565 max = zone->lowmem_reserve[j];
6568 /* we treat the high watermark as reserved pages. */
6569 max += high_wmark_pages(zone);
6571 if (max > zone->managed_pages)
6572 max = zone->managed_pages;
6574 pgdat->totalreserve_pages += max;
6576 reserve_pages += max;
6579 totalreserve_pages = reserve_pages;
6583 * setup_per_zone_lowmem_reserve - called whenever
6584 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6585 * has a correct pages reserved value, so an adequate number of
6586 * pages are left in the zone after a successful __alloc_pages().
6588 static void setup_per_zone_lowmem_reserve(void)
6590 struct pglist_data *pgdat;
6591 enum zone_type j, idx;
6593 for_each_online_pgdat(pgdat) {
6594 for (j = 0; j < MAX_NR_ZONES; j++) {
6595 struct zone *zone = pgdat->node_zones + j;
6596 unsigned long managed_pages = zone->managed_pages;
6598 zone->lowmem_reserve[j] = 0;
6602 struct zone *lower_zone;
6606 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6607 sysctl_lowmem_reserve_ratio[idx] = 1;
6609 lower_zone = pgdat->node_zones + idx;
6610 lower_zone->lowmem_reserve[j] = managed_pages /
6611 sysctl_lowmem_reserve_ratio[idx];
6612 managed_pages += lower_zone->managed_pages;
6617 /* update totalreserve_pages */
6618 calculate_totalreserve_pages();
6621 static void __setup_per_zone_wmarks(void)
6623 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6624 unsigned long lowmem_pages = 0;
6626 unsigned long flags;
6628 /* Calculate total number of !ZONE_HIGHMEM pages */
6629 for_each_zone(zone) {
6630 if (!is_highmem(zone))
6631 lowmem_pages += zone->managed_pages;
6634 for_each_zone(zone) {
6637 spin_lock_irqsave(&zone->lock, flags);
6638 tmp = (u64)pages_min * zone->managed_pages;
6639 do_div(tmp, lowmem_pages);
6640 if (is_highmem(zone)) {
6642 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6643 * need highmem pages, so cap pages_min to a small
6646 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6647 * deltas control asynch page reclaim, and so should
6648 * not be capped for highmem.
6650 unsigned long min_pages;
6652 min_pages = zone->managed_pages / 1024;
6653 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6654 zone->watermark[WMARK_MIN] = min_pages;
6657 * If it's a lowmem zone, reserve a number of pages
6658 * proportionate to the zone's size.
6660 zone->watermark[WMARK_MIN] = tmp;
6664 * Set the kswapd watermarks distance according to the
6665 * scale factor in proportion to available memory, but
6666 * ensure a minimum size on small systems.
6668 tmp = max_t(u64, tmp >> 2,
6669 mult_frac(zone->managed_pages,
6670 watermark_scale_factor, 10000));
6672 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6673 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6675 spin_unlock_irqrestore(&zone->lock, flags);
6678 /* update totalreserve_pages */
6679 calculate_totalreserve_pages();
6683 * setup_per_zone_wmarks - called when min_free_kbytes changes
6684 * or when memory is hot-{added|removed}
6686 * Ensures that the watermark[min,low,high] values for each zone are set
6687 * correctly with respect to min_free_kbytes.
6689 void setup_per_zone_wmarks(void)
6691 mutex_lock(&zonelists_mutex);
6692 __setup_per_zone_wmarks();
6693 mutex_unlock(&zonelists_mutex);
6697 * Initialise min_free_kbytes.
6699 * For small machines we want it small (128k min). For large machines
6700 * we want it large (64MB max). But it is not linear, because network
6701 * bandwidth does not increase linearly with machine size. We use
6703 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6704 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6720 int __meminit init_per_zone_wmark_min(void)
6722 unsigned long lowmem_kbytes;
6723 int new_min_free_kbytes;
6725 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6726 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6728 if (new_min_free_kbytes > user_min_free_kbytes) {
6729 min_free_kbytes = new_min_free_kbytes;
6730 if (min_free_kbytes < 128)
6731 min_free_kbytes = 128;
6732 if (min_free_kbytes > 65536)
6733 min_free_kbytes = 65536;
6735 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6736 new_min_free_kbytes, user_min_free_kbytes);
6738 setup_per_zone_wmarks();
6739 refresh_zone_stat_thresholds();
6740 setup_per_zone_lowmem_reserve();
6743 setup_min_unmapped_ratio();
6744 setup_min_slab_ratio();
6749 core_initcall(init_per_zone_wmark_min)
6752 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6753 * that we can call two helper functions whenever min_free_kbytes
6756 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6757 void __user *buffer, size_t *length, loff_t *ppos)
6761 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6766 user_min_free_kbytes = min_free_kbytes;
6767 setup_per_zone_wmarks();
6772 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6773 void __user *buffer, size_t *length, loff_t *ppos)
6777 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6782 setup_per_zone_wmarks();
6788 static void setup_min_unmapped_ratio(void)
6793 for_each_online_pgdat(pgdat)
6794 pgdat->min_unmapped_pages = 0;
6797 zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
6798 sysctl_min_unmapped_ratio) / 100;
6802 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6803 void __user *buffer, size_t *length, loff_t *ppos)
6807 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6811 setup_min_unmapped_ratio();
6816 static void setup_min_slab_ratio(void)
6821 for_each_online_pgdat(pgdat)
6822 pgdat->min_slab_pages = 0;
6825 zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
6826 sysctl_min_slab_ratio) / 100;
6829 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6830 void __user *buffer, size_t *length, loff_t *ppos)
6834 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6838 setup_min_slab_ratio();
6845 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6846 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6847 * whenever sysctl_lowmem_reserve_ratio changes.
6849 * The reserve ratio obviously has absolutely no relation with the
6850 * minimum watermarks. The lowmem reserve ratio can only make sense
6851 * if in function of the boot time zone sizes.
6853 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6854 void __user *buffer, size_t *length, loff_t *ppos)
6856 proc_dointvec_minmax(table, write, buffer, length, ppos);
6857 setup_per_zone_lowmem_reserve();
6862 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6863 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6864 * pagelist can have before it gets flushed back to buddy allocator.
6866 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6867 void __user *buffer, size_t *length, loff_t *ppos)
6870 int old_percpu_pagelist_fraction;
6873 mutex_lock(&pcp_batch_high_lock);
6874 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6876 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6877 if (!write || ret < 0)
6880 /* Sanity checking to avoid pcp imbalance */
6881 if (percpu_pagelist_fraction &&
6882 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6883 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6889 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6892 for_each_populated_zone(zone) {
6895 for_each_possible_cpu(cpu)
6896 pageset_set_high_and_batch(zone,
6897 per_cpu_ptr(zone->pageset, cpu));
6900 mutex_unlock(&pcp_batch_high_lock);
6905 int hashdist = HASHDIST_DEFAULT;
6907 static int __init set_hashdist(char *str)
6911 hashdist = simple_strtoul(str, &str, 0);
6914 __setup("hashdist=", set_hashdist);
6917 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
6919 * Returns the number of pages that arch has reserved but
6920 * is not known to alloc_large_system_hash().
6922 static unsigned long __init arch_reserved_kernel_pages(void)
6929 * allocate a large system hash table from bootmem
6930 * - it is assumed that the hash table must contain an exact power-of-2
6931 * quantity of entries
6932 * - limit is the number of hash buckets, not the total allocation size
6934 void *__init alloc_large_system_hash(const char *tablename,
6935 unsigned long bucketsize,
6936 unsigned long numentries,
6939 unsigned int *_hash_shift,
6940 unsigned int *_hash_mask,
6941 unsigned long low_limit,
6942 unsigned long high_limit)
6944 unsigned long long max = high_limit;
6945 unsigned long log2qty, size;
6948 /* allow the kernel cmdline to have a say */
6950 /* round applicable memory size up to nearest megabyte */
6951 numentries = nr_kernel_pages;
6952 numentries -= arch_reserved_kernel_pages();
6954 /* It isn't necessary when PAGE_SIZE >= 1MB */
6955 if (PAGE_SHIFT < 20)
6956 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6958 /* limit to 1 bucket per 2^scale bytes of low memory */
6959 if (scale > PAGE_SHIFT)
6960 numentries >>= (scale - PAGE_SHIFT);
6962 numentries <<= (PAGE_SHIFT - scale);
6964 /* Make sure we've got at least a 0-order allocation.. */
6965 if (unlikely(flags & HASH_SMALL)) {
6966 /* Makes no sense without HASH_EARLY */
6967 WARN_ON(!(flags & HASH_EARLY));
6968 if (!(numentries >> *_hash_shift)) {
6969 numentries = 1UL << *_hash_shift;
6970 BUG_ON(!numentries);
6972 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6973 numentries = PAGE_SIZE / bucketsize;
6975 numentries = roundup_pow_of_two(numentries);
6977 /* limit allocation size to 1/16 total memory by default */
6979 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6980 do_div(max, bucketsize);
6982 max = min(max, 0x80000000ULL);
6984 if (numentries < low_limit)
6985 numentries = low_limit;
6986 if (numentries > max)
6989 log2qty = ilog2(numentries);
6992 size = bucketsize << log2qty;
6993 if (flags & HASH_EARLY)
6994 table = memblock_virt_alloc_nopanic(size, 0);
6996 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6999 * If bucketsize is not a power-of-two, we may free
7000 * some pages at the end of hash table which
7001 * alloc_pages_exact() automatically does
7003 if (get_order(size) < MAX_ORDER) {
7004 table = alloc_pages_exact(size, GFP_ATOMIC);
7005 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
7008 } while (!table && size > PAGE_SIZE && --log2qty);
7011 panic("Failed to allocate %s hash table\n", tablename);
7013 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7014 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
7017 *_hash_shift = log2qty;
7019 *_hash_mask = (1 << log2qty) - 1;
7025 * This function checks whether pageblock includes unmovable pages or not.
7026 * If @count is not zero, it is okay to include less @count unmovable pages
7028 * PageLRU check without isolation or lru_lock could race so that
7029 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7030 * expect this function should be exact.
7032 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
7033 bool skip_hwpoisoned_pages)
7035 unsigned long pfn, iter, found;
7039 * For avoiding noise data, lru_add_drain_all() should be called
7040 * If ZONE_MOVABLE, the zone never contains unmovable pages
7042 if (zone_idx(zone) == ZONE_MOVABLE)
7044 mt = get_pageblock_migratetype(page);
7045 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
7048 pfn = page_to_pfn(page);
7049 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7050 unsigned long check = pfn + iter;
7052 if (!pfn_valid_within(check))
7055 page = pfn_to_page(check);
7058 * Hugepages are not in LRU lists, but they're movable.
7059 * We need not scan over tail pages bacause we don't
7060 * handle each tail page individually in migration.
7062 if (PageHuge(page)) {
7063 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7068 * We can't use page_count without pin a page
7069 * because another CPU can free compound page.
7070 * This check already skips compound tails of THP
7071 * because their page->_refcount is zero at all time.
7073 if (!page_ref_count(page)) {
7074 if (PageBuddy(page))
7075 iter += (1 << page_order(page)) - 1;
7080 * The HWPoisoned page may be not in buddy system, and
7081 * page_count() is not 0.
7083 if (skip_hwpoisoned_pages && PageHWPoison(page))
7089 * If there are RECLAIMABLE pages, we need to check
7090 * it. But now, memory offline itself doesn't call
7091 * shrink_node_slabs() and it still to be fixed.
7094 * If the page is not RAM, page_count()should be 0.
7095 * we don't need more check. This is an _used_ not-movable page.
7097 * The problematic thing here is PG_reserved pages. PG_reserved
7098 * is set to both of a memory hole page and a _used_ kernel
7107 bool is_pageblock_removable_nolock(struct page *page)
7113 * We have to be careful here because we are iterating over memory
7114 * sections which are not zone aware so we might end up outside of
7115 * the zone but still within the section.
7116 * We have to take care about the node as well. If the node is offline
7117 * its NODE_DATA will be NULL - see page_zone.
7119 if (!node_online(page_to_nid(page)))
7122 zone = page_zone(page);
7123 pfn = page_to_pfn(page);
7124 if (!zone_spans_pfn(zone, pfn))
7127 return !has_unmovable_pages(zone, page, 0, true);
7130 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7132 static unsigned long pfn_max_align_down(unsigned long pfn)
7134 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7135 pageblock_nr_pages) - 1);
7138 static unsigned long pfn_max_align_up(unsigned long pfn)
7140 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7141 pageblock_nr_pages));
7144 /* [start, end) must belong to a single zone. */
7145 static int __alloc_contig_migrate_range(struct compact_control *cc,
7146 unsigned long start, unsigned long end)
7148 /* This function is based on compact_zone() from compaction.c. */
7149 unsigned long nr_reclaimed;
7150 unsigned long pfn = start;
7151 unsigned int tries = 0;
7156 while (pfn < end || !list_empty(&cc->migratepages)) {
7157 if (fatal_signal_pending(current)) {
7162 if (list_empty(&cc->migratepages)) {
7163 cc->nr_migratepages = 0;
7164 pfn = isolate_migratepages_range(cc, pfn, end);
7170 } else if (++tries == 5) {
7171 ret = ret < 0 ? ret : -EBUSY;
7175 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7177 cc->nr_migratepages -= nr_reclaimed;
7179 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7180 NULL, 0, cc->mode, MR_CMA);
7183 putback_movable_pages(&cc->migratepages);
7190 * alloc_contig_range() -- tries to allocate given range of pages
7191 * @start: start PFN to allocate
7192 * @end: one-past-the-last PFN to allocate
7193 * @migratetype: migratetype of the underlaying pageblocks (either
7194 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7195 * in range must have the same migratetype and it must
7196 * be either of the two.
7198 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7199 * aligned, however it's the caller's responsibility to guarantee that
7200 * we are the only thread that changes migrate type of pageblocks the
7203 * The PFN range must belong to a single zone.
7205 * Returns zero on success or negative error code. On success all
7206 * pages which PFN is in [start, end) are allocated for the caller and
7207 * need to be freed with free_contig_range().
7209 int alloc_contig_range(unsigned long start, unsigned long end,
7210 unsigned migratetype)
7212 unsigned long outer_start, outer_end;
7216 struct compact_control cc = {
7217 .nr_migratepages = 0,
7219 .zone = page_zone(pfn_to_page(start)),
7220 .mode = MIGRATE_SYNC,
7221 .ignore_skip_hint = true,
7223 INIT_LIST_HEAD(&cc.migratepages);
7226 * What we do here is we mark all pageblocks in range as
7227 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7228 * have different sizes, and due to the way page allocator
7229 * work, we align the range to biggest of the two pages so
7230 * that page allocator won't try to merge buddies from
7231 * different pageblocks and change MIGRATE_ISOLATE to some
7232 * other migration type.
7234 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7235 * migrate the pages from an unaligned range (ie. pages that
7236 * we are interested in). This will put all the pages in
7237 * range back to page allocator as MIGRATE_ISOLATE.
7239 * When this is done, we take the pages in range from page
7240 * allocator removing them from the buddy system. This way
7241 * page allocator will never consider using them.
7243 * This lets us mark the pageblocks back as
7244 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7245 * aligned range but not in the unaligned, original range are
7246 * put back to page allocator so that buddy can use them.
7249 ret = start_isolate_page_range(pfn_max_align_down(start),
7250 pfn_max_align_up(end), migratetype,
7256 * In case of -EBUSY, we'd like to know which page causes problem.
7257 * So, just fall through. We will check it in test_pages_isolated().
7259 ret = __alloc_contig_migrate_range(&cc, start, end);
7260 if (ret && ret != -EBUSY)
7264 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7265 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7266 * more, all pages in [start, end) are free in page allocator.
7267 * What we are going to do is to allocate all pages from
7268 * [start, end) (that is remove them from page allocator).
7270 * The only problem is that pages at the beginning and at the
7271 * end of interesting range may be not aligned with pages that
7272 * page allocator holds, ie. they can be part of higher order
7273 * pages. Because of this, we reserve the bigger range and
7274 * once this is done free the pages we are not interested in.
7276 * We don't have to hold zone->lock here because the pages are
7277 * isolated thus they won't get removed from buddy.
7280 lru_add_drain_all();
7281 drain_all_pages(cc.zone);
7284 outer_start = start;
7285 while (!PageBuddy(pfn_to_page(outer_start))) {
7286 if (++order >= MAX_ORDER) {
7287 outer_start = start;
7290 outer_start &= ~0UL << order;
7293 if (outer_start != start) {
7294 order = page_order(pfn_to_page(outer_start));
7297 * outer_start page could be small order buddy page and
7298 * it doesn't include start page. Adjust outer_start
7299 * in this case to report failed page properly
7300 * on tracepoint in test_pages_isolated()
7302 if (outer_start + (1UL << order) <= start)
7303 outer_start = start;
7306 /* Make sure the range is really isolated. */
7307 if (test_pages_isolated(outer_start, end, false)) {
7308 pr_info("%s: [%lx, %lx) PFNs busy\n",
7309 __func__, outer_start, end);
7314 /* Grab isolated pages from freelists. */
7315 outer_end = isolate_freepages_range(&cc, outer_start, end);
7321 /* Free head and tail (if any) */
7322 if (start != outer_start)
7323 free_contig_range(outer_start, start - outer_start);
7324 if (end != outer_end)
7325 free_contig_range(end, outer_end - end);
7328 undo_isolate_page_range(pfn_max_align_down(start),
7329 pfn_max_align_up(end), migratetype);
7333 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7335 unsigned int count = 0;
7337 for (; nr_pages--; pfn++) {
7338 struct page *page = pfn_to_page(pfn);
7340 count += page_count(page) != 1;
7343 WARN(count != 0, "%d pages are still in use!\n", count);
7347 #ifdef CONFIG_MEMORY_HOTPLUG
7349 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7350 * page high values need to be recalulated.
7352 void __meminit zone_pcp_update(struct zone *zone)
7355 mutex_lock(&pcp_batch_high_lock);
7356 for_each_possible_cpu(cpu)
7357 pageset_set_high_and_batch(zone,
7358 per_cpu_ptr(zone->pageset, cpu));
7359 mutex_unlock(&pcp_batch_high_lock);
7363 void zone_pcp_reset(struct zone *zone)
7365 unsigned long flags;
7367 struct per_cpu_pageset *pset;
7369 /* avoid races with drain_pages() */
7370 local_irq_save(flags);
7371 if (zone->pageset != &boot_pageset) {
7372 for_each_online_cpu(cpu) {
7373 pset = per_cpu_ptr(zone->pageset, cpu);
7374 drain_zonestat(zone, pset);
7376 free_percpu(zone->pageset);
7377 zone->pageset = &boot_pageset;
7379 local_irq_restore(flags);
7382 #ifdef CONFIG_MEMORY_HOTREMOVE
7384 * All pages in the range must be in a single zone and isolated
7385 * before calling this.
7388 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7392 unsigned int order, i;
7394 unsigned long flags;
7395 /* find the first valid pfn */
7396 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7401 zone = page_zone(pfn_to_page(pfn));
7402 spin_lock_irqsave(&zone->lock, flags);
7404 while (pfn < end_pfn) {
7405 if (!pfn_valid(pfn)) {
7409 page = pfn_to_page(pfn);
7411 * The HWPoisoned page may be not in buddy system, and
7412 * page_count() is not 0.
7414 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7416 SetPageReserved(page);
7420 BUG_ON(page_count(page));
7421 BUG_ON(!PageBuddy(page));
7422 order = page_order(page);
7423 #ifdef CONFIG_DEBUG_VM
7424 pr_info("remove from free list %lx %d %lx\n",
7425 pfn, 1 << order, end_pfn);
7427 list_del(&page->lru);
7428 rmv_page_order(page);
7429 zone->free_area[order].nr_free--;
7430 for (i = 0; i < (1 << order); i++)
7431 SetPageReserved((page+i));
7432 pfn += (1 << order);
7434 spin_unlock_irqrestore(&zone->lock, flags);
7438 bool is_free_buddy_page(struct page *page)
7440 struct zone *zone = page_zone(page);
7441 unsigned long pfn = page_to_pfn(page);
7442 unsigned long flags;
7445 spin_lock_irqsave(&zone->lock, flags);
7446 for (order = 0; order < MAX_ORDER; order++) {
7447 struct page *page_head = page - (pfn & ((1 << order) - 1));
7449 if (PageBuddy(page_head) && page_order(page_head) >= order)
7452 spin_unlock_irqrestore(&zone->lock, flags);
7454 return order < MAX_ORDER;