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/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/prefetch.h>
58 #include <linux/mm_inline.h>
59 #include <linux/migrate.h>
60 #include <linux/page_ext.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/page_owner.h>
64 #include <linux/kthread.h>
66 #include <asm/sections.h>
67 #include <asm/tlbflush.h>
68 #include <asm/div64.h>
71 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
72 static DEFINE_MUTEX(pcp_batch_high_lock);
73 #define MIN_PERCPU_PAGELIST_FRACTION (8)
75 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
76 DEFINE_PER_CPU(int, numa_node);
77 EXPORT_PER_CPU_SYMBOL(numa_node);
80 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
82 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
83 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
84 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
85 * defined in <linux/topology.h>.
87 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
88 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
89 int _node_numa_mem_[MAX_NUMNODES];
93 * Array of node states.
95 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
96 [N_POSSIBLE] = NODE_MASK_ALL,
97 [N_ONLINE] = { { [0] = 1UL } },
99 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
100 #ifdef CONFIG_HIGHMEM
101 [N_HIGH_MEMORY] = { { [0] = 1UL } },
103 #ifdef CONFIG_MOVABLE_NODE
104 [N_MEMORY] = { { [0] = 1UL } },
106 [N_CPU] = { { [0] = 1UL } },
109 EXPORT_SYMBOL(node_states);
111 /* Protect totalram_pages and zone->managed_pages */
112 static DEFINE_SPINLOCK(managed_page_count_lock);
114 unsigned long totalram_pages __read_mostly;
115 unsigned long totalreserve_pages __read_mostly;
116 unsigned long totalcma_pages __read_mostly;
118 * When calculating the number of globally allowed dirty pages, there
119 * is a certain number of per-zone reserves that should not be
120 * considered dirtyable memory. This is the sum of those reserves
121 * over all existing zones that contribute dirtyable memory.
123 unsigned long dirty_balance_reserve __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_IOFS;
175 bool pm_suspended_storage(void)
177 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
181 #endif /* CONFIG_PM_SLEEP */
183 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
184 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 int min_free_kbytes = 1024;
233 int user_min_free_kbytes = -1;
235 static unsigned long __meminitdata nr_kernel_pages;
236 static unsigned long __meminitdata nr_all_pages;
237 static unsigned long __meminitdata dma_reserve;
239 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
240 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
241 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
242 static unsigned long __initdata required_kernelcore;
243 static unsigned long __initdata required_movablecore;
244 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
246 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
248 EXPORT_SYMBOL(movable_zone);
249 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
252 int nr_node_ids __read_mostly = MAX_NUMNODES;
253 int nr_online_nodes __read_mostly = 1;
254 EXPORT_SYMBOL(nr_node_ids);
255 EXPORT_SYMBOL(nr_online_nodes);
258 int page_group_by_mobility_disabled __read_mostly;
260 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
261 static inline void reset_deferred_meminit(pg_data_t *pgdat)
263 pgdat->first_deferred_pfn = ULONG_MAX;
266 /* Returns true if the struct page for the pfn is uninitialised */
267 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
269 if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn)
275 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
277 if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
284 * Returns false when the remaining initialisation should be deferred until
285 * later in the boot cycle when it can be parallelised.
287 static inline bool update_defer_init(pg_data_t *pgdat,
288 unsigned long pfn, unsigned long zone_end,
289 unsigned long *nr_initialised)
291 /* Always populate low zones for address-contrained allocations */
292 if (zone_end < pgdat_end_pfn(pgdat))
295 /* Initialise at least 2G of the highest zone */
297 if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) &&
298 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
299 pgdat->first_deferred_pfn = pfn;
306 static inline void reset_deferred_meminit(pg_data_t *pgdat)
310 static inline bool early_page_uninitialised(unsigned long pfn)
315 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
320 static inline bool update_defer_init(pg_data_t *pgdat,
321 unsigned long pfn, unsigned long zone_end,
322 unsigned long *nr_initialised)
329 void set_pageblock_migratetype(struct page *page, int migratetype)
331 if (unlikely(page_group_by_mobility_disabled &&
332 migratetype < MIGRATE_PCPTYPES))
333 migratetype = MIGRATE_UNMOVABLE;
335 set_pageblock_flags_group(page, (unsigned long)migratetype,
336 PB_migrate, PB_migrate_end);
339 #ifdef CONFIG_DEBUG_VM
340 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
344 unsigned long pfn = page_to_pfn(page);
345 unsigned long sp, start_pfn;
348 seq = zone_span_seqbegin(zone);
349 start_pfn = zone->zone_start_pfn;
350 sp = zone->spanned_pages;
351 if (!zone_spans_pfn(zone, pfn))
353 } while (zone_span_seqretry(zone, seq));
356 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
357 pfn, zone_to_nid(zone), zone->name,
358 start_pfn, start_pfn + sp);
363 static int page_is_consistent(struct zone *zone, struct page *page)
365 if (!pfn_valid_within(page_to_pfn(page)))
367 if (zone != page_zone(page))
373 * Temporary debugging check for pages not lying within a given zone.
375 static int bad_range(struct zone *zone, struct page *page)
377 if (page_outside_zone_boundaries(zone, page))
379 if (!page_is_consistent(zone, page))
385 static inline int bad_range(struct zone *zone, struct page *page)
391 static void bad_page(struct page *page, const char *reason,
392 unsigned long bad_flags)
394 static unsigned long resume;
395 static unsigned long nr_shown;
396 static unsigned long nr_unshown;
398 /* Don't complain about poisoned pages */
399 if (PageHWPoison(page)) {
400 page_mapcount_reset(page); /* remove PageBuddy */
405 * Allow a burst of 60 reports, then keep quiet for that minute;
406 * or allow a steady drip of one report per second.
408 if (nr_shown == 60) {
409 if (time_before(jiffies, resume)) {
415 "BUG: Bad page state: %lu messages suppressed\n",
422 resume = jiffies + 60 * HZ;
424 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
425 current->comm, page_to_pfn(page));
426 dump_page_badflags(page, reason, bad_flags);
431 /* Leave bad fields for debug, except PageBuddy could make trouble */
432 page_mapcount_reset(page); /* remove PageBuddy */
433 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
437 * Higher-order pages are called "compound pages". They are structured thusly:
439 * The first PAGE_SIZE page is called the "head page".
441 * The remaining PAGE_SIZE pages are called "tail pages".
443 * All pages have PG_compound set. All tail pages have their ->first_page
444 * pointing at the head page.
446 * The first tail page's ->lru.next holds the address of the compound page's
447 * put_page() function. Its ->lru.prev holds the order of allocation.
448 * This usage means that zero-order pages may not be compound.
451 static void free_compound_page(struct page *page)
453 __free_pages_ok(page, compound_order(page));
456 void prep_compound_page(struct page *page, unsigned long order)
459 int nr_pages = 1 << order;
461 set_compound_page_dtor(page, free_compound_page);
462 set_compound_order(page, order);
464 for (i = 1; i < nr_pages; i++) {
465 struct page *p = page + i;
466 set_page_count(p, 0);
467 p->first_page = page;
468 /* Make sure p->first_page is always valid for PageTail() */
474 #ifdef CONFIG_DEBUG_PAGEALLOC
475 unsigned int _debug_guardpage_minorder;
476 bool _debug_pagealloc_enabled __read_mostly;
477 bool _debug_guardpage_enabled __read_mostly;
479 static int __init early_debug_pagealloc(char *buf)
484 if (strcmp(buf, "on") == 0)
485 _debug_pagealloc_enabled = true;
489 early_param("debug_pagealloc", early_debug_pagealloc);
491 static bool need_debug_guardpage(void)
493 /* If we don't use debug_pagealloc, we don't need guard page */
494 if (!debug_pagealloc_enabled())
500 static void init_debug_guardpage(void)
502 if (!debug_pagealloc_enabled())
505 _debug_guardpage_enabled = true;
508 struct page_ext_operations debug_guardpage_ops = {
509 .need = need_debug_guardpage,
510 .init = init_debug_guardpage,
513 static int __init debug_guardpage_minorder_setup(char *buf)
517 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
518 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
521 _debug_guardpage_minorder = res;
522 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
525 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
527 static inline void set_page_guard(struct zone *zone, struct page *page,
528 unsigned int order, int migratetype)
530 struct page_ext *page_ext;
532 if (!debug_guardpage_enabled())
535 page_ext = lookup_page_ext(page);
536 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
538 INIT_LIST_HEAD(&page->lru);
539 set_page_private(page, order);
540 /* Guard pages are not available for any usage */
541 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
544 static inline void clear_page_guard(struct zone *zone, struct page *page,
545 unsigned int order, int migratetype)
547 struct page_ext *page_ext;
549 if (!debug_guardpage_enabled())
552 page_ext = lookup_page_ext(page);
553 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
555 set_page_private(page, 0);
556 if (!is_migrate_isolate(migratetype))
557 __mod_zone_freepage_state(zone, (1 << order), migratetype);
560 struct page_ext_operations debug_guardpage_ops = { NULL, };
561 static inline void set_page_guard(struct zone *zone, struct page *page,
562 unsigned int order, int migratetype) {}
563 static inline void clear_page_guard(struct zone *zone, struct page *page,
564 unsigned int order, int migratetype) {}
567 static inline void set_page_order(struct page *page, unsigned int order)
569 set_page_private(page, order);
570 __SetPageBuddy(page);
573 static inline void rmv_page_order(struct page *page)
575 __ClearPageBuddy(page);
576 set_page_private(page, 0);
580 * This function checks whether a page is free && is the buddy
581 * we can do coalesce a page and its buddy if
582 * (a) the buddy is not in a hole &&
583 * (b) the buddy is in the buddy system &&
584 * (c) a page and its buddy have the same order &&
585 * (d) a page and its buddy are in the same zone.
587 * For recording whether a page is in the buddy system, we set ->_mapcount
588 * PAGE_BUDDY_MAPCOUNT_VALUE.
589 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
590 * serialized by zone->lock.
592 * For recording page's order, we use page_private(page).
594 static inline int page_is_buddy(struct page *page, struct page *buddy,
597 if (!pfn_valid_within(page_to_pfn(buddy)))
600 if (page_is_guard(buddy) && page_order(buddy) == order) {
601 if (page_zone_id(page) != page_zone_id(buddy))
604 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
609 if (PageBuddy(buddy) && page_order(buddy) == order) {
611 * zone check is done late to avoid uselessly
612 * calculating zone/node ids for pages that could
615 if (page_zone_id(page) != page_zone_id(buddy))
618 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
626 * Freeing function for a buddy system allocator.
628 * The concept of a buddy system is to maintain direct-mapped table
629 * (containing bit values) for memory blocks of various "orders".
630 * The bottom level table contains the map for the smallest allocatable
631 * units of memory (here, pages), and each level above it describes
632 * pairs of units from the levels below, hence, "buddies".
633 * At a high level, all that happens here is marking the table entry
634 * at the bottom level available, and propagating the changes upward
635 * as necessary, plus some accounting needed to play nicely with other
636 * parts of the VM system.
637 * At each level, we keep a list of pages, which are heads of continuous
638 * free pages of length of (1 << order) and marked with _mapcount
639 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
641 * So when we are allocating or freeing one, we can derive the state of the
642 * other. That is, if we allocate a small block, and both were
643 * free, the remainder of the region must be split into blocks.
644 * If a block is freed, and its buddy is also free, then this
645 * triggers coalescing into a block of larger size.
650 static inline void __free_one_page(struct page *page,
652 struct zone *zone, unsigned int order,
655 unsigned long page_idx;
656 unsigned long combined_idx;
657 unsigned long uninitialized_var(buddy_idx);
659 int max_order = MAX_ORDER;
661 VM_BUG_ON(!zone_is_initialized(zone));
662 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
664 VM_BUG_ON(migratetype == -1);
665 if (is_migrate_isolate(migratetype)) {
667 * We restrict max order of merging to prevent merge
668 * between freepages on isolate pageblock and normal
669 * pageblock. Without this, pageblock isolation
670 * could cause incorrect freepage accounting.
672 max_order = min(MAX_ORDER, pageblock_order + 1);
674 __mod_zone_freepage_state(zone, 1 << order, migratetype);
677 page_idx = pfn & ((1 << max_order) - 1);
679 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
680 VM_BUG_ON_PAGE(bad_range(zone, page), page);
682 while (order < max_order - 1) {
683 buddy_idx = __find_buddy_index(page_idx, order);
684 buddy = page + (buddy_idx - page_idx);
685 if (!page_is_buddy(page, buddy, order))
688 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
689 * merge with it and move up one order.
691 if (page_is_guard(buddy)) {
692 clear_page_guard(zone, buddy, order, migratetype);
694 list_del(&buddy->lru);
695 zone->free_area[order].nr_free--;
696 rmv_page_order(buddy);
698 combined_idx = buddy_idx & page_idx;
699 page = page + (combined_idx - page_idx);
700 page_idx = combined_idx;
703 set_page_order(page, order);
706 * If this is not the largest possible page, check if the buddy
707 * of the next-highest order is free. If it is, it's possible
708 * that pages are being freed that will coalesce soon. In case,
709 * that is happening, add the free page to the tail of the list
710 * so it's less likely to be used soon and more likely to be merged
711 * as a higher order page
713 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
714 struct page *higher_page, *higher_buddy;
715 combined_idx = buddy_idx & page_idx;
716 higher_page = page + (combined_idx - page_idx);
717 buddy_idx = __find_buddy_index(combined_idx, order + 1);
718 higher_buddy = higher_page + (buddy_idx - combined_idx);
719 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
720 list_add_tail(&page->lru,
721 &zone->free_area[order].free_list[migratetype]);
726 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
728 zone->free_area[order].nr_free++;
731 static inline int free_pages_check(struct page *page)
733 const char *bad_reason = NULL;
734 unsigned long bad_flags = 0;
736 if (unlikely(page_mapcount(page)))
737 bad_reason = "nonzero mapcount";
738 if (unlikely(page->mapping != NULL))
739 bad_reason = "non-NULL mapping";
740 if (unlikely(atomic_read(&page->_count) != 0))
741 bad_reason = "nonzero _count";
742 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
743 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
744 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
747 if (unlikely(page->mem_cgroup))
748 bad_reason = "page still charged to cgroup";
750 if (unlikely(bad_reason)) {
751 bad_page(page, bad_reason, bad_flags);
754 page_cpupid_reset_last(page);
755 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
756 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
761 * Frees a number of pages from the PCP lists
762 * Assumes all pages on list are in same zone, and of same order.
763 * count is the number of pages to free.
765 * If the zone was previously in an "all pages pinned" state then look to
766 * see if this freeing clears that state.
768 * And clear the zone's pages_scanned counter, to hold off the "all pages are
769 * pinned" detection logic.
771 static void free_pcppages_bulk(struct zone *zone, int count,
772 struct per_cpu_pages *pcp)
777 unsigned long nr_scanned;
779 spin_lock(&zone->lock);
780 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
782 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
786 struct list_head *list;
789 * Remove pages from lists in a round-robin fashion. A
790 * batch_free count is maintained that is incremented when an
791 * empty list is encountered. This is so more pages are freed
792 * off fuller lists instead of spinning excessively around empty
797 if (++migratetype == MIGRATE_PCPTYPES)
799 list = &pcp->lists[migratetype];
800 } while (list_empty(list));
802 /* This is the only non-empty list. Free them all. */
803 if (batch_free == MIGRATE_PCPTYPES)
804 batch_free = to_free;
807 int mt; /* migratetype of the to-be-freed page */
809 page = list_entry(list->prev, struct page, lru);
810 /* must delete as __free_one_page list manipulates */
811 list_del(&page->lru);
813 mt = get_pcppage_migratetype(page);
814 /* MIGRATE_ISOLATE page should not go to pcplists */
815 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
816 /* Pageblock could have been isolated meanwhile */
817 if (unlikely(has_isolate_pageblock(zone)))
818 mt = get_pageblock_migratetype(page);
820 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
821 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
822 trace_mm_page_pcpu_drain(page, 0, mt);
823 } while (--to_free && --batch_free && !list_empty(list));
825 spin_unlock(&zone->lock);
828 static void free_one_page(struct zone *zone,
829 struct page *page, unsigned long pfn,
833 unsigned long nr_scanned;
834 spin_lock(&zone->lock);
835 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
837 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
839 if (unlikely(has_isolate_pageblock(zone) ||
840 is_migrate_isolate(migratetype))) {
841 migratetype = get_pfnblock_migratetype(page, pfn);
843 __free_one_page(page, pfn, zone, order, migratetype);
844 spin_unlock(&zone->lock);
847 static int free_tail_pages_check(struct page *head_page, struct page *page)
849 if (!IS_ENABLED(CONFIG_DEBUG_VM))
851 if (unlikely(!PageTail(page))) {
852 bad_page(page, "PageTail not set", 0);
855 if (unlikely(page->first_page != head_page)) {
856 bad_page(page, "first_page not consistent", 0);
862 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
863 unsigned long zone, int nid)
865 set_page_links(page, zone, nid, pfn);
866 init_page_count(page);
867 page_mapcount_reset(page);
868 page_cpupid_reset_last(page);
870 INIT_LIST_HEAD(&page->lru);
871 #ifdef WANT_PAGE_VIRTUAL
872 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
873 if (!is_highmem_idx(zone))
874 set_page_address(page, __va(pfn << PAGE_SHIFT));
878 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
881 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
884 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
885 static void init_reserved_page(unsigned long pfn)
890 if (!early_page_uninitialised(pfn))
893 nid = early_pfn_to_nid(pfn);
894 pgdat = NODE_DATA(nid);
896 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
897 struct zone *zone = &pgdat->node_zones[zid];
899 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
902 __init_single_pfn(pfn, zid, nid);
905 static inline void init_reserved_page(unsigned long pfn)
908 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
911 * Initialised pages do not have PageReserved set. This function is
912 * called for each range allocated by the bootmem allocator and
913 * marks the pages PageReserved. The remaining valid pages are later
914 * sent to the buddy page allocator.
916 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
918 unsigned long start_pfn = PFN_DOWN(start);
919 unsigned long end_pfn = PFN_UP(end);
921 for (; start_pfn < end_pfn; start_pfn++) {
922 if (pfn_valid(start_pfn)) {
923 struct page *page = pfn_to_page(start_pfn);
925 init_reserved_page(start_pfn);
926 SetPageReserved(page);
931 static bool free_pages_prepare(struct page *page, unsigned int order)
933 bool compound = PageCompound(page);
936 VM_BUG_ON_PAGE(PageTail(page), page);
937 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
939 trace_mm_page_free(page, order);
940 kmemcheck_free_shadow(page, order);
941 kasan_free_pages(page, order);
944 page->mapping = NULL;
945 bad += free_pages_check(page);
946 for (i = 1; i < (1 << order); i++) {
948 bad += free_tail_pages_check(page, page + i);
949 bad += free_pages_check(page + i);
954 reset_page_owner(page, order);
956 if (!PageHighMem(page)) {
957 debug_check_no_locks_freed(page_address(page),
959 debug_check_no_obj_freed(page_address(page),
962 arch_free_page(page, order);
963 kernel_map_pages(page, 1 << order, 0);
968 static void __free_pages_ok(struct page *page, unsigned int order)
972 unsigned long pfn = page_to_pfn(page);
974 if (!free_pages_prepare(page, order))
977 migratetype = get_pfnblock_migratetype(page, pfn);
978 local_irq_save(flags);
979 __count_vm_events(PGFREE, 1 << order);
980 free_one_page(page_zone(page), page, pfn, order, migratetype);
981 local_irq_restore(flags);
984 static void __init __free_pages_boot_core(struct page *page,
985 unsigned long pfn, unsigned int order)
987 unsigned int nr_pages = 1 << order;
988 struct page *p = page;
992 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
994 __ClearPageReserved(p);
995 set_page_count(p, 0);
997 __ClearPageReserved(p);
998 set_page_count(p, 0);
1000 page_zone(page)->managed_pages += nr_pages;
1001 set_page_refcounted(page);
1002 __free_pages(page, order);
1005 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1006 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1008 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1010 int __meminit early_pfn_to_nid(unsigned long pfn)
1012 static DEFINE_SPINLOCK(early_pfn_lock);
1015 spin_lock(&early_pfn_lock);
1016 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1019 spin_unlock(&early_pfn_lock);
1025 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1026 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1027 struct mminit_pfnnid_cache *state)
1031 nid = __early_pfn_to_nid(pfn, state);
1032 if (nid >= 0 && nid != node)
1037 /* Only safe to use early in boot when initialisation is single-threaded */
1038 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1040 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1045 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1049 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1050 struct mminit_pfnnid_cache *state)
1057 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1060 if (early_page_uninitialised(pfn))
1062 return __free_pages_boot_core(page, pfn, order);
1065 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1066 static void __init deferred_free_range(struct page *page,
1067 unsigned long pfn, int nr_pages)
1074 /* Free a large naturally-aligned chunk if possible */
1075 if (nr_pages == MAX_ORDER_NR_PAGES &&
1076 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1077 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1078 __free_pages_boot_core(page, pfn, MAX_ORDER-1);
1082 for (i = 0; i < nr_pages; i++, page++, pfn++)
1083 __free_pages_boot_core(page, pfn, 0);
1086 /* Completion tracking for deferred_init_memmap() threads */
1087 static atomic_t pgdat_init_n_undone __initdata;
1088 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1090 static inline void __init pgdat_init_report_one_done(void)
1092 if (atomic_dec_and_test(&pgdat_init_n_undone))
1093 complete(&pgdat_init_all_done_comp);
1096 /* Initialise remaining memory on a node */
1097 static int __init deferred_init_memmap(void *data)
1099 pg_data_t *pgdat = data;
1100 int nid = pgdat->node_id;
1101 struct mminit_pfnnid_cache nid_init_state = { };
1102 unsigned long start = jiffies;
1103 unsigned long nr_pages = 0;
1104 unsigned long walk_start, walk_end;
1107 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1108 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1110 if (first_init_pfn == ULONG_MAX) {
1111 pgdat_init_report_one_done();
1115 /* Bind memory initialisation thread to a local node if possible */
1116 if (!cpumask_empty(cpumask))
1117 set_cpus_allowed_ptr(current, cpumask);
1119 /* Sanity check boundaries */
1120 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1121 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1122 pgdat->first_deferred_pfn = ULONG_MAX;
1124 /* Only the highest zone is deferred so find it */
1125 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1126 zone = pgdat->node_zones + zid;
1127 if (first_init_pfn < zone_end_pfn(zone))
1131 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1132 unsigned long pfn, end_pfn;
1133 struct page *page = NULL;
1134 struct page *free_base_page = NULL;
1135 unsigned long free_base_pfn = 0;
1138 end_pfn = min(walk_end, zone_end_pfn(zone));
1139 pfn = first_init_pfn;
1140 if (pfn < walk_start)
1142 if (pfn < zone->zone_start_pfn)
1143 pfn = zone->zone_start_pfn;
1145 for (; pfn < end_pfn; pfn++) {
1146 if (!pfn_valid_within(pfn))
1150 * Ensure pfn_valid is checked every
1151 * MAX_ORDER_NR_PAGES for memory holes
1153 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1154 if (!pfn_valid(pfn)) {
1160 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1165 /* Minimise pfn page lookups and scheduler checks */
1166 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1169 nr_pages += nr_to_free;
1170 deferred_free_range(free_base_page,
1171 free_base_pfn, nr_to_free);
1172 free_base_page = NULL;
1173 free_base_pfn = nr_to_free = 0;
1175 page = pfn_to_page(pfn);
1180 VM_BUG_ON(page_zone(page) != zone);
1184 __init_single_page(page, pfn, zid, nid);
1185 if (!free_base_page) {
1186 free_base_page = page;
1187 free_base_pfn = pfn;
1192 /* Where possible, batch up pages for a single free */
1195 /* Free the current block of pages to allocator */
1196 nr_pages += nr_to_free;
1197 deferred_free_range(free_base_page, free_base_pfn,
1199 free_base_page = NULL;
1200 free_base_pfn = nr_to_free = 0;
1203 first_init_pfn = max(end_pfn, first_init_pfn);
1206 /* Sanity check that the next zone really is unpopulated */
1207 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1209 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1210 jiffies_to_msecs(jiffies - start));
1212 pgdat_init_report_one_done();
1216 void __init page_alloc_init_late(void)
1220 /* There will be num_node_state(N_MEMORY) threads */
1221 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1222 for_each_node_state(nid, N_MEMORY) {
1223 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1226 /* Block until all are initialised */
1227 wait_for_completion(&pgdat_init_all_done_comp);
1229 /* Reinit limits that are based on free pages after the kernel is up */
1230 files_maxfiles_init();
1232 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1235 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1236 void __init init_cma_reserved_pageblock(struct page *page)
1238 unsigned i = pageblock_nr_pages;
1239 struct page *p = page;
1242 __ClearPageReserved(p);
1243 set_page_count(p, 0);
1246 set_pageblock_migratetype(page, MIGRATE_CMA);
1248 if (pageblock_order >= MAX_ORDER) {
1249 i = pageblock_nr_pages;
1252 set_page_refcounted(p);
1253 __free_pages(p, MAX_ORDER - 1);
1254 p += MAX_ORDER_NR_PAGES;
1255 } while (i -= MAX_ORDER_NR_PAGES);
1257 set_page_refcounted(page);
1258 __free_pages(page, pageblock_order);
1261 adjust_managed_page_count(page, pageblock_nr_pages);
1266 * The order of subdivision here is critical for the IO subsystem.
1267 * Please do not alter this order without good reasons and regression
1268 * testing. Specifically, as large blocks of memory are subdivided,
1269 * the order in which smaller blocks are delivered depends on the order
1270 * they're subdivided in this function. This is the primary factor
1271 * influencing the order in which pages are delivered to the IO
1272 * subsystem according to empirical testing, and this is also justified
1273 * by considering the behavior of a buddy system containing a single
1274 * large block of memory acted on by a series of small allocations.
1275 * This behavior is a critical factor in sglist merging's success.
1279 static inline void expand(struct zone *zone, struct page *page,
1280 int low, int high, struct free_area *area,
1283 unsigned long size = 1 << high;
1285 while (high > low) {
1289 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1291 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1292 debug_guardpage_enabled() &&
1293 high < debug_guardpage_minorder()) {
1295 * Mark as guard pages (or page), that will allow to
1296 * merge back to allocator when buddy will be freed.
1297 * Corresponding page table entries will not be touched,
1298 * pages will stay not present in virtual address space
1300 set_page_guard(zone, &page[size], high, migratetype);
1303 list_add(&page[size].lru, &area->free_list[migratetype]);
1305 set_page_order(&page[size], high);
1310 * This page is about to be returned from the page allocator
1312 static inline int check_new_page(struct page *page)
1314 const char *bad_reason = NULL;
1315 unsigned long bad_flags = 0;
1317 if (unlikely(page_mapcount(page)))
1318 bad_reason = "nonzero mapcount";
1319 if (unlikely(page->mapping != NULL))
1320 bad_reason = "non-NULL mapping";
1321 if (unlikely(atomic_read(&page->_count) != 0))
1322 bad_reason = "nonzero _count";
1323 if (unlikely(page->flags & __PG_HWPOISON)) {
1324 bad_reason = "HWPoisoned (hardware-corrupted)";
1325 bad_flags = __PG_HWPOISON;
1327 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1328 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1329 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1332 if (unlikely(page->mem_cgroup))
1333 bad_reason = "page still charged to cgroup";
1335 if (unlikely(bad_reason)) {
1336 bad_page(page, bad_reason, bad_flags);
1342 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1347 for (i = 0; i < (1 << order); i++) {
1348 struct page *p = page + i;
1349 if (unlikely(check_new_page(p)))
1353 set_page_private(page, 0);
1354 set_page_refcounted(page);
1356 arch_alloc_page(page, order);
1357 kernel_map_pages(page, 1 << order, 1);
1358 kasan_alloc_pages(page, order);
1360 if (gfp_flags & __GFP_ZERO)
1361 for (i = 0; i < (1 << order); i++)
1362 clear_highpage(page + i);
1364 if (order && (gfp_flags & __GFP_COMP))
1365 prep_compound_page(page, order);
1367 set_page_owner(page, order, gfp_flags);
1370 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1371 * allocate the page. The expectation is that the caller is taking
1372 * steps that will free more memory. The caller should avoid the page
1373 * being used for !PFMEMALLOC purposes.
1375 if (alloc_flags & ALLOC_NO_WATERMARKS)
1376 set_page_pfmemalloc(page);
1378 clear_page_pfmemalloc(page);
1384 * Go through the free lists for the given migratetype and remove
1385 * the smallest available page from the freelists
1388 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1391 unsigned int current_order;
1392 struct free_area *area;
1395 /* Find a page of the appropriate size in the preferred list */
1396 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1397 area = &(zone->free_area[current_order]);
1398 if (list_empty(&area->free_list[migratetype]))
1401 page = list_entry(area->free_list[migratetype].next,
1403 list_del(&page->lru);
1404 rmv_page_order(page);
1406 expand(zone, page, order, current_order, area, migratetype);
1407 set_pcppage_migratetype(page, migratetype);
1416 * This array describes the order lists are fallen back to when
1417 * the free lists for the desirable migrate type are depleted
1419 static int fallbacks[MIGRATE_TYPES][4] = {
1420 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
1421 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
1422 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
1424 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
1426 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
1427 #ifdef CONFIG_MEMORY_ISOLATION
1428 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
1433 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1436 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1439 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1440 unsigned int order) { return NULL; }
1444 * Move the free pages in a range to the free lists of the requested type.
1445 * Note that start_page and end_pages are not aligned on a pageblock
1446 * boundary. If alignment is required, use move_freepages_block()
1448 int move_freepages(struct zone *zone,
1449 struct page *start_page, struct page *end_page,
1453 unsigned long order;
1454 int pages_moved = 0;
1456 #ifndef CONFIG_HOLES_IN_ZONE
1458 * page_zone is not safe to call in this context when
1459 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1460 * anyway as we check zone boundaries in move_freepages_block().
1461 * Remove at a later date when no bug reports exist related to
1462 * grouping pages by mobility
1464 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1467 for (page = start_page; page <= end_page;) {
1468 /* Make sure we are not inadvertently changing nodes */
1469 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1471 if (!pfn_valid_within(page_to_pfn(page))) {
1476 if (!PageBuddy(page)) {
1481 order = page_order(page);
1482 list_move(&page->lru,
1483 &zone->free_area[order].free_list[migratetype]);
1485 pages_moved += 1 << order;
1491 int move_freepages_block(struct zone *zone, struct page *page,
1494 unsigned long start_pfn, end_pfn;
1495 struct page *start_page, *end_page;
1497 start_pfn = page_to_pfn(page);
1498 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1499 start_page = pfn_to_page(start_pfn);
1500 end_page = start_page + pageblock_nr_pages - 1;
1501 end_pfn = start_pfn + pageblock_nr_pages - 1;
1503 /* Do not cross zone boundaries */
1504 if (!zone_spans_pfn(zone, start_pfn))
1506 if (!zone_spans_pfn(zone, end_pfn))
1509 return move_freepages(zone, start_page, end_page, migratetype);
1512 static void change_pageblock_range(struct page *pageblock_page,
1513 int start_order, int migratetype)
1515 int nr_pageblocks = 1 << (start_order - pageblock_order);
1517 while (nr_pageblocks--) {
1518 set_pageblock_migratetype(pageblock_page, migratetype);
1519 pageblock_page += pageblock_nr_pages;
1524 * When we are falling back to another migratetype during allocation, try to
1525 * steal extra free pages from the same pageblocks to satisfy further
1526 * allocations, instead of polluting multiple pageblocks.
1528 * If we are stealing a relatively large buddy page, it is likely there will
1529 * be more free pages in the pageblock, so try to steal them all. For
1530 * reclaimable and unmovable allocations, we steal regardless of page size,
1531 * as fragmentation caused by those allocations polluting movable pageblocks
1532 * is worse than movable allocations stealing from unmovable and reclaimable
1535 static bool can_steal_fallback(unsigned int order, int start_mt)
1538 * Leaving this order check is intended, although there is
1539 * relaxed order check in next check. The reason is that
1540 * we can actually steal whole pageblock if this condition met,
1541 * but, below check doesn't guarantee it and that is just heuristic
1542 * so could be changed anytime.
1544 if (order >= pageblock_order)
1547 if (order >= pageblock_order / 2 ||
1548 start_mt == MIGRATE_RECLAIMABLE ||
1549 start_mt == MIGRATE_UNMOVABLE ||
1550 page_group_by_mobility_disabled)
1557 * This function implements actual steal behaviour. If order is large enough,
1558 * we can steal whole pageblock. If not, we first move freepages in this
1559 * pageblock and check whether half of pages are moved or not. If half of
1560 * pages are moved, we can change migratetype of pageblock and permanently
1561 * use it's pages as requested migratetype in the future.
1563 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1566 int current_order = page_order(page);
1569 /* Take ownership for orders >= pageblock_order */
1570 if (current_order >= pageblock_order) {
1571 change_pageblock_range(page, current_order, start_type);
1575 pages = move_freepages_block(zone, page, start_type);
1577 /* Claim the whole block if over half of it is free */
1578 if (pages >= (1 << (pageblock_order-1)) ||
1579 page_group_by_mobility_disabled)
1580 set_pageblock_migratetype(page, start_type);
1584 * Check whether there is a suitable fallback freepage with requested order.
1585 * If only_stealable is true, this function returns fallback_mt only if
1586 * we can steal other freepages all together. This would help to reduce
1587 * fragmentation due to mixed migratetype pages in one pageblock.
1589 int find_suitable_fallback(struct free_area *area, unsigned int order,
1590 int migratetype, bool only_stealable, bool *can_steal)
1595 if (area->nr_free == 0)
1600 fallback_mt = fallbacks[migratetype][i];
1601 if (fallback_mt == MIGRATE_RESERVE)
1604 if (list_empty(&area->free_list[fallback_mt]))
1607 if (can_steal_fallback(order, migratetype))
1610 if (!only_stealable)
1620 /* Remove an element from the buddy allocator from the fallback list */
1621 static inline struct page *
1622 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1624 struct free_area *area;
1625 unsigned int current_order;
1630 /* Find the largest possible block of pages in the other list */
1631 for (current_order = MAX_ORDER-1;
1632 current_order >= order && current_order <= MAX_ORDER-1;
1634 area = &(zone->free_area[current_order]);
1635 fallback_mt = find_suitable_fallback(area, current_order,
1636 start_migratetype, false, &can_steal);
1637 if (fallback_mt == -1)
1640 page = list_entry(area->free_list[fallback_mt].next,
1643 steal_suitable_fallback(zone, page, start_migratetype);
1645 /* Remove the page from the freelists */
1647 list_del(&page->lru);
1648 rmv_page_order(page);
1650 expand(zone, page, order, current_order, area,
1653 * The pcppage_migratetype may differ from pageblock's
1654 * migratetype depending on the decisions in
1655 * find_suitable_fallback(). This is OK as long as it does not
1656 * differ for MIGRATE_CMA pageblocks. Those can be used as
1657 * fallback only via special __rmqueue_cma_fallback() function
1659 set_pcppage_migratetype(page, start_migratetype);
1661 trace_mm_page_alloc_extfrag(page, order, current_order,
1662 start_migratetype, fallback_mt);
1671 * Do the hard work of removing an element from the buddy allocator.
1672 * Call me with the zone->lock already held.
1674 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1680 page = __rmqueue_smallest(zone, order, migratetype);
1682 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1683 if (migratetype == MIGRATE_MOVABLE)
1684 page = __rmqueue_cma_fallback(zone, order);
1687 page = __rmqueue_fallback(zone, order, migratetype);
1690 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1691 * is used because __rmqueue_smallest is an inline function
1692 * and we want just one call site
1695 migratetype = MIGRATE_RESERVE;
1700 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1705 * Obtain a specified number of elements from the buddy allocator, all under
1706 * a single hold of the lock, for efficiency. Add them to the supplied list.
1707 * Returns the number of new pages which were placed at *list.
1709 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1710 unsigned long count, struct list_head *list,
1711 int migratetype, bool cold)
1715 spin_lock(&zone->lock);
1716 for (i = 0; i < count; ++i) {
1717 struct page *page = __rmqueue(zone, order, migratetype);
1718 if (unlikely(page == NULL))
1722 * Split buddy pages returned by expand() are received here
1723 * in physical page order. The page is added to the callers and
1724 * list and the list head then moves forward. From the callers
1725 * perspective, the linked list is ordered by page number in
1726 * some conditions. This is useful for IO devices that can
1727 * merge IO requests if the physical pages are ordered
1731 list_add(&page->lru, list);
1733 list_add_tail(&page->lru, list);
1735 if (is_migrate_cma(get_pcppage_migratetype(page)))
1736 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1739 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1740 spin_unlock(&zone->lock);
1746 * Called from the vmstat counter updater to drain pagesets of this
1747 * currently executing processor on remote nodes after they have
1750 * Note that this function must be called with the thread pinned to
1751 * a single processor.
1753 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1755 unsigned long flags;
1756 int to_drain, batch;
1758 local_irq_save(flags);
1759 batch = READ_ONCE(pcp->batch);
1760 to_drain = min(pcp->count, batch);
1762 free_pcppages_bulk(zone, to_drain, pcp);
1763 pcp->count -= to_drain;
1765 local_irq_restore(flags);
1770 * Drain pcplists of the indicated processor and zone.
1772 * The processor must either be the current processor and the
1773 * thread pinned to the current processor or a processor that
1776 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
1778 unsigned long flags;
1779 struct per_cpu_pageset *pset;
1780 struct per_cpu_pages *pcp;
1782 local_irq_save(flags);
1783 pset = per_cpu_ptr(zone->pageset, cpu);
1787 free_pcppages_bulk(zone, pcp->count, pcp);
1790 local_irq_restore(flags);
1794 * Drain pcplists of all zones on the indicated processor.
1796 * The processor must either be the current processor and the
1797 * thread pinned to the current processor or a processor that
1800 static void drain_pages(unsigned int cpu)
1804 for_each_populated_zone(zone) {
1805 drain_pages_zone(cpu, zone);
1810 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1812 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1813 * the single zone's pages.
1815 void drain_local_pages(struct zone *zone)
1817 int cpu = smp_processor_id();
1820 drain_pages_zone(cpu, zone);
1826 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1828 * When zone parameter is non-NULL, spill just the single zone's pages.
1830 * Note that this code is protected against sending an IPI to an offline
1831 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1832 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1833 * nothing keeps CPUs from showing up after we populated the cpumask and
1834 * before the call to on_each_cpu_mask().
1836 void drain_all_pages(struct zone *zone)
1841 * Allocate in the BSS so we wont require allocation in
1842 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1844 static cpumask_t cpus_with_pcps;
1847 * We don't care about racing with CPU hotplug event
1848 * as offline notification will cause the notified
1849 * cpu to drain that CPU pcps and on_each_cpu_mask
1850 * disables preemption as part of its processing
1852 for_each_online_cpu(cpu) {
1853 struct per_cpu_pageset *pcp;
1855 bool has_pcps = false;
1858 pcp = per_cpu_ptr(zone->pageset, cpu);
1862 for_each_populated_zone(z) {
1863 pcp = per_cpu_ptr(z->pageset, cpu);
1864 if (pcp->pcp.count) {
1872 cpumask_set_cpu(cpu, &cpus_with_pcps);
1874 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1876 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
1880 #ifdef CONFIG_HIBERNATION
1882 void mark_free_pages(struct zone *zone)
1884 unsigned long pfn, max_zone_pfn;
1885 unsigned long flags;
1886 unsigned int order, t;
1887 struct list_head *curr;
1889 if (zone_is_empty(zone))
1892 spin_lock_irqsave(&zone->lock, flags);
1894 max_zone_pfn = zone_end_pfn(zone);
1895 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1896 if (pfn_valid(pfn)) {
1897 struct page *page = pfn_to_page(pfn);
1899 if (!swsusp_page_is_forbidden(page))
1900 swsusp_unset_page_free(page);
1903 for_each_migratetype_order(order, t) {
1904 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1907 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1908 for (i = 0; i < (1UL << order); i++)
1909 swsusp_set_page_free(pfn_to_page(pfn + i));
1912 spin_unlock_irqrestore(&zone->lock, flags);
1914 #endif /* CONFIG_PM */
1917 * Free a 0-order page
1918 * cold == true ? free a cold page : free a hot page
1920 void free_hot_cold_page(struct page *page, bool cold)
1922 struct zone *zone = page_zone(page);
1923 struct per_cpu_pages *pcp;
1924 unsigned long flags;
1925 unsigned long pfn = page_to_pfn(page);
1928 if (!free_pages_prepare(page, 0))
1931 migratetype = get_pfnblock_migratetype(page, pfn);
1932 set_pcppage_migratetype(page, migratetype);
1933 local_irq_save(flags);
1934 __count_vm_event(PGFREE);
1937 * We only track unmovable, reclaimable and movable on pcp lists.
1938 * Free ISOLATE pages back to the allocator because they are being
1939 * offlined but treat RESERVE as movable pages so we can get those
1940 * areas back if necessary. Otherwise, we may have to free
1941 * excessively into the page allocator
1943 if (migratetype >= MIGRATE_PCPTYPES) {
1944 if (unlikely(is_migrate_isolate(migratetype))) {
1945 free_one_page(zone, page, pfn, 0, migratetype);
1948 migratetype = MIGRATE_MOVABLE;
1951 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1953 list_add(&page->lru, &pcp->lists[migratetype]);
1955 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1957 if (pcp->count >= pcp->high) {
1958 unsigned long batch = READ_ONCE(pcp->batch);
1959 free_pcppages_bulk(zone, batch, pcp);
1960 pcp->count -= batch;
1964 local_irq_restore(flags);
1968 * Free a list of 0-order pages
1970 void free_hot_cold_page_list(struct list_head *list, bool cold)
1972 struct page *page, *next;
1974 list_for_each_entry_safe(page, next, list, lru) {
1975 trace_mm_page_free_batched(page, cold);
1976 free_hot_cold_page(page, cold);
1981 * split_page takes a non-compound higher-order page, and splits it into
1982 * n (1<<order) sub-pages: page[0..n]
1983 * Each sub-page must be freed individually.
1985 * Note: this is probably too low level an operation for use in drivers.
1986 * Please consult with lkml before using this in your driver.
1988 void split_page(struct page *page, unsigned int order)
1993 VM_BUG_ON_PAGE(PageCompound(page), page);
1994 VM_BUG_ON_PAGE(!page_count(page), page);
1996 #ifdef CONFIG_KMEMCHECK
1998 * Split shadow pages too, because free(page[0]) would
1999 * otherwise free the whole shadow.
2001 if (kmemcheck_page_is_tracked(page))
2002 split_page(virt_to_page(page[0].shadow), order);
2005 gfp_mask = get_page_owner_gfp(page);
2006 set_page_owner(page, 0, gfp_mask);
2007 for (i = 1; i < (1 << order); i++) {
2008 set_page_refcounted(page + i);
2009 set_page_owner(page + i, 0, gfp_mask);
2012 EXPORT_SYMBOL_GPL(split_page);
2014 int __isolate_free_page(struct page *page, unsigned int order)
2016 unsigned long watermark;
2020 BUG_ON(!PageBuddy(page));
2022 zone = page_zone(page);
2023 mt = get_pageblock_migratetype(page);
2025 if (!is_migrate_isolate(mt)) {
2026 /* Obey watermarks as if the page was being allocated */
2027 watermark = low_wmark_pages(zone) + (1 << order);
2028 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2031 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2034 /* Remove page from free list */
2035 list_del(&page->lru);
2036 zone->free_area[order].nr_free--;
2037 rmv_page_order(page);
2039 set_page_owner(page, order, __GFP_MOVABLE);
2041 /* Set the pageblock if the isolated page is at least a pageblock */
2042 if (order >= pageblock_order - 1) {
2043 struct page *endpage = page + (1 << order) - 1;
2044 for (; page < endpage; page += pageblock_nr_pages) {
2045 int mt = get_pageblock_migratetype(page);
2046 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2047 set_pageblock_migratetype(page,
2053 return 1UL << order;
2057 * Similar to split_page except the page is already free. As this is only
2058 * being used for migration, the migratetype of the block also changes.
2059 * As this is called with interrupts disabled, the caller is responsible
2060 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2063 * Note: this is probably too low level an operation for use in drivers.
2064 * Please consult with lkml before using this in your driver.
2066 int split_free_page(struct page *page)
2071 order = page_order(page);
2073 nr_pages = __isolate_free_page(page, order);
2077 /* Split into individual pages */
2078 set_page_refcounted(page);
2079 split_page(page, order);
2084 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2087 struct page *buffered_rmqueue(struct zone *preferred_zone,
2088 struct zone *zone, unsigned int order,
2089 gfp_t gfp_flags, int migratetype)
2091 unsigned long flags;
2093 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2095 if (likely(order == 0)) {
2096 struct per_cpu_pages *pcp;
2097 struct list_head *list;
2099 local_irq_save(flags);
2100 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2101 list = &pcp->lists[migratetype];
2102 if (list_empty(list)) {
2103 pcp->count += rmqueue_bulk(zone, 0,
2106 if (unlikely(list_empty(list)))
2111 page = list_entry(list->prev, struct page, lru);
2113 page = list_entry(list->next, struct page, lru);
2115 list_del(&page->lru);
2118 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
2120 * __GFP_NOFAIL is not to be used in new code.
2122 * All __GFP_NOFAIL callers should be fixed so that they
2123 * properly detect and handle allocation failures.
2125 * We most definitely don't want callers attempting to
2126 * allocate greater than order-1 page units with
2129 WARN_ON_ONCE(order > 1);
2131 spin_lock_irqsave(&zone->lock, flags);
2132 page = __rmqueue(zone, order, migratetype);
2133 spin_unlock(&zone->lock);
2136 __mod_zone_freepage_state(zone, -(1 << order),
2137 get_pcppage_migratetype(page));
2140 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2141 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2142 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2143 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2145 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2146 zone_statistics(preferred_zone, zone, gfp_flags);
2147 local_irq_restore(flags);
2149 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2153 local_irq_restore(flags);
2157 #ifdef CONFIG_FAIL_PAGE_ALLOC
2160 struct fault_attr attr;
2162 bool ignore_gfp_highmem;
2163 bool ignore_gfp_wait;
2165 } fail_page_alloc = {
2166 .attr = FAULT_ATTR_INITIALIZER,
2167 .ignore_gfp_wait = true,
2168 .ignore_gfp_highmem = true,
2172 static int __init setup_fail_page_alloc(char *str)
2174 return setup_fault_attr(&fail_page_alloc.attr, str);
2176 __setup("fail_page_alloc=", setup_fail_page_alloc);
2178 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2180 if (order < fail_page_alloc.min_order)
2182 if (gfp_mask & __GFP_NOFAIL)
2184 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2186 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
2189 return should_fail(&fail_page_alloc.attr, 1 << order);
2192 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2194 static int __init fail_page_alloc_debugfs(void)
2196 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2199 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2200 &fail_page_alloc.attr);
2202 return PTR_ERR(dir);
2204 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2205 &fail_page_alloc.ignore_gfp_wait))
2207 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2208 &fail_page_alloc.ignore_gfp_highmem))
2210 if (!debugfs_create_u32("min-order", mode, dir,
2211 &fail_page_alloc.min_order))
2216 debugfs_remove_recursive(dir);
2221 late_initcall(fail_page_alloc_debugfs);
2223 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2225 #else /* CONFIG_FAIL_PAGE_ALLOC */
2227 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2232 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2235 * Return true if free pages are above 'mark'. This takes into account the order
2236 * of the allocation.
2238 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2239 unsigned long mark, int classzone_idx, int alloc_flags,
2242 /* free_pages may go negative - that's OK */
2247 free_pages -= (1 << order) - 1;
2248 if (alloc_flags & ALLOC_HIGH)
2250 if (alloc_flags & ALLOC_HARDER)
2254 /* If allocation can't use CMA areas don't use free CMA pages */
2255 if (!(alloc_flags & ALLOC_CMA))
2256 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
2259 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
2261 for (o = 0; o < order; o++) {
2262 /* At the next order, this order's pages become unavailable */
2263 free_pages -= z->free_area[o].nr_free << o;
2265 /* Require fewer higher order pages to be free */
2268 if (free_pages <= min)
2274 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2275 int classzone_idx, int alloc_flags)
2277 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2278 zone_page_state(z, NR_FREE_PAGES));
2281 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2282 unsigned long mark, int classzone_idx)
2284 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2286 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2287 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2289 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2295 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
2296 * skip over zones that are not allowed by the cpuset, or that have
2297 * been recently (in last second) found to be nearly full. See further
2298 * comments in mmzone.h. Reduces cache footprint of zonelist scans
2299 * that have to skip over a lot of full or unallowed zones.
2301 * If the zonelist cache is present in the passed zonelist, then
2302 * returns a pointer to the allowed node mask (either the current
2303 * tasks mems_allowed, or node_states[N_MEMORY].)
2305 * If the zonelist cache is not available for this zonelist, does
2306 * nothing and returns NULL.
2308 * If the fullzones BITMAP in the zonelist cache is stale (more than
2309 * a second since last zap'd) then we zap it out (clear its bits.)
2311 * We hold off even calling zlc_setup, until after we've checked the
2312 * first zone in the zonelist, on the theory that most allocations will
2313 * be satisfied from that first zone, so best to examine that zone as
2314 * quickly as we can.
2316 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
2318 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2319 nodemask_t *allowednodes; /* zonelist_cache approximation */
2321 zlc = zonelist->zlcache_ptr;
2325 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
2326 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2327 zlc->last_full_zap = jiffies;
2330 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
2331 &cpuset_current_mems_allowed :
2332 &node_states[N_MEMORY];
2333 return allowednodes;
2337 * Given 'z' scanning a zonelist, run a couple of quick checks to see
2338 * if it is worth looking at further for free memory:
2339 * 1) Check that the zone isn't thought to be full (doesn't have its
2340 * bit set in the zonelist_cache fullzones BITMAP).
2341 * 2) Check that the zones node (obtained from the zonelist_cache
2342 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
2343 * Return true (non-zero) if zone is worth looking at further, or
2344 * else return false (zero) if it is not.
2346 * This check -ignores- the distinction between various watermarks,
2347 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
2348 * found to be full for any variation of these watermarks, it will
2349 * be considered full for up to one second by all requests, unless
2350 * we are so low on memory on all allowed nodes that we are forced
2351 * into the second scan of the zonelist.
2353 * In the second scan we ignore this zonelist cache and exactly
2354 * apply the watermarks to all zones, even it is slower to do so.
2355 * We are low on memory in the second scan, and should leave no stone
2356 * unturned looking for a free page.
2358 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
2359 nodemask_t *allowednodes)
2361 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2362 int i; /* index of *z in zonelist zones */
2363 int n; /* node that zone *z is on */
2365 zlc = zonelist->zlcache_ptr;
2369 i = z - zonelist->_zonerefs;
2372 /* This zone is worth trying if it is allowed but not full */
2373 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
2377 * Given 'z' scanning a zonelist, set the corresponding bit in
2378 * zlc->fullzones, so that subsequent attempts to allocate a page
2379 * from that zone don't waste time re-examining it.
2381 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
2383 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2384 int i; /* index of *z in zonelist zones */
2386 zlc = zonelist->zlcache_ptr;
2390 i = z - zonelist->_zonerefs;
2392 set_bit(i, zlc->fullzones);
2396 * clear all zones full, called after direct reclaim makes progress so that
2397 * a zone that was recently full is not skipped over for up to a second
2399 static void zlc_clear_zones_full(struct zonelist *zonelist)
2401 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2403 zlc = zonelist->zlcache_ptr;
2407 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2410 static bool zone_local(struct zone *local_zone, struct zone *zone)
2412 return local_zone->node == zone->node;
2415 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2417 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2421 #else /* CONFIG_NUMA */
2423 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
2428 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
2429 nodemask_t *allowednodes)
2434 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
2438 static void zlc_clear_zones_full(struct zonelist *zonelist)
2442 static bool zone_local(struct zone *local_zone, struct zone *zone)
2447 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2452 #endif /* CONFIG_NUMA */
2454 static void reset_alloc_batches(struct zone *preferred_zone)
2456 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2459 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2460 high_wmark_pages(zone) - low_wmark_pages(zone) -
2461 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2462 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2463 } while (zone++ != preferred_zone);
2467 * get_page_from_freelist goes through the zonelist trying to allocate
2470 static struct page *
2471 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2472 const struct alloc_context *ac)
2474 struct zonelist *zonelist = ac->zonelist;
2476 struct page *page = NULL;
2478 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
2479 int zlc_active = 0; /* set if using zonelist_cache */
2480 int did_zlc_setup = 0; /* just call zlc_setup() one time */
2481 int nr_fair_skipped = 0;
2482 bool zonelist_rescan;
2485 zonelist_rescan = false;
2488 * Scan zonelist, looking for a zone with enough free.
2489 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2491 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2495 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2496 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2498 if (cpusets_enabled() &&
2499 (alloc_flags & ALLOC_CPUSET) &&
2500 !cpuset_zone_allowed(zone, gfp_mask))
2503 * Distribute pages in proportion to the individual
2504 * zone size to ensure fair page aging. The zone a
2505 * page was allocated in should have no effect on the
2506 * time the page has in memory before being reclaimed.
2508 if (alloc_flags & ALLOC_FAIR) {
2509 if (!zone_local(ac->preferred_zone, zone))
2511 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2517 * When allocating a page cache page for writing, we
2518 * want to get it from a zone that is within its dirty
2519 * limit, such that no single zone holds more than its
2520 * proportional share of globally allowed dirty pages.
2521 * The dirty limits take into account the zone's
2522 * lowmem reserves and high watermark so that kswapd
2523 * should be able to balance it without having to
2524 * write pages from its LRU list.
2526 * This may look like it could increase pressure on
2527 * lower zones by failing allocations in higher zones
2528 * before they are full. But the pages that do spill
2529 * over are limited as the lower zones are protected
2530 * by this very same mechanism. It should not become
2531 * a practical burden to them.
2533 * XXX: For now, allow allocations to potentially
2534 * exceed the per-zone dirty limit in the slowpath
2535 * (spread_dirty_pages unset) before going into reclaim,
2536 * which is important when on a NUMA setup the allowed
2537 * zones are together not big enough to reach the
2538 * global limit. The proper fix for these situations
2539 * will require awareness of zones in the
2540 * dirty-throttling and the flusher threads.
2542 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2545 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2546 if (!zone_watermark_ok(zone, order, mark,
2547 ac->classzone_idx, alloc_flags)) {
2550 /* Checked here to keep the fast path fast */
2551 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2552 if (alloc_flags & ALLOC_NO_WATERMARKS)
2555 if (IS_ENABLED(CONFIG_NUMA) &&
2556 !did_zlc_setup && nr_online_nodes > 1) {
2558 * we do zlc_setup if there are multiple nodes
2559 * and before considering the first zone allowed
2562 allowednodes = zlc_setup(zonelist, alloc_flags);
2567 if (zone_reclaim_mode == 0 ||
2568 !zone_allows_reclaim(ac->preferred_zone, zone))
2569 goto this_zone_full;
2572 * As we may have just activated ZLC, check if the first
2573 * eligible zone has failed zone_reclaim recently.
2575 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2576 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2579 ret = zone_reclaim(zone, gfp_mask, order);
2581 case ZONE_RECLAIM_NOSCAN:
2584 case ZONE_RECLAIM_FULL:
2585 /* scanned but unreclaimable */
2588 /* did we reclaim enough */
2589 if (zone_watermark_ok(zone, order, mark,
2590 ac->classzone_idx, alloc_flags))
2594 * Failed to reclaim enough to meet watermark.
2595 * Only mark the zone full if checking the min
2596 * watermark or if we failed to reclaim just
2597 * 1<<order pages or else the page allocator
2598 * fastpath will prematurely mark zones full
2599 * when the watermark is between the low and
2602 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2603 ret == ZONE_RECLAIM_SOME)
2604 goto this_zone_full;
2611 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2612 gfp_mask, ac->migratetype);
2614 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2619 if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
2620 zlc_mark_zone_full(zonelist, z);
2624 * The first pass makes sure allocations are spread fairly within the
2625 * local node. However, the local node might have free pages left
2626 * after the fairness batches are exhausted, and remote zones haven't
2627 * even been considered yet. Try once more without fairness, and
2628 * include remote zones now, before entering the slowpath and waking
2629 * kswapd: prefer spilling to a remote zone over swapping locally.
2631 if (alloc_flags & ALLOC_FAIR) {
2632 alloc_flags &= ~ALLOC_FAIR;
2633 if (nr_fair_skipped) {
2634 zonelist_rescan = true;
2635 reset_alloc_batches(ac->preferred_zone);
2637 if (nr_online_nodes > 1)
2638 zonelist_rescan = true;
2641 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) {
2642 /* Disable zlc cache for second zonelist scan */
2644 zonelist_rescan = true;
2647 if (zonelist_rescan)
2654 * Large machines with many possible nodes should not always dump per-node
2655 * meminfo in irq context.
2657 static inline bool should_suppress_show_mem(void)
2662 ret = in_interrupt();
2667 static DEFINE_RATELIMIT_STATE(nopage_rs,
2668 DEFAULT_RATELIMIT_INTERVAL,
2669 DEFAULT_RATELIMIT_BURST);
2671 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2673 unsigned int filter = SHOW_MEM_FILTER_NODES;
2675 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2676 debug_guardpage_minorder() > 0)
2680 * This documents exceptions given to allocations in certain
2681 * contexts that are allowed to allocate outside current's set
2684 if (!(gfp_mask & __GFP_NOMEMALLOC))
2685 if (test_thread_flag(TIF_MEMDIE) ||
2686 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2687 filter &= ~SHOW_MEM_FILTER_NODES;
2688 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2689 filter &= ~SHOW_MEM_FILTER_NODES;
2692 struct va_format vaf;
2695 va_start(args, fmt);
2700 pr_warn("%pV", &vaf);
2705 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2706 current->comm, order, gfp_mask);
2709 if (!should_suppress_show_mem())
2713 static inline struct page *
2714 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2715 const struct alloc_context *ac, unsigned long *did_some_progress)
2717 struct oom_control oc = {
2718 .zonelist = ac->zonelist,
2719 .nodemask = ac->nodemask,
2720 .gfp_mask = gfp_mask,
2725 *did_some_progress = 0;
2728 * Acquire the oom lock. If that fails, somebody else is
2729 * making progress for us.
2731 if (!mutex_trylock(&oom_lock)) {
2732 *did_some_progress = 1;
2733 schedule_timeout_uninterruptible(1);
2738 * Go through the zonelist yet one more time, keep very high watermark
2739 * here, this is only to catch a parallel oom killing, we must fail if
2740 * we're still under heavy pressure.
2742 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2743 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2747 if (!(gfp_mask & __GFP_NOFAIL)) {
2748 /* Coredumps can quickly deplete all memory reserves */
2749 if (current->flags & PF_DUMPCORE)
2751 /* The OOM killer will not help higher order allocs */
2752 if (order > PAGE_ALLOC_COSTLY_ORDER)
2754 /* The OOM killer does not needlessly kill tasks for lowmem */
2755 if (ac->high_zoneidx < ZONE_NORMAL)
2757 /* The OOM killer does not compensate for IO-less reclaim */
2758 if (!(gfp_mask & __GFP_FS)) {
2760 * XXX: Page reclaim didn't yield anything,
2761 * and the OOM killer can't be invoked, but
2762 * keep looping as per tradition.
2764 *did_some_progress = 1;
2767 if (pm_suspended_storage())
2769 /* The OOM killer may not free memory on a specific node */
2770 if (gfp_mask & __GFP_THISNODE)
2773 /* Exhausted what can be done so it's blamo time */
2774 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
2775 *did_some_progress = 1;
2777 mutex_unlock(&oom_lock);
2781 #ifdef CONFIG_COMPACTION
2782 /* Try memory compaction for high-order allocations before reclaim */
2783 static struct page *
2784 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2785 int alloc_flags, const struct alloc_context *ac,
2786 enum migrate_mode mode, int *contended_compaction,
2787 bool *deferred_compaction)
2789 unsigned long compact_result;
2795 current->flags |= PF_MEMALLOC;
2796 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2797 mode, contended_compaction);
2798 current->flags &= ~PF_MEMALLOC;
2800 switch (compact_result) {
2801 case COMPACT_DEFERRED:
2802 *deferred_compaction = true;
2804 case COMPACT_SKIPPED:
2811 * At least in one zone compaction wasn't deferred or skipped, so let's
2812 * count a compaction stall
2814 count_vm_event(COMPACTSTALL);
2816 page = get_page_from_freelist(gfp_mask, order,
2817 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2820 struct zone *zone = page_zone(page);
2822 zone->compact_blockskip_flush = false;
2823 compaction_defer_reset(zone, order, true);
2824 count_vm_event(COMPACTSUCCESS);
2829 * It's bad if compaction run occurs and fails. The most likely reason
2830 * is that pages exist, but not enough to satisfy watermarks.
2832 count_vm_event(COMPACTFAIL);
2839 static inline struct page *
2840 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2841 int alloc_flags, const struct alloc_context *ac,
2842 enum migrate_mode mode, int *contended_compaction,
2843 bool *deferred_compaction)
2847 #endif /* CONFIG_COMPACTION */
2849 /* Perform direct synchronous page reclaim */
2851 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
2852 const struct alloc_context *ac)
2854 struct reclaim_state reclaim_state;
2859 /* We now go into synchronous reclaim */
2860 cpuset_memory_pressure_bump();
2861 current->flags |= PF_MEMALLOC;
2862 lockdep_set_current_reclaim_state(gfp_mask);
2863 reclaim_state.reclaimed_slab = 0;
2864 current->reclaim_state = &reclaim_state;
2866 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
2869 current->reclaim_state = NULL;
2870 lockdep_clear_current_reclaim_state();
2871 current->flags &= ~PF_MEMALLOC;
2878 /* The really slow allocator path where we enter direct reclaim */
2879 static inline struct page *
2880 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2881 int alloc_flags, const struct alloc_context *ac,
2882 unsigned long *did_some_progress)
2884 struct page *page = NULL;
2885 bool drained = false;
2887 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
2888 if (unlikely(!(*did_some_progress)))
2891 /* After successful reclaim, reconsider all zones for allocation */
2892 if (IS_ENABLED(CONFIG_NUMA))
2893 zlc_clear_zones_full(ac->zonelist);
2896 page = get_page_from_freelist(gfp_mask, order,
2897 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2900 * If an allocation failed after direct reclaim, it could be because
2901 * pages are pinned on the per-cpu lists. Drain them and try again
2903 if (!page && !drained) {
2904 drain_all_pages(NULL);
2913 * This is called in the allocator slow-path if the allocation request is of
2914 * sufficient urgency to ignore watermarks and take other desperate measures
2916 static inline struct page *
2917 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2918 const struct alloc_context *ac)
2923 page = get_page_from_freelist(gfp_mask, order,
2924 ALLOC_NO_WATERMARKS, ac);
2926 if (!page && gfp_mask & __GFP_NOFAIL)
2927 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC,
2929 } while (!page && (gfp_mask & __GFP_NOFAIL));
2934 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
2939 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
2940 ac->high_zoneidx, ac->nodemask)
2941 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
2945 gfp_to_alloc_flags(gfp_t gfp_mask)
2947 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2948 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
2950 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2951 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2954 * The caller may dip into page reserves a bit more if the caller
2955 * cannot run direct reclaim, or if the caller has realtime scheduling
2956 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2957 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2959 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2963 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2964 * if it can't schedule.
2966 if (!(gfp_mask & __GFP_NOMEMALLOC))
2967 alloc_flags |= ALLOC_HARDER;
2969 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2970 * comment for __cpuset_node_allowed().
2972 alloc_flags &= ~ALLOC_CPUSET;
2973 } else if (unlikely(rt_task(current)) && !in_interrupt())
2974 alloc_flags |= ALLOC_HARDER;
2976 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2977 if (gfp_mask & __GFP_MEMALLOC)
2978 alloc_flags |= ALLOC_NO_WATERMARKS;
2979 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2980 alloc_flags |= ALLOC_NO_WATERMARKS;
2981 else if (!in_interrupt() &&
2982 ((current->flags & PF_MEMALLOC) ||
2983 unlikely(test_thread_flag(TIF_MEMDIE))))
2984 alloc_flags |= ALLOC_NO_WATERMARKS;
2987 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2988 alloc_flags |= ALLOC_CMA;
2993 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2995 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2998 static inline struct page *
2999 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3000 struct alloc_context *ac)
3002 const gfp_t wait = gfp_mask & __GFP_WAIT;
3003 struct page *page = NULL;
3005 unsigned long pages_reclaimed = 0;
3006 unsigned long did_some_progress;
3007 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3008 bool deferred_compaction = false;
3009 int contended_compaction = COMPACT_CONTENDED_NONE;
3012 * In the slowpath, we sanity check order to avoid ever trying to
3013 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3014 * be using allocators in order of preference for an area that is
3017 if (order >= MAX_ORDER) {
3018 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3023 * If this allocation cannot block and it is for a specific node, then
3024 * fail early. There's no need to wakeup kswapd or retry for a
3025 * speculative node-specific allocation.
3027 if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait)
3031 if (!(gfp_mask & __GFP_NO_KSWAPD))
3032 wake_all_kswapds(order, ac);
3035 * OK, we're below the kswapd watermark and have kicked background
3036 * reclaim. Now things get more complex, so set up alloc_flags according
3037 * to how we want to proceed.
3039 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3042 * Find the true preferred zone if the allocation is unconstrained by
3045 if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) {
3046 struct zoneref *preferred_zoneref;
3047 preferred_zoneref = first_zones_zonelist(ac->zonelist,
3048 ac->high_zoneidx, NULL, &ac->preferred_zone);
3049 ac->classzone_idx = zonelist_zone_idx(preferred_zoneref);
3052 /* This is the last chance, in general, before the goto nopage. */
3053 page = get_page_from_freelist(gfp_mask, order,
3054 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3058 /* Allocate without watermarks if the context allows */
3059 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3061 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3062 * the allocation is high priority and these type of
3063 * allocations are system rather than user orientated
3065 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3067 page = __alloc_pages_high_priority(gfp_mask, order, ac);
3074 /* Atomic allocations - we can't balance anything */
3077 * All existing users of the deprecated __GFP_NOFAIL are
3078 * blockable, so warn of any new users that actually allow this
3079 * type of allocation to fail.
3081 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3085 /* Avoid recursion of direct reclaim */
3086 if (current->flags & PF_MEMALLOC)
3089 /* Avoid allocations with no watermarks from looping endlessly */
3090 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3094 * Try direct compaction. The first pass is asynchronous. Subsequent
3095 * attempts after direct reclaim are synchronous
3097 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3099 &contended_compaction,
3100 &deferred_compaction);
3104 /* Checks for THP-specific high-order allocations */
3105 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) {
3107 * If compaction is deferred for high-order allocations, it is
3108 * because sync compaction recently failed. If this is the case
3109 * and the caller requested a THP allocation, we do not want
3110 * to heavily disrupt the system, so we fail the allocation
3111 * instead of entering direct reclaim.
3113 if (deferred_compaction)
3117 * In all zones where compaction was attempted (and not
3118 * deferred or skipped), lock contention has been detected.
3119 * For THP allocation we do not want to disrupt the others
3120 * so we fallback to base pages instead.
3122 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3126 * If compaction was aborted due to need_resched(), we do not
3127 * want to further increase allocation latency, unless it is
3128 * khugepaged trying to collapse.
3130 if (contended_compaction == COMPACT_CONTENDED_SCHED
3131 && !(current->flags & PF_KTHREAD))
3136 * It can become very expensive to allocate transparent hugepages at
3137 * fault, so use asynchronous memory compaction for THP unless it is
3138 * khugepaged trying to collapse.
3140 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE ||
3141 (current->flags & PF_KTHREAD))
3142 migration_mode = MIGRATE_SYNC_LIGHT;
3144 /* Try direct reclaim and then allocating */
3145 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3146 &did_some_progress);
3150 /* Do not loop if specifically requested */
3151 if (gfp_mask & __GFP_NORETRY)
3154 /* Keep reclaiming pages as long as there is reasonable progress */
3155 pages_reclaimed += did_some_progress;
3156 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3157 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3158 /* Wait for some write requests to complete then retry */
3159 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
3163 /* Reclaim has failed us, start killing things */
3164 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3168 /* Retry as long as the OOM killer is making progress */
3169 if (did_some_progress)
3174 * High-order allocations do not necessarily loop after
3175 * direct reclaim and reclaim/compaction depends on compaction
3176 * being called after reclaim so call directly if necessary
3178 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3180 &contended_compaction,
3181 &deferred_compaction);
3185 warn_alloc_failed(gfp_mask, order, NULL);
3191 * This is the 'heart' of the zoned buddy allocator.
3194 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3195 struct zonelist *zonelist, nodemask_t *nodemask)
3197 struct zoneref *preferred_zoneref;
3198 struct page *page = NULL;
3199 unsigned int cpuset_mems_cookie;
3200 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
3201 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
3202 struct alloc_context ac = {
3203 .high_zoneidx = gfp_zone(gfp_mask),
3204 .nodemask = nodemask,
3205 .migratetype = gfpflags_to_migratetype(gfp_mask),
3208 gfp_mask &= gfp_allowed_mask;
3210 lockdep_trace_alloc(gfp_mask);
3212 might_sleep_if(gfp_mask & __GFP_WAIT);
3214 if (should_fail_alloc_page(gfp_mask, order))
3218 * Check the zones suitable for the gfp_mask contain at least one
3219 * valid zone. It's possible to have an empty zonelist as a result
3220 * of __GFP_THISNODE and a memoryless node
3222 if (unlikely(!zonelist->_zonerefs->zone))
3225 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3226 alloc_flags |= ALLOC_CMA;
3229 cpuset_mems_cookie = read_mems_allowed_begin();
3231 /* We set it here, as __alloc_pages_slowpath might have changed it */
3232 ac.zonelist = zonelist;
3234 /* Dirty zone balancing only done in the fast path */
3235 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3237 /* The preferred zone is used for statistics later */
3238 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
3239 ac.nodemask ? : &cpuset_current_mems_allowed,
3240 &ac.preferred_zone);
3241 if (!ac.preferred_zone)
3243 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
3245 /* First allocation attempt */
3246 alloc_mask = gfp_mask|__GFP_HARDWALL;
3247 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3248 if (unlikely(!page)) {
3250 * Runtime PM, block IO and its error handling path
3251 * can deadlock because I/O on the device might not
3254 alloc_mask = memalloc_noio_flags(gfp_mask);
3255 ac.spread_dirty_pages = false;
3257 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3260 if (kmemcheck_enabled && page)
3261 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3263 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3267 * When updating a task's mems_allowed, it is possible to race with
3268 * parallel threads in such a way that an allocation can fail while
3269 * the mask is being updated. If a page allocation is about to fail,
3270 * check if the cpuset changed during allocation and if so, retry.
3272 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
3277 EXPORT_SYMBOL(__alloc_pages_nodemask);
3280 * Common helper functions.
3282 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3287 * __get_free_pages() returns a 32-bit address, which cannot represent
3290 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3292 page = alloc_pages(gfp_mask, order);
3295 return (unsigned long) page_address(page);
3297 EXPORT_SYMBOL(__get_free_pages);
3299 unsigned long get_zeroed_page(gfp_t gfp_mask)
3301 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3303 EXPORT_SYMBOL(get_zeroed_page);
3305 void __free_pages(struct page *page, unsigned int order)
3307 if (put_page_testzero(page)) {
3309 free_hot_cold_page(page, false);
3311 __free_pages_ok(page, order);
3315 EXPORT_SYMBOL(__free_pages);
3317 void free_pages(unsigned long addr, unsigned int order)
3320 VM_BUG_ON(!virt_addr_valid((void *)addr));
3321 __free_pages(virt_to_page((void *)addr), order);
3325 EXPORT_SYMBOL(free_pages);
3329 * An arbitrary-length arbitrary-offset area of memory which resides
3330 * within a 0 or higher order page. Multiple fragments within that page
3331 * are individually refcounted, in the page's reference counter.
3333 * The page_frag functions below provide a simple allocation framework for
3334 * page fragments. This is used by the network stack and network device
3335 * drivers to provide a backing region of memory for use as either an
3336 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3338 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3341 struct page *page = NULL;
3342 gfp_t gfp = gfp_mask;
3344 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3345 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3347 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3348 PAGE_FRAG_CACHE_MAX_ORDER);
3349 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3351 if (unlikely(!page))
3352 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3354 nc->va = page ? page_address(page) : NULL;
3359 void *__alloc_page_frag(struct page_frag_cache *nc,
3360 unsigned int fragsz, gfp_t gfp_mask)
3362 unsigned int size = PAGE_SIZE;
3366 if (unlikely(!nc->va)) {
3368 page = __page_frag_refill(nc, gfp_mask);
3372 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3373 /* if size can vary use size else just use PAGE_SIZE */
3376 /* Even if we own the page, we do not use atomic_set().
3377 * This would break get_page_unless_zero() users.
3379 atomic_add(size - 1, &page->_count);
3381 /* reset page count bias and offset to start of new frag */
3382 nc->pfmemalloc = page_is_pfmemalloc(page);
3383 nc->pagecnt_bias = size;
3387 offset = nc->offset - fragsz;
3388 if (unlikely(offset < 0)) {
3389 page = virt_to_page(nc->va);
3391 if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count))
3394 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3395 /* if size can vary use size else just use PAGE_SIZE */
3398 /* OK, page count is 0, we can safely set it */
3399 atomic_set(&page->_count, size);
3401 /* reset page count bias and offset to start of new frag */
3402 nc->pagecnt_bias = size;
3403 offset = size - fragsz;
3407 nc->offset = offset;
3409 return nc->va + offset;
3411 EXPORT_SYMBOL(__alloc_page_frag);
3414 * Frees a page fragment allocated out of either a compound or order 0 page.
3416 void __free_page_frag(void *addr)
3418 struct page *page = virt_to_head_page(addr);
3420 if (unlikely(put_page_testzero(page)))
3421 __free_pages_ok(page, compound_order(page));
3423 EXPORT_SYMBOL(__free_page_frag);
3426 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3427 * of the current memory cgroup.
3429 * It should be used when the caller would like to use kmalloc, but since the
3430 * allocation is large, it has to fall back to the page allocator.
3432 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3436 page = alloc_pages(gfp_mask, order);
3437 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3438 __free_pages(page, order);
3444 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3448 page = alloc_pages_node(nid, gfp_mask, order);
3449 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3450 __free_pages(page, order);
3457 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3460 void __free_kmem_pages(struct page *page, unsigned int order)
3462 memcg_kmem_uncharge(page, order);
3463 __free_pages(page, order);
3466 void free_kmem_pages(unsigned long addr, unsigned int order)
3469 VM_BUG_ON(!virt_addr_valid((void *)addr));
3470 __free_kmem_pages(virt_to_page((void *)addr), order);
3474 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
3477 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3478 unsigned long used = addr + PAGE_ALIGN(size);
3480 split_page(virt_to_page((void *)addr), order);
3481 while (used < alloc_end) {
3486 return (void *)addr;
3490 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3491 * @size: the number of bytes to allocate
3492 * @gfp_mask: GFP flags for the allocation
3494 * This function is similar to alloc_pages(), except that it allocates the
3495 * minimum number of pages to satisfy the request. alloc_pages() can only
3496 * allocate memory in power-of-two pages.
3498 * This function is also limited by MAX_ORDER.
3500 * Memory allocated by this function must be released by free_pages_exact().
3502 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3504 unsigned int order = get_order(size);
3507 addr = __get_free_pages(gfp_mask, order);
3508 return make_alloc_exact(addr, order, size);
3510 EXPORT_SYMBOL(alloc_pages_exact);
3513 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3515 * @nid: the preferred node ID where memory should be allocated
3516 * @size: the number of bytes to allocate
3517 * @gfp_mask: GFP flags for the allocation
3519 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3522 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3524 unsigned order = get_order(size);
3525 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3528 return make_alloc_exact((unsigned long)page_address(p), order, size);
3532 * free_pages_exact - release memory allocated via alloc_pages_exact()
3533 * @virt: the value returned by alloc_pages_exact.
3534 * @size: size of allocation, same value as passed to alloc_pages_exact().
3536 * Release the memory allocated by a previous call to alloc_pages_exact.
3538 void free_pages_exact(void *virt, size_t size)
3540 unsigned long addr = (unsigned long)virt;
3541 unsigned long end = addr + PAGE_ALIGN(size);
3543 while (addr < end) {
3548 EXPORT_SYMBOL(free_pages_exact);
3551 * nr_free_zone_pages - count number of pages beyond high watermark
3552 * @offset: The zone index of the highest zone
3554 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3555 * high watermark within all zones at or below a given zone index. For each
3556 * zone, the number of pages is calculated as:
3557 * managed_pages - high_pages
3559 static unsigned long nr_free_zone_pages(int offset)
3564 /* Just pick one node, since fallback list is circular */
3565 unsigned long sum = 0;
3567 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3569 for_each_zone_zonelist(zone, z, zonelist, offset) {
3570 unsigned long size = zone->managed_pages;
3571 unsigned long high = high_wmark_pages(zone);
3580 * nr_free_buffer_pages - count number of pages beyond high watermark
3582 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3583 * watermark within ZONE_DMA and ZONE_NORMAL.
3585 unsigned long nr_free_buffer_pages(void)
3587 return nr_free_zone_pages(gfp_zone(GFP_USER));
3589 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3592 * nr_free_pagecache_pages - count number of pages beyond high watermark
3594 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3595 * high watermark within all zones.
3597 unsigned long nr_free_pagecache_pages(void)
3599 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3602 static inline void show_node(struct zone *zone)
3604 if (IS_ENABLED(CONFIG_NUMA))
3605 printk("Node %d ", zone_to_nid(zone));
3608 void si_meminfo(struct sysinfo *val)
3610 val->totalram = totalram_pages;
3611 val->sharedram = global_page_state(NR_SHMEM);
3612 val->freeram = global_page_state(NR_FREE_PAGES);
3613 val->bufferram = nr_blockdev_pages();
3614 val->totalhigh = totalhigh_pages;
3615 val->freehigh = nr_free_highpages();
3616 val->mem_unit = PAGE_SIZE;
3619 EXPORT_SYMBOL(si_meminfo);
3622 void si_meminfo_node(struct sysinfo *val, int nid)
3624 int zone_type; /* needs to be signed */
3625 unsigned long managed_pages = 0;
3626 pg_data_t *pgdat = NODE_DATA(nid);
3628 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3629 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3630 val->totalram = managed_pages;
3631 val->sharedram = node_page_state(nid, NR_SHMEM);
3632 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3633 #ifdef CONFIG_HIGHMEM
3634 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3635 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3641 val->mem_unit = PAGE_SIZE;
3646 * Determine whether the node should be displayed or not, depending on whether
3647 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3649 bool skip_free_areas_node(unsigned int flags, int nid)
3652 unsigned int cpuset_mems_cookie;
3654 if (!(flags & SHOW_MEM_FILTER_NODES))
3658 cpuset_mems_cookie = read_mems_allowed_begin();
3659 ret = !node_isset(nid, cpuset_current_mems_allowed);
3660 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3665 #define K(x) ((x) << (PAGE_SHIFT-10))
3667 static void show_migration_types(unsigned char type)
3669 static const char types[MIGRATE_TYPES] = {
3670 [MIGRATE_UNMOVABLE] = 'U',
3671 [MIGRATE_RECLAIMABLE] = 'E',
3672 [MIGRATE_MOVABLE] = 'M',
3673 [MIGRATE_RESERVE] = 'R',
3675 [MIGRATE_CMA] = 'C',
3677 #ifdef CONFIG_MEMORY_ISOLATION
3678 [MIGRATE_ISOLATE] = 'I',
3681 char tmp[MIGRATE_TYPES + 1];
3685 for (i = 0; i < MIGRATE_TYPES; i++) {
3686 if (type & (1 << i))
3691 printk("(%s) ", tmp);
3695 * Show free area list (used inside shift_scroll-lock stuff)
3696 * We also calculate the percentage fragmentation. We do this by counting the
3697 * memory on each free list with the exception of the first item on the list.
3700 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3703 void show_free_areas(unsigned int filter)
3705 unsigned long free_pcp = 0;
3709 for_each_populated_zone(zone) {
3710 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3713 for_each_online_cpu(cpu)
3714 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3717 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3718 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3719 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3720 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3721 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3722 " free:%lu free_pcp:%lu free_cma:%lu\n",
3723 global_page_state(NR_ACTIVE_ANON),
3724 global_page_state(NR_INACTIVE_ANON),
3725 global_page_state(NR_ISOLATED_ANON),
3726 global_page_state(NR_ACTIVE_FILE),
3727 global_page_state(NR_INACTIVE_FILE),
3728 global_page_state(NR_ISOLATED_FILE),
3729 global_page_state(NR_UNEVICTABLE),
3730 global_page_state(NR_FILE_DIRTY),
3731 global_page_state(NR_WRITEBACK),
3732 global_page_state(NR_UNSTABLE_NFS),
3733 global_page_state(NR_SLAB_RECLAIMABLE),
3734 global_page_state(NR_SLAB_UNRECLAIMABLE),
3735 global_page_state(NR_FILE_MAPPED),
3736 global_page_state(NR_SHMEM),
3737 global_page_state(NR_PAGETABLE),
3738 global_page_state(NR_BOUNCE),
3739 global_page_state(NR_FREE_PAGES),
3741 global_page_state(NR_FREE_CMA_PAGES));
3743 for_each_populated_zone(zone) {
3746 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3750 for_each_online_cpu(cpu)
3751 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3759 " active_anon:%lukB"
3760 " inactive_anon:%lukB"
3761 " active_file:%lukB"
3762 " inactive_file:%lukB"
3763 " unevictable:%lukB"
3764 " isolated(anon):%lukB"
3765 " isolated(file):%lukB"
3773 " slab_reclaimable:%lukB"
3774 " slab_unreclaimable:%lukB"
3775 " kernel_stack:%lukB"
3782 " writeback_tmp:%lukB"
3783 " pages_scanned:%lu"
3784 " all_unreclaimable? %s"
3787 K(zone_page_state(zone, NR_FREE_PAGES)),
3788 K(min_wmark_pages(zone)),
3789 K(low_wmark_pages(zone)),
3790 K(high_wmark_pages(zone)),
3791 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3792 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3793 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3794 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3795 K(zone_page_state(zone, NR_UNEVICTABLE)),
3796 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3797 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3798 K(zone->present_pages),
3799 K(zone->managed_pages),
3800 K(zone_page_state(zone, NR_MLOCK)),
3801 K(zone_page_state(zone, NR_FILE_DIRTY)),
3802 K(zone_page_state(zone, NR_WRITEBACK)),
3803 K(zone_page_state(zone, NR_FILE_MAPPED)),
3804 K(zone_page_state(zone, NR_SHMEM)),
3805 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3806 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3807 zone_page_state(zone, NR_KERNEL_STACK) *
3809 K(zone_page_state(zone, NR_PAGETABLE)),
3810 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3811 K(zone_page_state(zone, NR_BOUNCE)),
3813 K(this_cpu_read(zone->pageset->pcp.count)),
3814 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3815 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3816 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3817 (!zone_reclaimable(zone) ? "yes" : "no")
3819 printk("lowmem_reserve[]:");
3820 for (i = 0; i < MAX_NR_ZONES; i++)
3821 printk(" %ld", zone->lowmem_reserve[i]);
3825 for_each_populated_zone(zone) {
3826 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3827 unsigned char types[MAX_ORDER];
3829 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3832 printk("%s: ", zone->name);
3834 spin_lock_irqsave(&zone->lock, flags);
3835 for (order = 0; order < MAX_ORDER; order++) {
3836 struct free_area *area = &zone->free_area[order];
3839 nr[order] = area->nr_free;
3840 total += nr[order] << order;
3843 for (type = 0; type < MIGRATE_TYPES; type++) {
3844 if (!list_empty(&area->free_list[type]))
3845 types[order] |= 1 << type;
3848 spin_unlock_irqrestore(&zone->lock, flags);
3849 for (order = 0; order < MAX_ORDER; order++) {
3850 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3852 show_migration_types(types[order]);
3854 printk("= %lukB\n", K(total));
3857 hugetlb_show_meminfo();
3859 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3861 show_swap_cache_info();
3864 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3866 zoneref->zone = zone;
3867 zoneref->zone_idx = zone_idx(zone);
3871 * Builds allocation fallback zone lists.
3873 * Add all populated zones of a node to the zonelist.
3875 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3879 enum zone_type zone_type = MAX_NR_ZONES;
3883 zone = pgdat->node_zones + zone_type;
3884 if (populated_zone(zone)) {
3885 zoneref_set_zone(zone,
3886 &zonelist->_zonerefs[nr_zones++]);
3887 check_highest_zone(zone_type);
3889 } while (zone_type);
3897 * 0 = automatic detection of better ordering.
3898 * 1 = order by ([node] distance, -zonetype)
3899 * 2 = order by (-zonetype, [node] distance)
3901 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3902 * the same zonelist. So only NUMA can configure this param.
3904 #define ZONELIST_ORDER_DEFAULT 0
3905 #define ZONELIST_ORDER_NODE 1
3906 #define ZONELIST_ORDER_ZONE 2
3908 /* zonelist order in the kernel.
3909 * set_zonelist_order() will set this to NODE or ZONE.
3911 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3912 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3916 /* The value user specified ....changed by config */
3917 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3918 /* string for sysctl */
3919 #define NUMA_ZONELIST_ORDER_LEN 16
3920 char numa_zonelist_order[16] = "default";
3923 * interface for configure zonelist ordering.
3924 * command line option "numa_zonelist_order"
3925 * = "[dD]efault - default, automatic configuration.
3926 * = "[nN]ode - order by node locality, then by zone within node
3927 * = "[zZ]one - order by zone, then by locality within zone
3930 static int __parse_numa_zonelist_order(char *s)
3932 if (*s == 'd' || *s == 'D') {
3933 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3934 } else if (*s == 'n' || *s == 'N') {
3935 user_zonelist_order = ZONELIST_ORDER_NODE;
3936 } else if (*s == 'z' || *s == 'Z') {
3937 user_zonelist_order = ZONELIST_ORDER_ZONE;
3940 "Ignoring invalid numa_zonelist_order value: "
3947 static __init int setup_numa_zonelist_order(char *s)
3954 ret = __parse_numa_zonelist_order(s);
3956 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3960 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3963 * sysctl handler for numa_zonelist_order
3965 int numa_zonelist_order_handler(struct ctl_table *table, int write,
3966 void __user *buffer, size_t *length,
3969 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3971 static DEFINE_MUTEX(zl_order_mutex);
3973 mutex_lock(&zl_order_mutex);
3975 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3979 strcpy(saved_string, (char *)table->data);
3981 ret = proc_dostring(table, write, buffer, length, ppos);
3985 int oldval = user_zonelist_order;
3987 ret = __parse_numa_zonelist_order((char *)table->data);
3990 * bogus value. restore saved string
3992 strncpy((char *)table->data, saved_string,
3993 NUMA_ZONELIST_ORDER_LEN);
3994 user_zonelist_order = oldval;
3995 } else if (oldval != user_zonelist_order) {
3996 mutex_lock(&zonelists_mutex);
3997 build_all_zonelists(NULL, NULL);
3998 mutex_unlock(&zonelists_mutex);
4002 mutex_unlock(&zl_order_mutex);
4007 #define MAX_NODE_LOAD (nr_online_nodes)
4008 static int node_load[MAX_NUMNODES];
4011 * find_next_best_node - find the next node that should appear in a given node's fallback list
4012 * @node: node whose fallback list we're appending
4013 * @used_node_mask: nodemask_t of already used nodes
4015 * We use a number of factors to determine which is the next node that should
4016 * appear on a given node's fallback list. The node should not have appeared
4017 * already in @node's fallback list, and it should be the next closest node
4018 * according to the distance array (which contains arbitrary distance values
4019 * from each node to each node in the system), and should also prefer nodes
4020 * with no CPUs, since presumably they'll have very little allocation pressure
4021 * on them otherwise.
4022 * It returns -1 if no node is found.
4024 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4027 int min_val = INT_MAX;
4028 int best_node = NUMA_NO_NODE;
4029 const struct cpumask *tmp = cpumask_of_node(0);
4031 /* Use the local node if we haven't already */
4032 if (!node_isset(node, *used_node_mask)) {
4033 node_set(node, *used_node_mask);
4037 for_each_node_state(n, N_MEMORY) {
4039 /* Don't want a node to appear more than once */
4040 if (node_isset(n, *used_node_mask))
4043 /* Use the distance array to find the distance */
4044 val = node_distance(node, n);
4046 /* Penalize nodes under us ("prefer the next node") */
4049 /* Give preference to headless and unused nodes */
4050 tmp = cpumask_of_node(n);
4051 if (!cpumask_empty(tmp))
4052 val += PENALTY_FOR_NODE_WITH_CPUS;
4054 /* Slight preference for less loaded node */
4055 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4056 val += node_load[n];
4058 if (val < min_val) {
4065 node_set(best_node, *used_node_mask);
4072 * Build zonelists ordered by node and zones within node.
4073 * This results in maximum locality--normal zone overflows into local
4074 * DMA zone, if any--but risks exhausting DMA zone.
4076 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4079 struct zonelist *zonelist;
4081 zonelist = &pgdat->node_zonelists[0];
4082 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4084 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4085 zonelist->_zonerefs[j].zone = NULL;
4086 zonelist->_zonerefs[j].zone_idx = 0;
4090 * Build gfp_thisnode zonelists
4092 static void build_thisnode_zonelists(pg_data_t *pgdat)
4095 struct zonelist *zonelist;
4097 zonelist = &pgdat->node_zonelists[1];
4098 j = build_zonelists_node(pgdat, zonelist, 0);
4099 zonelist->_zonerefs[j].zone = NULL;
4100 zonelist->_zonerefs[j].zone_idx = 0;
4104 * Build zonelists ordered by zone and nodes within zones.
4105 * This results in conserving DMA zone[s] until all Normal memory is
4106 * exhausted, but results in overflowing to remote node while memory
4107 * may still exist in local DMA zone.
4109 static int node_order[MAX_NUMNODES];
4111 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4114 int zone_type; /* needs to be signed */
4116 struct zonelist *zonelist;
4118 zonelist = &pgdat->node_zonelists[0];
4120 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4121 for (j = 0; j < nr_nodes; j++) {
4122 node = node_order[j];
4123 z = &NODE_DATA(node)->node_zones[zone_type];
4124 if (populated_zone(z)) {
4126 &zonelist->_zonerefs[pos++]);
4127 check_highest_zone(zone_type);
4131 zonelist->_zonerefs[pos].zone = NULL;
4132 zonelist->_zonerefs[pos].zone_idx = 0;
4135 #if defined(CONFIG_64BIT)
4137 * Devices that require DMA32/DMA are relatively rare and do not justify a
4138 * penalty to every machine in case the specialised case applies. Default
4139 * to Node-ordering on 64-bit NUMA machines
4141 static int default_zonelist_order(void)
4143 return ZONELIST_ORDER_NODE;
4147 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4148 * by the kernel. If processes running on node 0 deplete the low memory zone
4149 * then reclaim will occur more frequency increasing stalls and potentially
4150 * be easier to OOM if a large percentage of the zone is under writeback or
4151 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4152 * Hence, default to zone ordering on 32-bit.
4154 static int default_zonelist_order(void)
4156 return ZONELIST_ORDER_ZONE;
4158 #endif /* CONFIG_64BIT */
4160 static void set_zonelist_order(void)
4162 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4163 current_zonelist_order = default_zonelist_order();
4165 current_zonelist_order = user_zonelist_order;
4168 static void build_zonelists(pg_data_t *pgdat)
4172 nodemask_t used_mask;
4173 int local_node, prev_node;
4174 struct zonelist *zonelist;
4175 int order = current_zonelist_order;
4177 /* initialize zonelists */
4178 for (i = 0; i < MAX_ZONELISTS; i++) {
4179 zonelist = pgdat->node_zonelists + i;
4180 zonelist->_zonerefs[0].zone = NULL;
4181 zonelist->_zonerefs[0].zone_idx = 0;
4184 /* NUMA-aware ordering of nodes */
4185 local_node = pgdat->node_id;
4186 load = nr_online_nodes;
4187 prev_node = local_node;
4188 nodes_clear(used_mask);
4190 memset(node_order, 0, sizeof(node_order));
4193 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4195 * We don't want to pressure a particular node.
4196 * So adding penalty to the first node in same
4197 * distance group to make it round-robin.
4199 if (node_distance(local_node, node) !=
4200 node_distance(local_node, prev_node))
4201 node_load[node] = load;
4205 if (order == ZONELIST_ORDER_NODE)
4206 build_zonelists_in_node_order(pgdat, node);
4208 node_order[j++] = node; /* remember order */
4211 if (order == ZONELIST_ORDER_ZONE) {
4212 /* calculate node order -- i.e., DMA last! */
4213 build_zonelists_in_zone_order(pgdat, j);
4216 build_thisnode_zonelists(pgdat);
4219 /* Construct the zonelist performance cache - see further mmzone.h */
4220 static void build_zonelist_cache(pg_data_t *pgdat)
4222 struct zonelist *zonelist;
4223 struct zonelist_cache *zlc;
4226 zonelist = &pgdat->node_zonelists[0];
4227 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
4228 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
4229 for (z = zonelist->_zonerefs; z->zone; z++)
4230 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
4233 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4235 * Return node id of node used for "local" allocations.
4236 * I.e., first node id of first zone in arg node's generic zonelist.
4237 * Used for initializing percpu 'numa_mem', which is used primarily
4238 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4240 int local_memory_node(int node)
4244 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4245 gfp_zone(GFP_KERNEL),
4252 #else /* CONFIG_NUMA */
4254 static void set_zonelist_order(void)
4256 current_zonelist_order = ZONELIST_ORDER_ZONE;
4259 static void build_zonelists(pg_data_t *pgdat)
4261 int node, local_node;
4263 struct zonelist *zonelist;
4265 local_node = pgdat->node_id;
4267 zonelist = &pgdat->node_zonelists[0];
4268 j = build_zonelists_node(pgdat, zonelist, 0);
4271 * Now we build the zonelist so that it contains the zones
4272 * of all the other nodes.
4273 * We don't want to pressure a particular node, so when
4274 * building the zones for node N, we make sure that the
4275 * zones coming right after the local ones are those from
4276 * node N+1 (modulo N)
4278 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4279 if (!node_online(node))
4281 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4283 for (node = 0; node < local_node; node++) {
4284 if (!node_online(node))
4286 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4289 zonelist->_zonerefs[j].zone = NULL;
4290 zonelist->_zonerefs[j].zone_idx = 0;
4293 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
4294 static void build_zonelist_cache(pg_data_t *pgdat)
4296 pgdat->node_zonelists[0].zlcache_ptr = NULL;
4299 #endif /* CONFIG_NUMA */
4302 * Boot pageset table. One per cpu which is going to be used for all
4303 * zones and all nodes. The parameters will be set in such a way
4304 * that an item put on a list will immediately be handed over to
4305 * the buddy list. This is safe since pageset manipulation is done
4306 * with interrupts disabled.
4308 * The boot_pagesets must be kept even after bootup is complete for
4309 * unused processors and/or zones. They do play a role for bootstrapping
4310 * hotplugged processors.
4312 * zoneinfo_show() and maybe other functions do
4313 * not check if the processor is online before following the pageset pointer.
4314 * Other parts of the kernel may not check if the zone is available.
4316 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4317 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4318 static void setup_zone_pageset(struct zone *zone);
4321 * Global mutex to protect against size modification of zonelists
4322 * as well as to serialize pageset setup for the new populated zone.
4324 DEFINE_MUTEX(zonelists_mutex);
4326 /* return values int ....just for stop_machine() */
4327 static int __build_all_zonelists(void *data)
4331 pg_data_t *self = data;
4334 memset(node_load, 0, sizeof(node_load));
4337 if (self && !node_online(self->node_id)) {
4338 build_zonelists(self);
4339 build_zonelist_cache(self);
4342 for_each_online_node(nid) {
4343 pg_data_t *pgdat = NODE_DATA(nid);
4345 build_zonelists(pgdat);
4346 build_zonelist_cache(pgdat);
4350 * Initialize the boot_pagesets that are going to be used
4351 * for bootstrapping processors. The real pagesets for
4352 * each zone will be allocated later when the per cpu
4353 * allocator is available.
4355 * boot_pagesets are used also for bootstrapping offline
4356 * cpus if the system is already booted because the pagesets
4357 * are needed to initialize allocators on a specific cpu too.
4358 * F.e. the percpu allocator needs the page allocator which
4359 * needs the percpu allocator in order to allocate its pagesets
4360 * (a chicken-egg dilemma).
4362 for_each_possible_cpu(cpu) {
4363 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4365 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4367 * We now know the "local memory node" for each node--
4368 * i.e., the node of the first zone in the generic zonelist.
4369 * Set up numa_mem percpu variable for on-line cpus. During
4370 * boot, only the boot cpu should be on-line; we'll init the
4371 * secondary cpus' numa_mem as they come on-line. During
4372 * node/memory hotplug, we'll fixup all on-line cpus.
4374 if (cpu_online(cpu))
4375 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4382 static noinline void __init
4383 build_all_zonelists_init(void)
4385 __build_all_zonelists(NULL);
4386 mminit_verify_zonelist();
4387 cpuset_init_current_mems_allowed();
4391 * Called with zonelists_mutex held always
4392 * unless system_state == SYSTEM_BOOTING.
4394 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4395 * [we're only called with non-NULL zone through __meminit paths] and
4396 * (2) call of __init annotated helper build_all_zonelists_init
4397 * [protected by SYSTEM_BOOTING].
4399 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4401 set_zonelist_order();
4403 if (system_state == SYSTEM_BOOTING) {
4404 build_all_zonelists_init();
4406 #ifdef CONFIG_MEMORY_HOTPLUG
4408 setup_zone_pageset(zone);
4410 /* we have to stop all cpus to guarantee there is no user
4412 stop_machine(__build_all_zonelists, pgdat, NULL);
4413 /* cpuset refresh routine should be here */
4415 vm_total_pages = nr_free_pagecache_pages();
4417 * Disable grouping by mobility if the number of pages in the
4418 * system is too low to allow the mechanism to work. It would be
4419 * more accurate, but expensive to check per-zone. This check is
4420 * made on memory-hotadd so a system can start with mobility
4421 * disabled and enable it later
4423 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4424 page_group_by_mobility_disabled = 1;
4426 page_group_by_mobility_disabled = 0;
4428 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4429 "Total pages: %ld\n",
4431 zonelist_order_name[current_zonelist_order],
4432 page_group_by_mobility_disabled ? "off" : "on",
4435 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4440 * Helper functions to size the waitqueue hash table.
4441 * Essentially these want to choose hash table sizes sufficiently
4442 * large so that collisions trying to wait on pages are rare.
4443 * But in fact, the number of active page waitqueues on typical
4444 * systems is ridiculously low, less than 200. So this is even
4445 * conservative, even though it seems large.
4447 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4448 * waitqueues, i.e. the size of the waitq table given the number of pages.
4450 #define PAGES_PER_WAITQUEUE 256
4452 #ifndef CONFIG_MEMORY_HOTPLUG
4453 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4455 unsigned long size = 1;
4457 pages /= PAGES_PER_WAITQUEUE;
4459 while (size < pages)
4463 * Once we have dozens or even hundreds of threads sleeping
4464 * on IO we've got bigger problems than wait queue collision.
4465 * Limit the size of the wait table to a reasonable size.
4467 size = min(size, 4096UL);
4469 return max(size, 4UL);
4473 * A zone's size might be changed by hot-add, so it is not possible to determine
4474 * a suitable size for its wait_table. So we use the maximum size now.
4476 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4478 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4479 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4480 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4482 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4483 * or more by the traditional way. (See above). It equals:
4485 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4486 * ia64(16K page size) : = ( 8G + 4M)byte.
4487 * powerpc (64K page size) : = (32G +16M)byte.
4489 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4496 * This is an integer logarithm so that shifts can be used later
4497 * to extract the more random high bits from the multiplicative
4498 * hash function before the remainder is taken.
4500 static inline unsigned long wait_table_bits(unsigned long size)
4506 * Check if a pageblock contains reserved pages
4508 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
4512 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4513 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
4520 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
4521 * of blocks reserved is based on min_wmark_pages(zone). The memory within
4522 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
4523 * higher will lead to a bigger reserve which will get freed as contiguous
4524 * blocks as reclaim kicks in
4526 static void setup_zone_migrate_reserve(struct zone *zone)
4528 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
4530 unsigned long block_migratetype;
4535 * Get the start pfn, end pfn and the number of blocks to reserve
4536 * We have to be careful to be aligned to pageblock_nr_pages to
4537 * make sure that we always check pfn_valid for the first page in
4540 start_pfn = zone->zone_start_pfn;
4541 end_pfn = zone_end_pfn(zone);
4542 start_pfn = roundup(start_pfn, pageblock_nr_pages);
4543 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
4547 * Reserve blocks are generally in place to help high-order atomic
4548 * allocations that are short-lived. A min_free_kbytes value that
4549 * would result in more than 2 reserve blocks for atomic allocations
4550 * is assumed to be in place to help anti-fragmentation for the
4551 * future allocation of hugepages at runtime.
4553 reserve = min(2, reserve);
4554 old_reserve = zone->nr_migrate_reserve_block;
4556 /* When memory hot-add, we almost always need to do nothing */
4557 if (reserve == old_reserve)
4559 zone->nr_migrate_reserve_block = reserve;
4561 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
4562 if (!early_page_nid_uninitialised(pfn, zone_to_nid(zone)))
4565 if (!pfn_valid(pfn))
4567 page = pfn_to_page(pfn);
4569 /* Watch out for overlapping nodes */
4570 if (page_to_nid(page) != zone_to_nid(zone))
4573 block_migratetype = get_pageblock_migratetype(page);
4575 /* Only test what is necessary when the reserves are not met */
4578 * Blocks with reserved pages will never free, skip
4581 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
4582 if (pageblock_is_reserved(pfn, block_end_pfn))
4585 /* If this block is reserved, account for it */
4586 if (block_migratetype == MIGRATE_RESERVE) {
4591 /* Suitable for reserving if this block is movable */
4592 if (block_migratetype == MIGRATE_MOVABLE) {
4593 set_pageblock_migratetype(page,
4595 move_freepages_block(zone, page,
4600 } else if (!old_reserve) {
4602 * At boot time we don't need to scan the whole zone
4603 * for turning off MIGRATE_RESERVE.
4609 * If the reserve is met and this is a previous reserved block,
4612 if (block_migratetype == MIGRATE_RESERVE) {
4613 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4614 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4620 * Initially all pages are reserved - free ones are freed
4621 * up by free_all_bootmem() once the early boot process is
4622 * done. Non-atomic initialization, single-pass.
4624 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4625 unsigned long start_pfn, enum memmap_context context)
4627 pg_data_t *pgdat = NODE_DATA(nid);
4628 unsigned long end_pfn = start_pfn + size;
4631 unsigned long nr_initialised = 0;
4633 if (highest_memmap_pfn < end_pfn - 1)
4634 highest_memmap_pfn = end_pfn - 1;
4636 z = &pgdat->node_zones[zone];
4637 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4639 * There can be holes in boot-time mem_map[]s
4640 * handed to this function. They do not
4641 * exist on hotplugged memory.
4643 if (context == MEMMAP_EARLY) {
4644 if (!early_pfn_valid(pfn))
4646 if (!early_pfn_in_nid(pfn, nid))
4648 if (!update_defer_init(pgdat, pfn, end_pfn,
4654 * Mark the block movable so that blocks are reserved for
4655 * movable at startup. This will force kernel allocations
4656 * to reserve their blocks rather than leaking throughout
4657 * the address space during boot when many long-lived
4658 * kernel allocations are made. Later some blocks near
4659 * the start are marked MIGRATE_RESERVE by
4660 * setup_zone_migrate_reserve()
4662 * bitmap is created for zone's valid pfn range. but memmap
4663 * can be created for invalid pages (for alignment)
4664 * check here not to call set_pageblock_migratetype() against
4667 if (!(pfn & (pageblock_nr_pages - 1))) {
4668 struct page *page = pfn_to_page(pfn);
4670 __init_single_page(page, pfn, zone, nid);
4671 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4673 __init_single_pfn(pfn, zone, nid);
4678 static void __meminit zone_init_free_lists(struct zone *zone)
4680 unsigned int order, t;
4681 for_each_migratetype_order(order, t) {
4682 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4683 zone->free_area[order].nr_free = 0;
4687 #ifndef __HAVE_ARCH_MEMMAP_INIT
4688 #define memmap_init(size, nid, zone, start_pfn) \
4689 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4692 static int zone_batchsize(struct zone *zone)
4698 * The per-cpu-pages pools are set to around 1000th of the
4699 * size of the zone. But no more than 1/2 of a meg.
4701 * OK, so we don't know how big the cache is. So guess.
4703 batch = zone->managed_pages / 1024;
4704 if (batch * PAGE_SIZE > 512 * 1024)
4705 batch = (512 * 1024) / PAGE_SIZE;
4706 batch /= 4; /* We effectively *= 4 below */
4711 * Clamp the batch to a 2^n - 1 value. Having a power
4712 * of 2 value was found to be more likely to have
4713 * suboptimal cache aliasing properties in some cases.
4715 * For example if 2 tasks are alternately allocating
4716 * batches of pages, one task can end up with a lot
4717 * of pages of one half of the possible page colors
4718 * and the other with pages of the other colors.
4720 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4725 /* The deferral and batching of frees should be suppressed under NOMMU
4728 * The problem is that NOMMU needs to be able to allocate large chunks
4729 * of contiguous memory as there's no hardware page translation to
4730 * assemble apparent contiguous memory from discontiguous pages.
4732 * Queueing large contiguous runs of pages for batching, however,
4733 * causes the pages to actually be freed in smaller chunks. As there
4734 * can be a significant delay between the individual batches being
4735 * recycled, this leads to the once large chunks of space being
4736 * fragmented and becoming unavailable for high-order allocations.
4743 * pcp->high and pcp->batch values are related and dependent on one another:
4744 * ->batch must never be higher then ->high.
4745 * The following function updates them in a safe manner without read side
4748 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4749 * those fields changing asynchronously (acording the the above rule).
4751 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4752 * outside of boot time (or some other assurance that no concurrent updaters
4755 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4756 unsigned long batch)
4758 /* start with a fail safe value for batch */
4762 /* Update high, then batch, in order */
4769 /* a companion to pageset_set_high() */
4770 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4772 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4775 static void pageset_init(struct per_cpu_pageset *p)
4777 struct per_cpu_pages *pcp;
4780 memset(p, 0, sizeof(*p));
4784 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4785 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4788 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4791 pageset_set_batch(p, batch);
4795 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4796 * to the value high for the pageset p.
4798 static void pageset_set_high(struct per_cpu_pageset *p,
4801 unsigned long batch = max(1UL, high / 4);
4802 if ((high / 4) > (PAGE_SHIFT * 8))
4803 batch = PAGE_SHIFT * 8;
4805 pageset_update(&p->pcp, high, batch);
4808 static void pageset_set_high_and_batch(struct zone *zone,
4809 struct per_cpu_pageset *pcp)
4811 if (percpu_pagelist_fraction)
4812 pageset_set_high(pcp,
4813 (zone->managed_pages /
4814 percpu_pagelist_fraction));
4816 pageset_set_batch(pcp, zone_batchsize(zone));
4819 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4821 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4824 pageset_set_high_and_batch(zone, pcp);
4827 static void __meminit setup_zone_pageset(struct zone *zone)
4830 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4831 for_each_possible_cpu(cpu)
4832 zone_pageset_init(zone, cpu);
4836 * Allocate per cpu pagesets and initialize them.
4837 * Before this call only boot pagesets were available.
4839 void __init setup_per_cpu_pageset(void)
4843 for_each_populated_zone(zone)
4844 setup_zone_pageset(zone);
4847 static noinline __init_refok
4848 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4854 * The per-page waitqueue mechanism uses hashed waitqueues
4857 zone->wait_table_hash_nr_entries =
4858 wait_table_hash_nr_entries(zone_size_pages);
4859 zone->wait_table_bits =
4860 wait_table_bits(zone->wait_table_hash_nr_entries);
4861 alloc_size = zone->wait_table_hash_nr_entries
4862 * sizeof(wait_queue_head_t);
4864 if (!slab_is_available()) {
4865 zone->wait_table = (wait_queue_head_t *)
4866 memblock_virt_alloc_node_nopanic(
4867 alloc_size, zone->zone_pgdat->node_id);
4870 * This case means that a zone whose size was 0 gets new memory
4871 * via memory hot-add.
4872 * But it may be the case that a new node was hot-added. In
4873 * this case vmalloc() will not be able to use this new node's
4874 * memory - this wait_table must be initialized to use this new
4875 * node itself as well.
4876 * To use this new node's memory, further consideration will be
4879 zone->wait_table = vmalloc(alloc_size);
4881 if (!zone->wait_table)
4884 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4885 init_waitqueue_head(zone->wait_table + i);
4890 static __meminit void zone_pcp_init(struct zone *zone)
4893 * per cpu subsystem is not up at this point. The following code
4894 * relies on the ability of the linker to provide the
4895 * offset of a (static) per cpu variable into the per cpu area.
4897 zone->pageset = &boot_pageset;
4899 if (populated_zone(zone))
4900 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4901 zone->name, zone->present_pages,
4902 zone_batchsize(zone));
4905 int __meminit init_currently_empty_zone(struct zone *zone,
4906 unsigned long zone_start_pfn,
4909 struct pglist_data *pgdat = zone->zone_pgdat;
4911 ret = zone_wait_table_init(zone, size);
4914 pgdat->nr_zones = zone_idx(zone) + 1;
4916 zone->zone_start_pfn = zone_start_pfn;
4918 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4919 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4921 (unsigned long)zone_idx(zone),
4922 zone_start_pfn, (zone_start_pfn + size));
4924 zone_init_free_lists(zone);
4929 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4930 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4933 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4935 int __meminit __early_pfn_to_nid(unsigned long pfn,
4936 struct mminit_pfnnid_cache *state)
4938 unsigned long start_pfn, end_pfn;
4941 if (state->last_start <= pfn && pfn < state->last_end)
4942 return state->last_nid;
4944 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4946 state->last_start = start_pfn;
4947 state->last_end = end_pfn;
4948 state->last_nid = nid;
4953 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4956 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4957 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4958 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4960 * If an architecture guarantees that all ranges registered contain no holes
4961 * and may be freed, this this function may be used instead of calling
4962 * memblock_free_early_nid() manually.
4964 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4966 unsigned long start_pfn, end_pfn;
4969 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4970 start_pfn = min(start_pfn, max_low_pfn);
4971 end_pfn = min(end_pfn, max_low_pfn);
4973 if (start_pfn < end_pfn)
4974 memblock_free_early_nid(PFN_PHYS(start_pfn),
4975 (end_pfn - start_pfn) << PAGE_SHIFT,
4981 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4982 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4984 * If an architecture guarantees that all ranges registered contain no holes and may
4985 * be freed, this function may be used instead of calling memory_present() manually.
4987 void __init sparse_memory_present_with_active_regions(int nid)
4989 unsigned long start_pfn, end_pfn;
4992 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4993 memory_present(this_nid, start_pfn, end_pfn);
4997 * get_pfn_range_for_nid - Return the start and end page frames for a node
4998 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4999 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5000 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5002 * It returns the start and end page frame of a node based on information
5003 * provided by memblock_set_node(). If called for a node
5004 * with no available memory, a warning is printed and the start and end
5007 void __meminit get_pfn_range_for_nid(unsigned int nid,
5008 unsigned long *start_pfn, unsigned long *end_pfn)
5010 unsigned long this_start_pfn, this_end_pfn;
5016 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5017 *start_pfn = min(*start_pfn, this_start_pfn);
5018 *end_pfn = max(*end_pfn, this_end_pfn);
5021 if (*start_pfn == -1UL)
5026 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5027 * assumption is made that zones within a node are ordered in monotonic
5028 * increasing memory addresses so that the "highest" populated zone is used
5030 static void __init find_usable_zone_for_movable(void)
5033 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5034 if (zone_index == ZONE_MOVABLE)
5037 if (arch_zone_highest_possible_pfn[zone_index] >
5038 arch_zone_lowest_possible_pfn[zone_index])
5042 VM_BUG_ON(zone_index == -1);
5043 movable_zone = zone_index;
5047 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5048 * because it is sized independent of architecture. Unlike the other zones,
5049 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5050 * in each node depending on the size of each node and how evenly kernelcore
5051 * is distributed. This helper function adjusts the zone ranges
5052 * provided by the architecture for a given node by using the end of the
5053 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5054 * zones within a node are in order of monotonic increases memory addresses
5056 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5057 unsigned long zone_type,
5058 unsigned long node_start_pfn,
5059 unsigned long node_end_pfn,
5060 unsigned long *zone_start_pfn,
5061 unsigned long *zone_end_pfn)
5063 /* Only adjust if ZONE_MOVABLE is on this node */
5064 if (zone_movable_pfn[nid]) {
5065 /* Size ZONE_MOVABLE */
5066 if (zone_type == ZONE_MOVABLE) {
5067 *zone_start_pfn = zone_movable_pfn[nid];
5068 *zone_end_pfn = min(node_end_pfn,
5069 arch_zone_highest_possible_pfn[movable_zone]);
5071 /* Adjust for ZONE_MOVABLE starting within this range */
5072 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
5073 *zone_end_pfn > zone_movable_pfn[nid]) {
5074 *zone_end_pfn = zone_movable_pfn[nid];
5076 /* Check if this whole range is within ZONE_MOVABLE */
5077 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5078 *zone_start_pfn = *zone_end_pfn;
5083 * Return the number of pages a zone spans in a node, including holes
5084 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5086 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5087 unsigned long zone_type,
5088 unsigned long node_start_pfn,
5089 unsigned long node_end_pfn,
5090 unsigned long *ignored)
5092 unsigned long zone_start_pfn, zone_end_pfn;
5094 /* When hotadd a new node from cpu_up(), the node should be empty */
5095 if (!node_start_pfn && !node_end_pfn)
5098 /* Get the start and end of the zone */
5099 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5100 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5101 adjust_zone_range_for_zone_movable(nid, zone_type,
5102 node_start_pfn, node_end_pfn,
5103 &zone_start_pfn, &zone_end_pfn);
5105 /* Check that this node has pages within the zone's required range */
5106 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
5109 /* Move the zone boundaries inside the node if necessary */
5110 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
5111 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
5113 /* Return the spanned pages */
5114 return zone_end_pfn - zone_start_pfn;
5118 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5119 * then all holes in the requested range will be accounted for.
5121 unsigned long __meminit __absent_pages_in_range(int nid,
5122 unsigned long range_start_pfn,
5123 unsigned long range_end_pfn)
5125 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5126 unsigned long start_pfn, end_pfn;
5129 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5130 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5131 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5132 nr_absent -= end_pfn - start_pfn;
5138 * absent_pages_in_range - Return number of page frames in holes within a range
5139 * @start_pfn: The start PFN to start searching for holes
5140 * @end_pfn: The end PFN to stop searching for holes
5142 * It returns the number of pages frames in memory holes within a range.
5144 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5145 unsigned long end_pfn)
5147 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5150 /* Return the number of page frames in holes in a zone on a node */
5151 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5152 unsigned long zone_type,
5153 unsigned long node_start_pfn,
5154 unsigned long node_end_pfn,
5155 unsigned long *ignored)
5157 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5158 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5159 unsigned long zone_start_pfn, zone_end_pfn;
5161 /* When hotadd a new node from cpu_up(), the node should be empty */
5162 if (!node_start_pfn && !node_end_pfn)
5165 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5166 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5168 adjust_zone_range_for_zone_movable(nid, zone_type,
5169 node_start_pfn, node_end_pfn,
5170 &zone_start_pfn, &zone_end_pfn);
5171 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5174 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5175 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5176 unsigned long zone_type,
5177 unsigned long node_start_pfn,
5178 unsigned long node_end_pfn,
5179 unsigned long *zones_size)
5181 return zones_size[zone_type];
5184 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5185 unsigned long zone_type,
5186 unsigned long node_start_pfn,
5187 unsigned long node_end_pfn,
5188 unsigned long *zholes_size)
5193 return zholes_size[zone_type];
5196 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5198 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5199 unsigned long node_start_pfn,
5200 unsigned long node_end_pfn,
5201 unsigned long *zones_size,
5202 unsigned long *zholes_size)
5204 unsigned long realtotalpages = 0, totalpages = 0;
5207 for (i = 0; i < MAX_NR_ZONES; i++) {
5208 struct zone *zone = pgdat->node_zones + i;
5209 unsigned long size, real_size;
5211 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5215 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5216 node_start_pfn, node_end_pfn,
5218 zone->spanned_pages = size;
5219 zone->present_pages = real_size;
5222 realtotalpages += real_size;
5225 pgdat->node_spanned_pages = totalpages;
5226 pgdat->node_present_pages = realtotalpages;
5227 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5231 #ifndef CONFIG_SPARSEMEM
5233 * Calculate the size of the zone->blockflags rounded to an unsigned long
5234 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5235 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5236 * round what is now in bits to nearest long in bits, then return it in
5239 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5241 unsigned long usemapsize;
5243 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5244 usemapsize = roundup(zonesize, pageblock_nr_pages);
5245 usemapsize = usemapsize >> pageblock_order;
5246 usemapsize *= NR_PAGEBLOCK_BITS;
5247 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5249 return usemapsize / 8;
5252 static void __init setup_usemap(struct pglist_data *pgdat,
5254 unsigned long zone_start_pfn,
5255 unsigned long zonesize)
5257 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5258 zone->pageblock_flags = NULL;
5260 zone->pageblock_flags =
5261 memblock_virt_alloc_node_nopanic(usemapsize,
5265 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5266 unsigned long zone_start_pfn, unsigned long zonesize) {}
5267 #endif /* CONFIG_SPARSEMEM */
5269 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5271 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5272 void __paginginit set_pageblock_order(void)
5276 /* Check that pageblock_nr_pages has not already been setup */
5277 if (pageblock_order)
5280 if (HPAGE_SHIFT > PAGE_SHIFT)
5281 order = HUGETLB_PAGE_ORDER;
5283 order = MAX_ORDER - 1;
5286 * Assume the largest contiguous order of interest is a huge page.
5287 * This value may be variable depending on boot parameters on IA64 and
5290 pageblock_order = order;
5292 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5295 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5296 * is unused as pageblock_order is set at compile-time. See
5297 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5300 void __paginginit set_pageblock_order(void)
5304 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5306 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5307 unsigned long present_pages)
5309 unsigned long pages = spanned_pages;
5312 * Provide a more accurate estimation if there are holes within
5313 * the zone and SPARSEMEM is in use. If there are holes within the
5314 * zone, each populated memory region may cost us one or two extra
5315 * memmap pages due to alignment because memmap pages for each
5316 * populated regions may not naturally algined on page boundary.
5317 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5319 if (spanned_pages > present_pages + (present_pages >> 4) &&
5320 IS_ENABLED(CONFIG_SPARSEMEM))
5321 pages = present_pages;
5323 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5327 * Set up the zone data structures:
5328 * - mark all pages reserved
5329 * - mark all memory queues empty
5330 * - clear the memory bitmaps
5332 * NOTE: pgdat should get zeroed by caller.
5334 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5337 int nid = pgdat->node_id;
5338 unsigned long zone_start_pfn = pgdat->node_start_pfn;
5341 pgdat_resize_init(pgdat);
5342 #ifdef CONFIG_NUMA_BALANCING
5343 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5344 pgdat->numabalancing_migrate_nr_pages = 0;
5345 pgdat->numabalancing_migrate_next_window = jiffies;
5347 init_waitqueue_head(&pgdat->kswapd_wait);
5348 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5349 pgdat_page_ext_init(pgdat);
5351 for (j = 0; j < MAX_NR_ZONES; j++) {
5352 struct zone *zone = pgdat->node_zones + j;
5353 unsigned long size, realsize, freesize, memmap_pages;
5355 size = zone->spanned_pages;
5356 realsize = freesize = zone->present_pages;
5359 * Adjust freesize so that it accounts for how much memory
5360 * is used by this zone for memmap. This affects the watermark
5361 * and per-cpu initialisations
5363 memmap_pages = calc_memmap_size(size, realsize);
5364 if (!is_highmem_idx(j)) {
5365 if (freesize >= memmap_pages) {
5366 freesize -= memmap_pages;
5369 " %s zone: %lu pages used for memmap\n",
5370 zone_names[j], memmap_pages);
5373 " %s zone: %lu pages exceeds freesize %lu\n",
5374 zone_names[j], memmap_pages, freesize);
5377 /* Account for reserved pages */
5378 if (j == 0 && freesize > dma_reserve) {
5379 freesize -= dma_reserve;
5380 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5381 zone_names[0], dma_reserve);
5384 if (!is_highmem_idx(j))
5385 nr_kernel_pages += freesize;
5386 /* Charge for highmem memmap if there are enough kernel pages */
5387 else if (nr_kernel_pages > memmap_pages * 2)
5388 nr_kernel_pages -= memmap_pages;
5389 nr_all_pages += freesize;
5392 * Set an approximate value for lowmem here, it will be adjusted
5393 * when the bootmem allocator frees pages into the buddy system.
5394 * And all highmem pages will be managed by the buddy system.
5396 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5399 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5401 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5403 zone->name = zone_names[j];
5404 spin_lock_init(&zone->lock);
5405 spin_lock_init(&zone->lru_lock);
5406 zone_seqlock_init(zone);
5407 zone->zone_pgdat = pgdat;
5408 zone_pcp_init(zone);
5410 /* For bootup, initialized properly in watermark setup */
5411 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5413 lruvec_init(&zone->lruvec);
5417 set_pageblock_order();
5418 setup_usemap(pgdat, zone, zone_start_pfn, size);
5419 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5421 memmap_init(size, nid, j, zone_start_pfn);
5422 zone_start_pfn += size;
5426 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5428 unsigned long __maybe_unused offset = 0;
5430 /* Skip empty nodes */
5431 if (!pgdat->node_spanned_pages)
5434 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5435 /* ia64 gets its own node_mem_map, before this, without bootmem */
5436 if (!pgdat->node_mem_map) {
5437 unsigned long size, start, end;
5441 * The zone's endpoints aren't required to be MAX_ORDER
5442 * aligned but the node_mem_map endpoints must be in order
5443 * for the buddy allocator to function correctly.
5445 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5446 offset = pgdat->node_start_pfn - start;
5447 end = pgdat_end_pfn(pgdat);
5448 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5449 size = (end - start) * sizeof(struct page);
5450 map = alloc_remap(pgdat->node_id, size);
5452 map = memblock_virt_alloc_node_nopanic(size,
5454 pgdat->node_mem_map = map + offset;
5456 #ifndef CONFIG_NEED_MULTIPLE_NODES
5458 * With no DISCONTIG, the global mem_map is just set as node 0's
5460 if (pgdat == NODE_DATA(0)) {
5461 mem_map = NODE_DATA(0)->node_mem_map;
5462 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5463 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5465 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5468 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5471 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5472 unsigned long node_start_pfn, unsigned long *zholes_size)
5474 pg_data_t *pgdat = NODE_DATA(nid);
5475 unsigned long start_pfn = 0;
5476 unsigned long end_pfn = 0;
5478 /* pg_data_t should be reset to zero when it's allocated */
5479 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5481 reset_deferred_meminit(pgdat);
5482 pgdat->node_id = nid;
5483 pgdat->node_start_pfn = node_start_pfn;
5484 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5485 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5486 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5487 (u64)start_pfn << PAGE_SHIFT,
5488 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5490 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5491 zones_size, zholes_size);
5493 alloc_node_mem_map(pgdat);
5494 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5495 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5496 nid, (unsigned long)pgdat,
5497 (unsigned long)pgdat->node_mem_map);
5500 free_area_init_core(pgdat);
5503 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5505 #if MAX_NUMNODES > 1
5507 * Figure out the number of possible node ids.
5509 void __init setup_nr_node_ids(void)
5511 unsigned int highest;
5513 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5514 nr_node_ids = highest + 1;
5519 * node_map_pfn_alignment - determine the maximum internode alignment
5521 * This function should be called after node map is populated and sorted.
5522 * It calculates the maximum power of two alignment which can distinguish
5525 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5526 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5527 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5528 * shifted, 1GiB is enough and this function will indicate so.
5530 * This is used to test whether pfn -> nid mapping of the chosen memory
5531 * model has fine enough granularity to avoid incorrect mapping for the
5532 * populated node map.
5534 * Returns the determined alignment in pfn's. 0 if there is no alignment
5535 * requirement (single node).
5537 unsigned long __init node_map_pfn_alignment(void)
5539 unsigned long accl_mask = 0, last_end = 0;
5540 unsigned long start, end, mask;
5544 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5545 if (!start || last_nid < 0 || last_nid == nid) {
5552 * Start with a mask granular enough to pin-point to the
5553 * start pfn and tick off bits one-by-one until it becomes
5554 * too coarse to separate the current node from the last.
5556 mask = ~((1 << __ffs(start)) - 1);
5557 while (mask && last_end <= (start & (mask << 1)))
5560 /* accumulate all internode masks */
5564 /* convert mask to number of pages */
5565 return ~accl_mask + 1;
5568 /* Find the lowest pfn for a node */
5569 static unsigned long __init find_min_pfn_for_node(int nid)
5571 unsigned long min_pfn = ULONG_MAX;
5572 unsigned long start_pfn;
5575 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5576 min_pfn = min(min_pfn, start_pfn);
5578 if (min_pfn == ULONG_MAX) {
5580 "Could not find start_pfn for node %d\n", nid);
5588 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5590 * It returns the minimum PFN based on information provided via
5591 * memblock_set_node().
5593 unsigned long __init find_min_pfn_with_active_regions(void)
5595 return find_min_pfn_for_node(MAX_NUMNODES);
5599 * early_calculate_totalpages()
5600 * Sum pages in active regions for movable zone.
5601 * Populate N_MEMORY for calculating usable_nodes.
5603 static unsigned long __init early_calculate_totalpages(void)
5605 unsigned long totalpages = 0;
5606 unsigned long start_pfn, end_pfn;
5609 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5610 unsigned long pages = end_pfn - start_pfn;
5612 totalpages += pages;
5614 node_set_state(nid, N_MEMORY);
5620 * Find the PFN the Movable zone begins in each node. Kernel memory
5621 * is spread evenly between nodes as long as the nodes have enough
5622 * memory. When they don't, some nodes will have more kernelcore than
5625 static void __init find_zone_movable_pfns_for_nodes(void)
5628 unsigned long usable_startpfn;
5629 unsigned long kernelcore_node, kernelcore_remaining;
5630 /* save the state before borrow the nodemask */
5631 nodemask_t saved_node_state = node_states[N_MEMORY];
5632 unsigned long totalpages = early_calculate_totalpages();
5633 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5634 struct memblock_region *r;
5636 /* Need to find movable_zone earlier when movable_node is specified. */
5637 find_usable_zone_for_movable();
5640 * If movable_node is specified, ignore kernelcore and movablecore
5643 if (movable_node_is_enabled()) {
5644 for_each_memblock(memory, r) {
5645 if (!memblock_is_hotpluggable(r))
5650 usable_startpfn = PFN_DOWN(r->base);
5651 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5652 min(usable_startpfn, zone_movable_pfn[nid]) :
5660 * If movablecore=nn[KMG] was specified, calculate what size of
5661 * kernelcore that corresponds so that memory usable for
5662 * any allocation type is evenly spread. If both kernelcore
5663 * and movablecore are specified, then the value of kernelcore
5664 * will be used for required_kernelcore if it's greater than
5665 * what movablecore would have allowed.
5667 if (required_movablecore) {
5668 unsigned long corepages;
5671 * Round-up so that ZONE_MOVABLE is at least as large as what
5672 * was requested by the user
5674 required_movablecore =
5675 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5676 required_movablecore = min(totalpages, required_movablecore);
5677 corepages = totalpages - required_movablecore;
5679 required_kernelcore = max(required_kernelcore, corepages);
5683 * If kernelcore was not specified or kernelcore size is larger
5684 * than totalpages, there is no ZONE_MOVABLE.
5686 if (!required_kernelcore || required_kernelcore >= totalpages)
5689 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5690 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5693 /* Spread kernelcore memory as evenly as possible throughout nodes */
5694 kernelcore_node = required_kernelcore / usable_nodes;
5695 for_each_node_state(nid, N_MEMORY) {
5696 unsigned long start_pfn, end_pfn;
5699 * Recalculate kernelcore_node if the division per node
5700 * now exceeds what is necessary to satisfy the requested
5701 * amount of memory for the kernel
5703 if (required_kernelcore < kernelcore_node)
5704 kernelcore_node = required_kernelcore / usable_nodes;
5707 * As the map is walked, we track how much memory is usable
5708 * by the kernel using kernelcore_remaining. When it is
5709 * 0, the rest of the node is usable by ZONE_MOVABLE
5711 kernelcore_remaining = kernelcore_node;
5713 /* Go through each range of PFNs within this node */
5714 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5715 unsigned long size_pages;
5717 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5718 if (start_pfn >= end_pfn)
5721 /* Account for what is only usable for kernelcore */
5722 if (start_pfn < usable_startpfn) {
5723 unsigned long kernel_pages;
5724 kernel_pages = min(end_pfn, usable_startpfn)
5727 kernelcore_remaining -= min(kernel_pages,
5728 kernelcore_remaining);
5729 required_kernelcore -= min(kernel_pages,
5730 required_kernelcore);
5732 /* Continue if range is now fully accounted */
5733 if (end_pfn <= usable_startpfn) {
5736 * Push zone_movable_pfn to the end so
5737 * that if we have to rebalance
5738 * kernelcore across nodes, we will
5739 * not double account here
5741 zone_movable_pfn[nid] = end_pfn;
5744 start_pfn = usable_startpfn;
5748 * The usable PFN range for ZONE_MOVABLE is from
5749 * start_pfn->end_pfn. Calculate size_pages as the
5750 * number of pages used as kernelcore
5752 size_pages = end_pfn - start_pfn;
5753 if (size_pages > kernelcore_remaining)
5754 size_pages = kernelcore_remaining;
5755 zone_movable_pfn[nid] = start_pfn + size_pages;
5758 * Some kernelcore has been met, update counts and
5759 * break if the kernelcore for this node has been
5762 required_kernelcore -= min(required_kernelcore,
5764 kernelcore_remaining -= size_pages;
5765 if (!kernelcore_remaining)
5771 * If there is still required_kernelcore, we do another pass with one
5772 * less node in the count. This will push zone_movable_pfn[nid] further
5773 * along on the nodes that still have memory until kernelcore is
5777 if (usable_nodes && required_kernelcore > usable_nodes)
5781 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5782 for (nid = 0; nid < MAX_NUMNODES; nid++)
5783 zone_movable_pfn[nid] =
5784 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5787 /* restore the node_state */
5788 node_states[N_MEMORY] = saved_node_state;
5791 /* Any regular or high memory on that node ? */
5792 static void check_for_memory(pg_data_t *pgdat, int nid)
5794 enum zone_type zone_type;
5796 if (N_MEMORY == N_NORMAL_MEMORY)
5799 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5800 struct zone *zone = &pgdat->node_zones[zone_type];
5801 if (populated_zone(zone)) {
5802 node_set_state(nid, N_HIGH_MEMORY);
5803 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5804 zone_type <= ZONE_NORMAL)
5805 node_set_state(nid, N_NORMAL_MEMORY);
5812 * free_area_init_nodes - Initialise all pg_data_t and zone data
5813 * @max_zone_pfn: an array of max PFNs for each zone
5815 * This will call free_area_init_node() for each active node in the system.
5816 * Using the page ranges provided by memblock_set_node(), the size of each
5817 * zone in each node and their holes is calculated. If the maximum PFN
5818 * between two adjacent zones match, it is assumed that the zone is empty.
5819 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5820 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5821 * starts where the previous one ended. For example, ZONE_DMA32 starts
5822 * at arch_max_dma_pfn.
5824 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5826 unsigned long start_pfn, end_pfn;
5829 /* Record where the zone boundaries are */
5830 memset(arch_zone_lowest_possible_pfn, 0,
5831 sizeof(arch_zone_lowest_possible_pfn));
5832 memset(arch_zone_highest_possible_pfn, 0,
5833 sizeof(arch_zone_highest_possible_pfn));
5834 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5835 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5836 for (i = 1; i < MAX_NR_ZONES; i++) {
5837 if (i == ZONE_MOVABLE)
5839 arch_zone_lowest_possible_pfn[i] =
5840 arch_zone_highest_possible_pfn[i-1];
5841 arch_zone_highest_possible_pfn[i] =
5842 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5844 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5845 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5847 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5848 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5849 find_zone_movable_pfns_for_nodes();
5851 /* Print out the zone ranges */
5852 pr_info("Zone ranges:\n");
5853 for (i = 0; i < MAX_NR_ZONES; i++) {
5854 if (i == ZONE_MOVABLE)
5856 pr_info(" %-8s ", zone_names[i]);
5857 if (arch_zone_lowest_possible_pfn[i] ==
5858 arch_zone_highest_possible_pfn[i])
5861 pr_cont("[mem %#018Lx-%#018Lx]\n",
5862 (u64)arch_zone_lowest_possible_pfn[i]
5864 ((u64)arch_zone_highest_possible_pfn[i]
5865 << PAGE_SHIFT) - 1);
5868 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5869 pr_info("Movable zone start for each node\n");
5870 for (i = 0; i < MAX_NUMNODES; i++) {
5871 if (zone_movable_pfn[i])
5872 pr_info(" Node %d: %#018Lx\n", i,
5873 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
5876 /* Print out the early node map */
5877 pr_info("Early memory node ranges\n");
5878 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5879 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
5880 (u64)start_pfn << PAGE_SHIFT,
5881 ((u64)end_pfn << PAGE_SHIFT) - 1);
5883 /* Initialise every node */
5884 mminit_verify_pageflags_layout();
5885 setup_nr_node_ids();
5886 for_each_online_node(nid) {
5887 pg_data_t *pgdat = NODE_DATA(nid);
5888 free_area_init_node(nid, NULL,
5889 find_min_pfn_for_node(nid), NULL);
5891 /* Any memory on that node */
5892 if (pgdat->node_present_pages)
5893 node_set_state(nid, N_MEMORY);
5894 check_for_memory(pgdat, nid);
5898 static int __init cmdline_parse_core(char *p, unsigned long *core)
5900 unsigned long long coremem;
5904 coremem = memparse(p, &p);
5905 *core = coremem >> PAGE_SHIFT;
5907 /* Paranoid check that UL is enough for the coremem value */
5908 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5914 * kernelcore=size sets the amount of memory for use for allocations that
5915 * cannot be reclaimed or migrated.
5917 static int __init cmdline_parse_kernelcore(char *p)
5919 return cmdline_parse_core(p, &required_kernelcore);
5923 * movablecore=size sets the amount of memory for use for allocations that
5924 * can be reclaimed or migrated.
5926 static int __init cmdline_parse_movablecore(char *p)
5928 return cmdline_parse_core(p, &required_movablecore);
5931 early_param("kernelcore", cmdline_parse_kernelcore);
5932 early_param("movablecore", cmdline_parse_movablecore);
5934 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5936 void adjust_managed_page_count(struct page *page, long count)
5938 spin_lock(&managed_page_count_lock);
5939 page_zone(page)->managed_pages += count;
5940 totalram_pages += count;
5941 #ifdef CONFIG_HIGHMEM
5942 if (PageHighMem(page))
5943 totalhigh_pages += count;
5945 spin_unlock(&managed_page_count_lock);
5947 EXPORT_SYMBOL(adjust_managed_page_count);
5949 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5952 unsigned long pages = 0;
5954 start = (void *)PAGE_ALIGN((unsigned long)start);
5955 end = (void *)((unsigned long)end & PAGE_MASK);
5956 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5957 if ((unsigned int)poison <= 0xFF)
5958 memset(pos, poison, PAGE_SIZE);
5959 free_reserved_page(virt_to_page(pos));
5963 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5964 s, pages << (PAGE_SHIFT - 10), start, end);
5968 EXPORT_SYMBOL(free_reserved_area);
5970 #ifdef CONFIG_HIGHMEM
5971 void free_highmem_page(struct page *page)
5973 __free_reserved_page(page);
5975 page_zone(page)->managed_pages++;
5981 void __init mem_init_print_info(const char *str)
5983 unsigned long physpages, codesize, datasize, rosize, bss_size;
5984 unsigned long init_code_size, init_data_size;
5986 physpages = get_num_physpages();
5987 codesize = _etext - _stext;
5988 datasize = _edata - _sdata;
5989 rosize = __end_rodata - __start_rodata;
5990 bss_size = __bss_stop - __bss_start;
5991 init_data_size = __init_end - __init_begin;
5992 init_code_size = _einittext - _sinittext;
5995 * Detect special cases and adjust section sizes accordingly:
5996 * 1) .init.* may be embedded into .data sections
5997 * 2) .init.text.* may be out of [__init_begin, __init_end],
5998 * please refer to arch/tile/kernel/vmlinux.lds.S.
5999 * 3) .rodata.* may be embedded into .text or .data sections.
6001 #define adj_init_size(start, end, size, pos, adj) \
6003 if (start <= pos && pos < end && size > adj) \
6007 adj_init_size(__init_begin, __init_end, init_data_size,
6008 _sinittext, init_code_size);
6009 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6010 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6011 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6012 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6014 #undef adj_init_size
6016 pr_info("Memory: %luK/%luK available "
6017 "(%luK kernel code, %luK rwdata, %luK rodata, "
6018 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
6019 #ifdef CONFIG_HIGHMEM
6023 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
6024 codesize >> 10, datasize >> 10, rosize >> 10,
6025 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6026 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10),
6027 totalcma_pages << (PAGE_SHIFT-10),
6028 #ifdef CONFIG_HIGHMEM
6029 totalhigh_pages << (PAGE_SHIFT-10),
6031 str ? ", " : "", str ? str : "");
6035 * set_dma_reserve - set the specified number of pages reserved in the first zone
6036 * @new_dma_reserve: The number of pages to mark reserved
6038 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6039 * In the DMA zone, a significant percentage may be consumed by kernel image
6040 * and other unfreeable allocations which can skew the watermarks badly. This
6041 * function may optionally be used to account for unfreeable pages in the
6042 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6043 * smaller per-cpu batchsize.
6045 void __init set_dma_reserve(unsigned long new_dma_reserve)
6047 dma_reserve = new_dma_reserve;
6050 void __init free_area_init(unsigned long *zones_size)
6052 free_area_init_node(0, zones_size,
6053 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6056 static int page_alloc_cpu_notify(struct notifier_block *self,
6057 unsigned long action, void *hcpu)
6059 int cpu = (unsigned long)hcpu;
6061 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6062 lru_add_drain_cpu(cpu);
6066 * Spill the event counters of the dead processor
6067 * into the current processors event counters.
6068 * This artificially elevates the count of the current
6071 vm_events_fold_cpu(cpu);
6074 * Zero the differential counters of the dead processor
6075 * so that the vm statistics are consistent.
6077 * This is only okay since the processor is dead and cannot
6078 * race with what we are doing.
6080 cpu_vm_stats_fold(cpu);
6085 void __init page_alloc_init(void)
6087 hotcpu_notifier(page_alloc_cpu_notify, 0);
6091 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6092 * or min_free_kbytes changes.
6094 static void calculate_totalreserve_pages(void)
6096 struct pglist_data *pgdat;
6097 unsigned long reserve_pages = 0;
6098 enum zone_type i, j;
6100 for_each_online_pgdat(pgdat) {
6101 for (i = 0; i < MAX_NR_ZONES; i++) {
6102 struct zone *zone = pgdat->node_zones + i;
6105 /* Find valid and maximum lowmem_reserve in the zone */
6106 for (j = i; j < MAX_NR_ZONES; j++) {
6107 if (zone->lowmem_reserve[j] > max)
6108 max = zone->lowmem_reserve[j];
6111 /* we treat the high watermark as reserved pages. */
6112 max += high_wmark_pages(zone);
6114 if (max > zone->managed_pages)
6115 max = zone->managed_pages;
6116 reserve_pages += max;
6118 * Lowmem reserves are not available to
6119 * GFP_HIGHUSER page cache allocations and
6120 * kswapd tries to balance zones to their high
6121 * watermark. As a result, neither should be
6122 * regarded as dirtyable memory, to prevent a
6123 * situation where reclaim has to clean pages
6124 * in order to balance the zones.
6126 zone->dirty_balance_reserve = max;
6129 dirty_balance_reserve = reserve_pages;
6130 totalreserve_pages = reserve_pages;
6134 * setup_per_zone_lowmem_reserve - called whenever
6135 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6136 * has a correct pages reserved value, so an adequate number of
6137 * pages are left in the zone after a successful __alloc_pages().
6139 static void setup_per_zone_lowmem_reserve(void)
6141 struct pglist_data *pgdat;
6142 enum zone_type j, idx;
6144 for_each_online_pgdat(pgdat) {
6145 for (j = 0; j < MAX_NR_ZONES; j++) {
6146 struct zone *zone = pgdat->node_zones + j;
6147 unsigned long managed_pages = zone->managed_pages;
6149 zone->lowmem_reserve[j] = 0;
6153 struct zone *lower_zone;
6157 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6158 sysctl_lowmem_reserve_ratio[idx] = 1;
6160 lower_zone = pgdat->node_zones + idx;
6161 lower_zone->lowmem_reserve[j] = managed_pages /
6162 sysctl_lowmem_reserve_ratio[idx];
6163 managed_pages += lower_zone->managed_pages;
6168 /* update totalreserve_pages */
6169 calculate_totalreserve_pages();
6172 static void __setup_per_zone_wmarks(void)
6174 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6175 unsigned long lowmem_pages = 0;
6177 unsigned long flags;
6179 /* Calculate total number of !ZONE_HIGHMEM pages */
6180 for_each_zone(zone) {
6181 if (!is_highmem(zone))
6182 lowmem_pages += zone->managed_pages;
6185 for_each_zone(zone) {
6188 spin_lock_irqsave(&zone->lock, flags);
6189 tmp = (u64)pages_min * zone->managed_pages;
6190 do_div(tmp, lowmem_pages);
6191 if (is_highmem(zone)) {
6193 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6194 * need highmem pages, so cap pages_min to a small
6197 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6198 * deltas control asynch page reclaim, and so should
6199 * not be capped for highmem.
6201 unsigned long min_pages;
6203 min_pages = zone->managed_pages / 1024;
6204 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6205 zone->watermark[WMARK_MIN] = min_pages;
6208 * If it's a lowmem zone, reserve a number of pages
6209 * proportionate to the zone's size.
6211 zone->watermark[WMARK_MIN] = tmp;
6214 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
6215 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
6217 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6218 high_wmark_pages(zone) - low_wmark_pages(zone) -
6219 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6221 setup_zone_migrate_reserve(zone);
6222 spin_unlock_irqrestore(&zone->lock, flags);
6225 /* update totalreserve_pages */
6226 calculate_totalreserve_pages();
6230 * setup_per_zone_wmarks - called when min_free_kbytes changes
6231 * or when memory is hot-{added|removed}
6233 * Ensures that the watermark[min,low,high] values for each zone are set
6234 * correctly with respect to min_free_kbytes.
6236 void setup_per_zone_wmarks(void)
6238 mutex_lock(&zonelists_mutex);
6239 __setup_per_zone_wmarks();
6240 mutex_unlock(&zonelists_mutex);
6244 * The inactive anon list should be small enough that the VM never has to
6245 * do too much work, but large enough that each inactive page has a chance
6246 * to be referenced again before it is swapped out.
6248 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6249 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6250 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6251 * the anonymous pages are kept on the inactive list.
6254 * memory ratio inactive anon
6255 * -------------------------------------
6264 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6266 unsigned int gb, ratio;
6268 /* Zone size in gigabytes */
6269 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6271 ratio = int_sqrt(10 * gb);
6275 zone->inactive_ratio = ratio;
6278 static void __meminit setup_per_zone_inactive_ratio(void)
6283 calculate_zone_inactive_ratio(zone);
6287 * Initialise min_free_kbytes.
6289 * For small machines we want it small (128k min). For large machines
6290 * we want it large (64MB max). But it is not linear, because network
6291 * bandwidth does not increase linearly with machine size. We use
6293 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6294 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6310 int __meminit init_per_zone_wmark_min(void)
6312 unsigned long lowmem_kbytes;
6313 int new_min_free_kbytes;
6315 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6316 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6318 if (new_min_free_kbytes > user_min_free_kbytes) {
6319 min_free_kbytes = new_min_free_kbytes;
6320 if (min_free_kbytes < 128)
6321 min_free_kbytes = 128;
6322 if (min_free_kbytes > 65536)
6323 min_free_kbytes = 65536;
6325 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6326 new_min_free_kbytes, user_min_free_kbytes);
6328 setup_per_zone_wmarks();
6329 refresh_zone_stat_thresholds();
6330 setup_per_zone_lowmem_reserve();
6331 setup_per_zone_inactive_ratio();
6334 module_init(init_per_zone_wmark_min)
6337 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6338 * that we can call two helper functions whenever min_free_kbytes
6341 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6342 void __user *buffer, size_t *length, loff_t *ppos)
6346 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6351 user_min_free_kbytes = min_free_kbytes;
6352 setup_per_zone_wmarks();
6358 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6359 void __user *buffer, size_t *length, loff_t *ppos)
6364 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6369 zone->min_unmapped_pages = (zone->managed_pages *
6370 sysctl_min_unmapped_ratio) / 100;
6374 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6375 void __user *buffer, size_t *length, loff_t *ppos)
6380 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6385 zone->min_slab_pages = (zone->managed_pages *
6386 sysctl_min_slab_ratio) / 100;
6392 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6393 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6394 * whenever sysctl_lowmem_reserve_ratio changes.
6396 * The reserve ratio obviously has absolutely no relation with the
6397 * minimum watermarks. The lowmem reserve ratio can only make sense
6398 * if in function of the boot time zone sizes.
6400 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6401 void __user *buffer, size_t *length, loff_t *ppos)
6403 proc_dointvec_minmax(table, write, buffer, length, ppos);
6404 setup_per_zone_lowmem_reserve();
6409 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6410 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6411 * pagelist can have before it gets flushed back to buddy allocator.
6413 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6414 void __user *buffer, size_t *length, loff_t *ppos)
6417 int old_percpu_pagelist_fraction;
6420 mutex_lock(&pcp_batch_high_lock);
6421 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6423 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6424 if (!write || ret < 0)
6427 /* Sanity checking to avoid pcp imbalance */
6428 if (percpu_pagelist_fraction &&
6429 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6430 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6436 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6439 for_each_populated_zone(zone) {
6442 for_each_possible_cpu(cpu)
6443 pageset_set_high_and_batch(zone,
6444 per_cpu_ptr(zone->pageset, cpu));
6447 mutex_unlock(&pcp_batch_high_lock);
6452 int hashdist = HASHDIST_DEFAULT;
6454 static int __init set_hashdist(char *str)
6458 hashdist = simple_strtoul(str, &str, 0);
6461 __setup("hashdist=", set_hashdist);
6465 * allocate a large system hash table from bootmem
6466 * - it is assumed that the hash table must contain an exact power-of-2
6467 * quantity of entries
6468 * - limit is the number of hash buckets, not the total allocation size
6470 void *__init alloc_large_system_hash(const char *tablename,
6471 unsigned long bucketsize,
6472 unsigned long numentries,
6475 unsigned int *_hash_shift,
6476 unsigned int *_hash_mask,
6477 unsigned long low_limit,
6478 unsigned long high_limit)
6480 unsigned long long max = high_limit;
6481 unsigned long log2qty, size;
6484 /* allow the kernel cmdline to have a say */
6486 /* round applicable memory size up to nearest megabyte */
6487 numentries = nr_kernel_pages;
6489 /* It isn't necessary when PAGE_SIZE >= 1MB */
6490 if (PAGE_SHIFT < 20)
6491 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6493 /* limit to 1 bucket per 2^scale bytes of low memory */
6494 if (scale > PAGE_SHIFT)
6495 numentries >>= (scale - PAGE_SHIFT);
6497 numentries <<= (PAGE_SHIFT - scale);
6499 /* Make sure we've got at least a 0-order allocation.. */
6500 if (unlikely(flags & HASH_SMALL)) {
6501 /* Makes no sense without HASH_EARLY */
6502 WARN_ON(!(flags & HASH_EARLY));
6503 if (!(numentries >> *_hash_shift)) {
6504 numentries = 1UL << *_hash_shift;
6505 BUG_ON(!numentries);
6507 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6508 numentries = PAGE_SIZE / bucketsize;
6510 numentries = roundup_pow_of_two(numentries);
6512 /* limit allocation size to 1/16 total memory by default */
6514 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6515 do_div(max, bucketsize);
6517 max = min(max, 0x80000000ULL);
6519 if (numentries < low_limit)
6520 numentries = low_limit;
6521 if (numentries > max)
6524 log2qty = ilog2(numentries);
6527 size = bucketsize << log2qty;
6528 if (flags & HASH_EARLY)
6529 table = memblock_virt_alloc_nopanic(size, 0);
6531 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6534 * If bucketsize is not a power-of-two, we may free
6535 * some pages at the end of hash table which
6536 * alloc_pages_exact() automatically does
6538 if (get_order(size) < MAX_ORDER) {
6539 table = alloc_pages_exact(size, GFP_ATOMIC);
6540 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6543 } while (!table && size > PAGE_SIZE && --log2qty);
6546 panic("Failed to allocate %s hash table\n", tablename);
6548 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6551 ilog2(size) - PAGE_SHIFT,
6555 *_hash_shift = log2qty;
6557 *_hash_mask = (1 << log2qty) - 1;
6562 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6563 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6566 #ifdef CONFIG_SPARSEMEM
6567 return __pfn_to_section(pfn)->pageblock_flags;
6569 return zone->pageblock_flags;
6570 #endif /* CONFIG_SPARSEMEM */
6573 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6575 #ifdef CONFIG_SPARSEMEM
6576 pfn &= (PAGES_PER_SECTION-1);
6577 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6579 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6580 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6581 #endif /* CONFIG_SPARSEMEM */
6585 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6586 * @page: The page within the block of interest
6587 * @pfn: The target page frame number
6588 * @end_bitidx: The last bit of interest to retrieve
6589 * @mask: mask of bits that the caller is interested in
6591 * Return: pageblock_bits flags
6593 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6594 unsigned long end_bitidx,
6598 unsigned long *bitmap;
6599 unsigned long bitidx, word_bitidx;
6602 zone = page_zone(page);
6603 bitmap = get_pageblock_bitmap(zone, pfn);
6604 bitidx = pfn_to_bitidx(zone, pfn);
6605 word_bitidx = bitidx / BITS_PER_LONG;
6606 bitidx &= (BITS_PER_LONG-1);
6608 word = bitmap[word_bitidx];
6609 bitidx += end_bitidx;
6610 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6614 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6615 * @page: The page within the block of interest
6616 * @flags: The flags to set
6617 * @pfn: The target page frame number
6618 * @end_bitidx: The last bit of interest
6619 * @mask: mask of bits that the caller is interested in
6621 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6623 unsigned long end_bitidx,
6627 unsigned long *bitmap;
6628 unsigned long bitidx, word_bitidx;
6629 unsigned long old_word, word;
6631 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6633 zone = page_zone(page);
6634 bitmap = get_pageblock_bitmap(zone, pfn);
6635 bitidx = pfn_to_bitidx(zone, pfn);
6636 word_bitidx = bitidx / BITS_PER_LONG;
6637 bitidx &= (BITS_PER_LONG-1);
6639 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6641 bitidx += end_bitidx;
6642 mask <<= (BITS_PER_LONG - bitidx - 1);
6643 flags <<= (BITS_PER_LONG - bitidx - 1);
6645 word = READ_ONCE(bitmap[word_bitidx]);
6647 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6648 if (word == old_word)
6655 * This function checks whether pageblock includes unmovable pages or not.
6656 * If @count is not zero, it is okay to include less @count unmovable pages
6658 * PageLRU check without isolation or lru_lock could race so that
6659 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6660 * expect this function should be exact.
6662 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6663 bool skip_hwpoisoned_pages)
6665 unsigned long pfn, iter, found;
6669 * For avoiding noise data, lru_add_drain_all() should be called
6670 * If ZONE_MOVABLE, the zone never contains unmovable pages
6672 if (zone_idx(zone) == ZONE_MOVABLE)
6674 mt = get_pageblock_migratetype(page);
6675 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6678 pfn = page_to_pfn(page);
6679 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6680 unsigned long check = pfn + iter;
6682 if (!pfn_valid_within(check))
6685 page = pfn_to_page(check);
6688 * Hugepages are not in LRU lists, but they're movable.
6689 * We need not scan over tail pages bacause we don't
6690 * handle each tail page individually in migration.
6692 if (PageHuge(page)) {
6693 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6698 * We can't use page_count without pin a page
6699 * because another CPU can free compound page.
6700 * This check already skips compound tails of THP
6701 * because their page->_count is zero at all time.
6703 if (!atomic_read(&page->_count)) {
6704 if (PageBuddy(page))
6705 iter += (1 << page_order(page)) - 1;
6710 * The HWPoisoned page may be not in buddy system, and
6711 * page_count() is not 0.
6713 if (skip_hwpoisoned_pages && PageHWPoison(page))
6719 * If there are RECLAIMABLE pages, we need to check
6720 * it. But now, memory offline itself doesn't call
6721 * shrink_node_slabs() and it still to be fixed.
6724 * If the page is not RAM, page_count()should be 0.
6725 * we don't need more check. This is an _used_ not-movable page.
6727 * The problematic thing here is PG_reserved pages. PG_reserved
6728 * is set to both of a memory hole page and a _used_ kernel
6737 bool is_pageblock_removable_nolock(struct page *page)
6743 * We have to be careful here because we are iterating over memory
6744 * sections which are not zone aware so we might end up outside of
6745 * the zone but still within the section.
6746 * We have to take care about the node as well. If the node is offline
6747 * its NODE_DATA will be NULL - see page_zone.
6749 if (!node_online(page_to_nid(page)))
6752 zone = page_zone(page);
6753 pfn = page_to_pfn(page);
6754 if (!zone_spans_pfn(zone, pfn))
6757 return !has_unmovable_pages(zone, page, 0, true);
6762 static unsigned long pfn_max_align_down(unsigned long pfn)
6764 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6765 pageblock_nr_pages) - 1);
6768 static unsigned long pfn_max_align_up(unsigned long pfn)
6770 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6771 pageblock_nr_pages));
6774 /* [start, end) must belong to a single zone. */
6775 static int __alloc_contig_migrate_range(struct compact_control *cc,
6776 unsigned long start, unsigned long end)
6778 /* This function is based on compact_zone() from compaction.c. */
6779 unsigned long nr_reclaimed;
6780 unsigned long pfn = start;
6781 unsigned int tries = 0;
6786 while (pfn < end || !list_empty(&cc->migratepages)) {
6787 if (fatal_signal_pending(current)) {
6792 if (list_empty(&cc->migratepages)) {
6793 cc->nr_migratepages = 0;
6794 pfn = isolate_migratepages_range(cc, pfn, end);
6800 } else if (++tries == 5) {
6801 ret = ret < 0 ? ret : -EBUSY;
6805 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6807 cc->nr_migratepages -= nr_reclaimed;
6809 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6810 NULL, 0, cc->mode, MR_CMA);
6813 putback_movable_pages(&cc->migratepages);
6820 * alloc_contig_range() -- tries to allocate given range of pages
6821 * @start: start PFN to allocate
6822 * @end: one-past-the-last PFN to allocate
6823 * @migratetype: migratetype of the underlaying pageblocks (either
6824 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6825 * in range must have the same migratetype and it must
6826 * be either of the two.
6828 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6829 * aligned, however it's the caller's responsibility to guarantee that
6830 * we are the only thread that changes migrate type of pageblocks the
6833 * The PFN range must belong to a single zone.
6835 * Returns zero on success or negative error code. On success all
6836 * pages which PFN is in [start, end) are allocated for the caller and
6837 * need to be freed with free_contig_range().
6839 int alloc_contig_range(unsigned long start, unsigned long end,
6840 unsigned migratetype)
6842 unsigned long outer_start, outer_end;
6845 struct compact_control cc = {
6846 .nr_migratepages = 0,
6848 .zone = page_zone(pfn_to_page(start)),
6849 .mode = MIGRATE_SYNC,
6850 .ignore_skip_hint = true,
6852 INIT_LIST_HEAD(&cc.migratepages);
6855 * What we do here is we mark all pageblocks in range as
6856 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6857 * have different sizes, and due to the way page allocator
6858 * work, we align the range to biggest of the two pages so
6859 * that page allocator won't try to merge buddies from
6860 * different pageblocks and change MIGRATE_ISOLATE to some
6861 * other migration type.
6863 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6864 * migrate the pages from an unaligned range (ie. pages that
6865 * we are interested in). This will put all the pages in
6866 * range back to page allocator as MIGRATE_ISOLATE.
6868 * When this is done, we take the pages in range from page
6869 * allocator removing them from the buddy system. This way
6870 * page allocator will never consider using them.
6872 * This lets us mark the pageblocks back as
6873 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6874 * aligned range but not in the unaligned, original range are
6875 * put back to page allocator so that buddy can use them.
6878 ret = start_isolate_page_range(pfn_max_align_down(start),
6879 pfn_max_align_up(end), migratetype,
6884 ret = __alloc_contig_migrate_range(&cc, start, end);
6889 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6890 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6891 * more, all pages in [start, end) are free in page allocator.
6892 * What we are going to do is to allocate all pages from
6893 * [start, end) (that is remove them from page allocator).
6895 * The only problem is that pages at the beginning and at the
6896 * end of interesting range may be not aligned with pages that
6897 * page allocator holds, ie. they can be part of higher order
6898 * pages. Because of this, we reserve the bigger range and
6899 * once this is done free the pages we are not interested in.
6901 * We don't have to hold zone->lock here because the pages are
6902 * isolated thus they won't get removed from buddy.
6905 lru_add_drain_all();
6906 drain_all_pages(cc.zone);
6909 outer_start = start;
6910 while (!PageBuddy(pfn_to_page(outer_start))) {
6911 if (++order >= MAX_ORDER) {
6915 outer_start &= ~0UL << order;
6918 /* Make sure the range is really isolated. */
6919 if (test_pages_isolated(outer_start, end, false)) {
6920 pr_info("%s: [%lx, %lx) PFNs busy\n",
6921 __func__, outer_start, end);
6926 /* Grab isolated pages from freelists. */
6927 outer_end = isolate_freepages_range(&cc, outer_start, end);
6933 /* Free head and tail (if any) */
6934 if (start != outer_start)
6935 free_contig_range(outer_start, start - outer_start);
6936 if (end != outer_end)
6937 free_contig_range(end, outer_end - end);
6940 undo_isolate_page_range(pfn_max_align_down(start),
6941 pfn_max_align_up(end), migratetype);
6945 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6947 unsigned int count = 0;
6949 for (; nr_pages--; pfn++) {
6950 struct page *page = pfn_to_page(pfn);
6952 count += page_count(page) != 1;
6955 WARN(count != 0, "%d pages are still in use!\n", count);
6959 #ifdef CONFIG_MEMORY_HOTPLUG
6961 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6962 * page high values need to be recalulated.
6964 void __meminit zone_pcp_update(struct zone *zone)
6967 mutex_lock(&pcp_batch_high_lock);
6968 for_each_possible_cpu(cpu)
6969 pageset_set_high_and_batch(zone,
6970 per_cpu_ptr(zone->pageset, cpu));
6971 mutex_unlock(&pcp_batch_high_lock);
6975 void zone_pcp_reset(struct zone *zone)
6977 unsigned long flags;
6979 struct per_cpu_pageset *pset;
6981 /* avoid races with drain_pages() */
6982 local_irq_save(flags);
6983 if (zone->pageset != &boot_pageset) {
6984 for_each_online_cpu(cpu) {
6985 pset = per_cpu_ptr(zone->pageset, cpu);
6986 drain_zonestat(zone, pset);
6988 free_percpu(zone->pageset);
6989 zone->pageset = &boot_pageset;
6991 local_irq_restore(flags);
6994 #ifdef CONFIG_MEMORY_HOTREMOVE
6996 * All pages in the range must be isolated before calling this.
6999 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7003 unsigned int order, i;
7005 unsigned long flags;
7006 /* find the first valid pfn */
7007 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7012 zone = page_zone(pfn_to_page(pfn));
7013 spin_lock_irqsave(&zone->lock, flags);
7015 while (pfn < end_pfn) {
7016 if (!pfn_valid(pfn)) {
7020 page = pfn_to_page(pfn);
7022 * The HWPoisoned page may be not in buddy system, and
7023 * page_count() is not 0.
7025 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7027 SetPageReserved(page);
7031 BUG_ON(page_count(page));
7032 BUG_ON(!PageBuddy(page));
7033 order = page_order(page);
7034 #ifdef CONFIG_DEBUG_VM
7035 printk(KERN_INFO "remove from free list %lx %d %lx\n",
7036 pfn, 1 << order, end_pfn);
7038 list_del(&page->lru);
7039 rmv_page_order(page);
7040 zone->free_area[order].nr_free--;
7041 for (i = 0; i < (1 << order); i++)
7042 SetPageReserved((page+i));
7043 pfn += (1 << order);
7045 spin_unlock_irqrestore(&zone->lock, flags);
7049 #ifdef CONFIG_MEMORY_FAILURE
7050 bool is_free_buddy_page(struct page *page)
7052 struct zone *zone = page_zone(page);
7053 unsigned long pfn = page_to_pfn(page);
7054 unsigned long flags;
7057 spin_lock_irqsave(&zone->lock, flags);
7058 for (order = 0; order < MAX_ORDER; order++) {
7059 struct page *page_head = page - (pfn & ((1 << order) - 1));
7061 if (PageBuddy(page_head) && page_order(page_head) >= order)
7064 spin_unlock_irqrestore(&zone->lock, flags);
7066 return order < MAX_ORDER;