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>
65 #include <asm/sections.h>
66 #include <asm/tlbflush.h>
67 #include <asm/div64.h>
70 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
71 static DEFINE_MUTEX(pcp_batch_high_lock);
72 #define MIN_PERCPU_PAGELIST_FRACTION (8)
74 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
75 DEFINE_PER_CPU(int, numa_node);
76 EXPORT_PER_CPU_SYMBOL(numa_node);
79 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
81 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
82 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
83 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
84 * defined in <linux/topology.h>.
86 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
87 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
88 int _node_numa_mem_[MAX_NUMNODES];
92 * Array of node states.
94 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
95 [N_POSSIBLE] = NODE_MASK_ALL,
96 [N_ONLINE] = { { [0] = 1UL } },
98 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
100 [N_HIGH_MEMORY] = { { [0] = 1UL } },
102 #ifdef CONFIG_MOVABLE_NODE
103 [N_MEMORY] = { { [0] = 1UL } },
105 [N_CPU] = { { [0] = 1UL } },
108 EXPORT_SYMBOL(node_states);
110 /* Protect totalram_pages and zone->managed_pages */
111 static DEFINE_SPINLOCK(managed_page_count_lock);
113 unsigned long totalram_pages __read_mostly;
114 unsigned long totalreserve_pages __read_mostly;
115 unsigned long totalcma_pages __read_mostly;
117 * When calculating the number of globally allowed dirty pages, there
118 * is a certain number of per-zone reserves that should not be
119 * considered dirtyable memory. This is the sum of those reserves
120 * over all existing zones that contribute dirtyable memory.
122 unsigned long dirty_balance_reserve __read_mostly;
124 int percpu_pagelist_fraction;
125 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
127 #ifdef CONFIG_PM_SLEEP
129 * The following functions are used by the suspend/hibernate code to temporarily
130 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
131 * while devices are suspended. To avoid races with the suspend/hibernate code,
132 * they should always be called with pm_mutex held (gfp_allowed_mask also should
133 * only be modified with pm_mutex held, unless the suspend/hibernate code is
134 * guaranteed not to run in parallel with that modification).
137 static gfp_t saved_gfp_mask;
139 void pm_restore_gfp_mask(void)
141 WARN_ON(!mutex_is_locked(&pm_mutex));
142 if (saved_gfp_mask) {
143 gfp_allowed_mask = saved_gfp_mask;
148 void pm_restrict_gfp_mask(void)
150 WARN_ON(!mutex_is_locked(&pm_mutex));
151 WARN_ON(saved_gfp_mask);
152 saved_gfp_mask = gfp_allowed_mask;
153 gfp_allowed_mask &= ~GFP_IOFS;
156 bool pm_suspended_storage(void)
158 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
162 #endif /* CONFIG_PM_SLEEP */
164 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
165 int pageblock_order __read_mostly;
168 static void __free_pages_ok(struct page *page, unsigned int order);
171 * results with 256, 32 in the lowmem_reserve sysctl:
172 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
173 * 1G machine -> (16M dma, 784M normal, 224M high)
174 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
175 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
176 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
178 * TBD: should special case ZONE_DMA32 machines here - in those we normally
179 * don't need any ZONE_NORMAL reservation
181 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
182 #ifdef CONFIG_ZONE_DMA
185 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 EXPORT_SYMBOL(totalram_pages);
196 static char * const zone_names[MAX_NR_ZONES] = {
197 #ifdef CONFIG_ZONE_DMA
200 #ifdef CONFIG_ZONE_DMA32
204 #ifdef CONFIG_HIGHMEM
210 int min_free_kbytes = 1024;
211 int user_min_free_kbytes = -1;
213 static unsigned long __meminitdata nr_kernel_pages;
214 static unsigned long __meminitdata nr_all_pages;
215 static unsigned long __meminitdata dma_reserve;
217 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
218 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
219 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
220 static unsigned long __initdata required_kernelcore;
221 static unsigned long __initdata required_movablecore;
222 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
224 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
226 EXPORT_SYMBOL(movable_zone);
227 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
230 int nr_node_ids __read_mostly = MAX_NUMNODES;
231 int nr_online_nodes __read_mostly = 1;
232 EXPORT_SYMBOL(nr_node_ids);
233 EXPORT_SYMBOL(nr_online_nodes);
236 int page_group_by_mobility_disabled __read_mostly;
238 void set_pageblock_migratetype(struct page *page, int migratetype)
240 if (unlikely(page_group_by_mobility_disabled &&
241 migratetype < MIGRATE_PCPTYPES))
242 migratetype = MIGRATE_UNMOVABLE;
244 set_pageblock_flags_group(page, (unsigned long)migratetype,
245 PB_migrate, PB_migrate_end);
248 #ifdef CONFIG_DEBUG_VM
249 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
253 unsigned long pfn = page_to_pfn(page);
254 unsigned long sp, start_pfn;
257 seq = zone_span_seqbegin(zone);
258 start_pfn = zone->zone_start_pfn;
259 sp = zone->spanned_pages;
260 if (!zone_spans_pfn(zone, pfn))
262 } while (zone_span_seqretry(zone, seq));
265 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
266 pfn, zone_to_nid(zone), zone->name,
267 start_pfn, start_pfn + sp);
272 static int page_is_consistent(struct zone *zone, struct page *page)
274 if (!pfn_valid_within(page_to_pfn(page)))
276 if (zone != page_zone(page))
282 * Temporary debugging check for pages not lying within a given zone.
284 static int bad_range(struct zone *zone, struct page *page)
286 if (page_outside_zone_boundaries(zone, page))
288 if (!page_is_consistent(zone, page))
294 static inline int bad_range(struct zone *zone, struct page *page)
300 static void bad_page(struct page *page, const char *reason,
301 unsigned long bad_flags)
303 static unsigned long resume;
304 static unsigned long nr_shown;
305 static unsigned long nr_unshown;
307 /* Don't complain about poisoned pages */
308 if (PageHWPoison(page)) {
309 page_mapcount_reset(page); /* remove PageBuddy */
314 * Allow a burst of 60 reports, then keep quiet for that minute;
315 * or allow a steady drip of one report per second.
317 if (nr_shown == 60) {
318 if (time_before(jiffies, resume)) {
324 "BUG: Bad page state: %lu messages suppressed\n",
331 resume = jiffies + 60 * HZ;
333 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
334 current->comm, page_to_pfn(page));
335 dump_page_badflags(page, reason, bad_flags);
340 /* Leave bad fields for debug, except PageBuddy could make trouble */
341 page_mapcount_reset(page); /* remove PageBuddy */
342 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
346 * Higher-order pages are called "compound pages". They are structured thusly:
348 * The first PAGE_SIZE page is called the "head page".
350 * The remaining PAGE_SIZE pages are called "tail pages".
352 * All pages have PG_compound set. All tail pages have their ->first_page
353 * pointing at the head page.
355 * The first tail page's ->lru.next holds the address of the compound page's
356 * put_page() function. Its ->lru.prev holds the order of allocation.
357 * This usage means that zero-order pages may not be compound.
360 static void free_compound_page(struct page *page)
362 __free_pages_ok(page, compound_order(page));
365 void prep_compound_page(struct page *page, unsigned long order)
368 int nr_pages = 1 << order;
370 set_compound_page_dtor(page, free_compound_page);
371 set_compound_order(page, order);
373 for (i = 1; i < nr_pages; i++) {
374 struct page *p = page + i;
375 set_page_count(p, 0);
376 p->first_page = page;
377 /* Make sure p->first_page is always valid for PageTail() */
383 #ifdef CONFIG_DEBUG_PAGEALLOC
384 unsigned int _debug_guardpage_minorder;
385 bool _debug_pagealloc_enabled __read_mostly;
386 bool _debug_guardpage_enabled __read_mostly;
388 static int __init early_debug_pagealloc(char *buf)
393 if (strcmp(buf, "on") == 0)
394 _debug_pagealloc_enabled = true;
398 early_param("debug_pagealloc", early_debug_pagealloc);
400 static bool need_debug_guardpage(void)
402 /* If we don't use debug_pagealloc, we don't need guard page */
403 if (!debug_pagealloc_enabled())
409 static void init_debug_guardpage(void)
411 if (!debug_pagealloc_enabled())
414 _debug_guardpage_enabled = true;
417 struct page_ext_operations debug_guardpage_ops = {
418 .need = need_debug_guardpage,
419 .init = init_debug_guardpage,
422 static int __init debug_guardpage_minorder_setup(char *buf)
426 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
427 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
430 _debug_guardpage_minorder = res;
431 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
434 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
436 static inline void set_page_guard(struct zone *zone, struct page *page,
437 unsigned int order, int migratetype)
439 struct page_ext *page_ext;
441 if (!debug_guardpage_enabled())
444 page_ext = lookup_page_ext(page);
445 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
447 INIT_LIST_HEAD(&page->lru);
448 set_page_private(page, order);
449 /* Guard pages are not available for any usage */
450 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
453 static inline void clear_page_guard(struct zone *zone, struct page *page,
454 unsigned int order, int migratetype)
456 struct page_ext *page_ext;
458 if (!debug_guardpage_enabled())
461 page_ext = lookup_page_ext(page);
462 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
464 set_page_private(page, 0);
465 if (!is_migrate_isolate(migratetype))
466 __mod_zone_freepage_state(zone, (1 << order), migratetype);
469 struct page_ext_operations debug_guardpage_ops = { NULL, };
470 static inline void set_page_guard(struct zone *zone, struct page *page,
471 unsigned int order, int migratetype) {}
472 static inline void clear_page_guard(struct zone *zone, struct page *page,
473 unsigned int order, int migratetype) {}
476 static inline void set_page_order(struct page *page, unsigned int order)
478 set_page_private(page, order);
479 __SetPageBuddy(page);
482 static inline void rmv_page_order(struct page *page)
484 __ClearPageBuddy(page);
485 set_page_private(page, 0);
489 * This function checks whether a page is free && is the buddy
490 * we can do coalesce a page and its buddy if
491 * (a) the buddy is not in a hole &&
492 * (b) the buddy is in the buddy system &&
493 * (c) a page and its buddy have the same order &&
494 * (d) a page and its buddy are in the same zone.
496 * For recording whether a page is in the buddy system, we set ->_mapcount
497 * PAGE_BUDDY_MAPCOUNT_VALUE.
498 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
499 * serialized by zone->lock.
501 * For recording page's order, we use page_private(page).
503 static inline int page_is_buddy(struct page *page, struct page *buddy,
506 if (!pfn_valid_within(page_to_pfn(buddy)))
509 if (page_is_guard(buddy) && page_order(buddy) == order) {
510 if (page_zone_id(page) != page_zone_id(buddy))
513 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
518 if (PageBuddy(buddy) && page_order(buddy) == order) {
520 * zone check is done late to avoid uselessly
521 * calculating zone/node ids for pages that could
524 if (page_zone_id(page) != page_zone_id(buddy))
527 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
535 * Freeing function for a buddy system allocator.
537 * The concept of a buddy system is to maintain direct-mapped table
538 * (containing bit values) for memory blocks of various "orders".
539 * The bottom level table contains the map for the smallest allocatable
540 * units of memory (here, pages), and each level above it describes
541 * pairs of units from the levels below, hence, "buddies".
542 * At a high level, all that happens here is marking the table entry
543 * at the bottom level available, and propagating the changes upward
544 * as necessary, plus some accounting needed to play nicely with other
545 * parts of the VM system.
546 * At each level, we keep a list of pages, which are heads of continuous
547 * free pages of length of (1 << order) and marked with _mapcount
548 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
550 * So when we are allocating or freeing one, we can derive the state of the
551 * other. That is, if we allocate a small block, and both were
552 * free, the remainder of the region must be split into blocks.
553 * If a block is freed, and its buddy is also free, then this
554 * triggers coalescing into a block of larger size.
559 static inline void __free_one_page(struct page *page,
561 struct zone *zone, unsigned int order,
564 unsigned long page_idx;
565 unsigned long combined_idx;
566 unsigned long uninitialized_var(buddy_idx);
568 int max_order = MAX_ORDER;
570 VM_BUG_ON(!zone_is_initialized(zone));
571 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
573 VM_BUG_ON(migratetype == -1);
574 if (is_migrate_isolate(migratetype)) {
576 * We restrict max order of merging to prevent merge
577 * between freepages on isolate pageblock and normal
578 * pageblock. Without this, pageblock isolation
579 * could cause incorrect freepage accounting.
581 max_order = min(MAX_ORDER, pageblock_order + 1);
583 __mod_zone_freepage_state(zone, 1 << order, migratetype);
586 page_idx = pfn & ((1 << max_order) - 1);
588 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
589 VM_BUG_ON_PAGE(bad_range(zone, page), page);
591 while (order < max_order - 1) {
592 buddy_idx = __find_buddy_index(page_idx, order);
593 buddy = page + (buddy_idx - page_idx);
594 if (!page_is_buddy(page, buddy, order))
597 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
598 * merge with it and move up one order.
600 if (page_is_guard(buddy)) {
601 clear_page_guard(zone, buddy, order, migratetype);
603 list_del(&buddy->lru);
604 zone->free_area[order].nr_free--;
605 rmv_page_order(buddy);
607 combined_idx = buddy_idx & page_idx;
608 page = page + (combined_idx - page_idx);
609 page_idx = combined_idx;
612 set_page_order(page, order);
615 * If this is not the largest possible page, check if the buddy
616 * of the next-highest order is free. If it is, it's possible
617 * that pages are being freed that will coalesce soon. In case,
618 * that is happening, add the free page to the tail of the list
619 * so it's less likely to be used soon and more likely to be merged
620 * as a higher order page
622 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
623 struct page *higher_page, *higher_buddy;
624 combined_idx = buddy_idx & page_idx;
625 higher_page = page + (combined_idx - page_idx);
626 buddy_idx = __find_buddy_index(combined_idx, order + 1);
627 higher_buddy = higher_page + (buddy_idx - combined_idx);
628 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
629 list_add_tail(&page->lru,
630 &zone->free_area[order].free_list[migratetype]);
635 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
637 zone->free_area[order].nr_free++;
640 static inline int free_pages_check(struct page *page)
642 const char *bad_reason = NULL;
643 unsigned long bad_flags = 0;
645 if (unlikely(page_mapcount(page)))
646 bad_reason = "nonzero mapcount";
647 if (unlikely(page->mapping != NULL))
648 bad_reason = "non-NULL mapping";
649 if (unlikely(atomic_read(&page->_count) != 0))
650 bad_reason = "nonzero _count";
651 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
652 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
653 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
656 if (unlikely(page->mem_cgroup))
657 bad_reason = "page still charged to cgroup";
659 if (unlikely(bad_reason)) {
660 bad_page(page, bad_reason, bad_flags);
663 page_cpupid_reset_last(page);
664 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
665 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
670 * Frees a number of pages from the PCP lists
671 * Assumes all pages on list are in same zone, and of same order.
672 * count is the number of pages to free.
674 * If the zone was previously in an "all pages pinned" state then look to
675 * see if this freeing clears that state.
677 * And clear the zone's pages_scanned counter, to hold off the "all pages are
678 * pinned" detection logic.
680 static void free_pcppages_bulk(struct zone *zone, int count,
681 struct per_cpu_pages *pcp)
686 unsigned long nr_scanned;
688 spin_lock(&zone->lock);
689 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
691 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
695 struct list_head *list;
698 * Remove pages from lists in a round-robin fashion. A
699 * batch_free count is maintained that is incremented when an
700 * empty list is encountered. This is so more pages are freed
701 * off fuller lists instead of spinning excessively around empty
706 if (++migratetype == MIGRATE_PCPTYPES)
708 list = &pcp->lists[migratetype];
709 } while (list_empty(list));
711 /* This is the only non-empty list. Free them all. */
712 if (batch_free == MIGRATE_PCPTYPES)
713 batch_free = to_free;
716 int mt; /* migratetype of the to-be-freed page */
718 page = list_entry(list->prev, struct page, lru);
719 /* must delete as __free_one_page list manipulates */
720 list_del(&page->lru);
721 mt = get_freepage_migratetype(page);
722 if (unlikely(has_isolate_pageblock(zone)))
723 mt = get_pageblock_migratetype(page);
725 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
726 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
727 trace_mm_page_pcpu_drain(page, 0, mt);
728 } while (--to_free && --batch_free && !list_empty(list));
730 spin_unlock(&zone->lock);
733 static void free_one_page(struct zone *zone,
734 struct page *page, unsigned long pfn,
738 unsigned long nr_scanned;
739 spin_lock(&zone->lock);
740 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
742 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
744 if (unlikely(has_isolate_pageblock(zone) ||
745 is_migrate_isolate(migratetype))) {
746 migratetype = get_pfnblock_migratetype(page, pfn);
748 __free_one_page(page, pfn, zone, order, migratetype);
749 spin_unlock(&zone->lock);
752 static int free_tail_pages_check(struct page *head_page, struct page *page)
754 if (!IS_ENABLED(CONFIG_DEBUG_VM))
756 if (unlikely(!PageTail(page))) {
757 bad_page(page, "PageTail not set", 0);
760 if (unlikely(page->first_page != head_page)) {
761 bad_page(page, "first_page not consistent", 0);
767 static bool free_pages_prepare(struct page *page, unsigned int order)
769 bool compound = PageCompound(page);
772 VM_BUG_ON_PAGE(PageTail(page), page);
773 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
775 trace_mm_page_free(page, order);
776 kmemcheck_free_shadow(page, order);
777 kasan_free_pages(page, order);
780 page->mapping = NULL;
781 bad += free_pages_check(page);
782 for (i = 1; i < (1 << order); i++) {
784 bad += free_tail_pages_check(page, page + i);
785 bad += free_pages_check(page + i);
790 reset_page_owner(page, order);
792 if (!PageHighMem(page)) {
793 debug_check_no_locks_freed(page_address(page),
795 debug_check_no_obj_freed(page_address(page),
798 arch_free_page(page, order);
799 kernel_map_pages(page, 1 << order, 0);
804 static void __free_pages_ok(struct page *page, unsigned int order)
808 unsigned long pfn = page_to_pfn(page);
810 if (!free_pages_prepare(page, order))
813 migratetype = get_pfnblock_migratetype(page, pfn);
814 local_irq_save(flags);
815 __count_vm_events(PGFREE, 1 << order);
816 set_freepage_migratetype(page, migratetype);
817 free_one_page(page_zone(page), page, pfn, order, migratetype);
818 local_irq_restore(flags);
821 void __init __free_pages_bootmem(struct page *page, unsigned int order)
823 unsigned int nr_pages = 1 << order;
824 struct page *p = page;
828 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
830 __ClearPageReserved(p);
831 set_page_count(p, 0);
833 __ClearPageReserved(p);
834 set_page_count(p, 0);
836 page_zone(page)->managed_pages += nr_pages;
837 set_page_refcounted(page);
838 __free_pages(page, order);
842 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
843 void __init init_cma_reserved_pageblock(struct page *page)
845 unsigned i = pageblock_nr_pages;
846 struct page *p = page;
849 __ClearPageReserved(p);
850 set_page_count(p, 0);
853 set_pageblock_migratetype(page, MIGRATE_CMA);
855 if (pageblock_order >= MAX_ORDER) {
856 i = pageblock_nr_pages;
859 set_page_refcounted(p);
860 __free_pages(p, MAX_ORDER - 1);
861 p += MAX_ORDER_NR_PAGES;
862 } while (i -= MAX_ORDER_NR_PAGES);
864 set_page_refcounted(page);
865 __free_pages(page, pageblock_order);
868 adjust_managed_page_count(page, pageblock_nr_pages);
873 * The order of subdivision here is critical for the IO subsystem.
874 * Please do not alter this order without good reasons and regression
875 * testing. Specifically, as large blocks of memory are subdivided,
876 * the order in which smaller blocks are delivered depends on the order
877 * they're subdivided in this function. This is the primary factor
878 * influencing the order in which pages are delivered to the IO
879 * subsystem according to empirical testing, and this is also justified
880 * by considering the behavior of a buddy system containing a single
881 * large block of memory acted on by a series of small allocations.
882 * This behavior is a critical factor in sglist merging's success.
886 static inline void expand(struct zone *zone, struct page *page,
887 int low, int high, struct free_area *area,
890 unsigned long size = 1 << high;
896 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
898 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
899 debug_guardpage_enabled() &&
900 high < debug_guardpage_minorder()) {
902 * Mark as guard pages (or page), that will allow to
903 * merge back to allocator when buddy will be freed.
904 * Corresponding page table entries will not be touched,
905 * pages will stay not present in virtual address space
907 set_page_guard(zone, &page[size], high, migratetype);
910 list_add(&page[size].lru, &area->free_list[migratetype]);
912 set_page_order(&page[size], high);
917 * This page is about to be returned from the page allocator
919 static inline int check_new_page(struct page *page)
921 const char *bad_reason = NULL;
922 unsigned long bad_flags = 0;
924 if (unlikely(page_mapcount(page)))
925 bad_reason = "nonzero mapcount";
926 if (unlikely(page->mapping != NULL))
927 bad_reason = "non-NULL mapping";
928 if (unlikely(atomic_read(&page->_count) != 0))
929 bad_reason = "nonzero _count";
930 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
931 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
932 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
935 if (unlikely(page->mem_cgroup))
936 bad_reason = "page still charged to cgroup";
938 if (unlikely(bad_reason)) {
939 bad_page(page, bad_reason, bad_flags);
945 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
950 for (i = 0; i < (1 << order); i++) {
951 struct page *p = page + i;
952 if (unlikely(check_new_page(p)))
956 set_page_private(page, 0);
957 set_page_refcounted(page);
959 arch_alloc_page(page, order);
960 kernel_map_pages(page, 1 << order, 1);
961 kasan_alloc_pages(page, order);
963 if (gfp_flags & __GFP_ZERO)
964 for (i = 0; i < (1 << order); i++)
965 clear_highpage(page + i);
967 if (order && (gfp_flags & __GFP_COMP))
968 prep_compound_page(page, order);
970 set_page_owner(page, order, gfp_flags);
973 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was necessary to
974 * allocate the page. The expectation is that the caller is taking
975 * steps that will free more memory. The caller should avoid the page
976 * being used for !PFMEMALLOC purposes.
978 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
984 * Go through the free lists for the given migratetype and remove
985 * the smallest available page from the freelists
988 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
991 unsigned int current_order;
992 struct free_area *area;
995 /* Find a page of the appropriate size in the preferred list */
996 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
997 area = &(zone->free_area[current_order]);
998 if (list_empty(&area->free_list[migratetype]))
1001 page = list_entry(area->free_list[migratetype].next,
1003 list_del(&page->lru);
1004 rmv_page_order(page);
1006 expand(zone, page, order, current_order, area, migratetype);
1007 set_freepage_migratetype(page, migratetype);
1016 * This array describes the order lists are fallen back to when
1017 * the free lists for the desirable migrate type are depleted
1019 static int fallbacks[MIGRATE_TYPES][4] = {
1020 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
1021 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
1022 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
1024 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
1026 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
1027 #ifdef CONFIG_MEMORY_ISOLATION
1028 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
1033 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1036 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1039 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1040 unsigned int order) { return NULL; }
1044 * Move the free pages in a range to the free lists of the requested type.
1045 * Note that start_page and end_pages are not aligned on a pageblock
1046 * boundary. If alignment is required, use move_freepages_block()
1048 int move_freepages(struct zone *zone,
1049 struct page *start_page, struct page *end_page,
1053 unsigned long order;
1054 int pages_moved = 0;
1056 #ifndef CONFIG_HOLES_IN_ZONE
1058 * page_zone is not safe to call in this context when
1059 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1060 * anyway as we check zone boundaries in move_freepages_block().
1061 * Remove at a later date when no bug reports exist related to
1062 * grouping pages by mobility
1064 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1067 for (page = start_page; page <= end_page;) {
1068 /* Make sure we are not inadvertently changing nodes */
1069 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1071 if (!pfn_valid_within(page_to_pfn(page))) {
1076 if (!PageBuddy(page)) {
1081 order = page_order(page);
1082 list_move(&page->lru,
1083 &zone->free_area[order].free_list[migratetype]);
1084 set_freepage_migratetype(page, migratetype);
1086 pages_moved += 1 << order;
1092 int move_freepages_block(struct zone *zone, struct page *page,
1095 unsigned long start_pfn, end_pfn;
1096 struct page *start_page, *end_page;
1098 start_pfn = page_to_pfn(page);
1099 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1100 start_page = pfn_to_page(start_pfn);
1101 end_page = start_page + pageblock_nr_pages - 1;
1102 end_pfn = start_pfn + pageblock_nr_pages - 1;
1104 /* Do not cross zone boundaries */
1105 if (!zone_spans_pfn(zone, start_pfn))
1107 if (!zone_spans_pfn(zone, end_pfn))
1110 return move_freepages(zone, start_page, end_page, migratetype);
1113 static void change_pageblock_range(struct page *pageblock_page,
1114 int start_order, int migratetype)
1116 int nr_pageblocks = 1 << (start_order - pageblock_order);
1118 while (nr_pageblocks--) {
1119 set_pageblock_migratetype(pageblock_page, migratetype);
1120 pageblock_page += pageblock_nr_pages;
1125 * When we are falling back to another migratetype during allocation, try to
1126 * steal extra free pages from the same pageblocks to satisfy further
1127 * allocations, instead of polluting multiple pageblocks.
1129 * If we are stealing a relatively large buddy page, it is likely there will
1130 * be more free pages in the pageblock, so try to steal them all. For
1131 * reclaimable and unmovable allocations, we steal regardless of page size,
1132 * as fragmentation caused by those allocations polluting movable pageblocks
1133 * is worse than movable allocations stealing from unmovable and reclaimable
1136 static bool can_steal_fallback(unsigned int order, int start_mt)
1139 * Leaving this order check is intended, although there is
1140 * relaxed order check in next check. The reason is that
1141 * we can actually steal whole pageblock if this condition met,
1142 * but, below check doesn't guarantee it and that is just heuristic
1143 * so could be changed anytime.
1145 if (order >= pageblock_order)
1148 if (order >= pageblock_order / 2 ||
1149 start_mt == MIGRATE_RECLAIMABLE ||
1150 start_mt == MIGRATE_UNMOVABLE ||
1151 page_group_by_mobility_disabled)
1158 * This function implements actual steal behaviour. If order is large enough,
1159 * we can steal whole pageblock. If not, we first move freepages in this
1160 * pageblock and check whether half of pages are moved or not. If half of
1161 * pages are moved, we can change migratetype of pageblock and permanently
1162 * use it's pages as requested migratetype in the future.
1164 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1167 int current_order = page_order(page);
1170 /* Take ownership for orders >= pageblock_order */
1171 if (current_order >= pageblock_order) {
1172 change_pageblock_range(page, current_order, start_type);
1176 pages = move_freepages_block(zone, page, start_type);
1178 /* Claim the whole block if over half of it is free */
1179 if (pages >= (1 << (pageblock_order-1)) ||
1180 page_group_by_mobility_disabled)
1181 set_pageblock_migratetype(page, start_type);
1185 * Check whether there is a suitable fallback freepage with requested order.
1186 * If only_stealable is true, this function returns fallback_mt only if
1187 * we can steal other freepages all together. This would help to reduce
1188 * fragmentation due to mixed migratetype pages in one pageblock.
1190 int find_suitable_fallback(struct free_area *area, unsigned int order,
1191 int migratetype, bool only_stealable, bool *can_steal)
1196 if (area->nr_free == 0)
1201 fallback_mt = fallbacks[migratetype][i];
1202 if (fallback_mt == MIGRATE_RESERVE)
1205 if (list_empty(&area->free_list[fallback_mt]))
1208 if (can_steal_fallback(order, migratetype))
1211 if (!only_stealable)
1221 /* Remove an element from the buddy allocator from the fallback list */
1222 static inline struct page *
1223 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1225 struct free_area *area;
1226 unsigned int current_order;
1231 /* Find the largest possible block of pages in the other list */
1232 for (current_order = MAX_ORDER-1;
1233 current_order >= order && current_order <= MAX_ORDER-1;
1235 area = &(zone->free_area[current_order]);
1236 fallback_mt = find_suitable_fallback(area, current_order,
1237 start_migratetype, false, &can_steal);
1238 if (fallback_mt == -1)
1241 page = list_entry(area->free_list[fallback_mt].next,
1244 steal_suitable_fallback(zone, page, start_migratetype);
1246 /* Remove the page from the freelists */
1248 list_del(&page->lru);
1249 rmv_page_order(page);
1251 expand(zone, page, order, current_order, area,
1254 * The freepage_migratetype may differ from pageblock's
1255 * migratetype depending on the decisions in
1256 * try_to_steal_freepages(). This is OK as long as it
1257 * does not differ for MIGRATE_CMA pageblocks. For CMA
1258 * we need to make sure unallocated pages flushed from
1259 * pcp lists are returned to the correct freelist.
1261 set_freepage_migratetype(page, start_migratetype);
1263 trace_mm_page_alloc_extfrag(page, order, current_order,
1264 start_migratetype, fallback_mt);
1273 * Do the hard work of removing an element from the buddy allocator.
1274 * Call me with the zone->lock already held.
1276 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1282 page = __rmqueue_smallest(zone, order, migratetype);
1284 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1285 if (migratetype == MIGRATE_MOVABLE)
1286 page = __rmqueue_cma_fallback(zone, order);
1289 page = __rmqueue_fallback(zone, order, migratetype);
1292 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1293 * is used because __rmqueue_smallest is an inline function
1294 * and we want just one call site
1297 migratetype = MIGRATE_RESERVE;
1302 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1307 * Obtain a specified number of elements from the buddy allocator, all under
1308 * a single hold of the lock, for efficiency. Add them to the supplied list.
1309 * Returns the number of new pages which were placed at *list.
1311 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1312 unsigned long count, struct list_head *list,
1313 int migratetype, bool cold)
1317 spin_lock(&zone->lock);
1318 for (i = 0; i < count; ++i) {
1319 struct page *page = __rmqueue(zone, order, migratetype);
1320 if (unlikely(page == NULL))
1324 * Split buddy pages returned by expand() are received here
1325 * in physical page order. The page is added to the callers and
1326 * list and the list head then moves forward. From the callers
1327 * perspective, the linked list is ordered by page number in
1328 * some conditions. This is useful for IO devices that can
1329 * merge IO requests if the physical pages are ordered
1333 list_add(&page->lru, list);
1335 list_add_tail(&page->lru, list);
1337 if (is_migrate_cma(get_freepage_migratetype(page)))
1338 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1341 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1342 spin_unlock(&zone->lock);
1348 * Called from the vmstat counter updater to drain pagesets of this
1349 * currently executing processor on remote nodes after they have
1352 * Note that this function must be called with the thread pinned to
1353 * a single processor.
1355 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1357 unsigned long flags;
1358 int to_drain, batch;
1360 local_irq_save(flags);
1361 batch = READ_ONCE(pcp->batch);
1362 to_drain = min(pcp->count, batch);
1364 free_pcppages_bulk(zone, to_drain, pcp);
1365 pcp->count -= to_drain;
1367 local_irq_restore(flags);
1372 * Drain pcplists of the indicated processor and zone.
1374 * The processor must either be the current processor and the
1375 * thread pinned to the current processor or a processor that
1378 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
1380 unsigned long flags;
1381 struct per_cpu_pageset *pset;
1382 struct per_cpu_pages *pcp;
1384 local_irq_save(flags);
1385 pset = per_cpu_ptr(zone->pageset, cpu);
1389 free_pcppages_bulk(zone, pcp->count, pcp);
1392 local_irq_restore(flags);
1396 * Drain pcplists of all zones on the indicated processor.
1398 * The processor must either be the current processor and the
1399 * thread pinned to the current processor or a processor that
1402 static void drain_pages(unsigned int cpu)
1406 for_each_populated_zone(zone) {
1407 drain_pages_zone(cpu, zone);
1412 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1414 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1415 * the single zone's pages.
1417 void drain_local_pages(struct zone *zone)
1419 int cpu = smp_processor_id();
1422 drain_pages_zone(cpu, zone);
1428 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1430 * When zone parameter is non-NULL, spill just the single zone's pages.
1432 * Note that this code is protected against sending an IPI to an offline
1433 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1434 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1435 * nothing keeps CPUs from showing up after we populated the cpumask and
1436 * before the call to on_each_cpu_mask().
1438 void drain_all_pages(struct zone *zone)
1443 * Allocate in the BSS so we wont require allocation in
1444 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1446 static cpumask_t cpus_with_pcps;
1449 * We don't care about racing with CPU hotplug event
1450 * as offline notification will cause the notified
1451 * cpu to drain that CPU pcps and on_each_cpu_mask
1452 * disables preemption as part of its processing
1454 for_each_online_cpu(cpu) {
1455 struct per_cpu_pageset *pcp;
1457 bool has_pcps = false;
1460 pcp = per_cpu_ptr(zone->pageset, cpu);
1464 for_each_populated_zone(z) {
1465 pcp = per_cpu_ptr(z->pageset, cpu);
1466 if (pcp->pcp.count) {
1474 cpumask_set_cpu(cpu, &cpus_with_pcps);
1476 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1478 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
1482 #ifdef CONFIG_HIBERNATION
1484 void mark_free_pages(struct zone *zone)
1486 unsigned long pfn, max_zone_pfn;
1487 unsigned long flags;
1488 unsigned int order, t;
1489 struct list_head *curr;
1491 if (zone_is_empty(zone))
1494 spin_lock_irqsave(&zone->lock, flags);
1496 max_zone_pfn = zone_end_pfn(zone);
1497 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1498 if (pfn_valid(pfn)) {
1499 struct page *page = pfn_to_page(pfn);
1501 if (!swsusp_page_is_forbidden(page))
1502 swsusp_unset_page_free(page);
1505 for_each_migratetype_order(order, t) {
1506 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1509 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1510 for (i = 0; i < (1UL << order); i++)
1511 swsusp_set_page_free(pfn_to_page(pfn + i));
1514 spin_unlock_irqrestore(&zone->lock, flags);
1516 #endif /* CONFIG_PM */
1519 * Free a 0-order page
1520 * cold == true ? free a cold page : free a hot page
1522 void free_hot_cold_page(struct page *page, bool cold)
1524 struct zone *zone = page_zone(page);
1525 struct per_cpu_pages *pcp;
1526 unsigned long flags;
1527 unsigned long pfn = page_to_pfn(page);
1530 if (!free_pages_prepare(page, 0))
1533 migratetype = get_pfnblock_migratetype(page, pfn);
1534 set_freepage_migratetype(page, migratetype);
1535 local_irq_save(flags);
1536 __count_vm_event(PGFREE);
1539 * We only track unmovable, reclaimable and movable on pcp lists.
1540 * Free ISOLATE pages back to the allocator because they are being
1541 * offlined but treat RESERVE as movable pages so we can get those
1542 * areas back if necessary. Otherwise, we may have to free
1543 * excessively into the page allocator
1545 if (migratetype >= MIGRATE_PCPTYPES) {
1546 if (unlikely(is_migrate_isolate(migratetype))) {
1547 free_one_page(zone, page, pfn, 0, migratetype);
1550 migratetype = MIGRATE_MOVABLE;
1553 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1555 list_add(&page->lru, &pcp->lists[migratetype]);
1557 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1559 if (pcp->count >= pcp->high) {
1560 unsigned long batch = READ_ONCE(pcp->batch);
1561 free_pcppages_bulk(zone, batch, pcp);
1562 pcp->count -= batch;
1566 local_irq_restore(flags);
1570 * Free a list of 0-order pages
1572 void free_hot_cold_page_list(struct list_head *list, bool cold)
1574 struct page *page, *next;
1576 list_for_each_entry_safe(page, next, list, lru) {
1577 trace_mm_page_free_batched(page, cold);
1578 free_hot_cold_page(page, cold);
1583 * split_page takes a non-compound higher-order page, and splits it into
1584 * n (1<<order) sub-pages: page[0..n]
1585 * Each sub-page must be freed individually.
1587 * Note: this is probably too low level an operation for use in drivers.
1588 * Please consult with lkml before using this in your driver.
1590 void split_page(struct page *page, unsigned int order)
1594 VM_BUG_ON_PAGE(PageCompound(page), page);
1595 VM_BUG_ON_PAGE(!page_count(page), page);
1597 #ifdef CONFIG_KMEMCHECK
1599 * Split shadow pages too, because free(page[0]) would
1600 * otherwise free the whole shadow.
1602 if (kmemcheck_page_is_tracked(page))
1603 split_page(virt_to_page(page[0].shadow), order);
1606 set_page_owner(page, 0, 0);
1607 for (i = 1; i < (1 << order); i++) {
1608 set_page_refcounted(page + i);
1609 set_page_owner(page + i, 0, 0);
1612 EXPORT_SYMBOL_GPL(split_page);
1614 int __isolate_free_page(struct page *page, unsigned int order)
1616 unsigned long watermark;
1620 BUG_ON(!PageBuddy(page));
1622 zone = page_zone(page);
1623 mt = get_pageblock_migratetype(page);
1625 if (!is_migrate_isolate(mt)) {
1626 /* Obey watermarks as if the page was being allocated */
1627 watermark = low_wmark_pages(zone) + (1 << order);
1628 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1631 __mod_zone_freepage_state(zone, -(1UL << order), mt);
1634 /* Remove page from free list */
1635 list_del(&page->lru);
1636 zone->free_area[order].nr_free--;
1637 rmv_page_order(page);
1639 /* Set the pageblock if the isolated page is at least a pageblock */
1640 if (order >= pageblock_order - 1) {
1641 struct page *endpage = page + (1 << order) - 1;
1642 for (; page < endpage; page += pageblock_nr_pages) {
1643 int mt = get_pageblock_migratetype(page);
1644 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
1645 set_pageblock_migratetype(page,
1650 set_page_owner(page, order, 0);
1651 return 1UL << order;
1655 * Similar to split_page except the page is already free. As this is only
1656 * being used for migration, the migratetype of the block also changes.
1657 * As this is called with interrupts disabled, the caller is responsible
1658 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1661 * Note: this is probably too low level an operation for use in drivers.
1662 * Please consult with lkml before using this in your driver.
1664 int split_free_page(struct page *page)
1669 order = page_order(page);
1671 nr_pages = __isolate_free_page(page, order);
1675 /* Split into individual pages */
1676 set_page_refcounted(page);
1677 split_page(page, order);
1682 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
1685 struct page *buffered_rmqueue(struct zone *preferred_zone,
1686 struct zone *zone, unsigned int order,
1687 gfp_t gfp_flags, int migratetype)
1689 unsigned long flags;
1691 bool cold = ((gfp_flags & __GFP_COLD) != 0);
1693 if (likely(order == 0)) {
1694 struct per_cpu_pages *pcp;
1695 struct list_head *list;
1697 local_irq_save(flags);
1698 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1699 list = &pcp->lists[migratetype];
1700 if (list_empty(list)) {
1701 pcp->count += rmqueue_bulk(zone, 0,
1704 if (unlikely(list_empty(list)))
1709 page = list_entry(list->prev, struct page, lru);
1711 page = list_entry(list->next, struct page, lru);
1713 list_del(&page->lru);
1716 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1718 * __GFP_NOFAIL is not to be used in new code.
1720 * All __GFP_NOFAIL callers should be fixed so that they
1721 * properly detect and handle allocation failures.
1723 * We most definitely don't want callers attempting to
1724 * allocate greater than order-1 page units with
1727 WARN_ON_ONCE(order > 1);
1729 spin_lock_irqsave(&zone->lock, flags);
1730 page = __rmqueue(zone, order, migratetype);
1731 spin_unlock(&zone->lock);
1734 __mod_zone_freepage_state(zone, -(1 << order),
1735 get_freepage_migratetype(page));
1738 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
1739 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
1740 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
1741 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
1743 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1744 zone_statistics(preferred_zone, zone, gfp_flags);
1745 local_irq_restore(flags);
1747 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1751 local_irq_restore(flags);
1755 #ifdef CONFIG_FAIL_PAGE_ALLOC
1758 struct fault_attr attr;
1760 u32 ignore_gfp_highmem;
1761 u32 ignore_gfp_wait;
1763 } fail_page_alloc = {
1764 .attr = FAULT_ATTR_INITIALIZER,
1765 .ignore_gfp_wait = 1,
1766 .ignore_gfp_highmem = 1,
1770 static int __init setup_fail_page_alloc(char *str)
1772 return setup_fault_attr(&fail_page_alloc.attr, str);
1774 __setup("fail_page_alloc=", setup_fail_page_alloc);
1776 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1778 if (order < fail_page_alloc.min_order)
1780 if (gfp_mask & __GFP_NOFAIL)
1782 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1784 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1787 return should_fail(&fail_page_alloc.attr, 1 << order);
1790 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1792 static int __init fail_page_alloc_debugfs(void)
1794 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1797 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1798 &fail_page_alloc.attr);
1800 return PTR_ERR(dir);
1802 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1803 &fail_page_alloc.ignore_gfp_wait))
1805 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1806 &fail_page_alloc.ignore_gfp_highmem))
1808 if (!debugfs_create_u32("min-order", mode, dir,
1809 &fail_page_alloc.min_order))
1814 debugfs_remove_recursive(dir);
1819 late_initcall(fail_page_alloc_debugfs);
1821 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1823 #else /* CONFIG_FAIL_PAGE_ALLOC */
1825 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1830 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1833 * Return true if free pages are above 'mark'. This takes into account the order
1834 * of the allocation.
1836 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
1837 unsigned long mark, int classzone_idx, int alloc_flags,
1840 /* free_pages may go negative - that's OK */
1845 free_pages -= (1 << order) - 1;
1846 if (alloc_flags & ALLOC_HIGH)
1848 if (alloc_flags & ALLOC_HARDER)
1851 /* If allocation can't use CMA areas don't use free CMA pages */
1852 if (!(alloc_flags & ALLOC_CMA))
1853 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
1856 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
1858 for (o = 0; o < order; o++) {
1859 /* At the next order, this order's pages become unavailable */
1860 free_pages -= z->free_area[o].nr_free << o;
1862 /* Require fewer higher order pages to be free */
1865 if (free_pages <= min)
1871 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1872 int classzone_idx, int alloc_flags)
1874 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1875 zone_page_state(z, NR_FREE_PAGES));
1878 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1879 unsigned long mark, int classzone_idx, int alloc_flags)
1881 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1883 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1884 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1886 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1892 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1893 * skip over zones that are not allowed by the cpuset, or that have
1894 * been recently (in last second) found to be nearly full. See further
1895 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1896 * that have to skip over a lot of full or unallowed zones.
1898 * If the zonelist cache is present in the passed zonelist, then
1899 * returns a pointer to the allowed node mask (either the current
1900 * tasks mems_allowed, or node_states[N_MEMORY].)
1902 * If the zonelist cache is not available for this zonelist, does
1903 * nothing and returns NULL.
1905 * If the fullzones BITMAP in the zonelist cache is stale (more than
1906 * a second since last zap'd) then we zap it out (clear its bits.)
1908 * We hold off even calling zlc_setup, until after we've checked the
1909 * first zone in the zonelist, on the theory that most allocations will
1910 * be satisfied from that first zone, so best to examine that zone as
1911 * quickly as we can.
1913 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1915 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1916 nodemask_t *allowednodes; /* zonelist_cache approximation */
1918 zlc = zonelist->zlcache_ptr;
1922 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1923 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1924 zlc->last_full_zap = jiffies;
1927 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1928 &cpuset_current_mems_allowed :
1929 &node_states[N_MEMORY];
1930 return allowednodes;
1934 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1935 * if it is worth looking at further for free memory:
1936 * 1) Check that the zone isn't thought to be full (doesn't have its
1937 * bit set in the zonelist_cache fullzones BITMAP).
1938 * 2) Check that the zones node (obtained from the zonelist_cache
1939 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1940 * Return true (non-zero) if zone is worth looking at further, or
1941 * else return false (zero) if it is not.
1943 * This check -ignores- the distinction between various watermarks,
1944 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1945 * found to be full for any variation of these watermarks, it will
1946 * be considered full for up to one second by all requests, unless
1947 * we are so low on memory on all allowed nodes that we are forced
1948 * into the second scan of the zonelist.
1950 * In the second scan we ignore this zonelist cache and exactly
1951 * apply the watermarks to all zones, even it is slower to do so.
1952 * We are low on memory in the second scan, and should leave no stone
1953 * unturned looking for a free page.
1955 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1956 nodemask_t *allowednodes)
1958 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1959 int i; /* index of *z in zonelist zones */
1960 int n; /* node that zone *z is on */
1962 zlc = zonelist->zlcache_ptr;
1966 i = z - zonelist->_zonerefs;
1969 /* This zone is worth trying if it is allowed but not full */
1970 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1974 * Given 'z' scanning a zonelist, set the corresponding bit in
1975 * zlc->fullzones, so that subsequent attempts to allocate a page
1976 * from that zone don't waste time re-examining it.
1978 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1980 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1981 int i; /* index of *z in zonelist zones */
1983 zlc = zonelist->zlcache_ptr;
1987 i = z - zonelist->_zonerefs;
1989 set_bit(i, zlc->fullzones);
1993 * clear all zones full, called after direct reclaim makes progress so that
1994 * a zone that was recently full is not skipped over for up to a second
1996 static void zlc_clear_zones_full(struct zonelist *zonelist)
1998 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2000 zlc = zonelist->zlcache_ptr;
2004 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2007 static bool zone_local(struct zone *local_zone, struct zone *zone)
2009 return local_zone->node == zone->node;
2012 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2014 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2018 #else /* CONFIG_NUMA */
2020 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
2025 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
2026 nodemask_t *allowednodes)
2031 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
2035 static void zlc_clear_zones_full(struct zonelist *zonelist)
2039 static bool zone_local(struct zone *local_zone, struct zone *zone)
2044 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2049 #endif /* CONFIG_NUMA */
2051 static void reset_alloc_batches(struct zone *preferred_zone)
2053 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2056 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2057 high_wmark_pages(zone) - low_wmark_pages(zone) -
2058 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2059 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2060 } while (zone++ != preferred_zone);
2064 * get_page_from_freelist goes through the zonelist trying to allocate
2067 static struct page *
2068 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2069 const struct alloc_context *ac)
2071 struct zonelist *zonelist = ac->zonelist;
2073 struct page *page = NULL;
2075 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
2076 int zlc_active = 0; /* set if using zonelist_cache */
2077 int did_zlc_setup = 0; /* just call zlc_setup() one time */
2078 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
2079 (gfp_mask & __GFP_WRITE);
2080 int nr_fair_skipped = 0;
2081 bool zonelist_rescan;
2084 zonelist_rescan = false;
2087 * Scan zonelist, looking for a zone with enough free.
2088 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2090 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2094 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2095 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2097 if (cpusets_enabled() &&
2098 (alloc_flags & ALLOC_CPUSET) &&
2099 !cpuset_zone_allowed(zone, gfp_mask))
2102 * Distribute pages in proportion to the individual
2103 * zone size to ensure fair page aging. The zone a
2104 * page was allocated in should have no effect on the
2105 * time the page has in memory before being reclaimed.
2107 if (alloc_flags & ALLOC_FAIR) {
2108 if (!zone_local(ac->preferred_zone, zone))
2110 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2116 * When allocating a page cache page for writing, we
2117 * want to get it from a zone that is within its dirty
2118 * limit, such that no single zone holds more than its
2119 * proportional share of globally allowed dirty pages.
2120 * The dirty limits take into account the zone's
2121 * lowmem reserves and high watermark so that kswapd
2122 * should be able to balance it without having to
2123 * write pages from its LRU list.
2125 * This may look like it could increase pressure on
2126 * lower zones by failing allocations in higher zones
2127 * before they are full. But the pages that do spill
2128 * over are limited as the lower zones are protected
2129 * by this very same mechanism. It should not become
2130 * a practical burden to them.
2132 * XXX: For now, allow allocations to potentially
2133 * exceed the per-zone dirty limit in the slowpath
2134 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2135 * which is important when on a NUMA setup the allowed
2136 * zones are together not big enough to reach the
2137 * global limit. The proper fix for these situations
2138 * will require awareness of zones in the
2139 * dirty-throttling and the flusher threads.
2141 if (consider_zone_dirty && !zone_dirty_ok(zone))
2144 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2145 if (!zone_watermark_ok(zone, order, mark,
2146 ac->classzone_idx, alloc_flags)) {
2149 /* Checked here to keep the fast path fast */
2150 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2151 if (alloc_flags & ALLOC_NO_WATERMARKS)
2154 if (IS_ENABLED(CONFIG_NUMA) &&
2155 !did_zlc_setup && nr_online_nodes > 1) {
2157 * we do zlc_setup if there are multiple nodes
2158 * and before considering the first zone allowed
2161 allowednodes = zlc_setup(zonelist, alloc_flags);
2166 if (zone_reclaim_mode == 0 ||
2167 !zone_allows_reclaim(ac->preferred_zone, zone))
2168 goto this_zone_full;
2171 * As we may have just activated ZLC, check if the first
2172 * eligible zone has failed zone_reclaim recently.
2174 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2175 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2178 ret = zone_reclaim(zone, gfp_mask, order);
2180 case ZONE_RECLAIM_NOSCAN:
2183 case ZONE_RECLAIM_FULL:
2184 /* scanned but unreclaimable */
2187 /* did we reclaim enough */
2188 if (zone_watermark_ok(zone, order, mark,
2189 ac->classzone_idx, alloc_flags))
2193 * Failed to reclaim enough to meet watermark.
2194 * Only mark the zone full if checking the min
2195 * watermark or if we failed to reclaim just
2196 * 1<<order pages or else the page allocator
2197 * fastpath will prematurely mark zones full
2198 * when the watermark is between the low and
2201 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2202 ret == ZONE_RECLAIM_SOME)
2203 goto this_zone_full;
2210 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2211 gfp_mask, ac->migratetype);
2213 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2218 if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
2219 zlc_mark_zone_full(zonelist, z);
2223 * The first pass makes sure allocations are spread fairly within the
2224 * local node. However, the local node might have free pages left
2225 * after the fairness batches are exhausted, and remote zones haven't
2226 * even been considered yet. Try once more without fairness, and
2227 * include remote zones now, before entering the slowpath and waking
2228 * kswapd: prefer spilling to a remote zone over swapping locally.
2230 if (alloc_flags & ALLOC_FAIR) {
2231 alloc_flags &= ~ALLOC_FAIR;
2232 if (nr_fair_skipped) {
2233 zonelist_rescan = true;
2234 reset_alloc_batches(ac->preferred_zone);
2236 if (nr_online_nodes > 1)
2237 zonelist_rescan = true;
2240 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) {
2241 /* Disable zlc cache for second zonelist scan */
2243 zonelist_rescan = true;
2246 if (zonelist_rescan)
2253 * Large machines with many possible nodes should not always dump per-node
2254 * meminfo in irq context.
2256 static inline bool should_suppress_show_mem(void)
2261 ret = in_interrupt();
2266 static DEFINE_RATELIMIT_STATE(nopage_rs,
2267 DEFAULT_RATELIMIT_INTERVAL,
2268 DEFAULT_RATELIMIT_BURST);
2270 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2272 unsigned int filter = SHOW_MEM_FILTER_NODES;
2274 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2275 debug_guardpage_minorder() > 0)
2279 * This documents exceptions given to allocations in certain
2280 * contexts that are allowed to allocate outside current's set
2283 if (!(gfp_mask & __GFP_NOMEMALLOC))
2284 if (test_thread_flag(TIF_MEMDIE) ||
2285 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2286 filter &= ~SHOW_MEM_FILTER_NODES;
2287 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2288 filter &= ~SHOW_MEM_FILTER_NODES;
2291 struct va_format vaf;
2294 va_start(args, fmt);
2299 pr_warn("%pV", &vaf);
2304 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2305 current->comm, order, gfp_mask);
2308 if (!should_suppress_show_mem())
2312 static inline struct page *
2313 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2314 const struct alloc_context *ac, unsigned long *did_some_progress)
2318 *did_some_progress = 0;
2321 * Acquire the oom lock. If that fails, somebody else is
2322 * making progress for us.
2324 if (!mutex_trylock(&oom_lock)) {
2325 *did_some_progress = 1;
2326 schedule_timeout_uninterruptible(1);
2331 * Go through the zonelist yet one more time, keep very high watermark
2332 * here, this is only to catch a parallel oom killing, we must fail if
2333 * we're still under heavy pressure.
2335 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2336 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2340 if (!(gfp_mask & __GFP_NOFAIL)) {
2341 /* Coredumps can quickly deplete all memory reserves */
2342 if (current->flags & PF_DUMPCORE)
2344 /* The OOM killer will not help higher order allocs */
2345 if (order > PAGE_ALLOC_COSTLY_ORDER)
2347 /* The OOM killer does not needlessly kill tasks for lowmem */
2348 if (ac->high_zoneidx < ZONE_NORMAL)
2350 /* The OOM killer does not compensate for IO-less reclaim */
2351 if (!(gfp_mask & __GFP_FS)) {
2353 * XXX: Page reclaim didn't yield anything,
2354 * and the OOM killer can't be invoked, but
2355 * keep looping as per tradition.
2357 *did_some_progress = 1;
2360 if (pm_suspended_storage())
2362 /* The OOM killer may not free memory on a specific node */
2363 if (gfp_mask & __GFP_THISNODE)
2366 /* Exhausted what can be done so it's blamo time */
2367 if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false)
2368 || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
2369 *did_some_progress = 1;
2371 mutex_unlock(&oom_lock);
2375 #ifdef CONFIG_COMPACTION
2376 /* Try memory compaction for high-order allocations before reclaim */
2377 static struct page *
2378 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2379 int alloc_flags, const struct alloc_context *ac,
2380 enum migrate_mode mode, int *contended_compaction,
2381 bool *deferred_compaction)
2383 unsigned long compact_result;
2389 current->flags |= PF_MEMALLOC;
2390 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2391 mode, contended_compaction);
2392 current->flags &= ~PF_MEMALLOC;
2394 switch (compact_result) {
2395 case COMPACT_DEFERRED:
2396 *deferred_compaction = true;
2398 case COMPACT_SKIPPED:
2405 * At least in one zone compaction wasn't deferred or skipped, so let's
2406 * count a compaction stall
2408 count_vm_event(COMPACTSTALL);
2410 page = get_page_from_freelist(gfp_mask, order,
2411 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2414 struct zone *zone = page_zone(page);
2416 zone->compact_blockskip_flush = false;
2417 compaction_defer_reset(zone, order, true);
2418 count_vm_event(COMPACTSUCCESS);
2423 * It's bad if compaction run occurs and fails. The most likely reason
2424 * is that pages exist, but not enough to satisfy watermarks.
2426 count_vm_event(COMPACTFAIL);
2433 static inline struct page *
2434 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2435 int alloc_flags, const struct alloc_context *ac,
2436 enum migrate_mode mode, int *contended_compaction,
2437 bool *deferred_compaction)
2441 #endif /* CONFIG_COMPACTION */
2443 /* Perform direct synchronous page reclaim */
2445 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
2446 const struct alloc_context *ac)
2448 struct reclaim_state reclaim_state;
2453 /* We now go into synchronous reclaim */
2454 cpuset_memory_pressure_bump();
2455 current->flags |= PF_MEMALLOC;
2456 lockdep_set_current_reclaim_state(gfp_mask);
2457 reclaim_state.reclaimed_slab = 0;
2458 current->reclaim_state = &reclaim_state;
2460 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
2463 current->reclaim_state = NULL;
2464 lockdep_clear_current_reclaim_state();
2465 current->flags &= ~PF_MEMALLOC;
2472 /* The really slow allocator path where we enter direct reclaim */
2473 static inline struct page *
2474 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2475 int alloc_flags, const struct alloc_context *ac,
2476 unsigned long *did_some_progress)
2478 struct page *page = NULL;
2479 bool drained = false;
2481 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
2482 if (unlikely(!(*did_some_progress)))
2485 /* After successful reclaim, reconsider all zones for allocation */
2486 if (IS_ENABLED(CONFIG_NUMA))
2487 zlc_clear_zones_full(ac->zonelist);
2490 page = get_page_from_freelist(gfp_mask, order,
2491 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2494 * If an allocation failed after direct reclaim, it could be because
2495 * pages are pinned on the per-cpu lists. Drain them and try again
2497 if (!page && !drained) {
2498 drain_all_pages(NULL);
2507 * This is called in the allocator slow-path if the allocation request is of
2508 * sufficient urgency to ignore watermarks and take other desperate measures
2510 static inline struct page *
2511 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2512 const struct alloc_context *ac)
2517 page = get_page_from_freelist(gfp_mask, order,
2518 ALLOC_NO_WATERMARKS, ac);
2520 if (!page && gfp_mask & __GFP_NOFAIL)
2521 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC,
2523 } while (!page && (gfp_mask & __GFP_NOFAIL));
2528 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
2533 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
2534 ac->high_zoneidx, ac->nodemask)
2535 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
2539 gfp_to_alloc_flags(gfp_t gfp_mask)
2541 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2542 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
2544 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2545 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2548 * The caller may dip into page reserves a bit more if the caller
2549 * cannot run direct reclaim, or if the caller has realtime scheduling
2550 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2551 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2553 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2557 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2558 * if it can't schedule.
2560 if (!(gfp_mask & __GFP_NOMEMALLOC))
2561 alloc_flags |= ALLOC_HARDER;
2563 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2564 * comment for __cpuset_node_allowed().
2566 alloc_flags &= ~ALLOC_CPUSET;
2567 } else if (unlikely(rt_task(current)) && !in_interrupt())
2568 alloc_flags |= ALLOC_HARDER;
2570 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2571 if (gfp_mask & __GFP_MEMALLOC)
2572 alloc_flags |= ALLOC_NO_WATERMARKS;
2573 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2574 alloc_flags |= ALLOC_NO_WATERMARKS;
2575 else if (!in_interrupt() &&
2576 ((current->flags & PF_MEMALLOC) ||
2577 unlikely(test_thread_flag(TIF_MEMDIE))))
2578 alloc_flags |= ALLOC_NO_WATERMARKS;
2581 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2582 alloc_flags |= ALLOC_CMA;
2587 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2589 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2592 static inline struct page *
2593 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2594 struct alloc_context *ac)
2596 const gfp_t wait = gfp_mask & __GFP_WAIT;
2597 struct page *page = NULL;
2599 unsigned long pages_reclaimed = 0;
2600 unsigned long did_some_progress;
2601 enum migrate_mode migration_mode = MIGRATE_ASYNC;
2602 bool deferred_compaction = false;
2603 int contended_compaction = COMPACT_CONTENDED_NONE;
2606 * In the slowpath, we sanity check order to avoid ever trying to
2607 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2608 * be using allocators in order of preference for an area that is
2611 if (order >= MAX_ORDER) {
2612 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2617 * If this allocation cannot block and it is for a specific node, then
2618 * fail early. There's no need to wakeup kswapd or retry for a
2619 * speculative node-specific allocation.
2621 if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait)
2625 if (!(gfp_mask & __GFP_NO_KSWAPD))
2626 wake_all_kswapds(order, ac);
2629 * OK, we're below the kswapd watermark and have kicked background
2630 * reclaim. Now things get more complex, so set up alloc_flags according
2631 * to how we want to proceed.
2633 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2636 * Find the true preferred zone if the allocation is unconstrained by
2639 if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) {
2640 struct zoneref *preferred_zoneref;
2641 preferred_zoneref = first_zones_zonelist(ac->zonelist,
2642 ac->high_zoneidx, NULL, &ac->preferred_zone);
2643 ac->classzone_idx = zonelist_zone_idx(preferred_zoneref);
2646 /* This is the last chance, in general, before the goto nopage. */
2647 page = get_page_from_freelist(gfp_mask, order,
2648 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2652 /* Allocate without watermarks if the context allows */
2653 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2655 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2656 * the allocation is high priority and these type of
2657 * allocations are system rather than user orientated
2659 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
2661 page = __alloc_pages_high_priority(gfp_mask, order, ac);
2668 /* Atomic allocations - we can't balance anything */
2671 * All existing users of the deprecated __GFP_NOFAIL are
2672 * blockable, so warn of any new users that actually allow this
2673 * type of allocation to fail.
2675 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
2679 /* Avoid recursion of direct reclaim */
2680 if (current->flags & PF_MEMALLOC)
2683 /* Avoid allocations with no watermarks from looping endlessly */
2684 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2688 * Try direct compaction. The first pass is asynchronous. Subsequent
2689 * attempts after direct reclaim are synchronous
2691 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
2693 &contended_compaction,
2694 &deferred_compaction);
2698 /* Checks for THP-specific high-order allocations */
2699 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) {
2701 * If compaction is deferred for high-order allocations, it is
2702 * because sync compaction recently failed. If this is the case
2703 * and the caller requested a THP allocation, we do not want
2704 * to heavily disrupt the system, so we fail the allocation
2705 * instead of entering direct reclaim.
2707 if (deferred_compaction)
2711 * In all zones where compaction was attempted (and not
2712 * deferred or skipped), lock contention has been detected.
2713 * For THP allocation we do not want to disrupt the others
2714 * so we fallback to base pages instead.
2716 if (contended_compaction == COMPACT_CONTENDED_LOCK)
2720 * If compaction was aborted due to need_resched(), we do not
2721 * want to further increase allocation latency, unless it is
2722 * khugepaged trying to collapse.
2724 if (contended_compaction == COMPACT_CONTENDED_SCHED
2725 && !(current->flags & PF_KTHREAD))
2730 * It can become very expensive to allocate transparent hugepages at
2731 * fault, so use asynchronous memory compaction for THP unless it is
2732 * khugepaged trying to collapse.
2734 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE ||
2735 (current->flags & PF_KTHREAD))
2736 migration_mode = MIGRATE_SYNC_LIGHT;
2738 /* Try direct reclaim and then allocating */
2739 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
2740 &did_some_progress);
2744 /* Do not loop if specifically requested */
2745 if (gfp_mask & __GFP_NORETRY)
2748 /* Keep reclaiming pages as long as there is reasonable progress */
2749 pages_reclaimed += did_some_progress;
2750 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
2751 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
2752 /* Wait for some write requests to complete then retry */
2753 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
2757 /* Reclaim has failed us, start killing things */
2758 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
2762 /* Retry as long as the OOM killer is making progress */
2763 if (did_some_progress)
2768 * High-order allocations do not necessarily loop after
2769 * direct reclaim and reclaim/compaction depends on compaction
2770 * being called after reclaim so call directly if necessary
2772 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
2774 &contended_compaction,
2775 &deferred_compaction);
2779 warn_alloc_failed(gfp_mask, order, NULL);
2785 * This is the 'heart' of the zoned buddy allocator.
2788 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2789 struct zonelist *zonelist, nodemask_t *nodemask)
2791 struct zoneref *preferred_zoneref;
2792 struct page *page = NULL;
2793 unsigned int cpuset_mems_cookie;
2794 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
2795 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
2796 struct alloc_context ac = {
2797 .high_zoneidx = gfp_zone(gfp_mask),
2798 .nodemask = nodemask,
2799 .migratetype = gfpflags_to_migratetype(gfp_mask),
2802 gfp_mask &= gfp_allowed_mask;
2804 lockdep_trace_alloc(gfp_mask);
2806 might_sleep_if(gfp_mask & __GFP_WAIT);
2808 if (should_fail_alloc_page(gfp_mask, order))
2812 * Check the zones suitable for the gfp_mask contain at least one
2813 * valid zone. It's possible to have an empty zonelist as a result
2814 * of __GFP_THISNODE and a memoryless node
2816 if (unlikely(!zonelist->_zonerefs->zone))
2819 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
2820 alloc_flags |= ALLOC_CMA;
2823 cpuset_mems_cookie = read_mems_allowed_begin();
2825 /* We set it here, as __alloc_pages_slowpath might have changed it */
2826 ac.zonelist = zonelist;
2827 /* The preferred zone is used for statistics later */
2828 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
2829 ac.nodemask ? : &cpuset_current_mems_allowed,
2830 &ac.preferred_zone);
2831 if (!ac.preferred_zone)
2833 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
2835 /* First allocation attempt */
2836 alloc_mask = gfp_mask|__GFP_HARDWALL;
2837 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
2838 if (unlikely(!page)) {
2840 * Runtime PM, block IO and its error handling path
2841 * can deadlock because I/O on the device might not
2844 alloc_mask = memalloc_noio_flags(gfp_mask);
2846 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
2849 if (kmemcheck_enabled && page)
2850 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2852 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
2856 * When updating a task's mems_allowed, it is possible to race with
2857 * parallel threads in such a way that an allocation can fail while
2858 * the mask is being updated. If a page allocation is about to fail,
2859 * check if the cpuset changed during allocation and if so, retry.
2861 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2866 EXPORT_SYMBOL(__alloc_pages_nodemask);
2869 * Common helper functions.
2871 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2876 * __get_free_pages() returns a 32-bit address, which cannot represent
2879 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2881 page = alloc_pages(gfp_mask, order);
2884 return (unsigned long) page_address(page);
2886 EXPORT_SYMBOL(__get_free_pages);
2888 unsigned long get_zeroed_page(gfp_t gfp_mask)
2890 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2892 EXPORT_SYMBOL(get_zeroed_page);
2894 void __free_pages(struct page *page, unsigned int order)
2896 if (put_page_testzero(page)) {
2898 free_hot_cold_page(page, false);
2900 __free_pages_ok(page, order);
2904 EXPORT_SYMBOL(__free_pages);
2906 void free_pages(unsigned long addr, unsigned int order)
2909 VM_BUG_ON(!virt_addr_valid((void *)addr));
2910 __free_pages(virt_to_page((void *)addr), order);
2914 EXPORT_SYMBOL(free_pages);
2917 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
2918 * of the current memory cgroup.
2920 * It should be used when the caller would like to use kmalloc, but since the
2921 * allocation is large, it has to fall back to the page allocator.
2923 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
2926 struct mem_cgroup *memcg = NULL;
2928 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2930 page = alloc_pages(gfp_mask, order);
2931 memcg_kmem_commit_charge(page, memcg, order);
2935 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
2938 struct mem_cgroup *memcg = NULL;
2940 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2942 page = alloc_pages_node(nid, gfp_mask, order);
2943 memcg_kmem_commit_charge(page, memcg, order);
2948 * __free_kmem_pages and free_kmem_pages will free pages allocated with
2951 void __free_kmem_pages(struct page *page, unsigned int order)
2953 memcg_kmem_uncharge_pages(page, order);
2954 __free_pages(page, order);
2957 void free_kmem_pages(unsigned long addr, unsigned int order)
2960 VM_BUG_ON(!virt_addr_valid((void *)addr));
2961 __free_kmem_pages(virt_to_page((void *)addr), order);
2965 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2968 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2969 unsigned long used = addr + PAGE_ALIGN(size);
2971 split_page(virt_to_page((void *)addr), order);
2972 while (used < alloc_end) {
2977 return (void *)addr;
2981 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2982 * @size: the number of bytes to allocate
2983 * @gfp_mask: GFP flags for the allocation
2985 * This function is similar to alloc_pages(), except that it allocates the
2986 * minimum number of pages to satisfy the request. alloc_pages() can only
2987 * allocate memory in power-of-two pages.
2989 * This function is also limited by MAX_ORDER.
2991 * Memory allocated by this function must be released by free_pages_exact().
2993 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2995 unsigned int order = get_order(size);
2998 addr = __get_free_pages(gfp_mask, order);
2999 return make_alloc_exact(addr, order, size);
3001 EXPORT_SYMBOL(alloc_pages_exact);
3004 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3006 * @nid: the preferred node ID where memory should be allocated
3007 * @size: the number of bytes to allocate
3008 * @gfp_mask: GFP flags for the allocation
3010 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3012 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
3015 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3017 unsigned order = get_order(size);
3018 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3021 return make_alloc_exact((unsigned long)page_address(p), order, size);
3025 * free_pages_exact - release memory allocated via alloc_pages_exact()
3026 * @virt: the value returned by alloc_pages_exact.
3027 * @size: size of allocation, same value as passed to alloc_pages_exact().
3029 * Release the memory allocated by a previous call to alloc_pages_exact.
3031 void free_pages_exact(void *virt, size_t size)
3033 unsigned long addr = (unsigned long)virt;
3034 unsigned long end = addr + PAGE_ALIGN(size);
3036 while (addr < end) {
3041 EXPORT_SYMBOL(free_pages_exact);
3044 * nr_free_zone_pages - count number of pages beyond high watermark
3045 * @offset: The zone index of the highest zone
3047 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3048 * high watermark within all zones at or below a given zone index. For each
3049 * zone, the number of pages is calculated as:
3050 * managed_pages - high_pages
3052 static unsigned long nr_free_zone_pages(int offset)
3057 /* Just pick one node, since fallback list is circular */
3058 unsigned long sum = 0;
3060 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3062 for_each_zone_zonelist(zone, z, zonelist, offset) {
3063 unsigned long size = zone->managed_pages;
3064 unsigned long high = high_wmark_pages(zone);
3073 * nr_free_buffer_pages - count number of pages beyond high watermark
3075 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3076 * watermark within ZONE_DMA and ZONE_NORMAL.
3078 unsigned long nr_free_buffer_pages(void)
3080 return nr_free_zone_pages(gfp_zone(GFP_USER));
3082 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3085 * nr_free_pagecache_pages - count number of pages beyond high watermark
3087 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3088 * high watermark within all zones.
3090 unsigned long nr_free_pagecache_pages(void)
3092 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3095 static inline void show_node(struct zone *zone)
3097 if (IS_ENABLED(CONFIG_NUMA))
3098 printk("Node %d ", zone_to_nid(zone));
3101 void si_meminfo(struct sysinfo *val)
3103 val->totalram = totalram_pages;
3104 val->sharedram = global_page_state(NR_SHMEM);
3105 val->freeram = global_page_state(NR_FREE_PAGES);
3106 val->bufferram = nr_blockdev_pages();
3107 val->totalhigh = totalhigh_pages;
3108 val->freehigh = nr_free_highpages();
3109 val->mem_unit = PAGE_SIZE;
3112 EXPORT_SYMBOL(si_meminfo);
3115 void si_meminfo_node(struct sysinfo *val, int nid)
3117 int zone_type; /* needs to be signed */
3118 unsigned long managed_pages = 0;
3119 pg_data_t *pgdat = NODE_DATA(nid);
3121 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3122 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3123 val->totalram = managed_pages;
3124 val->sharedram = node_page_state(nid, NR_SHMEM);
3125 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3126 #ifdef CONFIG_HIGHMEM
3127 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3128 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3134 val->mem_unit = PAGE_SIZE;
3139 * Determine whether the node should be displayed or not, depending on whether
3140 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3142 bool skip_free_areas_node(unsigned int flags, int nid)
3145 unsigned int cpuset_mems_cookie;
3147 if (!(flags & SHOW_MEM_FILTER_NODES))
3151 cpuset_mems_cookie = read_mems_allowed_begin();
3152 ret = !node_isset(nid, cpuset_current_mems_allowed);
3153 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3158 #define K(x) ((x) << (PAGE_SHIFT-10))
3160 static void show_migration_types(unsigned char type)
3162 static const char types[MIGRATE_TYPES] = {
3163 [MIGRATE_UNMOVABLE] = 'U',
3164 [MIGRATE_RECLAIMABLE] = 'E',
3165 [MIGRATE_MOVABLE] = 'M',
3166 [MIGRATE_RESERVE] = 'R',
3168 [MIGRATE_CMA] = 'C',
3170 #ifdef CONFIG_MEMORY_ISOLATION
3171 [MIGRATE_ISOLATE] = 'I',
3174 char tmp[MIGRATE_TYPES + 1];
3178 for (i = 0; i < MIGRATE_TYPES; i++) {
3179 if (type & (1 << i))
3184 printk("(%s) ", tmp);
3188 * Show free area list (used inside shift_scroll-lock stuff)
3189 * We also calculate the percentage fragmentation. We do this by counting the
3190 * memory on each free list with the exception of the first item on the list.
3193 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3196 void show_free_areas(unsigned int filter)
3198 unsigned long free_pcp = 0;
3202 for_each_populated_zone(zone) {
3203 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3206 for_each_online_cpu(cpu)
3207 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3210 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3211 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3212 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3213 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3214 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3215 " free:%lu free_pcp:%lu free_cma:%lu\n",
3216 global_page_state(NR_ACTIVE_ANON),
3217 global_page_state(NR_INACTIVE_ANON),
3218 global_page_state(NR_ISOLATED_ANON),
3219 global_page_state(NR_ACTIVE_FILE),
3220 global_page_state(NR_INACTIVE_FILE),
3221 global_page_state(NR_ISOLATED_FILE),
3222 global_page_state(NR_UNEVICTABLE),
3223 global_page_state(NR_FILE_DIRTY),
3224 global_page_state(NR_WRITEBACK),
3225 global_page_state(NR_UNSTABLE_NFS),
3226 global_page_state(NR_SLAB_RECLAIMABLE),
3227 global_page_state(NR_SLAB_UNRECLAIMABLE),
3228 global_page_state(NR_FILE_MAPPED),
3229 global_page_state(NR_SHMEM),
3230 global_page_state(NR_PAGETABLE),
3231 global_page_state(NR_BOUNCE),
3232 global_page_state(NR_FREE_PAGES),
3234 global_page_state(NR_FREE_CMA_PAGES));
3236 for_each_populated_zone(zone) {
3239 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3243 for_each_online_cpu(cpu)
3244 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3252 " active_anon:%lukB"
3253 " inactive_anon:%lukB"
3254 " active_file:%lukB"
3255 " inactive_file:%lukB"
3256 " unevictable:%lukB"
3257 " isolated(anon):%lukB"
3258 " isolated(file):%lukB"
3266 " slab_reclaimable:%lukB"
3267 " slab_unreclaimable:%lukB"
3268 " kernel_stack:%lukB"
3275 " writeback_tmp:%lukB"
3276 " pages_scanned:%lu"
3277 " all_unreclaimable? %s"
3280 K(zone_page_state(zone, NR_FREE_PAGES)),
3281 K(min_wmark_pages(zone)),
3282 K(low_wmark_pages(zone)),
3283 K(high_wmark_pages(zone)),
3284 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3285 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3286 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3287 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3288 K(zone_page_state(zone, NR_UNEVICTABLE)),
3289 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3290 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3291 K(zone->present_pages),
3292 K(zone->managed_pages),
3293 K(zone_page_state(zone, NR_MLOCK)),
3294 K(zone_page_state(zone, NR_FILE_DIRTY)),
3295 K(zone_page_state(zone, NR_WRITEBACK)),
3296 K(zone_page_state(zone, NR_FILE_MAPPED)),
3297 K(zone_page_state(zone, NR_SHMEM)),
3298 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3299 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3300 zone_page_state(zone, NR_KERNEL_STACK) *
3302 K(zone_page_state(zone, NR_PAGETABLE)),
3303 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3304 K(zone_page_state(zone, NR_BOUNCE)),
3306 K(this_cpu_read(zone->pageset->pcp.count)),
3307 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3308 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3309 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3310 (!zone_reclaimable(zone) ? "yes" : "no")
3312 printk("lowmem_reserve[]:");
3313 for (i = 0; i < MAX_NR_ZONES; i++)
3314 printk(" %ld", zone->lowmem_reserve[i]);
3318 for_each_populated_zone(zone) {
3319 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3320 unsigned char types[MAX_ORDER];
3322 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3325 printk("%s: ", zone->name);
3327 spin_lock_irqsave(&zone->lock, flags);
3328 for (order = 0; order < MAX_ORDER; order++) {
3329 struct free_area *area = &zone->free_area[order];
3332 nr[order] = area->nr_free;
3333 total += nr[order] << order;
3336 for (type = 0; type < MIGRATE_TYPES; type++) {
3337 if (!list_empty(&area->free_list[type]))
3338 types[order] |= 1 << type;
3341 spin_unlock_irqrestore(&zone->lock, flags);
3342 for (order = 0; order < MAX_ORDER; order++) {
3343 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3345 show_migration_types(types[order]);
3347 printk("= %lukB\n", K(total));
3350 hugetlb_show_meminfo();
3352 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3354 show_swap_cache_info();
3357 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3359 zoneref->zone = zone;
3360 zoneref->zone_idx = zone_idx(zone);
3364 * Builds allocation fallback zone lists.
3366 * Add all populated zones of a node to the zonelist.
3368 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3372 enum zone_type zone_type = MAX_NR_ZONES;
3376 zone = pgdat->node_zones + zone_type;
3377 if (populated_zone(zone)) {
3378 zoneref_set_zone(zone,
3379 &zonelist->_zonerefs[nr_zones++]);
3380 check_highest_zone(zone_type);
3382 } while (zone_type);
3390 * 0 = automatic detection of better ordering.
3391 * 1 = order by ([node] distance, -zonetype)
3392 * 2 = order by (-zonetype, [node] distance)
3394 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3395 * the same zonelist. So only NUMA can configure this param.
3397 #define ZONELIST_ORDER_DEFAULT 0
3398 #define ZONELIST_ORDER_NODE 1
3399 #define ZONELIST_ORDER_ZONE 2
3401 /* zonelist order in the kernel.
3402 * set_zonelist_order() will set this to NODE or ZONE.
3404 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3405 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3409 /* The value user specified ....changed by config */
3410 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3411 /* string for sysctl */
3412 #define NUMA_ZONELIST_ORDER_LEN 16
3413 char numa_zonelist_order[16] = "default";
3416 * interface for configure zonelist ordering.
3417 * command line option "numa_zonelist_order"
3418 * = "[dD]efault - default, automatic configuration.
3419 * = "[nN]ode - order by node locality, then by zone within node
3420 * = "[zZ]one - order by zone, then by locality within zone
3423 static int __parse_numa_zonelist_order(char *s)
3425 if (*s == 'd' || *s == 'D') {
3426 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3427 } else if (*s == 'n' || *s == 'N') {
3428 user_zonelist_order = ZONELIST_ORDER_NODE;
3429 } else if (*s == 'z' || *s == 'Z') {
3430 user_zonelist_order = ZONELIST_ORDER_ZONE;
3433 "Ignoring invalid numa_zonelist_order value: "
3440 static __init int setup_numa_zonelist_order(char *s)
3447 ret = __parse_numa_zonelist_order(s);
3449 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3453 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3456 * sysctl handler for numa_zonelist_order
3458 int numa_zonelist_order_handler(struct ctl_table *table, int write,
3459 void __user *buffer, size_t *length,
3462 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3464 static DEFINE_MUTEX(zl_order_mutex);
3466 mutex_lock(&zl_order_mutex);
3468 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3472 strcpy(saved_string, (char *)table->data);
3474 ret = proc_dostring(table, write, buffer, length, ppos);
3478 int oldval = user_zonelist_order;
3480 ret = __parse_numa_zonelist_order((char *)table->data);
3483 * bogus value. restore saved string
3485 strncpy((char *)table->data, saved_string,
3486 NUMA_ZONELIST_ORDER_LEN);
3487 user_zonelist_order = oldval;
3488 } else if (oldval != user_zonelist_order) {
3489 mutex_lock(&zonelists_mutex);
3490 build_all_zonelists(NULL, NULL);
3491 mutex_unlock(&zonelists_mutex);
3495 mutex_unlock(&zl_order_mutex);
3500 #define MAX_NODE_LOAD (nr_online_nodes)
3501 static int node_load[MAX_NUMNODES];
3504 * find_next_best_node - find the next node that should appear in a given node's fallback list
3505 * @node: node whose fallback list we're appending
3506 * @used_node_mask: nodemask_t of already used nodes
3508 * We use a number of factors to determine which is the next node that should
3509 * appear on a given node's fallback list. The node should not have appeared
3510 * already in @node's fallback list, and it should be the next closest node
3511 * according to the distance array (which contains arbitrary distance values
3512 * from each node to each node in the system), and should also prefer nodes
3513 * with no CPUs, since presumably they'll have very little allocation pressure
3514 * on them otherwise.
3515 * It returns -1 if no node is found.
3517 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3520 int min_val = INT_MAX;
3521 int best_node = NUMA_NO_NODE;
3522 const struct cpumask *tmp = cpumask_of_node(0);
3524 /* Use the local node if we haven't already */
3525 if (!node_isset(node, *used_node_mask)) {
3526 node_set(node, *used_node_mask);
3530 for_each_node_state(n, N_MEMORY) {
3532 /* Don't want a node to appear more than once */
3533 if (node_isset(n, *used_node_mask))
3536 /* Use the distance array to find the distance */
3537 val = node_distance(node, n);
3539 /* Penalize nodes under us ("prefer the next node") */
3542 /* Give preference to headless and unused nodes */
3543 tmp = cpumask_of_node(n);
3544 if (!cpumask_empty(tmp))
3545 val += PENALTY_FOR_NODE_WITH_CPUS;
3547 /* Slight preference for less loaded node */
3548 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3549 val += node_load[n];
3551 if (val < min_val) {
3558 node_set(best_node, *used_node_mask);
3565 * Build zonelists ordered by node and zones within node.
3566 * This results in maximum locality--normal zone overflows into local
3567 * DMA zone, if any--but risks exhausting DMA zone.
3569 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3572 struct zonelist *zonelist;
3574 zonelist = &pgdat->node_zonelists[0];
3575 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3577 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3578 zonelist->_zonerefs[j].zone = NULL;
3579 zonelist->_zonerefs[j].zone_idx = 0;
3583 * Build gfp_thisnode zonelists
3585 static void build_thisnode_zonelists(pg_data_t *pgdat)
3588 struct zonelist *zonelist;
3590 zonelist = &pgdat->node_zonelists[1];
3591 j = build_zonelists_node(pgdat, zonelist, 0);
3592 zonelist->_zonerefs[j].zone = NULL;
3593 zonelist->_zonerefs[j].zone_idx = 0;
3597 * Build zonelists ordered by zone and nodes within zones.
3598 * This results in conserving DMA zone[s] until all Normal memory is
3599 * exhausted, but results in overflowing to remote node while memory
3600 * may still exist in local DMA zone.
3602 static int node_order[MAX_NUMNODES];
3604 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3607 int zone_type; /* needs to be signed */
3609 struct zonelist *zonelist;
3611 zonelist = &pgdat->node_zonelists[0];
3613 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3614 for (j = 0; j < nr_nodes; j++) {
3615 node = node_order[j];
3616 z = &NODE_DATA(node)->node_zones[zone_type];
3617 if (populated_zone(z)) {
3619 &zonelist->_zonerefs[pos++]);
3620 check_highest_zone(zone_type);
3624 zonelist->_zonerefs[pos].zone = NULL;
3625 zonelist->_zonerefs[pos].zone_idx = 0;
3628 #if defined(CONFIG_64BIT)
3630 * Devices that require DMA32/DMA are relatively rare and do not justify a
3631 * penalty to every machine in case the specialised case applies. Default
3632 * to Node-ordering on 64-bit NUMA machines
3634 static int default_zonelist_order(void)
3636 return ZONELIST_ORDER_NODE;
3640 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
3641 * by the kernel. If processes running on node 0 deplete the low memory zone
3642 * then reclaim will occur more frequency increasing stalls and potentially
3643 * be easier to OOM if a large percentage of the zone is under writeback or
3644 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
3645 * Hence, default to zone ordering on 32-bit.
3647 static int default_zonelist_order(void)
3649 return ZONELIST_ORDER_ZONE;
3651 #endif /* CONFIG_64BIT */
3653 static void set_zonelist_order(void)
3655 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3656 current_zonelist_order = default_zonelist_order();
3658 current_zonelist_order = user_zonelist_order;
3661 static void build_zonelists(pg_data_t *pgdat)
3665 nodemask_t used_mask;
3666 int local_node, prev_node;
3667 struct zonelist *zonelist;
3668 int order = current_zonelist_order;
3670 /* initialize zonelists */
3671 for (i = 0; i < MAX_ZONELISTS; i++) {
3672 zonelist = pgdat->node_zonelists + i;
3673 zonelist->_zonerefs[0].zone = NULL;
3674 zonelist->_zonerefs[0].zone_idx = 0;
3677 /* NUMA-aware ordering of nodes */
3678 local_node = pgdat->node_id;
3679 load = nr_online_nodes;
3680 prev_node = local_node;
3681 nodes_clear(used_mask);
3683 memset(node_order, 0, sizeof(node_order));
3686 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3688 * We don't want to pressure a particular node.
3689 * So adding penalty to the first node in same
3690 * distance group to make it round-robin.
3692 if (node_distance(local_node, node) !=
3693 node_distance(local_node, prev_node))
3694 node_load[node] = load;
3698 if (order == ZONELIST_ORDER_NODE)
3699 build_zonelists_in_node_order(pgdat, node);
3701 node_order[j++] = node; /* remember order */
3704 if (order == ZONELIST_ORDER_ZONE) {
3705 /* calculate node order -- i.e., DMA last! */
3706 build_zonelists_in_zone_order(pgdat, j);
3709 build_thisnode_zonelists(pgdat);
3712 /* Construct the zonelist performance cache - see further mmzone.h */
3713 static void build_zonelist_cache(pg_data_t *pgdat)
3715 struct zonelist *zonelist;
3716 struct zonelist_cache *zlc;
3719 zonelist = &pgdat->node_zonelists[0];
3720 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3721 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3722 for (z = zonelist->_zonerefs; z->zone; z++)
3723 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3726 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3728 * Return node id of node used for "local" allocations.
3729 * I.e., first node id of first zone in arg node's generic zonelist.
3730 * Used for initializing percpu 'numa_mem', which is used primarily
3731 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3733 int local_memory_node(int node)
3737 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3738 gfp_zone(GFP_KERNEL),
3745 #else /* CONFIG_NUMA */
3747 static void set_zonelist_order(void)
3749 current_zonelist_order = ZONELIST_ORDER_ZONE;
3752 static void build_zonelists(pg_data_t *pgdat)
3754 int node, local_node;
3756 struct zonelist *zonelist;
3758 local_node = pgdat->node_id;
3760 zonelist = &pgdat->node_zonelists[0];
3761 j = build_zonelists_node(pgdat, zonelist, 0);
3764 * Now we build the zonelist so that it contains the zones
3765 * of all the other nodes.
3766 * We don't want to pressure a particular node, so when
3767 * building the zones for node N, we make sure that the
3768 * zones coming right after the local ones are those from
3769 * node N+1 (modulo N)
3771 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3772 if (!node_online(node))
3774 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3776 for (node = 0; node < local_node; node++) {
3777 if (!node_online(node))
3779 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3782 zonelist->_zonerefs[j].zone = NULL;
3783 zonelist->_zonerefs[j].zone_idx = 0;
3786 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3787 static void build_zonelist_cache(pg_data_t *pgdat)
3789 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3792 #endif /* CONFIG_NUMA */
3795 * Boot pageset table. One per cpu which is going to be used for all
3796 * zones and all nodes. The parameters will be set in such a way
3797 * that an item put on a list will immediately be handed over to
3798 * the buddy list. This is safe since pageset manipulation is done
3799 * with interrupts disabled.
3801 * The boot_pagesets must be kept even after bootup is complete for
3802 * unused processors and/or zones. They do play a role for bootstrapping
3803 * hotplugged processors.
3805 * zoneinfo_show() and maybe other functions do
3806 * not check if the processor is online before following the pageset pointer.
3807 * Other parts of the kernel may not check if the zone is available.
3809 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3810 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3811 static void setup_zone_pageset(struct zone *zone);
3814 * Global mutex to protect against size modification of zonelists
3815 * as well as to serialize pageset setup for the new populated zone.
3817 DEFINE_MUTEX(zonelists_mutex);
3819 /* return values int ....just for stop_machine() */
3820 static int __build_all_zonelists(void *data)
3824 pg_data_t *self = data;
3827 memset(node_load, 0, sizeof(node_load));
3830 if (self && !node_online(self->node_id)) {
3831 build_zonelists(self);
3832 build_zonelist_cache(self);
3835 for_each_online_node(nid) {
3836 pg_data_t *pgdat = NODE_DATA(nid);
3838 build_zonelists(pgdat);
3839 build_zonelist_cache(pgdat);
3843 * Initialize the boot_pagesets that are going to be used
3844 * for bootstrapping processors. The real pagesets for
3845 * each zone will be allocated later when the per cpu
3846 * allocator is available.
3848 * boot_pagesets are used also for bootstrapping offline
3849 * cpus if the system is already booted because the pagesets
3850 * are needed to initialize allocators on a specific cpu too.
3851 * F.e. the percpu allocator needs the page allocator which
3852 * needs the percpu allocator in order to allocate its pagesets
3853 * (a chicken-egg dilemma).
3855 for_each_possible_cpu(cpu) {
3856 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3858 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3860 * We now know the "local memory node" for each node--
3861 * i.e., the node of the first zone in the generic zonelist.
3862 * Set up numa_mem percpu variable for on-line cpus. During
3863 * boot, only the boot cpu should be on-line; we'll init the
3864 * secondary cpus' numa_mem as they come on-line. During
3865 * node/memory hotplug, we'll fixup all on-line cpus.
3867 if (cpu_online(cpu))
3868 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3875 static noinline void __init
3876 build_all_zonelists_init(void)
3878 __build_all_zonelists(NULL);
3879 mminit_verify_zonelist();
3880 cpuset_init_current_mems_allowed();
3884 * Called with zonelists_mutex held always
3885 * unless system_state == SYSTEM_BOOTING.
3887 * __ref due to (1) call of __meminit annotated setup_zone_pageset
3888 * [we're only called with non-NULL zone through __meminit paths] and
3889 * (2) call of __init annotated helper build_all_zonelists_init
3890 * [protected by SYSTEM_BOOTING].
3892 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3894 set_zonelist_order();
3896 if (system_state == SYSTEM_BOOTING) {
3897 build_all_zonelists_init();
3899 #ifdef CONFIG_MEMORY_HOTPLUG
3901 setup_zone_pageset(zone);
3903 /* we have to stop all cpus to guarantee there is no user
3905 stop_machine(__build_all_zonelists, pgdat, NULL);
3906 /* cpuset refresh routine should be here */
3908 vm_total_pages = nr_free_pagecache_pages();
3910 * Disable grouping by mobility if the number of pages in the
3911 * system is too low to allow the mechanism to work. It would be
3912 * more accurate, but expensive to check per-zone. This check is
3913 * made on memory-hotadd so a system can start with mobility
3914 * disabled and enable it later
3916 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3917 page_group_by_mobility_disabled = 1;
3919 page_group_by_mobility_disabled = 0;
3921 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
3922 "Total pages: %ld\n",
3924 zonelist_order_name[current_zonelist_order],
3925 page_group_by_mobility_disabled ? "off" : "on",
3928 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
3933 * Helper functions to size the waitqueue hash table.
3934 * Essentially these want to choose hash table sizes sufficiently
3935 * large so that collisions trying to wait on pages are rare.
3936 * But in fact, the number of active page waitqueues on typical
3937 * systems is ridiculously low, less than 200. So this is even
3938 * conservative, even though it seems large.
3940 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3941 * waitqueues, i.e. the size of the waitq table given the number of pages.
3943 #define PAGES_PER_WAITQUEUE 256
3945 #ifndef CONFIG_MEMORY_HOTPLUG
3946 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3948 unsigned long size = 1;
3950 pages /= PAGES_PER_WAITQUEUE;
3952 while (size < pages)
3956 * Once we have dozens or even hundreds of threads sleeping
3957 * on IO we've got bigger problems than wait queue collision.
3958 * Limit the size of the wait table to a reasonable size.
3960 size = min(size, 4096UL);
3962 return max(size, 4UL);
3966 * A zone's size might be changed by hot-add, so it is not possible to determine
3967 * a suitable size for its wait_table. So we use the maximum size now.
3969 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3971 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3972 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3973 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3975 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3976 * or more by the traditional way. (See above). It equals:
3978 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3979 * ia64(16K page size) : = ( 8G + 4M)byte.
3980 * powerpc (64K page size) : = (32G +16M)byte.
3982 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3989 * This is an integer logarithm so that shifts can be used later
3990 * to extract the more random high bits from the multiplicative
3991 * hash function before the remainder is taken.
3993 static inline unsigned long wait_table_bits(unsigned long size)
3999 * Check if a pageblock contains reserved pages
4001 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
4005 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4006 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
4013 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
4014 * of blocks reserved is based on min_wmark_pages(zone). The memory within
4015 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
4016 * higher will lead to a bigger reserve which will get freed as contiguous
4017 * blocks as reclaim kicks in
4019 static void setup_zone_migrate_reserve(struct zone *zone)
4021 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
4023 unsigned long block_migratetype;
4028 * Get the start pfn, end pfn and the number of blocks to reserve
4029 * We have to be careful to be aligned to pageblock_nr_pages to
4030 * make sure that we always check pfn_valid for the first page in
4033 start_pfn = zone->zone_start_pfn;
4034 end_pfn = zone_end_pfn(zone);
4035 start_pfn = roundup(start_pfn, pageblock_nr_pages);
4036 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
4040 * Reserve blocks are generally in place to help high-order atomic
4041 * allocations that are short-lived. A min_free_kbytes value that
4042 * would result in more than 2 reserve blocks for atomic allocations
4043 * is assumed to be in place to help anti-fragmentation for the
4044 * future allocation of hugepages at runtime.
4046 reserve = min(2, reserve);
4047 old_reserve = zone->nr_migrate_reserve_block;
4049 /* When memory hot-add, we almost always need to do nothing */
4050 if (reserve == old_reserve)
4052 zone->nr_migrate_reserve_block = reserve;
4054 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
4055 if (!pfn_valid(pfn))
4057 page = pfn_to_page(pfn);
4059 /* Watch out for overlapping nodes */
4060 if (page_to_nid(page) != zone_to_nid(zone))
4063 block_migratetype = get_pageblock_migratetype(page);
4065 /* Only test what is necessary when the reserves are not met */
4068 * Blocks with reserved pages will never free, skip
4071 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
4072 if (pageblock_is_reserved(pfn, block_end_pfn))
4075 /* If this block is reserved, account for it */
4076 if (block_migratetype == MIGRATE_RESERVE) {
4081 /* Suitable for reserving if this block is movable */
4082 if (block_migratetype == MIGRATE_MOVABLE) {
4083 set_pageblock_migratetype(page,
4085 move_freepages_block(zone, page,
4090 } else if (!old_reserve) {
4092 * At boot time we don't need to scan the whole zone
4093 * for turning off MIGRATE_RESERVE.
4099 * If the reserve is met and this is a previous reserved block,
4102 if (block_migratetype == MIGRATE_RESERVE) {
4103 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4104 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4110 * Initially all pages are reserved - free ones are freed
4111 * up by free_all_bootmem() once the early boot process is
4112 * done. Non-atomic initialization, single-pass.
4114 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4115 unsigned long start_pfn, enum memmap_context context)
4118 unsigned long end_pfn = start_pfn + size;
4122 if (highest_memmap_pfn < end_pfn - 1)
4123 highest_memmap_pfn = end_pfn - 1;
4125 z = &NODE_DATA(nid)->node_zones[zone];
4126 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4128 * There can be holes in boot-time mem_map[]s
4129 * handed to this function. They do not
4130 * exist on hotplugged memory.
4132 if (context == MEMMAP_EARLY) {
4133 if (!early_pfn_valid(pfn))
4135 if (!early_pfn_in_nid(pfn, nid))
4138 page = pfn_to_page(pfn);
4139 set_page_links(page, zone, nid, pfn);
4140 mminit_verify_page_links(page, zone, nid, pfn);
4141 init_page_count(page);
4142 page_mapcount_reset(page);
4143 page_cpupid_reset_last(page);
4144 SetPageReserved(page);
4146 * Mark the block movable so that blocks are reserved for
4147 * movable at startup. This will force kernel allocations
4148 * to reserve their blocks rather than leaking throughout
4149 * the address space during boot when many long-lived
4150 * kernel allocations are made. Later some blocks near
4151 * the start are marked MIGRATE_RESERVE by
4152 * setup_zone_migrate_reserve()
4154 * bitmap is created for zone's valid pfn range. but memmap
4155 * can be created for invalid pages (for alignment)
4156 * check here not to call set_pageblock_migratetype() against
4159 if ((z->zone_start_pfn <= pfn)
4160 && (pfn < zone_end_pfn(z))
4161 && !(pfn & (pageblock_nr_pages - 1)))
4162 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4164 INIT_LIST_HEAD(&page->lru);
4165 #ifdef WANT_PAGE_VIRTUAL
4166 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4167 if (!is_highmem_idx(zone))
4168 set_page_address(page, __va(pfn << PAGE_SHIFT));
4173 static void __meminit zone_init_free_lists(struct zone *zone)
4175 unsigned int order, t;
4176 for_each_migratetype_order(order, t) {
4177 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4178 zone->free_area[order].nr_free = 0;
4182 #ifndef __HAVE_ARCH_MEMMAP_INIT
4183 #define memmap_init(size, nid, zone, start_pfn) \
4184 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4187 static int zone_batchsize(struct zone *zone)
4193 * The per-cpu-pages pools are set to around 1000th of the
4194 * size of the zone. But no more than 1/2 of a meg.
4196 * OK, so we don't know how big the cache is. So guess.
4198 batch = zone->managed_pages / 1024;
4199 if (batch * PAGE_SIZE > 512 * 1024)
4200 batch = (512 * 1024) / PAGE_SIZE;
4201 batch /= 4; /* We effectively *= 4 below */
4206 * Clamp the batch to a 2^n - 1 value. Having a power
4207 * of 2 value was found to be more likely to have
4208 * suboptimal cache aliasing properties in some cases.
4210 * For example if 2 tasks are alternately allocating
4211 * batches of pages, one task can end up with a lot
4212 * of pages of one half of the possible page colors
4213 * and the other with pages of the other colors.
4215 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4220 /* The deferral and batching of frees should be suppressed under NOMMU
4223 * The problem is that NOMMU needs to be able to allocate large chunks
4224 * of contiguous memory as there's no hardware page translation to
4225 * assemble apparent contiguous memory from discontiguous pages.
4227 * Queueing large contiguous runs of pages for batching, however,
4228 * causes the pages to actually be freed in smaller chunks. As there
4229 * can be a significant delay between the individual batches being
4230 * recycled, this leads to the once large chunks of space being
4231 * fragmented and becoming unavailable for high-order allocations.
4238 * pcp->high and pcp->batch values are related and dependent on one another:
4239 * ->batch must never be higher then ->high.
4240 * The following function updates them in a safe manner without read side
4243 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4244 * those fields changing asynchronously (acording the the above rule).
4246 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4247 * outside of boot time (or some other assurance that no concurrent updaters
4250 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4251 unsigned long batch)
4253 /* start with a fail safe value for batch */
4257 /* Update high, then batch, in order */
4264 /* a companion to pageset_set_high() */
4265 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4267 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4270 static void pageset_init(struct per_cpu_pageset *p)
4272 struct per_cpu_pages *pcp;
4275 memset(p, 0, sizeof(*p));
4279 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4280 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4283 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4286 pageset_set_batch(p, batch);
4290 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4291 * to the value high for the pageset p.
4293 static void pageset_set_high(struct per_cpu_pageset *p,
4296 unsigned long batch = max(1UL, high / 4);
4297 if ((high / 4) > (PAGE_SHIFT * 8))
4298 batch = PAGE_SHIFT * 8;
4300 pageset_update(&p->pcp, high, batch);
4303 static void pageset_set_high_and_batch(struct zone *zone,
4304 struct per_cpu_pageset *pcp)
4306 if (percpu_pagelist_fraction)
4307 pageset_set_high(pcp,
4308 (zone->managed_pages /
4309 percpu_pagelist_fraction));
4311 pageset_set_batch(pcp, zone_batchsize(zone));
4314 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4316 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4319 pageset_set_high_and_batch(zone, pcp);
4322 static void __meminit setup_zone_pageset(struct zone *zone)
4325 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4326 for_each_possible_cpu(cpu)
4327 zone_pageset_init(zone, cpu);
4331 * Allocate per cpu pagesets and initialize them.
4332 * Before this call only boot pagesets were available.
4334 void __init setup_per_cpu_pageset(void)
4338 for_each_populated_zone(zone)
4339 setup_zone_pageset(zone);
4342 static noinline __init_refok
4343 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4349 * The per-page waitqueue mechanism uses hashed waitqueues
4352 zone->wait_table_hash_nr_entries =
4353 wait_table_hash_nr_entries(zone_size_pages);
4354 zone->wait_table_bits =
4355 wait_table_bits(zone->wait_table_hash_nr_entries);
4356 alloc_size = zone->wait_table_hash_nr_entries
4357 * sizeof(wait_queue_head_t);
4359 if (!slab_is_available()) {
4360 zone->wait_table = (wait_queue_head_t *)
4361 memblock_virt_alloc_node_nopanic(
4362 alloc_size, zone->zone_pgdat->node_id);
4365 * This case means that a zone whose size was 0 gets new memory
4366 * via memory hot-add.
4367 * But it may be the case that a new node was hot-added. In
4368 * this case vmalloc() will not be able to use this new node's
4369 * memory - this wait_table must be initialized to use this new
4370 * node itself as well.
4371 * To use this new node's memory, further consideration will be
4374 zone->wait_table = vmalloc(alloc_size);
4376 if (!zone->wait_table)
4379 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4380 init_waitqueue_head(zone->wait_table + i);
4385 static __meminit void zone_pcp_init(struct zone *zone)
4388 * per cpu subsystem is not up at this point. The following code
4389 * relies on the ability of the linker to provide the
4390 * offset of a (static) per cpu variable into the per cpu area.
4392 zone->pageset = &boot_pageset;
4394 if (populated_zone(zone))
4395 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4396 zone->name, zone->present_pages,
4397 zone_batchsize(zone));
4400 int __meminit init_currently_empty_zone(struct zone *zone,
4401 unsigned long zone_start_pfn,
4403 enum memmap_context context)
4405 struct pglist_data *pgdat = zone->zone_pgdat;
4407 ret = zone_wait_table_init(zone, size);
4410 pgdat->nr_zones = zone_idx(zone) + 1;
4412 zone->zone_start_pfn = zone_start_pfn;
4414 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4415 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4417 (unsigned long)zone_idx(zone),
4418 zone_start_pfn, (zone_start_pfn + size));
4420 zone_init_free_lists(zone);
4425 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4426 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4428 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4430 int __meminit __early_pfn_to_nid(unsigned long pfn)
4432 unsigned long start_pfn, end_pfn;
4435 * NOTE: The following SMP-unsafe globals are only used early in boot
4436 * when the kernel is running single-threaded.
4438 static unsigned long __meminitdata last_start_pfn, last_end_pfn;
4439 static int __meminitdata last_nid;
4441 if (last_start_pfn <= pfn && pfn < last_end_pfn)
4444 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4446 last_start_pfn = start_pfn;
4447 last_end_pfn = end_pfn;
4453 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4455 int __meminit early_pfn_to_nid(unsigned long pfn)
4459 nid = __early_pfn_to_nid(pfn);
4462 /* just returns 0 */
4466 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4467 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4471 nid = __early_pfn_to_nid(pfn);
4472 if (nid >= 0 && nid != node)
4479 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4480 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4481 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4483 * If an architecture guarantees that all ranges registered contain no holes
4484 * and may be freed, this this function may be used instead of calling
4485 * memblock_free_early_nid() manually.
4487 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4489 unsigned long start_pfn, end_pfn;
4492 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4493 start_pfn = min(start_pfn, max_low_pfn);
4494 end_pfn = min(end_pfn, max_low_pfn);
4496 if (start_pfn < end_pfn)
4497 memblock_free_early_nid(PFN_PHYS(start_pfn),
4498 (end_pfn - start_pfn) << PAGE_SHIFT,
4504 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4505 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4507 * If an architecture guarantees that all ranges registered contain no holes and may
4508 * be freed, this function may be used instead of calling memory_present() manually.
4510 void __init sparse_memory_present_with_active_regions(int nid)
4512 unsigned long start_pfn, end_pfn;
4515 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4516 memory_present(this_nid, start_pfn, end_pfn);
4520 * get_pfn_range_for_nid - Return the start and end page frames for a node
4521 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4522 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4523 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4525 * It returns the start and end page frame of a node based on information
4526 * provided by memblock_set_node(). If called for a node
4527 * with no available memory, a warning is printed and the start and end
4530 void __meminit get_pfn_range_for_nid(unsigned int nid,
4531 unsigned long *start_pfn, unsigned long *end_pfn)
4533 unsigned long this_start_pfn, this_end_pfn;
4539 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
4540 *start_pfn = min(*start_pfn, this_start_pfn);
4541 *end_pfn = max(*end_pfn, this_end_pfn);
4544 if (*start_pfn == -1UL)
4549 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4550 * assumption is made that zones within a node are ordered in monotonic
4551 * increasing memory addresses so that the "highest" populated zone is used
4553 static void __init find_usable_zone_for_movable(void)
4556 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4557 if (zone_index == ZONE_MOVABLE)
4560 if (arch_zone_highest_possible_pfn[zone_index] >
4561 arch_zone_lowest_possible_pfn[zone_index])
4565 VM_BUG_ON(zone_index == -1);
4566 movable_zone = zone_index;
4570 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4571 * because it is sized independent of architecture. Unlike the other zones,
4572 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4573 * in each node depending on the size of each node and how evenly kernelcore
4574 * is distributed. This helper function adjusts the zone ranges
4575 * provided by the architecture for a given node by using the end of the
4576 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4577 * zones within a node are in order of monotonic increases memory addresses
4579 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4580 unsigned long zone_type,
4581 unsigned long node_start_pfn,
4582 unsigned long node_end_pfn,
4583 unsigned long *zone_start_pfn,
4584 unsigned long *zone_end_pfn)
4586 /* Only adjust if ZONE_MOVABLE is on this node */
4587 if (zone_movable_pfn[nid]) {
4588 /* Size ZONE_MOVABLE */
4589 if (zone_type == ZONE_MOVABLE) {
4590 *zone_start_pfn = zone_movable_pfn[nid];
4591 *zone_end_pfn = min(node_end_pfn,
4592 arch_zone_highest_possible_pfn[movable_zone]);
4594 /* Adjust for ZONE_MOVABLE starting within this range */
4595 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4596 *zone_end_pfn > zone_movable_pfn[nid]) {
4597 *zone_end_pfn = zone_movable_pfn[nid];
4599 /* Check if this whole range is within ZONE_MOVABLE */
4600 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4601 *zone_start_pfn = *zone_end_pfn;
4606 * Return the number of pages a zone spans in a node, including holes
4607 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4609 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4610 unsigned long zone_type,
4611 unsigned long node_start_pfn,
4612 unsigned long node_end_pfn,
4613 unsigned long *ignored)
4615 unsigned long zone_start_pfn, zone_end_pfn;
4617 /* Get the start and end of the zone */
4618 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4619 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4620 adjust_zone_range_for_zone_movable(nid, zone_type,
4621 node_start_pfn, node_end_pfn,
4622 &zone_start_pfn, &zone_end_pfn);
4624 /* Check that this node has pages within the zone's required range */
4625 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4628 /* Move the zone boundaries inside the node if necessary */
4629 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4630 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4632 /* Return the spanned pages */
4633 return zone_end_pfn - zone_start_pfn;
4637 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4638 * then all holes in the requested range will be accounted for.
4640 unsigned long __meminit __absent_pages_in_range(int nid,
4641 unsigned long range_start_pfn,
4642 unsigned long range_end_pfn)
4644 unsigned long nr_absent = range_end_pfn - range_start_pfn;
4645 unsigned long start_pfn, end_pfn;
4648 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4649 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4650 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4651 nr_absent -= end_pfn - start_pfn;
4657 * absent_pages_in_range - Return number of page frames in holes within a range
4658 * @start_pfn: The start PFN to start searching for holes
4659 * @end_pfn: The end PFN to stop searching for holes
4661 * It returns the number of pages frames in memory holes within a range.
4663 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4664 unsigned long end_pfn)
4666 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4669 /* Return the number of page frames in holes in a zone on a node */
4670 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4671 unsigned long zone_type,
4672 unsigned long node_start_pfn,
4673 unsigned long node_end_pfn,
4674 unsigned long *ignored)
4676 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4677 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4678 unsigned long zone_start_pfn, zone_end_pfn;
4680 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4681 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4683 adjust_zone_range_for_zone_movable(nid, zone_type,
4684 node_start_pfn, node_end_pfn,
4685 &zone_start_pfn, &zone_end_pfn);
4686 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4689 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4690 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4691 unsigned long zone_type,
4692 unsigned long node_start_pfn,
4693 unsigned long node_end_pfn,
4694 unsigned long *zones_size)
4696 return zones_size[zone_type];
4699 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4700 unsigned long zone_type,
4701 unsigned long node_start_pfn,
4702 unsigned long node_end_pfn,
4703 unsigned long *zholes_size)
4708 return zholes_size[zone_type];
4711 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4713 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4714 unsigned long node_start_pfn,
4715 unsigned long node_end_pfn,
4716 unsigned long *zones_size,
4717 unsigned long *zholes_size)
4719 unsigned long realtotalpages = 0, totalpages = 0;
4722 for (i = 0; i < MAX_NR_ZONES; i++) {
4723 struct zone *zone = pgdat->node_zones + i;
4724 unsigned long size, real_size;
4726 size = zone_spanned_pages_in_node(pgdat->node_id, i,
4730 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
4731 node_start_pfn, node_end_pfn,
4733 zone->spanned_pages = size;
4734 zone->present_pages = real_size;
4737 realtotalpages += real_size;
4740 pgdat->node_spanned_pages = totalpages;
4741 pgdat->node_present_pages = realtotalpages;
4742 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4746 #ifndef CONFIG_SPARSEMEM
4748 * Calculate the size of the zone->blockflags rounded to an unsigned long
4749 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4750 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4751 * round what is now in bits to nearest long in bits, then return it in
4754 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4756 unsigned long usemapsize;
4758 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4759 usemapsize = roundup(zonesize, pageblock_nr_pages);
4760 usemapsize = usemapsize >> pageblock_order;
4761 usemapsize *= NR_PAGEBLOCK_BITS;
4762 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4764 return usemapsize / 8;
4767 static void __init setup_usemap(struct pglist_data *pgdat,
4769 unsigned long zone_start_pfn,
4770 unsigned long zonesize)
4772 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4773 zone->pageblock_flags = NULL;
4775 zone->pageblock_flags =
4776 memblock_virt_alloc_node_nopanic(usemapsize,
4780 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4781 unsigned long zone_start_pfn, unsigned long zonesize) {}
4782 #endif /* CONFIG_SPARSEMEM */
4784 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4786 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4787 void __paginginit set_pageblock_order(void)
4791 /* Check that pageblock_nr_pages has not already been setup */
4792 if (pageblock_order)
4795 if (HPAGE_SHIFT > PAGE_SHIFT)
4796 order = HUGETLB_PAGE_ORDER;
4798 order = MAX_ORDER - 1;
4801 * Assume the largest contiguous order of interest is a huge page.
4802 * This value may be variable depending on boot parameters on IA64 and
4805 pageblock_order = order;
4807 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4810 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4811 * is unused as pageblock_order is set at compile-time. See
4812 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4815 void __paginginit set_pageblock_order(void)
4819 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4821 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
4822 unsigned long present_pages)
4824 unsigned long pages = spanned_pages;
4827 * Provide a more accurate estimation if there are holes within
4828 * the zone and SPARSEMEM is in use. If there are holes within the
4829 * zone, each populated memory region may cost us one or two extra
4830 * memmap pages due to alignment because memmap pages for each
4831 * populated regions may not naturally algined on page boundary.
4832 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4834 if (spanned_pages > present_pages + (present_pages >> 4) &&
4835 IS_ENABLED(CONFIG_SPARSEMEM))
4836 pages = present_pages;
4838 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
4842 * Set up the zone data structures:
4843 * - mark all pages reserved
4844 * - mark all memory queues empty
4845 * - clear the memory bitmaps
4847 * NOTE: pgdat should get zeroed by caller.
4849 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4850 unsigned long node_start_pfn, unsigned long node_end_pfn)
4853 int nid = pgdat->node_id;
4854 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4857 pgdat_resize_init(pgdat);
4858 #ifdef CONFIG_NUMA_BALANCING
4859 spin_lock_init(&pgdat->numabalancing_migrate_lock);
4860 pgdat->numabalancing_migrate_nr_pages = 0;
4861 pgdat->numabalancing_migrate_next_window = jiffies;
4863 init_waitqueue_head(&pgdat->kswapd_wait);
4864 init_waitqueue_head(&pgdat->pfmemalloc_wait);
4865 pgdat_page_ext_init(pgdat);
4867 for (j = 0; j < MAX_NR_ZONES; j++) {
4868 struct zone *zone = pgdat->node_zones + j;
4869 unsigned long size, realsize, freesize, memmap_pages;
4871 size = zone->spanned_pages;
4872 realsize = freesize = zone->present_pages;
4875 * Adjust freesize so that it accounts for how much memory
4876 * is used by this zone for memmap. This affects the watermark
4877 * and per-cpu initialisations
4879 memmap_pages = calc_memmap_size(size, realsize);
4880 if (!is_highmem_idx(j)) {
4881 if (freesize >= memmap_pages) {
4882 freesize -= memmap_pages;
4885 " %s zone: %lu pages used for memmap\n",
4886 zone_names[j], memmap_pages);
4889 " %s zone: %lu pages exceeds freesize %lu\n",
4890 zone_names[j], memmap_pages, freesize);
4893 /* Account for reserved pages */
4894 if (j == 0 && freesize > dma_reserve) {
4895 freesize -= dma_reserve;
4896 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4897 zone_names[0], dma_reserve);
4900 if (!is_highmem_idx(j))
4901 nr_kernel_pages += freesize;
4902 /* Charge for highmem memmap if there are enough kernel pages */
4903 else if (nr_kernel_pages > memmap_pages * 2)
4904 nr_kernel_pages -= memmap_pages;
4905 nr_all_pages += freesize;
4908 * Set an approximate value for lowmem here, it will be adjusted
4909 * when the bootmem allocator frees pages into the buddy system.
4910 * And all highmem pages will be managed by the buddy system.
4912 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
4915 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4917 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4919 zone->name = zone_names[j];
4920 spin_lock_init(&zone->lock);
4921 spin_lock_init(&zone->lru_lock);
4922 zone_seqlock_init(zone);
4923 zone->zone_pgdat = pgdat;
4924 zone_pcp_init(zone);
4926 /* For bootup, initialized properly in watermark setup */
4927 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
4929 lruvec_init(&zone->lruvec);
4933 set_pageblock_order();
4934 setup_usemap(pgdat, zone, zone_start_pfn, size);
4935 ret = init_currently_empty_zone(zone, zone_start_pfn,
4936 size, MEMMAP_EARLY);
4938 memmap_init(size, nid, j, zone_start_pfn);
4939 zone_start_pfn += size;
4943 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4945 /* Skip empty nodes */
4946 if (!pgdat->node_spanned_pages)
4949 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4950 /* ia64 gets its own node_mem_map, before this, without bootmem */
4951 if (!pgdat->node_mem_map) {
4952 unsigned long size, start, end;
4956 * The zone's endpoints aren't required to be MAX_ORDER
4957 * aligned but the node_mem_map endpoints must be in order
4958 * for the buddy allocator to function correctly.
4960 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4961 end = pgdat_end_pfn(pgdat);
4962 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4963 size = (end - start) * sizeof(struct page);
4964 map = alloc_remap(pgdat->node_id, size);
4966 map = memblock_virt_alloc_node_nopanic(size,
4968 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4970 #ifndef CONFIG_NEED_MULTIPLE_NODES
4972 * With no DISCONTIG, the global mem_map is just set as node 0's
4974 if (pgdat == NODE_DATA(0)) {
4975 mem_map = NODE_DATA(0)->node_mem_map;
4976 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4977 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4978 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4979 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4982 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4985 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4986 unsigned long node_start_pfn, unsigned long *zholes_size)
4988 pg_data_t *pgdat = NODE_DATA(nid);
4989 unsigned long start_pfn = 0;
4990 unsigned long end_pfn = 0;
4992 /* pg_data_t should be reset to zero when it's allocated */
4993 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4995 pgdat->node_id = nid;
4996 pgdat->node_start_pfn = node_start_pfn;
4997 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4998 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
4999 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5000 (u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1);
5002 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5003 zones_size, zholes_size);
5005 alloc_node_mem_map(pgdat);
5006 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5007 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5008 nid, (unsigned long)pgdat,
5009 (unsigned long)pgdat->node_mem_map);
5012 free_area_init_core(pgdat, start_pfn, end_pfn);
5015 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5017 #if MAX_NUMNODES > 1
5019 * Figure out the number of possible node ids.
5021 void __init setup_nr_node_ids(void)
5024 unsigned int highest = 0;
5026 for_each_node_mask(node, node_possible_map)
5028 nr_node_ids = highest + 1;
5033 * node_map_pfn_alignment - determine the maximum internode alignment
5035 * This function should be called after node map is populated and sorted.
5036 * It calculates the maximum power of two alignment which can distinguish
5039 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5040 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5041 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5042 * shifted, 1GiB is enough and this function will indicate so.
5044 * This is used to test whether pfn -> nid mapping of the chosen memory
5045 * model has fine enough granularity to avoid incorrect mapping for the
5046 * populated node map.
5048 * Returns the determined alignment in pfn's. 0 if there is no alignment
5049 * requirement (single node).
5051 unsigned long __init node_map_pfn_alignment(void)
5053 unsigned long accl_mask = 0, last_end = 0;
5054 unsigned long start, end, mask;
5058 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5059 if (!start || last_nid < 0 || last_nid == nid) {
5066 * Start with a mask granular enough to pin-point to the
5067 * start pfn and tick off bits one-by-one until it becomes
5068 * too coarse to separate the current node from the last.
5070 mask = ~((1 << __ffs(start)) - 1);
5071 while (mask && last_end <= (start & (mask << 1)))
5074 /* accumulate all internode masks */
5078 /* convert mask to number of pages */
5079 return ~accl_mask + 1;
5082 /* Find the lowest pfn for a node */
5083 static unsigned long __init find_min_pfn_for_node(int nid)
5085 unsigned long min_pfn = ULONG_MAX;
5086 unsigned long start_pfn;
5089 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5090 min_pfn = min(min_pfn, start_pfn);
5092 if (min_pfn == ULONG_MAX) {
5094 "Could not find start_pfn for node %d\n", nid);
5102 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5104 * It returns the minimum PFN based on information provided via
5105 * memblock_set_node().
5107 unsigned long __init find_min_pfn_with_active_regions(void)
5109 return find_min_pfn_for_node(MAX_NUMNODES);
5113 * early_calculate_totalpages()
5114 * Sum pages in active regions for movable zone.
5115 * Populate N_MEMORY for calculating usable_nodes.
5117 static unsigned long __init early_calculate_totalpages(void)
5119 unsigned long totalpages = 0;
5120 unsigned long start_pfn, end_pfn;
5123 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5124 unsigned long pages = end_pfn - start_pfn;
5126 totalpages += pages;
5128 node_set_state(nid, N_MEMORY);
5134 * Find the PFN the Movable zone begins in each node. Kernel memory
5135 * is spread evenly between nodes as long as the nodes have enough
5136 * memory. When they don't, some nodes will have more kernelcore than
5139 static void __init find_zone_movable_pfns_for_nodes(void)
5142 unsigned long usable_startpfn;
5143 unsigned long kernelcore_node, kernelcore_remaining;
5144 /* save the state before borrow the nodemask */
5145 nodemask_t saved_node_state = node_states[N_MEMORY];
5146 unsigned long totalpages = early_calculate_totalpages();
5147 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5148 struct memblock_region *r;
5150 /* Need to find movable_zone earlier when movable_node is specified. */
5151 find_usable_zone_for_movable();
5154 * If movable_node is specified, ignore kernelcore and movablecore
5157 if (movable_node_is_enabled()) {
5158 for_each_memblock(memory, r) {
5159 if (!memblock_is_hotpluggable(r))
5164 usable_startpfn = PFN_DOWN(r->base);
5165 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5166 min(usable_startpfn, zone_movable_pfn[nid]) :
5174 * If movablecore=nn[KMG] was specified, calculate what size of
5175 * kernelcore that corresponds so that memory usable for
5176 * any allocation type is evenly spread. If both kernelcore
5177 * and movablecore are specified, then the value of kernelcore
5178 * will be used for required_kernelcore if it's greater than
5179 * what movablecore would have allowed.
5181 if (required_movablecore) {
5182 unsigned long corepages;
5185 * Round-up so that ZONE_MOVABLE is at least as large as what
5186 * was requested by the user
5188 required_movablecore =
5189 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5190 corepages = totalpages - required_movablecore;
5192 required_kernelcore = max(required_kernelcore, corepages);
5195 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5196 if (!required_kernelcore)
5199 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5200 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5203 /* Spread kernelcore memory as evenly as possible throughout nodes */
5204 kernelcore_node = required_kernelcore / usable_nodes;
5205 for_each_node_state(nid, N_MEMORY) {
5206 unsigned long start_pfn, end_pfn;
5209 * Recalculate kernelcore_node if the division per node
5210 * now exceeds what is necessary to satisfy the requested
5211 * amount of memory for the kernel
5213 if (required_kernelcore < kernelcore_node)
5214 kernelcore_node = required_kernelcore / usable_nodes;
5217 * As the map is walked, we track how much memory is usable
5218 * by the kernel using kernelcore_remaining. When it is
5219 * 0, the rest of the node is usable by ZONE_MOVABLE
5221 kernelcore_remaining = kernelcore_node;
5223 /* Go through each range of PFNs within this node */
5224 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5225 unsigned long size_pages;
5227 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5228 if (start_pfn >= end_pfn)
5231 /* Account for what is only usable for kernelcore */
5232 if (start_pfn < usable_startpfn) {
5233 unsigned long kernel_pages;
5234 kernel_pages = min(end_pfn, usable_startpfn)
5237 kernelcore_remaining -= min(kernel_pages,
5238 kernelcore_remaining);
5239 required_kernelcore -= min(kernel_pages,
5240 required_kernelcore);
5242 /* Continue if range is now fully accounted */
5243 if (end_pfn <= usable_startpfn) {
5246 * Push zone_movable_pfn to the end so
5247 * that if we have to rebalance
5248 * kernelcore across nodes, we will
5249 * not double account here
5251 zone_movable_pfn[nid] = end_pfn;
5254 start_pfn = usable_startpfn;
5258 * The usable PFN range for ZONE_MOVABLE is from
5259 * start_pfn->end_pfn. Calculate size_pages as the
5260 * number of pages used as kernelcore
5262 size_pages = end_pfn - start_pfn;
5263 if (size_pages > kernelcore_remaining)
5264 size_pages = kernelcore_remaining;
5265 zone_movable_pfn[nid] = start_pfn + size_pages;
5268 * Some kernelcore has been met, update counts and
5269 * break if the kernelcore for this node has been
5272 required_kernelcore -= min(required_kernelcore,
5274 kernelcore_remaining -= size_pages;
5275 if (!kernelcore_remaining)
5281 * If there is still required_kernelcore, we do another pass with one
5282 * less node in the count. This will push zone_movable_pfn[nid] further
5283 * along on the nodes that still have memory until kernelcore is
5287 if (usable_nodes && required_kernelcore > usable_nodes)
5291 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5292 for (nid = 0; nid < MAX_NUMNODES; nid++)
5293 zone_movable_pfn[nid] =
5294 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5297 /* restore the node_state */
5298 node_states[N_MEMORY] = saved_node_state;
5301 /* Any regular or high memory on that node ? */
5302 static void check_for_memory(pg_data_t *pgdat, int nid)
5304 enum zone_type zone_type;
5306 if (N_MEMORY == N_NORMAL_MEMORY)
5309 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5310 struct zone *zone = &pgdat->node_zones[zone_type];
5311 if (populated_zone(zone)) {
5312 node_set_state(nid, N_HIGH_MEMORY);
5313 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5314 zone_type <= ZONE_NORMAL)
5315 node_set_state(nid, N_NORMAL_MEMORY);
5322 * free_area_init_nodes - Initialise all pg_data_t and zone data
5323 * @max_zone_pfn: an array of max PFNs for each zone
5325 * This will call free_area_init_node() for each active node in the system.
5326 * Using the page ranges provided by memblock_set_node(), the size of each
5327 * zone in each node and their holes is calculated. If the maximum PFN
5328 * between two adjacent zones match, it is assumed that the zone is empty.
5329 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5330 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5331 * starts where the previous one ended. For example, ZONE_DMA32 starts
5332 * at arch_max_dma_pfn.
5334 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5336 unsigned long start_pfn, end_pfn;
5339 /* Record where the zone boundaries are */
5340 memset(arch_zone_lowest_possible_pfn, 0,
5341 sizeof(arch_zone_lowest_possible_pfn));
5342 memset(arch_zone_highest_possible_pfn, 0,
5343 sizeof(arch_zone_highest_possible_pfn));
5344 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5345 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5346 for (i = 1; i < MAX_NR_ZONES; i++) {
5347 if (i == ZONE_MOVABLE)
5349 arch_zone_lowest_possible_pfn[i] =
5350 arch_zone_highest_possible_pfn[i-1];
5351 arch_zone_highest_possible_pfn[i] =
5352 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5354 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5355 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5357 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5358 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5359 find_zone_movable_pfns_for_nodes();
5361 /* Print out the zone ranges */
5362 pr_info("Zone ranges:\n");
5363 for (i = 0; i < MAX_NR_ZONES; i++) {
5364 if (i == ZONE_MOVABLE)
5366 pr_info(" %-8s ", zone_names[i]);
5367 if (arch_zone_lowest_possible_pfn[i] ==
5368 arch_zone_highest_possible_pfn[i])
5371 pr_cont("[mem %#018Lx-%#018Lx]\n",
5372 (u64)arch_zone_lowest_possible_pfn[i]
5374 ((u64)arch_zone_highest_possible_pfn[i]
5375 << PAGE_SHIFT) - 1);
5378 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5379 pr_info("Movable zone start for each node\n");
5380 for (i = 0; i < MAX_NUMNODES; i++) {
5381 if (zone_movable_pfn[i])
5382 pr_info(" Node %d: %#018Lx\n", i,
5383 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
5386 /* Print out the early node map */
5387 pr_info("Early memory node ranges\n");
5388 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5389 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
5390 (u64)start_pfn << PAGE_SHIFT,
5391 ((u64)end_pfn << PAGE_SHIFT) - 1);
5393 /* Initialise every node */
5394 mminit_verify_pageflags_layout();
5395 setup_nr_node_ids();
5396 for_each_online_node(nid) {
5397 pg_data_t *pgdat = NODE_DATA(nid);
5398 free_area_init_node(nid, NULL,
5399 find_min_pfn_for_node(nid), NULL);
5401 /* Any memory on that node */
5402 if (pgdat->node_present_pages)
5403 node_set_state(nid, N_MEMORY);
5404 check_for_memory(pgdat, nid);
5408 static int __init cmdline_parse_core(char *p, unsigned long *core)
5410 unsigned long long coremem;
5414 coremem = memparse(p, &p);
5415 *core = coremem >> PAGE_SHIFT;
5417 /* Paranoid check that UL is enough for the coremem value */
5418 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5424 * kernelcore=size sets the amount of memory for use for allocations that
5425 * cannot be reclaimed or migrated.
5427 static int __init cmdline_parse_kernelcore(char *p)
5429 return cmdline_parse_core(p, &required_kernelcore);
5433 * movablecore=size sets the amount of memory for use for allocations that
5434 * can be reclaimed or migrated.
5436 static int __init cmdline_parse_movablecore(char *p)
5438 return cmdline_parse_core(p, &required_movablecore);
5441 early_param("kernelcore", cmdline_parse_kernelcore);
5442 early_param("movablecore", cmdline_parse_movablecore);
5444 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5446 void adjust_managed_page_count(struct page *page, long count)
5448 spin_lock(&managed_page_count_lock);
5449 page_zone(page)->managed_pages += count;
5450 totalram_pages += count;
5451 #ifdef CONFIG_HIGHMEM
5452 if (PageHighMem(page))
5453 totalhigh_pages += count;
5455 spin_unlock(&managed_page_count_lock);
5457 EXPORT_SYMBOL(adjust_managed_page_count);
5459 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5462 unsigned long pages = 0;
5464 start = (void *)PAGE_ALIGN((unsigned long)start);
5465 end = (void *)((unsigned long)end & PAGE_MASK);
5466 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5467 if ((unsigned int)poison <= 0xFF)
5468 memset(pos, poison, PAGE_SIZE);
5469 free_reserved_page(virt_to_page(pos));
5473 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5474 s, pages << (PAGE_SHIFT - 10), start, end);
5478 EXPORT_SYMBOL(free_reserved_area);
5480 #ifdef CONFIG_HIGHMEM
5481 void free_highmem_page(struct page *page)
5483 __free_reserved_page(page);
5485 page_zone(page)->managed_pages++;
5491 void __init mem_init_print_info(const char *str)
5493 unsigned long physpages, codesize, datasize, rosize, bss_size;
5494 unsigned long init_code_size, init_data_size;
5496 physpages = get_num_physpages();
5497 codesize = _etext - _stext;
5498 datasize = _edata - _sdata;
5499 rosize = __end_rodata - __start_rodata;
5500 bss_size = __bss_stop - __bss_start;
5501 init_data_size = __init_end - __init_begin;
5502 init_code_size = _einittext - _sinittext;
5505 * Detect special cases and adjust section sizes accordingly:
5506 * 1) .init.* may be embedded into .data sections
5507 * 2) .init.text.* may be out of [__init_begin, __init_end],
5508 * please refer to arch/tile/kernel/vmlinux.lds.S.
5509 * 3) .rodata.* may be embedded into .text or .data sections.
5511 #define adj_init_size(start, end, size, pos, adj) \
5513 if (start <= pos && pos < end && size > adj) \
5517 adj_init_size(__init_begin, __init_end, init_data_size,
5518 _sinittext, init_code_size);
5519 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
5520 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
5521 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
5522 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
5524 #undef adj_init_size
5526 pr_info("Memory: %luK/%luK available "
5527 "(%luK kernel code, %luK rwdata, %luK rodata, "
5528 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5529 #ifdef CONFIG_HIGHMEM
5533 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
5534 codesize >> 10, datasize >> 10, rosize >> 10,
5535 (init_data_size + init_code_size) >> 10, bss_size >> 10,
5536 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10),
5537 totalcma_pages << (PAGE_SHIFT-10),
5538 #ifdef CONFIG_HIGHMEM
5539 totalhigh_pages << (PAGE_SHIFT-10),
5541 str ? ", " : "", str ? str : "");
5545 * set_dma_reserve - set the specified number of pages reserved in the first zone
5546 * @new_dma_reserve: The number of pages to mark reserved
5548 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5549 * In the DMA zone, a significant percentage may be consumed by kernel image
5550 * and other unfreeable allocations which can skew the watermarks badly. This
5551 * function may optionally be used to account for unfreeable pages in the
5552 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5553 * smaller per-cpu batchsize.
5555 void __init set_dma_reserve(unsigned long new_dma_reserve)
5557 dma_reserve = new_dma_reserve;
5560 void __init free_area_init(unsigned long *zones_size)
5562 free_area_init_node(0, zones_size,
5563 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5566 static int page_alloc_cpu_notify(struct notifier_block *self,
5567 unsigned long action, void *hcpu)
5569 int cpu = (unsigned long)hcpu;
5571 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5572 lru_add_drain_cpu(cpu);
5576 * Spill the event counters of the dead processor
5577 * into the current processors event counters.
5578 * This artificially elevates the count of the current
5581 vm_events_fold_cpu(cpu);
5584 * Zero the differential counters of the dead processor
5585 * so that the vm statistics are consistent.
5587 * This is only okay since the processor is dead and cannot
5588 * race with what we are doing.
5590 cpu_vm_stats_fold(cpu);
5595 void __init page_alloc_init(void)
5597 hotcpu_notifier(page_alloc_cpu_notify, 0);
5601 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5602 * or min_free_kbytes changes.
5604 static void calculate_totalreserve_pages(void)
5606 struct pglist_data *pgdat;
5607 unsigned long reserve_pages = 0;
5608 enum zone_type i, j;
5610 for_each_online_pgdat(pgdat) {
5611 for (i = 0; i < MAX_NR_ZONES; i++) {
5612 struct zone *zone = pgdat->node_zones + i;
5615 /* Find valid and maximum lowmem_reserve in the zone */
5616 for (j = i; j < MAX_NR_ZONES; j++) {
5617 if (zone->lowmem_reserve[j] > max)
5618 max = zone->lowmem_reserve[j];
5621 /* we treat the high watermark as reserved pages. */
5622 max += high_wmark_pages(zone);
5624 if (max > zone->managed_pages)
5625 max = zone->managed_pages;
5626 reserve_pages += max;
5628 * Lowmem reserves are not available to
5629 * GFP_HIGHUSER page cache allocations and
5630 * kswapd tries to balance zones to their high
5631 * watermark. As a result, neither should be
5632 * regarded as dirtyable memory, to prevent a
5633 * situation where reclaim has to clean pages
5634 * in order to balance the zones.
5636 zone->dirty_balance_reserve = max;
5639 dirty_balance_reserve = reserve_pages;
5640 totalreserve_pages = reserve_pages;
5644 * setup_per_zone_lowmem_reserve - called whenever
5645 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5646 * has a correct pages reserved value, so an adequate number of
5647 * pages are left in the zone after a successful __alloc_pages().
5649 static void setup_per_zone_lowmem_reserve(void)
5651 struct pglist_data *pgdat;
5652 enum zone_type j, idx;
5654 for_each_online_pgdat(pgdat) {
5655 for (j = 0; j < MAX_NR_ZONES; j++) {
5656 struct zone *zone = pgdat->node_zones + j;
5657 unsigned long managed_pages = zone->managed_pages;
5659 zone->lowmem_reserve[j] = 0;
5663 struct zone *lower_zone;
5667 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5668 sysctl_lowmem_reserve_ratio[idx] = 1;
5670 lower_zone = pgdat->node_zones + idx;
5671 lower_zone->lowmem_reserve[j] = managed_pages /
5672 sysctl_lowmem_reserve_ratio[idx];
5673 managed_pages += lower_zone->managed_pages;
5678 /* update totalreserve_pages */
5679 calculate_totalreserve_pages();
5682 static void __setup_per_zone_wmarks(void)
5684 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5685 unsigned long lowmem_pages = 0;
5687 unsigned long flags;
5689 /* Calculate total number of !ZONE_HIGHMEM pages */
5690 for_each_zone(zone) {
5691 if (!is_highmem(zone))
5692 lowmem_pages += zone->managed_pages;
5695 for_each_zone(zone) {
5698 spin_lock_irqsave(&zone->lock, flags);
5699 tmp = (u64)pages_min * zone->managed_pages;
5700 do_div(tmp, lowmem_pages);
5701 if (is_highmem(zone)) {
5703 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5704 * need highmem pages, so cap pages_min to a small
5707 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5708 * deltas control asynch page reclaim, and so should
5709 * not be capped for highmem.
5711 unsigned long min_pages;
5713 min_pages = zone->managed_pages / 1024;
5714 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
5715 zone->watermark[WMARK_MIN] = min_pages;
5718 * If it's a lowmem zone, reserve a number of pages
5719 * proportionate to the zone's size.
5721 zone->watermark[WMARK_MIN] = tmp;
5724 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5725 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5727 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
5728 high_wmark_pages(zone) - low_wmark_pages(zone) -
5729 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
5731 setup_zone_migrate_reserve(zone);
5732 spin_unlock_irqrestore(&zone->lock, flags);
5735 /* update totalreserve_pages */
5736 calculate_totalreserve_pages();
5740 * setup_per_zone_wmarks - called when min_free_kbytes changes
5741 * or when memory is hot-{added|removed}
5743 * Ensures that the watermark[min,low,high] values for each zone are set
5744 * correctly with respect to min_free_kbytes.
5746 void setup_per_zone_wmarks(void)
5748 mutex_lock(&zonelists_mutex);
5749 __setup_per_zone_wmarks();
5750 mutex_unlock(&zonelists_mutex);
5754 * The inactive anon list should be small enough that the VM never has to
5755 * do too much work, but large enough that each inactive page has a chance
5756 * to be referenced again before it is swapped out.
5758 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5759 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5760 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5761 * the anonymous pages are kept on the inactive list.
5764 * memory ratio inactive anon
5765 * -------------------------------------
5774 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5776 unsigned int gb, ratio;
5778 /* Zone size in gigabytes */
5779 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
5781 ratio = int_sqrt(10 * gb);
5785 zone->inactive_ratio = ratio;
5788 static void __meminit setup_per_zone_inactive_ratio(void)
5793 calculate_zone_inactive_ratio(zone);
5797 * Initialise min_free_kbytes.
5799 * For small machines we want it small (128k min). For large machines
5800 * we want it large (64MB max). But it is not linear, because network
5801 * bandwidth does not increase linearly with machine size. We use
5803 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5804 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5820 int __meminit init_per_zone_wmark_min(void)
5822 unsigned long lowmem_kbytes;
5823 int new_min_free_kbytes;
5825 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5826 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5828 if (new_min_free_kbytes > user_min_free_kbytes) {
5829 min_free_kbytes = new_min_free_kbytes;
5830 if (min_free_kbytes < 128)
5831 min_free_kbytes = 128;
5832 if (min_free_kbytes > 65536)
5833 min_free_kbytes = 65536;
5835 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5836 new_min_free_kbytes, user_min_free_kbytes);
5838 setup_per_zone_wmarks();
5839 refresh_zone_stat_thresholds();
5840 setup_per_zone_lowmem_reserve();
5841 setup_per_zone_inactive_ratio();
5844 module_init(init_per_zone_wmark_min)
5847 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5848 * that we can call two helper functions whenever min_free_kbytes
5851 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
5852 void __user *buffer, size_t *length, loff_t *ppos)
5856 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5861 user_min_free_kbytes = min_free_kbytes;
5862 setup_per_zone_wmarks();
5868 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
5869 void __user *buffer, size_t *length, loff_t *ppos)
5874 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5879 zone->min_unmapped_pages = (zone->managed_pages *
5880 sysctl_min_unmapped_ratio) / 100;
5884 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
5885 void __user *buffer, size_t *length, loff_t *ppos)
5890 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5895 zone->min_slab_pages = (zone->managed_pages *
5896 sysctl_min_slab_ratio) / 100;
5902 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5903 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5904 * whenever sysctl_lowmem_reserve_ratio changes.
5906 * The reserve ratio obviously has absolutely no relation with the
5907 * minimum watermarks. The lowmem reserve ratio can only make sense
5908 * if in function of the boot time zone sizes.
5910 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
5911 void __user *buffer, size_t *length, loff_t *ppos)
5913 proc_dointvec_minmax(table, write, buffer, length, ppos);
5914 setup_per_zone_lowmem_reserve();
5919 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5920 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5921 * pagelist can have before it gets flushed back to buddy allocator.
5923 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
5924 void __user *buffer, size_t *length, loff_t *ppos)
5927 int old_percpu_pagelist_fraction;
5930 mutex_lock(&pcp_batch_high_lock);
5931 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
5933 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5934 if (!write || ret < 0)
5937 /* Sanity checking to avoid pcp imbalance */
5938 if (percpu_pagelist_fraction &&
5939 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
5940 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
5946 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
5949 for_each_populated_zone(zone) {
5952 for_each_possible_cpu(cpu)
5953 pageset_set_high_and_batch(zone,
5954 per_cpu_ptr(zone->pageset, cpu));
5957 mutex_unlock(&pcp_batch_high_lock);
5962 int hashdist = HASHDIST_DEFAULT;
5964 static int __init set_hashdist(char *str)
5968 hashdist = simple_strtoul(str, &str, 0);
5971 __setup("hashdist=", set_hashdist);
5975 * allocate a large system hash table from bootmem
5976 * - it is assumed that the hash table must contain an exact power-of-2
5977 * quantity of entries
5978 * - limit is the number of hash buckets, not the total allocation size
5980 void *__init alloc_large_system_hash(const char *tablename,
5981 unsigned long bucketsize,
5982 unsigned long numentries,
5985 unsigned int *_hash_shift,
5986 unsigned int *_hash_mask,
5987 unsigned long low_limit,
5988 unsigned long high_limit)
5990 unsigned long long max = high_limit;
5991 unsigned long log2qty, size;
5994 /* allow the kernel cmdline to have a say */
5996 /* round applicable memory size up to nearest megabyte */
5997 numentries = nr_kernel_pages;
5999 /* It isn't necessary when PAGE_SIZE >= 1MB */
6000 if (PAGE_SHIFT < 20)
6001 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6003 /* limit to 1 bucket per 2^scale bytes of low memory */
6004 if (scale > PAGE_SHIFT)
6005 numentries >>= (scale - PAGE_SHIFT);
6007 numentries <<= (PAGE_SHIFT - scale);
6009 /* Make sure we've got at least a 0-order allocation.. */
6010 if (unlikely(flags & HASH_SMALL)) {
6011 /* Makes no sense without HASH_EARLY */
6012 WARN_ON(!(flags & HASH_EARLY));
6013 if (!(numentries >> *_hash_shift)) {
6014 numentries = 1UL << *_hash_shift;
6015 BUG_ON(!numentries);
6017 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6018 numentries = PAGE_SIZE / bucketsize;
6020 numentries = roundup_pow_of_two(numentries);
6022 /* limit allocation size to 1/16 total memory by default */
6024 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6025 do_div(max, bucketsize);
6027 max = min(max, 0x80000000ULL);
6029 if (numentries < low_limit)
6030 numentries = low_limit;
6031 if (numentries > max)
6034 log2qty = ilog2(numentries);
6037 size = bucketsize << log2qty;
6038 if (flags & HASH_EARLY)
6039 table = memblock_virt_alloc_nopanic(size, 0);
6041 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6044 * If bucketsize is not a power-of-two, we may free
6045 * some pages at the end of hash table which
6046 * alloc_pages_exact() automatically does
6048 if (get_order(size) < MAX_ORDER) {
6049 table = alloc_pages_exact(size, GFP_ATOMIC);
6050 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6053 } while (!table && size > PAGE_SIZE && --log2qty);
6056 panic("Failed to allocate %s hash table\n", tablename);
6058 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6061 ilog2(size) - PAGE_SHIFT,
6065 *_hash_shift = log2qty;
6067 *_hash_mask = (1 << log2qty) - 1;
6072 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6073 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6076 #ifdef CONFIG_SPARSEMEM
6077 return __pfn_to_section(pfn)->pageblock_flags;
6079 return zone->pageblock_flags;
6080 #endif /* CONFIG_SPARSEMEM */
6083 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6085 #ifdef CONFIG_SPARSEMEM
6086 pfn &= (PAGES_PER_SECTION-1);
6087 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6089 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6090 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6091 #endif /* CONFIG_SPARSEMEM */
6095 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6096 * @page: The page within the block of interest
6097 * @pfn: The target page frame number
6098 * @end_bitidx: The last bit of interest to retrieve
6099 * @mask: mask of bits that the caller is interested in
6101 * Return: pageblock_bits flags
6103 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6104 unsigned long end_bitidx,
6108 unsigned long *bitmap;
6109 unsigned long bitidx, word_bitidx;
6112 zone = page_zone(page);
6113 bitmap = get_pageblock_bitmap(zone, pfn);
6114 bitidx = pfn_to_bitidx(zone, pfn);
6115 word_bitidx = bitidx / BITS_PER_LONG;
6116 bitidx &= (BITS_PER_LONG-1);
6118 word = bitmap[word_bitidx];
6119 bitidx += end_bitidx;
6120 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6124 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6125 * @page: The page within the block of interest
6126 * @flags: The flags to set
6127 * @pfn: The target page frame number
6128 * @end_bitidx: The last bit of interest
6129 * @mask: mask of bits that the caller is interested in
6131 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6133 unsigned long end_bitidx,
6137 unsigned long *bitmap;
6138 unsigned long bitidx, word_bitidx;
6139 unsigned long old_word, word;
6141 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6143 zone = page_zone(page);
6144 bitmap = get_pageblock_bitmap(zone, pfn);
6145 bitidx = pfn_to_bitidx(zone, pfn);
6146 word_bitidx = bitidx / BITS_PER_LONG;
6147 bitidx &= (BITS_PER_LONG-1);
6149 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6151 bitidx += end_bitidx;
6152 mask <<= (BITS_PER_LONG - bitidx - 1);
6153 flags <<= (BITS_PER_LONG - bitidx - 1);
6155 word = READ_ONCE(bitmap[word_bitidx]);
6157 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6158 if (word == old_word)
6165 * This function checks whether pageblock includes unmovable pages or not.
6166 * If @count is not zero, it is okay to include less @count unmovable pages
6168 * PageLRU check without isolation or lru_lock could race so that
6169 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6170 * expect this function should be exact.
6172 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6173 bool skip_hwpoisoned_pages)
6175 unsigned long pfn, iter, found;
6179 * For avoiding noise data, lru_add_drain_all() should be called
6180 * If ZONE_MOVABLE, the zone never contains unmovable pages
6182 if (zone_idx(zone) == ZONE_MOVABLE)
6184 mt = get_pageblock_migratetype(page);
6185 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6188 pfn = page_to_pfn(page);
6189 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6190 unsigned long check = pfn + iter;
6192 if (!pfn_valid_within(check))
6195 page = pfn_to_page(check);
6198 * Hugepages are not in LRU lists, but they're movable.
6199 * We need not scan over tail pages bacause we don't
6200 * handle each tail page individually in migration.
6202 if (PageHuge(page)) {
6203 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6208 * We can't use page_count without pin a page
6209 * because another CPU can free compound page.
6210 * This check already skips compound tails of THP
6211 * because their page->_count is zero at all time.
6213 if (!atomic_read(&page->_count)) {
6214 if (PageBuddy(page))
6215 iter += (1 << page_order(page)) - 1;
6220 * The HWPoisoned page may be not in buddy system, and
6221 * page_count() is not 0.
6223 if (skip_hwpoisoned_pages && PageHWPoison(page))
6229 * If there are RECLAIMABLE pages, we need to check
6230 * it. But now, memory offline itself doesn't call
6231 * shrink_node_slabs() and it still to be fixed.
6234 * If the page is not RAM, page_count()should be 0.
6235 * we don't need more check. This is an _used_ not-movable page.
6237 * The problematic thing here is PG_reserved pages. PG_reserved
6238 * is set to both of a memory hole page and a _used_ kernel
6247 bool is_pageblock_removable_nolock(struct page *page)
6253 * We have to be careful here because we are iterating over memory
6254 * sections which are not zone aware so we might end up outside of
6255 * the zone but still within the section.
6256 * We have to take care about the node as well. If the node is offline
6257 * its NODE_DATA will be NULL - see page_zone.
6259 if (!node_online(page_to_nid(page)))
6262 zone = page_zone(page);
6263 pfn = page_to_pfn(page);
6264 if (!zone_spans_pfn(zone, pfn))
6267 return !has_unmovable_pages(zone, page, 0, true);
6272 static unsigned long pfn_max_align_down(unsigned long pfn)
6274 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6275 pageblock_nr_pages) - 1);
6278 static unsigned long pfn_max_align_up(unsigned long pfn)
6280 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6281 pageblock_nr_pages));
6284 /* [start, end) must belong to a single zone. */
6285 static int __alloc_contig_migrate_range(struct compact_control *cc,
6286 unsigned long start, unsigned long end)
6288 /* This function is based on compact_zone() from compaction.c. */
6289 unsigned long nr_reclaimed;
6290 unsigned long pfn = start;
6291 unsigned int tries = 0;
6296 while (pfn < end || !list_empty(&cc->migratepages)) {
6297 if (fatal_signal_pending(current)) {
6302 if (list_empty(&cc->migratepages)) {
6303 cc->nr_migratepages = 0;
6304 pfn = isolate_migratepages_range(cc, pfn, end);
6310 } else if (++tries == 5) {
6311 ret = ret < 0 ? ret : -EBUSY;
6315 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6317 cc->nr_migratepages -= nr_reclaimed;
6319 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6320 NULL, 0, cc->mode, MR_CMA);
6323 putback_movable_pages(&cc->migratepages);
6330 * alloc_contig_range() -- tries to allocate given range of pages
6331 * @start: start PFN to allocate
6332 * @end: one-past-the-last PFN to allocate
6333 * @migratetype: migratetype of the underlaying pageblocks (either
6334 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6335 * in range must have the same migratetype and it must
6336 * be either of the two.
6338 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6339 * aligned, however it's the caller's responsibility to guarantee that
6340 * we are the only thread that changes migrate type of pageblocks the
6343 * The PFN range must belong to a single zone.
6345 * Returns zero on success or negative error code. On success all
6346 * pages which PFN is in [start, end) are allocated for the caller and
6347 * need to be freed with free_contig_range().
6349 int alloc_contig_range(unsigned long start, unsigned long end,
6350 unsigned migratetype)
6352 unsigned long outer_start, outer_end;
6355 struct compact_control cc = {
6356 .nr_migratepages = 0,
6358 .zone = page_zone(pfn_to_page(start)),
6359 .mode = MIGRATE_SYNC,
6360 .ignore_skip_hint = true,
6362 INIT_LIST_HEAD(&cc.migratepages);
6365 * What we do here is we mark all pageblocks in range as
6366 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6367 * have different sizes, and due to the way page allocator
6368 * work, we align the range to biggest of the two pages so
6369 * that page allocator won't try to merge buddies from
6370 * different pageblocks and change MIGRATE_ISOLATE to some
6371 * other migration type.
6373 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6374 * migrate the pages from an unaligned range (ie. pages that
6375 * we are interested in). This will put all the pages in
6376 * range back to page allocator as MIGRATE_ISOLATE.
6378 * When this is done, we take the pages in range from page
6379 * allocator removing them from the buddy system. This way
6380 * page allocator will never consider using them.
6382 * This lets us mark the pageblocks back as
6383 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6384 * aligned range but not in the unaligned, original range are
6385 * put back to page allocator so that buddy can use them.
6388 ret = start_isolate_page_range(pfn_max_align_down(start),
6389 pfn_max_align_up(end), migratetype,
6394 ret = __alloc_contig_migrate_range(&cc, start, end);
6399 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6400 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6401 * more, all pages in [start, end) are free in page allocator.
6402 * What we are going to do is to allocate all pages from
6403 * [start, end) (that is remove them from page allocator).
6405 * The only problem is that pages at the beginning and at the
6406 * end of interesting range may be not aligned with pages that
6407 * page allocator holds, ie. they can be part of higher order
6408 * pages. Because of this, we reserve the bigger range and
6409 * once this is done free the pages we are not interested in.
6411 * We don't have to hold zone->lock here because the pages are
6412 * isolated thus they won't get removed from buddy.
6415 lru_add_drain_all();
6416 drain_all_pages(cc.zone);
6419 outer_start = start;
6420 while (!PageBuddy(pfn_to_page(outer_start))) {
6421 if (++order >= MAX_ORDER) {
6425 outer_start &= ~0UL << order;
6428 /* Make sure the range is really isolated. */
6429 if (test_pages_isolated(outer_start, end, false)) {
6430 pr_info("%s: [%lx, %lx) PFNs busy\n",
6431 __func__, outer_start, end);
6436 /* Grab isolated pages from freelists. */
6437 outer_end = isolate_freepages_range(&cc, outer_start, end);
6443 /* Free head and tail (if any) */
6444 if (start != outer_start)
6445 free_contig_range(outer_start, start - outer_start);
6446 if (end != outer_end)
6447 free_contig_range(end, outer_end - end);
6450 undo_isolate_page_range(pfn_max_align_down(start),
6451 pfn_max_align_up(end), migratetype);
6455 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6457 unsigned int count = 0;
6459 for (; nr_pages--; pfn++) {
6460 struct page *page = pfn_to_page(pfn);
6462 count += page_count(page) != 1;
6465 WARN(count != 0, "%d pages are still in use!\n", count);
6469 #ifdef CONFIG_MEMORY_HOTPLUG
6471 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6472 * page high values need to be recalulated.
6474 void __meminit zone_pcp_update(struct zone *zone)
6477 mutex_lock(&pcp_batch_high_lock);
6478 for_each_possible_cpu(cpu)
6479 pageset_set_high_and_batch(zone,
6480 per_cpu_ptr(zone->pageset, cpu));
6481 mutex_unlock(&pcp_batch_high_lock);
6485 void zone_pcp_reset(struct zone *zone)
6487 unsigned long flags;
6489 struct per_cpu_pageset *pset;
6491 /* avoid races with drain_pages() */
6492 local_irq_save(flags);
6493 if (zone->pageset != &boot_pageset) {
6494 for_each_online_cpu(cpu) {
6495 pset = per_cpu_ptr(zone->pageset, cpu);
6496 drain_zonestat(zone, pset);
6498 free_percpu(zone->pageset);
6499 zone->pageset = &boot_pageset;
6501 local_irq_restore(flags);
6504 #ifdef CONFIG_MEMORY_HOTREMOVE
6506 * All pages in the range must be isolated before calling this.
6509 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6513 unsigned int order, i;
6515 unsigned long flags;
6516 /* find the first valid pfn */
6517 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6522 zone = page_zone(pfn_to_page(pfn));
6523 spin_lock_irqsave(&zone->lock, flags);
6525 while (pfn < end_pfn) {
6526 if (!pfn_valid(pfn)) {
6530 page = pfn_to_page(pfn);
6532 * The HWPoisoned page may be not in buddy system, and
6533 * page_count() is not 0.
6535 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
6537 SetPageReserved(page);
6541 BUG_ON(page_count(page));
6542 BUG_ON(!PageBuddy(page));
6543 order = page_order(page);
6544 #ifdef CONFIG_DEBUG_VM
6545 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6546 pfn, 1 << order, end_pfn);
6548 list_del(&page->lru);
6549 rmv_page_order(page);
6550 zone->free_area[order].nr_free--;
6551 for (i = 0; i < (1 << order); i++)
6552 SetPageReserved((page+i));
6553 pfn += (1 << order);
6555 spin_unlock_irqrestore(&zone->lock, flags);
6559 #ifdef CONFIG_MEMORY_FAILURE
6560 bool is_free_buddy_page(struct page *page)
6562 struct zone *zone = page_zone(page);
6563 unsigned long pfn = page_to_pfn(page);
6564 unsigned long flags;
6567 spin_lock_irqsave(&zone->lock, flags);
6568 for (order = 0; order < MAX_ORDER; order++) {
6569 struct page *page_head = page - (pfn & ((1 << order) - 1));
6571 if (PageBuddy(page_head) && page_order(page_head) >= order)
6574 spin_unlock_irqrestore(&zone->lock, flags);
6576 return order < MAX_ORDER;