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/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/prefetch.h>
57 #include <linux/mm_inline.h>
58 #include <linux/migrate.h>
59 #include <linux/page-debug-flags.h>
60 #include <linux/hugetlb.h>
61 #include <linux/sched/rt.h>
63 #include <asm/sections.h>
64 #include <asm/tlbflush.h>
65 #include <asm/div64.h>
68 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
69 static DEFINE_MUTEX(pcp_batch_high_lock);
70 #define MIN_PERCPU_PAGELIST_FRACTION (8)
72 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
73 DEFINE_PER_CPU(int, numa_node);
74 EXPORT_PER_CPU_SYMBOL(numa_node);
77 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
79 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
80 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
81 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
82 * defined in <linux/topology.h>.
84 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
85 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
86 int _node_numa_mem_[MAX_NUMNODES];
90 * Array of node states.
92 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
93 [N_POSSIBLE] = NODE_MASK_ALL,
94 [N_ONLINE] = { { [0] = 1UL } },
96 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
98 [N_HIGH_MEMORY] = { { [0] = 1UL } },
100 #ifdef CONFIG_MOVABLE_NODE
101 [N_MEMORY] = { { [0] = 1UL } },
103 [N_CPU] = { { [0] = 1UL } },
106 EXPORT_SYMBOL(node_states);
108 /* Protect totalram_pages and zone->managed_pages */
109 static DEFINE_SPINLOCK(managed_page_count_lock);
111 unsigned long totalram_pages __read_mostly;
112 unsigned long totalreserve_pages __read_mostly;
114 * When calculating the number of globally allowed dirty pages, there
115 * is a certain number of per-zone reserves that should not be
116 * considered dirtyable memory. This is the sum of those reserves
117 * over all existing zones that contribute dirtyable memory.
119 unsigned long dirty_balance_reserve __read_mostly;
121 int percpu_pagelist_fraction;
122 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
124 #ifdef CONFIG_PM_SLEEP
126 * The following functions are used by the suspend/hibernate code to temporarily
127 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
128 * while devices are suspended. To avoid races with the suspend/hibernate code,
129 * they should always be called with pm_mutex held (gfp_allowed_mask also should
130 * only be modified with pm_mutex held, unless the suspend/hibernate code is
131 * guaranteed not to run in parallel with that modification).
134 static gfp_t saved_gfp_mask;
136 void pm_restore_gfp_mask(void)
138 WARN_ON(!mutex_is_locked(&pm_mutex));
139 if (saved_gfp_mask) {
140 gfp_allowed_mask = saved_gfp_mask;
145 void pm_restrict_gfp_mask(void)
147 WARN_ON(!mutex_is_locked(&pm_mutex));
148 WARN_ON(saved_gfp_mask);
149 saved_gfp_mask = gfp_allowed_mask;
150 gfp_allowed_mask &= ~GFP_IOFS;
153 bool pm_suspended_storage(void)
155 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
159 #endif /* CONFIG_PM_SLEEP */
161 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
162 int pageblock_order __read_mostly;
165 static void __free_pages_ok(struct page *page, unsigned int order);
168 * results with 256, 32 in the lowmem_reserve sysctl:
169 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
170 * 1G machine -> (16M dma, 784M normal, 224M high)
171 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
172 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
173 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
175 * TBD: should special case ZONE_DMA32 machines here - in those we normally
176 * don't need any ZONE_NORMAL reservation
178 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
179 #ifdef CONFIG_ZONE_DMA
182 #ifdef CONFIG_ZONE_DMA32
185 #ifdef CONFIG_HIGHMEM
191 EXPORT_SYMBOL(totalram_pages);
193 static char * const zone_names[MAX_NR_ZONES] = {
194 #ifdef CONFIG_ZONE_DMA
197 #ifdef CONFIG_ZONE_DMA32
201 #ifdef CONFIG_HIGHMEM
207 int min_free_kbytes = 1024;
208 int user_min_free_kbytes = -1;
210 static unsigned long __meminitdata nr_kernel_pages;
211 static unsigned long __meminitdata nr_all_pages;
212 static unsigned long __meminitdata dma_reserve;
214 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
215 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
216 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
217 static unsigned long __initdata required_kernelcore;
218 static unsigned long __initdata required_movablecore;
219 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
221 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
223 EXPORT_SYMBOL(movable_zone);
224 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
227 int nr_node_ids __read_mostly = MAX_NUMNODES;
228 int nr_online_nodes __read_mostly = 1;
229 EXPORT_SYMBOL(nr_node_ids);
230 EXPORT_SYMBOL(nr_online_nodes);
233 int page_group_by_mobility_disabled __read_mostly;
235 void set_pageblock_migratetype(struct page *page, int migratetype)
237 if (unlikely(page_group_by_mobility_disabled &&
238 migratetype < MIGRATE_PCPTYPES))
239 migratetype = MIGRATE_UNMOVABLE;
241 set_pageblock_flags_group(page, (unsigned long)migratetype,
242 PB_migrate, PB_migrate_end);
245 bool oom_killer_disabled __read_mostly;
247 #ifdef CONFIG_DEBUG_VM
248 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
252 unsigned long pfn = page_to_pfn(page);
253 unsigned long sp, start_pfn;
256 seq = zone_span_seqbegin(zone);
257 start_pfn = zone->zone_start_pfn;
258 sp = zone->spanned_pages;
259 if (!zone_spans_pfn(zone, pfn))
261 } while (zone_span_seqretry(zone, seq));
264 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
265 pfn, zone_to_nid(zone), zone->name,
266 start_pfn, start_pfn + sp);
271 static int page_is_consistent(struct zone *zone, struct page *page)
273 if (!pfn_valid_within(page_to_pfn(page)))
275 if (zone != page_zone(page))
281 * Temporary debugging check for pages not lying within a given zone.
283 static int bad_range(struct zone *zone, struct page *page)
285 if (page_outside_zone_boundaries(zone, page))
287 if (!page_is_consistent(zone, page))
293 static inline int bad_range(struct zone *zone, struct page *page)
299 static void bad_page(struct page *page, const char *reason,
300 unsigned long bad_flags)
302 static unsigned long resume;
303 static unsigned long nr_shown;
304 static unsigned long nr_unshown;
306 /* Don't complain about poisoned pages */
307 if (PageHWPoison(page)) {
308 page_mapcount_reset(page); /* remove PageBuddy */
313 * Allow a burst of 60 reports, then keep quiet for that minute;
314 * or allow a steady drip of one report per second.
316 if (nr_shown == 60) {
317 if (time_before(jiffies, resume)) {
323 "BUG: Bad page state: %lu messages suppressed\n",
330 resume = jiffies + 60 * HZ;
332 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
333 current->comm, page_to_pfn(page));
334 dump_page_badflags(page, reason, bad_flags);
339 /* Leave bad fields for debug, except PageBuddy could make trouble */
340 page_mapcount_reset(page); /* remove PageBuddy */
341 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
345 * Higher-order pages are called "compound pages". They are structured thusly:
347 * The first PAGE_SIZE page is called the "head page".
349 * The remaining PAGE_SIZE pages are called "tail pages".
351 * All pages have PG_compound set. All tail pages have their ->first_page
352 * pointing at the head page.
354 * The first tail page's ->lru.next holds the address of the compound page's
355 * put_page() function. Its ->lru.prev holds the order of allocation.
356 * This usage means that zero-order pages may not be compound.
359 static void free_compound_page(struct page *page)
361 __free_pages_ok(page, compound_order(page));
364 void prep_compound_page(struct page *page, unsigned long order)
367 int nr_pages = 1 << order;
369 set_compound_page_dtor(page, free_compound_page);
370 set_compound_order(page, order);
372 for (i = 1; i < nr_pages; i++) {
373 struct page *p = page + i;
374 set_page_count(p, 0);
375 p->first_page = page;
376 /* Make sure p->first_page is always valid for PageTail() */
382 /* update __split_huge_page_refcount if you change this function */
383 static int destroy_compound_page(struct page *page, unsigned long order)
386 int nr_pages = 1 << order;
389 if (unlikely(compound_order(page) != order)) {
390 bad_page(page, "wrong compound order", 0);
394 __ClearPageHead(page);
396 for (i = 1; i < nr_pages; i++) {
397 struct page *p = page + i;
399 if (unlikely(!PageTail(p))) {
400 bad_page(page, "PageTail not set", 0);
402 } else if (unlikely(p->first_page != page)) {
403 bad_page(page, "first_page not consistent", 0);
412 static inline void prep_zero_page(struct page *page, unsigned int order,
418 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
419 * and __GFP_HIGHMEM from hard or soft interrupt context.
421 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
422 for (i = 0; i < (1 << order); i++)
423 clear_highpage(page + i);
426 #ifdef CONFIG_DEBUG_PAGEALLOC
427 unsigned int _debug_guardpage_minorder;
429 static int __init debug_guardpage_minorder_setup(char *buf)
433 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
434 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
437 _debug_guardpage_minorder = res;
438 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
441 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
443 static inline void set_page_guard_flag(struct page *page)
445 __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
448 static inline void clear_page_guard_flag(struct page *page)
450 __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
453 static inline void set_page_guard_flag(struct page *page) { }
454 static inline void clear_page_guard_flag(struct page *page) { }
457 static inline void set_page_order(struct page *page, unsigned int order)
459 set_page_private(page, order);
460 __SetPageBuddy(page);
463 static inline void rmv_page_order(struct page *page)
465 __ClearPageBuddy(page);
466 set_page_private(page, 0);
470 * This function checks whether a page is free && is the buddy
471 * we can do coalesce a page and its buddy if
472 * (a) the buddy is not in a hole &&
473 * (b) the buddy is in the buddy system &&
474 * (c) a page and its buddy have the same order &&
475 * (d) a page and its buddy are in the same zone.
477 * For recording whether a page is in the buddy system, we set ->_mapcount
478 * PAGE_BUDDY_MAPCOUNT_VALUE.
479 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
480 * serialized by zone->lock.
482 * For recording page's order, we use page_private(page).
484 static inline int page_is_buddy(struct page *page, struct page *buddy,
487 if (!pfn_valid_within(page_to_pfn(buddy)))
490 if (page_is_guard(buddy) && page_order(buddy) == order) {
491 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
493 if (page_zone_id(page) != page_zone_id(buddy))
499 if (PageBuddy(buddy) && page_order(buddy) == order) {
500 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
503 * zone check is done late to avoid uselessly
504 * calculating zone/node ids for pages that could
507 if (page_zone_id(page) != page_zone_id(buddy))
516 * Freeing function for a buddy system allocator.
518 * The concept of a buddy system is to maintain direct-mapped table
519 * (containing bit values) for memory blocks of various "orders".
520 * The bottom level table contains the map for the smallest allocatable
521 * units of memory (here, pages), and each level above it describes
522 * pairs of units from the levels below, hence, "buddies".
523 * At a high level, all that happens here is marking the table entry
524 * at the bottom level available, and propagating the changes upward
525 * as necessary, plus some accounting needed to play nicely with other
526 * parts of the VM system.
527 * At each level, we keep a list of pages, which are heads of continuous
528 * free pages of length of (1 << order) and marked with _mapcount
529 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
531 * So when we are allocating or freeing one, we can derive the state of the
532 * other. That is, if we allocate a small block, and both were
533 * free, the remainder of the region must be split into blocks.
534 * If a block is freed, and its buddy is also free, then this
535 * triggers coalescing into a block of larger size.
540 static inline void __free_one_page(struct page *page,
542 struct zone *zone, unsigned int order,
545 unsigned long page_idx;
546 unsigned long combined_idx;
547 unsigned long uninitialized_var(buddy_idx);
549 int max_order = MAX_ORDER;
551 VM_BUG_ON(!zone_is_initialized(zone));
553 if (unlikely(PageCompound(page)))
554 if (unlikely(destroy_compound_page(page, order)))
557 VM_BUG_ON(migratetype == -1);
558 if (is_migrate_isolate(migratetype)) {
560 * We restrict max order of merging to prevent merge
561 * between freepages on isolate pageblock and normal
562 * pageblock. Without this, pageblock isolation
563 * could cause incorrect freepage accounting.
565 max_order = min(MAX_ORDER, pageblock_order + 1);
567 __mod_zone_freepage_state(zone, 1 << order, migratetype);
570 page_idx = pfn & ((1 << max_order) - 1);
572 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
573 VM_BUG_ON_PAGE(bad_range(zone, page), page);
575 while (order < max_order - 1) {
576 buddy_idx = __find_buddy_index(page_idx, order);
577 buddy = page + (buddy_idx - page_idx);
578 if (!page_is_buddy(page, buddy, order))
581 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
582 * merge with it and move up one order.
584 if (page_is_guard(buddy)) {
585 clear_page_guard_flag(buddy);
586 set_page_private(buddy, 0);
587 if (!is_migrate_isolate(migratetype)) {
588 __mod_zone_freepage_state(zone, 1 << order,
592 list_del(&buddy->lru);
593 zone->free_area[order].nr_free--;
594 rmv_page_order(buddy);
596 combined_idx = buddy_idx & page_idx;
597 page = page + (combined_idx - page_idx);
598 page_idx = combined_idx;
601 set_page_order(page, order);
604 * If this is not the largest possible page, check if the buddy
605 * of the next-highest order is free. If it is, it's possible
606 * that pages are being freed that will coalesce soon. In case,
607 * that is happening, add the free page to the tail of the list
608 * so it's less likely to be used soon and more likely to be merged
609 * as a higher order page
611 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
612 struct page *higher_page, *higher_buddy;
613 combined_idx = buddy_idx & page_idx;
614 higher_page = page + (combined_idx - page_idx);
615 buddy_idx = __find_buddy_index(combined_idx, order + 1);
616 higher_buddy = higher_page + (buddy_idx - combined_idx);
617 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
618 list_add_tail(&page->lru,
619 &zone->free_area[order].free_list[migratetype]);
624 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
626 zone->free_area[order].nr_free++;
629 static inline int free_pages_check(struct page *page)
631 const char *bad_reason = NULL;
632 unsigned long bad_flags = 0;
634 if (unlikely(page_mapcount(page)))
635 bad_reason = "nonzero mapcount";
636 if (unlikely(page->mapping != NULL))
637 bad_reason = "non-NULL mapping";
638 if (unlikely(atomic_read(&page->_count) != 0))
639 bad_reason = "nonzero _count";
640 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
641 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
642 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
644 if (unlikely(mem_cgroup_bad_page_check(page)))
645 bad_reason = "cgroup check failed";
646 if (unlikely(bad_reason)) {
647 bad_page(page, bad_reason, bad_flags);
650 page_cpupid_reset_last(page);
651 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
652 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
657 * Frees a number of pages from the PCP lists
658 * Assumes all pages on list are in same zone, and of same order.
659 * count is the number of pages to free.
661 * If the zone was previously in an "all pages pinned" state then look to
662 * see if this freeing clears that state.
664 * And clear the zone's pages_scanned counter, to hold off the "all pages are
665 * pinned" detection logic.
667 static void free_pcppages_bulk(struct zone *zone, int count,
668 struct per_cpu_pages *pcp)
673 unsigned long nr_scanned;
675 spin_lock(&zone->lock);
676 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
678 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
682 struct list_head *list;
685 * Remove pages from lists in a round-robin fashion. A
686 * batch_free count is maintained that is incremented when an
687 * empty list is encountered. This is so more pages are freed
688 * off fuller lists instead of spinning excessively around empty
693 if (++migratetype == MIGRATE_PCPTYPES)
695 list = &pcp->lists[migratetype];
696 } while (list_empty(list));
698 /* This is the only non-empty list. Free them all. */
699 if (batch_free == MIGRATE_PCPTYPES)
700 batch_free = to_free;
703 int mt; /* migratetype of the to-be-freed page */
705 page = list_entry(list->prev, struct page, lru);
706 /* must delete as __free_one_page list manipulates */
707 list_del(&page->lru);
708 mt = get_freepage_migratetype(page);
709 if (unlikely(has_isolate_pageblock(zone)))
710 mt = get_pageblock_migratetype(page);
712 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
713 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
714 trace_mm_page_pcpu_drain(page, 0, mt);
715 } while (--to_free && --batch_free && !list_empty(list));
717 spin_unlock(&zone->lock);
720 static void free_one_page(struct zone *zone,
721 struct page *page, unsigned long pfn,
725 unsigned long nr_scanned;
726 spin_lock(&zone->lock);
727 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
729 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
731 if (unlikely(has_isolate_pageblock(zone) ||
732 is_migrate_isolate(migratetype))) {
733 migratetype = get_pfnblock_migratetype(page, pfn);
735 __free_one_page(page, pfn, zone, order, migratetype);
736 spin_unlock(&zone->lock);
739 static bool free_pages_prepare(struct page *page, unsigned int order)
744 VM_BUG_ON_PAGE(PageTail(page), page);
745 VM_BUG_ON_PAGE(PageHead(page) && compound_order(page) != order, page);
747 trace_mm_page_free(page, order);
748 kmemcheck_free_shadow(page, order);
751 page->mapping = NULL;
752 for (i = 0; i < (1 << order); i++)
753 bad += free_pages_check(page + i);
757 if (!PageHighMem(page)) {
758 debug_check_no_locks_freed(page_address(page),
760 debug_check_no_obj_freed(page_address(page),
763 arch_free_page(page, order);
764 kernel_map_pages(page, 1 << order, 0);
769 static void __free_pages_ok(struct page *page, unsigned int order)
773 unsigned long pfn = page_to_pfn(page);
775 if (!free_pages_prepare(page, order))
778 migratetype = get_pfnblock_migratetype(page, pfn);
779 local_irq_save(flags);
780 __count_vm_events(PGFREE, 1 << order);
781 set_freepage_migratetype(page, migratetype);
782 free_one_page(page_zone(page), page, pfn, order, migratetype);
783 local_irq_restore(flags);
786 void __init __free_pages_bootmem(struct page *page, unsigned int order)
788 unsigned int nr_pages = 1 << order;
789 struct page *p = page;
793 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
795 __ClearPageReserved(p);
796 set_page_count(p, 0);
798 __ClearPageReserved(p);
799 set_page_count(p, 0);
801 page_zone(page)->managed_pages += nr_pages;
802 set_page_refcounted(page);
803 __free_pages(page, order);
807 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
808 void __init init_cma_reserved_pageblock(struct page *page)
810 unsigned i = pageblock_nr_pages;
811 struct page *p = page;
814 __ClearPageReserved(p);
815 set_page_count(p, 0);
818 set_pageblock_migratetype(page, MIGRATE_CMA);
820 if (pageblock_order >= MAX_ORDER) {
821 i = pageblock_nr_pages;
824 set_page_refcounted(p);
825 __free_pages(p, MAX_ORDER - 1);
826 p += MAX_ORDER_NR_PAGES;
827 } while (i -= MAX_ORDER_NR_PAGES);
829 set_page_refcounted(page);
830 __free_pages(page, pageblock_order);
833 adjust_managed_page_count(page, pageblock_nr_pages);
838 * The order of subdivision here is critical for the IO subsystem.
839 * Please do not alter this order without good reasons and regression
840 * testing. Specifically, as large blocks of memory are subdivided,
841 * the order in which smaller blocks are delivered depends on the order
842 * they're subdivided in this function. This is the primary factor
843 * influencing the order in which pages are delivered to the IO
844 * subsystem according to empirical testing, and this is also justified
845 * by considering the behavior of a buddy system containing a single
846 * large block of memory acted on by a series of small allocations.
847 * This behavior is a critical factor in sglist merging's success.
851 static inline void expand(struct zone *zone, struct page *page,
852 int low, int high, struct free_area *area,
855 unsigned long size = 1 << high;
861 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
863 #ifdef CONFIG_DEBUG_PAGEALLOC
864 if (high < debug_guardpage_minorder()) {
866 * Mark as guard pages (or page), that will allow to
867 * merge back to allocator when buddy will be freed.
868 * Corresponding page table entries will not be touched,
869 * pages will stay not present in virtual address space
871 INIT_LIST_HEAD(&page[size].lru);
872 set_page_guard_flag(&page[size]);
873 set_page_private(&page[size], high);
874 /* Guard pages are not available for any usage */
875 __mod_zone_freepage_state(zone, -(1 << high),
880 list_add(&page[size].lru, &area->free_list[migratetype]);
882 set_page_order(&page[size], high);
887 * This page is about to be returned from the page allocator
889 static inline int check_new_page(struct page *page)
891 const char *bad_reason = NULL;
892 unsigned long bad_flags = 0;
894 if (unlikely(page_mapcount(page)))
895 bad_reason = "nonzero mapcount";
896 if (unlikely(page->mapping != NULL))
897 bad_reason = "non-NULL mapping";
898 if (unlikely(atomic_read(&page->_count) != 0))
899 bad_reason = "nonzero _count";
900 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
901 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
902 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
904 if (unlikely(mem_cgroup_bad_page_check(page)))
905 bad_reason = "cgroup check failed";
906 if (unlikely(bad_reason)) {
907 bad_page(page, bad_reason, bad_flags);
913 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags)
917 for (i = 0; i < (1 << order); i++) {
918 struct page *p = page + i;
919 if (unlikely(check_new_page(p)))
923 set_page_private(page, 0);
924 set_page_refcounted(page);
926 arch_alloc_page(page, order);
927 kernel_map_pages(page, 1 << order, 1);
929 if (gfp_flags & __GFP_ZERO)
930 prep_zero_page(page, order, gfp_flags);
932 if (order && (gfp_flags & __GFP_COMP))
933 prep_compound_page(page, order);
939 * Go through the free lists for the given migratetype and remove
940 * the smallest available page from the freelists
943 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
946 unsigned int current_order;
947 struct free_area *area;
950 /* Find a page of the appropriate size in the preferred list */
951 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
952 area = &(zone->free_area[current_order]);
953 if (list_empty(&area->free_list[migratetype]))
956 page = list_entry(area->free_list[migratetype].next,
958 list_del(&page->lru);
959 rmv_page_order(page);
961 expand(zone, page, order, current_order, area, migratetype);
962 set_freepage_migratetype(page, migratetype);
971 * This array describes the order lists are fallen back to when
972 * the free lists for the desirable migrate type are depleted
974 static int fallbacks[MIGRATE_TYPES][4] = {
975 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
976 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
978 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
979 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
981 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
983 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
984 #ifdef CONFIG_MEMORY_ISOLATION
985 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
990 * Move the free pages in a range to the free lists of the requested type.
991 * Note that start_page and end_pages are not aligned on a pageblock
992 * boundary. If alignment is required, use move_freepages_block()
994 int move_freepages(struct zone *zone,
995 struct page *start_page, struct page *end_page,
1000 int pages_moved = 0;
1002 #ifndef CONFIG_HOLES_IN_ZONE
1004 * page_zone is not safe to call in this context when
1005 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1006 * anyway as we check zone boundaries in move_freepages_block().
1007 * Remove at a later date when no bug reports exist related to
1008 * grouping pages by mobility
1010 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1013 for (page = start_page; page <= end_page;) {
1014 /* Make sure we are not inadvertently changing nodes */
1015 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1017 if (!pfn_valid_within(page_to_pfn(page))) {
1022 if (!PageBuddy(page)) {
1027 order = page_order(page);
1028 list_move(&page->lru,
1029 &zone->free_area[order].free_list[migratetype]);
1030 set_freepage_migratetype(page, migratetype);
1032 pages_moved += 1 << order;
1038 int move_freepages_block(struct zone *zone, struct page *page,
1041 unsigned long start_pfn, end_pfn;
1042 struct page *start_page, *end_page;
1044 start_pfn = page_to_pfn(page);
1045 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1046 start_page = pfn_to_page(start_pfn);
1047 end_page = start_page + pageblock_nr_pages - 1;
1048 end_pfn = start_pfn + pageblock_nr_pages - 1;
1050 /* Do not cross zone boundaries */
1051 if (!zone_spans_pfn(zone, start_pfn))
1053 if (!zone_spans_pfn(zone, end_pfn))
1056 return move_freepages(zone, start_page, end_page, migratetype);
1059 static void change_pageblock_range(struct page *pageblock_page,
1060 int start_order, int migratetype)
1062 int nr_pageblocks = 1 << (start_order - pageblock_order);
1064 while (nr_pageblocks--) {
1065 set_pageblock_migratetype(pageblock_page, migratetype);
1066 pageblock_page += pageblock_nr_pages;
1071 * If breaking a large block of pages, move all free pages to the preferred
1072 * allocation list. If falling back for a reclaimable kernel allocation, be
1073 * more aggressive about taking ownership of free pages.
1075 * On the other hand, never change migration type of MIGRATE_CMA pageblocks
1076 * nor move CMA pages to different free lists. We don't want unmovable pages
1077 * to be allocated from MIGRATE_CMA areas.
1079 * Returns the new migratetype of the pageblock (or the same old migratetype
1080 * if it was unchanged).
1082 static int try_to_steal_freepages(struct zone *zone, struct page *page,
1083 int start_type, int fallback_type)
1085 int current_order = page_order(page);
1088 * When borrowing from MIGRATE_CMA, we need to release the excess
1089 * buddy pages to CMA itself. We also ensure the freepage_migratetype
1090 * is set to CMA so it is returned to the correct freelist in case
1091 * the page ends up being not actually allocated from the pcp lists.
1093 if (is_migrate_cma(fallback_type))
1094 return fallback_type;
1096 /* Take ownership for orders >= pageblock_order */
1097 if (current_order >= pageblock_order) {
1098 change_pageblock_range(page, current_order, start_type);
1102 if (current_order >= pageblock_order / 2 ||
1103 start_type == MIGRATE_RECLAIMABLE ||
1104 page_group_by_mobility_disabled) {
1107 pages = move_freepages_block(zone, page, start_type);
1109 /* Claim the whole block if over half of it is free */
1110 if (pages >= (1 << (pageblock_order-1)) ||
1111 page_group_by_mobility_disabled) {
1113 set_pageblock_migratetype(page, start_type);
1119 return fallback_type;
1122 /* Remove an element from the buddy allocator from the fallback list */
1123 static inline struct page *
1124 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1126 struct free_area *area;
1127 unsigned int current_order;
1129 int migratetype, new_type, i;
1131 /* Find the largest possible block of pages in the other list */
1132 for (current_order = MAX_ORDER-1;
1133 current_order >= order && current_order <= MAX_ORDER-1;
1136 migratetype = fallbacks[start_migratetype][i];
1138 /* MIGRATE_RESERVE handled later if necessary */
1139 if (migratetype == MIGRATE_RESERVE)
1142 area = &(zone->free_area[current_order]);
1143 if (list_empty(&area->free_list[migratetype]))
1146 page = list_entry(area->free_list[migratetype].next,
1150 new_type = try_to_steal_freepages(zone, page,
1154 /* Remove the page from the freelists */
1155 list_del(&page->lru);
1156 rmv_page_order(page);
1158 expand(zone, page, order, current_order, area,
1160 /* The freepage_migratetype may differ from pageblock's
1161 * migratetype depending on the decisions in
1162 * try_to_steal_freepages. This is OK as long as it does
1163 * not differ for MIGRATE_CMA type.
1165 set_freepage_migratetype(page, new_type);
1167 trace_mm_page_alloc_extfrag(page, order, current_order,
1168 start_migratetype, migratetype, new_type);
1178 * Do the hard work of removing an element from the buddy allocator.
1179 * Call me with the zone->lock already held.
1181 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1187 page = __rmqueue_smallest(zone, order, migratetype);
1189 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1190 page = __rmqueue_fallback(zone, order, migratetype);
1193 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1194 * is used because __rmqueue_smallest is an inline function
1195 * and we want just one call site
1198 migratetype = MIGRATE_RESERVE;
1203 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1208 * Obtain a specified number of elements from the buddy allocator, all under
1209 * a single hold of the lock, for efficiency. Add them to the supplied list.
1210 * Returns the number of new pages which were placed at *list.
1212 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1213 unsigned long count, struct list_head *list,
1214 int migratetype, bool cold)
1218 spin_lock(&zone->lock);
1219 for (i = 0; i < count; ++i) {
1220 struct page *page = __rmqueue(zone, order, migratetype);
1221 if (unlikely(page == NULL))
1225 * Split buddy pages returned by expand() are received here
1226 * in physical page order. The page is added to the callers and
1227 * list and the list head then moves forward. From the callers
1228 * perspective, the linked list is ordered by page number in
1229 * some conditions. This is useful for IO devices that can
1230 * merge IO requests if the physical pages are ordered
1234 list_add(&page->lru, list);
1236 list_add_tail(&page->lru, list);
1238 if (is_migrate_cma(get_freepage_migratetype(page)))
1239 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1242 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1243 spin_unlock(&zone->lock);
1249 * Called from the vmstat counter updater to drain pagesets of this
1250 * currently executing processor on remote nodes after they have
1253 * Note that this function must be called with the thread pinned to
1254 * a single processor.
1256 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1258 unsigned long flags;
1259 int to_drain, batch;
1261 local_irq_save(flags);
1262 batch = ACCESS_ONCE(pcp->batch);
1263 to_drain = min(pcp->count, batch);
1265 free_pcppages_bulk(zone, to_drain, pcp);
1266 pcp->count -= to_drain;
1268 local_irq_restore(flags);
1273 * Drain pcplists of the indicated processor and zone.
1275 * The processor must either be the current processor and the
1276 * thread pinned to the current processor or a processor that
1279 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
1281 unsigned long flags;
1282 struct per_cpu_pageset *pset;
1283 struct per_cpu_pages *pcp;
1285 local_irq_save(flags);
1286 pset = per_cpu_ptr(zone->pageset, cpu);
1290 free_pcppages_bulk(zone, pcp->count, pcp);
1293 local_irq_restore(flags);
1297 * Drain pcplists of all zones on the indicated processor.
1299 * The processor must either be the current processor and the
1300 * thread pinned to the current processor or a processor that
1303 static void drain_pages(unsigned int cpu)
1307 for_each_populated_zone(zone) {
1308 drain_pages_zone(cpu, zone);
1313 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1315 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1316 * the single zone's pages.
1318 void drain_local_pages(struct zone *zone)
1320 int cpu = smp_processor_id();
1323 drain_pages_zone(cpu, zone);
1329 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1331 * When zone parameter is non-NULL, spill just the single zone's pages.
1333 * Note that this code is protected against sending an IPI to an offline
1334 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1335 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1336 * nothing keeps CPUs from showing up after we populated the cpumask and
1337 * before the call to on_each_cpu_mask().
1339 void drain_all_pages(struct zone *zone)
1344 * Allocate in the BSS so we wont require allocation in
1345 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1347 static cpumask_t cpus_with_pcps;
1350 * We don't care about racing with CPU hotplug event
1351 * as offline notification will cause the notified
1352 * cpu to drain that CPU pcps and on_each_cpu_mask
1353 * disables preemption as part of its processing
1355 for_each_online_cpu(cpu) {
1356 struct per_cpu_pageset *pcp;
1358 bool has_pcps = false;
1361 pcp = per_cpu_ptr(zone->pageset, cpu);
1365 for_each_populated_zone(z) {
1366 pcp = per_cpu_ptr(z->pageset, cpu);
1367 if (pcp->pcp.count) {
1375 cpumask_set_cpu(cpu, &cpus_with_pcps);
1377 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1379 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
1383 #ifdef CONFIG_HIBERNATION
1385 void mark_free_pages(struct zone *zone)
1387 unsigned long pfn, max_zone_pfn;
1388 unsigned long flags;
1389 unsigned int order, t;
1390 struct list_head *curr;
1392 if (zone_is_empty(zone))
1395 spin_lock_irqsave(&zone->lock, flags);
1397 max_zone_pfn = zone_end_pfn(zone);
1398 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1399 if (pfn_valid(pfn)) {
1400 struct page *page = pfn_to_page(pfn);
1402 if (!swsusp_page_is_forbidden(page))
1403 swsusp_unset_page_free(page);
1406 for_each_migratetype_order(order, t) {
1407 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1410 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1411 for (i = 0; i < (1UL << order); i++)
1412 swsusp_set_page_free(pfn_to_page(pfn + i));
1415 spin_unlock_irqrestore(&zone->lock, flags);
1417 #endif /* CONFIG_PM */
1420 * Free a 0-order page
1421 * cold == true ? free a cold page : free a hot page
1423 void free_hot_cold_page(struct page *page, bool cold)
1425 struct zone *zone = page_zone(page);
1426 struct per_cpu_pages *pcp;
1427 unsigned long flags;
1428 unsigned long pfn = page_to_pfn(page);
1431 if (!free_pages_prepare(page, 0))
1434 migratetype = get_pfnblock_migratetype(page, pfn);
1435 set_freepage_migratetype(page, migratetype);
1436 local_irq_save(flags);
1437 __count_vm_event(PGFREE);
1440 * We only track unmovable, reclaimable and movable on pcp lists.
1441 * Free ISOLATE pages back to the allocator because they are being
1442 * offlined but treat RESERVE as movable pages so we can get those
1443 * areas back if necessary. Otherwise, we may have to free
1444 * excessively into the page allocator
1446 if (migratetype >= MIGRATE_PCPTYPES) {
1447 if (unlikely(is_migrate_isolate(migratetype))) {
1448 free_one_page(zone, page, pfn, 0, migratetype);
1451 migratetype = MIGRATE_MOVABLE;
1454 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1456 list_add(&page->lru, &pcp->lists[migratetype]);
1458 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1460 if (pcp->count >= pcp->high) {
1461 unsigned long batch = ACCESS_ONCE(pcp->batch);
1462 free_pcppages_bulk(zone, batch, pcp);
1463 pcp->count -= batch;
1467 local_irq_restore(flags);
1471 * Free a list of 0-order pages
1473 void free_hot_cold_page_list(struct list_head *list, bool cold)
1475 struct page *page, *next;
1477 list_for_each_entry_safe(page, next, list, lru) {
1478 trace_mm_page_free_batched(page, cold);
1479 free_hot_cold_page(page, cold);
1484 * split_page takes a non-compound higher-order page, and splits it into
1485 * n (1<<order) sub-pages: page[0..n]
1486 * Each sub-page must be freed individually.
1488 * Note: this is probably too low level an operation for use in drivers.
1489 * Please consult with lkml before using this in your driver.
1491 void split_page(struct page *page, unsigned int order)
1495 VM_BUG_ON_PAGE(PageCompound(page), page);
1496 VM_BUG_ON_PAGE(!page_count(page), page);
1498 #ifdef CONFIG_KMEMCHECK
1500 * Split shadow pages too, because free(page[0]) would
1501 * otherwise free the whole shadow.
1503 if (kmemcheck_page_is_tracked(page))
1504 split_page(virt_to_page(page[0].shadow), order);
1507 for (i = 1; i < (1 << order); i++)
1508 set_page_refcounted(page + i);
1510 EXPORT_SYMBOL_GPL(split_page);
1512 int __isolate_free_page(struct page *page, unsigned int order)
1514 unsigned long watermark;
1518 BUG_ON(!PageBuddy(page));
1520 zone = page_zone(page);
1521 mt = get_pageblock_migratetype(page);
1523 if (!is_migrate_isolate(mt)) {
1524 /* Obey watermarks as if the page was being allocated */
1525 watermark = low_wmark_pages(zone) + (1 << order);
1526 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1529 __mod_zone_freepage_state(zone, -(1UL << order), mt);
1532 /* Remove page from free list */
1533 list_del(&page->lru);
1534 zone->free_area[order].nr_free--;
1535 rmv_page_order(page);
1537 /* Set the pageblock if the isolated page is at least a pageblock */
1538 if (order >= pageblock_order - 1) {
1539 struct page *endpage = page + (1 << order) - 1;
1540 for (; page < endpage; page += pageblock_nr_pages) {
1541 int mt = get_pageblock_migratetype(page);
1542 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
1543 set_pageblock_migratetype(page,
1548 return 1UL << order;
1552 * Similar to split_page except the page is already free. As this is only
1553 * being used for migration, the migratetype of the block also changes.
1554 * As this is called with interrupts disabled, the caller is responsible
1555 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1558 * Note: this is probably too low level an operation for use in drivers.
1559 * Please consult with lkml before using this in your driver.
1561 int split_free_page(struct page *page)
1566 order = page_order(page);
1568 nr_pages = __isolate_free_page(page, order);
1572 /* Split into individual pages */
1573 set_page_refcounted(page);
1574 split_page(page, order);
1579 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1580 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1584 struct page *buffered_rmqueue(struct zone *preferred_zone,
1585 struct zone *zone, unsigned int order,
1586 gfp_t gfp_flags, int migratetype)
1588 unsigned long flags;
1590 bool cold = ((gfp_flags & __GFP_COLD) != 0);
1593 if (likely(order == 0)) {
1594 struct per_cpu_pages *pcp;
1595 struct list_head *list;
1597 local_irq_save(flags);
1598 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1599 list = &pcp->lists[migratetype];
1600 if (list_empty(list)) {
1601 pcp->count += rmqueue_bulk(zone, 0,
1604 if (unlikely(list_empty(list)))
1609 page = list_entry(list->prev, struct page, lru);
1611 page = list_entry(list->next, struct page, lru);
1613 list_del(&page->lru);
1616 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1618 * __GFP_NOFAIL is not to be used in new code.
1620 * All __GFP_NOFAIL callers should be fixed so that they
1621 * properly detect and handle allocation failures.
1623 * We most definitely don't want callers attempting to
1624 * allocate greater than order-1 page units with
1627 WARN_ON_ONCE(order > 1);
1629 spin_lock_irqsave(&zone->lock, flags);
1630 page = __rmqueue(zone, order, migratetype);
1631 spin_unlock(&zone->lock);
1634 __mod_zone_freepage_state(zone, -(1 << order),
1635 get_freepage_migratetype(page));
1638 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
1639 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
1640 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
1641 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
1643 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1644 zone_statistics(preferred_zone, zone, gfp_flags);
1645 local_irq_restore(flags);
1647 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1648 if (prep_new_page(page, order, gfp_flags))
1653 local_irq_restore(flags);
1657 #ifdef CONFIG_FAIL_PAGE_ALLOC
1660 struct fault_attr attr;
1662 u32 ignore_gfp_highmem;
1663 u32 ignore_gfp_wait;
1665 } fail_page_alloc = {
1666 .attr = FAULT_ATTR_INITIALIZER,
1667 .ignore_gfp_wait = 1,
1668 .ignore_gfp_highmem = 1,
1672 static int __init setup_fail_page_alloc(char *str)
1674 return setup_fault_attr(&fail_page_alloc.attr, str);
1676 __setup("fail_page_alloc=", setup_fail_page_alloc);
1678 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1680 if (order < fail_page_alloc.min_order)
1682 if (gfp_mask & __GFP_NOFAIL)
1684 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1686 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1689 return should_fail(&fail_page_alloc.attr, 1 << order);
1692 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1694 static int __init fail_page_alloc_debugfs(void)
1696 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1699 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1700 &fail_page_alloc.attr);
1702 return PTR_ERR(dir);
1704 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1705 &fail_page_alloc.ignore_gfp_wait))
1707 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1708 &fail_page_alloc.ignore_gfp_highmem))
1710 if (!debugfs_create_u32("min-order", mode, dir,
1711 &fail_page_alloc.min_order))
1716 debugfs_remove_recursive(dir);
1721 late_initcall(fail_page_alloc_debugfs);
1723 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1725 #else /* CONFIG_FAIL_PAGE_ALLOC */
1727 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1732 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1735 * Return true if free pages are above 'mark'. This takes into account the order
1736 * of the allocation.
1738 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
1739 unsigned long mark, int classzone_idx, int alloc_flags,
1742 /* free_pages my go negative - that's OK */
1747 free_pages -= (1 << order) - 1;
1748 if (alloc_flags & ALLOC_HIGH)
1750 if (alloc_flags & ALLOC_HARDER)
1753 /* If allocation can't use CMA areas don't use free CMA pages */
1754 if (!(alloc_flags & ALLOC_CMA))
1755 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
1758 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
1760 for (o = 0; o < order; o++) {
1761 /* At the next order, this order's pages become unavailable */
1762 free_pages -= z->free_area[o].nr_free << o;
1764 /* Require fewer higher order pages to be free */
1767 if (free_pages <= min)
1773 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1774 int classzone_idx, int alloc_flags)
1776 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1777 zone_page_state(z, NR_FREE_PAGES));
1780 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1781 unsigned long mark, int classzone_idx, int alloc_flags)
1783 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1785 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1786 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1788 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1794 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1795 * skip over zones that are not allowed by the cpuset, or that have
1796 * been recently (in last second) found to be nearly full. See further
1797 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1798 * that have to skip over a lot of full or unallowed zones.
1800 * If the zonelist cache is present in the passed zonelist, then
1801 * returns a pointer to the allowed node mask (either the current
1802 * tasks mems_allowed, or node_states[N_MEMORY].)
1804 * If the zonelist cache is not available for this zonelist, does
1805 * nothing and returns NULL.
1807 * If the fullzones BITMAP in the zonelist cache is stale (more than
1808 * a second since last zap'd) then we zap it out (clear its bits.)
1810 * We hold off even calling zlc_setup, until after we've checked the
1811 * first zone in the zonelist, on the theory that most allocations will
1812 * be satisfied from that first zone, so best to examine that zone as
1813 * quickly as we can.
1815 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1817 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1818 nodemask_t *allowednodes; /* zonelist_cache approximation */
1820 zlc = zonelist->zlcache_ptr;
1824 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1825 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1826 zlc->last_full_zap = jiffies;
1829 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1830 &cpuset_current_mems_allowed :
1831 &node_states[N_MEMORY];
1832 return allowednodes;
1836 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1837 * if it is worth looking at further for free memory:
1838 * 1) Check that the zone isn't thought to be full (doesn't have its
1839 * bit set in the zonelist_cache fullzones BITMAP).
1840 * 2) Check that the zones node (obtained from the zonelist_cache
1841 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1842 * Return true (non-zero) if zone is worth looking at further, or
1843 * else return false (zero) if it is not.
1845 * This check -ignores- the distinction between various watermarks,
1846 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1847 * found to be full for any variation of these watermarks, it will
1848 * be considered full for up to one second by all requests, unless
1849 * we are so low on memory on all allowed nodes that we are forced
1850 * into the second scan of the zonelist.
1852 * In the second scan we ignore this zonelist cache and exactly
1853 * apply the watermarks to all zones, even it is slower to do so.
1854 * We are low on memory in the second scan, and should leave no stone
1855 * unturned looking for a free page.
1857 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1858 nodemask_t *allowednodes)
1860 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1861 int i; /* index of *z in zonelist zones */
1862 int n; /* node that zone *z is on */
1864 zlc = zonelist->zlcache_ptr;
1868 i = z - zonelist->_zonerefs;
1871 /* This zone is worth trying if it is allowed but not full */
1872 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1876 * Given 'z' scanning a zonelist, set the corresponding bit in
1877 * zlc->fullzones, so that subsequent attempts to allocate a page
1878 * from that zone don't waste time re-examining it.
1880 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1882 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1883 int i; /* index of *z in zonelist zones */
1885 zlc = zonelist->zlcache_ptr;
1889 i = z - zonelist->_zonerefs;
1891 set_bit(i, zlc->fullzones);
1895 * clear all zones full, called after direct reclaim makes progress so that
1896 * a zone that was recently full is not skipped over for up to a second
1898 static void zlc_clear_zones_full(struct zonelist *zonelist)
1900 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1902 zlc = zonelist->zlcache_ptr;
1906 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1909 static bool zone_local(struct zone *local_zone, struct zone *zone)
1911 return local_zone->node == zone->node;
1914 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1916 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
1920 #else /* CONFIG_NUMA */
1922 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1927 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1928 nodemask_t *allowednodes)
1933 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1937 static void zlc_clear_zones_full(struct zonelist *zonelist)
1941 static bool zone_local(struct zone *local_zone, struct zone *zone)
1946 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1951 #endif /* CONFIG_NUMA */
1953 static void reset_alloc_batches(struct zone *preferred_zone)
1955 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
1958 mod_zone_page_state(zone, NR_ALLOC_BATCH,
1959 high_wmark_pages(zone) - low_wmark_pages(zone) -
1960 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
1961 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
1962 } while (zone++ != preferred_zone);
1966 * get_page_from_freelist goes through the zonelist trying to allocate
1969 static struct page *
1970 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1971 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1972 struct zone *preferred_zone, int classzone_idx, int migratetype)
1975 struct page *page = NULL;
1977 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1978 int zlc_active = 0; /* set if using zonelist_cache */
1979 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1980 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
1981 (gfp_mask & __GFP_WRITE);
1982 int nr_fair_skipped = 0;
1983 bool zonelist_rescan;
1986 zonelist_rescan = false;
1989 * Scan zonelist, looking for a zone with enough free.
1990 * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
1992 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1993 high_zoneidx, nodemask) {
1996 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1997 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1999 if (cpusets_enabled() &&
2000 (alloc_flags & ALLOC_CPUSET) &&
2001 !cpuset_zone_allowed_softwall(zone, gfp_mask))
2004 * Distribute pages in proportion to the individual
2005 * zone size to ensure fair page aging. The zone a
2006 * page was allocated in should have no effect on the
2007 * time the page has in memory before being reclaimed.
2009 if (alloc_flags & ALLOC_FAIR) {
2010 if (!zone_local(preferred_zone, zone))
2012 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2018 * When allocating a page cache page for writing, we
2019 * want to get it from a zone that is within its dirty
2020 * limit, such that no single zone holds more than its
2021 * proportional share of globally allowed dirty pages.
2022 * The dirty limits take into account the zone's
2023 * lowmem reserves and high watermark so that kswapd
2024 * should be able to balance it without having to
2025 * write pages from its LRU list.
2027 * This may look like it could increase pressure on
2028 * lower zones by failing allocations in higher zones
2029 * before they are full. But the pages that do spill
2030 * over are limited as the lower zones are protected
2031 * by this very same mechanism. It should not become
2032 * a practical burden to them.
2034 * XXX: For now, allow allocations to potentially
2035 * exceed the per-zone dirty limit in the slowpath
2036 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2037 * which is important when on a NUMA setup the allowed
2038 * zones are together not big enough to reach the
2039 * global limit. The proper fix for these situations
2040 * will require awareness of zones in the
2041 * dirty-throttling and the flusher threads.
2043 if (consider_zone_dirty && !zone_dirty_ok(zone))
2046 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2047 if (!zone_watermark_ok(zone, order, mark,
2048 classzone_idx, alloc_flags)) {
2051 /* Checked here to keep the fast path fast */
2052 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2053 if (alloc_flags & ALLOC_NO_WATERMARKS)
2056 if (IS_ENABLED(CONFIG_NUMA) &&
2057 !did_zlc_setup && nr_online_nodes > 1) {
2059 * we do zlc_setup if there are multiple nodes
2060 * and before considering the first zone allowed
2063 allowednodes = zlc_setup(zonelist, alloc_flags);
2068 if (zone_reclaim_mode == 0 ||
2069 !zone_allows_reclaim(preferred_zone, zone))
2070 goto this_zone_full;
2073 * As we may have just activated ZLC, check if the first
2074 * eligible zone has failed zone_reclaim recently.
2076 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2077 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2080 ret = zone_reclaim(zone, gfp_mask, order);
2082 case ZONE_RECLAIM_NOSCAN:
2085 case ZONE_RECLAIM_FULL:
2086 /* scanned but unreclaimable */
2089 /* did we reclaim enough */
2090 if (zone_watermark_ok(zone, order, mark,
2091 classzone_idx, alloc_flags))
2095 * Failed to reclaim enough to meet watermark.
2096 * Only mark the zone full if checking the min
2097 * watermark or if we failed to reclaim just
2098 * 1<<order pages or else the page allocator
2099 * fastpath will prematurely mark zones full
2100 * when the watermark is between the low and
2103 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2104 ret == ZONE_RECLAIM_SOME)
2105 goto this_zone_full;
2112 page = buffered_rmqueue(preferred_zone, zone, order,
2113 gfp_mask, migratetype);
2117 if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
2118 zlc_mark_zone_full(zonelist, z);
2123 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
2124 * necessary to allocate the page. The expectation is
2125 * that the caller is taking steps that will free more
2126 * memory. The caller should avoid the page being used
2127 * for !PFMEMALLOC purposes.
2129 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
2134 * The first pass makes sure allocations are spread fairly within the
2135 * local node. However, the local node might have free pages left
2136 * after the fairness batches are exhausted, and remote zones haven't
2137 * even been considered yet. Try once more without fairness, and
2138 * include remote zones now, before entering the slowpath and waking
2139 * kswapd: prefer spilling to a remote zone over swapping locally.
2141 if (alloc_flags & ALLOC_FAIR) {
2142 alloc_flags &= ~ALLOC_FAIR;
2143 if (nr_fair_skipped) {
2144 zonelist_rescan = true;
2145 reset_alloc_batches(preferred_zone);
2147 if (nr_online_nodes > 1)
2148 zonelist_rescan = true;
2151 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) {
2152 /* Disable zlc cache for second zonelist scan */
2154 zonelist_rescan = true;
2157 if (zonelist_rescan)
2164 * Large machines with many possible nodes should not always dump per-node
2165 * meminfo in irq context.
2167 static inline bool should_suppress_show_mem(void)
2172 ret = in_interrupt();
2177 static DEFINE_RATELIMIT_STATE(nopage_rs,
2178 DEFAULT_RATELIMIT_INTERVAL,
2179 DEFAULT_RATELIMIT_BURST);
2181 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2183 unsigned int filter = SHOW_MEM_FILTER_NODES;
2185 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2186 debug_guardpage_minorder() > 0)
2190 * This documents exceptions given to allocations in certain
2191 * contexts that are allowed to allocate outside current's set
2194 if (!(gfp_mask & __GFP_NOMEMALLOC))
2195 if (test_thread_flag(TIF_MEMDIE) ||
2196 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2197 filter &= ~SHOW_MEM_FILTER_NODES;
2198 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2199 filter &= ~SHOW_MEM_FILTER_NODES;
2202 struct va_format vaf;
2205 va_start(args, fmt);
2210 pr_warn("%pV", &vaf);
2215 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2216 current->comm, order, gfp_mask);
2219 if (!should_suppress_show_mem())
2224 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2225 unsigned long did_some_progress,
2226 unsigned long pages_reclaimed)
2228 /* Do not loop if specifically requested */
2229 if (gfp_mask & __GFP_NORETRY)
2232 /* Always retry if specifically requested */
2233 if (gfp_mask & __GFP_NOFAIL)
2237 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2238 * making forward progress without invoking OOM. Suspend also disables
2239 * storage devices so kswapd will not help. Bail if we are suspending.
2241 if (!did_some_progress && pm_suspended_storage())
2245 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2246 * means __GFP_NOFAIL, but that may not be true in other
2249 if (order <= PAGE_ALLOC_COSTLY_ORDER)
2253 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2254 * specified, then we retry until we no longer reclaim any pages
2255 * (above), or we've reclaimed an order of pages at least as
2256 * large as the allocation's order. In both cases, if the
2257 * allocation still fails, we stop retrying.
2259 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
2265 static inline struct page *
2266 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2267 struct zonelist *zonelist, enum zone_type high_zoneidx,
2268 nodemask_t *nodemask, struct zone *preferred_zone,
2269 int classzone_idx, int migratetype)
2273 /* Acquire the per-zone oom lock for each zone */
2274 if (!oom_zonelist_trylock(zonelist, gfp_mask)) {
2275 schedule_timeout_uninterruptible(1);
2280 * PM-freezer should be notified that there might be an OOM killer on
2281 * its way to kill and wake somebody up. This is too early and we might
2282 * end up not killing anything but false positives are acceptable.
2283 * See freeze_processes.
2288 * Go through the zonelist yet one more time, keep very high watermark
2289 * here, this is only to catch a parallel oom killing, we must fail if
2290 * we're still under heavy pressure.
2292 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
2293 order, zonelist, high_zoneidx,
2294 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2295 preferred_zone, classzone_idx, migratetype);
2299 if (!(gfp_mask & __GFP_NOFAIL)) {
2300 /* The OOM killer will not help higher order allocs */
2301 if (order > PAGE_ALLOC_COSTLY_ORDER)
2303 /* The OOM killer does not needlessly kill tasks for lowmem */
2304 if (high_zoneidx < ZONE_NORMAL)
2307 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2308 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2309 * The caller should handle page allocation failure by itself if
2310 * it specifies __GFP_THISNODE.
2311 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2313 if (gfp_mask & __GFP_THISNODE)
2316 /* Exhausted what can be done so it's blamo time */
2317 out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2320 oom_zonelist_unlock(zonelist, gfp_mask);
2324 #ifdef CONFIG_COMPACTION
2325 /* Try memory compaction for high-order allocations before reclaim */
2326 static struct page *
2327 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2328 struct zonelist *zonelist, enum zone_type high_zoneidx,
2329 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2330 int classzone_idx, int migratetype, enum migrate_mode mode,
2331 int *contended_compaction, bool *deferred_compaction)
2333 unsigned long compact_result;
2339 current->flags |= PF_MEMALLOC;
2340 compact_result = try_to_compact_pages(zonelist, order, gfp_mask,
2342 contended_compaction,
2343 alloc_flags, classzone_idx);
2344 current->flags &= ~PF_MEMALLOC;
2346 switch (compact_result) {
2347 case COMPACT_DEFERRED:
2348 *deferred_compaction = true;
2350 case COMPACT_SKIPPED:
2357 * At least in one zone compaction wasn't deferred or skipped, so let's
2358 * count a compaction stall
2360 count_vm_event(COMPACTSTALL);
2362 /* Page migration frees to the PCP lists but we want merging */
2363 drain_pages(get_cpu());
2366 page = get_page_from_freelist(gfp_mask, nodemask,
2367 order, zonelist, high_zoneidx,
2368 alloc_flags & ~ALLOC_NO_WATERMARKS,
2369 preferred_zone, classzone_idx, migratetype);
2372 struct zone *zone = page_zone(page);
2374 zone->compact_blockskip_flush = false;
2375 compaction_defer_reset(zone, order, true);
2376 count_vm_event(COMPACTSUCCESS);
2381 * It's bad if compaction run occurs and fails. The most likely reason
2382 * is that pages exist, but not enough to satisfy watermarks.
2384 count_vm_event(COMPACTFAIL);
2391 static inline struct page *
2392 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2393 struct zonelist *zonelist, enum zone_type high_zoneidx,
2394 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2395 int classzone_idx, int migratetype, enum migrate_mode mode,
2396 int *contended_compaction, bool *deferred_compaction)
2400 #endif /* CONFIG_COMPACTION */
2402 /* Perform direct synchronous page reclaim */
2404 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
2405 nodemask_t *nodemask)
2407 struct reclaim_state reclaim_state;
2412 /* We now go into synchronous reclaim */
2413 cpuset_memory_pressure_bump();
2414 current->flags |= PF_MEMALLOC;
2415 lockdep_set_current_reclaim_state(gfp_mask);
2416 reclaim_state.reclaimed_slab = 0;
2417 current->reclaim_state = &reclaim_state;
2419 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2421 current->reclaim_state = NULL;
2422 lockdep_clear_current_reclaim_state();
2423 current->flags &= ~PF_MEMALLOC;
2430 /* The really slow allocator path where we enter direct reclaim */
2431 static inline struct page *
2432 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2433 struct zonelist *zonelist, enum zone_type high_zoneidx,
2434 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2435 int classzone_idx, int migratetype, unsigned long *did_some_progress)
2437 struct page *page = NULL;
2438 bool drained = false;
2440 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
2442 if (unlikely(!(*did_some_progress)))
2445 /* After successful reclaim, reconsider all zones for allocation */
2446 if (IS_ENABLED(CONFIG_NUMA))
2447 zlc_clear_zones_full(zonelist);
2450 page = get_page_from_freelist(gfp_mask, nodemask, order,
2451 zonelist, high_zoneidx,
2452 alloc_flags & ~ALLOC_NO_WATERMARKS,
2453 preferred_zone, classzone_idx,
2457 * If an allocation failed after direct reclaim, it could be because
2458 * pages are pinned on the per-cpu lists. Drain them and try again
2460 if (!page && !drained) {
2461 drain_all_pages(NULL);
2470 * This is called in the allocator slow-path if the allocation request is of
2471 * sufficient urgency to ignore watermarks and take other desperate measures
2473 static inline struct page *
2474 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2475 struct zonelist *zonelist, enum zone_type high_zoneidx,
2476 nodemask_t *nodemask, struct zone *preferred_zone,
2477 int classzone_idx, int migratetype)
2482 page = get_page_from_freelist(gfp_mask, nodemask, order,
2483 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2484 preferred_zone, classzone_idx, migratetype);
2486 if (!page && gfp_mask & __GFP_NOFAIL)
2487 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2488 } while (!page && (gfp_mask & __GFP_NOFAIL));
2493 static void wake_all_kswapds(unsigned int order,
2494 struct zonelist *zonelist,
2495 enum zone_type high_zoneidx,
2496 struct zone *preferred_zone,
2497 nodemask_t *nodemask)
2502 for_each_zone_zonelist_nodemask(zone, z, zonelist,
2503 high_zoneidx, nodemask)
2504 wakeup_kswapd(zone, order, zone_idx(preferred_zone));
2508 gfp_to_alloc_flags(gfp_t gfp_mask)
2510 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2511 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
2513 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2514 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2517 * The caller may dip into page reserves a bit more if the caller
2518 * cannot run direct reclaim, or if the caller has realtime scheduling
2519 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2520 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2522 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2526 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2527 * if it can't schedule.
2529 if (!(gfp_mask & __GFP_NOMEMALLOC))
2530 alloc_flags |= ALLOC_HARDER;
2532 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2533 * comment for __cpuset_node_allowed_softwall().
2535 alloc_flags &= ~ALLOC_CPUSET;
2536 } else if (unlikely(rt_task(current)) && !in_interrupt())
2537 alloc_flags |= ALLOC_HARDER;
2539 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2540 if (gfp_mask & __GFP_MEMALLOC)
2541 alloc_flags |= ALLOC_NO_WATERMARKS;
2542 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2543 alloc_flags |= ALLOC_NO_WATERMARKS;
2544 else if (!in_interrupt() &&
2545 ((current->flags & PF_MEMALLOC) ||
2546 unlikely(test_thread_flag(TIF_MEMDIE))))
2547 alloc_flags |= ALLOC_NO_WATERMARKS;
2550 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2551 alloc_flags |= ALLOC_CMA;
2556 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2558 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2561 static inline struct page *
2562 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2563 struct zonelist *zonelist, enum zone_type high_zoneidx,
2564 nodemask_t *nodemask, struct zone *preferred_zone,
2565 int classzone_idx, int migratetype)
2567 const gfp_t wait = gfp_mask & __GFP_WAIT;
2568 struct page *page = NULL;
2570 unsigned long pages_reclaimed = 0;
2571 unsigned long did_some_progress;
2572 enum migrate_mode migration_mode = MIGRATE_ASYNC;
2573 bool deferred_compaction = false;
2574 int contended_compaction = COMPACT_CONTENDED_NONE;
2577 * In the slowpath, we sanity check order to avoid ever trying to
2578 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2579 * be using allocators in order of preference for an area that is
2582 if (order >= MAX_ORDER) {
2583 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2588 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2589 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2590 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2591 * using a larger set of nodes after it has established that the
2592 * allowed per node queues are empty and that nodes are
2595 if (IS_ENABLED(CONFIG_NUMA) &&
2596 (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2600 if (!(gfp_mask & __GFP_NO_KSWAPD))
2601 wake_all_kswapds(order, zonelist, high_zoneidx,
2602 preferred_zone, nodemask);
2605 * OK, we're below the kswapd watermark and have kicked background
2606 * reclaim. Now things get more complex, so set up alloc_flags according
2607 * to how we want to proceed.
2609 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2612 * Find the true preferred zone if the allocation is unconstrained by
2615 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) {
2616 struct zoneref *preferred_zoneref;
2617 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
2618 NULL, &preferred_zone);
2619 classzone_idx = zonelist_zone_idx(preferred_zoneref);
2623 /* This is the last chance, in general, before the goto nopage. */
2624 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2625 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2626 preferred_zone, classzone_idx, migratetype);
2630 /* Allocate without watermarks if the context allows */
2631 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2633 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2634 * the allocation is high priority and these type of
2635 * allocations are system rather than user orientated
2637 zonelist = node_zonelist(numa_node_id(), gfp_mask);
2639 page = __alloc_pages_high_priority(gfp_mask, order,
2640 zonelist, high_zoneidx, nodemask,
2641 preferred_zone, classzone_idx, migratetype);
2647 /* Atomic allocations - we can't balance anything */
2650 * All existing users of the deprecated __GFP_NOFAIL are
2651 * blockable, so warn of any new users that actually allow this
2652 * type of allocation to fail.
2654 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
2658 /* Avoid recursion of direct reclaim */
2659 if (current->flags & PF_MEMALLOC)
2662 /* Avoid allocations with no watermarks from looping endlessly */
2663 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2667 * Try direct compaction. The first pass is asynchronous. Subsequent
2668 * attempts after direct reclaim are synchronous
2670 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
2671 high_zoneidx, nodemask, alloc_flags,
2673 classzone_idx, migratetype,
2674 migration_mode, &contended_compaction,
2675 &deferred_compaction);
2679 /* Checks for THP-specific high-order allocations */
2680 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) {
2682 * If compaction is deferred for high-order allocations, it is
2683 * because sync compaction recently failed. If this is the case
2684 * and the caller requested a THP allocation, we do not want
2685 * to heavily disrupt the system, so we fail the allocation
2686 * instead of entering direct reclaim.
2688 if (deferred_compaction)
2692 * In all zones where compaction was attempted (and not
2693 * deferred or skipped), lock contention has been detected.
2694 * For THP allocation we do not want to disrupt the others
2695 * so we fallback to base pages instead.
2697 if (contended_compaction == COMPACT_CONTENDED_LOCK)
2701 * If compaction was aborted due to need_resched(), we do not
2702 * want to further increase allocation latency, unless it is
2703 * khugepaged trying to collapse.
2705 if (contended_compaction == COMPACT_CONTENDED_SCHED
2706 && !(current->flags & PF_KTHREAD))
2711 * It can become very expensive to allocate transparent hugepages at
2712 * fault, so use asynchronous memory compaction for THP unless it is
2713 * khugepaged trying to collapse.
2715 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE ||
2716 (current->flags & PF_KTHREAD))
2717 migration_mode = MIGRATE_SYNC_LIGHT;
2719 /* Try direct reclaim and then allocating */
2720 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2721 zonelist, high_zoneidx,
2723 alloc_flags, preferred_zone,
2724 classzone_idx, migratetype,
2725 &did_some_progress);
2730 * If we failed to make any progress reclaiming, then we are
2731 * running out of options and have to consider going OOM
2733 if (!did_some_progress) {
2734 if (oom_gfp_allowed(gfp_mask)) {
2735 if (oom_killer_disabled)
2737 /* Coredumps can quickly deplete all memory reserves */
2738 if ((current->flags & PF_DUMPCORE) &&
2739 !(gfp_mask & __GFP_NOFAIL))
2741 page = __alloc_pages_may_oom(gfp_mask, order,
2742 zonelist, high_zoneidx,
2743 nodemask, preferred_zone,
2744 classzone_idx, migratetype);
2748 if (!(gfp_mask & __GFP_NOFAIL)) {
2750 * The oom killer is not called for high-order
2751 * allocations that may fail, so if no progress
2752 * is being made, there are no other options and
2753 * retrying is unlikely to help.
2755 if (order > PAGE_ALLOC_COSTLY_ORDER)
2758 * The oom killer is not called for lowmem
2759 * allocations to prevent needlessly killing
2762 if (high_zoneidx < ZONE_NORMAL)
2770 /* Check if we should retry the allocation */
2771 pages_reclaimed += did_some_progress;
2772 if (should_alloc_retry(gfp_mask, order, did_some_progress,
2774 /* Wait for some write requests to complete then retry */
2775 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2779 * High-order allocations do not necessarily loop after
2780 * direct reclaim and reclaim/compaction depends on compaction
2781 * being called after reclaim so call directly if necessary
2783 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
2784 high_zoneidx, nodemask, alloc_flags,
2786 classzone_idx, migratetype,
2787 migration_mode, &contended_compaction,
2788 &deferred_compaction);
2794 warn_alloc_failed(gfp_mask, order, NULL);
2797 if (kmemcheck_enabled)
2798 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2804 * This is the 'heart' of the zoned buddy allocator.
2807 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2808 struct zonelist *zonelist, nodemask_t *nodemask)
2810 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2811 struct zone *preferred_zone;
2812 struct zoneref *preferred_zoneref;
2813 struct page *page = NULL;
2814 int migratetype = gfpflags_to_migratetype(gfp_mask);
2815 unsigned int cpuset_mems_cookie;
2816 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
2819 gfp_mask &= gfp_allowed_mask;
2821 lockdep_trace_alloc(gfp_mask);
2823 might_sleep_if(gfp_mask & __GFP_WAIT);
2825 if (should_fail_alloc_page(gfp_mask, order))
2829 * Check the zones suitable for the gfp_mask contain at least one
2830 * valid zone. It's possible to have an empty zonelist as a result
2831 * of GFP_THISNODE and a memoryless node
2833 if (unlikely(!zonelist->_zonerefs->zone))
2836 if (IS_ENABLED(CONFIG_CMA) && migratetype == MIGRATE_MOVABLE)
2837 alloc_flags |= ALLOC_CMA;
2840 cpuset_mems_cookie = read_mems_allowed_begin();
2842 /* The preferred zone is used for statistics later */
2843 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
2844 nodemask ? : &cpuset_current_mems_allowed,
2846 if (!preferred_zone)
2848 classzone_idx = zonelist_zone_idx(preferred_zoneref);
2850 /* First allocation attempt */
2851 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2852 zonelist, high_zoneidx, alloc_flags,
2853 preferred_zone, classzone_idx, migratetype);
2854 if (unlikely(!page)) {
2856 * Runtime PM, block IO and its error handling path
2857 * can deadlock because I/O on the device might not
2860 gfp_mask = memalloc_noio_flags(gfp_mask);
2861 page = __alloc_pages_slowpath(gfp_mask, order,
2862 zonelist, high_zoneidx, nodemask,
2863 preferred_zone, classzone_idx, migratetype);
2866 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2870 * When updating a task's mems_allowed, it is possible to race with
2871 * parallel threads in such a way that an allocation can fail while
2872 * the mask is being updated. If a page allocation is about to fail,
2873 * check if the cpuset changed during allocation and if so, retry.
2875 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2880 EXPORT_SYMBOL(__alloc_pages_nodemask);
2883 * Common helper functions.
2885 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2890 * __get_free_pages() returns a 32-bit address, which cannot represent
2893 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2895 page = alloc_pages(gfp_mask, order);
2898 return (unsigned long) page_address(page);
2900 EXPORT_SYMBOL(__get_free_pages);
2902 unsigned long get_zeroed_page(gfp_t gfp_mask)
2904 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2906 EXPORT_SYMBOL(get_zeroed_page);
2908 void __free_pages(struct page *page, unsigned int order)
2910 if (put_page_testzero(page)) {
2912 free_hot_cold_page(page, false);
2914 __free_pages_ok(page, order);
2918 EXPORT_SYMBOL(__free_pages);
2920 void free_pages(unsigned long addr, unsigned int order)
2923 VM_BUG_ON(!virt_addr_valid((void *)addr));
2924 __free_pages(virt_to_page((void *)addr), order);
2928 EXPORT_SYMBOL(free_pages);
2931 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
2932 * of the current memory cgroup.
2934 * It should be used when the caller would like to use kmalloc, but since the
2935 * allocation is large, it has to fall back to the page allocator.
2937 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
2940 struct mem_cgroup *memcg = NULL;
2942 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2944 page = alloc_pages(gfp_mask, order);
2945 memcg_kmem_commit_charge(page, memcg, order);
2949 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
2952 struct mem_cgroup *memcg = NULL;
2954 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2956 page = alloc_pages_node(nid, gfp_mask, order);
2957 memcg_kmem_commit_charge(page, memcg, order);
2962 * __free_kmem_pages and free_kmem_pages will free pages allocated with
2965 void __free_kmem_pages(struct page *page, unsigned int order)
2967 memcg_kmem_uncharge_pages(page, order);
2968 __free_pages(page, order);
2971 void free_kmem_pages(unsigned long addr, unsigned int order)
2974 VM_BUG_ON(!virt_addr_valid((void *)addr));
2975 __free_kmem_pages(virt_to_page((void *)addr), order);
2979 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2982 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2983 unsigned long used = addr + PAGE_ALIGN(size);
2985 split_page(virt_to_page((void *)addr), order);
2986 while (used < alloc_end) {
2991 return (void *)addr;
2995 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2996 * @size: the number of bytes to allocate
2997 * @gfp_mask: GFP flags for the allocation
2999 * This function is similar to alloc_pages(), except that it allocates the
3000 * minimum number of pages to satisfy the request. alloc_pages() can only
3001 * allocate memory in power-of-two pages.
3003 * This function is also limited by MAX_ORDER.
3005 * Memory allocated by this function must be released by free_pages_exact().
3007 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3009 unsigned int order = get_order(size);
3012 addr = __get_free_pages(gfp_mask, order);
3013 return make_alloc_exact(addr, order, size);
3015 EXPORT_SYMBOL(alloc_pages_exact);
3018 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3020 * @nid: the preferred node ID where memory should be allocated
3021 * @size: the number of bytes to allocate
3022 * @gfp_mask: GFP flags for the allocation
3024 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3026 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
3029 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3031 unsigned order = get_order(size);
3032 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3035 return make_alloc_exact((unsigned long)page_address(p), order, size);
3039 * free_pages_exact - release memory allocated via alloc_pages_exact()
3040 * @virt: the value returned by alloc_pages_exact.
3041 * @size: size of allocation, same value as passed to alloc_pages_exact().
3043 * Release the memory allocated by a previous call to alloc_pages_exact.
3045 void free_pages_exact(void *virt, size_t size)
3047 unsigned long addr = (unsigned long)virt;
3048 unsigned long end = addr + PAGE_ALIGN(size);
3050 while (addr < end) {
3055 EXPORT_SYMBOL(free_pages_exact);
3058 * nr_free_zone_pages - count number of pages beyond high watermark
3059 * @offset: The zone index of the highest zone
3061 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3062 * high watermark within all zones at or below a given zone index. For each
3063 * zone, the number of pages is calculated as:
3064 * managed_pages - high_pages
3066 static unsigned long nr_free_zone_pages(int offset)
3071 /* Just pick one node, since fallback list is circular */
3072 unsigned long sum = 0;
3074 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3076 for_each_zone_zonelist(zone, z, zonelist, offset) {
3077 unsigned long size = zone->managed_pages;
3078 unsigned long high = high_wmark_pages(zone);
3087 * nr_free_buffer_pages - count number of pages beyond high watermark
3089 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3090 * watermark within ZONE_DMA and ZONE_NORMAL.
3092 unsigned long nr_free_buffer_pages(void)
3094 return nr_free_zone_pages(gfp_zone(GFP_USER));
3096 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3099 * nr_free_pagecache_pages - count number of pages beyond high watermark
3101 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3102 * high watermark within all zones.
3104 unsigned long nr_free_pagecache_pages(void)
3106 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3109 static inline void show_node(struct zone *zone)
3111 if (IS_ENABLED(CONFIG_NUMA))
3112 printk("Node %d ", zone_to_nid(zone));
3115 void si_meminfo(struct sysinfo *val)
3117 val->totalram = totalram_pages;
3118 val->sharedram = global_page_state(NR_SHMEM);
3119 val->freeram = global_page_state(NR_FREE_PAGES);
3120 val->bufferram = nr_blockdev_pages();
3121 val->totalhigh = totalhigh_pages;
3122 val->freehigh = nr_free_highpages();
3123 val->mem_unit = PAGE_SIZE;
3126 EXPORT_SYMBOL(si_meminfo);
3129 void si_meminfo_node(struct sysinfo *val, int nid)
3131 int zone_type; /* needs to be signed */
3132 unsigned long managed_pages = 0;
3133 pg_data_t *pgdat = NODE_DATA(nid);
3135 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3136 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3137 val->totalram = managed_pages;
3138 val->sharedram = node_page_state(nid, NR_SHMEM);
3139 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3140 #ifdef CONFIG_HIGHMEM
3141 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3142 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3148 val->mem_unit = PAGE_SIZE;
3153 * Determine whether the node should be displayed or not, depending on whether
3154 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3156 bool skip_free_areas_node(unsigned int flags, int nid)
3159 unsigned int cpuset_mems_cookie;
3161 if (!(flags & SHOW_MEM_FILTER_NODES))
3165 cpuset_mems_cookie = read_mems_allowed_begin();
3166 ret = !node_isset(nid, cpuset_current_mems_allowed);
3167 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3172 #define K(x) ((x) << (PAGE_SHIFT-10))
3174 static void show_migration_types(unsigned char type)
3176 static const char types[MIGRATE_TYPES] = {
3177 [MIGRATE_UNMOVABLE] = 'U',
3178 [MIGRATE_RECLAIMABLE] = 'E',
3179 [MIGRATE_MOVABLE] = 'M',
3180 [MIGRATE_RESERVE] = 'R',
3182 [MIGRATE_CMA] = 'C',
3184 #ifdef CONFIG_MEMORY_ISOLATION
3185 [MIGRATE_ISOLATE] = 'I',
3188 char tmp[MIGRATE_TYPES + 1];
3192 for (i = 0; i < MIGRATE_TYPES; i++) {
3193 if (type & (1 << i))
3198 printk("(%s) ", tmp);
3202 * Show free area list (used inside shift_scroll-lock stuff)
3203 * We also calculate the percentage fragmentation. We do this by counting the
3204 * memory on each free list with the exception of the first item on the list.
3205 * Suppresses nodes that are not allowed by current's cpuset if
3206 * SHOW_MEM_FILTER_NODES is passed.
3208 void show_free_areas(unsigned int filter)
3213 for_each_populated_zone(zone) {
3214 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3217 printk("%s per-cpu:\n", zone->name);
3219 for_each_online_cpu(cpu) {
3220 struct per_cpu_pageset *pageset;
3222 pageset = per_cpu_ptr(zone->pageset, cpu);
3224 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
3225 cpu, pageset->pcp.high,
3226 pageset->pcp.batch, pageset->pcp.count);
3230 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3231 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3233 " dirty:%lu writeback:%lu unstable:%lu\n"
3234 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3235 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3237 global_page_state(NR_ACTIVE_ANON),
3238 global_page_state(NR_INACTIVE_ANON),
3239 global_page_state(NR_ISOLATED_ANON),
3240 global_page_state(NR_ACTIVE_FILE),
3241 global_page_state(NR_INACTIVE_FILE),
3242 global_page_state(NR_ISOLATED_FILE),
3243 global_page_state(NR_UNEVICTABLE),
3244 global_page_state(NR_FILE_DIRTY),
3245 global_page_state(NR_WRITEBACK),
3246 global_page_state(NR_UNSTABLE_NFS),
3247 global_page_state(NR_FREE_PAGES),
3248 global_page_state(NR_SLAB_RECLAIMABLE),
3249 global_page_state(NR_SLAB_UNRECLAIMABLE),
3250 global_page_state(NR_FILE_MAPPED),
3251 global_page_state(NR_SHMEM),
3252 global_page_state(NR_PAGETABLE),
3253 global_page_state(NR_BOUNCE),
3254 global_page_state(NR_FREE_CMA_PAGES));
3256 for_each_populated_zone(zone) {
3259 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3267 " active_anon:%lukB"
3268 " inactive_anon:%lukB"
3269 " active_file:%lukB"
3270 " inactive_file:%lukB"
3271 " unevictable:%lukB"
3272 " isolated(anon):%lukB"
3273 " isolated(file):%lukB"
3281 " slab_reclaimable:%lukB"
3282 " slab_unreclaimable:%lukB"
3283 " kernel_stack:%lukB"
3288 " writeback_tmp:%lukB"
3289 " pages_scanned:%lu"
3290 " all_unreclaimable? %s"
3293 K(zone_page_state(zone, NR_FREE_PAGES)),
3294 K(min_wmark_pages(zone)),
3295 K(low_wmark_pages(zone)),
3296 K(high_wmark_pages(zone)),
3297 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3298 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3299 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3300 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3301 K(zone_page_state(zone, NR_UNEVICTABLE)),
3302 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3303 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3304 K(zone->present_pages),
3305 K(zone->managed_pages),
3306 K(zone_page_state(zone, NR_MLOCK)),
3307 K(zone_page_state(zone, NR_FILE_DIRTY)),
3308 K(zone_page_state(zone, NR_WRITEBACK)),
3309 K(zone_page_state(zone, NR_FILE_MAPPED)),
3310 K(zone_page_state(zone, NR_SHMEM)),
3311 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3312 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3313 zone_page_state(zone, NR_KERNEL_STACK) *
3315 K(zone_page_state(zone, NR_PAGETABLE)),
3316 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3317 K(zone_page_state(zone, NR_BOUNCE)),
3318 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3319 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3320 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3321 (!zone_reclaimable(zone) ? "yes" : "no")
3323 printk("lowmem_reserve[]:");
3324 for (i = 0; i < MAX_NR_ZONES; i++)
3325 printk(" %ld", zone->lowmem_reserve[i]);
3329 for_each_populated_zone(zone) {
3330 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3331 unsigned char types[MAX_ORDER];
3333 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3336 printk("%s: ", zone->name);
3338 spin_lock_irqsave(&zone->lock, flags);
3339 for (order = 0; order < MAX_ORDER; order++) {
3340 struct free_area *area = &zone->free_area[order];
3343 nr[order] = area->nr_free;
3344 total += nr[order] << order;
3347 for (type = 0; type < MIGRATE_TYPES; type++) {
3348 if (!list_empty(&area->free_list[type]))
3349 types[order] |= 1 << type;
3352 spin_unlock_irqrestore(&zone->lock, flags);
3353 for (order = 0; order < MAX_ORDER; order++) {
3354 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3356 show_migration_types(types[order]);
3358 printk("= %lukB\n", K(total));
3361 hugetlb_show_meminfo();
3363 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3365 show_swap_cache_info();
3368 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3370 zoneref->zone = zone;
3371 zoneref->zone_idx = zone_idx(zone);
3375 * Builds allocation fallback zone lists.
3377 * Add all populated zones of a node to the zonelist.
3379 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3383 enum zone_type zone_type = MAX_NR_ZONES;
3387 zone = pgdat->node_zones + zone_type;
3388 if (populated_zone(zone)) {
3389 zoneref_set_zone(zone,
3390 &zonelist->_zonerefs[nr_zones++]);
3391 check_highest_zone(zone_type);
3393 } while (zone_type);
3401 * 0 = automatic detection of better ordering.
3402 * 1 = order by ([node] distance, -zonetype)
3403 * 2 = order by (-zonetype, [node] distance)
3405 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3406 * the same zonelist. So only NUMA can configure this param.
3408 #define ZONELIST_ORDER_DEFAULT 0
3409 #define ZONELIST_ORDER_NODE 1
3410 #define ZONELIST_ORDER_ZONE 2
3412 /* zonelist order in the kernel.
3413 * set_zonelist_order() will set this to NODE or ZONE.
3415 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3416 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3420 /* The value user specified ....changed by config */
3421 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3422 /* string for sysctl */
3423 #define NUMA_ZONELIST_ORDER_LEN 16
3424 char numa_zonelist_order[16] = "default";
3427 * interface for configure zonelist ordering.
3428 * command line option "numa_zonelist_order"
3429 * = "[dD]efault - default, automatic configuration.
3430 * = "[nN]ode - order by node locality, then by zone within node
3431 * = "[zZ]one - order by zone, then by locality within zone
3434 static int __parse_numa_zonelist_order(char *s)
3436 if (*s == 'd' || *s == 'D') {
3437 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3438 } else if (*s == 'n' || *s == 'N') {
3439 user_zonelist_order = ZONELIST_ORDER_NODE;
3440 } else if (*s == 'z' || *s == 'Z') {
3441 user_zonelist_order = ZONELIST_ORDER_ZONE;
3444 "Ignoring invalid numa_zonelist_order value: "
3451 static __init int setup_numa_zonelist_order(char *s)
3458 ret = __parse_numa_zonelist_order(s);
3460 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3464 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3467 * sysctl handler for numa_zonelist_order
3469 int numa_zonelist_order_handler(struct ctl_table *table, int write,
3470 void __user *buffer, size_t *length,
3473 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3475 static DEFINE_MUTEX(zl_order_mutex);
3477 mutex_lock(&zl_order_mutex);
3479 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3483 strcpy(saved_string, (char *)table->data);
3485 ret = proc_dostring(table, write, buffer, length, ppos);
3489 int oldval = user_zonelist_order;
3491 ret = __parse_numa_zonelist_order((char *)table->data);
3494 * bogus value. restore saved string
3496 strncpy((char *)table->data, saved_string,
3497 NUMA_ZONELIST_ORDER_LEN);
3498 user_zonelist_order = oldval;
3499 } else if (oldval != user_zonelist_order) {
3500 mutex_lock(&zonelists_mutex);
3501 build_all_zonelists(NULL, NULL);
3502 mutex_unlock(&zonelists_mutex);
3506 mutex_unlock(&zl_order_mutex);
3511 #define MAX_NODE_LOAD (nr_online_nodes)
3512 static int node_load[MAX_NUMNODES];
3515 * find_next_best_node - find the next node that should appear in a given node's fallback list
3516 * @node: node whose fallback list we're appending
3517 * @used_node_mask: nodemask_t of already used nodes
3519 * We use a number of factors to determine which is the next node that should
3520 * appear on a given node's fallback list. The node should not have appeared
3521 * already in @node's fallback list, and it should be the next closest node
3522 * according to the distance array (which contains arbitrary distance values
3523 * from each node to each node in the system), and should also prefer nodes
3524 * with no CPUs, since presumably they'll have very little allocation pressure
3525 * on them otherwise.
3526 * It returns -1 if no node is found.
3528 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3531 int min_val = INT_MAX;
3532 int best_node = NUMA_NO_NODE;
3533 const struct cpumask *tmp = cpumask_of_node(0);
3535 /* Use the local node if we haven't already */
3536 if (!node_isset(node, *used_node_mask)) {
3537 node_set(node, *used_node_mask);
3541 for_each_node_state(n, N_MEMORY) {
3543 /* Don't want a node to appear more than once */
3544 if (node_isset(n, *used_node_mask))
3547 /* Use the distance array to find the distance */
3548 val = node_distance(node, n);
3550 /* Penalize nodes under us ("prefer the next node") */
3553 /* Give preference to headless and unused nodes */
3554 tmp = cpumask_of_node(n);
3555 if (!cpumask_empty(tmp))
3556 val += PENALTY_FOR_NODE_WITH_CPUS;
3558 /* Slight preference for less loaded node */
3559 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3560 val += node_load[n];
3562 if (val < min_val) {
3569 node_set(best_node, *used_node_mask);
3576 * Build zonelists ordered by node and zones within node.
3577 * This results in maximum locality--normal zone overflows into local
3578 * DMA zone, if any--but risks exhausting DMA zone.
3580 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3583 struct zonelist *zonelist;
3585 zonelist = &pgdat->node_zonelists[0];
3586 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3588 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3589 zonelist->_zonerefs[j].zone = NULL;
3590 zonelist->_zonerefs[j].zone_idx = 0;
3594 * Build gfp_thisnode zonelists
3596 static void build_thisnode_zonelists(pg_data_t *pgdat)
3599 struct zonelist *zonelist;
3601 zonelist = &pgdat->node_zonelists[1];
3602 j = build_zonelists_node(pgdat, zonelist, 0);
3603 zonelist->_zonerefs[j].zone = NULL;
3604 zonelist->_zonerefs[j].zone_idx = 0;
3608 * Build zonelists ordered by zone and nodes within zones.
3609 * This results in conserving DMA zone[s] until all Normal memory is
3610 * exhausted, but results in overflowing to remote node while memory
3611 * may still exist in local DMA zone.
3613 static int node_order[MAX_NUMNODES];
3615 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3618 int zone_type; /* needs to be signed */
3620 struct zonelist *zonelist;
3622 zonelist = &pgdat->node_zonelists[0];
3624 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3625 for (j = 0; j < nr_nodes; j++) {
3626 node = node_order[j];
3627 z = &NODE_DATA(node)->node_zones[zone_type];
3628 if (populated_zone(z)) {
3630 &zonelist->_zonerefs[pos++]);
3631 check_highest_zone(zone_type);
3635 zonelist->_zonerefs[pos].zone = NULL;
3636 zonelist->_zonerefs[pos].zone_idx = 0;
3639 #if defined(CONFIG_64BIT)
3641 * Devices that require DMA32/DMA are relatively rare and do not justify a
3642 * penalty to every machine in case the specialised case applies. Default
3643 * to Node-ordering on 64-bit NUMA machines
3645 static int default_zonelist_order(void)
3647 return ZONELIST_ORDER_NODE;
3651 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
3652 * by the kernel. If processes running on node 0 deplete the low memory zone
3653 * then reclaim will occur more frequency increasing stalls and potentially
3654 * be easier to OOM if a large percentage of the zone is under writeback or
3655 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
3656 * Hence, default to zone ordering on 32-bit.
3658 static int default_zonelist_order(void)
3660 return ZONELIST_ORDER_ZONE;
3662 #endif /* CONFIG_64BIT */
3664 static void set_zonelist_order(void)
3666 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3667 current_zonelist_order = default_zonelist_order();
3669 current_zonelist_order = user_zonelist_order;
3672 static void build_zonelists(pg_data_t *pgdat)
3676 nodemask_t used_mask;
3677 int local_node, prev_node;
3678 struct zonelist *zonelist;
3679 int order = current_zonelist_order;
3681 /* initialize zonelists */
3682 for (i = 0; i < MAX_ZONELISTS; i++) {
3683 zonelist = pgdat->node_zonelists + i;
3684 zonelist->_zonerefs[0].zone = NULL;
3685 zonelist->_zonerefs[0].zone_idx = 0;
3688 /* NUMA-aware ordering of nodes */
3689 local_node = pgdat->node_id;
3690 load = nr_online_nodes;
3691 prev_node = local_node;
3692 nodes_clear(used_mask);
3694 memset(node_order, 0, sizeof(node_order));
3697 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3699 * We don't want to pressure a particular node.
3700 * So adding penalty to the first node in same
3701 * distance group to make it round-robin.
3703 if (node_distance(local_node, node) !=
3704 node_distance(local_node, prev_node))
3705 node_load[node] = load;
3709 if (order == ZONELIST_ORDER_NODE)
3710 build_zonelists_in_node_order(pgdat, node);
3712 node_order[j++] = node; /* remember order */
3715 if (order == ZONELIST_ORDER_ZONE) {
3716 /* calculate node order -- i.e., DMA last! */
3717 build_zonelists_in_zone_order(pgdat, j);
3720 build_thisnode_zonelists(pgdat);
3723 /* Construct the zonelist performance cache - see further mmzone.h */
3724 static void build_zonelist_cache(pg_data_t *pgdat)
3726 struct zonelist *zonelist;
3727 struct zonelist_cache *zlc;
3730 zonelist = &pgdat->node_zonelists[0];
3731 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3732 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3733 for (z = zonelist->_zonerefs; z->zone; z++)
3734 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3737 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3739 * Return node id of node used for "local" allocations.
3740 * I.e., first node id of first zone in arg node's generic zonelist.
3741 * Used for initializing percpu 'numa_mem', which is used primarily
3742 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3744 int local_memory_node(int node)
3748 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3749 gfp_zone(GFP_KERNEL),
3756 #else /* CONFIG_NUMA */
3758 static void set_zonelist_order(void)
3760 current_zonelist_order = ZONELIST_ORDER_ZONE;
3763 static void build_zonelists(pg_data_t *pgdat)
3765 int node, local_node;
3767 struct zonelist *zonelist;
3769 local_node = pgdat->node_id;
3771 zonelist = &pgdat->node_zonelists[0];
3772 j = build_zonelists_node(pgdat, zonelist, 0);
3775 * Now we build the zonelist so that it contains the zones
3776 * of all the other nodes.
3777 * We don't want to pressure a particular node, so when
3778 * building the zones for node N, we make sure that the
3779 * zones coming right after the local ones are those from
3780 * node N+1 (modulo N)
3782 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3783 if (!node_online(node))
3785 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3787 for (node = 0; node < local_node; node++) {
3788 if (!node_online(node))
3790 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3793 zonelist->_zonerefs[j].zone = NULL;
3794 zonelist->_zonerefs[j].zone_idx = 0;
3797 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3798 static void build_zonelist_cache(pg_data_t *pgdat)
3800 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3803 #endif /* CONFIG_NUMA */
3806 * Boot pageset table. One per cpu which is going to be used for all
3807 * zones and all nodes. The parameters will be set in such a way
3808 * that an item put on a list will immediately be handed over to
3809 * the buddy list. This is safe since pageset manipulation is done
3810 * with interrupts disabled.
3812 * The boot_pagesets must be kept even after bootup is complete for
3813 * unused processors and/or zones. They do play a role for bootstrapping
3814 * hotplugged processors.
3816 * zoneinfo_show() and maybe other functions do
3817 * not check if the processor is online before following the pageset pointer.
3818 * Other parts of the kernel may not check if the zone is available.
3820 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3821 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3822 static void setup_zone_pageset(struct zone *zone);
3825 * Global mutex to protect against size modification of zonelists
3826 * as well as to serialize pageset setup for the new populated zone.
3828 DEFINE_MUTEX(zonelists_mutex);
3830 /* return values int ....just for stop_machine() */
3831 static int __build_all_zonelists(void *data)
3835 pg_data_t *self = data;
3838 memset(node_load, 0, sizeof(node_load));
3841 if (self && !node_online(self->node_id)) {
3842 build_zonelists(self);
3843 build_zonelist_cache(self);
3846 for_each_online_node(nid) {
3847 pg_data_t *pgdat = NODE_DATA(nid);
3849 build_zonelists(pgdat);
3850 build_zonelist_cache(pgdat);
3854 * Initialize the boot_pagesets that are going to be used
3855 * for bootstrapping processors. The real pagesets for
3856 * each zone will be allocated later when the per cpu
3857 * allocator is available.
3859 * boot_pagesets are used also for bootstrapping offline
3860 * cpus if the system is already booted because the pagesets
3861 * are needed to initialize allocators on a specific cpu too.
3862 * F.e. the percpu allocator needs the page allocator which
3863 * needs the percpu allocator in order to allocate its pagesets
3864 * (a chicken-egg dilemma).
3866 for_each_possible_cpu(cpu) {
3867 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3869 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3871 * We now know the "local memory node" for each node--
3872 * i.e., the node of the first zone in the generic zonelist.
3873 * Set up numa_mem percpu variable for on-line cpus. During
3874 * boot, only the boot cpu should be on-line; we'll init the
3875 * secondary cpus' numa_mem as they come on-line. During
3876 * node/memory hotplug, we'll fixup all on-line cpus.
3878 if (cpu_online(cpu))
3879 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3887 * Called with zonelists_mutex held always
3888 * unless system_state == SYSTEM_BOOTING.
3890 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3892 set_zonelist_order();
3894 if (system_state == SYSTEM_BOOTING) {
3895 __build_all_zonelists(NULL);
3896 mminit_verify_zonelist();
3897 cpuset_init_current_mems_allowed();
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, totalpages = 0;
4722 for (i = 0; i < MAX_NR_ZONES; i++)
4723 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4727 pgdat->node_spanned_pages = totalpages;
4729 realtotalpages = totalpages;
4730 for (i = 0; i < MAX_NR_ZONES; i++)
4732 zone_absent_pages_in_node(pgdat->node_id, i,
4733 node_start_pfn, node_end_pfn,
4735 pgdat->node_present_pages = realtotalpages;
4736 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4740 #ifndef CONFIG_SPARSEMEM
4742 * Calculate the size of the zone->blockflags rounded to an unsigned long
4743 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4744 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4745 * round what is now in bits to nearest long in bits, then return it in
4748 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4750 unsigned long usemapsize;
4752 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4753 usemapsize = roundup(zonesize, pageblock_nr_pages);
4754 usemapsize = usemapsize >> pageblock_order;
4755 usemapsize *= NR_PAGEBLOCK_BITS;
4756 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4758 return usemapsize / 8;
4761 static void __init setup_usemap(struct pglist_data *pgdat,
4763 unsigned long zone_start_pfn,
4764 unsigned long zonesize)
4766 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4767 zone->pageblock_flags = NULL;
4769 zone->pageblock_flags =
4770 memblock_virt_alloc_node_nopanic(usemapsize,
4774 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4775 unsigned long zone_start_pfn, unsigned long zonesize) {}
4776 #endif /* CONFIG_SPARSEMEM */
4778 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4780 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4781 void __paginginit set_pageblock_order(void)
4785 /* Check that pageblock_nr_pages has not already been setup */
4786 if (pageblock_order)
4789 if (HPAGE_SHIFT > PAGE_SHIFT)
4790 order = HUGETLB_PAGE_ORDER;
4792 order = MAX_ORDER - 1;
4795 * Assume the largest contiguous order of interest is a huge page.
4796 * This value may be variable depending on boot parameters on IA64 and
4799 pageblock_order = order;
4801 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4804 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4805 * is unused as pageblock_order is set at compile-time. See
4806 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4809 void __paginginit set_pageblock_order(void)
4813 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4815 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
4816 unsigned long present_pages)
4818 unsigned long pages = spanned_pages;
4821 * Provide a more accurate estimation if there are holes within
4822 * the zone and SPARSEMEM is in use. If there are holes within the
4823 * zone, each populated memory region may cost us one or two extra
4824 * memmap pages due to alignment because memmap pages for each
4825 * populated regions may not naturally algined on page boundary.
4826 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4828 if (spanned_pages > present_pages + (present_pages >> 4) &&
4829 IS_ENABLED(CONFIG_SPARSEMEM))
4830 pages = present_pages;
4832 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
4836 * Set up the zone data structures:
4837 * - mark all pages reserved
4838 * - mark all memory queues empty
4839 * - clear the memory bitmaps
4841 * NOTE: pgdat should get zeroed by caller.
4843 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4844 unsigned long node_start_pfn, unsigned long node_end_pfn,
4845 unsigned long *zones_size, unsigned long *zholes_size)
4848 int nid = pgdat->node_id;
4849 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4852 pgdat_resize_init(pgdat);
4853 #ifdef CONFIG_NUMA_BALANCING
4854 spin_lock_init(&pgdat->numabalancing_migrate_lock);
4855 pgdat->numabalancing_migrate_nr_pages = 0;
4856 pgdat->numabalancing_migrate_next_window = jiffies;
4858 init_waitqueue_head(&pgdat->kswapd_wait);
4859 init_waitqueue_head(&pgdat->pfmemalloc_wait);
4860 pgdat_page_cgroup_init(pgdat);
4862 for (j = 0; j < MAX_NR_ZONES; j++) {
4863 struct zone *zone = pgdat->node_zones + j;
4864 unsigned long size, realsize, freesize, memmap_pages;
4866 size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
4867 node_end_pfn, zones_size);
4868 realsize = freesize = size - zone_absent_pages_in_node(nid, j,
4874 * Adjust freesize so that it accounts for how much memory
4875 * is used by this zone for memmap. This affects the watermark
4876 * and per-cpu initialisations
4878 memmap_pages = calc_memmap_size(size, realsize);
4879 if (freesize >= memmap_pages) {
4880 freesize -= memmap_pages;
4883 " %s zone: %lu pages used for memmap\n",
4884 zone_names[j], memmap_pages);
4887 " %s zone: %lu pages exceeds freesize %lu\n",
4888 zone_names[j], memmap_pages, freesize);
4890 /* Account for reserved pages */
4891 if (j == 0 && freesize > dma_reserve) {
4892 freesize -= dma_reserve;
4893 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4894 zone_names[0], dma_reserve);
4897 if (!is_highmem_idx(j))
4898 nr_kernel_pages += freesize;
4899 /* Charge for highmem memmap if there are enough kernel pages */
4900 else if (nr_kernel_pages > memmap_pages * 2)
4901 nr_kernel_pages -= memmap_pages;
4902 nr_all_pages += freesize;
4904 zone->spanned_pages = size;
4905 zone->present_pages = realsize;
4907 * Set an approximate value for lowmem here, it will be adjusted
4908 * when the bootmem allocator frees pages into the buddy system.
4909 * And all highmem pages will be managed by the buddy system.
4911 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
4914 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4916 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4918 zone->name = zone_names[j];
4919 spin_lock_init(&zone->lock);
4920 spin_lock_init(&zone->lru_lock);
4921 zone_seqlock_init(zone);
4922 zone->zone_pgdat = pgdat;
4923 zone_pcp_init(zone);
4925 /* For bootup, initialized properly in watermark setup */
4926 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
4928 lruvec_init(&zone->lruvec);
4932 set_pageblock_order();
4933 setup_usemap(pgdat, zone, zone_start_pfn, size);
4934 ret = init_currently_empty_zone(zone, zone_start_pfn,
4935 size, MEMMAP_EARLY);
4937 memmap_init(size, nid, j, zone_start_pfn);
4938 zone_start_pfn += size;
4942 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4944 /* Skip empty nodes */
4945 if (!pgdat->node_spanned_pages)
4948 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4949 /* ia64 gets its own node_mem_map, before this, without bootmem */
4950 if (!pgdat->node_mem_map) {
4951 unsigned long size, start, end;
4955 * The zone's endpoints aren't required to be MAX_ORDER
4956 * aligned but the node_mem_map endpoints must be in order
4957 * for the buddy allocator to function correctly.
4959 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4960 end = pgdat_end_pfn(pgdat);
4961 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4962 size = (end - start) * sizeof(struct page);
4963 map = alloc_remap(pgdat->node_id, size);
4965 map = memblock_virt_alloc_node_nopanic(size,
4967 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4969 #ifndef CONFIG_NEED_MULTIPLE_NODES
4971 * With no DISCONTIG, the global mem_map is just set as node 0's
4973 if (pgdat == NODE_DATA(0)) {
4974 mem_map = NODE_DATA(0)->node_mem_map;
4975 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4976 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4977 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4978 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4981 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4984 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4985 unsigned long node_start_pfn, unsigned long *zholes_size)
4987 pg_data_t *pgdat = NODE_DATA(nid);
4988 unsigned long start_pfn = 0;
4989 unsigned long end_pfn = 0;
4991 /* pg_data_t should be reset to zero when it's allocated */
4992 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4994 pgdat->node_id = nid;
4995 pgdat->node_start_pfn = node_start_pfn;
4996 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4997 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
4998 printk(KERN_INFO "Initmem setup node %d [mem %#010Lx-%#010Lx]\n", nid,
4999 (u64) start_pfn << PAGE_SHIFT, (u64) (end_pfn << PAGE_SHIFT) - 1);
5001 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5002 zones_size, zholes_size);
5004 alloc_node_mem_map(pgdat);
5005 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5006 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5007 nid, (unsigned long)pgdat,
5008 (unsigned long)pgdat->node_mem_map);
5011 free_area_init_core(pgdat, start_pfn, end_pfn,
5012 zones_size, zholes_size);
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 %0#10lx-%0#10lx]\n",
5372 arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT,
5373 (arch_zone_highest_possible_pfn[i]
5374 << PAGE_SHIFT) - 1);
5377 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5378 pr_info("Movable zone start for each node\n");
5379 for (i = 0; i < MAX_NUMNODES; i++) {
5380 if (zone_movable_pfn[i])
5381 pr_info(" Node %d: %#010lx\n", i,
5382 zone_movable_pfn[i] << PAGE_SHIFT);
5385 /* Print out the early node map */
5386 pr_info("Early memory node ranges\n");
5387 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5388 pr_info(" node %3d: [mem %#010lx-%#010lx]\n", nid,
5389 start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
5391 /* Initialise every node */
5392 mminit_verify_pageflags_layout();
5393 setup_nr_node_ids();
5394 for_each_online_node(nid) {
5395 pg_data_t *pgdat = NODE_DATA(nid);
5396 free_area_init_node(nid, NULL,
5397 find_min_pfn_for_node(nid), NULL);
5399 /* Any memory on that node */
5400 if (pgdat->node_present_pages)
5401 node_set_state(nid, N_MEMORY);
5402 check_for_memory(pgdat, nid);
5406 static int __init cmdline_parse_core(char *p, unsigned long *core)
5408 unsigned long long coremem;
5412 coremem = memparse(p, &p);
5413 *core = coremem >> PAGE_SHIFT;
5415 /* Paranoid check that UL is enough for the coremem value */
5416 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5422 * kernelcore=size sets the amount of memory for use for allocations that
5423 * cannot be reclaimed or migrated.
5425 static int __init cmdline_parse_kernelcore(char *p)
5427 return cmdline_parse_core(p, &required_kernelcore);
5431 * movablecore=size sets the amount of memory for use for allocations that
5432 * can be reclaimed or migrated.
5434 static int __init cmdline_parse_movablecore(char *p)
5436 return cmdline_parse_core(p, &required_movablecore);
5439 early_param("kernelcore", cmdline_parse_kernelcore);
5440 early_param("movablecore", cmdline_parse_movablecore);
5442 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5444 void adjust_managed_page_count(struct page *page, long count)
5446 spin_lock(&managed_page_count_lock);
5447 page_zone(page)->managed_pages += count;
5448 totalram_pages += count;
5449 #ifdef CONFIG_HIGHMEM
5450 if (PageHighMem(page))
5451 totalhigh_pages += count;
5453 spin_unlock(&managed_page_count_lock);
5455 EXPORT_SYMBOL(adjust_managed_page_count);
5457 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5460 unsigned long pages = 0;
5462 start = (void *)PAGE_ALIGN((unsigned long)start);
5463 end = (void *)((unsigned long)end & PAGE_MASK);
5464 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5465 if ((unsigned int)poison <= 0xFF)
5466 memset(pos, poison, PAGE_SIZE);
5467 free_reserved_page(virt_to_page(pos));
5471 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5472 s, pages << (PAGE_SHIFT - 10), start, end);
5476 EXPORT_SYMBOL(free_reserved_area);
5478 #ifdef CONFIG_HIGHMEM
5479 void free_highmem_page(struct page *page)
5481 __free_reserved_page(page);
5483 page_zone(page)->managed_pages++;
5489 void __init mem_init_print_info(const char *str)
5491 unsigned long physpages, codesize, datasize, rosize, bss_size;
5492 unsigned long init_code_size, init_data_size;
5494 physpages = get_num_physpages();
5495 codesize = _etext - _stext;
5496 datasize = _edata - _sdata;
5497 rosize = __end_rodata - __start_rodata;
5498 bss_size = __bss_stop - __bss_start;
5499 init_data_size = __init_end - __init_begin;
5500 init_code_size = _einittext - _sinittext;
5503 * Detect special cases and adjust section sizes accordingly:
5504 * 1) .init.* may be embedded into .data sections
5505 * 2) .init.text.* may be out of [__init_begin, __init_end],
5506 * please refer to arch/tile/kernel/vmlinux.lds.S.
5507 * 3) .rodata.* may be embedded into .text or .data sections.
5509 #define adj_init_size(start, end, size, pos, adj) \
5511 if (start <= pos && pos < end && size > adj) \
5515 adj_init_size(__init_begin, __init_end, init_data_size,
5516 _sinittext, init_code_size);
5517 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
5518 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
5519 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
5520 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
5522 #undef adj_init_size
5524 pr_info("Memory: %luK/%luK available "
5525 "(%luK kernel code, %luK rwdata, %luK rodata, "
5526 "%luK init, %luK bss, %luK reserved"
5527 #ifdef CONFIG_HIGHMEM
5531 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
5532 codesize >> 10, datasize >> 10, rosize >> 10,
5533 (init_data_size + init_code_size) >> 10, bss_size >> 10,
5534 (physpages - totalram_pages) << (PAGE_SHIFT-10),
5535 #ifdef CONFIG_HIGHMEM
5536 totalhigh_pages << (PAGE_SHIFT-10),
5538 str ? ", " : "", str ? str : "");
5542 * set_dma_reserve - set the specified number of pages reserved in the first zone
5543 * @new_dma_reserve: The number of pages to mark reserved
5545 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5546 * In the DMA zone, a significant percentage may be consumed by kernel image
5547 * and other unfreeable allocations which can skew the watermarks badly. This
5548 * function may optionally be used to account for unfreeable pages in the
5549 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5550 * smaller per-cpu batchsize.
5552 void __init set_dma_reserve(unsigned long new_dma_reserve)
5554 dma_reserve = new_dma_reserve;
5557 void __init free_area_init(unsigned long *zones_size)
5559 free_area_init_node(0, zones_size,
5560 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5563 static int page_alloc_cpu_notify(struct notifier_block *self,
5564 unsigned long action, void *hcpu)
5566 int cpu = (unsigned long)hcpu;
5568 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5569 lru_add_drain_cpu(cpu);
5573 * Spill the event counters of the dead processor
5574 * into the current processors event counters.
5575 * This artificially elevates the count of the current
5578 vm_events_fold_cpu(cpu);
5581 * Zero the differential counters of the dead processor
5582 * so that the vm statistics are consistent.
5584 * This is only okay since the processor is dead and cannot
5585 * race with what we are doing.
5587 cpu_vm_stats_fold(cpu);
5592 void __init page_alloc_init(void)
5594 hotcpu_notifier(page_alloc_cpu_notify, 0);
5598 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5599 * or min_free_kbytes changes.
5601 static void calculate_totalreserve_pages(void)
5603 struct pglist_data *pgdat;
5604 unsigned long reserve_pages = 0;
5605 enum zone_type i, j;
5607 for_each_online_pgdat(pgdat) {
5608 for (i = 0; i < MAX_NR_ZONES; i++) {
5609 struct zone *zone = pgdat->node_zones + i;
5612 /* Find valid and maximum lowmem_reserve in the zone */
5613 for (j = i; j < MAX_NR_ZONES; j++) {
5614 if (zone->lowmem_reserve[j] > max)
5615 max = zone->lowmem_reserve[j];
5618 /* we treat the high watermark as reserved pages. */
5619 max += high_wmark_pages(zone);
5621 if (max > zone->managed_pages)
5622 max = zone->managed_pages;
5623 reserve_pages += max;
5625 * Lowmem reserves are not available to
5626 * GFP_HIGHUSER page cache allocations and
5627 * kswapd tries to balance zones to their high
5628 * watermark. As a result, neither should be
5629 * regarded as dirtyable memory, to prevent a
5630 * situation where reclaim has to clean pages
5631 * in order to balance the zones.
5633 zone->dirty_balance_reserve = max;
5636 dirty_balance_reserve = reserve_pages;
5637 totalreserve_pages = reserve_pages;
5641 * setup_per_zone_lowmem_reserve - called whenever
5642 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5643 * has a correct pages reserved value, so an adequate number of
5644 * pages are left in the zone after a successful __alloc_pages().
5646 static void setup_per_zone_lowmem_reserve(void)
5648 struct pglist_data *pgdat;
5649 enum zone_type j, idx;
5651 for_each_online_pgdat(pgdat) {
5652 for (j = 0; j < MAX_NR_ZONES; j++) {
5653 struct zone *zone = pgdat->node_zones + j;
5654 unsigned long managed_pages = zone->managed_pages;
5656 zone->lowmem_reserve[j] = 0;
5660 struct zone *lower_zone;
5664 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5665 sysctl_lowmem_reserve_ratio[idx] = 1;
5667 lower_zone = pgdat->node_zones + idx;
5668 lower_zone->lowmem_reserve[j] = managed_pages /
5669 sysctl_lowmem_reserve_ratio[idx];
5670 managed_pages += lower_zone->managed_pages;
5675 /* update totalreserve_pages */
5676 calculate_totalreserve_pages();
5679 static void __setup_per_zone_wmarks(void)
5681 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5682 unsigned long lowmem_pages = 0;
5684 unsigned long flags;
5686 /* Calculate total number of !ZONE_HIGHMEM pages */
5687 for_each_zone(zone) {
5688 if (!is_highmem(zone))
5689 lowmem_pages += zone->managed_pages;
5692 for_each_zone(zone) {
5695 spin_lock_irqsave(&zone->lock, flags);
5696 tmp = (u64)pages_min * zone->managed_pages;
5697 do_div(tmp, lowmem_pages);
5698 if (is_highmem(zone)) {
5700 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5701 * need highmem pages, so cap pages_min to a small
5704 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5705 * deltas controls asynch page reclaim, and so should
5706 * not be capped for highmem.
5708 unsigned long min_pages;
5710 min_pages = zone->managed_pages / 1024;
5711 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
5712 zone->watermark[WMARK_MIN] = min_pages;
5715 * If it's a lowmem zone, reserve a number of pages
5716 * proportionate to the zone's size.
5718 zone->watermark[WMARK_MIN] = tmp;
5721 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5722 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5724 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
5725 high_wmark_pages(zone) - low_wmark_pages(zone) -
5726 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
5728 setup_zone_migrate_reserve(zone);
5729 spin_unlock_irqrestore(&zone->lock, flags);
5732 /* update totalreserve_pages */
5733 calculate_totalreserve_pages();
5737 * setup_per_zone_wmarks - called when min_free_kbytes changes
5738 * or when memory is hot-{added|removed}
5740 * Ensures that the watermark[min,low,high] values for each zone are set
5741 * correctly with respect to min_free_kbytes.
5743 void setup_per_zone_wmarks(void)
5745 mutex_lock(&zonelists_mutex);
5746 __setup_per_zone_wmarks();
5747 mutex_unlock(&zonelists_mutex);
5751 * The inactive anon list should be small enough that the VM never has to
5752 * do too much work, but large enough that each inactive page has a chance
5753 * to be referenced again before it is swapped out.
5755 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5756 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5757 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5758 * the anonymous pages are kept on the inactive list.
5761 * memory ratio inactive anon
5762 * -------------------------------------
5771 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5773 unsigned int gb, ratio;
5775 /* Zone size in gigabytes */
5776 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
5778 ratio = int_sqrt(10 * gb);
5782 zone->inactive_ratio = ratio;
5785 static void __meminit setup_per_zone_inactive_ratio(void)
5790 calculate_zone_inactive_ratio(zone);
5794 * Initialise min_free_kbytes.
5796 * For small machines we want it small (128k min). For large machines
5797 * we want it large (64MB max). But it is not linear, because network
5798 * bandwidth does not increase linearly with machine size. We use
5800 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5801 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5817 int __meminit init_per_zone_wmark_min(void)
5819 unsigned long lowmem_kbytes;
5820 int new_min_free_kbytes;
5822 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5823 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5825 if (new_min_free_kbytes > user_min_free_kbytes) {
5826 min_free_kbytes = new_min_free_kbytes;
5827 if (min_free_kbytes < 128)
5828 min_free_kbytes = 128;
5829 if (min_free_kbytes > 65536)
5830 min_free_kbytes = 65536;
5832 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5833 new_min_free_kbytes, user_min_free_kbytes);
5835 setup_per_zone_wmarks();
5836 refresh_zone_stat_thresholds();
5837 setup_per_zone_lowmem_reserve();
5838 setup_per_zone_inactive_ratio();
5841 module_init(init_per_zone_wmark_min)
5844 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5845 * that we can call two helper functions whenever min_free_kbytes
5848 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
5849 void __user *buffer, size_t *length, loff_t *ppos)
5853 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5858 user_min_free_kbytes = min_free_kbytes;
5859 setup_per_zone_wmarks();
5865 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
5866 void __user *buffer, size_t *length, loff_t *ppos)
5871 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5876 zone->min_unmapped_pages = (zone->managed_pages *
5877 sysctl_min_unmapped_ratio) / 100;
5881 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
5882 void __user *buffer, size_t *length, loff_t *ppos)
5887 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5892 zone->min_slab_pages = (zone->managed_pages *
5893 sysctl_min_slab_ratio) / 100;
5899 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5900 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5901 * whenever sysctl_lowmem_reserve_ratio changes.
5903 * The reserve ratio obviously has absolutely no relation with the
5904 * minimum watermarks. The lowmem reserve ratio can only make sense
5905 * if in function of the boot time zone sizes.
5907 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
5908 void __user *buffer, size_t *length, loff_t *ppos)
5910 proc_dointvec_minmax(table, write, buffer, length, ppos);
5911 setup_per_zone_lowmem_reserve();
5916 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5917 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5918 * pagelist can have before it gets flushed back to buddy allocator.
5920 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
5921 void __user *buffer, size_t *length, loff_t *ppos)
5924 int old_percpu_pagelist_fraction;
5927 mutex_lock(&pcp_batch_high_lock);
5928 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
5930 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5931 if (!write || ret < 0)
5934 /* Sanity checking to avoid pcp imbalance */
5935 if (percpu_pagelist_fraction &&
5936 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
5937 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
5943 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
5946 for_each_populated_zone(zone) {
5949 for_each_possible_cpu(cpu)
5950 pageset_set_high_and_batch(zone,
5951 per_cpu_ptr(zone->pageset, cpu));
5954 mutex_unlock(&pcp_batch_high_lock);
5958 int hashdist = HASHDIST_DEFAULT;
5961 static int __init set_hashdist(char *str)
5965 hashdist = simple_strtoul(str, &str, 0);
5968 __setup("hashdist=", set_hashdist);
5972 * allocate a large system hash table from bootmem
5973 * - it is assumed that the hash table must contain an exact power-of-2
5974 * quantity of entries
5975 * - limit is the number of hash buckets, not the total allocation size
5977 void *__init alloc_large_system_hash(const char *tablename,
5978 unsigned long bucketsize,
5979 unsigned long numentries,
5982 unsigned int *_hash_shift,
5983 unsigned int *_hash_mask,
5984 unsigned long low_limit,
5985 unsigned long high_limit)
5987 unsigned long long max = high_limit;
5988 unsigned long log2qty, size;
5991 /* allow the kernel cmdline to have a say */
5993 /* round applicable memory size up to nearest megabyte */
5994 numentries = nr_kernel_pages;
5996 /* It isn't necessary when PAGE_SIZE >= 1MB */
5997 if (PAGE_SHIFT < 20)
5998 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6000 /* limit to 1 bucket per 2^scale bytes of low memory */
6001 if (scale > PAGE_SHIFT)
6002 numentries >>= (scale - PAGE_SHIFT);
6004 numentries <<= (PAGE_SHIFT - scale);
6006 /* Make sure we've got at least a 0-order allocation.. */
6007 if (unlikely(flags & HASH_SMALL)) {
6008 /* Makes no sense without HASH_EARLY */
6009 WARN_ON(!(flags & HASH_EARLY));
6010 if (!(numentries >> *_hash_shift)) {
6011 numentries = 1UL << *_hash_shift;
6012 BUG_ON(!numentries);
6014 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6015 numentries = PAGE_SIZE / bucketsize;
6017 numentries = roundup_pow_of_two(numentries);
6019 /* limit allocation size to 1/16 total memory by default */
6021 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6022 do_div(max, bucketsize);
6024 max = min(max, 0x80000000ULL);
6026 if (numentries < low_limit)
6027 numentries = low_limit;
6028 if (numentries > max)
6031 log2qty = ilog2(numentries);
6034 size = bucketsize << log2qty;
6035 if (flags & HASH_EARLY)
6036 table = memblock_virt_alloc_nopanic(size, 0);
6038 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6041 * If bucketsize is not a power-of-two, we may free
6042 * some pages at the end of hash table which
6043 * alloc_pages_exact() automatically does
6045 if (get_order(size) < MAX_ORDER) {
6046 table = alloc_pages_exact(size, GFP_ATOMIC);
6047 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6050 } while (!table && size > PAGE_SIZE && --log2qty);
6053 panic("Failed to allocate %s hash table\n", tablename);
6055 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6058 ilog2(size) - PAGE_SHIFT,
6062 *_hash_shift = log2qty;
6064 *_hash_mask = (1 << log2qty) - 1;
6069 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6070 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6073 #ifdef CONFIG_SPARSEMEM
6074 return __pfn_to_section(pfn)->pageblock_flags;
6076 return zone->pageblock_flags;
6077 #endif /* CONFIG_SPARSEMEM */
6080 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6082 #ifdef CONFIG_SPARSEMEM
6083 pfn &= (PAGES_PER_SECTION-1);
6084 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6086 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6087 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6088 #endif /* CONFIG_SPARSEMEM */
6092 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6093 * @page: The page within the block of interest
6094 * @pfn: The target page frame number
6095 * @end_bitidx: The last bit of interest to retrieve
6096 * @mask: mask of bits that the caller is interested in
6098 * Return: pageblock_bits flags
6100 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6101 unsigned long end_bitidx,
6105 unsigned long *bitmap;
6106 unsigned long bitidx, word_bitidx;
6109 zone = page_zone(page);
6110 bitmap = get_pageblock_bitmap(zone, pfn);
6111 bitidx = pfn_to_bitidx(zone, pfn);
6112 word_bitidx = bitidx / BITS_PER_LONG;
6113 bitidx &= (BITS_PER_LONG-1);
6115 word = bitmap[word_bitidx];
6116 bitidx += end_bitidx;
6117 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6121 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6122 * @page: The page within the block of interest
6123 * @flags: The flags to set
6124 * @pfn: The target page frame number
6125 * @end_bitidx: The last bit of interest
6126 * @mask: mask of bits that the caller is interested in
6128 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6130 unsigned long end_bitidx,
6134 unsigned long *bitmap;
6135 unsigned long bitidx, word_bitidx;
6136 unsigned long old_word, word;
6138 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6140 zone = page_zone(page);
6141 bitmap = get_pageblock_bitmap(zone, pfn);
6142 bitidx = pfn_to_bitidx(zone, pfn);
6143 word_bitidx = bitidx / BITS_PER_LONG;
6144 bitidx &= (BITS_PER_LONG-1);
6146 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6148 bitidx += end_bitidx;
6149 mask <<= (BITS_PER_LONG - bitidx - 1);
6150 flags <<= (BITS_PER_LONG - bitidx - 1);
6152 word = ACCESS_ONCE(bitmap[word_bitidx]);
6154 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6155 if (word == old_word)
6162 * This function checks whether pageblock includes unmovable pages or not.
6163 * If @count is not zero, it is okay to include less @count unmovable pages
6165 * PageLRU check without isolation or lru_lock could race so that
6166 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6167 * expect this function should be exact.
6169 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6170 bool skip_hwpoisoned_pages)
6172 unsigned long pfn, iter, found;
6176 * For avoiding noise data, lru_add_drain_all() should be called
6177 * If ZONE_MOVABLE, the zone never contains unmovable pages
6179 if (zone_idx(zone) == ZONE_MOVABLE)
6181 mt = get_pageblock_migratetype(page);
6182 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6185 pfn = page_to_pfn(page);
6186 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6187 unsigned long check = pfn + iter;
6189 if (!pfn_valid_within(check))
6192 page = pfn_to_page(check);
6195 * Hugepages are not in LRU lists, but they're movable.
6196 * We need not scan over tail pages bacause we don't
6197 * handle each tail page individually in migration.
6199 if (PageHuge(page)) {
6200 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6205 * We can't use page_count without pin a page
6206 * because another CPU can free compound page.
6207 * This check already skips compound tails of THP
6208 * because their page->_count is zero at all time.
6210 if (!atomic_read(&page->_count)) {
6211 if (PageBuddy(page))
6212 iter += (1 << page_order(page)) - 1;
6217 * The HWPoisoned page may be not in buddy system, and
6218 * page_count() is not 0.
6220 if (skip_hwpoisoned_pages && PageHWPoison(page))
6226 * If there are RECLAIMABLE pages, we need to check it.
6227 * But now, memory offline itself doesn't call shrink_slab()
6228 * and it still to be fixed.
6231 * If the page is not RAM, page_count()should be 0.
6232 * we don't need more check. This is an _used_ not-movable page.
6234 * The problematic thing here is PG_reserved pages. PG_reserved
6235 * is set to both of a memory hole page and a _used_ kernel
6244 bool is_pageblock_removable_nolock(struct page *page)
6250 * We have to be careful here because we are iterating over memory
6251 * sections which are not zone aware so we might end up outside of
6252 * the zone but still within the section.
6253 * We have to take care about the node as well. If the node is offline
6254 * its NODE_DATA will be NULL - see page_zone.
6256 if (!node_online(page_to_nid(page)))
6259 zone = page_zone(page);
6260 pfn = page_to_pfn(page);
6261 if (!zone_spans_pfn(zone, pfn))
6264 return !has_unmovable_pages(zone, page, 0, true);
6269 static unsigned long pfn_max_align_down(unsigned long pfn)
6271 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6272 pageblock_nr_pages) - 1);
6275 static unsigned long pfn_max_align_up(unsigned long pfn)
6277 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6278 pageblock_nr_pages));
6281 /* [start, end) must belong to a single zone. */
6282 static int __alloc_contig_migrate_range(struct compact_control *cc,
6283 unsigned long start, unsigned long end)
6285 /* This function is based on compact_zone() from compaction.c. */
6286 unsigned long nr_reclaimed;
6287 unsigned long pfn = start;
6288 unsigned int tries = 0;
6293 while (pfn < end || !list_empty(&cc->migratepages)) {
6294 if (fatal_signal_pending(current)) {
6299 if (list_empty(&cc->migratepages)) {
6300 cc->nr_migratepages = 0;
6301 pfn = isolate_migratepages_range(cc, pfn, end);
6307 } else if (++tries == 5) {
6308 ret = ret < 0 ? ret : -EBUSY;
6312 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6314 cc->nr_migratepages -= nr_reclaimed;
6316 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6317 NULL, 0, cc->mode, MR_CMA);
6320 putback_movable_pages(&cc->migratepages);
6327 * alloc_contig_range() -- tries to allocate given range of pages
6328 * @start: start PFN to allocate
6329 * @end: one-past-the-last PFN to allocate
6330 * @migratetype: migratetype of the underlaying pageblocks (either
6331 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6332 * in range must have the same migratetype and it must
6333 * be either of the two.
6335 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6336 * aligned, however it's the caller's responsibility to guarantee that
6337 * we are the only thread that changes migrate type of pageblocks the
6340 * The PFN range must belong to a single zone.
6342 * Returns zero on success or negative error code. On success all
6343 * pages which PFN is in [start, end) are allocated for the caller and
6344 * need to be freed with free_contig_range().
6346 int alloc_contig_range(unsigned long start, unsigned long end,
6347 unsigned migratetype)
6349 unsigned long outer_start, outer_end;
6352 struct compact_control cc = {
6353 .nr_migratepages = 0,
6355 .zone = page_zone(pfn_to_page(start)),
6356 .mode = MIGRATE_SYNC,
6357 .ignore_skip_hint = true,
6359 INIT_LIST_HEAD(&cc.migratepages);
6362 * What we do here is we mark all pageblocks in range as
6363 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6364 * have different sizes, and due to the way page allocator
6365 * work, we align the range to biggest of the two pages so
6366 * that page allocator won't try to merge buddies from
6367 * different pageblocks and change MIGRATE_ISOLATE to some
6368 * other migration type.
6370 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6371 * migrate the pages from an unaligned range (ie. pages that
6372 * we are interested in). This will put all the pages in
6373 * range back to page allocator as MIGRATE_ISOLATE.
6375 * When this is done, we take the pages in range from page
6376 * allocator removing them from the buddy system. This way
6377 * page allocator will never consider using them.
6379 * This lets us mark the pageblocks back as
6380 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6381 * aligned range but not in the unaligned, original range are
6382 * put back to page allocator so that buddy can use them.
6385 ret = start_isolate_page_range(pfn_max_align_down(start),
6386 pfn_max_align_up(end), migratetype,
6391 ret = __alloc_contig_migrate_range(&cc, start, end);
6396 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6397 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6398 * more, all pages in [start, end) are free in page allocator.
6399 * What we are going to do is to allocate all pages from
6400 * [start, end) (that is remove them from page allocator).
6402 * The only problem is that pages at the beginning and at the
6403 * end of interesting range may be not aligned with pages that
6404 * page allocator holds, ie. they can be part of higher order
6405 * pages. Because of this, we reserve the bigger range and
6406 * once this is done free the pages we are not interested in.
6408 * We don't have to hold zone->lock here because the pages are
6409 * isolated thus they won't get removed from buddy.
6412 lru_add_drain_all();
6413 drain_all_pages(cc.zone);
6416 outer_start = start;
6417 while (!PageBuddy(pfn_to_page(outer_start))) {
6418 if (++order >= MAX_ORDER) {
6422 outer_start &= ~0UL << order;
6425 /* Make sure the range is really isolated. */
6426 if (test_pages_isolated(outer_start, end, false)) {
6427 pr_info("%s: [%lx, %lx) PFNs busy\n",
6428 __func__, outer_start, end);
6433 /* Grab isolated pages from freelists. */
6434 outer_end = isolate_freepages_range(&cc, outer_start, end);
6440 /* Free head and tail (if any) */
6441 if (start != outer_start)
6442 free_contig_range(outer_start, start - outer_start);
6443 if (end != outer_end)
6444 free_contig_range(end, outer_end - end);
6447 undo_isolate_page_range(pfn_max_align_down(start),
6448 pfn_max_align_up(end), migratetype);
6452 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6454 unsigned int count = 0;
6456 for (; nr_pages--; pfn++) {
6457 struct page *page = pfn_to_page(pfn);
6459 count += page_count(page) != 1;
6462 WARN(count != 0, "%d pages are still in use!\n", count);
6466 #ifdef CONFIG_MEMORY_HOTPLUG
6468 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6469 * page high values need to be recalulated.
6471 void __meminit zone_pcp_update(struct zone *zone)
6474 mutex_lock(&pcp_batch_high_lock);
6475 for_each_possible_cpu(cpu)
6476 pageset_set_high_and_batch(zone,
6477 per_cpu_ptr(zone->pageset, cpu));
6478 mutex_unlock(&pcp_batch_high_lock);
6482 void zone_pcp_reset(struct zone *zone)
6484 unsigned long flags;
6486 struct per_cpu_pageset *pset;
6488 /* avoid races with drain_pages() */
6489 local_irq_save(flags);
6490 if (zone->pageset != &boot_pageset) {
6491 for_each_online_cpu(cpu) {
6492 pset = per_cpu_ptr(zone->pageset, cpu);
6493 drain_zonestat(zone, pset);
6495 free_percpu(zone->pageset);
6496 zone->pageset = &boot_pageset;
6498 local_irq_restore(flags);
6501 #ifdef CONFIG_MEMORY_HOTREMOVE
6503 * All pages in the range must be isolated before calling this.
6506 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6510 unsigned int order, i;
6512 unsigned long flags;
6513 /* find the first valid pfn */
6514 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6519 zone = page_zone(pfn_to_page(pfn));
6520 spin_lock_irqsave(&zone->lock, flags);
6522 while (pfn < end_pfn) {
6523 if (!pfn_valid(pfn)) {
6527 page = pfn_to_page(pfn);
6529 * The HWPoisoned page may be not in buddy system, and
6530 * page_count() is not 0.
6532 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
6534 SetPageReserved(page);
6538 BUG_ON(page_count(page));
6539 BUG_ON(!PageBuddy(page));
6540 order = page_order(page);
6541 #ifdef CONFIG_DEBUG_VM
6542 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6543 pfn, 1 << order, end_pfn);
6545 list_del(&page->lru);
6546 rmv_page_order(page);
6547 zone->free_area[order].nr_free--;
6548 for (i = 0; i < (1 << order); i++)
6549 SetPageReserved((page+i));
6550 pfn += (1 << order);
6552 spin_unlock_irqrestore(&zone->lock, flags);
6556 #ifdef CONFIG_MEMORY_FAILURE
6557 bool is_free_buddy_page(struct page *page)
6559 struct zone *zone = page_zone(page);
6560 unsigned long pfn = page_to_pfn(page);
6561 unsigned long flags;
6564 spin_lock_irqsave(&zone->lock, flags);
6565 for (order = 0; order < MAX_ORDER; order++) {
6566 struct page *page_head = page - (pfn & ((1 << order) - 1));
6568 if (PageBuddy(page_head) && page_order(page_head) >= order)
6571 spin_unlock_irqrestore(&zone->lock, flags);
6573 return order < MAX_ORDER;