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 trace_mm_page_free(page, order);
745 kmemcheck_free_shadow(page, order);
748 page->mapping = NULL;
749 for (i = 0; i < (1 << order); i++)
750 bad += free_pages_check(page + i);
754 if (!PageHighMem(page)) {
755 debug_check_no_locks_freed(page_address(page),
757 debug_check_no_obj_freed(page_address(page),
760 arch_free_page(page, order);
761 kernel_map_pages(page, 1 << order, 0);
766 static void __free_pages_ok(struct page *page, unsigned int order)
770 unsigned long pfn = page_to_pfn(page);
772 if (!free_pages_prepare(page, order))
775 migratetype = get_pfnblock_migratetype(page, pfn);
776 local_irq_save(flags);
777 __count_vm_events(PGFREE, 1 << order);
778 set_freepage_migratetype(page, migratetype);
779 free_one_page(page_zone(page), page, pfn, order, migratetype);
780 local_irq_restore(flags);
783 void __init __free_pages_bootmem(struct page *page, unsigned int order)
785 unsigned int nr_pages = 1 << order;
786 struct page *p = page;
790 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
792 __ClearPageReserved(p);
793 set_page_count(p, 0);
795 __ClearPageReserved(p);
796 set_page_count(p, 0);
798 page_zone(page)->managed_pages += nr_pages;
799 set_page_refcounted(page);
800 __free_pages(page, order);
804 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
805 void __init init_cma_reserved_pageblock(struct page *page)
807 unsigned i = pageblock_nr_pages;
808 struct page *p = page;
811 __ClearPageReserved(p);
812 set_page_count(p, 0);
815 set_pageblock_migratetype(page, MIGRATE_CMA);
817 if (pageblock_order >= MAX_ORDER) {
818 i = pageblock_nr_pages;
821 set_page_refcounted(p);
822 __free_pages(p, MAX_ORDER - 1);
823 p += MAX_ORDER_NR_PAGES;
824 } while (i -= MAX_ORDER_NR_PAGES);
826 set_page_refcounted(page);
827 __free_pages(page, pageblock_order);
830 adjust_managed_page_count(page, pageblock_nr_pages);
835 * The order of subdivision here is critical for the IO subsystem.
836 * Please do not alter this order without good reasons and regression
837 * testing. Specifically, as large blocks of memory are subdivided,
838 * the order in which smaller blocks are delivered depends on the order
839 * they're subdivided in this function. This is the primary factor
840 * influencing the order in which pages are delivered to the IO
841 * subsystem according to empirical testing, and this is also justified
842 * by considering the behavior of a buddy system containing a single
843 * large block of memory acted on by a series of small allocations.
844 * This behavior is a critical factor in sglist merging's success.
848 static inline void expand(struct zone *zone, struct page *page,
849 int low, int high, struct free_area *area,
852 unsigned long size = 1 << high;
858 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
860 #ifdef CONFIG_DEBUG_PAGEALLOC
861 if (high < debug_guardpage_minorder()) {
863 * Mark as guard pages (or page), that will allow to
864 * merge back to allocator when buddy will be freed.
865 * Corresponding page table entries will not be touched,
866 * pages will stay not present in virtual address space
868 INIT_LIST_HEAD(&page[size].lru);
869 set_page_guard_flag(&page[size]);
870 set_page_private(&page[size], high);
871 /* Guard pages are not available for any usage */
872 __mod_zone_freepage_state(zone, -(1 << high),
877 list_add(&page[size].lru, &area->free_list[migratetype]);
879 set_page_order(&page[size], high);
884 * This page is about to be returned from the page allocator
886 static inline int check_new_page(struct page *page)
888 const char *bad_reason = NULL;
889 unsigned long bad_flags = 0;
891 if (unlikely(page_mapcount(page)))
892 bad_reason = "nonzero mapcount";
893 if (unlikely(page->mapping != NULL))
894 bad_reason = "non-NULL mapping";
895 if (unlikely(atomic_read(&page->_count) != 0))
896 bad_reason = "nonzero _count";
897 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
898 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
899 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
901 if (unlikely(mem_cgroup_bad_page_check(page)))
902 bad_reason = "cgroup check failed";
903 if (unlikely(bad_reason)) {
904 bad_page(page, bad_reason, bad_flags);
910 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags)
914 for (i = 0; i < (1 << order); i++) {
915 struct page *p = page + i;
916 if (unlikely(check_new_page(p)))
920 set_page_private(page, 0);
921 set_page_refcounted(page);
923 arch_alloc_page(page, order);
924 kernel_map_pages(page, 1 << order, 1);
926 if (gfp_flags & __GFP_ZERO)
927 prep_zero_page(page, order, gfp_flags);
929 if (order && (gfp_flags & __GFP_COMP))
930 prep_compound_page(page, order);
936 * Go through the free lists for the given migratetype and remove
937 * the smallest available page from the freelists
940 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
943 unsigned int current_order;
944 struct free_area *area;
947 /* Find a page of the appropriate size in the preferred list */
948 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
949 area = &(zone->free_area[current_order]);
950 if (list_empty(&area->free_list[migratetype]))
953 page = list_entry(area->free_list[migratetype].next,
955 list_del(&page->lru);
956 rmv_page_order(page);
958 expand(zone, page, order, current_order, area, migratetype);
959 set_freepage_migratetype(page, migratetype);
968 * This array describes the order lists are fallen back to when
969 * the free lists for the desirable migrate type are depleted
971 static int fallbacks[MIGRATE_TYPES][4] = {
972 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
973 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
975 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
976 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
978 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
980 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
981 #ifdef CONFIG_MEMORY_ISOLATION
982 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
987 * Move the free pages in a range to the free lists of the requested type.
988 * Note that start_page and end_pages are not aligned on a pageblock
989 * boundary. If alignment is required, use move_freepages_block()
991 int move_freepages(struct zone *zone,
992 struct page *start_page, struct page *end_page,
999 #ifndef CONFIG_HOLES_IN_ZONE
1001 * page_zone is not safe to call in this context when
1002 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1003 * anyway as we check zone boundaries in move_freepages_block().
1004 * Remove at a later date when no bug reports exist related to
1005 * grouping pages by mobility
1007 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1010 for (page = start_page; page <= end_page;) {
1011 /* Make sure we are not inadvertently changing nodes */
1012 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1014 if (!pfn_valid_within(page_to_pfn(page))) {
1019 if (!PageBuddy(page)) {
1024 order = page_order(page);
1025 list_move(&page->lru,
1026 &zone->free_area[order].free_list[migratetype]);
1027 set_freepage_migratetype(page, migratetype);
1029 pages_moved += 1 << order;
1035 int move_freepages_block(struct zone *zone, struct page *page,
1038 unsigned long start_pfn, end_pfn;
1039 struct page *start_page, *end_page;
1041 start_pfn = page_to_pfn(page);
1042 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1043 start_page = pfn_to_page(start_pfn);
1044 end_page = start_page + pageblock_nr_pages - 1;
1045 end_pfn = start_pfn + pageblock_nr_pages - 1;
1047 /* Do not cross zone boundaries */
1048 if (!zone_spans_pfn(zone, start_pfn))
1050 if (!zone_spans_pfn(zone, end_pfn))
1053 return move_freepages(zone, start_page, end_page, migratetype);
1056 static void change_pageblock_range(struct page *pageblock_page,
1057 int start_order, int migratetype)
1059 int nr_pageblocks = 1 << (start_order - pageblock_order);
1061 while (nr_pageblocks--) {
1062 set_pageblock_migratetype(pageblock_page, migratetype);
1063 pageblock_page += pageblock_nr_pages;
1068 * If breaking a large block of pages, move all free pages to the preferred
1069 * allocation list. If falling back for a reclaimable kernel allocation, be
1070 * more aggressive about taking ownership of free pages.
1072 * On the other hand, never change migration type of MIGRATE_CMA pageblocks
1073 * nor move CMA pages to different free lists. We don't want unmovable pages
1074 * to be allocated from MIGRATE_CMA areas.
1076 * Returns the new migratetype of the pageblock (or the same old migratetype
1077 * if it was unchanged).
1079 static int try_to_steal_freepages(struct zone *zone, struct page *page,
1080 int start_type, int fallback_type)
1082 int current_order = page_order(page);
1085 * When borrowing from MIGRATE_CMA, we need to release the excess
1086 * buddy pages to CMA itself. We also ensure the freepage_migratetype
1087 * is set to CMA so it is returned to the correct freelist in case
1088 * the page ends up being not actually allocated from the pcp lists.
1090 if (is_migrate_cma(fallback_type))
1091 return fallback_type;
1093 /* Take ownership for orders >= pageblock_order */
1094 if (current_order >= pageblock_order) {
1095 change_pageblock_range(page, current_order, start_type);
1099 if (current_order >= pageblock_order / 2 ||
1100 start_type == MIGRATE_RECLAIMABLE ||
1101 page_group_by_mobility_disabled) {
1104 pages = move_freepages_block(zone, page, start_type);
1106 /* Claim the whole block if over half of it is free */
1107 if (pages >= (1 << (pageblock_order-1)) ||
1108 page_group_by_mobility_disabled) {
1110 set_pageblock_migratetype(page, start_type);
1116 return fallback_type;
1119 /* Remove an element from the buddy allocator from the fallback list */
1120 static inline struct page *
1121 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1123 struct free_area *area;
1124 unsigned int current_order;
1126 int migratetype, new_type, i;
1128 /* Find the largest possible block of pages in the other list */
1129 for (current_order = MAX_ORDER-1;
1130 current_order >= order && current_order <= MAX_ORDER-1;
1133 migratetype = fallbacks[start_migratetype][i];
1135 /* MIGRATE_RESERVE handled later if necessary */
1136 if (migratetype == MIGRATE_RESERVE)
1139 area = &(zone->free_area[current_order]);
1140 if (list_empty(&area->free_list[migratetype]))
1143 page = list_entry(area->free_list[migratetype].next,
1147 new_type = try_to_steal_freepages(zone, page,
1151 /* Remove the page from the freelists */
1152 list_del(&page->lru);
1153 rmv_page_order(page);
1155 expand(zone, page, order, current_order, area,
1157 /* The freepage_migratetype may differ from pageblock's
1158 * migratetype depending on the decisions in
1159 * try_to_steal_freepages. This is OK as long as it does
1160 * not differ for MIGRATE_CMA type.
1162 set_freepage_migratetype(page, new_type);
1164 trace_mm_page_alloc_extfrag(page, order, current_order,
1165 start_migratetype, migratetype, new_type);
1175 * Do the hard work of removing an element from the buddy allocator.
1176 * Call me with the zone->lock already held.
1178 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1184 page = __rmqueue_smallest(zone, order, migratetype);
1186 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1187 page = __rmqueue_fallback(zone, order, migratetype);
1190 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1191 * is used because __rmqueue_smallest is an inline function
1192 * and we want just one call site
1195 migratetype = MIGRATE_RESERVE;
1200 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1205 * Obtain a specified number of elements from the buddy allocator, all under
1206 * a single hold of the lock, for efficiency. Add them to the supplied list.
1207 * Returns the number of new pages which were placed at *list.
1209 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1210 unsigned long count, struct list_head *list,
1211 int migratetype, bool cold)
1215 spin_lock(&zone->lock);
1216 for (i = 0; i < count; ++i) {
1217 struct page *page = __rmqueue(zone, order, migratetype);
1218 if (unlikely(page == NULL))
1222 * Split buddy pages returned by expand() are received here
1223 * in physical page order. The page is added to the callers and
1224 * list and the list head then moves forward. From the callers
1225 * perspective, the linked list is ordered by page number in
1226 * some conditions. This is useful for IO devices that can
1227 * merge IO requests if the physical pages are ordered
1231 list_add(&page->lru, list);
1233 list_add_tail(&page->lru, list);
1235 if (is_migrate_cma(get_freepage_migratetype(page)))
1236 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1239 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1240 spin_unlock(&zone->lock);
1246 * Called from the vmstat counter updater to drain pagesets of this
1247 * currently executing processor on remote nodes after they have
1250 * Note that this function must be called with the thread pinned to
1251 * a single processor.
1253 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1255 unsigned long flags;
1256 int to_drain, batch;
1258 local_irq_save(flags);
1259 batch = ACCESS_ONCE(pcp->batch);
1260 to_drain = min(pcp->count, batch);
1262 free_pcppages_bulk(zone, to_drain, pcp);
1263 pcp->count -= to_drain;
1265 local_irq_restore(flags);
1270 * Drain pages of the indicated processor.
1272 * The processor must either be the current processor and the
1273 * thread pinned to the current processor or a processor that
1276 static void drain_pages(unsigned int cpu)
1278 unsigned long flags;
1281 for_each_populated_zone(zone) {
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);
1298 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1300 void drain_local_pages(void *arg)
1302 drain_pages(smp_processor_id());
1306 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1308 * Note that this code is protected against sending an IPI to an offline
1309 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1310 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1311 * nothing keeps CPUs from showing up after we populated the cpumask and
1312 * before the call to on_each_cpu_mask().
1314 void drain_all_pages(void)
1317 struct per_cpu_pageset *pcp;
1321 * Allocate in the BSS so we wont require allocation in
1322 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1324 static cpumask_t cpus_with_pcps;
1327 * We don't care about racing with CPU hotplug event
1328 * as offline notification will cause the notified
1329 * cpu to drain that CPU pcps and on_each_cpu_mask
1330 * disables preemption as part of its processing
1332 for_each_online_cpu(cpu) {
1333 bool has_pcps = false;
1334 for_each_populated_zone(zone) {
1335 pcp = per_cpu_ptr(zone->pageset, cpu);
1336 if (pcp->pcp.count) {
1342 cpumask_set_cpu(cpu, &cpus_with_pcps);
1344 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1346 on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
1349 #ifdef CONFIG_HIBERNATION
1351 void mark_free_pages(struct zone *zone)
1353 unsigned long pfn, max_zone_pfn;
1354 unsigned long flags;
1355 unsigned int order, t;
1356 struct list_head *curr;
1358 if (zone_is_empty(zone))
1361 spin_lock_irqsave(&zone->lock, flags);
1363 max_zone_pfn = zone_end_pfn(zone);
1364 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1365 if (pfn_valid(pfn)) {
1366 struct page *page = pfn_to_page(pfn);
1368 if (!swsusp_page_is_forbidden(page))
1369 swsusp_unset_page_free(page);
1372 for_each_migratetype_order(order, t) {
1373 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1376 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1377 for (i = 0; i < (1UL << order); i++)
1378 swsusp_set_page_free(pfn_to_page(pfn + i));
1381 spin_unlock_irqrestore(&zone->lock, flags);
1383 #endif /* CONFIG_PM */
1386 * Free a 0-order page
1387 * cold == true ? free a cold page : free a hot page
1389 void free_hot_cold_page(struct page *page, bool cold)
1391 struct zone *zone = page_zone(page);
1392 struct per_cpu_pages *pcp;
1393 unsigned long flags;
1394 unsigned long pfn = page_to_pfn(page);
1397 if (!free_pages_prepare(page, 0))
1400 migratetype = get_pfnblock_migratetype(page, pfn);
1401 set_freepage_migratetype(page, migratetype);
1402 local_irq_save(flags);
1403 __count_vm_event(PGFREE);
1406 * We only track unmovable, reclaimable and movable on pcp lists.
1407 * Free ISOLATE pages back to the allocator because they are being
1408 * offlined but treat RESERVE as movable pages so we can get those
1409 * areas back if necessary. Otherwise, we may have to free
1410 * excessively into the page allocator
1412 if (migratetype >= MIGRATE_PCPTYPES) {
1413 if (unlikely(is_migrate_isolate(migratetype))) {
1414 free_one_page(zone, page, pfn, 0, migratetype);
1417 migratetype = MIGRATE_MOVABLE;
1420 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1422 list_add(&page->lru, &pcp->lists[migratetype]);
1424 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1426 if (pcp->count >= pcp->high) {
1427 unsigned long batch = ACCESS_ONCE(pcp->batch);
1428 free_pcppages_bulk(zone, batch, pcp);
1429 pcp->count -= batch;
1433 local_irq_restore(flags);
1437 * Free a list of 0-order pages
1439 void free_hot_cold_page_list(struct list_head *list, bool cold)
1441 struct page *page, *next;
1443 list_for_each_entry_safe(page, next, list, lru) {
1444 trace_mm_page_free_batched(page, cold);
1445 free_hot_cold_page(page, cold);
1450 * split_page takes a non-compound higher-order page, and splits it into
1451 * n (1<<order) sub-pages: page[0..n]
1452 * Each sub-page must be freed individually.
1454 * Note: this is probably too low level an operation for use in drivers.
1455 * Please consult with lkml before using this in your driver.
1457 void split_page(struct page *page, unsigned int order)
1461 VM_BUG_ON_PAGE(PageCompound(page), page);
1462 VM_BUG_ON_PAGE(!page_count(page), page);
1464 #ifdef CONFIG_KMEMCHECK
1466 * Split shadow pages too, because free(page[0]) would
1467 * otherwise free the whole shadow.
1469 if (kmemcheck_page_is_tracked(page))
1470 split_page(virt_to_page(page[0].shadow), order);
1473 for (i = 1; i < (1 << order); i++)
1474 set_page_refcounted(page + i);
1476 EXPORT_SYMBOL_GPL(split_page);
1478 int __isolate_free_page(struct page *page, unsigned int order)
1480 unsigned long watermark;
1484 BUG_ON(!PageBuddy(page));
1486 zone = page_zone(page);
1487 mt = get_pageblock_migratetype(page);
1489 if (!is_migrate_isolate(mt)) {
1490 /* Obey watermarks as if the page was being allocated */
1491 watermark = low_wmark_pages(zone) + (1 << order);
1492 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1495 __mod_zone_freepage_state(zone, -(1UL << order), mt);
1498 /* Remove page from free list */
1499 list_del(&page->lru);
1500 zone->free_area[order].nr_free--;
1501 rmv_page_order(page);
1503 /* Set the pageblock if the isolated page is at least a pageblock */
1504 if (order >= pageblock_order - 1) {
1505 struct page *endpage = page + (1 << order) - 1;
1506 for (; page < endpage; page += pageblock_nr_pages) {
1507 int mt = get_pageblock_migratetype(page);
1508 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
1509 set_pageblock_migratetype(page,
1514 return 1UL << order;
1518 * Similar to split_page except the page is already free. As this is only
1519 * being used for migration, the migratetype of the block also changes.
1520 * As this is called with interrupts disabled, the caller is responsible
1521 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1524 * Note: this is probably too low level an operation for use in drivers.
1525 * Please consult with lkml before using this in your driver.
1527 int split_free_page(struct page *page)
1532 order = page_order(page);
1534 nr_pages = __isolate_free_page(page, order);
1538 /* Split into individual pages */
1539 set_page_refcounted(page);
1540 split_page(page, order);
1545 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1546 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1550 struct page *buffered_rmqueue(struct zone *preferred_zone,
1551 struct zone *zone, unsigned int order,
1552 gfp_t gfp_flags, int migratetype)
1554 unsigned long flags;
1556 bool cold = ((gfp_flags & __GFP_COLD) != 0);
1559 if (likely(order == 0)) {
1560 struct per_cpu_pages *pcp;
1561 struct list_head *list;
1563 local_irq_save(flags);
1564 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1565 list = &pcp->lists[migratetype];
1566 if (list_empty(list)) {
1567 pcp->count += rmqueue_bulk(zone, 0,
1570 if (unlikely(list_empty(list)))
1575 page = list_entry(list->prev, struct page, lru);
1577 page = list_entry(list->next, struct page, lru);
1579 list_del(&page->lru);
1582 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1584 * __GFP_NOFAIL is not to be used in new code.
1586 * All __GFP_NOFAIL callers should be fixed so that they
1587 * properly detect and handle allocation failures.
1589 * We most definitely don't want callers attempting to
1590 * allocate greater than order-1 page units with
1593 WARN_ON_ONCE(order > 1);
1595 spin_lock_irqsave(&zone->lock, flags);
1596 page = __rmqueue(zone, order, migratetype);
1597 spin_unlock(&zone->lock);
1600 __mod_zone_freepage_state(zone, -(1 << order),
1601 get_freepage_migratetype(page));
1604 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
1605 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
1606 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
1607 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
1609 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1610 zone_statistics(preferred_zone, zone, gfp_flags);
1611 local_irq_restore(flags);
1613 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1614 if (prep_new_page(page, order, gfp_flags))
1619 local_irq_restore(flags);
1623 #ifdef CONFIG_FAIL_PAGE_ALLOC
1626 struct fault_attr attr;
1628 u32 ignore_gfp_highmem;
1629 u32 ignore_gfp_wait;
1631 } fail_page_alloc = {
1632 .attr = FAULT_ATTR_INITIALIZER,
1633 .ignore_gfp_wait = 1,
1634 .ignore_gfp_highmem = 1,
1638 static int __init setup_fail_page_alloc(char *str)
1640 return setup_fault_attr(&fail_page_alloc.attr, str);
1642 __setup("fail_page_alloc=", setup_fail_page_alloc);
1644 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1646 if (order < fail_page_alloc.min_order)
1648 if (gfp_mask & __GFP_NOFAIL)
1650 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1652 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1655 return should_fail(&fail_page_alloc.attr, 1 << order);
1658 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1660 static int __init fail_page_alloc_debugfs(void)
1662 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1665 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1666 &fail_page_alloc.attr);
1668 return PTR_ERR(dir);
1670 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1671 &fail_page_alloc.ignore_gfp_wait))
1673 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1674 &fail_page_alloc.ignore_gfp_highmem))
1676 if (!debugfs_create_u32("min-order", mode, dir,
1677 &fail_page_alloc.min_order))
1682 debugfs_remove_recursive(dir);
1687 late_initcall(fail_page_alloc_debugfs);
1689 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1691 #else /* CONFIG_FAIL_PAGE_ALLOC */
1693 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1698 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1701 * Return true if free pages are above 'mark'. This takes into account the order
1702 * of the allocation.
1704 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
1705 unsigned long mark, int classzone_idx, int alloc_flags,
1708 /* free_pages my go negative - that's OK */
1713 free_pages -= (1 << order) - 1;
1714 if (alloc_flags & ALLOC_HIGH)
1716 if (alloc_flags & ALLOC_HARDER)
1719 /* If allocation can't use CMA areas don't use free CMA pages */
1720 if (!(alloc_flags & ALLOC_CMA))
1721 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
1724 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
1726 for (o = 0; o < order; o++) {
1727 /* At the next order, this order's pages become unavailable */
1728 free_pages -= z->free_area[o].nr_free << o;
1730 /* Require fewer higher order pages to be free */
1733 if (free_pages <= min)
1739 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1740 int classzone_idx, int alloc_flags)
1742 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1743 zone_page_state(z, NR_FREE_PAGES));
1746 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1747 unsigned long mark, int classzone_idx, int alloc_flags)
1749 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1751 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1752 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1754 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1760 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1761 * skip over zones that are not allowed by the cpuset, or that have
1762 * been recently (in last second) found to be nearly full. See further
1763 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1764 * that have to skip over a lot of full or unallowed zones.
1766 * If the zonelist cache is present in the passed zonelist, then
1767 * returns a pointer to the allowed node mask (either the current
1768 * tasks mems_allowed, or node_states[N_MEMORY].)
1770 * If the zonelist cache is not available for this zonelist, does
1771 * nothing and returns NULL.
1773 * If the fullzones BITMAP in the zonelist cache is stale (more than
1774 * a second since last zap'd) then we zap it out (clear its bits.)
1776 * We hold off even calling zlc_setup, until after we've checked the
1777 * first zone in the zonelist, on the theory that most allocations will
1778 * be satisfied from that first zone, so best to examine that zone as
1779 * quickly as we can.
1781 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1783 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1784 nodemask_t *allowednodes; /* zonelist_cache approximation */
1786 zlc = zonelist->zlcache_ptr;
1790 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1791 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1792 zlc->last_full_zap = jiffies;
1795 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1796 &cpuset_current_mems_allowed :
1797 &node_states[N_MEMORY];
1798 return allowednodes;
1802 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1803 * if it is worth looking at further for free memory:
1804 * 1) Check that the zone isn't thought to be full (doesn't have its
1805 * bit set in the zonelist_cache fullzones BITMAP).
1806 * 2) Check that the zones node (obtained from the zonelist_cache
1807 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1808 * Return true (non-zero) if zone is worth looking at further, or
1809 * else return false (zero) if it is not.
1811 * This check -ignores- the distinction between various watermarks,
1812 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1813 * found to be full for any variation of these watermarks, it will
1814 * be considered full for up to one second by all requests, unless
1815 * we are so low on memory on all allowed nodes that we are forced
1816 * into the second scan of the zonelist.
1818 * In the second scan we ignore this zonelist cache and exactly
1819 * apply the watermarks to all zones, even it is slower to do so.
1820 * We are low on memory in the second scan, and should leave no stone
1821 * unturned looking for a free page.
1823 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1824 nodemask_t *allowednodes)
1826 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1827 int i; /* index of *z in zonelist zones */
1828 int n; /* node that zone *z is on */
1830 zlc = zonelist->zlcache_ptr;
1834 i = z - zonelist->_zonerefs;
1837 /* This zone is worth trying if it is allowed but not full */
1838 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1842 * Given 'z' scanning a zonelist, set the corresponding bit in
1843 * zlc->fullzones, so that subsequent attempts to allocate a page
1844 * from that zone don't waste time re-examining it.
1846 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1848 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1849 int i; /* index of *z in zonelist zones */
1851 zlc = zonelist->zlcache_ptr;
1855 i = z - zonelist->_zonerefs;
1857 set_bit(i, zlc->fullzones);
1861 * clear all zones full, called after direct reclaim makes progress so that
1862 * a zone that was recently full is not skipped over for up to a second
1864 static void zlc_clear_zones_full(struct zonelist *zonelist)
1866 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1868 zlc = zonelist->zlcache_ptr;
1872 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1875 static bool zone_local(struct zone *local_zone, struct zone *zone)
1877 return local_zone->node == zone->node;
1880 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1882 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
1886 #else /* CONFIG_NUMA */
1888 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1893 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1894 nodemask_t *allowednodes)
1899 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1903 static void zlc_clear_zones_full(struct zonelist *zonelist)
1907 static bool zone_local(struct zone *local_zone, struct zone *zone)
1912 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1917 #endif /* CONFIG_NUMA */
1919 static void reset_alloc_batches(struct zone *preferred_zone)
1921 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
1924 mod_zone_page_state(zone, NR_ALLOC_BATCH,
1925 high_wmark_pages(zone) - low_wmark_pages(zone) -
1926 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
1927 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
1928 } while (zone++ != preferred_zone);
1932 * get_page_from_freelist goes through the zonelist trying to allocate
1935 static struct page *
1936 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1937 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1938 struct zone *preferred_zone, int classzone_idx, int migratetype)
1941 struct page *page = NULL;
1943 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1944 int zlc_active = 0; /* set if using zonelist_cache */
1945 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1946 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
1947 (gfp_mask & __GFP_WRITE);
1948 int nr_fair_skipped = 0;
1949 bool zonelist_rescan;
1952 zonelist_rescan = false;
1955 * Scan zonelist, looking for a zone with enough free.
1956 * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
1958 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1959 high_zoneidx, nodemask) {
1962 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1963 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1965 if (cpusets_enabled() &&
1966 (alloc_flags & ALLOC_CPUSET) &&
1967 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1970 * Distribute pages in proportion to the individual
1971 * zone size to ensure fair page aging. The zone a
1972 * page was allocated in should have no effect on the
1973 * time the page has in memory before being reclaimed.
1975 if (alloc_flags & ALLOC_FAIR) {
1976 if (!zone_local(preferred_zone, zone))
1978 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
1984 * When allocating a page cache page for writing, we
1985 * want to get it from a zone that is within its dirty
1986 * limit, such that no single zone holds more than its
1987 * proportional share of globally allowed dirty pages.
1988 * The dirty limits take into account the zone's
1989 * lowmem reserves and high watermark so that kswapd
1990 * should be able to balance it without having to
1991 * write pages from its LRU list.
1993 * This may look like it could increase pressure on
1994 * lower zones by failing allocations in higher zones
1995 * before they are full. But the pages that do spill
1996 * over are limited as the lower zones are protected
1997 * by this very same mechanism. It should not become
1998 * a practical burden to them.
2000 * XXX: For now, allow allocations to potentially
2001 * exceed the per-zone dirty limit in the slowpath
2002 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2003 * which is important when on a NUMA setup the allowed
2004 * zones are together not big enough to reach the
2005 * global limit. The proper fix for these situations
2006 * will require awareness of zones in the
2007 * dirty-throttling and the flusher threads.
2009 if (consider_zone_dirty && !zone_dirty_ok(zone))
2012 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2013 if (!zone_watermark_ok(zone, order, mark,
2014 classzone_idx, alloc_flags)) {
2017 /* Checked here to keep the fast path fast */
2018 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2019 if (alloc_flags & ALLOC_NO_WATERMARKS)
2022 if (IS_ENABLED(CONFIG_NUMA) &&
2023 !did_zlc_setup && nr_online_nodes > 1) {
2025 * we do zlc_setup if there are multiple nodes
2026 * and before considering the first zone allowed
2029 allowednodes = zlc_setup(zonelist, alloc_flags);
2034 if (zone_reclaim_mode == 0 ||
2035 !zone_allows_reclaim(preferred_zone, zone))
2036 goto this_zone_full;
2039 * As we may have just activated ZLC, check if the first
2040 * eligible zone has failed zone_reclaim recently.
2042 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2043 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2046 ret = zone_reclaim(zone, gfp_mask, order);
2048 case ZONE_RECLAIM_NOSCAN:
2051 case ZONE_RECLAIM_FULL:
2052 /* scanned but unreclaimable */
2055 /* did we reclaim enough */
2056 if (zone_watermark_ok(zone, order, mark,
2057 classzone_idx, alloc_flags))
2061 * Failed to reclaim enough to meet watermark.
2062 * Only mark the zone full if checking the min
2063 * watermark or if we failed to reclaim just
2064 * 1<<order pages or else the page allocator
2065 * fastpath will prematurely mark zones full
2066 * when the watermark is between the low and
2069 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2070 ret == ZONE_RECLAIM_SOME)
2071 goto this_zone_full;
2078 page = buffered_rmqueue(preferred_zone, zone, order,
2079 gfp_mask, migratetype);
2083 if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
2084 zlc_mark_zone_full(zonelist, z);
2089 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
2090 * necessary to allocate the page. The expectation is
2091 * that the caller is taking steps that will free more
2092 * memory. The caller should avoid the page being used
2093 * for !PFMEMALLOC purposes.
2095 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
2100 * The first pass makes sure allocations are spread fairly within the
2101 * local node. However, the local node might have free pages left
2102 * after the fairness batches are exhausted, and remote zones haven't
2103 * even been considered yet. Try once more without fairness, and
2104 * include remote zones now, before entering the slowpath and waking
2105 * kswapd: prefer spilling to a remote zone over swapping locally.
2107 if (alloc_flags & ALLOC_FAIR) {
2108 alloc_flags &= ~ALLOC_FAIR;
2109 if (nr_fair_skipped) {
2110 zonelist_rescan = true;
2111 reset_alloc_batches(preferred_zone);
2113 if (nr_online_nodes > 1)
2114 zonelist_rescan = true;
2117 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) {
2118 /* Disable zlc cache for second zonelist scan */
2120 zonelist_rescan = true;
2123 if (zonelist_rescan)
2130 * Large machines with many possible nodes should not always dump per-node
2131 * meminfo in irq context.
2133 static inline bool should_suppress_show_mem(void)
2138 ret = in_interrupt();
2143 static DEFINE_RATELIMIT_STATE(nopage_rs,
2144 DEFAULT_RATELIMIT_INTERVAL,
2145 DEFAULT_RATELIMIT_BURST);
2147 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2149 unsigned int filter = SHOW_MEM_FILTER_NODES;
2151 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2152 debug_guardpage_minorder() > 0)
2156 * This documents exceptions given to allocations in certain
2157 * contexts that are allowed to allocate outside current's set
2160 if (!(gfp_mask & __GFP_NOMEMALLOC))
2161 if (test_thread_flag(TIF_MEMDIE) ||
2162 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2163 filter &= ~SHOW_MEM_FILTER_NODES;
2164 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2165 filter &= ~SHOW_MEM_FILTER_NODES;
2168 struct va_format vaf;
2171 va_start(args, fmt);
2176 pr_warn("%pV", &vaf);
2181 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2182 current->comm, order, gfp_mask);
2185 if (!should_suppress_show_mem())
2190 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2191 unsigned long did_some_progress,
2192 unsigned long pages_reclaimed)
2194 /* Do not loop if specifically requested */
2195 if (gfp_mask & __GFP_NORETRY)
2198 /* Always retry if specifically requested */
2199 if (gfp_mask & __GFP_NOFAIL)
2203 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2204 * making forward progress without invoking OOM. Suspend also disables
2205 * storage devices so kswapd will not help. Bail if we are suspending.
2207 if (!did_some_progress && pm_suspended_storage())
2211 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2212 * means __GFP_NOFAIL, but that may not be true in other
2215 if (order <= PAGE_ALLOC_COSTLY_ORDER)
2219 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2220 * specified, then we retry until we no longer reclaim any pages
2221 * (above), or we've reclaimed an order of pages at least as
2222 * large as the allocation's order. In both cases, if the
2223 * allocation still fails, we stop retrying.
2225 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
2231 static inline struct page *
2232 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2233 struct zonelist *zonelist, enum zone_type high_zoneidx,
2234 nodemask_t *nodemask, struct zone *preferred_zone,
2235 int classzone_idx, int migratetype)
2239 /* Acquire the per-zone oom lock for each zone */
2240 if (!oom_zonelist_trylock(zonelist, gfp_mask)) {
2241 schedule_timeout_uninterruptible(1);
2246 * PM-freezer should be notified that there might be an OOM killer on
2247 * its way to kill and wake somebody up. This is too early and we might
2248 * end up not killing anything but false positives are acceptable.
2249 * See freeze_processes.
2254 * Go through the zonelist yet one more time, keep very high watermark
2255 * here, this is only to catch a parallel oom killing, we must fail if
2256 * we're still under heavy pressure.
2258 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
2259 order, zonelist, high_zoneidx,
2260 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2261 preferred_zone, classzone_idx, migratetype);
2265 if (!(gfp_mask & __GFP_NOFAIL)) {
2266 /* The OOM killer will not help higher order allocs */
2267 if (order > PAGE_ALLOC_COSTLY_ORDER)
2269 /* The OOM killer does not needlessly kill tasks for lowmem */
2270 if (high_zoneidx < ZONE_NORMAL)
2273 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2274 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2275 * The caller should handle page allocation failure by itself if
2276 * it specifies __GFP_THISNODE.
2277 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2279 if (gfp_mask & __GFP_THISNODE)
2282 /* Exhausted what can be done so it's blamo time */
2283 out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2286 oom_zonelist_unlock(zonelist, gfp_mask);
2290 #ifdef CONFIG_COMPACTION
2291 /* Try memory compaction for high-order allocations before reclaim */
2292 static struct page *
2293 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2294 struct zonelist *zonelist, enum zone_type high_zoneidx,
2295 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2296 int classzone_idx, int migratetype, enum migrate_mode mode,
2297 int *contended_compaction, bool *deferred_compaction)
2299 struct zone *last_compact_zone = NULL;
2300 unsigned long compact_result;
2306 current->flags |= PF_MEMALLOC;
2307 compact_result = try_to_compact_pages(zonelist, order, gfp_mask,
2309 contended_compaction,
2310 &last_compact_zone);
2311 current->flags &= ~PF_MEMALLOC;
2313 switch (compact_result) {
2314 case COMPACT_DEFERRED:
2315 *deferred_compaction = true;
2317 case COMPACT_SKIPPED:
2324 * At least in one zone compaction wasn't deferred or skipped, so let's
2325 * count a compaction stall
2327 count_vm_event(COMPACTSTALL);
2329 /* Page migration frees to the PCP lists but we want merging */
2330 drain_pages(get_cpu());
2333 page = get_page_from_freelist(gfp_mask, nodemask,
2334 order, zonelist, high_zoneidx,
2335 alloc_flags & ~ALLOC_NO_WATERMARKS,
2336 preferred_zone, classzone_idx, migratetype);
2339 struct zone *zone = page_zone(page);
2341 zone->compact_blockskip_flush = false;
2342 compaction_defer_reset(zone, order, true);
2343 count_vm_event(COMPACTSUCCESS);
2348 * last_compact_zone is where try_to_compact_pages thought allocation
2349 * should succeed, so it did not defer compaction. But here we know
2350 * that it didn't succeed, so we do the defer.
2352 if (last_compact_zone && mode != MIGRATE_ASYNC)
2353 defer_compaction(last_compact_zone, order);
2356 * It's bad if compaction run occurs and fails. The most likely reason
2357 * is that pages exist, but not enough to satisfy watermarks.
2359 count_vm_event(COMPACTFAIL);
2366 static inline struct page *
2367 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2368 struct zonelist *zonelist, enum zone_type high_zoneidx,
2369 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2370 int classzone_idx, int migratetype, enum migrate_mode mode,
2371 int *contended_compaction, bool *deferred_compaction)
2375 #endif /* CONFIG_COMPACTION */
2377 /* Perform direct synchronous page reclaim */
2379 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
2380 nodemask_t *nodemask)
2382 struct reclaim_state reclaim_state;
2387 /* We now go into synchronous reclaim */
2388 cpuset_memory_pressure_bump();
2389 current->flags |= PF_MEMALLOC;
2390 lockdep_set_current_reclaim_state(gfp_mask);
2391 reclaim_state.reclaimed_slab = 0;
2392 current->reclaim_state = &reclaim_state;
2394 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2396 current->reclaim_state = NULL;
2397 lockdep_clear_current_reclaim_state();
2398 current->flags &= ~PF_MEMALLOC;
2405 /* The really slow allocator path where we enter direct reclaim */
2406 static inline struct page *
2407 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2408 struct zonelist *zonelist, enum zone_type high_zoneidx,
2409 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2410 int classzone_idx, int migratetype, unsigned long *did_some_progress)
2412 struct page *page = NULL;
2413 bool drained = false;
2415 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
2417 if (unlikely(!(*did_some_progress)))
2420 /* After successful reclaim, reconsider all zones for allocation */
2421 if (IS_ENABLED(CONFIG_NUMA))
2422 zlc_clear_zones_full(zonelist);
2425 page = get_page_from_freelist(gfp_mask, nodemask, order,
2426 zonelist, high_zoneidx,
2427 alloc_flags & ~ALLOC_NO_WATERMARKS,
2428 preferred_zone, classzone_idx,
2432 * If an allocation failed after direct reclaim, it could be because
2433 * pages are pinned on the per-cpu lists. Drain them and try again
2435 if (!page && !drained) {
2445 * This is called in the allocator slow-path if the allocation request is of
2446 * sufficient urgency to ignore watermarks and take other desperate measures
2448 static inline struct page *
2449 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2450 struct zonelist *zonelist, enum zone_type high_zoneidx,
2451 nodemask_t *nodemask, struct zone *preferred_zone,
2452 int classzone_idx, int migratetype)
2457 page = get_page_from_freelist(gfp_mask, nodemask, order,
2458 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2459 preferred_zone, classzone_idx, migratetype);
2461 if (!page && gfp_mask & __GFP_NOFAIL)
2462 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2463 } while (!page && (gfp_mask & __GFP_NOFAIL));
2468 static void wake_all_kswapds(unsigned int order,
2469 struct zonelist *zonelist,
2470 enum zone_type high_zoneidx,
2471 struct zone *preferred_zone,
2472 nodemask_t *nodemask)
2477 for_each_zone_zonelist_nodemask(zone, z, zonelist,
2478 high_zoneidx, nodemask)
2479 wakeup_kswapd(zone, order, zone_idx(preferred_zone));
2483 gfp_to_alloc_flags(gfp_t gfp_mask)
2485 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2486 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
2488 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2489 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2492 * The caller may dip into page reserves a bit more if the caller
2493 * cannot run direct reclaim, or if the caller has realtime scheduling
2494 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2495 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2497 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2501 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2502 * if it can't schedule.
2504 if (!(gfp_mask & __GFP_NOMEMALLOC))
2505 alloc_flags |= ALLOC_HARDER;
2507 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2508 * comment for __cpuset_node_allowed_softwall().
2510 alloc_flags &= ~ALLOC_CPUSET;
2511 } else if (unlikely(rt_task(current)) && !in_interrupt())
2512 alloc_flags |= ALLOC_HARDER;
2514 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2515 if (gfp_mask & __GFP_MEMALLOC)
2516 alloc_flags |= ALLOC_NO_WATERMARKS;
2517 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2518 alloc_flags |= ALLOC_NO_WATERMARKS;
2519 else if (!in_interrupt() &&
2520 ((current->flags & PF_MEMALLOC) ||
2521 unlikely(test_thread_flag(TIF_MEMDIE))))
2522 alloc_flags |= ALLOC_NO_WATERMARKS;
2525 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2526 alloc_flags |= ALLOC_CMA;
2531 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2533 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2536 static inline struct page *
2537 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2538 struct zonelist *zonelist, enum zone_type high_zoneidx,
2539 nodemask_t *nodemask, struct zone *preferred_zone,
2540 int classzone_idx, int migratetype)
2542 const gfp_t wait = gfp_mask & __GFP_WAIT;
2543 struct page *page = NULL;
2545 unsigned long pages_reclaimed = 0;
2546 unsigned long did_some_progress;
2547 enum migrate_mode migration_mode = MIGRATE_ASYNC;
2548 bool deferred_compaction = false;
2549 int contended_compaction = COMPACT_CONTENDED_NONE;
2552 * In the slowpath, we sanity check order to avoid ever trying to
2553 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2554 * be using allocators in order of preference for an area that is
2557 if (order >= MAX_ORDER) {
2558 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2563 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2564 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2565 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2566 * using a larger set of nodes after it has established that the
2567 * allowed per node queues are empty and that nodes are
2570 if (IS_ENABLED(CONFIG_NUMA) &&
2571 (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2575 if (!(gfp_mask & __GFP_NO_KSWAPD))
2576 wake_all_kswapds(order, zonelist, high_zoneidx,
2577 preferred_zone, nodemask);
2580 * OK, we're below the kswapd watermark and have kicked background
2581 * reclaim. Now things get more complex, so set up alloc_flags according
2582 * to how we want to proceed.
2584 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2587 * Find the true preferred zone if the allocation is unconstrained by
2590 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) {
2591 struct zoneref *preferred_zoneref;
2592 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
2593 NULL, &preferred_zone);
2594 classzone_idx = zonelist_zone_idx(preferred_zoneref);
2598 /* This is the last chance, in general, before the goto nopage. */
2599 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2600 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2601 preferred_zone, classzone_idx, migratetype);
2605 /* Allocate without watermarks if the context allows */
2606 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2608 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2609 * the allocation is high priority and these type of
2610 * allocations are system rather than user orientated
2612 zonelist = node_zonelist(numa_node_id(), gfp_mask);
2614 page = __alloc_pages_high_priority(gfp_mask, order,
2615 zonelist, high_zoneidx, nodemask,
2616 preferred_zone, classzone_idx, migratetype);
2622 /* Atomic allocations - we can't balance anything */
2625 * All existing users of the deprecated __GFP_NOFAIL are
2626 * blockable, so warn of any new users that actually allow this
2627 * type of allocation to fail.
2629 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
2633 /* Avoid recursion of direct reclaim */
2634 if (current->flags & PF_MEMALLOC)
2637 /* Avoid allocations with no watermarks from looping endlessly */
2638 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2642 * Try direct compaction. The first pass is asynchronous. Subsequent
2643 * attempts after direct reclaim are synchronous
2645 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
2646 high_zoneidx, nodemask, alloc_flags,
2648 classzone_idx, migratetype,
2649 migration_mode, &contended_compaction,
2650 &deferred_compaction);
2654 /* Checks for THP-specific high-order allocations */
2655 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) {
2657 * If compaction is deferred for high-order allocations, it is
2658 * because sync compaction recently failed. If this is the case
2659 * and the caller requested a THP allocation, we do not want
2660 * to heavily disrupt the system, so we fail the allocation
2661 * instead of entering direct reclaim.
2663 if (deferred_compaction)
2667 * In all zones where compaction was attempted (and not
2668 * deferred or skipped), lock contention has been detected.
2669 * For THP allocation we do not want to disrupt the others
2670 * so we fallback to base pages instead.
2672 if (contended_compaction == COMPACT_CONTENDED_LOCK)
2676 * If compaction was aborted due to need_resched(), we do not
2677 * want to further increase allocation latency, unless it is
2678 * khugepaged trying to collapse.
2680 if (contended_compaction == COMPACT_CONTENDED_SCHED
2681 && !(current->flags & PF_KTHREAD))
2686 * It can become very expensive to allocate transparent hugepages at
2687 * fault, so use asynchronous memory compaction for THP unless it is
2688 * khugepaged trying to collapse.
2690 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE ||
2691 (current->flags & PF_KTHREAD))
2692 migration_mode = MIGRATE_SYNC_LIGHT;
2694 /* Try direct reclaim and then allocating */
2695 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2696 zonelist, high_zoneidx,
2698 alloc_flags, preferred_zone,
2699 classzone_idx, migratetype,
2700 &did_some_progress);
2705 * If we failed to make any progress reclaiming, then we are
2706 * running out of options and have to consider going OOM
2708 if (!did_some_progress) {
2709 if (oom_gfp_allowed(gfp_mask)) {
2710 if (oom_killer_disabled)
2712 /* Coredumps can quickly deplete all memory reserves */
2713 if ((current->flags & PF_DUMPCORE) &&
2714 !(gfp_mask & __GFP_NOFAIL))
2716 page = __alloc_pages_may_oom(gfp_mask, order,
2717 zonelist, high_zoneidx,
2718 nodemask, preferred_zone,
2719 classzone_idx, migratetype);
2723 if (!(gfp_mask & __GFP_NOFAIL)) {
2725 * The oom killer is not called for high-order
2726 * allocations that may fail, so if no progress
2727 * is being made, there are no other options and
2728 * retrying is unlikely to help.
2730 if (order > PAGE_ALLOC_COSTLY_ORDER)
2733 * The oom killer is not called for lowmem
2734 * allocations to prevent needlessly killing
2737 if (high_zoneidx < ZONE_NORMAL)
2745 /* Check if we should retry the allocation */
2746 pages_reclaimed += did_some_progress;
2747 if (should_alloc_retry(gfp_mask, order, did_some_progress,
2749 /* Wait for some write requests to complete then retry */
2750 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2754 * High-order allocations do not necessarily loop after
2755 * direct reclaim and reclaim/compaction depends on compaction
2756 * being called after reclaim so call directly if necessary
2758 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
2759 high_zoneidx, nodemask, alloc_flags,
2761 classzone_idx, migratetype,
2762 migration_mode, &contended_compaction,
2763 &deferred_compaction);
2769 warn_alloc_failed(gfp_mask, order, NULL);
2772 if (kmemcheck_enabled)
2773 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2779 * This is the 'heart' of the zoned buddy allocator.
2782 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2783 struct zonelist *zonelist, nodemask_t *nodemask)
2785 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2786 struct zone *preferred_zone;
2787 struct zoneref *preferred_zoneref;
2788 struct page *page = NULL;
2789 int migratetype = gfpflags_to_migratetype(gfp_mask);
2790 unsigned int cpuset_mems_cookie;
2791 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
2794 gfp_mask &= gfp_allowed_mask;
2796 lockdep_trace_alloc(gfp_mask);
2798 might_sleep_if(gfp_mask & __GFP_WAIT);
2800 if (should_fail_alloc_page(gfp_mask, order))
2804 * Check the zones suitable for the gfp_mask contain at least one
2805 * valid zone. It's possible to have an empty zonelist as a result
2806 * of GFP_THISNODE and a memoryless node
2808 if (unlikely(!zonelist->_zonerefs->zone))
2811 if (IS_ENABLED(CONFIG_CMA) && migratetype == MIGRATE_MOVABLE)
2812 alloc_flags |= ALLOC_CMA;
2815 cpuset_mems_cookie = read_mems_allowed_begin();
2817 /* The preferred zone is used for statistics later */
2818 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
2819 nodemask ? : &cpuset_current_mems_allowed,
2821 if (!preferred_zone)
2823 classzone_idx = zonelist_zone_idx(preferred_zoneref);
2825 /* First allocation attempt */
2826 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2827 zonelist, high_zoneidx, alloc_flags,
2828 preferred_zone, classzone_idx, migratetype);
2829 if (unlikely(!page)) {
2831 * Runtime PM, block IO and its error handling path
2832 * can deadlock because I/O on the device might not
2835 gfp_mask = memalloc_noio_flags(gfp_mask);
2836 page = __alloc_pages_slowpath(gfp_mask, order,
2837 zonelist, high_zoneidx, nodemask,
2838 preferred_zone, classzone_idx, migratetype);
2841 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2845 * When updating a task's mems_allowed, it is possible to race with
2846 * parallel threads in such a way that an allocation can fail while
2847 * the mask is being updated. If a page allocation is about to fail,
2848 * check if the cpuset changed during allocation and if so, retry.
2850 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2855 EXPORT_SYMBOL(__alloc_pages_nodemask);
2858 * Common helper functions.
2860 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2865 * __get_free_pages() returns a 32-bit address, which cannot represent
2868 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2870 page = alloc_pages(gfp_mask, order);
2873 return (unsigned long) page_address(page);
2875 EXPORT_SYMBOL(__get_free_pages);
2877 unsigned long get_zeroed_page(gfp_t gfp_mask)
2879 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2881 EXPORT_SYMBOL(get_zeroed_page);
2883 void __free_pages(struct page *page, unsigned int order)
2885 if (put_page_testzero(page)) {
2887 free_hot_cold_page(page, false);
2889 __free_pages_ok(page, order);
2893 EXPORT_SYMBOL(__free_pages);
2895 void free_pages(unsigned long addr, unsigned int order)
2898 VM_BUG_ON(!virt_addr_valid((void *)addr));
2899 __free_pages(virt_to_page((void *)addr), order);
2903 EXPORT_SYMBOL(free_pages);
2906 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
2907 * of the current memory cgroup.
2909 * It should be used when the caller would like to use kmalloc, but since the
2910 * allocation is large, it has to fall back to the page allocator.
2912 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
2915 struct mem_cgroup *memcg = NULL;
2917 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2919 page = alloc_pages(gfp_mask, order);
2920 memcg_kmem_commit_charge(page, memcg, order);
2924 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
2927 struct mem_cgroup *memcg = NULL;
2929 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2931 page = alloc_pages_node(nid, gfp_mask, order);
2932 memcg_kmem_commit_charge(page, memcg, order);
2937 * __free_kmem_pages and free_kmem_pages will free pages allocated with
2940 void __free_kmem_pages(struct page *page, unsigned int order)
2942 memcg_kmem_uncharge_pages(page, order);
2943 __free_pages(page, order);
2946 void free_kmem_pages(unsigned long addr, unsigned int order)
2949 VM_BUG_ON(!virt_addr_valid((void *)addr));
2950 __free_kmem_pages(virt_to_page((void *)addr), order);
2954 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2957 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2958 unsigned long used = addr + PAGE_ALIGN(size);
2960 split_page(virt_to_page((void *)addr), order);
2961 while (used < alloc_end) {
2966 return (void *)addr;
2970 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2971 * @size: the number of bytes to allocate
2972 * @gfp_mask: GFP flags for the allocation
2974 * This function is similar to alloc_pages(), except that it allocates the
2975 * minimum number of pages to satisfy the request. alloc_pages() can only
2976 * allocate memory in power-of-two pages.
2978 * This function is also limited by MAX_ORDER.
2980 * Memory allocated by this function must be released by free_pages_exact().
2982 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2984 unsigned int order = get_order(size);
2987 addr = __get_free_pages(gfp_mask, order);
2988 return make_alloc_exact(addr, order, size);
2990 EXPORT_SYMBOL(alloc_pages_exact);
2993 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2995 * @nid: the preferred node ID where memory should be allocated
2996 * @size: the number of bytes to allocate
2997 * @gfp_mask: GFP flags for the allocation
2999 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3001 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
3004 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3006 unsigned order = get_order(size);
3007 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3010 return make_alloc_exact((unsigned long)page_address(p), order, size);
3014 * free_pages_exact - release memory allocated via alloc_pages_exact()
3015 * @virt: the value returned by alloc_pages_exact.
3016 * @size: size of allocation, same value as passed to alloc_pages_exact().
3018 * Release the memory allocated by a previous call to alloc_pages_exact.
3020 void free_pages_exact(void *virt, size_t size)
3022 unsigned long addr = (unsigned long)virt;
3023 unsigned long end = addr + PAGE_ALIGN(size);
3025 while (addr < end) {
3030 EXPORT_SYMBOL(free_pages_exact);
3033 * nr_free_zone_pages - count number of pages beyond high watermark
3034 * @offset: The zone index of the highest zone
3036 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3037 * high watermark within all zones at or below a given zone index. For each
3038 * zone, the number of pages is calculated as:
3039 * managed_pages - high_pages
3041 static unsigned long nr_free_zone_pages(int offset)
3046 /* Just pick one node, since fallback list is circular */
3047 unsigned long sum = 0;
3049 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3051 for_each_zone_zonelist(zone, z, zonelist, offset) {
3052 unsigned long size = zone->managed_pages;
3053 unsigned long high = high_wmark_pages(zone);
3062 * nr_free_buffer_pages - count number of pages beyond high watermark
3064 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3065 * watermark within ZONE_DMA and ZONE_NORMAL.
3067 unsigned long nr_free_buffer_pages(void)
3069 return nr_free_zone_pages(gfp_zone(GFP_USER));
3071 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3074 * nr_free_pagecache_pages - count number of pages beyond high watermark
3076 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3077 * high watermark within all zones.
3079 unsigned long nr_free_pagecache_pages(void)
3081 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3084 static inline void show_node(struct zone *zone)
3086 if (IS_ENABLED(CONFIG_NUMA))
3087 printk("Node %d ", zone_to_nid(zone));
3090 void si_meminfo(struct sysinfo *val)
3092 val->totalram = totalram_pages;
3093 val->sharedram = global_page_state(NR_SHMEM);
3094 val->freeram = global_page_state(NR_FREE_PAGES);
3095 val->bufferram = nr_blockdev_pages();
3096 val->totalhigh = totalhigh_pages;
3097 val->freehigh = nr_free_highpages();
3098 val->mem_unit = PAGE_SIZE;
3101 EXPORT_SYMBOL(si_meminfo);
3104 void si_meminfo_node(struct sysinfo *val, int nid)
3106 int zone_type; /* needs to be signed */
3107 unsigned long managed_pages = 0;
3108 pg_data_t *pgdat = NODE_DATA(nid);
3110 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3111 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3112 val->totalram = managed_pages;
3113 val->sharedram = node_page_state(nid, NR_SHMEM);
3114 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3115 #ifdef CONFIG_HIGHMEM
3116 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3117 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3123 val->mem_unit = PAGE_SIZE;
3128 * Determine whether the node should be displayed or not, depending on whether
3129 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3131 bool skip_free_areas_node(unsigned int flags, int nid)
3134 unsigned int cpuset_mems_cookie;
3136 if (!(flags & SHOW_MEM_FILTER_NODES))
3140 cpuset_mems_cookie = read_mems_allowed_begin();
3141 ret = !node_isset(nid, cpuset_current_mems_allowed);
3142 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3147 #define K(x) ((x) << (PAGE_SHIFT-10))
3149 static void show_migration_types(unsigned char type)
3151 static const char types[MIGRATE_TYPES] = {
3152 [MIGRATE_UNMOVABLE] = 'U',
3153 [MIGRATE_RECLAIMABLE] = 'E',
3154 [MIGRATE_MOVABLE] = 'M',
3155 [MIGRATE_RESERVE] = 'R',
3157 [MIGRATE_CMA] = 'C',
3159 #ifdef CONFIG_MEMORY_ISOLATION
3160 [MIGRATE_ISOLATE] = 'I',
3163 char tmp[MIGRATE_TYPES + 1];
3167 for (i = 0; i < MIGRATE_TYPES; i++) {
3168 if (type & (1 << i))
3173 printk("(%s) ", tmp);
3177 * Show free area list (used inside shift_scroll-lock stuff)
3178 * We also calculate the percentage fragmentation. We do this by counting the
3179 * memory on each free list with the exception of the first item on the list.
3180 * Suppresses nodes that are not allowed by current's cpuset if
3181 * SHOW_MEM_FILTER_NODES is passed.
3183 void show_free_areas(unsigned int filter)
3188 for_each_populated_zone(zone) {
3189 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3192 printk("%s per-cpu:\n", zone->name);
3194 for_each_online_cpu(cpu) {
3195 struct per_cpu_pageset *pageset;
3197 pageset = per_cpu_ptr(zone->pageset, cpu);
3199 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
3200 cpu, pageset->pcp.high,
3201 pageset->pcp.batch, pageset->pcp.count);
3205 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3206 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3208 " dirty:%lu writeback:%lu unstable:%lu\n"
3209 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3210 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3212 global_page_state(NR_ACTIVE_ANON),
3213 global_page_state(NR_INACTIVE_ANON),
3214 global_page_state(NR_ISOLATED_ANON),
3215 global_page_state(NR_ACTIVE_FILE),
3216 global_page_state(NR_INACTIVE_FILE),
3217 global_page_state(NR_ISOLATED_FILE),
3218 global_page_state(NR_UNEVICTABLE),
3219 global_page_state(NR_FILE_DIRTY),
3220 global_page_state(NR_WRITEBACK),
3221 global_page_state(NR_UNSTABLE_NFS),
3222 global_page_state(NR_FREE_PAGES),
3223 global_page_state(NR_SLAB_RECLAIMABLE),
3224 global_page_state(NR_SLAB_UNRECLAIMABLE),
3225 global_page_state(NR_FILE_MAPPED),
3226 global_page_state(NR_SHMEM),
3227 global_page_state(NR_PAGETABLE),
3228 global_page_state(NR_BOUNCE),
3229 global_page_state(NR_FREE_CMA_PAGES));
3231 for_each_populated_zone(zone) {
3234 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3242 " active_anon:%lukB"
3243 " inactive_anon:%lukB"
3244 " active_file:%lukB"
3245 " inactive_file:%lukB"
3246 " unevictable:%lukB"
3247 " isolated(anon):%lukB"
3248 " isolated(file):%lukB"
3256 " slab_reclaimable:%lukB"
3257 " slab_unreclaimable:%lukB"
3258 " kernel_stack:%lukB"
3263 " writeback_tmp:%lukB"
3264 " pages_scanned:%lu"
3265 " all_unreclaimable? %s"
3268 K(zone_page_state(zone, NR_FREE_PAGES)),
3269 K(min_wmark_pages(zone)),
3270 K(low_wmark_pages(zone)),
3271 K(high_wmark_pages(zone)),
3272 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3273 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3274 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3275 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3276 K(zone_page_state(zone, NR_UNEVICTABLE)),
3277 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3278 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3279 K(zone->present_pages),
3280 K(zone->managed_pages),
3281 K(zone_page_state(zone, NR_MLOCK)),
3282 K(zone_page_state(zone, NR_FILE_DIRTY)),
3283 K(zone_page_state(zone, NR_WRITEBACK)),
3284 K(zone_page_state(zone, NR_FILE_MAPPED)),
3285 K(zone_page_state(zone, NR_SHMEM)),
3286 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3287 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3288 zone_page_state(zone, NR_KERNEL_STACK) *
3290 K(zone_page_state(zone, NR_PAGETABLE)),
3291 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3292 K(zone_page_state(zone, NR_BOUNCE)),
3293 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3294 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3295 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3296 (!zone_reclaimable(zone) ? "yes" : "no")
3298 printk("lowmem_reserve[]:");
3299 for (i = 0; i < MAX_NR_ZONES; i++)
3300 printk(" %ld", zone->lowmem_reserve[i]);
3304 for_each_populated_zone(zone) {
3305 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3306 unsigned char types[MAX_ORDER];
3308 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3311 printk("%s: ", zone->name);
3313 spin_lock_irqsave(&zone->lock, flags);
3314 for (order = 0; order < MAX_ORDER; order++) {
3315 struct free_area *area = &zone->free_area[order];
3318 nr[order] = area->nr_free;
3319 total += nr[order] << order;
3322 for (type = 0; type < MIGRATE_TYPES; type++) {
3323 if (!list_empty(&area->free_list[type]))
3324 types[order] |= 1 << type;
3327 spin_unlock_irqrestore(&zone->lock, flags);
3328 for (order = 0; order < MAX_ORDER; order++) {
3329 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3331 show_migration_types(types[order]);
3333 printk("= %lukB\n", K(total));
3336 hugetlb_show_meminfo();
3338 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3340 show_swap_cache_info();
3343 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3345 zoneref->zone = zone;
3346 zoneref->zone_idx = zone_idx(zone);
3350 * Builds allocation fallback zone lists.
3352 * Add all populated zones of a node to the zonelist.
3354 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3358 enum zone_type zone_type = MAX_NR_ZONES;
3362 zone = pgdat->node_zones + zone_type;
3363 if (populated_zone(zone)) {
3364 zoneref_set_zone(zone,
3365 &zonelist->_zonerefs[nr_zones++]);
3366 check_highest_zone(zone_type);
3368 } while (zone_type);
3376 * 0 = automatic detection of better ordering.
3377 * 1 = order by ([node] distance, -zonetype)
3378 * 2 = order by (-zonetype, [node] distance)
3380 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3381 * the same zonelist. So only NUMA can configure this param.
3383 #define ZONELIST_ORDER_DEFAULT 0
3384 #define ZONELIST_ORDER_NODE 1
3385 #define ZONELIST_ORDER_ZONE 2
3387 /* zonelist order in the kernel.
3388 * set_zonelist_order() will set this to NODE or ZONE.
3390 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3391 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3395 /* The value user specified ....changed by config */
3396 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3397 /* string for sysctl */
3398 #define NUMA_ZONELIST_ORDER_LEN 16
3399 char numa_zonelist_order[16] = "default";
3402 * interface for configure zonelist ordering.
3403 * command line option "numa_zonelist_order"
3404 * = "[dD]efault - default, automatic configuration.
3405 * = "[nN]ode - order by node locality, then by zone within node
3406 * = "[zZ]one - order by zone, then by locality within zone
3409 static int __parse_numa_zonelist_order(char *s)
3411 if (*s == 'd' || *s == 'D') {
3412 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3413 } else if (*s == 'n' || *s == 'N') {
3414 user_zonelist_order = ZONELIST_ORDER_NODE;
3415 } else if (*s == 'z' || *s == 'Z') {
3416 user_zonelist_order = ZONELIST_ORDER_ZONE;
3419 "Ignoring invalid numa_zonelist_order value: "
3426 static __init int setup_numa_zonelist_order(char *s)
3433 ret = __parse_numa_zonelist_order(s);
3435 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3439 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3442 * sysctl handler for numa_zonelist_order
3444 int numa_zonelist_order_handler(struct ctl_table *table, int write,
3445 void __user *buffer, size_t *length,
3448 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3450 static DEFINE_MUTEX(zl_order_mutex);
3452 mutex_lock(&zl_order_mutex);
3454 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3458 strcpy(saved_string, (char *)table->data);
3460 ret = proc_dostring(table, write, buffer, length, ppos);
3464 int oldval = user_zonelist_order;
3466 ret = __parse_numa_zonelist_order((char *)table->data);
3469 * bogus value. restore saved string
3471 strncpy((char *)table->data, saved_string,
3472 NUMA_ZONELIST_ORDER_LEN);
3473 user_zonelist_order = oldval;
3474 } else if (oldval != user_zonelist_order) {
3475 mutex_lock(&zonelists_mutex);
3476 build_all_zonelists(NULL, NULL);
3477 mutex_unlock(&zonelists_mutex);
3481 mutex_unlock(&zl_order_mutex);
3486 #define MAX_NODE_LOAD (nr_online_nodes)
3487 static int node_load[MAX_NUMNODES];
3490 * find_next_best_node - find the next node that should appear in a given node's fallback list
3491 * @node: node whose fallback list we're appending
3492 * @used_node_mask: nodemask_t of already used nodes
3494 * We use a number of factors to determine which is the next node that should
3495 * appear on a given node's fallback list. The node should not have appeared
3496 * already in @node's fallback list, and it should be the next closest node
3497 * according to the distance array (which contains arbitrary distance values
3498 * from each node to each node in the system), and should also prefer nodes
3499 * with no CPUs, since presumably they'll have very little allocation pressure
3500 * on them otherwise.
3501 * It returns -1 if no node is found.
3503 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3506 int min_val = INT_MAX;
3507 int best_node = NUMA_NO_NODE;
3508 const struct cpumask *tmp = cpumask_of_node(0);
3510 /* Use the local node if we haven't already */
3511 if (!node_isset(node, *used_node_mask)) {
3512 node_set(node, *used_node_mask);
3516 for_each_node_state(n, N_MEMORY) {
3518 /* Don't want a node to appear more than once */
3519 if (node_isset(n, *used_node_mask))
3522 /* Use the distance array to find the distance */
3523 val = node_distance(node, n);
3525 /* Penalize nodes under us ("prefer the next node") */
3528 /* Give preference to headless and unused nodes */
3529 tmp = cpumask_of_node(n);
3530 if (!cpumask_empty(tmp))
3531 val += PENALTY_FOR_NODE_WITH_CPUS;
3533 /* Slight preference for less loaded node */
3534 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3535 val += node_load[n];
3537 if (val < min_val) {
3544 node_set(best_node, *used_node_mask);
3551 * Build zonelists ordered by node and zones within node.
3552 * This results in maximum locality--normal zone overflows into local
3553 * DMA zone, if any--but risks exhausting DMA zone.
3555 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3558 struct zonelist *zonelist;
3560 zonelist = &pgdat->node_zonelists[0];
3561 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3563 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3564 zonelist->_zonerefs[j].zone = NULL;
3565 zonelist->_zonerefs[j].zone_idx = 0;
3569 * Build gfp_thisnode zonelists
3571 static void build_thisnode_zonelists(pg_data_t *pgdat)
3574 struct zonelist *zonelist;
3576 zonelist = &pgdat->node_zonelists[1];
3577 j = build_zonelists_node(pgdat, zonelist, 0);
3578 zonelist->_zonerefs[j].zone = NULL;
3579 zonelist->_zonerefs[j].zone_idx = 0;
3583 * Build zonelists ordered by zone and nodes within zones.
3584 * This results in conserving DMA zone[s] until all Normal memory is
3585 * exhausted, but results in overflowing to remote node while memory
3586 * may still exist in local DMA zone.
3588 static int node_order[MAX_NUMNODES];
3590 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3593 int zone_type; /* needs to be signed */
3595 struct zonelist *zonelist;
3597 zonelist = &pgdat->node_zonelists[0];
3599 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3600 for (j = 0; j < nr_nodes; j++) {
3601 node = node_order[j];
3602 z = &NODE_DATA(node)->node_zones[zone_type];
3603 if (populated_zone(z)) {
3605 &zonelist->_zonerefs[pos++]);
3606 check_highest_zone(zone_type);
3610 zonelist->_zonerefs[pos].zone = NULL;
3611 zonelist->_zonerefs[pos].zone_idx = 0;
3614 #if defined(CONFIG_64BIT)
3616 * Devices that require DMA32/DMA are relatively rare and do not justify a
3617 * penalty to every machine in case the specialised case applies. Default
3618 * to Node-ordering on 64-bit NUMA machines
3620 static int default_zonelist_order(void)
3622 return ZONELIST_ORDER_NODE;
3626 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
3627 * by the kernel. If processes running on node 0 deplete the low memory zone
3628 * then reclaim will occur more frequency increasing stalls and potentially
3629 * be easier to OOM if a large percentage of the zone is under writeback or
3630 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
3631 * Hence, default to zone ordering on 32-bit.
3633 static int default_zonelist_order(void)
3635 return ZONELIST_ORDER_ZONE;
3637 #endif /* CONFIG_64BIT */
3639 static void set_zonelist_order(void)
3641 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3642 current_zonelist_order = default_zonelist_order();
3644 current_zonelist_order = user_zonelist_order;
3647 static void build_zonelists(pg_data_t *pgdat)
3651 nodemask_t used_mask;
3652 int local_node, prev_node;
3653 struct zonelist *zonelist;
3654 int order = current_zonelist_order;
3656 /* initialize zonelists */
3657 for (i = 0; i < MAX_ZONELISTS; i++) {
3658 zonelist = pgdat->node_zonelists + i;
3659 zonelist->_zonerefs[0].zone = NULL;
3660 zonelist->_zonerefs[0].zone_idx = 0;
3663 /* NUMA-aware ordering of nodes */
3664 local_node = pgdat->node_id;
3665 load = nr_online_nodes;
3666 prev_node = local_node;
3667 nodes_clear(used_mask);
3669 memset(node_order, 0, sizeof(node_order));
3672 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3674 * We don't want to pressure a particular node.
3675 * So adding penalty to the first node in same
3676 * distance group to make it round-robin.
3678 if (node_distance(local_node, node) !=
3679 node_distance(local_node, prev_node))
3680 node_load[node] = load;
3684 if (order == ZONELIST_ORDER_NODE)
3685 build_zonelists_in_node_order(pgdat, node);
3687 node_order[j++] = node; /* remember order */
3690 if (order == ZONELIST_ORDER_ZONE) {
3691 /* calculate node order -- i.e., DMA last! */
3692 build_zonelists_in_zone_order(pgdat, j);
3695 build_thisnode_zonelists(pgdat);
3698 /* Construct the zonelist performance cache - see further mmzone.h */
3699 static void build_zonelist_cache(pg_data_t *pgdat)
3701 struct zonelist *zonelist;
3702 struct zonelist_cache *zlc;
3705 zonelist = &pgdat->node_zonelists[0];
3706 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3707 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3708 for (z = zonelist->_zonerefs; z->zone; z++)
3709 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3712 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3714 * Return node id of node used for "local" allocations.
3715 * I.e., first node id of first zone in arg node's generic zonelist.
3716 * Used for initializing percpu 'numa_mem', which is used primarily
3717 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3719 int local_memory_node(int node)
3723 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3724 gfp_zone(GFP_KERNEL),
3731 #else /* CONFIG_NUMA */
3733 static void set_zonelist_order(void)
3735 current_zonelist_order = ZONELIST_ORDER_ZONE;
3738 static void build_zonelists(pg_data_t *pgdat)
3740 int node, local_node;
3742 struct zonelist *zonelist;
3744 local_node = pgdat->node_id;
3746 zonelist = &pgdat->node_zonelists[0];
3747 j = build_zonelists_node(pgdat, zonelist, 0);
3750 * Now we build the zonelist so that it contains the zones
3751 * of all the other nodes.
3752 * We don't want to pressure a particular node, so when
3753 * building the zones for node N, we make sure that the
3754 * zones coming right after the local ones are those from
3755 * node N+1 (modulo N)
3757 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3758 if (!node_online(node))
3760 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3762 for (node = 0; node < local_node; node++) {
3763 if (!node_online(node))
3765 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3768 zonelist->_zonerefs[j].zone = NULL;
3769 zonelist->_zonerefs[j].zone_idx = 0;
3772 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3773 static void build_zonelist_cache(pg_data_t *pgdat)
3775 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3778 #endif /* CONFIG_NUMA */
3781 * Boot pageset table. One per cpu which is going to be used for all
3782 * zones and all nodes. The parameters will be set in such a way
3783 * that an item put on a list will immediately be handed over to
3784 * the buddy list. This is safe since pageset manipulation is done
3785 * with interrupts disabled.
3787 * The boot_pagesets must be kept even after bootup is complete for
3788 * unused processors and/or zones. They do play a role for bootstrapping
3789 * hotplugged processors.
3791 * zoneinfo_show() and maybe other functions do
3792 * not check if the processor is online before following the pageset pointer.
3793 * Other parts of the kernel may not check if the zone is available.
3795 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3796 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3797 static void setup_zone_pageset(struct zone *zone);
3800 * Global mutex to protect against size modification of zonelists
3801 * as well as to serialize pageset setup for the new populated zone.
3803 DEFINE_MUTEX(zonelists_mutex);
3805 /* return values int ....just for stop_machine() */
3806 static int __build_all_zonelists(void *data)
3810 pg_data_t *self = data;
3813 memset(node_load, 0, sizeof(node_load));
3816 if (self && !node_online(self->node_id)) {
3817 build_zonelists(self);
3818 build_zonelist_cache(self);
3821 for_each_online_node(nid) {
3822 pg_data_t *pgdat = NODE_DATA(nid);
3824 build_zonelists(pgdat);
3825 build_zonelist_cache(pgdat);
3829 * Initialize the boot_pagesets that are going to be used
3830 * for bootstrapping processors. The real pagesets for
3831 * each zone will be allocated later when the per cpu
3832 * allocator is available.
3834 * boot_pagesets are used also for bootstrapping offline
3835 * cpus if the system is already booted because the pagesets
3836 * are needed to initialize allocators on a specific cpu too.
3837 * F.e. the percpu allocator needs the page allocator which
3838 * needs the percpu allocator in order to allocate its pagesets
3839 * (a chicken-egg dilemma).
3841 for_each_possible_cpu(cpu) {
3842 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3844 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3846 * We now know the "local memory node" for each node--
3847 * i.e., the node of the first zone in the generic zonelist.
3848 * Set up numa_mem percpu variable for on-line cpus. During
3849 * boot, only the boot cpu should be on-line; we'll init the
3850 * secondary cpus' numa_mem as they come on-line. During
3851 * node/memory hotplug, we'll fixup all on-line cpus.
3853 if (cpu_online(cpu))
3854 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3862 * Called with zonelists_mutex held always
3863 * unless system_state == SYSTEM_BOOTING.
3865 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3867 set_zonelist_order();
3869 if (system_state == SYSTEM_BOOTING) {
3870 __build_all_zonelists(NULL);
3871 mminit_verify_zonelist();
3872 cpuset_init_current_mems_allowed();
3874 #ifdef CONFIG_MEMORY_HOTPLUG
3876 setup_zone_pageset(zone);
3878 /* we have to stop all cpus to guarantee there is no user
3880 stop_machine(__build_all_zonelists, pgdat, NULL);
3881 /* cpuset refresh routine should be here */
3883 vm_total_pages = nr_free_pagecache_pages();
3885 * Disable grouping by mobility if the number of pages in the
3886 * system is too low to allow the mechanism to work. It would be
3887 * more accurate, but expensive to check per-zone. This check is
3888 * made on memory-hotadd so a system can start with mobility
3889 * disabled and enable it later
3891 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3892 page_group_by_mobility_disabled = 1;
3894 page_group_by_mobility_disabled = 0;
3896 printk("Built %i zonelists in %s order, mobility grouping %s. "
3897 "Total pages: %ld\n",
3899 zonelist_order_name[current_zonelist_order],
3900 page_group_by_mobility_disabled ? "off" : "on",
3903 printk("Policy zone: %s\n", zone_names[policy_zone]);
3908 * Helper functions to size the waitqueue hash table.
3909 * Essentially these want to choose hash table sizes sufficiently
3910 * large so that collisions trying to wait on pages are rare.
3911 * But in fact, the number of active page waitqueues on typical
3912 * systems is ridiculously low, less than 200. So this is even
3913 * conservative, even though it seems large.
3915 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3916 * waitqueues, i.e. the size of the waitq table given the number of pages.
3918 #define PAGES_PER_WAITQUEUE 256
3920 #ifndef CONFIG_MEMORY_HOTPLUG
3921 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3923 unsigned long size = 1;
3925 pages /= PAGES_PER_WAITQUEUE;
3927 while (size < pages)
3931 * Once we have dozens or even hundreds of threads sleeping
3932 * on IO we've got bigger problems than wait queue collision.
3933 * Limit the size of the wait table to a reasonable size.
3935 size = min(size, 4096UL);
3937 return max(size, 4UL);
3941 * A zone's size might be changed by hot-add, so it is not possible to determine
3942 * a suitable size for its wait_table. So we use the maximum size now.
3944 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3946 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3947 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3948 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3950 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3951 * or more by the traditional way. (See above). It equals:
3953 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3954 * ia64(16K page size) : = ( 8G + 4M)byte.
3955 * powerpc (64K page size) : = (32G +16M)byte.
3957 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3964 * This is an integer logarithm so that shifts can be used later
3965 * to extract the more random high bits from the multiplicative
3966 * hash function before the remainder is taken.
3968 static inline unsigned long wait_table_bits(unsigned long size)
3974 * Check if a pageblock contains reserved pages
3976 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3980 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3981 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3988 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3989 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3990 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3991 * higher will lead to a bigger reserve which will get freed as contiguous
3992 * blocks as reclaim kicks in
3994 static void setup_zone_migrate_reserve(struct zone *zone)
3996 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3998 unsigned long block_migratetype;
4003 * Get the start pfn, end pfn and the number of blocks to reserve
4004 * We have to be careful to be aligned to pageblock_nr_pages to
4005 * make sure that we always check pfn_valid for the first page in
4008 start_pfn = zone->zone_start_pfn;
4009 end_pfn = zone_end_pfn(zone);
4010 start_pfn = roundup(start_pfn, pageblock_nr_pages);
4011 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
4015 * Reserve blocks are generally in place to help high-order atomic
4016 * allocations that are short-lived. A min_free_kbytes value that
4017 * would result in more than 2 reserve blocks for atomic allocations
4018 * is assumed to be in place to help anti-fragmentation for the
4019 * future allocation of hugepages at runtime.
4021 reserve = min(2, reserve);
4022 old_reserve = zone->nr_migrate_reserve_block;
4024 /* When memory hot-add, we almost always need to do nothing */
4025 if (reserve == old_reserve)
4027 zone->nr_migrate_reserve_block = reserve;
4029 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
4030 if (!pfn_valid(pfn))
4032 page = pfn_to_page(pfn);
4034 /* Watch out for overlapping nodes */
4035 if (page_to_nid(page) != zone_to_nid(zone))
4038 block_migratetype = get_pageblock_migratetype(page);
4040 /* Only test what is necessary when the reserves are not met */
4043 * Blocks with reserved pages will never free, skip
4046 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
4047 if (pageblock_is_reserved(pfn, block_end_pfn))
4050 /* If this block is reserved, account for it */
4051 if (block_migratetype == MIGRATE_RESERVE) {
4056 /* Suitable for reserving if this block is movable */
4057 if (block_migratetype == MIGRATE_MOVABLE) {
4058 set_pageblock_migratetype(page,
4060 move_freepages_block(zone, page,
4065 } else if (!old_reserve) {
4067 * At boot time we don't need to scan the whole zone
4068 * for turning off MIGRATE_RESERVE.
4074 * If the reserve is met and this is a previous reserved block,
4077 if (block_migratetype == MIGRATE_RESERVE) {
4078 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4079 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4085 * Initially all pages are reserved - free ones are freed
4086 * up by free_all_bootmem() once the early boot process is
4087 * done. Non-atomic initialization, single-pass.
4089 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4090 unsigned long start_pfn, enum memmap_context context)
4093 unsigned long end_pfn = start_pfn + size;
4097 if (highest_memmap_pfn < end_pfn - 1)
4098 highest_memmap_pfn = end_pfn - 1;
4100 z = &NODE_DATA(nid)->node_zones[zone];
4101 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4103 * There can be holes in boot-time mem_map[]s
4104 * handed to this function. They do not
4105 * exist on hotplugged memory.
4107 if (context == MEMMAP_EARLY) {
4108 if (!early_pfn_valid(pfn))
4110 if (!early_pfn_in_nid(pfn, nid))
4113 page = pfn_to_page(pfn);
4114 set_page_links(page, zone, nid, pfn);
4115 mminit_verify_page_links(page, zone, nid, pfn);
4116 init_page_count(page);
4117 page_mapcount_reset(page);
4118 page_cpupid_reset_last(page);
4119 SetPageReserved(page);
4121 * Mark the block movable so that blocks are reserved for
4122 * movable at startup. This will force kernel allocations
4123 * to reserve their blocks rather than leaking throughout
4124 * the address space during boot when many long-lived
4125 * kernel allocations are made. Later some blocks near
4126 * the start are marked MIGRATE_RESERVE by
4127 * setup_zone_migrate_reserve()
4129 * bitmap is created for zone's valid pfn range. but memmap
4130 * can be created for invalid pages (for alignment)
4131 * check here not to call set_pageblock_migratetype() against
4134 if ((z->zone_start_pfn <= pfn)
4135 && (pfn < zone_end_pfn(z))
4136 && !(pfn & (pageblock_nr_pages - 1)))
4137 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4139 INIT_LIST_HEAD(&page->lru);
4140 #ifdef WANT_PAGE_VIRTUAL
4141 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4142 if (!is_highmem_idx(zone))
4143 set_page_address(page, __va(pfn << PAGE_SHIFT));
4148 static void __meminit zone_init_free_lists(struct zone *zone)
4150 unsigned int order, t;
4151 for_each_migratetype_order(order, t) {
4152 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4153 zone->free_area[order].nr_free = 0;
4157 #ifndef __HAVE_ARCH_MEMMAP_INIT
4158 #define memmap_init(size, nid, zone, start_pfn) \
4159 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4162 static int zone_batchsize(struct zone *zone)
4168 * The per-cpu-pages pools are set to around 1000th of the
4169 * size of the zone. But no more than 1/2 of a meg.
4171 * OK, so we don't know how big the cache is. So guess.
4173 batch = zone->managed_pages / 1024;
4174 if (batch * PAGE_SIZE > 512 * 1024)
4175 batch = (512 * 1024) / PAGE_SIZE;
4176 batch /= 4; /* We effectively *= 4 below */
4181 * Clamp the batch to a 2^n - 1 value. Having a power
4182 * of 2 value was found to be more likely to have
4183 * suboptimal cache aliasing properties in some cases.
4185 * For example if 2 tasks are alternately allocating
4186 * batches of pages, one task can end up with a lot
4187 * of pages of one half of the possible page colors
4188 * and the other with pages of the other colors.
4190 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4195 /* The deferral and batching of frees should be suppressed under NOMMU
4198 * The problem is that NOMMU needs to be able to allocate large chunks
4199 * of contiguous memory as there's no hardware page translation to
4200 * assemble apparent contiguous memory from discontiguous pages.
4202 * Queueing large contiguous runs of pages for batching, however,
4203 * causes the pages to actually be freed in smaller chunks. As there
4204 * can be a significant delay between the individual batches being
4205 * recycled, this leads to the once large chunks of space being
4206 * fragmented and becoming unavailable for high-order allocations.
4213 * pcp->high and pcp->batch values are related and dependent on one another:
4214 * ->batch must never be higher then ->high.
4215 * The following function updates them in a safe manner without read side
4218 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4219 * those fields changing asynchronously (acording the the above rule).
4221 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4222 * outside of boot time (or some other assurance that no concurrent updaters
4225 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4226 unsigned long batch)
4228 /* start with a fail safe value for batch */
4232 /* Update high, then batch, in order */
4239 /* a companion to pageset_set_high() */
4240 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4242 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4245 static void pageset_init(struct per_cpu_pageset *p)
4247 struct per_cpu_pages *pcp;
4250 memset(p, 0, sizeof(*p));
4254 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4255 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4258 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4261 pageset_set_batch(p, batch);
4265 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4266 * to the value high for the pageset p.
4268 static void pageset_set_high(struct per_cpu_pageset *p,
4271 unsigned long batch = max(1UL, high / 4);
4272 if ((high / 4) > (PAGE_SHIFT * 8))
4273 batch = PAGE_SHIFT * 8;
4275 pageset_update(&p->pcp, high, batch);
4278 static void pageset_set_high_and_batch(struct zone *zone,
4279 struct per_cpu_pageset *pcp)
4281 if (percpu_pagelist_fraction)
4282 pageset_set_high(pcp,
4283 (zone->managed_pages /
4284 percpu_pagelist_fraction));
4286 pageset_set_batch(pcp, zone_batchsize(zone));
4289 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4291 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4294 pageset_set_high_and_batch(zone, pcp);
4297 static void __meminit setup_zone_pageset(struct zone *zone)
4300 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4301 for_each_possible_cpu(cpu)
4302 zone_pageset_init(zone, cpu);
4306 * Allocate per cpu pagesets and initialize them.
4307 * Before this call only boot pagesets were available.
4309 void __init setup_per_cpu_pageset(void)
4313 for_each_populated_zone(zone)
4314 setup_zone_pageset(zone);
4317 static noinline __init_refok
4318 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4324 * The per-page waitqueue mechanism uses hashed waitqueues
4327 zone->wait_table_hash_nr_entries =
4328 wait_table_hash_nr_entries(zone_size_pages);
4329 zone->wait_table_bits =
4330 wait_table_bits(zone->wait_table_hash_nr_entries);
4331 alloc_size = zone->wait_table_hash_nr_entries
4332 * sizeof(wait_queue_head_t);
4334 if (!slab_is_available()) {
4335 zone->wait_table = (wait_queue_head_t *)
4336 memblock_virt_alloc_node_nopanic(
4337 alloc_size, zone->zone_pgdat->node_id);
4340 * This case means that a zone whose size was 0 gets new memory
4341 * via memory hot-add.
4342 * But it may be the case that a new node was hot-added. In
4343 * this case vmalloc() will not be able to use this new node's
4344 * memory - this wait_table must be initialized to use this new
4345 * node itself as well.
4346 * To use this new node's memory, further consideration will be
4349 zone->wait_table = vmalloc(alloc_size);
4351 if (!zone->wait_table)
4354 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4355 init_waitqueue_head(zone->wait_table + i);
4360 static __meminit void zone_pcp_init(struct zone *zone)
4363 * per cpu subsystem is not up at this point. The following code
4364 * relies on the ability of the linker to provide the
4365 * offset of a (static) per cpu variable into the per cpu area.
4367 zone->pageset = &boot_pageset;
4369 if (populated_zone(zone))
4370 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4371 zone->name, zone->present_pages,
4372 zone_batchsize(zone));
4375 int __meminit init_currently_empty_zone(struct zone *zone,
4376 unsigned long zone_start_pfn,
4378 enum memmap_context context)
4380 struct pglist_data *pgdat = zone->zone_pgdat;
4382 ret = zone_wait_table_init(zone, size);
4385 pgdat->nr_zones = zone_idx(zone) + 1;
4387 zone->zone_start_pfn = zone_start_pfn;
4389 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4390 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4392 (unsigned long)zone_idx(zone),
4393 zone_start_pfn, (zone_start_pfn + size));
4395 zone_init_free_lists(zone);
4400 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4401 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4403 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4405 int __meminit __early_pfn_to_nid(unsigned long pfn)
4407 unsigned long start_pfn, end_pfn;
4410 * NOTE: The following SMP-unsafe globals are only used early in boot
4411 * when the kernel is running single-threaded.
4413 static unsigned long __meminitdata last_start_pfn, last_end_pfn;
4414 static int __meminitdata last_nid;
4416 if (last_start_pfn <= pfn && pfn < last_end_pfn)
4419 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4421 last_start_pfn = start_pfn;
4422 last_end_pfn = end_pfn;
4428 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4430 int __meminit early_pfn_to_nid(unsigned long pfn)
4434 nid = __early_pfn_to_nid(pfn);
4437 /* just returns 0 */
4441 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4442 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4446 nid = __early_pfn_to_nid(pfn);
4447 if (nid >= 0 && nid != node)
4454 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4455 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4456 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4458 * If an architecture guarantees that all ranges registered contain no holes
4459 * and may be freed, this this function may be used instead of calling
4460 * memblock_free_early_nid() manually.
4462 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4464 unsigned long start_pfn, end_pfn;
4467 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4468 start_pfn = min(start_pfn, max_low_pfn);
4469 end_pfn = min(end_pfn, max_low_pfn);
4471 if (start_pfn < end_pfn)
4472 memblock_free_early_nid(PFN_PHYS(start_pfn),
4473 (end_pfn - start_pfn) << PAGE_SHIFT,
4479 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4480 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4482 * If an architecture guarantees that all ranges registered contain no holes and may
4483 * be freed, this function may be used instead of calling memory_present() manually.
4485 void __init sparse_memory_present_with_active_regions(int nid)
4487 unsigned long start_pfn, end_pfn;
4490 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4491 memory_present(this_nid, start_pfn, end_pfn);
4495 * get_pfn_range_for_nid - Return the start and end page frames for a node
4496 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4497 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4498 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4500 * It returns the start and end page frame of a node based on information
4501 * provided by memblock_set_node(). If called for a node
4502 * with no available memory, a warning is printed and the start and end
4505 void __meminit get_pfn_range_for_nid(unsigned int nid,
4506 unsigned long *start_pfn, unsigned long *end_pfn)
4508 unsigned long this_start_pfn, this_end_pfn;
4514 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
4515 *start_pfn = min(*start_pfn, this_start_pfn);
4516 *end_pfn = max(*end_pfn, this_end_pfn);
4519 if (*start_pfn == -1UL)
4524 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4525 * assumption is made that zones within a node are ordered in monotonic
4526 * increasing memory addresses so that the "highest" populated zone is used
4528 static void __init find_usable_zone_for_movable(void)
4531 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4532 if (zone_index == ZONE_MOVABLE)
4535 if (arch_zone_highest_possible_pfn[zone_index] >
4536 arch_zone_lowest_possible_pfn[zone_index])
4540 VM_BUG_ON(zone_index == -1);
4541 movable_zone = zone_index;
4545 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4546 * because it is sized independent of architecture. Unlike the other zones,
4547 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4548 * in each node depending on the size of each node and how evenly kernelcore
4549 * is distributed. This helper function adjusts the zone ranges
4550 * provided by the architecture for a given node by using the end of the
4551 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4552 * zones within a node are in order of monotonic increases memory addresses
4554 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4555 unsigned long zone_type,
4556 unsigned long node_start_pfn,
4557 unsigned long node_end_pfn,
4558 unsigned long *zone_start_pfn,
4559 unsigned long *zone_end_pfn)
4561 /* Only adjust if ZONE_MOVABLE is on this node */
4562 if (zone_movable_pfn[nid]) {
4563 /* Size ZONE_MOVABLE */
4564 if (zone_type == ZONE_MOVABLE) {
4565 *zone_start_pfn = zone_movable_pfn[nid];
4566 *zone_end_pfn = min(node_end_pfn,
4567 arch_zone_highest_possible_pfn[movable_zone]);
4569 /* Adjust for ZONE_MOVABLE starting within this range */
4570 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4571 *zone_end_pfn > zone_movable_pfn[nid]) {
4572 *zone_end_pfn = zone_movable_pfn[nid];
4574 /* Check if this whole range is within ZONE_MOVABLE */
4575 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4576 *zone_start_pfn = *zone_end_pfn;
4581 * Return the number of pages a zone spans in a node, including holes
4582 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4584 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4585 unsigned long zone_type,
4586 unsigned long node_start_pfn,
4587 unsigned long node_end_pfn,
4588 unsigned long *ignored)
4590 unsigned long zone_start_pfn, zone_end_pfn;
4592 /* Get the start and end of the zone */
4593 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4594 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4595 adjust_zone_range_for_zone_movable(nid, zone_type,
4596 node_start_pfn, node_end_pfn,
4597 &zone_start_pfn, &zone_end_pfn);
4599 /* Check that this node has pages within the zone's required range */
4600 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4603 /* Move the zone boundaries inside the node if necessary */
4604 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4605 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4607 /* Return the spanned pages */
4608 return zone_end_pfn - zone_start_pfn;
4612 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4613 * then all holes in the requested range will be accounted for.
4615 unsigned long __meminit __absent_pages_in_range(int nid,
4616 unsigned long range_start_pfn,
4617 unsigned long range_end_pfn)
4619 unsigned long nr_absent = range_end_pfn - range_start_pfn;
4620 unsigned long start_pfn, end_pfn;
4623 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4624 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4625 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4626 nr_absent -= end_pfn - start_pfn;
4632 * absent_pages_in_range - Return number of page frames in holes within a range
4633 * @start_pfn: The start PFN to start searching for holes
4634 * @end_pfn: The end PFN to stop searching for holes
4636 * It returns the number of pages frames in memory holes within a range.
4638 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4639 unsigned long end_pfn)
4641 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4644 /* Return the number of page frames in holes in a zone on a node */
4645 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4646 unsigned long zone_type,
4647 unsigned long node_start_pfn,
4648 unsigned long node_end_pfn,
4649 unsigned long *ignored)
4651 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4652 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4653 unsigned long zone_start_pfn, zone_end_pfn;
4655 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4656 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4658 adjust_zone_range_for_zone_movable(nid, zone_type,
4659 node_start_pfn, node_end_pfn,
4660 &zone_start_pfn, &zone_end_pfn);
4661 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4664 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4665 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4666 unsigned long zone_type,
4667 unsigned long node_start_pfn,
4668 unsigned long node_end_pfn,
4669 unsigned long *zones_size)
4671 return zones_size[zone_type];
4674 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4675 unsigned long zone_type,
4676 unsigned long node_start_pfn,
4677 unsigned long node_end_pfn,
4678 unsigned long *zholes_size)
4683 return zholes_size[zone_type];
4686 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4688 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4689 unsigned long node_start_pfn,
4690 unsigned long node_end_pfn,
4691 unsigned long *zones_size,
4692 unsigned long *zholes_size)
4694 unsigned long realtotalpages, totalpages = 0;
4697 for (i = 0; i < MAX_NR_ZONES; i++)
4698 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4702 pgdat->node_spanned_pages = totalpages;
4704 realtotalpages = totalpages;
4705 for (i = 0; i < MAX_NR_ZONES; i++)
4707 zone_absent_pages_in_node(pgdat->node_id, i,
4708 node_start_pfn, node_end_pfn,
4710 pgdat->node_present_pages = realtotalpages;
4711 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4715 #ifndef CONFIG_SPARSEMEM
4717 * Calculate the size of the zone->blockflags rounded to an unsigned long
4718 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4719 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4720 * round what is now in bits to nearest long in bits, then return it in
4723 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4725 unsigned long usemapsize;
4727 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4728 usemapsize = roundup(zonesize, pageblock_nr_pages);
4729 usemapsize = usemapsize >> pageblock_order;
4730 usemapsize *= NR_PAGEBLOCK_BITS;
4731 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4733 return usemapsize / 8;
4736 static void __init setup_usemap(struct pglist_data *pgdat,
4738 unsigned long zone_start_pfn,
4739 unsigned long zonesize)
4741 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4742 zone->pageblock_flags = NULL;
4744 zone->pageblock_flags =
4745 memblock_virt_alloc_node_nopanic(usemapsize,
4749 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4750 unsigned long zone_start_pfn, unsigned long zonesize) {}
4751 #endif /* CONFIG_SPARSEMEM */
4753 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4755 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4756 void __paginginit set_pageblock_order(void)
4760 /* Check that pageblock_nr_pages has not already been setup */
4761 if (pageblock_order)
4764 if (HPAGE_SHIFT > PAGE_SHIFT)
4765 order = HUGETLB_PAGE_ORDER;
4767 order = MAX_ORDER - 1;
4770 * Assume the largest contiguous order of interest is a huge page.
4771 * This value may be variable depending on boot parameters on IA64 and
4774 pageblock_order = order;
4776 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4779 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4780 * is unused as pageblock_order is set at compile-time. See
4781 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4784 void __paginginit set_pageblock_order(void)
4788 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4790 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
4791 unsigned long present_pages)
4793 unsigned long pages = spanned_pages;
4796 * Provide a more accurate estimation if there are holes within
4797 * the zone and SPARSEMEM is in use. If there are holes within the
4798 * zone, each populated memory region may cost us one or two extra
4799 * memmap pages due to alignment because memmap pages for each
4800 * populated regions may not naturally algined on page boundary.
4801 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4803 if (spanned_pages > present_pages + (present_pages >> 4) &&
4804 IS_ENABLED(CONFIG_SPARSEMEM))
4805 pages = present_pages;
4807 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
4811 * Set up the zone data structures:
4812 * - mark all pages reserved
4813 * - mark all memory queues empty
4814 * - clear the memory bitmaps
4816 * NOTE: pgdat should get zeroed by caller.
4818 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4819 unsigned long node_start_pfn, unsigned long node_end_pfn,
4820 unsigned long *zones_size, unsigned long *zholes_size)
4823 int nid = pgdat->node_id;
4824 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4827 pgdat_resize_init(pgdat);
4828 #ifdef CONFIG_NUMA_BALANCING
4829 spin_lock_init(&pgdat->numabalancing_migrate_lock);
4830 pgdat->numabalancing_migrate_nr_pages = 0;
4831 pgdat->numabalancing_migrate_next_window = jiffies;
4833 init_waitqueue_head(&pgdat->kswapd_wait);
4834 init_waitqueue_head(&pgdat->pfmemalloc_wait);
4835 pgdat_page_cgroup_init(pgdat);
4837 for (j = 0; j < MAX_NR_ZONES; j++) {
4838 struct zone *zone = pgdat->node_zones + j;
4839 unsigned long size, realsize, freesize, memmap_pages;
4841 size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
4842 node_end_pfn, zones_size);
4843 realsize = freesize = size - zone_absent_pages_in_node(nid, j,
4849 * Adjust freesize so that it accounts for how much memory
4850 * is used by this zone for memmap. This affects the watermark
4851 * and per-cpu initialisations
4853 memmap_pages = calc_memmap_size(size, realsize);
4854 if (freesize >= memmap_pages) {
4855 freesize -= memmap_pages;
4858 " %s zone: %lu pages used for memmap\n",
4859 zone_names[j], memmap_pages);
4862 " %s zone: %lu pages exceeds freesize %lu\n",
4863 zone_names[j], memmap_pages, freesize);
4865 /* Account for reserved pages */
4866 if (j == 0 && freesize > dma_reserve) {
4867 freesize -= dma_reserve;
4868 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4869 zone_names[0], dma_reserve);
4872 if (!is_highmem_idx(j))
4873 nr_kernel_pages += freesize;
4874 /* Charge for highmem memmap if there are enough kernel pages */
4875 else if (nr_kernel_pages > memmap_pages * 2)
4876 nr_kernel_pages -= memmap_pages;
4877 nr_all_pages += freesize;
4879 zone->spanned_pages = size;
4880 zone->present_pages = realsize;
4882 * Set an approximate value for lowmem here, it will be adjusted
4883 * when the bootmem allocator frees pages into the buddy system.
4884 * And all highmem pages will be managed by the buddy system.
4886 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
4889 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4891 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4893 zone->name = zone_names[j];
4894 spin_lock_init(&zone->lock);
4895 spin_lock_init(&zone->lru_lock);
4896 zone_seqlock_init(zone);
4897 zone->zone_pgdat = pgdat;
4898 zone_pcp_init(zone);
4900 /* For bootup, initialized properly in watermark setup */
4901 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
4903 lruvec_init(&zone->lruvec);
4907 set_pageblock_order();
4908 setup_usemap(pgdat, zone, zone_start_pfn, size);
4909 ret = init_currently_empty_zone(zone, zone_start_pfn,
4910 size, MEMMAP_EARLY);
4912 memmap_init(size, nid, j, zone_start_pfn);
4913 zone_start_pfn += size;
4917 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4919 /* Skip empty nodes */
4920 if (!pgdat->node_spanned_pages)
4923 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4924 /* ia64 gets its own node_mem_map, before this, without bootmem */
4925 if (!pgdat->node_mem_map) {
4926 unsigned long size, start, end;
4930 * The zone's endpoints aren't required to be MAX_ORDER
4931 * aligned but the node_mem_map endpoints must be in order
4932 * for the buddy allocator to function correctly.
4934 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4935 end = pgdat_end_pfn(pgdat);
4936 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4937 size = (end - start) * sizeof(struct page);
4938 map = alloc_remap(pgdat->node_id, size);
4940 map = memblock_virt_alloc_node_nopanic(size,
4942 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4944 #ifndef CONFIG_NEED_MULTIPLE_NODES
4946 * With no DISCONTIG, the global mem_map is just set as node 0's
4948 if (pgdat == NODE_DATA(0)) {
4949 mem_map = NODE_DATA(0)->node_mem_map;
4950 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4951 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4952 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4953 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4956 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4959 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4960 unsigned long node_start_pfn, unsigned long *zholes_size)
4962 pg_data_t *pgdat = NODE_DATA(nid);
4963 unsigned long start_pfn = 0;
4964 unsigned long end_pfn = 0;
4966 /* pg_data_t should be reset to zero when it's allocated */
4967 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4969 pgdat->node_id = nid;
4970 pgdat->node_start_pfn = node_start_pfn;
4971 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4972 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
4973 printk(KERN_INFO "Initmem setup node %d [mem %#010Lx-%#010Lx]\n", nid,
4974 (u64) start_pfn << PAGE_SHIFT, (u64) (end_pfn << PAGE_SHIFT) - 1);
4976 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
4977 zones_size, zholes_size);
4979 alloc_node_mem_map(pgdat);
4980 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4981 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4982 nid, (unsigned long)pgdat,
4983 (unsigned long)pgdat->node_mem_map);
4986 free_area_init_core(pgdat, start_pfn, end_pfn,
4987 zones_size, zholes_size);
4990 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4992 #if MAX_NUMNODES > 1
4994 * Figure out the number of possible node ids.
4996 void __init setup_nr_node_ids(void)
4999 unsigned int highest = 0;
5001 for_each_node_mask(node, node_possible_map)
5003 nr_node_ids = highest + 1;
5008 * node_map_pfn_alignment - determine the maximum internode alignment
5010 * This function should be called after node map is populated and sorted.
5011 * It calculates the maximum power of two alignment which can distinguish
5014 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5015 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5016 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5017 * shifted, 1GiB is enough and this function will indicate so.
5019 * This is used to test whether pfn -> nid mapping of the chosen memory
5020 * model has fine enough granularity to avoid incorrect mapping for the
5021 * populated node map.
5023 * Returns the determined alignment in pfn's. 0 if there is no alignment
5024 * requirement (single node).
5026 unsigned long __init node_map_pfn_alignment(void)
5028 unsigned long accl_mask = 0, last_end = 0;
5029 unsigned long start, end, mask;
5033 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5034 if (!start || last_nid < 0 || last_nid == nid) {
5041 * Start with a mask granular enough to pin-point to the
5042 * start pfn and tick off bits one-by-one until it becomes
5043 * too coarse to separate the current node from the last.
5045 mask = ~((1 << __ffs(start)) - 1);
5046 while (mask && last_end <= (start & (mask << 1)))
5049 /* accumulate all internode masks */
5053 /* convert mask to number of pages */
5054 return ~accl_mask + 1;
5057 /* Find the lowest pfn for a node */
5058 static unsigned long __init find_min_pfn_for_node(int nid)
5060 unsigned long min_pfn = ULONG_MAX;
5061 unsigned long start_pfn;
5064 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5065 min_pfn = min(min_pfn, start_pfn);
5067 if (min_pfn == ULONG_MAX) {
5069 "Could not find start_pfn for node %d\n", nid);
5077 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5079 * It returns the minimum PFN based on information provided via
5080 * memblock_set_node().
5082 unsigned long __init find_min_pfn_with_active_regions(void)
5084 return find_min_pfn_for_node(MAX_NUMNODES);
5088 * early_calculate_totalpages()
5089 * Sum pages in active regions for movable zone.
5090 * Populate N_MEMORY for calculating usable_nodes.
5092 static unsigned long __init early_calculate_totalpages(void)
5094 unsigned long totalpages = 0;
5095 unsigned long start_pfn, end_pfn;
5098 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5099 unsigned long pages = end_pfn - start_pfn;
5101 totalpages += pages;
5103 node_set_state(nid, N_MEMORY);
5109 * Find the PFN the Movable zone begins in each node. Kernel memory
5110 * is spread evenly between nodes as long as the nodes have enough
5111 * memory. When they don't, some nodes will have more kernelcore than
5114 static void __init find_zone_movable_pfns_for_nodes(void)
5117 unsigned long usable_startpfn;
5118 unsigned long kernelcore_node, kernelcore_remaining;
5119 /* save the state before borrow the nodemask */
5120 nodemask_t saved_node_state = node_states[N_MEMORY];
5121 unsigned long totalpages = early_calculate_totalpages();
5122 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5123 struct memblock_region *r;
5125 /* Need to find movable_zone earlier when movable_node is specified. */
5126 find_usable_zone_for_movable();
5129 * If movable_node is specified, ignore kernelcore and movablecore
5132 if (movable_node_is_enabled()) {
5133 for_each_memblock(memory, r) {
5134 if (!memblock_is_hotpluggable(r))
5139 usable_startpfn = PFN_DOWN(r->base);
5140 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5141 min(usable_startpfn, zone_movable_pfn[nid]) :
5149 * If movablecore=nn[KMG] was specified, calculate what size of
5150 * kernelcore that corresponds so that memory usable for
5151 * any allocation type is evenly spread. If both kernelcore
5152 * and movablecore are specified, then the value of kernelcore
5153 * will be used for required_kernelcore if it's greater than
5154 * what movablecore would have allowed.
5156 if (required_movablecore) {
5157 unsigned long corepages;
5160 * Round-up so that ZONE_MOVABLE is at least as large as what
5161 * was requested by the user
5163 required_movablecore =
5164 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5165 corepages = totalpages - required_movablecore;
5167 required_kernelcore = max(required_kernelcore, corepages);
5170 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5171 if (!required_kernelcore)
5174 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5175 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5178 /* Spread kernelcore memory as evenly as possible throughout nodes */
5179 kernelcore_node = required_kernelcore / usable_nodes;
5180 for_each_node_state(nid, N_MEMORY) {
5181 unsigned long start_pfn, end_pfn;
5184 * Recalculate kernelcore_node if the division per node
5185 * now exceeds what is necessary to satisfy the requested
5186 * amount of memory for the kernel
5188 if (required_kernelcore < kernelcore_node)
5189 kernelcore_node = required_kernelcore / usable_nodes;
5192 * As the map is walked, we track how much memory is usable
5193 * by the kernel using kernelcore_remaining. When it is
5194 * 0, the rest of the node is usable by ZONE_MOVABLE
5196 kernelcore_remaining = kernelcore_node;
5198 /* Go through each range of PFNs within this node */
5199 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5200 unsigned long size_pages;
5202 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5203 if (start_pfn >= end_pfn)
5206 /* Account for what is only usable for kernelcore */
5207 if (start_pfn < usable_startpfn) {
5208 unsigned long kernel_pages;
5209 kernel_pages = min(end_pfn, usable_startpfn)
5212 kernelcore_remaining -= min(kernel_pages,
5213 kernelcore_remaining);
5214 required_kernelcore -= min(kernel_pages,
5215 required_kernelcore);
5217 /* Continue if range is now fully accounted */
5218 if (end_pfn <= usable_startpfn) {
5221 * Push zone_movable_pfn to the end so
5222 * that if we have to rebalance
5223 * kernelcore across nodes, we will
5224 * not double account here
5226 zone_movable_pfn[nid] = end_pfn;
5229 start_pfn = usable_startpfn;
5233 * The usable PFN range for ZONE_MOVABLE is from
5234 * start_pfn->end_pfn. Calculate size_pages as the
5235 * number of pages used as kernelcore
5237 size_pages = end_pfn - start_pfn;
5238 if (size_pages > kernelcore_remaining)
5239 size_pages = kernelcore_remaining;
5240 zone_movable_pfn[nid] = start_pfn + size_pages;
5243 * Some kernelcore has been met, update counts and
5244 * break if the kernelcore for this node has been
5247 required_kernelcore -= min(required_kernelcore,
5249 kernelcore_remaining -= size_pages;
5250 if (!kernelcore_remaining)
5256 * If there is still required_kernelcore, we do another pass with one
5257 * less node in the count. This will push zone_movable_pfn[nid] further
5258 * along on the nodes that still have memory until kernelcore is
5262 if (usable_nodes && required_kernelcore > usable_nodes)
5266 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5267 for (nid = 0; nid < MAX_NUMNODES; nid++)
5268 zone_movable_pfn[nid] =
5269 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5272 /* restore the node_state */
5273 node_states[N_MEMORY] = saved_node_state;
5276 /* Any regular or high memory on that node ? */
5277 static void check_for_memory(pg_data_t *pgdat, int nid)
5279 enum zone_type zone_type;
5281 if (N_MEMORY == N_NORMAL_MEMORY)
5284 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5285 struct zone *zone = &pgdat->node_zones[zone_type];
5286 if (populated_zone(zone)) {
5287 node_set_state(nid, N_HIGH_MEMORY);
5288 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5289 zone_type <= ZONE_NORMAL)
5290 node_set_state(nid, N_NORMAL_MEMORY);
5297 * free_area_init_nodes - Initialise all pg_data_t and zone data
5298 * @max_zone_pfn: an array of max PFNs for each zone
5300 * This will call free_area_init_node() for each active node in the system.
5301 * Using the page ranges provided by memblock_set_node(), the size of each
5302 * zone in each node and their holes is calculated. If the maximum PFN
5303 * between two adjacent zones match, it is assumed that the zone is empty.
5304 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5305 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5306 * starts where the previous one ended. For example, ZONE_DMA32 starts
5307 * at arch_max_dma_pfn.
5309 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5311 unsigned long start_pfn, end_pfn;
5314 /* Record where the zone boundaries are */
5315 memset(arch_zone_lowest_possible_pfn, 0,
5316 sizeof(arch_zone_lowest_possible_pfn));
5317 memset(arch_zone_highest_possible_pfn, 0,
5318 sizeof(arch_zone_highest_possible_pfn));
5319 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5320 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5321 for (i = 1; i < MAX_NR_ZONES; i++) {
5322 if (i == ZONE_MOVABLE)
5324 arch_zone_lowest_possible_pfn[i] =
5325 arch_zone_highest_possible_pfn[i-1];
5326 arch_zone_highest_possible_pfn[i] =
5327 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5329 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5330 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5332 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5333 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5334 find_zone_movable_pfns_for_nodes();
5336 /* Print out the zone ranges */
5337 printk("Zone ranges:\n");
5338 for (i = 0; i < MAX_NR_ZONES; i++) {
5339 if (i == ZONE_MOVABLE)
5341 printk(KERN_CONT " %-8s ", zone_names[i]);
5342 if (arch_zone_lowest_possible_pfn[i] ==
5343 arch_zone_highest_possible_pfn[i])
5344 printk(KERN_CONT "empty\n");
5346 printk(KERN_CONT "[mem %0#10lx-%0#10lx]\n",
5347 arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT,
5348 (arch_zone_highest_possible_pfn[i]
5349 << PAGE_SHIFT) - 1);
5352 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5353 printk("Movable zone start for each node\n");
5354 for (i = 0; i < MAX_NUMNODES; i++) {
5355 if (zone_movable_pfn[i])
5356 printk(" Node %d: %#010lx\n", i,
5357 zone_movable_pfn[i] << PAGE_SHIFT);
5360 /* Print out the early node map */
5361 printk("Early memory node ranges\n");
5362 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5363 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid,
5364 start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
5366 /* Initialise every node */
5367 mminit_verify_pageflags_layout();
5368 setup_nr_node_ids();
5369 for_each_online_node(nid) {
5370 pg_data_t *pgdat = NODE_DATA(nid);
5371 free_area_init_node(nid, NULL,
5372 find_min_pfn_for_node(nid), NULL);
5374 /* Any memory on that node */
5375 if (pgdat->node_present_pages)
5376 node_set_state(nid, N_MEMORY);
5377 check_for_memory(pgdat, nid);
5381 static int __init cmdline_parse_core(char *p, unsigned long *core)
5383 unsigned long long coremem;
5387 coremem = memparse(p, &p);
5388 *core = coremem >> PAGE_SHIFT;
5390 /* Paranoid check that UL is enough for the coremem value */
5391 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5397 * kernelcore=size sets the amount of memory for use for allocations that
5398 * cannot be reclaimed or migrated.
5400 static int __init cmdline_parse_kernelcore(char *p)
5402 return cmdline_parse_core(p, &required_kernelcore);
5406 * movablecore=size sets the amount of memory for use for allocations that
5407 * can be reclaimed or migrated.
5409 static int __init cmdline_parse_movablecore(char *p)
5411 return cmdline_parse_core(p, &required_movablecore);
5414 early_param("kernelcore", cmdline_parse_kernelcore);
5415 early_param("movablecore", cmdline_parse_movablecore);
5417 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5419 void adjust_managed_page_count(struct page *page, long count)
5421 spin_lock(&managed_page_count_lock);
5422 page_zone(page)->managed_pages += count;
5423 totalram_pages += count;
5424 #ifdef CONFIG_HIGHMEM
5425 if (PageHighMem(page))
5426 totalhigh_pages += count;
5428 spin_unlock(&managed_page_count_lock);
5430 EXPORT_SYMBOL(adjust_managed_page_count);
5432 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5435 unsigned long pages = 0;
5437 start = (void *)PAGE_ALIGN((unsigned long)start);
5438 end = (void *)((unsigned long)end & PAGE_MASK);
5439 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5440 if ((unsigned int)poison <= 0xFF)
5441 memset(pos, poison, PAGE_SIZE);
5442 free_reserved_page(virt_to_page(pos));
5446 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5447 s, pages << (PAGE_SHIFT - 10), start, end);
5451 EXPORT_SYMBOL(free_reserved_area);
5453 #ifdef CONFIG_HIGHMEM
5454 void free_highmem_page(struct page *page)
5456 __free_reserved_page(page);
5458 page_zone(page)->managed_pages++;
5464 void __init mem_init_print_info(const char *str)
5466 unsigned long physpages, codesize, datasize, rosize, bss_size;
5467 unsigned long init_code_size, init_data_size;
5469 physpages = get_num_physpages();
5470 codesize = _etext - _stext;
5471 datasize = _edata - _sdata;
5472 rosize = __end_rodata - __start_rodata;
5473 bss_size = __bss_stop - __bss_start;
5474 init_data_size = __init_end - __init_begin;
5475 init_code_size = _einittext - _sinittext;
5478 * Detect special cases and adjust section sizes accordingly:
5479 * 1) .init.* may be embedded into .data sections
5480 * 2) .init.text.* may be out of [__init_begin, __init_end],
5481 * please refer to arch/tile/kernel/vmlinux.lds.S.
5482 * 3) .rodata.* may be embedded into .text or .data sections.
5484 #define adj_init_size(start, end, size, pos, adj) \
5486 if (start <= pos && pos < end && size > adj) \
5490 adj_init_size(__init_begin, __init_end, init_data_size,
5491 _sinittext, init_code_size);
5492 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
5493 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
5494 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
5495 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
5497 #undef adj_init_size
5499 printk("Memory: %luK/%luK available "
5500 "(%luK kernel code, %luK rwdata, %luK rodata, "
5501 "%luK init, %luK bss, %luK reserved"
5502 #ifdef CONFIG_HIGHMEM
5506 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
5507 codesize >> 10, datasize >> 10, rosize >> 10,
5508 (init_data_size + init_code_size) >> 10, bss_size >> 10,
5509 (physpages - totalram_pages) << (PAGE_SHIFT-10),
5510 #ifdef CONFIG_HIGHMEM
5511 totalhigh_pages << (PAGE_SHIFT-10),
5513 str ? ", " : "", str ? str : "");
5517 * set_dma_reserve - set the specified number of pages reserved in the first zone
5518 * @new_dma_reserve: The number of pages to mark reserved
5520 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5521 * In the DMA zone, a significant percentage may be consumed by kernel image
5522 * and other unfreeable allocations which can skew the watermarks badly. This
5523 * function may optionally be used to account for unfreeable pages in the
5524 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5525 * smaller per-cpu batchsize.
5527 void __init set_dma_reserve(unsigned long new_dma_reserve)
5529 dma_reserve = new_dma_reserve;
5532 void __init free_area_init(unsigned long *zones_size)
5534 free_area_init_node(0, zones_size,
5535 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5538 static int page_alloc_cpu_notify(struct notifier_block *self,
5539 unsigned long action, void *hcpu)
5541 int cpu = (unsigned long)hcpu;
5543 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5544 lru_add_drain_cpu(cpu);
5548 * Spill the event counters of the dead processor
5549 * into the current processors event counters.
5550 * This artificially elevates the count of the current
5553 vm_events_fold_cpu(cpu);
5556 * Zero the differential counters of the dead processor
5557 * so that the vm statistics are consistent.
5559 * This is only okay since the processor is dead and cannot
5560 * race with what we are doing.
5562 cpu_vm_stats_fold(cpu);
5567 void __init page_alloc_init(void)
5569 hotcpu_notifier(page_alloc_cpu_notify, 0);
5573 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5574 * or min_free_kbytes changes.
5576 static void calculate_totalreserve_pages(void)
5578 struct pglist_data *pgdat;
5579 unsigned long reserve_pages = 0;
5580 enum zone_type i, j;
5582 for_each_online_pgdat(pgdat) {
5583 for (i = 0; i < MAX_NR_ZONES; i++) {
5584 struct zone *zone = pgdat->node_zones + i;
5587 /* Find valid and maximum lowmem_reserve in the zone */
5588 for (j = i; j < MAX_NR_ZONES; j++) {
5589 if (zone->lowmem_reserve[j] > max)
5590 max = zone->lowmem_reserve[j];
5593 /* we treat the high watermark as reserved pages. */
5594 max += high_wmark_pages(zone);
5596 if (max > zone->managed_pages)
5597 max = zone->managed_pages;
5598 reserve_pages += max;
5600 * Lowmem reserves are not available to
5601 * GFP_HIGHUSER page cache allocations and
5602 * kswapd tries to balance zones to their high
5603 * watermark. As a result, neither should be
5604 * regarded as dirtyable memory, to prevent a
5605 * situation where reclaim has to clean pages
5606 * in order to balance the zones.
5608 zone->dirty_balance_reserve = max;
5611 dirty_balance_reserve = reserve_pages;
5612 totalreserve_pages = reserve_pages;
5616 * setup_per_zone_lowmem_reserve - called whenever
5617 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5618 * has a correct pages reserved value, so an adequate number of
5619 * pages are left in the zone after a successful __alloc_pages().
5621 static void setup_per_zone_lowmem_reserve(void)
5623 struct pglist_data *pgdat;
5624 enum zone_type j, idx;
5626 for_each_online_pgdat(pgdat) {
5627 for (j = 0; j < MAX_NR_ZONES; j++) {
5628 struct zone *zone = pgdat->node_zones + j;
5629 unsigned long managed_pages = zone->managed_pages;
5631 zone->lowmem_reserve[j] = 0;
5635 struct zone *lower_zone;
5639 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5640 sysctl_lowmem_reserve_ratio[idx] = 1;
5642 lower_zone = pgdat->node_zones + idx;
5643 lower_zone->lowmem_reserve[j] = managed_pages /
5644 sysctl_lowmem_reserve_ratio[idx];
5645 managed_pages += lower_zone->managed_pages;
5650 /* update totalreserve_pages */
5651 calculate_totalreserve_pages();
5654 static void __setup_per_zone_wmarks(void)
5656 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5657 unsigned long lowmem_pages = 0;
5659 unsigned long flags;
5661 /* Calculate total number of !ZONE_HIGHMEM pages */
5662 for_each_zone(zone) {
5663 if (!is_highmem(zone))
5664 lowmem_pages += zone->managed_pages;
5667 for_each_zone(zone) {
5670 spin_lock_irqsave(&zone->lock, flags);
5671 tmp = (u64)pages_min * zone->managed_pages;
5672 do_div(tmp, lowmem_pages);
5673 if (is_highmem(zone)) {
5675 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5676 * need highmem pages, so cap pages_min to a small
5679 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5680 * deltas controls asynch page reclaim, and so should
5681 * not be capped for highmem.
5683 unsigned long min_pages;
5685 min_pages = zone->managed_pages / 1024;
5686 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
5687 zone->watermark[WMARK_MIN] = min_pages;
5690 * If it's a lowmem zone, reserve a number of pages
5691 * proportionate to the zone's size.
5693 zone->watermark[WMARK_MIN] = tmp;
5696 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5697 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5699 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
5700 high_wmark_pages(zone) - low_wmark_pages(zone) -
5701 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
5703 setup_zone_migrate_reserve(zone);
5704 spin_unlock_irqrestore(&zone->lock, flags);
5707 /* update totalreserve_pages */
5708 calculate_totalreserve_pages();
5712 * setup_per_zone_wmarks - called when min_free_kbytes changes
5713 * or when memory is hot-{added|removed}
5715 * Ensures that the watermark[min,low,high] values for each zone are set
5716 * correctly with respect to min_free_kbytes.
5718 void setup_per_zone_wmarks(void)
5720 mutex_lock(&zonelists_mutex);
5721 __setup_per_zone_wmarks();
5722 mutex_unlock(&zonelists_mutex);
5726 * The inactive anon list should be small enough that the VM never has to
5727 * do too much work, but large enough that each inactive page has a chance
5728 * to be referenced again before it is swapped out.
5730 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5731 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5732 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5733 * the anonymous pages are kept on the inactive list.
5736 * memory ratio inactive anon
5737 * -------------------------------------
5746 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5748 unsigned int gb, ratio;
5750 /* Zone size in gigabytes */
5751 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
5753 ratio = int_sqrt(10 * gb);
5757 zone->inactive_ratio = ratio;
5760 static void __meminit setup_per_zone_inactive_ratio(void)
5765 calculate_zone_inactive_ratio(zone);
5769 * Initialise min_free_kbytes.
5771 * For small machines we want it small (128k min). For large machines
5772 * we want it large (64MB max). But it is not linear, because network
5773 * bandwidth does not increase linearly with machine size. We use
5775 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5776 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5792 int __meminit init_per_zone_wmark_min(void)
5794 unsigned long lowmem_kbytes;
5795 int new_min_free_kbytes;
5797 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5798 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5800 if (new_min_free_kbytes > user_min_free_kbytes) {
5801 min_free_kbytes = new_min_free_kbytes;
5802 if (min_free_kbytes < 128)
5803 min_free_kbytes = 128;
5804 if (min_free_kbytes > 65536)
5805 min_free_kbytes = 65536;
5807 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5808 new_min_free_kbytes, user_min_free_kbytes);
5810 setup_per_zone_wmarks();
5811 refresh_zone_stat_thresholds();
5812 setup_per_zone_lowmem_reserve();
5813 setup_per_zone_inactive_ratio();
5816 module_init(init_per_zone_wmark_min)
5819 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5820 * that we can call two helper functions whenever min_free_kbytes
5823 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
5824 void __user *buffer, size_t *length, loff_t *ppos)
5828 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5833 user_min_free_kbytes = min_free_kbytes;
5834 setup_per_zone_wmarks();
5840 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
5841 void __user *buffer, size_t *length, loff_t *ppos)
5846 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5851 zone->min_unmapped_pages = (zone->managed_pages *
5852 sysctl_min_unmapped_ratio) / 100;
5856 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
5857 void __user *buffer, size_t *length, loff_t *ppos)
5862 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5867 zone->min_slab_pages = (zone->managed_pages *
5868 sysctl_min_slab_ratio) / 100;
5874 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5875 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5876 * whenever sysctl_lowmem_reserve_ratio changes.
5878 * The reserve ratio obviously has absolutely no relation with the
5879 * minimum watermarks. The lowmem reserve ratio can only make sense
5880 * if in function of the boot time zone sizes.
5882 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
5883 void __user *buffer, size_t *length, loff_t *ppos)
5885 proc_dointvec_minmax(table, write, buffer, length, ppos);
5886 setup_per_zone_lowmem_reserve();
5891 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5892 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5893 * pagelist can have before it gets flushed back to buddy allocator.
5895 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
5896 void __user *buffer, size_t *length, loff_t *ppos)
5899 int old_percpu_pagelist_fraction;
5902 mutex_lock(&pcp_batch_high_lock);
5903 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
5905 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5906 if (!write || ret < 0)
5909 /* Sanity checking to avoid pcp imbalance */
5910 if (percpu_pagelist_fraction &&
5911 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
5912 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
5918 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
5921 for_each_populated_zone(zone) {
5924 for_each_possible_cpu(cpu)
5925 pageset_set_high_and_batch(zone,
5926 per_cpu_ptr(zone->pageset, cpu));
5929 mutex_unlock(&pcp_batch_high_lock);
5933 int hashdist = HASHDIST_DEFAULT;
5936 static int __init set_hashdist(char *str)
5940 hashdist = simple_strtoul(str, &str, 0);
5943 __setup("hashdist=", set_hashdist);
5947 * allocate a large system hash table from bootmem
5948 * - it is assumed that the hash table must contain an exact power-of-2
5949 * quantity of entries
5950 * - limit is the number of hash buckets, not the total allocation size
5952 void *__init alloc_large_system_hash(const char *tablename,
5953 unsigned long bucketsize,
5954 unsigned long numentries,
5957 unsigned int *_hash_shift,
5958 unsigned int *_hash_mask,
5959 unsigned long low_limit,
5960 unsigned long high_limit)
5962 unsigned long long max = high_limit;
5963 unsigned long log2qty, size;
5966 /* allow the kernel cmdline to have a say */
5968 /* round applicable memory size up to nearest megabyte */
5969 numentries = nr_kernel_pages;
5971 /* It isn't necessary when PAGE_SIZE >= 1MB */
5972 if (PAGE_SHIFT < 20)
5973 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
5975 /* limit to 1 bucket per 2^scale bytes of low memory */
5976 if (scale > PAGE_SHIFT)
5977 numentries >>= (scale - PAGE_SHIFT);
5979 numentries <<= (PAGE_SHIFT - scale);
5981 /* Make sure we've got at least a 0-order allocation.. */
5982 if (unlikely(flags & HASH_SMALL)) {
5983 /* Makes no sense without HASH_EARLY */
5984 WARN_ON(!(flags & HASH_EARLY));
5985 if (!(numentries >> *_hash_shift)) {
5986 numentries = 1UL << *_hash_shift;
5987 BUG_ON(!numentries);
5989 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5990 numentries = PAGE_SIZE / bucketsize;
5992 numentries = roundup_pow_of_two(numentries);
5994 /* limit allocation size to 1/16 total memory by default */
5996 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5997 do_div(max, bucketsize);
5999 max = min(max, 0x80000000ULL);
6001 if (numentries < low_limit)
6002 numentries = low_limit;
6003 if (numentries > max)
6006 log2qty = ilog2(numentries);
6009 size = bucketsize << log2qty;
6010 if (flags & HASH_EARLY)
6011 table = memblock_virt_alloc_nopanic(size, 0);
6013 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6016 * If bucketsize is not a power-of-two, we may free
6017 * some pages at the end of hash table which
6018 * alloc_pages_exact() automatically does
6020 if (get_order(size) < MAX_ORDER) {
6021 table = alloc_pages_exact(size, GFP_ATOMIC);
6022 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6025 } while (!table && size > PAGE_SIZE && --log2qty);
6028 panic("Failed to allocate %s hash table\n", tablename);
6030 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6033 ilog2(size) - PAGE_SHIFT,
6037 *_hash_shift = log2qty;
6039 *_hash_mask = (1 << log2qty) - 1;
6044 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6045 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6048 #ifdef CONFIG_SPARSEMEM
6049 return __pfn_to_section(pfn)->pageblock_flags;
6051 return zone->pageblock_flags;
6052 #endif /* CONFIG_SPARSEMEM */
6055 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6057 #ifdef CONFIG_SPARSEMEM
6058 pfn &= (PAGES_PER_SECTION-1);
6059 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6061 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6062 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6063 #endif /* CONFIG_SPARSEMEM */
6067 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6068 * @page: The page within the block of interest
6069 * @pfn: The target page frame number
6070 * @end_bitidx: The last bit of interest to retrieve
6071 * @mask: mask of bits that the caller is interested in
6073 * Return: pageblock_bits flags
6075 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6076 unsigned long end_bitidx,
6080 unsigned long *bitmap;
6081 unsigned long bitidx, word_bitidx;
6084 zone = page_zone(page);
6085 bitmap = get_pageblock_bitmap(zone, pfn);
6086 bitidx = pfn_to_bitidx(zone, pfn);
6087 word_bitidx = bitidx / BITS_PER_LONG;
6088 bitidx &= (BITS_PER_LONG-1);
6090 word = bitmap[word_bitidx];
6091 bitidx += end_bitidx;
6092 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6096 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6097 * @page: The page within the block of interest
6098 * @flags: The flags to set
6099 * @pfn: The target page frame number
6100 * @end_bitidx: The last bit of interest
6101 * @mask: mask of bits that the caller is interested in
6103 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6105 unsigned long end_bitidx,
6109 unsigned long *bitmap;
6110 unsigned long bitidx, word_bitidx;
6111 unsigned long old_word, word;
6113 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6115 zone = page_zone(page);
6116 bitmap = get_pageblock_bitmap(zone, pfn);
6117 bitidx = pfn_to_bitidx(zone, pfn);
6118 word_bitidx = bitidx / BITS_PER_LONG;
6119 bitidx &= (BITS_PER_LONG-1);
6121 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6123 bitidx += end_bitidx;
6124 mask <<= (BITS_PER_LONG - bitidx - 1);
6125 flags <<= (BITS_PER_LONG - bitidx - 1);
6127 word = ACCESS_ONCE(bitmap[word_bitidx]);
6129 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6130 if (word == old_word)
6137 * This function checks whether pageblock includes unmovable pages or not.
6138 * If @count is not zero, it is okay to include less @count unmovable pages
6140 * PageLRU check without isolation or lru_lock could race so that
6141 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6142 * expect this function should be exact.
6144 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6145 bool skip_hwpoisoned_pages)
6147 unsigned long pfn, iter, found;
6151 * For avoiding noise data, lru_add_drain_all() should be called
6152 * If ZONE_MOVABLE, the zone never contains unmovable pages
6154 if (zone_idx(zone) == ZONE_MOVABLE)
6156 mt = get_pageblock_migratetype(page);
6157 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6160 pfn = page_to_pfn(page);
6161 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6162 unsigned long check = pfn + iter;
6164 if (!pfn_valid_within(check))
6167 page = pfn_to_page(check);
6170 * Hugepages are not in LRU lists, but they're movable.
6171 * We need not scan over tail pages bacause we don't
6172 * handle each tail page individually in migration.
6174 if (PageHuge(page)) {
6175 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6180 * We can't use page_count without pin a page
6181 * because another CPU can free compound page.
6182 * This check already skips compound tails of THP
6183 * because their page->_count is zero at all time.
6185 if (!atomic_read(&page->_count)) {
6186 if (PageBuddy(page))
6187 iter += (1 << page_order(page)) - 1;
6192 * The HWPoisoned page may be not in buddy system, and
6193 * page_count() is not 0.
6195 if (skip_hwpoisoned_pages && PageHWPoison(page))
6201 * If there are RECLAIMABLE pages, we need to check it.
6202 * But now, memory offline itself doesn't call shrink_slab()
6203 * and it still to be fixed.
6206 * If the page is not RAM, page_count()should be 0.
6207 * we don't need more check. This is an _used_ not-movable page.
6209 * The problematic thing here is PG_reserved pages. PG_reserved
6210 * is set to both of a memory hole page and a _used_ kernel
6219 bool is_pageblock_removable_nolock(struct page *page)
6225 * We have to be careful here because we are iterating over memory
6226 * sections which are not zone aware so we might end up outside of
6227 * the zone but still within the section.
6228 * We have to take care about the node as well. If the node is offline
6229 * its NODE_DATA will be NULL - see page_zone.
6231 if (!node_online(page_to_nid(page)))
6234 zone = page_zone(page);
6235 pfn = page_to_pfn(page);
6236 if (!zone_spans_pfn(zone, pfn))
6239 return !has_unmovable_pages(zone, page, 0, true);
6244 static unsigned long pfn_max_align_down(unsigned long pfn)
6246 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6247 pageblock_nr_pages) - 1);
6250 static unsigned long pfn_max_align_up(unsigned long pfn)
6252 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6253 pageblock_nr_pages));
6256 /* [start, end) must belong to a single zone. */
6257 static int __alloc_contig_migrate_range(struct compact_control *cc,
6258 unsigned long start, unsigned long end)
6260 /* This function is based on compact_zone() from compaction.c. */
6261 unsigned long nr_reclaimed;
6262 unsigned long pfn = start;
6263 unsigned int tries = 0;
6268 while (pfn < end || !list_empty(&cc->migratepages)) {
6269 if (fatal_signal_pending(current)) {
6274 if (list_empty(&cc->migratepages)) {
6275 cc->nr_migratepages = 0;
6276 pfn = isolate_migratepages_range(cc, pfn, end);
6282 } else if (++tries == 5) {
6283 ret = ret < 0 ? ret : -EBUSY;
6287 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6289 cc->nr_migratepages -= nr_reclaimed;
6291 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6292 NULL, 0, cc->mode, MR_CMA);
6295 putback_movable_pages(&cc->migratepages);
6302 * alloc_contig_range() -- tries to allocate given range of pages
6303 * @start: start PFN to allocate
6304 * @end: one-past-the-last PFN to allocate
6305 * @migratetype: migratetype of the underlaying pageblocks (either
6306 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6307 * in range must have the same migratetype and it must
6308 * be either of the two.
6310 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6311 * aligned, however it's the caller's responsibility to guarantee that
6312 * we are the only thread that changes migrate type of pageblocks the
6315 * The PFN range must belong to a single zone.
6317 * Returns zero on success or negative error code. On success all
6318 * pages which PFN is in [start, end) are allocated for the caller and
6319 * need to be freed with free_contig_range().
6321 int alloc_contig_range(unsigned long start, unsigned long end,
6322 unsigned migratetype)
6324 unsigned long outer_start, outer_end;
6327 struct compact_control cc = {
6328 .nr_migratepages = 0,
6330 .zone = page_zone(pfn_to_page(start)),
6331 .mode = MIGRATE_SYNC,
6332 .ignore_skip_hint = true,
6334 INIT_LIST_HEAD(&cc.migratepages);
6337 * What we do here is we mark all pageblocks in range as
6338 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6339 * have different sizes, and due to the way page allocator
6340 * work, we align the range to biggest of the two pages so
6341 * that page allocator won't try to merge buddies from
6342 * different pageblocks and change MIGRATE_ISOLATE to some
6343 * other migration type.
6345 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6346 * migrate the pages from an unaligned range (ie. pages that
6347 * we are interested in). This will put all the pages in
6348 * range back to page allocator as MIGRATE_ISOLATE.
6350 * When this is done, we take the pages in range from page
6351 * allocator removing them from the buddy system. This way
6352 * page allocator will never consider using them.
6354 * This lets us mark the pageblocks back as
6355 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6356 * aligned range but not in the unaligned, original range are
6357 * put back to page allocator so that buddy can use them.
6360 ret = start_isolate_page_range(pfn_max_align_down(start),
6361 pfn_max_align_up(end), migratetype,
6366 ret = __alloc_contig_migrate_range(&cc, start, end);
6371 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6372 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6373 * more, all pages in [start, end) are free in page allocator.
6374 * What we are going to do is to allocate all pages from
6375 * [start, end) (that is remove them from page allocator).
6377 * The only problem is that pages at the beginning and at the
6378 * end of interesting range may be not aligned with pages that
6379 * page allocator holds, ie. they can be part of higher order
6380 * pages. Because of this, we reserve the bigger range and
6381 * once this is done free the pages we are not interested in.
6383 * We don't have to hold zone->lock here because the pages are
6384 * isolated thus they won't get removed from buddy.
6387 lru_add_drain_all();
6391 outer_start = start;
6392 while (!PageBuddy(pfn_to_page(outer_start))) {
6393 if (++order >= MAX_ORDER) {
6397 outer_start &= ~0UL << order;
6400 /* Make sure the range is really isolated. */
6401 if (test_pages_isolated(outer_start, end, false)) {
6402 pr_info("%s: [%lx, %lx) PFNs busy\n",
6403 __func__, outer_start, end);
6408 /* Grab isolated pages from freelists. */
6409 outer_end = isolate_freepages_range(&cc, outer_start, end);
6415 /* Free head and tail (if any) */
6416 if (start != outer_start)
6417 free_contig_range(outer_start, start - outer_start);
6418 if (end != outer_end)
6419 free_contig_range(end, outer_end - end);
6422 undo_isolate_page_range(pfn_max_align_down(start),
6423 pfn_max_align_up(end), migratetype);
6427 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6429 unsigned int count = 0;
6431 for (; nr_pages--; pfn++) {
6432 struct page *page = pfn_to_page(pfn);
6434 count += page_count(page) != 1;
6437 WARN(count != 0, "%d pages are still in use!\n", count);
6441 #ifdef CONFIG_MEMORY_HOTPLUG
6443 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6444 * page high values need to be recalulated.
6446 void __meminit zone_pcp_update(struct zone *zone)
6449 mutex_lock(&pcp_batch_high_lock);
6450 for_each_possible_cpu(cpu)
6451 pageset_set_high_and_batch(zone,
6452 per_cpu_ptr(zone->pageset, cpu));
6453 mutex_unlock(&pcp_batch_high_lock);
6457 void zone_pcp_reset(struct zone *zone)
6459 unsigned long flags;
6461 struct per_cpu_pageset *pset;
6463 /* avoid races with drain_pages() */
6464 local_irq_save(flags);
6465 if (zone->pageset != &boot_pageset) {
6466 for_each_online_cpu(cpu) {
6467 pset = per_cpu_ptr(zone->pageset, cpu);
6468 drain_zonestat(zone, pset);
6470 free_percpu(zone->pageset);
6471 zone->pageset = &boot_pageset;
6473 local_irq_restore(flags);
6476 #ifdef CONFIG_MEMORY_HOTREMOVE
6478 * All pages in the range must be isolated before calling this.
6481 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6485 unsigned int order, i;
6487 unsigned long flags;
6488 /* find the first valid pfn */
6489 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6494 zone = page_zone(pfn_to_page(pfn));
6495 spin_lock_irqsave(&zone->lock, flags);
6497 while (pfn < end_pfn) {
6498 if (!pfn_valid(pfn)) {
6502 page = pfn_to_page(pfn);
6504 * The HWPoisoned page may be not in buddy system, and
6505 * page_count() is not 0.
6507 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
6509 SetPageReserved(page);
6513 BUG_ON(page_count(page));
6514 BUG_ON(!PageBuddy(page));
6515 order = page_order(page);
6516 #ifdef CONFIG_DEBUG_VM
6517 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6518 pfn, 1 << order, end_pfn);
6520 list_del(&page->lru);
6521 rmv_page_order(page);
6522 zone->free_area[order].nr_free--;
6523 for (i = 0; i < (1 << order); i++)
6524 SetPageReserved((page+i));
6525 pfn += (1 << order);
6527 spin_unlock_irqrestore(&zone->lock, flags);
6531 #ifdef CONFIG_MEMORY_FAILURE
6532 bool is_free_buddy_page(struct page *page)
6534 struct zone *zone = page_zone(page);
6535 unsigned long pfn = page_to_pfn(page);
6536 unsigned long flags;
6539 spin_lock_irqsave(&zone->lock, flags);
6540 for (order = 0; order < MAX_ORDER; order++) {
6541 struct page *page_head = page - (pfn & ((1 << order) - 1));
6543 if (PageBuddy(page_head) && page_order(page_head) >= order)
6546 spin_unlock_irqrestore(&zone->lock, flags);
6548 return order < MAX_ORDER;