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/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page-debug-flags.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
65 #include <asm/sections.h>
66 #include <asm/tlbflush.h>
67 #include <asm/div64.h>
70 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
71 static DEFINE_MUTEX(pcp_batch_high_lock);
73 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
74 DEFINE_PER_CPU(int, numa_node);
75 EXPORT_PER_CPU_SYMBOL(numa_node);
78 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
80 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
81 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
82 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
83 * defined in <linux/topology.h>.
85 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
86 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
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 %lu outside zone [ %lu - %lu ]\n",
265 pfn, start_pfn, start_pfn + sp);
270 static int page_is_consistent(struct zone *zone, struct page *page)
272 if (!pfn_valid_within(page_to_pfn(page)))
274 if (zone != page_zone(page))
280 * Temporary debugging check for pages not lying within a given zone.
282 static int bad_range(struct zone *zone, struct page *page)
284 if (page_outside_zone_boundaries(zone, page))
286 if (!page_is_consistent(zone, page))
292 static inline int bad_range(struct zone *zone, struct page *page)
298 static void bad_page(struct page *page, char *reason, unsigned long bad_flags)
300 static unsigned long resume;
301 static unsigned long nr_shown;
302 static unsigned long nr_unshown;
304 /* Don't complain about poisoned pages */
305 if (PageHWPoison(page)) {
306 page_mapcount_reset(page); /* remove PageBuddy */
311 * Allow a burst of 60 reports, then keep quiet for that minute;
312 * or allow a steady drip of one report per second.
314 if (nr_shown == 60) {
315 if (time_before(jiffies, resume)) {
321 "BUG: Bad page state: %lu messages suppressed\n",
328 resume = jiffies + 60 * HZ;
330 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
331 current->comm, page_to_pfn(page));
332 dump_page_badflags(page, reason, bad_flags);
337 /* Leave bad fields for debug, except PageBuddy could make trouble */
338 page_mapcount_reset(page); /* remove PageBuddy */
339 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
343 * Higher-order pages are called "compound pages". They are structured thusly:
345 * The first PAGE_SIZE page is called the "head page".
347 * The remaining PAGE_SIZE pages are called "tail pages".
349 * All pages have PG_compound set. All tail pages have their ->first_page
350 * pointing at the head page.
352 * The first tail page's ->lru.next holds the address of the compound page's
353 * put_page() function. Its ->lru.prev holds the order of allocation.
354 * This usage means that zero-order pages may not be compound.
357 static void free_compound_page(struct page *page)
359 __free_pages_ok(page, compound_order(page));
362 void prep_compound_page(struct page *page, unsigned long order)
365 int nr_pages = 1 << order;
367 set_compound_page_dtor(page, free_compound_page);
368 set_compound_order(page, order);
370 for (i = 1; i < nr_pages; i++) {
371 struct page *p = page + i;
372 set_page_count(p, 0);
373 p->first_page = page;
374 /* Make sure p->first_page is always valid for PageTail() */
380 /* update __split_huge_page_refcount if you change this function */
381 static int destroy_compound_page(struct page *page, unsigned long order)
384 int nr_pages = 1 << order;
387 if (unlikely(compound_order(page) != order)) {
388 bad_page(page, "wrong compound order", 0);
392 __ClearPageHead(page);
394 for (i = 1; i < nr_pages; i++) {
395 struct page *p = page + i;
397 if (unlikely(!PageTail(p))) {
398 bad_page(page, "PageTail not set", 0);
400 } else if (unlikely(p->first_page != page)) {
401 bad_page(page, "first_page not consistent", 0);
410 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
415 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
416 * and __GFP_HIGHMEM from hard or soft interrupt context.
418 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
419 for (i = 0; i < (1 << order); i++)
420 clear_highpage(page + i);
423 #ifdef CONFIG_DEBUG_PAGEALLOC
424 unsigned int _debug_guardpage_minorder;
426 static int __init debug_guardpage_minorder_setup(char *buf)
430 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
431 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
434 _debug_guardpage_minorder = res;
435 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
438 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
440 static inline void set_page_guard_flag(struct page *page)
442 __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
445 static inline void clear_page_guard_flag(struct page *page)
447 __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
450 static inline void set_page_guard_flag(struct page *page) { }
451 static inline void clear_page_guard_flag(struct page *page) { }
454 static inline void set_page_order(struct page *page, int order)
456 set_page_private(page, order);
457 __SetPageBuddy(page);
460 static inline void rmv_page_order(struct page *page)
462 __ClearPageBuddy(page);
463 set_page_private(page, 0);
467 * Locate the struct page for both the matching buddy in our
468 * pair (buddy1) and the combined O(n+1) page they form (page).
470 * 1) Any buddy B1 will have an order O twin B2 which satisfies
471 * the following equation:
473 * For example, if the starting buddy (buddy2) is #8 its order
475 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
477 * 2) Any buddy B will have an order O+1 parent P which
478 * satisfies the following equation:
481 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
483 static inline unsigned long
484 __find_buddy_index(unsigned long page_idx, unsigned int order)
486 return page_idx ^ (1 << order);
490 * This function checks whether a page is free && is the buddy
491 * we can do coalesce a page and its buddy if
492 * (a) the buddy is not in a hole &&
493 * (b) the buddy is in the buddy system &&
494 * (c) a page and its buddy have the same order &&
495 * (d) a page and its buddy are in the same zone.
497 * For recording whether a page is in the buddy system, we set ->_mapcount
498 * PAGE_BUDDY_MAPCOUNT_VALUE.
499 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
500 * serialized by zone->lock.
502 * For recording page's order, we use page_private(page).
504 static inline int page_is_buddy(struct page *page, struct page *buddy,
507 if (!pfn_valid_within(page_to_pfn(buddy)))
510 if (page_zone_id(page) != page_zone_id(buddy))
513 if (page_is_guard(buddy) && page_order(buddy) == order) {
514 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
518 if (PageBuddy(buddy) && page_order(buddy) == order) {
519 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
526 * Freeing function for a buddy system allocator.
528 * The concept of a buddy system is to maintain direct-mapped table
529 * (containing bit values) for memory blocks of various "orders".
530 * The bottom level table contains the map for the smallest allocatable
531 * units of memory (here, pages), and each level above it describes
532 * pairs of units from the levels below, hence, "buddies".
533 * At a high level, all that happens here is marking the table entry
534 * at the bottom level available, and propagating the changes upward
535 * as necessary, plus some accounting needed to play nicely with other
536 * parts of the VM system.
537 * At each level, we keep a list of pages, which are heads of continuous
538 * free pages of length of (1 << order) and marked with _mapcount
539 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
541 * So when we are allocating or freeing one, we can derive the state of the
542 * other. That is, if we allocate a small block, and both were
543 * free, the remainder of the region must be split into blocks.
544 * If a block is freed, and its buddy is also free, then this
545 * triggers coalescing into a block of larger size.
550 static inline void __free_one_page(struct page *page,
551 struct zone *zone, unsigned int order,
554 unsigned long page_idx;
555 unsigned long combined_idx;
556 unsigned long uninitialized_var(buddy_idx);
559 VM_BUG_ON(!zone_is_initialized(zone));
561 if (unlikely(PageCompound(page)))
562 if (unlikely(destroy_compound_page(page, order)))
565 VM_BUG_ON(migratetype == -1);
567 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
569 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
570 VM_BUG_ON_PAGE(bad_range(zone, page), page);
572 while (order < MAX_ORDER-1) {
573 buddy_idx = __find_buddy_index(page_idx, order);
574 buddy = page + (buddy_idx - page_idx);
575 if (!page_is_buddy(page, buddy, order))
578 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
579 * merge with it and move up one order.
581 if (page_is_guard(buddy)) {
582 clear_page_guard_flag(buddy);
583 set_page_private(page, 0);
584 __mod_zone_freepage_state(zone, 1 << order,
587 list_del(&buddy->lru);
588 zone->free_area[order].nr_free--;
589 rmv_page_order(buddy);
591 combined_idx = buddy_idx & page_idx;
592 page = page + (combined_idx - page_idx);
593 page_idx = combined_idx;
596 set_page_order(page, order);
599 * If this is not the largest possible page, check if the buddy
600 * of the next-highest order is free. If it is, it's possible
601 * that pages are being freed that will coalesce soon. In case,
602 * that is happening, add the free page to the tail of the list
603 * so it's less likely to be used soon and more likely to be merged
604 * as a higher order page
606 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
607 struct page *higher_page, *higher_buddy;
608 combined_idx = buddy_idx & page_idx;
609 higher_page = page + (combined_idx - page_idx);
610 buddy_idx = __find_buddy_index(combined_idx, order + 1);
611 higher_buddy = higher_page + (buddy_idx - combined_idx);
612 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
613 list_add_tail(&page->lru,
614 &zone->free_area[order].free_list[migratetype]);
619 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
621 zone->free_area[order].nr_free++;
624 static inline int free_pages_check(struct page *page)
626 char *bad_reason = NULL;
627 unsigned long bad_flags = 0;
629 if (unlikely(page_mapcount(page)))
630 bad_reason = "nonzero mapcount";
631 if (unlikely(page->mapping != NULL))
632 bad_reason = "non-NULL mapping";
633 if (unlikely(atomic_read(&page->_count) != 0))
634 bad_reason = "nonzero _count";
635 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
636 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
637 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
639 if (unlikely(mem_cgroup_bad_page_check(page)))
640 bad_reason = "cgroup check failed";
641 if (unlikely(bad_reason)) {
642 bad_page(page, bad_reason, bad_flags);
645 page_cpupid_reset_last(page);
646 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
647 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
652 * Frees a number of pages from the PCP lists
653 * Assumes all pages on list are in same zone, and of same order.
654 * count is the number of pages to free.
656 * If the zone was previously in an "all pages pinned" state then look to
657 * see if this freeing clears that state.
659 * And clear the zone's pages_scanned counter, to hold off the "all pages are
660 * pinned" detection logic.
662 static void free_pcppages_bulk(struct zone *zone, int count,
663 struct per_cpu_pages *pcp)
669 spin_lock(&zone->lock);
670 zone->pages_scanned = 0;
674 struct list_head *list;
677 * Remove pages from lists in a round-robin fashion. A
678 * batch_free count is maintained that is incremented when an
679 * empty list is encountered. This is so more pages are freed
680 * off fuller lists instead of spinning excessively around empty
685 if (++migratetype == MIGRATE_PCPTYPES)
687 list = &pcp->lists[migratetype];
688 } while (list_empty(list));
690 /* This is the only non-empty list. Free them all. */
691 if (batch_free == MIGRATE_PCPTYPES)
692 batch_free = to_free;
695 int mt; /* migratetype of the to-be-freed page */
697 page = list_entry(list->prev, struct page, lru);
698 /* must delete as __free_one_page list manipulates */
699 list_del(&page->lru);
700 mt = get_freepage_migratetype(page);
701 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
702 __free_one_page(page, zone, 0, mt);
703 trace_mm_page_pcpu_drain(page, 0, mt);
704 if (likely(!is_migrate_isolate_page(page))) {
705 __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
706 if (is_migrate_cma(mt))
707 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
709 } while (--to_free && --batch_free && !list_empty(list));
711 spin_unlock(&zone->lock);
714 static void free_one_page(struct zone *zone, struct page *page, int order,
717 spin_lock(&zone->lock);
718 zone->pages_scanned = 0;
720 __free_one_page(page, zone, order, migratetype);
721 if (unlikely(!is_migrate_isolate(migratetype)))
722 __mod_zone_freepage_state(zone, 1 << order, migratetype);
723 spin_unlock(&zone->lock);
726 static bool free_pages_prepare(struct page *page, unsigned int order)
731 trace_mm_page_free(page, order);
732 kmemcheck_free_shadow(page, order);
735 page->mapping = NULL;
736 for (i = 0; i < (1 << order); i++)
737 bad += free_pages_check(page + i);
741 if (!PageHighMem(page)) {
742 debug_check_no_locks_freed(page_address(page),
744 debug_check_no_obj_freed(page_address(page),
747 arch_free_page(page, order);
748 kernel_map_pages(page, 1 << order, 0);
753 static void __free_pages_ok(struct page *page, unsigned int order)
758 if (!free_pages_prepare(page, order))
761 local_irq_save(flags);
762 __count_vm_events(PGFREE, 1 << order);
763 migratetype = get_pageblock_migratetype(page);
764 set_freepage_migratetype(page, migratetype);
765 free_one_page(page_zone(page), page, order, migratetype);
766 local_irq_restore(flags);
769 void __init __free_pages_bootmem(struct page *page, unsigned int order)
771 unsigned int nr_pages = 1 << order;
772 struct page *p = page;
776 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
778 __ClearPageReserved(p);
779 set_page_count(p, 0);
781 __ClearPageReserved(p);
782 set_page_count(p, 0);
784 page_zone(page)->managed_pages += nr_pages;
785 set_page_refcounted(page);
786 __free_pages(page, order);
790 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
791 void __init init_cma_reserved_pageblock(struct page *page)
793 unsigned i = pageblock_nr_pages;
794 struct page *p = page;
797 __ClearPageReserved(p);
798 set_page_count(p, 0);
801 set_page_refcounted(page);
802 set_pageblock_migratetype(page, MIGRATE_CMA);
803 __free_pages(page, pageblock_order);
804 adjust_managed_page_count(page, pageblock_nr_pages);
809 * The order of subdivision here is critical for the IO subsystem.
810 * Please do not alter this order without good reasons and regression
811 * testing. Specifically, as large blocks of memory are subdivided,
812 * the order in which smaller blocks are delivered depends on the order
813 * they're subdivided in this function. This is the primary factor
814 * influencing the order in which pages are delivered to the IO
815 * subsystem according to empirical testing, and this is also justified
816 * by considering the behavior of a buddy system containing a single
817 * large block of memory acted on by a series of small allocations.
818 * This behavior is a critical factor in sglist merging's success.
822 static inline void expand(struct zone *zone, struct page *page,
823 int low, int high, struct free_area *area,
826 unsigned long size = 1 << high;
832 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
834 #ifdef CONFIG_DEBUG_PAGEALLOC
835 if (high < debug_guardpage_minorder()) {
837 * Mark as guard pages (or page), that will allow to
838 * merge back to allocator when buddy will be freed.
839 * Corresponding page table entries will not be touched,
840 * pages will stay not present in virtual address space
842 INIT_LIST_HEAD(&page[size].lru);
843 set_page_guard_flag(&page[size]);
844 set_page_private(&page[size], high);
845 /* Guard pages are not available for any usage */
846 __mod_zone_freepage_state(zone, -(1 << high),
851 list_add(&page[size].lru, &area->free_list[migratetype]);
853 set_page_order(&page[size], high);
858 * This page is about to be returned from the page allocator
860 static inline int check_new_page(struct page *page)
862 char *bad_reason = NULL;
863 unsigned long bad_flags = 0;
865 if (unlikely(page_mapcount(page)))
866 bad_reason = "nonzero mapcount";
867 if (unlikely(page->mapping != NULL))
868 bad_reason = "non-NULL mapping";
869 if (unlikely(atomic_read(&page->_count) != 0))
870 bad_reason = "nonzero _count";
871 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
872 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
873 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
875 if (unlikely(mem_cgroup_bad_page_check(page)))
876 bad_reason = "cgroup check failed";
877 if (unlikely(bad_reason)) {
878 bad_page(page, bad_reason, bad_flags);
884 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
888 for (i = 0; i < (1 << order); i++) {
889 struct page *p = page + i;
890 if (unlikely(check_new_page(p)))
894 set_page_private(page, 0);
895 set_page_refcounted(page);
897 arch_alloc_page(page, order);
898 kernel_map_pages(page, 1 << order, 1);
900 if (gfp_flags & __GFP_ZERO)
901 prep_zero_page(page, order, gfp_flags);
903 if (order && (gfp_flags & __GFP_COMP))
904 prep_compound_page(page, order);
910 * Go through the free lists for the given migratetype and remove
911 * the smallest available page from the freelists
914 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
917 unsigned int current_order;
918 struct free_area *area;
921 /* Find a page of the appropriate size in the preferred list */
922 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
923 area = &(zone->free_area[current_order]);
924 if (list_empty(&area->free_list[migratetype]))
927 page = list_entry(area->free_list[migratetype].next,
929 list_del(&page->lru);
930 rmv_page_order(page);
932 expand(zone, page, order, current_order, area, migratetype);
941 * This array describes the order lists are fallen back to when
942 * the free lists for the desirable migrate type are depleted
944 static int fallbacks[MIGRATE_TYPES][4] = {
945 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
946 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
948 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
949 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
951 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
953 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
954 #ifdef CONFIG_MEMORY_ISOLATION
955 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
960 * Move the free pages in a range to the free lists of the requested type.
961 * Note that start_page and end_pages are not aligned on a pageblock
962 * boundary. If alignment is required, use move_freepages_block()
964 int move_freepages(struct zone *zone,
965 struct page *start_page, struct page *end_page,
972 #ifndef CONFIG_HOLES_IN_ZONE
974 * page_zone is not safe to call in this context when
975 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
976 * anyway as we check zone boundaries in move_freepages_block().
977 * Remove at a later date when no bug reports exist related to
978 * grouping pages by mobility
980 BUG_ON(page_zone(start_page) != page_zone(end_page));
983 for (page = start_page; page <= end_page;) {
984 /* Make sure we are not inadvertently changing nodes */
985 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
987 if (!pfn_valid_within(page_to_pfn(page))) {
992 if (!PageBuddy(page)) {
997 order = page_order(page);
998 list_move(&page->lru,
999 &zone->free_area[order].free_list[migratetype]);
1000 set_freepage_migratetype(page, migratetype);
1002 pages_moved += 1 << order;
1008 int move_freepages_block(struct zone *zone, struct page *page,
1011 unsigned long start_pfn, end_pfn;
1012 struct page *start_page, *end_page;
1014 start_pfn = page_to_pfn(page);
1015 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1016 start_page = pfn_to_page(start_pfn);
1017 end_page = start_page + pageblock_nr_pages - 1;
1018 end_pfn = start_pfn + pageblock_nr_pages - 1;
1020 /* Do not cross zone boundaries */
1021 if (!zone_spans_pfn(zone, start_pfn))
1023 if (!zone_spans_pfn(zone, end_pfn))
1026 return move_freepages(zone, start_page, end_page, migratetype);
1029 static void change_pageblock_range(struct page *pageblock_page,
1030 int start_order, int migratetype)
1032 int nr_pageblocks = 1 << (start_order - pageblock_order);
1034 while (nr_pageblocks--) {
1035 set_pageblock_migratetype(pageblock_page, migratetype);
1036 pageblock_page += pageblock_nr_pages;
1041 * If breaking a large block of pages, move all free pages to the preferred
1042 * allocation list. If falling back for a reclaimable kernel allocation, be
1043 * more aggressive about taking ownership of free pages.
1045 * On the other hand, never change migration type of MIGRATE_CMA pageblocks
1046 * nor move CMA pages to different free lists. We don't want unmovable pages
1047 * to be allocated from MIGRATE_CMA areas.
1049 * Returns the new migratetype of the pageblock (or the same old migratetype
1050 * if it was unchanged).
1052 static int try_to_steal_freepages(struct zone *zone, struct page *page,
1053 int start_type, int fallback_type)
1055 int current_order = page_order(page);
1058 * When borrowing from MIGRATE_CMA, we need to release the excess
1059 * buddy pages to CMA itself.
1061 if (is_migrate_cma(fallback_type))
1062 return fallback_type;
1064 /* Take ownership for orders >= pageblock_order */
1065 if (current_order >= pageblock_order) {
1066 change_pageblock_range(page, current_order, start_type);
1070 if (current_order >= pageblock_order / 2 ||
1071 start_type == MIGRATE_RECLAIMABLE ||
1072 page_group_by_mobility_disabled) {
1075 pages = move_freepages_block(zone, page, start_type);
1077 /* Claim the whole block if over half of it is free */
1078 if (pages >= (1 << (pageblock_order-1)) ||
1079 page_group_by_mobility_disabled) {
1081 set_pageblock_migratetype(page, start_type);
1087 return fallback_type;
1090 /* Remove an element from the buddy allocator from the fallback list */
1091 static inline struct page *
1092 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
1094 struct free_area *area;
1097 int migratetype, new_type, i;
1099 /* Find the largest possible block of pages in the other list */
1100 for (current_order = MAX_ORDER-1; current_order >= order;
1103 migratetype = fallbacks[start_migratetype][i];
1105 /* MIGRATE_RESERVE handled later if necessary */
1106 if (migratetype == MIGRATE_RESERVE)
1109 area = &(zone->free_area[current_order]);
1110 if (list_empty(&area->free_list[migratetype]))
1113 page = list_entry(area->free_list[migratetype].next,
1117 new_type = try_to_steal_freepages(zone, page,
1121 /* Remove the page from the freelists */
1122 list_del(&page->lru);
1123 rmv_page_order(page);
1125 expand(zone, page, order, current_order, area,
1128 trace_mm_page_alloc_extfrag(page, order, current_order,
1129 start_migratetype, migratetype, new_type);
1139 * Do the hard work of removing an element from the buddy allocator.
1140 * Call me with the zone->lock already held.
1142 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1148 page = __rmqueue_smallest(zone, order, migratetype);
1150 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1151 page = __rmqueue_fallback(zone, order, migratetype);
1154 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1155 * is used because __rmqueue_smallest is an inline function
1156 * and we want just one call site
1159 migratetype = MIGRATE_RESERVE;
1164 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1169 * Obtain a specified number of elements from the buddy allocator, all under
1170 * a single hold of the lock, for efficiency. Add them to the supplied list.
1171 * Returns the number of new pages which were placed at *list.
1173 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1174 unsigned long count, struct list_head *list,
1175 int migratetype, int cold)
1177 int mt = migratetype, i;
1179 spin_lock(&zone->lock);
1180 for (i = 0; i < count; ++i) {
1181 struct page *page = __rmqueue(zone, order, migratetype);
1182 if (unlikely(page == NULL))
1186 * Split buddy pages returned by expand() are received here
1187 * in physical page order. The page is added to the callers and
1188 * list and the list head then moves forward. From the callers
1189 * perspective, the linked list is ordered by page number in
1190 * some conditions. This is useful for IO devices that can
1191 * merge IO requests if the physical pages are ordered
1194 if (likely(cold == 0))
1195 list_add(&page->lru, list);
1197 list_add_tail(&page->lru, list);
1198 if (IS_ENABLED(CONFIG_CMA)) {
1199 mt = get_pageblock_migratetype(page);
1200 if (!is_migrate_cma(mt) && !is_migrate_isolate(mt))
1203 set_freepage_migratetype(page, mt);
1205 if (is_migrate_cma(mt))
1206 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1209 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1210 spin_unlock(&zone->lock);
1216 * Called from the vmstat counter updater to drain pagesets of this
1217 * currently executing processor on remote nodes after they have
1220 * Note that this function must be called with the thread pinned to
1221 * a single processor.
1223 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1225 unsigned long flags;
1227 unsigned long batch;
1229 local_irq_save(flags);
1230 batch = ACCESS_ONCE(pcp->batch);
1231 if (pcp->count >= batch)
1234 to_drain = pcp->count;
1236 free_pcppages_bulk(zone, to_drain, pcp);
1237 pcp->count -= to_drain;
1239 local_irq_restore(flags);
1244 * Drain pages of the indicated processor.
1246 * The processor must either be the current processor and the
1247 * thread pinned to the current processor or a processor that
1250 static void drain_pages(unsigned int cpu)
1252 unsigned long flags;
1255 for_each_populated_zone(zone) {
1256 struct per_cpu_pageset *pset;
1257 struct per_cpu_pages *pcp;
1259 local_irq_save(flags);
1260 pset = per_cpu_ptr(zone->pageset, cpu);
1264 free_pcppages_bulk(zone, pcp->count, pcp);
1267 local_irq_restore(flags);
1272 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1274 void drain_local_pages(void *arg)
1276 drain_pages(smp_processor_id());
1280 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1282 * Note that this code is protected against sending an IPI to an offline
1283 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1284 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1285 * nothing keeps CPUs from showing up after we populated the cpumask and
1286 * before the call to on_each_cpu_mask().
1288 void drain_all_pages(void)
1291 struct per_cpu_pageset *pcp;
1295 * Allocate in the BSS so we wont require allocation in
1296 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1298 static cpumask_t cpus_with_pcps;
1301 * We don't care about racing with CPU hotplug event
1302 * as offline notification will cause the notified
1303 * cpu to drain that CPU pcps and on_each_cpu_mask
1304 * disables preemption as part of its processing
1306 for_each_online_cpu(cpu) {
1307 bool has_pcps = false;
1308 for_each_populated_zone(zone) {
1309 pcp = per_cpu_ptr(zone->pageset, cpu);
1310 if (pcp->pcp.count) {
1316 cpumask_set_cpu(cpu, &cpus_with_pcps);
1318 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1320 on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
1323 #ifdef CONFIG_HIBERNATION
1325 void mark_free_pages(struct zone *zone)
1327 unsigned long pfn, max_zone_pfn;
1328 unsigned long flags;
1330 struct list_head *curr;
1332 if (zone_is_empty(zone))
1335 spin_lock_irqsave(&zone->lock, flags);
1337 max_zone_pfn = zone_end_pfn(zone);
1338 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1339 if (pfn_valid(pfn)) {
1340 struct page *page = pfn_to_page(pfn);
1342 if (!swsusp_page_is_forbidden(page))
1343 swsusp_unset_page_free(page);
1346 for_each_migratetype_order(order, t) {
1347 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1350 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1351 for (i = 0; i < (1UL << order); i++)
1352 swsusp_set_page_free(pfn_to_page(pfn + i));
1355 spin_unlock_irqrestore(&zone->lock, flags);
1357 #endif /* CONFIG_PM */
1360 * Free a 0-order page
1361 * cold == 1 ? free a cold page : free a hot page
1363 void free_hot_cold_page(struct page *page, int cold)
1365 struct zone *zone = page_zone(page);
1366 struct per_cpu_pages *pcp;
1367 unsigned long flags;
1370 if (!free_pages_prepare(page, 0))
1373 migratetype = get_pageblock_migratetype(page);
1374 set_freepage_migratetype(page, migratetype);
1375 local_irq_save(flags);
1376 __count_vm_event(PGFREE);
1379 * We only track unmovable, reclaimable and movable on pcp lists.
1380 * Free ISOLATE pages back to the allocator because they are being
1381 * offlined but treat RESERVE as movable pages so we can get those
1382 * areas back if necessary. Otherwise, we may have to free
1383 * excessively into the page allocator
1385 if (migratetype >= MIGRATE_PCPTYPES) {
1386 if (unlikely(is_migrate_isolate(migratetype))) {
1387 free_one_page(zone, page, 0, migratetype);
1390 migratetype = MIGRATE_MOVABLE;
1393 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1395 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1397 list_add(&page->lru, &pcp->lists[migratetype]);
1399 if (pcp->count >= pcp->high) {
1400 unsigned long batch = ACCESS_ONCE(pcp->batch);
1401 free_pcppages_bulk(zone, batch, pcp);
1402 pcp->count -= batch;
1406 local_irq_restore(flags);
1410 * Free a list of 0-order pages
1412 void free_hot_cold_page_list(struct list_head *list, int cold)
1414 struct page *page, *next;
1416 list_for_each_entry_safe(page, next, list, lru) {
1417 trace_mm_page_free_batched(page, cold);
1418 free_hot_cold_page(page, cold);
1423 * split_page takes a non-compound higher-order page, and splits it into
1424 * n (1<<order) sub-pages: page[0..n]
1425 * Each sub-page must be freed individually.
1427 * Note: this is probably too low level an operation for use in drivers.
1428 * Please consult with lkml before using this in your driver.
1430 void split_page(struct page *page, unsigned int order)
1434 VM_BUG_ON_PAGE(PageCompound(page), page);
1435 VM_BUG_ON_PAGE(!page_count(page), page);
1437 #ifdef CONFIG_KMEMCHECK
1439 * Split shadow pages too, because free(page[0]) would
1440 * otherwise free the whole shadow.
1442 if (kmemcheck_page_is_tracked(page))
1443 split_page(virt_to_page(page[0].shadow), order);
1446 for (i = 1; i < (1 << order); i++)
1447 set_page_refcounted(page + i);
1449 EXPORT_SYMBOL_GPL(split_page);
1451 static int __isolate_free_page(struct page *page, unsigned int order)
1453 unsigned long watermark;
1457 BUG_ON(!PageBuddy(page));
1459 zone = page_zone(page);
1460 mt = get_pageblock_migratetype(page);
1462 if (!is_migrate_isolate(mt)) {
1463 /* Obey watermarks as if the page was being allocated */
1464 watermark = low_wmark_pages(zone) + (1 << order);
1465 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1468 __mod_zone_freepage_state(zone, -(1UL << order), mt);
1471 /* Remove page from free list */
1472 list_del(&page->lru);
1473 zone->free_area[order].nr_free--;
1474 rmv_page_order(page);
1476 /* Set the pageblock if the isolated page is at least a pageblock */
1477 if (order >= pageblock_order - 1) {
1478 struct page *endpage = page + (1 << order) - 1;
1479 for (; page < endpage; page += pageblock_nr_pages) {
1480 int mt = get_pageblock_migratetype(page);
1481 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
1482 set_pageblock_migratetype(page,
1487 return 1UL << order;
1491 * Similar to split_page except the page is already free. As this is only
1492 * being used for migration, the migratetype of the block also changes.
1493 * As this is called with interrupts disabled, the caller is responsible
1494 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1497 * Note: this is probably too low level an operation for use in drivers.
1498 * Please consult with lkml before using this in your driver.
1500 int split_free_page(struct page *page)
1505 order = page_order(page);
1507 nr_pages = __isolate_free_page(page, order);
1511 /* Split into individual pages */
1512 set_page_refcounted(page);
1513 split_page(page, order);
1518 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1519 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1523 struct page *buffered_rmqueue(struct zone *preferred_zone,
1524 struct zone *zone, int order, gfp_t gfp_flags,
1527 unsigned long flags;
1529 int cold = !!(gfp_flags & __GFP_COLD);
1532 if (likely(order == 0)) {
1533 struct per_cpu_pages *pcp;
1534 struct list_head *list;
1536 local_irq_save(flags);
1537 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1538 list = &pcp->lists[migratetype];
1539 if (list_empty(list)) {
1540 pcp->count += rmqueue_bulk(zone, 0,
1543 if (unlikely(list_empty(list)))
1548 page = list_entry(list->prev, struct page, lru);
1550 page = list_entry(list->next, struct page, lru);
1552 list_del(&page->lru);
1555 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1557 * __GFP_NOFAIL is not to be used in new code.
1559 * All __GFP_NOFAIL callers should be fixed so that they
1560 * properly detect and handle allocation failures.
1562 * We most definitely don't want callers attempting to
1563 * allocate greater than order-1 page units with
1566 WARN_ON_ONCE(order > 1);
1568 spin_lock_irqsave(&zone->lock, flags);
1569 page = __rmqueue(zone, order, migratetype);
1570 spin_unlock(&zone->lock);
1573 __mod_zone_freepage_state(zone, -(1 << order),
1574 get_pageblock_migratetype(page));
1577 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
1578 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1579 zone_statistics(preferred_zone, zone, gfp_flags);
1580 local_irq_restore(flags);
1582 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1583 if (prep_new_page(page, order, gfp_flags))
1588 local_irq_restore(flags);
1592 #ifdef CONFIG_FAIL_PAGE_ALLOC
1595 struct fault_attr attr;
1597 u32 ignore_gfp_highmem;
1598 u32 ignore_gfp_wait;
1600 } fail_page_alloc = {
1601 .attr = FAULT_ATTR_INITIALIZER,
1602 .ignore_gfp_wait = 1,
1603 .ignore_gfp_highmem = 1,
1607 static int __init setup_fail_page_alloc(char *str)
1609 return setup_fault_attr(&fail_page_alloc.attr, str);
1611 __setup("fail_page_alloc=", setup_fail_page_alloc);
1613 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1615 if (order < fail_page_alloc.min_order)
1617 if (gfp_mask & __GFP_NOFAIL)
1619 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1621 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1624 return should_fail(&fail_page_alloc.attr, 1 << order);
1627 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1629 static int __init fail_page_alloc_debugfs(void)
1631 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1634 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1635 &fail_page_alloc.attr);
1637 return PTR_ERR(dir);
1639 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1640 &fail_page_alloc.ignore_gfp_wait))
1642 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1643 &fail_page_alloc.ignore_gfp_highmem))
1645 if (!debugfs_create_u32("min-order", mode, dir,
1646 &fail_page_alloc.min_order))
1651 debugfs_remove_recursive(dir);
1656 late_initcall(fail_page_alloc_debugfs);
1658 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1660 #else /* CONFIG_FAIL_PAGE_ALLOC */
1662 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1667 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1670 * Return true if free pages are above 'mark'. This takes into account the order
1671 * of the allocation.
1673 static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1674 int classzone_idx, int alloc_flags, long free_pages)
1676 /* free_pages my go negative - that's OK */
1678 long lowmem_reserve = z->lowmem_reserve[classzone_idx];
1682 free_pages -= (1 << order) - 1;
1683 if (alloc_flags & ALLOC_HIGH)
1685 if (alloc_flags & ALLOC_HARDER)
1688 /* If allocation can't use CMA areas don't use free CMA pages */
1689 if (!(alloc_flags & ALLOC_CMA))
1690 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
1693 if (free_pages - free_cma <= min + lowmem_reserve)
1695 for (o = 0; o < order; o++) {
1696 /* At the next order, this order's pages become unavailable */
1697 free_pages -= z->free_area[o].nr_free << o;
1699 /* Require fewer higher order pages to be free */
1702 if (free_pages <= min)
1708 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1709 int classzone_idx, int alloc_flags)
1711 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1712 zone_page_state(z, NR_FREE_PAGES));
1715 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
1716 int classzone_idx, int alloc_flags)
1718 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1720 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1721 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1723 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1729 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1730 * skip over zones that are not allowed by the cpuset, or that have
1731 * been recently (in last second) found to be nearly full. See further
1732 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1733 * that have to skip over a lot of full or unallowed zones.
1735 * If the zonelist cache is present in the passed zonelist, then
1736 * returns a pointer to the allowed node mask (either the current
1737 * tasks mems_allowed, or node_states[N_MEMORY].)
1739 * If the zonelist cache is not available for this zonelist, does
1740 * nothing and returns NULL.
1742 * If the fullzones BITMAP in the zonelist cache is stale (more than
1743 * a second since last zap'd) then we zap it out (clear its bits.)
1745 * We hold off even calling zlc_setup, until after we've checked the
1746 * first zone in the zonelist, on the theory that most allocations will
1747 * be satisfied from that first zone, so best to examine that zone as
1748 * quickly as we can.
1750 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1752 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1753 nodemask_t *allowednodes; /* zonelist_cache approximation */
1755 zlc = zonelist->zlcache_ptr;
1759 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1760 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1761 zlc->last_full_zap = jiffies;
1764 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1765 &cpuset_current_mems_allowed :
1766 &node_states[N_MEMORY];
1767 return allowednodes;
1771 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1772 * if it is worth looking at further for free memory:
1773 * 1) Check that the zone isn't thought to be full (doesn't have its
1774 * bit set in the zonelist_cache fullzones BITMAP).
1775 * 2) Check that the zones node (obtained from the zonelist_cache
1776 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1777 * Return true (non-zero) if zone is worth looking at further, or
1778 * else return false (zero) if it is not.
1780 * This check -ignores- the distinction between various watermarks,
1781 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1782 * found to be full for any variation of these watermarks, it will
1783 * be considered full for up to one second by all requests, unless
1784 * we are so low on memory on all allowed nodes that we are forced
1785 * into the second scan of the zonelist.
1787 * In the second scan we ignore this zonelist cache and exactly
1788 * apply the watermarks to all zones, even it is slower to do so.
1789 * We are low on memory in the second scan, and should leave no stone
1790 * unturned looking for a free page.
1792 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1793 nodemask_t *allowednodes)
1795 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1796 int i; /* index of *z in zonelist zones */
1797 int n; /* node that zone *z is on */
1799 zlc = zonelist->zlcache_ptr;
1803 i = z - zonelist->_zonerefs;
1806 /* This zone is worth trying if it is allowed but not full */
1807 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1811 * Given 'z' scanning a zonelist, set the corresponding bit in
1812 * zlc->fullzones, so that subsequent attempts to allocate a page
1813 * from that zone don't waste time re-examining it.
1815 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1817 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1818 int i; /* index of *z in zonelist zones */
1820 zlc = zonelist->zlcache_ptr;
1824 i = z - zonelist->_zonerefs;
1826 set_bit(i, zlc->fullzones);
1830 * clear all zones full, called after direct reclaim makes progress so that
1831 * a zone that was recently full is not skipped over for up to a second
1833 static void zlc_clear_zones_full(struct zonelist *zonelist)
1835 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1837 zlc = zonelist->zlcache_ptr;
1841 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1844 static bool zone_local(struct zone *local_zone, struct zone *zone)
1846 return local_zone->node == zone->node;
1849 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1851 return node_isset(local_zone->node, zone->zone_pgdat->reclaim_nodes);
1854 static void __paginginit init_zone_allows_reclaim(int nid)
1858 for_each_online_node(i)
1859 if (node_distance(nid, i) <= RECLAIM_DISTANCE)
1860 node_set(i, NODE_DATA(nid)->reclaim_nodes);
1862 zone_reclaim_mode = 1;
1865 #else /* CONFIG_NUMA */
1867 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1872 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1873 nodemask_t *allowednodes)
1878 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1882 static void zlc_clear_zones_full(struct zonelist *zonelist)
1886 static bool zone_local(struct zone *local_zone, struct zone *zone)
1891 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1896 static inline void init_zone_allows_reclaim(int nid)
1899 #endif /* CONFIG_NUMA */
1902 * get_page_from_freelist goes through the zonelist trying to allocate
1905 static struct page *
1906 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1907 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1908 struct zone *preferred_zone, int migratetype)
1911 struct page *page = NULL;
1914 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1915 int zlc_active = 0; /* set if using zonelist_cache */
1916 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1918 classzone_idx = zone_idx(preferred_zone);
1921 * Scan zonelist, looking for a zone with enough free.
1922 * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
1924 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1925 high_zoneidx, nodemask) {
1928 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1929 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1931 if ((alloc_flags & ALLOC_CPUSET) &&
1932 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1934 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1935 if (unlikely(alloc_flags & ALLOC_NO_WATERMARKS))
1938 * Distribute pages in proportion to the individual
1939 * zone size to ensure fair page aging. The zone a
1940 * page was allocated in should have no effect on the
1941 * time the page has in memory before being reclaimed.
1943 * Try to stay in local zones in the fastpath. If
1944 * that fails, the slowpath is entered, which will do
1945 * another pass starting with the local zones, but
1946 * ultimately fall back to remote zones that do not
1947 * partake in the fairness round-robin cycle of this
1950 if (alloc_flags & ALLOC_WMARK_LOW) {
1951 if (zone_page_state(zone, NR_ALLOC_BATCH) <= 0)
1953 if (!zone_local(preferred_zone, zone))
1957 * When allocating a page cache page for writing, we
1958 * want to get it from a zone that is within its dirty
1959 * limit, such that no single zone holds more than its
1960 * proportional share of globally allowed dirty pages.
1961 * The dirty limits take into account the zone's
1962 * lowmem reserves and high watermark so that kswapd
1963 * should be able to balance it without having to
1964 * write pages from its LRU list.
1966 * This may look like it could increase pressure on
1967 * lower zones by failing allocations in higher zones
1968 * before they are full. But the pages that do spill
1969 * over are limited as the lower zones are protected
1970 * by this very same mechanism. It should not become
1971 * a practical burden to them.
1973 * XXX: For now, allow allocations to potentially
1974 * exceed the per-zone dirty limit in the slowpath
1975 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1976 * which is important when on a NUMA setup the allowed
1977 * zones are together not big enough to reach the
1978 * global limit. The proper fix for these situations
1979 * will require awareness of zones in the
1980 * dirty-throttling and the flusher threads.
1982 if ((alloc_flags & ALLOC_WMARK_LOW) &&
1983 (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone))
1984 goto this_zone_full;
1986 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1987 if (!zone_watermark_ok(zone, order, mark,
1988 classzone_idx, alloc_flags)) {
1991 if (IS_ENABLED(CONFIG_NUMA) &&
1992 !did_zlc_setup && nr_online_nodes > 1) {
1994 * we do zlc_setup if there are multiple nodes
1995 * and before considering the first zone allowed
1998 allowednodes = zlc_setup(zonelist, alloc_flags);
2003 if (zone_reclaim_mode == 0 ||
2004 !zone_allows_reclaim(preferred_zone, zone))
2005 goto this_zone_full;
2008 * As we may have just activated ZLC, check if the first
2009 * eligible zone has failed zone_reclaim recently.
2011 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2012 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2015 ret = zone_reclaim(zone, gfp_mask, order);
2017 case ZONE_RECLAIM_NOSCAN:
2020 case ZONE_RECLAIM_FULL:
2021 /* scanned but unreclaimable */
2024 /* did we reclaim enough */
2025 if (zone_watermark_ok(zone, order, mark,
2026 classzone_idx, alloc_flags))
2030 * Failed to reclaim enough to meet watermark.
2031 * Only mark the zone full if checking the min
2032 * watermark or if we failed to reclaim just
2033 * 1<<order pages or else the page allocator
2034 * fastpath will prematurely mark zones full
2035 * when the watermark is between the low and
2038 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2039 ret == ZONE_RECLAIM_SOME)
2040 goto this_zone_full;
2047 page = buffered_rmqueue(preferred_zone, zone, order,
2048 gfp_mask, migratetype);
2052 if (IS_ENABLED(CONFIG_NUMA))
2053 zlc_mark_zone_full(zonelist, z);
2056 if (unlikely(IS_ENABLED(CONFIG_NUMA) && page == NULL && zlc_active)) {
2057 /* Disable zlc cache for second zonelist scan */
2064 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
2065 * necessary to allocate the page. The expectation is
2066 * that the caller is taking steps that will free more
2067 * memory. The caller should avoid the page being used
2068 * for !PFMEMALLOC purposes.
2070 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
2076 * Large machines with many possible nodes should not always dump per-node
2077 * meminfo in irq context.
2079 static inline bool should_suppress_show_mem(void)
2084 ret = in_interrupt();
2089 static DEFINE_RATELIMIT_STATE(nopage_rs,
2090 DEFAULT_RATELIMIT_INTERVAL,
2091 DEFAULT_RATELIMIT_BURST);
2093 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2095 unsigned int filter = SHOW_MEM_FILTER_NODES;
2097 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2098 debug_guardpage_minorder() > 0)
2102 * This documents exceptions given to allocations in certain
2103 * contexts that are allowed to allocate outside current's set
2106 if (!(gfp_mask & __GFP_NOMEMALLOC))
2107 if (test_thread_flag(TIF_MEMDIE) ||
2108 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2109 filter &= ~SHOW_MEM_FILTER_NODES;
2110 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2111 filter &= ~SHOW_MEM_FILTER_NODES;
2114 struct va_format vaf;
2117 va_start(args, fmt);
2122 pr_warn("%pV", &vaf);
2127 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2128 current->comm, order, gfp_mask);
2131 if (!should_suppress_show_mem())
2136 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2137 unsigned long did_some_progress,
2138 unsigned long pages_reclaimed)
2140 /* Do not loop if specifically requested */
2141 if (gfp_mask & __GFP_NORETRY)
2144 /* Always retry if specifically requested */
2145 if (gfp_mask & __GFP_NOFAIL)
2149 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2150 * making forward progress without invoking OOM. Suspend also disables
2151 * storage devices so kswapd will not help. Bail if we are suspending.
2153 if (!did_some_progress && pm_suspended_storage())
2157 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2158 * means __GFP_NOFAIL, but that may not be true in other
2161 if (order <= PAGE_ALLOC_COSTLY_ORDER)
2165 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2166 * specified, then we retry until we no longer reclaim any pages
2167 * (above), or we've reclaimed an order of pages at least as
2168 * large as the allocation's order. In both cases, if the
2169 * allocation still fails, we stop retrying.
2171 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
2177 static inline struct page *
2178 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2179 struct zonelist *zonelist, enum zone_type high_zoneidx,
2180 nodemask_t *nodemask, struct zone *preferred_zone,
2185 /* Acquire the OOM killer lock for the zones in zonelist */
2186 if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
2187 schedule_timeout_uninterruptible(1);
2192 * Go through the zonelist yet one more time, keep very high watermark
2193 * here, this is only to catch a parallel oom killing, we must fail if
2194 * we're still under heavy pressure.
2196 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
2197 order, zonelist, high_zoneidx,
2198 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2199 preferred_zone, migratetype);
2203 if (!(gfp_mask & __GFP_NOFAIL)) {
2204 /* The OOM killer will not help higher order allocs */
2205 if (order > PAGE_ALLOC_COSTLY_ORDER)
2207 /* The OOM killer does not needlessly kill tasks for lowmem */
2208 if (high_zoneidx < ZONE_NORMAL)
2211 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2212 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2213 * The caller should handle page allocation failure by itself if
2214 * it specifies __GFP_THISNODE.
2215 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2217 if (gfp_mask & __GFP_THISNODE)
2220 /* Exhausted what can be done so it's blamo time */
2221 out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2224 clear_zonelist_oom(zonelist, gfp_mask);
2228 #ifdef CONFIG_COMPACTION
2229 /* Try memory compaction for high-order allocations before reclaim */
2230 static struct page *
2231 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2232 struct zonelist *zonelist, enum zone_type high_zoneidx,
2233 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2234 int migratetype, bool sync_migration,
2235 bool *contended_compaction, bool *deferred_compaction,
2236 unsigned long *did_some_progress)
2241 if (compaction_deferred(preferred_zone, order)) {
2242 *deferred_compaction = true;
2246 current->flags |= PF_MEMALLOC;
2247 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2248 nodemask, sync_migration,
2249 contended_compaction);
2250 current->flags &= ~PF_MEMALLOC;
2252 if (*did_some_progress != COMPACT_SKIPPED) {
2255 /* Page migration frees to the PCP lists but we want merging */
2256 drain_pages(get_cpu());
2259 page = get_page_from_freelist(gfp_mask, nodemask,
2260 order, zonelist, high_zoneidx,
2261 alloc_flags & ~ALLOC_NO_WATERMARKS,
2262 preferred_zone, migratetype);
2264 preferred_zone->compact_blockskip_flush = false;
2265 compaction_defer_reset(preferred_zone, order, true);
2266 count_vm_event(COMPACTSUCCESS);
2271 * It's bad if compaction run occurs and fails.
2272 * The most likely reason is that pages exist,
2273 * but not enough to satisfy watermarks.
2275 count_vm_event(COMPACTFAIL);
2278 * As async compaction considers a subset of pageblocks, only
2279 * defer if the failure was a sync compaction failure.
2282 defer_compaction(preferred_zone, order);
2290 static inline struct page *
2291 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2292 struct zonelist *zonelist, enum zone_type high_zoneidx,
2293 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2294 int migratetype, bool sync_migration,
2295 bool *contended_compaction, bool *deferred_compaction,
2296 unsigned long *did_some_progress)
2300 #endif /* CONFIG_COMPACTION */
2302 /* Perform direct synchronous page reclaim */
2304 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
2305 nodemask_t *nodemask)
2307 struct reclaim_state reclaim_state;
2312 /* We now go into synchronous reclaim */
2313 cpuset_memory_pressure_bump();
2314 current->flags |= PF_MEMALLOC;
2315 lockdep_set_current_reclaim_state(gfp_mask);
2316 reclaim_state.reclaimed_slab = 0;
2317 current->reclaim_state = &reclaim_state;
2319 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2321 current->reclaim_state = NULL;
2322 lockdep_clear_current_reclaim_state();
2323 current->flags &= ~PF_MEMALLOC;
2330 /* The really slow allocator path where we enter direct reclaim */
2331 static inline struct page *
2332 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2333 struct zonelist *zonelist, enum zone_type high_zoneidx,
2334 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2335 int migratetype, unsigned long *did_some_progress)
2337 struct page *page = NULL;
2338 bool drained = false;
2340 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
2342 if (unlikely(!(*did_some_progress)))
2345 /* After successful reclaim, reconsider all zones for allocation */
2346 if (IS_ENABLED(CONFIG_NUMA))
2347 zlc_clear_zones_full(zonelist);
2350 page = get_page_from_freelist(gfp_mask, nodemask, order,
2351 zonelist, high_zoneidx,
2352 alloc_flags & ~ALLOC_NO_WATERMARKS,
2353 preferred_zone, migratetype);
2356 * If an allocation failed after direct reclaim, it could be because
2357 * pages are pinned on the per-cpu lists. Drain them and try again
2359 if (!page && !drained) {
2369 * This is called in the allocator slow-path if the allocation request is of
2370 * sufficient urgency to ignore watermarks and take other desperate measures
2372 static inline struct page *
2373 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2374 struct zonelist *zonelist, enum zone_type high_zoneidx,
2375 nodemask_t *nodemask, struct zone *preferred_zone,
2381 page = get_page_from_freelist(gfp_mask, nodemask, order,
2382 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2383 preferred_zone, migratetype);
2385 if (!page && gfp_mask & __GFP_NOFAIL)
2386 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2387 } while (!page && (gfp_mask & __GFP_NOFAIL));
2392 static void prepare_slowpath(gfp_t gfp_mask, unsigned int order,
2393 struct zonelist *zonelist,
2394 enum zone_type high_zoneidx,
2395 struct zone *preferred_zone)
2400 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
2401 if (!(gfp_mask & __GFP_NO_KSWAPD))
2402 wakeup_kswapd(zone, order, zone_idx(preferred_zone));
2404 * Only reset the batches of zones that were actually
2405 * considered in the fast path, we don't want to
2406 * thrash fairness information for zones that are not
2407 * actually part of this zonelist's round-robin cycle.
2409 if (!zone_local(preferred_zone, zone))
2411 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2412 high_wmark_pages(zone) -
2413 low_wmark_pages(zone) -
2414 zone_page_state(zone, NR_ALLOC_BATCH));
2419 gfp_to_alloc_flags(gfp_t gfp_mask)
2421 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2422 const gfp_t wait = gfp_mask & __GFP_WAIT;
2424 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2425 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2428 * The caller may dip into page reserves a bit more if the caller
2429 * cannot run direct reclaim, or if the caller has realtime scheduling
2430 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2431 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2433 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2437 * Not worth trying to allocate harder for
2438 * __GFP_NOMEMALLOC even if it can't schedule.
2440 if (!(gfp_mask & __GFP_NOMEMALLOC))
2441 alloc_flags |= ALLOC_HARDER;
2443 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2444 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2446 alloc_flags &= ~ALLOC_CPUSET;
2447 } else if (unlikely(rt_task(current)) && !in_interrupt())
2448 alloc_flags |= ALLOC_HARDER;
2450 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2451 if (gfp_mask & __GFP_MEMALLOC)
2452 alloc_flags |= ALLOC_NO_WATERMARKS;
2453 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2454 alloc_flags |= ALLOC_NO_WATERMARKS;
2455 else if (!in_interrupt() &&
2456 ((current->flags & PF_MEMALLOC) ||
2457 unlikely(test_thread_flag(TIF_MEMDIE))))
2458 alloc_flags |= ALLOC_NO_WATERMARKS;
2461 if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2462 alloc_flags |= ALLOC_CMA;
2467 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2469 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2472 static inline struct page *
2473 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2474 struct zonelist *zonelist, enum zone_type high_zoneidx,
2475 nodemask_t *nodemask, struct zone *preferred_zone,
2478 const gfp_t wait = gfp_mask & __GFP_WAIT;
2479 struct page *page = NULL;
2481 unsigned long pages_reclaimed = 0;
2482 unsigned long did_some_progress;
2483 bool sync_migration = false;
2484 bool deferred_compaction = false;
2485 bool contended_compaction = false;
2488 * In the slowpath, we sanity check order to avoid ever trying to
2489 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2490 * be using allocators in order of preference for an area that is
2493 if (order >= MAX_ORDER) {
2494 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2499 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2500 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2501 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2502 * using a larger set of nodes after it has established that the
2503 * allowed per node queues are empty and that nodes are
2506 if (IS_ENABLED(CONFIG_NUMA) &&
2507 (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2511 prepare_slowpath(gfp_mask, order, zonelist,
2512 high_zoneidx, preferred_zone);
2515 * OK, we're below the kswapd watermark and have kicked background
2516 * reclaim. Now things get more complex, so set up alloc_flags according
2517 * to how we want to proceed.
2519 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2522 * Find the true preferred zone if the allocation is unconstrained by
2525 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
2526 first_zones_zonelist(zonelist, high_zoneidx, NULL,
2530 /* This is the last chance, in general, before the goto nopage. */
2531 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2532 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2533 preferred_zone, migratetype);
2537 /* Allocate without watermarks if the context allows */
2538 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2540 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2541 * the allocation is high priority and these type of
2542 * allocations are system rather than user orientated
2544 zonelist = node_zonelist(numa_node_id(), gfp_mask);
2546 page = __alloc_pages_high_priority(gfp_mask, order,
2547 zonelist, high_zoneidx, nodemask,
2548 preferred_zone, migratetype);
2554 /* Atomic allocations - we can't balance anything */
2557 * All existing users of the deprecated __GFP_NOFAIL are
2558 * blockable, so warn of any new users that actually allow this
2559 * type of allocation to fail.
2561 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
2565 /* Avoid recursion of direct reclaim */
2566 if (current->flags & PF_MEMALLOC)
2569 /* Avoid allocations with no watermarks from looping endlessly */
2570 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2574 * Try direct compaction. The first pass is asynchronous. Subsequent
2575 * attempts after direct reclaim are synchronous
2577 page = __alloc_pages_direct_compact(gfp_mask, order,
2578 zonelist, high_zoneidx,
2580 alloc_flags, preferred_zone,
2581 migratetype, sync_migration,
2582 &contended_compaction,
2583 &deferred_compaction,
2584 &did_some_progress);
2587 sync_migration = true;
2590 * If compaction is deferred for high-order allocations, it is because
2591 * sync compaction recently failed. In this is the case and the caller
2592 * requested a movable allocation that does not heavily disrupt the
2593 * system then fail the allocation instead of entering direct reclaim.
2595 if ((deferred_compaction || contended_compaction) &&
2596 (gfp_mask & __GFP_NO_KSWAPD))
2599 /* Try direct reclaim and then allocating */
2600 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2601 zonelist, high_zoneidx,
2603 alloc_flags, preferred_zone,
2604 migratetype, &did_some_progress);
2609 * If we failed to make any progress reclaiming, then we are
2610 * running out of options and have to consider going OOM
2612 if (!did_some_progress) {
2613 if (oom_gfp_allowed(gfp_mask)) {
2614 if (oom_killer_disabled)
2616 /* Coredumps can quickly deplete all memory reserves */
2617 if ((current->flags & PF_DUMPCORE) &&
2618 !(gfp_mask & __GFP_NOFAIL))
2620 page = __alloc_pages_may_oom(gfp_mask, order,
2621 zonelist, high_zoneidx,
2622 nodemask, preferred_zone,
2627 if (!(gfp_mask & __GFP_NOFAIL)) {
2629 * The oom killer is not called for high-order
2630 * allocations that may fail, so if no progress
2631 * is being made, there are no other options and
2632 * retrying is unlikely to help.
2634 if (order > PAGE_ALLOC_COSTLY_ORDER)
2637 * The oom killer is not called for lowmem
2638 * allocations to prevent needlessly killing
2641 if (high_zoneidx < ZONE_NORMAL)
2649 /* Check if we should retry the allocation */
2650 pages_reclaimed += did_some_progress;
2651 if (should_alloc_retry(gfp_mask, order, did_some_progress,
2653 /* Wait for some write requests to complete then retry */
2654 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2658 * High-order allocations do not necessarily loop after
2659 * direct reclaim and reclaim/compaction depends on compaction
2660 * being called after reclaim so call directly if necessary
2662 page = __alloc_pages_direct_compact(gfp_mask, order,
2663 zonelist, high_zoneidx,
2665 alloc_flags, preferred_zone,
2666 migratetype, sync_migration,
2667 &contended_compaction,
2668 &deferred_compaction,
2669 &did_some_progress);
2675 warn_alloc_failed(gfp_mask, order, NULL);
2678 if (kmemcheck_enabled)
2679 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2685 * This is the 'heart' of the zoned buddy allocator.
2688 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2689 struct zonelist *zonelist, nodemask_t *nodemask)
2691 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2692 struct zone *preferred_zone;
2693 struct page *page = NULL;
2694 int migratetype = allocflags_to_migratetype(gfp_mask);
2695 unsigned int cpuset_mems_cookie;
2696 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
2697 struct mem_cgroup *memcg = NULL;
2699 gfp_mask &= gfp_allowed_mask;
2701 lockdep_trace_alloc(gfp_mask);
2703 might_sleep_if(gfp_mask & __GFP_WAIT);
2705 if (should_fail_alloc_page(gfp_mask, order))
2709 * Check the zones suitable for the gfp_mask contain at least one
2710 * valid zone. It's possible to have an empty zonelist as a result
2711 * of GFP_THISNODE and a memoryless node
2713 if (unlikely(!zonelist->_zonerefs->zone))
2717 * Will only have any effect when __GFP_KMEMCG is set. This is
2718 * verified in the (always inline) callee
2720 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2724 cpuset_mems_cookie = get_mems_allowed();
2726 /* The preferred zone is used for statistics later */
2727 first_zones_zonelist(zonelist, high_zoneidx,
2728 nodemask ? : &cpuset_current_mems_allowed,
2730 if (!preferred_zone)
2734 if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2735 alloc_flags |= ALLOC_CMA;
2737 /* First allocation attempt */
2738 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2739 zonelist, high_zoneidx, alloc_flags,
2740 preferred_zone, migratetype);
2741 if (unlikely(!page)) {
2743 * Runtime PM, block IO and its error handling path
2744 * can deadlock because I/O on the device might not
2747 gfp_mask = memalloc_noio_flags(gfp_mask);
2748 page = __alloc_pages_slowpath(gfp_mask, order,
2749 zonelist, high_zoneidx, nodemask,
2750 preferred_zone, migratetype);
2753 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2757 * When updating a task's mems_allowed, it is possible to race with
2758 * parallel threads in such a way that an allocation can fail while
2759 * the mask is being updated. If a page allocation is about to fail,
2760 * check if the cpuset changed during allocation and if so, retry.
2762 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
2765 memcg_kmem_commit_charge(page, memcg, order);
2769 EXPORT_SYMBOL(__alloc_pages_nodemask);
2772 * Common helper functions.
2774 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2779 * __get_free_pages() returns a 32-bit address, which cannot represent
2782 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2784 page = alloc_pages(gfp_mask, order);
2787 return (unsigned long) page_address(page);
2789 EXPORT_SYMBOL(__get_free_pages);
2791 unsigned long get_zeroed_page(gfp_t gfp_mask)
2793 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2795 EXPORT_SYMBOL(get_zeroed_page);
2797 void __free_pages(struct page *page, unsigned int order)
2799 if (put_page_testzero(page)) {
2801 free_hot_cold_page(page, 0);
2803 __free_pages_ok(page, order);
2807 EXPORT_SYMBOL(__free_pages);
2809 void free_pages(unsigned long addr, unsigned int order)
2812 VM_BUG_ON(!virt_addr_valid((void *)addr));
2813 __free_pages(virt_to_page((void *)addr), order);
2817 EXPORT_SYMBOL(free_pages);
2820 * __free_memcg_kmem_pages and free_memcg_kmem_pages will free
2821 * pages allocated with __GFP_KMEMCG.
2823 * Those pages are accounted to a particular memcg, embedded in the
2824 * corresponding page_cgroup. To avoid adding a hit in the allocator to search
2825 * for that information only to find out that it is NULL for users who have no
2826 * interest in that whatsoever, we provide these functions.
2828 * The caller knows better which flags it relies on.
2830 void __free_memcg_kmem_pages(struct page *page, unsigned int order)
2832 memcg_kmem_uncharge_pages(page, order);
2833 __free_pages(page, order);
2836 void free_memcg_kmem_pages(unsigned long addr, unsigned int order)
2839 VM_BUG_ON(!virt_addr_valid((void *)addr));
2840 __free_memcg_kmem_pages(virt_to_page((void *)addr), order);
2844 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2847 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2848 unsigned long used = addr + PAGE_ALIGN(size);
2850 split_page(virt_to_page((void *)addr), order);
2851 while (used < alloc_end) {
2856 return (void *)addr;
2860 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2861 * @size: the number of bytes to allocate
2862 * @gfp_mask: GFP flags for the allocation
2864 * This function is similar to alloc_pages(), except that it allocates the
2865 * minimum number of pages to satisfy the request. alloc_pages() can only
2866 * allocate memory in power-of-two pages.
2868 * This function is also limited by MAX_ORDER.
2870 * Memory allocated by this function must be released by free_pages_exact().
2872 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2874 unsigned int order = get_order(size);
2877 addr = __get_free_pages(gfp_mask, order);
2878 return make_alloc_exact(addr, order, size);
2880 EXPORT_SYMBOL(alloc_pages_exact);
2883 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2885 * @nid: the preferred node ID where memory should be allocated
2886 * @size: the number of bytes to allocate
2887 * @gfp_mask: GFP flags for the allocation
2889 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2891 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2894 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2896 unsigned order = get_order(size);
2897 struct page *p = alloc_pages_node(nid, gfp_mask, order);
2900 return make_alloc_exact((unsigned long)page_address(p), order, size);
2902 EXPORT_SYMBOL(alloc_pages_exact_nid);
2905 * free_pages_exact - release memory allocated via alloc_pages_exact()
2906 * @virt: the value returned by alloc_pages_exact.
2907 * @size: size of allocation, same value as passed to alloc_pages_exact().
2909 * Release the memory allocated by a previous call to alloc_pages_exact.
2911 void free_pages_exact(void *virt, size_t size)
2913 unsigned long addr = (unsigned long)virt;
2914 unsigned long end = addr + PAGE_ALIGN(size);
2916 while (addr < end) {
2921 EXPORT_SYMBOL(free_pages_exact);
2924 * nr_free_zone_pages - count number of pages beyond high watermark
2925 * @offset: The zone index of the highest zone
2927 * nr_free_zone_pages() counts the number of counts pages which are beyond the
2928 * high watermark within all zones at or below a given zone index. For each
2929 * zone, the number of pages is calculated as:
2930 * managed_pages - high_pages
2932 static unsigned long nr_free_zone_pages(int offset)
2937 /* Just pick one node, since fallback list is circular */
2938 unsigned long sum = 0;
2940 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2942 for_each_zone_zonelist(zone, z, zonelist, offset) {
2943 unsigned long size = zone->managed_pages;
2944 unsigned long high = high_wmark_pages(zone);
2953 * nr_free_buffer_pages - count number of pages beyond high watermark
2955 * nr_free_buffer_pages() counts the number of pages which are beyond the high
2956 * watermark within ZONE_DMA and ZONE_NORMAL.
2958 unsigned long nr_free_buffer_pages(void)
2960 return nr_free_zone_pages(gfp_zone(GFP_USER));
2962 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2965 * nr_free_pagecache_pages - count number of pages beyond high watermark
2967 * nr_free_pagecache_pages() counts the number of pages which are beyond the
2968 * high watermark within all zones.
2970 unsigned long nr_free_pagecache_pages(void)
2972 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2975 static inline void show_node(struct zone *zone)
2977 if (IS_ENABLED(CONFIG_NUMA))
2978 printk("Node %d ", zone_to_nid(zone));
2981 void si_meminfo(struct sysinfo *val)
2983 val->totalram = totalram_pages;
2985 val->freeram = global_page_state(NR_FREE_PAGES);
2986 val->bufferram = nr_blockdev_pages();
2987 val->totalhigh = totalhigh_pages;
2988 val->freehigh = nr_free_highpages();
2989 val->mem_unit = PAGE_SIZE;
2992 EXPORT_SYMBOL(si_meminfo);
2995 void si_meminfo_node(struct sysinfo *val, int nid)
2997 int zone_type; /* needs to be signed */
2998 unsigned long managed_pages = 0;
2999 pg_data_t *pgdat = NODE_DATA(nid);
3001 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3002 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3003 val->totalram = managed_pages;
3004 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3005 #ifdef CONFIG_HIGHMEM
3006 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3007 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3013 val->mem_unit = PAGE_SIZE;
3018 * Determine whether the node should be displayed or not, depending on whether
3019 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3021 bool skip_free_areas_node(unsigned int flags, int nid)
3024 unsigned int cpuset_mems_cookie;
3026 if (!(flags & SHOW_MEM_FILTER_NODES))
3030 cpuset_mems_cookie = get_mems_allowed();
3031 ret = !node_isset(nid, cpuset_current_mems_allowed);
3032 } while (!put_mems_allowed(cpuset_mems_cookie));
3037 #define K(x) ((x) << (PAGE_SHIFT-10))
3039 static void show_migration_types(unsigned char type)
3041 static const char types[MIGRATE_TYPES] = {
3042 [MIGRATE_UNMOVABLE] = 'U',
3043 [MIGRATE_RECLAIMABLE] = 'E',
3044 [MIGRATE_MOVABLE] = 'M',
3045 [MIGRATE_RESERVE] = 'R',
3047 [MIGRATE_CMA] = 'C',
3049 #ifdef CONFIG_MEMORY_ISOLATION
3050 [MIGRATE_ISOLATE] = 'I',
3053 char tmp[MIGRATE_TYPES + 1];
3057 for (i = 0; i < MIGRATE_TYPES; i++) {
3058 if (type & (1 << i))
3063 printk("(%s) ", tmp);
3067 * Show free area list (used inside shift_scroll-lock stuff)
3068 * We also calculate the percentage fragmentation. We do this by counting the
3069 * memory on each free list with the exception of the first item on the list.
3070 * Suppresses nodes that are not allowed by current's cpuset if
3071 * SHOW_MEM_FILTER_NODES is passed.
3073 void show_free_areas(unsigned int filter)
3078 for_each_populated_zone(zone) {
3079 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3082 printk("%s per-cpu:\n", zone->name);
3084 for_each_online_cpu(cpu) {
3085 struct per_cpu_pageset *pageset;
3087 pageset = per_cpu_ptr(zone->pageset, cpu);
3089 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
3090 cpu, pageset->pcp.high,
3091 pageset->pcp.batch, pageset->pcp.count);
3095 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3096 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3098 " dirty:%lu writeback:%lu unstable:%lu\n"
3099 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3100 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3102 global_page_state(NR_ACTIVE_ANON),
3103 global_page_state(NR_INACTIVE_ANON),
3104 global_page_state(NR_ISOLATED_ANON),
3105 global_page_state(NR_ACTIVE_FILE),
3106 global_page_state(NR_INACTIVE_FILE),
3107 global_page_state(NR_ISOLATED_FILE),
3108 global_page_state(NR_UNEVICTABLE),
3109 global_page_state(NR_FILE_DIRTY),
3110 global_page_state(NR_WRITEBACK),
3111 global_page_state(NR_UNSTABLE_NFS),
3112 global_page_state(NR_FREE_PAGES),
3113 global_page_state(NR_SLAB_RECLAIMABLE),
3114 global_page_state(NR_SLAB_UNRECLAIMABLE),
3115 global_page_state(NR_FILE_MAPPED),
3116 global_page_state(NR_SHMEM),
3117 global_page_state(NR_PAGETABLE),
3118 global_page_state(NR_BOUNCE),
3119 global_page_state(NR_FREE_CMA_PAGES));
3121 for_each_populated_zone(zone) {
3124 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3132 " active_anon:%lukB"
3133 " inactive_anon:%lukB"
3134 " active_file:%lukB"
3135 " inactive_file:%lukB"
3136 " unevictable:%lukB"
3137 " isolated(anon):%lukB"
3138 " isolated(file):%lukB"
3146 " slab_reclaimable:%lukB"
3147 " slab_unreclaimable:%lukB"
3148 " kernel_stack:%lukB"
3153 " writeback_tmp:%lukB"
3154 " pages_scanned:%lu"
3155 " all_unreclaimable? %s"
3158 K(zone_page_state(zone, NR_FREE_PAGES)),
3159 K(min_wmark_pages(zone)),
3160 K(low_wmark_pages(zone)),
3161 K(high_wmark_pages(zone)),
3162 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3163 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3164 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3165 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3166 K(zone_page_state(zone, NR_UNEVICTABLE)),
3167 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3168 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3169 K(zone->present_pages),
3170 K(zone->managed_pages),
3171 K(zone_page_state(zone, NR_MLOCK)),
3172 K(zone_page_state(zone, NR_FILE_DIRTY)),
3173 K(zone_page_state(zone, NR_WRITEBACK)),
3174 K(zone_page_state(zone, NR_FILE_MAPPED)),
3175 K(zone_page_state(zone, NR_SHMEM)),
3176 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3177 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3178 zone_page_state(zone, NR_KERNEL_STACK) *
3180 K(zone_page_state(zone, NR_PAGETABLE)),
3181 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3182 K(zone_page_state(zone, NR_BOUNCE)),
3183 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3184 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3185 zone->pages_scanned,
3186 (!zone_reclaimable(zone) ? "yes" : "no")
3188 printk("lowmem_reserve[]:");
3189 for (i = 0; i < MAX_NR_ZONES; i++)
3190 printk(" %lu", zone->lowmem_reserve[i]);
3194 for_each_populated_zone(zone) {
3195 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3196 unsigned char types[MAX_ORDER];
3198 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3201 printk("%s: ", zone->name);
3203 spin_lock_irqsave(&zone->lock, flags);
3204 for (order = 0; order < MAX_ORDER; order++) {
3205 struct free_area *area = &zone->free_area[order];
3208 nr[order] = area->nr_free;
3209 total += nr[order] << order;
3212 for (type = 0; type < MIGRATE_TYPES; type++) {
3213 if (!list_empty(&area->free_list[type]))
3214 types[order] |= 1 << type;
3217 spin_unlock_irqrestore(&zone->lock, flags);
3218 for (order = 0; order < MAX_ORDER; order++) {
3219 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3221 show_migration_types(types[order]);
3223 printk("= %lukB\n", K(total));
3226 hugetlb_show_meminfo();
3228 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3230 show_swap_cache_info();
3233 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3235 zoneref->zone = zone;
3236 zoneref->zone_idx = zone_idx(zone);
3240 * Builds allocation fallback zone lists.
3242 * Add all populated zones of a node to the zonelist.
3244 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3248 enum zone_type zone_type = MAX_NR_ZONES;
3252 zone = pgdat->node_zones + zone_type;
3253 if (populated_zone(zone)) {
3254 zoneref_set_zone(zone,
3255 &zonelist->_zonerefs[nr_zones++]);
3256 check_highest_zone(zone_type);
3258 } while (zone_type);
3266 * 0 = automatic detection of better ordering.
3267 * 1 = order by ([node] distance, -zonetype)
3268 * 2 = order by (-zonetype, [node] distance)
3270 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3271 * the same zonelist. So only NUMA can configure this param.
3273 #define ZONELIST_ORDER_DEFAULT 0
3274 #define ZONELIST_ORDER_NODE 1
3275 #define ZONELIST_ORDER_ZONE 2
3277 /* zonelist order in the kernel.
3278 * set_zonelist_order() will set this to NODE or ZONE.
3280 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3281 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3285 /* The value user specified ....changed by config */
3286 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3287 /* string for sysctl */
3288 #define NUMA_ZONELIST_ORDER_LEN 16
3289 char numa_zonelist_order[16] = "default";
3292 * interface for configure zonelist ordering.
3293 * command line option "numa_zonelist_order"
3294 * = "[dD]efault - default, automatic configuration.
3295 * = "[nN]ode - order by node locality, then by zone within node
3296 * = "[zZ]one - order by zone, then by locality within zone
3299 static int __parse_numa_zonelist_order(char *s)
3301 if (*s == 'd' || *s == 'D') {
3302 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3303 } else if (*s == 'n' || *s == 'N') {
3304 user_zonelist_order = ZONELIST_ORDER_NODE;
3305 } else if (*s == 'z' || *s == 'Z') {
3306 user_zonelist_order = ZONELIST_ORDER_ZONE;
3309 "Ignoring invalid numa_zonelist_order value: "
3316 static __init int setup_numa_zonelist_order(char *s)
3323 ret = __parse_numa_zonelist_order(s);
3325 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3329 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3332 * sysctl handler for numa_zonelist_order
3334 int numa_zonelist_order_handler(ctl_table *table, int write,
3335 void __user *buffer, size_t *length,
3338 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3340 static DEFINE_MUTEX(zl_order_mutex);
3342 mutex_lock(&zl_order_mutex);
3344 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3348 strcpy(saved_string, (char *)table->data);
3350 ret = proc_dostring(table, write, buffer, length, ppos);
3354 int oldval = user_zonelist_order;
3356 ret = __parse_numa_zonelist_order((char *)table->data);
3359 * bogus value. restore saved string
3361 strncpy((char *)table->data, saved_string,
3362 NUMA_ZONELIST_ORDER_LEN);
3363 user_zonelist_order = oldval;
3364 } else if (oldval != user_zonelist_order) {
3365 mutex_lock(&zonelists_mutex);
3366 build_all_zonelists(NULL, NULL);
3367 mutex_unlock(&zonelists_mutex);
3371 mutex_unlock(&zl_order_mutex);
3376 #define MAX_NODE_LOAD (nr_online_nodes)
3377 static int node_load[MAX_NUMNODES];
3380 * find_next_best_node - find the next node that should appear in a given node's fallback list
3381 * @node: node whose fallback list we're appending
3382 * @used_node_mask: nodemask_t of already used nodes
3384 * We use a number of factors to determine which is the next node that should
3385 * appear on a given node's fallback list. The node should not have appeared
3386 * already in @node's fallback list, and it should be the next closest node
3387 * according to the distance array (which contains arbitrary distance values
3388 * from each node to each node in the system), and should also prefer nodes
3389 * with no CPUs, since presumably they'll have very little allocation pressure
3390 * on them otherwise.
3391 * It returns -1 if no node is found.
3393 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3396 int min_val = INT_MAX;
3397 int best_node = NUMA_NO_NODE;
3398 const struct cpumask *tmp = cpumask_of_node(0);
3400 /* Use the local node if we haven't already */
3401 if (!node_isset(node, *used_node_mask)) {
3402 node_set(node, *used_node_mask);
3406 for_each_node_state(n, N_MEMORY) {
3408 /* Don't want a node to appear more than once */
3409 if (node_isset(n, *used_node_mask))
3412 /* Use the distance array to find the distance */
3413 val = node_distance(node, n);
3415 /* Penalize nodes under us ("prefer the next node") */
3418 /* Give preference to headless and unused nodes */
3419 tmp = cpumask_of_node(n);
3420 if (!cpumask_empty(tmp))
3421 val += PENALTY_FOR_NODE_WITH_CPUS;
3423 /* Slight preference for less loaded node */
3424 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3425 val += node_load[n];
3427 if (val < min_val) {
3434 node_set(best_node, *used_node_mask);
3441 * Build zonelists ordered by node and zones within node.
3442 * This results in maximum locality--normal zone overflows into local
3443 * DMA zone, if any--but risks exhausting DMA zone.
3445 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3448 struct zonelist *zonelist;
3450 zonelist = &pgdat->node_zonelists[0];
3451 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3453 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3454 zonelist->_zonerefs[j].zone = NULL;
3455 zonelist->_zonerefs[j].zone_idx = 0;
3459 * Build gfp_thisnode zonelists
3461 static void build_thisnode_zonelists(pg_data_t *pgdat)
3464 struct zonelist *zonelist;
3466 zonelist = &pgdat->node_zonelists[1];
3467 j = build_zonelists_node(pgdat, zonelist, 0);
3468 zonelist->_zonerefs[j].zone = NULL;
3469 zonelist->_zonerefs[j].zone_idx = 0;
3473 * Build zonelists ordered by zone and nodes within zones.
3474 * This results in conserving DMA zone[s] until all Normal memory is
3475 * exhausted, but results in overflowing to remote node while memory
3476 * may still exist in local DMA zone.
3478 static int node_order[MAX_NUMNODES];
3480 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3483 int zone_type; /* needs to be signed */
3485 struct zonelist *zonelist;
3487 zonelist = &pgdat->node_zonelists[0];
3489 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3490 for (j = 0; j < nr_nodes; j++) {
3491 node = node_order[j];
3492 z = &NODE_DATA(node)->node_zones[zone_type];
3493 if (populated_zone(z)) {
3495 &zonelist->_zonerefs[pos++]);
3496 check_highest_zone(zone_type);
3500 zonelist->_zonerefs[pos].zone = NULL;
3501 zonelist->_zonerefs[pos].zone_idx = 0;
3504 static int default_zonelist_order(void)
3507 unsigned long low_kmem_size, total_size;
3511 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3512 * If they are really small and used heavily, the system can fall
3513 * into OOM very easily.
3514 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3516 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3519 for_each_online_node(nid) {
3520 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3521 z = &NODE_DATA(nid)->node_zones[zone_type];
3522 if (populated_zone(z)) {
3523 if (zone_type < ZONE_NORMAL)
3524 low_kmem_size += z->managed_pages;
3525 total_size += z->managed_pages;
3526 } else if (zone_type == ZONE_NORMAL) {
3528 * If any node has only lowmem, then node order
3529 * is preferred to allow kernel allocations
3530 * locally; otherwise, they can easily infringe
3531 * on other nodes when there is an abundance of
3532 * lowmem available to allocate from.
3534 return ZONELIST_ORDER_NODE;
3538 if (!low_kmem_size || /* there are no DMA area. */
3539 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
3540 return ZONELIST_ORDER_NODE;
3542 * look into each node's config.
3543 * If there is a node whose DMA/DMA32 memory is very big area on
3544 * local memory, NODE_ORDER may be suitable.
3546 average_size = total_size /
3547 (nodes_weight(node_states[N_MEMORY]) + 1);
3548 for_each_online_node(nid) {
3551 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3552 z = &NODE_DATA(nid)->node_zones[zone_type];
3553 if (populated_zone(z)) {
3554 if (zone_type < ZONE_NORMAL)
3555 low_kmem_size += z->present_pages;
3556 total_size += z->present_pages;
3559 if (low_kmem_size &&
3560 total_size > average_size && /* ignore small node */
3561 low_kmem_size > total_size * 70/100)
3562 return ZONELIST_ORDER_NODE;
3564 return ZONELIST_ORDER_ZONE;
3567 static void set_zonelist_order(void)
3569 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3570 current_zonelist_order = default_zonelist_order();
3572 current_zonelist_order = user_zonelist_order;
3575 static void build_zonelists(pg_data_t *pgdat)
3579 nodemask_t used_mask;
3580 int local_node, prev_node;
3581 struct zonelist *zonelist;
3582 int order = current_zonelist_order;
3584 /* initialize zonelists */
3585 for (i = 0; i < MAX_ZONELISTS; i++) {
3586 zonelist = pgdat->node_zonelists + i;
3587 zonelist->_zonerefs[0].zone = NULL;
3588 zonelist->_zonerefs[0].zone_idx = 0;
3591 /* NUMA-aware ordering of nodes */
3592 local_node = pgdat->node_id;
3593 load = nr_online_nodes;
3594 prev_node = local_node;
3595 nodes_clear(used_mask);
3597 memset(node_order, 0, sizeof(node_order));
3600 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3602 * We don't want to pressure a particular node.
3603 * So adding penalty to the first node in same
3604 * distance group to make it round-robin.
3606 if (node_distance(local_node, node) !=
3607 node_distance(local_node, prev_node))
3608 node_load[node] = load;
3612 if (order == ZONELIST_ORDER_NODE)
3613 build_zonelists_in_node_order(pgdat, node);
3615 node_order[j++] = node; /* remember order */
3618 if (order == ZONELIST_ORDER_ZONE) {
3619 /* calculate node order -- i.e., DMA last! */
3620 build_zonelists_in_zone_order(pgdat, j);
3623 build_thisnode_zonelists(pgdat);
3626 /* Construct the zonelist performance cache - see further mmzone.h */
3627 static void build_zonelist_cache(pg_data_t *pgdat)
3629 struct zonelist *zonelist;
3630 struct zonelist_cache *zlc;
3633 zonelist = &pgdat->node_zonelists[0];
3634 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3635 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3636 for (z = zonelist->_zonerefs; z->zone; z++)
3637 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3640 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3642 * Return node id of node used for "local" allocations.
3643 * I.e., first node id of first zone in arg node's generic zonelist.
3644 * Used for initializing percpu 'numa_mem', which is used primarily
3645 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3647 int local_memory_node(int node)
3651 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3652 gfp_zone(GFP_KERNEL),
3659 #else /* CONFIG_NUMA */
3661 static void set_zonelist_order(void)
3663 current_zonelist_order = ZONELIST_ORDER_ZONE;
3666 static void build_zonelists(pg_data_t *pgdat)
3668 int node, local_node;
3670 struct zonelist *zonelist;
3672 local_node = pgdat->node_id;
3674 zonelist = &pgdat->node_zonelists[0];
3675 j = build_zonelists_node(pgdat, zonelist, 0);
3678 * Now we build the zonelist so that it contains the zones
3679 * of all the other nodes.
3680 * We don't want to pressure a particular node, so when
3681 * building the zones for node N, we make sure that the
3682 * zones coming right after the local ones are those from
3683 * node N+1 (modulo N)
3685 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3686 if (!node_online(node))
3688 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3690 for (node = 0; node < local_node; node++) {
3691 if (!node_online(node))
3693 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3696 zonelist->_zonerefs[j].zone = NULL;
3697 zonelist->_zonerefs[j].zone_idx = 0;
3700 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3701 static void build_zonelist_cache(pg_data_t *pgdat)
3703 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3706 #endif /* CONFIG_NUMA */
3709 * Boot pageset table. One per cpu which is going to be used for all
3710 * zones and all nodes. The parameters will be set in such a way
3711 * that an item put on a list will immediately be handed over to
3712 * the buddy list. This is safe since pageset manipulation is done
3713 * with interrupts disabled.
3715 * The boot_pagesets must be kept even after bootup is complete for
3716 * unused processors and/or zones. They do play a role for bootstrapping
3717 * hotplugged processors.
3719 * zoneinfo_show() and maybe other functions do
3720 * not check if the processor is online before following the pageset pointer.
3721 * Other parts of the kernel may not check if the zone is available.
3723 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3724 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3725 static void setup_zone_pageset(struct zone *zone);
3728 * Global mutex to protect against size modification of zonelists
3729 * as well as to serialize pageset setup for the new populated zone.
3731 DEFINE_MUTEX(zonelists_mutex);
3733 /* return values int ....just for stop_machine() */
3734 static int __build_all_zonelists(void *data)
3738 pg_data_t *self = data;
3741 memset(node_load, 0, sizeof(node_load));
3744 if (self && !node_online(self->node_id)) {
3745 build_zonelists(self);
3746 build_zonelist_cache(self);
3749 for_each_online_node(nid) {
3750 pg_data_t *pgdat = NODE_DATA(nid);
3752 build_zonelists(pgdat);
3753 build_zonelist_cache(pgdat);
3757 * Initialize the boot_pagesets that are going to be used
3758 * for bootstrapping processors. The real pagesets for
3759 * each zone will be allocated later when the per cpu
3760 * allocator is available.
3762 * boot_pagesets are used also for bootstrapping offline
3763 * cpus if the system is already booted because the pagesets
3764 * are needed to initialize allocators on a specific cpu too.
3765 * F.e. the percpu allocator needs the page allocator which
3766 * needs the percpu allocator in order to allocate its pagesets
3767 * (a chicken-egg dilemma).
3769 for_each_possible_cpu(cpu) {
3770 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3772 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3774 * We now know the "local memory node" for each node--
3775 * i.e., the node of the first zone in the generic zonelist.
3776 * Set up numa_mem percpu variable for on-line cpus. During
3777 * boot, only the boot cpu should be on-line; we'll init the
3778 * secondary cpus' numa_mem as they come on-line. During
3779 * node/memory hotplug, we'll fixup all on-line cpus.
3781 if (cpu_online(cpu))
3782 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3790 * Called with zonelists_mutex held always
3791 * unless system_state == SYSTEM_BOOTING.
3793 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3795 set_zonelist_order();
3797 if (system_state == SYSTEM_BOOTING) {
3798 __build_all_zonelists(NULL);
3799 mminit_verify_zonelist();
3800 cpuset_init_current_mems_allowed();
3802 #ifdef CONFIG_MEMORY_HOTPLUG
3804 setup_zone_pageset(zone);
3806 /* we have to stop all cpus to guarantee there is no user
3808 stop_machine(__build_all_zonelists, pgdat, NULL);
3809 /* cpuset refresh routine should be here */
3811 vm_total_pages = nr_free_pagecache_pages();
3813 * Disable grouping by mobility if the number of pages in the
3814 * system is too low to allow the mechanism to work. It would be
3815 * more accurate, but expensive to check per-zone. This check is
3816 * made on memory-hotadd so a system can start with mobility
3817 * disabled and enable it later
3819 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3820 page_group_by_mobility_disabled = 1;
3822 page_group_by_mobility_disabled = 0;
3824 printk("Built %i zonelists in %s order, mobility grouping %s. "
3825 "Total pages: %ld\n",
3827 zonelist_order_name[current_zonelist_order],
3828 page_group_by_mobility_disabled ? "off" : "on",
3831 printk("Policy zone: %s\n", zone_names[policy_zone]);
3836 * Helper functions to size the waitqueue hash table.
3837 * Essentially these want to choose hash table sizes sufficiently
3838 * large so that collisions trying to wait on pages are rare.
3839 * But in fact, the number of active page waitqueues on typical
3840 * systems is ridiculously low, less than 200. So this is even
3841 * conservative, even though it seems large.
3843 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3844 * waitqueues, i.e. the size of the waitq table given the number of pages.
3846 #define PAGES_PER_WAITQUEUE 256
3848 #ifndef CONFIG_MEMORY_HOTPLUG
3849 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3851 unsigned long size = 1;
3853 pages /= PAGES_PER_WAITQUEUE;
3855 while (size < pages)
3859 * Once we have dozens or even hundreds of threads sleeping
3860 * on IO we've got bigger problems than wait queue collision.
3861 * Limit the size of the wait table to a reasonable size.
3863 size = min(size, 4096UL);
3865 return max(size, 4UL);
3869 * A zone's size might be changed by hot-add, so it is not possible to determine
3870 * a suitable size for its wait_table. So we use the maximum size now.
3872 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3874 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3875 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3876 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3878 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3879 * or more by the traditional way. (See above). It equals:
3881 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3882 * ia64(16K page size) : = ( 8G + 4M)byte.
3883 * powerpc (64K page size) : = (32G +16M)byte.
3885 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3892 * This is an integer logarithm so that shifts can be used later
3893 * to extract the more random high bits from the multiplicative
3894 * hash function before the remainder is taken.
3896 static inline unsigned long wait_table_bits(unsigned long size)
3902 * Check if a pageblock contains reserved pages
3904 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3908 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3909 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3916 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3917 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3918 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3919 * higher will lead to a bigger reserve which will get freed as contiguous
3920 * blocks as reclaim kicks in
3922 static void setup_zone_migrate_reserve(struct zone *zone)
3924 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3926 unsigned long block_migratetype;
3931 * Get the start pfn, end pfn and the number of blocks to reserve
3932 * We have to be careful to be aligned to pageblock_nr_pages to
3933 * make sure that we always check pfn_valid for the first page in
3936 start_pfn = zone->zone_start_pfn;
3937 end_pfn = zone_end_pfn(zone);
3938 start_pfn = roundup(start_pfn, pageblock_nr_pages);
3939 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3943 * Reserve blocks are generally in place to help high-order atomic
3944 * allocations that are short-lived. A min_free_kbytes value that
3945 * would result in more than 2 reserve blocks for atomic allocations
3946 * is assumed to be in place to help anti-fragmentation for the
3947 * future allocation of hugepages at runtime.
3949 reserve = min(2, reserve);
3950 old_reserve = zone->nr_migrate_reserve_block;
3952 /* When memory hot-add, we almost always need to do nothing */
3953 if (reserve == old_reserve)
3955 zone->nr_migrate_reserve_block = reserve;
3957 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3958 if (!pfn_valid(pfn))
3960 page = pfn_to_page(pfn);
3962 /* Watch out for overlapping nodes */
3963 if (page_to_nid(page) != zone_to_nid(zone))
3966 block_migratetype = get_pageblock_migratetype(page);
3968 /* Only test what is necessary when the reserves are not met */
3971 * Blocks with reserved pages will never free, skip
3974 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
3975 if (pageblock_is_reserved(pfn, block_end_pfn))
3978 /* If this block is reserved, account for it */
3979 if (block_migratetype == MIGRATE_RESERVE) {
3984 /* Suitable for reserving if this block is movable */
3985 if (block_migratetype == MIGRATE_MOVABLE) {
3986 set_pageblock_migratetype(page,
3988 move_freepages_block(zone, page,
3993 } else if (!old_reserve) {
3995 * At boot time we don't need to scan the whole zone
3996 * for turning off MIGRATE_RESERVE.
4002 * If the reserve is met and this is a previous reserved block,
4005 if (block_migratetype == MIGRATE_RESERVE) {
4006 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4007 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4013 * Initially all pages are reserved - free ones are freed
4014 * up by free_all_bootmem() once the early boot process is
4015 * done. Non-atomic initialization, single-pass.
4017 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4018 unsigned long start_pfn, enum memmap_context context)
4021 unsigned long end_pfn = start_pfn + size;
4025 if (highest_memmap_pfn < end_pfn - 1)
4026 highest_memmap_pfn = end_pfn - 1;
4028 z = &NODE_DATA(nid)->node_zones[zone];
4029 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4031 * There can be holes in boot-time mem_map[]s
4032 * handed to this function. They do not
4033 * exist on hotplugged memory.
4035 if (context == MEMMAP_EARLY) {
4036 if (!early_pfn_valid(pfn))
4038 if (!early_pfn_in_nid(pfn, nid))
4041 page = pfn_to_page(pfn);
4042 set_page_links(page, zone, nid, pfn);
4043 mminit_verify_page_links(page, zone, nid, pfn);
4044 init_page_count(page);
4045 page_mapcount_reset(page);
4046 page_cpupid_reset_last(page);
4047 SetPageReserved(page);
4049 * Mark the block movable so that blocks are reserved for
4050 * movable at startup. This will force kernel allocations
4051 * to reserve their blocks rather than leaking throughout
4052 * the address space during boot when many long-lived
4053 * kernel allocations are made. Later some blocks near
4054 * the start are marked MIGRATE_RESERVE by
4055 * setup_zone_migrate_reserve()
4057 * bitmap is created for zone's valid pfn range. but memmap
4058 * can be created for invalid pages (for alignment)
4059 * check here not to call set_pageblock_migratetype() against
4062 if ((z->zone_start_pfn <= pfn)
4063 && (pfn < zone_end_pfn(z))
4064 && !(pfn & (pageblock_nr_pages - 1)))
4065 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4067 INIT_LIST_HEAD(&page->lru);
4068 #ifdef WANT_PAGE_VIRTUAL
4069 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4070 if (!is_highmem_idx(zone))
4071 set_page_address(page, __va(pfn << PAGE_SHIFT));
4076 static void __meminit zone_init_free_lists(struct zone *zone)
4079 for_each_migratetype_order(order, t) {
4080 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4081 zone->free_area[order].nr_free = 0;
4085 #ifndef __HAVE_ARCH_MEMMAP_INIT
4086 #define memmap_init(size, nid, zone, start_pfn) \
4087 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4090 static int __meminit zone_batchsize(struct zone *zone)
4096 * The per-cpu-pages pools are set to around 1000th of the
4097 * size of the zone. But no more than 1/2 of a meg.
4099 * OK, so we don't know how big the cache is. So guess.
4101 batch = zone->managed_pages / 1024;
4102 if (batch * PAGE_SIZE > 512 * 1024)
4103 batch = (512 * 1024) / PAGE_SIZE;
4104 batch /= 4; /* We effectively *= 4 below */
4109 * Clamp the batch to a 2^n - 1 value. Having a power
4110 * of 2 value was found to be more likely to have
4111 * suboptimal cache aliasing properties in some cases.
4113 * For example if 2 tasks are alternately allocating
4114 * batches of pages, one task can end up with a lot
4115 * of pages of one half of the possible page colors
4116 * and the other with pages of the other colors.
4118 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4123 /* The deferral and batching of frees should be suppressed under NOMMU
4126 * The problem is that NOMMU needs to be able to allocate large chunks
4127 * of contiguous memory as there's no hardware page translation to
4128 * assemble apparent contiguous memory from discontiguous pages.
4130 * Queueing large contiguous runs of pages for batching, however,
4131 * causes the pages to actually be freed in smaller chunks. As there
4132 * can be a significant delay between the individual batches being
4133 * recycled, this leads to the once large chunks of space being
4134 * fragmented and becoming unavailable for high-order allocations.
4141 * pcp->high and pcp->batch values are related and dependent on one another:
4142 * ->batch must never be higher then ->high.
4143 * The following function updates them in a safe manner without read side
4146 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4147 * those fields changing asynchronously (acording the the above rule).
4149 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4150 * outside of boot time (or some other assurance that no concurrent updaters
4153 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4154 unsigned long batch)
4156 /* start with a fail safe value for batch */
4160 /* Update high, then batch, in order */
4167 /* a companion to pageset_set_high() */
4168 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4170 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4173 static void pageset_init(struct per_cpu_pageset *p)
4175 struct per_cpu_pages *pcp;
4178 memset(p, 0, sizeof(*p));
4182 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4183 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4186 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4189 pageset_set_batch(p, batch);
4193 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4194 * to the value high for the pageset p.
4196 static void pageset_set_high(struct per_cpu_pageset *p,
4199 unsigned long batch = max(1UL, high / 4);
4200 if ((high / 4) > (PAGE_SHIFT * 8))
4201 batch = PAGE_SHIFT * 8;
4203 pageset_update(&p->pcp, high, batch);
4206 static void __meminit pageset_set_high_and_batch(struct zone *zone,
4207 struct per_cpu_pageset *pcp)
4209 if (percpu_pagelist_fraction)
4210 pageset_set_high(pcp,
4211 (zone->managed_pages /
4212 percpu_pagelist_fraction));
4214 pageset_set_batch(pcp, zone_batchsize(zone));
4217 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4219 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4222 pageset_set_high_and_batch(zone, pcp);
4225 static void __meminit setup_zone_pageset(struct zone *zone)
4228 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4229 for_each_possible_cpu(cpu)
4230 zone_pageset_init(zone, cpu);
4234 * Allocate per cpu pagesets and initialize them.
4235 * Before this call only boot pagesets were available.
4237 void __init setup_per_cpu_pageset(void)
4241 for_each_populated_zone(zone)
4242 setup_zone_pageset(zone);
4245 static noinline __init_refok
4246 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4252 * The per-page waitqueue mechanism uses hashed waitqueues
4255 zone->wait_table_hash_nr_entries =
4256 wait_table_hash_nr_entries(zone_size_pages);
4257 zone->wait_table_bits =
4258 wait_table_bits(zone->wait_table_hash_nr_entries);
4259 alloc_size = zone->wait_table_hash_nr_entries
4260 * sizeof(wait_queue_head_t);
4262 if (!slab_is_available()) {
4263 zone->wait_table = (wait_queue_head_t *)
4264 memblock_virt_alloc_node_nopanic(
4265 alloc_size, zone->zone_pgdat->node_id);
4268 * This case means that a zone whose size was 0 gets new memory
4269 * via memory hot-add.
4270 * But it may be the case that a new node was hot-added. In
4271 * this case vmalloc() will not be able to use this new node's
4272 * memory - this wait_table must be initialized to use this new
4273 * node itself as well.
4274 * To use this new node's memory, further consideration will be
4277 zone->wait_table = vmalloc(alloc_size);
4279 if (!zone->wait_table)
4282 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4283 init_waitqueue_head(zone->wait_table + i);
4288 static __meminit void zone_pcp_init(struct zone *zone)
4291 * per cpu subsystem is not up at this point. The following code
4292 * relies on the ability of the linker to provide the
4293 * offset of a (static) per cpu variable into the per cpu area.
4295 zone->pageset = &boot_pageset;
4297 if (populated_zone(zone))
4298 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4299 zone->name, zone->present_pages,
4300 zone_batchsize(zone));
4303 int __meminit init_currently_empty_zone(struct zone *zone,
4304 unsigned long zone_start_pfn,
4306 enum memmap_context context)
4308 struct pglist_data *pgdat = zone->zone_pgdat;
4310 ret = zone_wait_table_init(zone, size);
4313 pgdat->nr_zones = zone_idx(zone) + 1;
4315 zone->zone_start_pfn = zone_start_pfn;
4317 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4318 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4320 (unsigned long)zone_idx(zone),
4321 zone_start_pfn, (zone_start_pfn + size));
4323 zone_init_free_lists(zone);
4328 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4329 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4331 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4332 * Architectures may implement their own version but if add_active_range()
4333 * was used and there are no special requirements, this is a convenient
4336 int __meminit __early_pfn_to_nid(unsigned long pfn)
4338 unsigned long start_pfn, end_pfn;
4341 * NOTE: The following SMP-unsafe globals are only used early in boot
4342 * when the kernel is running single-threaded.
4344 static unsigned long __meminitdata last_start_pfn, last_end_pfn;
4345 static int __meminitdata last_nid;
4347 if (last_start_pfn <= pfn && pfn < last_end_pfn)
4350 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4352 last_start_pfn = start_pfn;
4353 last_end_pfn = end_pfn;
4359 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4361 int __meminit early_pfn_to_nid(unsigned long pfn)
4365 nid = __early_pfn_to_nid(pfn);
4368 /* just returns 0 */
4372 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4373 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4377 nid = __early_pfn_to_nid(pfn);
4378 if (nid >= 0 && nid != node)
4385 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4386 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4387 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4389 * If an architecture guarantees that all ranges registered with
4390 * add_active_ranges() contain no holes and may be freed, this
4391 * this function may be used instead of calling memblock_free_early_nid()
4394 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4396 unsigned long start_pfn, end_pfn;
4399 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4400 start_pfn = min(start_pfn, max_low_pfn);
4401 end_pfn = min(end_pfn, max_low_pfn);
4403 if (start_pfn < end_pfn)
4404 memblock_free_early_nid(PFN_PHYS(start_pfn),
4405 (end_pfn - start_pfn) << PAGE_SHIFT,
4411 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4412 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4414 * If an architecture guarantees that all ranges registered with
4415 * add_active_ranges() contain no holes and may be freed, this
4416 * function may be used instead of calling memory_present() manually.
4418 void __init sparse_memory_present_with_active_regions(int nid)
4420 unsigned long start_pfn, end_pfn;
4423 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4424 memory_present(this_nid, start_pfn, end_pfn);
4428 * get_pfn_range_for_nid - Return the start and end page frames for a node
4429 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4430 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4431 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4433 * It returns the start and end page frame of a node based on information
4434 * provided by an arch calling add_active_range(). If called for a node
4435 * with no available memory, a warning is printed and the start and end
4438 void __meminit get_pfn_range_for_nid(unsigned int nid,
4439 unsigned long *start_pfn, unsigned long *end_pfn)
4441 unsigned long this_start_pfn, this_end_pfn;
4447 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
4448 *start_pfn = min(*start_pfn, this_start_pfn);
4449 *end_pfn = max(*end_pfn, this_end_pfn);
4452 if (*start_pfn == -1UL)
4457 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4458 * assumption is made that zones within a node are ordered in monotonic
4459 * increasing memory addresses so that the "highest" populated zone is used
4461 static void __init find_usable_zone_for_movable(void)
4464 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4465 if (zone_index == ZONE_MOVABLE)
4468 if (arch_zone_highest_possible_pfn[zone_index] >
4469 arch_zone_lowest_possible_pfn[zone_index])
4473 VM_BUG_ON(zone_index == -1);
4474 movable_zone = zone_index;
4478 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4479 * because it is sized independent of architecture. Unlike the other zones,
4480 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4481 * in each node depending on the size of each node and how evenly kernelcore
4482 * is distributed. This helper function adjusts the zone ranges
4483 * provided by the architecture for a given node by using the end of the
4484 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4485 * zones within a node are in order of monotonic increases memory addresses
4487 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4488 unsigned long zone_type,
4489 unsigned long node_start_pfn,
4490 unsigned long node_end_pfn,
4491 unsigned long *zone_start_pfn,
4492 unsigned long *zone_end_pfn)
4494 /* Only adjust if ZONE_MOVABLE is on this node */
4495 if (zone_movable_pfn[nid]) {
4496 /* Size ZONE_MOVABLE */
4497 if (zone_type == ZONE_MOVABLE) {
4498 *zone_start_pfn = zone_movable_pfn[nid];
4499 *zone_end_pfn = min(node_end_pfn,
4500 arch_zone_highest_possible_pfn[movable_zone]);
4502 /* Adjust for ZONE_MOVABLE starting within this range */
4503 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4504 *zone_end_pfn > zone_movable_pfn[nid]) {
4505 *zone_end_pfn = zone_movable_pfn[nid];
4507 /* Check if this whole range is within ZONE_MOVABLE */
4508 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4509 *zone_start_pfn = *zone_end_pfn;
4514 * Return the number of pages a zone spans in a node, including holes
4515 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4517 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4518 unsigned long zone_type,
4519 unsigned long node_start_pfn,
4520 unsigned long node_end_pfn,
4521 unsigned long *ignored)
4523 unsigned long zone_start_pfn, zone_end_pfn;
4525 /* Get the start and end of the zone */
4526 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4527 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4528 adjust_zone_range_for_zone_movable(nid, zone_type,
4529 node_start_pfn, node_end_pfn,
4530 &zone_start_pfn, &zone_end_pfn);
4532 /* Check that this node has pages within the zone's required range */
4533 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4536 /* Move the zone boundaries inside the node if necessary */
4537 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4538 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4540 /* Return the spanned pages */
4541 return zone_end_pfn - zone_start_pfn;
4545 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4546 * then all holes in the requested range will be accounted for.
4548 unsigned long __meminit __absent_pages_in_range(int nid,
4549 unsigned long range_start_pfn,
4550 unsigned long range_end_pfn)
4552 unsigned long nr_absent = range_end_pfn - range_start_pfn;
4553 unsigned long start_pfn, end_pfn;
4556 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4557 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4558 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4559 nr_absent -= end_pfn - start_pfn;
4565 * absent_pages_in_range - Return number of page frames in holes within a range
4566 * @start_pfn: The start PFN to start searching for holes
4567 * @end_pfn: The end PFN to stop searching for holes
4569 * It returns the number of pages frames in memory holes within a range.
4571 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4572 unsigned long end_pfn)
4574 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4577 /* Return the number of page frames in holes in a zone on a node */
4578 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4579 unsigned long zone_type,
4580 unsigned long node_start_pfn,
4581 unsigned long node_end_pfn,
4582 unsigned long *ignored)
4584 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4585 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4586 unsigned long zone_start_pfn, zone_end_pfn;
4588 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4589 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4591 adjust_zone_range_for_zone_movable(nid, zone_type,
4592 node_start_pfn, node_end_pfn,
4593 &zone_start_pfn, &zone_end_pfn);
4594 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4597 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4598 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4599 unsigned long zone_type,
4600 unsigned long node_start_pfn,
4601 unsigned long node_end_pfn,
4602 unsigned long *zones_size)
4604 return zones_size[zone_type];
4607 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4608 unsigned long zone_type,
4609 unsigned long node_start_pfn,
4610 unsigned long node_end_pfn,
4611 unsigned long *zholes_size)
4616 return zholes_size[zone_type];
4619 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4621 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4622 unsigned long node_start_pfn,
4623 unsigned long node_end_pfn,
4624 unsigned long *zones_size,
4625 unsigned long *zholes_size)
4627 unsigned long realtotalpages, totalpages = 0;
4630 for (i = 0; i < MAX_NR_ZONES; i++)
4631 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4635 pgdat->node_spanned_pages = totalpages;
4637 realtotalpages = totalpages;
4638 for (i = 0; i < MAX_NR_ZONES; i++)
4640 zone_absent_pages_in_node(pgdat->node_id, i,
4641 node_start_pfn, node_end_pfn,
4643 pgdat->node_present_pages = realtotalpages;
4644 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4648 #ifndef CONFIG_SPARSEMEM
4650 * Calculate the size of the zone->blockflags rounded to an unsigned long
4651 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4652 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4653 * round what is now in bits to nearest long in bits, then return it in
4656 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4658 unsigned long usemapsize;
4660 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4661 usemapsize = roundup(zonesize, pageblock_nr_pages);
4662 usemapsize = usemapsize >> pageblock_order;
4663 usemapsize *= NR_PAGEBLOCK_BITS;
4664 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4666 return usemapsize / 8;
4669 static void __init setup_usemap(struct pglist_data *pgdat,
4671 unsigned long zone_start_pfn,
4672 unsigned long zonesize)
4674 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4675 zone->pageblock_flags = NULL;
4677 zone->pageblock_flags =
4678 memblock_virt_alloc_node_nopanic(usemapsize,
4682 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4683 unsigned long zone_start_pfn, unsigned long zonesize) {}
4684 #endif /* CONFIG_SPARSEMEM */
4686 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4688 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4689 void __paginginit set_pageblock_order(void)
4693 /* Check that pageblock_nr_pages has not already been setup */
4694 if (pageblock_order)
4697 if (HPAGE_SHIFT > PAGE_SHIFT)
4698 order = HUGETLB_PAGE_ORDER;
4700 order = MAX_ORDER - 1;
4703 * Assume the largest contiguous order of interest is a huge page.
4704 * This value may be variable depending on boot parameters on IA64 and
4707 pageblock_order = order;
4709 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4712 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4713 * is unused as pageblock_order is set at compile-time. See
4714 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4717 void __paginginit set_pageblock_order(void)
4721 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4723 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
4724 unsigned long present_pages)
4726 unsigned long pages = spanned_pages;
4729 * Provide a more accurate estimation if there are holes within
4730 * the zone and SPARSEMEM is in use. If there are holes within the
4731 * zone, each populated memory region may cost us one or two extra
4732 * memmap pages due to alignment because memmap pages for each
4733 * populated regions may not naturally algined on page boundary.
4734 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4736 if (spanned_pages > present_pages + (present_pages >> 4) &&
4737 IS_ENABLED(CONFIG_SPARSEMEM))
4738 pages = present_pages;
4740 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
4744 * Set up the zone data structures:
4745 * - mark all pages reserved
4746 * - mark all memory queues empty
4747 * - clear the memory bitmaps
4749 * NOTE: pgdat should get zeroed by caller.
4751 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4752 unsigned long node_start_pfn, unsigned long node_end_pfn,
4753 unsigned long *zones_size, unsigned long *zholes_size)
4756 int nid = pgdat->node_id;
4757 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4760 pgdat_resize_init(pgdat);
4761 #ifdef CONFIG_NUMA_BALANCING
4762 spin_lock_init(&pgdat->numabalancing_migrate_lock);
4763 pgdat->numabalancing_migrate_nr_pages = 0;
4764 pgdat->numabalancing_migrate_next_window = jiffies;
4766 init_waitqueue_head(&pgdat->kswapd_wait);
4767 init_waitqueue_head(&pgdat->pfmemalloc_wait);
4768 pgdat_page_cgroup_init(pgdat);
4770 for (j = 0; j < MAX_NR_ZONES; j++) {
4771 struct zone *zone = pgdat->node_zones + j;
4772 unsigned long size, realsize, freesize, memmap_pages;
4774 size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
4775 node_end_pfn, zones_size);
4776 realsize = freesize = size - zone_absent_pages_in_node(nid, j,
4782 * Adjust freesize so that it accounts for how much memory
4783 * is used by this zone for memmap. This affects the watermark
4784 * and per-cpu initialisations
4786 memmap_pages = calc_memmap_size(size, realsize);
4787 if (freesize >= memmap_pages) {
4788 freesize -= memmap_pages;
4791 " %s zone: %lu pages used for memmap\n",
4792 zone_names[j], memmap_pages);
4795 " %s zone: %lu pages exceeds freesize %lu\n",
4796 zone_names[j], memmap_pages, freesize);
4798 /* Account for reserved pages */
4799 if (j == 0 && freesize > dma_reserve) {
4800 freesize -= dma_reserve;
4801 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4802 zone_names[0], dma_reserve);
4805 if (!is_highmem_idx(j))
4806 nr_kernel_pages += freesize;
4807 /* Charge for highmem memmap if there are enough kernel pages */
4808 else if (nr_kernel_pages > memmap_pages * 2)
4809 nr_kernel_pages -= memmap_pages;
4810 nr_all_pages += freesize;
4812 zone->spanned_pages = size;
4813 zone->present_pages = realsize;
4815 * Set an approximate value for lowmem here, it will be adjusted
4816 * when the bootmem allocator frees pages into the buddy system.
4817 * And all highmem pages will be managed by the buddy system.
4819 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
4822 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4824 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4826 zone->name = zone_names[j];
4827 spin_lock_init(&zone->lock);
4828 spin_lock_init(&zone->lru_lock);
4829 zone_seqlock_init(zone);
4830 zone->zone_pgdat = pgdat;
4831 zone_pcp_init(zone);
4833 /* For bootup, initialized properly in watermark setup */
4834 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
4836 lruvec_init(&zone->lruvec);
4840 set_pageblock_order();
4841 setup_usemap(pgdat, zone, zone_start_pfn, size);
4842 ret = init_currently_empty_zone(zone, zone_start_pfn,
4843 size, MEMMAP_EARLY);
4845 memmap_init(size, nid, j, zone_start_pfn);
4846 zone_start_pfn += size;
4850 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4852 /* Skip empty nodes */
4853 if (!pgdat->node_spanned_pages)
4856 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4857 /* ia64 gets its own node_mem_map, before this, without bootmem */
4858 if (!pgdat->node_mem_map) {
4859 unsigned long size, start, end;
4863 * The zone's endpoints aren't required to be MAX_ORDER
4864 * aligned but the node_mem_map endpoints must be in order
4865 * for the buddy allocator to function correctly.
4867 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4868 end = pgdat_end_pfn(pgdat);
4869 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4870 size = (end - start) * sizeof(struct page);
4871 map = alloc_remap(pgdat->node_id, size);
4873 map = memblock_virt_alloc_node_nopanic(size,
4875 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4877 #ifndef CONFIG_NEED_MULTIPLE_NODES
4879 * With no DISCONTIG, the global mem_map is just set as node 0's
4881 if (pgdat == NODE_DATA(0)) {
4882 mem_map = NODE_DATA(0)->node_mem_map;
4883 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4884 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4885 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4886 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4889 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4892 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4893 unsigned long node_start_pfn, unsigned long *zholes_size)
4895 pg_data_t *pgdat = NODE_DATA(nid);
4896 unsigned long start_pfn = 0;
4897 unsigned long end_pfn = 0;
4899 /* pg_data_t should be reset to zero when it's allocated */
4900 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4902 pgdat->node_id = nid;
4903 pgdat->node_start_pfn = node_start_pfn;
4904 init_zone_allows_reclaim(nid);
4905 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4906 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
4908 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
4909 zones_size, zholes_size);
4911 alloc_node_mem_map(pgdat);
4912 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4913 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4914 nid, (unsigned long)pgdat,
4915 (unsigned long)pgdat->node_mem_map);
4918 free_area_init_core(pgdat, start_pfn, end_pfn,
4919 zones_size, zholes_size);
4922 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4924 #if MAX_NUMNODES > 1
4926 * Figure out the number of possible node ids.
4928 void __init setup_nr_node_ids(void)
4931 unsigned int highest = 0;
4933 for_each_node_mask(node, node_possible_map)
4935 nr_node_ids = highest + 1;
4940 * node_map_pfn_alignment - determine the maximum internode alignment
4942 * This function should be called after node map is populated and sorted.
4943 * It calculates the maximum power of two alignment which can distinguish
4946 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4947 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4948 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4949 * shifted, 1GiB is enough and this function will indicate so.
4951 * This is used to test whether pfn -> nid mapping of the chosen memory
4952 * model has fine enough granularity to avoid incorrect mapping for the
4953 * populated node map.
4955 * Returns the determined alignment in pfn's. 0 if there is no alignment
4956 * requirement (single node).
4958 unsigned long __init node_map_pfn_alignment(void)
4960 unsigned long accl_mask = 0, last_end = 0;
4961 unsigned long start, end, mask;
4965 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
4966 if (!start || last_nid < 0 || last_nid == nid) {
4973 * Start with a mask granular enough to pin-point to the
4974 * start pfn and tick off bits one-by-one until it becomes
4975 * too coarse to separate the current node from the last.
4977 mask = ~((1 << __ffs(start)) - 1);
4978 while (mask && last_end <= (start & (mask << 1)))
4981 /* accumulate all internode masks */
4985 /* convert mask to number of pages */
4986 return ~accl_mask + 1;
4989 /* Find the lowest pfn for a node */
4990 static unsigned long __init find_min_pfn_for_node(int nid)
4992 unsigned long min_pfn = ULONG_MAX;
4993 unsigned long start_pfn;
4996 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
4997 min_pfn = min(min_pfn, start_pfn);
4999 if (min_pfn == ULONG_MAX) {
5001 "Could not find start_pfn for node %d\n", nid);
5009 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5011 * It returns the minimum PFN based on information provided via
5012 * add_active_range().
5014 unsigned long __init find_min_pfn_with_active_regions(void)
5016 return find_min_pfn_for_node(MAX_NUMNODES);
5020 * early_calculate_totalpages()
5021 * Sum pages in active regions for movable zone.
5022 * Populate N_MEMORY for calculating usable_nodes.
5024 static unsigned long __init early_calculate_totalpages(void)
5026 unsigned long totalpages = 0;
5027 unsigned long start_pfn, end_pfn;
5030 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5031 unsigned long pages = end_pfn - start_pfn;
5033 totalpages += pages;
5035 node_set_state(nid, N_MEMORY);
5041 * Find the PFN the Movable zone begins in each node. Kernel memory
5042 * is spread evenly between nodes as long as the nodes have enough
5043 * memory. When they don't, some nodes will have more kernelcore than
5046 static void __init find_zone_movable_pfns_for_nodes(void)
5049 unsigned long usable_startpfn;
5050 unsigned long kernelcore_node, kernelcore_remaining;
5051 /* save the state before borrow the nodemask */
5052 nodemask_t saved_node_state = node_states[N_MEMORY];
5053 unsigned long totalpages = early_calculate_totalpages();
5054 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5055 struct memblock_type *type = &memblock.memory;
5057 /* Need to find movable_zone earlier when movable_node is specified. */
5058 find_usable_zone_for_movable();
5061 * If movable_node is specified, ignore kernelcore and movablecore
5064 if (movable_node_is_enabled()) {
5065 for (i = 0; i < type->cnt; i++) {
5066 if (!memblock_is_hotpluggable(&type->regions[i]))
5069 nid = type->regions[i].nid;
5071 usable_startpfn = PFN_DOWN(type->regions[i].base);
5072 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5073 min(usable_startpfn, zone_movable_pfn[nid]) :
5081 * If movablecore=nn[KMG] was specified, calculate what size of
5082 * kernelcore that corresponds so that memory usable for
5083 * any allocation type is evenly spread. If both kernelcore
5084 * and movablecore are specified, then the value of kernelcore
5085 * will be used for required_kernelcore if it's greater than
5086 * what movablecore would have allowed.
5088 if (required_movablecore) {
5089 unsigned long corepages;
5092 * Round-up so that ZONE_MOVABLE is at least as large as what
5093 * was requested by the user
5095 required_movablecore =
5096 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5097 corepages = totalpages - required_movablecore;
5099 required_kernelcore = max(required_kernelcore, corepages);
5102 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5103 if (!required_kernelcore)
5106 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5107 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5110 /* Spread kernelcore memory as evenly as possible throughout nodes */
5111 kernelcore_node = required_kernelcore / usable_nodes;
5112 for_each_node_state(nid, N_MEMORY) {
5113 unsigned long start_pfn, end_pfn;
5116 * Recalculate kernelcore_node if the division per node
5117 * now exceeds what is necessary to satisfy the requested
5118 * amount of memory for the kernel
5120 if (required_kernelcore < kernelcore_node)
5121 kernelcore_node = required_kernelcore / usable_nodes;
5124 * As the map is walked, we track how much memory is usable
5125 * by the kernel using kernelcore_remaining. When it is
5126 * 0, the rest of the node is usable by ZONE_MOVABLE
5128 kernelcore_remaining = kernelcore_node;
5130 /* Go through each range of PFNs within this node */
5131 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5132 unsigned long size_pages;
5134 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5135 if (start_pfn >= end_pfn)
5138 /* Account for what is only usable for kernelcore */
5139 if (start_pfn < usable_startpfn) {
5140 unsigned long kernel_pages;
5141 kernel_pages = min(end_pfn, usable_startpfn)
5144 kernelcore_remaining -= min(kernel_pages,
5145 kernelcore_remaining);
5146 required_kernelcore -= min(kernel_pages,
5147 required_kernelcore);
5149 /* Continue if range is now fully accounted */
5150 if (end_pfn <= usable_startpfn) {
5153 * Push zone_movable_pfn to the end so
5154 * that if we have to rebalance
5155 * kernelcore across nodes, we will
5156 * not double account here
5158 zone_movable_pfn[nid] = end_pfn;
5161 start_pfn = usable_startpfn;
5165 * The usable PFN range for ZONE_MOVABLE is from
5166 * start_pfn->end_pfn. Calculate size_pages as the
5167 * number of pages used as kernelcore
5169 size_pages = end_pfn - start_pfn;
5170 if (size_pages > kernelcore_remaining)
5171 size_pages = kernelcore_remaining;
5172 zone_movable_pfn[nid] = start_pfn + size_pages;
5175 * Some kernelcore has been met, update counts and
5176 * break if the kernelcore for this node has been
5179 required_kernelcore -= min(required_kernelcore,
5181 kernelcore_remaining -= size_pages;
5182 if (!kernelcore_remaining)
5188 * If there is still required_kernelcore, we do another pass with one
5189 * less node in the count. This will push zone_movable_pfn[nid] further
5190 * along on the nodes that still have memory until kernelcore is
5194 if (usable_nodes && required_kernelcore > usable_nodes)
5198 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5199 for (nid = 0; nid < MAX_NUMNODES; nid++)
5200 zone_movable_pfn[nid] =
5201 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5204 /* restore the node_state */
5205 node_states[N_MEMORY] = saved_node_state;
5208 /* Any regular or high memory on that node ? */
5209 static void check_for_memory(pg_data_t *pgdat, int nid)
5211 enum zone_type zone_type;
5213 if (N_MEMORY == N_NORMAL_MEMORY)
5216 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5217 struct zone *zone = &pgdat->node_zones[zone_type];
5218 if (populated_zone(zone)) {
5219 node_set_state(nid, N_HIGH_MEMORY);
5220 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5221 zone_type <= ZONE_NORMAL)
5222 node_set_state(nid, N_NORMAL_MEMORY);
5229 * free_area_init_nodes - Initialise all pg_data_t and zone data
5230 * @max_zone_pfn: an array of max PFNs for each zone
5232 * This will call free_area_init_node() for each active node in the system.
5233 * Using the page ranges provided by add_active_range(), the size of each
5234 * zone in each node and their holes is calculated. If the maximum PFN
5235 * between two adjacent zones match, it is assumed that the zone is empty.
5236 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5237 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5238 * starts where the previous one ended. For example, ZONE_DMA32 starts
5239 * at arch_max_dma_pfn.
5241 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5243 unsigned long start_pfn, end_pfn;
5246 /* Record where the zone boundaries are */
5247 memset(arch_zone_lowest_possible_pfn, 0,
5248 sizeof(arch_zone_lowest_possible_pfn));
5249 memset(arch_zone_highest_possible_pfn, 0,
5250 sizeof(arch_zone_highest_possible_pfn));
5251 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5252 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5253 for (i = 1; i < MAX_NR_ZONES; i++) {
5254 if (i == ZONE_MOVABLE)
5256 arch_zone_lowest_possible_pfn[i] =
5257 arch_zone_highest_possible_pfn[i-1];
5258 arch_zone_highest_possible_pfn[i] =
5259 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5261 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5262 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5264 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5265 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5266 find_zone_movable_pfns_for_nodes();
5268 /* Print out the zone ranges */
5269 printk("Zone ranges:\n");
5270 for (i = 0; i < MAX_NR_ZONES; i++) {
5271 if (i == ZONE_MOVABLE)
5273 printk(KERN_CONT " %-8s ", zone_names[i]);
5274 if (arch_zone_lowest_possible_pfn[i] ==
5275 arch_zone_highest_possible_pfn[i])
5276 printk(KERN_CONT "empty\n");
5278 printk(KERN_CONT "[mem %0#10lx-%0#10lx]\n",
5279 arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT,
5280 (arch_zone_highest_possible_pfn[i]
5281 << PAGE_SHIFT) - 1);
5284 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5285 printk("Movable zone start for each node\n");
5286 for (i = 0; i < MAX_NUMNODES; i++) {
5287 if (zone_movable_pfn[i])
5288 printk(" Node %d: %#010lx\n", i,
5289 zone_movable_pfn[i] << PAGE_SHIFT);
5292 /* Print out the early node map */
5293 printk("Early memory node ranges\n");
5294 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5295 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid,
5296 start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
5298 /* Initialise every node */
5299 mminit_verify_pageflags_layout();
5300 setup_nr_node_ids();
5301 for_each_online_node(nid) {
5302 pg_data_t *pgdat = NODE_DATA(nid);
5303 free_area_init_node(nid, NULL,
5304 find_min_pfn_for_node(nid), NULL);
5306 /* Any memory on that node */
5307 if (pgdat->node_present_pages)
5308 node_set_state(nid, N_MEMORY);
5309 check_for_memory(pgdat, nid);
5313 static int __init cmdline_parse_core(char *p, unsigned long *core)
5315 unsigned long long coremem;
5319 coremem = memparse(p, &p);
5320 *core = coremem >> PAGE_SHIFT;
5322 /* Paranoid check that UL is enough for the coremem value */
5323 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5329 * kernelcore=size sets the amount of memory for use for allocations that
5330 * cannot be reclaimed or migrated.
5332 static int __init cmdline_parse_kernelcore(char *p)
5334 return cmdline_parse_core(p, &required_kernelcore);
5338 * movablecore=size sets the amount of memory for use for allocations that
5339 * can be reclaimed or migrated.
5341 static int __init cmdline_parse_movablecore(char *p)
5343 return cmdline_parse_core(p, &required_movablecore);
5346 early_param("kernelcore", cmdline_parse_kernelcore);
5347 early_param("movablecore", cmdline_parse_movablecore);
5349 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5351 void adjust_managed_page_count(struct page *page, long count)
5353 spin_lock(&managed_page_count_lock);
5354 page_zone(page)->managed_pages += count;
5355 totalram_pages += count;
5356 #ifdef CONFIG_HIGHMEM
5357 if (PageHighMem(page))
5358 totalhigh_pages += count;
5360 spin_unlock(&managed_page_count_lock);
5362 EXPORT_SYMBOL(adjust_managed_page_count);
5364 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5367 unsigned long pages = 0;
5369 start = (void *)PAGE_ALIGN((unsigned long)start);
5370 end = (void *)((unsigned long)end & PAGE_MASK);
5371 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5372 if ((unsigned int)poison <= 0xFF)
5373 memset(pos, poison, PAGE_SIZE);
5374 free_reserved_page(virt_to_page(pos));
5378 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5379 s, pages << (PAGE_SHIFT - 10), start, end);
5383 EXPORT_SYMBOL(free_reserved_area);
5385 #ifdef CONFIG_HIGHMEM
5386 void free_highmem_page(struct page *page)
5388 __free_reserved_page(page);
5390 page_zone(page)->managed_pages++;
5396 void __init mem_init_print_info(const char *str)
5398 unsigned long physpages, codesize, datasize, rosize, bss_size;
5399 unsigned long init_code_size, init_data_size;
5401 physpages = get_num_physpages();
5402 codesize = _etext - _stext;
5403 datasize = _edata - _sdata;
5404 rosize = __end_rodata - __start_rodata;
5405 bss_size = __bss_stop - __bss_start;
5406 init_data_size = __init_end - __init_begin;
5407 init_code_size = _einittext - _sinittext;
5410 * Detect special cases and adjust section sizes accordingly:
5411 * 1) .init.* may be embedded into .data sections
5412 * 2) .init.text.* may be out of [__init_begin, __init_end],
5413 * please refer to arch/tile/kernel/vmlinux.lds.S.
5414 * 3) .rodata.* may be embedded into .text or .data sections.
5416 #define adj_init_size(start, end, size, pos, adj) \
5418 if (start <= pos && pos < end && size > adj) \
5422 adj_init_size(__init_begin, __init_end, init_data_size,
5423 _sinittext, init_code_size);
5424 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
5425 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
5426 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
5427 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
5429 #undef adj_init_size
5431 printk("Memory: %luK/%luK available "
5432 "(%luK kernel code, %luK rwdata, %luK rodata, "
5433 "%luK init, %luK bss, %luK reserved"
5434 #ifdef CONFIG_HIGHMEM
5438 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
5439 codesize >> 10, datasize >> 10, rosize >> 10,
5440 (init_data_size + init_code_size) >> 10, bss_size >> 10,
5441 (physpages - totalram_pages) << (PAGE_SHIFT-10),
5442 #ifdef CONFIG_HIGHMEM
5443 totalhigh_pages << (PAGE_SHIFT-10),
5445 str ? ", " : "", str ? str : "");
5449 * set_dma_reserve - set the specified number of pages reserved in the first zone
5450 * @new_dma_reserve: The number of pages to mark reserved
5452 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5453 * In the DMA zone, a significant percentage may be consumed by kernel image
5454 * and other unfreeable allocations which can skew the watermarks badly. This
5455 * function may optionally be used to account for unfreeable pages in the
5456 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5457 * smaller per-cpu batchsize.
5459 void __init set_dma_reserve(unsigned long new_dma_reserve)
5461 dma_reserve = new_dma_reserve;
5464 void __init free_area_init(unsigned long *zones_size)
5466 free_area_init_node(0, zones_size,
5467 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5470 static int page_alloc_cpu_notify(struct notifier_block *self,
5471 unsigned long action, void *hcpu)
5473 int cpu = (unsigned long)hcpu;
5475 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5476 lru_add_drain_cpu(cpu);
5480 * Spill the event counters of the dead processor
5481 * into the current processors event counters.
5482 * This artificially elevates the count of the current
5485 vm_events_fold_cpu(cpu);
5488 * Zero the differential counters of the dead processor
5489 * so that the vm statistics are consistent.
5491 * This is only okay since the processor is dead and cannot
5492 * race with what we are doing.
5494 cpu_vm_stats_fold(cpu);
5499 void __init page_alloc_init(void)
5501 hotcpu_notifier(page_alloc_cpu_notify, 0);
5505 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5506 * or min_free_kbytes changes.
5508 static void calculate_totalreserve_pages(void)
5510 struct pglist_data *pgdat;
5511 unsigned long reserve_pages = 0;
5512 enum zone_type i, j;
5514 for_each_online_pgdat(pgdat) {
5515 for (i = 0; i < MAX_NR_ZONES; i++) {
5516 struct zone *zone = pgdat->node_zones + i;
5517 unsigned long max = 0;
5519 /* Find valid and maximum lowmem_reserve in the zone */
5520 for (j = i; j < MAX_NR_ZONES; j++) {
5521 if (zone->lowmem_reserve[j] > max)
5522 max = zone->lowmem_reserve[j];
5525 /* we treat the high watermark as reserved pages. */
5526 max += high_wmark_pages(zone);
5528 if (max > zone->managed_pages)
5529 max = zone->managed_pages;
5530 reserve_pages += max;
5532 * Lowmem reserves are not available to
5533 * GFP_HIGHUSER page cache allocations and
5534 * kswapd tries to balance zones to their high
5535 * watermark. As a result, neither should be
5536 * regarded as dirtyable memory, to prevent a
5537 * situation where reclaim has to clean pages
5538 * in order to balance the zones.
5540 zone->dirty_balance_reserve = max;
5543 dirty_balance_reserve = reserve_pages;
5544 totalreserve_pages = reserve_pages;
5548 * setup_per_zone_lowmem_reserve - called whenever
5549 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5550 * has a correct pages reserved value, so an adequate number of
5551 * pages are left in the zone after a successful __alloc_pages().
5553 static void setup_per_zone_lowmem_reserve(void)
5555 struct pglist_data *pgdat;
5556 enum zone_type j, idx;
5558 for_each_online_pgdat(pgdat) {
5559 for (j = 0; j < MAX_NR_ZONES; j++) {
5560 struct zone *zone = pgdat->node_zones + j;
5561 unsigned long managed_pages = zone->managed_pages;
5563 zone->lowmem_reserve[j] = 0;
5567 struct zone *lower_zone;
5571 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5572 sysctl_lowmem_reserve_ratio[idx] = 1;
5574 lower_zone = pgdat->node_zones + idx;
5575 lower_zone->lowmem_reserve[j] = managed_pages /
5576 sysctl_lowmem_reserve_ratio[idx];
5577 managed_pages += lower_zone->managed_pages;
5582 /* update totalreserve_pages */
5583 calculate_totalreserve_pages();
5586 static void __setup_per_zone_wmarks(void)
5588 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5589 unsigned long lowmem_pages = 0;
5591 unsigned long flags;
5593 /* Calculate total number of !ZONE_HIGHMEM pages */
5594 for_each_zone(zone) {
5595 if (!is_highmem(zone))
5596 lowmem_pages += zone->managed_pages;
5599 for_each_zone(zone) {
5602 spin_lock_irqsave(&zone->lock, flags);
5603 tmp = (u64)pages_min * zone->managed_pages;
5604 do_div(tmp, lowmem_pages);
5605 if (is_highmem(zone)) {
5607 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5608 * need highmem pages, so cap pages_min to a small
5611 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5612 * deltas controls asynch page reclaim, and so should
5613 * not be capped for highmem.
5615 unsigned long min_pages;
5617 min_pages = zone->managed_pages / 1024;
5618 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
5619 zone->watermark[WMARK_MIN] = min_pages;
5622 * If it's a lowmem zone, reserve a number of pages
5623 * proportionate to the zone's size.
5625 zone->watermark[WMARK_MIN] = tmp;
5628 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5629 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5631 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
5632 high_wmark_pages(zone) -
5633 low_wmark_pages(zone) -
5634 zone_page_state(zone, NR_ALLOC_BATCH));
5636 setup_zone_migrate_reserve(zone);
5637 spin_unlock_irqrestore(&zone->lock, flags);
5640 /* update totalreserve_pages */
5641 calculate_totalreserve_pages();
5645 * setup_per_zone_wmarks - called when min_free_kbytes changes
5646 * or when memory is hot-{added|removed}
5648 * Ensures that the watermark[min,low,high] values for each zone are set
5649 * correctly with respect to min_free_kbytes.
5651 void setup_per_zone_wmarks(void)
5653 mutex_lock(&zonelists_mutex);
5654 __setup_per_zone_wmarks();
5655 mutex_unlock(&zonelists_mutex);
5659 * The inactive anon list should be small enough that the VM never has to
5660 * do too much work, but large enough that each inactive page has a chance
5661 * to be referenced again before it is swapped out.
5663 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5664 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5665 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5666 * the anonymous pages are kept on the inactive list.
5669 * memory ratio inactive anon
5670 * -------------------------------------
5679 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5681 unsigned int gb, ratio;
5683 /* Zone size in gigabytes */
5684 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
5686 ratio = int_sqrt(10 * gb);
5690 zone->inactive_ratio = ratio;
5693 static void __meminit setup_per_zone_inactive_ratio(void)
5698 calculate_zone_inactive_ratio(zone);
5702 * Initialise min_free_kbytes.
5704 * For small machines we want it small (128k min). For large machines
5705 * we want it large (64MB max). But it is not linear, because network
5706 * bandwidth does not increase linearly with machine size. We use
5708 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5709 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5725 int __meminit init_per_zone_wmark_min(void)
5727 unsigned long lowmem_kbytes;
5728 int new_min_free_kbytes;
5730 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5731 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5733 if (new_min_free_kbytes > user_min_free_kbytes) {
5734 min_free_kbytes = new_min_free_kbytes;
5735 if (min_free_kbytes < 128)
5736 min_free_kbytes = 128;
5737 if (min_free_kbytes > 65536)
5738 min_free_kbytes = 65536;
5740 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5741 new_min_free_kbytes, user_min_free_kbytes);
5743 setup_per_zone_wmarks();
5744 refresh_zone_stat_thresholds();
5745 setup_per_zone_lowmem_reserve();
5746 setup_per_zone_inactive_ratio();
5749 module_init(init_per_zone_wmark_min)
5752 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5753 * that we can call two helper functions whenever min_free_kbytes
5756 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
5757 void __user *buffer, size_t *length, loff_t *ppos)
5761 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5766 user_min_free_kbytes = min_free_kbytes;
5767 setup_per_zone_wmarks();
5773 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5774 void __user *buffer, size_t *length, loff_t *ppos)
5779 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5784 zone->min_unmapped_pages = (zone->managed_pages *
5785 sysctl_min_unmapped_ratio) / 100;
5789 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5790 void __user *buffer, size_t *length, loff_t *ppos)
5795 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5800 zone->min_slab_pages = (zone->managed_pages *
5801 sysctl_min_slab_ratio) / 100;
5807 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5808 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5809 * whenever sysctl_lowmem_reserve_ratio changes.
5811 * The reserve ratio obviously has absolutely no relation with the
5812 * minimum watermarks. The lowmem reserve ratio can only make sense
5813 * if in function of the boot time zone sizes.
5815 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5816 void __user *buffer, size_t *length, loff_t *ppos)
5818 proc_dointvec_minmax(table, write, buffer, length, ppos);
5819 setup_per_zone_lowmem_reserve();
5824 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5825 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5826 * pagelist can have before it gets flushed back to buddy allocator.
5828 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
5829 void __user *buffer, size_t *length, loff_t *ppos)
5835 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5836 if (!write || (ret < 0))
5839 mutex_lock(&pcp_batch_high_lock);
5840 for_each_populated_zone(zone) {
5842 high = zone->managed_pages / percpu_pagelist_fraction;
5843 for_each_possible_cpu(cpu)
5844 pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
5847 mutex_unlock(&pcp_batch_high_lock);
5851 int hashdist = HASHDIST_DEFAULT;
5854 static int __init set_hashdist(char *str)
5858 hashdist = simple_strtoul(str, &str, 0);
5861 __setup("hashdist=", set_hashdist);
5865 * allocate a large system hash table from bootmem
5866 * - it is assumed that the hash table must contain an exact power-of-2
5867 * quantity of entries
5868 * - limit is the number of hash buckets, not the total allocation size
5870 void *__init alloc_large_system_hash(const char *tablename,
5871 unsigned long bucketsize,
5872 unsigned long numentries,
5875 unsigned int *_hash_shift,
5876 unsigned int *_hash_mask,
5877 unsigned long low_limit,
5878 unsigned long high_limit)
5880 unsigned long long max = high_limit;
5881 unsigned long log2qty, size;
5884 /* allow the kernel cmdline to have a say */
5886 /* round applicable memory size up to nearest megabyte */
5887 numentries = nr_kernel_pages;
5889 /* It isn't necessary when PAGE_SIZE >= 1MB */
5890 if (PAGE_SHIFT < 20)
5891 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
5893 /* limit to 1 bucket per 2^scale bytes of low memory */
5894 if (scale > PAGE_SHIFT)
5895 numentries >>= (scale - PAGE_SHIFT);
5897 numentries <<= (PAGE_SHIFT - scale);
5899 /* Make sure we've got at least a 0-order allocation.. */
5900 if (unlikely(flags & HASH_SMALL)) {
5901 /* Makes no sense without HASH_EARLY */
5902 WARN_ON(!(flags & HASH_EARLY));
5903 if (!(numentries >> *_hash_shift)) {
5904 numentries = 1UL << *_hash_shift;
5905 BUG_ON(!numentries);
5907 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5908 numentries = PAGE_SIZE / bucketsize;
5910 numentries = roundup_pow_of_two(numentries);
5912 /* limit allocation size to 1/16 total memory by default */
5914 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5915 do_div(max, bucketsize);
5917 max = min(max, 0x80000000ULL);
5919 if (numentries < low_limit)
5920 numentries = low_limit;
5921 if (numentries > max)
5924 log2qty = ilog2(numentries);
5927 size = bucketsize << log2qty;
5928 if (flags & HASH_EARLY)
5929 table = memblock_virt_alloc_nopanic(size, 0);
5931 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
5934 * If bucketsize is not a power-of-two, we may free
5935 * some pages at the end of hash table which
5936 * alloc_pages_exact() automatically does
5938 if (get_order(size) < MAX_ORDER) {
5939 table = alloc_pages_exact(size, GFP_ATOMIC);
5940 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
5943 } while (!table && size > PAGE_SIZE && --log2qty);
5946 panic("Failed to allocate %s hash table\n", tablename);
5948 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
5951 ilog2(size) - PAGE_SHIFT,
5955 *_hash_shift = log2qty;
5957 *_hash_mask = (1 << log2qty) - 1;
5962 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5963 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
5966 #ifdef CONFIG_SPARSEMEM
5967 return __pfn_to_section(pfn)->pageblock_flags;
5969 return zone->pageblock_flags;
5970 #endif /* CONFIG_SPARSEMEM */
5973 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
5975 #ifdef CONFIG_SPARSEMEM
5976 pfn &= (PAGES_PER_SECTION-1);
5977 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5979 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
5980 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5981 #endif /* CONFIG_SPARSEMEM */
5985 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5986 * @page: The page within the block of interest
5987 * @start_bitidx: The first bit of interest to retrieve
5988 * @end_bitidx: The last bit of interest
5989 * returns pageblock_bits flags
5991 unsigned long get_pageblock_flags_group(struct page *page,
5992 int start_bitidx, int end_bitidx)
5995 unsigned long *bitmap;
5996 unsigned long pfn, bitidx;
5997 unsigned long flags = 0;
5998 unsigned long value = 1;
6000 zone = page_zone(page);
6001 pfn = page_to_pfn(page);
6002 bitmap = get_pageblock_bitmap(zone, pfn);
6003 bitidx = pfn_to_bitidx(zone, pfn);
6005 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
6006 if (test_bit(bitidx + start_bitidx, bitmap))
6013 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
6014 * @page: The page within the block of interest
6015 * @start_bitidx: The first bit of interest
6016 * @end_bitidx: The last bit of interest
6017 * @flags: The flags to set
6019 void set_pageblock_flags_group(struct page *page, unsigned long flags,
6020 int start_bitidx, int end_bitidx)
6023 unsigned long *bitmap;
6024 unsigned long pfn, bitidx;
6025 unsigned long value = 1;
6027 zone = page_zone(page);
6028 pfn = page_to_pfn(page);
6029 bitmap = get_pageblock_bitmap(zone, pfn);
6030 bitidx = pfn_to_bitidx(zone, pfn);
6031 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6033 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
6035 __set_bit(bitidx + start_bitidx, bitmap);
6037 __clear_bit(bitidx + start_bitidx, bitmap);
6041 * This function checks whether pageblock includes unmovable pages or not.
6042 * If @count is not zero, it is okay to include less @count unmovable pages
6044 * PageLRU check without isolation or lru_lock could race so that
6045 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6046 * expect this function should be exact.
6048 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6049 bool skip_hwpoisoned_pages)
6051 unsigned long pfn, iter, found;
6055 * For avoiding noise data, lru_add_drain_all() should be called
6056 * If ZONE_MOVABLE, the zone never contains unmovable pages
6058 if (zone_idx(zone) == ZONE_MOVABLE)
6060 mt = get_pageblock_migratetype(page);
6061 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6064 pfn = page_to_pfn(page);
6065 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6066 unsigned long check = pfn + iter;
6068 if (!pfn_valid_within(check))
6071 page = pfn_to_page(check);
6074 * Hugepages are not in LRU lists, but they're movable.
6075 * We need not scan over tail pages bacause we don't
6076 * handle each tail page individually in migration.
6078 if (PageHuge(page)) {
6079 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6084 * We can't use page_count without pin a page
6085 * because another CPU can free compound page.
6086 * This check already skips compound tails of THP
6087 * because their page->_count is zero at all time.
6089 if (!atomic_read(&page->_count)) {
6090 if (PageBuddy(page))
6091 iter += (1 << page_order(page)) - 1;
6096 * The HWPoisoned page may be not in buddy system, and
6097 * page_count() is not 0.
6099 if (skip_hwpoisoned_pages && PageHWPoison(page))
6105 * If there are RECLAIMABLE pages, we need to check it.
6106 * But now, memory offline itself doesn't call shrink_slab()
6107 * and it still to be fixed.
6110 * If the page is not RAM, page_count()should be 0.
6111 * we don't need more check. This is an _used_ not-movable page.
6113 * The problematic thing here is PG_reserved pages. PG_reserved
6114 * is set to both of a memory hole page and a _used_ kernel
6123 bool is_pageblock_removable_nolock(struct page *page)
6129 * We have to be careful here because we are iterating over memory
6130 * sections which are not zone aware so we might end up outside of
6131 * the zone but still within the section.
6132 * We have to take care about the node as well. If the node is offline
6133 * its NODE_DATA will be NULL - see page_zone.
6135 if (!node_online(page_to_nid(page)))
6138 zone = page_zone(page);
6139 pfn = page_to_pfn(page);
6140 if (!zone_spans_pfn(zone, pfn))
6143 return !has_unmovable_pages(zone, page, 0, true);
6148 static unsigned long pfn_max_align_down(unsigned long pfn)
6150 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6151 pageblock_nr_pages) - 1);
6154 static unsigned long pfn_max_align_up(unsigned long pfn)
6156 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6157 pageblock_nr_pages));
6160 /* [start, end) must belong to a single zone. */
6161 static int __alloc_contig_migrate_range(struct compact_control *cc,
6162 unsigned long start, unsigned long end)
6164 /* This function is based on compact_zone() from compaction.c. */
6165 unsigned long nr_reclaimed;
6166 unsigned long pfn = start;
6167 unsigned int tries = 0;
6172 while (pfn < end || !list_empty(&cc->migratepages)) {
6173 if (fatal_signal_pending(current)) {
6178 if (list_empty(&cc->migratepages)) {
6179 cc->nr_migratepages = 0;
6180 pfn = isolate_migratepages_range(cc->zone, cc,
6187 } else if (++tries == 5) {
6188 ret = ret < 0 ? ret : -EBUSY;
6192 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6194 cc->nr_migratepages -= nr_reclaimed;
6196 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6197 0, MIGRATE_SYNC, MR_CMA);
6200 putback_movable_pages(&cc->migratepages);
6207 * alloc_contig_range() -- tries to allocate given range of pages
6208 * @start: start PFN to allocate
6209 * @end: one-past-the-last PFN to allocate
6210 * @migratetype: migratetype of the underlaying pageblocks (either
6211 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6212 * in range must have the same migratetype and it must
6213 * be either of the two.
6215 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6216 * aligned, however it's the caller's responsibility to guarantee that
6217 * we are the only thread that changes migrate type of pageblocks the
6220 * The PFN range must belong to a single zone.
6222 * Returns zero on success or negative error code. On success all
6223 * pages which PFN is in [start, end) are allocated for the caller and
6224 * need to be freed with free_contig_range().
6226 int alloc_contig_range(unsigned long start, unsigned long end,
6227 unsigned migratetype)
6229 unsigned long outer_start, outer_end;
6232 struct compact_control cc = {
6233 .nr_migratepages = 0,
6235 .zone = page_zone(pfn_to_page(start)),
6237 .ignore_skip_hint = true,
6239 INIT_LIST_HEAD(&cc.migratepages);
6242 * What we do here is we mark all pageblocks in range as
6243 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6244 * have different sizes, and due to the way page allocator
6245 * work, we align the range to biggest of the two pages so
6246 * that page allocator won't try to merge buddies from
6247 * different pageblocks and change MIGRATE_ISOLATE to some
6248 * other migration type.
6250 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6251 * migrate the pages from an unaligned range (ie. pages that
6252 * we are interested in). This will put all the pages in
6253 * range back to page allocator as MIGRATE_ISOLATE.
6255 * When this is done, we take the pages in range from page
6256 * allocator removing them from the buddy system. This way
6257 * page allocator will never consider using them.
6259 * This lets us mark the pageblocks back as
6260 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6261 * aligned range but not in the unaligned, original range are
6262 * put back to page allocator so that buddy can use them.
6265 ret = start_isolate_page_range(pfn_max_align_down(start),
6266 pfn_max_align_up(end), migratetype,
6271 ret = __alloc_contig_migrate_range(&cc, start, end);
6276 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6277 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6278 * more, all pages in [start, end) are free in page allocator.
6279 * What we are going to do is to allocate all pages from
6280 * [start, end) (that is remove them from page allocator).
6282 * The only problem is that pages at the beginning and at the
6283 * end of interesting range may be not aligned with pages that
6284 * page allocator holds, ie. they can be part of higher order
6285 * pages. Because of this, we reserve the bigger range and
6286 * once this is done free the pages we are not interested in.
6288 * We don't have to hold zone->lock here because the pages are
6289 * isolated thus they won't get removed from buddy.
6292 lru_add_drain_all();
6296 outer_start = start;
6297 while (!PageBuddy(pfn_to_page(outer_start))) {
6298 if (++order >= MAX_ORDER) {
6302 outer_start &= ~0UL << order;
6305 /* Make sure the range is really isolated. */
6306 if (test_pages_isolated(outer_start, end, false)) {
6307 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
6314 /* Grab isolated pages from freelists. */
6315 outer_end = isolate_freepages_range(&cc, outer_start, end);
6321 /* Free head and tail (if any) */
6322 if (start != outer_start)
6323 free_contig_range(outer_start, start - outer_start);
6324 if (end != outer_end)
6325 free_contig_range(end, outer_end - end);
6328 undo_isolate_page_range(pfn_max_align_down(start),
6329 pfn_max_align_up(end), migratetype);
6333 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6335 unsigned int count = 0;
6337 for (; nr_pages--; pfn++) {
6338 struct page *page = pfn_to_page(pfn);
6340 count += page_count(page) != 1;
6343 WARN(count != 0, "%d pages are still in use!\n", count);
6347 #ifdef CONFIG_MEMORY_HOTPLUG
6349 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6350 * page high values need to be recalulated.
6352 void __meminit zone_pcp_update(struct zone *zone)
6355 mutex_lock(&pcp_batch_high_lock);
6356 for_each_possible_cpu(cpu)
6357 pageset_set_high_and_batch(zone,
6358 per_cpu_ptr(zone->pageset, cpu));
6359 mutex_unlock(&pcp_batch_high_lock);
6363 void zone_pcp_reset(struct zone *zone)
6365 unsigned long flags;
6367 struct per_cpu_pageset *pset;
6369 /* avoid races with drain_pages() */
6370 local_irq_save(flags);
6371 if (zone->pageset != &boot_pageset) {
6372 for_each_online_cpu(cpu) {
6373 pset = per_cpu_ptr(zone->pageset, cpu);
6374 drain_zonestat(zone, pset);
6376 free_percpu(zone->pageset);
6377 zone->pageset = &boot_pageset;
6379 local_irq_restore(flags);
6382 #ifdef CONFIG_MEMORY_HOTREMOVE
6384 * All pages in the range must be isolated before calling this.
6387 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6393 unsigned long flags;
6394 /* find the first valid pfn */
6395 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6400 zone = page_zone(pfn_to_page(pfn));
6401 spin_lock_irqsave(&zone->lock, flags);
6403 while (pfn < end_pfn) {
6404 if (!pfn_valid(pfn)) {
6408 page = pfn_to_page(pfn);
6410 * The HWPoisoned page may be not in buddy system, and
6411 * page_count() is not 0.
6413 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
6415 SetPageReserved(page);
6419 BUG_ON(page_count(page));
6420 BUG_ON(!PageBuddy(page));
6421 order = page_order(page);
6422 #ifdef CONFIG_DEBUG_VM
6423 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6424 pfn, 1 << order, end_pfn);
6426 list_del(&page->lru);
6427 rmv_page_order(page);
6428 zone->free_area[order].nr_free--;
6429 for (i = 0; i < (1 << order); i++)
6430 SetPageReserved((page+i));
6431 pfn += (1 << order);
6433 spin_unlock_irqrestore(&zone->lock, flags);
6437 #ifdef CONFIG_MEMORY_FAILURE
6438 bool is_free_buddy_page(struct page *page)
6440 struct zone *zone = page_zone(page);
6441 unsigned long pfn = page_to_pfn(page);
6442 unsigned long flags;
6445 spin_lock_irqsave(&zone->lock, flags);
6446 for (order = 0; order < MAX_ORDER; order++) {
6447 struct page *page_head = page - (pfn & ((1 << order) - 1));
6449 if (PageBuddy(page_head) && page_order(page_head) >= order)
6452 spin_unlock_irqrestore(&zone->lock, flags);
6454 return order < MAX_ORDER;
6458 static const struct trace_print_flags pageflag_names[] = {
6459 {1UL << PG_locked, "locked" },
6460 {1UL << PG_error, "error" },
6461 {1UL << PG_referenced, "referenced" },
6462 {1UL << PG_uptodate, "uptodate" },
6463 {1UL << PG_dirty, "dirty" },
6464 {1UL << PG_lru, "lru" },
6465 {1UL << PG_active, "active" },
6466 {1UL << PG_slab, "slab" },
6467 {1UL << PG_owner_priv_1, "owner_priv_1" },
6468 {1UL << PG_arch_1, "arch_1" },
6469 {1UL << PG_reserved, "reserved" },
6470 {1UL << PG_private, "private" },
6471 {1UL << PG_private_2, "private_2" },
6472 {1UL << PG_writeback, "writeback" },
6473 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6474 {1UL << PG_head, "head" },
6475 {1UL << PG_tail, "tail" },
6477 {1UL << PG_compound, "compound" },
6479 {1UL << PG_swapcache, "swapcache" },
6480 {1UL << PG_mappedtodisk, "mappedtodisk" },
6481 {1UL << PG_reclaim, "reclaim" },
6482 {1UL << PG_swapbacked, "swapbacked" },
6483 {1UL << PG_unevictable, "unevictable" },
6485 {1UL << PG_mlocked, "mlocked" },
6487 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6488 {1UL << PG_uncached, "uncached" },
6490 #ifdef CONFIG_MEMORY_FAILURE
6491 {1UL << PG_hwpoison, "hwpoison" },
6493 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6494 {1UL << PG_compound_lock, "compound_lock" },
6498 static void dump_page_flags(unsigned long flags)
6500 const char *delim = "";
6504 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
6506 printk(KERN_ALERT "page flags: %#lx(", flags);
6508 /* remove zone id */
6509 flags &= (1UL << NR_PAGEFLAGS) - 1;
6511 for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) {
6513 mask = pageflag_names[i].mask;
6514 if ((flags & mask) != mask)
6518 printk("%s%s", delim, pageflag_names[i].name);
6522 /* check for left over flags */
6524 printk("%s%#lx", delim, flags);
6529 void dump_page_badflags(struct page *page, char *reason, unsigned long badflags)
6532 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6533 page, atomic_read(&page->_count), page_mapcount(page),
6534 page->mapping, page->index);
6535 dump_page_flags(page->flags);
6537 pr_alert("page dumped because: %s\n", reason);
6538 if (page->flags & badflags) {
6539 pr_alert("bad because of flags:\n");
6540 dump_page_flags(page->flags & badflags);
6542 mem_cgroup_print_bad_page(page);
6545 void dump_page(struct page *page, char *reason)
6547 dump_page_badflags(page, reason, 0);
6549 EXPORT_SYMBOL_GPL(dump_page);