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/memory.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/ftrace_event.h>
58 #include <linux/memcontrol.h>
59 #include <linux/prefetch.h>
60 #include <linux/page-debug-flags.h>
62 #include <asm/tlbflush.h>
63 #include <asm/div64.h>
66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
67 DEFINE_PER_CPU(int, numa_node);
68 EXPORT_PER_CPU_SYMBOL(numa_node);
71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
73 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
74 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
75 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
76 * defined in <linux/topology.h>.
78 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
79 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
83 * Array of node states.
85 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
86 [N_POSSIBLE] = NODE_MASK_ALL,
87 [N_ONLINE] = { { [0] = 1UL } },
89 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
91 [N_HIGH_MEMORY] = { { [0] = 1UL } },
93 [N_CPU] = { { [0] = 1UL } },
96 EXPORT_SYMBOL(node_states);
98 unsigned long totalram_pages __read_mostly;
99 unsigned long totalreserve_pages __read_mostly;
101 * When calculating the number of globally allowed dirty pages, there
102 * is a certain number of per-zone reserves that should not be
103 * considered dirtyable memory. This is the sum of those reserves
104 * over all existing zones that contribute dirtyable memory.
106 unsigned long dirty_balance_reserve __read_mostly;
108 int percpu_pagelist_fraction;
109 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
111 #ifdef CONFIG_PM_SLEEP
113 * The following functions are used by the suspend/hibernate code to temporarily
114 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
115 * while devices are suspended. To avoid races with the suspend/hibernate code,
116 * they should always be called with pm_mutex held (gfp_allowed_mask also should
117 * only be modified with pm_mutex held, unless the suspend/hibernate code is
118 * guaranteed not to run in parallel with that modification).
121 static gfp_t saved_gfp_mask;
123 void pm_restore_gfp_mask(void)
125 WARN_ON(!mutex_is_locked(&pm_mutex));
126 if (saved_gfp_mask) {
127 gfp_allowed_mask = saved_gfp_mask;
132 void pm_restrict_gfp_mask(void)
134 WARN_ON(!mutex_is_locked(&pm_mutex));
135 WARN_ON(saved_gfp_mask);
136 saved_gfp_mask = gfp_allowed_mask;
137 gfp_allowed_mask &= ~GFP_IOFS;
140 bool pm_suspended_storage(void)
142 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
146 #endif /* CONFIG_PM_SLEEP */
148 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
149 int pageblock_order __read_mostly;
152 static void __free_pages_ok(struct page *page, unsigned int order);
155 * results with 256, 32 in the lowmem_reserve sysctl:
156 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
157 * 1G machine -> (16M dma, 784M normal, 224M high)
158 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
159 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
160 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
162 * TBD: should special case ZONE_DMA32 machines here - in those we normally
163 * don't need any ZONE_NORMAL reservation
165 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
166 #ifdef CONFIG_ZONE_DMA
169 #ifdef CONFIG_ZONE_DMA32
172 #ifdef CONFIG_HIGHMEM
178 EXPORT_SYMBOL(totalram_pages);
180 static char * const zone_names[MAX_NR_ZONES] = {
181 #ifdef CONFIG_ZONE_DMA
184 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 int min_free_kbytes = 1024;
196 static unsigned long __meminitdata nr_kernel_pages;
197 static unsigned long __meminitdata nr_all_pages;
198 static unsigned long __meminitdata dma_reserve;
200 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
201 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
202 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
203 static unsigned long __initdata required_kernelcore;
204 static unsigned long __initdata required_movablecore;
205 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
207 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
209 EXPORT_SYMBOL(movable_zone);
210 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
213 int nr_node_ids __read_mostly = MAX_NUMNODES;
214 int nr_online_nodes __read_mostly = 1;
215 EXPORT_SYMBOL(nr_node_ids);
216 EXPORT_SYMBOL(nr_online_nodes);
219 int page_group_by_mobility_disabled __read_mostly;
221 static void set_pageblock_migratetype(struct page *page, int migratetype)
224 if (unlikely(page_group_by_mobility_disabled))
225 migratetype = MIGRATE_UNMOVABLE;
227 set_pageblock_flags_group(page, (unsigned long)migratetype,
228 PB_migrate, PB_migrate_end);
231 bool oom_killer_disabled __read_mostly;
233 #ifdef CONFIG_DEBUG_VM
234 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
238 unsigned long pfn = page_to_pfn(page);
241 seq = zone_span_seqbegin(zone);
242 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
244 else if (pfn < zone->zone_start_pfn)
246 } while (zone_span_seqretry(zone, seq));
251 static int page_is_consistent(struct zone *zone, struct page *page)
253 if (!pfn_valid_within(page_to_pfn(page)))
255 if (zone != page_zone(page))
261 * Temporary debugging check for pages not lying within a given zone.
263 static int bad_range(struct zone *zone, struct page *page)
265 if (page_outside_zone_boundaries(zone, page))
267 if (!page_is_consistent(zone, page))
273 static inline int bad_range(struct zone *zone, struct page *page)
279 static void bad_page(struct page *page)
281 static unsigned long resume;
282 static unsigned long nr_shown;
283 static unsigned long nr_unshown;
285 /* Don't complain about poisoned pages */
286 if (PageHWPoison(page)) {
287 reset_page_mapcount(page); /* remove PageBuddy */
292 * Allow a burst of 60 reports, then keep quiet for that minute;
293 * or allow a steady drip of one report per second.
295 if (nr_shown == 60) {
296 if (time_before(jiffies, resume)) {
302 "BUG: Bad page state: %lu messages suppressed\n",
309 resume = jiffies + 60 * HZ;
311 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
312 current->comm, page_to_pfn(page));
318 /* Leave bad fields for debug, except PageBuddy could make trouble */
319 reset_page_mapcount(page); /* remove PageBuddy */
320 add_taint(TAINT_BAD_PAGE);
324 * Higher-order pages are called "compound pages". They are structured thusly:
326 * The first PAGE_SIZE page is called the "head page".
328 * The remaining PAGE_SIZE pages are called "tail pages".
330 * All pages have PG_compound set. All tail pages have their ->first_page
331 * pointing at the head page.
333 * The first tail page's ->lru.next holds the address of the compound page's
334 * put_page() function. Its ->lru.prev holds the order of allocation.
335 * This usage means that zero-order pages may not be compound.
338 static void free_compound_page(struct page *page)
340 __free_pages_ok(page, compound_order(page));
343 void prep_compound_page(struct page *page, unsigned long order)
346 int nr_pages = 1 << order;
348 set_compound_page_dtor(page, free_compound_page);
349 set_compound_order(page, order);
351 for (i = 1; i < nr_pages; i++) {
352 struct page *p = page + i;
354 set_page_count(p, 0);
355 p->first_page = page;
359 /* update __split_huge_page_refcount if you change this function */
360 static int destroy_compound_page(struct page *page, unsigned long order)
363 int nr_pages = 1 << order;
366 if (unlikely(compound_order(page) != order) ||
367 unlikely(!PageHead(page))) {
372 __ClearPageHead(page);
374 for (i = 1; i < nr_pages; i++) {
375 struct page *p = page + i;
377 if (unlikely(!PageTail(p) || (p->first_page != page))) {
387 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
392 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
393 * and __GFP_HIGHMEM from hard or soft interrupt context.
395 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
396 for (i = 0; i < (1 << order); i++)
397 clear_highpage(page + i);
400 #ifdef CONFIG_DEBUG_PAGEALLOC
401 unsigned int _debug_guardpage_minorder;
403 static int __init debug_guardpage_minorder_setup(char *buf)
407 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
408 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
411 _debug_guardpage_minorder = res;
412 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
415 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
417 static inline void set_page_guard_flag(struct page *page)
419 __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
422 static inline void clear_page_guard_flag(struct page *page)
424 __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
427 static inline void set_page_guard_flag(struct page *page) { }
428 static inline void clear_page_guard_flag(struct page *page) { }
431 static inline void set_page_order(struct page *page, int order)
433 set_page_private(page, order);
434 __SetPageBuddy(page);
437 static inline void rmv_page_order(struct page *page)
439 __ClearPageBuddy(page);
440 set_page_private(page, 0);
444 * Locate the struct page for both the matching buddy in our
445 * pair (buddy1) and the combined O(n+1) page they form (page).
447 * 1) Any buddy B1 will have an order O twin B2 which satisfies
448 * the following equation:
450 * For example, if the starting buddy (buddy2) is #8 its order
452 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
454 * 2) Any buddy B will have an order O+1 parent P which
455 * satisfies the following equation:
458 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
460 static inline unsigned long
461 __find_buddy_index(unsigned long page_idx, unsigned int order)
463 return page_idx ^ (1 << order);
467 * This function checks whether a page is free && is the buddy
468 * we can do coalesce a page and its buddy if
469 * (a) the buddy is not in a hole &&
470 * (b) the buddy is in the buddy system &&
471 * (c) a page and its buddy have the same order &&
472 * (d) a page and its buddy are in the same zone.
474 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
475 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
477 * For recording page's order, we use page_private(page).
479 static inline int page_is_buddy(struct page *page, struct page *buddy,
482 if (!pfn_valid_within(page_to_pfn(buddy)))
485 if (page_zone_id(page) != page_zone_id(buddy))
488 if (page_is_guard(buddy) && page_order(buddy) == order) {
489 VM_BUG_ON(page_count(buddy) != 0);
493 if (PageBuddy(buddy) && page_order(buddy) == order) {
494 VM_BUG_ON(page_count(buddy) != 0);
501 * Freeing function for a buddy system allocator.
503 * The concept of a buddy system is to maintain direct-mapped table
504 * (containing bit values) for memory blocks of various "orders".
505 * The bottom level table contains the map for the smallest allocatable
506 * units of memory (here, pages), and each level above it describes
507 * pairs of units from the levels below, hence, "buddies".
508 * At a high level, all that happens here is marking the table entry
509 * at the bottom level available, and propagating the changes upward
510 * as necessary, plus some accounting needed to play nicely with other
511 * parts of the VM system.
512 * At each level, we keep a list of pages, which are heads of continuous
513 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
514 * order is recorded in page_private(page) field.
515 * So when we are allocating or freeing one, we can derive the state of the
516 * other. That is, if we allocate a small block, and both were
517 * free, the remainder of the region must be split into blocks.
518 * If a block is freed, and its buddy is also free, then this
519 * triggers coalescing into a block of larger size.
524 static inline void __free_one_page(struct page *page,
525 struct zone *zone, unsigned int order,
528 unsigned long page_idx;
529 unsigned long combined_idx;
530 unsigned long uninitialized_var(buddy_idx);
533 if (unlikely(PageCompound(page)))
534 if (unlikely(destroy_compound_page(page, order)))
537 VM_BUG_ON(migratetype == -1);
539 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
541 VM_BUG_ON(page_idx & ((1 << order) - 1));
542 VM_BUG_ON(bad_range(zone, page));
544 while (order < MAX_ORDER-1) {
545 buddy_idx = __find_buddy_index(page_idx, order);
546 buddy = page + (buddy_idx - page_idx);
547 if (!page_is_buddy(page, buddy, order))
550 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
551 * merge with it and move up one order.
553 if (page_is_guard(buddy)) {
554 clear_page_guard_flag(buddy);
555 set_page_private(page, 0);
556 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
558 list_del(&buddy->lru);
559 zone->free_area[order].nr_free--;
560 rmv_page_order(buddy);
562 combined_idx = buddy_idx & page_idx;
563 page = page + (combined_idx - page_idx);
564 page_idx = combined_idx;
567 set_page_order(page, order);
570 * If this is not the largest possible page, check if the buddy
571 * of the next-highest order is free. If it is, it's possible
572 * that pages are being freed that will coalesce soon. In case,
573 * that is happening, add the free page to the tail of the list
574 * so it's less likely to be used soon and more likely to be merged
575 * as a higher order page
577 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
578 struct page *higher_page, *higher_buddy;
579 combined_idx = buddy_idx & page_idx;
580 higher_page = page + (combined_idx - page_idx);
581 buddy_idx = __find_buddy_index(combined_idx, order + 1);
582 higher_buddy = page + (buddy_idx - combined_idx);
583 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
584 list_add_tail(&page->lru,
585 &zone->free_area[order].free_list[migratetype]);
590 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
592 zone->free_area[order].nr_free++;
596 * free_page_mlock() -- clean up attempts to free and mlocked() page.
597 * Page should not be on lru, so no need to fix that up.
598 * free_pages_check() will verify...
600 static inline void free_page_mlock(struct page *page)
602 __dec_zone_page_state(page, NR_MLOCK);
603 __count_vm_event(UNEVICTABLE_MLOCKFREED);
606 static inline int free_pages_check(struct page *page)
608 if (unlikely(page_mapcount(page) |
609 (page->mapping != NULL) |
610 (atomic_read(&page->_count) != 0) |
611 (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
612 (mem_cgroup_bad_page_check(page)))) {
616 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
617 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
622 * Frees a number of pages from the PCP lists
623 * Assumes all pages on list are in same zone, and of same order.
624 * count is the number of pages to free.
626 * If the zone was previously in an "all pages pinned" state then look to
627 * see if this freeing clears that state.
629 * And clear the zone's pages_scanned counter, to hold off the "all pages are
630 * pinned" detection logic.
632 static void free_pcppages_bulk(struct zone *zone, int count,
633 struct per_cpu_pages *pcp)
639 spin_lock(&zone->lock);
640 zone->all_unreclaimable = 0;
641 zone->pages_scanned = 0;
645 struct list_head *list;
648 * Remove pages from lists in a round-robin fashion. A
649 * batch_free count is maintained that is incremented when an
650 * empty list is encountered. This is so more pages are freed
651 * off fuller lists instead of spinning excessively around empty
656 if (++migratetype == MIGRATE_PCPTYPES)
658 list = &pcp->lists[migratetype];
659 } while (list_empty(list));
661 /* This is the only non-empty list. Free them all. */
662 if (batch_free == MIGRATE_PCPTYPES)
663 batch_free = to_free;
666 page = list_entry(list->prev, struct page, lru);
667 /* must delete as __free_one_page list manipulates */
668 list_del(&page->lru);
669 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
670 __free_one_page(page, zone, 0, page_private(page));
671 trace_mm_page_pcpu_drain(page, 0, page_private(page));
672 } while (--to_free && --batch_free && !list_empty(list));
674 __mod_zone_page_state(zone, NR_FREE_PAGES, count);
675 spin_unlock(&zone->lock);
678 static void free_one_page(struct zone *zone, struct page *page, int order,
681 spin_lock(&zone->lock);
682 zone->all_unreclaimable = 0;
683 zone->pages_scanned = 0;
685 __free_one_page(page, zone, order, migratetype);
686 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
687 spin_unlock(&zone->lock);
690 static bool free_pages_prepare(struct page *page, unsigned int order)
695 trace_mm_page_free(page, order);
696 kmemcheck_free_shadow(page, order);
699 page->mapping = NULL;
700 for (i = 0; i < (1 << order); i++)
701 bad += free_pages_check(page + i);
705 if (!PageHighMem(page)) {
706 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
707 debug_check_no_obj_freed(page_address(page),
710 arch_free_page(page, order);
711 kernel_map_pages(page, 1 << order, 0);
716 static void __free_pages_ok(struct page *page, unsigned int order)
719 int wasMlocked = __TestClearPageMlocked(page);
721 if (!free_pages_prepare(page, order))
724 local_irq_save(flags);
725 if (unlikely(wasMlocked))
726 free_page_mlock(page);
727 __count_vm_events(PGFREE, 1 << order);
728 free_one_page(page_zone(page), page, order,
729 get_pageblock_migratetype(page));
730 local_irq_restore(flags);
733 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
735 unsigned int nr_pages = 1 << order;
739 for (loop = 0; loop < nr_pages; loop++) {
740 struct page *p = &page[loop];
742 if (loop + 1 < nr_pages)
744 __ClearPageReserved(p);
745 set_page_count(p, 0);
748 set_page_refcounted(page);
749 __free_pages(page, order);
754 * The order of subdivision here is critical for the IO subsystem.
755 * Please do not alter this order without good reasons and regression
756 * testing. Specifically, as large blocks of memory are subdivided,
757 * the order in which smaller blocks are delivered depends on the order
758 * they're subdivided in this function. This is the primary factor
759 * influencing the order in which pages are delivered to the IO
760 * subsystem according to empirical testing, and this is also justified
761 * by considering the behavior of a buddy system containing a single
762 * large block of memory acted on by a series of small allocations.
763 * This behavior is a critical factor in sglist merging's success.
767 static inline void expand(struct zone *zone, struct page *page,
768 int low, int high, struct free_area *area,
771 unsigned long size = 1 << high;
777 VM_BUG_ON(bad_range(zone, &page[size]));
779 #ifdef CONFIG_DEBUG_PAGEALLOC
780 if (high < debug_guardpage_minorder()) {
782 * Mark as guard pages (or page), that will allow to
783 * merge back to allocator when buddy will be freed.
784 * Corresponding page table entries will not be touched,
785 * pages will stay not present in virtual address space
787 INIT_LIST_HEAD(&page[size].lru);
788 set_page_guard_flag(&page[size]);
789 set_page_private(&page[size], high);
790 /* Guard pages are not available for any usage */
791 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << high));
795 list_add(&page[size].lru, &area->free_list[migratetype]);
797 set_page_order(&page[size], high);
802 * This page is about to be returned from the page allocator
804 static inline int check_new_page(struct page *page)
806 if (unlikely(page_mapcount(page) |
807 (page->mapping != NULL) |
808 (atomic_read(&page->_count) != 0) |
809 (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
810 (mem_cgroup_bad_page_check(page)))) {
817 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
821 for (i = 0; i < (1 << order); i++) {
822 struct page *p = page + i;
823 if (unlikely(check_new_page(p)))
827 set_page_private(page, 0);
828 set_page_refcounted(page);
830 arch_alloc_page(page, order);
831 kernel_map_pages(page, 1 << order, 1);
833 if (gfp_flags & __GFP_ZERO)
834 prep_zero_page(page, order, gfp_flags);
836 if (order && (gfp_flags & __GFP_COMP))
837 prep_compound_page(page, order);
843 * Go through the free lists for the given migratetype and remove
844 * the smallest available page from the freelists
847 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
850 unsigned int current_order;
851 struct free_area * area;
854 /* Find a page of the appropriate size in the preferred list */
855 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
856 area = &(zone->free_area[current_order]);
857 if (list_empty(&area->free_list[migratetype]))
860 page = list_entry(area->free_list[migratetype].next,
862 list_del(&page->lru);
863 rmv_page_order(page);
865 expand(zone, page, order, current_order, area, migratetype);
874 * This array describes the order lists are fallen back to when
875 * the free lists for the desirable migrate type are depleted
877 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
878 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
879 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
880 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
881 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
885 * Move the free pages in a range to the free lists of the requested type.
886 * Note that start_page and end_pages are not aligned on a pageblock
887 * boundary. If alignment is required, use move_freepages_block()
889 static int move_freepages(struct zone *zone,
890 struct page *start_page, struct page *end_page,
897 #ifndef CONFIG_HOLES_IN_ZONE
899 * page_zone is not safe to call in this context when
900 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
901 * anyway as we check zone boundaries in move_freepages_block().
902 * Remove at a later date when no bug reports exist related to
903 * grouping pages by mobility
905 BUG_ON(page_zone(start_page) != page_zone(end_page));
908 for (page = start_page; page <= end_page;) {
909 /* Make sure we are not inadvertently changing nodes */
910 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
912 if (!pfn_valid_within(page_to_pfn(page))) {
917 if (!PageBuddy(page)) {
922 order = page_order(page);
923 list_move(&page->lru,
924 &zone->free_area[order].free_list[migratetype]);
926 pages_moved += 1 << order;
932 static int move_freepages_block(struct zone *zone, struct page *page,
935 unsigned long start_pfn, end_pfn;
936 struct page *start_page, *end_page;
938 start_pfn = page_to_pfn(page);
939 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
940 start_page = pfn_to_page(start_pfn);
941 end_page = start_page + pageblock_nr_pages - 1;
942 end_pfn = start_pfn + pageblock_nr_pages - 1;
944 /* Do not cross zone boundaries */
945 if (start_pfn < zone->zone_start_pfn)
947 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
950 return move_freepages(zone, start_page, end_page, migratetype);
953 static void change_pageblock_range(struct page *pageblock_page,
954 int start_order, int migratetype)
956 int nr_pageblocks = 1 << (start_order - pageblock_order);
958 while (nr_pageblocks--) {
959 set_pageblock_migratetype(pageblock_page, migratetype);
960 pageblock_page += pageblock_nr_pages;
964 /* Remove an element from the buddy allocator from the fallback list */
965 static inline struct page *
966 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
968 struct free_area * area;
973 /* Find the largest possible block of pages in the other list */
974 for (current_order = MAX_ORDER-1; current_order >= order;
976 for (i = 0; i < MIGRATE_TYPES - 1; i++) {
977 migratetype = fallbacks[start_migratetype][i];
979 /* MIGRATE_RESERVE handled later if necessary */
980 if (migratetype == MIGRATE_RESERVE)
983 area = &(zone->free_area[current_order]);
984 if (list_empty(&area->free_list[migratetype]))
987 page = list_entry(area->free_list[migratetype].next,
992 * If breaking a large block of pages, move all free
993 * pages to the preferred allocation list. If falling
994 * back for a reclaimable kernel allocation, be more
995 * aggressive about taking ownership of free pages
997 if (unlikely(current_order >= (pageblock_order >> 1)) ||
998 start_migratetype == MIGRATE_RECLAIMABLE ||
999 page_group_by_mobility_disabled) {
1000 unsigned long pages;
1001 pages = move_freepages_block(zone, page,
1004 /* Claim the whole block if over half of it is free */
1005 if (pages >= (1 << (pageblock_order-1)) ||
1006 page_group_by_mobility_disabled)
1007 set_pageblock_migratetype(page,
1010 migratetype = start_migratetype;
1013 /* Remove the page from the freelists */
1014 list_del(&page->lru);
1015 rmv_page_order(page);
1017 /* Take ownership for orders >= pageblock_order */
1018 if (current_order >= pageblock_order)
1019 change_pageblock_range(page, current_order,
1022 expand(zone, page, order, current_order, area, migratetype);
1024 trace_mm_page_alloc_extfrag(page, order, current_order,
1025 start_migratetype, migratetype);
1035 * Do the hard work of removing an element from the buddy allocator.
1036 * Call me with the zone->lock already held.
1038 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1044 page = __rmqueue_smallest(zone, order, migratetype);
1046 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1047 page = __rmqueue_fallback(zone, order, migratetype);
1050 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1051 * is used because __rmqueue_smallest is an inline function
1052 * and we want just one call site
1055 migratetype = MIGRATE_RESERVE;
1060 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1065 * Obtain a specified number of elements from the buddy allocator, all under
1066 * a single hold of the lock, for efficiency. Add them to the supplied list.
1067 * Returns the number of new pages which were placed at *list.
1069 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1070 unsigned long count, struct list_head *list,
1071 int migratetype, int cold)
1075 spin_lock(&zone->lock);
1076 for (i = 0; i < count; ++i) {
1077 struct page *page = __rmqueue(zone, order, migratetype);
1078 if (unlikely(page == NULL))
1082 * Split buddy pages returned by expand() are received here
1083 * in physical page order. The page is added to the callers and
1084 * list and the list head then moves forward. From the callers
1085 * perspective, the linked list is ordered by page number in
1086 * some conditions. This is useful for IO devices that can
1087 * merge IO requests if the physical pages are ordered
1090 if (likely(cold == 0))
1091 list_add(&page->lru, list);
1093 list_add_tail(&page->lru, list);
1094 set_page_private(page, migratetype);
1097 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1098 spin_unlock(&zone->lock);
1104 * Called from the vmstat counter updater to drain pagesets of this
1105 * currently executing processor on remote nodes after they have
1108 * Note that this function must be called with the thread pinned to
1109 * a single processor.
1111 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1113 unsigned long flags;
1116 local_irq_save(flags);
1117 if (pcp->count >= pcp->batch)
1118 to_drain = pcp->batch;
1120 to_drain = pcp->count;
1121 free_pcppages_bulk(zone, to_drain, pcp);
1122 pcp->count -= to_drain;
1123 local_irq_restore(flags);
1128 * Drain pages of the indicated processor.
1130 * The processor must either be the current processor and the
1131 * thread pinned to the current processor or a processor that
1134 static void drain_pages(unsigned int cpu)
1136 unsigned long flags;
1139 for_each_populated_zone(zone) {
1140 struct per_cpu_pageset *pset;
1141 struct per_cpu_pages *pcp;
1143 local_irq_save(flags);
1144 pset = per_cpu_ptr(zone->pageset, cpu);
1148 free_pcppages_bulk(zone, pcp->count, pcp);
1151 local_irq_restore(flags);
1156 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1158 void drain_local_pages(void *arg)
1160 drain_pages(smp_processor_id());
1164 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1166 void drain_all_pages(void)
1168 on_each_cpu(drain_local_pages, NULL, 1);
1171 #ifdef CONFIG_HIBERNATION
1173 void mark_free_pages(struct zone *zone)
1175 unsigned long pfn, max_zone_pfn;
1176 unsigned long flags;
1178 struct list_head *curr;
1180 if (!zone->spanned_pages)
1183 spin_lock_irqsave(&zone->lock, flags);
1185 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1186 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1187 if (pfn_valid(pfn)) {
1188 struct page *page = pfn_to_page(pfn);
1190 if (!swsusp_page_is_forbidden(page))
1191 swsusp_unset_page_free(page);
1194 for_each_migratetype_order(order, t) {
1195 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1198 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1199 for (i = 0; i < (1UL << order); i++)
1200 swsusp_set_page_free(pfn_to_page(pfn + i));
1203 spin_unlock_irqrestore(&zone->lock, flags);
1205 #endif /* CONFIG_PM */
1208 * Free a 0-order page
1209 * cold == 1 ? free a cold page : free a hot page
1211 void free_hot_cold_page(struct page *page, int cold)
1213 struct zone *zone = page_zone(page);
1214 struct per_cpu_pages *pcp;
1215 unsigned long flags;
1217 int wasMlocked = __TestClearPageMlocked(page);
1219 if (!free_pages_prepare(page, 0))
1222 migratetype = get_pageblock_migratetype(page);
1223 set_page_private(page, migratetype);
1224 local_irq_save(flags);
1225 if (unlikely(wasMlocked))
1226 free_page_mlock(page);
1227 __count_vm_event(PGFREE);
1230 * We only track unmovable, reclaimable and movable on pcp lists.
1231 * Free ISOLATE pages back to the allocator because they are being
1232 * offlined but treat RESERVE as movable pages so we can get those
1233 * areas back if necessary. Otherwise, we may have to free
1234 * excessively into the page allocator
1236 if (migratetype >= MIGRATE_PCPTYPES) {
1237 if (unlikely(migratetype == MIGRATE_ISOLATE)) {
1238 free_one_page(zone, page, 0, migratetype);
1241 migratetype = MIGRATE_MOVABLE;
1244 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1246 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1248 list_add(&page->lru, &pcp->lists[migratetype]);
1250 if (pcp->count >= pcp->high) {
1251 free_pcppages_bulk(zone, pcp->batch, pcp);
1252 pcp->count -= pcp->batch;
1256 local_irq_restore(flags);
1260 * Free a list of 0-order pages
1262 void free_hot_cold_page_list(struct list_head *list, int cold)
1264 struct page *page, *next;
1266 list_for_each_entry_safe(page, next, list, lru) {
1267 trace_mm_page_free_batched(page, cold);
1268 free_hot_cold_page(page, cold);
1273 * split_page takes a non-compound higher-order page, and splits it into
1274 * n (1<<order) sub-pages: page[0..n]
1275 * Each sub-page must be freed individually.
1277 * Note: this is probably too low level an operation for use in drivers.
1278 * Please consult with lkml before using this in your driver.
1280 void split_page(struct page *page, unsigned int order)
1284 VM_BUG_ON(PageCompound(page));
1285 VM_BUG_ON(!page_count(page));
1287 #ifdef CONFIG_KMEMCHECK
1289 * Split shadow pages too, because free(page[0]) would
1290 * otherwise free the whole shadow.
1292 if (kmemcheck_page_is_tracked(page))
1293 split_page(virt_to_page(page[0].shadow), order);
1296 for (i = 1; i < (1 << order); i++)
1297 set_page_refcounted(page + i);
1301 * Similar to split_page except the page is already free. As this is only
1302 * being used for migration, the migratetype of the block also changes.
1303 * As this is called with interrupts disabled, the caller is responsible
1304 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1307 * Note: this is probably too low level an operation for use in drivers.
1308 * Please consult with lkml before using this in your driver.
1310 int split_free_page(struct page *page)
1313 unsigned long watermark;
1316 BUG_ON(!PageBuddy(page));
1318 zone = page_zone(page);
1319 order = page_order(page);
1321 /* Obey watermarks as if the page was being allocated */
1322 watermark = low_wmark_pages(zone) + (1 << order);
1323 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1326 /* Remove page from free list */
1327 list_del(&page->lru);
1328 zone->free_area[order].nr_free--;
1329 rmv_page_order(page);
1330 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
1332 /* Split into individual pages */
1333 set_page_refcounted(page);
1334 split_page(page, order);
1336 if (order >= pageblock_order - 1) {
1337 struct page *endpage = page + (1 << order) - 1;
1338 for (; page < endpage; page += pageblock_nr_pages)
1339 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1346 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1347 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1351 struct page *buffered_rmqueue(struct zone *preferred_zone,
1352 struct zone *zone, int order, gfp_t gfp_flags,
1355 unsigned long flags;
1357 int cold = !!(gfp_flags & __GFP_COLD);
1360 if (likely(order == 0)) {
1361 struct per_cpu_pages *pcp;
1362 struct list_head *list;
1364 local_irq_save(flags);
1365 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1366 list = &pcp->lists[migratetype];
1367 if (list_empty(list)) {
1368 pcp->count += rmqueue_bulk(zone, 0,
1371 if (unlikely(list_empty(list)))
1376 page = list_entry(list->prev, struct page, lru);
1378 page = list_entry(list->next, struct page, lru);
1380 list_del(&page->lru);
1383 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1385 * __GFP_NOFAIL is not to be used in new code.
1387 * All __GFP_NOFAIL callers should be fixed so that they
1388 * properly detect and handle allocation failures.
1390 * We most definitely don't want callers attempting to
1391 * allocate greater than order-1 page units with
1394 WARN_ON_ONCE(order > 1);
1396 spin_lock_irqsave(&zone->lock, flags);
1397 page = __rmqueue(zone, order, migratetype);
1398 spin_unlock(&zone->lock);
1401 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
1404 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1405 zone_statistics(preferred_zone, zone, gfp_flags);
1406 local_irq_restore(flags);
1408 VM_BUG_ON(bad_range(zone, page));
1409 if (prep_new_page(page, order, gfp_flags))
1414 local_irq_restore(flags);
1418 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1419 #define ALLOC_WMARK_MIN WMARK_MIN
1420 #define ALLOC_WMARK_LOW WMARK_LOW
1421 #define ALLOC_WMARK_HIGH WMARK_HIGH
1422 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1424 /* Mask to get the watermark bits */
1425 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1427 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1428 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1429 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1431 #ifdef CONFIG_FAIL_PAGE_ALLOC
1434 struct fault_attr attr;
1436 u32 ignore_gfp_highmem;
1437 u32 ignore_gfp_wait;
1439 } fail_page_alloc = {
1440 .attr = FAULT_ATTR_INITIALIZER,
1441 .ignore_gfp_wait = 1,
1442 .ignore_gfp_highmem = 1,
1446 static int __init setup_fail_page_alloc(char *str)
1448 return setup_fault_attr(&fail_page_alloc.attr, str);
1450 __setup("fail_page_alloc=", setup_fail_page_alloc);
1452 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1454 if (order < fail_page_alloc.min_order)
1456 if (gfp_mask & __GFP_NOFAIL)
1458 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1460 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1463 return should_fail(&fail_page_alloc.attr, 1 << order);
1466 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1468 static int __init fail_page_alloc_debugfs(void)
1470 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1473 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1474 &fail_page_alloc.attr);
1476 return PTR_ERR(dir);
1478 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1479 &fail_page_alloc.ignore_gfp_wait))
1481 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1482 &fail_page_alloc.ignore_gfp_highmem))
1484 if (!debugfs_create_u32("min-order", mode, dir,
1485 &fail_page_alloc.min_order))
1490 debugfs_remove_recursive(dir);
1495 late_initcall(fail_page_alloc_debugfs);
1497 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1499 #else /* CONFIG_FAIL_PAGE_ALLOC */
1501 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1506 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1509 * Return true if free pages are above 'mark'. This takes into account the order
1510 * of the allocation.
1512 static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1513 int classzone_idx, int alloc_flags, long free_pages)
1515 /* free_pages my go negative - that's OK */
1519 free_pages -= (1 << order) - 1;
1520 if (alloc_flags & ALLOC_HIGH)
1522 if (alloc_flags & ALLOC_HARDER)
1525 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1527 for (o = 0; o < order; o++) {
1528 /* At the next order, this order's pages become unavailable */
1529 free_pages -= z->free_area[o].nr_free << o;
1531 /* Require fewer higher order pages to be free */
1534 if (free_pages <= min)
1540 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1541 int classzone_idx, int alloc_flags)
1543 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1544 zone_page_state(z, NR_FREE_PAGES));
1547 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
1548 int classzone_idx, int alloc_flags)
1550 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1552 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1553 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1555 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1561 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1562 * skip over zones that are not allowed by the cpuset, or that have
1563 * been recently (in last second) found to be nearly full. See further
1564 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1565 * that have to skip over a lot of full or unallowed zones.
1567 * If the zonelist cache is present in the passed in zonelist, then
1568 * returns a pointer to the allowed node mask (either the current
1569 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1571 * If the zonelist cache is not available for this zonelist, does
1572 * nothing and returns NULL.
1574 * If the fullzones BITMAP in the zonelist cache is stale (more than
1575 * a second since last zap'd) then we zap it out (clear its bits.)
1577 * We hold off even calling zlc_setup, until after we've checked the
1578 * first zone in the zonelist, on the theory that most allocations will
1579 * be satisfied from that first zone, so best to examine that zone as
1580 * quickly as we can.
1582 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1584 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1585 nodemask_t *allowednodes; /* zonelist_cache approximation */
1587 zlc = zonelist->zlcache_ptr;
1591 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1592 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1593 zlc->last_full_zap = jiffies;
1596 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1597 &cpuset_current_mems_allowed :
1598 &node_states[N_HIGH_MEMORY];
1599 return allowednodes;
1603 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1604 * if it is worth looking at further for free memory:
1605 * 1) Check that the zone isn't thought to be full (doesn't have its
1606 * bit set in the zonelist_cache fullzones BITMAP).
1607 * 2) Check that the zones node (obtained from the zonelist_cache
1608 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1609 * Return true (non-zero) if zone is worth looking at further, or
1610 * else return false (zero) if it is not.
1612 * This check -ignores- the distinction between various watermarks,
1613 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1614 * found to be full for any variation of these watermarks, it will
1615 * be considered full for up to one second by all requests, unless
1616 * we are so low on memory on all allowed nodes that we are forced
1617 * into the second scan of the zonelist.
1619 * In the second scan we ignore this zonelist cache and exactly
1620 * apply the watermarks to all zones, even it is slower to do so.
1621 * We are low on memory in the second scan, and should leave no stone
1622 * unturned looking for a free page.
1624 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1625 nodemask_t *allowednodes)
1627 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1628 int i; /* index of *z in zonelist zones */
1629 int n; /* node that zone *z is on */
1631 zlc = zonelist->zlcache_ptr;
1635 i = z - zonelist->_zonerefs;
1638 /* This zone is worth trying if it is allowed but not full */
1639 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1643 * Given 'z' scanning a zonelist, set the corresponding bit in
1644 * zlc->fullzones, so that subsequent attempts to allocate a page
1645 * from that zone don't waste time re-examining it.
1647 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1649 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1650 int i; /* index of *z in zonelist zones */
1652 zlc = zonelist->zlcache_ptr;
1656 i = z - zonelist->_zonerefs;
1658 set_bit(i, zlc->fullzones);
1662 * clear all zones full, called after direct reclaim makes progress so that
1663 * a zone that was recently full is not skipped over for up to a second
1665 static void zlc_clear_zones_full(struct zonelist *zonelist)
1667 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1669 zlc = zonelist->zlcache_ptr;
1673 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1676 #else /* CONFIG_NUMA */
1678 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1683 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1684 nodemask_t *allowednodes)
1689 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1693 static void zlc_clear_zones_full(struct zonelist *zonelist)
1696 #endif /* CONFIG_NUMA */
1699 * get_page_from_freelist goes through the zonelist trying to allocate
1702 static struct page *
1703 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1704 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1705 struct zone *preferred_zone, int migratetype)
1708 struct page *page = NULL;
1711 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1712 int zlc_active = 0; /* set if using zonelist_cache */
1713 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1715 classzone_idx = zone_idx(preferred_zone);
1718 * Scan zonelist, looking for a zone with enough free.
1719 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1721 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1722 high_zoneidx, nodemask) {
1723 if (NUMA_BUILD && zlc_active &&
1724 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1726 if ((alloc_flags & ALLOC_CPUSET) &&
1727 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1730 * When allocating a page cache page for writing, we
1731 * want to get it from a zone that is within its dirty
1732 * limit, such that no single zone holds more than its
1733 * proportional share of globally allowed dirty pages.
1734 * The dirty limits take into account the zone's
1735 * lowmem reserves and high watermark so that kswapd
1736 * should be able to balance it without having to
1737 * write pages from its LRU list.
1739 * This may look like it could increase pressure on
1740 * lower zones by failing allocations in higher zones
1741 * before they are full. But the pages that do spill
1742 * over are limited as the lower zones are protected
1743 * by this very same mechanism. It should not become
1744 * a practical burden to them.
1746 * XXX: For now, allow allocations to potentially
1747 * exceed the per-zone dirty limit in the slowpath
1748 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1749 * which is important when on a NUMA setup the allowed
1750 * zones are together not big enough to reach the
1751 * global limit. The proper fix for these situations
1752 * will require awareness of zones in the
1753 * dirty-throttling and the flusher threads.
1755 if ((alloc_flags & ALLOC_WMARK_LOW) &&
1756 (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone))
1757 goto this_zone_full;
1759 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1760 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1764 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1765 if (zone_watermark_ok(zone, order, mark,
1766 classzone_idx, alloc_flags))
1769 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1771 * we do zlc_setup if there are multiple nodes
1772 * and before considering the first zone allowed
1775 allowednodes = zlc_setup(zonelist, alloc_flags);
1780 if (zone_reclaim_mode == 0)
1781 goto this_zone_full;
1784 * As we may have just activated ZLC, check if the first
1785 * eligible zone has failed zone_reclaim recently.
1787 if (NUMA_BUILD && zlc_active &&
1788 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1791 ret = zone_reclaim(zone, gfp_mask, order);
1793 case ZONE_RECLAIM_NOSCAN:
1796 case ZONE_RECLAIM_FULL:
1797 /* scanned but unreclaimable */
1800 /* did we reclaim enough */
1801 if (!zone_watermark_ok(zone, order, mark,
1802 classzone_idx, alloc_flags))
1803 goto this_zone_full;
1808 page = buffered_rmqueue(preferred_zone, zone, order,
1809 gfp_mask, migratetype);
1814 zlc_mark_zone_full(zonelist, z);
1817 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1818 /* Disable zlc cache for second zonelist scan */
1826 * Large machines with many possible nodes should not always dump per-node
1827 * meminfo in irq context.
1829 static inline bool should_suppress_show_mem(void)
1834 ret = in_interrupt();
1839 static DEFINE_RATELIMIT_STATE(nopage_rs,
1840 DEFAULT_RATELIMIT_INTERVAL,
1841 DEFAULT_RATELIMIT_BURST);
1843 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
1845 unsigned int filter = SHOW_MEM_FILTER_NODES;
1847 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
1848 debug_guardpage_minorder() > 0)
1852 * This documents exceptions given to allocations in certain
1853 * contexts that are allowed to allocate outside current's set
1856 if (!(gfp_mask & __GFP_NOMEMALLOC))
1857 if (test_thread_flag(TIF_MEMDIE) ||
1858 (current->flags & (PF_MEMALLOC | PF_EXITING)))
1859 filter &= ~SHOW_MEM_FILTER_NODES;
1860 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
1861 filter &= ~SHOW_MEM_FILTER_NODES;
1864 struct va_format vaf;
1867 va_start(args, fmt);
1872 pr_warn("%pV", &vaf);
1877 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
1878 current->comm, order, gfp_mask);
1881 if (!should_suppress_show_mem())
1886 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
1887 unsigned long did_some_progress,
1888 unsigned long pages_reclaimed)
1890 /* Do not loop if specifically requested */
1891 if (gfp_mask & __GFP_NORETRY)
1894 /* Always retry if specifically requested */
1895 if (gfp_mask & __GFP_NOFAIL)
1899 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
1900 * making forward progress without invoking OOM. Suspend also disables
1901 * storage devices so kswapd will not help. Bail if we are suspending.
1903 if (!did_some_progress && pm_suspended_storage())
1907 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1908 * means __GFP_NOFAIL, but that may not be true in other
1911 if (order <= PAGE_ALLOC_COSTLY_ORDER)
1915 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1916 * specified, then we retry until we no longer reclaim any pages
1917 * (above), or we've reclaimed an order of pages at least as
1918 * large as the allocation's order. In both cases, if the
1919 * allocation still fails, we stop retrying.
1921 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
1927 static inline struct page *
1928 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
1929 struct zonelist *zonelist, enum zone_type high_zoneidx,
1930 nodemask_t *nodemask, struct zone *preferred_zone,
1935 /* Acquire the OOM killer lock for the zones in zonelist */
1936 if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
1937 schedule_timeout_uninterruptible(1);
1942 * Go through the zonelist yet one more time, keep very high watermark
1943 * here, this is only to catch a parallel oom killing, we must fail if
1944 * we're still under heavy pressure.
1946 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
1947 order, zonelist, high_zoneidx,
1948 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1949 preferred_zone, migratetype);
1953 if (!(gfp_mask & __GFP_NOFAIL)) {
1954 /* The OOM killer will not help higher order allocs */
1955 if (order > PAGE_ALLOC_COSTLY_ORDER)
1957 /* The OOM killer does not needlessly kill tasks for lowmem */
1958 if (high_zoneidx < ZONE_NORMAL)
1961 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1962 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1963 * The caller should handle page allocation failure by itself if
1964 * it specifies __GFP_THISNODE.
1965 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1967 if (gfp_mask & __GFP_THISNODE)
1970 /* Exhausted what can be done so it's blamo time */
1971 out_of_memory(zonelist, gfp_mask, order, nodemask, false);
1974 clear_zonelist_oom(zonelist, gfp_mask);
1978 #ifdef CONFIG_COMPACTION
1979 /* Try memory compaction for high-order allocations before reclaim */
1980 static struct page *
1981 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
1982 struct zonelist *zonelist, enum zone_type high_zoneidx,
1983 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1984 int migratetype, bool sync_migration,
1985 bool *deferred_compaction,
1986 unsigned long *did_some_progress)
1993 if (compaction_deferred(preferred_zone, order)) {
1994 *deferred_compaction = true;
1998 current->flags |= PF_MEMALLOC;
1999 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2000 nodemask, sync_migration);
2001 current->flags &= ~PF_MEMALLOC;
2002 if (*did_some_progress != COMPACT_SKIPPED) {
2004 /* Page migration frees to the PCP lists but we want merging */
2005 drain_pages(get_cpu());
2008 page = get_page_from_freelist(gfp_mask, nodemask,
2009 order, zonelist, high_zoneidx,
2010 alloc_flags, preferred_zone,
2013 preferred_zone->compact_considered = 0;
2014 preferred_zone->compact_defer_shift = 0;
2015 if (order >= preferred_zone->compact_order_failed)
2016 preferred_zone->compact_order_failed = order + 1;
2017 count_vm_event(COMPACTSUCCESS);
2022 * It's bad if compaction run occurs and fails.
2023 * The most likely reason is that pages exist,
2024 * but not enough to satisfy watermarks.
2026 count_vm_event(COMPACTFAIL);
2029 * As async compaction considers a subset of pageblocks, only
2030 * defer if the failure was a sync compaction failure.
2033 defer_compaction(preferred_zone, order);
2041 static inline struct page *
2042 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2043 struct zonelist *zonelist, enum zone_type high_zoneidx,
2044 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2045 int migratetype, bool sync_migration,
2046 bool *deferred_compaction,
2047 unsigned long *did_some_progress)
2051 #endif /* CONFIG_COMPACTION */
2053 /* The really slow allocator path where we enter direct reclaim */
2054 static inline struct page *
2055 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2056 struct zonelist *zonelist, enum zone_type high_zoneidx,
2057 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2058 int migratetype, unsigned long *did_some_progress)
2060 struct page *page = NULL;
2061 struct reclaim_state reclaim_state;
2062 bool drained = false;
2066 /* We now go into synchronous reclaim */
2067 cpuset_memory_pressure_bump();
2068 current->flags |= PF_MEMALLOC;
2069 lockdep_set_current_reclaim_state(gfp_mask);
2070 reclaim_state.reclaimed_slab = 0;
2071 current->reclaim_state = &reclaim_state;
2073 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2075 current->reclaim_state = NULL;
2076 lockdep_clear_current_reclaim_state();
2077 current->flags &= ~PF_MEMALLOC;
2081 if (unlikely(!(*did_some_progress)))
2084 /* After successful reclaim, reconsider all zones for allocation */
2086 zlc_clear_zones_full(zonelist);
2089 page = get_page_from_freelist(gfp_mask, nodemask, order,
2090 zonelist, high_zoneidx,
2091 alloc_flags, preferred_zone,
2095 * If an allocation failed after direct reclaim, it could be because
2096 * pages are pinned on the per-cpu lists. Drain them and try again
2098 if (!page && !drained) {
2108 * This is called in the allocator slow-path if the allocation request is of
2109 * sufficient urgency to ignore watermarks and take other desperate measures
2111 static inline struct page *
2112 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2113 struct zonelist *zonelist, enum zone_type high_zoneidx,
2114 nodemask_t *nodemask, struct zone *preferred_zone,
2120 page = get_page_from_freelist(gfp_mask, nodemask, order,
2121 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2122 preferred_zone, migratetype);
2124 if (!page && gfp_mask & __GFP_NOFAIL)
2125 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2126 } while (!page && (gfp_mask & __GFP_NOFAIL));
2132 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2133 enum zone_type high_zoneidx,
2134 enum zone_type classzone_idx)
2139 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2140 wakeup_kswapd(zone, order, classzone_idx);
2144 gfp_to_alloc_flags(gfp_t gfp_mask)
2146 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2147 const gfp_t wait = gfp_mask & __GFP_WAIT;
2149 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2150 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2153 * The caller may dip into page reserves a bit more if the caller
2154 * cannot run direct reclaim, or if the caller has realtime scheduling
2155 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2156 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2158 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2162 * Not worth trying to allocate harder for
2163 * __GFP_NOMEMALLOC even if it can't schedule.
2165 if (!(gfp_mask & __GFP_NOMEMALLOC))
2166 alloc_flags |= ALLOC_HARDER;
2168 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2169 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2171 alloc_flags &= ~ALLOC_CPUSET;
2172 } else if (unlikely(rt_task(current)) && !in_interrupt())
2173 alloc_flags |= ALLOC_HARDER;
2175 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2176 if (!in_interrupt() &&
2177 ((current->flags & PF_MEMALLOC) ||
2178 unlikely(test_thread_flag(TIF_MEMDIE))))
2179 alloc_flags |= ALLOC_NO_WATERMARKS;
2185 static inline struct page *
2186 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2187 struct zonelist *zonelist, enum zone_type high_zoneidx,
2188 nodemask_t *nodemask, struct zone *preferred_zone,
2191 const gfp_t wait = gfp_mask & __GFP_WAIT;
2192 struct page *page = NULL;
2194 unsigned long pages_reclaimed = 0;
2195 unsigned long did_some_progress;
2196 bool sync_migration = false;
2197 bool deferred_compaction = false;
2200 * In the slowpath, we sanity check order to avoid ever trying to
2201 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2202 * be using allocators in order of preference for an area that is
2205 if (order >= MAX_ORDER) {
2206 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2211 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2212 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2213 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2214 * using a larger set of nodes after it has established that the
2215 * allowed per node queues are empty and that nodes are
2218 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2222 if (!(gfp_mask & __GFP_NO_KSWAPD))
2223 wake_all_kswapd(order, zonelist, high_zoneidx,
2224 zone_idx(preferred_zone));
2227 * OK, we're below the kswapd watermark and have kicked background
2228 * reclaim. Now things get more complex, so set up alloc_flags according
2229 * to how we want to proceed.
2231 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2234 * Find the true preferred zone if the allocation is unconstrained by
2237 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
2238 first_zones_zonelist(zonelist, high_zoneidx, NULL,
2242 /* This is the last chance, in general, before the goto nopage. */
2243 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2244 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2245 preferred_zone, migratetype);
2249 /* Allocate without watermarks if the context allows */
2250 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2251 page = __alloc_pages_high_priority(gfp_mask, order,
2252 zonelist, high_zoneidx, nodemask,
2253 preferred_zone, migratetype);
2258 /* Atomic allocations - we can't balance anything */
2262 /* Avoid recursion of direct reclaim */
2263 if (current->flags & PF_MEMALLOC)
2266 /* Avoid allocations with no watermarks from looping endlessly */
2267 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2271 * Try direct compaction. The first pass is asynchronous. Subsequent
2272 * attempts after direct reclaim are synchronous
2274 page = __alloc_pages_direct_compact(gfp_mask, order,
2275 zonelist, high_zoneidx,
2277 alloc_flags, preferred_zone,
2278 migratetype, sync_migration,
2279 &deferred_compaction,
2280 &did_some_progress);
2283 sync_migration = true;
2286 * If compaction is deferred for high-order allocations, it is because
2287 * sync compaction recently failed. In this is the case and the caller
2288 * has requested the system not be heavily disrupted, fail the
2289 * allocation now instead of entering direct reclaim
2291 if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
2294 /* Try direct reclaim and then allocating */
2295 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2296 zonelist, high_zoneidx,
2298 alloc_flags, preferred_zone,
2299 migratetype, &did_some_progress);
2304 * If we failed to make any progress reclaiming, then we are
2305 * running out of options and have to consider going OOM
2307 if (!did_some_progress) {
2308 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2309 if (oom_killer_disabled)
2311 /* Coredumps can quickly deplete all memory reserves */
2312 if ((current->flags & PF_DUMPCORE) &&
2313 !(gfp_mask & __GFP_NOFAIL))
2315 page = __alloc_pages_may_oom(gfp_mask, order,
2316 zonelist, high_zoneidx,
2317 nodemask, preferred_zone,
2322 if (!(gfp_mask & __GFP_NOFAIL)) {
2324 * The oom killer is not called for high-order
2325 * allocations that may fail, so if no progress
2326 * is being made, there are no other options and
2327 * retrying is unlikely to help.
2329 if (order > PAGE_ALLOC_COSTLY_ORDER)
2332 * The oom killer is not called for lowmem
2333 * allocations to prevent needlessly killing
2336 if (high_zoneidx < ZONE_NORMAL)
2344 /* Check if we should retry the allocation */
2345 pages_reclaimed += did_some_progress;
2346 if (should_alloc_retry(gfp_mask, order, did_some_progress,
2348 /* Wait for some write requests to complete then retry */
2349 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2353 * High-order allocations do not necessarily loop after
2354 * direct reclaim and reclaim/compaction depends on compaction
2355 * being called after reclaim so call directly if necessary
2357 page = __alloc_pages_direct_compact(gfp_mask, order,
2358 zonelist, high_zoneidx,
2360 alloc_flags, preferred_zone,
2361 migratetype, sync_migration,
2362 &deferred_compaction,
2363 &did_some_progress);
2369 warn_alloc_failed(gfp_mask, order, NULL);
2372 if (kmemcheck_enabled)
2373 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2379 * This is the 'heart' of the zoned buddy allocator.
2382 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2383 struct zonelist *zonelist, nodemask_t *nodemask)
2385 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2386 struct zone *preferred_zone;
2387 struct page *page = NULL;
2388 int migratetype = allocflags_to_migratetype(gfp_mask);
2389 unsigned int cpuset_mems_cookie;
2391 gfp_mask &= gfp_allowed_mask;
2393 lockdep_trace_alloc(gfp_mask);
2395 might_sleep_if(gfp_mask & __GFP_WAIT);
2397 if (should_fail_alloc_page(gfp_mask, order))
2401 * Check the zones suitable for the gfp_mask contain at least one
2402 * valid zone. It's possible to have an empty zonelist as a result
2403 * of GFP_THISNODE and a memoryless node
2405 if (unlikely(!zonelist->_zonerefs->zone))
2409 cpuset_mems_cookie = get_mems_allowed();
2411 /* The preferred zone is used for statistics later */
2412 first_zones_zonelist(zonelist, high_zoneidx,
2413 nodemask ? : &cpuset_current_mems_allowed,
2415 if (!preferred_zone)
2418 /* First allocation attempt */
2419 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2420 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
2421 preferred_zone, migratetype);
2422 if (unlikely(!page))
2423 page = __alloc_pages_slowpath(gfp_mask, order,
2424 zonelist, high_zoneidx, nodemask,
2425 preferred_zone, migratetype);
2427 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2431 * When updating a task's mems_allowed, it is possible to race with
2432 * parallel threads in such a way that an allocation can fail while
2433 * the mask is being updated. If a page allocation is about to fail,
2434 * check if the cpuset changed during allocation and if so, retry.
2436 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
2441 EXPORT_SYMBOL(__alloc_pages_nodemask);
2444 * Common helper functions.
2446 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2451 * __get_free_pages() returns a 32-bit address, which cannot represent
2454 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2456 page = alloc_pages(gfp_mask, order);
2459 return (unsigned long) page_address(page);
2461 EXPORT_SYMBOL(__get_free_pages);
2463 unsigned long get_zeroed_page(gfp_t gfp_mask)
2465 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2467 EXPORT_SYMBOL(get_zeroed_page);
2469 void __free_pages(struct page *page, unsigned int order)
2471 if (put_page_testzero(page)) {
2473 free_hot_cold_page(page, 0);
2475 __free_pages_ok(page, order);
2479 EXPORT_SYMBOL(__free_pages);
2481 void free_pages(unsigned long addr, unsigned int order)
2484 VM_BUG_ON(!virt_addr_valid((void *)addr));
2485 __free_pages(virt_to_page((void *)addr), order);
2489 EXPORT_SYMBOL(free_pages);
2491 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2494 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2495 unsigned long used = addr + PAGE_ALIGN(size);
2497 split_page(virt_to_page((void *)addr), order);
2498 while (used < alloc_end) {
2503 return (void *)addr;
2507 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2508 * @size: the number of bytes to allocate
2509 * @gfp_mask: GFP flags for the allocation
2511 * This function is similar to alloc_pages(), except that it allocates the
2512 * minimum number of pages to satisfy the request. alloc_pages() can only
2513 * allocate memory in power-of-two pages.
2515 * This function is also limited by MAX_ORDER.
2517 * Memory allocated by this function must be released by free_pages_exact().
2519 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2521 unsigned int order = get_order(size);
2524 addr = __get_free_pages(gfp_mask, order);
2525 return make_alloc_exact(addr, order, size);
2527 EXPORT_SYMBOL(alloc_pages_exact);
2530 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2532 * @nid: the preferred node ID where memory should be allocated
2533 * @size: the number of bytes to allocate
2534 * @gfp_mask: GFP flags for the allocation
2536 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2538 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2541 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2543 unsigned order = get_order(size);
2544 struct page *p = alloc_pages_node(nid, gfp_mask, order);
2547 return make_alloc_exact((unsigned long)page_address(p), order, size);
2549 EXPORT_SYMBOL(alloc_pages_exact_nid);
2552 * free_pages_exact - release memory allocated via alloc_pages_exact()
2553 * @virt: the value returned by alloc_pages_exact.
2554 * @size: size of allocation, same value as passed to alloc_pages_exact().
2556 * Release the memory allocated by a previous call to alloc_pages_exact.
2558 void free_pages_exact(void *virt, size_t size)
2560 unsigned long addr = (unsigned long)virt;
2561 unsigned long end = addr + PAGE_ALIGN(size);
2563 while (addr < end) {
2568 EXPORT_SYMBOL(free_pages_exact);
2570 static unsigned int nr_free_zone_pages(int offset)
2575 /* Just pick one node, since fallback list is circular */
2576 unsigned int sum = 0;
2578 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2580 for_each_zone_zonelist(zone, z, zonelist, offset) {
2581 unsigned long size = zone->present_pages;
2582 unsigned long high = high_wmark_pages(zone);
2591 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2593 unsigned int nr_free_buffer_pages(void)
2595 return nr_free_zone_pages(gfp_zone(GFP_USER));
2597 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2600 * Amount of free RAM allocatable within all zones
2602 unsigned int nr_free_pagecache_pages(void)
2604 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2607 static inline void show_node(struct zone *zone)
2610 printk("Node %d ", zone_to_nid(zone));
2613 void si_meminfo(struct sysinfo *val)
2615 val->totalram = totalram_pages;
2617 val->freeram = global_page_state(NR_FREE_PAGES);
2618 val->bufferram = nr_blockdev_pages();
2619 val->totalhigh = totalhigh_pages;
2620 val->freehigh = nr_free_highpages();
2621 val->mem_unit = PAGE_SIZE;
2624 EXPORT_SYMBOL(si_meminfo);
2627 void si_meminfo_node(struct sysinfo *val, int nid)
2629 pg_data_t *pgdat = NODE_DATA(nid);
2631 val->totalram = pgdat->node_present_pages;
2632 val->freeram = node_page_state(nid, NR_FREE_PAGES);
2633 #ifdef CONFIG_HIGHMEM
2634 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2635 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2641 val->mem_unit = PAGE_SIZE;
2646 * Determine whether the node should be displayed or not, depending on whether
2647 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2649 bool skip_free_areas_node(unsigned int flags, int nid)
2652 unsigned int cpuset_mems_cookie;
2654 if (!(flags & SHOW_MEM_FILTER_NODES))
2658 cpuset_mems_cookie = get_mems_allowed();
2659 ret = !node_isset(nid, cpuset_current_mems_allowed);
2660 } while (!put_mems_allowed(cpuset_mems_cookie));
2665 #define K(x) ((x) << (PAGE_SHIFT-10))
2668 * Show free area list (used inside shift_scroll-lock stuff)
2669 * We also calculate the percentage fragmentation. We do this by counting the
2670 * memory on each free list with the exception of the first item on the list.
2671 * Suppresses nodes that are not allowed by current's cpuset if
2672 * SHOW_MEM_FILTER_NODES is passed.
2674 void show_free_areas(unsigned int filter)
2679 for_each_populated_zone(zone) {
2680 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2683 printk("%s per-cpu:\n", zone->name);
2685 for_each_online_cpu(cpu) {
2686 struct per_cpu_pageset *pageset;
2688 pageset = per_cpu_ptr(zone->pageset, cpu);
2690 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2691 cpu, pageset->pcp.high,
2692 pageset->pcp.batch, pageset->pcp.count);
2696 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2697 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2699 " dirty:%lu writeback:%lu unstable:%lu\n"
2700 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2701 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2702 global_page_state(NR_ACTIVE_ANON),
2703 global_page_state(NR_INACTIVE_ANON),
2704 global_page_state(NR_ISOLATED_ANON),
2705 global_page_state(NR_ACTIVE_FILE),
2706 global_page_state(NR_INACTIVE_FILE),
2707 global_page_state(NR_ISOLATED_FILE),
2708 global_page_state(NR_UNEVICTABLE),
2709 global_page_state(NR_FILE_DIRTY),
2710 global_page_state(NR_WRITEBACK),
2711 global_page_state(NR_UNSTABLE_NFS),
2712 global_page_state(NR_FREE_PAGES),
2713 global_page_state(NR_SLAB_RECLAIMABLE),
2714 global_page_state(NR_SLAB_UNRECLAIMABLE),
2715 global_page_state(NR_FILE_MAPPED),
2716 global_page_state(NR_SHMEM),
2717 global_page_state(NR_PAGETABLE),
2718 global_page_state(NR_BOUNCE));
2720 for_each_populated_zone(zone) {
2723 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2731 " active_anon:%lukB"
2732 " inactive_anon:%lukB"
2733 " active_file:%lukB"
2734 " inactive_file:%lukB"
2735 " unevictable:%lukB"
2736 " isolated(anon):%lukB"
2737 " isolated(file):%lukB"
2744 " slab_reclaimable:%lukB"
2745 " slab_unreclaimable:%lukB"
2746 " kernel_stack:%lukB"
2750 " writeback_tmp:%lukB"
2751 " pages_scanned:%lu"
2752 " all_unreclaimable? %s"
2755 K(zone_page_state(zone, NR_FREE_PAGES)),
2756 K(min_wmark_pages(zone)),
2757 K(low_wmark_pages(zone)),
2758 K(high_wmark_pages(zone)),
2759 K(zone_page_state(zone, NR_ACTIVE_ANON)),
2760 K(zone_page_state(zone, NR_INACTIVE_ANON)),
2761 K(zone_page_state(zone, NR_ACTIVE_FILE)),
2762 K(zone_page_state(zone, NR_INACTIVE_FILE)),
2763 K(zone_page_state(zone, NR_UNEVICTABLE)),
2764 K(zone_page_state(zone, NR_ISOLATED_ANON)),
2765 K(zone_page_state(zone, NR_ISOLATED_FILE)),
2766 K(zone->present_pages),
2767 K(zone_page_state(zone, NR_MLOCK)),
2768 K(zone_page_state(zone, NR_FILE_DIRTY)),
2769 K(zone_page_state(zone, NR_WRITEBACK)),
2770 K(zone_page_state(zone, NR_FILE_MAPPED)),
2771 K(zone_page_state(zone, NR_SHMEM)),
2772 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
2773 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2774 zone_page_state(zone, NR_KERNEL_STACK) *
2776 K(zone_page_state(zone, NR_PAGETABLE)),
2777 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
2778 K(zone_page_state(zone, NR_BOUNCE)),
2779 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
2780 zone->pages_scanned,
2781 (zone->all_unreclaimable ? "yes" : "no")
2783 printk("lowmem_reserve[]:");
2784 for (i = 0; i < MAX_NR_ZONES; i++)
2785 printk(" %lu", zone->lowmem_reserve[i]);
2789 for_each_populated_zone(zone) {
2790 unsigned long nr[MAX_ORDER], flags, order, total = 0;
2792 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2795 printk("%s: ", zone->name);
2797 spin_lock_irqsave(&zone->lock, flags);
2798 for (order = 0; order < MAX_ORDER; order++) {
2799 nr[order] = zone->free_area[order].nr_free;
2800 total += nr[order] << order;
2802 spin_unlock_irqrestore(&zone->lock, flags);
2803 for (order = 0; order < MAX_ORDER; order++)
2804 printk("%lu*%lukB ", nr[order], K(1UL) << order);
2805 printk("= %lukB\n", K(total));
2808 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
2810 show_swap_cache_info();
2813 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
2815 zoneref->zone = zone;
2816 zoneref->zone_idx = zone_idx(zone);
2820 * Builds allocation fallback zone lists.
2822 * Add all populated zones of a node to the zonelist.
2824 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
2825 int nr_zones, enum zone_type zone_type)
2829 BUG_ON(zone_type >= MAX_NR_ZONES);
2834 zone = pgdat->node_zones + zone_type;
2835 if (populated_zone(zone)) {
2836 zoneref_set_zone(zone,
2837 &zonelist->_zonerefs[nr_zones++]);
2838 check_highest_zone(zone_type);
2841 } while (zone_type);
2848 * 0 = automatic detection of better ordering.
2849 * 1 = order by ([node] distance, -zonetype)
2850 * 2 = order by (-zonetype, [node] distance)
2852 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2853 * the same zonelist. So only NUMA can configure this param.
2855 #define ZONELIST_ORDER_DEFAULT 0
2856 #define ZONELIST_ORDER_NODE 1
2857 #define ZONELIST_ORDER_ZONE 2
2859 /* zonelist order in the kernel.
2860 * set_zonelist_order() will set this to NODE or ZONE.
2862 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
2863 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
2867 /* The value user specified ....changed by config */
2868 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2869 /* string for sysctl */
2870 #define NUMA_ZONELIST_ORDER_LEN 16
2871 char numa_zonelist_order[16] = "default";
2874 * interface for configure zonelist ordering.
2875 * command line option "numa_zonelist_order"
2876 * = "[dD]efault - default, automatic configuration.
2877 * = "[nN]ode - order by node locality, then by zone within node
2878 * = "[zZ]one - order by zone, then by locality within zone
2881 static int __parse_numa_zonelist_order(char *s)
2883 if (*s == 'd' || *s == 'D') {
2884 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2885 } else if (*s == 'n' || *s == 'N') {
2886 user_zonelist_order = ZONELIST_ORDER_NODE;
2887 } else if (*s == 'z' || *s == 'Z') {
2888 user_zonelist_order = ZONELIST_ORDER_ZONE;
2891 "Ignoring invalid numa_zonelist_order value: "
2898 static __init int setup_numa_zonelist_order(char *s)
2905 ret = __parse_numa_zonelist_order(s);
2907 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
2911 early_param("numa_zonelist_order", setup_numa_zonelist_order);
2914 * sysctl handler for numa_zonelist_order
2916 int numa_zonelist_order_handler(ctl_table *table, int write,
2917 void __user *buffer, size_t *length,
2920 char saved_string[NUMA_ZONELIST_ORDER_LEN];
2922 static DEFINE_MUTEX(zl_order_mutex);
2924 mutex_lock(&zl_order_mutex);
2926 strcpy(saved_string, (char*)table->data);
2927 ret = proc_dostring(table, write, buffer, length, ppos);
2931 int oldval = user_zonelist_order;
2932 if (__parse_numa_zonelist_order((char*)table->data)) {
2934 * bogus value. restore saved string
2936 strncpy((char*)table->data, saved_string,
2937 NUMA_ZONELIST_ORDER_LEN);
2938 user_zonelist_order = oldval;
2939 } else if (oldval != user_zonelist_order) {
2940 mutex_lock(&zonelists_mutex);
2941 build_all_zonelists(NULL);
2942 mutex_unlock(&zonelists_mutex);
2946 mutex_unlock(&zl_order_mutex);
2951 #define MAX_NODE_LOAD (nr_online_nodes)
2952 static int node_load[MAX_NUMNODES];
2955 * find_next_best_node - find the next node that should appear in a given node's fallback list
2956 * @node: node whose fallback list we're appending
2957 * @used_node_mask: nodemask_t of already used nodes
2959 * We use a number of factors to determine which is the next node that should
2960 * appear on a given node's fallback list. The node should not have appeared
2961 * already in @node's fallback list, and it should be the next closest node
2962 * according to the distance array (which contains arbitrary distance values
2963 * from each node to each node in the system), and should also prefer nodes
2964 * with no CPUs, since presumably they'll have very little allocation pressure
2965 * on them otherwise.
2966 * It returns -1 if no node is found.
2968 static int find_next_best_node(int node, nodemask_t *used_node_mask)
2971 int min_val = INT_MAX;
2973 const struct cpumask *tmp = cpumask_of_node(0);
2975 /* Use the local node if we haven't already */
2976 if (!node_isset(node, *used_node_mask)) {
2977 node_set(node, *used_node_mask);
2981 for_each_node_state(n, N_HIGH_MEMORY) {
2983 /* Don't want a node to appear more than once */
2984 if (node_isset(n, *used_node_mask))
2987 /* Use the distance array to find the distance */
2988 val = node_distance(node, n);
2990 /* Penalize nodes under us ("prefer the next node") */
2993 /* Give preference to headless and unused nodes */
2994 tmp = cpumask_of_node(n);
2995 if (!cpumask_empty(tmp))
2996 val += PENALTY_FOR_NODE_WITH_CPUS;
2998 /* Slight preference for less loaded node */
2999 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3000 val += node_load[n];
3002 if (val < min_val) {
3009 node_set(best_node, *used_node_mask);
3016 * Build zonelists ordered by node and zones within node.
3017 * This results in maximum locality--normal zone overflows into local
3018 * DMA zone, if any--but risks exhausting DMA zone.
3020 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3023 struct zonelist *zonelist;
3025 zonelist = &pgdat->node_zonelists[0];
3026 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3028 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3030 zonelist->_zonerefs[j].zone = NULL;
3031 zonelist->_zonerefs[j].zone_idx = 0;
3035 * Build gfp_thisnode zonelists
3037 static void build_thisnode_zonelists(pg_data_t *pgdat)
3040 struct zonelist *zonelist;
3042 zonelist = &pgdat->node_zonelists[1];
3043 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3044 zonelist->_zonerefs[j].zone = NULL;
3045 zonelist->_zonerefs[j].zone_idx = 0;
3049 * Build zonelists ordered by zone and nodes within zones.
3050 * This results in conserving DMA zone[s] until all Normal memory is
3051 * exhausted, but results in overflowing to remote node while memory
3052 * may still exist in local DMA zone.
3054 static int node_order[MAX_NUMNODES];
3056 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3059 int zone_type; /* needs to be signed */
3061 struct zonelist *zonelist;
3063 zonelist = &pgdat->node_zonelists[0];
3065 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3066 for (j = 0; j < nr_nodes; j++) {
3067 node = node_order[j];
3068 z = &NODE_DATA(node)->node_zones[zone_type];
3069 if (populated_zone(z)) {
3071 &zonelist->_zonerefs[pos++]);
3072 check_highest_zone(zone_type);
3076 zonelist->_zonerefs[pos].zone = NULL;
3077 zonelist->_zonerefs[pos].zone_idx = 0;
3080 static int default_zonelist_order(void)
3083 unsigned long low_kmem_size,total_size;
3087 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3088 * If they are really small and used heavily, the system can fall
3089 * into OOM very easily.
3090 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3092 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3095 for_each_online_node(nid) {
3096 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3097 z = &NODE_DATA(nid)->node_zones[zone_type];
3098 if (populated_zone(z)) {
3099 if (zone_type < ZONE_NORMAL)
3100 low_kmem_size += z->present_pages;
3101 total_size += z->present_pages;
3102 } else if (zone_type == ZONE_NORMAL) {
3104 * If any node has only lowmem, then node order
3105 * is preferred to allow kernel allocations
3106 * locally; otherwise, they can easily infringe
3107 * on other nodes when there is an abundance of
3108 * lowmem available to allocate from.
3110 return ZONELIST_ORDER_NODE;
3114 if (!low_kmem_size || /* there are no DMA area. */
3115 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
3116 return ZONELIST_ORDER_NODE;
3118 * look into each node's config.
3119 * If there is a node whose DMA/DMA32 memory is very big area on
3120 * local memory, NODE_ORDER may be suitable.
3122 average_size = total_size /
3123 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
3124 for_each_online_node(nid) {
3127 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3128 z = &NODE_DATA(nid)->node_zones[zone_type];
3129 if (populated_zone(z)) {
3130 if (zone_type < ZONE_NORMAL)
3131 low_kmem_size += z->present_pages;
3132 total_size += z->present_pages;
3135 if (low_kmem_size &&
3136 total_size > average_size && /* ignore small node */
3137 low_kmem_size > total_size * 70/100)
3138 return ZONELIST_ORDER_NODE;
3140 return ZONELIST_ORDER_ZONE;
3143 static void set_zonelist_order(void)
3145 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3146 current_zonelist_order = default_zonelist_order();
3148 current_zonelist_order = user_zonelist_order;
3151 static void build_zonelists(pg_data_t *pgdat)
3155 nodemask_t used_mask;
3156 int local_node, prev_node;
3157 struct zonelist *zonelist;
3158 int order = current_zonelist_order;
3160 /* initialize zonelists */
3161 for (i = 0; i < MAX_ZONELISTS; i++) {
3162 zonelist = pgdat->node_zonelists + i;
3163 zonelist->_zonerefs[0].zone = NULL;
3164 zonelist->_zonerefs[0].zone_idx = 0;
3167 /* NUMA-aware ordering of nodes */
3168 local_node = pgdat->node_id;
3169 load = nr_online_nodes;
3170 prev_node = local_node;
3171 nodes_clear(used_mask);
3173 memset(node_order, 0, sizeof(node_order));
3176 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3177 int distance = node_distance(local_node, node);
3180 * If another node is sufficiently far away then it is better
3181 * to reclaim pages in a zone before going off node.
3183 if (distance > RECLAIM_DISTANCE)
3184 zone_reclaim_mode = 1;
3187 * We don't want to pressure a particular node.
3188 * So adding penalty to the first node in same
3189 * distance group to make it round-robin.
3191 if (distance != node_distance(local_node, prev_node))
3192 node_load[node] = load;
3196 if (order == ZONELIST_ORDER_NODE)
3197 build_zonelists_in_node_order(pgdat, node);
3199 node_order[j++] = node; /* remember order */
3202 if (order == ZONELIST_ORDER_ZONE) {
3203 /* calculate node order -- i.e., DMA last! */
3204 build_zonelists_in_zone_order(pgdat, j);
3207 build_thisnode_zonelists(pgdat);
3210 /* Construct the zonelist performance cache - see further mmzone.h */
3211 static void build_zonelist_cache(pg_data_t *pgdat)
3213 struct zonelist *zonelist;
3214 struct zonelist_cache *zlc;
3217 zonelist = &pgdat->node_zonelists[0];
3218 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3219 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3220 for (z = zonelist->_zonerefs; z->zone; z++)
3221 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3224 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3226 * Return node id of node used for "local" allocations.
3227 * I.e., first node id of first zone in arg node's generic zonelist.
3228 * Used for initializing percpu 'numa_mem', which is used primarily
3229 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3231 int local_memory_node(int node)
3235 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3236 gfp_zone(GFP_KERNEL),
3243 #else /* CONFIG_NUMA */
3245 static void set_zonelist_order(void)
3247 current_zonelist_order = ZONELIST_ORDER_ZONE;
3250 static void build_zonelists(pg_data_t *pgdat)
3252 int node, local_node;
3254 struct zonelist *zonelist;
3256 local_node = pgdat->node_id;
3258 zonelist = &pgdat->node_zonelists[0];
3259 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3262 * Now we build the zonelist so that it contains the zones
3263 * of all the other nodes.
3264 * We don't want to pressure a particular node, so when
3265 * building the zones for node N, we make sure that the
3266 * zones coming right after the local ones are those from
3267 * node N+1 (modulo N)
3269 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3270 if (!node_online(node))
3272 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3275 for (node = 0; node < local_node; node++) {
3276 if (!node_online(node))
3278 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3282 zonelist->_zonerefs[j].zone = NULL;
3283 zonelist->_zonerefs[j].zone_idx = 0;
3286 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3287 static void build_zonelist_cache(pg_data_t *pgdat)
3289 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3292 #endif /* CONFIG_NUMA */
3295 * Boot pageset table. One per cpu which is going to be used for all
3296 * zones and all nodes. The parameters will be set in such a way
3297 * that an item put on a list will immediately be handed over to
3298 * the buddy list. This is safe since pageset manipulation is done
3299 * with interrupts disabled.
3301 * The boot_pagesets must be kept even after bootup is complete for
3302 * unused processors and/or zones. They do play a role for bootstrapping
3303 * hotplugged processors.
3305 * zoneinfo_show() and maybe other functions do
3306 * not check if the processor is online before following the pageset pointer.
3307 * Other parts of the kernel may not check if the zone is available.
3309 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3310 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3311 static void setup_zone_pageset(struct zone *zone);
3314 * Global mutex to protect against size modification of zonelists
3315 * as well as to serialize pageset setup for the new populated zone.
3317 DEFINE_MUTEX(zonelists_mutex);
3319 /* return values int ....just for stop_machine() */
3320 static __init_refok int __build_all_zonelists(void *data)
3326 memset(node_load, 0, sizeof(node_load));
3328 for_each_online_node(nid) {
3329 pg_data_t *pgdat = NODE_DATA(nid);
3331 build_zonelists(pgdat);
3332 build_zonelist_cache(pgdat);
3336 * Initialize the boot_pagesets that are going to be used
3337 * for bootstrapping processors. The real pagesets for
3338 * each zone will be allocated later when the per cpu
3339 * allocator is available.
3341 * boot_pagesets are used also for bootstrapping offline
3342 * cpus if the system is already booted because the pagesets
3343 * are needed to initialize allocators on a specific cpu too.
3344 * F.e. the percpu allocator needs the page allocator which
3345 * needs the percpu allocator in order to allocate its pagesets
3346 * (a chicken-egg dilemma).
3348 for_each_possible_cpu(cpu) {
3349 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3351 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3353 * We now know the "local memory node" for each node--
3354 * i.e., the node of the first zone in the generic zonelist.
3355 * Set up numa_mem percpu variable for on-line cpus. During
3356 * boot, only the boot cpu should be on-line; we'll init the
3357 * secondary cpus' numa_mem as they come on-line. During
3358 * node/memory hotplug, we'll fixup all on-line cpus.
3360 if (cpu_online(cpu))
3361 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3369 * Called with zonelists_mutex held always
3370 * unless system_state == SYSTEM_BOOTING.
3372 void __ref build_all_zonelists(void *data)
3374 set_zonelist_order();
3376 if (system_state == SYSTEM_BOOTING) {
3377 __build_all_zonelists(NULL);
3378 mminit_verify_zonelist();
3379 cpuset_init_current_mems_allowed();
3381 /* we have to stop all cpus to guarantee there is no user
3383 #ifdef CONFIG_MEMORY_HOTPLUG
3385 setup_zone_pageset((struct zone *)data);
3387 stop_machine(__build_all_zonelists, NULL, NULL);
3388 /* cpuset refresh routine should be here */
3390 vm_total_pages = nr_free_pagecache_pages();
3392 * Disable grouping by mobility if the number of pages in the
3393 * system is too low to allow the mechanism to work. It would be
3394 * more accurate, but expensive to check per-zone. This check is
3395 * made on memory-hotadd so a system can start with mobility
3396 * disabled and enable it later
3398 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3399 page_group_by_mobility_disabled = 1;
3401 page_group_by_mobility_disabled = 0;
3403 printk("Built %i zonelists in %s order, mobility grouping %s. "
3404 "Total pages: %ld\n",
3406 zonelist_order_name[current_zonelist_order],
3407 page_group_by_mobility_disabled ? "off" : "on",
3410 printk("Policy zone: %s\n", zone_names[policy_zone]);
3415 * Helper functions to size the waitqueue hash table.
3416 * Essentially these want to choose hash table sizes sufficiently
3417 * large so that collisions trying to wait on pages are rare.
3418 * But in fact, the number of active page waitqueues on typical
3419 * systems is ridiculously low, less than 200. So this is even
3420 * conservative, even though it seems large.
3422 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3423 * waitqueues, i.e. the size of the waitq table given the number of pages.
3425 #define PAGES_PER_WAITQUEUE 256
3427 #ifndef CONFIG_MEMORY_HOTPLUG
3428 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3430 unsigned long size = 1;
3432 pages /= PAGES_PER_WAITQUEUE;
3434 while (size < pages)
3438 * Once we have dozens or even hundreds of threads sleeping
3439 * on IO we've got bigger problems than wait queue collision.
3440 * Limit the size of the wait table to a reasonable size.
3442 size = min(size, 4096UL);
3444 return max(size, 4UL);
3448 * A zone's size might be changed by hot-add, so it is not possible to determine
3449 * a suitable size for its wait_table. So we use the maximum size now.
3451 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3453 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3454 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3455 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3457 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3458 * or more by the traditional way. (See above). It equals:
3460 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3461 * ia64(16K page size) : = ( 8G + 4M)byte.
3462 * powerpc (64K page size) : = (32G +16M)byte.
3464 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3471 * This is an integer logarithm so that shifts can be used later
3472 * to extract the more random high bits from the multiplicative
3473 * hash function before the remainder is taken.
3475 static inline unsigned long wait_table_bits(unsigned long size)
3480 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3483 * Check if a pageblock contains reserved pages
3485 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3489 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3490 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3497 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3498 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3499 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3500 * higher will lead to a bigger reserve which will get freed as contiguous
3501 * blocks as reclaim kicks in
3503 static void setup_zone_migrate_reserve(struct zone *zone)
3505 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3507 unsigned long block_migratetype;
3511 * Get the start pfn, end pfn and the number of blocks to reserve
3512 * We have to be careful to be aligned to pageblock_nr_pages to
3513 * make sure that we always check pfn_valid for the first page in
3516 start_pfn = zone->zone_start_pfn;
3517 end_pfn = start_pfn + zone->spanned_pages;
3518 start_pfn = roundup(start_pfn, pageblock_nr_pages);
3519 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3523 * Reserve blocks are generally in place to help high-order atomic
3524 * allocations that are short-lived. A min_free_kbytes value that
3525 * would result in more than 2 reserve blocks for atomic allocations
3526 * is assumed to be in place to help anti-fragmentation for the
3527 * future allocation of hugepages at runtime.
3529 reserve = min(2, reserve);
3531 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3532 if (!pfn_valid(pfn))
3534 page = pfn_to_page(pfn);
3536 /* Watch out for overlapping nodes */
3537 if (page_to_nid(page) != zone_to_nid(zone))
3540 block_migratetype = get_pageblock_migratetype(page);
3542 /* Only test what is necessary when the reserves are not met */
3545 * Blocks with reserved pages will never free, skip
3548 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
3549 if (pageblock_is_reserved(pfn, block_end_pfn))
3552 /* If this block is reserved, account for it */
3553 if (block_migratetype == MIGRATE_RESERVE) {
3558 /* Suitable for reserving if this block is movable */
3559 if (block_migratetype == MIGRATE_MOVABLE) {
3560 set_pageblock_migratetype(page,
3562 move_freepages_block(zone, page,
3570 * If the reserve is met and this is a previous reserved block,
3573 if (block_migratetype == MIGRATE_RESERVE) {
3574 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3575 move_freepages_block(zone, page, MIGRATE_MOVABLE);
3581 * Initially all pages are reserved - free ones are freed
3582 * up by free_all_bootmem() once the early boot process is
3583 * done. Non-atomic initialization, single-pass.
3585 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
3586 unsigned long start_pfn, enum memmap_context context)
3589 unsigned long end_pfn = start_pfn + size;
3593 if (highest_memmap_pfn < end_pfn - 1)
3594 highest_memmap_pfn = end_pfn - 1;
3596 z = &NODE_DATA(nid)->node_zones[zone];
3597 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3599 * There can be holes in boot-time mem_map[]s
3600 * handed to this function. They do not
3601 * exist on hotplugged memory.
3603 if (context == MEMMAP_EARLY) {
3604 if (!early_pfn_valid(pfn))
3606 if (!early_pfn_in_nid(pfn, nid))
3609 page = pfn_to_page(pfn);
3610 set_page_links(page, zone, nid, pfn);
3611 mminit_verify_page_links(page, zone, nid, pfn);
3612 init_page_count(page);
3613 reset_page_mapcount(page);
3614 SetPageReserved(page);
3616 * Mark the block movable so that blocks are reserved for
3617 * movable at startup. This will force kernel allocations
3618 * to reserve their blocks rather than leaking throughout
3619 * the address space during boot when many long-lived
3620 * kernel allocations are made. Later some blocks near
3621 * the start are marked MIGRATE_RESERVE by
3622 * setup_zone_migrate_reserve()
3624 * bitmap is created for zone's valid pfn range. but memmap
3625 * can be created for invalid pages (for alignment)
3626 * check here not to call set_pageblock_migratetype() against
3629 if ((z->zone_start_pfn <= pfn)
3630 && (pfn < z->zone_start_pfn + z->spanned_pages)
3631 && !(pfn & (pageblock_nr_pages - 1)))
3632 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3634 INIT_LIST_HEAD(&page->lru);
3635 #ifdef WANT_PAGE_VIRTUAL
3636 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3637 if (!is_highmem_idx(zone))
3638 set_page_address(page, __va(pfn << PAGE_SHIFT));
3643 static void __meminit zone_init_free_lists(struct zone *zone)
3646 for_each_migratetype_order(order, t) {
3647 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
3648 zone->free_area[order].nr_free = 0;
3652 #ifndef __HAVE_ARCH_MEMMAP_INIT
3653 #define memmap_init(size, nid, zone, start_pfn) \
3654 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3657 static int zone_batchsize(struct zone *zone)
3663 * The per-cpu-pages pools are set to around 1000th of the
3664 * size of the zone. But no more than 1/2 of a meg.
3666 * OK, so we don't know how big the cache is. So guess.
3668 batch = zone->present_pages / 1024;
3669 if (batch * PAGE_SIZE > 512 * 1024)
3670 batch = (512 * 1024) / PAGE_SIZE;
3671 batch /= 4; /* We effectively *= 4 below */
3676 * Clamp the batch to a 2^n - 1 value. Having a power
3677 * of 2 value was found to be more likely to have
3678 * suboptimal cache aliasing properties in some cases.
3680 * For example if 2 tasks are alternately allocating
3681 * batches of pages, one task can end up with a lot
3682 * of pages of one half of the possible page colors
3683 * and the other with pages of the other colors.
3685 batch = rounddown_pow_of_two(batch + batch/2) - 1;
3690 /* The deferral and batching of frees should be suppressed under NOMMU
3693 * The problem is that NOMMU needs to be able to allocate large chunks
3694 * of contiguous memory as there's no hardware page translation to
3695 * assemble apparent contiguous memory from discontiguous pages.
3697 * Queueing large contiguous runs of pages for batching, however,
3698 * causes the pages to actually be freed in smaller chunks. As there
3699 * can be a significant delay between the individual batches being
3700 * recycled, this leads to the once large chunks of space being
3701 * fragmented and becoming unavailable for high-order allocations.
3707 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3709 struct per_cpu_pages *pcp;
3712 memset(p, 0, sizeof(*p));
3716 pcp->high = 6 * batch;
3717 pcp->batch = max(1UL, 1 * batch);
3718 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
3719 INIT_LIST_HEAD(&pcp->lists[migratetype]);
3723 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3724 * to the value high for the pageset p.
3727 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
3730 struct per_cpu_pages *pcp;
3734 pcp->batch = max(1UL, high/4);
3735 if ((high/4) > (PAGE_SHIFT * 8))
3736 pcp->batch = PAGE_SHIFT * 8;
3739 static void setup_zone_pageset(struct zone *zone)
3743 zone->pageset = alloc_percpu(struct per_cpu_pageset);
3745 for_each_possible_cpu(cpu) {
3746 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
3748 setup_pageset(pcp, zone_batchsize(zone));
3750 if (percpu_pagelist_fraction)
3751 setup_pagelist_highmark(pcp,
3752 (zone->present_pages /
3753 percpu_pagelist_fraction));
3758 * Allocate per cpu pagesets and initialize them.
3759 * Before this call only boot pagesets were available.
3761 void __init setup_per_cpu_pageset(void)
3765 for_each_populated_zone(zone)
3766 setup_zone_pageset(zone);
3769 static noinline __init_refok
3770 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3773 struct pglist_data *pgdat = zone->zone_pgdat;
3777 * The per-page waitqueue mechanism uses hashed waitqueues
3780 zone->wait_table_hash_nr_entries =
3781 wait_table_hash_nr_entries(zone_size_pages);
3782 zone->wait_table_bits =
3783 wait_table_bits(zone->wait_table_hash_nr_entries);
3784 alloc_size = zone->wait_table_hash_nr_entries
3785 * sizeof(wait_queue_head_t);
3787 if (!slab_is_available()) {
3788 zone->wait_table = (wait_queue_head_t *)
3789 alloc_bootmem_node_nopanic(pgdat, alloc_size);
3792 * This case means that a zone whose size was 0 gets new memory
3793 * via memory hot-add.
3794 * But it may be the case that a new node was hot-added. In
3795 * this case vmalloc() will not be able to use this new node's
3796 * memory - this wait_table must be initialized to use this new
3797 * node itself as well.
3798 * To use this new node's memory, further consideration will be
3801 zone->wait_table = vmalloc(alloc_size);
3803 if (!zone->wait_table)
3806 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3807 init_waitqueue_head(zone->wait_table + i);
3812 static int __zone_pcp_update(void *data)
3814 struct zone *zone = data;
3816 unsigned long batch = zone_batchsize(zone), flags;
3818 for_each_possible_cpu(cpu) {
3819 struct per_cpu_pageset *pset;
3820 struct per_cpu_pages *pcp;
3822 pset = per_cpu_ptr(zone->pageset, cpu);
3825 local_irq_save(flags);
3826 free_pcppages_bulk(zone, pcp->count, pcp);
3827 setup_pageset(pset, batch);
3828 local_irq_restore(flags);
3833 void zone_pcp_update(struct zone *zone)
3835 stop_machine(__zone_pcp_update, zone, NULL);
3838 static __meminit void zone_pcp_init(struct zone *zone)
3841 * per cpu subsystem is not up at this point. The following code
3842 * relies on the ability of the linker to provide the
3843 * offset of a (static) per cpu variable into the per cpu area.
3845 zone->pageset = &boot_pageset;
3847 if (zone->present_pages)
3848 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
3849 zone->name, zone->present_pages,
3850 zone_batchsize(zone));
3853 __meminit int init_currently_empty_zone(struct zone *zone,
3854 unsigned long zone_start_pfn,
3856 enum memmap_context context)
3858 struct pglist_data *pgdat = zone->zone_pgdat;
3860 ret = zone_wait_table_init(zone, size);
3863 pgdat->nr_zones = zone_idx(zone) + 1;
3865 zone->zone_start_pfn = zone_start_pfn;
3867 mminit_dprintk(MMINIT_TRACE, "memmap_init",
3868 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3870 (unsigned long)zone_idx(zone),
3871 zone_start_pfn, (zone_start_pfn + size));
3873 zone_init_free_lists(zone);
3878 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
3879 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3881 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3882 * Architectures may implement their own version but if add_active_range()
3883 * was used and there are no special requirements, this is a convenient
3886 int __meminit __early_pfn_to_nid(unsigned long pfn)
3888 unsigned long start_pfn, end_pfn;
3891 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
3892 if (start_pfn <= pfn && pfn < end_pfn)
3894 /* This is a memory hole */
3897 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3899 int __meminit early_pfn_to_nid(unsigned long pfn)
3903 nid = __early_pfn_to_nid(pfn);
3906 /* just returns 0 */
3910 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3911 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
3915 nid = __early_pfn_to_nid(pfn);
3916 if (nid >= 0 && nid != node)
3923 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3924 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3925 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3927 * If an architecture guarantees that all ranges registered with
3928 * add_active_ranges() contain no holes and may be freed, this
3929 * this function may be used instead of calling free_bootmem() manually.
3931 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
3933 unsigned long start_pfn, end_pfn;
3936 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
3937 start_pfn = min(start_pfn, max_low_pfn);
3938 end_pfn = min(end_pfn, max_low_pfn);
3940 if (start_pfn < end_pfn)
3941 free_bootmem_node(NODE_DATA(this_nid),
3942 PFN_PHYS(start_pfn),
3943 (end_pfn - start_pfn) << PAGE_SHIFT);
3948 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3949 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3951 * If an architecture guarantees that all ranges registered with
3952 * add_active_ranges() contain no holes and may be freed, this
3953 * function may be used instead of calling memory_present() manually.
3955 void __init sparse_memory_present_with_active_regions(int nid)
3957 unsigned long start_pfn, end_pfn;
3960 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
3961 memory_present(this_nid, start_pfn, end_pfn);
3965 * get_pfn_range_for_nid - Return the start and end page frames for a node
3966 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3967 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3968 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3970 * It returns the start and end page frame of a node based on information
3971 * provided by an arch calling add_active_range(). If called for a node
3972 * with no available memory, a warning is printed and the start and end
3975 void __meminit get_pfn_range_for_nid(unsigned int nid,
3976 unsigned long *start_pfn, unsigned long *end_pfn)
3978 unsigned long this_start_pfn, this_end_pfn;
3984 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
3985 *start_pfn = min(*start_pfn, this_start_pfn);
3986 *end_pfn = max(*end_pfn, this_end_pfn);
3989 if (*start_pfn == -1UL)
3994 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3995 * assumption is made that zones within a node are ordered in monotonic
3996 * increasing memory addresses so that the "highest" populated zone is used
3998 static void __init find_usable_zone_for_movable(void)
4001 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4002 if (zone_index == ZONE_MOVABLE)
4005 if (arch_zone_highest_possible_pfn[zone_index] >
4006 arch_zone_lowest_possible_pfn[zone_index])
4010 VM_BUG_ON(zone_index == -1);
4011 movable_zone = zone_index;
4015 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4016 * because it is sized independent of architecture. Unlike the other zones,
4017 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4018 * in each node depending on the size of each node and how evenly kernelcore
4019 * is distributed. This helper function adjusts the zone ranges
4020 * provided by the architecture for a given node by using the end of the
4021 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4022 * zones within a node are in order of monotonic increases memory addresses
4024 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4025 unsigned long zone_type,
4026 unsigned long node_start_pfn,
4027 unsigned long node_end_pfn,
4028 unsigned long *zone_start_pfn,
4029 unsigned long *zone_end_pfn)
4031 /* Only adjust if ZONE_MOVABLE is on this node */
4032 if (zone_movable_pfn[nid]) {
4033 /* Size ZONE_MOVABLE */
4034 if (zone_type == ZONE_MOVABLE) {
4035 *zone_start_pfn = zone_movable_pfn[nid];
4036 *zone_end_pfn = min(node_end_pfn,
4037 arch_zone_highest_possible_pfn[movable_zone]);
4039 /* Adjust for ZONE_MOVABLE starting within this range */
4040 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4041 *zone_end_pfn > zone_movable_pfn[nid]) {
4042 *zone_end_pfn = zone_movable_pfn[nid];
4044 /* Check if this whole range is within ZONE_MOVABLE */
4045 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4046 *zone_start_pfn = *zone_end_pfn;
4051 * Return the number of pages a zone spans in a node, including holes
4052 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4054 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4055 unsigned long zone_type,
4056 unsigned long *ignored)
4058 unsigned long node_start_pfn, node_end_pfn;
4059 unsigned long zone_start_pfn, zone_end_pfn;
4061 /* Get the start and end of the node and zone */
4062 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4063 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4064 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4065 adjust_zone_range_for_zone_movable(nid, zone_type,
4066 node_start_pfn, node_end_pfn,
4067 &zone_start_pfn, &zone_end_pfn);
4069 /* Check that this node has pages within the zone's required range */
4070 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4073 /* Move the zone boundaries inside the node if necessary */
4074 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4075 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4077 /* Return the spanned pages */
4078 return zone_end_pfn - zone_start_pfn;
4082 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4083 * then all holes in the requested range will be accounted for.
4085 unsigned long __meminit __absent_pages_in_range(int nid,
4086 unsigned long range_start_pfn,
4087 unsigned long range_end_pfn)
4089 unsigned long nr_absent = range_end_pfn - range_start_pfn;
4090 unsigned long start_pfn, end_pfn;
4093 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4094 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4095 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4096 nr_absent -= end_pfn - start_pfn;
4102 * absent_pages_in_range - Return number of page frames in holes within a range
4103 * @start_pfn: The start PFN to start searching for holes
4104 * @end_pfn: The end PFN to stop searching for holes
4106 * It returns the number of pages frames in memory holes within a range.
4108 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4109 unsigned long end_pfn)
4111 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4114 /* Return the number of page frames in holes in a zone on a node */
4115 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4116 unsigned long zone_type,
4117 unsigned long *ignored)
4119 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4120 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4121 unsigned long node_start_pfn, node_end_pfn;
4122 unsigned long zone_start_pfn, zone_end_pfn;
4124 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4125 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4126 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4128 adjust_zone_range_for_zone_movable(nid, zone_type,
4129 node_start_pfn, node_end_pfn,
4130 &zone_start_pfn, &zone_end_pfn);
4131 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4134 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4135 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4136 unsigned long zone_type,
4137 unsigned long *zones_size)
4139 return zones_size[zone_type];
4142 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4143 unsigned long zone_type,
4144 unsigned long *zholes_size)
4149 return zholes_size[zone_type];
4152 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4154 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4155 unsigned long *zones_size, unsigned long *zholes_size)
4157 unsigned long realtotalpages, totalpages = 0;
4160 for (i = 0; i < MAX_NR_ZONES; i++)
4161 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4163 pgdat->node_spanned_pages = totalpages;
4165 realtotalpages = totalpages;
4166 for (i = 0; i < MAX_NR_ZONES; i++)
4168 zone_absent_pages_in_node(pgdat->node_id, i,
4170 pgdat->node_present_pages = realtotalpages;
4171 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4175 #ifndef CONFIG_SPARSEMEM
4177 * Calculate the size of the zone->blockflags rounded to an unsigned long
4178 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4179 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4180 * round what is now in bits to nearest long in bits, then return it in
4183 static unsigned long __init usemap_size(unsigned long zonesize)
4185 unsigned long usemapsize;
4187 usemapsize = roundup(zonesize, pageblock_nr_pages);
4188 usemapsize = usemapsize >> pageblock_order;
4189 usemapsize *= NR_PAGEBLOCK_BITS;
4190 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4192 return usemapsize / 8;
4195 static void __init setup_usemap(struct pglist_data *pgdat,
4196 struct zone *zone, unsigned long zonesize)
4198 unsigned long usemapsize = usemap_size(zonesize);
4199 zone->pageblock_flags = NULL;
4201 zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
4205 static inline void setup_usemap(struct pglist_data *pgdat,
4206 struct zone *zone, unsigned long zonesize) {}
4207 #endif /* CONFIG_SPARSEMEM */
4209 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4211 /* Return a sensible default order for the pageblock size. */
4212 static inline int pageblock_default_order(void)
4214 if (HPAGE_SHIFT > PAGE_SHIFT)
4215 return HUGETLB_PAGE_ORDER;
4220 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4221 static inline void __init set_pageblock_order(unsigned int order)
4223 /* Check that pageblock_nr_pages has not already been setup */
4224 if (pageblock_order)
4228 * Assume the largest contiguous order of interest is a huge page.
4229 * This value may be variable depending on boot parameters on IA64
4231 pageblock_order = order;
4233 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4236 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4237 * and pageblock_default_order() are unused as pageblock_order is set
4238 * at compile-time. See include/linux/pageblock-flags.h for the values of
4239 * pageblock_order based on the kernel config
4241 static inline int pageblock_default_order(unsigned int order)
4245 #define set_pageblock_order(x) do {} while (0)
4247 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4250 * Set up the zone data structures:
4251 * - mark all pages reserved
4252 * - mark all memory queues empty
4253 * - clear the memory bitmaps
4255 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4256 unsigned long *zones_size, unsigned long *zholes_size)
4259 int nid = pgdat->node_id;
4260 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4263 pgdat_resize_init(pgdat);
4264 pgdat->nr_zones = 0;
4265 init_waitqueue_head(&pgdat->kswapd_wait);
4266 pgdat->kswapd_max_order = 0;
4267 pgdat_page_cgroup_init(pgdat);
4269 for (j = 0; j < MAX_NR_ZONES; j++) {
4270 struct zone *zone = pgdat->node_zones + j;
4271 unsigned long size, realsize, memmap_pages;
4274 size = zone_spanned_pages_in_node(nid, j, zones_size);
4275 realsize = size - zone_absent_pages_in_node(nid, j,
4279 * Adjust realsize so that it accounts for how much memory
4280 * is used by this zone for memmap. This affects the watermark
4281 * and per-cpu initialisations
4284 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4285 if (realsize >= memmap_pages) {
4286 realsize -= memmap_pages;
4289 " %s zone: %lu pages used for memmap\n",
4290 zone_names[j], memmap_pages);
4293 " %s zone: %lu pages exceeds realsize %lu\n",
4294 zone_names[j], memmap_pages, realsize);
4296 /* Account for reserved pages */
4297 if (j == 0 && realsize > dma_reserve) {
4298 realsize -= dma_reserve;
4299 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4300 zone_names[0], dma_reserve);
4303 if (!is_highmem_idx(j))
4304 nr_kernel_pages += realsize;
4305 nr_all_pages += realsize;
4307 zone->spanned_pages = size;
4308 zone->present_pages = realsize;
4311 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4313 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4315 zone->name = zone_names[j];
4316 spin_lock_init(&zone->lock);
4317 spin_lock_init(&zone->lru_lock);
4318 zone_seqlock_init(zone);
4319 zone->zone_pgdat = pgdat;
4321 zone_pcp_init(zone);
4323 INIT_LIST_HEAD(&zone->lruvec.lists[lru]);
4324 zone->reclaim_stat.recent_rotated[0] = 0;
4325 zone->reclaim_stat.recent_rotated[1] = 0;
4326 zone->reclaim_stat.recent_scanned[0] = 0;
4327 zone->reclaim_stat.recent_scanned[1] = 0;
4328 zap_zone_vm_stats(zone);
4333 set_pageblock_order(pageblock_default_order());
4334 setup_usemap(pgdat, zone, size);
4335 ret = init_currently_empty_zone(zone, zone_start_pfn,
4336 size, MEMMAP_EARLY);
4338 memmap_init(size, nid, j, zone_start_pfn);
4339 zone_start_pfn += size;
4343 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4345 /* Skip empty nodes */
4346 if (!pgdat->node_spanned_pages)
4349 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4350 /* ia64 gets its own node_mem_map, before this, without bootmem */
4351 if (!pgdat->node_mem_map) {
4352 unsigned long size, start, end;
4356 * The zone's endpoints aren't required to be MAX_ORDER
4357 * aligned but the node_mem_map endpoints must be in order
4358 * for the buddy allocator to function correctly.
4360 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4361 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
4362 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4363 size = (end - start) * sizeof(struct page);
4364 map = alloc_remap(pgdat->node_id, size);
4366 map = alloc_bootmem_node_nopanic(pgdat, size);
4367 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4369 #ifndef CONFIG_NEED_MULTIPLE_NODES
4371 * With no DISCONTIG, the global mem_map is just set as node 0's
4373 if (pgdat == NODE_DATA(0)) {
4374 mem_map = NODE_DATA(0)->node_mem_map;
4375 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4376 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4377 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4378 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4381 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4384 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4385 unsigned long node_start_pfn, unsigned long *zholes_size)
4387 pg_data_t *pgdat = NODE_DATA(nid);
4389 pgdat->node_id = nid;
4390 pgdat->node_start_pfn = node_start_pfn;
4391 calculate_node_totalpages(pgdat, zones_size, zholes_size);
4393 alloc_node_mem_map(pgdat);
4394 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4395 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4396 nid, (unsigned long)pgdat,
4397 (unsigned long)pgdat->node_mem_map);
4400 free_area_init_core(pgdat, zones_size, zholes_size);
4403 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4405 #if MAX_NUMNODES > 1
4407 * Figure out the number of possible node ids.
4409 static void __init setup_nr_node_ids(void)
4412 unsigned int highest = 0;
4414 for_each_node_mask(node, node_possible_map)
4416 nr_node_ids = highest + 1;
4419 static inline void setup_nr_node_ids(void)
4425 * node_map_pfn_alignment - determine the maximum internode alignment
4427 * This function should be called after node map is populated and sorted.
4428 * It calculates the maximum power of two alignment which can distinguish
4431 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4432 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4433 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4434 * shifted, 1GiB is enough and this function will indicate so.
4436 * This is used to test whether pfn -> nid mapping of the chosen memory
4437 * model has fine enough granularity to avoid incorrect mapping for the
4438 * populated node map.
4440 * Returns the determined alignment in pfn's. 0 if there is no alignment
4441 * requirement (single node).
4443 unsigned long __init node_map_pfn_alignment(void)
4445 unsigned long accl_mask = 0, last_end = 0;
4446 unsigned long start, end, mask;
4450 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
4451 if (!start || last_nid < 0 || last_nid == nid) {
4458 * Start with a mask granular enough to pin-point to the
4459 * start pfn and tick off bits one-by-one until it becomes
4460 * too coarse to separate the current node from the last.
4462 mask = ~((1 << __ffs(start)) - 1);
4463 while (mask && last_end <= (start & (mask << 1)))
4466 /* accumulate all internode masks */
4470 /* convert mask to number of pages */
4471 return ~accl_mask + 1;
4474 /* Find the lowest pfn for a node */
4475 static unsigned long __init find_min_pfn_for_node(int nid)
4477 unsigned long min_pfn = ULONG_MAX;
4478 unsigned long start_pfn;
4481 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
4482 min_pfn = min(min_pfn, start_pfn);
4484 if (min_pfn == ULONG_MAX) {
4486 "Could not find start_pfn for node %d\n", nid);
4494 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4496 * It returns the minimum PFN based on information provided via
4497 * add_active_range().
4499 unsigned long __init find_min_pfn_with_active_regions(void)
4501 return find_min_pfn_for_node(MAX_NUMNODES);
4505 * early_calculate_totalpages()
4506 * Sum pages in active regions for movable zone.
4507 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4509 static unsigned long __init early_calculate_totalpages(void)
4511 unsigned long totalpages = 0;
4512 unsigned long start_pfn, end_pfn;
4515 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
4516 unsigned long pages = end_pfn - start_pfn;
4518 totalpages += pages;
4520 node_set_state(nid, N_HIGH_MEMORY);
4526 * Find the PFN the Movable zone begins in each node. Kernel memory
4527 * is spread evenly between nodes as long as the nodes have enough
4528 * memory. When they don't, some nodes will have more kernelcore than
4531 static void __init find_zone_movable_pfns_for_nodes(void)
4534 unsigned long usable_startpfn;
4535 unsigned long kernelcore_node, kernelcore_remaining;
4536 /* save the state before borrow the nodemask */
4537 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4538 unsigned long totalpages = early_calculate_totalpages();
4539 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
4542 * If movablecore was specified, calculate what size of
4543 * kernelcore that corresponds so that memory usable for
4544 * any allocation type is evenly spread. If both kernelcore
4545 * and movablecore are specified, then the value of kernelcore
4546 * will be used for required_kernelcore if it's greater than
4547 * what movablecore would have allowed.
4549 if (required_movablecore) {
4550 unsigned long corepages;
4553 * Round-up so that ZONE_MOVABLE is at least as large as what
4554 * was requested by the user
4556 required_movablecore =
4557 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4558 corepages = totalpages - required_movablecore;
4560 required_kernelcore = max(required_kernelcore, corepages);
4563 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4564 if (!required_kernelcore)
4567 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4568 find_usable_zone_for_movable();
4569 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4572 /* Spread kernelcore memory as evenly as possible throughout nodes */
4573 kernelcore_node = required_kernelcore / usable_nodes;
4574 for_each_node_state(nid, N_HIGH_MEMORY) {
4575 unsigned long start_pfn, end_pfn;
4578 * Recalculate kernelcore_node if the division per node
4579 * now exceeds what is necessary to satisfy the requested
4580 * amount of memory for the kernel
4582 if (required_kernelcore < kernelcore_node)
4583 kernelcore_node = required_kernelcore / usable_nodes;
4586 * As the map is walked, we track how much memory is usable
4587 * by the kernel using kernelcore_remaining. When it is
4588 * 0, the rest of the node is usable by ZONE_MOVABLE
4590 kernelcore_remaining = kernelcore_node;
4592 /* Go through each range of PFNs within this node */
4593 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4594 unsigned long size_pages;
4596 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
4597 if (start_pfn >= end_pfn)
4600 /* Account for what is only usable for kernelcore */
4601 if (start_pfn < usable_startpfn) {
4602 unsigned long kernel_pages;
4603 kernel_pages = min(end_pfn, usable_startpfn)
4606 kernelcore_remaining -= min(kernel_pages,
4607 kernelcore_remaining);
4608 required_kernelcore -= min(kernel_pages,
4609 required_kernelcore);
4611 /* Continue if range is now fully accounted */
4612 if (end_pfn <= usable_startpfn) {
4615 * Push zone_movable_pfn to the end so
4616 * that if we have to rebalance
4617 * kernelcore across nodes, we will
4618 * not double account here
4620 zone_movable_pfn[nid] = end_pfn;
4623 start_pfn = usable_startpfn;
4627 * The usable PFN range for ZONE_MOVABLE is from
4628 * start_pfn->end_pfn. Calculate size_pages as the
4629 * number of pages used as kernelcore
4631 size_pages = end_pfn - start_pfn;
4632 if (size_pages > kernelcore_remaining)
4633 size_pages = kernelcore_remaining;
4634 zone_movable_pfn[nid] = start_pfn + size_pages;
4637 * Some kernelcore has been met, update counts and
4638 * break if the kernelcore for this node has been
4641 required_kernelcore -= min(required_kernelcore,
4643 kernelcore_remaining -= size_pages;
4644 if (!kernelcore_remaining)
4650 * If there is still required_kernelcore, we do another pass with one
4651 * less node in the count. This will push zone_movable_pfn[nid] further
4652 * along on the nodes that still have memory until kernelcore is
4656 if (usable_nodes && required_kernelcore > usable_nodes)
4659 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4660 for (nid = 0; nid < MAX_NUMNODES; nid++)
4661 zone_movable_pfn[nid] =
4662 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4665 /* restore the node_state */
4666 node_states[N_HIGH_MEMORY] = saved_node_state;
4669 /* Any regular memory on that node ? */
4670 static void check_for_regular_memory(pg_data_t *pgdat)
4672 #ifdef CONFIG_HIGHMEM
4673 enum zone_type zone_type;
4675 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
4676 struct zone *zone = &pgdat->node_zones[zone_type];
4677 if (zone->present_pages) {
4678 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
4686 * free_area_init_nodes - Initialise all pg_data_t and zone data
4687 * @max_zone_pfn: an array of max PFNs for each zone
4689 * This will call free_area_init_node() for each active node in the system.
4690 * Using the page ranges provided by add_active_range(), the size of each
4691 * zone in each node and their holes is calculated. If the maximum PFN
4692 * between two adjacent zones match, it is assumed that the zone is empty.
4693 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4694 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4695 * starts where the previous one ended. For example, ZONE_DMA32 starts
4696 * at arch_max_dma_pfn.
4698 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
4700 unsigned long start_pfn, end_pfn;
4703 /* Record where the zone boundaries are */
4704 memset(arch_zone_lowest_possible_pfn, 0,
4705 sizeof(arch_zone_lowest_possible_pfn));
4706 memset(arch_zone_highest_possible_pfn, 0,
4707 sizeof(arch_zone_highest_possible_pfn));
4708 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
4709 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
4710 for (i = 1; i < MAX_NR_ZONES; i++) {
4711 if (i == ZONE_MOVABLE)
4713 arch_zone_lowest_possible_pfn[i] =
4714 arch_zone_highest_possible_pfn[i-1];
4715 arch_zone_highest_possible_pfn[i] =
4716 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
4718 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
4719 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
4721 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4722 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
4723 find_zone_movable_pfns_for_nodes();
4725 /* Print out the zone ranges */
4726 printk("Zone PFN ranges:\n");
4727 for (i = 0; i < MAX_NR_ZONES; i++) {
4728 if (i == ZONE_MOVABLE)
4730 printk(" %-8s ", zone_names[i]);
4731 if (arch_zone_lowest_possible_pfn[i] ==
4732 arch_zone_highest_possible_pfn[i])
4735 printk("%0#10lx -> %0#10lx\n",
4736 arch_zone_lowest_possible_pfn[i],
4737 arch_zone_highest_possible_pfn[i]);
4740 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4741 printk("Movable zone start PFN for each node\n");
4742 for (i = 0; i < MAX_NUMNODES; i++) {
4743 if (zone_movable_pfn[i])
4744 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
4747 /* Print out the early_node_map[] */
4748 printk("Early memory PFN ranges\n");
4749 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4750 printk(" %3d: %0#10lx -> %0#10lx\n", nid, start_pfn, end_pfn);
4752 /* Initialise every node */
4753 mminit_verify_pageflags_layout();
4754 setup_nr_node_ids();
4755 for_each_online_node(nid) {
4756 pg_data_t *pgdat = NODE_DATA(nid);
4757 free_area_init_node(nid, NULL,
4758 find_min_pfn_for_node(nid), NULL);
4760 /* Any memory on that node */
4761 if (pgdat->node_present_pages)
4762 node_set_state(nid, N_HIGH_MEMORY);
4763 check_for_regular_memory(pgdat);
4767 static int __init cmdline_parse_core(char *p, unsigned long *core)
4769 unsigned long long coremem;
4773 coremem = memparse(p, &p);
4774 *core = coremem >> PAGE_SHIFT;
4776 /* Paranoid check that UL is enough for the coremem value */
4777 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
4783 * kernelcore=size sets the amount of memory for use for allocations that
4784 * cannot be reclaimed or migrated.
4786 static int __init cmdline_parse_kernelcore(char *p)
4788 return cmdline_parse_core(p, &required_kernelcore);
4792 * movablecore=size sets the amount of memory for use for allocations that
4793 * can be reclaimed or migrated.
4795 static int __init cmdline_parse_movablecore(char *p)
4797 return cmdline_parse_core(p, &required_movablecore);
4800 early_param("kernelcore", cmdline_parse_kernelcore);
4801 early_param("movablecore", cmdline_parse_movablecore);
4803 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4806 * set_dma_reserve - set the specified number of pages reserved in the first zone
4807 * @new_dma_reserve: The number of pages to mark reserved
4809 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4810 * In the DMA zone, a significant percentage may be consumed by kernel image
4811 * and other unfreeable allocations which can skew the watermarks badly. This
4812 * function may optionally be used to account for unfreeable pages in the
4813 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4814 * smaller per-cpu batchsize.
4816 void __init set_dma_reserve(unsigned long new_dma_reserve)
4818 dma_reserve = new_dma_reserve;
4821 void __init free_area_init(unsigned long *zones_size)
4823 free_area_init_node(0, zones_size,
4824 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
4827 static int page_alloc_cpu_notify(struct notifier_block *self,
4828 unsigned long action, void *hcpu)
4830 int cpu = (unsigned long)hcpu;
4832 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4833 lru_add_drain_cpu(cpu);
4837 * Spill the event counters of the dead processor
4838 * into the current processors event counters.
4839 * This artificially elevates the count of the current
4842 vm_events_fold_cpu(cpu);
4845 * Zero the differential counters of the dead processor
4846 * so that the vm statistics are consistent.
4848 * This is only okay since the processor is dead and cannot
4849 * race with what we are doing.
4851 refresh_cpu_vm_stats(cpu);
4856 void __init page_alloc_init(void)
4858 hotcpu_notifier(page_alloc_cpu_notify, 0);
4862 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4863 * or min_free_kbytes changes.
4865 static void calculate_totalreserve_pages(void)
4867 struct pglist_data *pgdat;
4868 unsigned long reserve_pages = 0;
4869 enum zone_type i, j;
4871 for_each_online_pgdat(pgdat) {
4872 for (i = 0; i < MAX_NR_ZONES; i++) {
4873 struct zone *zone = pgdat->node_zones + i;
4874 unsigned long max = 0;
4876 /* Find valid and maximum lowmem_reserve in the zone */
4877 for (j = i; j < MAX_NR_ZONES; j++) {
4878 if (zone->lowmem_reserve[j] > max)
4879 max = zone->lowmem_reserve[j];
4882 /* we treat the high watermark as reserved pages. */
4883 max += high_wmark_pages(zone);
4885 if (max > zone->present_pages)
4886 max = zone->present_pages;
4887 reserve_pages += max;
4889 * Lowmem reserves are not available to
4890 * GFP_HIGHUSER page cache allocations and
4891 * kswapd tries to balance zones to their high
4892 * watermark. As a result, neither should be
4893 * regarded as dirtyable memory, to prevent a
4894 * situation where reclaim has to clean pages
4895 * in order to balance the zones.
4897 zone->dirty_balance_reserve = max;
4900 dirty_balance_reserve = reserve_pages;
4901 totalreserve_pages = reserve_pages;
4905 * setup_per_zone_lowmem_reserve - called whenever
4906 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4907 * has a correct pages reserved value, so an adequate number of
4908 * pages are left in the zone after a successful __alloc_pages().
4910 static void setup_per_zone_lowmem_reserve(void)
4912 struct pglist_data *pgdat;
4913 enum zone_type j, idx;
4915 for_each_online_pgdat(pgdat) {
4916 for (j = 0; j < MAX_NR_ZONES; j++) {
4917 struct zone *zone = pgdat->node_zones + j;
4918 unsigned long present_pages = zone->present_pages;
4920 zone->lowmem_reserve[j] = 0;
4924 struct zone *lower_zone;
4928 if (sysctl_lowmem_reserve_ratio[idx] < 1)
4929 sysctl_lowmem_reserve_ratio[idx] = 1;
4931 lower_zone = pgdat->node_zones + idx;
4932 lower_zone->lowmem_reserve[j] = present_pages /
4933 sysctl_lowmem_reserve_ratio[idx];
4934 present_pages += lower_zone->present_pages;
4939 /* update totalreserve_pages */
4940 calculate_totalreserve_pages();
4944 * setup_per_zone_wmarks - called when min_free_kbytes changes
4945 * or when memory is hot-{added|removed}
4947 * Ensures that the watermark[min,low,high] values for each zone are set
4948 * correctly with respect to min_free_kbytes.
4950 void setup_per_zone_wmarks(void)
4952 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
4953 unsigned long lowmem_pages = 0;
4955 unsigned long flags;
4957 /* Calculate total number of !ZONE_HIGHMEM pages */
4958 for_each_zone(zone) {
4959 if (!is_highmem(zone))
4960 lowmem_pages += zone->present_pages;
4963 for_each_zone(zone) {
4966 spin_lock_irqsave(&zone->lock, flags);
4967 tmp = (u64)pages_min * zone->present_pages;
4968 do_div(tmp, lowmem_pages);
4969 if (is_highmem(zone)) {
4971 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4972 * need highmem pages, so cap pages_min to a small
4975 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4976 * deltas controls asynch page reclaim, and so should
4977 * not be capped for highmem.
4981 min_pages = zone->present_pages / 1024;
4982 if (min_pages < SWAP_CLUSTER_MAX)
4983 min_pages = SWAP_CLUSTER_MAX;
4984 if (min_pages > 128)
4986 zone->watermark[WMARK_MIN] = min_pages;
4989 * If it's a lowmem zone, reserve a number of pages
4990 * proportionate to the zone's size.
4992 zone->watermark[WMARK_MIN] = tmp;
4995 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
4996 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4997 setup_zone_migrate_reserve(zone);
4998 spin_unlock_irqrestore(&zone->lock, flags);
5001 /* update totalreserve_pages */
5002 calculate_totalreserve_pages();
5006 * The inactive anon list should be small enough that the VM never has to
5007 * do too much work, but large enough that each inactive page has a chance
5008 * to be referenced again before it is swapped out.
5010 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5011 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5012 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5013 * the anonymous pages are kept on the inactive list.
5016 * memory ratio inactive anon
5017 * -------------------------------------
5026 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5028 unsigned int gb, ratio;
5030 /* Zone size in gigabytes */
5031 gb = zone->present_pages >> (30 - PAGE_SHIFT);
5033 ratio = int_sqrt(10 * gb);
5037 zone->inactive_ratio = ratio;
5040 static void __meminit setup_per_zone_inactive_ratio(void)
5045 calculate_zone_inactive_ratio(zone);
5049 * Initialise min_free_kbytes.
5051 * For small machines we want it small (128k min). For large machines
5052 * we want it large (64MB max). But it is not linear, because network
5053 * bandwidth does not increase linearly with machine size. We use
5055 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5056 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5072 int __meminit init_per_zone_wmark_min(void)
5074 unsigned long lowmem_kbytes;
5076 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5078 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5079 if (min_free_kbytes < 128)
5080 min_free_kbytes = 128;
5081 if (min_free_kbytes > 65536)
5082 min_free_kbytes = 65536;
5083 setup_per_zone_wmarks();
5084 refresh_zone_stat_thresholds();
5085 setup_per_zone_lowmem_reserve();
5086 setup_per_zone_inactive_ratio();
5089 module_init(init_per_zone_wmark_min)
5092 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5093 * that we can call two helper functions whenever min_free_kbytes
5096 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
5097 void __user *buffer, size_t *length, loff_t *ppos)
5099 proc_dointvec(table, write, buffer, length, ppos);
5101 setup_per_zone_wmarks();
5106 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5107 void __user *buffer, size_t *length, loff_t *ppos)
5112 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5117 zone->min_unmapped_pages = (zone->present_pages *
5118 sysctl_min_unmapped_ratio) / 100;
5122 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5123 void __user *buffer, size_t *length, loff_t *ppos)
5128 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5133 zone->min_slab_pages = (zone->present_pages *
5134 sysctl_min_slab_ratio) / 100;
5140 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5141 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5142 * whenever sysctl_lowmem_reserve_ratio changes.
5144 * The reserve ratio obviously has absolutely no relation with the
5145 * minimum watermarks. The lowmem reserve ratio can only make sense
5146 * if in function of the boot time zone sizes.
5148 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5149 void __user *buffer, size_t *length, loff_t *ppos)
5151 proc_dointvec_minmax(table, write, buffer, length, ppos);
5152 setup_per_zone_lowmem_reserve();
5157 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5158 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5159 * can have before it gets flushed back to buddy allocator.
5162 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
5163 void __user *buffer, size_t *length, loff_t *ppos)
5169 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5170 if (!write || (ret == -EINVAL))
5172 for_each_populated_zone(zone) {
5173 for_each_possible_cpu(cpu) {
5175 high = zone->present_pages / percpu_pagelist_fraction;
5176 setup_pagelist_highmark(
5177 per_cpu_ptr(zone->pageset, cpu), high);
5183 int hashdist = HASHDIST_DEFAULT;
5186 static int __init set_hashdist(char *str)
5190 hashdist = simple_strtoul(str, &str, 0);
5193 __setup("hashdist=", set_hashdist);
5197 * allocate a large system hash table from bootmem
5198 * - it is assumed that the hash table must contain an exact power-of-2
5199 * quantity of entries
5200 * - limit is the number of hash buckets, not the total allocation size
5202 void *__init alloc_large_system_hash(const char *tablename,
5203 unsigned long bucketsize,
5204 unsigned long numentries,
5207 unsigned int *_hash_shift,
5208 unsigned int *_hash_mask,
5209 unsigned long limit)
5211 unsigned long long max = limit;
5212 unsigned long log2qty, size;
5215 /* allow the kernel cmdline to have a say */
5217 /* round applicable memory size up to nearest megabyte */
5218 numentries = nr_kernel_pages;
5219 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
5220 numentries >>= 20 - PAGE_SHIFT;
5221 numentries <<= 20 - PAGE_SHIFT;
5223 /* limit to 1 bucket per 2^scale bytes of low memory */
5224 if (scale > PAGE_SHIFT)
5225 numentries >>= (scale - PAGE_SHIFT);
5227 numentries <<= (PAGE_SHIFT - scale);
5229 /* Make sure we've got at least a 0-order allocation.. */
5230 if (unlikely(flags & HASH_SMALL)) {
5231 /* Makes no sense without HASH_EARLY */
5232 WARN_ON(!(flags & HASH_EARLY));
5233 if (!(numentries >> *_hash_shift)) {
5234 numentries = 1UL << *_hash_shift;
5235 BUG_ON(!numentries);
5237 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5238 numentries = PAGE_SIZE / bucketsize;
5240 numentries = roundup_pow_of_two(numentries);
5242 /* limit allocation size to 1/16 total memory by default */
5244 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5245 do_div(max, bucketsize);
5247 max = min(max, 0x80000000ULL);
5249 if (numentries > max)
5252 log2qty = ilog2(numentries);
5255 size = bucketsize << log2qty;
5256 if (flags & HASH_EARLY)
5257 table = alloc_bootmem_nopanic(size);
5259 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
5262 * If bucketsize is not a power-of-two, we may free
5263 * some pages at the end of hash table which
5264 * alloc_pages_exact() automatically does
5266 if (get_order(size) < MAX_ORDER) {
5267 table = alloc_pages_exact(size, GFP_ATOMIC);
5268 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
5271 } while (!table && size > PAGE_SIZE && --log2qty);
5274 panic("Failed to allocate %s hash table\n", tablename);
5276 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
5279 ilog2(size) - PAGE_SHIFT,
5283 *_hash_shift = log2qty;
5285 *_hash_mask = (1 << log2qty) - 1;
5290 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5291 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
5294 #ifdef CONFIG_SPARSEMEM
5295 return __pfn_to_section(pfn)->pageblock_flags;
5297 return zone->pageblock_flags;
5298 #endif /* CONFIG_SPARSEMEM */
5301 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
5303 #ifdef CONFIG_SPARSEMEM
5304 pfn &= (PAGES_PER_SECTION-1);
5305 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5307 pfn = pfn - zone->zone_start_pfn;
5308 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5309 #endif /* CONFIG_SPARSEMEM */
5313 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5314 * @page: The page within the block of interest
5315 * @start_bitidx: The first bit of interest to retrieve
5316 * @end_bitidx: The last bit of interest
5317 * returns pageblock_bits flags
5319 unsigned long get_pageblock_flags_group(struct page *page,
5320 int start_bitidx, int end_bitidx)
5323 unsigned long *bitmap;
5324 unsigned long pfn, bitidx;
5325 unsigned long flags = 0;
5326 unsigned long value = 1;
5328 zone = page_zone(page);
5329 pfn = page_to_pfn(page);
5330 bitmap = get_pageblock_bitmap(zone, pfn);
5331 bitidx = pfn_to_bitidx(zone, pfn);
5333 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5334 if (test_bit(bitidx + start_bitidx, bitmap))
5341 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5342 * @page: The page within the block of interest
5343 * @start_bitidx: The first bit of interest
5344 * @end_bitidx: The last bit of interest
5345 * @flags: The flags to set
5347 void set_pageblock_flags_group(struct page *page, unsigned long flags,
5348 int start_bitidx, int end_bitidx)
5351 unsigned long *bitmap;
5352 unsigned long pfn, bitidx;
5353 unsigned long value = 1;
5355 zone = page_zone(page);
5356 pfn = page_to_pfn(page);
5357 bitmap = get_pageblock_bitmap(zone, pfn);
5358 bitidx = pfn_to_bitidx(zone, pfn);
5359 VM_BUG_ON(pfn < zone->zone_start_pfn);
5360 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5362 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5364 __set_bit(bitidx + start_bitidx, bitmap);
5366 __clear_bit(bitidx + start_bitidx, bitmap);
5370 * This is designed as sub function...plz see page_isolation.c also.
5371 * set/clear page block's type to be ISOLATE.
5372 * page allocater never alloc memory from ISOLATE block.
5376 __count_immobile_pages(struct zone *zone, struct page *page, int count)
5378 unsigned long pfn, iter, found;
5380 * For avoiding noise data, lru_add_drain_all() should be called
5381 * If ZONE_MOVABLE, the zone never contains immobile pages
5383 if (zone_idx(zone) == ZONE_MOVABLE)
5386 if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
5389 pfn = page_to_pfn(page);
5390 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
5391 unsigned long check = pfn + iter;
5393 if (!pfn_valid_within(check))
5396 page = pfn_to_page(check);
5397 if (!page_count(page)) {
5398 if (PageBuddy(page))
5399 iter += (1 << page_order(page)) - 1;
5405 * If there are RECLAIMABLE pages, we need to check it.
5406 * But now, memory offline itself doesn't call shrink_slab()
5407 * and it still to be fixed.
5410 * If the page is not RAM, page_count()should be 0.
5411 * we don't need more check. This is an _used_ not-movable page.
5413 * The problematic thing here is PG_reserved pages. PG_reserved
5414 * is set to both of a memory hole page and a _used_ kernel
5423 bool is_pageblock_removable_nolock(struct page *page)
5429 * We have to be careful here because we are iterating over memory
5430 * sections which are not zone aware so we might end up outside of
5431 * the zone but still within the section.
5432 * We have to take care about the node as well. If the node is offline
5433 * its NODE_DATA will be NULL - see page_zone.
5435 if (!node_online(page_to_nid(page)))
5438 zone = page_zone(page);
5439 pfn = page_to_pfn(page);
5440 if (zone->zone_start_pfn > pfn ||
5441 zone->zone_start_pfn + zone->spanned_pages <= pfn)
5444 return __count_immobile_pages(zone, page, 0);
5447 int set_migratetype_isolate(struct page *page)
5450 unsigned long flags, pfn;
5451 struct memory_isolate_notify arg;
5455 zone = page_zone(page);
5457 spin_lock_irqsave(&zone->lock, flags);
5459 pfn = page_to_pfn(page);
5460 arg.start_pfn = pfn;
5461 arg.nr_pages = pageblock_nr_pages;
5462 arg.pages_found = 0;
5465 * It may be possible to isolate a pageblock even if the
5466 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5467 * notifier chain is used by balloon drivers to return the
5468 * number of pages in a range that are held by the balloon
5469 * driver to shrink memory. If all the pages are accounted for
5470 * by balloons, are free, or on the LRU, isolation can continue.
5471 * Later, for example, when memory hotplug notifier runs, these
5472 * pages reported as "can be isolated" should be isolated(freed)
5473 * by the balloon driver through the memory notifier chain.
5475 notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
5476 notifier_ret = notifier_to_errno(notifier_ret);
5480 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5481 * We just check MOVABLE pages.
5483 if (__count_immobile_pages(zone, page, arg.pages_found))
5487 * immobile means "not-on-lru" paes. If immobile is larger than
5488 * removable-by-driver pages reported by notifier, we'll fail.
5493 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
5494 move_freepages_block(zone, page, MIGRATE_ISOLATE);
5497 spin_unlock_irqrestore(&zone->lock, flags);
5503 void unset_migratetype_isolate(struct page *page)
5506 unsigned long flags;
5507 zone = page_zone(page);
5508 spin_lock_irqsave(&zone->lock, flags);
5509 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
5511 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5512 move_freepages_block(zone, page, MIGRATE_MOVABLE);
5514 spin_unlock_irqrestore(&zone->lock, flags);
5517 #ifdef CONFIG_MEMORY_HOTREMOVE
5519 * All pages in the range must be isolated before calling this.
5522 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
5528 unsigned long flags;
5529 /* find the first valid pfn */
5530 for (pfn = start_pfn; pfn < end_pfn; pfn++)
5535 zone = page_zone(pfn_to_page(pfn));
5536 spin_lock_irqsave(&zone->lock, flags);
5538 while (pfn < end_pfn) {
5539 if (!pfn_valid(pfn)) {
5543 page = pfn_to_page(pfn);
5544 BUG_ON(page_count(page));
5545 BUG_ON(!PageBuddy(page));
5546 order = page_order(page);
5547 #ifdef CONFIG_DEBUG_VM
5548 printk(KERN_INFO "remove from free list %lx %d %lx\n",
5549 pfn, 1 << order, end_pfn);
5551 list_del(&page->lru);
5552 rmv_page_order(page);
5553 zone->free_area[order].nr_free--;
5554 __mod_zone_page_state(zone, NR_FREE_PAGES,
5556 for (i = 0; i < (1 << order); i++)
5557 SetPageReserved((page+i));
5558 pfn += (1 << order);
5560 spin_unlock_irqrestore(&zone->lock, flags);
5564 #ifdef CONFIG_MEMORY_FAILURE
5565 bool is_free_buddy_page(struct page *page)
5567 struct zone *zone = page_zone(page);
5568 unsigned long pfn = page_to_pfn(page);
5569 unsigned long flags;
5572 spin_lock_irqsave(&zone->lock, flags);
5573 for (order = 0; order < MAX_ORDER; order++) {
5574 struct page *page_head = page - (pfn & ((1 << order) - 1));
5576 if (PageBuddy(page_head) && page_order(page_head) >= order)
5579 spin_unlock_irqrestore(&zone->lock, flags);
5581 return order < MAX_ORDER;
5585 static struct trace_print_flags pageflag_names[] = {
5586 {1UL << PG_locked, "locked" },
5587 {1UL << PG_error, "error" },
5588 {1UL << PG_referenced, "referenced" },
5589 {1UL << PG_uptodate, "uptodate" },
5590 {1UL << PG_dirty, "dirty" },
5591 {1UL << PG_lru, "lru" },
5592 {1UL << PG_active, "active" },
5593 {1UL << PG_slab, "slab" },
5594 {1UL << PG_owner_priv_1, "owner_priv_1" },
5595 {1UL << PG_arch_1, "arch_1" },
5596 {1UL << PG_reserved, "reserved" },
5597 {1UL << PG_private, "private" },
5598 {1UL << PG_private_2, "private_2" },
5599 {1UL << PG_writeback, "writeback" },
5600 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5601 {1UL << PG_head, "head" },
5602 {1UL << PG_tail, "tail" },
5604 {1UL << PG_compound, "compound" },
5606 {1UL << PG_swapcache, "swapcache" },
5607 {1UL << PG_mappedtodisk, "mappedtodisk" },
5608 {1UL << PG_reclaim, "reclaim" },
5609 {1UL << PG_swapbacked, "swapbacked" },
5610 {1UL << PG_unevictable, "unevictable" },
5612 {1UL << PG_mlocked, "mlocked" },
5614 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5615 {1UL << PG_uncached, "uncached" },
5617 #ifdef CONFIG_MEMORY_FAILURE
5618 {1UL << PG_hwpoison, "hwpoison" },
5623 static void dump_page_flags(unsigned long flags)
5625 const char *delim = "";
5629 printk(KERN_ALERT "page flags: %#lx(", flags);
5631 /* remove zone id */
5632 flags &= (1UL << NR_PAGEFLAGS) - 1;
5634 for (i = 0; pageflag_names[i].name && flags; i++) {
5636 mask = pageflag_names[i].mask;
5637 if ((flags & mask) != mask)
5641 printk("%s%s", delim, pageflag_names[i].name);
5645 /* check for left over flags */
5647 printk("%s%#lx", delim, flags);
5652 void dump_page(struct page *page)
5655 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5656 page, atomic_read(&page->_count), page_mapcount(page),
5657 page->mapping, page->index);
5658 dump_page_flags(page->flags);
5659 mem_cgroup_print_bad_page(page);