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/compiler.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/suspend.h>
28 #include <linux/pagevec.h>
29 #include <linux/blkdev.h>
30 #include <linux/slab.h>
31 #include <linux/oom.h>
32 #include <linux/notifier.h>
33 #include <linux/topology.h>
34 #include <linux/sysctl.h>
35 #include <linux/cpu.h>
36 #include <linux/cpuset.h>
37 #include <linux/memory_hotplug.h>
38 #include <linux/nodemask.h>
39 #include <linux/vmalloc.h>
40 #include <linux/mempolicy.h>
41 #include <linux/stop_machine.h>
42 #include <linux/sort.h>
43 #include <linux/pfn.h>
44 #include <linux/backing-dev.h>
45 #include <linux/fault-inject.h>
46 #include <linux/page-isolation.h>
47 #include <linux/page_cgroup.h>
48 #include <linux/debugobjects.h>
49 #include <linux/kmemleak.h>
51 #include <asm/tlbflush.h>
52 #include <asm/div64.h>
56 * Array of node states.
58 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
59 [N_POSSIBLE] = NODE_MASK_ALL,
60 [N_ONLINE] = { { [0] = 1UL } },
62 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
64 [N_HIGH_MEMORY] = { { [0] = 1UL } },
66 [N_CPU] = { { [0] = 1UL } },
69 EXPORT_SYMBOL(node_states);
71 unsigned long totalram_pages __read_mostly;
72 unsigned long totalreserve_pages __read_mostly;
73 unsigned long highest_memmap_pfn __read_mostly;
74 int percpu_pagelist_fraction;
76 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
77 int pageblock_order __read_mostly;
80 static void __free_pages_ok(struct page *page, unsigned int order);
83 * results with 256, 32 in the lowmem_reserve sysctl:
84 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
85 * 1G machine -> (16M dma, 784M normal, 224M high)
86 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
87 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
88 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
90 * TBD: should special case ZONE_DMA32 machines here - in those we normally
91 * don't need any ZONE_NORMAL reservation
93 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
94 #ifdef CONFIG_ZONE_DMA
97 #ifdef CONFIG_ZONE_DMA32
100 #ifdef CONFIG_HIGHMEM
106 EXPORT_SYMBOL(totalram_pages);
108 static char * const zone_names[MAX_NR_ZONES] = {
109 #ifdef CONFIG_ZONE_DMA
112 #ifdef CONFIG_ZONE_DMA32
116 #ifdef CONFIG_HIGHMEM
122 int min_free_kbytes = 1024;
124 unsigned long __meminitdata nr_kernel_pages;
125 unsigned long __meminitdata nr_all_pages;
126 static unsigned long __meminitdata dma_reserve;
128 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
130 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
131 * ranges of memory (RAM) that may be registered with add_active_range().
132 * Ranges passed to add_active_range() will be merged if possible
133 * so the number of times add_active_range() can be called is
134 * related to the number of nodes and the number of holes
136 #ifdef CONFIG_MAX_ACTIVE_REGIONS
137 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
138 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
140 #if MAX_NUMNODES >= 32
141 /* If there can be many nodes, allow up to 50 holes per node */
142 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
144 /* By default, allow up to 256 distinct regions */
145 #define MAX_ACTIVE_REGIONS 256
149 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
150 static int __meminitdata nr_nodemap_entries;
151 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
152 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
153 static unsigned long __initdata required_kernelcore;
154 static unsigned long __initdata required_movablecore;
155 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
157 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
159 EXPORT_SYMBOL(movable_zone);
160 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
163 int nr_node_ids __read_mostly = MAX_NUMNODES;
164 int nr_online_nodes __read_mostly = 1;
165 EXPORT_SYMBOL(nr_node_ids);
166 EXPORT_SYMBOL(nr_online_nodes);
169 int page_group_by_mobility_disabled __read_mostly;
171 static void set_pageblock_migratetype(struct page *page, int migratetype)
174 if (unlikely(page_group_by_mobility_disabled))
175 migratetype = MIGRATE_UNMOVABLE;
177 set_pageblock_flags_group(page, (unsigned long)migratetype,
178 PB_migrate, PB_migrate_end);
181 bool oom_killer_disabled __read_mostly;
183 #ifdef CONFIG_DEBUG_VM
184 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
188 unsigned long pfn = page_to_pfn(page);
191 seq = zone_span_seqbegin(zone);
192 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
194 else if (pfn < zone->zone_start_pfn)
196 } while (zone_span_seqretry(zone, seq));
201 static int page_is_consistent(struct zone *zone, struct page *page)
203 if (!pfn_valid_within(page_to_pfn(page)))
205 if (zone != page_zone(page))
211 * Temporary debugging check for pages not lying within a given zone.
213 static int bad_range(struct zone *zone, struct page *page)
215 if (page_outside_zone_boundaries(zone, page))
217 if (!page_is_consistent(zone, page))
223 static inline int bad_range(struct zone *zone, struct page *page)
229 static void bad_page(struct page *page)
231 static unsigned long resume;
232 static unsigned long nr_shown;
233 static unsigned long nr_unshown;
236 * Allow a burst of 60 reports, then keep quiet for that minute;
237 * or allow a steady drip of one report per second.
239 if (nr_shown == 60) {
240 if (time_before(jiffies, resume)) {
246 "BUG: Bad page state: %lu messages suppressed\n",
253 resume = jiffies + 60 * HZ;
255 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
256 current->comm, page_to_pfn(page));
258 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
259 page, (void *)page->flags, page_count(page),
260 page_mapcount(page), page->mapping, page->index);
264 /* Leave bad fields for debug, except PageBuddy could make trouble */
265 __ClearPageBuddy(page);
266 add_taint(TAINT_BAD_PAGE);
270 * Higher-order pages are called "compound pages". They are structured thusly:
272 * The first PAGE_SIZE page is called the "head page".
274 * The remaining PAGE_SIZE pages are called "tail pages".
276 * All pages have PG_compound set. All pages have their ->private pointing at
277 * the head page (even the head page has this).
279 * The first tail page's ->lru.next holds the address of the compound page's
280 * put_page() function. Its ->lru.prev holds the order of allocation.
281 * This usage means that zero-order pages may not be compound.
284 static void free_compound_page(struct page *page)
286 __free_pages_ok(page, compound_order(page));
289 void prep_compound_page(struct page *page, unsigned long order)
292 int nr_pages = 1 << order;
294 set_compound_page_dtor(page, free_compound_page);
295 set_compound_order(page, order);
297 for (i = 1; i < nr_pages; i++) {
298 struct page *p = page + i;
301 p->first_page = page;
305 static int destroy_compound_page(struct page *page, unsigned long order)
308 int nr_pages = 1 << order;
311 if (unlikely(compound_order(page) != order) ||
312 unlikely(!PageHead(page))) {
317 __ClearPageHead(page);
319 for (i = 1; i < nr_pages; i++) {
320 struct page *p = page + i;
322 if (unlikely(!PageTail(p) || (p->first_page != page))) {
332 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
337 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
338 * and __GFP_HIGHMEM from hard or soft interrupt context.
340 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
341 for (i = 0; i < (1 << order); i++)
342 clear_highpage(page + i);
345 static inline void set_page_order(struct page *page, int order)
347 set_page_private(page, order);
348 __SetPageBuddy(page);
351 static inline void rmv_page_order(struct page *page)
353 __ClearPageBuddy(page);
354 set_page_private(page, 0);
358 * Locate the struct page for both the matching buddy in our
359 * pair (buddy1) and the combined O(n+1) page they form (page).
361 * 1) Any buddy B1 will have an order O twin B2 which satisfies
362 * the following equation:
364 * For example, if the starting buddy (buddy2) is #8 its order
366 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
368 * 2) Any buddy B will have an order O+1 parent P which
369 * satisfies the following equation:
372 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
374 static inline struct page *
375 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
377 unsigned long buddy_idx = page_idx ^ (1 << order);
379 return page + (buddy_idx - page_idx);
382 static inline unsigned long
383 __find_combined_index(unsigned long page_idx, unsigned int order)
385 return (page_idx & ~(1 << order));
389 * This function checks whether a page is free && is the buddy
390 * we can do coalesce a page and its buddy if
391 * (a) the buddy is not in a hole &&
392 * (b) the buddy is in the buddy system &&
393 * (c) a page and its buddy have the same order &&
394 * (d) a page and its buddy are in the same zone.
396 * For recording whether a page is in the buddy system, we use PG_buddy.
397 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
399 * For recording page's order, we use page_private(page).
401 static inline int page_is_buddy(struct page *page, struct page *buddy,
404 if (!pfn_valid_within(page_to_pfn(buddy)))
407 if (page_zone_id(page) != page_zone_id(buddy))
410 if (PageBuddy(buddy) && page_order(buddy) == order) {
411 VM_BUG_ON(page_count(buddy) != 0);
418 * Freeing function for a buddy system allocator.
420 * The concept of a buddy system is to maintain direct-mapped table
421 * (containing bit values) for memory blocks of various "orders".
422 * The bottom level table contains the map for the smallest allocatable
423 * units of memory (here, pages), and each level above it describes
424 * pairs of units from the levels below, hence, "buddies".
425 * At a high level, all that happens here is marking the table entry
426 * at the bottom level available, and propagating the changes upward
427 * as necessary, plus some accounting needed to play nicely with other
428 * parts of the VM system.
429 * At each level, we keep a list of pages, which are heads of continuous
430 * free pages of length of (1 << order) and marked with PG_buddy. Page's
431 * order is recorded in page_private(page) field.
432 * So when we are allocating or freeing one, we can derive the state of the
433 * other. That is, if we allocate a small block, and both were
434 * free, the remainder of the region must be split into blocks.
435 * If a block is freed, and its buddy is also free, then this
436 * triggers coalescing into a block of larger size.
441 static inline void __free_one_page(struct page *page,
442 struct zone *zone, unsigned int order,
445 unsigned long page_idx;
447 if (unlikely(PageCompound(page)))
448 if (unlikely(destroy_compound_page(page, order)))
451 VM_BUG_ON(migratetype == -1);
453 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
455 VM_BUG_ON(page_idx & ((1 << order) - 1));
456 VM_BUG_ON(bad_range(zone, page));
458 while (order < MAX_ORDER-1) {
459 unsigned long combined_idx;
462 buddy = __page_find_buddy(page, page_idx, order);
463 if (!page_is_buddy(page, buddy, order))
466 /* Our buddy is free, merge with it and move up one order. */
467 list_del(&buddy->lru);
468 zone->free_area[order].nr_free--;
469 rmv_page_order(buddy);
470 combined_idx = __find_combined_index(page_idx, order);
471 page = page + (combined_idx - page_idx);
472 page_idx = combined_idx;
475 set_page_order(page, order);
477 &zone->free_area[order].free_list[migratetype]);
478 zone->free_area[order].nr_free++;
481 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
483 * free_page_mlock() -- clean up attempts to free and mlocked() page.
484 * Page should not be on lru, so no need to fix that up.
485 * free_pages_check() will verify...
487 static inline void free_page_mlock(struct page *page)
489 __ClearPageMlocked(page);
490 __dec_zone_page_state(page, NR_MLOCK);
491 __count_vm_event(UNEVICTABLE_MLOCKFREED);
494 static void free_page_mlock(struct page *page) { }
497 static inline int free_pages_check(struct page *page)
499 if (unlikely(page_mapcount(page) |
500 (page->mapping != NULL) |
501 (atomic_read(&page->_count) != 0) |
502 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
506 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
507 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
512 * Frees a list of pages.
513 * Assumes all pages on list are in same zone, and of same order.
514 * count is the number of pages to free.
516 * If the zone was previously in an "all pages pinned" state then look to
517 * see if this freeing clears that state.
519 * And clear the zone's pages_scanned counter, to hold off the "all pages are
520 * pinned" detection logic.
522 static void free_pages_bulk(struct zone *zone, int count,
523 struct list_head *list, int order)
525 spin_lock(&zone->lock);
526 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
527 zone->pages_scanned = 0;
529 __mod_zone_page_state(zone, NR_FREE_PAGES, count << order);
533 VM_BUG_ON(list_empty(list));
534 page = list_entry(list->prev, struct page, lru);
535 /* have to delete it as __free_one_page list manipulates */
536 list_del(&page->lru);
537 __free_one_page(page, zone, order, page_private(page));
539 spin_unlock(&zone->lock);
542 static void free_one_page(struct zone *zone, struct page *page, int order,
545 spin_lock(&zone->lock);
546 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
547 zone->pages_scanned = 0;
549 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
550 __free_one_page(page, zone, order, migratetype);
551 spin_unlock(&zone->lock);
554 static void __free_pages_ok(struct page *page, unsigned int order)
559 int clearMlocked = PageMlocked(page);
561 for (i = 0 ; i < (1 << order) ; ++i)
562 bad += free_pages_check(page + i);
566 if (!PageHighMem(page)) {
567 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
568 debug_check_no_obj_freed(page_address(page),
571 arch_free_page(page, order);
572 kernel_map_pages(page, 1 << order, 0);
574 local_irq_save(flags);
575 if (unlikely(clearMlocked))
576 free_page_mlock(page);
577 __count_vm_events(PGFREE, 1 << order);
578 free_one_page(page_zone(page), page, order,
579 get_pageblock_migratetype(page));
580 local_irq_restore(flags);
584 * permit the bootmem allocator to evade page validation on high-order frees
586 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
589 __ClearPageReserved(page);
590 set_page_count(page, 0);
591 set_page_refcounted(page);
597 for (loop = 0; loop < BITS_PER_LONG; loop++) {
598 struct page *p = &page[loop];
600 if (loop + 1 < BITS_PER_LONG)
602 __ClearPageReserved(p);
603 set_page_count(p, 0);
606 set_page_refcounted(page);
607 __free_pages(page, order);
613 * The order of subdivision here is critical for the IO subsystem.
614 * Please do not alter this order without good reasons and regression
615 * testing. Specifically, as large blocks of memory are subdivided,
616 * the order in which smaller blocks are delivered depends on the order
617 * they're subdivided in this function. This is the primary factor
618 * influencing the order in which pages are delivered to the IO
619 * subsystem according to empirical testing, and this is also justified
620 * by considering the behavior of a buddy system containing a single
621 * large block of memory acted on by a series of small allocations.
622 * This behavior is a critical factor in sglist merging's success.
626 static inline void expand(struct zone *zone, struct page *page,
627 int low, int high, struct free_area *area,
630 unsigned long size = 1 << high;
636 VM_BUG_ON(bad_range(zone, &page[size]));
637 list_add(&page[size].lru, &area->free_list[migratetype]);
639 set_page_order(&page[size], high);
644 * This page is about to be returned from the page allocator
646 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
648 if (unlikely(page_mapcount(page) |
649 (page->mapping != NULL) |
650 (atomic_read(&page->_count) != 0) |
651 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
656 set_page_private(page, 0);
657 set_page_refcounted(page);
659 arch_alloc_page(page, order);
660 kernel_map_pages(page, 1 << order, 1);
662 if (gfp_flags & __GFP_ZERO)
663 prep_zero_page(page, order, gfp_flags);
665 if (order && (gfp_flags & __GFP_COMP))
666 prep_compound_page(page, order);
672 * Go through the free lists for the given migratetype and remove
673 * the smallest available page from the freelists
676 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
679 unsigned int current_order;
680 struct free_area * area;
683 /* Find a page of the appropriate size in the preferred list */
684 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
685 area = &(zone->free_area[current_order]);
686 if (list_empty(&area->free_list[migratetype]))
689 page = list_entry(area->free_list[migratetype].next,
691 list_del(&page->lru);
692 rmv_page_order(page);
694 expand(zone, page, order, current_order, area, migratetype);
703 * This array describes the order lists are fallen back to when
704 * the free lists for the desirable migrate type are depleted
706 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
707 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
708 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
709 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
710 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
714 * Move the free pages in a range to the free lists of the requested type.
715 * Note that start_page and end_pages are not aligned on a pageblock
716 * boundary. If alignment is required, use move_freepages_block()
718 static int move_freepages(struct zone *zone,
719 struct page *start_page, struct page *end_page,
726 #ifndef CONFIG_HOLES_IN_ZONE
728 * page_zone is not safe to call in this context when
729 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
730 * anyway as we check zone boundaries in move_freepages_block().
731 * Remove at a later date when no bug reports exist related to
732 * grouping pages by mobility
734 BUG_ON(page_zone(start_page) != page_zone(end_page));
737 for (page = start_page; page <= end_page;) {
738 /* Make sure we are not inadvertently changing nodes */
739 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
741 if (!pfn_valid_within(page_to_pfn(page))) {
746 if (!PageBuddy(page)) {
751 order = page_order(page);
752 list_del(&page->lru);
754 &zone->free_area[order].free_list[migratetype]);
756 pages_moved += 1 << order;
762 static int move_freepages_block(struct zone *zone, struct page *page,
765 unsigned long start_pfn, end_pfn;
766 struct page *start_page, *end_page;
768 start_pfn = page_to_pfn(page);
769 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
770 start_page = pfn_to_page(start_pfn);
771 end_page = start_page + pageblock_nr_pages - 1;
772 end_pfn = start_pfn + pageblock_nr_pages - 1;
774 /* Do not cross zone boundaries */
775 if (start_pfn < zone->zone_start_pfn)
777 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
780 return move_freepages(zone, start_page, end_page, migratetype);
783 /* Remove an element from the buddy allocator from the fallback list */
784 static inline struct page *
785 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
787 struct free_area * area;
792 /* Find the largest possible block of pages in the other list */
793 for (current_order = MAX_ORDER-1; current_order >= order;
795 for (i = 0; i < MIGRATE_TYPES - 1; i++) {
796 migratetype = fallbacks[start_migratetype][i];
798 /* MIGRATE_RESERVE handled later if necessary */
799 if (migratetype == MIGRATE_RESERVE)
802 area = &(zone->free_area[current_order]);
803 if (list_empty(&area->free_list[migratetype]))
806 page = list_entry(area->free_list[migratetype].next,
811 * If breaking a large block of pages, move all free
812 * pages to the preferred allocation list. If falling
813 * back for a reclaimable kernel allocation, be more
814 * agressive about taking ownership of free pages
816 if (unlikely(current_order >= (pageblock_order >> 1)) ||
817 start_migratetype == MIGRATE_RECLAIMABLE) {
819 pages = move_freepages_block(zone, page,
822 /* Claim the whole block if over half of it is free */
823 if (pages >= (1 << (pageblock_order-1)))
824 set_pageblock_migratetype(page,
827 migratetype = start_migratetype;
830 /* Remove the page from the freelists */
831 list_del(&page->lru);
832 rmv_page_order(page);
834 if (current_order == pageblock_order)
835 set_pageblock_migratetype(page,
838 expand(zone, page, order, current_order, area, migratetype);
847 * Do the hard work of removing an element from the buddy allocator.
848 * Call me with the zone->lock already held.
850 static struct page *__rmqueue(struct zone *zone, unsigned int order,
856 page = __rmqueue_smallest(zone, order, migratetype);
858 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
859 page = __rmqueue_fallback(zone, order, migratetype);
862 * Use MIGRATE_RESERVE rather than fail an allocation. goto
863 * is used because __rmqueue_smallest is an inline function
864 * and we want just one call site
867 migratetype = MIGRATE_RESERVE;
876 * Obtain a specified number of elements from the buddy allocator, all under
877 * a single hold of the lock, for efficiency. Add them to the supplied list.
878 * Returns the number of new pages which were placed at *list.
880 static int rmqueue_bulk(struct zone *zone, unsigned int order,
881 unsigned long count, struct list_head *list,
886 spin_lock(&zone->lock);
887 for (i = 0; i < count; ++i) {
888 struct page *page = __rmqueue(zone, order, migratetype);
889 if (unlikely(page == NULL))
893 * Split buddy pages returned by expand() are received here
894 * in physical page order. The page is added to the callers and
895 * list and the list head then moves forward. From the callers
896 * perspective, the linked list is ordered by page number in
897 * some conditions. This is useful for IO devices that can
898 * merge IO requests if the physical pages are ordered
901 list_add(&page->lru, list);
902 set_page_private(page, migratetype);
905 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
906 spin_unlock(&zone->lock);
912 * Called from the vmstat counter updater to drain pagesets of this
913 * currently executing processor on remote nodes after they have
916 * Note that this function must be called with the thread pinned to
917 * a single processor.
919 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
924 local_irq_save(flags);
925 if (pcp->count >= pcp->batch)
926 to_drain = pcp->batch;
928 to_drain = pcp->count;
929 free_pages_bulk(zone, to_drain, &pcp->list, 0);
930 pcp->count -= to_drain;
931 local_irq_restore(flags);
936 * Drain pages of the indicated processor.
938 * The processor must either be the current processor and the
939 * thread pinned to the current processor or a processor that
942 static void drain_pages(unsigned int cpu)
947 for_each_populated_zone(zone) {
948 struct per_cpu_pageset *pset;
949 struct per_cpu_pages *pcp;
951 pset = zone_pcp(zone, cpu);
954 local_irq_save(flags);
955 free_pages_bulk(zone, pcp->count, &pcp->list, 0);
957 local_irq_restore(flags);
962 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
964 void drain_local_pages(void *arg)
966 drain_pages(smp_processor_id());
970 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
972 void drain_all_pages(void)
974 on_each_cpu(drain_local_pages, NULL, 1);
977 #ifdef CONFIG_HIBERNATION
979 void mark_free_pages(struct zone *zone)
981 unsigned long pfn, max_zone_pfn;
984 struct list_head *curr;
986 if (!zone->spanned_pages)
989 spin_lock_irqsave(&zone->lock, flags);
991 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
992 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
993 if (pfn_valid(pfn)) {
994 struct page *page = pfn_to_page(pfn);
996 if (!swsusp_page_is_forbidden(page))
997 swsusp_unset_page_free(page);
1000 for_each_migratetype_order(order, t) {
1001 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1004 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1005 for (i = 0; i < (1UL << order); i++)
1006 swsusp_set_page_free(pfn_to_page(pfn + i));
1009 spin_unlock_irqrestore(&zone->lock, flags);
1011 #endif /* CONFIG_PM */
1014 * Free a 0-order page
1016 static void free_hot_cold_page(struct page *page, int cold)
1018 struct zone *zone = page_zone(page);
1019 struct per_cpu_pages *pcp;
1020 unsigned long flags;
1021 int clearMlocked = PageMlocked(page);
1024 page->mapping = NULL;
1025 if (free_pages_check(page))
1028 if (!PageHighMem(page)) {
1029 debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1030 debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
1032 arch_free_page(page, 0);
1033 kernel_map_pages(page, 1, 0);
1035 pcp = &zone_pcp(zone, get_cpu())->pcp;
1036 set_page_private(page, get_pageblock_migratetype(page));
1037 local_irq_save(flags);
1038 if (unlikely(clearMlocked))
1039 free_page_mlock(page);
1040 __count_vm_event(PGFREE);
1043 list_add_tail(&page->lru, &pcp->list);
1045 list_add(&page->lru, &pcp->list);
1047 if (pcp->count >= pcp->high) {
1048 free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
1049 pcp->count -= pcp->batch;
1051 local_irq_restore(flags);
1055 void free_hot_page(struct page *page)
1057 free_hot_cold_page(page, 0);
1060 void free_cold_page(struct page *page)
1062 free_hot_cold_page(page, 1);
1066 * split_page takes a non-compound higher-order page, and splits it into
1067 * n (1<<order) sub-pages: page[0..n]
1068 * Each sub-page must be freed individually.
1070 * Note: this is probably too low level an operation for use in drivers.
1071 * Please consult with lkml before using this in your driver.
1073 void split_page(struct page *page, unsigned int order)
1077 VM_BUG_ON(PageCompound(page));
1078 VM_BUG_ON(!page_count(page));
1079 for (i = 1; i < (1 << order); i++)
1080 set_page_refcounted(page + i);
1084 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1085 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1089 struct page *buffered_rmqueue(struct zone *preferred_zone,
1090 struct zone *zone, int order, gfp_t gfp_flags,
1093 unsigned long flags;
1095 int cold = !!(gfp_flags & __GFP_COLD);
1100 if (likely(order == 0)) {
1101 struct per_cpu_pages *pcp;
1103 pcp = &zone_pcp(zone, cpu)->pcp;
1104 local_irq_save(flags);
1106 pcp->count = rmqueue_bulk(zone, 0,
1107 pcp->batch, &pcp->list, migratetype);
1108 if (unlikely(!pcp->count))
1112 /* Find a page of the appropriate migrate type */
1114 list_for_each_entry_reverse(page, &pcp->list, lru)
1115 if (page_private(page) == migratetype)
1118 list_for_each_entry(page, &pcp->list, lru)
1119 if (page_private(page) == migratetype)
1123 /* Allocate more to the pcp list if necessary */
1124 if (unlikely(&page->lru == &pcp->list)) {
1125 pcp->count += rmqueue_bulk(zone, 0,
1126 pcp->batch, &pcp->list, migratetype);
1127 page = list_entry(pcp->list.next, struct page, lru);
1130 list_del(&page->lru);
1133 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1135 * __GFP_NOFAIL is not to be used in new code.
1137 * All __GFP_NOFAIL callers should be fixed so that they
1138 * properly detect and handle allocation failures.
1140 * We most definitely don't want callers attempting to
1141 * allocate greater than single-page units with
1144 WARN_ON_ONCE(order > 0);
1146 spin_lock_irqsave(&zone->lock, flags);
1147 page = __rmqueue(zone, order, migratetype);
1148 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
1149 spin_unlock(&zone->lock);
1154 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1155 zone_statistics(preferred_zone, zone);
1156 local_irq_restore(flags);
1159 VM_BUG_ON(bad_range(zone, page));
1160 if (prep_new_page(page, order, gfp_flags))
1165 local_irq_restore(flags);
1170 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1171 #define ALLOC_WMARK_MIN WMARK_MIN
1172 #define ALLOC_WMARK_LOW WMARK_LOW
1173 #define ALLOC_WMARK_HIGH WMARK_HIGH
1174 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1176 /* Mask to get the watermark bits */
1177 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1179 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1180 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1181 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1183 #ifdef CONFIG_FAIL_PAGE_ALLOC
1185 static struct fail_page_alloc_attr {
1186 struct fault_attr attr;
1188 u32 ignore_gfp_highmem;
1189 u32 ignore_gfp_wait;
1192 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1194 struct dentry *ignore_gfp_highmem_file;
1195 struct dentry *ignore_gfp_wait_file;
1196 struct dentry *min_order_file;
1198 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1200 } fail_page_alloc = {
1201 .attr = FAULT_ATTR_INITIALIZER,
1202 .ignore_gfp_wait = 1,
1203 .ignore_gfp_highmem = 1,
1207 static int __init setup_fail_page_alloc(char *str)
1209 return setup_fault_attr(&fail_page_alloc.attr, str);
1211 __setup("fail_page_alloc=", setup_fail_page_alloc);
1213 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1215 if (order < fail_page_alloc.min_order)
1217 if (gfp_mask & __GFP_NOFAIL)
1219 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1221 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1224 return should_fail(&fail_page_alloc.attr, 1 << order);
1227 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1229 static int __init fail_page_alloc_debugfs(void)
1231 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1235 err = init_fault_attr_dentries(&fail_page_alloc.attr,
1239 dir = fail_page_alloc.attr.dentries.dir;
1241 fail_page_alloc.ignore_gfp_wait_file =
1242 debugfs_create_bool("ignore-gfp-wait", mode, dir,
1243 &fail_page_alloc.ignore_gfp_wait);
1245 fail_page_alloc.ignore_gfp_highmem_file =
1246 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1247 &fail_page_alloc.ignore_gfp_highmem);
1248 fail_page_alloc.min_order_file =
1249 debugfs_create_u32("min-order", mode, dir,
1250 &fail_page_alloc.min_order);
1252 if (!fail_page_alloc.ignore_gfp_wait_file ||
1253 !fail_page_alloc.ignore_gfp_highmem_file ||
1254 !fail_page_alloc.min_order_file) {
1256 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
1257 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1258 debugfs_remove(fail_page_alloc.min_order_file);
1259 cleanup_fault_attr_dentries(&fail_page_alloc.attr);
1265 late_initcall(fail_page_alloc_debugfs);
1267 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1269 #else /* CONFIG_FAIL_PAGE_ALLOC */
1271 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1276 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1279 * Return 1 if free pages are above 'mark'. This takes into account the order
1280 * of the allocation.
1282 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1283 int classzone_idx, int alloc_flags)
1285 /* free_pages my go negative - that's OK */
1287 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
1290 if (alloc_flags & ALLOC_HIGH)
1292 if (alloc_flags & ALLOC_HARDER)
1295 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1297 for (o = 0; o < order; o++) {
1298 /* At the next order, this order's pages become unavailable */
1299 free_pages -= z->free_area[o].nr_free << o;
1301 /* Require fewer higher order pages to be free */
1304 if (free_pages <= min)
1312 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1313 * skip over zones that are not allowed by the cpuset, or that have
1314 * been recently (in last second) found to be nearly full. See further
1315 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1316 * that have to skip over a lot of full or unallowed zones.
1318 * If the zonelist cache is present in the passed in zonelist, then
1319 * returns a pointer to the allowed node mask (either the current
1320 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1322 * If the zonelist cache is not available for this zonelist, does
1323 * nothing and returns NULL.
1325 * If the fullzones BITMAP in the zonelist cache is stale (more than
1326 * a second since last zap'd) then we zap it out (clear its bits.)
1328 * We hold off even calling zlc_setup, until after we've checked the
1329 * first zone in the zonelist, on the theory that most allocations will
1330 * be satisfied from that first zone, so best to examine that zone as
1331 * quickly as we can.
1333 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1335 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1336 nodemask_t *allowednodes; /* zonelist_cache approximation */
1338 zlc = zonelist->zlcache_ptr;
1342 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1343 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1344 zlc->last_full_zap = jiffies;
1347 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1348 &cpuset_current_mems_allowed :
1349 &node_states[N_HIGH_MEMORY];
1350 return allowednodes;
1354 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1355 * if it is worth looking at further for free memory:
1356 * 1) Check that the zone isn't thought to be full (doesn't have its
1357 * bit set in the zonelist_cache fullzones BITMAP).
1358 * 2) Check that the zones node (obtained from the zonelist_cache
1359 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1360 * Return true (non-zero) if zone is worth looking at further, or
1361 * else return false (zero) if it is not.
1363 * This check -ignores- the distinction between various watermarks,
1364 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1365 * found to be full for any variation of these watermarks, it will
1366 * be considered full for up to one second by all requests, unless
1367 * we are so low on memory on all allowed nodes that we are forced
1368 * into the second scan of the zonelist.
1370 * In the second scan we ignore this zonelist cache and exactly
1371 * apply the watermarks to all zones, even it is slower to do so.
1372 * We are low on memory in the second scan, and should leave no stone
1373 * unturned looking for a free page.
1375 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1376 nodemask_t *allowednodes)
1378 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1379 int i; /* index of *z in zonelist zones */
1380 int n; /* node that zone *z is on */
1382 zlc = zonelist->zlcache_ptr;
1386 i = z - zonelist->_zonerefs;
1389 /* This zone is worth trying if it is allowed but not full */
1390 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1394 * Given 'z' scanning a zonelist, set the corresponding bit in
1395 * zlc->fullzones, so that subsequent attempts to allocate a page
1396 * from that zone don't waste time re-examining it.
1398 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1400 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1401 int i; /* index of *z in zonelist zones */
1403 zlc = zonelist->zlcache_ptr;
1407 i = z - zonelist->_zonerefs;
1409 set_bit(i, zlc->fullzones);
1412 #else /* CONFIG_NUMA */
1414 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1419 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1420 nodemask_t *allowednodes)
1425 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1428 #endif /* CONFIG_NUMA */
1431 * get_page_from_freelist goes through the zonelist trying to allocate
1434 static struct page *
1435 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1436 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1437 struct zone *preferred_zone, int migratetype)
1440 struct page *page = NULL;
1443 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1444 int zlc_active = 0; /* set if using zonelist_cache */
1445 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1447 classzone_idx = zone_idx(preferred_zone);
1450 * Scan zonelist, looking for a zone with enough free.
1451 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1453 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1454 high_zoneidx, nodemask) {
1455 if (NUMA_BUILD && zlc_active &&
1456 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1458 if ((alloc_flags & ALLOC_CPUSET) &&
1459 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1462 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1463 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1465 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1466 if (!zone_watermark_ok(zone, order, mark,
1467 classzone_idx, alloc_flags)) {
1468 if (!zone_reclaim_mode ||
1469 !zone_reclaim(zone, gfp_mask, order))
1470 goto this_zone_full;
1474 page = buffered_rmqueue(preferred_zone, zone, order,
1475 gfp_mask, migratetype);
1480 zlc_mark_zone_full(zonelist, z);
1482 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1484 * we do zlc_setup after the first zone is tried but only
1485 * if there are multiple nodes make it worthwhile
1487 allowednodes = zlc_setup(zonelist, alloc_flags);
1493 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1494 /* Disable zlc cache for second zonelist scan */
1502 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
1503 unsigned long pages_reclaimed)
1505 /* Do not loop if specifically requested */
1506 if (gfp_mask & __GFP_NORETRY)
1510 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1511 * means __GFP_NOFAIL, but that may not be true in other
1514 if (order <= PAGE_ALLOC_COSTLY_ORDER)
1518 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1519 * specified, then we retry until we no longer reclaim any pages
1520 * (above), or we've reclaimed an order of pages at least as
1521 * large as the allocation's order. In both cases, if the
1522 * allocation still fails, we stop retrying.
1524 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
1528 * Don't let big-order allocations loop unless the caller
1529 * explicitly requests that.
1531 if (gfp_mask & __GFP_NOFAIL)
1537 static inline struct page *
1538 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
1539 struct zonelist *zonelist, enum zone_type high_zoneidx,
1540 nodemask_t *nodemask, struct zone *preferred_zone,
1545 /* Acquire the OOM killer lock for the zones in zonelist */
1546 if (!try_set_zone_oom(zonelist, gfp_mask)) {
1547 schedule_timeout_uninterruptible(1);
1552 * Go through the zonelist yet one more time, keep very high watermark
1553 * here, this is only to catch a parallel oom killing, we must fail if
1554 * we're still under heavy pressure.
1556 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
1557 order, zonelist, high_zoneidx,
1558 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1559 preferred_zone, migratetype);
1563 /* The OOM killer will not help higher order allocs */
1564 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))
1567 /* Exhausted what can be done so it's blamo time */
1568 out_of_memory(zonelist, gfp_mask, order);
1571 clear_zonelist_oom(zonelist, gfp_mask);
1575 /* The really slow allocator path where we enter direct reclaim */
1576 static inline struct page *
1577 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
1578 struct zonelist *zonelist, enum zone_type high_zoneidx,
1579 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1580 int migratetype, unsigned long *did_some_progress)
1582 struct page *page = NULL;
1583 struct reclaim_state reclaim_state;
1584 struct task_struct *p = current;
1588 /* We now go into synchronous reclaim */
1589 cpuset_memory_pressure_bump();
1592 * The task's cpuset might have expanded its set of allowable nodes
1594 p->flags |= PF_MEMALLOC;
1595 lockdep_set_current_reclaim_state(gfp_mask);
1596 reclaim_state.reclaimed_slab = 0;
1597 p->reclaim_state = &reclaim_state;
1599 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
1601 p->reclaim_state = NULL;
1602 lockdep_clear_current_reclaim_state();
1603 p->flags &= ~PF_MEMALLOC;
1610 if (likely(*did_some_progress))
1611 page = get_page_from_freelist(gfp_mask, nodemask, order,
1612 zonelist, high_zoneidx,
1613 alloc_flags, preferred_zone,
1619 * This is called in the allocator slow-path if the allocation request is of
1620 * sufficient urgency to ignore watermarks and take other desperate measures
1622 static inline struct page *
1623 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
1624 struct zonelist *zonelist, enum zone_type high_zoneidx,
1625 nodemask_t *nodemask, struct zone *preferred_zone,
1631 page = get_page_from_freelist(gfp_mask, nodemask, order,
1632 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1633 preferred_zone, migratetype);
1635 if (!page && gfp_mask & __GFP_NOFAIL)
1636 congestion_wait(WRITE, HZ/50);
1637 } while (!page && (gfp_mask & __GFP_NOFAIL));
1643 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
1644 enum zone_type high_zoneidx)
1649 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
1650 wakeup_kswapd(zone, order);
1654 gfp_to_alloc_flags(gfp_t gfp_mask)
1656 struct task_struct *p = current;
1657 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
1658 const gfp_t wait = gfp_mask & __GFP_WAIT;
1660 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1661 BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1664 * The caller may dip into page reserves a bit more if the caller
1665 * cannot run direct reclaim, or if the caller has realtime scheduling
1666 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1667 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1669 alloc_flags |= (gfp_mask & __GFP_HIGH);
1672 alloc_flags |= ALLOC_HARDER;
1674 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1675 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1677 alloc_flags &= ~ALLOC_CPUSET;
1678 } else if (unlikely(rt_task(p)))
1679 alloc_flags |= ALLOC_HARDER;
1681 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
1682 if (!in_interrupt() &&
1683 ((p->flags & PF_MEMALLOC) ||
1684 unlikely(test_thread_flag(TIF_MEMDIE))))
1685 alloc_flags |= ALLOC_NO_WATERMARKS;
1691 static inline struct page *
1692 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
1693 struct zonelist *zonelist, enum zone_type high_zoneidx,
1694 nodemask_t *nodemask, struct zone *preferred_zone,
1697 const gfp_t wait = gfp_mask & __GFP_WAIT;
1698 struct page *page = NULL;
1700 unsigned long pages_reclaimed = 0;
1701 unsigned long did_some_progress;
1702 struct task_struct *p = current;
1705 * In the slowpath, we sanity check order to avoid ever trying to
1706 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
1707 * be using allocators in order of preference for an area that is
1710 if (WARN_ON_ONCE(order >= MAX_ORDER))
1714 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1715 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1716 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1717 * using a larger set of nodes after it has established that the
1718 * allowed per node queues are empty and that nodes are
1721 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
1724 wake_all_kswapd(order, zonelist, high_zoneidx);
1727 * OK, we're below the kswapd watermark and have kicked background
1728 * reclaim. Now things get more complex, so set up alloc_flags according
1729 * to how we want to proceed.
1731 alloc_flags = gfp_to_alloc_flags(gfp_mask);
1734 /* This is the last chance, in general, before the goto nopage. */
1735 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1736 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
1737 preferred_zone, migratetype);
1742 /* Allocate without watermarks if the context allows */
1743 if (alloc_flags & ALLOC_NO_WATERMARKS) {
1744 page = __alloc_pages_high_priority(gfp_mask, order,
1745 zonelist, high_zoneidx, nodemask,
1746 preferred_zone, migratetype);
1751 /* Atomic allocations - we can't balance anything */
1755 /* Avoid recursion of direct reclaim */
1756 if (p->flags & PF_MEMALLOC)
1759 /* Try direct reclaim and then allocating */
1760 page = __alloc_pages_direct_reclaim(gfp_mask, order,
1761 zonelist, high_zoneidx,
1763 alloc_flags, preferred_zone,
1764 migratetype, &did_some_progress);
1769 * If we failed to make any progress reclaiming, then we are
1770 * running out of options and have to consider going OOM
1772 if (!did_some_progress) {
1773 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1774 if (oom_killer_disabled)
1776 page = __alloc_pages_may_oom(gfp_mask, order,
1777 zonelist, high_zoneidx,
1778 nodemask, preferred_zone,
1784 * The OOM killer does not trigger for high-order
1785 * ~__GFP_NOFAIL allocations so if no progress is being
1786 * made, there are no other options and retrying is
1789 if (order > PAGE_ALLOC_COSTLY_ORDER &&
1790 !(gfp_mask & __GFP_NOFAIL))
1797 /* Check if we should retry the allocation */
1798 pages_reclaimed += did_some_progress;
1799 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
1800 /* Wait for some write requests to complete then retry */
1801 congestion_wait(WRITE, HZ/50);
1806 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
1807 printk(KERN_WARNING "%s: page allocation failure."
1808 " order:%d, mode:0x%x\n",
1809 p->comm, order, gfp_mask);
1819 * This is the 'heart' of the zoned buddy allocator.
1822 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
1823 struct zonelist *zonelist, nodemask_t *nodemask)
1825 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1826 struct zone *preferred_zone;
1828 int migratetype = allocflags_to_migratetype(gfp_mask);
1830 lockdep_trace_alloc(gfp_mask);
1832 might_sleep_if(gfp_mask & __GFP_WAIT);
1834 if (should_fail_alloc_page(gfp_mask, order))
1838 * Check the zones suitable for the gfp_mask contain at least one
1839 * valid zone. It's possible to have an empty zonelist as a result
1840 * of GFP_THISNODE and a memoryless node
1842 if (unlikely(!zonelist->_zonerefs->zone))
1845 /* The preferred zone is used for statistics later */
1846 first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
1847 if (!preferred_zone)
1850 /* First allocation attempt */
1851 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1852 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1853 preferred_zone, migratetype);
1854 if (unlikely(!page))
1855 page = __alloc_pages_slowpath(gfp_mask, order,
1856 zonelist, high_zoneidx, nodemask,
1857 preferred_zone, migratetype);
1861 EXPORT_SYMBOL(__alloc_pages_nodemask);
1864 * Common helper functions.
1866 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
1869 page = alloc_pages(gfp_mask, order);
1872 return (unsigned long) page_address(page);
1875 EXPORT_SYMBOL(__get_free_pages);
1877 unsigned long get_zeroed_page(gfp_t gfp_mask)
1882 * get_zeroed_page() returns a 32-bit address, which cannot represent
1885 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
1887 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1889 return (unsigned long) page_address(page);
1893 EXPORT_SYMBOL(get_zeroed_page);
1895 void __pagevec_free(struct pagevec *pvec)
1897 int i = pagevec_count(pvec);
1900 free_hot_cold_page(pvec->pages[i], pvec->cold);
1903 void __free_pages(struct page *page, unsigned int order)
1905 if (put_page_testzero(page)) {
1907 free_hot_page(page);
1909 __free_pages_ok(page, order);
1913 EXPORT_SYMBOL(__free_pages);
1915 void free_pages(unsigned long addr, unsigned int order)
1918 VM_BUG_ON(!virt_addr_valid((void *)addr));
1919 __free_pages(virt_to_page((void *)addr), order);
1923 EXPORT_SYMBOL(free_pages);
1926 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
1927 * @size: the number of bytes to allocate
1928 * @gfp_mask: GFP flags for the allocation
1930 * This function is similar to alloc_pages(), except that it allocates the
1931 * minimum number of pages to satisfy the request. alloc_pages() can only
1932 * allocate memory in power-of-two pages.
1934 * This function is also limited by MAX_ORDER.
1936 * Memory allocated by this function must be released by free_pages_exact().
1938 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
1940 unsigned int order = get_order(size);
1943 addr = __get_free_pages(gfp_mask, order);
1945 unsigned long alloc_end = addr + (PAGE_SIZE << order);
1946 unsigned long used = addr + PAGE_ALIGN(size);
1948 split_page(virt_to_page(addr), order);
1949 while (used < alloc_end) {
1955 return (void *)addr;
1957 EXPORT_SYMBOL(alloc_pages_exact);
1960 * free_pages_exact - release memory allocated via alloc_pages_exact()
1961 * @virt: the value returned by alloc_pages_exact.
1962 * @size: size of allocation, same value as passed to alloc_pages_exact().
1964 * Release the memory allocated by a previous call to alloc_pages_exact.
1966 void free_pages_exact(void *virt, size_t size)
1968 unsigned long addr = (unsigned long)virt;
1969 unsigned long end = addr + PAGE_ALIGN(size);
1971 while (addr < end) {
1976 EXPORT_SYMBOL(free_pages_exact);
1978 static unsigned int nr_free_zone_pages(int offset)
1983 /* Just pick one node, since fallback list is circular */
1984 unsigned int sum = 0;
1986 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
1988 for_each_zone_zonelist(zone, z, zonelist, offset) {
1989 unsigned long size = zone->present_pages;
1990 unsigned long high = high_wmark_pages(zone);
1999 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2001 unsigned int nr_free_buffer_pages(void)
2003 return nr_free_zone_pages(gfp_zone(GFP_USER));
2005 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2008 * Amount of free RAM allocatable within all zones
2010 unsigned int nr_free_pagecache_pages(void)
2012 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2015 static inline void show_node(struct zone *zone)
2018 printk("Node %d ", zone_to_nid(zone));
2021 void si_meminfo(struct sysinfo *val)
2023 val->totalram = totalram_pages;
2025 val->freeram = global_page_state(NR_FREE_PAGES);
2026 val->bufferram = nr_blockdev_pages();
2027 val->totalhigh = totalhigh_pages;
2028 val->freehigh = nr_free_highpages();
2029 val->mem_unit = PAGE_SIZE;
2032 EXPORT_SYMBOL(si_meminfo);
2035 void si_meminfo_node(struct sysinfo *val, int nid)
2037 pg_data_t *pgdat = NODE_DATA(nid);
2039 val->totalram = pgdat->node_present_pages;
2040 val->freeram = node_page_state(nid, NR_FREE_PAGES);
2041 #ifdef CONFIG_HIGHMEM
2042 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2043 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2049 val->mem_unit = PAGE_SIZE;
2053 #define K(x) ((x) << (PAGE_SHIFT-10))
2056 * Show free area list (used inside shift_scroll-lock stuff)
2057 * We also calculate the percentage fragmentation. We do this by counting the
2058 * memory on each free list with the exception of the first item on the list.
2060 void show_free_areas(void)
2065 for_each_populated_zone(zone) {
2067 printk("%s per-cpu:\n", zone->name);
2069 for_each_online_cpu(cpu) {
2070 struct per_cpu_pageset *pageset;
2072 pageset = zone_pcp(zone, cpu);
2074 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2075 cpu, pageset->pcp.high,
2076 pageset->pcp.batch, pageset->pcp.count);
2080 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
2081 " inactive_file:%lu"
2083 " dirty:%lu writeback:%lu unstable:%lu\n"
2084 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
2085 global_page_state(NR_ACTIVE_ANON),
2086 global_page_state(NR_ACTIVE_FILE),
2087 global_page_state(NR_INACTIVE_ANON),
2088 global_page_state(NR_INACTIVE_FILE),
2089 global_page_state(NR_UNEVICTABLE),
2090 global_page_state(NR_FILE_DIRTY),
2091 global_page_state(NR_WRITEBACK),
2092 global_page_state(NR_UNSTABLE_NFS),
2093 global_page_state(NR_FREE_PAGES),
2094 global_page_state(NR_SLAB_RECLAIMABLE) +
2095 global_page_state(NR_SLAB_UNRECLAIMABLE),
2096 global_page_state(NR_FILE_MAPPED),
2097 global_page_state(NR_PAGETABLE),
2098 global_page_state(NR_BOUNCE));
2100 for_each_populated_zone(zone) {
2109 " active_anon:%lukB"
2110 " inactive_anon:%lukB"
2111 " active_file:%lukB"
2112 " inactive_file:%lukB"
2113 " unevictable:%lukB"
2115 " pages_scanned:%lu"
2116 " all_unreclaimable? %s"
2119 K(zone_page_state(zone, NR_FREE_PAGES)),
2120 K(min_wmark_pages(zone)),
2121 K(low_wmark_pages(zone)),
2122 K(high_wmark_pages(zone)),
2123 K(zone_page_state(zone, NR_ACTIVE_ANON)),
2124 K(zone_page_state(zone, NR_INACTIVE_ANON)),
2125 K(zone_page_state(zone, NR_ACTIVE_FILE)),
2126 K(zone_page_state(zone, NR_INACTIVE_FILE)),
2127 K(zone_page_state(zone, NR_UNEVICTABLE)),
2128 K(zone->present_pages),
2129 zone->pages_scanned,
2130 (zone_is_all_unreclaimable(zone) ? "yes" : "no")
2132 printk("lowmem_reserve[]:");
2133 for (i = 0; i < MAX_NR_ZONES; i++)
2134 printk(" %lu", zone->lowmem_reserve[i]);
2138 for_each_populated_zone(zone) {
2139 unsigned long nr[MAX_ORDER], flags, order, total = 0;
2142 printk("%s: ", zone->name);
2144 spin_lock_irqsave(&zone->lock, flags);
2145 for (order = 0; order < MAX_ORDER; order++) {
2146 nr[order] = zone->free_area[order].nr_free;
2147 total += nr[order] << order;
2149 spin_unlock_irqrestore(&zone->lock, flags);
2150 for (order = 0; order < MAX_ORDER; order++)
2151 printk("%lu*%lukB ", nr[order], K(1UL) << order);
2152 printk("= %lukB\n", K(total));
2155 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
2157 show_swap_cache_info();
2160 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
2162 zoneref->zone = zone;
2163 zoneref->zone_idx = zone_idx(zone);
2167 * Builds allocation fallback zone lists.
2169 * Add all populated zones of a node to the zonelist.
2171 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
2172 int nr_zones, enum zone_type zone_type)
2176 BUG_ON(zone_type >= MAX_NR_ZONES);
2181 zone = pgdat->node_zones + zone_type;
2182 if (populated_zone(zone)) {
2183 zoneref_set_zone(zone,
2184 &zonelist->_zonerefs[nr_zones++]);
2185 check_highest_zone(zone_type);
2188 } while (zone_type);
2195 * 0 = automatic detection of better ordering.
2196 * 1 = order by ([node] distance, -zonetype)
2197 * 2 = order by (-zonetype, [node] distance)
2199 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2200 * the same zonelist. So only NUMA can configure this param.
2202 #define ZONELIST_ORDER_DEFAULT 0
2203 #define ZONELIST_ORDER_NODE 1
2204 #define ZONELIST_ORDER_ZONE 2
2206 /* zonelist order in the kernel.
2207 * set_zonelist_order() will set this to NODE or ZONE.
2209 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
2210 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
2214 /* The value user specified ....changed by config */
2215 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2216 /* string for sysctl */
2217 #define NUMA_ZONELIST_ORDER_LEN 16
2218 char numa_zonelist_order[16] = "default";
2221 * interface for configure zonelist ordering.
2222 * command line option "numa_zonelist_order"
2223 * = "[dD]efault - default, automatic configuration.
2224 * = "[nN]ode - order by node locality, then by zone within node
2225 * = "[zZ]one - order by zone, then by locality within zone
2228 static int __parse_numa_zonelist_order(char *s)
2230 if (*s == 'd' || *s == 'D') {
2231 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2232 } else if (*s == 'n' || *s == 'N') {
2233 user_zonelist_order = ZONELIST_ORDER_NODE;
2234 } else if (*s == 'z' || *s == 'Z') {
2235 user_zonelist_order = ZONELIST_ORDER_ZONE;
2238 "Ignoring invalid numa_zonelist_order value: "
2245 static __init int setup_numa_zonelist_order(char *s)
2248 return __parse_numa_zonelist_order(s);
2251 early_param("numa_zonelist_order", setup_numa_zonelist_order);
2254 * sysctl handler for numa_zonelist_order
2256 int numa_zonelist_order_handler(ctl_table *table, int write,
2257 struct file *file, void __user *buffer, size_t *length,
2260 char saved_string[NUMA_ZONELIST_ORDER_LEN];
2264 strncpy(saved_string, (char*)table->data,
2265 NUMA_ZONELIST_ORDER_LEN);
2266 ret = proc_dostring(table, write, file, buffer, length, ppos);
2270 int oldval = user_zonelist_order;
2271 if (__parse_numa_zonelist_order((char*)table->data)) {
2273 * bogus value. restore saved string
2275 strncpy((char*)table->data, saved_string,
2276 NUMA_ZONELIST_ORDER_LEN);
2277 user_zonelist_order = oldval;
2278 } else if (oldval != user_zonelist_order)
2279 build_all_zonelists();
2285 #define MAX_NODE_LOAD (nr_online_nodes)
2286 static int node_load[MAX_NUMNODES];
2289 * find_next_best_node - find the next node that should appear in a given node's fallback list
2290 * @node: node whose fallback list we're appending
2291 * @used_node_mask: nodemask_t of already used nodes
2293 * We use a number of factors to determine which is the next node that should
2294 * appear on a given node's fallback list. The node should not have appeared
2295 * already in @node's fallback list, and it should be the next closest node
2296 * according to the distance array (which contains arbitrary distance values
2297 * from each node to each node in the system), and should also prefer nodes
2298 * with no CPUs, since presumably they'll have very little allocation pressure
2299 * on them otherwise.
2300 * It returns -1 if no node is found.
2302 static int find_next_best_node(int node, nodemask_t *used_node_mask)
2305 int min_val = INT_MAX;
2307 const struct cpumask *tmp = cpumask_of_node(0);
2309 /* Use the local node if we haven't already */
2310 if (!node_isset(node, *used_node_mask)) {
2311 node_set(node, *used_node_mask);
2315 for_each_node_state(n, N_HIGH_MEMORY) {
2317 /* Don't want a node to appear more than once */
2318 if (node_isset(n, *used_node_mask))
2321 /* Use the distance array to find the distance */
2322 val = node_distance(node, n);
2324 /* Penalize nodes under us ("prefer the next node") */
2327 /* Give preference to headless and unused nodes */
2328 tmp = cpumask_of_node(n);
2329 if (!cpumask_empty(tmp))
2330 val += PENALTY_FOR_NODE_WITH_CPUS;
2332 /* Slight preference for less loaded node */
2333 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2334 val += node_load[n];
2336 if (val < min_val) {
2343 node_set(best_node, *used_node_mask);
2350 * Build zonelists ordered by node and zones within node.
2351 * This results in maximum locality--normal zone overflows into local
2352 * DMA zone, if any--but risks exhausting DMA zone.
2354 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2357 struct zonelist *zonelist;
2359 zonelist = &pgdat->node_zonelists[0];
2360 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2362 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2364 zonelist->_zonerefs[j].zone = NULL;
2365 zonelist->_zonerefs[j].zone_idx = 0;
2369 * Build gfp_thisnode zonelists
2371 static void build_thisnode_zonelists(pg_data_t *pgdat)
2374 struct zonelist *zonelist;
2376 zonelist = &pgdat->node_zonelists[1];
2377 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2378 zonelist->_zonerefs[j].zone = NULL;
2379 zonelist->_zonerefs[j].zone_idx = 0;
2383 * Build zonelists ordered by zone and nodes within zones.
2384 * This results in conserving DMA zone[s] until all Normal memory is
2385 * exhausted, but results in overflowing to remote node while memory
2386 * may still exist in local DMA zone.
2388 static int node_order[MAX_NUMNODES];
2390 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2393 int zone_type; /* needs to be signed */
2395 struct zonelist *zonelist;
2397 zonelist = &pgdat->node_zonelists[0];
2399 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
2400 for (j = 0; j < nr_nodes; j++) {
2401 node = node_order[j];
2402 z = &NODE_DATA(node)->node_zones[zone_type];
2403 if (populated_zone(z)) {
2405 &zonelist->_zonerefs[pos++]);
2406 check_highest_zone(zone_type);
2410 zonelist->_zonerefs[pos].zone = NULL;
2411 zonelist->_zonerefs[pos].zone_idx = 0;
2414 static int default_zonelist_order(void)
2417 unsigned long low_kmem_size,total_size;
2421 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2422 * If they are really small and used heavily, the system can fall
2423 * into OOM very easily.
2424 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2426 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2429 for_each_online_node(nid) {
2430 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2431 z = &NODE_DATA(nid)->node_zones[zone_type];
2432 if (populated_zone(z)) {
2433 if (zone_type < ZONE_NORMAL)
2434 low_kmem_size += z->present_pages;
2435 total_size += z->present_pages;
2439 if (!low_kmem_size || /* there are no DMA area. */
2440 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
2441 return ZONELIST_ORDER_NODE;
2443 * look into each node's config.
2444 * If there is a node whose DMA/DMA32 memory is very big area on
2445 * local memory, NODE_ORDER may be suitable.
2447 average_size = total_size /
2448 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2449 for_each_online_node(nid) {
2452 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2453 z = &NODE_DATA(nid)->node_zones[zone_type];
2454 if (populated_zone(z)) {
2455 if (zone_type < ZONE_NORMAL)
2456 low_kmem_size += z->present_pages;
2457 total_size += z->present_pages;
2460 if (low_kmem_size &&
2461 total_size > average_size && /* ignore small node */
2462 low_kmem_size > total_size * 70/100)
2463 return ZONELIST_ORDER_NODE;
2465 return ZONELIST_ORDER_ZONE;
2468 static void set_zonelist_order(void)
2470 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
2471 current_zonelist_order = default_zonelist_order();
2473 current_zonelist_order = user_zonelist_order;
2476 static void build_zonelists(pg_data_t *pgdat)
2480 nodemask_t used_mask;
2481 int local_node, prev_node;
2482 struct zonelist *zonelist;
2483 int order = current_zonelist_order;
2485 /* initialize zonelists */
2486 for (i = 0; i < MAX_ZONELISTS; i++) {
2487 zonelist = pgdat->node_zonelists + i;
2488 zonelist->_zonerefs[0].zone = NULL;
2489 zonelist->_zonerefs[0].zone_idx = 0;
2492 /* NUMA-aware ordering of nodes */
2493 local_node = pgdat->node_id;
2494 load = nr_online_nodes;
2495 prev_node = local_node;
2496 nodes_clear(used_mask);
2498 memset(node_load, 0, sizeof(node_load));
2499 memset(node_order, 0, sizeof(node_order));
2502 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2503 int distance = node_distance(local_node, node);
2506 * If another node is sufficiently far away then it is better
2507 * to reclaim pages in a zone before going off node.
2509 if (distance > RECLAIM_DISTANCE)
2510 zone_reclaim_mode = 1;
2513 * We don't want to pressure a particular node.
2514 * So adding penalty to the first node in same
2515 * distance group to make it round-robin.
2517 if (distance != node_distance(local_node, prev_node))
2518 node_load[node] = load;
2522 if (order == ZONELIST_ORDER_NODE)
2523 build_zonelists_in_node_order(pgdat, node);
2525 node_order[j++] = node; /* remember order */
2528 if (order == ZONELIST_ORDER_ZONE) {
2529 /* calculate node order -- i.e., DMA last! */
2530 build_zonelists_in_zone_order(pgdat, j);
2533 build_thisnode_zonelists(pgdat);
2536 /* Construct the zonelist performance cache - see further mmzone.h */
2537 static void build_zonelist_cache(pg_data_t *pgdat)
2539 struct zonelist *zonelist;
2540 struct zonelist_cache *zlc;
2543 zonelist = &pgdat->node_zonelists[0];
2544 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
2545 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2546 for (z = zonelist->_zonerefs; z->zone; z++)
2547 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2551 #else /* CONFIG_NUMA */
2553 static void set_zonelist_order(void)
2555 current_zonelist_order = ZONELIST_ORDER_ZONE;
2558 static void build_zonelists(pg_data_t *pgdat)
2560 int node, local_node;
2562 struct zonelist *zonelist;
2564 local_node = pgdat->node_id;
2566 zonelist = &pgdat->node_zonelists[0];
2567 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2570 * Now we build the zonelist so that it contains the zones
2571 * of all the other nodes.
2572 * We don't want to pressure a particular node, so when
2573 * building the zones for node N, we make sure that the
2574 * zones coming right after the local ones are those from
2575 * node N+1 (modulo N)
2577 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
2578 if (!node_online(node))
2580 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2583 for (node = 0; node < local_node; node++) {
2584 if (!node_online(node))
2586 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2590 zonelist->_zonerefs[j].zone = NULL;
2591 zonelist->_zonerefs[j].zone_idx = 0;
2594 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2595 static void build_zonelist_cache(pg_data_t *pgdat)
2597 pgdat->node_zonelists[0].zlcache_ptr = NULL;
2600 #endif /* CONFIG_NUMA */
2602 /* return values int ....just for stop_machine() */
2603 static int __build_all_zonelists(void *dummy)
2607 for_each_online_node(nid) {
2608 pg_data_t *pgdat = NODE_DATA(nid);
2610 build_zonelists(pgdat);
2611 build_zonelist_cache(pgdat);
2616 void build_all_zonelists(void)
2618 set_zonelist_order();
2620 if (system_state == SYSTEM_BOOTING) {
2621 __build_all_zonelists(NULL);
2622 mminit_verify_zonelist();
2623 cpuset_init_current_mems_allowed();
2625 /* we have to stop all cpus to guarantee there is no user
2627 stop_machine(__build_all_zonelists, NULL, NULL);
2628 /* cpuset refresh routine should be here */
2630 vm_total_pages = nr_free_pagecache_pages();
2632 * Disable grouping by mobility if the number of pages in the
2633 * system is too low to allow the mechanism to work. It would be
2634 * more accurate, but expensive to check per-zone. This check is
2635 * made on memory-hotadd so a system can start with mobility
2636 * disabled and enable it later
2638 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2639 page_group_by_mobility_disabled = 1;
2641 page_group_by_mobility_disabled = 0;
2643 printk("Built %i zonelists in %s order, mobility grouping %s. "
2644 "Total pages: %ld\n",
2646 zonelist_order_name[current_zonelist_order],
2647 page_group_by_mobility_disabled ? "off" : "on",
2650 printk("Policy zone: %s\n", zone_names[policy_zone]);
2655 * Helper functions to size the waitqueue hash table.
2656 * Essentially these want to choose hash table sizes sufficiently
2657 * large so that collisions trying to wait on pages are rare.
2658 * But in fact, the number of active page waitqueues on typical
2659 * systems is ridiculously low, less than 200. So this is even
2660 * conservative, even though it seems large.
2662 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2663 * waitqueues, i.e. the size of the waitq table given the number of pages.
2665 #define PAGES_PER_WAITQUEUE 256
2667 #ifndef CONFIG_MEMORY_HOTPLUG
2668 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2670 unsigned long size = 1;
2672 pages /= PAGES_PER_WAITQUEUE;
2674 while (size < pages)
2678 * Once we have dozens or even hundreds of threads sleeping
2679 * on IO we've got bigger problems than wait queue collision.
2680 * Limit the size of the wait table to a reasonable size.
2682 size = min(size, 4096UL);
2684 return max(size, 4UL);
2688 * A zone's size might be changed by hot-add, so it is not possible to determine
2689 * a suitable size for its wait_table. So we use the maximum size now.
2691 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2693 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2694 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2695 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2697 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2698 * or more by the traditional way. (See above). It equals:
2700 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2701 * ia64(16K page size) : = ( 8G + 4M)byte.
2702 * powerpc (64K page size) : = (32G +16M)byte.
2704 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2711 * This is an integer logarithm so that shifts can be used later
2712 * to extract the more random high bits from the multiplicative
2713 * hash function before the remainder is taken.
2715 static inline unsigned long wait_table_bits(unsigned long size)
2720 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2723 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2724 * of blocks reserved is based on min_wmark_pages(zone). The memory within
2725 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
2726 * higher will lead to a bigger reserve which will get freed as contiguous
2727 * blocks as reclaim kicks in
2729 static void setup_zone_migrate_reserve(struct zone *zone)
2731 unsigned long start_pfn, pfn, end_pfn;
2733 unsigned long reserve, block_migratetype;
2735 /* Get the start pfn, end pfn and the number of blocks to reserve */
2736 start_pfn = zone->zone_start_pfn;
2737 end_pfn = start_pfn + zone->spanned_pages;
2738 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2741 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2742 if (!pfn_valid(pfn))
2744 page = pfn_to_page(pfn);
2746 /* Watch out for overlapping nodes */
2747 if (page_to_nid(page) != zone_to_nid(zone))
2750 /* Blocks with reserved pages will never free, skip them. */
2751 if (PageReserved(page))
2754 block_migratetype = get_pageblock_migratetype(page);
2756 /* If this block is reserved, account for it */
2757 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
2762 /* Suitable for reserving if this block is movable */
2763 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
2764 set_pageblock_migratetype(page, MIGRATE_RESERVE);
2765 move_freepages_block(zone, page, MIGRATE_RESERVE);
2771 * If the reserve is met and this is a previous reserved block,
2774 if (block_migratetype == MIGRATE_RESERVE) {
2775 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2776 move_freepages_block(zone, page, MIGRATE_MOVABLE);
2782 * Initially all pages are reserved - free ones are freed
2783 * up by free_all_bootmem() once the early boot process is
2784 * done. Non-atomic initialization, single-pass.
2786 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
2787 unsigned long start_pfn, enum memmap_context context)
2790 unsigned long end_pfn = start_pfn + size;
2794 if (highest_memmap_pfn < end_pfn - 1)
2795 highest_memmap_pfn = end_pfn - 1;
2797 z = &NODE_DATA(nid)->node_zones[zone];
2798 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
2800 * There can be holes in boot-time mem_map[]s
2801 * handed to this function. They do not
2802 * exist on hotplugged memory.
2804 if (context == MEMMAP_EARLY) {
2805 if (!early_pfn_valid(pfn))
2807 if (!early_pfn_in_nid(pfn, nid))
2810 page = pfn_to_page(pfn);
2811 set_page_links(page, zone, nid, pfn);
2812 mminit_verify_page_links(page, zone, nid, pfn);
2813 init_page_count(page);
2814 reset_page_mapcount(page);
2815 SetPageReserved(page);
2817 * Mark the block movable so that blocks are reserved for
2818 * movable at startup. This will force kernel allocations
2819 * to reserve their blocks rather than leaking throughout
2820 * the address space during boot when many long-lived
2821 * kernel allocations are made. Later some blocks near
2822 * the start are marked MIGRATE_RESERVE by
2823 * setup_zone_migrate_reserve()
2825 * bitmap is created for zone's valid pfn range. but memmap
2826 * can be created for invalid pages (for alignment)
2827 * check here not to call set_pageblock_migratetype() against
2830 if ((z->zone_start_pfn <= pfn)
2831 && (pfn < z->zone_start_pfn + z->spanned_pages)
2832 && !(pfn & (pageblock_nr_pages - 1)))
2833 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2835 INIT_LIST_HEAD(&page->lru);
2836 #ifdef WANT_PAGE_VIRTUAL
2837 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2838 if (!is_highmem_idx(zone))
2839 set_page_address(page, __va(pfn << PAGE_SHIFT));
2844 static void __meminit zone_init_free_lists(struct zone *zone)
2847 for_each_migratetype_order(order, t) {
2848 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
2849 zone->free_area[order].nr_free = 0;
2853 #ifndef __HAVE_ARCH_MEMMAP_INIT
2854 #define memmap_init(size, nid, zone, start_pfn) \
2855 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2858 static int zone_batchsize(struct zone *zone)
2864 * The per-cpu-pages pools are set to around 1000th of the
2865 * size of the zone. But no more than 1/2 of a meg.
2867 * OK, so we don't know how big the cache is. So guess.
2869 batch = zone->present_pages / 1024;
2870 if (batch * PAGE_SIZE > 512 * 1024)
2871 batch = (512 * 1024) / PAGE_SIZE;
2872 batch /= 4; /* We effectively *= 4 below */
2877 * Clamp the batch to a 2^n - 1 value. Having a power
2878 * of 2 value was found to be more likely to have
2879 * suboptimal cache aliasing properties in some cases.
2881 * For example if 2 tasks are alternately allocating
2882 * batches of pages, one task can end up with a lot
2883 * of pages of one half of the possible page colors
2884 * and the other with pages of the other colors.
2886 batch = rounddown_pow_of_two(batch + batch/2) - 1;
2891 /* The deferral and batching of frees should be suppressed under NOMMU
2894 * The problem is that NOMMU needs to be able to allocate large chunks
2895 * of contiguous memory as there's no hardware page translation to
2896 * assemble apparent contiguous memory from discontiguous pages.
2898 * Queueing large contiguous runs of pages for batching, however,
2899 * causes the pages to actually be freed in smaller chunks. As there
2900 * can be a significant delay between the individual batches being
2901 * recycled, this leads to the once large chunks of space being
2902 * fragmented and becoming unavailable for high-order allocations.
2908 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2910 struct per_cpu_pages *pcp;
2912 memset(p, 0, sizeof(*p));
2916 pcp->high = 6 * batch;
2917 pcp->batch = max(1UL, 1 * batch);
2918 INIT_LIST_HEAD(&pcp->list);
2922 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2923 * to the value high for the pageset p.
2926 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
2929 struct per_cpu_pages *pcp;
2933 pcp->batch = max(1UL, high/4);
2934 if ((high/4) > (PAGE_SHIFT * 8))
2935 pcp->batch = PAGE_SHIFT * 8;
2941 * Boot pageset table. One per cpu which is going to be used for all
2942 * zones and all nodes. The parameters will be set in such a way
2943 * that an item put on a list will immediately be handed over to
2944 * the buddy list. This is safe since pageset manipulation is done
2945 * with interrupts disabled.
2947 * Some NUMA counter updates may also be caught by the boot pagesets.
2949 * The boot_pagesets must be kept even after bootup is complete for
2950 * unused processors and/or zones. They do play a role for bootstrapping
2951 * hotplugged processors.
2953 * zoneinfo_show() and maybe other functions do
2954 * not check if the processor is online before following the pageset pointer.
2955 * Other parts of the kernel may not check if the zone is available.
2957 static struct per_cpu_pageset boot_pageset[NR_CPUS];
2960 * Dynamically allocate memory for the
2961 * per cpu pageset array in struct zone.
2963 static int __cpuinit process_zones(int cpu)
2965 struct zone *zone, *dzone;
2966 int node = cpu_to_node(cpu);
2968 node_set_state(node, N_CPU); /* this node has a cpu */
2970 for_each_populated_zone(zone) {
2971 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2973 if (!zone_pcp(zone, cpu))
2976 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2978 if (percpu_pagelist_fraction)
2979 setup_pagelist_highmark(zone_pcp(zone, cpu),
2980 (zone->present_pages / percpu_pagelist_fraction));
2985 for_each_zone(dzone) {
2986 if (!populated_zone(dzone))
2990 kfree(zone_pcp(dzone, cpu));
2991 zone_pcp(dzone, cpu) = NULL;
2996 static inline void free_zone_pagesets(int cpu)
3000 for_each_zone(zone) {
3001 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
3003 /* Free per_cpu_pageset if it is slab allocated */
3004 if (pset != &boot_pageset[cpu])
3006 zone_pcp(zone, cpu) = NULL;
3010 static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3011 unsigned long action,
3014 int cpu = (long)hcpu;
3015 int ret = NOTIFY_OK;
3018 case CPU_UP_PREPARE:
3019 case CPU_UP_PREPARE_FROZEN:
3020 if (process_zones(cpu))
3023 case CPU_UP_CANCELED:
3024 case CPU_UP_CANCELED_FROZEN:
3026 case CPU_DEAD_FROZEN:
3027 free_zone_pagesets(cpu);
3035 static struct notifier_block __cpuinitdata pageset_notifier =
3036 { &pageset_cpuup_callback, NULL, 0 };
3038 void __init setup_per_cpu_pageset(void)
3042 /* Initialize per_cpu_pageset for cpu 0.
3043 * A cpuup callback will do this for every cpu
3044 * as it comes online
3046 err = process_zones(smp_processor_id());
3048 register_cpu_notifier(&pageset_notifier);
3053 static noinline __init_refok
3054 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3057 struct pglist_data *pgdat = zone->zone_pgdat;
3061 * The per-page waitqueue mechanism uses hashed waitqueues
3064 zone->wait_table_hash_nr_entries =
3065 wait_table_hash_nr_entries(zone_size_pages);
3066 zone->wait_table_bits =
3067 wait_table_bits(zone->wait_table_hash_nr_entries);
3068 alloc_size = zone->wait_table_hash_nr_entries
3069 * sizeof(wait_queue_head_t);
3071 if (!slab_is_available()) {
3072 zone->wait_table = (wait_queue_head_t *)
3073 alloc_bootmem_node(pgdat, alloc_size);
3076 * This case means that a zone whose size was 0 gets new memory
3077 * via memory hot-add.
3078 * But it may be the case that a new node was hot-added. In
3079 * this case vmalloc() will not be able to use this new node's
3080 * memory - this wait_table must be initialized to use this new
3081 * node itself as well.
3082 * To use this new node's memory, further consideration will be
3085 zone->wait_table = vmalloc(alloc_size);
3087 if (!zone->wait_table)
3090 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3091 init_waitqueue_head(zone->wait_table + i);
3096 static __meminit void zone_pcp_init(struct zone *zone)
3099 unsigned long batch = zone_batchsize(zone);
3101 for (cpu = 0; cpu < NR_CPUS; cpu++) {
3103 /* Early boot. Slab allocator not functional yet */
3104 zone_pcp(zone, cpu) = &boot_pageset[cpu];
3105 setup_pageset(&boot_pageset[cpu],0);
3107 setup_pageset(zone_pcp(zone,cpu), batch);
3110 if (zone->present_pages)
3111 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
3112 zone->name, zone->present_pages, batch);
3115 __meminit int init_currently_empty_zone(struct zone *zone,
3116 unsigned long zone_start_pfn,
3118 enum memmap_context context)
3120 struct pglist_data *pgdat = zone->zone_pgdat;
3122 ret = zone_wait_table_init(zone, size);
3125 pgdat->nr_zones = zone_idx(zone) + 1;
3127 zone->zone_start_pfn = zone_start_pfn;
3129 mminit_dprintk(MMINIT_TRACE, "memmap_init",
3130 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3132 (unsigned long)zone_idx(zone),
3133 zone_start_pfn, (zone_start_pfn + size));
3135 zone_init_free_lists(zone);
3140 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3142 * Basic iterator support. Return the first range of PFNs for a node
3143 * Note: nid == MAX_NUMNODES returns first region regardless of node
3145 static int __meminit first_active_region_index_in_nid(int nid)
3149 for (i = 0; i < nr_nodemap_entries; i++)
3150 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3157 * Basic iterator support. Return the next active range of PFNs for a node
3158 * Note: nid == MAX_NUMNODES returns next region regardless of node
3160 static int __meminit next_active_region_index_in_nid(int index, int nid)
3162 for (index = index + 1; index < nr_nodemap_entries; index++)
3163 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3169 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3171 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3172 * Architectures may implement their own version but if add_active_range()
3173 * was used and there are no special requirements, this is a convenient
3176 int __meminit __early_pfn_to_nid(unsigned long pfn)
3180 for (i = 0; i < nr_nodemap_entries; i++) {
3181 unsigned long start_pfn = early_node_map[i].start_pfn;
3182 unsigned long end_pfn = early_node_map[i].end_pfn;
3184 if (start_pfn <= pfn && pfn < end_pfn)
3185 return early_node_map[i].nid;
3187 /* This is a memory hole */
3190 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3192 int __meminit early_pfn_to_nid(unsigned long pfn)
3196 nid = __early_pfn_to_nid(pfn);
3199 /* just returns 0 */
3203 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3204 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
3208 nid = __early_pfn_to_nid(pfn);
3209 if (nid >= 0 && nid != node)
3215 /* Basic iterator support to walk early_node_map[] */
3216 #define for_each_active_range_index_in_nid(i, nid) \
3217 for (i = first_active_region_index_in_nid(nid); i != -1; \
3218 i = next_active_region_index_in_nid(i, nid))
3221 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3222 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3223 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3225 * If an architecture guarantees that all ranges registered with
3226 * add_active_ranges() contain no holes and may be freed, this
3227 * this function may be used instead of calling free_bootmem() manually.
3229 void __init free_bootmem_with_active_regions(int nid,
3230 unsigned long max_low_pfn)
3234 for_each_active_range_index_in_nid(i, nid) {
3235 unsigned long size_pages = 0;
3236 unsigned long end_pfn = early_node_map[i].end_pfn;
3238 if (early_node_map[i].start_pfn >= max_low_pfn)
3241 if (end_pfn > max_low_pfn)
3242 end_pfn = max_low_pfn;
3244 size_pages = end_pfn - early_node_map[i].start_pfn;
3245 free_bootmem_node(NODE_DATA(early_node_map[i].nid),
3246 PFN_PHYS(early_node_map[i].start_pfn),
3247 size_pages << PAGE_SHIFT);
3251 void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
3256 for_each_active_range_index_in_nid(i, nid) {
3257 ret = work_fn(early_node_map[i].start_pfn,
3258 early_node_map[i].end_pfn, data);
3264 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3265 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3267 * If an architecture guarantees that all ranges registered with
3268 * add_active_ranges() contain no holes and may be freed, this
3269 * function may be used instead of calling memory_present() manually.
3271 void __init sparse_memory_present_with_active_regions(int nid)
3275 for_each_active_range_index_in_nid(i, nid)
3276 memory_present(early_node_map[i].nid,
3277 early_node_map[i].start_pfn,
3278 early_node_map[i].end_pfn);
3282 * get_pfn_range_for_nid - Return the start and end page frames for a node
3283 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3284 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3285 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3287 * It returns the start and end page frame of a node based on information
3288 * provided by an arch calling add_active_range(). If called for a node
3289 * with no available memory, a warning is printed and the start and end
3292 void __meminit get_pfn_range_for_nid(unsigned int nid,
3293 unsigned long *start_pfn, unsigned long *end_pfn)
3299 for_each_active_range_index_in_nid(i, nid) {
3300 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
3301 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
3304 if (*start_pfn == -1UL)
3309 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3310 * assumption is made that zones within a node are ordered in monotonic
3311 * increasing memory addresses so that the "highest" populated zone is used
3313 static void __init find_usable_zone_for_movable(void)
3316 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
3317 if (zone_index == ZONE_MOVABLE)
3320 if (arch_zone_highest_possible_pfn[zone_index] >
3321 arch_zone_lowest_possible_pfn[zone_index])
3325 VM_BUG_ON(zone_index == -1);
3326 movable_zone = zone_index;
3330 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3331 * because it is sized independant of architecture. Unlike the other zones,
3332 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3333 * in each node depending on the size of each node and how evenly kernelcore
3334 * is distributed. This helper function adjusts the zone ranges
3335 * provided by the architecture for a given node by using the end of the
3336 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3337 * zones within a node are in order of monotonic increases memory addresses
3339 static void __meminit adjust_zone_range_for_zone_movable(int nid,
3340 unsigned long zone_type,
3341 unsigned long node_start_pfn,
3342 unsigned long node_end_pfn,
3343 unsigned long *zone_start_pfn,
3344 unsigned long *zone_end_pfn)
3346 /* Only adjust if ZONE_MOVABLE is on this node */
3347 if (zone_movable_pfn[nid]) {
3348 /* Size ZONE_MOVABLE */
3349 if (zone_type == ZONE_MOVABLE) {
3350 *zone_start_pfn = zone_movable_pfn[nid];
3351 *zone_end_pfn = min(node_end_pfn,
3352 arch_zone_highest_possible_pfn[movable_zone]);
3354 /* Adjust for ZONE_MOVABLE starting within this range */
3355 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
3356 *zone_end_pfn > zone_movable_pfn[nid]) {
3357 *zone_end_pfn = zone_movable_pfn[nid];
3359 /* Check if this whole range is within ZONE_MOVABLE */
3360 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
3361 *zone_start_pfn = *zone_end_pfn;
3366 * Return the number of pages a zone spans in a node, including holes
3367 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3369 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3370 unsigned long zone_type,
3371 unsigned long *ignored)
3373 unsigned long node_start_pfn, node_end_pfn;
3374 unsigned long zone_start_pfn, zone_end_pfn;
3376 /* Get the start and end of the node and zone */
3377 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3378 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
3379 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
3380 adjust_zone_range_for_zone_movable(nid, zone_type,
3381 node_start_pfn, node_end_pfn,
3382 &zone_start_pfn, &zone_end_pfn);
3384 /* Check that this node has pages within the zone's required range */
3385 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
3388 /* Move the zone boundaries inside the node if necessary */
3389 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
3390 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
3392 /* Return the spanned pages */
3393 return zone_end_pfn - zone_start_pfn;
3397 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3398 * then all holes in the requested range will be accounted for.
3400 static unsigned long __meminit __absent_pages_in_range(int nid,
3401 unsigned long range_start_pfn,
3402 unsigned long range_end_pfn)
3405 unsigned long prev_end_pfn = 0, hole_pages = 0;
3406 unsigned long start_pfn;
3408 /* Find the end_pfn of the first active range of pfns in the node */
3409 i = first_active_region_index_in_nid(nid);
3413 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3415 /* Account for ranges before physical memory on this node */
3416 if (early_node_map[i].start_pfn > range_start_pfn)
3417 hole_pages = prev_end_pfn - range_start_pfn;
3419 /* Find all holes for the zone within the node */
3420 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
3422 /* No need to continue if prev_end_pfn is outside the zone */
3423 if (prev_end_pfn >= range_end_pfn)
3426 /* Make sure the end of the zone is not within the hole */
3427 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3428 prev_end_pfn = max(prev_end_pfn, range_start_pfn);
3430 /* Update the hole size cound and move on */
3431 if (start_pfn > range_start_pfn) {
3432 BUG_ON(prev_end_pfn > start_pfn);
3433 hole_pages += start_pfn - prev_end_pfn;
3435 prev_end_pfn = early_node_map[i].end_pfn;
3438 /* Account for ranges past physical memory on this node */
3439 if (range_end_pfn > prev_end_pfn)
3440 hole_pages += range_end_pfn -
3441 max(range_start_pfn, prev_end_pfn);
3447 * absent_pages_in_range - Return number of page frames in holes within a range
3448 * @start_pfn: The start PFN to start searching for holes
3449 * @end_pfn: The end PFN to stop searching for holes
3451 * It returns the number of pages frames in memory holes within a range.
3453 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
3454 unsigned long end_pfn)
3456 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
3459 /* Return the number of page frames in holes in a zone on a node */
3460 static unsigned long __meminit zone_absent_pages_in_node(int nid,
3461 unsigned long zone_type,
3462 unsigned long *ignored)
3464 unsigned long node_start_pfn, node_end_pfn;
3465 unsigned long zone_start_pfn, zone_end_pfn;
3467 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3468 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
3470 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
3473 adjust_zone_range_for_zone_movable(nid, zone_type,
3474 node_start_pfn, node_end_pfn,
3475 &zone_start_pfn, &zone_end_pfn);
3476 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3480 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3481 unsigned long zone_type,
3482 unsigned long *zones_size)
3484 return zones_size[zone_type];
3487 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3488 unsigned long zone_type,
3489 unsigned long *zholes_size)
3494 return zholes_size[zone_type];
3499 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3500 unsigned long *zones_size, unsigned long *zholes_size)
3502 unsigned long realtotalpages, totalpages = 0;
3505 for (i = 0; i < MAX_NR_ZONES; i++)
3506 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
3508 pgdat->node_spanned_pages = totalpages;
3510 realtotalpages = totalpages;
3511 for (i = 0; i < MAX_NR_ZONES; i++)
3513 zone_absent_pages_in_node(pgdat->node_id, i,
3515 pgdat->node_present_pages = realtotalpages;
3516 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
3520 #ifndef CONFIG_SPARSEMEM
3522 * Calculate the size of the zone->blockflags rounded to an unsigned long
3523 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3524 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3525 * round what is now in bits to nearest long in bits, then return it in
3528 static unsigned long __init usemap_size(unsigned long zonesize)
3530 unsigned long usemapsize;
3532 usemapsize = roundup(zonesize, pageblock_nr_pages);
3533 usemapsize = usemapsize >> pageblock_order;
3534 usemapsize *= NR_PAGEBLOCK_BITS;
3535 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
3537 return usemapsize / 8;
3540 static void __init setup_usemap(struct pglist_data *pgdat,
3541 struct zone *zone, unsigned long zonesize)
3543 unsigned long usemapsize = usemap_size(zonesize);
3544 zone->pageblock_flags = NULL;
3546 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
3549 static void inline setup_usemap(struct pglist_data *pgdat,
3550 struct zone *zone, unsigned long zonesize) {}
3551 #endif /* CONFIG_SPARSEMEM */
3553 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3555 /* Return a sensible default order for the pageblock size. */
3556 static inline int pageblock_default_order(void)
3558 if (HPAGE_SHIFT > PAGE_SHIFT)
3559 return HUGETLB_PAGE_ORDER;
3564 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3565 static inline void __init set_pageblock_order(unsigned int order)
3567 /* Check that pageblock_nr_pages has not already been setup */
3568 if (pageblock_order)
3572 * Assume the largest contiguous order of interest is a huge page.
3573 * This value may be variable depending on boot parameters on IA64
3575 pageblock_order = order;
3577 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3580 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3581 * and pageblock_default_order() are unused as pageblock_order is set
3582 * at compile-time. See include/linux/pageblock-flags.h for the values of
3583 * pageblock_order based on the kernel config
3585 static inline int pageblock_default_order(unsigned int order)
3589 #define set_pageblock_order(x) do {} while (0)
3591 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3594 * Set up the zone data structures:
3595 * - mark all pages reserved
3596 * - mark all memory queues empty
3597 * - clear the memory bitmaps
3599 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
3600 unsigned long *zones_size, unsigned long *zholes_size)
3603 int nid = pgdat->node_id;
3604 unsigned long zone_start_pfn = pgdat->node_start_pfn;
3607 pgdat_resize_init(pgdat);
3608 pgdat->nr_zones = 0;
3609 init_waitqueue_head(&pgdat->kswapd_wait);
3610 pgdat->kswapd_max_order = 0;
3611 pgdat_page_cgroup_init(pgdat);
3613 for (j = 0; j < MAX_NR_ZONES; j++) {
3614 struct zone *zone = pgdat->node_zones + j;
3615 unsigned long size, realsize, memmap_pages;
3618 size = zone_spanned_pages_in_node(nid, j, zones_size);
3619 realsize = size - zone_absent_pages_in_node(nid, j,
3623 * Adjust realsize so that it accounts for how much memory
3624 * is used by this zone for memmap. This affects the watermark
3625 * and per-cpu initialisations
3628 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3629 if (realsize >= memmap_pages) {
3630 realsize -= memmap_pages;
3633 " %s zone: %lu pages used for memmap\n",
3634 zone_names[j], memmap_pages);
3637 " %s zone: %lu pages exceeds realsize %lu\n",
3638 zone_names[j], memmap_pages, realsize);
3640 /* Account for reserved pages */
3641 if (j == 0 && realsize > dma_reserve) {
3642 realsize -= dma_reserve;
3643 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
3644 zone_names[0], dma_reserve);
3647 if (!is_highmem_idx(j))
3648 nr_kernel_pages += realsize;
3649 nr_all_pages += realsize;
3651 zone->spanned_pages = size;
3652 zone->present_pages = realsize;
3655 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3657 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3659 zone->name = zone_names[j];
3660 spin_lock_init(&zone->lock);
3661 spin_lock_init(&zone->lru_lock);
3662 zone_seqlock_init(zone);
3663 zone->zone_pgdat = pgdat;
3665 zone->prev_priority = DEF_PRIORITY;
3667 zone_pcp_init(zone);
3669 INIT_LIST_HEAD(&zone->lru[l].list);
3670 zone->lru[l].nr_saved_scan = 0;
3672 zone->reclaim_stat.recent_rotated[0] = 0;
3673 zone->reclaim_stat.recent_rotated[1] = 0;
3674 zone->reclaim_stat.recent_scanned[0] = 0;
3675 zone->reclaim_stat.recent_scanned[1] = 0;
3676 zap_zone_vm_stats(zone);
3681 set_pageblock_order(pageblock_default_order());
3682 setup_usemap(pgdat, zone, size);
3683 ret = init_currently_empty_zone(zone, zone_start_pfn,
3684 size, MEMMAP_EARLY);
3686 memmap_init(size, nid, j, zone_start_pfn);
3687 zone_start_pfn += size;
3691 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
3693 /* Skip empty nodes */
3694 if (!pgdat->node_spanned_pages)
3697 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3698 /* ia64 gets its own node_mem_map, before this, without bootmem */
3699 if (!pgdat->node_mem_map) {
3700 unsigned long size, start, end;
3704 * The zone's endpoints aren't required to be MAX_ORDER
3705 * aligned but the node_mem_map endpoints must be in order
3706 * for the buddy allocator to function correctly.
3708 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
3709 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
3710 end = ALIGN(end, MAX_ORDER_NR_PAGES);
3711 size = (end - start) * sizeof(struct page);
3712 map = alloc_remap(pgdat->node_id, size);
3714 map = alloc_bootmem_node(pgdat, size);
3715 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
3717 #ifndef CONFIG_NEED_MULTIPLE_NODES
3719 * With no DISCONTIG, the global mem_map is just set as node 0's
3721 if (pgdat == NODE_DATA(0)) {
3722 mem_map = NODE_DATA(0)->node_mem_map;
3723 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3724 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3725 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3726 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3729 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3732 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
3733 unsigned long node_start_pfn, unsigned long *zholes_size)
3735 pg_data_t *pgdat = NODE_DATA(nid);
3737 pgdat->node_id = nid;
3738 pgdat->node_start_pfn = node_start_pfn;
3739 calculate_node_totalpages(pgdat, zones_size, zholes_size);
3741 alloc_node_mem_map(pgdat);
3742 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3743 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3744 nid, (unsigned long)pgdat,
3745 (unsigned long)pgdat->node_mem_map);
3748 free_area_init_core(pgdat, zones_size, zholes_size);
3751 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3753 #if MAX_NUMNODES > 1
3755 * Figure out the number of possible node ids.
3757 static void __init setup_nr_node_ids(void)
3760 unsigned int highest = 0;
3762 for_each_node_mask(node, node_possible_map)
3764 nr_node_ids = highest + 1;
3767 static inline void setup_nr_node_ids(void)
3773 * add_active_range - Register a range of PFNs backed by physical memory
3774 * @nid: The node ID the range resides on
3775 * @start_pfn: The start PFN of the available physical memory
3776 * @end_pfn: The end PFN of the available physical memory
3778 * These ranges are stored in an early_node_map[] and later used by
3779 * free_area_init_nodes() to calculate zone sizes and holes. If the
3780 * range spans a memory hole, it is up to the architecture to ensure
3781 * the memory is not freed by the bootmem allocator. If possible
3782 * the range being registered will be merged with existing ranges.
3784 void __init add_active_range(unsigned int nid, unsigned long start_pfn,
3785 unsigned long end_pfn)
3789 mminit_dprintk(MMINIT_TRACE, "memory_register",
3790 "Entering add_active_range(%d, %#lx, %#lx) "
3791 "%d entries of %d used\n",
3792 nid, start_pfn, end_pfn,
3793 nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3795 mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
3797 /* Merge with existing active regions if possible */
3798 for (i = 0; i < nr_nodemap_entries; i++) {
3799 if (early_node_map[i].nid != nid)
3802 /* Skip if an existing region covers this new one */
3803 if (start_pfn >= early_node_map[i].start_pfn &&
3804 end_pfn <= early_node_map[i].end_pfn)
3807 /* Merge forward if suitable */
3808 if (start_pfn <= early_node_map[i].end_pfn &&
3809 end_pfn > early_node_map[i].end_pfn) {
3810 early_node_map[i].end_pfn = end_pfn;
3814 /* Merge backward if suitable */
3815 if (start_pfn < early_node_map[i].end_pfn &&
3816 end_pfn >= early_node_map[i].start_pfn) {
3817 early_node_map[i].start_pfn = start_pfn;
3822 /* Check that early_node_map is large enough */
3823 if (i >= MAX_ACTIVE_REGIONS) {
3824 printk(KERN_CRIT "More than %d memory regions, truncating\n",
3825 MAX_ACTIVE_REGIONS);
3829 early_node_map[i].nid = nid;
3830 early_node_map[i].start_pfn = start_pfn;
3831 early_node_map[i].end_pfn = end_pfn;
3832 nr_nodemap_entries = i + 1;
3836 * remove_active_range - Shrink an existing registered range of PFNs
3837 * @nid: The node id the range is on that should be shrunk
3838 * @start_pfn: The new PFN of the range
3839 * @end_pfn: The new PFN of the range
3841 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3842 * The map is kept near the end physical page range that has already been
3843 * registered. This function allows an arch to shrink an existing registered
3846 void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
3847 unsigned long end_pfn)
3852 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
3853 nid, start_pfn, end_pfn);
3855 /* Find the old active region end and shrink */
3856 for_each_active_range_index_in_nid(i, nid) {
3857 if (early_node_map[i].start_pfn >= start_pfn &&
3858 early_node_map[i].end_pfn <= end_pfn) {
3860 early_node_map[i].start_pfn = 0;
3861 early_node_map[i].end_pfn = 0;
3865 if (early_node_map[i].start_pfn < start_pfn &&
3866 early_node_map[i].end_pfn > start_pfn) {
3867 unsigned long temp_end_pfn = early_node_map[i].end_pfn;
3868 early_node_map[i].end_pfn = start_pfn;
3869 if (temp_end_pfn > end_pfn)
3870 add_active_range(nid, end_pfn, temp_end_pfn);
3873 if (early_node_map[i].start_pfn >= start_pfn &&
3874 early_node_map[i].end_pfn > end_pfn &&
3875 early_node_map[i].start_pfn < end_pfn) {
3876 early_node_map[i].start_pfn = end_pfn;
3884 /* remove the blank ones */
3885 for (i = nr_nodemap_entries - 1; i > 0; i--) {
3886 if (early_node_map[i].nid != nid)
3888 if (early_node_map[i].end_pfn)
3890 /* we found it, get rid of it */
3891 for (j = i; j < nr_nodemap_entries - 1; j++)
3892 memcpy(&early_node_map[j], &early_node_map[j+1],
3893 sizeof(early_node_map[j]));
3894 j = nr_nodemap_entries - 1;
3895 memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
3896 nr_nodemap_entries--;
3901 * remove_all_active_ranges - Remove all currently registered regions
3903 * During discovery, it may be found that a table like SRAT is invalid
3904 * and an alternative discovery method must be used. This function removes
3905 * all currently registered regions.
3907 void __init remove_all_active_ranges(void)
3909 memset(early_node_map, 0, sizeof(early_node_map));
3910 nr_nodemap_entries = 0;
3913 /* Compare two active node_active_regions */
3914 static int __init cmp_node_active_region(const void *a, const void *b)
3916 struct node_active_region *arange = (struct node_active_region *)a;
3917 struct node_active_region *brange = (struct node_active_region *)b;
3919 /* Done this way to avoid overflows */
3920 if (arange->start_pfn > brange->start_pfn)
3922 if (arange->start_pfn < brange->start_pfn)
3928 /* sort the node_map by start_pfn */
3929 static void __init sort_node_map(void)
3931 sort(early_node_map, (size_t)nr_nodemap_entries,
3932 sizeof(struct node_active_region),
3933 cmp_node_active_region, NULL);
3936 /* Find the lowest pfn for a node */
3937 static unsigned long __init find_min_pfn_for_node(int nid)
3940 unsigned long min_pfn = ULONG_MAX;
3942 /* Assuming a sorted map, the first range found has the starting pfn */
3943 for_each_active_range_index_in_nid(i, nid)
3944 min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3946 if (min_pfn == ULONG_MAX) {
3948 "Could not find start_pfn for node %d\n", nid);
3956 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3958 * It returns the minimum PFN based on information provided via
3959 * add_active_range().
3961 unsigned long __init find_min_pfn_with_active_regions(void)
3963 return find_min_pfn_for_node(MAX_NUMNODES);
3967 * early_calculate_totalpages()
3968 * Sum pages in active regions for movable zone.
3969 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3971 static unsigned long __init early_calculate_totalpages(void)
3974 unsigned long totalpages = 0;
3976 for (i = 0; i < nr_nodemap_entries; i++) {
3977 unsigned long pages = early_node_map[i].end_pfn -
3978 early_node_map[i].start_pfn;
3979 totalpages += pages;
3981 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
3987 * Find the PFN the Movable zone begins in each node. Kernel memory
3988 * is spread evenly between nodes as long as the nodes have enough
3989 * memory. When they don't, some nodes will have more kernelcore than
3992 static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
3995 unsigned long usable_startpfn;
3996 unsigned long kernelcore_node, kernelcore_remaining;
3997 unsigned long totalpages = early_calculate_totalpages();
3998 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
4001 * If movablecore was specified, calculate what size of
4002 * kernelcore that corresponds so that memory usable for
4003 * any allocation type is evenly spread. If both kernelcore
4004 * and movablecore are specified, then the value of kernelcore
4005 * will be used for required_kernelcore if it's greater than
4006 * what movablecore would have allowed.
4008 if (required_movablecore) {
4009 unsigned long corepages;
4012 * Round-up so that ZONE_MOVABLE is at least as large as what
4013 * was requested by the user
4015 required_movablecore =
4016 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4017 corepages = totalpages - required_movablecore;
4019 required_kernelcore = max(required_kernelcore, corepages);
4022 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4023 if (!required_kernelcore)
4026 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4027 find_usable_zone_for_movable();
4028 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4031 /* Spread kernelcore memory as evenly as possible throughout nodes */
4032 kernelcore_node = required_kernelcore / usable_nodes;
4033 for_each_node_state(nid, N_HIGH_MEMORY) {
4035 * Recalculate kernelcore_node if the division per node
4036 * now exceeds what is necessary to satisfy the requested
4037 * amount of memory for the kernel
4039 if (required_kernelcore < kernelcore_node)
4040 kernelcore_node = required_kernelcore / usable_nodes;
4043 * As the map is walked, we track how much memory is usable
4044 * by the kernel using kernelcore_remaining. When it is
4045 * 0, the rest of the node is usable by ZONE_MOVABLE
4047 kernelcore_remaining = kernelcore_node;
4049 /* Go through each range of PFNs within this node */
4050 for_each_active_range_index_in_nid(i, nid) {
4051 unsigned long start_pfn, end_pfn;
4052 unsigned long size_pages;
4054 start_pfn = max(early_node_map[i].start_pfn,
4055 zone_movable_pfn[nid]);
4056 end_pfn = early_node_map[i].end_pfn;
4057 if (start_pfn >= end_pfn)
4060 /* Account for what is only usable for kernelcore */
4061 if (start_pfn < usable_startpfn) {
4062 unsigned long kernel_pages;
4063 kernel_pages = min(end_pfn, usable_startpfn)
4066 kernelcore_remaining -= min(kernel_pages,
4067 kernelcore_remaining);
4068 required_kernelcore -= min(kernel_pages,
4069 required_kernelcore);
4071 /* Continue if range is now fully accounted */
4072 if (end_pfn <= usable_startpfn) {
4075 * Push zone_movable_pfn to the end so
4076 * that if we have to rebalance
4077 * kernelcore across nodes, we will
4078 * not double account here
4080 zone_movable_pfn[nid] = end_pfn;
4083 start_pfn = usable_startpfn;
4087 * The usable PFN range for ZONE_MOVABLE is from
4088 * start_pfn->end_pfn. Calculate size_pages as the
4089 * number of pages used as kernelcore
4091 size_pages = end_pfn - start_pfn;
4092 if (size_pages > kernelcore_remaining)
4093 size_pages = kernelcore_remaining;
4094 zone_movable_pfn[nid] = start_pfn + size_pages;
4097 * Some kernelcore has been met, update counts and
4098 * break if the kernelcore for this node has been
4101 required_kernelcore -= min(required_kernelcore,
4103 kernelcore_remaining -= size_pages;
4104 if (!kernelcore_remaining)
4110 * If there is still required_kernelcore, we do another pass with one
4111 * less node in the count. This will push zone_movable_pfn[nid] further
4112 * along on the nodes that still have memory until kernelcore is
4116 if (usable_nodes && required_kernelcore > usable_nodes)
4119 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4120 for (nid = 0; nid < MAX_NUMNODES; nid++)
4121 zone_movable_pfn[nid] =
4122 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4125 /* Any regular memory on that node ? */
4126 static void check_for_regular_memory(pg_data_t *pgdat)
4128 #ifdef CONFIG_HIGHMEM
4129 enum zone_type zone_type;
4131 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
4132 struct zone *zone = &pgdat->node_zones[zone_type];
4133 if (zone->present_pages)
4134 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
4140 * free_area_init_nodes - Initialise all pg_data_t and zone data
4141 * @max_zone_pfn: an array of max PFNs for each zone
4143 * This will call free_area_init_node() for each active node in the system.
4144 * Using the page ranges provided by add_active_range(), the size of each
4145 * zone in each node and their holes is calculated. If the maximum PFN
4146 * between two adjacent zones match, it is assumed that the zone is empty.
4147 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4148 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4149 * starts where the previous one ended. For example, ZONE_DMA32 starts
4150 * at arch_max_dma_pfn.
4152 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
4157 /* Sort early_node_map as initialisation assumes it is sorted */
4160 /* Record where the zone boundaries are */
4161 memset(arch_zone_lowest_possible_pfn, 0,
4162 sizeof(arch_zone_lowest_possible_pfn));
4163 memset(arch_zone_highest_possible_pfn, 0,
4164 sizeof(arch_zone_highest_possible_pfn));
4165 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
4166 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
4167 for (i = 1; i < MAX_NR_ZONES; i++) {
4168 if (i == ZONE_MOVABLE)
4170 arch_zone_lowest_possible_pfn[i] =
4171 arch_zone_highest_possible_pfn[i-1];
4172 arch_zone_highest_possible_pfn[i] =
4173 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
4175 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
4176 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
4178 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4179 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
4180 find_zone_movable_pfns_for_nodes(zone_movable_pfn);
4182 /* Print out the zone ranges */
4183 printk("Zone PFN ranges:\n");
4184 for (i = 0; i < MAX_NR_ZONES; i++) {
4185 if (i == ZONE_MOVABLE)
4187 printk(" %-8s %0#10lx -> %0#10lx\n",
4189 arch_zone_lowest_possible_pfn[i],
4190 arch_zone_highest_possible_pfn[i]);
4193 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4194 printk("Movable zone start PFN for each node\n");
4195 for (i = 0; i < MAX_NUMNODES; i++) {
4196 if (zone_movable_pfn[i])
4197 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
4200 /* Print out the early_node_map[] */
4201 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
4202 for (i = 0; i < nr_nodemap_entries; i++)
4203 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4204 early_node_map[i].start_pfn,
4205 early_node_map[i].end_pfn);
4207 /* Initialise every node */
4208 mminit_verify_pageflags_layout();
4209 setup_nr_node_ids();
4210 for_each_online_node(nid) {
4211 pg_data_t *pgdat = NODE_DATA(nid);
4212 free_area_init_node(nid, NULL,
4213 find_min_pfn_for_node(nid), NULL);
4215 /* Any memory on that node */
4216 if (pgdat->node_present_pages)
4217 node_set_state(nid, N_HIGH_MEMORY);
4218 check_for_regular_memory(pgdat);
4222 static int __init cmdline_parse_core(char *p, unsigned long *core)
4224 unsigned long long coremem;
4228 coremem = memparse(p, &p);
4229 *core = coremem >> PAGE_SHIFT;
4231 /* Paranoid check that UL is enough for the coremem value */
4232 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
4238 * kernelcore=size sets the amount of memory for use for allocations that
4239 * cannot be reclaimed or migrated.
4241 static int __init cmdline_parse_kernelcore(char *p)
4243 return cmdline_parse_core(p, &required_kernelcore);
4247 * movablecore=size sets the amount of memory for use for allocations that
4248 * can be reclaimed or migrated.
4250 static int __init cmdline_parse_movablecore(char *p)
4252 return cmdline_parse_core(p, &required_movablecore);
4255 early_param("kernelcore", cmdline_parse_kernelcore);
4256 early_param("movablecore", cmdline_parse_movablecore);
4258 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4261 * set_dma_reserve - set the specified number of pages reserved in the first zone
4262 * @new_dma_reserve: The number of pages to mark reserved
4264 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4265 * In the DMA zone, a significant percentage may be consumed by kernel image
4266 * and other unfreeable allocations which can skew the watermarks badly. This
4267 * function may optionally be used to account for unfreeable pages in the
4268 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4269 * smaller per-cpu batchsize.
4271 void __init set_dma_reserve(unsigned long new_dma_reserve)
4273 dma_reserve = new_dma_reserve;
4276 #ifndef CONFIG_NEED_MULTIPLE_NODES
4277 struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
4278 EXPORT_SYMBOL(contig_page_data);
4281 void __init free_area_init(unsigned long *zones_size)
4283 free_area_init_node(0, zones_size,
4284 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
4287 static int page_alloc_cpu_notify(struct notifier_block *self,
4288 unsigned long action, void *hcpu)
4290 int cpu = (unsigned long)hcpu;
4292 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4296 * Spill the event counters of the dead processor
4297 * into the current processors event counters.
4298 * This artificially elevates the count of the current
4301 vm_events_fold_cpu(cpu);
4304 * Zero the differential counters of the dead processor
4305 * so that the vm statistics are consistent.
4307 * This is only okay since the processor is dead and cannot
4308 * race with what we are doing.
4310 refresh_cpu_vm_stats(cpu);
4315 void __init page_alloc_init(void)
4317 hotcpu_notifier(page_alloc_cpu_notify, 0);
4321 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4322 * or min_free_kbytes changes.
4324 static void calculate_totalreserve_pages(void)
4326 struct pglist_data *pgdat;
4327 unsigned long reserve_pages = 0;
4328 enum zone_type i, j;
4330 for_each_online_pgdat(pgdat) {
4331 for (i = 0; i < MAX_NR_ZONES; i++) {
4332 struct zone *zone = pgdat->node_zones + i;
4333 unsigned long max = 0;
4335 /* Find valid and maximum lowmem_reserve in the zone */
4336 for (j = i; j < MAX_NR_ZONES; j++) {
4337 if (zone->lowmem_reserve[j] > max)
4338 max = zone->lowmem_reserve[j];
4341 /* we treat the high watermark as reserved pages. */
4342 max += high_wmark_pages(zone);
4344 if (max > zone->present_pages)
4345 max = zone->present_pages;
4346 reserve_pages += max;
4349 totalreserve_pages = reserve_pages;
4353 * setup_per_zone_lowmem_reserve - called whenever
4354 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4355 * has a correct pages reserved value, so an adequate number of
4356 * pages are left in the zone after a successful __alloc_pages().
4358 static void setup_per_zone_lowmem_reserve(void)
4360 struct pglist_data *pgdat;
4361 enum zone_type j, idx;
4363 for_each_online_pgdat(pgdat) {
4364 for (j = 0; j < MAX_NR_ZONES; j++) {
4365 struct zone *zone = pgdat->node_zones + j;
4366 unsigned long present_pages = zone->present_pages;
4368 zone->lowmem_reserve[j] = 0;
4372 struct zone *lower_zone;
4376 if (sysctl_lowmem_reserve_ratio[idx] < 1)
4377 sysctl_lowmem_reserve_ratio[idx] = 1;
4379 lower_zone = pgdat->node_zones + idx;
4380 lower_zone->lowmem_reserve[j] = present_pages /
4381 sysctl_lowmem_reserve_ratio[idx];
4382 present_pages += lower_zone->present_pages;
4387 /* update totalreserve_pages */
4388 calculate_totalreserve_pages();
4392 * setup_per_zone_wmarks - called when min_free_kbytes changes
4393 * or when memory is hot-{added|removed}
4395 * Ensures that the watermark[min,low,high] values for each zone are set
4396 * correctly with respect to min_free_kbytes.
4398 void setup_per_zone_wmarks(void)
4400 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
4401 unsigned long lowmem_pages = 0;
4403 unsigned long flags;
4405 /* Calculate total number of !ZONE_HIGHMEM pages */
4406 for_each_zone(zone) {
4407 if (!is_highmem(zone))
4408 lowmem_pages += zone->present_pages;
4411 for_each_zone(zone) {
4414 spin_lock_irqsave(&zone->lock, flags);
4415 tmp = (u64)pages_min * zone->present_pages;
4416 do_div(tmp, lowmem_pages);
4417 if (is_highmem(zone)) {
4419 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4420 * need highmem pages, so cap pages_min to a small
4423 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4424 * deltas controls asynch page reclaim, and so should
4425 * not be capped for highmem.
4429 min_pages = zone->present_pages / 1024;
4430 if (min_pages < SWAP_CLUSTER_MAX)
4431 min_pages = SWAP_CLUSTER_MAX;
4432 if (min_pages > 128)
4434 zone->watermark[WMARK_MIN] = min_pages;
4437 * If it's a lowmem zone, reserve a number of pages
4438 * proportionate to the zone's size.
4440 zone->watermark[WMARK_MIN] = tmp;
4443 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
4444 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4445 setup_zone_migrate_reserve(zone);
4446 spin_unlock_irqrestore(&zone->lock, flags);
4449 /* update totalreserve_pages */
4450 calculate_totalreserve_pages();
4454 * The inactive anon list should be small enough that the VM never has to
4455 * do too much work, but large enough that each inactive page has a chance
4456 * to be referenced again before it is swapped out.
4458 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4459 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4460 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4461 * the anonymous pages are kept on the inactive list.
4464 * memory ratio inactive anon
4465 * -------------------------------------
4474 void calculate_zone_inactive_ratio(struct zone *zone)
4476 unsigned int gb, ratio;
4478 /* Zone size in gigabytes */
4479 gb = zone->present_pages >> (30 - PAGE_SHIFT);
4481 ratio = int_sqrt(10 * gb);
4485 zone->inactive_ratio = ratio;
4488 static void __init setup_per_zone_inactive_ratio(void)
4493 calculate_zone_inactive_ratio(zone);
4497 * Initialise min_free_kbytes.
4499 * For small machines we want it small (128k min). For large machines
4500 * we want it large (64MB max). But it is not linear, because network
4501 * bandwidth does not increase linearly with machine size. We use
4503 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4504 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4520 static int __init init_per_zone_wmark_min(void)
4522 unsigned long lowmem_kbytes;
4524 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
4526 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
4527 if (min_free_kbytes < 128)
4528 min_free_kbytes = 128;
4529 if (min_free_kbytes > 65536)
4530 min_free_kbytes = 65536;
4531 setup_per_zone_wmarks();
4532 setup_per_zone_lowmem_reserve();
4533 setup_per_zone_inactive_ratio();
4536 module_init(init_per_zone_wmark_min)
4539 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4540 * that we can call two helper functions whenever min_free_kbytes
4543 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
4544 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4546 proc_dointvec(table, write, file, buffer, length, ppos);
4548 setup_per_zone_wmarks();
4553 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4554 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4559 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4564 zone->min_unmapped_pages = (zone->present_pages *
4565 sysctl_min_unmapped_ratio) / 100;
4569 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4570 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4575 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4580 zone->min_slab_pages = (zone->present_pages *
4581 sysctl_min_slab_ratio) / 100;
4587 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4588 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4589 * whenever sysctl_lowmem_reserve_ratio changes.
4591 * The reserve ratio obviously has absolutely no relation with the
4592 * minimum watermarks. The lowmem reserve ratio can only make sense
4593 * if in function of the boot time zone sizes.
4595 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4596 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4598 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4599 setup_per_zone_lowmem_reserve();
4604 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4605 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4606 * can have before it gets flushed back to buddy allocator.
4609 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
4610 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4616 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4617 if (!write || (ret == -EINVAL))
4619 for_each_zone(zone) {
4620 for_each_online_cpu(cpu) {
4622 high = zone->present_pages / percpu_pagelist_fraction;
4623 setup_pagelist_highmark(zone_pcp(zone, cpu), high);
4629 int hashdist = HASHDIST_DEFAULT;
4632 static int __init set_hashdist(char *str)
4636 hashdist = simple_strtoul(str, &str, 0);
4639 __setup("hashdist=", set_hashdist);
4643 * allocate a large system hash table from bootmem
4644 * - it is assumed that the hash table must contain an exact power-of-2
4645 * quantity of entries
4646 * - limit is the number of hash buckets, not the total allocation size
4648 void *__init alloc_large_system_hash(const char *tablename,
4649 unsigned long bucketsize,
4650 unsigned long numentries,
4653 unsigned int *_hash_shift,
4654 unsigned int *_hash_mask,
4655 unsigned long limit)
4657 unsigned long long max = limit;
4658 unsigned long log2qty, size;
4661 /* allow the kernel cmdline to have a say */
4663 /* round applicable memory size up to nearest megabyte */
4664 numentries = nr_kernel_pages;
4665 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
4666 numentries >>= 20 - PAGE_SHIFT;
4667 numentries <<= 20 - PAGE_SHIFT;
4669 /* limit to 1 bucket per 2^scale bytes of low memory */
4670 if (scale > PAGE_SHIFT)
4671 numentries >>= (scale - PAGE_SHIFT);
4673 numentries <<= (PAGE_SHIFT - scale);
4675 /* Make sure we've got at least a 0-order allocation.. */
4676 if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4677 numentries = PAGE_SIZE / bucketsize;
4679 numentries = roundup_pow_of_two(numentries);
4681 /* limit allocation size to 1/16 total memory by default */
4683 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
4684 do_div(max, bucketsize);
4687 if (numentries > max)
4690 log2qty = ilog2(numentries);
4693 size = bucketsize << log2qty;
4694 if (flags & HASH_EARLY)
4695 table = alloc_bootmem_nopanic(size);
4697 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
4700 * If bucketsize is not a power-of-two, we may free
4701 * some pages at the end of hash table which
4702 * alloc_pages_exact() automatically does
4704 if (get_order(size) < MAX_ORDER)
4705 table = alloc_pages_exact(size, GFP_ATOMIC);
4707 } while (!table && size > PAGE_SIZE && --log2qty);
4710 panic("Failed to allocate %s hash table\n", tablename);
4712 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
4715 ilog2(size) - PAGE_SHIFT,
4719 *_hash_shift = log2qty;
4721 *_hash_mask = (1 << log2qty) - 1;
4724 * If hashdist is set, the table allocation is done with __vmalloc()
4725 * which invokes the kmemleak_alloc() callback. This function may also
4726 * be called before the slab and kmemleak are initialised when
4727 * kmemleak simply buffers the request to be executed later
4728 * (GFP_ATOMIC flag ignored in this case).
4731 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
4736 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4737 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
4740 #ifdef CONFIG_SPARSEMEM
4741 return __pfn_to_section(pfn)->pageblock_flags;
4743 return zone->pageblock_flags;
4744 #endif /* CONFIG_SPARSEMEM */
4747 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
4749 #ifdef CONFIG_SPARSEMEM
4750 pfn &= (PAGES_PER_SECTION-1);
4751 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4753 pfn = pfn - zone->zone_start_pfn;
4754 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4755 #endif /* CONFIG_SPARSEMEM */
4759 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4760 * @page: The page within the block of interest
4761 * @start_bitidx: The first bit of interest to retrieve
4762 * @end_bitidx: The last bit of interest
4763 * returns pageblock_bits flags
4765 unsigned long get_pageblock_flags_group(struct page *page,
4766 int start_bitidx, int end_bitidx)
4769 unsigned long *bitmap;
4770 unsigned long pfn, bitidx;
4771 unsigned long flags = 0;
4772 unsigned long value = 1;
4774 zone = page_zone(page);
4775 pfn = page_to_pfn(page);
4776 bitmap = get_pageblock_bitmap(zone, pfn);
4777 bitidx = pfn_to_bitidx(zone, pfn);
4779 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4780 if (test_bit(bitidx + start_bitidx, bitmap))
4787 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4788 * @page: The page within the block of interest
4789 * @start_bitidx: The first bit of interest
4790 * @end_bitidx: The last bit of interest
4791 * @flags: The flags to set
4793 void set_pageblock_flags_group(struct page *page, unsigned long flags,
4794 int start_bitidx, int end_bitidx)
4797 unsigned long *bitmap;
4798 unsigned long pfn, bitidx;
4799 unsigned long value = 1;
4801 zone = page_zone(page);
4802 pfn = page_to_pfn(page);
4803 bitmap = get_pageblock_bitmap(zone, pfn);
4804 bitidx = pfn_to_bitidx(zone, pfn);
4805 VM_BUG_ON(pfn < zone->zone_start_pfn);
4806 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4808 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4810 __set_bit(bitidx + start_bitidx, bitmap);
4812 __clear_bit(bitidx + start_bitidx, bitmap);
4816 * This is designed as sub function...plz see page_isolation.c also.
4817 * set/clear page block's type to be ISOLATE.
4818 * page allocater never alloc memory from ISOLATE block.
4821 int set_migratetype_isolate(struct page *page)
4824 unsigned long flags;
4827 zone = page_zone(page);
4828 spin_lock_irqsave(&zone->lock, flags);
4830 * In future, more migrate types will be able to be isolation target.
4832 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
4834 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
4835 move_freepages_block(zone, page, MIGRATE_ISOLATE);
4838 spin_unlock_irqrestore(&zone->lock, flags);
4844 void unset_migratetype_isolate(struct page *page)
4847 unsigned long flags;
4848 zone = page_zone(page);
4849 spin_lock_irqsave(&zone->lock, flags);
4850 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
4852 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4853 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4855 spin_unlock_irqrestore(&zone->lock, flags);
4858 #ifdef CONFIG_MEMORY_HOTREMOVE
4860 * All pages in the range must be isolated before calling this.
4863 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
4869 unsigned long flags;
4870 /* find the first valid pfn */
4871 for (pfn = start_pfn; pfn < end_pfn; pfn++)
4876 zone = page_zone(pfn_to_page(pfn));
4877 spin_lock_irqsave(&zone->lock, flags);
4879 while (pfn < end_pfn) {
4880 if (!pfn_valid(pfn)) {
4884 page = pfn_to_page(pfn);
4885 BUG_ON(page_count(page));
4886 BUG_ON(!PageBuddy(page));
4887 order = page_order(page);
4888 #ifdef CONFIG_DEBUG_VM
4889 printk(KERN_INFO "remove from free list %lx %d %lx\n",
4890 pfn, 1 << order, end_pfn);
4892 list_del(&page->lru);
4893 rmv_page_order(page);
4894 zone->free_area[order].nr_free--;
4895 __mod_zone_page_state(zone, NR_FREE_PAGES,
4897 for (i = 0; i < (1 << order); i++)
4898 SetPageReserved((page+i));
4899 pfn += (1 << order);
4901 spin_unlock_irqrestore(&zone->lock, flags);