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/kmemcheck.h>
27 #include <linux/module.h>
28 #include <linux/suspend.h>
29 #include <linux/pagevec.h>
30 #include <linux/blkdev.h>
31 #include <linux/slab.h>
32 #include <linux/oom.h>
33 #include <linux/notifier.h>
34 #include <linux/topology.h>
35 #include <linux/sysctl.h>
36 #include <linux/cpu.h>
37 #include <linux/cpuset.h>
38 #include <linux/memory_hotplug.h>
39 #include <linux/nodemask.h>
40 #include <linux/vmalloc.h>
41 #include <linux/mempolicy.h>
42 #include <linux/stop_machine.h>
43 #include <linux/sort.h>
44 #include <linux/pfn.h>
45 #include <linux/backing-dev.h>
46 #include <linux/fault-inject.h>
47 #include <linux/page-isolation.h>
48 #include <linux/page_cgroup.h>
49 #include <linux/debugobjects.h>
50 #include <linux/kmemleak.h>
51 #include <trace/events/kmem.h>
53 #include <asm/tlbflush.h>
54 #include <asm/div64.h>
58 * Array of node states.
60 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
61 [N_POSSIBLE] = NODE_MASK_ALL,
62 [N_ONLINE] = { { [0] = 1UL } },
64 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
66 [N_HIGH_MEMORY] = { { [0] = 1UL } },
68 [N_CPU] = { { [0] = 1UL } },
71 EXPORT_SYMBOL(node_states);
73 unsigned long totalram_pages __read_mostly;
74 unsigned long totalreserve_pages __read_mostly;
75 unsigned long highest_memmap_pfn __read_mostly;
76 int percpu_pagelist_fraction;
77 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
79 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
80 int pageblock_order __read_mostly;
83 static void __free_pages_ok(struct page *page, unsigned int order);
86 * results with 256, 32 in the lowmem_reserve sysctl:
87 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
88 * 1G machine -> (16M dma, 784M normal, 224M high)
89 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
90 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
91 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
93 * TBD: should special case ZONE_DMA32 machines here - in those we normally
94 * don't need any ZONE_NORMAL reservation
96 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
97 #ifdef CONFIG_ZONE_DMA
100 #ifdef CONFIG_ZONE_DMA32
103 #ifdef CONFIG_HIGHMEM
109 EXPORT_SYMBOL(totalram_pages);
111 static char * const zone_names[MAX_NR_ZONES] = {
112 #ifdef CONFIG_ZONE_DMA
115 #ifdef CONFIG_ZONE_DMA32
119 #ifdef CONFIG_HIGHMEM
125 int min_free_kbytes = 1024;
127 static unsigned long __meminitdata nr_kernel_pages;
128 static unsigned long __meminitdata nr_all_pages;
129 static unsigned long __meminitdata dma_reserve;
131 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
133 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
134 * ranges of memory (RAM) that may be registered with add_active_range().
135 * Ranges passed to add_active_range() will be merged if possible
136 * so the number of times add_active_range() can be called is
137 * related to the number of nodes and the number of holes
139 #ifdef CONFIG_MAX_ACTIVE_REGIONS
140 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
141 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
143 #if MAX_NUMNODES >= 32
144 /* If there can be many nodes, allow up to 50 holes per node */
145 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
147 /* By default, allow up to 256 distinct regions */
148 #define MAX_ACTIVE_REGIONS 256
152 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
153 static int __meminitdata nr_nodemap_entries;
154 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
155 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
156 static unsigned long __initdata required_kernelcore;
157 static unsigned long __initdata required_movablecore;
158 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
160 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
162 EXPORT_SYMBOL(movable_zone);
163 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
166 int nr_node_ids __read_mostly = MAX_NUMNODES;
167 int nr_online_nodes __read_mostly = 1;
168 EXPORT_SYMBOL(nr_node_ids);
169 EXPORT_SYMBOL(nr_online_nodes);
172 int page_group_by_mobility_disabled __read_mostly;
174 static void set_pageblock_migratetype(struct page *page, int migratetype)
177 if (unlikely(page_group_by_mobility_disabled))
178 migratetype = MIGRATE_UNMOVABLE;
180 set_pageblock_flags_group(page, (unsigned long)migratetype,
181 PB_migrate, PB_migrate_end);
184 bool oom_killer_disabled __read_mostly;
186 #ifdef CONFIG_DEBUG_VM
187 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
191 unsigned long pfn = page_to_pfn(page);
194 seq = zone_span_seqbegin(zone);
195 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
197 else if (pfn < zone->zone_start_pfn)
199 } while (zone_span_seqretry(zone, seq));
204 static int page_is_consistent(struct zone *zone, struct page *page)
206 if (!pfn_valid_within(page_to_pfn(page)))
208 if (zone != page_zone(page))
214 * Temporary debugging check for pages not lying within a given zone.
216 static int bad_range(struct zone *zone, struct page *page)
218 if (page_outside_zone_boundaries(zone, page))
220 if (!page_is_consistent(zone, page))
226 static inline int bad_range(struct zone *zone, struct page *page)
232 static void bad_page(struct page *page)
234 static unsigned long resume;
235 static unsigned long nr_shown;
236 static unsigned long nr_unshown;
239 * Allow a burst of 60 reports, then keep quiet for that minute;
240 * or allow a steady drip of one report per second.
242 if (nr_shown == 60) {
243 if (time_before(jiffies, resume)) {
249 "BUG: Bad page state: %lu messages suppressed\n",
256 resume = jiffies + 60 * HZ;
258 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
259 current->comm, page_to_pfn(page));
261 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
262 page, (void *)page->flags, page_count(page),
263 page_mapcount(page), page->mapping, page->index);
267 /* Leave bad fields for debug, except PageBuddy could make trouble */
268 __ClearPageBuddy(page);
269 add_taint(TAINT_BAD_PAGE);
273 * Higher-order pages are called "compound pages". They are structured thusly:
275 * The first PAGE_SIZE page is called the "head page".
277 * The remaining PAGE_SIZE pages are called "tail pages".
279 * All pages have PG_compound set. All pages have their ->private pointing at
280 * the head page (even the head page has this).
282 * The first tail page's ->lru.next holds the address of the compound page's
283 * put_page() function. Its ->lru.prev holds the order of allocation.
284 * This usage means that zero-order pages may not be compound.
287 static void free_compound_page(struct page *page)
289 __free_pages_ok(page, compound_order(page));
292 void prep_compound_page(struct page *page, unsigned long order)
295 int nr_pages = 1 << order;
297 set_compound_page_dtor(page, free_compound_page);
298 set_compound_order(page, order);
300 for (i = 1; i < nr_pages; i++) {
301 struct page *p = page + i;
304 p->first_page = page;
308 static int destroy_compound_page(struct page *page, unsigned long order)
311 int nr_pages = 1 << order;
314 if (unlikely(compound_order(page) != order) ||
315 unlikely(!PageHead(page))) {
320 __ClearPageHead(page);
322 for (i = 1; i < nr_pages; i++) {
323 struct page *p = page + i;
325 if (unlikely(!PageTail(p) || (p->first_page != page))) {
335 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
340 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
341 * and __GFP_HIGHMEM from hard or soft interrupt context.
343 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
344 for (i = 0; i < (1 << order); i++)
345 clear_highpage(page + i);
348 static inline void set_page_order(struct page *page, int order)
350 set_page_private(page, order);
351 __SetPageBuddy(page);
354 static inline void rmv_page_order(struct page *page)
356 __ClearPageBuddy(page);
357 set_page_private(page, 0);
361 * Locate the struct page for both the matching buddy in our
362 * pair (buddy1) and the combined O(n+1) page they form (page).
364 * 1) Any buddy B1 will have an order O twin B2 which satisfies
365 * the following equation:
367 * For example, if the starting buddy (buddy2) is #8 its order
369 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
371 * 2) Any buddy B will have an order O+1 parent P which
372 * satisfies the following equation:
375 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
377 static inline struct page *
378 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
380 unsigned long buddy_idx = page_idx ^ (1 << order);
382 return page + (buddy_idx - page_idx);
385 static inline unsigned long
386 __find_combined_index(unsigned long page_idx, unsigned int order)
388 return (page_idx & ~(1 << order));
392 * This function checks whether a page is free && is the buddy
393 * we can do coalesce a page and its buddy if
394 * (a) the buddy is not in a hole &&
395 * (b) the buddy is in the buddy system &&
396 * (c) a page and its buddy have the same order &&
397 * (d) a page and its buddy are in the same zone.
399 * For recording whether a page is in the buddy system, we use PG_buddy.
400 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
402 * For recording page's order, we use page_private(page).
404 static inline int page_is_buddy(struct page *page, struct page *buddy,
407 if (!pfn_valid_within(page_to_pfn(buddy)))
410 if (page_zone_id(page) != page_zone_id(buddy))
413 if (PageBuddy(buddy) && page_order(buddy) == order) {
414 VM_BUG_ON(page_count(buddy) != 0);
421 * Freeing function for a buddy system allocator.
423 * The concept of a buddy system is to maintain direct-mapped table
424 * (containing bit values) for memory blocks of various "orders".
425 * The bottom level table contains the map for the smallest allocatable
426 * units of memory (here, pages), and each level above it describes
427 * pairs of units from the levels below, hence, "buddies".
428 * At a high level, all that happens here is marking the table entry
429 * at the bottom level available, and propagating the changes upward
430 * as necessary, plus some accounting needed to play nicely with other
431 * parts of the VM system.
432 * At each level, we keep a list of pages, which are heads of continuous
433 * free pages of length of (1 << order) and marked with PG_buddy. Page's
434 * order is recorded in page_private(page) field.
435 * So when we are allocating or freeing one, we can derive the state of the
436 * other. That is, if we allocate a small block, and both were
437 * free, the remainder of the region must be split into blocks.
438 * If a block is freed, and its buddy is also free, then this
439 * triggers coalescing into a block of larger size.
444 static inline void __free_one_page(struct page *page,
445 struct zone *zone, unsigned int order,
448 unsigned long page_idx;
450 if (unlikely(PageCompound(page)))
451 if (unlikely(destroy_compound_page(page, order)))
454 VM_BUG_ON(migratetype == -1);
456 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
458 VM_BUG_ON(page_idx & ((1 << order) - 1));
459 VM_BUG_ON(bad_range(zone, page));
461 while (order < MAX_ORDER-1) {
462 unsigned long combined_idx;
465 buddy = __page_find_buddy(page, page_idx, order);
466 if (!page_is_buddy(page, buddy, order))
469 /* Our buddy is free, merge with it and move up one order. */
470 list_del(&buddy->lru);
471 zone->free_area[order].nr_free--;
472 rmv_page_order(buddy);
473 combined_idx = __find_combined_index(page_idx, order);
474 page = page + (combined_idx - page_idx);
475 page_idx = combined_idx;
478 set_page_order(page, order);
480 &zone->free_area[order].free_list[migratetype]);
481 zone->free_area[order].nr_free++;
484 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
486 * free_page_mlock() -- clean up attempts to free and mlocked() page.
487 * Page should not be on lru, so no need to fix that up.
488 * free_pages_check() will verify...
490 static inline void free_page_mlock(struct page *page)
492 __dec_zone_page_state(page, NR_MLOCK);
493 __count_vm_event(UNEVICTABLE_MLOCKFREED);
496 static void free_page_mlock(struct page *page) { }
499 static inline int free_pages_check(struct page *page)
501 if (unlikely(page_mapcount(page) |
502 (page->mapping != NULL) |
503 (atomic_read(&page->_count) != 0) |
504 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
508 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
509 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
514 * Frees a number of pages from the PCP lists
515 * Assumes all pages on list are in same zone, and of same order.
516 * count is the number of pages to free.
518 * If the zone was previously in an "all pages pinned" state then look to
519 * see if this freeing clears that state.
521 * And clear the zone's pages_scanned counter, to hold off the "all pages are
522 * pinned" detection logic.
524 static void free_pcppages_bulk(struct zone *zone, int count,
525 struct per_cpu_pages *pcp)
529 spin_lock(&zone->lock);
530 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
531 zone->pages_scanned = 0;
533 __mod_zone_page_state(zone, NR_FREE_PAGES, count);
536 struct list_head *list;
539 * Remove pages from lists in a round-robin fashion. This spinning
540 * around potentially empty lists is bloody awful, alternatives that
541 * don't suck are welcome
544 if (++migratetype == MIGRATE_PCPTYPES)
546 list = &pcp->lists[migratetype];
547 } while (list_empty(list));
549 page = list_entry(list->prev, struct page, lru);
550 /* have to delete it as __free_one_page list manipulates */
551 list_del(&page->lru);
552 trace_mm_page_pcpu_drain(page, 0, migratetype);
553 __free_one_page(page, zone, 0, migratetype);
555 spin_unlock(&zone->lock);
558 static void free_one_page(struct zone *zone, struct page *page, int order,
561 spin_lock(&zone->lock);
562 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
563 zone->pages_scanned = 0;
565 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
566 __free_one_page(page, zone, order, migratetype);
567 spin_unlock(&zone->lock);
570 static void __free_pages_ok(struct page *page, unsigned int order)
575 int wasMlocked = __TestClearPageMlocked(page);
577 kmemcheck_free_shadow(page, order);
579 for (i = 0 ; i < (1 << order) ; ++i)
580 bad += free_pages_check(page + i);
584 if (!PageHighMem(page)) {
585 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
586 debug_check_no_obj_freed(page_address(page),
589 arch_free_page(page, order);
590 kernel_map_pages(page, 1 << order, 0);
592 local_irq_save(flags);
593 if (unlikely(wasMlocked))
594 free_page_mlock(page);
595 __count_vm_events(PGFREE, 1 << order);
596 free_one_page(page_zone(page), page, order,
597 get_pageblock_migratetype(page));
598 local_irq_restore(flags);
602 * permit the bootmem allocator to evade page validation on high-order frees
604 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
607 __ClearPageReserved(page);
608 set_page_count(page, 0);
609 set_page_refcounted(page);
615 for (loop = 0; loop < BITS_PER_LONG; loop++) {
616 struct page *p = &page[loop];
618 if (loop + 1 < BITS_PER_LONG)
620 __ClearPageReserved(p);
621 set_page_count(p, 0);
624 set_page_refcounted(page);
625 __free_pages(page, order);
631 * The order of subdivision here is critical for the IO subsystem.
632 * Please do not alter this order without good reasons and regression
633 * testing. Specifically, as large blocks of memory are subdivided,
634 * the order in which smaller blocks are delivered depends on the order
635 * they're subdivided in this function. This is the primary factor
636 * influencing the order in which pages are delivered to the IO
637 * subsystem according to empirical testing, and this is also justified
638 * by considering the behavior of a buddy system containing a single
639 * large block of memory acted on by a series of small allocations.
640 * This behavior is a critical factor in sglist merging's success.
644 static inline void expand(struct zone *zone, struct page *page,
645 int low, int high, struct free_area *area,
648 unsigned long size = 1 << high;
654 VM_BUG_ON(bad_range(zone, &page[size]));
655 list_add(&page[size].lru, &area->free_list[migratetype]);
657 set_page_order(&page[size], high);
662 * This page is about to be returned from the page allocator
664 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
666 if (unlikely(page_mapcount(page) |
667 (page->mapping != NULL) |
668 (atomic_read(&page->_count) != 0) |
669 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
674 set_page_private(page, 0);
675 set_page_refcounted(page);
677 arch_alloc_page(page, order);
678 kernel_map_pages(page, 1 << order, 1);
680 if (gfp_flags & __GFP_ZERO)
681 prep_zero_page(page, order, gfp_flags);
683 if (order && (gfp_flags & __GFP_COMP))
684 prep_compound_page(page, order);
690 * Go through the free lists for the given migratetype and remove
691 * the smallest available page from the freelists
694 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
697 unsigned int current_order;
698 struct free_area * area;
701 /* Find a page of the appropriate size in the preferred list */
702 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
703 area = &(zone->free_area[current_order]);
704 if (list_empty(&area->free_list[migratetype]))
707 page = list_entry(area->free_list[migratetype].next,
709 list_del(&page->lru);
710 rmv_page_order(page);
712 expand(zone, page, order, current_order, area, migratetype);
721 * This array describes the order lists are fallen back to when
722 * the free lists for the desirable migrate type are depleted
724 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
725 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
726 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
727 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
728 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
732 * Move the free pages in a range to the free lists of the requested type.
733 * Note that start_page and end_pages are not aligned on a pageblock
734 * boundary. If alignment is required, use move_freepages_block()
736 static int move_freepages(struct zone *zone,
737 struct page *start_page, struct page *end_page,
744 #ifndef CONFIG_HOLES_IN_ZONE
746 * page_zone is not safe to call in this context when
747 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
748 * anyway as we check zone boundaries in move_freepages_block().
749 * Remove at a later date when no bug reports exist related to
750 * grouping pages by mobility
752 BUG_ON(page_zone(start_page) != page_zone(end_page));
755 for (page = start_page; page <= end_page;) {
756 /* Make sure we are not inadvertently changing nodes */
757 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
759 if (!pfn_valid_within(page_to_pfn(page))) {
764 if (!PageBuddy(page)) {
769 order = page_order(page);
770 list_del(&page->lru);
772 &zone->free_area[order].free_list[migratetype]);
774 pages_moved += 1 << order;
780 static int move_freepages_block(struct zone *zone, struct page *page,
783 unsigned long start_pfn, end_pfn;
784 struct page *start_page, *end_page;
786 start_pfn = page_to_pfn(page);
787 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
788 start_page = pfn_to_page(start_pfn);
789 end_page = start_page + pageblock_nr_pages - 1;
790 end_pfn = start_pfn + pageblock_nr_pages - 1;
792 /* Do not cross zone boundaries */
793 if (start_pfn < zone->zone_start_pfn)
795 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
798 return move_freepages(zone, start_page, end_page, migratetype);
801 static void change_pageblock_range(struct page *pageblock_page,
802 int start_order, int migratetype)
804 int nr_pageblocks = 1 << (start_order - pageblock_order);
806 while (nr_pageblocks--) {
807 set_pageblock_migratetype(pageblock_page, migratetype);
808 pageblock_page += pageblock_nr_pages;
812 /* Remove an element from the buddy allocator from the fallback list */
813 static inline struct page *
814 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
816 struct free_area * area;
821 /* Find the largest possible block of pages in the other list */
822 for (current_order = MAX_ORDER-1; current_order >= order;
824 for (i = 0; i < MIGRATE_TYPES - 1; i++) {
825 migratetype = fallbacks[start_migratetype][i];
827 /* MIGRATE_RESERVE handled later if necessary */
828 if (migratetype == MIGRATE_RESERVE)
831 area = &(zone->free_area[current_order]);
832 if (list_empty(&area->free_list[migratetype]))
835 page = list_entry(area->free_list[migratetype].next,
840 * If breaking a large block of pages, move all free
841 * pages to the preferred allocation list. If falling
842 * back for a reclaimable kernel allocation, be more
843 * agressive about taking ownership of free pages
845 if (unlikely(current_order >= (pageblock_order >> 1)) ||
846 start_migratetype == MIGRATE_RECLAIMABLE ||
847 page_group_by_mobility_disabled) {
849 pages = move_freepages_block(zone, page,
852 /* Claim the whole block if over half of it is free */
853 if (pages >= (1 << (pageblock_order-1)) ||
854 page_group_by_mobility_disabled)
855 set_pageblock_migratetype(page,
858 migratetype = start_migratetype;
861 /* Remove the page from the freelists */
862 list_del(&page->lru);
863 rmv_page_order(page);
865 /* Take ownership for orders >= pageblock_order */
866 if (current_order >= pageblock_order)
867 change_pageblock_range(page, current_order,
870 expand(zone, page, order, current_order, area, migratetype);
872 trace_mm_page_alloc_extfrag(page, order, current_order,
873 start_migratetype, migratetype);
883 * Do the hard work of removing an element from the buddy allocator.
884 * Call me with the zone->lock already held.
886 static struct page *__rmqueue(struct zone *zone, unsigned int order,
892 page = __rmqueue_smallest(zone, order, migratetype);
894 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
895 page = __rmqueue_fallback(zone, order, migratetype);
898 * Use MIGRATE_RESERVE rather than fail an allocation. goto
899 * is used because __rmqueue_smallest is an inline function
900 * and we want just one call site
903 migratetype = MIGRATE_RESERVE;
908 trace_mm_page_alloc_zone_locked(page, order, migratetype);
913 * Obtain a specified number of elements from the buddy allocator, all under
914 * a single hold of the lock, for efficiency. Add them to the supplied list.
915 * Returns the number of new pages which were placed at *list.
917 static int rmqueue_bulk(struct zone *zone, unsigned int order,
918 unsigned long count, struct list_head *list,
919 int migratetype, int cold)
923 spin_lock(&zone->lock);
924 for (i = 0; i < count; ++i) {
925 struct page *page = __rmqueue(zone, order, migratetype);
926 if (unlikely(page == NULL))
930 * Split buddy pages returned by expand() are received here
931 * in physical page order. The page is added to the callers and
932 * list and the list head then moves forward. From the callers
933 * perspective, the linked list is ordered by page number in
934 * some conditions. This is useful for IO devices that can
935 * merge IO requests if the physical pages are ordered
938 if (likely(cold == 0))
939 list_add(&page->lru, list);
941 list_add_tail(&page->lru, list);
942 set_page_private(page, migratetype);
945 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
946 spin_unlock(&zone->lock);
952 * Called from the vmstat counter updater to drain pagesets of this
953 * currently executing processor on remote nodes after they have
956 * Note that this function must be called with the thread pinned to
957 * a single processor.
959 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
964 local_irq_save(flags);
965 if (pcp->count >= pcp->batch)
966 to_drain = pcp->batch;
968 to_drain = pcp->count;
969 free_pcppages_bulk(zone, to_drain, pcp);
970 pcp->count -= to_drain;
971 local_irq_restore(flags);
976 * Drain pages of the indicated processor.
978 * The processor must either be the current processor and the
979 * thread pinned to the current processor or a processor that
982 static void drain_pages(unsigned int cpu)
987 for_each_populated_zone(zone) {
988 struct per_cpu_pageset *pset;
989 struct per_cpu_pages *pcp;
991 pset = zone_pcp(zone, cpu);
994 local_irq_save(flags);
995 free_pcppages_bulk(zone, pcp->count, pcp);
997 local_irq_restore(flags);
1002 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1004 void drain_local_pages(void *arg)
1006 drain_pages(smp_processor_id());
1010 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1012 void drain_all_pages(void)
1014 on_each_cpu(drain_local_pages, NULL, 1);
1017 #ifdef CONFIG_HIBERNATION
1019 void mark_free_pages(struct zone *zone)
1021 unsigned long pfn, max_zone_pfn;
1022 unsigned long flags;
1024 struct list_head *curr;
1026 if (!zone->spanned_pages)
1029 spin_lock_irqsave(&zone->lock, flags);
1031 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1032 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1033 if (pfn_valid(pfn)) {
1034 struct page *page = pfn_to_page(pfn);
1036 if (!swsusp_page_is_forbidden(page))
1037 swsusp_unset_page_free(page);
1040 for_each_migratetype_order(order, t) {
1041 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1044 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1045 for (i = 0; i < (1UL << order); i++)
1046 swsusp_set_page_free(pfn_to_page(pfn + i));
1049 spin_unlock_irqrestore(&zone->lock, flags);
1051 #endif /* CONFIG_PM */
1054 * Free a 0-order page
1056 static void free_hot_cold_page(struct page *page, int cold)
1058 struct zone *zone = page_zone(page);
1059 struct per_cpu_pages *pcp;
1060 unsigned long flags;
1062 int wasMlocked = __TestClearPageMlocked(page);
1064 kmemcheck_free_shadow(page, 0);
1067 page->mapping = NULL;
1068 if (free_pages_check(page))
1071 if (!PageHighMem(page)) {
1072 debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1073 debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
1075 arch_free_page(page, 0);
1076 kernel_map_pages(page, 1, 0);
1078 pcp = &zone_pcp(zone, get_cpu())->pcp;
1079 migratetype = get_pageblock_migratetype(page);
1080 set_page_private(page, migratetype);
1081 local_irq_save(flags);
1082 if (unlikely(wasMlocked))
1083 free_page_mlock(page);
1084 __count_vm_event(PGFREE);
1087 * We only track unmovable, reclaimable and movable on pcp lists.
1088 * Free ISOLATE pages back to the allocator because they are being
1089 * offlined but treat RESERVE as movable pages so we can get those
1090 * areas back if necessary. Otherwise, we may have to free
1091 * excessively into the page allocator
1093 if (migratetype >= MIGRATE_PCPTYPES) {
1094 if (unlikely(migratetype == MIGRATE_ISOLATE)) {
1095 free_one_page(zone, page, 0, migratetype);
1098 migratetype = MIGRATE_MOVABLE;
1102 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1104 list_add(&page->lru, &pcp->lists[migratetype]);
1106 if (pcp->count >= pcp->high) {
1107 free_pcppages_bulk(zone, pcp->batch, pcp);
1108 pcp->count -= pcp->batch;
1112 local_irq_restore(flags);
1116 void free_hot_page(struct page *page)
1118 trace_mm_page_free_direct(page, 0);
1119 free_hot_cold_page(page, 0);
1123 * split_page takes a non-compound higher-order page, and splits it into
1124 * n (1<<order) sub-pages: page[0..n]
1125 * Each sub-page must be freed individually.
1127 * Note: this is probably too low level an operation for use in drivers.
1128 * Please consult with lkml before using this in your driver.
1130 void split_page(struct page *page, unsigned int order)
1134 VM_BUG_ON(PageCompound(page));
1135 VM_BUG_ON(!page_count(page));
1137 #ifdef CONFIG_KMEMCHECK
1139 * Split shadow pages too, because free(page[0]) would
1140 * otherwise free the whole shadow.
1142 if (kmemcheck_page_is_tracked(page))
1143 split_page(virt_to_page(page[0].shadow), order);
1146 for (i = 1; i < (1 << order); i++)
1147 set_page_refcounted(page + i);
1151 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1152 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1156 struct page *buffered_rmqueue(struct zone *preferred_zone,
1157 struct zone *zone, int order, gfp_t gfp_flags,
1160 unsigned long flags;
1162 int cold = !!(gfp_flags & __GFP_COLD);
1167 if (likely(order == 0)) {
1168 struct per_cpu_pages *pcp;
1169 struct list_head *list;
1171 pcp = &zone_pcp(zone, cpu)->pcp;
1172 list = &pcp->lists[migratetype];
1173 local_irq_save(flags);
1174 if (list_empty(list)) {
1175 pcp->count += rmqueue_bulk(zone, 0,
1178 if (unlikely(list_empty(list)))
1183 page = list_entry(list->prev, struct page, lru);
1185 page = list_entry(list->next, struct page, lru);
1187 list_del(&page->lru);
1190 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1192 * __GFP_NOFAIL is not to be used in new code.
1194 * All __GFP_NOFAIL callers should be fixed so that they
1195 * properly detect and handle allocation failures.
1197 * We most definitely don't want callers attempting to
1198 * allocate greater than order-1 page units with
1201 WARN_ON_ONCE(order > 1);
1203 spin_lock_irqsave(&zone->lock, flags);
1204 page = __rmqueue(zone, order, migratetype);
1205 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
1206 spin_unlock(&zone->lock);
1211 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1212 zone_statistics(preferred_zone, zone);
1213 local_irq_restore(flags);
1216 VM_BUG_ON(bad_range(zone, page));
1217 if (prep_new_page(page, order, gfp_flags))
1222 local_irq_restore(flags);
1227 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1228 #define ALLOC_WMARK_MIN WMARK_MIN
1229 #define ALLOC_WMARK_LOW WMARK_LOW
1230 #define ALLOC_WMARK_HIGH WMARK_HIGH
1231 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1233 /* Mask to get the watermark bits */
1234 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1236 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1237 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1238 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1240 #ifdef CONFIG_FAIL_PAGE_ALLOC
1242 static struct fail_page_alloc_attr {
1243 struct fault_attr attr;
1245 u32 ignore_gfp_highmem;
1246 u32 ignore_gfp_wait;
1249 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1251 struct dentry *ignore_gfp_highmem_file;
1252 struct dentry *ignore_gfp_wait_file;
1253 struct dentry *min_order_file;
1255 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1257 } fail_page_alloc = {
1258 .attr = FAULT_ATTR_INITIALIZER,
1259 .ignore_gfp_wait = 1,
1260 .ignore_gfp_highmem = 1,
1264 static int __init setup_fail_page_alloc(char *str)
1266 return setup_fault_attr(&fail_page_alloc.attr, str);
1268 __setup("fail_page_alloc=", setup_fail_page_alloc);
1270 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1272 if (order < fail_page_alloc.min_order)
1274 if (gfp_mask & __GFP_NOFAIL)
1276 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1278 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1281 return should_fail(&fail_page_alloc.attr, 1 << order);
1284 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1286 static int __init fail_page_alloc_debugfs(void)
1288 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1292 err = init_fault_attr_dentries(&fail_page_alloc.attr,
1296 dir = fail_page_alloc.attr.dentries.dir;
1298 fail_page_alloc.ignore_gfp_wait_file =
1299 debugfs_create_bool("ignore-gfp-wait", mode, dir,
1300 &fail_page_alloc.ignore_gfp_wait);
1302 fail_page_alloc.ignore_gfp_highmem_file =
1303 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1304 &fail_page_alloc.ignore_gfp_highmem);
1305 fail_page_alloc.min_order_file =
1306 debugfs_create_u32("min-order", mode, dir,
1307 &fail_page_alloc.min_order);
1309 if (!fail_page_alloc.ignore_gfp_wait_file ||
1310 !fail_page_alloc.ignore_gfp_highmem_file ||
1311 !fail_page_alloc.min_order_file) {
1313 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
1314 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1315 debugfs_remove(fail_page_alloc.min_order_file);
1316 cleanup_fault_attr_dentries(&fail_page_alloc.attr);
1322 late_initcall(fail_page_alloc_debugfs);
1324 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1326 #else /* CONFIG_FAIL_PAGE_ALLOC */
1328 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1333 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1336 * Return 1 if free pages are above 'mark'. This takes into account the order
1337 * of the allocation.
1339 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1340 int classzone_idx, int alloc_flags)
1342 /* free_pages my go negative - that's OK */
1344 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
1347 if (alloc_flags & ALLOC_HIGH)
1349 if (alloc_flags & ALLOC_HARDER)
1352 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1354 for (o = 0; o < order; o++) {
1355 /* At the next order, this order's pages become unavailable */
1356 free_pages -= z->free_area[o].nr_free << o;
1358 /* Require fewer higher order pages to be free */
1361 if (free_pages <= min)
1369 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1370 * skip over zones that are not allowed by the cpuset, or that have
1371 * been recently (in last second) found to be nearly full. See further
1372 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1373 * that have to skip over a lot of full or unallowed zones.
1375 * If the zonelist cache is present in the passed in zonelist, then
1376 * returns a pointer to the allowed node mask (either the current
1377 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1379 * If the zonelist cache is not available for this zonelist, does
1380 * nothing and returns NULL.
1382 * If the fullzones BITMAP in the zonelist cache is stale (more than
1383 * a second since last zap'd) then we zap it out (clear its bits.)
1385 * We hold off even calling zlc_setup, until after we've checked the
1386 * first zone in the zonelist, on the theory that most allocations will
1387 * be satisfied from that first zone, so best to examine that zone as
1388 * quickly as we can.
1390 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1392 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1393 nodemask_t *allowednodes; /* zonelist_cache approximation */
1395 zlc = zonelist->zlcache_ptr;
1399 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1400 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1401 zlc->last_full_zap = jiffies;
1404 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1405 &cpuset_current_mems_allowed :
1406 &node_states[N_HIGH_MEMORY];
1407 return allowednodes;
1411 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1412 * if it is worth looking at further for free memory:
1413 * 1) Check that the zone isn't thought to be full (doesn't have its
1414 * bit set in the zonelist_cache fullzones BITMAP).
1415 * 2) Check that the zones node (obtained from the zonelist_cache
1416 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1417 * Return true (non-zero) if zone is worth looking at further, or
1418 * else return false (zero) if it is not.
1420 * This check -ignores- the distinction between various watermarks,
1421 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1422 * found to be full for any variation of these watermarks, it will
1423 * be considered full for up to one second by all requests, unless
1424 * we are so low on memory on all allowed nodes that we are forced
1425 * into the second scan of the zonelist.
1427 * In the second scan we ignore this zonelist cache and exactly
1428 * apply the watermarks to all zones, even it is slower to do so.
1429 * We are low on memory in the second scan, and should leave no stone
1430 * unturned looking for a free page.
1432 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1433 nodemask_t *allowednodes)
1435 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1436 int i; /* index of *z in zonelist zones */
1437 int n; /* node that zone *z is on */
1439 zlc = zonelist->zlcache_ptr;
1443 i = z - zonelist->_zonerefs;
1446 /* This zone is worth trying if it is allowed but not full */
1447 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1451 * Given 'z' scanning a zonelist, set the corresponding bit in
1452 * zlc->fullzones, so that subsequent attempts to allocate a page
1453 * from that zone don't waste time re-examining it.
1455 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1457 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1458 int i; /* index of *z in zonelist zones */
1460 zlc = zonelist->zlcache_ptr;
1464 i = z - zonelist->_zonerefs;
1466 set_bit(i, zlc->fullzones);
1469 #else /* CONFIG_NUMA */
1471 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1476 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1477 nodemask_t *allowednodes)
1482 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1485 #endif /* CONFIG_NUMA */
1488 * get_page_from_freelist goes through the zonelist trying to allocate
1491 static struct page *
1492 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1493 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1494 struct zone *preferred_zone, int migratetype)
1497 struct page *page = NULL;
1500 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1501 int zlc_active = 0; /* set if using zonelist_cache */
1502 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1504 classzone_idx = zone_idx(preferred_zone);
1507 * Scan zonelist, looking for a zone with enough free.
1508 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1510 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1511 high_zoneidx, nodemask) {
1512 if (NUMA_BUILD && zlc_active &&
1513 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1515 if ((alloc_flags & ALLOC_CPUSET) &&
1516 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1519 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1520 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1524 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1525 if (zone_watermark_ok(zone, order, mark,
1526 classzone_idx, alloc_flags))
1529 if (zone_reclaim_mode == 0)
1530 goto this_zone_full;
1532 ret = zone_reclaim(zone, gfp_mask, order);
1534 case ZONE_RECLAIM_NOSCAN:
1537 case ZONE_RECLAIM_FULL:
1538 /* scanned but unreclaimable */
1539 goto this_zone_full;
1541 /* did we reclaim enough */
1542 if (!zone_watermark_ok(zone, order, mark,
1543 classzone_idx, alloc_flags))
1544 goto this_zone_full;
1549 page = buffered_rmqueue(preferred_zone, zone, order,
1550 gfp_mask, migratetype);
1555 zlc_mark_zone_full(zonelist, z);
1557 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1559 * we do zlc_setup after the first zone is tried but only
1560 * if there are multiple nodes make it worthwhile
1562 allowednodes = zlc_setup(zonelist, alloc_flags);
1568 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1569 /* Disable zlc cache for second zonelist scan */
1577 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
1578 unsigned long pages_reclaimed)
1580 /* Do not loop if specifically requested */
1581 if (gfp_mask & __GFP_NORETRY)
1585 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1586 * means __GFP_NOFAIL, but that may not be true in other
1589 if (order <= PAGE_ALLOC_COSTLY_ORDER)
1593 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1594 * specified, then we retry until we no longer reclaim any pages
1595 * (above), or we've reclaimed an order of pages at least as
1596 * large as the allocation's order. In both cases, if the
1597 * allocation still fails, we stop retrying.
1599 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
1603 * Don't let big-order allocations loop unless the caller
1604 * explicitly requests that.
1606 if (gfp_mask & __GFP_NOFAIL)
1612 static inline struct page *
1613 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
1614 struct zonelist *zonelist, enum zone_type high_zoneidx,
1615 nodemask_t *nodemask, struct zone *preferred_zone,
1620 /* Acquire the OOM killer lock for the zones in zonelist */
1621 if (!try_set_zone_oom(zonelist, gfp_mask)) {
1622 schedule_timeout_uninterruptible(1);
1627 * Go through the zonelist yet one more time, keep very high watermark
1628 * here, this is only to catch a parallel oom killing, we must fail if
1629 * we're still under heavy pressure.
1631 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
1632 order, zonelist, high_zoneidx,
1633 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1634 preferred_zone, migratetype);
1638 /* The OOM killer will not help higher order allocs */
1639 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))
1642 /* Exhausted what can be done so it's blamo time */
1643 out_of_memory(zonelist, gfp_mask, order);
1646 clear_zonelist_oom(zonelist, gfp_mask);
1650 /* The really slow allocator path where we enter direct reclaim */
1651 static inline struct page *
1652 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
1653 struct zonelist *zonelist, enum zone_type high_zoneidx,
1654 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1655 int migratetype, unsigned long *did_some_progress)
1657 struct page *page = NULL;
1658 struct reclaim_state reclaim_state;
1659 struct task_struct *p = current;
1663 /* We now go into synchronous reclaim */
1664 cpuset_memory_pressure_bump();
1665 p->flags |= PF_MEMALLOC;
1666 lockdep_set_current_reclaim_state(gfp_mask);
1667 reclaim_state.reclaimed_slab = 0;
1668 p->reclaim_state = &reclaim_state;
1670 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
1672 p->reclaim_state = NULL;
1673 lockdep_clear_current_reclaim_state();
1674 p->flags &= ~PF_MEMALLOC;
1681 if (likely(*did_some_progress))
1682 page = get_page_from_freelist(gfp_mask, nodemask, order,
1683 zonelist, high_zoneidx,
1684 alloc_flags, preferred_zone,
1690 * This is called in the allocator slow-path if the allocation request is of
1691 * sufficient urgency to ignore watermarks and take other desperate measures
1693 static inline struct page *
1694 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
1695 struct zonelist *zonelist, enum zone_type high_zoneidx,
1696 nodemask_t *nodemask, struct zone *preferred_zone,
1702 page = get_page_from_freelist(gfp_mask, nodemask, order,
1703 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1704 preferred_zone, migratetype);
1706 if (!page && gfp_mask & __GFP_NOFAIL)
1707 congestion_wait(BLK_RW_ASYNC, HZ/50);
1708 } while (!page && (gfp_mask & __GFP_NOFAIL));
1714 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
1715 enum zone_type high_zoneidx)
1720 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
1721 wakeup_kswapd(zone, order);
1725 gfp_to_alloc_flags(gfp_t gfp_mask)
1727 struct task_struct *p = current;
1728 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
1729 const gfp_t wait = gfp_mask & __GFP_WAIT;
1731 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1732 BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1735 * The caller may dip into page reserves a bit more if the caller
1736 * cannot run direct reclaim, or if the caller has realtime scheduling
1737 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1738 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1740 alloc_flags |= (gfp_mask & __GFP_HIGH);
1743 alloc_flags |= ALLOC_HARDER;
1745 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1746 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1748 alloc_flags &= ~ALLOC_CPUSET;
1749 } else if (unlikely(rt_task(p)))
1750 alloc_flags |= ALLOC_HARDER;
1752 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
1753 if (!in_interrupt() &&
1754 ((p->flags & PF_MEMALLOC) ||
1755 unlikely(test_thread_flag(TIF_MEMDIE))))
1756 alloc_flags |= ALLOC_NO_WATERMARKS;
1762 static inline struct page *
1763 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
1764 struct zonelist *zonelist, enum zone_type high_zoneidx,
1765 nodemask_t *nodemask, struct zone *preferred_zone,
1768 const gfp_t wait = gfp_mask & __GFP_WAIT;
1769 struct page *page = NULL;
1771 unsigned long pages_reclaimed = 0;
1772 unsigned long did_some_progress;
1773 struct task_struct *p = current;
1776 * In the slowpath, we sanity check order to avoid ever trying to
1777 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
1778 * be using allocators in order of preference for an area that is
1781 if (order >= MAX_ORDER) {
1782 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1787 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1788 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1789 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1790 * using a larger set of nodes after it has established that the
1791 * allowed per node queues are empty and that nodes are
1794 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
1797 wake_all_kswapd(order, zonelist, high_zoneidx);
1801 * OK, we're below the kswapd watermark and have kicked background
1802 * reclaim. Now things get more complex, so set up alloc_flags according
1803 * to how we want to proceed.
1805 alloc_flags = gfp_to_alloc_flags(gfp_mask);
1807 /* This is the last chance, in general, before the goto nopage. */
1808 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1809 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
1810 preferred_zone, migratetype);
1815 /* Allocate without watermarks if the context allows */
1816 if (alloc_flags & ALLOC_NO_WATERMARKS) {
1817 page = __alloc_pages_high_priority(gfp_mask, order,
1818 zonelist, high_zoneidx, nodemask,
1819 preferred_zone, migratetype);
1824 /* Atomic allocations - we can't balance anything */
1828 /* Avoid recursion of direct reclaim */
1829 if (p->flags & PF_MEMALLOC)
1832 /* Avoid allocations with no watermarks from looping endlessly */
1833 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
1836 /* Try direct reclaim and then allocating */
1837 page = __alloc_pages_direct_reclaim(gfp_mask, order,
1838 zonelist, high_zoneidx,
1840 alloc_flags, preferred_zone,
1841 migratetype, &did_some_progress);
1846 * If we failed to make any progress reclaiming, then we are
1847 * running out of options and have to consider going OOM
1849 if (!did_some_progress) {
1850 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1851 if (oom_killer_disabled)
1853 page = __alloc_pages_may_oom(gfp_mask, order,
1854 zonelist, high_zoneidx,
1855 nodemask, preferred_zone,
1861 * The OOM killer does not trigger for high-order
1862 * ~__GFP_NOFAIL allocations so if no progress is being
1863 * made, there are no other options and retrying is
1866 if (order > PAGE_ALLOC_COSTLY_ORDER &&
1867 !(gfp_mask & __GFP_NOFAIL))
1874 /* Check if we should retry the allocation */
1875 pages_reclaimed += did_some_progress;
1876 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
1877 /* Wait for some write requests to complete then retry */
1878 congestion_wait(BLK_RW_ASYNC, HZ/50);
1883 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
1884 printk(KERN_WARNING "%s: page allocation failure."
1885 " order:%d, mode:0x%x\n",
1886 p->comm, order, gfp_mask);
1892 if (kmemcheck_enabled)
1893 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
1899 * This is the 'heart' of the zoned buddy allocator.
1902 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
1903 struct zonelist *zonelist, nodemask_t *nodemask)
1905 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1906 struct zone *preferred_zone;
1908 int migratetype = allocflags_to_migratetype(gfp_mask);
1910 gfp_mask &= gfp_allowed_mask;
1912 lockdep_trace_alloc(gfp_mask);
1914 might_sleep_if(gfp_mask & __GFP_WAIT);
1916 if (should_fail_alloc_page(gfp_mask, order))
1920 * Check the zones suitable for the gfp_mask contain at least one
1921 * valid zone. It's possible to have an empty zonelist as a result
1922 * of GFP_THISNODE and a memoryless node
1924 if (unlikely(!zonelist->_zonerefs->zone))
1927 /* The preferred zone is used for statistics later */
1928 first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
1929 if (!preferred_zone)
1932 /* First allocation attempt */
1933 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1934 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1935 preferred_zone, migratetype);
1936 if (unlikely(!page))
1937 page = __alloc_pages_slowpath(gfp_mask, order,
1938 zonelist, high_zoneidx, nodemask,
1939 preferred_zone, migratetype);
1941 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
1944 EXPORT_SYMBOL(__alloc_pages_nodemask);
1947 * Common helper functions.
1949 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
1954 * __get_free_pages() returns a 32-bit address, which cannot represent
1957 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
1959 page = alloc_pages(gfp_mask, order);
1962 return (unsigned long) page_address(page);
1964 EXPORT_SYMBOL(__get_free_pages);
1966 unsigned long get_zeroed_page(gfp_t gfp_mask)
1968 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
1970 EXPORT_SYMBOL(get_zeroed_page);
1972 void __pagevec_free(struct pagevec *pvec)
1974 int i = pagevec_count(pvec);
1977 trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
1978 free_hot_cold_page(pvec->pages[i], pvec->cold);
1982 void __free_pages(struct page *page, unsigned int order)
1984 if (put_page_testzero(page)) {
1985 trace_mm_page_free_direct(page, order);
1987 free_hot_page(page);
1989 __free_pages_ok(page, order);
1993 EXPORT_SYMBOL(__free_pages);
1995 void free_pages(unsigned long addr, unsigned int order)
1998 VM_BUG_ON(!virt_addr_valid((void *)addr));
1999 __free_pages(virt_to_page((void *)addr), order);
2003 EXPORT_SYMBOL(free_pages);
2006 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2007 * @size: the number of bytes to allocate
2008 * @gfp_mask: GFP flags for the allocation
2010 * This function is similar to alloc_pages(), except that it allocates the
2011 * minimum number of pages to satisfy the request. alloc_pages() can only
2012 * allocate memory in power-of-two pages.
2014 * This function is also limited by MAX_ORDER.
2016 * Memory allocated by this function must be released by free_pages_exact().
2018 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2020 unsigned int order = get_order(size);
2023 addr = __get_free_pages(gfp_mask, order);
2025 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2026 unsigned long used = addr + PAGE_ALIGN(size);
2028 split_page(virt_to_page((void *)addr), order);
2029 while (used < alloc_end) {
2035 return (void *)addr;
2037 EXPORT_SYMBOL(alloc_pages_exact);
2040 * free_pages_exact - release memory allocated via alloc_pages_exact()
2041 * @virt: the value returned by alloc_pages_exact.
2042 * @size: size of allocation, same value as passed to alloc_pages_exact().
2044 * Release the memory allocated by a previous call to alloc_pages_exact.
2046 void free_pages_exact(void *virt, size_t size)
2048 unsigned long addr = (unsigned long)virt;
2049 unsigned long end = addr + PAGE_ALIGN(size);
2051 while (addr < end) {
2056 EXPORT_SYMBOL(free_pages_exact);
2058 static unsigned int nr_free_zone_pages(int offset)
2063 /* Just pick one node, since fallback list is circular */
2064 unsigned int sum = 0;
2066 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2068 for_each_zone_zonelist(zone, z, zonelist, offset) {
2069 unsigned long size = zone->present_pages;
2070 unsigned long high = high_wmark_pages(zone);
2079 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2081 unsigned int nr_free_buffer_pages(void)
2083 return nr_free_zone_pages(gfp_zone(GFP_USER));
2085 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2088 * Amount of free RAM allocatable within all zones
2090 unsigned int nr_free_pagecache_pages(void)
2092 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2095 static inline void show_node(struct zone *zone)
2098 printk("Node %d ", zone_to_nid(zone));
2101 void si_meminfo(struct sysinfo *val)
2103 val->totalram = totalram_pages;
2105 val->freeram = global_page_state(NR_FREE_PAGES);
2106 val->bufferram = nr_blockdev_pages();
2107 val->totalhigh = totalhigh_pages;
2108 val->freehigh = nr_free_highpages();
2109 val->mem_unit = PAGE_SIZE;
2112 EXPORT_SYMBOL(si_meminfo);
2115 void si_meminfo_node(struct sysinfo *val, int nid)
2117 pg_data_t *pgdat = NODE_DATA(nid);
2119 val->totalram = pgdat->node_present_pages;
2120 val->freeram = node_page_state(nid, NR_FREE_PAGES);
2121 #ifdef CONFIG_HIGHMEM
2122 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2123 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2129 val->mem_unit = PAGE_SIZE;
2133 #define K(x) ((x) << (PAGE_SHIFT-10))
2136 * Show free area list (used inside shift_scroll-lock stuff)
2137 * We also calculate the percentage fragmentation. We do this by counting the
2138 * memory on each free list with the exception of the first item on the list.
2140 void show_free_areas(void)
2145 for_each_populated_zone(zone) {
2147 printk("%s per-cpu:\n", zone->name);
2149 for_each_online_cpu(cpu) {
2150 struct per_cpu_pageset *pageset;
2152 pageset = zone_pcp(zone, cpu);
2154 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2155 cpu, pageset->pcp.high,
2156 pageset->pcp.batch, pageset->pcp.count);
2160 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2161 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2163 " dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
2164 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2165 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2166 global_page_state(NR_ACTIVE_ANON),
2167 global_page_state(NR_INACTIVE_ANON),
2168 global_page_state(NR_ISOLATED_ANON),
2169 global_page_state(NR_ACTIVE_FILE),
2170 global_page_state(NR_INACTIVE_FILE),
2171 global_page_state(NR_ISOLATED_FILE),
2172 global_page_state(NR_UNEVICTABLE),
2173 global_page_state(NR_FILE_DIRTY),
2174 global_page_state(NR_WRITEBACK),
2175 global_page_state(NR_UNSTABLE_NFS),
2176 nr_blockdev_pages(),
2177 global_page_state(NR_FREE_PAGES),
2178 global_page_state(NR_SLAB_RECLAIMABLE),
2179 global_page_state(NR_SLAB_UNRECLAIMABLE),
2180 global_page_state(NR_FILE_MAPPED),
2181 global_page_state(NR_SHMEM),
2182 global_page_state(NR_PAGETABLE),
2183 global_page_state(NR_BOUNCE));
2185 for_each_populated_zone(zone) {
2194 " active_anon:%lukB"
2195 " inactive_anon:%lukB"
2196 " active_file:%lukB"
2197 " inactive_file:%lukB"
2198 " unevictable:%lukB"
2199 " isolated(anon):%lukB"
2200 " isolated(file):%lukB"
2207 " slab_reclaimable:%lukB"
2208 " slab_unreclaimable:%lukB"
2209 " kernel_stack:%lukB"
2213 " writeback_tmp:%lukB"
2214 " pages_scanned:%lu"
2215 " all_unreclaimable? %s"
2218 K(zone_page_state(zone, NR_FREE_PAGES)),
2219 K(min_wmark_pages(zone)),
2220 K(low_wmark_pages(zone)),
2221 K(high_wmark_pages(zone)),
2222 K(zone_page_state(zone, NR_ACTIVE_ANON)),
2223 K(zone_page_state(zone, NR_INACTIVE_ANON)),
2224 K(zone_page_state(zone, NR_ACTIVE_FILE)),
2225 K(zone_page_state(zone, NR_INACTIVE_FILE)),
2226 K(zone_page_state(zone, NR_UNEVICTABLE)),
2227 K(zone_page_state(zone, NR_ISOLATED_ANON)),
2228 K(zone_page_state(zone, NR_ISOLATED_FILE)),
2229 K(zone->present_pages),
2230 K(zone_page_state(zone, NR_MLOCK)),
2231 K(zone_page_state(zone, NR_FILE_DIRTY)),
2232 K(zone_page_state(zone, NR_WRITEBACK)),
2233 K(zone_page_state(zone, NR_FILE_MAPPED)),
2234 K(zone_page_state(zone, NR_SHMEM)),
2235 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
2236 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2237 zone_page_state(zone, NR_KERNEL_STACK) *
2239 K(zone_page_state(zone, NR_PAGETABLE)),
2240 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
2241 K(zone_page_state(zone, NR_BOUNCE)),
2242 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
2243 zone->pages_scanned,
2244 (zone_is_all_unreclaimable(zone) ? "yes" : "no")
2246 printk("lowmem_reserve[]:");
2247 for (i = 0; i < MAX_NR_ZONES; i++)
2248 printk(" %lu", zone->lowmem_reserve[i]);
2252 for_each_populated_zone(zone) {
2253 unsigned long nr[MAX_ORDER], flags, order, total = 0;
2256 printk("%s: ", zone->name);
2258 spin_lock_irqsave(&zone->lock, flags);
2259 for (order = 0; order < MAX_ORDER; order++) {
2260 nr[order] = zone->free_area[order].nr_free;
2261 total += nr[order] << order;
2263 spin_unlock_irqrestore(&zone->lock, flags);
2264 for (order = 0; order < MAX_ORDER; order++)
2265 printk("%lu*%lukB ", nr[order], K(1UL) << order);
2266 printk("= %lukB\n", K(total));
2269 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
2271 show_swap_cache_info();
2274 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
2276 zoneref->zone = zone;
2277 zoneref->zone_idx = zone_idx(zone);
2281 * Builds allocation fallback zone lists.
2283 * Add all populated zones of a node to the zonelist.
2285 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
2286 int nr_zones, enum zone_type zone_type)
2290 BUG_ON(zone_type >= MAX_NR_ZONES);
2295 zone = pgdat->node_zones + zone_type;
2296 if (populated_zone(zone)) {
2297 zoneref_set_zone(zone,
2298 &zonelist->_zonerefs[nr_zones++]);
2299 check_highest_zone(zone_type);
2302 } while (zone_type);
2309 * 0 = automatic detection of better ordering.
2310 * 1 = order by ([node] distance, -zonetype)
2311 * 2 = order by (-zonetype, [node] distance)
2313 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2314 * the same zonelist. So only NUMA can configure this param.
2316 #define ZONELIST_ORDER_DEFAULT 0
2317 #define ZONELIST_ORDER_NODE 1
2318 #define ZONELIST_ORDER_ZONE 2
2320 /* zonelist order in the kernel.
2321 * set_zonelist_order() will set this to NODE or ZONE.
2323 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
2324 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
2328 /* The value user specified ....changed by config */
2329 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2330 /* string for sysctl */
2331 #define NUMA_ZONELIST_ORDER_LEN 16
2332 char numa_zonelist_order[16] = "default";
2335 * interface for configure zonelist ordering.
2336 * command line option "numa_zonelist_order"
2337 * = "[dD]efault - default, automatic configuration.
2338 * = "[nN]ode - order by node locality, then by zone within node
2339 * = "[zZ]one - order by zone, then by locality within zone
2342 static int __parse_numa_zonelist_order(char *s)
2344 if (*s == 'd' || *s == 'D') {
2345 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2346 } else if (*s == 'n' || *s == 'N') {
2347 user_zonelist_order = ZONELIST_ORDER_NODE;
2348 } else if (*s == 'z' || *s == 'Z') {
2349 user_zonelist_order = ZONELIST_ORDER_ZONE;
2352 "Ignoring invalid numa_zonelist_order value: "
2359 static __init int setup_numa_zonelist_order(char *s)
2362 return __parse_numa_zonelist_order(s);
2365 early_param("numa_zonelist_order", setup_numa_zonelist_order);
2368 * sysctl handler for numa_zonelist_order
2370 int numa_zonelist_order_handler(ctl_table *table, int write,
2371 struct file *file, void __user *buffer, size_t *length,
2374 char saved_string[NUMA_ZONELIST_ORDER_LEN];
2378 strncpy(saved_string, (char*)table->data,
2379 NUMA_ZONELIST_ORDER_LEN);
2380 ret = proc_dostring(table, write, file, buffer, length, ppos);
2384 int oldval = user_zonelist_order;
2385 if (__parse_numa_zonelist_order((char*)table->data)) {
2387 * bogus value. restore saved string
2389 strncpy((char*)table->data, saved_string,
2390 NUMA_ZONELIST_ORDER_LEN);
2391 user_zonelist_order = oldval;
2392 } else if (oldval != user_zonelist_order)
2393 build_all_zonelists();
2399 #define MAX_NODE_LOAD (nr_online_nodes)
2400 static int node_load[MAX_NUMNODES];
2403 * find_next_best_node - find the next node that should appear in a given node's fallback list
2404 * @node: node whose fallback list we're appending
2405 * @used_node_mask: nodemask_t of already used nodes
2407 * We use a number of factors to determine which is the next node that should
2408 * appear on a given node's fallback list. The node should not have appeared
2409 * already in @node's fallback list, and it should be the next closest node
2410 * according to the distance array (which contains arbitrary distance values
2411 * from each node to each node in the system), and should also prefer nodes
2412 * with no CPUs, since presumably they'll have very little allocation pressure
2413 * on them otherwise.
2414 * It returns -1 if no node is found.
2416 static int find_next_best_node(int node, nodemask_t *used_node_mask)
2419 int min_val = INT_MAX;
2421 const struct cpumask *tmp = cpumask_of_node(0);
2423 /* Use the local node if we haven't already */
2424 if (!node_isset(node, *used_node_mask)) {
2425 node_set(node, *used_node_mask);
2429 for_each_node_state(n, N_HIGH_MEMORY) {
2431 /* Don't want a node to appear more than once */
2432 if (node_isset(n, *used_node_mask))
2435 /* Use the distance array to find the distance */
2436 val = node_distance(node, n);
2438 /* Penalize nodes under us ("prefer the next node") */
2441 /* Give preference to headless and unused nodes */
2442 tmp = cpumask_of_node(n);
2443 if (!cpumask_empty(tmp))
2444 val += PENALTY_FOR_NODE_WITH_CPUS;
2446 /* Slight preference for less loaded node */
2447 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2448 val += node_load[n];
2450 if (val < min_val) {
2457 node_set(best_node, *used_node_mask);
2464 * Build zonelists ordered by node and zones within node.
2465 * This results in maximum locality--normal zone overflows into local
2466 * DMA zone, if any--but risks exhausting DMA zone.
2468 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2471 struct zonelist *zonelist;
2473 zonelist = &pgdat->node_zonelists[0];
2474 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2476 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2478 zonelist->_zonerefs[j].zone = NULL;
2479 zonelist->_zonerefs[j].zone_idx = 0;
2483 * Build gfp_thisnode zonelists
2485 static void build_thisnode_zonelists(pg_data_t *pgdat)
2488 struct zonelist *zonelist;
2490 zonelist = &pgdat->node_zonelists[1];
2491 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2492 zonelist->_zonerefs[j].zone = NULL;
2493 zonelist->_zonerefs[j].zone_idx = 0;
2497 * Build zonelists ordered by zone and nodes within zones.
2498 * This results in conserving DMA zone[s] until all Normal memory is
2499 * exhausted, but results in overflowing to remote node while memory
2500 * may still exist in local DMA zone.
2502 static int node_order[MAX_NUMNODES];
2504 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2507 int zone_type; /* needs to be signed */
2509 struct zonelist *zonelist;
2511 zonelist = &pgdat->node_zonelists[0];
2513 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
2514 for (j = 0; j < nr_nodes; j++) {
2515 node = node_order[j];
2516 z = &NODE_DATA(node)->node_zones[zone_type];
2517 if (populated_zone(z)) {
2519 &zonelist->_zonerefs[pos++]);
2520 check_highest_zone(zone_type);
2524 zonelist->_zonerefs[pos].zone = NULL;
2525 zonelist->_zonerefs[pos].zone_idx = 0;
2528 static int default_zonelist_order(void)
2531 unsigned long low_kmem_size,total_size;
2535 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2536 * If they are really small and used heavily, the system can fall
2537 * into OOM very easily.
2538 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2540 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2543 for_each_online_node(nid) {
2544 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2545 z = &NODE_DATA(nid)->node_zones[zone_type];
2546 if (populated_zone(z)) {
2547 if (zone_type < ZONE_NORMAL)
2548 low_kmem_size += z->present_pages;
2549 total_size += z->present_pages;
2553 if (!low_kmem_size || /* there are no DMA area. */
2554 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
2555 return ZONELIST_ORDER_NODE;
2557 * look into each node's config.
2558 * If there is a node whose DMA/DMA32 memory is very big area on
2559 * local memory, NODE_ORDER may be suitable.
2561 average_size = total_size /
2562 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2563 for_each_online_node(nid) {
2566 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2567 z = &NODE_DATA(nid)->node_zones[zone_type];
2568 if (populated_zone(z)) {
2569 if (zone_type < ZONE_NORMAL)
2570 low_kmem_size += z->present_pages;
2571 total_size += z->present_pages;
2574 if (low_kmem_size &&
2575 total_size > average_size && /* ignore small node */
2576 low_kmem_size > total_size * 70/100)
2577 return ZONELIST_ORDER_NODE;
2579 return ZONELIST_ORDER_ZONE;
2582 static void set_zonelist_order(void)
2584 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
2585 current_zonelist_order = default_zonelist_order();
2587 current_zonelist_order = user_zonelist_order;
2590 static void build_zonelists(pg_data_t *pgdat)
2594 nodemask_t used_mask;
2595 int local_node, prev_node;
2596 struct zonelist *zonelist;
2597 int order = current_zonelist_order;
2599 /* initialize zonelists */
2600 for (i = 0; i < MAX_ZONELISTS; i++) {
2601 zonelist = pgdat->node_zonelists + i;
2602 zonelist->_zonerefs[0].zone = NULL;
2603 zonelist->_zonerefs[0].zone_idx = 0;
2606 /* NUMA-aware ordering of nodes */
2607 local_node = pgdat->node_id;
2608 load = nr_online_nodes;
2609 prev_node = local_node;
2610 nodes_clear(used_mask);
2612 memset(node_order, 0, sizeof(node_order));
2615 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2616 int distance = node_distance(local_node, node);
2619 * If another node is sufficiently far away then it is better
2620 * to reclaim pages in a zone before going off node.
2622 if (distance > RECLAIM_DISTANCE)
2623 zone_reclaim_mode = 1;
2626 * We don't want to pressure a particular node.
2627 * So adding penalty to the first node in same
2628 * distance group to make it round-robin.
2630 if (distance != node_distance(local_node, prev_node))
2631 node_load[node] = load;
2635 if (order == ZONELIST_ORDER_NODE)
2636 build_zonelists_in_node_order(pgdat, node);
2638 node_order[j++] = node; /* remember order */
2641 if (order == ZONELIST_ORDER_ZONE) {
2642 /* calculate node order -- i.e., DMA last! */
2643 build_zonelists_in_zone_order(pgdat, j);
2646 build_thisnode_zonelists(pgdat);
2649 /* Construct the zonelist performance cache - see further mmzone.h */
2650 static void build_zonelist_cache(pg_data_t *pgdat)
2652 struct zonelist *zonelist;
2653 struct zonelist_cache *zlc;
2656 zonelist = &pgdat->node_zonelists[0];
2657 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
2658 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2659 for (z = zonelist->_zonerefs; z->zone; z++)
2660 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2664 #else /* CONFIG_NUMA */
2666 static void set_zonelist_order(void)
2668 current_zonelist_order = ZONELIST_ORDER_ZONE;
2671 static void build_zonelists(pg_data_t *pgdat)
2673 int node, local_node;
2675 struct zonelist *zonelist;
2677 local_node = pgdat->node_id;
2679 zonelist = &pgdat->node_zonelists[0];
2680 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2683 * Now we build the zonelist so that it contains the zones
2684 * of all the other nodes.
2685 * We don't want to pressure a particular node, so when
2686 * building the zones for node N, we make sure that the
2687 * zones coming right after the local ones are those from
2688 * node N+1 (modulo N)
2690 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
2691 if (!node_online(node))
2693 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2696 for (node = 0; node < local_node; node++) {
2697 if (!node_online(node))
2699 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2703 zonelist->_zonerefs[j].zone = NULL;
2704 zonelist->_zonerefs[j].zone_idx = 0;
2707 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2708 static void build_zonelist_cache(pg_data_t *pgdat)
2710 pgdat->node_zonelists[0].zlcache_ptr = NULL;
2713 #endif /* CONFIG_NUMA */
2715 /* return values int ....just for stop_machine() */
2716 static int __build_all_zonelists(void *dummy)
2721 memset(node_load, 0, sizeof(node_load));
2723 for_each_online_node(nid) {
2724 pg_data_t *pgdat = NODE_DATA(nid);
2726 build_zonelists(pgdat);
2727 build_zonelist_cache(pgdat);
2732 void build_all_zonelists(void)
2734 set_zonelist_order();
2736 if (system_state == SYSTEM_BOOTING) {
2737 __build_all_zonelists(NULL);
2738 mminit_verify_zonelist();
2739 cpuset_init_current_mems_allowed();
2741 /* we have to stop all cpus to guarantee there is no user
2743 stop_machine(__build_all_zonelists, NULL, NULL);
2744 /* cpuset refresh routine should be here */
2746 vm_total_pages = nr_free_pagecache_pages();
2748 * Disable grouping by mobility if the number of pages in the
2749 * system is too low to allow the mechanism to work. It would be
2750 * more accurate, but expensive to check per-zone. This check is
2751 * made on memory-hotadd so a system can start with mobility
2752 * disabled and enable it later
2754 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2755 page_group_by_mobility_disabled = 1;
2757 page_group_by_mobility_disabled = 0;
2759 printk("Built %i zonelists in %s order, mobility grouping %s. "
2760 "Total pages: %ld\n",
2762 zonelist_order_name[current_zonelist_order],
2763 page_group_by_mobility_disabled ? "off" : "on",
2766 printk("Policy zone: %s\n", zone_names[policy_zone]);
2771 * Helper functions to size the waitqueue hash table.
2772 * Essentially these want to choose hash table sizes sufficiently
2773 * large so that collisions trying to wait on pages are rare.
2774 * But in fact, the number of active page waitqueues on typical
2775 * systems is ridiculously low, less than 200. So this is even
2776 * conservative, even though it seems large.
2778 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2779 * waitqueues, i.e. the size of the waitq table given the number of pages.
2781 #define PAGES_PER_WAITQUEUE 256
2783 #ifndef CONFIG_MEMORY_HOTPLUG
2784 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2786 unsigned long size = 1;
2788 pages /= PAGES_PER_WAITQUEUE;
2790 while (size < pages)
2794 * Once we have dozens or even hundreds of threads sleeping
2795 * on IO we've got bigger problems than wait queue collision.
2796 * Limit the size of the wait table to a reasonable size.
2798 size = min(size, 4096UL);
2800 return max(size, 4UL);
2804 * A zone's size might be changed by hot-add, so it is not possible to determine
2805 * a suitable size for its wait_table. So we use the maximum size now.
2807 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2809 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2810 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2811 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2813 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2814 * or more by the traditional way. (See above). It equals:
2816 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2817 * ia64(16K page size) : = ( 8G + 4M)byte.
2818 * powerpc (64K page size) : = (32G +16M)byte.
2820 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2827 * This is an integer logarithm so that shifts can be used later
2828 * to extract the more random high bits from the multiplicative
2829 * hash function before the remainder is taken.
2831 static inline unsigned long wait_table_bits(unsigned long size)
2836 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2839 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2840 * of blocks reserved is based on min_wmark_pages(zone). The memory within
2841 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
2842 * higher will lead to a bigger reserve which will get freed as contiguous
2843 * blocks as reclaim kicks in
2845 static void setup_zone_migrate_reserve(struct zone *zone)
2847 unsigned long start_pfn, pfn, end_pfn;
2849 unsigned long block_migratetype;
2852 /* Get the start pfn, end pfn and the number of blocks to reserve */
2853 start_pfn = zone->zone_start_pfn;
2854 end_pfn = start_pfn + zone->spanned_pages;
2855 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2859 * Reserve blocks are generally in place to help high-order atomic
2860 * allocations that are short-lived. A min_free_kbytes value that
2861 * would result in more than 2 reserve blocks for atomic allocations
2862 * is assumed to be in place to help anti-fragmentation for the
2863 * future allocation of hugepages at runtime.
2865 reserve = min(2, reserve);
2867 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2868 if (!pfn_valid(pfn))
2870 page = pfn_to_page(pfn);
2872 /* Watch out for overlapping nodes */
2873 if (page_to_nid(page) != zone_to_nid(zone))
2876 /* Blocks with reserved pages will never free, skip them. */
2877 if (PageReserved(page))
2880 block_migratetype = get_pageblock_migratetype(page);
2882 /* If this block is reserved, account for it */
2883 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
2888 /* Suitable for reserving if this block is movable */
2889 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
2890 set_pageblock_migratetype(page, MIGRATE_RESERVE);
2891 move_freepages_block(zone, page, MIGRATE_RESERVE);
2897 * If the reserve is met and this is a previous reserved block,
2900 if (block_migratetype == MIGRATE_RESERVE) {
2901 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2902 move_freepages_block(zone, page, MIGRATE_MOVABLE);
2908 * Initially all pages are reserved - free ones are freed
2909 * up by free_all_bootmem() once the early boot process is
2910 * done. Non-atomic initialization, single-pass.
2912 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
2913 unsigned long start_pfn, enum memmap_context context)
2916 unsigned long end_pfn = start_pfn + size;
2920 if (highest_memmap_pfn < end_pfn - 1)
2921 highest_memmap_pfn = end_pfn - 1;
2923 z = &NODE_DATA(nid)->node_zones[zone];
2924 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
2926 * There can be holes in boot-time mem_map[]s
2927 * handed to this function. They do not
2928 * exist on hotplugged memory.
2930 if (context == MEMMAP_EARLY) {
2931 if (!early_pfn_valid(pfn))
2933 if (!early_pfn_in_nid(pfn, nid))
2936 page = pfn_to_page(pfn);
2937 set_page_links(page, zone, nid, pfn);
2938 mminit_verify_page_links(page, zone, nid, pfn);
2939 init_page_count(page);
2940 reset_page_mapcount(page);
2941 SetPageReserved(page);
2943 * Mark the block movable so that blocks are reserved for
2944 * movable at startup. This will force kernel allocations
2945 * to reserve their blocks rather than leaking throughout
2946 * the address space during boot when many long-lived
2947 * kernel allocations are made. Later some blocks near
2948 * the start are marked MIGRATE_RESERVE by
2949 * setup_zone_migrate_reserve()
2951 * bitmap is created for zone's valid pfn range. but memmap
2952 * can be created for invalid pages (for alignment)
2953 * check here not to call set_pageblock_migratetype() against
2956 if ((z->zone_start_pfn <= pfn)
2957 && (pfn < z->zone_start_pfn + z->spanned_pages)
2958 && !(pfn & (pageblock_nr_pages - 1)))
2959 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2961 INIT_LIST_HEAD(&page->lru);
2962 #ifdef WANT_PAGE_VIRTUAL
2963 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2964 if (!is_highmem_idx(zone))
2965 set_page_address(page, __va(pfn << PAGE_SHIFT));
2970 static void __meminit zone_init_free_lists(struct zone *zone)
2973 for_each_migratetype_order(order, t) {
2974 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
2975 zone->free_area[order].nr_free = 0;
2979 #ifndef __HAVE_ARCH_MEMMAP_INIT
2980 #define memmap_init(size, nid, zone, start_pfn) \
2981 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2984 static int zone_batchsize(struct zone *zone)
2990 * The per-cpu-pages pools are set to around 1000th of the
2991 * size of the zone. But no more than 1/2 of a meg.
2993 * OK, so we don't know how big the cache is. So guess.
2995 batch = zone->present_pages / 1024;
2996 if (batch * PAGE_SIZE > 512 * 1024)
2997 batch = (512 * 1024) / PAGE_SIZE;
2998 batch /= 4; /* We effectively *= 4 below */
3003 * Clamp the batch to a 2^n - 1 value. Having a power
3004 * of 2 value was found to be more likely to have
3005 * suboptimal cache aliasing properties in some cases.
3007 * For example if 2 tasks are alternately allocating
3008 * batches of pages, one task can end up with a lot
3009 * of pages of one half of the possible page colors
3010 * and the other with pages of the other colors.
3012 batch = rounddown_pow_of_two(batch + batch/2) - 1;
3017 /* The deferral and batching of frees should be suppressed under NOMMU
3020 * The problem is that NOMMU needs to be able to allocate large chunks
3021 * of contiguous memory as there's no hardware page translation to
3022 * assemble apparent contiguous memory from discontiguous pages.
3024 * Queueing large contiguous runs of pages for batching, however,
3025 * causes the pages to actually be freed in smaller chunks. As there
3026 * can be a significant delay between the individual batches being
3027 * recycled, this leads to the once large chunks of space being
3028 * fragmented and becoming unavailable for high-order allocations.
3034 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3036 struct per_cpu_pages *pcp;
3039 memset(p, 0, sizeof(*p));
3043 pcp->high = 6 * batch;
3044 pcp->batch = max(1UL, 1 * batch);
3045 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
3046 INIT_LIST_HEAD(&pcp->lists[migratetype]);
3050 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3051 * to the value high for the pageset p.
3054 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
3057 struct per_cpu_pages *pcp;
3061 pcp->batch = max(1UL, high/4);
3062 if ((high/4) > (PAGE_SHIFT * 8))
3063 pcp->batch = PAGE_SHIFT * 8;
3069 * Boot pageset table. One per cpu which is going to be used for all
3070 * zones and all nodes. The parameters will be set in such a way
3071 * that an item put on a list will immediately be handed over to
3072 * the buddy list. This is safe since pageset manipulation is done
3073 * with interrupts disabled.
3075 * Some NUMA counter updates may also be caught by the boot pagesets.
3077 * The boot_pagesets must be kept even after bootup is complete for
3078 * unused processors and/or zones. They do play a role for bootstrapping
3079 * hotplugged processors.
3081 * zoneinfo_show() and maybe other functions do
3082 * not check if the processor is online before following the pageset pointer.
3083 * Other parts of the kernel may not check if the zone is available.
3085 static struct per_cpu_pageset boot_pageset[NR_CPUS];
3088 * Dynamically allocate memory for the
3089 * per cpu pageset array in struct zone.
3091 static int __cpuinit process_zones(int cpu)
3093 struct zone *zone, *dzone;
3094 int node = cpu_to_node(cpu);
3096 node_set_state(node, N_CPU); /* this node has a cpu */
3098 for_each_populated_zone(zone) {
3099 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
3101 if (!zone_pcp(zone, cpu))
3104 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
3106 if (percpu_pagelist_fraction)
3107 setup_pagelist_highmark(zone_pcp(zone, cpu),
3108 (zone->present_pages / percpu_pagelist_fraction));
3113 for_each_zone(dzone) {
3114 if (!populated_zone(dzone))
3118 kfree(zone_pcp(dzone, cpu));
3119 zone_pcp(dzone, cpu) = &boot_pageset[cpu];
3124 static inline void free_zone_pagesets(int cpu)
3128 for_each_zone(zone) {
3129 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
3131 /* Free per_cpu_pageset if it is slab allocated */
3132 if (pset != &boot_pageset[cpu])
3134 zone_pcp(zone, cpu) = &boot_pageset[cpu];
3138 static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3139 unsigned long action,
3142 int cpu = (long)hcpu;
3143 int ret = NOTIFY_OK;
3146 case CPU_UP_PREPARE:
3147 case CPU_UP_PREPARE_FROZEN:
3148 if (process_zones(cpu))
3151 case CPU_UP_CANCELED:
3152 case CPU_UP_CANCELED_FROZEN:
3154 case CPU_DEAD_FROZEN:
3155 free_zone_pagesets(cpu);
3163 static struct notifier_block __cpuinitdata pageset_notifier =
3164 { &pageset_cpuup_callback, NULL, 0 };
3166 void __init setup_per_cpu_pageset(void)
3170 /* Initialize per_cpu_pageset for cpu 0.
3171 * A cpuup callback will do this for every cpu
3172 * as it comes online
3174 err = process_zones(smp_processor_id());
3176 register_cpu_notifier(&pageset_notifier);
3181 static noinline __init_refok
3182 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3185 struct pglist_data *pgdat = zone->zone_pgdat;
3189 * The per-page waitqueue mechanism uses hashed waitqueues
3192 zone->wait_table_hash_nr_entries =
3193 wait_table_hash_nr_entries(zone_size_pages);
3194 zone->wait_table_bits =
3195 wait_table_bits(zone->wait_table_hash_nr_entries);
3196 alloc_size = zone->wait_table_hash_nr_entries
3197 * sizeof(wait_queue_head_t);
3199 if (!slab_is_available()) {
3200 zone->wait_table = (wait_queue_head_t *)
3201 alloc_bootmem_node(pgdat, alloc_size);
3204 * This case means that a zone whose size was 0 gets new memory
3205 * via memory hot-add.
3206 * But it may be the case that a new node was hot-added. In
3207 * this case vmalloc() will not be able to use this new node's
3208 * memory - this wait_table must be initialized to use this new
3209 * node itself as well.
3210 * To use this new node's memory, further consideration will be
3213 zone->wait_table = vmalloc(alloc_size);
3215 if (!zone->wait_table)
3218 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3219 init_waitqueue_head(zone->wait_table + i);
3224 static int __zone_pcp_update(void *data)
3226 struct zone *zone = data;
3228 unsigned long batch = zone_batchsize(zone), flags;
3230 for (cpu = 0; cpu < NR_CPUS; cpu++) {
3231 struct per_cpu_pageset *pset;
3232 struct per_cpu_pages *pcp;
3234 pset = zone_pcp(zone, cpu);
3237 local_irq_save(flags);
3238 free_pcppages_bulk(zone, pcp->count, pcp);
3239 setup_pageset(pset, batch);
3240 local_irq_restore(flags);
3245 void zone_pcp_update(struct zone *zone)
3247 stop_machine(__zone_pcp_update, zone, NULL);
3250 static __meminit void zone_pcp_init(struct zone *zone)
3253 unsigned long batch = zone_batchsize(zone);
3255 for (cpu = 0; cpu < NR_CPUS; cpu++) {
3257 /* Early boot. Slab allocator not functional yet */
3258 zone_pcp(zone, cpu) = &boot_pageset[cpu];
3259 setup_pageset(&boot_pageset[cpu],0);
3261 setup_pageset(zone_pcp(zone,cpu), batch);
3264 if (zone->present_pages)
3265 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
3266 zone->name, zone->present_pages, batch);
3269 __meminit int init_currently_empty_zone(struct zone *zone,
3270 unsigned long zone_start_pfn,
3272 enum memmap_context context)
3274 struct pglist_data *pgdat = zone->zone_pgdat;
3276 ret = zone_wait_table_init(zone, size);
3279 pgdat->nr_zones = zone_idx(zone) + 1;
3281 zone->zone_start_pfn = zone_start_pfn;
3283 mminit_dprintk(MMINIT_TRACE, "memmap_init",
3284 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3286 (unsigned long)zone_idx(zone),
3287 zone_start_pfn, (zone_start_pfn + size));
3289 zone_init_free_lists(zone);
3294 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3296 * Basic iterator support. Return the first range of PFNs for a node
3297 * Note: nid == MAX_NUMNODES returns first region regardless of node
3299 static int __meminit first_active_region_index_in_nid(int nid)
3303 for (i = 0; i < nr_nodemap_entries; i++)
3304 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3311 * Basic iterator support. Return the next active range of PFNs for a node
3312 * Note: nid == MAX_NUMNODES returns next region regardless of node
3314 static int __meminit next_active_region_index_in_nid(int index, int nid)
3316 for (index = index + 1; index < nr_nodemap_entries; index++)
3317 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3323 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3325 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3326 * Architectures may implement their own version but if add_active_range()
3327 * was used and there are no special requirements, this is a convenient
3330 int __meminit __early_pfn_to_nid(unsigned long pfn)
3334 for (i = 0; i < nr_nodemap_entries; i++) {
3335 unsigned long start_pfn = early_node_map[i].start_pfn;
3336 unsigned long end_pfn = early_node_map[i].end_pfn;
3338 if (start_pfn <= pfn && pfn < end_pfn)
3339 return early_node_map[i].nid;
3341 /* This is a memory hole */
3344 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3346 int __meminit early_pfn_to_nid(unsigned long pfn)
3350 nid = __early_pfn_to_nid(pfn);
3353 /* just returns 0 */
3357 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3358 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
3362 nid = __early_pfn_to_nid(pfn);
3363 if (nid >= 0 && nid != node)
3369 /* Basic iterator support to walk early_node_map[] */
3370 #define for_each_active_range_index_in_nid(i, nid) \
3371 for (i = first_active_region_index_in_nid(nid); i != -1; \
3372 i = next_active_region_index_in_nid(i, nid))
3375 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3376 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3377 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3379 * If an architecture guarantees that all ranges registered with
3380 * add_active_ranges() contain no holes and may be freed, this
3381 * this function may be used instead of calling free_bootmem() manually.
3383 void __init free_bootmem_with_active_regions(int nid,
3384 unsigned long max_low_pfn)
3388 for_each_active_range_index_in_nid(i, nid) {
3389 unsigned long size_pages = 0;
3390 unsigned long end_pfn = early_node_map[i].end_pfn;
3392 if (early_node_map[i].start_pfn >= max_low_pfn)
3395 if (end_pfn > max_low_pfn)
3396 end_pfn = max_low_pfn;
3398 size_pages = end_pfn - early_node_map[i].start_pfn;
3399 free_bootmem_node(NODE_DATA(early_node_map[i].nid),
3400 PFN_PHYS(early_node_map[i].start_pfn),
3401 size_pages << PAGE_SHIFT);
3405 void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
3410 for_each_active_range_index_in_nid(i, nid) {
3411 ret = work_fn(early_node_map[i].start_pfn,
3412 early_node_map[i].end_pfn, data);
3418 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3419 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3421 * If an architecture guarantees that all ranges registered with
3422 * add_active_ranges() contain no holes and may be freed, this
3423 * function may be used instead of calling memory_present() manually.
3425 void __init sparse_memory_present_with_active_regions(int nid)
3429 for_each_active_range_index_in_nid(i, nid)
3430 memory_present(early_node_map[i].nid,
3431 early_node_map[i].start_pfn,
3432 early_node_map[i].end_pfn);
3436 * get_pfn_range_for_nid - Return the start and end page frames for a node
3437 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3438 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3439 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3441 * It returns the start and end page frame of a node based on information
3442 * provided by an arch calling add_active_range(). If called for a node
3443 * with no available memory, a warning is printed and the start and end
3446 void __meminit get_pfn_range_for_nid(unsigned int nid,
3447 unsigned long *start_pfn, unsigned long *end_pfn)
3453 for_each_active_range_index_in_nid(i, nid) {
3454 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
3455 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
3458 if (*start_pfn == -1UL)
3463 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3464 * assumption is made that zones within a node are ordered in monotonic
3465 * increasing memory addresses so that the "highest" populated zone is used
3467 static void __init find_usable_zone_for_movable(void)
3470 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
3471 if (zone_index == ZONE_MOVABLE)
3474 if (arch_zone_highest_possible_pfn[zone_index] >
3475 arch_zone_lowest_possible_pfn[zone_index])
3479 VM_BUG_ON(zone_index == -1);
3480 movable_zone = zone_index;
3484 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3485 * because it is sized independant of architecture. Unlike the other zones,
3486 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3487 * in each node depending on the size of each node and how evenly kernelcore
3488 * is distributed. This helper function adjusts the zone ranges
3489 * provided by the architecture for a given node by using the end of the
3490 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3491 * zones within a node are in order of monotonic increases memory addresses
3493 static void __meminit adjust_zone_range_for_zone_movable(int nid,
3494 unsigned long zone_type,
3495 unsigned long node_start_pfn,
3496 unsigned long node_end_pfn,
3497 unsigned long *zone_start_pfn,
3498 unsigned long *zone_end_pfn)
3500 /* Only adjust if ZONE_MOVABLE is on this node */
3501 if (zone_movable_pfn[nid]) {
3502 /* Size ZONE_MOVABLE */
3503 if (zone_type == ZONE_MOVABLE) {
3504 *zone_start_pfn = zone_movable_pfn[nid];
3505 *zone_end_pfn = min(node_end_pfn,
3506 arch_zone_highest_possible_pfn[movable_zone]);
3508 /* Adjust for ZONE_MOVABLE starting within this range */
3509 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
3510 *zone_end_pfn > zone_movable_pfn[nid]) {
3511 *zone_end_pfn = zone_movable_pfn[nid];
3513 /* Check if this whole range is within ZONE_MOVABLE */
3514 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
3515 *zone_start_pfn = *zone_end_pfn;
3520 * Return the number of pages a zone spans in a node, including holes
3521 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3523 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3524 unsigned long zone_type,
3525 unsigned long *ignored)
3527 unsigned long node_start_pfn, node_end_pfn;
3528 unsigned long zone_start_pfn, zone_end_pfn;
3530 /* Get the start and end of the node and zone */
3531 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3532 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
3533 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
3534 adjust_zone_range_for_zone_movable(nid, zone_type,
3535 node_start_pfn, node_end_pfn,
3536 &zone_start_pfn, &zone_end_pfn);
3538 /* Check that this node has pages within the zone's required range */
3539 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
3542 /* Move the zone boundaries inside the node if necessary */
3543 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
3544 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
3546 /* Return the spanned pages */
3547 return zone_end_pfn - zone_start_pfn;
3551 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3552 * then all holes in the requested range will be accounted for.
3554 static unsigned long __meminit __absent_pages_in_range(int nid,
3555 unsigned long range_start_pfn,
3556 unsigned long range_end_pfn)
3559 unsigned long prev_end_pfn = 0, hole_pages = 0;
3560 unsigned long start_pfn;
3562 /* Find the end_pfn of the first active range of pfns in the node */
3563 i = first_active_region_index_in_nid(nid);
3567 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3569 /* Account for ranges before physical memory on this node */
3570 if (early_node_map[i].start_pfn > range_start_pfn)
3571 hole_pages = prev_end_pfn - range_start_pfn;
3573 /* Find all holes for the zone within the node */
3574 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
3576 /* No need to continue if prev_end_pfn is outside the zone */
3577 if (prev_end_pfn >= range_end_pfn)
3580 /* Make sure the end of the zone is not within the hole */
3581 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3582 prev_end_pfn = max(prev_end_pfn, range_start_pfn);
3584 /* Update the hole size cound and move on */
3585 if (start_pfn > range_start_pfn) {
3586 BUG_ON(prev_end_pfn > start_pfn);
3587 hole_pages += start_pfn - prev_end_pfn;
3589 prev_end_pfn = early_node_map[i].end_pfn;
3592 /* Account for ranges past physical memory on this node */
3593 if (range_end_pfn > prev_end_pfn)
3594 hole_pages += range_end_pfn -
3595 max(range_start_pfn, prev_end_pfn);
3601 * absent_pages_in_range - Return number of page frames in holes within a range
3602 * @start_pfn: The start PFN to start searching for holes
3603 * @end_pfn: The end PFN to stop searching for holes
3605 * It returns the number of pages frames in memory holes within a range.
3607 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
3608 unsigned long end_pfn)
3610 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
3613 /* Return the number of page frames in holes in a zone on a node */
3614 static unsigned long __meminit zone_absent_pages_in_node(int nid,
3615 unsigned long zone_type,
3616 unsigned long *ignored)
3618 unsigned long node_start_pfn, node_end_pfn;
3619 unsigned long zone_start_pfn, zone_end_pfn;
3621 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3622 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
3624 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
3627 adjust_zone_range_for_zone_movable(nid, zone_type,
3628 node_start_pfn, node_end_pfn,
3629 &zone_start_pfn, &zone_end_pfn);
3630 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3634 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3635 unsigned long zone_type,
3636 unsigned long *zones_size)
3638 return zones_size[zone_type];
3641 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3642 unsigned long zone_type,
3643 unsigned long *zholes_size)
3648 return zholes_size[zone_type];
3653 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3654 unsigned long *zones_size, unsigned long *zholes_size)
3656 unsigned long realtotalpages, totalpages = 0;
3659 for (i = 0; i < MAX_NR_ZONES; i++)
3660 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
3662 pgdat->node_spanned_pages = totalpages;
3664 realtotalpages = totalpages;
3665 for (i = 0; i < MAX_NR_ZONES; i++)
3667 zone_absent_pages_in_node(pgdat->node_id, i,
3669 pgdat->node_present_pages = realtotalpages;
3670 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
3674 #ifndef CONFIG_SPARSEMEM
3676 * Calculate the size of the zone->blockflags rounded to an unsigned long
3677 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3678 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3679 * round what is now in bits to nearest long in bits, then return it in
3682 static unsigned long __init usemap_size(unsigned long zonesize)
3684 unsigned long usemapsize;
3686 usemapsize = roundup(zonesize, pageblock_nr_pages);
3687 usemapsize = usemapsize >> pageblock_order;
3688 usemapsize *= NR_PAGEBLOCK_BITS;
3689 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
3691 return usemapsize / 8;
3694 static void __init setup_usemap(struct pglist_data *pgdat,
3695 struct zone *zone, unsigned long zonesize)
3697 unsigned long usemapsize = usemap_size(zonesize);
3698 zone->pageblock_flags = NULL;
3700 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
3703 static void inline setup_usemap(struct pglist_data *pgdat,
3704 struct zone *zone, unsigned long zonesize) {}
3705 #endif /* CONFIG_SPARSEMEM */
3707 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3709 /* Return a sensible default order for the pageblock size. */
3710 static inline int pageblock_default_order(void)
3712 if (HPAGE_SHIFT > PAGE_SHIFT)
3713 return HUGETLB_PAGE_ORDER;
3718 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3719 static inline void __init set_pageblock_order(unsigned int order)
3721 /* Check that pageblock_nr_pages has not already been setup */
3722 if (pageblock_order)
3726 * Assume the largest contiguous order of interest is a huge page.
3727 * This value may be variable depending on boot parameters on IA64
3729 pageblock_order = order;
3731 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3734 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3735 * and pageblock_default_order() are unused as pageblock_order is set
3736 * at compile-time. See include/linux/pageblock-flags.h for the values of
3737 * pageblock_order based on the kernel config
3739 static inline int pageblock_default_order(unsigned int order)
3743 #define set_pageblock_order(x) do {} while (0)
3745 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3748 * Set up the zone data structures:
3749 * - mark all pages reserved
3750 * - mark all memory queues empty
3751 * - clear the memory bitmaps
3753 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
3754 unsigned long *zones_size, unsigned long *zholes_size)
3757 int nid = pgdat->node_id;
3758 unsigned long zone_start_pfn = pgdat->node_start_pfn;
3761 pgdat_resize_init(pgdat);
3762 pgdat->nr_zones = 0;
3763 init_waitqueue_head(&pgdat->kswapd_wait);
3764 pgdat->kswapd_max_order = 0;
3765 pgdat_page_cgroup_init(pgdat);
3767 for (j = 0; j < MAX_NR_ZONES; j++) {
3768 struct zone *zone = pgdat->node_zones + j;
3769 unsigned long size, realsize, memmap_pages;
3772 size = zone_spanned_pages_in_node(nid, j, zones_size);
3773 realsize = size - zone_absent_pages_in_node(nid, j,
3777 * Adjust realsize so that it accounts for how much memory
3778 * is used by this zone for memmap. This affects the watermark
3779 * and per-cpu initialisations
3782 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3783 if (realsize >= memmap_pages) {
3784 realsize -= memmap_pages;
3787 " %s zone: %lu pages used for memmap\n",
3788 zone_names[j], memmap_pages);
3791 " %s zone: %lu pages exceeds realsize %lu\n",
3792 zone_names[j], memmap_pages, realsize);
3794 /* Account for reserved pages */
3795 if (j == 0 && realsize > dma_reserve) {
3796 realsize -= dma_reserve;
3797 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
3798 zone_names[0], dma_reserve);
3801 if (!is_highmem_idx(j))
3802 nr_kernel_pages += realsize;
3803 nr_all_pages += realsize;
3805 zone->spanned_pages = size;
3806 zone->present_pages = realsize;
3809 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3811 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3813 zone->name = zone_names[j];
3814 spin_lock_init(&zone->lock);
3815 spin_lock_init(&zone->lru_lock);
3816 zone_seqlock_init(zone);
3817 zone->zone_pgdat = pgdat;
3819 zone->prev_priority = DEF_PRIORITY;
3821 zone_pcp_init(zone);
3823 INIT_LIST_HEAD(&zone->lru[l].list);
3824 zone->reclaim_stat.nr_saved_scan[l] = 0;
3826 zone->reclaim_stat.recent_rotated[0] = 0;
3827 zone->reclaim_stat.recent_rotated[1] = 0;
3828 zone->reclaim_stat.recent_scanned[0] = 0;
3829 zone->reclaim_stat.recent_scanned[1] = 0;
3830 zap_zone_vm_stats(zone);
3835 set_pageblock_order(pageblock_default_order());
3836 setup_usemap(pgdat, zone, size);
3837 ret = init_currently_empty_zone(zone, zone_start_pfn,
3838 size, MEMMAP_EARLY);
3840 memmap_init(size, nid, j, zone_start_pfn);
3841 zone_start_pfn += size;
3845 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
3847 /* Skip empty nodes */
3848 if (!pgdat->node_spanned_pages)
3851 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3852 /* ia64 gets its own node_mem_map, before this, without bootmem */
3853 if (!pgdat->node_mem_map) {
3854 unsigned long size, start, end;
3858 * The zone's endpoints aren't required to be MAX_ORDER
3859 * aligned but the node_mem_map endpoints must be in order
3860 * for the buddy allocator to function correctly.
3862 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
3863 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
3864 end = ALIGN(end, MAX_ORDER_NR_PAGES);
3865 size = (end - start) * sizeof(struct page);
3866 map = alloc_remap(pgdat->node_id, size);
3868 map = alloc_bootmem_node(pgdat, size);
3869 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
3871 #ifndef CONFIG_NEED_MULTIPLE_NODES
3873 * With no DISCONTIG, the global mem_map is just set as node 0's
3875 if (pgdat == NODE_DATA(0)) {
3876 mem_map = NODE_DATA(0)->node_mem_map;
3877 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3878 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3879 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3880 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3883 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3886 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
3887 unsigned long node_start_pfn, unsigned long *zholes_size)
3889 pg_data_t *pgdat = NODE_DATA(nid);
3891 pgdat->node_id = nid;
3892 pgdat->node_start_pfn = node_start_pfn;
3893 calculate_node_totalpages(pgdat, zones_size, zholes_size);
3895 alloc_node_mem_map(pgdat);
3896 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3897 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3898 nid, (unsigned long)pgdat,
3899 (unsigned long)pgdat->node_mem_map);
3902 free_area_init_core(pgdat, zones_size, zholes_size);
3905 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3907 #if MAX_NUMNODES > 1
3909 * Figure out the number of possible node ids.
3911 static void __init setup_nr_node_ids(void)
3914 unsigned int highest = 0;
3916 for_each_node_mask(node, node_possible_map)
3918 nr_node_ids = highest + 1;
3921 static inline void setup_nr_node_ids(void)
3927 * add_active_range - Register a range of PFNs backed by physical memory
3928 * @nid: The node ID the range resides on
3929 * @start_pfn: The start PFN of the available physical memory
3930 * @end_pfn: The end PFN of the available physical memory
3932 * These ranges are stored in an early_node_map[] and later used by
3933 * free_area_init_nodes() to calculate zone sizes and holes. If the
3934 * range spans a memory hole, it is up to the architecture to ensure
3935 * the memory is not freed by the bootmem allocator. If possible
3936 * the range being registered will be merged with existing ranges.
3938 void __init add_active_range(unsigned int nid, unsigned long start_pfn,
3939 unsigned long end_pfn)
3943 mminit_dprintk(MMINIT_TRACE, "memory_register",
3944 "Entering add_active_range(%d, %#lx, %#lx) "
3945 "%d entries of %d used\n",
3946 nid, start_pfn, end_pfn,
3947 nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3949 mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
3951 /* Merge with existing active regions if possible */
3952 for (i = 0; i < nr_nodemap_entries; i++) {
3953 if (early_node_map[i].nid != nid)
3956 /* Skip if an existing region covers this new one */
3957 if (start_pfn >= early_node_map[i].start_pfn &&
3958 end_pfn <= early_node_map[i].end_pfn)
3961 /* Merge forward if suitable */
3962 if (start_pfn <= early_node_map[i].end_pfn &&
3963 end_pfn > early_node_map[i].end_pfn) {
3964 early_node_map[i].end_pfn = end_pfn;
3968 /* Merge backward if suitable */
3969 if (start_pfn < early_node_map[i].end_pfn &&
3970 end_pfn >= early_node_map[i].start_pfn) {
3971 early_node_map[i].start_pfn = start_pfn;
3976 /* Check that early_node_map is large enough */
3977 if (i >= MAX_ACTIVE_REGIONS) {
3978 printk(KERN_CRIT "More than %d memory regions, truncating\n",
3979 MAX_ACTIVE_REGIONS);
3983 early_node_map[i].nid = nid;
3984 early_node_map[i].start_pfn = start_pfn;
3985 early_node_map[i].end_pfn = end_pfn;
3986 nr_nodemap_entries = i + 1;
3990 * remove_active_range - Shrink an existing registered range of PFNs
3991 * @nid: The node id the range is on that should be shrunk
3992 * @start_pfn: The new PFN of the range
3993 * @end_pfn: The new PFN of the range
3995 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3996 * The map is kept near the end physical page range that has already been
3997 * registered. This function allows an arch to shrink an existing registered
4000 void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
4001 unsigned long end_pfn)
4006 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
4007 nid, start_pfn, end_pfn);
4009 /* Find the old active region end and shrink */
4010 for_each_active_range_index_in_nid(i, nid) {
4011 if (early_node_map[i].start_pfn >= start_pfn &&
4012 early_node_map[i].end_pfn <= end_pfn) {
4014 early_node_map[i].start_pfn = 0;
4015 early_node_map[i].end_pfn = 0;
4019 if (early_node_map[i].start_pfn < start_pfn &&
4020 early_node_map[i].end_pfn > start_pfn) {
4021 unsigned long temp_end_pfn = early_node_map[i].end_pfn;
4022 early_node_map[i].end_pfn = start_pfn;
4023 if (temp_end_pfn > end_pfn)
4024 add_active_range(nid, end_pfn, temp_end_pfn);
4027 if (early_node_map[i].start_pfn >= start_pfn &&
4028 early_node_map[i].end_pfn > end_pfn &&
4029 early_node_map[i].start_pfn < end_pfn) {
4030 early_node_map[i].start_pfn = end_pfn;
4038 /* remove the blank ones */
4039 for (i = nr_nodemap_entries - 1; i > 0; i--) {
4040 if (early_node_map[i].nid != nid)
4042 if (early_node_map[i].end_pfn)
4044 /* we found it, get rid of it */
4045 for (j = i; j < nr_nodemap_entries - 1; j++)
4046 memcpy(&early_node_map[j], &early_node_map[j+1],
4047 sizeof(early_node_map[j]));
4048 j = nr_nodemap_entries - 1;
4049 memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
4050 nr_nodemap_entries--;
4055 * remove_all_active_ranges - Remove all currently registered regions
4057 * During discovery, it may be found that a table like SRAT is invalid
4058 * and an alternative discovery method must be used. This function removes
4059 * all currently registered regions.
4061 void __init remove_all_active_ranges(void)
4063 memset(early_node_map, 0, sizeof(early_node_map));
4064 nr_nodemap_entries = 0;
4067 /* Compare two active node_active_regions */
4068 static int __init cmp_node_active_region(const void *a, const void *b)
4070 struct node_active_region *arange = (struct node_active_region *)a;
4071 struct node_active_region *brange = (struct node_active_region *)b;
4073 /* Done this way to avoid overflows */
4074 if (arange->start_pfn > brange->start_pfn)
4076 if (arange->start_pfn < brange->start_pfn)
4082 /* sort the node_map by start_pfn */
4083 static void __init sort_node_map(void)
4085 sort(early_node_map, (size_t)nr_nodemap_entries,
4086 sizeof(struct node_active_region),
4087 cmp_node_active_region, NULL);
4090 /* Find the lowest pfn for a node */
4091 static unsigned long __init find_min_pfn_for_node(int nid)
4094 unsigned long min_pfn = ULONG_MAX;
4096 /* Assuming a sorted map, the first range found has the starting pfn */
4097 for_each_active_range_index_in_nid(i, nid)
4098 min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4100 if (min_pfn == ULONG_MAX) {
4102 "Could not find start_pfn for node %d\n", nid);
4110 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4112 * It returns the minimum PFN based on information provided via
4113 * add_active_range().
4115 unsigned long __init find_min_pfn_with_active_regions(void)
4117 return find_min_pfn_for_node(MAX_NUMNODES);
4121 * early_calculate_totalpages()
4122 * Sum pages in active regions for movable zone.
4123 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4125 static unsigned long __init early_calculate_totalpages(void)
4128 unsigned long totalpages = 0;
4130 for (i = 0; i < nr_nodemap_entries; i++) {
4131 unsigned long pages = early_node_map[i].end_pfn -
4132 early_node_map[i].start_pfn;
4133 totalpages += pages;
4135 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
4141 * Find the PFN the Movable zone begins in each node. Kernel memory
4142 * is spread evenly between nodes as long as the nodes have enough
4143 * memory. When they don't, some nodes will have more kernelcore than
4146 static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
4149 unsigned long usable_startpfn;
4150 unsigned long kernelcore_node, kernelcore_remaining;
4151 /* save the state before borrow the nodemask */
4152 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4153 unsigned long totalpages = early_calculate_totalpages();
4154 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
4157 * If movablecore was specified, calculate what size of
4158 * kernelcore that corresponds so that memory usable for
4159 * any allocation type is evenly spread. If both kernelcore
4160 * and movablecore are specified, then the value of kernelcore
4161 * will be used for required_kernelcore if it's greater than
4162 * what movablecore would have allowed.
4164 if (required_movablecore) {
4165 unsigned long corepages;
4168 * Round-up so that ZONE_MOVABLE is at least as large as what
4169 * was requested by the user
4171 required_movablecore =
4172 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4173 corepages = totalpages - required_movablecore;
4175 required_kernelcore = max(required_kernelcore, corepages);
4178 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4179 if (!required_kernelcore)
4182 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4183 find_usable_zone_for_movable();
4184 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4187 /* Spread kernelcore memory as evenly as possible throughout nodes */
4188 kernelcore_node = required_kernelcore / usable_nodes;
4189 for_each_node_state(nid, N_HIGH_MEMORY) {
4191 * Recalculate kernelcore_node if the division per node
4192 * now exceeds what is necessary to satisfy the requested
4193 * amount of memory for the kernel
4195 if (required_kernelcore < kernelcore_node)
4196 kernelcore_node = required_kernelcore / usable_nodes;
4199 * As the map is walked, we track how much memory is usable
4200 * by the kernel using kernelcore_remaining. When it is
4201 * 0, the rest of the node is usable by ZONE_MOVABLE
4203 kernelcore_remaining = kernelcore_node;
4205 /* Go through each range of PFNs within this node */
4206 for_each_active_range_index_in_nid(i, nid) {
4207 unsigned long start_pfn, end_pfn;
4208 unsigned long size_pages;
4210 start_pfn = max(early_node_map[i].start_pfn,
4211 zone_movable_pfn[nid]);
4212 end_pfn = early_node_map[i].end_pfn;
4213 if (start_pfn >= end_pfn)
4216 /* Account for what is only usable for kernelcore */
4217 if (start_pfn < usable_startpfn) {
4218 unsigned long kernel_pages;
4219 kernel_pages = min(end_pfn, usable_startpfn)
4222 kernelcore_remaining -= min(kernel_pages,
4223 kernelcore_remaining);
4224 required_kernelcore -= min(kernel_pages,
4225 required_kernelcore);
4227 /* Continue if range is now fully accounted */
4228 if (end_pfn <= usable_startpfn) {
4231 * Push zone_movable_pfn to the end so
4232 * that if we have to rebalance
4233 * kernelcore across nodes, we will
4234 * not double account here
4236 zone_movable_pfn[nid] = end_pfn;
4239 start_pfn = usable_startpfn;
4243 * The usable PFN range for ZONE_MOVABLE is from
4244 * start_pfn->end_pfn. Calculate size_pages as the
4245 * number of pages used as kernelcore
4247 size_pages = end_pfn - start_pfn;
4248 if (size_pages > kernelcore_remaining)
4249 size_pages = kernelcore_remaining;
4250 zone_movable_pfn[nid] = start_pfn + size_pages;
4253 * Some kernelcore has been met, update counts and
4254 * break if the kernelcore for this node has been
4257 required_kernelcore -= min(required_kernelcore,
4259 kernelcore_remaining -= size_pages;
4260 if (!kernelcore_remaining)
4266 * If there is still required_kernelcore, we do another pass with one
4267 * less node in the count. This will push zone_movable_pfn[nid] further
4268 * along on the nodes that still have memory until kernelcore is
4272 if (usable_nodes && required_kernelcore > usable_nodes)
4275 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4276 for (nid = 0; nid < MAX_NUMNODES; nid++)
4277 zone_movable_pfn[nid] =
4278 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4281 /* restore the node_state */
4282 node_states[N_HIGH_MEMORY] = saved_node_state;
4285 /* Any regular memory on that node ? */
4286 static void check_for_regular_memory(pg_data_t *pgdat)
4288 #ifdef CONFIG_HIGHMEM
4289 enum zone_type zone_type;
4291 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
4292 struct zone *zone = &pgdat->node_zones[zone_type];
4293 if (zone->present_pages)
4294 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
4300 * free_area_init_nodes - Initialise all pg_data_t and zone data
4301 * @max_zone_pfn: an array of max PFNs for each zone
4303 * This will call free_area_init_node() for each active node in the system.
4304 * Using the page ranges provided by add_active_range(), the size of each
4305 * zone in each node and their holes is calculated. If the maximum PFN
4306 * between two adjacent zones match, it is assumed that the zone is empty.
4307 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4308 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4309 * starts where the previous one ended. For example, ZONE_DMA32 starts
4310 * at arch_max_dma_pfn.
4312 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
4317 /* Sort early_node_map as initialisation assumes it is sorted */
4320 /* Record where the zone boundaries are */
4321 memset(arch_zone_lowest_possible_pfn, 0,
4322 sizeof(arch_zone_lowest_possible_pfn));
4323 memset(arch_zone_highest_possible_pfn, 0,
4324 sizeof(arch_zone_highest_possible_pfn));
4325 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
4326 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
4327 for (i = 1; i < MAX_NR_ZONES; i++) {
4328 if (i == ZONE_MOVABLE)
4330 arch_zone_lowest_possible_pfn[i] =
4331 arch_zone_highest_possible_pfn[i-1];
4332 arch_zone_highest_possible_pfn[i] =
4333 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
4335 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
4336 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
4338 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4339 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
4340 find_zone_movable_pfns_for_nodes(zone_movable_pfn);
4342 /* Print out the zone ranges */
4343 printk("Zone PFN ranges:\n");
4344 for (i = 0; i < MAX_NR_ZONES; i++) {
4345 if (i == ZONE_MOVABLE)
4347 printk(" %-8s %0#10lx -> %0#10lx\n",
4349 arch_zone_lowest_possible_pfn[i],
4350 arch_zone_highest_possible_pfn[i]);
4353 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4354 printk("Movable zone start PFN for each node\n");
4355 for (i = 0; i < MAX_NUMNODES; i++) {
4356 if (zone_movable_pfn[i])
4357 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
4360 /* Print out the early_node_map[] */
4361 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
4362 for (i = 0; i < nr_nodemap_entries; i++)
4363 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4364 early_node_map[i].start_pfn,
4365 early_node_map[i].end_pfn);
4367 /* Initialise every node */
4368 mminit_verify_pageflags_layout();
4369 setup_nr_node_ids();
4370 for_each_online_node(nid) {
4371 pg_data_t *pgdat = NODE_DATA(nid);
4372 free_area_init_node(nid, NULL,
4373 find_min_pfn_for_node(nid), NULL);
4375 /* Any memory on that node */
4376 if (pgdat->node_present_pages)
4377 node_set_state(nid, N_HIGH_MEMORY);
4378 check_for_regular_memory(pgdat);
4382 static int __init cmdline_parse_core(char *p, unsigned long *core)
4384 unsigned long long coremem;
4388 coremem = memparse(p, &p);
4389 *core = coremem >> PAGE_SHIFT;
4391 /* Paranoid check that UL is enough for the coremem value */
4392 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
4398 * kernelcore=size sets the amount of memory for use for allocations that
4399 * cannot be reclaimed or migrated.
4401 static int __init cmdline_parse_kernelcore(char *p)
4403 return cmdline_parse_core(p, &required_kernelcore);
4407 * movablecore=size sets the amount of memory for use for allocations that
4408 * can be reclaimed or migrated.
4410 static int __init cmdline_parse_movablecore(char *p)
4412 return cmdline_parse_core(p, &required_movablecore);
4415 early_param("kernelcore", cmdline_parse_kernelcore);
4416 early_param("movablecore", cmdline_parse_movablecore);
4418 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4421 * set_dma_reserve - set the specified number of pages reserved in the first zone
4422 * @new_dma_reserve: The number of pages to mark reserved
4424 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4425 * In the DMA zone, a significant percentage may be consumed by kernel image
4426 * and other unfreeable allocations which can skew the watermarks badly. This
4427 * function may optionally be used to account for unfreeable pages in the
4428 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4429 * smaller per-cpu batchsize.
4431 void __init set_dma_reserve(unsigned long new_dma_reserve)
4433 dma_reserve = new_dma_reserve;
4436 #ifndef CONFIG_NEED_MULTIPLE_NODES
4437 struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
4438 EXPORT_SYMBOL(contig_page_data);
4441 void __init free_area_init(unsigned long *zones_size)
4443 free_area_init_node(0, zones_size,
4444 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
4447 static int page_alloc_cpu_notify(struct notifier_block *self,
4448 unsigned long action, void *hcpu)
4450 int cpu = (unsigned long)hcpu;
4452 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4456 * Spill the event counters of the dead processor
4457 * into the current processors event counters.
4458 * This artificially elevates the count of the current
4461 vm_events_fold_cpu(cpu);
4464 * Zero the differential counters of the dead processor
4465 * so that the vm statistics are consistent.
4467 * This is only okay since the processor is dead and cannot
4468 * race with what we are doing.
4470 refresh_cpu_vm_stats(cpu);
4475 void __init page_alloc_init(void)
4477 hotcpu_notifier(page_alloc_cpu_notify, 0);
4481 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4482 * or min_free_kbytes changes.
4484 static void calculate_totalreserve_pages(void)
4486 struct pglist_data *pgdat;
4487 unsigned long reserve_pages = 0;
4488 enum zone_type i, j;
4490 for_each_online_pgdat(pgdat) {
4491 for (i = 0; i < MAX_NR_ZONES; i++) {
4492 struct zone *zone = pgdat->node_zones + i;
4493 unsigned long max = 0;
4495 /* Find valid and maximum lowmem_reserve in the zone */
4496 for (j = i; j < MAX_NR_ZONES; j++) {
4497 if (zone->lowmem_reserve[j] > max)
4498 max = zone->lowmem_reserve[j];
4501 /* we treat the high watermark as reserved pages. */
4502 max += high_wmark_pages(zone);
4504 if (max > zone->present_pages)
4505 max = zone->present_pages;
4506 reserve_pages += max;
4509 totalreserve_pages = reserve_pages;
4513 * setup_per_zone_lowmem_reserve - called whenever
4514 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4515 * has a correct pages reserved value, so an adequate number of
4516 * pages are left in the zone after a successful __alloc_pages().
4518 static void setup_per_zone_lowmem_reserve(void)
4520 struct pglist_data *pgdat;
4521 enum zone_type j, idx;
4523 for_each_online_pgdat(pgdat) {
4524 for (j = 0; j < MAX_NR_ZONES; j++) {
4525 struct zone *zone = pgdat->node_zones + j;
4526 unsigned long present_pages = zone->present_pages;
4528 zone->lowmem_reserve[j] = 0;
4532 struct zone *lower_zone;
4536 if (sysctl_lowmem_reserve_ratio[idx] < 1)
4537 sysctl_lowmem_reserve_ratio[idx] = 1;
4539 lower_zone = pgdat->node_zones + idx;
4540 lower_zone->lowmem_reserve[j] = present_pages /
4541 sysctl_lowmem_reserve_ratio[idx];
4542 present_pages += lower_zone->present_pages;
4547 /* update totalreserve_pages */
4548 calculate_totalreserve_pages();
4552 * setup_per_zone_wmarks - called when min_free_kbytes changes
4553 * or when memory is hot-{added|removed}
4555 * Ensures that the watermark[min,low,high] values for each zone are set
4556 * correctly with respect to min_free_kbytes.
4558 void setup_per_zone_wmarks(void)
4560 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
4561 unsigned long lowmem_pages = 0;
4563 unsigned long flags;
4565 /* Calculate total number of !ZONE_HIGHMEM pages */
4566 for_each_zone(zone) {
4567 if (!is_highmem(zone))
4568 lowmem_pages += zone->present_pages;
4571 for_each_zone(zone) {
4574 spin_lock_irqsave(&zone->lock, flags);
4575 tmp = (u64)pages_min * zone->present_pages;
4576 do_div(tmp, lowmem_pages);
4577 if (is_highmem(zone)) {
4579 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4580 * need highmem pages, so cap pages_min to a small
4583 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4584 * deltas controls asynch page reclaim, and so should
4585 * not be capped for highmem.
4589 min_pages = zone->present_pages / 1024;
4590 if (min_pages < SWAP_CLUSTER_MAX)
4591 min_pages = SWAP_CLUSTER_MAX;
4592 if (min_pages > 128)
4594 zone->watermark[WMARK_MIN] = min_pages;
4597 * If it's a lowmem zone, reserve a number of pages
4598 * proportionate to the zone's size.
4600 zone->watermark[WMARK_MIN] = tmp;
4603 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
4604 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4605 setup_zone_migrate_reserve(zone);
4606 spin_unlock_irqrestore(&zone->lock, flags);
4609 /* update totalreserve_pages */
4610 calculate_totalreserve_pages();
4614 * The inactive anon list should be small enough that the VM never has to
4615 * do too much work, but large enough that each inactive page has a chance
4616 * to be referenced again before it is swapped out.
4618 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4619 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4620 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4621 * the anonymous pages are kept on the inactive list.
4624 * memory ratio inactive anon
4625 * -------------------------------------
4634 void calculate_zone_inactive_ratio(struct zone *zone)
4636 unsigned int gb, ratio;
4638 /* Zone size in gigabytes */
4639 gb = zone->present_pages >> (30 - PAGE_SHIFT);
4641 ratio = int_sqrt(10 * gb);
4645 zone->inactive_ratio = ratio;
4648 static void __init setup_per_zone_inactive_ratio(void)
4653 calculate_zone_inactive_ratio(zone);
4657 * Initialise min_free_kbytes.
4659 * For small machines we want it small (128k min). For large machines
4660 * we want it large (64MB max). But it is not linear, because network
4661 * bandwidth does not increase linearly with machine size. We use
4663 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4664 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4680 static int __init init_per_zone_wmark_min(void)
4682 unsigned long lowmem_kbytes;
4684 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
4686 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
4687 if (min_free_kbytes < 128)
4688 min_free_kbytes = 128;
4689 if (min_free_kbytes > 65536)
4690 min_free_kbytes = 65536;
4691 setup_per_zone_wmarks();
4692 setup_per_zone_lowmem_reserve();
4693 setup_per_zone_inactive_ratio();
4696 module_init(init_per_zone_wmark_min)
4699 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4700 * that we can call two helper functions whenever min_free_kbytes
4703 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
4704 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4706 proc_dointvec(table, write, file, buffer, length, ppos);
4708 setup_per_zone_wmarks();
4713 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4714 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4719 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4724 zone->min_unmapped_pages = (zone->present_pages *
4725 sysctl_min_unmapped_ratio) / 100;
4729 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4730 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4735 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4740 zone->min_slab_pages = (zone->present_pages *
4741 sysctl_min_slab_ratio) / 100;
4747 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4748 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4749 * whenever sysctl_lowmem_reserve_ratio changes.
4751 * The reserve ratio obviously has absolutely no relation with the
4752 * minimum watermarks. The lowmem reserve ratio can only make sense
4753 * if in function of the boot time zone sizes.
4755 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4756 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4758 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4759 setup_per_zone_lowmem_reserve();
4764 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4765 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4766 * can have before it gets flushed back to buddy allocator.
4769 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
4770 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4776 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4777 if (!write || (ret == -EINVAL))
4779 for_each_populated_zone(zone) {
4780 for_each_online_cpu(cpu) {
4782 high = zone->present_pages / percpu_pagelist_fraction;
4783 setup_pagelist_highmark(zone_pcp(zone, cpu), high);
4789 int hashdist = HASHDIST_DEFAULT;
4792 static int __init set_hashdist(char *str)
4796 hashdist = simple_strtoul(str, &str, 0);
4799 __setup("hashdist=", set_hashdist);
4803 * allocate a large system hash table from bootmem
4804 * - it is assumed that the hash table must contain an exact power-of-2
4805 * quantity of entries
4806 * - limit is the number of hash buckets, not the total allocation size
4808 void *__init alloc_large_system_hash(const char *tablename,
4809 unsigned long bucketsize,
4810 unsigned long numentries,
4813 unsigned int *_hash_shift,
4814 unsigned int *_hash_mask,
4815 unsigned long limit)
4817 unsigned long long max = limit;
4818 unsigned long log2qty, size;
4821 /* allow the kernel cmdline to have a say */
4823 /* round applicable memory size up to nearest megabyte */
4824 numentries = nr_kernel_pages;
4825 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
4826 numentries >>= 20 - PAGE_SHIFT;
4827 numentries <<= 20 - PAGE_SHIFT;
4829 /* limit to 1 bucket per 2^scale bytes of low memory */
4830 if (scale > PAGE_SHIFT)
4831 numentries >>= (scale - PAGE_SHIFT);
4833 numentries <<= (PAGE_SHIFT - scale);
4835 /* Make sure we've got at least a 0-order allocation.. */
4836 if (unlikely(flags & HASH_SMALL)) {
4837 /* Makes no sense without HASH_EARLY */
4838 WARN_ON(!(flags & HASH_EARLY));
4839 if (!(numentries >> *_hash_shift)) {
4840 numentries = 1UL << *_hash_shift;
4841 BUG_ON(!numentries);
4843 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4844 numentries = PAGE_SIZE / bucketsize;
4846 numentries = roundup_pow_of_two(numentries);
4848 /* limit allocation size to 1/16 total memory by default */
4850 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
4851 do_div(max, bucketsize);
4854 if (numentries > max)
4857 log2qty = ilog2(numentries);
4860 size = bucketsize << log2qty;
4861 if (flags & HASH_EARLY)
4862 table = alloc_bootmem_nopanic(size);
4864 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
4867 * If bucketsize is not a power-of-two, we may free
4868 * some pages at the end of hash table which
4869 * alloc_pages_exact() automatically does
4871 if (get_order(size) < MAX_ORDER) {
4872 table = alloc_pages_exact(size, GFP_ATOMIC);
4873 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
4876 } while (!table && size > PAGE_SIZE && --log2qty);
4879 panic("Failed to allocate %s hash table\n", tablename);
4881 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
4884 ilog2(size) - PAGE_SHIFT,
4888 *_hash_shift = log2qty;
4890 *_hash_mask = (1 << log2qty) - 1;
4895 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4896 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
4899 #ifdef CONFIG_SPARSEMEM
4900 return __pfn_to_section(pfn)->pageblock_flags;
4902 return zone->pageblock_flags;
4903 #endif /* CONFIG_SPARSEMEM */
4906 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
4908 #ifdef CONFIG_SPARSEMEM
4909 pfn &= (PAGES_PER_SECTION-1);
4910 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4912 pfn = pfn - zone->zone_start_pfn;
4913 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4914 #endif /* CONFIG_SPARSEMEM */
4918 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4919 * @page: The page within the block of interest
4920 * @start_bitidx: The first bit of interest to retrieve
4921 * @end_bitidx: The last bit of interest
4922 * returns pageblock_bits flags
4924 unsigned long get_pageblock_flags_group(struct page *page,
4925 int start_bitidx, int end_bitidx)
4928 unsigned long *bitmap;
4929 unsigned long pfn, bitidx;
4930 unsigned long flags = 0;
4931 unsigned long value = 1;
4933 zone = page_zone(page);
4934 pfn = page_to_pfn(page);
4935 bitmap = get_pageblock_bitmap(zone, pfn);
4936 bitidx = pfn_to_bitidx(zone, pfn);
4938 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4939 if (test_bit(bitidx + start_bitidx, bitmap))
4946 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4947 * @page: The page within the block of interest
4948 * @start_bitidx: The first bit of interest
4949 * @end_bitidx: The last bit of interest
4950 * @flags: The flags to set
4952 void set_pageblock_flags_group(struct page *page, unsigned long flags,
4953 int start_bitidx, int end_bitidx)
4956 unsigned long *bitmap;
4957 unsigned long pfn, bitidx;
4958 unsigned long value = 1;
4960 zone = page_zone(page);
4961 pfn = page_to_pfn(page);
4962 bitmap = get_pageblock_bitmap(zone, pfn);
4963 bitidx = pfn_to_bitidx(zone, pfn);
4964 VM_BUG_ON(pfn < zone->zone_start_pfn);
4965 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4967 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4969 __set_bit(bitidx + start_bitidx, bitmap);
4971 __clear_bit(bitidx + start_bitidx, bitmap);
4975 * This is designed as sub function...plz see page_isolation.c also.
4976 * set/clear page block's type to be ISOLATE.
4977 * page allocater never alloc memory from ISOLATE block.
4980 int set_migratetype_isolate(struct page *page)
4983 unsigned long flags;
4987 zone = page_zone(page);
4988 zone_idx = zone_idx(zone);
4989 spin_lock_irqsave(&zone->lock, flags);
4991 * In future, more migrate types will be able to be isolation target.
4993 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
4994 zone_idx != ZONE_MOVABLE)
4996 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
4997 move_freepages_block(zone, page, MIGRATE_ISOLATE);
5000 spin_unlock_irqrestore(&zone->lock, flags);
5006 void unset_migratetype_isolate(struct page *page)
5009 unsigned long flags;
5010 zone = page_zone(page);
5011 spin_lock_irqsave(&zone->lock, flags);
5012 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
5014 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5015 move_freepages_block(zone, page, MIGRATE_MOVABLE);
5017 spin_unlock_irqrestore(&zone->lock, flags);
5020 #ifdef CONFIG_MEMORY_HOTREMOVE
5022 * All pages in the range must be isolated before calling this.
5025 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
5031 unsigned long flags;
5032 /* find the first valid pfn */
5033 for (pfn = start_pfn; pfn < end_pfn; pfn++)
5038 zone = page_zone(pfn_to_page(pfn));
5039 spin_lock_irqsave(&zone->lock, flags);
5041 while (pfn < end_pfn) {
5042 if (!pfn_valid(pfn)) {
5046 page = pfn_to_page(pfn);
5047 BUG_ON(page_count(page));
5048 BUG_ON(!PageBuddy(page));
5049 order = page_order(page);
5050 #ifdef CONFIG_DEBUG_VM
5051 printk(KERN_INFO "remove from free list %lx %d %lx\n",
5052 pfn, 1 << order, end_pfn);
5054 list_del(&page->lru);
5055 rmv_page_order(page);
5056 zone->free_area[order].nr_free--;
5057 __mod_zone_page_state(zone, NR_FREE_PAGES,
5059 for (i = 0; i < (1 << order); i++)
5060 SetPageReserved((page+i));
5061 pfn += (1 << order);
5063 spin_unlock_irqrestore(&zone->lock, flags);