2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/compiler.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/suspend.h>
28 #include <linux/pagevec.h>
29 #include <linux/blkdev.h>
30 #include <linux/slab.h>
31 #include <linux/oom.h>
32 #include <linux/notifier.h>
33 #include <linux/topology.h>
34 #include <linux/sysctl.h>
35 #include <linux/cpu.h>
36 #include <linux/cpuset.h>
37 #include <linux/memory_hotplug.h>
38 #include <linux/nodemask.h>
39 #include <linux/vmalloc.h>
40 #include <linux/mempolicy.h>
41 #include <linux/stop_machine.h>
42 #include <linux/sort.h>
43 #include <linux/pfn.h>
44 #include <linux/backing-dev.h>
45 #include <linux/fault-inject.h>
46 #include <linux/page-isolation.h>
47 #include <linux/memcontrol.h>
49 #include <asm/tlbflush.h>
50 #include <asm/div64.h>
54 * Array of node states.
56 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
57 [N_POSSIBLE] = NODE_MASK_ALL,
58 [N_ONLINE] = { { [0] = 1UL } },
60 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
62 [N_HIGH_MEMORY] = { { [0] = 1UL } },
64 [N_CPU] = { { [0] = 1UL } },
67 EXPORT_SYMBOL(node_states);
69 unsigned long totalram_pages __read_mostly;
70 unsigned long totalreserve_pages __read_mostly;
72 int percpu_pagelist_fraction;
74 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
75 int pageblock_order __read_mostly;
78 static void __free_pages_ok(struct page *page, unsigned int order);
81 * results with 256, 32 in the lowmem_reserve sysctl:
82 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
83 * 1G machine -> (16M dma, 784M normal, 224M high)
84 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
85 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
86 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
88 * TBD: should special case ZONE_DMA32 machines here - in those we normally
89 * don't need any ZONE_NORMAL reservation
91 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
92 #ifdef CONFIG_ZONE_DMA
95 #ifdef CONFIG_ZONE_DMA32
104 EXPORT_SYMBOL(totalram_pages);
106 static char * const zone_names[MAX_NR_ZONES] = {
107 #ifdef CONFIG_ZONE_DMA
110 #ifdef CONFIG_ZONE_DMA32
114 #ifdef CONFIG_HIGHMEM
120 int min_free_kbytes = 1024;
122 unsigned long __meminitdata nr_kernel_pages;
123 unsigned long __meminitdata nr_all_pages;
124 static unsigned long __meminitdata dma_reserve;
126 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
128 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
129 * ranges of memory (RAM) that may be registered with add_active_range().
130 * Ranges passed to add_active_range() will be merged if possible
131 * so the number of times add_active_range() can be called is
132 * related to the number of nodes and the number of holes
134 #ifdef CONFIG_MAX_ACTIVE_REGIONS
135 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
136 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
138 #if MAX_NUMNODES >= 32
139 /* If there can be many nodes, allow up to 50 holes per node */
140 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
142 /* By default, allow up to 256 distinct regions */
143 #define MAX_ACTIVE_REGIONS 256
147 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
148 static int __meminitdata nr_nodemap_entries;
149 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
150 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
151 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
152 static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES];
153 static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES];
154 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
155 unsigned long __initdata required_kernelcore;
156 static unsigned long __initdata required_movablecore;
157 unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
159 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
161 EXPORT_SYMBOL(movable_zone);
162 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
165 int nr_node_ids __read_mostly = MAX_NUMNODES;
166 EXPORT_SYMBOL(nr_node_ids);
169 int page_group_by_mobility_disabled __read_mostly;
171 static void set_pageblock_migratetype(struct page *page, int migratetype)
173 set_pageblock_flags_group(page, (unsigned long)migratetype,
174 PB_migrate, PB_migrate_end);
177 #ifdef CONFIG_DEBUG_VM
178 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
182 unsigned long pfn = page_to_pfn(page);
185 seq = zone_span_seqbegin(zone);
186 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
188 else if (pfn < zone->zone_start_pfn)
190 } while (zone_span_seqretry(zone, seq));
195 static int page_is_consistent(struct zone *zone, struct page *page)
197 if (!pfn_valid_within(page_to_pfn(page)))
199 if (zone != page_zone(page))
205 * Temporary debugging check for pages not lying within a given zone.
207 static int bad_range(struct zone *zone, struct page *page)
209 if (page_outside_zone_boundaries(zone, page))
211 if (!page_is_consistent(zone, page))
217 static inline int bad_range(struct zone *zone, struct page *page)
223 static void bad_page(struct page *page)
225 void *pc = page_get_page_cgroup(page);
227 printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
228 "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
229 current->comm, page, (int)(2*sizeof(unsigned long)),
230 (unsigned long)page->flags, page->mapping,
231 page_mapcount(page), page_count(page));
233 printk(KERN_EMERG "cgroup:%p\n", pc);
234 page_reset_bad_cgroup(page);
236 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
237 KERN_EMERG "Backtrace:\n");
239 page->flags &= ~(1 << PG_lru |
249 set_page_count(page, 0);
250 reset_page_mapcount(page);
251 page->mapping = NULL;
252 add_taint(TAINT_BAD_PAGE);
256 * Higher-order pages are called "compound pages". They are structured thusly:
258 * The first PAGE_SIZE page is called the "head page".
260 * The remaining PAGE_SIZE pages are called "tail pages".
262 * All pages have PG_compound set. All pages have their ->private pointing at
263 * the head page (even the head page has this).
265 * The first tail page's ->lru.next holds the address of the compound page's
266 * put_page() function. Its ->lru.prev holds the order of allocation.
267 * This usage means that zero-order pages may not be compound.
270 static void free_compound_page(struct page *page)
272 __free_pages_ok(page, compound_order(page));
275 static void prep_compound_page(struct page *page, unsigned long order)
278 int nr_pages = 1 << order;
280 set_compound_page_dtor(page, free_compound_page);
281 set_compound_order(page, order);
283 for (i = 1; i < nr_pages; i++) {
284 struct page *p = page + i;
287 p->first_page = page;
291 static void destroy_compound_page(struct page *page, unsigned long order)
294 int nr_pages = 1 << order;
296 if (unlikely(compound_order(page) != order))
299 if (unlikely(!PageHead(page)))
301 __ClearPageHead(page);
302 for (i = 1; i < nr_pages; i++) {
303 struct page *p = page + i;
305 if (unlikely(!PageTail(p) |
306 (p->first_page != page)))
312 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
317 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
318 * and __GFP_HIGHMEM from hard or soft interrupt context.
320 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
321 for (i = 0; i < (1 << order); i++)
322 clear_highpage(page + i);
325 static inline void set_page_order(struct page *page, int order)
327 set_page_private(page, order);
328 __SetPageBuddy(page);
331 static inline void rmv_page_order(struct page *page)
333 __ClearPageBuddy(page);
334 set_page_private(page, 0);
338 * Locate the struct page for both the matching buddy in our
339 * pair (buddy1) and the combined O(n+1) page they form (page).
341 * 1) Any buddy B1 will have an order O twin B2 which satisfies
342 * the following equation:
344 * For example, if the starting buddy (buddy2) is #8 its order
346 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
348 * 2) Any buddy B will have an order O+1 parent P which
349 * satisfies the following equation:
352 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
354 static inline struct page *
355 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
357 unsigned long buddy_idx = page_idx ^ (1 << order);
359 return page + (buddy_idx - page_idx);
362 static inline unsigned long
363 __find_combined_index(unsigned long page_idx, unsigned int order)
365 return (page_idx & ~(1 << order));
369 * This function checks whether a page is free && is the buddy
370 * we can do coalesce a page and its buddy if
371 * (a) the buddy is not in a hole &&
372 * (b) the buddy is in the buddy system &&
373 * (c) a page and its buddy have the same order &&
374 * (d) a page and its buddy are in the same zone.
376 * For recording whether a page is in the buddy system, we use PG_buddy.
377 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
379 * For recording page's order, we use page_private(page).
381 static inline int page_is_buddy(struct page *page, struct page *buddy,
384 if (!pfn_valid_within(page_to_pfn(buddy)))
387 if (page_zone_id(page) != page_zone_id(buddy))
390 if (PageBuddy(buddy) && page_order(buddy) == order) {
391 BUG_ON(page_count(buddy) != 0);
398 * Freeing function for a buddy system allocator.
400 * The concept of a buddy system is to maintain direct-mapped table
401 * (containing bit values) for memory blocks of various "orders".
402 * The bottom level table contains the map for the smallest allocatable
403 * units of memory (here, pages), and each level above it describes
404 * pairs of units from the levels below, hence, "buddies".
405 * At a high level, all that happens here is marking the table entry
406 * at the bottom level available, and propagating the changes upward
407 * as necessary, plus some accounting needed to play nicely with other
408 * parts of the VM system.
409 * At each level, we keep a list of pages, which are heads of continuous
410 * free pages of length of (1 << order) and marked with PG_buddy. Page's
411 * order is recorded in page_private(page) field.
412 * So when we are allocating or freeing one, we can derive the state of the
413 * other. That is, if we allocate a small block, and both were
414 * free, the remainder of the region must be split into blocks.
415 * If a block is freed, and its buddy is also free, then this
416 * triggers coalescing into a block of larger size.
421 static inline void __free_one_page(struct page *page,
422 struct zone *zone, unsigned int order)
424 unsigned long page_idx;
425 int order_size = 1 << order;
426 int migratetype = get_pageblock_migratetype(page);
428 if (unlikely(PageCompound(page)))
429 destroy_compound_page(page, order);
431 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
433 VM_BUG_ON(page_idx & (order_size - 1));
434 VM_BUG_ON(bad_range(zone, page));
436 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
437 while (order < MAX_ORDER-1) {
438 unsigned long combined_idx;
441 buddy = __page_find_buddy(page, page_idx, order);
442 if (!page_is_buddy(page, buddy, order))
443 break; /* Move the buddy up one level. */
445 list_del(&buddy->lru);
446 zone->free_area[order].nr_free--;
447 rmv_page_order(buddy);
448 combined_idx = __find_combined_index(page_idx, order);
449 page = page + (combined_idx - page_idx);
450 page_idx = combined_idx;
453 set_page_order(page, order);
455 &zone->free_area[order].free_list[migratetype]);
456 zone->free_area[order].nr_free++;
459 static inline int free_pages_check(struct page *page)
461 if (unlikely(page_mapcount(page) |
462 (page->mapping != NULL) |
463 (page_get_page_cgroup(page) != NULL) |
464 (page_count(page) != 0) |
477 __ClearPageDirty(page);
479 * For now, we report if PG_reserved was found set, but do not
480 * clear it, and do not free the page. But we shall soon need
481 * to do more, for when the ZERO_PAGE count wraps negative.
483 return PageReserved(page);
487 * Frees a list of pages.
488 * Assumes all pages on list are in same zone, and of same order.
489 * count is the number of pages to free.
491 * If the zone was previously in an "all pages pinned" state then look to
492 * see if this freeing clears that state.
494 * And clear the zone's pages_scanned counter, to hold off the "all pages are
495 * pinned" detection logic.
497 static void free_pages_bulk(struct zone *zone, int count,
498 struct list_head *list, int order)
500 spin_lock(&zone->lock);
501 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
502 zone->pages_scanned = 0;
506 VM_BUG_ON(list_empty(list));
507 page = list_entry(list->prev, struct page, lru);
508 /* have to delete it as __free_one_page list manipulates */
509 list_del(&page->lru);
510 __free_one_page(page, zone, order);
512 spin_unlock(&zone->lock);
515 static void free_one_page(struct zone *zone, struct page *page, int order)
517 spin_lock(&zone->lock);
518 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
519 zone->pages_scanned = 0;
520 __free_one_page(page, zone, order);
521 spin_unlock(&zone->lock);
524 static void __free_pages_ok(struct page *page, unsigned int order)
530 for (i = 0 ; i < (1 << order) ; ++i)
531 reserved += free_pages_check(page + i);
535 if (!PageHighMem(page))
536 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
537 arch_free_page(page, order);
538 kernel_map_pages(page, 1 << order, 0);
540 local_irq_save(flags);
541 __count_vm_events(PGFREE, 1 << order);
542 free_one_page(page_zone(page), page, order);
543 local_irq_restore(flags);
547 * permit the bootmem allocator to evade page validation on high-order frees
549 void __init __free_pages_bootmem(struct page *page, unsigned int order)
552 __ClearPageReserved(page);
553 set_page_count(page, 0);
554 set_page_refcounted(page);
560 for (loop = 0; loop < BITS_PER_LONG; loop++) {
561 struct page *p = &page[loop];
563 if (loop + 1 < BITS_PER_LONG)
565 __ClearPageReserved(p);
566 set_page_count(p, 0);
569 set_page_refcounted(page);
570 __free_pages(page, order);
576 * The order of subdivision here is critical for the IO subsystem.
577 * Please do not alter this order without good reasons and regression
578 * testing. Specifically, as large blocks of memory are subdivided,
579 * the order in which smaller blocks are delivered depends on the order
580 * they're subdivided in this function. This is the primary factor
581 * influencing the order in which pages are delivered to the IO
582 * subsystem according to empirical testing, and this is also justified
583 * by considering the behavior of a buddy system containing a single
584 * large block of memory acted on by a series of small allocations.
585 * This behavior is a critical factor in sglist merging's success.
589 static inline void expand(struct zone *zone, struct page *page,
590 int low, int high, struct free_area *area,
593 unsigned long size = 1 << high;
599 VM_BUG_ON(bad_range(zone, &page[size]));
600 list_add(&page[size].lru, &area->free_list[migratetype]);
602 set_page_order(&page[size], high);
607 * This page is about to be returned from the page allocator
609 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
611 if (unlikely(page_mapcount(page) |
612 (page->mapping != NULL) |
613 (page_get_page_cgroup(page) != NULL) |
614 (page_count(page) != 0) |
629 * For now, we report if PG_reserved was found set, but do not
630 * clear it, and do not allocate the page: as a safety net.
632 if (PageReserved(page))
635 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead |
636 1 << PG_referenced | 1 << PG_arch_1 |
637 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
638 set_page_private(page, 0);
639 set_page_refcounted(page);
641 arch_alloc_page(page, order);
642 kernel_map_pages(page, 1 << order, 1);
644 if (gfp_flags & __GFP_ZERO)
645 prep_zero_page(page, order, gfp_flags);
647 if (order && (gfp_flags & __GFP_COMP))
648 prep_compound_page(page, order);
654 * Go through the free lists for the given migratetype and remove
655 * the smallest available page from the freelists
657 static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
660 unsigned int current_order;
661 struct free_area * area;
664 /* Find a page of the appropriate size in the preferred list */
665 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
666 area = &(zone->free_area[current_order]);
667 if (list_empty(&area->free_list[migratetype]))
670 page = list_entry(area->free_list[migratetype].next,
672 list_del(&page->lru);
673 rmv_page_order(page);
675 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
676 expand(zone, page, order, current_order, area, migratetype);
685 * This array describes the order lists are fallen back to when
686 * the free lists for the desirable migrate type are depleted
688 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
689 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
690 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
691 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
692 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
696 * Move the free pages in a range to the free lists of the requested type.
697 * Note that start_page and end_pages are not aligned on a pageblock
698 * boundary. If alignment is required, use move_freepages_block()
700 int move_freepages(struct zone *zone,
701 struct page *start_page, struct page *end_page,
708 #ifndef CONFIG_HOLES_IN_ZONE
710 * page_zone is not safe to call in this context when
711 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
712 * anyway as we check zone boundaries in move_freepages_block().
713 * Remove at a later date when no bug reports exist related to
714 * grouping pages by mobility
716 BUG_ON(page_zone(start_page) != page_zone(end_page));
719 for (page = start_page; page <= end_page;) {
720 if (!pfn_valid_within(page_to_pfn(page))) {
725 if (!PageBuddy(page)) {
730 order = page_order(page);
731 list_del(&page->lru);
733 &zone->free_area[order].free_list[migratetype]);
735 pages_moved += 1 << order;
741 int move_freepages_block(struct zone *zone, struct page *page, int migratetype)
743 unsigned long start_pfn, end_pfn;
744 struct page *start_page, *end_page;
746 start_pfn = page_to_pfn(page);
747 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
748 start_page = pfn_to_page(start_pfn);
749 end_page = start_page + pageblock_nr_pages - 1;
750 end_pfn = start_pfn + pageblock_nr_pages - 1;
752 /* Do not cross zone boundaries */
753 if (start_pfn < zone->zone_start_pfn)
755 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
758 return move_freepages(zone, start_page, end_page, migratetype);
761 /* Remove an element from the buddy allocator from the fallback list */
762 static struct page *__rmqueue_fallback(struct zone *zone, int order,
763 int start_migratetype)
765 struct free_area * area;
770 /* Find the largest possible block of pages in the other list */
771 for (current_order = MAX_ORDER-1; current_order >= order;
773 for (i = 0; i < MIGRATE_TYPES - 1; i++) {
774 migratetype = fallbacks[start_migratetype][i];
776 /* MIGRATE_RESERVE handled later if necessary */
777 if (migratetype == MIGRATE_RESERVE)
780 area = &(zone->free_area[current_order]);
781 if (list_empty(&area->free_list[migratetype]))
784 page = list_entry(area->free_list[migratetype].next,
789 * If breaking a large block of pages, move all free
790 * pages to the preferred allocation list. If falling
791 * back for a reclaimable kernel allocation, be more
792 * agressive about taking ownership of free pages
794 if (unlikely(current_order >= (pageblock_order >> 1)) ||
795 start_migratetype == MIGRATE_RECLAIMABLE) {
797 pages = move_freepages_block(zone, page,
800 /* Claim the whole block if over half of it is free */
801 if (pages >= (1 << (pageblock_order-1)))
802 set_pageblock_migratetype(page,
805 migratetype = start_migratetype;
808 /* Remove the page from the freelists */
809 list_del(&page->lru);
810 rmv_page_order(page);
811 __mod_zone_page_state(zone, NR_FREE_PAGES,
814 if (current_order == pageblock_order)
815 set_pageblock_migratetype(page,
818 expand(zone, page, order, current_order, area, migratetype);
823 /* Use MIGRATE_RESERVE rather than fail an allocation */
824 return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
828 * Do the hard work of removing an element from the buddy allocator.
829 * Call me with the zone->lock already held.
831 static struct page *__rmqueue(struct zone *zone, unsigned int order,
836 page = __rmqueue_smallest(zone, order, migratetype);
839 page = __rmqueue_fallback(zone, order, migratetype);
845 * Obtain a specified number of elements from the buddy allocator, all under
846 * a single hold of the lock, for efficiency. Add them to the supplied list.
847 * Returns the number of new pages which were placed at *list.
849 static int rmqueue_bulk(struct zone *zone, unsigned int order,
850 unsigned long count, struct list_head *list,
855 spin_lock(&zone->lock);
856 for (i = 0; i < count; ++i) {
857 struct page *page = __rmqueue(zone, order, migratetype);
858 if (unlikely(page == NULL))
862 * Split buddy pages returned by expand() are received here
863 * in physical page order. The page is added to the callers and
864 * list and the list head then moves forward. From the callers
865 * perspective, the linked list is ordered by page number in
866 * some conditions. This is useful for IO devices that can
867 * merge IO requests if the physical pages are ordered
870 list_add(&page->lru, list);
871 set_page_private(page, migratetype);
874 spin_unlock(&zone->lock);
880 * Called from the vmstat counter updater to drain pagesets of this
881 * currently executing processor on remote nodes after they have
884 * Note that this function must be called with the thread pinned to
885 * a single processor.
887 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
892 local_irq_save(flags);
893 if (pcp->count >= pcp->batch)
894 to_drain = pcp->batch;
896 to_drain = pcp->count;
897 free_pages_bulk(zone, to_drain, &pcp->list, 0);
898 pcp->count -= to_drain;
899 local_irq_restore(flags);
904 * Drain pages of the indicated processor.
906 * The processor must either be the current processor and the
907 * thread pinned to the current processor or a processor that
910 static void drain_pages(unsigned int cpu)
915 for_each_zone(zone) {
916 struct per_cpu_pageset *pset;
917 struct per_cpu_pages *pcp;
919 if (!populated_zone(zone))
922 pset = zone_pcp(zone, cpu);
925 local_irq_save(flags);
926 free_pages_bulk(zone, pcp->count, &pcp->list, 0);
928 local_irq_restore(flags);
933 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
935 void drain_local_pages(void *arg)
937 drain_pages(smp_processor_id());
941 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
943 void drain_all_pages(void)
945 on_each_cpu(drain_local_pages, NULL, 0, 1);
948 #ifdef CONFIG_HIBERNATION
950 void mark_free_pages(struct zone *zone)
952 unsigned long pfn, max_zone_pfn;
955 struct list_head *curr;
957 if (!zone->spanned_pages)
960 spin_lock_irqsave(&zone->lock, flags);
962 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
963 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
964 if (pfn_valid(pfn)) {
965 struct page *page = pfn_to_page(pfn);
967 if (!swsusp_page_is_forbidden(page))
968 swsusp_unset_page_free(page);
971 for_each_migratetype_order(order, t) {
972 list_for_each(curr, &zone->free_area[order].free_list[t]) {
975 pfn = page_to_pfn(list_entry(curr, struct page, lru));
976 for (i = 0; i < (1UL << order); i++)
977 swsusp_set_page_free(pfn_to_page(pfn + i));
980 spin_unlock_irqrestore(&zone->lock, flags);
982 #endif /* CONFIG_PM */
985 * Free a 0-order page
987 static void free_hot_cold_page(struct page *page, int cold)
989 struct zone *zone = page_zone(page);
990 struct per_cpu_pages *pcp;
994 page->mapping = NULL;
995 if (free_pages_check(page))
998 if (!PageHighMem(page))
999 debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1000 arch_free_page(page, 0);
1001 kernel_map_pages(page, 1, 0);
1003 pcp = &zone_pcp(zone, get_cpu())->pcp;
1004 local_irq_save(flags);
1005 __count_vm_event(PGFREE);
1007 list_add_tail(&page->lru, &pcp->list);
1009 list_add(&page->lru, &pcp->list);
1010 set_page_private(page, get_pageblock_migratetype(page));
1012 if (pcp->count >= pcp->high) {
1013 free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
1014 pcp->count -= pcp->batch;
1016 local_irq_restore(flags);
1020 void free_hot_page(struct page *page)
1022 free_hot_cold_page(page, 0);
1025 void free_cold_page(struct page *page)
1027 free_hot_cold_page(page, 1);
1031 * split_page takes a non-compound higher-order page, and splits it into
1032 * n (1<<order) sub-pages: page[0..n]
1033 * Each sub-page must be freed individually.
1035 * Note: this is probably too low level an operation for use in drivers.
1036 * Please consult with lkml before using this in your driver.
1038 void split_page(struct page *page, unsigned int order)
1042 VM_BUG_ON(PageCompound(page));
1043 VM_BUG_ON(!page_count(page));
1044 for (i = 1; i < (1 << order); i++)
1045 set_page_refcounted(page + i);
1049 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1050 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1053 static struct page *buffered_rmqueue(struct zone *preferred_zone,
1054 struct zone *zone, int order, gfp_t gfp_flags)
1056 unsigned long flags;
1058 int cold = !!(gfp_flags & __GFP_COLD);
1060 int migratetype = allocflags_to_migratetype(gfp_flags);
1064 if (likely(order == 0)) {
1065 struct per_cpu_pages *pcp;
1067 pcp = &zone_pcp(zone, cpu)->pcp;
1068 local_irq_save(flags);
1070 pcp->count = rmqueue_bulk(zone, 0,
1071 pcp->batch, &pcp->list, migratetype);
1072 if (unlikely(!pcp->count))
1076 /* Find a page of the appropriate migrate type */
1078 list_for_each_entry_reverse(page, &pcp->list, lru)
1079 if (page_private(page) == migratetype)
1082 list_for_each_entry(page, &pcp->list, lru)
1083 if (page_private(page) == migratetype)
1087 /* Allocate more to the pcp list if necessary */
1088 if (unlikely(&page->lru == &pcp->list)) {
1089 pcp->count += rmqueue_bulk(zone, 0,
1090 pcp->batch, &pcp->list, migratetype);
1091 page = list_entry(pcp->list.next, struct page, lru);
1094 list_del(&page->lru);
1097 spin_lock_irqsave(&zone->lock, flags);
1098 page = __rmqueue(zone, order, migratetype);
1099 spin_unlock(&zone->lock);
1104 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1105 zone_statistics(preferred_zone, zone);
1106 local_irq_restore(flags);
1109 VM_BUG_ON(bad_range(zone, page));
1110 if (prep_new_page(page, order, gfp_flags))
1115 local_irq_restore(flags);
1120 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
1121 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
1122 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
1123 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
1124 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1125 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1126 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1128 #ifdef CONFIG_FAIL_PAGE_ALLOC
1130 static struct fail_page_alloc_attr {
1131 struct fault_attr attr;
1133 u32 ignore_gfp_highmem;
1134 u32 ignore_gfp_wait;
1137 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1139 struct dentry *ignore_gfp_highmem_file;
1140 struct dentry *ignore_gfp_wait_file;
1141 struct dentry *min_order_file;
1143 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1145 } fail_page_alloc = {
1146 .attr = FAULT_ATTR_INITIALIZER,
1147 .ignore_gfp_wait = 1,
1148 .ignore_gfp_highmem = 1,
1152 static int __init setup_fail_page_alloc(char *str)
1154 return setup_fault_attr(&fail_page_alloc.attr, str);
1156 __setup("fail_page_alloc=", setup_fail_page_alloc);
1158 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1160 if (order < fail_page_alloc.min_order)
1162 if (gfp_mask & __GFP_NOFAIL)
1164 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1166 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1169 return should_fail(&fail_page_alloc.attr, 1 << order);
1172 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1174 static int __init fail_page_alloc_debugfs(void)
1176 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1180 err = init_fault_attr_dentries(&fail_page_alloc.attr,
1184 dir = fail_page_alloc.attr.dentries.dir;
1186 fail_page_alloc.ignore_gfp_wait_file =
1187 debugfs_create_bool("ignore-gfp-wait", mode, dir,
1188 &fail_page_alloc.ignore_gfp_wait);
1190 fail_page_alloc.ignore_gfp_highmem_file =
1191 debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1192 &fail_page_alloc.ignore_gfp_highmem);
1193 fail_page_alloc.min_order_file =
1194 debugfs_create_u32("min-order", mode, dir,
1195 &fail_page_alloc.min_order);
1197 if (!fail_page_alloc.ignore_gfp_wait_file ||
1198 !fail_page_alloc.ignore_gfp_highmem_file ||
1199 !fail_page_alloc.min_order_file) {
1201 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
1202 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1203 debugfs_remove(fail_page_alloc.min_order_file);
1204 cleanup_fault_attr_dentries(&fail_page_alloc.attr);
1210 late_initcall(fail_page_alloc_debugfs);
1212 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1214 #else /* CONFIG_FAIL_PAGE_ALLOC */
1216 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1221 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1224 * Return 1 if free pages are above 'mark'. This takes into account the order
1225 * of the allocation.
1227 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1228 int classzone_idx, int alloc_flags)
1230 /* free_pages my go negative - that's OK */
1232 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
1235 if (alloc_flags & ALLOC_HIGH)
1237 if (alloc_flags & ALLOC_HARDER)
1240 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1242 for (o = 0; o < order; o++) {
1243 /* At the next order, this order's pages become unavailable */
1244 free_pages -= z->free_area[o].nr_free << o;
1246 /* Require fewer higher order pages to be free */
1249 if (free_pages <= min)
1257 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1258 * skip over zones that are not allowed by the cpuset, or that have
1259 * been recently (in last second) found to be nearly full. See further
1260 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1261 * that have to skip over a lot of full or unallowed zones.
1263 * If the zonelist cache is present in the passed in zonelist, then
1264 * returns a pointer to the allowed node mask (either the current
1265 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1267 * If the zonelist cache is not available for this zonelist, does
1268 * nothing and returns NULL.
1270 * If the fullzones BITMAP in the zonelist cache is stale (more than
1271 * a second since last zap'd) then we zap it out (clear its bits.)
1273 * We hold off even calling zlc_setup, until after we've checked the
1274 * first zone in the zonelist, on the theory that most allocations will
1275 * be satisfied from that first zone, so best to examine that zone as
1276 * quickly as we can.
1278 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1280 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1281 nodemask_t *allowednodes; /* zonelist_cache approximation */
1283 zlc = zonelist->zlcache_ptr;
1287 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1288 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1289 zlc->last_full_zap = jiffies;
1292 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1293 &cpuset_current_mems_allowed :
1294 &node_states[N_HIGH_MEMORY];
1295 return allowednodes;
1299 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1300 * if it is worth looking at further for free memory:
1301 * 1) Check that the zone isn't thought to be full (doesn't have its
1302 * bit set in the zonelist_cache fullzones BITMAP).
1303 * 2) Check that the zones node (obtained from the zonelist_cache
1304 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1305 * Return true (non-zero) if zone is worth looking at further, or
1306 * else return false (zero) if it is not.
1308 * This check -ignores- the distinction between various watermarks,
1309 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1310 * found to be full for any variation of these watermarks, it will
1311 * be considered full for up to one second by all requests, unless
1312 * we are so low on memory on all allowed nodes that we are forced
1313 * into the second scan of the zonelist.
1315 * In the second scan we ignore this zonelist cache and exactly
1316 * apply the watermarks to all zones, even it is slower to do so.
1317 * We are low on memory in the second scan, and should leave no stone
1318 * unturned looking for a free page.
1320 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1321 nodemask_t *allowednodes)
1323 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1324 int i; /* index of *z in zonelist zones */
1325 int n; /* node that zone *z is on */
1327 zlc = zonelist->zlcache_ptr;
1331 i = z - zonelist->_zonerefs;
1334 /* This zone is worth trying if it is allowed but not full */
1335 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1339 * Given 'z' scanning a zonelist, set the corresponding bit in
1340 * zlc->fullzones, so that subsequent attempts to allocate a page
1341 * from that zone don't waste time re-examining it.
1343 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1345 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1346 int i; /* index of *z in zonelist zones */
1348 zlc = zonelist->zlcache_ptr;
1352 i = z - zonelist->_zonerefs;
1354 set_bit(i, zlc->fullzones);
1357 #else /* CONFIG_NUMA */
1359 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1364 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1365 nodemask_t *allowednodes)
1370 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1373 #endif /* CONFIG_NUMA */
1376 * get_page_from_freelist goes through the zonelist trying to allocate
1379 static struct page *
1380 get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
1381 struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
1384 struct page *page = NULL;
1386 struct zone *zone, *preferred_zone;
1387 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1388 int zlc_active = 0; /* set if using zonelist_cache */
1389 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1391 z = first_zones_zonelist(zonelist, high_zoneidx);
1392 classzone_idx = zonelist_zone_idx(z);
1393 preferred_zone = zonelist_zone(z);
1397 * Scan zonelist, looking for a zone with enough free.
1398 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1400 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
1401 if (NUMA_BUILD && zlc_active &&
1402 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1404 if ((alloc_flags & ALLOC_CPUSET) &&
1405 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1408 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1410 if (alloc_flags & ALLOC_WMARK_MIN)
1411 mark = zone->pages_min;
1412 else if (alloc_flags & ALLOC_WMARK_LOW)
1413 mark = zone->pages_low;
1415 mark = zone->pages_high;
1416 if (!zone_watermark_ok(zone, order, mark,
1417 classzone_idx, alloc_flags)) {
1418 if (!zone_reclaim_mode ||
1419 !zone_reclaim(zone, gfp_mask, order))
1420 goto this_zone_full;
1424 page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask);
1429 zlc_mark_zone_full(zonelist, z);
1431 if (NUMA_BUILD && !did_zlc_setup) {
1432 /* we do zlc_setup after the first zone is tried */
1433 allowednodes = zlc_setup(zonelist, alloc_flags);
1439 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1440 /* Disable zlc cache for second zonelist scan */
1448 * This is the 'heart' of the zoned buddy allocator.
1451 __alloc_pages(gfp_t gfp_mask, unsigned int order,
1452 struct zonelist *zonelist)
1454 const gfp_t wait = gfp_mask & __GFP_WAIT;
1455 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1459 struct reclaim_state reclaim_state;
1460 struct task_struct *p = current;
1463 int did_some_progress;
1465 might_sleep_if(wait);
1467 if (should_fail_alloc_page(gfp_mask, order))
1471 z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */
1473 if (unlikely(!z->zone)) {
1475 * Happens if we have an empty zonelist as a result of
1476 * GFP_THISNODE being used on a memoryless node
1481 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1482 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
1487 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1488 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1489 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1490 * using a larger set of nodes after it has established that the
1491 * allowed per node queues are empty and that nodes are
1494 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
1497 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
1498 wakeup_kswapd(zone, order);
1501 * OK, we're below the kswapd watermark and have kicked background
1502 * reclaim. Now things get more complex, so set up alloc_flags according
1503 * to how we want to proceed.
1505 * The caller may dip into page reserves a bit more if the caller
1506 * cannot run direct reclaim, or if the caller has realtime scheduling
1507 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1508 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1510 alloc_flags = ALLOC_WMARK_MIN;
1511 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
1512 alloc_flags |= ALLOC_HARDER;
1513 if (gfp_mask & __GFP_HIGH)
1514 alloc_flags |= ALLOC_HIGH;
1516 alloc_flags |= ALLOC_CPUSET;
1519 * Go through the zonelist again. Let __GFP_HIGH and allocations
1520 * coming from realtime tasks go deeper into reserves.
1522 * This is the last chance, in general, before the goto nopage.
1523 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1524 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1526 page = get_page_from_freelist(gfp_mask, order, zonelist,
1527 high_zoneidx, alloc_flags);
1531 /* This allocation should allow future memory freeing. */
1534 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
1535 && !in_interrupt()) {
1536 if (!(gfp_mask & __GFP_NOMEMALLOC)) {
1538 /* go through the zonelist yet again, ignoring mins */
1539 page = get_page_from_freelist(gfp_mask, order,
1540 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
1543 if (gfp_mask & __GFP_NOFAIL) {
1544 congestion_wait(WRITE, HZ/50);
1551 /* Atomic allocations - we can't balance anything */
1557 /* We now go into synchronous reclaim */
1558 cpuset_memory_pressure_bump();
1559 p->flags |= PF_MEMALLOC;
1560 reclaim_state.reclaimed_slab = 0;
1561 p->reclaim_state = &reclaim_state;
1563 did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
1565 p->reclaim_state = NULL;
1566 p->flags &= ~PF_MEMALLOC;
1573 if (likely(did_some_progress)) {
1574 page = get_page_from_freelist(gfp_mask, order,
1575 zonelist, high_zoneidx, alloc_flags);
1578 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1579 if (!try_set_zone_oom(zonelist, gfp_mask)) {
1580 schedule_timeout_uninterruptible(1);
1585 * Go through the zonelist yet one more time, keep
1586 * very high watermark here, this is only to catch
1587 * a parallel oom killing, we must fail if we're still
1588 * under heavy pressure.
1590 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1591 zonelist, high_zoneidx, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1593 clear_zonelist_oom(zonelist, gfp_mask);
1597 /* The OOM killer will not help higher order allocs so fail */
1598 if (order > PAGE_ALLOC_COSTLY_ORDER) {
1599 clear_zonelist_oom(zonelist, gfp_mask);
1603 out_of_memory(zonelist, gfp_mask, order);
1604 clear_zonelist_oom(zonelist, gfp_mask);
1609 * Don't let big-order allocations loop unless the caller explicitly
1610 * requests that. Wait for some write requests to complete then retry.
1612 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1613 * <= 3, but that may not be true in other implementations.
1616 if (!(gfp_mask & __GFP_NORETRY)) {
1617 if ((order <= PAGE_ALLOC_COSTLY_ORDER) ||
1618 (gfp_mask & __GFP_REPEAT))
1620 if (gfp_mask & __GFP_NOFAIL)
1624 congestion_wait(WRITE, HZ/50);
1629 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
1630 printk(KERN_WARNING "%s: page allocation failure."
1631 " order:%d, mode:0x%x\n",
1632 p->comm, order, gfp_mask);
1640 EXPORT_SYMBOL(__alloc_pages);
1643 * Common helper functions.
1645 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
1648 page = alloc_pages(gfp_mask, order);
1651 return (unsigned long) page_address(page);
1654 EXPORT_SYMBOL(__get_free_pages);
1656 unsigned long get_zeroed_page(gfp_t gfp_mask)
1661 * get_zeroed_page() returns a 32-bit address, which cannot represent
1664 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
1666 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1668 return (unsigned long) page_address(page);
1672 EXPORT_SYMBOL(get_zeroed_page);
1674 void __pagevec_free(struct pagevec *pvec)
1676 int i = pagevec_count(pvec);
1679 free_hot_cold_page(pvec->pages[i], pvec->cold);
1682 void __free_pages(struct page *page, unsigned int order)
1684 if (put_page_testzero(page)) {
1686 free_hot_page(page);
1688 __free_pages_ok(page, order);
1692 EXPORT_SYMBOL(__free_pages);
1694 void free_pages(unsigned long addr, unsigned int order)
1697 VM_BUG_ON(!virt_addr_valid((void *)addr));
1698 __free_pages(virt_to_page((void *)addr), order);
1702 EXPORT_SYMBOL(free_pages);
1704 static unsigned int nr_free_zone_pages(int offset)
1709 /* Just pick one node, since fallback list is circular */
1710 unsigned int sum = 0;
1712 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
1714 for_each_zone_zonelist(zone, z, zonelist, offset) {
1715 unsigned long size = zone->present_pages;
1716 unsigned long high = zone->pages_high;
1725 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1727 unsigned int nr_free_buffer_pages(void)
1729 return nr_free_zone_pages(gfp_zone(GFP_USER));
1731 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
1734 * Amount of free RAM allocatable within all zones
1736 unsigned int nr_free_pagecache_pages(void)
1738 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
1741 static inline void show_node(struct zone *zone)
1744 printk("Node %d ", zone_to_nid(zone));
1747 void si_meminfo(struct sysinfo *val)
1749 val->totalram = totalram_pages;
1751 val->freeram = global_page_state(NR_FREE_PAGES);
1752 val->bufferram = nr_blockdev_pages();
1753 val->totalhigh = totalhigh_pages;
1754 val->freehigh = nr_free_highpages();
1755 val->mem_unit = PAGE_SIZE;
1758 EXPORT_SYMBOL(si_meminfo);
1761 void si_meminfo_node(struct sysinfo *val, int nid)
1763 pg_data_t *pgdat = NODE_DATA(nid);
1765 val->totalram = pgdat->node_present_pages;
1766 val->freeram = node_page_state(nid, NR_FREE_PAGES);
1767 #ifdef CONFIG_HIGHMEM
1768 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1769 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
1775 val->mem_unit = PAGE_SIZE;
1779 #define K(x) ((x) << (PAGE_SHIFT-10))
1782 * Show free area list (used inside shift_scroll-lock stuff)
1783 * We also calculate the percentage fragmentation. We do this by counting the
1784 * memory on each free list with the exception of the first item on the list.
1786 void show_free_areas(void)
1791 for_each_zone(zone) {
1792 if (!populated_zone(zone))
1796 printk("%s per-cpu:\n", zone->name);
1798 for_each_online_cpu(cpu) {
1799 struct per_cpu_pageset *pageset;
1801 pageset = zone_pcp(zone, cpu);
1803 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1804 cpu, pageset->pcp.high,
1805 pageset->pcp.batch, pageset->pcp.count);
1809 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1810 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1811 global_page_state(NR_ACTIVE),
1812 global_page_state(NR_INACTIVE),
1813 global_page_state(NR_FILE_DIRTY),
1814 global_page_state(NR_WRITEBACK),
1815 global_page_state(NR_UNSTABLE_NFS),
1816 global_page_state(NR_FREE_PAGES),
1817 global_page_state(NR_SLAB_RECLAIMABLE) +
1818 global_page_state(NR_SLAB_UNRECLAIMABLE),
1819 global_page_state(NR_FILE_MAPPED),
1820 global_page_state(NR_PAGETABLE),
1821 global_page_state(NR_BOUNCE));
1823 for_each_zone(zone) {
1826 if (!populated_zone(zone))
1838 " pages_scanned:%lu"
1839 " all_unreclaimable? %s"
1842 K(zone_page_state(zone, NR_FREE_PAGES)),
1845 K(zone->pages_high),
1846 K(zone_page_state(zone, NR_ACTIVE)),
1847 K(zone_page_state(zone, NR_INACTIVE)),
1848 K(zone->present_pages),
1849 zone->pages_scanned,
1850 (zone_is_all_unreclaimable(zone) ? "yes" : "no")
1852 printk("lowmem_reserve[]:");
1853 for (i = 0; i < MAX_NR_ZONES; i++)
1854 printk(" %lu", zone->lowmem_reserve[i]);
1858 for_each_zone(zone) {
1859 unsigned long nr[MAX_ORDER], flags, order, total = 0;
1861 if (!populated_zone(zone))
1865 printk("%s: ", zone->name);
1867 spin_lock_irqsave(&zone->lock, flags);
1868 for (order = 0; order < MAX_ORDER; order++) {
1869 nr[order] = zone->free_area[order].nr_free;
1870 total += nr[order] << order;
1872 spin_unlock_irqrestore(&zone->lock, flags);
1873 for (order = 0; order < MAX_ORDER; order++)
1874 printk("%lu*%lukB ", nr[order], K(1UL) << order);
1875 printk("= %lukB\n", K(total));
1878 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
1880 show_swap_cache_info();
1884 * Builds allocation fallback zone lists.
1886 * Add all populated zones of a node to the zonelist.
1888 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
1889 int nr_zones, enum zone_type zone_type)
1893 BUG_ON(zone_type >= MAX_NR_ZONES);
1898 zone = pgdat->node_zones + zone_type;
1899 if (populated_zone(zone)) {
1900 zoneref_set_zone(zone,
1901 &zonelist->_zonerefs[nr_zones++]);
1902 check_highest_zone(zone_type);
1905 } while (zone_type);
1912 * 0 = automatic detection of better ordering.
1913 * 1 = order by ([node] distance, -zonetype)
1914 * 2 = order by (-zonetype, [node] distance)
1916 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
1917 * the same zonelist. So only NUMA can configure this param.
1919 #define ZONELIST_ORDER_DEFAULT 0
1920 #define ZONELIST_ORDER_NODE 1
1921 #define ZONELIST_ORDER_ZONE 2
1923 /* zonelist order in the kernel.
1924 * set_zonelist_order() will set this to NODE or ZONE.
1926 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
1927 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
1931 /* The value user specified ....changed by config */
1932 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
1933 /* string for sysctl */
1934 #define NUMA_ZONELIST_ORDER_LEN 16
1935 char numa_zonelist_order[16] = "default";
1938 * interface for configure zonelist ordering.
1939 * command line option "numa_zonelist_order"
1940 * = "[dD]efault - default, automatic configuration.
1941 * = "[nN]ode - order by node locality, then by zone within node
1942 * = "[zZ]one - order by zone, then by locality within zone
1945 static int __parse_numa_zonelist_order(char *s)
1947 if (*s == 'd' || *s == 'D') {
1948 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
1949 } else if (*s == 'n' || *s == 'N') {
1950 user_zonelist_order = ZONELIST_ORDER_NODE;
1951 } else if (*s == 'z' || *s == 'Z') {
1952 user_zonelist_order = ZONELIST_ORDER_ZONE;
1955 "Ignoring invalid numa_zonelist_order value: "
1962 static __init int setup_numa_zonelist_order(char *s)
1965 return __parse_numa_zonelist_order(s);
1968 early_param("numa_zonelist_order", setup_numa_zonelist_order);
1971 * sysctl handler for numa_zonelist_order
1973 int numa_zonelist_order_handler(ctl_table *table, int write,
1974 struct file *file, void __user *buffer, size_t *length,
1977 char saved_string[NUMA_ZONELIST_ORDER_LEN];
1981 strncpy(saved_string, (char*)table->data,
1982 NUMA_ZONELIST_ORDER_LEN);
1983 ret = proc_dostring(table, write, file, buffer, length, ppos);
1987 int oldval = user_zonelist_order;
1988 if (__parse_numa_zonelist_order((char*)table->data)) {
1990 * bogus value. restore saved string
1992 strncpy((char*)table->data, saved_string,
1993 NUMA_ZONELIST_ORDER_LEN);
1994 user_zonelist_order = oldval;
1995 } else if (oldval != user_zonelist_order)
1996 build_all_zonelists();
2002 #define MAX_NODE_LOAD (num_online_nodes())
2003 static int node_load[MAX_NUMNODES];
2006 * find_next_best_node - find the next node that should appear in a given node's fallback list
2007 * @node: node whose fallback list we're appending
2008 * @used_node_mask: nodemask_t of already used nodes
2010 * We use a number of factors to determine which is the next node that should
2011 * appear on a given node's fallback list. The node should not have appeared
2012 * already in @node's fallback list, and it should be the next closest node
2013 * according to the distance array (which contains arbitrary distance values
2014 * from each node to each node in the system), and should also prefer nodes
2015 * with no CPUs, since presumably they'll have very little allocation pressure
2016 * on them otherwise.
2017 * It returns -1 if no node is found.
2019 static int find_next_best_node(int node, nodemask_t *used_node_mask)
2022 int min_val = INT_MAX;
2024 node_to_cpumask_ptr(tmp, 0);
2026 /* Use the local node if we haven't already */
2027 if (!node_isset(node, *used_node_mask)) {
2028 node_set(node, *used_node_mask);
2032 for_each_node_state(n, N_HIGH_MEMORY) {
2034 /* Don't want a node to appear more than once */
2035 if (node_isset(n, *used_node_mask))
2038 /* Use the distance array to find the distance */
2039 val = node_distance(node, n);
2041 /* Penalize nodes under us ("prefer the next node") */
2044 /* Give preference to headless and unused nodes */
2045 node_to_cpumask_ptr_next(tmp, n);
2046 if (!cpus_empty(*tmp))
2047 val += PENALTY_FOR_NODE_WITH_CPUS;
2049 /* Slight preference for less loaded node */
2050 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2051 val += node_load[n];
2053 if (val < min_val) {
2060 node_set(best_node, *used_node_mask);
2067 * Build zonelists ordered by node and zones within node.
2068 * This results in maximum locality--normal zone overflows into local
2069 * DMA zone, if any--but risks exhausting DMA zone.
2071 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2074 struct zonelist *zonelist;
2076 zonelist = &pgdat->node_zonelists[0];
2077 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2079 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2081 zonelist->_zonerefs[j].zone = NULL;
2082 zonelist->_zonerefs[j].zone_idx = 0;
2086 * Build gfp_thisnode zonelists
2088 static void build_thisnode_zonelists(pg_data_t *pgdat)
2091 struct zonelist *zonelist;
2093 zonelist = &pgdat->node_zonelists[1];
2094 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2095 zonelist->_zonerefs[j].zone = NULL;
2096 zonelist->_zonerefs[j].zone_idx = 0;
2100 * Build zonelists ordered by zone and nodes within zones.
2101 * This results in conserving DMA zone[s] until all Normal memory is
2102 * exhausted, but results in overflowing to remote node while memory
2103 * may still exist in local DMA zone.
2105 static int node_order[MAX_NUMNODES];
2107 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2110 int zone_type; /* needs to be signed */
2112 struct zonelist *zonelist;
2114 zonelist = &pgdat->node_zonelists[0];
2116 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
2117 for (j = 0; j < nr_nodes; j++) {
2118 node = node_order[j];
2119 z = &NODE_DATA(node)->node_zones[zone_type];
2120 if (populated_zone(z)) {
2122 &zonelist->_zonerefs[pos++]);
2123 check_highest_zone(zone_type);
2127 zonelist->_zonerefs[pos].zone = NULL;
2128 zonelist->_zonerefs[pos].zone_idx = 0;
2131 static int default_zonelist_order(void)
2134 unsigned long low_kmem_size,total_size;
2138 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2139 * If they are really small and used heavily, the system can fall
2140 * into OOM very easily.
2141 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2143 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2146 for_each_online_node(nid) {
2147 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2148 z = &NODE_DATA(nid)->node_zones[zone_type];
2149 if (populated_zone(z)) {
2150 if (zone_type < ZONE_NORMAL)
2151 low_kmem_size += z->present_pages;
2152 total_size += z->present_pages;
2156 if (!low_kmem_size || /* there are no DMA area. */
2157 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
2158 return ZONELIST_ORDER_NODE;
2160 * look into each node's config.
2161 * If there is a node whose DMA/DMA32 memory is very big area on
2162 * local memory, NODE_ORDER may be suitable.
2164 average_size = total_size /
2165 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2166 for_each_online_node(nid) {
2169 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2170 z = &NODE_DATA(nid)->node_zones[zone_type];
2171 if (populated_zone(z)) {
2172 if (zone_type < ZONE_NORMAL)
2173 low_kmem_size += z->present_pages;
2174 total_size += z->present_pages;
2177 if (low_kmem_size &&
2178 total_size > average_size && /* ignore small node */
2179 low_kmem_size > total_size * 70/100)
2180 return ZONELIST_ORDER_NODE;
2182 return ZONELIST_ORDER_ZONE;
2185 static void set_zonelist_order(void)
2187 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
2188 current_zonelist_order = default_zonelist_order();
2190 current_zonelist_order = user_zonelist_order;
2193 static void build_zonelists(pg_data_t *pgdat)
2197 nodemask_t used_mask;
2198 int local_node, prev_node;
2199 struct zonelist *zonelist;
2200 int order = current_zonelist_order;
2202 /* initialize zonelists */
2203 for (i = 0; i < MAX_ZONELISTS; i++) {
2204 zonelist = pgdat->node_zonelists + i;
2205 zonelist->_zonerefs[0].zone = NULL;
2206 zonelist->_zonerefs[0].zone_idx = 0;
2209 /* NUMA-aware ordering of nodes */
2210 local_node = pgdat->node_id;
2211 load = num_online_nodes();
2212 prev_node = local_node;
2213 nodes_clear(used_mask);
2215 memset(node_load, 0, sizeof(node_load));
2216 memset(node_order, 0, sizeof(node_order));
2219 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2220 int distance = node_distance(local_node, node);
2223 * If another node is sufficiently far away then it is better
2224 * to reclaim pages in a zone before going off node.
2226 if (distance > RECLAIM_DISTANCE)
2227 zone_reclaim_mode = 1;
2230 * We don't want to pressure a particular node.
2231 * So adding penalty to the first node in same
2232 * distance group to make it round-robin.
2234 if (distance != node_distance(local_node, prev_node))
2235 node_load[node] = load;
2239 if (order == ZONELIST_ORDER_NODE)
2240 build_zonelists_in_node_order(pgdat, node);
2242 node_order[j++] = node; /* remember order */
2245 if (order == ZONELIST_ORDER_ZONE) {
2246 /* calculate node order -- i.e., DMA last! */
2247 build_zonelists_in_zone_order(pgdat, j);
2250 build_thisnode_zonelists(pgdat);
2253 /* Construct the zonelist performance cache - see further mmzone.h */
2254 static void build_zonelist_cache(pg_data_t *pgdat)
2256 struct zonelist *zonelist;
2257 struct zonelist_cache *zlc;
2260 zonelist = &pgdat->node_zonelists[0];
2261 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
2262 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2263 for (z = zonelist->_zonerefs; z->zone; z++)
2264 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2268 #else /* CONFIG_NUMA */
2270 static void set_zonelist_order(void)
2272 current_zonelist_order = ZONELIST_ORDER_ZONE;
2275 static void build_zonelists(pg_data_t *pgdat)
2277 int node, local_node;
2279 struct zonelist *zonelist;
2281 local_node = pgdat->node_id;
2283 zonelist = &pgdat->node_zonelists[0];
2284 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2287 * Now we build the zonelist so that it contains the zones
2288 * of all the other nodes.
2289 * We don't want to pressure a particular node, so when
2290 * building the zones for node N, we make sure that the
2291 * zones coming right after the local ones are those from
2292 * node N+1 (modulo N)
2294 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
2295 if (!node_online(node))
2297 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2300 for (node = 0; node < local_node; node++) {
2301 if (!node_online(node))
2303 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2307 zonelist->_zonerefs[j].zone = NULL;
2308 zonelist->_zonerefs[j].zone_idx = 0;
2311 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2312 static void build_zonelist_cache(pg_data_t *pgdat)
2314 pgdat->node_zonelists[0].zlcache_ptr = NULL;
2315 pgdat->node_zonelists[1].zlcache_ptr = NULL;
2318 #endif /* CONFIG_NUMA */
2320 /* return values int ....just for stop_machine_run() */
2321 static int __build_all_zonelists(void *dummy)
2325 for_each_online_node(nid) {
2326 pg_data_t *pgdat = NODE_DATA(nid);
2328 build_zonelists(pgdat);
2329 build_zonelist_cache(pgdat);
2334 void build_all_zonelists(void)
2336 set_zonelist_order();
2338 if (system_state == SYSTEM_BOOTING) {
2339 __build_all_zonelists(NULL);
2340 cpuset_init_current_mems_allowed();
2342 /* we have to stop all cpus to guarantee there is no user
2344 stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
2345 /* cpuset refresh routine should be here */
2347 vm_total_pages = nr_free_pagecache_pages();
2349 * Disable grouping by mobility if the number of pages in the
2350 * system is too low to allow the mechanism to work. It would be
2351 * more accurate, but expensive to check per-zone. This check is
2352 * made on memory-hotadd so a system can start with mobility
2353 * disabled and enable it later
2355 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2356 page_group_by_mobility_disabled = 1;
2358 page_group_by_mobility_disabled = 0;
2360 printk("Built %i zonelists in %s order, mobility grouping %s. "
2361 "Total pages: %ld\n",
2363 zonelist_order_name[current_zonelist_order],
2364 page_group_by_mobility_disabled ? "off" : "on",
2367 printk("Policy zone: %s\n", zone_names[policy_zone]);
2372 * Helper functions to size the waitqueue hash table.
2373 * Essentially these want to choose hash table sizes sufficiently
2374 * large so that collisions trying to wait on pages are rare.
2375 * But in fact, the number of active page waitqueues on typical
2376 * systems is ridiculously low, less than 200. So this is even
2377 * conservative, even though it seems large.
2379 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2380 * waitqueues, i.e. the size of the waitq table given the number of pages.
2382 #define PAGES_PER_WAITQUEUE 256
2384 #ifndef CONFIG_MEMORY_HOTPLUG
2385 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2387 unsigned long size = 1;
2389 pages /= PAGES_PER_WAITQUEUE;
2391 while (size < pages)
2395 * Once we have dozens or even hundreds of threads sleeping
2396 * on IO we've got bigger problems than wait queue collision.
2397 * Limit the size of the wait table to a reasonable size.
2399 size = min(size, 4096UL);
2401 return max(size, 4UL);
2405 * A zone's size might be changed by hot-add, so it is not possible to determine
2406 * a suitable size for its wait_table. So we use the maximum size now.
2408 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2410 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2411 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2412 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2414 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2415 * or more by the traditional way. (See above). It equals:
2417 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2418 * ia64(16K page size) : = ( 8G + 4M)byte.
2419 * powerpc (64K page size) : = (32G +16M)byte.
2421 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2428 * This is an integer logarithm so that shifts can be used later
2429 * to extract the more random high bits from the multiplicative
2430 * hash function before the remainder is taken.
2432 static inline unsigned long wait_table_bits(unsigned long size)
2437 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2440 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2441 * of blocks reserved is based on zone->pages_min. The memory within the
2442 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2443 * higher will lead to a bigger reserve which will get freed as contiguous
2444 * blocks as reclaim kicks in
2446 static void setup_zone_migrate_reserve(struct zone *zone)
2448 unsigned long start_pfn, pfn, end_pfn;
2450 unsigned long reserve, block_migratetype;
2452 /* Get the start pfn, end pfn and the number of blocks to reserve */
2453 start_pfn = zone->zone_start_pfn;
2454 end_pfn = start_pfn + zone->spanned_pages;
2455 reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
2458 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2459 if (!pfn_valid(pfn))
2461 page = pfn_to_page(pfn);
2463 /* Blocks with reserved pages will never free, skip them. */
2464 if (PageReserved(page))
2467 block_migratetype = get_pageblock_migratetype(page);
2469 /* If this block is reserved, account for it */
2470 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
2475 /* Suitable for reserving if this block is movable */
2476 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
2477 set_pageblock_migratetype(page, MIGRATE_RESERVE);
2478 move_freepages_block(zone, page, MIGRATE_RESERVE);
2484 * If the reserve is met and this is a previous reserved block,
2487 if (block_migratetype == MIGRATE_RESERVE) {
2488 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2489 move_freepages_block(zone, page, MIGRATE_MOVABLE);
2495 * Initially all pages are reserved - free ones are freed
2496 * up by free_all_bootmem() once the early boot process is
2497 * done. Non-atomic initialization, single-pass.
2499 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
2500 unsigned long start_pfn, enum memmap_context context)
2503 unsigned long end_pfn = start_pfn + size;
2506 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
2508 * There can be holes in boot-time mem_map[]s
2509 * handed to this function. They do not
2510 * exist on hotplugged memory.
2512 if (context == MEMMAP_EARLY) {
2513 if (!early_pfn_valid(pfn))
2515 if (!early_pfn_in_nid(pfn, nid))
2518 page = pfn_to_page(pfn);
2519 set_page_links(page, zone, nid, pfn);
2520 init_page_count(page);
2521 reset_page_mapcount(page);
2522 SetPageReserved(page);
2525 * Mark the block movable so that blocks are reserved for
2526 * movable at startup. This will force kernel allocations
2527 * to reserve their blocks rather than leaking throughout
2528 * the address space during boot when many long-lived
2529 * kernel allocations are made. Later some blocks near
2530 * the start are marked MIGRATE_RESERVE by
2531 * setup_zone_migrate_reserve()
2533 if ((pfn & (pageblock_nr_pages-1)))
2534 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2536 INIT_LIST_HEAD(&page->lru);
2537 #ifdef WANT_PAGE_VIRTUAL
2538 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2539 if (!is_highmem_idx(zone))
2540 set_page_address(page, __va(pfn << PAGE_SHIFT));
2545 static void __meminit zone_init_free_lists(struct zone *zone)
2548 for_each_migratetype_order(order, t) {
2549 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
2550 zone->free_area[order].nr_free = 0;
2554 #ifndef __HAVE_ARCH_MEMMAP_INIT
2555 #define memmap_init(size, nid, zone, start_pfn) \
2556 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2559 static int zone_batchsize(struct zone *zone)
2564 * The per-cpu-pages pools are set to around 1000th of the
2565 * size of the zone. But no more than 1/2 of a meg.
2567 * OK, so we don't know how big the cache is. So guess.
2569 batch = zone->present_pages / 1024;
2570 if (batch * PAGE_SIZE > 512 * 1024)
2571 batch = (512 * 1024) / PAGE_SIZE;
2572 batch /= 4; /* We effectively *= 4 below */
2577 * Clamp the batch to a 2^n - 1 value. Having a power
2578 * of 2 value was found to be more likely to have
2579 * suboptimal cache aliasing properties in some cases.
2581 * For example if 2 tasks are alternately allocating
2582 * batches of pages, one task can end up with a lot
2583 * of pages of one half of the possible page colors
2584 * and the other with pages of the other colors.
2586 batch = (1 << (fls(batch + batch/2)-1)) - 1;
2591 inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2593 struct per_cpu_pages *pcp;
2595 memset(p, 0, sizeof(*p));
2599 pcp->high = 6 * batch;
2600 pcp->batch = max(1UL, 1 * batch);
2601 INIT_LIST_HEAD(&pcp->list);
2605 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2606 * to the value high for the pageset p.
2609 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
2612 struct per_cpu_pages *pcp;
2616 pcp->batch = max(1UL, high/4);
2617 if ((high/4) > (PAGE_SHIFT * 8))
2618 pcp->batch = PAGE_SHIFT * 8;
2624 * Boot pageset table. One per cpu which is going to be used for all
2625 * zones and all nodes. The parameters will be set in such a way
2626 * that an item put on a list will immediately be handed over to
2627 * the buddy list. This is safe since pageset manipulation is done
2628 * with interrupts disabled.
2630 * Some NUMA counter updates may also be caught by the boot pagesets.
2632 * The boot_pagesets must be kept even after bootup is complete for
2633 * unused processors and/or zones. They do play a role for bootstrapping
2634 * hotplugged processors.
2636 * zoneinfo_show() and maybe other functions do
2637 * not check if the processor is online before following the pageset pointer.
2638 * Other parts of the kernel may not check if the zone is available.
2640 static struct per_cpu_pageset boot_pageset[NR_CPUS];
2643 * Dynamically allocate memory for the
2644 * per cpu pageset array in struct zone.
2646 static int __cpuinit process_zones(int cpu)
2648 struct zone *zone, *dzone;
2649 int node = cpu_to_node(cpu);
2651 node_set_state(node, N_CPU); /* this node has a cpu */
2653 for_each_zone(zone) {
2655 if (!populated_zone(zone))
2658 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2660 if (!zone_pcp(zone, cpu))
2663 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2665 if (percpu_pagelist_fraction)
2666 setup_pagelist_highmark(zone_pcp(zone, cpu),
2667 (zone->present_pages / percpu_pagelist_fraction));
2672 for_each_zone(dzone) {
2673 if (!populated_zone(dzone))
2677 kfree(zone_pcp(dzone, cpu));
2678 zone_pcp(dzone, cpu) = NULL;
2683 static inline void free_zone_pagesets(int cpu)
2687 for_each_zone(zone) {
2688 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
2690 /* Free per_cpu_pageset if it is slab allocated */
2691 if (pset != &boot_pageset[cpu])
2693 zone_pcp(zone, cpu) = NULL;
2697 static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2698 unsigned long action,
2701 int cpu = (long)hcpu;
2702 int ret = NOTIFY_OK;
2705 case CPU_UP_PREPARE:
2706 case CPU_UP_PREPARE_FROZEN:
2707 if (process_zones(cpu))
2710 case CPU_UP_CANCELED:
2711 case CPU_UP_CANCELED_FROZEN:
2713 case CPU_DEAD_FROZEN:
2714 free_zone_pagesets(cpu);
2722 static struct notifier_block __cpuinitdata pageset_notifier =
2723 { &pageset_cpuup_callback, NULL, 0 };
2725 void __init setup_per_cpu_pageset(void)
2729 /* Initialize per_cpu_pageset for cpu 0.
2730 * A cpuup callback will do this for every cpu
2731 * as it comes online
2733 err = process_zones(smp_processor_id());
2735 register_cpu_notifier(&pageset_notifier);
2740 static noinline __init_refok
2741 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2744 struct pglist_data *pgdat = zone->zone_pgdat;
2748 * The per-page waitqueue mechanism uses hashed waitqueues
2751 zone->wait_table_hash_nr_entries =
2752 wait_table_hash_nr_entries(zone_size_pages);
2753 zone->wait_table_bits =
2754 wait_table_bits(zone->wait_table_hash_nr_entries);
2755 alloc_size = zone->wait_table_hash_nr_entries
2756 * sizeof(wait_queue_head_t);
2758 if (system_state == SYSTEM_BOOTING) {
2759 zone->wait_table = (wait_queue_head_t *)
2760 alloc_bootmem_node(pgdat, alloc_size);
2763 * This case means that a zone whose size was 0 gets new memory
2764 * via memory hot-add.
2765 * But it may be the case that a new node was hot-added. In
2766 * this case vmalloc() will not be able to use this new node's
2767 * memory - this wait_table must be initialized to use this new
2768 * node itself as well.
2769 * To use this new node's memory, further consideration will be
2772 zone->wait_table = vmalloc(alloc_size);
2774 if (!zone->wait_table)
2777 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2778 init_waitqueue_head(zone->wait_table + i);
2783 static __meminit void zone_pcp_init(struct zone *zone)
2786 unsigned long batch = zone_batchsize(zone);
2788 for (cpu = 0; cpu < NR_CPUS; cpu++) {
2790 /* Early boot. Slab allocator not functional yet */
2791 zone_pcp(zone, cpu) = &boot_pageset[cpu];
2792 setup_pageset(&boot_pageset[cpu],0);
2794 setup_pageset(zone_pcp(zone,cpu), batch);
2797 if (zone->present_pages)
2798 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
2799 zone->name, zone->present_pages, batch);
2802 __meminit int init_currently_empty_zone(struct zone *zone,
2803 unsigned long zone_start_pfn,
2805 enum memmap_context context)
2807 struct pglist_data *pgdat = zone->zone_pgdat;
2809 ret = zone_wait_table_init(zone, size);
2812 pgdat->nr_zones = zone_idx(zone) + 1;
2814 zone->zone_start_pfn = zone_start_pfn;
2816 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);
2818 zone_init_free_lists(zone);
2823 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2825 * Basic iterator support. Return the first range of PFNs for a node
2826 * Note: nid == MAX_NUMNODES returns first region regardless of node
2828 static int __meminit first_active_region_index_in_nid(int nid)
2832 for (i = 0; i < nr_nodemap_entries; i++)
2833 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
2840 * Basic iterator support. Return the next active range of PFNs for a node
2841 * Note: nid == MAX_NUMNODES returns next region regardless of node
2843 static int __meminit next_active_region_index_in_nid(int index, int nid)
2845 for (index = index + 1; index < nr_nodemap_entries; index++)
2846 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
2852 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2854 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2855 * Architectures may implement their own version but if add_active_range()
2856 * was used and there are no special requirements, this is a convenient
2859 int __meminit early_pfn_to_nid(unsigned long pfn)
2863 for (i = 0; i < nr_nodemap_entries; i++) {
2864 unsigned long start_pfn = early_node_map[i].start_pfn;
2865 unsigned long end_pfn = early_node_map[i].end_pfn;
2867 if (start_pfn <= pfn && pfn < end_pfn)
2868 return early_node_map[i].nid;
2873 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2875 /* Basic iterator support to walk early_node_map[] */
2876 #define for_each_active_range_index_in_nid(i, nid) \
2877 for (i = first_active_region_index_in_nid(nid); i != -1; \
2878 i = next_active_region_index_in_nid(i, nid))
2881 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2882 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2883 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2885 * If an architecture guarantees that all ranges registered with
2886 * add_active_ranges() contain no holes and may be freed, this
2887 * this function may be used instead of calling free_bootmem() manually.
2889 void __init free_bootmem_with_active_regions(int nid,
2890 unsigned long max_low_pfn)
2894 for_each_active_range_index_in_nid(i, nid) {
2895 unsigned long size_pages = 0;
2896 unsigned long end_pfn = early_node_map[i].end_pfn;
2898 if (early_node_map[i].start_pfn >= max_low_pfn)
2901 if (end_pfn > max_low_pfn)
2902 end_pfn = max_low_pfn;
2904 size_pages = end_pfn - early_node_map[i].start_pfn;
2905 free_bootmem_node(NODE_DATA(early_node_map[i].nid),
2906 PFN_PHYS(early_node_map[i].start_pfn),
2907 size_pages << PAGE_SHIFT);
2912 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2913 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2915 * If an architecture guarantees that all ranges registered with
2916 * add_active_ranges() contain no holes and may be freed, this
2917 * function may be used instead of calling memory_present() manually.
2919 void __init sparse_memory_present_with_active_regions(int nid)
2923 for_each_active_range_index_in_nid(i, nid)
2924 memory_present(early_node_map[i].nid,
2925 early_node_map[i].start_pfn,
2926 early_node_map[i].end_pfn);
2930 * push_node_boundaries - Push node boundaries to at least the requested boundary
2931 * @nid: The nid of the node to push the boundary for
2932 * @start_pfn: The start pfn of the node
2933 * @end_pfn: The end pfn of the node
2935 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2936 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2937 * be hotplugged even though no physical memory exists. This function allows
2938 * an arch to push out the node boundaries so mem_map is allocated that can
2941 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2942 void __init push_node_boundaries(unsigned int nid,
2943 unsigned long start_pfn, unsigned long end_pfn)
2945 printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
2946 nid, start_pfn, end_pfn);
2948 /* Initialise the boundary for this node if necessary */
2949 if (node_boundary_end_pfn[nid] == 0)
2950 node_boundary_start_pfn[nid] = -1UL;
2952 /* Update the boundaries */
2953 if (node_boundary_start_pfn[nid] > start_pfn)
2954 node_boundary_start_pfn[nid] = start_pfn;
2955 if (node_boundary_end_pfn[nid] < end_pfn)
2956 node_boundary_end_pfn[nid] = end_pfn;
2959 /* If necessary, push the node boundary out for reserve hotadd */
2960 static void __meminit account_node_boundary(unsigned int nid,
2961 unsigned long *start_pfn, unsigned long *end_pfn)
2963 printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
2964 nid, *start_pfn, *end_pfn);
2966 /* Return if boundary information has not been provided */
2967 if (node_boundary_end_pfn[nid] == 0)
2970 /* Check the boundaries and update if necessary */
2971 if (node_boundary_start_pfn[nid] < *start_pfn)
2972 *start_pfn = node_boundary_start_pfn[nid];
2973 if (node_boundary_end_pfn[nid] > *end_pfn)
2974 *end_pfn = node_boundary_end_pfn[nid];
2977 void __init push_node_boundaries(unsigned int nid,
2978 unsigned long start_pfn, unsigned long end_pfn) {}
2980 static void __meminit account_node_boundary(unsigned int nid,
2981 unsigned long *start_pfn, unsigned long *end_pfn) {}
2986 * get_pfn_range_for_nid - Return the start and end page frames for a node
2987 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
2988 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
2989 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
2991 * It returns the start and end page frame of a node based on information
2992 * provided by an arch calling add_active_range(). If called for a node
2993 * with no available memory, a warning is printed and the start and end
2996 void __meminit get_pfn_range_for_nid(unsigned int nid,
2997 unsigned long *start_pfn, unsigned long *end_pfn)
3003 for_each_active_range_index_in_nid(i, nid) {
3004 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
3005 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
3008 if (*start_pfn == -1UL)
3011 /* Push the node boundaries out if requested */
3012 account_node_boundary(nid, start_pfn, end_pfn);
3016 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3017 * assumption is made that zones within a node are ordered in monotonic
3018 * increasing memory addresses so that the "highest" populated zone is used
3020 void __init find_usable_zone_for_movable(void)
3023 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
3024 if (zone_index == ZONE_MOVABLE)
3027 if (arch_zone_highest_possible_pfn[zone_index] >
3028 arch_zone_lowest_possible_pfn[zone_index])
3032 VM_BUG_ON(zone_index == -1);
3033 movable_zone = zone_index;
3037 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3038 * because it is sized independant of architecture. Unlike the other zones,
3039 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3040 * in each node depending on the size of each node and how evenly kernelcore
3041 * is distributed. This helper function adjusts the zone ranges
3042 * provided by the architecture for a given node by using the end of the
3043 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3044 * zones within a node are in order of monotonic increases memory addresses
3046 void __meminit adjust_zone_range_for_zone_movable(int nid,
3047 unsigned long zone_type,
3048 unsigned long node_start_pfn,
3049 unsigned long node_end_pfn,
3050 unsigned long *zone_start_pfn,
3051 unsigned long *zone_end_pfn)
3053 /* Only adjust if ZONE_MOVABLE is on this node */
3054 if (zone_movable_pfn[nid]) {
3055 /* Size ZONE_MOVABLE */
3056 if (zone_type == ZONE_MOVABLE) {
3057 *zone_start_pfn = zone_movable_pfn[nid];
3058 *zone_end_pfn = min(node_end_pfn,
3059 arch_zone_highest_possible_pfn[movable_zone]);
3061 /* Adjust for ZONE_MOVABLE starting within this range */
3062 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
3063 *zone_end_pfn > zone_movable_pfn[nid]) {
3064 *zone_end_pfn = zone_movable_pfn[nid];
3066 /* Check if this whole range is within ZONE_MOVABLE */
3067 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
3068 *zone_start_pfn = *zone_end_pfn;
3073 * Return the number of pages a zone spans in a node, including holes
3074 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3076 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3077 unsigned long zone_type,
3078 unsigned long *ignored)
3080 unsigned long node_start_pfn, node_end_pfn;
3081 unsigned long zone_start_pfn, zone_end_pfn;
3083 /* Get the start and end of the node and zone */
3084 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3085 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
3086 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
3087 adjust_zone_range_for_zone_movable(nid, zone_type,
3088 node_start_pfn, node_end_pfn,
3089 &zone_start_pfn, &zone_end_pfn);
3091 /* Check that this node has pages within the zone's required range */
3092 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
3095 /* Move the zone boundaries inside the node if necessary */
3096 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
3097 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
3099 /* Return the spanned pages */
3100 return zone_end_pfn - zone_start_pfn;
3104 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3105 * then all holes in the requested range will be accounted for.
3107 unsigned long __meminit __absent_pages_in_range(int nid,
3108 unsigned long range_start_pfn,
3109 unsigned long range_end_pfn)
3112 unsigned long prev_end_pfn = 0, hole_pages = 0;
3113 unsigned long start_pfn;
3115 /* Find the end_pfn of the first active range of pfns in the node */
3116 i = first_active_region_index_in_nid(nid);
3120 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3122 /* Account for ranges before physical memory on this node */
3123 if (early_node_map[i].start_pfn > range_start_pfn)
3124 hole_pages = prev_end_pfn - range_start_pfn;
3126 /* Find all holes for the zone within the node */
3127 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
3129 /* No need to continue if prev_end_pfn is outside the zone */
3130 if (prev_end_pfn >= range_end_pfn)
3133 /* Make sure the end of the zone is not within the hole */
3134 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3135 prev_end_pfn = max(prev_end_pfn, range_start_pfn);
3137 /* Update the hole size cound and move on */
3138 if (start_pfn > range_start_pfn) {
3139 BUG_ON(prev_end_pfn > start_pfn);
3140 hole_pages += start_pfn - prev_end_pfn;
3142 prev_end_pfn = early_node_map[i].end_pfn;
3145 /* Account for ranges past physical memory on this node */
3146 if (range_end_pfn > prev_end_pfn)
3147 hole_pages += range_end_pfn -
3148 max(range_start_pfn, prev_end_pfn);
3154 * absent_pages_in_range - Return number of page frames in holes within a range
3155 * @start_pfn: The start PFN to start searching for holes
3156 * @end_pfn: The end PFN to stop searching for holes
3158 * It returns the number of pages frames in memory holes within a range.
3160 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
3161 unsigned long end_pfn)
3163 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
3166 /* Return the number of page frames in holes in a zone on a node */
3167 static unsigned long __meminit zone_absent_pages_in_node(int nid,
3168 unsigned long zone_type,
3169 unsigned long *ignored)
3171 unsigned long node_start_pfn, node_end_pfn;
3172 unsigned long zone_start_pfn, zone_end_pfn;
3174 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3175 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
3177 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
3180 adjust_zone_range_for_zone_movable(nid, zone_type,
3181 node_start_pfn, node_end_pfn,
3182 &zone_start_pfn, &zone_end_pfn);
3183 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3187 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3188 unsigned long zone_type,
3189 unsigned long *zones_size)
3191 return zones_size[zone_type];
3194 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3195 unsigned long zone_type,
3196 unsigned long *zholes_size)
3201 return zholes_size[zone_type];
3206 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3207 unsigned long *zones_size, unsigned long *zholes_size)
3209 unsigned long realtotalpages, totalpages = 0;
3212 for (i = 0; i < MAX_NR_ZONES; i++)
3213 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
3215 pgdat->node_spanned_pages = totalpages;
3217 realtotalpages = totalpages;
3218 for (i = 0; i < MAX_NR_ZONES; i++)
3220 zone_absent_pages_in_node(pgdat->node_id, i,
3222 pgdat->node_present_pages = realtotalpages;
3223 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
3227 #ifndef CONFIG_SPARSEMEM
3229 * Calculate the size of the zone->blockflags rounded to an unsigned long
3230 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3231 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3232 * round what is now in bits to nearest long in bits, then return it in
3235 static unsigned long __init usemap_size(unsigned long zonesize)
3237 unsigned long usemapsize;
3239 usemapsize = roundup(zonesize, pageblock_nr_pages);
3240 usemapsize = usemapsize >> pageblock_order;
3241 usemapsize *= NR_PAGEBLOCK_BITS;
3242 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
3244 return usemapsize / 8;
3247 static void __init setup_usemap(struct pglist_data *pgdat,
3248 struct zone *zone, unsigned long zonesize)
3250 unsigned long usemapsize = usemap_size(zonesize);
3251 zone->pageblock_flags = NULL;
3253 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
3254 memset(zone->pageblock_flags, 0, usemapsize);
3258 static void inline setup_usemap(struct pglist_data *pgdat,
3259 struct zone *zone, unsigned long zonesize) {}
3260 #endif /* CONFIG_SPARSEMEM */
3262 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3264 /* Return a sensible default order for the pageblock size. */
3265 static inline int pageblock_default_order(void)
3267 if (HPAGE_SHIFT > PAGE_SHIFT)
3268 return HUGETLB_PAGE_ORDER;
3273 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3274 static inline void __init set_pageblock_order(unsigned int order)
3276 /* Check that pageblock_nr_pages has not already been setup */
3277 if (pageblock_order)
3281 * Assume the largest contiguous order of interest is a huge page.
3282 * This value may be variable depending on boot parameters on IA64
3284 pageblock_order = order;
3286 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3289 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3290 * and pageblock_default_order() are unused as pageblock_order is set
3291 * at compile-time. See include/linux/pageblock-flags.h for the values of
3292 * pageblock_order based on the kernel config
3294 static inline int pageblock_default_order(unsigned int order)
3298 #define set_pageblock_order(x) do {} while (0)
3300 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3303 * Set up the zone data structures:
3304 * - mark all pages reserved
3305 * - mark all memory queues empty
3306 * - clear the memory bitmaps
3308 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
3309 unsigned long *zones_size, unsigned long *zholes_size)
3312 int nid = pgdat->node_id;
3313 unsigned long zone_start_pfn = pgdat->node_start_pfn;
3316 pgdat_resize_init(pgdat);
3317 pgdat->nr_zones = 0;
3318 init_waitqueue_head(&pgdat->kswapd_wait);
3319 pgdat->kswapd_max_order = 0;
3321 for (j = 0; j < MAX_NR_ZONES; j++) {
3322 struct zone *zone = pgdat->node_zones + j;
3323 unsigned long size, realsize, memmap_pages;
3325 size = zone_spanned_pages_in_node(nid, j, zones_size);
3326 realsize = size - zone_absent_pages_in_node(nid, j,
3330 * Adjust realsize so that it accounts for how much memory
3331 * is used by this zone for memmap. This affects the watermark
3332 * and per-cpu initialisations
3334 memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT;
3335 if (realsize >= memmap_pages) {
3336 realsize -= memmap_pages;
3338 " %s zone: %lu pages used for memmap\n",
3339 zone_names[j], memmap_pages);
3342 " %s zone: %lu pages exceeds realsize %lu\n",
3343 zone_names[j], memmap_pages, realsize);
3345 /* Account for reserved pages */
3346 if (j == 0 && realsize > dma_reserve) {
3347 realsize -= dma_reserve;
3348 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
3349 zone_names[0], dma_reserve);
3352 if (!is_highmem_idx(j))
3353 nr_kernel_pages += realsize;
3354 nr_all_pages += realsize;
3356 zone->spanned_pages = size;
3357 zone->present_pages = realsize;
3360 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3362 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3364 zone->name = zone_names[j];
3365 spin_lock_init(&zone->lock);
3366 spin_lock_init(&zone->lru_lock);
3367 zone_seqlock_init(zone);
3368 zone->zone_pgdat = pgdat;
3370 zone->prev_priority = DEF_PRIORITY;
3372 zone_pcp_init(zone);
3373 INIT_LIST_HEAD(&zone->active_list);
3374 INIT_LIST_HEAD(&zone->inactive_list);
3375 zone->nr_scan_active = 0;
3376 zone->nr_scan_inactive = 0;
3377 zap_zone_vm_stats(zone);
3382 set_pageblock_order(pageblock_default_order());
3383 setup_usemap(pgdat, zone, size);
3384 ret = init_currently_empty_zone(zone, zone_start_pfn,
3385 size, MEMMAP_EARLY);
3387 zone_start_pfn += size;
3391 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
3393 /* Skip empty nodes */
3394 if (!pgdat->node_spanned_pages)
3397 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3398 /* ia64 gets its own node_mem_map, before this, without bootmem */
3399 if (!pgdat->node_mem_map) {
3400 unsigned long size, start, end;
3404 * The zone's endpoints aren't required to be MAX_ORDER
3405 * aligned but the node_mem_map endpoints must be in order
3406 * for the buddy allocator to function correctly.
3408 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
3409 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
3410 end = ALIGN(end, MAX_ORDER_NR_PAGES);
3411 size = (end - start) * sizeof(struct page);
3412 map = alloc_remap(pgdat->node_id, size);
3414 map = alloc_bootmem_node(pgdat, size);
3415 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
3417 #ifndef CONFIG_NEED_MULTIPLE_NODES
3419 * With no DISCONTIG, the global mem_map is just set as node 0's
3421 if (pgdat == NODE_DATA(0)) {
3422 mem_map = NODE_DATA(0)->node_mem_map;
3423 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3424 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3425 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3426 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3429 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3432 void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
3433 unsigned long *zones_size, unsigned long node_start_pfn,
3434 unsigned long *zholes_size)
3436 pgdat->node_id = nid;
3437 pgdat->node_start_pfn = node_start_pfn;
3438 calculate_node_totalpages(pgdat, zones_size, zholes_size);
3440 alloc_node_mem_map(pgdat);
3442 free_area_init_core(pgdat, zones_size, zholes_size);
3445 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3447 #if MAX_NUMNODES > 1
3449 * Figure out the number of possible node ids.
3451 static void __init setup_nr_node_ids(void)
3454 unsigned int highest = 0;
3456 for_each_node_mask(node, node_possible_map)
3458 nr_node_ids = highest + 1;
3461 static inline void setup_nr_node_ids(void)
3467 * add_active_range - Register a range of PFNs backed by physical memory
3468 * @nid: The node ID the range resides on
3469 * @start_pfn: The start PFN of the available physical memory
3470 * @end_pfn: The end PFN of the available physical memory
3472 * These ranges are stored in an early_node_map[] and later used by
3473 * free_area_init_nodes() to calculate zone sizes and holes. If the
3474 * range spans a memory hole, it is up to the architecture to ensure
3475 * the memory is not freed by the bootmem allocator. If possible
3476 * the range being registered will be merged with existing ranges.
3478 void __init add_active_range(unsigned int nid, unsigned long start_pfn,
3479 unsigned long end_pfn)
3483 printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
3484 "%d entries of %d used\n",
3485 nid, start_pfn, end_pfn,
3486 nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3488 /* Merge with existing active regions if possible */
3489 for (i = 0; i < nr_nodemap_entries; i++) {
3490 if (early_node_map[i].nid != nid)
3493 /* Skip if an existing region covers this new one */
3494 if (start_pfn >= early_node_map[i].start_pfn &&
3495 end_pfn <= early_node_map[i].end_pfn)
3498 /* Merge forward if suitable */
3499 if (start_pfn <= early_node_map[i].end_pfn &&
3500 end_pfn > early_node_map[i].end_pfn) {
3501 early_node_map[i].end_pfn = end_pfn;
3505 /* Merge backward if suitable */
3506 if (start_pfn < early_node_map[i].end_pfn &&
3507 end_pfn >= early_node_map[i].start_pfn) {
3508 early_node_map[i].start_pfn = start_pfn;
3513 /* Check that early_node_map is large enough */
3514 if (i >= MAX_ACTIVE_REGIONS) {
3515 printk(KERN_CRIT "More than %d memory regions, truncating\n",
3516 MAX_ACTIVE_REGIONS);
3520 early_node_map[i].nid = nid;
3521 early_node_map[i].start_pfn = start_pfn;
3522 early_node_map[i].end_pfn = end_pfn;
3523 nr_nodemap_entries = i + 1;
3527 * shrink_active_range - Shrink an existing registered range of PFNs
3528 * @nid: The node id the range is on that should be shrunk
3529 * @old_end_pfn: The old end PFN of the range
3530 * @new_end_pfn: The new PFN of the range
3532 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3533 * The map is kept at the end physical page range that has already been
3534 * registered with add_active_range(). This function allows an arch to shrink
3535 * an existing registered range.
3537 void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
3538 unsigned long new_end_pfn)
3542 /* Find the old active region end and shrink */
3543 for_each_active_range_index_in_nid(i, nid)
3544 if (early_node_map[i].end_pfn == old_end_pfn) {
3545 early_node_map[i].end_pfn = new_end_pfn;
3551 * remove_all_active_ranges - Remove all currently registered regions
3553 * During discovery, it may be found that a table like SRAT is invalid
3554 * and an alternative discovery method must be used. This function removes
3555 * all currently registered regions.
3557 void __init remove_all_active_ranges(void)
3559 memset(early_node_map, 0, sizeof(early_node_map));
3560 nr_nodemap_entries = 0;
3561 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3562 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
3563 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
3564 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3567 /* Compare two active node_active_regions */
3568 static int __init cmp_node_active_region(const void *a, const void *b)
3570 struct node_active_region *arange = (struct node_active_region *)a;
3571 struct node_active_region *brange = (struct node_active_region *)b;
3573 /* Done this way to avoid overflows */
3574 if (arange->start_pfn > brange->start_pfn)
3576 if (arange->start_pfn < brange->start_pfn)
3582 /* sort the node_map by start_pfn */
3583 static void __init sort_node_map(void)
3585 sort(early_node_map, (size_t)nr_nodemap_entries,
3586 sizeof(struct node_active_region),
3587 cmp_node_active_region, NULL);
3590 /* Find the lowest pfn for a node */
3591 unsigned long __init find_min_pfn_for_node(unsigned long nid)
3594 unsigned long min_pfn = ULONG_MAX;
3596 /* Assuming a sorted map, the first range found has the starting pfn */
3597 for_each_active_range_index_in_nid(i, nid)
3598 min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3600 if (min_pfn == ULONG_MAX) {
3602 "Could not find start_pfn for node %lu\n", nid);
3610 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3612 * It returns the minimum PFN based on information provided via
3613 * add_active_range().
3615 unsigned long __init find_min_pfn_with_active_regions(void)
3617 return find_min_pfn_for_node(MAX_NUMNODES);
3621 * find_max_pfn_with_active_regions - Find the maximum PFN registered
3623 * It returns the maximum PFN based on information provided via
3624 * add_active_range().
3626 unsigned long __init find_max_pfn_with_active_regions(void)
3629 unsigned long max_pfn = 0;
3631 for (i = 0; i < nr_nodemap_entries; i++)
3632 max_pfn = max(max_pfn, early_node_map[i].end_pfn);
3638 * early_calculate_totalpages()
3639 * Sum pages in active regions for movable zone.
3640 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3642 static unsigned long __init early_calculate_totalpages(void)
3645 unsigned long totalpages = 0;
3647 for (i = 0; i < nr_nodemap_entries; i++) {
3648 unsigned long pages = early_node_map[i].end_pfn -
3649 early_node_map[i].start_pfn;
3650 totalpages += pages;
3652 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
3658 * Find the PFN the Movable zone begins in each node. Kernel memory
3659 * is spread evenly between nodes as long as the nodes have enough
3660 * memory. When they don't, some nodes will have more kernelcore than
3663 void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
3666 unsigned long usable_startpfn;
3667 unsigned long kernelcore_node, kernelcore_remaining;
3668 unsigned long totalpages = early_calculate_totalpages();
3669 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
3672 * If movablecore was specified, calculate what size of
3673 * kernelcore that corresponds so that memory usable for
3674 * any allocation type is evenly spread. If both kernelcore
3675 * and movablecore are specified, then the value of kernelcore
3676 * will be used for required_kernelcore if it's greater than
3677 * what movablecore would have allowed.
3679 if (required_movablecore) {
3680 unsigned long corepages;
3683 * Round-up so that ZONE_MOVABLE is at least as large as what
3684 * was requested by the user
3686 required_movablecore =
3687 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
3688 corepages = totalpages - required_movablecore;
3690 required_kernelcore = max(required_kernelcore, corepages);
3693 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3694 if (!required_kernelcore)
3697 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3698 find_usable_zone_for_movable();
3699 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
3702 /* Spread kernelcore memory as evenly as possible throughout nodes */
3703 kernelcore_node = required_kernelcore / usable_nodes;
3704 for_each_node_state(nid, N_HIGH_MEMORY) {
3706 * Recalculate kernelcore_node if the division per node
3707 * now exceeds what is necessary to satisfy the requested
3708 * amount of memory for the kernel
3710 if (required_kernelcore < kernelcore_node)
3711 kernelcore_node = required_kernelcore / usable_nodes;
3714 * As the map is walked, we track how much memory is usable
3715 * by the kernel using kernelcore_remaining. When it is
3716 * 0, the rest of the node is usable by ZONE_MOVABLE
3718 kernelcore_remaining = kernelcore_node;
3720 /* Go through each range of PFNs within this node */
3721 for_each_active_range_index_in_nid(i, nid) {
3722 unsigned long start_pfn, end_pfn;
3723 unsigned long size_pages;
3725 start_pfn = max(early_node_map[i].start_pfn,
3726 zone_movable_pfn[nid]);
3727 end_pfn = early_node_map[i].end_pfn;
3728 if (start_pfn >= end_pfn)
3731 /* Account for what is only usable for kernelcore */
3732 if (start_pfn < usable_startpfn) {
3733 unsigned long kernel_pages;
3734 kernel_pages = min(end_pfn, usable_startpfn)
3737 kernelcore_remaining -= min(kernel_pages,
3738 kernelcore_remaining);
3739 required_kernelcore -= min(kernel_pages,
3740 required_kernelcore);
3742 /* Continue if range is now fully accounted */
3743 if (end_pfn <= usable_startpfn) {
3746 * Push zone_movable_pfn to the end so
3747 * that if we have to rebalance
3748 * kernelcore across nodes, we will
3749 * not double account here
3751 zone_movable_pfn[nid] = end_pfn;
3754 start_pfn = usable_startpfn;
3758 * The usable PFN range for ZONE_MOVABLE is from
3759 * start_pfn->end_pfn. Calculate size_pages as the
3760 * number of pages used as kernelcore
3762 size_pages = end_pfn - start_pfn;
3763 if (size_pages > kernelcore_remaining)
3764 size_pages = kernelcore_remaining;
3765 zone_movable_pfn[nid] = start_pfn + size_pages;
3768 * Some kernelcore has been met, update counts and
3769 * break if the kernelcore for this node has been
3772 required_kernelcore -= min(required_kernelcore,
3774 kernelcore_remaining -= size_pages;
3775 if (!kernelcore_remaining)
3781 * If there is still required_kernelcore, we do another pass with one
3782 * less node in the count. This will push zone_movable_pfn[nid] further
3783 * along on the nodes that still have memory until kernelcore is
3787 if (usable_nodes && required_kernelcore > usable_nodes)
3790 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3791 for (nid = 0; nid < MAX_NUMNODES; nid++)
3792 zone_movable_pfn[nid] =
3793 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
3796 /* Any regular memory on that node ? */
3797 static void check_for_regular_memory(pg_data_t *pgdat)
3799 #ifdef CONFIG_HIGHMEM
3800 enum zone_type zone_type;
3802 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
3803 struct zone *zone = &pgdat->node_zones[zone_type];
3804 if (zone->present_pages)
3805 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
3811 * free_area_init_nodes - Initialise all pg_data_t and zone data
3812 * @max_zone_pfn: an array of max PFNs for each zone
3814 * This will call free_area_init_node() for each active node in the system.
3815 * Using the page ranges provided by add_active_range(), the size of each
3816 * zone in each node and their holes is calculated. If the maximum PFN
3817 * between two adjacent zones match, it is assumed that the zone is empty.
3818 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3819 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3820 * starts where the previous one ended. For example, ZONE_DMA32 starts
3821 * at arch_max_dma_pfn.
3823 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
3828 /* Sort early_node_map as initialisation assumes it is sorted */
3831 /* Record where the zone boundaries are */
3832 memset(arch_zone_lowest_possible_pfn, 0,
3833 sizeof(arch_zone_lowest_possible_pfn));
3834 memset(arch_zone_highest_possible_pfn, 0,
3835 sizeof(arch_zone_highest_possible_pfn));
3836 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
3837 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
3838 for (i = 1; i < MAX_NR_ZONES; i++) {
3839 if (i == ZONE_MOVABLE)
3841 arch_zone_lowest_possible_pfn[i] =
3842 arch_zone_highest_possible_pfn[i-1];
3843 arch_zone_highest_possible_pfn[i] =
3844 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
3846 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
3847 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
3849 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
3850 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
3851 find_zone_movable_pfns_for_nodes(zone_movable_pfn);
3853 /* Print out the zone ranges */
3854 printk("Zone PFN ranges:\n");
3855 for (i = 0; i < MAX_NR_ZONES; i++) {
3856 if (i == ZONE_MOVABLE)
3858 printk(" %-8s %8lu -> %8lu\n",
3860 arch_zone_lowest_possible_pfn[i],
3861 arch_zone_highest_possible_pfn[i]);
3864 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
3865 printk("Movable zone start PFN for each node\n");
3866 for (i = 0; i < MAX_NUMNODES; i++) {
3867 if (zone_movable_pfn[i])
3868 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
3871 /* Print out the early_node_map[] */
3872 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
3873 for (i = 0; i < nr_nodemap_entries; i++)
3874 printk(" %3d: %8lu -> %8lu\n", early_node_map[i].nid,
3875 early_node_map[i].start_pfn,
3876 early_node_map[i].end_pfn);
3878 /* Initialise every node */
3879 setup_nr_node_ids();
3880 for_each_online_node(nid) {
3881 pg_data_t *pgdat = NODE_DATA(nid);
3882 free_area_init_node(nid, pgdat, NULL,
3883 find_min_pfn_for_node(nid), NULL);
3885 /* Any memory on that node */
3886 if (pgdat->node_present_pages)
3887 node_set_state(nid, N_HIGH_MEMORY);
3888 check_for_regular_memory(pgdat);
3892 static int __init cmdline_parse_core(char *p, unsigned long *core)
3894 unsigned long long coremem;
3898 coremem = memparse(p, &p);
3899 *core = coremem >> PAGE_SHIFT;
3901 /* Paranoid check that UL is enough for the coremem value */
3902 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
3908 * kernelcore=size sets the amount of memory for use for allocations that
3909 * cannot be reclaimed or migrated.
3911 static int __init cmdline_parse_kernelcore(char *p)
3913 return cmdline_parse_core(p, &required_kernelcore);
3917 * movablecore=size sets the amount of memory for use for allocations that
3918 * can be reclaimed or migrated.
3920 static int __init cmdline_parse_movablecore(char *p)
3922 return cmdline_parse_core(p, &required_movablecore);
3925 early_param("kernelcore", cmdline_parse_kernelcore);
3926 early_param("movablecore", cmdline_parse_movablecore);
3928 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3931 * set_dma_reserve - set the specified number of pages reserved in the first zone
3932 * @new_dma_reserve: The number of pages to mark reserved
3934 * The per-cpu batchsize and zone watermarks are determined by present_pages.
3935 * In the DMA zone, a significant percentage may be consumed by kernel image
3936 * and other unfreeable allocations which can skew the watermarks badly. This
3937 * function may optionally be used to account for unfreeable pages in the
3938 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
3939 * smaller per-cpu batchsize.
3941 void __init set_dma_reserve(unsigned long new_dma_reserve)
3943 dma_reserve = new_dma_reserve;
3946 #ifndef CONFIG_NEED_MULTIPLE_NODES
3947 static bootmem_data_t contig_bootmem_data;
3948 struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
3950 EXPORT_SYMBOL(contig_page_data);
3953 void __init free_area_init(unsigned long *zones_size)
3955 free_area_init_node(0, NODE_DATA(0), zones_size,
3956 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
3959 static int page_alloc_cpu_notify(struct notifier_block *self,
3960 unsigned long action, void *hcpu)
3962 int cpu = (unsigned long)hcpu;
3964 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
3968 * Spill the event counters of the dead processor
3969 * into the current processors event counters.
3970 * This artificially elevates the count of the current
3973 vm_events_fold_cpu(cpu);
3976 * Zero the differential counters of the dead processor
3977 * so that the vm statistics are consistent.
3979 * This is only okay since the processor is dead and cannot
3980 * race with what we are doing.
3982 refresh_cpu_vm_stats(cpu);
3987 void __init page_alloc_init(void)
3989 hotcpu_notifier(page_alloc_cpu_notify, 0);
3993 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
3994 * or min_free_kbytes changes.
3996 static void calculate_totalreserve_pages(void)
3998 struct pglist_data *pgdat;
3999 unsigned long reserve_pages = 0;
4000 enum zone_type i, j;
4002 for_each_online_pgdat(pgdat) {
4003 for (i = 0; i < MAX_NR_ZONES; i++) {
4004 struct zone *zone = pgdat->node_zones + i;
4005 unsigned long max = 0;
4007 /* Find valid and maximum lowmem_reserve in the zone */
4008 for (j = i; j < MAX_NR_ZONES; j++) {
4009 if (zone->lowmem_reserve[j] > max)
4010 max = zone->lowmem_reserve[j];
4013 /* we treat pages_high as reserved pages. */
4014 max += zone->pages_high;
4016 if (max > zone->present_pages)
4017 max = zone->present_pages;
4018 reserve_pages += max;
4021 totalreserve_pages = reserve_pages;
4025 * setup_per_zone_lowmem_reserve - called whenever
4026 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4027 * has a correct pages reserved value, so an adequate number of
4028 * pages are left in the zone after a successful __alloc_pages().
4030 static void setup_per_zone_lowmem_reserve(void)
4032 struct pglist_data *pgdat;
4033 enum zone_type j, idx;
4035 for_each_online_pgdat(pgdat) {
4036 for (j = 0; j < MAX_NR_ZONES; j++) {
4037 struct zone *zone = pgdat->node_zones + j;
4038 unsigned long present_pages = zone->present_pages;
4040 zone->lowmem_reserve[j] = 0;
4044 struct zone *lower_zone;
4048 if (sysctl_lowmem_reserve_ratio[idx] < 1)
4049 sysctl_lowmem_reserve_ratio[idx] = 1;
4051 lower_zone = pgdat->node_zones + idx;
4052 lower_zone->lowmem_reserve[j] = present_pages /
4053 sysctl_lowmem_reserve_ratio[idx];
4054 present_pages += lower_zone->present_pages;
4059 /* update totalreserve_pages */
4060 calculate_totalreserve_pages();
4064 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4066 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4067 * with respect to min_free_kbytes.
4069 void setup_per_zone_pages_min(void)
4071 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
4072 unsigned long lowmem_pages = 0;
4074 unsigned long flags;
4076 /* Calculate total number of !ZONE_HIGHMEM pages */
4077 for_each_zone(zone) {
4078 if (!is_highmem(zone))
4079 lowmem_pages += zone->present_pages;
4082 for_each_zone(zone) {
4085 spin_lock_irqsave(&zone->lru_lock, flags);
4086 tmp = (u64)pages_min * zone->present_pages;
4087 do_div(tmp, lowmem_pages);
4088 if (is_highmem(zone)) {
4090 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4091 * need highmem pages, so cap pages_min to a small
4094 * The (pages_high-pages_low) and (pages_low-pages_min)
4095 * deltas controls asynch page reclaim, and so should
4096 * not be capped for highmem.
4100 min_pages = zone->present_pages / 1024;
4101 if (min_pages < SWAP_CLUSTER_MAX)
4102 min_pages = SWAP_CLUSTER_MAX;
4103 if (min_pages > 128)
4105 zone->pages_min = min_pages;
4108 * If it's a lowmem zone, reserve a number of pages
4109 * proportionate to the zone's size.
4111 zone->pages_min = tmp;
4114 zone->pages_low = zone->pages_min + (tmp >> 2);
4115 zone->pages_high = zone->pages_min + (tmp >> 1);
4116 setup_zone_migrate_reserve(zone);
4117 spin_unlock_irqrestore(&zone->lru_lock, flags);
4120 /* update totalreserve_pages */
4121 calculate_totalreserve_pages();
4125 * Initialise min_free_kbytes.
4127 * For small machines we want it small (128k min). For large machines
4128 * we want it large (64MB max). But it is not linear, because network
4129 * bandwidth does not increase linearly with machine size. We use
4131 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4132 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4148 static int __init init_per_zone_pages_min(void)
4150 unsigned long lowmem_kbytes;
4152 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
4154 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
4155 if (min_free_kbytes < 128)
4156 min_free_kbytes = 128;
4157 if (min_free_kbytes > 65536)
4158 min_free_kbytes = 65536;
4159 setup_per_zone_pages_min();
4160 setup_per_zone_lowmem_reserve();
4163 module_init(init_per_zone_pages_min)
4166 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4167 * that we can call two helper functions whenever min_free_kbytes
4170 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
4171 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4173 proc_dointvec(table, write, file, buffer, length, ppos);
4175 setup_per_zone_pages_min();
4180 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4181 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4186 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4191 zone->min_unmapped_pages = (zone->present_pages *
4192 sysctl_min_unmapped_ratio) / 100;
4196 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4197 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4202 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4207 zone->min_slab_pages = (zone->present_pages *
4208 sysctl_min_slab_ratio) / 100;
4214 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4215 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4216 * whenever sysctl_lowmem_reserve_ratio changes.
4218 * The reserve ratio obviously has absolutely no relation with the
4219 * pages_min watermarks. The lowmem reserve ratio can only make sense
4220 * if in function of the boot time zone sizes.
4222 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4223 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4225 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4226 setup_per_zone_lowmem_reserve();
4231 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4232 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4233 * can have before it gets flushed back to buddy allocator.
4236 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
4237 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4243 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4244 if (!write || (ret == -EINVAL))
4246 for_each_zone(zone) {
4247 for_each_online_cpu(cpu) {
4249 high = zone->present_pages / percpu_pagelist_fraction;
4250 setup_pagelist_highmark(zone_pcp(zone, cpu), high);
4256 int hashdist = HASHDIST_DEFAULT;
4259 static int __init set_hashdist(char *str)
4263 hashdist = simple_strtoul(str, &str, 0);
4266 __setup("hashdist=", set_hashdist);
4270 * allocate a large system hash table from bootmem
4271 * - it is assumed that the hash table must contain an exact power-of-2
4272 * quantity of entries
4273 * - limit is the number of hash buckets, not the total allocation size
4275 void *__init alloc_large_system_hash(const char *tablename,
4276 unsigned long bucketsize,
4277 unsigned long numentries,
4280 unsigned int *_hash_shift,
4281 unsigned int *_hash_mask,
4282 unsigned long limit)
4284 unsigned long long max = limit;
4285 unsigned long log2qty, size;
4288 /* allow the kernel cmdline to have a say */
4290 /* round applicable memory size up to nearest megabyte */
4291 numentries = nr_kernel_pages;
4292 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
4293 numentries >>= 20 - PAGE_SHIFT;
4294 numentries <<= 20 - PAGE_SHIFT;
4296 /* limit to 1 bucket per 2^scale bytes of low memory */
4297 if (scale > PAGE_SHIFT)
4298 numentries >>= (scale - PAGE_SHIFT);
4300 numentries <<= (PAGE_SHIFT - scale);
4302 /* Make sure we've got at least a 0-order allocation.. */
4303 if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4304 numentries = PAGE_SIZE / bucketsize;
4306 numentries = roundup_pow_of_two(numentries);
4308 /* limit allocation size to 1/16 total memory by default */
4310 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
4311 do_div(max, bucketsize);
4314 if (numentries > max)
4317 log2qty = ilog2(numentries);
4320 size = bucketsize << log2qty;
4321 if (flags & HASH_EARLY)
4322 table = alloc_bootmem(size);
4324 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
4326 unsigned long order;
4327 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
4329 table = (void*) __get_free_pages(GFP_ATOMIC, order);
4331 * If bucketsize is not a power-of-two, we may free
4332 * some pages at the end of hash table.
4335 unsigned long alloc_end = (unsigned long)table +
4336 (PAGE_SIZE << order);
4337 unsigned long used = (unsigned long)table +
4339 split_page(virt_to_page(table), order);
4340 while (used < alloc_end) {
4346 } while (!table && size > PAGE_SIZE && --log2qty);
4349 panic("Failed to allocate %s hash table\n", tablename);
4351 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
4354 ilog2(size) - PAGE_SHIFT,
4358 *_hash_shift = log2qty;
4360 *_hash_mask = (1 << log2qty) - 1;
4365 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4366 struct page *pfn_to_page(unsigned long pfn)
4368 return __pfn_to_page(pfn);
4370 unsigned long page_to_pfn(struct page *page)
4372 return __page_to_pfn(page);
4374 EXPORT_SYMBOL(pfn_to_page);
4375 EXPORT_SYMBOL(page_to_pfn);
4376 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4378 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4379 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
4382 #ifdef CONFIG_SPARSEMEM
4383 return __pfn_to_section(pfn)->pageblock_flags;
4385 return zone->pageblock_flags;
4386 #endif /* CONFIG_SPARSEMEM */
4389 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
4391 #ifdef CONFIG_SPARSEMEM
4392 pfn &= (PAGES_PER_SECTION-1);
4393 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4395 pfn = pfn - zone->zone_start_pfn;
4396 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4397 #endif /* CONFIG_SPARSEMEM */
4401 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4402 * @page: The page within the block of interest
4403 * @start_bitidx: The first bit of interest to retrieve
4404 * @end_bitidx: The last bit of interest
4405 * returns pageblock_bits flags
4407 unsigned long get_pageblock_flags_group(struct page *page,
4408 int start_bitidx, int end_bitidx)
4411 unsigned long *bitmap;
4412 unsigned long pfn, bitidx;
4413 unsigned long flags = 0;
4414 unsigned long value = 1;
4416 zone = page_zone(page);
4417 pfn = page_to_pfn(page);
4418 bitmap = get_pageblock_bitmap(zone, pfn);
4419 bitidx = pfn_to_bitidx(zone, pfn);
4421 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4422 if (test_bit(bitidx + start_bitidx, bitmap))
4429 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4430 * @page: The page within the block of interest
4431 * @start_bitidx: The first bit of interest
4432 * @end_bitidx: The last bit of interest
4433 * @flags: The flags to set
4435 void set_pageblock_flags_group(struct page *page, unsigned long flags,
4436 int start_bitidx, int end_bitidx)
4439 unsigned long *bitmap;
4440 unsigned long pfn, bitidx;
4441 unsigned long value = 1;
4443 zone = page_zone(page);
4444 pfn = page_to_pfn(page);
4445 bitmap = get_pageblock_bitmap(zone, pfn);
4446 bitidx = pfn_to_bitidx(zone, pfn);
4448 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4450 __set_bit(bitidx + start_bitidx, bitmap);
4452 __clear_bit(bitidx + start_bitidx, bitmap);
4456 * This is designed as sub function...plz see page_isolation.c also.
4457 * set/clear page block's type to be ISOLATE.
4458 * page allocater never alloc memory from ISOLATE block.
4461 int set_migratetype_isolate(struct page *page)
4464 unsigned long flags;
4467 zone = page_zone(page);
4468 spin_lock_irqsave(&zone->lock, flags);
4470 * In future, more migrate types will be able to be isolation target.
4472 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
4474 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
4475 move_freepages_block(zone, page, MIGRATE_ISOLATE);
4478 spin_unlock_irqrestore(&zone->lock, flags);
4484 void unset_migratetype_isolate(struct page *page)
4487 unsigned long flags;
4488 zone = page_zone(page);
4489 spin_lock_irqsave(&zone->lock, flags);
4490 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
4492 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4493 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4495 spin_unlock_irqrestore(&zone->lock, flags);
4498 #ifdef CONFIG_MEMORY_HOTREMOVE
4500 * All pages in the range must be isolated before calling this.
4503 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
4509 unsigned long flags;
4510 /* find the first valid pfn */
4511 for (pfn = start_pfn; pfn < end_pfn; pfn++)
4516 zone = page_zone(pfn_to_page(pfn));
4517 spin_lock_irqsave(&zone->lock, flags);
4519 while (pfn < end_pfn) {
4520 if (!pfn_valid(pfn)) {
4524 page = pfn_to_page(pfn);
4525 BUG_ON(page_count(page));
4526 BUG_ON(!PageBuddy(page));
4527 order = page_order(page);
4528 #ifdef CONFIG_DEBUG_VM
4529 printk(KERN_INFO "remove from free list %lx %d %lx\n",
4530 pfn, 1 << order, end_pfn);
4532 list_del(&page->lru);
4533 rmv_page_order(page);
4534 zone->free_area[order].nr_free--;
4535 __mod_zone_page_state(zone, NR_FREE_PAGES,
4537 for (i = 0; i < (1 << order); i++)
4538 SetPageReserved((page+i));
4539 pfn += (1 << order);
4541 spin_unlock_irqrestore(&zone->lock, flags);