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/bootmem.h>
23 #include <linux/compiler.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/suspend.h>
27 #include <linux/pagevec.h>
28 #include <linux/blkdev.h>
29 #include <linux/slab.h>
30 #include <linux/notifier.h>
31 #include <linux/topology.h>
32 #include <linux/sysctl.h>
33 #include <linux/cpu.h>
34 #include <linux/cpuset.h>
35 #include <linux/memory_hotplug.h>
36 #include <linux/nodemask.h>
37 #include <linux/vmalloc.h>
38 #include <linux/mempolicy.h>
39 #include <linux/stop_machine.h>
40 #include <linux/sort.h>
41 #include <linux/pfn.h>
42 #include <linux/backing-dev.h>
43 #include <linux/fault-inject.h>
45 #include <asm/tlbflush.h>
46 #include <asm/div64.h>
50 * Array of node states.
52 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
53 [N_POSSIBLE] = NODE_MASK_ALL,
54 [N_ONLINE] = { { [0] = 1UL } },
56 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
58 [N_HIGH_MEMORY] = { { [0] = 1UL } },
60 [N_CPU] = { { [0] = 1UL } },
63 EXPORT_SYMBOL(node_states);
65 unsigned long totalram_pages __read_mostly;
66 unsigned long totalreserve_pages __read_mostly;
68 int percpu_pagelist_fraction;
70 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
71 int pageblock_order __read_mostly;
74 static void __free_pages_ok(struct page *page, unsigned int order);
77 * results with 256, 32 in the lowmem_reserve sysctl:
78 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
79 * 1G machine -> (16M dma, 784M normal, 224M high)
80 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
81 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
82 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
84 * TBD: should special case ZONE_DMA32 machines here - in those we normally
85 * don't need any ZONE_NORMAL reservation
87 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
88 #ifdef CONFIG_ZONE_DMA
91 #ifdef CONFIG_ZONE_DMA32
100 EXPORT_SYMBOL(totalram_pages);
102 static char * const zone_names[MAX_NR_ZONES] = {
103 #ifdef CONFIG_ZONE_DMA
106 #ifdef CONFIG_ZONE_DMA32
110 #ifdef CONFIG_HIGHMEM
116 int min_free_kbytes = 1024;
118 unsigned long __meminitdata nr_kernel_pages;
119 unsigned long __meminitdata nr_all_pages;
120 static unsigned long __meminitdata dma_reserve;
122 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
124 * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct
125 * ranges of memory (RAM) that may be registered with add_active_range().
126 * Ranges passed to add_active_range() will be merged if possible
127 * so the number of times add_active_range() can be called is
128 * related to the number of nodes and the number of holes
130 #ifdef CONFIG_MAX_ACTIVE_REGIONS
131 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
132 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
134 #if MAX_NUMNODES >= 32
135 /* If there can be many nodes, allow up to 50 holes per node */
136 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
138 /* By default, allow up to 256 distinct regions */
139 #define MAX_ACTIVE_REGIONS 256
143 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
144 static int __meminitdata nr_nodemap_entries;
145 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
146 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
147 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
148 static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES];
149 static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES];
150 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
151 unsigned long __initdata required_kernelcore;
152 static unsigned long __initdata required_movablecore;
153 unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
155 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
157 EXPORT_SYMBOL(movable_zone);
158 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
161 int nr_node_ids __read_mostly = MAX_NUMNODES;
162 EXPORT_SYMBOL(nr_node_ids);
165 int page_group_by_mobility_disabled __read_mostly;
167 static void set_pageblock_migratetype(struct page *page, int migratetype)
169 set_pageblock_flags_group(page, (unsigned long)migratetype,
170 PB_migrate, PB_migrate_end);
173 #ifdef CONFIG_DEBUG_VM
174 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
178 unsigned long pfn = page_to_pfn(page);
181 seq = zone_span_seqbegin(zone);
182 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
184 else if (pfn < zone->zone_start_pfn)
186 } while (zone_span_seqretry(zone, seq));
191 static int page_is_consistent(struct zone *zone, struct page *page)
193 if (!pfn_valid_within(page_to_pfn(page)))
195 if (zone != page_zone(page))
201 * Temporary debugging check for pages not lying within a given zone.
203 static int bad_range(struct zone *zone, struct page *page)
205 if (page_outside_zone_boundaries(zone, page))
207 if (!page_is_consistent(zone, page))
213 static inline int bad_range(struct zone *zone, struct page *page)
219 static void bad_page(struct page *page)
221 printk(KERN_EMERG "Bad page state in process '%s'\n"
222 KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
223 KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
224 KERN_EMERG "Backtrace:\n",
225 current->comm, page, (int)(2*sizeof(unsigned long)),
226 (unsigned long)page->flags, page->mapping,
227 page_mapcount(page), page_count(page));
229 page->flags &= ~(1 << PG_lru |
239 set_page_count(page, 0);
240 reset_page_mapcount(page);
241 page->mapping = NULL;
242 add_taint(TAINT_BAD_PAGE);
246 * Higher-order pages are called "compound pages". They are structured thusly:
248 * The first PAGE_SIZE page is called the "head page".
250 * The remaining PAGE_SIZE pages are called "tail pages".
252 * All pages have PG_compound set. All pages have their ->private pointing at
253 * the head page (even the head page has this).
255 * The first tail page's ->lru.next holds the address of the compound page's
256 * put_page() function. Its ->lru.prev holds the order of allocation.
257 * This usage means that zero-order pages may not be compound.
260 static void free_compound_page(struct page *page)
262 __free_pages_ok(page, compound_order(page));
265 static void prep_compound_page(struct page *page, unsigned long order)
268 int nr_pages = 1 << order;
270 set_compound_page_dtor(page, free_compound_page);
271 set_compound_order(page, order);
273 for (i = 1; i < nr_pages; i++) {
274 struct page *p = page + i;
277 p->first_page = page;
281 static void destroy_compound_page(struct page *page, unsigned long order)
284 int nr_pages = 1 << order;
286 if (unlikely(compound_order(page) != order))
289 if (unlikely(!PageHead(page)))
291 __ClearPageHead(page);
292 for (i = 1; i < nr_pages; i++) {
293 struct page *p = page + i;
295 if (unlikely(!PageTail(p) |
296 (p->first_page != page)))
302 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
306 VM_BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
308 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
309 * and __GFP_HIGHMEM from hard or soft interrupt context.
311 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
312 for (i = 0; i < (1 << order); i++)
313 clear_highpage(page + i);
316 static inline void set_page_order(struct page *page, int order)
318 set_page_private(page, order);
319 __SetPageBuddy(page);
322 static inline void rmv_page_order(struct page *page)
324 __ClearPageBuddy(page);
325 set_page_private(page, 0);
329 * Locate the struct page for both the matching buddy in our
330 * pair (buddy1) and the combined O(n+1) page they form (page).
332 * 1) Any buddy B1 will have an order O twin B2 which satisfies
333 * the following equation:
335 * For example, if the starting buddy (buddy2) is #8 its order
337 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
339 * 2) Any buddy B will have an order O+1 parent P which
340 * satisfies the following equation:
343 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
345 static inline struct page *
346 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
348 unsigned long buddy_idx = page_idx ^ (1 << order);
350 return page + (buddy_idx - page_idx);
353 static inline unsigned long
354 __find_combined_index(unsigned long page_idx, unsigned int order)
356 return (page_idx & ~(1 << order));
360 * This function checks whether a page is free && is the buddy
361 * we can do coalesce a page and its buddy if
362 * (a) the buddy is not in a hole &&
363 * (b) the buddy is in the buddy system &&
364 * (c) a page and its buddy have the same order &&
365 * (d) a page and its buddy are in the same zone.
367 * For recording whether a page is in the buddy system, we use PG_buddy.
368 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
370 * For recording page's order, we use page_private(page).
372 static inline int page_is_buddy(struct page *page, struct page *buddy,
375 if (!pfn_valid_within(page_to_pfn(buddy)))
378 if (page_zone_id(page) != page_zone_id(buddy))
381 if (PageBuddy(buddy) && page_order(buddy) == order) {
382 BUG_ON(page_count(buddy) != 0);
389 * Freeing function for a buddy system allocator.
391 * The concept of a buddy system is to maintain direct-mapped table
392 * (containing bit values) for memory blocks of various "orders".
393 * The bottom level table contains the map for the smallest allocatable
394 * units of memory (here, pages), and each level above it describes
395 * pairs of units from the levels below, hence, "buddies".
396 * At a high level, all that happens here is marking the table entry
397 * at the bottom level available, and propagating the changes upward
398 * as necessary, plus some accounting needed to play nicely with other
399 * parts of the VM system.
400 * At each level, we keep a list of pages, which are heads of continuous
401 * free pages of length of (1 << order) and marked with PG_buddy. Page's
402 * order is recorded in page_private(page) field.
403 * So when we are allocating or freeing one, we can derive the state of the
404 * other. That is, if we allocate a small block, and both were
405 * free, the remainder of the region must be split into blocks.
406 * If a block is freed, and its buddy is also free, then this
407 * triggers coalescing into a block of larger size.
412 static inline void __free_one_page(struct page *page,
413 struct zone *zone, unsigned int order)
415 unsigned long page_idx;
416 int order_size = 1 << order;
417 int migratetype = get_pageblock_migratetype(page);
419 if (unlikely(PageCompound(page)))
420 destroy_compound_page(page, order);
422 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
424 VM_BUG_ON(page_idx & (order_size - 1));
425 VM_BUG_ON(bad_range(zone, page));
427 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
428 while (order < MAX_ORDER-1) {
429 unsigned long combined_idx;
432 buddy = __page_find_buddy(page, page_idx, order);
433 if (!page_is_buddy(page, buddy, order))
434 break; /* Move the buddy up one level. */
436 list_del(&buddy->lru);
437 zone->free_area[order].nr_free--;
438 rmv_page_order(buddy);
439 combined_idx = __find_combined_index(page_idx, order);
440 page = page + (combined_idx - page_idx);
441 page_idx = combined_idx;
444 set_page_order(page, order);
446 &zone->free_area[order].free_list[migratetype]);
447 zone->free_area[order].nr_free++;
450 static inline int free_pages_check(struct page *page)
452 if (unlikely(page_mapcount(page) |
453 (page->mapping != NULL) |
454 (page_count(page) != 0) |
467 __ClearPageDirty(page);
469 * For now, we report if PG_reserved was found set, but do not
470 * clear it, and do not free the page. But we shall soon need
471 * to do more, for when the ZERO_PAGE count wraps negative.
473 return PageReserved(page);
477 * Frees a list of pages.
478 * Assumes all pages on list are in same zone, and of same order.
479 * count is the number of pages to free.
481 * If the zone was previously in an "all pages pinned" state then look to
482 * see if this freeing clears that state.
484 * And clear the zone's pages_scanned counter, to hold off the "all pages are
485 * pinned" detection logic.
487 static void free_pages_bulk(struct zone *zone, int count,
488 struct list_head *list, int order)
490 spin_lock(&zone->lock);
491 zone->all_unreclaimable = 0;
492 zone->pages_scanned = 0;
496 VM_BUG_ON(list_empty(list));
497 page = list_entry(list->prev, struct page, lru);
498 /* have to delete it as __free_one_page list manipulates */
499 list_del(&page->lru);
500 __free_one_page(page, zone, order);
502 spin_unlock(&zone->lock);
505 static void free_one_page(struct zone *zone, struct page *page, int order)
507 spin_lock(&zone->lock);
508 zone->all_unreclaimable = 0;
509 zone->pages_scanned = 0;
510 __free_one_page(page, zone, order);
511 spin_unlock(&zone->lock);
514 static void __free_pages_ok(struct page *page, unsigned int order)
520 for (i = 0 ; i < (1 << order) ; ++i)
521 reserved += free_pages_check(page + i);
525 if (!PageHighMem(page))
526 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
527 arch_free_page(page, order);
528 kernel_map_pages(page, 1 << order, 0);
530 local_irq_save(flags);
531 __count_vm_events(PGFREE, 1 << order);
532 free_one_page(page_zone(page), page, order);
533 local_irq_restore(flags);
537 * permit the bootmem allocator to evade page validation on high-order frees
539 void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order)
542 __ClearPageReserved(page);
543 set_page_count(page, 0);
544 set_page_refcounted(page);
550 for (loop = 0; loop < BITS_PER_LONG; loop++) {
551 struct page *p = &page[loop];
553 if (loop + 1 < BITS_PER_LONG)
555 __ClearPageReserved(p);
556 set_page_count(p, 0);
559 set_page_refcounted(page);
560 __free_pages(page, order);
566 * The order of subdivision here is critical for the IO subsystem.
567 * Please do not alter this order without good reasons and regression
568 * testing. Specifically, as large blocks of memory are subdivided,
569 * the order in which smaller blocks are delivered depends on the order
570 * they're subdivided in this function. This is the primary factor
571 * influencing the order in which pages are delivered to the IO
572 * subsystem according to empirical testing, and this is also justified
573 * by considering the behavior of a buddy system containing a single
574 * large block of memory acted on by a series of small allocations.
575 * This behavior is a critical factor in sglist merging's success.
579 static inline void expand(struct zone *zone, struct page *page,
580 int low, int high, struct free_area *area,
583 unsigned long size = 1 << high;
589 VM_BUG_ON(bad_range(zone, &page[size]));
590 list_add(&page[size].lru, &area->free_list[migratetype]);
592 set_page_order(&page[size], high);
597 * This page is about to be returned from the page allocator
599 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
601 if (unlikely(page_mapcount(page) |
602 (page->mapping != NULL) |
603 (page_count(page) != 0) |
618 * For now, we report if PG_reserved was found set, but do not
619 * clear it, and do not allocate the page: as a safety net.
621 if (PageReserved(page))
624 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead |
625 1 << PG_referenced | 1 << PG_arch_1 |
626 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
627 set_page_private(page, 0);
628 set_page_refcounted(page);
630 arch_alloc_page(page, order);
631 kernel_map_pages(page, 1 << order, 1);
633 if (gfp_flags & __GFP_ZERO)
634 prep_zero_page(page, order, gfp_flags);
636 if (order && (gfp_flags & __GFP_COMP))
637 prep_compound_page(page, order);
643 * Go through the free lists for the given migratetype and remove
644 * the smallest available page from the freelists
646 static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
649 unsigned int current_order;
650 struct free_area * area;
653 /* Find a page of the appropriate size in the preferred list */
654 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
655 area = &(zone->free_area[current_order]);
656 if (list_empty(&area->free_list[migratetype]))
659 page = list_entry(area->free_list[migratetype].next,
661 list_del(&page->lru);
662 rmv_page_order(page);
664 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
665 expand(zone, page, order, current_order, area, migratetype);
674 * This array describes the order lists are fallen back to when
675 * the free lists for the desirable migrate type are depleted
677 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
678 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
679 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
680 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
681 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
685 * Move the free pages in a range to the free lists of the requested type.
686 * Note that start_page and end_pages are not aligned on a pageblock
687 * boundary. If alignment is required, use move_freepages_block()
689 int move_freepages(struct zone *zone,
690 struct page *start_page, struct page *end_page,
697 #ifndef CONFIG_HOLES_IN_ZONE
699 * page_zone is not safe to call in this context when
700 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
701 * anyway as we check zone boundaries in move_freepages_block().
702 * Remove at a later date when no bug reports exist related to
703 * grouping pages by mobility
705 BUG_ON(page_zone(start_page) != page_zone(end_page));
708 for (page = start_page; page <= end_page;) {
709 if (!pfn_valid_within(page_to_pfn(page))) {
714 if (!PageBuddy(page)) {
719 order = page_order(page);
720 list_del(&page->lru);
722 &zone->free_area[order].free_list[migratetype]);
724 pages_moved += 1 << order;
730 int move_freepages_block(struct zone *zone, struct page *page, int migratetype)
732 unsigned long start_pfn, end_pfn;
733 struct page *start_page, *end_page;
735 start_pfn = page_to_pfn(page);
736 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
737 start_page = pfn_to_page(start_pfn);
738 end_page = start_page + pageblock_nr_pages - 1;
739 end_pfn = start_pfn + pageblock_nr_pages - 1;
741 /* Do not cross zone boundaries */
742 if (start_pfn < zone->zone_start_pfn)
744 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
747 return move_freepages(zone, start_page, end_page, migratetype);
750 /* Return the page with the lowest PFN in the list */
751 static struct page *min_page(struct list_head *list)
753 unsigned long min_pfn = -1UL;
754 struct page *min_page = NULL, *page;;
756 list_for_each_entry(page, list, lru) {
757 unsigned long pfn = page_to_pfn(page);
767 /* Remove an element from the buddy allocator from the fallback list */
768 static struct page *__rmqueue_fallback(struct zone *zone, int order,
769 int start_migratetype)
771 struct free_area * area;
776 /* Find the largest possible block of pages in the other list */
777 for (current_order = MAX_ORDER-1; current_order >= order;
779 for (i = 0; i < MIGRATE_TYPES - 1; i++) {
780 migratetype = fallbacks[start_migratetype][i];
782 /* MIGRATE_RESERVE handled later if necessary */
783 if (migratetype == MIGRATE_RESERVE)
786 area = &(zone->free_area[current_order]);
787 if (list_empty(&area->free_list[migratetype]))
790 /* Bias kernel allocations towards low pfns */
791 page = list_entry(area->free_list[migratetype].next,
793 if (unlikely(start_migratetype != MIGRATE_MOVABLE))
794 page = min_page(&area->free_list[migratetype]);
798 * If breaking a large block of pages, move all free
799 * pages to the preferred allocation list. If falling
800 * back for a reclaimable kernel allocation, be more
801 * agressive about taking ownership of free pages
803 if (unlikely(current_order >= (pageblock_order >> 1)) ||
804 start_migratetype == MIGRATE_RECLAIMABLE) {
806 pages = move_freepages_block(zone, page,
809 /* Claim the whole block if over half of it is free */
810 if (pages >= (1 << (pageblock_order-1)))
811 set_pageblock_migratetype(page,
814 migratetype = start_migratetype;
817 /* Remove the page from the freelists */
818 list_del(&page->lru);
819 rmv_page_order(page);
820 __mod_zone_page_state(zone, NR_FREE_PAGES,
823 if (current_order == pageblock_order)
824 set_pageblock_migratetype(page,
827 expand(zone, page, order, current_order, area, migratetype);
832 /* Use MIGRATE_RESERVE rather than fail an allocation */
833 return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
837 * Do the hard work of removing an element from the buddy allocator.
838 * Call me with the zone->lock already held.
840 static struct page *__rmqueue(struct zone *zone, unsigned int order,
845 page = __rmqueue_smallest(zone, order, migratetype);
848 page = __rmqueue_fallback(zone, order, migratetype);
854 * Obtain a specified number of elements from the buddy allocator, all under
855 * a single hold of the lock, for efficiency. Add them to the supplied list.
856 * Returns the number of new pages which were placed at *list.
858 static int rmqueue_bulk(struct zone *zone, unsigned int order,
859 unsigned long count, struct list_head *list,
864 spin_lock(&zone->lock);
865 for (i = 0; i < count; ++i) {
866 struct page *page = __rmqueue(zone, order, migratetype);
867 if (unlikely(page == NULL))
869 list_add(&page->lru, list);
870 set_page_private(page, migratetype);
872 spin_unlock(&zone->lock);
878 * Called from the vmstat counter updater to drain pagesets of this
879 * currently executing processor on remote nodes after they have
882 * Note that this function must be called with the thread pinned to
883 * a single processor.
885 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
890 local_irq_save(flags);
891 if (pcp->count >= pcp->batch)
892 to_drain = pcp->batch;
894 to_drain = pcp->count;
895 free_pages_bulk(zone, to_drain, &pcp->list, 0);
896 pcp->count -= to_drain;
897 local_irq_restore(flags);
901 static void __drain_pages(unsigned int cpu)
907 for_each_zone(zone) {
908 struct per_cpu_pageset *pset;
910 if (!populated_zone(zone))
913 pset = zone_pcp(zone, cpu);
914 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
915 struct per_cpu_pages *pcp;
918 local_irq_save(flags);
919 free_pages_bulk(zone, pcp->count, &pcp->list, 0);
921 local_irq_restore(flags);
926 #ifdef CONFIG_HIBERNATION
928 void mark_free_pages(struct zone *zone)
930 unsigned long pfn, max_zone_pfn;
933 struct list_head *curr;
935 if (!zone->spanned_pages)
938 spin_lock_irqsave(&zone->lock, flags);
940 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
941 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
942 if (pfn_valid(pfn)) {
943 struct page *page = pfn_to_page(pfn);
945 if (!swsusp_page_is_forbidden(page))
946 swsusp_unset_page_free(page);
949 for_each_migratetype_order(order, t) {
950 list_for_each(curr, &zone->free_area[order].free_list[t]) {
953 pfn = page_to_pfn(list_entry(curr, struct page, lru));
954 for (i = 0; i < (1UL << order); i++)
955 swsusp_set_page_free(pfn_to_page(pfn + i));
958 spin_unlock_irqrestore(&zone->lock, flags);
960 #endif /* CONFIG_PM */
963 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
965 void drain_local_pages(void)
969 local_irq_save(flags);
970 __drain_pages(smp_processor_id());
971 local_irq_restore(flags);
974 void smp_drain_local_pages(void *arg)
980 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
982 void drain_all_local_pages(void)
986 local_irq_save(flags);
987 __drain_pages(smp_processor_id());
988 local_irq_restore(flags);
990 smp_call_function(smp_drain_local_pages, NULL, 0, 1);
994 * Free a 0-order page
996 static void fastcall free_hot_cold_page(struct page *page, int cold)
998 struct zone *zone = page_zone(page);
999 struct per_cpu_pages *pcp;
1000 unsigned long flags;
1003 page->mapping = NULL;
1004 if (free_pages_check(page))
1007 if (!PageHighMem(page))
1008 debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1009 arch_free_page(page, 0);
1010 kernel_map_pages(page, 1, 0);
1012 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
1013 local_irq_save(flags);
1014 __count_vm_event(PGFREE);
1015 list_add(&page->lru, &pcp->list);
1016 set_page_private(page, get_pageblock_migratetype(page));
1018 if (pcp->count >= pcp->high) {
1019 free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
1020 pcp->count -= pcp->batch;
1022 local_irq_restore(flags);
1026 void fastcall free_hot_page(struct page *page)
1028 free_hot_cold_page(page, 0);
1031 void fastcall free_cold_page(struct page *page)
1033 free_hot_cold_page(page, 1);
1037 * split_page takes a non-compound higher-order page, and splits it into
1038 * n (1<<order) sub-pages: page[0..n]
1039 * Each sub-page must be freed individually.
1041 * Note: this is probably too low level an operation for use in drivers.
1042 * Please consult with lkml before using this in your driver.
1044 void split_page(struct page *page, unsigned int order)
1048 VM_BUG_ON(PageCompound(page));
1049 VM_BUG_ON(!page_count(page));
1050 for (i = 1; i < (1 << order); i++)
1051 set_page_refcounted(page + i);
1055 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1056 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1059 static struct page *buffered_rmqueue(struct zonelist *zonelist,
1060 struct zone *zone, int order, gfp_t gfp_flags)
1062 unsigned long flags;
1064 int cold = !!(gfp_flags & __GFP_COLD);
1066 int migratetype = allocflags_to_migratetype(gfp_flags);
1070 if (likely(order == 0)) {
1071 struct per_cpu_pages *pcp;
1073 pcp = &zone_pcp(zone, cpu)->pcp[cold];
1074 local_irq_save(flags);
1076 pcp->count = rmqueue_bulk(zone, 0,
1077 pcp->batch, &pcp->list, migratetype);
1078 if (unlikely(!pcp->count))
1082 /* Find a page of the appropriate migrate type */
1083 list_for_each_entry(page, &pcp->list, lru)
1084 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(zonelist, 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 alot 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 (jiffies - zlc->last_full_zap > 1 * 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 zone **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->zones;
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 zone **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->zones;
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 zone **z,
1365 nodemask_t *allowednodes)
1370 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **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 alloc_flags)
1384 struct page *page = NULL;
1385 int classzone_idx = zone_idx(zonelist->zones[0]);
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 */
1390 enum zone_type highest_zoneidx = -1; /* Gets set for policy zonelists */
1394 * Scan zonelist, looking for a zone with enough free.
1395 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1397 z = zonelist->zones;
1401 * In NUMA, this could be a policy zonelist which contains
1402 * zones that may not be allowed by the current gfp_mask.
1403 * Check the zone is allowed by the current flags
1405 if (unlikely(alloc_should_filter_zonelist(zonelist))) {
1406 if (highest_zoneidx == -1)
1407 highest_zoneidx = gfp_zone(gfp_mask);
1408 if (zone_idx(*z) > highest_zoneidx)
1412 if (NUMA_BUILD && zlc_active &&
1413 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1416 if ((alloc_flags & ALLOC_CPUSET) &&
1417 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1420 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1422 if (alloc_flags & ALLOC_WMARK_MIN)
1423 mark = zone->pages_min;
1424 else if (alloc_flags & ALLOC_WMARK_LOW)
1425 mark = zone->pages_low;
1427 mark = zone->pages_high;
1428 if (!zone_watermark_ok(zone, order, mark,
1429 classzone_idx, alloc_flags)) {
1430 if (!zone_reclaim_mode ||
1431 !zone_reclaim(zone, gfp_mask, order))
1432 goto this_zone_full;
1436 page = buffered_rmqueue(zonelist, zone, order, gfp_mask);
1441 zlc_mark_zone_full(zonelist, z);
1443 if (NUMA_BUILD && !did_zlc_setup) {
1444 /* we do zlc_setup after the first zone is tried */
1445 allowednodes = zlc_setup(zonelist, alloc_flags);
1449 } while (*(++z) != NULL);
1451 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1452 /* Disable zlc cache for second zonelist scan */
1460 * This is the 'heart' of the zoned buddy allocator.
1462 struct page * fastcall
1463 __alloc_pages(gfp_t gfp_mask, unsigned int order,
1464 struct zonelist *zonelist)
1466 const gfp_t wait = gfp_mask & __GFP_WAIT;
1469 struct reclaim_state reclaim_state;
1470 struct task_struct *p = current;
1473 int did_some_progress;
1475 might_sleep_if(wait);
1477 if (should_fail_alloc_page(gfp_mask, order))
1481 z = zonelist->zones; /* the list of zones suitable for gfp_mask */
1483 if (unlikely(*z == NULL)) {
1485 * Happens if we have an empty zonelist as a result of
1486 * GFP_THISNODE being used on a memoryless node
1491 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1492 zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
1497 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1498 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1499 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1500 * using a larger set of nodes after it has established that the
1501 * allowed per node queues are empty and that nodes are
1504 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
1507 for (z = zonelist->zones; *z; z++)
1508 wakeup_kswapd(*z, order);
1511 * OK, we're below the kswapd watermark and have kicked background
1512 * reclaim. Now things get more complex, so set up alloc_flags according
1513 * to how we want to proceed.
1515 * The caller may dip into page reserves a bit more if the caller
1516 * cannot run direct reclaim, or if the caller has realtime scheduling
1517 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1518 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1520 alloc_flags = ALLOC_WMARK_MIN;
1521 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
1522 alloc_flags |= ALLOC_HARDER;
1523 if (gfp_mask & __GFP_HIGH)
1524 alloc_flags |= ALLOC_HIGH;
1526 alloc_flags |= ALLOC_CPUSET;
1529 * Go through the zonelist again. Let __GFP_HIGH and allocations
1530 * coming from realtime tasks go deeper into reserves.
1532 * This is the last chance, in general, before the goto nopage.
1533 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1534 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1536 page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
1540 /* This allocation should allow future memory freeing. */
1543 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
1544 && !in_interrupt()) {
1545 if (!(gfp_mask & __GFP_NOMEMALLOC)) {
1547 /* go through the zonelist yet again, ignoring mins */
1548 page = get_page_from_freelist(gfp_mask, order,
1549 zonelist, ALLOC_NO_WATERMARKS);
1552 if (gfp_mask & __GFP_NOFAIL) {
1553 congestion_wait(WRITE, HZ/50);
1560 /* Atomic allocations - we can't balance anything */
1566 /* We now go into synchronous reclaim */
1567 cpuset_memory_pressure_bump();
1568 p->flags |= PF_MEMALLOC;
1569 reclaim_state.reclaimed_slab = 0;
1570 p->reclaim_state = &reclaim_state;
1572 did_some_progress = try_to_free_pages(zonelist->zones, order, gfp_mask);
1574 p->reclaim_state = NULL;
1575 p->flags &= ~PF_MEMALLOC;
1580 drain_all_local_pages();
1582 if (likely(did_some_progress)) {
1583 page = get_page_from_freelist(gfp_mask, order,
1584 zonelist, alloc_flags);
1587 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1589 * Go through the zonelist yet one more time, keep
1590 * very high watermark here, this is only to catch
1591 * a parallel oom killing, we must fail if we're still
1592 * under heavy pressure.
1594 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1595 zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1599 /* The OOM killer will not help higher order allocs so fail */
1600 if (order > PAGE_ALLOC_COSTLY_ORDER)
1603 out_of_memory(zonelist, gfp_mask, order);
1608 * Don't let big-order allocations loop unless the caller explicitly
1609 * requests that. Wait for some write requests to complete then retry.
1611 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1612 * <= 3, but that may not be true in other implementations.
1615 if (!(gfp_mask & __GFP_NORETRY)) {
1616 if ((order <= PAGE_ALLOC_COSTLY_ORDER) ||
1617 (gfp_mask & __GFP_REPEAT))
1619 if (gfp_mask & __GFP_NOFAIL)
1623 congestion_wait(WRITE, HZ/50);
1628 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
1629 printk(KERN_WARNING "%s: page allocation failure."
1630 " order:%d, mode:0x%x\n",
1631 p->comm, order, gfp_mask);
1639 EXPORT_SYMBOL(__alloc_pages);
1642 * Common helper functions.
1644 fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
1647 page = alloc_pages(gfp_mask, order);
1650 return (unsigned long) page_address(page);
1653 EXPORT_SYMBOL(__get_free_pages);
1655 fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
1660 * get_zeroed_page() returns a 32-bit address, which cannot represent
1663 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
1665 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1667 return (unsigned long) page_address(page);
1671 EXPORT_SYMBOL(get_zeroed_page);
1673 void __pagevec_free(struct pagevec *pvec)
1675 int i = pagevec_count(pvec);
1678 free_hot_cold_page(pvec->pages[i], pvec->cold);
1681 fastcall void __free_pages(struct page *page, unsigned int order)
1683 if (put_page_testzero(page)) {
1685 free_hot_page(page);
1687 __free_pages_ok(page, order);
1691 EXPORT_SYMBOL(__free_pages);
1693 fastcall void free_pages(unsigned long addr, unsigned int order)
1696 VM_BUG_ON(!virt_addr_valid((void *)addr));
1697 __free_pages(virt_to_page((void *)addr), order);
1701 EXPORT_SYMBOL(free_pages);
1703 static unsigned int nr_free_zone_pages(int offset)
1705 /* Just pick one node, since fallback list is circular */
1706 pg_data_t *pgdat = NODE_DATA(numa_node_id());
1707 unsigned int sum = 0;
1709 struct zonelist *zonelist = pgdat->node_zonelists + offset;
1710 struct zone **zonep = zonelist->zones;
1713 for (zone = *zonep++; zone; zone = *zonep++) {
1714 unsigned long size = zone->present_pages;
1715 unsigned long high = zone->pages_high;
1724 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1726 unsigned int nr_free_buffer_pages(void)
1728 return nr_free_zone_pages(gfp_zone(GFP_USER));
1730 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
1733 * Amount of free RAM allocatable within all zones
1735 unsigned int nr_free_pagecache_pages(void)
1737 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
1740 static inline void show_node(struct zone *zone)
1743 printk("Node %d ", zone_to_nid(zone));
1746 void si_meminfo(struct sysinfo *val)
1748 val->totalram = totalram_pages;
1750 val->freeram = global_page_state(NR_FREE_PAGES);
1751 val->bufferram = nr_blockdev_pages();
1752 val->totalhigh = totalhigh_pages;
1753 val->freehigh = nr_free_highpages();
1754 val->mem_unit = PAGE_SIZE;
1757 EXPORT_SYMBOL(si_meminfo);
1760 void si_meminfo_node(struct sysinfo *val, int nid)
1762 pg_data_t *pgdat = NODE_DATA(nid);
1764 val->totalram = pgdat->node_present_pages;
1765 val->freeram = node_page_state(nid, NR_FREE_PAGES);
1766 #ifdef CONFIG_HIGHMEM
1767 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1768 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
1774 val->mem_unit = PAGE_SIZE;
1778 #define K(x) ((x) << (PAGE_SHIFT-10))
1781 * Show free area list (used inside shift_scroll-lock stuff)
1782 * We also calculate the percentage fragmentation. We do this by counting the
1783 * memory on each free list with the exception of the first item on the list.
1785 void show_free_areas(void)
1790 for_each_zone(zone) {
1791 if (!populated_zone(zone))
1795 printk("%s per-cpu:\n", zone->name);
1797 for_each_online_cpu(cpu) {
1798 struct per_cpu_pageset *pageset;
1800 pageset = zone_pcp(zone, cpu);
1802 printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d "
1803 "Cold: hi:%5d, btch:%4d usd:%4d\n",
1804 cpu, pageset->pcp[0].high,
1805 pageset->pcp[0].batch, pageset->pcp[0].count,
1806 pageset->pcp[1].high, pageset->pcp[1].batch,
1807 pageset->pcp[1].count);
1811 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1812 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1813 global_page_state(NR_ACTIVE),
1814 global_page_state(NR_INACTIVE),
1815 global_page_state(NR_FILE_DIRTY),
1816 global_page_state(NR_WRITEBACK),
1817 global_page_state(NR_UNSTABLE_NFS),
1818 global_page_state(NR_FREE_PAGES),
1819 global_page_state(NR_SLAB_RECLAIMABLE) +
1820 global_page_state(NR_SLAB_UNRECLAIMABLE),
1821 global_page_state(NR_FILE_MAPPED),
1822 global_page_state(NR_PAGETABLE),
1823 global_page_state(NR_BOUNCE));
1825 for_each_zone(zone) {
1828 if (!populated_zone(zone))
1840 " pages_scanned:%lu"
1841 " all_unreclaimable? %s"
1844 K(zone_page_state(zone, NR_FREE_PAGES)),
1847 K(zone->pages_high),
1848 K(zone_page_state(zone, NR_ACTIVE)),
1849 K(zone_page_state(zone, NR_INACTIVE)),
1850 K(zone->present_pages),
1851 zone->pages_scanned,
1852 (zone->all_unreclaimable ? "yes" : "no")
1854 printk("lowmem_reserve[]:");
1855 for (i = 0; i < MAX_NR_ZONES; i++)
1856 printk(" %lu", zone->lowmem_reserve[i]);
1860 for_each_zone(zone) {
1861 unsigned long nr[MAX_ORDER], flags, order, total = 0;
1863 if (!populated_zone(zone))
1867 printk("%s: ", zone->name);
1869 spin_lock_irqsave(&zone->lock, flags);
1870 for (order = 0; order < MAX_ORDER; order++) {
1871 nr[order] = zone->free_area[order].nr_free;
1872 total += nr[order] << order;
1874 spin_unlock_irqrestore(&zone->lock, flags);
1875 for (order = 0; order < MAX_ORDER; order++)
1876 printk("%lu*%lukB ", nr[order], K(1UL) << order);
1877 printk("= %lukB\n", K(total));
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 zonelist->zones[nr_zones++] = zone;
1901 check_highest_zone(zone_type);
1904 } while (zone_type);
1911 * 0 = automatic detection of better ordering.
1912 * 1 = order by ([node] distance, -zonetype)
1913 * 2 = order by (-zonetype, [node] distance)
1915 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
1916 * the same zonelist. So only NUMA can configure this param.
1918 #define ZONELIST_ORDER_DEFAULT 0
1919 #define ZONELIST_ORDER_NODE 1
1920 #define ZONELIST_ORDER_ZONE 2
1922 /* zonelist order in the kernel.
1923 * set_zonelist_order() will set this to NODE or ZONE.
1925 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
1926 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
1930 /* The value user specified ....changed by config */
1931 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
1932 /* string for sysctl */
1933 #define NUMA_ZONELIST_ORDER_LEN 16
1934 char numa_zonelist_order[16] = "default";
1937 * interface for configure zonelist ordering.
1938 * command line option "numa_zonelist_order"
1939 * = "[dD]efault - default, automatic configuration.
1940 * = "[nN]ode - order by node locality, then by zone within node
1941 * = "[zZ]one - order by zone, then by locality within zone
1944 static int __parse_numa_zonelist_order(char *s)
1946 if (*s == 'd' || *s == 'D') {
1947 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
1948 } else if (*s == 'n' || *s == 'N') {
1949 user_zonelist_order = ZONELIST_ORDER_NODE;
1950 } else if (*s == 'z' || *s == 'Z') {
1951 user_zonelist_order = ZONELIST_ORDER_ZONE;
1954 "Ignoring invalid numa_zonelist_order value: "
1961 static __init int setup_numa_zonelist_order(char *s)
1964 return __parse_numa_zonelist_order(s);
1967 early_param("numa_zonelist_order", setup_numa_zonelist_order);
1970 * sysctl handler for numa_zonelist_order
1972 int numa_zonelist_order_handler(ctl_table *table, int write,
1973 struct file *file, void __user *buffer, size_t *length,
1976 char saved_string[NUMA_ZONELIST_ORDER_LEN];
1980 strncpy(saved_string, (char*)table->data,
1981 NUMA_ZONELIST_ORDER_LEN);
1982 ret = proc_dostring(table, write, file, buffer, length, ppos);
1986 int oldval = user_zonelist_order;
1987 if (__parse_numa_zonelist_order((char*)table->data)) {
1989 * bogus value. restore saved string
1991 strncpy((char*)table->data, saved_string,
1992 NUMA_ZONELIST_ORDER_LEN);
1993 user_zonelist_order = oldval;
1994 } else if (oldval != user_zonelist_order)
1995 build_all_zonelists();
2001 #define MAX_NODE_LOAD (num_online_nodes())
2002 static int node_load[MAX_NUMNODES];
2005 * find_next_best_node - find the next node that should appear in a given node's fallback list
2006 * @node: node whose fallback list we're appending
2007 * @used_node_mask: nodemask_t of already used nodes
2009 * We use a number of factors to determine which is the next node that should
2010 * appear on a given node's fallback list. The node should not have appeared
2011 * already in @node's fallback list, and it should be the next closest node
2012 * according to the distance array (which contains arbitrary distance values
2013 * from each node to each node in the system), and should also prefer nodes
2014 * with no CPUs, since presumably they'll have very little allocation pressure
2015 * on them otherwise.
2016 * It returns -1 if no node is found.
2018 static int find_next_best_node(int node, nodemask_t *used_node_mask)
2021 int min_val = INT_MAX;
2024 /* Use the local node if we haven't already */
2025 if (!node_isset(node, *used_node_mask)) {
2026 node_set(node, *used_node_mask);
2030 for_each_node_state(n, N_HIGH_MEMORY) {
2033 /* Don't want a node to appear more than once */
2034 if (node_isset(n, *used_node_mask))
2037 /* Use the distance array to find the distance */
2038 val = node_distance(node, n);
2040 /* Penalize nodes under us ("prefer the next node") */
2043 /* Give preference to headless and unused nodes */
2044 tmp = node_to_cpumask(n);
2045 if (!cpus_empty(tmp))
2046 val += PENALTY_FOR_NODE_WITH_CPUS;
2048 /* Slight preference for less loaded node */
2049 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2050 val += node_load[n];
2052 if (val < min_val) {
2059 node_set(best_node, *used_node_mask);
2066 * Build zonelists ordered by node and zones within node.
2067 * This results in maximum locality--normal zone overflows into local
2068 * DMA zone, if any--but risks exhausting DMA zone.
2070 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2074 struct zonelist *zonelist;
2076 for (i = 0; i < MAX_NR_ZONES; i++) {
2077 zonelist = pgdat->node_zonelists + i;
2078 for (j = 0; zonelist->zones[j] != NULL; j++)
2080 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
2081 zonelist->zones[j] = NULL;
2086 * Build gfp_thisnode zonelists
2088 static void build_thisnode_zonelists(pg_data_t *pgdat)
2092 struct zonelist *zonelist;
2094 for (i = 0; i < MAX_NR_ZONES; i++) {
2095 zonelist = pgdat->node_zonelists + MAX_NR_ZONES + i;
2096 j = build_zonelists_node(pgdat, zonelist, 0, i);
2097 zonelist->zones[j] = NULL;
2102 * Build zonelists ordered by zone and nodes within zones.
2103 * This results in conserving DMA zone[s] until all Normal memory is
2104 * exhausted, but results in overflowing to remote node while memory
2105 * may still exist in local DMA zone.
2107 static int node_order[MAX_NUMNODES];
2109 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2113 int zone_type; /* needs to be signed */
2115 struct zonelist *zonelist;
2117 for (i = 0; i < MAX_NR_ZONES; i++) {
2118 zonelist = pgdat->node_zonelists + i;
2120 for (zone_type = i; zone_type >= 0; zone_type--) {
2121 for (j = 0; j < nr_nodes; j++) {
2122 node = node_order[j];
2123 z = &NODE_DATA(node)->node_zones[zone_type];
2124 if (populated_zone(z)) {
2125 zonelist->zones[pos++] = z;
2126 check_highest_zone(zone_type);
2130 zonelist->zones[pos] = NULL;
2134 static int default_zonelist_order(void)
2137 unsigned long low_kmem_size,total_size;
2141 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2142 * If they are really small and used heavily, the system can fall
2143 * into OOM very easily.
2144 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2146 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2149 for_each_online_node(nid) {
2150 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2151 z = &NODE_DATA(nid)->node_zones[zone_type];
2152 if (populated_zone(z)) {
2153 if (zone_type < ZONE_NORMAL)
2154 low_kmem_size += z->present_pages;
2155 total_size += z->present_pages;
2159 if (!low_kmem_size || /* there are no DMA area. */
2160 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
2161 return ZONELIST_ORDER_NODE;
2163 * look into each node's config.
2164 * If there is a node whose DMA/DMA32 memory is very big area on
2165 * local memory, NODE_ORDER may be suitable.
2167 average_size = total_size /
2168 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2169 for_each_online_node(nid) {
2172 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2173 z = &NODE_DATA(nid)->node_zones[zone_type];
2174 if (populated_zone(z)) {
2175 if (zone_type < ZONE_NORMAL)
2176 low_kmem_size += z->present_pages;
2177 total_size += z->present_pages;
2180 if (low_kmem_size &&
2181 total_size > average_size && /* ignore small node */
2182 low_kmem_size > total_size * 70/100)
2183 return ZONELIST_ORDER_NODE;
2185 return ZONELIST_ORDER_ZONE;
2188 static void set_zonelist_order(void)
2190 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
2191 current_zonelist_order = default_zonelist_order();
2193 current_zonelist_order = user_zonelist_order;
2196 static void build_zonelists(pg_data_t *pgdat)
2200 nodemask_t used_mask;
2201 int local_node, prev_node;
2202 struct zonelist *zonelist;
2203 int order = current_zonelist_order;
2205 /* initialize zonelists */
2206 for (i = 0; i < MAX_ZONELISTS; i++) {
2207 zonelist = pgdat->node_zonelists + i;
2208 zonelist->zones[0] = NULL;
2211 /* NUMA-aware ordering of nodes */
2212 local_node = pgdat->node_id;
2213 load = num_online_nodes();
2214 prev_node = local_node;
2215 nodes_clear(used_mask);
2217 memset(node_load, 0, sizeof(node_load));
2218 memset(node_order, 0, sizeof(node_order));
2221 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2222 int distance = node_distance(local_node, node);
2225 * If another node is sufficiently far away then it is better
2226 * to reclaim pages in a zone before going off node.
2228 if (distance > RECLAIM_DISTANCE)
2229 zone_reclaim_mode = 1;
2232 * We don't want to pressure a particular node.
2233 * So adding penalty to the first node in same
2234 * distance group to make it round-robin.
2236 if (distance != node_distance(local_node, prev_node))
2237 node_load[node] = load;
2241 if (order == ZONELIST_ORDER_NODE)
2242 build_zonelists_in_node_order(pgdat, node);
2244 node_order[j++] = node; /* remember order */
2247 if (order == ZONELIST_ORDER_ZONE) {
2248 /* calculate node order -- i.e., DMA last! */
2249 build_zonelists_in_zone_order(pgdat, j);
2252 build_thisnode_zonelists(pgdat);
2255 /* Construct the zonelist performance cache - see further mmzone.h */
2256 static void build_zonelist_cache(pg_data_t *pgdat)
2260 for (i = 0; i < MAX_NR_ZONES; i++) {
2261 struct zonelist *zonelist;
2262 struct zonelist_cache *zlc;
2265 zonelist = pgdat->node_zonelists + i;
2266 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
2267 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2268 for (z = zonelist->zones; *z; z++)
2269 zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z);
2274 #else /* CONFIG_NUMA */
2276 static void set_zonelist_order(void)
2278 current_zonelist_order = ZONELIST_ORDER_ZONE;
2281 static void build_zonelists(pg_data_t *pgdat)
2283 int node, local_node;
2286 local_node = pgdat->node_id;
2287 for (i = 0; i < MAX_NR_ZONES; i++) {
2288 struct zonelist *zonelist;
2290 zonelist = pgdat->node_zonelists + i;
2292 j = build_zonelists_node(pgdat, zonelist, 0, i);
2294 * Now we build the zonelist so that it contains the zones
2295 * of all the other nodes.
2296 * We don't want to pressure a particular node, so when
2297 * building the zones for node N, we make sure that the
2298 * zones coming right after the local ones are those from
2299 * node N+1 (modulo N)
2301 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
2302 if (!node_online(node))
2304 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
2306 for (node = 0; node < local_node; node++) {
2307 if (!node_online(node))
2309 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
2312 zonelist->zones[j] = NULL;
2316 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2317 static void build_zonelist_cache(pg_data_t *pgdat)
2321 for (i = 0; i < MAX_NR_ZONES; i++)
2322 pgdat->node_zonelists[i].zlcache_ptr = NULL;
2325 #endif /* CONFIG_NUMA */
2327 /* return values int ....just for stop_machine_run() */
2328 static int __build_all_zonelists(void *dummy)
2332 for_each_online_node(nid) {
2333 pg_data_t *pgdat = NODE_DATA(nid);
2335 build_zonelists(pgdat);
2336 build_zonelist_cache(pgdat);
2341 void build_all_zonelists(void)
2343 set_zonelist_order();
2345 if (system_state == SYSTEM_BOOTING) {
2346 __build_all_zonelists(NULL);
2347 cpuset_init_current_mems_allowed();
2349 /* we have to stop all cpus to guaranntee there is no user
2351 stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
2352 /* cpuset refresh routine should be here */
2354 vm_total_pages = nr_free_pagecache_pages();
2356 * Disable grouping by mobility if the number of pages in the
2357 * system is too low to allow the mechanism to work. It would be
2358 * more accurate, but expensive to check per-zone. This check is
2359 * made on memory-hotadd so a system can start with mobility
2360 * disabled and enable it later
2362 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2363 page_group_by_mobility_disabled = 1;
2365 page_group_by_mobility_disabled = 0;
2367 printk("Built %i zonelists in %s order, mobility grouping %s. "
2368 "Total pages: %ld\n",
2370 zonelist_order_name[current_zonelist_order],
2371 page_group_by_mobility_disabled ? "off" : "on",
2374 printk("Policy zone: %s\n", zone_names[policy_zone]);
2379 * Helper functions to size the waitqueue hash table.
2380 * Essentially these want to choose hash table sizes sufficiently
2381 * large so that collisions trying to wait on pages are rare.
2382 * But in fact, the number of active page waitqueues on typical
2383 * systems is ridiculously low, less than 200. So this is even
2384 * conservative, even though it seems large.
2386 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2387 * waitqueues, i.e. the size of the waitq table given the number of pages.
2389 #define PAGES_PER_WAITQUEUE 256
2391 #ifndef CONFIG_MEMORY_HOTPLUG
2392 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2394 unsigned long size = 1;
2396 pages /= PAGES_PER_WAITQUEUE;
2398 while (size < pages)
2402 * Once we have dozens or even hundreds of threads sleeping
2403 * on IO we've got bigger problems than wait queue collision.
2404 * Limit the size of the wait table to a reasonable size.
2406 size = min(size, 4096UL);
2408 return max(size, 4UL);
2412 * A zone's size might be changed by hot-add, so it is not possible to determine
2413 * a suitable size for its wait_table. So we use the maximum size now.
2415 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2417 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2418 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2419 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2421 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2422 * or more by the traditional way. (See above). It equals:
2424 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2425 * ia64(16K page size) : = ( 8G + 4M)byte.
2426 * powerpc (64K page size) : = (32G +16M)byte.
2428 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2435 * This is an integer logarithm so that shifts can be used later
2436 * to extract the more random high bits from the multiplicative
2437 * hash function before the remainder is taken.
2439 static inline unsigned long wait_table_bits(unsigned long size)
2444 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2447 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2448 * of blocks reserved is based on zone->pages_min. The memory within the
2449 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2450 * higher will lead to a bigger reserve which will get freed as contiguous
2451 * blocks as reclaim kicks in
2453 static void setup_zone_migrate_reserve(struct zone *zone)
2455 unsigned long start_pfn, pfn, end_pfn;
2457 unsigned long reserve, block_migratetype;
2459 /* Get the start pfn, end pfn and the number of blocks to reserve */
2460 start_pfn = zone->zone_start_pfn;
2461 end_pfn = start_pfn + zone->spanned_pages;
2462 reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
2465 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2466 if (!pfn_valid(pfn))
2468 page = pfn_to_page(pfn);
2470 /* Blocks with reserved pages will never free, skip them. */
2471 if (PageReserved(page))
2474 block_migratetype = get_pageblock_migratetype(page);
2476 /* If this block is reserved, account for it */
2477 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
2482 /* Suitable for reserving if this block is movable */
2483 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
2484 set_pageblock_migratetype(page, MIGRATE_RESERVE);
2485 move_freepages_block(zone, page, MIGRATE_RESERVE);
2491 * If the reserve is met and this is a previous reserved block,
2494 if (block_migratetype == MIGRATE_RESERVE) {
2495 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2496 move_freepages_block(zone, page, MIGRATE_MOVABLE);
2502 * Initially all pages are reserved - free ones are freed
2503 * up by free_all_bootmem() once the early boot process is
2504 * done. Non-atomic initialization, single-pass.
2506 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
2507 unsigned long start_pfn, enum memmap_context context)
2510 unsigned long end_pfn = start_pfn + size;
2513 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
2515 * There can be holes in boot-time mem_map[]s
2516 * handed to this function. They do not
2517 * exist on hotplugged memory.
2519 if (context == MEMMAP_EARLY) {
2520 if (!early_pfn_valid(pfn))
2522 if (!early_pfn_in_nid(pfn, nid))
2525 page = pfn_to_page(pfn);
2526 set_page_links(page, zone, nid, pfn);
2527 init_page_count(page);
2528 reset_page_mapcount(page);
2529 SetPageReserved(page);
2532 * Mark the block movable so that blocks are reserved for
2533 * movable at startup. This will force kernel allocations
2534 * to reserve their blocks rather than leaking throughout
2535 * the address space during boot when many long-lived
2536 * kernel allocations are made. Later some blocks near
2537 * the start are marked MIGRATE_RESERVE by
2538 * setup_zone_migrate_reserve()
2540 if ((pfn & (pageblock_nr_pages-1)))
2541 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2543 INIT_LIST_HEAD(&page->lru);
2544 #ifdef WANT_PAGE_VIRTUAL
2545 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2546 if (!is_highmem_idx(zone))
2547 set_page_address(page, __va(pfn << PAGE_SHIFT));
2552 static void __meminit zone_init_free_lists(struct pglist_data *pgdat,
2553 struct zone *zone, unsigned long size)
2556 for_each_migratetype_order(order, t) {
2557 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
2558 zone->free_area[order].nr_free = 0;
2562 #ifndef __HAVE_ARCH_MEMMAP_INIT
2563 #define memmap_init(size, nid, zone, start_pfn) \
2564 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2567 static int __devinit zone_batchsize(struct zone *zone)
2572 * The per-cpu-pages pools are set to around 1000th of the
2573 * size of the zone. But no more than 1/2 of a meg.
2575 * OK, so we don't know how big the cache is. So guess.
2577 batch = zone->present_pages / 1024;
2578 if (batch * PAGE_SIZE > 512 * 1024)
2579 batch = (512 * 1024) / PAGE_SIZE;
2580 batch /= 4; /* We effectively *= 4 below */
2585 * Clamp the batch to a 2^n - 1 value. Having a power
2586 * of 2 value was found to be more likely to have
2587 * suboptimal cache aliasing properties in some cases.
2589 * For example if 2 tasks are alternately allocating
2590 * batches of pages, one task can end up with a lot
2591 * of pages of one half of the possible page colors
2592 * and the other with pages of the other colors.
2594 batch = (1 << (fls(batch + batch/2)-1)) - 1;
2599 inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2601 struct per_cpu_pages *pcp;
2603 memset(p, 0, sizeof(*p));
2605 pcp = &p->pcp[0]; /* hot */
2607 pcp->high = 6 * batch;
2608 pcp->batch = max(1UL, 1 * batch);
2609 INIT_LIST_HEAD(&pcp->list);
2611 pcp = &p->pcp[1]; /* cold*/
2613 pcp->high = 2 * batch;
2614 pcp->batch = max(1UL, batch/2);
2615 INIT_LIST_HEAD(&pcp->list);
2619 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2620 * to the value high for the pageset p.
2623 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
2626 struct per_cpu_pages *pcp;
2628 pcp = &p->pcp[0]; /* hot list */
2630 pcp->batch = max(1UL, high/4);
2631 if ((high/4) > (PAGE_SHIFT * 8))
2632 pcp->batch = PAGE_SHIFT * 8;
2638 * Boot pageset table. One per cpu which is going to be used for all
2639 * zones and all nodes. The parameters will be set in such a way
2640 * that an item put on a list will immediately be handed over to
2641 * the buddy list. This is safe since pageset manipulation is done
2642 * with interrupts disabled.
2644 * Some NUMA counter updates may also be caught by the boot pagesets.
2646 * The boot_pagesets must be kept even after bootup is complete for
2647 * unused processors and/or zones. They do play a role for bootstrapping
2648 * hotplugged processors.
2650 * zoneinfo_show() and maybe other functions do
2651 * not check if the processor is online before following the pageset pointer.
2652 * Other parts of the kernel may not check if the zone is available.
2654 static struct per_cpu_pageset boot_pageset[NR_CPUS];
2657 * Dynamically allocate memory for the
2658 * per cpu pageset array in struct zone.
2660 static int __cpuinit process_zones(int cpu)
2662 struct zone *zone, *dzone;
2663 int node = cpu_to_node(cpu);
2665 node_set_state(node, N_CPU); /* this node has a cpu */
2667 for_each_zone(zone) {
2669 if (!populated_zone(zone))
2672 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2674 if (!zone_pcp(zone, cpu))
2677 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2679 if (percpu_pagelist_fraction)
2680 setup_pagelist_highmark(zone_pcp(zone, cpu),
2681 (zone->present_pages / percpu_pagelist_fraction));
2686 for_each_zone(dzone) {
2687 if (!populated_zone(dzone))
2691 kfree(zone_pcp(dzone, cpu));
2692 zone_pcp(dzone, cpu) = NULL;
2697 static inline void free_zone_pagesets(int cpu)
2701 for_each_zone(zone) {
2702 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
2704 /* Free per_cpu_pageset if it is slab allocated */
2705 if (pset != &boot_pageset[cpu])
2707 zone_pcp(zone, cpu) = NULL;
2711 static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2712 unsigned long action,
2715 int cpu = (long)hcpu;
2716 int ret = NOTIFY_OK;
2719 case CPU_UP_PREPARE:
2720 case CPU_UP_PREPARE_FROZEN:
2721 if (process_zones(cpu))
2724 case CPU_UP_CANCELED:
2725 case CPU_UP_CANCELED_FROZEN:
2727 case CPU_DEAD_FROZEN:
2728 free_zone_pagesets(cpu);
2736 static struct notifier_block __cpuinitdata pageset_notifier =
2737 { &pageset_cpuup_callback, NULL, 0 };
2739 void __init setup_per_cpu_pageset(void)
2743 /* Initialize per_cpu_pageset for cpu 0.
2744 * A cpuup callback will do this for every cpu
2745 * as it comes online
2747 err = process_zones(smp_processor_id());
2749 register_cpu_notifier(&pageset_notifier);
2754 static noinline __init_refok
2755 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2758 struct pglist_data *pgdat = zone->zone_pgdat;
2762 * The per-page waitqueue mechanism uses hashed waitqueues
2765 zone->wait_table_hash_nr_entries =
2766 wait_table_hash_nr_entries(zone_size_pages);
2767 zone->wait_table_bits =
2768 wait_table_bits(zone->wait_table_hash_nr_entries);
2769 alloc_size = zone->wait_table_hash_nr_entries
2770 * sizeof(wait_queue_head_t);
2772 if (system_state == SYSTEM_BOOTING) {
2773 zone->wait_table = (wait_queue_head_t *)
2774 alloc_bootmem_node(pgdat, alloc_size);
2777 * This case means that a zone whose size was 0 gets new memory
2778 * via memory hot-add.
2779 * But it may be the case that a new node was hot-added. In
2780 * this case vmalloc() will not be able to use this new node's
2781 * memory - this wait_table must be initialized to use this new
2782 * node itself as well.
2783 * To use this new node's memory, further consideration will be
2786 zone->wait_table = vmalloc(alloc_size);
2788 if (!zone->wait_table)
2791 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2792 init_waitqueue_head(zone->wait_table + i);
2797 static __meminit void zone_pcp_init(struct zone *zone)
2800 unsigned long batch = zone_batchsize(zone);
2802 for (cpu = 0; cpu < NR_CPUS; cpu++) {
2804 /* Early boot. Slab allocator not functional yet */
2805 zone_pcp(zone, cpu) = &boot_pageset[cpu];
2806 setup_pageset(&boot_pageset[cpu],0);
2808 setup_pageset(zone_pcp(zone,cpu), batch);
2811 if (zone->present_pages)
2812 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
2813 zone->name, zone->present_pages, batch);
2816 __meminit int init_currently_empty_zone(struct zone *zone,
2817 unsigned long zone_start_pfn,
2819 enum memmap_context context)
2821 struct pglist_data *pgdat = zone->zone_pgdat;
2823 ret = zone_wait_table_init(zone, size);
2826 pgdat->nr_zones = zone_idx(zone) + 1;
2828 zone->zone_start_pfn = zone_start_pfn;
2830 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);
2832 zone_init_free_lists(pgdat, zone, zone->spanned_pages);
2837 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2839 * Basic iterator support. Return the first range of PFNs for a node
2840 * Note: nid == MAX_NUMNODES returns first region regardless of node
2842 static int __meminit first_active_region_index_in_nid(int nid)
2846 for (i = 0; i < nr_nodemap_entries; i++)
2847 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
2854 * Basic iterator support. Return the next active range of PFNs for a node
2855 * Note: nid == MAX_NUMNODES returns next region regardles of node
2857 static int __meminit next_active_region_index_in_nid(int index, int nid)
2859 for (index = index + 1; index < nr_nodemap_entries; index++)
2860 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
2866 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2868 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2869 * Architectures may implement their own version but if add_active_range()
2870 * was used and there are no special requirements, this is a convenient
2873 int __meminit early_pfn_to_nid(unsigned long pfn)
2877 for (i = 0; i < nr_nodemap_entries; i++) {
2878 unsigned long start_pfn = early_node_map[i].start_pfn;
2879 unsigned long end_pfn = early_node_map[i].end_pfn;
2881 if (start_pfn <= pfn && pfn < end_pfn)
2882 return early_node_map[i].nid;
2887 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2889 /* Basic iterator support to walk early_node_map[] */
2890 #define for_each_active_range_index_in_nid(i, nid) \
2891 for (i = first_active_region_index_in_nid(nid); i != -1; \
2892 i = next_active_region_index_in_nid(i, nid))
2895 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2896 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2897 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2899 * If an architecture guarantees that all ranges registered with
2900 * add_active_ranges() contain no holes and may be freed, this
2901 * this function may be used instead of calling free_bootmem() manually.
2903 void __init free_bootmem_with_active_regions(int nid,
2904 unsigned long max_low_pfn)
2908 for_each_active_range_index_in_nid(i, nid) {
2909 unsigned long size_pages = 0;
2910 unsigned long end_pfn = early_node_map[i].end_pfn;
2912 if (early_node_map[i].start_pfn >= max_low_pfn)
2915 if (end_pfn > max_low_pfn)
2916 end_pfn = max_low_pfn;
2918 size_pages = end_pfn - early_node_map[i].start_pfn;
2919 free_bootmem_node(NODE_DATA(early_node_map[i].nid),
2920 PFN_PHYS(early_node_map[i].start_pfn),
2921 size_pages << PAGE_SHIFT);
2926 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2927 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2929 * If an architecture guarantees that all ranges registered with
2930 * add_active_ranges() contain no holes and may be freed, this
2931 * function may be used instead of calling memory_present() manually.
2933 void __init sparse_memory_present_with_active_regions(int nid)
2937 for_each_active_range_index_in_nid(i, nid)
2938 memory_present(early_node_map[i].nid,
2939 early_node_map[i].start_pfn,
2940 early_node_map[i].end_pfn);
2944 * push_node_boundaries - Push node boundaries to at least the requested boundary
2945 * @nid: The nid of the node to push the boundary for
2946 * @start_pfn: The start pfn of the node
2947 * @end_pfn: The end pfn of the node
2949 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2950 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2951 * be hotplugged even though no physical memory exists. This function allows
2952 * an arch to push out the node boundaries so mem_map is allocated that can
2955 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2956 void __init push_node_boundaries(unsigned int nid,
2957 unsigned long start_pfn, unsigned long end_pfn)
2959 printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
2960 nid, start_pfn, end_pfn);
2962 /* Initialise the boundary for this node if necessary */
2963 if (node_boundary_end_pfn[nid] == 0)
2964 node_boundary_start_pfn[nid] = -1UL;
2966 /* Update the boundaries */
2967 if (node_boundary_start_pfn[nid] > start_pfn)
2968 node_boundary_start_pfn[nid] = start_pfn;
2969 if (node_boundary_end_pfn[nid] < end_pfn)
2970 node_boundary_end_pfn[nid] = end_pfn;
2973 /* If necessary, push the node boundary out for reserve hotadd */
2974 static void __meminit account_node_boundary(unsigned int nid,
2975 unsigned long *start_pfn, unsigned long *end_pfn)
2977 printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
2978 nid, *start_pfn, *end_pfn);
2980 /* Return if boundary information has not been provided */
2981 if (node_boundary_end_pfn[nid] == 0)
2984 /* Check the boundaries and update if necessary */
2985 if (node_boundary_start_pfn[nid] < *start_pfn)
2986 *start_pfn = node_boundary_start_pfn[nid];
2987 if (node_boundary_end_pfn[nid] > *end_pfn)
2988 *end_pfn = node_boundary_end_pfn[nid];
2991 void __init push_node_boundaries(unsigned int nid,
2992 unsigned long start_pfn, unsigned long end_pfn) {}
2994 static void __meminit account_node_boundary(unsigned int nid,
2995 unsigned long *start_pfn, unsigned long *end_pfn) {}
3000 * get_pfn_range_for_nid - Return the start and end page frames for a node
3001 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3002 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3003 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3005 * It returns the start and end page frame of a node based on information
3006 * provided by an arch calling add_active_range(). If called for a node
3007 * with no available memory, a warning is printed and the start and end
3010 void __meminit get_pfn_range_for_nid(unsigned int nid,
3011 unsigned long *start_pfn, unsigned long *end_pfn)
3017 for_each_active_range_index_in_nid(i, nid) {
3018 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
3019 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
3022 if (*start_pfn == -1UL)
3025 /* Push the node boundaries out if requested */
3026 account_node_boundary(nid, start_pfn, end_pfn);
3030 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3031 * assumption is made that zones within a node are ordered in monotonic
3032 * increasing memory addresses so that the "highest" populated zone is used
3034 void __init find_usable_zone_for_movable(void)
3037 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
3038 if (zone_index == ZONE_MOVABLE)
3041 if (arch_zone_highest_possible_pfn[zone_index] >
3042 arch_zone_lowest_possible_pfn[zone_index])
3046 VM_BUG_ON(zone_index == -1);
3047 movable_zone = zone_index;
3051 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3052 * because it is sized independant of architecture. Unlike the other zones,
3053 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3054 * in each node depending on the size of each node and how evenly kernelcore
3055 * is distributed. This helper function adjusts the zone ranges
3056 * provided by the architecture for a given node by using the end of the
3057 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3058 * zones within a node are in order of monotonic increases memory addresses
3060 void __meminit adjust_zone_range_for_zone_movable(int nid,
3061 unsigned long zone_type,
3062 unsigned long node_start_pfn,
3063 unsigned long node_end_pfn,
3064 unsigned long *zone_start_pfn,
3065 unsigned long *zone_end_pfn)
3067 /* Only adjust if ZONE_MOVABLE is on this node */
3068 if (zone_movable_pfn[nid]) {
3069 /* Size ZONE_MOVABLE */
3070 if (zone_type == ZONE_MOVABLE) {
3071 *zone_start_pfn = zone_movable_pfn[nid];
3072 *zone_end_pfn = min(node_end_pfn,
3073 arch_zone_highest_possible_pfn[movable_zone]);
3075 /* Adjust for ZONE_MOVABLE starting within this range */
3076 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
3077 *zone_end_pfn > zone_movable_pfn[nid]) {
3078 *zone_end_pfn = zone_movable_pfn[nid];
3080 /* Check if this whole range is within ZONE_MOVABLE */
3081 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
3082 *zone_start_pfn = *zone_end_pfn;
3087 * Return the number of pages a zone spans in a node, including holes
3088 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3090 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3091 unsigned long zone_type,
3092 unsigned long *ignored)
3094 unsigned long node_start_pfn, node_end_pfn;
3095 unsigned long zone_start_pfn, zone_end_pfn;
3097 /* Get the start and end of the node and zone */
3098 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3099 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
3100 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
3101 adjust_zone_range_for_zone_movable(nid, zone_type,
3102 node_start_pfn, node_end_pfn,
3103 &zone_start_pfn, &zone_end_pfn);
3105 /* Check that this node has pages within the zone's required range */
3106 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
3109 /* Move the zone boundaries inside the node if necessary */
3110 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
3111 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
3113 /* Return the spanned pages */
3114 return zone_end_pfn - zone_start_pfn;
3118 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3119 * then all holes in the requested range will be accounted for.
3121 unsigned long __meminit __absent_pages_in_range(int nid,
3122 unsigned long range_start_pfn,
3123 unsigned long range_end_pfn)
3126 unsigned long prev_end_pfn = 0, hole_pages = 0;
3127 unsigned long start_pfn;
3129 /* Find the end_pfn of the first active range of pfns in the node */
3130 i = first_active_region_index_in_nid(nid);
3134 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3136 /* Account for ranges before physical memory on this node */
3137 if (early_node_map[i].start_pfn > range_start_pfn)
3138 hole_pages = prev_end_pfn - range_start_pfn;
3140 /* Find all holes for the zone within the node */
3141 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
3143 /* No need to continue if prev_end_pfn is outside the zone */
3144 if (prev_end_pfn >= range_end_pfn)
3147 /* Make sure the end of the zone is not within the hole */
3148 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3149 prev_end_pfn = max(prev_end_pfn, range_start_pfn);
3151 /* Update the hole size cound and move on */
3152 if (start_pfn > range_start_pfn) {
3153 BUG_ON(prev_end_pfn > start_pfn);
3154 hole_pages += start_pfn - prev_end_pfn;
3156 prev_end_pfn = early_node_map[i].end_pfn;
3159 /* Account for ranges past physical memory on this node */
3160 if (range_end_pfn > prev_end_pfn)
3161 hole_pages += range_end_pfn -
3162 max(range_start_pfn, prev_end_pfn);
3168 * absent_pages_in_range - Return number of page frames in holes within a range
3169 * @start_pfn: The start PFN to start searching for holes
3170 * @end_pfn: The end PFN to stop searching for holes
3172 * It returns the number of pages frames in memory holes within a range.
3174 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
3175 unsigned long end_pfn)
3177 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
3180 /* Return the number of page frames in holes in a zone on a node */
3181 static unsigned long __meminit zone_absent_pages_in_node(int nid,
3182 unsigned long zone_type,
3183 unsigned long *ignored)
3185 unsigned long node_start_pfn, node_end_pfn;
3186 unsigned long zone_start_pfn, zone_end_pfn;
3188 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3189 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
3191 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
3194 adjust_zone_range_for_zone_movable(nid, zone_type,
3195 node_start_pfn, node_end_pfn,
3196 &zone_start_pfn, &zone_end_pfn);
3197 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3201 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3202 unsigned long zone_type,
3203 unsigned long *zones_size)
3205 return zones_size[zone_type];
3208 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3209 unsigned long zone_type,
3210 unsigned long *zholes_size)
3215 return zholes_size[zone_type];
3220 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3221 unsigned long *zones_size, unsigned long *zholes_size)
3223 unsigned long realtotalpages, totalpages = 0;
3226 for (i = 0; i < MAX_NR_ZONES; i++)
3227 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
3229 pgdat->node_spanned_pages = totalpages;
3231 realtotalpages = totalpages;
3232 for (i = 0; i < MAX_NR_ZONES; i++)
3234 zone_absent_pages_in_node(pgdat->node_id, i,
3236 pgdat->node_present_pages = realtotalpages;
3237 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
3241 #ifndef CONFIG_SPARSEMEM
3243 * Calculate the size of the zone->blockflags rounded to an unsigned long
3244 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3245 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3246 * round what is now in bits to nearest long in bits, then return it in
3249 static unsigned long __init usemap_size(unsigned long zonesize)
3251 unsigned long usemapsize;
3253 usemapsize = roundup(zonesize, pageblock_nr_pages);
3254 usemapsize = usemapsize >> pageblock_order;
3255 usemapsize *= NR_PAGEBLOCK_BITS;
3256 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
3258 return usemapsize / 8;
3261 static void __init setup_usemap(struct pglist_data *pgdat,
3262 struct zone *zone, unsigned long zonesize)
3264 unsigned long usemapsize = usemap_size(zonesize);
3265 zone->pageblock_flags = NULL;
3267 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
3268 memset(zone->pageblock_flags, 0, usemapsize);
3272 static void inline setup_usemap(struct pglist_data *pgdat,
3273 struct zone *zone, unsigned long zonesize) {}
3274 #endif /* CONFIG_SPARSEMEM */
3276 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3277 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3278 static inline void __init set_pageblock_order(unsigned int order)
3280 /* Check that pageblock_nr_pages has not already been setup */
3281 if (pageblock_order)
3285 * Assume the largest contiguous order of interest is a huge page.
3286 * This value may be variable depending on boot parameters on IA64
3288 pageblock_order = order;
3290 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3292 /* Defined this way to avoid accidently referencing HUGETLB_PAGE_ORDER */
3293 #define set_pageblock_order(x) do {} while (0)
3295 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3298 * Set up the zone data structures:
3299 * - mark all pages reserved
3300 * - mark all memory queues empty
3301 * - clear the memory bitmaps
3303 static void __meminit free_area_init_core(struct pglist_data *pgdat,
3304 unsigned long *zones_size, unsigned long *zholes_size)
3307 int nid = pgdat->node_id;
3308 unsigned long zone_start_pfn = pgdat->node_start_pfn;
3311 pgdat_resize_init(pgdat);
3312 pgdat->nr_zones = 0;
3313 init_waitqueue_head(&pgdat->kswapd_wait);
3314 pgdat->kswapd_max_order = 0;
3316 for (j = 0; j < MAX_NR_ZONES; j++) {
3317 struct zone *zone = pgdat->node_zones + j;
3318 unsigned long size, realsize, memmap_pages;
3320 size = zone_spanned_pages_in_node(nid, j, zones_size);
3321 realsize = size - zone_absent_pages_in_node(nid, j,
3325 * Adjust realsize so that it accounts for how much memory
3326 * is used by this zone for memmap. This affects the watermark
3327 * and per-cpu initialisations
3329 memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT;
3330 if (realsize >= memmap_pages) {
3331 realsize -= memmap_pages;
3333 " %s zone: %lu pages used for memmap\n",
3334 zone_names[j], memmap_pages);
3337 " %s zone: %lu pages exceeds realsize %lu\n",
3338 zone_names[j], memmap_pages, realsize);
3340 /* Account for reserved pages */
3341 if (j == 0 && realsize > dma_reserve) {
3342 realsize -= dma_reserve;
3343 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
3344 zone_names[0], dma_reserve);
3347 if (!is_highmem_idx(j))
3348 nr_kernel_pages += realsize;
3349 nr_all_pages += realsize;
3351 zone->spanned_pages = size;
3352 zone->present_pages = realsize;
3355 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3357 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3359 zone->name = zone_names[j];
3360 spin_lock_init(&zone->lock);
3361 spin_lock_init(&zone->lru_lock);
3362 zone_seqlock_init(zone);
3363 zone->zone_pgdat = pgdat;
3365 zone->prev_priority = DEF_PRIORITY;
3367 zone_pcp_init(zone);
3368 INIT_LIST_HEAD(&zone->active_list);
3369 INIT_LIST_HEAD(&zone->inactive_list);
3370 zone->nr_scan_active = 0;
3371 zone->nr_scan_inactive = 0;
3372 zap_zone_vm_stats(zone);
3373 atomic_set(&zone->reclaim_in_progress, 0);
3377 set_pageblock_order(HUGETLB_PAGE_ORDER);
3378 setup_usemap(pgdat, zone, size);
3379 ret = init_currently_empty_zone(zone, zone_start_pfn,
3380 size, MEMMAP_EARLY);
3382 zone_start_pfn += size;
3386 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
3388 /* Skip empty nodes */
3389 if (!pgdat->node_spanned_pages)
3392 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3393 /* ia64 gets its own node_mem_map, before this, without bootmem */
3394 if (!pgdat->node_mem_map) {
3395 unsigned long size, start, end;
3399 * The zone's endpoints aren't required to be MAX_ORDER
3400 * aligned but the node_mem_map endpoints must be in order
3401 * for the buddy allocator to function correctly.
3403 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
3404 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
3405 end = ALIGN(end, MAX_ORDER_NR_PAGES);
3406 size = (end - start) * sizeof(struct page);
3407 map = alloc_remap(pgdat->node_id, size);
3409 map = alloc_bootmem_node(pgdat, size);
3410 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
3412 #ifndef CONFIG_NEED_MULTIPLE_NODES
3414 * With no DISCONTIG, the global mem_map is just set as node 0's
3416 if (pgdat == NODE_DATA(0)) {
3417 mem_map = NODE_DATA(0)->node_mem_map;
3418 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3419 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3420 mem_map -= pgdat->node_start_pfn;
3421 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3424 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3427 void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
3428 unsigned long *zones_size, unsigned long node_start_pfn,
3429 unsigned long *zholes_size)
3431 pgdat->node_id = nid;
3432 pgdat->node_start_pfn = node_start_pfn;
3433 calculate_node_totalpages(pgdat, zones_size, zholes_size);
3435 alloc_node_mem_map(pgdat);
3437 free_area_init_core(pgdat, zones_size, zholes_size);
3440 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3442 #if MAX_NUMNODES > 1
3444 * Figure out the number of possible node ids.
3446 static void __init setup_nr_node_ids(void)
3449 unsigned int highest = 0;
3451 for_each_node_mask(node, node_possible_map)
3453 nr_node_ids = highest + 1;
3456 static inline void setup_nr_node_ids(void)
3462 * add_active_range - Register a range of PFNs backed by physical memory
3463 * @nid: The node ID the range resides on
3464 * @start_pfn: The start PFN of the available physical memory
3465 * @end_pfn: The end PFN of the available physical memory
3467 * These ranges are stored in an early_node_map[] and later used by
3468 * free_area_init_nodes() to calculate zone sizes and holes. If the
3469 * range spans a memory hole, it is up to the architecture to ensure
3470 * the memory is not freed by the bootmem allocator. If possible
3471 * the range being registered will be merged with existing ranges.
3473 void __init add_active_range(unsigned int nid, unsigned long start_pfn,
3474 unsigned long end_pfn)
3478 printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
3479 "%d entries of %d used\n",
3480 nid, start_pfn, end_pfn,
3481 nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3483 /* Merge with existing active regions if possible */
3484 for (i = 0; i < nr_nodemap_entries; i++) {
3485 if (early_node_map[i].nid != nid)
3488 /* Skip if an existing region covers this new one */
3489 if (start_pfn >= early_node_map[i].start_pfn &&
3490 end_pfn <= early_node_map[i].end_pfn)
3493 /* Merge forward if suitable */
3494 if (start_pfn <= early_node_map[i].end_pfn &&
3495 end_pfn > early_node_map[i].end_pfn) {
3496 early_node_map[i].end_pfn = end_pfn;
3500 /* Merge backward if suitable */
3501 if (start_pfn < early_node_map[i].end_pfn &&
3502 end_pfn >= early_node_map[i].start_pfn) {
3503 early_node_map[i].start_pfn = start_pfn;
3508 /* Check that early_node_map is large enough */
3509 if (i >= MAX_ACTIVE_REGIONS) {
3510 printk(KERN_CRIT "More than %d memory regions, truncating\n",
3511 MAX_ACTIVE_REGIONS);
3515 early_node_map[i].nid = nid;
3516 early_node_map[i].start_pfn = start_pfn;
3517 early_node_map[i].end_pfn = end_pfn;
3518 nr_nodemap_entries = i + 1;
3522 * shrink_active_range - Shrink an existing registered range of PFNs
3523 * @nid: The node id the range is on that should be shrunk
3524 * @old_end_pfn: The old end PFN of the range
3525 * @new_end_pfn: The new PFN of the range
3527 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3528 * The map is kept at the end physical page range that has already been
3529 * registered with add_active_range(). This function allows an arch to shrink
3530 * an existing registered range.
3532 void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
3533 unsigned long new_end_pfn)
3537 /* Find the old active region end and shrink */
3538 for_each_active_range_index_in_nid(i, nid)
3539 if (early_node_map[i].end_pfn == old_end_pfn) {
3540 early_node_map[i].end_pfn = new_end_pfn;
3546 * remove_all_active_ranges - Remove all currently registered regions
3548 * During discovery, it may be found that a table like SRAT is invalid
3549 * and an alternative discovery method must be used. This function removes
3550 * all currently registered regions.
3552 void __init remove_all_active_ranges(void)
3554 memset(early_node_map, 0, sizeof(early_node_map));
3555 nr_nodemap_entries = 0;
3556 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3557 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
3558 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
3559 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3562 /* Compare two active node_active_regions */
3563 static int __init cmp_node_active_region(const void *a, const void *b)
3565 struct node_active_region *arange = (struct node_active_region *)a;
3566 struct node_active_region *brange = (struct node_active_region *)b;
3568 /* Done this way to avoid overflows */
3569 if (arange->start_pfn > brange->start_pfn)
3571 if (arange->start_pfn < brange->start_pfn)
3577 /* sort the node_map by start_pfn */
3578 static void __init sort_node_map(void)
3580 sort(early_node_map, (size_t)nr_nodemap_entries,
3581 sizeof(struct node_active_region),
3582 cmp_node_active_region, NULL);
3585 /* Find the lowest pfn for a node */
3586 unsigned long __init find_min_pfn_for_node(unsigned long nid)
3589 unsigned long min_pfn = ULONG_MAX;
3591 /* Assuming a sorted map, the first range found has the starting pfn */
3592 for_each_active_range_index_in_nid(i, nid)
3593 min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3595 if (min_pfn == ULONG_MAX) {
3597 "Could not find start_pfn for node %lu\n", nid);
3605 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3607 * It returns the minimum PFN based on information provided via
3608 * add_active_range().
3610 unsigned long __init find_min_pfn_with_active_regions(void)
3612 return find_min_pfn_for_node(MAX_NUMNODES);
3616 * find_max_pfn_with_active_regions - Find the maximum PFN registered
3618 * It returns the maximum PFN based on information provided via
3619 * add_active_range().
3621 unsigned long __init find_max_pfn_with_active_regions(void)
3624 unsigned long max_pfn = 0;
3626 for (i = 0; i < nr_nodemap_entries; i++)
3627 max_pfn = max(max_pfn, early_node_map[i].end_pfn);
3633 * early_calculate_totalpages()
3634 * Sum pages in active regions for movable zone.
3635 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3637 static unsigned long __init early_calculate_totalpages(void)
3640 unsigned long totalpages = 0;
3642 for (i = 0; i < nr_nodemap_entries; i++) {
3643 unsigned long pages = early_node_map[i].end_pfn -
3644 early_node_map[i].start_pfn;
3645 totalpages += pages;
3647 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
3653 * Find the PFN the Movable zone begins in each node. Kernel memory
3654 * is spread evenly between nodes as long as the nodes have enough
3655 * memory. When they don't, some nodes will have more kernelcore than
3658 void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
3661 unsigned long usable_startpfn;
3662 unsigned long kernelcore_node, kernelcore_remaining;
3663 unsigned long totalpages = early_calculate_totalpages();
3664 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
3667 * If movablecore was specified, calculate what size of
3668 * kernelcore that corresponds so that memory usable for
3669 * any allocation type is evenly spread. If both kernelcore
3670 * and movablecore are specified, then the value of kernelcore
3671 * will be used for required_kernelcore if it's greater than
3672 * what movablecore would have allowed.
3674 if (required_movablecore) {
3675 unsigned long corepages;
3678 * Round-up so that ZONE_MOVABLE is at least as large as what
3679 * was requested by the user
3681 required_movablecore =
3682 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
3683 corepages = totalpages - required_movablecore;
3685 required_kernelcore = max(required_kernelcore, corepages);
3688 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3689 if (!required_kernelcore)
3692 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3693 find_usable_zone_for_movable();
3694 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
3697 /* Spread kernelcore memory as evenly as possible throughout nodes */
3698 kernelcore_node = required_kernelcore / usable_nodes;
3699 for_each_node_state(nid, N_HIGH_MEMORY) {
3701 * Recalculate kernelcore_node if the division per node
3702 * now exceeds what is necessary to satisfy the requested
3703 * amount of memory for the kernel
3705 if (required_kernelcore < kernelcore_node)
3706 kernelcore_node = required_kernelcore / usable_nodes;
3709 * As the map is walked, we track how much memory is usable
3710 * by the kernel using kernelcore_remaining. When it is
3711 * 0, the rest of the node is usable by ZONE_MOVABLE
3713 kernelcore_remaining = kernelcore_node;
3715 /* Go through each range of PFNs within this node */
3716 for_each_active_range_index_in_nid(i, nid) {
3717 unsigned long start_pfn, end_pfn;
3718 unsigned long size_pages;
3720 start_pfn = max(early_node_map[i].start_pfn,
3721 zone_movable_pfn[nid]);
3722 end_pfn = early_node_map[i].end_pfn;
3723 if (start_pfn >= end_pfn)
3726 /* Account for what is only usable for kernelcore */
3727 if (start_pfn < usable_startpfn) {
3728 unsigned long kernel_pages;
3729 kernel_pages = min(end_pfn, usable_startpfn)
3732 kernelcore_remaining -= min(kernel_pages,
3733 kernelcore_remaining);
3734 required_kernelcore -= min(kernel_pages,
3735 required_kernelcore);
3737 /* Continue if range is now fully accounted */
3738 if (end_pfn <= usable_startpfn) {
3741 * Push zone_movable_pfn to the end so
3742 * that if we have to rebalance
3743 * kernelcore across nodes, we will
3744 * not double account here
3746 zone_movable_pfn[nid] = end_pfn;
3749 start_pfn = usable_startpfn;
3753 * The usable PFN range for ZONE_MOVABLE is from
3754 * start_pfn->end_pfn. Calculate size_pages as the
3755 * number of pages used as kernelcore
3757 size_pages = end_pfn - start_pfn;
3758 if (size_pages > kernelcore_remaining)
3759 size_pages = kernelcore_remaining;
3760 zone_movable_pfn[nid] = start_pfn + size_pages;
3763 * Some kernelcore has been met, update counts and
3764 * break if the kernelcore for this node has been
3767 required_kernelcore -= min(required_kernelcore,
3769 kernelcore_remaining -= size_pages;
3770 if (!kernelcore_remaining)
3776 * If there is still required_kernelcore, we do another pass with one
3777 * less node in the count. This will push zone_movable_pfn[nid] further
3778 * along on the nodes that still have memory until kernelcore is
3782 if (usable_nodes && required_kernelcore > usable_nodes)
3785 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3786 for (nid = 0; nid < MAX_NUMNODES; nid++)
3787 zone_movable_pfn[nid] =
3788 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
3791 /* Any regular memory on that node ? */
3792 static void check_for_regular_memory(pg_data_t *pgdat)
3794 #ifdef CONFIG_HIGHMEM
3795 enum zone_type zone_type;
3797 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
3798 struct zone *zone = &pgdat->node_zones[zone_type];
3799 if (zone->present_pages)
3800 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
3806 * free_area_init_nodes - Initialise all pg_data_t and zone data
3807 * @max_zone_pfn: an array of max PFNs for each zone
3809 * This will call free_area_init_node() for each active node in the system.
3810 * Using the page ranges provided by add_active_range(), the size of each
3811 * zone in each node and their holes is calculated. If the maximum PFN
3812 * between two adjacent zones match, it is assumed that the zone is empty.
3813 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3814 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3815 * starts where the previous one ended. For example, ZONE_DMA32 starts
3816 * at arch_max_dma_pfn.
3818 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
3823 /* Sort early_node_map as initialisation assumes it is sorted */
3826 /* Record where the zone boundaries are */
3827 memset(arch_zone_lowest_possible_pfn, 0,
3828 sizeof(arch_zone_lowest_possible_pfn));
3829 memset(arch_zone_highest_possible_pfn, 0,
3830 sizeof(arch_zone_highest_possible_pfn));
3831 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
3832 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
3833 for (i = 1; i < MAX_NR_ZONES; i++) {
3834 if (i == ZONE_MOVABLE)
3836 arch_zone_lowest_possible_pfn[i] =
3837 arch_zone_highest_possible_pfn[i-1];
3838 arch_zone_highest_possible_pfn[i] =
3839 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
3841 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
3842 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
3844 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
3845 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
3846 find_zone_movable_pfns_for_nodes(zone_movable_pfn);
3848 /* Print out the zone ranges */
3849 printk("Zone PFN ranges:\n");
3850 for (i = 0; i < MAX_NR_ZONES; i++) {
3851 if (i == ZONE_MOVABLE)
3853 printk(" %-8s %8lu -> %8lu\n",
3855 arch_zone_lowest_possible_pfn[i],
3856 arch_zone_highest_possible_pfn[i]);
3859 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
3860 printk("Movable zone start PFN for each node\n");
3861 for (i = 0; i < MAX_NUMNODES; i++) {
3862 if (zone_movable_pfn[i])
3863 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
3866 /* Print out the early_node_map[] */
3867 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
3868 for (i = 0; i < nr_nodemap_entries; i++)
3869 printk(" %3d: %8lu -> %8lu\n", early_node_map[i].nid,
3870 early_node_map[i].start_pfn,
3871 early_node_map[i].end_pfn);
3873 /* Initialise every node */
3874 setup_nr_node_ids();
3875 for_each_online_node(nid) {
3876 pg_data_t *pgdat = NODE_DATA(nid);
3877 free_area_init_node(nid, pgdat, NULL,
3878 find_min_pfn_for_node(nid), NULL);
3880 /* Any memory on that node */
3881 if (pgdat->node_present_pages)
3882 node_set_state(nid, N_HIGH_MEMORY);
3883 check_for_regular_memory(pgdat);
3887 static int __init cmdline_parse_core(char *p, unsigned long *core)
3889 unsigned long long coremem;
3893 coremem = memparse(p, &p);
3894 *core = coremem >> PAGE_SHIFT;
3896 /* Paranoid check that UL is enough for the coremem value */
3897 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
3903 * kernelcore=size sets the amount of memory for use for allocations that
3904 * cannot be reclaimed or migrated.
3906 static int __init cmdline_parse_kernelcore(char *p)
3908 return cmdline_parse_core(p, &required_kernelcore);
3912 * movablecore=size sets the amount of memory for use for allocations that
3913 * can be reclaimed or migrated.
3915 static int __init cmdline_parse_movablecore(char *p)
3917 return cmdline_parse_core(p, &required_movablecore);
3920 early_param("kernelcore", cmdline_parse_kernelcore);
3921 early_param("movablecore", cmdline_parse_movablecore);
3923 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3926 * set_dma_reserve - set the specified number of pages reserved in the first zone
3927 * @new_dma_reserve: The number of pages to mark reserved
3929 * The per-cpu batchsize and zone watermarks are determined by present_pages.
3930 * In the DMA zone, a significant percentage may be consumed by kernel image
3931 * and other unfreeable allocations which can skew the watermarks badly. This
3932 * function may optionally be used to account for unfreeable pages in the
3933 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
3934 * smaller per-cpu batchsize.
3936 void __init set_dma_reserve(unsigned long new_dma_reserve)
3938 dma_reserve = new_dma_reserve;
3941 #ifndef CONFIG_NEED_MULTIPLE_NODES
3942 static bootmem_data_t contig_bootmem_data;
3943 struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
3945 EXPORT_SYMBOL(contig_page_data);
3948 void __init free_area_init(unsigned long *zones_size)
3950 free_area_init_node(0, NODE_DATA(0), zones_size,
3951 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
3954 static int page_alloc_cpu_notify(struct notifier_block *self,
3955 unsigned long action, void *hcpu)
3957 int cpu = (unsigned long)hcpu;
3959 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
3960 local_irq_disable();
3962 vm_events_fold_cpu(cpu);
3964 refresh_cpu_vm_stats(cpu);
3969 void __init page_alloc_init(void)
3971 hotcpu_notifier(page_alloc_cpu_notify, 0);
3975 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
3976 * or min_free_kbytes changes.
3978 static void calculate_totalreserve_pages(void)
3980 struct pglist_data *pgdat;
3981 unsigned long reserve_pages = 0;
3982 enum zone_type i, j;
3984 for_each_online_pgdat(pgdat) {
3985 for (i = 0; i < MAX_NR_ZONES; i++) {
3986 struct zone *zone = pgdat->node_zones + i;
3987 unsigned long max = 0;
3989 /* Find valid and maximum lowmem_reserve in the zone */
3990 for (j = i; j < MAX_NR_ZONES; j++) {
3991 if (zone->lowmem_reserve[j] > max)
3992 max = zone->lowmem_reserve[j];
3995 /* we treat pages_high as reserved pages. */
3996 max += zone->pages_high;
3998 if (max > zone->present_pages)
3999 max = zone->present_pages;
4000 reserve_pages += max;
4003 totalreserve_pages = reserve_pages;
4007 * setup_per_zone_lowmem_reserve - called whenever
4008 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4009 * has a correct pages reserved value, so an adequate number of
4010 * pages are left in the zone after a successful __alloc_pages().
4012 static void setup_per_zone_lowmem_reserve(void)
4014 struct pglist_data *pgdat;
4015 enum zone_type j, idx;
4017 for_each_online_pgdat(pgdat) {
4018 for (j = 0; j < MAX_NR_ZONES; j++) {
4019 struct zone *zone = pgdat->node_zones + j;
4020 unsigned long present_pages = zone->present_pages;
4022 zone->lowmem_reserve[j] = 0;
4026 struct zone *lower_zone;
4030 if (sysctl_lowmem_reserve_ratio[idx] < 1)
4031 sysctl_lowmem_reserve_ratio[idx] = 1;
4033 lower_zone = pgdat->node_zones + idx;
4034 lower_zone->lowmem_reserve[j] = present_pages /
4035 sysctl_lowmem_reserve_ratio[idx];
4036 present_pages += lower_zone->present_pages;
4041 /* update totalreserve_pages */
4042 calculate_totalreserve_pages();
4046 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4048 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4049 * with respect to min_free_kbytes.
4051 void setup_per_zone_pages_min(void)
4053 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
4054 unsigned long lowmem_pages = 0;
4056 unsigned long flags;
4058 /* Calculate total number of !ZONE_HIGHMEM pages */
4059 for_each_zone(zone) {
4060 if (!is_highmem(zone))
4061 lowmem_pages += zone->present_pages;
4064 for_each_zone(zone) {
4067 spin_lock_irqsave(&zone->lru_lock, flags);
4068 tmp = (u64)pages_min * zone->present_pages;
4069 do_div(tmp, lowmem_pages);
4070 if (is_highmem(zone)) {
4072 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4073 * need highmem pages, so cap pages_min to a small
4076 * The (pages_high-pages_low) and (pages_low-pages_min)
4077 * deltas controls asynch page reclaim, and so should
4078 * not be capped for highmem.
4082 min_pages = zone->present_pages / 1024;
4083 if (min_pages < SWAP_CLUSTER_MAX)
4084 min_pages = SWAP_CLUSTER_MAX;
4085 if (min_pages > 128)
4087 zone->pages_min = min_pages;
4090 * If it's a lowmem zone, reserve a number of pages
4091 * proportionate to the zone's size.
4093 zone->pages_min = tmp;
4096 zone->pages_low = zone->pages_min + (tmp >> 2);
4097 zone->pages_high = zone->pages_min + (tmp >> 1);
4098 setup_zone_migrate_reserve(zone);
4099 spin_unlock_irqrestore(&zone->lru_lock, flags);
4102 /* update totalreserve_pages */
4103 calculate_totalreserve_pages();
4107 * Initialise min_free_kbytes.
4109 * For small machines we want it small (128k min). For large machines
4110 * we want it large (64MB max). But it is not linear, because network
4111 * bandwidth does not increase linearly with machine size. We use
4113 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4114 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4130 static int __init init_per_zone_pages_min(void)
4132 unsigned long lowmem_kbytes;
4134 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
4136 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
4137 if (min_free_kbytes < 128)
4138 min_free_kbytes = 128;
4139 if (min_free_kbytes > 65536)
4140 min_free_kbytes = 65536;
4141 setup_per_zone_pages_min();
4142 setup_per_zone_lowmem_reserve();
4145 module_init(init_per_zone_pages_min)
4148 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4149 * that we can call two helper functions whenever min_free_kbytes
4152 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
4153 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4155 proc_dointvec(table, write, file, buffer, length, ppos);
4157 setup_per_zone_pages_min();
4162 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4163 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4168 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4173 zone->min_unmapped_pages = (zone->present_pages *
4174 sysctl_min_unmapped_ratio) / 100;
4178 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4179 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4184 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4189 zone->min_slab_pages = (zone->present_pages *
4190 sysctl_min_slab_ratio) / 100;
4196 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4197 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4198 * whenever sysctl_lowmem_reserve_ratio changes.
4200 * The reserve ratio obviously has absolutely no relation with the
4201 * pages_min watermarks. The lowmem reserve ratio can only make sense
4202 * if in function of the boot time zone sizes.
4204 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4205 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4207 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4208 setup_per_zone_lowmem_reserve();
4213 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4214 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4215 * can have before it gets flushed back to buddy allocator.
4218 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
4219 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4225 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4226 if (!write || (ret == -EINVAL))
4228 for_each_zone(zone) {
4229 for_each_online_cpu(cpu) {
4231 high = zone->present_pages / percpu_pagelist_fraction;
4232 setup_pagelist_highmark(zone_pcp(zone, cpu), high);
4238 int hashdist = HASHDIST_DEFAULT;
4241 static int __init set_hashdist(char *str)
4245 hashdist = simple_strtoul(str, &str, 0);
4248 __setup("hashdist=", set_hashdist);
4252 * allocate a large system hash table from bootmem
4253 * - it is assumed that the hash table must contain an exact power-of-2
4254 * quantity of entries
4255 * - limit is the number of hash buckets, not the total allocation size
4257 void *__init alloc_large_system_hash(const char *tablename,
4258 unsigned long bucketsize,
4259 unsigned long numentries,
4262 unsigned int *_hash_shift,
4263 unsigned int *_hash_mask,
4264 unsigned long limit)
4266 unsigned long long max = limit;
4267 unsigned long log2qty, size;
4270 /* allow the kernel cmdline to have a say */
4272 /* round applicable memory size up to nearest megabyte */
4273 numentries = nr_kernel_pages;
4274 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
4275 numentries >>= 20 - PAGE_SHIFT;
4276 numentries <<= 20 - PAGE_SHIFT;
4278 /* limit to 1 bucket per 2^scale bytes of low memory */
4279 if (scale > PAGE_SHIFT)
4280 numentries >>= (scale - PAGE_SHIFT);
4282 numentries <<= (PAGE_SHIFT - scale);
4284 /* Make sure we've got at least a 0-order allocation.. */
4285 if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4286 numentries = PAGE_SIZE / bucketsize;
4288 numentries = roundup_pow_of_two(numentries);
4290 /* limit allocation size to 1/16 total memory by default */
4292 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
4293 do_div(max, bucketsize);
4296 if (numentries > max)
4299 log2qty = ilog2(numentries);
4302 size = bucketsize << log2qty;
4303 if (flags & HASH_EARLY)
4304 table = alloc_bootmem(size);
4306 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
4308 unsigned long order;
4309 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
4311 table = (void*) __get_free_pages(GFP_ATOMIC, order);
4313 * If bucketsize is not a power-of-two, we may free
4314 * some pages at the end of hash table.
4317 unsigned long alloc_end = (unsigned long)table +
4318 (PAGE_SIZE << order);
4319 unsigned long used = (unsigned long)table +
4321 split_page(virt_to_page(table), order);
4322 while (used < alloc_end) {
4328 } while (!table && size > PAGE_SIZE && --log2qty);
4331 panic("Failed to allocate %s hash table\n", tablename);
4333 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
4336 ilog2(size) - PAGE_SHIFT,
4340 *_hash_shift = log2qty;
4342 *_hash_mask = (1 << log2qty) - 1;
4347 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4348 struct page *pfn_to_page(unsigned long pfn)
4350 return __pfn_to_page(pfn);
4352 unsigned long page_to_pfn(struct page *page)
4354 return __page_to_pfn(page);
4356 EXPORT_SYMBOL(pfn_to_page);
4357 EXPORT_SYMBOL(page_to_pfn);
4358 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4360 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4361 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
4364 #ifdef CONFIG_SPARSEMEM
4365 return __pfn_to_section(pfn)->pageblock_flags;
4367 return zone->pageblock_flags;
4368 #endif /* CONFIG_SPARSEMEM */
4371 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
4373 #ifdef CONFIG_SPARSEMEM
4374 pfn &= (PAGES_PER_SECTION-1);
4375 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4377 pfn = pfn - zone->zone_start_pfn;
4378 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4379 #endif /* CONFIG_SPARSEMEM */
4383 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4384 * @page: The page within the block of interest
4385 * @start_bitidx: The first bit of interest to retrieve
4386 * @end_bitidx: The last bit of interest
4387 * returns pageblock_bits flags
4389 unsigned long get_pageblock_flags_group(struct page *page,
4390 int start_bitidx, int end_bitidx)
4393 unsigned long *bitmap;
4394 unsigned long pfn, bitidx;
4395 unsigned long flags = 0;
4396 unsigned long value = 1;
4398 zone = page_zone(page);
4399 pfn = page_to_pfn(page);
4400 bitmap = get_pageblock_bitmap(zone, pfn);
4401 bitidx = pfn_to_bitidx(zone, pfn);
4403 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4404 if (test_bit(bitidx + start_bitidx, bitmap))
4411 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4412 * @page: The page within the block of interest
4413 * @start_bitidx: The first bit of interest
4414 * @end_bitidx: The last bit of interest
4415 * @flags: The flags to set
4417 void set_pageblock_flags_group(struct page *page, unsigned long flags,
4418 int start_bitidx, int end_bitidx)
4421 unsigned long *bitmap;
4422 unsigned long pfn, bitidx;
4423 unsigned long value = 1;
4425 zone = page_zone(page);
4426 pfn = page_to_pfn(page);
4427 bitmap = get_pageblock_bitmap(zone, pfn);
4428 bitidx = pfn_to_bitidx(zone, pfn);
4430 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4432 __set_bit(bitidx + start_bitidx, bitmap);
4434 __clear_bit(bitidx + start_bitidx, bitmap);