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/config.h>
18 #include <linux/stddef.h>
20 #include <linux/swap.h>
21 #include <linux/interrupt.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/compiler.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/nodemask.h>
36 #include <linux/vmalloc.h>
38 #include <asm/tlbflush.h>
42 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
45 nodemask_t node_online_map = { { [0] = 1UL } };
46 EXPORT_SYMBOL(node_online_map);
47 nodemask_t node_possible_map = NODE_MASK_ALL;
48 EXPORT_SYMBOL(node_possible_map);
49 struct pglist_data *pgdat_list;
50 unsigned long totalram_pages;
51 unsigned long totalhigh_pages;
55 * results with 256, 32 in the lowmem_reserve sysctl:
56 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
57 * 1G machine -> (16M dma, 784M normal, 224M high)
58 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
59 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
60 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
62 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 32 };
64 EXPORT_SYMBOL(totalram_pages);
65 EXPORT_SYMBOL(nr_swap_pages);
68 * Used by page_zone() to look up the address of the struct zone whose
69 * id is encoded in the upper bits of page->flags
71 struct zone *zone_table[1 << (ZONES_SHIFT + NODES_SHIFT)];
72 EXPORT_SYMBOL(zone_table);
75 static struct per_cpu_pageset
76 pageset_table[MAX_NR_ZONES*MAX_NUMNODES*NR_CPUS] __initdata;
79 static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" };
80 int min_free_kbytes = 1024;
82 unsigned long __initdata nr_kernel_pages;
83 unsigned long __initdata nr_all_pages;
86 * Temporary debugging check for pages not lying within a given zone.
88 static int bad_range(struct zone *zone, struct page *page)
90 if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages)
92 if (page_to_pfn(page) < zone->zone_start_pfn)
94 #ifdef CONFIG_HOLES_IN_ZONE
95 if (!pfn_valid(page_to_pfn(page)))
98 if (zone != page_zone(page))
103 static void bad_page(const char *function, struct page *page)
105 printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
106 function, current->comm, page);
107 printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
108 (int)(2*sizeof(page_flags_t)), (unsigned long)page->flags,
109 page->mapping, page_mapcount(page), page_count(page));
110 printk(KERN_EMERG "Backtrace:\n");
112 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");
113 page->flags &= ~(1 << PG_private |
120 set_page_count(page, 0);
121 reset_page_mapcount(page);
122 page->mapping = NULL;
123 tainted |= TAINT_BAD_PAGE;
126 #ifndef CONFIG_HUGETLB_PAGE
127 #define prep_compound_page(page, order) do { } while (0)
128 #define destroy_compound_page(page, order) do { } while (0)
131 * Higher-order pages are called "compound pages". They are structured thusly:
133 * The first PAGE_SIZE page is called the "head page".
135 * The remaining PAGE_SIZE pages are called "tail pages".
137 * All pages have PG_compound set. All pages have their ->private pointing at
138 * the head page (even the head page has this).
140 * The first tail page's ->mapping, if non-zero, holds the address of the
141 * compound page's put_page() function.
143 * The order of the allocation is stored in the first tail page's ->index
144 * This is only for debug at present. This usage means that zero-order pages
145 * may not be compound.
147 static void prep_compound_page(struct page *page, unsigned long order)
150 int nr_pages = 1 << order;
152 page[1].mapping = NULL;
153 page[1].index = order;
154 for (i = 0; i < nr_pages; i++) {
155 struct page *p = page + i;
158 p->private = (unsigned long)page;
162 static void destroy_compound_page(struct page *page, unsigned long order)
165 int nr_pages = 1 << order;
167 if (!PageCompound(page))
170 if (page[1].index != order)
171 bad_page(__FUNCTION__, page);
173 for (i = 0; i < nr_pages; i++) {
174 struct page *p = page + i;
176 if (!PageCompound(p))
177 bad_page(__FUNCTION__, page);
178 if (p->private != (unsigned long)page)
179 bad_page(__FUNCTION__, page);
180 ClearPageCompound(p);
183 #endif /* CONFIG_HUGETLB_PAGE */
186 * function for dealing with page's order in buddy system.
187 * zone->lock is already acquired when we use these.
188 * So, we don't need atomic page->flags operations here.
190 static inline unsigned long page_order(struct page *page) {
191 return page->private;
194 static inline void set_page_order(struct page *page, int order) {
195 page->private = order;
196 __SetPagePrivate(page);
199 static inline void rmv_page_order(struct page *page)
201 __ClearPagePrivate(page);
206 * Locate the struct page for both the matching buddy in our
207 * pair (buddy1) and the combined O(n+1) page they form (page).
209 * 1) Any buddy B1 will have an order O twin B2 which satisfies
210 * the following equation:
212 * For example, if the starting buddy (buddy2) is #8 its order
214 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
216 * 2) Any buddy B will have an order O+1 parent P which
217 * satisfies the following equation:
220 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
222 static inline struct page *
223 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
225 unsigned long buddy_idx = page_idx ^ (1 << order);
227 return page + (buddy_idx - page_idx);
230 static inline unsigned long
231 __find_combined_index(unsigned long page_idx, unsigned int order)
233 return (page_idx & ~(1 << order));
237 * This function checks whether a page is free && is the buddy
238 * we can do coalesce a page and its buddy if
239 * (a) the buddy is free &&
240 * (b) the buddy is on the buddy system &&
241 * (c) a page and its buddy have the same order.
242 * for recording page's order, we use page->private and PG_private.
245 static inline int page_is_buddy(struct page *page, int order)
247 if (PagePrivate(page) &&
248 (page_order(page) == order) &&
249 !PageReserved(page) &&
250 page_count(page) == 0)
256 * Freeing function for a buddy system allocator.
258 * The concept of a buddy system is to maintain direct-mapped table
259 * (containing bit values) for memory blocks of various "orders".
260 * The bottom level table contains the map for the smallest allocatable
261 * units of memory (here, pages), and each level above it describes
262 * pairs of units from the levels below, hence, "buddies".
263 * At a high level, all that happens here is marking the table entry
264 * at the bottom level available, and propagating the changes upward
265 * as necessary, plus some accounting needed to play nicely with other
266 * parts of the VM system.
267 * At each level, we keep a list of pages, which are heads of continuous
268 * free pages of length of (1 << order) and marked with PG_Private.Page's
269 * order is recorded in page->private field.
270 * So when we are allocating or freeing one, we can derive the state of the
271 * other. That is, if we allocate a small block, and both were
272 * free, the remainder of the region must be split into blocks.
273 * If a block is freed, and its buddy is also free, then this
274 * triggers coalescing into a block of larger size.
279 static inline void __free_pages_bulk (struct page *page,
280 struct zone *zone, unsigned int order)
282 unsigned long page_idx;
283 int order_size = 1 << order;
286 destroy_compound_page(page, order);
288 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
290 BUG_ON(page_idx & (order_size - 1));
291 BUG_ON(bad_range(zone, page));
293 zone->free_pages += order_size;
294 while (order < MAX_ORDER-1) {
295 unsigned long combined_idx;
296 struct free_area *area;
299 combined_idx = __find_combined_index(page_idx, order);
300 buddy = __page_find_buddy(page, page_idx, order);
302 if (bad_range(zone, buddy))
304 if (!page_is_buddy(buddy, order))
305 break; /* Move the buddy up one level. */
306 list_del(&buddy->lru);
307 area = zone->free_area + order;
309 rmv_page_order(buddy);
310 page = page + (combined_idx - page_idx);
311 page_idx = combined_idx;
314 set_page_order(page, order);
315 list_add(&page->lru, &zone->free_area[order].free_list);
316 zone->free_area[order].nr_free++;
319 static inline void free_pages_check(const char *function, struct page *page)
321 if ( page_mapcount(page) ||
322 page->mapping != NULL ||
323 page_count(page) != 0 ||
332 1 << PG_writeback )))
333 bad_page(function, page);
335 ClearPageDirty(page);
339 * Frees a list of pages.
340 * Assumes all pages on list are in same zone, and of same order.
341 * count is the number of pages to free, or 0 for all on the list.
343 * If the zone was previously in an "all pages pinned" state then look to
344 * see if this freeing clears that state.
346 * And clear the zone's pages_scanned counter, to hold off the "all pages are
347 * pinned" detection logic.
350 free_pages_bulk(struct zone *zone, int count,
351 struct list_head *list, unsigned int order)
354 struct page *page = NULL;
357 spin_lock_irqsave(&zone->lock, flags);
358 zone->all_unreclaimable = 0;
359 zone->pages_scanned = 0;
360 while (!list_empty(list) && count--) {
361 page = list_entry(list->prev, struct page, lru);
362 /* have to delete it as __free_pages_bulk list manipulates */
363 list_del(&page->lru);
364 __free_pages_bulk(page, zone, order);
367 spin_unlock_irqrestore(&zone->lock, flags);
371 void __free_pages_ok(struct page *page, unsigned int order)
376 arch_free_page(page, order);
378 mod_page_state(pgfree, 1 << order);
382 for (i = 1 ; i < (1 << order) ; ++i)
383 __put_page(page + i);
386 for (i = 0 ; i < (1 << order) ; ++i)
387 free_pages_check(__FUNCTION__, page + i);
388 list_add(&page->lru, &list);
389 kernel_map_pages(page, 1<<order, 0);
390 free_pages_bulk(page_zone(page), 1, &list, order);
395 * The order of subdivision here is critical for the IO subsystem.
396 * Please do not alter this order without good reasons and regression
397 * testing. Specifically, as large blocks of memory are subdivided,
398 * the order in which smaller blocks are delivered depends on the order
399 * they're subdivided in this function. This is the primary factor
400 * influencing the order in which pages are delivered to the IO
401 * subsystem according to empirical testing, and this is also justified
402 * by considering the behavior of a buddy system containing a single
403 * large block of memory acted on by a series of small allocations.
404 * This behavior is a critical factor in sglist merging's success.
408 static inline struct page *
409 expand(struct zone *zone, struct page *page,
410 int low, int high, struct free_area *area)
412 unsigned long size = 1 << high;
418 BUG_ON(bad_range(zone, &page[size]));
419 list_add(&page[size].lru, &area->free_list);
421 set_page_order(&page[size], high);
426 void set_page_refs(struct page *page, int order)
429 set_page_count(page, 1);
434 * We need to reference all the pages for this order, otherwise if
435 * anyone accesses one of the pages with (get/put) it will be freed.
436 * - eg: access_process_vm()
438 for (i = 0; i < (1 << order); i++)
439 set_page_count(page + i, 1);
440 #endif /* CONFIG_MMU */
444 * This page is about to be returned from the page allocator
446 static void prep_new_page(struct page *page, int order)
448 if (page->mapping || page_mapcount(page) ||
457 1 << PG_writeback )))
458 bad_page(__FUNCTION__, page);
460 page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
461 1 << PG_referenced | 1 << PG_arch_1 |
462 1 << PG_checked | 1 << PG_mappedtodisk);
464 set_page_refs(page, order);
465 kernel_map_pages(page, 1 << order, 1);
469 * Do the hard work of removing an element from the buddy allocator.
470 * Call me with the zone->lock already held.
472 static struct page *__rmqueue(struct zone *zone, unsigned int order)
474 struct free_area * area;
475 unsigned int current_order;
478 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
479 area = zone->free_area + current_order;
480 if (list_empty(&area->free_list))
483 page = list_entry(area->free_list.next, struct page, lru);
484 list_del(&page->lru);
485 rmv_page_order(page);
487 zone->free_pages -= 1UL << order;
488 return expand(zone, page, order, current_order, area);
495 * Obtain a specified number of elements from the buddy allocator, all under
496 * a single hold of the lock, for efficiency. Add them to the supplied list.
497 * Returns the number of new pages which were placed at *list.
499 static int rmqueue_bulk(struct zone *zone, unsigned int order,
500 unsigned long count, struct list_head *list)
507 spin_lock_irqsave(&zone->lock, flags);
508 for (i = 0; i < count; ++i) {
509 page = __rmqueue(zone, order);
513 list_add_tail(&page->lru, list);
515 spin_unlock_irqrestore(&zone->lock, flags);
519 #if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
520 static void __drain_pages(unsigned int cpu)
525 for_each_zone(zone) {
526 struct per_cpu_pageset *pset;
528 pset = zone_pcp(zone, cpu);
529 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
530 struct per_cpu_pages *pcp;
533 pcp->count -= free_pages_bulk(zone, pcp->count,
538 #endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
542 void mark_free_pages(struct zone *zone)
544 unsigned long zone_pfn, flags;
546 struct list_head *curr;
548 if (!zone->spanned_pages)
551 spin_lock_irqsave(&zone->lock, flags);
552 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
553 ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn));
555 for (order = MAX_ORDER - 1; order >= 0; --order)
556 list_for_each(curr, &zone->free_area[order].free_list) {
557 unsigned long start_pfn, i;
559 start_pfn = page_to_pfn(list_entry(curr, struct page, lru));
561 for (i=0; i < (1<<order); i++)
562 SetPageNosaveFree(pfn_to_page(start_pfn+i));
564 spin_unlock_irqrestore(&zone->lock, flags);
568 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
570 void drain_local_pages(void)
574 local_irq_save(flags);
575 __drain_pages(smp_processor_id());
576 local_irq_restore(flags);
578 #endif /* CONFIG_PM */
580 static void zone_statistics(struct zonelist *zonelist, struct zone *z)
585 pg_data_t *pg = z->zone_pgdat;
586 pg_data_t *orig = zonelist->zones[0]->zone_pgdat;
587 struct per_cpu_pageset *p;
589 local_irq_save(flags);
590 cpu = smp_processor_id();
596 zone_pcp(zonelist->zones[0], cpu)->numa_foreign++;
598 if (pg == NODE_DATA(numa_node_id()))
602 local_irq_restore(flags);
607 * Free a 0-order page
609 static void FASTCALL(free_hot_cold_page(struct page *page, int cold));
610 static void fastcall free_hot_cold_page(struct page *page, int cold)
612 struct zone *zone = page_zone(page);
613 struct per_cpu_pages *pcp;
616 arch_free_page(page, 0);
618 kernel_map_pages(page, 1, 0);
619 inc_page_state(pgfree);
621 page->mapping = NULL;
622 free_pages_check(__FUNCTION__, page);
623 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
624 local_irq_save(flags);
625 if (pcp->count >= pcp->high)
626 pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
627 list_add(&page->lru, &pcp->list);
629 local_irq_restore(flags);
633 void fastcall free_hot_page(struct page *page)
635 free_hot_cold_page(page, 0);
638 void fastcall free_cold_page(struct page *page)
640 free_hot_cold_page(page, 1);
643 static inline void prep_zero_page(struct page *page, int order, unsigned int __nocast gfp_flags)
647 BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
648 for(i = 0; i < (1 << order); i++)
649 clear_highpage(page + i);
653 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
654 * we cheat by calling it from here, in the order > 0 path. Saves a branch
658 buffered_rmqueue(struct zone *zone, int order, unsigned int __nocast gfp_flags)
661 struct page *page = NULL;
662 int cold = !!(gfp_flags & __GFP_COLD);
665 struct per_cpu_pages *pcp;
667 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
668 local_irq_save(flags);
669 if (pcp->count <= pcp->low)
670 pcp->count += rmqueue_bulk(zone, 0,
671 pcp->batch, &pcp->list);
673 page = list_entry(pcp->list.next, struct page, lru);
674 list_del(&page->lru);
677 local_irq_restore(flags);
682 spin_lock_irqsave(&zone->lock, flags);
683 page = __rmqueue(zone, order);
684 spin_unlock_irqrestore(&zone->lock, flags);
688 BUG_ON(bad_range(zone, page));
689 mod_page_state_zone(zone, pgalloc, 1 << order);
690 prep_new_page(page, order);
692 if (gfp_flags & __GFP_ZERO)
693 prep_zero_page(page, order, gfp_flags);
695 if (order && (gfp_flags & __GFP_COMP))
696 prep_compound_page(page, order);
702 * Return 1 if free pages are above 'mark'. This takes into account the order
705 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
706 int classzone_idx, int can_try_harder, int gfp_high)
708 /* free_pages my go negative - that's OK */
709 long min = mark, free_pages = z->free_pages - (1 << order) + 1;
717 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
719 for (o = 0; o < order; o++) {
720 /* At the next order, this order's pages become unavailable */
721 free_pages -= z->free_area[o].nr_free << o;
723 /* Require fewer higher order pages to be free */
726 if (free_pages <= min)
733 should_reclaim_zone(struct zone *z, unsigned int gfp_mask)
735 if (!z->reclaim_pages)
737 if (gfp_mask & __GFP_NORECLAIM)
743 * This is the 'heart' of the zoned buddy allocator.
745 struct page * fastcall
746 __alloc_pages(unsigned int __nocast gfp_mask, unsigned int order,
747 struct zonelist *zonelist)
749 const int wait = gfp_mask & __GFP_WAIT;
750 struct zone **zones, *z;
752 struct reclaim_state reclaim_state;
753 struct task_struct *p = current;
758 int did_some_progress;
760 might_sleep_if(wait);
763 * The caller may dip into page reserves a bit more if the caller
764 * cannot run direct reclaim, or is the caller has realtime scheduling
767 can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait;
769 zones = zonelist->zones; /* the list of zones suitable for gfp_mask */
771 if (unlikely(zones[0] == NULL)) {
772 /* Should this ever happen?? */
776 classzone_idx = zone_idx(zones[0]);
779 /* Go through the zonelist once, looking for a zone with enough free */
780 for (i = 0; (z = zones[i]) != NULL; i++) {
781 int do_reclaim = should_reclaim_zone(z, gfp_mask);
783 if (!cpuset_zone_allowed(z))
787 * If the zone is to attempt early page reclaim then this loop
788 * will try to reclaim pages and check the watermark a second
789 * time before giving up and falling back to the next zone.
792 if (!zone_watermark_ok(z, order, z->pages_low,
793 classzone_idx, 0, 0)) {
797 zone_reclaim(z, gfp_mask, order);
798 /* Only try reclaim once */
800 goto zone_reclaim_retry;
804 page = buffered_rmqueue(z, order, gfp_mask);
809 for (i = 0; (z = zones[i]) != NULL; i++)
810 wakeup_kswapd(z, order);
813 * Go through the zonelist again. Let __GFP_HIGH and allocations
814 * coming from realtime tasks to go deeper into reserves
816 * This is the last chance, in general, before the goto nopage.
817 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
819 for (i = 0; (z = zones[i]) != NULL; i++) {
820 if (!zone_watermark_ok(z, order, z->pages_min,
821 classzone_idx, can_try_harder,
822 gfp_mask & __GFP_HIGH))
825 if (wait && !cpuset_zone_allowed(z))
828 page = buffered_rmqueue(z, order, gfp_mask);
833 /* This allocation should allow future memory freeing. */
835 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
836 && !in_interrupt()) {
837 if (!(gfp_mask & __GFP_NOMEMALLOC)) {
838 /* go through the zonelist yet again, ignoring mins */
839 for (i = 0; (z = zones[i]) != NULL; i++) {
840 if (!cpuset_zone_allowed(z))
842 page = buffered_rmqueue(z, order, gfp_mask);
850 /* Atomic allocations - we can't balance anything */
857 /* We now go into synchronous reclaim */
858 p->flags |= PF_MEMALLOC;
859 reclaim_state.reclaimed_slab = 0;
860 p->reclaim_state = &reclaim_state;
862 did_some_progress = try_to_free_pages(zones, gfp_mask);
864 p->reclaim_state = NULL;
865 p->flags &= ~PF_MEMALLOC;
869 if (likely(did_some_progress)) {
871 * Go through the zonelist yet one more time, keep
872 * very high watermark here, this is only to catch
873 * a parallel oom killing, we must fail if we're still
874 * under heavy pressure.
876 for (i = 0; (z = zones[i]) != NULL; i++) {
877 if (!zone_watermark_ok(z, order, z->pages_min,
878 classzone_idx, can_try_harder,
879 gfp_mask & __GFP_HIGH))
882 if (!cpuset_zone_allowed(z))
885 page = buffered_rmqueue(z, order, gfp_mask);
889 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
891 * Go through the zonelist yet one more time, keep
892 * very high watermark here, this is only to catch
893 * a parallel oom killing, we must fail if we're still
894 * under heavy pressure.
896 for (i = 0; (z = zones[i]) != NULL; i++) {
897 if (!zone_watermark_ok(z, order, z->pages_high,
898 classzone_idx, 0, 0))
901 if (!cpuset_zone_allowed(z))
904 page = buffered_rmqueue(z, order, gfp_mask);
909 out_of_memory(gfp_mask);
914 * Don't let big-order allocations loop unless the caller explicitly
915 * requests that. Wait for some write requests to complete then retry.
917 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
918 * <= 3, but that may not be true in other implementations.
921 if (!(gfp_mask & __GFP_NORETRY)) {
922 if ((order <= 3) || (gfp_mask & __GFP_REPEAT))
924 if (gfp_mask & __GFP_NOFAIL)
928 blk_congestion_wait(WRITE, HZ/50);
933 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
934 printk(KERN_WARNING "%s: page allocation failure."
935 " order:%d, mode:0x%x\n",
936 p->comm, order, gfp_mask);
941 zone_statistics(zonelist, z);
945 EXPORT_SYMBOL(__alloc_pages);
948 * Common helper functions.
950 fastcall unsigned long __get_free_pages(unsigned int __nocast gfp_mask, unsigned int order)
953 page = alloc_pages(gfp_mask, order);
956 return (unsigned long) page_address(page);
959 EXPORT_SYMBOL(__get_free_pages);
961 fastcall unsigned long get_zeroed_page(unsigned int __nocast gfp_mask)
966 * get_zeroed_page() returns a 32-bit address, which cannot represent
969 BUG_ON(gfp_mask & __GFP_HIGHMEM);
971 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
973 return (unsigned long) page_address(page);
977 EXPORT_SYMBOL(get_zeroed_page);
979 void __pagevec_free(struct pagevec *pvec)
981 int i = pagevec_count(pvec);
984 free_hot_cold_page(pvec->pages[i], pvec->cold);
987 fastcall void __free_pages(struct page *page, unsigned int order)
989 if (!PageReserved(page) && put_page_testzero(page)) {
993 __free_pages_ok(page, order);
997 EXPORT_SYMBOL(__free_pages);
999 fastcall void free_pages(unsigned long addr, unsigned int order)
1002 BUG_ON(!virt_addr_valid((void *)addr));
1003 __free_pages(virt_to_page((void *)addr), order);
1007 EXPORT_SYMBOL(free_pages);
1010 * Total amount of free (allocatable) RAM:
1012 unsigned int nr_free_pages(void)
1014 unsigned int sum = 0;
1018 sum += zone->free_pages;
1023 EXPORT_SYMBOL(nr_free_pages);
1026 unsigned int nr_free_pages_pgdat(pg_data_t *pgdat)
1028 unsigned int i, sum = 0;
1030 for (i = 0; i < MAX_NR_ZONES; i++)
1031 sum += pgdat->node_zones[i].free_pages;
1037 static unsigned int nr_free_zone_pages(int offset)
1040 unsigned int sum = 0;
1042 for_each_pgdat(pgdat) {
1043 struct zonelist *zonelist = pgdat->node_zonelists + offset;
1044 struct zone **zonep = zonelist->zones;
1047 for (zone = *zonep++; zone; zone = *zonep++) {
1048 unsigned long size = zone->present_pages;
1049 unsigned long high = zone->pages_high;
1059 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1061 unsigned int nr_free_buffer_pages(void)
1063 return nr_free_zone_pages(GFP_USER & GFP_ZONEMASK);
1067 * Amount of free RAM allocatable within all zones
1069 unsigned int nr_free_pagecache_pages(void)
1071 return nr_free_zone_pages(GFP_HIGHUSER & GFP_ZONEMASK);
1074 #ifdef CONFIG_HIGHMEM
1075 unsigned int nr_free_highpages (void)
1078 unsigned int pages = 0;
1080 for_each_pgdat(pgdat)
1081 pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1088 static void show_node(struct zone *zone)
1090 printk("Node %d ", zone->zone_pgdat->node_id);
1093 #define show_node(zone) do { } while (0)
1097 * Accumulate the page_state information across all CPUs.
1098 * The result is unavoidably approximate - it can change
1099 * during and after execution of this function.
1101 static DEFINE_PER_CPU(struct page_state, page_states) = {0};
1103 atomic_t nr_pagecache = ATOMIC_INIT(0);
1104 EXPORT_SYMBOL(nr_pagecache);
1106 DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
1109 void __get_page_state(struct page_state *ret, int nr)
1113 memset(ret, 0, sizeof(*ret));
1115 cpu = first_cpu(cpu_online_map);
1116 while (cpu < NR_CPUS) {
1117 unsigned long *in, *out, off;
1119 in = (unsigned long *)&per_cpu(page_states, cpu);
1121 cpu = next_cpu(cpu, cpu_online_map);
1124 prefetch(&per_cpu(page_states, cpu));
1126 out = (unsigned long *)ret;
1127 for (off = 0; off < nr; off++)
1132 void get_page_state(struct page_state *ret)
1136 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
1137 nr /= sizeof(unsigned long);
1139 __get_page_state(ret, nr + 1);
1142 void get_full_page_state(struct page_state *ret)
1144 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long));
1147 unsigned long __read_page_state(unsigned long offset)
1149 unsigned long ret = 0;
1152 for_each_online_cpu(cpu) {
1155 in = (unsigned long)&per_cpu(page_states, cpu) + offset;
1156 ret += *((unsigned long *)in);
1161 void __mod_page_state(unsigned long offset, unsigned long delta)
1163 unsigned long flags;
1166 local_irq_save(flags);
1167 ptr = &__get_cpu_var(page_states);
1168 *(unsigned long*)(ptr + offset) += delta;
1169 local_irq_restore(flags);
1172 EXPORT_SYMBOL(__mod_page_state);
1174 void __get_zone_counts(unsigned long *active, unsigned long *inactive,
1175 unsigned long *free, struct pglist_data *pgdat)
1177 struct zone *zones = pgdat->node_zones;
1183 for (i = 0; i < MAX_NR_ZONES; i++) {
1184 *active += zones[i].nr_active;
1185 *inactive += zones[i].nr_inactive;
1186 *free += zones[i].free_pages;
1190 void get_zone_counts(unsigned long *active,
1191 unsigned long *inactive, unsigned long *free)
1193 struct pglist_data *pgdat;
1198 for_each_pgdat(pgdat) {
1199 unsigned long l, m, n;
1200 __get_zone_counts(&l, &m, &n, pgdat);
1207 void si_meminfo(struct sysinfo *val)
1209 val->totalram = totalram_pages;
1211 val->freeram = nr_free_pages();
1212 val->bufferram = nr_blockdev_pages();
1213 #ifdef CONFIG_HIGHMEM
1214 val->totalhigh = totalhigh_pages;
1215 val->freehigh = nr_free_highpages();
1220 val->mem_unit = PAGE_SIZE;
1223 EXPORT_SYMBOL(si_meminfo);
1226 void si_meminfo_node(struct sysinfo *val, int nid)
1228 pg_data_t *pgdat = NODE_DATA(nid);
1230 val->totalram = pgdat->node_present_pages;
1231 val->freeram = nr_free_pages_pgdat(pgdat);
1232 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1233 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1234 val->mem_unit = PAGE_SIZE;
1238 #define K(x) ((x) << (PAGE_SHIFT-10))
1241 * Show free area list (used inside shift_scroll-lock stuff)
1242 * We also calculate the percentage fragmentation. We do this by counting the
1243 * memory on each free list with the exception of the first item on the list.
1245 void show_free_areas(void)
1247 struct page_state ps;
1248 int cpu, temperature;
1249 unsigned long active;
1250 unsigned long inactive;
1254 for_each_zone(zone) {
1256 printk("%s per-cpu:", zone->name);
1258 if (!zone->present_pages) {
1264 for (cpu = 0; cpu < NR_CPUS; ++cpu) {
1265 struct per_cpu_pageset *pageset;
1267 if (!cpu_possible(cpu))
1270 pageset = zone_pcp(zone, cpu);
1272 for (temperature = 0; temperature < 2; temperature++)
1273 printk("cpu %d %s: low %d, high %d, batch %d\n",
1275 temperature ? "cold" : "hot",
1276 pageset->pcp[temperature].low,
1277 pageset->pcp[temperature].high,
1278 pageset->pcp[temperature].batch);
1282 get_page_state(&ps);
1283 get_zone_counts(&active, &inactive, &free);
1285 printk("\nFree pages: %11ukB (%ukB HighMem)\n",
1287 K(nr_free_highpages()));
1289 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1290 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1299 ps.nr_page_table_pages);
1301 for_each_zone(zone) {
1313 " pages_scanned:%lu"
1314 " all_unreclaimable? %s"
1317 K(zone->free_pages),
1320 K(zone->pages_high),
1322 K(zone->nr_inactive),
1323 K(zone->present_pages),
1324 zone->pages_scanned,
1325 (zone->all_unreclaimable ? "yes" : "no")
1327 printk("lowmem_reserve[]:");
1328 for (i = 0; i < MAX_NR_ZONES; i++)
1329 printk(" %lu", zone->lowmem_reserve[i]);
1333 for_each_zone(zone) {
1334 unsigned long nr, flags, order, total = 0;
1337 printk("%s: ", zone->name);
1338 if (!zone->present_pages) {
1343 spin_lock_irqsave(&zone->lock, flags);
1344 for (order = 0; order < MAX_ORDER; order++) {
1345 nr = zone->free_area[order].nr_free;
1346 total += nr << order;
1347 printk("%lu*%lukB ", nr, K(1UL) << order);
1349 spin_unlock_irqrestore(&zone->lock, flags);
1350 printk("= %lukB\n", K(total));
1353 show_swap_cache_info();
1357 * Builds allocation fallback zone lists.
1359 static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, int j, int k)
1366 zone = pgdat->node_zones + ZONE_HIGHMEM;
1367 if (zone->present_pages) {
1368 #ifndef CONFIG_HIGHMEM
1371 zonelist->zones[j++] = zone;
1374 zone = pgdat->node_zones + ZONE_NORMAL;
1375 if (zone->present_pages)
1376 zonelist->zones[j++] = zone;
1378 zone = pgdat->node_zones + ZONE_DMA;
1379 if (zone->present_pages)
1380 zonelist->zones[j++] = zone;
1387 #define MAX_NODE_LOAD (num_online_nodes())
1388 static int __initdata node_load[MAX_NUMNODES];
1390 * find_next_best_node - find the next node that should appear in a given node's fallback list
1391 * @node: node whose fallback list we're appending
1392 * @used_node_mask: nodemask_t of already used nodes
1394 * We use a number of factors to determine which is the next node that should
1395 * appear on a given node's fallback list. The node should not have appeared
1396 * already in @node's fallback list, and it should be the next closest node
1397 * according to the distance array (which contains arbitrary distance values
1398 * from each node to each node in the system), and should also prefer nodes
1399 * with no CPUs, since presumably they'll have very little allocation pressure
1400 * on them otherwise.
1401 * It returns -1 if no node is found.
1403 static int __init find_next_best_node(int node, nodemask_t *used_node_mask)
1406 int min_val = INT_MAX;
1409 for_each_online_node(i) {
1412 /* Start from local node */
1413 n = (node+i) % num_online_nodes();
1415 /* Don't want a node to appear more than once */
1416 if (node_isset(n, *used_node_mask))
1419 /* Use the local node if we haven't already */
1420 if (!node_isset(node, *used_node_mask)) {
1425 /* Use the distance array to find the distance */
1426 val = node_distance(node, n);
1428 /* Give preference to headless and unused nodes */
1429 tmp = node_to_cpumask(n);
1430 if (!cpus_empty(tmp))
1431 val += PENALTY_FOR_NODE_WITH_CPUS;
1433 /* Slight preference for less loaded node */
1434 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
1435 val += node_load[n];
1437 if (val < min_val) {
1444 node_set(best_node, *used_node_mask);
1449 static void __init build_zonelists(pg_data_t *pgdat)
1451 int i, j, k, node, local_node;
1452 int prev_node, load;
1453 struct zonelist *zonelist;
1454 nodemask_t used_mask;
1456 /* initialize zonelists */
1457 for (i = 0; i < GFP_ZONETYPES; i++) {
1458 zonelist = pgdat->node_zonelists + i;
1459 zonelist->zones[0] = NULL;
1462 /* NUMA-aware ordering of nodes */
1463 local_node = pgdat->node_id;
1464 load = num_online_nodes();
1465 prev_node = local_node;
1466 nodes_clear(used_mask);
1467 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
1469 * We don't want to pressure a particular node.
1470 * So adding penalty to the first node in same
1471 * distance group to make it round-robin.
1473 if (node_distance(local_node, node) !=
1474 node_distance(local_node, prev_node))
1475 node_load[node] += load;
1478 for (i = 0; i < GFP_ZONETYPES; i++) {
1479 zonelist = pgdat->node_zonelists + i;
1480 for (j = 0; zonelist->zones[j] != NULL; j++);
1483 if (i & __GFP_HIGHMEM)
1488 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1489 zonelist->zones[j] = NULL;
1494 #else /* CONFIG_NUMA */
1496 static void __init build_zonelists(pg_data_t *pgdat)
1498 int i, j, k, node, local_node;
1500 local_node = pgdat->node_id;
1501 for (i = 0; i < GFP_ZONETYPES; i++) {
1502 struct zonelist *zonelist;
1504 zonelist = pgdat->node_zonelists + i;
1508 if (i & __GFP_HIGHMEM)
1513 j = build_zonelists_node(pgdat, zonelist, j, k);
1515 * Now we build the zonelist so that it contains the zones
1516 * of all the other nodes.
1517 * We don't want to pressure a particular node, so when
1518 * building the zones for node N, we make sure that the
1519 * zones coming right after the local ones are those from
1520 * node N+1 (modulo N)
1522 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
1523 if (!node_online(node))
1525 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1527 for (node = 0; node < local_node; node++) {
1528 if (!node_online(node))
1530 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1533 zonelist->zones[j] = NULL;
1537 #endif /* CONFIG_NUMA */
1539 void __init build_all_zonelists(void)
1543 for_each_online_node(i)
1544 build_zonelists(NODE_DATA(i));
1545 printk("Built %i zonelists\n", num_online_nodes());
1546 cpuset_init_current_mems_allowed();
1550 * Helper functions to size the waitqueue hash table.
1551 * Essentially these want to choose hash table sizes sufficiently
1552 * large so that collisions trying to wait on pages are rare.
1553 * But in fact, the number of active page waitqueues on typical
1554 * systems is ridiculously low, less than 200. So this is even
1555 * conservative, even though it seems large.
1557 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1558 * waitqueues, i.e. the size of the waitq table given the number of pages.
1560 #define PAGES_PER_WAITQUEUE 256
1562 static inline unsigned long wait_table_size(unsigned long pages)
1564 unsigned long size = 1;
1566 pages /= PAGES_PER_WAITQUEUE;
1568 while (size < pages)
1572 * Once we have dozens or even hundreds of threads sleeping
1573 * on IO we've got bigger problems than wait queue collision.
1574 * Limit the size of the wait table to a reasonable size.
1576 size = min(size, 4096UL);
1578 return max(size, 4UL);
1582 * This is an integer logarithm so that shifts can be used later
1583 * to extract the more random high bits from the multiplicative
1584 * hash function before the remainder is taken.
1586 static inline unsigned long wait_table_bits(unsigned long size)
1591 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1593 static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
1594 unsigned long *zones_size, unsigned long *zholes_size)
1596 unsigned long realtotalpages, totalpages = 0;
1599 for (i = 0; i < MAX_NR_ZONES; i++)
1600 totalpages += zones_size[i];
1601 pgdat->node_spanned_pages = totalpages;
1603 realtotalpages = totalpages;
1605 for (i = 0; i < MAX_NR_ZONES; i++)
1606 realtotalpages -= zholes_size[i];
1607 pgdat->node_present_pages = realtotalpages;
1608 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
1613 * Initially all pages are reserved - free ones are freed
1614 * up by free_all_bootmem() once the early boot process is
1615 * done. Non-atomic initialization, single-pass.
1617 void __init memmap_init_zone(unsigned long size, int nid, unsigned long zone,
1618 unsigned long start_pfn)
1620 struct page *start = pfn_to_page(start_pfn);
1623 for (page = start; page < (start + size); page++) {
1624 set_page_zone(page, NODEZONE(nid, zone));
1625 set_page_count(page, 0);
1626 reset_page_mapcount(page);
1627 SetPageReserved(page);
1628 INIT_LIST_HEAD(&page->lru);
1629 #ifdef WANT_PAGE_VIRTUAL
1630 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1631 if (!is_highmem_idx(zone))
1632 set_page_address(page, __va(start_pfn << PAGE_SHIFT));
1638 void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone,
1642 for (order = 0; order < MAX_ORDER ; order++) {
1643 INIT_LIST_HEAD(&zone->free_area[order].free_list);
1644 zone->free_area[order].nr_free = 0;
1648 #ifndef __HAVE_ARCH_MEMMAP_INIT
1649 #define memmap_init(size, nid, zone, start_pfn) \
1650 memmap_init_zone((size), (nid), (zone), (start_pfn))
1653 static int __devinit zone_batchsize(struct zone *zone)
1658 * The per-cpu-pages pools are set to around 1000th of the
1659 * size of the zone. But no more than 1/4 of a meg - there's
1660 * no point in going beyond the size of L2 cache.
1662 * OK, so we don't know how big the cache is. So guess.
1664 batch = zone->present_pages / 1024;
1665 if (batch * PAGE_SIZE > 256 * 1024)
1666 batch = (256 * 1024) / PAGE_SIZE;
1667 batch /= 4; /* We effectively *= 4 below */
1672 * Clamp the batch to a 2^n - 1 value. Having a power
1673 * of 2 value was found to be more likely to have
1674 * suboptimal cache aliasing properties in some cases.
1676 * For example if 2 tasks are alternately allocating
1677 * batches of pages, one task can end up with a lot
1678 * of pages of one half of the possible page colors
1679 * and the other with pages of the other colors.
1681 batch = (1 << fls(batch + batch/2)) - 1;
1687 * Dynamicaly allocate memory for the
1688 * per cpu pageset array in struct zone.
1690 static int __devinit process_zones(int cpu)
1692 struct zone *zone, *dzone;
1695 for_each_zone(zone) {
1696 struct per_cpu_pageset *npageset = NULL;
1698 npageset = kmalloc_node(sizeof(struct per_cpu_pageset),
1699 GFP_KERNEL, cpu_to_node(cpu));
1701 zone->pageset[cpu] = NULL;
1705 if (zone->pageset[cpu]) {
1706 memcpy(npageset, zone->pageset[cpu],
1707 sizeof(struct per_cpu_pageset));
1709 /* Relocate lists */
1710 for (i = 0; i < 2; i++) {
1711 INIT_LIST_HEAD(&npageset->pcp[i].list);
1712 list_splice(&zone->pageset[cpu]->pcp[i].list,
1713 &npageset->pcp[i].list);
1716 struct per_cpu_pages *pcp;
1717 unsigned long batch;
1719 batch = zone_batchsize(zone);
1721 pcp = &npageset->pcp[0]; /* hot */
1723 pcp->low = 2 * batch;
1724 pcp->high = 6 * batch;
1725 pcp->batch = 1 * batch;
1726 INIT_LIST_HEAD(&pcp->list);
1728 pcp = &npageset->pcp[1]; /* cold*/
1731 pcp->high = 2 * batch;
1732 pcp->batch = 1 * batch;
1733 INIT_LIST_HEAD(&pcp->list);
1735 zone->pageset[cpu] = npageset;
1740 for_each_zone(dzone) {
1743 kfree(dzone->pageset[cpu]);
1744 dzone->pageset[cpu] = NULL;
1749 static inline void free_zone_pagesets(int cpu)
1754 for_each_zone(zone) {
1755 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
1757 zone_pcp(zone, cpu) = NULL;
1763 static int __devinit pageset_cpuup_callback(struct notifier_block *nfb,
1764 unsigned long action,
1767 int cpu = (long)hcpu;
1768 int ret = NOTIFY_OK;
1771 case CPU_UP_PREPARE:
1772 if (process_zones(cpu))
1775 #ifdef CONFIG_HOTPLUG_CPU
1777 free_zone_pagesets(cpu);
1786 static struct notifier_block pageset_notifier =
1787 { &pageset_cpuup_callback, NULL, 0 };
1789 void __init setup_per_cpu_pageset()
1793 /* Initialize per_cpu_pageset for cpu 0.
1794 * A cpuup callback will do this for every cpu
1795 * as it comes online
1797 err = process_zones(smp_processor_id());
1799 register_cpu_notifier(&pageset_notifier);
1805 * Set up the zone data structures:
1806 * - mark all pages reserved
1807 * - mark all memory queues empty
1808 * - clear the memory bitmaps
1810 static void __init free_area_init_core(struct pglist_data *pgdat,
1811 unsigned long *zones_size, unsigned long *zholes_size)
1814 const unsigned long zone_required_alignment = 1UL << (MAX_ORDER-1);
1815 int cpu, nid = pgdat->node_id;
1816 unsigned long zone_start_pfn = pgdat->node_start_pfn;
1818 pgdat->nr_zones = 0;
1819 init_waitqueue_head(&pgdat->kswapd_wait);
1820 pgdat->kswapd_max_order = 0;
1822 for (j = 0; j < MAX_NR_ZONES; j++) {
1823 struct zone *zone = pgdat->node_zones + j;
1824 unsigned long size, realsize;
1825 unsigned long batch;
1827 zone_table[NODEZONE(nid, j)] = zone;
1828 realsize = size = zones_size[j];
1830 realsize -= zholes_size[j];
1832 if (j == ZONE_DMA || j == ZONE_NORMAL)
1833 nr_kernel_pages += realsize;
1834 nr_all_pages += realsize;
1836 zone->spanned_pages = size;
1837 zone->present_pages = realsize;
1838 zone->name = zone_names[j];
1839 spin_lock_init(&zone->lock);
1840 spin_lock_init(&zone->lru_lock);
1841 zone->zone_pgdat = pgdat;
1842 zone->free_pages = 0;
1844 zone->temp_priority = zone->prev_priority = DEF_PRIORITY;
1846 batch = zone_batchsize(zone);
1848 for (cpu = 0; cpu < NR_CPUS; cpu++) {
1849 struct per_cpu_pages *pcp;
1851 struct per_cpu_pageset *pgset;
1852 pgset = &pageset_table[nid*MAX_NR_ZONES*NR_CPUS +
1853 (j * NR_CPUS) + cpu];
1855 zone->pageset[cpu] = pgset;
1857 struct per_cpu_pageset *pgset = zone_pcp(zone, cpu);
1860 pcp = &pgset->pcp[0]; /* hot */
1862 pcp->low = 2 * batch;
1863 pcp->high = 6 * batch;
1864 pcp->batch = 1 * batch;
1865 INIT_LIST_HEAD(&pcp->list);
1867 pcp = &pgset->pcp[1]; /* cold */
1870 pcp->high = 2 * batch;
1871 pcp->batch = 1 * batch;
1872 INIT_LIST_HEAD(&pcp->list);
1874 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
1875 zone_names[j], realsize, batch);
1876 INIT_LIST_HEAD(&zone->active_list);
1877 INIT_LIST_HEAD(&zone->inactive_list);
1878 zone->nr_scan_active = 0;
1879 zone->nr_scan_inactive = 0;
1880 zone->nr_active = 0;
1881 zone->nr_inactive = 0;
1882 atomic_set(&zone->reclaim_in_progress, -1);
1887 * The per-page waitqueue mechanism uses hashed waitqueues
1890 zone->wait_table_size = wait_table_size(size);
1891 zone->wait_table_bits =
1892 wait_table_bits(zone->wait_table_size);
1893 zone->wait_table = (wait_queue_head_t *)
1894 alloc_bootmem_node(pgdat, zone->wait_table_size
1895 * sizeof(wait_queue_head_t));
1897 for(i = 0; i < zone->wait_table_size; ++i)
1898 init_waitqueue_head(zone->wait_table + i);
1900 pgdat->nr_zones = j+1;
1902 zone->zone_mem_map = pfn_to_page(zone_start_pfn);
1903 zone->zone_start_pfn = zone_start_pfn;
1905 if ((zone_start_pfn) & (zone_required_alignment-1))
1906 printk(KERN_CRIT "BUG: wrong zone alignment, it will crash\n");
1908 memmap_init(size, nid, j, zone_start_pfn);
1910 zone_start_pfn += size;
1912 zone_init_free_lists(pgdat, zone, zone->spanned_pages);
1916 static void __init alloc_node_mem_map(struct pglist_data *pgdat)
1920 /* Skip empty nodes */
1921 if (!pgdat->node_spanned_pages)
1924 /* ia64 gets its own node_mem_map, before this, without bootmem */
1925 if (!pgdat->node_mem_map) {
1926 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
1927 pgdat->node_mem_map = alloc_bootmem_node(pgdat, size);
1929 #ifndef CONFIG_DISCONTIGMEM
1931 * With no DISCONTIG, the global mem_map is just set as node 0's
1933 if (pgdat == NODE_DATA(0))
1934 mem_map = NODE_DATA(0)->node_mem_map;
1938 void __init free_area_init_node(int nid, struct pglist_data *pgdat,
1939 unsigned long *zones_size, unsigned long node_start_pfn,
1940 unsigned long *zholes_size)
1942 pgdat->node_id = nid;
1943 pgdat->node_start_pfn = node_start_pfn;
1944 calculate_zone_totalpages(pgdat, zones_size, zholes_size);
1946 alloc_node_mem_map(pgdat);
1948 free_area_init_core(pgdat, zones_size, zholes_size);
1951 #ifndef CONFIG_DISCONTIGMEM
1952 static bootmem_data_t contig_bootmem_data;
1953 struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
1955 EXPORT_SYMBOL(contig_page_data);
1957 void __init free_area_init(unsigned long *zones_size)
1959 free_area_init_node(0, &contig_page_data, zones_size,
1960 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
1964 #ifdef CONFIG_PROC_FS
1966 #include <linux/seq_file.h>
1968 static void *frag_start(struct seq_file *m, loff_t *pos)
1973 for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next)
1979 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
1981 pg_data_t *pgdat = (pg_data_t *)arg;
1984 return pgdat->pgdat_next;
1987 static void frag_stop(struct seq_file *m, void *arg)
1992 * This walks the free areas for each zone.
1994 static int frag_show(struct seq_file *m, void *arg)
1996 pg_data_t *pgdat = (pg_data_t *)arg;
1998 struct zone *node_zones = pgdat->node_zones;
1999 unsigned long flags;
2002 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
2003 if (!zone->present_pages)
2006 spin_lock_irqsave(&zone->lock, flags);
2007 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
2008 for (order = 0; order < MAX_ORDER; ++order)
2009 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
2010 spin_unlock_irqrestore(&zone->lock, flags);
2016 struct seq_operations fragmentation_op = {
2017 .start = frag_start,
2024 * Output information about zones in @pgdat.
2026 static int zoneinfo_show(struct seq_file *m, void *arg)
2028 pg_data_t *pgdat = arg;
2030 struct zone *node_zones = pgdat->node_zones;
2031 unsigned long flags;
2033 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
2036 if (!zone->present_pages)
2039 spin_lock_irqsave(&zone->lock, flags);
2040 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
2048 "\n scanned %lu (a: %lu i: %lu)"
2057 zone->pages_scanned,
2058 zone->nr_scan_active, zone->nr_scan_inactive,
2059 zone->spanned_pages,
2060 zone->present_pages);
2062 "\n protection: (%lu",
2063 zone->lowmem_reserve[0]);
2064 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
2065 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
2069 for (i = 0; i < ARRAY_SIZE(zone->pageset); i++) {
2070 struct per_cpu_pageset *pageset;
2073 pageset = zone_pcp(zone, i);
2074 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2075 if (pageset->pcp[j].count)
2078 if (j == ARRAY_SIZE(pageset->pcp))
2080 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2082 "\n cpu: %i pcp: %i"
2088 pageset->pcp[j].count,
2089 pageset->pcp[j].low,
2090 pageset->pcp[j].high,
2091 pageset->pcp[j].batch);
2097 "\n numa_foreign: %lu"
2098 "\n interleave_hit: %lu"
2099 "\n local_node: %lu"
2100 "\n other_node: %lu",
2103 pageset->numa_foreign,
2104 pageset->interleave_hit,
2105 pageset->local_node,
2106 pageset->other_node);
2110 "\n all_unreclaimable: %u"
2111 "\n prev_priority: %i"
2112 "\n temp_priority: %i"
2113 "\n start_pfn: %lu",
2114 zone->all_unreclaimable,
2115 zone->prev_priority,
2116 zone->temp_priority,
2117 zone->zone_start_pfn);
2118 spin_unlock_irqrestore(&zone->lock, flags);
2124 struct seq_operations zoneinfo_op = {
2125 .start = frag_start, /* iterate over all zones. The same as in
2129 .show = zoneinfo_show,
2132 static char *vmstat_text[] = {
2136 "nr_page_table_pages",
2161 "pgscan_kswapd_high",
2162 "pgscan_kswapd_normal",
2164 "pgscan_kswapd_dma",
2165 "pgscan_direct_high",
2166 "pgscan_direct_normal",
2167 "pgscan_direct_dma",
2172 "kswapd_inodesteal",
2180 static void *vmstat_start(struct seq_file *m, loff_t *pos)
2182 struct page_state *ps;
2184 if (*pos >= ARRAY_SIZE(vmstat_text))
2187 ps = kmalloc(sizeof(*ps), GFP_KERNEL);
2190 return ERR_PTR(-ENOMEM);
2191 get_full_page_state(ps);
2192 ps->pgpgin /= 2; /* sectors -> kbytes */
2194 return (unsigned long *)ps + *pos;
2197 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
2200 if (*pos >= ARRAY_SIZE(vmstat_text))
2202 return (unsigned long *)m->private + *pos;
2205 static int vmstat_show(struct seq_file *m, void *arg)
2207 unsigned long *l = arg;
2208 unsigned long off = l - (unsigned long *)m->private;
2210 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
2214 static void vmstat_stop(struct seq_file *m, void *arg)
2220 struct seq_operations vmstat_op = {
2221 .start = vmstat_start,
2222 .next = vmstat_next,
2223 .stop = vmstat_stop,
2224 .show = vmstat_show,
2227 #endif /* CONFIG_PROC_FS */
2229 #ifdef CONFIG_HOTPLUG_CPU
2230 static int page_alloc_cpu_notify(struct notifier_block *self,
2231 unsigned long action, void *hcpu)
2233 int cpu = (unsigned long)hcpu;
2235 unsigned long *src, *dest;
2237 if (action == CPU_DEAD) {
2240 /* Drain local pagecache count. */
2241 count = &per_cpu(nr_pagecache_local, cpu);
2242 atomic_add(*count, &nr_pagecache);
2244 local_irq_disable();
2247 /* Add dead cpu's page_states to our own. */
2248 dest = (unsigned long *)&__get_cpu_var(page_states);
2249 src = (unsigned long *)&per_cpu(page_states, cpu);
2251 for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long);
2261 #endif /* CONFIG_HOTPLUG_CPU */
2263 void __init page_alloc_init(void)
2265 hotcpu_notifier(page_alloc_cpu_notify, 0);
2269 * setup_per_zone_lowmem_reserve - called whenever
2270 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2271 * has a correct pages reserved value, so an adequate number of
2272 * pages are left in the zone after a successful __alloc_pages().
2274 static void setup_per_zone_lowmem_reserve(void)
2276 struct pglist_data *pgdat;
2279 for_each_pgdat(pgdat) {
2280 for (j = 0; j < MAX_NR_ZONES; j++) {
2281 struct zone *zone = pgdat->node_zones + j;
2282 unsigned long present_pages = zone->present_pages;
2284 zone->lowmem_reserve[j] = 0;
2286 for (idx = j-1; idx >= 0; idx--) {
2287 struct zone *lower_zone;
2289 if (sysctl_lowmem_reserve_ratio[idx] < 1)
2290 sysctl_lowmem_reserve_ratio[idx] = 1;
2292 lower_zone = pgdat->node_zones + idx;
2293 lower_zone->lowmem_reserve[j] = present_pages /
2294 sysctl_lowmem_reserve_ratio[idx];
2295 present_pages += lower_zone->present_pages;
2302 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures
2303 * that the pages_{min,low,high} values for each zone are set correctly
2304 * with respect to min_free_kbytes.
2306 static void setup_per_zone_pages_min(void)
2308 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
2309 unsigned long lowmem_pages = 0;
2311 unsigned long flags;
2313 /* Calculate total number of !ZONE_HIGHMEM pages */
2314 for_each_zone(zone) {
2315 if (!is_highmem(zone))
2316 lowmem_pages += zone->present_pages;
2319 for_each_zone(zone) {
2320 spin_lock_irqsave(&zone->lru_lock, flags);
2321 if (is_highmem(zone)) {
2323 * Often, highmem doesn't need to reserve any pages.
2324 * But the pages_min/low/high values are also used for
2325 * batching up page reclaim activity so we need a
2326 * decent value here.
2330 min_pages = zone->present_pages / 1024;
2331 if (min_pages < SWAP_CLUSTER_MAX)
2332 min_pages = SWAP_CLUSTER_MAX;
2333 if (min_pages > 128)
2335 zone->pages_min = min_pages;
2337 /* if it's a lowmem zone, reserve a number of pages
2338 * proportionate to the zone's size.
2340 zone->pages_min = (pages_min * zone->present_pages) /
2345 * When interpreting these watermarks, just keep in mind that:
2346 * zone->pages_min == (zone->pages_min * 4) / 4;
2348 zone->pages_low = (zone->pages_min * 5) / 4;
2349 zone->pages_high = (zone->pages_min * 6) / 4;
2350 spin_unlock_irqrestore(&zone->lru_lock, flags);
2355 * Initialise min_free_kbytes.
2357 * For small machines we want it small (128k min). For large machines
2358 * we want it large (64MB max). But it is not linear, because network
2359 * bandwidth does not increase linearly with machine size. We use
2361 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
2362 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
2378 static int __init init_per_zone_pages_min(void)
2380 unsigned long lowmem_kbytes;
2382 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
2384 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
2385 if (min_free_kbytes < 128)
2386 min_free_kbytes = 128;
2387 if (min_free_kbytes > 65536)
2388 min_free_kbytes = 65536;
2389 setup_per_zone_pages_min();
2390 setup_per_zone_lowmem_reserve();
2393 module_init(init_per_zone_pages_min)
2396 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
2397 * that we can call two helper functions whenever min_free_kbytes
2400 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
2401 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2403 proc_dointvec(table, write, file, buffer, length, ppos);
2404 setup_per_zone_pages_min();
2409 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
2410 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
2411 * whenever sysctl_lowmem_reserve_ratio changes.
2413 * The reserve ratio obviously has absolutely no relation with the
2414 * pages_min watermarks. The lowmem reserve ratio can only make sense
2415 * if in function of the boot time zone sizes.
2417 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
2418 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2420 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
2421 setup_per_zone_lowmem_reserve();
2425 __initdata int hashdist = HASHDIST_DEFAULT;
2428 static int __init set_hashdist(char *str)
2432 hashdist = simple_strtoul(str, &str, 0);
2435 __setup("hashdist=", set_hashdist);
2439 * allocate a large system hash table from bootmem
2440 * - it is assumed that the hash table must contain an exact power-of-2
2441 * quantity of entries
2442 * - limit is the number of hash buckets, not the total allocation size
2444 void *__init alloc_large_system_hash(const char *tablename,
2445 unsigned long bucketsize,
2446 unsigned long numentries,
2449 unsigned int *_hash_shift,
2450 unsigned int *_hash_mask,
2451 unsigned long limit)
2453 unsigned long long max = limit;
2454 unsigned long log2qty, size;
2457 /* allow the kernel cmdline to have a say */
2459 /* round applicable memory size up to nearest megabyte */
2460 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages;
2461 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
2462 numentries >>= 20 - PAGE_SHIFT;
2463 numentries <<= 20 - PAGE_SHIFT;
2465 /* limit to 1 bucket per 2^scale bytes of low memory */
2466 if (scale > PAGE_SHIFT)
2467 numentries >>= (scale - PAGE_SHIFT);
2469 numentries <<= (PAGE_SHIFT - scale);
2471 /* rounded up to nearest power of 2 in size */
2472 numentries = 1UL << (long_log2(numentries) + 1);
2474 /* limit allocation size to 1/16 total memory by default */
2476 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
2477 do_div(max, bucketsize);
2480 if (numentries > max)
2483 log2qty = long_log2(numentries);
2486 size = bucketsize << log2qty;
2487 if (flags & HASH_EARLY)
2488 table = alloc_bootmem(size);
2490 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
2492 unsigned long order;
2493 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
2495 table = (void*) __get_free_pages(GFP_ATOMIC, order);
2497 } while (!table && size > PAGE_SIZE && --log2qty);
2500 panic("Failed to allocate %s hash table\n", tablename);
2502 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
2505 long_log2(size) - PAGE_SHIFT,
2509 *_hash_shift = log2qty;
2511 *_hash_mask = (1 << log2qty) - 1;