2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/memory.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/ftrace_event.h>
58 #include <linux/memcontrol.h>
59 #include <linux/prefetch.h>
60 #include <linux/migrate.h>
61 #include <linux/page-debug-flags.h>
63 #include <asm/tlbflush.h>
64 #include <asm/div64.h>
67 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
68 DEFINE_PER_CPU(int, numa_node);
69 EXPORT_PER_CPU_SYMBOL(numa_node);
72 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
74 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
75 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
76 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
77 * defined in <linux/topology.h>.
79 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
80 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
84 * Array of node states.
86 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
87 [N_POSSIBLE] = NODE_MASK_ALL,
88 [N_ONLINE] = { { [0] = 1UL } },
90 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
92 [N_HIGH_MEMORY] = { { [0] = 1UL } },
94 [N_CPU] = { { [0] = 1UL } },
97 EXPORT_SYMBOL(node_states);
99 unsigned long totalram_pages __read_mostly;
100 unsigned long totalreserve_pages __read_mostly;
102 * When calculating the number of globally allowed dirty pages, there
103 * is a certain number of per-zone reserves that should not be
104 * considered dirtyable memory. This is the sum of those reserves
105 * over all existing zones that contribute dirtyable memory.
107 unsigned long dirty_balance_reserve __read_mostly;
109 int percpu_pagelist_fraction;
110 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
112 #ifdef CONFIG_PM_SLEEP
114 * The following functions are used by the suspend/hibernate code to temporarily
115 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
116 * while devices are suspended. To avoid races with the suspend/hibernate code,
117 * they should always be called with pm_mutex held (gfp_allowed_mask also should
118 * only be modified with pm_mutex held, unless the suspend/hibernate code is
119 * guaranteed not to run in parallel with that modification).
122 static gfp_t saved_gfp_mask;
124 void pm_restore_gfp_mask(void)
126 WARN_ON(!mutex_is_locked(&pm_mutex));
127 if (saved_gfp_mask) {
128 gfp_allowed_mask = saved_gfp_mask;
133 void pm_restrict_gfp_mask(void)
135 WARN_ON(!mutex_is_locked(&pm_mutex));
136 WARN_ON(saved_gfp_mask);
137 saved_gfp_mask = gfp_allowed_mask;
138 gfp_allowed_mask &= ~GFP_IOFS;
141 bool pm_suspended_storage(void)
143 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
147 #endif /* CONFIG_PM_SLEEP */
149 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
150 int pageblock_order __read_mostly;
153 static void __free_pages_ok(struct page *page, unsigned int order);
156 * results with 256, 32 in the lowmem_reserve sysctl:
157 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
158 * 1G machine -> (16M dma, 784M normal, 224M high)
159 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
160 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
161 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
163 * TBD: should special case ZONE_DMA32 machines here - in those we normally
164 * don't need any ZONE_NORMAL reservation
166 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
167 #ifdef CONFIG_ZONE_DMA
170 #ifdef CONFIG_ZONE_DMA32
173 #ifdef CONFIG_HIGHMEM
179 EXPORT_SYMBOL(totalram_pages);
181 static char * const zone_names[MAX_NR_ZONES] = {
182 #ifdef CONFIG_ZONE_DMA
185 #ifdef CONFIG_ZONE_DMA32
189 #ifdef CONFIG_HIGHMEM
195 int min_free_kbytes = 1024;
197 static unsigned long __meminitdata nr_kernel_pages;
198 static unsigned long __meminitdata nr_all_pages;
199 static unsigned long __meminitdata dma_reserve;
201 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
203 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
204 * ranges of memory (RAM) that may be registered with add_active_range().
205 * Ranges passed to add_active_range() will be merged if possible
206 * so the number of times add_active_range() can be called is
207 * related to the number of nodes and the number of holes
209 #ifdef CONFIG_MAX_ACTIVE_REGIONS
210 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
211 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
213 #if MAX_NUMNODES >= 32
214 /* If there can be many nodes, allow up to 50 holes per node */
215 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
217 /* By default, allow up to 256 distinct regions */
218 #define MAX_ACTIVE_REGIONS 256
222 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
223 static int __meminitdata nr_nodemap_entries;
224 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
225 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
226 static unsigned long __initdata required_kernelcore;
227 static unsigned long __initdata required_movablecore;
228 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
230 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
232 EXPORT_SYMBOL(movable_zone);
233 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
236 int nr_node_ids __read_mostly = MAX_NUMNODES;
237 int nr_online_nodes __read_mostly = 1;
238 EXPORT_SYMBOL(nr_node_ids);
239 EXPORT_SYMBOL(nr_online_nodes);
242 int page_group_by_mobility_disabled __read_mostly;
244 static void set_pageblock_migratetype(struct page *page, int migratetype)
247 if (unlikely(page_group_by_mobility_disabled))
248 migratetype = MIGRATE_UNMOVABLE;
250 set_pageblock_flags_group(page, (unsigned long)migratetype,
251 PB_migrate, PB_migrate_end);
254 bool oom_killer_disabled __read_mostly;
256 #ifdef CONFIG_DEBUG_VM
257 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
261 unsigned long pfn = page_to_pfn(page);
264 seq = zone_span_seqbegin(zone);
265 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
267 else if (pfn < zone->zone_start_pfn)
269 } while (zone_span_seqretry(zone, seq));
274 static int page_is_consistent(struct zone *zone, struct page *page)
276 if (!pfn_valid_within(page_to_pfn(page)))
278 if (zone != page_zone(page))
284 * Temporary debugging check for pages not lying within a given zone.
286 static int bad_range(struct zone *zone, struct page *page)
288 if (page_outside_zone_boundaries(zone, page))
290 if (!page_is_consistent(zone, page))
296 static inline int bad_range(struct zone *zone, struct page *page)
302 static void bad_page(struct page *page)
304 static unsigned long resume;
305 static unsigned long nr_shown;
306 static unsigned long nr_unshown;
308 /* Don't complain about poisoned pages */
309 if (PageHWPoison(page)) {
310 reset_page_mapcount(page); /* remove PageBuddy */
315 * Allow a burst of 60 reports, then keep quiet for that minute;
316 * or allow a steady drip of one report per second.
318 if (nr_shown == 60) {
319 if (time_before(jiffies, resume)) {
325 "BUG: Bad page state: %lu messages suppressed\n",
332 resume = jiffies + 60 * HZ;
334 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
335 current->comm, page_to_pfn(page));
341 /* Leave bad fields for debug, except PageBuddy could make trouble */
342 reset_page_mapcount(page); /* remove PageBuddy */
343 add_taint(TAINT_BAD_PAGE);
347 * Higher-order pages are called "compound pages". They are structured thusly:
349 * The first PAGE_SIZE page is called the "head page".
351 * The remaining PAGE_SIZE pages are called "tail pages".
353 * All pages have PG_compound set. All pages have their ->private pointing at
354 * the head page (even the head page has this).
356 * The first tail page's ->lru.next holds the address of the compound page's
357 * put_page() function. Its ->lru.prev holds the order of allocation.
358 * This usage means that zero-order pages may not be compound.
361 static void free_compound_page(struct page *page)
363 __free_pages_ok(page, compound_order(page));
366 void prep_compound_page(struct page *page, unsigned long order)
369 int nr_pages = 1 << order;
371 set_compound_page_dtor(page, free_compound_page);
372 set_compound_order(page, order);
374 for (i = 1; i < nr_pages; i++) {
375 struct page *p = page + i;
377 set_page_count(p, 0);
378 p->first_page = page;
382 /* update __split_huge_page_refcount if you change this function */
383 static int destroy_compound_page(struct page *page, unsigned long order)
386 int nr_pages = 1 << order;
389 if (unlikely(compound_order(page) != order) ||
390 unlikely(!PageHead(page))) {
395 __ClearPageHead(page);
397 for (i = 1; i < nr_pages; i++) {
398 struct page *p = page + i;
400 if (unlikely(!PageTail(p) || (p->first_page != page))) {
410 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
415 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
416 * and __GFP_HIGHMEM from hard or soft interrupt context.
418 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
419 for (i = 0; i < (1 << order); i++)
420 clear_highpage(page + i);
423 #ifdef CONFIG_DEBUG_PAGEALLOC
424 unsigned int _debug_guardpage_minorder;
426 static int __init debug_guardpage_minorder_setup(char *buf)
430 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
431 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
434 _debug_guardpage_minorder = res;
435 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
438 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
440 static inline void set_page_guard_flag(struct page *page)
442 __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
445 static inline void clear_page_guard_flag(struct page *page)
447 __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
450 static inline void set_page_guard_flag(struct page *page) { }
451 static inline void clear_page_guard_flag(struct page *page) { }
454 static inline void set_page_order(struct page *page, int order)
456 set_page_private(page, order);
457 __SetPageBuddy(page);
460 static inline void rmv_page_order(struct page *page)
462 __ClearPageBuddy(page);
463 set_page_private(page, 0);
467 * Locate the struct page for both the matching buddy in our
468 * pair (buddy1) and the combined O(n+1) page they form (page).
470 * 1) Any buddy B1 will have an order O twin B2 which satisfies
471 * the following equation:
473 * For example, if the starting buddy (buddy2) is #8 its order
475 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
477 * 2) Any buddy B will have an order O+1 parent P which
478 * satisfies the following equation:
481 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
483 static inline unsigned long
484 __find_buddy_index(unsigned long page_idx, unsigned int order)
486 return page_idx ^ (1 << order);
490 * This function checks whether a page is free && is the buddy
491 * we can do coalesce a page and its buddy if
492 * (a) the buddy is not in a hole &&
493 * (b) the buddy is in the buddy system &&
494 * (c) a page and its buddy have the same order &&
495 * (d) a page and its buddy are in the same zone.
497 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
498 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
500 * For recording page's order, we use page_private(page).
502 static inline int page_is_buddy(struct page *page, struct page *buddy,
505 if (!pfn_valid_within(page_to_pfn(buddy)))
508 if (page_zone_id(page) != page_zone_id(buddy))
511 if (page_is_guard(buddy) && page_order(buddy) == order) {
512 VM_BUG_ON(page_count(buddy) != 0);
516 if (PageBuddy(buddy) && page_order(buddy) == order) {
517 VM_BUG_ON(page_count(buddy) != 0);
524 * Freeing function for a buddy system allocator.
526 * The concept of a buddy system is to maintain direct-mapped table
527 * (containing bit values) for memory blocks of various "orders".
528 * The bottom level table contains the map for the smallest allocatable
529 * units of memory (here, pages), and each level above it describes
530 * pairs of units from the levels below, hence, "buddies".
531 * At a high level, all that happens here is marking the table entry
532 * at the bottom level available, and propagating the changes upward
533 * as necessary, plus some accounting needed to play nicely with other
534 * parts of the VM system.
535 * At each level, we keep a list of pages, which are heads of continuous
536 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
537 * order is recorded in page_private(page) field.
538 * So when we are allocating or freeing one, we can derive the state of the
539 * other. That is, if we allocate a small block, and both were
540 * free, the remainder of the region must be split into blocks.
541 * If a block is freed, and its buddy is also free, then this
542 * triggers coalescing into a block of larger size.
547 static inline void __free_one_page(struct page *page,
548 struct zone *zone, unsigned int order,
551 unsigned long page_idx;
552 unsigned long combined_idx;
553 unsigned long uninitialized_var(buddy_idx);
556 if (unlikely(PageCompound(page)))
557 if (unlikely(destroy_compound_page(page, order)))
560 VM_BUG_ON(migratetype == -1);
562 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
564 VM_BUG_ON(page_idx & ((1 << order) - 1));
565 VM_BUG_ON(bad_range(zone, page));
567 while (order < MAX_ORDER-1) {
568 buddy_idx = __find_buddy_index(page_idx, order);
569 buddy = page + (buddy_idx - page_idx);
570 if (!page_is_buddy(page, buddy, order))
573 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
574 * merge with it and move up one order.
576 if (page_is_guard(buddy)) {
577 clear_page_guard_flag(buddy);
578 set_page_private(page, 0);
579 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
581 list_del(&buddy->lru);
582 zone->free_area[order].nr_free--;
583 rmv_page_order(buddy);
585 combined_idx = buddy_idx & page_idx;
586 page = page + (combined_idx - page_idx);
587 page_idx = combined_idx;
590 set_page_order(page, order);
593 * If this is not the largest possible page, check if the buddy
594 * of the next-highest order is free. If it is, it's possible
595 * that pages are being freed that will coalesce soon. In case,
596 * that is happening, add the free page to the tail of the list
597 * so it's less likely to be used soon and more likely to be merged
598 * as a higher order page
600 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
601 struct page *higher_page, *higher_buddy;
602 combined_idx = buddy_idx & page_idx;
603 higher_page = page + (combined_idx - page_idx);
604 buddy_idx = __find_buddy_index(combined_idx, order + 1);
605 higher_buddy = higher_page + (buddy_idx - combined_idx);
606 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
607 list_add_tail(&page->lru,
608 &zone->free_area[order].free_list[migratetype]);
613 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
615 zone->free_area[order].nr_free++;
619 * free_page_mlock() -- clean up attempts to free and mlocked() page.
620 * Page should not be on lru, so no need to fix that up.
621 * free_pages_check() will verify...
623 static inline void free_page_mlock(struct page *page)
625 __dec_zone_page_state(page, NR_MLOCK);
626 __count_vm_event(UNEVICTABLE_MLOCKFREED);
629 static inline int free_pages_check(struct page *page)
631 if (unlikely(page_mapcount(page) |
632 (page->mapping != NULL) |
633 (atomic_read(&page->_count) != 0) |
634 (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
635 (mem_cgroup_bad_page_check(page)))) {
639 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
640 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
645 * Frees a number of pages from the PCP lists
646 * Assumes all pages on list are in same zone, and of same order.
647 * count is the number of pages to free.
649 * If the zone was previously in an "all pages pinned" state then look to
650 * see if this freeing clears that state.
652 * And clear the zone's pages_scanned counter, to hold off the "all pages are
653 * pinned" detection logic.
655 static void free_pcppages_bulk(struct zone *zone, int count,
656 struct per_cpu_pages *pcp)
662 spin_lock(&zone->lock);
663 zone->all_unreclaimable = 0;
664 zone->pages_scanned = 0;
668 struct list_head *list;
671 * Remove pages from lists in a round-robin fashion. A
672 * batch_free count is maintained that is incremented when an
673 * empty list is encountered. This is so more pages are freed
674 * off fuller lists instead of spinning excessively around empty
679 if (++migratetype == MIGRATE_PCPTYPES)
681 list = &pcp->lists[migratetype];
682 } while (list_empty(list));
684 /* This is the only non-empty list. Free them all. */
685 if (batch_free == MIGRATE_PCPTYPES)
686 batch_free = to_free;
689 page = list_entry(list->prev, struct page, lru);
690 /* must delete as __free_one_page list manipulates */
691 list_del(&page->lru);
692 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
693 __free_one_page(page, zone, 0, page_private(page));
694 trace_mm_page_pcpu_drain(page, 0, page_private(page));
695 } while (--to_free && --batch_free && !list_empty(list));
697 __mod_zone_page_state(zone, NR_FREE_PAGES, count);
698 spin_unlock(&zone->lock);
701 static void free_one_page(struct zone *zone, struct page *page, int order,
704 spin_lock(&zone->lock);
705 zone->all_unreclaimable = 0;
706 zone->pages_scanned = 0;
708 __free_one_page(page, zone, order, migratetype);
709 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
710 spin_unlock(&zone->lock);
713 static bool free_pages_prepare(struct page *page, unsigned int order)
718 trace_mm_page_free(page, order);
719 kmemcheck_free_shadow(page, order);
722 page->mapping = NULL;
723 for (i = 0; i < (1 << order); i++)
724 bad += free_pages_check(page + i);
728 if (!PageHighMem(page)) {
729 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
730 debug_check_no_obj_freed(page_address(page),
733 arch_free_page(page, order);
734 kernel_map_pages(page, 1 << order, 0);
739 static void __free_pages_ok(struct page *page, unsigned int order)
742 int wasMlocked = __TestClearPageMlocked(page);
744 if (!free_pages_prepare(page, order))
747 local_irq_save(flags);
748 if (unlikely(wasMlocked))
749 free_page_mlock(page);
750 __count_vm_events(PGFREE, 1 << order);
751 free_one_page(page_zone(page), page, order,
752 get_pageblock_migratetype(page));
753 local_irq_restore(flags);
757 * permit the bootmem allocator to evade page validation on high-order frees
759 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
762 __ClearPageReserved(page);
763 set_page_count(page, 0);
764 set_page_refcounted(page);
770 for (loop = 0; loop < BITS_PER_LONG; loop++) {
771 struct page *p = &page[loop];
773 if (loop + 1 < BITS_PER_LONG)
775 __ClearPageReserved(p);
776 set_page_count(p, 0);
779 set_page_refcounted(page);
780 __free_pages(page, order);
785 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
786 void __init init_cma_reserved_pageblock(struct page *page)
788 unsigned i = pageblock_nr_pages;
789 struct page *p = page;
792 __ClearPageReserved(p);
793 set_page_count(p, 0);
796 set_page_refcounted(page);
797 set_pageblock_migratetype(page, MIGRATE_CMA);
798 __free_pages(page, pageblock_order);
799 totalram_pages += pageblock_nr_pages;
804 * The order of subdivision here is critical for the IO subsystem.
805 * Please do not alter this order without good reasons and regression
806 * testing. Specifically, as large blocks of memory are subdivided,
807 * the order in which smaller blocks are delivered depends on the order
808 * they're subdivided in this function. This is the primary factor
809 * influencing the order in which pages are delivered to the IO
810 * subsystem according to empirical testing, and this is also justified
811 * by considering the behavior of a buddy system containing a single
812 * large block of memory acted on by a series of small allocations.
813 * This behavior is a critical factor in sglist merging's success.
817 static inline void expand(struct zone *zone, struct page *page,
818 int low, int high, struct free_area *area,
821 unsigned long size = 1 << high;
827 VM_BUG_ON(bad_range(zone, &page[size]));
829 #ifdef CONFIG_DEBUG_PAGEALLOC
830 if (high < debug_guardpage_minorder()) {
832 * Mark as guard pages (or page), that will allow to
833 * merge back to allocator when buddy will be freed.
834 * Corresponding page table entries will not be touched,
835 * pages will stay not present in virtual address space
837 INIT_LIST_HEAD(&page[size].lru);
838 set_page_guard_flag(&page[size]);
839 set_page_private(&page[size], high);
840 /* Guard pages are not available for any usage */
841 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << high));
845 list_add(&page[size].lru, &area->free_list[migratetype]);
847 set_page_order(&page[size], high);
852 * This page is about to be returned from the page allocator
854 static inline int check_new_page(struct page *page)
856 if (unlikely(page_mapcount(page) |
857 (page->mapping != NULL) |
858 (atomic_read(&page->_count) != 0) |
859 (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
860 (mem_cgroup_bad_page_check(page)))) {
867 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
871 for (i = 0; i < (1 << order); i++) {
872 struct page *p = page + i;
873 if (unlikely(check_new_page(p)))
877 set_page_private(page, 0);
878 set_page_refcounted(page);
880 arch_alloc_page(page, order);
881 kernel_map_pages(page, 1 << order, 1);
883 if (gfp_flags & __GFP_ZERO)
884 prep_zero_page(page, order, gfp_flags);
886 if (order && (gfp_flags & __GFP_COMP))
887 prep_compound_page(page, order);
893 * Go through the free lists for the given migratetype and remove
894 * the smallest available page from the freelists
897 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
900 unsigned int current_order;
901 struct free_area * area;
904 /* Find a page of the appropriate size in the preferred list */
905 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
906 area = &(zone->free_area[current_order]);
907 if (list_empty(&area->free_list[migratetype]))
910 page = list_entry(area->free_list[migratetype].next,
912 list_del(&page->lru);
913 rmv_page_order(page);
915 expand(zone, page, order, current_order, area, migratetype);
924 * This array describes the order lists are fallen back to when
925 * the free lists for the desirable migrate type are depleted
927 static int fallbacks[MIGRATE_TYPES][4] = {
928 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
929 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
931 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
932 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
934 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
936 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
937 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
941 * Move the free pages in a range to the free lists of the requested type.
942 * Note that start_page and end_pages are not aligned on a pageblock
943 * boundary. If alignment is required, use move_freepages_block()
945 static int move_freepages(struct zone *zone,
946 struct page *start_page, struct page *end_page,
953 #ifndef CONFIG_HOLES_IN_ZONE
955 * page_zone is not safe to call in this context when
956 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
957 * anyway as we check zone boundaries in move_freepages_block().
958 * Remove at a later date when no bug reports exist related to
959 * grouping pages by mobility
961 BUG_ON(page_zone(start_page) != page_zone(end_page));
964 for (page = start_page; page <= end_page;) {
965 /* Make sure we are not inadvertently changing nodes */
966 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
968 if (!pfn_valid_within(page_to_pfn(page))) {
973 if (!PageBuddy(page)) {
978 order = page_order(page);
979 list_move(&page->lru,
980 &zone->free_area[order].free_list[migratetype]);
982 pages_moved += 1 << order;
988 static int move_freepages_block(struct zone *zone, struct page *page,
991 unsigned long start_pfn, end_pfn;
992 struct page *start_page, *end_page;
994 start_pfn = page_to_pfn(page);
995 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
996 start_page = pfn_to_page(start_pfn);
997 end_page = start_page + pageblock_nr_pages - 1;
998 end_pfn = start_pfn + pageblock_nr_pages - 1;
1000 /* Do not cross zone boundaries */
1001 if (start_pfn < zone->zone_start_pfn)
1003 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
1006 return move_freepages(zone, start_page, end_page, migratetype);
1009 static void change_pageblock_range(struct page *pageblock_page,
1010 int start_order, int migratetype)
1012 int nr_pageblocks = 1 << (start_order - pageblock_order);
1014 while (nr_pageblocks--) {
1015 set_pageblock_migratetype(pageblock_page, migratetype);
1016 pageblock_page += pageblock_nr_pages;
1020 /* Remove an element from the buddy allocator from the fallback list */
1021 static inline struct page *
1022 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
1024 struct free_area * area;
1029 /* Find the largest possible block of pages in the other list */
1030 for (current_order = MAX_ORDER-1; current_order >= order;
1033 migratetype = fallbacks[start_migratetype][i];
1035 /* MIGRATE_RESERVE handled later if necessary */
1036 if (migratetype == MIGRATE_RESERVE)
1039 area = &(zone->free_area[current_order]);
1040 if (list_empty(&area->free_list[migratetype]))
1043 page = list_entry(area->free_list[migratetype].next,
1048 * If breaking a large block of pages, move all free
1049 * pages to the preferred allocation list. If falling
1050 * back for a reclaimable kernel allocation, be more
1051 * aggressive about taking ownership of free pages
1053 * On the other hand, never change migration
1054 * type of MIGRATE_CMA pageblocks nor move CMA
1055 * pages on different free lists. We don't
1056 * want unmovable pages to be allocated from
1057 * MIGRATE_CMA areas.
1059 if (!is_migrate_cma(migratetype) &&
1060 (unlikely(current_order >= pageblock_order / 2) ||
1061 start_migratetype == MIGRATE_RECLAIMABLE ||
1062 page_group_by_mobility_disabled)) {
1064 pages = move_freepages_block(zone, page,
1067 /* Claim the whole block if over half of it is free */
1068 if (pages >= (1 << (pageblock_order-1)) ||
1069 page_group_by_mobility_disabled)
1070 set_pageblock_migratetype(page,
1073 migratetype = start_migratetype;
1076 /* Remove the page from the freelists */
1077 list_del(&page->lru);
1078 rmv_page_order(page);
1080 /* Take ownership for orders >= pageblock_order */
1081 if (current_order >= pageblock_order &&
1082 !is_migrate_cma(migratetype))
1083 change_pageblock_range(page, current_order,
1086 expand(zone, page, order, current_order, area,
1087 is_migrate_cma(migratetype)
1088 ? migratetype : start_migratetype);
1090 trace_mm_page_alloc_extfrag(page, order, current_order,
1091 start_migratetype, migratetype);
1101 * Do the hard work of removing an element from the buddy allocator.
1102 * Call me with the zone->lock already held.
1104 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1110 page = __rmqueue_smallest(zone, order, migratetype);
1112 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1113 page = __rmqueue_fallback(zone, order, migratetype);
1116 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1117 * is used because __rmqueue_smallest is an inline function
1118 * and we want just one call site
1121 migratetype = MIGRATE_RESERVE;
1126 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1131 * Obtain a specified number of elements from the buddy allocator, all under
1132 * a single hold of the lock, for efficiency. Add them to the supplied list.
1133 * Returns the number of new pages which were placed at *list.
1135 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1136 unsigned long count, struct list_head *list,
1137 int migratetype, int cold)
1139 int mt = migratetype, i;
1141 spin_lock(&zone->lock);
1142 for (i = 0; i < count; ++i) {
1143 struct page *page = __rmqueue(zone, order, migratetype);
1144 if (unlikely(page == NULL))
1148 * Split buddy pages returned by expand() are received here
1149 * in physical page order. The page is added to the callers and
1150 * list and the list head then moves forward. From the callers
1151 * perspective, the linked list is ordered by page number in
1152 * some conditions. This is useful for IO devices that can
1153 * merge IO requests if the physical pages are ordered
1156 if (likely(cold == 0))
1157 list_add(&page->lru, list);
1159 list_add_tail(&page->lru, list);
1160 if (IS_ENABLED(CONFIG_CMA)) {
1161 mt = get_pageblock_migratetype(page);
1162 if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
1165 set_page_private(page, mt);
1168 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1169 spin_unlock(&zone->lock);
1175 * Called from the vmstat counter updater to drain pagesets of this
1176 * currently executing processor on remote nodes after they have
1179 * Note that this function must be called with the thread pinned to
1180 * a single processor.
1182 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1184 unsigned long flags;
1187 local_irq_save(flags);
1188 if (pcp->count >= pcp->batch)
1189 to_drain = pcp->batch;
1191 to_drain = pcp->count;
1192 free_pcppages_bulk(zone, to_drain, pcp);
1193 pcp->count -= to_drain;
1194 local_irq_restore(flags);
1199 * Drain pages of the indicated processor.
1201 * The processor must either be the current processor and the
1202 * thread pinned to the current processor or a processor that
1205 static void drain_pages(unsigned int cpu)
1207 unsigned long flags;
1210 for_each_populated_zone(zone) {
1211 struct per_cpu_pageset *pset;
1212 struct per_cpu_pages *pcp;
1214 local_irq_save(flags);
1215 pset = per_cpu_ptr(zone->pageset, cpu);
1219 free_pcppages_bulk(zone, pcp->count, pcp);
1222 local_irq_restore(flags);
1227 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1229 void drain_local_pages(void *arg)
1231 drain_pages(smp_processor_id());
1235 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1237 void drain_all_pages(void)
1239 on_each_cpu(drain_local_pages, NULL, 1);
1242 #ifdef CONFIG_HIBERNATION
1244 void mark_free_pages(struct zone *zone)
1246 unsigned long pfn, max_zone_pfn;
1247 unsigned long flags;
1249 struct list_head *curr;
1251 if (!zone->spanned_pages)
1254 spin_lock_irqsave(&zone->lock, flags);
1256 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1257 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1258 if (pfn_valid(pfn)) {
1259 struct page *page = pfn_to_page(pfn);
1261 if (!swsusp_page_is_forbidden(page))
1262 swsusp_unset_page_free(page);
1265 for_each_migratetype_order(order, t) {
1266 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1269 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1270 for (i = 0; i < (1UL << order); i++)
1271 swsusp_set_page_free(pfn_to_page(pfn + i));
1274 spin_unlock_irqrestore(&zone->lock, flags);
1276 #endif /* CONFIG_PM */
1279 * Free a 0-order page
1280 * cold == 1 ? free a cold page : free a hot page
1282 void free_hot_cold_page(struct page *page, int cold)
1284 struct zone *zone = page_zone(page);
1285 struct per_cpu_pages *pcp;
1286 unsigned long flags;
1288 int wasMlocked = __TestClearPageMlocked(page);
1290 if (!free_pages_prepare(page, 0))
1293 migratetype = get_pageblock_migratetype(page);
1294 set_page_private(page, migratetype);
1295 local_irq_save(flags);
1296 if (unlikely(wasMlocked))
1297 free_page_mlock(page);
1298 __count_vm_event(PGFREE);
1301 * We only track unmovable, reclaimable and movable on pcp lists.
1302 * Free ISOLATE pages back to the allocator because they are being
1303 * offlined but treat RESERVE as movable pages so we can get those
1304 * areas back if necessary. Otherwise, we may have to free
1305 * excessively into the page allocator
1307 if (migratetype >= MIGRATE_PCPTYPES) {
1308 if (unlikely(migratetype == MIGRATE_ISOLATE)) {
1309 free_one_page(zone, page, 0, migratetype);
1312 migratetype = MIGRATE_MOVABLE;
1315 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1317 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1319 list_add(&page->lru, &pcp->lists[migratetype]);
1321 if (pcp->count >= pcp->high) {
1322 free_pcppages_bulk(zone, pcp->batch, pcp);
1323 pcp->count -= pcp->batch;
1327 local_irq_restore(flags);
1331 * Free a list of 0-order pages
1333 void free_hot_cold_page_list(struct list_head *list, int cold)
1335 struct page *page, *next;
1337 list_for_each_entry_safe(page, next, list, lru) {
1338 trace_mm_page_free_batched(page, cold);
1339 free_hot_cold_page(page, cold);
1344 * split_page takes a non-compound higher-order page, and splits it into
1345 * n (1<<order) sub-pages: page[0..n]
1346 * Each sub-page must be freed individually.
1348 * Note: this is probably too low level an operation for use in drivers.
1349 * Please consult with lkml before using this in your driver.
1351 void split_page(struct page *page, unsigned int order)
1355 VM_BUG_ON(PageCompound(page));
1356 VM_BUG_ON(!page_count(page));
1358 #ifdef CONFIG_KMEMCHECK
1360 * Split shadow pages too, because free(page[0]) would
1361 * otherwise free the whole shadow.
1363 if (kmemcheck_page_is_tracked(page))
1364 split_page(virt_to_page(page[0].shadow), order);
1367 for (i = 1; i < (1 << order); i++)
1368 set_page_refcounted(page + i);
1372 * Similar to split_page except the page is already free. As this is only
1373 * being used for migration, the migratetype of the block also changes.
1374 * As this is called with interrupts disabled, the caller is responsible
1375 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1378 * Note: this is probably too low level an operation for use in drivers.
1379 * Please consult with lkml before using this in your driver.
1381 int split_free_page(struct page *page)
1384 unsigned long watermark;
1387 BUG_ON(!PageBuddy(page));
1389 zone = page_zone(page);
1390 order = page_order(page);
1392 /* Obey watermarks as if the page was being allocated */
1393 watermark = low_wmark_pages(zone) + (1 << order);
1394 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1397 /* Remove page from free list */
1398 list_del(&page->lru);
1399 zone->free_area[order].nr_free--;
1400 rmv_page_order(page);
1401 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
1403 /* Split into individual pages */
1404 set_page_refcounted(page);
1405 split_page(page, order);
1407 if (order >= pageblock_order - 1) {
1408 struct page *endpage = page + (1 << order) - 1;
1409 for (; page < endpage; page += pageblock_nr_pages) {
1410 int mt = get_pageblock_migratetype(page);
1411 if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt))
1412 set_pageblock_migratetype(page,
1421 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1422 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1426 struct page *buffered_rmqueue(struct zone *preferred_zone,
1427 struct zone *zone, int order, gfp_t gfp_flags,
1430 unsigned long flags;
1432 int cold = !!(gfp_flags & __GFP_COLD);
1435 if (likely(order == 0)) {
1436 struct per_cpu_pages *pcp;
1437 struct list_head *list;
1439 local_irq_save(flags);
1440 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1441 list = &pcp->lists[migratetype];
1442 if (list_empty(list)) {
1443 pcp->count += rmqueue_bulk(zone, 0,
1446 if (unlikely(list_empty(list)))
1451 page = list_entry(list->prev, struct page, lru);
1453 page = list_entry(list->next, struct page, lru);
1455 list_del(&page->lru);
1458 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1460 * __GFP_NOFAIL is not to be used in new code.
1462 * All __GFP_NOFAIL callers should be fixed so that they
1463 * properly detect and handle allocation failures.
1465 * We most definitely don't want callers attempting to
1466 * allocate greater than order-1 page units with
1469 WARN_ON_ONCE(order > 1);
1471 spin_lock_irqsave(&zone->lock, flags);
1472 page = __rmqueue(zone, order, migratetype);
1473 spin_unlock(&zone->lock);
1476 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
1479 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1480 zone_statistics(preferred_zone, zone, gfp_flags);
1481 local_irq_restore(flags);
1483 VM_BUG_ON(bad_range(zone, page));
1484 if (prep_new_page(page, order, gfp_flags))
1489 local_irq_restore(flags);
1493 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1494 #define ALLOC_WMARK_MIN WMARK_MIN
1495 #define ALLOC_WMARK_LOW WMARK_LOW
1496 #define ALLOC_WMARK_HIGH WMARK_HIGH
1497 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1499 /* Mask to get the watermark bits */
1500 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1502 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1503 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1504 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1506 #ifdef CONFIG_FAIL_PAGE_ALLOC
1509 struct fault_attr attr;
1511 u32 ignore_gfp_highmem;
1512 u32 ignore_gfp_wait;
1514 } fail_page_alloc = {
1515 .attr = FAULT_ATTR_INITIALIZER,
1516 .ignore_gfp_wait = 1,
1517 .ignore_gfp_highmem = 1,
1521 static int __init setup_fail_page_alloc(char *str)
1523 return setup_fault_attr(&fail_page_alloc.attr, str);
1525 __setup("fail_page_alloc=", setup_fail_page_alloc);
1527 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1529 if (order < fail_page_alloc.min_order)
1531 if (gfp_mask & __GFP_NOFAIL)
1533 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1535 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1538 return should_fail(&fail_page_alloc.attr, 1 << order);
1541 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1543 static int __init fail_page_alloc_debugfs(void)
1545 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1548 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1549 &fail_page_alloc.attr);
1551 return PTR_ERR(dir);
1553 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1554 &fail_page_alloc.ignore_gfp_wait))
1556 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1557 &fail_page_alloc.ignore_gfp_highmem))
1559 if (!debugfs_create_u32("min-order", mode, dir,
1560 &fail_page_alloc.min_order))
1565 debugfs_remove_recursive(dir);
1570 late_initcall(fail_page_alloc_debugfs);
1572 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1574 #else /* CONFIG_FAIL_PAGE_ALLOC */
1576 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1581 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1584 * Return true if free pages are above 'mark'. This takes into account the order
1585 * of the allocation.
1587 static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1588 int classzone_idx, int alloc_flags, long free_pages)
1590 /* free_pages my go negative - that's OK */
1594 free_pages -= (1 << order) - 1;
1595 if (alloc_flags & ALLOC_HIGH)
1597 if (alloc_flags & ALLOC_HARDER)
1600 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1602 for (o = 0; o < order; o++) {
1603 /* At the next order, this order's pages become unavailable */
1604 free_pages -= z->free_area[o].nr_free << o;
1606 /* Require fewer higher order pages to be free */
1609 if (free_pages <= min)
1615 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1616 int classzone_idx, int alloc_flags)
1618 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1619 zone_page_state(z, NR_FREE_PAGES));
1622 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
1623 int classzone_idx, int alloc_flags)
1625 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1627 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1628 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1630 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1636 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1637 * skip over zones that are not allowed by the cpuset, or that have
1638 * been recently (in last second) found to be nearly full. See further
1639 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1640 * that have to skip over a lot of full or unallowed zones.
1642 * If the zonelist cache is present in the passed in zonelist, then
1643 * returns a pointer to the allowed node mask (either the current
1644 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1646 * If the zonelist cache is not available for this zonelist, does
1647 * nothing and returns NULL.
1649 * If the fullzones BITMAP in the zonelist cache is stale (more than
1650 * a second since last zap'd) then we zap it out (clear its bits.)
1652 * We hold off even calling zlc_setup, until after we've checked the
1653 * first zone in the zonelist, on the theory that most allocations will
1654 * be satisfied from that first zone, so best to examine that zone as
1655 * quickly as we can.
1657 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1659 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1660 nodemask_t *allowednodes; /* zonelist_cache approximation */
1662 zlc = zonelist->zlcache_ptr;
1666 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1667 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1668 zlc->last_full_zap = jiffies;
1671 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1672 &cpuset_current_mems_allowed :
1673 &node_states[N_HIGH_MEMORY];
1674 return allowednodes;
1678 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1679 * if it is worth looking at further for free memory:
1680 * 1) Check that the zone isn't thought to be full (doesn't have its
1681 * bit set in the zonelist_cache fullzones BITMAP).
1682 * 2) Check that the zones node (obtained from the zonelist_cache
1683 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1684 * Return true (non-zero) if zone is worth looking at further, or
1685 * else return false (zero) if it is not.
1687 * This check -ignores- the distinction between various watermarks,
1688 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1689 * found to be full for any variation of these watermarks, it will
1690 * be considered full for up to one second by all requests, unless
1691 * we are so low on memory on all allowed nodes that we are forced
1692 * into the second scan of the zonelist.
1694 * In the second scan we ignore this zonelist cache and exactly
1695 * apply the watermarks to all zones, even it is slower to do so.
1696 * We are low on memory in the second scan, and should leave no stone
1697 * unturned looking for a free page.
1699 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1700 nodemask_t *allowednodes)
1702 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1703 int i; /* index of *z in zonelist zones */
1704 int n; /* node that zone *z is on */
1706 zlc = zonelist->zlcache_ptr;
1710 i = z - zonelist->_zonerefs;
1713 /* This zone is worth trying if it is allowed but not full */
1714 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1718 * Given 'z' scanning a zonelist, set the corresponding bit in
1719 * zlc->fullzones, so that subsequent attempts to allocate a page
1720 * from that zone don't waste time re-examining it.
1722 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1724 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1725 int i; /* index of *z in zonelist zones */
1727 zlc = zonelist->zlcache_ptr;
1731 i = z - zonelist->_zonerefs;
1733 set_bit(i, zlc->fullzones);
1737 * clear all zones full, called after direct reclaim makes progress so that
1738 * a zone that was recently full is not skipped over for up to a second
1740 static void zlc_clear_zones_full(struct zonelist *zonelist)
1742 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1744 zlc = zonelist->zlcache_ptr;
1748 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1751 #else /* CONFIG_NUMA */
1753 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1758 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1759 nodemask_t *allowednodes)
1764 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1768 static void zlc_clear_zones_full(struct zonelist *zonelist)
1771 #endif /* CONFIG_NUMA */
1774 * get_page_from_freelist goes through the zonelist trying to allocate
1777 static struct page *
1778 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1779 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1780 struct zone *preferred_zone, int migratetype)
1783 struct page *page = NULL;
1786 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1787 int zlc_active = 0; /* set if using zonelist_cache */
1788 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1790 classzone_idx = zone_idx(preferred_zone);
1793 * Scan zonelist, looking for a zone with enough free.
1794 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1796 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1797 high_zoneidx, nodemask) {
1798 if (NUMA_BUILD && zlc_active &&
1799 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1801 if ((alloc_flags & ALLOC_CPUSET) &&
1802 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1805 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1806 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1810 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1811 if (zone_watermark_ok(zone, order, mark,
1812 classzone_idx, alloc_flags))
1815 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1817 * we do zlc_setup if there are multiple nodes
1818 * and before considering the first zone allowed
1821 allowednodes = zlc_setup(zonelist, alloc_flags);
1826 if (zone_reclaim_mode == 0)
1827 goto this_zone_full;
1830 * As we may have just activated ZLC, check if the first
1831 * eligible zone has failed zone_reclaim recently.
1833 if (NUMA_BUILD && zlc_active &&
1834 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1837 ret = zone_reclaim(zone, gfp_mask, order);
1839 case ZONE_RECLAIM_NOSCAN:
1842 case ZONE_RECLAIM_FULL:
1843 /* scanned but unreclaimable */
1846 /* did we reclaim enough */
1847 if (!zone_watermark_ok(zone, order, mark,
1848 classzone_idx, alloc_flags))
1849 goto this_zone_full;
1854 page = buffered_rmqueue(preferred_zone, zone, order,
1855 gfp_mask, migratetype);
1860 zlc_mark_zone_full(zonelist, z);
1863 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1864 /* Disable zlc cache for second zonelist scan */
1872 * Large machines with many possible nodes should not always dump per-node
1873 * meminfo in irq context.
1875 static inline bool should_suppress_show_mem(void)
1880 ret = in_interrupt();
1885 static DEFINE_RATELIMIT_STATE(nopage_rs,
1886 DEFAULT_RATELIMIT_INTERVAL,
1887 DEFAULT_RATELIMIT_BURST);
1889 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
1891 unsigned int filter = SHOW_MEM_FILTER_NODES;
1893 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
1894 debug_guardpage_minorder() > 0)
1898 * Walking all memory to count page types is very expensive and should
1899 * be inhibited in non-blockable contexts.
1901 if (!(gfp_mask & __GFP_WAIT))
1902 filter |= SHOW_MEM_FILTER_PAGE_COUNT;
1905 * This documents exceptions given to allocations in certain
1906 * contexts that are allowed to allocate outside current's set
1909 if (!(gfp_mask & __GFP_NOMEMALLOC))
1910 if (test_thread_flag(TIF_MEMDIE) ||
1911 (current->flags & (PF_MEMALLOC | PF_EXITING)))
1912 filter &= ~SHOW_MEM_FILTER_NODES;
1913 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
1914 filter &= ~SHOW_MEM_FILTER_NODES;
1917 struct va_format vaf;
1920 va_start(args, fmt);
1925 pr_warn("%pV", &vaf);
1930 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
1931 current->comm, order, gfp_mask);
1934 if (!should_suppress_show_mem())
1939 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
1940 unsigned long did_some_progress,
1941 unsigned long pages_reclaimed)
1943 /* Do not loop if specifically requested */
1944 if (gfp_mask & __GFP_NORETRY)
1947 /* Always retry if specifically requested */
1948 if (gfp_mask & __GFP_NOFAIL)
1952 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
1953 * making forward progress without invoking OOM. Suspend also disables
1954 * storage devices so kswapd will not help. Bail if we are suspending.
1956 if (!did_some_progress && pm_suspended_storage())
1960 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1961 * means __GFP_NOFAIL, but that may not be true in other
1964 if (order <= PAGE_ALLOC_COSTLY_ORDER)
1968 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1969 * specified, then we retry until we no longer reclaim any pages
1970 * (above), or we've reclaimed an order of pages at least as
1971 * large as the allocation's order. In both cases, if the
1972 * allocation still fails, we stop retrying.
1974 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
1980 static inline struct page *
1981 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
1982 struct zonelist *zonelist, enum zone_type high_zoneidx,
1983 nodemask_t *nodemask, struct zone *preferred_zone,
1988 /* Acquire the OOM killer lock for the zones in zonelist */
1989 if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
1990 schedule_timeout_uninterruptible(1);
1995 * Go through the zonelist yet one more time, keep very high watermark
1996 * here, this is only to catch a parallel oom killing, we must fail if
1997 * we're still under heavy pressure.
1999 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
2000 order, zonelist, high_zoneidx,
2001 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2002 preferred_zone, migratetype);
2006 if (!(gfp_mask & __GFP_NOFAIL)) {
2007 /* The OOM killer will not help higher order allocs */
2008 if (order > PAGE_ALLOC_COSTLY_ORDER)
2010 /* The OOM killer does not needlessly kill tasks for lowmem */
2011 if (high_zoneidx < ZONE_NORMAL)
2014 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2015 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2016 * The caller should handle page allocation failure by itself if
2017 * it specifies __GFP_THISNODE.
2018 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2020 if (gfp_mask & __GFP_THISNODE)
2023 /* Exhausted what can be done so it's blamo time */
2024 out_of_memory(zonelist, gfp_mask, order, nodemask);
2027 clear_zonelist_oom(zonelist, gfp_mask);
2031 #ifdef CONFIG_COMPACTION
2032 /* Try memory compaction for high-order allocations before reclaim */
2033 static struct page *
2034 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2035 struct zonelist *zonelist, enum zone_type high_zoneidx,
2036 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2037 int migratetype, bool sync_migration,
2038 bool *deferred_compaction,
2039 unsigned long *did_some_progress)
2046 if (compaction_deferred(preferred_zone)) {
2047 *deferred_compaction = true;
2051 current->flags |= PF_MEMALLOC;
2052 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2053 nodemask, sync_migration);
2054 current->flags &= ~PF_MEMALLOC;
2055 if (*did_some_progress != COMPACT_SKIPPED) {
2057 /* Page migration frees to the PCP lists but we want merging */
2058 drain_pages(get_cpu());
2061 page = get_page_from_freelist(gfp_mask, nodemask,
2062 order, zonelist, high_zoneidx,
2063 alloc_flags, preferred_zone,
2066 preferred_zone->compact_considered = 0;
2067 preferred_zone->compact_defer_shift = 0;
2068 count_vm_event(COMPACTSUCCESS);
2073 * It's bad if compaction run occurs and fails.
2074 * The most likely reason is that pages exist,
2075 * but not enough to satisfy watermarks.
2077 count_vm_event(COMPACTFAIL);
2080 * As async compaction considers a subset of pageblocks, only
2081 * defer if the failure was a sync compaction failure.
2084 defer_compaction(preferred_zone);
2092 static inline struct page *
2093 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2094 struct zonelist *zonelist, enum zone_type high_zoneidx,
2095 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2096 int migratetype, bool sync_migration,
2097 bool *deferred_compaction,
2098 unsigned long *did_some_progress)
2102 #endif /* CONFIG_COMPACTION */
2104 /* Perform direct synchronous page reclaim */
2106 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
2107 nodemask_t *nodemask)
2109 struct reclaim_state reclaim_state;
2114 /* We now go into synchronous reclaim */
2115 cpuset_memory_pressure_bump();
2116 current->flags |= PF_MEMALLOC;
2117 lockdep_set_current_reclaim_state(gfp_mask);
2118 reclaim_state.reclaimed_slab = 0;
2119 current->reclaim_state = &reclaim_state;
2121 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2123 current->reclaim_state = NULL;
2124 lockdep_clear_current_reclaim_state();
2125 current->flags &= ~PF_MEMALLOC;
2132 /* The really slow allocator path where we enter direct reclaim */
2133 static inline struct page *
2134 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2135 struct zonelist *zonelist, enum zone_type high_zoneidx,
2136 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2137 int migratetype, unsigned long *did_some_progress)
2139 struct page *page = NULL;
2140 bool drained = false;
2142 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
2144 if (unlikely(!(*did_some_progress)))
2147 /* After successful reclaim, reconsider all zones for allocation */
2149 zlc_clear_zones_full(zonelist);
2152 page = get_page_from_freelist(gfp_mask, nodemask, order,
2153 zonelist, high_zoneidx,
2154 alloc_flags, preferred_zone,
2158 * If an allocation failed after direct reclaim, it could be because
2159 * pages are pinned on the per-cpu lists. Drain them and try again
2161 if (!page && !drained) {
2171 * This is called in the allocator slow-path if the allocation request is of
2172 * sufficient urgency to ignore watermarks and take other desperate measures
2174 static inline struct page *
2175 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2176 struct zonelist *zonelist, enum zone_type high_zoneidx,
2177 nodemask_t *nodemask, struct zone *preferred_zone,
2183 page = get_page_from_freelist(gfp_mask, nodemask, order,
2184 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2185 preferred_zone, migratetype);
2187 if (!page && gfp_mask & __GFP_NOFAIL)
2188 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2189 } while (!page && (gfp_mask & __GFP_NOFAIL));
2195 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2196 enum zone_type high_zoneidx,
2197 enum zone_type classzone_idx)
2202 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2203 wakeup_kswapd(zone, order, classzone_idx);
2207 gfp_to_alloc_flags(gfp_t gfp_mask)
2209 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2210 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
2212 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2213 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2216 * The caller may dip into page reserves a bit more if the caller
2217 * cannot run direct reclaim, or if the caller has realtime scheduling
2218 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2219 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2221 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2225 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2226 * if it can't schedule.
2228 if (!(gfp_mask & __GFP_NOMEMALLOC))
2229 alloc_flags |= ALLOC_HARDER;
2231 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2232 * comment for __cpuset_node_allowed_softwall().
2234 alloc_flags &= ~ALLOC_CPUSET;
2235 } else if (unlikely(rt_task(current)) && !in_interrupt())
2236 alloc_flags |= ALLOC_HARDER;
2238 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2239 if (!in_interrupt() &&
2240 ((current->flags & PF_MEMALLOC) ||
2241 unlikely(test_thread_flag(TIF_MEMDIE))))
2242 alloc_flags |= ALLOC_NO_WATERMARKS;
2248 static inline struct page *
2249 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2250 struct zonelist *zonelist, enum zone_type high_zoneidx,
2251 nodemask_t *nodemask, struct zone *preferred_zone,
2254 const gfp_t wait = gfp_mask & __GFP_WAIT;
2255 struct page *page = NULL;
2257 unsigned long pages_reclaimed = 0;
2258 unsigned long did_some_progress;
2259 bool sync_migration = false;
2260 bool deferred_compaction = false;
2263 * In the slowpath, we sanity check order to avoid ever trying to
2264 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2265 * be using allocators in order of preference for an area that is
2268 if (order >= MAX_ORDER) {
2269 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2274 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2275 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2276 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2277 * using a larger set of nodes after it has established that the
2278 * allowed per node queues are empty and that nodes are
2281 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2285 if (!(gfp_mask & __GFP_NO_KSWAPD))
2286 wake_all_kswapd(order, zonelist, high_zoneidx,
2287 zone_idx(preferred_zone));
2290 * OK, we're below the kswapd watermark and have kicked background
2291 * reclaim. Now things get more complex, so set up alloc_flags according
2292 * to how we want to proceed.
2294 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2297 * Find the true preferred zone if the allocation is unconstrained by
2300 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
2301 first_zones_zonelist(zonelist, high_zoneidx, NULL,
2305 /* This is the last chance, in general, before the goto nopage. */
2306 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2307 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2308 preferred_zone, migratetype);
2312 /* Allocate without watermarks if the context allows */
2313 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2314 page = __alloc_pages_high_priority(gfp_mask, order,
2315 zonelist, high_zoneidx, nodemask,
2316 preferred_zone, migratetype);
2321 /* Atomic allocations - we can't balance anything */
2325 /* Avoid recursion of direct reclaim */
2326 if (current->flags & PF_MEMALLOC)
2329 /* Avoid allocations with no watermarks from looping endlessly */
2330 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2334 * Try direct compaction. The first pass is asynchronous. Subsequent
2335 * attempts after direct reclaim are synchronous
2337 page = __alloc_pages_direct_compact(gfp_mask, order,
2338 zonelist, high_zoneidx,
2340 alloc_flags, preferred_zone,
2341 migratetype, sync_migration,
2342 &deferred_compaction,
2343 &did_some_progress);
2346 sync_migration = true;
2349 * If compaction is deferred for high-order allocations, it is because
2350 * sync compaction recently failed. In this is the case and the caller
2351 * has requested the system not be heavily disrupted, fail the
2352 * allocation now instead of entering direct reclaim
2354 if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
2357 /* Try direct reclaim and then allocating */
2358 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2359 zonelist, high_zoneidx,
2361 alloc_flags, preferred_zone,
2362 migratetype, &did_some_progress);
2367 * If we failed to make any progress reclaiming, then we are
2368 * running out of options and have to consider going OOM
2370 if (!did_some_progress) {
2371 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2372 if (oom_killer_disabled)
2374 page = __alloc_pages_may_oom(gfp_mask, order,
2375 zonelist, high_zoneidx,
2376 nodemask, preferred_zone,
2381 if (!(gfp_mask & __GFP_NOFAIL)) {
2383 * The oom killer is not called for high-order
2384 * allocations that may fail, so if no progress
2385 * is being made, there are no other options and
2386 * retrying is unlikely to help.
2388 if (order > PAGE_ALLOC_COSTLY_ORDER)
2391 * The oom killer is not called for lowmem
2392 * allocations to prevent needlessly killing
2395 if (high_zoneidx < ZONE_NORMAL)
2403 /* Check if we should retry the allocation */
2404 pages_reclaimed += did_some_progress;
2405 if (should_alloc_retry(gfp_mask, order, did_some_progress,
2407 /* Wait for some write requests to complete then retry */
2408 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2412 * High-order allocations do not necessarily loop after
2413 * direct reclaim and reclaim/compaction depends on compaction
2414 * being called after reclaim so call directly if necessary
2416 page = __alloc_pages_direct_compact(gfp_mask, order,
2417 zonelist, high_zoneidx,
2419 alloc_flags, preferred_zone,
2420 migratetype, sync_migration,
2421 &deferred_compaction,
2422 &did_some_progress);
2428 warn_alloc_failed(gfp_mask, order, NULL);
2431 if (kmemcheck_enabled)
2432 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2438 * This is the 'heart' of the zoned buddy allocator.
2441 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2442 struct zonelist *zonelist, nodemask_t *nodemask)
2444 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2445 struct zone *preferred_zone;
2446 struct page *page = NULL;
2447 int migratetype = allocflags_to_migratetype(gfp_mask);
2448 unsigned int cpuset_mems_cookie;
2450 gfp_mask &= gfp_allowed_mask;
2452 lockdep_trace_alloc(gfp_mask);
2454 might_sleep_if(gfp_mask & __GFP_WAIT);
2456 if (should_fail_alloc_page(gfp_mask, order))
2460 * Check the zones suitable for the gfp_mask contain at least one
2461 * valid zone. It's possible to have an empty zonelist as a result
2462 * of GFP_THISNODE and a memoryless node
2464 if (unlikely(!zonelist->_zonerefs->zone))
2468 cpuset_mems_cookie = get_mems_allowed();
2470 /* The preferred zone is used for statistics later */
2471 first_zones_zonelist(zonelist, high_zoneidx,
2472 nodemask ? : &cpuset_current_mems_allowed,
2474 if (!preferred_zone)
2477 /* First allocation attempt */
2478 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2479 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
2480 preferred_zone, migratetype);
2481 if (unlikely(!page))
2482 page = __alloc_pages_slowpath(gfp_mask, order,
2483 zonelist, high_zoneidx, nodemask,
2484 preferred_zone, migratetype);
2486 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2490 * When updating a task's mems_allowed, it is possible to race with
2491 * parallel threads in such a way that an allocation can fail while
2492 * the mask is being updated. If a page allocation is about to fail,
2493 * check if the cpuset changed during allocation and if so, retry.
2495 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
2500 EXPORT_SYMBOL(__alloc_pages_nodemask);
2503 * Common helper functions.
2505 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2510 * __get_free_pages() returns a 32-bit address, which cannot represent
2513 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2515 page = alloc_pages(gfp_mask, order);
2518 return (unsigned long) page_address(page);
2520 EXPORT_SYMBOL(__get_free_pages);
2522 unsigned long get_zeroed_page(gfp_t gfp_mask)
2524 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2526 EXPORT_SYMBOL(get_zeroed_page);
2528 void __free_pages(struct page *page, unsigned int order)
2530 if (put_page_testzero(page)) {
2532 free_hot_cold_page(page, 0);
2534 __free_pages_ok(page, order);
2538 EXPORT_SYMBOL(__free_pages);
2540 void free_pages(unsigned long addr, unsigned int order)
2543 VM_BUG_ON(!virt_addr_valid((void *)addr));
2544 __free_pages(virt_to_page((void *)addr), order);
2548 EXPORT_SYMBOL(free_pages);
2550 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2553 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2554 unsigned long used = addr + PAGE_ALIGN(size);
2556 split_page(virt_to_page((void *)addr), order);
2557 while (used < alloc_end) {
2562 return (void *)addr;
2566 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2567 * @size: the number of bytes to allocate
2568 * @gfp_mask: GFP flags for the allocation
2570 * This function is similar to alloc_pages(), except that it allocates the
2571 * minimum number of pages to satisfy the request. alloc_pages() can only
2572 * allocate memory in power-of-two pages.
2574 * This function is also limited by MAX_ORDER.
2576 * Memory allocated by this function must be released by free_pages_exact().
2578 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2580 unsigned int order = get_order(size);
2583 addr = __get_free_pages(gfp_mask, order);
2584 return make_alloc_exact(addr, order, size);
2586 EXPORT_SYMBOL(alloc_pages_exact);
2589 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2591 * @nid: the preferred node ID where memory should be allocated
2592 * @size: the number of bytes to allocate
2593 * @gfp_mask: GFP flags for the allocation
2595 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2597 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2600 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2602 unsigned order = get_order(size);
2603 struct page *p = alloc_pages_node(nid, gfp_mask, order);
2606 return make_alloc_exact((unsigned long)page_address(p), order, size);
2608 EXPORT_SYMBOL(alloc_pages_exact_nid);
2611 * free_pages_exact - release memory allocated via alloc_pages_exact()
2612 * @virt: the value returned by alloc_pages_exact.
2613 * @size: size of allocation, same value as passed to alloc_pages_exact().
2615 * Release the memory allocated by a previous call to alloc_pages_exact.
2617 void free_pages_exact(void *virt, size_t size)
2619 unsigned long addr = (unsigned long)virt;
2620 unsigned long end = addr + PAGE_ALIGN(size);
2622 while (addr < end) {
2627 EXPORT_SYMBOL(free_pages_exact);
2629 static unsigned int nr_free_zone_pages(int offset)
2634 /* Just pick one node, since fallback list is circular */
2635 unsigned int sum = 0;
2637 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2639 for_each_zone_zonelist(zone, z, zonelist, offset) {
2640 unsigned long size = zone->present_pages;
2641 unsigned long high = high_wmark_pages(zone);
2650 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2652 unsigned int nr_free_buffer_pages(void)
2654 return nr_free_zone_pages(gfp_zone(GFP_USER));
2656 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2659 * Amount of free RAM allocatable within all zones
2661 unsigned int nr_free_pagecache_pages(void)
2663 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2666 static inline void show_node(struct zone *zone)
2669 printk("Node %d ", zone_to_nid(zone));
2672 void si_meminfo(struct sysinfo *val)
2674 val->totalram = totalram_pages;
2676 val->freeram = global_page_state(NR_FREE_PAGES);
2677 val->bufferram = nr_blockdev_pages();
2678 val->totalhigh = totalhigh_pages;
2679 val->freehigh = nr_free_highpages();
2680 val->mem_unit = PAGE_SIZE;
2683 EXPORT_SYMBOL(si_meminfo);
2686 void si_meminfo_node(struct sysinfo *val, int nid)
2688 pg_data_t *pgdat = NODE_DATA(nid);
2690 val->totalram = pgdat->node_present_pages;
2691 val->freeram = node_page_state(nid, NR_FREE_PAGES);
2692 #ifdef CONFIG_HIGHMEM
2693 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2694 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2700 val->mem_unit = PAGE_SIZE;
2705 * Determine whether the node should be displayed or not, depending on whether
2706 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2708 bool skip_free_areas_node(unsigned int flags, int nid)
2711 unsigned int cpuset_mems_cookie;
2713 if (!(flags & SHOW_MEM_FILTER_NODES))
2717 cpuset_mems_cookie = get_mems_allowed();
2718 ret = !node_isset(nid, cpuset_current_mems_allowed);
2719 } while (!put_mems_allowed(cpuset_mems_cookie));
2724 #define K(x) ((x) << (PAGE_SHIFT-10))
2727 * Show free area list (used inside shift_scroll-lock stuff)
2728 * We also calculate the percentage fragmentation. We do this by counting the
2729 * memory on each free list with the exception of the first item on the list.
2730 * Suppresses nodes that are not allowed by current's cpuset if
2731 * SHOW_MEM_FILTER_NODES is passed.
2733 void show_free_areas(unsigned int filter)
2738 for_each_populated_zone(zone) {
2739 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2742 printk("%s per-cpu:\n", zone->name);
2744 for_each_online_cpu(cpu) {
2745 struct per_cpu_pageset *pageset;
2747 pageset = per_cpu_ptr(zone->pageset, cpu);
2749 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2750 cpu, pageset->pcp.high,
2751 pageset->pcp.batch, pageset->pcp.count);
2755 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2756 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2758 " dirty:%lu writeback:%lu unstable:%lu\n"
2759 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2760 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2761 global_page_state(NR_ACTIVE_ANON),
2762 global_page_state(NR_INACTIVE_ANON),
2763 global_page_state(NR_ISOLATED_ANON),
2764 global_page_state(NR_ACTIVE_FILE),
2765 global_page_state(NR_INACTIVE_FILE),
2766 global_page_state(NR_ISOLATED_FILE),
2767 global_page_state(NR_UNEVICTABLE),
2768 global_page_state(NR_FILE_DIRTY),
2769 global_page_state(NR_WRITEBACK),
2770 global_page_state(NR_UNSTABLE_NFS),
2771 global_page_state(NR_FREE_PAGES),
2772 global_page_state(NR_SLAB_RECLAIMABLE),
2773 global_page_state(NR_SLAB_UNRECLAIMABLE),
2774 global_page_state(NR_FILE_MAPPED),
2775 global_page_state(NR_SHMEM),
2776 global_page_state(NR_PAGETABLE),
2777 global_page_state(NR_BOUNCE));
2779 for_each_populated_zone(zone) {
2782 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2790 " active_anon:%lukB"
2791 " inactive_anon:%lukB"
2792 " active_file:%lukB"
2793 " inactive_file:%lukB"
2794 " unevictable:%lukB"
2795 " isolated(anon):%lukB"
2796 " isolated(file):%lukB"
2803 " slab_reclaimable:%lukB"
2804 " slab_unreclaimable:%lukB"
2805 " kernel_stack:%lukB"
2809 " writeback_tmp:%lukB"
2810 " pages_scanned:%lu"
2811 " all_unreclaimable? %s"
2814 K(zone_page_state(zone, NR_FREE_PAGES)),
2815 K(min_wmark_pages(zone)),
2816 K(low_wmark_pages(zone)),
2817 K(high_wmark_pages(zone)),
2818 K(zone_page_state(zone, NR_ACTIVE_ANON)),
2819 K(zone_page_state(zone, NR_INACTIVE_ANON)),
2820 K(zone_page_state(zone, NR_ACTIVE_FILE)),
2821 K(zone_page_state(zone, NR_INACTIVE_FILE)),
2822 K(zone_page_state(zone, NR_UNEVICTABLE)),
2823 K(zone_page_state(zone, NR_ISOLATED_ANON)),
2824 K(zone_page_state(zone, NR_ISOLATED_FILE)),
2825 K(zone->present_pages),
2826 K(zone_page_state(zone, NR_MLOCK)),
2827 K(zone_page_state(zone, NR_FILE_DIRTY)),
2828 K(zone_page_state(zone, NR_WRITEBACK)),
2829 K(zone_page_state(zone, NR_FILE_MAPPED)),
2830 K(zone_page_state(zone, NR_SHMEM)),
2831 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
2832 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2833 zone_page_state(zone, NR_KERNEL_STACK) *
2835 K(zone_page_state(zone, NR_PAGETABLE)),
2836 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
2837 K(zone_page_state(zone, NR_BOUNCE)),
2838 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
2839 zone->pages_scanned,
2840 (zone->all_unreclaimable ? "yes" : "no")
2842 printk("lowmem_reserve[]:");
2843 for (i = 0; i < MAX_NR_ZONES; i++)
2844 printk(" %lu", zone->lowmem_reserve[i]);
2848 for_each_populated_zone(zone) {
2849 unsigned long nr[MAX_ORDER], flags, order, total = 0;
2851 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2854 printk("%s: ", zone->name);
2856 spin_lock_irqsave(&zone->lock, flags);
2857 for (order = 0; order < MAX_ORDER; order++) {
2858 nr[order] = zone->free_area[order].nr_free;
2859 total += nr[order] << order;
2861 spin_unlock_irqrestore(&zone->lock, flags);
2862 for (order = 0; order < MAX_ORDER; order++)
2863 printk("%lu*%lukB ", nr[order], K(1UL) << order);
2864 printk("= %lukB\n", K(total));
2867 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
2869 show_swap_cache_info();
2872 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
2874 zoneref->zone = zone;
2875 zoneref->zone_idx = zone_idx(zone);
2879 * Builds allocation fallback zone lists.
2881 * Add all populated zones of a node to the zonelist.
2883 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
2884 int nr_zones, enum zone_type zone_type)
2888 BUG_ON(zone_type >= MAX_NR_ZONES);
2893 zone = pgdat->node_zones + zone_type;
2894 if (populated_zone(zone)) {
2895 zoneref_set_zone(zone,
2896 &zonelist->_zonerefs[nr_zones++]);
2897 check_highest_zone(zone_type);
2900 } while (zone_type);
2907 * 0 = automatic detection of better ordering.
2908 * 1 = order by ([node] distance, -zonetype)
2909 * 2 = order by (-zonetype, [node] distance)
2911 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2912 * the same zonelist. So only NUMA can configure this param.
2914 #define ZONELIST_ORDER_DEFAULT 0
2915 #define ZONELIST_ORDER_NODE 1
2916 #define ZONELIST_ORDER_ZONE 2
2918 /* zonelist order in the kernel.
2919 * set_zonelist_order() will set this to NODE or ZONE.
2921 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
2922 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
2926 /* The value user specified ....changed by config */
2927 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2928 /* string for sysctl */
2929 #define NUMA_ZONELIST_ORDER_LEN 16
2930 char numa_zonelist_order[16] = "default";
2933 * interface for configure zonelist ordering.
2934 * command line option "numa_zonelist_order"
2935 * = "[dD]efault - default, automatic configuration.
2936 * = "[nN]ode - order by node locality, then by zone within node
2937 * = "[zZ]one - order by zone, then by locality within zone
2940 static int __parse_numa_zonelist_order(char *s)
2942 if (*s == 'd' || *s == 'D') {
2943 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2944 } else if (*s == 'n' || *s == 'N') {
2945 user_zonelist_order = ZONELIST_ORDER_NODE;
2946 } else if (*s == 'z' || *s == 'Z') {
2947 user_zonelist_order = ZONELIST_ORDER_ZONE;
2950 "Ignoring invalid numa_zonelist_order value: "
2957 static __init int setup_numa_zonelist_order(char *s)
2964 ret = __parse_numa_zonelist_order(s);
2966 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
2970 early_param("numa_zonelist_order", setup_numa_zonelist_order);
2973 * sysctl handler for numa_zonelist_order
2975 int numa_zonelist_order_handler(ctl_table *table, int write,
2976 void __user *buffer, size_t *length,
2979 char saved_string[NUMA_ZONELIST_ORDER_LEN];
2981 static DEFINE_MUTEX(zl_order_mutex);
2983 mutex_lock(&zl_order_mutex);
2985 strcpy(saved_string, (char*)table->data);
2986 ret = proc_dostring(table, write, buffer, length, ppos);
2990 int oldval = user_zonelist_order;
2991 if (__parse_numa_zonelist_order((char*)table->data)) {
2993 * bogus value. restore saved string
2995 strncpy((char*)table->data, saved_string,
2996 NUMA_ZONELIST_ORDER_LEN);
2997 user_zonelist_order = oldval;
2998 } else if (oldval != user_zonelist_order) {
2999 mutex_lock(&zonelists_mutex);
3000 build_all_zonelists(NULL);
3001 mutex_unlock(&zonelists_mutex);
3005 mutex_unlock(&zl_order_mutex);
3010 #define MAX_NODE_LOAD (nr_online_nodes)
3011 static int node_load[MAX_NUMNODES];
3014 * find_next_best_node - find the next node that should appear in a given node's fallback list
3015 * @node: node whose fallback list we're appending
3016 * @used_node_mask: nodemask_t of already used nodes
3018 * We use a number of factors to determine which is the next node that should
3019 * appear on a given node's fallback list. The node should not have appeared
3020 * already in @node's fallback list, and it should be the next closest node
3021 * according to the distance array (which contains arbitrary distance values
3022 * from each node to each node in the system), and should also prefer nodes
3023 * with no CPUs, since presumably they'll have very little allocation pressure
3024 * on them otherwise.
3025 * It returns -1 if no node is found.
3027 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3030 int min_val = INT_MAX;
3032 const struct cpumask *tmp = cpumask_of_node(0);
3034 /* Use the local node if we haven't already */
3035 if (!node_isset(node, *used_node_mask)) {
3036 node_set(node, *used_node_mask);
3040 for_each_node_state(n, N_HIGH_MEMORY) {
3042 /* Don't want a node to appear more than once */
3043 if (node_isset(n, *used_node_mask))
3046 /* Use the distance array to find the distance */
3047 val = node_distance(node, n);
3049 /* Penalize nodes under us ("prefer the next node") */
3052 /* Give preference to headless and unused nodes */
3053 tmp = cpumask_of_node(n);
3054 if (!cpumask_empty(tmp))
3055 val += PENALTY_FOR_NODE_WITH_CPUS;
3057 /* Slight preference for less loaded node */
3058 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3059 val += node_load[n];
3061 if (val < min_val) {
3068 node_set(best_node, *used_node_mask);
3075 * Build zonelists ordered by node and zones within node.
3076 * This results in maximum locality--normal zone overflows into local
3077 * DMA zone, if any--but risks exhausting DMA zone.
3079 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3082 struct zonelist *zonelist;
3084 zonelist = &pgdat->node_zonelists[0];
3085 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3087 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3089 zonelist->_zonerefs[j].zone = NULL;
3090 zonelist->_zonerefs[j].zone_idx = 0;
3094 * Build gfp_thisnode zonelists
3096 static void build_thisnode_zonelists(pg_data_t *pgdat)
3099 struct zonelist *zonelist;
3101 zonelist = &pgdat->node_zonelists[1];
3102 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3103 zonelist->_zonerefs[j].zone = NULL;
3104 zonelist->_zonerefs[j].zone_idx = 0;
3108 * Build zonelists ordered by zone and nodes within zones.
3109 * This results in conserving DMA zone[s] until all Normal memory is
3110 * exhausted, but results in overflowing to remote node while memory
3111 * may still exist in local DMA zone.
3113 static int node_order[MAX_NUMNODES];
3115 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3118 int zone_type; /* needs to be signed */
3120 struct zonelist *zonelist;
3122 zonelist = &pgdat->node_zonelists[0];
3124 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3125 for (j = 0; j < nr_nodes; j++) {
3126 node = node_order[j];
3127 z = &NODE_DATA(node)->node_zones[zone_type];
3128 if (populated_zone(z)) {
3130 &zonelist->_zonerefs[pos++]);
3131 check_highest_zone(zone_type);
3135 zonelist->_zonerefs[pos].zone = NULL;
3136 zonelist->_zonerefs[pos].zone_idx = 0;
3139 static int default_zonelist_order(void)
3142 unsigned long low_kmem_size,total_size;
3146 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3147 * If they are really small and used heavily, the system can fall
3148 * into OOM very easily.
3149 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3151 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3154 for_each_online_node(nid) {
3155 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3156 z = &NODE_DATA(nid)->node_zones[zone_type];
3157 if (populated_zone(z)) {
3158 if (zone_type < ZONE_NORMAL)
3159 low_kmem_size += z->present_pages;
3160 total_size += z->present_pages;
3161 } else if (zone_type == ZONE_NORMAL) {
3163 * If any node has only lowmem, then node order
3164 * is preferred to allow kernel allocations
3165 * locally; otherwise, they can easily infringe
3166 * on other nodes when there is an abundance of
3167 * lowmem available to allocate from.
3169 return ZONELIST_ORDER_NODE;
3173 if (!low_kmem_size || /* there are no DMA area. */
3174 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
3175 return ZONELIST_ORDER_NODE;
3177 * look into each node's config.
3178 * If there is a node whose DMA/DMA32 memory is very big area on
3179 * local memory, NODE_ORDER may be suitable.
3181 average_size = total_size /
3182 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
3183 for_each_online_node(nid) {
3186 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3187 z = &NODE_DATA(nid)->node_zones[zone_type];
3188 if (populated_zone(z)) {
3189 if (zone_type < ZONE_NORMAL)
3190 low_kmem_size += z->present_pages;
3191 total_size += z->present_pages;
3194 if (low_kmem_size &&
3195 total_size > average_size && /* ignore small node */
3196 low_kmem_size > total_size * 70/100)
3197 return ZONELIST_ORDER_NODE;
3199 return ZONELIST_ORDER_ZONE;
3202 static void set_zonelist_order(void)
3204 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3205 current_zonelist_order = default_zonelist_order();
3207 current_zonelist_order = user_zonelist_order;
3210 static void build_zonelists(pg_data_t *pgdat)
3214 nodemask_t used_mask;
3215 int local_node, prev_node;
3216 struct zonelist *zonelist;
3217 int order = current_zonelist_order;
3219 /* initialize zonelists */
3220 for (i = 0; i < MAX_ZONELISTS; i++) {
3221 zonelist = pgdat->node_zonelists + i;
3222 zonelist->_zonerefs[0].zone = NULL;
3223 zonelist->_zonerefs[0].zone_idx = 0;
3226 /* NUMA-aware ordering of nodes */
3227 local_node = pgdat->node_id;
3228 load = nr_online_nodes;
3229 prev_node = local_node;
3230 nodes_clear(used_mask);
3232 memset(node_order, 0, sizeof(node_order));
3235 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3236 int distance = node_distance(local_node, node);
3239 * If another node is sufficiently far away then it is better
3240 * to reclaim pages in a zone before going off node.
3242 if (distance > RECLAIM_DISTANCE)
3243 zone_reclaim_mode = 1;
3246 * We don't want to pressure a particular node.
3247 * So adding penalty to the first node in same
3248 * distance group to make it round-robin.
3250 if (distance != node_distance(local_node, prev_node))
3251 node_load[node] = load;
3255 if (order == ZONELIST_ORDER_NODE)
3256 build_zonelists_in_node_order(pgdat, node);
3258 node_order[j++] = node; /* remember order */
3261 if (order == ZONELIST_ORDER_ZONE) {
3262 /* calculate node order -- i.e., DMA last! */
3263 build_zonelists_in_zone_order(pgdat, j);
3266 build_thisnode_zonelists(pgdat);
3269 /* Construct the zonelist performance cache - see further mmzone.h */
3270 static void build_zonelist_cache(pg_data_t *pgdat)
3272 struct zonelist *zonelist;
3273 struct zonelist_cache *zlc;
3276 zonelist = &pgdat->node_zonelists[0];
3277 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3278 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3279 for (z = zonelist->_zonerefs; z->zone; z++)
3280 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3283 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3285 * Return node id of node used for "local" allocations.
3286 * I.e., first node id of first zone in arg node's generic zonelist.
3287 * Used for initializing percpu 'numa_mem', which is used primarily
3288 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3290 int local_memory_node(int node)
3294 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3295 gfp_zone(GFP_KERNEL),
3302 #else /* CONFIG_NUMA */
3304 static void set_zonelist_order(void)
3306 current_zonelist_order = ZONELIST_ORDER_ZONE;
3309 static void build_zonelists(pg_data_t *pgdat)
3311 int node, local_node;
3313 struct zonelist *zonelist;
3315 local_node = pgdat->node_id;
3317 zonelist = &pgdat->node_zonelists[0];
3318 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3321 * Now we build the zonelist so that it contains the zones
3322 * of all the other nodes.
3323 * We don't want to pressure a particular node, so when
3324 * building the zones for node N, we make sure that the
3325 * zones coming right after the local ones are those from
3326 * node N+1 (modulo N)
3328 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3329 if (!node_online(node))
3331 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3334 for (node = 0; node < local_node; node++) {
3335 if (!node_online(node))
3337 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3341 zonelist->_zonerefs[j].zone = NULL;
3342 zonelist->_zonerefs[j].zone_idx = 0;
3345 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3346 static void build_zonelist_cache(pg_data_t *pgdat)
3348 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3351 #endif /* CONFIG_NUMA */
3354 * Boot pageset table. One per cpu which is going to be used for all
3355 * zones and all nodes. The parameters will be set in such a way
3356 * that an item put on a list will immediately be handed over to
3357 * the buddy list. This is safe since pageset manipulation is done
3358 * with interrupts disabled.
3360 * The boot_pagesets must be kept even after bootup is complete for
3361 * unused processors and/or zones. They do play a role for bootstrapping
3362 * hotplugged processors.
3364 * zoneinfo_show() and maybe other functions do
3365 * not check if the processor is online before following the pageset pointer.
3366 * Other parts of the kernel may not check if the zone is available.
3368 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3369 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3370 static void setup_zone_pageset(struct zone *zone);
3373 * Global mutex to protect against size modification of zonelists
3374 * as well as to serialize pageset setup for the new populated zone.
3376 DEFINE_MUTEX(zonelists_mutex);
3378 /* return values int ....just for stop_machine() */
3379 static __init_refok int __build_all_zonelists(void *data)
3385 memset(node_load, 0, sizeof(node_load));
3387 for_each_online_node(nid) {
3388 pg_data_t *pgdat = NODE_DATA(nid);
3390 build_zonelists(pgdat);
3391 build_zonelist_cache(pgdat);
3395 * Initialize the boot_pagesets that are going to be used
3396 * for bootstrapping processors. The real pagesets for
3397 * each zone will be allocated later when the per cpu
3398 * allocator is available.
3400 * boot_pagesets are used also for bootstrapping offline
3401 * cpus if the system is already booted because the pagesets
3402 * are needed to initialize allocators on a specific cpu too.
3403 * F.e. the percpu allocator needs the page allocator which
3404 * needs the percpu allocator in order to allocate its pagesets
3405 * (a chicken-egg dilemma).
3407 for_each_possible_cpu(cpu) {
3408 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3410 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3412 * We now know the "local memory node" for each node--
3413 * i.e., the node of the first zone in the generic zonelist.
3414 * Set up numa_mem percpu variable for on-line cpus. During
3415 * boot, only the boot cpu should be on-line; we'll init the
3416 * secondary cpus' numa_mem as they come on-line. During
3417 * node/memory hotplug, we'll fixup all on-line cpus.
3419 if (cpu_online(cpu))
3420 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3428 * Called with zonelists_mutex held always
3429 * unless system_state == SYSTEM_BOOTING.
3431 void __ref build_all_zonelists(void *data)
3433 set_zonelist_order();
3435 if (system_state == SYSTEM_BOOTING) {
3436 __build_all_zonelists(NULL);
3437 mminit_verify_zonelist();
3438 cpuset_init_current_mems_allowed();
3440 /* we have to stop all cpus to guarantee there is no user
3442 #ifdef CONFIG_MEMORY_HOTPLUG
3444 setup_zone_pageset((struct zone *)data);
3446 stop_machine(__build_all_zonelists, NULL, NULL);
3447 /* cpuset refresh routine should be here */
3449 vm_total_pages = nr_free_pagecache_pages();
3451 * Disable grouping by mobility if the number of pages in the
3452 * system is too low to allow the mechanism to work. It would be
3453 * more accurate, but expensive to check per-zone. This check is
3454 * made on memory-hotadd so a system can start with mobility
3455 * disabled and enable it later
3457 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3458 page_group_by_mobility_disabled = 1;
3460 page_group_by_mobility_disabled = 0;
3462 printk("Built %i zonelists in %s order, mobility grouping %s. "
3463 "Total pages: %ld\n",
3465 zonelist_order_name[current_zonelist_order],
3466 page_group_by_mobility_disabled ? "off" : "on",
3469 printk("Policy zone: %s\n", zone_names[policy_zone]);
3474 * Helper functions to size the waitqueue hash table.
3475 * Essentially these want to choose hash table sizes sufficiently
3476 * large so that collisions trying to wait on pages are rare.
3477 * But in fact, the number of active page waitqueues on typical
3478 * systems is ridiculously low, less than 200. So this is even
3479 * conservative, even though it seems large.
3481 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3482 * waitqueues, i.e. the size of the waitq table given the number of pages.
3484 #define PAGES_PER_WAITQUEUE 256
3486 #ifndef CONFIG_MEMORY_HOTPLUG
3487 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3489 unsigned long size = 1;
3491 pages /= PAGES_PER_WAITQUEUE;
3493 while (size < pages)
3497 * Once we have dozens or even hundreds of threads sleeping
3498 * on IO we've got bigger problems than wait queue collision.
3499 * Limit the size of the wait table to a reasonable size.
3501 size = min(size, 4096UL);
3503 return max(size, 4UL);
3507 * A zone's size might be changed by hot-add, so it is not possible to determine
3508 * a suitable size for its wait_table. So we use the maximum size now.
3510 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3512 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3513 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3514 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3516 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3517 * or more by the traditional way. (See above). It equals:
3519 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3520 * ia64(16K page size) : = ( 8G + 4M)byte.
3521 * powerpc (64K page size) : = (32G +16M)byte.
3523 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3530 * This is an integer logarithm so that shifts can be used later
3531 * to extract the more random high bits from the multiplicative
3532 * hash function before the remainder is taken.
3534 static inline unsigned long wait_table_bits(unsigned long size)
3539 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3542 * Check if a pageblock contains reserved pages
3544 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3548 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3549 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3556 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3557 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3558 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3559 * higher will lead to a bigger reserve which will get freed as contiguous
3560 * blocks as reclaim kicks in
3562 static void setup_zone_migrate_reserve(struct zone *zone)
3564 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3566 unsigned long block_migratetype;
3570 * Get the start pfn, end pfn and the number of blocks to reserve
3571 * We have to be careful to be aligned to pageblock_nr_pages to
3572 * make sure that we always check pfn_valid for the first page in
3575 start_pfn = zone->zone_start_pfn;
3576 end_pfn = start_pfn + zone->spanned_pages;
3577 start_pfn = roundup(start_pfn, pageblock_nr_pages);
3578 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3582 * Reserve blocks are generally in place to help high-order atomic
3583 * allocations that are short-lived. A min_free_kbytes value that
3584 * would result in more than 2 reserve blocks for atomic allocations
3585 * is assumed to be in place to help anti-fragmentation for the
3586 * future allocation of hugepages at runtime.
3588 reserve = min(2, reserve);
3590 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3591 if (!pfn_valid(pfn))
3593 page = pfn_to_page(pfn);
3595 /* Watch out for overlapping nodes */
3596 if (page_to_nid(page) != zone_to_nid(zone))
3599 block_migratetype = get_pageblock_migratetype(page);
3601 /* Only test what is necessary when the reserves are not met */
3604 * Blocks with reserved pages will never free, skip
3607 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
3608 if (pageblock_is_reserved(pfn, block_end_pfn))
3611 /* If this block is reserved, account for it */
3612 if (block_migratetype == MIGRATE_RESERVE) {
3617 /* Suitable for reserving if this block is movable */
3618 if (block_migratetype == MIGRATE_MOVABLE) {
3619 set_pageblock_migratetype(page,
3621 move_freepages_block(zone, page,
3629 * If the reserve is met and this is a previous reserved block,
3632 if (block_migratetype == MIGRATE_RESERVE) {
3633 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3634 move_freepages_block(zone, page, MIGRATE_MOVABLE);
3640 * Initially all pages are reserved - free ones are freed
3641 * up by free_all_bootmem() once the early boot process is
3642 * done. Non-atomic initialization, single-pass.
3644 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
3645 unsigned long start_pfn, enum memmap_context context)
3648 unsigned long end_pfn = start_pfn + size;
3652 if (highest_memmap_pfn < end_pfn - 1)
3653 highest_memmap_pfn = end_pfn - 1;
3655 z = &NODE_DATA(nid)->node_zones[zone];
3656 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3658 * There can be holes in boot-time mem_map[]s
3659 * handed to this function. They do not
3660 * exist on hotplugged memory.
3662 if (context == MEMMAP_EARLY) {
3663 if (!early_pfn_valid(pfn))
3665 if (!early_pfn_in_nid(pfn, nid))
3668 page = pfn_to_page(pfn);
3669 set_page_links(page, zone, nid, pfn);
3670 mminit_verify_page_links(page, zone, nid, pfn);
3671 init_page_count(page);
3672 reset_page_mapcount(page);
3673 SetPageReserved(page);
3675 * Mark the block movable so that blocks are reserved for
3676 * movable at startup. This will force kernel allocations
3677 * to reserve their blocks rather than leaking throughout
3678 * the address space during boot when many long-lived
3679 * kernel allocations are made. Later some blocks near
3680 * the start are marked MIGRATE_RESERVE by
3681 * setup_zone_migrate_reserve()
3683 * bitmap is created for zone's valid pfn range. but memmap
3684 * can be created for invalid pages (for alignment)
3685 * check here not to call set_pageblock_migratetype() against
3688 if ((z->zone_start_pfn <= pfn)
3689 && (pfn < z->zone_start_pfn + z->spanned_pages)
3690 && !(pfn & (pageblock_nr_pages - 1)))
3691 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3693 INIT_LIST_HEAD(&page->lru);
3694 #ifdef WANT_PAGE_VIRTUAL
3695 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3696 if (!is_highmem_idx(zone))
3697 set_page_address(page, __va(pfn << PAGE_SHIFT));
3702 static void __meminit zone_init_free_lists(struct zone *zone)
3705 for_each_migratetype_order(order, t) {
3706 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
3707 zone->free_area[order].nr_free = 0;
3711 #ifndef __HAVE_ARCH_MEMMAP_INIT
3712 #define memmap_init(size, nid, zone, start_pfn) \
3713 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3716 static int zone_batchsize(struct zone *zone)
3722 * The per-cpu-pages pools are set to around 1000th of the
3723 * size of the zone. But no more than 1/2 of a meg.
3725 * OK, so we don't know how big the cache is. So guess.
3727 batch = zone->present_pages / 1024;
3728 if (batch * PAGE_SIZE > 512 * 1024)
3729 batch = (512 * 1024) / PAGE_SIZE;
3730 batch /= 4; /* We effectively *= 4 below */
3735 * Clamp the batch to a 2^n - 1 value. Having a power
3736 * of 2 value was found to be more likely to have
3737 * suboptimal cache aliasing properties in some cases.
3739 * For example if 2 tasks are alternately allocating
3740 * batches of pages, one task can end up with a lot
3741 * of pages of one half of the possible page colors
3742 * and the other with pages of the other colors.
3744 batch = rounddown_pow_of_two(batch + batch/2) - 1;
3749 /* The deferral and batching of frees should be suppressed under NOMMU
3752 * The problem is that NOMMU needs to be able to allocate large chunks
3753 * of contiguous memory as there's no hardware page translation to
3754 * assemble apparent contiguous memory from discontiguous pages.
3756 * Queueing large contiguous runs of pages for batching, however,
3757 * causes the pages to actually be freed in smaller chunks. As there
3758 * can be a significant delay between the individual batches being
3759 * recycled, this leads to the once large chunks of space being
3760 * fragmented and becoming unavailable for high-order allocations.
3766 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3768 struct per_cpu_pages *pcp;
3771 memset(p, 0, sizeof(*p));
3775 pcp->high = 6 * batch;
3776 pcp->batch = max(1UL, 1 * batch);
3777 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
3778 INIT_LIST_HEAD(&pcp->lists[migratetype]);
3782 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3783 * to the value high for the pageset p.
3786 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
3789 struct per_cpu_pages *pcp;
3793 pcp->batch = max(1UL, high/4);
3794 if ((high/4) > (PAGE_SHIFT * 8))
3795 pcp->batch = PAGE_SHIFT * 8;
3798 static void setup_zone_pageset(struct zone *zone)
3802 zone->pageset = alloc_percpu(struct per_cpu_pageset);
3804 for_each_possible_cpu(cpu) {
3805 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
3807 setup_pageset(pcp, zone_batchsize(zone));
3809 if (percpu_pagelist_fraction)
3810 setup_pagelist_highmark(pcp,
3811 (zone->present_pages /
3812 percpu_pagelist_fraction));
3817 * Allocate per cpu pagesets and initialize them.
3818 * Before this call only boot pagesets were available.
3820 void __init setup_per_cpu_pageset(void)
3824 for_each_populated_zone(zone)
3825 setup_zone_pageset(zone);
3828 static noinline __init_refok
3829 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3832 struct pglist_data *pgdat = zone->zone_pgdat;
3836 * The per-page waitqueue mechanism uses hashed waitqueues
3839 zone->wait_table_hash_nr_entries =
3840 wait_table_hash_nr_entries(zone_size_pages);
3841 zone->wait_table_bits =
3842 wait_table_bits(zone->wait_table_hash_nr_entries);
3843 alloc_size = zone->wait_table_hash_nr_entries
3844 * sizeof(wait_queue_head_t);
3846 if (!slab_is_available()) {
3847 zone->wait_table = (wait_queue_head_t *)
3848 alloc_bootmem_node_nopanic(pgdat, alloc_size);
3851 * This case means that a zone whose size was 0 gets new memory
3852 * via memory hot-add.
3853 * But it may be the case that a new node was hot-added. In
3854 * this case vmalloc() will not be able to use this new node's
3855 * memory - this wait_table must be initialized to use this new
3856 * node itself as well.
3857 * To use this new node's memory, further consideration will be
3860 zone->wait_table = vmalloc(alloc_size);
3862 if (!zone->wait_table)
3865 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3866 init_waitqueue_head(zone->wait_table + i);
3871 static int __zone_pcp_update(void *data)
3873 struct zone *zone = data;
3875 unsigned long batch = zone_batchsize(zone), flags;
3877 for_each_possible_cpu(cpu) {
3878 struct per_cpu_pageset *pset;
3879 struct per_cpu_pages *pcp;
3881 pset = per_cpu_ptr(zone->pageset, cpu);
3884 local_irq_save(flags);
3885 free_pcppages_bulk(zone, pcp->count, pcp);
3886 setup_pageset(pset, batch);
3887 local_irq_restore(flags);
3892 void zone_pcp_update(struct zone *zone)
3894 stop_machine(__zone_pcp_update, zone, NULL);
3897 static __meminit void zone_pcp_init(struct zone *zone)
3900 * per cpu subsystem is not up at this point. The following code
3901 * relies on the ability of the linker to provide the
3902 * offset of a (static) per cpu variable into the per cpu area.
3904 zone->pageset = &boot_pageset;
3906 if (zone->present_pages)
3907 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
3908 zone->name, zone->present_pages,
3909 zone_batchsize(zone));
3912 __meminit int init_currently_empty_zone(struct zone *zone,
3913 unsigned long zone_start_pfn,
3915 enum memmap_context context)
3917 struct pglist_data *pgdat = zone->zone_pgdat;
3919 ret = zone_wait_table_init(zone, size);
3922 pgdat->nr_zones = zone_idx(zone) + 1;
3924 zone->zone_start_pfn = zone_start_pfn;
3926 mminit_dprintk(MMINIT_TRACE, "memmap_init",
3927 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3929 (unsigned long)zone_idx(zone),
3930 zone_start_pfn, (zone_start_pfn + size));
3932 zone_init_free_lists(zone);
3937 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3939 * Basic iterator support. Return the first range of PFNs for a node
3940 * Note: nid == MAX_NUMNODES returns first region regardless of node
3942 static int __meminit first_active_region_index_in_nid(int nid)
3946 for (i = 0; i < nr_nodemap_entries; i++)
3947 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3954 * Basic iterator support. Return the next active range of PFNs for a node
3955 * Note: nid == MAX_NUMNODES returns next region regardless of node
3957 static int __meminit next_active_region_index_in_nid(int index, int nid)
3959 for (index = index + 1; index < nr_nodemap_entries; index++)
3960 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3966 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3968 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3969 * Architectures may implement their own version but if add_active_range()
3970 * was used and there are no special requirements, this is a convenient
3973 int __meminit __early_pfn_to_nid(unsigned long pfn)
3977 for (i = 0; i < nr_nodemap_entries; i++) {
3978 unsigned long start_pfn = early_node_map[i].start_pfn;
3979 unsigned long end_pfn = early_node_map[i].end_pfn;
3981 if (start_pfn <= pfn && pfn < end_pfn)
3982 return early_node_map[i].nid;
3984 /* This is a memory hole */
3987 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3989 int __meminit early_pfn_to_nid(unsigned long pfn)
3993 nid = __early_pfn_to_nid(pfn);
3996 /* just returns 0 */
4000 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4001 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4005 nid = __early_pfn_to_nid(pfn);
4006 if (nid >= 0 && nid != node)
4012 /* Basic iterator support to walk early_node_map[] */
4013 #define for_each_active_range_index_in_nid(i, nid) \
4014 for (i = first_active_region_index_in_nid(nid); i != -1; \
4015 i = next_active_region_index_in_nid(i, nid))
4018 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4019 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4020 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
4022 * If an architecture guarantees that all ranges registered with
4023 * add_active_ranges() contain no holes and may be freed, this
4024 * this function may be used instead of calling free_bootmem() manually.
4026 void __init free_bootmem_with_active_regions(int nid,
4027 unsigned long max_low_pfn)
4031 for_each_active_range_index_in_nid(i, nid) {
4032 unsigned long size_pages = 0;
4033 unsigned long end_pfn = early_node_map[i].end_pfn;
4035 if (early_node_map[i].start_pfn >= max_low_pfn)
4038 if (end_pfn > max_low_pfn)
4039 end_pfn = max_low_pfn;
4041 size_pages = end_pfn - early_node_map[i].start_pfn;
4042 free_bootmem_node(NODE_DATA(early_node_map[i].nid),
4043 PFN_PHYS(early_node_map[i].start_pfn),
4044 size_pages << PAGE_SHIFT);
4048 #ifdef CONFIG_HAVE_MEMBLOCK
4050 * Basic iterator support. Return the last range of PFNs for a node
4051 * Note: nid == MAX_NUMNODES returns last region regardless of node
4053 static int __meminit last_active_region_index_in_nid(int nid)
4057 for (i = nr_nodemap_entries - 1; i >= 0; i--)
4058 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
4065 * Basic iterator support. Return the previous active range of PFNs for a node
4066 * Note: nid == MAX_NUMNODES returns next region regardless of node
4068 static int __meminit previous_active_region_index_in_nid(int index, int nid)
4070 for (index = index - 1; index >= 0; index--)
4071 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
4077 #define for_each_active_range_index_in_nid_reverse(i, nid) \
4078 for (i = last_active_region_index_in_nid(nid); i != -1; \
4079 i = previous_active_region_index_in_nid(i, nid))
4081 u64 __init find_memory_core_early(int nid, u64 size, u64 align,
4082 u64 goal, u64 limit)
4086 /* Need to go over early_node_map to find out good range for node */
4087 for_each_active_range_index_in_nid_reverse(i, nid) {
4089 u64 ei_start, ei_last;
4090 u64 final_start, final_end;
4092 ei_last = early_node_map[i].end_pfn;
4093 ei_last <<= PAGE_SHIFT;
4094 ei_start = early_node_map[i].start_pfn;
4095 ei_start <<= PAGE_SHIFT;
4097 final_start = max(ei_start, goal);
4098 final_end = min(ei_last, limit);
4100 if (final_start >= final_end)
4103 addr = memblock_find_in_range(final_start, final_end, size, align);
4105 if (addr == MEMBLOCK_ERROR)
4111 return MEMBLOCK_ERROR;
4115 int __init add_from_early_node_map(struct range *range, int az,
4116 int nr_range, int nid)
4121 /* need to go over early_node_map to find out good range for node */
4122 for_each_active_range_index_in_nid(i, nid) {
4123 start = early_node_map[i].start_pfn;
4124 end = early_node_map[i].end_pfn;
4125 nr_range = add_range(range, az, nr_range, start, end);
4130 void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
4135 for_each_active_range_index_in_nid(i, nid) {
4136 ret = work_fn(early_node_map[i].start_pfn,
4137 early_node_map[i].end_pfn, data);
4143 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4144 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4146 * If an architecture guarantees that all ranges registered with
4147 * add_active_ranges() contain no holes and may be freed, this
4148 * function may be used instead of calling memory_present() manually.
4150 void __init sparse_memory_present_with_active_regions(int nid)
4154 for_each_active_range_index_in_nid(i, nid)
4155 memory_present(early_node_map[i].nid,
4156 early_node_map[i].start_pfn,
4157 early_node_map[i].end_pfn);
4161 * get_pfn_range_for_nid - Return the start and end page frames for a node
4162 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4163 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4164 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4166 * It returns the start and end page frame of a node based on information
4167 * provided by an arch calling add_active_range(). If called for a node
4168 * with no available memory, a warning is printed and the start and end
4171 void __meminit get_pfn_range_for_nid(unsigned int nid,
4172 unsigned long *start_pfn, unsigned long *end_pfn)
4178 for_each_active_range_index_in_nid(i, nid) {
4179 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
4180 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
4183 if (*start_pfn == -1UL)
4188 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4189 * assumption is made that zones within a node are ordered in monotonic
4190 * increasing memory addresses so that the "highest" populated zone is used
4192 static void __init find_usable_zone_for_movable(void)
4195 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4196 if (zone_index == ZONE_MOVABLE)
4199 if (arch_zone_highest_possible_pfn[zone_index] >
4200 arch_zone_lowest_possible_pfn[zone_index])
4204 VM_BUG_ON(zone_index == -1);
4205 movable_zone = zone_index;
4209 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4210 * because it is sized independent of architecture. Unlike the other zones,
4211 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4212 * in each node depending on the size of each node and how evenly kernelcore
4213 * is distributed. This helper function adjusts the zone ranges
4214 * provided by the architecture for a given node by using the end of the
4215 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4216 * zones within a node are in order of monotonic increases memory addresses
4218 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4219 unsigned long zone_type,
4220 unsigned long node_start_pfn,
4221 unsigned long node_end_pfn,
4222 unsigned long *zone_start_pfn,
4223 unsigned long *zone_end_pfn)
4225 /* Only adjust if ZONE_MOVABLE is on this node */
4226 if (zone_movable_pfn[nid]) {
4227 /* Size ZONE_MOVABLE */
4228 if (zone_type == ZONE_MOVABLE) {
4229 *zone_start_pfn = zone_movable_pfn[nid];
4230 *zone_end_pfn = min(node_end_pfn,
4231 arch_zone_highest_possible_pfn[movable_zone]);
4233 /* Adjust for ZONE_MOVABLE starting within this range */
4234 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4235 *zone_end_pfn > zone_movable_pfn[nid]) {
4236 *zone_end_pfn = zone_movable_pfn[nid];
4238 /* Check if this whole range is within ZONE_MOVABLE */
4239 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4240 *zone_start_pfn = *zone_end_pfn;
4245 * Return the number of pages a zone spans in a node, including holes
4246 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4248 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4249 unsigned long zone_type,
4250 unsigned long *ignored)
4252 unsigned long node_start_pfn, node_end_pfn;
4253 unsigned long zone_start_pfn, zone_end_pfn;
4255 /* Get the start and end of the node and zone */
4256 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4257 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4258 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4259 adjust_zone_range_for_zone_movable(nid, zone_type,
4260 node_start_pfn, node_end_pfn,
4261 &zone_start_pfn, &zone_end_pfn);
4263 /* Check that this node has pages within the zone's required range */
4264 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4267 /* Move the zone boundaries inside the node if necessary */
4268 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4269 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4271 /* Return the spanned pages */
4272 return zone_end_pfn - zone_start_pfn;
4276 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4277 * then all holes in the requested range will be accounted for.
4279 unsigned long __meminit __absent_pages_in_range(int nid,
4280 unsigned long range_start_pfn,
4281 unsigned long range_end_pfn)
4284 unsigned long prev_end_pfn = 0, hole_pages = 0;
4285 unsigned long start_pfn;
4287 /* Find the end_pfn of the first active range of pfns in the node */
4288 i = first_active_region_index_in_nid(nid);
4292 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
4294 /* Account for ranges before physical memory on this node */
4295 if (early_node_map[i].start_pfn > range_start_pfn)
4296 hole_pages = prev_end_pfn - range_start_pfn;
4298 /* Find all holes for the zone within the node */
4299 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
4301 /* No need to continue if prev_end_pfn is outside the zone */
4302 if (prev_end_pfn >= range_end_pfn)
4305 /* Make sure the end of the zone is not within the hole */
4306 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
4307 prev_end_pfn = max(prev_end_pfn, range_start_pfn);
4309 /* Update the hole size cound and move on */
4310 if (start_pfn > range_start_pfn) {
4311 BUG_ON(prev_end_pfn > start_pfn);
4312 hole_pages += start_pfn - prev_end_pfn;
4314 prev_end_pfn = early_node_map[i].end_pfn;
4317 /* Account for ranges past physical memory on this node */
4318 if (range_end_pfn > prev_end_pfn)
4319 hole_pages += range_end_pfn -
4320 max(range_start_pfn, prev_end_pfn);
4326 * absent_pages_in_range - Return number of page frames in holes within a range
4327 * @start_pfn: The start PFN to start searching for holes
4328 * @end_pfn: The end PFN to stop searching for holes
4330 * It returns the number of pages frames in memory holes within a range.
4332 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4333 unsigned long end_pfn)
4335 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4338 /* Return the number of page frames in holes in a zone on a node */
4339 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4340 unsigned long zone_type,
4341 unsigned long *ignored)
4343 unsigned long node_start_pfn, node_end_pfn;
4344 unsigned long zone_start_pfn, zone_end_pfn;
4346 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4347 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
4349 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
4352 adjust_zone_range_for_zone_movable(nid, zone_type,
4353 node_start_pfn, node_end_pfn,
4354 &zone_start_pfn, &zone_end_pfn);
4355 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4359 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4360 unsigned long zone_type,
4361 unsigned long *zones_size)
4363 return zones_size[zone_type];
4366 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4367 unsigned long zone_type,
4368 unsigned long *zholes_size)
4373 return zholes_size[zone_type];
4378 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4379 unsigned long *zones_size, unsigned long *zholes_size)
4381 unsigned long realtotalpages, totalpages = 0;
4384 for (i = 0; i < MAX_NR_ZONES; i++)
4385 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4387 pgdat->node_spanned_pages = totalpages;
4389 realtotalpages = totalpages;
4390 for (i = 0; i < MAX_NR_ZONES; i++)
4392 zone_absent_pages_in_node(pgdat->node_id, i,
4394 pgdat->node_present_pages = realtotalpages;
4395 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4399 #ifndef CONFIG_SPARSEMEM
4401 * Calculate the size of the zone->blockflags rounded to an unsigned long
4402 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4403 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4404 * round what is now in bits to nearest long in bits, then return it in
4407 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4409 unsigned long usemapsize;
4411 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4412 usemapsize = roundup(zonesize, pageblock_nr_pages);
4413 usemapsize = usemapsize >> pageblock_order;
4414 usemapsize *= NR_PAGEBLOCK_BITS;
4415 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4417 return usemapsize / 8;
4420 static void __init setup_usemap(struct pglist_data *pgdat,
4422 unsigned long zone_start_pfn,
4423 unsigned long zonesize)
4425 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4426 zone->pageblock_flags = NULL;
4428 zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
4432 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4433 unsigned long zone_start_pfn, unsigned long zonesize) {}
4434 #endif /* CONFIG_SPARSEMEM */
4436 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4438 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4439 void __init set_pageblock_order(void)
4443 /* Check that pageblock_nr_pages has not already been setup */
4444 if (pageblock_order)
4447 if (HPAGE_SHIFT > PAGE_SHIFT)
4448 order = HUGETLB_PAGE_ORDER;
4450 order = MAX_ORDER - 1;
4453 * Assume the largest contiguous order of interest is a huge page.
4454 * This value may be variable depending on boot parameters on IA64 and
4457 pageblock_order = order;
4459 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4462 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4463 * is unused as pageblock_order is set at compile-time. See
4464 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4467 void __init set_pageblock_order(void)
4471 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4474 * Set up the zone data structures:
4475 * - mark all pages reserved
4476 * - mark all memory queues empty
4477 * - clear the memory bitmaps
4479 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4480 unsigned long *zones_size, unsigned long *zholes_size)
4483 int nid = pgdat->node_id;
4484 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4487 pgdat_resize_init(pgdat);
4488 pgdat->nr_zones = 0;
4489 init_waitqueue_head(&pgdat->kswapd_wait);
4490 pgdat->kswapd_max_order = 0;
4491 pgdat_page_cgroup_init(pgdat);
4493 for (j = 0; j < MAX_NR_ZONES; j++) {
4494 struct zone *zone = pgdat->node_zones + j;
4495 unsigned long size, realsize, memmap_pages;
4498 size = zone_spanned_pages_in_node(nid, j, zones_size);
4499 realsize = size - zone_absent_pages_in_node(nid, j,
4503 * Adjust realsize so that it accounts for how much memory
4504 * is used by this zone for memmap. This affects the watermark
4505 * and per-cpu initialisations
4508 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4509 if (realsize >= memmap_pages) {
4510 realsize -= memmap_pages;
4513 " %s zone: %lu pages used for memmap\n",
4514 zone_names[j], memmap_pages);
4517 " %s zone: %lu pages exceeds realsize %lu\n",
4518 zone_names[j], memmap_pages, realsize);
4520 /* Account for reserved pages */
4521 if (j == 0 && realsize > dma_reserve) {
4522 realsize -= dma_reserve;
4523 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4524 zone_names[0], dma_reserve);
4527 if (!is_highmem_idx(j))
4528 nr_kernel_pages += realsize;
4529 nr_all_pages += realsize;
4531 zone->spanned_pages = size;
4532 zone->present_pages = realsize;
4535 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4537 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4539 zone->name = zone_names[j];
4540 spin_lock_init(&zone->lock);
4541 spin_lock_init(&zone->lru_lock);
4542 zone_seqlock_init(zone);
4543 zone->zone_pgdat = pgdat;
4545 zone_pcp_init(zone);
4547 INIT_LIST_HEAD(&zone->lru[l].list);
4548 zone->reclaim_stat.recent_rotated[0] = 0;
4549 zone->reclaim_stat.recent_rotated[1] = 0;
4550 zone->reclaim_stat.recent_scanned[0] = 0;
4551 zone->reclaim_stat.recent_scanned[1] = 0;
4552 zap_zone_vm_stats(zone);
4557 set_pageblock_order();
4558 setup_usemap(pgdat, zone, zone_start_pfn, size);
4559 ret = init_currently_empty_zone(zone, zone_start_pfn,
4560 size, MEMMAP_EARLY);
4562 memmap_init(size, nid, j, zone_start_pfn);
4563 zone_start_pfn += size;
4567 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4569 /* Skip empty nodes */
4570 if (!pgdat->node_spanned_pages)
4573 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4574 /* ia64 gets its own node_mem_map, before this, without bootmem */
4575 if (!pgdat->node_mem_map) {
4576 unsigned long size, start, end;
4580 * The zone's endpoints aren't required to be MAX_ORDER
4581 * aligned but the node_mem_map endpoints must be in order
4582 * for the buddy allocator to function correctly.
4584 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4585 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
4586 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4587 size = (end - start) * sizeof(struct page);
4588 map = alloc_remap(pgdat->node_id, size);
4590 map = alloc_bootmem_node_nopanic(pgdat, size);
4591 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4593 #ifndef CONFIG_NEED_MULTIPLE_NODES
4595 * With no DISCONTIG, the global mem_map is just set as node 0's
4597 if (pgdat == NODE_DATA(0)) {
4598 mem_map = NODE_DATA(0)->node_mem_map;
4599 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4600 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4601 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4602 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4605 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4608 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4609 unsigned long node_start_pfn, unsigned long *zholes_size)
4611 pg_data_t *pgdat = NODE_DATA(nid);
4613 pgdat->node_id = nid;
4614 pgdat->node_start_pfn = node_start_pfn;
4615 calculate_node_totalpages(pgdat, zones_size, zholes_size);
4617 alloc_node_mem_map(pgdat);
4618 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4619 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4620 nid, (unsigned long)pgdat,
4621 (unsigned long)pgdat->node_mem_map);
4624 free_area_init_core(pgdat, zones_size, zholes_size);
4627 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4629 #if MAX_NUMNODES > 1
4631 * Figure out the number of possible node ids.
4633 static void __init setup_nr_node_ids(void)
4636 unsigned int highest = 0;
4638 for_each_node_mask(node, node_possible_map)
4640 nr_node_ids = highest + 1;
4643 static inline void setup_nr_node_ids(void)
4649 * add_active_range - Register a range of PFNs backed by physical memory
4650 * @nid: The node ID the range resides on
4651 * @start_pfn: The start PFN of the available physical memory
4652 * @end_pfn: The end PFN of the available physical memory
4654 * These ranges are stored in an early_node_map[] and later used by
4655 * free_area_init_nodes() to calculate zone sizes and holes. If the
4656 * range spans a memory hole, it is up to the architecture to ensure
4657 * the memory is not freed by the bootmem allocator. If possible
4658 * the range being registered will be merged with existing ranges.
4660 void __init add_active_range(unsigned int nid, unsigned long start_pfn,
4661 unsigned long end_pfn)
4665 mminit_dprintk(MMINIT_TRACE, "memory_register",
4666 "Entering add_active_range(%d, %#lx, %#lx) "
4667 "%d entries of %d used\n",
4668 nid, start_pfn, end_pfn,
4669 nr_nodemap_entries, MAX_ACTIVE_REGIONS);
4671 mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
4673 /* Merge with existing active regions if possible */
4674 for (i = 0; i < nr_nodemap_entries; i++) {
4675 if (early_node_map[i].nid != nid)
4678 /* Skip if an existing region covers this new one */
4679 if (start_pfn >= early_node_map[i].start_pfn &&
4680 end_pfn <= early_node_map[i].end_pfn)
4683 /* Merge forward if suitable */
4684 if (start_pfn <= early_node_map[i].end_pfn &&
4685 end_pfn > early_node_map[i].end_pfn) {
4686 early_node_map[i].end_pfn = end_pfn;
4690 /* Merge backward if suitable */
4691 if (start_pfn < early_node_map[i].start_pfn &&
4692 end_pfn >= early_node_map[i].start_pfn) {
4693 early_node_map[i].start_pfn = start_pfn;
4698 /* Check that early_node_map is large enough */
4699 if (i >= MAX_ACTIVE_REGIONS) {
4700 printk(KERN_CRIT "More than %d memory regions, truncating\n",
4701 MAX_ACTIVE_REGIONS);
4705 early_node_map[i].nid = nid;
4706 early_node_map[i].start_pfn = start_pfn;
4707 early_node_map[i].end_pfn = end_pfn;
4708 nr_nodemap_entries = i + 1;
4712 * remove_active_range - Shrink an existing registered range of PFNs
4713 * @nid: The node id the range is on that should be shrunk
4714 * @start_pfn: The new PFN of the range
4715 * @end_pfn: The new PFN of the range
4717 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4718 * The map is kept near the end physical page range that has already been
4719 * registered. This function allows an arch to shrink an existing registered
4722 void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
4723 unsigned long end_pfn)
4728 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
4729 nid, start_pfn, end_pfn);
4731 /* Find the old active region end and shrink */
4732 for_each_active_range_index_in_nid(i, nid) {
4733 if (early_node_map[i].start_pfn >= start_pfn &&
4734 early_node_map[i].end_pfn <= end_pfn) {
4736 early_node_map[i].start_pfn = 0;
4737 early_node_map[i].end_pfn = 0;
4741 if (early_node_map[i].start_pfn < start_pfn &&
4742 early_node_map[i].end_pfn > start_pfn) {
4743 unsigned long temp_end_pfn = early_node_map[i].end_pfn;
4744 early_node_map[i].end_pfn = start_pfn;
4745 if (temp_end_pfn > end_pfn)
4746 add_active_range(nid, end_pfn, temp_end_pfn);
4749 if (early_node_map[i].start_pfn >= start_pfn &&
4750 early_node_map[i].end_pfn > end_pfn &&
4751 early_node_map[i].start_pfn < end_pfn) {
4752 early_node_map[i].start_pfn = end_pfn;
4760 /* remove the blank ones */
4761 for (i = nr_nodemap_entries - 1; i > 0; i--) {
4762 if (early_node_map[i].nid != nid)
4764 if (early_node_map[i].end_pfn)
4766 /* we found it, get rid of it */
4767 for (j = i; j < nr_nodemap_entries - 1; j++)
4768 memcpy(&early_node_map[j], &early_node_map[j+1],
4769 sizeof(early_node_map[j]));
4770 j = nr_nodemap_entries - 1;
4771 memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
4772 nr_nodemap_entries--;
4777 * remove_all_active_ranges - Remove all currently registered regions
4779 * During discovery, it may be found that a table like SRAT is invalid
4780 * and an alternative discovery method must be used. This function removes
4781 * all currently registered regions.
4783 void __init remove_all_active_ranges(void)
4785 memset(early_node_map, 0, sizeof(early_node_map));
4786 nr_nodemap_entries = 0;
4789 /* Compare two active node_active_regions */
4790 static int __init cmp_node_active_region(const void *a, const void *b)
4792 struct node_active_region *arange = (struct node_active_region *)a;
4793 struct node_active_region *brange = (struct node_active_region *)b;
4795 /* Done this way to avoid overflows */
4796 if (arange->start_pfn > brange->start_pfn)
4798 if (arange->start_pfn < brange->start_pfn)
4804 /* sort the node_map by start_pfn */
4805 void __init sort_node_map(void)
4807 sort(early_node_map, (size_t)nr_nodemap_entries,
4808 sizeof(struct node_active_region),
4809 cmp_node_active_region, NULL);
4813 * node_map_pfn_alignment - determine the maximum internode alignment
4815 * This function should be called after node map is populated and sorted.
4816 * It calculates the maximum power of two alignment which can distinguish
4819 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4820 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4821 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4822 * shifted, 1GiB is enough and this function will indicate so.
4824 * This is used to test whether pfn -> nid mapping of the chosen memory
4825 * model has fine enough granularity to avoid incorrect mapping for the
4826 * populated node map.
4828 * Returns the determined alignment in pfn's. 0 if there is no alignment
4829 * requirement (single node).
4831 unsigned long __init node_map_pfn_alignment(void)
4833 unsigned long accl_mask = 0, last_end = 0;
4837 for_each_active_range_index_in_nid(i, MAX_NUMNODES) {
4838 int nid = early_node_map[i].nid;
4839 unsigned long start = early_node_map[i].start_pfn;
4840 unsigned long end = early_node_map[i].end_pfn;
4843 if (!start || last_nid < 0 || last_nid == nid) {
4850 * Start with a mask granular enough to pin-point to the
4851 * start pfn and tick off bits one-by-one until it becomes
4852 * too coarse to separate the current node from the last.
4854 mask = ~((1 << __ffs(start)) - 1);
4855 while (mask && last_end <= (start & (mask << 1)))
4858 /* accumulate all internode masks */
4862 /* convert mask to number of pages */
4863 return ~accl_mask + 1;
4866 /* Find the lowest pfn for a node */
4867 static unsigned long __init find_min_pfn_for_node(int nid)
4870 unsigned long min_pfn = ULONG_MAX;
4872 /* Assuming a sorted map, the first range found has the starting pfn */
4873 for_each_active_range_index_in_nid(i, nid)
4874 min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4876 if (min_pfn == ULONG_MAX) {
4878 "Could not find start_pfn for node %d\n", nid);
4886 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4888 * It returns the minimum PFN based on information provided via
4889 * add_active_range().
4891 unsigned long __init find_min_pfn_with_active_regions(void)
4893 return find_min_pfn_for_node(MAX_NUMNODES);
4897 * early_calculate_totalpages()
4898 * Sum pages in active regions for movable zone.
4899 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4901 static unsigned long __init early_calculate_totalpages(void)
4904 unsigned long totalpages = 0;
4906 for (i = 0; i < nr_nodemap_entries; i++) {
4907 unsigned long pages = early_node_map[i].end_pfn -
4908 early_node_map[i].start_pfn;
4909 totalpages += pages;
4911 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
4917 * Find the PFN the Movable zone begins in each node. Kernel memory
4918 * is spread evenly between nodes as long as the nodes have enough
4919 * memory. When they don't, some nodes will have more kernelcore than
4922 static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
4925 unsigned long usable_startpfn;
4926 unsigned long kernelcore_node, kernelcore_remaining;
4927 /* save the state before borrow the nodemask */
4928 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4929 unsigned long totalpages = early_calculate_totalpages();
4930 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
4933 * If movablecore was specified, calculate what size of
4934 * kernelcore that corresponds so that memory usable for
4935 * any allocation type is evenly spread. If both kernelcore
4936 * and movablecore are specified, then the value of kernelcore
4937 * will be used for required_kernelcore if it's greater than
4938 * what movablecore would have allowed.
4940 if (required_movablecore) {
4941 unsigned long corepages;
4944 * Round-up so that ZONE_MOVABLE is at least as large as what
4945 * was requested by the user
4947 required_movablecore =
4948 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4949 corepages = totalpages - required_movablecore;
4951 required_kernelcore = max(required_kernelcore, corepages);
4954 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4955 if (!required_kernelcore)
4958 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4959 find_usable_zone_for_movable();
4960 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4963 /* Spread kernelcore memory as evenly as possible throughout nodes */
4964 kernelcore_node = required_kernelcore / usable_nodes;
4965 for_each_node_state(nid, N_HIGH_MEMORY) {
4967 * Recalculate kernelcore_node if the division per node
4968 * now exceeds what is necessary to satisfy the requested
4969 * amount of memory for the kernel
4971 if (required_kernelcore < kernelcore_node)
4972 kernelcore_node = required_kernelcore / usable_nodes;
4975 * As the map is walked, we track how much memory is usable
4976 * by the kernel using kernelcore_remaining. When it is
4977 * 0, the rest of the node is usable by ZONE_MOVABLE
4979 kernelcore_remaining = kernelcore_node;
4981 /* Go through each range of PFNs within this node */
4982 for_each_active_range_index_in_nid(i, nid) {
4983 unsigned long start_pfn, end_pfn;
4984 unsigned long size_pages;
4986 start_pfn = max(early_node_map[i].start_pfn,
4987 zone_movable_pfn[nid]);
4988 end_pfn = early_node_map[i].end_pfn;
4989 if (start_pfn >= end_pfn)
4992 /* Account for what is only usable for kernelcore */
4993 if (start_pfn < usable_startpfn) {
4994 unsigned long kernel_pages;
4995 kernel_pages = min(end_pfn, usable_startpfn)
4998 kernelcore_remaining -= min(kernel_pages,
4999 kernelcore_remaining);
5000 required_kernelcore -= min(kernel_pages,
5001 required_kernelcore);
5003 /* Continue if range is now fully accounted */
5004 if (end_pfn <= usable_startpfn) {
5007 * Push zone_movable_pfn to the end so
5008 * that if we have to rebalance
5009 * kernelcore across nodes, we will
5010 * not double account here
5012 zone_movable_pfn[nid] = end_pfn;
5015 start_pfn = usable_startpfn;
5019 * The usable PFN range for ZONE_MOVABLE is from
5020 * start_pfn->end_pfn. Calculate size_pages as the
5021 * number of pages used as kernelcore
5023 size_pages = end_pfn - start_pfn;
5024 if (size_pages > kernelcore_remaining)
5025 size_pages = kernelcore_remaining;
5026 zone_movable_pfn[nid] = start_pfn + size_pages;
5029 * Some kernelcore has been met, update counts and
5030 * break if the kernelcore for this node has been
5033 required_kernelcore -= min(required_kernelcore,
5035 kernelcore_remaining -= size_pages;
5036 if (!kernelcore_remaining)
5042 * If there is still required_kernelcore, we do another pass with one
5043 * less node in the count. This will push zone_movable_pfn[nid] further
5044 * along on the nodes that still have memory until kernelcore is
5048 if (usable_nodes && required_kernelcore > usable_nodes)
5051 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5052 for (nid = 0; nid < MAX_NUMNODES; nid++)
5053 zone_movable_pfn[nid] =
5054 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5057 /* restore the node_state */
5058 node_states[N_HIGH_MEMORY] = saved_node_state;
5061 /* Any regular memory on that node ? */
5062 static void check_for_regular_memory(pg_data_t *pgdat)
5064 #ifdef CONFIG_HIGHMEM
5065 enum zone_type zone_type;
5067 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
5068 struct zone *zone = &pgdat->node_zones[zone_type];
5069 if (zone->present_pages)
5070 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
5076 * free_area_init_nodes - Initialise all pg_data_t and zone data
5077 * @max_zone_pfn: an array of max PFNs for each zone
5079 * This will call free_area_init_node() for each active node in the system.
5080 * Using the page ranges provided by add_active_range(), the size of each
5081 * zone in each node and their holes is calculated. If the maximum PFN
5082 * between two adjacent zones match, it is assumed that the zone is empty.
5083 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5084 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5085 * starts where the previous one ended. For example, ZONE_DMA32 starts
5086 * at arch_max_dma_pfn.
5088 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5093 /* Sort early_node_map as initialisation assumes it is sorted */
5096 /* Record where the zone boundaries are */
5097 memset(arch_zone_lowest_possible_pfn, 0,
5098 sizeof(arch_zone_lowest_possible_pfn));
5099 memset(arch_zone_highest_possible_pfn, 0,
5100 sizeof(arch_zone_highest_possible_pfn));
5101 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5102 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5103 for (i = 1; i < MAX_NR_ZONES; i++) {
5104 if (i == ZONE_MOVABLE)
5106 arch_zone_lowest_possible_pfn[i] =
5107 arch_zone_highest_possible_pfn[i-1];
5108 arch_zone_highest_possible_pfn[i] =
5109 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5111 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5112 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5114 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5115 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5116 find_zone_movable_pfns_for_nodes(zone_movable_pfn);
5118 /* Print out the zone ranges */
5119 printk("Zone PFN ranges:\n");
5120 for (i = 0; i < MAX_NR_ZONES; i++) {
5121 if (i == ZONE_MOVABLE)
5123 printk(" %-8s ", zone_names[i]);
5124 if (arch_zone_lowest_possible_pfn[i] ==
5125 arch_zone_highest_possible_pfn[i])
5128 printk("%0#10lx -> %0#10lx\n",
5129 arch_zone_lowest_possible_pfn[i],
5130 arch_zone_highest_possible_pfn[i]);
5133 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5134 printk("Movable zone start PFN for each node\n");
5135 for (i = 0; i < MAX_NUMNODES; i++) {
5136 if (zone_movable_pfn[i])
5137 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
5140 /* Print out the early_node_map[] */
5141 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
5142 for (i = 0; i < nr_nodemap_entries; i++)
5143 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
5144 early_node_map[i].start_pfn,
5145 early_node_map[i].end_pfn);
5147 /* Initialise every node */
5148 mminit_verify_pageflags_layout();
5149 setup_nr_node_ids();
5150 for_each_online_node(nid) {
5151 pg_data_t *pgdat = NODE_DATA(nid);
5152 free_area_init_node(nid, NULL,
5153 find_min_pfn_for_node(nid), NULL);
5155 /* Any memory on that node */
5156 if (pgdat->node_present_pages)
5157 node_set_state(nid, N_HIGH_MEMORY);
5158 check_for_regular_memory(pgdat);
5162 static int __init cmdline_parse_core(char *p, unsigned long *core)
5164 unsigned long long coremem;
5168 coremem = memparse(p, &p);
5169 *core = coremem >> PAGE_SHIFT;
5171 /* Paranoid check that UL is enough for the coremem value */
5172 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5178 * kernelcore=size sets the amount of memory for use for allocations that
5179 * cannot be reclaimed or migrated.
5181 static int __init cmdline_parse_kernelcore(char *p)
5183 return cmdline_parse_core(p, &required_kernelcore);
5187 * movablecore=size sets the amount of memory for use for allocations that
5188 * can be reclaimed or migrated.
5190 static int __init cmdline_parse_movablecore(char *p)
5192 return cmdline_parse_core(p, &required_movablecore);
5195 early_param("kernelcore", cmdline_parse_kernelcore);
5196 early_param("movablecore", cmdline_parse_movablecore);
5198 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
5201 * set_dma_reserve - set the specified number of pages reserved in the first zone
5202 * @new_dma_reserve: The number of pages to mark reserved
5204 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5205 * In the DMA zone, a significant percentage may be consumed by kernel image
5206 * and other unfreeable allocations which can skew the watermarks badly. This
5207 * function may optionally be used to account for unfreeable pages in the
5208 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5209 * smaller per-cpu batchsize.
5211 void __init set_dma_reserve(unsigned long new_dma_reserve)
5213 dma_reserve = new_dma_reserve;
5216 void __init free_area_init(unsigned long *zones_size)
5218 free_area_init_node(0, zones_size,
5219 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5222 static int page_alloc_cpu_notify(struct notifier_block *self,
5223 unsigned long action, void *hcpu)
5225 int cpu = (unsigned long)hcpu;
5227 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5231 * Spill the event counters of the dead processor
5232 * into the current processors event counters.
5233 * This artificially elevates the count of the current
5236 vm_events_fold_cpu(cpu);
5239 * Zero the differential counters of the dead processor
5240 * so that the vm statistics are consistent.
5242 * This is only okay since the processor is dead and cannot
5243 * race with what we are doing.
5245 refresh_cpu_vm_stats(cpu);
5250 void __init page_alloc_init(void)
5252 hotcpu_notifier(page_alloc_cpu_notify, 0);
5256 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5257 * or min_free_kbytes changes.
5259 static void calculate_totalreserve_pages(void)
5261 struct pglist_data *pgdat;
5262 unsigned long reserve_pages = 0;
5263 enum zone_type i, j;
5265 for_each_online_pgdat(pgdat) {
5266 for (i = 0; i < MAX_NR_ZONES; i++) {
5267 struct zone *zone = pgdat->node_zones + i;
5268 unsigned long max = 0;
5270 /* Find valid and maximum lowmem_reserve in the zone */
5271 for (j = i; j < MAX_NR_ZONES; j++) {
5272 if (zone->lowmem_reserve[j] > max)
5273 max = zone->lowmem_reserve[j];
5276 /* we treat the high watermark as reserved pages. */
5277 max += high_wmark_pages(zone);
5279 if (max > zone->present_pages)
5280 max = zone->present_pages;
5281 reserve_pages += max;
5283 * Lowmem reserves are not available to
5284 * GFP_HIGHUSER page cache allocations and
5285 * kswapd tries to balance zones to their high
5286 * watermark. As a result, neither should be
5287 * regarded as dirtyable memory, to prevent a
5288 * situation where reclaim has to clean pages
5289 * in order to balance the zones.
5291 zone->dirty_balance_reserve = max;
5294 dirty_balance_reserve = reserve_pages;
5295 totalreserve_pages = reserve_pages;
5299 * setup_per_zone_lowmem_reserve - called whenever
5300 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5301 * has a correct pages reserved value, so an adequate number of
5302 * pages are left in the zone after a successful __alloc_pages().
5304 static void setup_per_zone_lowmem_reserve(void)
5306 struct pglist_data *pgdat;
5307 enum zone_type j, idx;
5309 for_each_online_pgdat(pgdat) {
5310 for (j = 0; j < MAX_NR_ZONES; j++) {
5311 struct zone *zone = pgdat->node_zones + j;
5312 unsigned long present_pages = zone->present_pages;
5314 zone->lowmem_reserve[j] = 0;
5318 struct zone *lower_zone;
5322 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5323 sysctl_lowmem_reserve_ratio[idx] = 1;
5325 lower_zone = pgdat->node_zones + idx;
5326 lower_zone->lowmem_reserve[j] = present_pages /
5327 sysctl_lowmem_reserve_ratio[idx];
5328 present_pages += lower_zone->present_pages;
5333 /* update totalreserve_pages */
5334 calculate_totalreserve_pages();
5337 static void __setup_per_zone_wmarks(void)
5339 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5340 unsigned long lowmem_pages = 0;
5342 unsigned long flags;
5344 /* Calculate total number of !ZONE_HIGHMEM pages */
5345 for_each_zone(zone) {
5346 if (!is_highmem(zone))
5347 lowmem_pages += zone->present_pages;
5350 for_each_zone(zone) {
5353 spin_lock_irqsave(&zone->lock, flags);
5354 tmp = (u64)pages_min * zone->present_pages;
5355 do_div(tmp, lowmem_pages);
5356 if (is_highmem(zone)) {
5358 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5359 * need highmem pages, so cap pages_min to a small
5362 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5363 * deltas controls asynch page reclaim, and so should
5364 * not be capped for highmem.
5368 min_pages = zone->present_pages / 1024;
5369 if (min_pages < SWAP_CLUSTER_MAX)
5370 min_pages = SWAP_CLUSTER_MAX;
5371 if (min_pages > 128)
5373 zone->watermark[WMARK_MIN] = min_pages;
5376 * If it's a lowmem zone, reserve a number of pages
5377 * proportionate to the zone's size.
5379 zone->watermark[WMARK_MIN] = tmp;
5382 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5383 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5385 zone->watermark[WMARK_MIN] += cma_wmark_pages(zone);
5386 zone->watermark[WMARK_LOW] += cma_wmark_pages(zone);
5387 zone->watermark[WMARK_HIGH] += cma_wmark_pages(zone);
5389 setup_zone_migrate_reserve(zone);
5390 spin_unlock_irqrestore(&zone->lock, flags);
5393 /* update totalreserve_pages */
5394 calculate_totalreserve_pages();
5398 * setup_per_zone_wmarks - called when min_free_kbytes changes
5399 * or when memory is hot-{added|removed}
5401 * Ensures that the watermark[min,low,high] values for each zone are set
5402 * correctly with respect to min_free_kbytes.
5404 void setup_per_zone_wmarks(void)
5406 mutex_lock(&zonelists_mutex);
5407 __setup_per_zone_wmarks();
5408 mutex_unlock(&zonelists_mutex);
5412 * The inactive anon list should be small enough that the VM never has to
5413 * do too much work, but large enough that each inactive page has a chance
5414 * to be referenced again before it is swapped out.
5416 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5417 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5418 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5419 * the anonymous pages are kept on the inactive list.
5422 * memory ratio inactive anon
5423 * -------------------------------------
5432 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5434 unsigned int gb, ratio;
5436 /* Zone size in gigabytes */
5437 gb = zone->present_pages >> (30 - PAGE_SHIFT);
5439 ratio = int_sqrt(10 * gb);
5443 zone->inactive_ratio = ratio;
5446 static void __meminit setup_per_zone_inactive_ratio(void)
5451 calculate_zone_inactive_ratio(zone);
5455 * Initialise min_free_kbytes.
5457 * For small machines we want it small (128k min). For large machines
5458 * we want it large (64MB max). But it is not linear, because network
5459 * bandwidth does not increase linearly with machine size. We use
5461 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5462 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5478 int __meminit init_per_zone_wmark_min(void)
5480 unsigned long lowmem_kbytes;
5482 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5484 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5485 if (min_free_kbytes < 128)
5486 min_free_kbytes = 128;
5487 if (min_free_kbytes > 65536)
5488 min_free_kbytes = 65536;
5489 setup_per_zone_wmarks();
5490 refresh_zone_stat_thresholds();
5491 setup_per_zone_lowmem_reserve();
5492 setup_per_zone_inactive_ratio();
5495 module_init(init_per_zone_wmark_min)
5498 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5499 * that we can call two helper functions whenever min_free_kbytes
5502 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
5503 void __user *buffer, size_t *length, loff_t *ppos)
5505 proc_dointvec(table, write, buffer, length, ppos);
5507 setup_per_zone_wmarks();
5512 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5513 void __user *buffer, size_t *length, loff_t *ppos)
5518 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5523 zone->min_unmapped_pages = (zone->present_pages *
5524 sysctl_min_unmapped_ratio) / 100;
5528 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5529 void __user *buffer, size_t *length, loff_t *ppos)
5534 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5539 zone->min_slab_pages = (zone->present_pages *
5540 sysctl_min_slab_ratio) / 100;
5546 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5547 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5548 * whenever sysctl_lowmem_reserve_ratio changes.
5550 * The reserve ratio obviously has absolutely no relation with the
5551 * minimum watermarks. The lowmem reserve ratio can only make sense
5552 * if in function of the boot time zone sizes.
5554 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5555 void __user *buffer, size_t *length, loff_t *ppos)
5557 proc_dointvec_minmax(table, write, buffer, length, ppos);
5558 setup_per_zone_lowmem_reserve();
5563 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5564 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5565 * can have before it gets flushed back to buddy allocator.
5568 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
5569 void __user *buffer, size_t *length, loff_t *ppos)
5575 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5576 if (!write || (ret == -EINVAL))
5578 for_each_populated_zone(zone) {
5579 for_each_possible_cpu(cpu) {
5581 high = zone->present_pages / percpu_pagelist_fraction;
5582 setup_pagelist_highmark(
5583 per_cpu_ptr(zone->pageset, cpu), high);
5589 int hashdist = HASHDIST_DEFAULT;
5592 static int __init set_hashdist(char *str)
5596 hashdist = simple_strtoul(str, &str, 0);
5599 __setup("hashdist=", set_hashdist);
5603 * allocate a large system hash table from bootmem
5604 * - it is assumed that the hash table must contain an exact power-of-2
5605 * quantity of entries
5606 * - limit is the number of hash buckets, not the total allocation size
5608 void *__init alloc_large_system_hash(const char *tablename,
5609 unsigned long bucketsize,
5610 unsigned long numentries,
5613 unsigned int *_hash_shift,
5614 unsigned int *_hash_mask,
5615 unsigned long limit)
5617 unsigned long long max = limit;
5618 unsigned long log2qty, size;
5621 /* allow the kernel cmdline to have a say */
5623 /* round applicable memory size up to nearest megabyte */
5624 numentries = nr_kernel_pages;
5625 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
5626 numentries >>= 20 - PAGE_SHIFT;
5627 numentries <<= 20 - PAGE_SHIFT;
5629 /* limit to 1 bucket per 2^scale bytes of low memory */
5630 if (scale > PAGE_SHIFT)
5631 numentries >>= (scale - PAGE_SHIFT);
5633 numentries <<= (PAGE_SHIFT - scale);
5635 /* Make sure we've got at least a 0-order allocation.. */
5636 if (unlikely(flags & HASH_SMALL)) {
5637 /* Makes no sense without HASH_EARLY */
5638 WARN_ON(!(flags & HASH_EARLY));
5639 if (!(numentries >> *_hash_shift)) {
5640 numentries = 1UL << *_hash_shift;
5641 BUG_ON(!numentries);
5643 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5644 numentries = PAGE_SIZE / bucketsize;
5646 numentries = roundup_pow_of_two(numentries);
5648 /* limit allocation size to 1/16 total memory by default */
5650 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5651 do_div(max, bucketsize);
5654 if (numentries > max)
5657 log2qty = ilog2(numentries);
5660 size = bucketsize << log2qty;
5661 if (flags & HASH_EARLY)
5662 table = alloc_bootmem_nopanic(size);
5664 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
5667 * If bucketsize is not a power-of-two, we may free
5668 * some pages at the end of hash table which
5669 * alloc_pages_exact() automatically does
5671 if (get_order(size) < MAX_ORDER) {
5672 table = alloc_pages_exact(size, GFP_ATOMIC);
5673 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
5676 } while (!table && size > PAGE_SIZE && --log2qty);
5679 panic("Failed to allocate %s hash table\n", tablename);
5681 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
5684 ilog2(size) - PAGE_SHIFT,
5688 *_hash_shift = log2qty;
5690 *_hash_mask = (1 << log2qty) - 1;
5695 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5696 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
5699 #ifdef CONFIG_SPARSEMEM
5700 return __pfn_to_section(pfn)->pageblock_flags;
5702 return zone->pageblock_flags;
5703 #endif /* CONFIG_SPARSEMEM */
5706 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
5708 #ifdef CONFIG_SPARSEMEM
5709 pfn &= (PAGES_PER_SECTION-1);
5710 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5712 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
5713 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5714 #endif /* CONFIG_SPARSEMEM */
5718 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5719 * @page: The page within the block of interest
5720 * @start_bitidx: The first bit of interest to retrieve
5721 * @end_bitidx: The last bit of interest
5722 * returns pageblock_bits flags
5724 unsigned long get_pageblock_flags_group(struct page *page,
5725 int start_bitidx, int end_bitidx)
5728 unsigned long *bitmap;
5729 unsigned long pfn, bitidx;
5730 unsigned long flags = 0;
5731 unsigned long value = 1;
5733 zone = page_zone(page);
5734 pfn = page_to_pfn(page);
5735 bitmap = get_pageblock_bitmap(zone, pfn);
5736 bitidx = pfn_to_bitidx(zone, pfn);
5738 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5739 if (test_bit(bitidx + start_bitidx, bitmap))
5746 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5747 * @page: The page within the block of interest
5748 * @start_bitidx: The first bit of interest
5749 * @end_bitidx: The last bit of interest
5750 * @flags: The flags to set
5752 void set_pageblock_flags_group(struct page *page, unsigned long flags,
5753 int start_bitidx, int end_bitidx)
5756 unsigned long *bitmap;
5757 unsigned long pfn, bitidx;
5758 unsigned long value = 1;
5760 zone = page_zone(page);
5761 pfn = page_to_pfn(page);
5762 bitmap = get_pageblock_bitmap(zone, pfn);
5763 bitidx = pfn_to_bitidx(zone, pfn);
5764 VM_BUG_ON(pfn < zone->zone_start_pfn);
5765 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5767 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5769 __set_bit(bitidx + start_bitidx, bitmap);
5771 __clear_bit(bitidx + start_bitidx, bitmap);
5775 * This is designed as sub function...plz see page_isolation.c also.
5776 * set/clear page block's type to be ISOLATE.
5777 * page allocater never alloc memory from ISOLATE block.
5781 __count_immobile_pages(struct zone *zone, struct page *page, int count)
5783 unsigned long pfn, iter, found;
5787 * For avoiding noise data, lru_add_drain_all() should be called
5788 * If ZONE_MOVABLE, the zone never contains immobile pages
5790 if (zone_idx(zone) == ZONE_MOVABLE)
5792 mt = get_pageblock_migratetype(page);
5793 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
5796 pfn = page_to_pfn(page);
5797 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
5798 unsigned long check = pfn + iter;
5800 if (!pfn_valid_within(check))
5803 page = pfn_to_page(check);
5804 if (!page_count(page)) {
5805 if (PageBuddy(page))
5806 iter += (1 << page_order(page)) - 1;
5812 * If there are RECLAIMABLE pages, we need to check it.
5813 * But now, memory offline itself doesn't call shrink_slab()
5814 * and it still to be fixed.
5817 * If the page is not RAM, page_count()should be 0.
5818 * we don't need more check. This is an _used_ not-movable page.
5820 * The problematic thing here is PG_reserved pages. PG_reserved
5821 * is set to both of a memory hole page and a _used_ kernel
5830 bool is_pageblock_removable_nolock(struct page *page)
5832 struct zone *zone = page_zone(page);
5833 unsigned long pfn = page_to_pfn(page);
5836 * We have to be careful here because we are iterating over memory
5837 * sections which are not zone aware so we might end up outside of
5838 * the zone but still within the section.
5840 if (!zone || zone->zone_start_pfn > pfn ||
5841 zone->zone_start_pfn + zone->spanned_pages <= pfn)
5844 return __count_immobile_pages(zone, page, 0);
5847 int set_migratetype_isolate(struct page *page)
5850 unsigned long flags, pfn;
5851 struct memory_isolate_notify arg;
5855 zone = page_zone(page);
5857 spin_lock_irqsave(&zone->lock, flags);
5859 pfn = page_to_pfn(page);
5860 arg.start_pfn = pfn;
5861 arg.nr_pages = pageblock_nr_pages;
5862 arg.pages_found = 0;
5865 * It may be possible to isolate a pageblock even if the
5866 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5867 * notifier chain is used by balloon drivers to return the
5868 * number of pages in a range that are held by the balloon
5869 * driver to shrink memory. If all the pages are accounted for
5870 * by balloons, are free, or on the LRU, isolation can continue.
5871 * Later, for example, when memory hotplug notifier runs, these
5872 * pages reported as "can be isolated" should be isolated(freed)
5873 * by the balloon driver through the memory notifier chain.
5875 notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
5876 notifier_ret = notifier_to_errno(notifier_ret);
5880 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5881 * We just check MOVABLE pages.
5883 if (__count_immobile_pages(zone, page, arg.pages_found))
5887 * immobile means "not-on-lru" paes. If immobile is larger than
5888 * removable-by-driver pages reported by notifier, we'll fail.
5893 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
5894 move_freepages_block(zone, page, MIGRATE_ISOLATE);
5897 spin_unlock_irqrestore(&zone->lock, flags);
5903 void unset_migratetype_isolate(struct page *page, unsigned migratetype)
5906 unsigned long flags;
5907 zone = page_zone(page);
5908 spin_lock_irqsave(&zone->lock, flags);
5909 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
5911 set_pageblock_migratetype(page, migratetype);
5912 move_freepages_block(zone, page, migratetype);
5914 spin_unlock_irqrestore(&zone->lock, flags);
5919 static unsigned long pfn_max_align_down(unsigned long pfn)
5921 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
5922 pageblock_nr_pages) - 1);
5925 static unsigned long pfn_max_align_up(unsigned long pfn)
5927 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
5928 pageblock_nr_pages));
5931 static struct page *
5932 __alloc_contig_migrate_alloc(struct page *page, unsigned long private,
5935 gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
5937 if (PageHighMem(page))
5938 gfp_mask |= __GFP_HIGHMEM;
5940 return alloc_page(gfp_mask);
5943 /* [start, end) must belong to a single zone. */
5944 static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
5946 /* This function is based on compact_zone() from compaction.c. */
5948 unsigned long pfn = start;
5949 unsigned int tries = 0;
5952 struct compact_control cc = {
5953 .nr_migratepages = 0,
5955 .zone = page_zone(pfn_to_page(start)),
5958 INIT_LIST_HEAD(&cc.migratepages);
5960 migrate_prep_local();
5962 while (pfn < end || !list_empty(&cc.migratepages)) {
5963 if (fatal_signal_pending(current)) {
5968 if (list_empty(&cc.migratepages)) {
5969 cc.nr_migratepages = 0;
5970 pfn = isolate_migratepages_range(cc.zone, &cc,
5977 } else if (++tries == 5) {
5978 ret = ret < 0 ? ret : -EBUSY;
5982 ret = migrate_pages(&cc.migratepages,
5983 __alloc_contig_migrate_alloc,
5984 0, false, MIGRATE_SYNC);
5987 putback_lru_pages(&cc.migratepages);
5988 return ret > 0 ? 0 : ret;
5992 * Update zone's cma pages counter used for watermark level calculation.
5994 static inline void __update_cma_watermarks(struct zone *zone, int count)
5996 unsigned long flags;
5997 spin_lock_irqsave(&zone->lock, flags);
5998 zone->min_cma_pages += count;
5999 spin_unlock_irqrestore(&zone->lock, flags);
6000 setup_per_zone_wmarks();
6004 * Trigger memory pressure bump to reclaim some pages in order to be able to
6005 * allocate 'count' pages in single page units. Does similar work as
6006 *__alloc_pages_slowpath() function.
6008 static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count)
6010 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
6011 struct zonelist *zonelist = node_zonelist(0, gfp_mask);
6012 int did_some_progress = 0;
6016 * Increase level of watermarks to force kswapd do his job
6017 * to stabilise at new watermark level.
6019 __update_cma_watermarks(zone, count);
6021 /* Obey watermarks as if the page was being allocated */
6022 while (!zone_watermark_ok(zone, 0, low_wmark_pages(zone), 0, 0)) {
6023 wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone));
6025 did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
6027 if (!did_some_progress) {
6028 /* Exhausted what can be done so it's blamo time */
6029 out_of_memory(zonelist, gfp_mask, order, NULL);
6033 /* Restore original watermark levels. */
6034 __update_cma_watermarks(zone, -count);
6040 * alloc_contig_range() -- tries to allocate given range of pages
6041 * @start: start PFN to allocate
6042 * @end: one-past-the-last PFN to allocate
6043 * @migratetype: migratetype of the underlaying pageblocks (either
6044 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6045 * in range must have the same migratetype and it must
6046 * be either of the two.
6048 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6049 * aligned, however it's the caller's responsibility to guarantee that
6050 * we are the only thread that changes migrate type of pageblocks the
6053 * The PFN range must belong to a single zone.
6055 * Returns zero on success or negative error code. On success all
6056 * pages which PFN is in [start, end) are allocated for the caller and
6057 * need to be freed with free_contig_range().
6059 int alloc_contig_range(unsigned long start, unsigned long end,
6060 unsigned migratetype)
6062 struct zone *zone = page_zone(pfn_to_page(start));
6063 unsigned long outer_start, outer_end;
6067 * What we do here is we mark all pageblocks in range as
6068 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6069 * have different sizes, and due to the way page allocator
6070 * work, we align the range to biggest of the two pages so
6071 * that page allocator won't try to merge buddies from
6072 * different pageblocks and change MIGRATE_ISOLATE to some
6073 * other migration type.
6075 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6076 * migrate the pages from an unaligned range (ie. pages that
6077 * we are interested in). This will put all the pages in
6078 * range back to page allocator as MIGRATE_ISOLATE.
6080 * When this is done, we take the pages in range from page
6081 * allocator removing them from the buddy system. This way
6082 * page allocator will never consider using them.
6084 * This lets us mark the pageblocks back as
6085 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6086 * aligned range but not in the unaligned, original range are
6087 * put back to page allocator so that buddy can use them.
6090 ret = start_isolate_page_range(pfn_max_align_down(start),
6091 pfn_max_align_up(end), migratetype);
6095 ret = __alloc_contig_migrate_range(start, end);
6100 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6101 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6102 * more, all pages in [start, end) are free in page allocator.
6103 * What we are going to do is to allocate all pages from
6104 * [start, end) (that is remove them from page allocator).
6106 * The only problem is that pages at the beginning and at the
6107 * end of interesting range may be not aligned with pages that
6108 * page allocator holds, ie. they can be part of higher order
6109 * pages. Because of this, we reserve the bigger range and
6110 * once this is done free the pages we are not interested in.
6112 * We don't have to hold zone->lock here because the pages are
6113 * isolated thus they won't get removed from buddy.
6116 lru_add_drain_all();
6120 outer_start = start;
6121 while (!PageBuddy(pfn_to_page(outer_start))) {
6122 if (++order >= MAX_ORDER) {
6126 outer_start &= ~0UL << order;
6129 /* Make sure the range is really isolated. */
6130 if (test_pages_isolated(outer_start, end)) {
6131 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
6138 * Reclaim enough pages to make sure that contiguous allocation
6139 * will not starve the system.
6141 __reclaim_pages(zone, GFP_HIGHUSER_MOVABLE, end-start);
6143 /* Grab isolated pages from freelists. */
6144 outer_end = isolate_freepages_range(outer_start, end);
6150 /* Free head and tail (if any) */
6151 if (start != outer_start)
6152 free_contig_range(outer_start, start - outer_start);
6153 if (end != outer_end)
6154 free_contig_range(end, outer_end - end);
6157 undo_isolate_page_range(pfn_max_align_down(start),
6158 pfn_max_align_up(end), migratetype);
6162 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6164 for (; nr_pages--; ++pfn)
6165 __free_page(pfn_to_page(pfn));
6169 #ifdef CONFIG_MEMORY_HOTREMOVE
6171 * All pages in the range must be isolated before calling this.
6174 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6180 unsigned long flags;
6181 /* find the first valid pfn */
6182 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6187 zone = page_zone(pfn_to_page(pfn));
6188 spin_lock_irqsave(&zone->lock, flags);
6190 while (pfn < end_pfn) {
6191 if (!pfn_valid(pfn)) {
6195 page = pfn_to_page(pfn);
6196 BUG_ON(page_count(page));
6197 BUG_ON(!PageBuddy(page));
6198 order = page_order(page);
6199 #ifdef CONFIG_DEBUG_VM
6200 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6201 pfn, 1 << order, end_pfn);
6203 list_del(&page->lru);
6204 rmv_page_order(page);
6205 zone->free_area[order].nr_free--;
6206 __mod_zone_page_state(zone, NR_FREE_PAGES,
6208 #ifdef CONFIG_HIGHMEM
6209 if (PageHighMem(page))
6210 totalhigh_pages -= 1 << order;
6212 for (i = 0; i < (1 << order); i++)
6213 SetPageReserved((page+i));
6214 pfn += (1 << order);
6216 spin_unlock_irqrestore(&zone->lock, flags);
6220 #ifdef CONFIG_MEMORY_FAILURE
6221 bool is_free_buddy_page(struct page *page)
6223 struct zone *zone = page_zone(page);
6224 unsigned long pfn = page_to_pfn(page);
6225 unsigned long flags;
6228 spin_lock_irqsave(&zone->lock, flags);
6229 for (order = 0; order < MAX_ORDER; order++) {
6230 struct page *page_head = page - (pfn & ((1 << order) - 1));
6232 if (PageBuddy(page_head) && page_order(page_head) >= order)
6235 spin_unlock_irqrestore(&zone->lock, flags);
6237 return order < MAX_ORDER;
6241 static struct trace_print_flags pageflag_names[] = {
6242 {1UL << PG_locked, "locked" },
6243 {1UL << PG_error, "error" },
6244 {1UL << PG_referenced, "referenced" },
6245 {1UL << PG_uptodate, "uptodate" },
6246 {1UL << PG_dirty, "dirty" },
6247 {1UL << PG_lru, "lru" },
6248 {1UL << PG_active, "active" },
6249 {1UL << PG_slab, "slab" },
6250 {1UL << PG_owner_priv_1, "owner_priv_1" },
6251 {1UL << PG_arch_1, "arch_1" },
6252 {1UL << PG_reserved, "reserved" },
6253 {1UL << PG_private, "private" },
6254 {1UL << PG_private_2, "private_2" },
6255 {1UL << PG_writeback, "writeback" },
6256 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6257 {1UL << PG_head, "head" },
6258 {1UL << PG_tail, "tail" },
6260 {1UL << PG_compound, "compound" },
6262 {1UL << PG_swapcache, "swapcache" },
6263 {1UL << PG_mappedtodisk, "mappedtodisk" },
6264 {1UL << PG_reclaim, "reclaim" },
6265 {1UL << PG_swapbacked, "swapbacked" },
6266 {1UL << PG_unevictable, "unevictable" },
6268 {1UL << PG_mlocked, "mlocked" },
6270 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6271 {1UL << PG_uncached, "uncached" },
6273 #ifdef CONFIG_MEMORY_FAILURE
6274 {1UL << PG_hwpoison, "hwpoison" },
6279 static void dump_page_flags(unsigned long flags)
6281 const char *delim = "";
6285 printk(KERN_ALERT "page flags: %#lx(", flags);
6287 /* remove zone id */
6288 flags &= (1UL << NR_PAGEFLAGS) - 1;
6290 for (i = 0; pageflag_names[i].name && flags; i++) {
6292 mask = pageflag_names[i].mask;
6293 if ((flags & mask) != mask)
6297 printk("%s%s", delim, pageflag_names[i].name);
6301 /* check for left over flags */
6303 printk("%s%#lx", delim, flags);
6308 void dump_page(struct page *page)
6311 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6312 page, atomic_read(&page->_count), page_mapcount(page),
6313 page->mapping, page->index);
6314 dump_page_flags(page->flags);
6315 mem_cgroup_print_bad_page(page);