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>
61 #include <asm/tlbflush.h>
62 #include <asm/div64.h>
65 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
66 DEFINE_PER_CPU(int, numa_node);
67 EXPORT_PER_CPU_SYMBOL(numa_node);
70 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
72 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
73 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
74 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
75 * defined in <linux/topology.h>.
77 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
78 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
82 * Array of node states.
84 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
85 [N_POSSIBLE] = NODE_MASK_ALL,
86 [N_ONLINE] = { { [0] = 1UL } },
88 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
90 [N_HIGH_MEMORY] = { { [0] = 1UL } },
92 [N_CPU] = { { [0] = 1UL } },
95 EXPORT_SYMBOL(node_states);
97 unsigned long totalram_pages __read_mostly;
98 unsigned long totalreserve_pages __read_mostly;
99 int percpu_pagelist_fraction;
100 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
102 #ifdef CONFIG_PM_SLEEP
104 * The following functions are used by the suspend/hibernate code to temporarily
105 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
106 * while devices are suspended. To avoid races with the suspend/hibernate code,
107 * they should always be called with pm_mutex held (gfp_allowed_mask also should
108 * only be modified with pm_mutex held, unless the suspend/hibernate code is
109 * guaranteed not to run in parallel with that modification).
112 static gfp_t saved_gfp_mask;
114 void pm_restore_gfp_mask(void)
116 WARN_ON(!mutex_is_locked(&pm_mutex));
117 if (saved_gfp_mask) {
118 gfp_allowed_mask = saved_gfp_mask;
123 void pm_restrict_gfp_mask(void)
125 WARN_ON(!mutex_is_locked(&pm_mutex));
126 WARN_ON(saved_gfp_mask);
127 saved_gfp_mask = gfp_allowed_mask;
128 gfp_allowed_mask &= ~GFP_IOFS;
130 #endif /* CONFIG_PM_SLEEP */
132 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
133 int pageblock_order __read_mostly;
136 static void __free_pages_ok(struct page *page, unsigned int order);
139 * results with 256, 32 in the lowmem_reserve sysctl:
140 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
141 * 1G machine -> (16M dma, 784M normal, 224M high)
142 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
143 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
144 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
146 * TBD: should special case ZONE_DMA32 machines here - in those we normally
147 * don't need any ZONE_NORMAL reservation
149 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
150 #ifdef CONFIG_ZONE_DMA
153 #ifdef CONFIG_ZONE_DMA32
156 #ifdef CONFIG_HIGHMEM
162 EXPORT_SYMBOL(totalram_pages);
164 static char * const zone_names[MAX_NR_ZONES] = {
165 #ifdef CONFIG_ZONE_DMA
168 #ifdef CONFIG_ZONE_DMA32
172 #ifdef CONFIG_HIGHMEM
178 int min_free_kbytes = 1024;
180 static unsigned long __meminitdata nr_kernel_pages;
181 static unsigned long __meminitdata nr_all_pages;
182 static unsigned long __meminitdata dma_reserve;
184 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
186 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
187 * ranges of memory (RAM) that may be registered with add_active_range().
188 * Ranges passed to add_active_range() will be merged if possible
189 * so the number of times add_active_range() can be called is
190 * related to the number of nodes and the number of holes
192 #ifdef CONFIG_MAX_ACTIVE_REGIONS
193 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
194 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
196 #if MAX_NUMNODES >= 32
197 /* If there can be many nodes, allow up to 50 holes per node */
198 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
200 /* By default, allow up to 256 distinct regions */
201 #define MAX_ACTIVE_REGIONS 256
205 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
206 static int __meminitdata nr_nodemap_entries;
207 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
208 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
209 static unsigned long __initdata required_kernelcore;
210 static unsigned long __initdata required_movablecore;
211 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
213 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
215 EXPORT_SYMBOL(movable_zone);
216 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
219 int nr_node_ids __read_mostly = MAX_NUMNODES;
220 int nr_online_nodes __read_mostly = 1;
221 EXPORT_SYMBOL(nr_node_ids);
222 EXPORT_SYMBOL(nr_online_nodes);
225 int page_group_by_mobility_disabled __read_mostly;
227 static void set_pageblock_migratetype(struct page *page, int migratetype)
230 if (unlikely(page_group_by_mobility_disabled))
231 migratetype = MIGRATE_UNMOVABLE;
233 set_pageblock_flags_group(page, (unsigned long)migratetype,
234 PB_migrate, PB_migrate_end);
237 bool oom_killer_disabled __read_mostly;
239 #ifdef CONFIG_DEBUG_VM
240 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
244 unsigned long pfn = page_to_pfn(page);
247 seq = zone_span_seqbegin(zone);
248 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
250 else if (pfn < zone->zone_start_pfn)
252 } while (zone_span_seqretry(zone, seq));
257 static int page_is_consistent(struct zone *zone, struct page *page)
259 if (!pfn_valid_within(page_to_pfn(page)))
261 if (zone != page_zone(page))
267 * Temporary debugging check for pages not lying within a given zone.
269 static int bad_range(struct zone *zone, struct page *page)
271 if (page_outside_zone_boundaries(zone, page))
273 if (!page_is_consistent(zone, page))
279 static inline int bad_range(struct zone *zone, struct page *page)
285 static void bad_page(struct page *page)
287 static unsigned long resume;
288 static unsigned long nr_shown;
289 static unsigned long nr_unshown;
291 /* Don't complain about poisoned pages */
292 if (PageHWPoison(page)) {
293 reset_page_mapcount(page); /* remove PageBuddy */
298 * Allow a burst of 60 reports, then keep quiet for that minute;
299 * or allow a steady drip of one report per second.
301 if (nr_shown == 60) {
302 if (time_before(jiffies, resume)) {
308 "BUG: Bad page state: %lu messages suppressed\n",
315 resume = jiffies + 60 * HZ;
317 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
318 current->comm, page_to_pfn(page));
324 /* Leave bad fields for debug, except PageBuddy could make trouble */
325 reset_page_mapcount(page); /* remove PageBuddy */
326 add_taint(TAINT_BAD_PAGE);
330 * Higher-order pages are called "compound pages". They are structured thusly:
332 * The first PAGE_SIZE page is called the "head page".
334 * The remaining PAGE_SIZE pages are called "tail pages".
336 * All pages have PG_compound set. All pages have their ->private pointing at
337 * the head page (even the head page has this).
339 * The first tail page's ->lru.next holds the address of the compound page's
340 * put_page() function. Its ->lru.prev holds the order of allocation.
341 * This usage means that zero-order pages may not be compound.
344 static void free_compound_page(struct page *page)
346 __free_pages_ok(page, compound_order(page));
349 void prep_compound_page(struct page *page, unsigned long order)
352 int nr_pages = 1 << order;
354 set_compound_page_dtor(page, free_compound_page);
355 set_compound_order(page, order);
357 for (i = 1; i < nr_pages; i++) {
358 struct page *p = page + i;
360 set_page_count(p, 0);
361 p->first_page = page;
365 /* update __split_huge_page_refcount if you change this function */
366 static int destroy_compound_page(struct page *page, unsigned long order)
369 int nr_pages = 1 << order;
372 if (unlikely(compound_order(page) != order) ||
373 unlikely(!PageHead(page))) {
378 __ClearPageHead(page);
380 for (i = 1; i < nr_pages; i++) {
381 struct page *p = page + i;
383 if (unlikely(!PageTail(p) || (p->first_page != page))) {
393 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
398 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
399 * and __GFP_HIGHMEM from hard or soft interrupt context.
401 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
402 for (i = 0; i < (1 << order); i++)
403 clear_highpage(page + i);
406 static inline void set_page_order(struct page *page, int order)
408 set_page_private(page, order);
409 __SetPageBuddy(page);
412 static inline void rmv_page_order(struct page *page)
414 __ClearPageBuddy(page);
415 set_page_private(page, 0);
419 * Locate the struct page for both the matching buddy in our
420 * pair (buddy1) and the combined O(n+1) page they form (page).
422 * 1) Any buddy B1 will have an order O twin B2 which satisfies
423 * the following equation:
425 * For example, if the starting buddy (buddy2) is #8 its order
427 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
429 * 2) Any buddy B will have an order O+1 parent P which
430 * satisfies the following equation:
433 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
435 static inline unsigned long
436 __find_buddy_index(unsigned long page_idx, unsigned int order)
438 return page_idx ^ (1 << order);
442 * This function checks whether a page is free && is the buddy
443 * we can do coalesce a page and its buddy if
444 * (a) the buddy is not in a hole &&
445 * (b) the buddy is in the buddy system &&
446 * (c) a page and its buddy have the same order &&
447 * (d) a page and its buddy are in the same zone.
449 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
450 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
452 * For recording page's order, we use page_private(page).
454 static inline int page_is_buddy(struct page *page, struct page *buddy,
457 if (!pfn_valid_within(page_to_pfn(buddy)))
460 if (page_zone_id(page) != page_zone_id(buddy))
463 if (PageBuddy(buddy) && page_order(buddy) == order) {
464 VM_BUG_ON(page_count(buddy) != 0);
471 * Freeing function for a buddy system allocator.
473 * The concept of a buddy system is to maintain direct-mapped table
474 * (containing bit values) for memory blocks of various "orders".
475 * The bottom level table contains the map for the smallest allocatable
476 * units of memory (here, pages), and each level above it describes
477 * pairs of units from the levels below, hence, "buddies".
478 * At a high level, all that happens here is marking the table entry
479 * at the bottom level available, and propagating the changes upward
480 * as necessary, plus some accounting needed to play nicely with other
481 * parts of the VM system.
482 * At each level, we keep a list of pages, which are heads of continuous
483 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
484 * order is recorded in page_private(page) field.
485 * So when we are allocating or freeing one, we can derive the state of the
486 * other. That is, if we allocate a small block, and both were
487 * free, the remainder of the region must be split into blocks.
488 * If a block is freed, and its buddy is also free, then this
489 * triggers coalescing into a block of larger size.
494 static inline void __free_one_page(struct page *page,
495 struct zone *zone, unsigned int order,
498 unsigned long page_idx;
499 unsigned long combined_idx;
500 unsigned long uninitialized_var(buddy_idx);
503 if (unlikely(PageCompound(page)))
504 if (unlikely(destroy_compound_page(page, order)))
507 VM_BUG_ON(migratetype == -1);
509 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
511 VM_BUG_ON(page_idx & ((1 << order) - 1));
512 VM_BUG_ON(bad_range(zone, page));
514 while (order < MAX_ORDER-1) {
515 buddy_idx = __find_buddy_index(page_idx, order);
516 buddy = page + (buddy_idx - page_idx);
517 if (!page_is_buddy(page, buddy, order))
520 /* Our buddy is free, merge with it and move up one order. */
521 list_del(&buddy->lru);
522 zone->free_area[order].nr_free--;
523 rmv_page_order(buddy);
524 combined_idx = buddy_idx & page_idx;
525 page = page + (combined_idx - page_idx);
526 page_idx = combined_idx;
529 set_page_order(page, order);
532 * If this is not the largest possible page, check if the buddy
533 * of the next-highest order is free. If it is, it's possible
534 * that pages are being freed that will coalesce soon. In case,
535 * that is happening, add the free page to the tail of the list
536 * so it's less likely to be used soon and more likely to be merged
537 * as a higher order page
539 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
540 struct page *higher_page, *higher_buddy;
541 combined_idx = buddy_idx & page_idx;
542 higher_page = page + (combined_idx - page_idx);
543 buddy_idx = __find_buddy_index(combined_idx, order + 1);
544 higher_buddy = higher_page + (buddy_idx - combined_idx);
545 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
546 list_add_tail(&page->lru,
547 &zone->free_area[order].free_list[migratetype]);
552 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
554 zone->free_area[order].nr_free++;
558 * free_page_mlock() -- clean up attempts to free and mlocked() page.
559 * Page should not be on lru, so no need to fix that up.
560 * free_pages_check() will verify...
562 static inline void free_page_mlock(struct page *page)
564 __dec_zone_page_state(page, NR_MLOCK);
565 __count_vm_event(UNEVICTABLE_MLOCKFREED);
568 static inline int free_pages_check(struct page *page)
570 if (unlikely(page_mapcount(page) |
571 (page->mapping != NULL) |
572 (atomic_read(&page->_count) != 0) |
573 (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
574 (mem_cgroup_bad_page_check(page)))) {
578 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
579 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
584 * Frees a number of pages from the PCP lists
585 * Assumes all pages on list are in same zone, and of same order.
586 * count is the number of pages to free.
588 * If the zone was previously in an "all pages pinned" state then look to
589 * see if this freeing clears that state.
591 * And clear the zone's pages_scanned counter, to hold off the "all pages are
592 * pinned" detection logic.
594 static void free_pcppages_bulk(struct zone *zone, int count,
595 struct per_cpu_pages *pcp)
601 spin_lock(&zone->lock);
602 zone->all_unreclaimable = 0;
603 zone->pages_scanned = 0;
607 struct list_head *list;
610 * Remove pages from lists in a round-robin fashion. A
611 * batch_free count is maintained that is incremented when an
612 * empty list is encountered. This is so more pages are freed
613 * off fuller lists instead of spinning excessively around empty
618 if (++migratetype == MIGRATE_PCPTYPES)
620 list = &pcp->lists[migratetype];
621 } while (list_empty(list));
623 /* This is the only non-empty list. Free them all. */
624 if (batch_free == MIGRATE_PCPTYPES)
625 batch_free = to_free;
628 page = list_entry(list->prev, struct page, lru);
629 /* must delete as __free_one_page list manipulates */
630 list_del(&page->lru);
631 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
632 __free_one_page(page, zone, 0, page_private(page));
633 trace_mm_page_pcpu_drain(page, 0, page_private(page));
634 } while (--to_free && --batch_free && !list_empty(list));
636 __mod_zone_page_state(zone, NR_FREE_PAGES, count);
637 spin_unlock(&zone->lock);
640 static void free_one_page(struct zone *zone, struct page *page, int order,
643 spin_lock(&zone->lock);
644 zone->all_unreclaimable = 0;
645 zone->pages_scanned = 0;
647 __free_one_page(page, zone, order, migratetype);
648 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
649 spin_unlock(&zone->lock);
652 static bool free_pages_prepare(struct page *page, unsigned int order)
657 trace_mm_page_free_direct(page, order);
658 kmemcheck_free_shadow(page, order);
661 page->mapping = NULL;
662 for (i = 0; i < (1 << order); i++)
663 bad += free_pages_check(page + i);
667 if (!PageHighMem(page)) {
668 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
669 debug_check_no_obj_freed(page_address(page),
672 arch_free_page(page, order);
673 kernel_map_pages(page, 1 << order, 0);
678 static void __free_pages_ok(struct page *page, unsigned int order)
681 int wasMlocked = __TestClearPageMlocked(page);
683 if (!free_pages_prepare(page, order))
686 local_irq_save(flags);
687 if (unlikely(wasMlocked))
688 free_page_mlock(page);
689 __count_vm_events(PGFREE, 1 << order);
690 free_one_page(page_zone(page), page, order,
691 get_pageblock_migratetype(page));
692 local_irq_restore(flags);
696 * permit the bootmem allocator to evade page validation on high-order frees
698 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
701 __ClearPageReserved(page);
702 set_page_count(page, 0);
703 set_page_refcounted(page);
709 for (loop = 0; loop < BITS_PER_LONG; loop++) {
710 struct page *p = &page[loop];
712 if (loop + 1 < BITS_PER_LONG)
714 __ClearPageReserved(p);
715 set_page_count(p, 0);
718 set_page_refcounted(page);
719 __free_pages(page, order);
725 * The order of subdivision here is critical for the IO subsystem.
726 * Please do not alter this order without good reasons and regression
727 * testing. Specifically, as large blocks of memory are subdivided,
728 * the order in which smaller blocks are delivered depends on the order
729 * they're subdivided in this function. This is the primary factor
730 * influencing the order in which pages are delivered to the IO
731 * subsystem according to empirical testing, and this is also justified
732 * by considering the behavior of a buddy system containing a single
733 * large block of memory acted on by a series of small allocations.
734 * This behavior is a critical factor in sglist merging's success.
738 static inline void expand(struct zone *zone, struct page *page,
739 int low, int high, struct free_area *area,
742 unsigned long size = 1 << high;
748 VM_BUG_ON(bad_range(zone, &page[size]));
749 list_add(&page[size].lru, &area->free_list[migratetype]);
751 set_page_order(&page[size], high);
756 * This page is about to be returned from the page allocator
758 static inline int check_new_page(struct page *page)
760 if (unlikely(page_mapcount(page) |
761 (page->mapping != NULL) |
762 (atomic_read(&page->_count) != 0) |
763 (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
764 (mem_cgroup_bad_page_check(page)))) {
771 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
775 for (i = 0; i < (1 << order); i++) {
776 struct page *p = page + i;
777 if (unlikely(check_new_page(p)))
781 set_page_private(page, 0);
782 set_page_refcounted(page);
784 arch_alloc_page(page, order);
785 kernel_map_pages(page, 1 << order, 1);
787 if (gfp_flags & __GFP_ZERO)
788 prep_zero_page(page, order, gfp_flags);
790 if (order && (gfp_flags & __GFP_COMP))
791 prep_compound_page(page, order);
797 * Go through the free lists for the given migratetype and remove
798 * the smallest available page from the freelists
801 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
804 unsigned int current_order;
805 struct free_area * area;
808 /* Find a page of the appropriate size in the preferred list */
809 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
810 area = &(zone->free_area[current_order]);
811 if (list_empty(&area->free_list[migratetype]))
814 page = list_entry(area->free_list[migratetype].next,
816 list_del(&page->lru);
817 rmv_page_order(page);
819 expand(zone, page, order, current_order, area, migratetype);
828 * This array describes the order lists are fallen back to when
829 * the free lists for the desirable migrate type are depleted
831 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
832 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
833 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
834 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
835 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
839 * Move the free pages in a range to the free lists of the requested type.
840 * Note that start_page and end_pages are not aligned on a pageblock
841 * boundary. If alignment is required, use move_freepages_block()
843 static int move_freepages(struct zone *zone,
844 struct page *start_page, struct page *end_page,
851 #ifndef CONFIG_HOLES_IN_ZONE
853 * page_zone is not safe to call in this context when
854 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
855 * anyway as we check zone boundaries in move_freepages_block().
856 * Remove at a later date when no bug reports exist related to
857 * grouping pages by mobility
859 BUG_ON(page_zone(start_page) != page_zone(end_page));
862 for (page = start_page; page <= end_page;) {
863 /* Make sure we are not inadvertently changing nodes */
864 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
866 if (!pfn_valid_within(page_to_pfn(page))) {
871 if (!PageBuddy(page)) {
876 order = page_order(page);
877 list_move(&page->lru,
878 &zone->free_area[order].free_list[migratetype]);
880 pages_moved += 1 << order;
886 static int move_freepages_block(struct zone *zone, struct page *page,
889 unsigned long start_pfn, end_pfn;
890 struct page *start_page, *end_page;
892 start_pfn = page_to_pfn(page);
893 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
894 start_page = pfn_to_page(start_pfn);
895 end_page = start_page + pageblock_nr_pages - 1;
896 end_pfn = start_pfn + pageblock_nr_pages - 1;
898 /* Do not cross zone boundaries */
899 if (start_pfn < zone->zone_start_pfn)
901 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
904 return move_freepages(zone, start_page, end_page, migratetype);
907 static void change_pageblock_range(struct page *pageblock_page,
908 int start_order, int migratetype)
910 int nr_pageblocks = 1 << (start_order - pageblock_order);
912 while (nr_pageblocks--) {
913 set_pageblock_migratetype(pageblock_page, migratetype);
914 pageblock_page += pageblock_nr_pages;
918 /* Remove an element from the buddy allocator from the fallback list */
919 static inline struct page *
920 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
922 struct free_area * area;
927 /* Find the largest possible block of pages in the other list */
928 for (current_order = MAX_ORDER-1; current_order >= order;
930 for (i = 0; i < MIGRATE_TYPES - 1; i++) {
931 migratetype = fallbacks[start_migratetype][i];
933 /* MIGRATE_RESERVE handled later if necessary */
934 if (migratetype == MIGRATE_RESERVE)
937 area = &(zone->free_area[current_order]);
938 if (list_empty(&area->free_list[migratetype]))
941 page = list_entry(area->free_list[migratetype].next,
946 * If breaking a large block of pages, move all free
947 * pages to the preferred allocation list. If falling
948 * back for a reclaimable kernel allocation, be more
949 * aggressive about taking ownership of free pages
951 if (unlikely(current_order >= (pageblock_order >> 1)) ||
952 start_migratetype == MIGRATE_RECLAIMABLE ||
953 page_group_by_mobility_disabled) {
955 pages = move_freepages_block(zone, page,
958 /* Claim the whole block if over half of it is free */
959 if (pages >= (1 << (pageblock_order-1)) ||
960 page_group_by_mobility_disabled)
961 set_pageblock_migratetype(page,
964 migratetype = start_migratetype;
967 /* Remove the page from the freelists */
968 list_del(&page->lru);
969 rmv_page_order(page);
971 /* Take ownership for orders >= pageblock_order */
972 if (current_order >= pageblock_order)
973 change_pageblock_range(page, current_order,
976 expand(zone, page, order, current_order, area, migratetype);
978 trace_mm_page_alloc_extfrag(page, order, current_order,
979 start_migratetype, migratetype);
989 * Do the hard work of removing an element from the buddy allocator.
990 * Call me with the zone->lock already held.
992 static struct page *__rmqueue(struct zone *zone, unsigned int order,
998 page = __rmqueue_smallest(zone, order, migratetype);
1000 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1001 page = __rmqueue_fallback(zone, order, migratetype);
1004 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1005 * is used because __rmqueue_smallest is an inline function
1006 * and we want just one call site
1009 migratetype = MIGRATE_RESERVE;
1014 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1019 * Obtain a specified number of elements from the buddy allocator, all under
1020 * a single hold of the lock, for efficiency. Add them to the supplied list.
1021 * Returns the number of new pages which were placed at *list.
1023 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1024 unsigned long count, struct list_head *list,
1025 int migratetype, int cold)
1029 spin_lock(&zone->lock);
1030 for (i = 0; i < count; ++i) {
1031 struct page *page = __rmqueue(zone, order, migratetype);
1032 if (unlikely(page == NULL))
1036 * Split buddy pages returned by expand() are received here
1037 * in physical page order. The page is added to the callers and
1038 * list and the list head then moves forward. From the callers
1039 * perspective, the linked list is ordered by page number in
1040 * some conditions. This is useful for IO devices that can
1041 * merge IO requests if the physical pages are ordered
1044 if (likely(cold == 0))
1045 list_add(&page->lru, list);
1047 list_add_tail(&page->lru, list);
1048 set_page_private(page, migratetype);
1051 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1052 spin_unlock(&zone->lock);
1058 * Called from the vmstat counter updater to drain pagesets of this
1059 * currently executing processor on remote nodes after they have
1062 * Note that this function must be called with the thread pinned to
1063 * a single processor.
1065 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1067 unsigned long flags;
1070 local_irq_save(flags);
1071 if (pcp->count >= pcp->batch)
1072 to_drain = pcp->batch;
1074 to_drain = pcp->count;
1075 free_pcppages_bulk(zone, to_drain, pcp);
1076 pcp->count -= to_drain;
1077 local_irq_restore(flags);
1082 * Drain pages of the indicated processor.
1084 * The processor must either be the current processor and the
1085 * thread pinned to the current processor or a processor that
1088 static void drain_pages(unsigned int cpu)
1090 unsigned long flags;
1093 for_each_populated_zone(zone) {
1094 struct per_cpu_pageset *pset;
1095 struct per_cpu_pages *pcp;
1097 local_irq_save(flags);
1098 pset = per_cpu_ptr(zone->pageset, cpu);
1102 free_pcppages_bulk(zone, pcp->count, pcp);
1105 local_irq_restore(flags);
1110 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1112 void drain_local_pages(void *arg)
1114 drain_pages(smp_processor_id());
1118 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1120 void drain_all_pages(void)
1122 on_each_cpu(drain_local_pages, NULL, 1);
1125 #ifdef CONFIG_HIBERNATION
1127 void mark_free_pages(struct zone *zone)
1129 unsigned long pfn, max_zone_pfn;
1130 unsigned long flags;
1132 struct list_head *curr;
1134 if (!zone->spanned_pages)
1137 spin_lock_irqsave(&zone->lock, flags);
1139 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1140 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1141 if (pfn_valid(pfn)) {
1142 struct page *page = pfn_to_page(pfn);
1144 if (!swsusp_page_is_forbidden(page))
1145 swsusp_unset_page_free(page);
1148 for_each_migratetype_order(order, t) {
1149 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1152 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1153 for (i = 0; i < (1UL << order); i++)
1154 swsusp_set_page_free(pfn_to_page(pfn + i));
1157 spin_unlock_irqrestore(&zone->lock, flags);
1159 #endif /* CONFIG_PM */
1162 * Free a 0-order page
1163 * cold == 1 ? free a cold page : free a hot page
1165 void free_hot_cold_page(struct page *page, int cold)
1167 struct zone *zone = page_zone(page);
1168 struct per_cpu_pages *pcp;
1169 unsigned long flags;
1171 int wasMlocked = __TestClearPageMlocked(page);
1173 if (!free_pages_prepare(page, 0))
1176 migratetype = get_pageblock_migratetype(page);
1177 set_page_private(page, migratetype);
1178 local_irq_save(flags);
1179 if (unlikely(wasMlocked))
1180 free_page_mlock(page);
1181 __count_vm_event(PGFREE);
1184 * We only track unmovable, reclaimable and movable on pcp lists.
1185 * Free ISOLATE pages back to the allocator because they are being
1186 * offlined but treat RESERVE as movable pages so we can get those
1187 * areas back if necessary. Otherwise, we may have to free
1188 * excessively into the page allocator
1190 if (migratetype >= MIGRATE_PCPTYPES) {
1191 if (unlikely(migratetype == MIGRATE_ISOLATE)) {
1192 free_one_page(zone, page, 0, migratetype);
1195 migratetype = MIGRATE_MOVABLE;
1198 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1200 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1202 list_add(&page->lru, &pcp->lists[migratetype]);
1204 if (pcp->count >= pcp->high) {
1205 free_pcppages_bulk(zone, pcp->batch, pcp);
1206 pcp->count -= pcp->batch;
1210 local_irq_restore(flags);
1214 * split_page takes a non-compound higher-order page, and splits it into
1215 * n (1<<order) sub-pages: page[0..n]
1216 * Each sub-page must be freed individually.
1218 * Note: this is probably too low level an operation for use in drivers.
1219 * Please consult with lkml before using this in your driver.
1221 void split_page(struct page *page, unsigned int order)
1225 VM_BUG_ON(PageCompound(page));
1226 VM_BUG_ON(!page_count(page));
1228 #ifdef CONFIG_KMEMCHECK
1230 * Split shadow pages too, because free(page[0]) would
1231 * otherwise free the whole shadow.
1233 if (kmemcheck_page_is_tracked(page))
1234 split_page(virt_to_page(page[0].shadow), order);
1237 for (i = 1; i < (1 << order); i++)
1238 set_page_refcounted(page + i);
1242 * Similar to split_page except the page is already free. As this is only
1243 * being used for migration, the migratetype of the block also changes.
1244 * As this is called with interrupts disabled, the caller is responsible
1245 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1248 * Note: this is probably too low level an operation for use in drivers.
1249 * Please consult with lkml before using this in your driver.
1251 int split_free_page(struct page *page)
1254 unsigned long watermark;
1257 BUG_ON(!PageBuddy(page));
1259 zone = page_zone(page);
1260 order = page_order(page);
1262 /* Obey watermarks as if the page was being allocated */
1263 watermark = low_wmark_pages(zone) + (1 << order);
1264 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1267 /* Remove page from free list */
1268 list_del(&page->lru);
1269 zone->free_area[order].nr_free--;
1270 rmv_page_order(page);
1271 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
1273 /* Split into individual pages */
1274 set_page_refcounted(page);
1275 split_page(page, order);
1277 if (order >= pageblock_order - 1) {
1278 struct page *endpage = page + (1 << order) - 1;
1279 for (; page < endpage; page += pageblock_nr_pages)
1280 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1287 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1288 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1292 struct page *buffered_rmqueue(struct zone *preferred_zone,
1293 struct zone *zone, int order, gfp_t gfp_flags,
1296 unsigned long flags;
1298 int cold = !!(gfp_flags & __GFP_COLD);
1301 if (likely(order == 0)) {
1302 struct per_cpu_pages *pcp;
1303 struct list_head *list;
1305 local_irq_save(flags);
1306 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1307 list = &pcp->lists[migratetype];
1308 if (list_empty(list)) {
1309 pcp->count += rmqueue_bulk(zone, 0,
1312 if (unlikely(list_empty(list)))
1317 page = list_entry(list->prev, struct page, lru);
1319 page = list_entry(list->next, struct page, lru);
1321 list_del(&page->lru);
1324 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1326 * __GFP_NOFAIL is not to be used in new code.
1328 * All __GFP_NOFAIL callers should be fixed so that they
1329 * properly detect and handle allocation failures.
1331 * We most definitely don't want callers attempting to
1332 * allocate greater than order-1 page units with
1335 WARN_ON_ONCE(order > 1);
1337 spin_lock_irqsave(&zone->lock, flags);
1338 page = __rmqueue(zone, order, migratetype);
1339 spin_unlock(&zone->lock);
1342 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
1345 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1346 zone_statistics(preferred_zone, zone, gfp_flags);
1347 local_irq_restore(flags);
1349 VM_BUG_ON(bad_range(zone, page));
1350 if (prep_new_page(page, order, gfp_flags))
1355 local_irq_restore(flags);
1359 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1360 #define ALLOC_WMARK_MIN WMARK_MIN
1361 #define ALLOC_WMARK_LOW WMARK_LOW
1362 #define ALLOC_WMARK_HIGH WMARK_HIGH
1363 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1365 /* Mask to get the watermark bits */
1366 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1368 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1369 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1370 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1372 #ifdef CONFIG_FAIL_PAGE_ALLOC
1375 struct fault_attr attr;
1377 u32 ignore_gfp_highmem;
1378 u32 ignore_gfp_wait;
1380 } fail_page_alloc = {
1381 .attr = FAULT_ATTR_INITIALIZER,
1382 .ignore_gfp_wait = 1,
1383 .ignore_gfp_highmem = 1,
1387 static int __init setup_fail_page_alloc(char *str)
1389 return setup_fault_attr(&fail_page_alloc.attr, str);
1391 __setup("fail_page_alloc=", setup_fail_page_alloc);
1393 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1395 if (order < fail_page_alloc.min_order)
1397 if (gfp_mask & __GFP_NOFAIL)
1399 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1401 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1404 return should_fail(&fail_page_alloc.attr, 1 << order);
1407 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1409 static int __init fail_page_alloc_debugfs(void)
1411 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1414 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1415 &fail_page_alloc.attr);
1417 return PTR_ERR(dir);
1419 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1420 &fail_page_alloc.ignore_gfp_wait))
1422 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1423 &fail_page_alloc.ignore_gfp_highmem))
1425 if (!debugfs_create_u32("min-order", mode, dir,
1426 &fail_page_alloc.min_order))
1431 debugfs_remove_recursive(dir);
1436 late_initcall(fail_page_alloc_debugfs);
1438 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1440 #else /* CONFIG_FAIL_PAGE_ALLOC */
1442 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1447 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1450 * Return true if free pages are above 'mark'. This takes into account the order
1451 * of the allocation.
1453 static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1454 int classzone_idx, int alloc_flags, long free_pages)
1456 /* free_pages my go negative - that's OK */
1460 free_pages -= (1 << order) + 1;
1461 if (alloc_flags & ALLOC_HIGH)
1463 if (alloc_flags & ALLOC_HARDER)
1466 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1468 for (o = 0; o < order; o++) {
1469 /* At the next order, this order's pages become unavailable */
1470 free_pages -= z->free_area[o].nr_free << o;
1472 /* Require fewer higher order pages to be free */
1475 if (free_pages <= min)
1481 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1482 int classzone_idx, int alloc_flags)
1484 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1485 zone_page_state(z, NR_FREE_PAGES));
1488 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
1489 int classzone_idx, int alloc_flags)
1491 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1493 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1494 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1496 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1502 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1503 * skip over zones that are not allowed by the cpuset, or that have
1504 * been recently (in last second) found to be nearly full. See further
1505 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1506 * that have to skip over a lot of full or unallowed zones.
1508 * If the zonelist cache is present in the passed in zonelist, then
1509 * returns a pointer to the allowed node mask (either the current
1510 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1512 * If the zonelist cache is not available for this zonelist, does
1513 * nothing and returns NULL.
1515 * If the fullzones BITMAP in the zonelist cache is stale (more than
1516 * a second since last zap'd) then we zap it out (clear its bits.)
1518 * We hold off even calling zlc_setup, until after we've checked the
1519 * first zone in the zonelist, on the theory that most allocations will
1520 * be satisfied from that first zone, so best to examine that zone as
1521 * quickly as we can.
1523 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1525 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1526 nodemask_t *allowednodes; /* zonelist_cache approximation */
1528 zlc = zonelist->zlcache_ptr;
1532 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1533 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1534 zlc->last_full_zap = jiffies;
1537 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1538 &cpuset_current_mems_allowed :
1539 &node_states[N_HIGH_MEMORY];
1540 return allowednodes;
1544 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1545 * if it is worth looking at further for free memory:
1546 * 1) Check that the zone isn't thought to be full (doesn't have its
1547 * bit set in the zonelist_cache fullzones BITMAP).
1548 * 2) Check that the zones node (obtained from the zonelist_cache
1549 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1550 * Return true (non-zero) if zone is worth looking at further, or
1551 * else return false (zero) if it is not.
1553 * This check -ignores- the distinction between various watermarks,
1554 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1555 * found to be full for any variation of these watermarks, it will
1556 * be considered full for up to one second by all requests, unless
1557 * we are so low on memory on all allowed nodes that we are forced
1558 * into the second scan of the zonelist.
1560 * In the second scan we ignore this zonelist cache and exactly
1561 * apply the watermarks to all zones, even it is slower to do so.
1562 * We are low on memory in the second scan, and should leave no stone
1563 * unturned looking for a free page.
1565 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1566 nodemask_t *allowednodes)
1568 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1569 int i; /* index of *z in zonelist zones */
1570 int n; /* node that zone *z is on */
1572 zlc = zonelist->zlcache_ptr;
1576 i = z - zonelist->_zonerefs;
1579 /* This zone is worth trying if it is allowed but not full */
1580 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1584 * Given 'z' scanning a zonelist, set the corresponding bit in
1585 * zlc->fullzones, so that subsequent attempts to allocate a page
1586 * from that zone don't waste time re-examining it.
1588 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1590 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1591 int i; /* index of *z in zonelist zones */
1593 zlc = zonelist->zlcache_ptr;
1597 i = z - zonelist->_zonerefs;
1599 set_bit(i, zlc->fullzones);
1603 * clear all zones full, called after direct reclaim makes progress so that
1604 * a zone that was recently full is not skipped over for up to a second
1606 static void zlc_clear_zones_full(struct zonelist *zonelist)
1608 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1610 zlc = zonelist->zlcache_ptr;
1614 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1617 #else /* CONFIG_NUMA */
1619 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1624 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1625 nodemask_t *allowednodes)
1630 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1634 static void zlc_clear_zones_full(struct zonelist *zonelist)
1637 #endif /* CONFIG_NUMA */
1640 * get_page_from_freelist goes through the zonelist trying to allocate
1643 static struct page *
1644 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1645 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1646 struct zone *preferred_zone, int migratetype)
1649 struct page *page = NULL;
1652 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1653 int zlc_active = 0; /* set if using zonelist_cache */
1654 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1656 classzone_idx = zone_idx(preferred_zone);
1659 * Scan zonelist, looking for a zone with enough free.
1660 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1662 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1663 high_zoneidx, nodemask) {
1664 if (NUMA_BUILD && zlc_active &&
1665 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1667 if ((alloc_flags & ALLOC_CPUSET) &&
1668 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1671 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1672 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1676 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1677 if (zone_watermark_ok(zone, order, mark,
1678 classzone_idx, alloc_flags))
1681 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1683 * we do zlc_setup if there are multiple nodes
1684 * and before considering the first zone allowed
1687 allowednodes = zlc_setup(zonelist, alloc_flags);
1692 if (zone_reclaim_mode == 0)
1693 goto this_zone_full;
1696 * As we may have just activated ZLC, check if the first
1697 * eligible zone has failed zone_reclaim recently.
1699 if (NUMA_BUILD && zlc_active &&
1700 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1703 ret = zone_reclaim(zone, gfp_mask, order);
1705 case ZONE_RECLAIM_NOSCAN:
1708 case ZONE_RECLAIM_FULL:
1709 /* scanned but unreclaimable */
1712 /* did we reclaim enough */
1713 if (!zone_watermark_ok(zone, order, mark,
1714 classzone_idx, alloc_flags))
1715 goto this_zone_full;
1720 page = buffered_rmqueue(preferred_zone, zone, order,
1721 gfp_mask, migratetype);
1726 zlc_mark_zone_full(zonelist, z);
1729 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1730 /* Disable zlc cache for second zonelist scan */
1738 * Large machines with many possible nodes should not always dump per-node
1739 * meminfo in irq context.
1741 static inline bool should_suppress_show_mem(void)
1746 ret = in_interrupt();
1751 static DEFINE_RATELIMIT_STATE(nopage_rs,
1752 DEFAULT_RATELIMIT_INTERVAL,
1753 DEFAULT_RATELIMIT_BURST);
1755 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
1757 unsigned int filter = SHOW_MEM_FILTER_NODES;
1759 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
1763 * This documents exceptions given to allocations in certain
1764 * contexts that are allowed to allocate outside current's set
1767 if (!(gfp_mask & __GFP_NOMEMALLOC))
1768 if (test_thread_flag(TIF_MEMDIE) ||
1769 (current->flags & (PF_MEMALLOC | PF_EXITING)))
1770 filter &= ~SHOW_MEM_FILTER_NODES;
1771 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
1772 filter &= ~SHOW_MEM_FILTER_NODES;
1775 struct va_format vaf;
1778 va_start(args, fmt);
1783 pr_warn("%pV", &vaf);
1788 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
1789 current->comm, order, gfp_mask);
1792 if (!should_suppress_show_mem())
1797 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
1798 unsigned long pages_reclaimed)
1800 /* Do not loop if specifically requested */
1801 if (gfp_mask & __GFP_NORETRY)
1805 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1806 * means __GFP_NOFAIL, but that may not be true in other
1809 if (order <= PAGE_ALLOC_COSTLY_ORDER)
1813 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1814 * specified, then we retry until we no longer reclaim any pages
1815 * (above), or we've reclaimed an order of pages at least as
1816 * large as the allocation's order. In both cases, if the
1817 * allocation still fails, we stop retrying.
1819 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
1823 * Don't let big-order allocations loop unless the caller
1824 * explicitly requests that.
1826 if (gfp_mask & __GFP_NOFAIL)
1832 static inline struct page *
1833 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
1834 struct zonelist *zonelist, enum zone_type high_zoneidx,
1835 nodemask_t *nodemask, struct zone *preferred_zone,
1840 /* Acquire the OOM killer lock for the zones in zonelist */
1841 if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
1842 schedule_timeout_uninterruptible(1);
1847 * Go through the zonelist yet one more time, keep very high watermark
1848 * here, this is only to catch a parallel oom killing, we must fail if
1849 * we're still under heavy pressure.
1851 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
1852 order, zonelist, high_zoneidx,
1853 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1854 preferred_zone, migratetype);
1858 if (!(gfp_mask & __GFP_NOFAIL)) {
1859 /* The OOM killer will not help higher order allocs */
1860 if (order > PAGE_ALLOC_COSTLY_ORDER)
1862 /* The OOM killer does not needlessly kill tasks for lowmem */
1863 if (high_zoneidx < ZONE_NORMAL)
1866 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1867 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1868 * The caller should handle page allocation failure by itself if
1869 * it specifies __GFP_THISNODE.
1870 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1872 if (gfp_mask & __GFP_THISNODE)
1875 /* Exhausted what can be done so it's blamo time */
1876 out_of_memory(zonelist, gfp_mask, order, nodemask);
1879 clear_zonelist_oom(zonelist, gfp_mask);
1883 #ifdef CONFIG_COMPACTION
1884 /* Try memory compaction for high-order allocations before reclaim */
1885 static struct page *
1886 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
1887 struct zonelist *zonelist, enum zone_type high_zoneidx,
1888 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1889 int migratetype, bool sync_migration,
1890 bool *deferred_compaction,
1891 unsigned long *did_some_progress)
1898 if (compaction_deferred(preferred_zone)) {
1899 *deferred_compaction = true;
1903 current->flags |= PF_MEMALLOC;
1904 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
1905 nodemask, sync_migration);
1906 current->flags &= ~PF_MEMALLOC;
1907 if (*did_some_progress != COMPACT_SKIPPED) {
1909 /* Page migration frees to the PCP lists but we want merging */
1910 drain_pages(get_cpu());
1913 page = get_page_from_freelist(gfp_mask, nodemask,
1914 order, zonelist, high_zoneidx,
1915 alloc_flags, preferred_zone,
1918 preferred_zone->compact_considered = 0;
1919 preferred_zone->compact_defer_shift = 0;
1920 count_vm_event(COMPACTSUCCESS);
1925 * It's bad if compaction run occurs and fails.
1926 * The most likely reason is that pages exist,
1927 * but not enough to satisfy watermarks.
1929 count_vm_event(COMPACTFAIL);
1932 * As async compaction considers a subset of pageblocks, only
1933 * defer if the failure was a sync compaction failure.
1936 defer_compaction(preferred_zone);
1944 static inline struct page *
1945 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
1946 struct zonelist *zonelist, enum zone_type high_zoneidx,
1947 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1948 int migratetype, bool sync_migration,
1949 bool *deferred_compaction,
1950 unsigned long *did_some_progress)
1954 #endif /* CONFIG_COMPACTION */
1956 /* The really slow allocator path where we enter direct reclaim */
1957 static inline struct page *
1958 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
1959 struct zonelist *zonelist, enum zone_type high_zoneidx,
1960 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1961 int migratetype, unsigned long *did_some_progress)
1963 struct page *page = NULL;
1964 struct reclaim_state reclaim_state;
1965 bool drained = false;
1969 /* We now go into synchronous reclaim */
1970 cpuset_memory_pressure_bump();
1971 current->flags |= PF_MEMALLOC;
1972 lockdep_set_current_reclaim_state(gfp_mask);
1973 reclaim_state.reclaimed_slab = 0;
1974 current->reclaim_state = &reclaim_state;
1976 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
1978 current->reclaim_state = NULL;
1979 lockdep_clear_current_reclaim_state();
1980 current->flags &= ~PF_MEMALLOC;
1984 if (unlikely(!(*did_some_progress)))
1987 /* After successful reclaim, reconsider all zones for allocation */
1989 zlc_clear_zones_full(zonelist);
1992 page = get_page_from_freelist(gfp_mask, nodemask, order,
1993 zonelist, high_zoneidx,
1994 alloc_flags, preferred_zone,
1998 * If an allocation failed after direct reclaim, it could be because
1999 * pages are pinned on the per-cpu lists. Drain them and try again
2001 if (!page && !drained) {
2011 * This is called in the allocator slow-path if the allocation request is of
2012 * sufficient urgency to ignore watermarks and take other desperate measures
2014 static inline struct page *
2015 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2016 struct zonelist *zonelist, enum zone_type high_zoneidx,
2017 nodemask_t *nodemask, struct zone *preferred_zone,
2023 page = get_page_from_freelist(gfp_mask, nodemask, order,
2024 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2025 preferred_zone, migratetype);
2027 if (!page && gfp_mask & __GFP_NOFAIL)
2028 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2029 } while (!page && (gfp_mask & __GFP_NOFAIL));
2035 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2036 enum zone_type high_zoneidx,
2037 enum zone_type classzone_idx)
2042 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2043 wakeup_kswapd(zone, order, classzone_idx);
2047 gfp_to_alloc_flags(gfp_t gfp_mask)
2049 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2050 const gfp_t wait = gfp_mask & __GFP_WAIT;
2052 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2053 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2056 * The caller may dip into page reserves a bit more if the caller
2057 * cannot run direct reclaim, or if the caller has realtime scheduling
2058 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2059 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2061 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2065 * Not worth trying to allocate harder for
2066 * __GFP_NOMEMALLOC even if it can't schedule.
2068 if (!(gfp_mask & __GFP_NOMEMALLOC))
2069 alloc_flags |= ALLOC_HARDER;
2071 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2072 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2074 alloc_flags &= ~ALLOC_CPUSET;
2075 } else if (unlikely(rt_task(current)) && !in_interrupt())
2076 alloc_flags |= ALLOC_HARDER;
2078 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2079 if (!in_interrupt() &&
2080 ((current->flags & PF_MEMALLOC) ||
2081 unlikely(test_thread_flag(TIF_MEMDIE))))
2082 alloc_flags |= ALLOC_NO_WATERMARKS;
2088 static inline struct page *
2089 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2090 struct zonelist *zonelist, enum zone_type high_zoneidx,
2091 nodemask_t *nodemask, struct zone *preferred_zone,
2094 const gfp_t wait = gfp_mask & __GFP_WAIT;
2095 struct page *page = NULL;
2097 unsigned long pages_reclaimed = 0;
2098 unsigned long did_some_progress;
2099 bool sync_migration = false;
2100 bool deferred_compaction = false;
2103 * In the slowpath, we sanity check order to avoid ever trying to
2104 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2105 * be using allocators in order of preference for an area that is
2108 if (order >= MAX_ORDER) {
2109 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2114 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2115 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2116 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2117 * using a larger set of nodes after it has established that the
2118 * allowed per node queues are empty and that nodes are
2121 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2125 if (!(gfp_mask & __GFP_NO_KSWAPD))
2126 wake_all_kswapd(order, zonelist, high_zoneidx,
2127 zone_idx(preferred_zone));
2130 * OK, we're below the kswapd watermark and have kicked background
2131 * reclaim. Now things get more complex, so set up alloc_flags according
2132 * to how we want to proceed.
2134 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2137 * Find the true preferred zone if the allocation is unconstrained by
2140 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
2141 first_zones_zonelist(zonelist, high_zoneidx, NULL,
2145 /* This is the last chance, in general, before the goto nopage. */
2146 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2147 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2148 preferred_zone, migratetype);
2152 /* Allocate without watermarks if the context allows */
2153 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2154 page = __alloc_pages_high_priority(gfp_mask, order,
2155 zonelist, high_zoneidx, nodemask,
2156 preferred_zone, migratetype);
2161 /* Atomic allocations - we can't balance anything */
2165 /* Avoid recursion of direct reclaim */
2166 if (current->flags & PF_MEMALLOC)
2169 /* Avoid allocations with no watermarks from looping endlessly */
2170 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2174 * Try direct compaction. The first pass is asynchronous. Subsequent
2175 * attempts after direct reclaim are synchronous
2177 page = __alloc_pages_direct_compact(gfp_mask, order,
2178 zonelist, high_zoneidx,
2180 alloc_flags, preferred_zone,
2181 migratetype, sync_migration,
2182 &deferred_compaction,
2183 &did_some_progress);
2186 sync_migration = true;
2189 * If compaction is deferred for high-order allocations, it is because
2190 * sync compaction recently failed. In this is the case and the caller
2191 * has requested the system not be heavily disrupted, fail the
2192 * allocation now instead of entering direct reclaim
2194 if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
2197 /* Try direct reclaim and then allocating */
2198 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2199 zonelist, high_zoneidx,
2201 alloc_flags, preferred_zone,
2202 migratetype, &did_some_progress);
2207 * If we failed to make any progress reclaiming, then we are
2208 * running out of options and have to consider going OOM
2210 if (!did_some_progress) {
2211 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2212 if (oom_killer_disabled)
2214 page = __alloc_pages_may_oom(gfp_mask, order,
2215 zonelist, high_zoneidx,
2216 nodemask, preferred_zone,
2221 if (!(gfp_mask & __GFP_NOFAIL)) {
2223 * The oom killer is not called for high-order
2224 * allocations that may fail, so if no progress
2225 * is being made, there are no other options and
2226 * retrying is unlikely to help.
2228 if (order > PAGE_ALLOC_COSTLY_ORDER)
2231 * The oom killer is not called for lowmem
2232 * allocations to prevent needlessly killing
2235 if (high_zoneidx < ZONE_NORMAL)
2243 /* Check if we should retry the allocation */
2244 pages_reclaimed += did_some_progress;
2245 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
2246 /* Wait for some write requests to complete then retry */
2247 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2251 * High-order allocations do not necessarily loop after
2252 * direct reclaim and reclaim/compaction depends on compaction
2253 * being called after reclaim so call directly if necessary
2255 page = __alloc_pages_direct_compact(gfp_mask, order,
2256 zonelist, high_zoneidx,
2258 alloc_flags, preferred_zone,
2259 migratetype, sync_migration,
2260 &deferred_compaction,
2261 &did_some_progress);
2267 warn_alloc_failed(gfp_mask, order, NULL);
2270 if (kmemcheck_enabled)
2271 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2277 * This is the 'heart' of the zoned buddy allocator.
2280 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2281 struct zonelist *zonelist, nodemask_t *nodemask)
2283 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2284 struct zone *preferred_zone;
2285 struct page *page = NULL;
2286 int migratetype = allocflags_to_migratetype(gfp_mask);
2287 unsigned int cpuset_mems_cookie;
2289 gfp_mask &= gfp_allowed_mask;
2291 lockdep_trace_alloc(gfp_mask);
2293 might_sleep_if(gfp_mask & __GFP_WAIT);
2295 if (should_fail_alloc_page(gfp_mask, order))
2299 * Check the zones suitable for the gfp_mask contain at least one
2300 * valid zone. It's possible to have an empty zonelist as a result
2301 * of GFP_THISNODE and a memoryless node
2303 if (unlikely(!zonelist->_zonerefs->zone))
2307 cpuset_mems_cookie = get_mems_allowed();
2309 /* The preferred zone is used for statistics later */
2310 first_zones_zonelist(zonelist, high_zoneidx,
2311 nodemask ? : &cpuset_current_mems_allowed,
2313 if (!preferred_zone)
2316 /* First allocation attempt */
2317 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2318 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
2319 preferred_zone, migratetype);
2320 if (unlikely(!page))
2321 page = __alloc_pages_slowpath(gfp_mask, order,
2322 zonelist, high_zoneidx, nodemask,
2323 preferred_zone, migratetype);
2325 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2329 * When updating a task's mems_allowed, it is possible to race with
2330 * parallel threads in such a way that an allocation can fail while
2331 * the mask is being updated. If a page allocation is about to fail,
2332 * check if the cpuset changed during allocation and if so, retry.
2334 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
2339 EXPORT_SYMBOL(__alloc_pages_nodemask);
2342 * Common helper functions.
2344 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2349 * __get_free_pages() returns a 32-bit address, which cannot represent
2352 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2354 page = alloc_pages(gfp_mask, order);
2357 return (unsigned long) page_address(page);
2359 EXPORT_SYMBOL(__get_free_pages);
2361 unsigned long get_zeroed_page(gfp_t gfp_mask)
2363 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2365 EXPORT_SYMBOL(get_zeroed_page);
2367 void __pagevec_free(struct pagevec *pvec)
2369 int i = pagevec_count(pvec);
2372 trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
2373 free_hot_cold_page(pvec->pages[i], pvec->cold);
2377 void __free_pages(struct page *page, unsigned int order)
2379 if (put_page_testzero(page)) {
2381 free_hot_cold_page(page, 0);
2383 __free_pages_ok(page, order);
2387 EXPORT_SYMBOL(__free_pages);
2389 void free_pages(unsigned long addr, unsigned int order)
2392 VM_BUG_ON(!virt_addr_valid((void *)addr));
2393 __free_pages(virt_to_page((void *)addr), order);
2397 EXPORT_SYMBOL(free_pages);
2399 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2402 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2403 unsigned long used = addr + PAGE_ALIGN(size);
2405 split_page(virt_to_page((void *)addr), order);
2406 while (used < alloc_end) {
2411 return (void *)addr;
2415 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2416 * @size: the number of bytes to allocate
2417 * @gfp_mask: GFP flags for the allocation
2419 * This function is similar to alloc_pages(), except that it allocates the
2420 * minimum number of pages to satisfy the request. alloc_pages() can only
2421 * allocate memory in power-of-two pages.
2423 * This function is also limited by MAX_ORDER.
2425 * Memory allocated by this function must be released by free_pages_exact().
2427 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2429 unsigned int order = get_order(size);
2432 addr = __get_free_pages(gfp_mask, order);
2433 return make_alloc_exact(addr, order, size);
2435 EXPORT_SYMBOL(alloc_pages_exact);
2438 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2440 * @nid: the preferred node ID where memory should be allocated
2441 * @size: the number of bytes to allocate
2442 * @gfp_mask: GFP flags for the allocation
2444 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2446 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2449 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2451 unsigned order = get_order(size);
2452 struct page *p = alloc_pages_node(nid, gfp_mask, order);
2455 return make_alloc_exact((unsigned long)page_address(p), order, size);
2457 EXPORT_SYMBOL(alloc_pages_exact_nid);
2460 * free_pages_exact - release memory allocated via alloc_pages_exact()
2461 * @virt: the value returned by alloc_pages_exact.
2462 * @size: size of allocation, same value as passed to alloc_pages_exact().
2464 * Release the memory allocated by a previous call to alloc_pages_exact.
2466 void free_pages_exact(void *virt, size_t size)
2468 unsigned long addr = (unsigned long)virt;
2469 unsigned long end = addr + PAGE_ALIGN(size);
2471 while (addr < end) {
2476 EXPORT_SYMBOL(free_pages_exact);
2478 static unsigned int nr_free_zone_pages(int offset)
2483 /* Just pick one node, since fallback list is circular */
2484 unsigned int sum = 0;
2486 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2488 for_each_zone_zonelist(zone, z, zonelist, offset) {
2489 unsigned long size = zone->present_pages;
2490 unsigned long high = high_wmark_pages(zone);
2499 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2501 unsigned int nr_free_buffer_pages(void)
2503 return nr_free_zone_pages(gfp_zone(GFP_USER));
2505 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
2508 * Amount of free RAM allocatable within all zones
2510 unsigned int nr_free_pagecache_pages(void)
2512 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2515 static inline void show_node(struct zone *zone)
2518 printk("Node %d ", zone_to_nid(zone));
2521 void si_meminfo(struct sysinfo *val)
2523 val->totalram = totalram_pages;
2525 val->freeram = global_page_state(NR_FREE_PAGES);
2526 val->bufferram = nr_blockdev_pages();
2527 val->totalhigh = totalhigh_pages;
2528 val->freehigh = nr_free_highpages();
2529 val->mem_unit = PAGE_SIZE;
2532 EXPORT_SYMBOL(si_meminfo);
2535 void si_meminfo_node(struct sysinfo *val, int nid)
2537 pg_data_t *pgdat = NODE_DATA(nid);
2539 val->totalram = pgdat->node_present_pages;
2540 val->freeram = node_page_state(nid, NR_FREE_PAGES);
2541 #ifdef CONFIG_HIGHMEM
2542 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2543 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2549 val->mem_unit = PAGE_SIZE;
2554 * Determine whether the node should be displayed or not, depending on whether
2555 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2557 bool skip_free_areas_node(unsigned int flags, int nid)
2560 unsigned int cpuset_mems_cookie;
2562 if (!(flags & SHOW_MEM_FILTER_NODES))
2566 cpuset_mems_cookie = get_mems_allowed();
2567 ret = !node_isset(nid, cpuset_current_mems_allowed);
2568 } while (!put_mems_allowed(cpuset_mems_cookie));
2573 #define K(x) ((x) << (PAGE_SHIFT-10))
2576 * Show free area list (used inside shift_scroll-lock stuff)
2577 * We also calculate the percentage fragmentation. We do this by counting the
2578 * memory on each free list with the exception of the first item on the list.
2579 * Suppresses nodes that are not allowed by current's cpuset if
2580 * SHOW_MEM_FILTER_NODES is passed.
2582 void show_free_areas(unsigned int filter)
2587 for_each_populated_zone(zone) {
2588 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2591 printk("%s per-cpu:\n", zone->name);
2593 for_each_online_cpu(cpu) {
2594 struct per_cpu_pageset *pageset;
2596 pageset = per_cpu_ptr(zone->pageset, cpu);
2598 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2599 cpu, pageset->pcp.high,
2600 pageset->pcp.batch, pageset->pcp.count);
2604 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2605 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2607 " dirty:%lu writeback:%lu unstable:%lu\n"
2608 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2609 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2610 global_page_state(NR_ACTIVE_ANON),
2611 global_page_state(NR_INACTIVE_ANON),
2612 global_page_state(NR_ISOLATED_ANON),
2613 global_page_state(NR_ACTIVE_FILE),
2614 global_page_state(NR_INACTIVE_FILE),
2615 global_page_state(NR_ISOLATED_FILE),
2616 global_page_state(NR_UNEVICTABLE),
2617 global_page_state(NR_FILE_DIRTY),
2618 global_page_state(NR_WRITEBACK),
2619 global_page_state(NR_UNSTABLE_NFS),
2620 global_page_state(NR_FREE_PAGES),
2621 global_page_state(NR_SLAB_RECLAIMABLE),
2622 global_page_state(NR_SLAB_UNRECLAIMABLE),
2623 global_page_state(NR_FILE_MAPPED),
2624 global_page_state(NR_SHMEM),
2625 global_page_state(NR_PAGETABLE),
2626 global_page_state(NR_BOUNCE));
2628 for_each_populated_zone(zone) {
2631 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2639 " active_anon:%lukB"
2640 " inactive_anon:%lukB"
2641 " active_file:%lukB"
2642 " inactive_file:%lukB"
2643 " unevictable:%lukB"
2644 " isolated(anon):%lukB"
2645 " isolated(file):%lukB"
2652 " slab_reclaimable:%lukB"
2653 " slab_unreclaimable:%lukB"
2654 " kernel_stack:%lukB"
2658 " writeback_tmp:%lukB"
2659 " pages_scanned:%lu"
2660 " all_unreclaimable? %s"
2663 K(zone_page_state(zone, NR_FREE_PAGES)),
2664 K(min_wmark_pages(zone)),
2665 K(low_wmark_pages(zone)),
2666 K(high_wmark_pages(zone)),
2667 K(zone_page_state(zone, NR_ACTIVE_ANON)),
2668 K(zone_page_state(zone, NR_INACTIVE_ANON)),
2669 K(zone_page_state(zone, NR_ACTIVE_FILE)),
2670 K(zone_page_state(zone, NR_INACTIVE_FILE)),
2671 K(zone_page_state(zone, NR_UNEVICTABLE)),
2672 K(zone_page_state(zone, NR_ISOLATED_ANON)),
2673 K(zone_page_state(zone, NR_ISOLATED_FILE)),
2674 K(zone->present_pages),
2675 K(zone_page_state(zone, NR_MLOCK)),
2676 K(zone_page_state(zone, NR_FILE_DIRTY)),
2677 K(zone_page_state(zone, NR_WRITEBACK)),
2678 K(zone_page_state(zone, NR_FILE_MAPPED)),
2679 K(zone_page_state(zone, NR_SHMEM)),
2680 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
2681 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2682 zone_page_state(zone, NR_KERNEL_STACK) *
2684 K(zone_page_state(zone, NR_PAGETABLE)),
2685 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
2686 K(zone_page_state(zone, NR_BOUNCE)),
2687 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
2688 zone->pages_scanned,
2689 (zone->all_unreclaimable ? "yes" : "no")
2691 printk("lowmem_reserve[]:");
2692 for (i = 0; i < MAX_NR_ZONES; i++)
2693 printk(" %lu", zone->lowmem_reserve[i]);
2697 for_each_populated_zone(zone) {
2698 unsigned long nr[MAX_ORDER], flags, order, total = 0;
2700 if (skip_free_areas_node(filter, zone_to_nid(zone)))
2703 printk("%s: ", zone->name);
2705 spin_lock_irqsave(&zone->lock, flags);
2706 for (order = 0; order < MAX_ORDER; order++) {
2707 nr[order] = zone->free_area[order].nr_free;
2708 total += nr[order] << order;
2710 spin_unlock_irqrestore(&zone->lock, flags);
2711 for (order = 0; order < MAX_ORDER; order++)
2712 printk("%lu*%lukB ", nr[order], K(1UL) << order);
2713 printk("= %lukB\n", K(total));
2716 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
2718 show_swap_cache_info();
2721 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
2723 zoneref->zone = zone;
2724 zoneref->zone_idx = zone_idx(zone);
2728 * Builds allocation fallback zone lists.
2730 * Add all populated zones of a node to the zonelist.
2732 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
2733 int nr_zones, enum zone_type zone_type)
2737 BUG_ON(zone_type >= MAX_NR_ZONES);
2742 zone = pgdat->node_zones + zone_type;
2743 if (populated_zone(zone)) {
2744 zoneref_set_zone(zone,
2745 &zonelist->_zonerefs[nr_zones++]);
2746 check_highest_zone(zone_type);
2749 } while (zone_type);
2756 * 0 = automatic detection of better ordering.
2757 * 1 = order by ([node] distance, -zonetype)
2758 * 2 = order by (-zonetype, [node] distance)
2760 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2761 * the same zonelist. So only NUMA can configure this param.
2763 #define ZONELIST_ORDER_DEFAULT 0
2764 #define ZONELIST_ORDER_NODE 1
2765 #define ZONELIST_ORDER_ZONE 2
2767 /* zonelist order in the kernel.
2768 * set_zonelist_order() will set this to NODE or ZONE.
2770 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
2771 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
2775 /* The value user specified ....changed by config */
2776 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2777 /* string for sysctl */
2778 #define NUMA_ZONELIST_ORDER_LEN 16
2779 char numa_zonelist_order[16] = "default";
2782 * interface for configure zonelist ordering.
2783 * command line option "numa_zonelist_order"
2784 * = "[dD]efault - default, automatic configuration.
2785 * = "[nN]ode - order by node locality, then by zone within node
2786 * = "[zZ]one - order by zone, then by locality within zone
2789 static int __parse_numa_zonelist_order(char *s)
2791 if (*s == 'd' || *s == 'D') {
2792 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
2793 } else if (*s == 'n' || *s == 'N') {
2794 user_zonelist_order = ZONELIST_ORDER_NODE;
2795 } else if (*s == 'z' || *s == 'Z') {
2796 user_zonelist_order = ZONELIST_ORDER_ZONE;
2799 "Ignoring invalid numa_zonelist_order value: "
2806 static __init int setup_numa_zonelist_order(char *s)
2813 ret = __parse_numa_zonelist_order(s);
2815 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
2819 early_param("numa_zonelist_order", setup_numa_zonelist_order);
2822 * sysctl handler for numa_zonelist_order
2824 int numa_zonelist_order_handler(ctl_table *table, int write,
2825 void __user *buffer, size_t *length,
2828 char saved_string[NUMA_ZONELIST_ORDER_LEN];
2830 static DEFINE_MUTEX(zl_order_mutex);
2832 mutex_lock(&zl_order_mutex);
2834 strcpy(saved_string, (char*)table->data);
2835 ret = proc_dostring(table, write, buffer, length, ppos);
2839 int oldval = user_zonelist_order;
2840 if (__parse_numa_zonelist_order((char*)table->data)) {
2842 * bogus value. restore saved string
2844 strncpy((char*)table->data, saved_string,
2845 NUMA_ZONELIST_ORDER_LEN);
2846 user_zonelist_order = oldval;
2847 } else if (oldval != user_zonelist_order) {
2848 mutex_lock(&zonelists_mutex);
2849 build_all_zonelists(NULL);
2850 mutex_unlock(&zonelists_mutex);
2854 mutex_unlock(&zl_order_mutex);
2859 #define MAX_NODE_LOAD (nr_online_nodes)
2860 static int node_load[MAX_NUMNODES];
2863 * find_next_best_node - find the next node that should appear in a given node's fallback list
2864 * @node: node whose fallback list we're appending
2865 * @used_node_mask: nodemask_t of already used nodes
2867 * We use a number of factors to determine which is the next node that should
2868 * appear on a given node's fallback list. The node should not have appeared
2869 * already in @node's fallback list, and it should be the next closest node
2870 * according to the distance array (which contains arbitrary distance values
2871 * from each node to each node in the system), and should also prefer nodes
2872 * with no CPUs, since presumably they'll have very little allocation pressure
2873 * on them otherwise.
2874 * It returns -1 if no node is found.
2876 static int find_next_best_node(int node, nodemask_t *used_node_mask)
2879 int min_val = INT_MAX;
2881 const struct cpumask *tmp = cpumask_of_node(0);
2883 /* Use the local node if we haven't already */
2884 if (!node_isset(node, *used_node_mask)) {
2885 node_set(node, *used_node_mask);
2889 for_each_node_state(n, N_HIGH_MEMORY) {
2891 /* Don't want a node to appear more than once */
2892 if (node_isset(n, *used_node_mask))
2895 /* Use the distance array to find the distance */
2896 val = node_distance(node, n);
2898 /* Penalize nodes under us ("prefer the next node") */
2901 /* Give preference to headless and unused nodes */
2902 tmp = cpumask_of_node(n);
2903 if (!cpumask_empty(tmp))
2904 val += PENALTY_FOR_NODE_WITH_CPUS;
2906 /* Slight preference for less loaded node */
2907 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2908 val += node_load[n];
2910 if (val < min_val) {
2917 node_set(best_node, *used_node_mask);
2924 * Build zonelists ordered by node and zones within node.
2925 * This results in maximum locality--normal zone overflows into local
2926 * DMA zone, if any--but risks exhausting DMA zone.
2928 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2931 struct zonelist *zonelist;
2933 zonelist = &pgdat->node_zonelists[0];
2934 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2936 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2938 zonelist->_zonerefs[j].zone = NULL;
2939 zonelist->_zonerefs[j].zone_idx = 0;
2943 * Build gfp_thisnode zonelists
2945 static void build_thisnode_zonelists(pg_data_t *pgdat)
2948 struct zonelist *zonelist;
2950 zonelist = &pgdat->node_zonelists[1];
2951 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2952 zonelist->_zonerefs[j].zone = NULL;
2953 zonelist->_zonerefs[j].zone_idx = 0;
2957 * Build zonelists ordered by zone and nodes within zones.
2958 * This results in conserving DMA zone[s] until all Normal memory is
2959 * exhausted, but results in overflowing to remote node while memory
2960 * may still exist in local DMA zone.
2962 static int node_order[MAX_NUMNODES];
2964 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2967 int zone_type; /* needs to be signed */
2969 struct zonelist *zonelist;
2971 zonelist = &pgdat->node_zonelists[0];
2973 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
2974 for (j = 0; j < nr_nodes; j++) {
2975 node = node_order[j];
2976 z = &NODE_DATA(node)->node_zones[zone_type];
2977 if (populated_zone(z)) {
2979 &zonelist->_zonerefs[pos++]);
2980 check_highest_zone(zone_type);
2984 zonelist->_zonerefs[pos].zone = NULL;
2985 zonelist->_zonerefs[pos].zone_idx = 0;
2988 static int default_zonelist_order(void)
2991 unsigned long low_kmem_size,total_size;
2995 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2996 * If they are really small and used heavily, the system can fall
2997 * into OOM very easily.
2998 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3000 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3003 for_each_online_node(nid) {
3004 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3005 z = &NODE_DATA(nid)->node_zones[zone_type];
3006 if (populated_zone(z)) {
3007 if (zone_type < ZONE_NORMAL)
3008 low_kmem_size += z->present_pages;
3009 total_size += z->present_pages;
3010 } else if (zone_type == ZONE_NORMAL) {
3012 * If any node has only lowmem, then node order
3013 * is preferred to allow kernel allocations
3014 * locally; otherwise, they can easily infringe
3015 * on other nodes when there is an abundance of
3016 * lowmem available to allocate from.
3018 return ZONELIST_ORDER_NODE;
3022 if (!low_kmem_size || /* there are no DMA area. */
3023 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
3024 return ZONELIST_ORDER_NODE;
3026 * look into each node's config.
3027 * If there is a node whose DMA/DMA32 memory is very big area on
3028 * local memory, NODE_ORDER may be suitable.
3030 average_size = total_size /
3031 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
3032 for_each_online_node(nid) {
3035 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3036 z = &NODE_DATA(nid)->node_zones[zone_type];
3037 if (populated_zone(z)) {
3038 if (zone_type < ZONE_NORMAL)
3039 low_kmem_size += z->present_pages;
3040 total_size += z->present_pages;
3043 if (low_kmem_size &&
3044 total_size > average_size && /* ignore small node */
3045 low_kmem_size > total_size * 70/100)
3046 return ZONELIST_ORDER_NODE;
3048 return ZONELIST_ORDER_ZONE;
3051 static void set_zonelist_order(void)
3053 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3054 current_zonelist_order = default_zonelist_order();
3056 current_zonelist_order = user_zonelist_order;
3059 static void build_zonelists(pg_data_t *pgdat)
3063 nodemask_t used_mask;
3064 int local_node, prev_node;
3065 struct zonelist *zonelist;
3066 int order = current_zonelist_order;
3068 /* initialize zonelists */
3069 for (i = 0; i < MAX_ZONELISTS; i++) {
3070 zonelist = pgdat->node_zonelists + i;
3071 zonelist->_zonerefs[0].zone = NULL;
3072 zonelist->_zonerefs[0].zone_idx = 0;
3075 /* NUMA-aware ordering of nodes */
3076 local_node = pgdat->node_id;
3077 load = nr_online_nodes;
3078 prev_node = local_node;
3079 nodes_clear(used_mask);
3081 memset(node_order, 0, sizeof(node_order));
3084 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3085 int distance = node_distance(local_node, node);
3088 * If another node is sufficiently far away then it is better
3089 * to reclaim pages in a zone before going off node.
3091 if (distance > RECLAIM_DISTANCE)
3092 zone_reclaim_mode = 1;
3095 * We don't want to pressure a particular node.
3096 * So adding penalty to the first node in same
3097 * distance group to make it round-robin.
3099 if (distance != node_distance(local_node, prev_node))
3100 node_load[node] = load;
3104 if (order == ZONELIST_ORDER_NODE)
3105 build_zonelists_in_node_order(pgdat, node);
3107 node_order[j++] = node; /* remember order */
3110 if (order == ZONELIST_ORDER_ZONE) {
3111 /* calculate node order -- i.e., DMA last! */
3112 build_zonelists_in_zone_order(pgdat, j);
3115 build_thisnode_zonelists(pgdat);
3118 /* Construct the zonelist performance cache - see further mmzone.h */
3119 static void build_zonelist_cache(pg_data_t *pgdat)
3121 struct zonelist *zonelist;
3122 struct zonelist_cache *zlc;
3125 zonelist = &pgdat->node_zonelists[0];
3126 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3127 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3128 for (z = zonelist->_zonerefs; z->zone; z++)
3129 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3132 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3134 * Return node id of node used for "local" allocations.
3135 * I.e., first node id of first zone in arg node's generic zonelist.
3136 * Used for initializing percpu 'numa_mem', which is used primarily
3137 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3139 int local_memory_node(int node)
3143 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3144 gfp_zone(GFP_KERNEL),
3151 #else /* CONFIG_NUMA */
3153 static void set_zonelist_order(void)
3155 current_zonelist_order = ZONELIST_ORDER_ZONE;
3158 static void build_zonelists(pg_data_t *pgdat)
3160 int node, local_node;
3162 struct zonelist *zonelist;
3164 local_node = pgdat->node_id;
3166 zonelist = &pgdat->node_zonelists[0];
3167 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3170 * Now we build the zonelist so that it contains the zones
3171 * of all the other nodes.
3172 * We don't want to pressure a particular node, so when
3173 * building the zones for node N, we make sure that the
3174 * zones coming right after the local ones are those from
3175 * node N+1 (modulo N)
3177 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3178 if (!node_online(node))
3180 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3183 for (node = 0; node < local_node; node++) {
3184 if (!node_online(node))
3186 j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3190 zonelist->_zonerefs[j].zone = NULL;
3191 zonelist->_zonerefs[j].zone_idx = 0;
3194 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3195 static void build_zonelist_cache(pg_data_t *pgdat)
3197 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3200 #endif /* CONFIG_NUMA */
3203 * Boot pageset table. One per cpu which is going to be used for all
3204 * zones and all nodes. The parameters will be set in such a way
3205 * that an item put on a list will immediately be handed over to
3206 * the buddy list. This is safe since pageset manipulation is done
3207 * with interrupts disabled.
3209 * The boot_pagesets must be kept even after bootup is complete for
3210 * unused processors and/or zones. They do play a role for bootstrapping
3211 * hotplugged processors.
3213 * zoneinfo_show() and maybe other functions do
3214 * not check if the processor is online before following the pageset pointer.
3215 * Other parts of the kernel may not check if the zone is available.
3217 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3218 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3219 static void setup_zone_pageset(struct zone *zone);
3222 * Global mutex to protect against size modification of zonelists
3223 * as well as to serialize pageset setup for the new populated zone.
3225 DEFINE_MUTEX(zonelists_mutex);
3227 /* return values int ....just for stop_machine() */
3228 static __init_refok int __build_all_zonelists(void *data)
3234 memset(node_load, 0, sizeof(node_load));
3236 for_each_online_node(nid) {
3237 pg_data_t *pgdat = NODE_DATA(nid);
3239 build_zonelists(pgdat);
3240 build_zonelist_cache(pgdat);
3244 * Initialize the boot_pagesets that are going to be used
3245 * for bootstrapping processors. The real pagesets for
3246 * each zone will be allocated later when the per cpu
3247 * allocator is available.
3249 * boot_pagesets are used also for bootstrapping offline
3250 * cpus if the system is already booted because the pagesets
3251 * are needed to initialize allocators on a specific cpu too.
3252 * F.e. the percpu allocator needs the page allocator which
3253 * needs the percpu allocator in order to allocate its pagesets
3254 * (a chicken-egg dilemma).
3256 for_each_possible_cpu(cpu) {
3257 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3259 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3261 * We now know the "local memory node" for each node--
3262 * i.e., the node of the first zone in the generic zonelist.
3263 * Set up numa_mem percpu variable for on-line cpus. During
3264 * boot, only the boot cpu should be on-line; we'll init the
3265 * secondary cpus' numa_mem as they come on-line. During
3266 * node/memory hotplug, we'll fixup all on-line cpus.
3268 if (cpu_online(cpu))
3269 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3277 * Called with zonelists_mutex held always
3278 * unless system_state == SYSTEM_BOOTING.
3280 void __ref build_all_zonelists(void *data)
3282 set_zonelist_order();
3284 if (system_state == SYSTEM_BOOTING) {
3285 __build_all_zonelists(NULL);
3286 mminit_verify_zonelist();
3287 cpuset_init_current_mems_allowed();
3289 /* we have to stop all cpus to guarantee there is no user
3291 #ifdef CONFIG_MEMORY_HOTPLUG
3293 setup_zone_pageset((struct zone *)data);
3295 stop_machine(__build_all_zonelists, NULL, NULL);
3296 /* cpuset refresh routine should be here */
3298 vm_total_pages = nr_free_pagecache_pages();
3300 * Disable grouping by mobility if the number of pages in the
3301 * system is too low to allow the mechanism to work. It would be
3302 * more accurate, but expensive to check per-zone. This check is
3303 * made on memory-hotadd so a system can start with mobility
3304 * disabled and enable it later
3306 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3307 page_group_by_mobility_disabled = 1;
3309 page_group_by_mobility_disabled = 0;
3311 printk("Built %i zonelists in %s order, mobility grouping %s. "
3312 "Total pages: %ld\n",
3314 zonelist_order_name[current_zonelist_order],
3315 page_group_by_mobility_disabled ? "off" : "on",
3318 printk("Policy zone: %s\n", zone_names[policy_zone]);
3323 * Helper functions to size the waitqueue hash table.
3324 * Essentially these want to choose hash table sizes sufficiently
3325 * large so that collisions trying to wait on pages are rare.
3326 * But in fact, the number of active page waitqueues on typical
3327 * systems is ridiculously low, less than 200. So this is even
3328 * conservative, even though it seems large.
3330 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3331 * waitqueues, i.e. the size of the waitq table given the number of pages.
3333 #define PAGES_PER_WAITQUEUE 256
3335 #ifndef CONFIG_MEMORY_HOTPLUG
3336 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3338 unsigned long size = 1;
3340 pages /= PAGES_PER_WAITQUEUE;
3342 while (size < pages)
3346 * Once we have dozens or even hundreds of threads sleeping
3347 * on IO we've got bigger problems than wait queue collision.
3348 * Limit the size of the wait table to a reasonable size.
3350 size = min(size, 4096UL);
3352 return max(size, 4UL);
3356 * A zone's size might be changed by hot-add, so it is not possible to determine
3357 * a suitable size for its wait_table. So we use the maximum size now.
3359 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3361 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3362 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3363 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3365 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3366 * or more by the traditional way. (See above). It equals:
3368 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3369 * ia64(16K page size) : = ( 8G + 4M)byte.
3370 * powerpc (64K page size) : = (32G +16M)byte.
3372 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3379 * This is an integer logarithm so that shifts can be used later
3380 * to extract the more random high bits from the multiplicative
3381 * hash function before the remainder is taken.
3383 static inline unsigned long wait_table_bits(unsigned long size)
3388 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3391 * Check if a pageblock contains reserved pages
3393 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3397 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3398 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3405 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3406 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3407 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3408 * higher will lead to a bigger reserve which will get freed as contiguous
3409 * blocks as reclaim kicks in
3411 static void setup_zone_migrate_reserve(struct zone *zone)
3413 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3415 unsigned long block_migratetype;
3419 * Get the start pfn, end pfn and the number of blocks to reserve
3420 * We have to be careful to be aligned to pageblock_nr_pages to
3421 * make sure that we always check pfn_valid for the first page in
3424 start_pfn = zone->zone_start_pfn;
3425 end_pfn = start_pfn + zone->spanned_pages;
3426 start_pfn = roundup(start_pfn, pageblock_nr_pages);
3427 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3431 * Reserve blocks are generally in place to help high-order atomic
3432 * allocations that are short-lived. A min_free_kbytes value that
3433 * would result in more than 2 reserve blocks for atomic allocations
3434 * is assumed to be in place to help anti-fragmentation for the
3435 * future allocation of hugepages at runtime.
3437 reserve = min(2, reserve);
3439 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3440 if (!pfn_valid(pfn))
3442 page = pfn_to_page(pfn);
3444 /* Watch out for overlapping nodes */
3445 if (page_to_nid(page) != zone_to_nid(zone))
3448 block_migratetype = get_pageblock_migratetype(page);
3450 /* Only test what is necessary when the reserves are not met */
3453 * Blocks with reserved pages will never free, skip
3456 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
3457 if (pageblock_is_reserved(pfn, block_end_pfn))
3460 /* If this block is reserved, account for it */
3461 if (block_migratetype == MIGRATE_RESERVE) {
3466 /* Suitable for reserving if this block is movable */
3467 if (block_migratetype == MIGRATE_MOVABLE) {
3468 set_pageblock_migratetype(page,
3470 move_freepages_block(zone, page,
3478 * If the reserve is met and this is a previous reserved block,
3481 if (block_migratetype == MIGRATE_RESERVE) {
3482 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3483 move_freepages_block(zone, page, MIGRATE_MOVABLE);
3489 * Initially all pages are reserved - free ones are freed
3490 * up by free_all_bootmem() once the early boot process is
3491 * done. Non-atomic initialization, single-pass.
3493 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
3494 unsigned long start_pfn, enum memmap_context context)
3497 unsigned long end_pfn = start_pfn + size;
3501 if (highest_memmap_pfn < end_pfn - 1)
3502 highest_memmap_pfn = end_pfn - 1;
3504 z = &NODE_DATA(nid)->node_zones[zone];
3505 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3507 * There can be holes in boot-time mem_map[]s
3508 * handed to this function. They do not
3509 * exist on hotplugged memory.
3511 if (context == MEMMAP_EARLY) {
3512 if (!early_pfn_valid(pfn))
3514 if (!early_pfn_in_nid(pfn, nid))
3517 page = pfn_to_page(pfn);
3518 set_page_links(page, zone, nid, pfn);
3519 mminit_verify_page_links(page, zone, nid, pfn);
3520 init_page_count(page);
3521 reset_page_mapcount(page);
3522 SetPageReserved(page);
3524 * Mark the block movable so that blocks are reserved for
3525 * movable at startup. This will force kernel allocations
3526 * to reserve their blocks rather than leaking throughout
3527 * the address space during boot when many long-lived
3528 * kernel allocations are made. Later some blocks near
3529 * the start are marked MIGRATE_RESERVE by
3530 * setup_zone_migrate_reserve()
3532 * bitmap is created for zone's valid pfn range. but memmap
3533 * can be created for invalid pages (for alignment)
3534 * check here not to call set_pageblock_migratetype() against
3537 if ((z->zone_start_pfn <= pfn)
3538 && (pfn < z->zone_start_pfn + z->spanned_pages)
3539 && !(pfn & (pageblock_nr_pages - 1)))
3540 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3542 INIT_LIST_HEAD(&page->lru);
3543 #ifdef WANT_PAGE_VIRTUAL
3544 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3545 if (!is_highmem_idx(zone))
3546 set_page_address(page, __va(pfn << PAGE_SHIFT));
3551 static void __meminit zone_init_free_lists(struct zone *zone)
3554 for_each_migratetype_order(order, t) {
3555 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
3556 zone->free_area[order].nr_free = 0;
3560 #ifndef __HAVE_ARCH_MEMMAP_INIT
3561 #define memmap_init(size, nid, zone, start_pfn) \
3562 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3565 static int zone_batchsize(struct zone *zone)
3571 * The per-cpu-pages pools are set to around 1000th of the
3572 * size of the zone. But no more than 1/2 of a meg.
3574 * OK, so we don't know how big the cache is. So guess.
3576 batch = zone->present_pages / 1024;
3577 if (batch * PAGE_SIZE > 512 * 1024)
3578 batch = (512 * 1024) / PAGE_SIZE;
3579 batch /= 4; /* We effectively *= 4 below */
3584 * Clamp the batch to a 2^n - 1 value. Having a power
3585 * of 2 value was found to be more likely to have
3586 * suboptimal cache aliasing properties in some cases.
3588 * For example if 2 tasks are alternately allocating
3589 * batches of pages, one task can end up with a lot
3590 * of pages of one half of the possible page colors
3591 * and the other with pages of the other colors.
3593 batch = rounddown_pow_of_two(batch + batch/2) - 1;
3598 /* The deferral and batching of frees should be suppressed under NOMMU
3601 * The problem is that NOMMU needs to be able to allocate large chunks
3602 * of contiguous memory as there's no hardware page translation to
3603 * assemble apparent contiguous memory from discontiguous pages.
3605 * Queueing large contiguous runs of pages for batching, however,
3606 * causes the pages to actually be freed in smaller chunks. As there
3607 * can be a significant delay between the individual batches being
3608 * recycled, this leads to the once large chunks of space being
3609 * fragmented and becoming unavailable for high-order allocations.
3615 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3617 struct per_cpu_pages *pcp;
3620 memset(p, 0, sizeof(*p));
3624 pcp->high = 6 * batch;
3625 pcp->batch = max(1UL, 1 * batch);
3626 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
3627 INIT_LIST_HEAD(&pcp->lists[migratetype]);
3631 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3632 * to the value high for the pageset p.
3635 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
3638 struct per_cpu_pages *pcp;
3642 pcp->batch = max(1UL, high/4);
3643 if ((high/4) > (PAGE_SHIFT * 8))
3644 pcp->batch = PAGE_SHIFT * 8;
3647 static void setup_zone_pageset(struct zone *zone)
3651 zone->pageset = alloc_percpu(struct per_cpu_pageset);
3653 for_each_possible_cpu(cpu) {
3654 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
3656 setup_pageset(pcp, zone_batchsize(zone));
3658 if (percpu_pagelist_fraction)
3659 setup_pagelist_highmark(pcp,
3660 (zone->present_pages /
3661 percpu_pagelist_fraction));
3666 * Allocate per cpu pagesets and initialize them.
3667 * Before this call only boot pagesets were available.
3669 void __init setup_per_cpu_pageset(void)
3673 for_each_populated_zone(zone)
3674 setup_zone_pageset(zone);
3677 static noinline __init_refok
3678 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3681 struct pglist_data *pgdat = zone->zone_pgdat;
3685 * The per-page waitqueue mechanism uses hashed waitqueues
3688 zone->wait_table_hash_nr_entries =
3689 wait_table_hash_nr_entries(zone_size_pages);
3690 zone->wait_table_bits =
3691 wait_table_bits(zone->wait_table_hash_nr_entries);
3692 alloc_size = zone->wait_table_hash_nr_entries
3693 * sizeof(wait_queue_head_t);
3695 if (!slab_is_available()) {
3696 zone->wait_table = (wait_queue_head_t *)
3697 alloc_bootmem_node_nopanic(pgdat, alloc_size);
3700 * This case means that a zone whose size was 0 gets new memory
3701 * via memory hot-add.
3702 * But it may be the case that a new node was hot-added. In
3703 * this case vmalloc() will not be able to use this new node's
3704 * memory - this wait_table must be initialized to use this new
3705 * node itself as well.
3706 * To use this new node's memory, further consideration will be
3709 zone->wait_table = vmalloc(alloc_size);
3711 if (!zone->wait_table)
3714 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3715 init_waitqueue_head(zone->wait_table + i);
3720 static int __zone_pcp_update(void *data)
3722 struct zone *zone = data;
3724 unsigned long batch = zone_batchsize(zone), flags;
3726 for_each_possible_cpu(cpu) {
3727 struct per_cpu_pageset *pset;
3728 struct per_cpu_pages *pcp;
3730 pset = per_cpu_ptr(zone->pageset, cpu);
3733 local_irq_save(flags);
3734 free_pcppages_bulk(zone, pcp->count, pcp);
3735 setup_pageset(pset, batch);
3736 local_irq_restore(flags);
3741 void zone_pcp_update(struct zone *zone)
3743 stop_machine(__zone_pcp_update, zone, NULL);
3746 static __meminit void zone_pcp_init(struct zone *zone)
3749 * per cpu subsystem is not up at this point. The following code
3750 * relies on the ability of the linker to provide the
3751 * offset of a (static) per cpu variable into the per cpu area.
3753 zone->pageset = &boot_pageset;
3755 if (zone->present_pages)
3756 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
3757 zone->name, zone->present_pages,
3758 zone_batchsize(zone));
3761 __meminit int init_currently_empty_zone(struct zone *zone,
3762 unsigned long zone_start_pfn,
3764 enum memmap_context context)
3766 struct pglist_data *pgdat = zone->zone_pgdat;
3768 ret = zone_wait_table_init(zone, size);
3771 pgdat->nr_zones = zone_idx(zone) + 1;
3773 zone->zone_start_pfn = zone_start_pfn;
3775 mminit_dprintk(MMINIT_TRACE, "memmap_init",
3776 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3778 (unsigned long)zone_idx(zone),
3779 zone_start_pfn, (zone_start_pfn + size));
3781 zone_init_free_lists(zone);
3786 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3788 * Basic iterator support. Return the first range of PFNs for a node
3789 * Note: nid == MAX_NUMNODES returns first region regardless of node
3791 static int __meminit first_active_region_index_in_nid(int nid)
3795 for (i = 0; i < nr_nodemap_entries; i++)
3796 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3803 * Basic iterator support. Return the next active range of PFNs for a node
3804 * Note: nid == MAX_NUMNODES returns next region regardless of node
3806 static int __meminit next_active_region_index_in_nid(int index, int nid)
3808 for (index = index + 1; index < nr_nodemap_entries; index++)
3809 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3815 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3817 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3818 * Architectures may implement their own version but if add_active_range()
3819 * was used and there are no special requirements, this is a convenient
3822 int __meminit __early_pfn_to_nid(unsigned long pfn)
3826 for (i = 0; i < nr_nodemap_entries; i++) {
3827 unsigned long start_pfn = early_node_map[i].start_pfn;
3828 unsigned long end_pfn = early_node_map[i].end_pfn;
3830 if (start_pfn <= pfn && pfn < end_pfn)
3831 return early_node_map[i].nid;
3833 /* This is a memory hole */
3836 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3838 int __meminit early_pfn_to_nid(unsigned long pfn)
3842 nid = __early_pfn_to_nid(pfn);
3845 /* just returns 0 */
3849 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3850 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
3854 nid = __early_pfn_to_nid(pfn);
3855 if (nid >= 0 && nid != node)
3861 /* Basic iterator support to walk early_node_map[] */
3862 #define for_each_active_range_index_in_nid(i, nid) \
3863 for (i = first_active_region_index_in_nid(nid); i != -1; \
3864 i = next_active_region_index_in_nid(i, nid))
3867 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3868 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3869 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3871 * If an architecture guarantees that all ranges registered with
3872 * add_active_ranges() contain no holes and may be freed, this
3873 * this function may be used instead of calling free_bootmem() manually.
3875 void __init free_bootmem_with_active_regions(int nid,
3876 unsigned long max_low_pfn)
3880 for_each_active_range_index_in_nid(i, nid) {
3881 unsigned long size_pages = 0;
3882 unsigned long end_pfn = early_node_map[i].end_pfn;
3884 if (early_node_map[i].start_pfn >= max_low_pfn)
3887 if (end_pfn > max_low_pfn)
3888 end_pfn = max_low_pfn;
3890 size_pages = end_pfn - early_node_map[i].start_pfn;
3891 free_bootmem_node(NODE_DATA(early_node_map[i].nid),
3892 PFN_PHYS(early_node_map[i].start_pfn),
3893 size_pages << PAGE_SHIFT);
3897 #ifdef CONFIG_HAVE_MEMBLOCK
3899 * Basic iterator support. Return the last range of PFNs for a node
3900 * Note: nid == MAX_NUMNODES returns last region regardless of node
3902 static int __meminit last_active_region_index_in_nid(int nid)
3906 for (i = nr_nodemap_entries - 1; i >= 0; i--)
3907 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
3914 * Basic iterator support. Return the previous active range of PFNs for a node
3915 * Note: nid == MAX_NUMNODES returns next region regardless of node
3917 static int __meminit previous_active_region_index_in_nid(int index, int nid)
3919 for (index = index - 1; index >= 0; index--)
3920 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
3926 #define for_each_active_range_index_in_nid_reverse(i, nid) \
3927 for (i = last_active_region_index_in_nid(nid); i != -1; \
3928 i = previous_active_region_index_in_nid(i, nid))
3930 u64 __init find_memory_core_early(int nid, u64 size, u64 align,
3931 u64 goal, u64 limit)
3935 /* Need to go over early_node_map to find out good range for node */
3936 for_each_active_range_index_in_nid_reverse(i, nid) {
3938 u64 ei_start, ei_last;
3939 u64 final_start, final_end;
3941 ei_last = early_node_map[i].end_pfn;
3942 ei_last <<= PAGE_SHIFT;
3943 ei_start = early_node_map[i].start_pfn;
3944 ei_start <<= PAGE_SHIFT;
3946 final_start = max(ei_start, goal);
3947 final_end = min(ei_last, limit);
3949 if (final_start >= final_end)
3952 addr = memblock_find_in_range(final_start, final_end, size, align);
3954 if (addr == MEMBLOCK_ERROR)
3960 return MEMBLOCK_ERROR;
3964 int __init add_from_early_node_map(struct range *range, int az,
3965 int nr_range, int nid)
3970 /* need to go over early_node_map to find out good range for node */
3971 for_each_active_range_index_in_nid(i, nid) {
3972 start = early_node_map[i].start_pfn;
3973 end = early_node_map[i].end_pfn;
3974 nr_range = add_range(range, az, nr_range, start, end);
3979 void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
3984 for_each_active_range_index_in_nid(i, nid) {
3985 ret = work_fn(early_node_map[i].start_pfn,
3986 early_node_map[i].end_pfn, data);
3992 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3993 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3995 * If an architecture guarantees that all ranges registered with
3996 * add_active_ranges() contain no holes and may be freed, this
3997 * function may be used instead of calling memory_present() manually.
3999 void __init sparse_memory_present_with_active_regions(int nid)
4003 for_each_active_range_index_in_nid(i, nid)
4004 memory_present(early_node_map[i].nid,
4005 early_node_map[i].start_pfn,
4006 early_node_map[i].end_pfn);
4010 * get_pfn_range_for_nid - Return the start and end page frames for a node
4011 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4012 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4013 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4015 * It returns the start and end page frame of a node based on information
4016 * provided by an arch calling add_active_range(). If called for a node
4017 * with no available memory, a warning is printed and the start and end
4020 void __meminit get_pfn_range_for_nid(unsigned int nid,
4021 unsigned long *start_pfn, unsigned long *end_pfn)
4027 for_each_active_range_index_in_nid(i, nid) {
4028 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
4029 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
4032 if (*start_pfn == -1UL)
4037 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4038 * assumption is made that zones within a node are ordered in monotonic
4039 * increasing memory addresses so that the "highest" populated zone is used
4041 static void __init find_usable_zone_for_movable(void)
4044 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4045 if (zone_index == ZONE_MOVABLE)
4048 if (arch_zone_highest_possible_pfn[zone_index] >
4049 arch_zone_lowest_possible_pfn[zone_index])
4053 VM_BUG_ON(zone_index == -1);
4054 movable_zone = zone_index;
4058 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4059 * because it is sized independent of architecture. Unlike the other zones,
4060 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4061 * in each node depending on the size of each node and how evenly kernelcore
4062 * is distributed. This helper function adjusts the zone ranges
4063 * provided by the architecture for a given node by using the end of the
4064 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4065 * zones within a node are in order of monotonic increases memory addresses
4067 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4068 unsigned long zone_type,
4069 unsigned long node_start_pfn,
4070 unsigned long node_end_pfn,
4071 unsigned long *zone_start_pfn,
4072 unsigned long *zone_end_pfn)
4074 /* Only adjust if ZONE_MOVABLE is on this node */
4075 if (zone_movable_pfn[nid]) {
4076 /* Size ZONE_MOVABLE */
4077 if (zone_type == ZONE_MOVABLE) {
4078 *zone_start_pfn = zone_movable_pfn[nid];
4079 *zone_end_pfn = min(node_end_pfn,
4080 arch_zone_highest_possible_pfn[movable_zone]);
4082 /* Adjust for ZONE_MOVABLE starting within this range */
4083 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4084 *zone_end_pfn > zone_movable_pfn[nid]) {
4085 *zone_end_pfn = zone_movable_pfn[nid];
4087 /* Check if this whole range is within ZONE_MOVABLE */
4088 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4089 *zone_start_pfn = *zone_end_pfn;
4094 * Return the number of pages a zone spans in a node, including holes
4095 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4097 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4098 unsigned long zone_type,
4099 unsigned long *ignored)
4101 unsigned long node_start_pfn, node_end_pfn;
4102 unsigned long zone_start_pfn, zone_end_pfn;
4104 /* Get the start and end of the node and zone */
4105 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4106 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4107 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4108 adjust_zone_range_for_zone_movable(nid, zone_type,
4109 node_start_pfn, node_end_pfn,
4110 &zone_start_pfn, &zone_end_pfn);
4112 /* Check that this node has pages within the zone's required range */
4113 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4116 /* Move the zone boundaries inside the node if necessary */
4117 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4118 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4120 /* Return the spanned pages */
4121 return zone_end_pfn - zone_start_pfn;
4125 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4126 * then all holes in the requested range will be accounted for.
4128 unsigned long __meminit __absent_pages_in_range(int nid,
4129 unsigned long range_start_pfn,
4130 unsigned long range_end_pfn)
4133 unsigned long prev_end_pfn = 0, hole_pages = 0;
4134 unsigned long start_pfn;
4136 /* Find the end_pfn of the first active range of pfns in the node */
4137 i = first_active_region_index_in_nid(nid);
4141 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
4143 /* Account for ranges before physical memory on this node */
4144 if (early_node_map[i].start_pfn > range_start_pfn)
4145 hole_pages = prev_end_pfn - range_start_pfn;
4147 /* Find all holes for the zone within the node */
4148 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
4150 /* No need to continue if prev_end_pfn is outside the zone */
4151 if (prev_end_pfn >= range_end_pfn)
4154 /* Make sure the end of the zone is not within the hole */
4155 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
4156 prev_end_pfn = max(prev_end_pfn, range_start_pfn);
4158 /* Update the hole size cound and move on */
4159 if (start_pfn > range_start_pfn) {
4160 BUG_ON(prev_end_pfn > start_pfn);
4161 hole_pages += start_pfn - prev_end_pfn;
4163 prev_end_pfn = early_node_map[i].end_pfn;
4166 /* Account for ranges past physical memory on this node */
4167 if (range_end_pfn > prev_end_pfn)
4168 hole_pages += range_end_pfn -
4169 max(range_start_pfn, prev_end_pfn);
4175 * absent_pages_in_range - Return number of page frames in holes within a range
4176 * @start_pfn: The start PFN to start searching for holes
4177 * @end_pfn: The end PFN to stop searching for holes
4179 * It returns the number of pages frames in memory holes within a range.
4181 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4182 unsigned long end_pfn)
4184 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4187 /* Return the number of page frames in holes in a zone on a node */
4188 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4189 unsigned long zone_type,
4190 unsigned long *ignored)
4192 unsigned long node_start_pfn, node_end_pfn;
4193 unsigned long zone_start_pfn, zone_end_pfn;
4195 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4196 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
4198 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
4201 adjust_zone_range_for_zone_movable(nid, zone_type,
4202 node_start_pfn, node_end_pfn,
4203 &zone_start_pfn, &zone_end_pfn);
4204 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4208 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4209 unsigned long zone_type,
4210 unsigned long *zones_size)
4212 return zones_size[zone_type];
4215 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4216 unsigned long zone_type,
4217 unsigned long *zholes_size)
4222 return zholes_size[zone_type];
4227 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4228 unsigned long *zones_size, unsigned long *zholes_size)
4230 unsigned long realtotalpages, totalpages = 0;
4233 for (i = 0; i < MAX_NR_ZONES; i++)
4234 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4236 pgdat->node_spanned_pages = totalpages;
4238 realtotalpages = totalpages;
4239 for (i = 0; i < MAX_NR_ZONES; i++)
4241 zone_absent_pages_in_node(pgdat->node_id, i,
4243 pgdat->node_present_pages = realtotalpages;
4244 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4248 #ifndef CONFIG_SPARSEMEM
4250 * Calculate the size of the zone->blockflags rounded to an unsigned long
4251 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4252 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4253 * round what is now in bits to nearest long in bits, then return it in
4256 static unsigned long __init usemap_size(unsigned long zonesize)
4258 unsigned long usemapsize;
4260 usemapsize = roundup(zonesize, pageblock_nr_pages);
4261 usemapsize = usemapsize >> pageblock_order;
4262 usemapsize *= NR_PAGEBLOCK_BITS;
4263 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4265 return usemapsize / 8;
4268 static void __init setup_usemap(struct pglist_data *pgdat,
4269 struct zone *zone, unsigned long zonesize)
4271 unsigned long usemapsize = usemap_size(zonesize);
4272 zone->pageblock_flags = NULL;
4274 zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
4278 static inline void setup_usemap(struct pglist_data *pgdat,
4279 struct zone *zone, unsigned long zonesize) {}
4280 #endif /* CONFIG_SPARSEMEM */
4282 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4284 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4285 void __init set_pageblock_order(void)
4289 /* Check that pageblock_nr_pages has not already been setup */
4290 if (pageblock_order)
4293 if (HPAGE_SHIFT > PAGE_SHIFT)
4294 order = HUGETLB_PAGE_ORDER;
4296 order = MAX_ORDER - 1;
4299 * Assume the largest contiguous order of interest is a huge page.
4300 * This value may be variable depending on boot parameters on IA64 and
4303 pageblock_order = order;
4305 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4308 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4309 * is unused as pageblock_order is set at compile-time. See
4310 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4313 void __init set_pageblock_order(void)
4317 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4320 * Set up the zone data structures:
4321 * - mark all pages reserved
4322 * - mark all memory queues empty
4323 * - clear the memory bitmaps
4325 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4326 unsigned long *zones_size, unsigned long *zholes_size)
4329 int nid = pgdat->node_id;
4330 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4333 pgdat_resize_init(pgdat);
4334 pgdat->nr_zones = 0;
4335 init_waitqueue_head(&pgdat->kswapd_wait);
4336 pgdat->kswapd_max_order = 0;
4337 pgdat_page_cgroup_init(pgdat);
4339 for (j = 0; j < MAX_NR_ZONES; j++) {
4340 struct zone *zone = pgdat->node_zones + j;
4341 unsigned long size, realsize, memmap_pages;
4344 size = zone_spanned_pages_in_node(nid, j, zones_size);
4345 realsize = size - zone_absent_pages_in_node(nid, j,
4349 * Adjust realsize so that it accounts for how much memory
4350 * is used by this zone for memmap. This affects the watermark
4351 * and per-cpu initialisations
4354 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4355 if (realsize >= memmap_pages) {
4356 realsize -= memmap_pages;
4359 " %s zone: %lu pages used for memmap\n",
4360 zone_names[j], memmap_pages);
4363 " %s zone: %lu pages exceeds realsize %lu\n",
4364 zone_names[j], memmap_pages, realsize);
4366 /* Account for reserved pages */
4367 if (j == 0 && realsize > dma_reserve) {
4368 realsize -= dma_reserve;
4369 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4370 zone_names[0], dma_reserve);
4373 if (!is_highmem_idx(j))
4374 nr_kernel_pages += realsize;
4375 nr_all_pages += realsize;
4377 zone->spanned_pages = size;
4378 zone->present_pages = realsize;
4381 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4383 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4385 zone->name = zone_names[j];
4386 spin_lock_init(&zone->lock);
4387 spin_lock_init(&zone->lru_lock);
4388 zone_seqlock_init(zone);
4389 zone->zone_pgdat = pgdat;
4391 zone_pcp_init(zone);
4393 INIT_LIST_HEAD(&zone->lru[l].list);
4394 zone->reclaim_stat.recent_rotated[0] = 0;
4395 zone->reclaim_stat.recent_rotated[1] = 0;
4396 zone->reclaim_stat.recent_scanned[0] = 0;
4397 zone->reclaim_stat.recent_scanned[1] = 0;
4398 zap_zone_vm_stats(zone);
4403 set_pageblock_order();
4404 setup_usemap(pgdat, zone, size);
4405 ret = init_currently_empty_zone(zone, zone_start_pfn,
4406 size, MEMMAP_EARLY);
4408 memmap_init(size, nid, j, zone_start_pfn);
4409 zone_start_pfn += size;
4413 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4415 /* Skip empty nodes */
4416 if (!pgdat->node_spanned_pages)
4419 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4420 /* ia64 gets its own node_mem_map, before this, without bootmem */
4421 if (!pgdat->node_mem_map) {
4422 unsigned long size, start, end;
4426 * The zone's endpoints aren't required to be MAX_ORDER
4427 * aligned but the node_mem_map endpoints must be in order
4428 * for the buddy allocator to function correctly.
4430 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4431 end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
4432 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4433 size = (end - start) * sizeof(struct page);
4434 map = alloc_remap(pgdat->node_id, size);
4436 map = alloc_bootmem_node_nopanic(pgdat, size);
4437 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4439 #ifndef CONFIG_NEED_MULTIPLE_NODES
4441 * With no DISCONTIG, the global mem_map is just set as node 0's
4443 if (pgdat == NODE_DATA(0)) {
4444 mem_map = NODE_DATA(0)->node_mem_map;
4445 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4446 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4447 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4448 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4451 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4454 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4455 unsigned long node_start_pfn, unsigned long *zholes_size)
4457 pg_data_t *pgdat = NODE_DATA(nid);
4459 pgdat->node_id = nid;
4460 pgdat->node_start_pfn = node_start_pfn;
4461 calculate_node_totalpages(pgdat, zones_size, zholes_size);
4463 alloc_node_mem_map(pgdat);
4464 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4465 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4466 nid, (unsigned long)pgdat,
4467 (unsigned long)pgdat->node_mem_map);
4470 free_area_init_core(pgdat, zones_size, zholes_size);
4473 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4475 #if MAX_NUMNODES > 1
4477 * Figure out the number of possible node ids.
4479 static void __init setup_nr_node_ids(void)
4482 unsigned int highest = 0;
4484 for_each_node_mask(node, node_possible_map)
4486 nr_node_ids = highest + 1;
4489 static inline void setup_nr_node_ids(void)
4495 * add_active_range - Register a range of PFNs backed by physical memory
4496 * @nid: The node ID the range resides on
4497 * @start_pfn: The start PFN of the available physical memory
4498 * @end_pfn: The end PFN of the available physical memory
4500 * These ranges are stored in an early_node_map[] and later used by
4501 * free_area_init_nodes() to calculate zone sizes and holes. If the
4502 * range spans a memory hole, it is up to the architecture to ensure
4503 * the memory is not freed by the bootmem allocator. If possible
4504 * the range being registered will be merged with existing ranges.
4506 void __init add_active_range(unsigned int nid, unsigned long start_pfn,
4507 unsigned long end_pfn)
4511 mminit_dprintk(MMINIT_TRACE, "memory_register",
4512 "Entering add_active_range(%d, %#lx, %#lx) "
4513 "%d entries of %d used\n",
4514 nid, start_pfn, end_pfn,
4515 nr_nodemap_entries, MAX_ACTIVE_REGIONS);
4517 mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
4519 /* Merge with existing active regions if possible */
4520 for (i = 0; i < nr_nodemap_entries; i++) {
4521 if (early_node_map[i].nid != nid)
4524 /* Skip if an existing region covers this new one */
4525 if (start_pfn >= early_node_map[i].start_pfn &&
4526 end_pfn <= early_node_map[i].end_pfn)
4529 /* Merge forward if suitable */
4530 if (start_pfn <= early_node_map[i].end_pfn &&
4531 end_pfn > early_node_map[i].end_pfn) {
4532 early_node_map[i].end_pfn = end_pfn;
4536 /* Merge backward if suitable */
4537 if (start_pfn < early_node_map[i].start_pfn &&
4538 end_pfn >= early_node_map[i].start_pfn) {
4539 early_node_map[i].start_pfn = start_pfn;
4544 /* Check that early_node_map is large enough */
4545 if (i >= MAX_ACTIVE_REGIONS) {
4546 printk(KERN_CRIT "More than %d memory regions, truncating\n",
4547 MAX_ACTIVE_REGIONS);
4551 early_node_map[i].nid = nid;
4552 early_node_map[i].start_pfn = start_pfn;
4553 early_node_map[i].end_pfn = end_pfn;
4554 nr_nodemap_entries = i + 1;
4558 * remove_active_range - Shrink an existing registered range of PFNs
4559 * @nid: The node id the range is on that should be shrunk
4560 * @start_pfn: The new PFN of the range
4561 * @end_pfn: The new PFN of the range
4563 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4564 * The map is kept near the end physical page range that has already been
4565 * registered. This function allows an arch to shrink an existing registered
4568 void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
4569 unsigned long end_pfn)
4574 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
4575 nid, start_pfn, end_pfn);
4577 /* Find the old active region end and shrink */
4578 for_each_active_range_index_in_nid(i, nid) {
4579 if (early_node_map[i].start_pfn >= start_pfn &&
4580 early_node_map[i].end_pfn <= end_pfn) {
4582 early_node_map[i].start_pfn = 0;
4583 early_node_map[i].end_pfn = 0;
4587 if (early_node_map[i].start_pfn < start_pfn &&
4588 early_node_map[i].end_pfn > start_pfn) {
4589 unsigned long temp_end_pfn = early_node_map[i].end_pfn;
4590 early_node_map[i].end_pfn = start_pfn;
4591 if (temp_end_pfn > end_pfn)
4592 add_active_range(nid, end_pfn, temp_end_pfn);
4595 if (early_node_map[i].start_pfn >= start_pfn &&
4596 early_node_map[i].end_pfn > end_pfn &&
4597 early_node_map[i].start_pfn < end_pfn) {
4598 early_node_map[i].start_pfn = end_pfn;
4606 /* remove the blank ones */
4607 for (i = nr_nodemap_entries - 1; i > 0; i--) {
4608 if (early_node_map[i].nid != nid)
4610 if (early_node_map[i].end_pfn)
4612 /* we found it, get rid of it */
4613 for (j = i; j < nr_nodemap_entries - 1; j++)
4614 memcpy(&early_node_map[j], &early_node_map[j+1],
4615 sizeof(early_node_map[j]));
4616 j = nr_nodemap_entries - 1;
4617 memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
4618 nr_nodemap_entries--;
4623 * remove_all_active_ranges - Remove all currently registered regions
4625 * During discovery, it may be found that a table like SRAT is invalid
4626 * and an alternative discovery method must be used. This function removes
4627 * all currently registered regions.
4629 void __init remove_all_active_ranges(void)
4631 memset(early_node_map, 0, sizeof(early_node_map));
4632 nr_nodemap_entries = 0;
4635 /* Compare two active node_active_regions */
4636 static int __init cmp_node_active_region(const void *a, const void *b)
4638 struct node_active_region *arange = (struct node_active_region *)a;
4639 struct node_active_region *brange = (struct node_active_region *)b;
4641 /* Done this way to avoid overflows */
4642 if (arange->start_pfn > brange->start_pfn)
4644 if (arange->start_pfn < brange->start_pfn)
4650 /* sort the node_map by start_pfn */
4651 void __init sort_node_map(void)
4653 sort(early_node_map, (size_t)nr_nodemap_entries,
4654 sizeof(struct node_active_region),
4655 cmp_node_active_region, NULL);
4659 * node_map_pfn_alignment - determine the maximum internode alignment
4661 * This function should be called after node map is populated and sorted.
4662 * It calculates the maximum power of two alignment which can distinguish
4665 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4666 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4667 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4668 * shifted, 1GiB is enough and this function will indicate so.
4670 * This is used to test whether pfn -> nid mapping of the chosen memory
4671 * model has fine enough granularity to avoid incorrect mapping for the
4672 * populated node map.
4674 * Returns the determined alignment in pfn's. 0 if there is no alignment
4675 * requirement (single node).
4677 unsigned long __init node_map_pfn_alignment(void)
4679 unsigned long accl_mask = 0, last_end = 0;
4683 for_each_active_range_index_in_nid(i, MAX_NUMNODES) {
4684 int nid = early_node_map[i].nid;
4685 unsigned long start = early_node_map[i].start_pfn;
4686 unsigned long end = early_node_map[i].end_pfn;
4689 if (!start || last_nid < 0 || last_nid == nid) {
4696 * Start with a mask granular enough to pin-point to the
4697 * start pfn and tick off bits one-by-one until it becomes
4698 * too coarse to separate the current node from the last.
4700 mask = ~((1 << __ffs(start)) - 1);
4701 while (mask && last_end <= (start & (mask << 1)))
4704 /* accumulate all internode masks */
4708 /* convert mask to number of pages */
4709 return ~accl_mask + 1;
4712 /* Find the lowest pfn for a node */
4713 static unsigned long __init find_min_pfn_for_node(int nid)
4716 unsigned long min_pfn = ULONG_MAX;
4718 /* Assuming a sorted map, the first range found has the starting pfn */
4719 for_each_active_range_index_in_nid(i, nid)
4720 min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4722 if (min_pfn == ULONG_MAX) {
4724 "Could not find start_pfn for node %d\n", nid);
4732 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4734 * It returns the minimum PFN based on information provided via
4735 * add_active_range().
4737 unsigned long __init find_min_pfn_with_active_regions(void)
4739 return find_min_pfn_for_node(MAX_NUMNODES);
4743 * early_calculate_totalpages()
4744 * Sum pages in active regions for movable zone.
4745 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4747 static unsigned long __init early_calculate_totalpages(void)
4750 unsigned long totalpages = 0;
4752 for (i = 0; i < nr_nodemap_entries; i++) {
4753 unsigned long pages = early_node_map[i].end_pfn -
4754 early_node_map[i].start_pfn;
4755 totalpages += pages;
4757 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
4763 * Find the PFN the Movable zone begins in each node. Kernel memory
4764 * is spread evenly between nodes as long as the nodes have enough
4765 * memory. When they don't, some nodes will have more kernelcore than
4768 static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
4771 unsigned long usable_startpfn;
4772 unsigned long kernelcore_node, kernelcore_remaining;
4773 /* save the state before borrow the nodemask */
4774 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4775 unsigned long totalpages = early_calculate_totalpages();
4776 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
4779 * If movablecore was specified, calculate what size of
4780 * kernelcore that corresponds so that memory usable for
4781 * any allocation type is evenly spread. If both kernelcore
4782 * and movablecore are specified, then the value of kernelcore
4783 * will be used for required_kernelcore if it's greater than
4784 * what movablecore would have allowed.
4786 if (required_movablecore) {
4787 unsigned long corepages;
4790 * Round-up so that ZONE_MOVABLE is at least as large as what
4791 * was requested by the user
4793 required_movablecore =
4794 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4795 corepages = totalpages - required_movablecore;
4797 required_kernelcore = max(required_kernelcore, corepages);
4800 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4801 if (!required_kernelcore)
4804 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4805 find_usable_zone_for_movable();
4806 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4809 /* Spread kernelcore memory as evenly as possible throughout nodes */
4810 kernelcore_node = required_kernelcore / usable_nodes;
4811 for_each_node_state(nid, N_HIGH_MEMORY) {
4813 * Recalculate kernelcore_node if the division per node
4814 * now exceeds what is necessary to satisfy the requested
4815 * amount of memory for the kernel
4817 if (required_kernelcore < kernelcore_node)
4818 kernelcore_node = required_kernelcore / usable_nodes;
4821 * As the map is walked, we track how much memory is usable
4822 * by the kernel using kernelcore_remaining. When it is
4823 * 0, the rest of the node is usable by ZONE_MOVABLE
4825 kernelcore_remaining = kernelcore_node;
4827 /* Go through each range of PFNs within this node */
4828 for_each_active_range_index_in_nid(i, nid) {
4829 unsigned long start_pfn, end_pfn;
4830 unsigned long size_pages;
4832 start_pfn = max(early_node_map[i].start_pfn,
4833 zone_movable_pfn[nid]);
4834 end_pfn = early_node_map[i].end_pfn;
4835 if (start_pfn >= end_pfn)
4838 /* Account for what is only usable for kernelcore */
4839 if (start_pfn < usable_startpfn) {
4840 unsigned long kernel_pages;
4841 kernel_pages = min(end_pfn, usable_startpfn)
4844 kernelcore_remaining -= min(kernel_pages,
4845 kernelcore_remaining);
4846 required_kernelcore -= min(kernel_pages,
4847 required_kernelcore);
4849 /* Continue if range is now fully accounted */
4850 if (end_pfn <= usable_startpfn) {
4853 * Push zone_movable_pfn to the end so
4854 * that if we have to rebalance
4855 * kernelcore across nodes, we will
4856 * not double account here
4858 zone_movable_pfn[nid] = end_pfn;
4861 start_pfn = usable_startpfn;
4865 * The usable PFN range for ZONE_MOVABLE is from
4866 * start_pfn->end_pfn. Calculate size_pages as the
4867 * number of pages used as kernelcore
4869 size_pages = end_pfn - start_pfn;
4870 if (size_pages > kernelcore_remaining)
4871 size_pages = kernelcore_remaining;
4872 zone_movable_pfn[nid] = start_pfn + size_pages;
4875 * Some kernelcore has been met, update counts and
4876 * break if the kernelcore for this node has been
4879 required_kernelcore -= min(required_kernelcore,
4881 kernelcore_remaining -= size_pages;
4882 if (!kernelcore_remaining)
4888 * If there is still required_kernelcore, we do another pass with one
4889 * less node in the count. This will push zone_movable_pfn[nid] further
4890 * along on the nodes that still have memory until kernelcore is
4894 if (usable_nodes && required_kernelcore > usable_nodes)
4897 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4898 for (nid = 0; nid < MAX_NUMNODES; nid++)
4899 zone_movable_pfn[nid] =
4900 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4903 /* restore the node_state */
4904 node_states[N_HIGH_MEMORY] = saved_node_state;
4907 /* Any regular memory on that node ? */
4908 static void check_for_regular_memory(pg_data_t *pgdat)
4910 #ifdef CONFIG_HIGHMEM
4911 enum zone_type zone_type;
4913 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
4914 struct zone *zone = &pgdat->node_zones[zone_type];
4915 if (zone->present_pages)
4916 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
4922 * free_area_init_nodes - Initialise all pg_data_t and zone data
4923 * @max_zone_pfn: an array of max PFNs for each zone
4925 * This will call free_area_init_node() for each active node in the system.
4926 * Using the page ranges provided by add_active_range(), the size of each
4927 * zone in each node and their holes is calculated. If the maximum PFN
4928 * between two adjacent zones match, it is assumed that the zone is empty.
4929 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4930 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4931 * starts where the previous one ended. For example, ZONE_DMA32 starts
4932 * at arch_max_dma_pfn.
4934 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
4939 /* Sort early_node_map as initialisation assumes it is sorted */
4942 /* Record where the zone boundaries are */
4943 memset(arch_zone_lowest_possible_pfn, 0,
4944 sizeof(arch_zone_lowest_possible_pfn));
4945 memset(arch_zone_highest_possible_pfn, 0,
4946 sizeof(arch_zone_highest_possible_pfn));
4947 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
4948 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
4949 for (i = 1; i < MAX_NR_ZONES; i++) {
4950 if (i == ZONE_MOVABLE)
4952 arch_zone_lowest_possible_pfn[i] =
4953 arch_zone_highest_possible_pfn[i-1];
4954 arch_zone_highest_possible_pfn[i] =
4955 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
4957 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
4958 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
4960 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4961 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
4962 find_zone_movable_pfns_for_nodes(zone_movable_pfn);
4964 /* Print out the zone ranges */
4965 printk("Zone PFN ranges:\n");
4966 for (i = 0; i < MAX_NR_ZONES; i++) {
4967 if (i == ZONE_MOVABLE)
4969 printk(" %-8s ", zone_names[i]);
4970 if (arch_zone_lowest_possible_pfn[i] ==
4971 arch_zone_highest_possible_pfn[i])
4974 printk("%0#10lx -> %0#10lx\n",
4975 arch_zone_lowest_possible_pfn[i],
4976 arch_zone_highest_possible_pfn[i]);
4979 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4980 printk("Movable zone start PFN for each node\n");
4981 for (i = 0; i < MAX_NUMNODES; i++) {
4982 if (zone_movable_pfn[i])
4983 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
4986 /* Print out the early_node_map[] */
4987 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
4988 for (i = 0; i < nr_nodemap_entries; i++)
4989 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4990 early_node_map[i].start_pfn,
4991 early_node_map[i].end_pfn);
4993 /* Initialise every node */
4994 mminit_verify_pageflags_layout();
4995 setup_nr_node_ids();
4996 for_each_online_node(nid) {
4997 pg_data_t *pgdat = NODE_DATA(nid);
4998 free_area_init_node(nid, NULL,
4999 find_min_pfn_for_node(nid), NULL);
5001 /* Any memory on that node */
5002 if (pgdat->node_present_pages)
5003 node_set_state(nid, N_HIGH_MEMORY);
5004 check_for_regular_memory(pgdat);
5008 static int __init cmdline_parse_core(char *p, unsigned long *core)
5010 unsigned long long coremem;
5014 coremem = memparse(p, &p);
5015 *core = coremem >> PAGE_SHIFT;
5017 /* Paranoid check that UL is enough for the coremem value */
5018 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5024 * kernelcore=size sets the amount of memory for use for allocations that
5025 * cannot be reclaimed or migrated.
5027 static int __init cmdline_parse_kernelcore(char *p)
5029 return cmdline_parse_core(p, &required_kernelcore);
5033 * movablecore=size sets the amount of memory for use for allocations that
5034 * can be reclaimed or migrated.
5036 static int __init cmdline_parse_movablecore(char *p)
5038 return cmdline_parse_core(p, &required_movablecore);
5041 early_param("kernelcore", cmdline_parse_kernelcore);
5042 early_param("movablecore", cmdline_parse_movablecore);
5044 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
5047 * set_dma_reserve - set the specified number of pages reserved in the first zone
5048 * @new_dma_reserve: The number of pages to mark reserved
5050 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5051 * In the DMA zone, a significant percentage may be consumed by kernel image
5052 * and other unfreeable allocations which can skew the watermarks badly. This
5053 * function may optionally be used to account for unfreeable pages in the
5054 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5055 * smaller per-cpu batchsize.
5057 void __init set_dma_reserve(unsigned long new_dma_reserve)
5059 dma_reserve = new_dma_reserve;
5062 void __init free_area_init(unsigned long *zones_size)
5064 free_area_init_node(0, zones_size,
5065 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5068 static int page_alloc_cpu_notify(struct notifier_block *self,
5069 unsigned long action, void *hcpu)
5071 int cpu = (unsigned long)hcpu;
5073 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5077 * Spill the event counters of the dead processor
5078 * into the current processors event counters.
5079 * This artificially elevates the count of the current
5082 vm_events_fold_cpu(cpu);
5085 * Zero the differential counters of the dead processor
5086 * so that the vm statistics are consistent.
5088 * This is only okay since the processor is dead and cannot
5089 * race with what we are doing.
5091 refresh_cpu_vm_stats(cpu);
5096 void __init page_alloc_init(void)
5098 hotcpu_notifier(page_alloc_cpu_notify, 0);
5102 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5103 * or min_free_kbytes changes.
5105 static void calculate_totalreserve_pages(void)
5107 struct pglist_data *pgdat;
5108 unsigned long reserve_pages = 0;
5109 enum zone_type i, j;
5111 for_each_online_pgdat(pgdat) {
5112 for (i = 0; i < MAX_NR_ZONES; i++) {
5113 struct zone *zone = pgdat->node_zones + i;
5114 unsigned long max = 0;
5116 /* Find valid and maximum lowmem_reserve in the zone */
5117 for (j = i; j < MAX_NR_ZONES; j++) {
5118 if (zone->lowmem_reserve[j] > max)
5119 max = zone->lowmem_reserve[j];
5122 /* we treat the high watermark as reserved pages. */
5123 max += high_wmark_pages(zone);
5125 if (max > zone->present_pages)
5126 max = zone->present_pages;
5127 reserve_pages += max;
5130 totalreserve_pages = reserve_pages;
5134 * setup_per_zone_lowmem_reserve - called whenever
5135 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5136 * has a correct pages reserved value, so an adequate number of
5137 * pages are left in the zone after a successful __alloc_pages().
5139 static void setup_per_zone_lowmem_reserve(void)
5141 struct pglist_data *pgdat;
5142 enum zone_type j, idx;
5144 for_each_online_pgdat(pgdat) {
5145 for (j = 0; j < MAX_NR_ZONES; j++) {
5146 struct zone *zone = pgdat->node_zones + j;
5147 unsigned long present_pages = zone->present_pages;
5149 zone->lowmem_reserve[j] = 0;
5153 struct zone *lower_zone;
5157 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5158 sysctl_lowmem_reserve_ratio[idx] = 1;
5160 lower_zone = pgdat->node_zones + idx;
5161 lower_zone->lowmem_reserve[j] = present_pages /
5162 sysctl_lowmem_reserve_ratio[idx];
5163 present_pages += lower_zone->present_pages;
5168 /* update totalreserve_pages */
5169 calculate_totalreserve_pages();
5173 * setup_per_zone_wmarks - called when min_free_kbytes changes
5174 * or when memory is hot-{added|removed}
5176 * Ensures that the watermark[min,low,high] values for each zone are set
5177 * correctly with respect to min_free_kbytes.
5179 void setup_per_zone_wmarks(void)
5181 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5182 unsigned long lowmem_pages = 0;
5184 unsigned long flags;
5186 /* Calculate total number of !ZONE_HIGHMEM pages */
5187 for_each_zone(zone) {
5188 if (!is_highmem(zone))
5189 lowmem_pages += zone->present_pages;
5192 for_each_zone(zone) {
5195 spin_lock_irqsave(&zone->lock, flags);
5196 tmp = (u64)pages_min * zone->present_pages;
5197 do_div(tmp, lowmem_pages);
5198 if (is_highmem(zone)) {
5200 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5201 * need highmem pages, so cap pages_min to a small
5204 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5205 * deltas controls asynch page reclaim, and so should
5206 * not be capped for highmem.
5210 min_pages = zone->present_pages / 1024;
5211 if (min_pages < SWAP_CLUSTER_MAX)
5212 min_pages = SWAP_CLUSTER_MAX;
5213 if (min_pages > 128)
5215 zone->watermark[WMARK_MIN] = min_pages;
5218 * If it's a lowmem zone, reserve a number of pages
5219 * proportionate to the zone's size.
5221 zone->watermark[WMARK_MIN] = tmp;
5224 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5225 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5226 setup_zone_migrate_reserve(zone);
5227 spin_unlock_irqrestore(&zone->lock, flags);
5230 /* update totalreserve_pages */
5231 calculate_totalreserve_pages();
5235 * The inactive anon list should be small enough that the VM never has to
5236 * do too much work, but large enough that each inactive page has a chance
5237 * to be referenced again before it is swapped out.
5239 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5240 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5241 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5242 * the anonymous pages are kept on the inactive list.
5245 * memory ratio inactive anon
5246 * -------------------------------------
5255 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5257 unsigned int gb, ratio;
5259 /* Zone size in gigabytes */
5260 gb = zone->present_pages >> (30 - PAGE_SHIFT);
5262 ratio = int_sqrt(10 * gb);
5266 zone->inactive_ratio = ratio;
5269 static void __meminit setup_per_zone_inactive_ratio(void)
5274 calculate_zone_inactive_ratio(zone);
5278 * Initialise min_free_kbytes.
5280 * For small machines we want it small (128k min). For large machines
5281 * we want it large (64MB max). But it is not linear, because network
5282 * bandwidth does not increase linearly with machine size. We use
5284 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5285 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5301 int __meminit init_per_zone_wmark_min(void)
5303 unsigned long lowmem_kbytes;
5305 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5307 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5308 if (min_free_kbytes < 128)
5309 min_free_kbytes = 128;
5310 if (min_free_kbytes > 65536)
5311 min_free_kbytes = 65536;
5312 setup_per_zone_wmarks();
5313 refresh_zone_stat_thresholds();
5314 setup_per_zone_lowmem_reserve();
5315 setup_per_zone_inactive_ratio();
5318 module_init(init_per_zone_wmark_min)
5321 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5322 * that we can call two helper functions whenever min_free_kbytes
5325 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
5326 void __user *buffer, size_t *length, loff_t *ppos)
5328 proc_dointvec(table, write, buffer, length, ppos);
5330 setup_per_zone_wmarks();
5335 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5336 void __user *buffer, size_t *length, loff_t *ppos)
5341 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5346 zone->min_unmapped_pages = (zone->present_pages *
5347 sysctl_min_unmapped_ratio) / 100;
5351 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5352 void __user *buffer, size_t *length, loff_t *ppos)
5357 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5362 zone->min_slab_pages = (zone->present_pages *
5363 sysctl_min_slab_ratio) / 100;
5369 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5370 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5371 * whenever sysctl_lowmem_reserve_ratio changes.
5373 * The reserve ratio obviously has absolutely no relation with the
5374 * minimum watermarks. The lowmem reserve ratio can only make sense
5375 * if in function of the boot time zone sizes.
5377 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5378 void __user *buffer, size_t *length, loff_t *ppos)
5380 proc_dointvec_minmax(table, write, buffer, length, ppos);
5381 setup_per_zone_lowmem_reserve();
5386 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5387 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5388 * can have before it gets flushed back to buddy allocator.
5391 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
5392 void __user *buffer, size_t *length, loff_t *ppos)
5398 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5399 if (!write || (ret == -EINVAL))
5401 for_each_populated_zone(zone) {
5402 for_each_possible_cpu(cpu) {
5404 high = zone->present_pages / percpu_pagelist_fraction;
5405 setup_pagelist_highmark(
5406 per_cpu_ptr(zone->pageset, cpu), high);
5412 int hashdist = HASHDIST_DEFAULT;
5415 static int __init set_hashdist(char *str)
5419 hashdist = simple_strtoul(str, &str, 0);
5422 __setup("hashdist=", set_hashdist);
5426 * allocate a large system hash table from bootmem
5427 * - it is assumed that the hash table must contain an exact power-of-2
5428 * quantity of entries
5429 * - limit is the number of hash buckets, not the total allocation size
5431 void *__init alloc_large_system_hash(const char *tablename,
5432 unsigned long bucketsize,
5433 unsigned long numentries,
5436 unsigned int *_hash_shift,
5437 unsigned int *_hash_mask,
5438 unsigned long limit)
5440 unsigned long long max = limit;
5441 unsigned long log2qty, size;
5444 /* allow the kernel cmdline to have a say */
5446 /* round applicable memory size up to nearest megabyte */
5447 numentries = nr_kernel_pages;
5448 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
5449 numentries >>= 20 - PAGE_SHIFT;
5450 numentries <<= 20 - PAGE_SHIFT;
5452 /* limit to 1 bucket per 2^scale bytes of low memory */
5453 if (scale > PAGE_SHIFT)
5454 numentries >>= (scale - PAGE_SHIFT);
5456 numentries <<= (PAGE_SHIFT - scale);
5458 /* Make sure we've got at least a 0-order allocation.. */
5459 if (unlikely(flags & HASH_SMALL)) {
5460 /* Makes no sense without HASH_EARLY */
5461 WARN_ON(!(flags & HASH_EARLY));
5462 if (!(numentries >> *_hash_shift)) {
5463 numentries = 1UL << *_hash_shift;
5464 BUG_ON(!numentries);
5466 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5467 numentries = PAGE_SIZE / bucketsize;
5469 numentries = roundup_pow_of_two(numentries);
5471 /* limit allocation size to 1/16 total memory by default */
5473 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5474 do_div(max, bucketsize);
5477 if (numentries > max)
5480 log2qty = ilog2(numentries);
5483 size = bucketsize << log2qty;
5484 if (flags & HASH_EARLY)
5485 table = alloc_bootmem_nopanic(size);
5487 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
5490 * If bucketsize is not a power-of-two, we may free
5491 * some pages at the end of hash table which
5492 * alloc_pages_exact() automatically does
5494 if (get_order(size) < MAX_ORDER) {
5495 table = alloc_pages_exact(size, GFP_ATOMIC);
5496 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
5499 } while (!table && size > PAGE_SIZE && --log2qty);
5502 panic("Failed to allocate %s hash table\n", tablename);
5504 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
5507 ilog2(size) - PAGE_SHIFT,
5511 *_hash_shift = log2qty;
5513 *_hash_mask = (1 << log2qty) - 1;
5518 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5519 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
5522 #ifdef CONFIG_SPARSEMEM
5523 return __pfn_to_section(pfn)->pageblock_flags;
5525 return zone->pageblock_flags;
5526 #endif /* CONFIG_SPARSEMEM */
5529 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
5531 #ifdef CONFIG_SPARSEMEM
5532 pfn &= (PAGES_PER_SECTION-1);
5533 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5535 pfn = pfn - zone->zone_start_pfn;
5536 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5537 #endif /* CONFIG_SPARSEMEM */
5541 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5542 * @page: The page within the block of interest
5543 * @start_bitidx: The first bit of interest to retrieve
5544 * @end_bitidx: The last bit of interest
5545 * returns pageblock_bits flags
5547 unsigned long get_pageblock_flags_group(struct page *page,
5548 int start_bitidx, int end_bitidx)
5551 unsigned long *bitmap;
5552 unsigned long pfn, bitidx;
5553 unsigned long flags = 0;
5554 unsigned long value = 1;
5556 zone = page_zone(page);
5557 pfn = page_to_pfn(page);
5558 bitmap = get_pageblock_bitmap(zone, pfn);
5559 bitidx = pfn_to_bitidx(zone, pfn);
5561 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5562 if (test_bit(bitidx + start_bitidx, bitmap))
5569 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5570 * @page: The page within the block of interest
5571 * @start_bitidx: The first bit of interest
5572 * @end_bitidx: The last bit of interest
5573 * @flags: The flags to set
5575 void set_pageblock_flags_group(struct page *page, unsigned long flags,
5576 int start_bitidx, int end_bitidx)
5579 unsigned long *bitmap;
5580 unsigned long pfn, bitidx;
5581 unsigned long value = 1;
5583 zone = page_zone(page);
5584 pfn = page_to_pfn(page);
5585 bitmap = get_pageblock_bitmap(zone, pfn);
5586 bitidx = pfn_to_bitidx(zone, pfn);
5587 VM_BUG_ON(pfn < zone->zone_start_pfn);
5588 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5590 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5592 __set_bit(bitidx + start_bitidx, bitmap);
5594 __clear_bit(bitidx + start_bitidx, bitmap);
5598 * This is designed as sub function...plz see page_isolation.c also.
5599 * set/clear page block's type to be ISOLATE.
5600 * page allocater never alloc memory from ISOLATE block.
5604 __count_immobile_pages(struct zone *zone, struct page *page, int count)
5606 unsigned long pfn, iter, found;
5608 * For avoiding noise data, lru_add_drain_all() should be called
5609 * If ZONE_MOVABLE, the zone never contains immobile pages
5611 if (zone_idx(zone) == ZONE_MOVABLE)
5614 if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
5617 pfn = page_to_pfn(page);
5618 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
5619 unsigned long check = pfn + iter;
5621 if (!pfn_valid_within(check))
5624 page = pfn_to_page(check);
5625 if (!page_count(page)) {
5626 if (PageBuddy(page))
5627 iter += (1 << page_order(page)) - 1;
5633 * If there are RECLAIMABLE pages, we need to check it.
5634 * But now, memory offline itself doesn't call shrink_slab()
5635 * and it still to be fixed.
5638 * If the page is not RAM, page_count()should be 0.
5639 * we don't need more check. This is an _used_ not-movable page.
5641 * The problematic thing here is PG_reserved pages. PG_reserved
5642 * is set to both of a memory hole page and a _used_ kernel
5651 bool is_pageblock_removable_nolock(struct page *page)
5653 struct zone *zone = page_zone(page);
5654 unsigned long pfn = page_to_pfn(page);
5657 * We have to be careful here because we are iterating over memory
5658 * sections which are not zone aware so we might end up outside of
5659 * the zone but still within the section.
5661 if (!zone || zone->zone_start_pfn > pfn ||
5662 zone->zone_start_pfn + zone->spanned_pages <= pfn)
5665 return __count_immobile_pages(zone, page, 0);
5668 int set_migratetype_isolate(struct page *page)
5671 unsigned long flags, pfn;
5672 struct memory_isolate_notify arg;
5676 zone = page_zone(page);
5678 spin_lock_irqsave(&zone->lock, flags);
5680 pfn = page_to_pfn(page);
5681 arg.start_pfn = pfn;
5682 arg.nr_pages = pageblock_nr_pages;
5683 arg.pages_found = 0;
5686 * It may be possible to isolate a pageblock even if the
5687 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5688 * notifier chain is used by balloon drivers to return the
5689 * number of pages in a range that are held by the balloon
5690 * driver to shrink memory. If all the pages are accounted for
5691 * by balloons, are free, or on the LRU, isolation can continue.
5692 * Later, for example, when memory hotplug notifier runs, these
5693 * pages reported as "can be isolated" should be isolated(freed)
5694 * by the balloon driver through the memory notifier chain.
5696 notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
5697 notifier_ret = notifier_to_errno(notifier_ret);
5701 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5702 * We just check MOVABLE pages.
5704 if (__count_immobile_pages(zone, page, arg.pages_found))
5708 * immobile means "not-on-lru" paes. If immobile is larger than
5709 * removable-by-driver pages reported by notifier, we'll fail.
5714 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
5715 move_freepages_block(zone, page, MIGRATE_ISOLATE);
5718 spin_unlock_irqrestore(&zone->lock, flags);
5724 void unset_migratetype_isolate(struct page *page)
5727 unsigned long flags;
5728 zone = page_zone(page);
5729 spin_lock_irqsave(&zone->lock, flags);
5730 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
5732 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
5733 move_freepages_block(zone, page, MIGRATE_MOVABLE);
5735 spin_unlock_irqrestore(&zone->lock, flags);
5738 #ifdef CONFIG_MEMORY_HOTREMOVE
5740 * All pages in the range must be isolated before calling this.
5743 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
5749 unsigned long flags;
5750 /* find the first valid pfn */
5751 for (pfn = start_pfn; pfn < end_pfn; pfn++)
5756 zone = page_zone(pfn_to_page(pfn));
5757 spin_lock_irqsave(&zone->lock, flags);
5759 while (pfn < end_pfn) {
5760 if (!pfn_valid(pfn)) {
5764 page = pfn_to_page(pfn);
5765 BUG_ON(page_count(page));
5766 BUG_ON(!PageBuddy(page));
5767 order = page_order(page);
5768 #ifdef CONFIG_DEBUG_VM
5769 printk(KERN_INFO "remove from free list %lx %d %lx\n",
5770 pfn, 1 << order, end_pfn);
5772 list_del(&page->lru);
5773 rmv_page_order(page);
5774 zone->free_area[order].nr_free--;
5775 __mod_zone_page_state(zone, NR_FREE_PAGES,
5777 for (i = 0; i < (1 << order); i++)
5778 SetPageReserved((page+i));
5779 pfn += (1 << order);
5781 spin_unlock_irqrestore(&zone->lock, flags);
5785 #ifdef CONFIG_MEMORY_FAILURE
5786 bool is_free_buddy_page(struct page *page)
5788 struct zone *zone = page_zone(page);
5789 unsigned long pfn = page_to_pfn(page);
5790 unsigned long flags;
5793 spin_lock_irqsave(&zone->lock, flags);
5794 for (order = 0; order < MAX_ORDER; order++) {
5795 struct page *page_head = page - (pfn & ((1 << order) - 1));
5797 if (PageBuddy(page_head) && page_order(page_head) >= order)
5800 spin_unlock_irqrestore(&zone->lock, flags);
5802 return order < MAX_ORDER;
5806 static struct trace_print_flags pageflag_names[] = {
5807 {1UL << PG_locked, "locked" },
5808 {1UL << PG_error, "error" },
5809 {1UL << PG_referenced, "referenced" },
5810 {1UL << PG_uptodate, "uptodate" },
5811 {1UL << PG_dirty, "dirty" },
5812 {1UL << PG_lru, "lru" },
5813 {1UL << PG_active, "active" },
5814 {1UL << PG_slab, "slab" },
5815 {1UL << PG_owner_priv_1, "owner_priv_1" },
5816 {1UL << PG_arch_1, "arch_1" },
5817 {1UL << PG_reserved, "reserved" },
5818 {1UL << PG_private, "private" },
5819 {1UL << PG_private_2, "private_2" },
5820 {1UL << PG_writeback, "writeback" },
5821 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5822 {1UL << PG_head, "head" },
5823 {1UL << PG_tail, "tail" },
5825 {1UL << PG_compound, "compound" },
5827 {1UL << PG_swapcache, "swapcache" },
5828 {1UL << PG_mappedtodisk, "mappedtodisk" },
5829 {1UL << PG_reclaim, "reclaim" },
5830 {1UL << PG_swapbacked, "swapbacked" },
5831 {1UL << PG_unevictable, "unevictable" },
5833 {1UL << PG_mlocked, "mlocked" },
5835 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5836 {1UL << PG_uncached, "uncached" },
5838 #ifdef CONFIG_MEMORY_FAILURE
5839 {1UL << PG_hwpoison, "hwpoison" },
5844 static void dump_page_flags(unsigned long flags)
5846 const char *delim = "";
5850 printk(KERN_ALERT "page flags: %#lx(", flags);
5852 /* remove zone id */
5853 flags &= (1UL << NR_PAGEFLAGS) - 1;
5855 for (i = 0; pageflag_names[i].name && flags; i++) {
5857 mask = pageflag_names[i].mask;
5858 if ((flags & mask) != mask)
5862 printk("%s%s", delim, pageflag_names[i].name);
5866 /* check for left over flags */
5868 printk("%s%#lx", delim, flags);
5873 void dump_page(struct page *page)
5876 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5877 page, atomic_read(&page->_count), page_mapcount(page),
5878 page->mapping, page->index);
5879 dump_page_flags(page->flags);
5880 mem_cgroup_print_bad_page(page);