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/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page-debug-flags.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
65 #include <asm/sections.h>
66 #include <asm/tlbflush.h>
67 #include <asm/div64.h>
70 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
71 static DEFINE_MUTEX(pcp_batch_high_lock);
72 #define MIN_PERCPU_PAGELIST_FRACTION (8)
74 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
75 DEFINE_PER_CPU(int, numa_node);
76 EXPORT_PER_CPU_SYMBOL(numa_node);
79 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
81 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
82 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
83 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
84 * defined in <linux/topology.h>.
86 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
87 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
91 * Array of node states.
93 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
94 [N_POSSIBLE] = NODE_MASK_ALL,
95 [N_ONLINE] = { { [0] = 1UL } },
97 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
99 [N_HIGH_MEMORY] = { { [0] = 1UL } },
101 #ifdef CONFIG_MOVABLE_NODE
102 [N_MEMORY] = { { [0] = 1UL } },
104 [N_CPU] = { { [0] = 1UL } },
107 EXPORT_SYMBOL(node_states);
109 /* Protect totalram_pages and zone->managed_pages */
110 static DEFINE_SPINLOCK(managed_page_count_lock);
112 unsigned long totalram_pages __read_mostly;
113 unsigned long totalreserve_pages __read_mostly;
115 * When calculating the number of globally allowed dirty pages, there
116 * is a certain number of per-zone reserves that should not be
117 * considered dirtyable memory. This is the sum of those reserves
118 * over all existing zones that contribute dirtyable memory.
120 unsigned long dirty_balance_reserve __read_mostly;
122 int percpu_pagelist_fraction;
123 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
125 #ifdef CONFIG_PM_SLEEP
127 * The following functions are used by the suspend/hibernate code to temporarily
128 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
129 * while devices are suspended. To avoid races with the suspend/hibernate code,
130 * they should always be called with pm_mutex held (gfp_allowed_mask also should
131 * only be modified with pm_mutex held, unless the suspend/hibernate code is
132 * guaranteed not to run in parallel with that modification).
135 static gfp_t saved_gfp_mask;
137 void pm_restore_gfp_mask(void)
139 WARN_ON(!mutex_is_locked(&pm_mutex));
140 if (saved_gfp_mask) {
141 gfp_allowed_mask = saved_gfp_mask;
146 void pm_restrict_gfp_mask(void)
148 WARN_ON(!mutex_is_locked(&pm_mutex));
149 WARN_ON(saved_gfp_mask);
150 saved_gfp_mask = gfp_allowed_mask;
151 gfp_allowed_mask &= ~GFP_IOFS;
154 bool pm_suspended_storage(void)
156 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
160 #endif /* CONFIG_PM_SLEEP */
162 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
163 int pageblock_order __read_mostly;
166 static void __free_pages_ok(struct page *page, unsigned int order);
169 * results with 256, 32 in the lowmem_reserve sysctl:
170 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
171 * 1G machine -> (16M dma, 784M normal, 224M high)
172 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
173 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
174 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
176 * TBD: should special case ZONE_DMA32 machines here - in those we normally
177 * don't need any ZONE_NORMAL reservation
179 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
180 #ifdef CONFIG_ZONE_DMA
183 #ifdef CONFIG_ZONE_DMA32
186 #ifdef CONFIG_HIGHMEM
192 EXPORT_SYMBOL(totalram_pages);
194 static char * const zone_names[MAX_NR_ZONES] = {
195 #ifdef CONFIG_ZONE_DMA
198 #ifdef CONFIG_ZONE_DMA32
202 #ifdef CONFIG_HIGHMEM
208 int min_free_kbytes = 1024;
209 int user_min_free_kbytes = -1;
211 static unsigned long __meminitdata nr_kernel_pages;
212 static unsigned long __meminitdata nr_all_pages;
213 static unsigned long __meminitdata dma_reserve;
215 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
216 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
217 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
218 static unsigned long __initdata required_kernelcore;
219 static unsigned long __initdata required_movablecore;
220 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
222 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
224 EXPORT_SYMBOL(movable_zone);
225 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
228 int nr_node_ids __read_mostly = MAX_NUMNODES;
229 int nr_online_nodes __read_mostly = 1;
230 EXPORT_SYMBOL(nr_node_ids);
231 EXPORT_SYMBOL(nr_online_nodes);
234 int page_group_by_mobility_disabled __read_mostly;
236 void set_pageblock_migratetype(struct page *page, int migratetype)
238 if (unlikely(page_group_by_mobility_disabled &&
239 migratetype < MIGRATE_PCPTYPES))
240 migratetype = MIGRATE_UNMOVABLE;
242 set_pageblock_flags_group(page, (unsigned long)migratetype,
243 PB_migrate, PB_migrate_end);
246 bool oom_killer_disabled __read_mostly;
248 #ifdef CONFIG_DEBUG_VM
249 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
253 unsigned long pfn = page_to_pfn(page);
254 unsigned long sp, start_pfn;
257 seq = zone_span_seqbegin(zone);
258 start_pfn = zone->zone_start_pfn;
259 sp = zone->spanned_pages;
260 if (!zone_spans_pfn(zone, pfn))
262 } while (zone_span_seqretry(zone, seq));
265 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
266 pfn, zone_to_nid(zone), zone->name,
267 start_pfn, start_pfn + sp);
272 static int page_is_consistent(struct zone *zone, struct page *page)
274 if (!pfn_valid_within(page_to_pfn(page)))
276 if (zone != page_zone(page))
282 * Temporary debugging check for pages not lying within a given zone.
284 static int bad_range(struct zone *zone, struct page *page)
286 if (page_outside_zone_boundaries(zone, page))
288 if (!page_is_consistent(zone, page))
294 static inline int bad_range(struct zone *zone, struct page *page)
300 static void bad_page(struct page *page, const char *reason,
301 unsigned long bad_flags)
303 static unsigned long resume;
304 static unsigned long nr_shown;
305 static unsigned long nr_unshown;
307 /* Don't complain about poisoned pages */
308 if (PageHWPoison(page)) {
309 page_mapcount_reset(page); /* remove PageBuddy */
314 * Allow a burst of 60 reports, then keep quiet for that minute;
315 * or allow a steady drip of one report per second.
317 if (nr_shown == 60) {
318 if (time_before(jiffies, resume)) {
324 "BUG: Bad page state: %lu messages suppressed\n",
331 resume = jiffies + 60 * HZ;
333 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
334 current->comm, page_to_pfn(page));
335 dump_page_badflags(page, reason, bad_flags);
340 /* Leave bad fields for debug, except PageBuddy could make trouble */
341 page_mapcount_reset(page); /* remove PageBuddy */
342 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
346 * Higher-order pages are called "compound pages". They are structured thusly:
348 * The first PAGE_SIZE page is called the "head page".
350 * The remaining PAGE_SIZE pages are called "tail pages".
352 * All pages have PG_compound set. All tail pages have their ->first_page
353 * pointing at the head page.
355 * The first tail page's ->lru.next holds the address of the compound page's
356 * put_page() function. Its ->lru.prev holds the order of allocation.
357 * This usage means that zero-order pages may not be compound.
360 static void free_compound_page(struct page *page)
362 __free_pages_ok(page, compound_order(page));
365 void prep_compound_page(struct page *page, unsigned long order)
368 int nr_pages = 1 << order;
370 set_compound_page_dtor(page, free_compound_page);
371 set_compound_order(page, order);
373 for (i = 1; i < nr_pages; i++) {
374 struct page *p = page + i;
375 set_page_count(p, 0);
376 p->first_page = page;
377 /* Make sure p->first_page is always valid for PageTail() */
383 /* update __split_huge_page_refcount if you change this function */
384 static int destroy_compound_page(struct page *page, unsigned long order)
387 int nr_pages = 1 << order;
390 if (unlikely(compound_order(page) != order)) {
391 bad_page(page, "wrong compound order", 0);
395 __ClearPageHead(page);
397 for (i = 1; i < nr_pages; i++) {
398 struct page *p = page + i;
400 if (unlikely(!PageTail(p))) {
401 bad_page(page, "PageTail not set", 0);
403 } else if (unlikely(p->first_page != page)) {
404 bad_page(page, "first_page not consistent", 0);
413 static inline void prep_zero_page(struct page *page, unsigned int order,
419 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
420 * and __GFP_HIGHMEM from hard or soft interrupt context.
422 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
423 for (i = 0; i < (1 << order); i++)
424 clear_highpage(page + i);
427 #ifdef CONFIG_DEBUG_PAGEALLOC
428 unsigned int _debug_guardpage_minorder;
430 static int __init debug_guardpage_minorder_setup(char *buf)
434 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
435 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
438 _debug_guardpage_minorder = res;
439 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
442 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
444 static inline void set_page_guard_flag(struct page *page)
446 __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
449 static inline void clear_page_guard_flag(struct page *page)
451 __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
454 static inline void set_page_guard_flag(struct page *page) { }
455 static inline void clear_page_guard_flag(struct page *page) { }
458 static inline void set_page_order(struct page *page, unsigned int order)
460 set_page_private(page, order);
461 __SetPageBuddy(page);
464 static inline void rmv_page_order(struct page *page)
466 __ClearPageBuddy(page);
467 set_page_private(page, 0);
471 * Locate the struct page for both the matching buddy in our
472 * pair (buddy1) and the combined O(n+1) page they form (page).
474 * 1) Any buddy B1 will have an order O twin B2 which satisfies
475 * the following equation:
477 * For example, if the starting buddy (buddy2) is #8 its order
479 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
481 * 2) Any buddy B will have an order O+1 parent P which
482 * satisfies the following equation:
485 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
487 static inline unsigned long
488 __find_buddy_index(unsigned long page_idx, unsigned int order)
490 return page_idx ^ (1 << order);
494 * This function checks whether a page is free && is the buddy
495 * we can do coalesce a page and its buddy if
496 * (a) the buddy is not in a hole &&
497 * (b) the buddy is in the buddy system &&
498 * (c) a page and its buddy have the same order &&
499 * (d) a page and its buddy are in the same zone.
501 * For recording whether a page is in the buddy system, we set ->_mapcount
502 * PAGE_BUDDY_MAPCOUNT_VALUE.
503 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
504 * serialized by zone->lock.
506 * For recording page's order, we use page_private(page).
508 static inline int page_is_buddy(struct page *page, struct page *buddy,
511 if (!pfn_valid_within(page_to_pfn(buddy)))
514 if (page_is_guard(buddy) && page_order(buddy) == order) {
515 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
517 if (page_zone_id(page) != page_zone_id(buddy))
523 if (PageBuddy(buddy) && page_order(buddy) == order) {
524 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
527 * zone check is done late to avoid uselessly
528 * calculating zone/node ids for pages that could
531 if (page_zone_id(page) != page_zone_id(buddy))
540 * Freeing function for a buddy system allocator.
542 * The concept of a buddy system is to maintain direct-mapped table
543 * (containing bit values) for memory blocks of various "orders".
544 * The bottom level table contains the map for the smallest allocatable
545 * units of memory (here, pages), and each level above it describes
546 * pairs of units from the levels below, hence, "buddies".
547 * At a high level, all that happens here is marking the table entry
548 * at the bottom level available, and propagating the changes upward
549 * as necessary, plus some accounting needed to play nicely with other
550 * parts of the VM system.
551 * At each level, we keep a list of pages, which are heads of continuous
552 * free pages of length of (1 << order) and marked with _mapcount
553 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
555 * So when we are allocating or freeing one, we can derive the state of the
556 * other. That is, if we allocate a small block, and both were
557 * free, the remainder of the region must be split into blocks.
558 * If a block is freed, and its buddy is also free, then this
559 * triggers coalescing into a block of larger size.
564 static inline void __free_one_page(struct page *page,
566 struct zone *zone, unsigned int order,
569 unsigned long page_idx;
570 unsigned long combined_idx;
571 unsigned long uninitialized_var(buddy_idx);
574 VM_BUG_ON(!zone_is_initialized(zone));
576 if (unlikely(PageCompound(page)))
577 if (unlikely(destroy_compound_page(page, order)))
580 VM_BUG_ON(migratetype == -1);
582 page_idx = pfn & ((1 << MAX_ORDER) - 1);
584 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
585 VM_BUG_ON_PAGE(bad_range(zone, page), page);
587 while (order < MAX_ORDER-1) {
588 buddy_idx = __find_buddy_index(page_idx, order);
589 buddy = page + (buddy_idx - page_idx);
590 if (!page_is_buddy(page, buddy, order))
593 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
594 * merge with it and move up one order.
596 if (page_is_guard(buddy)) {
597 clear_page_guard_flag(buddy);
598 set_page_private(page, 0);
599 __mod_zone_freepage_state(zone, 1 << order,
602 list_del(&buddy->lru);
603 zone->free_area[order].nr_free--;
604 rmv_page_order(buddy);
606 combined_idx = buddy_idx & page_idx;
607 page = page + (combined_idx - page_idx);
608 page_idx = combined_idx;
611 set_page_order(page, order);
614 * If this is not the largest possible page, check if the buddy
615 * of the next-highest order is free. If it is, it's possible
616 * that pages are being freed that will coalesce soon. In case,
617 * that is happening, add the free page to the tail of the list
618 * so it's less likely to be used soon and more likely to be merged
619 * as a higher order page
621 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
622 struct page *higher_page, *higher_buddy;
623 combined_idx = buddy_idx & page_idx;
624 higher_page = page + (combined_idx - page_idx);
625 buddy_idx = __find_buddy_index(combined_idx, order + 1);
626 higher_buddy = higher_page + (buddy_idx - combined_idx);
627 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
628 list_add_tail(&page->lru,
629 &zone->free_area[order].free_list[migratetype]);
634 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
636 zone->free_area[order].nr_free++;
639 static inline int free_pages_check(struct page *page)
641 const char *bad_reason = NULL;
642 unsigned long bad_flags = 0;
644 if (unlikely(page_mapcount(page)))
645 bad_reason = "nonzero mapcount";
646 if (unlikely(page->mapping != NULL))
647 bad_reason = "non-NULL mapping";
648 if (unlikely(atomic_read(&page->_count) != 0))
649 bad_reason = "nonzero _count";
650 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
651 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
652 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
654 if (unlikely(mem_cgroup_bad_page_check(page)))
655 bad_reason = "cgroup check failed";
656 if (unlikely(bad_reason)) {
657 bad_page(page, bad_reason, bad_flags);
660 page_cpupid_reset_last(page);
661 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
662 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
667 * Frees a number of pages from the PCP lists
668 * Assumes all pages on list are in same zone, and of same order.
669 * count is the number of pages to free.
671 * If the zone was previously in an "all pages pinned" state then look to
672 * see if this freeing clears that state.
674 * And clear the zone's pages_scanned counter, to hold off the "all pages are
675 * pinned" detection logic.
677 static void free_pcppages_bulk(struct zone *zone, int count,
678 struct per_cpu_pages *pcp)
684 spin_lock(&zone->lock);
685 zone->pages_scanned = 0;
689 struct list_head *list;
692 * Remove pages from lists in a round-robin fashion. A
693 * batch_free count is maintained that is incremented when an
694 * empty list is encountered. This is so more pages are freed
695 * off fuller lists instead of spinning excessively around empty
700 if (++migratetype == MIGRATE_PCPTYPES)
702 list = &pcp->lists[migratetype];
703 } while (list_empty(list));
705 /* This is the only non-empty list. Free them all. */
706 if (batch_free == MIGRATE_PCPTYPES)
707 batch_free = to_free;
710 int mt; /* migratetype of the to-be-freed page */
712 page = list_entry(list->prev, struct page, lru);
713 /* must delete as __free_one_page list manipulates */
714 list_del(&page->lru);
715 mt = get_freepage_migratetype(page);
716 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
717 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
718 trace_mm_page_pcpu_drain(page, 0, mt);
719 if (likely(!is_migrate_isolate_page(page))) {
720 __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
721 if (is_migrate_cma(mt))
722 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
724 } while (--to_free && --batch_free && !list_empty(list));
726 spin_unlock(&zone->lock);
729 static void free_one_page(struct zone *zone,
730 struct page *page, unsigned long pfn,
734 spin_lock(&zone->lock);
735 zone->pages_scanned = 0;
737 __free_one_page(page, pfn, zone, order, migratetype);
738 if (unlikely(!is_migrate_isolate(migratetype)))
739 __mod_zone_freepage_state(zone, 1 << order, migratetype);
740 spin_unlock(&zone->lock);
743 static bool free_pages_prepare(struct page *page, unsigned int order)
748 trace_mm_page_free(page, order);
749 kmemcheck_free_shadow(page, order);
752 page->mapping = NULL;
753 for (i = 0; i < (1 << order); i++)
754 bad += free_pages_check(page + i);
758 if (!PageHighMem(page)) {
759 debug_check_no_locks_freed(page_address(page),
761 debug_check_no_obj_freed(page_address(page),
764 arch_free_page(page, order);
765 kernel_map_pages(page, 1 << order, 0);
770 static void __free_pages_ok(struct page *page, unsigned int order)
774 unsigned long pfn = page_to_pfn(page);
776 if (!free_pages_prepare(page, order))
779 migratetype = get_pfnblock_migratetype(page, pfn);
780 local_irq_save(flags);
781 __count_vm_events(PGFREE, 1 << order);
782 set_freepage_migratetype(page, migratetype);
783 free_one_page(page_zone(page), page, pfn, order, migratetype);
784 local_irq_restore(flags);
787 void __init __free_pages_bootmem(struct page *page, unsigned int order)
789 unsigned int nr_pages = 1 << order;
790 struct page *p = page;
794 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
796 __ClearPageReserved(p);
797 set_page_count(p, 0);
799 __ClearPageReserved(p);
800 set_page_count(p, 0);
802 page_zone(page)->managed_pages += nr_pages;
803 set_page_refcounted(page);
804 __free_pages(page, order);
808 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
809 void __init init_cma_reserved_pageblock(struct page *page)
811 unsigned i = pageblock_nr_pages;
812 struct page *p = page;
815 __ClearPageReserved(p);
816 set_page_count(p, 0);
819 set_page_refcounted(page);
820 set_pageblock_migratetype(page, MIGRATE_CMA);
821 __free_pages(page, pageblock_order);
822 adjust_managed_page_count(page, pageblock_nr_pages);
827 * The order of subdivision here is critical for the IO subsystem.
828 * Please do not alter this order without good reasons and regression
829 * testing. Specifically, as large blocks of memory are subdivided,
830 * the order in which smaller blocks are delivered depends on the order
831 * they're subdivided in this function. This is the primary factor
832 * influencing the order in which pages are delivered to the IO
833 * subsystem according to empirical testing, and this is also justified
834 * by considering the behavior of a buddy system containing a single
835 * large block of memory acted on by a series of small allocations.
836 * This behavior is a critical factor in sglist merging's success.
840 static inline void expand(struct zone *zone, struct page *page,
841 int low, int high, struct free_area *area,
844 unsigned long size = 1 << high;
850 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
852 #ifdef CONFIG_DEBUG_PAGEALLOC
853 if (high < debug_guardpage_minorder()) {
855 * Mark as guard pages (or page), that will allow to
856 * merge back to allocator when buddy will be freed.
857 * Corresponding page table entries will not be touched,
858 * pages will stay not present in virtual address space
860 INIT_LIST_HEAD(&page[size].lru);
861 set_page_guard_flag(&page[size]);
862 set_page_private(&page[size], high);
863 /* Guard pages are not available for any usage */
864 __mod_zone_freepage_state(zone, -(1 << high),
869 list_add(&page[size].lru, &area->free_list[migratetype]);
871 set_page_order(&page[size], high);
876 * This page is about to be returned from the page allocator
878 static inline int check_new_page(struct page *page)
880 const char *bad_reason = NULL;
881 unsigned long bad_flags = 0;
883 if (unlikely(page_mapcount(page)))
884 bad_reason = "nonzero mapcount";
885 if (unlikely(page->mapping != NULL))
886 bad_reason = "non-NULL mapping";
887 if (unlikely(atomic_read(&page->_count) != 0))
888 bad_reason = "nonzero _count";
889 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
890 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
891 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
893 if (unlikely(mem_cgroup_bad_page_check(page)))
894 bad_reason = "cgroup check failed";
895 if (unlikely(bad_reason)) {
896 bad_page(page, bad_reason, bad_flags);
902 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags)
906 for (i = 0; i < (1 << order); i++) {
907 struct page *p = page + i;
908 if (unlikely(check_new_page(p)))
912 set_page_private(page, 0);
913 set_page_refcounted(page);
915 arch_alloc_page(page, order);
916 kernel_map_pages(page, 1 << order, 1);
918 if (gfp_flags & __GFP_ZERO)
919 prep_zero_page(page, order, gfp_flags);
921 if (order && (gfp_flags & __GFP_COMP))
922 prep_compound_page(page, order);
928 * Go through the free lists for the given migratetype and remove
929 * the smallest available page from the freelists
932 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
935 unsigned int current_order;
936 struct free_area *area;
939 /* Find a page of the appropriate size in the preferred list */
940 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
941 area = &(zone->free_area[current_order]);
942 if (list_empty(&area->free_list[migratetype]))
945 page = list_entry(area->free_list[migratetype].next,
947 list_del(&page->lru);
948 rmv_page_order(page);
950 expand(zone, page, order, current_order, area, migratetype);
951 set_freepage_migratetype(page, migratetype);
960 * This array describes the order lists are fallen back to when
961 * the free lists for the desirable migrate type are depleted
963 static int fallbacks[MIGRATE_TYPES][4] = {
964 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
965 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
967 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
968 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
970 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
972 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
973 #ifdef CONFIG_MEMORY_ISOLATION
974 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
979 * Move the free pages in a range to the free lists of the requested type.
980 * Note that start_page and end_pages are not aligned on a pageblock
981 * boundary. If alignment is required, use move_freepages_block()
983 int move_freepages(struct zone *zone,
984 struct page *start_page, struct page *end_page,
991 #ifndef CONFIG_HOLES_IN_ZONE
993 * page_zone is not safe to call in this context when
994 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
995 * anyway as we check zone boundaries in move_freepages_block().
996 * Remove at a later date when no bug reports exist related to
997 * grouping pages by mobility
999 BUG_ON(page_zone(start_page) != page_zone(end_page));
1002 for (page = start_page; page <= end_page;) {
1003 /* Make sure we are not inadvertently changing nodes */
1004 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1006 if (!pfn_valid_within(page_to_pfn(page))) {
1011 if (!PageBuddy(page)) {
1016 order = page_order(page);
1017 list_move(&page->lru,
1018 &zone->free_area[order].free_list[migratetype]);
1019 set_freepage_migratetype(page, migratetype);
1021 pages_moved += 1 << order;
1027 int move_freepages_block(struct zone *zone, struct page *page,
1030 unsigned long start_pfn, end_pfn;
1031 struct page *start_page, *end_page;
1033 start_pfn = page_to_pfn(page);
1034 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1035 start_page = pfn_to_page(start_pfn);
1036 end_page = start_page + pageblock_nr_pages - 1;
1037 end_pfn = start_pfn + pageblock_nr_pages - 1;
1039 /* Do not cross zone boundaries */
1040 if (!zone_spans_pfn(zone, start_pfn))
1042 if (!zone_spans_pfn(zone, end_pfn))
1045 return move_freepages(zone, start_page, end_page, migratetype);
1048 static void change_pageblock_range(struct page *pageblock_page,
1049 int start_order, int migratetype)
1051 int nr_pageblocks = 1 << (start_order - pageblock_order);
1053 while (nr_pageblocks--) {
1054 set_pageblock_migratetype(pageblock_page, migratetype);
1055 pageblock_page += pageblock_nr_pages;
1060 * If breaking a large block of pages, move all free pages to the preferred
1061 * allocation list. If falling back for a reclaimable kernel allocation, be
1062 * more aggressive about taking ownership of free pages.
1064 * On the other hand, never change migration type of MIGRATE_CMA pageblocks
1065 * nor move CMA pages to different free lists. We don't want unmovable pages
1066 * to be allocated from MIGRATE_CMA areas.
1068 * Returns the new migratetype of the pageblock (or the same old migratetype
1069 * if it was unchanged).
1071 static int try_to_steal_freepages(struct zone *zone, struct page *page,
1072 int start_type, int fallback_type)
1074 int current_order = page_order(page);
1077 * When borrowing from MIGRATE_CMA, we need to release the excess
1078 * buddy pages to CMA itself. We also ensure the freepage_migratetype
1079 * is set to CMA so it is returned to the correct freelist in case
1080 * the page ends up being not actually allocated from the pcp lists.
1082 if (is_migrate_cma(fallback_type))
1083 return fallback_type;
1085 /* Take ownership for orders >= pageblock_order */
1086 if (current_order >= pageblock_order) {
1087 change_pageblock_range(page, current_order, start_type);
1091 if (current_order >= pageblock_order / 2 ||
1092 start_type == MIGRATE_RECLAIMABLE ||
1093 page_group_by_mobility_disabled) {
1096 pages = move_freepages_block(zone, page, start_type);
1098 /* Claim the whole block if over half of it is free */
1099 if (pages >= (1 << (pageblock_order-1)) ||
1100 page_group_by_mobility_disabled) {
1102 set_pageblock_migratetype(page, start_type);
1108 return fallback_type;
1111 /* Remove an element from the buddy allocator from the fallback list */
1112 static inline struct page *
1113 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1115 struct free_area *area;
1116 unsigned int current_order;
1118 int migratetype, new_type, i;
1120 /* Find the largest possible block of pages in the other list */
1121 for (current_order = MAX_ORDER-1;
1122 current_order >= order && current_order <= MAX_ORDER-1;
1125 migratetype = fallbacks[start_migratetype][i];
1127 /* MIGRATE_RESERVE handled later if necessary */
1128 if (migratetype == MIGRATE_RESERVE)
1131 area = &(zone->free_area[current_order]);
1132 if (list_empty(&area->free_list[migratetype]))
1135 page = list_entry(area->free_list[migratetype].next,
1139 new_type = try_to_steal_freepages(zone, page,
1143 /* Remove the page from the freelists */
1144 list_del(&page->lru);
1145 rmv_page_order(page);
1147 expand(zone, page, order, current_order, area,
1149 /* The freepage_migratetype may differ from pageblock's
1150 * migratetype depending on the decisions in
1151 * try_to_steal_freepages. This is OK as long as it does
1152 * not differ for MIGRATE_CMA type.
1154 set_freepage_migratetype(page, new_type);
1156 trace_mm_page_alloc_extfrag(page, order, current_order,
1157 start_migratetype, migratetype, new_type);
1167 * Do the hard work of removing an element from the buddy allocator.
1168 * Call me with the zone->lock already held.
1170 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1176 page = __rmqueue_smallest(zone, order, migratetype);
1178 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1179 page = __rmqueue_fallback(zone, order, migratetype);
1182 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1183 * is used because __rmqueue_smallest is an inline function
1184 * and we want just one call site
1187 migratetype = MIGRATE_RESERVE;
1192 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1197 * Obtain a specified number of elements from the buddy allocator, all under
1198 * a single hold of the lock, for efficiency. Add them to the supplied list.
1199 * Returns the number of new pages which were placed at *list.
1201 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1202 unsigned long count, struct list_head *list,
1203 int migratetype, bool cold)
1207 spin_lock(&zone->lock);
1208 for (i = 0; i < count; ++i) {
1209 struct page *page = __rmqueue(zone, order, migratetype);
1210 if (unlikely(page == NULL))
1214 * Split buddy pages returned by expand() are received here
1215 * in physical page order. The page is added to the callers and
1216 * list and the list head then moves forward. From the callers
1217 * perspective, the linked list is ordered by page number in
1218 * some conditions. This is useful for IO devices that can
1219 * merge IO requests if the physical pages are ordered
1223 list_add(&page->lru, list);
1225 list_add_tail(&page->lru, list);
1227 if (is_migrate_cma(get_freepage_migratetype(page)))
1228 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1231 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1232 spin_unlock(&zone->lock);
1238 * Called from the vmstat counter updater to drain pagesets of this
1239 * currently executing processor on remote nodes after they have
1242 * Note that this function must be called with the thread pinned to
1243 * a single processor.
1245 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1247 unsigned long flags;
1249 unsigned long batch;
1251 local_irq_save(flags);
1252 batch = ACCESS_ONCE(pcp->batch);
1253 if (pcp->count >= batch)
1256 to_drain = pcp->count;
1258 free_pcppages_bulk(zone, to_drain, pcp);
1259 pcp->count -= to_drain;
1261 local_irq_restore(flags);
1266 * Drain pages of the indicated processor.
1268 * The processor must either be the current processor and the
1269 * thread pinned to the current processor or a processor that
1272 static void drain_pages(unsigned int cpu)
1274 unsigned long flags;
1277 for_each_populated_zone(zone) {
1278 struct per_cpu_pageset *pset;
1279 struct per_cpu_pages *pcp;
1281 local_irq_save(flags);
1282 pset = per_cpu_ptr(zone->pageset, cpu);
1286 free_pcppages_bulk(zone, pcp->count, pcp);
1289 local_irq_restore(flags);
1294 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1296 void drain_local_pages(void *arg)
1298 drain_pages(smp_processor_id());
1302 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1304 * Note that this code is protected against sending an IPI to an offline
1305 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1306 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1307 * nothing keeps CPUs from showing up after we populated the cpumask and
1308 * before the call to on_each_cpu_mask().
1310 void drain_all_pages(void)
1313 struct per_cpu_pageset *pcp;
1317 * Allocate in the BSS so we wont require allocation in
1318 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1320 static cpumask_t cpus_with_pcps;
1323 * We don't care about racing with CPU hotplug event
1324 * as offline notification will cause the notified
1325 * cpu to drain that CPU pcps and on_each_cpu_mask
1326 * disables preemption as part of its processing
1328 for_each_online_cpu(cpu) {
1329 bool has_pcps = false;
1330 for_each_populated_zone(zone) {
1331 pcp = per_cpu_ptr(zone->pageset, cpu);
1332 if (pcp->pcp.count) {
1338 cpumask_set_cpu(cpu, &cpus_with_pcps);
1340 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1342 on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
1345 #ifdef CONFIG_HIBERNATION
1347 void mark_free_pages(struct zone *zone)
1349 unsigned long pfn, max_zone_pfn;
1350 unsigned long flags;
1351 unsigned int order, t;
1352 struct list_head *curr;
1354 if (zone_is_empty(zone))
1357 spin_lock_irqsave(&zone->lock, flags);
1359 max_zone_pfn = zone_end_pfn(zone);
1360 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1361 if (pfn_valid(pfn)) {
1362 struct page *page = pfn_to_page(pfn);
1364 if (!swsusp_page_is_forbidden(page))
1365 swsusp_unset_page_free(page);
1368 for_each_migratetype_order(order, t) {
1369 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1372 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1373 for (i = 0; i < (1UL << order); i++)
1374 swsusp_set_page_free(pfn_to_page(pfn + i));
1377 spin_unlock_irqrestore(&zone->lock, flags);
1379 #endif /* CONFIG_PM */
1382 * Free a 0-order page
1383 * cold == true ? free a cold page : free a hot page
1385 void free_hot_cold_page(struct page *page, bool cold)
1387 struct zone *zone = page_zone(page);
1388 struct per_cpu_pages *pcp;
1389 unsigned long flags;
1390 unsigned long pfn = page_to_pfn(page);
1393 if (!free_pages_prepare(page, 0))
1396 migratetype = get_pfnblock_migratetype(page, pfn);
1397 set_freepage_migratetype(page, migratetype);
1398 local_irq_save(flags);
1399 __count_vm_event(PGFREE);
1402 * We only track unmovable, reclaimable and movable on pcp lists.
1403 * Free ISOLATE pages back to the allocator because they are being
1404 * offlined but treat RESERVE as movable pages so we can get those
1405 * areas back if necessary. Otherwise, we may have to free
1406 * excessively into the page allocator
1408 if (migratetype >= MIGRATE_PCPTYPES) {
1409 if (unlikely(is_migrate_isolate(migratetype))) {
1410 free_one_page(zone, page, pfn, 0, migratetype);
1413 migratetype = MIGRATE_MOVABLE;
1416 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1418 list_add(&page->lru, &pcp->lists[migratetype]);
1420 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1422 if (pcp->count >= pcp->high) {
1423 unsigned long batch = ACCESS_ONCE(pcp->batch);
1424 free_pcppages_bulk(zone, batch, pcp);
1425 pcp->count -= batch;
1429 local_irq_restore(flags);
1433 * Free a list of 0-order pages
1435 void free_hot_cold_page_list(struct list_head *list, bool cold)
1437 struct page *page, *next;
1439 list_for_each_entry_safe(page, next, list, lru) {
1440 trace_mm_page_free_batched(page, cold);
1441 free_hot_cold_page(page, cold);
1446 * split_page takes a non-compound higher-order page, and splits it into
1447 * n (1<<order) sub-pages: page[0..n]
1448 * Each sub-page must be freed individually.
1450 * Note: this is probably too low level an operation for use in drivers.
1451 * Please consult with lkml before using this in your driver.
1453 void split_page(struct page *page, unsigned int order)
1457 VM_BUG_ON_PAGE(PageCompound(page), page);
1458 VM_BUG_ON_PAGE(!page_count(page), page);
1460 #ifdef CONFIG_KMEMCHECK
1462 * Split shadow pages too, because free(page[0]) would
1463 * otherwise free the whole shadow.
1465 if (kmemcheck_page_is_tracked(page))
1466 split_page(virt_to_page(page[0].shadow), order);
1469 for (i = 1; i < (1 << order); i++)
1470 set_page_refcounted(page + i);
1472 EXPORT_SYMBOL_GPL(split_page);
1474 static int __isolate_free_page(struct page *page, unsigned int order)
1476 unsigned long watermark;
1480 BUG_ON(!PageBuddy(page));
1482 zone = page_zone(page);
1483 mt = get_pageblock_migratetype(page);
1485 if (!is_migrate_isolate(mt)) {
1486 /* Obey watermarks as if the page was being allocated */
1487 watermark = low_wmark_pages(zone) + (1 << order);
1488 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1491 __mod_zone_freepage_state(zone, -(1UL << order), mt);
1494 /* Remove page from free list */
1495 list_del(&page->lru);
1496 zone->free_area[order].nr_free--;
1497 rmv_page_order(page);
1499 /* Set the pageblock if the isolated page is at least a pageblock */
1500 if (order >= pageblock_order - 1) {
1501 struct page *endpage = page + (1 << order) - 1;
1502 for (; page < endpage; page += pageblock_nr_pages) {
1503 int mt = get_pageblock_migratetype(page);
1504 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
1505 set_pageblock_migratetype(page,
1510 return 1UL << order;
1514 * Similar to split_page except the page is already free. As this is only
1515 * being used for migration, the migratetype of the block also changes.
1516 * As this is called with interrupts disabled, the caller is responsible
1517 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1520 * Note: this is probably too low level an operation for use in drivers.
1521 * Please consult with lkml before using this in your driver.
1523 int split_free_page(struct page *page)
1528 order = page_order(page);
1530 nr_pages = __isolate_free_page(page, order);
1534 /* Split into individual pages */
1535 set_page_refcounted(page);
1536 split_page(page, order);
1541 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1542 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1546 struct page *buffered_rmqueue(struct zone *preferred_zone,
1547 struct zone *zone, unsigned int order,
1548 gfp_t gfp_flags, int migratetype)
1550 unsigned long flags;
1552 bool cold = ((gfp_flags & __GFP_COLD) != 0);
1555 if (likely(order == 0)) {
1556 struct per_cpu_pages *pcp;
1557 struct list_head *list;
1559 local_irq_save(flags);
1560 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1561 list = &pcp->lists[migratetype];
1562 if (list_empty(list)) {
1563 pcp->count += rmqueue_bulk(zone, 0,
1566 if (unlikely(list_empty(list)))
1571 page = list_entry(list->prev, struct page, lru);
1573 page = list_entry(list->next, struct page, lru);
1575 list_del(&page->lru);
1578 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1580 * __GFP_NOFAIL is not to be used in new code.
1582 * All __GFP_NOFAIL callers should be fixed so that they
1583 * properly detect and handle allocation failures.
1585 * We most definitely don't want callers attempting to
1586 * allocate greater than order-1 page units with
1589 WARN_ON_ONCE(order > 1);
1591 spin_lock_irqsave(&zone->lock, flags);
1592 page = __rmqueue(zone, order, migratetype);
1593 spin_unlock(&zone->lock);
1596 __mod_zone_freepage_state(zone, -(1 << order),
1597 get_freepage_migratetype(page));
1600 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
1602 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1603 zone_statistics(preferred_zone, zone, gfp_flags);
1604 local_irq_restore(flags);
1606 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1607 if (prep_new_page(page, order, gfp_flags))
1612 local_irq_restore(flags);
1616 #ifdef CONFIG_FAIL_PAGE_ALLOC
1619 struct fault_attr attr;
1621 u32 ignore_gfp_highmem;
1622 u32 ignore_gfp_wait;
1624 } fail_page_alloc = {
1625 .attr = FAULT_ATTR_INITIALIZER,
1626 .ignore_gfp_wait = 1,
1627 .ignore_gfp_highmem = 1,
1631 static int __init setup_fail_page_alloc(char *str)
1633 return setup_fault_attr(&fail_page_alloc.attr, str);
1635 __setup("fail_page_alloc=", setup_fail_page_alloc);
1637 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1639 if (order < fail_page_alloc.min_order)
1641 if (gfp_mask & __GFP_NOFAIL)
1643 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1645 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1648 return should_fail(&fail_page_alloc.attr, 1 << order);
1651 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1653 static int __init fail_page_alloc_debugfs(void)
1655 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1658 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1659 &fail_page_alloc.attr);
1661 return PTR_ERR(dir);
1663 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1664 &fail_page_alloc.ignore_gfp_wait))
1666 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1667 &fail_page_alloc.ignore_gfp_highmem))
1669 if (!debugfs_create_u32("min-order", mode, dir,
1670 &fail_page_alloc.min_order))
1675 debugfs_remove_recursive(dir);
1680 late_initcall(fail_page_alloc_debugfs);
1682 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1684 #else /* CONFIG_FAIL_PAGE_ALLOC */
1686 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1691 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1694 * Return true if free pages are above 'mark'. This takes into account the order
1695 * of the allocation.
1697 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
1698 unsigned long mark, int classzone_idx, int alloc_flags,
1701 /* free_pages my go negative - that's OK */
1703 long lowmem_reserve = z->lowmem_reserve[classzone_idx];
1707 free_pages -= (1 << order) - 1;
1708 if (alloc_flags & ALLOC_HIGH)
1710 if (alloc_flags & ALLOC_HARDER)
1713 /* If allocation can't use CMA areas don't use free CMA pages */
1714 if (!(alloc_flags & ALLOC_CMA))
1715 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
1718 if (free_pages - free_cma <= min + lowmem_reserve)
1720 for (o = 0; o < order; o++) {
1721 /* At the next order, this order's pages become unavailable */
1722 free_pages -= z->free_area[o].nr_free << o;
1724 /* Require fewer higher order pages to be free */
1727 if (free_pages <= min)
1733 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1734 int classzone_idx, int alloc_flags)
1736 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1737 zone_page_state(z, NR_FREE_PAGES));
1740 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1741 unsigned long mark, int classzone_idx, int alloc_flags)
1743 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1745 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1746 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1748 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1754 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1755 * skip over zones that are not allowed by the cpuset, or that have
1756 * been recently (in last second) found to be nearly full. See further
1757 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1758 * that have to skip over a lot of full or unallowed zones.
1760 * If the zonelist cache is present in the passed zonelist, then
1761 * returns a pointer to the allowed node mask (either the current
1762 * tasks mems_allowed, or node_states[N_MEMORY].)
1764 * If the zonelist cache is not available for this zonelist, does
1765 * nothing and returns NULL.
1767 * If the fullzones BITMAP in the zonelist cache is stale (more than
1768 * a second since last zap'd) then we zap it out (clear its bits.)
1770 * We hold off even calling zlc_setup, until after we've checked the
1771 * first zone in the zonelist, on the theory that most allocations will
1772 * be satisfied from that first zone, so best to examine that zone as
1773 * quickly as we can.
1775 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1777 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1778 nodemask_t *allowednodes; /* zonelist_cache approximation */
1780 zlc = zonelist->zlcache_ptr;
1784 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1785 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1786 zlc->last_full_zap = jiffies;
1789 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1790 &cpuset_current_mems_allowed :
1791 &node_states[N_MEMORY];
1792 return allowednodes;
1796 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1797 * if it is worth looking at further for free memory:
1798 * 1) Check that the zone isn't thought to be full (doesn't have its
1799 * bit set in the zonelist_cache fullzones BITMAP).
1800 * 2) Check that the zones node (obtained from the zonelist_cache
1801 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1802 * Return true (non-zero) if zone is worth looking at further, or
1803 * else return false (zero) if it is not.
1805 * This check -ignores- the distinction between various watermarks,
1806 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1807 * found to be full for any variation of these watermarks, it will
1808 * be considered full for up to one second by all requests, unless
1809 * we are so low on memory on all allowed nodes that we are forced
1810 * into the second scan of the zonelist.
1812 * In the second scan we ignore this zonelist cache and exactly
1813 * apply the watermarks to all zones, even it is slower to do so.
1814 * We are low on memory in the second scan, and should leave no stone
1815 * unturned looking for a free page.
1817 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1818 nodemask_t *allowednodes)
1820 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1821 int i; /* index of *z in zonelist zones */
1822 int n; /* node that zone *z is on */
1824 zlc = zonelist->zlcache_ptr;
1828 i = z - zonelist->_zonerefs;
1831 /* This zone is worth trying if it is allowed but not full */
1832 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1836 * Given 'z' scanning a zonelist, set the corresponding bit in
1837 * zlc->fullzones, so that subsequent attempts to allocate a page
1838 * from that zone don't waste time re-examining it.
1840 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1842 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1843 int i; /* index of *z in zonelist zones */
1845 zlc = zonelist->zlcache_ptr;
1849 i = z - zonelist->_zonerefs;
1851 set_bit(i, zlc->fullzones);
1855 * clear all zones full, called after direct reclaim makes progress so that
1856 * a zone that was recently full is not skipped over for up to a second
1858 static void zlc_clear_zones_full(struct zonelist *zonelist)
1860 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1862 zlc = zonelist->zlcache_ptr;
1866 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1869 static bool zone_local(struct zone *local_zone, struct zone *zone)
1871 return local_zone->node == zone->node;
1874 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1876 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
1880 #else /* CONFIG_NUMA */
1882 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1887 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1888 nodemask_t *allowednodes)
1893 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1897 static void zlc_clear_zones_full(struct zonelist *zonelist)
1901 static bool zone_local(struct zone *local_zone, struct zone *zone)
1906 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1911 #endif /* CONFIG_NUMA */
1914 * get_page_from_freelist goes through the zonelist trying to allocate
1917 static struct page *
1918 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1919 struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1920 struct zone *preferred_zone, int classzone_idx, int migratetype)
1923 struct page *page = NULL;
1925 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1926 int zlc_active = 0; /* set if using zonelist_cache */
1927 int did_zlc_setup = 0; /* just call zlc_setup() one time */
1928 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
1929 (gfp_mask & __GFP_WRITE);
1933 * Scan zonelist, looking for a zone with enough free.
1934 * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
1936 for_each_zone_zonelist_nodemask(zone, z, zonelist,
1937 high_zoneidx, nodemask) {
1940 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1941 !zlc_zone_worth_trying(zonelist, z, allowednodes))
1943 if (cpusets_enabled() &&
1944 (alloc_flags & ALLOC_CPUSET) &&
1945 !cpuset_zone_allowed_softwall(zone, gfp_mask))
1948 * Distribute pages in proportion to the individual
1949 * zone size to ensure fair page aging. The zone a
1950 * page was allocated in should have no effect on the
1951 * time the page has in memory before being reclaimed.
1953 if (alloc_flags & ALLOC_FAIR) {
1954 if (!zone_local(preferred_zone, zone))
1956 if (zone_page_state(zone, NR_ALLOC_BATCH) <= 0)
1960 * When allocating a page cache page for writing, we
1961 * want to get it from a zone that is within its dirty
1962 * limit, such that no single zone holds more than its
1963 * proportional share of globally allowed dirty pages.
1964 * The dirty limits take into account the zone's
1965 * lowmem reserves and high watermark so that kswapd
1966 * should be able to balance it without having to
1967 * write pages from its LRU list.
1969 * This may look like it could increase pressure on
1970 * lower zones by failing allocations in higher zones
1971 * before they are full. But the pages that do spill
1972 * over are limited as the lower zones are protected
1973 * by this very same mechanism. It should not become
1974 * a practical burden to them.
1976 * XXX: For now, allow allocations to potentially
1977 * exceed the per-zone dirty limit in the slowpath
1978 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1979 * which is important when on a NUMA setup the allowed
1980 * zones are together not big enough to reach the
1981 * global limit. The proper fix for these situations
1982 * will require awareness of zones in the
1983 * dirty-throttling and the flusher threads.
1985 if (consider_zone_dirty && !zone_dirty_ok(zone))
1988 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1989 if (!zone_watermark_ok(zone, order, mark,
1990 classzone_idx, alloc_flags)) {
1993 /* Checked here to keep the fast path fast */
1994 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
1995 if (alloc_flags & ALLOC_NO_WATERMARKS)
1998 if (IS_ENABLED(CONFIG_NUMA) &&
1999 !did_zlc_setup && nr_online_nodes > 1) {
2001 * we do zlc_setup if there are multiple nodes
2002 * and before considering the first zone allowed
2005 allowednodes = zlc_setup(zonelist, alloc_flags);
2010 if (zone_reclaim_mode == 0 ||
2011 !zone_allows_reclaim(preferred_zone, zone))
2012 goto this_zone_full;
2015 * As we may have just activated ZLC, check if the first
2016 * eligible zone has failed zone_reclaim recently.
2018 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2019 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2022 ret = zone_reclaim(zone, gfp_mask, order);
2024 case ZONE_RECLAIM_NOSCAN:
2027 case ZONE_RECLAIM_FULL:
2028 /* scanned but unreclaimable */
2031 /* did we reclaim enough */
2032 if (zone_watermark_ok(zone, order, mark,
2033 classzone_idx, alloc_flags))
2037 * Failed to reclaim enough to meet watermark.
2038 * Only mark the zone full if checking the min
2039 * watermark or if we failed to reclaim just
2040 * 1<<order pages or else the page allocator
2041 * fastpath will prematurely mark zones full
2042 * when the watermark is between the low and
2045 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2046 ret == ZONE_RECLAIM_SOME)
2047 goto this_zone_full;
2054 page = buffered_rmqueue(preferred_zone, zone, order,
2055 gfp_mask, migratetype);
2059 if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
2060 zlc_mark_zone_full(zonelist, z);
2063 if (unlikely(IS_ENABLED(CONFIG_NUMA) && page == NULL && zlc_active)) {
2064 /* Disable zlc cache for second zonelist scan */
2071 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
2072 * necessary to allocate the page. The expectation is
2073 * that the caller is taking steps that will free more
2074 * memory. The caller should avoid the page being used
2075 * for !PFMEMALLOC purposes.
2077 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
2083 * Large machines with many possible nodes should not always dump per-node
2084 * meminfo in irq context.
2086 static inline bool should_suppress_show_mem(void)
2091 ret = in_interrupt();
2096 static DEFINE_RATELIMIT_STATE(nopage_rs,
2097 DEFAULT_RATELIMIT_INTERVAL,
2098 DEFAULT_RATELIMIT_BURST);
2100 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2102 unsigned int filter = SHOW_MEM_FILTER_NODES;
2104 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2105 debug_guardpage_minorder() > 0)
2109 * This documents exceptions given to allocations in certain
2110 * contexts that are allowed to allocate outside current's set
2113 if (!(gfp_mask & __GFP_NOMEMALLOC))
2114 if (test_thread_flag(TIF_MEMDIE) ||
2115 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2116 filter &= ~SHOW_MEM_FILTER_NODES;
2117 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2118 filter &= ~SHOW_MEM_FILTER_NODES;
2121 struct va_format vaf;
2124 va_start(args, fmt);
2129 pr_warn("%pV", &vaf);
2134 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2135 current->comm, order, gfp_mask);
2138 if (!should_suppress_show_mem())
2143 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2144 unsigned long did_some_progress,
2145 unsigned long pages_reclaimed)
2147 /* Do not loop if specifically requested */
2148 if (gfp_mask & __GFP_NORETRY)
2151 /* Always retry if specifically requested */
2152 if (gfp_mask & __GFP_NOFAIL)
2156 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2157 * making forward progress without invoking OOM. Suspend also disables
2158 * storage devices so kswapd will not help. Bail if we are suspending.
2160 if (!did_some_progress && pm_suspended_storage())
2164 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2165 * means __GFP_NOFAIL, but that may not be true in other
2168 if (order <= PAGE_ALLOC_COSTLY_ORDER)
2172 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2173 * specified, then we retry until we no longer reclaim any pages
2174 * (above), or we've reclaimed an order of pages at least as
2175 * large as the allocation's order. In both cases, if the
2176 * allocation still fails, we stop retrying.
2178 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
2184 static inline struct page *
2185 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2186 struct zonelist *zonelist, enum zone_type high_zoneidx,
2187 nodemask_t *nodemask, struct zone *preferred_zone,
2188 int classzone_idx, int migratetype)
2192 /* Acquire the OOM killer lock for the zones in zonelist */
2193 if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
2194 schedule_timeout_uninterruptible(1);
2199 * Go through the zonelist yet one more time, keep very high watermark
2200 * here, this is only to catch a parallel oom killing, we must fail if
2201 * we're still under heavy pressure.
2203 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
2204 order, zonelist, high_zoneidx,
2205 ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2206 preferred_zone, classzone_idx, migratetype);
2210 if (!(gfp_mask & __GFP_NOFAIL)) {
2211 /* The OOM killer will not help higher order allocs */
2212 if (order > PAGE_ALLOC_COSTLY_ORDER)
2214 /* The OOM killer does not needlessly kill tasks for lowmem */
2215 if (high_zoneidx < ZONE_NORMAL)
2218 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2219 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2220 * The caller should handle page allocation failure by itself if
2221 * it specifies __GFP_THISNODE.
2222 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2224 if (gfp_mask & __GFP_THISNODE)
2227 /* Exhausted what can be done so it's blamo time */
2228 out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2231 clear_zonelist_oom(zonelist, gfp_mask);
2235 #ifdef CONFIG_COMPACTION
2236 /* Try memory compaction for high-order allocations before reclaim */
2237 static struct page *
2238 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2239 struct zonelist *zonelist, enum zone_type high_zoneidx,
2240 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2241 int classzone_idx, int migratetype, enum migrate_mode mode,
2242 bool *contended_compaction, bool *deferred_compaction,
2243 unsigned long *did_some_progress)
2248 if (compaction_deferred(preferred_zone, order)) {
2249 *deferred_compaction = true;
2253 current->flags |= PF_MEMALLOC;
2254 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2256 contended_compaction);
2257 current->flags &= ~PF_MEMALLOC;
2259 if (*did_some_progress != COMPACT_SKIPPED) {
2262 /* Page migration frees to the PCP lists but we want merging */
2263 drain_pages(get_cpu());
2266 page = get_page_from_freelist(gfp_mask, nodemask,
2267 order, zonelist, high_zoneidx,
2268 alloc_flags & ~ALLOC_NO_WATERMARKS,
2269 preferred_zone, classzone_idx, migratetype);
2271 preferred_zone->compact_blockskip_flush = false;
2272 compaction_defer_reset(preferred_zone, order, true);
2273 count_vm_event(COMPACTSUCCESS);
2278 * It's bad if compaction run occurs and fails.
2279 * The most likely reason is that pages exist,
2280 * but not enough to satisfy watermarks.
2282 count_vm_event(COMPACTFAIL);
2285 * As async compaction considers a subset of pageblocks, only
2286 * defer if the failure was a sync compaction failure.
2288 if (mode != MIGRATE_ASYNC)
2289 defer_compaction(preferred_zone, order);
2297 static inline struct page *
2298 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2299 struct zonelist *zonelist, enum zone_type high_zoneidx,
2300 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2301 int classzone_idx, int migratetype,
2302 enum migrate_mode mode, bool *contended_compaction,
2303 bool *deferred_compaction, unsigned long *did_some_progress)
2307 #endif /* CONFIG_COMPACTION */
2309 /* Perform direct synchronous page reclaim */
2311 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
2312 nodemask_t *nodemask)
2314 struct reclaim_state reclaim_state;
2319 /* We now go into synchronous reclaim */
2320 cpuset_memory_pressure_bump();
2321 current->flags |= PF_MEMALLOC;
2322 lockdep_set_current_reclaim_state(gfp_mask);
2323 reclaim_state.reclaimed_slab = 0;
2324 current->reclaim_state = &reclaim_state;
2326 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2328 current->reclaim_state = NULL;
2329 lockdep_clear_current_reclaim_state();
2330 current->flags &= ~PF_MEMALLOC;
2337 /* The really slow allocator path where we enter direct reclaim */
2338 static inline struct page *
2339 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2340 struct zonelist *zonelist, enum zone_type high_zoneidx,
2341 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2342 int classzone_idx, int migratetype, unsigned long *did_some_progress)
2344 struct page *page = NULL;
2345 bool drained = false;
2347 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
2349 if (unlikely(!(*did_some_progress)))
2352 /* After successful reclaim, reconsider all zones for allocation */
2353 if (IS_ENABLED(CONFIG_NUMA))
2354 zlc_clear_zones_full(zonelist);
2357 page = get_page_from_freelist(gfp_mask, nodemask, order,
2358 zonelist, high_zoneidx,
2359 alloc_flags & ~ALLOC_NO_WATERMARKS,
2360 preferred_zone, classzone_idx,
2364 * If an allocation failed after direct reclaim, it could be because
2365 * pages are pinned on the per-cpu lists. Drain them and try again
2367 if (!page && !drained) {
2377 * This is called in the allocator slow-path if the allocation request is of
2378 * sufficient urgency to ignore watermarks and take other desperate measures
2380 static inline struct page *
2381 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2382 struct zonelist *zonelist, enum zone_type high_zoneidx,
2383 nodemask_t *nodemask, struct zone *preferred_zone,
2384 int classzone_idx, int migratetype)
2389 page = get_page_from_freelist(gfp_mask, nodemask, order,
2390 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2391 preferred_zone, classzone_idx, migratetype);
2393 if (!page && gfp_mask & __GFP_NOFAIL)
2394 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2395 } while (!page && (gfp_mask & __GFP_NOFAIL));
2400 static void reset_alloc_batches(struct zonelist *zonelist,
2401 enum zone_type high_zoneidx,
2402 struct zone *preferred_zone)
2407 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
2409 * Only reset the batches of zones that were actually
2410 * considered in the fairness pass, we don't want to
2411 * trash fairness information for zones that are not
2412 * actually part of this zonelist's round-robin cycle.
2414 if (!zone_local(preferred_zone, zone))
2416 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2417 high_wmark_pages(zone) - low_wmark_pages(zone) -
2418 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2422 static void wake_all_kswapds(unsigned int order,
2423 struct zonelist *zonelist,
2424 enum zone_type high_zoneidx,
2425 struct zone *preferred_zone)
2430 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2431 wakeup_kswapd(zone, order, zone_idx(preferred_zone));
2435 gfp_to_alloc_flags(gfp_t gfp_mask)
2437 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2438 const gfp_t wait = gfp_mask & __GFP_WAIT;
2440 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2441 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2444 * The caller may dip into page reserves a bit more if the caller
2445 * cannot run direct reclaim, or if the caller has realtime scheduling
2446 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2447 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2449 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2453 * Not worth trying to allocate harder for
2454 * __GFP_NOMEMALLOC even if it can't schedule.
2456 if (!(gfp_mask & __GFP_NOMEMALLOC))
2457 alloc_flags |= ALLOC_HARDER;
2459 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2460 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2462 alloc_flags &= ~ALLOC_CPUSET;
2463 } else if (unlikely(rt_task(current)) && !in_interrupt())
2464 alloc_flags |= ALLOC_HARDER;
2466 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2467 if (gfp_mask & __GFP_MEMALLOC)
2468 alloc_flags |= ALLOC_NO_WATERMARKS;
2469 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2470 alloc_flags |= ALLOC_NO_WATERMARKS;
2471 else if (!in_interrupt() &&
2472 ((current->flags & PF_MEMALLOC) ||
2473 unlikely(test_thread_flag(TIF_MEMDIE))))
2474 alloc_flags |= ALLOC_NO_WATERMARKS;
2477 if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2478 alloc_flags |= ALLOC_CMA;
2483 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2485 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2488 static inline struct page *
2489 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2490 struct zonelist *zonelist, enum zone_type high_zoneidx,
2491 nodemask_t *nodemask, struct zone *preferred_zone,
2492 int classzone_idx, int migratetype)
2494 const gfp_t wait = gfp_mask & __GFP_WAIT;
2495 struct page *page = NULL;
2497 unsigned long pages_reclaimed = 0;
2498 unsigned long did_some_progress;
2499 enum migrate_mode migration_mode = MIGRATE_ASYNC;
2500 bool deferred_compaction = false;
2501 bool contended_compaction = false;
2504 * In the slowpath, we sanity check order to avoid ever trying to
2505 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2506 * be using allocators in order of preference for an area that is
2509 if (order >= MAX_ORDER) {
2510 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2515 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2516 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2517 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2518 * using a larger set of nodes after it has established that the
2519 * allowed per node queues are empty and that nodes are
2522 if (IS_ENABLED(CONFIG_NUMA) &&
2523 (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2527 if (!(gfp_mask & __GFP_NO_KSWAPD))
2528 wake_all_kswapds(order, zonelist, high_zoneidx, preferred_zone);
2531 * OK, we're below the kswapd watermark and have kicked background
2532 * reclaim. Now things get more complex, so set up alloc_flags according
2533 * to how we want to proceed.
2535 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2538 * Find the true preferred zone if the allocation is unconstrained by
2541 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) {
2542 struct zoneref *preferred_zoneref;
2543 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
2544 NULL, &preferred_zone);
2545 classzone_idx = zonelist_zone_idx(preferred_zoneref);
2549 /* This is the last chance, in general, before the goto nopage. */
2550 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2551 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2552 preferred_zone, classzone_idx, migratetype);
2556 /* Allocate without watermarks if the context allows */
2557 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2559 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2560 * the allocation is high priority and these type of
2561 * allocations are system rather than user orientated
2563 zonelist = node_zonelist(numa_node_id(), gfp_mask);
2565 page = __alloc_pages_high_priority(gfp_mask, order,
2566 zonelist, high_zoneidx, nodemask,
2567 preferred_zone, classzone_idx, migratetype);
2573 /* Atomic allocations - we can't balance anything */
2576 * All existing users of the deprecated __GFP_NOFAIL are
2577 * blockable, so warn of any new users that actually allow this
2578 * type of allocation to fail.
2580 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
2584 /* Avoid recursion of direct reclaim */
2585 if (current->flags & PF_MEMALLOC)
2588 /* Avoid allocations with no watermarks from looping endlessly */
2589 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2593 * Try direct compaction. The first pass is asynchronous. Subsequent
2594 * attempts after direct reclaim are synchronous
2596 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
2597 high_zoneidx, nodemask, alloc_flags,
2599 classzone_idx, migratetype,
2600 migration_mode, &contended_compaction,
2601 &deferred_compaction,
2602 &did_some_progress);
2607 * It can become very expensive to allocate transparent hugepages at
2608 * fault, so use asynchronous memory compaction for THP unless it is
2609 * khugepaged trying to collapse.
2611 if (!(gfp_mask & __GFP_NO_KSWAPD) || (current->flags & PF_KTHREAD))
2612 migration_mode = MIGRATE_SYNC_LIGHT;
2615 * If compaction is deferred for high-order allocations, it is because
2616 * sync compaction recently failed. In this is the case and the caller
2617 * requested a movable allocation that does not heavily disrupt the
2618 * system then fail the allocation instead of entering direct reclaim.
2620 if ((deferred_compaction || contended_compaction) &&
2621 (gfp_mask & __GFP_NO_KSWAPD))
2624 /* Try direct reclaim and then allocating */
2625 page = __alloc_pages_direct_reclaim(gfp_mask, order,
2626 zonelist, high_zoneidx,
2628 alloc_flags, preferred_zone,
2629 classzone_idx, migratetype,
2630 &did_some_progress);
2635 * If we failed to make any progress reclaiming, then we are
2636 * running out of options and have to consider going OOM
2638 if (!did_some_progress) {
2639 if (oom_gfp_allowed(gfp_mask)) {
2640 if (oom_killer_disabled)
2642 /* Coredumps can quickly deplete all memory reserves */
2643 if ((current->flags & PF_DUMPCORE) &&
2644 !(gfp_mask & __GFP_NOFAIL))
2646 page = __alloc_pages_may_oom(gfp_mask, order,
2647 zonelist, high_zoneidx,
2648 nodemask, preferred_zone,
2649 classzone_idx, migratetype);
2653 if (!(gfp_mask & __GFP_NOFAIL)) {
2655 * The oom killer is not called for high-order
2656 * allocations that may fail, so if no progress
2657 * is being made, there are no other options and
2658 * retrying is unlikely to help.
2660 if (order > PAGE_ALLOC_COSTLY_ORDER)
2663 * The oom killer is not called for lowmem
2664 * allocations to prevent needlessly killing
2667 if (high_zoneidx < ZONE_NORMAL)
2675 /* Check if we should retry the allocation */
2676 pages_reclaimed += did_some_progress;
2677 if (should_alloc_retry(gfp_mask, order, did_some_progress,
2679 /* Wait for some write requests to complete then retry */
2680 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2684 * High-order allocations do not necessarily loop after
2685 * direct reclaim and reclaim/compaction depends on compaction
2686 * being called after reclaim so call directly if necessary
2688 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
2689 high_zoneidx, nodemask, alloc_flags,
2691 classzone_idx, migratetype,
2692 migration_mode, &contended_compaction,
2693 &deferred_compaction,
2694 &did_some_progress);
2700 warn_alloc_failed(gfp_mask, order, NULL);
2703 if (kmemcheck_enabled)
2704 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2710 * This is the 'heart' of the zoned buddy allocator.
2713 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2714 struct zonelist *zonelist, nodemask_t *nodemask)
2716 enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2717 struct zone *preferred_zone;
2718 struct zoneref *preferred_zoneref;
2719 struct page *page = NULL;
2720 int migratetype = allocflags_to_migratetype(gfp_mask);
2721 unsigned int cpuset_mems_cookie;
2722 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
2725 gfp_mask &= gfp_allowed_mask;
2727 lockdep_trace_alloc(gfp_mask);
2729 might_sleep_if(gfp_mask & __GFP_WAIT);
2731 if (should_fail_alloc_page(gfp_mask, order))
2735 * Check the zones suitable for the gfp_mask contain at least one
2736 * valid zone. It's possible to have an empty zonelist as a result
2737 * of GFP_THISNODE and a memoryless node
2739 if (unlikely(!zonelist->_zonerefs->zone))
2743 cpuset_mems_cookie = read_mems_allowed_begin();
2745 /* The preferred zone is used for statistics later */
2746 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
2747 nodemask ? : &cpuset_current_mems_allowed,
2749 if (!preferred_zone)
2751 classzone_idx = zonelist_zone_idx(preferred_zoneref);
2754 if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2755 alloc_flags |= ALLOC_CMA;
2758 /* First allocation attempt */
2759 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2760 zonelist, high_zoneidx, alloc_flags,
2761 preferred_zone, classzone_idx, migratetype);
2762 if (unlikely(!page)) {
2764 * The first pass makes sure allocations are spread
2765 * fairly within the local node. However, the local
2766 * node might have free pages left after the fairness
2767 * batches are exhausted, and remote zones haven't
2768 * even been considered yet. Try once more without
2769 * fairness, and include remote zones now, before
2770 * entering the slowpath and waking kswapd: prefer
2771 * spilling to a remote zone over swapping locally.
2773 if (alloc_flags & ALLOC_FAIR) {
2774 reset_alloc_batches(zonelist, high_zoneidx,
2776 alloc_flags &= ~ALLOC_FAIR;
2780 * Runtime PM, block IO and its error handling path
2781 * can deadlock because I/O on the device might not
2784 gfp_mask = memalloc_noio_flags(gfp_mask);
2785 page = __alloc_pages_slowpath(gfp_mask, order,
2786 zonelist, high_zoneidx, nodemask,
2787 preferred_zone, classzone_idx, migratetype);
2790 trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2794 * When updating a task's mems_allowed, it is possible to race with
2795 * parallel threads in such a way that an allocation can fail while
2796 * the mask is being updated. If a page allocation is about to fail,
2797 * check if the cpuset changed during allocation and if so, retry.
2799 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2804 EXPORT_SYMBOL(__alloc_pages_nodemask);
2807 * Common helper functions.
2809 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2814 * __get_free_pages() returns a 32-bit address, which cannot represent
2817 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2819 page = alloc_pages(gfp_mask, order);
2822 return (unsigned long) page_address(page);
2824 EXPORT_SYMBOL(__get_free_pages);
2826 unsigned long get_zeroed_page(gfp_t gfp_mask)
2828 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2830 EXPORT_SYMBOL(get_zeroed_page);
2832 void __free_pages(struct page *page, unsigned int order)
2834 if (put_page_testzero(page)) {
2836 free_hot_cold_page(page, false);
2838 __free_pages_ok(page, order);
2842 EXPORT_SYMBOL(__free_pages);
2844 void free_pages(unsigned long addr, unsigned int order)
2847 VM_BUG_ON(!virt_addr_valid((void *)addr));
2848 __free_pages(virt_to_page((void *)addr), order);
2852 EXPORT_SYMBOL(free_pages);
2855 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
2856 * of the current memory cgroup.
2858 * It should be used when the caller would like to use kmalloc, but since the
2859 * allocation is large, it has to fall back to the page allocator.
2861 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
2864 struct mem_cgroup *memcg = NULL;
2866 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2868 page = alloc_pages(gfp_mask, order);
2869 memcg_kmem_commit_charge(page, memcg, order);
2873 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
2876 struct mem_cgroup *memcg = NULL;
2878 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
2880 page = alloc_pages_node(nid, gfp_mask, order);
2881 memcg_kmem_commit_charge(page, memcg, order);
2886 * __free_kmem_pages and free_kmem_pages will free pages allocated with
2889 void __free_kmem_pages(struct page *page, unsigned int order)
2891 memcg_kmem_uncharge_pages(page, order);
2892 __free_pages(page, order);
2895 void free_kmem_pages(unsigned long addr, unsigned int order)
2898 VM_BUG_ON(!virt_addr_valid((void *)addr));
2899 __free_kmem_pages(virt_to_page((void *)addr), order);
2903 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2906 unsigned long alloc_end = addr + (PAGE_SIZE << order);
2907 unsigned long used = addr + PAGE_ALIGN(size);
2909 split_page(virt_to_page((void *)addr), order);
2910 while (used < alloc_end) {
2915 return (void *)addr;
2919 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2920 * @size: the number of bytes to allocate
2921 * @gfp_mask: GFP flags for the allocation
2923 * This function is similar to alloc_pages(), except that it allocates the
2924 * minimum number of pages to satisfy the request. alloc_pages() can only
2925 * allocate memory in power-of-two pages.
2927 * This function is also limited by MAX_ORDER.
2929 * Memory allocated by this function must be released by free_pages_exact().
2931 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2933 unsigned int order = get_order(size);
2936 addr = __get_free_pages(gfp_mask, order);
2937 return make_alloc_exact(addr, order, size);
2939 EXPORT_SYMBOL(alloc_pages_exact);
2942 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2944 * @nid: the preferred node ID where memory should be allocated
2945 * @size: the number of bytes to allocate
2946 * @gfp_mask: GFP flags for the allocation
2948 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2950 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2953 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2955 unsigned order = get_order(size);
2956 struct page *p = alloc_pages_node(nid, gfp_mask, order);
2959 return make_alloc_exact((unsigned long)page_address(p), order, size);
2961 EXPORT_SYMBOL(alloc_pages_exact_nid);
2964 * free_pages_exact - release memory allocated via alloc_pages_exact()
2965 * @virt: the value returned by alloc_pages_exact.
2966 * @size: size of allocation, same value as passed to alloc_pages_exact().
2968 * Release the memory allocated by a previous call to alloc_pages_exact.
2970 void free_pages_exact(void *virt, size_t size)
2972 unsigned long addr = (unsigned long)virt;
2973 unsigned long end = addr + PAGE_ALIGN(size);
2975 while (addr < end) {
2980 EXPORT_SYMBOL(free_pages_exact);
2983 * nr_free_zone_pages - count number of pages beyond high watermark
2984 * @offset: The zone index of the highest zone
2986 * nr_free_zone_pages() counts the number of counts pages which are beyond the
2987 * high watermark within all zones at or below a given zone index. For each
2988 * zone, the number of pages is calculated as:
2989 * managed_pages - high_pages
2991 static unsigned long nr_free_zone_pages(int offset)
2996 /* Just pick one node, since fallback list is circular */
2997 unsigned long sum = 0;
2999 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3001 for_each_zone_zonelist(zone, z, zonelist, offset) {
3002 unsigned long size = zone->managed_pages;
3003 unsigned long high = high_wmark_pages(zone);
3012 * nr_free_buffer_pages - count number of pages beyond high watermark
3014 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3015 * watermark within ZONE_DMA and ZONE_NORMAL.
3017 unsigned long nr_free_buffer_pages(void)
3019 return nr_free_zone_pages(gfp_zone(GFP_USER));
3021 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3024 * nr_free_pagecache_pages - count number of pages beyond high watermark
3026 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3027 * high watermark within all zones.
3029 unsigned long nr_free_pagecache_pages(void)
3031 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3034 static inline void show_node(struct zone *zone)
3036 if (IS_ENABLED(CONFIG_NUMA))
3037 printk("Node %d ", zone_to_nid(zone));
3040 void si_meminfo(struct sysinfo *val)
3042 val->totalram = totalram_pages;
3044 val->freeram = global_page_state(NR_FREE_PAGES);
3045 val->bufferram = nr_blockdev_pages();
3046 val->totalhigh = totalhigh_pages;
3047 val->freehigh = nr_free_highpages();
3048 val->mem_unit = PAGE_SIZE;
3051 EXPORT_SYMBOL(si_meminfo);
3054 void si_meminfo_node(struct sysinfo *val, int nid)
3056 int zone_type; /* needs to be signed */
3057 unsigned long managed_pages = 0;
3058 pg_data_t *pgdat = NODE_DATA(nid);
3060 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3061 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3062 val->totalram = managed_pages;
3063 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3064 #ifdef CONFIG_HIGHMEM
3065 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3066 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3072 val->mem_unit = PAGE_SIZE;
3077 * Determine whether the node should be displayed or not, depending on whether
3078 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3080 bool skip_free_areas_node(unsigned int flags, int nid)
3083 unsigned int cpuset_mems_cookie;
3085 if (!(flags & SHOW_MEM_FILTER_NODES))
3089 cpuset_mems_cookie = read_mems_allowed_begin();
3090 ret = !node_isset(nid, cpuset_current_mems_allowed);
3091 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3096 #define K(x) ((x) << (PAGE_SHIFT-10))
3098 static void show_migration_types(unsigned char type)
3100 static const char types[MIGRATE_TYPES] = {
3101 [MIGRATE_UNMOVABLE] = 'U',
3102 [MIGRATE_RECLAIMABLE] = 'E',
3103 [MIGRATE_MOVABLE] = 'M',
3104 [MIGRATE_RESERVE] = 'R',
3106 [MIGRATE_CMA] = 'C',
3108 #ifdef CONFIG_MEMORY_ISOLATION
3109 [MIGRATE_ISOLATE] = 'I',
3112 char tmp[MIGRATE_TYPES + 1];
3116 for (i = 0; i < MIGRATE_TYPES; i++) {
3117 if (type & (1 << i))
3122 printk("(%s) ", tmp);
3126 * Show free area list (used inside shift_scroll-lock stuff)
3127 * We also calculate the percentage fragmentation. We do this by counting the
3128 * memory on each free list with the exception of the first item on the list.
3129 * Suppresses nodes that are not allowed by current's cpuset if
3130 * SHOW_MEM_FILTER_NODES is passed.
3132 void show_free_areas(unsigned int filter)
3137 for_each_populated_zone(zone) {
3138 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3141 printk("%s per-cpu:\n", zone->name);
3143 for_each_online_cpu(cpu) {
3144 struct per_cpu_pageset *pageset;
3146 pageset = per_cpu_ptr(zone->pageset, cpu);
3148 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
3149 cpu, pageset->pcp.high,
3150 pageset->pcp.batch, pageset->pcp.count);
3154 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3155 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3157 " dirty:%lu writeback:%lu unstable:%lu\n"
3158 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3159 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3161 global_page_state(NR_ACTIVE_ANON),
3162 global_page_state(NR_INACTIVE_ANON),
3163 global_page_state(NR_ISOLATED_ANON),
3164 global_page_state(NR_ACTIVE_FILE),
3165 global_page_state(NR_INACTIVE_FILE),
3166 global_page_state(NR_ISOLATED_FILE),
3167 global_page_state(NR_UNEVICTABLE),
3168 global_page_state(NR_FILE_DIRTY),
3169 global_page_state(NR_WRITEBACK),
3170 global_page_state(NR_UNSTABLE_NFS),
3171 global_page_state(NR_FREE_PAGES),
3172 global_page_state(NR_SLAB_RECLAIMABLE),
3173 global_page_state(NR_SLAB_UNRECLAIMABLE),
3174 global_page_state(NR_FILE_MAPPED),
3175 global_page_state(NR_SHMEM),
3176 global_page_state(NR_PAGETABLE),
3177 global_page_state(NR_BOUNCE),
3178 global_page_state(NR_FREE_CMA_PAGES));
3180 for_each_populated_zone(zone) {
3183 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3191 " active_anon:%lukB"
3192 " inactive_anon:%lukB"
3193 " active_file:%lukB"
3194 " inactive_file:%lukB"
3195 " unevictable:%lukB"
3196 " isolated(anon):%lukB"
3197 " isolated(file):%lukB"
3205 " slab_reclaimable:%lukB"
3206 " slab_unreclaimable:%lukB"
3207 " kernel_stack:%lukB"
3212 " writeback_tmp:%lukB"
3213 " pages_scanned:%lu"
3214 " all_unreclaimable? %s"
3217 K(zone_page_state(zone, NR_FREE_PAGES)),
3218 K(min_wmark_pages(zone)),
3219 K(low_wmark_pages(zone)),
3220 K(high_wmark_pages(zone)),
3221 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3222 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3223 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3224 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3225 K(zone_page_state(zone, NR_UNEVICTABLE)),
3226 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3227 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3228 K(zone->present_pages),
3229 K(zone->managed_pages),
3230 K(zone_page_state(zone, NR_MLOCK)),
3231 K(zone_page_state(zone, NR_FILE_DIRTY)),
3232 K(zone_page_state(zone, NR_WRITEBACK)),
3233 K(zone_page_state(zone, NR_FILE_MAPPED)),
3234 K(zone_page_state(zone, NR_SHMEM)),
3235 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3236 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3237 zone_page_state(zone, NR_KERNEL_STACK) *
3239 K(zone_page_state(zone, NR_PAGETABLE)),
3240 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3241 K(zone_page_state(zone, NR_BOUNCE)),
3242 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3243 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3244 zone->pages_scanned,
3245 (!zone_reclaimable(zone) ? "yes" : "no")
3247 printk("lowmem_reserve[]:");
3248 for (i = 0; i < MAX_NR_ZONES; i++)
3249 printk(" %lu", zone->lowmem_reserve[i]);
3253 for_each_populated_zone(zone) {
3254 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3255 unsigned char types[MAX_ORDER];
3257 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3260 printk("%s: ", zone->name);
3262 spin_lock_irqsave(&zone->lock, flags);
3263 for (order = 0; order < MAX_ORDER; order++) {
3264 struct free_area *area = &zone->free_area[order];
3267 nr[order] = area->nr_free;
3268 total += nr[order] << order;
3271 for (type = 0; type < MIGRATE_TYPES; type++) {
3272 if (!list_empty(&area->free_list[type]))
3273 types[order] |= 1 << type;
3276 spin_unlock_irqrestore(&zone->lock, flags);
3277 for (order = 0; order < MAX_ORDER; order++) {
3278 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3280 show_migration_types(types[order]);
3282 printk("= %lukB\n", K(total));
3285 hugetlb_show_meminfo();
3287 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3289 show_swap_cache_info();
3292 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3294 zoneref->zone = zone;
3295 zoneref->zone_idx = zone_idx(zone);
3299 * Builds allocation fallback zone lists.
3301 * Add all populated zones of a node to the zonelist.
3303 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3307 enum zone_type zone_type = MAX_NR_ZONES;
3311 zone = pgdat->node_zones + zone_type;
3312 if (populated_zone(zone)) {
3313 zoneref_set_zone(zone,
3314 &zonelist->_zonerefs[nr_zones++]);
3315 check_highest_zone(zone_type);
3317 } while (zone_type);
3325 * 0 = automatic detection of better ordering.
3326 * 1 = order by ([node] distance, -zonetype)
3327 * 2 = order by (-zonetype, [node] distance)
3329 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3330 * the same zonelist. So only NUMA can configure this param.
3332 #define ZONELIST_ORDER_DEFAULT 0
3333 #define ZONELIST_ORDER_NODE 1
3334 #define ZONELIST_ORDER_ZONE 2
3336 /* zonelist order in the kernel.
3337 * set_zonelist_order() will set this to NODE or ZONE.
3339 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3340 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3344 /* The value user specified ....changed by config */
3345 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3346 /* string for sysctl */
3347 #define NUMA_ZONELIST_ORDER_LEN 16
3348 char numa_zonelist_order[16] = "default";
3351 * interface for configure zonelist ordering.
3352 * command line option "numa_zonelist_order"
3353 * = "[dD]efault - default, automatic configuration.
3354 * = "[nN]ode - order by node locality, then by zone within node
3355 * = "[zZ]one - order by zone, then by locality within zone
3358 static int __parse_numa_zonelist_order(char *s)
3360 if (*s == 'd' || *s == 'D') {
3361 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3362 } else if (*s == 'n' || *s == 'N') {
3363 user_zonelist_order = ZONELIST_ORDER_NODE;
3364 } else if (*s == 'z' || *s == 'Z') {
3365 user_zonelist_order = ZONELIST_ORDER_ZONE;
3368 "Ignoring invalid numa_zonelist_order value: "
3375 static __init int setup_numa_zonelist_order(char *s)
3382 ret = __parse_numa_zonelist_order(s);
3384 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3388 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3391 * sysctl handler for numa_zonelist_order
3393 int numa_zonelist_order_handler(struct ctl_table *table, int write,
3394 void __user *buffer, size_t *length,
3397 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3399 static DEFINE_MUTEX(zl_order_mutex);
3401 mutex_lock(&zl_order_mutex);
3403 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3407 strcpy(saved_string, (char *)table->data);
3409 ret = proc_dostring(table, write, buffer, length, ppos);
3413 int oldval = user_zonelist_order;
3415 ret = __parse_numa_zonelist_order((char *)table->data);
3418 * bogus value. restore saved string
3420 strncpy((char *)table->data, saved_string,
3421 NUMA_ZONELIST_ORDER_LEN);
3422 user_zonelist_order = oldval;
3423 } else if (oldval != user_zonelist_order) {
3424 mutex_lock(&zonelists_mutex);
3425 build_all_zonelists(NULL, NULL);
3426 mutex_unlock(&zonelists_mutex);
3430 mutex_unlock(&zl_order_mutex);
3435 #define MAX_NODE_LOAD (nr_online_nodes)
3436 static int node_load[MAX_NUMNODES];
3439 * find_next_best_node - find the next node that should appear in a given node's fallback list
3440 * @node: node whose fallback list we're appending
3441 * @used_node_mask: nodemask_t of already used nodes
3443 * We use a number of factors to determine which is the next node that should
3444 * appear on a given node's fallback list. The node should not have appeared
3445 * already in @node's fallback list, and it should be the next closest node
3446 * according to the distance array (which contains arbitrary distance values
3447 * from each node to each node in the system), and should also prefer nodes
3448 * with no CPUs, since presumably they'll have very little allocation pressure
3449 * on them otherwise.
3450 * It returns -1 if no node is found.
3452 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3455 int min_val = INT_MAX;
3456 int best_node = NUMA_NO_NODE;
3457 const struct cpumask *tmp = cpumask_of_node(0);
3459 /* Use the local node if we haven't already */
3460 if (!node_isset(node, *used_node_mask)) {
3461 node_set(node, *used_node_mask);
3465 for_each_node_state(n, N_MEMORY) {
3467 /* Don't want a node to appear more than once */
3468 if (node_isset(n, *used_node_mask))
3471 /* Use the distance array to find the distance */
3472 val = node_distance(node, n);
3474 /* Penalize nodes under us ("prefer the next node") */
3477 /* Give preference to headless and unused nodes */
3478 tmp = cpumask_of_node(n);
3479 if (!cpumask_empty(tmp))
3480 val += PENALTY_FOR_NODE_WITH_CPUS;
3482 /* Slight preference for less loaded node */
3483 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3484 val += node_load[n];
3486 if (val < min_val) {
3493 node_set(best_node, *used_node_mask);
3500 * Build zonelists ordered by node and zones within node.
3501 * This results in maximum locality--normal zone overflows into local
3502 * DMA zone, if any--but risks exhausting DMA zone.
3504 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3507 struct zonelist *zonelist;
3509 zonelist = &pgdat->node_zonelists[0];
3510 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3512 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3513 zonelist->_zonerefs[j].zone = NULL;
3514 zonelist->_zonerefs[j].zone_idx = 0;
3518 * Build gfp_thisnode zonelists
3520 static void build_thisnode_zonelists(pg_data_t *pgdat)
3523 struct zonelist *zonelist;
3525 zonelist = &pgdat->node_zonelists[1];
3526 j = build_zonelists_node(pgdat, zonelist, 0);
3527 zonelist->_zonerefs[j].zone = NULL;
3528 zonelist->_zonerefs[j].zone_idx = 0;
3532 * Build zonelists ordered by zone and nodes within zones.
3533 * This results in conserving DMA zone[s] until all Normal memory is
3534 * exhausted, but results in overflowing to remote node while memory
3535 * may still exist in local DMA zone.
3537 static int node_order[MAX_NUMNODES];
3539 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3542 int zone_type; /* needs to be signed */
3544 struct zonelist *zonelist;
3546 zonelist = &pgdat->node_zonelists[0];
3548 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3549 for (j = 0; j < nr_nodes; j++) {
3550 node = node_order[j];
3551 z = &NODE_DATA(node)->node_zones[zone_type];
3552 if (populated_zone(z)) {
3554 &zonelist->_zonerefs[pos++]);
3555 check_highest_zone(zone_type);
3559 zonelist->_zonerefs[pos].zone = NULL;
3560 zonelist->_zonerefs[pos].zone_idx = 0;
3563 static int default_zonelist_order(void)
3566 unsigned long low_kmem_size, total_size;
3570 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3571 * If they are really small and used heavily, the system can fall
3572 * into OOM very easily.
3573 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3575 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3578 for_each_online_node(nid) {
3579 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3580 z = &NODE_DATA(nid)->node_zones[zone_type];
3581 if (populated_zone(z)) {
3582 if (zone_type < ZONE_NORMAL)
3583 low_kmem_size += z->managed_pages;
3584 total_size += z->managed_pages;
3585 } else if (zone_type == ZONE_NORMAL) {
3587 * If any node has only lowmem, then node order
3588 * is preferred to allow kernel allocations
3589 * locally; otherwise, they can easily infringe
3590 * on other nodes when there is an abundance of
3591 * lowmem available to allocate from.
3593 return ZONELIST_ORDER_NODE;
3597 if (!low_kmem_size || /* there are no DMA area. */
3598 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
3599 return ZONELIST_ORDER_NODE;
3601 * look into each node's config.
3602 * If there is a node whose DMA/DMA32 memory is very big area on
3603 * local memory, NODE_ORDER may be suitable.
3605 average_size = total_size /
3606 (nodes_weight(node_states[N_MEMORY]) + 1);
3607 for_each_online_node(nid) {
3610 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3611 z = &NODE_DATA(nid)->node_zones[zone_type];
3612 if (populated_zone(z)) {
3613 if (zone_type < ZONE_NORMAL)
3614 low_kmem_size += z->present_pages;
3615 total_size += z->present_pages;
3618 if (low_kmem_size &&
3619 total_size > average_size && /* ignore small node */
3620 low_kmem_size > total_size * 70/100)
3621 return ZONELIST_ORDER_NODE;
3623 return ZONELIST_ORDER_ZONE;
3626 static void set_zonelist_order(void)
3628 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3629 current_zonelist_order = default_zonelist_order();
3631 current_zonelist_order = user_zonelist_order;
3634 static void build_zonelists(pg_data_t *pgdat)
3638 nodemask_t used_mask;
3639 int local_node, prev_node;
3640 struct zonelist *zonelist;
3641 int order = current_zonelist_order;
3643 /* initialize zonelists */
3644 for (i = 0; i < MAX_ZONELISTS; i++) {
3645 zonelist = pgdat->node_zonelists + i;
3646 zonelist->_zonerefs[0].zone = NULL;
3647 zonelist->_zonerefs[0].zone_idx = 0;
3650 /* NUMA-aware ordering of nodes */
3651 local_node = pgdat->node_id;
3652 load = nr_online_nodes;
3653 prev_node = local_node;
3654 nodes_clear(used_mask);
3656 memset(node_order, 0, sizeof(node_order));
3659 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3661 * We don't want to pressure a particular node.
3662 * So adding penalty to the first node in same
3663 * distance group to make it round-robin.
3665 if (node_distance(local_node, node) !=
3666 node_distance(local_node, prev_node))
3667 node_load[node] = load;
3671 if (order == ZONELIST_ORDER_NODE)
3672 build_zonelists_in_node_order(pgdat, node);
3674 node_order[j++] = node; /* remember order */
3677 if (order == ZONELIST_ORDER_ZONE) {
3678 /* calculate node order -- i.e., DMA last! */
3679 build_zonelists_in_zone_order(pgdat, j);
3682 build_thisnode_zonelists(pgdat);
3685 /* Construct the zonelist performance cache - see further mmzone.h */
3686 static void build_zonelist_cache(pg_data_t *pgdat)
3688 struct zonelist *zonelist;
3689 struct zonelist_cache *zlc;
3692 zonelist = &pgdat->node_zonelists[0];
3693 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3694 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3695 for (z = zonelist->_zonerefs; z->zone; z++)
3696 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3699 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3701 * Return node id of node used for "local" allocations.
3702 * I.e., first node id of first zone in arg node's generic zonelist.
3703 * Used for initializing percpu 'numa_mem', which is used primarily
3704 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3706 int local_memory_node(int node)
3710 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3711 gfp_zone(GFP_KERNEL),
3718 #else /* CONFIG_NUMA */
3720 static void set_zonelist_order(void)
3722 current_zonelist_order = ZONELIST_ORDER_ZONE;
3725 static void build_zonelists(pg_data_t *pgdat)
3727 int node, local_node;
3729 struct zonelist *zonelist;
3731 local_node = pgdat->node_id;
3733 zonelist = &pgdat->node_zonelists[0];
3734 j = build_zonelists_node(pgdat, zonelist, 0);
3737 * Now we build the zonelist so that it contains the zones
3738 * of all the other nodes.
3739 * We don't want to pressure a particular node, so when
3740 * building the zones for node N, we make sure that the
3741 * zones coming right after the local ones are those from
3742 * node N+1 (modulo N)
3744 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3745 if (!node_online(node))
3747 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3749 for (node = 0; node < local_node; node++) {
3750 if (!node_online(node))
3752 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3755 zonelist->_zonerefs[j].zone = NULL;
3756 zonelist->_zonerefs[j].zone_idx = 0;
3759 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3760 static void build_zonelist_cache(pg_data_t *pgdat)
3762 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3765 #endif /* CONFIG_NUMA */
3768 * Boot pageset table. One per cpu which is going to be used for all
3769 * zones and all nodes. The parameters will be set in such a way
3770 * that an item put on a list will immediately be handed over to
3771 * the buddy list. This is safe since pageset manipulation is done
3772 * with interrupts disabled.
3774 * The boot_pagesets must be kept even after bootup is complete for
3775 * unused processors and/or zones. They do play a role for bootstrapping
3776 * hotplugged processors.
3778 * zoneinfo_show() and maybe other functions do
3779 * not check if the processor is online before following the pageset pointer.
3780 * Other parts of the kernel may not check if the zone is available.
3782 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3783 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3784 static void setup_zone_pageset(struct zone *zone);
3787 * Global mutex to protect against size modification of zonelists
3788 * as well as to serialize pageset setup for the new populated zone.
3790 DEFINE_MUTEX(zonelists_mutex);
3792 /* return values int ....just for stop_machine() */
3793 static int __build_all_zonelists(void *data)
3797 pg_data_t *self = data;
3800 memset(node_load, 0, sizeof(node_load));
3803 if (self && !node_online(self->node_id)) {
3804 build_zonelists(self);
3805 build_zonelist_cache(self);
3808 for_each_online_node(nid) {
3809 pg_data_t *pgdat = NODE_DATA(nid);
3811 build_zonelists(pgdat);
3812 build_zonelist_cache(pgdat);
3816 * Initialize the boot_pagesets that are going to be used
3817 * for bootstrapping processors. The real pagesets for
3818 * each zone will be allocated later when the per cpu
3819 * allocator is available.
3821 * boot_pagesets are used also for bootstrapping offline
3822 * cpus if the system is already booted because the pagesets
3823 * are needed to initialize allocators on a specific cpu too.
3824 * F.e. the percpu allocator needs the page allocator which
3825 * needs the percpu allocator in order to allocate its pagesets
3826 * (a chicken-egg dilemma).
3828 for_each_possible_cpu(cpu) {
3829 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3831 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3833 * We now know the "local memory node" for each node--
3834 * i.e., the node of the first zone in the generic zonelist.
3835 * Set up numa_mem percpu variable for on-line cpus. During
3836 * boot, only the boot cpu should be on-line; we'll init the
3837 * secondary cpus' numa_mem as they come on-line. During
3838 * node/memory hotplug, we'll fixup all on-line cpus.
3840 if (cpu_online(cpu))
3841 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3849 * Called with zonelists_mutex held always
3850 * unless system_state == SYSTEM_BOOTING.
3852 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3854 set_zonelist_order();
3856 if (system_state == SYSTEM_BOOTING) {
3857 __build_all_zonelists(NULL);
3858 mminit_verify_zonelist();
3859 cpuset_init_current_mems_allowed();
3861 #ifdef CONFIG_MEMORY_HOTPLUG
3863 setup_zone_pageset(zone);
3865 /* we have to stop all cpus to guarantee there is no user
3867 stop_machine(__build_all_zonelists, pgdat, NULL);
3868 /* cpuset refresh routine should be here */
3870 vm_total_pages = nr_free_pagecache_pages();
3872 * Disable grouping by mobility if the number of pages in the
3873 * system is too low to allow the mechanism to work. It would be
3874 * more accurate, but expensive to check per-zone. This check is
3875 * made on memory-hotadd so a system can start with mobility
3876 * disabled and enable it later
3878 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3879 page_group_by_mobility_disabled = 1;
3881 page_group_by_mobility_disabled = 0;
3883 printk("Built %i zonelists in %s order, mobility grouping %s. "
3884 "Total pages: %ld\n",
3886 zonelist_order_name[current_zonelist_order],
3887 page_group_by_mobility_disabled ? "off" : "on",
3890 printk("Policy zone: %s\n", zone_names[policy_zone]);
3895 * Helper functions to size the waitqueue hash table.
3896 * Essentially these want to choose hash table sizes sufficiently
3897 * large so that collisions trying to wait on pages are rare.
3898 * But in fact, the number of active page waitqueues on typical
3899 * systems is ridiculously low, less than 200. So this is even
3900 * conservative, even though it seems large.
3902 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3903 * waitqueues, i.e. the size of the waitq table given the number of pages.
3905 #define PAGES_PER_WAITQUEUE 256
3907 #ifndef CONFIG_MEMORY_HOTPLUG
3908 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3910 unsigned long size = 1;
3912 pages /= PAGES_PER_WAITQUEUE;
3914 while (size < pages)
3918 * Once we have dozens or even hundreds of threads sleeping
3919 * on IO we've got bigger problems than wait queue collision.
3920 * Limit the size of the wait table to a reasonable size.
3922 size = min(size, 4096UL);
3924 return max(size, 4UL);
3928 * A zone's size might be changed by hot-add, so it is not possible to determine
3929 * a suitable size for its wait_table. So we use the maximum size now.
3931 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3933 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3934 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3935 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3937 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3938 * or more by the traditional way. (See above). It equals:
3940 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3941 * ia64(16K page size) : = ( 8G + 4M)byte.
3942 * powerpc (64K page size) : = (32G +16M)byte.
3944 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3951 * This is an integer logarithm so that shifts can be used later
3952 * to extract the more random high bits from the multiplicative
3953 * hash function before the remainder is taken.
3955 static inline unsigned long wait_table_bits(unsigned long size)
3961 * Check if a pageblock contains reserved pages
3963 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3967 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3968 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3975 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3976 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3977 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3978 * higher will lead to a bigger reserve which will get freed as contiguous
3979 * blocks as reclaim kicks in
3981 static void setup_zone_migrate_reserve(struct zone *zone)
3983 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3985 unsigned long block_migratetype;
3990 * Get the start pfn, end pfn and the number of blocks to reserve
3991 * We have to be careful to be aligned to pageblock_nr_pages to
3992 * make sure that we always check pfn_valid for the first page in
3995 start_pfn = zone->zone_start_pfn;
3996 end_pfn = zone_end_pfn(zone);
3997 start_pfn = roundup(start_pfn, pageblock_nr_pages);
3998 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
4002 * Reserve blocks are generally in place to help high-order atomic
4003 * allocations that are short-lived. A min_free_kbytes value that
4004 * would result in more than 2 reserve blocks for atomic allocations
4005 * is assumed to be in place to help anti-fragmentation for the
4006 * future allocation of hugepages at runtime.
4008 reserve = min(2, reserve);
4009 old_reserve = zone->nr_migrate_reserve_block;
4011 /* When memory hot-add, we almost always need to do nothing */
4012 if (reserve == old_reserve)
4014 zone->nr_migrate_reserve_block = reserve;
4016 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
4017 if (!pfn_valid(pfn))
4019 page = pfn_to_page(pfn);
4021 /* Watch out for overlapping nodes */
4022 if (page_to_nid(page) != zone_to_nid(zone))
4025 block_migratetype = get_pageblock_migratetype(page);
4027 /* Only test what is necessary when the reserves are not met */
4030 * Blocks with reserved pages will never free, skip
4033 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
4034 if (pageblock_is_reserved(pfn, block_end_pfn))
4037 /* If this block is reserved, account for it */
4038 if (block_migratetype == MIGRATE_RESERVE) {
4043 /* Suitable for reserving if this block is movable */
4044 if (block_migratetype == MIGRATE_MOVABLE) {
4045 set_pageblock_migratetype(page,
4047 move_freepages_block(zone, page,
4052 } else if (!old_reserve) {
4054 * At boot time we don't need to scan the whole zone
4055 * for turning off MIGRATE_RESERVE.
4061 * If the reserve is met and this is a previous reserved block,
4064 if (block_migratetype == MIGRATE_RESERVE) {
4065 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4066 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4072 * Initially all pages are reserved - free ones are freed
4073 * up by free_all_bootmem() once the early boot process is
4074 * done. Non-atomic initialization, single-pass.
4076 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4077 unsigned long start_pfn, enum memmap_context context)
4080 unsigned long end_pfn = start_pfn + size;
4084 if (highest_memmap_pfn < end_pfn - 1)
4085 highest_memmap_pfn = end_pfn - 1;
4087 z = &NODE_DATA(nid)->node_zones[zone];
4088 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4090 * There can be holes in boot-time mem_map[]s
4091 * handed to this function. They do not
4092 * exist on hotplugged memory.
4094 if (context == MEMMAP_EARLY) {
4095 if (!early_pfn_valid(pfn))
4097 if (!early_pfn_in_nid(pfn, nid))
4100 page = pfn_to_page(pfn);
4101 set_page_links(page, zone, nid, pfn);
4102 mminit_verify_page_links(page, zone, nid, pfn);
4103 init_page_count(page);
4104 page_mapcount_reset(page);
4105 page_cpupid_reset_last(page);
4106 SetPageReserved(page);
4108 * Mark the block movable so that blocks are reserved for
4109 * movable at startup. This will force kernel allocations
4110 * to reserve their blocks rather than leaking throughout
4111 * the address space during boot when many long-lived
4112 * kernel allocations are made. Later some blocks near
4113 * the start are marked MIGRATE_RESERVE by
4114 * setup_zone_migrate_reserve()
4116 * bitmap is created for zone's valid pfn range. but memmap
4117 * can be created for invalid pages (for alignment)
4118 * check here not to call set_pageblock_migratetype() against
4121 if ((z->zone_start_pfn <= pfn)
4122 && (pfn < zone_end_pfn(z))
4123 && !(pfn & (pageblock_nr_pages - 1)))
4124 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4126 INIT_LIST_HEAD(&page->lru);
4127 #ifdef WANT_PAGE_VIRTUAL
4128 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4129 if (!is_highmem_idx(zone))
4130 set_page_address(page, __va(pfn << PAGE_SHIFT));
4135 static void __meminit zone_init_free_lists(struct zone *zone)
4137 unsigned int order, t;
4138 for_each_migratetype_order(order, t) {
4139 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4140 zone->free_area[order].nr_free = 0;
4144 #ifndef __HAVE_ARCH_MEMMAP_INIT
4145 #define memmap_init(size, nid, zone, start_pfn) \
4146 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4149 static int zone_batchsize(struct zone *zone)
4155 * The per-cpu-pages pools are set to around 1000th of the
4156 * size of the zone. But no more than 1/2 of a meg.
4158 * OK, so we don't know how big the cache is. So guess.
4160 batch = zone->managed_pages / 1024;
4161 if (batch * PAGE_SIZE > 512 * 1024)
4162 batch = (512 * 1024) / PAGE_SIZE;
4163 batch /= 4; /* We effectively *= 4 below */
4168 * Clamp the batch to a 2^n - 1 value. Having a power
4169 * of 2 value was found to be more likely to have
4170 * suboptimal cache aliasing properties in some cases.
4172 * For example if 2 tasks are alternately allocating
4173 * batches of pages, one task can end up with a lot
4174 * of pages of one half of the possible page colors
4175 * and the other with pages of the other colors.
4177 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4182 /* The deferral and batching of frees should be suppressed under NOMMU
4185 * The problem is that NOMMU needs to be able to allocate large chunks
4186 * of contiguous memory as there's no hardware page translation to
4187 * assemble apparent contiguous memory from discontiguous pages.
4189 * Queueing large contiguous runs of pages for batching, however,
4190 * causes the pages to actually be freed in smaller chunks. As there
4191 * can be a significant delay between the individual batches being
4192 * recycled, this leads to the once large chunks of space being
4193 * fragmented and becoming unavailable for high-order allocations.
4200 * pcp->high and pcp->batch values are related and dependent on one another:
4201 * ->batch must never be higher then ->high.
4202 * The following function updates them in a safe manner without read side
4205 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4206 * those fields changing asynchronously (acording the the above rule).
4208 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4209 * outside of boot time (or some other assurance that no concurrent updaters
4212 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4213 unsigned long batch)
4215 /* start with a fail safe value for batch */
4219 /* Update high, then batch, in order */
4226 /* a companion to pageset_set_high() */
4227 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4229 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4232 static void pageset_init(struct per_cpu_pageset *p)
4234 struct per_cpu_pages *pcp;
4237 memset(p, 0, sizeof(*p));
4241 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4242 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4245 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4248 pageset_set_batch(p, batch);
4252 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4253 * to the value high for the pageset p.
4255 static void pageset_set_high(struct per_cpu_pageset *p,
4258 unsigned long batch = max(1UL, high / 4);
4259 if ((high / 4) > (PAGE_SHIFT * 8))
4260 batch = PAGE_SHIFT * 8;
4262 pageset_update(&p->pcp, high, batch);
4265 static void pageset_set_high_and_batch(struct zone *zone,
4266 struct per_cpu_pageset *pcp)
4268 if (percpu_pagelist_fraction)
4269 pageset_set_high(pcp,
4270 (zone->managed_pages /
4271 percpu_pagelist_fraction));
4273 pageset_set_batch(pcp, zone_batchsize(zone));
4276 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4278 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4281 pageset_set_high_and_batch(zone, pcp);
4284 static void __meminit setup_zone_pageset(struct zone *zone)
4287 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4288 for_each_possible_cpu(cpu)
4289 zone_pageset_init(zone, cpu);
4293 * Allocate per cpu pagesets and initialize them.
4294 * Before this call only boot pagesets were available.
4296 void __init setup_per_cpu_pageset(void)
4300 for_each_populated_zone(zone)
4301 setup_zone_pageset(zone);
4304 static noinline __init_refok
4305 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4311 * The per-page waitqueue mechanism uses hashed waitqueues
4314 zone->wait_table_hash_nr_entries =
4315 wait_table_hash_nr_entries(zone_size_pages);
4316 zone->wait_table_bits =
4317 wait_table_bits(zone->wait_table_hash_nr_entries);
4318 alloc_size = zone->wait_table_hash_nr_entries
4319 * sizeof(wait_queue_head_t);
4321 if (!slab_is_available()) {
4322 zone->wait_table = (wait_queue_head_t *)
4323 memblock_virt_alloc_node_nopanic(
4324 alloc_size, zone->zone_pgdat->node_id);
4327 * This case means that a zone whose size was 0 gets new memory
4328 * via memory hot-add.
4329 * But it may be the case that a new node was hot-added. In
4330 * this case vmalloc() will not be able to use this new node's
4331 * memory - this wait_table must be initialized to use this new
4332 * node itself as well.
4333 * To use this new node's memory, further consideration will be
4336 zone->wait_table = vmalloc(alloc_size);
4338 if (!zone->wait_table)
4341 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4342 init_waitqueue_head(zone->wait_table + i);
4347 static __meminit void zone_pcp_init(struct zone *zone)
4350 * per cpu subsystem is not up at this point. The following code
4351 * relies on the ability of the linker to provide the
4352 * offset of a (static) per cpu variable into the per cpu area.
4354 zone->pageset = &boot_pageset;
4356 if (populated_zone(zone))
4357 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4358 zone->name, zone->present_pages,
4359 zone_batchsize(zone));
4362 int __meminit init_currently_empty_zone(struct zone *zone,
4363 unsigned long zone_start_pfn,
4365 enum memmap_context context)
4367 struct pglist_data *pgdat = zone->zone_pgdat;
4369 ret = zone_wait_table_init(zone, size);
4372 pgdat->nr_zones = zone_idx(zone) + 1;
4374 zone->zone_start_pfn = zone_start_pfn;
4376 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4377 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4379 (unsigned long)zone_idx(zone),
4380 zone_start_pfn, (zone_start_pfn + size));
4382 zone_init_free_lists(zone);
4387 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4388 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4390 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4392 int __meminit __early_pfn_to_nid(unsigned long pfn)
4394 unsigned long start_pfn, end_pfn;
4397 * NOTE: The following SMP-unsafe globals are only used early in boot
4398 * when the kernel is running single-threaded.
4400 static unsigned long __meminitdata last_start_pfn, last_end_pfn;
4401 static int __meminitdata last_nid;
4403 if (last_start_pfn <= pfn && pfn < last_end_pfn)
4406 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4408 last_start_pfn = start_pfn;
4409 last_end_pfn = end_pfn;
4415 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4417 int __meminit early_pfn_to_nid(unsigned long pfn)
4421 nid = __early_pfn_to_nid(pfn);
4424 /* just returns 0 */
4428 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4429 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4433 nid = __early_pfn_to_nid(pfn);
4434 if (nid >= 0 && nid != node)
4441 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4442 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4443 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4445 * If an architecture guarantees that all ranges registered contain no holes
4446 * and may be freed, this this function may be used instead of calling
4447 * memblock_free_early_nid() manually.
4449 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4451 unsigned long start_pfn, end_pfn;
4454 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4455 start_pfn = min(start_pfn, max_low_pfn);
4456 end_pfn = min(end_pfn, max_low_pfn);
4458 if (start_pfn < end_pfn)
4459 memblock_free_early_nid(PFN_PHYS(start_pfn),
4460 (end_pfn - start_pfn) << PAGE_SHIFT,
4466 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4467 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4469 * If an architecture guarantees that all ranges registered contain no holes and may
4470 * be freed, this function may be used instead of calling memory_present() manually.
4472 void __init sparse_memory_present_with_active_regions(int nid)
4474 unsigned long start_pfn, end_pfn;
4477 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4478 memory_present(this_nid, start_pfn, end_pfn);
4482 * get_pfn_range_for_nid - Return the start and end page frames for a node
4483 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4484 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4485 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4487 * It returns the start and end page frame of a node based on information
4488 * provided by memblock_set_node(). If called for a node
4489 * with no available memory, a warning is printed and the start and end
4492 void __meminit get_pfn_range_for_nid(unsigned int nid,
4493 unsigned long *start_pfn, unsigned long *end_pfn)
4495 unsigned long this_start_pfn, this_end_pfn;
4501 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
4502 *start_pfn = min(*start_pfn, this_start_pfn);
4503 *end_pfn = max(*end_pfn, this_end_pfn);
4506 if (*start_pfn == -1UL)
4511 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4512 * assumption is made that zones within a node are ordered in monotonic
4513 * increasing memory addresses so that the "highest" populated zone is used
4515 static void __init find_usable_zone_for_movable(void)
4518 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4519 if (zone_index == ZONE_MOVABLE)
4522 if (arch_zone_highest_possible_pfn[zone_index] >
4523 arch_zone_lowest_possible_pfn[zone_index])
4527 VM_BUG_ON(zone_index == -1);
4528 movable_zone = zone_index;
4532 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4533 * because it is sized independent of architecture. Unlike the other zones,
4534 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4535 * in each node depending on the size of each node and how evenly kernelcore
4536 * is distributed. This helper function adjusts the zone ranges
4537 * provided by the architecture for a given node by using the end of the
4538 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4539 * zones within a node are in order of monotonic increases memory addresses
4541 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4542 unsigned long zone_type,
4543 unsigned long node_start_pfn,
4544 unsigned long node_end_pfn,
4545 unsigned long *zone_start_pfn,
4546 unsigned long *zone_end_pfn)
4548 /* Only adjust if ZONE_MOVABLE is on this node */
4549 if (zone_movable_pfn[nid]) {
4550 /* Size ZONE_MOVABLE */
4551 if (zone_type == ZONE_MOVABLE) {
4552 *zone_start_pfn = zone_movable_pfn[nid];
4553 *zone_end_pfn = min(node_end_pfn,
4554 arch_zone_highest_possible_pfn[movable_zone]);
4556 /* Adjust for ZONE_MOVABLE starting within this range */
4557 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4558 *zone_end_pfn > zone_movable_pfn[nid]) {
4559 *zone_end_pfn = zone_movable_pfn[nid];
4561 /* Check if this whole range is within ZONE_MOVABLE */
4562 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4563 *zone_start_pfn = *zone_end_pfn;
4568 * Return the number of pages a zone spans in a node, including holes
4569 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4571 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4572 unsigned long zone_type,
4573 unsigned long node_start_pfn,
4574 unsigned long node_end_pfn,
4575 unsigned long *ignored)
4577 unsigned long zone_start_pfn, zone_end_pfn;
4579 /* Get the start and end of the zone */
4580 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4581 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4582 adjust_zone_range_for_zone_movable(nid, zone_type,
4583 node_start_pfn, node_end_pfn,
4584 &zone_start_pfn, &zone_end_pfn);
4586 /* Check that this node has pages within the zone's required range */
4587 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4590 /* Move the zone boundaries inside the node if necessary */
4591 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4592 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4594 /* Return the spanned pages */
4595 return zone_end_pfn - zone_start_pfn;
4599 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4600 * then all holes in the requested range will be accounted for.
4602 unsigned long __meminit __absent_pages_in_range(int nid,
4603 unsigned long range_start_pfn,
4604 unsigned long range_end_pfn)
4606 unsigned long nr_absent = range_end_pfn - range_start_pfn;
4607 unsigned long start_pfn, end_pfn;
4610 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4611 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4612 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4613 nr_absent -= end_pfn - start_pfn;
4619 * absent_pages_in_range - Return number of page frames in holes within a range
4620 * @start_pfn: The start PFN to start searching for holes
4621 * @end_pfn: The end PFN to stop searching for holes
4623 * It returns the number of pages frames in memory holes within a range.
4625 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4626 unsigned long end_pfn)
4628 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4631 /* Return the number of page frames in holes in a zone on a node */
4632 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4633 unsigned long zone_type,
4634 unsigned long node_start_pfn,
4635 unsigned long node_end_pfn,
4636 unsigned long *ignored)
4638 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4639 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4640 unsigned long zone_start_pfn, zone_end_pfn;
4642 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4643 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4645 adjust_zone_range_for_zone_movable(nid, zone_type,
4646 node_start_pfn, node_end_pfn,
4647 &zone_start_pfn, &zone_end_pfn);
4648 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4651 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4652 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4653 unsigned long zone_type,
4654 unsigned long node_start_pfn,
4655 unsigned long node_end_pfn,
4656 unsigned long *zones_size)
4658 return zones_size[zone_type];
4661 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4662 unsigned long zone_type,
4663 unsigned long node_start_pfn,
4664 unsigned long node_end_pfn,
4665 unsigned long *zholes_size)
4670 return zholes_size[zone_type];
4673 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4675 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4676 unsigned long node_start_pfn,
4677 unsigned long node_end_pfn,
4678 unsigned long *zones_size,
4679 unsigned long *zholes_size)
4681 unsigned long realtotalpages, totalpages = 0;
4684 for (i = 0; i < MAX_NR_ZONES; i++)
4685 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4689 pgdat->node_spanned_pages = totalpages;
4691 realtotalpages = totalpages;
4692 for (i = 0; i < MAX_NR_ZONES; i++)
4694 zone_absent_pages_in_node(pgdat->node_id, i,
4695 node_start_pfn, node_end_pfn,
4697 pgdat->node_present_pages = realtotalpages;
4698 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4702 #ifndef CONFIG_SPARSEMEM
4704 * Calculate the size of the zone->blockflags rounded to an unsigned long
4705 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4706 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4707 * round what is now in bits to nearest long in bits, then return it in
4710 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4712 unsigned long usemapsize;
4714 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4715 usemapsize = roundup(zonesize, pageblock_nr_pages);
4716 usemapsize = usemapsize >> pageblock_order;
4717 usemapsize *= NR_PAGEBLOCK_BITS;
4718 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4720 return usemapsize / 8;
4723 static void __init setup_usemap(struct pglist_data *pgdat,
4725 unsigned long zone_start_pfn,
4726 unsigned long zonesize)
4728 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4729 zone->pageblock_flags = NULL;
4731 zone->pageblock_flags =
4732 memblock_virt_alloc_node_nopanic(usemapsize,
4736 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4737 unsigned long zone_start_pfn, unsigned long zonesize) {}
4738 #endif /* CONFIG_SPARSEMEM */
4740 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4742 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4743 void __paginginit set_pageblock_order(void)
4747 /* Check that pageblock_nr_pages has not already been setup */
4748 if (pageblock_order)
4751 if (HPAGE_SHIFT > PAGE_SHIFT)
4752 order = HUGETLB_PAGE_ORDER;
4754 order = MAX_ORDER - 1;
4757 * Assume the largest contiguous order of interest is a huge page.
4758 * This value may be variable depending on boot parameters on IA64 and
4761 pageblock_order = order;
4763 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4766 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4767 * is unused as pageblock_order is set at compile-time. See
4768 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4771 void __paginginit set_pageblock_order(void)
4775 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4777 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
4778 unsigned long present_pages)
4780 unsigned long pages = spanned_pages;
4783 * Provide a more accurate estimation if there are holes within
4784 * the zone and SPARSEMEM is in use. If there are holes within the
4785 * zone, each populated memory region may cost us one or two extra
4786 * memmap pages due to alignment because memmap pages for each
4787 * populated regions may not naturally algined on page boundary.
4788 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4790 if (spanned_pages > present_pages + (present_pages >> 4) &&
4791 IS_ENABLED(CONFIG_SPARSEMEM))
4792 pages = present_pages;
4794 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
4798 * Set up the zone data structures:
4799 * - mark all pages reserved
4800 * - mark all memory queues empty
4801 * - clear the memory bitmaps
4803 * NOTE: pgdat should get zeroed by caller.
4805 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4806 unsigned long node_start_pfn, unsigned long node_end_pfn,
4807 unsigned long *zones_size, unsigned long *zholes_size)
4810 int nid = pgdat->node_id;
4811 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4814 pgdat_resize_init(pgdat);
4815 #ifdef CONFIG_NUMA_BALANCING
4816 spin_lock_init(&pgdat->numabalancing_migrate_lock);
4817 pgdat->numabalancing_migrate_nr_pages = 0;
4818 pgdat->numabalancing_migrate_next_window = jiffies;
4820 init_waitqueue_head(&pgdat->kswapd_wait);
4821 init_waitqueue_head(&pgdat->pfmemalloc_wait);
4822 pgdat_page_cgroup_init(pgdat);
4824 for (j = 0; j < MAX_NR_ZONES; j++) {
4825 struct zone *zone = pgdat->node_zones + j;
4826 unsigned long size, realsize, freesize, memmap_pages;
4828 size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
4829 node_end_pfn, zones_size);
4830 realsize = freesize = size - zone_absent_pages_in_node(nid, j,
4836 * Adjust freesize so that it accounts for how much memory
4837 * is used by this zone for memmap. This affects the watermark
4838 * and per-cpu initialisations
4840 memmap_pages = calc_memmap_size(size, realsize);
4841 if (freesize >= memmap_pages) {
4842 freesize -= memmap_pages;
4845 " %s zone: %lu pages used for memmap\n",
4846 zone_names[j], memmap_pages);
4849 " %s zone: %lu pages exceeds freesize %lu\n",
4850 zone_names[j], memmap_pages, freesize);
4852 /* Account for reserved pages */
4853 if (j == 0 && freesize > dma_reserve) {
4854 freesize -= dma_reserve;
4855 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4856 zone_names[0], dma_reserve);
4859 if (!is_highmem_idx(j))
4860 nr_kernel_pages += freesize;
4861 /* Charge for highmem memmap if there are enough kernel pages */
4862 else if (nr_kernel_pages > memmap_pages * 2)
4863 nr_kernel_pages -= memmap_pages;
4864 nr_all_pages += freesize;
4866 zone->spanned_pages = size;
4867 zone->present_pages = realsize;
4869 * Set an approximate value for lowmem here, it will be adjusted
4870 * when the bootmem allocator frees pages into the buddy system.
4871 * And all highmem pages will be managed by the buddy system.
4873 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
4876 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4878 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4880 zone->name = zone_names[j];
4881 spin_lock_init(&zone->lock);
4882 spin_lock_init(&zone->lru_lock);
4883 zone_seqlock_init(zone);
4884 zone->zone_pgdat = pgdat;
4885 zone_pcp_init(zone);
4887 /* For bootup, initialized properly in watermark setup */
4888 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
4890 lruvec_init(&zone->lruvec);
4894 set_pageblock_order();
4895 setup_usemap(pgdat, zone, zone_start_pfn, size);
4896 ret = init_currently_empty_zone(zone, zone_start_pfn,
4897 size, MEMMAP_EARLY);
4899 memmap_init(size, nid, j, zone_start_pfn);
4900 zone_start_pfn += size;
4904 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4906 /* Skip empty nodes */
4907 if (!pgdat->node_spanned_pages)
4910 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4911 /* ia64 gets its own node_mem_map, before this, without bootmem */
4912 if (!pgdat->node_mem_map) {
4913 unsigned long size, start, end;
4917 * The zone's endpoints aren't required to be MAX_ORDER
4918 * aligned but the node_mem_map endpoints must be in order
4919 * for the buddy allocator to function correctly.
4921 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4922 end = pgdat_end_pfn(pgdat);
4923 end = ALIGN(end, MAX_ORDER_NR_PAGES);
4924 size = (end - start) * sizeof(struct page);
4925 map = alloc_remap(pgdat->node_id, size);
4927 map = memblock_virt_alloc_node_nopanic(size,
4929 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4931 #ifndef CONFIG_NEED_MULTIPLE_NODES
4933 * With no DISCONTIG, the global mem_map is just set as node 0's
4935 if (pgdat == NODE_DATA(0)) {
4936 mem_map = NODE_DATA(0)->node_mem_map;
4937 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4938 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4939 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4940 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4943 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4946 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4947 unsigned long node_start_pfn, unsigned long *zholes_size)
4949 pg_data_t *pgdat = NODE_DATA(nid);
4950 unsigned long start_pfn = 0;
4951 unsigned long end_pfn = 0;
4953 /* pg_data_t should be reset to zero when it's allocated */
4954 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4956 pgdat->node_id = nid;
4957 pgdat->node_start_pfn = node_start_pfn;
4958 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4959 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
4961 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
4962 zones_size, zholes_size);
4964 alloc_node_mem_map(pgdat);
4965 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4966 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4967 nid, (unsigned long)pgdat,
4968 (unsigned long)pgdat->node_mem_map);
4971 free_area_init_core(pgdat, start_pfn, end_pfn,
4972 zones_size, zholes_size);
4975 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4977 #if MAX_NUMNODES > 1
4979 * Figure out the number of possible node ids.
4981 void __init setup_nr_node_ids(void)
4984 unsigned int highest = 0;
4986 for_each_node_mask(node, node_possible_map)
4988 nr_node_ids = highest + 1;
4993 * node_map_pfn_alignment - determine the maximum internode alignment
4995 * This function should be called after node map is populated and sorted.
4996 * It calculates the maximum power of two alignment which can distinguish
4999 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5000 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5001 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5002 * shifted, 1GiB is enough and this function will indicate so.
5004 * This is used to test whether pfn -> nid mapping of the chosen memory
5005 * model has fine enough granularity to avoid incorrect mapping for the
5006 * populated node map.
5008 * Returns the determined alignment in pfn's. 0 if there is no alignment
5009 * requirement (single node).
5011 unsigned long __init node_map_pfn_alignment(void)
5013 unsigned long accl_mask = 0, last_end = 0;
5014 unsigned long start, end, mask;
5018 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5019 if (!start || last_nid < 0 || last_nid == nid) {
5026 * Start with a mask granular enough to pin-point to the
5027 * start pfn and tick off bits one-by-one until it becomes
5028 * too coarse to separate the current node from the last.
5030 mask = ~((1 << __ffs(start)) - 1);
5031 while (mask && last_end <= (start & (mask << 1)))
5034 /* accumulate all internode masks */
5038 /* convert mask to number of pages */
5039 return ~accl_mask + 1;
5042 /* Find the lowest pfn for a node */
5043 static unsigned long __init find_min_pfn_for_node(int nid)
5045 unsigned long min_pfn = ULONG_MAX;
5046 unsigned long start_pfn;
5049 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5050 min_pfn = min(min_pfn, start_pfn);
5052 if (min_pfn == ULONG_MAX) {
5054 "Could not find start_pfn for node %d\n", nid);
5062 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5064 * It returns the minimum PFN based on information provided via
5065 * memblock_set_node().
5067 unsigned long __init find_min_pfn_with_active_regions(void)
5069 return find_min_pfn_for_node(MAX_NUMNODES);
5073 * early_calculate_totalpages()
5074 * Sum pages in active regions for movable zone.
5075 * Populate N_MEMORY for calculating usable_nodes.
5077 static unsigned long __init early_calculate_totalpages(void)
5079 unsigned long totalpages = 0;
5080 unsigned long start_pfn, end_pfn;
5083 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5084 unsigned long pages = end_pfn - start_pfn;
5086 totalpages += pages;
5088 node_set_state(nid, N_MEMORY);
5094 * Find the PFN the Movable zone begins in each node. Kernel memory
5095 * is spread evenly between nodes as long as the nodes have enough
5096 * memory. When they don't, some nodes will have more kernelcore than
5099 static void __init find_zone_movable_pfns_for_nodes(void)
5102 unsigned long usable_startpfn;
5103 unsigned long kernelcore_node, kernelcore_remaining;
5104 /* save the state before borrow the nodemask */
5105 nodemask_t saved_node_state = node_states[N_MEMORY];
5106 unsigned long totalpages = early_calculate_totalpages();
5107 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5108 struct memblock_region *r;
5110 /* Need to find movable_zone earlier when movable_node is specified. */
5111 find_usable_zone_for_movable();
5114 * If movable_node is specified, ignore kernelcore and movablecore
5117 if (movable_node_is_enabled()) {
5118 for_each_memblock(memory, r) {
5119 if (!memblock_is_hotpluggable(r))
5124 usable_startpfn = PFN_DOWN(r->base);
5125 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5126 min(usable_startpfn, zone_movable_pfn[nid]) :
5134 * If movablecore=nn[KMG] was specified, calculate what size of
5135 * kernelcore that corresponds so that memory usable for
5136 * any allocation type is evenly spread. If both kernelcore
5137 * and movablecore are specified, then the value of kernelcore
5138 * will be used for required_kernelcore if it's greater than
5139 * what movablecore would have allowed.
5141 if (required_movablecore) {
5142 unsigned long corepages;
5145 * Round-up so that ZONE_MOVABLE is at least as large as what
5146 * was requested by the user
5148 required_movablecore =
5149 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5150 corepages = totalpages - required_movablecore;
5152 required_kernelcore = max(required_kernelcore, corepages);
5155 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5156 if (!required_kernelcore)
5159 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5160 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5163 /* Spread kernelcore memory as evenly as possible throughout nodes */
5164 kernelcore_node = required_kernelcore / usable_nodes;
5165 for_each_node_state(nid, N_MEMORY) {
5166 unsigned long start_pfn, end_pfn;
5169 * Recalculate kernelcore_node if the division per node
5170 * now exceeds what is necessary to satisfy the requested
5171 * amount of memory for the kernel
5173 if (required_kernelcore < kernelcore_node)
5174 kernelcore_node = required_kernelcore / usable_nodes;
5177 * As the map is walked, we track how much memory is usable
5178 * by the kernel using kernelcore_remaining. When it is
5179 * 0, the rest of the node is usable by ZONE_MOVABLE
5181 kernelcore_remaining = kernelcore_node;
5183 /* Go through each range of PFNs within this node */
5184 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5185 unsigned long size_pages;
5187 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5188 if (start_pfn >= end_pfn)
5191 /* Account for what is only usable for kernelcore */
5192 if (start_pfn < usable_startpfn) {
5193 unsigned long kernel_pages;
5194 kernel_pages = min(end_pfn, usable_startpfn)
5197 kernelcore_remaining -= min(kernel_pages,
5198 kernelcore_remaining);
5199 required_kernelcore -= min(kernel_pages,
5200 required_kernelcore);
5202 /* Continue if range is now fully accounted */
5203 if (end_pfn <= usable_startpfn) {
5206 * Push zone_movable_pfn to the end so
5207 * that if we have to rebalance
5208 * kernelcore across nodes, we will
5209 * not double account here
5211 zone_movable_pfn[nid] = end_pfn;
5214 start_pfn = usable_startpfn;
5218 * The usable PFN range for ZONE_MOVABLE is from
5219 * start_pfn->end_pfn. Calculate size_pages as the
5220 * number of pages used as kernelcore
5222 size_pages = end_pfn - start_pfn;
5223 if (size_pages > kernelcore_remaining)
5224 size_pages = kernelcore_remaining;
5225 zone_movable_pfn[nid] = start_pfn + size_pages;
5228 * Some kernelcore has been met, update counts and
5229 * break if the kernelcore for this node has been
5232 required_kernelcore -= min(required_kernelcore,
5234 kernelcore_remaining -= size_pages;
5235 if (!kernelcore_remaining)
5241 * If there is still required_kernelcore, we do another pass with one
5242 * less node in the count. This will push zone_movable_pfn[nid] further
5243 * along on the nodes that still have memory until kernelcore is
5247 if (usable_nodes && required_kernelcore > usable_nodes)
5251 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5252 for (nid = 0; nid < MAX_NUMNODES; nid++)
5253 zone_movable_pfn[nid] =
5254 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5257 /* restore the node_state */
5258 node_states[N_MEMORY] = saved_node_state;
5261 /* Any regular or high memory on that node ? */
5262 static void check_for_memory(pg_data_t *pgdat, int nid)
5264 enum zone_type zone_type;
5266 if (N_MEMORY == N_NORMAL_MEMORY)
5269 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5270 struct zone *zone = &pgdat->node_zones[zone_type];
5271 if (populated_zone(zone)) {
5272 node_set_state(nid, N_HIGH_MEMORY);
5273 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5274 zone_type <= ZONE_NORMAL)
5275 node_set_state(nid, N_NORMAL_MEMORY);
5282 * free_area_init_nodes - Initialise all pg_data_t and zone data
5283 * @max_zone_pfn: an array of max PFNs for each zone
5285 * This will call free_area_init_node() for each active node in the system.
5286 * Using the page ranges provided by memblock_set_node(), the size of each
5287 * zone in each node and their holes is calculated. If the maximum PFN
5288 * between two adjacent zones match, it is assumed that the zone is empty.
5289 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5290 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5291 * starts where the previous one ended. For example, ZONE_DMA32 starts
5292 * at arch_max_dma_pfn.
5294 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5296 unsigned long start_pfn, end_pfn;
5299 /* Record where the zone boundaries are */
5300 memset(arch_zone_lowest_possible_pfn, 0,
5301 sizeof(arch_zone_lowest_possible_pfn));
5302 memset(arch_zone_highest_possible_pfn, 0,
5303 sizeof(arch_zone_highest_possible_pfn));
5304 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5305 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5306 for (i = 1; i < MAX_NR_ZONES; i++) {
5307 if (i == ZONE_MOVABLE)
5309 arch_zone_lowest_possible_pfn[i] =
5310 arch_zone_highest_possible_pfn[i-1];
5311 arch_zone_highest_possible_pfn[i] =
5312 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5314 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5315 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5317 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5318 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5319 find_zone_movable_pfns_for_nodes();
5321 /* Print out the zone ranges */
5322 printk("Zone ranges:\n");
5323 for (i = 0; i < MAX_NR_ZONES; i++) {
5324 if (i == ZONE_MOVABLE)
5326 printk(KERN_CONT " %-8s ", zone_names[i]);
5327 if (arch_zone_lowest_possible_pfn[i] ==
5328 arch_zone_highest_possible_pfn[i])
5329 printk(KERN_CONT "empty\n");
5331 printk(KERN_CONT "[mem %0#10lx-%0#10lx]\n",
5332 arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT,
5333 (arch_zone_highest_possible_pfn[i]
5334 << PAGE_SHIFT) - 1);
5337 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5338 printk("Movable zone start for each node\n");
5339 for (i = 0; i < MAX_NUMNODES; i++) {
5340 if (zone_movable_pfn[i])
5341 printk(" Node %d: %#010lx\n", i,
5342 zone_movable_pfn[i] << PAGE_SHIFT);
5345 /* Print out the early node map */
5346 printk("Early memory node ranges\n");
5347 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5348 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid,
5349 start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
5351 /* Initialise every node */
5352 mminit_verify_pageflags_layout();
5353 setup_nr_node_ids();
5354 for_each_online_node(nid) {
5355 pg_data_t *pgdat = NODE_DATA(nid);
5356 free_area_init_node(nid, NULL,
5357 find_min_pfn_for_node(nid), NULL);
5359 /* Any memory on that node */
5360 if (pgdat->node_present_pages)
5361 node_set_state(nid, N_MEMORY);
5362 check_for_memory(pgdat, nid);
5366 static int __init cmdline_parse_core(char *p, unsigned long *core)
5368 unsigned long long coremem;
5372 coremem = memparse(p, &p);
5373 *core = coremem >> PAGE_SHIFT;
5375 /* Paranoid check that UL is enough for the coremem value */
5376 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5382 * kernelcore=size sets the amount of memory for use for allocations that
5383 * cannot be reclaimed or migrated.
5385 static int __init cmdline_parse_kernelcore(char *p)
5387 return cmdline_parse_core(p, &required_kernelcore);
5391 * movablecore=size sets the amount of memory for use for allocations that
5392 * can be reclaimed or migrated.
5394 static int __init cmdline_parse_movablecore(char *p)
5396 return cmdline_parse_core(p, &required_movablecore);
5399 early_param("kernelcore", cmdline_parse_kernelcore);
5400 early_param("movablecore", cmdline_parse_movablecore);
5402 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5404 void adjust_managed_page_count(struct page *page, long count)
5406 spin_lock(&managed_page_count_lock);
5407 page_zone(page)->managed_pages += count;
5408 totalram_pages += count;
5409 #ifdef CONFIG_HIGHMEM
5410 if (PageHighMem(page))
5411 totalhigh_pages += count;
5413 spin_unlock(&managed_page_count_lock);
5415 EXPORT_SYMBOL(adjust_managed_page_count);
5417 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5420 unsigned long pages = 0;
5422 start = (void *)PAGE_ALIGN((unsigned long)start);
5423 end = (void *)((unsigned long)end & PAGE_MASK);
5424 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5425 if ((unsigned int)poison <= 0xFF)
5426 memset(pos, poison, PAGE_SIZE);
5427 free_reserved_page(virt_to_page(pos));
5431 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5432 s, pages << (PAGE_SHIFT - 10), start, end);
5436 EXPORT_SYMBOL(free_reserved_area);
5438 #ifdef CONFIG_HIGHMEM
5439 void free_highmem_page(struct page *page)
5441 __free_reserved_page(page);
5443 page_zone(page)->managed_pages++;
5449 void __init mem_init_print_info(const char *str)
5451 unsigned long physpages, codesize, datasize, rosize, bss_size;
5452 unsigned long init_code_size, init_data_size;
5454 physpages = get_num_physpages();
5455 codesize = _etext - _stext;
5456 datasize = _edata - _sdata;
5457 rosize = __end_rodata - __start_rodata;
5458 bss_size = __bss_stop - __bss_start;
5459 init_data_size = __init_end - __init_begin;
5460 init_code_size = _einittext - _sinittext;
5463 * Detect special cases and adjust section sizes accordingly:
5464 * 1) .init.* may be embedded into .data sections
5465 * 2) .init.text.* may be out of [__init_begin, __init_end],
5466 * please refer to arch/tile/kernel/vmlinux.lds.S.
5467 * 3) .rodata.* may be embedded into .text or .data sections.
5469 #define adj_init_size(start, end, size, pos, adj) \
5471 if (start <= pos && pos < end && size > adj) \
5475 adj_init_size(__init_begin, __init_end, init_data_size,
5476 _sinittext, init_code_size);
5477 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
5478 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
5479 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
5480 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
5482 #undef adj_init_size
5484 printk("Memory: %luK/%luK available "
5485 "(%luK kernel code, %luK rwdata, %luK rodata, "
5486 "%luK init, %luK bss, %luK reserved"
5487 #ifdef CONFIG_HIGHMEM
5491 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
5492 codesize >> 10, datasize >> 10, rosize >> 10,
5493 (init_data_size + init_code_size) >> 10, bss_size >> 10,
5494 (physpages - totalram_pages) << (PAGE_SHIFT-10),
5495 #ifdef CONFIG_HIGHMEM
5496 totalhigh_pages << (PAGE_SHIFT-10),
5498 str ? ", " : "", str ? str : "");
5502 * set_dma_reserve - set the specified number of pages reserved in the first zone
5503 * @new_dma_reserve: The number of pages to mark reserved
5505 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5506 * In the DMA zone, a significant percentage may be consumed by kernel image
5507 * and other unfreeable allocations which can skew the watermarks badly. This
5508 * function may optionally be used to account for unfreeable pages in the
5509 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5510 * smaller per-cpu batchsize.
5512 void __init set_dma_reserve(unsigned long new_dma_reserve)
5514 dma_reserve = new_dma_reserve;
5517 void __init free_area_init(unsigned long *zones_size)
5519 free_area_init_node(0, zones_size,
5520 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5523 static int page_alloc_cpu_notify(struct notifier_block *self,
5524 unsigned long action, void *hcpu)
5526 int cpu = (unsigned long)hcpu;
5528 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5529 lru_add_drain_cpu(cpu);
5533 * Spill the event counters of the dead processor
5534 * into the current processors event counters.
5535 * This artificially elevates the count of the current
5538 vm_events_fold_cpu(cpu);
5541 * Zero the differential counters of the dead processor
5542 * so that the vm statistics are consistent.
5544 * This is only okay since the processor is dead and cannot
5545 * race with what we are doing.
5547 cpu_vm_stats_fold(cpu);
5552 void __init page_alloc_init(void)
5554 hotcpu_notifier(page_alloc_cpu_notify, 0);
5558 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5559 * or min_free_kbytes changes.
5561 static void calculate_totalreserve_pages(void)
5563 struct pglist_data *pgdat;
5564 unsigned long reserve_pages = 0;
5565 enum zone_type i, j;
5567 for_each_online_pgdat(pgdat) {
5568 for (i = 0; i < MAX_NR_ZONES; i++) {
5569 struct zone *zone = pgdat->node_zones + i;
5570 unsigned long max = 0;
5572 /* Find valid and maximum lowmem_reserve in the zone */
5573 for (j = i; j < MAX_NR_ZONES; j++) {
5574 if (zone->lowmem_reserve[j] > max)
5575 max = zone->lowmem_reserve[j];
5578 /* we treat the high watermark as reserved pages. */
5579 max += high_wmark_pages(zone);
5581 if (max > zone->managed_pages)
5582 max = zone->managed_pages;
5583 reserve_pages += max;
5585 * Lowmem reserves are not available to
5586 * GFP_HIGHUSER page cache allocations and
5587 * kswapd tries to balance zones to their high
5588 * watermark. As a result, neither should be
5589 * regarded as dirtyable memory, to prevent a
5590 * situation where reclaim has to clean pages
5591 * in order to balance the zones.
5593 zone->dirty_balance_reserve = max;
5596 dirty_balance_reserve = reserve_pages;
5597 totalreserve_pages = reserve_pages;
5601 * setup_per_zone_lowmem_reserve - called whenever
5602 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5603 * has a correct pages reserved value, so an adequate number of
5604 * pages are left in the zone after a successful __alloc_pages().
5606 static void setup_per_zone_lowmem_reserve(void)
5608 struct pglist_data *pgdat;
5609 enum zone_type j, idx;
5611 for_each_online_pgdat(pgdat) {
5612 for (j = 0; j < MAX_NR_ZONES; j++) {
5613 struct zone *zone = pgdat->node_zones + j;
5614 unsigned long managed_pages = zone->managed_pages;
5616 zone->lowmem_reserve[j] = 0;
5620 struct zone *lower_zone;
5624 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5625 sysctl_lowmem_reserve_ratio[idx] = 1;
5627 lower_zone = pgdat->node_zones + idx;
5628 lower_zone->lowmem_reserve[j] = managed_pages /
5629 sysctl_lowmem_reserve_ratio[idx];
5630 managed_pages += lower_zone->managed_pages;
5635 /* update totalreserve_pages */
5636 calculate_totalreserve_pages();
5639 static void __setup_per_zone_wmarks(void)
5641 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5642 unsigned long lowmem_pages = 0;
5644 unsigned long flags;
5646 /* Calculate total number of !ZONE_HIGHMEM pages */
5647 for_each_zone(zone) {
5648 if (!is_highmem(zone))
5649 lowmem_pages += zone->managed_pages;
5652 for_each_zone(zone) {
5655 spin_lock_irqsave(&zone->lock, flags);
5656 tmp = (u64)pages_min * zone->managed_pages;
5657 do_div(tmp, lowmem_pages);
5658 if (is_highmem(zone)) {
5660 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5661 * need highmem pages, so cap pages_min to a small
5664 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5665 * deltas controls asynch page reclaim, and so should
5666 * not be capped for highmem.
5668 unsigned long min_pages;
5670 min_pages = zone->managed_pages / 1024;
5671 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
5672 zone->watermark[WMARK_MIN] = min_pages;
5675 * If it's a lowmem zone, reserve a number of pages
5676 * proportionate to the zone's size.
5678 zone->watermark[WMARK_MIN] = tmp;
5681 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5682 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5684 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
5685 high_wmark_pages(zone) -
5686 low_wmark_pages(zone) -
5687 zone_page_state(zone, NR_ALLOC_BATCH));
5689 setup_zone_migrate_reserve(zone);
5690 spin_unlock_irqrestore(&zone->lock, flags);
5693 /* update totalreserve_pages */
5694 calculate_totalreserve_pages();
5698 * setup_per_zone_wmarks - called when min_free_kbytes changes
5699 * or when memory is hot-{added|removed}
5701 * Ensures that the watermark[min,low,high] values for each zone are set
5702 * correctly with respect to min_free_kbytes.
5704 void setup_per_zone_wmarks(void)
5706 mutex_lock(&zonelists_mutex);
5707 __setup_per_zone_wmarks();
5708 mutex_unlock(&zonelists_mutex);
5712 * The inactive anon list should be small enough that the VM never has to
5713 * do too much work, but large enough that each inactive page has a chance
5714 * to be referenced again before it is swapped out.
5716 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5717 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5718 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5719 * the anonymous pages are kept on the inactive list.
5722 * memory ratio inactive anon
5723 * -------------------------------------
5732 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5734 unsigned int gb, ratio;
5736 /* Zone size in gigabytes */
5737 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
5739 ratio = int_sqrt(10 * gb);
5743 zone->inactive_ratio = ratio;
5746 static void __meminit setup_per_zone_inactive_ratio(void)
5751 calculate_zone_inactive_ratio(zone);
5755 * Initialise min_free_kbytes.
5757 * For small machines we want it small (128k min). For large machines
5758 * we want it large (64MB max). But it is not linear, because network
5759 * bandwidth does not increase linearly with machine size. We use
5761 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5762 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5778 int __meminit init_per_zone_wmark_min(void)
5780 unsigned long lowmem_kbytes;
5781 int new_min_free_kbytes;
5783 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5784 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5786 if (new_min_free_kbytes > user_min_free_kbytes) {
5787 min_free_kbytes = new_min_free_kbytes;
5788 if (min_free_kbytes < 128)
5789 min_free_kbytes = 128;
5790 if (min_free_kbytes > 65536)
5791 min_free_kbytes = 65536;
5793 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5794 new_min_free_kbytes, user_min_free_kbytes);
5796 setup_per_zone_wmarks();
5797 refresh_zone_stat_thresholds();
5798 setup_per_zone_lowmem_reserve();
5799 setup_per_zone_inactive_ratio();
5802 module_init(init_per_zone_wmark_min)
5805 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5806 * that we can call two helper functions whenever min_free_kbytes
5809 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
5810 void __user *buffer, size_t *length, loff_t *ppos)
5814 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5819 user_min_free_kbytes = min_free_kbytes;
5820 setup_per_zone_wmarks();
5826 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
5827 void __user *buffer, size_t *length, loff_t *ppos)
5832 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5837 zone->min_unmapped_pages = (zone->managed_pages *
5838 sysctl_min_unmapped_ratio) / 100;
5842 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
5843 void __user *buffer, size_t *length, loff_t *ppos)
5848 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5853 zone->min_slab_pages = (zone->managed_pages *
5854 sysctl_min_slab_ratio) / 100;
5860 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5861 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5862 * whenever sysctl_lowmem_reserve_ratio changes.
5864 * The reserve ratio obviously has absolutely no relation with the
5865 * minimum watermarks. The lowmem reserve ratio can only make sense
5866 * if in function of the boot time zone sizes.
5868 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
5869 void __user *buffer, size_t *length, loff_t *ppos)
5871 proc_dointvec_minmax(table, write, buffer, length, ppos);
5872 setup_per_zone_lowmem_reserve();
5877 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5878 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5879 * pagelist can have before it gets flushed back to buddy allocator.
5881 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
5882 void __user *buffer, size_t *length, loff_t *ppos)
5885 int old_percpu_pagelist_fraction;
5888 mutex_lock(&pcp_batch_high_lock);
5889 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
5891 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5892 if (!write || ret < 0)
5895 /* Sanity checking to avoid pcp imbalance */
5896 if (percpu_pagelist_fraction &&
5897 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
5898 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
5904 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
5907 for_each_populated_zone(zone) {
5910 for_each_possible_cpu(cpu)
5911 pageset_set_high_and_batch(zone,
5912 per_cpu_ptr(zone->pageset, cpu));
5915 mutex_unlock(&pcp_batch_high_lock);
5919 int hashdist = HASHDIST_DEFAULT;
5922 static int __init set_hashdist(char *str)
5926 hashdist = simple_strtoul(str, &str, 0);
5929 __setup("hashdist=", set_hashdist);
5933 * allocate a large system hash table from bootmem
5934 * - it is assumed that the hash table must contain an exact power-of-2
5935 * quantity of entries
5936 * - limit is the number of hash buckets, not the total allocation size
5938 void *__init alloc_large_system_hash(const char *tablename,
5939 unsigned long bucketsize,
5940 unsigned long numentries,
5943 unsigned int *_hash_shift,
5944 unsigned int *_hash_mask,
5945 unsigned long low_limit,
5946 unsigned long high_limit)
5948 unsigned long long max = high_limit;
5949 unsigned long log2qty, size;
5952 /* allow the kernel cmdline to have a say */
5954 /* round applicable memory size up to nearest megabyte */
5955 numentries = nr_kernel_pages;
5957 /* It isn't necessary when PAGE_SIZE >= 1MB */
5958 if (PAGE_SHIFT < 20)
5959 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
5961 /* limit to 1 bucket per 2^scale bytes of low memory */
5962 if (scale > PAGE_SHIFT)
5963 numentries >>= (scale - PAGE_SHIFT);
5965 numentries <<= (PAGE_SHIFT - scale);
5967 /* Make sure we've got at least a 0-order allocation.. */
5968 if (unlikely(flags & HASH_SMALL)) {
5969 /* Makes no sense without HASH_EARLY */
5970 WARN_ON(!(flags & HASH_EARLY));
5971 if (!(numentries >> *_hash_shift)) {
5972 numentries = 1UL << *_hash_shift;
5973 BUG_ON(!numentries);
5975 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5976 numentries = PAGE_SIZE / bucketsize;
5978 numentries = roundup_pow_of_two(numentries);
5980 /* limit allocation size to 1/16 total memory by default */
5982 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5983 do_div(max, bucketsize);
5985 max = min(max, 0x80000000ULL);
5987 if (numentries < low_limit)
5988 numentries = low_limit;
5989 if (numentries > max)
5992 log2qty = ilog2(numentries);
5995 size = bucketsize << log2qty;
5996 if (flags & HASH_EARLY)
5997 table = memblock_virt_alloc_nopanic(size, 0);
5999 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6002 * If bucketsize is not a power-of-two, we may free
6003 * some pages at the end of hash table which
6004 * alloc_pages_exact() automatically does
6006 if (get_order(size) < MAX_ORDER) {
6007 table = alloc_pages_exact(size, GFP_ATOMIC);
6008 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6011 } while (!table && size > PAGE_SIZE && --log2qty);
6014 panic("Failed to allocate %s hash table\n", tablename);
6016 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6019 ilog2(size) - PAGE_SHIFT,
6023 *_hash_shift = log2qty;
6025 *_hash_mask = (1 << log2qty) - 1;
6030 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6031 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6034 #ifdef CONFIG_SPARSEMEM
6035 return __pfn_to_section(pfn)->pageblock_flags;
6037 return zone->pageblock_flags;
6038 #endif /* CONFIG_SPARSEMEM */
6041 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6043 #ifdef CONFIG_SPARSEMEM
6044 pfn &= (PAGES_PER_SECTION-1);
6045 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6047 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6048 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6049 #endif /* CONFIG_SPARSEMEM */
6053 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
6054 * @page: The page within the block of interest
6055 * @start_bitidx: The first bit of interest to retrieve
6056 * @end_bitidx: The last bit of interest
6057 * returns pageblock_bits flags
6059 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6060 unsigned long end_bitidx,
6064 unsigned long *bitmap;
6065 unsigned long bitidx, word_bitidx;
6068 zone = page_zone(page);
6069 bitmap = get_pageblock_bitmap(zone, pfn);
6070 bitidx = pfn_to_bitidx(zone, pfn);
6071 word_bitidx = bitidx / BITS_PER_LONG;
6072 bitidx &= (BITS_PER_LONG-1);
6074 word = bitmap[word_bitidx];
6075 bitidx += end_bitidx;
6076 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6080 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6081 * @page: The page within the block of interest
6082 * @start_bitidx: The first bit of interest
6083 * @end_bitidx: The last bit of interest
6084 * @flags: The flags to set
6086 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6088 unsigned long end_bitidx,
6092 unsigned long *bitmap;
6093 unsigned long bitidx, word_bitidx;
6094 unsigned long old_word, word;
6096 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6098 zone = page_zone(page);
6099 bitmap = get_pageblock_bitmap(zone, pfn);
6100 bitidx = pfn_to_bitidx(zone, pfn);
6101 word_bitidx = bitidx / BITS_PER_LONG;
6102 bitidx &= (BITS_PER_LONG-1);
6104 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6106 bitidx += end_bitidx;
6107 mask <<= (BITS_PER_LONG - bitidx - 1);
6108 flags <<= (BITS_PER_LONG - bitidx - 1);
6110 word = ACCESS_ONCE(bitmap[word_bitidx]);
6112 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6113 if (word == old_word)
6120 * This function checks whether pageblock includes unmovable pages or not.
6121 * If @count is not zero, it is okay to include less @count unmovable pages
6123 * PageLRU check without isolation or lru_lock could race so that
6124 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6125 * expect this function should be exact.
6127 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6128 bool skip_hwpoisoned_pages)
6130 unsigned long pfn, iter, found;
6134 * For avoiding noise data, lru_add_drain_all() should be called
6135 * If ZONE_MOVABLE, the zone never contains unmovable pages
6137 if (zone_idx(zone) == ZONE_MOVABLE)
6139 mt = get_pageblock_migratetype(page);
6140 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6143 pfn = page_to_pfn(page);
6144 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6145 unsigned long check = pfn + iter;
6147 if (!pfn_valid_within(check))
6150 page = pfn_to_page(check);
6153 * Hugepages are not in LRU lists, but they're movable.
6154 * We need not scan over tail pages bacause we don't
6155 * handle each tail page individually in migration.
6157 if (PageHuge(page)) {
6158 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6163 * We can't use page_count without pin a page
6164 * because another CPU can free compound page.
6165 * This check already skips compound tails of THP
6166 * because their page->_count is zero at all time.
6168 if (!atomic_read(&page->_count)) {
6169 if (PageBuddy(page))
6170 iter += (1 << page_order(page)) - 1;
6175 * The HWPoisoned page may be not in buddy system, and
6176 * page_count() is not 0.
6178 if (skip_hwpoisoned_pages && PageHWPoison(page))
6184 * If there are RECLAIMABLE pages, we need to check it.
6185 * But now, memory offline itself doesn't call shrink_slab()
6186 * and it still to be fixed.
6189 * If the page is not RAM, page_count()should be 0.
6190 * we don't need more check. This is an _used_ not-movable page.
6192 * The problematic thing here is PG_reserved pages. PG_reserved
6193 * is set to both of a memory hole page and a _used_ kernel
6202 bool is_pageblock_removable_nolock(struct page *page)
6208 * We have to be careful here because we are iterating over memory
6209 * sections which are not zone aware so we might end up outside of
6210 * the zone but still within the section.
6211 * We have to take care about the node as well. If the node is offline
6212 * its NODE_DATA will be NULL - see page_zone.
6214 if (!node_online(page_to_nid(page)))
6217 zone = page_zone(page);
6218 pfn = page_to_pfn(page);
6219 if (!zone_spans_pfn(zone, pfn))
6222 return !has_unmovable_pages(zone, page, 0, true);
6227 static unsigned long pfn_max_align_down(unsigned long pfn)
6229 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6230 pageblock_nr_pages) - 1);
6233 static unsigned long pfn_max_align_up(unsigned long pfn)
6235 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6236 pageblock_nr_pages));
6239 /* [start, end) must belong to a single zone. */
6240 static int __alloc_contig_migrate_range(struct compact_control *cc,
6241 unsigned long start, unsigned long end)
6243 /* This function is based on compact_zone() from compaction.c. */
6244 unsigned long nr_reclaimed;
6245 unsigned long pfn = start;
6246 unsigned int tries = 0;
6251 while (pfn < end || !list_empty(&cc->migratepages)) {
6252 if (fatal_signal_pending(current)) {
6257 if (list_empty(&cc->migratepages)) {
6258 cc->nr_migratepages = 0;
6259 pfn = isolate_migratepages_range(cc->zone, cc,
6266 } else if (++tries == 5) {
6267 ret = ret < 0 ? ret : -EBUSY;
6271 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6273 cc->nr_migratepages -= nr_reclaimed;
6275 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6276 NULL, 0, cc->mode, MR_CMA);
6279 putback_movable_pages(&cc->migratepages);
6286 * alloc_contig_range() -- tries to allocate given range of pages
6287 * @start: start PFN to allocate
6288 * @end: one-past-the-last PFN to allocate
6289 * @migratetype: migratetype of the underlaying pageblocks (either
6290 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6291 * in range must have the same migratetype and it must
6292 * be either of the two.
6294 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6295 * aligned, however it's the caller's responsibility to guarantee that
6296 * we are the only thread that changes migrate type of pageblocks the
6299 * The PFN range must belong to a single zone.
6301 * Returns zero on success or negative error code. On success all
6302 * pages which PFN is in [start, end) are allocated for the caller and
6303 * need to be freed with free_contig_range().
6305 int alloc_contig_range(unsigned long start, unsigned long end,
6306 unsigned migratetype)
6308 unsigned long outer_start, outer_end;
6311 struct compact_control cc = {
6312 .nr_migratepages = 0,
6314 .zone = page_zone(pfn_to_page(start)),
6315 .mode = MIGRATE_SYNC,
6316 .ignore_skip_hint = true,
6318 INIT_LIST_HEAD(&cc.migratepages);
6321 * What we do here is we mark all pageblocks in range as
6322 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6323 * have different sizes, and due to the way page allocator
6324 * work, we align the range to biggest of the two pages so
6325 * that page allocator won't try to merge buddies from
6326 * different pageblocks and change MIGRATE_ISOLATE to some
6327 * other migration type.
6329 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6330 * migrate the pages from an unaligned range (ie. pages that
6331 * we are interested in). This will put all the pages in
6332 * range back to page allocator as MIGRATE_ISOLATE.
6334 * When this is done, we take the pages in range from page
6335 * allocator removing them from the buddy system. This way
6336 * page allocator will never consider using them.
6338 * This lets us mark the pageblocks back as
6339 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6340 * aligned range but not in the unaligned, original range are
6341 * put back to page allocator so that buddy can use them.
6344 ret = start_isolate_page_range(pfn_max_align_down(start),
6345 pfn_max_align_up(end), migratetype,
6350 ret = __alloc_contig_migrate_range(&cc, start, end);
6355 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6356 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6357 * more, all pages in [start, end) are free in page allocator.
6358 * What we are going to do is to allocate all pages from
6359 * [start, end) (that is remove them from page allocator).
6361 * The only problem is that pages at the beginning and at the
6362 * end of interesting range may be not aligned with pages that
6363 * page allocator holds, ie. they can be part of higher order
6364 * pages. Because of this, we reserve the bigger range and
6365 * once this is done free the pages we are not interested in.
6367 * We don't have to hold zone->lock here because the pages are
6368 * isolated thus they won't get removed from buddy.
6371 lru_add_drain_all();
6375 outer_start = start;
6376 while (!PageBuddy(pfn_to_page(outer_start))) {
6377 if (++order >= MAX_ORDER) {
6381 outer_start &= ~0UL << order;
6384 /* Make sure the range is really isolated. */
6385 if (test_pages_isolated(outer_start, end, false)) {
6386 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
6393 /* Grab isolated pages from freelists. */
6394 outer_end = isolate_freepages_range(&cc, outer_start, end);
6400 /* Free head and tail (if any) */
6401 if (start != outer_start)
6402 free_contig_range(outer_start, start - outer_start);
6403 if (end != outer_end)
6404 free_contig_range(end, outer_end - end);
6407 undo_isolate_page_range(pfn_max_align_down(start),
6408 pfn_max_align_up(end), migratetype);
6412 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6414 unsigned int count = 0;
6416 for (; nr_pages--; pfn++) {
6417 struct page *page = pfn_to_page(pfn);
6419 count += page_count(page) != 1;
6422 WARN(count != 0, "%d pages are still in use!\n", count);
6426 #ifdef CONFIG_MEMORY_HOTPLUG
6428 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6429 * page high values need to be recalulated.
6431 void __meminit zone_pcp_update(struct zone *zone)
6434 mutex_lock(&pcp_batch_high_lock);
6435 for_each_possible_cpu(cpu)
6436 pageset_set_high_and_batch(zone,
6437 per_cpu_ptr(zone->pageset, cpu));
6438 mutex_unlock(&pcp_batch_high_lock);
6442 void zone_pcp_reset(struct zone *zone)
6444 unsigned long flags;
6446 struct per_cpu_pageset *pset;
6448 /* avoid races with drain_pages() */
6449 local_irq_save(flags);
6450 if (zone->pageset != &boot_pageset) {
6451 for_each_online_cpu(cpu) {
6452 pset = per_cpu_ptr(zone->pageset, cpu);
6453 drain_zonestat(zone, pset);
6455 free_percpu(zone->pageset);
6456 zone->pageset = &boot_pageset;
6458 local_irq_restore(flags);
6461 #ifdef CONFIG_MEMORY_HOTREMOVE
6463 * All pages in the range must be isolated before calling this.
6466 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6470 unsigned int order, i;
6472 unsigned long flags;
6473 /* find the first valid pfn */
6474 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6479 zone = page_zone(pfn_to_page(pfn));
6480 spin_lock_irqsave(&zone->lock, flags);
6482 while (pfn < end_pfn) {
6483 if (!pfn_valid(pfn)) {
6487 page = pfn_to_page(pfn);
6489 * The HWPoisoned page may be not in buddy system, and
6490 * page_count() is not 0.
6492 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
6494 SetPageReserved(page);
6498 BUG_ON(page_count(page));
6499 BUG_ON(!PageBuddy(page));
6500 order = page_order(page);
6501 #ifdef CONFIG_DEBUG_VM
6502 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6503 pfn, 1 << order, end_pfn);
6505 list_del(&page->lru);
6506 rmv_page_order(page);
6507 zone->free_area[order].nr_free--;
6508 for (i = 0; i < (1 << order); i++)
6509 SetPageReserved((page+i));
6510 pfn += (1 << order);
6512 spin_unlock_irqrestore(&zone->lock, flags);
6516 #ifdef CONFIG_MEMORY_FAILURE
6517 bool is_free_buddy_page(struct page *page)
6519 struct zone *zone = page_zone(page);
6520 unsigned long pfn = page_to_pfn(page);
6521 unsigned long flags;
6524 spin_lock_irqsave(&zone->lock, flags);
6525 for (order = 0; order < MAX_ORDER; order++) {
6526 struct page *page_head = page - (pfn & ((1 << order) - 1));
6528 if (PageBuddy(page_head) && page_order(page_head) >= order)
6531 spin_unlock_irqrestore(&zone->lock, flags);
6533 return order < MAX_ORDER;
6537 static const struct trace_print_flags pageflag_names[] = {
6538 {1UL << PG_locked, "locked" },
6539 {1UL << PG_error, "error" },
6540 {1UL << PG_referenced, "referenced" },
6541 {1UL << PG_uptodate, "uptodate" },
6542 {1UL << PG_dirty, "dirty" },
6543 {1UL << PG_lru, "lru" },
6544 {1UL << PG_active, "active" },
6545 {1UL << PG_slab, "slab" },
6546 {1UL << PG_owner_priv_1, "owner_priv_1" },
6547 {1UL << PG_arch_1, "arch_1" },
6548 {1UL << PG_reserved, "reserved" },
6549 {1UL << PG_private, "private" },
6550 {1UL << PG_private_2, "private_2" },
6551 {1UL << PG_writeback, "writeback" },
6552 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6553 {1UL << PG_head, "head" },
6554 {1UL << PG_tail, "tail" },
6556 {1UL << PG_compound, "compound" },
6558 {1UL << PG_swapcache, "swapcache" },
6559 {1UL << PG_mappedtodisk, "mappedtodisk" },
6560 {1UL << PG_reclaim, "reclaim" },
6561 {1UL << PG_swapbacked, "swapbacked" },
6562 {1UL << PG_unevictable, "unevictable" },
6564 {1UL << PG_mlocked, "mlocked" },
6566 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6567 {1UL << PG_uncached, "uncached" },
6569 #ifdef CONFIG_MEMORY_FAILURE
6570 {1UL << PG_hwpoison, "hwpoison" },
6572 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6573 {1UL << PG_compound_lock, "compound_lock" },
6577 static void dump_page_flags(unsigned long flags)
6579 const char *delim = "";
6583 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
6585 printk(KERN_ALERT "page flags: %#lx(", flags);
6587 /* remove zone id */
6588 flags &= (1UL << NR_PAGEFLAGS) - 1;
6590 for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) {
6592 mask = pageflag_names[i].mask;
6593 if ((flags & mask) != mask)
6597 printk("%s%s", delim, pageflag_names[i].name);
6601 /* check for left over flags */
6603 printk("%s%#lx", delim, flags);
6608 void dump_page_badflags(struct page *page, const char *reason,
6609 unsigned long badflags)
6612 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6613 page, atomic_read(&page->_count), page_mapcount(page),
6614 page->mapping, page->index);
6615 dump_page_flags(page->flags);
6617 pr_alert("page dumped because: %s\n", reason);
6618 if (page->flags & badflags) {
6619 pr_alert("bad because of flags:\n");
6620 dump_page_flags(page->flags & badflags);
6622 mem_cgroup_print_bad_page(page);
6625 void dump_page(struct page *page, const char *reason)
6627 dump_page_badflags(page, reason, 0);
6629 EXPORT_SYMBOL(dump_page);