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/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/prefetch.h>
58 #include <linux/mm_inline.h>
59 #include <linux/migrate.h>
60 #include <linux/page_ext.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/page_owner.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_);
88 int _node_numa_mem_[MAX_NUMNODES];
92 * Array of node states.
94 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
95 [N_POSSIBLE] = NODE_MASK_ALL,
96 [N_ONLINE] = { { [0] = 1UL } },
98 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
100 [N_HIGH_MEMORY] = { { [0] = 1UL } },
102 #ifdef CONFIG_MOVABLE_NODE
103 [N_MEMORY] = { { [0] = 1UL } },
105 [N_CPU] = { { [0] = 1UL } },
108 EXPORT_SYMBOL(node_states);
110 /* Protect totalram_pages and zone->managed_pages */
111 static DEFINE_SPINLOCK(managed_page_count_lock);
113 unsigned long totalram_pages __read_mostly;
114 unsigned long totalreserve_pages __read_mostly;
115 unsigned long totalcma_pages __read_mostly;
117 * When calculating the number of globally allowed dirty pages, there
118 * is a certain number of per-zone reserves that should not be
119 * considered dirtyable memory. This is the sum of those reserves
120 * over all existing zones that contribute dirtyable memory.
122 unsigned long dirty_balance_reserve __read_mostly;
124 int percpu_pagelist_fraction;
125 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
127 #ifdef CONFIG_PM_SLEEP
129 * The following functions are used by the suspend/hibernate code to temporarily
130 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
131 * while devices are suspended. To avoid races with the suspend/hibernate code,
132 * they should always be called with pm_mutex held (gfp_allowed_mask also should
133 * only be modified with pm_mutex held, unless the suspend/hibernate code is
134 * guaranteed not to run in parallel with that modification).
137 static gfp_t saved_gfp_mask;
139 void pm_restore_gfp_mask(void)
141 WARN_ON(!mutex_is_locked(&pm_mutex));
142 if (saved_gfp_mask) {
143 gfp_allowed_mask = saved_gfp_mask;
148 void pm_restrict_gfp_mask(void)
150 WARN_ON(!mutex_is_locked(&pm_mutex));
151 WARN_ON(saved_gfp_mask);
152 saved_gfp_mask = gfp_allowed_mask;
153 gfp_allowed_mask &= ~GFP_IOFS;
156 bool pm_suspended_storage(void)
158 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
162 #endif /* CONFIG_PM_SLEEP */
164 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
165 int pageblock_order __read_mostly;
168 static void __free_pages_ok(struct page *page, unsigned int order);
171 * results with 256, 32 in the lowmem_reserve sysctl:
172 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
173 * 1G machine -> (16M dma, 784M normal, 224M high)
174 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
175 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
176 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
178 * TBD: should special case ZONE_DMA32 machines here - in those we normally
179 * don't need any ZONE_NORMAL reservation
181 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
182 #ifdef CONFIG_ZONE_DMA
185 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 EXPORT_SYMBOL(totalram_pages);
196 static char * const zone_names[MAX_NR_ZONES] = {
197 #ifdef CONFIG_ZONE_DMA
200 #ifdef CONFIG_ZONE_DMA32
204 #ifdef CONFIG_HIGHMEM
210 int min_free_kbytes = 1024;
211 int user_min_free_kbytes = -1;
213 static unsigned long __meminitdata nr_kernel_pages;
214 static unsigned long __meminitdata nr_all_pages;
215 static unsigned long __meminitdata dma_reserve;
217 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
218 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
219 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
220 static unsigned long __initdata required_kernelcore;
221 static unsigned long __initdata required_movablecore;
222 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
224 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
226 EXPORT_SYMBOL(movable_zone);
227 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
230 int nr_node_ids __read_mostly = MAX_NUMNODES;
231 int nr_online_nodes __read_mostly = 1;
232 EXPORT_SYMBOL(nr_node_ids);
233 EXPORT_SYMBOL(nr_online_nodes);
236 int page_group_by_mobility_disabled __read_mostly;
238 void set_pageblock_migratetype(struct page *page, int migratetype)
240 if (unlikely(page_group_by_mobility_disabled &&
241 migratetype < MIGRATE_PCPTYPES))
242 migratetype = MIGRATE_UNMOVABLE;
244 set_pageblock_flags_group(page, (unsigned long)migratetype,
245 PB_migrate, PB_migrate_end);
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 #ifdef CONFIG_DEBUG_PAGEALLOC
384 unsigned int _debug_guardpage_minorder;
385 bool _debug_pagealloc_enabled __read_mostly;
386 bool _debug_guardpage_enabled __read_mostly;
388 static int __init early_debug_pagealloc(char *buf)
393 if (strcmp(buf, "on") == 0)
394 _debug_pagealloc_enabled = true;
398 early_param("debug_pagealloc", early_debug_pagealloc);
400 static bool need_debug_guardpage(void)
402 /* If we don't use debug_pagealloc, we don't need guard page */
403 if (!debug_pagealloc_enabled())
409 static void init_debug_guardpage(void)
411 if (!debug_pagealloc_enabled())
414 _debug_guardpage_enabled = true;
417 struct page_ext_operations debug_guardpage_ops = {
418 .need = need_debug_guardpage,
419 .init = init_debug_guardpage,
422 static int __init debug_guardpage_minorder_setup(char *buf)
426 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
427 printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
430 _debug_guardpage_minorder = res;
431 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
434 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
436 static inline void set_page_guard(struct zone *zone, struct page *page,
437 unsigned int order, int migratetype)
439 struct page_ext *page_ext;
441 if (!debug_guardpage_enabled())
444 page_ext = lookup_page_ext(page);
445 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
447 INIT_LIST_HEAD(&page->lru);
448 set_page_private(page, order);
449 /* Guard pages are not available for any usage */
450 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
453 static inline void clear_page_guard(struct zone *zone, struct page *page,
454 unsigned int order, int migratetype)
456 struct page_ext *page_ext;
458 if (!debug_guardpage_enabled())
461 page_ext = lookup_page_ext(page);
462 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
464 set_page_private(page, 0);
465 if (!is_migrate_isolate(migratetype))
466 __mod_zone_freepage_state(zone, (1 << order), migratetype);
469 struct page_ext_operations debug_guardpage_ops = { NULL, };
470 static inline void set_page_guard(struct zone *zone, struct page *page,
471 unsigned int order, int migratetype) {}
472 static inline void clear_page_guard(struct zone *zone, struct page *page,
473 unsigned int order, int migratetype) {}
476 static inline void set_page_order(struct page *page, unsigned int order)
478 set_page_private(page, order);
479 __SetPageBuddy(page);
482 static inline void rmv_page_order(struct page *page)
484 __ClearPageBuddy(page);
485 set_page_private(page, 0);
489 * This function checks whether a page is free && is the buddy
490 * we can do coalesce a page and its buddy if
491 * (a) the buddy is not in a hole &&
492 * (b) the buddy is in the buddy system &&
493 * (c) a page and its buddy have the same order &&
494 * (d) a page and its buddy are in the same zone.
496 * For recording whether a page is in the buddy system, we set ->_mapcount
497 * PAGE_BUDDY_MAPCOUNT_VALUE.
498 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
499 * serialized by zone->lock.
501 * For recording page's order, we use page_private(page).
503 static inline int page_is_buddy(struct page *page, struct page *buddy,
506 if (!pfn_valid_within(page_to_pfn(buddy)))
509 if (page_is_guard(buddy) && page_order(buddy) == order) {
510 if (page_zone_id(page) != page_zone_id(buddy))
513 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
518 if (PageBuddy(buddy) && page_order(buddy) == order) {
520 * zone check is done late to avoid uselessly
521 * calculating zone/node ids for pages that could
524 if (page_zone_id(page) != page_zone_id(buddy))
527 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
535 * Freeing function for a buddy system allocator.
537 * The concept of a buddy system is to maintain direct-mapped table
538 * (containing bit values) for memory blocks of various "orders".
539 * The bottom level table contains the map for the smallest allocatable
540 * units of memory (here, pages), and each level above it describes
541 * pairs of units from the levels below, hence, "buddies".
542 * At a high level, all that happens here is marking the table entry
543 * at the bottom level available, and propagating the changes upward
544 * as necessary, plus some accounting needed to play nicely with other
545 * parts of the VM system.
546 * At each level, we keep a list of pages, which are heads of continuous
547 * free pages of length of (1 << order) and marked with _mapcount
548 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
550 * So when we are allocating or freeing one, we can derive the state of the
551 * other. That is, if we allocate a small block, and both were
552 * free, the remainder of the region must be split into blocks.
553 * If a block is freed, and its buddy is also free, then this
554 * triggers coalescing into a block of larger size.
559 static inline void __free_one_page(struct page *page,
561 struct zone *zone, unsigned int order,
564 unsigned long page_idx;
565 unsigned long combined_idx;
566 unsigned long uninitialized_var(buddy_idx);
568 int max_order = MAX_ORDER;
570 VM_BUG_ON(!zone_is_initialized(zone));
571 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
573 VM_BUG_ON(migratetype == -1);
574 if (is_migrate_isolate(migratetype)) {
576 * We restrict max order of merging to prevent merge
577 * between freepages on isolate pageblock and normal
578 * pageblock. Without this, pageblock isolation
579 * could cause incorrect freepage accounting.
581 max_order = min(MAX_ORDER, pageblock_order + 1);
583 __mod_zone_freepage_state(zone, 1 << order, migratetype);
586 page_idx = pfn & ((1 << max_order) - 1);
588 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
589 VM_BUG_ON_PAGE(bad_range(zone, page), page);
591 while (order < max_order - 1) {
592 buddy_idx = __find_buddy_index(page_idx, order);
593 buddy = page + (buddy_idx - page_idx);
594 if (!page_is_buddy(page, buddy, order))
597 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
598 * merge with it and move up one order.
600 if (page_is_guard(buddy)) {
601 clear_page_guard(zone, buddy, order, migratetype);
603 list_del(&buddy->lru);
604 zone->free_area[order].nr_free--;
605 rmv_page_order(buddy);
607 combined_idx = buddy_idx & page_idx;
608 page = page + (combined_idx - page_idx);
609 page_idx = combined_idx;
612 set_page_order(page, order);
615 * If this is not the largest possible page, check if the buddy
616 * of the next-highest order is free. If it is, it's possible
617 * that pages are being freed that will coalesce soon. In case,
618 * that is happening, add the free page to the tail of the list
619 * so it's less likely to be used soon and more likely to be merged
620 * as a higher order page
622 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
623 struct page *higher_page, *higher_buddy;
624 combined_idx = buddy_idx & page_idx;
625 higher_page = page + (combined_idx - page_idx);
626 buddy_idx = __find_buddy_index(combined_idx, order + 1);
627 higher_buddy = higher_page + (buddy_idx - combined_idx);
628 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
629 list_add_tail(&page->lru,
630 &zone->free_area[order].free_list[migratetype]);
635 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
637 zone->free_area[order].nr_free++;
640 static inline int free_pages_check(struct page *page)
642 const char *bad_reason = NULL;
643 unsigned long bad_flags = 0;
645 if (unlikely(page_mapcount(page)))
646 bad_reason = "nonzero mapcount";
647 if (unlikely(page->mapping != NULL))
648 bad_reason = "non-NULL mapping";
649 if (unlikely(atomic_read(&page->_count) != 0))
650 bad_reason = "nonzero _count";
651 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
652 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
653 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
656 if (unlikely(page->mem_cgroup))
657 bad_reason = "page still charged to cgroup";
659 if (unlikely(bad_reason)) {
660 bad_page(page, bad_reason, bad_flags);
663 page_cpupid_reset_last(page);
664 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
665 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
670 * Frees a number of pages from the PCP lists
671 * Assumes all pages on list are in same zone, and of same order.
672 * count is the number of pages to free.
674 * If the zone was previously in an "all pages pinned" state then look to
675 * see if this freeing clears that state.
677 * And clear the zone's pages_scanned counter, to hold off the "all pages are
678 * pinned" detection logic.
680 static void free_pcppages_bulk(struct zone *zone, int count,
681 struct per_cpu_pages *pcp)
686 unsigned long nr_scanned;
688 spin_lock(&zone->lock);
689 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
691 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
695 struct list_head *list;
698 * Remove pages from lists in a round-robin fashion. A
699 * batch_free count is maintained that is incremented when an
700 * empty list is encountered. This is so more pages are freed
701 * off fuller lists instead of spinning excessively around empty
706 if (++migratetype == MIGRATE_PCPTYPES)
708 list = &pcp->lists[migratetype];
709 } while (list_empty(list));
711 /* This is the only non-empty list. Free them all. */
712 if (batch_free == MIGRATE_PCPTYPES)
713 batch_free = to_free;
716 int mt; /* migratetype of the to-be-freed page */
718 page = list_entry(list->prev, struct page, lru);
719 /* must delete as __free_one_page list manipulates */
720 list_del(&page->lru);
721 mt = get_freepage_migratetype(page);
722 if (unlikely(has_isolate_pageblock(zone)))
723 mt = get_pageblock_migratetype(page);
725 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
726 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
727 trace_mm_page_pcpu_drain(page, 0, mt);
728 } while (--to_free && --batch_free && !list_empty(list));
730 spin_unlock(&zone->lock);
733 static void free_one_page(struct zone *zone,
734 struct page *page, unsigned long pfn,
738 unsigned long nr_scanned;
739 spin_lock(&zone->lock);
740 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
742 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
744 if (unlikely(has_isolate_pageblock(zone) ||
745 is_migrate_isolate(migratetype))) {
746 migratetype = get_pfnblock_migratetype(page, pfn);
748 __free_one_page(page, pfn, zone, order, migratetype);
749 spin_unlock(&zone->lock);
752 static int free_tail_pages_check(struct page *head_page, struct page *page)
754 if (!IS_ENABLED(CONFIG_DEBUG_VM))
756 if (unlikely(!PageTail(page))) {
757 bad_page(page, "PageTail not set", 0);
760 if (unlikely(page->first_page != head_page)) {
761 bad_page(page, "first_page not consistent", 0);
767 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
768 unsigned long zone, int nid)
770 struct zone *z = &NODE_DATA(nid)->node_zones[zone];
772 set_page_links(page, zone, nid, pfn);
773 mminit_verify_page_links(page, zone, nid, pfn);
774 init_page_count(page);
775 page_mapcount_reset(page);
776 page_cpupid_reset_last(page);
779 * Mark the block movable so that blocks are reserved for
780 * movable at startup. This will force kernel allocations
781 * to reserve their blocks rather than leaking throughout
782 * the address space during boot when many long-lived
783 * kernel allocations are made. Later some blocks near
784 * the start are marked MIGRATE_RESERVE by
785 * setup_zone_migrate_reserve()
787 * bitmap is created for zone's valid pfn range. but memmap
788 * can be created for invalid pages (for alignment)
789 * check here not to call set_pageblock_migratetype() against
792 if ((z->zone_start_pfn <= pfn)
793 && (pfn < zone_end_pfn(z))
794 && !(pfn & (pageblock_nr_pages - 1)))
795 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
797 INIT_LIST_HEAD(&page->lru);
798 #ifdef WANT_PAGE_VIRTUAL
799 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
800 if (!is_highmem_idx(zone))
801 set_page_address(page, __va(pfn << PAGE_SHIFT));
805 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
808 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
812 * Initialised pages do not have PageReserved set. This function is
813 * called for each range allocated by the bootmem allocator and
814 * marks the pages PageReserved. The remaining valid pages are later
815 * sent to the buddy page allocator.
817 void reserve_bootmem_region(unsigned long start, unsigned long end)
819 unsigned long start_pfn = PFN_DOWN(start);
820 unsigned long end_pfn = PFN_UP(end);
822 for (; start_pfn < end_pfn; start_pfn++)
823 if (pfn_valid(start_pfn))
824 SetPageReserved(pfn_to_page(start_pfn));
827 static bool free_pages_prepare(struct page *page, unsigned int order)
829 bool compound = PageCompound(page);
832 VM_BUG_ON_PAGE(PageTail(page), page);
833 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
835 trace_mm_page_free(page, order);
836 kmemcheck_free_shadow(page, order);
837 kasan_free_pages(page, order);
840 page->mapping = NULL;
841 bad += free_pages_check(page);
842 for (i = 1; i < (1 << order); i++) {
844 bad += free_tail_pages_check(page, page + i);
845 bad += free_pages_check(page + i);
850 reset_page_owner(page, order);
852 if (!PageHighMem(page)) {
853 debug_check_no_locks_freed(page_address(page),
855 debug_check_no_obj_freed(page_address(page),
858 arch_free_page(page, order);
859 kernel_map_pages(page, 1 << order, 0);
864 static void __free_pages_ok(struct page *page, unsigned int order)
868 unsigned long pfn = page_to_pfn(page);
870 if (!free_pages_prepare(page, order))
873 migratetype = get_pfnblock_migratetype(page, pfn);
874 local_irq_save(flags);
875 __count_vm_events(PGFREE, 1 << order);
876 set_freepage_migratetype(page, migratetype);
877 free_one_page(page_zone(page), page, pfn, order, migratetype);
878 local_irq_restore(flags);
881 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
884 unsigned int nr_pages = 1 << order;
885 struct page *p = page;
889 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
891 __ClearPageReserved(p);
892 set_page_count(p, 0);
894 __ClearPageReserved(p);
895 set_page_count(p, 0);
897 page_zone(page)->managed_pages += nr_pages;
898 set_page_refcounted(page);
899 __free_pages(page, order);
903 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
904 void __init init_cma_reserved_pageblock(struct page *page)
906 unsigned i = pageblock_nr_pages;
907 struct page *p = page;
910 __ClearPageReserved(p);
911 set_page_count(p, 0);
914 set_pageblock_migratetype(page, MIGRATE_CMA);
916 if (pageblock_order >= MAX_ORDER) {
917 i = pageblock_nr_pages;
920 set_page_refcounted(p);
921 __free_pages(p, MAX_ORDER - 1);
922 p += MAX_ORDER_NR_PAGES;
923 } while (i -= MAX_ORDER_NR_PAGES);
925 set_page_refcounted(page);
926 __free_pages(page, pageblock_order);
929 adjust_managed_page_count(page, pageblock_nr_pages);
934 * The order of subdivision here is critical for the IO subsystem.
935 * Please do not alter this order without good reasons and regression
936 * testing. Specifically, as large blocks of memory are subdivided,
937 * the order in which smaller blocks are delivered depends on the order
938 * they're subdivided in this function. This is the primary factor
939 * influencing the order in which pages are delivered to the IO
940 * subsystem according to empirical testing, and this is also justified
941 * by considering the behavior of a buddy system containing a single
942 * large block of memory acted on by a series of small allocations.
943 * This behavior is a critical factor in sglist merging's success.
947 static inline void expand(struct zone *zone, struct page *page,
948 int low, int high, struct free_area *area,
951 unsigned long size = 1 << high;
957 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
959 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
960 debug_guardpage_enabled() &&
961 high < debug_guardpage_minorder()) {
963 * Mark as guard pages (or page), that will allow to
964 * merge back to allocator when buddy will be freed.
965 * Corresponding page table entries will not be touched,
966 * pages will stay not present in virtual address space
968 set_page_guard(zone, &page[size], high, migratetype);
971 list_add(&page[size].lru, &area->free_list[migratetype]);
973 set_page_order(&page[size], high);
978 * This page is about to be returned from the page allocator
980 static inline int check_new_page(struct page *page)
982 const char *bad_reason = NULL;
983 unsigned long bad_flags = 0;
985 if (unlikely(page_mapcount(page)))
986 bad_reason = "nonzero mapcount";
987 if (unlikely(page->mapping != NULL))
988 bad_reason = "non-NULL mapping";
989 if (unlikely(atomic_read(&page->_count) != 0))
990 bad_reason = "nonzero _count";
991 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
992 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
993 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
996 if (unlikely(page->mem_cgroup))
997 bad_reason = "page still charged to cgroup";
999 if (unlikely(bad_reason)) {
1000 bad_page(page, bad_reason, bad_flags);
1006 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1011 for (i = 0; i < (1 << order); i++) {
1012 struct page *p = page + i;
1013 if (unlikely(check_new_page(p)))
1017 set_page_private(page, 0);
1018 set_page_refcounted(page);
1020 arch_alloc_page(page, order);
1021 kernel_map_pages(page, 1 << order, 1);
1022 kasan_alloc_pages(page, order);
1024 if (gfp_flags & __GFP_ZERO)
1025 for (i = 0; i < (1 << order); i++)
1026 clear_highpage(page + i);
1028 if (order && (gfp_flags & __GFP_COMP))
1029 prep_compound_page(page, order);
1031 set_page_owner(page, order, gfp_flags);
1034 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was necessary to
1035 * allocate the page. The expectation is that the caller is taking
1036 * steps that will free more memory. The caller should avoid the page
1037 * being used for !PFMEMALLOC purposes.
1039 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
1045 * Go through the free lists for the given migratetype and remove
1046 * the smallest available page from the freelists
1049 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1052 unsigned int current_order;
1053 struct free_area *area;
1056 /* Find a page of the appropriate size in the preferred list */
1057 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1058 area = &(zone->free_area[current_order]);
1059 if (list_empty(&area->free_list[migratetype]))
1062 page = list_entry(area->free_list[migratetype].next,
1064 list_del(&page->lru);
1065 rmv_page_order(page);
1067 expand(zone, page, order, current_order, area, migratetype);
1068 set_freepage_migratetype(page, migratetype);
1077 * This array describes the order lists are fallen back to when
1078 * the free lists for the desirable migrate type are depleted
1080 static int fallbacks[MIGRATE_TYPES][4] = {
1081 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
1082 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
1083 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
1085 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
1087 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
1088 #ifdef CONFIG_MEMORY_ISOLATION
1089 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
1094 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1097 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1100 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1101 unsigned int order) { return NULL; }
1105 * Move the free pages in a range to the free lists of the requested type.
1106 * Note that start_page and end_pages are not aligned on a pageblock
1107 * boundary. If alignment is required, use move_freepages_block()
1109 int move_freepages(struct zone *zone,
1110 struct page *start_page, struct page *end_page,
1114 unsigned long order;
1115 int pages_moved = 0;
1117 #ifndef CONFIG_HOLES_IN_ZONE
1119 * page_zone is not safe to call in this context when
1120 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1121 * anyway as we check zone boundaries in move_freepages_block().
1122 * Remove at a later date when no bug reports exist related to
1123 * grouping pages by mobility
1125 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1128 for (page = start_page; page <= end_page;) {
1129 /* Make sure we are not inadvertently changing nodes */
1130 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1132 if (!pfn_valid_within(page_to_pfn(page))) {
1137 if (!PageBuddy(page)) {
1142 order = page_order(page);
1143 list_move(&page->lru,
1144 &zone->free_area[order].free_list[migratetype]);
1145 set_freepage_migratetype(page, migratetype);
1147 pages_moved += 1 << order;
1153 int move_freepages_block(struct zone *zone, struct page *page,
1156 unsigned long start_pfn, end_pfn;
1157 struct page *start_page, *end_page;
1159 start_pfn = page_to_pfn(page);
1160 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1161 start_page = pfn_to_page(start_pfn);
1162 end_page = start_page + pageblock_nr_pages - 1;
1163 end_pfn = start_pfn + pageblock_nr_pages - 1;
1165 /* Do not cross zone boundaries */
1166 if (!zone_spans_pfn(zone, start_pfn))
1168 if (!zone_spans_pfn(zone, end_pfn))
1171 return move_freepages(zone, start_page, end_page, migratetype);
1174 static void change_pageblock_range(struct page *pageblock_page,
1175 int start_order, int migratetype)
1177 int nr_pageblocks = 1 << (start_order - pageblock_order);
1179 while (nr_pageblocks--) {
1180 set_pageblock_migratetype(pageblock_page, migratetype);
1181 pageblock_page += pageblock_nr_pages;
1186 * When we are falling back to another migratetype during allocation, try to
1187 * steal extra free pages from the same pageblocks to satisfy further
1188 * allocations, instead of polluting multiple pageblocks.
1190 * If we are stealing a relatively large buddy page, it is likely there will
1191 * be more free pages in the pageblock, so try to steal them all. For
1192 * reclaimable and unmovable allocations, we steal regardless of page size,
1193 * as fragmentation caused by those allocations polluting movable pageblocks
1194 * is worse than movable allocations stealing from unmovable and reclaimable
1197 static bool can_steal_fallback(unsigned int order, int start_mt)
1200 * Leaving this order check is intended, although there is
1201 * relaxed order check in next check. The reason is that
1202 * we can actually steal whole pageblock if this condition met,
1203 * but, below check doesn't guarantee it and that is just heuristic
1204 * so could be changed anytime.
1206 if (order >= pageblock_order)
1209 if (order >= pageblock_order / 2 ||
1210 start_mt == MIGRATE_RECLAIMABLE ||
1211 start_mt == MIGRATE_UNMOVABLE ||
1212 page_group_by_mobility_disabled)
1219 * This function implements actual steal behaviour. If order is large enough,
1220 * we can steal whole pageblock. If not, we first move freepages in this
1221 * pageblock and check whether half of pages are moved or not. If half of
1222 * pages are moved, we can change migratetype of pageblock and permanently
1223 * use it's pages as requested migratetype in the future.
1225 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1228 int current_order = page_order(page);
1231 /* Take ownership for orders >= pageblock_order */
1232 if (current_order >= pageblock_order) {
1233 change_pageblock_range(page, current_order, start_type);
1237 pages = move_freepages_block(zone, page, start_type);
1239 /* Claim the whole block if over half of it is free */
1240 if (pages >= (1 << (pageblock_order-1)) ||
1241 page_group_by_mobility_disabled)
1242 set_pageblock_migratetype(page, start_type);
1246 * Check whether there is a suitable fallback freepage with requested order.
1247 * If only_stealable is true, this function returns fallback_mt only if
1248 * we can steal other freepages all together. This would help to reduce
1249 * fragmentation due to mixed migratetype pages in one pageblock.
1251 int find_suitable_fallback(struct free_area *area, unsigned int order,
1252 int migratetype, bool only_stealable, bool *can_steal)
1257 if (area->nr_free == 0)
1262 fallback_mt = fallbacks[migratetype][i];
1263 if (fallback_mt == MIGRATE_RESERVE)
1266 if (list_empty(&area->free_list[fallback_mt]))
1269 if (can_steal_fallback(order, migratetype))
1272 if (!only_stealable)
1282 /* Remove an element from the buddy allocator from the fallback list */
1283 static inline struct page *
1284 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
1286 struct free_area *area;
1287 unsigned int current_order;
1292 /* Find the largest possible block of pages in the other list */
1293 for (current_order = MAX_ORDER-1;
1294 current_order >= order && current_order <= MAX_ORDER-1;
1296 area = &(zone->free_area[current_order]);
1297 fallback_mt = find_suitable_fallback(area, current_order,
1298 start_migratetype, false, &can_steal);
1299 if (fallback_mt == -1)
1302 page = list_entry(area->free_list[fallback_mt].next,
1305 steal_suitable_fallback(zone, page, start_migratetype);
1307 /* Remove the page from the freelists */
1309 list_del(&page->lru);
1310 rmv_page_order(page);
1312 expand(zone, page, order, current_order, area,
1315 * The freepage_migratetype may differ from pageblock's
1316 * migratetype depending on the decisions in
1317 * try_to_steal_freepages(). This is OK as long as it
1318 * does not differ for MIGRATE_CMA pageblocks. For CMA
1319 * we need to make sure unallocated pages flushed from
1320 * pcp lists are returned to the correct freelist.
1322 set_freepage_migratetype(page, start_migratetype);
1324 trace_mm_page_alloc_extfrag(page, order, current_order,
1325 start_migratetype, fallback_mt);
1334 * Do the hard work of removing an element from the buddy allocator.
1335 * Call me with the zone->lock already held.
1337 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1343 page = __rmqueue_smallest(zone, order, migratetype);
1345 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1346 if (migratetype == MIGRATE_MOVABLE)
1347 page = __rmqueue_cma_fallback(zone, order);
1350 page = __rmqueue_fallback(zone, order, migratetype);
1353 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1354 * is used because __rmqueue_smallest is an inline function
1355 * and we want just one call site
1358 migratetype = MIGRATE_RESERVE;
1363 trace_mm_page_alloc_zone_locked(page, order, migratetype);
1368 * Obtain a specified number of elements from the buddy allocator, all under
1369 * a single hold of the lock, for efficiency. Add them to the supplied list.
1370 * Returns the number of new pages which were placed at *list.
1372 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1373 unsigned long count, struct list_head *list,
1374 int migratetype, bool cold)
1378 spin_lock(&zone->lock);
1379 for (i = 0; i < count; ++i) {
1380 struct page *page = __rmqueue(zone, order, migratetype);
1381 if (unlikely(page == NULL))
1385 * Split buddy pages returned by expand() are received here
1386 * in physical page order. The page is added to the callers and
1387 * list and the list head then moves forward. From the callers
1388 * perspective, the linked list is ordered by page number in
1389 * some conditions. This is useful for IO devices that can
1390 * merge IO requests if the physical pages are ordered
1394 list_add(&page->lru, list);
1396 list_add_tail(&page->lru, list);
1398 if (is_migrate_cma(get_freepage_migratetype(page)))
1399 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1402 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1403 spin_unlock(&zone->lock);
1409 * Called from the vmstat counter updater to drain pagesets of this
1410 * currently executing processor on remote nodes after they have
1413 * Note that this function must be called with the thread pinned to
1414 * a single processor.
1416 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1418 unsigned long flags;
1419 int to_drain, batch;
1421 local_irq_save(flags);
1422 batch = READ_ONCE(pcp->batch);
1423 to_drain = min(pcp->count, batch);
1425 free_pcppages_bulk(zone, to_drain, pcp);
1426 pcp->count -= to_drain;
1428 local_irq_restore(flags);
1433 * Drain pcplists of the indicated processor and zone.
1435 * The processor must either be the current processor and the
1436 * thread pinned to the current processor or a processor that
1439 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
1441 unsigned long flags;
1442 struct per_cpu_pageset *pset;
1443 struct per_cpu_pages *pcp;
1445 local_irq_save(flags);
1446 pset = per_cpu_ptr(zone->pageset, cpu);
1450 free_pcppages_bulk(zone, pcp->count, pcp);
1453 local_irq_restore(flags);
1457 * Drain pcplists of all zones on the indicated processor.
1459 * The processor must either be the current processor and the
1460 * thread pinned to the current processor or a processor that
1463 static void drain_pages(unsigned int cpu)
1467 for_each_populated_zone(zone) {
1468 drain_pages_zone(cpu, zone);
1473 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1475 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1476 * the single zone's pages.
1478 void drain_local_pages(struct zone *zone)
1480 int cpu = smp_processor_id();
1483 drain_pages_zone(cpu, zone);
1489 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1491 * When zone parameter is non-NULL, spill just the single zone's pages.
1493 * Note that this code is protected against sending an IPI to an offline
1494 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1495 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1496 * nothing keeps CPUs from showing up after we populated the cpumask and
1497 * before the call to on_each_cpu_mask().
1499 void drain_all_pages(struct zone *zone)
1504 * Allocate in the BSS so we wont require allocation in
1505 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1507 static cpumask_t cpus_with_pcps;
1510 * We don't care about racing with CPU hotplug event
1511 * as offline notification will cause the notified
1512 * cpu to drain that CPU pcps and on_each_cpu_mask
1513 * disables preemption as part of its processing
1515 for_each_online_cpu(cpu) {
1516 struct per_cpu_pageset *pcp;
1518 bool has_pcps = false;
1521 pcp = per_cpu_ptr(zone->pageset, cpu);
1525 for_each_populated_zone(z) {
1526 pcp = per_cpu_ptr(z->pageset, cpu);
1527 if (pcp->pcp.count) {
1535 cpumask_set_cpu(cpu, &cpus_with_pcps);
1537 cpumask_clear_cpu(cpu, &cpus_with_pcps);
1539 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
1543 #ifdef CONFIG_HIBERNATION
1545 void mark_free_pages(struct zone *zone)
1547 unsigned long pfn, max_zone_pfn;
1548 unsigned long flags;
1549 unsigned int order, t;
1550 struct list_head *curr;
1552 if (zone_is_empty(zone))
1555 spin_lock_irqsave(&zone->lock, flags);
1557 max_zone_pfn = zone_end_pfn(zone);
1558 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1559 if (pfn_valid(pfn)) {
1560 struct page *page = pfn_to_page(pfn);
1562 if (!swsusp_page_is_forbidden(page))
1563 swsusp_unset_page_free(page);
1566 for_each_migratetype_order(order, t) {
1567 list_for_each(curr, &zone->free_area[order].free_list[t]) {
1570 pfn = page_to_pfn(list_entry(curr, struct page, lru));
1571 for (i = 0; i < (1UL << order); i++)
1572 swsusp_set_page_free(pfn_to_page(pfn + i));
1575 spin_unlock_irqrestore(&zone->lock, flags);
1577 #endif /* CONFIG_PM */
1580 * Free a 0-order page
1581 * cold == true ? free a cold page : free a hot page
1583 void free_hot_cold_page(struct page *page, bool cold)
1585 struct zone *zone = page_zone(page);
1586 struct per_cpu_pages *pcp;
1587 unsigned long flags;
1588 unsigned long pfn = page_to_pfn(page);
1591 if (!free_pages_prepare(page, 0))
1594 migratetype = get_pfnblock_migratetype(page, pfn);
1595 set_freepage_migratetype(page, migratetype);
1596 local_irq_save(flags);
1597 __count_vm_event(PGFREE);
1600 * We only track unmovable, reclaimable and movable on pcp lists.
1601 * Free ISOLATE pages back to the allocator because they are being
1602 * offlined but treat RESERVE as movable pages so we can get those
1603 * areas back if necessary. Otherwise, we may have to free
1604 * excessively into the page allocator
1606 if (migratetype >= MIGRATE_PCPTYPES) {
1607 if (unlikely(is_migrate_isolate(migratetype))) {
1608 free_one_page(zone, page, pfn, 0, migratetype);
1611 migratetype = MIGRATE_MOVABLE;
1614 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1616 list_add(&page->lru, &pcp->lists[migratetype]);
1618 list_add_tail(&page->lru, &pcp->lists[migratetype]);
1620 if (pcp->count >= pcp->high) {
1621 unsigned long batch = READ_ONCE(pcp->batch);
1622 free_pcppages_bulk(zone, batch, pcp);
1623 pcp->count -= batch;
1627 local_irq_restore(flags);
1631 * Free a list of 0-order pages
1633 void free_hot_cold_page_list(struct list_head *list, bool cold)
1635 struct page *page, *next;
1637 list_for_each_entry_safe(page, next, list, lru) {
1638 trace_mm_page_free_batched(page, cold);
1639 free_hot_cold_page(page, cold);
1644 * split_page takes a non-compound higher-order page, and splits it into
1645 * n (1<<order) sub-pages: page[0..n]
1646 * Each sub-page must be freed individually.
1648 * Note: this is probably too low level an operation for use in drivers.
1649 * Please consult with lkml before using this in your driver.
1651 void split_page(struct page *page, unsigned int order)
1655 VM_BUG_ON_PAGE(PageCompound(page), page);
1656 VM_BUG_ON_PAGE(!page_count(page), page);
1658 #ifdef CONFIG_KMEMCHECK
1660 * Split shadow pages too, because free(page[0]) would
1661 * otherwise free the whole shadow.
1663 if (kmemcheck_page_is_tracked(page))
1664 split_page(virt_to_page(page[0].shadow), order);
1667 set_page_owner(page, 0, 0);
1668 for (i = 1; i < (1 << order); i++) {
1669 set_page_refcounted(page + i);
1670 set_page_owner(page + i, 0, 0);
1673 EXPORT_SYMBOL_GPL(split_page);
1675 int __isolate_free_page(struct page *page, unsigned int order)
1677 unsigned long watermark;
1681 BUG_ON(!PageBuddy(page));
1683 zone = page_zone(page);
1684 mt = get_pageblock_migratetype(page);
1686 if (!is_migrate_isolate(mt)) {
1687 /* Obey watermarks as if the page was being allocated */
1688 watermark = low_wmark_pages(zone) + (1 << order);
1689 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1692 __mod_zone_freepage_state(zone, -(1UL << order), mt);
1695 /* Remove page from free list */
1696 list_del(&page->lru);
1697 zone->free_area[order].nr_free--;
1698 rmv_page_order(page);
1700 /* Set the pageblock if the isolated page is at least a pageblock */
1701 if (order >= pageblock_order - 1) {
1702 struct page *endpage = page + (1 << order) - 1;
1703 for (; page < endpage; page += pageblock_nr_pages) {
1704 int mt = get_pageblock_migratetype(page);
1705 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
1706 set_pageblock_migratetype(page,
1711 set_page_owner(page, order, 0);
1712 return 1UL << order;
1716 * Similar to split_page except the page is already free. As this is only
1717 * being used for migration, the migratetype of the block also changes.
1718 * As this is called with interrupts disabled, the caller is responsible
1719 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1722 * Note: this is probably too low level an operation for use in drivers.
1723 * Please consult with lkml before using this in your driver.
1725 int split_free_page(struct page *page)
1730 order = page_order(page);
1732 nr_pages = __isolate_free_page(page, order);
1736 /* Split into individual pages */
1737 set_page_refcounted(page);
1738 split_page(page, order);
1743 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
1746 struct page *buffered_rmqueue(struct zone *preferred_zone,
1747 struct zone *zone, unsigned int order,
1748 gfp_t gfp_flags, int migratetype)
1750 unsigned long flags;
1752 bool cold = ((gfp_flags & __GFP_COLD) != 0);
1754 if (likely(order == 0)) {
1755 struct per_cpu_pages *pcp;
1756 struct list_head *list;
1758 local_irq_save(flags);
1759 pcp = &this_cpu_ptr(zone->pageset)->pcp;
1760 list = &pcp->lists[migratetype];
1761 if (list_empty(list)) {
1762 pcp->count += rmqueue_bulk(zone, 0,
1765 if (unlikely(list_empty(list)))
1770 page = list_entry(list->prev, struct page, lru);
1772 page = list_entry(list->next, struct page, lru);
1774 list_del(&page->lru);
1777 if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1779 * __GFP_NOFAIL is not to be used in new code.
1781 * All __GFP_NOFAIL callers should be fixed so that they
1782 * properly detect and handle allocation failures.
1784 * We most definitely don't want callers attempting to
1785 * allocate greater than order-1 page units with
1788 WARN_ON_ONCE(order > 1);
1790 spin_lock_irqsave(&zone->lock, flags);
1791 page = __rmqueue(zone, order, migratetype);
1792 spin_unlock(&zone->lock);
1795 __mod_zone_freepage_state(zone, -(1 << order),
1796 get_freepage_migratetype(page));
1799 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
1800 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
1801 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
1802 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
1804 __count_zone_vm_events(PGALLOC, zone, 1 << order);
1805 zone_statistics(preferred_zone, zone, gfp_flags);
1806 local_irq_restore(flags);
1808 VM_BUG_ON_PAGE(bad_range(zone, page), page);
1812 local_irq_restore(flags);
1816 #ifdef CONFIG_FAIL_PAGE_ALLOC
1819 struct fault_attr attr;
1821 u32 ignore_gfp_highmem;
1822 u32 ignore_gfp_wait;
1824 } fail_page_alloc = {
1825 .attr = FAULT_ATTR_INITIALIZER,
1826 .ignore_gfp_wait = 1,
1827 .ignore_gfp_highmem = 1,
1831 static int __init setup_fail_page_alloc(char *str)
1833 return setup_fault_attr(&fail_page_alloc.attr, str);
1835 __setup("fail_page_alloc=", setup_fail_page_alloc);
1837 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1839 if (order < fail_page_alloc.min_order)
1841 if (gfp_mask & __GFP_NOFAIL)
1843 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1845 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1848 return should_fail(&fail_page_alloc.attr, 1 << order);
1851 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1853 static int __init fail_page_alloc_debugfs(void)
1855 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1858 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1859 &fail_page_alloc.attr);
1861 return PTR_ERR(dir);
1863 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1864 &fail_page_alloc.ignore_gfp_wait))
1866 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1867 &fail_page_alloc.ignore_gfp_highmem))
1869 if (!debugfs_create_u32("min-order", mode, dir,
1870 &fail_page_alloc.min_order))
1875 debugfs_remove_recursive(dir);
1880 late_initcall(fail_page_alloc_debugfs);
1882 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1884 #else /* CONFIG_FAIL_PAGE_ALLOC */
1886 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1891 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1894 * Return true if free pages are above 'mark'. This takes into account the order
1895 * of the allocation.
1897 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
1898 unsigned long mark, int classzone_idx, int alloc_flags,
1901 /* free_pages may go negative - that's OK */
1906 free_pages -= (1 << order) - 1;
1907 if (alloc_flags & ALLOC_HIGH)
1909 if (alloc_flags & ALLOC_HARDER)
1912 /* If allocation can't use CMA areas don't use free CMA pages */
1913 if (!(alloc_flags & ALLOC_CMA))
1914 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
1917 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
1919 for (o = 0; o < order; o++) {
1920 /* At the next order, this order's pages become unavailable */
1921 free_pages -= z->free_area[o].nr_free << o;
1923 /* Require fewer higher order pages to be free */
1926 if (free_pages <= min)
1932 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1933 int classzone_idx, int alloc_flags)
1935 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1936 zone_page_state(z, NR_FREE_PAGES));
1939 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1940 unsigned long mark, int classzone_idx, int alloc_flags)
1942 long free_pages = zone_page_state(z, NR_FREE_PAGES);
1944 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1945 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1947 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1953 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1954 * skip over zones that are not allowed by the cpuset, or that have
1955 * been recently (in last second) found to be nearly full. See further
1956 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1957 * that have to skip over a lot of full or unallowed zones.
1959 * If the zonelist cache is present in the passed zonelist, then
1960 * returns a pointer to the allowed node mask (either the current
1961 * tasks mems_allowed, or node_states[N_MEMORY].)
1963 * If the zonelist cache is not available for this zonelist, does
1964 * nothing and returns NULL.
1966 * If the fullzones BITMAP in the zonelist cache is stale (more than
1967 * a second since last zap'd) then we zap it out (clear its bits.)
1969 * We hold off even calling zlc_setup, until after we've checked the
1970 * first zone in the zonelist, on the theory that most allocations will
1971 * be satisfied from that first zone, so best to examine that zone as
1972 * quickly as we can.
1974 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1976 struct zonelist_cache *zlc; /* cached zonelist speedup info */
1977 nodemask_t *allowednodes; /* zonelist_cache approximation */
1979 zlc = zonelist->zlcache_ptr;
1983 if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1984 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1985 zlc->last_full_zap = jiffies;
1988 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1989 &cpuset_current_mems_allowed :
1990 &node_states[N_MEMORY];
1991 return allowednodes;
1995 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1996 * if it is worth looking at further for free memory:
1997 * 1) Check that the zone isn't thought to be full (doesn't have its
1998 * bit set in the zonelist_cache fullzones BITMAP).
1999 * 2) Check that the zones node (obtained from the zonelist_cache
2000 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
2001 * Return true (non-zero) if zone is worth looking at further, or
2002 * else return false (zero) if it is not.
2004 * This check -ignores- the distinction between various watermarks,
2005 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
2006 * found to be full for any variation of these watermarks, it will
2007 * be considered full for up to one second by all requests, unless
2008 * we are so low on memory on all allowed nodes that we are forced
2009 * into the second scan of the zonelist.
2011 * In the second scan we ignore this zonelist cache and exactly
2012 * apply the watermarks to all zones, even it is slower to do so.
2013 * We are low on memory in the second scan, and should leave no stone
2014 * unturned looking for a free page.
2016 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
2017 nodemask_t *allowednodes)
2019 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2020 int i; /* index of *z in zonelist zones */
2021 int n; /* node that zone *z is on */
2023 zlc = zonelist->zlcache_ptr;
2027 i = z - zonelist->_zonerefs;
2030 /* This zone is worth trying if it is allowed but not full */
2031 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
2035 * Given 'z' scanning a zonelist, set the corresponding bit in
2036 * zlc->fullzones, so that subsequent attempts to allocate a page
2037 * from that zone don't waste time re-examining it.
2039 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
2041 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2042 int i; /* index of *z in zonelist zones */
2044 zlc = zonelist->zlcache_ptr;
2048 i = z - zonelist->_zonerefs;
2050 set_bit(i, zlc->fullzones);
2054 * clear all zones full, called after direct reclaim makes progress so that
2055 * a zone that was recently full is not skipped over for up to a second
2057 static void zlc_clear_zones_full(struct zonelist *zonelist)
2059 struct zonelist_cache *zlc; /* cached zonelist speedup info */
2061 zlc = zonelist->zlcache_ptr;
2065 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2068 static bool zone_local(struct zone *local_zone, struct zone *zone)
2070 return local_zone->node == zone->node;
2073 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2075 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2079 #else /* CONFIG_NUMA */
2081 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
2086 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
2087 nodemask_t *allowednodes)
2092 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
2096 static void zlc_clear_zones_full(struct zonelist *zonelist)
2100 static bool zone_local(struct zone *local_zone, struct zone *zone)
2105 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2110 #endif /* CONFIG_NUMA */
2112 static void reset_alloc_batches(struct zone *preferred_zone)
2114 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2117 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2118 high_wmark_pages(zone) - low_wmark_pages(zone) -
2119 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2120 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2121 } while (zone++ != preferred_zone);
2125 * get_page_from_freelist goes through the zonelist trying to allocate
2128 static struct page *
2129 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2130 const struct alloc_context *ac)
2132 struct zonelist *zonelist = ac->zonelist;
2134 struct page *page = NULL;
2136 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
2137 int zlc_active = 0; /* set if using zonelist_cache */
2138 int did_zlc_setup = 0; /* just call zlc_setup() one time */
2139 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
2140 (gfp_mask & __GFP_WRITE);
2141 int nr_fair_skipped = 0;
2142 bool zonelist_rescan;
2145 zonelist_rescan = false;
2148 * Scan zonelist, looking for a zone with enough free.
2149 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2151 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2155 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2156 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2158 if (cpusets_enabled() &&
2159 (alloc_flags & ALLOC_CPUSET) &&
2160 !cpuset_zone_allowed(zone, gfp_mask))
2163 * Distribute pages in proportion to the individual
2164 * zone size to ensure fair page aging. The zone a
2165 * page was allocated in should have no effect on the
2166 * time the page has in memory before being reclaimed.
2168 if (alloc_flags & ALLOC_FAIR) {
2169 if (!zone_local(ac->preferred_zone, zone))
2171 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2177 * When allocating a page cache page for writing, we
2178 * want to get it from a zone that is within its dirty
2179 * limit, such that no single zone holds more than its
2180 * proportional share of globally allowed dirty pages.
2181 * The dirty limits take into account the zone's
2182 * lowmem reserves and high watermark so that kswapd
2183 * should be able to balance it without having to
2184 * write pages from its LRU list.
2186 * This may look like it could increase pressure on
2187 * lower zones by failing allocations in higher zones
2188 * before they are full. But the pages that do spill
2189 * over are limited as the lower zones are protected
2190 * by this very same mechanism. It should not become
2191 * a practical burden to them.
2193 * XXX: For now, allow allocations to potentially
2194 * exceed the per-zone dirty limit in the slowpath
2195 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2196 * which is important when on a NUMA setup the allowed
2197 * zones are together not big enough to reach the
2198 * global limit. The proper fix for these situations
2199 * will require awareness of zones in the
2200 * dirty-throttling and the flusher threads.
2202 if (consider_zone_dirty && !zone_dirty_ok(zone))
2205 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2206 if (!zone_watermark_ok(zone, order, mark,
2207 ac->classzone_idx, alloc_flags)) {
2210 /* Checked here to keep the fast path fast */
2211 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2212 if (alloc_flags & ALLOC_NO_WATERMARKS)
2215 if (IS_ENABLED(CONFIG_NUMA) &&
2216 !did_zlc_setup && nr_online_nodes > 1) {
2218 * we do zlc_setup if there are multiple nodes
2219 * and before considering the first zone allowed
2222 allowednodes = zlc_setup(zonelist, alloc_flags);
2227 if (zone_reclaim_mode == 0 ||
2228 !zone_allows_reclaim(ac->preferred_zone, zone))
2229 goto this_zone_full;
2232 * As we may have just activated ZLC, check if the first
2233 * eligible zone has failed zone_reclaim recently.
2235 if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
2236 !zlc_zone_worth_trying(zonelist, z, allowednodes))
2239 ret = zone_reclaim(zone, gfp_mask, order);
2241 case ZONE_RECLAIM_NOSCAN:
2244 case ZONE_RECLAIM_FULL:
2245 /* scanned but unreclaimable */
2248 /* did we reclaim enough */
2249 if (zone_watermark_ok(zone, order, mark,
2250 ac->classzone_idx, alloc_flags))
2254 * Failed to reclaim enough to meet watermark.
2255 * Only mark the zone full if checking the min
2256 * watermark or if we failed to reclaim just
2257 * 1<<order pages or else the page allocator
2258 * fastpath will prematurely mark zones full
2259 * when the watermark is between the low and
2262 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
2263 ret == ZONE_RECLAIM_SOME)
2264 goto this_zone_full;
2271 page = buffered_rmqueue(ac->preferred_zone, zone, order,
2272 gfp_mask, ac->migratetype);
2274 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2279 if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
2280 zlc_mark_zone_full(zonelist, z);
2284 * The first pass makes sure allocations are spread fairly within the
2285 * local node. However, the local node might have free pages left
2286 * after the fairness batches are exhausted, and remote zones haven't
2287 * even been considered yet. Try once more without fairness, and
2288 * include remote zones now, before entering the slowpath and waking
2289 * kswapd: prefer spilling to a remote zone over swapping locally.
2291 if (alloc_flags & ALLOC_FAIR) {
2292 alloc_flags &= ~ALLOC_FAIR;
2293 if (nr_fair_skipped) {
2294 zonelist_rescan = true;
2295 reset_alloc_batches(ac->preferred_zone);
2297 if (nr_online_nodes > 1)
2298 zonelist_rescan = true;
2301 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) {
2302 /* Disable zlc cache for second zonelist scan */
2304 zonelist_rescan = true;
2307 if (zonelist_rescan)
2314 * Large machines with many possible nodes should not always dump per-node
2315 * meminfo in irq context.
2317 static inline bool should_suppress_show_mem(void)
2322 ret = in_interrupt();
2327 static DEFINE_RATELIMIT_STATE(nopage_rs,
2328 DEFAULT_RATELIMIT_INTERVAL,
2329 DEFAULT_RATELIMIT_BURST);
2331 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2333 unsigned int filter = SHOW_MEM_FILTER_NODES;
2335 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2336 debug_guardpage_minorder() > 0)
2340 * This documents exceptions given to allocations in certain
2341 * contexts that are allowed to allocate outside current's set
2344 if (!(gfp_mask & __GFP_NOMEMALLOC))
2345 if (test_thread_flag(TIF_MEMDIE) ||
2346 (current->flags & (PF_MEMALLOC | PF_EXITING)))
2347 filter &= ~SHOW_MEM_FILTER_NODES;
2348 if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2349 filter &= ~SHOW_MEM_FILTER_NODES;
2352 struct va_format vaf;
2355 va_start(args, fmt);
2360 pr_warn("%pV", &vaf);
2365 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2366 current->comm, order, gfp_mask);
2369 if (!should_suppress_show_mem())
2373 static inline struct page *
2374 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2375 const struct alloc_context *ac, unsigned long *did_some_progress)
2379 *did_some_progress = 0;
2382 * Acquire the oom lock. If that fails, somebody else is
2383 * making progress for us.
2385 if (!mutex_trylock(&oom_lock)) {
2386 *did_some_progress = 1;
2387 schedule_timeout_uninterruptible(1);
2392 * Go through the zonelist yet one more time, keep very high watermark
2393 * here, this is only to catch a parallel oom killing, we must fail if
2394 * we're still under heavy pressure.
2396 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
2397 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
2401 if (!(gfp_mask & __GFP_NOFAIL)) {
2402 /* Coredumps can quickly deplete all memory reserves */
2403 if (current->flags & PF_DUMPCORE)
2405 /* The OOM killer will not help higher order allocs */
2406 if (order > PAGE_ALLOC_COSTLY_ORDER)
2408 /* The OOM killer does not needlessly kill tasks for lowmem */
2409 if (ac->high_zoneidx < ZONE_NORMAL)
2411 /* The OOM killer does not compensate for IO-less reclaim */
2412 if (!(gfp_mask & __GFP_FS)) {
2414 * XXX: Page reclaim didn't yield anything,
2415 * and the OOM killer can't be invoked, but
2416 * keep looping as per tradition.
2418 *did_some_progress = 1;
2421 if (pm_suspended_storage())
2423 /* The OOM killer may not free memory on a specific node */
2424 if (gfp_mask & __GFP_THISNODE)
2427 /* Exhausted what can be done so it's blamo time */
2428 if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false)
2429 || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
2430 *did_some_progress = 1;
2432 mutex_unlock(&oom_lock);
2436 #ifdef CONFIG_COMPACTION
2437 /* Try memory compaction for high-order allocations before reclaim */
2438 static struct page *
2439 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2440 int alloc_flags, const struct alloc_context *ac,
2441 enum migrate_mode mode, int *contended_compaction,
2442 bool *deferred_compaction)
2444 unsigned long compact_result;
2450 current->flags |= PF_MEMALLOC;
2451 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
2452 mode, contended_compaction);
2453 current->flags &= ~PF_MEMALLOC;
2455 switch (compact_result) {
2456 case COMPACT_DEFERRED:
2457 *deferred_compaction = true;
2459 case COMPACT_SKIPPED:
2466 * At least in one zone compaction wasn't deferred or skipped, so let's
2467 * count a compaction stall
2469 count_vm_event(COMPACTSTALL);
2471 page = get_page_from_freelist(gfp_mask, order,
2472 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2475 struct zone *zone = page_zone(page);
2477 zone->compact_blockskip_flush = false;
2478 compaction_defer_reset(zone, order, true);
2479 count_vm_event(COMPACTSUCCESS);
2484 * It's bad if compaction run occurs and fails. The most likely reason
2485 * is that pages exist, but not enough to satisfy watermarks.
2487 count_vm_event(COMPACTFAIL);
2494 static inline struct page *
2495 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2496 int alloc_flags, const struct alloc_context *ac,
2497 enum migrate_mode mode, int *contended_compaction,
2498 bool *deferred_compaction)
2502 #endif /* CONFIG_COMPACTION */
2504 /* Perform direct synchronous page reclaim */
2506 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
2507 const struct alloc_context *ac)
2509 struct reclaim_state reclaim_state;
2514 /* We now go into synchronous reclaim */
2515 cpuset_memory_pressure_bump();
2516 current->flags |= PF_MEMALLOC;
2517 lockdep_set_current_reclaim_state(gfp_mask);
2518 reclaim_state.reclaimed_slab = 0;
2519 current->reclaim_state = &reclaim_state;
2521 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
2524 current->reclaim_state = NULL;
2525 lockdep_clear_current_reclaim_state();
2526 current->flags &= ~PF_MEMALLOC;
2533 /* The really slow allocator path where we enter direct reclaim */
2534 static inline struct page *
2535 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2536 int alloc_flags, const struct alloc_context *ac,
2537 unsigned long *did_some_progress)
2539 struct page *page = NULL;
2540 bool drained = false;
2542 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
2543 if (unlikely(!(*did_some_progress)))
2546 /* After successful reclaim, reconsider all zones for allocation */
2547 if (IS_ENABLED(CONFIG_NUMA))
2548 zlc_clear_zones_full(ac->zonelist);
2551 page = get_page_from_freelist(gfp_mask, order,
2552 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2555 * If an allocation failed after direct reclaim, it could be because
2556 * pages are pinned on the per-cpu lists. Drain them and try again
2558 if (!page && !drained) {
2559 drain_all_pages(NULL);
2568 * This is called in the allocator slow-path if the allocation request is of
2569 * sufficient urgency to ignore watermarks and take other desperate measures
2571 static inline struct page *
2572 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2573 const struct alloc_context *ac)
2578 page = get_page_from_freelist(gfp_mask, order,
2579 ALLOC_NO_WATERMARKS, ac);
2581 if (!page && gfp_mask & __GFP_NOFAIL)
2582 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC,
2584 } while (!page && (gfp_mask & __GFP_NOFAIL));
2589 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
2594 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
2595 ac->high_zoneidx, ac->nodemask)
2596 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
2600 gfp_to_alloc_flags(gfp_t gfp_mask)
2602 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2603 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
2605 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2606 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2609 * The caller may dip into page reserves a bit more if the caller
2610 * cannot run direct reclaim, or if the caller has realtime scheduling
2611 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2612 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2614 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2618 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2619 * if it can't schedule.
2621 if (!(gfp_mask & __GFP_NOMEMALLOC))
2622 alloc_flags |= ALLOC_HARDER;
2624 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2625 * comment for __cpuset_node_allowed().
2627 alloc_flags &= ~ALLOC_CPUSET;
2628 } else if (unlikely(rt_task(current)) && !in_interrupt())
2629 alloc_flags |= ALLOC_HARDER;
2631 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2632 if (gfp_mask & __GFP_MEMALLOC)
2633 alloc_flags |= ALLOC_NO_WATERMARKS;
2634 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2635 alloc_flags |= ALLOC_NO_WATERMARKS;
2636 else if (!in_interrupt() &&
2637 ((current->flags & PF_MEMALLOC) ||
2638 unlikely(test_thread_flag(TIF_MEMDIE))))
2639 alloc_flags |= ALLOC_NO_WATERMARKS;
2642 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2643 alloc_flags |= ALLOC_CMA;
2648 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
2650 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2653 static inline struct page *
2654 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2655 struct alloc_context *ac)
2657 const gfp_t wait = gfp_mask & __GFP_WAIT;
2658 struct page *page = NULL;
2660 unsigned long pages_reclaimed = 0;
2661 unsigned long did_some_progress;
2662 enum migrate_mode migration_mode = MIGRATE_ASYNC;
2663 bool deferred_compaction = false;
2664 int contended_compaction = COMPACT_CONTENDED_NONE;
2667 * In the slowpath, we sanity check order to avoid ever trying to
2668 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2669 * be using allocators in order of preference for an area that is
2672 if (order >= MAX_ORDER) {
2673 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2678 * If this allocation cannot block and it is for a specific node, then
2679 * fail early. There's no need to wakeup kswapd or retry for a
2680 * speculative node-specific allocation.
2682 if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait)
2686 if (!(gfp_mask & __GFP_NO_KSWAPD))
2687 wake_all_kswapds(order, ac);
2690 * OK, we're below the kswapd watermark and have kicked background
2691 * reclaim. Now things get more complex, so set up alloc_flags according
2692 * to how we want to proceed.
2694 alloc_flags = gfp_to_alloc_flags(gfp_mask);
2697 * Find the true preferred zone if the allocation is unconstrained by
2700 if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) {
2701 struct zoneref *preferred_zoneref;
2702 preferred_zoneref = first_zones_zonelist(ac->zonelist,
2703 ac->high_zoneidx, NULL, &ac->preferred_zone);
2704 ac->classzone_idx = zonelist_zone_idx(preferred_zoneref);
2707 /* This is the last chance, in general, before the goto nopage. */
2708 page = get_page_from_freelist(gfp_mask, order,
2709 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
2713 /* Allocate without watermarks if the context allows */
2714 if (alloc_flags & ALLOC_NO_WATERMARKS) {
2716 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2717 * the allocation is high priority and these type of
2718 * allocations are system rather than user orientated
2720 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
2722 page = __alloc_pages_high_priority(gfp_mask, order, ac);
2729 /* Atomic allocations - we can't balance anything */
2732 * All existing users of the deprecated __GFP_NOFAIL are
2733 * blockable, so warn of any new users that actually allow this
2734 * type of allocation to fail.
2736 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
2740 /* Avoid recursion of direct reclaim */
2741 if (current->flags & PF_MEMALLOC)
2744 /* Avoid allocations with no watermarks from looping endlessly */
2745 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2749 * Try direct compaction. The first pass is asynchronous. Subsequent
2750 * attempts after direct reclaim are synchronous
2752 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
2754 &contended_compaction,
2755 &deferred_compaction);
2759 /* Checks for THP-specific high-order allocations */
2760 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) {
2762 * If compaction is deferred for high-order allocations, it is
2763 * because sync compaction recently failed. If this is the case
2764 * and the caller requested a THP allocation, we do not want
2765 * to heavily disrupt the system, so we fail the allocation
2766 * instead of entering direct reclaim.
2768 if (deferred_compaction)
2772 * In all zones where compaction was attempted (and not
2773 * deferred or skipped), lock contention has been detected.
2774 * For THP allocation we do not want to disrupt the others
2775 * so we fallback to base pages instead.
2777 if (contended_compaction == COMPACT_CONTENDED_LOCK)
2781 * If compaction was aborted due to need_resched(), we do not
2782 * want to further increase allocation latency, unless it is
2783 * khugepaged trying to collapse.
2785 if (contended_compaction == COMPACT_CONTENDED_SCHED
2786 && !(current->flags & PF_KTHREAD))
2791 * It can become very expensive to allocate transparent hugepages at
2792 * fault, so use asynchronous memory compaction for THP unless it is
2793 * khugepaged trying to collapse.
2795 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE ||
2796 (current->flags & PF_KTHREAD))
2797 migration_mode = MIGRATE_SYNC_LIGHT;
2799 /* Try direct reclaim and then allocating */
2800 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
2801 &did_some_progress);
2805 /* Do not loop if specifically requested */
2806 if (gfp_mask & __GFP_NORETRY)
2809 /* Keep reclaiming pages as long as there is reasonable progress */
2810 pages_reclaimed += did_some_progress;
2811 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
2812 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
2813 /* Wait for some write requests to complete then retry */
2814 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
2818 /* Reclaim has failed us, start killing things */
2819 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
2823 /* Retry as long as the OOM killer is making progress */
2824 if (did_some_progress)
2829 * High-order allocations do not necessarily loop after
2830 * direct reclaim and reclaim/compaction depends on compaction
2831 * being called after reclaim so call directly if necessary
2833 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
2835 &contended_compaction,
2836 &deferred_compaction);
2840 warn_alloc_failed(gfp_mask, order, NULL);
2846 * This is the 'heart' of the zoned buddy allocator.
2849 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2850 struct zonelist *zonelist, nodemask_t *nodemask)
2852 struct zoneref *preferred_zoneref;
2853 struct page *page = NULL;
2854 unsigned int cpuset_mems_cookie;
2855 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
2856 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
2857 struct alloc_context ac = {
2858 .high_zoneidx = gfp_zone(gfp_mask),
2859 .nodemask = nodemask,
2860 .migratetype = gfpflags_to_migratetype(gfp_mask),
2863 gfp_mask &= gfp_allowed_mask;
2865 lockdep_trace_alloc(gfp_mask);
2867 might_sleep_if(gfp_mask & __GFP_WAIT);
2869 if (should_fail_alloc_page(gfp_mask, order))
2873 * Check the zones suitable for the gfp_mask contain at least one
2874 * valid zone. It's possible to have an empty zonelist as a result
2875 * of __GFP_THISNODE and a memoryless node
2877 if (unlikely(!zonelist->_zonerefs->zone))
2880 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
2881 alloc_flags |= ALLOC_CMA;
2884 cpuset_mems_cookie = read_mems_allowed_begin();
2886 /* We set it here, as __alloc_pages_slowpath might have changed it */
2887 ac.zonelist = zonelist;
2888 /* The preferred zone is used for statistics later */
2889 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
2890 ac.nodemask ? : &cpuset_current_mems_allowed,
2891 &ac.preferred_zone);
2892 if (!ac.preferred_zone)
2894 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
2896 /* First allocation attempt */
2897 alloc_mask = gfp_mask|__GFP_HARDWALL;
2898 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
2899 if (unlikely(!page)) {
2901 * Runtime PM, block IO and its error handling path
2902 * can deadlock because I/O on the device might not
2905 alloc_mask = memalloc_noio_flags(gfp_mask);
2907 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
2910 if (kmemcheck_enabled && page)
2911 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2913 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
2917 * When updating a task's mems_allowed, it is possible to race with
2918 * parallel threads in such a way that an allocation can fail while
2919 * the mask is being updated. If a page allocation is about to fail,
2920 * check if the cpuset changed during allocation and if so, retry.
2922 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2927 EXPORT_SYMBOL(__alloc_pages_nodemask);
2930 * Common helper functions.
2932 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2937 * __get_free_pages() returns a 32-bit address, which cannot represent
2940 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2942 page = alloc_pages(gfp_mask, order);
2945 return (unsigned long) page_address(page);
2947 EXPORT_SYMBOL(__get_free_pages);
2949 unsigned long get_zeroed_page(gfp_t gfp_mask)
2951 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2953 EXPORT_SYMBOL(get_zeroed_page);
2955 void __free_pages(struct page *page, unsigned int order)
2957 if (put_page_testzero(page)) {
2959 free_hot_cold_page(page, false);
2961 __free_pages_ok(page, order);
2965 EXPORT_SYMBOL(__free_pages);
2967 void free_pages(unsigned long addr, unsigned int order)
2970 VM_BUG_ON(!virt_addr_valid((void *)addr));
2971 __free_pages(virt_to_page((void *)addr), order);
2975 EXPORT_SYMBOL(free_pages);
2979 * An arbitrary-length arbitrary-offset area of memory which resides
2980 * within a 0 or higher order page. Multiple fragments within that page
2981 * are individually refcounted, in the page's reference counter.
2983 * The page_frag functions below provide a simple allocation framework for
2984 * page fragments. This is used by the network stack and network device
2985 * drivers to provide a backing region of memory for use as either an
2986 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
2988 static struct page *__page_frag_refill(struct page_frag_cache *nc,
2991 struct page *page = NULL;
2992 gfp_t gfp = gfp_mask;
2994 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
2995 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
2997 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
2998 PAGE_FRAG_CACHE_MAX_ORDER);
2999 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3001 if (unlikely(!page))
3002 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3004 nc->va = page ? page_address(page) : NULL;
3009 void *__alloc_page_frag(struct page_frag_cache *nc,
3010 unsigned int fragsz, gfp_t gfp_mask)
3012 unsigned int size = PAGE_SIZE;
3016 if (unlikely(!nc->va)) {
3018 page = __page_frag_refill(nc, gfp_mask);
3022 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3023 /* if size can vary use size else just use PAGE_SIZE */
3026 /* Even if we own the page, we do not use atomic_set().
3027 * This would break get_page_unless_zero() users.
3029 atomic_add(size - 1, &page->_count);
3031 /* reset page count bias and offset to start of new frag */
3032 nc->pfmemalloc = page->pfmemalloc;
3033 nc->pagecnt_bias = size;
3037 offset = nc->offset - fragsz;
3038 if (unlikely(offset < 0)) {
3039 page = virt_to_page(nc->va);
3041 if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count))
3044 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3045 /* if size can vary use size else just use PAGE_SIZE */
3048 /* OK, page count is 0, we can safely set it */
3049 atomic_set(&page->_count, size);
3051 /* reset page count bias and offset to start of new frag */
3052 nc->pagecnt_bias = size;
3053 offset = size - fragsz;
3057 nc->offset = offset;
3059 return nc->va + offset;
3061 EXPORT_SYMBOL(__alloc_page_frag);
3064 * Frees a page fragment allocated out of either a compound or order 0 page.
3066 void __free_page_frag(void *addr)
3068 struct page *page = virt_to_head_page(addr);
3070 if (unlikely(put_page_testzero(page)))
3071 __free_pages_ok(page, compound_order(page));
3073 EXPORT_SYMBOL(__free_page_frag);
3076 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3077 * of the current memory cgroup.
3079 * It should be used when the caller would like to use kmalloc, but since the
3080 * allocation is large, it has to fall back to the page allocator.
3082 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3085 struct mem_cgroup *memcg = NULL;
3087 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
3089 page = alloc_pages(gfp_mask, order);
3090 memcg_kmem_commit_charge(page, memcg, order);
3094 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3097 struct mem_cgroup *memcg = NULL;
3099 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
3101 page = alloc_pages_node(nid, gfp_mask, order);
3102 memcg_kmem_commit_charge(page, memcg, order);
3107 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3110 void __free_kmem_pages(struct page *page, unsigned int order)
3112 memcg_kmem_uncharge_pages(page, order);
3113 __free_pages(page, order);
3116 void free_kmem_pages(unsigned long addr, unsigned int order)
3119 VM_BUG_ON(!virt_addr_valid((void *)addr));
3120 __free_kmem_pages(virt_to_page((void *)addr), order);
3124 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
3127 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3128 unsigned long used = addr + PAGE_ALIGN(size);
3130 split_page(virt_to_page((void *)addr), order);
3131 while (used < alloc_end) {
3136 return (void *)addr;
3140 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3141 * @size: the number of bytes to allocate
3142 * @gfp_mask: GFP flags for the allocation
3144 * This function is similar to alloc_pages(), except that it allocates the
3145 * minimum number of pages to satisfy the request. alloc_pages() can only
3146 * allocate memory in power-of-two pages.
3148 * This function is also limited by MAX_ORDER.
3150 * Memory allocated by this function must be released by free_pages_exact().
3152 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3154 unsigned int order = get_order(size);
3157 addr = __get_free_pages(gfp_mask, order);
3158 return make_alloc_exact(addr, order, size);
3160 EXPORT_SYMBOL(alloc_pages_exact);
3163 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3165 * @nid: the preferred node ID where memory should be allocated
3166 * @size: the number of bytes to allocate
3167 * @gfp_mask: GFP flags for the allocation
3169 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3171 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
3174 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3176 unsigned order = get_order(size);
3177 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3180 return make_alloc_exact((unsigned long)page_address(p), order, size);
3184 * free_pages_exact - release memory allocated via alloc_pages_exact()
3185 * @virt: the value returned by alloc_pages_exact.
3186 * @size: size of allocation, same value as passed to alloc_pages_exact().
3188 * Release the memory allocated by a previous call to alloc_pages_exact.
3190 void free_pages_exact(void *virt, size_t size)
3192 unsigned long addr = (unsigned long)virt;
3193 unsigned long end = addr + PAGE_ALIGN(size);
3195 while (addr < end) {
3200 EXPORT_SYMBOL(free_pages_exact);
3203 * nr_free_zone_pages - count number of pages beyond high watermark
3204 * @offset: The zone index of the highest zone
3206 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3207 * high watermark within all zones at or below a given zone index. For each
3208 * zone, the number of pages is calculated as:
3209 * managed_pages - high_pages
3211 static unsigned long nr_free_zone_pages(int offset)
3216 /* Just pick one node, since fallback list is circular */
3217 unsigned long sum = 0;
3219 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3221 for_each_zone_zonelist(zone, z, zonelist, offset) {
3222 unsigned long size = zone->managed_pages;
3223 unsigned long high = high_wmark_pages(zone);
3232 * nr_free_buffer_pages - count number of pages beyond high watermark
3234 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3235 * watermark within ZONE_DMA and ZONE_NORMAL.
3237 unsigned long nr_free_buffer_pages(void)
3239 return nr_free_zone_pages(gfp_zone(GFP_USER));
3241 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3244 * nr_free_pagecache_pages - count number of pages beyond high watermark
3246 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3247 * high watermark within all zones.
3249 unsigned long nr_free_pagecache_pages(void)
3251 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3254 static inline void show_node(struct zone *zone)
3256 if (IS_ENABLED(CONFIG_NUMA))
3257 printk("Node %d ", zone_to_nid(zone));
3260 void si_meminfo(struct sysinfo *val)
3262 val->totalram = totalram_pages;
3263 val->sharedram = global_page_state(NR_SHMEM);
3264 val->freeram = global_page_state(NR_FREE_PAGES);
3265 val->bufferram = nr_blockdev_pages();
3266 val->totalhigh = totalhigh_pages;
3267 val->freehigh = nr_free_highpages();
3268 val->mem_unit = PAGE_SIZE;
3271 EXPORT_SYMBOL(si_meminfo);
3274 void si_meminfo_node(struct sysinfo *val, int nid)
3276 int zone_type; /* needs to be signed */
3277 unsigned long managed_pages = 0;
3278 pg_data_t *pgdat = NODE_DATA(nid);
3280 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
3281 managed_pages += pgdat->node_zones[zone_type].managed_pages;
3282 val->totalram = managed_pages;
3283 val->sharedram = node_page_state(nid, NR_SHMEM);
3284 val->freeram = node_page_state(nid, NR_FREE_PAGES);
3285 #ifdef CONFIG_HIGHMEM
3286 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
3287 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
3293 val->mem_unit = PAGE_SIZE;
3298 * Determine whether the node should be displayed or not, depending on whether
3299 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3301 bool skip_free_areas_node(unsigned int flags, int nid)
3304 unsigned int cpuset_mems_cookie;
3306 if (!(flags & SHOW_MEM_FILTER_NODES))
3310 cpuset_mems_cookie = read_mems_allowed_begin();
3311 ret = !node_isset(nid, cpuset_current_mems_allowed);
3312 } while (read_mems_allowed_retry(cpuset_mems_cookie));
3317 #define K(x) ((x) << (PAGE_SHIFT-10))
3319 static void show_migration_types(unsigned char type)
3321 static const char types[MIGRATE_TYPES] = {
3322 [MIGRATE_UNMOVABLE] = 'U',
3323 [MIGRATE_RECLAIMABLE] = 'E',
3324 [MIGRATE_MOVABLE] = 'M',
3325 [MIGRATE_RESERVE] = 'R',
3327 [MIGRATE_CMA] = 'C',
3329 #ifdef CONFIG_MEMORY_ISOLATION
3330 [MIGRATE_ISOLATE] = 'I',
3333 char tmp[MIGRATE_TYPES + 1];
3337 for (i = 0; i < MIGRATE_TYPES; i++) {
3338 if (type & (1 << i))
3343 printk("(%s) ", tmp);
3347 * Show free area list (used inside shift_scroll-lock stuff)
3348 * We also calculate the percentage fragmentation. We do this by counting the
3349 * memory on each free list with the exception of the first item on the list.
3352 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3355 void show_free_areas(unsigned int filter)
3357 unsigned long free_pcp = 0;
3361 for_each_populated_zone(zone) {
3362 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3365 for_each_online_cpu(cpu)
3366 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3369 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3370 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3371 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3372 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3373 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3374 " free:%lu free_pcp:%lu free_cma:%lu\n",
3375 global_page_state(NR_ACTIVE_ANON),
3376 global_page_state(NR_INACTIVE_ANON),
3377 global_page_state(NR_ISOLATED_ANON),
3378 global_page_state(NR_ACTIVE_FILE),
3379 global_page_state(NR_INACTIVE_FILE),
3380 global_page_state(NR_ISOLATED_FILE),
3381 global_page_state(NR_UNEVICTABLE),
3382 global_page_state(NR_FILE_DIRTY),
3383 global_page_state(NR_WRITEBACK),
3384 global_page_state(NR_UNSTABLE_NFS),
3385 global_page_state(NR_SLAB_RECLAIMABLE),
3386 global_page_state(NR_SLAB_UNRECLAIMABLE),
3387 global_page_state(NR_FILE_MAPPED),
3388 global_page_state(NR_SHMEM),
3389 global_page_state(NR_PAGETABLE),
3390 global_page_state(NR_BOUNCE),
3391 global_page_state(NR_FREE_PAGES),
3393 global_page_state(NR_FREE_CMA_PAGES));
3395 for_each_populated_zone(zone) {
3398 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3402 for_each_online_cpu(cpu)
3403 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
3411 " active_anon:%lukB"
3412 " inactive_anon:%lukB"
3413 " active_file:%lukB"
3414 " inactive_file:%lukB"
3415 " unevictable:%lukB"
3416 " isolated(anon):%lukB"
3417 " isolated(file):%lukB"
3425 " slab_reclaimable:%lukB"
3426 " slab_unreclaimable:%lukB"
3427 " kernel_stack:%lukB"
3434 " writeback_tmp:%lukB"
3435 " pages_scanned:%lu"
3436 " all_unreclaimable? %s"
3439 K(zone_page_state(zone, NR_FREE_PAGES)),
3440 K(min_wmark_pages(zone)),
3441 K(low_wmark_pages(zone)),
3442 K(high_wmark_pages(zone)),
3443 K(zone_page_state(zone, NR_ACTIVE_ANON)),
3444 K(zone_page_state(zone, NR_INACTIVE_ANON)),
3445 K(zone_page_state(zone, NR_ACTIVE_FILE)),
3446 K(zone_page_state(zone, NR_INACTIVE_FILE)),
3447 K(zone_page_state(zone, NR_UNEVICTABLE)),
3448 K(zone_page_state(zone, NR_ISOLATED_ANON)),
3449 K(zone_page_state(zone, NR_ISOLATED_FILE)),
3450 K(zone->present_pages),
3451 K(zone->managed_pages),
3452 K(zone_page_state(zone, NR_MLOCK)),
3453 K(zone_page_state(zone, NR_FILE_DIRTY)),
3454 K(zone_page_state(zone, NR_WRITEBACK)),
3455 K(zone_page_state(zone, NR_FILE_MAPPED)),
3456 K(zone_page_state(zone, NR_SHMEM)),
3457 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
3458 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3459 zone_page_state(zone, NR_KERNEL_STACK) *
3461 K(zone_page_state(zone, NR_PAGETABLE)),
3462 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
3463 K(zone_page_state(zone, NR_BOUNCE)),
3465 K(this_cpu_read(zone->pageset->pcp.count)),
3466 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3467 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
3468 K(zone_page_state(zone, NR_PAGES_SCANNED)),
3469 (!zone_reclaimable(zone) ? "yes" : "no")
3471 printk("lowmem_reserve[]:");
3472 for (i = 0; i < MAX_NR_ZONES; i++)
3473 printk(" %ld", zone->lowmem_reserve[i]);
3477 for_each_populated_zone(zone) {
3478 unsigned long nr[MAX_ORDER], flags, order, total = 0;
3479 unsigned char types[MAX_ORDER];
3481 if (skip_free_areas_node(filter, zone_to_nid(zone)))
3484 printk("%s: ", zone->name);
3486 spin_lock_irqsave(&zone->lock, flags);
3487 for (order = 0; order < MAX_ORDER; order++) {
3488 struct free_area *area = &zone->free_area[order];
3491 nr[order] = area->nr_free;
3492 total += nr[order] << order;
3495 for (type = 0; type < MIGRATE_TYPES; type++) {
3496 if (!list_empty(&area->free_list[type]))
3497 types[order] |= 1 << type;
3500 spin_unlock_irqrestore(&zone->lock, flags);
3501 for (order = 0; order < MAX_ORDER; order++) {
3502 printk("%lu*%lukB ", nr[order], K(1UL) << order);
3504 show_migration_types(types[order]);
3506 printk("= %lukB\n", K(total));
3509 hugetlb_show_meminfo();
3511 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3513 show_swap_cache_info();
3516 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3518 zoneref->zone = zone;
3519 zoneref->zone_idx = zone_idx(zone);
3523 * Builds allocation fallback zone lists.
3525 * Add all populated zones of a node to the zonelist.
3527 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3531 enum zone_type zone_type = MAX_NR_ZONES;
3535 zone = pgdat->node_zones + zone_type;
3536 if (populated_zone(zone)) {
3537 zoneref_set_zone(zone,
3538 &zonelist->_zonerefs[nr_zones++]);
3539 check_highest_zone(zone_type);
3541 } while (zone_type);
3549 * 0 = automatic detection of better ordering.
3550 * 1 = order by ([node] distance, -zonetype)
3551 * 2 = order by (-zonetype, [node] distance)
3553 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3554 * the same zonelist. So only NUMA can configure this param.
3556 #define ZONELIST_ORDER_DEFAULT 0
3557 #define ZONELIST_ORDER_NODE 1
3558 #define ZONELIST_ORDER_ZONE 2
3560 /* zonelist order in the kernel.
3561 * set_zonelist_order() will set this to NODE or ZONE.
3563 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3564 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3568 /* The value user specified ....changed by config */
3569 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3570 /* string for sysctl */
3571 #define NUMA_ZONELIST_ORDER_LEN 16
3572 char numa_zonelist_order[16] = "default";
3575 * interface for configure zonelist ordering.
3576 * command line option "numa_zonelist_order"
3577 * = "[dD]efault - default, automatic configuration.
3578 * = "[nN]ode - order by node locality, then by zone within node
3579 * = "[zZ]one - order by zone, then by locality within zone
3582 static int __parse_numa_zonelist_order(char *s)
3584 if (*s == 'd' || *s == 'D') {
3585 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3586 } else if (*s == 'n' || *s == 'N') {
3587 user_zonelist_order = ZONELIST_ORDER_NODE;
3588 } else if (*s == 'z' || *s == 'Z') {
3589 user_zonelist_order = ZONELIST_ORDER_ZONE;
3592 "Ignoring invalid numa_zonelist_order value: "
3599 static __init int setup_numa_zonelist_order(char *s)
3606 ret = __parse_numa_zonelist_order(s);
3608 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3612 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3615 * sysctl handler for numa_zonelist_order
3617 int numa_zonelist_order_handler(struct ctl_table *table, int write,
3618 void __user *buffer, size_t *length,
3621 char saved_string[NUMA_ZONELIST_ORDER_LEN];
3623 static DEFINE_MUTEX(zl_order_mutex);
3625 mutex_lock(&zl_order_mutex);
3627 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
3631 strcpy(saved_string, (char *)table->data);
3633 ret = proc_dostring(table, write, buffer, length, ppos);
3637 int oldval = user_zonelist_order;
3639 ret = __parse_numa_zonelist_order((char *)table->data);
3642 * bogus value. restore saved string
3644 strncpy((char *)table->data, saved_string,
3645 NUMA_ZONELIST_ORDER_LEN);
3646 user_zonelist_order = oldval;
3647 } else if (oldval != user_zonelist_order) {
3648 mutex_lock(&zonelists_mutex);
3649 build_all_zonelists(NULL, NULL);
3650 mutex_unlock(&zonelists_mutex);
3654 mutex_unlock(&zl_order_mutex);
3659 #define MAX_NODE_LOAD (nr_online_nodes)
3660 static int node_load[MAX_NUMNODES];
3663 * find_next_best_node - find the next node that should appear in a given node's fallback list
3664 * @node: node whose fallback list we're appending
3665 * @used_node_mask: nodemask_t of already used nodes
3667 * We use a number of factors to determine which is the next node that should
3668 * appear on a given node's fallback list. The node should not have appeared
3669 * already in @node's fallback list, and it should be the next closest node
3670 * according to the distance array (which contains arbitrary distance values
3671 * from each node to each node in the system), and should also prefer nodes
3672 * with no CPUs, since presumably they'll have very little allocation pressure
3673 * on them otherwise.
3674 * It returns -1 if no node is found.
3676 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3679 int min_val = INT_MAX;
3680 int best_node = NUMA_NO_NODE;
3681 const struct cpumask *tmp = cpumask_of_node(0);
3683 /* Use the local node if we haven't already */
3684 if (!node_isset(node, *used_node_mask)) {
3685 node_set(node, *used_node_mask);
3689 for_each_node_state(n, N_MEMORY) {
3691 /* Don't want a node to appear more than once */
3692 if (node_isset(n, *used_node_mask))
3695 /* Use the distance array to find the distance */
3696 val = node_distance(node, n);
3698 /* Penalize nodes under us ("prefer the next node") */
3701 /* Give preference to headless and unused nodes */
3702 tmp = cpumask_of_node(n);
3703 if (!cpumask_empty(tmp))
3704 val += PENALTY_FOR_NODE_WITH_CPUS;
3706 /* Slight preference for less loaded node */
3707 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3708 val += node_load[n];
3710 if (val < min_val) {
3717 node_set(best_node, *used_node_mask);
3724 * Build zonelists ordered by node and zones within node.
3725 * This results in maximum locality--normal zone overflows into local
3726 * DMA zone, if any--but risks exhausting DMA zone.
3728 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3731 struct zonelist *zonelist;
3733 zonelist = &pgdat->node_zonelists[0];
3734 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3736 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3737 zonelist->_zonerefs[j].zone = NULL;
3738 zonelist->_zonerefs[j].zone_idx = 0;
3742 * Build gfp_thisnode zonelists
3744 static void build_thisnode_zonelists(pg_data_t *pgdat)
3747 struct zonelist *zonelist;
3749 zonelist = &pgdat->node_zonelists[1];
3750 j = build_zonelists_node(pgdat, zonelist, 0);
3751 zonelist->_zonerefs[j].zone = NULL;
3752 zonelist->_zonerefs[j].zone_idx = 0;
3756 * Build zonelists ordered by zone and nodes within zones.
3757 * This results in conserving DMA zone[s] until all Normal memory is
3758 * exhausted, but results in overflowing to remote node while memory
3759 * may still exist in local DMA zone.
3761 static int node_order[MAX_NUMNODES];
3763 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3766 int zone_type; /* needs to be signed */
3768 struct zonelist *zonelist;
3770 zonelist = &pgdat->node_zonelists[0];
3772 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3773 for (j = 0; j < nr_nodes; j++) {
3774 node = node_order[j];
3775 z = &NODE_DATA(node)->node_zones[zone_type];
3776 if (populated_zone(z)) {
3778 &zonelist->_zonerefs[pos++]);
3779 check_highest_zone(zone_type);
3783 zonelist->_zonerefs[pos].zone = NULL;
3784 zonelist->_zonerefs[pos].zone_idx = 0;
3787 #if defined(CONFIG_64BIT)
3789 * Devices that require DMA32/DMA are relatively rare and do not justify a
3790 * penalty to every machine in case the specialised case applies. Default
3791 * to Node-ordering on 64-bit NUMA machines
3793 static int default_zonelist_order(void)
3795 return ZONELIST_ORDER_NODE;
3799 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
3800 * by the kernel. If processes running on node 0 deplete the low memory zone
3801 * then reclaim will occur more frequency increasing stalls and potentially
3802 * be easier to OOM if a large percentage of the zone is under writeback or
3803 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
3804 * Hence, default to zone ordering on 32-bit.
3806 static int default_zonelist_order(void)
3808 return ZONELIST_ORDER_ZONE;
3810 #endif /* CONFIG_64BIT */
3812 static void set_zonelist_order(void)
3814 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3815 current_zonelist_order = default_zonelist_order();
3817 current_zonelist_order = user_zonelist_order;
3820 static void build_zonelists(pg_data_t *pgdat)
3824 nodemask_t used_mask;
3825 int local_node, prev_node;
3826 struct zonelist *zonelist;
3827 int order = current_zonelist_order;
3829 /* initialize zonelists */
3830 for (i = 0; i < MAX_ZONELISTS; i++) {
3831 zonelist = pgdat->node_zonelists + i;
3832 zonelist->_zonerefs[0].zone = NULL;
3833 zonelist->_zonerefs[0].zone_idx = 0;
3836 /* NUMA-aware ordering of nodes */
3837 local_node = pgdat->node_id;
3838 load = nr_online_nodes;
3839 prev_node = local_node;
3840 nodes_clear(used_mask);
3842 memset(node_order, 0, sizeof(node_order));
3845 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3847 * We don't want to pressure a particular node.
3848 * So adding penalty to the first node in same
3849 * distance group to make it round-robin.
3851 if (node_distance(local_node, node) !=
3852 node_distance(local_node, prev_node))
3853 node_load[node] = load;
3857 if (order == ZONELIST_ORDER_NODE)
3858 build_zonelists_in_node_order(pgdat, node);
3860 node_order[j++] = node; /* remember order */
3863 if (order == ZONELIST_ORDER_ZONE) {
3864 /* calculate node order -- i.e., DMA last! */
3865 build_zonelists_in_zone_order(pgdat, j);
3868 build_thisnode_zonelists(pgdat);
3871 /* Construct the zonelist performance cache - see further mmzone.h */
3872 static void build_zonelist_cache(pg_data_t *pgdat)
3874 struct zonelist *zonelist;
3875 struct zonelist_cache *zlc;
3878 zonelist = &pgdat->node_zonelists[0];
3879 zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3880 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3881 for (z = zonelist->_zonerefs; z->zone; z++)
3882 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3885 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3887 * Return node id of node used for "local" allocations.
3888 * I.e., first node id of first zone in arg node's generic zonelist.
3889 * Used for initializing percpu 'numa_mem', which is used primarily
3890 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3892 int local_memory_node(int node)
3896 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3897 gfp_zone(GFP_KERNEL),
3904 #else /* CONFIG_NUMA */
3906 static void set_zonelist_order(void)
3908 current_zonelist_order = ZONELIST_ORDER_ZONE;
3911 static void build_zonelists(pg_data_t *pgdat)
3913 int node, local_node;
3915 struct zonelist *zonelist;
3917 local_node = pgdat->node_id;
3919 zonelist = &pgdat->node_zonelists[0];
3920 j = build_zonelists_node(pgdat, zonelist, 0);
3923 * Now we build the zonelist so that it contains the zones
3924 * of all the other nodes.
3925 * We don't want to pressure a particular node, so when
3926 * building the zones for node N, we make sure that the
3927 * zones coming right after the local ones are those from
3928 * node N+1 (modulo N)
3930 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3931 if (!node_online(node))
3933 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3935 for (node = 0; node < local_node; node++) {
3936 if (!node_online(node))
3938 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
3941 zonelist->_zonerefs[j].zone = NULL;
3942 zonelist->_zonerefs[j].zone_idx = 0;
3945 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3946 static void build_zonelist_cache(pg_data_t *pgdat)
3948 pgdat->node_zonelists[0].zlcache_ptr = NULL;
3951 #endif /* CONFIG_NUMA */
3954 * Boot pageset table. One per cpu which is going to be used for all
3955 * zones and all nodes. The parameters will be set in such a way
3956 * that an item put on a list will immediately be handed over to
3957 * the buddy list. This is safe since pageset manipulation is done
3958 * with interrupts disabled.
3960 * The boot_pagesets must be kept even after bootup is complete for
3961 * unused processors and/or zones. They do play a role for bootstrapping
3962 * hotplugged processors.
3964 * zoneinfo_show() and maybe other functions do
3965 * not check if the processor is online before following the pageset pointer.
3966 * Other parts of the kernel may not check if the zone is available.
3968 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3969 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3970 static void setup_zone_pageset(struct zone *zone);
3973 * Global mutex to protect against size modification of zonelists
3974 * as well as to serialize pageset setup for the new populated zone.
3976 DEFINE_MUTEX(zonelists_mutex);
3978 /* return values int ....just for stop_machine() */
3979 static int __build_all_zonelists(void *data)
3983 pg_data_t *self = data;
3986 memset(node_load, 0, sizeof(node_load));
3989 if (self && !node_online(self->node_id)) {
3990 build_zonelists(self);
3991 build_zonelist_cache(self);
3994 for_each_online_node(nid) {
3995 pg_data_t *pgdat = NODE_DATA(nid);
3997 build_zonelists(pgdat);
3998 build_zonelist_cache(pgdat);
4002 * Initialize the boot_pagesets that are going to be used
4003 * for bootstrapping processors. The real pagesets for
4004 * each zone will be allocated later when the per cpu
4005 * allocator is available.
4007 * boot_pagesets are used also for bootstrapping offline
4008 * cpus if the system is already booted because the pagesets
4009 * are needed to initialize allocators on a specific cpu too.
4010 * F.e. the percpu allocator needs the page allocator which
4011 * needs the percpu allocator in order to allocate its pagesets
4012 * (a chicken-egg dilemma).
4014 for_each_possible_cpu(cpu) {
4015 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4017 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4019 * We now know the "local memory node" for each node--
4020 * i.e., the node of the first zone in the generic zonelist.
4021 * Set up numa_mem percpu variable for on-line cpus. During
4022 * boot, only the boot cpu should be on-line; we'll init the
4023 * secondary cpus' numa_mem as they come on-line. During
4024 * node/memory hotplug, we'll fixup all on-line cpus.
4026 if (cpu_online(cpu))
4027 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4034 static noinline void __init
4035 build_all_zonelists_init(void)
4037 __build_all_zonelists(NULL);
4038 mminit_verify_zonelist();
4039 cpuset_init_current_mems_allowed();
4043 * Called with zonelists_mutex held always
4044 * unless system_state == SYSTEM_BOOTING.
4046 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4047 * [we're only called with non-NULL zone through __meminit paths] and
4048 * (2) call of __init annotated helper build_all_zonelists_init
4049 * [protected by SYSTEM_BOOTING].
4051 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4053 set_zonelist_order();
4055 if (system_state == SYSTEM_BOOTING) {
4056 build_all_zonelists_init();
4058 #ifdef CONFIG_MEMORY_HOTPLUG
4060 setup_zone_pageset(zone);
4062 /* we have to stop all cpus to guarantee there is no user
4064 stop_machine(__build_all_zonelists, pgdat, NULL);
4065 /* cpuset refresh routine should be here */
4067 vm_total_pages = nr_free_pagecache_pages();
4069 * Disable grouping by mobility if the number of pages in the
4070 * system is too low to allow the mechanism to work. It would be
4071 * more accurate, but expensive to check per-zone. This check is
4072 * made on memory-hotadd so a system can start with mobility
4073 * disabled and enable it later
4075 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4076 page_group_by_mobility_disabled = 1;
4078 page_group_by_mobility_disabled = 0;
4080 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4081 "Total pages: %ld\n",
4083 zonelist_order_name[current_zonelist_order],
4084 page_group_by_mobility_disabled ? "off" : "on",
4087 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4092 * Helper functions to size the waitqueue hash table.
4093 * Essentially these want to choose hash table sizes sufficiently
4094 * large so that collisions trying to wait on pages are rare.
4095 * But in fact, the number of active page waitqueues on typical
4096 * systems is ridiculously low, less than 200. So this is even
4097 * conservative, even though it seems large.
4099 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4100 * waitqueues, i.e. the size of the waitq table given the number of pages.
4102 #define PAGES_PER_WAITQUEUE 256
4104 #ifndef CONFIG_MEMORY_HOTPLUG
4105 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4107 unsigned long size = 1;
4109 pages /= PAGES_PER_WAITQUEUE;
4111 while (size < pages)
4115 * Once we have dozens or even hundreds of threads sleeping
4116 * on IO we've got bigger problems than wait queue collision.
4117 * Limit the size of the wait table to a reasonable size.
4119 size = min(size, 4096UL);
4121 return max(size, 4UL);
4125 * A zone's size might be changed by hot-add, so it is not possible to determine
4126 * a suitable size for its wait_table. So we use the maximum size now.
4128 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4130 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4131 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4132 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4134 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4135 * or more by the traditional way. (See above). It equals:
4137 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4138 * ia64(16K page size) : = ( 8G + 4M)byte.
4139 * powerpc (64K page size) : = (32G +16M)byte.
4141 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4148 * This is an integer logarithm so that shifts can be used later
4149 * to extract the more random high bits from the multiplicative
4150 * hash function before the remainder is taken.
4152 static inline unsigned long wait_table_bits(unsigned long size)
4158 * Check if a pageblock contains reserved pages
4160 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
4164 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4165 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
4172 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
4173 * of blocks reserved is based on min_wmark_pages(zone). The memory within
4174 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
4175 * higher will lead to a bigger reserve which will get freed as contiguous
4176 * blocks as reclaim kicks in
4178 static void setup_zone_migrate_reserve(struct zone *zone)
4180 unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
4182 unsigned long block_migratetype;
4187 * Get the start pfn, end pfn and the number of blocks to reserve
4188 * We have to be careful to be aligned to pageblock_nr_pages to
4189 * make sure that we always check pfn_valid for the first page in
4192 start_pfn = zone->zone_start_pfn;
4193 end_pfn = zone_end_pfn(zone);
4194 start_pfn = roundup(start_pfn, pageblock_nr_pages);
4195 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
4199 * Reserve blocks are generally in place to help high-order atomic
4200 * allocations that are short-lived. A min_free_kbytes value that
4201 * would result in more than 2 reserve blocks for atomic allocations
4202 * is assumed to be in place to help anti-fragmentation for the
4203 * future allocation of hugepages at runtime.
4205 reserve = min(2, reserve);
4206 old_reserve = zone->nr_migrate_reserve_block;
4208 /* When memory hot-add, we almost always need to do nothing */
4209 if (reserve == old_reserve)
4211 zone->nr_migrate_reserve_block = reserve;
4213 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
4214 if (!pfn_valid(pfn))
4216 page = pfn_to_page(pfn);
4218 /* Watch out for overlapping nodes */
4219 if (page_to_nid(page) != zone_to_nid(zone))
4222 block_migratetype = get_pageblock_migratetype(page);
4224 /* Only test what is necessary when the reserves are not met */
4227 * Blocks with reserved pages will never free, skip
4230 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
4231 if (pageblock_is_reserved(pfn, block_end_pfn))
4234 /* If this block is reserved, account for it */
4235 if (block_migratetype == MIGRATE_RESERVE) {
4240 /* Suitable for reserving if this block is movable */
4241 if (block_migratetype == MIGRATE_MOVABLE) {
4242 set_pageblock_migratetype(page,
4244 move_freepages_block(zone, page,
4249 } else if (!old_reserve) {
4251 * At boot time we don't need to scan the whole zone
4252 * for turning off MIGRATE_RESERVE.
4258 * If the reserve is met and this is a previous reserved block,
4261 if (block_migratetype == MIGRATE_RESERVE) {
4262 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4263 move_freepages_block(zone, page, MIGRATE_MOVABLE);
4269 * Initially all pages are reserved - free ones are freed
4270 * up by free_all_bootmem() once the early boot process is
4271 * done. Non-atomic initialization, single-pass.
4273 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4274 unsigned long start_pfn, enum memmap_context context)
4276 unsigned long end_pfn = start_pfn + size;
4280 if (highest_memmap_pfn < end_pfn - 1)
4281 highest_memmap_pfn = end_pfn - 1;
4283 z = &NODE_DATA(nid)->node_zones[zone];
4284 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4286 * There can be holes in boot-time mem_map[]s
4287 * handed to this function. They do not
4288 * exist on hotplugged memory.
4290 if (context == MEMMAP_EARLY) {
4291 if (!early_pfn_valid(pfn))
4293 if (!early_pfn_in_nid(pfn, nid))
4296 __init_single_pfn(pfn, zone, nid);
4300 static void __meminit zone_init_free_lists(struct zone *zone)
4302 unsigned int order, t;
4303 for_each_migratetype_order(order, t) {
4304 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
4305 zone->free_area[order].nr_free = 0;
4309 #ifndef __HAVE_ARCH_MEMMAP_INIT
4310 #define memmap_init(size, nid, zone, start_pfn) \
4311 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4314 static int zone_batchsize(struct zone *zone)
4320 * The per-cpu-pages pools are set to around 1000th of the
4321 * size of the zone. But no more than 1/2 of a meg.
4323 * OK, so we don't know how big the cache is. So guess.
4325 batch = zone->managed_pages / 1024;
4326 if (batch * PAGE_SIZE > 512 * 1024)
4327 batch = (512 * 1024) / PAGE_SIZE;
4328 batch /= 4; /* We effectively *= 4 below */
4333 * Clamp the batch to a 2^n - 1 value. Having a power
4334 * of 2 value was found to be more likely to have
4335 * suboptimal cache aliasing properties in some cases.
4337 * For example if 2 tasks are alternately allocating
4338 * batches of pages, one task can end up with a lot
4339 * of pages of one half of the possible page colors
4340 * and the other with pages of the other colors.
4342 batch = rounddown_pow_of_two(batch + batch/2) - 1;
4347 /* The deferral and batching of frees should be suppressed under NOMMU
4350 * The problem is that NOMMU needs to be able to allocate large chunks
4351 * of contiguous memory as there's no hardware page translation to
4352 * assemble apparent contiguous memory from discontiguous pages.
4354 * Queueing large contiguous runs of pages for batching, however,
4355 * causes the pages to actually be freed in smaller chunks. As there
4356 * can be a significant delay between the individual batches being
4357 * recycled, this leads to the once large chunks of space being
4358 * fragmented and becoming unavailable for high-order allocations.
4365 * pcp->high and pcp->batch values are related and dependent on one another:
4366 * ->batch must never be higher then ->high.
4367 * The following function updates them in a safe manner without read side
4370 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4371 * those fields changing asynchronously (acording the the above rule).
4373 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4374 * outside of boot time (or some other assurance that no concurrent updaters
4377 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
4378 unsigned long batch)
4380 /* start with a fail safe value for batch */
4384 /* Update high, then batch, in order */
4391 /* a companion to pageset_set_high() */
4392 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
4394 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
4397 static void pageset_init(struct per_cpu_pageset *p)
4399 struct per_cpu_pages *pcp;
4402 memset(p, 0, sizeof(*p));
4406 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
4407 INIT_LIST_HEAD(&pcp->lists[migratetype]);
4410 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
4413 pageset_set_batch(p, batch);
4417 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4418 * to the value high for the pageset p.
4420 static void pageset_set_high(struct per_cpu_pageset *p,
4423 unsigned long batch = max(1UL, high / 4);
4424 if ((high / 4) > (PAGE_SHIFT * 8))
4425 batch = PAGE_SHIFT * 8;
4427 pageset_update(&p->pcp, high, batch);
4430 static void pageset_set_high_and_batch(struct zone *zone,
4431 struct per_cpu_pageset *pcp)
4433 if (percpu_pagelist_fraction)
4434 pageset_set_high(pcp,
4435 (zone->managed_pages /
4436 percpu_pagelist_fraction));
4438 pageset_set_batch(pcp, zone_batchsize(zone));
4441 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
4443 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
4446 pageset_set_high_and_batch(zone, pcp);
4449 static void __meminit setup_zone_pageset(struct zone *zone)
4452 zone->pageset = alloc_percpu(struct per_cpu_pageset);
4453 for_each_possible_cpu(cpu)
4454 zone_pageset_init(zone, cpu);
4458 * Allocate per cpu pagesets and initialize them.
4459 * Before this call only boot pagesets were available.
4461 void __init setup_per_cpu_pageset(void)
4465 for_each_populated_zone(zone)
4466 setup_zone_pageset(zone);
4469 static noinline __init_refok
4470 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4476 * The per-page waitqueue mechanism uses hashed waitqueues
4479 zone->wait_table_hash_nr_entries =
4480 wait_table_hash_nr_entries(zone_size_pages);
4481 zone->wait_table_bits =
4482 wait_table_bits(zone->wait_table_hash_nr_entries);
4483 alloc_size = zone->wait_table_hash_nr_entries
4484 * sizeof(wait_queue_head_t);
4486 if (!slab_is_available()) {
4487 zone->wait_table = (wait_queue_head_t *)
4488 memblock_virt_alloc_node_nopanic(
4489 alloc_size, zone->zone_pgdat->node_id);
4492 * This case means that a zone whose size was 0 gets new memory
4493 * via memory hot-add.
4494 * But it may be the case that a new node was hot-added. In
4495 * this case vmalloc() will not be able to use this new node's
4496 * memory - this wait_table must be initialized to use this new
4497 * node itself as well.
4498 * To use this new node's memory, further consideration will be
4501 zone->wait_table = vmalloc(alloc_size);
4503 if (!zone->wait_table)
4506 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4507 init_waitqueue_head(zone->wait_table + i);
4512 static __meminit void zone_pcp_init(struct zone *zone)
4515 * per cpu subsystem is not up at this point. The following code
4516 * relies on the ability of the linker to provide the
4517 * offset of a (static) per cpu variable into the per cpu area.
4519 zone->pageset = &boot_pageset;
4521 if (populated_zone(zone))
4522 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4523 zone->name, zone->present_pages,
4524 zone_batchsize(zone));
4527 int __meminit init_currently_empty_zone(struct zone *zone,
4528 unsigned long zone_start_pfn,
4530 enum memmap_context context)
4532 struct pglist_data *pgdat = zone->zone_pgdat;
4534 ret = zone_wait_table_init(zone, size);
4537 pgdat->nr_zones = zone_idx(zone) + 1;
4539 zone->zone_start_pfn = zone_start_pfn;
4541 mminit_dprintk(MMINIT_TRACE, "memmap_init",
4542 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4544 (unsigned long)zone_idx(zone),
4545 zone_start_pfn, (zone_start_pfn + size));
4547 zone_init_free_lists(zone);
4552 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4553 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4555 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4557 int __meminit __early_pfn_to_nid(unsigned long pfn)
4559 unsigned long start_pfn, end_pfn;
4562 * NOTE: The following SMP-unsafe globals are only used early in boot
4563 * when the kernel is running single-threaded.
4565 static unsigned long __meminitdata last_start_pfn, last_end_pfn;
4566 static int __meminitdata last_nid;
4568 if (last_start_pfn <= pfn && pfn < last_end_pfn)
4571 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
4573 last_start_pfn = start_pfn;
4574 last_end_pfn = end_pfn;
4580 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4582 int __meminit early_pfn_to_nid(unsigned long pfn)
4586 nid = __early_pfn_to_nid(pfn);
4589 /* just returns 0 */
4593 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4594 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4598 nid = __early_pfn_to_nid(pfn);
4599 if (nid >= 0 && nid != node)
4606 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4607 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4608 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4610 * If an architecture guarantees that all ranges registered contain no holes
4611 * and may be freed, this this function may be used instead of calling
4612 * memblock_free_early_nid() manually.
4614 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4616 unsigned long start_pfn, end_pfn;
4619 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4620 start_pfn = min(start_pfn, max_low_pfn);
4621 end_pfn = min(end_pfn, max_low_pfn);
4623 if (start_pfn < end_pfn)
4624 memblock_free_early_nid(PFN_PHYS(start_pfn),
4625 (end_pfn - start_pfn) << PAGE_SHIFT,
4631 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4632 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4634 * If an architecture guarantees that all ranges registered contain no holes and may
4635 * be freed, this function may be used instead of calling memory_present() manually.
4637 void __init sparse_memory_present_with_active_regions(int nid)
4639 unsigned long start_pfn, end_pfn;
4642 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4643 memory_present(this_nid, start_pfn, end_pfn);
4647 * get_pfn_range_for_nid - Return the start and end page frames for a node
4648 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4649 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4650 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4652 * It returns the start and end page frame of a node based on information
4653 * provided by memblock_set_node(). If called for a node
4654 * with no available memory, a warning is printed and the start and end
4657 void __meminit get_pfn_range_for_nid(unsigned int nid,
4658 unsigned long *start_pfn, unsigned long *end_pfn)
4660 unsigned long this_start_pfn, this_end_pfn;
4666 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
4667 *start_pfn = min(*start_pfn, this_start_pfn);
4668 *end_pfn = max(*end_pfn, this_end_pfn);
4671 if (*start_pfn == -1UL)
4676 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4677 * assumption is made that zones within a node are ordered in monotonic
4678 * increasing memory addresses so that the "highest" populated zone is used
4680 static void __init find_usable_zone_for_movable(void)
4683 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4684 if (zone_index == ZONE_MOVABLE)
4687 if (arch_zone_highest_possible_pfn[zone_index] >
4688 arch_zone_lowest_possible_pfn[zone_index])
4692 VM_BUG_ON(zone_index == -1);
4693 movable_zone = zone_index;
4697 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4698 * because it is sized independent of architecture. Unlike the other zones,
4699 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4700 * in each node depending on the size of each node and how evenly kernelcore
4701 * is distributed. This helper function adjusts the zone ranges
4702 * provided by the architecture for a given node by using the end of the
4703 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4704 * zones within a node are in order of monotonic increases memory addresses
4706 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4707 unsigned long zone_type,
4708 unsigned long node_start_pfn,
4709 unsigned long node_end_pfn,
4710 unsigned long *zone_start_pfn,
4711 unsigned long *zone_end_pfn)
4713 /* Only adjust if ZONE_MOVABLE is on this node */
4714 if (zone_movable_pfn[nid]) {
4715 /* Size ZONE_MOVABLE */
4716 if (zone_type == ZONE_MOVABLE) {
4717 *zone_start_pfn = zone_movable_pfn[nid];
4718 *zone_end_pfn = min(node_end_pfn,
4719 arch_zone_highest_possible_pfn[movable_zone]);
4721 /* Adjust for ZONE_MOVABLE starting within this range */
4722 } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4723 *zone_end_pfn > zone_movable_pfn[nid]) {
4724 *zone_end_pfn = zone_movable_pfn[nid];
4726 /* Check if this whole range is within ZONE_MOVABLE */
4727 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4728 *zone_start_pfn = *zone_end_pfn;
4733 * Return the number of pages a zone spans in a node, including holes
4734 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4736 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4737 unsigned long zone_type,
4738 unsigned long node_start_pfn,
4739 unsigned long node_end_pfn,
4740 unsigned long *ignored)
4742 unsigned long zone_start_pfn, zone_end_pfn;
4744 /* Get the start and end of the zone */
4745 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4746 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4747 adjust_zone_range_for_zone_movable(nid, zone_type,
4748 node_start_pfn, node_end_pfn,
4749 &zone_start_pfn, &zone_end_pfn);
4751 /* Check that this node has pages within the zone's required range */
4752 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4755 /* Move the zone boundaries inside the node if necessary */
4756 zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4757 zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4759 /* Return the spanned pages */
4760 return zone_end_pfn - zone_start_pfn;
4764 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4765 * then all holes in the requested range will be accounted for.
4767 unsigned long __meminit __absent_pages_in_range(int nid,
4768 unsigned long range_start_pfn,
4769 unsigned long range_end_pfn)
4771 unsigned long nr_absent = range_end_pfn - range_start_pfn;
4772 unsigned long start_pfn, end_pfn;
4775 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4776 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4777 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4778 nr_absent -= end_pfn - start_pfn;
4784 * absent_pages_in_range - Return number of page frames in holes within a range
4785 * @start_pfn: The start PFN to start searching for holes
4786 * @end_pfn: The end PFN to stop searching for holes
4788 * It returns the number of pages frames in memory holes within a range.
4790 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4791 unsigned long end_pfn)
4793 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4796 /* Return the number of page frames in holes in a zone on a node */
4797 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4798 unsigned long zone_type,
4799 unsigned long node_start_pfn,
4800 unsigned long node_end_pfn,
4801 unsigned long *ignored)
4803 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4804 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4805 unsigned long zone_start_pfn, zone_end_pfn;
4807 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4808 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4810 adjust_zone_range_for_zone_movable(nid, zone_type,
4811 node_start_pfn, node_end_pfn,
4812 &zone_start_pfn, &zone_end_pfn);
4813 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4816 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4817 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4818 unsigned long zone_type,
4819 unsigned long node_start_pfn,
4820 unsigned long node_end_pfn,
4821 unsigned long *zones_size)
4823 return zones_size[zone_type];
4826 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4827 unsigned long zone_type,
4828 unsigned long node_start_pfn,
4829 unsigned long node_end_pfn,
4830 unsigned long *zholes_size)
4835 return zholes_size[zone_type];
4838 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4840 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4841 unsigned long node_start_pfn,
4842 unsigned long node_end_pfn,
4843 unsigned long *zones_size,
4844 unsigned long *zholes_size)
4846 unsigned long realtotalpages = 0, totalpages = 0;
4849 for (i = 0; i < MAX_NR_ZONES; i++) {
4850 struct zone *zone = pgdat->node_zones + i;
4851 unsigned long size, real_size;
4853 size = zone_spanned_pages_in_node(pgdat->node_id, i,
4857 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
4858 node_start_pfn, node_end_pfn,
4860 zone->spanned_pages = size;
4861 zone->present_pages = real_size;
4864 realtotalpages += real_size;
4867 pgdat->node_spanned_pages = totalpages;
4868 pgdat->node_present_pages = realtotalpages;
4869 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4873 #ifndef CONFIG_SPARSEMEM
4875 * Calculate the size of the zone->blockflags rounded to an unsigned long
4876 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4877 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4878 * round what is now in bits to nearest long in bits, then return it in
4881 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
4883 unsigned long usemapsize;
4885 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
4886 usemapsize = roundup(zonesize, pageblock_nr_pages);
4887 usemapsize = usemapsize >> pageblock_order;
4888 usemapsize *= NR_PAGEBLOCK_BITS;
4889 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4891 return usemapsize / 8;
4894 static void __init setup_usemap(struct pglist_data *pgdat,
4896 unsigned long zone_start_pfn,
4897 unsigned long zonesize)
4899 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
4900 zone->pageblock_flags = NULL;
4902 zone->pageblock_flags =
4903 memblock_virt_alloc_node_nopanic(usemapsize,
4907 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
4908 unsigned long zone_start_pfn, unsigned long zonesize) {}
4909 #endif /* CONFIG_SPARSEMEM */
4911 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4913 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4914 void __paginginit set_pageblock_order(void)
4918 /* Check that pageblock_nr_pages has not already been setup */
4919 if (pageblock_order)
4922 if (HPAGE_SHIFT > PAGE_SHIFT)
4923 order = HUGETLB_PAGE_ORDER;
4925 order = MAX_ORDER - 1;
4928 * Assume the largest contiguous order of interest is a huge page.
4929 * This value may be variable depending on boot parameters on IA64 and
4932 pageblock_order = order;
4934 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4937 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4938 * is unused as pageblock_order is set at compile-time. See
4939 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4942 void __paginginit set_pageblock_order(void)
4946 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4948 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
4949 unsigned long present_pages)
4951 unsigned long pages = spanned_pages;
4954 * Provide a more accurate estimation if there are holes within
4955 * the zone and SPARSEMEM is in use. If there are holes within the
4956 * zone, each populated memory region may cost us one or two extra
4957 * memmap pages due to alignment because memmap pages for each
4958 * populated regions may not naturally algined on page boundary.
4959 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4961 if (spanned_pages > present_pages + (present_pages >> 4) &&
4962 IS_ENABLED(CONFIG_SPARSEMEM))
4963 pages = present_pages;
4965 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
4969 * Set up the zone data structures:
4970 * - mark all pages reserved
4971 * - mark all memory queues empty
4972 * - clear the memory bitmaps
4974 * NOTE: pgdat should get zeroed by caller.
4976 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4977 unsigned long node_start_pfn, unsigned long node_end_pfn)
4980 int nid = pgdat->node_id;
4981 unsigned long zone_start_pfn = pgdat->node_start_pfn;
4984 pgdat_resize_init(pgdat);
4985 #ifdef CONFIG_NUMA_BALANCING
4986 spin_lock_init(&pgdat->numabalancing_migrate_lock);
4987 pgdat->numabalancing_migrate_nr_pages = 0;
4988 pgdat->numabalancing_migrate_next_window = jiffies;
4990 init_waitqueue_head(&pgdat->kswapd_wait);
4991 init_waitqueue_head(&pgdat->pfmemalloc_wait);
4992 pgdat_page_ext_init(pgdat);
4994 for (j = 0; j < MAX_NR_ZONES; j++) {
4995 struct zone *zone = pgdat->node_zones + j;
4996 unsigned long size, realsize, freesize, memmap_pages;
4998 size = zone->spanned_pages;
4999 realsize = freesize = zone->present_pages;
5002 * Adjust freesize so that it accounts for how much memory
5003 * is used by this zone for memmap. This affects the watermark
5004 * and per-cpu initialisations
5006 memmap_pages = calc_memmap_size(size, realsize);
5007 if (!is_highmem_idx(j)) {
5008 if (freesize >= memmap_pages) {
5009 freesize -= memmap_pages;
5012 " %s zone: %lu pages used for memmap\n",
5013 zone_names[j], memmap_pages);
5016 " %s zone: %lu pages exceeds freesize %lu\n",
5017 zone_names[j], memmap_pages, freesize);
5020 /* Account for reserved pages */
5021 if (j == 0 && freesize > dma_reserve) {
5022 freesize -= dma_reserve;
5023 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5024 zone_names[0], dma_reserve);
5027 if (!is_highmem_idx(j))
5028 nr_kernel_pages += freesize;
5029 /* Charge for highmem memmap if there are enough kernel pages */
5030 else if (nr_kernel_pages > memmap_pages * 2)
5031 nr_kernel_pages -= memmap_pages;
5032 nr_all_pages += freesize;
5035 * Set an approximate value for lowmem here, it will be adjusted
5036 * when the bootmem allocator frees pages into the buddy system.
5037 * And all highmem pages will be managed by the buddy system.
5039 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5042 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5044 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5046 zone->name = zone_names[j];
5047 spin_lock_init(&zone->lock);
5048 spin_lock_init(&zone->lru_lock);
5049 zone_seqlock_init(zone);
5050 zone->zone_pgdat = pgdat;
5051 zone_pcp_init(zone);
5053 /* For bootup, initialized properly in watermark setup */
5054 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5056 lruvec_init(&zone->lruvec);
5060 set_pageblock_order();
5061 setup_usemap(pgdat, zone, zone_start_pfn, size);
5062 ret = init_currently_empty_zone(zone, zone_start_pfn,
5063 size, MEMMAP_EARLY);
5065 memmap_init(size, nid, j, zone_start_pfn);
5066 zone_start_pfn += size;
5070 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5072 /* Skip empty nodes */
5073 if (!pgdat->node_spanned_pages)
5076 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5077 /* ia64 gets its own node_mem_map, before this, without bootmem */
5078 if (!pgdat->node_mem_map) {
5079 unsigned long size, start, end;
5083 * The zone's endpoints aren't required to be MAX_ORDER
5084 * aligned but the node_mem_map endpoints must be in order
5085 * for the buddy allocator to function correctly.
5087 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5088 end = pgdat_end_pfn(pgdat);
5089 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5090 size = (end - start) * sizeof(struct page);
5091 map = alloc_remap(pgdat->node_id, size);
5093 map = memblock_virt_alloc_node_nopanic(size,
5095 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
5097 #ifndef CONFIG_NEED_MULTIPLE_NODES
5099 * With no DISCONTIG, the global mem_map is just set as node 0's
5101 if (pgdat == NODE_DATA(0)) {
5102 mem_map = NODE_DATA(0)->node_mem_map;
5103 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5104 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5105 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
5106 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5109 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5112 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5113 unsigned long node_start_pfn, unsigned long *zholes_size)
5115 pg_data_t *pgdat = NODE_DATA(nid);
5116 unsigned long start_pfn = 0;
5117 unsigned long end_pfn = 0;
5119 /* pg_data_t should be reset to zero when it's allocated */
5120 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5122 pgdat->node_id = nid;
5123 pgdat->node_start_pfn = node_start_pfn;
5124 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5125 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5126 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5127 (u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1);
5129 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5130 zones_size, zholes_size);
5132 alloc_node_mem_map(pgdat);
5133 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5134 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5135 nid, (unsigned long)pgdat,
5136 (unsigned long)pgdat->node_mem_map);
5139 free_area_init_core(pgdat, start_pfn, end_pfn);
5142 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5144 #if MAX_NUMNODES > 1
5146 * Figure out the number of possible node ids.
5148 void __init setup_nr_node_ids(void)
5151 unsigned int highest = 0;
5153 for_each_node_mask(node, node_possible_map)
5155 nr_node_ids = highest + 1;
5160 * node_map_pfn_alignment - determine the maximum internode alignment
5162 * This function should be called after node map is populated and sorted.
5163 * It calculates the maximum power of two alignment which can distinguish
5166 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5167 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5168 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5169 * shifted, 1GiB is enough and this function will indicate so.
5171 * This is used to test whether pfn -> nid mapping of the chosen memory
5172 * model has fine enough granularity to avoid incorrect mapping for the
5173 * populated node map.
5175 * Returns the determined alignment in pfn's. 0 if there is no alignment
5176 * requirement (single node).
5178 unsigned long __init node_map_pfn_alignment(void)
5180 unsigned long accl_mask = 0, last_end = 0;
5181 unsigned long start, end, mask;
5185 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5186 if (!start || last_nid < 0 || last_nid == nid) {
5193 * Start with a mask granular enough to pin-point to the
5194 * start pfn and tick off bits one-by-one until it becomes
5195 * too coarse to separate the current node from the last.
5197 mask = ~((1 << __ffs(start)) - 1);
5198 while (mask && last_end <= (start & (mask << 1)))
5201 /* accumulate all internode masks */
5205 /* convert mask to number of pages */
5206 return ~accl_mask + 1;
5209 /* Find the lowest pfn for a node */
5210 static unsigned long __init find_min_pfn_for_node(int nid)
5212 unsigned long min_pfn = ULONG_MAX;
5213 unsigned long start_pfn;
5216 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5217 min_pfn = min(min_pfn, start_pfn);
5219 if (min_pfn == ULONG_MAX) {
5221 "Could not find start_pfn for node %d\n", nid);
5229 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5231 * It returns the minimum PFN based on information provided via
5232 * memblock_set_node().
5234 unsigned long __init find_min_pfn_with_active_regions(void)
5236 return find_min_pfn_for_node(MAX_NUMNODES);
5240 * early_calculate_totalpages()
5241 * Sum pages in active regions for movable zone.
5242 * Populate N_MEMORY for calculating usable_nodes.
5244 static unsigned long __init early_calculate_totalpages(void)
5246 unsigned long totalpages = 0;
5247 unsigned long start_pfn, end_pfn;
5250 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5251 unsigned long pages = end_pfn - start_pfn;
5253 totalpages += pages;
5255 node_set_state(nid, N_MEMORY);
5261 * Find the PFN the Movable zone begins in each node. Kernel memory
5262 * is spread evenly between nodes as long as the nodes have enough
5263 * memory. When they don't, some nodes will have more kernelcore than
5266 static void __init find_zone_movable_pfns_for_nodes(void)
5269 unsigned long usable_startpfn;
5270 unsigned long kernelcore_node, kernelcore_remaining;
5271 /* save the state before borrow the nodemask */
5272 nodemask_t saved_node_state = node_states[N_MEMORY];
5273 unsigned long totalpages = early_calculate_totalpages();
5274 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
5275 struct memblock_region *r;
5277 /* Need to find movable_zone earlier when movable_node is specified. */
5278 find_usable_zone_for_movable();
5281 * If movable_node is specified, ignore kernelcore and movablecore
5284 if (movable_node_is_enabled()) {
5285 for_each_memblock(memory, r) {
5286 if (!memblock_is_hotpluggable(r))
5291 usable_startpfn = PFN_DOWN(r->base);
5292 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
5293 min(usable_startpfn, zone_movable_pfn[nid]) :
5301 * If movablecore=nn[KMG] was specified, calculate what size of
5302 * kernelcore that corresponds so that memory usable for
5303 * any allocation type is evenly spread. If both kernelcore
5304 * and movablecore are specified, then the value of kernelcore
5305 * will be used for required_kernelcore if it's greater than
5306 * what movablecore would have allowed.
5308 if (required_movablecore) {
5309 unsigned long corepages;
5312 * Round-up so that ZONE_MOVABLE is at least as large as what
5313 * was requested by the user
5315 required_movablecore =
5316 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
5317 corepages = totalpages - required_movablecore;
5319 required_kernelcore = max(required_kernelcore, corepages);
5322 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5323 if (!required_kernelcore)
5326 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5327 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
5330 /* Spread kernelcore memory as evenly as possible throughout nodes */
5331 kernelcore_node = required_kernelcore / usable_nodes;
5332 for_each_node_state(nid, N_MEMORY) {
5333 unsigned long start_pfn, end_pfn;
5336 * Recalculate kernelcore_node if the division per node
5337 * now exceeds what is necessary to satisfy the requested
5338 * amount of memory for the kernel
5340 if (required_kernelcore < kernelcore_node)
5341 kernelcore_node = required_kernelcore / usable_nodes;
5344 * As the map is walked, we track how much memory is usable
5345 * by the kernel using kernelcore_remaining. When it is
5346 * 0, the rest of the node is usable by ZONE_MOVABLE
5348 kernelcore_remaining = kernelcore_node;
5350 /* Go through each range of PFNs within this node */
5351 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5352 unsigned long size_pages;
5354 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
5355 if (start_pfn >= end_pfn)
5358 /* Account for what is only usable for kernelcore */
5359 if (start_pfn < usable_startpfn) {
5360 unsigned long kernel_pages;
5361 kernel_pages = min(end_pfn, usable_startpfn)
5364 kernelcore_remaining -= min(kernel_pages,
5365 kernelcore_remaining);
5366 required_kernelcore -= min(kernel_pages,
5367 required_kernelcore);
5369 /* Continue if range is now fully accounted */
5370 if (end_pfn <= usable_startpfn) {
5373 * Push zone_movable_pfn to the end so
5374 * that if we have to rebalance
5375 * kernelcore across nodes, we will
5376 * not double account here
5378 zone_movable_pfn[nid] = end_pfn;
5381 start_pfn = usable_startpfn;
5385 * The usable PFN range for ZONE_MOVABLE is from
5386 * start_pfn->end_pfn. Calculate size_pages as the
5387 * number of pages used as kernelcore
5389 size_pages = end_pfn - start_pfn;
5390 if (size_pages > kernelcore_remaining)
5391 size_pages = kernelcore_remaining;
5392 zone_movable_pfn[nid] = start_pfn + size_pages;
5395 * Some kernelcore has been met, update counts and
5396 * break if the kernelcore for this node has been
5399 required_kernelcore -= min(required_kernelcore,
5401 kernelcore_remaining -= size_pages;
5402 if (!kernelcore_remaining)
5408 * If there is still required_kernelcore, we do another pass with one
5409 * less node in the count. This will push zone_movable_pfn[nid] further
5410 * along on the nodes that still have memory until kernelcore is
5414 if (usable_nodes && required_kernelcore > usable_nodes)
5418 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5419 for (nid = 0; nid < MAX_NUMNODES; nid++)
5420 zone_movable_pfn[nid] =
5421 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
5424 /* restore the node_state */
5425 node_states[N_MEMORY] = saved_node_state;
5428 /* Any regular or high memory on that node ? */
5429 static void check_for_memory(pg_data_t *pgdat, int nid)
5431 enum zone_type zone_type;
5433 if (N_MEMORY == N_NORMAL_MEMORY)
5436 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
5437 struct zone *zone = &pgdat->node_zones[zone_type];
5438 if (populated_zone(zone)) {
5439 node_set_state(nid, N_HIGH_MEMORY);
5440 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
5441 zone_type <= ZONE_NORMAL)
5442 node_set_state(nid, N_NORMAL_MEMORY);
5449 * free_area_init_nodes - Initialise all pg_data_t and zone data
5450 * @max_zone_pfn: an array of max PFNs for each zone
5452 * This will call free_area_init_node() for each active node in the system.
5453 * Using the page ranges provided by memblock_set_node(), the size of each
5454 * zone in each node and their holes is calculated. If the maximum PFN
5455 * between two adjacent zones match, it is assumed that the zone is empty.
5456 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5457 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5458 * starts where the previous one ended. For example, ZONE_DMA32 starts
5459 * at arch_max_dma_pfn.
5461 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
5463 unsigned long start_pfn, end_pfn;
5466 /* Record where the zone boundaries are */
5467 memset(arch_zone_lowest_possible_pfn, 0,
5468 sizeof(arch_zone_lowest_possible_pfn));
5469 memset(arch_zone_highest_possible_pfn, 0,
5470 sizeof(arch_zone_highest_possible_pfn));
5471 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
5472 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
5473 for (i = 1; i < MAX_NR_ZONES; i++) {
5474 if (i == ZONE_MOVABLE)
5476 arch_zone_lowest_possible_pfn[i] =
5477 arch_zone_highest_possible_pfn[i-1];
5478 arch_zone_highest_possible_pfn[i] =
5479 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
5481 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
5482 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
5484 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5485 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
5486 find_zone_movable_pfns_for_nodes();
5488 /* Print out the zone ranges */
5489 pr_info("Zone ranges:\n");
5490 for (i = 0; i < MAX_NR_ZONES; i++) {
5491 if (i == ZONE_MOVABLE)
5493 pr_info(" %-8s ", zone_names[i]);
5494 if (arch_zone_lowest_possible_pfn[i] ==
5495 arch_zone_highest_possible_pfn[i])
5498 pr_cont("[mem %#018Lx-%#018Lx]\n",
5499 (u64)arch_zone_lowest_possible_pfn[i]
5501 ((u64)arch_zone_highest_possible_pfn[i]
5502 << PAGE_SHIFT) - 1);
5505 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5506 pr_info("Movable zone start for each node\n");
5507 for (i = 0; i < MAX_NUMNODES; i++) {
5508 if (zone_movable_pfn[i])
5509 pr_info(" Node %d: %#018Lx\n", i,
5510 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
5513 /* Print out the early node map */
5514 pr_info("Early memory node ranges\n");
5515 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5516 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
5517 (u64)start_pfn << PAGE_SHIFT,
5518 ((u64)end_pfn << PAGE_SHIFT) - 1);
5520 /* Initialise every node */
5521 mminit_verify_pageflags_layout();
5522 setup_nr_node_ids();
5523 for_each_online_node(nid) {
5524 pg_data_t *pgdat = NODE_DATA(nid);
5525 free_area_init_node(nid, NULL,
5526 find_min_pfn_for_node(nid), NULL);
5528 /* Any memory on that node */
5529 if (pgdat->node_present_pages)
5530 node_set_state(nid, N_MEMORY);
5531 check_for_memory(pgdat, nid);
5535 static int __init cmdline_parse_core(char *p, unsigned long *core)
5537 unsigned long long coremem;
5541 coremem = memparse(p, &p);
5542 *core = coremem >> PAGE_SHIFT;
5544 /* Paranoid check that UL is enough for the coremem value */
5545 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
5551 * kernelcore=size sets the amount of memory for use for allocations that
5552 * cannot be reclaimed or migrated.
5554 static int __init cmdline_parse_kernelcore(char *p)
5556 return cmdline_parse_core(p, &required_kernelcore);
5560 * movablecore=size sets the amount of memory for use for allocations that
5561 * can be reclaimed or migrated.
5563 static int __init cmdline_parse_movablecore(char *p)
5565 return cmdline_parse_core(p, &required_movablecore);
5568 early_param("kernelcore", cmdline_parse_kernelcore);
5569 early_param("movablecore", cmdline_parse_movablecore);
5571 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5573 void adjust_managed_page_count(struct page *page, long count)
5575 spin_lock(&managed_page_count_lock);
5576 page_zone(page)->managed_pages += count;
5577 totalram_pages += count;
5578 #ifdef CONFIG_HIGHMEM
5579 if (PageHighMem(page))
5580 totalhigh_pages += count;
5582 spin_unlock(&managed_page_count_lock);
5584 EXPORT_SYMBOL(adjust_managed_page_count);
5586 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
5589 unsigned long pages = 0;
5591 start = (void *)PAGE_ALIGN((unsigned long)start);
5592 end = (void *)((unsigned long)end & PAGE_MASK);
5593 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
5594 if ((unsigned int)poison <= 0xFF)
5595 memset(pos, poison, PAGE_SIZE);
5596 free_reserved_page(virt_to_page(pos));
5600 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5601 s, pages << (PAGE_SHIFT - 10), start, end);
5605 EXPORT_SYMBOL(free_reserved_area);
5607 #ifdef CONFIG_HIGHMEM
5608 void free_highmem_page(struct page *page)
5610 __free_reserved_page(page);
5612 page_zone(page)->managed_pages++;
5618 void __init mem_init_print_info(const char *str)
5620 unsigned long physpages, codesize, datasize, rosize, bss_size;
5621 unsigned long init_code_size, init_data_size;
5623 physpages = get_num_physpages();
5624 codesize = _etext - _stext;
5625 datasize = _edata - _sdata;
5626 rosize = __end_rodata - __start_rodata;
5627 bss_size = __bss_stop - __bss_start;
5628 init_data_size = __init_end - __init_begin;
5629 init_code_size = _einittext - _sinittext;
5632 * Detect special cases and adjust section sizes accordingly:
5633 * 1) .init.* may be embedded into .data sections
5634 * 2) .init.text.* may be out of [__init_begin, __init_end],
5635 * please refer to arch/tile/kernel/vmlinux.lds.S.
5636 * 3) .rodata.* may be embedded into .text or .data sections.
5638 #define adj_init_size(start, end, size, pos, adj) \
5640 if (start <= pos && pos < end && size > adj) \
5644 adj_init_size(__init_begin, __init_end, init_data_size,
5645 _sinittext, init_code_size);
5646 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
5647 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
5648 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
5649 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
5651 #undef adj_init_size
5653 pr_info("Memory: %luK/%luK available "
5654 "(%luK kernel code, %luK rwdata, %luK rodata, "
5655 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5656 #ifdef CONFIG_HIGHMEM
5660 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
5661 codesize >> 10, datasize >> 10, rosize >> 10,
5662 (init_data_size + init_code_size) >> 10, bss_size >> 10,
5663 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10),
5664 totalcma_pages << (PAGE_SHIFT-10),
5665 #ifdef CONFIG_HIGHMEM
5666 totalhigh_pages << (PAGE_SHIFT-10),
5668 str ? ", " : "", str ? str : "");
5672 * set_dma_reserve - set the specified number of pages reserved in the first zone
5673 * @new_dma_reserve: The number of pages to mark reserved
5675 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5676 * In the DMA zone, a significant percentage may be consumed by kernel image
5677 * and other unfreeable allocations which can skew the watermarks badly. This
5678 * function may optionally be used to account for unfreeable pages in the
5679 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5680 * smaller per-cpu batchsize.
5682 void __init set_dma_reserve(unsigned long new_dma_reserve)
5684 dma_reserve = new_dma_reserve;
5687 void __init free_area_init(unsigned long *zones_size)
5689 free_area_init_node(0, zones_size,
5690 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5693 static int page_alloc_cpu_notify(struct notifier_block *self,
5694 unsigned long action, void *hcpu)
5696 int cpu = (unsigned long)hcpu;
5698 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5699 lru_add_drain_cpu(cpu);
5703 * Spill the event counters of the dead processor
5704 * into the current processors event counters.
5705 * This artificially elevates the count of the current
5708 vm_events_fold_cpu(cpu);
5711 * Zero the differential counters of the dead processor
5712 * so that the vm statistics are consistent.
5714 * This is only okay since the processor is dead and cannot
5715 * race with what we are doing.
5717 cpu_vm_stats_fold(cpu);
5722 void __init page_alloc_init(void)
5724 hotcpu_notifier(page_alloc_cpu_notify, 0);
5728 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5729 * or min_free_kbytes changes.
5731 static void calculate_totalreserve_pages(void)
5733 struct pglist_data *pgdat;
5734 unsigned long reserve_pages = 0;
5735 enum zone_type i, j;
5737 for_each_online_pgdat(pgdat) {
5738 for (i = 0; i < MAX_NR_ZONES; i++) {
5739 struct zone *zone = pgdat->node_zones + i;
5742 /* Find valid and maximum lowmem_reserve in the zone */
5743 for (j = i; j < MAX_NR_ZONES; j++) {
5744 if (zone->lowmem_reserve[j] > max)
5745 max = zone->lowmem_reserve[j];
5748 /* we treat the high watermark as reserved pages. */
5749 max += high_wmark_pages(zone);
5751 if (max > zone->managed_pages)
5752 max = zone->managed_pages;
5753 reserve_pages += max;
5755 * Lowmem reserves are not available to
5756 * GFP_HIGHUSER page cache allocations and
5757 * kswapd tries to balance zones to their high
5758 * watermark. As a result, neither should be
5759 * regarded as dirtyable memory, to prevent a
5760 * situation where reclaim has to clean pages
5761 * in order to balance the zones.
5763 zone->dirty_balance_reserve = max;
5766 dirty_balance_reserve = reserve_pages;
5767 totalreserve_pages = reserve_pages;
5771 * setup_per_zone_lowmem_reserve - called whenever
5772 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5773 * has a correct pages reserved value, so an adequate number of
5774 * pages are left in the zone after a successful __alloc_pages().
5776 static void setup_per_zone_lowmem_reserve(void)
5778 struct pglist_data *pgdat;
5779 enum zone_type j, idx;
5781 for_each_online_pgdat(pgdat) {
5782 for (j = 0; j < MAX_NR_ZONES; j++) {
5783 struct zone *zone = pgdat->node_zones + j;
5784 unsigned long managed_pages = zone->managed_pages;
5786 zone->lowmem_reserve[j] = 0;
5790 struct zone *lower_zone;
5794 if (sysctl_lowmem_reserve_ratio[idx] < 1)
5795 sysctl_lowmem_reserve_ratio[idx] = 1;
5797 lower_zone = pgdat->node_zones + idx;
5798 lower_zone->lowmem_reserve[j] = managed_pages /
5799 sysctl_lowmem_reserve_ratio[idx];
5800 managed_pages += lower_zone->managed_pages;
5805 /* update totalreserve_pages */
5806 calculate_totalreserve_pages();
5809 static void __setup_per_zone_wmarks(void)
5811 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5812 unsigned long lowmem_pages = 0;
5814 unsigned long flags;
5816 /* Calculate total number of !ZONE_HIGHMEM pages */
5817 for_each_zone(zone) {
5818 if (!is_highmem(zone))
5819 lowmem_pages += zone->managed_pages;
5822 for_each_zone(zone) {
5825 spin_lock_irqsave(&zone->lock, flags);
5826 tmp = (u64)pages_min * zone->managed_pages;
5827 do_div(tmp, lowmem_pages);
5828 if (is_highmem(zone)) {
5830 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5831 * need highmem pages, so cap pages_min to a small
5834 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5835 * deltas control asynch page reclaim, and so should
5836 * not be capped for highmem.
5838 unsigned long min_pages;
5840 min_pages = zone->managed_pages / 1024;
5841 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
5842 zone->watermark[WMARK_MIN] = min_pages;
5845 * If it's a lowmem zone, reserve a number of pages
5846 * proportionate to the zone's size.
5848 zone->watermark[WMARK_MIN] = tmp;
5851 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5852 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5854 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
5855 high_wmark_pages(zone) - low_wmark_pages(zone) -
5856 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
5858 setup_zone_migrate_reserve(zone);
5859 spin_unlock_irqrestore(&zone->lock, flags);
5862 /* update totalreserve_pages */
5863 calculate_totalreserve_pages();
5867 * setup_per_zone_wmarks - called when min_free_kbytes changes
5868 * or when memory is hot-{added|removed}
5870 * Ensures that the watermark[min,low,high] values for each zone are set
5871 * correctly with respect to min_free_kbytes.
5873 void setup_per_zone_wmarks(void)
5875 mutex_lock(&zonelists_mutex);
5876 __setup_per_zone_wmarks();
5877 mutex_unlock(&zonelists_mutex);
5881 * The inactive anon list should be small enough that the VM never has to
5882 * do too much work, but large enough that each inactive page has a chance
5883 * to be referenced again before it is swapped out.
5885 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5886 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5887 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5888 * the anonymous pages are kept on the inactive list.
5891 * memory ratio inactive anon
5892 * -------------------------------------
5901 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5903 unsigned int gb, ratio;
5905 /* Zone size in gigabytes */
5906 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
5908 ratio = int_sqrt(10 * gb);
5912 zone->inactive_ratio = ratio;
5915 static void __meminit setup_per_zone_inactive_ratio(void)
5920 calculate_zone_inactive_ratio(zone);
5924 * Initialise min_free_kbytes.
5926 * For small machines we want it small (128k min). For large machines
5927 * we want it large (64MB max). But it is not linear, because network
5928 * bandwidth does not increase linearly with machine size. We use
5930 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5931 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5947 int __meminit init_per_zone_wmark_min(void)
5949 unsigned long lowmem_kbytes;
5950 int new_min_free_kbytes;
5952 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5953 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5955 if (new_min_free_kbytes > user_min_free_kbytes) {
5956 min_free_kbytes = new_min_free_kbytes;
5957 if (min_free_kbytes < 128)
5958 min_free_kbytes = 128;
5959 if (min_free_kbytes > 65536)
5960 min_free_kbytes = 65536;
5962 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5963 new_min_free_kbytes, user_min_free_kbytes);
5965 setup_per_zone_wmarks();
5966 refresh_zone_stat_thresholds();
5967 setup_per_zone_lowmem_reserve();
5968 setup_per_zone_inactive_ratio();
5971 module_init(init_per_zone_wmark_min)
5974 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5975 * that we can call two helper functions whenever min_free_kbytes
5978 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
5979 void __user *buffer, size_t *length, loff_t *ppos)
5983 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5988 user_min_free_kbytes = min_free_kbytes;
5989 setup_per_zone_wmarks();
5995 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
5996 void __user *buffer, size_t *length, loff_t *ppos)
6001 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6006 zone->min_unmapped_pages = (zone->managed_pages *
6007 sysctl_min_unmapped_ratio) / 100;
6011 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6012 void __user *buffer, size_t *length, loff_t *ppos)
6017 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6022 zone->min_slab_pages = (zone->managed_pages *
6023 sysctl_min_slab_ratio) / 100;
6029 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6030 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6031 * whenever sysctl_lowmem_reserve_ratio changes.
6033 * The reserve ratio obviously has absolutely no relation with the
6034 * minimum watermarks. The lowmem reserve ratio can only make sense
6035 * if in function of the boot time zone sizes.
6037 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6038 void __user *buffer, size_t *length, loff_t *ppos)
6040 proc_dointvec_minmax(table, write, buffer, length, ppos);
6041 setup_per_zone_lowmem_reserve();
6046 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6047 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6048 * pagelist can have before it gets flushed back to buddy allocator.
6050 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6051 void __user *buffer, size_t *length, loff_t *ppos)
6054 int old_percpu_pagelist_fraction;
6057 mutex_lock(&pcp_batch_high_lock);
6058 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6060 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6061 if (!write || ret < 0)
6064 /* Sanity checking to avoid pcp imbalance */
6065 if (percpu_pagelist_fraction &&
6066 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6067 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6073 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6076 for_each_populated_zone(zone) {
6079 for_each_possible_cpu(cpu)
6080 pageset_set_high_and_batch(zone,
6081 per_cpu_ptr(zone->pageset, cpu));
6084 mutex_unlock(&pcp_batch_high_lock);
6089 int hashdist = HASHDIST_DEFAULT;
6091 static int __init set_hashdist(char *str)
6095 hashdist = simple_strtoul(str, &str, 0);
6098 __setup("hashdist=", set_hashdist);
6102 * allocate a large system hash table from bootmem
6103 * - it is assumed that the hash table must contain an exact power-of-2
6104 * quantity of entries
6105 * - limit is the number of hash buckets, not the total allocation size
6107 void *__init alloc_large_system_hash(const char *tablename,
6108 unsigned long bucketsize,
6109 unsigned long numentries,
6112 unsigned int *_hash_shift,
6113 unsigned int *_hash_mask,
6114 unsigned long low_limit,
6115 unsigned long high_limit)
6117 unsigned long long max = high_limit;
6118 unsigned long log2qty, size;
6121 /* allow the kernel cmdline to have a say */
6123 /* round applicable memory size up to nearest megabyte */
6124 numentries = nr_kernel_pages;
6126 /* It isn't necessary when PAGE_SIZE >= 1MB */
6127 if (PAGE_SHIFT < 20)
6128 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6130 /* limit to 1 bucket per 2^scale bytes of low memory */
6131 if (scale > PAGE_SHIFT)
6132 numentries >>= (scale - PAGE_SHIFT);
6134 numentries <<= (PAGE_SHIFT - scale);
6136 /* Make sure we've got at least a 0-order allocation.. */
6137 if (unlikely(flags & HASH_SMALL)) {
6138 /* Makes no sense without HASH_EARLY */
6139 WARN_ON(!(flags & HASH_EARLY));
6140 if (!(numentries >> *_hash_shift)) {
6141 numentries = 1UL << *_hash_shift;
6142 BUG_ON(!numentries);
6144 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6145 numentries = PAGE_SIZE / bucketsize;
6147 numentries = roundup_pow_of_two(numentries);
6149 /* limit allocation size to 1/16 total memory by default */
6151 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6152 do_div(max, bucketsize);
6154 max = min(max, 0x80000000ULL);
6156 if (numentries < low_limit)
6157 numentries = low_limit;
6158 if (numentries > max)
6161 log2qty = ilog2(numentries);
6164 size = bucketsize << log2qty;
6165 if (flags & HASH_EARLY)
6166 table = memblock_virt_alloc_nopanic(size, 0);
6168 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6171 * If bucketsize is not a power-of-two, we may free
6172 * some pages at the end of hash table which
6173 * alloc_pages_exact() automatically does
6175 if (get_order(size) < MAX_ORDER) {
6176 table = alloc_pages_exact(size, GFP_ATOMIC);
6177 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6180 } while (!table && size > PAGE_SIZE && --log2qty);
6183 panic("Failed to allocate %s hash table\n", tablename);
6185 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
6188 ilog2(size) - PAGE_SHIFT,
6192 *_hash_shift = log2qty;
6194 *_hash_mask = (1 << log2qty) - 1;
6199 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6200 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
6203 #ifdef CONFIG_SPARSEMEM
6204 return __pfn_to_section(pfn)->pageblock_flags;
6206 return zone->pageblock_flags;
6207 #endif /* CONFIG_SPARSEMEM */
6210 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
6212 #ifdef CONFIG_SPARSEMEM
6213 pfn &= (PAGES_PER_SECTION-1);
6214 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6216 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
6217 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
6218 #endif /* CONFIG_SPARSEMEM */
6222 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6223 * @page: The page within the block of interest
6224 * @pfn: The target page frame number
6225 * @end_bitidx: The last bit of interest to retrieve
6226 * @mask: mask of bits that the caller is interested in
6228 * Return: pageblock_bits flags
6230 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
6231 unsigned long end_bitidx,
6235 unsigned long *bitmap;
6236 unsigned long bitidx, word_bitidx;
6239 zone = page_zone(page);
6240 bitmap = get_pageblock_bitmap(zone, pfn);
6241 bitidx = pfn_to_bitidx(zone, pfn);
6242 word_bitidx = bitidx / BITS_PER_LONG;
6243 bitidx &= (BITS_PER_LONG-1);
6245 word = bitmap[word_bitidx];
6246 bitidx += end_bitidx;
6247 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
6251 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6252 * @page: The page within the block of interest
6253 * @flags: The flags to set
6254 * @pfn: The target page frame number
6255 * @end_bitidx: The last bit of interest
6256 * @mask: mask of bits that the caller is interested in
6258 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
6260 unsigned long end_bitidx,
6264 unsigned long *bitmap;
6265 unsigned long bitidx, word_bitidx;
6266 unsigned long old_word, word;
6268 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
6270 zone = page_zone(page);
6271 bitmap = get_pageblock_bitmap(zone, pfn);
6272 bitidx = pfn_to_bitidx(zone, pfn);
6273 word_bitidx = bitidx / BITS_PER_LONG;
6274 bitidx &= (BITS_PER_LONG-1);
6276 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page);
6278 bitidx += end_bitidx;
6279 mask <<= (BITS_PER_LONG - bitidx - 1);
6280 flags <<= (BITS_PER_LONG - bitidx - 1);
6282 word = READ_ONCE(bitmap[word_bitidx]);
6284 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
6285 if (word == old_word)
6292 * This function checks whether pageblock includes unmovable pages or not.
6293 * If @count is not zero, it is okay to include less @count unmovable pages
6295 * PageLRU check without isolation or lru_lock could race so that
6296 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6297 * expect this function should be exact.
6299 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6300 bool skip_hwpoisoned_pages)
6302 unsigned long pfn, iter, found;
6306 * For avoiding noise data, lru_add_drain_all() should be called
6307 * If ZONE_MOVABLE, the zone never contains unmovable pages
6309 if (zone_idx(zone) == ZONE_MOVABLE)
6311 mt = get_pageblock_migratetype(page);
6312 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
6315 pfn = page_to_pfn(page);
6316 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
6317 unsigned long check = pfn + iter;
6319 if (!pfn_valid_within(check))
6322 page = pfn_to_page(check);
6325 * Hugepages are not in LRU lists, but they're movable.
6326 * We need not scan over tail pages bacause we don't
6327 * handle each tail page individually in migration.
6329 if (PageHuge(page)) {
6330 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
6335 * We can't use page_count without pin a page
6336 * because another CPU can free compound page.
6337 * This check already skips compound tails of THP
6338 * because their page->_count is zero at all time.
6340 if (!atomic_read(&page->_count)) {
6341 if (PageBuddy(page))
6342 iter += (1 << page_order(page)) - 1;
6347 * The HWPoisoned page may be not in buddy system, and
6348 * page_count() is not 0.
6350 if (skip_hwpoisoned_pages && PageHWPoison(page))
6356 * If there are RECLAIMABLE pages, we need to check
6357 * it. But now, memory offline itself doesn't call
6358 * shrink_node_slabs() and it still to be fixed.
6361 * If the page is not RAM, page_count()should be 0.
6362 * we don't need more check. This is an _used_ not-movable page.
6364 * The problematic thing here is PG_reserved pages. PG_reserved
6365 * is set to both of a memory hole page and a _used_ kernel
6374 bool is_pageblock_removable_nolock(struct page *page)
6380 * We have to be careful here because we are iterating over memory
6381 * sections which are not zone aware so we might end up outside of
6382 * the zone but still within the section.
6383 * We have to take care about the node as well. If the node is offline
6384 * its NODE_DATA will be NULL - see page_zone.
6386 if (!node_online(page_to_nid(page)))
6389 zone = page_zone(page);
6390 pfn = page_to_pfn(page);
6391 if (!zone_spans_pfn(zone, pfn))
6394 return !has_unmovable_pages(zone, page, 0, true);
6399 static unsigned long pfn_max_align_down(unsigned long pfn)
6401 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
6402 pageblock_nr_pages) - 1);
6405 static unsigned long pfn_max_align_up(unsigned long pfn)
6407 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
6408 pageblock_nr_pages));
6411 /* [start, end) must belong to a single zone. */
6412 static int __alloc_contig_migrate_range(struct compact_control *cc,
6413 unsigned long start, unsigned long end)
6415 /* This function is based on compact_zone() from compaction.c. */
6416 unsigned long nr_reclaimed;
6417 unsigned long pfn = start;
6418 unsigned int tries = 0;
6423 while (pfn < end || !list_empty(&cc->migratepages)) {
6424 if (fatal_signal_pending(current)) {
6429 if (list_empty(&cc->migratepages)) {
6430 cc->nr_migratepages = 0;
6431 pfn = isolate_migratepages_range(cc, pfn, end);
6437 } else if (++tries == 5) {
6438 ret = ret < 0 ? ret : -EBUSY;
6442 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
6444 cc->nr_migratepages -= nr_reclaimed;
6446 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
6447 NULL, 0, cc->mode, MR_CMA);
6450 putback_movable_pages(&cc->migratepages);
6457 * alloc_contig_range() -- tries to allocate given range of pages
6458 * @start: start PFN to allocate
6459 * @end: one-past-the-last PFN to allocate
6460 * @migratetype: migratetype of the underlaying pageblocks (either
6461 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6462 * in range must have the same migratetype and it must
6463 * be either of the two.
6465 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6466 * aligned, however it's the caller's responsibility to guarantee that
6467 * we are the only thread that changes migrate type of pageblocks the
6470 * The PFN range must belong to a single zone.
6472 * Returns zero on success or negative error code. On success all
6473 * pages which PFN is in [start, end) are allocated for the caller and
6474 * need to be freed with free_contig_range().
6476 int alloc_contig_range(unsigned long start, unsigned long end,
6477 unsigned migratetype)
6479 unsigned long outer_start, outer_end;
6482 struct compact_control cc = {
6483 .nr_migratepages = 0,
6485 .zone = page_zone(pfn_to_page(start)),
6486 .mode = MIGRATE_SYNC,
6487 .ignore_skip_hint = true,
6489 INIT_LIST_HEAD(&cc.migratepages);
6492 * What we do here is we mark all pageblocks in range as
6493 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6494 * have different sizes, and due to the way page allocator
6495 * work, we align the range to biggest of the two pages so
6496 * that page allocator won't try to merge buddies from
6497 * different pageblocks and change MIGRATE_ISOLATE to some
6498 * other migration type.
6500 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6501 * migrate the pages from an unaligned range (ie. pages that
6502 * we are interested in). This will put all the pages in
6503 * range back to page allocator as MIGRATE_ISOLATE.
6505 * When this is done, we take the pages in range from page
6506 * allocator removing them from the buddy system. This way
6507 * page allocator will never consider using them.
6509 * This lets us mark the pageblocks back as
6510 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6511 * aligned range but not in the unaligned, original range are
6512 * put back to page allocator so that buddy can use them.
6515 ret = start_isolate_page_range(pfn_max_align_down(start),
6516 pfn_max_align_up(end), migratetype,
6521 ret = __alloc_contig_migrate_range(&cc, start, end);
6526 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6527 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6528 * more, all pages in [start, end) are free in page allocator.
6529 * What we are going to do is to allocate all pages from
6530 * [start, end) (that is remove them from page allocator).
6532 * The only problem is that pages at the beginning and at the
6533 * end of interesting range may be not aligned with pages that
6534 * page allocator holds, ie. they can be part of higher order
6535 * pages. Because of this, we reserve the bigger range and
6536 * once this is done free the pages we are not interested in.
6538 * We don't have to hold zone->lock here because the pages are
6539 * isolated thus they won't get removed from buddy.
6542 lru_add_drain_all();
6543 drain_all_pages(cc.zone);
6546 outer_start = start;
6547 while (!PageBuddy(pfn_to_page(outer_start))) {
6548 if (++order >= MAX_ORDER) {
6552 outer_start &= ~0UL << order;
6555 /* Make sure the range is really isolated. */
6556 if (test_pages_isolated(outer_start, end, false)) {
6557 pr_info("%s: [%lx, %lx) PFNs busy\n",
6558 __func__, outer_start, end);
6563 /* Grab isolated pages from freelists. */
6564 outer_end = isolate_freepages_range(&cc, outer_start, end);
6570 /* Free head and tail (if any) */
6571 if (start != outer_start)
6572 free_contig_range(outer_start, start - outer_start);
6573 if (end != outer_end)
6574 free_contig_range(end, outer_end - end);
6577 undo_isolate_page_range(pfn_max_align_down(start),
6578 pfn_max_align_up(end), migratetype);
6582 void free_contig_range(unsigned long pfn, unsigned nr_pages)
6584 unsigned int count = 0;
6586 for (; nr_pages--; pfn++) {
6587 struct page *page = pfn_to_page(pfn);
6589 count += page_count(page) != 1;
6592 WARN(count != 0, "%d pages are still in use!\n", count);
6596 #ifdef CONFIG_MEMORY_HOTPLUG
6598 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6599 * page high values need to be recalulated.
6601 void __meminit zone_pcp_update(struct zone *zone)
6604 mutex_lock(&pcp_batch_high_lock);
6605 for_each_possible_cpu(cpu)
6606 pageset_set_high_and_batch(zone,
6607 per_cpu_ptr(zone->pageset, cpu));
6608 mutex_unlock(&pcp_batch_high_lock);
6612 void zone_pcp_reset(struct zone *zone)
6614 unsigned long flags;
6616 struct per_cpu_pageset *pset;
6618 /* avoid races with drain_pages() */
6619 local_irq_save(flags);
6620 if (zone->pageset != &boot_pageset) {
6621 for_each_online_cpu(cpu) {
6622 pset = per_cpu_ptr(zone->pageset, cpu);
6623 drain_zonestat(zone, pset);
6625 free_percpu(zone->pageset);
6626 zone->pageset = &boot_pageset;
6628 local_irq_restore(flags);
6631 #ifdef CONFIG_MEMORY_HOTREMOVE
6633 * All pages in the range must be isolated before calling this.
6636 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
6640 unsigned int order, i;
6642 unsigned long flags;
6643 /* find the first valid pfn */
6644 for (pfn = start_pfn; pfn < end_pfn; pfn++)
6649 zone = page_zone(pfn_to_page(pfn));
6650 spin_lock_irqsave(&zone->lock, flags);
6652 while (pfn < end_pfn) {
6653 if (!pfn_valid(pfn)) {
6657 page = pfn_to_page(pfn);
6659 * The HWPoisoned page may be not in buddy system, and
6660 * page_count() is not 0.
6662 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
6664 SetPageReserved(page);
6668 BUG_ON(page_count(page));
6669 BUG_ON(!PageBuddy(page));
6670 order = page_order(page);
6671 #ifdef CONFIG_DEBUG_VM
6672 printk(KERN_INFO "remove from free list %lx %d %lx\n",
6673 pfn, 1 << order, end_pfn);
6675 list_del(&page->lru);
6676 rmv_page_order(page);
6677 zone->free_area[order].nr_free--;
6678 for (i = 0; i < (1 << order); i++)
6679 SetPageReserved((page+i));
6680 pfn += (1 << order);
6682 spin_unlock_irqrestore(&zone->lock, flags);
6686 #ifdef CONFIG_MEMORY_FAILURE
6687 bool is_free_buddy_page(struct page *page)
6689 struct zone *zone = page_zone(page);
6690 unsigned long pfn = page_to_pfn(page);
6691 unsigned long flags;
6694 spin_lock_irqsave(&zone->lock, flags);
6695 for (order = 0; order < MAX_ORDER; order++) {
6696 struct page *page_head = page - (pfn & ((1 << order) - 1));
6698 if (PageBuddy(page_head) && page_order(page_head) >= order)
6701 spin_unlock_irqrestore(&zone->lock, flags);
6703 return order < MAX_ORDER;