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>
64 #include <linux/kthread.h>
66 #include <asm/sections.h>
67 #include <asm/tlbflush.h>
68 #include <asm/div64.h>
71 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
72 static DEFINE_MUTEX(pcp_batch_high_lock
);
73 #define MIN_PERCPU_PAGELIST_FRACTION (8)
75 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
76 DEFINE_PER_CPU(int, numa_node
);
77 EXPORT_PER_CPU_SYMBOL(numa_node
);
80 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
82 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
83 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
84 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
85 * defined in <linux/topology.h>.
87 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
88 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
89 int _node_numa_mem_
[MAX_NUMNODES
];
93 * Array of node states.
95 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
96 [N_POSSIBLE
] = NODE_MASK_ALL
,
97 [N_ONLINE
] = { { [0] = 1UL } },
99 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
100 #ifdef CONFIG_HIGHMEM
101 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
103 #ifdef CONFIG_MOVABLE_NODE
104 [N_MEMORY
] = { { [0] = 1UL } },
106 [N_CPU
] = { { [0] = 1UL } },
109 EXPORT_SYMBOL(node_states
);
111 /* Protect totalram_pages and zone->managed_pages */
112 static DEFINE_SPINLOCK(managed_page_count_lock
);
114 unsigned long totalram_pages __read_mostly
;
115 unsigned long totalreserve_pages __read_mostly
;
116 unsigned long totalcma_pages __read_mostly
;
118 * When calculating the number of globally allowed dirty pages, there
119 * is a certain number of per-zone reserves that should not be
120 * considered dirtyable memory. This is the sum of those reserves
121 * over all existing zones that contribute dirtyable memory.
123 unsigned long dirty_balance_reserve __read_mostly
;
125 int percpu_pagelist_fraction
;
126 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
129 * A cached value of the page's pageblock's migratetype, used when the page is
130 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
131 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
132 * Also the migratetype set in the page does not necessarily match the pcplist
133 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
134 * other index - this ensures that it will be put on the correct CMA freelist.
136 static inline int get_pcppage_migratetype(struct page
*page
)
141 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
143 page
->index
= migratetype
;
146 #ifdef CONFIG_PM_SLEEP
148 * The following functions are used by the suspend/hibernate code to temporarily
149 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
150 * while devices are suspended. To avoid races with the suspend/hibernate code,
151 * they should always be called with pm_mutex held (gfp_allowed_mask also should
152 * only be modified with pm_mutex held, unless the suspend/hibernate code is
153 * guaranteed not to run in parallel with that modification).
156 static gfp_t saved_gfp_mask
;
158 void pm_restore_gfp_mask(void)
160 WARN_ON(!mutex_is_locked(&pm_mutex
));
161 if (saved_gfp_mask
) {
162 gfp_allowed_mask
= saved_gfp_mask
;
167 void pm_restrict_gfp_mask(void)
169 WARN_ON(!mutex_is_locked(&pm_mutex
));
170 WARN_ON(saved_gfp_mask
);
171 saved_gfp_mask
= gfp_allowed_mask
;
172 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
175 bool pm_suspended_storage(void)
177 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
181 #endif /* CONFIG_PM_SLEEP */
183 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
184 unsigned int pageblock_order __read_mostly
;
187 static void __free_pages_ok(struct page
*page
, unsigned int order
);
190 * results with 256, 32 in the lowmem_reserve sysctl:
191 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
192 * 1G machine -> (16M dma, 784M normal, 224M high)
193 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
194 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
195 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
197 * TBD: should special case ZONE_DMA32 machines here - in those we normally
198 * don't need any ZONE_NORMAL reservation
200 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
201 #ifdef CONFIG_ZONE_DMA
204 #ifdef CONFIG_ZONE_DMA32
207 #ifdef CONFIG_HIGHMEM
213 EXPORT_SYMBOL(totalram_pages
);
215 static char * const zone_names
[MAX_NR_ZONES
] = {
216 #ifdef CONFIG_ZONE_DMA
219 #ifdef CONFIG_ZONE_DMA32
223 #ifdef CONFIG_HIGHMEM
227 #ifdef CONFIG_ZONE_DEVICE
232 static void free_compound_page(struct page
*page
);
233 compound_page_dtor
* const compound_page_dtors
[] = {
236 #ifdef CONFIG_HUGETLB_PAGE
242 * Try to keep at least this much lowmem free. Do not allow normal
243 * allocations below this point, only high priority ones. Automatically
244 * tuned according to the amount of memory in the system.
246 int min_free_kbytes
= 1024;
247 int user_min_free_kbytes
= -1;
250 * Extra memory for the system to try freeing. Used to temporarily
251 * free memory, to make space for new workloads. Anyone can allocate
252 * down to the min watermarks controlled by min_free_kbytes above.
254 int extra_free_kbytes
= 0;
256 static unsigned long __meminitdata nr_kernel_pages
;
257 static unsigned long __meminitdata nr_all_pages
;
258 static unsigned long __meminitdata dma_reserve
;
260 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
261 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
262 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
263 static unsigned long __initdata required_kernelcore
;
264 static unsigned long __initdata required_movablecore
;
265 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
267 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
269 EXPORT_SYMBOL(movable_zone
);
270 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
273 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
274 int nr_online_nodes __read_mostly
= 1;
275 EXPORT_SYMBOL(nr_node_ids
);
276 EXPORT_SYMBOL(nr_online_nodes
);
279 int page_group_by_mobility_disabled __read_mostly
;
281 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
282 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
284 pgdat
->first_deferred_pfn
= ULONG_MAX
;
287 /* Returns true if the struct page for the pfn is uninitialised */
288 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
290 int nid
= early_pfn_to_nid(pfn
);
292 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
298 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
300 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
307 * Returns false when the remaining initialisation should be deferred until
308 * later in the boot cycle when it can be parallelised.
310 static inline bool update_defer_init(pg_data_t
*pgdat
,
311 unsigned long pfn
, unsigned long zone_end
,
312 unsigned long *nr_initialised
)
314 /* Always populate low zones for address-contrained allocations */
315 if (zone_end
< pgdat_end_pfn(pgdat
))
318 /* Initialise at least 2G of the highest zone */
320 if (*nr_initialised
> (2UL << (30 - PAGE_SHIFT
)) &&
321 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
322 pgdat
->first_deferred_pfn
= pfn
;
329 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
333 static inline bool early_page_uninitialised(unsigned long pfn
)
338 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
343 static inline bool update_defer_init(pg_data_t
*pgdat
,
344 unsigned long pfn
, unsigned long zone_end
,
345 unsigned long *nr_initialised
)
352 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
354 if (unlikely(page_group_by_mobility_disabled
&&
355 migratetype
< MIGRATE_PCPTYPES
))
356 migratetype
= MIGRATE_UNMOVABLE
;
358 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
359 PB_migrate
, PB_migrate_end
);
362 #ifdef CONFIG_DEBUG_VM
363 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
367 unsigned long pfn
= page_to_pfn(page
);
368 unsigned long sp
, start_pfn
;
371 seq
= zone_span_seqbegin(zone
);
372 start_pfn
= zone
->zone_start_pfn
;
373 sp
= zone
->spanned_pages
;
374 if (!zone_spans_pfn(zone
, pfn
))
376 } while (zone_span_seqretry(zone
, seq
));
379 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
380 pfn
, zone_to_nid(zone
), zone
->name
,
381 start_pfn
, start_pfn
+ sp
);
386 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
388 if (!pfn_valid_within(page_to_pfn(page
)))
390 if (zone
!= page_zone(page
))
396 * Temporary debugging check for pages not lying within a given zone.
398 static int bad_range(struct zone
*zone
, struct page
*page
)
400 if (page_outside_zone_boundaries(zone
, page
))
402 if (!page_is_consistent(zone
, page
))
408 static inline int bad_range(struct zone
*zone
, struct page
*page
)
414 static void bad_page(struct page
*page
, const char *reason
,
415 unsigned long bad_flags
)
417 static unsigned long resume
;
418 static unsigned long nr_shown
;
419 static unsigned long nr_unshown
;
421 /* Don't complain about poisoned pages */
422 if (PageHWPoison(page
)) {
423 page_mapcount_reset(page
); /* remove PageBuddy */
428 * Allow a burst of 60 reports, then keep quiet for that minute;
429 * or allow a steady drip of one report per second.
431 if (nr_shown
== 60) {
432 if (time_before(jiffies
, resume
)) {
438 "BUG: Bad page state: %lu messages suppressed\n",
445 resume
= jiffies
+ 60 * HZ
;
447 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
448 current
->comm
, page_to_pfn(page
));
449 dump_page_badflags(page
, reason
, bad_flags
);
454 /* Leave bad fields for debug, except PageBuddy could make trouble */
455 page_mapcount_reset(page
); /* remove PageBuddy */
456 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
460 * Higher-order pages are called "compound pages". They are structured thusly:
462 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
464 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
465 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
467 * The first tail page's ->compound_dtor holds the offset in array of compound
468 * page destructors. See compound_page_dtors.
470 * The first tail page's ->compound_order holds the order of allocation.
471 * This usage means that zero-order pages may not be compound.
474 static void free_compound_page(struct page
*page
)
476 __free_pages_ok(page
, compound_order(page
));
479 void prep_compound_page(struct page
*page
, unsigned int order
)
482 int nr_pages
= 1 << order
;
484 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
485 set_compound_order(page
, order
);
487 for (i
= 1; i
< nr_pages
; i
++) {
488 struct page
*p
= page
+ i
;
489 set_page_count(p
, 0);
490 set_compound_head(p
, page
);
494 #ifdef CONFIG_DEBUG_PAGEALLOC
495 unsigned int _debug_guardpage_minorder
;
496 bool _debug_pagealloc_enabled __read_mostly
;
497 bool _debug_guardpage_enabled __read_mostly
;
499 static int __init
early_debug_pagealloc(char *buf
)
504 if (strcmp(buf
, "on") == 0)
505 _debug_pagealloc_enabled
= true;
509 early_param("debug_pagealloc", early_debug_pagealloc
);
511 static bool need_debug_guardpage(void)
513 /* If we don't use debug_pagealloc, we don't need guard page */
514 if (!debug_pagealloc_enabled())
520 static void init_debug_guardpage(void)
522 if (!debug_pagealloc_enabled())
525 _debug_guardpage_enabled
= true;
528 struct page_ext_operations debug_guardpage_ops
= {
529 .need
= need_debug_guardpage
,
530 .init
= init_debug_guardpage
,
533 static int __init
debug_guardpage_minorder_setup(char *buf
)
537 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
538 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
541 _debug_guardpage_minorder
= res
;
542 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
545 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
547 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
548 unsigned int order
, int migratetype
)
550 struct page_ext
*page_ext
;
552 if (!debug_guardpage_enabled())
555 page_ext
= lookup_page_ext(page
);
556 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
558 INIT_LIST_HEAD(&page
->lru
);
559 set_page_private(page
, order
);
560 /* Guard pages are not available for any usage */
561 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
564 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
565 unsigned int order
, int migratetype
)
567 struct page_ext
*page_ext
;
569 if (!debug_guardpage_enabled())
572 page_ext
= lookup_page_ext(page
);
573 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
575 set_page_private(page
, 0);
576 if (!is_migrate_isolate(migratetype
))
577 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
580 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
581 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
582 unsigned int order
, int migratetype
) {}
583 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
584 unsigned int order
, int migratetype
) {}
587 static inline void set_page_order(struct page
*page
, unsigned int order
)
589 set_page_private(page
, order
);
590 __SetPageBuddy(page
);
593 static inline void rmv_page_order(struct page
*page
)
595 __ClearPageBuddy(page
);
596 set_page_private(page
, 0);
600 * This function checks whether a page is free && is the buddy
601 * we can do coalesce a page and its buddy if
602 * (a) the buddy is not in a hole &&
603 * (b) the buddy is in the buddy system &&
604 * (c) a page and its buddy have the same order &&
605 * (d) a page and its buddy are in the same zone.
607 * For recording whether a page is in the buddy system, we set ->_mapcount
608 * PAGE_BUDDY_MAPCOUNT_VALUE.
609 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
610 * serialized by zone->lock.
612 * For recording page's order, we use page_private(page).
614 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
617 if (!pfn_valid_within(page_to_pfn(buddy
)))
620 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
621 if (page_zone_id(page
) != page_zone_id(buddy
))
624 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
629 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
631 * zone check is done late to avoid uselessly
632 * calculating zone/node ids for pages that could
635 if (page_zone_id(page
) != page_zone_id(buddy
))
638 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
646 * Freeing function for a buddy system allocator.
648 * The concept of a buddy system is to maintain direct-mapped table
649 * (containing bit values) for memory blocks of various "orders".
650 * The bottom level table contains the map for the smallest allocatable
651 * units of memory (here, pages), and each level above it describes
652 * pairs of units from the levels below, hence, "buddies".
653 * At a high level, all that happens here is marking the table entry
654 * at the bottom level available, and propagating the changes upward
655 * as necessary, plus some accounting needed to play nicely with other
656 * parts of the VM system.
657 * At each level, we keep a list of pages, which are heads of continuous
658 * free pages of length of (1 << order) and marked with _mapcount
659 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
661 * So when we are allocating or freeing one, we can derive the state of the
662 * other. That is, if we allocate a small block, and both were
663 * free, the remainder of the region must be split into blocks.
664 * If a block is freed, and its buddy is also free, then this
665 * triggers coalescing into a block of larger size.
670 static inline void __free_one_page(struct page
*page
,
672 struct zone
*zone
, unsigned int order
,
675 unsigned long page_idx
;
676 unsigned long combined_idx
;
677 unsigned long uninitialized_var(buddy_idx
);
679 unsigned int max_order
;
681 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
683 VM_BUG_ON(!zone_is_initialized(zone
));
684 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
686 VM_BUG_ON(migratetype
== -1);
687 if (likely(!is_migrate_isolate(migratetype
)))
688 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
690 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
692 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
693 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
696 while (order
< max_order
- 1) {
697 buddy_idx
= __find_buddy_index(page_idx
, order
);
698 buddy
= page
+ (buddy_idx
- page_idx
);
699 if (!page_is_buddy(page
, buddy
, order
))
702 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
703 * merge with it and move up one order.
705 if (page_is_guard(buddy
)) {
706 clear_page_guard(zone
, buddy
, order
, migratetype
);
708 list_del(&buddy
->lru
);
709 zone
->free_area
[order
].nr_free
--;
710 rmv_page_order(buddy
);
712 combined_idx
= buddy_idx
& page_idx
;
713 page
= page
+ (combined_idx
- page_idx
);
714 page_idx
= combined_idx
;
717 if (max_order
< MAX_ORDER
) {
718 /* If we are here, it means order is >= pageblock_order.
719 * We want to prevent merge between freepages on isolate
720 * pageblock and normal pageblock. Without this, pageblock
721 * isolation could cause incorrect freepage or CMA accounting.
723 * We don't want to hit this code for the more frequent
726 if (unlikely(has_isolate_pageblock(zone
))) {
729 buddy_idx
= __find_buddy_index(page_idx
, order
);
730 buddy
= page
+ (buddy_idx
- page_idx
);
731 buddy_mt
= get_pageblock_migratetype(buddy
);
733 if (migratetype
!= buddy_mt
734 && (is_migrate_isolate(migratetype
) ||
735 is_migrate_isolate(buddy_mt
)))
739 goto continue_merging
;
743 set_page_order(page
, order
);
746 * If this is not the largest possible page, check if the buddy
747 * of the next-highest order is free. If it is, it's possible
748 * that pages are being freed that will coalesce soon. In case,
749 * that is happening, add the free page to the tail of the list
750 * so it's less likely to be used soon and more likely to be merged
751 * as a higher order page
753 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
754 struct page
*higher_page
, *higher_buddy
;
755 combined_idx
= buddy_idx
& page_idx
;
756 higher_page
= page
+ (combined_idx
- page_idx
);
757 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
758 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
759 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
760 list_add_tail(&page
->lru
,
761 &zone
->free_area
[order
].free_list
[migratetype
]);
766 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
768 zone
->free_area
[order
].nr_free
++;
771 static inline int free_pages_check(struct page
*page
)
773 const char *bad_reason
= NULL
;
774 unsigned long bad_flags
= 0;
776 if (unlikely(page_mapcount(page
)))
777 bad_reason
= "nonzero mapcount";
778 if (unlikely(page
->mapping
!= NULL
))
779 bad_reason
= "non-NULL mapping";
780 if (unlikely(atomic_read(&page
->_count
) != 0))
781 bad_reason
= "nonzero _count";
782 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
783 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
784 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
787 if (unlikely(page
->mem_cgroup
))
788 bad_reason
= "page still charged to cgroup";
790 if (unlikely(bad_reason
)) {
791 bad_page(page
, bad_reason
, bad_flags
);
794 page_cpupid_reset_last(page
);
795 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
796 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
801 * Frees a number of pages from the PCP lists
802 * Assumes all pages on list are in same zone, and of same order.
803 * count is the number of pages to free.
805 * If the zone was previously in an "all pages pinned" state then look to
806 * see if this freeing clears that state.
808 * And clear the zone's pages_scanned counter, to hold off the "all pages are
809 * pinned" detection logic.
811 static void free_pcppages_bulk(struct zone
*zone
, int count
,
812 struct per_cpu_pages
*pcp
)
817 unsigned long nr_scanned
;
819 spin_lock(&zone
->lock
);
820 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
822 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
826 struct list_head
*list
;
829 * Remove pages from lists in a round-robin fashion. A
830 * batch_free count is maintained that is incremented when an
831 * empty list is encountered. This is so more pages are freed
832 * off fuller lists instead of spinning excessively around empty
837 if (++migratetype
== MIGRATE_PCPTYPES
)
839 list
= &pcp
->lists
[migratetype
];
840 } while (list_empty(list
));
842 /* This is the only non-empty list. Free them all. */
843 if (batch_free
== MIGRATE_PCPTYPES
)
844 batch_free
= to_free
;
847 int mt
; /* migratetype of the to-be-freed page */
849 page
= list_entry(list
->prev
, struct page
, lru
);
850 /* must delete as __free_one_page list manipulates */
851 list_del(&page
->lru
);
853 mt
= get_pcppage_migratetype(page
);
854 /* MIGRATE_ISOLATE page should not go to pcplists */
855 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
856 /* Pageblock could have been isolated meanwhile */
857 if (unlikely(has_isolate_pageblock(zone
)))
858 mt
= get_pageblock_migratetype(page
);
860 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
861 trace_mm_page_pcpu_drain(page
, 0, mt
);
862 } while (--to_free
&& --batch_free
&& !list_empty(list
));
864 spin_unlock(&zone
->lock
);
867 static void free_one_page(struct zone
*zone
,
868 struct page
*page
, unsigned long pfn
,
872 unsigned long nr_scanned
;
873 spin_lock(&zone
->lock
);
874 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
876 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
878 if (unlikely(has_isolate_pageblock(zone
) ||
879 is_migrate_isolate(migratetype
))) {
880 migratetype
= get_pfnblock_migratetype(page
, pfn
);
882 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
883 spin_unlock(&zone
->lock
);
886 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
891 * We rely page->lru.next never has bit 0 set, unless the page
892 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
894 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
896 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
900 if (unlikely(!PageTail(page
))) {
901 bad_page(page
, "PageTail not set", 0);
904 if (unlikely(compound_head(page
) != head_page
)) {
905 bad_page(page
, "compound_head not consistent", 0);
910 clear_compound_head(page
);
914 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
915 unsigned long zone
, int nid
)
917 set_page_links(page
, zone
, nid
, pfn
);
918 init_page_count(page
);
919 page_mapcount_reset(page
);
920 page_cpupid_reset_last(page
);
922 INIT_LIST_HEAD(&page
->lru
);
923 #ifdef WANT_PAGE_VIRTUAL
924 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
925 if (!is_highmem_idx(zone
))
926 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
930 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
933 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
936 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
937 static void init_reserved_page(unsigned long pfn
)
942 if (!early_page_uninitialised(pfn
))
945 nid
= early_pfn_to_nid(pfn
);
946 pgdat
= NODE_DATA(nid
);
948 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
949 struct zone
*zone
= &pgdat
->node_zones
[zid
];
951 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
954 __init_single_pfn(pfn
, zid
, nid
);
957 static inline void init_reserved_page(unsigned long pfn
)
960 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
963 * Initialised pages do not have PageReserved set. This function is
964 * called for each range allocated by the bootmem allocator and
965 * marks the pages PageReserved. The remaining valid pages are later
966 * sent to the buddy page allocator.
968 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
970 unsigned long start_pfn
= PFN_DOWN(start
);
971 unsigned long end_pfn
= PFN_UP(end
);
973 for (; start_pfn
< end_pfn
; start_pfn
++) {
974 if (pfn_valid(start_pfn
)) {
975 struct page
*page
= pfn_to_page(start_pfn
);
977 init_reserved_page(start_pfn
);
979 /* Avoid false-positive PageTail() */
980 INIT_LIST_HEAD(&page
->lru
);
982 SetPageReserved(page
);
987 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
989 bool compound
= PageCompound(page
);
992 VM_BUG_ON_PAGE(PageTail(page
), page
);
993 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
995 trace_mm_page_free(page
, order
);
996 kmemcheck_free_shadow(page
, order
);
997 kasan_free_pages(page
, order
);
1000 page
->mapping
= NULL
;
1001 bad
+= free_pages_check(page
);
1002 for (i
= 1; i
< (1 << order
); i
++) {
1004 bad
+= free_tail_pages_check(page
, page
+ i
);
1005 bad
+= free_pages_check(page
+ i
);
1010 reset_page_owner(page
, order
);
1012 if (!PageHighMem(page
)) {
1013 debug_check_no_locks_freed(page_address(page
),
1014 PAGE_SIZE
<< order
);
1015 debug_check_no_obj_freed(page_address(page
),
1016 PAGE_SIZE
<< order
);
1018 arch_free_page(page
, order
);
1019 kernel_map_pages(page
, 1 << order
, 0);
1024 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1026 unsigned long flags
;
1028 unsigned long pfn
= page_to_pfn(page
);
1030 if (!free_pages_prepare(page
, order
))
1033 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1034 local_irq_save(flags
);
1035 __count_vm_events(PGFREE
, 1 << order
);
1036 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1037 local_irq_restore(flags
);
1040 static void __init
__free_pages_boot_core(struct page
*page
,
1041 unsigned long pfn
, unsigned int order
)
1043 unsigned int nr_pages
= 1 << order
;
1044 struct page
*p
= page
;
1048 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1050 __ClearPageReserved(p
);
1051 set_page_count(p
, 0);
1053 __ClearPageReserved(p
);
1054 set_page_count(p
, 0);
1056 page_zone(page
)->managed_pages
+= nr_pages
;
1057 set_page_refcounted(page
);
1058 __free_pages(page
, order
);
1061 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1062 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1064 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1066 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1068 static DEFINE_SPINLOCK(early_pfn_lock
);
1071 spin_lock(&early_pfn_lock
);
1072 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1074 nid
= first_online_node
;
1075 spin_unlock(&early_pfn_lock
);
1081 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1082 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1083 struct mminit_pfnnid_cache
*state
)
1087 nid
= __early_pfn_to_nid(pfn
, state
);
1088 if (nid
>= 0 && nid
!= node
)
1093 /* Only safe to use early in boot when initialisation is single-threaded */
1094 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1096 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1101 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1105 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1106 struct mminit_pfnnid_cache
*state
)
1113 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1116 if (early_page_uninitialised(pfn
))
1118 return __free_pages_boot_core(page
, pfn
, order
);
1121 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1122 static void __init
deferred_free_range(struct page
*page
,
1123 unsigned long pfn
, int nr_pages
)
1130 /* Free a large naturally-aligned chunk if possible */
1131 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1132 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1133 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1134 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1138 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1139 __free_pages_boot_core(page
, pfn
, 0);
1142 /* Completion tracking for deferred_init_memmap() threads */
1143 static atomic_t pgdat_init_n_undone __initdata
;
1144 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1146 static inline void __init
pgdat_init_report_one_done(void)
1148 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1149 complete(&pgdat_init_all_done_comp
);
1152 /* Initialise remaining memory on a node */
1153 static int __init
deferred_init_memmap(void *data
)
1155 pg_data_t
*pgdat
= data
;
1156 int nid
= pgdat
->node_id
;
1157 struct mminit_pfnnid_cache nid_init_state
= { };
1158 unsigned long start
= jiffies
;
1159 unsigned long nr_pages
= 0;
1160 unsigned long walk_start
, walk_end
;
1163 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1164 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1166 if (first_init_pfn
== ULONG_MAX
) {
1167 pgdat_init_report_one_done();
1171 /* Bind memory initialisation thread to a local node if possible */
1172 if (!cpumask_empty(cpumask
))
1173 set_cpus_allowed_ptr(current
, cpumask
);
1175 /* Sanity check boundaries */
1176 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1177 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1178 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1180 /* Only the highest zone is deferred so find it */
1181 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1182 zone
= pgdat
->node_zones
+ zid
;
1183 if (first_init_pfn
< zone_end_pfn(zone
))
1187 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1188 unsigned long pfn
, end_pfn
;
1189 struct page
*page
= NULL
;
1190 struct page
*free_base_page
= NULL
;
1191 unsigned long free_base_pfn
= 0;
1194 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1195 pfn
= first_init_pfn
;
1196 if (pfn
< walk_start
)
1198 if (pfn
< zone
->zone_start_pfn
)
1199 pfn
= zone
->zone_start_pfn
;
1201 for (; pfn
< end_pfn
; pfn
++) {
1202 if (!pfn_valid_within(pfn
))
1206 * Ensure pfn_valid is checked every
1207 * MAX_ORDER_NR_PAGES for memory holes
1209 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1210 if (!pfn_valid(pfn
)) {
1216 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1221 /* Minimise pfn page lookups and scheduler checks */
1222 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1225 nr_pages
+= nr_to_free
;
1226 deferred_free_range(free_base_page
,
1227 free_base_pfn
, nr_to_free
);
1228 free_base_page
= NULL
;
1229 free_base_pfn
= nr_to_free
= 0;
1231 page
= pfn_to_page(pfn
);
1236 VM_BUG_ON(page_zone(page
) != zone
);
1240 __init_single_page(page
, pfn
, zid
, nid
);
1241 if (!free_base_page
) {
1242 free_base_page
= page
;
1243 free_base_pfn
= pfn
;
1248 /* Where possible, batch up pages for a single free */
1251 /* Free the current block of pages to allocator */
1252 nr_pages
+= nr_to_free
;
1253 deferred_free_range(free_base_page
, free_base_pfn
,
1255 free_base_page
= NULL
;
1256 free_base_pfn
= nr_to_free
= 0;
1259 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1262 /* Sanity check that the next zone really is unpopulated */
1263 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1265 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1266 jiffies_to_msecs(jiffies
- start
));
1268 pgdat_init_report_one_done();
1272 void __init
page_alloc_init_late(void)
1276 /* There will be num_node_state(N_MEMORY) threads */
1277 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1278 for_each_node_state(nid
, N_MEMORY
) {
1279 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1282 /* Block until all are initialised */
1283 wait_for_completion(&pgdat_init_all_done_comp
);
1285 /* Reinit limits that are based on free pages after the kernel is up */
1286 files_maxfiles_init();
1288 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1291 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1292 void __init
init_cma_reserved_pageblock(struct page
*page
)
1294 unsigned i
= pageblock_nr_pages
;
1295 struct page
*p
= page
;
1298 __ClearPageReserved(p
);
1299 set_page_count(p
, 0);
1302 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1304 if (pageblock_order
>= MAX_ORDER
) {
1305 i
= pageblock_nr_pages
;
1308 set_page_refcounted(p
);
1309 __free_pages(p
, MAX_ORDER
- 1);
1310 p
+= MAX_ORDER_NR_PAGES
;
1311 } while (i
-= MAX_ORDER_NR_PAGES
);
1313 set_page_refcounted(page
);
1314 __free_pages(page
, pageblock_order
);
1317 adjust_managed_page_count(page
, pageblock_nr_pages
);
1322 * The order of subdivision here is critical for the IO subsystem.
1323 * Please do not alter this order without good reasons and regression
1324 * testing. Specifically, as large blocks of memory are subdivided,
1325 * the order in which smaller blocks are delivered depends on the order
1326 * they're subdivided in this function. This is the primary factor
1327 * influencing the order in which pages are delivered to the IO
1328 * subsystem according to empirical testing, and this is also justified
1329 * by considering the behavior of a buddy system containing a single
1330 * large block of memory acted on by a series of small allocations.
1331 * This behavior is a critical factor in sglist merging's success.
1335 static inline void expand(struct zone
*zone
, struct page
*page
,
1336 int low
, int high
, struct free_area
*area
,
1339 unsigned long size
= 1 << high
;
1341 while (high
> low
) {
1345 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1347 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1348 debug_guardpage_enabled() &&
1349 high
< debug_guardpage_minorder()) {
1351 * Mark as guard pages (or page), that will allow to
1352 * merge back to allocator when buddy will be freed.
1353 * Corresponding page table entries will not be touched,
1354 * pages will stay not present in virtual address space
1356 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1359 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1361 set_page_order(&page
[size
], high
);
1366 * This page is about to be returned from the page allocator
1368 static inline int check_new_page(struct page
*page
)
1370 const char *bad_reason
= NULL
;
1371 unsigned long bad_flags
= 0;
1373 if (unlikely(page_mapcount(page
)))
1374 bad_reason
= "nonzero mapcount";
1375 if (unlikely(page
->mapping
!= NULL
))
1376 bad_reason
= "non-NULL mapping";
1377 if (unlikely(atomic_read(&page
->_count
) != 0))
1378 bad_reason
= "nonzero _count";
1379 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1380 bad_reason
= "HWPoisoned (hardware-corrupted)";
1381 bad_flags
= __PG_HWPOISON
;
1383 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1384 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1385 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1388 if (unlikely(page
->mem_cgroup
))
1389 bad_reason
= "page still charged to cgroup";
1391 if (unlikely(bad_reason
)) {
1392 bad_page(page
, bad_reason
, bad_flags
);
1398 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1403 for (i
= 0; i
< (1 << order
); i
++) {
1404 struct page
*p
= page
+ i
;
1405 if (unlikely(check_new_page(p
)))
1409 set_page_private(page
, 0);
1410 set_page_refcounted(page
);
1412 arch_alloc_page(page
, order
);
1413 kernel_map_pages(page
, 1 << order
, 1);
1414 kasan_alloc_pages(page
, order
);
1416 if (gfp_flags
& __GFP_ZERO
)
1417 for (i
= 0; i
< (1 << order
); i
++)
1418 clear_highpage(page
+ i
);
1420 if (order
&& (gfp_flags
& __GFP_COMP
))
1421 prep_compound_page(page
, order
);
1423 set_page_owner(page
, order
, gfp_flags
);
1426 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1427 * allocate the page. The expectation is that the caller is taking
1428 * steps that will free more memory. The caller should avoid the page
1429 * being used for !PFMEMALLOC purposes.
1431 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1432 set_page_pfmemalloc(page
);
1434 clear_page_pfmemalloc(page
);
1440 * Go through the free lists for the given migratetype and remove
1441 * the smallest available page from the freelists
1444 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1447 unsigned int current_order
;
1448 struct free_area
*area
;
1451 /* Find a page of the appropriate size in the preferred list */
1452 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1453 area
= &(zone
->free_area
[current_order
]);
1454 if (list_empty(&area
->free_list
[migratetype
]))
1457 page
= list_entry(area
->free_list
[migratetype
].next
,
1459 list_del(&page
->lru
);
1460 rmv_page_order(page
);
1462 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1463 set_pcppage_migratetype(page
, migratetype
);
1472 * This array describes the order lists are fallen back to when
1473 * the free lists for the desirable migrate type are depleted
1475 static int fallbacks
[MIGRATE_TYPES
][4] = {
1476 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1477 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1478 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1480 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1482 #ifdef CONFIG_MEMORY_ISOLATION
1483 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1488 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1491 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1494 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1495 unsigned int order
) { return NULL
; }
1499 * Move the free pages in a range to the free lists of the requested type.
1500 * Note that start_page and end_pages are not aligned on a pageblock
1501 * boundary. If alignment is required, use move_freepages_block()
1503 int move_freepages(struct zone
*zone
,
1504 struct page
*start_page
, struct page
*end_page
,
1509 int pages_moved
= 0;
1511 #ifndef CONFIG_HOLES_IN_ZONE
1513 * page_zone is not safe to call in this context when
1514 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1515 * anyway as we check zone boundaries in move_freepages_block().
1516 * Remove at a later date when no bug reports exist related to
1517 * grouping pages by mobility
1519 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1522 for (page
= start_page
; page
<= end_page
;) {
1523 /* Make sure we are not inadvertently changing nodes */
1524 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1526 if (!pfn_valid_within(page_to_pfn(page
))) {
1531 if (!PageBuddy(page
)) {
1536 order
= page_order(page
);
1537 list_move(&page
->lru
,
1538 &zone
->free_area
[order
].free_list
[migratetype
]);
1540 pages_moved
+= 1 << order
;
1546 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1549 unsigned long start_pfn
, end_pfn
;
1550 struct page
*start_page
, *end_page
;
1552 start_pfn
= page_to_pfn(page
);
1553 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1554 start_page
= pfn_to_page(start_pfn
);
1555 end_page
= start_page
+ pageblock_nr_pages
- 1;
1556 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1558 /* Do not cross zone boundaries */
1559 if (!zone_spans_pfn(zone
, start_pfn
))
1561 if (!zone_spans_pfn(zone
, end_pfn
))
1564 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1567 static void change_pageblock_range(struct page
*pageblock_page
,
1568 int start_order
, int migratetype
)
1570 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1572 while (nr_pageblocks
--) {
1573 set_pageblock_migratetype(pageblock_page
, migratetype
);
1574 pageblock_page
+= pageblock_nr_pages
;
1579 * When we are falling back to another migratetype during allocation, try to
1580 * steal extra free pages from the same pageblocks to satisfy further
1581 * allocations, instead of polluting multiple pageblocks.
1583 * If we are stealing a relatively large buddy page, it is likely there will
1584 * be more free pages in the pageblock, so try to steal them all. For
1585 * reclaimable and unmovable allocations, we steal regardless of page size,
1586 * as fragmentation caused by those allocations polluting movable pageblocks
1587 * is worse than movable allocations stealing from unmovable and reclaimable
1590 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1593 * Leaving this order check is intended, although there is
1594 * relaxed order check in next check. The reason is that
1595 * we can actually steal whole pageblock if this condition met,
1596 * but, below check doesn't guarantee it and that is just heuristic
1597 * so could be changed anytime.
1599 if (order
>= pageblock_order
)
1602 if (order
>= pageblock_order
/ 2 ||
1603 start_mt
== MIGRATE_RECLAIMABLE
||
1604 start_mt
== MIGRATE_UNMOVABLE
||
1605 page_group_by_mobility_disabled
)
1612 * This function implements actual steal behaviour. If order is large enough,
1613 * we can steal whole pageblock. If not, we first move freepages in this
1614 * pageblock and check whether half of pages are moved or not. If half of
1615 * pages are moved, we can change migratetype of pageblock and permanently
1616 * use it's pages as requested migratetype in the future.
1618 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1621 unsigned int current_order
= page_order(page
);
1624 /* Take ownership for orders >= pageblock_order */
1625 if (current_order
>= pageblock_order
) {
1626 change_pageblock_range(page
, current_order
, start_type
);
1630 pages
= move_freepages_block(zone
, page
, start_type
);
1632 /* Claim the whole block if over half of it is free */
1633 if (pages
>= (1 << (pageblock_order
-1)) ||
1634 page_group_by_mobility_disabled
)
1635 set_pageblock_migratetype(page
, start_type
);
1639 * Check whether there is a suitable fallback freepage with requested order.
1640 * If only_stealable is true, this function returns fallback_mt only if
1641 * we can steal other freepages all together. This would help to reduce
1642 * fragmentation due to mixed migratetype pages in one pageblock.
1644 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1645 int migratetype
, bool only_stealable
, bool *can_steal
)
1650 if (area
->nr_free
== 0)
1655 fallback_mt
= fallbacks
[migratetype
][i
];
1656 if (fallback_mt
== MIGRATE_TYPES
)
1659 if (list_empty(&area
->free_list
[fallback_mt
]))
1662 if (can_steal_fallback(order
, migratetype
))
1665 if (!only_stealable
)
1676 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1677 * there are no empty page blocks that contain a page with a suitable order
1679 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
1680 unsigned int alloc_order
)
1683 unsigned long max_managed
, flags
;
1686 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1687 * Check is race-prone but harmless.
1689 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
1690 if (zone
->nr_reserved_highatomic
>= max_managed
)
1693 spin_lock_irqsave(&zone
->lock
, flags
);
1695 /* Recheck the nr_reserved_highatomic limit under the lock */
1696 if (zone
->nr_reserved_highatomic
>= max_managed
)
1700 mt
= get_pageblock_migratetype(page
);
1701 if (mt
!= MIGRATE_HIGHATOMIC
&&
1702 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
1703 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
1704 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
1705 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
1709 spin_unlock_irqrestore(&zone
->lock
, flags
);
1713 * Used when an allocation is about to fail under memory pressure. This
1714 * potentially hurts the reliability of high-order allocations when under
1715 * intense memory pressure but failed atomic allocations should be easier
1716 * to recover from than an OOM.
1718 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
1720 struct zonelist
*zonelist
= ac
->zonelist
;
1721 unsigned long flags
;
1727 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
1729 /* Preserve at least one pageblock */
1730 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
1733 spin_lock_irqsave(&zone
->lock
, flags
);
1734 for (order
= 0; order
< MAX_ORDER
; order
++) {
1735 struct free_area
*area
= &(zone
->free_area
[order
]);
1737 if (list_empty(&area
->free_list
[MIGRATE_HIGHATOMIC
]))
1740 page
= list_entry(area
->free_list
[MIGRATE_HIGHATOMIC
].next
,
1744 * It should never happen but changes to locking could
1745 * inadvertently allow a per-cpu drain to add pages
1746 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1747 * and watch for underflows.
1749 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
1750 zone
->nr_reserved_highatomic
);
1753 * Convert to ac->migratetype and avoid the normal
1754 * pageblock stealing heuristics. Minimally, the caller
1755 * is doing the work and needs the pages. More
1756 * importantly, if the block was always converted to
1757 * MIGRATE_UNMOVABLE or another type then the number
1758 * of pageblocks that cannot be completely freed
1761 set_pageblock_migratetype(page
, ac
->migratetype
);
1762 move_freepages_block(zone
, page
, ac
->migratetype
);
1763 spin_unlock_irqrestore(&zone
->lock
, flags
);
1766 spin_unlock_irqrestore(&zone
->lock
, flags
);
1770 /* Remove an element from the buddy allocator from the fallback list */
1771 static inline struct page
*
1772 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1774 struct free_area
*area
;
1775 unsigned int current_order
;
1780 /* Find the largest possible block of pages in the other list */
1781 for (current_order
= MAX_ORDER
-1;
1782 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1784 area
= &(zone
->free_area
[current_order
]);
1785 fallback_mt
= find_suitable_fallback(area
, current_order
,
1786 start_migratetype
, false, &can_steal
);
1787 if (fallback_mt
== -1)
1790 page
= list_entry(area
->free_list
[fallback_mt
].next
,
1793 steal_suitable_fallback(zone
, page
, start_migratetype
);
1795 /* Remove the page from the freelists */
1797 list_del(&page
->lru
);
1798 rmv_page_order(page
);
1800 expand(zone
, page
, order
, current_order
, area
,
1803 * The pcppage_migratetype may differ from pageblock's
1804 * migratetype depending on the decisions in
1805 * find_suitable_fallback(). This is OK as long as it does not
1806 * differ for MIGRATE_CMA pageblocks. Those can be used as
1807 * fallback only via special __rmqueue_cma_fallback() function
1809 set_pcppage_migratetype(page
, start_migratetype
);
1811 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1812 start_migratetype
, fallback_mt
);
1821 * Do the hard work of removing an element from the buddy allocator.
1822 * Call me with the zone->lock already held.
1824 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1825 int migratetype
, gfp_t gfp_flags
)
1829 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1830 if (unlikely(!page
)) {
1831 if (migratetype
== MIGRATE_MOVABLE
)
1832 page
= __rmqueue_cma_fallback(zone
, order
);
1835 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1838 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1843 * Obtain a specified number of elements from the buddy allocator, all under
1844 * a single hold of the lock, for efficiency. Add them to the supplied list.
1845 * Returns the number of new pages which were placed at *list.
1847 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1848 unsigned long count
, struct list_head
*list
,
1849 int migratetype
, bool cold
)
1853 spin_lock(&zone
->lock
);
1854 for (i
= 0; i
< count
; ++i
) {
1855 struct page
*page
= __rmqueue(zone
, order
, migratetype
, 0);
1856 if (unlikely(page
== NULL
))
1860 * Split buddy pages returned by expand() are received here
1861 * in physical page order. The page is added to the callers and
1862 * list and the list head then moves forward. From the callers
1863 * perspective, the linked list is ordered by page number in
1864 * some conditions. This is useful for IO devices that can
1865 * merge IO requests if the physical pages are ordered
1869 list_add(&page
->lru
, list
);
1871 list_add_tail(&page
->lru
, list
);
1873 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1874 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1877 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1878 spin_unlock(&zone
->lock
);
1884 * Called from the vmstat counter updater to drain pagesets of this
1885 * currently executing processor on remote nodes after they have
1888 * Note that this function must be called with the thread pinned to
1889 * a single processor.
1891 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1893 unsigned long flags
;
1894 int to_drain
, batch
;
1896 local_irq_save(flags
);
1897 batch
= READ_ONCE(pcp
->batch
);
1898 to_drain
= min(pcp
->count
, batch
);
1900 free_pcppages_bulk(zone
, to_drain
, pcp
);
1901 pcp
->count
-= to_drain
;
1903 local_irq_restore(flags
);
1908 * Drain pcplists of the indicated processor and zone.
1910 * The processor must either be the current processor and the
1911 * thread pinned to the current processor or a processor that
1914 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1916 unsigned long flags
;
1917 struct per_cpu_pageset
*pset
;
1918 struct per_cpu_pages
*pcp
;
1920 local_irq_save(flags
);
1921 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1925 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1928 local_irq_restore(flags
);
1932 * Drain pcplists of all zones on the indicated processor.
1934 * The processor must either be the current processor and the
1935 * thread pinned to the current processor or a processor that
1938 static void drain_pages(unsigned int cpu
)
1942 for_each_populated_zone(zone
) {
1943 drain_pages_zone(cpu
, zone
);
1948 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1950 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1951 * the single zone's pages.
1953 void drain_local_pages(struct zone
*zone
)
1955 int cpu
= smp_processor_id();
1958 drain_pages_zone(cpu
, zone
);
1964 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1966 * When zone parameter is non-NULL, spill just the single zone's pages.
1968 * Note that this code is protected against sending an IPI to an offline
1969 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1970 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1971 * nothing keeps CPUs from showing up after we populated the cpumask and
1972 * before the call to on_each_cpu_mask().
1974 void drain_all_pages(struct zone
*zone
)
1979 * Allocate in the BSS so we wont require allocation in
1980 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1982 static cpumask_t cpus_with_pcps
;
1985 * We don't care about racing with CPU hotplug event
1986 * as offline notification will cause the notified
1987 * cpu to drain that CPU pcps and on_each_cpu_mask
1988 * disables preemption as part of its processing
1990 for_each_online_cpu(cpu
) {
1991 struct per_cpu_pageset
*pcp
;
1993 bool has_pcps
= false;
1996 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2000 for_each_populated_zone(z
) {
2001 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2002 if (pcp
->pcp
.count
) {
2010 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2012 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2014 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2018 #ifdef CONFIG_HIBERNATION
2020 void mark_free_pages(struct zone
*zone
)
2022 unsigned long pfn
, max_zone_pfn
;
2023 unsigned long flags
;
2024 unsigned int order
, t
;
2025 struct list_head
*curr
;
2027 if (zone_is_empty(zone
))
2030 spin_lock_irqsave(&zone
->lock
, flags
);
2032 max_zone_pfn
= zone_end_pfn(zone
);
2033 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2034 if (pfn_valid(pfn
)) {
2035 struct page
*page
= pfn_to_page(pfn
);
2037 if (!swsusp_page_is_forbidden(page
))
2038 swsusp_unset_page_free(page
);
2041 for_each_migratetype_order(order
, t
) {
2042 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
2045 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
2046 for (i
= 0; i
< (1UL << order
); i
++)
2047 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2050 spin_unlock_irqrestore(&zone
->lock
, flags
);
2052 #endif /* CONFIG_PM */
2055 * Free a 0-order page
2056 * cold == true ? free a cold page : free a hot page
2058 void free_hot_cold_page(struct page
*page
, bool cold
)
2060 struct zone
*zone
= page_zone(page
);
2061 struct per_cpu_pages
*pcp
;
2062 unsigned long flags
;
2063 unsigned long pfn
= page_to_pfn(page
);
2066 if (!free_pages_prepare(page
, 0))
2069 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2070 set_pcppage_migratetype(page
, migratetype
);
2071 local_irq_save(flags
);
2072 __count_vm_event(PGFREE
);
2075 * We only track unmovable, reclaimable and movable on pcp lists.
2076 * Free ISOLATE pages back to the allocator because they are being
2077 * offlined but treat RESERVE as movable pages so we can get those
2078 * areas back if necessary. Otherwise, we may have to free
2079 * excessively into the page allocator
2081 if (migratetype
>= MIGRATE_PCPTYPES
) {
2082 if (unlikely(is_migrate_isolate(migratetype
))) {
2083 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2086 migratetype
= MIGRATE_MOVABLE
;
2089 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2091 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2093 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2095 if (pcp
->count
>= pcp
->high
) {
2096 unsigned long batch
= READ_ONCE(pcp
->batch
);
2097 free_pcppages_bulk(zone
, batch
, pcp
);
2098 pcp
->count
-= batch
;
2102 local_irq_restore(flags
);
2106 * Free a list of 0-order pages
2108 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2110 struct page
*page
, *next
;
2112 list_for_each_entry_safe(page
, next
, list
, lru
) {
2113 trace_mm_page_free_batched(page
, cold
);
2114 free_hot_cold_page(page
, cold
);
2119 * split_page takes a non-compound higher-order page, and splits it into
2120 * n (1<<order) sub-pages: page[0..n]
2121 * Each sub-page must be freed individually.
2123 * Note: this is probably too low level an operation for use in drivers.
2124 * Please consult with lkml before using this in your driver.
2126 void split_page(struct page
*page
, unsigned int order
)
2131 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2132 VM_BUG_ON_PAGE(!page_count(page
), page
);
2134 #ifdef CONFIG_KMEMCHECK
2136 * Split shadow pages too, because free(page[0]) would
2137 * otherwise free the whole shadow.
2139 if (kmemcheck_page_is_tracked(page
))
2140 split_page(virt_to_page(page
[0].shadow
), order
);
2143 gfp_mask
= get_page_owner_gfp(page
);
2144 set_page_owner(page
, 0, gfp_mask
);
2145 for (i
= 1; i
< (1 << order
); i
++) {
2146 set_page_refcounted(page
+ i
);
2147 set_page_owner(page
+ i
, 0, gfp_mask
);
2150 EXPORT_SYMBOL_GPL(split_page
);
2152 int __isolate_free_page(struct page
*page
, unsigned int order
)
2154 unsigned long watermark
;
2158 BUG_ON(!PageBuddy(page
));
2160 zone
= page_zone(page
);
2161 mt
= get_pageblock_migratetype(page
);
2163 if (!is_migrate_isolate(mt
)) {
2164 /* Obey watermarks as if the page was being allocated */
2165 watermark
= low_wmark_pages(zone
) + (1 << order
);
2166 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2169 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2172 /* Remove page from free list */
2173 list_del(&page
->lru
);
2174 zone
->free_area
[order
].nr_free
--;
2175 rmv_page_order(page
);
2177 set_page_owner(page
, order
, __GFP_MOVABLE
);
2179 /* Set the pageblock if the isolated page is at least a pageblock */
2180 if (order
>= pageblock_order
- 1) {
2181 struct page
*endpage
= page
+ (1 << order
) - 1;
2182 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2183 int mt
= get_pageblock_migratetype(page
);
2184 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2185 set_pageblock_migratetype(page
,
2191 return 1UL << order
;
2195 * Similar to split_page except the page is already free. As this is only
2196 * being used for migration, the migratetype of the block also changes.
2197 * As this is called with interrupts disabled, the caller is responsible
2198 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2201 * Note: this is probably too low level an operation for use in drivers.
2202 * Please consult with lkml before using this in your driver.
2204 int split_free_page(struct page
*page
)
2209 order
= page_order(page
);
2211 nr_pages
= __isolate_free_page(page
, order
);
2215 /* Split into individual pages */
2216 set_page_refcounted(page
);
2217 split_page(page
, order
);
2222 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2225 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2226 struct zone
*zone
, unsigned int order
,
2227 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2229 unsigned long flags
;
2231 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2233 if (likely(order
== 0)) {
2234 struct per_cpu_pages
*pcp
;
2235 struct list_head
*list
;
2237 local_irq_save(flags
);
2238 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2239 list
= &pcp
->lists
[migratetype
];
2240 if (list_empty(list
)) {
2241 pcp
->count
+= rmqueue_bulk(zone
, 0,
2244 if (unlikely(list_empty(list
)))
2249 page
= list_entry(list
->prev
, struct page
, lru
);
2251 page
= list_entry(list
->next
, struct page
, lru
);
2253 list_del(&page
->lru
);
2256 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
2258 * __GFP_NOFAIL is not to be used in new code.
2260 * All __GFP_NOFAIL callers should be fixed so that they
2261 * properly detect and handle allocation failures.
2263 * We most definitely don't want callers attempting to
2264 * allocate greater than order-1 page units with
2267 WARN_ON_ONCE(order
> 1);
2269 spin_lock_irqsave(&zone
->lock
, flags
);
2272 if (alloc_flags
& ALLOC_HARDER
) {
2273 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2275 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2278 page
= __rmqueue(zone
, order
, migratetype
, gfp_flags
);
2279 spin_unlock(&zone
->lock
);
2282 __mod_zone_freepage_state(zone
, -(1 << order
),
2283 get_pcppage_migratetype(page
));
2286 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2287 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2288 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2289 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2291 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2292 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2293 local_irq_restore(flags
);
2295 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2299 local_irq_restore(flags
);
2303 #ifdef CONFIG_FAIL_PAGE_ALLOC
2306 struct fault_attr attr
;
2308 bool ignore_gfp_highmem
;
2309 bool ignore_gfp_reclaim
;
2311 } fail_page_alloc
= {
2312 .attr
= FAULT_ATTR_INITIALIZER
,
2313 .ignore_gfp_reclaim
= true,
2314 .ignore_gfp_highmem
= true,
2318 static int __init
setup_fail_page_alloc(char *str
)
2320 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2322 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2324 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2326 if (order
< fail_page_alloc
.min_order
)
2328 if (gfp_mask
& __GFP_NOFAIL
)
2330 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2332 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2333 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2336 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2339 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2341 static int __init
fail_page_alloc_debugfs(void)
2343 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2346 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2347 &fail_page_alloc
.attr
);
2349 return PTR_ERR(dir
);
2351 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2352 &fail_page_alloc
.ignore_gfp_reclaim
))
2354 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2355 &fail_page_alloc
.ignore_gfp_highmem
))
2357 if (!debugfs_create_u32("min-order", mode
, dir
,
2358 &fail_page_alloc
.min_order
))
2363 debugfs_remove_recursive(dir
);
2368 late_initcall(fail_page_alloc_debugfs
);
2370 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2372 #else /* CONFIG_FAIL_PAGE_ALLOC */
2374 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2379 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2382 * Return true if free base pages are above 'mark'. For high-order checks it
2383 * will return true of the order-0 watermark is reached and there is at least
2384 * one free page of a suitable size. Checking now avoids taking the zone lock
2385 * to check in the allocation paths if no pages are free.
2387 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2388 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2393 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2395 /* free_pages may go negative - that's OK */
2396 free_pages
-= (1 << order
) - 1;
2398 if (alloc_flags
& ALLOC_HIGH
)
2402 * If the caller does not have rights to ALLOC_HARDER then subtract
2403 * the high-atomic reserves. This will over-estimate the size of the
2404 * atomic reserve but it avoids a search.
2406 if (likely(!alloc_harder
))
2407 free_pages
-= z
->nr_reserved_highatomic
;
2412 /* If allocation can't use CMA areas don't use free CMA pages */
2413 if (!(alloc_flags
& ALLOC_CMA
))
2414 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2418 * Check watermarks for an order-0 allocation request. If these
2419 * are not met, then a high-order request also cannot go ahead
2420 * even if a suitable page happened to be free.
2422 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2425 /* If this is an order-0 request then the watermark is fine */
2429 /* For a high-order request, check at least one suitable page is free */
2430 for (o
= order
; o
< MAX_ORDER
; o
++) {
2431 struct free_area
*area
= &z
->free_area
[o
];
2440 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2441 if (!list_empty(&area
->free_list
[mt
]))
2446 if ((alloc_flags
& ALLOC_CMA
) &&
2447 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2455 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2456 int classzone_idx
, int alloc_flags
)
2458 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2459 zone_page_state(z
, NR_FREE_PAGES
));
2462 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2463 unsigned long mark
, int classzone_idx
)
2465 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2467 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2468 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2470 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2475 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2477 return local_zone
->node
== zone
->node
;
2480 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2482 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
2485 #else /* CONFIG_NUMA */
2486 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2491 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2495 #endif /* CONFIG_NUMA */
2497 static void reset_alloc_batches(struct zone
*preferred_zone
)
2499 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2502 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2503 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2504 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2505 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2506 } while (zone
++ != preferred_zone
);
2510 * get_page_from_freelist goes through the zonelist trying to allocate
2513 static struct page
*
2514 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2515 const struct alloc_context
*ac
)
2517 struct zonelist
*zonelist
= ac
->zonelist
;
2519 struct page
*page
= NULL
;
2521 int nr_fair_skipped
= 0;
2522 bool zonelist_rescan
;
2525 zonelist_rescan
= false;
2528 * Scan zonelist, looking for a zone with enough free.
2529 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2531 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2535 if (cpusets_enabled() &&
2536 (alloc_flags
& ALLOC_CPUSET
) &&
2537 !cpuset_zone_allowed(zone
, gfp_mask
))
2540 * Distribute pages in proportion to the individual
2541 * zone size to ensure fair page aging. The zone a
2542 * page was allocated in should have no effect on the
2543 * time the page has in memory before being reclaimed.
2545 if (alloc_flags
& ALLOC_FAIR
) {
2546 if (!zone_local(ac
->preferred_zone
, zone
))
2548 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2554 * When allocating a page cache page for writing, we
2555 * want to get it from a zone that is within its dirty
2556 * limit, such that no single zone holds more than its
2557 * proportional share of globally allowed dirty pages.
2558 * The dirty limits take into account the zone's
2559 * lowmem reserves and high watermark so that kswapd
2560 * should be able to balance it without having to
2561 * write pages from its LRU list.
2563 * This may look like it could increase pressure on
2564 * lower zones by failing allocations in higher zones
2565 * before they are full. But the pages that do spill
2566 * over are limited as the lower zones are protected
2567 * by this very same mechanism. It should not become
2568 * a practical burden to them.
2570 * XXX: For now, allow allocations to potentially
2571 * exceed the per-zone dirty limit in the slowpath
2572 * (spread_dirty_pages unset) before going into reclaim,
2573 * which is important when on a NUMA setup the allowed
2574 * zones are together not big enough to reach the
2575 * global limit. The proper fix for these situations
2576 * will require awareness of zones in the
2577 * dirty-throttling and the flusher threads.
2579 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2582 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2583 if (!zone_watermark_ok(zone
, order
, mark
,
2584 ac
->classzone_idx
, alloc_flags
)) {
2587 /* Checked here to keep the fast path fast */
2588 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2589 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2592 if (zone_reclaim_mode
== 0 ||
2593 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2596 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2598 case ZONE_RECLAIM_NOSCAN
:
2601 case ZONE_RECLAIM_FULL
:
2602 /* scanned but unreclaimable */
2605 /* did we reclaim enough */
2606 if (zone_watermark_ok(zone
, order
, mark
,
2607 ac
->classzone_idx
, alloc_flags
))
2615 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2616 gfp_mask
, alloc_flags
, ac
->migratetype
);
2618 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2622 * If this is a high-order atomic allocation then check
2623 * if the pageblock should be reserved for the future
2625 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2626 reserve_highatomic_pageblock(page
, zone
, order
);
2633 * The first pass makes sure allocations are spread fairly within the
2634 * local node. However, the local node might have free pages left
2635 * after the fairness batches are exhausted, and remote zones haven't
2636 * even been considered yet. Try once more without fairness, and
2637 * include remote zones now, before entering the slowpath and waking
2638 * kswapd: prefer spilling to a remote zone over swapping locally.
2640 if (alloc_flags
& ALLOC_FAIR
) {
2641 alloc_flags
&= ~ALLOC_FAIR
;
2642 if (nr_fair_skipped
) {
2643 zonelist_rescan
= true;
2644 reset_alloc_batches(ac
->preferred_zone
);
2646 if (nr_online_nodes
> 1)
2647 zonelist_rescan
= true;
2650 if (zonelist_rescan
)
2657 * Large machines with many possible nodes should not always dump per-node
2658 * meminfo in irq context.
2660 static inline bool should_suppress_show_mem(void)
2665 ret
= in_interrupt();
2670 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2671 DEFAULT_RATELIMIT_INTERVAL
,
2672 DEFAULT_RATELIMIT_BURST
);
2674 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2676 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2678 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2679 debug_guardpage_minorder() > 0)
2683 * This documents exceptions given to allocations in certain
2684 * contexts that are allowed to allocate outside current's set
2687 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2688 if (test_thread_flag(TIF_MEMDIE
) ||
2689 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2690 filter
&= ~SHOW_MEM_FILTER_NODES
;
2691 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2692 filter
&= ~SHOW_MEM_FILTER_NODES
;
2695 struct va_format vaf
;
2698 va_start(args
, fmt
);
2703 pr_warn("%pV", &vaf
);
2708 pr_warn("%s: page allocation failure: order:%u, mode:0x%x\n",
2709 current
->comm
, order
, gfp_mask
);
2712 if (!should_suppress_show_mem())
2716 static inline struct page
*
2717 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2718 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2720 struct oom_control oc
= {
2721 .zonelist
= ac
->zonelist
,
2722 .nodemask
= ac
->nodemask
,
2723 .gfp_mask
= gfp_mask
,
2728 *did_some_progress
= 0;
2731 * Acquire the oom lock. If that fails, somebody else is
2732 * making progress for us.
2734 if (!mutex_trylock(&oom_lock
)) {
2735 *did_some_progress
= 1;
2736 schedule_timeout_uninterruptible(1);
2741 * Go through the zonelist yet one more time, keep very high watermark
2742 * here, this is only to catch a parallel oom killing, we must fail if
2743 * we're still under heavy pressure.
2745 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2746 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2750 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2751 /* Coredumps can quickly deplete all memory reserves */
2752 if (current
->flags
& PF_DUMPCORE
)
2754 /* The OOM killer will not help higher order allocs */
2755 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2757 /* The OOM killer does not needlessly kill tasks for lowmem */
2758 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2760 /* The OOM killer does not compensate for IO-less reclaim */
2761 if (!(gfp_mask
& __GFP_FS
)) {
2763 * XXX: Page reclaim didn't yield anything,
2764 * and the OOM killer can't be invoked, but
2765 * keep looping as per tradition.
2767 *did_some_progress
= 1;
2770 if (pm_suspended_storage())
2772 /* The OOM killer may not free memory on a specific node */
2773 if (gfp_mask
& __GFP_THISNODE
)
2776 /* Exhausted what can be done so it's blamo time */
2777 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
))
2778 *did_some_progress
= 1;
2780 mutex_unlock(&oom_lock
);
2784 #ifdef CONFIG_COMPACTION
2785 /* Try memory compaction for high-order allocations before reclaim */
2786 static struct page
*
2787 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2788 int alloc_flags
, const struct alloc_context
*ac
,
2789 enum migrate_mode mode
, int *contended_compaction
,
2790 bool *deferred_compaction
)
2792 unsigned long compact_result
;
2798 current
->flags
|= PF_MEMALLOC
;
2799 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2800 mode
, contended_compaction
);
2801 current
->flags
&= ~PF_MEMALLOC
;
2803 switch (compact_result
) {
2804 case COMPACT_DEFERRED
:
2805 *deferred_compaction
= true;
2807 case COMPACT_SKIPPED
:
2814 * At least in one zone compaction wasn't deferred or skipped, so let's
2815 * count a compaction stall
2817 count_vm_event(COMPACTSTALL
);
2819 page
= get_page_from_freelist(gfp_mask
, order
,
2820 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2823 struct zone
*zone
= page_zone(page
);
2825 zone
->compact_blockskip_flush
= false;
2826 compaction_defer_reset(zone
, order
, true);
2827 count_vm_event(COMPACTSUCCESS
);
2832 * It's bad if compaction run occurs and fails. The most likely reason
2833 * is that pages exist, but not enough to satisfy watermarks.
2835 count_vm_event(COMPACTFAIL
);
2842 static inline struct page
*
2843 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2844 int alloc_flags
, const struct alloc_context
*ac
,
2845 enum migrate_mode mode
, int *contended_compaction
,
2846 bool *deferred_compaction
)
2850 #endif /* CONFIG_COMPACTION */
2852 /* Perform direct synchronous page reclaim */
2854 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2855 const struct alloc_context
*ac
)
2857 struct reclaim_state reclaim_state
;
2862 /* We now go into synchronous reclaim */
2863 cpuset_memory_pressure_bump();
2864 current
->flags
|= PF_MEMALLOC
;
2865 lockdep_set_current_reclaim_state(gfp_mask
);
2866 reclaim_state
.reclaimed_slab
= 0;
2867 current
->reclaim_state
= &reclaim_state
;
2869 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2872 current
->reclaim_state
= NULL
;
2873 lockdep_clear_current_reclaim_state();
2874 current
->flags
&= ~PF_MEMALLOC
;
2881 /* The really slow allocator path where we enter direct reclaim */
2882 static inline struct page
*
2883 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2884 int alloc_flags
, const struct alloc_context
*ac
,
2885 unsigned long *did_some_progress
)
2887 struct page
*page
= NULL
;
2888 bool drained
= false;
2890 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2891 if (unlikely(!(*did_some_progress
)))
2895 page
= get_page_from_freelist(gfp_mask
, order
,
2896 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2899 * If an allocation failed after direct reclaim, it could be because
2900 * pages are pinned on the per-cpu lists or in high alloc reserves.
2901 * Shrink them them and try again
2903 if (!page
&& !drained
) {
2904 unreserve_highatomic_pageblock(ac
);
2905 drain_all_pages(NULL
);
2914 * This is called in the allocator slow-path if the allocation request is of
2915 * sufficient urgency to ignore watermarks and take other desperate measures
2917 static inline struct page
*
2918 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2919 const struct alloc_context
*ac
)
2924 page
= get_page_from_freelist(gfp_mask
, order
,
2925 ALLOC_NO_WATERMARKS
, ac
);
2927 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2928 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
,
2930 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2935 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2940 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2941 ac
->high_zoneidx
, ac
->nodemask
)
2942 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2946 gfp_to_alloc_flags(gfp_t gfp_mask
)
2948 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2950 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2951 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2954 * The caller may dip into page reserves a bit more if the caller
2955 * cannot run direct reclaim, or if the caller has realtime scheduling
2956 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2957 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
2959 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2961 if (gfp_mask
& __GFP_ATOMIC
) {
2963 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2964 * if it can't schedule.
2966 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2967 alloc_flags
|= ALLOC_HARDER
;
2969 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2970 * comment for __cpuset_node_allowed().
2972 alloc_flags
&= ~ALLOC_CPUSET
;
2973 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2974 alloc_flags
|= ALLOC_HARDER
;
2976 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2977 if (gfp_mask
& __GFP_MEMALLOC
)
2978 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2979 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2980 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2981 else if (!in_interrupt() &&
2982 ((current
->flags
& PF_MEMALLOC
) ||
2983 unlikely(test_thread_flag(TIF_MEMDIE
))))
2984 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2987 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2988 alloc_flags
|= ALLOC_CMA
;
2993 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2995 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2998 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3000 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3003 static inline struct page
*
3004 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3005 struct alloc_context
*ac
)
3007 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3008 struct page
*page
= NULL
;
3010 unsigned long pages_reclaimed
= 0;
3011 unsigned long did_some_progress
;
3012 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3013 bool deferred_compaction
= false;
3014 int contended_compaction
= COMPACT_CONTENDED_NONE
;
3017 * In the slowpath, we sanity check order to avoid ever trying to
3018 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3019 * be using allocators in order of preference for an area that is
3022 if (order
>= MAX_ORDER
) {
3023 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3028 * We also sanity check to catch abuse of atomic reserves being used by
3029 * callers that are not in atomic context.
3031 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3032 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3033 gfp_mask
&= ~__GFP_ATOMIC
;
3036 * If this allocation cannot block and it is for a specific node, then
3037 * fail early. There's no need to wakeup kswapd or retry for a
3038 * speculative node-specific allocation.
3040 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !can_direct_reclaim
)
3044 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3045 wake_all_kswapds(order
, ac
);
3048 * OK, we're below the kswapd watermark and have kicked background
3049 * reclaim. Now things get more complex, so set up alloc_flags according
3050 * to how we want to proceed.
3052 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3055 * Find the true preferred zone if the allocation is unconstrained by
3058 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3059 struct zoneref
*preferred_zoneref
;
3060 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3061 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3062 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3065 /* This is the last chance, in general, before the goto nopage. */
3066 page
= get_page_from_freelist(gfp_mask
, order
,
3067 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3071 /* Allocate without watermarks if the context allows */
3072 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3074 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3075 * the allocation is high priority and these type of
3076 * allocations are system rather than user orientated
3078 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3080 page
= __alloc_pages_high_priority(gfp_mask
, order
, ac
);
3087 /* Caller is not willing to reclaim, we can't balance anything */
3088 if (!can_direct_reclaim
) {
3090 * All existing users of the deprecated __GFP_NOFAIL are
3091 * blockable, so warn of any new users that actually allow this
3092 * type of allocation to fail.
3094 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3098 /* Avoid recursion of direct reclaim */
3099 if (current
->flags
& PF_MEMALLOC
)
3102 /* Avoid allocations with no watermarks from looping endlessly */
3103 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3107 * Try direct compaction. The first pass is asynchronous. Subsequent
3108 * attempts after direct reclaim are synchronous
3110 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3112 &contended_compaction
,
3113 &deferred_compaction
);
3117 /* Checks for THP-specific high-order allocations */
3118 if (is_thp_gfp_mask(gfp_mask
)) {
3120 * If compaction is deferred for high-order allocations, it is
3121 * because sync compaction recently failed. If this is the case
3122 * and the caller requested a THP allocation, we do not want
3123 * to heavily disrupt the system, so we fail the allocation
3124 * instead of entering direct reclaim.
3126 if (deferred_compaction
)
3130 * In all zones where compaction was attempted (and not
3131 * deferred or skipped), lock contention has been detected.
3132 * For THP allocation we do not want to disrupt the others
3133 * so we fallback to base pages instead.
3135 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3139 * If compaction was aborted due to need_resched(), we do not
3140 * want to further increase allocation latency, unless it is
3141 * khugepaged trying to collapse.
3143 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3144 && !(current
->flags
& PF_KTHREAD
))
3149 * It can become very expensive to allocate transparent hugepages at
3150 * fault, so use asynchronous memory compaction for THP unless it is
3151 * khugepaged trying to collapse.
3153 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3154 migration_mode
= MIGRATE_SYNC_LIGHT
;
3156 /* Try direct reclaim and then allocating */
3157 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3158 &did_some_progress
);
3162 /* Do not loop if specifically requested */
3163 if (gfp_mask
& __GFP_NORETRY
)
3166 /* Keep reclaiming pages as long as there is reasonable progress */
3167 pages_reclaimed
+= did_some_progress
;
3168 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3169 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3170 /* Wait for some write requests to complete then retry */
3171 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3175 /* Reclaim has failed us, start killing things */
3176 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3180 /* Retry as long as the OOM killer is making progress */
3181 if (did_some_progress
)
3186 * High-order allocations do not necessarily loop after
3187 * direct reclaim and reclaim/compaction depends on compaction
3188 * being called after reclaim so call directly if necessary
3190 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3192 &contended_compaction
,
3193 &deferred_compaction
);
3197 warn_alloc_failed(gfp_mask
, order
, NULL
);
3203 * This is the 'heart' of the zoned buddy allocator.
3206 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3207 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3209 struct zoneref
*preferred_zoneref
;
3210 struct page
*page
= NULL
;
3211 unsigned int cpuset_mems_cookie
;
3212 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3213 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3214 struct alloc_context ac
= {
3215 .high_zoneidx
= gfp_zone(gfp_mask
),
3216 .nodemask
= nodemask
,
3217 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3220 gfp_mask
&= gfp_allowed_mask
;
3222 lockdep_trace_alloc(gfp_mask
);
3224 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3226 if (should_fail_alloc_page(gfp_mask
, order
))
3230 * Check the zones suitable for the gfp_mask contain at least one
3231 * valid zone. It's possible to have an empty zonelist as a result
3232 * of __GFP_THISNODE and a memoryless node
3234 if (unlikely(!zonelist
->_zonerefs
->zone
))
3237 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3238 alloc_flags
|= ALLOC_CMA
;
3241 cpuset_mems_cookie
= read_mems_allowed_begin();
3243 /* We set it here, as __alloc_pages_slowpath might have changed it */
3244 ac
.zonelist
= zonelist
;
3246 /* Dirty zone balancing only done in the fast path */
3247 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3249 /* The preferred zone is used for statistics later */
3250 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3251 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3252 &ac
.preferred_zone
);
3253 if (!ac
.preferred_zone
)
3255 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3257 /* First allocation attempt */
3258 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3259 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3260 if (unlikely(!page
)) {
3262 * Runtime PM, block IO and its error handling path
3263 * can deadlock because I/O on the device might not
3266 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3267 ac
.spread_dirty_pages
= false;
3269 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3272 if (kmemcheck_enabled
&& page
)
3273 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3275 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3279 * When updating a task's mems_allowed, it is possible to race with
3280 * parallel threads in such a way that an allocation can fail while
3281 * the mask is being updated. If a page allocation is about to fail,
3282 * check if the cpuset changed during allocation and if so, retry.
3284 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3289 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3292 * Common helper functions.
3294 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3299 * __get_free_pages() returns a 32-bit address, which cannot represent
3302 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3304 page
= alloc_pages(gfp_mask
, order
);
3307 return (unsigned long) page_address(page
);
3309 EXPORT_SYMBOL(__get_free_pages
);
3311 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3313 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3315 EXPORT_SYMBOL(get_zeroed_page
);
3317 void __free_pages(struct page
*page
, unsigned int order
)
3319 if (put_page_testzero(page
)) {
3321 free_hot_cold_page(page
, false);
3323 __free_pages_ok(page
, order
);
3327 EXPORT_SYMBOL(__free_pages
);
3329 void free_pages(unsigned long addr
, unsigned int order
)
3332 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3333 __free_pages(virt_to_page((void *)addr
), order
);
3337 EXPORT_SYMBOL(free_pages
);
3341 * An arbitrary-length arbitrary-offset area of memory which resides
3342 * within a 0 or higher order page. Multiple fragments within that page
3343 * are individually refcounted, in the page's reference counter.
3345 * The page_frag functions below provide a simple allocation framework for
3346 * page fragments. This is used by the network stack and network device
3347 * drivers to provide a backing region of memory for use as either an
3348 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3350 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3353 struct page
*page
= NULL
;
3354 gfp_t gfp
= gfp_mask
;
3356 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3357 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3359 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3360 PAGE_FRAG_CACHE_MAX_ORDER
);
3361 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3363 if (unlikely(!page
))
3364 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3366 nc
->va
= page
? page_address(page
) : NULL
;
3371 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3372 unsigned int fragsz
, gfp_t gfp_mask
)
3374 unsigned int size
= PAGE_SIZE
;
3378 if (unlikely(!nc
->va
)) {
3380 page
= __page_frag_refill(nc
, gfp_mask
);
3384 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3385 /* if size can vary use size else just use PAGE_SIZE */
3388 /* Even if we own the page, we do not use atomic_set().
3389 * This would break get_page_unless_zero() users.
3391 atomic_add(size
- 1, &page
->_count
);
3393 /* reset page count bias and offset to start of new frag */
3394 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3395 nc
->pagecnt_bias
= size
;
3399 offset
= nc
->offset
- fragsz
;
3400 if (unlikely(offset
< 0)) {
3401 page
= virt_to_page(nc
->va
);
3403 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3406 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3407 /* if size can vary use size else just use PAGE_SIZE */
3410 /* OK, page count is 0, we can safely set it */
3411 atomic_set(&page
->_count
, size
);
3413 /* reset page count bias and offset to start of new frag */
3414 nc
->pagecnt_bias
= size
;
3415 offset
= size
- fragsz
;
3419 nc
->offset
= offset
;
3421 return nc
->va
+ offset
;
3423 EXPORT_SYMBOL(__alloc_page_frag
);
3426 * Frees a page fragment allocated out of either a compound or order 0 page.
3428 void __free_page_frag(void *addr
)
3430 struct page
*page
= virt_to_head_page(addr
);
3432 if (unlikely(put_page_testzero(page
)))
3433 __free_pages_ok(page
, compound_order(page
));
3435 EXPORT_SYMBOL(__free_page_frag
);
3438 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3439 * of the current memory cgroup.
3441 * It should be used when the caller would like to use kmalloc, but since the
3442 * allocation is large, it has to fall back to the page allocator.
3444 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3448 page
= alloc_pages(gfp_mask
, order
);
3449 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3450 __free_pages(page
, order
);
3456 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3460 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3461 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3462 __free_pages(page
, order
);
3469 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3472 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3474 memcg_kmem_uncharge(page
, order
);
3475 __free_pages(page
, order
);
3478 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3481 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3482 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3486 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3490 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3491 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3493 split_page(virt_to_page((void *)addr
), order
);
3494 while (used
< alloc_end
) {
3499 return (void *)addr
;
3503 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3504 * @size: the number of bytes to allocate
3505 * @gfp_mask: GFP flags for the allocation
3507 * This function is similar to alloc_pages(), except that it allocates the
3508 * minimum number of pages to satisfy the request. alloc_pages() can only
3509 * allocate memory in power-of-two pages.
3511 * This function is also limited by MAX_ORDER.
3513 * Memory allocated by this function must be released by free_pages_exact().
3515 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3517 unsigned int order
= get_order(size
);
3520 addr
= __get_free_pages(gfp_mask
, order
);
3521 return make_alloc_exact(addr
, order
, size
);
3523 EXPORT_SYMBOL(alloc_pages_exact
);
3526 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3528 * @nid: the preferred node ID where memory should be allocated
3529 * @size: the number of bytes to allocate
3530 * @gfp_mask: GFP flags for the allocation
3532 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3535 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3537 unsigned int order
= get_order(size
);
3538 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3541 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3545 * free_pages_exact - release memory allocated via alloc_pages_exact()
3546 * @virt: the value returned by alloc_pages_exact.
3547 * @size: size of allocation, same value as passed to alloc_pages_exact().
3549 * Release the memory allocated by a previous call to alloc_pages_exact.
3551 void free_pages_exact(void *virt
, size_t size
)
3553 unsigned long addr
= (unsigned long)virt
;
3554 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3556 while (addr
< end
) {
3561 EXPORT_SYMBOL(free_pages_exact
);
3564 * nr_free_zone_pages - count number of pages beyond high watermark
3565 * @offset: The zone index of the highest zone
3567 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3568 * high watermark within all zones at or below a given zone index. For each
3569 * zone, the number of pages is calculated as:
3570 * managed_pages - high_pages
3572 static unsigned long nr_free_zone_pages(int offset
)
3577 /* Just pick one node, since fallback list is circular */
3578 unsigned long sum
= 0;
3580 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3582 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3583 unsigned long size
= zone
->managed_pages
;
3584 unsigned long high
= high_wmark_pages(zone
);
3593 * nr_free_buffer_pages - count number of pages beyond high watermark
3595 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3596 * watermark within ZONE_DMA and ZONE_NORMAL.
3598 unsigned long nr_free_buffer_pages(void)
3600 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3602 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3605 * nr_free_pagecache_pages - count number of pages beyond high watermark
3607 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3608 * high watermark within all zones.
3610 unsigned long nr_free_pagecache_pages(void)
3612 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3615 static inline void show_node(struct zone
*zone
)
3617 if (IS_ENABLED(CONFIG_NUMA
))
3618 printk("Node %d ", zone_to_nid(zone
));
3621 void si_meminfo(struct sysinfo
*val
)
3623 val
->totalram
= totalram_pages
;
3624 val
->sharedram
= global_page_state(NR_SHMEM
);
3625 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3626 val
->bufferram
= nr_blockdev_pages();
3627 val
->totalhigh
= totalhigh_pages
;
3628 val
->freehigh
= nr_free_highpages();
3629 val
->mem_unit
= PAGE_SIZE
;
3632 EXPORT_SYMBOL(si_meminfo
);
3635 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3637 int zone_type
; /* needs to be signed */
3638 unsigned long managed_pages
= 0;
3639 pg_data_t
*pgdat
= NODE_DATA(nid
);
3641 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3642 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3643 val
->totalram
= managed_pages
;
3644 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3645 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3646 #ifdef CONFIG_HIGHMEM
3647 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3648 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3654 val
->mem_unit
= PAGE_SIZE
;
3659 * Determine whether the node should be displayed or not, depending on whether
3660 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3662 bool skip_free_areas_node(unsigned int flags
, int nid
)
3665 unsigned int cpuset_mems_cookie
;
3667 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3671 cpuset_mems_cookie
= read_mems_allowed_begin();
3672 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3673 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3678 #define K(x) ((x) << (PAGE_SHIFT-10))
3680 static void show_migration_types(unsigned char type
)
3682 static const char types
[MIGRATE_TYPES
] = {
3683 [MIGRATE_UNMOVABLE
] = 'U',
3684 [MIGRATE_MOVABLE
] = 'M',
3685 [MIGRATE_RECLAIMABLE
] = 'E',
3686 [MIGRATE_HIGHATOMIC
] = 'H',
3688 [MIGRATE_CMA
] = 'C',
3690 #ifdef CONFIG_MEMORY_ISOLATION
3691 [MIGRATE_ISOLATE
] = 'I',
3694 char tmp
[MIGRATE_TYPES
+ 1];
3698 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3699 if (type
& (1 << i
))
3704 printk("(%s) ", tmp
);
3708 * Show free area list (used inside shift_scroll-lock stuff)
3709 * We also calculate the percentage fragmentation. We do this by counting the
3710 * memory on each free list with the exception of the first item on the list.
3713 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3716 void show_free_areas(unsigned int filter
)
3718 unsigned long free_pcp
= 0;
3722 for_each_populated_zone(zone
) {
3723 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3726 for_each_online_cpu(cpu
)
3727 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3730 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3731 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3732 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3733 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3734 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3735 " free:%lu free_pcp:%lu free_cma:%lu\n",
3736 global_page_state(NR_ACTIVE_ANON
),
3737 global_page_state(NR_INACTIVE_ANON
),
3738 global_page_state(NR_ISOLATED_ANON
),
3739 global_page_state(NR_ACTIVE_FILE
),
3740 global_page_state(NR_INACTIVE_FILE
),
3741 global_page_state(NR_ISOLATED_FILE
),
3742 global_page_state(NR_UNEVICTABLE
),
3743 global_page_state(NR_FILE_DIRTY
),
3744 global_page_state(NR_WRITEBACK
),
3745 global_page_state(NR_UNSTABLE_NFS
),
3746 global_page_state(NR_SLAB_RECLAIMABLE
),
3747 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3748 global_page_state(NR_FILE_MAPPED
),
3749 global_page_state(NR_SHMEM
),
3750 global_page_state(NR_PAGETABLE
),
3751 global_page_state(NR_BOUNCE
),
3752 global_page_state(NR_FREE_PAGES
),
3754 global_page_state(NR_FREE_CMA_PAGES
));
3756 for_each_populated_zone(zone
) {
3759 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3763 for_each_online_cpu(cpu
)
3764 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3772 " active_anon:%lukB"
3773 " inactive_anon:%lukB"
3774 " active_file:%lukB"
3775 " inactive_file:%lukB"
3776 " unevictable:%lukB"
3777 " isolated(anon):%lukB"
3778 " isolated(file):%lukB"
3786 " slab_reclaimable:%lukB"
3787 " slab_unreclaimable:%lukB"
3788 " kernel_stack:%lukB"
3795 " writeback_tmp:%lukB"
3796 " pages_scanned:%lu"
3797 " all_unreclaimable? %s"
3800 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3801 K(min_wmark_pages(zone
)),
3802 K(low_wmark_pages(zone
)),
3803 K(high_wmark_pages(zone
)),
3804 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3805 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3806 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3807 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3808 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3809 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3810 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3811 K(zone
->present_pages
),
3812 K(zone
->managed_pages
),
3813 K(zone_page_state(zone
, NR_MLOCK
)),
3814 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3815 K(zone_page_state(zone
, NR_WRITEBACK
)),
3816 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3817 K(zone_page_state(zone
, NR_SHMEM
)),
3818 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3819 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3820 zone_page_state(zone
, NR_KERNEL_STACK
) *
3822 K(zone_page_state(zone
, NR_PAGETABLE
)),
3823 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3824 K(zone_page_state(zone
, NR_BOUNCE
)),
3826 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3827 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3828 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3829 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3830 (!zone_reclaimable(zone
) ? "yes" : "no")
3832 printk("lowmem_reserve[]:");
3833 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3834 printk(" %ld", zone
->lowmem_reserve
[i
]);
3838 for_each_populated_zone(zone
) {
3840 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
3841 unsigned char types
[MAX_ORDER
];
3843 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3846 printk("%s: ", zone
->name
);
3848 spin_lock_irqsave(&zone
->lock
, flags
);
3849 for (order
= 0; order
< MAX_ORDER
; order
++) {
3850 struct free_area
*area
= &zone
->free_area
[order
];
3853 nr
[order
] = area
->nr_free
;
3854 total
+= nr
[order
] << order
;
3857 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3858 if (!list_empty(&area
->free_list
[type
]))
3859 types
[order
] |= 1 << type
;
3862 spin_unlock_irqrestore(&zone
->lock
, flags
);
3863 for (order
= 0; order
< MAX_ORDER
; order
++) {
3864 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3866 show_migration_types(types
[order
]);
3868 printk("= %lukB\n", K(total
));
3871 hugetlb_show_meminfo();
3873 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3875 show_swap_cache_info();
3878 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3880 zoneref
->zone
= zone
;
3881 zoneref
->zone_idx
= zone_idx(zone
);
3885 * Builds allocation fallback zone lists.
3887 * Add all populated zones of a node to the zonelist.
3889 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3893 enum zone_type zone_type
= MAX_NR_ZONES
;
3897 zone
= pgdat
->node_zones
+ zone_type
;
3898 if (populated_zone(zone
)) {
3899 zoneref_set_zone(zone
,
3900 &zonelist
->_zonerefs
[nr_zones
++]);
3901 check_highest_zone(zone_type
);
3903 } while (zone_type
);
3911 * 0 = automatic detection of better ordering.
3912 * 1 = order by ([node] distance, -zonetype)
3913 * 2 = order by (-zonetype, [node] distance)
3915 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3916 * the same zonelist. So only NUMA can configure this param.
3918 #define ZONELIST_ORDER_DEFAULT 0
3919 #define ZONELIST_ORDER_NODE 1
3920 #define ZONELIST_ORDER_ZONE 2
3922 /* zonelist order in the kernel.
3923 * set_zonelist_order() will set this to NODE or ZONE.
3925 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3926 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3930 /* The value user specified ....changed by config */
3931 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3932 /* string for sysctl */
3933 #define NUMA_ZONELIST_ORDER_LEN 16
3934 char numa_zonelist_order
[16] = "default";
3937 * interface for configure zonelist ordering.
3938 * command line option "numa_zonelist_order"
3939 * = "[dD]efault - default, automatic configuration.
3940 * = "[nN]ode - order by node locality, then by zone within node
3941 * = "[zZ]one - order by zone, then by locality within zone
3944 static int __parse_numa_zonelist_order(char *s
)
3946 if (*s
== 'd' || *s
== 'D') {
3947 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3948 } else if (*s
== 'n' || *s
== 'N') {
3949 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3950 } else if (*s
== 'z' || *s
== 'Z') {
3951 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3954 "Ignoring invalid numa_zonelist_order value: "
3961 static __init
int setup_numa_zonelist_order(char *s
)
3968 ret
= __parse_numa_zonelist_order(s
);
3970 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3974 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3977 * sysctl handler for numa_zonelist_order
3979 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3980 void __user
*buffer
, size_t *length
,
3983 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3985 static DEFINE_MUTEX(zl_order_mutex
);
3987 mutex_lock(&zl_order_mutex
);
3989 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3993 strcpy(saved_string
, (char *)table
->data
);
3995 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3999 int oldval
= user_zonelist_order
;
4001 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4004 * bogus value. restore saved string
4006 strncpy((char *)table
->data
, saved_string
,
4007 NUMA_ZONELIST_ORDER_LEN
);
4008 user_zonelist_order
= oldval
;
4009 } else if (oldval
!= user_zonelist_order
) {
4010 mutex_lock(&zonelists_mutex
);
4011 build_all_zonelists(NULL
, NULL
);
4012 mutex_unlock(&zonelists_mutex
);
4016 mutex_unlock(&zl_order_mutex
);
4021 #define MAX_NODE_LOAD (nr_online_nodes)
4022 static int node_load
[MAX_NUMNODES
];
4025 * find_next_best_node - find the next node that should appear in a given node's fallback list
4026 * @node: node whose fallback list we're appending
4027 * @used_node_mask: nodemask_t of already used nodes
4029 * We use a number of factors to determine which is the next node that should
4030 * appear on a given node's fallback list. The node should not have appeared
4031 * already in @node's fallback list, and it should be the next closest node
4032 * according to the distance array (which contains arbitrary distance values
4033 * from each node to each node in the system), and should also prefer nodes
4034 * with no CPUs, since presumably they'll have very little allocation pressure
4035 * on them otherwise.
4036 * It returns -1 if no node is found.
4038 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4041 int min_val
= INT_MAX
;
4042 int best_node
= NUMA_NO_NODE
;
4043 const struct cpumask
*tmp
= cpumask_of_node(0);
4045 /* Use the local node if we haven't already */
4046 if (!node_isset(node
, *used_node_mask
)) {
4047 node_set(node
, *used_node_mask
);
4051 for_each_node_state(n
, N_MEMORY
) {
4053 /* Don't want a node to appear more than once */
4054 if (node_isset(n
, *used_node_mask
))
4057 /* Use the distance array to find the distance */
4058 val
= node_distance(node
, n
);
4060 /* Penalize nodes under us ("prefer the next node") */
4063 /* Give preference to headless and unused nodes */
4064 tmp
= cpumask_of_node(n
);
4065 if (!cpumask_empty(tmp
))
4066 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4068 /* Slight preference for less loaded node */
4069 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4070 val
+= node_load
[n
];
4072 if (val
< min_val
) {
4079 node_set(best_node
, *used_node_mask
);
4086 * Build zonelists ordered by node and zones within node.
4087 * This results in maximum locality--normal zone overflows into local
4088 * DMA zone, if any--but risks exhausting DMA zone.
4090 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4093 struct zonelist
*zonelist
;
4095 zonelist
= &pgdat
->node_zonelists
[0];
4096 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4098 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4099 zonelist
->_zonerefs
[j
].zone
= NULL
;
4100 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4104 * Build gfp_thisnode zonelists
4106 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4109 struct zonelist
*zonelist
;
4111 zonelist
= &pgdat
->node_zonelists
[1];
4112 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4113 zonelist
->_zonerefs
[j
].zone
= NULL
;
4114 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4118 * Build zonelists ordered by zone and nodes within zones.
4119 * This results in conserving DMA zone[s] until all Normal memory is
4120 * exhausted, but results in overflowing to remote node while memory
4121 * may still exist in local DMA zone.
4123 static int node_order
[MAX_NUMNODES
];
4125 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4128 int zone_type
; /* needs to be signed */
4130 struct zonelist
*zonelist
;
4132 zonelist
= &pgdat
->node_zonelists
[0];
4134 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4135 for (j
= 0; j
< nr_nodes
; j
++) {
4136 node
= node_order
[j
];
4137 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4138 if (populated_zone(z
)) {
4140 &zonelist
->_zonerefs
[pos
++]);
4141 check_highest_zone(zone_type
);
4145 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4146 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4149 #if defined(CONFIG_64BIT)
4151 * Devices that require DMA32/DMA are relatively rare and do not justify a
4152 * penalty to every machine in case the specialised case applies. Default
4153 * to Node-ordering on 64-bit NUMA machines
4155 static int default_zonelist_order(void)
4157 return ZONELIST_ORDER_NODE
;
4161 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4162 * by the kernel. If processes running on node 0 deplete the low memory zone
4163 * then reclaim will occur more frequency increasing stalls and potentially
4164 * be easier to OOM if a large percentage of the zone is under writeback or
4165 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4166 * Hence, default to zone ordering on 32-bit.
4168 static int default_zonelist_order(void)
4170 return ZONELIST_ORDER_ZONE
;
4172 #endif /* CONFIG_64BIT */
4174 static void set_zonelist_order(void)
4176 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4177 current_zonelist_order
= default_zonelist_order();
4179 current_zonelist_order
= user_zonelist_order
;
4182 static void build_zonelists(pg_data_t
*pgdat
)
4186 nodemask_t used_mask
;
4187 int local_node
, prev_node
;
4188 struct zonelist
*zonelist
;
4189 unsigned int order
= current_zonelist_order
;
4191 /* initialize zonelists */
4192 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4193 zonelist
= pgdat
->node_zonelists
+ i
;
4194 zonelist
->_zonerefs
[0].zone
= NULL
;
4195 zonelist
->_zonerefs
[0].zone_idx
= 0;
4198 /* NUMA-aware ordering of nodes */
4199 local_node
= pgdat
->node_id
;
4200 load
= nr_online_nodes
;
4201 prev_node
= local_node
;
4202 nodes_clear(used_mask
);
4204 memset(node_order
, 0, sizeof(node_order
));
4207 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4209 * We don't want to pressure a particular node.
4210 * So adding penalty to the first node in same
4211 * distance group to make it round-robin.
4213 if (node_distance(local_node
, node
) !=
4214 node_distance(local_node
, prev_node
))
4215 node_load
[node
] = load
;
4219 if (order
== ZONELIST_ORDER_NODE
)
4220 build_zonelists_in_node_order(pgdat
, node
);
4222 node_order
[j
++] = node
; /* remember order */
4225 if (order
== ZONELIST_ORDER_ZONE
) {
4226 /* calculate node order -- i.e., DMA last! */
4227 build_zonelists_in_zone_order(pgdat
, j
);
4230 build_thisnode_zonelists(pgdat
);
4233 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4235 * Return node id of node used for "local" allocations.
4236 * I.e., first node id of first zone in arg node's generic zonelist.
4237 * Used for initializing percpu 'numa_mem', which is used primarily
4238 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4240 int local_memory_node(int node
)
4244 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4245 gfp_zone(GFP_KERNEL
),
4252 #else /* CONFIG_NUMA */
4254 static void set_zonelist_order(void)
4256 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4259 static void build_zonelists(pg_data_t
*pgdat
)
4261 int node
, local_node
;
4263 struct zonelist
*zonelist
;
4265 local_node
= pgdat
->node_id
;
4267 zonelist
= &pgdat
->node_zonelists
[0];
4268 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4271 * Now we build the zonelist so that it contains the zones
4272 * of all the other nodes.
4273 * We don't want to pressure a particular node, so when
4274 * building the zones for node N, we make sure that the
4275 * zones coming right after the local ones are those from
4276 * node N+1 (modulo N)
4278 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4279 if (!node_online(node
))
4281 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4283 for (node
= 0; node
< local_node
; node
++) {
4284 if (!node_online(node
))
4286 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4289 zonelist
->_zonerefs
[j
].zone
= NULL
;
4290 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4293 #endif /* CONFIG_NUMA */
4296 * Boot pageset table. One per cpu which is going to be used for all
4297 * zones and all nodes. The parameters will be set in such a way
4298 * that an item put on a list will immediately be handed over to
4299 * the buddy list. This is safe since pageset manipulation is done
4300 * with interrupts disabled.
4302 * The boot_pagesets must be kept even after bootup is complete for
4303 * unused processors and/or zones. They do play a role for bootstrapping
4304 * hotplugged processors.
4306 * zoneinfo_show() and maybe other functions do
4307 * not check if the processor is online before following the pageset pointer.
4308 * Other parts of the kernel may not check if the zone is available.
4310 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4311 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4312 static void setup_zone_pageset(struct zone
*zone
);
4315 * Global mutex to protect against size modification of zonelists
4316 * as well as to serialize pageset setup for the new populated zone.
4318 DEFINE_MUTEX(zonelists_mutex
);
4320 /* return values int ....just for stop_machine() */
4321 static int __build_all_zonelists(void *data
)
4325 pg_data_t
*self
= data
;
4328 memset(node_load
, 0, sizeof(node_load
));
4331 if (self
&& !node_online(self
->node_id
)) {
4332 build_zonelists(self
);
4335 for_each_online_node(nid
) {
4336 pg_data_t
*pgdat
= NODE_DATA(nid
);
4338 build_zonelists(pgdat
);
4342 * Initialize the boot_pagesets that are going to be used
4343 * for bootstrapping processors. The real pagesets for
4344 * each zone will be allocated later when the per cpu
4345 * allocator is available.
4347 * boot_pagesets are used also for bootstrapping offline
4348 * cpus if the system is already booted because the pagesets
4349 * are needed to initialize allocators on a specific cpu too.
4350 * F.e. the percpu allocator needs the page allocator which
4351 * needs the percpu allocator in order to allocate its pagesets
4352 * (a chicken-egg dilemma).
4354 for_each_possible_cpu(cpu
) {
4355 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4357 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4359 * We now know the "local memory node" for each node--
4360 * i.e., the node of the first zone in the generic zonelist.
4361 * Set up numa_mem percpu variable for on-line cpus. During
4362 * boot, only the boot cpu should be on-line; we'll init the
4363 * secondary cpus' numa_mem as they come on-line. During
4364 * node/memory hotplug, we'll fixup all on-line cpus.
4366 if (cpu_online(cpu
))
4367 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4374 static noinline
void __init
4375 build_all_zonelists_init(void)
4377 __build_all_zonelists(NULL
);
4378 mminit_verify_zonelist();
4379 cpuset_init_current_mems_allowed();
4383 * Called with zonelists_mutex held always
4384 * unless system_state == SYSTEM_BOOTING.
4386 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4387 * [we're only called with non-NULL zone through __meminit paths] and
4388 * (2) call of __init annotated helper build_all_zonelists_init
4389 * [protected by SYSTEM_BOOTING].
4391 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4393 set_zonelist_order();
4395 if (system_state
== SYSTEM_BOOTING
) {
4396 build_all_zonelists_init();
4398 #ifdef CONFIG_MEMORY_HOTPLUG
4400 setup_zone_pageset(zone
);
4402 /* we have to stop all cpus to guarantee there is no user
4404 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4405 /* cpuset refresh routine should be here */
4407 vm_total_pages
= nr_free_pagecache_pages();
4409 * Disable grouping by mobility if the number of pages in the
4410 * system is too low to allow the mechanism to work. It would be
4411 * more accurate, but expensive to check per-zone. This check is
4412 * made on memory-hotadd so a system can start with mobility
4413 * disabled and enable it later
4415 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4416 page_group_by_mobility_disabled
= 1;
4418 page_group_by_mobility_disabled
= 0;
4420 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4421 "Total pages: %ld\n",
4423 zonelist_order_name
[current_zonelist_order
],
4424 page_group_by_mobility_disabled
? "off" : "on",
4427 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4432 * Helper functions to size the waitqueue hash table.
4433 * Essentially these want to choose hash table sizes sufficiently
4434 * large so that collisions trying to wait on pages are rare.
4435 * But in fact, the number of active page waitqueues on typical
4436 * systems is ridiculously low, less than 200. So this is even
4437 * conservative, even though it seems large.
4439 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4440 * waitqueues, i.e. the size of the waitq table given the number of pages.
4442 #define PAGES_PER_WAITQUEUE 256
4444 #ifndef CONFIG_MEMORY_HOTPLUG
4445 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4447 unsigned long size
= 1;
4449 pages
/= PAGES_PER_WAITQUEUE
;
4451 while (size
< pages
)
4455 * Once we have dozens or even hundreds of threads sleeping
4456 * on IO we've got bigger problems than wait queue collision.
4457 * Limit the size of the wait table to a reasonable size.
4459 size
= min(size
, 4096UL);
4461 return max(size
, 4UL);
4465 * A zone's size might be changed by hot-add, so it is not possible to determine
4466 * a suitable size for its wait_table. So we use the maximum size now.
4468 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4470 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4471 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4472 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4474 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4475 * or more by the traditional way. (See above). It equals:
4477 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4478 * ia64(16K page size) : = ( 8G + 4M)byte.
4479 * powerpc (64K page size) : = (32G +16M)byte.
4481 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4488 * This is an integer logarithm so that shifts can be used later
4489 * to extract the more random high bits from the multiplicative
4490 * hash function before the remainder is taken.
4492 static inline unsigned long wait_table_bits(unsigned long size
)
4498 * Initially all pages are reserved - free ones are freed
4499 * up by free_all_bootmem() once the early boot process is
4500 * done. Non-atomic initialization, single-pass.
4502 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4503 unsigned long start_pfn
, enum memmap_context context
)
4505 pg_data_t
*pgdat
= NODE_DATA(nid
);
4506 unsigned long end_pfn
= start_pfn
+ size
;
4509 unsigned long nr_initialised
= 0;
4511 if (highest_memmap_pfn
< end_pfn
- 1)
4512 highest_memmap_pfn
= end_pfn
- 1;
4514 z
= &pgdat
->node_zones
[zone
];
4515 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4517 * There can be holes in boot-time mem_map[]s
4518 * handed to this function. They do not
4519 * exist on hotplugged memory.
4521 if (context
== MEMMAP_EARLY
) {
4522 if (!early_pfn_valid(pfn
))
4524 if (!early_pfn_in_nid(pfn
, nid
))
4526 if (!update_defer_init(pgdat
, pfn
, end_pfn
,
4532 * Mark the block movable so that blocks are reserved for
4533 * movable at startup. This will force kernel allocations
4534 * to reserve their blocks rather than leaking throughout
4535 * the address space during boot when many long-lived
4536 * kernel allocations are made.
4538 * bitmap is created for zone's valid pfn range. but memmap
4539 * can be created for invalid pages (for alignment)
4540 * check here not to call set_pageblock_migratetype() against
4543 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4544 struct page
*page
= pfn_to_page(pfn
);
4546 __init_single_page(page
, pfn
, zone
, nid
);
4547 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4549 __init_single_pfn(pfn
, zone
, nid
);
4554 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4556 unsigned int order
, t
;
4557 for_each_migratetype_order(order
, t
) {
4558 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4559 zone
->free_area
[order
].nr_free
= 0;
4563 #ifndef __HAVE_ARCH_MEMMAP_INIT
4564 #define memmap_init(size, nid, zone, start_pfn) \
4565 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4568 static int zone_batchsize(struct zone
*zone
)
4574 * The per-cpu-pages pools are set to around 1000th of the
4575 * size of the zone. But no more than 1/2 of a meg.
4577 * OK, so we don't know how big the cache is. So guess.
4579 batch
= zone
->managed_pages
/ 1024;
4580 if (batch
* PAGE_SIZE
> 512 * 1024)
4581 batch
= (512 * 1024) / PAGE_SIZE
;
4582 batch
/= 4; /* We effectively *= 4 below */
4587 * Clamp the batch to a 2^n - 1 value. Having a power
4588 * of 2 value was found to be more likely to have
4589 * suboptimal cache aliasing properties in some cases.
4591 * For example if 2 tasks are alternately allocating
4592 * batches of pages, one task can end up with a lot
4593 * of pages of one half of the possible page colors
4594 * and the other with pages of the other colors.
4596 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4601 /* The deferral and batching of frees should be suppressed under NOMMU
4604 * The problem is that NOMMU needs to be able to allocate large chunks
4605 * of contiguous memory as there's no hardware page translation to
4606 * assemble apparent contiguous memory from discontiguous pages.
4608 * Queueing large contiguous runs of pages for batching, however,
4609 * causes the pages to actually be freed in smaller chunks. As there
4610 * can be a significant delay between the individual batches being
4611 * recycled, this leads to the once large chunks of space being
4612 * fragmented and becoming unavailable for high-order allocations.
4619 * pcp->high and pcp->batch values are related and dependent on one another:
4620 * ->batch must never be higher then ->high.
4621 * The following function updates them in a safe manner without read side
4624 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4625 * those fields changing asynchronously (acording the the above rule).
4627 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4628 * outside of boot time (or some other assurance that no concurrent updaters
4631 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4632 unsigned long batch
)
4634 /* start with a fail safe value for batch */
4638 /* Update high, then batch, in order */
4645 /* a companion to pageset_set_high() */
4646 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4648 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4651 static void pageset_init(struct per_cpu_pageset
*p
)
4653 struct per_cpu_pages
*pcp
;
4656 memset(p
, 0, sizeof(*p
));
4660 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4661 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4664 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4667 pageset_set_batch(p
, batch
);
4671 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4672 * to the value high for the pageset p.
4674 static void pageset_set_high(struct per_cpu_pageset
*p
,
4677 unsigned long batch
= max(1UL, high
/ 4);
4678 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4679 batch
= PAGE_SHIFT
* 8;
4681 pageset_update(&p
->pcp
, high
, batch
);
4684 static void pageset_set_high_and_batch(struct zone
*zone
,
4685 struct per_cpu_pageset
*pcp
)
4687 if (percpu_pagelist_fraction
)
4688 pageset_set_high(pcp
,
4689 (zone
->managed_pages
/
4690 percpu_pagelist_fraction
));
4692 pageset_set_batch(pcp
, zone_batchsize(zone
));
4695 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4697 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4700 pageset_set_high_and_batch(zone
, pcp
);
4703 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4706 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4707 for_each_possible_cpu(cpu
)
4708 zone_pageset_init(zone
, cpu
);
4712 * Allocate per cpu pagesets and initialize them.
4713 * Before this call only boot pagesets were available.
4715 void __init
setup_per_cpu_pageset(void)
4719 for_each_populated_zone(zone
)
4720 setup_zone_pageset(zone
);
4723 static noinline __init_refok
4724 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4730 * The per-page waitqueue mechanism uses hashed waitqueues
4733 zone
->wait_table_hash_nr_entries
=
4734 wait_table_hash_nr_entries(zone_size_pages
);
4735 zone
->wait_table_bits
=
4736 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4737 alloc_size
= zone
->wait_table_hash_nr_entries
4738 * sizeof(wait_queue_head_t
);
4740 if (!slab_is_available()) {
4741 zone
->wait_table
= (wait_queue_head_t
*)
4742 memblock_virt_alloc_node_nopanic(
4743 alloc_size
, zone
->zone_pgdat
->node_id
);
4746 * This case means that a zone whose size was 0 gets new memory
4747 * via memory hot-add.
4748 * But it may be the case that a new node was hot-added. In
4749 * this case vmalloc() will not be able to use this new node's
4750 * memory - this wait_table must be initialized to use this new
4751 * node itself as well.
4752 * To use this new node's memory, further consideration will be
4755 zone
->wait_table
= vmalloc(alloc_size
);
4757 if (!zone
->wait_table
)
4760 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4761 init_waitqueue_head(zone
->wait_table
+ i
);
4766 static __meminit
void zone_pcp_init(struct zone
*zone
)
4769 * per cpu subsystem is not up at this point. The following code
4770 * relies on the ability of the linker to provide the
4771 * offset of a (static) per cpu variable into the per cpu area.
4773 zone
->pageset
= &boot_pageset
;
4775 if (populated_zone(zone
))
4776 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4777 zone
->name
, zone
->present_pages
,
4778 zone_batchsize(zone
));
4781 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4782 unsigned long zone_start_pfn
,
4785 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4787 ret
= zone_wait_table_init(zone
, size
);
4790 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4792 zone
->zone_start_pfn
= zone_start_pfn
;
4794 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4795 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4797 (unsigned long)zone_idx(zone
),
4798 zone_start_pfn
, (zone_start_pfn
+ size
));
4800 zone_init_free_lists(zone
);
4805 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4806 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4809 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4811 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4812 struct mminit_pfnnid_cache
*state
)
4814 unsigned long start_pfn
, end_pfn
;
4817 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4818 return state
->last_nid
;
4820 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4822 state
->last_start
= start_pfn
;
4823 state
->last_end
= end_pfn
;
4824 state
->last_nid
= nid
;
4829 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4832 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4833 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4834 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4836 * If an architecture guarantees that all ranges registered contain no holes
4837 * and may be freed, this this function may be used instead of calling
4838 * memblock_free_early_nid() manually.
4840 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4842 unsigned long start_pfn
, end_pfn
;
4845 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4846 start_pfn
= min(start_pfn
, max_low_pfn
);
4847 end_pfn
= min(end_pfn
, max_low_pfn
);
4849 if (start_pfn
< end_pfn
)
4850 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4851 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4857 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4858 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4860 * If an architecture guarantees that all ranges registered contain no holes and may
4861 * be freed, this function may be used instead of calling memory_present() manually.
4863 void __init
sparse_memory_present_with_active_regions(int nid
)
4865 unsigned long start_pfn
, end_pfn
;
4868 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4869 memory_present(this_nid
, start_pfn
, end_pfn
);
4873 * get_pfn_range_for_nid - Return the start and end page frames for a node
4874 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4875 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4876 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4878 * It returns the start and end page frame of a node based on information
4879 * provided by memblock_set_node(). If called for a node
4880 * with no available memory, a warning is printed and the start and end
4883 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4884 unsigned long *start_pfn
, unsigned long *end_pfn
)
4886 unsigned long this_start_pfn
, this_end_pfn
;
4892 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4893 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4894 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4897 if (*start_pfn
== -1UL)
4902 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4903 * assumption is made that zones within a node are ordered in monotonic
4904 * increasing memory addresses so that the "highest" populated zone is used
4906 static void __init
find_usable_zone_for_movable(void)
4909 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4910 if (zone_index
== ZONE_MOVABLE
)
4913 if (arch_zone_highest_possible_pfn
[zone_index
] >
4914 arch_zone_lowest_possible_pfn
[zone_index
])
4918 VM_BUG_ON(zone_index
== -1);
4919 movable_zone
= zone_index
;
4923 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4924 * because it is sized independent of architecture. Unlike the other zones,
4925 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4926 * in each node depending on the size of each node and how evenly kernelcore
4927 * is distributed. This helper function adjusts the zone ranges
4928 * provided by the architecture for a given node by using the end of the
4929 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4930 * zones within a node are in order of monotonic increases memory addresses
4932 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4933 unsigned long zone_type
,
4934 unsigned long node_start_pfn
,
4935 unsigned long node_end_pfn
,
4936 unsigned long *zone_start_pfn
,
4937 unsigned long *zone_end_pfn
)
4939 /* Only adjust if ZONE_MOVABLE is on this node */
4940 if (zone_movable_pfn
[nid
]) {
4941 /* Size ZONE_MOVABLE */
4942 if (zone_type
== ZONE_MOVABLE
) {
4943 *zone_start_pfn
= zone_movable_pfn
[nid
];
4944 *zone_end_pfn
= min(node_end_pfn
,
4945 arch_zone_highest_possible_pfn
[movable_zone
]);
4947 /* Adjust for ZONE_MOVABLE starting within this range */
4948 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4949 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4950 *zone_end_pfn
= zone_movable_pfn
[nid
];
4952 /* Check if this whole range is within ZONE_MOVABLE */
4953 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4954 *zone_start_pfn
= *zone_end_pfn
;
4959 * Return the number of pages a zone spans in a node, including holes
4960 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4962 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4963 unsigned long zone_type
,
4964 unsigned long node_start_pfn
,
4965 unsigned long node_end_pfn
,
4966 unsigned long *ignored
)
4968 unsigned long zone_start_pfn
, zone_end_pfn
;
4970 /* When hotadd a new node from cpu_up(), the node should be empty */
4971 if (!node_start_pfn
&& !node_end_pfn
)
4974 /* Get the start and end of the zone */
4975 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4976 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4977 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4978 node_start_pfn
, node_end_pfn
,
4979 &zone_start_pfn
, &zone_end_pfn
);
4981 /* Check that this node has pages within the zone's required range */
4982 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4985 /* Move the zone boundaries inside the node if necessary */
4986 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4987 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4989 /* Return the spanned pages */
4990 return zone_end_pfn
- zone_start_pfn
;
4994 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4995 * then all holes in the requested range will be accounted for.
4997 unsigned long __meminit
__absent_pages_in_range(int nid
,
4998 unsigned long range_start_pfn
,
4999 unsigned long range_end_pfn
)
5001 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5002 unsigned long start_pfn
, end_pfn
;
5005 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5006 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5007 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5008 nr_absent
-= end_pfn
- start_pfn
;
5014 * absent_pages_in_range - Return number of page frames in holes within a range
5015 * @start_pfn: The start PFN to start searching for holes
5016 * @end_pfn: The end PFN to stop searching for holes
5018 * It returns the number of pages frames in memory holes within a range.
5020 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5021 unsigned long end_pfn
)
5023 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5026 /* Return the number of page frames in holes in a zone on a node */
5027 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5028 unsigned long zone_type
,
5029 unsigned long node_start_pfn
,
5030 unsigned long node_end_pfn
,
5031 unsigned long *ignored
)
5033 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5034 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5035 unsigned long zone_start_pfn
, zone_end_pfn
;
5037 /* When hotadd a new node from cpu_up(), the node should be empty */
5038 if (!node_start_pfn
&& !node_end_pfn
)
5041 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5042 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5044 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5045 node_start_pfn
, node_end_pfn
,
5046 &zone_start_pfn
, &zone_end_pfn
);
5047 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5050 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5051 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5052 unsigned long zone_type
,
5053 unsigned long node_start_pfn
,
5054 unsigned long node_end_pfn
,
5055 unsigned long *zones_size
)
5057 return zones_size
[zone_type
];
5060 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5061 unsigned long zone_type
,
5062 unsigned long node_start_pfn
,
5063 unsigned long node_end_pfn
,
5064 unsigned long *zholes_size
)
5069 return zholes_size
[zone_type
];
5072 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5074 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5075 unsigned long node_start_pfn
,
5076 unsigned long node_end_pfn
,
5077 unsigned long *zones_size
,
5078 unsigned long *zholes_size
)
5080 unsigned long realtotalpages
= 0, totalpages
= 0;
5083 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5084 struct zone
*zone
= pgdat
->node_zones
+ i
;
5085 unsigned long size
, real_size
;
5087 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5091 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5092 node_start_pfn
, node_end_pfn
,
5094 zone
->spanned_pages
= size
;
5095 zone
->present_pages
= real_size
;
5098 realtotalpages
+= real_size
;
5101 pgdat
->node_spanned_pages
= totalpages
;
5102 pgdat
->node_present_pages
= realtotalpages
;
5103 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5107 #ifndef CONFIG_SPARSEMEM
5109 * Calculate the size of the zone->blockflags rounded to an unsigned long
5110 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5111 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5112 * round what is now in bits to nearest long in bits, then return it in
5115 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5117 unsigned long usemapsize
;
5119 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5120 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5121 usemapsize
= usemapsize
>> pageblock_order
;
5122 usemapsize
*= NR_PAGEBLOCK_BITS
;
5123 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5125 return usemapsize
/ 8;
5128 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5130 unsigned long zone_start_pfn
,
5131 unsigned long zonesize
)
5133 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5134 zone
->pageblock_flags
= NULL
;
5136 zone
->pageblock_flags
=
5137 memblock_virt_alloc_node_nopanic(usemapsize
,
5141 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5142 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5143 #endif /* CONFIG_SPARSEMEM */
5145 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5147 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5148 void __paginginit
set_pageblock_order(void)
5152 /* Check that pageblock_nr_pages has not already been setup */
5153 if (pageblock_order
)
5156 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5157 order
= HUGETLB_PAGE_ORDER
;
5159 order
= MAX_ORDER
- 1;
5162 * Assume the largest contiguous order of interest is a huge page.
5163 * This value may be variable depending on boot parameters on IA64 and
5166 pageblock_order
= order
;
5168 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5171 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5172 * is unused as pageblock_order is set at compile-time. See
5173 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5176 void __paginginit
set_pageblock_order(void)
5180 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5182 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5183 unsigned long present_pages
)
5185 unsigned long pages
= spanned_pages
;
5188 * Provide a more accurate estimation if there are holes within
5189 * the zone and SPARSEMEM is in use. If there are holes within the
5190 * zone, each populated memory region may cost us one or two extra
5191 * memmap pages due to alignment because memmap pages for each
5192 * populated regions may not naturally algined on page boundary.
5193 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5195 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5196 IS_ENABLED(CONFIG_SPARSEMEM
))
5197 pages
= present_pages
;
5199 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5203 * Set up the zone data structures:
5204 * - mark all pages reserved
5205 * - mark all memory queues empty
5206 * - clear the memory bitmaps
5208 * NOTE: pgdat should get zeroed by caller.
5210 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5213 int nid
= pgdat
->node_id
;
5214 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5217 pgdat_resize_init(pgdat
);
5218 #ifdef CONFIG_NUMA_BALANCING
5219 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5220 pgdat
->numabalancing_migrate_nr_pages
= 0;
5221 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5223 init_waitqueue_head(&pgdat
->kswapd_wait
);
5224 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5225 pgdat_page_ext_init(pgdat
);
5227 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5228 struct zone
*zone
= pgdat
->node_zones
+ j
;
5229 unsigned long size
, realsize
, freesize
, memmap_pages
;
5231 size
= zone
->spanned_pages
;
5232 realsize
= freesize
= zone
->present_pages
;
5235 * Adjust freesize so that it accounts for how much memory
5236 * is used by this zone for memmap. This affects the watermark
5237 * and per-cpu initialisations
5239 memmap_pages
= calc_memmap_size(size
, realsize
);
5240 if (!is_highmem_idx(j
)) {
5241 if (freesize
>= memmap_pages
) {
5242 freesize
-= memmap_pages
;
5245 " %s zone: %lu pages used for memmap\n",
5246 zone_names
[j
], memmap_pages
);
5249 " %s zone: %lu pages exceeds freesize %lu\n",
5250 zone_names
[j
], memmap_pages
, freesize
);
5253 /* Account for reserved pages */
5254 if (j
== 0 && freesize
> dma_reserve
) {
5255 freesize
-= dma_reserve
;
5256 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5257 zone_names
[0], dma_reserve
);
5260 if (!is_highmem_idx(j
))
5261 nr_kernel_pages
+= freesize
;
5262 /* Charge for highmem memmap if there are enough kernel pages */
5263 else if (nr_kernel_pages
> memmap_pages
* 2)
5264 nr_kernel_pages
-= memmap_pages
;
5265 nr_all_pages
+= freesize
;
5268 * Set an approximate value for lowmem here, it will be adjusted
5269 * when the bootmem allocator frees pages into the buddy system.
5270 * And all highmem pages will be managed by the buddy system.
5272 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5275 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5277 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5279 zone
->name
= zone_names
[j
];
5280 spin_lock_init(&zone
->lock
);
5281 spin_lock_init(&zone
->lru_lock
);
5282 zone_seqlock_init(zone
);
5283 zone
->zone_pgdat
= pgdat
;
5284 zone_pcp_init(zone
);
5286 /* For bootup, initialized properly in watermark setup */
5287 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5289 lruvec_init(&zone
->lruvec
);
5293 set_pageblock_order();
5294 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5295 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5297 memmap_init(size
, nid
, j
, zone_start_pfn
);
5298 zone_start_pfn
+= size
;
5302 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5304 unsigned long __maybe_unused start
= 0;
5305 unsigned long __maybe_unused offset
= 0;
5307 /* Skip empty nodes */
5308 if (!pgdat
->node_spanned_pages
)
5311 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5312 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5313 offset
= pgdat
->node_start_pfn
- start
;
5314 /* ia64 gets its own node_mem_map, before this, without bootmem */
5315 if (!pgdat
->node_mem_map
) {
5316 unsigned long size
, end
;
5320 * The zone's endpoints aren't required to be MAX_ORDER
5321 * aligned but the node_mem_map endpoints must be in order
5322 * for the buddy allocator to function correctly.
5324 end
= pgdat_end_pfn(pgdat
);
5325 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5326 size
= (end
- start
) * sizeof(struct page
);
5327 map
= alloc_remap(pgdat
->node_id
, size
);
5329 map
= memblock_virt_alloc_node_nopanic(size
,
5331 pgdat
->node_mem_map
= map
+ offset
;
5333 #ifndef CONFIG_NEED_MULTIPLE_NODES
5335 * With no DISCONTIG, the global mem_map is just set as node 0's
5337 if (pgdat
== NODE_DATA(0)) {
5338 mem_map
= NODE_DATA(0)->node_mem_map
;
5339 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5340 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5342 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5345 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5348 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5349 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5351 pg_data_t
*pgdat
= NODE_DATA(nid
);
5352 unsigned long start_pfn
= 0;
5353 unsigned long end_pfn
= 0;
5355 /* pg_data_t should be reset to zero when it's allocated */
5356 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5358 reset_deferred_meminit(pgdat
);
5359 pgdat
->node_id
= nid
;
5360 pgdat
->node_start_pfn
= node_start_pfn
;
5361 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5362 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5363 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5364 (u64
)start_pfn
<< PAGE_SHIFT
,
5365 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5367 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5368 zones_size
, zholes_size
);
5370 alloc_node_mem_map(pgdat
);
5371 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5372 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5373 nid
, (unsigned long)pgdat
,
5374 (unsigned long)pgdat
->node_mem_map
);
5377 free_area_init_core(pgdat
);
5380 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5382 #if MAX_NUMNODES > 1
5384 * Figure out the number of possible node ids.
5386 void __init
setup_nr_node_ids(void)
5388 unsigned int highest
;
5390 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5391 nr_node_ids
= highest
+ 1;
5396 * node_map_pfn_alignment - determine the maximum internode alignment
5398 * This function should be called after node map is populated and sorted.
5399 * It calculates the maximum power of two alignment which can distinguish
5402 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5403 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5404 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5405 * shifted, 1GiB is enough and this function will indicate so.
5407 * This is used to test whether pfn -> nid mapping of the chosen memory
5408 * model has fine enough granularity to avoid incorrect mapping for the
5409 * populated node map.
5411 * Returns the determined alignment in pfn's. 0 if there is no alignment
5412 * requirement (single node).
5414 unsigned long __init
node_map_pfn_alignment(void)
5416 unsigned long accl_mask
= 0, last_end
= 0;
5417 unsigned long start
, end
, mask
;
5421 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5422 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5429 * Start with a mask granular enough to pin-point to the
5430 * start pfn and tick off bits one-by-one until it becomes
5431 * too coarse to separate the current node from the last.
5433 mask
= ~((1 << __ffs(start
)) - 1);
5434 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5437 /* accumulate all internode masks */
5441 /* convert mask to number of pages */
5442 return ~accl_mask
+ 1;
5445 /* Find the lowest pfn for a node */
5446 static unsigned long __init
find_min_pfn_for_node(int nid
)
5448 unsigned long min_pfn
= ULONG_MAX
;
5449 unsigned long start_pfn
;
5452 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5453 min_pfn
= min(min_pfn
, start_pfn
);
5455 if (min_pfn
== ULONG_MAX
) {
5457 "Could not find start_pfn for node %d\n", nid
);
5465 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5467 * It returns the minimum PFN based on information provided via
5468 * memblock_set_node().
5470 unsigned long __init
find_min_pfn_with_active_regions(void)
5472 return find_min_pfn_for_node(MAX_NUMNODES
);
5476 * early_calculate_totalpages()
5477 * Sum pages in active regions for movable zone.
5478 * Populate N_MEMORY for calculating usable_nodes.
5480 static unsigned long __init
early_calculate_totalpages(void)
5482 unsigned long totalpages
= 0;
5483 unsigned long start_pfn
, end_pfn
;
5486 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5487 unsigned long pages
= end_pfn
- start_pfn
;
5489 totalpages
+= pages
;
5491 node_set_state(nid
, N_MEMORY
);
5497 * Find the PFN the Movable zone begins in each node. Kernel memory
5498 * is spread evenly between nodes as long as the nodes have enough
5499 * memory. When they don't, some nodes will have more kernelcore than
5502 static void __init
find_zone_movable_pfns_for_nodes(void)
5505 unsigned long usable_startpfn
;
5506 unsigned long kernelcore_node
, kernelcore_remaining
;
5507 /* save the state before borrow the nodemask */
5508 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5509 unsigned long totalpages
= early_calculate_totalpages();
5510 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5511 struct memblock_region
*r
;
5513 /* Need to find movable_zone earlier when movable_node is specified. */
5514 find_usable_zone_for_movable();
5517 * If movable_node is specified, ignore kernelcore and movablecore
5520 if (movable_node_is_enabled()) {
5521 for_each_memblock(memory
, r
) {
5522 if (!memblock_is_hotpluggable(r
))
5527 usable_startpfn
= PFN_DOWN(r
->base
);
5528 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5529 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5537 * If movablecore=nn[KMG] was specified, calculate what size of
5538 * kernelcore that corresponds so that memory usable for
5539 * any allocation type is evenly spread. If both kernelcore
5540 * and movablecore are specified, then the value of kernelcore
5541 * will be used for required_kernelcore if it's greater than
5542 * what movablecore would have allowed.
5544 if (required_movablecore
) {
5545 unsigned long corepages
;
5548 * Round-up so that ZONE_MOVABLE is at least as large as what
5549 * was requested by the user
5551 required_movablecore
=
5552 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5553 required_movablecore
= min(totalpages
, required_movablecore
);
5554 corepages
= totalpages
- required_movablecore
;
5556 required_kernelcore
= max(required_kernelcore
, corepages
);
5560 * If kernelcore was not specified or kernelcore size is larger
5561 * than totalpages, there is no ZONE_MOVABLE.
5563 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5566 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5567 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5570 /* Spread kernelcore memory as evenly as possible throughout nodes */
5571 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5572 for_each_node_state(nid
, N_MEMORY
) {
5573 unsigned long start_pfn
, end_pfn
;
5576 * Recalculate kernelcore_node if the division per node
5577 * now exceeds what is necessary to satisfy the requested
5578 * amount of memory for the kernel
5580 if (required_kernelcore
< kernelcore_node
)
5581 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5584 * As the map is walked, we track how much memory is usable
5585 * by the kernel using kernelcore_remaining. When it is
5586 * 0, the rest of the node is usable by ZONE_MOVABLE
5588 kernelcore_remaining
= kernelcore_node
;
5590 /* Go through each range of PFNs within this node */
5591 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5592 unsigned long size_pages
;
5594 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5595 if (start_pfn
>= end_pfn
)
5598 /* Account for what is only usable for kernelcore */
5599 if (start_pfn
< usable_startpfn
) {
5600 unsigned long kernel_pages
;
5601 kernel_pages
= min(end_pfn
, usable_startpfn
)
5604 kernelcore_remaining
-= min(kernel_pages
,
5605 kernelcore_remaining
);
5606 required_kernelcore
-= min(kernel_pages
,
5607 required_kernelcore
);
5609 /* Continue if range is now fully accounted */
5610 if (end_pfn
<= usable_startpfn
) {
5613 * Push zone_movable_pfn to the end so
5614 * that if we have to rebalance
5615 * kernelcore across nodes, we will
5616 * not double account here
5618 zone_movable_pfn
[nid
] = end_pfn
;
5621 start_pfn
= usable_startpfn
;
5625 * The usable PFN range for ZONE_MOVABLE is from
5626 * start_pfn->end_pfn. Calculate size_pages as the
5627 * number of pages used as kernelcore
5629 size_pages
= end_pfn
- start_pfn
;
5630 if (size_pages
> kernelcore_remaining
)
5631 size_pages
= kernelcore_remaining
;
5632 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5635 * Some kernelcore has been met, update counts and
5636 * break if the kernelcore for this node has been
5639 required_kernelcore
-= min(required_kernelcore
,
5641 kernelcore_remaining
-= size_pages
;
5642 if (!kernelcore_remaining
)
5648 * If there is still required_kernelcore, we do another pass with one
5649 * less node in the count. This will push zone_movable_pfn[nid] further
5650 * along on the nodes that still have memory until kernelcore is
5654 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5658 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5659 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5660 zone_movable_pfn
[nid
] =
5661 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5664 /* restore the node_state */
5665 node_states
[N_MEMORY
] = saved_node_state
;
5668 /* Any regular or high memory on that node ? */
5669 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5671 enum zone_type zone_type
;
5673 if (N_MEMORY
== N_NORMAL_MEMORY
)
5676 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5677 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5678 if (populated_zone(zone
)) {
5679 node_set_state(nid
, N_HIGH_MEMORY
);
5680 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5681 zone_type
<= ZONE_NORMAL
)
5682 node_set_state(nid
, N_NORMAL_MEMORY
);
5689 * free_area_init_nodes - Initialise all pg_data_t and zone data
5690 * @max_zone_pfn: an array of max PFNs for each zone
5692 * This will call free_area_init_node() for each active node in the system.
5693 * Using the page ranges provided by memblock_set_node(), the size of each
5694 * zone in each node and their holes is calculated. If the maximum PFN
5695 * between two adjacent zones match, it is assumed that the zone is empty.
5696 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5697 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5698 * starts where the previous one ended. For example, ZONE_DMA32 starts
5699 * at arch_max_dma_pfn.
5701 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5703 unsigned long start_pfn
, end_pfn
;
5706 /* Record where the zone boundaries are */
5707 memset(arch_zone_lowest_possible_pfn
, 0,
5708 sizeof(arch_zone_lowest_possible_pfn
));
5709 memset(arch_zone_highest_possible_pfn
, 0,
5710 sizeof(arch_zone_highest_possible_pfn
));
5712 start_pfn
= find_min_pfn_with_active_regions();
5714 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5715 if (i
== ZONE_MOVABLE
)
5718 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
5719 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
5720 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
5722 start_pfn
= end_pfn
;
5724 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5725 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5727 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5728 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5729 find_zone_movable_pfns_for_nodes();
5731 /* Print out the zone ranges */
5732 pr_info("Zone ranges:\n");
5733 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5734 if (i
== ZONE_MOVABLE
)
5736 pr_info(" %-8s ", zone_names
[i
]);
5737 if (arch_zone_lowest_possible_pfn
[i
] ==
5738 arch_zone_highest_possible_pfn
[i
])
5741 pr_cont("[mem %#018Lx-%#018Lx]\n",
5742 (u64
)arch_zone_lowest_possible_pfn
[i
]
5744 ((u64
)arch_zone_highest_possible_pfn
[i
]
5745 << PAGE_SHIFT
) - 1);
5748 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5749 pr_info("Movable zone start for each node\n");
5750 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5751 if (zone_movable_pfn
[i
])
5752 pr_info(" Node %d: %#018Lx\n", i
,
5753 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5756 /* Print out the early node map */
5757 pr_info("Early memory node ranges\n");
5758 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5759 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5760 (u64
)start_pfn
<< PAGE_SHIFT
,
5761 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5763 /* Initialise every node */
5764 mminit_verify_pageflags_layout();
5765 setup_nr_node_ids();
5766 for_each_online_node(nid
) {
5767 pg_data_t
*pgdat
= NODE_DATA(nid
);
5768 free_area_init_node(nid
, NULL
,
5769 find_min_pfn_for_node(nid
), NULL
);
5771 /* Any memory on that node */
5772 if (pgdat
->node_present_pages
)
5773 node_set_state(nid
, N_MEMORY
);
5774 check_for_memory(pgdat
, nid
);
5778 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5780 unsigned long long coremem
;
5784 coremem
= memparse(p
, &p
);
5785 *core
= coremem
>> PAGE_SHIFT
;
5787 /* Paranoid check that UL is enough for the coremem value */
5788 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5794 * kernelcore=size sets the amount of memory for use for allocations that
5795 * cannot be reclaimed or migrated.
5797 static int __init
cmdline_parse_kernelcore(char *p
)
5799 return cmdline_parse_core(p
, &required_kernelcore
);
5803 * movablecore=size sets the amount of memory for use for allocations that
5804 * can be reclaimed or migrated.
5806 static int __init
cmdline_parse_movablecore(char *p
)
5808 return cmdline_parse_core(p
, &required_movablecore
);
5811 early_param("kernelcore", cmdline_parse_kernelcore
);
5812 early_param("movablecore", cmdline_parse_movablecore
);
5814 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5816 void adjust_managed_page_count(struct page
*page
, long count
)
5818 spin_lock(&managed_page_count_lock
);
5819 page_zone(page
)->managed_pages
+= count
;
5820 totalram_pages
+= count
;
5821 #ifdef CONFIG_HIGHMEM
5822 if (PageHighMem(page
))
5823 totalhigh_pages
+= count
;
5825 spin_unlock(&managed_page_count_lock
);
5827 EXPORT_SYMBOL(adjust_managed_page_count
);
5829 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5832 unsigned long pages
= 0;
5834 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5835 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5836 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5837 if ((unsigned int)poison
<= 0xFF)
5838 memset(pos
, poison
, PAGE_SIZE
);
5839 free_reserved_page(virt_to_page(pos
));
5843 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5844 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5848 EXPORT_SYMBOL(free_reserved_area
);
5850 #ifdef CONFIG_HIGHMEM
5851 void free_highmem_page(struct page
*page
)
5853 __free_reserved_page(page
);
5855 page_zone(page
)->managed_pages
++;
5861 void __init
mem_init_print_info(const char *str
)
5863 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5864 unsigned long init_code_size
, init_data_size
;
5866 physpages
= get_num_physpages();
5867 codesize
= _etext
- _stext
;
5868 datasize
= _edata
- _sdata
;
5869 rosize
= __end_rodata
- __start_rodata
;
5870 bss_size
= __bss_stop
- __bss_start
;
5871 init_data_size
= __init_end
- __init_begin
;
5872 init_code_size
= _einittext
- _sinittext
;
5875 * Detect special cases and adjust section sizes accordingly:
5876 * 1) .init.* may be embedded into .data sections
5877 * 2) .init.text.* may be out of [__init_begin, __init_end],
5878 * please refer to arch/tile/kernel/vmlinux.lds.S.
5879 * 3) .rodata.* may be embedded into .text or .data sections.
5881 #define adj_init_size(start, end, size, pos, adj) \
5883 if (start <= pos && pos < end && size > adj) \
5887 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5888 _sinittext
, init_code_size
);
5889 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5890 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5891 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5892 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5894 #undef adj_init_size
5896 pr_info("Memory: %luK/%luK available "
5897 "(%luK kernel code, %luK rwdata, %luK rodata, "
5898 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5899 #ifdef CONFIG_HIGHMEM
5903 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5904 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5905 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5906 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
5907 totalcma_pages
<< (PAGE_SHIFT
-10),
5908 #ifdef CONFIG_HIGHMEM
5909 totalhigh_pages
<< (PAGE_SHIFT
-10),
5911 str
? ", " : "", str
? str
: "");
5915 * set_dma_reserve - set the specified number of pages reserved in the first zone
5916 * @new_dma_reserve: The number of pages to mark reserved
5918 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
5919 * In the DMA zone, a significant percentage may be consumed by kernel image
5920 * and other unfreeable allocations which can skew the watermarks badly. This
5921 * function may optionally be used to account for unfreeable pages in the
5922 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5923 * smaller per-cpu batchsize.
5925 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5927 dma_reserve
= new_dma_reserve
;
5930 void __init
free_area_init(unsigned long *zones_size
)
5932 free_area_init_node(0, zones_size
,
5933 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5936 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5937 unsigned long action
, void *hcpu
)
5939 int cpu
= (unsigned long)hcpu
;
5941 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5942 lru_add_drain_cpu(cpu
);
5946 * Spill the event counters of the dead processor
5947 * into the current processors event counters.
5948 * This artificially elevates the count of the current
5951 vm_events_fold_cpu(cpu
);
5954 * Zero the differential counters of the dead processor
5955 * so that the vm statistics are consistent.
5957 * This is only okay since the processor is dead and cannot
5958 * race with what we are doing.
5960 cpu_vm_stats_fold(cpu
);
5965 void __init
page_alloc_init(void)
5967 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5971 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
5972 * or min_free_kbytes changes.
5974 static void calculate_totalreserve_pages(void)
5976 struct pglist_data
*pgdat
;
5977 unsigned long reserve_pages
= 0;
5978 enum zone_type i
, j
;
5980 for_each_online_pgdat(pgdat
) {
5981 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5982 struct zone
*zone
= pgdat
->node_zones
+ i
;
5985 /* Find valid and maximum lowmem_reserve in the zone */
5986 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5987 if (zone
->lowmem_reserve
[j
] > max
)
5988 max
= zone
->lowmem_reserve
[j
];
5991 /* we treat the high watermark as reserved pages. */
5992 max
+= high_wmark_pages(zone
);
5994 if (max
> zone
->managed_pages
)
5995 max
= zone
->managed_pages
;
5996 reserve_pages
+= max
;
5998 * Lowmem reserves are not available to
5999 * GFP_HIGHUSER page cache allocations and
6000 * kswapd tries to balance zones to their high
6001 * watermark. As a result, neither should be
6002 * regarded as dirtyable memory, to prevent a
6003 * situation where reclaim has to clean pages
6004 * in order to balance the zones.
6006 zone
->dirty_balance_reserve
= max
;
6009 dirty_balance_reserve
= reserve_pages
;
6010 totalreserve_pages
= reserve_pages
;
6014 * setup_per_zone_lowmem_reserve - called whenever
6015 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6016 * has a correct pages reserved value, so an adequate number of
6017 * pages are left in the zone after a successful __alloc_pages().
6019 static void setup_per_zone_lowmem_reserve(void)
6021 struct pglist_data
*pgdat
;
6022 enum zone_type j
, idx
;
6024 for_each_online_pgdat(pgdat
) {
6025 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6026 struct zone
*zone
= pgdat
->node_zones
+ j
;
6027 unsigned long managed_pages
= zone
->managed_pages
;
6029 zone
->lowmem_reserve
[j
] = 0;
6033 struct zone
*lower_zone
;
6037 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6038 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6040 lower_zone
= pgdat
->node_zones
+ idx
;
6041 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6042 sysctl_lowmem_reserve_ratio
[idx
];
6043 managed_pages
+= lower_zone
->managed_pages
;
6048 /* update totalreserve_pages */
6049 calculate_totalreserve_pages();
6052 static void __setup_per_zone_wmarks(void)
6054 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6055 unsigned long pages_low
= extra_free_kbytes
>> (PAGE_SHIFT
- 10);
6056 unsigned long lowmem_pages
= 0;
6058 unsigned long flags
;
6060 /* Calculate total number of !ZONE_HIGHMEM pages */
6061 for_each_zone(zone
) {
6062 if (!is_highmem(zone
))
6063 lowmem_pages
+= zone
->managed_pages
;
6066 for_each_zone(zone
) {
6069 spin_lock_irqsave(&zone
->lock
, flags
);
6070 min
= (u64
)pages_min
* zone
->managed_pages
;
6071 do_div(min
, lowmem_pages
);
6072 low
= (u64
)pages_low
* zone
->managed_pages
;
6073 do_div(low
, vm_total_pages
);
6075 if (is_highmem(zone
)) {
6077 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6078 * need highmem pages, so cap pages_min to a small
6081 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6082 * deltas control asynch page reclaim, and so should
6083 * not be capped for highmem.
6085 unsigned long min_pages
;
6087 min_pages
= zone
->managed_pages
/ 1024;
6088 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6089 zone
->watermark
[WMARK_MIN
] = min_pages
;
6092 * If it's a lowmem zone, reserve a number of pages
6093 * proportionate to the zone's size.
6095 zone
->watermark
[WMARK_MIN
] = min
;
6098 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) +
6100 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) +
6103 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6104 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6105 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6107 spin_unlock_irqrestore(&zone
->lock
, flags
);
6110 /* update totalreserve_pages */
6111 calculate_totalreserve_pages();
6115 * setup_per_zone_wmarks - called when min_free_kbytes changes
6116 * or when memory is hot-{added|removed}
6118 * Ensures that the watermark[min,low,high] values for each zone are set
6119 * correctly with respect to min_free_kbytes.
6121 void setup_per_zone_wmarks(void)
6123 mutex_lock(&zonelists_mutex
);
6124 __setup_per_zone_wmarks();
6125 mutex_unlock(&zonelists_mutex
);
6129 * The inactive anon list should be small enough that the VM never has to
6130 * do too much work, but large enough that each inactive page has a chance
6131 * to be referenced again before it is swapped out.
6133 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6134 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6135 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6136 * the anonymous pages are kept on the inactive list.
6139 * memory ratio inactive anon
6140 * -------------------------------------
6149 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6151 unsigned int gb
, ratio
;
6153 /* Zone size in gigabytes */
6154 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6156 ratio
= int_sqrt(10 * gb
);
6160 zone
->inactive_ratio
= ratio
;
6163 static void __meminit
setup_per_zone_inactive_ratio(void)
6168 calculate_zone_inactive_ratio(zone
);
6172 * Initialise min_free_kbytes.
6174 * For small machines we want it small (128k min). For large machines
6175 * we want it large (64MB max). But it is not linear, because network
6176 * bandwidth does not increase linearly with machine size. We use
6178 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6179 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6195 int __meminit
init_per_zone_wmark_min(void)
6197 unsigned long lowmem_kbytes
;
6198 int new_min_free_kbytes
;
6200 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6201 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6203 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6204 min_free_kbytes
= new_min_free_kbytes
;
6205 if (min_free_kbytes
< 128)
6206 min_free_kbytes
= 128;
6207 if (min_free_kbytes
> 65536)
6208 min_free_kbytes
= 65536;
6210 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6211 new_min_free_kbytes
, user_min_free_kbytes
);
6213 setup_per_zone_wmarks();
6214 refresh_zone_stat_thresholds();
6215 setup_per_zone_lowmem_reserve();
6216 setup_per_zone_inactive_ratio();
6219 core_initcall(init_per_zone_wmark_min
)
6222 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6223 * that we can call two helper functions whenever min_free_kbytes
6224 * or extra_free_kbytes changes.
6226 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6227 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6231 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6236 user_min_free_kbytes
= min_free_kbytes
;
6237 setup_per_zone_wmarks();
6243 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6244 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6249 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6254 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6255 sysctl_min_unmapped_ratio
) / 100;
6259 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6260 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6265 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6270 zone
->min_slab_pages
= (zone
->managed_pages
*
6271 sysctl_min_slab_ratio
) / 100;
6277 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6278 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6279 * whenever sysctl_lowmem_reserve_ratio changes.
6281 * The reserve ratio obviously has absolutely no relation with the
6282 * minimum watermarks. The lowmem reserve ratio can only make sense
6283 * if in function of the boot time zone sizes.
6285 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6286 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6288 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6289 setup_per_zone_lowmem_reserve();
6294 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6295 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6296 * pagelist can have before it gets flushed back to buddy allocator.
6298 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6299 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6302 int old_percpu_pagelist_fraction
;
6305 mutex_lock(&pcp_batch_high_lock
);
6306 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6308 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6309 if (!write
|| ret
< 0)
6312 /* Sanity checking to avoid pcp imbalance */
6313 if (percpu_pagelist_fraction
&&
6314 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6315 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6321 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6324 for_each_populated_zone(zone
) {
6327 for_each_possible_cpu(cpu
)
6328 pageset_set_high_and_batch(zone
,
6329 per_cpu_ptr(zone
->pageset
, cpu
));
6332 mutex_unlock(&pcp_batch_high_lock
);
6337 int hashdist
= HASHDIST_DEFAULT
;
6339 static int __init
set_hashdist(char *str
)
6343 hashdist
= simple_strtoul(str
, &str
, 0);
6346 __setup("hashdist=", set_hashdist
);
6350 * allocate a large system hash table from bootmem
6351 * - it is assumed that the hash table must contain an exact power-of-2
6352 * quantity of entries
6353 * - limit is the number of hash buckets, not the total allocation size
6355 void *__init
alloc_large_system_hash(const char *tablename
,
6356 unsigned long bucketsize
,
6357 unsigned long numentries
,
6360 unsigned int *_hash_shift
,
6361 unsigned int *_hash_mask
,
6362 unsigned long low_limit
,
6363 unsigned long high_limit
)
6365 unsigned long long max
= high_limit
;
6366 unsigned long log2qty
, size
;
6369 /* allow the kernel cmdline to have a say */
6371 /* round applicable memory size up to nearest megabyte */
6372 numentries
= nr_kernel_pages
;
6374 /* It isn't necessary when PAGE_SIZE >= 1MB */
6375 if (PAGE_SHIFT
< 20)
6376 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6378 /* limit to 1 bucket per 2^scale bytes of low memory */
6379 if (scale
> PAGE_SHIFT
)
6380 numentries
>>= (scale
- PAGE_SHIFT
);
6382 numentries
<<= (PAGE_SHIFT
- scale
);
6384 /* Make sure we've got at least a 0-order allocation.. */
6385 if (unlikely(flags
& HASH_SMALL
)) {
6386 /* Makes no sense without HASH_EARLY */
6387 WARN_ON(!(flags
& HASH_EARLY
));
6388 if (!(numentries
>> *_hash_shift
)) {
6389 numentries
= 1UL << *_hash_shift
;
6390 BUG_ON(!numentries
);
6392 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6393 numentries
= PAGE_SIZE
/ bucketsize
;
6395 numentries
= roundup_pow_of_two(numentries
);
6397 /* limit allocation size to 1/16 total memory by default */
6399 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6400 do_div(max
, bucketsize
);
6402 max
= min(max
, 0x80000000ULL
);
6404 if (numentries
< low_limit
)
6405 numentries
= low_limit
;
6406 if (numentries
> max
)
6409 log2qty
= ilog2(numentries
);
6412 size
= bucketsize
<< log2qty
;
6413 if (flags
& HASH_EARLY
)
6414 table
= memblock_virt_alloc_nopanic(size
, 0);
6416 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6419 * If bucketsize is not a power-of-two, we may free
6420 * some pages at the end of hash table which
6421 * alloc_pages_exact() automatically does
6423 if (get_order(size
) < MAX_ORDER
) {
6424 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6425 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6428 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6431 panic("Failed to allocate %s hash table\n", tablename
);
6433 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6436 ilog2(size
) - PAGE_SHIFT
,
6440 *_hash_shift
= log2qty
;
6442 *_hash_mask
= (1 << log2qty
) - 1;
6447 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6448 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6451 #ifdef CONFIG_SPARSEMEM
6452 return __pfn_to_section(pfn
)->pageblock_flags
;
6454 return zone
->pageblock_flags
;
6455 #endif /* CONFIG_SPARSEMEM */
6458 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6460 #ifdef CONFIG_SPARSEMEM
6461 pfn
&= (PAGES_PER_SECTION
-1);
6462 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6464 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6465 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6466 #endif /* CONFIG_SPARSEMEM */
6470 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6471 * @page: The page within the block of interest
6472 * @pfn: The target page frame number
6473 * @end_bitidx: The last bit of interest to retrieve
6474 * @mask: mask of bits that the caller is interested in
6476 * Return: pageblock_bits flags
6478 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6479 unsigned long end_bitidx
,
6483 unsigned long *bitmap
;
6484 unsigned long bitidx
, word_bitidx
;
6487 zone
= page_zone(page
);
6488 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6489 bitidx
= pfn_to_bitidx(zone
, pfn
);
6490 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6491 bitidx
&= (BITS_PER_LONG
-1);
6493 word
= bitmap
[word_bitidx
];
6494 bitidx
+= end_bitidx
;
6495 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6499 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6500 * @page: The page within the block of interest
6501 * @flags: The flags to set
6502 * @pfn: The target page frame number
6503 * @end_bitidx: The last bit of interest
6504 * @mask: mask of bits that the caller is interested in
6506 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6508 unsigned long end_bitidx
,
6512 unsigned long *bitmap
;
6513 unsigned long bitidx
, word_bitidx
;
6514 unsigned long old_word
, word
;
6516 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6518 zone
= page_zone(page
);
6519 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6520 bitidx
= pfn_to_bitidx(zone
, pfn
);
6521 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6522 bitidx
&= (BITS_PER_LONG
-1);
6524 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6526 bitidx
+= end_bitidx
;
6527 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6528 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6530 word
= READ_ONCE(bitmap
[word_bitidx
]);
6532 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6533 if (word
== old_word
)
6540 * This function checks whether pageblock includes unmovable pages or not.
6541 * If @count is not zero, it is okay to include less @count unmovable pages
6543 * PageLRU check without isolation or lru_lock could race so that
6544 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6545 * expect this function should be exact.
6547 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6548 bool skip_hwpoisoned_pages
)
6550 unsigned long pfn
, iter
, found
;
6554 * For avoiding noise data, lru_add_drain_all() should be called
6555 * If ZONE_MOVABLE, the zone never contains unmovable pages
6557 if (zone_idx(zone
) == ZONE_MOVABLE
)
6559 mt
= get_pageblock_migratetype(page
);
6560 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6563 pfn
= page_to_pfn(page
);
6564 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6565 unsigned long check
= pfn
+ iter
;
6567 if (!pfn_valid_within(check
))
6570 page
= pfn_to_page(check
);
6573 * Hugepages are not in LRU lists, but they're movable.
6574 * We need not scan over tail pages bacause we don't
6575 * handle each tail page individually in migration.
6577 if (PageHuge(page
)) {
6578 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6583 * We can't use page_count without pin a page
6584 * because another CPU can free compound page.
6585 * This check already skips compound tails of THP
6586 * because their page->_count is zero at all time.
6588 if (!atomic_read(&page
->_count
)) {
6589 if (PageBuddy(page
))
6590 iter
+= (1 << page_order(page
)) - 1;
6595 * The HWPoisoned page may be not in buddy system, and
6596 * page_count() is not 0.
6598 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6604 * If there are RECLAIMABLE pages, we need to check
6605 * it. But now, memory offline itself doesn't call
6606 * shrink_node_slabs() and it still to be fixed.
6609 * If the page is not RAM, page_count()should be 0.
6610 * we don't need more check. This is an _used_ not-movable page.
6612 * The problematic thing here is PG_reserved pages. PG_reserved
6613 * is set to both of a memory hole page and a _used_ kernel
6622 bool is_pageblock_removable_nolock(struct page
*page
)
6628 * We have to be careful here because we are iterating over memory
6629 * sections which are not zone aware so we might end up outside of
6630 * the zone but still within the section.
6631 * We have to take care about the node as well. If the node is offline
6632 * its NODE_DATA will be NULL - see page_zone.
6634 if (!node_online(page_to_nid(page
)))
6637 zone
= page_zone(page
);
6638 pfn
= page_to_pfn(page
);
6639 if (!zone_spans_pfn(zone
, pfn
))
6642 return !has_unmovable_pages(zone
, page
, 0, true);
6647 static unsigned long pfn_max_align_down(unsigned long pfn
)
6649 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6650 pageblock_nr_pages
) - 1);
6653 static unsigned long pfn_max_align_up(unsigned long pfn
)
6655 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6656 pageblock_nr_pages
));
6659 /* [start, end) must belong to a single zone. */
6660 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6661 unsigned long start
, unsigned long end
)
6663 /* This function is based on compact_zone() from compaction.c. */
6664 unsigned long nr_reclaimed
;
6665 unsigned long pfn
= start
;
6666 unsigned int tries
= 0;
6671 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6672 if (fatal_signal_pending(current
)) {
6677 if (list_empty(&cc
->migratepages
)) {
6678 cc
->nr_migratepages
= 0;
6679 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6685 } else if (++tries
== 5) {
6686 ret
= ret
< 0 ? ret
: -EBUSY
;
6690 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6692 cc
->nr_migratepages
-= nr_reclaimed
;
6694 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6695 NULL
, 0, cc
->mode
, MR_CMA
);
6698 putback_movable_pages(&cc
->migratepages
);
6705 * alloc_contig_range() -- tries to allocate given range of pages
6706 * @start: start PFN to allocate
6707 * @end: one-past-the-last PFN to allocate
6708 * @migratetype: migratetype of the underlaying pageblocks (either
6709 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6710 * in range must have the same migratetype and it must
6711 * be either of the two.
6713 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6714 * aligned, however it's the caller's responsibility to guarantee that
6715 * we are the only thread that changes migrate type of pageblocks the
6718 * The PFN range must belong to a single zone.
6720 * Returns zero on success or negative error code. On success all
6721 * pages which PFN is in [start, end) are allocated for the caller and
6722 * need to be freed with free_contig_range().
6724 int alloc_contig_range(unsigned long start
, unsigned long end
,
6725 unsigned migratetype
)
6727 unsigned long outer_start
, outer_end
;
6731 struct compact_control cc
= {
6732 .nr_migratepages
= 0,
6734 .zone
= page_zone(pfn_to_page(start
)),
6735 .mode
= MIGRATE_SYNC
,
6736 .ignore_skip_hint
= true,
6738 INIT_LIST_HEAD(&cc
.migratepages
);
6741 * What we do here is we mark all pageblocks in range as
6742 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6743 * have different sizes, and due to the way page allocator
6744 * work, we align the range to biggest of the two pages so
6745 * that page allocator won't try to merge buddies from
6746 * different pageblocks and change MIGRATE_ISOLATE to some
6747 * other migration type.
6749 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6750 * migrate the pages from an unaligned range (ie. pages that
6751 * we are interested in). This will put all the pages in
6752 * range back to page allocator as MIGRATE_ISOLATE.
6754 * When this is done, we take the pages in range from page
6755 * allocator removing them from the buddy system. This way
6756 * page allocator will never consider using them.
6758 * This lets us mark the pageblocks back as
6759 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6760 * aligned range but not in the unaligned, original range are
6761 * put back to page allocator so that buddy can use them.
6764 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6765 pfn_max_align_up(end
), migratetype
,
6770 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6775 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6776 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6777 * more, all pages in [start, end) are free in page allocator.
6778 * What we are going to do is to allocate all pages from
6779 * [start, end) (that is remove them from page allocator).
6781 * The only problem is that pages at the beginning and at the
6782 * end of interesting range may be not aligned with pages that
6783 * page allocator holds, ie. they can be part of higher order
6784 * pages. Because of this, we reserve the bigger range and
6785 * once this is done free the pages we are not interested in.
6787 * We don't have to hold zone->lock here because the pages are
6788 * isolated thus they won't get removed from buddy.
6791 lru_add_drain_all();
6792 drain_all_pages(cc
.zone
);
6795 outer_start
= start
;
6796 while (!PageBuddy(pfn_to_page(outer_start
))) {
6797 if (++order
>= MAX_ORDER
) {
6801 outer_start
&= ~0UL << order
;
6804 /* Make sure the range is really isolated. */
6805 if (test_pages_isolated(outer_start
, end
, false)) {
6806 pr_info("%s: [%lx, %lx) PFNs busy\n",
6807 __func__
, outer_start
, end
);
6812 /* Grab isolated pages from freelists. */
6813 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6819 /* Free head and tail (if any) */
6820 if (start
!= outer_start
)
6821 free_contig_range(outer_start
, start
- outer_start
);
6822 if (end
!= outer_end
)
6823 free_contig_range(end
, outer_end
- end
);
6826 undo_isolate_page_range(pfn_max_align_down(start
),
6827 pfn_max_align_up(end
), migratetype
);
6831 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6833 unsigned int count
= 0;
6835 for (; nr_pages
--; pfn
++) {
6836 struct page
*page
= pfn_to_page(pfn
);
6838 count
+= page_count(page
) != 1;
6841 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6845 #ifdef CONFIG_MEMORY_HOTPLUG
6847 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6848 * page high values need to be recalulated.
6850 void __meminit
zone_pcp_update(struct zone
*zone
)
6853 mutex_lock(&pcp_batch_high_lock
);
6854 for_each_possible_cpu(cpu
)
6855 pageset_set_high_and_batch(zone
,
6856 per_cpu_ptr(zone
->pageset
, cpu
));
6857 mutex_unlock(&pcp_batch_high_lock
);
6861 void zone_pcp_reset(struct zone
*zone
)
6863 unsigned long flags
;
6865 struct per_cpu_pageset
*pset
;
6867 /* avoid races with drain_pages() */
6868 local_irq_save(flags
);
6869 if (zone
->pageset
!= &boot_pageset
) {
6870 for_each_online_cpu(cpu
) {
6871 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6872 drain_zonestat(zone
, pset
);
6874 free_percpu(zone
->pageset
);
6875 zone
->pageset
= &boot_pageset
;
6877 local_irq_restore(flags
);
6880 #ifdef CONFIG_MEMORY_HOTREMOVE
6882 * All pages in the range must be isolated before calling this.
6885 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6889 unsigned int order
, i
;
6891 unsigned long flags
;
6892 /* find the first valid pfn */
6893 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6898 zone
= page_zone(pfn_to_page(pfn
));
6899 spin_lock_irqsave(&zone
->lock
, flags
);
6901 while (pfn
< end_pfn
) {
6902 if (!pfn_valid(pfn
)) {
6906 page
= pfn_to_page(pfn
);
6908 * The HWPoisoned page may be not in buddy system, and
6909 * page_count() is not 0.
6911 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6913 SetPageReserved(page
);
6917 BUG_ON(page_count(page
));
6918 BUG_ON(!PageBuddy(page
));
6919 order
= page_order(page
);
6920 #ifdef CONFIG_DEBUG_VM
6921 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6922 pfn
, 1 << order
, end_pfn
);
6924 list_del(&page
->lru
);
6925 rmv_page_order(page
);
6926 zone
->free_area
[order
].nr_free
--;
6927 for (i
= 0; i
< (1 << order
); i
++)
6928 SetPageReserved((page
+i
));
6929 pfn
+= (1 << order
);
6931 spin_unlock_irqrestore(&zone
->lock
, flags
);
6935 #ifdef CONFIG_MEMORY_FAILURE
6936 bool is_free_buddy_page(struct page
*page
)
6938 struct zone
*zone
= page_zone(page
);
6939 unsigned long pfn
= page_to_pfn(page
);
6940 unsigned long flags
;
6943 spin_lock_irqsave(&zone
->lock
, flags
);
6944 for (order
= 0; order
< MAX_ORDER
; order
++) {
6945 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6947 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6950 spin_unlock_irqrestore(&zone
->lock
, flags
);
6952 return order
< MAX_ORDER
;