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/memremap.h>
47 #include <linux/stop_machine.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <trace/events/oom.h>
59 #include <linux/prefetch.h>
60 #include <linux/mm_inline.h>
61 #include <linux/migrate.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66 #include <linux/memcontrol.h>
68 #include <asm/sections.h>
69 #include <asm/tlbflush.h>
70 #include <asm/div64.h>
73 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
74 static DEFINE_MUTEX(pcp_batch_high_lock
);
75 #define MIN_PERCPU_PAGELIST_FRACTION (8)
77 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
78 DEFINE_PER_CPU(int, numa_node
);
79 EXPORT_PER_CPU_SYMBOL(numa_node
);
82 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
84 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
85 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
86 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
87 * defined in <linux/topology.h>.
89 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
90 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
91 int _node_numa_mem_
[MAX_NUMNODES
];
94 /* work_structs for global per-cpu drains */
95 DEFINE_MUTEX(pcpu_drain_mutex
);
96 DEFINE_PER_CPU(struct work_struct
, pcpu_drain
);
98 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
99 volatile unsigned long latent_entropy __latent_entropy
;
100 EXPORT_SYMBOL(latent_entropy
);
104 * Array of node states.
106 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
107 [N_POSSIBLE
] = NODE_MASK_ALL
,
108 [N_ONLINE
] = { { [0] = 1UL } },
110 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
111 #ifdef CONFIG_HIGHMEM
112 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
114 #ifdef CONFIG_MOVABLE_NODE
115 [N_MEMORY
] = { { [0] = 1UL } },
117 [N_CPU
] = { { [0] = 1UL } },
120 EXPORT_SYMBOL(node_states
);
122 /* Protect totalram_pages and zone->managed_pages */
123 static DEFINE_SPINLOCK(managed_page_count_lock
);
125 unsigned long totalram_pages __read_mostly
;
126 unsigned long totalreserve_pages __read_mostly
;
127 unsigned long totalcma_pages __read_mostly
;
129 int percpu_pagelist_fraction
;
130 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
133 * A cached value of the page's pageblock's migratetype, used when the page is
134 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
135 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
136 * Also the migratetype set in the page does not necessarily match the pcplist
137 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
138 * other index - this ensures that it will be put on the correct CMA freelist.
140 static inline int get_pcppage_migratetype(struct page
*page
)
145 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
147 page
->index
= migratetype
;
150 #ifdef CONFIG_PM_SLEEP
152 * The following functions are used by the suspend/hibernate code to temporarily
153 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
154 * while devices are suspended. To avoid races with the suspend/hibernate code,
155 * they should always be called with pm_mutex held (gfp_allowed_mask also should
156 * only be modified with pm_mutex held, unless the suspend/hibernate code is
157 * guaranteed not to run in parallel with that modification).
160 static gfp_t saved_gfp_mask
;
162 void pm_restore_gfp_mask(void)
164 WARN_ON(!mutex_is_locked(&pm_mutex
));
165 if (saved_gfp_mask
) {
166 gfp_allowed_mask
= saved_gfp_mask
;
171 void pm_restrict_gfp_mask(void)
173 WARN_ON(!mutex_is_locked(&pm_mutex
));
174 WARN_ON(saved_gfp_mask
);
175 saved_gfp_mask
= gfp_allowed_mask
;
176 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
179 bool pm_suspended_storage(void)
181 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
185 #endif /* CONFIG_PM_SLEEP */
187 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
188 unsigned int pageblock_order __read_mostly
;
191 static void __free_pages_ok(struct page
*page
, unsigned int order
);
194 * results with 256, 32 in the lowmem_reserve sysctl:
195 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
196 * 1G machine -> (16M dma, 784M normal, 224M high)
197 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
198 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
199 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
201 * TBD: should special case ZONE_DMA32 machines here - in those we normally
202 * don't need any ZONE_NORMAL reservation
204 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
205 #ifdef CONFIG_ZONE_DMA
208 #ifdef CONFIG_ZONE_DMA32
211 #ifdef CONFIG_HIGHMEM
217 EXPORT_SYMBOL(totalram_pages
);
219 static char * const zone_names
[MAX_NR_ZONES
] = {
220 #ifdef CONFIG_ZONE_DMA
223 #ifdef CONFIG_ZONE_DMA32
227 #ifdef CONFIG_HIGHMEM
231 #ifdef CONFIG_ZONE_DEVICE
236 char * const migratetype_names
[MIGRATE_TYPES
] = {
244 #ifdef CONFIG_MEMORY_ISOLATION
249 compound_page_dtor
* const compound_page_dtors
[] = {
252 #ifdef CONFIG_HUGETLB_PAGE
255 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
260 int min_free_kbytes
= 1024;
261 int user_min_free_kbytes
= -1;
262 int watermark_scale_factor
= 10;
264 static unsigned long __meminitdata nr_kernel_pages
;
265 static unsigned long __meminitdata nr_all_pages
;
266 static unsigned long __meminitdata dma_reserve
;
268 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
269 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
270 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
271 static unsigned long __initdata required_kernelcore
;
272 static unsigned long __initdata required_movablecore
;
273 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
274 static bool mirrored_kernelcore
;
276 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
278 EXPORT_SYMBOL(movable_zone
);
279 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
282 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
283 int nr_online_nodes __read_mostly
= 1;
284 EXPORT_SYMBOL(nr_node_ids
);
285 EXPORT_SYMBOL(nr_online_nodes
);
288 int page_group_by_mobility_disabled __read_mostly
;
290 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
291 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
293 pgdat
->first_deferred_pfn
= ULONG_MAX
;
296 /* Returns true if the struct page for the pfn is uninitialised */
297 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
299 int nid
= early_pfn_to_nid(pfn
);
301 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
308 * Returns false when the remaining initialisation should be deferred until
309 * later in the boot cycle when it can be parallelised.
311 static inline bool update_defer_init(pg_data_t
*pgdat
,
312 unsigned long pfn
, unsigned long zone_end
,
313 unsigned long *nr_initialised
)
315 unsigned long max_initialise
;
317 /* Always populate low zones for address-contrained allocations */
318 if (zone_end
< pgdat_end_pfn(pgdat
))
321 * Initialise at least 2G of a node but also take into account that
322 * two large system hashes that can take up 1GB for 0.25TB/node.
324 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
325 (pgdat
->node_spanned_pages
>> 8));
328 if ((*nr_initialised
> max_initialise
) &&
329 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
330 pgdat
->first_deferred_pfn
= pfn
;
337 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
341 static inline bool early_page_uninitialised(unsigned long pfn
)
346 static inline bool update_defer_init(pg_data_t
*pgdat
,
347 unsigned long pfn
, unsigned long zone_end
,
348 unsigned long *nr_initialised
)
354 /* Return a pointer to the bitmap storing bits affecting a block of pages */
355 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
358 #ifdef CONFIG_SPARSEMEM
359 return __pfn_to_section(pfn
)->pageblock_flags
;
361 return page_zone(page
)->pageblock_flags
;
362 #endif /* CONFIG_SPARSEMEM */
365 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
367 #ifdef CONFIG_SPARSEMEM
368 pfn
&= (PAGES_PER_SECTION
-1);
369 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
371 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
372 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
373 #endif /* CONFIG_SPARSEMEM */
377 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
378 * @page: The page within the block of interest
379 * @pfn: The target page frame number
380 * @end_bitidx: The last bit of interest to retrieve
381 * @mask: mask of bits that the caller is interested in
383 * Return: pageblock_bits flags
385 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
387 unsigned long end_bitidx
,
390 unsigned long *bitmap
;
391 unsigned long bitidx
, word_bitidx
;
394 bitmap
= get_pageblock_bitmap(page
, pfn
);
395 bitidx
= pfn_to_bitidx(page
, pfn
);
396 word_bitidx
= bitidx
/ BITS_PER_LONG
;
397 bitidx
&= (BITS_PER_LONG
-1);
399 word
= bitmap
[word_bitidx
];
400 bitidx
+= end_bitidx
;
401 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
404 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
405 unsigned long end_bitidx
,
408 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
411 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
413 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
417 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
418 * @page: The page within the block of interest
419 * @flags: The flags to set
420 * @pfn: The target page frame number
421 * @end_bitidx: The last bit of interest
422 * @mask: mask of bits that the caller is interested in
424 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
426 unsigned long end_bitidx
,
429 unsigned long *bitmap
;
430 unsigned long bitidx
, word_bitidx
;
431 unsigned long old_word
, word
;
433 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
435 bitmap
= get_pageblock_bitmap(page
, pfn
);
436 bitidx
= pfn_to_bitidx(page
, pfn
);
437 word_bitidx
= bitidx
/ BITS_PER_LONG
;
438 bitidx
&= (BITS_PER_LONG
-1);
440 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
442 bitidx
+= end_bitidx
;
443 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
444 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
446 word
= READ_ONCE(bitmap
[word_bitidx
]);
448 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
449 if (word
== old_word
)
455 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
457 if (unlikely(page_group_by_mobility_disabled
&&
458 migratetype
< MIGRATE_PCPTYPES
))
459 migratetype
= MIGRATE_UNMOVABLE
;
461 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
462 PB_migrate
, PB_migrate_end
);
465 #ifdef CONFIG_DEBUG_VM
466 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
470 unsigned long pfn
= page_to_pfn(page
);
471 unsigned long sp
, start_pfn
;
474 seq
= zone_span_seqbegin(zone
);
475 start_pfn
= zone
->zone_start_pfn
;
476 sp
= zone
->spanned_pages
;
477 if (!zone_spans_pfn(zone
, pfn
))
479 } while (zone_span_seqretry(zone
, seq
));
482 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
483 pfn
, zone_to_nid(zone
), zone
->name
,
484 start_pfn
, start_pfn
+ sp
);
489 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
491 if (!pfn_valid_within(page_to_pfn(page
)))
493 if (zone
!= page_zone(page
))
499 * Temporary debugging check for pages not lying within a given zone.
501 static int bad_range(struct zone
*zone
, struct page
*page
)
503 if (page_outside_zone_boundaries(zone
, page
))
505 if (!page_is_consistent(zone
, page
))
511 static inline int bad_range(struct zone
*zone
, struct page
*page
)
517 static void bad_page(struct page
*page
, const char *reason
,
518 unsigned long bad_flags
)
520 static unsigned long resume
;
521 static unsigned long nr_shown
;
522 static unsigned long nr_unshown
;
525 * Allow a burst of 60 reports, then keep quiet for that minute;
526 * or allow a steady drip of one report per second.
528 if (nr_shown
== 60) {
529 if (time_before(jiffies
, resume
)) {
535 "BUG: Bad page state: %lu messages suppressed\n",
542 resume
= jiffies
+ 60 * HZ
;
544 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
545 current
->comm
, page_to_pfn(page
));
546 __dump_page(page
, reason
);
547 bad_flags
&= page
->flags
;
549 pr_alert("bad because of flags: %#lx(%pGp)\n",
550 bad_flags
, &bad_flags
);
551 dump_page_owner(page
);
556 /* Leave bad fields for debug, except PageBuddy could make trouble */
557 page_mapcount_reset(page
); /* remove PageBuddy */
558 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
562 * Higher-order pages are called "compound pages". They are structured thusly:
564 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
566 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
567 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
569 * The first tail page's ->compound_dtor holds the offset in array of compound
570 * page destructors. See compound_page_dtors.
572 * The first tail page's ->compound_order holds the order of allocation.
573 * This usage means that zero-order pages may not be compound.
576 void free_compound_page(struct page
*page
)
578 __free_pages_ok(page
, compound_order(page
));
581 void prep_compound_page(struct page
*page
, unsigned int order
)
584 int nr_pages
= 1 << order
;
586 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
587 set_compound_order(page
, order
);
589 for (i
= 1; i
< nr_pages
; i
++) {
590 struct page
*p
= page
+ i
;
591 set_page_count(p
, 0);
592 p
->mapping
= TAIL_MAPPING
;
593 set_compound_head(p
, page
);
595 atomic_set(compound_mapcount_ptr(page
), -1);
598 #ifdef CONFIG_DEBUG_PAGEALLOC
599 unsigned int _debug_guardpage_minorder
;
600 bool _debug_pagealloc_enabled __read_mostly
601 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
602 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
603 bool _debug_guardpage_enabled __read_mostly
;
605 static int __init
early_debug_pagealloc(char *buf
)
609 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
611 early_param("debug_pagealloc", early_debug_pagealloc
);
613 static bool need_debug_guardpage(void)
615 /* If we don't use debug_pagealloc, we don't need guard page */
616 if (!debug_pagealloc_enabled())
619 if (!debug_guardpage_minorder())
625 static void init_debug_guardpage(void)
627 if (!debug_pagealloc_enabled())
630 if (!debug_guardpage_minorder())
633 _debug_guardpage_enabled
= true;
636 struct page_ext_operations debug_guardpage_ops
= {
637 .need
= need_debug_guardpage
,
638 .init
= init_debug_guardpage
,
641 static int __init
debug_guardpage_minorder_setup(char *buf
)
645 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
646 pr_err("Bad debug_guardpage_minorder value\n");
649 _debug_guardpage_minorder
= res
;
650 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
653 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
655 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
656 unsigned int order
, int migratetype
)
658 struct page_ext
*page_ext
;
660 if (!debug_guardpage_enabled())
663 if (order
>= debug_guardpage_minorder())
666 page_ext
= lookup_page_ext(page
);
667 if (unlikely(!page_ext
))
670 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
672 INIT_LIST_HEAD(&page
->lru
);
673 set_page_private(page
, order
);
674 /* Guard pages are not available for any usage */
675 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
680 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
681 unsigned int order
, int migratetype
)
683 struct page_ext
*page_ext
;
685 if (!debug_guardpage_enabled())
688 page_ext
= lookup_page_ext(page
);
689 if (unlikely(!page_ext
))
692 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
694 set_page_private(page
, 0);
695 if (!is_migrate_isolate(migratetype
))
696 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
699 struct page_ext_operations debug_guardpage_ops
;
700 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
701 unsigned int order
, int migratetype
) { return false; }
702 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
703 unsigned int order
, int migratetype
) {}
706 static inline void set_page_order(struct page
*page
, unsigned int order
)
708 set_page_private(page
, order
);
709 __SetPageBuddy(page
);
712 static inline void rmv_page_order(struct page
*page
)
714 __ClearPageBuddy(page
);
715 set_page_private(page
, 0);
719 * This function checks whether a page is free && is the buddy
720 * we can do coalesce a page and its buddy if
721 * (a) the buddy is not in a hole (check before calling!) &&
722 * (b) the buddy is in the buddy system &&
723 * (c) a page and its buddy have the same order &&
724 * (d) a page and its buddy are in the same zone.
726 * For recording whether a page is in the buddy system, we set ->_mapcount
727 * PAGE_BUDDY_MAPCOUNT_VALUE.
728 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
729 * serialized by zone->lock.
731 * For recording page's order, we use page_private(page).
733 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
736 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
737 if (page_zone_id(page
) != page_zone_id(buddy
))
740 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
745 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
747 * zone check is done late to avoid uselessly
748 * calculating zone/node ids for pages that could
751 if (page_zone_id(page
) != page_zone_id(buddy
))
754 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
762 * Freeing function for a buddy system allocator.
764 * The concept of a buddy system is to maintain direct-mapped table
765 * (containing bit values) for memory blocks of various "orders".
766 * The bottom level table contains the map for the smallest allocatable
767 * units of memory (here, pages), and each level above it describes
768 * pairs of units from the levels below, hence, "buddies".
769 * At a high level, all that happens here is marking the table entry
770 * at the bottom level available, and propagating the changes upward
771 * as necessary, plus some accounting needed to play nicely with other
772 * parts of the VM system.
773 * At each level, we keep a list of pages, which are heads of continuous
774 * free pages of length of (1 << order) and marked with _mapcount
775 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
777 * So when we are allocating or freeing one, we can derive the state of the
778 * other. That is, if we allocate a small block, and both were
779 * free, the remainder of the region must be split into blocks.
780 * If a block is freed, and its buddy is also free, then this
781 * triggers coalescing into a block of larger size.
786 static inline void __free_one_page(struct page
*page
,
788 struct zone
*zone
, unsigned int order
,
791 unsigned long combined_pfn
;
792 unsigned long uninitialized_var(buddy_pfn
);
794 unsigned int max_order
;
796 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
798 VM_BUG_ON(!zone_is_initialized(zone
));
799 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
801 VM_BUG_ON(migratetype
== -1);
802 if (likely(!is_migrate_isolate(migratetype
)))
803 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
805 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
806 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
809 while (order
< max_order
- 1) {
810 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
811 buddy
= page
+ (buddy_pfn
- pfn
);
813 if (!pfn_valid_within(buddy_pfn
))
815 if (!page_is_buddy(page
, buddy
, order
))
818 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
819 * merge with it and move up one order.
821 if (page_is_guard(buddy
)) {
822 clear_page_guard(zone
, buddy
, order
, migratetype
);
824 list_del(&buddy
->lru
);
825 zone
->free_area
[order
].nr_free
--;
826 rmv_page_order(buddy
);
828 combined_pfn
= buddy_pfn
& pfn
;
829 page
= page
+ (combined_pfn
- pfn
);
833 if (max_order
< MAX_ORDER
) {
834 /* If we are here, it means order is >= pageblock_order.
835 * We want to prevent merge between freepages on isolate
836 * pageblock and normal pageblock. Without this, pageblock
837 * isolation could cause incorrect freepage or CMA accounting.
839 * We don't want to hit this code for the more frequent
842 if (unlikely(has_isolate_pageblock(zone
))) {
845 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
846 buddy
= page
+ (buddy_pfn
- pfn
);
847 buddy_mt
= get_pageblock_migratetype(buddy
);
849 if (migratetype
!= buddy_mt
850 && (is_migrate_isolate(migratetype
) ||
851 is_migrate_isolate(buddy_mt
)))
855 goto continue_merging
;
859 set_page_order(page
, order
);
862 * If this is not the largest possible page, check if the buddy
863 * of the next-highest order is free. If it is, it's possible
864 * that pages are being freed that will coalesce soon. In case,
865 * that is happening, add the free page to the tail of the list
866 * so it's less likely to be used soon and more likely to be merged
867 * as a higher order page
869 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)) {
870 struct page
*higher_page
, *higher_buddy
;
871 combined_pfn
= buddy_pfn
& pfn
;
872 higher_page
= page
+ (combined_pfn
- pfn
);
873 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
874 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
875 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
876 list_add_tail(&page
->lru
,
877 &zone
->free_area
[order
].free_list
[migratetype
]);
882 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
884 zone
->free_area
[order
].nr_free
++;
888 * A bad page could be due to a number of fields. Instead of multiple branches,
889 * try and check multiple fields with one check. The caller must do a detailed
890 * check if necessary.
892 static inline bool page_expected_state(struct page
*page
,
893 unsigned long check_flags
)
895 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
898 if (unlikely((unsigned long)page
->mapping
|
899 page_ref_count(page
) |
901 (unsigned long)page
->mem_cgroup
|
903 (page
->flags
& check_flags
)))
909 static void free_pages_check_bad(struct page
*page
)
911 const char *bad_reason
;
912 unsigned long bad_flags
;
917 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
918 bad_reason
= "nonzero mapcount";
919 if (unlikely(page
->mapping
!= NULL
))
920 bad_reason
= "non-NULL mapping";
921 if (unlikely(page_ref_count(page
) != 0))
922 bad_reason
= "nonzero _refcount";
923 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
924 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
925 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
928 if (unlikely(page
->mem_cgroup
))
929 bad_reason
= "page still charged to cgroup";
931 bad_page(page
, bad_reason
, bad_flags
);
934 static inline int free_pages_check(struct page
*page
)
936 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
939 /* Something has gone sideways, find it */
940 free_pages_check_bad(page
);
944 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
949 * We rely page->lru.next never has bit 0 set, unless the page
950 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
952 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
954 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
958 switch (page
- head_page
) {
960 /* the first tail page: ->mapping is compound_mapcount() */
961 if (unlikely(compound_mapcount(page
))) {
962 bad_page(page
, "nonzero compound_mapcount", 0);
968 * the second tail page: ->mapping is
969 * page_deferred_list().next -- ignore value.
973 if (page
->mapping
!= TAIL_MAPPING
) {
974 bad_page(page
, "corrupted mapping in tail page", 0);
979 if (unlikely(!PageTail(page
))) {
980 bad_page(page
, "PageTail not set", 0);
983 if (unlikely(compound_head(page
) != head_page
)) {
984 bad_page(page
, "compound_head not consistent", 0);
989 page
->mapping
= NULL
;
990 clear_compound_head(page
);
994 static __always_inline
bool free_pages_prepare(struct page
*page
,
995 unsigned int order
, bool check_free
)
999 VM_BUG_ON_PAGE(PageTail(page
), page
);
1001 trace_mm_page_free(page
, order
);
1002 kmemcheck_free_shadow(page
, order
);
1005 * Check tail pages before head page information is cleared to
1006 * avoid checking PageCompound for order-0 pages.
1008 if (unlikely(order
)) {
1009 bool compound
= PageCompound(page
);
1012 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1015 ClearPageDoubleMap(page
);
1016 for (i
= 1; i
< (1 << order
); i
++) {
1018 bad
+= free_tail_pages_check(page
, page
+ i
);
1019 if (unlikely(free_pages_check(page
+ i
))) {
1023 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1026 if (PageMappingFlags(page
))
1027 page
->mapping
= NULL
;
1028 if (memcg_kmem_enabled() && PageKmemcg(page
))
1029 memcg_kmem_uncharge(page
, order
);
1031 bad
+= free_pages_check(page
);
1035 page_cpupid_reset_last(page
);
1036 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1037 reset_page_owner(page
, order
);
1039 if (!PageHighMem(page
)) {
1040 debug_check_no_locks_freed(page_address(page
),
1041 PAGE_SIZE
<< order
);
1042 debug_check_no_obj_freed(page_address(page
),
1043 PAGE_SIZE
<< order
);
1045 arch_free_page(page
, order
);
1046 kernel_poison_pages(page
, 1 << order
, 0);
1047 kernel_map_pages(page
, 1 << order
, 0);
1048 kasan_free_pages(page
, order
);
1053 #ifdef CONFIG_DEBUG_VM
1054 static inline bool free_pcp_prepare(struct page
*page
)
1056 return free_pages_prepare(page
, 0, true);
1059 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1064 static bool free_pcp_prepare(struct page
*page
)
1066 return free_pages_prepare(page
, 0, false);
1069 static bool bulkfree_pcp_prepare(struct page
*page
)
1071 return free_pages_check(page
);
1073 #endif /* CONFIG_DEBUG_VM */
1076 * Frees a number of pages from the PCP lists
1077 * Assumes all pages on list are in same zone, and of same order.
1078 * count is the number of pages to free.
1080 * If the zone was previously in an "all pages pinned" state then look to
1081 * see if this freeing clears that state.
1083 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1084 * pinned" detection logic.
1086 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1087 struct per_cpu_pages
*pcp
)
1089 int migratetype
= 0;
1091 unsigned long nr_scanned
, flags
;
1092 bool isolated_pageblocks
;
1094 spin_lock_irqsave(&zone
->lock
, flags
);
1095 isolated_pageblocks
= has_isolate_pageblock(zone
);
1096 nr_scanned
= node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
);
1098 __mod_node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
, -nr_scanned
);
1102 struct list_head
*list
;
1105 * Remove pages from lists in a round-robin fashion. A
1106 * batch_free count is maintained that is incremented when an
1107 * empty list is encountered. This is so more pages are freed
1108 * off fuller lists instead of spinning excessively around empty
1113 if (++migratetype
== MIGRATE_PCPTYPES
)
1115 list
= &pcp
->lists
[migratetype
];
1116 } while (list_empty(list
));
1118 /* This is the only non-empty list. Free them all. */
1119 if (batch_free
== MIGRATE_PCPTYPES
)
1123 int mt
; /* migratetype of the to-be-freed page */
1125 page
= list_last_entry(list
, struct page
, lru
);
1126 /* must delete as __free_one_page list manipulates */
1127 list_del(&page
->lru
);
1129 mt
= get_pcppage_migratetype(page
);
1130 /* MIGRATE_ISOLATE page should not go to pcplists */
1131 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1132 /* Pageblock could have been isolated meanwhile */
1133 if (unlikely(isolated_pageblocks
))
1134 mt
= get_pageblock_migratetype(page
);
1136 if (bulkfree_pcp_prepare(page
))
1139 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1140 trace_mm_page_pcpu_drain(page
, 0, mt
);
1141 } while (--count
&& --batch_free
&& !list_empty(list
));
1143 spin_unlock_irqrestore(&zone
->lock
, flags
);
1146 static void free_one_page(struct zone
*zone
,
1147 struct page
*page
, unsigned long pfn
,
1151 unsigned long nr_scanned
, flags
;
1152 spin_lock_irqsave(&zone
->lock
, flags
);
1153 __count_vm_events(PGFREE
, 1 << order
);
1154 nr_scanned
= node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
);
1156 __mod_node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
, -nr_scanned
);
1158 if (unlikely(has_isolate_pageblock(zone
) ||
1159 is_migrate_isolate(migratetype
))) {
1160 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1162 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1163 spin_unlock_irqrestore(&zone
->lock
, flags
);
1166 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1167 unsigned long zone
, int nid
)
1169 set_page_links(page
, zone
, nid
, pfn
);
1170 init_page_count(page
);
1171 page_mapcount_reset(page
);
1172 page_cpupid_reset_last(page
);
1174 INIT_LIST_HEAD(&page
->lru
);
1175 #ifdef WANT_PAGE_VIRTUAL
1176 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1177 if (!is_highmem_idx(zone
))
1178 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1182 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1185 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1188 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1189 static void init_reserved_page(unsigned long pfn
)
1194 if (!early_page_uninitialised(pfn
))
1197 nid
= early_pfn_to_nid(pfn
);
1198 pgdat
= NODE_DATA(nid
);
1200 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1201 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1203 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1206 __init_single_pfn(pfn
, zid
, nid
);
1209 static inline void init_reserved_page(unsigned long pfn
)
1212 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1215 * Initialised pages do not have PageReserved set. This function is
1216 * called for each range allocated by the bootmem allocator and
1217 * marks the pages PageReserved. The remaining valid pages are later
1218 * sent to the buddy page allocator.
1220 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1222 unsigned long start_pfn
= PFN_DOWN(start
);
1223 unsigned long end_pfn
= PFN_UP(end
);
1225 for (; start_pfn
< end_pfn
; start_pfn
++) {
1226 if (pfn_valid(start_pfn
)) {
1227 struct page
*page
= pfn_to_page(start_pfn
);
1229 init_reserved_page(start_pfn
);
1231 /* Avoid false-positive PageTail() */
1232 INIT_LIST_HEAD(&page
->lru
);
1234 SetPageReserved(page
);
1239 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1242 unsigned long pfn
= page_to_pfn(page
);
1244 if (!free_pages_prepare(page
, order
, true))
1247 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1248 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1251 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1253 unsigned int nr_pages
= 1 << order
;
1254 struct page
*p
= page
;
1258 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1260 __ClearPageReserved(p
);
1261 set_page_count(p
, 0);
1263 __ClearPageReserved(p
);
1264 set_page_count(p
, 0);
1266 page_zone(page
)->managed_pages
+= nr_pages
;
1267 set_page_refcounted(page
);
1268 __free_pages(page
, order
);
1271 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1272 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1274 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1276 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1278 static DEFINE_SPINLOCK(early_pfn_lock
);
1281 spin_lock(&early_pfn_lock
);
1282 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1284 nid
= first_online_node
;
1285 spin_unlock(&early_pfn_lock
);
1291 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1292 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1293 struct mminit_pfnnid_cache
*state
)
1297 nid
= __early_pfn_to_nid(pfn
, state
);
1298 if (nid
>= 0 && nid
!= node
)
1303 /* Only safe to use early in boot when initialisation is single-threaded */
1304 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1306 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1311 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1315 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1316 struct mminit_pfnnid_cache
*state
)
1323 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1326 if (early_page_uninitialised(pfn
))
1328 return __free_pages_boot_core(page
, order
);
1332 * Check that the whole (or subset of) a pageblock given by the interval of
1333 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1334 * with the migration of free compaction scanner. The scanners then need to
1335 * use only pfn_valid_within() check for arches that allow holes within
1338 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1340 * It's possible on some configurations to have a setup like node0 node1 node0
1341 * i.e. it's possible that all pages within a zones range of pages do not
1342 * belong to a single zone. We assume that a border between node0 and node1
1343 * can occur within a single pageblock, but not a node0 node1 node0
1344 * interleaving within a single pageblock. It is therefore sufficient to check
1345 * the first and last page of a pageblock and avoid checking each individual
1346 * page in a pageblock.
1348 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1349 unsigned long end_pfn
, struct zone
*zone
)
1351 struct page
*start_page
;
1352 struct page
*end_page
;
1354 /* end_pfn is one past the range we are checking */
1357 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1360 start_page
= pfn_to_page(start_pfn
);
1362 if (page_zone(start_page
) != zone
)
1365 end_page
= pfn_to_page(end_pfn
);
1367 /* This gives a shorter code than deriving page_zone(end_page) */
1368 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1374 void set_zone_contiguous(struct zone
*zone
)
1376 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1377 unsigned long block_end_pfn
;
1379 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1380 for (; block_start_pfn
< zone_end_pfn(zone
);
1381 block_start_pfn
= block_end_pfn
,
1382 block_end_pfn
+= pageblock_nr_pages
) {
1384 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1386 if (!__pageblock_pfn_to_page(block_start_pfn
,
1387 block_end_pfn
, zone
))
1391 /* We confirm that there is no hole */
1392 zone
->contiguous
= true;
1395 void clear_zone_contiguous(struct zone
*zone
)
1397 zone
->contiguous
= false;
1400 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1401 static void __init
deferred_free_range(struct page
*page
,
1402 unsigned long pfn
, int nr_pages
)
1409 /* Free a large naturally-aligned chunk if possible */
1410 if (nr_pages
== pageblock_nr_pages
&&
1411 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1412 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1413 __free_pages_boot_core(page
, pageblock_order
);
1417 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1418 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1419 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1420 __free_pages_boot_core(page
, 0);
1424 /* Completion tracking for deferred_init_memmap() threads */
1425 static atomic_t pgdat_init_n_undone __initdata
;
1426 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1428 static inline void __init
pgdat_init_report_one_done(void)
1430 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1431 complete(&pgdat_init_all_done_comp
);
1434 /* Initialise remaining memory on a node */
1435 static int __init
deferred_init_memmap(void *data
)
1437 pg_data_t
*pgdat
= data
;
1438 int nid
= pgdat
->node_id
;
1439 struct mminit_pfnnid_cache nid_init_state
= { };
1440 unsigned long start
= jiffies
;
1441 unsigned long nr_pages
= 0;
1442 unsigned long walk_start
, walk_end
;
1445 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1446 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1448 if (first_init_pfn
== ULONG_MAX
) {
1449 pgdat_init_report_one_done();
1453 /* Bind memory initialisation thread to a local node if possible */
1454 if (!cpumask_empty(cpumask
))
1455 set_cpus_allowed_ptr(current
, cpumask
);
1457 /* Sanity check boundaries */
1458 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1459 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1460 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1462 /* Only the highest zone is deferred so find it */
1463 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1464 zone
= pgdat
->node_zones
+ zid
;
1465 if (first_init_pfn
< zone_end_pfn(zone
))
1469 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1470 unsigned long pfn
, end_pfn
;
1471 struct page
*page
= NULL
;
1472 struct page
*free_base_page
= NULL
;
1473 unsigned long free_base_pfn
= 0;
1476 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1477 pfn
= first_init_pfn
;
1478 if (pfn
< walk_start
)
1480 if (pfn
< zone
->zone_start_pfn
)
1481 pfn
= zone
->zone_start_pfn
;
1483 for (; pfn
< end_pfn
; pfn
++) {
1484 if (!pfn_valid_within(pfn
))
1488 * Ensure pfn_valid is checked every
1489 * pageblock_nr_pages for memory holes
1491 if ((pfn
& (pageblock_nr_pages
- 1)) == 0) {
1492 if (!pfn_valid(pfn
)) {
1498 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1503 /* Minimise pfn page lookups and scheduler checks */
1504 if (page
&& (pfn
& (pageblock_nr_pages
- 1)) != 0) {
1507 nr_pages
+= nr_to_free
;
1508 deferred_free_range(free_base_page
,
1509 free_base_pfn
, nr_to_free
);
1510 free_base_page
= NULL
;
1511 free_base_pfn
= nr_to_free
= 0;
1513 page
= pfn_to_page(pfn
);
1518 VM_BUG_ON(page_zone(page
) != zone
);
1522 __init_single_page(page
, pfn
, zid
, nid
);
1523 if (!free_base_page
) {
1524 free_base_page
= page
;
1525 free_base_pfn
= pfn
;
1530 /* Where possible, batch up pages for a single free */
1533 /* Free the current block of pages to allocator */
1534 nr_pages
+= nr_to_free
;
1535 deferred_free_range(free_base_page
, free_base_pfn
,
1537 free_base_page
= NULL
;
1538 free_base_pfn
= nr_to_free
= 0;
1540 /* Free the last block of pages to allocator */
1541 nr_pages
+= nr_to_free
;
1542 deferred_free_range(free_base_page
, free_base_pfn
, nr_to_free
);
1544 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1547 /* Sanity check that the next zone really is unpopulated */
1548 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1550 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1551 jiffies_to_msecs(jiffies
- start
));
1553 pgdat_init_report_one_done();
1556 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1558 void __init
page_alloc_init_late(void)
1562 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1565 /* There will be num_node_state(N_MEMORY) threads */
1566 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1567 for_each_node_state(nid
, N_MEMORY
) {
1568 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1571 /* Block until all are initialised */
1572 wait_for_completion(&pgdat_init_all_done_comp
);
1574 /* Reinit limits that are based on free pages after the kernel is up */
1575 files_maxfiles_init();
1578 for_each_populated_zone(zone
)
1579 set_zone_contiguous(zone
);
1583 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1584 void __init
init_cma_reserved_pageblock(struct page
*page
)
1586 unsigned i
= pageblock_nr_pages
;
1587 struct page
*p
= page
;
1590 __ClearPageReserved(p
);
1591 set_page_count(p
, 0);
1594 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1596 if (pageblock_order
>= MAX_ORDER
) {
1597 i
= pageblock_nr_pages
;
1600 set_page_refcounted(p
);
1601 __free_pages(p
, MAX_ORDER
- 1);
1602 p
+= MAX_ORDER_NR_PAGES
;
1603 } while (i
-= MAX_ORDER_NR_PAGES
);
1605 set_page_refcounted(page
);
1606 __free_pages(page
, pageblock_order
);
1609 adjust_managed_page_count(page
, pageblock_nr_pages
);
1614 * The order of subdivision here is critical for the IO subsystem.
1615 * Please do not alter this order without good reasons and regression
1616 * testing. Specifically, as large blocks of memory are subdivided,
1617 * the order in which smaller blocks are delivered depends on the order
1618 * they're subdivided in this function. This is the primary factor
1619 * influencing the order in which pages are delivered to the IO
1620 * subsystem according to empirical testing, and this is also justified
1621 * by considering the behavior of a buddy system containing a single
1622 * large block of memory acted on by a series of small allocations.
1623 * This behavior is a critical factor in sglist merging's success.
1627 static inline void expand(struct zone
*zone
, struct page
*page
,
1628 int low
, int high
, struct free_area
*area
,
1631 unsigned long size
= 1 << high
;
1633 while (high
> low
) {
1637 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1640 * Mark as guard pages (or page), that will allow to
1641 * merge back to allocator when buddy will be freed.
1642 * Corresponding page table entries will not be touched,
1643 * pages will stay not present in virtual address space
1645 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1648 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1650 set_page_order(&page
[size
], high
);
1654 static void check_new_page_bad(struct page
*page
)
1656 const char *bad_reason
= NULL
;
1657 unsigned long bad_flags
= 0;
1659 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1660 bad_reason
= "nonzero mapcount";
1661 if (unlikely(page
->mapping
!= NULL
))
1662 bad_reason
= "non-NULL mapping";
1663 if (unlikely(page_ref_count(page
) != 0))
1664 bad_reason
= "nonzero _count";
1665 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1666 bad_reason
= "HWPoisoned (hardware-corrupted)";
1667 bad_flags
= __PG_HWPOISON
;
1668 /* Don't complain about hwpoisoned pages */
1669 page_mapcount_reset(page
); /* remove PageBuddy */
1672 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1673 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1674 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1677 if (unlikely(page
->mem_cgroup
))
1678 bad_reason
= "page still charged to cgroup";
1680 bad_page(page
, bad_reason
, bad_flags
);
1684 * This page is about to be returned from the page allocator
1686 static inline int check_new_page(struct page
*page
)
1688 if (likely(page_expected_state(page
,
1689 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1692 check_new_page_bad(page
);
1696 static inline bool free_pages_prezeroed(bool poisoned
)
1698 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1699 page_poisoning_enabled() && poisoned
;
1702 #ifdef CONFIG_DEBUG_VM
1703 static bool check_pcp_refill(struct page
*page
)
1708 static bool check_new_pcp(struct page
*page
)
1710 return check_new_page(page
);
1713 static bool check_pcp_refill(struct page
*page
)
1715 return check_new_page(page
);
1717 static bool check_new_pcp(struct page
*page
)
1721 #endif /* CONFIG_DEBUG_VM */
1723 static bool check_new_pages(struct page
*page
, unsigned int order
)
1726 for (i
= 0; i
< (1 << order
); i
++) {
1727 struct page
*p
= page
+ i
;
1729 if (unlikely(check_new_page(p
)))
1736 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1739 set_page_private(page
, 0);
1740 set_page_refcounted(page
);
1742 arch_alloc_page(page
, order
);
1743 kernel_map_pages(page
, 1 << order
, 1);
1744 kernel_poison_pages(page
, 1 << order
, 1);
1745 kasan_alloc_pages(page
, order
);
1746 set_page_owner(page
, order
, gfp_flags
);
1749 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1750 unsigned int alloc_flags
)
1753 bool poisoned
= true;
1755 for (i
= 0; i
< (1 << order
); i
++) {
1756 struct page
*p
= page
+ i
;
1758 poisoned
&= page_is_poisoned(p
);
1761 post_alloc_hook(page
, order
, gfp_flags
);
1763 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1764 for (i
= 0; i
< (1 << order
); i
++)
1765 clear_highpage(page
+ i
);
1767 if (order
&& (gfp_flags
& __GFP_COMP
))
1768 prep_compound_page(page
, order
);
1771 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1772 * allocate the page. The expectation is that the caller is taking
1773 * steps that will free more memory. The caller should avoid the page
1774 * being used for !PFMEMALLOC purposes.
1776 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1777 set_page_pfmemalloc(page
);
1779 clear_page_pfmemalloc(page
);
1783 * Go through the free lists for the given migratetype and remove
1784 * the smallest available page from the freelists
1787 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1790 unsigned int current_order
;
1791 struct free_area
*area
;
1794 /* Find a page of the appropriate size in the preferred list */
1795 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1796 area
= &(zone
->free_area
[current_order
]);
1797 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1801 list_del(&page
->lru
);
1802 rmv_page_order(page
);
1804 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1805 set_pcppage_migratetype(page
, migratetype
);
1814 * This array describes the order lists are fallen back to when
1815 * the free lists for the desirable migrate type are depleted
1817 static int fallbacks
[MIGRATE_TYPES
][4] = {
1818 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1819 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1820 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1822 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1824 #ifdef CONFIG_MEMORY_ISOLATION
1825 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1830 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1833 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1836 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1837 unsigned int order
) { return NULL
; }
1841 * Move the free pages in a range to the free lists of the requested type.
1842 * Note that start_page and end_pages are not aligned on a pageblock
1843 * boundary. If alignment is required, use move_freepages_block()
1845 int move_freepages(struct zone
*zone
,
1846 struct page
*start_page
, struct page
*end_page
,
1851 int pages_moved
= 0;
1853 #ifndef CONFIG_HOLES_IN_ZONE
1855 * page_zone is not safe to call in this context when
1856 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1857 * anyway as we check zone boundaries in move_freepages_block().
1858 * Remove at a later date when no bug reports exist related to
1859 * grouping pages by mobility
1861 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1864 for (page
= start_page
; page
<= end_page
;) {
1865 if (!pfn_valid_within(page_to_pfn(page
))) {
1870 /* Make sure we are not inadvertently changing nodes */
1871 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1873 if (!PageBuddy(page
)) {
1878 order
= page_order(page
);
1879 list_move(&page
->lru
,
1880 &zone
->free_area
[order
].free_list
[migratetype
]);
1882 pages_moved
+= 1 << order
;
1888 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1891 unsigned long start_pfn
, end_pfn
;
1892 struct page
*start_page
, *end_page
;
1894 start_pfn
= page_to_pfn(page
);
1895 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1896 start_page
= pfn_to_page(start_pfn
);
1897 end_page
= start_page
+ pageblock_nr_pages
- 1;
1898 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1900 /* Do not cross zone boundaries */
1901 if (!zone_spans_pfn(zone
, start_pfn
))
1903 if (!zone_spans_pfn(zone
, end_pfn
))
1906 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1909 static void change_pageblock_range(struct page
*pageblock_page
,
1910 int start_order
, int migratetype
)
1912 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1914 while (nr_pageblocks
--) {
1915 set_pageblock_migratetype(pageblock_page
, migratetype
);
1916 pageblock_page
+= pageblock_nr_pages
;
1921 * When we are falling back to another migratetype during allocation, try to
1922 * steal extra free pages from the same pageblocks to satisfy further
1923 * allocations, instead of polluting multiple pageblocks.
1925 * If we are stealing a relatively large buddy page, it is likely there will
1926 * be more free pages in the pageblock, so try to steal them all. For
1927 * reclaimable and unmovable allocations, we steal regardless of page size,
1928 * as fragmentation caused by those allocations polluting movable pageblocks
1929 * is worse than movable allocations stealing from unmovable and reclaimable
1932 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1935 * Leaving this order check is intended, although there is
1936 * relaxed order check in next check. The reason is that
1937 * we can actually steal whole pageblock if this condition met,
1938 * but, below check doesn't guarantee it and that is just heuristic
1939 * so could be changed anytime.
1941 if (order
>= pageblock_order
)
1944 if (order
>= pageblock_order
/ 2 ||
1945 start_mt
== MIGRATE_RECLAIMABLE
||
1946 start_mt
== MIGRATE_UNMOVABLE
||
1947 page_group_by_mobility_disabled
)
1954 * This function implements actual steal behaviour. If order is large enough,
1955 * we can steal whole pageblock. If not, we first move freepages in this
1956 * pageblock and check whether half of pages are moved or not. If half of
1957 * pages are moved, we can change migratetype of pageblock and permanently
1958 * use it's pages as requested migratetype in the future.
1960 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1963 unsigned int current_order
= page_order(page
);
1966 /* Take ownership for orders >= pageblock_order */
1967 if (current_order
>= pageblock_order
) {
1968 change_pageblock_range(page
, current_order
, start_type
);
1972 pages
= move_freepages_block(zone
, page
, start_type
);
1974 /* Claim the whole block if over half of it is free */
1975 if (pages
>= (1 << (pageblock_order
-1)) ||
1976 page_group_by_mobility_disabled
)
1977 set_pageblock_migratetype(page
, start_type
);
1981 * Check whether there is a suitable fallback freepage with requested order.
1982 * If only_stealable is true, this function returns fallback_mt only if
1983 * we can steal other freepages all together. This would help to reduce
1984 * fragmentation due to mixed migratetype pages in one pageblock.
1986 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1987 int migratetype
, bool only_stealable
, bool *can_steal
)
1992 if (area
->nr_free
== 0)
1997 fallback_mt
= fallbacks
[migratetype
][i
];
1998 if (fallback_mt
== MIGRATE_TYPES
)
2001 if (list_empty(&area
->free_list
[fallback_mt
]))
2004 if (can_steal_fallback(order
, migratetype
))
2007 if (!only_stealable
)
2018 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2019 * there are no empty page blocks that contain a page with a suitable order
2021 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2022 unsigned int alloc_order
)
2025 unsigned long max_managed
, flags
;
2028 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2029 * Check is race-prone but harmless.
2031 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2032 if (zone
->nr_reserved_highatomic
>= max_managed
)
2035 spin_lock_irqsave(&zone
->lock
, flags
);
2037 /* Recheck the nr_reserved_highatomic limit under the lock */
2038 if (zone
->nr_reserved_highatomic
>= max_managed
)
2042 mt
= get_pageblock_migratetype(page
);
2043 if (mt
!= MIGRATE_HIGHATOMIC
&&
2044 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
2045 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2046 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2047 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
2051 spin_unlock_irqrestore(&zone
->lock
, flags
);
2055 * Used when an allocation is about to fail under memory pressure. This
2056 * potentially hurts the reliability of high-order allocations when under
2057 * intense memory pressure but failed atomic allocations should be easier
2058 * to recover from than an OOM.
2060 * If @force is true, try to unreserve a pageblock even though highatomic
2061 * pageblock is exhausted.
2063 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2066 struct zonelist
*zonelist
= ac
->zonelist
;
2067 unsigned long flags
;
2074 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2077 * Preserve at least one pageblock unless memory pressure
2080 if (!force
&& zone
->nr_reserved_highatomic
<=
2084 spin_lock_irqsave(&zone
->lock
, flags
);
2085 for (order
= 0; order
< MAX_ORDER
; order
++) {
2086 struct free_area
*area
= &(zone
->free_area
[order
]);
2088 page
= list_first_entry_or_null(
2089 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2095 * In page freeing path, migratetype change is racy so
2096 * we can counter several free pages in a pageblock
2097 * in this loop althoug we changed the pageblock type
2098 * from highatomic to ac->migratetype. So we should
2099 * adjust the count once.
2101 if (get_pageblock_migratetype(page
) ==
2102 MIGRATE_HIGHATOMIC
) {
2104 * It should never happen but changes to
2105 * locking could inadvertently allow a per-cpu
2106 * drain to add pages to MIGRATE_HIGHATOMIC
2107 * while unreserving so be safe and watch for
2110 zone
->nr_reserved_highatomic
-= min(
2112 zone
->nr_reserved_highatomic
);
2116 * Convert to ac->migratetype and avoid the normal
2117 * pageblock stealing heuristics. Minimally, the caller
2118 * is doing the work and needs the pages. More
2119 * importantly, if the block was always converted to
2120 * MIGRATE_UNMOVABLE or another type then the number
2121 * of pageblocks that cannot be completely freed
2124 set_pageblock_migratetype(page
, ac
->migratetype
);
2125 ret
= move_freepages_block(zone
, page
, ac
->migratetype
);
2127 spin_unlock_irqrestore(&zone
->lock
, flags
);
2131 spin_unlock_irqrestore(&zone
->lock
, flags
);
2137 /* Remove an element from the buddy allocator from the fallback list */
2138 static inline struct page
*
2139 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
2141 struct free_area
*area
;
2142 unsigned int current_order
;
2147 /* Find the largest possible block of pages in the other list */
2148 for (current_order
= MAX_ORDER
-1;
2149 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
2151 area
= &(zone
->free_area
[current_order
]);
2152 fallback_mt
= find_suitable_fallback(area
, current_order
,
2153 start_migratetype
, false, &can_steal
);
2154 if (fallback_mt
== -1)
2157 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2160 get_pageblock_migratetype(page
) != MIGRATE_HIGHATOMIC
)
2161 steal_suitable_fallback(zone
, page
, start_migratetype
);
2163 /* Remove the page from the freelists */
2165 list_del(&page
->lru
);
2166 rmv_page_order(page
);
2168 expand(zone
, page
, order
, current_order
, area
,
2171 * The pcppage_migratetype may differ from pageblock's
2172 * migratetype depending on the decisions in
2173 * find_suitable_fallback(). This is OK as long as it does not
2174 * differ for MIGRATE_CMA pageblocks. Those can be used as
2175 * fallback only via special __rmqueue_cma_fallback() function
2177 set_pcppage_migratetype(page
, start_migratetype
);
2179 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2180 start_migratetype
, fallback_mt
);
2189 * Do the hard work of removing an element from the buddy allocator.
2190 * Call me with the zone->lock already held.
2192 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2197 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2198 if (unlikely(!page
)) {
2199 if (migratetype
== MIGRATE_MOVABLE
)
2200 page
= __rmqueue_cma_fallback(zone
, order
);
2203 page
= __rmqueue_fallback(zone
, order
, migratetype
);
2206 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2211 * Obtain a specified number of elements from the buddy allocator, all under
2212 * a single hold of the lock, for efficiency. Add them to the supplied list.
2213 * Returns the number of new pages which were placed at *list.
2215 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2216 unsigned long count
, struct list_head
*list
,
2217 int migratetype
, bool cold
)
2220 unsigned long flags
;
2222 spin_lock_irqsave(&zone
->lock
, flags
);
2223 for (i
= 0; i
< count
; ++i
) {
2224 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2225 if (unlikely(page
== NULL
))
2228 if (unlikely(check_pcp_refill(page
)))
2232 * Split buddy pages returned by expand() are received here
2233 * in physical page order. The page is added to the callers and
2234 * list and the list head then moves forward. From the callers
2235 * perspective, the linked list is ordered by page number in
2236 * some conditions. This is useful for IO devices that can
2237 * merge IO requests if the physical pages are ordered
2241 list_add(&page
->lru
, list
);
2243 list_add_tail(&page
->lru
, list
);
2246 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2247 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2252 * i pages were removed from the buddy list even if some leak due
2253 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2254 * on i. Do not confuse with 'alloced' which is the number of
2255 * pages added to the pcp list.
2257 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2258 spin_unlock_irqrestore(&zone
->lock
, flags
);
2264 * Called from the vmstat counter updater to drain pagesets of this
2265 * currently executing processor on remote nodes after they have
2268 * Note that this function must be called with the thread pinned to
2269 * a single processor.
2271 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2273 unsigned long flags
;
2274 int to_drain
, batch
;
2276 local_irq_save(flags
);
2277 batch
= READ_ONCE(pcp
->batch
);
2278 to_drain
= min(pcp
->count
, batch
);
2280 free_pcppages_bulk(zone
, to_drain
, pcp
);
2281 pcp
->count
-= to_drain
;
2283 local_irq_restore(flags
);
2288 * Drain pcplists of the indicated processor and zone.
2290 * The processor must either be the current processor and the
2291 * thread pinned to the current processor or a processor that
2294 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2296 unsigned long flags
;
2297 struct per_cpu_pageset
*pset
;
2298 struct per_cpu_pages
*pcp
;
2300 local_irq_save(flags
);
2301 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2305 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2308 local_irq_restore(flags
);
2312 * Drain pcplists of all zones on the indicated processor.
2314 * The processor must either be the current processor and the
2315 * thread pinned to the current processor or a processor that
2318 static void drain_pages(unsigned int cpu
)
2322 for_each_populated_zone(zone
) {
2323 drain_pages_zone(cpu
, zone
);
2328 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2330 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2331 * the single zone's pages.
2333 void drain_local_pages(struct zone
*zone
)
2335 int cpu
= smp_processor_id();
2338 drain_pages_zone(cpu
, zone
);
2343 static void drain_local_pages_wq(struct work_struct
*work
)
2346 * drain_all_pages doesn't use proper cpu hotplug protection so
2347 * we can race with cpu offline when the WQ can move this from
2348 * a cpu pinned worker to an unbound one. We can operate on a different
2349 * cpu which is allright but we also have to make sure to not move to
2353 drain_local_pages(NULL
);
2358 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2360 * When zone parameter is non-NULL, spill just the single zone's pages.
2362 * Note that this can be extremely slow as the draining happens in a workqueue.
2364 void drain_all_pages(struct zone
*zone
)
2369 * Allocate in the BSS so we wont require allocation in
2370 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2372 static cpumask_t cpus_with_pcps
;
2374 /* Workqueues cannot recurse */
2375 if (current
->flags
& PF_WQ_WORKER
)
2379 * Do not drain if one is already in progress unless it's specific to
2380 * a zone. Such callers are primarily CMA and memory hotplug and need
2381 * the drain to be complete when the call returns.
2383 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2386 mutex_lock(&pcpu_drain_mutex
);
2390 * We don't care about racing with CPU hotplug event
2391 * as offline notification will cause the notified
2392 * cpu to drain that CPU pcps and on_each_cpu_mask
2393 * disables preemption as part of its processing
2395 for_each_online_cpu(cpu
) {
2396 struct per_cpu_pageset
*pcp
;
2398 bool has_pcps
= false;
2401 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2405 for_each_populated_zone(z
) {
2406 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2407 if (pcp
->pcp
.count
) {
2415 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2417 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2420 for_each_cpu(cpu
, &cpus_with_pcps
) {
2421 struct work_struct
*work
= per_cpu_ptr(&pcpu_drain
, cpu
);
2422 INIT_WORK(work
, drain_local_pages_wq
);
2423 schedule_work_on(cpu
, work
);
2425 for_each_cpu(cpu
, &cpus_with_pcps
)
2426 flush_work(per_cpu_ptr(&pcpu_drain
, cpu
));
2428 mutex_unlock(&pcpu_drain_mutex
);
2431 #ifdef CONFIG_HIBERNATION
2433 void mark_free_pages(struct zone
*zone
)
2435 unsigned long pfn
, max_zone_pfn
;
2436 unsigned long flags
;
2437 unsigned int order
, t
;
2440 if (zone_is_empty(zone
))
2443 spin_lock_irqsave(&zone
->lock
, flags
);
2445 max_zone_pfn
= zone_end_pfn(zone
);
2446 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2447 if (pfn_valid(pfn
)) {
2448 page
= pfn_to_page(pfn
);
2450 if (page_zone(page
) != zone
)
2453 if (!swsusp_page_is_forbidden(page
))
2454 swsusp_unset_page_free(page
);
2457 for_each_migratetype_order(order
, t
) {
2458 list_for_each_entry(page
,
2459 &zone
->free_area
[order
].free_list
[t
], lru
) {
2462 pfn
= page_to_pfn(page
);
2463 for (i
= 0; i
< (1UL << order
); i
++)
2464 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2467 spin_unlock_irqrestore(&zone
->lock
, flags
);
2469 #endif /* CONFIG_PM */
2472 * Free a 0-order page
2473 * cold == true ? free a cold page : free a hot page
2475 void free_hot_cold_page(struct page
*page
, bool cold
)
2477 struct zone
*zone
= page_zone(page
);
2478 struct per_cpu_pages
*pcp
;
2479 unsigned long pfn
= page_to_pfn(page
);
2482 if (in_interrupt()) {
2483 __free_pages_ok(page
, 0);
2487 if (!free_pcp_prepare(page
))
2490 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2491 set_pcppage_migratetype(page
, migratetype
);
2495 * We only track unmovable, reclaimable and movable on pcp lists.
2496 * Free ISOLATE pages back to the allocator because they are being
2497 * offlined but treat RESERVE as movable pages so we can get those
2498 * areas back if necessary. Otherwise, we may have to free
2499 * excessively into the page allocator
2501 if (migratetype
>= MIGRATE_PCPTYPES
) {
2502 if (unlikely(is_migrate_isolate(migratetype
))) {
2503 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2506 migratetype
= MIGRATE_MOVABLE
;
2509 __count_vm_event(PGFREE
);
2510 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2512 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2514 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2516 if (pcp
->count
>= pcp
->high
) {
2517 unsigned long batch
= READ_ONCE(pcp
->batch
);
2518 free_pcppages_bulk(zone
, batch
, pcp
);
2519 pcp
->count
-= batch
;
2527 * Free a list of 0-order pages
2529 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2531 struct page
*page
, *next
;
2533 list_for_each_entry_safe(page
, next
, list
, lru
) {
2534 trace_mm_page_free_batched(page
, cold
);
2535 free_hot_cold_page(page
, cold
);
2540 * split_page takes a non-compound higher-order page, and splits it into
2541 * n (1<<order) sub-pages: page[0..n]
2542 * Each sub-page must be freed individually.
2544 * Note: this is probably too low level an operation for use in drivers.
2545 * Please consult with lkml before using this in your driver.
2547 void split_page(struct page
*page
, unsigned int order
)
2551 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2552 VM_BUG_ON_PAGE(!page_count(page
), page
);
2554 #ifdef CONFIG_KMEMCHECK
2556 * Split shadow pages too, because free(page[0]) would
2557 * otherwise free the whole shadow.
2559 if (kmemcheck_page_is_tracked(page
))
2560 split_page(virt_to_page(page
[0].shadow
), order
);
2563 for (i
= 1; i
< (1 << order
); i
++)
2564 set_page_refcounted(page
+ i
);
2565 split_page_owner(page
, order
);
2567 EXPORT_SYMBOL_GPL(split_page
);
2569 int __isolate_free_page(struct page
*page
, unsigned int order
)
2571 unsigned long watermark
;
2575 BUG_ON(!PageBuddy(page
));
2577 zone
= page_zone(page
);
2578 mt
= get_pageblock_migratetype(page
);
2580 if (!is_migrate_isolate(mt
)) {
2582 * Obey watermarks as if the page was being allocated. We can
2583 * emulate a high-order watermark check with a raised order-0
2584 * watermark, because we already know our high-order page
2587 watermark
= min_wmark_pages(zone
) + (1UL << order
);
2588 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
2591 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2594 /* Remove page from free list */
2595 list_del(&page
->lru
);
2596 zone
->free_area
[order
].nr_free
--;
2597 rmv_page_order(page
);
2600 * Set the pageblock if the isolated page is at least half of a
2603 if (order
>= pageblock_order
- 1) {
2604 struct page
*endpage
= page
+ (1 << order
) - 1;
2605 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2606 int mt
= get_pageblock_migratetype(page
);
2607 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
2608 && mt
!= MIGRATE_HIGHATOMIC
)
2609 set_pageblock_migratetype(page
,
2615 return 1UL << order
;
2619 * Update NUMA hit/miss statistics
2621 * Must be called with interrupts disabled.
2623 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
2626 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2628 if (z
->node
!= numa_node_id())
2629 local_stat
= NUMA_OTHER
;
2631 if (z
->node
== preferred_zone
->node
)
2632 __inc_zone_state(z
, NUMA_HIT
);
2634 __inc_zone_state(z
, NUMA_MISS
);
2635 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2637 __inc_zone_state(z
, local_stat
);
2641 /* Remove page from the per-cpu list, caller must protect the list */
2642 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
2643 bool cold
, struct per_cpu_pages
*pcp
,
2644 struct list_head
*list
)
2648 VM_BUG_ON(in_interrupt());
2651 if (list_empty(list
)) {
2652 pcp
->count
+= rmqueue_bulk(zone
, 0,
2655 if (unlikely(list_empty(list
)))
2660 page
= list_last_entry(list
, struct page
, lru
);
2662 page
= list_first_entry(list
, struct page
, lru
);
2664 list_del(&page
->lru
);
2666 } while (check_new_pcp(page
));
2671 /* Lock and remove page from the per-cpu list */
2672 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
2673 struct zone
*zone
, unsigned int order
,
2674 gfp_t gfp_flags
, int migratetype
)
2676 struct per_cpu_pages
*pcp
;
2677 struct list_head
*list
;
2678 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2682 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2683 list
= &pcp
->lists
[migratetype
];
2684 page
= __rmqueue_pcplist(zone
, migratetype
, cold
, pcp
, list
);
2686 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2687 zone_statistics(preferred_zone
, zone
);
2694 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2697 struct page
*rmqueue(struct zone
*preferred_zone
,
2698 struct zone
*zone
, unsigned int order
,
2699 gfp_t gfp_flags
, unsigned int alloc_flags
,
2702 unsigned long flags
;
2705 if (likely(order
== 0) && !in_interrupt()) {
2706 page
= rmqueue_pcplist(preferred_zone
, zone
, order
,
2707 gfp_flags
, migratetype
);
2712 * We most definitely don't want callers attempting to
2713 * allocate greater than order-1 page units with __GFP_NOFAIL.
2715 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2716 spin_lock_irqsave(&zone
->lock
, flags
);
2720 if (alloc_flags
& ALLOC_HARDER
) {
2721 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2723 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2726 page
= __rmqueue(zone
, order
, migratetype
);
2727 } while (page
&& check_new_pages(page
, order
));
2728 spin_unlock(&zone
->lock
);
2731 __mod_zone_freepage_state(zone
, -(1 << order
),
2732 get_pcppage_migratetype(page
));
2734 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2735 zone_statistics(preferred_zone
, zone
);
2736 local_irq_restore(flags
);
2739 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
2743 local_irq_restore(flags
);
2747 #ifdef CONFIG_FAIL_PAGE_ALLOC
2750 struct fault_attr attr
;
2752 bool ignore_gfp_highmem
;
2753 bool ignore_gfp_reclaim
;
2755 } fail_page_alloc
= {
2756 .attr
= FAULT_ATTR_INITIALIZER
,
2757 .ignore_gfp_reclaim
= true,
2758 .ignore_gfp_highmem
= true,
2762 static int __init
setup_fail_page_alloc(char *str
)
2764 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2766 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2768 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2770 if (order
< fail_page_alloc
.min_order
)
2772 if (gfp_mask
& __GFP_NOFAIL
)
2774 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2776 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2777 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2780 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2783 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2785 static int __init
fail_page_alloc_debugfs(void)
2787 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2790 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2791 &fail_page_alloc
.attr
);
2793 return PTR_ERR(dir
);
2795 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2796 &fail_page_alloc
.ignore_gfp_reclaim
))
2798 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2799 &fail_page_alloc
.ignore_gfp_highmem
))
2801 if (!debugfs_create_u32("min-order", mode
, dir
,
2802 &fail_page_alloc
.min_order
))
2807 debugfs_remove_recursive(dir
);
2812 late_initcall(fail_page_alloc_debugfs
);
2814 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2816 #else /* CONFIG_FAIL_PAGE_ALLOC */
2818 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2823 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2826 * Return true if free base pages are above 'mark'. For high-order checks it
2827 * will return true of the order-0 watermark is reached and there is at least
2828 * one free page of a suitable size. Checking now avoids taking the zone lock
2829 * to check in the allocation paths if no pages are free.
2831 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2832 int classzone_idx
, unsigned int alloc_flags
,
2837 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2839 /* free_pages may go negative - that's OK */
2840 free_pages
-= (1 << order
) - 1;
2842 if (alloc_flags
& ALLOC_HIGH
)
2846 * If the caller does not have rights to ALLOC_HARDER then subtract
2847 * the high-atomic reserves. This will over-estimate the size of the
2848 * atomic reserve but it avoids a search.
2850 if (likely(!alloc_harder
))
2851 free_pages
-= z
->nr_reserved_highatomic
;
2856 /* If allocation can't use CMA areas don't use free CMA pages */
2857 if (!(alloc_flags
& ALLOC_CMA
))
2858 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2862 * Check watermarks for an order-0 allocation request. If these
2863 * are not met, then a high-order request also cannot go ahead
2864 * even if a suitable page happened to be free.
2866 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2869 /* If this is an order-0 request then the watermark is fine */
2873 /* For a high-order request, check at least one suitable page is free */
2874 for (o
= order
; o
< MAX_ORDER
; o
++) {
2875 struct free_area
*area
= &z
->free_area
[o
];
2884 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2885 if (!list_empty(&area
->free_list
[mt
]))
2890 if ((alloc_flags
& ALLOC_CMA
) &&
2891 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2899 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2900 int classzone_idx
, unsigned int alloc_flags
)
2902 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2903 zone_page_state(z
, NR_FREE_PAGES
));
2906 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
2907 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
2909 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2913 /* If allocation can't use CMA areas don't use free CMA pages */
2914 if (!(alloc_flags
& ALLOC_CMA
))
2915 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2919 * Fast check for order-0 only. If this fails then the reserves
2920 * need to be calculated. There is a corner case where the check
2921 * passes but only the high-order atomic reserve are free. If
2922 * the caller is !atomic then it'll uselessly search the free
2923 * list. That corner case is then slower but it is harmless.
2925 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
2928 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2932 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2933 unsigned long mark
, int classzone_idx
)
2935 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2937 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2938 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2940 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2945 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2947 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
2950 #else /* CONFIG_NUMA */
2951 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2955 #endif /* CONFIG_NUMA */
2958 * get_page_from_freelist goes through the zonelist trying to allocate
2961 static struct page
*
2962 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2963 const struct alloc_context
*ac
)
2965 struct zoneref
*z
= ac
->preferred_zoneref
;
2967 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
2970 * Scan zonelist, looking for a zone with enough free.
2971 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2973 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
2978 if (cpusets_enabled() &&
2979 (alloc_flags
& ALLOC_CPUSET
) &&
2980 !__cpuset_zone_allowed(zone
, gfp_mask
))
2983 * When allocating a page cache page for writing, we
2984 * want to get it from a node that is within its dirty
2985 * limit, such that no single node holds more than its
2986 * proportional share of globally allowed dirty pages.
2987 * The dirty limits take into account the node's
2988 * lowmem reserves and high watermark so that kswapd
2989 * should be able to balance it without having to
2990 * write pages from its LRU list.
2992 * XXX: For now, allow allocations to potentially
2993 * exceed the per-node dirty limit in the slowpath
2994 * (spread_dirty_pages unset) before going into reclaim,
2995 * which is important when on a NUMA setup the allowed
2996 * nodes are together not big enough to reach the
2997 * global limit. The proper fix for these situations
2998 * will require awareness of nodes in the
2999 * dirty-throttling and the flusher threads.
3001 if (ac
->spread_dirty_pages
) {
3002 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3005 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3006 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3011 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
3012 if (!zone_watermark_fast(zone
, order
, mark
,
3013 ac_classzone_idx(ac
), alloc_flags
)) {
3016 /* Checked here to keep the fast path fast */
3017 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3018 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3021 if (node_reclaim_mode
== 0 ||
3022 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3025 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3027 case NODE_RECLAIM_NOSCAN
:
3030 case NODE_RECLAIM_FULL
:
3031 /* scanned but unreclaimable */
3034 /* did we reclaim enough */
3035 if (zone_watermark_ok(zone
, order
, mark
,
3036 ac_classzone_idx(ac
), alloc_flags
))
3044 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3045 gfp_mask
, alloc_flags
, ac
->migratetype
);
3047 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3050 * If this is a high-order atomic allocation then check
3051 * if the pageblock should be reserved for the future
3053 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3054 reserve_highatomic_pageblock(page
, zone
, order
);
3064 * Large machines with many possible nodes should not always dump per-node
3065 * meminfo in irq context.
3067 static inline bool should_suppress_show_mem(void)
3072 ret
= in_interrupt();
3077 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3079 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3080 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3082 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs
))
3086 * This documents exceptions given to allocations in certain
3087 * contexts that are allowed to allocate outside current's set
3090 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3091 if (test_thread_flag(TIF_MEMDIE
) ||
3092 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3093 filter
&= ~SHOW_MEM_FILTER_NODES
;
3094 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3095 filter
&= ~SHOW_MEM_FILTER_NODES
;
3097 show_mem(filter
, nodemask
);
3100 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3102 struct va_format vaf
;
3104 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3105 DEFAULT_RATELIMIT_BURST
);
3107 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
3108 debug_guardpage_minorder() > 0)
3111 pr_warn("%s: ", current
->comm
);
3113 va_start(args
, fmt
);
3116 pr_cont("%pV", &vaf
);
3119 pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask
, &gfp_mask
);
3121 pr_cont("%*pbl\n", nodemask_pr_args(nodemask
));
3123 pr_cont("(null)\n");
3125 cpuset_print_current_mems_allowed();
3128 warn_alloc_show_mem(gfp_mask
, nodemask
);
3131 static inline struct page
*
3132 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3133 unsigned int alloc_flags
,
3134 const struct alloc_context
*ac
)
3138 page
= get_page_from_freelist(gfp_mask
, order
,
3139 alloc_flags
|ALLOC_CPUSET
, ac
);
3141 * fallback to ignore cpuset restriction if our nodes
3145 page
= get_page_from_freelist(gfp_mask
, order
,
3151 static inline struct page
*
3152 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3153 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3155 struct oom_control oc
= {
3156 .zonelist
= ac
->zonelist
,
3157 .nodemask
= ac
->nodemask
,
3159 .gfp_mask
= gfp_mask
,
3164 *did_some_progress
= 0;
3167 * Acquire the oom lock. If that fails, somebody else is
3168 * making progress for us.
3170 if (!mutex_trylock(&oom_lock
)) {
3171 *did_some_progress
= 1;
3172 schedule_timeout_uninterruptible(1);
3177 * Go through the zonelist yet one more time, keep very high watermark
3178 * here, this is only to catch a parallel oom killing, we must fail if
3179 * we're still under heavy pressure.
3181 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3182 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3186 /* Coredumps can quickly deplete all memory reserves */
3187 if (current
->flags
& PF_DUMPCORE
)
3189 /* The OOM killer will not help higher order allocs */
3190 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3192 /* The OOM killer does not needlessly kill tasks for lowmem */
3193 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3195 if (pm_suspended_storage())
3198 * XXX: GFP_NOFS allocations should rather fail than rely on
3199 * other request to make a forward progress.
3200 * We are in an unfortunate situation where out_of_memory cannot
3201 * do much for this context but let's try it to at least get
3202 * access to memory reserved if the current task is killed (see
3203 * out_of_memory). Once filesystems are ready to handle allocation
3204 * failures more gracefully we should just bail out here.
3207 /* The OOM killer may not free memory on a specific node */
3208 if (gfp_mask
& __GFP_THISNODE
)
3211 /* Exhausted what can be done so it's blamo time */
3212 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3213 *did_some_progress
= 1;
3216 * Help non-failing allocations by giving them access to memory
3219 if (gfp_mask
& __GFP_NOFAIL
)
3220 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3221 ALLOC_NO_WATERMARKS
, ac
);
3224 mutex_unlock(&oom_lock
);
3229 * Maximum number of compaction retries wit a progress before OOM
3230 * killer is consider as the only way to move forward.
3232 #define MAX_COMPACT_RETRIES 16
3234 #ifdef CONFIG_COMPACTION
3235 /* Try memory compaction for high-order allocations before reclaim */
3236 static struct page
*
3237 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3238 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3239 enum compact_priority prio
, enum compact_result
*compact_result
)
3246 current
->flags
|= PF_MEMALLOC
;
3247 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3249 current
->flags
&= ~PF_MEMALLOC
;
3251 if (*compact_result
<= COMPACT_INACTIVE
)
3255 * At least in one zone compaction wasn't deferred or skipped, so let's
3256 * count a compaction stall
3258 count_vm_event(COMPACTSTALL
);
3260 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3263 struct zone
*zone
= page_zone(page
);
3265 zone
->compact_blockskip_flush
= false;
3266 compaction_defer_reset(zone
, order
, true);
3267 count_vm_event(COMPACTSUCCESS
);
3272 * It's bad if compaction run occurs and fails. The most likely reason
3273 * is that pages exist, but not enough to satisfy watermarks.
3275 count_vm_event(COMPACTFAIL
);
3283 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3284 enum compact_result compact_result
,
3285 enum compact_priority
*compact_priority
,
3286 int *compaction_retries
)
3288 int max_retries
= MAX_COMPACT_RETRIES
;
3291 int retries
= *compaction_retries
;
3292 enum compact_priority priority
= *compact_priority
;
3297 if (compaction_made_progress(compact_result
))
3298 (*compaction_retries
)++;
3301 * compaction considers all the zone as desperately out of memory
3302 * so it doesn't really make much sense to retry except when the
3303 * failure could be caused by insufficient priority
3305 if (compaction_failed(compact_result
))
3306 goto check_priority
;
3309 * make sure the compaction wasn't deferred or didn't bail out early
3310 * due to locks contention before we declare that we should give up.
3311 * But do not retry if the given zonelist is not suitable for
3314 if (compaction_withdrawn(compact_result
)) {
3315 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3320 * !costly requests are much more important than __GFP_REPEAT
3321 * costly ones because they are de facto nofail and invoke OOM
3322 * killer to move on while costly can fail and users are ready
3323 * to cope with that. 1/4 retries is rather arbitrary but we
3324 * would need much more detailed feedback from compaction to
3325 * make a better decision.
3327 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3329 if (*compaction_retries
<= max_retries
) {
3335 * Make sure there are attempts at the highest priority if we exhausted
3336 * all retries or failed at the lower priorities.
3339 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3340 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3342 if (*compact_priority
> min_priority
) {
3343 (*compact_priority
)--;
3344 *compaction_retries
= 0;
3348 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3352 static inline struct page
*
3353 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3354 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3355 enum compact_priority prio
, enum compact_result
*compact_result
)
3357 *compact_result
= COMPACT_SKIPPED
;
3362 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3363 enum compact_result compact_result
,
3364 enum compact_priority
*compact_priority
,
3365 int *compaction_retries
)
3370 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3374 * There are setups with compaction disabled which would prefer to loop
3375 * inside the allocator rather than hit the oom killer prematurely.
3376 * Let's give them a good hope and keep retrying while the order-0
3377 * watermarks are OK.
3379 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3381 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3382 ac_classzone_idx(ac
), alloc_flags
))
3387 #endif /* CONFIG_COMPACTION */
3389 /* Perform direct synchronous page reclaim */
3391 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3392 const struct alloc_context
*ac
)
3394 struct reclaim_state reclaim_state
;
3399 /* We now go into synchronous reclaim */
3400 cpuset_memory_pressure_bump();
3401 current
->flags
|= PF_MEMALLOC
;
3402 lockdep_set_current_reclaim_state(gfp_mask
);
3403 reclaim_state
.reclaimed_slab
= 0;
3404 current
->reclaim_state
= &reclaim_state
;
3406 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3409 current
->reclaim_state
= NULL
;
3410 lockdep_clear_current_reclaim_state();
3411 current
->flags
&= ~PF_MEMALLOC
;
3418 /* The really slow allocator path where we enter direct reclaim */
3419 static inline struct page
*
3420 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3421 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3422 unsigned long *did_some_progress
)
3424 struct page
*page
= NULL
;
3425 bool drained
= false;
3427 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3428 if (unlikely(!(*did_some_progress
)))
3432 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3435 * If an allocation failed after direct reclaim, it could be because
3436 * pages are pinned on the per-cpu lists or in high alloc reserves.
3437 * Shrink them them and try again
3439 if (!page
&& !drained
) {
3440 unreserve_highatomic_pageblock(ac
, false);
3441 drain_all_pages(NULL
);
3449 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3453 pg_data_t
*last_pgdat
= NULL
;
3455 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3456 ac
->high_zoneidx
, ac
->nodemask
) {
3457 if (last_pgdat
!= zone
->zone_pgdat
)
3458 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3459 last_pgdat
= zone
->zone_pgdat
;
3463 static inline unsigned int
3464 gfp_to_alloc_flags(gfp_t gfp_mask
)
3466 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3468 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3469 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3472 * The caller may dip into page reserves a bit more if the caller
3473 * cannot run direct reclaim, or if the caller has realtime scheduling
3474 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3475 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3477 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3479 if (gfp_mask
& __GFP_ATOMIC
) {
3481 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3482 * if it can't schedule.
3484 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3485 alloc_flags
|= ALLOC_HARDER
;
3487 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3488 * comment for __cpuset_node_allowed().
3490 alloc_flags
&= ~ALLOC_CPUSET
;
3491 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3492 alloc_flags
|= ALLOC_HARDER
;
3495 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3496 alloc_flags
|= ALLOC_CMA
;
3501 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3503 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3506 if (gfp_mask
& __GFP_MEMALLOC
)
3508 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3510 if (!in_interrupt() &&
3511 ((current
->flags
& PF_MEMALLOC
) ||
3512 unlikely(test_thread_flag(TIF_MEMDIE
))))
3519 * Maximum number of reclaim retries without any progress before OOM killer
3520 * is consider as the only way to move forward.
3522 #define MAX_RECLAIM_RETRIES 16
3525 * Checks whether it makes sense to retry the reclaim to make a forward progress
3526 * for the given allocation request.
3527 * The reclaim feedback represented by did_some_progress (any progress during
3528 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3529 * any progress in a row) is considered as well as the reclaimable pages on the
3530 * applicable zone list (with a backoff mechanism which is a function of
3531 * no_progress_loops).
3533 * Returns true if a retry is viable or false to enter the oom path.
3536 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3537 struct alloc_context
*ac
, int alloc_flags
,
3538 bool did_some_progress
, int *no_progress_loops
)
3544 * Costly allocations might have made a progress but this doesn't mean
3545 * their order will become available due to high fragmentation so
3546 * always increment the no progress counter for them
3548 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3549 *no_progress_loops
= 0;
3551 (*no_progress_loops
)++;
3554 * Make sure we converge to OOM if we cannot make any progress
3555 * several times in the row.
3557 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
3558 /* Before OOM, exhaust highatomic_reserve */
3559 return unreserve_highatomic_pageblock(ac
, true);
3563 * Keep reclaiming pages while there is a chance this will lead
3564 * somewhere. If none of the target zones can satisfy our allocation
3565 * request even if all reclaimable pages are considered then we are
3566 * screwed and have to go OOM.
3568 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3570 unsigned long available
;
3571 unsigned long reclaimable
;
3572 unsigned long min_wmark
= min_wmark_pages(zone
);
3575 available
= reclaimable
= zone_reclaimable_pages(zone
);
3576 available
-= DIV_ROUND_UP((*no_progress_loops
) * available
,
3577 MAX_RECLAIM_RETRIES
);
3578 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3581 * Would the allocation succeed if we reclaimed the whole
3584 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
3585 ac_classzone_idx(ac
), alloc_flags
, available
);
3586 trace_reclaim_retry_zone(z
, order
, reclaimable
,
3587 available
, min_wmark
, *no_progress_loops
, wmark
);
3590 * If we didn't make any progress and have a lot of
3591 * dirty + writeback pages then we should wait for
3592 * an IO to complete to slow down the reclaim and
3593 * prevent from pre mature OOM
3595 if (!did_some_progress
) {
3596 unsigned long write_pending
;
3598 write_pending
= zone_page_state_snapshot(zone
,
3599 NR_ZONE_WRITE_PENDING
);
3601 if (2 * write_pending
> reclaimable
) {
3602 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3608 * Memory allocation/reclaim might be called from a WQ
3609 * context and the current implementation of the WQ
3610 * concurrency control doesn't recognize that
3611 * a particular WQ is congested if the worker thread is
3612 * looping without ever sleeping. Therefore we have to
3613 * do a short sleep here rather than calling
3616 if (current
->flags
& PF_WQ_WORKER
)
3617 schedule_timeout_uninterruptible(1);
3628 static inline struct page
*
3629 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3630 struct alloc_context
*ac
)
3632 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3633 struct page
*page
= NULL
;
3634 unsigned int alloc_flags
;
3635 unsigned long did_some_progress
;
3636 enum compact_priority compact_priority
;
3637 enum compact_result compact_result
;
3638 int compaction_retries
;
3639 int no_progress_loops
;
3640 unsigned long alloc_start
= jiffies
;
3641 unsigned int stall_timeout
= 10 * HZ
;
3642 unsigned int cpuset_mems_cookie
;
3645 * In the slowpath, we sanity check order to avoid ever trying to
3646 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3647 * be using allocators in order of preference for an area that is
3650 if (order
>= MAX_ORDER
) {
3651 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3656 * We also sanity check to catch abuse of atomic reserves being used by
3657 * callers that are not in atomic context.
3659 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3660 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3661 gfp_mask
&= ~__GFP_ATOMIC
;
3664 compaction_retries
= 0;
3665 no_progress_loops
= 0;
3666 compact_priority
= DEF_COMPACT_PRIORITY
;
3667 cpuset_mems_cookie
= read_mems_allowed_begin();
3670 * The fast path uses conservative alloc_flags to succeed only until
3671 * kswapd needs to be woken up, and to avoid the cost of setting up
3672 * alloc_flags precisely. So we do that now.
3674 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3677 * We need to recalculate the starting point for the zonelist iterator
3678 * because we might have used different nodemask in the fast path, or
3679 * there was a cpuset modification and we are retrying - otherwise we
3680 * could end up iterating over non-eligible zones endlessly.
3682 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3683 ac
->high_zoneidx
, ac
->nodemask
);
3684 if (!ac
->preferred_zoneref
->zone
)
3687 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3688 wake_all_kswapds(order
, ac
);
3691 * The adjusted alloc_flags might result in immediate success, so try
3694 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3699 * For costly allocations, try direct compaction first, as it's likely
3700 * that we have enough base pages and don't need to reclaim. Don't try
3701 * that for allocations that are allowed to ignore watermarks, as the
3702 * ALLOC_NO_WATERMARKS attempt didn't yet happen.
3704 if (can_direct_reclaim
&& order
> PAGE_ALLOC_COSTLY_ORDER
&&
3705 !gfp_pfmemalloc_allowed(gfp_mask
)) {
3706 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
3708 INIT_COMPACT_PRIORITY
,
3714 * Checks for costly allocations with __GFP_NORETRY, which
3715 * includes THP page fault allocations
3717 if (gfp_mask
& __GFP_NORETRY
) {
3719 * If compaction is deferred for high-order allocations,
3720 * it is because sync compaction recently failed. If
3721 * this is the case and the caller requested a THP
3722 * allocation, we do not want to heavily disrupt the
3723 * system, so we fail the allocation instead of entering
3726 if (compact_result
== COMPACT_DEFERRED
)
3730 * Looks like reclaim/compaction is worth trying, but
3731 * sync compaction could be very expensive, so keep
3732 * using async compaction.
3734 compact_priority
= INIT_COMPACT_PRIORITY
;
3739 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3740 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3741 wake_all_kswapds(order
, ac
);
3743 if (gfp_pfmemalloc_allowed(gfp_mask
))
3744 alloc_flags
= ALLOC_NO_WATERMARKS
;
3747 * Reset the zonelist iterators if memory policies can be ignored.
3748 * These allocations are high priority and system rather than user
3751 if (!(alloc_flags
& ALLOC_CPUSET
) || (alloc_flags
& ALLOC_NO_WATERMARKS
)) {
3752 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3753 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3754 ac
->high_zoneidx
, ac
->nodemask
);
3757 /* Attempt with potentially adjusted zonelist and alloc_flags */
3758 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3762 /* Caller is not willing to reclaim, we can't balance anything */
3763 if (!can_direct_reclaim
)
3766 /* Make sure we know about allocations which stall for too long */
3767 if (time_after(jiffies
, alloc_start
+ stall_timeout
)) {
3768 warn_alloc(gfp_mask
, ac
->nodemask
,
3769 "page allocation stalls for %ums, order:%u",
3770 jiffies_to_msecs(jiffies
-alloc_start
), order
);
3771 stall_timeout
+= 10 * HZ
;
3774 /* Avoid recursion of direct reclaim */
3775 if (current
->flags
& PF_MEMALLOC
)
3778 /* Try direct reclaim and then allocating */
3779 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3780 &did_some_progress
);
3784 /* Try direct compaction and then allocating */
3785 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3786 compact_priority
, &compact_result
);
3790 /* Do not loop if specifically requested */
3791 if (gfp_mask
& __GFP_NORETRY
)
3795 * Do not retry costly high order allocations unless they are
3798 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_REPEAT
))
3801 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3802 did_some_progress
> 0, &no_progress_loops
))
3806 * It doesn't make any sense to retry for the compaction if the order-0
3807 * reclaim is not able to make any progress because the current
3808 * implementation of the compaction depends on the sufficient amount
3809 * of free memory (see __compaction_suitable)
3811 if (did_some_progress
> 0 &&
3812 should_compact_retry(ac
, order
, alloc_flags
,
3813 compact_result
, &compact_priority
,
3814 &compaction_retries
))
3818 * It's possible we raced with cpuset update so the OOM would be
3819 * premature (see below the nopage: label for full explanation).
3821 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3824 /* Reclaim has failed us, start killing things */
3825 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3829 /* Avoid allocations with no watermarks from looping endlessly */
3830 if (test_thread_flag(TIF_MEMDIE
))
3833 /* Retry as long as the OOM killer is making progress */
3834 if (did_some_progress
) {
3835 no_progress_loops
= 0;
3841 * When updating a task's mems_allowed or mempolicy nodemask, it is
3842 * possible to race with parallel threads in such a way that our
3843 * allocation can fail while the mask is being updated. If we are about
3844 * to fail, check if the cpuset changed during allocation and if so,
3847 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3851 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
3854 if (gfp_mask
& __GFP_NOFAIL
) {
3856 * All existing users of the __GFP_NOFAIL are blockable, so warn
3857 * of any new users that actually require GFP_NOWAIT
3859 if (WARN_ON_ONCE(!can_direct_reclaim
))
3863 * PF_MEMALLOC request from this context is rather bizarre
3864 * because we cannot reclaim anything and only can loop waiting
3865 * for somebody to do a work for us
3867 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
3870 * non failing costly orders are a hard requirement which we
3871 * are not prepared for much so let's warn about these users
3872 * so that we can identify them and convert them to something
3875 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
3878 * Help non-failing allocations by giving them access to memory
3879 * reserves but do not use ALLOC_NO_WATERMARKS because this
3880 * could deplete whole memory reserves which would just make
3881 * the situation worse
3883 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
3891 warn_alloc(gfp_mask
, ac
->nodemask
,
3892 "page allocation failure: order:%u", order
);
3897 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
3898 struct zonelist
*zonelist
, nodemask_t
*nodemask
,
3899 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
3900 unsigned int *alloc_flags
)
3902 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
3903 ac
->zonelist
= zonelist
;
3904 ac
->nodemask
= nodemask
;
3905 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
3907 if (cpusets_enabled()) {
3908 *alloc_mask
|= __GFP_HARDWALL
;
3910 ac
->nodemask
= &cpuset_current_mems_allowed
;
3912 *alloc_flags
|= ALLOC_CPUSET
;
3915 lockdep_trace_alloc(gfp_mask
);
3917 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3919 if (should_fail_alloc_page(gfp_mask
, order
))
3922 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
3923 *alloc_flags
|= ALLOC_CMA
;
3928 /* Determine whether to spread dirty pages and what the first usable zone */
3929 static inline void finalise_ac(gfp_t gfp_mask
,
3930 unsigned int order
, struct alloc_context
*ac
)
3932 /* Dirty zone balancing only done in the fast path */
3933 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3936 * The preferred zone is used for statistics but crucially it is
3937 * also used as the starting point for the zonelist iterator. It
3938 * may get reset for allocations that ignore memory policies.
3940 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3941 ac
->high_zoneidx
, ac
->nodemask
);
3945 * This is the 'heart' of the zoned buddy allocator.
3948 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3949 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3952 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
3953 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
3954 struct alloc_context ac
= { };
3956 gfp_mask
&= gfp_allowed_mask
;
3957 if (!prepare_alloc_pages(gfp_mask
, order
, zonelist
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
3960 finalise_ac(gfp_mask
, order
, &ac
);
3962 /* First allocation attempt */
3963 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3968 * Runtime PM, block IO and its error handling path can deadlock
3969 * because I/O on the device might not complete.
3971 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3972 ac
.spread_dirty_pages
= false;
3975 * Restore the original nodemask if it was potentially replaced with
3976 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3978 if (unlikely(ac
.nodemask
!= nodemask
))
3979 ac
.nodemask
= nodemask
;
3981 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3984 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
3985 unlikely(memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
3986 __free_pages(page
, order
);
3990 if (kmemcheck_enabled
&& page
)
3991 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3993 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3997 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4000 * Common helper functions.
4002 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4007 * __get_free_pages() returns a 32-bit address, which cannot represent
4010 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
4012 page
= alloc_pages(gfp_mask
, order
);
4015 return (unsigned long) page_address(page
);
4017 EXPORT_SYMBOL(__get_free_pages
);
4019 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4021 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4023 EXPORT_SYMBOL(get_zeroed_page
);
4025 void __free_pages(struct page
*page
, unsigned int order
)
4027 if (put_page_testzero(page
)) {
4029 free_hot_cold_page(page
, false);
4031 __free_pages_ok(page
, order
);
4035 EXPORT_SYMBOL(__free_pages
);
4037 void free_pages(unsigned long addr
, unsigned int order
)
4040 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4041 __free_pages(virt_to_page((void *)addr
), order
);
4045 EXPORT_SYMBOL(free_pages
);
4049 * An arbitrary-length arbitrary-offset area of memory which resides
4050 * within a 0 or higher order page. Multiple fragments within that page
4051 * are individually refcounted, in the page's reference counter.
4053 * The page_frag functions below provide a simple allocation framework for
4054 * page fragments. This is used by the network stack and network device
4055 * drivers to provide a backing region of memory for use as either an
4056 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4058 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4061 struct page
*page
= NULL
;
4062 gfp_t gfp
= gfp_mask
;
4064 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4065 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4067 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4068 PAGE_FRAG_CACHE_MAX_ORDER
);
4069 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4071 if (unlikely(!page
))
4072 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4074 nc
->va
= page
? page_address(page
) : NULL
;
4079 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4081 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4083 if (page_ref_sub_and_test(page
, count
)) {
4084 unsigned int order
= compound_order(page
);
4087 free_hot_cold_page(page
, false);
4089 __free_pages_ok(page
, order
);
4092 EXPORT_SYMBOL(__page_frag_cache_drain
);
4094 void *page_frag_alloc(struct page_frag_cache
*nc
,
4095 unsigned int fragsz
, gfp_t gfp_mask
)
4097 unsigned int size
= PAGE_SIZE
;
4101 if (unlikely(!nc
->va
)) {
4103 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4107 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4108 /* if size can vary use size else just use PAGE_SIZE */
4111 /* Even if we own the page, we do not use atomic_set().
4112 * This would break get_page_unless_zero() users.
4114 page_ref_add(page
, size
- 1);
4116 /* reset page count bias and offset to start of new frag */
4117 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4118 nc
->pagecnt_bias
= size
;
4122 offset
= nc
->offset
- fragsz
;
4123 if (unlikely(offset
< 0)) {
4124 page
= virt_to_page(nc
->va
);
4126 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4129 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4130 /* if size can vary use size else just use PAGE_SIZE */
4133 /* OK, page count is 0, we can safely set it */
4134 set_page_count(page
, size
);
4136 /* reset page count bias and offset to start of new frag */
4137 nc
->pagecnt_bias
= size
;
4138 offset
= size
- fragsz
;
4142 nc
->offset
= offset
;
4144 return nc
->va
+ offset
;
4146 EXPORT_SYMBOL(page_frag_alloc
);
4149 * Frees a page fragment allocated out of either a compound or order 0 page.
4151 void page_frag_free(void *addr
)
4153 struct page
*page
= virt_to_head_page(addr
);
4155 if (unlikely(put_page_testzero(page
)))
4156 __free_pages_ok(page
, compound_order(page
));
4158 EXPORT_SYMBOL(page_frag_free
);
4160 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4164 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4165 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4167 split_page(virt_to_page((void *)addr
), order
);
4168 while (used
< alloc_end
) {
4173 return (void *)addr
;
4177 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4178 * @size: the number of bytes to allocate
4179 * @gfp_mask: GFP flags for the allocation
4181 * This function is similar to alloc_pages(), except that it allocates the
4182 * minimum number of pages to satisfy the request. alloc_pages() can only
4183 * allocate memory in power-of-two pages.
4185 * This function is also limited by MAX_ORDER.
4187 * Memory allocated by this function must be released by free_pages_exact().
4189 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4191 unsigned int order
= get_order(size
);
4194 addr
= __get_free_pages(gfp_mask
, order
);
4195 return make_alloc_exact(addr
, order
, size
);
4197 EXPORT_SYMBOL(alloc_pages_exact
);
4200 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4202 * @nid: the preferred node ID where memory should be allocated
4203 * @size: the number of bytes to allocate
4204 * @gfp_mask: GFP flags for the allocation
4206 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4209 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4211 unsigned int order
= get_order(size
);
4212 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4215 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4219 * free_pages_exact - release memory allocated via alloc_pages_exact()
4220 * @virt: the value returned by alloc_pages_exact.
4221 * @size: size of allocation, same value as passed to alloc_pages_exact().
4223 * Release the memory allocated by a previous call to alloc_pages_exact.
4225 void free_pages_exact(void *virt
, size_t size
)
4227 unsigned long addr
= (unsigned long)virt
;
4228 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4230 while (addr
< end
) {
4235 EXPORT_SYMBOL(free_pages_exact
);
4238 * nr_free_zone_pages - count number of pages beyond high watermark
4239 * @offset: The zone index of the highest zone
4241 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4242 * high watermark within all zones at or below a given zone index. For each
4243 * zone, the number of pages is calculated as:
4244 * managed_pages - high_pages
4246 static unsigned long nr_free_zone_pages(int offset
)
4251 /* Just pick one node, since fallback list is circular */
4252 unsigned long sum
= 0;
4254 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4256 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4257 unsigned long size
= zone
->managed_pages
;
4258 unsigned long high
= high_wmark_pages(zone
);
4267 * nr_free_buffer_pages - count number of pages beyond high watermark
4269 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4270 * watermark within ZONE_DMA and ZONE_NORMAL.
4272 unsigned long nr_free_buffer_pages(void)
4274 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4276 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4279 * nr_free_pagecache_pages - count number of pages beyond high watermark
4281 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4282 * high watermark within all zones.
4284 unsigned long nr_free_pagecache_pages(void)
4286 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4289 static inline void show_node(struct zone
*zone
)
4291 if (IS_ENABLED(CONFIG_NUMA
))
4292 printk("Node %d ", zone_to_nid(zone
));
4295 long si_mem_available(void)
4298 unsigned long pagecache
;
4299 unsigned long wmark_low
= 0;
4300 unsigned long pages
[NR_LRU_LISTS
];
4304 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4305 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
4308 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4311 * Estimate the amount of memory available for userspace allocations,
4312 * without causing swapping.
4314 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4317 * Not all the page cache can be freed, otherwise the system will
4318 * start swapping. Assume at least half of the page cache, or the
4319 * low watermark worth of cache, needs to stay.
4321 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4322 pagecache
-= min(pagecache
/ 2, wmark_low
);
4323 available
+= pagecache
;
4326 * Part of the reclaimable slab consists of items that are in use,
4327 * and cannot be freed. Cap this estimate at the low watermark.
4329 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4330 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4336 EXPORT_SYMBOL_GPL(si_mem_available
);
4338 void si_meminfo(struct sysinfo
*val
)
4340 val
->totalram
= totalram_pages
;
4341 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4342 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4343 val
->bufferram
= nr_blockdev_pages();
4344 val
->totalhigh
= totalhigh_pages
;
4345 val
->freehigh
= nr_free_highpages();
4346 val
->mem_unit
= PAGE_SIZE
;
4349 EXPORT_SYMBOL(si_meminfo
);
4352 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4354 int zone_type
; /* needs to be signed */
4355 unsigned long managed_pages
= 0;
4356 unsigned long managed_highpages
= 0;
4357 unsigned long free_highpages
= 0;
4358 pg_data_t
*pgdat
= NODE_DATA(nid
);
4360 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4361 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4362 val
->totalram
= managed_pages
;
4363 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4364 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4365 #ifdef CONFIG_HIGHMEM
4366 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4367 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4369 if (is_highmem(zone
)) {
4370 managed_highpages
+= zone
->managed_pages
;
4371 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4374 val
->totalhigh
= managed_highpages
;
4375 val
->freehigh
= free_highpages
;
4377 val
->totalhigh
= managed_highpages
;
4378 val
->freehigh
= free_highpages
;
4380 val
->mem_unit
= PAGE_SIZE
;
4385 * Determine whether the node should be displayed or not, depending on whether
4386 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4388 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
4390 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4394 * no node mask - aka implicit memory numa policy. Do not bother with
4395 * the synchronization - read_mems_allowed_begin - because we do not
4396 * have to be precise here.
4399 nodemask
= &cpuset_current_mems_allowed
;
4401 return !node_isset(nid
, *nodemask
);
4404 #define K(x) ((x) << (PAGE_SHIFT-10))
4406 static void show_migration_types(unsigned char type
)
4408 static const char types
[MIGRATE_TYPES
] = {
4409 [MIGRATE_UNMOVABLE
] = 'U',
4410 [MIGRATE_MOVABLE
] = 'M',
4411 [MIGRATE_RECLAIMABLE
] = 'E',
4412 [MIGRATE_HIGHATOMIC
] = 'H',
4414 [MIGRATE_CMA
] = 'C',
4416 #ifdef CONFIG_MEMORY_ISOLATION
4417 [MIGRATE_ISOLATE
] = 'I',
4420 char tmp
[MIGRATE_TYPES
+ 1];
4424 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4425 if (type
& (1 << i
))
4430 printk(KERN_CONT
"(%s) ", tmp
);
4434 * Show free area list (used inside shift_scroll-lock stuff)
4435 * We also calculate the percentage fragmentation. We do this by counting the
4436 * memory on each free list with the exception of the first item on the list.
4439 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4442 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
4444 unsigned long free_pcp
= 0;
4449 for_each_populated_zone(zone
) {
4450 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4453 for_each_online_cpu(cpu
)
4454 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4457 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4458 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4459 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4460 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4461 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4462 " free:%lu free_pcp:%lu free_cma:%lu\n",
4463 global_node_page_state(NR_ACTIVE_ANON
),
4464 global_node_page_state(NR_INACTIVE_ANON
),
4465 global_node_page_state(NR_ISOLATED_ANON
),
4466 global_node_page_state(NR_ACTIVE_FILE
),
4467 global_node_page_state(NR_INACTIVE_FILE
),
4468 global_node_page_state(NR_ISOLATED_FILE
),
4469 global_node_page_state(NR_UNEVICTABLE
),
4470 global_node_page_state(NR_FILE_DIRTY
),
4471 global_node_page_state(NR_WRITEBACK
),
4472 global_node_page_state(NR_UNSTABLE_NFS
),
4473 global_page_state(NR_SLAB_RECLAIMABLE
),
4474 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4475 global_node_page_state(NR_FILE_MAPPED
),
4476 global_node_page_state(NR_SHMEM
),
4477 global_page_state(NR_PAGETABLE
),
4478 global_page_state(NR_BOUNCE
),
4479 global_page_state(NR_FREE_PAGES
),
4481 global_page_state(NR_FREE_CMA_PAGES
));
4483 for_each_online_pgdat(pgdat
) {
4484 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
4488 " active_anon:%lukB"
4489 " inactive_anon:%lukB"
4490 " active_file:%lukB"
4491 " inactive_file:%lukB"
4492 " unevictable:%lukB"
4493 " isolated(anon):%lukB"
4494 " isolated(file):%lukB"
4499 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4501 " shmem_pmdmapped: %lukB"
4504 " writeback_tmp:%lukB"
4506 " pages_scanned:%lu"
4507 " all_unreclaimable? %s"
4510 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4511 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4512 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4513 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4514 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4515 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4516 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4517 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4518 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4519 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4520 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4521 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4522 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4524 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4526 K(node_page_state(pgdat
, NR_SHMEM
)),
4527 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4528 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4529 node_page_state(pgdat
, NR_PAGES_SCANNED
),
4530 !pgdat_reclaimable(pgdat
) ? "yes" : "no");
4533 for_each_populated_zone(zone
) {
4536 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4540 for_each_online_cpu(cpu
)
4541 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4550 " active_anon:%lukB"
4551 " inactive_anon:%lukB"
4552 " active_file:%lukB"
4553 " inactive_file:%lukB"
4554 " unevictable:%lukB"
4555 " writepending:%lukB"
4559 " slab_reclaimable:%lukB"
4560 " slab_unreclaimable:%lukB"
4561 " kernel_stack:%lukB"
4569 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4570 K(min_wmark_pages(zone
)),
4571 K(low_wmark_pages(zone
)),
4572 K(high_wmark_pages(zone
)),
4573 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4574 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4575 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4576 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4577 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4578 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4579 K(zone
->present_pages
),
4580 K(zone
->managed_pages
),
4581 K(zone_page_state(zone
, NR_MLOCK
)),
4582 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
4583 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
4584 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4585 K(zone_page_state(zone
, NR_PAGETABLE
)),
4586 K(zone_page_state(zone
, NR_BOUNCE
)),
4588 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4589 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4590 printk("lowmem_reserve[]:");
4591 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4592 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
4593 printk(KERN_CONT
"\n");
4596 for_each_populated_zone(zone
) {
4598 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4599 unsigned char types
[MAX_ORDER
];
4601 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4604 printk(KERN_CONT
"%s: ", zone
->name
);
4606 spin_lock_irqsave(&zone
->lock
, flags
);
4607 for (order
= 0; order
< MAX_ORDER
; order
++) {
4608 struct free_area
*area
= &zone
->free_area
[order
];
4611 nr
[order
] = area
->nr_free
;
4612 total
+= nr
[order
] << order
;
4615 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4616 if (!list_empty(&area
->free_list
[type
]))
4617 types
[order
] |= 1 << type
;
4620 spin_unlock_irqrestore(&zone
->lock
, flags
);
4621 for (order
= 0; order
< MAX_ORDER
; order
++) {
4622 printk(KERN_CONT
"%lu*%lukB ",
4623 nr
[order
], K(1UL) << order
);
4625 show_migration_types(types
[order
]);
4627 printk(KERN_CONT
"= %lukB\n", K(total
));
4630 hugetlb_show_meminfo();
4632 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4634 show_swap_cache_info();
4637 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4639 zoneref
->zone
= zone
;
4640 zoneref
->zone_idx
= zone_idx(zone
);
4644 * Builds allocation fallback zone lists.
4646 * Add all populated zones of a node to the zonelist.
4648 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4652 enum zone_type zone_type
= MAX_NR_ZONES
;
4656 zone
= pgdat
->node_zones
+ zone_type
;
4657 if (managed_zone(zone
)) {
4658 zoneref_set_zone(zone
,
4659 &zonelist
->_zonerefs
[nr_zones
++]);
4660 check_highest_zone(zone_type
);
4662 } while (zone_type
);
4670 * 0 = automatic detection of better ordering.
4671 * 1 = order by ([node] distance, -zonetype)
4672 * 2 = order by (-zonetype, [node] distance)
4674 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4675 * the same zonelist. So only NUMA can configure this param.
4677 #define ZONELIST_ORDER_DEFAULT 0
4678 #define ZONELIST_ORDER_NODE 1
4679 #define ZONELIST_ORDER_ZONE 2
4681 /* zonelist order in the kernel.
4682 * set_zonelist_order() will set this to NODE or ZONE.
4684 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4685 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4689 /* The value user specified ....changed by config */
4690 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4691 /* string for sysctl */
4692 #define NUMA_ZONELIST_ORDER_LEN 16
4693 char numa_zonelist_order
[16] = "default";
4696 * interface for configure zonelist ordering.
4697 * command line option "numa_zonelist_order"
4698 * = "[dD]efault - default, automatic configuration.
4699 * = "[nN]ode - order by node locality, then by zone within node
4700 * = "[zZ]one - order by zone, then by locality within zone
4703 static int __parse_numa_zonelist_order(char *s
)
4705 if (*s
== 'd' || *s
== 'D') {
4706 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4707 } else if (*s
== 'n' || *s
== 'N') {
4708 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4709 } else if (*s
== 'z' || *s
== 'Z') {
4710 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4712 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4718 static __init
int setup_numa_zonelist_order(char *s
)
4725 ret
= __parse_numa_zonelist_order(s
);
4727 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4731 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4734 * sysctl handler for numa_zonelist_order
4736 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4737 void __user
*buffer
, size_t *length
,
4740 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4742 static DEFINE_MUTEX(zl_order_mutex
);
4744 mutex_lock(&zl_order_mutex
);
4746 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4750 strcpy(saved_string
, (char *)table
->data
);
4752 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4756 int oldval
= user_zonelist_order
;
4758 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4761 * bogus value. restore saved string
4763 strncpy((char *)table
->data
, saved_string
,
4764 NUMA_ZONELIST_ORDER_LEN
);
4765 user_zonelist_order
= oldval
;
4766 } else if (oldval
!= user_zonelist_order
) {
4767 mutex_lock(&zonelists_mutex
);
4768 build_all_zonelists(NULL
, NULL
);
4769 mutex_unlock(&zonelists_mutex
);
4773 mutex_unlock(&zl_order_mutex
);
4778 #define MAX_NODE_LOAD (nr_online_nodes)
4779 static int node_load
[MAX_NUMNODES
];
4782 * find_next_best_node - find the next node that should appear in a given node's fallback list
4783 * @node: node whose fallback list we're appending
4784 * @used_node_mask: nodemask_t of already used nodes
4786 * We use a number of factors to determine which is the next node that should
4787 * appear on a given node's fallback list. The node should not have appeared
4788 * already in @node's fallback list, and it should be the next closest node
4789 * according to the distance array (which contains arbitrary distance values
4790 * from each node to each node in the system), and should also prefer nodes
4791 * with no CPUs, since presumably they'll have very little allocation pressure
4792 * on them otherwise.
4793 * It returns -1 if no node is found.
4795 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4798 int min_val
= INT_MAX
;
4799 int best_node
= NUMA_NO_NODE
;
4800 const struct cpumask
*tmp
= cpumask_of_node(0);
4802 /* Use the local node if we haven't already */
4803 if (!node_isset(node
, *used_node_mask
)) {
4804 node_set(node
, *used_node_mask
);
4808 for_each_node_state(n
, N_MEMORY
) {
4810 /* Don't want a node to appear more than once */
4811 if (node_isset(n
, *used_node_mask
))
4814 /* Use the distance array to find the distance */
4815 val
= node_distance(node
, n
);
4817 /* Penalize nodes under us ("prefer the next node") */
4820 /* Give preference to headless and unused nodes */
4821 tmp
= cpumask_of_node(n
);
4822 if (!cpumask_empty(tmp
))
4823 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4825 /* Slight preference for less loaded node */
4826 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4827 val
+= node_load
[n
];
4829 if (val
< min_val
) {
4836 node_set(best_node
, *used_node_mask
);
4843 * Build zonelists ordered by node and zones within node.
4844 * This results in maximum locality--normal zone overflows into local
4845 * DMA zone, if any--but risks exhausting DMA zone.
4847 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4850 struct zonelist
*zonelist
;
4852 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
4853 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4855 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4856 zonelist
->_zonerefs
[j
].zone
= NULL
;
4857 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4861 * Build gfp_thisnode zonelists
4863 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4866 struct zonelist
*zonelist
;
4868 zonelist
= &pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
];
4869 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4870 zonelist
->_zonerefs
[j
].zone
= NULL
;
4871 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4875 * Build zonelists ordered by zone and nodes within zones.
4876 * This results in conserving DMA zone[s] until all Normal memory is
4877 * exhausted, but results in overflowing to remote node while memory
4878 * may still exist in local DMA zone.
4880 static int node_order
[MAX_NUMNODES
];
4882 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4885 int zone_type
; /* needs to be signed */
4887 struct zonelist
*zonelist
;
4889 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
4891 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4892 for (j
= 0; j
< nr_nodes
; j
++) {
4893 node
= node_order
[j
];
4894 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4895 if (managed_zone(z
)) {
4897 &zonelist
->_zonerefs
[pos
++]);
4898 check_highest_zone(zone_type
);
4902 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4903 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4906 #if defined(CONFIG_64BIT)
4908 * Devices that require DMA32/DMA are relatively rare and do not justify a
4909 * penalty to every machine in case the specialised case applies. Default
4910 * to Node-ordering on 64-bit NUMA machines
4912 static int default_zonelist_order(void)
4914 return ZONELIST_ORDER_NODE
;
4918 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4919 * by the kernel. If processes running on node 0 deplete the low memory zone
4920 * then reclaim will occur more frequency increasing stalls and potentially
4921 * be easier to OOM if a large percentage of the zone is under writeback or
4922 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4923 * Hence, default to zone ordering on 32-bit.
4925 static int default_zonelist_order(void)
4927 return ZONELIST_ORDER_ZONE
;
4929 #endif /* CONFIG_64BIT */
4931 static void set_zonelist_order(void)
4933 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4934 current_zonelist_order
= default_zonelist_order();
4936 current_zonelist_order
= user_zonelist_order
;
4939 static void build_zonelists(pg_data_t
*pgdat
)
4942 nodemask_t used_mask
;
4943 int local_node
, prev_node
;
4944 struct zonelist
*zonelist
;
4945 unsigned int order
= current_zonelist_order
;
4947 /* initialize zonelists */
4948 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4949 zonelist
= pgdat
->node_zonelists
+ i
;
4950 zonelist
->_zonerefs
[0].zone
= NULL
;
4951 zonelist
->_zonerefs
[0].zone_idx
= 0;
4954 /* NUMA-aware ordering of nodes */
4955 local_node
= pgdat
->node_id
;
4956 load
= nr_online_nodes
;
4957 prev_node
= local_node
;
4958 nodes_clear(used_mask
);
4960 memset(node_order
, 0, sizeof(node_order
));
4963 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4965 * We don't want to pressure a particular node.
4966 * So adding penalty to the first node in same
4967 * distance group to make it round-robin.
4969 if (node_distance(local_node
, node
) !=
4970 node_distance(local_node
, prev_node
))
4971 node_load
[node
] = load
;
4975 if (order
== ZONELIST_ORDER_NODE
)
4976 build_zonelists_in_node_order(pgdat
, node
);
4978 node_order
[i
++] = node
; /* remember order */
4981 if (order
== ZONELIST_ORDER_ZONE
) {
4982 /* calculate node order -- i.e., DMA last! */
4983 build_zonelists_in_zone_order(pgdat
, i
);
4986 build_thisnode_zonelists(pgdat
);
4989 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4991 * Return node id of node used for "local" allocations.
4992 * I.e., first node id of first zone in arg node's generic zonelist.
4993 * Used for initializing percpu 'numa_mem', which is used primarily
4994 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4996 int local_memory_node(int node
)
5000 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5001 gfp_zone(GFP_KERNEL
),
5003 return z
->zone
->node
;
5007 static void setup_min_unmapped_ratio(void);
5008 static void setup_min_slab_ratio(void);
5009 #else /* CONFIG_NUMA */
5011 static void set_zonelist_order(void)
5013 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
5016 static void build_zonelists(pg_data_t
*pgdat
)
5018 int node
, local_node
;
5020 struct zonelist
*zonelist
;
5022 local_node
= pgdat
->node_id
;
5024 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
5025 j
= build_zonelists_node(pgdat
, zonelist
, 0);
5028 * Now we build the zonelist so that it contains the zones
5029 * of all the other nodes.
5030 * We don't want to pressure a particular node, so when
5031 * building the zones for node N, we make sure that the
5032 * zones coming right after the local ones are those from
5033 * node N+1 (modulo N)
5035 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5036 if (!node_online(node
))
5038 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5040 for (node
= 0; node
< local_node
; node
++) {
5041 if (!node_online(node
))
5043 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5046 zonelist
->_zonerefs
[j
].zone
= NULL
;
5047 zonelist
->_zonerefs
[j
].zone_idx
= 0;
5050 #endif /* CONFIG_NUMA */
5053 * Boot pageset table. One per cpu which is going to be used for all
5054 * zones and all nodes. The parameters will be set in such a way
5055 * that an item put on a list will immediately be handed over to
5056 * the buddy list. This is safe since pageset manipulation is done
5057 * with interrupts disabled.
5059 * The boot_pagesets must be kept even after bootup is complete for
5060 * unused processors and/or zones. They do play a role for bootstrapping
5061 * hotplugged processors.
5063 * zoneinfo_show() and maybe other functions do
5064 * not check if the processor is online before following the pageset pointer.
5065 * Other parts of the kernel may not check if the zone is available.
5067 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5068 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5069 static void setup_zone_pageset(struct zone
*zone
);
5072 * Global mutex to protect against size modification of zonelists
5073 * as well as to serialize pageset setup for the new populated zone.
5075 DEFINE_MUTEX(zonelists_mutex
);
5077 /* return values int ....just for stop_machine() */
5078 static int __build_all_zonelists(void *data
)
5082 pg_data_t
*self
= data
;
5085 memset(node_load
, 0, sizeof(node_load
));
5088 if (self
&& !node_online(self
->node_id
)) {
5089 build_zonelists(self
);
5092 for_each_online_node(nid
) {
5093 pg_data_t
*pgdat
= NODE_DATA(nid
);
5095 build_zonelists(pgdat
);
5099 * Initialize the boot_pagesets that are going to be used
5100 * for bootstrapping processors. The real pagesets for
5101 * each zone will be allocated later when the per cpu
5102 * allocator is available.
5104 * boot_pagesets are used also for bootstrapping offline
5105 * cpus if the system is already booted because the pagesets
5106 * are needed to initialize allocators on a specific cpu too.
5107 * F.e. the percpu allocator needs the page allocator which
5108 * needs the percpu allocator in order to allocate its pagesets
5109 * (a chicken-egg dilemma).
5111 for_each_possible_cpu(cpu
) {
5112 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5114 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5116 * We now know the "local memory node" for each node--
5117 * i.e., the node of the first zone in the generic zonelist.
5118 * Set up numa_mem percpu variable for on-line cpus. During
5119 * boot, only the boot cpu should be on-line; we'll init the
5120 * secondary cpus' numa_mem as they come on-line. During
5121 * node/memory hotplug, we'll fixup all on-line cpus.
5123 if (cpu_online(cpu
))
5124 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5131 static noinline
void __init
5132 build_all_zonelists_init(void)
5134 __build_all_zonelists(NULL
);
5135 mminit_verify_zonelist();
5136 cpuset_init_current_mems_allowed();
5140 * Called with zonelists_mutex held always
5141 * unless system_state == SYSTEM_BOOTING.
5143 * __ref due to (1) call of __meminit annotated setup_zone_pageset
5144 * [we're only called with non-NULL zone through __meminit paths] and
5145 * (2) call of __init annotated helper build_all_zonelists_init
5146 * [protected by SYSTEM_BOOTING].
5148 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
5150 set_zonelist_order();
5152 if (system_state
== SYSTEM_BOOTING
) {
5153 build_all_zonelists_init();
5155 #ifdef CONFIG_MEMORY_HOTPLUG
5157 setup_zone_pageset(zone
);
5159 /* we have to stop all cpus to guarantee there is no user
5161 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
5162 /* cpuset refresh routine should be here */
5164 vm_total_pages
= nr_free_pagecache_pages();
5166 * Disable grouping by mobility if the number of pages in the
5167 * system is too low to allow the mechanism to work. It would be
5168 * more accurate, but expensive to check per-zone. This check is
5169 * made on memory-hotadd so a system can start with mobility
5170 * disabled and enable it later
5172 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5173 page_group_by_mobility_disabled
= 1;
5175 page_group_by_mobility_disabled
= 0;
5177 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5179 zonelist_order_name
[current_zonelist_order
],
5180 page_group_by_mobility_disabled
? "off" : "on",
5183 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5188 * Initially all pages are reserved - free ones are freed
5189 * up by free_all_bootmem() once the early boot process is
5190 * done. Non-atomic initialization, single-pass.
5192 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5193 unsigned long start_pfn
, enum memmap_context context
)
5195 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5196 unsigned long end_pfn
= start_pfn
+ size
;
5197 pg_data_t
*pgdat
= NODE_DATA(nid
);
5199 unsigned long nr_initialised
= 0;
5200 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5201 struct memblock_region
*r
= NULL
, *tmp
;
5204 if (highest_memmap_pfn
< end_pfn
- 1)
5205 highest_memmap_pfn
= end_pfn
- 1;
5208 * Honor reservation requested by the driver for this ZONE_DEVICE
5211 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5212 start_pfn
+= altmap
->reserve
;
5214 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5216 * There can be holes in boot-time mem_map[]s handed to this
5217 * function. They do not exist on hotplugged memory.
5219 if (context
!= MEMMAP_EARLY
)
5222 if (!early_pfn_valid(pfn
)) {
5223 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5225 * Skip to the pfn preceding the next valid one (or
5226 * end_pfn), such that we hit a valid pfn (or end_pfn)
5227 * on our next iteration of the loop.
5229 pfn
= memblock_next_valid_pfn(pfn
, end_pfn
) - 1;
5233 if (!early_pfn_in_nid(pfn
, nid
))
5235 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5238 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5240 * Check given memblock attribute by firmware which can affect
5241 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5242 * mirrored, it's an overlapped memmap init. skip it.
5244 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5245 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5246 for_each_memblock(memory
, tmp
)
5247 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5251 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5252 memblock_is_mirror(r
)) {
5253 /* already initialized as NORMAL */
5254 pfn
= memblock_region_memory_end_pfn(r
);
5262 * Mark the block movable so that blocks are reserved for
5263 * movable at startup. This will force kernel allocations
5264 * to reserve their blocks rather than leaking throughout
5265 * the address space during boot when many long-lived
5266 * kernel allocations are made.
5268 * bitmap is created for zone's valid pfn range. but memmap
5269 * can be created for invalid pages (for alignment)
5270 * check here not to call set_pageblock_migratetype() against
5273 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5274 struct page
*page
= pfn_to_page(pfn
);
5276 __init_single_page(page
, pfn
, zone
, nid
);
5277 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5279 __init_single_pfn(pfn
, zone
, nid
);
5284 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5286 unsigned int order
, t
;
5287 for_each_migratetype_order(order
, t
) {
5288 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5289 zone
->free_area
[order
].nr_free
= 0;
5293 #ifndef __HAVE_ARCH_MEMMAP_INIT
5294 #define memmap_init(size, nid, zone, start_pfn) \
5295 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5298 static int zone_batchsize(struct zone
*zone
)
5304 * The per-cpu-pages pools are set to around 1000th of the
5305 * size of the zone. But no more than 1/2 of a meg.
5307 * OK, so we don't know how big the cache is. So guess.
5309 batch
= zone
->managed_pages
/ 1024;
5310 if (batch
* PAGE_SIZE
> 512 * 1024)
5311 batch
= (512 * 1024) / PAGE_SIZE
;
5312 batch
/= 4; /* We effectively *= 4 below */
5317 * Clamp the batch to a 2^n - 1 value. Having a power
5318 * of 2 value was found to be more likely to have
5319 * suboptimal cache aliasing properties in some cases.
5321 * For example if 2 tasks are alternately allocating
5322 * batches of pages, one task can end up with a lot
5323 * of pages of one half of the possible page colors
5324 * and the other with pages of the other colors.
5326 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5331 /* The deferral and batching of frees should be suppressed under NOMMU
5334 * The problem is that NOMMU needs to be able to allocate large chunks
5335 * of contiguous memory as there's no hardware page translation to
5336 * assemble apparent contiguous memory from discontiguous pages.
5338 * Queueing large contiguous runs of pages for batching, however,
5339 * causes the pages to actually be freed in smaller chunks. As there
5340 * can be a significant delay between the individual batches being
5341 * recycled, this leads to the once large chunks of space being
5342 * fragmented and becoming unavailable for high-order allocations.
5349 * pcp->high and pcp->batch values are related and dependent on one another:
5350 * ->batch must never be higher then ->high.
5351 * The following function updates them in a safe manner without read side
5354 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5355 * those fields changing asynchronously (acording the the above rule).
5357 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5358 * outside of boot time (or some other assurance that no concurrent updaters
5361 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5362 unsigned long batch
)
5364 /* start with a fail safe value for batch */
5368 /* Update high, then batch, in order */
5375 /* a companion to pageset_set_high() */
5376 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5378 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5381 static void pageset_init(struct per_cpu_pageset
*p
)
5383 struct per_cpu_pages
*pcp
;
5386 memset(p
, 0, sizeof(*p
));
5390 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5391 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5394 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5397 pageset_set_batch(p
, batch
);
5401 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5402 * to the value high for the pageset p.
5404 static void pageset_set_high(struct per_cpu_pageset
*p
,
5407 unsigned long batch
= max(1UL, high
/ 4);
5408 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5409 batch
= PAGE_SHIFT
* 8;
5411 pageset_update(&p
->pcp
, high
, batch
);
5414 static void pageset_set_high_and_batch(struct zone
*zone
,
5415 struct per_cpu_pageset
*pcp
)
5417 if (percpu_pagelist_fraction
)
5418 pageset_set_high(pcp
,
5419 (zone
->managed_pages
/
5420 percpu_pagelist_fraction
));
5422 pageset_set_batch(pcp
, zone_batchsize(zone
));
5425 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5427 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5430 pageset_set_high_and_batch(zone
, pcp
);
5433 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5436 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5437 for_each_possible_cpu(cpu
)
5438 zone_pageset_init(zone
, cpu
);
5442 * Allocate per cpu pagesets and initialize them.
5443 * Before this call only boot pagesets were available.
5445 void __init
setup_per_cpu_pageset(void)
5447 struct pglist_data
*pgdat
;
5450 for_each_populated_zone(zone
)
5451 setup_zone_pageset(zone
);
5453 for_each_online_pgdat(pgdat
)
5454 pgdat
->per_cpu_nodestats
=
5455 alloc_percpu(struct per_cpu_nodestat
);
5458 static __meminit
void zone_pcp_init(struct zone
*zone
)
5461 * per cpu subsystem is not up at this point. The following code
5462 * relies on the ability of the linker to provide the
5463 * offset of a (static) per cpu variable into the per cpu area.
5465 zone
->pageset
= &boot_pageset
;
5467 if (populated_zone(zone
))
5468 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5469 zone
->name
, zone
->present_pages
,
5470 zone_batchsize(zone
));
5473 int __meminit
init_currently_empty_zone(struct zone
*zone
,
5474 unsigned long zone_start_pfn
,
5477 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5479 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5481 zone
->zone_start_pfn
= zone_start_pfn
;
5483 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5484 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5486 (unsigned long)zone_idx(zone
),
5487 zone_start_pfn
, (zone_start_pfn
+ size
));
5489 zone_init_free_lists(zone
);
5490 zone
->initialized
= 1;
5495 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5496 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5499 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5501 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5502 struct mminit_pfnnid_cache
*state
)
5504 unsigned long start_pfn
, end_pfn
;
5507 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5508 return state
->last_nid
;
5510 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5512 state
->last_start
= start_pfn
;
5513 state
->last_end
= end_pfn
;
5514 state
->last_nid
= nid
;
5519 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5522 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5523 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5524 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5526 * If an architecture guarantees that all ranges registered contain no holes
5527 * and may be freed, this this function may be used instead of calling
5528 * memblock_free_early_nid() manually.
5530 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5532 unsigned long start_pfn
, end_pfn
;
5535 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5536 start_pfn
= min(start_pfn
, max_low_pfn
);
5537 end_pfn
= min(end_pfn
, max_low_pfn
);
5539 if (start_pfn
< end_pfn
)
5540 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5541 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5547 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5548 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5550 * If an architecture guarantees that all ranges registered contain no holes and may
5551 * be freed, this function may be used instead of calling memory_present() manually.
5553 void __init
sparse_memory_present_with_active_regions(int nid
)
5555 unsigned long start_pfn
, end_pfn
;
5558 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5559 memory_present(this_nid
, start_pfn
, end_pfn
);
5563 * get_pfn_range_for_nid - Return the start and end page frames for a node
5564 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5565 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5566 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5568 * It returns the start and end page frame of a node based on information
5569 * provided by memblock_set_node(). If called for a node
5570 * with no available memory, a warning is printed and the start and end
5573 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5574 unsigned long *start_pfn
, unsigned long *end_pfn
)
5576 unsigned long this_start_pfn
, this_end_pfn
;
5582 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5583 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5584 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5587 if (*start_pfn
== -1UL)
5592 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5593 * assumption is made that zones within a node are ordered in monotonic
5594 * increasing memory addresses so that the "highest" populated zone is used
5596 static void __init
find_usable_zone_for_movable(void)
5599 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5600 if (zone_index
== ZONE_MOVABLE
)
5603 if (arch_zone_highest_possible_pfn
[zone_index
] >
5604 arch_zone_lowest_possible_pfn
[zone_index
])
5608 VM_BUG_ON(zone_index
== -1);
5609 movable_zone
= zone_index
;
5613 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5614 * because it is sized independent of architecture. Unlike the other zones,
5615 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5616 * in each node depending on the size of each node and how evenly kernelcore
5617 * is distributed. This helper function adjusts the zone ranges
5618 * provided by the architecture for a given node by using the end of the
5619 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5620 * zones within a node are in order of monotonic increases memory addresses
5622 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5623 unsigned long zone_type
,
5624 unsigned long node_start_pfn
,
5625 unsigned long node_end_pfn
,
5626 unsigned long *zone_start_pfn
,
5627 unsigned long *zone_end_pfn
)
5629 /* Only adjust if ZONE_MOVABLE is on this node */
5630 if (zone_movable_pfn
[nid
]) {
5631 /* Size ZONE_MOVABLE */
5632 if (zone_type
== ZONE_MOVABLE
) {
5633 *zone_start_pfn
= zone_movable_pfn
[nid
];
5634 *zone_end_pfn
= min(node_end_pfn
,
5635 arch_zone_highest_possible_pfn
[movable_zone
]);
5637 /* Adjust for ZONE_MOVABLE starting within this range */
5638 } else if (!mirrored_kernelcore
&&
5639 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
5640 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5641 *zone_end_pfn
= zone_movable_pfn
[nid
];
5643 /* Check if this whole range is within ZONE_MOVABLE */
5644 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5645 *zone_start_pfn
= *zone_end_pfn
;
5650 * Return the number of pages a zone spans in a node, including holes
5651 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5653 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5654 unsigned long zone_type
,
5655 unsigned long node_start_pfn
,
5656 unsigned long node_end_pfn
,
5657 unsigned long *zone_start_pfn
,
5658 unsigned long *zone_end_pfn
,
5659 unsigned long *ignored
)
5661 /* When hotadd a new node from cpu_up(), the node should be empty */
5662 if (!node_start_pfn
&& !node_end_pfn
)
5665 /* Get the start and end of the zone */
5666 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5667 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5668 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5669 node_start_pfn
, node_end_pfn
,
5670 zone_start_pfn
, zone_end_pfn
);
5672 /* Check that this node has pages within the zone's required range */
5673 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5676 /* Move the zone boundaries inside the node if necessary */
5677 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5678 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5680 /* Return the spanned pages */
5681 return *zone_end_pfn
- *zone_start_pfn
;
5685 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5686 * then all holes in the requested range will be accounted for.
5688 unsigned long __meminit
__absent_pages_in_range(int nid
,
5689 unsigned long range_start_pfn
,
5690 unsigned long range_end_pfn
)
5692 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5693 unsigned long start_pfn
, end_pfn
;
5696 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5697 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5698 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5699 nr_absent
-= end_pfn
- start_pfn
;
5705 * absent_pages_in_range - Return number of page frames in holes within a range
5706 * @start_pfn: The start PFN to start searching for holes
5707 * @end_pfn: The end PFN to stop searching for holes
5709 * It returns the number of pages frames in memory holes within a range.
5711 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5712 unsigned long end_pfn
)
5714 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5717 /* Return the number of page frames in holes in a zone on a node */
5718 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5719 unsigned long zone_type
,
5720 unsigned long node_start_pfn
,
5721 unsigned long node_end_pfn
,
5722 unsigned long *ignored
)
5724 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5725 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5726 unsigned long zone_start_pfn
, zone_end_pfn
;
5727 unsigned long nr_absent
;
5729 /* When hotadd a new node from cpu_up(), the node should be empty */
5730 if (!node_start_pfn
&& !node_end_pfn
)
5733 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5734 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5736 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5737 node_start_pfn
, node_end_pfn
,
5738 &zone_start_pfn
, &zone_end_pfn
);
5739 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5742 * ZONE_MOVABLE handling.
5743 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5746 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
5747 unsigned long start_pfn
, end_pfn
;
5748 struct memblock_region
*r
;
5750 for_each_memblock(memory
, r
) {
5751 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5752 zone_start_pfn
, zone_end_pfn
);
5753 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5754 zone_start_pfn
, zone_end_pfn
);
5756 if (zone_type
== ZONE_MOVABLE
&&
5757 memblock_is_mirror(r
))
5758 nr_absent
+= end_pfn
- start_pfn
;
5760 if (zone_type
== ZONE_NORMAL
&&
5761 !memblock_is_mirror(r
))
5762 nr_absent
+= end_pfn
- start_pfn
;
5769 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5770 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5771 unsigned long zone_type
,
5772 unsigned long node_start_pfn
,
5773 unsigned long node_end_pfn
,
5774 unsigned long *zone_start_pfn
,
5775 unsigned long *zone_end_pfn
,
5776 unsigned long *zones_size
)
5780 *zone_start_pfn
= node_start_pfn
;
5781 for (zone
= 0; zone
< zone_type
; zone
++)
5782 *zone_start_pfn
+= zones_size
[zone
];
5784 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5786 return zones_size
[zone_type
];
5789 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5790 unsigned long zone_type
,
5791 unsigned long node_start_pfn
,
5792 unsigned long node_end_pfn
,
5793 unsigned long *zholes_size
)
5798 return zholes_size
[zone_type
];
5801 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5803 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5804 unsigned long node_start_pfn
,
5805 unsigned long node_end_pfn
,
5806 unsigned long *zones_size
,
5807 unsigned long *zholes_size
)
5809 unsigned long realtotalpages
= 0, totalpages
= 0;
5812 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5813 struct zone
*zone
= pgdat
->node_zones
+ i
;
5814 unsigned long zone_start_pfn
, zone_end_pfn
;
5815 unsigned long size
, real_size
;
5817 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5823 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5824 node_start_pfn
, node_end_pfn
,
5827 zone
->zone_start_pfn
= zone_start_pfn
;
5829 zone
->zone_start_pfn
= 0;
5830 zone
->spanned_pages
= size
;
5831 zone
->present_pages
= real_size
;
5834 realtotalpages
+= real_size
;
5837 pgdat
->node_spanned_pages
= totalpages
;
5838 pgdat
->node_present_pages
= realtotalpages
;
5839 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5843 #ifndef CONFIG_SPARSEMEM
5845 * Calculate the size of the zone->blockflags rounded to an unsigned long
5846 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5847 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5848 * round what is now in bits to nearest long in bits, then return it in
5851 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5853 unsigned long usemapsize
;
5855 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5856 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5857 usemapsize
= usemapsize
>> pageblock_order
;
5858 usemapsize
*= NR_PAGEBLOCK_BITS
;
5859 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5861 return usemapsize
/ 8;
5864 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5866 unsigned long zone_start_pfn
,
5867 unsigned long zonesize
)
5869 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5870 zone
->pageblock_flags
= NULL
;
5872 zone
->pageblock_flags
=
5873 memblock_virt_alloc_node_nopanic(usemapsize
,
5877 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5878 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5879 #endif /* CONFIG_SPARSEMEM */
5881 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5883 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5884 void __paginginit
set_pageblock_order(void)
5888 /* Check that pageblock_nr_pages has not already been setup */
5889 if (pageblock_order
)
5892 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5893 order
= HUGETLB_PAGE_ORDER
;
5895 order
= MAX_ORDER
- 1;
5898 * Assume the largest contiguous order of interest is a huge page.
5899 * This value may be variable depending on boot parameters on IA64 and
5902 pageblock_order
= order
;
5904 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5907 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5908 * is unused as pageblock_order is set at compile-time. See
5909 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5912 void __paginginit
set_pageblock_order(void)
5916 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5918 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5919 unsigned long present_pages
)
5921 unsigned long pages
= spanned_pages
;
5924 * Provide a more accurate estimation if there are holes within
5925 * the zone and SPARSEMEM is in use. If there are holes within the
5926 * zone, each populated memory region may cost us one or two extra
5927 * memmap pages due to alignment because memmap pages for each
5928 * populated regions may not be naturally aligned on page boundary.
5929 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5931 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5932 IS_ENABLED(CONFIG_SPARSEMEM
))
5933 pages
= present_pages
;
5935 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5939 * Set up the zone data structures:
5940 * - mark all pages reserved
5941 * - mark all memory queues empty
5942 * - clear the memory bitmaps
5944 * NOTE: pgdat should get zeroed by caller.
5946 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5949 int nid
= pgdat
->node_id
;
5952 pgdat_resize_init(pgdat
);
5953 #ifdef CONFIG_NUMA_BALANCING
5954 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5955 pgdat
->numabalancing_migrate_nr_pages
= 0;
5956 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5958 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5959 spin_lock_init(&pgdat
->split_queue_lock
);
5960 INIT_LIST_HEAD(&pgdat
->split_queue
);
5961 pgdat
->split_queue_len
= 0;
5963 init_waitqueue_head(&pgdat
->kswapd_wait
);
5964 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5965 #ifdef CONFIG_COMPACTION
5966 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5968 pgdat_page_ext_init(pgdat
);
5969 spin_lock_init(&pgdat
->lru_lock
);
5970 lruvec_init(node_lruvec(pgdat
));
5972 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5973 struct zone
*zone
= pgdat
->node_zones
+ j
;
5974 unsigned long size
, realsize
, freesize
, memmap_pages
;
5975 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5977 size
= zone
->spanned_pages
;
5978 realsize
= freesize
= zone
->present_pages
;
5981 * Adjust freesize so that it accounts for how much memory
5982 * is used by this zone for memmap. This affects the watermark
5983 * and per-cpu initialisations
5985 memmap_pages
= calc_memmap_size(size
, realsize
);
5986 if (!is_highmem_idx(j
)) {
5987 if (freesize
>= memmap_pages
) {
5988 freesize
-= memmap_pages
;
5991 " %s zone: %lu pages used for memmap\n",
5992 zone_names
[j
], memmap_pages
);
5994 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5995 zone_names
[j
], memmap_pages
, freesize
);
5998 /* Account for reserved pages */
5999 if (j
== 0 && freesize
> dma_reserve
) {
6000 freesize
-= dma_reserve
;
6001 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6002 zone_names
[0], dma_reserve
);
6005 if (!is_highmem_idx(j
))
6006 nr_kernel_pages
+= freesize
;
6007 /* Charge for highmem memmap if there are enough kernel pages */
6008 else if (nr_kernel_pages
> memmap_pages
* 2)
6009 nr_kernel_pages
-= memmap_pages
;
6010 nr_all_pages
+= freesize
;
6013 * Set an approximate value for lowmem here, it will be adjusted
6014 * when the bootmem allocator frees pages into the buddy system.
6015 * And all highmem pages will be managed by the buddy system.
6017 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
6021 zone
->name
= zone_names
[j
];
6022 zone
->zone_pgdat
= pgdat
;
6023 spin_lock_init(&zone
->lock
);
6024 zone_seqlock_init(zone
);
6025 zone_pcp_init(zone
);
6030 set_pageblock_order();
6031 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6032 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6034 memmap_init(size
, nid
, j
, zone_start_pfn
);
6038 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6040 unsigned long __maybe_unused start
= 0;
6041 unsigned long __maybe_unused offset
= 0;
6043 /* Skip empty nodes */
6044 if (!pgdat
->node_spanned_pages
)
6047 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6048 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6049 offset
= pgdat
->node_start_pfn
- start
;
6050 /* ia64 gets its own node_mem_map, before this, without bootmem */
6051 if (!pgdat
->node_mem_map
) {
6052 unsigned long size
, end
;
6056 * The zone's endpoints aren't required to be MAX_ORDER
6057 * aligned but the node_mem_map endpoints must be in order
6058 * for the buddy allocator to function correctly.
6060 end
= pgdat_end_pfn(pgdat
);
6061 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6062 size
= (end
- start
) * sizeof(struct page
);
6063 map
= alloc_remap(pgdat
->node_id
, size
);
6065 map
= memblock_virt_alloc_node_nopanic(size
,
6067 pgdat
->node_mem_map
= map
+ offset
;
6069 #ifndef CONFIG_NEED_MULTIPLE_NODES
6071 * With no DISCONTIG, the global mem_map is just set as node 0's
6073 if (pgdat
== NODE_DATA(0)) {
6074 mem_map
= NODE_DATA(0)->node_mem_map
;
6075 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6076 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6078 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6081 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6084 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6085 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6087 pg_data_t
*pgdat
= NODE_DATA(nid
);
6088 unsigned long start_pfn
= 0;
6089 unsigned long end_pfn
= 0;
6091 /* pg_data_t should be reset to zero when it's allocated */
6092 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6094 reset_deferred_meminit(pgdat
);
6095 pgdat
->node_id
= nid
;
6096 pgdat
->node_start_pfn
= node_start_pfn
;
6097 pgdat
->per_cpu_nodestats
= NULL
;
6098 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6099 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6100 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6101 (u64
)start_pfn
<< PAGE_SHIFT
,
6102 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6104 start_pfn
= node_start_pfn
;
6106 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6107 zones_size
, zholes_size
);
6109 alloc_node_mem_map(pgdat
);
6110 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6111 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6112 nid
, (unsigned long)pgdat
,
6113 (unsigned long)pgdat
->node_mem_map
);
6116 free_area_init_core(pgdat
);
6119 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6121 #if MAX_NUMNODES > 1
6123 * Figure out the number of possible node ids.
6125 void __init
setup_nr_node_ids(void)
6127 unsigned int highest
;
6129 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6130 nr_node_ids
= highest
+ 1;
6135 * node_map_pfn_alignment - determine the maximum internode alignment
6137 * This function should be called after node map is populated and sorted.
6138 * It calculates the maximum power of two alignment which can distinguish
6141 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6142 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6143 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6144 * shifted, 1GiB is enough and this function will indicate so.
6146 * This is used to test whether pfn -> nid mapping of the chosen memory
6147 * model has fine enough granularity to avoid incorrect mapping for the
6148 * populated node map.
6150 * Returns the determined alignment in pfn's. 0 if there is no alignment
6151 * requirement (single node).
6153 unsigned long __init
node_map_pfn_alignment(void)
6155 unsigned long accl_mask
= 0, last_end
= 0;
6156 unsigned long start
, end
, mask
;
6160 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6161 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6168 * Start with a mask granular enough to pin-point to the
6169 * start pfn and tick off bits one-by-one until it becomes
6170 * too coarse to separate the current node from the last.
6172 mask
= ~((1 << __ffs(start
)) - 1);
6173 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6176 /* accumulate all internode masks */
6180 /* convert mask to number of pages */
6181 return ~accl_mask
+ 1;
6184 /* Find the lowest pfn for a node */
6185 static unsigned long __init
find_min_pfn_for_node(int nid
)
6187 unsigned long min_pfn
= ULONG_MAX
;
6188 unsigned long start_pfn
;
6191 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6192 min_pfn
= min(min_pfn
, start_pfn
);
6194 if (min_pfn
== ULONG_MAX
) {
6195 pr_warn("Could not find start_pfn for node %d\n", nid
);
6203 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6205 * It returns the minimum PFN based on information provided via
6206 * memblock_set_node().
6208 unsigned long __init
find_min_pfn_with_active_regions(void)
6210 return find_min_pfn_for_node(MAX_NUMNODES
);
6214 * early_calculate_totalpages()
6215 * Sum pages in active regions for movable zone.
6216 * Populate N_MEMORY for calculating usable_nodes.
6218 static unsigned long __init
early_calculate_totalpages(void)
6220 unsigned long totalpages
= 0;
6221 unsigned long start_pfn
, end_pfn
;
6224 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6225 unsigned long pages
= end_pfn
- start_pfn
;
6227 totalpages
+= pages
;
6229 node_set_state(nid
, N_MEMORY
);
6235 * Find the PFN the Movable zone begins in each node. Kernel memory
6236 * is spread evenly between nodes as long as the nodes have enough
6237 * memory. When they don't, some nodes will have more kernelcore than
6240 static void __init
find_zone_movable_pfns_for_nodes(void)
6243 unsigned long usable_startpfn
;
6244 unsigned long kernelcore_node
, kernelcore_remaining
;
6245 /* save the state before borrow the nodemask */
6246 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6247 unsigned long totalpages
= early_calculate_totalpages();
6248 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6249 struct memblock_region
*r
;
6251 /* Need to find movable_zone earlier when movable_node is specified. */
6252 find_usable_zone_for_movable();
6255 * If movable_node is specified, ignore kernelcore and movablecore
6258 if (movable_node_is_enabled()) {
6259 for_each_memblock(memory
, r
) {
6260 if (!memblock_is_hotpluggable(r
))
6265 usable_startpfn
= PFN_DOWN(r
->base
);
6266 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6267 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6275 * If kernelcore=mirror is specified, ignore movablecore option
6277 if (mirrored_kernelcore
) {
6278 bool mem_below_4gb_not_mirrored
= false;
6280 for_each_memblock(memory
, r
) {
6281 if (memblock_is_mirror(r
))
6286 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6288 if (usable_startpfn
< 0x100000) {
6289 mem_below_4gb_not_mirrored
= true;
6293 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6294 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6298 if (mem_below_4gb_not_mirrored
)
6299 pr_warn("This configuration results in unmirrored kernel memory.");
6305 * If movablecore=nn[KMG] was specified, calculate what size of
6306 * kernelcore that corresponds so that memory usable for
6307 * any allocation type is evenly spread. If both kernelcore
6308 * and movablecore are specified, then the value of kernelcore
6309 * will be used for required_kernelcore if it's greater than
6310 * what movablecore would have allowed.
6312 if (required_movablecore
) {
6313 unsigned long corepages
;
6316 * Round-up so that ZONE_MOVABLE is at least as large as what
6317 * was requested by the user
6319 required_movablecore
=
6320 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6321 required_movablecore
= min(totalpages
, required_movablecore
);
6322 corepages
= totalpages
- required_movablecore
;
6324 required_kernelcore
= max(required_kernelcore
, corepages
);
6328 * If kernelcore was not specified or kernelcore size is larger
6329 * than totalpages, there is no ZONE_MOVABLE.
6331 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6334 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6335 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6338 /* Spread kernelcore memory as evenly as possible throughout nodes */
6339 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6340 for_each_node_state(nid
, N_MEMORY
) {
6341 unsigned long start_pfn
, end_pfn
;
6344 * Recalculate kernelcore_node if the division per node
6345 * now exceeds what is necessary to satisfy the requested
6346 * amount of memory for the kernel
6348 if (required_kernelcore
< kernelcore_node
)
6349 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6352 * As the map is walked, we track how much memory is usable
6353 * by the kernel using kernelcore_remaining. When it is
6354 * 0, the rest of the node is usable by ZONE_MOVABLE
6356 kernelcore_remaining
= kernelcore_node
;
6358 /* Go through each range of PFNs within this node */
6359 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6360 unsigned long size_pages
;
6362 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6363 if (start_pfn
>= end_pfn
)
6366 /* Account for what is only usable for kernelcore */
6367 if (start_pfn
< usable_startpfn
) {
6368 unsigned long kernel_pages
;
6369 kernel_pages
= min(end_pfn
, usable_startpfn
)
6372 kernelcore_remaining
-= min(kernel_pages
,
6373 kernelcore_remaining
);
6374 required_kernelcore
-= min(kernel_pages
,
6375 required_kernelcore
);
6377 /* Continue if range is now fully accounted */
6378 if (end_pfn
<= usable_startpfn
) {
6381 * Push zone_movable_pfn to the end so
6382 * that if we have to rebalance
6383 * kernelcore across nodes, we will
6384 * not double account here
6386 zone_movable_pfn
[nid
] = end_pfn
;
6389 start_pfn
= usable_startpfn
;
6393 * The usable PFN range for ZONE_MOVABLE is from
6394 * start_pfn->end_pfn. Calculate size_pages as the
6395 * number of pages used as kernelcore
6397 size_pages
= end_pfn
- start_pfn
;
6398 if (size_pages
> kernelcore_remaining
)
6399 size_pages
= kernelcore_remaining
;
6400 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6403 * Some kernelcore has been met, update counts and
6404 * break if the kernelcore for this node has been
6407 required_kernelcore
-= min(required_kernelcore
,
6409 kernelcore_remaining
-= size_pages
;
6410 if (!kernelcore_remaining
)
6416 * If there is still required_kernelcore, we do another pass with one
6417 * less node in the count. This will push zone_movable_pfn[nid] further
6418 * along on the nodes that still have memory until kernelcore is
6422 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6426 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6427 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6428 zone_movable_pfn
[nid
] =
6429 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6432 /* restore the node_state */
6433 node_states
[N_MEMORY
] = saved_node_state
;
6436 /* Any regular or high memory on that node ? */
6437 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6439 enum zone_type zone_type
;
6441 if (N_MEMORY
== N_NORMAL_MEMORY
)
6444 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6445 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6446 if (populated_zone(zone
)) {
6447 node_set_state(nid
, N_HIGH_MEMORY
);
6448 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6449 zone_type
<= ZONE_NORMAL
)
6450 node_set_state(nid
, N_NORMAL_MEMORY
);
6457 * free_area_init_nodes - Initialise all pg_data_t and zone data
6458 * @max_zone_pfn: an array of max PFNs for each zone
6460 * This will call free_area_init_node() for each active node in the system.
6461 * Using the page ranges provided by memblock_set_node(), the size of each
6462 * zone in each node and their holes is calculated. If the maximum PFN
6463 * between two adjacent zones match, it is assumed that the zone is empty.
6464 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6465 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6466 * starts where the previous one ended. For example, ZONE_DMA32 starts
6467 * at arch_max_dma_pfn.
6469 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6471 unsigned long start_pfn
, end_pfn
;
6474 /* Record where the zone boundaries are */
6475 memset(arch_zone_lowest_possible_pfn
, 0,
6476 sizeof(arch_zone_lowest_possible_pfn
));
6477 memset(arch_zone_highest_possible_pfn
, 0,
6478 sizeof(arch_zone_highest_possible_pfn
));
6480 start_pfn
= find_min_pfn_with_active_regions();
6482 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6483 if (i
== ZONE_MOVABLE
)
6486 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6487 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6488 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6490 start_pfn
= end_pfn
;
6493 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6494 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6495 find_zone_movable_pfns_for_nodes();
6497 /* Print out the zone ranges */
6498 pr_info("Zone ranges:\n");
6499 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6500 if (i
== ZONE_MOVABLE
)
6502 pr_info(" %-8s ", zone_names
[i
]);
6503 if (arch_zone_lowest_possible_pfn
[i
] ==
6504 arch_zone_highest_possible_pfn
[i
])
6507 pr_cont("[mem %#018Lx-%#018Lx]\n",
6508 (u64
)arch_zone_lowest_possible_pfn
[i
]
6510 ((u64
)arch_zone_highest_possible_pfn
[i
]
6511 << PAGE_SHIFT
) - 1);
6514 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6515 pr_info("Movable zone start for each node\n");
6516 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6517 if (zone_movable_pfn
[i
])
6518 pr_info(" Node %d: %#018Lx\n", i
,
6519 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6522 /* Print out the early node map */
6523 pr_info("Early memory node ranges\n");
6524 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6525 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6526 (u64
)start_pfn
<< PAGE_SHIFT
,
6527 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6529 /* Initialise every node */
6530 mminit_verify_pageflags_layout();
6531 setup_nr_node_ids();
6532 for_each_online_node(nid
) {
6533 pg_data_t
*pgdat
= NODE_DATA(nid
);
6534 free_area_init_node(nid
, NULL
,
6535 find_min_pfn_for_node(nid
), NULL
);
6537 /* Any memory on that node */
6538 if (pgdat
->node_present_pages
)
6539 node_set_state(nid
, N_MEMORY
);
6540 check_for_memory(pgdat
, nid
);
6544 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6546 unsigned long long coremem
;
6550 coremem
= memparse(p
, &p
);
6551 *core
= coremem
>> PAGE_SHIFT
;
6553 /* Paranoid check that UL is enough for the coremem value */
6554 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6560 * kernelcore=size sets the amount of memory for use for allocations that
6561 * cannot be reclaimed or migrated.
6563 static int __init
cmdline_parse_kernelcore(char *p
)
6565 /* parse kernelcore=mirror */
6566 if (parse_option_str(p
, "mirror")) {
6567 mirrored_kernelcore
= true;
6571 return cmdline_parse_core(p
, &required_kernelcore
);
6575 * movablecore=size sets the amount of memory for use for allocations that
6576 * can be reclaimed or migrated.
6578 static int __init
cmdline_parse_movablecore(char *p
)
6580 return cmdline_parse_core(p
, &required_movablecore
);
6583 early_param("kernelcore", cmdline_parse_kernelcore
);
6584 early_param("movablecore", cmdline_parse_movablecore
);
6586 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6588 void adjust_managed_page_count(struct page
*page
, long count
)
6590 spin_lock(&managed_page_count_lock
);
6591 page_zone(page
)->managed_pages
+= count
;
6592 totalram_pages
+= count
;
6593 #ifdef CONFIG_HIGHMEM
6594 if (PageHighMem(page
))
6595 totalhigh_pages
+= count
;
6597 spin_unlock(&managed_page_count_lock
);
6599 EXPORT_SYMBOL(adjust_managed_page_count
);
6601 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6604 unsigned long pages
= 0;
6606 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6607 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6608 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6609 if ((unsigned int)poison
<= 0xFF)
6610 memset(pos
, poison
, PAGE_SIZE
);
6611 free_reserved_page(virt_to_page(pos
));
6615 pr_info("Freeing %s memory: %ldK\n",
6616 s
, pages
<< (PAGE_SHIFT
- 10));
6620 EXPORT_SYMBOL(free_reserved_area
);
6622 #ifdef CONFIG_HIGHMEM
6623 void free_highmem_page(struct page
*page
)
6625 __free_reserved_page(page
);
6627 page_zone(page
)->managed_pages
++;
6633 void __init
mem_init_print_info(const char *str
)
6635 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6636 unsigned long init_code_size
, init_data_size
;
6638 physpages
= get_num_physpages();
6639 codesize
= _etext
- _stext
;
6640 datasize
= _edata
- _sdata
;
6641 rosize
= __end_rodata
- __start_rodata
;
6642 bss_size
= __bss_stop
- __bss_start
;
6643 init_data_size
= __init_end
- __init_begin
;
6644 init_code_size
= _einittext
- _sinittext
;
6647 * Detect special cases and adjust section sizes accordingly:
6648 * 1) .init.* may be embedded into .data sections
6649 * 2) .init.text.* may be out of [__init_begin, __init_end],
6650 * please refer to arch/tile/kernel/vmlinux.lds.S.
6651 * 3) .rodata.* may be embedded into .text or .data sections.
6653 #define adj_init_size(start, end, size, pos, adj) \
6655 if (start <= pos && pos < end && size > adj) \
6659 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6660 _sinittext
, init_code_size
);
6661 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6662 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6663 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6664 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6666 #undef adj_init_size
6668 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6669 #ifdef CONFIG_HIGHMEM
6673 nr_free_pages() << (PAGE_SHIFT
- 10),
6674 physpages
<< (PAGE_SHIFT
- 10),
6675 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6676 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6677 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6678 totalcma_pages
<< (PAGE_SHIFT
- 10),
6679 #ifdef CONFIG_HIGHMEM
6680 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6682 str
? ", " : "", str
? str
: "");
6686 * set_dma_reserve - set the specified number of pages reserved in the first zone
6687 * @new_dma_reserve: The number of pages to mark reserved
6689 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6690 * In the DMA zone, a significant percentage may be consumed by kernel image
6691 * and other unfreeable allocations which can skew the watermarks badly. This
6692 * function may optionally be used to account for unfreeable pages in the
6693 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6694 * smaller per-cpu batchsize.
6696 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6698 dma_reserve
= new_dma_reserve
;
6701 void __init
free_area_init(unsigned long *zones_size
)
6703 free_area_init_node(0, zones_size
,
6704 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6707 static int page_alloc_cpu_dead(unsigned int cpu
)
6710 lru_add_drain_cpu(cpu
);
6714 * Spill the event counters of the dead processor
6715 * into the current processors event counters.
6716 * This artificially elevates the count of the current
6719 vm_events_fold_cpu(cpu
);
6722 * Zero the differential counters of the dead processor
6723 * so that the vm statistics are consistent.
6725 * This is only okay since the processor is dead and cannot
6726 * race with what we are doing.
6728 cpu_vm_stats_fold(cpu
);
6732 void __init
page_alloc_init(void)
6736 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
6737 "mm/page_alloc:dead", NULL
,
6738 page_alloc_cpu_dead
);
6743 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6744 * or min_free_kbytes changes.
6746 static void calculate_totalreserve_pages(void)
6748 struct pglist_data
*pgdat
;
6749 unsigned long reserve_pages
= 0;
6750 enum zone_type i
, j
;
6752 for_each_online_pgdat(pgdat
) {
6754 pgdat
->totalreserve_pages
= 0;
6756 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6757 struct zone
*zone
= pgdat
->node_zones
+ i
;
6760 /* Find valid and maximum lowmem_reserve in the zone */
6761 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6762 if (zone
->lowmem_reserve
[j
] > max
)
6763 max
= zone
->lowmem_reserve
[j
];
6766 /* we treat the high watermark as reserved pages. */
6767 max
+= high_wmark_pages(zone
);
6769 if (max
> zone
->managed_pages
)
6770 max
= zone
->managed_pages
;
6772 pgdat
->totalreserve_pages
+= max
;
6774 reserve_pages
+= max
;
6777 totalreserve_pages
= reserve_pages
;
6781 * setup_per_zone_lowmem_reserve - called whenever
6782 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6783 * has a correct pages reserved value, so an adequate number of
6784 * pages are left in the zone after a successful __alloc_pages().
6786 static void setup_per_zone_lowmem_reserve(void)
6788 struct pglist_data
*pgdat
;
6789 enum zone_type j
, idx
;
6791 for_each_online_pgdat(pgdat
) {
6792 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6793 struct zone
*zone
= pgdat
->node_zones
+ j
;
6794 unsigned long managed_pages
= zone
->managed_pages
;
6796 zone
->lowmem_reserve
[j
] = 0;
6800 struct zone
*lower_zone
;
6804 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6805 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6807 lower_zone
= pgdat
->node_zones
+ idx
;
6808 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6809 sysctl_lowmem_reserve_ratio
[idx
];
6810 managed_pages
+= lower_zone
->managed_pages
;
6815 /* update totalreserve_pages */
6816 calculate_totalreserve_pages();
6819 static void __setup_per_zone_wmarks(void)
6821 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6822 unsigned long lowmem_pages
= 0;
6824 unsigned long flags
;
6826 /* Calculate total number of !ZONE_HIGHMEM pages */
6827 for_each_zone(zone
) {
6828 if (!is_highmem(zone
))
6829 lowmem_pages
+= zone
->managed_pages
;
6832 for_each_zone(zone
) {
6835 spin_lock_irqsave(&zone
->lock
, flags
);
6836 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6837 do_div(tmp
, lowmem_pages
);
6838 if (is_highmem(zone
)) {
6840 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6841 * need highmem pages, so cap pages_min to a small
6844 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6845 * deltas control asynch page reclaim, and so should
6846 * not be capped for highmem.
6848 unsigned long min_pages
;
6850 min_pages
= zone
->managed_pages
/ 1024;
6851 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6852 zone
->watermark
[WMARK_MIN
] = min_pages
;
6855 * If it's a lowmem zone, reserve a number of pages
6856 * proportionate to the zone's size.
6858 zone
->watermark
[WMARK_MIN
] = tmp
;
6862 * Set the kswapd watermarks distance according to the
6863 * scale factor in proportion to available memory, but
6864 * ensure a minimum size on small systems.
6866 tmp
= max_t(u64
, tmp
>> 2,
6867 mult_frac(zone
->managed_pages
,
6868 watermark_scale_factor
, 10000));
6870 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6871 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6873 spin_unlock_irqrestore(&zone
->lock
, flags
);
6876 /* update totalreserve_pages */
6877 calculate_totalreserve_pages();
6881 * setup_per_zone_wmarks - called when min_free_kbytes changes
6882 * or when memory is hot-{added|removed}
6884 * Ensures that the watermark[min,low,high] values for each zone are set
6885 * correctly with respect to min_free_kbytes.
6887 void setup_per_zone_wmarks(void)
6889 mutex_lock(&zonelists_mutex
);
6890 __setup_per_zone_wmarks();
6891 mutex_unlock(&zonelists_mutex
);
6895 * Initialise min_free_kbytes.
6897 * For small machines we want it small (128k min). For large machines
6898 * we want it large (64MB max). But it is not linear, because network
6899 * bandwidth does not increase linearly with machine size. We use
6901 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6902 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6918 int __meminit
init_per_zone_wmark_min(void)
6920 unsigned long lowmem_kbytes
;
6921 int new_min_free_kbytes
;
6923 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6924 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6926 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6927 min_free_kbytes
= new_min_free_kbytes
;
6928 if (min_free_kbytes
< 128)
6929 min_free_kbytes
= 128;
6930 if (min_free_kbytes
> 65536)
6931 min_free_kbytes
= 65536;
6933 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6934 new_min_free_kbytes
, user_min_free_kbytes
);
6936 setup_per_zone_wmarks();
6937 refresh_zone_stat_thresholds();
6938 setup_per_zone_lowmem_reserve();
6941 setup_min_unmapped_ratio();
6942 setup_min_slab_ratio();
6947 core_initcall(init_per_zone_wmark_min
)
6950 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6951 * that we can call two helper functions whenever min_free_kbytes
6954 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6955 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6959 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6964 user_min_free_kbytes
= min_free_kbytes
;
6965 setup_per_zone_wmarks();
6970 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6971 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6975 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6980 setup_per_zone_wmarks();
6986 static void setup_min_unmapped_ratio(void)
6991 for_each_online_pgdat(pgdat
)
6992 pgdat
->min_unmapped_pages
= 0;
6995 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
6996 sysctl_min_unmapped_ratio
) / 100;
7000 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7001 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7005 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7009 setup_min_unmapped_ratio();
7014 static void setup_min_slab_ratio(void)
7019 for_each_online_pgdat(pgdat
)
7020 pgdat
->min_slab_pages
= 0;
7023 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
7024 sysctl_min_slab_ratio
) / 100;
7027 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7028 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7032 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7036 setup_min_slab_ratio();
7043 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7044 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7045 * whenever sysctl_lowmem_reserve_ratio changes.
7047 * The reserve ratio obviously has absolutely no relation with the
7048 * minimum watermarks. The lowmem reserve ratio can only make sense
7049 * if in function of the boot time zone sizes.
7051 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7052 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7054 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7055 setup_per_zone_lowmem_reserve();
7060 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7061 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7062 * pagelist can have before it gets flushed back to buddy allocator.
7064 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7065 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7068 int old_percpu_pagelist_fraction
;
7071 mutex_lock(&pcp_batch_high_lock
);
7072 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7074 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7075 if (!write
|| ret
< 0)
7078 /* Sanity checking to avoid pcp imbalance */
7079 if (percpu_pagelist_fraction
&&
7080 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7081 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7087 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7090 for_each_populated_zone(zone
) {
7093 for_each_possible_cpu(cpu
)
7094 pageset_set_high_and_batch(zone
,
7095 per_cpu_ptr(zone
->pageset
, cpu
));
7098 mutex_unlock(&pcp_batch_high_lock
);
7103 int hashdist
= HASHDIST_DEFAULT
;
7105 static int __init
set_hashdist(char *str
)
7109 hashdist
= simple_strtoul(str
, &str
, 0);
7112 __setup("hashdist=", set_hashdist
);
7115 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7117 * Returns the number of pages that arch has reserved but
7118 * is not known to alloc_large_system_hash().
7120 static unsigned long __init
arch_reserved_kernel_pages(void)
7127 * allocate a large system hash table from bootmem
7128 * - it is assumed that the hash table must contain an exact power-of-2
7129 * quantity of entries
7130 * - limit is the number of hash buckets, not the total allocation size
7132 void *__init
alloc_large_system_hash(const char *tablename
,
7133 unsigned long bucketsize
,
7134 unsigned long numentries
,
7137 unsigned int *_hash_shift
,
7138 unsigned int *_hash_mask
,
7139 unsigned long low_limit
,
7140 unsigned long high_limit
)
7142 unsigned long long max
= high_limit
;
7143 unsigned long log2qty
, size
;
7146 /* allow the kernel cmdline to have a say */
7148 /* round applicable memory size up to nearest megabyte */
7149 numentries
= nr_kernel_pages
;
7150 numentries
-= arch_reserved_kernel_pages();
7152 /* It isn't necessary when PAGE_SIZE >= 1MB */
7153 if (PAGE_SHIFT
< 20)
7154 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7156 /* limit to 1 bucket per 2^scale bytes of low memory */
7157 if (scale
> PAGE_SHIFT
)
7158 numentries
>>= (scale
- PAGE_SHIFT
);
7160 numentries
<<= (PAGE_SHIFT
- scale
);
7162 /* Make sure we've got at least a 0-order allocation.. */
7163 if (unlikely(flags
& HASH_SMALL
)) {
7164 /* Makes no sense without HASH_EARLY */
7165 WARN_ON(!(flags
& HASH_EARLY
));
7166 if (!(numentries
>> *_hash_shift
)) {
7167 numentries
= 1UL << *_hash_shift
;
7168 BUG_ON(!numentries
);
7170 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7171 numentries
= PAGE_SIZE
/ bucketsize
;
7173 numentries
= roundup_pow_of_two(numentries
);
7175 /* limit allocation size to 1/16 total memory by default */
7177 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7178 do_div(max
, bucketsize
);
7180 max
= min(max
, 0x80000000ULL
);
7182 if (numentries
< low_limit
)
7183 numentries
= low_limit
;
7184 if (numentries
> max
)
7187 log2qty
= ilog2(numentries
);
7190 size
= bucketsize
<< log2qty
;
7191 if (flags
& HASH_EARLY
)
7192 table
= memblock_virt_alloc_nopanic(size
, 0);
7194 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
7197 * If bucketsize is not a power-of-two, we may free
7198 * some pages at the end of hash table which
7199 * alloc_pages_exact() automatically does
7201 if (get_order(size
) < MAX_ORDER
) {
7202 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
7203 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
7206 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7209 panic("Failed to allocate %s hash table\n", tablename
);
7211 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7212 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7215 *_hash_shift
= log2qty
;
7217 *_hash_mask
= (1 << log2qty
) - 1;
7223 * This function checks whether pageblock includes unmovable pages or not.
7224 * If @count is not zero, it is okay to include less @count unmovable pages
7226 * PageLRU check without isolation or lru_lock could race so that
7227 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7228 * check without lock_page also may miss some movable non-lru pages at
7229 * race condition. So you can't expect this function should be exact.
7231 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7232 bool skip_hwpoisoned_pages
)
7234 unsigned long pfn
, iter
, found
;
7238 * For avoiding noise data, lru_add_drain_all() should be called
7239 * If ZONE_MOVABLE, the zone never contains unmovable pages
7241 if (zone_idx(zone
) == ZONE_MOVABLE
)
7243 mt
= get_pageblock_migratetype(page
);
7244 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7247 pfn
= page_to_pfn(page
);
7248 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7249 unsigned long check
= pfn
+ iter
;
7251 if (!pfn_valid_within(check
))
7254 page
= pfn_to_page(check
);
7257 * Hugepages are not in LRU lists, but they're movable.
7258 * We need not scan over tail pages bacause we don't
7259 * handle each tail page individually in migration.
7261 if (PageHuge(page
)) {
7262 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7267 * We can't use page_count without pin a page
7268 * because another CPU can free compound page.
7269 * This check already skips compound tails of THP
7270 * because their page->_refcount is zero at all time.
7272 if (!page_ref_count(page
)) {
7273 if (PageBuddy(page
))
7274 iter
+= (1 << page_order(page
)) - 1;
7279 * The HWPoisoned page may be not in buddy system, and
7280 * page_count() is not 0.
7282 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7285 if (__PageMovable(page
))
7291 * If there are RECLAIMABLE pages, we need to check
7292 * it. But now, memory offline itself doesn't call
7293 * shrink_node_slabs() and it still to be fixed.
7296 * If the page is not RAM, page_count()should be 0.
7297 * we don't need more check. This is an _used_ not-movable page.
7299 * The problematic thing here is PG_reserved pages. PG_reserved
7300 * is set to both of a memory hole page and a _used_ kernel
7309 bool is_pageblock_removable_nolock(struct page
*page
)
7315 * We have to be careful here because we are iterating over memory
7316 * sections which are not zone aware so we might end up outside of
7317 * the zone but still within the section.
7318 * We have to take care about the node as well. If the node is offline
7319 * its NODE_DATA will be NULL - see page_zone.
7321 if (!node_online(page_to_nid(page
)))
7324 zone
= page_zone(page
);
7325 pfn
= page_to_pfn(page
);
7326 if (!zone_spans_pfn(zone
, pfn
))
7329 return !has_unmovable_pages(zone
, page
, 0, true);
7332 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7334 static unsigned long pfn_max_align_down(unsigned long pfn
)
7336 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7337 pageblock_nr_pages
) - 1);
7340 static unsigned long pfn_max_align_up(unsigned long pfn
)
7342 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7343 pageblock_nr_pages
));
7346 /* [start, end) must belong to a single zone. */
7347 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7348 unsigned long start
, unsigned long end
)
7350 /* This function is based on compact_zone() from compaction.c. */
7351 unsigned long nr_reclaimed
;
7352 unsigned long pfn
= start
;
7353 unsigned int tries
= 0;
7358 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7359 if (fatal_signal_pending(current
)) {
7364 if (list_empty(&cc
->migratepages
)) {
7365 cc
->nr_migratepages
= 0;
7366 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7372 } else if (++tries
== 5) {
7373 ret
= ret
< 0 ? ret
: -EBUSY
;
7377 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7379 cc
->nr_migratepages
-= nr_reclaimed
;
7381 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7382 NULL
, 0, cc
->mode
, MR_CMA
);
7385 putback_movable_pages(&cc
->migratepages
);
7392 * alloc_contig_range() -- tries to allocate given range of pages
7393 * @start: start PFN to allocate
7394 * @end: one-past-the-last PFN to allocate
7395 * @migratetype: migratetype of the underlaying pageblocks (either
7396 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7397 * in range must have the same migratetype and it must
7398 * be either of the two.
7399 * @gfp_mask: GFP mask to use during compaction
7401 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7402 * aligned, however it's the caller's responsibility to guarantee that
7403 * we are the only thread that changes migrate type of pageblocks the
7406 * The PFN range must belong to a single zone.
7408 * Returns zero on success or negative error code. On success all
7409 * pages which PFN is in [start, end) are allocated for the caller and
7410 * need to be freed with free_contig_range().
7412 int alloc_contig_range(unsigned long start
, unsigned long end
,
7413 unsigned migratetype
, gfp_t gfp_mask
)
7415 unsigned long outer_start
, outer_end
;
7419 struct compact_control cc
= {
7420 .nr_migratepages
= 0,
7422 .zone
= page_zone(pfn_to_page(start
)),
7423 .mode
= MIGRATE_SYNC
,
7424 .ignore_skip_hint
= true,
7425 .gfp_mask
= memalloc_noio_flags(gfp_mask
),
7427 INIT_LIST_HEAD(&cc
.migratepages
);
7430 * What we do here is we mark all pageblocks in range as
7431 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7432 * have different sizes, and due to the way page allocator
7433 * work, we align the range to biggest of the two pages so
7434 * that page allocator won't try to merge buddies from
7435 * different pageblocks and change MIGRATE_ISOLATE to some
7436 * other migration type.
7438 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7439 * migrate the pages from an unaligned range (ie. pages that
7440 * we are interested in). This will put all the pages in
7441 * range back to page allocator as MIGRATE_ISOLATE.
7443 * When this is done, we take the pages in range from page
7444 * allocator removing them from the buddy system. This way
7445 * page allocator will never consider using them.
7447 * This lets us mark the pageblocks back as
7448 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7449 * aligned range but not in the unaligned, original range are
7450 * put back to page allocator so that buddy can use them.
7453 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7454 pfn_max_align_up(end
), migratetype
,
7460 * In case of -EBUSY, we'd like to know which page causes problem.
7461 * So, just fall through. We will check it in test_pages_isolated().
7463 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7464 if (ret
&& ret
!= -EBUSY
)
7468 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7469 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7470 * more, all pages in [start, end) are free in page allocator.
7471 * What we are going to do is to allocate all pages from
7472 * [start, end) (that is remove them from page allocator).
7474 * The only problem is that pages at the beginning and at the
7475 * end of interesting range may be not aligned with pages that
7476 * page allocator holds, ie. they can be part of higher order
7477 * pages. Because of this, we reserve the bigger range and
7478 * once this is done free the pages we are not interested in.
7480 * We don't have to hold zone->lock here because the pages are
7481 * isolated thus they won't get removed from buddy.
7484 lru_add_drain_all();
7485 drain_all_pages(cc
.zone
);
7488 outer_start
= start
;
7489 while (!PageBuddy(pfn_to_page(outer_start
))) {
7490 if (++order
>= MAX_ORDER
) {
7491 outer_start
= start
;
7494 outer_start
&= ~0UL << order
;
7497 if (outer_start
!= start
) {
7498 order
= page_order(pfn_to_page(outer_start
));
7501 * outer_start page could be small order buddy page and
7502 * it doesn't include start page. Adjust outer_start
7503 * in this case to report failed page properly
7504 * on tracepoint in test_pages_isolated()
7506 if (outer_start
+ (1UL << order
) <= start
)
7507 outer_start
= start
;
7510 /* Make sure the range is really isolated. */
7511 if (test_pages_isolated(outer_start
, end
, false)) {
7512 pr_info("%s: [%lx, %lx) PFNs busy\n",
7513 __func__
, outer_start
, end
);
7518 /* Grab isolated pages from freelists. */
7519 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7525 /* Free head and tail (if any) */
7526 if (start
!= outer_start
)
7527 free_contig_range(outer_start
, start
- outer_start
);
7528 if (end
!= outer_end
)
7529 free_contig_range(end
, outer_end
- end
);
7532 undo_isolate_page_range(pfn_max_align_down(start
),
7533 pfn_max_align_up(end
), migratetype
);
7537 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7539 unsigned int count
= 0;
7541 for (; nr_pages
--; pfn
++) {
7542 struct page
*page
= pfn_to_page(pfn
);
7544 count
+= page_count(page
) != 1;
7547 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7551 #ifdef CONFIG_MEMORY_HOTPLUG
7553 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7554 * page high values need to be recalulated.
7556 void __meminit
zone_pcp_update(struct zone
*zone
)
7559 mutex_lock(&pcp_batch_high_lock
);
7560 for_each_possible_cpu(cpu
)
7561 pageset_set_high_and_batch(zone
,
7562 per_cpu_ptr(zone
->pageset
, cpu
));
7563 mutex_unlock(&pcp_batch_high_lock
);
7567 void zone_pcp_reset(struct zone
*zone
)
7569 unsigned long flags
;
7571 struct per_cpu_pageset
*pset
;
7573 /* avoid races with drain_pages() */
7574 local_irq_save(flags
);
7575 if (zone
->pageset
!= &boot_pageset
) {
7576 for_each_online_cpu(cpu
) {
7577 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7578 drain_zonestat(zone
, pset
);
7580 free_percpu(zone
->pageset
);
7581 zone
->pageset
= &boot_pageset
;
7583 local_irq_restore(flags
);
7586 #ifdef CONFIG_MEMORY_HOTREMOVE
7588 * All pages in the range must be in a single zone and isolated
7589 * before calling this.
7592 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7596 unsigned int order
, i
;
7598 unsigned long flags
;
7599 /* find the first valid pfn */
7600 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7605 zone
= page_zone(pfn_to_page(pfn
));
7606 spin_lock_irqsave(&zone
->lock
, flags
);
7608 while (pfn
< end_pfn
) {
7609 if (!pfn_valid(pfn
)) {
7613 page
= pfn_to_page(pfn
);
7615 * The HWPoisoned page may be not in buddy system, and
7616 * page_count() is not 0.
7618 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7620 SetPageReserved(page
);
7624 BUG_ON(page_count(page
));
7625 BUG_ON(!PageBuddy(page
));
7626 order
= page_order(page
);
7627 #ifdef CONFIG_DEBUG_VM
7628 pr_info("remove from free list %lx %d %lx\n",
7629 pfn
, 1 << order
, end_pfn
);
7631 list_del(&page
->lru
);
7632 rmv_page_order(page
);
7633 zone
->free_area
[order
].nr_free
--;
7634 for (i
= 0; i
< (1 << order
); i
++)
7635 SetPageReserved((page
+i
));
7636 pfn
+= (1 << order
);
7638 spin_unlock_irqrestore(&zone
->lock
, flags
);
7642 bool is_free_buddy_page(struct page
*page
)
7644 struct zone
*zone
= page_zone(page
);
7645 unsigned long pfn
= page_to_pfn(page
);
7646 unsigned long flags
;
7649 spin_lock_irqsave(&zone
->lock
, flags
);
7650 for (order
= 0; order
< MAX_ORDER
; order
++) {
7651 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7653 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7656 spin_unlock_irqrestore(&zone
->lock
, flags
);
7658 return order
< MAX_ORDER
;