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/sched/mm.h>
65 #include <linux/page_owner.h>
66 #include <linux/kthread.h>
67 #include <linux/memcontrol.h>
68 #include <linux/ftrace.h>
69 #include <linux/nmi.h>
71 #include <asm/sections.h>
72 #include <asm/tlbflush.h>
73 #include <asm/div64.h>
76 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
77 static DEFINE_MUTEX(pcp_batch_high_lock
);
78 #define MIN_PERCPU_PAGELIST_FRACTION (8)
80 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
81 DEFINE_PER_CPU(int, numa_node
);
82 EXPORT_PER_CPU_SYMBOL(numa_node
);
85 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
87 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
88 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
89 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
90 * defined in <linux/topology.h>.
92 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
93 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
94 int _node_numa_mem_
[MAX_NUMNODES
];
97 /* work_structs for global per-cpu drains */
98 DEFINE_MUTEX(pcpu_drain_mutex
);
99 DEFINE_PER_CPU(struct work_struct
, pcpu_drain
);
101 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
102 volatile unsigned long latent_entropy __latent_entropy
;
103 EXPORT_SYMBOL(latent_entropy
);
107 * Array of node states.
109 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
110 [N_POSSIBLE
] = NODE_MASK_ALL
,
111 [N_ONLINE
] = { { [0] = 1UL } },
113 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
114 #ifdef CONFIG_HIGHMEM
115 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
117 [N_MEMORY
] = { { [0] = 1UL } },
118 [N_CPU
] = { { [0] = 1UL } },
121 EXPORT_SYMBOL(node_states
);
123 /* Protect totalram_pages and zone->managed_pages */
124 static DEFINE_SPINLOCK(managed_page_count_lock
);
126 unsigned long totalram_pages __read_mostly
;
127 unsigned long totalreserve_pages __read_mostly
;
128 unsigned long totalcma_pages __read_mostly
;
130 int percpu_pagelist_fraction
;
131 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
134 * A cached value of the page's pageblock's migratetype, used when the page is
135 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
136 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
137 * Also the migratetype set in the page does not necessarily match the pcplist
138 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
139 * other index - this ensures that it will be put on the correct CMA freelist.
141 static inline int get_pcppage_migratetype(struct page
*page
)
146 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
148 page
->index
= migratetype
;
151 #ifdef CONFIG_PM_SLEEP
153 * The following functions are used by the suspend/hibernate code to temporarily
154 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
155 * while devices are suspended. To avoid races with the suspend/hibernate code,
156 * they should always be called with pm_mutex held (gfp_allowed_mask also should
157 * only be modified with pm_mutex held, unless the suspend/hibernate code is
158 * guaranteed not to run in parallel with that modification).
161 static gfp_t saved_gfp_mask
;
163 void pm_restore_gfp_mask(void)
165 WARN_ON(!mutex_is_locked(&pm_mutex
));
166 if (saved_gfp_mask
) {
167 gfp_allowed_mask
= saved_gfp_mask
;
172 void pm_restrict_gfp_mask(void)
174 WARN_ON(!mutex_is_locked(&pm_mutex
));
175 WARN_ON(saved_gfp_mask
);
176 saved_gfp_mask
= gfp_allowed_mask
;
177 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
180 bool pm_suspended_storage(void)
182 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
186 #endif /* CONFIG_PM_SLEEP */
188 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
189 unsigned int pageblock_order __read_mostly
;
192 static void __free_pages_ok(struct page
*page
, unsigned int order
);
195 * results with 256, 32 in the lowmem_reserve sysctl:
196 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
197 * 1G machine -> (16M dma, 784M normal, 224M high)
198 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
199 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
200 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
202 * TBD: should special case ZONE_DMA32 machines here - in those we normally
203 * don't need any ZONE_NORMAL reservation
205 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
206 #ifdef CONFIG_ZONE_DMA
209 #ifdef CONFIG_ZONE_DMA32
212 #ifdef CONFIG_HIGHMEM
218 EXPORT_SYMBOL(totalram_pages
);
220 static char * const zone_names
[MAX_NR_ZONES
] = {
221 #ifdef CONFIG_ZONE_DMA
224 #ifdef CONFIG_ZONE_DMA32
228 #ifdef CONFIG_HIGHMEM
232 #ifdef CONFIG_ZONE_DEVICE
237 char * const migratetype_names
[MIGRATE_TYPES
] = {
245 #ifdef CONFIG_MEMORY_ISOLATION
250 compound_page_dtor
* const compound_page_dtors
[] = {
253 #ifdef CONFIG_HUGETLB_PAGE
256 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
261 int min_free_kbytes
= 1024;
262 int user_min_free_kbytes
= -1;
263 int watermark_scale_factor
= 10;
265 static unsigned long __meminitdata nr_kernel_pages
;
266 static unsigned long __meminitdata nr_all_pages
;
267 static unsigned long __meminitdata dma_reserve
;
269 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
270 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
271 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
272 static unsigned long __initdata required_kernelcore
;
273 static unsigned long __initdata required_movablecore
;
274 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
275 static bool mirrored_kernelcore
;
277 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
279 EXPORT_SYMBOL(movable_zone
);
280 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
283 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
284 int nr_online_nodes __read_mostly
= 1;
285 EXPORT_SYMBOL(nr_node_ids
);
286 EXPORT_SYMBOL(nr_online_nodes
);
289 int page_group_by_mobility_disabled __read_mostly
;
291 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
292 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
294 unsigned long max_initialise
;
295 unsigned long reserved_lowmem
;
298 * Initialise at least 2G of a node but also take into account that
299 * two large system hashes that can take up 1GB for 0.25TB/node.
301 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
302 (pgdat
->node_spanned_pages
>> 8));
305 * Compensate the all the memblock reservations (e.g. crash kernel)
306 * from the initial estimation to make sure we will initialize enough
309 reserved_lowmem
= memblock_reserved_memory_within(pgdat
->node_start_pfn
,
310 pgdat
->node_start_pfn
+ max_initialise
);
311 max_initialise
+= reserved_lowmem
;
313 pgdat
->static_init_size
= min(max_initialise
, pgdat
->node_spanned_pages
);
314 pgdat
->first_deferred_pfn
= ULONG_MAX
;
317 /* Returns true if the struct page for the pfn is uninitialised */
318 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
320 int nid
= early_pfn_to_nid(pfn
);
322 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
329 * Returns false when the remaining initialisation should be deferred until
330 * later in the boot cycle when it can be parallelised.
332 static inline bool update_defer_init(pg_data_t
*pgdat
,
333 unsigned long pfn
, unsigned long zone_end
,
334 unsigned long *nr_initialised
)
336 /* Always populate low zones for address-contrained allocations */
337 if (zone_end
< pgdat_end_pfn(pgdat
))
340 if ((*nr_initialised
> pgdat
->static_init_size
) &&
341 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
342 pgdat
->first_deferred_pfn
= pfn
;
349 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
353 static inline bool early_page_uninitialised(unsigned long pfn
)
358 static inline bool update_defer_init(pg_data_t
*pgdat
,
359 unsigned long pfn
, unsigned long zone_end
,
360 unsigned long *nr_initialised
)
366 /* Return a pointer to the bitmap storing bits affecting a block of pages */
367 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
370 #ifdef CONFIG_SPARSEMEM
371 return __pfn_to_section(pfn
)->pageblock_flags
;
373 return page_zone(page
)->pageblock_flags
;
374 #endif /* CONFIG_SPARSEMEM */
377 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
379 #ifdef CONFIG_SPARSEMEM
380 pfn
&= (PAGES_PER_SECTION
-1);
381 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
383 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
384 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
385 #endif /* CONFIG_SPARSEMEM */
389 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
390 * @page: The page within the block of interest
391 * @pfn: The target page frame number
392 * @end_bitidx: The last bit of interest to retrieve
393 * @mask: mask of bits that the caller is interested in
395 * Return: pageblock_bits flags
397 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
399 unsigned long end_bitidx
,
402 unsigned long *bitmap
;
403 unsigned long bitidx
, word_bitidx
;
406 bitmap
= get_pageblock_bitmap(page
, pfn
);
407 bitidx
= pfn_to_bitidx(page
, pfn
);
408 word_bitidx
= bitidx
/ BITS_PER_LONG
;
409 bitidx
&= (BITS_PER_LONG
-1);
411 word
= bitmap
[word_bitidx
];
412 bitidx
+= end_bitidx
;
413 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
416 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
417 unsigned long end_bitidx
,
420 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
423 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
425 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
429 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
430 * @page: The page within the block of interest
431 * @flags: The flags to set
432 * @pfn: The target page frame number
433 * @end_bitidx: The last bit of interest
434 * @mask: mask of bits that the caller is interested in
436 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
438 unsigned long end_bitidx
,
441 unsigned long *bitmap
;
442 unsigned long bitidx
, word_bitidx
;
443 unsigned long old_word
, word
;
445 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
447 bitmap
= get_pageblock_bitmap(page
, pfn
);
448 bitidx
= pfn_to_bitidx(page
, pfn
);
449 word_bitidx
= bitidx
/ BITS_PER_LONG
;
450 bitidx
&= (BITS_PER_LONG
-1);
452 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
454 bitidx
+= end_bitidx
;
455 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
456 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
458 word
= READ_ONCE(bitmap
[word_bitidx
]);
460 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
461 if (word
== old_word
)
467 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
469 if (unlikely(page_group_by_mobility_disabled
&&
470 migratetype
< MIGRATE_PCPTYPES
))
471 migratetype
= MIGRATE_UNMOVABLE
;
473 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
474 PB_migrate
, PB_migrate_end
);
477 #ifdef CONFIG_DEBUG_VM
478 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
482 unsigned long pfn
= page_to_pfn(page
);
483 unsigned long sp
, start_pfn
;
486 seq
= zone_span_seqbegin(zone
);
487 start_pfn
= zone
->zone_start_pfn
;
488 sp
= zone
->spanned_pages
;
489 if (!zone_spans_pfn(zone
, pfn
))
491 } while (zone_span_seqretry(zone
, seq
));
494 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
495 pfn
, zone_to_nid(zone
), zone
->name
,
496 start_pfn
, start_pfn
+ sp
);
501 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
503 if (!pfn_valid_within(page_to_pfn(page
)))
505 if (zone
!= page_zone(page
))
511 * Temporary debugging check for pages not lying within a given zone.
513 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
515 if (page_outside_zone_boundaries(zone
, page
))
517 if (!page_is_consistent(zone
, page
))
523 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
529 static void bad_page(struct page
*page
, const char *reason
,
530 unsigned long bad_flags
)
532 static unsigned long resume
;
533 static unsigned long nr_shown
;
534 static unsigned long nr_unshown
;
537 * Allow a burst of 60 reports, then keep quiet for that minute;
538 * or allow a steady drip of one report per second.
540 if (nr_shown
== 60) {
541 if (time_before(jiffies
, resume
)) {
547 "BUG: Bad page state: %lu messages suppressed\n",
554 resume
= jiffies
+ 60 * HZ
;
556 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
557 current
->comm
, page_to_pfn(page
));
558 __dump_page(page
, reason
);
559 bad_flags
&= page
->flags
;
561 pr_alert("bad because of flags: %#lx(%pGp)\n",
562 bad_flags
, &bad_flags
);
563 dump_page_owner(page
);
568 /* Leave bad fields for debug, except PageBuddy could make trouble */
569 page_mapcount_reset(page
); /* remove PageBuddy */
570 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
574 * Higher-order pages are called "compound pages". They are structured thusly:
576 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
578 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
579 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
581 * The first tail page's ->compound_dtor holds the offset in array of compound
582 * page destructors. See compound_page_dtors.
584 * The first tail page's ->compound_order holds the order of allocation.
585 * This usage means that zero-order pages may not be compound.
588 void free_compound_page(struct page
*page
)
590 __free_pages_ok(page
, compound_order(page
));
593 void prep_compound_page(struct page
*page
, unsigned int order
)
596 int nr_pages
= 1 << order
;
598 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
599 set_compound_order(page
, order
);
601 for (i
= 1; i
< nr_pages
; i
++) {
602 struct page
*p
= page
+ i
;
603 set_page_count(p
, 0);
604 p
->mapping
= TAIL_MAPPING
;
605 set_compound_head(p
, page
);
607 atomic_set(compound_mapcount_ptr(page
), -1);
610 #ifdef CONFIG_DEBUG_PAGEALLOC
611 unsigned int _debug_guardpage_minorder
;
612 bool _debug_pagealloc_enabled __read_mostly
613 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
614 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
615 bool _debug_guardpage_enabled __read_mostly
;
617 static int __init
early_debug_pagealloc(char *buf
)
621 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
623 early_param("debug_pagealloc", early_debug_pagealloc
);
625 static bool need_debug_guardpage(void)
627 /* If we don't use debug_pagealloc, we don't need guard page */
628 if (!debug_pagealloc_enabled())
631 if (!debug_guardpage_minorder())
637 static void init_debug_guardpage(void)
639 if (!debug_pagealloc_enabled())
642 if (!debug_guardpage_minorder())
645 _debug_guardpage_enabled
= true;
648 struct page_ext_operations debug_guardpage_ops
= {
649 .need
= need_debug_guardpage
,
650 .init
= init_debug_guardpage
,
653 static int __init
debug_guardpage_minorder_setup(char *buf
)
657 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
658 pr_err("Bad debug_guardpage_minorder value\n");
661 _debug_guardpage_minorder
= res
;
662 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
665 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
667 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
668 unsigned int order
, int migratetype
)
670 struct page_ext
*page_ext
;
672 if (!debug_guardpage_enabled())
675 if (order
>= debug_guardpage_minorder())
678 page_ext
= lookup_page_ext(page
);
679 if (unlikely(!page_ext
))
682 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
684 INIT_LIST_HEAD(&page
->lru
);
685 set_page_private(page
, order
);
686 /* Guard pages are not available for any usage */
687 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
692 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
693 unsigned int order
, int migratetype
)
695 struct page_ext
*page_ext
;
697 if (!debug_guardpage_enabled())
700 page_ext
= lookup_page_ext(page
);
701 if (unlikely(!page_ext
))
704 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
706 set_page_private(page
, 0);
707 if (!is_migrate_isolate(migratetype
))
708 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
711 struct page_ext_operations debug_guardpage_ops
;
712 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
713 unsigned int order
, int migratetype
) { return false; }
714 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
715 unsigned int order
, int migratetype
) {}
718 static inline void set_page_order(struct page
*page
, unsigned int order
)
720 set_page_private(page
, order
);
721 __SetPageBuddy(page
);
724 static inline void rmv_page_order(struct page
*page
)
726 __ClearPageBuddy(page
);
727 set_page_private(page
, 0);
731 * This function checks whether a page is free && is the buddy
732 * we can do coalesce a page and its buddy if
733 * (a) the buddy is not in a hole (check before calling!) &&
734 * (b) the buddy is in the buddy system &&
735 * (c) a page and its buddy have the same order &&
736 * (d) a page and its buddy are in the same zone.
738 * For recording whether a page is in the buddy system, we set ->_mapcount
739 * PAGE_BUDDY_MAPCOUNT_VALUE.
740 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
741 * serialized by zone->lock.
743 * For recording page's order, we use page_private(page).
745 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
748 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
749 if (page_zone_id(page
) != page_zone_id(buddy
))
752 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
757 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
759 * zone check is done late to avoid uselessly
760 * calculating zone/node ids for pages that could
763 if (page_zone_id(page
) != page_zone_id(buddy
))
766 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
774 * Freeing function for a buddy system allocator.
776 * The concept of a buddy system is to maintain direct-mapped table
777 * (containing bit values) for memory blocks of various "orders".
778 * The bottom level table contains the map for the smallest allocatable
779 * units of memory (here, pages), and each level above it describes
780 * pairs of units from the levels below, hence, "buddies".
781 * At a high level, all that happens here is marking the table entry
782 * at the bottom level available, and propagating the changes upward
783 * as necessary, plus some accounting needed to play nicely with other
784 * parts of the VM system.
785 * At each level, we keep a list of pages, which are heads of continuous
786 * free pages of length of (1 << order) and marked with _mapcount
787 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
789 * So when we are allocating or freeing one, we can derive the state of the
790 * other. That is, if we allocate a small block, and both were
791 * free, the remainder of the region must be split into blocks.
792 * If a block is freed, and its buddy is also free, then this
793 * triggers coalescing into a block of larger size.
798 static inline void __free_one_page(struct page
*page
,
800 struct zone
*zone
, unsigned int order
,
803 unsigned long combined_pfn
;
804 unsigned long uninitialized_var(buddy_pfn
);
806 unsigned int max_order
;
808 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
810 VM_BUG_ON(!zone_is_initialized(zone
));
811 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
813 VM_BUG_ON(migratetype
== -1);
814 if (likely(!is_migrate_isolate(migratetype
)))
815 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
817 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
818 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
821 while (order
< max_order
- 1) {
822 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
823 buddy
= page
+ (buddy_pfn
- pfn
);
825 if (!pfn_valid_within(buddy_pfn
))
827 if (!page_is_buddy(page
, buddy
, order
))
830 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
831 * merge with it and move up one order.
833 if (page_is_guard(buddy
)) {
834 clear_page_guard(zone
, buddy
, order
, migratetype
);
836 list_del(&buddy
->lru
);
837 zone
->free_area
[order
].nr_free
--;
838 rmv_page_order(buddy
);
840 combined_pfn
= buddy_pfn
& pfn
;
841 page
= page
+ (combined_pfn
- pfn
);
845 if (max_order
< MAX_ORDER
) {
846 /* If we are here, it means order is >= pageblock_order.
847 * We want to prevent merge between freepages on isolate
848 * pageblock and normal pageblock. Without this, pageblock
849 * isolation could cause incorrect freepage or CMA accounting.
851 * We don't want to hit this code for the more frequent
854 if (unlikely(has_isolate_pageblock(zone
))) {
857 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
858 buddy
= page
+ (buddy_pfn
- pfn
);
859 buddy_mt
= get_pageblock_migratetype(buddy
);
861 if (migratetype
!= buddy_mt
862 && (is_migrate_isolate(migratetype
) ||
863 is_migrate_isolate(buddy_mt
)))
867 goto continue_merging
;
871 set_page_order(page
, order
);
874 * If this is not the largest possible page, check if the buddy
875 * of the next-highest order is free. If it is, it's possible
876 * that pages are being freed that will coalesce soon. In case,
877 * that is happening, add the free page to the tail of the list
878 * so it's less likely to be used soon and more likely to be merged
879 * as a higher order page
881 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)) {
882 struct page
*higher_page
, *higher_buddy
;
883 combined_pfn
= buddy_pfn
& pfn
;
884 higher_page
= page
+ (combined_pfn
- pfn
);
885 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
886 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
887 if (pfn_valid_within(buddy_pfn
) &&
888 page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
889 list_add_tail(&page
->lru
,
890 &zone
->free_area
[order
].free_list
[migratetype
]);
895 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
897 zone
->free_area
[order
].nr_free
++;
901 * A bad page could be due to a number of fields. Instead of multiple branches,
902 * try and check multiple fields with one check. The caller must do a detailed
903 * check if necessary.
905 static inline bool page_expected_state(struct page
*page
,
906 unsigned long check_flags
)
908 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
911 if (unlikely((unsigned long)page
->mapping
|
912 page_ref_count(page
) |
914 (unsigned long)page
->mem_cgroup
|
916 (page
->flags
& check_flags
)))
922 static void free_pages_check_bad(struct page
*page
)
924 const char *bad_reason
;
925 unsigned long bad_flags
;
930 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
931 bad_reason
= "nonzero mapcount";
932 if (unlikely(page
->mapping
!= NULL
))
933 bad_reason
= "non-NULL mapping";
934 if (unlikely(page_ref_count(page
) != 0))
935 bad_reason
= "nonzero _refcount";
936 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
937 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
938 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
941 if (unlikely(page
->mem_cgroup
))
942 bad_reason
= "page still charged to cgroup";
944 bad_page(page
, bad_reason
, bad_flags
);
947 static inline int free_pages_check(struct page
*page
)
949 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
952 /* Something has gone sideways, find it */
953 free_pages_check_bad(page
);
957 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
962 * We rely page->lru.next never has bit 0 set, unless the page
963 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
965 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
967 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
971 switch (page
- head_page
) {
973 /* the first tail page: ->mapping is compound_mapcount() */
974 if (unlikely(compound_mapcount(page
))) {
975 bad_page(page
, "nonzero compound_mapcount", 0);
981 * the second tail page: ->mapping is
982 * page_deferred_list().next -- ignore value.
986 if (page
->mapping
!= TAIL_MAPPING
) {
987 bad_page(page
, "corrupted mapping in tail page", 0);
992 if (unlikely(!PageTail(page
))) {
993 bad_page(page
, "PageTail not set", 0);
996 if (unlikely(compound_head(page
) != head_page
)) {
997 bad_page(page
, "compound_head not consistent", 0);
1002 page
->mapping
= NULL
;
1003 clear_compound_head(page
);
1007 static __always_inline
bool free_pages_prepare(struct page
*page
,
1008 unsigned int order
, bool check_free
)
1012 VM_BUG_ON_PAGE(PageTail(page
), page
);
1014 trace_mm_page_free(page
, order
);
1015 kmemcheck_free_shadow(page
, order
);
1018 * Check tail pages before head page information is cleared to
1019 * avoid checking PageCompound for order-0 pages.
1021 if (unlikely(order
)) {
1022 bool compound
= PageCompound(page
);
1025 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1028 ClearPageDoubleMap(page
);
1029 for (i
= 1; i
< (1 << order
); i
++) {
1031 bad
+= free_tail_pages_check(page
, page
+ i
);
1032 if (unlikely(free_pages_check(page
+ i
))) {
1036 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1039 if (PageMappingFlags(page
))
1040 page
->mapping
= NULL
;
1041 if (memcg_kmem_enabled() && PageKmemcg(page
))
1042 memcg_kmem_uncharge(page
, order
);
1044 bad
+= free_pages_check(page
);
1048 page_cpupid_reset_last(page
);
1049 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1050 reset_page_owner(page
, order
);
1052 if (!PageHighMem(page
)) {
1053 debug_check_no_locks_freed(page_address(page
),
1054 PAGE_SIZE
<< order
);
1055 debug_check_no_obj_freed(page_address(page
),
1056 PAGE_SIZE
<< order
);
1058 arch_free_page(page
, order
);
1059 kernel_poison_pages(page
, 1 << order
, 0);
1060 kernel_map_pages(page
, 1 << order
, 0);
1061 kasan_free_pages(page
, order
);
1066 #ifdef CONFIG_DEBUG_VM
1067 static inline bool free_pcp_prepare(struct page
*page
)
1069 return free_pages_prepare(page
, 0, true);
1072 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1077 static bool free_pcp_prepare(struct page
*page
)
1079 return free_pages_prepare(page
, 0, false);
1082 static bool bulkfree_pcp_prepare(struct page
*page
)
1084 return free_pages_check(page
);
1086 #endif /* CONFIG_DEBUG_VM */
1089 * Frees a number of pages from the PCP lists
1090 * Assumes all pages on list are in same zone, and of same order.
1091 * count is the number of pages to free.
1093 * If the zone was previously in an "all pages pinned" state then look to
1094 * see if this freeing clears that state.
1096 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1097 * pinned" detection logic.
1099 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1100 struct per_cpu_pages
*pcp
)
1102 int migratetype
= 0;
1104 bool isolated_pageblocks
;
1106 spin_lock(&zone
->lock
);
1107 isolated_pageblocks
= has_isolate_pageblock(zone
);
1111 struct list_head
*list
;
1114 * Remove pages from lists in a round-robin fashion. A
1115 * batch_free count is maintained that is incremented when an
1116 * empty list is encountered. This is so more pages are freed
1117 * off fuller lists instead of spinning excessively around empty
1122 if (++migratetype
== MIGRATE_PCPTYPES
)
1124 list
= &pcp
->lists
[migratetype
];
1125 } while (list_empty(list
));
1127 /* This is the only non-empty list. Free them all. */
1128 if (batch_free
== MIGRATE_PCPTYPES
)
1132 int mt
; /* migratetype of the to-be-freed page */
1134 page
= list_last_entry(list
, struct page
, lru
);
1135 /* must delete as __free_one_page list manipulates */
1136 list_del(&page
->lru
);
1138 mt
= get_pcppage_migratetype(page
);
1139 /* MIGRATE_ISOLATE page should not go to pcplists */
1140 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1141 /* Pageblock could have been isolated meanwhile */
1142 if (unlikely(isolated_pageblocks
))
1143 mt
= get_pageblock_migratetype(page
);
1145 if (bulkfree_pcp_prepare(page
))
1148 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1149 trace_mm_page_pcpu_drain(page
, 0, mt
);
1150 } while (--count
&& --batch_free
&& !list_empty(list
));
1152 spin_unlock(&zone
->lock
);
1155 static void free_one_page(struct zone
*zone
,
1156 struct page
*page
, unsigned long pfn
,
1160 spin_lock(&zone
->lock
);
1161 if (unlikely(has_isolate_pageblock(zone
) ||
1162 is_migrate_isolate(migratetype
))) {
1163 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1165 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1166 spin_unlock(&zone
->lock
);
1169 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1170 unsigned long zone
, int nid
)
1172 set_page_links(page
, zone
, nid
, pfn
);
1173 init_page_count(page
);
1174 page_mapcount_reset(page
);
1175 page_cpupid_reset_last(page
);
1177 INIT_LIST_HEAD(&page
->lru
);
1178 #ifdef WANT_PAGE_VIRTUAL
1179 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1180 if (!is_highmem_idx(zone
))
1181 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1185 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1188 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1191 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1192 static void init_reserved_page(unsigned long pfn
)
1197 if (!early_page_uninitialised(pfn
))
1200 nid
= early_pfn_to_nid(pfn
);
1201 pgdat
= NODE_DATA(nid
);
1203 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1204 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1206 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1209 __init_single_pfn(pfn
, zid
, nid
);
1212 static inline void init_reserved_page(unsigned long pfn
)
1215 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1218 * Initialised pages do not have PageReserved set. This function is
1219 * called for each range allocated by the bootmem allocator and
1220 * marks the pages PageReserved. The remaining valid pages are later
1221 * sent to the buddy page allocator.
1223 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1225 unsigned long start_pfn
= PFN_DOWN(start
);
1226 unsigned long end_pfn
= PFN_UP(end
);
1228 for (; start_pfn
< end_pfn
; start_pfn
++) {
1229 if (pfn_valid(start_pfn
)) {
1230 struct page
*page
= pfn_to_page(start_pfn
);
1232 init_reserved_page(start_pfn
);
1234 /* Avoid false-positive PageTail() */
1235 INIT_LIST_HEAD(&page
->lru
);
1237 SetPageReserved(page
);
1242 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1244 unsigned long flags
;
1246 unsigned long pfn
= page_to_pfn(page
);
1248 if (!free_pages_prepare(page
, order
, true))
1251 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1252 local_irq_save(flags
);
1253 __count_vm_events(PGFREE
, 1 << order
);
1254 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1255 local_irq_restore(flags
);
1258 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1260 unsigned int nr_pages
= 1 << order
;
1261 struct page
*p
= page
;
1265 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1267 __ClearPageReserved(p
);
1268 set_page_count(p
, 0);
1270 __ClearPageReserved(p
);
1271 set_page_count(p
, 0);
1273 page_zone(page
)->managed_pages
+= nr_pages
;
1274 set_page_refcounted(page
);
1275 __free_pages(page
, order
);
1278 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1279 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1281 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1283 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1285 static DEFINE_SPINLOCK(early_pfn_lock
);
1288 spin_lock(&early_pfn_lock
);
1289 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1291 nid
= first_online_node
;
1292 spin_unlock(&early_pfn_lock
);
1298 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1299 static inline bool __meminit __maybe_unused
1300 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1301 struct mminit_pfnnid_cache
*state
)
1305 nid
= __early_pfn_to_nid(pfn
, state
);
1306 if (nid
>= 0 && nid
!= node
)
1311 /* Only safe to use early in boot when initialisation is single-threaded */
1312 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1314 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1319 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1323 static inline bool __meminit __maybe_unused
1324 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1325 struct mminit_pfnnid_cache
*state
)
1332 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1335 if (early_page_uninitialised(pfn
))
1337 return __free_pages_boot_core(page
, order
);
1341 * Check that the whole (or subset of) a pageblock given by the interval of
1342 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1343 * with the migration of free compaction scanner. The scanners then need to
1344 * use only pfn_valid_within() check for arches that allow holes within
1347 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1349 * It's possible on some configurations to have a setup like node0 node1 node0
1350 * i.e. it's possible that all pages within a zones range of pages do not
1351 * belong to a single zone. We assume that a border between node0 and node1
1352 * can occur within a single pageblock, but not a node0 node1 node0
1353 * interleaving within a single pageblock. It is therefore sufficient to check
1354 * the first and last page of a pageblock and avoid checking each individual
1355 * page in a pageblock.
1357 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1358 unsigned long end_pfn
, struct zone
*zone
)
1360 struct page
*start_page
;
1361 struct page
*end_page
;
1363 /* end_pfn is one past the range we are checking */
1366 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1369 start_page
= pfn_to_online_page(start_pfn
);
1373 if (page_zone(start_page
) != zone
)
1376 end_page
= pfn_to_page(end_pfn
);
1378 /* This gives a shorter code than deriving page_zone(end_page) */
1379 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1385 void set_zone_contiguous(struct zone
*zone
)
1387 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1388 unsigned long block_end_pfn
;
1390 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1391 for (; block_start_pfn
< zone_end_pfn(zone
);
1392 block_start_pfn
= block_end_pfn
,
1393 block_end_pfn
+= pageblock_nr_pages
) {
1395 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1397 if (!__pageblock_pfn_to_page(block_start_pfn
,
1398 block_end_pfn
, zone
))
1402 /* We confirm that there is no hole */
1403 zone
->contiguous
= true;
1406 void clear_zone_contiguous(struct zone
*zone
)
1408 zone
->contiguous
= false;
1411 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1412 static void __init
deferred_free_range(struct page
*page
,
1413 unsigned long pfn
, int nr_pages
)
1420 /* Free a large naturally-aligned chunk if possible */
1421 if (nr_pages
== pageblock_nr_pages
&&
1422 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1423 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1424 __free_pages_boot_core(page
, pageblock_order
);
1428 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1429 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1430 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1431 __free_pages_boot_core(page
, 0);
1435 /* Completion tracking for deferred_init_memmap() threads */
1436 static atomic_t pgdat_init_n_undone __initdata
;
1437 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1439 static inline void __init
pgdat_init_report_one_done(void)
1441 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1442 complete(&pgdat_init_all_done_comp
);
1445 /* Initialise remaining memory on a node */
1446 static int __init
deferred_init_memmap(void *data
)
1448 pg_data_t
*pgdat
= data
;
1449 int nid
= pgdat
->node_id
;
1450 struct mminit_pfnnid_cache nid_init_state
= { };
1451 unsigned long start
= jiffies
;
1452 unsigned long nr_pages
= 0;
1453 unsigned long walk_start
, walk_end
;
1456 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1457 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1459 if (first_init_pfn
== ULONG_MAX
) {
1460 pgdat_init_report_one_done();
1464 /* Bind memory initialisation thread to a local node if possible */
1465 if (!cpumask_empty(cpumask
))
1466 set_cpus_allowed_ptr(current
, cpumask
);
1468 /* Sanity check boundaries */
1469 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1470 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1471 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1473 /* Only the highest zone is deferred so find it */
1474 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1475 zone
= pgdat
->node_zones
+ zid
;
1476 if (first_init_pfn
< zone_end_pfn(zone
))
1480 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1481 unsigned long pfn
, end_pfn
;
1482 struct page
*page
= NULL
;
1483 struct page
*free_base_page
= NULL
;
1484 unsigned long free_base_pfn
= 0;
1487 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1488 pfn
= first_init_pfn
;
1489 if (pfn
< walk_start
)
1491 if (pfn
< zone
->zone_start_pfn
)
1492 pfn
= zone
->zone_start_pfn
;
1494 for (; pfn
< end_pfn
; pfn
++) {
1495 if (!pfn_valid_within(pfn
))
1499 * Ensure pfn_valid is checked every
1500 * pageblock_nr_pages for memory holes
1502 if ((pfn
& (pageblock_nr_pages
- 1)) == 0) {
1503 if (!pfn_valid(pfn
)) {
1509 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1514 /* Minimise pfn page lookups and scheduler checks */
1515 if (page
&& (pfn
& (pageblock_nr_pages
- 1)) != 0) {
1518 nr_pages
+= nr_to_free
;
1519 deferred_free_range(free_base_page
,
1520 free_base_pfn
, nr_to_free
);
1521 free_base_page
= NULL
;
1522 free_base_pfn
= nr_to_free
= 0;
1524 page
= pfn_to_page(pfn
);
1529 VM_BUG_ON(page_zone(page
) != zone
);
1533 __init_single_page(page
, pfn
, zid
, nid
);
1534 if (!free_base_page
) {
1535 free_base_page
= page
;
1536 free_base_pfn
= pfn
;
1541 /* Where possible, batch up pages for a single free */
1544 /* Free the current block of pages to allocator */
1545 nr_pages
+= nr_to_free
;
1546 deferred_free_range(free_base_page
, free_base_pfn
,
1548 free_base_page
= NULL
;
1549 free_base_pfn
= nr_to_free
= 0;
1551 /* Free the last block of pages to allocator */
1552 nr_pages
+= nr_to_free
;
1553 deferred_free_range(free_base_page
, free_base_pfn
, nr_to_free
);
1555 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1558 /* Sanity check that the next zone really is unpopulated */
1559 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1561 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1562 jiffies_to_msecs(jiffies
- start
));
1564 pgdat_init_report_one_done();
1567 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1569 void __init
page_alloc_init_late(void)
1573 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1576 /* There will be num_node_state(N_MEMORY) threads */
1577 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1578 for_each_node_state(nid
, N_MEMORY
) {
1579 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1582 /* Block until all are initialised */
1583 wait_for_completion(&pgdat_init_all_done_comp
);
1585 /* Reinit limits that are based on free pages after the kernel is up */
1586 files_maxfiles_init();
1588 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
1589 /* Discard memblock private memory */
1593 for_each_populated_zone(zone
)
1594 set_zone_contiguous(zone
);
1598 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1599 void __init
init_cma_reserved_pageblock(struct page
*page
)
1601 unsigned i
= pageblock_nr_pages
;
1602 struct page
*p
= page
;
1605 __ClearPageReserved(p
);
1606 set_page_count(p
, 0);
1609 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1611 if (pageblock_order
>= MAX_ORDER
) {
1612 i
= pageblock_nr_pages
;
1615 set_page_refcounted(p
);
1616 __free_pages(p
, MAX_ORDER
- 1);
1617 p
+= MAX_ORDER_NR_PAGES
;
1618 } while (i
-= MAX_ORDER_NR_PAGES
);
1620 set_page_refcounted(page
);
1621 __free_pages(page
, pageblock_order
);
1624 adjust_managed_page_count(page
, pageblock_nr_pages
);
1629 * The order of subdivision here is critical for the IO subsystem.
1630 * Please do not alter this order without good reasons and regression
1631 * testing. Specifically, as large blocks of memory are subdivided,
1632 * the order in which smaller blocks are delivered depends on the order
1633 * they're subdivided in this function. This is the primary factor
1634 * influencing the order in which pages are delivered to the IO
1635 * subsystem according to empirical testing, and this is also justified
1636 * by considering the behavior of a buddy system containing a single
1637 * large block of memory acted on by a series of small allocations.
1638 * This behavior is a critical factor in sglist merging's success.
1642 static inline void expand(struct zone
*zone
, struct page
*page
,
1643 int low
, int high
, struct free_area
*area
,
1646 unsigned long size
= 1 << high
;
1648 while (high
> low
) {
1652 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1655 * Mark as guard pages (or page), that will allow to
1656 * merge back to allocator when buddy will be freed.
1657 * Corresponding page table entries will not be touched,
1658 * pages will stay not present in virtual address space
1660 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1663 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1665 set_page_order(&page
[size
], high
);
1669 static void check_new_page_bad(struct page
*page
)
1671 const char *bad_reason
= NULL
;
1672 unsigned long bad_flags
= 0;
1674 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1675 bad_reason
= "nonzero mapcount";
1676 if (unlikely(page
->mapping
!= NULL
))
1677 bad_reason
= "non-NULL mapping";
1678 if (unlikely(page_ref_count(page
) != 0))
1679 bad_reason
= "nonzero _count";
1680 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1681 bad_reason
= "HWPoisoned (hardware-corrupted)";
1682 bad_flags
= __PG_HWPOISON
;
1683 /* Don't complain about hwpoisoned pages */
1684 page_mapcount_reset(page
); /* remove PageBuddy */
1687 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1688 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1689 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1692 if (unlikely(page
->mem_cgroup
))
1693 bad_reason
= "page still charged to cgroup";
1695 bad_page(page
, bad_reason
, bad_flags
);
1699 * This page is about to be returned from the page allocator
1701 static inline int check_new_page(struct page
*page
)
1703 if (likely(page_expected_state(page
,
1704 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1707 check_new_page_bad(page
);
1711 static inline bool free_pages_prezeroed(void)
1713 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1714 page_poisoning_enabled();
1717 #ifdef CONFIG_DEBUG_VM
1718 static bool check_pcp_refill(struct page
*page
)
1723 static bool check_new_pcp(struct page
*page
)
1725 return check_new_page(page
);
1728 static bool check_pcp_refill(struct page
*page
)
1730 return check_new_page(page
);
1732 static bool check_new_pcp(struct page
*page
)
1736 #endif /* CONFIG_DEBUG_VM */
1738 static bool check_new_pages(struct page
*page
, unsigned int order
)
1741 for (i
= 0; i
< (1 << order
); i
++) {
1742 struct page
*p
= page
+ i
;
1744 if (unlikely(check_new_page(p
)))
1751 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1754 set_page_private(page
, 0);
1755 set_page_refcounted(page
);
1757 arch_alloc_page(page
, order
);
1758 kernel_map_pages(page
, 1 << order
, 1);
1759 kernel_poison_pages(page
, 1 << order
, 1);
1760 kasan_alloc_pages(page
, order
);
1761 set_page_owner(page
, order
, gfp_flags
);
1764 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1765 unsigned int alloc_flags
)
1769 post_alloc_hook(page
, order
, gfp_flags
);
1771 if (!free_pages_prezeroed() && (gfp_flags
& __GFP_ZERO
))
1772 for (i
= 0; i
< (1 << order
); i
++)
1773 clear_highpage(page
+ i
);
1775 if (order
&& (gfp_flags
& __GFP_COMP
))
1776 prep_compound_page(page
, order
);
1779 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1780 * allocate the page. The expectation is that the caller is taking
1781 * steps that will free more memory. The caller should avoid the page
1782 * being used for !PFMEMALLOC purposes.
1784 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1785 set_page_pfmemalloc(page
);
1787 clear_page_pfmemalloc(page
);
1791 * Go through the free lists for the given migratetype and remove
1792 * the smallest available page from the freelists
1795 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1798 unsigned int current_order
;
1799 struct free_area
*area
;
1802 /* Find a page of the appropriate size in the preferred list */
1803 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1804 area
= &(zone
->free_area
[current_order
]);
1805 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1809 list_del(&page
->lru
);
1810 rmv_page_order(page
);
1812 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1813 set_pcppage_migratetype(page
, migratetype
);
1822 * This array describes the order lists are fallen back to when
1823 * the free lists for the desirable migrate type are depleted
1825 static int fallbacks
[MIGRATE_TYPES
][4] = {
1826 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1827 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1828 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1830 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1832 #ifdef CONFIG_MEMORY_ISOLATION
1833 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1838 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1841 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1844 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1845 unsigned int order
) { return NULL
; }
1849 * Move the free pages in a range to the free lists of the requested type.
1850 * Note that start_page and end_pages are not aligned on a pageblock
1851 * boundary. If alignment is required, use move_freepages_block()
1853 static int move_freepages(struct zone
*zone
,
1854 struct page
*start_page
, struct page
*end_page
,
1855 int migratetype
, int *num_movable
)
1859 int pages_moved
= 0;
1861 #ifndef CONFIG_HOLES_IN_ZONE
1863 * page_zone is not safe to call in this context when
1864 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1865 * anyway as we check zone boundaries in move_freepages_block().
1866 * Remove at a later date when no bug reports exist related to
1867 * grouping pages by mobility
1869 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1875 for (page
= start_page
; page
<= end_page
;) {
1876 if (!pfn_valid_within(page_to_pfn(page
))) {
1881 /* Make sure we are not inadvertently changing nodes */
1882 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1884 if (!PageBuddy(page
)) {
1886 * We assume that pages that could be isolated for
1887 * migration are movable. But we don't actually try
1888 * isolating, as that would be expensive.
1891 (PageLRU(page
) || __PageMovable(page
)))
1898 order
= page_order(page
);
1899 list_move(&page
->lru
,
1900 &zone
->free_area
[order
].free_list
[migratetype
]);
1902 pages_moved
+= 1 << order
;
1908 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1909 int migratetype
, int *num_movable
)
1911 unsigned long start_pfn
, end_pfn
;
1912 struct page
*start_page
, *end_page
;
1914 start_pfn
= page_to_pfn(page
);
1915 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1916 start_page
= pfn_to_page(start_pfn
);
1917 end_page
= start_page
+ pageblock_nr_pages
- 1;
1918 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1920 /* Do not cross zone boundaries */
1921 if (!zone_spans_pfn(zone
, start_pfn
))
1923 if (!zone_spans_pfn(zone
, end_pfn
))
1926 return move_freepages(zone
, start_page
, end_page
, migratetype
,
1930 static void change_pageblock_range(struct page
*pageblock_page
,
1931 int start_order
, int migratetype
)
1933 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1935 while (nr_pageblocks
--) {
1936 set_pageblock_migratetype(pageblock_page
, migratetype
);
1937 pageblock_page
+= pageblock_nr_pages
;
1942 * When we are falling back to another migratetype during allocation, try to
1943 * steal extra free pages from the same pageblocks to satisfy further
1944 * allocations, instead of polluting multiple pageblocks.
1946 * If we are stealing a relatively large buddy page, it is likely there will
1947 * be more free pages in the pageblock, so try to steal them all. For
1948 * reclaimable and unmovable allocations, we steal regardless of page size,
1949 * as fragmentation caused by those allocations polluting movable pageblocks
1950 * is worse than movable allocations stealing from unmovable and reclaimable
1953 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1956 * Leaving this order check is intended, although there is
1957 * relaxed order check in next check. The reason is that
1958 * we can actually steal whole pageblock if this condition met,
1959 * but, below check doesn't guarantee it and that is just heuristic
1960 * so could be changed anytime.
1962 if (order
>= pageblock_order
)
1965 if (order
>= pageblock_order
/ 2 ||
1966 start_mt
== MIGRATE_RECLAIMABLE
||
1967 start_mt
== MIGRATE_UNMOVABLE
||
1968 page_group_by_mobility_disabled
)
1975 * This function implements actual steal behaviour. If order is large enough,
1976 * we can steal whole pageblock. If not, we first move freepages in this
1977 * pageblock to our migratetype and determine how many already-allocated pages
1978 * are there in the pageblock with a compatible migratetype. If at least half
1979 * of pages are free or compatible, we can change migratetype of the pageblock
1980 * itself, so pages freed in the future will be put on the correct free list.
1982 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1983 int start_type
, bool whole_block
)
1985 unsigned int current_order
= page_order(page
);
1986 struct free_area
*area
;
1987 int free_pages
, movable_pages
, alike_pages
;
1990 old_block_type
= get_pageblock_migratetype(page
);
1993 * This can happen due to races and we want to prevent broken
1994 * highatomic accounting.
1996 if (is_migrate_highatomic(old_block_type
))
1999 /* Take ownership for orders >= pageblock_order */
2000 if (current_order
>= pageblock_order
) {
2001 change_pageblock_range(page
, current_order
, start_type
);
2005 /* We are not allowed to try stealing from the whole block */
2009 free_pages
= move_freepages_block(zone
, page
, start_type
,
2012 * Determine how many pages are compatible with our allocation.
2013 * For movable allocation, it's the number of movable pages which
2014 * we just obtained. For other types it's a bit more tricky.
2016 if (start_type
== MIGRATE_MOVABLE
) {
2017 alike_pages
= movable_pages
;
2020 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2021 * to MOVABLE pageblock, consider all non-movable pages as
2022 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2023 * vice versa, be conservative since we can't distinguish the
2024 * exact migratetype of non-movable pages.
2026 if (old_block_type
== MIGRATE_MOVABLE
)
2027 alike_pages
= pageblock_nr_pages
2028 - (free_pages
+ movable_pages
);
2033 /* moving whole block can fail due to zone boundary conditions */
2038 * If a sufficient number of pages in the block are either free or of
2039 * comparable migratability as our allocation, claim the whole block.
2041 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2042 page_group_by_mobility_disabled
)
2043 set_pageblock_migratetype(page
, start_type
);
2048 area
= &zone
->free_area
[current_order
];
2049 list_move(&page
->lru
, &area
->free_list
[start_type
]);
2053 * Check whether there is a suitable fallback freepage with requested order.
2054 * If only_stealable is true, this function returns fallback_mt only if
2055 * we can steal other freepages all together. This would help to reduce
2056 * fragmentation due to mixed migratetype pages in one pageblock.
2058 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2059 int migratetype
, bool only_stealable
, bool *can_steal
)
2064 if (area
->nr_free
== 0)
2069 fallback_mt
= fallbacks
[migratetype
][i
];
2070 if (fallback_mt
== MIGRATE_TYPES
)
2073 if (list_empty(&area
->free_list
[fallback_mt
]))
2076 if (can_steal_fallback(order
, migratetype
))
2079 if (!only_stealable
)
2090 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2091 * there are no empty page blocks that contain a page with a suitable order
2093 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2094 unsigned int alloc_order
)
2097 unsigned long max_managed
, flags
;
2100 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2101 * Check is race-prone but harmless.
2103 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2104 if (zone
->nr_reserved_highatomic
>= max_managed
)
2107 spin_lock_irqsave(&zone
->lock
, flags
);
2109 /* Recheck the nr_reserved_highatomic limit under the lock */
2110 if (zone
->nr_reserved_highatomic
>= max_managed
)
2114 mt
= get_pageblock_migratetype(page
);
2115 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2116 && !is_migrate_cma(mt
)) {
2117 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2118 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2119 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2123 spin_unlock_irqrestore(&zone
->lock
, flags
);
2127 * Used when an allocation is about to fail under memory pressure. This
2128 * potentially hurts the reliability of high-order allocations when under
2129 * intense memory pressure but failed atomic allocations should be easier
2130 * to recover from than an OOM.
2132 * If @force is true, try to unreserve a pageblock even though highatomic
2133 * pageblock is exhausted.
2135 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2138 struct zonelist
*zonelist
= ac
->zonelist
;
2139 unsigned long flags
;
2146 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2149 * Preserve at least one pageblock unless memory pressure
2152 if (!force
&& zone
->nr_reserved_highatomic
<=
2156 spin_lock_irqsave(&zone
->lock
, flags
);
2157 for (order
= 0; order
< MAX_ORDER
; order
++) {
2158 struct free_area
*area
= &(zone
->free_area
[order
]);
2160 page
= list_first_entry_or_null(
2161 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2167 * In page freeing path, migratetype change is racy so
2168 * we can counter several free pages in a pageblock
2169 * in this loop althoug we changed the pageblock type
2170 * from highatomic to ac->migratetype. So we should
2171 * adjust the count once.
2173 if (is_migrate_highatomic_page(page
)) {
2175 * It should never happen but changes to
2176 * locking could inadvertently allow a per-cpu
2177 * drain to add pages to MIGRATE_HIGHATOMIC
2178 * while unreserving so be safe and watch for
2181 zone
->nr_reserved_highatomic
-= min(
2183 zone
->nr_reserved_highatomic
);
2187 * Convert to ac->migratetype and avoid the normal
2188 * pageblock stealing heuristics. Minimally, the caller
2189 * is doing the work and needs the pages. More
2190 * importantly, if the block was always converted to
2191 * MIGRATE_UNMOVABLE or another type then the number
2192 * of pageblocks that cannot be completely freed
2195 set_pageblock_migratetype(page
, ac
->migratetype
);
2196 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2199 spin_unlock_irqrestore(&zone
->lock
, flags
);
2203 spin_unlock_irqrestore(&zone
->lock
, flags
);
2210 * Try finding a free buddy page on the fallback list and put it on the free
2211 * list of requested migratetype, possibly along with other pages from the same
2212 * block, depending on fragmentation avoidance heuristics. Returns true if
2213 * fallback was found so that __rmqueue_smallest() can grab it.
2215 * The use of signed ints for order and current_order is a deliberate
2216 * deviation from the rest of this file, to make the for loop
2217 * condition simpler.
2220 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
2222 struct free_area
*area
;
2229 * Find the largest available free page in the other list. This roughly
2230 * approximates finding the pageblock with the most free pages, which
2231 * would be too costly to do exactly.
2233 for (current_order
= MAX_ORDER
- 1; current_order
>= order
;
2235 area
= &(zone
->free_area
[current_order
]);
2236 fallback_mt
= find_suitable_fallback(area
, current_order
,
2237 start_migratetype
, false, &can_steal
);
2238 if (fallback_mt
== -1)
2242 * We cannot steal all free pages from the pageblock and the
2243 * requested migratetype is movable. In that case it's better to
2244 * steal and split the smallest available page instead of the
2245 * largest available page, because even if the next movable
2246 * allocation falls back into a different pageblock than this
2247 * one, it won't cause permanent fragmentation.
2249 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2250 && current_order
> order
)
2259 for (current_order
= order
; current_order
< MAX_ORDER
;
2261 area
= &(zone
->free_area
[current_order
]);
2262 fallback_mt
= find_suitable_fallback(area
, current_order
,
2263 start_migratetype
, false, &can_steal
);
2264 if (fallback_mt
!= -1)
2269 * This should not happen - we already found a suitable fallback
2270 * when looking for the largest page.
2272 VM_BUG_ON(current_order
== MAX_ORDER
);
2275 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2278 steal_suitable_fallback(zone
, page
, start_migratetype
, can_steal
);
2280 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2281 start_migratetype
, fallback_mt
);
2288 * Do the hard work of removing an element from the buddy allocator.
2289 * Call me with the zone->lock already held.
2291 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2297 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2298 if (unlikely(!page
)) {
2299 if (migratetype
== MIGRATE_MOVABLE
)
2300 page
= __rmqueue_cma_fallback(zone
, order
);
2302 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
))
2306 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2311 * Obtain a specified number of elements from the buddy allocator, all under
2312 * a single hold of the lock, for efficiency. Add them to the supplied list.
2313 * Returns the number of new pages which were placed at *list.
2315 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2316 unsigned long count
, struct list_head
*list
,
2317 int migratetype
, bool cold
)
2321 spin_lock(&zone
->lock
);
2322 for (i
= 0; i
< count
; ++i
) {
2323 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2324 if (unlikely(page
== NULL
))
2327 if (unlikely(check_pcp_refill(page
)))
2331 * Split buddy pages returned by expand() are received here
2332 * in physical page order. The page is added to the callers and
2333 * list and the list head then moves forward. From the callers
2334 * perspective, the linked list is ordered by page number in
2335 * some conditions. This is useful for IO devices that can
2336 * merge IO requests if the physical pages are ordered
2340 list_add(&page
->lru
, list
);
2342 list_add_tail(&page
->lru
, list
);
2345 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2346 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2351 * i pages were removed from the buddy list even if some leak due
2352 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2353 * on i. Do not confuse with 'alloced' which is the number of
2354 * pages added to the pcp list.
2356 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2357 spin_unlock(&zone
->lock
);
2363 * Called from the vmstat counter updater to drain pagesets of this
2364 * currently executing processor on remote nodes after they have
2367 * Note that this function must be called with the thread pinned to
2368 * a single processor.
2370 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2372 unsigned long flags
;
2373 int to_drain
, batch
;
2375 local_irq_save(flags
);
2376 batch
= READ_ONCE(pcp
->batch
);
2377 to_drain
= min(pcp
->count
, batch
);
2379 free_pcppages_bulk(zone
, to_drain
, pcp
);
2380 pcp
->count
-= to_drain
;
2382 local_irq_restore(flags
);
2387 * Drain pcplists of the indicated processor and zone.
2389 * The processor must either be the current processor and the
2390 * thread pinned to the current processor or a processor that
2393 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2395 unsigned long flags
;
2396 struct per_cpu_pageset
*pset
;
2397 struct per_cpu_pages
*pcp
;
2399 local_irq_save(flags
);
2400 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2404 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2407 local_irq_restore(flags
);
2411 * Drain pcplists of all zones on the indicated processor.
2413 * The processor must either be the current processor and the
2414 * thread pinned to the current processor or a processor that
2417 static void drain_pages(unsigned int cpu
)
2421 for_each_populated_zone(zone
) {
2422 drain_pages_zone(cpu
, zone
);
2427 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2429 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2430 * the single zone's pages.
2432 void drain_local_pages(struct zone
*zone
)
2434 int cpu
= smp_processor_id();
2437 drain_pages_zone(cpu
, zone
);
2442 static void drain_local_pages_wq(struct work_struct
*work
)
2445 * drain_all_pages doesn't use proper cpu hotplug protection so
2446 * we can race with cpu offline when the WQ can move this from
2447 * a cpu pinned worker to an unbound one. We can operate on a different
2448 * cpu which is allright but we also have to make sure to not move to
2452 drain_local_pages(NULL
);
2457 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2459 * When zone parameter is non-NULL, spill just the single zone's pages.
2461 * Note that this can be extremely slow as the draining happens in a workqueue.
2463 void drain_all_pages(struct zone
*zone
)
2468 * Allocate in the BSS so we wont require allocation in
2469 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2471 static cpumask_t cpus_with_pcps
;
2474 * Make sure nobody triggers this path before mm_percpu_wq is fully
2477 if (WARN_ON_ONCE(!mm_percpu_wq
))
2480 /* Workqueues cannot recurse */
2481 if (current
->flags
& PF_WQ_WORKER
)
2485 * Do not drain if one is already in progress unless it's specific to
2486 * a zone. Such callers are primarily CMA and memory hotplug and need
2487 * the drain to be complete when the call returns.
2489 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2492 mutex_lock(&pcpu_drain_mutex
);
2496 * We don't care about racing with CPU hotplug event
2497 * as offline notification will cause the notified
2498 * cpu to drain that CPU pcps and on_each_cpu_mask
2499 * disables preemption as part of its processing
2501 for_each_online_cpu(cpu
) {
2502 struct per_cpu_pageset
*pcp
;
2504 bool has_pcps
= false;
2507 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2511 for_each_populated_zone(z
) {
2512 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2513 if (pcp
->pcp
.count
) {
2521 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2523 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2526 for_each_cpu(cpu
, &cpus_with_pcps
) {
2527 struct work_struct
*work
= per_cpu_ptr(&pcpu_drain
, cpu
);
2528 INIT_WORK(work
, drain_local_pages_wq
);
2529 queue_work_on(cpu
, mm_percpu_wq
, work
);
2531 for_each_cpu(cpu
, &cpus_with_pcps
)
2532 flush_work(per_cpu_ptr(&pcpu_drain
, cpu
));
2534 mutex_unlock(&pcpu_drain_mutex
);
2537 #ifdef CONFIG_HIBERNATION
2540 * Touch the watchdog for every WD_PAGE_COUNT pages.
2542 #define WD_PAGE_COUNT (128*1024)
2544 void mark_free_pages(struct zone
*zone
)
2546 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
2547 unsigned long flags
;
2548 unsigned int order
, t
;
2551 if (zone_is_empty(zone
))
2554 spin_lock_irqsave(&zone
->lock
, flags
);
2556 max_zone_pfn
= zone_end_pfn(zone
);
2557 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2558 if (pfn_valid(pfn
)) {
2559 page
= pfn_to_page(pfn
);
2561 if (!--page_count
) {
2562 touch_nmi_watchdog();
2563 page_count
= WD_PAGE_COUNT
;
2566 if (page_zone(page
) != zone
)
2569 if (!swsusp_page_is_forbidden(page
))
2570 swsusp_unset_page_free(page
);
2573 for_each_migratetype_order(order
, t
) {
2574 list_for_each_entry(page
,
2575 &zone
->free_area
[order
].free_list
[t
], lru
) {
2578 pfn
= page_to_pfn(page
);
2579 for (i
= 0; i
< (1UL << order
); i
++) {
2580 if (!--page_count
) {
2581 touch_nmi_watchdog();
2582 page_count
= WD_PAGE_COUNT
;
2584 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2588 spin_unlock_irqrestore(&zone
->lock
, flags
);
2590 #endif /* CONFIG_PM */
2593 * Free a 0-order page
2594 * cold == true ? free a cold page : free a hot page
2596 void free_hot_cold_page(struct page
*page
, bool cold
)
2598 struct zone
*zone
= page_zone(page
);
2599 struct per_cpu_pages
*pcp
;
2600 unsigned long flags
;
2601 unsigned long pfn
= page_to_pfn(page
);
2604 if (!free_pcp_prepare(page
))
2607 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2608 set_pcppage_migratetype(page
, migratetype
);
2609 local_irq_save(flags
);
2610 __count_vm_event(PGFREE
);
2613 * We only track unmovable, reclaimable and movable on pcp lists.
2614 * Free ISOLATE pages back to the allocator because they are being
2615 * offlined but treat HIGHATOMIC as movable pages so we can get those
2616 * areas back if necessary. Otherwise, we may have to free
2617 * excessively into the page allocator
2619 if (migratetype
>= MIGRATE_PCPTYPES
) {
2620 if (unlikely(is_migrate_isolate(migratetype
))) {
2621 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2624 migratetype
= MIGRATE_MOVABLE
;
2627 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2629 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2631 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2633 if (pcp
->count
>= pcp
->high
) {
2634 unsigned long batch
= READ_ONCE(pcp
->batch
);
2635 free_pcppages_bulk(zone
, batch
, pcp
);
2636 pcp
->count
-= batch
;
2640 local_irq_restore(flags
);
2644 * Free a list of 0-order pages
2646 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2648 struct page
*page
, *next
;
2650 list_for_each_entry_safe(page
, next
, list
, lru
) {
2651 trace_mm_page_free_batched(page
, cold
);
2652 free_hot_cold_page(page
, cold
);
2657 * split_page takes a non-compound higher-order page, and splits it into
2658 * n (1<<order) sub-pages: page[0..n]
2659 * Each sub-page must be freed individually.
2661 * Note: this is probably too low level an operation for use in drivers.
2662 * Please consult with lkml before using this in your driver.
2664 void split_page(struct page
*page
, unsigned int order
)
2668 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2669 VM_BUG_ON_PAGE(!page_count(page
), page
);
2671 #ifdef CONFIG_KMEMCHECK
2673 * Split shadow pages too, because free(page[0]) would
2674 * otherwise free the whole shadow.
2676 if (kmemcheck_page_is_tracked(page
))
2677 split_page(virt_to_page(page
[0].shadow
), order
);
2680 for (i
= 1; i
< (1 << order
); i
++)
2681 set_page_refcounted(page
+ i
);
2682 split_page_owner(page
, order
);
2684 EXPORT_SYMBOL_GPL(split_page
);
2686 int __isolate_free_page(struct page
*page
, unsigned int order
)
2688 unsigned long watermark
;
2692 BUG_ON(!PageBuddy(page
));
2694 zone
= page_zone(page
);
2695 mt
= get_pageblock_migratetype(page
);
2697 if (!is_migrate_isolate(mt
)) {
2699 * Obey watermarks as if the page was being allocated. We can
2700 * emulate a high-order watermark check with a raised order-0
2701 * watermark, because we already know our high-order page
2704 watermark
= min_wmark_pages(zone
) + (1UL << order
);
2705 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
2708 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2711 /* Remove page from free list */
2712 list_del(&page
->lru
);
2713 zone
->free_area
[order
].nr_free
--;
2714 rmv_page_order(page
);
2717 * Set the pageblock if the isolated page is at least half of a
2720 if (order
>= pageblock_order
- 1) {
2721 struct page
*endpage
= page
+ (1 << order
) - 1;
2722 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2723 int mt
= get_pageblock_migratetype(page
);
2724 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
2725 && !is_migrate_highatomic(mt
))
2726 set_pageblock_migratetype(page
,
2732 return 1UL << order
;
2736 * Update NUMA hit/miss statistics
2738 * Must be called with interrupts disabled.
2740 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
2743 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2745 if (z
->node
!= numa_node_id())
2746 local_stat
= NUMA_OTHER
;
2748 if (z
->node
== preferred_zone
->node
)
2749 __inc_zone_state(z
, NUMA_HIT
);
2751 __inc_zone_state(z
, NUMA_MISS
);
2752 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2754 __inc_zone_state(z
, local_stat
);
2758 /* Remove page from the per-cpu list, caller must protect the list */
2759 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
2760 bool cold
, struct per_cpu_pages
*pcp
,
2761 struct list_head
*list
)
2766 if (list_empty(list
)) {
2767 pcp
->count
+= rmqueue_bulk(zone
, 0,
2770 if (unlikely(list_empty(list
)))
2775 page
= list_last_entry(list
, struct page
, lru
);
2777 page
= list_first_entry(list
, struct page
, lru
);
2779 list_del(&page
->lru
);
2781 } while (check_new_pcp(page
));
2786 /* Lock and remove page from the per-cpu list */
2787 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
2788 struct zone
*zone
, unsigned int order
,
2789 gfp_t gfp_flags
, int migratetype
)
2791 struct per_cpu_pages
*pcp
;
2792 struct list_head
*list
;
2793 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2795 unsigned long flags
;
2797 local_irq_save(flags
);
2798 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2799 list
= &pcp
->lists
[migratetype
];
2800 page
= __rmqueue_pcplist(zone
, migratetype
, cold
, pcp
, list
);
2802 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2803 zone_statistics(preferred_zone
, zone
);
2805 local_irq_restore(flags
);
2810 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2813 struct page
*rmqueue(struct zone
*preferred_zone
,
2814 struct zone
*zone
, unsigned int order
,
2815 gfp_t gfp_flags
, unsigned int alloc_flags
,
2818 unsigned long flags
;
2821 if (likely(order
== 0)) {
2822 page
= rmqueue_pcplist(preferred_zone
, zone
, order
,
2823 gfp_flags
, migratetype
);
2828 * We most definitely don't want callers attempting to
2829 * allocate greater than order-1 page units with __GFP_NOFAIL.
2831 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2832 spin_lock_irqsave(&zone
->lock
, flags
);
2836 if (alloc_flags
& ALLOC_HARDER
) {
2837 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2839 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2842 page
= __rmqueue(zone
, order
, migratetype
);
2843 } while (page
&& check_new_pages(page
, order
));
2844 spin_unlock(&zone
->lock
);
2847 __mod_zone_freepage_state(zone
, -(1 << order
),
2848 get_pcppage_migratetype(page
));
2850 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2851 zone_statistics(preferred_zone
, zone
);
2852 local_irq_restore(flags
);
2855 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
2859 local_irq_restore(flags
);
2863 #ifdef CONFIG_FAIL_PAGE_ALLOC
2866 struct fault_attr attr
;
2868 bool ignore_gfp_highmem
;
2869 bool ignore_gfp_reclaim
;
2871 } fail_page_alloc
= {
2872 .attr
= FAULT_ATTR_INITIALIZER
,
2873 .ignore_gfp_reclaim
= true,
2874 .ignore_gfp_highmem
= true,
2878 static int __init
setup_fail_page_alloc(char *str
)
2880 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2882 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2884 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2886 if (order
< fail_page_alloc
.min_order
)
2888 if (gfp_mask
& __GFP_NOFAIL
)
2890 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2892 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2893 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2896 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2899 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2901 static int __init
fail_page_alloc_debugfs(void)
2903 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2906 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2907 &fail_page_alloc
.attr
);
2909 return PTR_ERR(dir
);
2911 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2912 &fail_page_alloc
.ignore_gfp_reclaim
))
2914 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2915 &fail_page_alloc
.ignore_gfp_highmem
))
2917 if (!debugfs_create_u32("min-order", mode
, dir
,
2918 &fail_page_alloc
.min_order
))
2923 debugfs_remove_recursive(dir
);
2928 late_initcall(fail_page_alloc_debugfs
);
2930 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2932 #else /* CONFIG_FAIL_PAGE_ALLOC */
2934 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2939 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2942 * Return true if free base pages are above 'mark'. For high-order checks it
2943 * will return true of the order-0 watermark is reached and there is at least
2944 * one free page of a suitable size. Checking now avoids taking the zone lock
2945 * to check in the allocation paths if no pages are free.
2947 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2948 int classzone_idx
, unsigned int alloc_flags
,
2953 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2955 /* free_pages may go negative - that's OK */
2956 free_pages
-= (1 << order
) - 1;
2958 if (alloc_flags
& ALLOC_HIGH
)
2962 * If the caller does not have rights to ALLOC_HARDER then subtract
2963 * the high-atomic reserves. This will over-estimate the size of the
2964 * atomic reserve but it avoids a search.
2966 if (likely(!alloc_harder
))
2967 free_pages
-= z
->nr_reserved_highatomic
;
2972 /* If allocation can't use CMA areas don't use free CMA pages */
2973 if (!(alloc_flags
& ALLOC_CMA
))
2974 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2978 * Check watermarks for an order-0 allocation request. If these
2979 * are not met, then a high-order request also cannot go ahead
2980 * even if a suitable page happened to be free.
2982 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2985 /* If this is an order-0 request then the watermark is fine */
2989 /* For a high-order request, check at least one suitable page is free */
2990 for (o
= order
; o
< MAX_ORDER
; o
++) {
2991 struct free_area
*area
= &z
->free_area
[o
];
3000 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3001 if (!list_empty(&area
->free_list
[mt
]))
3006 if ((alloc_flags
& ALLOC_CMA
) &&
3007 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
3015 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3016 int classzone_idx
, unsigned int alloc_flags
)
3018 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3019 zone_page_state(z
, NR_FREE_PAGES
));
3022 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3023 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
3025 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3029 /* If allocation can't use CMA areas don't use free CMA pages */
3030 if (!(alloc_flags
& ALLOC_CMA
))
3031 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3035 * Fast check for order-0 only. If this fails then the reserves
3036 * need to be calculated. There is a corner case where the check
3037 * passes but only the high-order atomic reserve are free. If
3038 * the caller is !atomic then it'll uselessly search the free
3039 * list. That corner case is then slower but it is harmless.
3041 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
3044 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3048 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3049 unsigned long mark
, int classzone_idx
)
3051 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3053 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3054 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3056 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
3061 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3063 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3066 #else /* CONFIG_NUMA */
3067 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3071 #endif /* CONFIG_NUMA */
3074 * get_page_from_freelist goes through the zonelist trying to allocate
3077 static struct page
*
3078 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3079 const struct alloc_context
*ac
)
3081 struct zoneref
*z
= ac
->preferred_zoneref
;
3083 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3086 * Scan zonelist, looking for a zone with enough free.
3087 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3089 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3094 if (cpusets_enabled() &&
3095 (alloc_flags
& ALLOC_CPUSET
) &&
3096 !__cpuset_zone_allowed(zone
, gfp_mask
))
3099 * When allocating a page cache page for writing, we
3100 * want to get it from a node that is within its dirty
3101 * limit, such that no single node holds more than its
3102 * proportional share of globally allowed dirty pages.
3103 * The dirty limits take into account the node's
3104 * lowmem reserves and high watermark so that kswapd
3105 * should be able to balance it without having to
3106 * write pages from its LRU list.
3108 * XXX: For now, allow allocations to potentially
3109 * exceed the per-node dirty limit in the slowpath
3110 * (spread_dirty_pages unset) before going into reclaim,
3111 * which is important when on a NUMA setup the allowed
3112 * nodes are together not big enough to reach the
3113 * global limit. The proper fix for these situations
3114 * will require awareness of nodes in the
3115 * dirty-throttling and the flusher threads.
3117 if (ac
->spread_dirty_pages
) {
3118 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3121 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3122 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3127 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
3128 if (!zone_watermark_fast(zone
, order
, mark
,
3129 ac_classzone_idx(ac
), alloc_flags
)) {
3132 /* Checked here to keep the fast path fast */
3133 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3134 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3137 if (node_reclaim_mode
== 0 ||
3138 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3141 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3143 case NODE_RECLAIM_NOSCAN
:
3146 case NODE_RECLAIM_FULL
:
3147 /* scanned but unreclaimable */
3150 /* did we reclaim enough */
3151 if (zone_watermark_ok(zone
, order
, mark
,
3152 ac_classzone_idx(ac
), alloc_flags
))
3160 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3161 gfp_mask
, alloc_flags
, ac
->migratetype
);
3163 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3166 * If this is a high-order atomic allocation then check
3167 * if the pageblock should be reserved for the future
3169 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3170 reserve_highatomic_pageblock(page
, zone
, order
);
3180 * Large machines with many possible nodes should not always dump per-node
3181 * meminfo in irq context.
3183 static inline bool should_suppress_show_mem(void)
3188 ret
= in_interrupt();
3193 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3195 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3196 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3198 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs
))
3202 * This documents exceptions given to allocations in certain
3203 * contexts that are allowed to allocate outside current's set
3206 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3207 if (test_thread_flag(TIF_MEMDIE
) ||
3208 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3209 filter
&= ~SHOW_MEM_FILTER_NODES
;
3210 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3211 filter
&= ~SHOW_MEM_FILTER_NODES
;
3213 show_mem(filter
, nodemask
);
3216 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3218 struct va_format vaf
;
3220 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3221 DEFAULT_RATELIMIT_BURST
);
3223 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3226 pr_warn("%s: ", current
->comm
);
3228 va_start(args
, fmt
);
3231 pr_cont("%pV", &vaf
);
3234 pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask
, &gfp_mask
);
3236 pr_cont("%*pbl\n", nodemask_pr_args(nodemask
));
3238 pr_cont("(null)\n");
3240 cpuset_print_current_mems_allowed();
3243 warn_alloc_show_mem(gfp_mask
, nodemask
);
3246 static inline struct page
*
3247 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3248 unsigned int alloc_flags
,
3249 const struct alloc_context
*ac
)
3253 page
= get_page_from_freelist(gfp_mask
, order
,
3254 alloc_flags
|ALLOC_CPUSET
, ac
);
3256 * fallback to ignore cpuset restriction if our nodes
3260 page
= get_page_from_freelist(gfp_mask
, order
,
3266 static inline struct page
*
3267 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3268 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3270 struct oom_control oc
= {
3271 .zonelist
= ac
->zonelist
,
3272 .nodemask
= ac
->nodemask
,
3274 .gfp_mask
= gfp_mask
,
3279 *did_some_progress
= 0;
3282 * Acquire the oom lock. If that fails, somebody else is
3283 * making progress for us.
3285 if (!mutex_trylock(&oom_lock
)) {
3286 *did_some_progress
= 1;
3287 schedule_timeout_uninterruptible(1);
3292 * Go through the zonelist yet one more time, keep very high watermark
3293 * here, this is only to catch a parallel oom killing, we must fail if
3294 * we're still under heavy pressure. But make sure that this reclaim
3295 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3296 * allocation which will never fail due to oom_lock already held.
3298 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
3299 ~__GFP_DIRECT_RECLAIM
, order
,
3300 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3304 /* Coredumps can quickly deplete all memory reserves */
3305 if (current
->flags
& PF_DUMPCORE
)
3307 /* The OOM killer will not help higher order allocs */
3308 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3311 * We have already exhausted all our reclaim opportunities without any
3312 * success so it is time to admit defeat. We will skip the OOM killer
3313 * because it is very likely that the caller has a more reasonable
3314 * fallback than shooting a random task.
3316 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
3318 /* The OOM killer does not needlessly kill tasks for lowmem */
3319 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3321 if (pm_suspended_storage())
3324 * XXX: GFP_NOFS allocations should rather fail than rely on
3325 * other request to make a forward progress.
3326 * We are in an unfortunate situation where out_of_memory cannot
3327 * do much for this context but let's try it to at least get
3328 * access to memory reserved if the current task is killed (see
3329 * out_of_memory). Once filesystems are ready to handle allocation
3330 * failures more gracefully we should just bail out here.
3333 /* The OOM killer may not free memory on a specific node */
3334 if (gfp_mask
& __GFP_THISNODE
)
3337 /* Exhausted what can be done so it's blamo time */
3338 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3339 *did_some_progress
= 1;
3342 * Help non-failing allocations by giving them access to memory
3345 if (gfp_mask
& __GFP_NOFAIL
)
3346 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3347 ALLOC_NO_WATERMARKS
, ac
);
3350 mutex_unlock(&oom_lock
);
3355 * Maximum number of compaction retries wit a progress before OOM
3356 * killer is consider as the only way to move forward.
3358 #define MAX_COMPACT_RETRIES 16
3360 #ifdef CONFIG_COMPACTION
3361 /* Try memory compaction for high-order allocations before reclaim */
3362 static struct page
*
3363 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3364 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3365 enum compact_priority prio
, enum compact_result
*compact_result
)
3368 unsigned int noreclaim_flag
;
3373 noreclaim_flag
= memalloc_noreclaim_save();
3374 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3376 memalloc_noreclaim_restore(noreclaim_flag
);
3378 if (*compact_result
<= COMPACT_INACTIVE
)
3382 * At least in one zone compaction wasn't deferred or skipped, so let's
3383 * count a compaction stall
3385 count_vm_event(COMPACTSTALL
);
3387 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3390 struct zone
*zone
= page_zone(page
);
3392 zone
->compact_blockskip_flush
= false;
3393 compaction_defer_reset(zone
, order
, true);
3394 count_vm_event(COMPACTSUCCESS
);
3399 * It's bad if compaction run occurs and fails. The most likely reason
3400 * is that pages exist, but not enough to satisfy watermarks.
3402 count_vm_event(COMPACTFAIL
);
3410 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3411 enum compact_result compact_result
,
3412 enum compact_priority
*compact_priority
,
3413 int *compaction_retries
)
3415 int max_retries
= MAX_COMPACT_RETRIES
;
3418 int retries
= *compaction_retries
;
3419 enum compact_priority priority
= *compact_priority
;
3424 if (compaction_made_progress(compact_result
))
3425 (*compaction_retries
)++;
3428 * compaction considers all the zone as desperately out of memory
3429 * so it doesn't really make much sense to retry except when the
3430 * failure could be caused by insufficient priority
3432 if (compaction_failed(compact_result
))
3433 goto check_priority
;
3436 * make sure the compaction wasn't deferred or didn't bail out early
3437 * due to locks contention before we declare that we should give up.
3438 * But do not retry if the given zonelist is not suitable for
3441 if (compaction_withdrawn(compact_result
)) {
3442 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3447 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3448 * costly ones because they are de facto nofail and invoke OOM
3449 * killer to move on while costly can fail and users are ready
3450 * to cope with that. 1/4 retries is rather arbitrary but we
3451 * would need much more detailed feedback from compaction to
3452 * make a better decision.
3454 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3456 if (*compaction_retries
<= max_retries
) {
3462 * Make sure there are attempts at the highest priority if we exhausted
3463 * all retries or failed at the lower priorities.
3466 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3467 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3469 if (*compact_priority
> min_priority
) {
3470 (*compact_priority
)--;
3471 *compaction_retries
= 0;
3475 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3479 static inline struct page
*
3480 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3481 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3482 enum compact_priority prio
, enum compact_result
*compact_result
)
3484 *compact_result
= COMPACT_SKIPPED
;
3489 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3490 enum compact_result compact_result
,
3491 enum compact_priority
*compact_priority
,
3492 int *compaction_retries
)
3497 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3501 * There are setups with compaction disabled which would prefer to loop
3502 * inside the allocator rather than hit the oom killer prematurely.
3503 * Let's give them a good hope and keep retrying while the order-0
3504 * watermarks are OK.
3506 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3508 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3509 ac_classzone_idx(ac
), alloc_flags
))
3514 #endif /* CONFIG_COMPACTION */
3516 /* Perform direct synchronous page reclaim */
3518 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3519 const struct alloc_context
*ac
)
3521 struct reclaim_state reclaim_state
;
3523 unsigned int noreclaim_flag
;
3527 /* We now go into synchronous reclaim */
3528 cpuset_memory_pressure_bump();
3529 noreclaim_flag
= memalloc_noreclaim_save();
3530 lockdep_set_current_reclaim_state(gfp_mask
);
3531 reclaim_state
.reclaimed_slab
= 0;
3532 current
->reclaim_state
= &reclaim_state
;
3534 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3537 current
->reclaim_state
= NULL
;
3538 lockdep_clear_current_reclaim_state();
3539 memalloc_noreclaim_restore(noreclaim_flag
);
3546 /* The really slow allocator path where we enter direct reclaim */
3547 static inline struct page
*
3548 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3549 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3550 unsigned long *did_some_progress
)
3552 struct page
*page
= NULL
;
3553 bool drained
= false;
3555 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3556 if (unlikely(!(*did_some_progress
)))
3560 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3563 * If an allocation failed after direct reclaim, it could be because
3564 * pages are pinned on the per-cpu lists or in high alloc reserves.
3565 * Shrink them them and try again
3567 if (!page
&& !drained
) {
3568 unreserve_highatomic_pageblock(ac
, false);
3569 drain_all_pages(NULL
);
3577 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3581 pg_data_t
*last_pgdat
= NULL
;
3583 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3584 ac
->high_zoneidx
, ac
->nodemask
) {
3585 if (last_pgdat
!= zone
->zone_pgdat
)
3586 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3587 last_pgdat
= zone
->zone_pgdat
;
3591 static inline unsigned int
3592 gfp_to_alloc_flags(gfp_t gfp_mask
)
3594 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3596 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3597 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3600 * The caller may dip into page reserves a bit more if the caller
3601 * cannot run direct reclaim, or if the caller has realtime scheduling
3602 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3603 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3605 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3607 if (gfp_mask
& __GFP_ATOMIC
) {
3609 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3610 * if it can't schedule.
3612 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3613 alloc_flags
|= ALLOC_HARDER
;
3615 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3616 * comment for __cpuset_node_allowed().
3618 alloc_flags
&= ~ALLOC_CPUSET
;
3619 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3620 alloc_flags
|= ALLOC_HARDER
;
3623 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3624 alloc_flags
|= ALLOC_CMA
;
3629 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3631 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3634 if (gfp_mask
& __GFP_MEMALLOC
)
3636 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3638 if (!in_interrupt() &&
3639 ((current
->flags
& PF_MEMALLOC
) ||
3640 unlikely(test_thread_flag(TIF_MEMDIE
))))
3647 * Checks whether it makes sense to retry the reclaim to make a forward progress
3648 * for the given allocation request.
3650 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3651 * without success, or when we couldn't even meet the watermark if we
3652 * reclaimed all remaining pages on the LRU lists.
3654 * Returns true if a retry is viable or false to enter the oom path.
3657 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3658 struct alloc_context
*ac
, int alloc_flags
,
3659 bool did_some_progress
, int *no_progress_loops
)
3665 * Costly allocations might have made a progress but this doesn't mean
3666 * their order will become available due to high fragmentation so
3667 * always increment the no progress counter for them
3669 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3670 *no_progress_loops
= 0;
3672 (*no_progress_loops
)++;
3675 * Make sure we converge to OOM if we cannot make any progress
3676 * several times in the row.
3678 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
3679 /* Before OOM, exhaust highatomic_reserve */
3680 return unreserve_highatomic_pageblock(ac
, true);
3684 * Keep reclaiming pages while there is a chance this will lead
3685 * somewhere. If none of the target zones can satisfy our allocation
3686 * request even if all reclaimable pages are considered then we are
3687 * screwed and have to go OOM.
3689 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3691 unsigned long available
;
3692 unsigned long reclaimable
;
3693 unsigned long min_wmark
= min_wmark_pages(zone
);
3696 available
= reclaimable
= zone_reclaimable_pages(zone
);
3697 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3700 * Would the allocation succeed if we reclaimed all
3701 * reclaimable pages?
3703 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
3704 ac_classzone_idx(ac
), alloc_flags
, available
);
3705 trace_reclaim_retry_zone(z
, order
, reclaimable
,
3706 available
, min_wmark
, *no_progress_loops
, wmark
);
3709 * If we didn't make any progress and have a lot of
3710 * dirty + writeback pages then we should wait for
3711 * an IO to complete to slow down the reclaim and
3712 * prevent from pre mature OOM
3714 if (!did_some_progress
) {
3715 unsigned long write_pending
;
3717 write_pending
= zone_page_state_snapshot(zone
,
3718 NR_ZONE_WRITE_PENDING
);
3720 if (2 * write_pending
> reclaimable
) {
3721 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3727 * Memory allocation/reclaim might be called from a WQ
3728 * context and the current implementation of the WQ
3729 * concurrency control doesn't recognize that
3730 * a particular WQ is congested if the worker thread is
3731 * looping without ever sleeping. Therefore we have to
3732 * do a short sleep here rather than calling
3735 if (current
->flags
& PF_WQ_WORKER
)
3736 schedule_timeout_uninterruptible(1);
3748 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
3751 * It's possible that cpuset's mems_allowed and the nodemask from
3752 * mempolicy don't intersect. This should be normally dealt with by
3753 * policy_nodemask(), but it's possible to race with cpuset update in
3754 * such a way the check therein was true, and then it became false
3755 * before we got our cpuset_mems_cookie here.
3756 * This assumes that for all allocations, ac->nodemask can come only
3757 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
3758 * when it does not intersect with the cpuset restrictions) or the
3759 * caller can deal with a violated nodemask.
3761 if (cpusets_enabled() && ac
->nodemask
&&
3762 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
3763 ac
->nodemask
= NULL
;
3768 * When updating a task's mems_allowed or mempolicy nodemask, it is
3769 * possible to race with parallel threads in such a way that our
3770 * allocation can fail while the mask is being updated. If we are about
3771 * to fail, check if the cpuset changed during allocation and if so,
3774 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3780 static inline struct page
*
3781 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3782 struct alloc_context
*ac
)
3784 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3785 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
3786 struct page
*page
= NULL
;
3787 unsigned int alloc_flags
;
3788 unsigned long did_some_progress
;
3789 enum compact_priority compact_priority
;
3790 enum compact_result compact_result
;
3791 int compaction_retries
;
3792 int no_progress_loops
;
3793 unsigned long alloc_start
= jiffies
;
3794 unsigned int stall_timeout
= 10 * HZ
;
3795 unsigned int cpuset_mems_cookie
;
3798 * In the slowpath, we sanity check order to avoid ever trying to
3799 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3800 * be using allocators in order of preference for an area that is
3803 if (order
>= MAX_ORDER
) {
3804 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3809 * We also sanity check to catch abuse of atomic reserves being used by
3810 * callers that are not in atomic context.
3812 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3813 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3814 gfp_mask
&= ~__GFP_ATOMIC
;
3817 compaction_retries
= 0;
3818 no_progress_loops
= 0;
3819 compact_priority
= DEF_COMPACT_PRIORITY
;
3820 cpuset_mems_cookie
= read_mems_allowed_begin();
3823 * The fast path uses conservative alloc_flags to succeed only until
3824 * kswapd needs to be woken up, and to avoid the cost of setting up
3825 * alloc_flags precisely. So we do that now.
3827 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3830 * We need to recalculate the starting point for the zonelist iterator
3831 * because we might have used different nodemask in the fast path, or
3832 * there was a cpuset modification and we are retrying - otherwise we
3833 * could end up iterating over non-eligible zones endlessly.
3835 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3836 ac
->high_zoneidx
, ac
->nodemask
);
3837 if (!ac
->preferred_zoneref
->zone
)
3840 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3841 wake_all_kswapds(order
, ac
);
3844 * The adjusted alloc_flags might result in immediate success, so try
3847 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3852 * For costly allocations, try direct compaction first, as it's likely
3853 * that we have enough base pages and don't need to reclaim. For non-
3854 * movable high-order allocations, do that as well, as compaction will
3855 * try prevent permanent fragmentation by migrating from blocks of the
3857 * Don't try this for allocations that are allowed to ignore
3858 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
3860 if (can_direct_reclaim
&&
3862 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
3863 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
3864 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
3866 INIT_COMPACT_PRIORITY
,
3872 * Checks for costly allocations with __GFP_NORETRY, which
3873 * includes THP page fault allocations
3875 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
3877 * If compaction is deferred for high-order allocations,
3878 * it is because sync compaction recently failed. If
3879 * this is the case and the caller requested a THP
3880 * allocation, we do not want to heavily disrupt the
3881 * system, so we fail the allocation instead of entering
3884 if (compact_result
== COMPACT_DEFERRED
)
3888 * Looks like reclaim/compaction is worth trying, but
3889 * sync compaction could be very expensive, so keep
3890 * using async compaction.
3892 compact_priority
= INIT_COMPACT_PRIORITY
;
3897 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3898 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3899 wake_all_kswapds(order
, ac
);
3901 if (gfp_pfmemalloc_allowed(gfp_mask
))
3902 alloc_flags
= ALLOC_NO_WATERMARKS
;
3905 * Reset the zonelist iterators if memory policies can be ignored.
3906 * These allocations are high priority and system rather than user
3909 if (!(alloc_flags
& ALLOC_CPUSET
) || (alloc_flags
& ALLOC_NO_WATERMARKS
)) {
3910 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3911 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3912 ac
->high_zoneidx
, ac
->nodemask
);
3915 /* Attempt with potentially adjusted zonelist and alloc_flags */
3916 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3920 /* Caller is not willing to reclaim, we can't balance anything */
3921 if (!can_direct_reclaim
)
3924 /* Make sure we know about allocations which stall for too long */
3925 if (time_after(jiffies
, alloc_start
+ stall_timeout
)) {
3926 warn_alloc(gfp_mask
& ~__GFP_NOWARN
, ac
->nodemask
,
3927 "page allocation stalls for %ums, order:%u",
3928 jiffies_to_msecs(jiffies
-alloc_start
), order
);
3929 stall_timeout
+= 10 * HZ
;
3932 /* Avoid recursion of direct reclaim */
3933 if (current
->flags
& PF_MEMALLOC
)
3936 /* Try direct reclaim and then allocating */
3937 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3938 &did_some_progress
);
3942 /* Try direct compaction and then allocating */
3943 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3944 compact_priority
, &compact_result
);
3948 /* Do not loop if specifically requested */
3949 if (gfp_mask
& __GFP_NORETRY
)
3953 * Do not retry costly high order allocations unless they are
3954 * __GFP_RETRY_MAYFAIL
3956 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
3959 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3960 did_some_progress
> 0, &no_progress_loops
))
3964 * It doesn't make any sense to retry for the compaction if the order-0
3965 * reclaim is not able to make any progress because the current
3966 * implementation of the compaction depends on the sufficient amount
3967 * of free memory (see __compaction_suitable)
3969 if (did_some_progress
> 0 &&
3970 should_compact_retry(ac
, order
, alloc_flags
,
3971 compact_result
, &compact_priority
,
3972 &compaction_retries
))
3976 /* Deal with possible cpuset update races before we start OOM killing */
3977 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
3980 /* Reclaim has failed us, start killing things */
3981 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3985 /* Avoid allocations with no watermarks from looping endlessly */
3986 if (test_thread_flag(TIF_MEMDIE
) &&
3987 (alloc_flags
== ALLOC_NO_WATERMARKS
||
3988 (gfp_mask
& __GFP_NOMEMALLOC
)))
3991 /* Retry as long as the OOM killer is making progress */
3992 if (did_some_progress
) {
3993 no_progress_loops
= 0;
3998 /* Deal with possible cpuset update races before we fail */
3999 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4003 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4006 if (gfp_mask
& __GFP_NOFAIL
) {
4008 * All existing users of the __GFP_NOFAIL are blockable, so warn
4009 * of any new users that actually require GFP_NOWAIT
4011 if (WARN_ON_ONCE(!can_direct_reclaim
))
4015 * PF_MEMALLOC request from this context is rather bizarre
4016 * because we cannot reclaim anything and only can loop waiting
4017 * for somebody to do a work for us
4019 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4022 * non failing costly orders are a hard requirement which we
4023 * are not prepared for much so let's warn about these users
4024 * so that we can identify them and convert them to something
4027 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4030 * Help non-failing allocations by giving them access to memory
4031 * reserves but do not use ALLOC_NO_WATERMARKS because this
4032 * could deplete whole memory reserves which would just make
4033 * the situation worse
4035 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4043 warn_alloc(gfp_mask
, ac
->nodemask
,
4044 "page allocation failure: order:%u", order
);
4049 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4050 int preferred_nid
, nodemask_t
*nodemask
,
4051 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4052 unsigned int *alloc_flags
)
4054 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
4055 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4056 ac
->nodemask
= nodemask
;
4057 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
4059 if (cpusets_enabled()) {
4060 *alloc_mask
|= __GFP_HARDWALL
;
4062 ac
->nodemask
= &cpuset_current_mems_allowed
;
4064 *alloc_flags
|= ALLOC_CPUSET
;
4067 lockdep_trace_alloc(gfp_mask
);
4069 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4071 if (should_fail_alloc_page(gfp_mask
, order
))
4074 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
4075 *alloc_flags
|= ALLOC_CMA
;
4080 /* Determine whether to spread dirty pages and what the first usable zone */
4081 static inline void finalise_ac(gfp_t gfp_mask
,
4082 unsigned int order
, struct alloc_context
*ac
)
4084 /* Dirty zone balancing only done in the fast path */
4085 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4088 * The preferred zone is used for statistics but crucially it is
4089 * also used as the starting point for the zonelist iterator. It
4090 * may get reset for allocations that ignore memory policies.
4092 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4093 ac
->high_zoneidx
, ac
->nodemask
);
4097 * This is the 'heart' of the zoned buddy allocator.
4100 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4101 nodemask_t
*nodemask
)
4104 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4105 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
4106 struct alloc_context ac
= { };
4108 gfp_mask
&= gfp_allowed_mask
;
4109 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4112 finalise_ac(gfp_mask
, order
, &ac
);
4114 /* First allocation attempt */
4115 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4120 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4121 * resp. GFP_NOIO which has to be inherited for all allocation requests
4122 * from a particular context which has been marked by
4123 * memalloc_no{fs,io}_{save,restore}.
4125 alloc_mask
= current_gfp_context(gfp_mask
);
4126 ac
.spread_dirty_pages
= false;
4129 * Restore the original nodemask if it was potentially replaced with
4130 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4132 if (unlikely(ac
.nodemask
!= nodemask
))
4133 ac
.nodemask
= nodemask
;
4135 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4138 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4139 unlikely(memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
4140 __free_pages(page
, order
);
4144 if (kmemcheck_enabled
&& page
)
4145 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
4147 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4151 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4154 * Common helper functions.
4156 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4161 * __get_free_pages() returns a 32-bit address, which cannot represent
4164 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
4166 page
= alloc_pages(gfp_mask
, order
);
4169 return (unsigned long) page_address(page
);
4171 EXPORT_SYMBOL(__get_free_pages
);
4173 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4175 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4177 EXPORT_SYMBOL(get_zeroed_page
);
4179 void __free_pages(struct page
*page
, unsigned int order
)
4181 if (put_page_testzero(page
)) {
4183 free_hot_cold_page(page
, false);
4185 __free_pages_ok(page
, order
);
4189 EXPORT_SYMBOL(__free_pages
);
4191 void free_pages(unsigned long addr
, unsigned int order
)
4194 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4195 __free_pages(virt_to_page((void *)addr
), order
);
4199 EXPORT_SYMBOL(free_pages
);
4203 * An arbitrary-length arbitrary-offset area of memory which resides
4204 * within a 0 or higher order page. Multiple fragments within that page
4205 * are individually refcounted, in the page's reference counter.
4207 * The page_frag functions below provide a simple allocation framework for
4208 * page fragments. This is used by the network stack and network device
4209 * drivers to provide a backing region of memory for use as either an
4210 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4212 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4215 struct page
*page
= NULL
;
4216 gfp_t gfp
= gfp_mask
;
4218 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4219 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4221 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4222 PAGE_FRAG_CACHE_MAX_ORDER
);
4223 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4225 if (unlikely(!page
))
4226 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4228 nc
->va
= page
? page_address(page
) : NULL
;
4233 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4235 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4237 if (page_ref_sub_and_test(page
, count
)) {
4238 unsigned int order
= compound_order(page
);
4241 free_hot_cold_page(page
, false);
4243 __free_pages_ok(page
, order
);
4246 EXPORT_SYMBOL(__page_frag_cache_drain
);
4248 void *page_frag_alloc(struct page_frag_cache
*nc
,
4249 unsigned int fragsz
, gfp_t gfp_mask
)
4251 unsigned int size
= PAGE_SIZE
;
4255 if (unlikely(!nc
->va
)) {
4257 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4261 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4262 /* if size can vary use size else just use PAGE_SIZE */
4265 /* Even if we own the page, we do not use atomic_set().
4266 * This would break get_page_unless_zero() users.
4268 page_ref_add(page
, size
- 1);
4270 /* reset page count bias and offset to start of new frag */
4271 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4272 nc
->pagecnt_bias
= size
;
4276 offset
= nc
->offset
- fragsz
;
4277 if (unlikely(offset
< 0)) {
4278 page
= virt_to_page(nc
->va
);
4280 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4283 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4284 /* if size can vary use size else just use PAGE_SIZE */
4287 /* OK, page count is 0, we can safely set it */
4288 set_page_count(page
, size
);
4290 /* reset page count bias and offset to start of new frag */
4291 nc
->pagecnt_bias
= size
;
4292 offset
= size
- fragsz
;
4296 nc
->offset
= offset
;
4298 return nc
->va
+ offset
;
4300 EXPORT_SYMBOL(page_frag_alloc
);
4303 * Frees a page fragment allocated out of either a compound or order 0 page.
4305 void page_frag_free(void *addr
)
4307 struct page
*page
= virt_to_head_page(addr
);
4309 if (unlikely(put_page_testzero(page
)))
4310 __free_pages_ok(page
, compound_order(page
));
4312 EXPORT_SYMBOL(page_frag_free
);
4314 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4318 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4319 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4321 split_page(virt_to_page((void *)addr
), order
);
4322 while (used
< alloc_end
) {
4327 return (void *)addr
;
4331 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4332 * @size: the number of bytes to allocate
4333 * @gfp_mask: GFP flags for the allocation
4335 * This function is similar to alloc_pages(), except that it allocates the
4336 * minimum number of pages to satisfy the request. alloc_pages() can only
4337 * allocate memory in power-of-two pages.
4339 * This function is also limited by MAX_ORDER.
4341 * Memory allocated by this function must be released by free_pages_exact().
4343 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4345 unsigned int order
= get_order(size
);
4348 addr
= __get_free_pages(gfp_mask
, order
);
4349 return make_alloc_exact(addr
, order
, size
);
4351 EXPORT_SYMBOL(alloc_pages_exact
);
4354 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4356 * @nid: the preferred node ID where memory should be allocated
4357 * @size: the number of bytes to allocate
4358 * @gfp_mask: GFP flags for the allocation
4360 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4363 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4365 unsigned int order
= get_order(size
);
4366 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4369 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4373 * free_pages_exact - release memory allocated via alloc_pages_exact()
4374 * @virt: the value returned by alloc_pages_exact.
4375 * @size: size of allocation, same value as passed to alloc_pages_exact().
4377 * Release the memory allocated by a previous call to alloc_pages_exact.
4379 void free_pages_exact(void *virt
, size_t size
)
4381 unsigned long addr
= (unsigned long)virt
;
4382 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4384 while (addr
< end
) {
4389 EXPORT_SYMBOL(free_pages_exact
);
4392 * nr_free_zone_pages - count number of pages beyond high watermark
4393 * @offset: The zone index of the highest zone
4395 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4396 * high watermark within all zones at or below a given zone index. For each
4397 * zone, the number of pages is calculated as:
4399 * nr_free_zone_pages = managed_pages - high_pages
4401 static unsigned long nr_free_zone_pages(int offset
)
4406 /* Just pick one node, since fallback list is circular */
4407 unsigned long sum
= 0;
4409 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4411 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4412 unsigned long size
= zone
->managed_pages
;
4413 unsigned long high
= high_wmark_pages(zone
);
4422 * nr_free_buffer_pages - count number of pages beyond high watermark
4424 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4425 * watermark within ZONE_DMA and ZONE_NORMAL.
4427 unsigned long nr_free_buffer_pages(void)
4429 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4431 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4434 * nr_free_pagecache_pages - count number of pages beyond high watermark
4436 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4437 * high watermark within all zones.
4439 unsigned long nr_free_pagecache_pages(void)
4441 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4444 static inline void show_node(struct zone
*zone
)
4446 if (IS_ENABLED(CONFIG_NUMA
))
4447 printk("Node %d ", zone_to_nid(zone
));
4450 long si_mem_available(void)
4453 unsigned long pagecache
;
4454 unsigned long wmark_low
= 0;
4455 unsigned long pages
[NR_LRU_LISTS
];
4459 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4460 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
4463 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4466 * Estimate the amount of memory available for userspace allocations,
4467 * without causing swapping.
4469 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4472 * Not all the page cache can be freed, otherwise the system will
4473 * start swapping. Assume at least half of the page cache, or the
4474 * low watermark worth of cache, needs to stay.
4476 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4477 pagecache
-= min(pagecache
/ 2, wmark_low
);
4478 available
+= pagecache
;
4481 * Part of the reclaimable slab consists of items that are in use,
4482 * and cannot be freed. Cap this estimate at the low watermark.
4484 available
+= global_node_page_state(NR_SLAB_RECLAIMABLE
) -
4485 min(global_node_page_state(NR_SLAB_RECLAIMABLE
) / 2,
4492 EXPORT_SYMBOL_GPL(si_mem_available
);
4494 void si_meminfo(struct sysinfo
*val
)
4496 val
->totalram
= totalram_pages
;
4497 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4498 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4499 val
->bufferram
= nr_blockdev_pages();
4500 val
->totalhigh
= totalhigh_pages
;
4501 val
->freehigh
= nr_free_highpages();
4502 val
->mem_unit
= PAGE_SIZE
;
4505 EXPORT_SYMBOL(si_meminfo
);
4508 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4510 int zone_type
; /* needs to be signed */
4511 unsigned long managed_pages
= 0;
4512 unsigned long managed_highpages
= 0;
4513 unsigned long free_highpages
= 0;
4514 pg_data_t
*pgdat
= NODE_DATA(nid
);
4516 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4517 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4518 val
->totalram
= managed_pages
;
4519 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4520 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4521 #ifdef CONFIG_HIGHMEM
4522 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4523 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4525 if (is_highmem(zone
)) {
4526 managed_highpages
+= zone
->managed_pages
;
4527 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4530 val
->totalhigh
= managed_highpages
;
4531 val
->freehigh
= free_highpages
;
4533 val
->totalhigh
= managed_highpages
;
4534 val
->freehigh
= free_highpages
;
4536 val
->mem_unit
= PAGE_SIZE
;
4541 * Determine whether the node should be displayed or not, depending on whether
4542 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4544 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
4546 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4550 * no node mask - aka implicit memory numa policy. Do not bother with
4551 * the synchronization - read_mems_allowed_begin - because we do not
4552 * have to be precise here.
4555 nodemask
= &cpuset_current_mems_allowed
;
4557 return !node_isset(nid
, *nodemask
);
4560 #define K(x) ((x) << (PAGE_SHIFT-10))
4562 static void show_migration_types(unsigned char type
)
4564 static const char types
[MIGRATE_TYPES
] = {
4565 [MIGRATE_UNMOVABLE
] = 'U',
4566 [MIGRATE_MOVABLE
] = 'M',
4567 [MIGRATE_RECLAIMABLE
] = 'E',
4568 [MIGRATE_HIGHATOMIC
] = 'H',
4570 [MIGRATE_CMA
] = 'C',
4572 #ifdef CONFIG_MEMORY_ISOLATION
4573 [MIGRATE_ISOLATE
] = 'I',
4576 char tmp
[MIGRATE_TYPES
+ 1];
4580 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4581 if (type
& (1 << i
))
4586 printk(KERN_CONT
"(%s) ", tmp
);
4590 * Show free area list (used inside shift_scroll-lock stuff)
4591 * We also calculate the percentage fragmentation. We do this by counting the
4592 * memory on each free list with the exception of the first item on the list.
4595 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4598 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
4600 unsigned long free_pcp
= 0;
4605 for_each_populated_zone(zone
) {
4606 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4609 for_each_online_cpu(cpu
)
4610 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4613 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4614 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4615 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4616 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4617 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4618 " free:%lu free_pcp:%lu free_cma:%lu\n",
4619 global_node_page_state(NR_ACTIVE_ANON
),
4620 global_node_page_state(NR_INACTIVE_ANON
),
4621 global_node_page_state(NR_ISOLATED_ANON
),
4622 global_node_page_state(NR_ACTIVE_FILE
),
4623 global_node_page_state(NR_INACTIVE_FILE
),
4624 global_node_page_state(NR_ISOLATED_FILE
),
4625 global_node_page_state(NR_UNEVICTABLE
),
4626 global_node_page_state(NR_FILE_DIRTY
),
4627 global_node_page_state(NR_WRITEBACK
),
4628 global_node_page_state(NR_UNSTABLE_NFS
),
4629 global_node_page_state(NR_SLAB_RECLAIMABLE
),
4630 global_node_page_state(NR_SLAB_UNRECLAIMABLE
),
4631 global_node_page_state(NR_FILE_MAPPED
),
4632 global_node_page_state(NR_SHMEM
),
4633 global_page_state(NR_PAGETABLE
),
4634 global_page_state(NR_BOUNCE
),
4635 global_page_state(NR_FREE_PAGES
),
4637 global_page_state(NR_FREE_CMA_PAGES
));
4639 for_each_online_pgdat(pgdat
) {
4640 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
4644 " active_anon:%lukB"
4645 " inactive_anon:%lukB"
4646 " active_file:%lukB"
4647 " inactive_file:%lukB"
4648 " unevictable:%lukB"
4649 " isolated(anon):%lukB"
4650 " isolated(file):%lukB"
4655 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4657 " shmem_pmdmapped: %lukB"
4660 " writeback_tmp:%lukB"
4662 " all_unreclaimable? %s"
4665 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4666 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4667 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4668 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4669 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4670 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4671 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4672 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4673 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4674 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4675 K(node_page_state(pgdat
, NR_SHMEM
)),
4676 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4677 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4678 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4680 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4682 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4683 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4684 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
4688 for_each_populated_zone(zone
) {
4691 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4695 for_each_online_cpu(cpu
)
4696 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4705 " active_anon:%lukB"
4706 " inactive_anon:%lukB"
4707 " active_file:%lukB"
4708 " inactive_file:%lukB"
4709 " unevictable:%lukB"
4710 " writepending:%lukB"
4714 " kernel_stack:%lukB"
4722 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4723 K(min_wmark_pages(zone
)),
4724 K(low_wmark_pages(zone
)),
4725 K(high_wmark_pages(zone
)),
4726 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4727 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4728 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4729 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4730 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4731 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4732 K(zone
->present_pages
),
4733 K(zone
->managed_pages
),
4734 K(zone_page_state(zone
, NR_MLOCK
)),
4735 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4736 K(zone_page_state(zone
, NR_PAGETABLE
)),
4737 K(zone_page_state(zone
, NR_BOUNCE
)),
4739 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4740 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4741 printk("lowmem_reserve[]:");
4742 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4743 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
4744 printk(KERN_CONT
"\n");
4747 for_each_populated_zone(zone
) {
4749 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4750 unsigned char types
[MAX_ORDER
];
4752 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4755 printk(KERN_CONT
"%s: ", zone
->name
);
4757 spin_lock_irqsave(&zone
->lock
, flags
);
4758 for (order
= 0; order
< MAX_ORDER
; order
++) {
4759 struct free_area
*area
= &zone
->free_area
[order
];
4762 nr
[order
] = area
->nr_free
;
4763 total
+= nr
[order
] << order
;
4766 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4767 if (!list_empty(&area
->free_list
[type
]))
4768 types
[order
] |= 1 << type
;
4771 spin_unlock_irqrestore(&zone
->lock
, flags
);
4772 for (order
= 0; order
< MAX_ORDER
; order
++) {
4773 printk(KERN_CONT
"%lu*%lukB ",
4774 nr
[order
], K(1UL) << order
);
4776 show_migration_types(types
[order
]);
4778 printk(KERN_CONT
"= %lukB\n", K(total
));
4781 hugetlb_show_meminfo();
4783 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4785 show_swap_cache_info();
4788 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4790 zoneref
->zone
= zone
;
4791 zoneref
->zone_idx
= zone_idx(zone
);
4795 * Builds allocation fallback zone lists.
4797 * Add all populated zones of a node to the zonelist.
4799 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4803 enum zone_type zone_type
= MAX_NR_ZONES
;
4807 zone
= pgdat
->node_zones
+ zone_type
;
4808 if (managed_zone(zone
)) {
4809 zoneref_set_zone(zone
,
4810 &zonelist
->_zonerefs
[nr_zones
++]);
4811 check_highest_zone(zone_type
);
4813 } while (zone_type
);
4821 * 0 = automatic detection of better ordering.
4822 * 1 = order by ([node] distance, -zonetype)
4823 * 2 = order by (-zonetype, [node] distance)
4825 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4826 * the same zonelist. So only NUMA can configure this param.
4828 #define ZONELIST_ORDER_DEFAULT 0
4829 #define ZONELIST_ORDER_NODE 1
4830 #define ZONELIST_ORDER_ZONE 2
4832 /* zonelist order in the kernel.
4833 * set_zonelist_order() will set this to NODE or ZONE.
4835 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4836 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4840 /* The value user specified ....changed by config */
4841 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4842 /* string for sysctl */
4843 #define NUMA_ZONELIST_ORDER_LEN 16
4844 char numa_zonelist_order
[16] = "default";
4847 * interface for configure zonelist ordering.
4848 * command line option "numa_zonelist_order"
4849 * = "[dD]efault - default, automatic configuration.
4850 * = "[nN]ode - order by node locality, then by zone within node
4851 * = "[zZ]one - order by zone, then by locality within zone
4854 static int __parse_numa_zonelist_order(char *s
)
4856 if (*s
== 'd' || *s
== 'D') {
4857 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4858 } else if (*s
== 'n' || *s
== 'N') {
4859 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4860 } else if (*s
== 'z' || *s
== 'Z') {
4861 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4863 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4869 static __init
int setup_numa_zonelist_order(char *s
)
4876 ret
= __parse_numa_zonelist_order(s
);
4878 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4882 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4885 * sysctl handler for numa_zonelist_order
4887 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4888 void __user
*buffer
, size_t *length
,
4891 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4893 static DEFINE_MUTEX(zl_order_mutex
);
4895 mutex_lock(&zl_order_mutex
);
4897 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4901 strcpy(saved_string
, (char *)table
->data
);
4903 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4907 int oldval
= user_zonelist_order
;
4909 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4912 * bogus value. restore saved string
4914 strncpy((char *)table
->data
, saved_string
,
4915 NUMA_ZONELIST_ORDER_LEN
);
4916 user_zonelist_order
= oldval
;
4917 } else if (oldval
!= user_zonelist_order
) {
4918 mem_hotplug_begin();
4919 mutex_lock(&zonelists_mutex
);
4920 build_all_zonelists(NULL
, NULL
);
4921 mutex_unlock(&zonelists_mutex
);
4926 mutex_unlock(&zl_order_mutex
);
4931 #define MAX_NODE_LOAD (nr_online_nodes)
4932 static int node_load
[MAX_NUMNODES
];
4935 * find_next_best_node - find the next node that should appear in a given node's fallback list
4936 * @node: node whose fallback list we're appending
4937 * @used_node_mask: nodemask_t of already used nodes
4939 * We use a number of factors to determine which is the next node that should
4940 * appear on a given node's fallback list. The node should not have appeared
4941 * already in @node's fallback list, and it should be the next closest node
4942 * according to the distance array (which contains arbitrary distance values
4943 * from each node to each node in the system), and should also prefer nodes
4944 * with no CPUs, since presumably they'll have very little allocation pressure
4945 * on them otherwise.
4946 * It returns -1 if no node is found.
4948 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4951 int min_val
= INT_MAX
;
4952 int best_node
= NUMA_NO_NODE
;
4953 const struct cpumask
*tmp
= cpumask_of_node(0);
4955 /* Use the local node if we haven't already */
4956 if (!node_isset(node
, *used_node_mask
)) {
4957 node_set(node
, *used_node_mask
);
4961 for_each_node_state(n
, N_MEMORY
) {
4963 /* Don't want a node to appear more than once */
4964 if (node_isset(n
, *used_node_mask
))
4967 /* Use the distance array to find the distance */
4968 val
= node_distance(node
, n
);
4970 /* Penalize nodes under us ("prefer the next node") */
4973 /* Give preference to headless and unused nodes */
4974 tmp
= cpumask_of_node(n
);
4975 if (!cpumask_empty(tmp
))
4976 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4978 /* Slight preference for less loaded node */
4979 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4980 val
+= node_load
[n
];
4982 if (val
< min_val
) {
4989 node_set(best_node
, *used_node_mask
);
4996 * Build zonelists ordered by node and zones within node.
4997 * This results in maximum locality--normal zone overflows into local
4998 * DMA zone, if any--but risks exhausting DMA zone.
5000 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
5003 struct zonelist
*zonelist
;
5005 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
5006 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
5008 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5009 zonelist
->_zonerefs
[j
].zone
= NULL
;
5010 zonelist
->_zonerefs
[j
].zone_idx
= 0;
5014 * Build gfp_thisnode zonelists
5016 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5019 struct zonelist
*zonelist
;
5021 zonelist
= &pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
];
5022 j
= build_zonelists_node(pgdat
, zonelist
, 0);
5023 zonelist
->_zonerefs
[j
].zone
= NULL
;
5024 zonelist
->_zonerefs
[j
].zone_idx
= 0;
5028 * Build zonelists ordered by zone and nodes within zones.
5029 * This results in conserving DMA zone[s] until all Normal memory is
5030 * exhausted, but results in overflowing to remote node while memory
5031 * may still exist in local DMA zone.
5033 static int node_order
[MAX_NUMNODES
];
5035 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
5038 int zone_type
; /* needs to be signed */
5040 struct zonelist
*zonelist
;
5042 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
5044 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
5045 for (j
= 0; j
< nr_nodes
; j
++) {
5046 node
= node_order
[j
];
5047 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
5048 if (managed_zone(z
)) {
5050 &zonelist
->_zonerefs
[pos
++]);
5051 check_highest_zone(zone_type
);
5055 zonelist
->_zonerefs
[pos
].zone
= NULL
;
5056 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
5059 #if defined(CONFIG_64BIT)
5061 * Devices that require DMA32/DMA are relatively rare and do not justify a
5062 * penalty to every machine in case the specialised case applies. Default
5063 * to Node-ordering on 64-bit NUMA machines
5065 static int default_zonelist_order(void)
5067 return ZONELIST_ORDER_NODE
;
5071 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
5072 * by the kernel. If processes running on node 0 deplete the low memory zone
5073 * then reclaim will occur more frequency increasing stalls and potentially
5074 * be easier to OOM if a large percentage of the zone is under writeback or
5075 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
5076 * Hence, default to zone ordering on 32-bit.
5078 static int default_zonelist_order(void)
5080 return ZONELIST_ORDER_ZONE
;
5082 #endif /* CONFIG_64BIT */
5084 static void set_zonelist_order(void)
5086 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
5087 current_zonelist_order
= default_zonelist_order();
5089 current_zonelist_order
= user_zonelist_order
;
5092 static void build_zonelists(pg_data_t
*pgdat
)
5095 nodemask_t used_mask
;
5096 int local_node
, prev_node
;
5097 struct zonelist
*zonelist
;
5098 unsigned int order
= current_zonelist_order
;
5100 /* initialize zonelists */
5101 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
5102 zonelist
= pgdat
->node_zonelists
+ i
;
5103 zonelist
->_zonerefs
[0].zone
= NULL
;
5104 zonelist
->_zonerefs
[0].zone_idx
= 0;
5107 /* NUMA-aware ordering of nodes */
5108 local_node
= pgdat
->node_id
;
5109 load
= nr_online_nodes
;
5110 prev_node
= local_node
;
5111 nodes_clear(used_mask
);
5113 memset(node_order
, 0, sizeof(node_order
));
5116 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5118 * We don't want to pressure a particular node.
5119 * So adding penalty to the first node in same
5120 * distance group to make it round-robin.
5122 if (node_distance(local_node
, node
) !=
5123 node_distance(local_node
, prev_node
))
5124 node_load
[node
] = load
;
5128 if (order
== ZONELIST_ORDER_NODE
)
5129 build_zonelists_in_node_order(pgdat
, node
);
5131 node_order
[i
++] = node
; /* remember order */
5134 if (order
== ZONELIST_ORDER_ZONE
) {
5135 /* calculate node order -- i.e., DMA last! */
5136 build_zonelists_in_zone_order(pgdat
, i
);
5139 build_thisnode_zonelists(pgdat
);
5142 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5144 * Return node id of node used for "local" allocations.
5145 * I.e., first node id of first zone in arg node's generic zonelist.
5146 * Used for initializing percpu 'numa_mem', which is used primarily
5147 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5149 int local_memory_node(int node
)
5153 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5154 gfp_zone(GFP_KERNEL
),
5156 return z
->zone
->node
;
5160 static void setup_min_unmapped_ratio(void);
5161 static void setup_min_slab_ratio(void);
5162 #else /* CONFIG_NUMA */
5164 static void set_zonelist_order(void)
5166 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
5169 static void build_zonelists(pg_data_t
*pgdat
)
5171 int node
, local_node
;
5173 struct zonelist
*zonelist
;
5175 local_node
= pgdat
->node_id
;
5177 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
5178 j
= build_zonelists_node(pgdat
, zonelist
, 0);
5181 * Now we build the zonelist so that it contains the zones
5182 * of all the other nodes.
5183 * We don't want to pressure a particular node, so when
5184 * building the zones for node N, we make sure that the
5185 * zones coming right after the local ones are those from
5186 * node N+1 (modulo N)
5188 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5189 if (!node_online(node
))
5191 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5193 for (node
= 0; node
< local_node
; node
++) {
5194 if (!node_online(node
))
5196 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5199 zonelist
->_zonerefs
[j
].zone
= NULL
;
5200 zonelist
->_zonerefs
[j
].zone_idx
= 0;
5203 #endif /* CONFIG_NUMA */
5206 * Boot pageset table. One per cpu which is going to be used for all
5207 * zones and all nodes. The parameters will be set in such a way
5208 * that an item put on a list will immediately be handed over to
5209 * the buddy list. This is safe since pageset manipulation is done
5210 * with interrupts disabled.
5212 * The boot_pagesets must be kept even after bootup is complete for
5213 * unused processors and/or zones. They do play a role for bootstrapping
5214 * hotplugged processors.
5216 * zoneinfo_show() and maybe other functions do
5217 * not check if the processor is online before following the pageset pointer.
5218 * Other parts of the kernel may not check if the zone is available.
5220 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5221 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5222 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5223 static void setup_zone_pageset(struct zone
*zone
);
5226 * Global mutex to protect against size modification of zonelists
5227 * as well as to serialize pageset setup for the new populated zone.
5229 DEFINE_MUTEX(zonelists_mutex
);
5231 /* return values int ....just for stop_machine() */
5232 static int __build_all_zonelists(void *data
)
5236 pg_data_t
*self
= data
;
5239 memset(node_load
, 0, sizeof(node_load
));
5242 if (self
&& !node_online(self
->node_id
)) {
5243 build_zonelists(self
);
5246 for_each_online_node(nid
) {
5247 pg_data_t
*pgdat
= NODE_DATA(nid
);
5249 build_zonelists(pgdat
);
5253 * Initialize the boot_pagesets that are going to be used
5254 * for bootstrapping processors. The real pagesets for
5255 * each zone will be allocated later when the per cpu
5256 * allocator is available.
5258 * boot_pagesets are used also for bootstrapping offline
5259 * cpus if the system is already booted because the pagesets
5260 * are needed to initialize allocators on a specific cpu too.
5261 * F.e. the percpu allocator needs the page allocator which
5262 * needs the percpu allocator in order to allocate its pagesets
5263 * (a chicken-egg dilemma).
5265 for_each_possible_cpu(cpu
) {
5266 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5268 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5270 * We now know the "local memory node" for each node--
5271 * i.e., the node of the first zone in the generic zonelist.
5272 * Set up numa_mem percpu variable for on-line cpus. During
5273 * boot, only the boot cpu should be on-line; we'll init the
5274 * secondary cpus' numa_mem as they come on-line. During
5275 * node/memory hotplug, we'll fixup all on-line cpus.
5277 if (cpu_online(cpu
))
5278 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5285 static noinline
void __init
5286 build_all_zonelists_init(void)
5288 __build_all_zonelists(NULL
);
5289 mminit_verify_zonelist();
5290 cpuset_init_current_mems_allowed();
5294 * Called with zonelists_mutex held always
5295 * unless system_state == SYSTEM_BOOTING.
5297 * __ref due to (1) call of __meminit annotated setup_zone_pageset
5298 * [we're only called with non-NULL zone through __meminit paths] and
5299 * (2) call of __init annotated helper build_all_zonelists_init
5300 * [protected by SYSTEM_BOOTING].
5302 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
5304 set_zonelist_order();
5306 if (system_state
== SYSTEM_BOOTING
) {
5307 build_all_zonelists_init();
5309 #ifdef CONFIG_MEMORY_HOTPLUG
5311 setup_zone_pageset(zone
);
5313 /* we have to stop all cpus to guarantee there is no user
5315 stop_machine_cpuslocked(__build_all_zonelists
, pgdat
, NULL
);
5316 /* cpuset refresh routine should be here */
5318 vm_total_pages
= nr_free_pagecache_pages();
5320 * Disable grouping by mobility if the number of pages in the
5321 * system is too low to allow the mechanism to work. It would be
5322 * more accurate, but expensive to check per-zone. This check is
5323 * made on memory-hotadd so a system can start with mobility
5324 * disabled and enable it later
5326 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5327 page_group_by_mobility_disabled
= 1;
5329 page_group_by_mobility_disabled
= 0;
5331 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5333 zonelist_order_name
[current_zonelist_order
],
5334 page_group_by_mobility_disabled
? "off" : "on",
5337 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5342 * Initially all pages are reserved - free ones are freed
5343 * up by free_all_bootmem() once the early boot process is
5344 * done. Non-atomic initialization, single-pass.
5346 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5347 unsigned long start_pfn
, enum memmap_context context
)
5349 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5350 unsigned long end_pfn
= start_pfn
+ size
;
5351 pg_data_t
*pgdat
= NODE_DATA(nid
);
5353 unsigned long nr_initialised
= 0;
5354 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5355 struct memblock_region
*r
= NULL
, *tmp
;
5358 if (highest_memmap_pfn
< end_pfn
- 1)
5359 highest_memmap_pfn
= end_pfn
- 1;
5362 * Honor reservation requested by the driver for this ZONE_DEVICE
5365 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5366 start_pfn
+= altmap
->reserve
;
5368 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5370 * There can be holes in boot-time mem_map[]s handed to this
5371 * function. They do not exist on hotplugged memory.
5373 if (context
!= MEMMAP_EARLY
)
5376 if (!early_pfn_valid(pfn
)) {
5377 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5379 * Skip to the pfn preceding the next valid one (or
5380 * end_pfn), such that we hit a valid pfn (or end_pfn)
5381 * on our next iteration of the loop.
5383 pfn
= memblock_next_valid_pfn(pfn
, end_pfn
) - 1;
5387 if (!early_pfn_in_nid(pfn
, nid
))
5389 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5392 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5394 * Check given memblock attribute by firmware which can affect
5395 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5396 * mirrored, it's an overlapped memmap init. skip it.
5398 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5399 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5400 for_each_memblock(memory
, tmp
)
5401 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5405 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5406 memblock_is_mirror(r
)) {
5407 /* already initialized as NORMAL */
5408 pfn
= memblock_region_memory_end_pfn(r
);
5416 * Mark the block movable so that blocks are reserved for
5417 * movable at startup. This will force kernel allocations
5418 * to reserve their blocks rather than leaking throughout
5419 * the address space during boot when many long-lived
5420 * kernel allocations are made.
5422 * bitmap is created for zone's valid pfn range. but memmap
5423 * can be created for invalid pages (for alignment)
5424 * check here not to call set_pageblock_migratetype() against
5427 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5428 struct page
*page
= pfn_to_page(pfn
);
5430 __init_single_page(page
, pfn
, zone
, nid
);
5431 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5433 __init_single_pfn(pfn
, zone
, nid
);
5438 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5440 unsigned int order
, t
;
5441 for_each_migratetype_order(order
, t
) {
5442 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5443 zone
->free_area
[order
].nr_free
= 0;
5447 #ifndef __HAVE_ARCH_MEMMAP_INIT
5448 #define memmap_init(size, nid, zone, start_pfn) \
5449 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5452 static int zone_batchsize(struct zone
*zone
)
5458 * The per-cpu-pages pools are set to around 1000th of the
5459 * size of the zone. But no more than 1/2 of a meg.
5461 * OK, so we don't know how big the cache is. So guess.
5463 batch
= zone
->managed_pages
/ 1024;
5464 if (batch
* PAGE_SIZE
> 512 * 1024)
5465 batch
= (512 * 1024) / PAGE_SIZE
;
5466 batch
/= 4; /* We effectively *= 4 below */
5471 * Clamp the batch to a 2^n - 1 value. Having a power
5472 * of 2 value was found to be more likely to have
5473 * suboptimal cache aliasing properties in some cases.
5475 * For example if 2 tasks are alternately allocating
5476 * batches of pages, one task can end up with a lot
5477 * of pages of one half of the possible page colors
5478 * and the other with pages of the other colors.
5480 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5485 /* The deferral and batching of frees should be suppressed under NOMMU
5488 * The problem is that NOMMU needs to be able to allocate large chunks
5489 * of contiguous memory as there's no hardware page translation to
5490 * assemble apparent contiguous memory from discontiguous pages.
5492 * Queueing large contiguous runs of pages for batching, however,
5493 * causes the pages to actually be freed in smaller chunks. As there
5494 * can be a significant delay between the individual batches being
5495 * recycled, this leads to the once large chunks of space being
5496 * fragmented and becoming unavailable for high-order allocations.
5503 * pcp->high and pcp->batch values are related and dependent on one another:
5504 * ->batch must never be higher then ->high.
5505 * The following function updates them in a safe manner without read side
5508 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5509 * those fields changing asynchronously (acording the the above rule).
5511 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5512 * outside of boot time (or some other assurance that no concurrent updaters
5515 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5516 unsigned long batch
)
5518 /* start with a fail safe value for batch */
5522 /* Update high, then batch, in order */
5529 /* a companion to pageset_set_high() */
5530 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5532 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5535 static void pageset_init(struct per_cpu_pageset
*p
)
5537 struct per_cpu_pages
*pcp
;
5540 memset(p
, 0, sizeof(*p
));
5544 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5545 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5548 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5551 pageset_set_batch(p
, batch
);
5555 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5556 * to the value high for the pageset p.
5558 static void pageset_set_high(struct per_cpu_pageset
*p
,
5561 unsigned long batch
= max(1UL, high
/ 4);
5562 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5563 batch
= PAGE_SHIFT
* 8;
5565 pageset_update(&p
->pcp
, high
, batch
);
5568 static void pageset_set_high_and_batch(struct zone
*zone
,
5569 struct per_cpu_pageset
*pcp
)
5571 if (percpu_pagelist_fraction
)
5572 pageset_set_high(pcp
,
5573 (zone
->managed_pages
/
5574 percpu_pagelist_fraction
));
5576 pageset_set_batch(pcp
, zone_batchsize(zone
));
5579 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5581 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5584 pageset_set_high_and_batch(zone
, pcp
);
5587 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5590 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5591 for_each_possible_cpu(cpu
)
5592 zone_pageset_init(zone
, cpu
);
5596 * Allocate per cpu pagesets and initialize them.
5597 * Before this call only boot pagesets were available.
5599 void __init
setup_per_cpu_pageset(void)
5601 struct pglist_data
*pgdat
;
5604 for_each_populated_zone(zone
)
5605 setup_zone_pageset(zone
);
5607 for_each_online_pgdat(pgdat
)
5608 pgdat
->per_cpu_nodestats
=
5609 alloc_percpu(struct per_cpu_nodestat
);
5612 static __meminit
void zone_pcp_init(struct zone
*zone
)
5615 * per cpu subsystem is not up at this point. The following code
5616 * relies on the ability of the linker to provide the
5617 * offset of a (static) per cpu variable into the per cpu area.
5619 zone
->pageset
= &boot_pageset
;
5621 if (populated_zone(zone
))
5622 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5623 zone
->name
, zone
->present_pages
,
5624 zone_batchsize(zone
));
5627 void __meminit
init_currently_empty_zone(struct zone
*zone
,
5628 unsigned long zone_start_pfn
,
5631 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5633 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5635 zone
->zone_start_pfn
= zone_start_pfn
;
5637 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5638 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5640 (unsigned long)zone_idx(zone
),
5641 zone_start_pfn
, (zone_start_pfn
+ size
));
5643 zone_init_free_lists(zone
);
5644 zone
->initialized
= 1;
5647 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5648 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5651 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5653 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5654 struct mminit_pfnnid_cache
*state
)
5656 unsigned long start_pfn
, end_pfn
;
5659 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5660 return state
->last_nid
;
5662 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5664 state
->last_start
= start_pfn
;
5665 state
->last_end
= end_pfn
;
5666 state
->last_nid
= nid
;
5671 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5674 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5675 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5676 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5678 * If an architecture guarantees that all ranges registered contain no holes
5679 * and may be freed, this this function may be used instead of calling
5680 * memblock_free_early_nid() manually.
5682 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5684 unsigned long start_pfn
, end_pfn
;
5687 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5688 start_pfn
= min(start_pfn
, max_low_pfn
);
5689 end_pfn
= min(end_pfn
, max_low_pfn
);
5691 if (start_pfn
< end_pfn
)
5692 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5693 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5699 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5700 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5702 * If an architecture guarantees that all ranges registered contain no holes and may
5703 * be freed, this function may be used instead of calling memory_present() manually.
5705 void __init
sparse_memory_present_with_active_regions(int nid
)
5707 unsigned long start_pfn
, end_pfn
;
5710 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5711 memory_present(this_nid
, start_pfn
, end_pfn
);
5715 * get_pfn_range_for_nid - Return the start and end page frames for a node
5716 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5717 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5718 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5720 * It returns the start and end page frame of a node based on information
5721 * provided by memblock_set_node(). If called for a node
5722 * with no available memory, a warning is printed and the start and end
5725 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5726 unsigned long *start_pfn
, unsigned long *end_pfn
)
5728 unsigned long this_start_pfn
, this_end_pfn
;
5734 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5735 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5736 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5739 if (*start_pfn
== -1UL)
5744 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5745 * assumption is made that zones within a node are ordered in monotonic
5746 * increasing memory addresses so that the "highest" populated zone is used
5748 static void __init
find_usable_zone_for_movable(void)
5751 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5752 if (zone_index
== ZONE_MOVABLE
)
5755 if (arch_zone_highest_possible_pfn
[zone_index
] >
5756 arch_zone_lowest_possible_pfn
[zone_index
])
5760 VM_BUG_ON(zone_index
== -1);
5761 movable_zone
= zone_index
;
5765 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5766 * because it is sized independent of architecture. Unlike the other zones,
5767 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5768 * in each node depending on the size of each node and how evenly kernelcore
5769 * is distributed. This helper function adjusts the zone ranges
5770 * provided by the architecture for a given node by using the end of the
5771 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5772 * zones within a node are in order of monotonic increases memory addresses
5774 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5775 unsigned long zone_type
,
5776 unsigned long node_start_pfn
,
5777 unsigned long node_end_pfn
,
5778 unsigned long *zone_start_pfn
,
5779 unsigned long *zone_end_pfn
)
5781 /* Only adjust if ZONE_MOVABLE is on this node */
5782 if (zone_movable_pfn
[nid
]) {
5783 /* Size ZONE_MOVABLE */
5784 if (zone_type
== ZONE_MOVABLE
) {
5785 *zone_start_pfn
= zone_movable_pfn
[nid
];
5786 *zone_end_pfn
= min(node_end_pfn
,
5787 arch_zone_highest_possible_pfn
[movable_zone
]);
5789 /* Adjust for ZONE_MOVABLE starting within this range */
5790 } else if (!mirrored_kernelcore
&&
5791 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
5792 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5793 *zone_end_pfn
= zone_movable_pfn
[nid
];
5795 /* Check if this whole range is within ZONE_MOVABLE */
5796 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5797 *zone_start_pfn
= *zone_end_pfn
;
5802 * Return the number of pages a zone spans in a node, including holes
5803 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5805 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5806 unsigned long zone_type
,
5807 unsigned long node_start_pfn
,
5808 unsigned long node_end_pfn
,
5809 unsigned long *zone_start_pfn
,
5810 unsigned long *zone_end_pfn
,
5811 unsigned long *ignored
)
5813 /* When hotadd a new node from cpu_up(), the node should be empty */
5814 if (!node_start_pfn
&& !node_end_pfn
)
5817 /* Get the start and end of the zone */
5818 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5819 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5820 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5821 node_start_pfn
, node_end_pfn
,
5822 zone_start_pfn
, zone_end_pfn
);
5824 /* Check that this node has pages within the zone's required range */
5825 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5828 /* Move the zone boundaries inside the node if necessary */
5829 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5830 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5832 /* Return the spanned pages */
5833 return *zone_end_pfn
- *zone_start_pfn
;
5837 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5838 * then all holes in the requested range will be accounted for.
5840 unsigned long __meminit
__absent_pages_in_range(int nid
,
5841 unsigned long range_start_pfn
,
5842 unsigned long range_end_pfn
)
5844 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5845 unsigned long start_pfn
, end_pfn
;
5848 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5849 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5850 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5851 nr_absent
-= end_pfn
- start_pfn
;
5857 * absent_pages_in_range - Return number of page frames in holes within a range
5858 * @start_pfn: The start PFN to start searching for holes
5859 * @end_pfn: The end PFN to stop searching for holes
5861 * It returns the number of pages frames in memory holes within a range.
5863 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5864 unsigned long end_pfn
)
5866 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5869 /* Return the number of page frames in holes in a zone on a node */
5870 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5871 unsigned long zone_type
,
5872 unsigned long node_start_pfn
,
5873 unsigned long node_end_pfn
,
5874 unsigned long *ignored
)
5876 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5877 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5878 unsigned long zone_start_pfn
, zone_end_pfn
;
5879 unsigned long nr_absent
;
5881 /* When hotadd a new node from cpu_up(), the node should be empty */
5882 if (!node_start_pfn
&& !node_end_pfn
)
5885 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5886 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5888 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5889 node_start_pfn
, node_end_pfn
,
5890 &zone_start_pfn
, &zone_end_pfn
);
5891 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5894 * ZONE_MOVABLE handling.
5895 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5898 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
5899 unsigned long start_pfn
, end_pfn
;
5900 struct memblock_region
*r
;
5902 for_each_memblock(memory
, r
) {
5903 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5904 zone_start_pfn
, zone_end_pfn
);
5905 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5906 zone_start_pfn
, zone_end_pfn
);
5908 if (zone_type
== ZONE_MOVABLE
&&
5909 memblock_is_mirror(r
))
5910 nr_absent
+= end_pfn
- start_pfn
;
5912 if (zone_type
== ZONE_NORMAL
&&
5913 !memblock_is_mirror(r
))
5914 nr_absent
+= end_pfn
- start_pfn
;
5921 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5922 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5923 unsigned long zone_type
,
5924 unsigned long node_start_pfn
,
5925 unsigned long node_end_pfn
,
5926 unsigned long *zone_start_pfn
,
5927 unsigned long *zone_end_pfn
,
5928 unsigned long *zones_size
)
5932 *zone_start_pfn
= node_start_pfn
;
5933 for (zone
= 0; zone
< zone_type
; zone
++)
5934 *zone_start_pfn
+= zones_size
[zone
];
5936 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5938 return zones_size
[zone_type
];
5941 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5942 unsigned long zone_type
,
5943 unsigned long node_start_pfn
,
5944 unsigned long node_end_pfn
,
5945 unsigned long *zholes_size
)
5950 return zholes_size
[zone_type
];
5953 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5955 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5956 unsigned long node_start_pfn
,
5957 unsigned long node_end_pfn
,
5958 unsigned long *zones_size
,
5959 unsigned long *zholes_size
)
5961 unsigned long realtotalpages
= 0, totalpages
= 0;
5964 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5965 struct zone
*zone
= pgdat
->node_zones
+ i
;
5966 unsigned long zone_start_pfn
, zone_end_pfn
;
5967 unsigned long size
, real_size
;
5969 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5975 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5976 node_start_pfn
, node_end_pfn
,
5979 zone
->zone_start_pfn
= zone_start_pfn
;
5981 zone
->zone_start_pfn
= 0;
5982 zone
->spanned_pages
= size
;
5983 zone
->present_pages
= real_size
;
5986 realtotalpages
+= real_size
;
5989 pgdat
->node_spanned_pages
= totalpages
;
5990 pgdat
->node_present_pages
= realtotalpages
;
5991 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5995 #ifndef CONFIG_SPARSEMEM
5997 * Calculate the size of the zone->blockflags rounded to an unsigned long
5998 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5999 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6000 * round what is now in bits to nearest long in bits, then return it in
6003 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
6005 unsigned long usemapsize
;
6007 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
6008 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
6009 usemapsize
= usemapsize
>> pageblock_order
;
6010 usemapsize
*= NR_PAGEBLOCK_BITS
;
6011 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
6013 return usemapsize
/ 8;
6016 static void __init
setup_usemap(struct pglist_data
*pgdat
,
6018 unsigned long zone_start_pfn
,
6019 unsigned long zonesize
)
6021 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
6022 zone
->pageblock_flags
= NULL
;
6024 zone
->pageblock_flags
=
6025 memblock_virt_alloc_node_nopanic(usemapsize
,
6029 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
6030 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
6031 #endif /* CONFIG_SPARSEMEM */
6033 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6035 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6036 void __paginginit
set_pageblock_order(void)
6040 /* Check that pageblock_nr_pages has not already been setup */
6041 if (pageblock_order
)
6044 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6045 order
= HUGETLB_PAGE_ORDER
;
6047 order
= MAX_ORDER
- 1;
6050 * Assume the largest contiguous order of interest is a huge page.
6051 * This value may be variable depending on boot parameters on IA64 and
6054 pageblock_order
= order
;
6056 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6059 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6060 * is unused as pageblock_order is set at compile-time. See
6061 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6064 void __paginginit
set_pageblock_order(void)
6068 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6070 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
6071 unsigned long present_pages
)
6073 unsigned long pages
= spanned_pages
;
6076 * Provide a more accurate estimation if there are holes within
6077 * the zone and SPARSEMEM is in use. If there are holes within the
6078 * zone, each populated memory region may cost us one or two extra
6079 * memmap pages due to alignment because memmap pages for each
6080 * populated regions may not be naturally aligned on page boundary.
6081 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6083 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6084 IS_ENABLED(CONFIG_SPARSEMEM
))
6085 pages
= present_pages
;
6087 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6091 * Set up the zone data structures:
6092 * - mark all pages reserved
6093 * - mark all memory queues empty
6094 * - clear the memory bitmaps
6096 * NOTE: pgdat should get zeroed by caller.
6098 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
6101 int nid
= pgdat
->node_id
;
6103 pgdat_resize_init(pgdat
);
6104 #ifdef CONFIG_NUMA_BALANCING
6105 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
6106 pgdat
->numabalancing_migrate_nr_pages
= 0;
6107 pgdat
->numabalancing_migrate_next_window
= jiffies
;
6109 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6110 spin_lock_init(&pgdat
->split_queue_lock
);
6111 INIT_LIST_HEAD(&pgdat
->split_queue
);
6112 pgdat
->split_queue_len
= 0;
6114 init_waitqueue_head(&pgdat
->kswapd_wait
);
6115 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6116 #ifdef CONFIG_COMPACTION
6117 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6119 pgdat_page_ext_init(pgdat
);
6120 spin_lock_init(&pgdat
->lru_lock
);
6121 lruvec_init(node_lruvec(pgdat
));
6123 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6125 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6126 struct zone
*zone
= pgdat
->node_zones
+ j
;
6127 unsigned long size
, realsize
, freesize
, memmap_pages
;
6128 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6130 size
= zone
->spanned_pages
;
6131 realsize
= freesize
= zone
->present_pages
;
6134 * Adjust freesize so that it accounts for how much memory
6135 * is used by this zone for memmap. This affects the watermark
6136 * and per-cpu initialisations
6138 memmap_pages
= calc_memmap_size(size
, realsize
);
6139 if (!is_highmem_idx(j
)) {
6140 if (freesize
>= memmap_pages
) {
6141 freesize
-= memmap_pages
;
6144 " %s zone: %lu pages used for memmap\n",
6145 zone_names
[j
], memmap_pages
);
6147 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6148 zone_names
[j
], memmap_pages
, freesize
);
6151 /* Account for reserved pages */
6152 if (j
== 0 && freesize
> dma_reserve
) {
6153 freesize
-= dma_reserve
;
6154 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6155 zone_names
[0], dma_reserve
);
6158 if (!is_highmem_idx(j
))
6159 nr_kernel_pages
+= freesize
;
6160 /* Charge for highmem memmap if there are enough kernel pages */
6161 else if (nr_kernel_pages
> memmap_pages
* 2)
6162 nr_kernel_pages
-= memmap_pages
;
6163 nr_all_pages
+= freesize
;
6166 * Set an approximate value for lowmem here, it will be adjusted
6167 * when the bootmem allocator frees pages into the buddy system.
6168 * And all highmem pages will be managed by the buddy system.
6170 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
6174 zone
->name
= zone_names
[j
];
6175 zone
->zone_pgdat
= pgdat
;
6176 spin_lock_init(&zone
->lock
);
6177 zone_seqlock_init(zone
);
6178 zone_pcp_init(zone
);
6183 set_pageblock_order();
6184 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6185 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6186 memmap_init(size
, nid
, j
, zone_start_pfn
);
6190 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6192 unsigned long __maybe_unused start
= 0;
6193 unsigned long __maybe_unused offset
= 0;
6195 /* Skip empty nodes */
6196 if (!pgdat
->node_spanned_pages
)
6199 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6200 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6201 offset
= pgdat
->node_start_pfn
- start
;
6202 /* ia64 gets its own node_mem_map, before this, without bootmem */
6203 if (!pgdat
->node_mem_map
) {
6204 unsigned long size
, end
;
6208 * The zone's endpoints aren't required to be MAX_ORDER
6209 * aligned but the node_mem_map endpoints must be in order
6210 * for the buddy allocator to function correctly.
6212 end
= pgdat_end_pfn(pgdat
);
6213 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6214 size
= (end
- start
) * sizeof(struct page
);
6215 map
= alloc_remap(pgdat
->node_id
, size
);
6217 map
= memblock_virt_alloc_node_nopanic(size
,
6219 pgdat
->node_mem_map
= map
+ offset
;
6221 #ifndef CONFIG_NEED_MULTIPLE_NODES
6223 * With no DISCONTIG, the global mem_map is just set as node 0's
6225 if (pgdat
== NODE_DATA(0)) {
6226 mem_map
= NODE_DATA(0)->node_mem_map
;
6227 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6228 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6230 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6233 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6236 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6237 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6239 pg_data_t
*pgdat
= NODE_DATA(nid
);
6240 unsigned long start_pfn
= 0;
6241 unsigned long end_pfn
= 0;
6243 /* pg_data_t should be reset to zero when it's allocated */
6244 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6246 pgdat
->node_id
= nid
;
6247 pgdat
->node_start_pfn
= node_start_pfn
;
6248 pgdat
->per_cpu_nodestats
= NULL
;
6249 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6250 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6251 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6252 (u64
)start_pfn
<< PAGE_SHIFT
,
6253 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6255 start_pfn
= node_start_pfn
;
6257 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6258 zones_size
, zholes_size
);
6260 alloc_node_mem_map(pgdat
);
6261 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6262 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6263 nid
, (unsigned long)pgdat
,
6264 (unsigned long)pgdat
->node_mem_map
);
6267 reset_deferred_meminit(pgdat
);
6268 free_area_init_core(pgdat
);
6271 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6273 #if MAX_NUMNODES > 1
6275 * Figure out the number of possible node ids.
6277 void __init
setup_nr_node_ids(void)
6279 unsigned int highest
;
6281 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6282 nr_node_ids
= highest
+ 1;
6287 * node_map_pfn_alignment - determine the maximum internode alignment
6289 * This function should be called after node map is populated and sorted.
6290 * It calculates the maximum power of two alignment which can distinguish
6293 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6294 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6295 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6296 * shifted, 1GiB is enough and this function will indicate so.
6298 * This is used to test whether pfn -> nid mapping of the chosen memory
6299 * model has fine enough granularity to avoid incorrect mapping for the
6300 * populated node map.
6302 * Returns the determined alignment in pfn's. 0 if there is no alignment
6303 * requirement (single node).
6305 unsigned long __init
node_map_pfn_alignment(void)
6307 unsigned long accl_mask
= 0, last_end
= 0;
6308 unsigned long start
, end
, mask
;
6312 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6313 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6320 * Start with a mask granular enough to pin-point to the
6321 * start pfn and tick off bits one-by-one until it becomes
6322 * too coarse to separate the current node from the last.
6324 mask
= ~((1 << __ffs(start
)) - 1);
6325 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6328 /* accumulate all internode masks */
6332 /* convert mask to number of pages */
6333 return ~accl_mask
+ 1;
6336 /* Find the lowest pfn for a node */
6337 static unsigned long __init
find_min_pfn_for_node(int nid
)
6339 unsigned long min_pfn
= ULONG_MAX
;
6340 unsigned long start_pfn
;
6343 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6344 min_pfn
= min(min_pfn
, start_pfn
);
6346 if (min_pfn
== ULONG_MAX
) {
6347 pr_warn("Could not find start_pfn for node %d\n", nid
);
6355 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6357 * It returns the minimum PFN based on information provided via
6358 * memblock_set_node().
6360 unsigned long __init
find_min_pfn_with_active_regions(void)
6362 return find_min_pfn_for_node(MAX_NUMNODES
);
6366 * early_calculate_totalpages()
6367 * Sum pages in active regions for movable zone.
6368 * Populate N_MEMORY for calculating usable_nodes.
6370 static unsigned long __init
early_calculate_totalpages(void)
6372 unsigned long totalpages
= 0;
6373 unsigned long start_pfn
, end_pfn
;
6376 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6377 unsigned long pages
= end_pfn
- start_pfn
;
6379 totalpages
+= pages
;
6381 node_set_state(nid
, N_MEMORY
);
6387 * Find the PFN the Movable zone begins in each node. Kernel memory
6388 * is spread evenly between nodes as long as the nodes have enough
6389 * memory. When they don't, some nodes will have more kernelcore than
6392 static void __init
find_zone_movable_pfns_for_nodes(void)
6395 unsigned long usable_startpfn
;
6396 unsigned long kernelcore_node
, kernelcore_remaining
;
6397 /* save the state before borrow the nodemask */
6398 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6399 unsigned long totalpages
= early_calculate_totalpages();
6400 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6401 struct memblock_region
*r
;
6403 /* Need to find movable_zone earlier when movable_node is specified. */
6404 find_usable_zone_for_movable();
6407 * If movable_node is specified, ignore kernelcore and movablecore
6410 if (movable_node_is_enabled()) {
6411 for_each_memblock(memory
, r
) {
6412 if (!memblock_is_hotpluggable(r
))
6417 usable_startpfn
= PFN_DOWN(r
->base
);
6418 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6419 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6427 * If kernelcore=mirror is specified, ignore movablecore option
6429 if (mirrored_kernelcore
) {
6430 bool mem_below_4gb_not_mirrored
= false;
6432 for_each_memblock(memory
, r
) {
6433 if (memblock_is_mirror(r
))
6438 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6440 if (usable_startpfn
< 0x100000) {
6441 mem_below_4gb_not_mirrored
= true;
6445 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6446 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6450 if (mem_below_4gb_not_mirrored
)
6451 pr_warn("This configuration results in unmirrored kernel memory.");
6457 * If movablecore=nn[KMG] was specified, calculate what size of
6458 * kernelcore that corresponds so that memory usable for
6459 * any allocation type is evenly spread. If both kernelcore
6460 * and movablecore are specified, then the value of kernelcore
6461 * will be used for required_kernelcore if it's greater than
6462 * what movablecore would have allowed.
6464 if (required_movablecore
) {
6465 unsigned long corepages
;
6468 * Round-up so that ZONE_MOVABLE is at least as large as what
6469 * was requested by the user
6471 required_movablecore
=
6472 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6473 required_movablecore
= min(totalpages
, required_movablecore
);
6474 corepages
= totalpages
- required_movablecore
;
6476 required_kernelcore
= max(required_kernelcore
, corepages
);
6480 * If kernelcore was not specified or kernelcore size is larger
6481 * than totalpages, there is no ZONE_MOVABLE.
6483 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6486 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6487 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6490 /* Spread kernelcore memory as evenly as possible throughout nodes */
6491 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6492 for_each_node_state(nid
, N_MEMORY
) {
6493 unsigned long start_pfn
, end_pfn
;
6496 * Recalculate kernelcore_node if the division per node
6497 * now exceeds what is necessary to satisfy the requested
6498 * amount of memory for the kernel
6500 if (required_kernelcore
< kernelcore_node
)
6501 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6504 * As the map is walked, we track how much memory is usable
6505 * by the kernel using kernelcore_remaining. When it is
6506 * 0, the rest of the node is usable by ZONE_MOVABLE
6508 kernelcore_remaining
= kernelcore_node
;
6510 /* Go through each range of PFNs within this node */
6511 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6512 unsigned long size_pages
;
6514 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6515 if (start_pfn
>= end_pfn
)
6518 /* Account for what is only usable for kernelcore */
6519 if (start_pfn
< usable_startpfn
) {
6520 unsigned long kernel_pages
;
6521 kernel_pages
= min(end_pfn
, usable_startpfn
)
6524 kernelcore_remaining
-= min(kernel_pages
,
6525 kernelcore_remaining
);
6526 required_kernelcore
-= min(kernel_pages
,
6527 required_kernelcore
);
6529 /* Continue if range is now fully accounted */
6530 if (end_pfn
<= usable_startpfn
) {
6533 * Push zone_movable_pfn to the end so
6534 * that if we have to rebalance
6535 * kernelcore across nodes, we will
6536 * not double account here
6538 zone_movable_pfn
[nid
] = end_pfn
;
6541 start_pfn
= usable_startpfn
;
6545 * The usable PFN range for ZONE_MOVABLE is from
6546 * start_pfn->end_pfn. Calculate size_pages as the
6547 * number of pages used as kernelcore
6549 size_pages
= end_pfn
- start_pfn
;
6550 if (size_pages
> kernelcore_remaining
)
6551 size_pages
= kernelcore_remaining
;
6552 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6555 * Some kernelcore has been met, update counts and
6556 * break if the kernelcore for this node has been
6559 required_kernelcore
-= min(required_kernelcore
,
6561 kernelcore_remaining
-= size_pages
;
6562 if (!kernelcore_remaining
)
6568 * If there is still required_kernelcore, we do another pass with one
6569 * less node in the count. This will push zone_movable_pfn[nid] further
6570 * along on the nodes that still have memory until kernelcore is
6574 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6578 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6579 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6580 zone_movable_pfn
[nid
] =
6581 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6584 /* restore the node_state */
6585 node_states
[N_MEMORY
] = saved_node_state
;
6588 /* Any regular or high memory on that node ? */
6589 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6591 enum zone_type zone_type
;
6593 if (N_MEMORY
== N_NORMAL_MEMORY
)
6596 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6597 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6598 if (populated_zone(zone
)) {
6599 node_set_state(nid
, N_HIGH_MEMORY
);
6600 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6601 zone_type
<= ZONE_NORMAL
)
6602 node_set_state(nid
, N_NORMAL_MEMORY
);
6609 * free_area_init_nodes - Initialise all pg_data_t and zone data
6610 * @max_zone_pfn: an array of max PFNs for each zone
6612 * This will call free_area_init_node() for each active node in the system.
6613 * Using the page ranges provided by memblock_set_node(), the size of each
6614 * zone in each node and their holes is calculated. If the maximum PFN
6615 * between two adjacent zones match, it is assumed that the zone is empty.
6616 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6617 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6618 * starts where the previous one ended. For example, ZONE_DMA32 starts
6619 * at arch_max_dma_pfn.
6621 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6623 unsigned long start_pfn
, end_pfn
;
6626 /* Record where the zone boundaries are */
6627 memset(arch_zone_lowest_possible_pfn
, 0,
6628 sizeof(arch_zone_lowest_possible_pfn
));
6629 memset(arch_zone_highest_possible_pfn
, 0,
6630 sizeof(arch_zone_highest_possible_pfn
));
6632 start_pfn
= find_min_pfn_with_active_regions();
6634 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6635 if (i
== ZONE_MOVABLE
)
6638 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6639 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6640 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6642 start_pfn
= end_pfn
;
6645 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6646 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6647 find_zone_movable_pfns_for_nodes();
6649 /* Print out the zone ranges */
6650 pr_info("Zone ranges:\n");
6651 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6652 if (i
== ZONE_MOVABLE
)
6654 pr_info(" %-8s ", zone_names
[i
]);
6655 if (arch_zone_lowest_possible_pfn
[i
] ==
6656 arch_zone_highest_possible_pfn
[i
])
6659 pr_cont("[mem %#018Lx-%#018Lx]\n",
6660 (u64
)arch_zone_lowest_possible_pfn
[i
]
6662 ((u64
)arch_zone_highest_possible_pfn
[i
]
6663 << PAGE_SHIFT
) - 1);
6666 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6667 pr_info("Movable zone start for each node\n");
6668 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6669 if (zone_movable_pfn
[i
])
6670 pr_info(" Node %d: %#018Lx\n", i
,
6671 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6674 /* Print out the early node map */
6675 pr_info("Early memory node ranges\n");
6676 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6677 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6678 (u64
)start_pfn
<< PAGE_SHIFT
,
6679 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6681 /* Initialise every node */
6682 mminit_verify_pageflags_layout();
6683 setup_nr_node_ids();
6684 for_each_online_node(nid
) {
6685 pg_data_t
*pgdat
= NODE_DATA(nid
);
6686 free_area_init_node(nid
, NULL
,
6687 find_min_pfn_for_node(nid
), NULL
);
6689 /* Any memory on that node */
6690 if (pgdat
->node_present_pages
)
6691 node_set_state(nid
, N_MEMORY
);
6692 check_for_memory(pgdat
, nid
);
6696 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6698 unsigned long long coremem
;
6702 coremem
= memparse(p
, &p
);
6703 *core
= coremem
>> PAGE_SHIFT
;
6705 /* Paranoid check that UL is enough for the coremem value */
6706 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6712 * kernelcore=size sets the amount of memory for use for allocations that
6713 * cannot be reclaimed or migrated.
6715 static int __init
cmdline_parse_kernelcore(char *p
)
6717 /* parse kernelcore=mirror */
6718 if (parse_option_str(p
, "mirror")) {
6719 mirrored_kernelcore
= true;
6723 return cmdline_parse_core(p
, &required_kernelcore
);
6727 * movablecore=size sets the amount of memory for use for allocations that
6728 * can be reclaimed or migrated.
6730 static int __init
cmdline_parse_movablecore(char *p
)
6732 return cmdline_parse_core(p
, &required_movablecore
);
6735 early_param("kernelcore", cmdline_parse_kernelcore
);
6736 early_param("movablecore", cmdline_parse_movablecore
);
6738 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6740 void adjust_managed_page_count(struct page
*page
, long count
)
6742 spin_lock(&managed_page_count_lock
);
6743 page_zone(page
)->managed_pages
+= count
;
6744 totalram_pages
+= count
;
6745 #ifdef CONFIG_HIGHMEM
6746 if (PageHighMem(page
))
6747 totalhigh_pages
+= count
;
6749 spin_unlock(&managed_page_count_lock
);
6751 EXPORT_SYMBOL(adjust_managed_page_count
);
6753 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6756 unsigned long pages
= 0;
6758 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6759 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6760 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6761 if ((unsigned int)poison
<= 0xFF)
6762 memset(pos
, poison
, PAGE_SIZE
);
6763 free_reserved_page(virt_to_page(pos
));
6767 pr_info("Freeing %s memory: %ldK\n",
6768 s
, pages
<< (PAGE_SHIFT
- 10));
6772 EXPORT_SYMBOL(free_reserved_area
);
6774 #ifdef CONFIG_HIGHMEM
6775 void free_highmem_page(struct page
*page
)
6777 __free_reserved_page(page
);
6779 page_zone(page
)->managed_pages
++;
6785 void __init
mem_init_print_info(const char *str
)
6787 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6788 unsigned long init_code_size
, init_data_size
;
6790 physpages
= get_num_physpages();
6791 codesize
= _etext
- _stext
;
6792 datasize
= _edata
- _sdata
;
6793 rosize
= __end_rodata
- __start_rodata
;
6794 bss_size
= __bss_stop
- __bss_start
;
6795 init_data_size
= __init_end
- __init_begin
;
6796 init_code_size
= _einittext
- _sinittext
;
6799 * Detect special cases and adjust section sizes accordingly:
6800 * 1) .init.* may be embedded into .data sections
6801 * 2) .init.text.* may be out of [__init_begin, __init_end],
6802 * please refer to arch/tile/kernel/vmlinux.lds.S.
6803 * 3) .rodata.* may be embedded into .text or .data sections.
6805 #define adj_init_size(start, end, size, pos, adj) \
6807 if (start <= pos && pos < end && size > adj) \
6811 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6812 _sinittext
, init_code_size
);
6813 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6814 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6815 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6816 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6818 #undef adj_init_size
6820 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6821 #ifdef CONFIG_HIGHMEM
6825 nr_free_pages() << (PAGE_SHIFT
- 10),
6826 physpages
<< (PAGE_SHIFT
- 10),
6827 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6828 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6829 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6830 totalcma_pages
<< (PAGE_SHIFT
- 10),
6831 #ifdef CONFIG_HIGHMEM
6832 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6834 str
? ", " : "", str
? str
: "");
6838 * set_dma_reserve - set the specified number of pages reserved in the first zone
6839 * @new_dma_reserve: The number of pages to mark reserved
6841 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6842 * In the DMA zone, a significant percentage may be consumed by kernel image
6843 * and other unfreeable allocations which can skew the watermarks badly. This
6844 * function may optionally be used to account for unfreeable pages in the
6845 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6846 * smaller per-cpu batchsize.
6848 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6850 dma_reserve
= new_dma_reserve
;
6853 void __init
free_area_init(unsigned long *zones_size
)
6855 free_area_init_node(0, zones_size
,
6856 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6859 static int page_alloc_cpu_dead(unsigned int cpu
)
6862 lru_add_drain_cpu(cpu
);
6866 * Spill the event counters of the dead processor
6867 * into the current processors event counters.
6868 * This artificially elevates the count of the current
6871 vm_events_fold_cpu(cpu
);
6874 * Zero the differential counters of the dead processor
6875 * so that the vm statistics are consistent.
6877 * This is only okay since the processor is dead and cannot
6878 * race with what we are doing.
6880 cpu_vm_stats_fold(cpu
);
6884 void __init
page_alloc_init(void)
6888 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
6889 "mm/page_alloc:dead", NULL
,
6890 page_alloc_cpu_dead
);
6895 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6896 * or min_free_kbytes changes.
6898 static void calculate_totalreserve_pages(void)
6900 struct pglist_data
*pgdat
;
6901 unsigned long reserve_pages
= 0;
6902 enum zone_type i
, j
;
6904 for_each_online_pgdat(pgdat
) {
6906 pgdat
->totalreserve_pages
= 0;
6908 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6909 struct zone
*zone
= pgdat
->node_zones
+ i
;
6912 /* Find valid and maximum lowmem_reserve in the zone */
6913 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6914 if (zone
->lowmem_reserve
[j
] > max
)
6915 max
= zone
->lowmem_reserve
[j
];
6918 /* we treat the high watermark as reserved pages. */
6919 max
+= high_wmark_pages(zone
);
6921 if (max
> zone
->managed_pages
)
6922 max
= zone
->managed_pages
;
6924 pgdat
->totalreserve_pages
+= max
;
6926 reserve_pages
+= max
;
6929 totalreserve_pages
= reserve_pages
;
6933 * setup_per_zone_lowmem_reserve - called whenever
6934 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6935 * has a correct pages reserved value, so an adequate number of
6936 * pages are left in the zone after a successful __alloc_pages().
6938 static void setup_per_zone_lowmem_reserve(void)
6940 struct pglist_data
*pgdat
;
6941 enum zone_type j
, idx
;
6943 for_each_online_pgdat(pgdat
) {
6944 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6945 struct zone
*zone
= pgdat
->node_zones
+ j
;
6946 unsigned long managed_pages
= zone
->managed_pages
;
6948 zone
->lowmem_reserve
[j
] = 0;
6952 struct zone
*lower_zone
;
6956 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6957 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6959 lower_zone
= pgdat
->node_zones
+ idx
;
6960 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6961 sysctl_lowmem_reserve_ratio
[idx
];
6962 managed_pages
+= lower_zone
->managed_pages
;
6967 /* update totalreserve_pages */
6968 calculate_totalreserve_pages();
6971 static void __setup_per_zone_wmarks(void)
6973 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6974 unsigned long lowmem_pages
= 0;
6976 unsigned long flags
;
6978 /* Calculate total number of !ZONE_HIGHMEM pages */
6979 for_each_zone(zone
) {
6980 if (!is_highmem(zone
))
6981 lowmem_pages
+= zone
->managed_pages
;
6984 for_each_zone(zone
) {
6987 spin_lock_irqsave(&zone
->lock
, flags
);
6988 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6989 do_div(tmp
, lowmem_pages
);
6990 if (is_highmem(zone
)) {
6992 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6993 * need highmem pages, so cap pages_min to a small
6996 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6997 * deltas control asynch page reclaim, and so should
6998 * not be capped for highmem.
7000 unsigned long min_pages
;
7002 min_pages
= zone
->managed_pages
/ 1024;
7003 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7004 zone
->watermark
[WMARK_MIN
] = min_pages
;
7007 * If it's a lowmem zone, reserve a number of pages
7008 * proportionate to the zone's size.
7010 zone
->watermark
[WMARK_MIN
] = tmp
;
7014 * Set the kswapd watermarks distance according to the
7015 * scale factor in proportion to available memory, but
7016 * ensure a minimum size on small systems.
7018 tmp
= max_t(u64
, tmp
>> 2,
7019 mult_frac(zone
->managed_pages
,
7020 watermark_scale_factor
, 10000));
7022 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7023 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7025 spin_unlock_irqrestore(&zone
->lock
, flags
);
7028 /* update totalreserve_pages */
7029 calculate_totalreserve_pages();
7033 * setup_per_zone_wmarks - called when min_free_kbytes changes
7034 * or when memory is hot-{added|removed}
7036 * Ensures that the watermark[min,low,high] values for each zone are set
7037 * correctly with respect to min_free_kbytes.
7039 void setup_per_zone_wmarks(void)
7041 mutex_lock(&zonelists_mutex
);
7042 __setup_per_zone_wmarks();
7043 mutex_unlock(&zonelists_mutex
);
7047 * Initialise min_free_kbytes.
7049 * For small machines we want it small (128k min). For large machines
7050 * we want it large (64MB max). But it is not linear, because network
7051 * bandwidth does not increase linearly with machine size. We use
7053 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7054 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7070 int __meminit
init_per_zone_wmark_min(void)
7072 unsigned long lowmem_kbytes
;
7073 int new_min_free_kbytes
;
7075 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7076 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7078 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7079 min_free_kbytes
= new_min_free_kbytes
;
7080 if (min_free_kbytes
< 128)
7081 min_free_kbytes
= 128;
7082 if (min_free_kbytes
> 65536)
7083 min_free_kbytes
= 65536;
7085 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7086 new_min_free_kbytes
, user_min_free_kbytes
);
7088 setup_per_zone_wmarks();
7089 refresh_zone_stat_thresholds();
7090 setup_per_zone_lowmem_reserve();
7093 setup_min_unmapped_ratio();
7094 setup_min_slab_ratio();
7099 core_initcall(init_per_zone_wmark_min
)
7102 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7103 * that we can call two helper functions whenever min_free_kbytes
7106 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7107 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7111 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7116 user_min_free_kbytes
= min_free_kbytes
;
7117 setup_per_zone_wmarks();
7122 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7123 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7127 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7132 setup_per_zone_wmarks();
7138 static void setup_min_unmapped_ratio(void)
7143 for_each_online_pgdat(pgdat
)
7144 pgdat
->min_unmapped_pages
= 0;
7147 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
7148 sysctl_min_unmapped_ratio
) / 100;
7152 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7153 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7157 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7161 setup_min_unmapped_ratio();
7166 static void setup_min_slab_ratio(void)
7171 for_each_online_pgdat(pgdat
)
7172 pgdat
->min_slab_pages
= 0;
7175 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
7176 sysctl_min_slab_ratio
) / 100;
7179 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7180 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7184 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7188 setup_min_slab_ratio();
7195 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7196 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7197 * whenever sysctl_lowmem_reserve_ratio changes.
7199 * The reserve ratio obviously has absolutely no relation with the
7200 * minimum watermarks. The lowmem reserve ratio can only make sense
7201 * if in function of the boot time zone sizes.
7203 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7204 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7206 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7207 setup_per_zone_lowmem_reserve();
7212 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7213 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7214 * pagelist can have before it gets flushed back to buddy allocator.
7216 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7217 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7220 int old_percpu_pagelist_fraction
;
7223 mutex_lock(&pcp_batch_high_lock
);
7224 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7226 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7227 if (!write
|| ret
< 0)
7230 /* Sanity checking to avoid pcp imbalance */
7231 if (percpu_pagelist_fraction
&&
7232 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7233 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7239 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7242 for_each_populated_zone(zone
) {
7245 for_each_possible_cpu(cpu
)
7246 pageset_set_high_and_batch(zone
,
7247 per_cpu_ptr(zone
->pageset
, cpu
));
7250 mutex_unlock(&pcp_batch_high_lock
);
7255 int hashdist
= HASHDIST_DEFAULT
;
7257 static int __init
set_hashdist(char *str
)
7261 hashdist
= simple_strtoul(str
, &str
, 0);
7264 __setup("hashdist=", set_hashdist
);
7267 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7269 * Returns the number of pages that arch has reserved but
7270 * is not known to alloc_large_system_hash().
7272 static unsigned long __init
arch_reserved_kernel_pages(void)
7279 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7280 * machines. As memory size is increased the scale is also increased but at
7281 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7282 * quadruples the scale is increased by one, which means the size of hash table
7283 * only doubles, instead of quadrupling as well.
7284 * Because 32-bit systems cannot have large physical memory, where this scaling
7285 * makes sense, it is disabled on such platforms.
7287 #if __BITS_PER_LONG > 32
7288 #define ADAPT_SCALE_BASE (64ul << 30)
7289 #define ADAPT_SCALE_SHIFT 2
7290 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7294 * allocate a large system hash table from bootmem
7295 * - it is assumed that the hash table must contain an exact power-of-2
7296 * quantity of entries
7297 * - limit is the number of hash buckets, not the total allocation size
7299 void *__init
alloc_large_system_hash(const char *tablename
,
7300 unsigned long bucketsize
,
7301 unsigned long numentries
,
7304 unsigned int *_hash_shift
,
7305 unsigned int *_hash_mask
,
7306 unsigned long low_limit
,
7307 unsigned long high_limit
)
7309 unsigned long long max
= high_limit
;
7310 unsigned long log2qty
, size
;
7314 /* allow the kernel cmdline to have a say */
7316 /* round applicable memory size up to nearest megabyte */
7317 numentries
= nr_kernel_pages
;
7318 numentries
-= arch_reserved_kernel_pages();
7320 /* It isn't necessary when PAGE_SIZE >= 1MB */
7321 if (PAGE_SHIFT
< 20)
7322 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7324 #if __BITS_PER_LONG > 32
7326 unsigned long adapt
;
7328 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
7329 adapt
<<= ADAPT_SCALE_SHIFT
)
7334 /* limit to 1 bucket per 2^scale bytes of low memory */
7335 if (scale
> PAGE_SHIFT
)
7336 numentries
>>= (scale
- PAGE_SHIFT
);
7338 numentries
<<= (PAGE_SHIFT
- scale
);
7340 /* Make sure we've got at least a 0-order allocation.. */
7341 if (unlikely(flags
& HASH_SMALL
)) {
7342 /* Makes no sense without HASH_EARLY */
7343 WARN_ON(!(flags
& HASH_EARLY
));
7344 if (!(numentries
>> *_hash_shift
)) {
7345 numentries
= 1UL << *_hash_shift
;
7346 BUG_ON(!numentries
);
7348 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7349 numentries
= PAGE_SIZE
/ bucketsize
;
7351 numentries
= roundup_pow_of_two(numentries
);
7353 /* limit allocation size to 1/16 total memory by default */
7355 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7356 do_div(max
, bucketsize
);
7358 max
= min(max
, 0x80000000ULL
);
7360 if (numentries
< low_limit
)
7361 numentries
= low_limit
;
7362 if (numentries
> max
)
7365 log2qty
= ilog2(numentries
);
7368 * memblock allocator returns zeroed memory already, so HASH_ZERO is
7369 * currently not used when HASH_EARLY is specified.
7371 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
7373 size
= bucketsize
<< log2qty
;
7374 if (flags
& HASH_EARLY
)
7375 table
= memblock_virt_alloc_nopanic(size
, 0);
7377 table
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
7380 * If bucketsize is not a power-of-two, we may free
7381 * some pages at the end of hash table which
7382 * alloc_pages_exact() automatically does
7384 if (get_order(size
) < MAX_ORDER
) {
7385 table
= alloc_pages_exact(size
, gfp_flags
);
7386 kmemleak_alloc(table
, size
, 1, gfp_flags
);
7389 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7392 panic("Failed to allocate %s hash table\n", tablename
);
7394 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7395 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7398 *_hash_shift
= log2qty
;
7400 *_hash_mask
= (1 << log2qty
) - 1;
7406 * This function checks whether pageblock includes unmovable pages or not.
7407 * If @count is not zero, it is okay to include less @count unmovable pages
7409 * PageLRU check without isolation or lru_lock could race so that
7410 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7411 * check without lock_page also may miss some movable non-lru pages at
7412 * race condition. So you can't expect this function should be exact.
7414 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7415 bool skip_hwpoisoned_pages
)
7417 unsigned long pfn
, iter
, found
;
7421 * For avoiding noise data, lru_add_drain_all() should be called
7422 * If ZONE_MOVABLE, the zone never contains unmovable pages
7424 if (zone_idx(zone
) == ZONE_MOVABLE
)
7426 mt
= get_pageblock_migratetype(page
);
7427 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7430 pfn
= page_to_pfn(page
);
7431 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7432 unsigned long check
= pfn
+ iter
;
7434 if (!pfn_valid_within(check
))
7437 page
= pfn_to_page(check
);
7440 * Hugepages are not in LRU lists, but they're movable.
7441 * We need not scan over tail pages bacause we don't
7442 * handle each tail page individually in migration.
7444 if (PageHuge(page
)) {
7445 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7450 * We can't use page_count without pin a page
7451 * because another CPU can free compound page.
7452 * This check already skips compound tails of THP
7453 * because their page->_refcount is zero at all time.
7455 if (!page_ref_count(page
)) {
7456 if (PageBuddy(page
))
7457 iter
+= (1 << page_order(page
)) - 1;
7462 * The HWPoisoned page may be not in buddy system, and
7463 * page_count() is not 0.
7465 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7468 if (__PageMovable(page
))
7474 * If there are RECLAIMABLE pages, we need to check
7475 * it. But now, memory offline itself doesn't call
7476 * shrink_node_slabs() and it still to be fixed.
7479 * If the page is not RAM, page_count()should be 0.
7480 * we don't need more check. This is an _used_ not-movable page.
7482 * The problematic thing here is PG_reserved pages. PG_reserved
7483 * is set to both of a memory hole page and a _used_ kernel
7492 bool is_pageblock_removable_nolock(struct page
*page
)
7498 * We have to be careful here because we are iterating over memory
7499 * sections which are not zone aware so we might end up outside of
7500 * the zone but still within the section.
7501 * We have to take care about the node as well. If the node is offline
7502 * its NODE_DATA will be NULL - see page_zone.
7504 if (!node_online(page_to_nid(page
)))
7507 zone
= page_zone(page
);
7508 pfn
= page_to_pfn(page
);
7509 if (!zone_spans_pfn(zone
, pfn
))
7512 return !has_unmovable_pages(zone
, page
, 0, true);
7515 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7517 static unsigned long pfn_max_align_down(unsigned long pfn
)
7519 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7520 pageblock_nr_pages
) - 1);
7523 static unsigned long pfn_max_align_up(unsigned long pfn
)
7525 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7526 pageblock_nr_pages
));
7529 /* [start, end) must belong to a single zone. */
7530 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7531 unsigned long start
, unsigned long end
)
7533 /* This function is based on compact_zone() from compaction.c. */
7534 unsigned long nr_reclaimed
;
7535 unsigned long pfn
= start
;
7536 unsigned int tries
= 0;
7541 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7542 if (fatal_signal_pending(current
)) {
7547 if (list_empty(&cc
->migratepages
)) {
7548 cc
->nr_migratepages
= 0;
7549 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7555 } else if (++tries
== 5) {
7556 ret
= ret
< 0 ? ret
: -EBUSY
;
7560 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7562 cc
->nr_migratepages
-= nr_reclaimed
;
7564 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7565 NULL
, 0, cc
->mode
, MR_CMA
);
7568 putback_movable_pages(&cc
->migratepages
);
7575 * alloc_contig_range() -- tries to allocate given range of pages
7576 * @start: start PFN to allocate
7577 * @end: one-past-the-last PFN to allocate
7578 * @migratetype: migratetype of the underlaying pageblocks (either
7579 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7580 * in range must have the same migratetype and it must
7581 * be either of the two.
7582 * @gfp_mask: GFP mask to use during compaction
7584 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7585 * aligned, however it's the caller's responsibility to guarantee that
7586 * we are the only thread that changes migrate type of pageblocks the
7589 * The PFN range must belong to a single zone.
7591 * Returns zero on success or negative error code. On success all
7592 * pages which PFN is in [start, end) are allocated for the caller and
7593 * need to be freed with free_contig_range().
7595 int alloc_contig_range(unsigned long start
, unsigned long end
,
7596 unsigned migratetype
, gfp_t gfp_mask
)
7598 unsigned long outer_start
, outer_end
;
7602 struct compact_control cc
= {
7603 .nr_migratepages
= 0,
7605 .zone
= page_zone(pfn_to_page(start
)),
7606 .mode
= MIGRATE_SYNC
,
7607 .ignore_skip_hint
= true,
7608 .gfp_mask
= current_gfp_context(gfp_mask
),
7610 INIT_LIST_HEAD(&cc
.migratepages
);
7613 * What we do here is we mark all pageblocks in range as
7614 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7615 * have different sizes, and due to the way page allocator
7616 * work, we align the range to biggest of the two pages so
7617 * that page allocator won't try to merge buddies from
7618 * different pageblocks and change MIGRATE_ISOLATE to some
7619 * other migration type.
7621 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7622 * migrate the pages from an unaligned range (ie. pages that
7623 * we are interested in). This will put all the pages in
7624 * range back to page allocator as MIGRATE_ISOLATE.
7626 * When this is done, we take the pages in range from page
7627 * allocator removing them from the buddy system. This way
7628 * page allocator will never consider using them.
7630 * This lets us mark the pageblocks back as
7631 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7632 * aligned range but not in the unaligned, original range are
7633 * put back to page allocator so that buddy can use them.
7636 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7637 pfn_max_align_up(end
), migratetype
,
7643 * In case of -EBUSY, we'd like to know which page causes problem.
7644 * So, just fall through. We will check it in test_pages_isolated().
7646 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7647 if (ret
&& ret
!= -EBUSY
)
7651 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7652 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7653 * more, all pages in [start, end) are free in page allocator.
7654 * What we are going to do is to allocate all pages from
7655 * [start, end) (that is remove them from page allocator).
7657 * The only problem is that pages at the beginning and at the
7658 * end of interesting range may be not aligned with pages that
7659 * page allocator holds, ie. they can be part of higher order
7660 * pages. Because of this, we reserve the bigger range and
7661 * once this is done free the pages we are not interested in.
7663 * We don't have to hold zone->lock here because the pages are
7664 * isolated thus they won't get removed from buddy.
7667 lru_add_drain_all();
7668 drain_all_pages(cc
.zone
);
7671 outer_start
= start
;
7672 while (!PageBuddy(pfn_to_page(outer_start
))) {
7673 if (++order
>= MAX_ORDER
) {
7674 outer_start
= start
;
7677 outer_start
&= ~0UL << order
;
7680 if (outer_start
!= start
) {
7681 order
= page_order(pfn_to_page(outer_start
));
7684 * outer_start page could be small order buddy page and
7685 * it doesn't include start page. Adjust outer_start
7686 * in this case to report failed page properly
7687 * on tracepoint in test_pages_isolated()
7689 if (outer_start
+ (1UL << order
) <= start
)
7690 outer_start
= start
;
7693 /* Make sure the range is really isolated. */
7694 if (test_pages_isolated(outer_start
, end
, false)) {
7699 /* Grab isolated pages from freelists. */
7700 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7706 /* Free head and tail (if any) */
7707 if (start
!= outer_start
)
7708 free_contig_range(outer_start
, start
- outer_start
);
7709 if (end
!= outer_end
)
7710 free_contig_range(end
, outer_end
- end
);
7713 undo_isolate_page_range(pfn_max_align_down(start
),
7714 pfn_max_align_up(end
), migratetype
);
7718 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7720 unsigned int count
= 0;
7722 for (; nr_pages
--; pfn
++) {
7723 struct page
*page
= pfn_to_page(pfn
);
7725 count
+= page_count(page
) != 1;
7728 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7732 #ifdef CONFIG_MEMORY_HOTPLUG
7734 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7735 * page high values need to be recalulated.
7737 void __meminit
zone_pcp_update(struct zone
*zone
)
7740 mutex_lock(&pcp_batch_high_lock
);
7741 for_each_possible_cpu(cpu
)
7742 pageset_set_high_and_batch(zone
,
7743 per_cpu_ptr(zone
->pageset
, cpu
));
7744 mutex_unlock(&pcp_batch_high_lock
);
7748 void zone_pcp_reset(struct zone
*zone
)
7750 unsigned long flags
;
7752 struct per_cpu_pageset
*pset
;
7754 /* avoid races with drain_pages() */
7755 local_irq_save(flags
);
7756 if (zone
->pageset
!= &boot_pageset
) {
7757 for_each_online_cpu(cpu
) {
7758 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7759 drain_zonestat(zone
, pset
);
7761 free_percpu(zone
->pageset
);
7762 zone
->pageset
= &boot_pageset
;
7764 local_irq_restore(flags
);
7767 #ifdef CONFIG_MEMORY_HOTREMOVE
7769 * All pages in the range must be in a single zone and isolated
7770 * before calling this.
7773 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7777 unsigned int order
, i
;
7779 unsigned long flags
;
7780 /* find the first valid pfn */
7781 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7786 offline_mem_sections(pfn
, end_pfn
);
7787 zone
= page_zone(pfn_to_page(pfn
));
7788 spin_lock_irqsave(&zone
->lock
, flags
);
7790 while (pfn
< end_pfn
) {
7791 if (!pfn_valid(pfn
)) {
7795 page
= pfn_to_page(pfn
);
7797 * The HWPoisoned page may be not in buddy system, and
7798 * page_count() is not 0.
7800 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7802 SetPageReserved(page
);
7806 BUG_ON(page_count(page
));
7807 BUG_ON(!PageBuddy(page
));
7808 order
= page_order(page
);
7809 #ifdef CONFIG_DEBUG_VM
7810 pr_info("remove from free list %lx %d %lx\n",
7811 pfn
, 1 << order
, end_pfn
);
7813 list_del(&page
->lru
);
7814 rmv_page_order(page
);
7815 zone
->free_area
[order
].nr_free
--;
7816 for (i
= 0; i
< (1 << order
); i
++)
7817 SetPageReserved((page
+i
));
7818 pfn
+= (1 << order
);
7820 spin_unlock_irqrestore(&zone
->lock
, flags
);
7824 bool is_free_buddy_page(struct page
*page
)
7826 struct zone
*zone
= page_zone(page
);
7827 unsigned long pfn
= page_to_pfn(page
);
7828 unsigned long flags
;
7831 spin_lock_irqsave(&zone
->lock
, flags
);
7832 for (order
= 0; order
< MAX_ORDER
; order
++) {
7833 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7835 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7838 spin_unlock_irqrestore(&zone
->lock
, flags
);
7840 return order
< MAX_ORDER
;