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/kasan.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/memremap.h>
46 #include <linux/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <trace/events/oom.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/sched/mm.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66 #include <linux/memcontrol.h>
67 #include <linux/ftrace.h>
68 #include <linux/lockdep.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
294 * Determine how many pages need to be initialized durig early boot
295 * (non-deferred initialization).
296 * The value of first_deferred_pfn will be set later, once non-deferred pages
297 * are initialized, but for now set it ULONG_MAX.
299 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
301 phys_addr_t start_addr
, end_addr
;
302 unsigned long max_pgcnt
;
303 unsigned long reserved
;
306 * Initialise at least 2G of a node but also take into account that
307 * two large system hashes that can take up 1GB for 0.25TB/node.
309 max_pgcnt
= max(2UL << (30 - PAGE_SHIFT
),
310 (pgdat
->node_spanned_pages
>> 8));
313 * Compensate the all the memblock reservations (e.g. crash kernel)
314 * from the initial estimation to make sure we will initialize enough
317 start_addr
= PFN_PHYS(pgdat
->node_start_pfn
);
318 end_addr
= PFN_PHYS(pgdat
->node_start_pfn
+ max_pgcnt
);
319 reserved
= memblock_reserved_memory_within(start_addr
, end_addr
);
320 max_pgcnt
+= PHYS_PFN(reserved
);
322 pgdat
->static_init_pgcnt
= min(max_pgcnt
, pgdat
->node_spanned_pages
);
323 pgdat
->first_deferred_pfn
= ULONG_MAX
;
326 /* Returns true if the struct page for the pfn is uninitialised */
327 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
329 int nid
= early_pfn_to_nid(pfn
);
331 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
338 * Returns false when the remaining initialisation should be deferred until
339 * later in the boot cycle when it can be parallelised.
341 static inline bool update_defer_init(pg_data_t
*pgdat
,
342 unsigned long pfn
, unsigned long zone_end
,
343 unsigned long *nr_initialised
)
345 /* Always populate low zones for address-contrained allocations */
346 if (zone_end
< pgdat_end_pfn(pgdat
))
349 if ((*nr_initialised
> pgdat
->static_init_pgcnt
) &&
350 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
351 pgdat
->first_deferred_pfn
= pfn
;
358 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
362 static inline bool early_page_uninitialised(unsigned long pfn
)
367 static inline bool update_defer_init(pg_data_t
*pgdat
,
368 unsigned long pfn
, unsigned long zone_end
,
369 unsigned long *nr_initialised
)
375 /* Return a pointer to the bitmap storing bits affecting a block of pages */
376 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
379 #ifdef CONFIG_SPARSEMEM
380 return __pfn_to_section(pfn
)->pageblock_flags
;
382 return page_zone(page
)->pageblock_flags
;
383 #endif /* CONFIG_SPARSEMEM */
386 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
388 #ifdef CONFIG_SPARSEMEM
389 pfn
&= (PAGES_PER_SECTION
-1);
390 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
392 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
393 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
394 #endif /* CONFIG_SPARSEMEM */
398 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
399 * @page: The page within the block of interest
400 * @pfn: The target page frame number
401 * @end_bitidx: The last bit of interest to retrieve
402 * @mask: mask of bits that the caller is interested in
404 * Return: pageblock_bits flags
406 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
408 unsigned long end_bitidx
,
411 unsigned long *bitmap
;
412 unsigned long bitidx
, word_bitidx
;
415 bitmap
= get_pageblock_bitmap(page
, pfn
);
416 bitidx
= pfn_to_bitidx(page
, pfn
);
417 word_bitidx
= bitidx
/ BITS_PER_LONG
;
418 bitidx
&= (BITS_PER_LONG
-1);
420 word
= bitmap
[word_bitidx
];
421 bitidx
+= end_bitidx
;
422 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
425 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
426 unsigned long end_bitidx
,
429 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
432 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
434 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
438 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
439 * @page: The page within the block of interest
440 * @flags: The flags to set
441 * @pfn: The target page frame number
442 * @end_bitidx: The last bit of interest
443 * @mask: mask of bits that the caller is interested in
445 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
447 unsigned long end_bitidx
,
450 unsigned long *bitmap
;
451 unsigned long bitidx
, word_bitidx
;
452 unsigned long old_word
, word
;
454 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
456 bitmap
= get_pageblock_bitmap(page
, pfn
);
457 bitidx
= pfn_to_bitidx(page
, pfn
);
458 word_bitidx
= bitidx
/ BITS_PER_LONG
;
459 bitidx
&= (BITS_PER_LONG
-1);
461 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
463 bitidx
+= end_bitidx
;
464 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
465 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
467 word
= READ_ONCE(bitmap
[word_bitidx
]);
469 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
470 if (word
== old_word
)
476 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
478 if (unlikely(page_group_by_mobility_disabled
&&
479 migratetype
< MIGRATE_PCPTYPES
))
480 migratetype
= MIGRATE_UNMOVABLE
;
482 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
483 PB_migrate
, PB_migrate_end
);
486 #ifdef CONFIG_DEBUG_VM
487 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
491 unsigned long pfn
= page_to_pfn(page
);
492 unsigned long sp
, start_pfn
;
495 seq
= zone_span_seqbegin(zone
);
496 start_pfn
= zone
->zone_start_pfn
;
497 sp
= zone
->spanned_pages
;
498 if (!zone_spans_pfn(zone
, pfn
))
500 } while (zone_span_seqretry(zone
, seq
));
503 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
504 pfn
, zone_to_nid(zone
), zone
->name
,
505 start_pfn
, start_pfn
+ sp
);
510 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
512 if (!pfn_valid_within(page_to_pfn(page
)))
514 if (zone
!= page_zone(page
))
520 * Temporary debugging check for pages not lying within a given zone.
522 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
524 if (page_outside_zone_boundaries(zone
, page
))
526 if (!page_is_consistent(zone
, page
))
532 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
538 static void bad_page(struct page
*page
, const char *reason
,
539 unsigned long bad_flags
)
541 static unsigned long resume
;
542 static unsigned long nr_shown
;
543 static unsigned long nr_unshown
;
546 * Allow a burst of 60 reports, then keep quiet for that minute;
547 * or allow a steady drip of one report per second.
549 if (nr_shown
== 60) {
550 if (time_before(jiffies
, resume
)) {
556 "BUG: Bad page state: %lu messages suppressed\n",
563 resume
= jiffies
+ 60 * HZ
;
565 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
566 current
->comm
, page_to_pfn(page
));
567 __dump_page(page
, reason
);
568 bad_flags
&= page
->flags
;
570 pr_alert("bad because of flags: %#lx(%pGp)\n",
571 bad_flags
, &bad_flags
);
572 dump_page_owner(page
);
577 /* Leave bad fields for debug, except PageBuddy could make trouble */
578 page_mapcount_reset(page
); /* remove PageBuddy */
579 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
583 * Higher-order pages are called "compound pages". They are structured thusly:
585 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
587 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
588 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
590 * The first tail page's ->compound_dtor holds the offset in array of compound
591 * page destructors. See compound_page_dtors.
593 * The first tail page's ->compound_order holds the order of allocation.
594 * This usage means that zero-order pages may not be compound.
597 void free_compound_page(struct page
*page
)
599 __free_pages_ok(page
, compound_order(page
));
602 void prep_compound_page(struct page
*page
, unsigned int order
)
605 int nr_pages
= 1 << order
;
607 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
608 set_compound_order(page
, order
);
610 for (i
= 1; i
< nr_pages
; i
++) {
611 struct page
*p
= page
+ i
;
612 set_page_count(p
, 0);
613 p
->mapping
= TAIL_MAPPING
;
614 set_compound_head(p
, page
);
616 atomic_set(compound_mapcount_ptr(page
), -1);
619 #ifdef CONFIG_DEBUG_PAGEALLOC
620 unsigned int _debug_guardpage_minorder
;
621 bool _debug_pagealloc_enabled __read_mostly
622 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
623 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
624 bool _debug_guardpage_enabled __read_mostly
;
626 static int __init
early_debug_pagealloc(char *buf
)
630 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
632 early_param("debug_pagealloc", early_debug_pagealloc
);
634 static bool need_debug_guardpage(void)
636 /* If we don't use debug_pagealloc, we don't need guard page */
637 if (!debug_pagealloc_enabled())
640 if (!debug_guardpage_minorder())
646 static void init_debug_guardpage(void)
648 if (!debug_pagealloc_enabled())
651 if (!debug_guardpage_minorder())
654 _debug_guardpage_enabled
= true;
657 struct page_ext_operations debug_guardpage_ops
= {
658 .need
= need_debug_guardpage
,
659 .init
= init_debug_guardpage
,
662 static int __init
debug_guardpage_minorder_setup(char *buf
)
666 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
667 pr_err("Bad debug_guardpage_minorder value\n");
670 _debug_guardpage_minorder
= res
;
671 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
674 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
676 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
677 unsigned int order
, int migratetype
)
679 struct page_ext
*page_ext
;
681 if (!debug_guardpage_enabled())
684 if (order
>= debug_guardpage_minorder())
687 page_ext
= lookup_page_ext(page
);
688 if (unlikely(!page_ext
))
691 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
693 INIT_LIST_HEAD(&page
->lru
);
694 set_page_private(page
, order
);
695 /* Guard pages are not available for any usage */
696 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
701 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
702 unsigned int order
, int migratetype
)
704 struct page_ext
*page_ext
;
706 if (!debug_guardpage_enabled())
709 page_ext
= lookup_page_ext(page
);
710 if (unlikely(!page_ext
))
713 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
715 set_page_private(page
, 0);
716 if (!is_migrate_isolate(migratetype
))
717 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
720 struct page_ext_operations debug_guardpage_ops
;
721 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
722 unsigned int order
, int migratetype
) { return false; }
723 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
724 unsigned int order
, int migratetype
) {}
727 static inline void set_page_order(struct page
*page
, unsigned int order
)
729 set_page_private(page
, order
);
730 __SetPageBuddy(page
);
733 static inline void rmv_page_order(struct page
*page
)
735 __ClearPageBuddy(page
);
736 set_page_private(page
, 0);
740 * This function checks whether a page is free && is the buddy
741 * we can do coalesce a page and its buddy if
742 * (a) the buddy is not in a hole (check before calling!) &&
743 * (b) the buddy is in the buddy system &&
744 * (c) a page and its buddy have the same order &&
745 * (d) a page and its buddy are in the same zone.
747 * For recording whether a page is in the buddy system, we set ->_mapcount
748 * PAGE_BUDDY_MAPCOUNT_VALUE.
749 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
750 * serialized by zone->lock.
752 * For recording page's order, we use page_private(page).
754 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
757 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
758 if (page_zone_id(page
) != page_zone_id(buddy
))
761 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
766 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
768 * zone check is done late to avoid uselessly
769 * calculating zone/node ids for pages that could
772 if (page_zone_id(page
) != page_zone_id(buddy
))
775 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
783 * Freeing function for a buddy system allocator.
785 * The concept of a buddy system is to maintain direct-mapped table
786 * (containing bit values) for memory blocks of various "orders".
787 * The bottom level table contains the map for the smallest allocatable
788 * units of memory (here, pages), and each level above it describes
789 * pairs of units from the levels below, hence, "buddies".
790 * At a high level, all that happens here is marking the table entry
791 * at the bottom level available, and propagating the changes upward
792 * as necessary, plus some accounting needed to play nicely with other
793 * parts of the VM system.
794 * At each level, we keep a list of pages, which are heads of continuous
795 * free pages of length of (1 << order) and marked with _mapcount
796 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
798 * So when we are allocating or freeing one, we can derive the state of the
799 * other. That is, if we allocate a small block, and both were
800 * free, the remainder of the region must be split into blocks.
801 * If a block is freed, and its buddy is also free, then this
802 * triggers coalescing into a block of larger size.
807 static inline void __free_one_page(struct page
*page
,
809 struct zone
*zone
, unsigned int order
,
812 unsigned long combined_pfn
;
813 unsigned long uninitialized_var(buddy_pfn
);
815 unsigned int max_order
;
817 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
819 VM_BUG_ON(!zone_is_initialized(zone
));
820 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
822 VM_BUG_ON(migratetype
== -1);
823 if (likely(!is_migrate_isolate(migratetype
)))
824 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
826 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
827 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
830 while (order
< max_order
- 1) {
831 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
832 buddy
= page
+ (buddy_pfn
- pfn
);
834 if (!pfn_valid_within(buddy_pfn
))
836 if (!page_is_buddy(page
, buddy
, order
))
839 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
840 * merge with it and move up one order.
842 if (page_is_guard(buddy
)) {
843 clear_page_guard(zone
, buddy
, order
, migratetype
);
845 list_del(&buddy
->lru
);
846 zone
->free_area
[order
].nr_free
--;
847 rmv_page_order(buddy
);
849 combined_pfn
= buddy_pfn
& pfn
;
850 page
= page
+ (combined_pfn
- pfn
);
854 if (max_order
< MAX_ORDER
) {
855 /* If we are here, it means order is >= pageblock_order.
856 * We want to prevent merge between freepages on isolate
857 * pageblock and normal pageblock. Without this, pageblock
858 * isolation could cause incorrect freepage or CMA accounting.
860 * We don't want to hit this code for the more frequent
863 if (unlikely(has_isolate_pageblock(zone
))) {
866 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
867 buddy
= page
+ (buddy_pfn
- pfn
);
868 buddy_mt
= get_pageblock_migratetype(buddy
);
870 if (migratetype
!= buddy_mt
871 && (is_migrate_isolate(migratetype
) ||
872 is_migrate_isolate(buddy_mt
)))
876 goto continue_merging
;
880 set_page_order(page
, order
);
883 * If this is not the largest possible page, check if the buddy
884 * of the next-highest order is free. If it is, it's possible
885 * that pages are being freed that will coalesce soon. In case,
886 * that is happening, add the free page to the tail of the list
887 * so it's less likely to be used soon and more likely to be merged
888 * as a higher order page
890 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)) {
891 struct page
*higher_page
, *higher_buddy
;
892 combined_pfn
= buddy_pfn
& pfn
;
893 higher_page
= page
+ (combined_pfn
- pfn
);
894 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
895 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
896 if (pfn_valid_within(buddy_pfn
) &&
897 page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
898 list_add_tail(&page
->lru
,
899 &zone
->free_area
[order
].free_list
[migratetype
]);
904 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
906 zone
->free_area
[order
].nr_free
++;
910 * A bad page could be due to a number of fields. Instead of multiple branches,
911 * try and check multiple fields with one check. The caller must do a detailed
912 * check if necessary.
914 static inline bool page_expected_state(struct page
*page
,
915 unsigned long check_flags
)
917 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
920 if (unlikely((unsigned long)page
->mapping
|
921 page_ref_count(page
) |
923 (unsigned long)page
->mem_cgroup
|
925 (page
->flags
& check_flags
)))
931 static void free_pages_check_bad(struct page
*page
)
933 const char *bad_reason
;
934 unsigned long bad_flags
;
939 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
940 bad_reason
= "nonzero mapcount";
941 if (unlikely(page
->mapping
!= NULL
))
942 bad_reason
= "non-NULL mapping";
943 if (unlikely(page_ref_count(page
) != 0))
944 bad_reason
= "nonzero _refcount";
945 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
946 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
947 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
950 if (unlikely(page
->mem_cgroup
))
951 bad_reason
= "page still charged to cgroup";
953 bad_page(page
, bad_reason
, bad_flags
);
956 static inline int free_pages_check(struct page
*page
)
958 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
961 /* Something has gone sideways, find it */
962 free_pages_check_bad(page
);
966 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
971 * We rely page->lru.next never has bit 0 set, unless the page
972 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
974 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
976 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
980 switch (page
- head_page
) {
982 /* the first tail page: ->mapping is compound_mapcount() */
983 if (unlikely(compound_mapcount(page
))) {
984 bad_page(page
, "nonzero compound_mapcount", 0);
990 * the second tail page: ->mapping is
991 * page_deferred_list().next -- ignore value.
995 if (page
->mapping
!= TAIL_MAPPING
) {
996 bad_page(page
, "corrupted mapping in tail page", 0);
1001 if (unlikely(!PageTail(page
))) {
1002 bad_page(page
, "PageTail not set", 0);
1005 if (unlikely(compound_head(page
) != head_page
)) {
1006 bad_page(page
, "compound_head not consistent", 0);
1011 page
->mapping
= NULL
;
1012 clear_compound_head(page
);
1016 static __always_inline
bool free_pages_prepare(struct page
*page
,
1017 unsigned int order
, bool check_free
)
1021 VM_BUG_ON_PAGE(PageTail(page
), page
);
1023 trace_mm_page_free(page
, order
);
1026 * Check tail pages before head page information is cleared to
1027 * avoid checking PageCompound for order-0 pages.
1029 if (unlikely(order
)) {
1030 bool compound
= PageCompound(page
);
1033 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1036 ClearPageDoubleMap(page
);
1037 for (i
= 1; i
< (1 << order
); i
++) {
1039 bad
+= free_tail_pages_check(page
, page
+ i
);
1040 if (unlikely(free_pages_check(page
+ i
))) {
1044 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1047 if (PageMappingFlags(page
))
1048 page
->mapping
= NULL
;
1049 if (memcg_kmem_enabled() && PageKmemcg(page
))
1050 memcg_kmem_uncharge(page
, order
);
1052 bad
+= free_pages_check(page
);
1056 page_cpupid_reset_last(page
);
1057 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1058 reset_page_owner(page
, order
);
1060 if (!PageHighMem(page
)) {
1061 debug_check_no_locks_freed(page_address(page
),
1062 PAGE_SIZE
<< order
);
1063 debug_check_no_obj_freed(page_address(page
),
1064 PAGE_SIZE
<< order
);
1066 arch_free_page(page
, order
);
1067 kernel_poison_pages(page
, 1 << order
, 0);
1068 kernel_map_pages(page
, 1 << order
, 0);
1069 kasan_free_pages(page
, order
);
1074 #ifdef CONFIG_DEBUG_VM
1075 static inline bool free_pcp_prepare(struct page
*page
)
1077 return free_pages_prepare(page
, 0, true);
1080 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1085 static bool free_pcp_prepare(struct page
*page
)
1087 return free_pages_prepare(page
, 0, false);
1090 static bool bulkfree_pcp_prepare(struct page
*page
)
1092 return free_pages_check(page
);
1094 #endif /* CONFIG_DEBUG_VM */
1097 * Frees a number of pages from the PCP lists
1098 * Assumes all pages on list are in same zone, and of same order.
1099 * count is the number of pages to free.
1101 * If the zone was previously in an "all pages pinned" state then look to
1102 * see if this freeing clears that state.
1104 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1105 * pinned" detection logic.
1107 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1108 struct per_cpu_pages
*pcp
)
1110 int migratetype
= 0;
1112 bool isolated_pageblocks
;
1114 spin_lock(&zone
->lock
);
1115 isolated_pageblocks
= has_isolate_pageblock(zone
);
1119 struct list_head
*list
;
1122 * Remove pages from lists in a round-robin fashion. A
1123 * batch_free count is maintained that is incremented when an
1124 * empty list is encountered. This is so more pages are freed
1125 * off fuller lists instead of spinning excessively around empty
1130 if (++migratetype
== MIGRATE_PCPTYPES
)
1132 list
= &pcp
->lists
[migratetype
];
1133 } while (list_empty(list
));
1135 /* This is the only non-empty list. Free them all. */
1136 if (batch_free
== MIGRATE_PCPTYPES
)
1140 int mt
; /* migratetype of the to-be-freed page */
1142 page
= list_last_entry(list
, struct page
, lru
);
1143 /* must delete as __free_one_page list manipulates */
1144 list_del(&page
->lru
);
1146 mt
= get_pcppage_migratetype(page
);
1147 /* MIGRATE_ISOLATE page should not go to pcplists */
1148 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1149 /* Pageblock could have been isolated meanwhile */
1150 if (unlikely(isolated_pageblocks
))
1151 mt
= get_pageblock_migratetype(page
);
1153 if (bulkfree_pcp_prepare(page
))
1156 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1157 trace_mm_page_pcpu_drain(page
, 0, mt
);
1158 } while (--count
&& --batch_free
&& !list_empty(list
));
1160 spin_unlock(&zone
->lock
);
1163 static void free_one_page(struct zone
*zone
,
1164 struct page
*page
, unsigned long pfn
,
1168 spin_lock(&zone
->lock
);
1169 if (unlikely(has_isolate_pageblock(zone
) ||
1170 is_migrate_isolate(migratetype
))) {
1171 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1173 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1174 spin_unlock(&zone
->lock
);
1177 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1178 unsigned long zone
, int nid
)
1180 set_page_links(page
, zone
, nid
, pfn
);
1181 init_page_count(page
);
1182 page_mapcount_reset(page
);
1183 page_cpupid_reset_last(page
);
1185 INIT_LIST_HEAD(&page
->lru
);
1186 #ifdef WANT_PAGE_VIRTUAL
1187 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1188 if (!is_highmem_idx(zone
))
1189 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1193 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1196 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1199 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1200 static void __meminit
init_reserved_page(unsigned long pfn
)
1205 if (!early_page_uninitialised(pfn
))
1208 nid
= early_pfn_to_nid(pfn
);
1209 pgdat
= NODE_DATA(nid
);
1211 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1212 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1214 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1217 __init_single_pfn(pfn
, zid
, nid
);
1220 static inline void init_reserved_page(unsigned long pfn
)
1223 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1226 * Initialised pages do not have PageReserved set. This function is
1227 * called for each range allocated by the bootmem allocator and
1228 * marks the pages PageReserved. The remaining valid pages are later
1229 * sent to the buddy page allocator.
1231 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1233 unsigned long start_pfn
= PFN_DOWN(start
);
1234 unsigned long end_pfn
= PFN_UP(end
);
1236 for (; start_pfn
< end_pfn
; start_pfn
++) {
1237 if (pfn_valid(start_pfn
)) {
1238 struct page
*page
= pfn_to_page(start_pfn
);
1240 init_reserved_page(start_pfn
);
1242 /* Avoid false-positive PageTail() */
1243 INIT_LIST_HEAD(&page
->lru
);
1245 SetPageReserved(page
);
1250 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1252 unsigned long flags
;
1254 unsigned long pfn
= page_to_pfn(page
);
1256 if (!free_pages_prepare(page
, order
, true))
1259 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1260 local_irq_save(flags
);
1261 __count_vm_events(PGFREE
, 1 << order
);
1262 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1263 local_irq_restore(flags
);
1266 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1268 unsigned int nr_pages
= 1 << order
;
1269 struct page
*p
= page
;
1273 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1275 __ClearPageReserved(p
);
1276 set_page_count(p
, 0);
1278 __ClearPageReserved(p
);
1279 set_page_count(p
, 0);
1281 page_zone(page
)->managed_pages
+= nr_pages
;
1282 set_page_refcounted(page
);
1283 __free_pages(page
, order
);
1286 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1287 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1289 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1291 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1293 static DEFINE_SPINLOCK(early_pfn_lock
);
1296 spin_lock(&early_pfn_lock
);
1297 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1299 nid
= first_online_node
;
1300 spin_unlock(&early_pfn_lock
);
1306 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1307 static inline bool __meminit __maybe_unused
1308 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1309 struct mminit_pfnnid_cache
*state
)
1313 nid
= __early_pfn_to_nid(pfn
, state
);
1314 if (nid
>= 0 && nid
!= node
)
1319 /* Only safe to use early in boot when initialisation is single-threaded */
1320 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1322 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1327 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1331 static inline bool __meminit __maybe_unused
1332 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1333 struct mminit_pfnnid_cache
*state
)
1340 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1343 if (early_page_uninitialised(pfn
))
1345 return __free_pages_boot_core(page
, order
);
1349 * Check that the whole (or subset of) a pageblock given by the interval of
1350 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1351 * with the migration of free compaction scanner. The scanners then need to
1352 * use only pfn_valid_within() check for arches that allow holes within
1355 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1357 * It's possible on some configurations to have a setup like node0 node1 node0
1358 * i.e. it's possible that all pages within a zones range of pages do not
1359 * belong to a single zone. We assume that a border between node0 and node1
1360 * can occur within a single pageblock, but not a node0 node1 node0
1361 * interleaving within a single pageblock. It is therefore sufficient to check
1362 * the first and last page of a pageblock and avoid checking each individual
1363 * page in a pageblock.
1365 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1366 unsigned long end_pfn
, struct zone
*zone
)
1368 struct page
*start_page
;
1369 struct page
*end_page
;
1371 /* end_pfn is one past the range we are checking */
1374 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1377 start_page
= pfn_to_online_page(start_pfn
);
1381 if (page_zone(start_page
) != zone
)
1384 end_page
= pfn_to_page(end_pfn
);
1386 /* This gives a shorter code than deriving page_zone(end_page) */
1387 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1393 void set_zone_contiguous(struct zone
*zone
)
1395 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1396 unsigned long block_end_pfn
;
1398 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1399 for (; block_start_pfn
< zone_end_pfn(zone
);
1400 block_start_pfn
= block_end_pfn
,
1401 block_end_pfn
+= pageblock_nr_pages
) {
1403 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1405 if (!__pageblock_pfn_to_page(block_start_pfn
,
1406 block_end_pfn
, zone
))
1410 /* We confirm that there is no hole */
1411 zone
->contiguous
= true;
1414 void clear_zone_contiguous(struct zone
*zone
)
1416 zone
->contiguous
= false;
1419 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1420 static void __init
deferred_free_range(struct page
*page
,
1421 unsigned long pfn
, int nr_pages
)
1428 /* Free a large naturally-aligned chunk if possible */
1429 if (nr_pages
== pageblock_nr_pages
&&
1430 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1431 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1432 __free_pages_boot_core(page
, pageblock_order
);
1436 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1437 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1438 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1439 __free_pages_boot_core(page
, 0);
1443 /* Completion tracking for deferred_init_memmap() threads */
1444 static atomic_t pgdat_init_n_undone __initdata
;
1445 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1447 static inline void __init
pgdat_init_report_one_done(void)
1449 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1450 complete(&pgdat_init_all_done_comp
);
1453 /* Initialise remaining memory on a node */
1454 static int __init
deferred_init_memmap(void *data
)
1456 pg_data_t
*pgdat
= data
;
1457 int nid
= pgdat
->node_id
;
1458 struct mminit_pfnnid_cache nid_init_state
= { };
1459 unsigned long start
= jiffies
;
1460 unsigned long nr_pages
= 0;
1461 unsigned long walk_start
, walk_end
;
1464 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1465 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1467 if (first_init_pfn
== ULONG_MAX
) {
1468 pgdat_init_report_one_done();
1472 /* Bind memory initialisation thread to a local node if possible */
1473 if (!cpumask_empty(cpumask
))
1474 set_cpus_allowed_ptr(current
, cpumask
);
1476 /* Sanity check boundaries */
1477 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1478 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1479 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1481 /* Only the highest zone is deferred so find it */
1482 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1483 zone
= pgdat
->node_zones
+ zid
;
1484 if (first_init_pfn
< zone_end_pfn(zone
))
1488 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1489 unsigned long pfn
, end_pfn
;
1490 struct page
*page
= NULL
;
1491 struct page
*free_base_page
= NULL
;
1492 unsigned long free_base_pfn
= 0;
1495 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1496 pfn
= first_init_pfn
;
1497 if (pfn
< walk_start
)
1499 if (pfn
< zone
->zone_start_pfn
)
1500 pfn
= zone
->zone_start_pfn
;
1502 for (; pfn
< end_pfn
; pfn
++) {
1503 if (!pfn_valid_within(pfn
))
1507 * Ensure pfn_valid is checked every
1508 * pageblock_nr_pages for memory holes
1510 if ((pfn
& (pageblock_nr_pages
- 1)) == 0) {
1511 if (!pfn_valid(pfn
)) {
1517 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1522 /* Minimise pfn page lookups and scheduler checks */
1523 if (page
&& (pfn
& (pageblock_nr_pages
- 1)) != 0) {
1526 nr_pages
+= nr_to_free
;
1527 deferred_free_range(free_base_page
,
1528 free_base_pfn
, nr_to_free
);
1529 free_base_page
= NULL
;
1530 free_base_pfn
= nr_to_free
= 0;
1532 page
= pfn_to_page(pfn
);
1537 VM_BUG_ON(page_zone(page
) != zone
);
1541 __init_single_page(page
, pfn
, zid
, nid
);
1542 if (!free_base_page
) {
1543 free_base_page
= page
;
1544 free_base_pfn
= pfn
;
1549 /* Where possible, batch up pages for a single free */
1552 /* Free the current block of pages to allocator */
1553 nr_pages
+= nr_to_free
;
1554 deferred_free_range(free_base_page
, free_base_pfn
,
1556 free_base_page
= NULL
;
1557 free_base_pfn
= nr_to_free
= 0;
1559 /* Free the last block of pages to allocator */
1560 nr_pages
+= nr_to_free
;
1561 deferred_free_range(free_base_page
, free_base_pfn
, nr_to_free
);
1563 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1566 /* Sanity check that the next zone really is unpopulated */
1567 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1569 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1570 jiffies_to_msecs(jiffies
- start
));
1572 pgdat_init_report_one_done();
1575 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1577 void __init
page_alloc_init_late(void)
1581 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1584 /* There will be num_node_state(N_MEMORY) threads */
1585 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1586 for_each_node_state(nid
, N_MEMORY
) {
1587 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1590 /* Block until all are initialised */
1591 wait_for_completion(&pgdat_init_all_done_comp
);
1593 /* Reinit limits that are based on free pages after the kernel is up */
1594 files_maxfiles_init();
1596 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
1597 /* Discard memblock private memory */
1601 for_each_populated_zone(zone
)
1602 set_zone_contiguous(zone
);
1606 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1607 void __init
init_cma_reserved_pageblock(struct page
*page
)
1609 unsigned i
= pageblock_nr_pages
;
1610 struct page
*p
= page
;
1613 __ClearPageReserved(p
);
1614 set_page_count(p
, 0);
1617 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1619 if (pageblock_order
>= MAX_ORDER
) {
1620 i
= pageblock_nr_pages
;
1623 set_page_refcounted(p
);
1624 __free_pages(p
, MAX_ORDER
- 1);
1625 p
+= MAX_ORDER_NR_PAGES
;
1626 } while (i
-= MAX_ORDER_NR_PAGES
);
1628 set_page_refcounted(page
);
1629 __free_pages(page
, pageblock_order
);
1632 adjust_managed_page_count(page
, pageblock_nr_pages
);
1637 * The order of subdivision here is critical for the IO subsystem.
1638 * Please do not alter this order without good reasons and regression
1639 * testing. Specifically, as large blocks of memory are subdivided,
1640 * the order in which smaller blocks are delivered depends on the order
1641 * they're subdivided in this function. This is the primary factor
1642 * influencing the order in which pages are delivered to the IO
1643 * subsystem according to empirical testing, and this is also justified
1644 * by considering the behavior of a buddy system containing a single
1645 * large block of memory acted on by a series of small allocations.
1646 * This behavior is a critical factor in sglist merging's success.
1650 static inline void expand(struct zone
*zone
, struct page
*page
,
1651 int low
, int high
, struct free_area
*area
,
1654 unsigned long size
= 1 << high
;
1656 while (high
> low
) {
1660 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1663 * Mark as guard pages (or page), that will allow to
1664 * merge back to allocator when buddy will be freed.
1665 * Corresponding page table entries will not be touched,
1666 * pages will stay not present in virtual address space
1668 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1671 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1673 set_page_order(&page
[size
], high
);
1677 static void check_new_page_bad(struct page
*page
)
1679 const char *bad_reason
= NULL
;
1680 unsigned long bad_flags
= 0;
1682 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1683 bad_reason
= "nonzero mapcount";
1684 if (unlikely(page
->mapping
!= NULL
))
1685 bad_reason
= "non-NULL mapping";
1686 if (unlikely(page_ref_count(page
) != 0))
1687 bad_reason
= "nonzero _count";
1688 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1689 bad_reason
= "HWPoisoned (hardware-corrupted)";
1690 bad_flags
= __PG_HWPOISON
;
1691 /* Don't complain about hwpoisoned pages */
1692 page_mapcount_reset(page
); /* remove PageBuddy */
1695 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1696 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1697 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1700 if (unlikely(page
->mem_cgroup
))
1701 bad_reason
= "page still charged to cgroup";
1703 bad_page(page
, bad_reason
, bad_flags
);
1707 * This page is about to be returned from the page allocator
1709 static inline int check_new_page(struct page
*page
)
1711 if (likely(page_expected_state(page
,
1712 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1715 check_new_page_bad(page
);
1719 static inline bool free_pages_prezeroed(void)
1721 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1722 page_poisoning_enabled();
1725 #ifdef CONFIG_DEBUG_VM
1726 static bool check_pcp_refill(struct page
*page
)
1731 static bool check_new_pcp(struct page
*page
)
1733 return check_new_page(page
);
1736 static bool check_pcp_refill(struct page
*page
)
1738 return check_new_page(page
);
1740 static bool check_new_pcp(struct page
*page
)
1744 #endif /* CONFIG_DEBUG_VM */
1746 static bool check_new_pages(struct page
*page
, unsigned int order
)
1749 for (i
= 0; i
< (1 << order
); i
++) {
1750 struct page
*p
= page
+ i
;
1752 if (unlikely(check_new_page(p
)))
1759 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1762 set_page_private(page
, 0);
1763 set_page_refcounted(page
);
1765 arch_alloc_page(page
, order
);
1766 kernel_map_pages(page
, 1 << order
, 1);
1767 kernel_poison_pages(page
, 1 << order
, 1);
1768 kasan_alloc_pages(page
, order
);
1769 set_page_owner(page
, order
, gfp_flags
);
1772 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1773 unsigned int alloc_flags
)
1777 post_alloc_hook(page
, order
, gfp_flags
);
1779 if (!free_pages_prezeroed() && (gfp_flags
& __GFP_ZERO
))
1780 for (i
= 0; i
< (1 << order
); i
++)
1781 clear_highpage(page
+ i
);
1783 if (order
&& (gfp_flags
& __GFP_COMP
))
1784 prep_compound_page(page
, order
);
1787 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1788 * allocate the page. The expectation is that the caller is taking
1789 * steps that will free more memory. The caller should avoid the page
1790 * being used for !PFMEMALLOC purposes.
1792 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1793 set_page_pfmemalloc(page
);
1795 clear_page_pfmemalloc(page
);
1799 * Go through the free lists for the given migratetype and remove
1800 * the smallest available page from the freelists
1803 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1806 unsigned int current_order
;
1807 struct free_area
*area
;
1810 /* Find a page of the appropriate size in the preferred list */
1811 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1812 area
= &(zone
->free_area
[current_order
]);
1813 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1817 list_del(&page
->lru
);
1818 rmv_page_order(page
);
1820 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1821 set_pcppage_migratetype(page
, migratetype
);
1830 * This array describes the order lists are fallen back to when
1831 * the free lists for the desirable migrate type are depleted
1833 static int fallbacks
[MIGRATE_TYPES
][4] = {
1834 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1835 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1836 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1838 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1840 #ifdef CONFIG_MEMORY_ISOLATION
1841 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1846 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1849 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1852 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1853 unsigned int order
) { return NULL
; }
1857 * Move the free pages in a range to the free lists of the requested type.
1858 * Note that start_page and end_pages are not aligned on a pageblock
1859 * boundary. If alignment is required, use move_freepages_block()
1861 static int move_freepages(struct zone
*zone
,
1862 struct page
*start_page
, struct page
*end_page
,
1863 int migratetype
, int *num_movable
)
1867 int pages_moved
= 0;
1869 #ifndef CONFIG_HOLES_IN_ZONE
1871 * page_zone is not safe to call in this context when
1872 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1873 * anyway as we check zone boundaries in move_freepages_block().
1874 * Remove at a later date when no bug reports exist related to
1875 * grouping pages by mobility
1877 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1883 for (page
= start_page
; page
<= end_page
;) {
1884 if (!pfn_valid_within(page_to_pfn(page
))) {
1889 /* Make sure we are not inadvertently changing nodes */
1890 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1892 if (!PageBuddy(page
)) {
1894 * We assume that pages that could be isolated for
1895 * migration are movable. But we don't actually try
1896 * isolating, as that would be expensive.
1899 (PageLRU(page
) || __PageMovable(page
)))
1906 order
= page_order(page
);
1907 list_move(&page
->lru
,
1908 &zone
->free_area
[order
].free_list
[migratetype
]);
1910 pages_moved
+= 1 << order
;
1916 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1917 int migratetype
, int *num_movable
)
1919 unsigned long start_pfn
, end_pfn
;
1920 struct page
*start_page
, *end_page
;
1922 start_pfn
= page_to_pfn(page
);
1923 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1924 start_page
= pfn_to_page(start_pfn
);
1925 end_page
= start_page
+ pageblock_nr_pages
- 1;
1926 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1928 /* Do not cross zone boundaries */
1929 if (!zone_spans_pfn(zone
, start_pfn
))
1931 if (!zone_spans_pfn(zone
, end_pfn
))
1934 return move_freepages(zone
, start_page
, end_page
, migratetype
,
1938 static void change_pageblock_range(struct page
*pageblock_page
,
1939 int start_order
, int migratetype
)
1941 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1943 while (nr_pageblocks
--) {
1944 set_pageblock_migratetype(pageblock_page
, migratetype
);
1945 pageblock_page
+= pageblock_nr_pages
;
1950 * When we are falling back to another migratetype during allocation, try to
1951 * steal extra free pages from the same pageblocks to satisfy further
1952 * allocations, instead of polluting multiple pageblocks.
1954 * If we are stealing a relatively large buddy page, it is likely there will
1955 * be more free pages in the pageblock, so try to steal them all. For
1956 * reclaimable and unmovable allocations, we steal regardless of page size,
1957 * as fragmentation caused by those allocations polluting movable pageblocks
1958 * is worse than movable allocations stealing from unmovable and reclaimable
1961 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1964 * Leaving this order check is intended, although there is
1965 * relaxed order check in next check. The reason is that
1966 * we can actually steal whole pageblock if this condition met,
1967 * but, below check doesn't guarantee it and that is just heuristic
1968 * so could be changed anytime.
1970 if (order
>= pageblock_order
)
1973 if (order
>= pageblock_order
/ 2 ||
1974 start_mt
== MIGRATE_RECLAIMABLE
||
1975 start_mt
== MIGRATE_UNMOVABLE
||
1976 page_group_by_mobility_disabled
)
1983 * This function implements actual steal behaviour. If order is large enough,
1984 * we can steal whole pageblock. If not, we first move freepages in this
1985 * pageblock to our migratetype and determine how many already-allocated pages
1986 * are there in the pageblock with a compatible migratetype. If at least half
1987 * of pages are free or compatible, we can change migratetype of the pageblock
1988 * itself, so pages freed in the future will be put on the correct free list.
1990 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1991 int start_type
, bool whole_block
)
1993 unsigned int current_order
= page_order(page
);
1994 struct free_area
*area
;
1995 int free_pages
, movable_pages
, alike_pages
;
1998 old_block_type
= get_pageblock_migratetype(page
);
2001 * This can happen due to races and we want to prevent broken
2002 * highatomic accounting.
2004 if (is_migrate_highatomic(old_block_type
))
2007 /* Take ownership for orders >= pageblock_order */
2008 if (current_order
>= pageblock_order
) {
2009 change_pageblock_range(page
, current_order
, start_type
);
2013 /* We are not allowed to try stealing from the whole block */
2017 free_pages
= move_freepages_block(zone
, page
, start_type
,
2020 * Determine how many pages are compatible with our allocation.
2021 * For movable allocation, it's the number of movable pages which
2022 * we just obtained. For other types it's a bit more tricky.
2024 if (start_type
== MIGRATE_MOVABLE
) {
2025 alike_pages
= movable_pages
;
2028 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2029 * to MOVABLE pageblock, consider all non-movable pages as
2030 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2031 * vice versa, be conservative since we can't distinguish the
2032 * exact migratetype of non-movable pages.
2034 if (old_block_type
== MIGRATE_MOVABLE
)
2035 alike_pages
= pageblock_nr_pages
2036 - (free_pages
+ movable_pages
);
2041 /* moving whole block can fail due to zone boundary conditions */
2046 * If a sufficient number of pages in the block are either free or of
2047 * comparable migratability as our allocation, claim the whole block.
2049 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2050 page_group_by_mobility_disabled
)
2051 set_pageblock_migratetype(page
, start_type
);
2056 area
= &zone
->free_area
[current_order
];
2057 list_move(&page
->lru
, &area
->free_list
[start_type
]);
2061 * Check whether there is a suitable fallback freepage with requested order.
2062 * If only_stealable is true, this function returns fallback_mt only if
2063 * we can steal other freepages all together. This would help to reduce
2064 * fragmentation due to mixed migratetype pages in one pageblock.
2066 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2067 int migratetype
, bool only_stealable
, bool *can_steal
)
2072 if (area
->nr_free
== 0)
2077 fallback_mt
= fallbacks
[migratetype
][i
];
2078 if (fallback_mt
== MIGRATE_TYPES
)
2081 if (list_empty(&area
->free_list
[fallback_mt
]))
2084 if (can_steal_fallback(order
, migratetype
))
2087 if (!only_stealable
)
2098 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2099 * there are no empty page blocks that contain a page with a suitable order
2101 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2102 unsigned int alloc_order
)
2105 unsigned long max_managed
, flags
;
2108 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2109 * Check is race-prone but harmless.
2111 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2112 if (zone
->nr_reserved_highatomic
>= max_managed
)
2115 spin_lock_irqsave(&zone
->lock
, flags
);
2117 /* Recheck the nr_reserved_highatomic limit under the lock */
2118 if (zone
->nr_reserved_highatomic
>= max_managed
)
2122 mt
= get_pageblock_migratetype(page
);
2123 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2124 && !is_migrate_cma(mt
)) {
2125 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2126 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2127 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2131 spin_unlock_irqrestore(&zone
->lock
, flags
);
2135 * Used when an allocation is about to fail under memory pressure. This
2136 * potentially hurts the reliability of high-order allocations when under
2137 * intense memory pressure but failed atomic allocations should be easier
2138 * to recover from than an OOM.
2140 * If @force is true, try to unreserve a pageblock even though highatomic
2141 * pageblock is exhausted.
2143 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2146 struct zonelist
*zonelist
= ac
->zonelist
;
2147 unsigned long flags
;
2154 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2157 * Preserve at least one pageblock unless memory pressure
2160 if (!force
&& zone
->nr_reserved_highatomic
<=
2164 spin_lock_irqsave(&zone
->lock
, flags
);
2165 for (order
= 0; order
< MAX_ORDER
; order
++) {
2166 struct free_area
*area
= &(zone
->free_area
[order
]);
2168 page
= list_first_entry_or_null(
2169 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2175 * In page freeing path, migratetype change is racy so
2176 * we can counter several free pages in a pageblock
2177 * in this loop althoug we changed the pageblock type
2178 * from highatomic to ac->migratetype. So we should
2179 * adjust the count once.
2181 if (is_migrate_highatomic_page(page
)) {
2183 * It should never happen but changes to
2184 * locking could inadvertently allow a per-cpu
2185 * drain to add pages to MIGRATE_HIGHATOMIC
2186 * while unreserving so be safe and watch for
2189 zone
->nr_reserved_highatomic
-= min(
2191 zone
->nr_reserved_highatomic
);
2195 * Convert to ac->migratetype and avoid the normal
2196 * pageblock stealing heuristics. Minimally, the caller
2197 * is doing the work and needs the pages. More
2198 * importantly, if the block was always converted to
2199 * MIGRATE_UNMOVABLE or another type then the number
2200 * of pageblocks that cannot be completely freed
2203 set_pageblock_migratetype(page
, ac
->migratetype
);
2204 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2207 spin_unlock_irqrestore(&zone
->lock
, flags
);
2211 spin_unlock_irqrestore(&zone
->lock
, flags
);
2218 * Try finding a free buddy page on the fallback list and put it on the free
2219 * list of requested migratetype, possibly along with other pages from the same
2220 * block, depending on fragmentation avoidance heuristics. Returns true if
2221 * fallback was found so that __rmqueue_smallest() can grab it.
2223 * The use of signed ints for order and current_order is a deliberate
2224 * deviation from the rest of this file, to make the for loop
2225 * condition simpler.
2228 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
2230 struct free_area
*area
;
2237 * Find the largest available free page in the other list. This roughly
2238 * approximates finding the pageblock with the most free pages, which
2239 * would be too costly to do exactly.
2241 for (current_order
= MAX_ORDER
- 1; current_order
>= order
;
2243 area
= &(zone
->free_area
[current_order
]);
2244 fallback_mt
= find_suitable_fallback(area
, current_order
,
2245 start_migratetype
, false, &can_steal
);
2246 if (fallback_mt
== -1)
2250 * We cannot steal all free pages from the pageblock and the
2251 * requested migratetype is movable. In that case it's better to
2252 * steal and split the smallest available page instead of the
2253 * largest available page, because even if the next movable
2254 * allocation falls back into a different pageblock than this
2255 * one, it won't cause permanent fragmentation.
2257 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2258 && current_order
> order
)
2267 for (current_order
= order
; current_order
< MAX_ORDER
;
2269 area
= &(zone
->free_area
[current_order
]);
2270 fallback_mt
= find_suitable_fallback(area
, current_order
,
2271 start_migratetype
, false, &can_steal
);
2272 if (fallback_mt
!= -1)
2277 * This should not happen - we already found a suitable fallback
2278 * when looking for the largest page.
2280 VM_BUG_ON(current_order
== MAX_ORDER
);
2283 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2286 steal_suitable_fallback(zone
, page
, start_migratetype
, can_steal
);
2288 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2289 start_migratetype
, fallback_mt
);
2296 * Do the hard work of removing an element from the buddy allocator.
2297 * Call me with the zone->lock already held.
2299 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2305 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2306 if (unlikely(!page
)) {
2307 if (migratetype
== MIGRATE_MOVABLE
)
2308 page
= __rmqueue_cma_fallback(zone
, order
);
2310 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
))
2314 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2319 * Obtain a specified number of elements from the buddy allocator, all under
2320 * a single hold of the lock, for efficiency. Add them to the supplied list.
2321 * Returns the number of new pages which were placed at *list.
2323 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2324 unsigned long count
, struct list_head
*list
,
2325 int migratetype
, bool cold
)
2329 spin_lock(&zone
->lock
);
2330 for (i
= 0; i
< count
; ++i
) {
2331 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2332 if (unlikely(page
== NULL
))
2335 if (unlikely(check_pcp_refill(page
)))
2339 * Split buddy pages returned by expand() are received here
2340 * in physical page order. The page is added to the callers and
2341 * list and the list head then moves forward. From the callers
2342 * perspective, the linked list is ordered by page number in
2343 * some conditions. This is useful for IO devices that can
2344 * merge IO requests if the physical pages are ordered
2348 list_add(&page
->lru
, list
);
2350 list_add_tail(&page
->lru
, list
);
2353 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2354 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2359 * i pages were removed from the buddy list even if some leak due
2360 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2361 * on i. Do not confuse with 'alloced' which is the number of
2362 * pages added to the pcp list.
2364 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2365 spin_unlock(&zone
->lock
);
2371 * Called from the vmstat counter updater to drain pagesets of this
2372 * currently executing processor on remote nodes after they have
2375 * Note that this function must be called with the thread pinned to
2376 * a single processor.
2378 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2380 unsigned long flags
;
2381 int to_drain
, batch
;
2383 local_irq_save(flags
);
2384 batch
= READ_ONCE(pcp
->batch
);
2385 to_drain
= min(pcp
->count
, batch
);
2387 free_pcppages_bulk(zone
, to_drain
, pcp
);
2388 pcp
->count
-= to_drain
;
2390 local_irq_restore(flags
);
2395 * Drain pcplists of the indicated processor and zone.
2397 * The processor must either be the current processor and the
2398 * thread pinned to the current processor or a processor that
2401 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2403 unsigned long flags
;
2404 struct per_cpu_pageset
*pset
;
2405 struct per_cpu_pages
*pcp
;
2407 local_irq_save(flags
);
2408 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2412 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2415 local_irq_restore(flags
);
2419 * Drain pcplists of all zones on the indicated processor.
2421 * The processor must either be the current processor and the
2422 * thread pinned to the current processor or a processor that
2425 static void drain_pages(unsigned int cpu
)
2429 for_each_populated_zone(zone
) {
2430 drain_pages_zone(cpu
, zone
);
2435 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2437 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2438 * the single zone's pages.
2440 void drain_local_pages(struct zone
*zone
)
2442 int cpu
= smp_processor_id();
2445 drain_pages_zone(cpu
, zone
);
2450 static void drain_local_pages_wq(struct work_struct
*work
)
2453 * drain_all_pages doesn't use proper cpu hotplug protection so
2454 * we can race with cpu offline when the WQ can move this from
2455 * a cpu pinned worker to an unbound one. We can operate on a different
2456 * cpu which is allright but we also have to make sure to not move to
2460 drain_local_pages(NULL
);
2465 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2467 * When zone parameter is non-NULL, spill just the single zone's pages.
2469 * Note that this can be extremely slow as the draining happens in a workqueue.
2471 void drain_all_pages(struct zone
*zone
)
2476 * Allocate in the BSS so we wont require allocation in
2477 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2479 static cpumask_t cpus_with_pcps
;
2482 * Make sure nobody triggers this path before mm_percpu_wq is fully
2485 if (WARN_ON_ONCE(!mm_percpu_wq
))
2489 * Do not drain if one is already in progress unless it's specific to
2490 * a zone. Such callers are primarily CMA and memory hotplug and need
2491 * the drain to be complete when the call returns.
2493 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2496 mutex_lock(&pcpu_drain_mutex
);
2500 * We don't care about racing with CPU hotplug event
2501 * as offline notification will cause the notified
2502 * cpu to drain that CPU pcps and on_each_cpu_mask
2503 * disables preemption as part of its processing
2505 for_each_online_cpu(cpu
) {
2506 struct per_cpu_pageset
*pcp
;
2508 bool has_pcps
= false;
2511 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2515 for_each_populated_zone(z
) {
2516 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2517 if (pcp
->pcp
.count
) {
2525 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2527 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2530 for_each_cpu(cpu
, &cpus_with_pcps
) {
2531 struct work_struct
*work
= per_cpu_ptr(&pcpu_drain
, cpu
);
2532 INIT_WORK(work
, drain_local_pages_wq
);
2533 queue_work_on(cpu
, mm_percpu_wq
, work
);
2535 for_each_cpu(cpu
, &cpus_with_pcps
)
2536 flush_work(per_cpu_ptr(&pcpu_drain
, cpu
));
2538 mutex_unlock(&pcpu_drain_mutex
);
2541 #ifdef CONFIG_HIBERNATION
2544 * Touch the watchdog for every WD_PAGE_COUNT pages.
2546 #define WD_PAGE_COUNT (128*1024)
2548 void mark_free_pages(struct zone
*zone
)
2550 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
2551 unsigned long flags
;
2552 unsigned int order
, t
;
2555 if (zone_is_empty(zone
))
2558 spin_lock_irqsave(&zone
->lock
, flags
);
2560 max_zone_pfn
= zone_end_pfn(zone
);
2561 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2562 if (pfn_valid(pfn
)) {
2563 page
= pfn_to_page(pfn
);
2565 if (!--page_count
) {
2566 touch_nmi_watchdog();
2567 page_count
= WD_PAGE_COUNT
;
2570 if (page_zone(page
) != zone
)
2573 if (!swsusp_page_is_forbidden(page
))
2574 swsusp_unset_page_free(page
);
2577 for_each_migratetype_order(order
, t
) {
2578 list_for_each_entry(page
,
2579 &zone
->free_area
[order
].free_list
[t
], lru
) {
2582 pfn
= page_to_pfn(page
);
2583 for (i
= 0; i
< (1UL << order
); i
++) {
2584 if (!--page_count
) {
2585 touch_nmi_watchdog();
2586 page_count
= WD_PAGE_COUNT
;
2588 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2592 spin_unlock_irqrestore(&zone
->lock
, flags
);
2594 #endif /* CONFIG_PM */
2597 * Free a 0-order page
2598 * cold == true ? free a cold page : free a hot page
2600 void free_hot_cold_page(struct page
*page
, bool cold
)
2602 struct zone
*zone
= page_zone(page
);
2603 struct per_cpu_pages
*pcp
;
2604 unsigned long flags
;
2605 unsigned long pfn
= page_to_pfn(page
);
2608 if (!free_pcp_prepare(page
))
2611 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2612 set_pcppage_migratetype(page
, migratetype
);
2613 local_irq_save(flags
);
2614 __count_vm_event(PGFREE
);
2617 * We only track unmovable, reclaimable and movable on pcp lists.
2618 * Free ISOLATE pages back to the allocator because they are being
2619 * offlined but treat HIGHATOMIC as movable pages so we can get those
2620 * areas back if necessary. Otherwise, we may have to free
2621 * excessively into the page allocator
2623 if (migratetype
>= MIGRATE_PCPTYPES
) {
2624 if (unlikely(is_migrate_isolate(migratetype
))) {
2625 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2628 migratetype
= MIGRATE_MOVABLE
;
2631 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2633 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2635 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2637 if (pcp
->count
>= pcp
->high
) {
2638 unsigned long batch
= READ_ONCE(pcp
->batch
);
2639 free_pcppages_bulk(zone
, batch
, pcp
);
2640 pcp
->count
-= batch
;
2644 local_irq_restore(flags
);
2648 * Free a list of 0-order pages
2650 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2652 struct page
*page
, *next
;
2654 list_for_each_entry_safe(page
, next
, list
, lru
) {
2655 trace_mm_page_free_batched(page
, cold
);
2656 free_hot_cold_page(page
, cold
);
2661 * split_page takes a non-compound higher-order page, and splits it into
2662 * n (1<<order) sub-pages: page[0..n]
2663 * Each sub-page must be freed individually.
2665 * Note: this is probably too low level an operation for use in drivers.
2666 * Please consult with lkml before using this in your driver.
2668 void split_page(struct page
*page
, unsigned int order
)
2672 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2673 VM_BUG_ON_PAGE(!page_count(page
), page
);
2675 for (i
= 1; i
< (1 << order
); i
++)
2676 set_page_refcounted(page
+ i
);
2677 split_page_owner(page
, order
);
2679 EXPORT_SYMBOL_GPL(split_page
);
2681 int __isolate_free_page(struct page
*page
, unsigned int order
)
2683 unsigned long watermark
;
2687 BUG_ON(!PageBuddy(page
));
2689 zone
= page_zone(page
);
2690 mt
= get_pageblock_migratetype(page
);
2692 if (!is_migrate_isolate(mt
)) {
2694 * Obey watermarks as if the page was being allocated. We can
2695 * emulate a high-order watermark check with a raised order-0
2696 * watermark, because we already know our high-order page
2699 watermark
= min_wmark_pages(zone
) + (1UL << order
);
2700 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
2703 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2706 /* Remove page from free list */
2707 list_del(&page
->lru
);
2708 zone
->free_area
[order
].nr_free
--;
2709 rmv_page_order(page
);
2712 * Set the pageblock if the isolated page is at least half of a
2715 if (order
>= pageblock_order
- 1) {
2716 struct page
*endpage
= page
+ (1 << order
) - 1;
2717 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2718 int mt
= get_pageblock_migratetype(page
);
2719 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
2720 && !is_migrate_highatomic(mt
))
2721 set_pageblock_migratetype(page
,
2727 return 1UL << order
;
2731 * Update NUMA hit/miss statistics
2733 * Must be called with interrupts disabled.
2735 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
2738 enum numa_stat_item local_stat
= NUMA_LOCAL
;
2740 if (z
->node
!= numa_node_id())
2741 local_stat
= NUMA_OTHER
;
2743 if (z
->node
== preferred_zone
->node
)
2744 __inc_numa_state(z
, NUMA_HIT
);
2746 __inc_numa_state(z
, NUMA_MISS
);
2747 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
2749 __inc_numa_state(z
, local_stat
);
2753 /* Remove page from the per-cpu list, caller must protect the list */
2754 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
2755 bool cold
, struct per_cpu_pages
*pcp
,
2756 struct list_head
*list
)
2761 if (list_empty(list
)) {
2762 pcp
->count
+= rmqueue_bulk(zone
, 0,
2765 if (unlikely(list_empty(list
)))
2770 page
= list_last_entry(list
, struct page
, lru
);
2772 page
= list_first_entry(list
, struct page
, lru
);
2774 list_del(&page
->lru
);
2776 } while (check_new_pcp(page
));
2781 /* Lock and remove page from the per-cpu list */
2782 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
2783 struct zone
*zone
, unsigned int order
,
2784 gfp_t gfp_flags
, int migratetype
)
2786 struct per_cpu_pages
*pcp
;
2787 struct list_head
*list
;
2788 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2790 unsigned long flags
;
2792 local_irq_save(flags
);
2793 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2794 list
= &pcp
->lists
[migratetype
];
2795 page
= __rmqueue_pcplist(zone
, migratetype
, cold
, pcp
, list
);
2797 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2798 zone_statistics(preferred_zone
, zone
);
2800 local_irq_restore(flags
);
2805 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2808 struct page
*rmqueue(struct zone
*preferred_zone
,
2809 struct zone
*zone
, unsigned int order
,
2810 gfp_t gfp_flags
, unsigned int alloc_flags
,
2813 unsigned long flags
;
2816 if (likely(order
== 0)) {
2817 page
= rmqueue_pcplist(preferred_zone
, zone
, order
,
2818 gfp_flags
, migratetype
);
2823 * We most definitely don't want callers attempting to
2824 * allocate greater than order-1 page units with __GFP_NOFAIL.
2826 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2827 spin_lock_irqsave(&zone
->lock
, flags
);
2831 if (alloc_flags
& ALLOC_HARDER
) {
2832 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2834 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2837 page
= __rmqueue(zone
, order
, migratetype
);
2838 } while (page
&& check_new_pages(page
, order
));
2839 spin_unlock(&zone
->lock
);
2842 __mod_zone_freepage_state(zone
, -(1 << order
),
2843 get_pcppage_migratetype(page
));
2845 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2846 zone_statistics(preferred_zone
, zone
);
2847 local_irq_restore(flags
);
2850 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
2854 local_irq_restore(flags
);
2858 #ifdef CONFIG_FAIL_PAGE_ALLOC
2861 struct fault_attr attr
;
2863 bool ignore_gfp_highmem
;
2864 bool ignore_gfp_reclaim
;
2866 } fail_page_alloc
= {
2867 .attr
= FAULT_ATTR_INITIALIZER
,
2868 .ignore_gfp_reclaim
= true,
2869 .ignore_gfp_highmem
= true,
2873 static int __init
setup_fail_page_alloc(char *str
)
2875 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2877 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2879 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2881 if (order
< fail_page_alloc
.min_order
)
2883 if (gfp_mask
& __GFP_NOFAIL
)
2885 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2887 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2888 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2891 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2894 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2896 static int __init
fail_page_alloc_debugfs(void)
2898 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2901 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2902 &fail_page_alloc
.attr
);
2904 return PTR_ERR(dir
);
2906 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2907 &fail_page_alloc
.ignore_gfp_reclaim
))
2909 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2910 &fail_page_alloc
.ignore_gfp_highmem
))
2912 if (!debugfs_create_u32("min-order", mode
, dir
,
2913 &fail_page_alloc
.min_order
))
2918 debugfs_remove_recursive(dir
);
2923 late_initcall(fail_page_alloc_debugfs
);
2925 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2927 #else /* CONFIG_FAIL_PAGE_ALLOC */
2929 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2934 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2937 * Return true if free base pages are above 'mark'. For high-order checks it
2938 * will return true of the order-0 watermark is reached and there is at least
2939 * one free page of a suitable size. Checking now avoids taking the zone lock
2940 * to check in the allocation paths if no pages are free.
2942 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2943 int classzone_idx
, unsigned int alloc_flags
,
2948 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
2950 /* free_pages may go negative - that's OK */
2951 free_pages
-= (1 << order
) - 1;
2953 if (alloc_flags
& ALLOC_HIGH
)
2957 * If the caller does not have rights to ALLOC_HARDER then subtract
2958 * the high-atomic reserves. This will over-estimate the size of the
2959 * atomic reserve but it avoids a search.
2961 if (likely(!alloc_harder
)) {
2962 free_pages
-= z
->nr_reserved_highatomic
;
2965 * OOM victims can try even harder than normal ALLOC_HARDER
2966 * users on the grounds that it's definitely going to be in
2967 * the exit path shortly and free memory. Any allocation it
2968 * makes during the free path will be small and short-lived.
2970 if (alloc_flags
& ALLOC_OOM
)
2978 /* If allocation can't use CMA areas don't use free CMA pages */
2979 if (!(alloc_flags
& ALLOC_CMA
))
2980 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2984 * Check watermarks for an order-0 allocation request. If these
2985 * are not met, then a high-order request also cannot go ahead
2986 * even if a suitable page happened to be free.
2988 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2991 /* If this is an order-0 request then the watermark is fine */
2995 /* For a high-order request, check at least one suitable page is free */
2996 for (o
= order
; o
< MAX_ORDER
; o
++) {
2997 struct free_area
*area
= &z
->free_area
[o
];
3003 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3004 if (!list_empty(&area
->free_list
[mt
]))
3009 if ((alloc_flags
& ALLOC_CMA
) &&
3010 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
3015 !list_empty(&area
->free_list
[MIGRATE_HIGHATOMIC
]))
3021 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3022 int classzone_idx
, unsigned int alloc_flags
)
3024 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3025 zone_page_state(z
, NR_FREE_PAGES
));
3028 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3029 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
3031 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3035 /* If allocation can't use CMA areas don't use free CMA pages */
3036 if (!(alloc_flags
& ALLOC_CMA
))
3037 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3041 * Fast check for order-0 only. If this fails then the reserves
3042 * need to be calculated. There is a corner case where the check
3043 * passes but only the high-order atomic reserve are free. If
3044 * the caller is !atomic then it'll uselessly search the free
3045 * list. That corner case is then slower but it is harmless.
3047 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
3050 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3054 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3055 unsigned long mark
, int classzone_idx
)
3057 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3059 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3060 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3062 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
3067 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3069 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3072 #else /* CONFIG_NUMA */
3073 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3077 #endif /* CONFIG_NUMA */
3080 * get_page_from_freelist goes through the zonelist trying to allocate
3083 static struct page
*
3084 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3085 const struct alloc_context
*ac
)
3087 struct zoneref
*z
= ac
->preferred_zoneref
;
3089 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3092 * Scan zonelist, looking for a zone with enough free.
3093 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3095 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3100 if (cpusets_enabled() &&
3101 (alloc_flags
& ALLOC_CPUSET
) &&
3102 !__cpuset_zone_allowed(zone
, gfp_mask
))
3105 * When allocating a page cache page for writing, we
3106 * want to get it from a node that is within its dirty
3107 * limit, such that no single node holds more than its
3108 * proportional share of globally allowed dirty pages.
3109 * The dirty limits take into account the node's
3110 * lowmem reserves and high watermark so that kswapd
3111 * should be able to balance it without having to
3112 * write pages from its LRU list.
3114 * XXX: For now, allow allocations to potentially
3115 * exceed the per-node dirty limit in the slowpath
3116 * (spread_dirty_pages unset) before going into reclaim,
3117 * which is important when on a NUMA setup the allowed
3118 * nodes are together not big enough to reach the
3119 * global limit. The proper fix for these situations
3120 * will require awareness of nodes in the
3121 * dirty-throttling and the flusher threads.
3123 if (ac
->spread_dirty_pages
) {
3124 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3127 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3128 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3133 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
3134 if (!zone_watermark_fast(zone
, order
, mark
,
3135 ac_classzone_idx(ac
), alloc_flags
)) {
3138 /* Checked here to keep the fast path fast */
3139 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3140 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3143 if (node_reclaim_mode
== 0 ||
3144 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3147 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3149 case NODE_RECLAIM_NOSCAN
:
3152 case NODE_RECLAIM_FULL
:
3153 /* scanned but unreclaimable */
3156 /* did we reclaim enough */
3157 if (zone_watermark_ok(zone
, order
, mark
,
3158 ac_classzone_idx(ac
), alloc_flags
))
3166 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3167 gfp_mask
, alloc_flags
, ac
->migratetype
);
3169 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3172 * If this is a high-order atomic allocation then check
3173 * if the pageblock should be reserved for the future
3175 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3176 reserve_highatomic_pageblock(page
, zone
, order
);
3186 * Large machines with many possible nodes should not always dump per-node
3187 * meminfo in irq context.
3189 static inline bool should_suppress_show_mem(void)
3194 ret
= in_interrupt();
3199 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3201 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3202 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3204 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs
))
3208 * This documents exceptions given to allocations in certain
3209 * contexts that are allowed to allocate outside current's set
3212 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3213 if (tsk_is_oom_victim(current
) ||
3214 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3215 filter
&= ~SHOW_MEM_FILTER_NODES
;
3216 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3217 filter
&= ~SHOW_MEM_FILTER_NODES
;
3219 show_mem(filter
, nodemask
);
3222 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3224 struct va_format vaf
;
3226 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3227 DEFAULT_RATELIMIT_BURST
);
3229 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3232 pr_warn("%s: ", current
->comm
);
3234 va_start(args
, fmt
);
3237 pr_cont("%pV", &vaf
);
3240 pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask
, &gfp_mask
);
3242 pr_cont("%*pbl\n", nodemask_pr_args(nodemask
));
3244 pr_cont("(null)\n");
3246 cpuset_print_current_mems_allowed();
3249 warn_alloc_show_mem(gfp_mask
, nodemask
);
3252 static inline struct page
*
3253 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3254 unsigned int alloc_flags
,
3255 const struct alloc_context
*ac
)
3259 page
= get_page_from_freelist(gfp_mask
, order
,
3260 alloc_flags
|ALLOC_CPUSET
, ac
);
3262 * fallback to ignore cpuset restriction if our nodes
3266 page
= get_page_from_freelist(gfp_mask
, order
,
3272 static inline struct page
*
3273 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3274 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3276 struct oom_control oc
= {
3277 .zonelist
= ac
->zonelist
,
3278 .nodemask
= ac
->nodemask
,
3280 .gfp_mask
= gfp_mask
,
3285 *did_some_progress
= 0;
3288 * Acquire the oom lock. If that fails, somebody else is
3289 * making progress for us.
3291 if (!mutex_trylock(&oom_lock
)) {
3292 *did_some_progress
= 1;
3293 schedule_timeout_uninterruptible(1);
3298 * Go through the zonelist yet one more time, keep very high watermark
3299 * here, this is only to catch a parallel oom killing, we must fail if
3300 * we're still under heavy pressure. But make sure that this reclaim
3301 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3302 * allocation which will never fail due to oom_lock already held.
3304 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
3305 ~__GFP_DIRECT_RECLAIM
, order
,
3306 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3310 /* Coredumps can quickly deplete all memory reserves */
3311 if (current
->flags
& PF_DUMPCORE
)
3313 /* The OOM killer will not help higher order allocs */
3314 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3317 * We have already exhausted all our reclaim opportunities without any
3318 * success so it is time to admit defeat. We will skip the OOM killer
3319 * because it is very likely that the caller has a more reasonable
3320 * fallback than shooting a random task.
3322 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
3324 /* The OOM killer does not needlessly kill tasks for lowmem */
3325 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3327 if (pm_suspended_storage())
3330 * XXX: GFP_NOFS allocations should rather fail than rely on
3331 * other request to make a forward progress.
3332 * We are in an unfortunate situation where out_of_memory cannot
3333 * do much for this context but let's try it to at least get
3334 * access to memory reserved if the current task is killed (see
3335 * out_of_memory). Once filesystems are ready to handle allocation
3336 * failures more gracefully we should just bail out here.
3339 /* The OOM killer may not free memory on a specific node */
3340 if (gfp_mask
& __GFP_THISNODE
)
3343 /* Exhausted what can be done so it's blamo time */
3344 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3345 *did_some_progress
= 1;
3348 * Help non-failing allocations by giving them access to memory
3351 if (gfp_mask
& __GFP_NOFAIL
)
3352 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3353 ALLOC_NO_WATERMARKS
, ac
);
3356 mutex_unlock(&oom_lock
);
3361 * Maximum number of compaction retries wit a progress before OOM
3362 * killer is consider as the only way to move forward.
3364 #define MAX_COMPACT_RETRIES 16
3366 #ifdef CONFIG_COMPACTION
3367 /* Try memory compaction for high-order allocations before reclaim */
3368 static struct page
*
3369 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3370 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3371 enum compact_priority prio
, enum compact_result
*compact_result
)
3374 unsigned int noreclaim_flag
;
3379 noreclaim_flag
= memalloc_noreclaim_save();
3380 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3382 memalloc_noreclaim_restore(noreclaim_flag
);
3384 if (*compact_result
<= COMPACT_INACTIVE
)
3388 * At least in one zone compaction wasn't deferred or skipped, so let's
3389 * count a compaction stall
3391 count_vm_event(COMPACTSTALL
);
3393 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3396 struct zone
*zone
= page_zone(page
);
3398 zone
->compact_blockskip_flush
= false;
3399 compaction_defer_reset(zone
, order
, true);
3400 count_vm_event(COMPACTSUCCESS
);
3405 * It's bad if compaction run occurs and fails. The most likely reason
3406 * is that pages exist, but not enough to satisfy watermarks.
3408 count_vm_event(COMPACTFAIL
);
3416 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3417 enum compact_result compact_result
,
3418 enum compact_priority
*compact_priority
,
3419 int *compaction_retries
)
3421 int max_retries
= MAX_COMPACT_RETRIES
;
3424 int retries
= *compaction_retries
;
3425 enum compact_priority priority
= *compact_priority
;
3430 if (compaction_made_progress(compact_result
))
3431 (*compaction_retries
)++;
3434 * compaction considers all the zone as desperately out of memory
3435 * so it doesn't really make much sense to retry except when the
3436 * failure could be caused by insufficient priority
3438 if (compaction_failed(compact_result
))
3439 goto check_priority
;
3442 * make sure the compaction wasn't deferred or didn't bail out early
3443 * due to locks contention before we declare that we should give up.
3444 * But do not retry if the given zonelist is not suitable for
3447 if (compaction_withdrawn(compact_result
)) {
3448 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3453 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3454 * costly ones because they are de facto nofail and invoke OOM
3455 * killer to move on while costly can fail and users are ready
3456 * to cope with that. 1/4 retries is rather arbitrary but we
3457 * would need much more detailed feedback from compaction to
3458 * make a better decision.
3460 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3462 if (*compaction_retries
<= max_retries
) {
3468 * Make sure there are attempts at the highest priority if we exhausted
3469 * all retries or failed at the lower priorities.
3472 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3473 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3475 if (*compact_priority
> min_priority
) {
3476 (*compact_priority
)--;
3477 *compaction_retries
= 0;
3481 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3485 static inline struct page
*
3486 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3487 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3488 enum compact_priority prio
, enum compact_result
*compact_result
)
3490 *compact_result
= COMPACT_SKIPPED
;
3495 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3496 enum compact_result compact_result
,
3497 enum compact_priority
*compact_priority
,
3498 int *compaction_retries
)
3503 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3507 * There are setups with compaction disabled which would prefer to loop
3508 * inside the allocator rather than hit the oom killer prematurely.
3509 * Let's give them a good hope and keep retrying while the order-0
3510 * watermarks are OK.
3512 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3514 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3515 ac_classzone_idx(ac
), alloc_flags
))
3520 #endif /* CONFIG_COMPACTION */
3522 #ifdef CONFIG_LOCKDEP
3523 struct lockdep_map __fs_reclaim_map
=
3524 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
3526 static bool __need_fs_reclaim(gfp_t gfp_mask
)
3528 gfp_mask
= current_gfp_context(gfp_mask
);
3530 /* no reclaim without waiting on it */
3531 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3534 /* this guy won't enter reclaim */
3535 if (current
->flags
& PF_MEMALLOC
)
3538 /* We're only interested __GFP_FS allocations for now */
3539 if (!(gfp_mask
& __GFP_FS
))
3542 if (gfp_mask
& __GFP_NOLOCKDEP
)
3548 void fs_reclaim_acquire(gfp_t gfp_mask
)
3550 if (__need_fs_reclaim(gfp_mask
))
3551 lock_map_acquire(&__fs_reclaim_map
);
3553 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
3555 void fs_reclaim_release(gfp_t gfp_mask
)
3557 if (__need_fs_reclaim(gfp_mask
))
3558 lock_map_release(&__fs_reclaim_map
);
3560 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
3563 /* Perform direct synchronous page reclaim */
3565 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3566 const struct alloc_context
*ac
)
3568 struct reclaim_state reclaim_state
;
3570 unsigned int noreclaim_flag
;
3574 /* We now go into synchronous reclaim */
3575 cpuset_memory_pressure_bump();
3576 noreclaim_flag
= memalloc_noreclaim_save();
3577 fs_reclaim_acquire(gfp_mask
);
3578 reclaim_state
.reclaimed_slab
= 0;
3579 current
->reclaim_state
= &reclaim_state
;
3581 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3584 current
->reclaim_state
= NULL
;
3585 fs_reclaim_release(gfp_mask
);
3586 memalloc_noreclaim_restore(noreclaim_flag
);
3593 /* The really slow allocator path where we enter direct reclaim */
3594 static inline struct page
*
3595 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3596 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3597 unsigned long *did_some_progress
)
3599 struct page
*page
= NULL
;
3600 bool drained
= false;
3602 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3603 if (unlikely(!(*did_some_progress
)))
3607 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3610 * If an allocation failed after direct reclaim, it could be because
3611 * pages are pinned on the per-cpu lists or in high alloc reserves.
3612 * Shrink them them and try again
3614 if (!page
&& !drained
) {
3615 unreserve_highatomic_pageblock(ac
, false);
3616 drain_all_pages(NULL
);
3624 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3628 pg_data_t
*last_pgdat
= NULL
;
3630 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3631 ac
->high_zoneidx
, ac
->nodemask
) {
3632 if (last_pgdat
!= zone
->zone_pgdat
)
3633 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3634 last_pgdat
= zone
->zone_pgdat
;
3638 static inline unsigned int
3639 gfp_to_alloc_flags(gfp_t gfp_mask
)
3641 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3643 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3644 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3647 * The caller may dip into page reserves a bit more if the caller
3648 * cannot run direct reclaim, or if the caller has realtime scheduling
3649 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3650 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3652 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3654 if (gfp_mask
& __GFP_ATOMIC
) {
3656 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3657 * if it can't schedule.
3659 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3660 alloc_flags
|= ALLOC_HARDER
;
3662 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3663 * comment for __cpuset_node_allowed().
3665 alloc_flags
&= ~ALLOC_CPUSET
;
3666 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3667 alloc_flags
|= ALLOC_HARDER
;
3670 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3671 alloc_flags
|= ALLOC_CMA
;
3676 static bool oom_reserves_allowed(struct task_struct
*tsk
)
3678 if (!tsk_is_oom_victim(tsk
))
3682 * !MMU doesn't have oom reaper so give access to memory reserves
3683 * only to the thread with TIF_MEMDIE set
3685 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
3692 * Distinguish requests which really need access to full memory
3693 * reserves from oom victims which can live with a portion of it
3695 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
3697 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3699 if (gfp_mask
& __GFP_MEMALLOC
)
3700 return ALLOC_NO_WATERMARKS
;
3701 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3702 return ALLOC_NO_WATERMARKS
;
3703 if (!in_interrupt()) {
3704 if (current
->flags
& PF_MEMALLOC
)
3705 return ALLOC_NO_WATERMARKS
;
3706 else if (oom_reserves_allowed(current
))
3713 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3715 return !!__gfp_pfmemalloc_flags(gfp_mask
);
3719 * Checks whether it makes sense to retry the reclaim to make a forward progress
3720 * for the given allocation request.
3722 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3723 * without success, or when we couldn't even meet the watermark if we
3724 * reclaimed all remaining pages on the LRU lists.
3726 * Returns true if a retry is viable or false to enter the oom path.
3729 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3730 struct alloc_context
*ac
, int alloc_flags
,
3731 bool did_some_progress
, int *no_progress_loops
)
3737 * Costly allocations might have made a progress but this doesn't mean
3738 * their order will become available due to high fragmentation so
3739 * always increment the no progress counter for them
3741 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3742 *no_progress_loops
= 0;
3744 (*no_progress_loops
)++;
3747 * Make sure we converge to OOM if we cannot make any progress
3748 * several times in the row.
3750 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
3751 /* Before OOM, exhaust highatomic_reserve */
3752 return unreserve_highatomic_pageblock(ac
, true);
3756 * Keep reclaiming pages while there is a chance this will lead
3757 * somewhere. If none of the target zones can satisfy our allocation
3758 * request even if all reclaimable pages are considered then we are
3759 * screwed and have to go OOM.
3761 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3763 unsigned long available
;
3764 unsigned long reclaimable
;
3765 unsigned long min_wmark
= min_wmark_pages(zone
);
3768 available
= reclaimable
= zone_reclaimable_pages(zone
);
3769 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3772 * Would the allocation succeed if we reclaimed all
3773 * reclaimable pages?
3775 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
3776 ac_classzone_idx(ac
), alloc_flags
, available
);
3777 trace_reclaim_retry_zone(z
, order
, reclaimable
,
3778 available
, min_wmark
, *no_progress_loops
, wmark
);
3781 * If we didn't make any progress and have a lot of
3782 * dirty + writeback pages then we should wait for
3783 * an IO to complete to slow down the reclaim and
3784 * prevent from pre mature OOM
3786 if (!did_some_progress
) {
3787 unsigned long write_pending
;
3789 write_pending
= zone_page_state_snapshot(zone
,
3790 NR_ZONE_WRITE_PENDING
);
3792 if (2 * write_pending
> reclaimable
) {
3793 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3799 * Memory allocation/reclaim might be called from a WQ
3800 * context and the current implementation of the WQ
3801 * concurrency control doesn't recognize that
3802 * a particular WQ is congested if the worker thread is
3803 * looping without ever sleeping. Therefore we have to
3804 * do a short sleep here rather than calling
3807 if (current
->flags
& PF_WQ_WORKER
)
3808 schedule_timeout_uninterruptible(1);
3820 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
3823 * It's possible that cpuset's mems_allowed and the nodemask from
3824 * mempolicy don't intersect. This should be normally dealt with by
3825 * policy_nodemask(), but it's possible to race with cpuset update in
3826 * such a way the check therein was true, and then it became false
3827 * before we got our cpuset_mems_cookie here.
3828 * This assumes that for all allocations, ac->nodemask can come only
3829 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
3830 * when it does not intersect with the cpuset restrictions) or the
3831 * caller can deal with a violated nodemask.
3833 if (cpusets_enabled() && ac
->nodemask
&&
3834 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
3835 ac
->nodemask
= NULL
;
3840 * When updating a task's mems_allowed or mempolicy nodemask, it is
3841 * possible to race with parallel threads in such a way that our
3842 * allocation can fail while the mask is being updated. If we are about
3843 * to fail, check if the cpuset changed during allocation and if so,
3846 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3852 static inline struct page
*
3853 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3854 struct alloc_context
*ac
)
3856 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3857 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
3858 struct page
*page
= NULL
;
3859 unsigned int alloc_flags
;
3860 unsigned long did_some_progress
;
3861 enum compact_priority compact_priority
;
3862 enum compact_result compact_result
;
3863 int compaction_retries
;
3864 int no_progress_loops
;
3865 unsigned long alloc_start
= jiffies
;
3866 unsigned int stall_timeout
= 10 * HZ
;
3867 unsigned int cpuset_mems_cookie
;
3871 * In the slowpath, we sanity check order to avoid ever trying to
3872 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3873 * be using allocators in order of preference for an area that is
3876 if (order
>= MAX_ORDER
) {
3877 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3882 * We also sanity check to catch abuse of atomic reserves being used by
3883 * callers that are not in atomic context.
3885 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3886 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3887 gfp_mask
&= ~__GFP_ATOMIC
;
3890 compaction_retries
= 0;
3891 no_progress_loops
= 0;
3892 compact_priority
= DEF_COMPACT_PRIORITY
;
3893 cpuset_mems_cookie
= read_mems_allowed_begin();
3896 * The fast path uses conservative alloc_flags to succeed only until
3897 * kswapd needs to be woken up, and to avoid the cost of setting up
3898 * alloc_flags precisely. So we do that now.
3900 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3903 * We need to recalculate the starting point for the zonelist iterator
3904 * because we might have used different nodemask in the fast path, or
3905 * there was a cpuset modification and we are retrying - otherwise we
3906 * could end up iterating over non-eligible zones endlessly.
3908 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3909 ac
->high_zoneidx
, ac
->nodemask
);
3910 if (!ac
->preferred_zoneref
->zone
)
3913 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3914 wake_all_kswapds(order
, ac
);
3917 * The adjusted alloc_flags might result in immediate success, so try
3920 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3925 * For costly allocations, try direct compaction first, as it's likely
3926 * that we have enough base pages and don't need to reclaim. For non-
3927 * movable high-order allocations, do that as well, as compaction will
3928 * try prevent permanent fragmentation by migrating from blocks of the
3930 * Don't try this for allocations that are allowed to ignore
3931 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
3933 if (can_direct_reclaim
&&
3935 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
3936 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
3937 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
3939 INIT_COMPACT_PRIORITY
,
3945 * Checks for costly allocations with __GFP_NORETRY, which
3946 * includes THP page fault allocations
3948 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
3950 * If compaction is deferred for high-order allocations,
3951 * it is because sync compaction recently failed. If
3952 * this is the case and the caller requested a THP
3953 * allocation, we do not want to heavily disrupt the
3954 * system, so we fail the allocation instead of entering
3957 if (compact_result
== COMPACT_DEFERRED
)
3961 * Looks like reclaim/compaction is worth trying, but
3962 * sync compaction could be very expensive, so keep
3963 * using async compaction.
3965 compact_priority
= INIT_COMPACT_PRIORITY
;
3970 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3971 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3972 wake_all_kswapds(order
, ac
);
3974 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
3976 alloc_flags
= reserve_flags
;
3979 * Reset the zonelist iterators if memory policies can be ignored.
3980 * These allocations are high priority and system rather than user
3983 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
3984 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3985 ac
->high_zoneidx
, ac
->nodemask
);
3988 /* Attempt with potentially adjusted zonelist and alloc_flags */
3989 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3993 /* Caller is not willing to reclaim, we can't balance anything */
3994 if (!can_direct_reclaim
)
3997 /* Make sure we know about allocations which stall for too long */
3998 if (time_after(jiffies
, alloc_start
+ stall_timeout
)) {
3999 warn_alloc(gfp_mask
& ~__GFP_NOWARN
, ac
->nodemask
,
4000 "page allocation stalls for %ums, order:%u",
4001 jiffies_to_msecs(jiffies
-alloc_start
), order
);
4002 stall_timeout
+= 10 * HZ
;
4005 /* Avoid recursion of direct reclaim */
4006 if (current
->flags
& PF_MEMALLOC
)
4009 /* Try direct reclaim and then allocating */
4010 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4011 &did_some_progress
);
4015 /* Try direct compaction and then allocating */
4016 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4017 compact_priority
, &compact_result
);
4021 /* Do not loop if specifically requested */
4022 if (gfp_mask
& __GFP_NORETRY
)
4026 * Do not retry costly high order allocations unless they are
4027 * __GFP_RETRY_MAYFAIL
4029 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4032 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4033 did_some_progress
> 0, &no_progress_loops
))
4037 * It doesn't make any sense to retry for the compaction if the order-0
4038 * reclaim is not able to make any progress because the current
4039 * implementation of the compaction depends on the sufficient amount
4040 * of free memory (see __compaction_suitable)
4042 if (did_some_progress
> 0 &&
4043 should_compact_retry(ac
, order
, alloc_flags
,
4044 compact_result
, &compact_priority
,
4045 &compaction_retries
))
4049 /* Deal with possible cpuset update races before we start OOM killing */
4050 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4053 /* Reclaim has failed us, start killing things */
4054 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4058 /* Avoid allocations with no watermarks from looping endlessly */
4059 if (tsk_is_oom_victim(current
) &&
4060 (alloc_flags
== ALLOC_OOM
||
4061 (gfp_mask
& __GFP_NOMEMALLOC
)))
4064 /* Retry as long as the OOM killer is making progress */
4065 if (did_some_progress
) {
4066 no_progress_loops
= 0;
4071 /* Deal with possible cpuset update races before we fail */
4072 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4076 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4079 if (gfp_mask
& __GFP_NOFAIL
) {
4081 * All existing users of the __GFP_NOFAIL are blockable, so warn
4082 * of any new users that actually require GFP_NOWAIT
4084 if (WARN_ON_ONCE(!can_direct_reclaim
))
4088 * PF_MEMALLOC request from this context is rather bizarre
4089 * because we cannot reclaim anything and only can loop waiting
4090 * for somebody to do a work for us
4092 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4095 * non failing costly orders are a hard requirement which we
4096 * are not prepared for much so let's warn about these users
4097 * so that we can identify them and convert them to something
4100 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4103 * Help non-failing allocations by giving them access to memory
4104 * reserves but do not use ALLOC_NO_WATERMARKS because this
4105 * could deplete whole memory reserves which would just make
4106 * the situation worse
4108 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4116 warn_alloc(gfp_mask
, ac
->nodemask
,
4117 "page allocation failure: order:%u", order
);
4122 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4123 int preferred_nid
, nodemask_t
*nodemask
,
4124 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4125 unsigned int *alloc_flags
)
4127 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
4128 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4129 ac
->nodemask
= nodemask
;
4130 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
4132 if (cpusets_enabled()) {
4133 *alloc_mask
|= __GFP_HARDWALL
;
4135 ac
->nodemask
= &cpuset_current_mems_allowed
;
4137 *alloc_flags
|= ALLOC_CPUSET
;
4140 fs_reclaim_acquire(gfp_mask
);
4141 fs_reclaim_release(gfp_mask
);
4143 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4145 if (should_fail_alloc_page(gfp_mask
, order
))
4148 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
4149 *alloc_flags
|= ALLOC_CMA
;
4154 /* Determine whether to spread dirty pages and what the first usable zone */
4155 static inline void finalise_ac(gfp_t gfp_mask
,
4156 unsigned int order
, struct alloc_context
*ac
)
4158 /* Dirty zone balancing only done in the fast path */
4159 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4162 * The preferred zone is used for statistics but crucially it is
4163 * also used as the starting point for the zonelist iterator. It
4164 * may get reset for allocations that ignore memory policies.
4166 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4167 ac
->high_zoneidx
, ac
->nodemask
);
4171 * This is the 'heart' of the zoned buddy allocator.
4174 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4175 nodemask_t
*nodemask
)
4178 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4179 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4180 struct alloc_context ac
= { };
4182 gfp_mask
&= gfp_allowed_mask
;
4183 alloc_mask
= gfp_mask
;
4184 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4187 finalise_ac(gfp_mask
, order
, &ac
);
4189 /* First allocation attempt */
4190 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4195 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4196 * resp. GFP_NOIO which has to be inherited for all allocation requests
4197 * from a particular context which has been marked by
4198 * memalloc_no{fs,io}_{save,restore}.
4200 alloc_mask
= current_gfp_context(gfp_mask
);
4201 ac
.spread_dirty_pages
= false;
4204 * Restore the original nodemask if it was potentially replaced with
4205 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4207 if (unlikely(ac
.nodemask
!= nodemask
))
4208 ac
.nodemask
= nodemask
;
4210 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4213 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4214 unlikely(memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
4215 __free_pages(page
, order
);
4219 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4223 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4226 * Common helper functions.
4228 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4233 * __get_free_pages() returns a 32-bit address, which cannot represent
4236 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
4238 page
= alloc_pages(gfp_mask
, order
);
4241 return (unsigned long) page_address(page
);
4243 EXPORT_SYMBOL(__get_free_pages
);
4245 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4247 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4249 EXPORT_SYMBOL(get_zeroed_page
);
4251 void __free_pages(struct page
*page
, unsigned int order
)
4253 if (put_page_testzero(page
)) {
4255 free_hot_cold_page(page
, false);
4257 __free_pages_ok(page
, order
);
4261 EXPORT_SYMBOL(__free_pages
);
4263 void free_pages(unsigned long addr
, unsigned int order
)
4266 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4267 __free_pages(virt_to_page((void *)addr
), order
);
4271 EXPORT_SYMBOL(free_pages
);
4275 * An arbitrary-length arbitrary-offset area of memory which resides
4276 * within a 0 or higher order page. Multiple fragments within that page
4277 * are individually refcounted, in the page's reference counter.
4279 * The page_frag functions below provide a simple allocation framework for
4280 * page fragments. This is used by the network stack and network device
4281 * drivers to provide a backing region of memory for use as either an
4282 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4284 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4287 struct page
*page
= NULL
;
4288 gfp_t gfp
= gfp_mask
;
4290 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4291 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4293 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4294 PAGE_FRAG_CACHE_MAX_ORDER
);
4295 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4297 if (unlikely(!page
))
4298 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4300 nc
->va
= page
? page_address(page
) : NULL
;
4305 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4307 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4309 if (page_ref_sub_and_test(page
, count
)) {
4310 unsigned int order
= compound_order(page
);
4313 free_hot_cold_page(page
, false);
4315 __free_pages_ok(page
, order
);
4318 EXPORT_SYMBOL(__page_frag_cache_drain
);
4320 void *page_frag_alloc(struct page_frag_cache
*nc
,
4321 unsigned int fragsz
, gfp_t gfp_mask
)
4323 unsigned int size
= PAGE_SIZE
;
4327 if (unlikely(!nc
->va
)) {
4329 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4333 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4334 /* if size can vary use size else just use PAGE_SIZE */
4337 /* Even if we own the page, we do not use atomic_set().
4338 * This would break get_page_unless_zero() users.
4340 page_ref_add(page
, size
- 1);
4342 /* reset page count bias and offset to start of new frag */
4343 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4344 nc
->pagecnt_bias
= size
;
4348 offset
= nc
->offset
- fragsz
;
4349 if (unlikely(offset
< 0)) {
4350 page
= virt_to_page(nc
->va
);
4352 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4355 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4356 /* if size can vary use size else just use PAGE_SIZE */
4359 /* OK, page count is 0, we can safely set it */
4360 set_page_count(page
, size
);
4362 /* reset page count bias and offset to start of new frag */
4363 nc
->pagecnt_bias
= size
;
4364 offset
= size
- fragsz
;
4368 nc
->offset
= offset
;
4370 return nc
->va
+ offset
;
4372 EXPORT_SYMBOL(page_frag_alloc
);
4375 * Frees a page fragment allocated out of either a compound or order 0 page.
4377 void page_frag_free(void *addr
)
4379 struct page
*page
= virt_to_head_page(addr
);
4381 if (unlikely(put_page_testzero(page
)))
4382 __free_pages_ok(page
, compound_order(page
));
4384 EXPORT_SYMBOL(page_frag_free
);
4386 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4390 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4391 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4393 split_page(virt_to_page((void *)addr
), order
);
4394 while (used
< alloc_end
) {
4399 return (void *)addr
;
4403 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4404 * @size: the number of bytes to allocate
4405 * @gfp_mask: GFP flags for the allocation
4407 * This function is similar to alloc_pages(), except that it allocates the
4408 * minimum number of pages to satisfy the request. alloc_pages() can only
4409 * allocate memory in power-of-two pages.
4411 * This function is also limited by MAX_ORDER.
4413 * Memory allocated by this function must be released by free_pages_exact().
4415 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4417 unsigned int order
= get_order(size
);
4420 addr
= __get_free_pages(gfp_mask
, order
);
4421 return make_alloc_exact(addr
, order
, size
);
4423 EXPORT_SYMBOL(alloc_pages_exact
);
4426 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4428 * @nid: the preferred node ID where memory should be allocated
4429 * @size: the number of bytes to allocate
4430 * @gfp_mask: GFP flags for the allocation
4432 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4435 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4437 unsigned int order
= get_order(size
);
4438 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4441 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4445 * free_pages_exact - release memory allocated via alloc_pages_exact()
4446 * @virt: the value returned by alloc_pages_exact.
4447 * @size: size of allocation, same value as passed to alloc_pages_exact().
4449 * Release the memory allocated by a previous call to alloc_pages_exact.
4451 void free_pages_exact(void *virt
, size_t size
)
4453 unsigned long addr
= (unsigned long)virt
;
4454 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4456 while (addr
< end
) {
4461 EXPORT_SYMBOL(free_pages_exact
);
4464 * nr_free_zone_pages - count number of pages beyond high watermark
4465 * @offset: The zone index of the highest zone
4467 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4468 * high watermark within all zones at or below a given zone index. For each
4469 * zone, the number of pages is calculated as:
4471 * nr_free_zone_pages = managed_pages - high_pages
4473 static unsigned long nr_free_zone_pages(int offset
)
4478 /* Just pick one node, since fallback list is circular */
4479 unsigned long sum
= 0;
4481 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4483 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4484 unsigned long size
= zone
->managed_pages
;
4485 unsigned long high
= high_wmark_pages(zone
);
4494 * nr_free_buffer_pages - count number of pages beyond high watermark
4496 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4497 * watermark within ZONE_DMA and ZONE_NORMAL.
4499 unsigned long nr_free_buffer_pages(void)
4501 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4503 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4506 * nr_free_pagecache_pages - count number of pages beyond high watermark
4508 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4509 * high watermark within all zones.
4511 unsigned long nr_free_pagecache_pages(void)
4513 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4516 static inline void show_node(struct zone
*zone
)
4518 if (IS_ENABLED(CONFIG_NUMA
))
4519 printk("Node %d ", zone_to_nid(zone
));
4522 long si_mem_available(void)
4525 unsigned long pagecache
;
4526 unsigned long wmark_low
= 0;
4527 unsigned long pages
[NR_LRU_LISTS
];
4531 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4532 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
4535 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4538 * Estimate the amount of memory available for userspace allocations,
4539 * without causing swapping.
4541 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4544 * Not all the page cache can be freed, otherwise the system will
4545 * start swapping. Assume at least half of the page cache, or the
4546 * low watermark worth of cache, needs to stay.
4548 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4549 pagecache
-= min(pagecache
/ 2, wmark_low
);
4550 available
+= pagecache
;
4553 * Part of the reclaimable slab consists of items that are in use,
4554 * and cannot be freed. Cap this estimate at the low watermark.
4556 available
+= global_node_page_state(NR_SLAB_RECLAIMABLE
) -
4557 min(global_node_page_state(NR_SLAB_RECLAIMABLE
) / 2,
4561 * Part of the kernel memory, which can be released under memory
4564 available
+= global_node_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES
) >>
4571 EXPORT_SYMBOL_GPL(si_mem_available
);
4573 void si_meminfo(struct sysinfo
*val
)
4575 val
->totalram
= totalram_pages
;
4576 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4577 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
4578 val
->bufferram
= nr_blockdev_pages();
4579 val
->totalhigh
= totalhigh_pages
;
4580 val
->freehigh
= nr_free_highpages();
4581 val
->mem_unit
= PAGE_SIZE
;
4584 EXPORT_SYMBOL(si_meminfo
);
4587 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4589 int zone_type
; /* needs to be signed */
4590 unsigned long managed_pages
= 0;
4591 unsigned long managed_highpages
= 0;
4592 unsigned long free_highpages
= 0;
4593 pg_data_t
*pgdat
= NODE_DATA(nid
);
4595 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4596 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4597 val
->totalram
= managed_pages
;
4598 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4599 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4600 #ifdef CONFIG_HIGHMEM
4601 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4602 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4604 if (is_highmem(zone
)) {
4605 managed_highpages
+= zone
->managed_pages
;
4606 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4609 val
->totalhigh
= managed_highpages
;
4610 val
->freehigh
= free_highpages
;
4612 val
->totalhigh
= managed_highpages
;
4613 val
->freehigh
= free_highpages
;
4615 val
->mem_unit
= PAGE_SIZE
;
4620 * Determine whether the node should be displayed or not, depending on whether
4621 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4623 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
4625 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4629 * no node mask - aka implicit memory numa policy. Do not bother with
4630 * the synchronization - read_mems_allowed_begin - because we do not
4631 * have to be precise here.
4634 nodemask
= &cpuset_current_mems_allowed
;
4636 return !node_isset(nid
, *nodemask
);
4639 #define K(x) ((x) << (PAGE_SHIFT-10))
4641 static void show_migration_types(unsigned char type
)
4643 static const char types
[MIGRATE_TYPES
] = {
4644 [MIGRATE_UNMOVABLE
] = 'U',
4645 [MIGRATE_MOVABLE
] = 'M',
4646 [MIGRATE_RECLAIMABLE
] = 'E',
4647 [MIGRATE_HIGHATOMIC
] = 'H',
4649 [MIGRATE_CMA
] = 'C',
4651 #ifdef CONFIG_MEMORY_ISOLATION
4652 [MIGRATE_ISOLATE
] = 'I',
4655 char tmp
[MIGRATE_TYPES
+ 1];
4659 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4660 if (type
& (1 << i
))
4665 printk(KERN_CONT
"(%s) ", tmp
);
4669 * Show free area list (used inside shift_scroll-lock stuff)
4670 * We also calculate the percentage fragmentation. We do this by counting the
4671 * memory on each free list with the exception of the first item on the list.
4674 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4677 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
4679 unsigned long free_pcp
= 0;
4684 for_each_populated_zone(zone
) {
4685 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4688 for_each_online_cpu(cpu
)
4689 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4692 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4693 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4694 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4695 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4696 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4697 " free:%lu free_pcp:%lu free_cma:%lu\n",
4698 global_node_page_state(NR_ACTIVE_ANON
),
4699 global_node_page_state(NR_INACTIVE_ANON
),
4700 global_node_page_state(NR_ISOLATED_ANON
),
4701 global_node_page_state(NR_ACTIVE_FILE
),
4702 global_node_page_state(NR_INACTIVE_FILE
),
4703 global_node_page_state(NR_ISOLATED_FILE
),
4704 global_node_page_state(NR_UNEVICTABLE
),
4705 global_node_page_state(NR_FILE_DIRTY
),
4706 global_node_page_state(NR_WRITEBACK
),
4707 global_node_page_state(NR_UNSTABLE_NFS
),
4708 global_node_page_state(NR_SLAB_RECLAIMABLE
),
4709 global_node_page_state(NR_SLAB_UNRECLAIMABLE
),
4710 global_node_page_state(NR_FILE_MAPPED
),
4711 global_node_page_state(NR_SHMEM
),
4712 global_zone_page_state(NR_PAGETABLE
),
4713 global_zone_page_state(NR_BOUNCE
),
4714 global_zone_page_state(NR_FREE_PAGES
),
4716 global_zone_page_state(NR_FREE_CMA_PAGES
));
4718 for_each_online_pgdat(pgdat
) {
4719 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
4723 " active_anon:%lukB"
4724 " inactive_anon:%lukB"
4725 " active_file:%lukB"
4726 " inactive_file:%lukB"
4727 " unevictable:%lukB"
4728 " isolated(anon):%lukB"
4729 " isolated(file):%lukB"
4734 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4736 " shmem_pmdmapped: %lukB"
4739 " writeback_tmp:%lukB"
4741 " all_unreclaimable? %s"
4744 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4745 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4746 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4747 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4748 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4749 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4750 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4751 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4752 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4753 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4754 K(node_page_state(pgdat
, NR_SHMEM
)),
4755 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4756 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4757 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4759 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4761 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4762 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4763 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
4767 for_each_populated_zone(zone
) {
4770 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4774 for_each_online_cpu(cpu
)
4775 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4784 " active_anon:%lukB"
4785 " inactive_anon:%lukB"
4786 " active_file:%lukB"
4787 " inactive_file:%lukB"
4788 " unevictable:%lukB"
4789 " writepending:%lukB"
4793 " kernel_stack:%lukB"
4801 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4802 K(min_wmark_pages(zone
)),
4803 K(low_wmark_pages(zone
)),
4804 K(high_wmark_pages(zone
)),
4805 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4806 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4807 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4808 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4809 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4810 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4811 K(zone
->present_pages
),
4812 K(zone
->managed_pages
),
4813 K(zone_page_state(zone
, NR_MLOCK
)),
4814 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4815 K(zone_page_state(zone
, NR_PAGETABLE
)),
4816 K(zone_page_state(zone
, NR_BOUNCE
)),
4818 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4819 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4820 printk("lowmem_reserve[]:");
4821 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4822 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
4823 printk(KERN_CONT
"\n");
4826 for_each_populated_zone(zone
) {
4828 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4829 unsigned char types
[MAX_ORDER
];
4831 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4834 printk(KERN_CONT
"%s: ", zone
->name
);
4836 spin_lock_irqsave(&zone
->lock
, flags
);
4837 for (order
= 0; order
< MAX_ORDER
; order
++) {
4838 struct free_area
*area
= &zone
->free_area
[order
];
4841 nr
[order
] = area
->nr_free
;
4842 total
+= nr
[order
] << order
;
4845 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4846 if (!list_empty(&area
->free_list
[type
]))
4847 types
[order
] |= 1 << type
;
4850 spin_unlock_irqrestore(&zone
->lock
, flags
);
4851 for (order
= 0; order
< MAX_ORDER
; order
++) {
4852 printk(KERN_CONT
"%lu*%lukB ",
4853 nr
[order
], K(1UL) << order
);
4855 show_migration_types(types
[order
]);
4857 printk(KERN_CONT
"= %lukB\n", K(total
));
4860 hugetlb_show_meminfo();
4862 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4864 show_swap_cache_info();
4867 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4869 zoneref
->zone
= zone
;
4870 zoneref
->zone_idx
= zone_idx(zone
);
4874 * Builds allocation fallback zone lists.
4876 * Add all populated zones of a node to the zonelist.
4878 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
4881 enum zone_type zone_type
= MAX_NR_ZONES
;
4886 zone
= pgdat
->node_zones
+ zone_type
;
4887 if (managed_zone(zone
)) {
4888 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
4889 check_highest_zone(zone_type
);
4891 } while (zone_type
);
4898 static int __parse_numa_zonelist_order(char *s
)
4901 * We used to support different zonlists modes but they turned
4902 * out to be just not useful. Let's keep the warning in place
4903 * if somebody still use the cmd line parameter so that we do
4904 * not fail it silently
4906 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
4907 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
4913 static __init
int setup_numa_zonelist_order(char *s
)
4918 return __parse_numa_zonelist_order(s
);
4920 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4922 char numa_zonelist_order
[] = "Node";
4925 * sysctl handler for numa_zonelist_order
4927 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4928 void __user
*buffer
, size_t *length
,
4935 return proc_dostring(table
, write
, buffer
, length
, ppos
);
4936 str
= memdup_user_nul(buffer
, 16);
4938 return PTR_ERR(str
);
4940 ret
= __parse_numa_zonelist_order(str
);
4946 #define MAX_NODE_LOAD (nr_online_nodes)
4947 static int node_load
[MAX_NUMNODES
];
4950 * find_next_best_node - find the next node that should appear in a given node's fallback list
4951 * @node: node whose fallback list we're appending
4952 * @used_node_mask: nodemask_t of already used nodes
4954 * We use a number of factors to determine which is the next node that should
4955 * appear on a given node's fallback list. The node should not have appeared
4956 * already in @node's fallback list, and it should be the next closest node
4957 * according to the distance array (which contains arbitrary distance values
4958 * from each node to each node in the system), and should also prefer nodes
4959 * with no CPUs, since presumably they'll have very little allocation pressure
4960 * on them otherwise.
4961 * It returns -1 if no node is found.
4963 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4966 int min_val
= INT_MAX
;
4967 int best_node
= NUMA_NO_NODE
;
4968 const struct cpumask
*tmp
= cpumask_of_node(0);
4970 /* Use the local node if we haven't already */
4971 if (!node_isset(node
, *used_node_mask
)) {
4972 node_set(node
, *used_node_mask
);
4976 for_each_node_state(n
, N_MEMORY
) {
4978 /* Don't want a node to appear more than once */
4979 if (node_isset(n
, *used_node_mask
))
4982 /* Use the distance array to find the distance */
4983 val
= node_distance(node
, n
);
4985 /* Penalize nodes under us ("prefer the next node") */
4988 /* Give preference to headless and unused nodes */
4989 tmp
= cpumask_of_node(n
);
4990 if (!cpumask_empty(tmp
))
4991 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4993 /* Slight preference for less loaded node */
4994 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4995 val
+= node_load
[n
];
4997 if (val
< min_val
) {
5004 node_set(best_node
, *used_node_mask
);
5011 * Build zonelists ordered by node and zones within node.
5012 * This results in maximum locality--normal zone overflows into local
5013 * DMA zone, if any--but risks exhausting DMA zone.
5015 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5018 struct zoneref
*zonerefs
;
5021 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5023 for (i
= 0; i
< nr_nodes
; i
++) {
5026 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5028 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5029 zonerefs
+= nr_zones
;
5031 zonerefs
->zone
= NULL
;
5032 zonerefs
->zone_idx
= 0;
5036 * Build gfp_thisnode zonelists
5038 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5040 struct zoneref
*zonerefs
;
5043 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5044 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5045 zonerefs
+= nr_zones
;
5046 zonerefs
->zone
= NULL
;
5047 zonerefs
->zone_idx
= 0;
5051 * Build zonelists ordered by zone and nodes within zones.
5052 * This results in conserving DMA zone[s] until all Normal memory is
5053 * exhausted, but results in overflowing to remote node while memory
5054 * may still exist in local DMA zone.
5057 static void build_zonelists(pg_data_t
*pgdat
)
5059 static int node_order
[MAX_NUMNODES
];
5060 int node
, load
, nr_nodes
= 0;
5061 nodemask_t used_mask
;
5062 int local_node
, prev_node
;
5064 /* NUMA-aware ordering of nodes */
5065 local_node
= pgdat
->node_id
;
5066 load
= nr_online_nodes
;
5067 prev_node
= local_node
;
5068 nodes_clear(used_mask
);
5070 memset(node_order
, 0, sizeof(node_order
));
5071 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5073 * We don't want to pressure a particular node.
5074 * So adding penalty to the first node in same
5075 * distance group to make it round-robin.
5077 if (node_distance(local_node
, node
) !=
5078 node_distance(local_node
, prev_node
))
5079 node_load
[node
] = load
;
5081 node_order
[nr_nodes
++] = node
;
5086 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5087 build_thisnode_zonelists(pgdat
);
5090 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5092 * Return node id of node used for "local" allocations.
5093 * I.e., first node id of first zone in arg node's generic zonelist.
5094 * Used for initializing percpu 'numa_mem', which is used primarily
5095 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5097 int local_memory_node(int node
)
5101 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5102 gfp_zone(GFP_KERNEL
),
5104 return z
->zone
->node
;
5108 static void setup_min_unmapped_ratio(void);
5109 static void setup_min_slab_ratio(void);
5110 #else /* CONFIG_NUMA */
5112 static void build_zonelists(pg_data_t
*pgdat
)
5114 int node
, local_node
;
5115 struct zoneref
*zonerefs
;
5118 local_node
= pgdat
->node_id
;
5120 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5121 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5122 zonerefs
+= nr_zones
;
5125 * Now we build the zonelist so that it contains the zones
5126 * of all the other nodes.
5127 * We don't want to pressure a particular node, so when
5128 * building the zones for node N, we make sure that the
5129 * zones coming right after the local ones are those from
5130 * node N+1 (modulo N)
5132 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5133 if (!node_online(node
))
5135 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5136 zonerefs
+= nr_zones
;
5138 for (node
= 0; node
< local_node
; node
++) {
5139 if (!node_online(node
))
5141 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5142 zonerefs
+= nr_zones
;
5145 zonerefs
->zone
= NULL
;
5146 zonerefs
->zone_idx
= 0;
5149 #endif /* CONFIG_NUMA */
5152 * Boot pageset table. One per cpu which is going to be used for all
5153 * zones and all nodes. The parameters will be set in such a way
5154 * that an item put on a list will immediately be handed over to
5155 * the buddy list. This is safe since pageset manipulation is done
5156 * with interrupts disabled.
5158 * The boot_pagesets must be kept even after bootup is complete for
5159 * unused processors and/or zones. They do play a role for bootstrapping
5160 * hotplugged processors.
5162 * zoneinfo_show() and maybe other functions do
5163 * not check if the processor is online before following the pageset pointer.
5164 * Other parts of the kernel may not check if the zone is available.
5166 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5167 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5168 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5170 static void __build_all_zonelists(void *data
)
5173 int __maybe_unused cpu
;
5174 pg_data_t
*self
= data
;
5175 static DEFINE_SPINLOCK(lock
);
5180 memset(node_load
, 0, sizeof(node_load
));
5184 * This node is hotadded and no memory is yet present. So just
5185 * building zonelists is fine - no need to touch other nodes.
5187 if (self
&& !node_online(self
->node_id
)) {
5188 build_zonelists(self
);
5190 for_each_online_node(nid
) {
5191 pg_data_t
*pgdat
= NODE_DATA(nid
);
5193 build_zonelists(pgdat
);
5196 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5198 * We now know the "local memory node" for each node--
5199 * i.e., the node of the first zone in the generic zonelist.
5200 * Set up numa_mem percpu variable for on-line cpus. During
5201 * boot, only the boot cpu should be on-line; we'll init the
5202 * secondary cpus' numa_mem as they come on-line. During
5203 * node/memory hotplug, we'll fixup all on-line cpus.
5205 for_each_online_cpu(cpu
)
5206 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5213 static noinline
void __init
5214 build_all_zonelists_init(void)
5218 __build_all_zonelists(NULL
);
5221 * Initialize the boot_pagesets that are going to be used
5222 * for bootstrapping processors. The real pagesets for
5223 * each zone will be allocated later when the per cpu
5224 * allocator is available.
5226 * boot_pagesets are used also for bootstrapping offline
5227 * cpus if the system is already booted because the pagesets
5228 * are needed to initialize allocators on a specific cpu too.
5229 * F.e. the percpu allocator needs the page allocator which
5230 * needs the percpu allocator in order to allocate its pagesets
5231 * (a chicken-egg dilemma).
5233 for_each_possible_cpu(cpu
)
5234 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5236 mminit_verify_zonelist();
5237 cpuset_init_current_mems_allowed();
5241 * unless system_state == SYSTEM_BOOTING.
5243 * __ref due to call of __init annotated helper build_all_zonelists_init
5244 * [protected by SYSTEM_BOOTING].
5246 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
5248 if (system_state
== SYSTEM_BOOTING
) {
5249 build_all_zonelists_init();
5251 __build_all_zonelists(pgdat
);
5252 /* cpuset refresh routine should be here */
5254 vm_total_pages
= nr_free_pagecache_pages();
5256 * Disable grouping by mobility if the number of pages in the
5257 * system is too low to allow the mechanism to work. It would be
5258 * more accurate, but expensive to check per-zone. This check is
5259 * made on memory-hotadd so a system can start with mobility
5260 * disabled and enable it later
5262 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5263 page_group_by_mobility_disabled
= 1;
5265 page_group_by_mobility_disabled
= 0;
5267 pr_info("Built %i zonelists, mobility grouping %s. Total pages: %ld\n",
5269 page_group_by_mobility_disabled
? "off" : "on",
5272 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5277 * Initially all pages are reserved - free ones are freed
5278 * up by free_all_bootmem() once the early boot process is
5279 * done. Non-atomic initialization, single-pass.
5281 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5282 unsigned long start_pfn
, enum memmap_context context
)
5284 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5285 unsigned long end_pfn
= start_pfn
+ size
;
5286 pg_data_t
*pgdat
= NODE_DATA(nid
);
5288 unsigned long nr_initialised
= 0;
5289 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5290 struct memblock_region
*r
= NULL
, *tmp
;
5293 if (highest_memmap_pfn
< end_pfn
- 1)
5294 highest_memmap_pfn
= end_pfn
- 1;
5297 * Honor reservation requested by the driver for this ZONE_DEVICE
5300 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5301 start_pfn
+= altmap
->reserve
;
5303 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5305 * There can be holes in boot-time mem_map[]s handed to this
5306 * function. They do not exist on hotplugged memory.
5308 if (context
!= MEMMAP_EARLY
)
5311 if (!early_pfn_valid(pfn
))
5313 if (!early_pfn_in_nid(pfn
, nid
))
5315 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5318 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5320 * Check given memblock attribute by firmware which can affect
5321 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5322 * mirrored, it's an overlapped memmap init. skip it.
5324 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5325 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5326 for_each_memblock(memory
, tmp
)
5327 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5331 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5332 memblock_is_mirror(r
)) {
5333 /* already initialized as NORMAL */
5334 pfn
= memblock_region_memory_end_pfn(r
);
5342 * Mark the block movable so that blocks are reserved for
5343 * movable at startup. This will force kernel allocations
5344 * to reserve their blocks rather than leaking throughout
5345 * the address space during boot when many long-lived
5346 * kernel allocations are made.
5348 * bitmap is created for zone's valid pfn range. but memmap
5349 * can be created for invalid pages (for alignment)
5350 * check here not to call set_pageblock_migratetype() against
5353 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5354 struct page
*page
= pfn_to_page(pfn
);
5356 __init_single_page(page
, pfn
, zone
, nid
);
5357 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5360 __init_single_pfn(pfn
, zone
, nid
);
5365 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5367 unsigned int order
, t
;
5368 for_each_migratetype_order(order
, t
) {
5369 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5370 zone
->free_area
[order
].nr_free
= 0;
5374 #ifndef __HAVE_ARCH_MEMMAP_INIT
5375 #define memmap_init(size, nid, zone, start_pfn) \
5376 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5379 static int zone_batchsize(struct zone
*zone
)
5385 * The per-cpu-pages pools are set to around 1000th of the
5386 * size of the zone. But no more than 1/2 of a meg.
5388 * OK, so we don't know how big the cache is. So guess.
5390 batch
= zone
->managed_pages
/ 1024;
5391 if (batch
* PAGE_SIZE
> 512 * 1024)
5392 batch
= (512 * 1024) / PAGE_SIZE
;
5393 batch
/= 4; /* We effectively *= 4 below */
5398 * Clamp the batch to a 2^n - 1 value. Having a power
5399 * of 2 value was found to be more likely to have
5400 * suboptimal cache aliasing properties in some cases.
5402 * For example if 2 tasks are alternately allocating
5403 * batches of pages, one task can end up with a lot
5404 * of pages of one half of the possible page colors
5405 * and the other with pages of the other colors.
5407 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5412 /* The deferral and batching of frees should be suppressed under NOMMU
5415 * The problem is that NOMMU needs to be able to allocate large chunks
5416 * of contiguous memory as there's no hardware page translation to
5417 * assemble apparent contiguous memory from discontiguous pages.
5419 * Queueing large contiguous runs of pages for batching, however,
5420 * causes the pages to actually be freed in smaller chunks. As there
5421 * can be a significant delay between the individual batches being
5422 * recycled, this leads to the once large chunks of space being
5423 * fragmented and becoming unavailable for high-order allocations.
5430 * pcp->high and pcp->batch values are related and dependent on one another:
5431 * ->batch must never be higher then ->high.
5432 * The following function updates them in a safe manner without read side
5435 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5436 * those fields changing asynchronously (acording the the above rule).
5438 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5439 * outside of boot time (or some other assurance that no concurrent updaters
5442 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5443 unsigned long batch
)
5445 /* start with a fail safe value for batch */
5449 /* Update high, then batch, in order */
5456 /* a companion to pageset_set_high() */
5457 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5459 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5462 static void pageset_init(struct per_cpu_pageset
*p
)
5464 struct per_cpu_pages
*pcp
;
5467 memset(p
, 0, sizeof(*p
));
5471 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5472 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5475 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5478 pageset_set_batch(p
, batch
);
5482 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5483 * to the value high for the pageset p.
5485 static void pageset_set_high(struct per_cpu_pageset
*p
,
5488 unsigned long batch
= max(1UL, high
/ 4);
5489 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5490 batch
= PAGE_SHIFT
* 8;
5492 pageset_update(&p
->pcp
, high
, batch
);
5495 static void pageset_set_high_and_batch(struct zone
*zone
,
5496 struct per_cpu_pageset
*pcp
)
5498 if (percpu_pagelist_fraction
)
5499 pageset_set_high(pcp
,
5500 (zone
->managed_pages
/
5501 percpu_pagelist_fraction
));
5503 pageset_set_batch(pcp
, zone_batchsize(zone
));
5506 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5508 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5511 pageset_set_high_and_batch(zone
, pcp
);
5514 void __meminit
setup_zone_pageset(struct zone
*zone
)
5517 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5518 for_each_possible_cpu(cpu
)
5519 zone_pageset_init(zone
, cpu
);
5523 * Allocate per cpu pagesets and initialize them.
5524 * Before this call only boot pagesets were available.
5526 void __init
setup_per_cpu_pageset(void)
5528 struct pglist_data
*pgdat
;
5531 for_each_populated_zone(zone
)
5532 setup_zone_pageset(zone
);
5534 for_each_online_pgdat(pgdat
)
5535 pgdat
->per_cpu_nodestats
=
5536 alloc_percpu(struct per_cpu_nodestat
);
5539 static __meminit
void zone_pcp_init(struct zone
*zone
)
5542 * per cpu subsystem is not up at this point. The following code
5543 * relies on the ability of the linker to provide the
5544 * offset of a (static) per cpu variable into the per cpu area.
5546 zone
->pageset
= &boot_pageset
;
5548 if (populated_zone(zone
))
5549 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5550 zone
->name
, zone
->present_pages
,
5551 zone_batchsize(zone
));
5554 void __meminit
init_currently_empty_zone(struct zone
*zone
,
5555 unsigned long zone_start_pfn
,
5558 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5560 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5562 zone
->zone_start_pfn
= zone_start_pfn
;
5564 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5565 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5567 (unsigned long)zone_idx(zone
),
5568 zone_start_pfn
, (zone_start_pfn
+ size
));
5570 zone_init_free_lists(zone
);
5571 zone
->initialized
= 1;
5574 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5575 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5578 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5580 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5581 struct mminit_pfnnid_cache
*state
)
5583 unsigned long start_pfn
, end_pfn
;
5586 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5587 return state
->last_nid
;
5589 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5591 state
->last_start
= start_pfn
;
5592 state
->last_end
= end_pfn
;
5593 state
->last_nid
= nid
;
5598 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5601 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5602 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5603 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5605 * If an architecture guarantees that all ranges registered contain no holes
5606 * and may be freed, this this function may be used instead of calling
5607 * memblock_free_early_nid() manually.
5609 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5611 unsigned long start_pfn
, end_pfn
;
5614 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5615 start_pfn
= min(start_pfn
, max_low_pfn
);
5616 end_pfn
= min(end_pfn
, max_low_pfn
);
5618 if (start_pfn
< end_pfn
)
5619 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5620 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5626 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5627 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5629 * If an architecture guarantees that all ranges registered contain no holes and may
5630 * be freed, this function may be used instead of calling memory_present() manually.
5632 void __init
sparse_memory_present_with_active_regions(int nid
)
5634 unsigned long start_pfn
, end_pfn
;
5637 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5638 memory_present(this_nid
, start_pfn
, end_pfn
);
5642 * get_pfn_range_for_nid - Return the start and end page frames for a node
5643 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5644 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5645 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5647 * It returns the start and end page frame of a node based on information
5648 * provided by memblock_set_node(). If called for a node
5649 * with no available memory, a warning is printed and the start and end
5652 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5653 unsigned long *start_pfn
, unsigned long *end_pfn
)
5655 unsigned long this_start_pfn
, this_end_pfn
;
5661 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5662 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5663 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5666 if (*start_pfn
== -1UL)
5671 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5672 * assumption is made that zones within a node are ordered in monotonic
5673 * increasing memory addresses so that the "highest" populated zone is used
5675 static void __init
find_usable_zone_for_movable(void)
5678 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5679 if (zone_index
== ZONE_MOVABLE
)
5682 if (arch_zone_highest_possible_pfn
[zone_index
] >
5683 arch_zone_lowest_possible_pfn
[zone_index
])
5687 VM_BUG_ON(zone_index
== -1);
5688 movable_zone
= zone_index
;
5692 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5693 * because it is sized independent of architecture. Unlike the other zones,
5694 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5695 * in each node depending on the size of each node and how evenly kernelcore
5696 * is distributed. This helper function adjusts the zone ranges
5697 * provided by the architecture for a given node by using the end of the
5698 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5699 * zones within a node are in order of monotonic increases memory addresses
5701 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5702 unsigned long zone_type
,
5703 unsigned long node_start_pfn
,
5704 unsigned long node_end_pfn
,
5705 unsigned long *zone_start_pfn
,
5706 unsigned long *zone_end_pfn
)
5708 /* Only adjust if ZONE_MOVABLE is on this node */
5709 if (zone_movable_pfn
[nid
]) {
5710 /* Size ZONE_MOVABLE */
5711 if (zone_type
== ZONE_MOVABLE
) {
5712 *zone_start_pfn
= zone_movable_pfn
[nid
];
5713 *zone_end_pfn
= min(node_end_pfn
,
5714 arch_zone_highest_possible_pfn
[movable_zone
]);
5716 /* Adjust for ZONE_MOVABLE starting within this range */
5717 } else if (!mirrored_kernelcore
&&
5718 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
5719 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5720 *zone_end_pfn
= zone_movable_pfn
[nid
];
5722 /* Check if this whole range is within ZONE_MOVABLE */
5723 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5724 *zone_start_pfn
= *zone_end_pfn
;
5729 * Return the number of pages a zone spans in a node, including holes
5730 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5732 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5733 unsigned long zone_type
,
5734 unsigned long node_start_pfn
,
5735 unsigned long node_end_pfn
,
5736 unsigned long *zone_start_pfn
,
5737 unsigned long *zone_end_pfn
,
5738 unsigned long *ignored
)
5740 /* When hotadd a new node from cpu_up(), the node should be empty */
5741 if (!node_start_pfn
&& !node_end_pfn
)
5744 /* Get the start and end of the zone */
5745 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5746 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5747 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5748 node_start_pfn
, node_end_pfn
,
5749 zone_start_pfn
, zone_end_pfn
);
5751 /* Check that this node has pages within the zone's required range */
5752 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5755 /* Move the zone boundaries inside the node if necessary */
5756 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5757 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5759 /* Return the spanned pages */
5760 return *zone_end_pfn
- *zone_start_pfn
;
5764 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5765 * then all holes in the requested range will be accounted for.
5767 unsigned long __meminit
__absent_pages_in_range(int nid
,
5768 unsigned long range_start_pfn
,
5769 unsigned long range_end_pfn
)
5771 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5772 unsigned long start_pfn
, end_pfn
;
5775 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5776 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5777 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5778 nr_absent
-= end_pfn
- start_pfn
;
5784 * absent_pages_in_range - Return number of page frames in holes within a range
5785 * @start_pfn: The start PFN to start searching for holes
5786 * @end_pfn: The end PFN to stop searching for holes
5788 * It returns the number of pages frames in memory holes within a range.
5790 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5791 unsigned long end_pfn
)
5793 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5796 /* Return the number of page frames in holes in a zone on a node */
5797 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5798 unsigned long zone_type
,
5799 unsigned long node_start_pfn
,
5800 unsigned long node_end_pfn
,
5801 unsigned long *ignored
)
5803 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5804 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5805 unsigned long zone_start_pfn
, zone_end_pfn
;
5806 unsigned long nr_absent
;
5808 /* When hotadd a new node from cpu_up(), the node should be empty */
5809 if (!node_start_pfn
&& !node_end_pfn
)
5812 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5813 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5815 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5816 node_start_pfn
, node_end_pfn
,
5817 &zone_start_pfn
, &zone_end_pfn
);
5818 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5821 * ZONE_MOVABLE handling.
5822 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5825 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
5826 unsigned long start_pfn
, end_pfn
;
5827 struct memblock_region
*r
;
5829 for_each_memblock(memory
, r
) {
5830 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5831 zone_start_pfn
, zone_end_pfn
);
5832 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5833 zone_start_pfn
, zone_end_pfn
);
5835 if (zone_type
== ZONE_MOVABLE
&&
5836 memblock_is_mirror(r
))
5837 nr_absent
+= end_pfn
- start_pfn
;
5839 if (zone_type
== ZONE_NORMAL
&&
5840 !memblock_is_mirror(r
))
5841 nr_absent
+= end_pfn
- start_pfn
;
5848 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5849 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5850 unsigned long zone_type
,
5851 unsigned long node_start_pfn
,
5852 unsigned long node_end_pfn
,
5853 unsigned long *zone_start_pfn
,
5854 unsigned long *zone_end_pfn
,
5855 unsigned long *zones_size
)
5859 *zone_start_pfn
= node_start_pfn
;
5860 for (zone
= 0; zone
< zone_type
; zone
++)
5861 *zone_start_pfn
+= zones_size
[zone
];
5863 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5865 return zones_size
[zone_type
];
5868 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5869 unsigned long zone_type
,
5870 unsigned long node_start_pfn
,
5871 unsigned long node_end_pfn
,
5872 unsigned long *zholes_size
)
5877 return zholes_size
[zone_type
];
5880 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5882 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5883 unsigned long node_start_pfn
,
5884 unsigned long node_end_pfn
,
5885 unsigned long *zones_size
,
5886 unsigned long *zholes_size
)
5888 unsigned long realtotalpages
= 0, totalpages
= 0;
5891 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5892 struct zone
*zone
= pgdat
->node_zones
+ i
;
5893 unsigned long zone_start_pfn
, zone_end_pfn
;
5894 unsigned long size
, real_size
;
5896 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5902 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5903 node_start_pfn
, node_end_pfn
,
5906 zone
->zone_start_pfn
= zone_start_pfn
;
5908 zone
->zone_start_pfn
= 0;
5909 zone
->spanned_pages
= size
;
5910 zone
->present_pages
= real_size
;
5913 realtotalpages
+= real_size
;
5916 pgdat
->node_spanned_pages
= totalpages
;
5917 pgdat
->node_present_pages
= realtotalpages
;
5918 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5922 #ifndef CONFIG_SPARSEMEM
5924 * Calculate the size of the zone->blockflags rounded to an unsigned long
5925 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5926 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5927 * round what is now in bits to nearest long in bits, then return it in
5930 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5932 unsigned long usemapsize
;
5934 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5935 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5936 usemapsize
= usemapsize
>> pageblock_order
;
5937 usemapsize
*= NR_PAGEBLOCK_BITS
;
5938 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5940 return usemapsize
/ 8;
5943 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5945 unsigned long zone_start_pfn
,
5946 unsigned long zonesize
)
5948 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5949 zone
->pageblock_flags
= NULL
;
5951 zone
->pageblock_flags
=
5952 memblock_virt_alloc_node_nopanic(usemapsize
,
5956 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5957 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5958 #endif /* CONFIG_SPARSEMEM */
5960 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5962 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5963 void __paginginit
set_pageblock_order(void)
5967 /* Check that pageblock_nr_pages has not already been setup */
5968 if (pageblock_order
)
5971 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5972 order
= HUGETLB_PAGE_ORDER
;
5974 order
= MAX_ORDER
- 1;
5977 * Assume the largest contiguous order of interest is a huge page.
5978 * This value may be variable depending on boot parameters on IA64 and
5981 pageblock_order
= order
;
5983 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5986 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5987 * is unused as pageblock_order is set at compile-time. See
5988 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5991 void __paginginit
set_pageblock_order(void)
5995 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5997 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5998 unsigned long present_pages
)
6000 unsigned long pages
= spanned_pages
;
6003 * Provide a more accurate estimation if there are holes within
6004 * the zone and SPARSEMEM is in use. If there are holes within the
6005 * zone, each populated memory region may cost us one or two extra
6006 * memmap pages due to alignment because memmap pages for each
6007 * populated regions may not be naturally aligned on page boundary.
6008 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6010 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6011 IS_ENABLED(CONFIG_SPARSEMEM
))
6012 pages
= present_pages
;
6014 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6018 * Set up the zone data structures:
6019 * - mark all pages reserved
6020 * - mark all memory queues empty
6021 * - clear the memory bitmaps
6023 * NOTE: pgdat should get zeroed by caller.
6025 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
6028 int nid
= pgdat
->node_id
;
6030 pgdat_resize_init(pgdat
);
6031 #ifdef CONFIG_NUMA_BALANCING
6032 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
6033 pgdat
->numabalancing_migrate_nr_pages
= 0;
6034 pgdat
->numabalancing_migrate_next_window
= jiffies
;
6036 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6037 spin_lock_init(&pgdat
->split_queue_lock
);
6038 INIT_LIST_HEAD(&pgdat
->split_queue
);
6039 pgdat
->split_queue_len
= 0;
6041 init_waitqueue_head(&pgdat
->kswapd_wait
);
6042 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6043 #ifdef CONFIG_COMPACTION
6044 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6046 pgdat_page_ext_init(pgdat
);
6047 spin_lock_init(&pgdat
->lru_lock
);
6048 lruvec_init(node_lruvec(pgdat
));
6050 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6052 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6053 struct zone
*zone
= pgdat
->node_zones
+ j
;
6054 unsigned long size
, realsize
, freesize
, memmap_pages
;
6055 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6057 size
= zone
->spanned_pages
;
6058 realsize
= freesize
= zone
->present_pages
;
6061 * Adjust freesize so that it accounts for how much memory
6062 * is used by this zone for memmap. This affects the watermark
6063 * and per-cpu initialisations
6065 memmap_pages
= calc_memmap_size(size
, realsize
);
6066 if (!is_highmem_idx(j
)) {
6067 if (freesize
>= memmap_pages
) {
6068 freesize
-= memmap_pages
;
6071 " %s zone: %lu pages used for memmap\n",
6072 zone_names
[j
], memmap_pages
);
6074 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6075 zone_names
[j
], memmap_pages
, freesize
);
6078 /* Account for reserved pages */
6079 if (j
== 0 && freesize
> dma_reserve
) {
6080 freesize
-= dma_reserve
;
6081 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6082 zone_names
[0], dma_reserve
);
6085 if (!is_highmem_idx(j
))
6086 nr_kernel_pages
+= freesize
;
6087 /* Charge for highmem memmap if there are enough kernel pages */
6088 else if (nr_kernel_pages
> memmap_pages
* 2)
6089 nr_kernel_pages
-= memmap_pages
;
6090 nr_all_pages
+= freesize
;
6093 * Set an approximate value for lowmem here, it will be adjusted
6094 * when the bootmem allocator frees pages into the buddy system.
6095 * And all highmem pages will be managed by the buddy system.
6097 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
6101 zone
->name
= zone_names
[j
];
6102 zone
->zone_pgdat
= pgdat
;
6103 spin_lock_init(&zone
->lock
);
6104 zone_seqlock_init(zone
);
6105 zone_pcp_init(zone
);
6110 set_pageblock_order();
6111 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6112 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6113 memmap_init(size
, nid
, j
, zone_start_pfn
);
6117 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6119 unsigned long __maybe_unused start
= 0;
6120 unsigned long __maybe_unused offset
= 0;
6122 /* Skip empty nodes */
6123 if (!pgdat
->node_spanned_pages
)
6126 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6127 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6128 offset
= pgdat
->node_start_pfn
- start
;
6129 /* ia64 gets its own node_mem_map, before this, without bootmem */
6130 if (!pgdat
->node_mem_map
) {
6131 unsigned long size
, end
;
6135 * The zone's endpoints aren't required to be MAX_ORDER
6136 * aligned but the node_mem_map endpoints must be in order
6137 * for the buddy allocator to function correctly.
6139 end
= pgdat_end_pfn(pgdat
);
6140 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6141 size
= (end
- start
) * sizeof(struct page
);
6142 map
= alloc_remap(pgdat
->node_id
, size
);
6144 map
= memblock_virt_alloc_node_nopanic(size
,
6146 pgdat
->node_mem_map
= map
+ offset
;
6148 #ifndef CONFIG_NEED_MULTIPLE_NODES
6150 * With no DISCONTIG, the global mem_map is just set as node 0's
6152 if (pgdat
== NODE_DATA(0)) {
6153 mem_map
= NODE_DATA(0)->node_mem_map
;
6154 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6155 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6157 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6160 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6163 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6164 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6166 pg_data_t
*pgdat
= NODE_DATA(nid
);
6167 unsigned long start_pfn
= 0;
6168 unsigned long end_pfn
= 0;
6170 /* pg_data_t should be reset to zero when it's allocated */
6171 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6173 pgdat
->node_id
= nid
;
6174 pgdat
->node_start_pfn
= node_start_pfn
;
6175 pgdat
->per_cpu_nodestats
= NULL
;
6176 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6177 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6178 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6179 (u64
)start_pfn
<< PAGE_SHIFT
,
6180 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6182 start_pfn
= node_start_pfn
;
6184 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6185 zones_size
, zholes_size
);
6187 alloc_node_mem_map(pgdat
);
6188 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6189 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6190 nid
, (unsigned long)pgdat
,
6191 (unsigned long)pgdat
->node_mem_map
);
6194 reset_deferred_meminit(pgdat
);
6195 free_area_init_core(pgdat
);
6198 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6200 #if MAX_NUMNODES > 1
6202 * Figure out the number of possible node ids.
6204 void __init
setup_nr_node_ids(void)
6206 unsigned int highest
;
6208 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6209 nr_node_ids
= highest
+ 1;
6214 * node_map_pfn_alignment - determine the maximum internode alignment
6216 * This function should be called after node map is populated and sorted.
6217 * It calculates the maximum power of two alignment which can distinguish
6220 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6221 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6222 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6223 * shifted, 1GiB is enough and this function will indicate so.
6225 * This is used to test whether pfn -> nid mapping of the chosen memory
6226 * model has fine enough granularity to avoid incorrect mapping for the
6227 * populated node map.
6229 * Returns the determined alignment in pfn's. 0 if there is no alignment
6230 * requirement (single node).
6232 unsigned long __init
node_map_pfn_alignment(void)
6234 unsigned long accl_mask
= 0, last_end
= 0;
6235 unsigned long start
, end
, mask
;
6239 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6240 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6247 * Start with a mask granular enough to pin-point to the
6248 * start pfn and tick off bits one-by-one until it becomes
6249 * too coarse to separate the current node from the last.
6251 mask
= ~((1 << __ffs(start
)) - 1);
6252 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6255 /* accumulate all internode masks */
6259 /* convert mask to number of pages */
6260 return ~accl_mask
+ 1;
6263 /* Find the lowest pfn for a node */
6264 static unsigned long __init
find_min_pfn_for_node(int nid
)
6266 unsigned long min_pfn
= ULONG_MAX
;
6267 unsigned long start_pfn
;
6270 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6271 min_pfn
= min(min_pfn
, start_pfn
);
6273 if (min_pfn
== ULONG_MAX
) {
6274 pr_warn("Could not find start_pfn for node %d\n", nid
);
6282 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6284 * It returns the minimum PFN based on information provided via
6285 * memblock_set_node().
6287 unsigned long __init
find_min_pfn_with_active_regions(void)
6289 return find_min_pfn_for_node(MAX_NUMNODES
);
6293 * early_calculate_totalpages()
6294 * Sum pages in active regions for movable zone.
6295 * Populate N_MEMORY for calculating usable_nodes.
6297 static unsigned long __init
early_calculate_totalpages(void)
6299 unsigned long totalpages
= 0;
6300 unsigned long start_pfn
, end_pfn
;
6303 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6304 unsigned long pages
= end_pfn
- start_pfn
;
6306 totalpages
+= pages
;
6308 node_set_state(nid
, N_MEMORY
);
6314 * Find the PFN the Movable zone begins in each node. Kernel memory
6315 * is spread evenly between nodes as long as the nodes have enough
6316 * memory. When they don't, some nodes will have more kernelcore than
6319 static void __init
find_zone_movable_pfns_for_nodes(void)
6322 unsigned long usable_startpfn
;
6323 unsigned long kernelcore_node
, kernelcore_remaining
;
6324 /* save the state before borrow the nodemask */
6325 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6326 unsigned long totalpages
= early_calculate_totalpages();
6327 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6328 struct memblock_region
*r
;
6330 /* Need to find movable_zone earlier when movable_node is specified. */
6331 find_usable_zone_for_movable();
6334 * If movable_node is specified, ignore kernelcore and movablecore
6337 if (movable_node_is_enabled()) {
6338 for_each_memblock(memory
, r
) {
6339 if (!memblock_is_hotpluggable(r
))
6344 usable_startpfn
= PFN_DOWN(r
->base
);
6345 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6346 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6354 * If kernelcore=mirror is specified, ignore movablecore option
6356 if (mirrored_kernelcore
) {
6357 bool mem_below_4gb_not_mirrored
= false;
6359 for_each_memblock(memory
, r
) {
6360 if (memblock_is_mirror(r
))
6365 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6367 if (usable_startpfn
< 0x100000) {
6368 mem_below_4gb_not_mirrored
= true;
6372 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6373 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6377 if (mem_below_4gb_not_mirrored
)
6378 pr_warn("This configuration results in unmirrored kernel memory.");
6384 * If movablecore=nn[KMG] was specified, calculate what size of
6385 * kernelcore that corresponds so that memory usable for
6386 * any allocation type is evenly spread. If both kernelcore
6387 * and movablecore are specified, then the value of kernelcore
6388 * will be used for required_kernelcore if it's greater than
6389 * what movablecore would have allowed.
6391 if (required_movablecore
) {
6392 unsigned long corepages
;
6395 * Round-up so that ZONE_MOVABLE is at least as large as what
6396 * was requested by the user
6398 required_movablecore
=
6399 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6400 required_movablecore
= min(totalpages
, required_movablecore
);
6401 corepages
= totalpages
- required_movablecore
;
6403 required_kernelcore
= max(required_kernelcore
, corepages
);
6407 * If kernelcore was not specified or kernelcore size is larger
6408 * than totalpages, there is no ZONE_MOVABLE.
6410 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6413 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6414 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6417 /* Spread kernelcore memory as evenly as possible throughout nodes */
6418 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6419 for_each_node_state(nid
, N_MEMORY
) {
6420 unsigned long start_pfn
, end_pfn
;
6423 * Recalculate kernelcore_node if the division per node
6424 * now exceeds what is necessary to satisfy the requested
6425 * amount of memory for the kernel
6427 if (required_kernelcore
< kernelcore_node
)
6428 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6431 * As the map is walked, we track how much memory is usable
6432 * by the kernel using kernelcore_remaining. When it is
6433 * 0, the rest of the node is usable by ZONE_MOVABLE
6435 kernelcore_remaining
= kernelcore_node
;
6437 /* Go through each range of PFNs within this node */
6438 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6439 unsigned long size_pages
;
6441 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6442 if (start_pfn
>= end_pfn
)
6445 /* Account for what is only usable for kernelcore */
6446 if (start_pfn
< usable_startpfn
) {
6447 unsigned long kernel_pages
;
6448 kernel_pages
= min(end_pfn
, usable_startpfn
)
6451 kernelcore_remaining
-= min(kernel_pages
,
6452 kernelcore_remaining
);
6453 required_kernelcore
-= min(kernel_pages
,
6454 required_kernelcore
);
6456 /* Continue if range is now fully accounted */
6457 if (end_pfn
<= usable_startpfn
) {
6460 * Push zone_movable_pfn to the end so
6461 * that if we have to rebalance
6462 * kernelcore across nodes, we will
6463 * not double account here
6465 zone_movable_pfn
[nid
] = end_pfn
;
6468 start_pfn
= usable_startpfn
;
6472 * The usable PFN range for ZONE_MOVABLE is from
6473 * start_pfn->end_pfn. Calculate size_pages as the
6474 * number of pages used as kernelcore
6476 size_pages
= end_pfn
- start_pfn
;
6477 if (size_pages
> kernelcore_remaining
)
6478 size_pages
= kernelcore_remaining
;
6479 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6482 * Some kernelcore has been met, update counts and
6483 * break if the kernelcore for this node has been
6486 required_kernelcore
-= min(required_kernelcore
,
6488 kernelcore_remaining
-= size_pages
;
6489 if (!kernelcore_remaining
)
6495 * If there is still required_kernelcore, we do another pass with one
6496 * less node in the count. This will push zone_movable_pfn[nid] further
6497 * along on the nodes that still have memory until kernelcore is
6501 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6505 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6506 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6507 zone_movable_pfn
[nid
] =
6508 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6511 /* restore the node_state */
6512 node_states
[N_MEMORY
] = saved_node_state
;
6515 /* Any regular or high memory on that node ? */
6516 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6518 enum zone_type zone_type
;
6520 if (N_MEMORY
== N_NORMAL_MEMORY
)
6523 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6524 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6525 if (populated_zone(zone
)) {
6526 node_set_state(nid
, N_HIGH_MEMORY
);
6527 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6528 zone_type
<= ZONE_NORMAL
)
6529 node_set_state(nid
, N_NORMAL_MEMORY
);
6536 * free_area_init_nodes - Initialise all pg_data_t and zone data
6537 * @max_zone_pfn: an array of max PFNs for each zone
6539 * This will call free_area_init_node() for each active node in the system.
6540 * Using the page ranges provided by memblock_set_node(), the size of each
6541 * zone in each node and their holes is calculated. If the maximum PFN
6542 * between two adjacent zones match, it is assumed that the zone is empty.
6543 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6544 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6545 * starts where the previous one ended. For example, ZONE_DMA32 starts
6546 * at arch_max_dma_pfn.
6548 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6550 unsigned long start_pfn
, end_pfn
;
6553 /* Record where the zone boundaries are */
6554 memset(arch_zone_lowest_possible_pfn
, 0,
6555 sizeof(arch_zone_lowest_possible_pfn
));
6556 memset(arch_zone_highest_possible_pfn
, 0,
6557 sizeof(arch_zone_highest_possible_pfn
));
6559 start_pfn
= find_min_pfn_with_active_regions();
6561 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6562 if (i
== ZONE_MOVABLE
)
6565 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6566 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6567 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6569 start_pfn
= end_pfn
;
6572 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6573 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6574 find_zone_movable_pfns_for_nodes();
6576 /* Print out the zone ranges */
6577 pr_info("Zone ranges:\n");
6578 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6579 if (i
== ZONE_MOVABLE
)
6581 pr_info(" %-8s ", zone_names
[i
]);
6582 if (arch_zone_lowest_possible_pfn
[i
] ==
6583 arch_zone_highest_possible_pfn
[i
])
6586 pr_cont("[mem %#018Lx-%#018Lx]\n",
6587 (u64
)arch_zone_lowest_possible_pfn
[i
]
6589 ((u64
)arch_zone_highest_possible_pfn
[i
]
6590 << PAGE_SHIFT
) - 1);
6593 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6594 pr_info("Movable zone start for each node\n");
6595 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6596 if (zone_movable_pfn
[i
])
6597 pr_info(" Node %d: %#018Lx\n", i
,
6598 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6601 /* Print out the early node map */
6602 pr_info("Early memory node ranges\n");
6603 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6604 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6605 (u64
)start_pfn
<< PAGE_SHIFT
,
6606 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6608 /* Initialise every node */
6609 mminit_verify_pageflags_layout();
6610 setup_nr_node_ids();
6611 for_each_online_node(nid
) {
6612 pg_data_t
*pgdat
= NODE_DATA(nid
);
6613 free_area_init_node(nid
, NULL
,
6614 find_min_pfn_for_node(nid
), NULL
);
6616 /* Any memory on that node */
6617 if (pgdat
->node_present_pages
)
6618 node_set_state(nid
, N_MEMORY
);
6619 check_for_memory(pgdat
, nid
);
6623 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6625 unsigned long long coremem
;
6629 coremem
= memparse(p
, &p
);
6630 *core
= coremem
>> PAGE_SHIFT
;
6632 /* Paranoid check that UL is enough for the coremem value */
6633 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6639 * kernelcore=size sets the amount of memory for use for allocations that
6640 * cannot be reclaimed or migrated.
6642 static int __init
cmdline_parse_kernelcore(char *p
)
6644 /* parse kernelcore=mirror */
6645 if (parse_option_str(p
, "mirror")) {
6646 mirrored_kernelcore
= true;
6650 return cmdline_parse_core(p
, &required_kernelcore
);
6654 * movablecore=size sets the amount of memory for use for allocations that
6655 * can be reclaimed or migrated.
6657 static int __init
cmdline_parse_movablecore(char *p
)
6659 return cmdline_parse_core(p
, &required_movablecore
);
6662 early_param("kernelcore", cmdline_parse_kernelcore
);
6663 early_param("movablecore", cmdline_parse_movablecore
);
6665 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6667 void adjust_managed_page_count(struct page
*page
, long count
)
6669 spin_lock(&managed_page_count_lock
);
6670 page_zone(page
)->managed_pages
+= count
;
6671 totalram_pages
+= count
;
6672 #ifdef CONFIG_HIGHMEM
6673 if (PageHighMem(page
))
6674 totalhigh_pages
+= count
;
6676 spin_unlock(&managed_page_count_lock
);
6678 EXPORT_SYMBOL(adjust_managed_page_count
);
6680 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6683 unsigned long pages
= 0;
6685 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6686 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6687 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6688 if ((unsigned int)poison
<= 0xFF)
6689 memset(pos
, poison
, PAGE_SIZE
);
6690 free_reserved_page(virt_to_page(pos
));
6694 pr_info("Freeing %s memory: %ldK\n",
6695 s
, pages
<< (PAGE_SHIFT
- 10));
6699 EXPORT_SYMBOL(free_reserved_area
);
6701 #ifdef CONFIG_HIGHMEM
6702 void free_highmem_page(struct page
*page
)
6704 __free_reserved_page(page
);
6706 page_zone(page
)->managed_pages
++;
6712 void __init
mem_init_print_info(const char *str
)
6714 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6715 unsigned long init_code_size
, init_data_size
;
6717 physpages
= get_num_physpages();
6718 codesize
= _etext
- _stext
;
6719 datasize
= _edata
- _sdata
;
6720 rosize
= __end_rodata
- __start_rodata
;
6721 bss_size
= __bss_stop
- __bss_start
;
6722 init_data_size
= __init_end
- __init_begin
;
6723 init_code_size
= _einittext
- _sinittext
;
6726 * Detect special cases and adjust section sizes accordingly:
6727 * 1) .init.* may be embedded into .data sections
6728 * 2) .init.text.* may be out of [__init_begin, __init_end],
6729 * please refer to arch/tile/kernel/vmlinux.lds.S.
6730 * 3) .rodata.* may be embedded into .text or .data sections.
6732 #define adj_init_size(start, end, size, pos, adj) \
6734 if (start <= pos && pos < end && size > adj) \
6738 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6739 _sinittext
, init_code_size
);
6740 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6741 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6742 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6743 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6745 #undef adj_init_size
6747 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6748 #ifdef CONFIG_HIGHMEM
6752 nr_free_pages() << (PAGE_SHIFT
- 10),
6753 physpages
<< (PAGE_SHIFT
- 10),
6754 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6755 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6756 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6757 totalcma_pages
<< (PAGE_SHIFT
- 10),
6758 #ifdef CONFIG_HIGHMEM
6759 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6761 str
? ", " : "", str
? str
: "");
6765 * set_dma_reserve - set the specified number of pages reserved in the first zone
6766 * @new_dma_reserve: The number of pages to mark reserved
6768 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6769 * In the DMA zone, a significant percentage may be consumed by kernel image
6770 * and other unfreeable allocations which can skew the watermarks badly. This
6771 * function may optionally be used to account for unfreeable pages in the
6772 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6773 * smaller per-cpu batchsize.
6775 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6777 dma_reserve
= new_dma_reserve
;
6780 void __init
free_area_init(unsigned long *zones_size
)
6782 free_area_init_node(0, zones_size
,
6783 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6786 static int page_alloc_cpu_dead(unsigned int cpu
)
6789 lru_add_drain_cpu(cpu
);
6793 * Spill the event counters of the dead processor
6794 * into the current processors event counters.
6795 * This artificially elevates the count of the current
6798 vm_events_fold_cpu(cpu
);
6801 * Zero the differential counters of the dead processor
6802 * so that the vm statistics are consistent.
6804 * This is only okay since the processor is dead and cannot
6805 * race with what we are doing.
6807 cpu_vm_stats_fold(cpu
);
6811 void __init
page_alloc_init(void)
6815 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
6816 "mm/page_alloc:dead", NULL
,
6817 page_alloc_cpu_dead
);
6822 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6823 * or min_free_kbytes changes.
6825 static void calculate_totalreserve_pages(void)
6827 struct pglist_data
*pgdat
;
6828 unsigned long reserve_pages
= 0;
6829 enum zone_type i
, j
;
6831 for_each_online_pgdat(pgdat
) {
6833 pgdat
->totalreserve_pages
= 0;
6835 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6836 struct zone
*zone
= pgdat
->node_zones
+ i
;
6839 /* Find valid and maximum lowmem_reserve in the zone */
6840 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6841 if (zone
->lowmem_reserve
[j
] > max
)
6842 max
= zone
->lowmem_reserve
[j
];
6845 /* we treat the high watermark as reserved pages. */
6846 max
+= high_wmark_pages(zone
);
6848 if (max
> zone
->managed_pages
)
6849 max
= zone
->managed_pages
;
6851 pgdat
->totalreserve_pages
+= max
;
6853 reserve_pages
+= max
;
6856 totalreserve_pages
= reserve_pages
;
6860 * setup_per_zone_lowmem_reserve - called whenever
6861 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6862 * has a correct pages reserved value, so an adequate number of
6863 * pages are left in the zone after a successful __alloc_pages().
6865 static void setup_per_zone_lowmem_reserve(void)
6867 struct pglist_data
*pgdat
;
6868 enum zone_type j
, idx
;
6870 for_each_online_pgdat(pgdat
) {
6871 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6872 struct zone
*zone
= pgdat
->node_zones
+ j
;
6873 unsigned long managed_pages
= zone
->managed_pages
;
6875 zone
->lowmem_reserve
[j
] = 0;
6879 struct zone
*lower_zone
;
6883 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6884 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6886 lower_zone
= pgdat
->node_zones
+ idx
;
6887 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6888 sysctl_lowmem_reserve_ratio
[idx
];
6889 managed_pages
+= lower_zone
->managed_pages
;
6894 /* update totalreserve_pages */
6895 calculate_totalreserve_pages();
6898 static void __setup_per_zone_wmarks(void)
6900 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6901 unsigned long lowmem_pages
= 0;
6903 unsigned long flags
;
6905 /* Calculate total number of !ZONE_HIGHMEM pages */
6906 for_each_zone(zone
) {
6907 if (!is_highmem(zone
))
6908 lowmem_pages
+= zone
->managed_pages
;
6911 for_each_zone(zone
) {
6914 spin_lock_irqsave(&zone
->lock
, flags
);
6915 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6916 do_div(tmp
, lowmem_pages
);
6917 if (is_highmem(zone
)) {
6919 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6920 * need highmem pages, so cap pages_min to a small
6923 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6924 * deltas control asynch page reclaim, and so should
6925 * not be capped for highmem.
6927 unsigned long min_pages
;
6929 min_pages
= zone
->managed_pages
/ 1024;
6930 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6931 zone
->watermark
[WMARK_MIN
] = min_pages
;
6934 * If it's a lowmem zone, reserve a number of pages
6935 * proportionate to the zone's size.
6937 zone
->watermark
[WMARK_MIN
] = tmp
;
6941 * Set the kswapd watermarks distance according to the
6942 * scale factor in proportion to available memory, but
6943 * ensure a minimum size on small systems.
6945 tmp
= max_t(u64
, tmp
>> 2,
6946 mult_frac(zone
->managed_pages
,
6947 watermark_scale_factor
, 10000));
6949 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6950 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6952 spin_unlock_irqrestore(&zone
->lock
, flags
);
6955 /* update totalreserve_pages */
6956 calculate_totalreserve_pages();
6960 * setup_per_zone_wmarks - called when min_free_kbytes changes
6961 * or when memory is hot-{added|removed}
6963 * Ensures that the watermark[min,low,high] values for each zone are set
6964 * correctly with respect to min_free_kbytes.
6966 void setup_per_zone_wmarks(void)
6968 static DEFINE_SPINLOCK(lock
);
6971 __setup_per_zone_wmarks();
6976 * Initialise min_free_kbytes.
6978 * For small machines we want it small (128k min). For large machines
6979 * we want it large (64MB max). But it is not linear, because network
6980 * bandwidth does not increase linearly with machine size. We use
6982 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6983 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6999 int __meminit
init_per_zone_wmark_min(void)
7001 unsigned long lowmem_kbytes
;
7002 int new_min_free_kbytes
;
7004 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7005 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7007 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7008 min_free_kbytes
= new_min_free_kbytes
;
7009 if (min_free_kbytes
< 128)
7010 min_free_kbytes
= 128;
7011 if (min_free_kbytes
> 65536)
7012 min_free_kbytes
= 65536;
7014 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7015 new_min_free_kbytes
, user_min_free_kbytes
);
7017 setup_per_zone_wmarks();
7018 refresh_zone_stat_thresholds();
7019 setup_per_zone_lowmem_reserve();
7022 setup_min_unmapped_ratio();
7023 setup_min_slab_ratio();
7028 core_initcall(init_per_zone_wmark_min
)
7031 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7032 * that we can call two helper functions whenever min_free_kbytes
7035 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7036 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7040 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7045 user_min_free_kbytes
= min_free_kbytes
;
7046 setup_per_zone_wmarks();
7051 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7052 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7056 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7061 setup_per_zone_wmarks();
7067 static void setup_min_unmapped_ratio(void)
7072 for_each_online_pgdat(pgdat
)
7073 pgdat
->min_unmapped_pages
= 0;
7076 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
7077 sysctl_min_unmapped_ratio
) / 100;
7081 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7082 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7086 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7090 setup_min_unmapped_ratio();
7095 static void setup_min_slab_ratio(void)
7100 for_each_online_pgdat(pgdat
)
7101 pgdat
->min_slab_pages
= 0;
7104 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
7105 sysctl_min_slab_ratio
) / 100;
7108 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7109 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7113 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7117 setup_min_slab_ratio();
7124 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7125 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7126 * whenever sysctl_lowmem_reserve_ratio changes.
7128 * The reserve ratio obviously has absolutely no relation with the
7129 * minimum watermarks. The lowmem reserve ratio can only make sense
7130 * if in function of the boot time zone sizes.
7132 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7133 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7135 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7136 setup_per_zone_lowmem_reserve();
7141 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7142 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7143 * pagelist can have before it gets flushed back to buddy allocator.
7145 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7146 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7149 int old_percpu_pagelist_fraction
;
7152 mutex_lock(&pcp_batch_high_lock
);
7153 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7155 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7156 if (!write
|| ret
< 0)
7159 /* Sanity checking to avoid pcp imbalance */
7160 if (percpu_pagelist_fraction
&&
7161 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7162 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7168 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7171 for_each_populated_zone(zone
) {
7174 for_each_possible_cpu(cpu
)
7175 pageset_set_high_and_batch(zone
,
7176 per_cpu_ptr(zone
->pageset
, cpu
));
7179 mutex_unlock(&pcp_batch_high_lock
);
7184 int hashdist
= HASHDIST_DEFAULT
;
7186 static int __init
set_hashdist(char *str
)
7190 hashdist
= simple_strtoul(str
, &str
, 0);
7193 __setup("hashdist=", set_hashdist
);
7196 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7198 * Returns the number of pages that arch has reserved but
7199 * is not known to alloc_large_system_hash().
7201 static unsigned long __init
arch_reserved_kernel_pages(void)
7208 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7209 * machines. As memory size is increased the scale is also increased but at
7210 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7211 * quadruples the scale is increased by one, which means the size of hash table
7212 * only doubles, instead of quadrupling as well.
7213 * Because 32-bit systems cannot have large physical memory, where this scaling
7214 * makes sense, it is disabled on such platforms.
7216 #if __BITS_PER_LONG > 32
7217 #define ADAPT_SCALE_BASE (64ul << 30)
7218 #define ADAPT_SCALE_SHIFT 2
7219 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7223 * allocate a large system hash table from bootmem
7224 * - it is assumed that the hash table must contain an exact power-of-2
7225 * quantity of entries
7226 * - limit is the number of hash buckets, not the total allocation size
7228 void *__init
alloc_large_system_hash(const char *tablename
,
7229 unsigned long bucketsize
,
7230 unsigned long numentries
,
7233 unsigned int *_hash_shift
,
7234 unsigned int *_hash_mask
,
7235 unsigned long low_limit
,
7236 unsigned long high_limit
)
7238 unsigned long long max
= high_limit
;
7239 unsigned long log2qty
, size
;
7243 /* allow the kernel cmdline to have a say */
7245 /* round applicable memory size up to nearest megabyte */
7246 numentries
= nr_kernel_pages
;
7247 numentries
-= arch_reserved_kernel_pages();
7249 /* It isn't necessary when PAGE_SIZE >= 1MB */
7250 if (PAGE_SHIFT
< 20)
7251 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7253 #if __BITS_PER_LONG > 32
7255 unsigned long adapt
;
7257 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
7258 adapt
<<= ADAPT_SCALE_SHIFT
)
7263 /* limit to 1 bucket per 2^scale bytes of low memory */
7264 if (scale
> PAGE_SHIFT
)
7265 numentries
>>= (scale
- PAGE_SHIFT
);
7267 numentries
<<= (PAGE_SHIFT
- scale
);
7269 /* Make sure we've got at least a 0-order allocation.. */
7270 if (unlikely(flags
& HASH_SMALL
)) {
7271 /* Makes no sense without HASH_EARLY */
7272 WARN_ON(!(flags
& HASH_EARLY
));
7273 if (!(numentries
>> *_hash_shift
)) {
7274 numentries
= 1UL << *_hash_shift
;
7275 BUG_ON(!numentries
);
7277 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7278 numentries
= PAGE_SIZE
/ bucketsize
;
7280 numentries
= roundup_pow_of_two(numentries
);
7282 /* limit allocation size to 1/16 total memory by default */
7284 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7285 do_div(max
, bucketsize
);
7287 max
= min(max
, 0x80000000ULL
);
7289 if (numentries
< low_limit
)
7290 numentries
= low_limit
;
7291 if (numentries
> max
)
7294 log2qty
= ilog2(numentries
);
7297 * memblock allocator returns zeroed memory already, so HASH_ZERO is
7298 * currently not used when HASH_EARLY is specified.
7300 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
7302 size
= bucketsize
<< log2qty
;
7303 if (flags
& HASH_EARLY
)
7304 table
= memblock_virt_alloc_nopanic(size
, 0);
7306 table
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
7309 * If bucketsize is not a power-of-two, we may free
7310 * some pages at the end of hash table which
7311 * alloc_pages_exact() automatically does
7313 if (get_order(size
) < MAX_ORDER
) {
7314 table
= alloc_pages_exact(size
, gfp_flags
);
7315 kmemleak_alloc(table
, size
, 1, gfp_flags
);
7318 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7321 panic("Failed to allocate %s hash table\n", tablename
);
7323 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7324 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7327 *_hash_shift
= log2qty
;
7329 *_hash_mask
= (1 << log2qty
) - 1;
7335 * This function checks whether pageblock includes unmovable pages or not.
7336 * If @count is not zero, it is okay to include less @count unmovable pages
7338 * PageLRU check without isolation or lru_lock could race so that
7339 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7340 * check without lock_page also may miss some movable non-lru pages at
7341 * race condition. So you can't expect this function should be exact.
7343 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7344 bool skip_hwpoisoned_pages
)
7346 unsigned long pfn
, iter
, found
;
7350 * For avoiding noise data, lru_add_drain_all() should be called
7351 * If ZONE_MOVABLE, the zone never contains unmovable pages
7353 if (zone_idx(zone
) == ZONE_MOVABLE
)
7355 mt
= get_pageblock_migratetype(page
);
7356 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7359 pfn
= page_to_pfn(page
);
7360 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7361 unsigned long check
= pfn
+ iter
;
7363 if (!pfn_valid_within(check
))
7366 page
= pfn_to_page(check
);
7369 * Hugepages are not in LRU lists, but they're movable.
7370 * We need not scan over tail pages bacause we don't
7371 * handle each tail page individually in migration.
7373 if (PageHuge(page
)) {
7374 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7379 * We can't use page_count without pin a page
7380 * because another CPU can free compound page.
7381 * This check already skips compound tails of THP
7382 * because their page->_refcount is zero at all time.
7384 if (!page_ref_count(page
)) {
7385 if (PageBuddy(page
))
7386 iter
+= (1 << page_order(page
)) - 1;
7391 * The HWPoisoned page may be not in buddy system, and
7392 * page_count() is not 0.
7394 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7397 if (__PageMovable(page
))
7403 * If there are RECLAIMABLE pages, we need to check
7404 * it. But now, memory offline itself doesn't call
7405 * shrink_node_slabs() and it still to be fixed.
7408 * If the page is not RAM, page_count()should be 0.
7409 * we don't need more check. This is an _used_ not-movable page.
7411 * The problematic thing here is PG_reserved pages. PG_reserved
7412 * is set to both of a memory hole page and a _used_ kernel
7421 bool is_pageblock_removable_nolock(struct page
*page
)
7427 * We have to be careful here because we are iterating over memory
7428 * sections which are not zone aware so we might end up outside of
7429 * the zone but still within the section.
7430 * We have to take care about the node as well. If the node is offline
7431 * its NODE_DATA will be NULL - see page_zone.
7433 if (!node_online(page_to_nid(page
)))
7436 zone
= page_zone(page
);
7437 pfn
= page_to_pfn(page
);
7438 if (!zone_spans_pfn(zone
, pfn
))
7441 return !has_unmovable_pages(zone
, page
, 0, true);
7444 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7446 static unsigned long pfn_max_align_down(unsigned long pfn
)
7448 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7449 pageblock_nr_pages
) - 1);
7452 static unsigned long pfn_max_align_up(unsigned long pfn
)
7454 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7455 pageblock_nr_pages
));
7458 /* [start, end) must belong to a single zone. */
7459 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7460 unsigned long start
, unsigned long end
)
7462 /* This function is based on compact_zone() from compaction.c. */
7463 unsigned long nr_reclaimed
;
7464 unsigned long pfn
= start
;
7465 unsigned int tries
= 0;
7470 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7471 if (fatal_signal_pending(current
)) {
7476 if (list_empty(&cc
->migratepages
)) {
7477 cc
->nr_migratepages
= 0;
7478 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7484 } else if (++tries
== 5) {
7485 ret
= ret
< 0 ? ret
: -EBUSY
;
7489 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7491 cc
->nr_migratepages
-= nr_reclaimed
;
7493 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7494 NULL
, 0, cc
->mode
, MR_CMA
);
7497 putback_movable_pages(&cc
->migratepages
);
7504 * alloc_contig_range() -- tries to allocate given range of pages
7505 * @start: start PFN to allocate
7506 * @end: one-past-the-last PFN to allocate
7507 * @migratetype: migratetype of the underlaying pageblocks (either
7508 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7509 * in range must have the same migratetype and it must
7510 * be either of the two.
7511 * @gfp_mask: GFP mask to use during compaction
7513 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7514 * aligned, however it's the caller's responsibility to guarantee that
7515 * we are the only thread that changes migrate type of pageblocks the
7518 * The PFN range must belong to a single zone.
7520 * Returns zero on success or negative error code. On success all
7521 * pages which PFN is in [start, end) are allocated for the caller and
7522 * need to be freed with free_contig_range().
7524 int alloc_contig_range(unsigned long start
, unsigned long end
,
7525 unsigned migratetype
, gfp_t gfp_mask
)
7527 unsigned long outer_start
, outer_end
;
7531 struct compact_control cc
= {
7532 .nr_migratepages
= 0,
7534 .zone
= page_zone(pfn_to_page(start
)),
7535 .mode
= MIGRATE_SYNC
,
7536 .ignore_skip_hint
= true,
7537 .gfp_mask
= current_gfp_context(gfp_mask
),
7539 INIT_LIST_HEAD(&cc
.migratepages
);
7542 * What we do here is we mark all pageblocks in range as
7543 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7544 * have different sizes, and due to the way page allocator
7545 * work, we align the range to biggest of the two pages so
7546 * that page allocator won't try to merge buddies from
7547 * different pageblocks and change MIGRATE_ISOLATE to some
7548 * other migration type.
7550 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7551 * migrate the pages from an unaligned range (ie. pages that
7552 * we are interested in). This will put all the pages in
7553 * range back to page allocator as MIGRATE_ISOLATE.
7555 * When this is done, we take the pages in range from page
7556 * allocator removing them from the buddy system. This way
7557 * page allocator will never consider using them.
7559 * This lets us mark the pageblocks back as
7560 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7561 * aligned range but not in the unaligned, original range are
7562 * put back to page allocator so that buddy can use them.
7565 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7566 pfn_max_align_up(end
), migratetype
,
7572 * In case of -EBUSY, we'd like to know which page causes problem.
7573 * So, just fall through. test_pages_isolated() has a tracepoint
7574 * which will report the busy page.
7576 * It is possible that busy pages could become available before
7577 * the call to test_pages_isolated, and the range will actually be
7578 * allocated. So, if we fall through be sure to clear ret so that
7579 * -EBUSY is not accidentally used or returned to caller.
7581 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7582 if (ret
&& ret
!= -EBUSY
)
7587 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7588 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7589 * more, all pages in [start, end) are free in page allocator.
7590 * What we are going to do is to allocate all pages from
7591 * [start, end) (that is remove them from page allocator).
7593 * The only problem is that pages at the beginning and at the
7594 * end of interesting range may be not aligned with pages that
7595 * page allocator holds, ie. they can be part of higher order
7596 * pages. Because of this, we reserve the bigger range and
7597 * once this is done free the pages we are not interested in.
7599 * We don't have to hold zone->lock here because the pages are
7600 * isolated thus they won't get removed from buddy.
7603 lru_add_drain_all();
7604 drain_all_pages(cc
.zone
);
7607 outer_start
= start
;
7608 while (!PageBuddy(pfn_to_page(outer_start
))) {
7609 if (++order
>= MAX_ORDER
) {
7610 outer_start
= start
;
7613 outer_start
&= ~0UL << order
;
7616 if (outer_start
!= start
) {
7617 order
= page_order(pfn_to_page(outer_start
));
7620 * outer_start page could be small order buddy page and
7621 * it doesn't include start page. Adjust outer_start
7622 * in this case to report failed page properly
7623 * on tracepoint in test_pages_isolated()
7625 if (outer_start
+ (1UL << order
) <= start
)
7626 outer_start
= start
;
7629 /* Make sure the range is really isolated. */
7630 if (test_pages_isolated(outer_start
, end
, false)) {
7631 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
7632 __func__
, outer_start
, end
);
7637 /* Grab isolated pages from freelists. */
7638 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7644 /* Free head and tail (if any) */
7645 if (start
!= outer_start
)
7646 free_contig_range(outer_start
, start
- outer_start
);
7647 if (end
!= outer_end
)
7648 free_contig_range(end
, outer_end
- end
);
7651 undo_isolate_page_range(pfn_max_align_down(start
),
7652 pfn_max_align_up(end
), migratetype
);
7656 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7658 unsigned int count
= 0;
7660 for (; nr_pages
--; pfn
++) {
7661 struct page
*page
= pfn_to_page(pfn
);
7663 count
+= page_count(page
) != 1;
7666 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7670 #ifdef CONFIG_MEMORY_HOTPLUG
7672 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7673 * page high values need to be recalulated.
7675 void __meminit
zone_pcp_update(struct zone
*zone
)
7678 mutex_lock(&pcp_batch_high_lock
);
7679 for_each_possible_cpu(cpu
)
7680 pageset_set_high_and_batch(zone
,
7681 per_cpu_ptr(zone
->pageset
, cpu
));
7682 mutex_unlock(&pcp_batch_high_lock
);
7686 void zone_pcp_reset(struct zone
*zone
)
7688 unsigned long flags
;
7690 struct per_cpu_pageset
*pset
;
7692 /* avoid races with drain_pages() */
7693 local_irq_save(flags
);
7694 if (zone
->pageset
!= &boot_pageset
) {
7695 for_each_online_cpu(cpu
) {
7696 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7697 drain_zonestat(zone
, pset
);
7699 free_percpu(zone
->pageset
);
7700 zone
->pageset
= &boot_pageset
;
7702 local_irq_restore(flags
);
7705 #ifdef CONFIG_MEMORY_HOTREMOVE
7707 * All pages in the range must be in a single zone and isolated
7708 * before calling this.
7711 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7715 unsigned int order
, i
;
7717 unsigned long flags
;
7718 /* find the first valid pfn */
7719 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7724 offline_mem_sections(pfn
, end_pfn
);
7725 zone
= page_zone(pfn_to_page(pfn
));
7726 spin_lock_irqsave(&zone
->lock
, flags
);
7728 while (pfn
< end_pfn
) {
7729 if (!pfn_valid(pfn
)) {
7733 page
= pfn_to_page(pfn
);
7735 * The HWPoisoned page may be not in buddy system, and
7736 * page_count() is not 0.
7738 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7740 SetPageReserved(page
);
7744 BUG_ON(page_count(page
));
7745 BUG_ON(!PageBuddy(page
));
7746 order
= page_order(page
);
7747 #ifdef CONFIG_DEBUG_VM
7748 pr_info("remove from free list %lx %d %lx\n",
7749 pfn
, 1 << order
, end_pfn
);
7751 list_del(&page
->lru
);
7752 rmv_page_order(page
);
7753 zone
->free_area
[order
].nr_free
--;
7754 for (i
= 0; i
< (1 << order
); i
++)
7755 SetPageReserved((page
+i
));
7756 pfn
+= (1 << order
);
7758 spin_unlock_irqrestore(&zone
->lock
, flags
);
7762 bool is_free_buddy_page(struct page
*page
)
7764 struct zone
*zone
= page_zone(page
);
7765 unsigned long pfn
= page_to_pfn(page
);
7766 unsigned long flags
;
7769 spin_lock_irqsave(&zone
->lock
, flags
);
7770 for (order
= 0; order
< MAX_ORDER
; order
++) {
7771 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7773 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7776 spin_unlock_irqrestore(&zone
->lock
, flags
);
7778 return order
< MAX_ORDER
;