2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/memremap.h>
47 #include <linux/stop_machine.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page_ext.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
67 #include <asm/sections.h>
68 #include <asm/tlbflush.h>
69 #include <asm/div64.h>
72 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
73 static DEFINE_MUTEX(pcp_batch_high_lock
);
74 #define MIN_PERCPU_PAGELIST_FRACTION (8)
76 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
77 DEFINE_PER_CPU(int, numa_node
);
78 EXPORT_PER_CPU_SYMBOL(numa_node
);
81 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
83 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
84 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
85 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
86 * defined in <linux/topology.h>.
88 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
89 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
90 int _node_numa_mem_
[MAX_NUMNODES
];
94 * Array of node states.
96 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
97 [N_POSSIBLE
] = NODE_MASK_ALL
,
98 [N_ONLINE
] = { { [0] = 1UL } },
100 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
101 #ifdef CONFIG_HIGHMEM
102 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
104 #ifdef CONFIG_MOVABLE_NODE
105 [N_MEMORY
] = { { [0] = 1UL } },
107 [N_CPU
] = { { [0] = 1UL } },
110 EXPORT_SYMBOL(node_states
);
112 /* Protect totalram_pages and zone->managed_pages */
113 static DEFINE_SPINLOCK(managed_page_count_lock
);
115 unsigned long totalram_pages __read_mostly
;
116 unsigned long totalreserve_pages __read_mostly
;
117 unsigned long totalcma_pages __read_mostly
;
119 int percpu_pagelist_fraction
;
120 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
123 * A cached value of the page's pageblock's migratetype, used when the page is
124 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
125 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
126 * Also the migratetype set in the page does not necessarily match the pcplist
127 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
128 * other index - this ensures that it will be put on the correct CMA freelist.
130 static inline int get_pcppage_migratetype(struct page
*page
)
135 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
137 page
->index
= migratetype
;
140 #ifdef CONFIG_PM_SLEEP
142 * The following functions are used by the suspend/hibernate code to temporarily
143 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
144 * while devices are suspended. To avoid races with the suspend/hibernate code,
145 * they should always be called with pm_mutex held (gfp_allowed_mask also should
146 * only be modified with pm_mutex held, unless the suspend/hibernate code is
147 * guaranteed not to run in parallel with that modification).
150 static gfp_t saved_gfp_mask
;
152 void pm_restore_gfp_mask(void)
154 WARN_ON(!mutex_is_locked(&pm_mutex
));
155 if (saved_gfp_mask
) {
156 gfp_allowed_mask
= saved_gfp_mask
;
161 void pm_restrict_gfp_mask(void)
163 WARN_ON(!mutex_is_locked(&pm_mutex
));
164 WARN_ON(saved_gfp_mask
);
165 saved_gfp_mask
= gfp_allowed_mask
;
166 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
169 bool pm_suspended_storage(void)
171 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
175 #endif /* CONFIG_PM_SLEEP */
177 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
178 unsigned int pageblock_order __read_mostly
;
181 static void __free_pages_ok(struct page
*page
, unsigned int order
);
184 * results with 256, 32 in the lowmem_reserve sysctl:
185 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
186 * 1G machine -> (16M dma, 784M normal, 224M high)
187 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
188 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
189 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
191 * TBD: should special case ZONE_DMA32 machines here - in those we normally
192 * don't need any ZONE_NORMAL reservation
194 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
195 #ifdef CONFIG_ZONE_DMA
198 #ifdef CONFIG_ZONE_DMA32
201 #ifdef CONFIG_HIGHMEM
207 EXPORT_SYMBOL(totalram_pages
);
209 static char * const zone_names
[MAX_NR_ZONES
] = {
210 #ifdef CONFIG_ZONE_DMA
213 #ifdef CONFIG_ZONE_DMA32
217 #ifdef CONFIG_HIGHMEM
221 #ifdef CONFIG_ZONE_DEVICE
226 char * const migratetype_names
[MIGRATE_TYPES
] = {
234 #ifdef CONFIG_MEMORY_ISOLATION
239 compound_page_dtor
* const compound_page_dtors
[] = {
242 #ifdef CONFIG_HUGETLB_PAGE
245 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
250 int min_free_kbytes
= 1024;
251 int user_min_free_kbytes
= -1;
252 int watermark_scale_factor
= 10;
254 static unsigned long __meminitdata nr_kernel_pages
;
255 static unsigned long __meminitdata nr_all_pages
;
256 static unsigned long __meminitdata dma_reserve
;
258 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
259 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
260 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
261 static unsigned long __initdata required_kernelcore
;
262 static unsigned long __initdata required_movablecore
;
263 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
264 static bool mirrored_kernelcore
;
266 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
268 EXPORT_SYMBOL(movable_zone
);
269 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
272 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
273 int nr_online_nodes __read_mostly
= 1;
274 EXPORT_SYMBOL(nr_node_ids
);
275 EXPORT_SYMBOL(nr_online_nodes
);
278 int page_group_by_mobility_disabled __read_mostly
;
280 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
281 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
283 pgdat
->first_deferred_pfn
= ULONG_MAX
;
286 /* Returns true if the struct page for the pfn is uninitialised */
287 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
289 if (pfn
>= NODE_DATA(early_pfn_to_nid(pfn
))->first_deferred_pfn
)
295 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
297 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
304 * Returns false when the remaining initialisation should be deferred until
305 * later in the boot cycle when it can be parallelised.
307 static inline bool update_defer_init(pg_data_t
*pgdat
,
308 unsigned long pfn
, unsigned long zone_end
,
309 unsigned long *nr_initialised
)
311 unsigned long max_initialise
;
313 /* Always populate low zones for address-contrained allocations */
314 if (zone_end
< pgdat_end_pfn(pgdat
))
317 * Initialise at least 2G of a node but also take into account that
318 * two large system hashes that can take up 1GB for 0.25TB/node.
320 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
321 (pgdat
->node_spanned_pages
>> 8));
324 if ((*nr_initialised
> max_initialise
) &&
325 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
326 pgdat
->first_deferred_pfn
= pfn
;
333 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
337 static inline bool early_page_uninitialised(unsigned long pfn
)
342 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
347 static inline bool update_defer_init(pg_data_t
*pgdat
,
348 unsigned long pfn
, unsigned long zone_end
,
349 unsigned long *nr_initialised
)
355 /* Return a pointer to the bitmap storing bits affecting a block of pages */
356 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
359 #ifdef CONFIG_SPARSEMEM
360 return __pfn_to_section(pfn
)->pageblock_flags
;
362 return page_zone(page
)->pageblock_flags
;
363 #endif /* CONFIG_SPARSEMEM */
366 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
368 #ifdef CONFIG_SPARSEMEM
369 pfn
&= (PAGES_PER_SECTION
-1);
370 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
372 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
373 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
374 #endif /* CONFIG_SPARSEMEM */
378 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
379 * @page: The page within the block of interest
380 * @pfn: The target page frame number
381 * @end_bitidx: The last bit of interest to retrieve
382 * @mask: mask of bits that the caller is interested in
384 * Return: pageblock_bits flags
386 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
388 unsigned long end_bitidx
,
391 unsigned long *bitmap
;
392 unsigned long bitidx
, word_bitidx
;
395 bitmap
= get_pageblock_bitmap(page
, pfn
);
396 bitidx
= pfn_to_bitidx(page
, pfn
);
397 word_bitidx
= bitidx
/ BITS_PER_LONG
;
398 bitidx
&= (BITS_PER_LONG
-1);
400 word
= bitmap
[word_bitidx
];
401 bitidx
+= end_bitidx
;
402 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
405 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
406 unsigned long end_bitidx
,
409 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
412 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
414 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
418 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
419 * @page: The page within the block of interest
420 * @flags: The flags to set
421 * @pfn: The target page frame number
422 * @end_bitidx: The last bit of interest
423 * @mask: mask of bits that the caller is interested in
425 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
427 unsigned long end_bitidx
,
430 unsigned long *bitmap
;
431 unsigned long bitidx
, word_bitidx
;
432 unsigned long old_word
, word
;
434 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
436 bitmap
= get_pageblock_bitmap(page
, pfn
);
437 bitidx
= pfn_to_bitidx(page
, pfn
);
438 word_bitidx
= bitidx
/ BITS_PER_LONG
;
439 bitidx
&= (BITS_PER_LONG
-1);
441 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
443 bitidx
+= end_bitidx
;
444 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
445 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
447 word
= READ_ONCE(bitmap
[word_bitidx
]);
449 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
450 if (word
== old_word
)
456 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
458 if (unlikely(page_group_by_mobility_disabled
&&
459 migratetype
< MIGRATE_PCPTYPES
))
460 migratetype
= MIGRATE_UNMOVABLE
;
462 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
463 PB_migrate
, PB_migrate_end
);
466 #ifdef CONFIG_DEBUG_VM
467 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
471 unsigned long pfn
= page_to_pfn(page
);
472 unsigned long sp
, start_pfn
;
475 seq
= zone_span_seqbegin(zone
);
476 start_pfn
= zone
->zone_start_pfn
;
477 sp
= zone
->spanned_pages
;
478 if (!zone_spans_pfn(zone
, pfn
))
480 } while (zone_span_seqretry(zone
, seq
));
483 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
484 pfn
, zone_to_nid(zone
), zone
->name
,
485 start_pfn
, start_pfn
+ sp
);
490 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
492 if (!pfn_valid_within(page_to_pfn(page
)))
494 if (zone
!= page_zone(page
))
500 * Temporary debugging check for pages not lying within a given zone.
502 static int bad_range(struct zone
*zone
, struct page
*page
)
504 if (page_outside_zone_boundaries(zone
, page
))
506 if (!page_is_consistent(zone
, page
))
512 static inline int bad_range(struct zone
*zone
, struct page
*page
)
518 static void bad_page(struct page
*page
, const char *reason
,
519 unsigned long bad_flags
)
521 static unsigned long resume
;
522 static unsigned long nr_shown
;
523 static unsigned long nr_unshown
;
525 /* Don't complain about poisoned pages */
526 if (PageHWPoison(page
)) {
527 page_mapcount_reset(page
); /* remove PageBuddy */
532 * Allow a burst of 60 reports, then keep quiet for that minute;
533 * or allow a steady drip of one report per second.
535 if (nr_shown
== 60) {
536 if (time_before(jiffies
, resume
)) {
542 "BUG: Bad page state: %lu messages suppressed\n",
549 resume
= jiffies
+ 60 * HZ
;
551 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
552 current
->comm
, page_to_pfn(page
));
553 __dump_page(page
, reason
);
554 bad_flags
&= page
->flags
;
556 pr_alert("bad because of flags: %#lx(%pGp)\n",
557 bad_flags
, &bad_flags
);
558 dump_page_owner(page
);
563 /* Leave bad fields for debug, except PageBuddy could make trouble */
564 page_mapcount_reset(page
); /* remove PageBuddy */
565 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
569 * Higher-order pages are called "compound pages". They are structured thusly:
571 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
573 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
574 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
576 * The first tail page's ->compound_dtor holds the offset in array of compound
577 * page destructors. See compound_page_dtors.
579 * The first tail page's ->compound_order holds the order of allocation.
580 * This usage means that zero-order pages may not be compound.
583 void free_compound_page(struct page
*page
)
585 __free_pages_ok(page
, compound_order(page
));
588 void prep_compound_page(struct page
*page
, unsigned int order
)
591 int nr_pages
= 1 << order
;
593 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
594 set_compound_order(page
, order
);
596 for (i
= 1; i
< nr_pages
; i
++) {
597 struct page
*p
= page
+ i
;
598 set_page_count(p
, 0);
599 p
->mapping
= TAIL_MAPPING
;
600 set_compound_head(p
, page
);
602 atomic_set(compound_mapcount_ptr(page
), -1);
605 #ifdef CONFIG_DEBUG_PAGEALLOC
606 unsigned int _debug_guardpage_minorder
;
607 bool _debug_pagealloc_enabled __read_mostly
608 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
609 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
610 bool _debug_guardpage_enabled __read_mostly
;
612 static int __init
early_debug_pagealloc(char *buf
)
617 if (strcmp(buf
, "on") == 0)
618 _debug_pagealloc_enabled
= true;
620 if (strcmp(buf
, "off") == 0)
621 _debug_pagealloc_enabled
= false;
625 early_param("debug_pagealloc", early_debug_pagealloc
);
627 static bool need_debug_guardpage(void)
629 /* If we don't use debug_pagealloc, we don't need guard page */
630 if (!debug_pagealloc_enabled())
636 static void init_debug_guardpage(void)
638 if (!debug_pagealloc_enabled())
641 _debug_guardpage_enabled
= true;
644 struct page_ext_operations debug_guardpage_ops
= {
645 .need
= need_debug_guardpage
,
646 .init
= init_debug_guardpage
,
649 static int __init
debug_guardpage_minorder_setup(char *buf
)
653 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
654 pr_err("Bad debug_guardpage_minorder value\n");
657 _debug_guardpage_minorder
= res
;
658 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
661 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
663 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
664 unsigned int order
, int migratetype
)
666 struct page_ext
*page_ext
;
668 if (!debug_guardpage_enabled())
671 page_ext
= lookup_page_ext(page
);
672 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
674 INIT_LIST_HEAD(&page
->lru
);
675 set_page_private(page
, order
);
676 /* Guard pages are not available for any usage */
677 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
680 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
681 unsigned int order
, int migratetype
)
683 struct page_ext
*page_ext
;
685 if (!debug_guardpage_enabled())
688 page_ext
= lookup_page_ext(page
);
689 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
691 set_page_private(page
, 0);
692 if (!is_migrate_isolate(migratetype
))
693 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
696 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
697 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
698 unsigned int order
, int migratetype
) {}
699 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
700 unsigned int order
, int migratetype
) {}
703 static inline void set_page_order(struct page
*page
, unsigned int order
)
705 set_page_private(page
, order
);
706 __SetPageBuddy(page
);
709 static inline void rmv_page_order(struct page
*page
)
711 __ClearPageBuddy(page
);
712 set_page_private(page
, 0);
716 * This function checks whether a page is free && is the buddy
717 * we can do coalesce a page and its buddy if
718 * (a) the buddy is not in a hole &&
719 * (b) the buddy is in the buddy system &&
720 * (c) a page and its buddy have the same order &&
721 * (d) a page and its buddy are in the same zone.
723 * For recording whether a page is in the buddy system, we set ->_mapcount
724 * PAGE_BUDDY_MAPCOUNT_VALUE.
725 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
726 * serialized by zone->lock.
728 * For recording page's order, we use page_private(page).
730 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
733 if (!pfn_valid_within(page_to_pfn(buddy
)))
736 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
737 if (page_zone_id(page
) != page_zone_id(buddy
))
740 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
745 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
747 * zone check is done late to avoid uselessly
748 * calculating zone/node ids for pages that could
751 if (page_zone_id(page
) != page_zone_id(buddy
))
754 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
762 * Freeing function for a buddy system allocator.
764 * The concept of a buddy system is to maintain direct-mapped table
765 * (containing bit values) for memory blocks of various "orders".
766 * The bottom level table contains the map for the smallest allocatable
767 * units of memory (here, pages), and each level above it describes
768 * pairs of units from the levels below, hence, "buddies".
769 * At a high level, all that happens here is marking the table entry
770 * at the bottom level available, and propagating the changes upward
771 * as necessary, plus some accounting needed to play nicely with other
772 * parts of the VM system.
773 * At each level, we keep a list of pages, which are heads of continuous
774 * free pages of length of (1 << order) and marked with _mapcount
775 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
777 * So when we are allocating or freeing one, we can derive the state of the
778 * other. That is, if we allocate a small block, and both were
779 * free, the remainder of the region must be split into blocks.
780 * If a block is freed, and its buddy is also free, then this
781 * triggers coalescing into a block of larger size.
786 static inline void __free_one_page(struct page
*page
,
788 struct zone
*zone
, unsigned int order
,
791 unsigned long page_idx
;
792 unsigned long combined_idx
;
793 unsigned long uninitialized_var(buddy_idx
);
795 unsigned int max_order
;
797 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
799 VM_BUG_ON(!zone_is_initialized(zone
));
800 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
802 VM_BUG_ON(migratetype
== -1);
803 if (likely(!is_migrate_isolate(migratetype
)))
804 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
806 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
808 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
809 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
812 while (order
< max_order
- 1) {
813 buddy_idx
= __find_buddy_index(page_idx
, order
);
814 buddy
= page
+ (buddy_idx
- page_idx
);
815 if (!page_is_buddy(page
, buddy
, order
))
818 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
819 * merge with it and move up one order.
821 if (page_is_guard(buddy
)) {
822 clear_page_guard(zone
, buddy
, order
, migratetype
);
824 list_del(&buddy
->lru
);
825 zone
->free_area
[order
].nr_free
--;
826 rmv_page_order(buddy
);
828 combined_idx
= buddy_idx
& page_idx
;
829 page
= page
+ (combined_idx
- page_idx
);
830 page_idx
= combined_idx
;
833 if (max_order
< MAX_ORDER
) {
834 /* If we are here, it means order is >= pageblock_order.
835 * We want to prevent merge between freepages on isolate
836 * pageblock and normal pageblock. Without this, pageblock
837 * isolation could cause incorrect freepage or CMA accounting.
839 * We don't want to hit this code for the more frequent
842 if (unlikely(has_isolate_pageblock(zone
))) {
845 buddy_idx
= __find_buddy_index(page_idx
, order
);
846 buddy
= page
+ (buddy_idx
- page_idx
);
847 buddy_mt
= get_pageblock_migratetype(buddy
);
849 if (migratetype
!= buddy_mt
850 && (is_migrate_isolate(migratetype
) ||
851 is_migrate_isolate(buddy_mt
)))
855 goto continue_merging
;
859 set_page_order(page
, order
);
862 * If this is not the largest possible page, check if the buddy
863 * of the next-highest order is free. If it is, it's possible
864 * that pages are being freed that will coalesce soon. In case,
865 * that is happening, add the free page to the tail of the list
866 * so it's less likely to be used soon and more likely to be merged
867 * as a higher order page
869 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
870 struct page
*higher_page
, *higher_buddy
;
871 combined_idx
= buddy_idx
& page_idx
;
872 higher_page
= page
+ (combined_idx
- page_idx
);
873 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
874 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
875 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
876 list_add_tail(&page
->lru
,
877 &zone
->free_area
[order
].free_list
[migratetype
]);
882 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
884 zone
->free_area
[order
].nr_free
++;
888 * A bad page could be due to a number of fields. Instead of multiple branches,
889 * try and check multiple fields with one check. The caller must do a detailed
890 * check if necessary.
892 static inline bool page_expected_state(struct page
*page
,
893 unsigned long check_flags
)
895 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
898 if (unlikely((unsigned long)page
->mapping
|
899 page_ref_count(page
) |
901 (unsigned long)page
->mem_cgroup
|
903 (page
->flags
& check_flags
)))
909 static void free_pages_check_bad(struct page
*page
)
911 const char *bad_reason
;
912 unsigned long bad_flags
;
917 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
918 bad_reason
= "nonzero mapcount";
919 if (unlikely(page
->mapping
!= NULL
))
920 bad_reason
= "non-NULL mapping";
921 if (unlikely(page_ref_count(page
) != 0))
922 bad_reason
= "nonzero _refcount";
923 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
924 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
925 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
928 if (unlikely(page
->mem_cgroup
))
929 bad_reason
= "page still charged to cgroup";
931 bad_page(page
, bad_reason
, bad_flags
);
934 static inline int free_pages_check(struct page
*page
)
936 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
939 /* Something has gone sideways, find it */
940 free_pages_check_bad(page
);
944 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
949 * We rely page->lru.next never has bit 0 set, unless the page
950 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
952 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
954 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
958 switch (page
- head_page
) {
960 /* the first tail page: ->mapping is compound_mapcount() */
961 if (unlikely(compound_mapcount(page
))) {
962 bad_page(page
, "nonzero compound_mapcount", 0);
968 * the second tail page: ->mapping is
969 * page_deferred_list().next -- ignore value.
973 if (page
->mapping
!= TAIL_MAPPING
) {
974 bad_page(page
, "corrupted mapping in tail page", 0);
979 if (unlikely(!PageTail(page
))) {
980 bad_page(page
, "PageTail not set", 0);
983 if (unlikely(compound_head(page
) != head_page
)) {
984 bad_page(page
, "compound_head not consistent", 0);
989 page
->mapping
= NULL
;
990 clear_compound_head(page
);
994 static __always_inline
bool free_pages_prepare(struct page
*page
,
995 unsigned int order
, bool check_free
)
999 VM_BUG_ON_PAGE(PageTail(page
), page
);
1001 trace_mm_page_free(page
, order
);
1002 kmemcheck_free_shadow(page
, order
);
1003 kasan_free_pages(page
, order
);
1006 * Check tail pages before head page information is cleared to
1007 * avoid checking PageCompound for order-0 pages.
1009 if (unlikely(order
)) {
1010 bool compound
= PageCompound(page
);
1013 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1015 for (i
= 1; i
< (1 << order
); i
++) {
1017 bad
+= free_tail_pages_check(page
, page
+ i
);
1018 if (unlikely(free_pages_check(page
+ i
))) {
1022 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1025 if (PageAnonHead(page
))
1026 page
->mapping
= NULL
;
1028 bad
+= free_pages_check(page
);
1032 page_cpupid_reset_last(page
);
1033 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1034 reset_page_owner(page
, order
);
1036 if (!PageHighMem(page
)) {
1037 debug_check_no_locks_freed(page_address(page
),
1038 PAGE_SIZE
<< order
);
1039 debug_check_no_obj_freed(page_address(page
),
1040 PAGE_SIZE
<< order
);
1042 arch_free_page(page
, order
);
1043 kernel_poison_pages(page
, 1 << order
, 0);
1044 kernel_map_pages(page
, 1 << order
, 0);
1049 #ifdef CONFIG_DEBUG_VM
1050 static inline bool free_pcp_prepare(struct page
*page
)
1052 return free_pages_prepare(page
, 0, true);
1055 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1060 static bool free_pcp_prepare(struct page
*page
)
1062 return free_pages_prepare(page
, 0, false);
1065 static bool bulkfree_pcp_prepare(struct page
*page
)
1067 return free_pages_check(page
);
1069 #endif /* CONFIG_DEBUG_VM */
1072 * Frees a number of pages from the PCP lists
1073 * Assumes all pages on list are in same zone, and of same order.
1074 * count is the number of pages to free.
1076 * If the zone was previously in an "all pages pinned" state then look to
1077 * see if this freeing clears that state.
1079 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1080 * pinned" detection logic.
1082 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1083 struct per_cpu_pages
*pcp
)
1085 int migratetype
= 0;
1087 unsigned long nr_scanned
;
1088 bool isolated_pageblocks
;
1090 spin_lock(&zone
->lock
);
1091 isolated_pageblocks
= has_isolate_pageblock(zone
);
1092 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
1094 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
1098 struct list_head
*list
;
1101 * Remove pages from lists in a round-robin fashion. A
1102 * batch_free count is maintained that is incremented when an
1103 * empty list is encountered. This is so more pages are freed
1104 * off fuller lists instead of spinning excessively around empty
1109 if (++migratetype
== MIGRATE_PCPTYPES
)
1111 list
= &pcp
->lists
[migratetype
];
1112 } while (list_empty(list
));
1114 /* This is the only non-empty list. Free them all. */
1115 if (batch_free
== MIGRATE_PCPTYPES
)
1119 int mt
; /* migratetype of the to-be-freed page */
1121 page
= list_last_entry(list
, struct page
, lru
);
1122 /* must delete as __free_one_page list manipulates */
1123 list_del(&page
->lru
);
1125 mt
= get_pcppage_migratetype(page
);
1126 /* MIGRATE_ISOLATE page should not go to pcplists */
1127 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1128 /* Pageblock could have been isolated meanwhile */
1129 if (unlikely(isolated_pageblocks
))
1130 mt
= get_pageblock_migratetype(page
);
1132 if (bulkfree_pcp_prepare(page
))
1135 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1136 trace_mm_page_pcpu_drain(page
, 0, mt
);
1137 } while (--count
&& --batch_free
&& !list_empty(list
));
1139 spin_unlock(&zone
->lock
);
1142 static void free_one_page(struct zone
*zone
,
1143 struct page
*page
, unsigned long pfn
,
1147 unsigned long nr_scanned
;
1148 spin_lock(&zone
->lock
);
1149 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
1151 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
1153 if (unlikely(has_isolate_pageblock(zone
) ||
1154 is_migrate_isolate(migratetype
))) {
1155 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1157 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1158 spin_unlock(&zone
->lock
);
1161 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1162 unsigned long zone
, int nid
)
1164 set_page_links(page
, zone
, nid
, pfn
);
1165 init_page_count(page
);
1166 page_mapcount_reset(page
);
1167 page_cpupid_reset_last(page
);
1169 INIT_LIST_HEAD(&page
->lru
);
1170 #ifdef WANT_PAGE_VIRTUAL
1171 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1172 if (!is_highmem_idx(zone
))
1173 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1177 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1180 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1183 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1184 static void init_reserved_page(unsigned long pfn
)
1189 if (!early_page_uninitialised(pfn
))
1192 nid
= early_pfn_to_nid(pfn
);
1193 pgdat
= NODE_DATA(nid
);
1195 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1196 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1198 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1201 __init_single_pfn(pfn
, zid
, nid
);
1204 static inline void init_reserved_page(unsigned long pfn
)
1207 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1210 * Initialised pages do not have PageReserved set. This function is
1211 * called for each range allocated by the bootmem allocator and
1212 * marks the pages PageReserved. The remaining valid pages are later
1213 * sent to the buddy page allocator.
1215 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
1217 unsigned long start_pfn
= PFN_DOWN(start
);
1218 unsigned long end_pfn
= PFN_UP(end
);
1220 for (; start_pfn
< end_pfn
; start_pfn
++) {
1221 if (pfn_valid(start_pfn
)) {
1222 struct page
*page
= pfn_to_page(start_pfn
);
1224 init_reserved_page(start_pfn
);
1226 /* Avoid false-positive PageTail() */
1227 INIT_LIST_HEAD(&page
->lru
);
1229 SetPageReserved(page
);
1234 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1236 unsigned long flags
;
1238 unsigned long pfn
= page_to_pfn(page
);
1240 if (!free_pages_prepare(page
, order
, true))
1243 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1244 local_irq_save(flags
);
1245 __count_vm_events(PGFREE
, 1 << order
);
1246 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1247 local_irq_restore(flags
);
1250 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1252 unsigned int nr_pages
= 1 << order
;
1253 struct page
*p
= page
;
1257 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1259 __ClearPageReserved(p
);
1260 set_page_count(p
, 0);
1262 __ClearPageReserved(p
);
1263 set_page_count(p
, 0);
1265 page_zone(page
)->managed_pages
+= nr_pages
;
1266 set_page_refcounted(page
);
1267 __free_pages(page
, order
);
1270 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1271 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1273 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1275 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1277 static DEFINE_SPINLOCK(early_pfn_lock
);
1280 spin_lock(&early_pfn_lock
);
1281 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1284 spin_unlock(&early_pfn_lock
);
1290 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1291 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1292 struct mminit_pfnnid_cache
*state
)
1296 nid
= __early_pfn_to_nid(pfn
, state
);
1297 if (nid
>= 0 && nid
!= node
)
1302 /* Only safe to use early in boot when initialisation is single-threaded */
1303 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1305 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1310 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1314 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1315 struct mminit_pfnnid_cache
*state
)
1322 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1325 if (early_page_uninitialised(pfn
))
1327 return __free_pages_boot_core(page
, order
);
1331 * Check that the whole (or subset of) a pageblock given by the interval of
1332 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1333 * with the migration of free compaction scanner. The scanners then need to
1334 * use only pfn_valid_within() check for arches that allow holes within
1337 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1339 * It's possible on some configurations to have a setup like node0 node1 node0
1340 * i.e. it's possible that all pages within a zones range of pages do not
1341 * belong to a single zone. We assume that a border between node0 and node1
1342 * can occur within a single pageblock, but not a node0 node1 node0
1343 * interleaving within a single pageblock. It is therefore sufficient to check
1344 * the first and last page of a pageblock and avoid checking each individual
1345 * page in a pageblock.
1347 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1348 unsigned long end_pfn
, struct zone
*zone
)
1350 struct page
*start_page
;
1351 struct page
*end_page
;
1353 /* end_pfn is one past the range we are checking */
1356 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1359 start_page
= pfn_to_page(start_pfn
);
1361 if (page_zone(start_page
) != zone
)
1364 end_page
= pfn_to_page(end_pfn
);
1366 /* This gives a shorter code than deriving page_zone(end_page) */
1367 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1373 void set_zone_contiguous(struct zone
*zone
)
1375 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1376 unsigned long block_end_pfn
;
1378 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1379 for (; block_start_pfn
< zone_end_pfn(zone
);
1380 block_start_pfn
= block_end_pfn
,
1381 block_end_pfn
+= pageblock_nr_pages
) {
1383 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1385 if (!__pageblock_pfn_to_page(block_start_pfn
,
1386 block_end_pfn
, zone
))
1390 /* We confirm that there is no hole */
1391 zone
->contiguous
= true;
1394 void clear_zone_contiguous(struct zone
*zone
)
1396 zone
->contiguous
= false;
1399 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1400 static void __init
deferred_free_range(struct page
*page
,
1401 unsigned long pfn
, int nr_pages
)
1408 /* Free a large naturally-aligned chunk if possible */
1409 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1410 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1411 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1412 __free_pages_boot_core(page
, MAX_ORDER
-1);
1416 for (i
= 0; i
< nr_pages
; i
++, page
++)
1417 __free_pages_boot_core(page
, 0);
1420 /* Completion tracking for deferred_init_memmap() threads */
1421 static atomic_t pgdat_init_n_undone __initdata
;
1422 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1424 static inline void __init
pgdat_init_report_one_done(void)
1426 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1427 complete(&pgdat_init_all_done_comp
);
1430 /* Initialise remaining memory on a node */
1431 static int __init
deferred_init_memmap(void *data
)
1433 pg_data_t
*pgdat
= data
;
1434 int nid
= pgdat
->node_id
;
1435 struct mminit_pfnnid_cache nid_init_state
= { };
1436 unsigned long start
= jiffies
;
1437 unsigned long nr_pages
= 0;
1438 unsigned long walk_start
, walk_end
;
1441 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1442 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1444 if (first_init_pfn
== ULONG_MAX
) {
1445 pgdat_init_report_one_done();
1449 /* Bind memory initialisation thread to a local node if possible */
1450 if (!cpumask_empty(cpumask
))
1451 set_cpus_allowed_ptr(current
, cpumask
);
1453 /* Sanity check boundaries */
1454 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1455 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1456 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1458 /* Only the highest zone is deferred so find it */
1459 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1460 zone
= pgdat
->node_zones
+ zid
;
1461 if (first_init_pfn
< zone_end_pfn(zone
))
1465 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1466 unsigned long pfn
, end_pfn
;
1467 struct page
*page
= NULL
;
1468 struct page
*free_base_page
= NULL
;
1469 unsigned long free_base_pfn
= 0;
1472 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1473 pfn
= first_init_pfn
;
1474 if (pfn
< walk_start
)
1476 if (pfn
< zone
->zone_start_pfn
)
1477 pfn
= zone
->zone_start_pfn
;
1479 for (; pfn
< end_pfn
; pfn
++) {
1480 if (!pfn_valid_within(pfn
))
1484 * Ensure pfn_valid is checked every
1485 * MAX_ORDER_NR_PAGES for memory holes
1487 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1488 if (!pfn_valid(pfn
)) {
1494 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1499 /* Minimise pfn page lookups and scheduler checks */
1500 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1503 nr_pages
+= nr_to_free
;
1504 deferred_free_range(free_base_page
,
1505 free_base_pfn
, nr_to_free
);
1506 free_base_page
= NULL
;
1507 free_base_pfn
= nr_to_free
= 0;
1509 page
= pfn_to_page(pfn
);
1514 VM_BUG_ON(page_zone(page
) != zone
);
1518 __init_single_page(page
, pfn
, zid
, nid
);
1519 if (!free_base_page
) {
1520 free_base_page
= page
;
1521 free_base_pfn
= pfn
;
1526 /* Where possible, batch up pages for a single free */
1529 /* Free the current block of pages to allocator */
1530 nr_pages
+= nr_to_free
;
1531 deferred_free_range(free_base_page
, free_base_pfn
,
1533 free_base_page
= NULL
;
1534 free_base_pfn
= nr_to_free
= 0;
1537 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1540 /* Sanity check that the next zone really is unpopulated */
1541 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1543 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1544 jiffies_to_msecs(jiffies
- start
));
1546 pgdat_init_report_one_done();
1549 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1551 void __init
page_alloc_init_late(void)
1555 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1558 /* There will be num_node_state(N_MEMORY) threads */
1559 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1560 for_each_node_state(nid
, N_MEMORY
) {
1561 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1564 /* Block until all are initialised */
1565 wait_for_completion(&pgdat_init_all_done_comp
);
1567 /* Reinit limits that are based on free pages after the kernel is up */
1568 files_maxfiles_init();
1571 for_each_populated_zone(zone
)
1572 set_zone_contiguous(zone
);
1576 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1577 void __init
init_cma_reserved_pageblock(struct page
*page
)
1579 unsigned i
= pageblock_nr_pages
;
1580 struct page
*p
= page
;
1583 __ClearPageReserved(p
);
1584 set_page_count(p
, 0);
1587 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1589 if (pageblock_order
>= MAX_ORDER
) {
1590 i
= pageblock_nr_pages
;
1593 set_page_refcounted(p
);
1594 __free_pages(p
, MAX_ORDER
- 1);
1595 p
+= MAX_ORDER_NR_PAGES
;
1596 } while (i
-= MAX_ORDER_NR_PAGES
);
1598 set_page_refcounted(page
);
1599 __free_pages(page
, pageblock_order
);
1602 adjust_managed_page_count(page
, pageblock_nr_pages
);
1607 * The order of subdivision here is critical for the IO subsystem.
1608 * Please do not alter this order without good reasons and regression
1609 * testing. Specifically, as large blocks of memory are subdivided,
1610 * the order in which smaller blocks are delivered depends on the order
1611 * they're subdivided in this function. This is the primary factor
1612 * influencing the order in which pages are delivered to the IO
1613 * subsystem according to empirical testing, and this is also justified
1614 * by considering the behavior of a buddy system containing a single
1615 * large block of memory acted on by a series of small allocations.
1616 * This behavior is a critical factor in sglist merging's success.
1620 static inline void expand(struct zone
*zone
, struct page
*page
,
1621 int low
, int high
, struct free_area
*area
,
1624 unsigned long size
= 1 << high
;
1626 while (high
> low
) {
1630 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1632 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1633 debug_guardpage_enabled() &&
1634 high
< debug_guardpage_minorder()) {
1636 * Mark as guard pages (or page), that will allow to
1637 * merge back to allocator when buddy will be freed.
1638 * Corresponding page table entries will not be touched,
1639 * pages will stay not present in virtual address space
1641 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1644 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1646 set_page_order(&page
[size
], high
);
1650 static void check_new_page_bad(struct page
*page
)
1652 const char *bad_reason
= NULL
;
1653 unsigned long bad_flags
= 0;
1655 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1656 bad_reason
= "nonzero mapcount";
1657 if (unlikely(page
->mapping
!= NULL
))
1658 bad_reason
= "non-NULL mapping";
1659 if (unlikely(page_ref_count(page
) != 0))
1660 bad_reason
= "nonzero _count";
1661 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1662 bad_reason
= "HWPoisoned (hardware-corrupted)";
1663 bad_flags
= __PG_HWPOISON
;
1665 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1666 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1667 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1670 if (unlikely(page
->mem_cgroup
))
1671 bad_reason
= "page still charged to cgroup";
1673 bad_page(page
, bad_reason
, bad_flags
);
1677 * This page is about to be returned from the page allocator
1679 static inline int check_new_page(struct page
*page
)
1681 if (likely(page_expected_state(page
,
1682 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1685 check_new_page_bad(page
);
1689 static inline bool free_pages_prezeroed(bool poisoned
)
1691 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1692 page_poisoning_enabled() && poisoned
;
1695 #ifdef CONFIG_DEBUG_VM
1696 static bool check_pcp_refill(struct page
*page
)
1701 static bool check_new_pcp(struct page
*page
)
1703 return check_new_page(page
);
1706 static bool check_pcp_refill(struct page
*page
)
1708 return check_new_page(page
);
1710 static bool check_new_pcp(struct page
*page
)
1714 #endif /* CONFIG_DEBUG_VM */
1716 static bool check_new_pages(struct page
*page
, unsigned int order
)
1719 for (i
= 0; i
< (1 << order
); i
++) {
1720 struct page
*p
= page
+ i
;
1722 if (unlikely(check_new_page(p
)))
1729 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1730 unsigned int alloc_flags
)
1733 bool poisoned
= true;
1735 for (i
= 0; i
< (1 << order
); i
++) {
1736 struct page
*p
= page
+ i
;
1738 poisoned
&= page_is_poisoned(p
);
1741 set_page_private(page
, 0);
1742 set_page_refcounted(page
);
1744 arch_alloc_page(page
, order
);
1745 kernel_map_pages(page
, 1 << order
, 1);
1746 kernel_poison_pages(page
, 1 << order
, 1);
1747 kasan_alloc_pages(page
, order
);
1749 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1750 for (i
= 0; i
< (1 << order
); i
++)
1751 clear_highpage(page
+ i
);
1753 if (order
&& (gfp_flags
& __GFP_COMP
))
1754 prep_compound_page(page
, order
);
1756 set_page_owner(page
, order
, gfp_flags
);
1759 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1760 * allocate the page. The expectation is that the caller is taking
1761 * steps that will free more memory. The caller should avoid the page
1762 * being used for !PFMEMALLOC purposes.
1764 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1765 set_page_pfmemalloc(page
);
1767 clear_page_pfmemalloc(page
);
1771 * Go through the free lists for the given migratetype and remove
1772 * the smallest available page from the freelists
1775 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1778 unsigned int current_order
;
1779 struct free_area
*area
;
1782 /* Find a page of the appropriate size in the preferred list */
1783 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1784 area
= &(zone
->free_area
[current_order
]);
1785 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1789 list_del(&page
->lru
);
1790 rmv_page_order(page
);
1792 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1793 set_pcppage_migratetype(page
, migratetype
);
1802 * This array describes the order lists are fallen back to when
1803 * the free lists for the desirable migrate type are depleted
1805 static int fallbacks
[MIGRATE_TYPES
][4] = {
1806 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1807 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1808 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1810 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1812 #ifdef CONFIG_MEMORY_ISOLATION
1813 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1818 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1821 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1824 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1825 unsigned int order
) { return NULL
; }
1829 * Move the free pages in a range to the free lists of the requested type.
1830 * Note that start_page and end_pages are not aligned on a pageblock
1831 * boundary. If alignment is required, use move_freepages_block()
1833 int move_freepages(struct zone
*zone
,
1834 struct page
*start_page
, struct page
*end_page
,
1839 int pages_moved
= 0;
1841 #ifndef CONFIG_HOLES_IN_ZONE
1843 * page_zone is not safe to call in this context when
1844 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1845 * anyway as we check zone boundaries in move_freepages_block().
1846 * Remove at a later date when no bug reports exist related to
1847 * grouping pages by mobility
1849 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1852 for (page
= start_page
; page
<= end_page
;) {
1853 /* Make sure we are not inadvertently changing nodes */
1854 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1856 if (!pfn_valid_within(page_to_pfn(page
))) {
1861 if (!PageBuddy(page
)) {
1866 order
= page_order(page
);
1867 list_move(&page
->lru
,
1868 &zone
->free_area
[order
].free_list
[migratetype
]);
1870 pages_moved
+= 1 << order
;
1876 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1879 unsigned long start_pfn
, end_pfn
;
1880 struct page
*start_page
, *end_page
;
1882 start_pfn
= page_to_pfn(page
);
1883 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1884 start_page
= pfn_to_page(start_pfn
);
1885 end_page
= start_page
+ pageblock_nr_pages
- 1;
1886 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1888 /* Do not cross zone boundaries */
1889 if (!zone_spans_pfn(zone
, start_pfn
))
1891 if (!zone_spans_pfn(zone
, end_pfn
))
1894 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1897 static void change_pageblock_range(struct page
*pageblock_page
,
1898 int start_order
, int migratetype
)
1900 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1902 while (nr_pageblocks
--) {
1903 set_pageblock_migratetype(pageblock_page
, migratetype
);
1904 pageblock_page
+= pageblock_nr_pages
;
1909 * When we are falling back to another migratetype during allocation, try to
1910 * steal extra free pages from the same pageblocks to satisfy further
1911 * allocations, instead of polluting multiple pageblocks.
1913 * If we are stealing a relatively large buddy page, it is likely there will
1914 * be more free pages in the pageblock, so try to steal them all. For
1915 * reclaimable and unmovable allocations, we steal regardless of page size,
1916 * as fragmentation caused by those allocations polluting movable pageblocks
1917 * is worse than movable allocations stealing from unmovable and reclaimable
1920 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1923 * Leaving this order check is intended, although there is
1924 * relaxed order check in next check. The reason is that
1925 * we can actually steal whole pageblock if this condition met,
1926 * but, below check doesn't guarantee it and that is just heuristic
1927 * so could be changed anytime.
1929 if (order
>= pageblock_order
)
1932 if (order
>= pageblock_order
/ 2 ||
1933 start_mt
== MIGRATE_RECLAIMABLE
||
1934 start_mt
== MIGRATE_UNMOVABLE
||
1935 page_group_by_mobility_disabled
)
1942 * This function implements actual steal behaviour. If order is large enough,
1943 * we can steal whole pageblock. If not, we first move freepages in this
1944 * pageblock and check whether half of pages are moved or not. If half of
1945 * pages are moved, we can change migratetype of pageblock and permanently
1946 * use it's pages as requested migratetype in the future.
1948 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1951 unsigned int current_order
= page_order(page
);
1954 /* Take ownership for orders >= pageblock_order */
1955 if (current_order
>= pageblock_order
) {
1956 change_pageblock_range(page
, current_order
, start_type
);
1960 pages
= move_freepages_block(zone
, page
, start_type
);
1962 /* Claim the whole block if over half of it is free */
1963 if (pages
>= (1 << (pageblock_order
-1)) ||
1964 page_group_by_mobility_disabled
)
1965 set_pageblock_migratetype(page
, start_type
);
1969 * Check whether there is a suitable fallback freepage with requested order.
1970 * If only_stealable is true, this function returns fallback_mt only if
1971 * we can steal other freepages all together. This would help to reduce
1972 * fragmentation due to mixed migratetype pages in one pageblock.
1974 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1975 int migratetype
, bool only_stealable
, bool *can_steal
)
1980 if (area
->nr_free
== 0)
1985 fallback_mt
= fallbacks
[migratetype
][i
];
1986 if (fallback_mt
== MIGRATE_TYPES
)
1989 if (list_empty(&area
->free_list
[fallback_mt
]))
1992 if (can_steal_fallback(order
, migratetype
))
1995 if (!only_stealable
)
2006 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2007 * there are no empty page blocks that contain a page with a suitable order
2009 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2010 unsigned int alloc_order
)
2013 unsigned long max_managed
, flags
;
2016 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2017 * Check is race-prone but harmless.
2019 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2020 if (zone
->nr_reserved_highatomic
>= max_managed
)
2023 spin_lock_irqsave(&zone
->lock
, flags
);
2025 /* Recheck the nr_reserved_highatomic limit under the lock */
2026 if (zone
->nr_reserved_highatomic
>= max_managed
)
2030 mt
= get_pageblock_migratetype(page
);
2031 if (mt
!= MIGRATE_HIGHATOMIC
&&
2032 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
2033 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2034 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2035 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
2039 spin_unlock_irqrestore(&zone
->lock
, flags
);
2043 * Used when an allocation is about to fail under memory pressure. This
2044 * potentially hurts the reliability of high-order allocations when under
2045 * intense memory pressure but failed atomic allocations should be easier
2046 * to recover from than an OOM.
2048 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
2050 struct zonelist
*zonelist
= ac
->zonelist
;
2051 unsigned long flags
;
2057 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2059 /* Preserve at least one pageblock */
2060 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
2063 spin_lock_irqsave(&zone
->lock
, flags
);
2064 for (order
= 0; order
< MAX_ORDER
; order
++) {
2065 struct free_area
*area
= &(zone
->free_area
[order
]);
2067 page
= list_first_entry_or_null(
2068 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2074 * It should never happen but changes to locking could
2075 * inadvertently allow a per-cpu drain to add pages
2076 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2077 * and watch for underflows.
2079 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
2080 zone
->nr_reserved_highatomic
);
2083 * Convert to ac->migratetype and avoid the normal
2084 * pageblock stealing heuristics. Minimally, the caller
2085 * is doing the work and needs the pages. More
2086 * importantly, if the block was always converted to
2087 * MIGRATE_UNMOVABLE or another type then the number
2088 * of pageblocks that cannot be completely freed
2091 set_pageblock_migratetype(page
, ac
->migratetype
);
2092 move_freepages_block(zone
, page
, ac
->migratetype
);
2093 spin_unlock_irqrestore(&zone
->lock
, flags
);
2096 spin_unlock_irqrestore(&zone
->lock
, flags
);
2100 /* Remove an element from the buddy allocator from the fallback list */
2101 static inline struct page
*
2102 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
2104 struct free_area
*area
;
2105 unsigned int current_order
;
2110 /* Find the largest possible block of pages in the other list */
2111 for (current_order
= MAX_ORDER
-1;
2112 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
2114 area
= &(zone
->free_area
[current_order
]);
2115 fallback_mt
= find_suitable_fallback(area
, current_order
,
2116 start_migratetype
, false, &can_steal
);
2117 if (fallback_mt
== -1)
2120 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2123 steal_suitable_fallback(zone
, page
, start_migratetype
);
2125 /* Remove the page from the freelists */
2127 list_del(&page
->lru
);
2128 rmv_page_order(page
);
2130 expand(zone
, page
, order
, current_order
, area
,
2133 * The pcppage_migratetype may differ from pageblock's
2134 * migratetype depending on the decisions in
2135 * find_suitable_fallback(). This is OK as long as it does not
2136 * differ for MIGRATE_CMA pageblocks. Those can be used as
2137 * fallback only via special __rmqueue_cma_fallback() function
2139 set_pcppage_migratetype(page
, start_migratetype
);
2141 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2142 start_migratetype
, fallback_mt
);
2151 * Do the hard work of removing an element from the buddy allocator.
2152 * Call me with the zone->lock already held.
2154 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2159 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2160 if (unlikely(!page
)) {
2161 if (migratetype
== MIGRATE_MOVABLE
)
2162 page
= __rmqueue_cma_fallback(zone
, order
);
2165 page
= __rmqueue_fallback(zone
, order
, migratetype
);
2168 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2173 * Obtain a specified number of elements from the buddy allocator, all under
2174 * a single hold of the lock, for efficiency. Add them to the supplied list.
2175 * Returns the number of new pages which were placed at *list.
2177 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2178 unsigned long count
, struct list_head
*list
,
2179 int migratetype
, bool cold
)
2183 spin_lock(&zone
->lock
);
2184 for (i
= 0; i
< count
; ++i
) {
2185 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2186 if (unlikely(page
== NULL
))
2189 if (unlikely(check_pcp_refill(page
)))
2193 * Split buddy pages returned by expand() are received here
2194 * in physical page order. The page is added to the callers and
2195 * list and the list head then moves forward. From the callers
2196 * perspective, the linked list is ordered by page number in
2197 * some conditions. This is useful for IO devices that can
2198 * merge IO requests if the physical pages are ordered
2202 list_add(&page
->lru
, list
);
2204 list_add_tail(&page
->lru
, list
);
2206 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2207 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2210 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2211 spin_unlock(&zone
->lock
);
2217 * Called from the vmstat counter updater to drain pagesets of this
2218 * currently executing processor on remote nodes after they have
2221 * Note that this function must be called with the thread pinned to
2222 * a single processor.
2224 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2226 unsigned long flags
;
2227 int to_drain
, batch
;
2229 local_irq_save(flags
);
2230 batch
= READ_ONCE(pcp
->batch
);
2231 to_drain
= min(pcp
->count
, batch
);
2233 free_pcppages_bulk(zone
, to_drain
, pcp
);
2234 pcp
->count
-= to_drain
;
2236 local_irq_restore(flags
);
2241 * Drain pcplists of the indicated processor and zone.
2243 * The processor must either be the current processor and the
2244 * thread pinned to the current processor or a processor that
2247 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2249 unsigned long flags
;
2250 struct per_cpu_pageset
*pset
;
2251 struct per_cpu_pages
*pcp
;
2253 local_irq_save(flags
);
2254 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2258 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2261 local_irq_restore(flags
);
2265 * Drain pcplists of all zones on the indicated processor.
2267 * The processor must either be the current processor and the
2268 * thread pinned to the current processor or a processor that
2271 static void drain_pages(unsigned int cpu
)
2275 for_each_populated_zone(zone
) {
2276 drain_pages_zone(cpu
, zone
);
2281 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2283 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2284 * the single zone's pages.
2286 void drain_local_pages(struct zone
*zone
)
2288 int cpu
= smp_processor_id();
2291 drain_pages_zone(cpu
, zone
);
2297 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2299 * When zone parameter is non-NULL, spill just the single zone's pages.
2301 * Note that this code is protected against sending an IPI to an offline
2302 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2303 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2304 * nothing keeps CPUs from showing up after we populated the cpumask and
2305 * before the call to on_each_cpu_mask().
2307 void drain_all_pages(struct zone
*zone
)
2312 * Allocate in the BSS so we wont require allocation in
2313 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2315 static cpumask_t cpus_with_pcps
;
2318 * We don't care about racing with CPU hotplug event
2319 * as offline notification will cause the notified
2320 * cpu to drain that CPU pcps and on_each_cpu_mask
2321 * disables preemption as part of its processing
2323 for_each_online_cpu(cpu
) {
2324 struct per_cpu_pageset
*pcp
;
2326 bool has_pcps
= false;
2329 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2333 for_each_populated_zone(z
) {
2334 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2335 if (pcp
->pcp
.count
) {
2343 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2345 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2347 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2351 #ifdef CONFIG_HIBERNATION
2353 void mark_free_pages(struct zone
*zone
)
2355 unsigned long pfn
, max_zone_pfn
;
2356 unsigned long flags
;
2357 unsigned int order
, t
;
2360 if (zone_is_empty(zone
))
2363 spin_lock_irqsave(&zone
->lock
, flags
);
2365 max_zone_pfn
= zone_end_pfn(zone
);
2366 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2367 if (pfn_valid(pfn
)) {
2368 page
= pfn_to_page(pfn
);
2370 if (page_zone(page
) != zone
)
2373 if (!swsusp_page_is_forbidden(page
))
2374 swsusp_unset_page_free(page
);
2377 for_each_migratetype_order(order
, t
) {
2378 list_for_each_entry(page
,
2379 &zone
->free_area
[order
].free_list
[t
], lru
) {
2382 pfn
= page_to_pfn(page
);
2383 for (i
= 0; i
< (1UL << order
); i
++)
2384 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2387 spin_unlock_irqrestore(&zone
->lock
, flags
);
2389 #endif /* CONFIG_PM */
2392 * Free a 0-order page
2393 * cold == true ? free a cold page : free a hot page
2395 void free_hot_cold_page(struct page
*page
, bool cold
)
2397 struct zone
*zone
= page_zone(page
);
2398 struct per_cpu_pages
*pcp
;
2399 unsigned long flags
;
2400 unsigned long pfn
= page_to_pfn(page
);
2403 if (!free_pcp_prepare(page
))
2406 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2407 set_pcppage_migratetype(page
, migratetype
);
2408 local_irq_save(flags
);
2409 __count_vm_event(PGFREE
);
2412 * We only track unmovable, reclaimable and movable on pcp lists.
2413 * Free ISOLATE pages back to the allocator because they are being
2414 * offlined but treat RESERVE as movable pages so we can get those
2415 * areas back if necessary. Otherwise, we may have to free
2416 * excessively into the page allocator
2418 if (migratetype
>= MIGRATE_PCPTYPES
) {
2419 if (unlikely(is_migrate_isolate(migratetype
))) {
2420 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2423 migratetype
= MIGRATE_MOVABLE
;
2426 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2428 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2430 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2432 if (pcp
->count
>= pcp
->high
) {
2433 unsigned long batch
= READ_ONCE(pcp
->batch
);
2434 free_pcppages_bulk(zone
, batch
, pcp
);
2435 pcp
->count
-= batch
;
2439 local_irq_restore(flags
);
2443 * Free a list of 0-order pages
2445 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2447 struct page
*page
, *next
;
2449 list_for_each_entry_safe(page
, next
, list
, lru
) {
2450 trace_mm_page_free_batched(page
, cold
);
2451 free_hot_cold_page(page
, cold
);
2456 * split_page takes a non-compound higher-order page, and splits it into
2457 * n (1<<order) sub-pages: page[0..n]
2458 * Each sub-page must be freed individually.
2460 * Note: this is probably too low level an operation for use in drivers.
2461 * Please consult with lkml before using this in your driver.
2463 void split_page(struct page
*page
, unsigned int order
)
2468 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2469 VM_BUG_ON_PAGE(!page_count(page
), page
);
2471 #ifdef CONFIG_KMEMCHECK
2473 * Split shadow pages too, because free(page[0]) would
2474 * otherwise free the whole shadow.
2476 if (kmemcheck_page_is_tracked(page
))
2477 split_page(virt_to_page(page
[0].shadow
), order
);
2480 gfp_mask
= get_page_owner_gfp(page
);
2481 set_page_owner(page
, 0, gfp_mask
);
2482 for (i
= 1; i
< (1 << order
); i
++) {
2483 set_page_refcounted(page
+ i
);
2484 set_page_owner(page
+ i
, 0, gfp_mask
);
2487 EXPORT_SYMBOL_GPL(split_page
);
2489 int __isolate_free_page(struct page
*page
, unsigned int order
)
2491 unsigned long watermark
;
2495 BUG_ON(!PageBuddy(page
));
2497 zone
= page_zone(page
);
2498 mt
= get_pageblock_migratetype(page
);
2500 if (!is_migrate_isolate(mt
)) {
2501 /* Obey watermarks as if the page was being allocated */
2502 watermark
= low_wmark_pages(zone
) + (1 << order
);
2503 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2506 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2509 /* Remove page from free list */
2510 list_del(&page
->lru
);
2511 zone
->free_area
[order
].nr_free
--;
2512 rmv_page_order(page
);
2514 set_page_owner(page
, order
, __GFP_MOVABLE
);
2516 /* Set the pageblock if the isolated page is at least a pageblock */
2517 if (order
>= pageblock_order
- 1) {
2518 struct page
*endpage
= page
+ (1 << order
) - 1;
2519 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2520 int mt
= get_pageblock_migratetype(page
);
2521 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2522 set_pageblock_migratetype(page
,
2528 return 1UL << order
;
2532 * Similar to split_page except the page is already free. As this is only
2533 * being used for migration, the migratetype of the block also changes.
2534 * As this is called with interrupts disabled, the caller is responsible
2535 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2538 * Note: this is probably too low level an operation for use in drivers.
2539 * Please consult with lkml before using this in your driver.
2541 int split_free_page(struct page
*page
)
2546 order
= page_order(page
);
2548 nr_pages
= __isolate_free_page(page
, order
);
2552 /* Split into individual pages */
2553 set_page_refcounted(page
);
2554 split_page(page
, order
);
2559 * Update NUMA hit/miss statistics
2561 * Must be called with interrupts disabled.
2563 * When __GFP_OTHER_NODE is set assume the node of the preferred
2564 * zone is the local node. This is useful for daemons who allocate
2565 * memory on behalf of other processes.
2567 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
,
2571 int local_nid
= numa_node_id();
2572 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2574 if (unlikely(flags
& __GFP_OTHER_NODE
)) {
2575 local_stat
= NUMA_OTHER
;
2576 local_nid
= preferred_zone
->node
;
2579 if (z
->node
== local_nid
) {
2580 __inc_zone_state(z
, NUMA_HIT
);
2581 __inc_zone_state(z
, local_stat
);
2583 __inc_zone_state(z
, NUMA_MISS
);
2584 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2590 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2593 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2594 struct zone
*zone
, unsigned int order
,
2595 gfp_t gfp_flags
, unsigned int alloc_flags
,
2598 unsigned long flags
;
2600 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2602 if (likely(order
== 0)) {
2603 struct per_cpu_pages
*pcp
;
2604 struct list_head
*list
;
2606 local_irq_save(flags
);
2608 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2609 list
= &pcp
->lists
[migratetype
];
2610 if (list_empty(list
)) {
2611 pcp
->count
+= rmqueue_bulk(zone
, 0,
2614 if (unlikely(list_empty(list
)))
2619 page
= list_last_entry(list
, struct page
, lru
);
2621 page
= list_first_entry(list
, struct page
, lru
);
2622 } while (page
&& check_new_pcp(page
));
2624 __dec_zone_state(zone
, NR_ALLOC_BATCH
);
2625 list_del(&page
->lru
);
2629 * We most definitely don't want callers attempting to
2630 * allocate greater than order-1 page units with __GFP_NOFAIL.
2632 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2633 spin_lock_irqsave(&zone
->lock
, flags
);
2637 if (alloc_flags
& ALLOC_HARDER
) {
2638 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2640 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2643 page
= __rmqueue(zone
, order
, migratetype
);
2644 } while (page
&& check_new_pages(page
, order
));
2645 spin_unlock(&zone
->lock
);
2648 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2649 __mod_zone_freepage_state(zone
, -(1 << order
),
2650 get_pcppage_migratetype(page
));
2653 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2654 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2655 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2657 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2658 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2659 local_irq_restore(flags
);
2661 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2665 local_irq_restore(flags
);
2669 #ifdef CONFIG_FAIL_PAGE_ALLOC
2672 struct fault_attr attr
;
2674 bool ignore_gfp_highmem
;
2675 bool ignore_gfp_reclaim
;
2677 } fail_page_alloc
= {
2678 .attr
= FAULT_ATTR_INITIALIZER
,
2679 .ignore_gfp_reclaim
= true,
2680 .ignore_gfp_highmem
= true,
2684 static int __init
setup_fail_page_alloc(char *str
)
2686 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2688 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2690 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2692 if (order
< fail_page_alloc
.min_order
)
2694 if (gfp_mask
& __GFP_NOFAIL
)
2696 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2698 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2699 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2702 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2705 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2707 static int __init
fail_page_alloc_debugfs(void)
2709 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2712 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2713 &fail_page_alloc
.attr
);
2715 return PTR_ERR(dir
);
2717 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2718 &fail_page_alloc
.ignore_gfp_reclaim
))
2720 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2721 &fail_page_alloc
.ignore_gfp_highmem
))
2723 if (!debugfs_create_u32("min-order", mode
, dir
,
2724 &fail_page_alloc
.min_order
))
2729 debugfs_remove_recursive(dir
);
2734 late_initcall(fail_page_alloc_debugfs
);
2736 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2738 #else /* CONFIG_FAIL_PAGE_ALLOC */
2740 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2745 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2748 * Return true if free base pages are above 'mark'. For high-order checks it
2749 * will return true of the order-0 watermark is reached and there is at least
2750 * one free page of a suitable size. Checking now avoids taking the zone lock
2751 * to check in the allocation paths if no pages are free.
2753 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2754 int classzone_idx
, unsigned int alloc_flags
,
2759 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2761 /* free_pages may go negative - that's OK */
2762 free_pages
-= (1 << order
) - 1;
2764 if (alloc_flags
& ALLOC_HIGH
)
2768 * If the caller does not have rights to ALLOC_HARDER then subtract
2769 * the high-atomic reserves. This will over-estimate the size of the
2770 * atomic reserve but it avoids a search.
2772 if (likely(!alloc_harder
))
2773 free_pages
-= z
->nr_reserved_highatomic
;
2778 /* If allocation can't use CMA areas don't use free CMA pages */
2779 if (!(alloc_flags
& ALLOC_CMA
))
2780 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2784 * Check watermarks for an order-0 allocation request. If these
2785 * are not met, then a high-order request also cannot go ahead
2786 * even if a suitable page happened to be free.
2788 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2791 /* If this is an order-0 request then the watermark is fine */
2795 /* For a high-order request, check at least one suitable page is free */
2796 for (o
= order
; o
< MAX_ORDER
; o
++) {
2797 struct free_area
*area
= &z
->free_area
[o
];
2806 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2807 if (!list_empty(&area
->free_list
[mt
]))
2812 if ((alloc_flags
& ALLOC_CMA
) &&
2813 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2821 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2822 int classzone_idx
, unsigned int alloc_flags
)
2824 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2825 zone_page_state(z
, NR_FREE_PAGES
));
2828 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
2829 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
2831 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2835 /* If allocation can't use CMA areas don't use free CMA pages */
2836 if (!(alloc_flags
& ALLOC_CMA
))
2837 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2841 * Fast check for order-0 only. If this fails then the reserves
2842 * need to be calculated. There is a corner case where the check
2843 * passes but only the high-order atomic reserve are free. If
2844 * the caller is !atomic then it'll uselessly search the free
2845 * list. That corner case is then slower but it is harmless.
2847 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
2850 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2854 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2855 unsigned long mark
, int classzone_idx
)
2857 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2859 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2860 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2862 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2867 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2869 return local_zone
->node
== zone
->node
;
2872 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2874 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2877 #else /* CONFIG_NUMA */
2878 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2883 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2887 #endif /* CONFIG_NUMA */
2889 static void reset_alloc_batches(struct zone
*preferred_zone
)
2891 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2894 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2895 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2896 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2897 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2898 } while (zone
++ != preferred_zone
);
2902 * get_page_from_freelist goes through the zonelist trying to allocate
2905 static struct page
*
2906 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2907 const struct alloc_context
*ac
)
2909 struct zoneref
*z
= ac
->preferred_zoneref
;
2911 bool fair_skipped
= false;
2912 bool apply_fair
= (alloc_flags
& ALLOC_FAIR
);
2916 * Scan zonelist, looking for a zone with enough free.
2917 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2919 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
2924 if (cpusets_enabled() &&
2925 (alloc_flags
& ALLOC_CPUSET
) &&
2926 !__cpuset_zone_allowed(zone
, gfp_mask
))
2929 * Distribute pages in proportion to the individual
2930 * zone size to ensure fair page aging. The zone a
2931 * page was allocated in should have no effect on the
2932 * time the page has in memory before being reclaimed.
2935 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2936 fair_skipped
= true;
2939 if (!zone_local(ac
->preferred_zoneref
->zone
, zone
)) {
2946 * When allocating a page cache page for writing, we
2947 * want to get it from a zone that is within its dirty
2948 * limit, such that no single zone holds more than its
2949 * proportional share of globally allowed dirty pages.
2950 * The dirty limits take into account the zone's
2951 * lowmem reserves and high watermark so that kswapd
2952 * should be able to balance it without having to
2953 * write pages from its LRU list.
2955 * This may look like it could increase pressure on
2956 * lower zones by failing allocations in higher zones
2957 * before they are full. But the pages that do spill
2958 * over are limited as the lower zones are protected
2959 * by this very same mechanism. It should not become
2960 * a practical burden to them.
2962 * XXX: For now, allow allocations to potentially
2963 * exceed the per-zone dirty limit in the slowpath
2964 * (spread_dirty_pages unset) before going into reclaim,
2965 * which is important when on a NUMA setup the allowed
2966 * zones are together not big enough to reach the
2967 * global limit. The proper fix for these situations
2968 * will require awareness of zones in the
2969 * dirty-throttling and the flusher threads.
2971 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2974 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2975 if (!zone_watermark_fast(zone
, order
, mark
,
2976 ac_classzone_idx(ac
), alloc_flags
)) {
2979 /* Checked here to keep the fast path fast */
2980 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2981 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2984 if (zone_reclaim_mode
== 0 ||
2985 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
2988 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2990 case ZONE_RECLAIM_NOSCAN
:
2993 case ZONE_RECLAIM_FULL
:
2994 /* scanned but unreclaimable */
2997 /* did we reclaim enough */
2998 if (zone_watermark_ok(zone
, order
, mark
,
2999 ac_classzone_idx(ac
), alloc_flags
))
3007 page
= buffered_rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3008 gfp_mask
, alloc_flags
, ac
->migratetype
);
3010 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3013 * If this is a high-order atomic allocation then check
3014 * if the pageblock should be reserved for the future
3016 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3017 reserve_highatomic_pageblock(page
, zone
, order
);
3024 * The first pass makes sure allocations are spread fairly within the
3025 * local node. However, the local node might have free pages left
3026 * after the fairness batches are exhausted, and remote zones haven't
3027 * even been considered yet. Try once more without fairness, and
3028 * include remote zones now, before entering the slowpath and waking
3029 * kswapd: prefer spilling to a remote zone over swapping locally.
3034 fair_skipped
= false;
3035 reset_alloc_batches(ac
->preferred_zoneref
->zone
);
3043 * Large machines with many possible nodes should not always dump per-node
3044 * meminfo in irq context.
3046 static inline bool should_suppress_show_mem(void)
3051 ret
= in_interrupt();
3056 static DEFINE_RATELIMIT_STATE(nopage_rs
,
3057 DEFAULT_RATELIMIT_INTERVAL
,
3058 DEFAULT_RATELIMIT_BURST
);
3060 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
3062 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3064 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
3065 debug_guardpage_minorder() > 0)
3069 * This documents exceptions given to allocations in certain
3070 * contexts that are allowed to allocate outside current's set
3073 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3074 if (test_thread_flag(TIF_MEMDIE
) ||
3075 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3076 filter
&= ~SHOW_MEM_FILTER_NODES
;
3077 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3078 filter
&= ~SHOW_MEM_FILTER_NODES
;
3081 struct va_format vaf
;
3084 va_start(args
, fmt
);
3089 pr_warn("%pV", &vaf
);
3094 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3095 current
->comm
, order
, gfp_mask
, &gfp_mask
);
3097 if (!should_suppress_show_mem())
3101 static inline struct page
*
3102 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3103 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3105 struct oom_control oc
= {
3106 .zonelist
= ac
->zonelist
,
3107 .nodemask
= ac
->nodemask
,
3108 .gfp_mask
= gfp_mask
,
3113 *did_some_progress
= 0;
3116 * Acquire the oom lock. If that fails, somebody else is
3117 * making progress for us.
3119 if (!mutex_trylock(&oom_lock
)) {
3120 *did_some_progress
= 1;
3121 schedule_timeout_uninterruptible(1);
3126 * Go through the zonelist yet one more time, keep very high watermark
3127 * here, this is only to catch a parallel oom killing, we must fail if
3128 * we're still under heavy pressure.
3130 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3131 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3135 if (!(gfp_mask
& __GFP_NOFAIL
)) {
3136 /* Coredumps can quickly deplete all memory reserves */
3137 if (current
->flags
& PF_DUMPCORE
)
3139 /* The OOM killer will not help higher order allocs */
3140 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3142 /* The OOM killer does not needlessly kill tasks for lowmem */
3143 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3145 if (pm_suspended_storage())
3148 * XXX: GFP_NOFS allocations should rather fail than rely on
3149 * other request to make a forward progress.
3150 * We are in an unfortunate situation where out_of_memory cannot
3151 * do much for this context but let's try it to at least get
3152 * access to memory reserved if the current task is killed (see
3153 * out_of_memory). Once filesystems are ready to handle allocation
3154 * failures more gracefully we should just bail out here.
3157 /* The OOM killer may not free memory on a specific node */
3158 if (gfp_mask
& __GFP_THISNODE
)
3161 /* Exhausted what can be done so it's blamo time */
3162 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3163 *did_some_progress
= 1;
3165 if (gfp_mask
& __GFP_NOFAIL
) {
3166 page
= get_page_from_freelist(gfp_mask
, order
,
3167 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
3169 * fallback to ignore cpuset restriction if our nodes
3173 page
= get_page_from_freelist(gfp_mask
, order
,
3174 ALLOC_NO_WATERMARKS
, ac
);
3178 mutex_unlock(&oom_lock
);
3184 * Maximum number of compaction retries wit a progress before OOM
3185 * killer is consider as the only way to move forward.
3187 #define MAX_COMPACT_RETRIES 16
3189 #ifdef CONFIG_COMPACTION
3190 /* Try memory compaction for high-order allocations before reclaim */
3191 static struct page
*
3192 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3193 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3194 enum migrate_mode mode
, enum compact_result
*compact_result
)
3197 int contended_compaction
;
3202 current
->flags
|= PF_MEMALLOC
;
3203 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3204 mode
, &contended_compaction
);
3205 current
->flags
&= ~PF_MEMALLOC
;
3207 if (*compact_result
<= COMPACT_INACTIVE
)
3211 * At least in one zone compaction wasn't deferred or skipped, so let's
3212 * count a compaction stall
3214 count_vm_event(COMPACTSTALL
);
3216 page
= get_page_from_freelist(gfp_mask
, order
,
3217 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3220 struct zone
*zone
= page_zone(page
);
3222 zone
->compact_blockskip_flush
= false;
3223 compaction_defer_reset(zone
, order
, true);
3224 count_vm_event(COMPACTSUCCESS
);
3229 * It's bad if compaction run occurs and fails. The most likely reason
3230 * is that pages exist, but not enough to satisfy watermarks.
3232 count_vm_event(COMPACTFAIL
);
3235 * In all zones where compaction was attempted (and not
3236 * deferred or skipped), lock contention has been detected.
3237 * For THP allocation we do not want to disrupt the others
3238 * so we fallback to base pages instead.
3240 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3241 *compact_result
= COMPACT_CONTENDED
;
3244 * If compaction was aborted due to need_resched(), we do not
3245 * want to further increase allocation latency, unless it is
3246 * khugepaged trying to collapse.
3248 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3249 && !(current
->flags
& PF_KTHREAD
))
3250 *compact_result
= COMPACT_CONTENDED
;
3258 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3259 enum compact_result compact_result
, enum migrate_mode
*migrate_mode
,
3260 int compaction_retries
)
3262 int max_retries
= MAX_COMPACT_RETRIES
;
3268 * compaction considers all the zone as desperately out of memory
3269 * so it doesn't really make much sense to retry except when the
3270 * failure could be caused by weak migration mode.
3272 if (compaction_failed(compact_result
)) {
3273 if (*migrate_mode
== MIGRATE_ASYNC
) {
3274 *migrate_mode
= MIGRATE_SYNC_LIGHT
;
3281 * make sure the compaction wasn't deferred or didn't bail out early
3282 * due to locks contention before we declare that we should give up.
3283 * But do not retry if the given zonelist is not suitable for
3286 if (compaction_withdrawn(compact_result
))
3287 return compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3290 * !costly requests are much more important than __GFP_REPEAT
3291 * costly ones because they are de facto nofail and invoke OOM
3292 * killer to move on while costly can fail and users are ready
3293 * to cope with that. 1/4 retries is rather arbitrary but we
3294 * would need much more detailed feedback from compaction to
3295 * make a better decision.
3297 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3299 if (compaction_retries
<= max_retries
)
3305 static inline struct page
*
3306 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3307 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3308 enum migrate_mode mode
, enum compact_result
*compact_result
)
3310 *compact_result
= COMPACT_SKIPPED
;
3315 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3316 enum compact_result compact_result
,
3317 enum migrate_mode
*migrate_mode
,
3318 int compaction_retries
)
3322 #endif /* CONFIG_COMPACTION */
3324 /* Perform direct synchronous page reclaim */
3326 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3327 const struct alloc_context
*ac
)
3329 struct reclaim_state reclaim_state
;
3334 /* We now go into synchronous reclaim */
3335 cpuset_memory_pressure_bump();
3336 current
->flags
|= PF_MEMALLOC
;
3337 lockdep_set_current_reclaim_state(gfp_mask
);
3338 reclaim_state
.reclaimed_slab
= 0;
3339 current
->reclaim_state
= &reclaim_state
;
3341 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3344 current
->reclaim_state
= NULL
;
3345 lockdep_clear_current_reclaim_state();
3346 current
->flags
&= ~PF_MEMALLOC
;
3353 /* The really slow allocator path where we enter direct reclaim */
3354 static inline struct page
*
3355 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3356 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3357 unsigned long *did_some_progress
)
3359 struct page
*page
= NULL
;
3360 bool drained
= false;
3362 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3363 if (unlikely(!(*did_some_progress
)))
3367 page
= get_page_from_freelist(gfp_mask
, order
,
3368 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3371 * If an allocation failed after direct reclaim, it could be because
3372 * pages are pinned on the per-cpu lists or in high alloc reserves.
3373 * Shrink them them and try again
3375 if (!page
&& !drained
) {
3376 unreserve_highatomic_pageblock(ac
);
3377 drain_all_pages(NULL
);
3385 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3390 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3391 ac
->high_zoneidx
, ac
->nodemask
)
3392 wakeup_kswapd(zone
, order
, ac_classzone_idx(ac
));
3395 static inline unsigned int
3396 gfp_to_alloc_flags(gfp_t gfp_mask
)
3398 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3400 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3401 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3404 * The caller may dip into page reserves a bit more if the caller
3405 * cannot run direct reclaim, or if the caller has realtime scheduling
3406 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3407 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3409 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3411 if (gfp_mask
& __GFP_ATOMIC
) {
3413 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3414 * if it can't schedule.
3416 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3417 alloc_flags
|= ALLOC_HARDER
;
3419 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3420 * comment for __cpuset_node_allowed().
3422 alloc_flags
&= ~ALLOC_CPUSET
;
3423 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3424 alloc_flags
|= ALLOC_HARDER
;
3426 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3427 if (gfp_mask
& __GFP_MEMALLOC
)
3428 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3429 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3430 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3431 else if (!in_interrupt() &&
3432 ((current
->flags
& PF_MEMALLOC
) ||
3433 unlikely(test_thread_flag(TIF_MEMDIE
))))
3434 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3437 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3438 alloc_flags
|= ALLOC_CMA
;
3443 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3445 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3448 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3450 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3454 * Maximum number of reclaim retries without any progress before OOM killer
3455 * is consider as the only way to move forward.
3457 #define MAX_RECLAIM_RETRIES 16
3460 * Checks whether it makes sense to retry the reclaim to make a forward progress
3461 * for the given allocation request.
3462 * The reclaim feedback represented by did_some_progress (any progress during
3463 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3464 * any progress in a row) is considered as well as the reclaimable pages on the
3465 * applicable zone list (with a backoff mechanism which is a function of
3466 * no_progress_loops).
3468 * Returns true if a retry is viable or false to enter the oom path.
3471 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3472 struct alloc_context
*ac
, int alloc_flags
,
3473 bool did_some_progress
, int no_progress_loops
)
3479 * Make sure we converge to OOM if we cannot make any progress
3480 * several times in the row.
3482 if (no_progress_loops
> MAX_RECLAIM_RETRIES
)
3486 * Keep reclaiming pages while there is a chance this will lead somewhere.
3487 * If none of the target zones can satisfy our allocation request even
3488 * if all reclaimable pages are considered then we are screwed and have
3491 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3493 unsigned long available
;
3494 unsigned long reclaimable
;
3496 available
= reclaimable
= zone_reclaimable_pages(zone
);
3497 available
-= DIV_ROUND_UP(no_progress_loops
* available
,
3498 MAX_RECLAIM_RETRIES
);
3499 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3502 * Would the allocation succeed if we reclaimed the whole
3505 if (__zone_watermark_ok(zone
, order
, min_wmark_pages(zone
),
3506 ac_classzone_idx(ac
), alloc_flags
, available
)) {
3508 * If we didn't make any progress and have a lot of
3509 * dirty + writeback pages then we should wait for
3510 * an IO to complete to slow down the reclaim and
3511 * prevent from pre mature OOM
3513 if (!did_some_progress
) {
3514 unsigned long writeback
;
3515 unsigned long dirty
;
3517 writeback
= zone_page_state_snapshot(zone
,
3519 dirty
= zone_page_state_snapshot(zone
, NR_FILE_DIRTY
);
3521 if (2*(writeback
+ dirty
) > reclaimable
) {
3522 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3528 * Memory allocation/reclaim might be called from a WQ
3529 * context and the current implementation of the WQ
3530 * concurrency control doesn't recognize that
3531 * a particular WQ is congested if the worker thread is
3532 * looping without ever sleeping. Therefore we have to
3533 * do a short sleep here rather than calling
3536 if (current
->flags
& PF_WQ_WORKER
)
3537 schedule_timeout_uninterruptible(1);
3548 static inline struct page
*
3549 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3550 struct alloc_context
*ac
)
3552 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3553 struct page
*page
= NULL
;
3554 unsigned int alloc_flags
;
3555 unsigned long did_some_progress
;
3556 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3557 enum compact_result compact_result
;
3558 int compaction_retries
= 0;
3559 int no_progress_loops
= 0;
3562 * In the slowpath, we sanity check order to avoid ever trying to
3563 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3564 * be using allocators in order of preference for an area that is
3567 if (order
>= MAX_ORDER
) {
3568 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3573 * We also sanity check to catch abuse of atomic reserves being used by
3574 * callers that are not in atomic context.
3576 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3577 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3578 gfp_mask
&= ~__GFP_ATOMIC
;
3581 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3582 wake_all_kswapds(order
, ac
);
3585 * OK, we're below the kswapd watermark and have kicked background
3586 * reclaim. Now things get more complex, so set up alloc_flags according
3587 * to how we want to proceed.
3589 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3591 /* This is the last chance, in general, before the goto nopage. */
3592 page
= get_page_from_freelist(gfp_mask
, order
,
3593 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3597 /* Allocate without watermarks if the context allows */
3598 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3600 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3601 * the allocation is high priority and these type of
3602 * allocations are system rather than user orientated
3604 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3605 page
= get_page_from_freelist(gfp_mask
, order
,
3606 ALLOC_NO_WATERMARKS
, ac
);
3611 /* Caller is not willing to reclaim, we can't balance anything */
3612 if (!can_direct_reclaim
) {
3614 * All existing users of the __GFP_NOFAIL are blockable, so warn
3615 * of any new users that actually allow this type of allocation
3618 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3622 /* Avoid recursion of direct reclaim */
3623 if (current
->flags
& PF_MEMALLOC
) {
3625 * __GFP_NOFAIL request from this context is rather bizarre
3626 * because we cannot reclaim anything and only can loop waiting
3627 * for somebody to do a work for us.
3629 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3636 /* Avoid allocations with no watermarks from looping endlessly */
3637 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3641 * Try direct compaction. The first pass is asynchronous. Subsequent
3642 * attempts after direct reclaim are synchronous
3644 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3650 /* Checks for THP-specific high-order allocations */
3651 if (is_thp_gfp_mask(gfp_mask
)) {
3653 * If compaction is deferred for high-order allocations, it is
3654 * because sync compaction recently failed. If this is the case
3655 * and the caller requested a THP allocation, we do not want
3656 * to heavily disrupt the system, so we fail the allocation
3657 * instead of entering direct reclaim.
3659 if (compact_result
== COMPACT_DEFERRED
)
3663 * Compaction is contended so rather back off than cause
3666 if(compact_result
== COMPACT_CONTENDED
)
3670 if (order
&& compaction_made_progress(compact_result
))
3671 compaction_retries
++;
3673 /* Try direct reclaim and then allocating */
3674 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3675 &did_some_progress
);
3679 /* Do not loop if specifically requested */
3680 if (gfp_mask
& __GFP_NORETRY
)
3684 * Do not retry costly high order allocations unless they are
3687 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_REPEAT
))
3691 * Costly allocations might have made a progress but this doesn't mean
3692 * their order will become available due to high fragmentation so
3693 * always increment the no progress counter for them
3695 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3696 no_progress_loops
= 0;
3698 no_progress_loops
++;
3700 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3701 did_some_progress
> 0, no_progress_loops
))
3705 * It doesn't make any sense to retry for the compaction if the order-0
3706 * reclaim is not able to make any progress because the current
3707 * implementation of the compaction depends on the sufficient amount
3708 * of free memory (see __compaction_suitable)
3710 if (did_some_progress
> 0 &&
3711 should_compact_retry(ac
, order
, alloc_flags
,
3712 compact_result
, &migration_mode
,
3713 compaction_retries
))
3716 /* Reclaim has failed us, start killing things */
3717 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3721 /* Retry as long as the OOM killer is making progress */
3722 if (did_some_progress
) {
3723 no_progress_loops
= 0;
3729 * High-order allocations do not necessarily loop after direct reclaim
3730 * and reclaim/compaction depends on compaction being called after
3731 * reclaim so call directly if necessary.
3732 * It can become very expensive to allocate transparent hugepages at
3733 * fault, so use asynchronous memory compaction for THP unless it is
3734 * khugepaged trying to collapse. All other requests should tolerate
3735 * at least light sync migration.
3737 if (is_thp_gfp_mask(gfp_mask
) && !(current
->flags
& PF_KTHREAD
))
3738 migration_mode
= MIGRATE_ASYNC
;
3740 migration_mode
= MIGRATE_SYNC_LIGHT
;
3741 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3747 warn_alloc_failed(gfp_mask
, order
, NULL
);
3753 * This is the 'heart' of the zoned buddy allocator.
3756 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3757 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3760 unsigned int cpuset_mems_cookie
;
3761 unsigned int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_FAIR
;
3762 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
3763 struct alloc_context ac
= {
3764 .high_zoneidx
= gfp_zone(gfp_mask
),
3765 .zonelist
= zonelist
,
3766 .nodemask
= nodemask
,
3767 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3770 if (cpusets_enabled()) {
3771 alloc_mask
|= __GFP_HARDWALL
;
3772 alloc_flags
|= ALLOC_CPUSET
;
3774 ac
.nodemask
= &cpuset_current_mems_allowed
;
3777 gfp_mask
&= gfp_allowed_mask
;
3779 lockdep_trace_alloc(gfp_mask
);
3781 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3783 if (should_fail_alloc_page(gfp_mask
, order
))
3787 * Check the zones suitable for the gfp_mask contain at least one
3788 * valid zone. It's possible to have an empty zonelist as a result
3789 * of __GFP_THISNODE and a memoryless node
3791 if (unlikely(!zonelist
->_zonerefs
->zone
))
3794 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3795 alloc_flags
|= ALLOC_CMA
;
3798 cpuset_mems_cookie
= read_mems_allowed_begin();
3800 /* Dirty zone balancing only done in the fast path */
3801 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3803 /* The preferred zone is used for statistics later */
3804 ac
.preferred_zoneref
= first_zones_zonelist(ac
.zonelist
,
3805 ac
.high_zoneidx
, ac
.nodemask
);
3806 if (!ac
.preferred_zoneref
) {
3811 /* First allocation attempt */
3812 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3817 * Runtime PM, block IO and its error handling path can deadlock
3818 * because I/O on the device might not complete.
3820 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3821 ac
.spread_dirty_pages
= false;
3824 * Restore the original nodemask if it was potentially replaced with
3825 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3827 if (cpusets_enabled())
3828 ac
.nodemask
= nodemask
;
3829 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3833 * When updating a task's mems_allowed, it is possible to race with
3834 * parallel threads in such a way that an allocation can fail while
3835 * the mask is being updated. If a page allocation is about to fail,
3836 * check if the cpuset changed during allocation and if so, retry.
3838 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
))) {
3839 alloc_mask
= gfp_mask
;
3844 if (kmemcheck_enabled
&& page
)
3845 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3847 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3851 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3854 * Common helper functions.
3856 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3861 * __get_free_pages() returns a 32-bit address, which cannot represent
3864 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3866 page
= alloc_pages(gfp_mask
, order
);
3869 return (unsigned long) page_address(page
);
3871 EXPORT_SYMBOL(__get_free_pages
);
3873 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3875 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3877 EXPORT_SYMBOL(get_zeroed_page
);
3879 void __free_pages(struct page
*page
, unsigned int order
)
3881 if (put_page_testzero(page
)) {
3883 free_hot_cold_page(page
, false);
3885 __free_pages_ok(page
, order
);
3889 EXPORT_SYMBOL(__free_pages
);
3891 void free_pages(unsigned long addr
, unsigned int order
)
3894 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3895 __free_pages(virt_to_page((void *)addr
), order
);
3899 EXPORT_SYMBOL(free_pages
);
3903 * An arbitrary-length arbitrary-offset area of memory which resides
3904 * within a 0 or higher order page. Multiple fragments within that page
3905 * are individually refcounted, in the page's reference counter.
3907 * The page_frag functions below provide a simple allocation framework for
3908 * page fragments. This is used by the network stack and network device
3909 * drivers to provide a backing region of memory for use as either an
3910 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3912 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3915 struct page
*page
= NULL
;
3916 gfp_t gfp
= gfp_mask
;
3918 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3919 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3921 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3922 PAGE_FRAG_CACHE_MAX_ORDER
);
3923 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3925 if (unlikely(!page
))
3926 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3928 nc
->va
= page
? page_address(page
) : NULL
;
3933 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3934 unsigned int fragsz
, gfp_t gfp_mask
)
3936 unsigned int size
= PAGE_SIZE
;
3940 if (unlikely(!nc
->va
)) {
3942 page
= __page_frag_refill(nc
, gfp_mask
);
3946 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3947 /* if size can vary use size else just use PAGE_SIZE */
3950 /* Even if we own the page, we do not use atomic_set().
3951 * This would break get_page_unless_zero() users.
3953 page_ref_add(page
, size
- 1);
3955 /* reset page count bias and offset to start of new frag */
3956 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3957 nc
->pagecnt_bias
= size
;
3961 offset
= nc
->offset
- fragsz
;
3962 if (unlikely(offset
< 0)) {
3963 page
= virt_to_page(nc
->va
);
3965 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3968 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3969 /* if size can vary use size else just use PAGE_SIZE */
3972 /* OK, page count is 0, we can safely set it */
3973 set_page_count(page
, size
);
3975 /* reset page count bias and offset to start of new frag */
3976 nc
->pagecnt_bias
= size
;
3977 offset
= size
- fragsz
;
3981 nc
->offset
= offset
;
3983 return nc
->va
+ offset
;
3985 EXPORT_SYMBOL(__alloc_page_frag
);
3988 * Frees a page fragment allocated out of either a compound or order 0 page.
3990 void __free_page_frag(void *addr
)
3992 struct page
*page
= virt_to_head_page(addr
);
3994 if (unlikely(put_page_testzero(page
)))
3995 __free_pages_ok(page
, compound_order(page
));
3997 EXPORT_SYMBOL(__free_page_frag
);
4000 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
4001 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
4002 * equivalent to alloc_pages.
4004 * It should be used when the caller would like to use kmalloc, but since the
4005 * allocation is large, it has to fall back to the page allocator.
4007 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
4011 page
= alloc_pages(gfp_mask
, order
);
4012 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
4013 __free_pages(page
, order
);
4019 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
4023 page
= alloc_pages_node(nid
, gfp_mask
, order
);
4024 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
4025 __free_pages(page
, order
);
4032 * __free_kmem_pages and free_kmem_pages will free pages allocated with
4035 void __free_kmem_pages(struct page
*page
, unsigned int order
)
4037 memcg_kmem_uncharge(page
, order
);
4038 __free_pages(page
, order
);
4041 void free_kmem_pages(unsigned long addr
, unsigned int order
)
4044 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4045 __free_kmem_pages(virt_to_page((void *)addr
), order
);
4049 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4053 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4054 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4056 split_page(virt_to_page((void *)addr
), order
);
4057 while (used
< alloc_end
) {
4062 return (void *)addr
;
4066 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4067 * @size: the number of bytes to allocate
4068 * @gfp_mask: GFP flags for the allocation
4070 * This function is similar to alloc_pages(), except that it allocates the
4071 * minimum number of pages to satisfy the request. alloc_pages() can only
4072 * allocate memory in power-of-two pages.
4074 * This function is also limited by MAX_ORDER.
4076 * Memory allocated by this function must be released by free_pages_exact().
4078 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4080 unsigned int order
= get_order(size
);
4083 addr
= __get_free_pages(gfp_mask
, order
);
4084 return make_alloc_exact(addr
, order
, size
);
4086 EXPORT_SYMBOL(alloc_pages_exact
);
4089 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4091 * @nid: the preferred node ID where memory should be allocated
4092 * @size: the number of bytes to allocate
4093 * @gfp_mask: GFP flags for the allocation
4095 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4098 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4100 unsigned int order
= get_order(size
);
4101 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4104 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4108 * free_pages_exact - release memory allocated via alloc_pages_exact()
4109 * @virt: the value returned by alloc_pages_exact.
4110 * @size: size of allocation, same value as passed to alloc_pages_exact().
4112 * Release the memory allocated by a previous call to alloc_pages_exact.
4114 void free_pages_exact(void *virt
, size_t size
)
4116 unsigned long addr
= (unsigned long)virt
;
4117 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4119 while (addr
< end
) {
4124 EXPORT_SYMBOL(free_pages_exact
);
4127 * nr_free_zone_pages - count number of pages beyond high watermark
4128 * @offset: The zone index of the highest zone
4130 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4131 * high watermark within all zones at or below a given zone index. For each
4132 * zone, the number of pages is calculated as:
4133 * managed_pages - high_pages
4135 static unsigned long nr_free_zone_pages(int offset
)
4140 /* Just pick one node, since fallback list is circular */
4141 unsigned long sum
= 0;
4143 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4145 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4146 unsigned long size
= zone
->managed_pages
;
4147 unsigned long high
= high_wmark_pages(zone
);
4156 * nr_free_buffer_pages - count number of pages beyond high watermark
4158 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4159 * watermark within ZONE_DMA and ZONE_NORMAL.
4161 unsigned long nr_free_buffer_pages(void)
4163 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4165 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4168 * nr_free_pagecache_pages - count number of pages beyond high watermark
4170 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4171 * high watermark within all zones.
4173 unsigned long nr_free_pagecache_pages(void)
4175 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4178 static inline void show_node(struct zone
*zone
)
4180 if (IS_ENABLED(CONFIG_NUMA
))
4181 printk("Node %d ", zone_to_nid(zone
));
4184 long si_mem_available(void)
4187 unsigned long pagecache
;
4188 unsigned long wmark_low
= 0;
4189 unsigned long pages
[NR_LRU_LISTS
];
4193 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4194 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
4197 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4200 * Estimate the amount of memory available for userspace allocations,
4201 * without causing swapping.
4203 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4206 * Not all the page cache can be freed, otherwise the system will
4207 * start swapping. Assume at least half of the page cache, or the
4208 * low watermark worth of cache, needs to stay.
4210 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4211 pagecache
-= min(pagecache
/ 2, wmark_low
);
4212 available
+= pagecache
;
4215 * Part of the reclaimable slab consists of items that are in use,
4216 * and cannot be freed. Cap this estimate at the low watermark.
4218 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4219 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4225 EXPORT_SYMBOL_GPL(si_mem_available
);
4227 void si_meminfo(struct sysinfo
*val
)
4229 val
->totalram
= totalram_pages
;
4230 val
->sharedram
= global_page_state(NR_SHMEM
);
4231 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4232 val
->bufferram
= nr_blockdev_pages();
4233 val
->totalhigh
= totalhigh_pages
;
4234 val
->freehigh
= nr_free_highpages();
4235 val
->mem_unit
= PAGE_SIZE
;
4238 EXPORT_SYMBOL(si_meminfo
);
4241 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4243 int zone_type
; /* needs to be signed */
4244 unsigned long managed_pages
= 0;
4245 unsigned long managed_highpages
= 0;
4246 unsigned long free_highpages
= 0;
4247 pg_data_t
*pgdat
= NODE_DATA(nid
);
4249 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4250 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4251 val
->totalram
= managed_pages
;
4252 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
4253 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
4254 #ifdef CONFIG_HIGHMEM
4255 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4256 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4258 if (is_highmem(zone
)) {
4259 managed_highpages
+= zone
->managed_pages
;
4260 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4263 val
->totalhigh
= managed_highpages
;
4264 val
->freehigh
= free_highpages
;
4266 val
->totalhigh
= managed_highpages
;
4267 val
->freehigh
= free_highpages
;
4269 val
->mem_unit
= PAGE_SIZE
;
4274 * Determine whether the node should be displayed or not, depending on whether
4275 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4277 bool skip_free_areas_node(unsigned int flags
, int nid
)
4280 unsigned int cpuset_mems_cookie
;
4282 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4286 cpuset_mems_cookie
= read_mems_allowed_begin();
4287 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
4288 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
4293 #define K(x) ((x) << (PAGE_SHIFT-10))
4295 static void show_migration_types(unsigned char type
)
4297 static const char types
[MIGRATE_TYPES
] = {
4298 [MIGRATE_UNMOVABLE
] = 'U',
4299 [MIGRATE_MOVABLE
] = 'M',
4300 [MIGRATE_RECLAIMABLE
] = 'E',
4301 [MIGRATE_HIGHATOMIC
] = 'H',
4303 [MIGRATE_CMA
] = 'C',
4305 #ifdef CONFIG_MEMORY_ISOLATION
4306 [MIGRATE_ISOLATE
] = 'I',
4309 char tmp
[MIGRATE_TYPES
+ 1];
4313 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4314 if (type
& (1 << i
))
4319 printk("(%s) ", tmp
);
4323 * Show free area list (used inside shift_scroll-lock stuff)
4324 * We also calculate the percentage fragmentation. We do this by counting the
4325 * memory on each free list with the exception of the first item on the list.
4328 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4331 void show_free_areas(unsigned int filter
)
4333 unsigned long free_pcp
= 0;
4337 for_each_populated_zone(zone
) {
4338 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4341 for_each_online_cpu(cpu
)
4342 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4345 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4346 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4347 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4348 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4349 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4350 " free:%lu free_pcp:%lu free_cma:%lu\n",
4351 global_page_state(NR_ACTIVE_ANON
),
4352 global_page_state(NR_INACTIVE_ANON
),
4353 global_page_state(NR_ISOLATED_ANON
),
4354 global_page_state(NR_ACTIVE_FILE
),
4355 global_page_state(NR_INACTIVE_FILE
),
4356 global_page_state(NR_ISOLATED_FILE
),
4357 global_page_state(NR_UNEVICTABLE
),
4358 global_page_state(NR_FILE_DIRTY
),
4359 global_page_state(NR_WRITEBACK
),
4360 global_page_state(NR_UNSTABLE_NFS
),
4361 global_page_state(NR_SLAB_RECLAIMABLE
),
4362 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4363 global_page_state(NR_FILE_MAPPED
),
4364 global_page_state(NR_SHMEM
),
4365 global_page_state(NR_PAGETABLE
),
4366 global_page_state(NR_BOUNCE
),
4367 global_page_state(NR_FREE_PAGES
),
4369 global_page_state(NR_FREE_CMA_PAGES
));
4371 for_each_populated_zone(zone
) {
4374 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4378 for_each_online_cpu(cpu
)
4379 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4387 " active_anon:%lukB"
4388 " inactive_anon:%lukB"
4389 " active_file:%lukB"
4390 " inactive_file:%lukB"
4391 " unevictable:%lukB"
4392 " isolated(anon):%lukB"
4393 " isolated(file):%lukB"
4401 " slab_reclaimable:%lukB"
4402 " slab_unreclaimable:%lukB"
4403 " kernel_stack:%lukB"
4410 " writeback_tmp:%lukB"
4411 " pages_scanned:%lu"
4412 " all_unreclaimable? %s"
4415 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4416 K(min_wmark_pages(zone
)),
4417 K(low_wmark_pages(zone
)),
4418 K(high_wmark_pages(zone
)),
4419 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
4420 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
4421 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
4422 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
4423 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
4424 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
4425 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
4426 K(zone
->present_pages
),
4427 K(zone
->managed_pages
),
4428 K(zone_page_state(zone
, NR_MLOCK
)),
4429 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
4430 K(zone_page_state(zone
, NR_WRITEBACK
)),
4431 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
4432 K(zone_page_state(zone
, NR_SHMEM
)),
4433 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
4434 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
4435 zone_page_state(zone
, NR_KERNEL_STACK
) *
4437 K(zone_page_state(zone
, NR_PAGETABLE
)),
4438 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
4439 K(zone_page_state(zone
, NR_BOUNCE
)),
4441 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4442 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
4443 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
4444 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
4445 (!zone_reclaimable(zone
) ? "yes" : "no")
4447 printk("lowmem_reserve[]:");
4448 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4449 printk(" %ld", zone
->lowmem_reserve
[i
]);
4453 for_each_populated_zone(zone
) {
4455 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4456 unsigned char types
[MAX_ORDER
];
4458 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4461 printk("%s: ", zone
->name
);
4463 spin_lock_irqsave(&zone
->lock
, flags
);
4464 for (order
= 0; order
< MAX_ORDER
; order
++) {
4465 struct free_area
*area
= &zone
->free_area
[order
];
4468 nr
[order
] = area
->nr_free
;
4469 total
+= nr
[order
] << order
;
4472 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4473 if (!list_empty(&area
->free_list
[type
]))
4474 types
[order
] |= 1 << type
;
4477 spin_unlock_irqrestore(&zone
->lock
, flags
);
4478 for (order
= 0; order
< MAX_ORDER
; order
++) {
4479 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4481 show_migration_types(types
[order
]);
4483 printk("= %lukB\n", K(total
));
4486 hugetlb_show_meminfo();
4488 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4490 show_swap_cache_info();
4493 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4495 zoneref
->zone
= zone
;
4496 zoneref
->zone_idx
= zone_idx(zone
);
4500 * Builds allocation fallback zone lists.
4502 * Add all populated zones of a node to the zonelist.
4504 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4508 enum zone_type zone_type
= MAX_NR_ZONES
;
4512 zone
= pgdat
->node_zones
+ zone_type
;
4513 if (populated_zone(zone
)) {
4514 zoneref_set_zone(zone
,
4515 &zonelist
->_zonerefs
[nr_zones
++]);
4516 check_highest_zone(zone_type
);
4518 } while (zone_type
);
4526 * 0 = automatic detection of better ordering.
4527 * 1 = order by ([node] distance, -zonetype)
4528 * 2 = order by (-zonetype, [node] distance)
4530 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4531 * the same zonelist. So only NUMA can configure this param.
4533 #define ZONELIST_ORDER_DEFAULT 0
4534 #define ZONELIST_ORDER_NODE 1
4535 #define ZONELIST_ORDER_ZONE 2
4537 /* zonelist order in the kernel.
4538 * set_zonelist_order() will set this to NODE or ZONE.
4540 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4541 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4545 /* The value user specified ....changed by config */
4546 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4547 /* string for sysctl */
4548 #define NUMA_ZONELIST_ORDER_LEN 16
4549 char numa_zonelist_order
[16] = "default";
4552 * interface for configure zonelist ordering.
4553 * command line option "numa_zonelist_order"
4554 * = "[dD]efault - default, automatic configuration.
4555 * = "[nN]ode - order by node locality, then by zone within node
4556 * = "[zZ]one - order by zone, then by locality within zone
4559 static int __parse_numa_zonelist_order(char *s
)
4561 if (*s
== 'd' || *s
== 'D') {
4562 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4563 } else if (*s
== 'n' || *s
== 'N') {
4564 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4565 } else if (*s
== 'z' || *s
== 'Z') {
4566 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4568 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4574 static __init
int setup_numa_zonelist_order(char *s
)
4581 ret
= __parse_numa_zonelist_order(s
);
4583 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4587 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4590 * sysctl handler for numa_zonelist_order
4592 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4593 void __user
*buffer
, size_t *length
,
4596 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4598 static DEFINE_MUTEX(zl_order_mutex
);
4600 mutex_lock(&zl_order_mutex
);
4602 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4606 strcpy(saved_string
, (char *)table
->data
);
4608 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4612 int oldval
= user_zonelist_order
;
4614 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4617 * bogus value. restore saved string
4619 strncpy((char *)table
->data
, saved_string
,
4620 NUMA_ZONELIST_ORDER_LEN
);
4621 user_zonelist_order
= oldval
;
4622 } else if (oldval
!= user_zonelist_order
) {
4623 mutex_lock(&zonelists_mutex
);
4624 build_all_zonelists(NULL
, NULL
);
4625 mutex_unlock(&zonelists_mutex
);
4629 mutex_unlock(&zl_order_mutex
);
4634 #define MAX_NODE_LOAD (nr_online_nodes)
4635 static int node_load
[MAX_NUMNODES
];
4638 * find_next_best_node - find the next node that should appear in a given node's fallback list
4639 * @node: node whose fallback list we're appending
4640 * @used_node_mask: nodemask_t of already used nodes
4642 * We use a number of factors to determine which is the next node that should
4643 * appear on a given node's fallback list. The node should not have appeared
4644 * already in @node's fallback list, and it should be the next closest node
4645 * according to the distance array (which contains arbitrary distance values
4646 * from each node to each node in the system), and should also prefer nodes
4647 * with no CPUs, since presumably they'll have very little allocation pressure
4648 * on them otherwise.
4649 * It returns -1 if no node is found.
4651 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4654 int min_val
= INT_MAX
;
4655 int best_node
= NUMA_NO_NODE
;
4656 const struct cpumask
*tmp
= cpumask_of_node(0);
4658 /* Use the local node if we haven't already */
4659 if (!node_isset(node
, *used_node_mask
)) {
4660 node_set(node
, *used_node_mask
);
4664 for_each_node_state(n
, N_MEMORY
) {
4666 /* Don't want a node to appear more than once */
4667 if (node_isset(n
, *used_node_mask
))
4670 /* Use the distance array to find the distance */
4671 val
= node_distance(node
, n
);
4673 /* Penalize nodes under us ("prefer the next node") */
4676 /* Give preference to headless and unused nodes */
4677 tmp
= cpumask_of_node(n
);
4678 if (!cpumask_empty(tmp
))
4679 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4681 /* Slight preference for less loaded node */
4682 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4683 val
+= node_load
[n
];
4685 if (val
< min_val
) {
4692 node_set(best_node
, *used_node_mask
);
4699 * Build zonelists ordered by node and zones within node.
4700 * This results in maximum locality--normal zone overflows into local
4701 * DMA zone, if any--but risks exhausting DMA zone.
4703 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4706 struct zonelist
*zonelist
;
4708 zonelist
= &pgdat
->node_zonelists
[0];
4709 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4711 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4712 zonelist
->_zonerefs
[j
].zone
= NULL
;
4713 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4717 * Build gfp_thisnode zonelists
4719 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4722 struct zonelist
*zonelist
;
4724 zonelist
= &pgdat
->node_zonelists
[1];
4725 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4726 zonelist
->_zonerefs
[j
].zone
= NULL
;
4727 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4731 * Build zonelists ordered by zone and nodes within zones.
4732 * This results in conserving DMA zone[s] until all Normal memory is
4733 * exhausted, but results in overflowing to remote node while memory
4734 * may still exist in local DMA zone.
4736 static int node_order
[MAX_NUMNODES
];
4738 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4741 int zone_type
; /* needs to be signed */
4743 struct zonelist
*zonelist
;
4745 zonelist
= &pgdat
->node_zonelists
[0];
4747 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4748 for (j
= 0; j
< nr_nodes
; j
++) {
4749 node
= node_order
[j
];
4750 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4751 if (populated_zone(z
)) {
4753 &zonelist
->_zonerefs
[pos
++]);
4754 check_highest_zone(zone_type
);
4758 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4759 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4762 #if defined(CONFIG_64BIT)
4764 * Devices that require DMA32/DMA are relatively rare and do not justify a
4765 * penalty to every machine in case the specialised case applies. Default
4766 * to Node-ordering on 64-bit NUMA machines
4768 static int default_zonelist_order(void)
4770 return ZONELIST_ORDER_NODE
;
4774 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4775 * by the kernel. If processes running on node 0 deplete the low memory zone
4776 * then reclaim will occur more frequency increasing stalls and potentially
4777 * be easier to OOM if a large percentage of the zone is under writeback or
4778 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4779 * Hence, default to zone ordering on 32-bit.
4781 static int default_zonelist_order(void)
4783 return ZONELIST_ORDER_ZONE
;
4785 #endif /* CONFIG_64BIT */
4787 static void set_zonelist_order(void)
4789 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4790 current_zonelist_order
= default_zonelist_order();
4792 current_zonelist_order
= user_zonelist_order
;
4795 static void build_zonelists(pg_data_t
*pgdat
)
4798 nodemask_t used_mask
;
4799 int local_node
, prev_node
;
4800 struct zonelist
*zonelist
;
4801 unsigned int order
= current_zonelist_order
;
4803 /* initialize zonelists */
4804 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4805 zonelist
= pgdat
->node_zonelists
+ i
;
4806 zonelist
->_zonerefs
[0].zone
= NULL
;
4807 zonelist
->_zonerefs
[0].zone_idx
= 0;
4810 /* NUMA-aware ordering of nodes */
4811 local_node
= pgdat
->node_id
;
4812 load
= nr_online_nodes
;
4813 prev_node
= local_node
;
4814 nodes_clear(used_mask
);
4816 memset(node_order
, 0, sizeof(node_order
));
4819 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4821 * We don't want to pressure a particular node.
4822 * So adding penalty to the first node in same
4823 * distance group to make it round-robin.
4825 if (node_distance(local_node
, node
) !=
4826 node_distance(local_node
, prev_node
))
4827 node_load
[node
] = load
;
4831 if (order
== ZONELIST_ORDER_NODE
)
4832 build_zonelists_in_node_order(pgdat
, node
);
4834 node_order
[i
++] = node
; /* remember order */
4837 if (order
== ZONELIST_ORDER_ZONE
) {
4838 /* calculate node order -- i.e., DMA last! */
4839 build_zonelists_in_zone_order(pgdat
, i
);
4842 build_thisnode_zonelists(pgdat
);
4845 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4847 * Return node id of node used for "local" allocations.
4848 * I.e., first node id of first zone in arg node's generic zonelist.
4849 * Used for initializing percpu 'numa_mem', which is used primarily
4850 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4852 int local_memory_node(int node
)
4856 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4857 gfp_zone(GFP_KERNEL
),
4859 return z
->zone
->node
;
4863 #else /* CONFIG_NUMA */
4865 static void set_zonelist_order(void)
4867 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4870 static void build_zonelists(pg_data_t
*pgdat
)
4872 int node
, local_node
;
4874 struct zonelist
*zonelist
;
4876 local_node
= pgdat
->node_id
;
4878 zonelist
= &pgdat
->node_zonelists
[0];
4879 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4882 * Now we build the zonelist so that it contains the zones
4883 * of all the other nodes.
4884 * We don't want to pressure a particular node, so when
4885 * building the zones for node N, we make sure that the
4886 * zones coming right after the local ones are those from
4887 * node N+1 (modulo N)
4889 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4890 if (!node_online(node
))
4892 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4894 for (node
= 0; node
< local_node
; node
++) {
4895 if (!node_online(node
))
4897 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4900 zonelist
->_zonerefs
[j
].zone
= NULL
;
4901 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4904 #endif /* CONFIG_NUMA */
4907 * Boot pageset table. One per cpu which is going to be used for all
4908 * zones and all nodes. The parameters will be set in such a way
4909 * that an item put on a list will immediately be handed over to
4910 * the buddy list. This is safe since pageset manipulation is done
4911 * with interrupts disabled.
4913 * The boot_pagesets must be kept even after bootup is complete for
4914 * unused processors and/or zones. They do play a role for bootstrapping
4915 * hotplugged processors.
4917 * zoneinfo_show() and maybe other functions do
4918 * not check if the processor is online before following the pageset pointer.
4919 * Other parts of the kernel may not check if the zone is available.
4921 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4922 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4923 static void setup_zone_pageset(struct zone
*zone
);
4926 * Global mutex to protect against size modification of zonelists
4927 * as well as to serialize pageset setup for the new populated zone.
4929 DEFINE_MUTEX(zonelists_mutex
);
4931 /* return values int ....just for stop_machine() */
4932 static int __build_all_zonelists(void *data
)
4936 pg_data_t
*self
= data
;
4939 memset(node_load
, 0, sizeof(node_load
));
4942 if (self
&& !node_online(self
->node_id
)) {
4943 build_zonelists(self
);
4946 for_each_online_node(nid
) {
4947 pg_data_t
*pgdat
= NODE_DATA(nid
);
4949 build_zonelists(pgdat
);
4953 * Initialize the boot_pagesets that are going to be used
4954 * for bootstrapping processors. The real pagesets for
4955 * each zone will be allocated later when the per cpu
4956 * allocator is available.
4958 * boot_pagesets are used also for bootstrapping offline
4959 * cpus if the system is already booted because the pagesets
4960 * are needed to initialize allocators on a specific cpu too.
4961 * F.e. the percpu allocator needs the page allocator which
4962 * needs the percpu allocator in order to allocate its pagesets
4963 * (a chicken-egg dilemma).
4965 for_each_possible_cpu(cpu
) {
4966 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4968 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4970 * We now know the "local memory node" for each node--
4971 * i.e., the node of the first zone in the generic zonelist.
4972 * Set up numa_mem percpu variable for on-line cpus. During
4973 * boot, only the boot cpu should be on-line; we'll init the
4974 * secondary cpus' numa_mem as they come on-line. During
4975 * node/memory hotplug, we'll fixup all on-line cpus.
4977 if (cpu_online(cpu
))
4978 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4985 static noinline
void __init
4986 build_all_zonelists_init(void)
4988 __build_all_zonelists(NULL
);
4989 mminit_verify_zonelist();
4990 cpuset_init_current_mems_allowed();
4994 * Called with zonelists_mutex held always
4995 * unless system_state == SYSTEM_BOOTING.
4997 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4998 * [we're only called with non-NULL zone through __meminit paths] and
4999 * (2) call of __init annotated helper build_all_zonelists_init
5000 * [protected by SYSTEM_BOOTING].
5002 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
5004 set_zonelist_order();
5006 if (system_state
== SYSTEM_BOOTING
) {
5007 build_all_zonelists_init();
5009 #ifdef CONFIG_MEMORY_HOTPLUG
5011 setup_zone_pageset(zone
);
5013 /* we have to stop all cpus to guarantee there is no user
5015 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
5016 /* cpuset refresh routine should be here */
5018 vm_total_pages
= nr_free_pagecache_pages();
5020 * Disable grouping by mobility if the number of pages in the
5021 * system is too low to allow the mechanism to work. It would be
5022 * more accurate, but expensive to check per-zone. This check is
5023 * made on memory-hotadd so a system can start with mobility
5024 * disabled and enable it later
5026 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5027 page_group_by_mobility_disabled
= 1;
5029 page_group_by_mobility_disabled
= 0;
5031 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5033 zonelist_order_name
[current_zonelist_order
],
5034 page_group_by_mobility_disabled
? "off" : "on",
5037 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5042 * Helper functions to size the waitqueue hash table.
5043 * Essentially these want to choose hash table sizes sufficiently
5044 * large so that collisions trying to wait on pages are rare.
5045 * But in fact, the number of active page waitqueues on typical
5046 * systems is ridiculously low, less than 200. So this is even
5047 * conservative, even though it seems large.
5049 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
5050 * waitqueues, i.e. the size of the waitq table given the number of pages.
5052 #define PAGES_PER_WAITQUEUE 256
5054 #ifndef CONFIG_MEMORY_HOTPLUG
5055 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5057 unsigned long size
= 1;
5059 pages
/= PAGES_PER_WAITQUEUE
;
5061 while (size
< pages
)
5065 * Once we have dozens or even hundreds of threads sleeping
5066 * on IO we've got bigger problems than wait queue collision.
5067 * Limit the size of the wait table to a reasonable size.
5069 size
= min(size
, 4096UL);
5071 return max(size
, 4UL);
5075 * A zone's size might be changed by hot-add, so it is not possible to determine
5076 * a suitable size for its wait_table. So we use the maximum size now.
5078 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5080 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5081 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5082 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5084 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5085 * or more by the traditional way. (See above). It equals:
5087 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5088 * ia64(16K page size) : = ( 8G + 4M)byte.
5089 * powerpc (64K page size) : = (32G +16M)byte.
5091 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5098 * This is an integer logarithm so that shifts can be used later
5099 * to extract the more random high bits from the multiplicative
5100 * hash function before the remainder is taken.
5102 static inline unsigned long wait_table_bits(unsigned long size
)
5108 * Initially all pages are reserved - free ones are freed
5109 * up by free_all_bootmem() once the early boot process is
5110 * done. Non-atomic initialization, single-pass.
5112 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5113 unsigned long start_pfn
, enum memmap_context context
)
5115 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5116 unsigned long end_pfn
= start_pfn
+ size
;
5117 pg_data_t
*pgdat
= NODE_DATA(nid
);
5119 unsigned long nr_initialised
= 0;
5120 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5121 struct memblock_region
*r
= NULL
, *tmp
;
5124 if (highest_memmap_pfn
< end_pfn
- 1)
5125 highest_memmap_pfn
= end_pfn
- 1;
5128 * Honor reservation requested by the driver for this ZONE_DEVICE
5131 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5132 start_pfn
+= altmap
->reserve
;
5134 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5136 * There can be holes in boot-time mem_map[]s handed to this
5137 * function. They do not exist on hotplugged memory.
5139 if (context
!= MEMMAP_EARLY
)
5142 if (!early_pfn_valid(pfn
))
5144 if (!early_pfn_in_nid(pfn
, nid
))
5146 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5149 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5151 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5152 * from zone_movable_pfn[nid] to end of each node should be
5153 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5155 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
5156 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
5160 * Check given memblock attribute by firmware which can affect
5161 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5162 * mirrored, it's an overlapped memmap init. skip it.
5164 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5165 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5166 for_each_memblock(memory
, tmp
)
5167 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5171 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5172 memblock_is_mirror(r
)) {
5173 /* already initialized as NORMAL */
5174 pfn
= memblock_region_memory_end_pfn(r
);
5182 * Mark the block movable so that blocks are reserved for
5183 * movable at startup. This will force kernel allocations
5184 * to reserve their blocks rather than leaking throughout
5185 * the address space during boot when many long-lived
5186 * kernel allocations are made.
5188 * bitmap is created for zone's valid pfn range. but memmap
5189 * can be created for invalid pages (for alignment)
5190 * check here not to call set_pageblock_migratetype() against
5193 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5194 struct page
*page
= pfn_to_page(pfn
);
5196 __init_single_page(page
, pfn
, zone
, nid
);
5197 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5199 __init_single_pfn(pfn
, zone
, nid
);
5204 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5206 unsigned int order
, t
;
5207 for_each_migratetype_order(order
, t
) {
5208 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5209 zone
->free_area
[order
].nr_free
= 0;
5213 #ifndef __HAVE_ARCH_MEMMAP_INIT
5214 #define memmap_init(size, nid, zone, start_pfn) \
5215 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5218 static int zone_batchsize(struct zone
*zone
)
5224 * The per-cpu-pages pools are set to around 1000th of the
5225 * size of the zone. But no more than 1/2 of a meg.
5227 * OK, so we don't know how big the cache is. So guess.
5229 batch
= zone
->managed_pages
/ 1024;
5230 if (batch
* PAGE_SIZE
> 512 * 1024)
5231 batch
= (512 * 1024) / PAGE_SIZE
;
5232 batch
/= 4; /* We effectively *= 4 below */
5237 * Clamp the batch to a 2^n - 1 value. Having a power
5238 * of 2 value was found to be more likely to have
5239 * suboptimal cache aliasing properties in some cases.
5241 * For example if 2 tasks are alternately allocating
5242 * batches of pages, one task can end up with a lot
5243 * of pages of one half of the possible page colors
5244 * and the other with pages of the other colors.
5246 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5251 /* The deferral and batching of frees should be suppressed under NOMMU
5254 * The problem is that NOMMU needs to be able to allocate large chunks
5255 * of contiguous memory as there's no hardware page translation to
5256 * assemble apparent contiguous memory from discontiguous pages.
5258 * Queueing large contiguous runs of pages for batching, however,
5259 * causes the pages to actually be freed in smaller chunks. As there
5260 * can be a significant delay between the individual batches being
5261 * recycled, this leads to the once large chunks of space being
5262 * fragmented and becoming unavailable for high-order allocations.
5269 * pcp->high and pcp->batch values are related and dependent on one another:
5270 * ->batch must never be higher then ->high.
5271 * The following function updates them in a safe manner without read side
5274 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5275 * those fields changing asynchronously (acording the the above rule).
5277 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5278 * outside of boot time (or some other assurance that no concurrent updaters
5281 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5282 unsigned long batch
)
5284 /* start with a fail safe value for batch */
5288 /* Update high, then batch, in order */
5295 /* a companion to pageset_set_high() */
5296 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5298 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5301 static void pageset_init(struct per_cpu_pageset
*p
)
5303 struct per_cpu_pages
*pcp
;
5306 memset(p
, 0, sizeof(*p
));
5310 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5311 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5314 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5317 pageset_set_batch(p
, batch
);
5321 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5322 * to the value high for the pageset p.
5324 static void pageset_set_high(struct per_cpu_pageset
*p
,
5327 unsigned long batch
= max(1UL, high
/ 4);
5328 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5329 batch
= PAGE_SHIFT
* 8;
5331 pageset_update(&p
->pcp
, high
, batch
);
5334 static void pageset_set_high_and_batch(struct zone
*zone
,
5335 struct per_cpu_pageset
*pcp
)
5337 if (percpu_pagelist_fraction
)
5338 pageset_set_high(pcp
,
5339 (zone
->managed_pages
/
5340 percpu_pagelist_fraction
));
5342 pageset_set_batch(pcp
, zone_batchsize(zone
));
5345 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5347 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5350 pageset_set_high_and_batch(zone
, pcp
);
5353 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5356 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5357 for_each_possible_cpu(cpu
)
5358 zone_pageset_init(zone
, cpu
);
5362 * Allocate per cpu pagesets and initialize them.
5363 * Before this call only boot pagesets were available.
5365 void __init
setup_per_cpu_pageset(void)
5369 for_each_populated_zone(zone
)
5370 setup_zone_pageset(zone
);
5373 static noinline __init_refok
5374 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
5380 * The per-page waitqueue mechanism uses hashed waitqueues
5383 zone
->wait_table_hash_nr_entries
=
5384 wait_table_hash_nr_entries(zone_size_pages
);
5385 zone
->wait_table_bits
=
5386 wait_table_bits(zone
->wait_table_hash_nr_entries
);
5387 alloc_size
= zone
->wait_table_hash_nr_entries
5388 * sizeof(wait_queue_head_t
);
5390 if (!slab_is_available()) {
5391 zone
->wait_table
= (wait_queue_head_t
*)
5392 memblock_virt_alloc_node_nopanic(
5393 alloc_size
, zone
->zone_pgdat
->node_id
);
5396 * This case means that a zone whose size was 0 gets new memory
5397 * via memory hot-add.
5398 * But it may be the case that a new node was hot-added. In
5399 * this case vmalloc() will not be able to use this new node's
5400 * memory - this wait_table must be initialized to use this new
5401 * node itself as well.
5402 * To use this new node's memory, further consideration will be
5405 zone
->wait_table
= vmalloc(alloc_size
);
5407 if (!zone
->wait_table
)
5410 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
5411 init_waitqueue_head(zone
->wait_table
+ i
);
5416 static __meminit
void zone_pcp_init(struct zone
*zone
)
5419 * per cpu subsystem is not up at this point. The following code
5420 * relies on the ability of the linker to provide the
5421 * offset of a (static) per cpu variable into the per cpu area.
5423 zone
->pageset
= &boot_pageset
;
5425 if (populated_zone(zone
))
5426 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5427 zone
->name
, zone
->present_pages
,
5428 zone_batchsize(zone
));
5431 int __meminit
init_currently_empty_zone(struct zone
*zone
,
5432 unsigned long zone_start_pfn
,
5435 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5437 ret
= zone_wait_table_init(zone
, size
);
5440 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5442 zone
->zone_start_pfn
= zone_start_pfn
;
5444 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5445 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5447 (unsigned long)zone_idx(zone
),
5448 zone_start_pfn
, (zone_start_pfn
+ size
));
5450 zone_init_free_lists(zone
);
5455 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5456 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5459 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5461 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5462 struct mminit_pfnnid_cache
*state
)
5464 unsigned long start_pfn
, end_pfn
;
5467 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5468 return state
->last_nid
;
5470 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5472 state
->last_start
= start_pfn
;
5473 state
->last_end
= end_pfn
;
5474 state
->last_nid
= nid
;
5479 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5482 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5483 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5484 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5486 * If an architecture guarantees that all ranges registered contain no holes
5487 * and may be freed, this this function may be used instead of calling
5488 * memblock_free_early_nid() manually.
5490 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5492 unsigned long start_pfn
, end_pfn
;
5495 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5496 start_pfn
= min(start_pfn
, max_low_pfn
);
5497 end_pfn
= min(end_pfn
, max_low_pfn
);
5499 if (start_pfn
< end_pfn
)
5500 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5501 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5507 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5508 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5510 * If an architecture guarantees that all ranges registered contain no holes and may
5511 * be freed, this function may be used instead of calling memory_present() manually.
5513 void __init
sparse_memory_present_with_active_regions(int nid
)
5515 unsigned long start_pfn
, end_pfn
;
5518 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5519 memory_present(this_nid
, start_pfn
, end_pfn
);
5523 * get_pfn_range_for_nid - Return the start and end page frames for a node
5524 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5525 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5526 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5528 * It returns the start and end page frame of a node based on information
5529 * provided by memblock_set_node(). If called for a node
5530 * with no available memory, a warning is printed and the start and end
5533 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5534 unsigned long *start_pfn
, unsigned long *end_pfn
)
5536 unsigned long this_start_pfn
, this_end_pfn
;
5542 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5543 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5544 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5547 if (*start_pfn
== -1UL)
5552 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5553 * assumption is made that zones within a node are ordered in monotonic
5554 * increasing memory addresses so that the "highest" populated zone is used
5556 static void __init
find_usable_zone_for_movable(void)
5559 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5560 if (zone_index
== ZONE_MOVABLE
)
5563 if (arch_zone_highest_possible_pfn
[zone_index
] >
5564 arch_zone_lowest_possible_pfn
[zone_index
])
5568 VM_BUG_ON(zone_index
== -1);
5569 movable_zone
= zone_index
;
5573 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5574 * because it is sized independent of architecture. Unlike the other zones,
5575 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5576 * in each node depending on the size of each node and how evenly kernelcore
5577 * is distributed. This helper function adjusts the zone ranges
5578 * provided by the architecture for a given node by using the end of the
5579 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5580 * zones within a node are in order of monotonic increases memory addresses
5582 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5583 unsigned long zone_type
,
5584 unsigned long node_start_pfn
,
5585 unsigned long node_end_pfn
,
5586 unsigned long *zone_start_pfn
,
5587 unsigned long *zone_end_pfn
)
5589 /* Only adjust if ZONE_MOVABLE is on this node */
5590 if (zone_movable_pfn
[nid
]) {
5591 /* Size ZONE_MOVABLE */
5592 if (zone_type
== ZONE_MOVABLE
) {
5593 *zone_start_pfn
= zone_movable_pfn
[nid
];
5594 *zone_end_pfn
= min(node_end_pfn
,
5595 arch_zone_highest_possible_pfn
[movable_zone
]);
5597 /* Check if this whole range is within ZONE_MOVABLE */
5598 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5599 *zone_start_pfn
= *zone_end_pfn
;
5604 * Return the number of pages a zone spans in a node, including holes
5605 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5607 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5608 unsigned long zone_type
,
5609 unsigned long node_start_pfn
,
5610 unsigned long node_end_pfn
,
5611 unsigned long *zone_start_pfn
,
5612 unsigned long *zone_end_pfn
,
5613 unsigned long *ignored
)
5615 /* When hotadd a new node from cpu_up(), the node should be empty */
5616 if (!node_start_pfn
&& !node_end_pfn
)
5619 /* Get the start and end of the zone */
5620 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5621 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5622 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5623 node_start_pfn
, node_end_pfn
,
5624 zone_start_pfn
, zone_end_pfn
);
5626 /* Check that this node has pages within the zone's required range */
5627 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5630 /* Move the zone boundaries inside the node if necessary */
5631 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5632 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5634 /* Return the spanned pages */
5635 return *zone_end_pfn
- *zone_start_pfn
;
5639 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5640 * then all holes in the requested range will be accounted for.
5642 unsigned long __meminit
__absent_pages_in_range(int nid
,
5643 unsigned long range_start_pfn
,
5644 unsigned long range_end_pfn
)
5646 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5647 unsigned long start_pfn
, end_pfn
;
5650 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5651 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5652 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5653 nr_absent
-= end_pfn
- start_pfn
;
5659 * absent_pages_in_range - Return number of page frames in holes within a range
5660 * @start_pfn: The start PFN to start searching for holes
5661 * @end_pfn: The end PFN to stop searching for holes
5663 * It returns the number of pages frames in memory holes within a range.
5665 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5666 unsigned long end_pfn
)
5668 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5671 /* Return the number of page frames in holes in a zone on a node */
5672 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5673 unsigned long zone_type
,
5674 unsigned long node_start_pfn
,
5675 unsigned long node_end_pfn
,
5676 unsigned long *ignored
)
5678 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5679 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5680 unsigned long zone_start_pfn
, zone_end_pfn
;
5681 unsigned long nr_absent
;
5683 /* When hotadd a new node from cpu_up(), the node should be empty */
5684 if (!node_start_pfn
&& !node_end_pfn
)
5687 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5688 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5690 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5691 node_start_pfn
, node_end_pfn
,
5692 &zone_start_pfn
, &zone_end_pfn
);
5693 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5696 * ZONE_MOVABLE handling.
5697 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5700 if (zone_movable_pfn
[nid
]) {
5701 if (mirrored_kernelcore
) {
5702 unsigned long start_pfn
, end_pfn
;
5703 struct memblock_region
*r
;
5705 for_each_memblock(memory
, r
) {
5706 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5707 zone_start_pfn
, zone_end_pfn
);
5708 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5709 zone_start_pfn
, zone_end_pfn
);
5711 if (zone_type
== ZONE_MOVABLE
&&
5712 memblock_is_mirror(r
))
5713 nr_absent
+= end_pfn
- start_pfn
;
5715 if (zone_type
== ZONE_NORMAL
&&
5716 !memblock_is_mirror(r
))
5717 nr_absent
+= end_pfn
- start_pfn
;
5720 if (zone_type
== ZONE_NORMAL
)
5721 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5728 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5729 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5730 unsigned long zone_type
,
5731 unsigned long node_start_pfn
,
5732 unsigned long node_end_pfn
,
5733 unsigned long *zone_start_pfn
,
5734 unsigned long *zone_end_pfn
,
5735 unsigned long *zones_size
)
5739 *zone_start_pfn
= node_start_pfn
;
5740 for (zone
= 0; zone
< zone_type
; zone
++)
5741 *zone_start_pfn
+= zones_size
[zone
];
5743 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5745 return zones_size
[zone_type
];
5748 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5749 unsigned long zone_type
,
5750 unsigned long node_start_pfn
,
5751 unsigned long node_end_pfn
,
5752 unsigned long *zholes_size
)
5757 return zholes_size
[zone_type
];
5760 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5762 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5763 unsigned long node_start_pfn
,
5764 unsigned long node_end_pfn
,
5765 unsigned long *zones_size
,
5766 unsigned long *zholes_size
)
5768 unsigned long realtotalpages
= 0, totalpages
= 0;
5771 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5772 struct zone
*zone
= pgdat
->node_zones
+ i
;
5773 unsigned long zone_start_pfn
, zone_end_pfn
;
5774 unsigned long size
, real_size
;
5776 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5782 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5783 node_start_pfn
, node_end_pfn
,
5786 zone
->zone_start_pfn
= zone_start_pfn
;
5788 zone
->zone_start_pfn
= 0;
5789 zone
->spanned_pages
= size
;
5790 zone
->present_pages
= real_size
;
5793 realtotalpages
+= real_size
;
5796 pgdat
->node_spanned_pages
= totalpages
;
5797 pgdat
->node_present_pages
= realtotalpages
;
5798 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5802 #ifndef CONFIG_SPARSEMEM
5804 * Calculate the size of the zone->blockflags rounded to an unsigned long
5805 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5806 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5807 * round what is now in bits to nearest long in bits, then return it in
5810 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5812 unsigned long usemapsize
;
5814 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5815 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5816 usemapsize
= usemapsize
>> pageblock_order
;
5817 usemapsize
*= NR_PAGEBLOCK_BITS
;
5818 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5820 return usemapsize
/ 8;
5823 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5825 unsigned long zone_start_pfn
,
5826 unsigned long zonesize
)
5828 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5829 zone
->pageblock_flags
= NULL
;
5831 zone
->pageblock_flags
=
5832 memblock_virt_alloc_node_nopanic(usemapsize
,
5836 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5837 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5838 #endif /* CONFIG_SPARSEMEM */
5840 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5842 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5843 void __paginginit
set_pageblock_order(void)
5847 /* Check that pageblock_nr_pages has not already been setup */
5848 if (pageblock_order
)
5851 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5852 order
= HUGETLB_PAGE_ORDER
;
5854 order
= MAX_ORDER
- 1;
5857 * Assume the largest contiguous order of interest is a huge page.
5858 * This value may be variable depending on boot parameters on IA64 and
5861 pageblock_order
= order
;
5863 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5866 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5867 * is unused as pageblock_order is set at compile-time. See
5868 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5871 void __paginginit
set_pageblock_order(void)
5875 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5877 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5878 unsigned long present_pages
)
5880 unsigned long pages
= spanned_pages
;
5883 * Provide a more accurate estimation if there are holes within
5884 * the zone and SPARSEMEM is in use. If there are holes within the
5885 * zone, each populated memory region may cost us one or two extra
5886 * memmap pages due to alignment because memmap pages for each
5887 * populated regions may not naturally algined on page boundary.
5888 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5890 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5891 IS_ENABLED(CONFIG_SPARSEMEM
))
5892 pages
= present_pages
;
5894 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5898 * Set up the zone data structures:
5899 * - mark all pages reserved
5900 * - mark all memory queues empty
5901 * - clear the memory bitmaps
5903 * NOTE: pgdat should get zeroed by caller.
5905 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5908 int nid
= pgdat
->node_id
;
5911 pgdat_resize_init(pgdat
);
5912 #ifdef CONFIG_NUMA_BALANCING
5913 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5914 pgdat
->numabalancing_migrate_nr_pages
= 0;
5915 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5917 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5918 spin_lock_init(&pgdat
->split_queue_lock
);
5919 INIT_LIST_HEAD(&pgdat
->split_queue
);
5920 pgdat
->split_queue_len
= 0;
5922 init_waitqueue_head(&pgdat
->kswapd_wait
);
5923 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5924 #ifdef CONFIG_COMPACTION
5925 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5927 pgdat_page_ext_init(pgdat
);
5929 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5930 struct zone
*zone
= pgdat
->node_zones
+ j
;
5931 unsigned long size
, realsize
, freesize
, memmap_pages
;
5932 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5934 size
= zone
->spanned_pages
;
5935 realsize
= freesize
= zone
->present_pages
;
5938 * Adjust freesize so that it accounts for how much memory
5939 * is used by this zone for memmap. This affects the watermark
5940 * and per-cpu initialisations
5942 memmap_pages
= calc_memmap_size(size
, realsize
);
5943 if (!is_highmem_idx(j
)) {
5944 if (freesize
>= memmap_pages
) {
5945 freesize
-= memmap_pages
;
5948 " %s zone: %lu pages used for memmap\n",
5949 zone_names
[j
], memmap_pages
);
5951 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5952 zone_names
[j
], memmap_pages
, freesize
);
5955 /* Account for reserved pages */
5956 if (j
== 0 && freesize
> dma_reserve
) {
5957 freesize
-= dma_reserve
;
5958 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5959 zone_names
[0], dma_reserve
);
5962 if (!is_highmem_idx(j
))
5963 nr_kernel_pages
+= freesize
;
5964 /* Charge for highmem memmap if there are enough kernel pages */
5965 else if (nr_kernel_pages
> memmap_pages
* 2)
5966 nr_kernel_pages
-= memmap_pages
;
5967 nr_all_pages
+= freesize
;
5970 * Set an approximate value for lowmem here, it will be adjusted
5971 * when the bootmem allocator frees pages into the buddy system.
5972 * And all highmem pages will be managed by the buddy system.
5974 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5977 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5979 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5981 zone
->name
= zone_names
[j
];
5982 spin_lock_init(&zone
->lock
);
5983 spin_lock_init(&zone
->lru_lock
);
5984 zone_seqlock_init(zone
);
5985 zone
->zone_pgdat
= pgdat
;
5986 zone_pcp_init(zone
);
5988 /* For bootup, initialized properly in watermark setup */
5989 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5991 lruvec_init(&zone
->lruvec
);
5995 set_pageblock_order();
5996 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5997 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5999 memmap_init(size
, nid
, j
, zone_start_pfn
);
6003 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
6005 unsigned long __maybe_unused start
= 0;
6006 unsigned long __maybe_unused offset
= 0;
6008 /* Skip empty nodes */
6009 if (!pgdat
->node_spanned_pages
)
6012 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6013 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6014 offset
= pgdat
->node_start_pfn
- start
;
6015 /* ia64 gets its own node_mem_map, before this, without bootmem */
6016 if (!pgdat
->node_mem_map
) {
6017 unsigned long size
, end
;
6021 * The zone's endpoints aren't required to be MAX_ORDER
6022 * aligned but the node_mem_map endpoints must be in order
6023 * for the buddy allocator to function correctly.
6025 end
= pgdat_end_pfn(pgdat
);
6026 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6027 size
= (end
- start
) * sizeof(struct page
);
6028 map
= alloc_remap(pgdat
->node_id
, size
);
6030 map
= memblock_virt_alloc_node_nopanic(size
,
6032 pgdat
->node_mem_map
= map
+ offset
;
6034 #ifndef CONFIG_NEED_MULTIPLE_NODES
6036 * With no DISCONTIG, the global mem_map is just set as node 0's
6038 if (pgdat
== NODE_DATA(0)) {
6039 mem_map
= NODE_DATA(0)->node_mem_map
;
6040 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6041 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6043 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6046 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6049 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6050 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6052 pg_data_t
*pgdat
= NODE_DATA(nid
);
6053 unsigned long start_pfn
= 0;
6054 unsigned long end_pfn
= 0;
6056 /* pg_data_t should be reset to zero when it's allocated */
6057 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
6059 reset_deferred_meminit(pgdat
);
6060 pgdat
->node_id
= nid
;
6061 pgdat
->node_start_pfn
= node_start_pfn
;
6062 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6063 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6064 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6065 (u64
)start_pfn
<< PAGE_SHIFT
,
6066 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6068 start_pfn
= node_start_pfn
;
6070 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6071 zones_size
, zholes_size
);
6073 alloc_node_mem_map(pgdat
);
6074 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6075 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6076 nid
, (unsigned long)pgdat
,
6077 (unsigned long)pgdat
->node_mem_map
);
6080 free_area_init_core(pgdat
);
6083 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6085 #if MAX_NUMNODES > 1
6087 * Figure out the number of possible node ids.
6089 void __init
setup_nr_node_ids(void)
6091 unsigned int highest
;
6093 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6094 nr_node_ids
= highest
+ 1;
6099 * node_map_pfn_alignment - determine the maximum internode alignment
6101 * This function should be called after node map is populated and sorted.
6102 * It calculates the maximum power of two alignment which can distinguish
6105 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6106 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6107 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6108 * shifted, 1GiB is enough and this function will indicate so.
6110 * This is used to test whether pfn -> nid mapping of the chosen memory
6111 * model has fine enough granularity to avoid incorrect mapping for the
6112 * populated node map.
6114 * Returns the determined alignment in pfn's. 0 if there is no alignment
6115 * requirement (single node).
6117 unsigned long __init
node_map_pfn_alignment(void)
6119 unsigned long accl_mask
= 0, last_end
= 0;
6120 unsigned long start
, end
, mask
;
6124 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6125 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6132 * Start with a mask granular enough to pin-point to the
6133 * start pfn and tick off bits one-by-one until it becomes
6134 * too coarse to separate the current node from the last.
6136 mask
= ~((1 << __ffs(start
)) - 1);
6137 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6140 /* accumulate all internode masks */
6144 /* convert mask to number of pages */
6145 return ~accl_mask
+ 1;
6148 /* Find the lowest pfn for a node */
6149 static unsigned long __init
find_min_pfn_for_node(int nid
)
6151 unsigned long min_pfn
= ULONG_MAX
;
6152 unsigned long start_pfn
;
6155 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6156 min_pfn
= min(min_pfn
, start_pfn
);
6158 if (min_pfn
== ULONG_MAX
) {
6159 pr_warn("Could not find start_pfn for node %d\n", nid
);
6167 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6169 * It returns the minimum PFN based on information provided via
6170 * memblock_set_node().
6172 unsigned long __init
find_min_pfn_with_active_regions(void)
6174 return find_min_pfn_for_node(MAX_NUMNODES
);
6178 * early_calculate_totalpages()
6179 * Sum pages in active regions for movable zone.
6180 * Populate N_MEMORY for calculating usable_nodes.
6182 static unsigned long __init
early_calculate_totalpages(void)
6184 unsigned long totalpages
= 0;
6185 unsigned long start_pfn
, end_pfn
;
6188 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6189 unsigned long pages
= end_pfn
- start_pfn
;
6191 totalpages
+= pages
;
6193 node_set_state(nid
, N_MEMORY
);
6199 * Find the PFN the Movable zone begins in each node. Kernel memory
6200 * is spread evenly between nodes as long as the nodes have enough
6201 * memory. When they don't, some nodes will have more kernelcore than
6204 static void __init
find_zone_movable_pfns_for_nodes(void)
6207 unsigned long usable_startpfn
;
6208 unsigned long kernelcore_node
, kernelcore_remaining
;
6209 /* save the state before borrow the nodemask */
6210 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6211 unsigned long totalpages
= early_calculate_totalpages();
6212 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6213 struct memblock_region
*r
;
6215 /* Need to find movable_zone earlier when movable_node is specified. */
6216 find_usable_zone_for_movable();
6219 * If movable_node is specified, ignore kernelcore and movablecore
6222 if (movable_node_is_enabled()) {
6223 for_each_memblock(memory
, r
) {
6224 if (!memblock_is_hotpluggable(r
))
6229 usable_startpfn
= PFN_DOWN(r
->base
);
6230 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6231 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6239 * If kernelcore=mirror is specified, ignore movablecore option
6241 if (mirrored_kernelcore
) {
6242 bool mem_below_4gb_not_mirrored
= false;
6244 for_each_memblock(memory
, r
) {
6245 if (memblock_is_mirror(r
))
6250 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6252 if (usable_startpfn
< 0x100000) {
6253 mem_below_4gb_not_mirrored
= true;
6257 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6258 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6262 if (mem_below_4gb_not_mirrored
)
6263 pr_warn("This configuration results in unmirrored kernel memory.");
6269 * If movablecore=nn[KMG] was specified, calculate what size of
6270 * kernelcore that corresponds so that memory usable for
6271 * any allocation type is evenly spread. If both kernelcore
6272 * and movablecore are specified, then the value of kernelcore
6273 * will be used for required_kernelcore if it's greater than
6274 * what movablecore would have allowed.
6276 if (required_movablecore
) {
6277 unsigned long corepages
;
6280 * Round-up so that ZONE_MOVABLE is at least as large as what
6281 * was requested by the user
6283 required_movablecore
=
6284 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6285 required_movablecore
= min(totalpages
, required_movablecore
);
6286 corepages
= totalpages
- required_movablecore
;
6288 required_kernelcore
= max(required_kernelcore
, corepages
);
6292 * If kernelcore was not specified or kernelcore size is larger
6293 * than totalpages, there is no ZONE_MOVABLE.
6295 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6298 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6299 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6302 /* Spread kernelcore memory as evenly as possible throughout nodes */
6303 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6304 for_each_node_state(nid
, N_MEMORY
) {
6305 unsigned long start_pfn
, end_pfn
;
6308 * Recalculate kernelcore_node if the division per node
6309 * now exceeds what is necessary to satisfy the requested
6310 * amount of memory for the kernel
6312 if (required_kernelcore
< kernelcore_node
)
6313 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6316 * As the map is walked, we track how much memory is usable
6317 * by the kernel using kernelcore_remaining. When it is
6318 * 0, the rest of the node is usable by ZONE_MOVABLE
6320 kernelcore_remaining
= kernelcore_node
;
6322 /* Go through each range of PFNs within this node */
6323 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6324 unsigned long size_pages
;
6326 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6327 if (start_pfn
>= end_pfn
)
6330 /* Account for what is only usable for kernelcore */
6331 if (start_pfn
< usable_startpfn
) {
6332 unsigned long kernel_pages
;
6333 kernel_pages
= min(end_pfn
, usable_startpfn
)
6336 kernelcore_remaining
-= min(kernel_pages
,
6337 kernelcore_remaining
);
6338 required_kernelcore
-= min(kernel_pages
,
6339 required_kernelcore
);
6341 /* Continue if range is now fully accounted */
6342 if (end_pfn
<= usable_startpfn
) {
6345 * Push zone_movable_pfn to the end so
6346 * that if we have to rebalance
6347 * kernelcore across nodes, we will
6348 * not double account here
6350 zone_movable_pfn
[nid
] = end_pfn
;
6353 start_pfn
= usable_startpfn
;
6357 * The usable PFN range for ZONE_MOVABLE is from
6358 * start_pfn->end_pfn. Calculate size_pages as the
6359 * number of pages used as kernelcore
6361 size_pages
= end_pfn
- start_pfn
;
6362 if (size_pages
> kernelcore_remaining
)
6363 size_pages
= kernelcore_remaining
;
6364 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6367 * Some kernelcore has been met, update counts and
6368 * break if the kernelcore for this node has been
6371 required_kernelcore
-= min(required_kernelcore
,
6373 kernelcore_remaining
-= size_pages
;
6374 if (!kernelcore_remaining
)
6380 * If there is still required_kernelcore, we do another pass with one
6381 * less node in the count. This will push zone_movable_pfn[nid] further
6382 * along on the nodes that still have memory until kernelcore is
6386 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6390 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6391 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6392 zone_movable_pfn
[nid
] =
6393 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6396 /* restore the node_state */
6397 node_states
[N_MEMORY
] = saved_node_state
;
6400 /* Any regular or high memory on that node ? */
6401 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6403 enum zone_type zone_type
;
6405 if (N_MEMORY
== N_NORMAL_MEMORY
)
6408 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6409 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6410 if (populated_zone(zone
)) {
6411 node_set_state(nid
, N_HIGH_MEMORY
);
6412 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6413 zone_type
<= ZONE_NORMAL
)
6414 node_set_state(nid
, N_NORMAL_MEMORY
);
6421 * free_area_init_nodes - Initialise all pg_data_t and zone data
6422 * @max_zone_pfn: an array of max PFNs for each zone
6424 * This will call free_area_init_node() for each active node in the system.
6425 * Using the page ranges provided by memblock_set_node(), the size of each
6426 * zone in each node and their holes is calculated. If the maximum PFN
6427 * between two adjacent zones match, it is assumed that the zone is empty.
6428 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6429 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6430 * starts where the previous one ended. For example, ZONE_DMA32 starts
6431 * at arch_max_dma_pfn.
6433 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6435 unsigned long start_pfn
, end_pfn
;
6438 /* Record where the zone boundaries are */
6439 memset(arch_zone_lowest_possible_pfn
, 0,
6440 sizeof(arch_zone_lowest_possible_pfn
));
6441 memset(arch_zone_highest_possible_pfn
, 0,
6442 sizeof(arch_zone_highest_possible_pfn
));
6443 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
6444 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
6445 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
6446 if (i
== ZONE_MOVABLE
)
6448 arch_zone_lowest_possible_pfn
[i
] =
6449 arch_zone_highest_possible_pfn
[i
-1];
6450 arch_zone_highest_possible_pfn
[i
] =
6451 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
6453 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
6454 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
6456 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6457 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6458 find_zone_movable_pfns_for_nodes();
6460 /* Print out the zone ranges */
6461 pr_info("Zone ranges:\n");
6462 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6463 if (i
== ZONE_MOVABLE
)
6465 pr_info(" %-8s ", zone_names
[i
]);
6466 if (arch_zone_lowest_possible_pfn
[i
] ==
6467 arch_zone_highest_possible_pfn
[i
])
6470 pr_cont("[mem %#018Lx-%#018Lx]\n",
6471 (u64
)arch_zone_lowest_possible_pfn
[i
]
6473 ((u64
)arch_zone_highest_possible_pfn
[i
]
6474 << PAGE_SHIFT
) - 1);
6477 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6478 pr_info("Movable zone start for each node\n");
6479 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6480 if (zone_movable_pfn
[i
])
6481 pr_info(" Node %d: %#018Lx\n", i
,
6482 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6485 /* Print out the early node map */
6486 pr_info("Early memory node ranges\n");
6487 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6488 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6489 (u64
)start_pfn
<< PAGE_SHIFT
,
6490 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6492 /* Initialise every node */
6493 mminit_verify_pageflags_layout();
6494 setup_nr_node_ids();
6495 for_each_online_node(nid
) {
6496 pg_data_t
*pgdat
= NODE_DATA(nid
);
6497 free_area_init_node(nid
, NULL
,
6498 find_min_pfn_for_node(nid
), NULL
);
6500 /* Any memory on that node */
6501 if (pgdat
->node_present_pages
)
6502 node_set_state(nid
, N_MEMORY
);
6503 check_for_memory(pgdat
, nid
);
6507 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6509 unsigned long long coremem
;
6513 coremem
= memparse(p
, &p
);
6514 *core
= coremem
>> PAGE_SHIFT
;
6516 /* Paranoid check that UL is enough for the coremem value */
6517 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6523 * kernelcore=size sets the amount of memory for use for allocations that
6524 * cannot be reclaimed or migrated.
6526 static int __init
cmdline_parse_kernelcore(char *p
)
6528 /* parse kernelcore=mirror */
6529 if (parse_option_str(p
, "mirror")) {
6530 mirrored_kernelcore
= true;
6534 return cmdline_parse_core(p
, &required_kernelcore
);
6538 * movablecore=size sets the amount of memory for use for allocations that
6539 * can be reclaimed or migrated.
6541 static int __init
cmdline_parse_movablecore(char *p
)
6543 return cmdline_parse_core(p
, &required_movablecore
);
6546 early_param("kernelcore", cmdline_parse_kernelcore
);
6547 early_param("movablecore", cmdline_parse_movablecore
);
6549 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6551 void adjust_managed_page_count(struct page
*page
, long count
)
6553 spin_lock(&managed_page_count_lock
);
6554 page_zone(page
)->managed_pages
+= count
;
6555 totalram_pages
+= count
;
6556 #ifdef CONFIG_HIGHMEM
6557 if (PageHighMem(page
))
6558 totalhigh_pages
+= count
;
6560 spin_unlock(&managed_page_count_lock
);
6562 EXPORT_SYMBOL(adjust_managed_page_count
);
6564 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6567 unsigned long pages
= 0;
6569 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6570 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6571 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6572 if ((unsigned int)poison
<= 0xFF)
6573 memset(pos
, poison
, PAGE_SIZE
);
6574 free_reserved_page(virt_to_page(pos
));
6578 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6579 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6583 EXPORT_SYMBOL(free_reserved_area
);
6585 #ifdef CONFIG_HIGHMEM
6586 void free_highmem_page(struct page
*page
)
6588 __free_reserved_page(page
);
6590 page_zone(page
)->managed_pages
++;
6596 void __init
mem_init_print_info(const char *str
)
6598 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6599 unsigned long init_code_size
, init_data_size
;
6601 physpages
= get_num_physpages();
6602 codesize
= _etext
- _stext
;
6603 datasize
= _edata
- _sdata
;
6604 rosize
= __end_rodata
- __start_rodata
;
6605 bss_size
= __bss_stop
- __bss_start
;
6606 init_data_size
= __init_end
- __init_begin
;
6607 init_code_size
= _einittext
- _sinittext
;
6610 * Detect special cases and adjust section sizes accordingly:
6611 * 1) .init.* may be embedded into .data sections
6612 * 2) .init.text.* may be out of [__init_begin, __init_end],
6613 * please refer to arch/tile/kernel/vmlinux.lds.S.
6614 * 3) .rodata.* may be embedded into .text or .data sections.
6616 #define adj_init_size(start, end, size, pos, adj) \
6618 if (start <= pos && pos < end && size > adj) \
6622 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6623 _sinittext
, init_code_size
);
6624 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6625 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6626 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6627 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6629 #undef adj_init_size
6631 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6632 #ifdef CONFIG_HIGHMEM
6636 nr_free_pages() << (PAGE_SHIFT
- 10),
6637 physpages
<< (PAGE_SHIFT
- 10),
6638 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6639 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6640 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6641 totalcma_pages
<< (PAGE_SHIFT
- 10),
6642 #ifdef CONFIG_HIGHMEM
6643 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6645 str
? ", " : "", str
? str
: "");
6649 * set_dma_reserve - set the specified number of pages reserved in the first zone
6650 * @new_dma_reserve: The number of pages to mark reserved
6652 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6653 * In the DMA zone, a significant percentage may be consumed by kernel image
6654 * and other unfreeable allocations which can skew the watermarks badly. This
6655 * function may optionally be used to account for unfreeable pages in the
6656 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6657 * smaller per-cpu batchsize.
6659 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6661 dma_reserve
= new_dma_reserve
;
6664 void __init
free_area_init(unsigned long *zones_size
)
6666 free_area_init_node(0, zones_size
,
6667 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6670 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6671 unsigned long action
, void *hcpu
)
6673 int cpu
= (unsigned long)hcpu
;
6675 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6676 lru_add_drain_cpu(cpu
);
6680 * Spill the event counters of the dead processor
6681 * into the current processors event counters.
6682 * This artificially elevates the count of the current
6685 vm_events_fold_cpu(cpu
);
6688 * Zero the differential counters of the dead processor
6689 * so that the vm statistics are consistent.
6691 * This is only okay since the processor is dead and cannot
6692 * race with what we are doing.
6694 cpu_vm_stats_fold(cpu
);
6699 void __init
page_alloc_init(void)
6701 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6705 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6706 * or min_free_kbytes changes.
6708 static void calculate_totalreserve_pages(void)
6710 struct pglist_data
*pgdat
;
6711 unsigned long reserve_pages
= 0;
6712 enum zone_type i
, j
;
6714 for_each_online_pgdat(pgdat
) {
6715 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6716 struct zone
*zone
= pgdat
->node_zones
+ i
;
6719 /* Find valid and maximum lowmem_reserve in the zone */
6720 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6721 if (zone
->lowmem_reserve
[j
] > max
)
6722 max
= zone
->lowmem_reserve
[j
];
6725 /* we treat the high watermark as reserved pages. */
6726 max
+= high_wmark_pages(zone
);
6728 if (max
> zone
->managed_pages
)
6729 max
= zone
->managed_pages
;
6731 zone
->totalreserve_pages
= max
;
6733 reserve_pages
+= max
;
6736 totalreserve_pages
= reserve_pages
;
6740 * setup_per_zone_lowmem_reserve - called whenever
6741 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6742 * has a correct pages reserved value, so an adequate number of
6743 * pages are left in the zone after a successful __alloc_pages().
6745 static void setup_per_zone_lowmem_reserve(void)
6747 struct pglist_data
*pgdat
;
6748 enum zone_type j
, idx
;
6750 for_each_online_pgdat(pgdat
) {
6751 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6752 struct zone
*zone
= pgdat
->node_zones
+ j
;
6753 unsigned long managed_pages
= zone
->managed_pages
;
6755 zone
->lowmem_reserve
[j
] = 0;
6759 struct zone
*lower_zone
;
6763 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6764 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6766 lower_zone
= pgdat
->node_zones
+ idx
;
6767 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6768 sysctl_lowmem_reserve_ratio
[idx
];
6769 managed_pages
+= lower_zone
->managed_pages
;
6774 /* update totalreserve_pages */
6775 calculate_totalreserve_pages();
6778 static void __setup_per_zone_wmarks(void)
6780 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6781 unsigned long lowmem_pages
= 0;
6783 unsigned long flags
;
6785 /* Calculate total number of !ZONE_HIGHMEM pages */
6786 for_each_zone(zone
) {
6787 if (!is_highmem(zone
))
6788 lowmem_pages
+= zone
->managed_pages
;
6791 for_each_zone(zone
) {
6794 spin_lock_irqsave(&zone
->lock
, flags
);
6795 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6796 do_div(tmp
, lowmem_pages
);
6797 if (is_highmem(zone
)) {
6799 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6800 * need highmem pages, so cap pages_min to a small
6803 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6804 * deltas control asynch page reclaim, and so should
6805 * not be capped for highmem.
6807 unsigned long min_pages
;
6809 min_pages
= zone
->managed_pages
/ 1024;
6810 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6811 zone
->watermark
[WMARK_MIN
] = min_pages
;
6814 * If it's a lowmem zone, reserve a number of pages
6815 * proportionate to the zone's size.
6817 zone
->watermark
[WMARK_MIN
] = tmp
;
6821 * Set the kswapd watermarks distance according to the
6822 * scale factor in proportion to available memory, but
6823 * ensure a minimum size on small systems.
6825 tmp
= max_t(u64
, tmp
>> 2,
6826 mult_frac(zone
->managed_pages
,
6827 watermark_scale_factor
, 10000));
6829 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6830 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6832 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6833 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6834 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6836 spin_unlock_irqrestore(&zone
->lock
, flags
);
6839 /* update totalreserve_pages */
6840 calculate_totalreserve_pages();
6844 * setup_per_zone_wmarks - called when min_free_kbytes changes
6845 * or when memory is hot-{added|removed}
6847 * Ensures that the watermark[min,low,high] values for each zone are set
6848 * correctly with respect to min_free_kbytes.
6850 void setup_per_zone_wmarks(void)
6852 mutex_lock(&zonelists_mutex
);
6853 __setup_per_zone_wmarks();
6854 mutex_unlock(&zonelists_mutex
);
6858 * Initialise min_free_kbytes.
6860 * For small machines we want it small (128k min). For large machines
6861 * we want it large (64MB max). But it is not linear, because network
6862 * bandwidth does not increase linearly with machine size. We use
6864 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6865 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6881 int __meminit
init_per_zone_wmark_min(void)
6883 unsigned long lowmem_kbytes
;
6884 int new_min_free_kbytes
;
6886 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6887 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6889 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6890 min_free_kbytes
= new_min_free_kbytes
;
6891 if (min_free_kbytes
< 128)
6892 min_free_kbytes
= 128;
6893 if (min_free_kbytes
> 65536)
6894 min_free_kbytes
= 65536;
6896 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6897 new_min_free_kbytes
, user_min_free_kbytes
);
6899 setup_per_zone_wmarks();
6900 refresh_zone_stat_thresholds();
6901 setup_per_zone_lowmem_reserve();
6904 core_initcall(init_per_zone_wmark_min
)
6907 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6908 * that we can call two helper functions whenever min_free_kbytes
6911 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6912 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6916 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6921 user_min_free_kbytes
= min_free_kbytes
;
6922 setup_per_zone_wmarks();
6927 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6928 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6932 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6937 setup_per_zone_wmarks();
6943 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6944 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6949 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6954 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6955 sysctl_min_unmapped_ratio
) / 100;
6959 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6960 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6965 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6970 zone
->min_slab_pages
= (zone
->managed_pages
*
6971 sysctl_min_slab_ratio
) / 100;
6977 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6978 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6979 * whenever sysctl_lowmem_reserve_ratio changes.
6981 * The reserve ratio obviously has absolutely no relation with the
6982 * minimum watermarks. The lowmem reserve ratio can only make sense
6983 * if in function of the boot time zone sizes.
6985 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6986 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6988 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6989 setup_per_zone_lowmem_reserve();
6994 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6995 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6996 * pagelist can have before it gets flushed back to buddy allocator.
6998 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6999 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7002 int old_percpu_pagelist_fraction
;
7005 mutex_lock(&pcp_batch_high_lock
);
7006 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7008 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7009 if (!write
|| ret
< 0)
7012 /* Sanity checking to avoid pcp imbalance */
7013 if (percpu_pagelist_fraction
&&
7014 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7015 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7021 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7024 for_each_populated_zone(zone
) {
7027 for_each_possible_cpu(cpu
)
7028 pageset_set_high_and_batch(zone
,
7029 per_cpu_ptr(zone
->pageset
, cpu
));
7032 mutex_unlock(&pcp_batch_high_lock
);
7037 int hashdist
= HASHDIST_DEFAULT
;
7039 static int __init
set_hashdist(char *str
)
7043 hashdist
= simple_strtoul(str
, &str
, 0);
7046 __setup("hashdist=", set_hashdist
);
7050 * allocate a large system hash table from bootmem
7051 * - it is assumed that the hash table must contain an exact power-of-2
7052 * quantity of entries
7053 * - limit is the number of hash buckets, not the total allocation size
7055 void *__init
alloc_large_system_hash(const char *tablename
,
7056 unsigned long bucketsize
,
7057 unsigned long numentries
,
7060 unsigned int *_hash_shift
,
7061 unsigned int *_hash_mask
,
7062 unsigned long low_limit
,
7063 unsigned long high_limit
)
7065 unsigned long long max
= high_limit
;
7066 unsigned long log2qty
, size
;
7069 /* allow the kernel cmdline to have a say */
7071 /* round applicable memory size up to nearest megabyte */
7072 numentries
= nr_kernel_pages
;
7074 /* It isn't necessary when PAGE_SIZE >= 1MB */
7075 if (PAGE_SHIFT
< 20)
7076 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7078 /* limit to 1 bucket per 2^scale bytes of low memory */
7079 if (scale
> PAGE_SHIFT
)
7080 numentries
>>= (scale
- PAGE_SHIFT
);
7082 numentries
<<= (PAGE_SHIFT
- scale
);
7084 /* Make sure we've got at least a 0-order allocation.. */
7085 if (unlikely(flags
& HASH_SMALL
)) {
7086 /* Makes no sense without HASH_EARLY */
7087 WARN_ON(!(flags
& HASH_EARLY
));
7088 if (!(numentries
>> *_hash_shift
)) {
7089 numentries
= 1UL << *_hash_shift
;
7090 BUG_ON(!numentries
);
7092 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7093 numentries
= PAGE_SIZE
/ bucketsize
;
7095 numentries
= roundup_pow_of_two(numentries
);
7097 /* limit allocation size to 1/16 total memory by default */
7099 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7100 do_div(max
, bucketsize
);
7102 max
= min(max
, 0x80000000ULL
);
7104 if (numentries
< low_limit
)
7105 numentries
= low_limit
;
7106 if (numentries
> max
)
7109 log2qty
= ilog2(numentries
);
7112 size
= bucketsize
<< log2qty
;
7113 if (flags
& HASH_EARLY
)
7114 table
= memblock_virt_alloc_nopanic(size
, 0);
7116 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
7119 * If bucketsize is not a power-of-two, we may free
7120 * some pages at the end of hash table which
7121 * alloc_pages_exact() automatically does
7123 if (get_order(size
) < MAX_ORDER
) {
7124 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
7125 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
7128 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7131 panic("Failed to allocate %s hash table\n", tablename
);
7133 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7134 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7137 *_hash_shift
= log2qty
;
7139 *_hash_mask
= (1 << log2qty
) - 1;
7145 * This function checks whether pageblock includes unmovable pages or not.
7146 * If @count is not zero, it is okay to include less @count unmovable pages
7148 * PageLRU check without isolation or lru_lock could race so that
7149 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7150 * expect this function should be exact.
7152 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7153 bool skip_hwpoisoned_pages
)
7155 unsigned long pfn
, iter
, found
;
7159 * For avoiding noise data, lru_add_drain_all() should be called
7160 * If ZONE_MOVABLE, the zone never contains unmovable pages
7162 if (zone_idx(zone
) == ZONE_MOVABLE
)
7164 mt
= get_pageblock_migratetype(page
);
7165 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7168 pfn
= page_to_pfn(page
);
7169 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7170 unsigned long check
= pfn
+ iter
;
7172 if (!pfn_valid_within(check
))
7175 page
= pfn_to_page(check
);
7178 * Hugepages are not in LRU lists, but they're movable.
7179 * We need not scan over tail pages bacause we don't
7180 * handle each tail page individually in migration.
7182 if (PageHuge(page
)) {
7183 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7188 * We can't use page_count without pin a page
7189 * because another CPU can free compound page.
7190 * This check already skips compound tails of THP
7191 * because their page->_refcount is zero at all time.
7193 if (!page_ref_count(page
)) {
7194 if (PageBuddy(page
))
7195 iter
+= (1 << page_order(page
)) - 1;
7200 * The HWPoisoned page may be not in buddy system, and
7201 * page_count() is not 0.
7203 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7209 * If there are RECLAIMABLE pages, we need to check
7210 * it. But now, memory offline itself doesn't call
7211 * shrink_node_slabs() and it still to be fixed.
7214 * If the page is not RAM, page_count()should be 0.
7215 * we don't need more check. This is an _used_ not-movable page.
7217 * The problematic thing here is PG_reserved pages. PG_reserved
7218 * is set to both of a memory hole page and a _used_ kernel
7227 bool is_pageblock_removable_nolock(struct page
*page
)
7233 * We have to be careful here because we are iterating over memory
7234 * sections which are not zone aware so we might end up outside of
7235 * the zone but still within the section.
7236 * We have to take care about the node as well. If the node is offline
7237 * its NODE_DATA will be NULL - see page_zone.
7239 if (!node_online(page_to_nid(page
)))
7242 zone
= page_zone(page
);
7243 pfn
= page_to_pfn(page
);
7244 if (!zone_spans_pfn(zone
, pfn
))
7247 return !has_unmovable_pages(zone
, page
, 0, true);
7250 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7252 static unsigned long pfn_max_align_down(unsigned long pfn
)
7254 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7255 pageblock_nr_pages
) - 1);
7258 static unsigned long pfn_max_align_up(unsigned long pfn
)
7260 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7261 pageblock_nr_pages
));
7264 /* [start, end) must belong to a single zone. */
7265 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7266 unsigned long start
, unsigned long end
)
7268 /* This function is based on compact_zone() from compaction.c. */
7269 unsigned long nr_reclaimed
;
7270 unsigned long pfn
= start
;
7271 unsigned int tries
= 0;
7276 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7277 if (fatal_signal_pending(current
)) {
7282 if (list_empty(&cc
->migratepages
)) {
7283 cc
->nr_migratepages
= 0;
7284 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7290 } else if (++tries
== 5) {
7291 ret
= ret
< 0 ? ret
: -EBUSY
;
7295 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7297 cc
->nr_migratepages
-= nr_reclaimed
;
7299 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7300 NULL
, 0, cc
->mode
, MR_CMA
);
7303 putback_movable_pages(&cc
->migratepages
);
7310 * alloc_contig_range() -- tries to allocate given range of pages
7311 * @start: start PFN to allocate
7312 * @end: one-past-the-last PFN to allocate
7313 * @migratetype: migratetype of the underlaying pageblocks (either
7314 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7315 * in range must have the same migratetype and it must
7316 * be either of the two.
7318 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7319 * aligned, however it's the caller's responsibility to guarantee that
7320 * we are the only thread that changes migrate type of pageblocks the
7323 * The PFN range must belong to a single zone.
7325 * Returns zero on success or negative error code. On success all
7326 * pages which PFN is in [start, end) are allocated for the caller and
7327 * need to be freed with free_contig_range().
7329 int alloc_contig_range(unsigned long start
, unsigned long end
,
7330 unsigned migratetype
)
7332 unsigned long outer_start
, outer_end
;
7336 struct compact_control cc
= {
7337 .nr_migratepages
= 0,
7339 .zone
= page_zone(pfn_to_page(start
)),
7340 .mode
= MIGRATE_SYNC
,
7341 .ignore_skip_hint
= true,
7343 INIT_LIST_HEAD(&cc
.migratepages
);
7346 * What we do here is we mark all pageblocks in range as
7347 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7348 * have different sizes, and due to the way page allocator
7349 * work, we align the range to biggest of the two pages so
7350 * that page allocator won't try to merge buddies from
7351 * different pageblocks and change MIGRATE_ISOLATE to some
7352 * other migration type.
7354 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7355 * migrate the pages from an unaligned range (ie. pages that
7356 * we are interested in). This will put all the pages in
7357 * range back to page allocator as MIGRATE_ISOLATE.
7359 * When this is done, we take the pages in range from page
7360 * allocator removing them from the buddy system. This way
7361 * page allocator will never consider using them.
7363 * This lets us mark the pageblocks back as
7364 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7365 * aligned range but not in the unaligned, original range are
7366 * put back to page allocator so that buddy can use them.
7369 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7370 pfn_max_align_up(end
), migratetype
,
7376 * In case of -EBUSY, we'd like to know which page causes problem.
7377 * So, just fall through. We will check it in test_pages_isolated().
7379 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7380 if (ret
&& ret
!= -EBUSY
)
7384 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7385 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7386 * more, all pages in [start, end) are free in page allocator.
7387 * What we are going to do is to allocate all pages from
7388 * [start, end) (that is remove them from page allocator).
7390 * The only problem is that pages at the beginning and at the
7391 * end of interesting range may be not aligned with pages that
7392 * page allocator holds, ie. they can be part of higher order
7393 * pages. Because of this, we reserve the bigger range and
7394 * once this is done free the pages we are not interested in.
7396 * We don't have to hold zone->lock here because the pages are
7397 * isolated thus they won't get removed from buddy.
7400 lru_add_drain_all();
7401 drain_all_pages(cc
.zone
);
7404 outer_start
= start
;
7405 while (!PageBuddy(pfn_to_page(outer_start
))) {
7406 if (++order
>= MAX_ORDER
) {
7407 outer_start
= start
;
7410 outer_start
&= ~0UL << order
;
7413 if (outer_start
!= start
) {
7414 order
= page_order(pfn_to_page(outer_start
));
7417 * outer_start page could be small order buddy page and
7418 * it doesn't include start page. Adjust outer_start
7419 * in this case to report failed page properly
7420 * on tracepoint in test_pages_isolated()
7422 if (outer_start
+ (1UL << order
) <= start
)
7423 outer_start
= start
;
7426 /* Make sure the range is really isolated. */
7427 if (test_pages_isolated(outer_start
, end
, false)) {
7428 pr_info("%s: [%lx, %lx) PFNs busy\n",
7429 __func__
, outer_start
, end
);
7434 /* Grab isolated pages from freelists. */
7435 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7441 /* Free head and tail (if any) */
7442 if (start
!= outer_start
)
7443 free_contig_range(outer_start
, start
- outer_start
);
7444 if (end
!= outer_end
)
7445 free_contig_range(end
, outer_end
- end
);
7448 undo_isolate_page_range(pfn_max_align_down(start
),
7449 pfn_max_align_up(end
), migratetype
);
7453 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7455 unsigned int count
= 0;
7457 for (; nr_pages
--; pfn
++) {
7458 struct page
*page
= pfn_to_page(pfn
);
7460 count
+= page_count(page
) != 1;
7463 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7467 #ifdef CONFIG_MEMORY_HOTPLUG
7469 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7470 * page high values need to be recalulated.
7472 void __meminit
zone_pcp_update(struct zone
*zone
)
7475 mutex_lock(&pcp_batch_high_lock
);
7476 for_each_possible_cpu(cpu
)
7477 pageset_set_high_and_batch(zone
,
7478 per_cpu_ptr(zone
->pageset
, cpu
));
7479 mutex_unlock(&pcp_batch_high_lock
);
7483 void zone_pcp_reset(struct zone
*zone
)
7485 unsigned long flags
;
7487 struct per_cpu_pageset
*pset
;
7489 /* avoid races with drain_pages() */
7490 local_irq_save(flags
);
7491 if (zone
->pageset
!= &boot_pageset
) {
7492 for_each_online_cpu(cpu
) {
7493 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7494 drain_zonestat(zone
, pset
);
7496 free_percpu(zone
->pageset
);
7497 zone
->pageset
= &boot_pageset
;
7499 local_irq_restore(flags
);
7502 #ifdef CONFIG_MEMORY_HOTREMOVE
7504 * All pages in the range must be in a single zone and isolated
7505 * before calling this.
7508 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7512 unsigned int order
, i
;
7514 unsigned long flags
;
7515 /* find the first valid pfn */
7516 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7521 zone
= page_zone(pfn_to_page(pfn
));
7522 spin_lock_irqsave(&zone
->lock
, flags
);
7524 while (pfn
< end_pfn
) {
7525 if (!pfn_valid(pfn
)) {
7529 page
= pfn_to_page(pfn
);
7531 * The HWPoisoned page may be not in buddy system, and
7532 * page_count() is not 0.
7534 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7536 SetPageReserved(page
);
7540 BUG_ON(page_count(page
));
7541 BUG_ON(!PageBuddy(page
));
7542 order
= page_order(page
);
7543 #ifdef CONFIG_DEBUG_VM
7544 pr_info("remove from free list %lx %d %lx\n",
7545 pfn
, 1 << order
, end_pfn
);
7547 list_del(&page
->lru
);
7548 rmv_page_order(page
);
7549 zone
->free_area
[order
].nr_free
--;
7550 for (i
= 0; i
< (1 << order
); i
++)
7551 SetPageReserved((page
+i
));
7552 pfn
+= (1 << order
);
7554 spin_unlock_irqrestore(&zone
->lock
, flags
);
7558 bool is_free_buddy_page(struct page
*page
)
7560 struct zone
*zone
= page_zone(page
);
7561 unsigned long pfn
= page_to_pfn(page
);
7562 unsigned long flags
;
7565 spin_lock_irqsave(&zone
->lock
, flags
);
7566 for (order
= 0; order
< MAX_ORDER
; order
++) {
7567 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7569 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7572 spin_unlock_irqrestore(&zone
->lock
, flags
);
7574 return order
< MAX_ORDER
;