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>
66 #include <linux/memcontrol.h>
68 #include <asm/sections.h>
69 #include <asm/tlbflush.h>
70 #include <asm/div64.h>
73 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
74 static DEFINE_MUTEX(pcp_batch_high_lock
);
75 #define MIN_PERCPU_PAGELIST_FRACTION (8)
77 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
78 DEFINE_PER_CPU(int, numa_node
);
79 EXPORT_PER_CPU_SYMBOL(numa_node
);
82 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
84 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
85 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
86 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
87 * defined in <linux/topology.h>.
89 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
90 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
91 int _node_numa_mem_
[MAX_NUMNODES
];
95 * Array of node states.
97 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
98 [N_POSSIBLE
] = NODE_MASK_ALL
,
99 [N_ONLINE
] = { { [0] = 1UL } },
101 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
102 #ifdef CONFIG_HIGHMEM
103 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
105 #ifdef CONFIG_MOVABLE_NODE
106 [N_MEMORY
] = { { [0] = 1UL } },
108 [N_CPU
] = { { [0] = 1UL } },
111 EXPORT_SYMBOL(node_states
);
113 /* Protect totalram_pages and zone->managed_pages */
114 static DEFINE_SPINLOCK(managed_page_count_lock
);
116 unsigned long totalram_pages __read_mostly
;
117 unsigned long totalreserve_pages __read_mostly
;
118 unsigned long totalcma_pages __read_mostly
;
120 int percpu_pagelist_fraction
;
121 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
124 * A cached value of the page's pageblock's migratetype, used when the page is
125 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
126 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
127 * Also the migratetype set in the page does not necessarily match the pcplist
128 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
129 * other index - this ensures that it will be put on the correct CMA freelist.
131 static inline int get_pcppage_migratetype(struct page
*page
)
136 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
138 page
->index
= migratetype
;
141 #ifdef CONFIG_PM_SLEEP
143 * The following functions are used by the suspend/hibernate code to temporarily
144 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
145 * while devices are suspended. To avoid races with the suspend/hibernate code,
146 * they should always be called with pm_mutex held (gfp_allowed_mask also should
147 * only be modified with pm_mutex held, unless the suspend/hibernate code is
148 * guaranteed not to run in parallel with that modification).
151 static gfp_t saved_gfp_mask
;
153 void pm_restore_gfp_mask(void)
155 WARN_ON(!mutex_is_locked(&pm_mutex
));
156 if (saved_gfp_mask
) {
157 gfp_allowed_mask
= saved_gfp_mask
;
162 void pm_restrict_gfp_mask(void)
164 WARN_ON(!mutex_is_locked(&pm_mutex
));
165 WARN_ON(saved_gfp_mask
);
166 saved_gfp_mask
= gfp_allowed_mask
;
167 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
170 bool pm_suspended_storage(void)
172 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
176 #endif /* CONFIG_PM_SLEEP */
178 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
179 unsigned int pageblock_order __read_mostly
;
182 static void __free_pages_ok(struct page
*page
, unsigned int order
);
185 * results with 256, 32 in the lowmem_reserve sysctl:
186 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
187 * 1G machine -> (16M dma, 784M normal, 224M high)
188 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
189 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
190 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
192 * TBD: should special case ZONE_DMA32 machines here - in those we normally
193 * don't need any ZONE_NORMAL reservation
195 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
196 #ifdef CONFIG_ZONE_DMA
199 #ifdef CONFIG_ZONE_DMA32
202 #ifdef CONFIG_HIGHMEM
208 EXPORT_SYMBOL(totalram_pages
);
210 static char * const zone_names
[MAX_NR_ZONES
] = {
211 #ifdef CONFIG_ZONE_DMA
214 #ifdef CONFIG_ZONE_DMA32
218 #ifdef CONFIG_HIGHMEM
222 #ifdef CONFIG_ZONE_DEVICE
227 char * const migratetype_names
[MIGRATE_TYPES
] = {
235 #ifdef CONFIG_MEMORY_ISOLATION
240 compound_page_dtor
* const compound_page_dtors
[] = {
243 #ifdef CONFIG_HUGETLB_PAGE
246 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
251 int min_free_kbytes
= 1024;
252 int user_min_free_kbytes
= -1;
253 int watermark_scale_factor
= 10;
255 static unsigned long __meminitdata nr_kernel_pages
;
256 static unsigned long __meminitdata nr_all_pages
;
257 static unsigned long __meminitdata dma_reserve
;
259 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
260 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
261 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
262 static unsigned long __initdata required_kernelcore
;
263 static unsigned long __initdata required_movablecore
;
264 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
265 static bool mirrored_kernelcore
;
267 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
269 EXPORT_SYMBOL(movable_zone
);
270 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
273 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
274 int nr_online_nodes __read_mostly
= 1;
275 EXPORT_SYMBOL(nr_node_ids
);
276 EXPORT_SYMBOL(nr_online_nodes
);
279 int page_group_by_mobility_disabled __read_mostly
;
281 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
282 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
284 pgdat
->first_deferred_pfn
= ULONG_MAX
;
287 /* Returns true if the struct page for the pfn is uninitialised */
288 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
290 int nid
= early_pfn_to_nid(pfn
);
292 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
299 * Returns false when the remaining initialisation should be deferred until
300 * later in the boot cycle when it can be parallelised.
302 static inline bool update_defer_init(pg_data_t
*pgdat
,
303 unsigned long pfn
, unsigned long zone_end
,
304 unsigned long *nr_initialised
)
306 unsigned long max_initialise
;
308 /* Always populate low zones for address-contrained allocations */
309 if (zone_end
< pgdat_end_pfn(pgdat
))
312 * Initialise at least 2G of a node but also take into account that
313 * two large system hashes that can take up 1GB for 0.25TB/node.
315 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
316 (pgdat
->node_spanned_pages
>> 8));
319 if ((*nr_initialised
> max_initialise
) &&
320 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
321 pgdat
->first_deferred_pfn
= pfn
;
328 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
332 static inline bool early_page_uninitialised(unsigned long pfn
)
337 static inline bool update_defer_init(pg_data_t
*pgdat
,
338 unsigned long pfn
, unsigned long zone_end
,
339 unsigned long *nr_initialised
)
345 /* Return a pointer to the bitmap storing bits affecting a block of pages */
346 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
349 #ifdef CONFIG_SPARSEMEM
350 return __pfn_to_section(pfn
)->pageblock_flags
;
352 return page_zone(page
)->pageblock_flags
;
353 #endif /* CONFIG_SPARSEMEM */
356 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
358 #ifdef CONFIG_SPARSEMEM
359 pfn
&= (PAGES_PER_SECTION
-1);
360 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
362 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
363 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
364 #endif /* CONFIG_SPARSEMEM */
368 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
369 * @page: The page within the block of interest
370 * @pfn: The target page frame number
371 * @end_bitidx: The last bit of interest to retrieve
372 * @mask: mask of bits that the caller is interested in
374 * Return: pageblock_bits flags
376 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
378 unsigned long end_bitidx
,
381 unsigned long *bitmap
;
382 unsigned long bitidx
, word_bitidx
;
385 bitmap
= get_pageblock_bitmap(page
, pfn
);
386 bitidx
= pfn_to_bitidx(page
, pfn
);
387 word_bitidx
= bitidx
/ BITS_PER_LONG
;
388 bitidx
&= (BITS_PER_LONG
-1);
390 word
= bitmap
[word_bitidx
];
391 bitidx
+= end_bitidx
;
392 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
395 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
396 unsigned long end_bitidx
,
399 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
402 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
404 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
408 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
409 * @page: The page within the block of interest
410 * @flags: The flags to set
411 * @pfn: The target page frame number
412 * @end_bitidx: The last bit of interest
413 * @mask: mask of bits that the caller is interested in
415 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
417 unsigned long end_bitidx
,
420 unsigned long *bitmap
;
421 unsigned long bitidx
, word_bitidx
;
422 unsigned long old_word
, word
;
424 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
426 bitmap
= get_pageblock_bitmap(page
, pfn
);
427 bitidx
= pfn_to_bitidx(page
, pfn
);
428 word_bitidx
= bitidx
/ BITS_PER_LONG
;
429 bitidx
&= (BITS_PER_LONG
-1);
431 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
433 bitidx
+= end_bitidx
;
434 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
435 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
437 word
= READ_ONCE(bitmap
[word_bitidx
]);
439 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
440 if (word
== old_word
)
446 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
448 if (unlikely(page_group_by_mobility_disabled
&&
449 migratetype
< MIGRATE_PCPTYPES
))
450 migratetype
= MIGRATE_UNMOVABLE
;
452 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
453 PB_migrate
, PB_migrate_end
);
456 #ifdef CONFIG_DEBUG_VM
457 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
461 unsigned long pfn
= page_to_pfn(page
);
462 unsigned long sp
, start_pfn
;
465 seq
= zone_span_seqbegin(zone
);
466 start_pfn
= zone
->zone_start_pfn
;
467 sp
= zone
->spanned_pages
;
468 if (!zone_spans_pfn(zone
, pfn
))
470 } while (zone_span_seqretry(zone
, seq
));
473 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
474 pfn
, zone_to_nid(zone
), zone
->name
,
475 start_pfn
, start_pfn
+ sp
);
480 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
482 if (!pfn_valid_within(page_to_pfn(page
)))
484 if (zone
!= page_zone(page
))
490 * Temporary debugging check for pages not lying within a given zone.
492 static int bad_range(struct zone
*zone
, struct page
*page
)
494 if (page_outside_zone_boundaries(zone
, page
))
496 if (!page_is_consistent(zone
, page
))
502 static inline int bad_range(struct zone
*zone
, struct page
*page
)
508 static void bad_page(struct page
*page
, const char *reason
,
509 unsigned long bad_flags
)
511 static unsigned long resume
;
512 static unsigned long nr_shown
;
513 static unsigned long nr_unshown
;
516 * Allow a burst of 60 reports, then keep quiet for that minute;
517 * or allow a steady drip of one report per second.
519 if (nr_shown
== 60) {
520 if (time_before(jiffies
, resume
)) {
526 "BUG: Bad page state: %lu messages suppressed\n",
533 resume
= jiffies
+ 60 * HZ
;
535 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
536 current
->comm
, page_to_pfn(page
));
537 __dump_page(page
, reason
);
538 bad_flags
&= page
->flags
;
540 pr_alert("bad because of flags: %#lx(%pGp)\n",
541 bad_flags
, &bad_flags
);
542 dump_page_owner(page
);
547 /* Leave bad fields for debug, except PageBuddy could make trouble */
548 page_mapcount_reset(page
); /* remove PageBuddy */
549 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
553 * Higher-order pages are called "compound pages". They are structured thusly:
555 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
557 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
558 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
560 * The first tail page's ->compound_dtor holds the offset in array of compound
561 * page destructors. See compound_page_dtors.
563 * The first tail page's ->compound_order holds the order of allocation.
564 * This usage means that zero-order pages may not be compound.
567 void free_compound_page(struct page
*page
)
569 __free_pages_ok(page
, compound_order(page
));
572 void prep_compound_page(struct page
*page
, unsigned int order
)
575 int nr_pages
= 1 << order
;
577 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
578 set_compound_order(page
, order
);
580 for (i
= 1; i
< nr_pages
; i
++) {
581 struct page
*p
= page
+ i
;
582 set_page_count(p
, 0);
583 p
->mapping
= TAIL_MAPPING
;
584 set_compound_head(p
, page
);
586 atomic_set(compound_mapcount_ptr(page
), -1);
589 #ifdef CONFIG_DEBUG_PAGEALLOC
590 unsigned int _debug_guardpage_minorder
;
591 bool _debug_pagealloc_enabled __read_mostly
592 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
593 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
594 bool _debug_guardpage_enabled __read_mostly
;
596 static int __init
early_debug_pagealloc(char *buf
)
600 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
602 early_param("debug_pagealloc", early_debug_pagealloc
);
604 static bool need_debug_guardpage(void)
606 /* If we don't use debug_pagealloc, we don't need guard page */
607 if (!debug_pagealloc_enabled())
613 static void init_debug_guardpage(void)
615 if (!debug_pagealloc_enabled())
618 _debug_guardpage_enabled
= true;
621 struct page_ext_operations debug_guardpage_ops
= {
622 .need
= need_debug_guardpage
,
623 .init
= init_debug_guardpage
,
626 static int __init
debug_guardpage_minorder_setup(char *buf
)
630 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
631 pr_err("Bad debug_guardpage_minorder value\n");
634 _debug_guardpage_minorder
= res
;
635 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
638 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
640 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
641 unsigned int order
, int migratetype
)
643 struct page_ext
*page_ext
;
645 if (!debug_guardpage_enabled())
648 page_ext
= lookup_page_ext(page
);
649 if (unlikely(!page_ext
))
652 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
654 INIT_LIST_HEAD(&page
->lru
);
655 set_page_private(page
, order
);
656 /* Guard pages are not available for any usage */
657 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
660 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
661 unsigned int order
, int migratetype
)
663 struct page_ext
*page_ext
;
665 if (!debug_guardpage_enabled())
668 page_ext
= lookup_page_ext(page
);
669 if (unlikely(!page_ext
))
672 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
674 set_page_private(page
, 0);
675 if (!is_migrate_isolate(migratetype
))
676 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
679 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
680 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
681 unsigned int order
, int migratetype
) {}
682 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
683 unsigned int order
, int migratetype
) {}
686 static inline void set_page_order(struct page
*page
, unsigned int order
)
688 set_page_private(page
, order
);
689 __SetPageBuddy(page
);
692 static inline void rmv_page_order(struct page
*page
)
694 __ClearPageBuddy(page
);
695 set_page_private(page
, 0);
699 * This function checks whether a page is free && is the buddy
700 * we can do coalesce a page and its buddy if
701 * (a) the buddy is not in a hole &&
702 * (b) the buddy is in the buddy system &&
703 * (c) a page and its buddy have the same order &&
704 * (d) a page and its buddy are in the same zone.
706 * For recording whether a page is in the buddy system, we set ->_mapcount
707 * PAGE_BUDDY_MAPCOUNT_VALUE.
708 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
709 * serialized by zone->lock.
711 * For recording page's order, we use page_private(page).
713 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
716 if (!pfn_valid_within(page_to_pfn(buddy
)))
719 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
720 if (page_zone_id(page
) != page_zone_id(buddy
))
723 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
728 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
730 * zone check is done late to avoid uselessly
731 * calculating zone/node ids for pages that could
734 if (page_zone_id(page
) != page_zone_id(buddy
))
737 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
745 * Freeing function for a buddy system allocator.
747 * The concept of a buddy system is to maintain direct-mapped table
748 * (containing bit values) for memory blocks of various "orders".
749 * The bottom level table contains the map for the smallest allocatable
750 * units of memory (here, pages), and each level above it describes
751 * pairs of units from the levels below, hence, "buddies".
752 * At a high level, all that happens here is marking the table entry
753 * at the bottom level available, and propagating the changes upward
754 * as necessary, plus some accounting needed to play nicely with other
755 * parts of the VM system.
756 * At each level, we keep a list of pages, which are heads of continuous
757 * free pages of length of (1 << order) and marked with _mapcount
758 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
760 * So when we are allocating or freeing one, we can derive the state of the
761 * other. That is, if we allocate a small block, and both were
762 * free, the remainder of the region must be split into blocks.
763 * If a block is freed, and its buddy is also free, then this
764 * triggers coalescing into a block of larger size.
769 static inline void __free_one_page(struct page
*page
,
771 struct zone
*zone
, unsigned int order
,
774 unsigned long page_idx
;
775 unsigned long combined_idx
;
776 unsigned long uninitialized_var(buddy_idx
);
778 unsigned int max_order
;
780 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
782 VM_BUG_ON(!zone_is_initialized(zone
));
783 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
785 VM_BUG_ON(migratetype
== -1);
786 if (likely(!is_migrate_isolate(migratetype
)))
787 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
789 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
791 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
792 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
795 while (order
< max_order
- 1) {
796 buddy_idx
= __find_buddy_index(page_idx
, order
);
797 buddy
= page
+ (buddy_idx
- page_idx
);
798 if (!page_is_buddy(page
, buddy
, order
))
801 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
802 * merge with it and move up one order.
804 if (page_is_guard(buddy
)) {
805 clear_page_guard(zone
, buddy
, order
, migratetype
);
807 list_del(&buddy
->lru
);
808 zone
->free_area
[order
].nr_free
--;
809 rmv_page_order(buddy
);
811 combined_idx
= buddy_idx
& page_idx
;
812 page
= page
+ (combined_idx
- page_idx
);
813 page_idx
= combined_idx
;
816 if (max_order
< MAX_ORDER
) {
817 /* If we are here, it means order is >= pageblock_order.
818 * We want to prevent merge between freepages on isolate
819 * pageblock and normal pageblock. Without this, pageblock
820 * isolation could cause incorrect freepage or CMA accounting.
822 * We don't want to hit this code for the more frequent
825 if (unlikely(has_isolate_pageblock(zone
))) {
828 buddy_idx
= __find_buddy_index(page_idx
, order
);
829 buddy
= page
+ (buddy_idx
- page_idx
);
830 buddy_mt
= get_pageblock_migratetype(buddy
);
832 if (migratetype
!= buddy_mt
833 && (is_migrate_isolate(migratetype
) ||
834 is_migrate_isolate(buddy_mt
)))
838 goto continue_merging
;
842 set_page_order(page
, order
);
845 * If this is not the largest possible page, check if the buddy
846 * of the next-highest order is free. If it is, it's possible
847 * that pages are being freed that will coalesce soon. In case,
848 * that is happening, add the free page to the tail of the list
849 * so it's less likely to be used soon and more likely to be merged
850 * as a higher order page
852 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
853 struct page
*higher_page
, *higher_buddy
;
854 combined_idx
= buddy_idx
& page_idx
;
855 higher_page
= page
+ (combined_idx
- page_idx
);
856 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
857 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
858 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
859 list_add_tail(&page
->lru
,
860 &zone
->free_area
[order
].free_list
[migratetype
]);
865 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
867 zone
->free_area
[order
].nr_free
++;
871 * A bad page could be due to a number of fields. Instead of multiple branches,
872 * try and check multiple fields with one check. The caller must do a detailed
873 * check if necessary.
875 static inline bool page_expected_state(struct page
*page
,
876 unsigned long check_flags
)
878 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
881 if (unlikely((unsigned long)page
->mapping
|
882 page_ref_count(page
) |
884 (unsigned long)page
->mem_cgroup
|
886 (page
->flags
& check_flags
)))
892 static void free_pages_check_bad(struct page
*page
)
894 const char *bad_reason
;
895 unsigned long bad_flags
;
900 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
901 bad_reason
= "nonzero mapcount";
902 if (unlikely(page
->mapping
!= NULL
))
903 bad_reason
= "non-NULL mapping";
904 if (unlikely(page_ref_count(page
) != 0))
905 bad_reason
= "nonzero _refcount";
906 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
907 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
908 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
911 if (unlikely(page
->mem_cgroup
))
912 bad_reason
= "page still charged to cgroup";
914 bad_page(page
, bad_reason
, bad_flags
);
917 static inline int free_pages_check(struct page
*page
)
919 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
922 /* Something has gone sideways, find it */
923 free_pages_check_bad(page
);
927 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
932 * We rely page->lru.next never has bit 0 set, unless the page
933 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
935 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
937 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
941 switch (page
- head_page
) {
943 /* the first tail page: ->mapping is compound_mapcount() */
944 if (unlikely(compound_mapcount(page
))) {
945 bad_page(page
, "nonzero compound_mapcount", 0);
951 * the second tail page: ->mapping is
952 * page_deferred_list().next -- ignore value.
956 if (page
->mapping
!= TAIL_MAPPING
) {
957 bad_page(page
, "corrupted mapping in tail page", 0);
962 if (unlikely(!PageTail(page
))) {
963 bad_page(page
, "PageTail not set", 0);
966 if (unlikely(compound_head(page
) != head_page
)) {
967 bad_page(page
, "compound_head not consistent", 0);
972 page
->mapping
= NULL
;
973 clear_compound_head(page
);
977 static __always_inline
bool free_pages_prepare(struct page
*page
,
978 unsigned int order
, bool check_free
)
982 VM_BUG_ON_PAGE(PageTail(page
), page
);
984 trace_mm_page_free(page
, order
);
985 kmemcheck_free_shadow(page
, order
);
988 * Check tail pages before head page information is cleared to
989 * avoid checking PageCompound for order-0 pages.
991 if (unlikely(order
)) {
992 bool compound
= PageCompound(page
);
995 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
998 ClearPageDoubleMap(page
);
999 for (i
= 1; i
< (1 << order
); i
++) {
1001 bad
+= free_tail_pages_check(page
, page
+ i
);
1002 if (unlikely(free_pages_check(page
+ i
))) {
1006 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1009 if (PageMappingFlags(page
))
1010 page
->mapping
= NULL
;
1011 if (memcg_kmem_enabled() && PageKmemcg(page
)) {
1012 memcg_kmem_uncharge(page
, order
);
1013 __ClearPageKmemcg(page
);
1016 bad
+= free_pages_check(page
);
1020 page_cpupid_reset_last(page
);
1021 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1022 reset_page_owner(page
, order
);
1024 if (!PageHighMem(page
)) {
1025 debug_check_no_locks_freed(page_address(page
),
1026 PAGE_SIZE
<< order
);
1027 debug_check_no_obj_freed(page_address(page
),
1028 PAGE_SIZE
<< order
);
1030 arch_free_page(page
, order
);
1031 kernel_poison_pages(page
, 1 << order
, 0);
1032 kernel_map_pages(page
, 1 << order
, 0);
1033 kasan_free_pages(page
, order
);
1038 #ifdef CONFIG_DEBUG_VM
1039 static inline bool free_pcp_prepare(struct page
*page
)
1041 return free_pages_prepare(page
, 0, true);
1044 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1049 static bool free_pcp_prepare(struct page
*page
)
1051 return free_pages_prepare(page
, 0, false);
1054 static bool bulkfree_pcp_prepare(struct page
*page
)
1056 return free_pages_check(page
);
1058 #endif /* CONFIG_DEBUG_VM */
1061 * Frees a number of pages from the PCP lists
1062 * Assumes all pages on list are in same zone, and of same order.
1063 * count is the number of pages to free.
1065 * If the zone was previously in an "all pages pinned" state then look to
1066 * see if this freeing clears that state.
1068 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1069 * pinned" detection logic.
1071 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1072 struct per_cpu_pages
*pcp
)
1074 int migratetype
= 0;
1076 unsigned long nr_scanned
;
1077 bool isolated_pageblocks
;
1079 spin_lock(&zone
->lock
);
1080 isolated_pageblocks
= has_isolate_pageblock(zone
);
1081 nr_scanned
= node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
);
1083 __mod_node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
, -nr_scanned
);
1087 struct list_head
*list
;
1090 * Remove pages from lists in a round-robin fashion. A
1091 * batch_free count is maintained that is incremented when an
1092 * empty list is encountered. This is so more pages are freed
1093 * off fuller lists instead of spinning excessively around empty
1098 if (++migratetype
== MIGRATE_PCPTYPES
)
1100 list
= &pcp
->lists
[migratetype
];
1101 } while (list_empty(list
));
1103 /* This is the only non-empty list. Free them all. */
1104 if (batch_free
== MIGRATE_PCPTYPES
)
1108 int mt
; /* migratetype of the to-be-freed page */
1110 page
= list_last_entry(list
, struct page
, lru
);
1111 /* must delete as __free_one_page list manipulates */
1112 list_del(&page
->lru
);
1114 mt
= get_pcppage_migratetype(page
);
1115 /* MIGRATE_ISOLATE page should not go to pcplists */
1116 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1117 /* Pageblock could have been isolated meanwhile */
1118 if (unlikely(isolated_pageblocks
))
1119 mt
= get_pageblock_migratetype(page
);
1121 if (bulkfree_pcp_prepare(page
))
1124 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1125 trace_mm_page_pcpu_drain(page
, 0, mt
);
1126 } while (--count
&& --batch_free
&& !list_empty(list
));
1128 spin_unlock(&zone
->lock
);
1131 static void free_one_page(struct zone
*zone
,
1132 struct page
*page
, unsigned long pfn
,
1136 unsigned long nr_scanned
;
1137 spin_lock(&zone
->lock
);
1138 nr_scanned
= node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
);
1140 __mod_node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
, -nr_scanned
);
1142 if (unlikely(has_isolate_pageblock(zone
) ||
1143 is_migrate_isolate(migratetype
))) {
1144 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1146 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1147 spin_unlock(&zone
->lock
);
1150 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1151 unsigned long zone
, int nid
)
1153 set_page_links(page
, zone
, nid
, pfn
);
1154 init_page_count(page
);
1155 page_mapcount_reset(page
);
1156 page_cpupid_reset_last(page
);
1158 INIT_LIST_HEAD(&page
->lru
);
1159 #ifdef WANT_PAGE_VIRTUAL
1160 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1161 if (!is_highmem_idx(zone
))
1162 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1166 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1169 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1172 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1173 static void init_reserved_page(unsigned long pfn
)
1178 if (!early_page_uninitialised(pfn
))
1181 nid
= early_pfn_to_nid(pfn
);
1182 pgdat
= NODE_DATA(nid
);
1184 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1185 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1187 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1190 __init_single_pfn(pfn
, zid
, nid
);
1193 static inline void init_reserved_page(unsigned long pfn
)
1196 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1199 * Initialised pages do not have PageReserved set. This function is
1200 * called for each range allocated by the bootmem allocator and
1201 * marks the pages PageReserved. The remaining valid pages are later
1202 * sent to the buddy page allocator.
1204 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1206 unsigned long start_pfn
= PFN_DOWN(start
);
1207 unsigned long end_pfn
= PFN_UP(end
);
1209 for (; start_pfn
< end_pfn
; start_pfn
++) {
1210 if (pfn_valid(start_pfn
)) {
1211 struct page
*page
= pfn_to_page(start_pfn
);
1213 init_reserved_page(start_pfn
);
1215 /* Avoid false-positive PageTail() */
1216 INIT_LIST_HEAD(&page
->lru
);
1218 SetPageReserved(page
);
1223 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1225 unsigned long flags
;
1227 unsigned long pfn
= page_to_pfn(page
);
1229 if (!free_pages_prepare(page
, order
, true))
1232 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1233 local_irq_save(flags
);
1234 __count_vm_events(PGFREE
, 1 << order
);
1235 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1236 local_irq_restore(flags
);
1239 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1241 unsigned int nr_pages
= 1 << order
;
1242 struct page
*p
= page
;
1246 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1248 __ClearPageReserved(p
);
1249 set_page_count(p
, 0);
1251 __ClearPageReserved(p
);
1252 set_page_count(p
, 0);
1254 page_zone(page
)->managed_pages
+= nr_pages
;
1255 set_page_refcounted(page
);
1256 __free_pages(page
, order
);
1259 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1260 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1262 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1264 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1266 static DEFINE_SPINLOCK(early_pfn_lock
);
1269 spin_lock(&early_pfn_lock
);
1270 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1272 nid
= first_online_node
;
1273 spin_unlock(&early_pfn_lock
);
1279 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1280 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1281 struct mminit_pfnnid_cache
*state
)
1285 nid
= __early_pfn_to_nid(pfn
, state
);
1286 if (nid
>= 0 && nid
!= node
)
1291 /* Only safe to use early in boot when initialisation is single-threaded */
1292 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1294 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1299 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1303 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1304 struct mminit_pfnnid_cache
*state
)
1311 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1314 if (early_page_uninitialised(pfn
))
1316 return __free_pages_boot_core(page
, order
);
1320 * Check that the whole (or subset of) a pageblock given by the interval of
1321 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1322 * with the migration of free compaction scanner. The scanners then need to
1323 * use only pfn_valid_within() check for arches that allow holes within
1326 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1328 * It's possible on some configurations to have a setup like node0 node1 node0
1329 * i.e. it's possible that all pages within a zones range of pages do not
1330 * belong to a single zone. We assume that a border between node0 and node1
1331 * can occur within a single pageblock, but not a node0 node1 node0
1332 * interleaving within a single pageblock. It is therefore sufficient to check
1333 * the first and last page of a pageblock and avoid checking each individual
1334 * page in a pageblock.
1336 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1337 unsigned long end_pfn
, struct zone
*zone
)
1339 struct page
*start_page
;
1340 struct page
*end_page
;
1342 /* end_pfn is one past the range we are checking */
1345 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1348 start_page
= pfn_to_page(start_pfn
);
1350 if (page_zone(start_page
) != zone
)
1353 end_page
= pfn_to_page(end_pfn
);
1355 /* This gives a shorter code than deriving page_zone(end_page) */
1356 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1362 void set_zone_contiguous(struct zone
*zone
)
1364 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1365 unsigned long block_end_pfn
;
1367 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1368 for (; block_start_pfn
< zone_end_pfn(zone
);
1369 block_start_pfn
= block_end_pfn
,
1370 block_end_pfn
+= pageblock_nr_pages
) {
1372 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1374 if (!__pageblock_pfn_to_page(block_start_pfn
,
1375 block_end_pfn
, zone
))
1379 /* We confirm that there is no hole */
1380 zone
->contiguous
= true;
1383 void clear_zone_contiguous(struct zone
*zone
)
1385 zone
->contiguous
= false;
1388 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1389 static void __init
deferred_free_range(struct page
*page
,
1390 unsigned long pfn
, int nr_pages
)
1397 /* Free a large naturally-aligned chunk if possible */
1398 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1399 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1400 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1401 __free_pages_boot_core(page
, MAX_ORDER
-1);
1405 for (i
= 0; i
< nr_pages
; i
++, page
++)
1406 __free_pages_boot_core(page
, 0);
1409 /* Completion tracking for deferred_init_memmap() threads */
1410 static atomic_t pgdat_init_n_undone __initdata
;
1411 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1413 static inline void __init
pgdat_init_report_one_done(void)
1415 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1416 complete(&pgdat_init_all_done_comp
);
1419 /* Initialise remaining memory on a node */
1420 static int __init
deferred_init_memmap(void *data
)
1422 pg_data_t
*pgdat
= data
;
1423 int nid
= pgdat
->node_id
;
1424 struct mminit_pfnnid_cache nid_init_state
= { };
1425 unsigned long start
= jiffies
;
1426 unsigned long nr_pages
= 0;
1427 unsigned long walk_start
, walk_end
;
1430 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1431 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1433 if (first_init_pfn
== ULONG_MAX
) {
1434 pgdat_init_report_one_done();
1438 /* Bind memory initialisation thread to a local node if possible */
1439 if (!cpumask_empty(cpumask
))
1440 set_cpus_allowed_ptr(current
, cpumask
);
1442 /* Sanity check boundaries */
1443 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1444 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1445 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1447 /* Only the highest zone is deferred so find it */
1448 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1449 zone
= pgdat
->node_zones
+ zid
;
1450 if (first_init_pfn
< zone_end_pfn(zone
))
1454 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1455 unsigned long pfn
, end_pfn
;
1456 struct page
*page
= NULL
;
1457 struct page
*free_base_page
= NULL
;
1458 unsigned long free_base_pfn
= 0;
1461 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1462 pfn
= first_init_pfn
;
1463 if (pfn
< walk_start
)
1465 if (pfn
< zone
->zone_start_pfn
)
1466 pfn
= zone
->zone_start_pfn
;
1468 for (; pfn
< end_pfn
; pfn
++) {
1469 if (!pfn_valid_within(pfn
))
1473 * Ensure pfn_valid is checked every
1474 * MAX_ORDER_NR_PAGES for memory holes
1476 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1477 if (!pfn_valid(pfn
)) {
1483 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1488 /* Minimise pfn page lookups and scheduler checks */
1489 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1492 nr_pages
+= nr_to_free
;
1493 deferred_free_range(free_base_page
,
1494 free_base_pfn
, nr_to_free
);
1495 free_base_page
= NULL
;
1496 free_base_pfn
= nr_to_free
= 0;
1498 page
= pfn_to_page(pfn
);
1503 VM_BUG_ON(page_zone(page
) != zone
);
1507 __init_single_page(page
, pfn
, zid
, nid
);
1508 if (!free_base_page
) {
1509 free_base_page
= page
;
1510 free_base_pfn
= pfn
;
1515 /* Where possible, batch up pages for a single free */
1518 /* Free the current block of pages to allocator */
1519 nr_pages
+= nr_to_free
;
1520 deferred_free_range(free_base_page
, free_base_pfn
,
1522 free_base_page
= NULL
;
1523 free_base_pfn
= nr_to_free
= 0;
1526 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1529 /* Sanity check that the next zone really is unpopulated */
1530 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1532 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1533 jiffies_to_msecs(jiffies
- start
));
1535 pgdat_init_report_one_done();
1538 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1540 void __init
page_alloc_init_late(void)
1544 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1547 /* There will be num_node_state(N_MEMORY) threads */
1548 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1549 for_each_node_state(nid
, N_MEMORY
) {
1550 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1553 /* Block until all are initialised */
1554 wait_for_completion(&pgdat_init_all_done_comp
);
1556 /* Reinit limits that are based on free pages after the kernel is up */
1557 files_maxfiles_init();
1560 for_each_populated_zone(zone
)
1561 set_zone_contiguous(zone
);
1565 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1566 void __init
init_cma_reserved_pageblock(struct page
*page
)
1568 unsigned i
= pageblock_nr_pages
;
1569 struct page
*p
= page
;
1572 __ClearPageReserved(p
);
1573 set_page_count(p
, 0);
1576 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1578 if (pageblock_order
>= MAX_ORDER
) {
1579 i
= pageblock_nr_pages
;
1582 set_page_refcounted(p
);
1583 __free_pages(p
, MAX_ORDER
- 1);
1584 p
+= MAX_ORDER_NR_PAGES
;
1585 } while (i
-= MAX_ORDER_NR_PAGES
);
1587 set_page_refcounted(page
);
1588 __free_pages(page
, pageblock_order
);
1591 adjust_managed_page_count(page
, pageblock_nr_pages
);
1596 * The order of subdivision here is critical for the IO subsystem.
1597 * Please do not alter this order without good reasons and regression
1598 * testing. Specifically, as large blocks of memory are subdivided,
1599 * the order in which smaller blocks are delivered depends on the order
1600 * they're subdivided in this function. This is the primary factor
1601 * influencing the order in which pages are delivered to the IO
1602 * subsystem according to empirical testing, and this is also justified
1603 * by considering the behavior of a buddy system containing a single
1604 * large block of memory acted on by a series of small allocations.
1605 * This behavior is a critical factor in sglist merging's success.
1609 static inline void expand(struct zone
*zone
, struct page
*page
,
1610 int low
, int high
, struct free_area
*area
,
1613 unsigned long size
= 1 << high
;
1615 while (high
> low
) {
1619 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1621 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1622 debug_guardpage_enabled() &&
1623 high
< debug_guardpage_minorder()) {
1625 * Mark as guard pages (or page), that will allow to
1626 * merge back to allocator when buddy will be freed.
1627 * Corresponding page table entries will not be touched,
1628 * pages will stay not present in virtual address space
1630 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1633 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1635 set_page_order(&page
[size
], high
);
1639 static void check_new_page_bad(struct page
*page
)
1641 const char *bad_reason
= NULL
;
1642 unsigned long bad_flags
= 0;
1644 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1645 bad_reason
= "nonzero mapcount";
1646 if (unlikely(page
->mapping
!= NULL
))
1647 bad_reason
= "non-NULL mapping";
1648 if (unlikely(page_ref_count(page
) != 0))
1649 bad_reason
= "nonzero _count";
1650 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1651 bad_reason
= "HWPoisoned (hardware-corrupted)";
1652 bad_flags
= __PG_HWPOISON
;
1653 /* Don't complain about hwpoisoned pages */
1654 page_mapcount_reset(page
); /* remove PageBuddy */
1657 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1658 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1659 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1662 if (unlikely(page
->mem_cgroup
))
1663 bad_reason
= "page still charged to cgroup";
1665 bad_page(page
, bad_reason
, bad_flags
);
1669 * This page is about to be returned from the page allocator
1671 static inline int check_new_page(struct page
*page
)
1673 if (likely(page_expected_state(page
,
1674 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1677 check_new_page_bad(page
);
1681 static inline bool free_pages_prezeroed(bool poisoned
)
1683 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1684 page_poisoning_enabled() && poisoned
;
1687 #ifdef CONFIG_DEBUG_VM
1688 static bool check_pcp_refill(struct page
*page
)
1693 static bool check_new_pcp(struct page
*page
)
1695 return check_new_page(page
);
1698 static bool check_pcp_refill(struct page
*page
)
1700 return check_new_page(page
);
1702 static bool check_new_pcp(struct page
*page
)
1706 #endif /* CONFIG_DEBUG_VM */
1708 static bool check_new_pages(struct page
*page
, unsigned int order
)
1711 for (i
= 0; i
< (1 << order
); i
++) {
1712 struct page
*p
= page
+ i
;
1714 if (unlikely(check_new_page(p
)))
1721 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1724 set_page_private(page
, 0);
1725 set_page_refcounted(page
);
1727 arch_alloc_page(page
, order
);
1728 kernel_map_pages(page
, 1 << order
, 1);
1729 kernel_poison_pages(page
, 1 << order
, 1);
1730 kasan_alloc_pages(page
, order
);
1731 set_page_owner(page
, order
, gfp_flags
);
1734 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1735 unsigned int alloc_flags
)
1738 bool poisoned
= true;
1740 for (i
= 0; i
< (1 << order
); i
++) {
1741 struct page
*p
= page
+ i
;
1743 poisoned
&= page_is_poisoned(p
);
1746 post_alloc_hook(page
, order
, gfp_flags
);
1748 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1749 for (i
= 0; i
< (1 << order
); i
++)
1750 clear_highpage(page
+ i
);
1752 if (order
&& (gfp_flags
& __GFP_COMP
))
1753 prep_compound_page(page
, order
);
1756 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1757 * allocate the page. The expectation is that the caller is taking
1758 * steps that will free more memory. The caller should avoid the page
1759 * being used for !PFMEMALLOC purposes.
1761 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1762 set_page_pfmemalloc(page
);
1764 clear_page_pfmemalloc(page
);
1768 * Go through the free lists for the given migratetype and remove
1769 * the smallest available page from the freelists
1772 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1775 unsigned int current_order
;
1776 struct free_area
*area
;
1779 /* Find a page of the appropriate size in the preferred list */
1780 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1781 area
= &(zone
->free_area
[current_order
]);
1782 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1786 list_del(&page
->lru
);
1787 rmv_page_order(page
);
1789 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1790 set_pcppage_migratetype(page
, migratetype
);
1799 * This array describes the order lists are fallen back to when
1800 * the free lists for the desirable migrate type are depleted
1802 static int fallbacks
[MIGRATE_TYPES
][4] = {
1803 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1804 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1805 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1807 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1809 #ifdef CONFIG_MEMORY_ISOLATION
1810 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1815 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1818 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1821 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1822 unsigned int order
) { return NULL
; }
1826 * Move the free pages in a range to the free lists of the requested type.
1827 * Note that start_page and end_pages are not aligned on a pageblock
1828 * boundary. If alignment is required, use move_freepages_block()
1830 int move_freepages(struct zone
*zone
,
1831 struct page
*start_page
, struct page
*end_page
,
1836 int pages_moved
= 0;
1838 #ifndef CONFIG_HOLES_IN_ZONE
1840 * page_zone is not safe to call in this context when
1841 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1842 * anyway as we check zone boundaries in move_freepages_block().
1843 * Remove at a later date when no bug reports exist related to
1844 * grouping pages by mobility
1846 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1849 for (page
= start_page
; page
<= end_page
;) {
1850 /* Make sure we are not inadvertently changing nodes */
1851 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1853 if (!pfn_valid_within(page_to_pfn(page
))) {
1858 if (!PageBuddy(page
)) {
1863 order
= page_order(page
);
1864 list_move(&page
->lru
,
1865 &zone
->free_area
[order
].free_list
[migratetype
]);
1867 pages_moved
+= 1 << order
;
1873 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1876 unsigned long start_pfn
, end_pfn
;
1877 struct page
*start_page
, *end_page
;
1879 start_pfn
= page_to_pfn(page
);
1880 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1881 start_page
= pfn_to_page(start_pfn
);
1882 end_page
= start_page
+ pageblock_nr_pages
- 1;
1883 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1885 /* Do not cross zone boundaries */
1886 if (!zone_spans_pfn(zone
, start_pfn
))
1888 if (!zone_spans_pfn(zone
, end_pfn
))
1891 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1894 static void change_pageblock_range(struct page
*pageblock_page
,
1895 int start_order
, int migratetype
)
1897 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1899 while (nr_pageblocks
--) {
1900 set_pageblock_migratetype(pageblock_page
, migratetype
);
1901 pageblock_page
+= pageblock_nr_pages
;
1906 * When we are falling back to another migratetype during allocation, try to
1907 * steal extra free pages from the same pageblocks to satisfy further
1908 * allocations, instead of polluting multiple pageblocks.
1910 * If we are stealing a relatively large buddy page, it is likely there will
1911 * be more free pages in the pageblock, so try to steal them all. For
1912 * reclaimable and unmovable allocations, we steal regardless of page size,
1913 * as fragmentation caused by those allocations polluting movable pageblocks
1914 * is worse than movable allocations stealing from unmovable and reclaimable
1917 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1920 * Leaving this order check is intended, although there is
1921 * relaxed order check in next check. The reason is that
1922 * we can actually steal whole pageblock if this condition met,
1923 * but, below check doesn't guarantee it and that is just heuristic
1924 * so could be changed anytime.
1926 if (order
>= pageblock_order
)
1929 if (order
>= pageblock_order
/ 2 ||
1930 start_mt
== MIGRATE_RECLAIMABLE
||
1931 start_mt
== MIGRATE_UNMOVABLE
||
1932 page_group_by_mobility_disabled
)
1939 * This function implements actual steal behaviour. If order is large enough,
1940 * we can steal whole pageblock. If not, we first move freepages in this
1941 * pageblock and check whether half of pages are moved or not. If half of
1942 * pages are moved, we can change migratetype of pageblock and permanently
1943 * use it's pages as requested migratetype in the future.
1945 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1948 unsigned int current_order
= page_order(page
);
1951 /* Take ownership for orders >= pageblock_order */
1952 if (current_order
>= pageblock_order
) {
1953 change_pageblock_range(page
, current_order
, start_type
);
1957 pages
= move_freepages_block(zone
, page
, start_type
);
1959 /* Claim the whole block if over half of it is free */
1960 if (pages
>= (1 << (pageblock_order
-1)) ||
1961 page_group_by_mobility_disabled
)
1962 set_pageblock_migratetype(page
, start_type
);
1966 * Check whether there is a suitable fallback freepage with requested order.
1967 * If only_stealable is true, this function returns fallback_mt only if
1968 * we can steal other freepages all together. This would help to reduce
1969 * fragmentation due to mixed migratetype pages in one pageblock.
1971 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1972 int migratetype
, bool only_stealable
, bool *can_steal
)
1977 if (area
->nr_free
== 0)
1982 fallback_mt
= fallbacks
[migratetype
][i
];
1983 if (fallback_mt
== MIGRATE_TYPES
)
1986 if (list_empty(&area
->free_list
[fallback_mt
]))
1989 if (can_steal_fallback(order
, migratetype
))
1992 if (!only_stealable
)
2003 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2004 * there are no empty page blocks that contain a page with a suitable order
2006 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2007 unsigned int alloc_order
)
2010 unsigned long max_managed
, flags
;
2013 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2014 * Check is race-prone but harmless.
2016 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2017 if (zone
->nr_reserved_highatomic
>= max_managed
)
2020 spin_lock_irqsave(&zone
->lock
, flags
);
2022 /* Recheck the nr_reserved_highatomic limit under the lock */
2023 if (zone
->nr_reserved_highatomic
>= max_managed
)
2027 mt
= get_pageblock_migratetype(page
);
2028 if (mt
!= MIGRATE_HIGHATOMIC
&&
2029 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
2030 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2031 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2032 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
2036 spin_unlock_irqrestore(&zone
->lock
, flags
);
2040 * Used when an allocation is about to fail under memory pressure. This
2041 * potentially hurts the reliability of high-order allocations when under
2042 * intense memory pressure but failed atomic allocations should be easier
2043 * to recover from than an OOM.
2045 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
2047 struct zonelist
*zonelist
= ac
->zonelist
;
2048 unsigned long flags
;
2054 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2056 /* Preserve at least one pageblock */
2057 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
2060 spin_lock_irqsave(&zone
->lock
, flags
);
2061 for (order
= 0; order
< MAX_ORDER
; order
++) {
2062 struct free_area
*area
= &(zone
->free_area
[order
]);
2064 page
= list_first_entry_or_null(
2065 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2071 * It should never happen but changes to locking could
2072 * inadvertently allow a per-cpu drain to add pages
2073 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2074 * and watch for underflows.
2076 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
2077 zone
->nr_reserved_highatomic
);
2080 * Convert to ac->migratetype and avoid the normal
2081 * pageblock stealing heuristics. Minimally, the caller
2082 * is doing the work and needs the pages. More
2083 * importantly, if the block was always converted to
2084 * MIGRATE_UNMOVABLE or another type then the number
2085 * of pageblocks that cannot be completely freed
2088 set_pageblock_migratetype(page
, ac
->migratetype
);
2089 move_freepages_block(zone
, page
, ac
->migratetype
);
2090 spin_unlock_irqrestore(&zone
->lock
, flags
);
2093 spin_unlock_irqrestore(&zone
->lock
, flags
);
2097 /* Remove an element from the buddy allocator from the fallback list */
2098 static inline struct page
*
2099 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
2101 struct free_area
*area
;
2102 unsigned int current_order
;
2107 /* Find the largest possible block of pages in the other list */
2108 for (current_order
= MAX_ORDER
-1;
2109 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
2111 area
= &(zone
->free_area
[current_order
]);
2112 fallback_mt
= find_suitable_fallback(area
, current_order
,
2113 start_migratetype
, false, &can_steal
);
2114 if (fallback_mt
== -1)
2117 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2120 steal_suitable_fallback(zone
, page
, start_migratetype
);
2122 /* Remove the page from the freelists */
2124 list_del(&page
->lru
);
2125 rmv_page_order(page
);
2127 expand(zone
, page
, order
, current_order
, area
,
2130 * The pcppage_migratetype may differ from pageblock's
2131 * migratetype depending on the decisions in
2132 * find_suitable_fallback(). This is OK as long as it does not
2133 * differ for MIGRATE_CMA pageblocks. Those can be used as
2134 * fallback only via special __rmqueue_cma_fallback() function
2136 set_pcppage_migratetype(page
, start_migratetype
);
2138 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2139 start_migratetype
, fallback_mt
);
2148 * Do the hard work of removing an element from the buddy allocator.
2149 * Call me with the zone->lock already held.
2151 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2156 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2157 if (unlikely(!page
)) {
2158 if (migratetype
== MIGRATE_MOVABLE
)
2159 page
= __rmqueue_cma_fallback(zone
, order
);
2162 page
= __rmqueue_fallback(zone
, order
, migratetype
);
2165 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2170 * Obtain a specified number of elements from the buddy allocator, all under
2171 * a single hold of the lock, for efficiency. Add them to the supplied list.
2172 * Returns the number of new pages which were placed at *list.
2174 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2175 unsigned long count
, struct list_head
*list
,
2176 int migratetype
, bool cold
)
2180 spin_lock(&zone
->lock
);
2181 for (i
= 0; i
< count
; ++i
) {
2182 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2183 if (unlikely(page
== NULL
))
2186 if (unlikely(check_pcp_refill(page
)))
2190 * Split buddy pages returned by expand() are received here
2191 * in physical page order. The page is added to the callers and
2192 * list and the list head then moves forward. From the callers
2193 * perspective, the linked list is ordered by page number in
2194 * some conditions. This is useful for IO devices that can
2195 * merge IO requests if the physical pages are ordered
2199 list_add(&page
->lru
, list
);
2201 list_add_tail(&page
->lru
, list
);
2203 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2204 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2207 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2208 spin_unlock(&zone
->lock
);
2214 * Called from the vmstat counter updater to drain pagesets of this
2215 * currently executing processor on remote nodes after they have
2218 * Note that this function must be called with the thread pinned to
2219 * a single processor.
2221 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2223 unsigned long flags
;
2224 int to_drain
, batch
;
2226 local_irq_save(flags
);
2227 batch
= READ_ONCE(pcp
->batch
);
2228 to_drain
= min(pcp
->count
, batch
);
2230 free_pcppages_bulk(zone
, to_drain
, pcp
);
2231 pcp
->count
-= to_drain
;
2233 local_irq_restore(flags
);
2238 * Drain pcplists of the indicated processor and zone.
2240 * The processor must either be the current processor and the
2241 * thread pinned to the current processor or a processor that
2244 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2246 unsigned long flags
;
2247 struct per_cpu_pageset
*pset
;
2248 struct per_cpu_pages
*pcp
;
2250 local_irq_save(flags
);
2251 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2255 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2258 local_irq_restore(flags
);
2262 * Drain pcplists of all zones on the indicated processor.
2264 * The processor must either be the current processor and the
2265 * thread pinned to the current processor or a processor that
2268 static void drain_pages(unsigned int cpu
)
2272 for_each_populated_zone(zone
) {
2273 drain_pages_zone(cpu
, zone
);
2278 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2280 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2281 * the single zone's pages.
2283 void drain_local_pages(struct zone
*zone
)
2285 int cpu
= smp_processor_id();
2288 drain_pages_zone(cpu
, zone
);
2294 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2296 * When zone parameter is non-NULL, spill just the single zone's pages.
2298 * Note that this code is protected against sending an IPI to an offline
2299 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2300 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2301 * nothing keeps CPUs from showing up after we populated the cpumask and
2302 * before the call to on_each_cpu_mask().
2304 void drain_all_pages(struct zone
*zone
)
2309 * Allocate in the BSS so we wont require allocation in
2310 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2312 static cpumask_t cpus_with_pcps
;
2315 * We don't care about racing with CPU hotplug event
2316 * as offline notification will cause the notified
2317 * cpu to drain that CPU pcps and on_each_cpu_mask
2318 * disables preemption as part of its processing
2320 for_each_online_cpu(cpu
) {
2321 struct per_cpu_pageset
*pcp
;
2323 bool has_pcps
= false;
2326 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2330 for_each_populated_zone(z
) {
2331 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2332 if (pcp
->pcp
.count
) {
2340 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2342 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2344 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2348 #ifdef CONFIG_HIBERNATION
2350 void mark_free_pages(struct zone
*zone
)
2352 unsigned long pfn
, max_zone_pfn
;
2353 unsigned long flags
;
2354 unsigned int order
, t
;
2357 if (zone_is_empty(zone
))
2360 spin_lock_irqsave(&zone
->lock
, flags
);
2362 max_zone_pfn
= zone_end_pfn(zone
);
2363 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2364 if (pfn_valid(pfn
)) {
2365 page
= pfn_to_page(pfn
);
2367 if (page_zone(page
) != zone
)
2370 if (!swsusp_page_is_forbidden(page
))
2371 swsusp_unset_page_free(page
);
2374 for_each_migratetype_order(order
, t
) {
2375 list_for_each_entry(page
,
2376 &zone
->free_area
[order
].free_list
[t
], lru
) {
2379 pfn
= page_to_pfn(page
);
2380 for (i
= 0; i
< (1UL << order
); i
++)
2381 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2384 spin_unlock_irqrestore(&zone
->lock
, flags
);
2386 #endif /* CONFIG_PM */
2389 * Free a 0-order page
2390 * cold == true ? free a cold page : free a hot page
2392 void free_hot_cold_page(struct page
*page
, bool cold
)
2394 struct zone
*zone
= page_zone(page
);
2395 struct per_cpu_pages
*pcp
;
2396 unsigned long flags
;
2397 unsigned long pfn
= page_to_pfn(page
);
2400 if (!free_pcp_prepare(page
))
2403 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2404 set_pcppage_migratetype(page
, migratetype
);
2405 local_irq_save(flags
);
2406 __count_vm_event(PGFREE
);
2409 * We only track unmovable, reclaimable and movable on pcp lists.
2410 * Free ISOLATE pages back to the allocator because they are being
2411 * offlined but treat RESERVE as movable pages so we can get those
2412 * areas back if necessary. Otherwise, we may have to free
2413 * excessively into the page allocator
2415 if (migratetype
>= MIGRATE_PCPTYPES
) {
2416 if (unlikely(is_migrate_isolate(migratetype
))) {
2417 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2420 migratetype
= MIGRATE_MOVABLE
;
2423 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2425 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2427 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2429 if (pcp
->count
>= pcp
->high
) {
2430 unsigned long batch
= READ_ONCE(pcp
->batch
);
2431 free_pcppages_bulk(zone
, batch
, pcp
);
2432 pcp
->count
-= batch
;
2436 local_irq_restore(flags
);
2440 * Free a list of 0-order pages
2442 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2444 struct page
*page
, *next
;
2446 list_for_each_entry_safe(page
, next
, list
, lru
) {
2447 trace_mm_page_free_batched(page
, cold
);
2448 free_hot_cold_page(page
, cold
);
2453 * split_page takes a non-compound higher-order page, and splits it into
2454 * n (1<<order) sub-pages: page[0..n]
2455 * Each sub-page must be freed individually.
2457 * Note: this is probably too low level an operation for use in drivers.
2458 * Please consult with lkml before using this in your driver.
2460 void split_page(struct page
*page
, unsigned int order
)
2464 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2465 VM_BUG_ON_PAGE(!page_count(page
), page
);
2467 #ifdef CONFIG_KMEMCHECK
2469 * Split shadow pages too, because free(page[0]) would
2470 * otherwise free the whole shadow.
2472 if (kmemcheck_page_is_tracked(page
))
2473 split_page(virt_to_page(page
[0].shadow
), order
);
2476 for (i
= 1; i
< (1 << order
); i
++)
2477 set_page_refcounted(page
+ i
);
2478 split_page_owner(page
, order
);
2480 EXPORT_SYMBOL_GPL(split_page
);
2482 int __isolate_free_page(struct page
*page
, unsigned int order
)
2484 unsigned long watermark
;
2488 BUG_ON(!PageBuddy(page
));
2490 zone
= page_zone(page
);
2491 mt
= get_pageblock_migratetype(page
);
2493 if (!is_migrate_isolate(mt
)) {
2494 /* Obey watermarks as if the page was being allocated */
2495 watermark
= low_wmark_pages(zone
) + (1 << order
);
2496 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2499 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2502 /* Remove page from free list */
2503 list_del(&page
->lru
);
2504 zone
->free_area
[order
].nr_free
--;
2505 rmv_page_order(page
);
2508 * Set the pageblock if the isolated page is at least half of a
2511 if (order
>= pageblock_order
- 1) {
2512 struct page
*endpage
= page
+ (1 << order
) - 1;
2513 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2514 int mt
= get_pageblock_migratetype(page
);
2515 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2516 set_pageblock_migratetype(page
,
2522 return 1UL << order
;
2526 * Update NUMA hit/miss statistics
2528 * Must be called with interrupts disabled.
2530 * When __GFP_OTHER_NODE is set assume the node of the preferred
2531 * zone is the local node. This is useful for daemons who allocate
2532 * memory on behalf of other processes.
2534 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
,
2538 int local_nid
= numa_node_id();
2539 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2541 if (unlikely(flags
& __GFP_OTHER_NODE
)) {
2542 local_stat
= NUMA_OTHER
;
2543 local_nid
= preferred_zone
->node
;
2546 if (z
->node
== local_nid
) {
2547 __inc_zone_state(z
, NUMA_HIT
);
2548 __inc_zone_state(z
, local_stat
);
2550 __inc_zone_state(z
, NUMA_MISS
);
2551 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2557 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2560 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2561 struct zone
*zone
, unsigned int order
,
2562 gfp_t gfp_flags
, unsigned int alloc_flags
,
2565 unsigned long flags
;
2567 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2569 if (likely(order
== 0)) {
2570 struct per_cpu_pages
*pcp
;
2571 struct list_head
*list
;
2573 local_irq_save(flags
);
2575 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2576 list
= &pcp
->lists
[migratetype
];
2577 if (list_empty(list
)) {
2578 pcp
->count
+= rmqueue_bulk(zone
, 0,
2581 if (unlikely(list_empty(list
)))
2586 page
= list_last_entry(list
, struct page
, lru
);
2588 page
= list_first_entry(list
, struct page
, lru
);
2590 __dec_zone_state(zone
, NR_ALLOC_BATCH
);
2591 list_del(&page
->lru
);
2594 } while (check_new_pcp(page
));
2597 * We most definitely don't want callers attempting to
2598 * allocate greater than order-1 page units with __GFP_NOFAIL.
2600 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2601 spin_lock_irqsave(&zone
->lock
, flags
);
2605 if (alloc_flags
& ALLOC_HARDER
) {
2606 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2608 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2611 page
= __rmqueue(zone
, order
, migratetype
);
2612 } while (page
&& check_new_pages(page
, order
));
2613 spin_unlock(&zone
->lock
);
2616 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2617 __mod_zone_freepage_state(zone
, -(1 << order
),
2618 get_pcppage_migratetype(page
));
2621 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2622 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2623 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2625 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2626 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2627 local_irq_restore(flags
);
2629 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2633 local_irq_restore(flags
);
2637 #ifdef CONFIG_FAIL_PAGE_ALLOC
2640 struct fault_attr attr
;
2642 bool ignore_gfp_highmem
;
2643 bool ignore_gfp_reclaim
;
2645 } fail_page_alloc
= {
2646 .attr
= FAULT_ATTR_INITIALIZER
,
2647 .ignore_gfp_reclaim
= true,
2648 .ignore_gfp_highmem
= true,
2652 static int __init
setup_fail_page_alloc(char *str
)
2654 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2656 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2658 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2660 if (order
< fail_page_alloc
.min_order
)
2662 if (gfp_mask
& __GFP_NOFAIL
)
2664 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2666 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2667 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2670 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2673 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2675 static int __init
fail_page_alloc_debugfs(void)
2677 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2680 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2681 &fail_page_alloc
.attr
);
2683 return PTR_ERR(dir
);
2685 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2686 &fail_page_alloc
.ignore_gfp_reclaim
))
2688 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2689 &fail_page_alloc
.ignore_gfp_highmem
))
2691 if (!debugfs_create_u32("min-order", mode
, dir
,
2692 &fail_page_alloc
.min_order
))
2697 debugfs_remove_recursive(dir
);
2702 late_initcall(fail_page_alloc_debugfs
);
2704 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2706 #else /* CONFIG_FAIL_PAGE_ALLOC */
2708 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2713 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2716 * Return true if free base pages are above 'mark'. For high-order checks it
2717 * will return true of the order-0 watermark is reached and there is at least
2718 * one free page of a suitable size. Checking now avoids taking the zone lock
2719 * to check in the allocation paths if no pages are free.
2721 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2722 int classzone_idx
, unsigned int alloc_flags
,
2727 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2729 /* free_pages may go negative - that's OK */
2730 free_pages
-= (1 << order
) - 1;
2732 if (alloc_flags
& ALLOC_HIGH
)
2736 * If the caller does not have rights to ALLOC_HARDER then subtract
2737 * the high-atomic reserves. This will over-estimate the size of the
2738 * atomic reserve but it avoids a search.
2740 if (likely(!alloc_harder
))
2741 free_pages
-= z
->nr_reserved_highatomic
;
2746 /* If allocation can't use CMA areas don't use free CMA pages */
2747 if (!(alloc_flags
& ALLOC_CMA
))
2748 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2752 * Check watermarks for an order-0 allocation request. If these
2753 * are not met, then a high-order request also cannot go ahead
2754 * even if a suitable page happened to be free.
2756 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2759 /* If this is an order-0 request then the watermark is fine */
2763 /* For a high-order request, check at least one suitable page is free */
2764 for (o
= order
; o
< MAX_ORDER
; o
++) {
2765 struct free_area
*area
= &z
->free_area
[o
];
2774 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2775 if (!list_empty(&area
->free_list
[mt
]))
2780 if ((alloc_flags
& ALLOC_CMA
) &&
2781 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2789 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2790 int classzone_idx
, unsigned int alloc_flags
)
2792 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2793 zone_page_state(z
, NR_FREE_PAGES
));
2796 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
2797 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
2799 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2803 /* If allocation can't use CMA areas don't use free CMA pages */
2804 if (!(alloc_flags
& ALLOC_CMA
))
2805 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2809 * Fast check for order-0 only. If this fails then the reserves
2810 * need to be calculated. There is a corner case where the check
2811 * passes but only the high-order atomic reserve are free. If
2812 * the caller is !atomic then it'll uselessly search the free
2813 * list. That corner case is then slower but it is harmless.
2815 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
2818 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2822 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2823 unsigned long mark
, int classzone_idx
)
2825 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2827 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2828 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2830 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2835 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2837 return local_zone
->node
== zone
->node
;
2840 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2842 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2845 #else /* CONFIG_NUMA */
2846 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2851 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2855 #endif /* CONFIG_NUMA */
2857 static void reset_alloc_batches(struct zone
*preferred_zone
)
2859 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2862 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2863 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2864 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2865 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2866 } while (zone
++ != preferred_zone
);
2870 * get_page_from_freelist goes through the zonelist trying to allocate
2873 static struct page
*
2874 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2875 const struct alloc_context
*ac
)
2877 struct zoneref
*z
= ac
->preferred_zoneref
;
2879 bool fair_skipped
= false;
2880 bool apply_fair
= (alloc_flags
& ALLOC_FAIR
);
2884 * Scan zonelist, looking for a zone with enough free.
2885 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2887 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
2892 if (cpusets_enabled() &&
2893 (alloc_flags
& ALLOC_CPUSET
) &&
2894 !__cpuset_zone_allowed(zone
, gfp_mask
))
2897 * Distribute pages in proportion to the individual
2898 * zone size to ensure fair page aging. The zone a
2899 * page was allocated in should have no effect on the
2900 * time the page has in memory before being reclaimed.
2903 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2904 fair_skipped
= true;
2907 if (!zone_local(ac
->preferred_zoneref
->zone
, zone
)) {
2914 * When allocating a page cache page for writing, we
2915 * want to get it from a node that is within its dirty
2916 * limit, such that no single node holds more than its
2917 * proportional share of globally allowed dirty pages.
2918 * The dirty limits take into account the node's
2919 * lowmem reserves and high watermark so that kswapd
2920 * should be able to balance it without having to
2921 * write pages from its LRU list.
2923 * XXX: For now, allow allocations to potentially
2924 * exceed the per-node dirty limit in the slowpath
2925 * (spread_dirty_pages unset) before going into reclaim,
2926 * which is important when on a NUMA setup the allowed
2927 * nodes are together not big enough to reach the
2928 * global limit. The proper fix for these situations
2929 * will require awareness of nodes in the
2930 * dirty-throttling and the flusher threads.
2932 if (ac
->spread_dirty_pages
&& !node_dirty_ok(zone
->zone_pgdat
))
2935 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2936 if (!zone_watermark_fast(zone
, order
, mark
,
2937 ac_classzone_idx(ac
), alloc_flags
)) {
2940 /* Checked here to keep the fast path fast */
2941 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2942 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2945 if (zone_reclaim_mode
== 0 ||
2946 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
2949 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2951 case ZONE_RECLAIM_NOSCAN
:
2954 case ZONE_RECLAIM_FULL
:
2955 /* scanned but unreclaimable */
2958 /* did we reclaim enough */
2959 if (zone_watermark_ok(zone
, order
, mark
,
2960 ac_classzone_idx(ac
), alloc_flags
))
2968 page
= buffered_rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
2969 gfp_mask
, alloc_flags
, ac
->migratetype
);
2971 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
2974 * If this is a high-order atomic allocation then check
2975 * if the pageblock should be reserved for the future
2977 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2978 reserve_highatomic_pageblock(page
, zone
, order
);
2985 * The first pass makes sure allocations are spread fairly within the
2986 * local node. However, the local node might have free pages left
2987 * after the fairness batches are exhausted, and remote zones haven't
2988 * even been considered yet. Try once more without fairness, and
2989 * include remote zones now, before entering the slowpath and waking
2990 * kswapd: prefer spilling to a remote zone over swapping locally.
2995 fair_skipped
= false;
2996 reset_alloc_batches(ac
->preferred_zoneref
->zone
);
2997 z
= ac
->preferred_zoneref
;
3005 * Large machines with many possible nodes should not always dump per-node
3006 * meminfo in irq context.
3008 static inline bool should_suppress_show_mem(void)
3013 ret
= in_interrupt();
3018 static DEFINE_RATELIMIT_STATE(nopage_rs
,
3019 DEFAULT_RATELIMIT_INTERVAL
,
3020 DEFAULT_RATELIMIT_BURST
);
3022 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
3024 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3026 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
3027 debug_guardpage_minorder() > 0)
3031 * This documents exceptions given to allocations in certain
3032 * contexts that are allowed to allocate outside current's set
3035 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3036 if (test_thread_flag(TIF_MEMDIE
) ||
3037 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3038 filter
&= ~SHOW_MEM_FILTER_NODES
;
3039 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3040 filter
&= ~SHOW_MEM_FILTER_NODES
;
3043 struct va_format vaf
;
3046 va_start(args
, fmt
);
3051 pr_warn("%pV", &vaf
);
3056 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3057 current
->comm
, order
, gfp_mask
, &gfp_mask
);
3059 if (!should_suppress_show_mem())
3063 static inline struct page
*
3064 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3065 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3067 struct oom_control oc
= {
3068 .zonelist
= ac
->zonelist
,
3069 .nodemask
= ac
->nodemask
,
3071 .gfp_mask
= gfp_mask
,
3076 *did_some_progress
= 0;
3079 * Acquire the oom lock. If that fails, somebody else is
3080 * making progress for us.
3082 if (!mutex_trylock(&oom_lock
)) {
3083 *did_some_progress
= 1;
3084 schedule_timeout_uninterruptible(1);
3089 * Go through the zonelist yet one more time, keep very high watermark
3090 * here, this is only to catch a parallel oom killing, we must fail if
3091 * we're still under heavy pressure.
3093 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3094 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3098 if (!(gfp_mask
& __GFP_NOFAIL
)) {
3099 /* Coredumps can quickly deplete all memory reserves */
3100 if (current
->flags
& PF_DUMPCORE
)
3102 /* The OOM killer will not help higher order allocs */
3103 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3105 /* The OOM killer does not needlessly kill tasks for lowmem */
3106 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3108 if (pm_suspended_storage())
3111 * XXX: GFP_NOFS allocations should rather fail than rely on
3112 * other request to make a forward progress.
3113 * We are in an unfortunate situation where out_of_memory cannot
3114 * do much for this context but let's try it to at least get
3115 * access to memory reserved if the current task is killed (see
3116 * out_of_memory). Once filesystems are ready to handle allocation
3117 * failures more gracefully we should just bail out here.
3120 /* The OOM killer may not free memory on a specific node */
3121 if (gfp_mask
& __GFP_THISNODE
)
3124 /* Exhausted what can be done so it's blamo time */
3125 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3126 *did_some_progress
= 1;
3128 if (gfp_mask
& __GFP_NOFAIL
) {
3129 page
= get_page_from_freelist(gfp_mask
, order
,
3130 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
3132 * fallback to ignore cpuset restriction if our nodes
3136 page
= get_page_from_freelist(gfp_mask
, order
,
3137 ALLOC_NO_WATERMARKS
, ac
);
3141 mutex_unlock(&oom_lock
);
3147 * Maximum number of compaction retries wit a progress before OOM
3148 * killer is consider as the only way to move forward.
3150 #define MAX_COMPACT_RETRIES 16
3152 #ifdef CONFIG_COMPACTION
3153 /* Try memory compaction for high-order allocations before reclaim */
3154 static struct page
*
3155 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3156 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3157 enum migrate_mode mode
, enum compact_result
*compact_result
)
3160 int contended_compaction
;
3165 current
->flags
|= PF_MEMALLOC
;
3166 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3167 mode
, &contended_compaction
);
3168 current
->flags
&= ~PF_MEMALLOC
;
3170 if (*compact_result
<= COMPACT_INACTIVE
)
3174 * At least in one zone compaction wasn't deferred or skipped, so let's
3175 * count a compaction stall
3177 count_vm_event(COMPACTSTALL
);
3179 page
= get_page_from_freelist(gfp_mask
, order
,
3180 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3183 struct zone
*zone
= page_zone(page
);
3185 zone
->compact_blockskip_flush
= false;
3186 compaction_defer_reset(zone
, order
, true);
3187 count_vm_event(COMPACTSUCCESS
);
3192 * It's bad if compaction run occurs and fails. The most likely reason
3193 * is that pages exist, but not enough to satisfy watermarks.
3195 count_vm_event(COMPACTFAIL
);
3198 * In all zones where compaction was attempted (and not
3199 * deferred or skipped), lock contention has been detected.
3200 * For THP allocation we do not want to disrupt the others
3201 * so we fallback to base pages instead.
3203 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3204 *compact_result
= COMPACT_CONTENDED
;
3207 * If compaction was aborted due to need_resched(), we do not
3208 * want to further increase allocation latency, unless it is
3209 * khugepaged trying to collapse.
3211 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3212 && !(current
->flags
& PF_KTHREAD
))
3213 *compact_result
= COMPACT_CONTENDED
;
3221 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3222 enum compact_result compact_result
, enum migrate_mode
*migrate_mode
,
3223 int compaction_retries
)
3225 int max_retries
= MAX_COMPACT_RETRIES
;
3231 * compaction considers all the zone as desperately out of memory
3232 * so it doesn't really make much sense to retry except when the
3233 * failure could be caused by weak migration mode.
3235 if (compaction_failed(compact_result
)) {
3236 if (*migrate_mode
== MIGRATE_ASYNC
) {
3237 *migrate_mode
= MIGRATE_SYNC_LIGHT
;
3244 * make sure the compaction wasn't deferred or didn't bail out early
3245 * due to locks contention before we declare that we should give up.
3246 * But do not retry if the given zonelist is not suitable for
3249 if (compaction_withdrawn(compact_result
))
3250 return compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3253 * !costly requests are much more important than __GFP_REPEAT
3254 * costly ones because they are de facto nofail and invoke OOM
3255 * killer to move on while costly can fail and users are ready
3256 * to cope with that. 1/4 retries is rather arbitrary but we
3257 * would need much more detailed feedback from compaction to
3258 * make a better decision.
3260 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3262 if (compaction_retries
<= max_retries
)
3268 static inline struct page
*
3269 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3270 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3271 enum migrate_mode mode
, enum compact_result
*compact_result
)
3273 *compact_result
= COMPACT_SKIPPED
;
3278 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3279 enum compact_result compact_result
,
3280 enum migrate_mode
*migrate_mode
,
3281 int compaction_retries
)
3286 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3290 * There are setups with compaction disabled which would prefer to loop
3291 * inside the allocator rather than hit the oom killer prematurely.
3292 * Let's give them a good hope and keep retrying while the order-0
3293 * watermarks are OK.
3295 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3297 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3298 ac_classzone_idx(ac
), alloc_flags
))
3303 #endif /* CONFIG_COMPACTION */
3305 /* Perform direct synchronous page reclaim */
3307 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3308 const struct alloc_context
*ac
)
3310 struct reclaim_state reclaim_state
;
3315 /* We now go into synchronous reclaim */
3316 cpuset_memory_pressure_bump();
3317 current
->flags
|= PF_MEMALLOC
;
3318 lockdep_set_current_reclaim_state(gfp_mask
);
3319 reclaim_state
.reclaimed_slab
= 0;
3320 current
->reclaim_state
= &reclaim_state
;
3322 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3325 current
->reclaim_state
= NULL
;
3326 lockdep_clear_current_reclaim_state();
3327 current
->flags
&= ~PF_MEMALLOC
;
3334 /* The really slow allocator path where we enter direct reclaim */
3335 static inline struct page
*
3336 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3337 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3338 unsigned long *did_some_progress
)
3340 struct page
*page
= NULL
;
3341 bool drained
= false;
3343 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3344 if (unlikely(!(*did_some_progress
)))
3348 page
= get_page_from_freelist(gfp_mask
, order
,
3349 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3352 * If an allocation failed after direct reclaim, it could be because
3353 * pages are pinned on the per-cpu lists or in high alloc reserves.
3354 * Shrink them them and try again
3356 if (!page
&& !drained
) {
3357 unreserve_highatomic_pageblock(ac
);
3358 drain_all_pages(NULL
);
3366 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3371 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3372 ac
->high_zoneidx
, ac
->nodemask
)
3373 wakeup_kswapd(zone
, order
, ac_classzone_idx(ac
));
3376 static inline unsigned int
3377 gfp_to_alloc_flags(gfp_t gfp_mask
)
3379 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3381 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3382 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3385 * The caller may dip into page reserves a bit more if the caller
3386 * cannot run direct reclaim, or if the caller has realtime scheduling
3387 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3388 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3390 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3392 if (gfp_mask
& __GFP_ATOMIC
) {
3394 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3395 * if it can't schedule.
3397 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3398 alloc_flags
|= ALLOC_HARDER
;
3400 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3401 * comment for __cpuset_node_allowed().
3403 alloc_flags
&= ~ALLOC_CPUSET
;
3404 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3405 alloc_flags
|= ALLOC_HARDER
;
3407 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3408 if (gfp_mask
& __GFP_MEMALLOC
)
3409 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3410 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3411 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3412 else if (!in_interrupt() &&
3413 ((current
->flags
& PF_MEMALLOC
) ||
3414 unlikely(test_thread_flag(TIF_MEMDIE
))))
3415 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3418 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3419 alloc_flags
|= ALLOC_CMA
;
3424 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3426 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3429 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3431 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3435 * Maximum number of reclaim retries without any progress before OOM killer
3436 * is consider as the only way to move forward.
3438 #define MAX_RECLAIM_RETRIES 16
3441 * Checks whether it makes sense to retry the reclaim to make a forward progress
3442 * for the given allocation request.
3443 * The reclaim feedback represented by did_some_progress (any progress during
3444 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3445 * any progress in a row) is considered as well as the reclaimable pages on the
3446 * applicable zone list (with a backoff mechanism which is a function of
3447 * no_progress_loops).
3449 * Returns true if a retry is viable or false to enter the oom path.
3452 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3453 struct alloc_context
*ac
, int alloc_flags
,
3454 bool did_some_progress
, int no_progress_loops
)
3460 * Make sure we converge to OOM if we cannot make any progress
3461 * several times in the row.
3463 if (no_progress_loops
> MAX_RECLAIM_RETRIES
)
3467 * Keep reclaiming pages while there is a chance this will lead somewhere.
3468 * If none of the target zones can satisfy our allocation request even
3469 * if all reclaimable pages are considered then we are screwed and have
3472 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3474 unsigned long available
;
3475 unsigned long reclaimable
;
3477 available
= reclaimable
= zone_reclaimable_pages(zone
);
3478 available
-= DIV_ROUND_UP(no_progress_loops
* available
,
3479 MAX_RECLAIM_RETRIES
);
3480 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3483 * Would the allocation succeed if we reclaimed the whole
3486 if (__zone_watermark_ok(zone
, order
, min_wmark_pages(zone
),
3487 ac_classzone_idx(ac
), alloc_flags
, available
)) {
3489 * If we didn't make any progress and have a lot of
3490 * dirty + writeback pages then we should wait for
3491 * an IO to complete to slow down the reclaim and
3492 * prevent from pre mature OOM
3494 if (!did_some_progress
) {
3495 unsigned long writeback
;
3496 unsigned long dirty
;
3498 writeback
= zone_page_state_snapshot(zone
,
3500 dirty
= zone_page_state_snapshot(zone
, NR_FILE_DIRTY
);
3502 if (2*(writeback
+ dirty
) > reclaimable
) {
3503 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3509 * Memory allocation/reclaim might be called from a WQ
3510 * context and the current implementation of the WQ
3511 * concurrency control doesn't recognize that
3512 * a particular WQ is congested if the worker thread is
3513 * looping without ever sleeping. Therefore we have to
3514 * do a short sleep here rather than calling
3517 if (current
->flags
& PF_WQ_WORKER
)
3518 schedule_timeout_uninterruptible(1);
3529 static inline struct page
*
3530 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3531 struct alloc_context
*ac
)
3533 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3534 struct page
*page
= NULL
;
3535 unsigned int alloc_flags
;
3536 unsigned long did_some_progress
;
3537 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3538 enum compact_result compact_result
;
3539 int compaction_retries
= 0;
3540 int no_progress_loops
= 0;
3543 * In the slowpath, we sanity check order to avoid ever trying to
3544 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3545 * be using allocators in order of preference for an area that is
3548 if (order
>= MAX_ORDER
) {
3549 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3554 * We also sanity check to catch abuse of atomic reserves being used by
3555 * callers that are not in atomic context.
3557 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3558 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3559 gfp_mask
&= ~__GFP_ATOMIC
;
3562 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3563 wake_all_kswapds(order
, ac
);
3566 * OK, we're below the kswapd watermark and have kicked background
3567 * reclaim. Now things get more complex, so set up alloc_flags according
3568 * to how we want to proceed.
3570 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3573 * Reset the zonelist iterators if memory policies can be ignored.
3574 * These allocations are high priority and system rather than user
3577 if ((alloc_flags
& ALLOC_NO_WATERMARKS
) || !(alloc_flags
& ALLOC_CPUSET
)) {
3578 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3579 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3580 ac
->high_zoneidx
, ac
->nodemask
);
3583 /* This is the last chance, in general, before the goto nopage. */
3584 page
= get_page_from_freelist(gfp_mask
, order
,
3585 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3589 /* Allocate without watermarks if the context allows */
3590 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3591 page
= get_page_from_freelist(gfp_mask
, order
,
3592 ALLOC_NO_WATERMARKS
, ac
);
3597 /* Caller is not willing to reclaim, we can't balance anything */
3598 if (!can_direct_reclaim
) {
3600 * All existing users of the __GFP_NOFAIL are blockable, so warn
3601 * of any new users that actually allow this type of allocation
3604 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3608 /* Avoid recursion of direct reclaim */
3609 if (current
->flags
& PF_MEMALLOC
) {
3611 * __GFP_NOFAIL request from this context is rather bizarre
3612 * because we cannot reclaim anything and only can loop waiting
3613 * for somebody to do a work for us.
3615 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3622 /* Avoid allocations with no watermarks from looping endlessly */
3623 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3627 * Try direct compaction. The first pass is asynchronous. Subsequent
3628 * attempts after direct reclaim are synchronous
3630 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3636 /* Checks for THP-specific high-order allocations */
3637 if (is_thp_gfp_mask(gfp_mask
)) {
3639 * If compaction is deferred for high-order allocations, it is
3640 * because sync compaction recently failed. If this is the case
3641 * and the caller requested a THP allocation, we do not want
3642 * to heavily disrupt the system, so we fail the allocation
3643 * instead of entering direct reclaim.
3645 if (compact_result
== COMPACT_DEFERRED
)
3649 * Compaction is contended so rather back off than cause
3652 if(compact_result
== COMPACT_CONTENDED
)
3656 if (order
&& compaction_made_progress(compact_result
))
3657 compaction_retries
++;
3659 /* Try direct reclaim and then allocating */
3660 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3661 &did_some_progress
);
3665 /* Do not loop if specifically requested */
3666 if (gfp_mask
& __GFP_NORETRY
)
3670 * Do not retry costly high order allocations unless they are
3673 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_REPEAT
))
3677 * Costly allocations might have made a progress but this doesn't mean
3678 * their order will become available due to high fragmentation so
3679 * always increment the no progress counter for them
3681 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3682 no_progress_loops
= 0;
3684 no_progress_loops
++;
3686 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3687 did_some_progress
> 0, no_progress_loops
))
3691 * It doesn't make any sense to retry for the compaction if the order-0
3692 * reclaim is not able to make any progress because the current
3693 * implementation of the compaction depends on the sufficient amount
3694 * of free memory (see __compaction_suitable)
3696 if (did_some_progress
> 0 &&
3697 should_compact_retry(ac
, order
, alloc_flags
,
3698 compact_result
, &migration_mode
,
3699 compaction_retries
))
3702 /* Reclaim has failed us, start killing things */
3703 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3707 /* Retry as long as the OOM killer is making progress */
3708 if (did_some_progress
) {
3709 no_progress_loops
= 0;
3715 * High-order allocations do not necessarily loop after direct reclaim
3716 * and reclaim/compaction depends on compaction being called after
3717 * reclaim so call directly if necessary.
3718 * It can become very expensive to allocate transparent hugepages at
3719 * fault, so use asynchronous memory compaction for THP unless it is
3720 * khugepaged trying to collapse. All other requests should tolerate
3721 * at least light sync migration.
3723 if (is_thp_gfp_mask(gfp_mask
) && !(current
->flags
& PF_KTHREAD
))
3724 migration_mode
= MIGRATE_ASYNC
;
3726 migration_mode
= MIGRATE_SYNC_LIGHT
;
3727 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3733 warn_alloc_failed(gfp_mask
, order
, NULL
);
3739 * This is the 'heart' of the zoned buddy allocator.
3742 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3743 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3746 unsigned int cpuset_mems_cookie
;
3747 unsigned int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_FAIR
;
3748 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
3749 struct alloc_context ac
= {
3750 .high_zoneidx
= gfp_zone(gfp_mask
),
3751 .zonelist
= zonelist
,
3752 .nodemask
= nodemask
,
3753 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3756 if (cpusets_enabled()) {
3757 alloc_mask
|= __GFP_HARDWALL
;
3758 alloc_flags
|= ALLOC_CPUSET
;
3760 ac
.nodemask
= &cpuset_current_mems_allowed
;
3763 gfp_mask
&= gfp_allowed_mask
;
3765 lockdep_trace_alloc(gfp_mask
);
3767 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3769 if (should_fail_alloc_page(gfp_mask
, order
))
3773 * Check the zones suitable for the gfp_mask contain at least one
3774 * valid zone. It's possible to have an empty zonelist as a result
3775 * of __GFP_THISNODE and a memoryless node
3777 if (unlikely(!zonelist
->_zonerefs
->zone
))
3780 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3781 alloc_flags
|= ALLOC_CMA
;
3784 cpuset_mems_cookie
= read_mems_allowed_begin();
3786 /* Dirty zone balancing only done in the fast path */
3787 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3790 * The preferred zone is used for statistics but crucially it is
3791 * also used as the starting point for the zonelist iterator. It
3792 * may get reset for allocations that ignore memory policies.
3794 ac
.preferred_zoneref
= first_zones_zonelist(ac
.zonelist
,
3795 ac
.high_zoneidx
, ac
.nodemask
);
3796 if (!ac
.preferred_zoneref
) {
3801 /* First allocation attempt */
3802 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3807 * Runtime PM, block IO and its error handling path can deadlock
3808 * because I/O on the device might not complete.
3810 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3811 ac
.spread_dirty_pages
= false;
3814 * Restore the original nodemask if it was potentially replaced with
3815 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3817 if (cpusets_enabled())
3818 ac
.nodemask
= nodemask
;
3819 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3823 * When updating a task's mems_allowed, it is possible to race with
3824 * parallel threads in such a way that an allocation can fail while
3825 * the mask is being updated. If a page allocation is about to fail,
3826 * check if the cpuset changed during allocation and if so, retry.
3828 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
))) {
3829 alloc_mask
= gfp_mask
;
3834 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
) {
3835 if (unlikely(memcg_kmem_charge(page
, gfp_mask
, order
))) {
3836 __free_pages(page
, order
);
3839 __SetPageKmemcg(page
);
3842 if (kmemcheck_enabled
&& page
)
3843 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3845 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3849 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3852 * Common helper functions.
3854 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3859 * __get_free_pages() returns a 32-bit address, which cannot represent
3862 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3864 page
= alloc_pages(gfp_mask
, order
);
3867 return (unsigned long) page_address(page
);
3869 EXPORT_SYMBOL(__get_free_pages
);
3871 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3873 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3875 EXPORT_SYMBOL(get_zeroed_page
);
3877 void __free_pages(struct page
*page
, unsigned int order
)
3879 if (put_page_testzero(page
)) {
3881 free_hot_cold_page(page
, false);
3883 __free_pages_ok(page
, order
);
3887 EXPORT_SYMBOL(__free_pages
);
3889 void free_pages(unsigned long addr
, unsigned int order
)
3892 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3893 __free_pages(virt_to_page((void *)addr
), order
);
3897 EXPORT_SYMBOL(free_pages
);
3901 * An arbitrary-length arbitrary-offset area of memory which resides
3902 * within a 0 or higher order page. Multiple fragments within that page
3903 * are individually refcounted, in the page's reference counter.
3905 * The page_frag functions below provide a simple allocation framework for
3906 * page fragments. This is used by the network stack and network device
3907 * drivers to provide a backing region of memory for use as either an
3908 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3910 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3913 struct page
*page
= NULL
;
3914 gfp_t gfp
= gfp_mask
;
3916 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3917 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3919 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3920 PAGE_FRAG_CACHE_MAX_ORDER
);
3921 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3923 if (unlikely(!page
))
3924 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3926 nc
->va
= page
? page_address(page
) : NULL
;
3931 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3932 unsigned int fragsz
, gfp_t gfp_mask
)
3934 unsigned int size
= PAGE_SIZE
;
3938 if (unlikely(!nc
->va
)) {
3940 page
= __page_frag_refill(nc
, gfp_mask
);
3944 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3945 /* if size can vary use size else just use PAGE_SIZE */
3948 /* Even if we own the page, we do not use atomic_set().
3949 * This would break get_page_unless_zero() users.
3951 page_ref_add(page
, size
- 1);
3953 /* reset page count bias and offset to start of new frag */
3954 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3955 nc
->pagecnt_bias
= size
;
3959 offset
= nc
->offset
- fragsz
;
3960 if (unlikely(offset
< 0)) {
3961 page
= virt_to_page(nc
->va
);
3963 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3966 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3967 /* if size can vary use size else just use PAGE_SIZE */
3970 /* OK, page count is 0, we can safely set it */
3971 set_page_count(page
, size
);
3973 /* reset page count bias and offset to start of new frag */
3974 nc
->pagecnt_bias
= size
;
3975 offset
= size
- fragsz
;
3979 nc
->offset
= offset
;
3981 return nc
->va
+ offset
;
3983 EXPORT_SYMBOL(__alloc_page_frag
);
3986 * Frees a page fragment allocated out of either a compound or order 0 page.
3988 void __free_page_frag(void *addr
)
3990 struct page
*page
= virt_to_head_page(addr
);
3992 if (unlikely(put_page_testzero(page
)))
3993 __free_pages_ok(page
, compound_order(page
));
3995 EXPORT_SYMBOL(__free_page_frag
);
3997 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4001 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4002 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4004 split_page(virt_to_page((void *)addr
), order
);
4005 while (used
< alloc_end
) {
4010 return (void *)addr
;
4014 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4015 * @size: the number of bytes to allocate
4016 * @gfp_mask: GFP flags for the allocation
4018 * This function is similar to alloc_pages(), except that it allocates the
4019 * minimum number of pages to satisfy the request. alloc_pages() can only
4020 * allocate memory in power-of-two pages.
4022 * This function is also limited by MAX_ORDER.
4024 * Memory allocated by this function must be released by free_pages_exact().
4026 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4028 unsigned int order
= get_order(size
);
4031 addr
= __get_free_pages(gfp_mask
, order
);
4032 return make_alloc_exact(addr
, order
, size
);
4034 EXPORT_SYMBOL(alloc_pages_exact
);
4037 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4039 * @nid: the preferred node ID where memory should be allocated
4040 * @size: the number of bytes to allocate
4041 * @gfp_mask: GFP flags for the allocation
4043 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4046 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4048 unsigned int order
= get_order(size
);
4049 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4052 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4056 * free_pages_exact - release memory allocated via alloc_pages_exact()
4057 * @virt: the value returned by alloc_pages_exact.
4058 * @size: size of allocation, same value as passed to alloc_pages_exact().
4060 * Release the memory allocated by a previous call to alloc_pages_exact.
4062 void free_pages_exact(void *virt
, size_t size
)
4064 unsigned long addr
= (unsigned long)virt
;
4065 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4067 while (addr
< end
) {
4072 EXPORT_SYMBOL(free_pages_exact
);
4075 * nr_free_zone_pages - count number of pages beyond high watermark
4076 * @offset: The zone index of the highest zone
4078 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4079 * high watermark within all zones at or below a given zone index. For each
4080 * zone, the number of pages is calculated as:
4081 * managed_pages - high_pages
4083 static unsigned long nr_free_zone_pages(int offset
)
4088 /* Just pick one node, since fallback list is circular */
4089 unsigned long sum
= 0;
4091 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4093 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4094 unsigned long size
= zone
->managed_pages
;
4095 unsigned long high
= high_wmark_pages(zone
);
4104 * nr_free_buffer_pages - count number of pages beyond high watermark
4106 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4107 * watermark within ZONE_DMA and ZONE_NORMAL.
4109 unsigned long nr_free_buffer_pages(void)
4111 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4113 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4116 * nr_free_pagecache_pages - count number of pages beyond high watermark
4118 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4119 * high watermark within all zones.
4121 unsigned long nr_free_pagecache_pages(void)
4123 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4126 static inline void show_node(struct zone
*zone
)
4128 if (IS_ENABLED(CONFIG_NUMA
))
4129 printk("Node %d ", zone_to_nid(zone
));
4132 long si_mem_available(void)
4135 unsigned long pagecache
;
4136 unsigned long wmark_low
= 0;
4137 unsigned long pages
[NR_LRU_LISTS
];
4141 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4142 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
4145 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4148 * Estimate the amount of memory available for userspace allocations,
4149 * without causing swapping.
4151 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4154 * Not all the page cache can be freed, otherwise the system will
4155 * start swapping. Assume at least half of the page cache, or the
4156 * low watermark worth of cache, needs to stay.
4158 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4159 pagecache
-= min(pagecache
/ 2, wmark_low
);
4160 available
+= pagecache
;
4163 * Part of the reclaimable slab consists of items that are in use,
4164 * and cannot be freed. Cap this estimate at the low watermark.
4166 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4167 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4173 EXPORT_SYMBOL_GPL(si_mem_available
);
4175 void si_meminfo(struct sysinfo
*val
)
4177 val
->totalram
= totalram_pages
;
4178 val
->sharedram
= global_page_state(NR_SHMEM
);
4179 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4180 val
->bufferram
= nr_blockdev_pages();
4181 val
->totalhigh
= totalhigh_pages
;
4182 val
->freehigh
= nr_free_highpages();
4183 val
->mem_unit
= PAGE_SIZE
;
4186 EXPORT_SYMBOL(si_meminfo
);
4189 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4191 int zone_type
; /* needs to be signed */
4192 unsigned long managed_pages
= 0;
4193 unsigned long managed_highpages
= 0;
4194 unsigned long free_highpages
= 0;
4195 pg_data_t
*pgdat
= NODE_DATA(nid
);
4197 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4198 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4199 val
->totalram
= managed_pages
;
4200 val
->sharedram
= sum_zone_node_page_state(nid
, NR_SHMEM
);
4201 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4202 #ifdef CONFIG_HIGHMEM
4203 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4204 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4206 if (is_highmem(zone
)) {
4207 managed_highpages
+= zone
->managed_pages
;
4208 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4211 val
->totalhigh
= managed_highpages
;
4212 val
->freehigh
= free_highpages
;
4214 val
->totalhigh
= managed_highpages
;
4215 val
->freehigh
= free_highpages
;
4217 val
->mem_unit
= PAGE_SIZE
;
4222 * Determine whether the node should be displayed or not, depending on whether
4223 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4225 bool skip_free_areas_node(unsigned int flags
, int nid
)
4228 unsigned int cpuset_mems_cookie
;
4230 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4234 cpuset_mems_cookie
= read_mems_allowed_begin();
4235 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
4236 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
4241 #define K(x) ((x) << (PAGE_SHIFT-10))
4243 static void show_migration_types(unsigned char type
)
4245 static const char types
[MIGRATE_TYPES
] = {
4246 [MIGRATE_UNMOVABLE
] = 'U',
4247 [MIGRATE_MOVABLE
] = 'M',
4248 [MIGRATE_RECLAIMABLE
] = 'E',
4249 [MIGRATE_HIGHATOMIC
] = 'H',
4251 [MIGRATE_CMA
] = 'C',
4253 #ifdef CONFIG_MEMORY_ISOLATION
4254 [MIGRATE_ISOLATE
] = 'I',
4257 char tmp
[MIGRATE_TYPES
+ 1];
4261 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4262 if (type
& (1 << i
))
4267 printk("(%s) ", tmp
);
4271 * Show free area list (used inside shift_scroll-lock stuff)
4272 * We also calculate the percentage fragmentation. We do this by counting the
4273 * memory on each free list with the exception of the first item on the list.
4276 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4279 void show_free_areas(unsigned int filter
)
4281 unsigned long free_pcp
= 0;
4286 for_each_populated_zone(zone
) {
4287 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4290 for_each_online_cpu(cpu
)
4291 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4294 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4295 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4296 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4297 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4298 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4299 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4300 " anon_thp: %lu shmem_thp: %lu shmem_pmdmapped: %lu\n"
4302 " free:%lu free_pcp:%lu free_cma:%lu\n",
4303 global_node_page_state(NR_ACTIVE_ANON
),
4304 global_node_page_state(NR_INACTIVE_ANON
),
4305 global_node_page_state(NR_ISOLATED_ANON
),
4306 global_node_page_state(NR_ACTIVE_FILE
),
4307 global_node_page_state(NR_INACTIVE_FILE
),
4308 global_node_page_state(NR_ISOLATED_FILE
),
4309 global_node_page_state(NR_UNEVICTABLE
),
4310 global_page_state(NR_FILE_DIRTY
),
4311 global_page_state(NR_WRITEBACK
),
4312 global_page_state(NR_UNSTABLE_NFS
),
4313 global_page_state(NR_SLAB_RECLAIMABLE
),
4314 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4315 global_node_page_state(NR_FILE_MAPPED
),
4316 global_page_state(NR_SHMEM
),
4317 global_page_state(NR_PAGETABLE
),
4318 global_page_state(NR_BOUNCE
),
4319 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4320 global_page_state(NR_ANON_THPS
) * HPAGE_PMD_NR
,
4321 global_page_state(NR_SHMEM_THPS
) * HPAGE_PMD_NR
,
4322 global_page_state(NR_SHMEM_PMDMAPPED
) * HPAGE_PMD_NR
,
4324 global_page_state(NR_FREE_PAGES
),
4326 global_page_state(NR_FREE_CMA_PAGES
));
4328 for_each_online_pgdat(pgdat
) {
4330 " active_anon:%lukB"
4331 " inactive_anon:%lukB"
4332 " active_file:%lukB"
4333 " inactive_file:%lukB"
4334 " unevictable:%lukB"
4335 " isolated(anon):%lukB"
4336 " isolated(file):%lukB"
4338 " all_unreclaimable? %s"
4341 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4342 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4343 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4344 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4345 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4346 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4347 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4348 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4349 !pgdat_reclaimable(pgdat
) ? "yes" : "no");
4352 for_each_populated_zone(zone
) {
4355 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4359 for_each_online_cpu(cpu
)
4360 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4374 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4376 " shmem_pmdmapped: %lukB"
4379 " slab_reclaimable:%lukB"
4380 " slab_unreclaimable:%lukB"
4381 " kernel_stack:%lukB"
4388 " writeback_tmp:%lukB"
4389 " node_pages_scanned:%lu"
4392 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4393 K(min_wmark_pages(zone
)),
4394 K(low_wmark_pages(zone
)),
4395 K(high_wmark_pages(zone
)),
4396 K(zone
->present_pages
),
4397 K(zone
->managed_pages
),
4398 K(zone_page_state(zone
, NR_MLOCK
)),
4399 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
4400 K(zone_page_state(zone
, NR_WRITEBACK
)),
4401 K(zone_page_state(zone
, NR_SHMEM
)),
4402 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4403 K(zone_page_state(zone
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4404 K(zone_page_state(zone
, NR_SHMEM_PMDMAPPED
)
4406 K(zone_page_state(zone
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4408 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
4409 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
4410 zone_page_state(zone
, NR_KERNEL_STACK
) *
4412 K(zone_page_state(zone
, NR_PAGETABLE
)),
4413 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
4414 K(zone_page_state(zone
, NR_BOUNCE
)),
4416 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4417 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
4418 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
4419 K(node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
)));
4420 printk("lowmem_reserve[]:");
4421 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4422 printk(" %ld", zone
->lowmem_reserve
[i
]);
4426 for_each_populated_zone(zone
) {
4428 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4429 unsigned char types
[MAX_ORDER
];
4431 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4434 printk("%s: ", zone
->name
);
4436 spin_lock_irqsave(&zone
->lock
, flags
);
4437 for (order
= 0; order
< MAX_ORDER
; order
++) {
4438 struct free_area
*area
= &zone
->free_area
[order
];
4441 nr
[order
] = area
->nr_free
;
4442 total
+= nr
[order
] << order
;
4445 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4446 if (!list_empty(&area
->free_list
[type
]))
4447 types
[order
] |= 1 << type
;
4450 spin_unlock_irqrestore(&zone
->lock
, flags
);
4451 for (order
= 0; order
< MAX_ORDER
; order
++) {
4452 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4454 show_migration_types(types
[order
]);
4456 printk("= %lukB\n", K(total
));
4459 hugetlb_show_meminfo();
4461 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4463 show_swap_cache_info();
4466 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4468 zoneref
->zone
= zone
;
4469 zoneref
->zone_idx
= zone_idx(zone
);
4473 * Builds allocation fallback zone lists.
4475 * Add all populated zones of a node to the zonelist.
4477 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4481 enum zone_type zone_type
= MAX_NR_ZONES
;
4485 zone
= pgdat
->node_zones
+ zone_type
;
4486 if (populated_zone(zone
)) {
4487 zoneref_set_zone(zone
,
4488 &zonelist
->_zonerefs
[nr_zones
++]);
4489 check_highest_zone(zone_type
);
4491 } while (zone_type
);
4499 * 0 = automatic detection of better ordering.
4500 * 1 = order by ([node] distance, -zonetype)
4501 * 2 = order by (-zonetype, [node] distance)
4503 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4504 * the same zonelist. So only NUMA can configure this param.
4506 #define ZONELIST_ORDER_DEFAULT 0
4507 #define ZONELIST_ORDER_NODE 1
4508 #define ZONELIST_ORDER_ZONE 2
4510 /* zonelist order in the kernel.
4511 * set_zonelist_order() will set this to NODE or ZONE.
4513 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4514 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4518 /* The value user specified ....changed by config */
4519 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4520 /* string for sysctl */
4521 #define NUMA_ZONELIST_ORDER_LEN 16
4522 char numa_zonelist_order
[16] = "default";
4525 * interface for configure zonelist ordering.
4526 * command line option "numa_zonelist_order"
4527 * = "[dD]efault - default, automatic configuration.
4528 * = "[nN]ode - order by node locality, then by zone within node
4529 * = "[zZ]one - order by zone, then by locality within zone
4532 static int __parse_numa_zonelist_order(char *s
)
4534 if (*s
== 'd' || *s
== 'D') {
4535 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4536 } else if (*s
== 'n' || *s
== 'N') {
4537 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4538 } else if (*s
== 'z' || *s
== 'Z') {
4539 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4541 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4547 static __init
int setup_numa_zonelist_order(char *s
)
4554 ret
= __parse_numa_zonelist_order(s
);
4556 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4560 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4563 * sysctl handler for numa_zonelist_order
4565 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4566 void __user
*buffer
, size_t *length
,
4569 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4571 static DEFINE_MUTEX(zl_order_mutex
);
4573 mutex_lock(&zl_order_mutex
);
4575 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4579 strcpy(saved_string
, (char *)table
->data
);
4581 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4585 int oldval
= user_zonelist_order
;
4587 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4590 * bogus value. restore saved string
4592 strncpy((char *)table
->data
, saved_string
,
4593 NUMA_ZONELIST_ORDER_LEN
);
4594 user_zonelist_order
= oldval
;
4595 } else if (oldval
!= user_zonelist_order
) {
4596 mutex_lock(&zonelists_mutex
);
4597 build_all_zonelists(NULL
, NULL
);
4598 mutex_unlock(&zonelists_mutex
);
4602 mutex_unlock(&zl_order_mutex
);
4607 #define MAX_NODE_LOAD (nr_online_nodes)
4608 static int node_load
[MAX_NUMNODES
];
4611 * find_next_best_node - find the next node that should appear in a given node's fallback list
4612 * @node: node whose fallback list we're appending
4613 * @used_node_mask: nodemask_t of already used nodes
4615 * We use a number of factors to determine which is the next node that should
4616 * appear on a given node's fallback list. The node should not have appeared
4617 * already in @node's fallback list, and it should be the next closest node
4618 * according to the distance array (which contains arbitrary distance values
4619 * from each node to each node in the system), and should also prefer nodes
4620 * with no CPUs, since presumably they'll have very little allocation pressure
4621 * on them otherwise.
4622 * It returns -1 if no node is found.
4624 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4627 int min_val
= INT_MAX
;
4628 int best_node
= NUMA_NO_NODE
;
4629 const struct cpumask
*tmp
= cpumask_of_node(0);
4631 /* Use the local node if we haven't already */
4632 if (!node_isset(node
, *used_node_mask
)) {
4633 node_set(node
, *used_node_mask
);
4637 for_each_node_state(n
, N_MEMORY
) {
4639 /* Don't want a node to appear more than once */
4640 if (node_isset(n
, *used_node_mask
))
4643 /* Use the distance array to find the distance */
4644 val
= node_distance(node
, n
);
4646 /* Penalize nodes under us ("prefer the next node") */
4649 /* Give preference to headless and unused nodes */
4650 tmp
= cpumask_of_node(n
);
4651 if (!cpumask_empty(tmp
))
4652 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4654 /* Slight preference for less loaded node */
4655 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4656 val
+= node_load
[n
];
4658 if (val
< min_val
) {
4665 node_set(best_node
, *used_node_mask
);
4672 * Build zonelists ordered by node and zones within node.
4673 * This results in maximum locality--normal zone overflows into local
4674 * DMA zone, if any--but risks exhausting DMA zone.
4676 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4679 struct zonelist
*zonelist
;
4681 zonelist
= &pgdat
->node_zonelists
[0];
4682 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4684 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4685 zonelist
->_zonerefs
[j
].zone
= NULL
;
4686 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4690 * Build gfp_thisnode zonelists
4692 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4695 struct zonelist
*zonelist
;
4697 zonelist
= &pgdat
->node_zonelists
[1];
4698 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4699 zonelist
->_zonerefs
[j
].zone
= NULL
;
4700 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4704 * Build zonelists ordered by zone and nodes within zones.
4705 * This results in conserving DMA zone[s] until all Normal memory is
4706 * exhausted, but results in overflowing to remote node while memory
4707 * may still exist in local DMA zone.
4709 static int node_order
[MAX_NUMNODES
];
4711 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4714 int zone_type
; /* needs to be signed */
4716 struct zonelist
*zonelist
;
4718 zonelist
= &pgdat
->node_zonelists
[0];
4720 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4721 for (j
= 0; j
< nr_nodes
; j
++) {
4722 node
= node_order
[j
];
4723 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4724 if (populated_zone(z
)) {
4726 &zonelist
->_zonerefs
[pos
++]);
4727 check_highest_zone(zone_type
);
4731 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4732 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4735 #if defined(CONFIG_64BIT)
4737 * Devices that require DMA32/DMA are relatively rare and do not justify a
4738 * penalty to every machine in case the specialised case applies. Default
4739 * to Node-ordering on 64-bit NUMA machines
4741 static int default_zonelist_order(void)
4743 return ZONELIST_ORDER_NODE
;
4747 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4748 * by the kernel. If processes running on node 0 deplete the low memory zone
4749 * then reclaim will occur more frequency increasing stalls and potentially
4750 * be easier to OOM if a large percentage of the zone is under writeback or
4751 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4752 * Hence, default to zone ordering on 32-bit.
4754 static int default_zonelist_order(void)
4756 return ZONELIST_ORDER_ZONE
;
4758 #endif /* CONFIG_64BIT */
4760 static void set_zonelist_order(void)
4762 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4763 current_zonelist_order
= default_zonelist_order();
4765 current_zonelist_order
= user_zonelist_order
;
4768 static void build_zonelists(pg_data_t
*pgdat
)
4771 nodemask_t used_mask
;
4772 int local_node
, prev_node
;
4773 struct zonelist
*zonelist
;
4774 unsigned int order
= current_zonelist_order
;
4776 /* initialize zonelists */
4777 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4778 zonelist
= pgdat
->node_zonelists
+ i
;
4779 zonelist
->_zonerefs
[0].zone
= NULL
;
4780 zonelist
->_zonerefs
[0].zone_idx
= 0;
4783 /* NUMA-aware ordering of nodes */
4784 local_node
= pgdat
->node_id
;
4785 load
= nr_online_nodes
;
4786 prev_node
= local_node
;
4787 nodes_clear(used_mask
);
4789 memset(node_order
, 0, sizeof(node_order
));
4792 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4794 * We don't want to pressure a particular node.
4795 * So adding penalty to the first node in same
4796 * distance group to make it round-robin.
4798 if (node_distance(local_node
, node
) !=
4799 node_distance(local_node
, prev_node
))
4800 node_load
[node
] = load
;
4804 if (order
== ZONELIST_ORDER_NODE
)
4805 build_zonelists_in_node_order(pgdat
, node
);
4807 node_order
[i
++] = node
; /* remember order */
4810 if (order
== ZONELIST_ORDER_ZONE
) {
4811 /* calculate node order -- i.e., DMA last! */
4812 build_zonelists_in_zone_order(pgdat
, i
);
4815 build_thisnode_zonelists(pgdat
);
4818 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4820 * Return node id of node used for "local" allocations.
4821 * I.e., first node id of first zone in arg node's generic zonelist.
4822 * Used for initializing percpu 'numa_mem', which is used primarily
4823 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4825 int local_memory_node(int node
)
4829 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4830 gfp_zone(GFP_KERNEL
),
4832 return z
->zone
->node
;
4836 #else /* CONFIG_NUMA */
4838 static void set_zonelist_order(void)
4840 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4843 static void build_zonelists(pg_data_t
*pgdat
)
4845 int node
, local_node
;
4847 struct zonelist
*zonelist
;
4849 local_node
= pgdat
->node_id
;
4851 zonelist
= &pgdat
->node_zonelists
[0];
4852 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4855 * Now we build the zonelist so that it contains the zones
4856 * of all the other nodes.
4857 * We don't want to pressure a particular node, so when
4858 * building the zones for node N, we make sure that the
4859 * zones coming right after the local ones are those from
4860 * node N+1 (modulo N)
4862 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4863 if (!node_online(node
))
4865 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4867 for (node
= 0; node
< local_node
; node
++) {
4868 if (!node_online(node
))
4870 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4873 zonelist
->_zonerefs
[j
].zone
= NULL
;
4874 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4877 #endif /* CONFIG_NUMA */
4880 * Boot pageset table. One per cpu which is going to be used for all
4881 * zones and all nodes. The parameters will be set in such a way
4882 * that an item put on a list will immediately be handed over to
4883 * the buddy list. This is safe since pageset manipulation is done
4884 * with interrupts disabled.
4886 * The boot_pagesets must be kept even after bootup is complete for
4887 * unused processors and/or zones. They do play a role for bootstrapping
4888 * hotplugged processors.
4890 * zoneinfo_show() and maybe other functions do
4891 * not check if the processor is online before following the pageset pointer.
4892 * Other parts of the kernel may not check if the zone is available.
4894 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4895 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4896 static void setup_zone_pageset(struct zone
*zone
);
4899 * Global mutex to protect against size modification of zonelists
4900 * as well as to serialize pageset setup for the new populated zone.
4902 DEFINE_MUTEX(zonelists_mutex
);
4904 /* return values int ....just for stop_machine() */
4905 static int __build_all_zonelists(void *data
)
4909 pg_data_t
*self
= data
;
4912 memset(node_load
, 0, sizeof(node_load
));
4915 if (self
&& !node_online(self
->node_id
)) {
4916 build_zonelists(self
);
4919 for_each_online_node(nid
) {
4920 pg_data_t
*pgdat
= NODE_DATA(nid
);
4922 build_zonelists(pgdat
);
4926 * Initialize the boot_pagesets that are going to be used
4927 * for bootstrapping processors. The real pagesets for
4928 * each zone will be allocated later when the per cpu
4929 * allocator is available.
4931 * boot_pagesets are used also for bootstrapping offline
4932 * cpus if the system is already booted because the pagesets
4933 * are needed to initialize allocators on a specific cpu too.
4934 * F.e. the percpu allocator needs the page allocator which
4935 * needs the percpu allocator in order to allocate its pagesets
4936 * (a chicken-egg dilemma).
4938 for_each_possible_cpu(cpu
) {
4939 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4941 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4943 * We now know the "local memory node" for each node--
4944 * i.e., the node of the first zone in the generic zonelist.
4945 * Set up numa_mem percpu variable for on-line cpus. During
4946 * boot, only the boot cpu should be on-line; we'll init the
4947 * secondary cpus' numa_mem as they come on-line. During
4948 * node/memory hotplug, we'll fixup all on-line cpus.
4950 if (cpu_online(cpu
))
4951 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4958 static noinline
void __init
4959 build_all_zonelists_init(void)
4961 __build_all_zonelists(NULL
);
4962 mminit_verify_zonelist();
4963 cpuset_init_current_mems_allowed();
4967 * Called with zonelists_mutex held always
4968 * unless system_state == SYSTEM_BOOTING.
4970 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4971 * [we're only called with non-NULL zone through __meminit paths] and
4972 * (2) call of __init annotated helper build_all_zonelists_init
4973 * [protected by SYSTEM_BOOTING].
4975 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4977 set_zonelist_order();
4979 if (system_state
== SYSTEM_BOOTING
) {
4980 build_all_zonelists_init();
4982 #ifdef CONFIG_MEMORY_HOTPLUG
4984 setup_zone_pageset(zone
);
4986 /* we have to stop all cpus to guarantee there is no user
4988 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4989 /* cpuset refresh routine should be here */
4991 vm_total_pages
= nr_free_pagecache_pages();
4993 * Disable grouping by mobility if the number of pages in the
4994 * system is too low to allow the mechanism to work. It would be
4995 * more accurate, but expensive to check per-zone. This check is
4996 * made on memory-hotadd so a system can start with mobility
4997 * disabled and enable it later
4999 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5000 page_group_by_mobility_disabled
= 1;
5002 page_group_by_mobility_disabled
= 0;
5004 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5006 zonelist_order_name
[current_zonelist_order
],
5007 page_group_by_mobility_disabled
? "off" : "on",
5010 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5015 * Helper functions to size the waitqueue hash table.
5016 * Essentially these want to choose hash table sizes sufficiently
5017 * large so that collisions trying to wait on pages are rare.
5018 * But in fact, the number of active page waitqueues on typical
5019 * systems is ridiculously low, less than 200. So this is even
5020 * conservative, even though it seems large.
5022 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
5023 * waitqueues, i.e. the size of the waitq table given the number of pages.
5025 #define PAGES_PER_WAITQUEUE 256
5027 #ifndef CONFIG_MEMORY_HOTPLUG
5028 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5030 unsigned long size
= 1;
5032 pages
/= PAGES_PER_WAITQUEUE
;
5034 while (size
< pages
)
5038 * Once we have dozens or even hundreds of threads sleeping
5039 * on IO we've got bigger problems than wait queue collision.
5040 * Limit the size of the wait table to a reasonable size.
5042 size
= min(size
, 4096UL);
5044 return max(size
, 4UL);
5048 * A zone's size might be changed by hot-add, so it is not possible to determine
5049 * a suitable size for its wait_table. So we use the maximum size now.
5051 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5053 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5054 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5055 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5057 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5058 * or more by the traditional way. (See above). It equals:
5060 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5061 * ia64(16K page size) : = ( 8G + 4M)byte.
5062 * powerpc (64K page size) : = (32G +16M)byte.
5064 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5071 * This is an integer logarithm so that shifts can be used later
5072 * to extract the more random high bits from the multiplicative
5073 * hash function before the remainder is taken.
5075 static inline unsigned long wait_table_bits(unsigned long size
)
5081 * Initially all pages are reserved - free ones are freed
5082 * up by free_all_bootmem() once the early boot process is
5083 * done. Non-atomic initialization, single-pass.
5085 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5086 unsigned long start_pfn
, enum memmap_context context
)
5088 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5089 unsigned long end_pfn
= start_pfn
+ size
;
5090 pg_data_t
*pgdat
= NODE_DATA(nid
);
5092 unsigned long nr_initialised
= 0;
5093 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5094 struct memblock_region
*r
= NULL
, *tmp
;
5097 if (highest_memmap_pfn
< end_pfn
- 1)
5098 highest_memmap_pfn
= end_pfn
- 1;
5101 * Honor reservation requested by the driver for this ZONE_DEVICE
5104 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5105 start_pfn
+= altmap
->reserve
;
5107 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5109 * There can be holes in boot-time mem_map[]s handed to this
5110 * function. They do not exist on hotplugged memory.
5112 if (context
!= MEMMAP_EARLY
)
5115 if (!early_pfn_valid(pfn
))
5117 if (!early_pfn_in_nid(pfn
, nid
))
5119 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5122 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5124 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5125 * from zone_movable_pfn[nid] to end of each node should be
5126 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5128 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
5129 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
5133 * Check given memblock attribute by firmware which can affect
5134 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5135 * mirrored, it's an overlapped memmap init. skip it.
5137 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5138 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5139 for_each_memblock(memory
, tmp
)
5140 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5144 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5145 memblock_is_mirror(r
)) {
5146 /* already initialized as NORMAL */
5147 pfn
= memblock_region_memory_end_pfn(r
);
5155 * Mark the block movable so that blocks are reserved for
5156 * movable at startup. This will force kernel allocations
5157 * to reserve their blocks rather than leaking throughout
5158 * the address space during boot when many long-lived
5159 * kernel allocations are made.
5161 * bitmap is created for zone's valid pfn range. but memmap
5162 * can be created for invalid pages (for alignment)
5163 * check here not to call set_pageblock_migratetype() against
5166 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5167 struct page
*page
= pfn_to_page(pfn
);
5169 __init_single_page(page
, pfn
, zone
, nid
);
5170 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5172 __init_single_pfn(pfn
, zone
, nid
);
5177 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5179 unsigned int order
, t
;
5180 for_each_migratetype_order(order
, t
) {
5181 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5182 zone
->free_area
[order
].nr_free
= 0;
5186 #ifndef __HAVE_ARCH_MEMMAP_INIT
5187 #define memmap_init(size, nid, zone, start_pfn) \
5188 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5191 static int zone_batchsize(struct zone
*zone
)
5197 * The per-cpu-pages pools are set to around 1000th of the
5198 * size of the zone. But no more than 1/2 of a meg.
5200 * OK, so we don't know how big the cache is. So guess.
5202 batch
= zone
->managed_pages
/ 1024;
5203 if (batch
* PAGE_SIZE
> 512 * 1024)
5204 batch
= (512 * 1024) / PAGE_SIZE
;
5205 batch
/= 4; /* We effectively *= 4 below */
5210 * Clamp the batch to a 2^n - 1 value. Having a power
5211 * of 2 value was found to be more likely to have
5212 * suboptimal cache aliasing properties in some cases.
5214 * For example if 2 tasks are alternately allocating
5215 * batches of pages, one task can end up with a lot
5216 * of pages of one half of the possible page colors
5217 * and the other with pages of the other colors.
5219 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5224 /* The deferral and batching of frees should be suppressed under NOMMU
5227 * The problem is that NOMMU needs to be able to allocate large chunks
5228 * of contiguous memory as there's no hardware page translation to
5229 * assemble apparent contiguous memory from discontiguous pages.
5231 * Queueing large contiguous runs of pages for batching, however,
5232 * causes the pages to actually be freed in smaller chunks. As there
5233 * can be a significant delay between the individual batches being
5234 * recycled, this leads to the once large chunks of space being
5235 * fragmented and becoming unavailable for high-order allocations.
5242 * pcp->high and pcp->batch values are related and dependent on one another:
5243 * ->batch must never be higher then ->high.
5244 * The following function updates them in a safe manner without read side
5247 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5248 * those fields changing asynchronously (acording the the above rule).
5250 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5251 * outside of boot time (or some other assurance that no concurrent updaters
5254 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5255 unsigned long batch
)
5257 /* start with a fail safe value for batch */
5261 /* Update high, then batch, in order */
5268 /* a companion to pageset_set_high() */
5269 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5271 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5274 static void pageset_init(struct per_cpu_pageset
*p
)
5276 struct per_cpu_pages
*pcp
;
5279 memset(p
, 0, sizeof(*p
));
5283 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5284 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5287 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5290 pageset_set_batch(p
, batch
);
5294 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5295 * to the value high for the pageset p.
5297 static void pageset_set_high(struct per_cpu_pageset
*p
,
5300 unsigned long batch
= max(1UL, high
/ 4);
5301 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5302 batch
= PAGE_SHIFT
* 8;
5304 pageset_update(&p
->pcp
, high
, batch
);
5307 static void pageset_set_high_and_batch(struct zone
*zone
,
5308 struct per_cpu_pageset
*pcp
)
5310 if (percpu_pagelist_fraction
)
5311 pageset_set_high(pcp
,
5312 (zone
->managed_pages
/
5313 percpu_pagelist_fraction
));
5315 pageset_set_batch(pcp
, zone_batchsize(zone
));
5318 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5320 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5323 pageset_set_high_and_batch(zone
, pcp
);
5326 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5329 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5330 for_each_possible_cpu(cpu
)
5331 zone_pageset_init(zone
, cpu
);
5333 if (!zone
->zone_pgdat
->per_cpu_nodestats
) {
5334 zone
->zone_pgdat
->per_cpu_nodestats
=
5335 alloc_percpu(struct per_cpu_nodestat
);
5340 * Allocate per cpu pagesets and initialize them.
5341 * Before this call only boot pagesets were available.
5343 void __init
setup_per_cpu_pageset(void)
5347 for_each_populated_zone(zone
)
5348 setup_zone_pageset(zone
);
5351 static noinline __init_refok
5352 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
5358 * The per-page waitqueue mechanism uses hashed waitqueues
5361 zone
->wait_table_hash_nr_entries
=
5362 wait_table_hash_nr_entries(zone_size_pages
);
5363 zone
->wait_table_bits
=
5364 wait_table_bits(zone
->wait_table_hash_nr_entries
);
5365 alloc_size
= zone
->wait_table_hash_nr_entries
5366 * sizeof(wait_queue_head_t
);
5368 if (!slab_is_available()) {
5369 zone
->wait_table
= (wait_queue_head_t
*)
5370 memblock_virt_alloc_node_nopanic(
5371 alloc_size
, zone
->zone_pgdat
->node_id
);
5374 * This case means that a zone whose size was 0 gets new memory
5375 * via memory hot-add.
5376 * But it may be the case that a new node was hot-added. In
5377 * this case vmalloc() will not be able to use this new node's
5378 * memory - this wait_table must be initialized to use this new
5379 * node itself as well.
5380 * To use this new node's memory, further consideration will be
5383 zone
->wait_table
= vmalloc(alloc_size
);
5385 if (!zone
->wait_table
)
5388 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
5389 init_waitqueue_head(zone
->wait_table
+ i
);
5394 static __meminit
void zone_pcp_init(struct zone
*zone
)
5397 * per cpu subsystem is not up at this point. The following code
5398 * relies on the ability of the linker to provide the
5399 * offset of a (static) per cpu variable into the per cpu area.
5401 zone
->pageset
= &boot_pageset
;
5403 if (populated_zone(zone
))
5404 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5405 zone
->name
, zone
->present_pages
,
5406 zone_batchsize(zone
));
5409 int __meminit
init_currently_empty_zone(struct zone
*zone
,
5410 unsigned long zone_start_pfn
,
5413 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5415 ret
= zone_wait_table_init(zone
, size
);
5418 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5420 zone
->zone_start_pfn
= zone_start_pfn
;
5422 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5423 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5425 (unsigned long)zone_idx(zone
),
5426 zone_start_pfn
, (zone_start_pfn
+ size
));
5428 zone_init_free_lists(zone
);
5433 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5434 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5437 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5439 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5440 struct mminit_pfnnid_cache
*state
)
5442 unsigned long start_pfn
, end_pfn
;
5445 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5446 return state
->last_nid
;
5448 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5450 state
->last_start
= start_pfn
;
5451 state
->last_end
= end_pfn
;
5452 state
->last_nid
= nid
;
5457 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5460 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5461 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5462 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5464 * If an architecture guarantees that all ranges registered contain no holes
5465 * and may be freed, this this function may be used instead of calling
5466 * memblock_free_early_nid() manually.
5468 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5470 unsigned long start_pfn
, end_pfn
;
5473 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5474 start_pfn
= min(start_pfn
, max_low_pfn
);
5475 end_pfn
= min(end_pfn
, max_low_pfn
);
5477 if (start_pfn
< end_pfn
)
5478 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5479 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5485 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5486 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5488 * If an architecture guarantees that all ranges registered contain no holes and may
5489 * be freed, this function may be used instead of calling memory_present() manually.
5491 void __init
sparse_memory_present_with_active_regions(int nid
)
5493 unsigned long start_pfn
, end_pfn
;
5496 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5497 memory_present(this_nid
, start_pfn
, end_pfn
);
5501 * get_pfn_range_for_nid - Return the start and end page frames for a node
5502 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5503 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5504 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5506 * It returns the start and end page frame of a node based on information
5507 * provided by memblock_set_node(). If called for a node
5508 * with no available memory, a warning is printed and the start and end
5511 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5512 unsigned long *start_pfn
, unsigned long *end_pfn
)
5514 unsigned long this_start_pfn
, this_end_pfn
;
5520 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5521 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5522 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5525 if (*start_pfn
== -1UL)
5530 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5531 * assumption is made that zones within a node are ordered in monotonic
5532 * increasing memory addresses so that the "highest" populated zone is used
5534 static void __init
find_usable_zone_for_movable(void)
5537 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5538 if (zone_index
== ZONE_MOVABLE
)
5541 if (arch_zone_highest_possible_pfn
[zone_index
] >
5542 arch_zone_lowest_possible_pfn
[zone_index
])
5546 VM_BUG_ON(zone_index
== -1);
5547 movable_zone
= zone_index
;
5551 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5552 * because it is sized independent of architecture. Unlike the other zones,
5553 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5554 * in each node depending on the size of each node and how evenly kernelcore
5555 * is distributed. This helper function adjusts the zone ranges
5556 * provided by the architecture for a given node by using the end of the
5557 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5558 * zones within a node are in order of monotonic increases memory addresses
5560 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5561 unsigned long zone_type
,
5562 unsigned long node_start_pfn
,
5563 unsigned long node_end_pfn
,
5564 unsigned long *zone_start_pfn
,
5565 unsigned long *zone_end_pfn
)
5567 /* Only adjust if ZONE_MOVABLE is on this node */
5568 if (zone_movable_pfn
[nid
]) {
5569 /* Size ZONE_MOVABLE */
5570 if (zone_type
== ZONE_MOVABLE
) {
5571 *zone_start_pfn
= zone_movable_pfn
[nid
];
5572 *zone_end_pfn
= min(node_end_pfn
,
5573 arch_zone_highest_possible_pfn
[movable_zone
]);
5575 /* Check if this whole range is within ZONE_MOVABLE */
5576 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5577 *zone_start_pfn
= *zone_end_pfn
;
5582 * Return the number of pages a zone spans in a node, including holes
5583 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5585 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5586 unsigned long zone_type
,
5587 unsigned long node_start_pfn
,
5588 unsigned long node_end_pfn
,
5589 unsigned long *zone_start_pfn
,
5590 unsigned long *zone_end_pfn
,
5591 unsigned long *ignored
)
5593 /* When hotadd a new node from cpu_up(), the node should be empty */
5594 if (!node_start_pfn
&& !node_end_pfn
)
5597 /* Get the start and end of the zone */
5598 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5599 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5600 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5601 node_start_pfn
, node_end_pfn
,
5602 zone_start_pfn
, zone_end_pfn
);
5604 /* Check that this node has pages within the zone's required range */
5605 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5608 /* Move the zone boundaries inside the node if necessary */
5609 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5610 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5612 /* Return the spanned pages */
5613 return *zone_end_pfn
- *zone_start_pfn
;
5617 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5618 * then all holes in the requested range will be accounted for.
5620 unsigned long __meminit
__absent_pages_in_range(int nid
,
5621 unsigned long range_start_pfn
,
5622 unsigned long range_end_pfn
)
5624 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5625 unsigned long start_pfn
, end_pfn
;
5628 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5629 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5630 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5631 nr_absent
-= end_pfn
- start_pfn
;
5637 * absent_pages_in_range - Return number of page frames in holes within a range
5638 * @start_pfn: The start PFN to start searching for holes
5639 * @end_pfn: The end PFN to stop searching for holes
5641 * It returns the number of pages frames in memory holes within a range.
5643 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5644 unsigned long end_pfn
)
5646 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5649 /* Return the number of page frames in holes in a zone on a node */
5650 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5651 unsigned long zone_type
,
5652 unsigned long node_start_pfn
,
5653 unsigned long node_end_pfn
,
5654 unsigned long *ignored
)
5656 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5657 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5658 unsigned long zone_start_pfn
, zone_end_pfn
;
5659 unsigned long nr_absent
;
5661 /* When hotadd a new node from cpu_up(), the node should be empty */
5662 if (!node_start_pfn
&& !node_end_pfn
)
5665 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5666 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5668 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5669 node_start_pfn
, node_end_pfn
,
5670 &zone_start_pfn
, &zone_end_pfn
);
5671 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5674 * ZONE_MOVABLE handling.
5675 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5678 if (zone_movable_pfn
[nid
]) {
5679 if (mirrored_kernelcore
) {
5680 unsigned long start_pfn
, end_pfn
;
5681 struct memblock_region
*r
;
5683 for_each_memblock(memory
, r
) {
5684 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5685 zone_start_pfn
, zone_end_pfn
);
5686 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5687 zone_start_pfn
, zone_end_pfn
);
5689 if (zone_type
== ZONE_MOVABLE
&&
5690 memblock_is_mirror(r
))
5691 nr_absent
+= end_pfn
- start_pfn
;
5693 if (zone_type
== ZONE_NORMAL
&&
5694 !memblock_is_mirror(r
))
5695 nr_absent
+= end_pfn
- start_pfn
;
5698 if (zone_type
== ZONE_NORMAL
)
5699 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5706 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5707 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5708 unsigned long zone_type
,
5709 unsigned long node_start_pfn
,
5710 unsigned long node_end_pfn
,
5711 unsigned long *zone_start_pfn
,
5712 unsigned long *zone_end_pfn
,
5713 unsigned long *zones_size
)
5717 *zone_start_pfn
= node_start_pfn
;
5718 for (zone
= 0; zone
< zone_type
; zone
++)
5719 *zone_start_pfn
+= zones_size
[zone
];
5721 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5723 return zones_size
[zone_type
];
5726 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5727 unsigned long zone_type
,
5728 unsigned long node_start_pfn
,
5729 unsigned long node_end_pfn
,
5730 unsigned long *zholes_size
)
5735 return zholes_size
[zone_type
];
5738 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5740 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5741 unsigned long node_start_pfn
,
5742 unsigned long node_end_pfn
,
5743 unsigned long *zones_size
,
5744 unsigned long *zholes_size
)
5746 unsigned long realtotalpages
= 0, totalpages
= 0;
5749 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5750 struct zone
*zone
= pgdat
->node_zones
+ i
;
5751 unsigned long zone_start_pfn
, zone_end_pfn
;
5752 unsigned long size
, real_size
;
5754 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5760 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5761 node_start_pfn
, node_end_pfn
,
5764 zone
->zone_start_pfn
= zone_start_pfn
;
5766 zone
->zone_start_pfn
= 0;
5767 zone
->spanned_pages
= size
;
5768 zone
->present_pages
= real_size
;
5771 realtotalpages
+= real_size
;
5774 pgdat
->node_spanned_pages
= totalpages
;
5775 pgdat
->node_present_pages
= realtotalpages
;
5776 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5780 #ifndef CONFIG_SPARSEMEM
5782 * Calculate the size of the zone->blockflags rounded to an unsigned long
5783 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5784 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5785 * round what is now in bits to nearest long in bits, then return it in
5788 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5790 unsigned long usemapsize
;
5792 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5793 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5794 usemapsize
= usemapsize
>> pageblock_order
;
5795 usemapsize
*= NR_PAGEBLOCK_BITS
;
5796 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5798 return usemapsize
/ 8;
5801 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5803 unsigned long zone_start_pfn
,
5804 unsigned long zonesize
)
5806 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5807 zone
->pageblock_flags
= NULL
;
5809 zone
->pageblock_flags
=
5810 memblock_virt_alloc_node_nopanic(usemapsize
,
5814 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5815 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5816 #endif /* CONFIG_SPARSEMEM */
5818 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5820 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5821 void __paginginit
set_pageblock_order(void)
5825 /* Check that pageblock_nr_pages has not already been setup */
5826 if (pageblock_order
)
5829 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5830 order
= HUGETLB_PAGE_ORDER
;
5832 order
= MAX_ORDER
- 1;
5835 * Assume the largest contiguous order of interest is a huge page.
5836 * This value may be variable depending on boot parameters on IA64 and
5839 pageblock_order
= order
;
5841 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5844 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5845 * is unused as pageblock_order is set at compile-time. See
5846 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5849 void __paginginit
set_pageblock_order(void)
5853 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5855 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5856 unsigned long present_pages
)
5858 unsigned long pages
= spanned_pages
;
5861 * Provide a more accurate estimation if there are holes within
5862 * the zone and SPARSEMEM is in use. If there are holes within the
5863 * zone, each populated memory region may cost us one or two extra
5864 * memmap pages due to alignment because memmap pages for each
5865 * populated regions may not naturally algined on page boundary.
5866 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5868 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5869 IS_ENABLED(CONFIG_SPARSEMEM
))
5870 pages
= present_pages
;
5872 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5876 * Set up the zone data structures:
5877 * - mark all pages reserved
5878 * - mark all memory queues empty
5879 * - clear the memory bitmaps
5881 * NOTE: pgdat should get zeroed by caller.
5883 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5886 int nid
= pgdat
->node_id
;
5889 pgdat_resize_init(pgdat
);
5890 #ifdef CONFIG_NUMA_BALANCING
5891 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5892 pgdat
->numabalancing_migrate_nr_pages
= 0;
5893 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5895 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5896 spin_lock_init(&pgdat
->split_queue_lock
);
5897 INIT_LIST_HEAD(&pgdat
->split_queue
);
5898 pgdat
->split_queue_len
= 0;
5900 init_waitqueue_head(&pgdat
->kswapd_wait
);
5901 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5902 #ifdef CONFIG_COMPACTION
5903 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5905 pgdat_page_ext_init(pgdat
);
5906 spin_lock_init(&pgdat
->lru_lock
);
5907 lruvec_init(node_lruvec(pgdat
));
5909 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5910 struct zone
*zone
= pgdat
->node_zones
+ j
;
5911 unsigned long size
, realsize
, freesize
, memmap_pages
;
5912 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5914 size
= zone
->spanned_pages
;
5915 realsize
= freesize
= zone
->present_pages
;
5918 * Adjust freesize so that it accounts for how much memory
5919 * is used by this zone for memmap. This affects the watermark
5920 * and per-cpu initialisations
5922 memmap_pages
= calc_memmap_size(size
, realsize
);
5923 if (!is_highmem_idx(j
)) {
5924 if (freesize
>= memmap_pages
) {
5925 freesize
-= memmap_pages
;
5928 " %s zone: %lu pages used for memmap\n",
5929 zone_names
[j
], memmap_pages
);
5931 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5932 zone_names
[j
], memmap_pages
, freesize
);
5935 /* Account for reserved pages */
5936 if (j
== 0 && freesize
> dma_reserve
) {
5937 freesize
-= dma_reserve
;
5938 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5939 zone_names
[0], dma_reserve
);
5942 if (!is_highmem_idx(j
))
5943 nr_kernel_pages
+= freesize
;
5944 /* Charge for highmem memmap if there are enough kernel pages */
5945 else if (nr_kernel_pages
> memmap_pages
* 2)
5946 nr_kernel_pages
-= memmap_pages
;
5947 nr_all_pages
+= freesize
;
5950 * Set an approximate value for lowmem here, it will be adjusted
5951 * when the bootmem allocator frees pages into the buddy system.
5952 * And all highmem pages will be managed by the buddy system.
5954 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5957 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5959 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5961 zone
->name
= zone_names
[j
];
5962 zone
->zone_pgdat
= pgdat
;
5963 spin_lock_init(&zone
->lock
);
5964 zone_seqlock_init(zone
);
5965 zone_pcp_init(zone
);
5967 /* For bootup, initialized properly in watermark setup */
5968 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5973 set_pageblock_order();
5974 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5975 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5977 memmap_init(size
, nid
, j
, zone_start_pfn
);
5981 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5983 unsigned long __maybe_unused start
= 0;
5984 unsigned long __maybe_unused offset
= 0;
5986 /* Skip empty nodes */
5987 if (!pgdat
->node_spanned_pages
)
5990 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5991 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5992 offset
= pgdat
->node_start_pfn
- start
;
5993 /* ia64 gets its own node_mem_map, before this, without bootmem */
5994 if (!pgdat
->node_mem_map
) {
5995 unsigned long size
, end
;
5999 * The zone's endpoints aren't required to be MAX_ORDER
6000 * aligned but the node_mem_map endpoints must be in order
6001 * for the buddy allocator to function correctly.
6003 end
= pgdat_end_pfn(pgdat
);
6004 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6005 size
= (end
- start
) * sizeof(struct page
);
6006 map
= alloc_remap(pgdat
->node_id
, size
);
6008 map
= memblock_virt_alloc_node_nopanic(size
,
6010 pgdat
->node_mem_map
= map
+ offset
;
6012 #ifndef CONFIG_NEED_MULTIPLE_NODES
6014 * With no DISCONTIG, the global mem_map is just set as node 0's
6016 if (pgdat
== NODE_DATA(0)) {
6017 mem_map
= NODE_DATA(0)->node_mem_map
;
6018 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6019 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6021 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6024 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6027 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6028 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6030 pg_data_t
*pgdat
= NODE_DATA(nid
);
6031 unsigned long start_pfn
= 0;
6032 unsigned long end_pfn
= 0;
6034 /* pg_data_t should be reset to zero when it's allocated */
6035 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6037 reset_deferred_meminit(pgdat
);
6038 pgdat
->node_id
= nid
;
6039 pgdat
->node_start_pfn
= node_start_pfn
;
6040 pgdat
->per_cpu_nodestats
= NULL
;
6041 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6042 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6043 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6044 (u64
)start_pfn
<< PAGE_SHIFT
,
6045 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6047 start_pfn
= node_start_pfn
;
6049 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6050 zones_size
, zholes_size
);
6052 alloc_node_mem_map(pgdat
);
6053 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6054 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6055 nid
, (unsigned long)pgdat
,
6056 (unsigned long)pgdat
->node_mem_map
);
6059 free_area_init_core(pgdat
);
6062 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6064 #if MAX_NUMNODES > 1
6066 * Figure out the number of possible node ids.
6068 void __init
setup_nr_node_ids(void)
6070 unsigned int highest
;
6072 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6073 nr_node_ids
= highest
+ 1;
6078 * node_map_pfn_alignment - determine the maximum internode alignment
6080 * This function should be called after node map is populated and sorted.
6081 * It calculates the maximum power of two alignment which can distinguish
6084 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6085 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6086 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6087 * shifted, 1GiB is enough and this function will indicate so.
6089 * This is used to test whether pfn -> nid mapping of the chosen memory
6090 * model has fine enough granularity to avoid incorrect mapping for the
6091 * populated node map.
6093 * Returns the determined alignment in pfn's. 0 if there is no alignment
6094 * requirement (single node).
6096 unsigned long __init
node_map_pfn_alignment(void)
6098 unsigned long accl_mask
= 0, last_end
= 0;
6099 unsigned long start
, end
, mask
;
6103 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6104 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6111 * Start with a mask granular enough to pin-point to the
6112 * start pfn and tick off bits one-by-one until it becomes
6113 * too coarse to separate the current node from the last.
6115 mask
= ~((1 << __ffs(start
)) - 1);
6116 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6119 /* accumulate all internode masks */
6123 /* convert mask to number of pages */
6124 return ~accl_mask
+ 1;
6127 /* Find the lowest pfn for a node */
6128 static unsigned long __init
find_min_pfn_for_node(int nid
)
6130 unsigned long min_pfn
= ULONG_MAX
;
6131 unsigned long start_pfn
;
6134 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6135 min_pfn
= min(min_pfn
, start_pfn
);
6137 if (min_pfn
== ULONG_MAX
) {
6138 pr_warn("Could not find start_pfn for node %d\n", nid
);
6146 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6148 * It returns the minimum PFN based on information provided via
6149 * memblock_set_node().
6151 unsigned long __init
find_min_pfn_with_active_regions(void)
6153 return find_min_pfn_for_node(MAX_NUMNODES
);
6157 * early_calculate_totalpages()
6158 * Sum pages in active regions for movable zone.
6159 * Populate N_MEMORY for calculating usable_nodes.
6161 static unsigned long __init
early_calculate_totalpages(void)
6163 unsigned long totalpages
= 0;
6164 unsigned long start_pfn
, end_pfn
;
6167 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6168 unsigned long pages
= end_pfn
- start_pfn
;
6170 totalpages
+= pages
;
6172 node_set_state(nid
, N_MEMORY
);
6178 * Find the PFN the Movable zone begins in each node. Kernel memory
6179 * is spread evenly between nodes as long as the nodes have enough
6180 * memory. When they don't, some nodes will have more kernelcore than
6183 static void __init
find_zone_movable_pfns_for_nodes(void)
6186 unsigned long usable_startpfn
;
6187 unsigned long kernelcore_node
, kernelcore_remaining
;
6188 /* save the state before borrow the nodemask */
6189 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6190 unsigned long totalpages
= early_calculate_totalpages();
6191 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6192 struct memblock_region
*r
;
6194 /* Need to find movable_zone earlier when movable_node is specified. */
6195 find_usable_zone_for_movable();
6198 * If movable_node is specified, ignore kernelcore and movablecore
6201 if (movable_node_is_enabled()) {
6202 for_each_memblock(memory
, r
) {
6203 if (!memblock_is_hotpluggable(r
))
6208 usable_startpfn
= PFN_DOWN(r
->base
);
6209 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6210 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6218 * If kernelcore=mirror is specified, ignore movablecore option
6220 if (mirrored_kernelcore
) {
6221 bool mem_below_4gb_not_mirrored
= false;
6223 for_each_memblock(memory
, r
) {
6224 if (memblock_is_mirror(r
))
6229 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6231 if (usable_startpfn
< 0x100000) {
6232 mem_below_4gb_not_mirrored
= true;
6236 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6237 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6241 if (mem_below_4gb_not_mirrored
)
6242 pr_warn("This configuration results in unmirrored kernel memory.");
6248 * If movablecore=nn[KMG] was specified, calculate what size of
6249 * kernelcore that corresponds so that memory usable for
6250 * any allocation type is evenly spread. If both kernelcore
6251 * and movablecore are specified, then the value of kernelcore
6252 * will be used for required_kernelcore if it's greater than
6253 * what movablecore would have allowed.
6255 if (required_movablecore
) {
6256 unsigned long corepages
;
6259 * Round-up so that ZONE_MOVABLE is at least as large as what
6260 * was requested by the user
6262 required_movablecore
=
6263 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6264 required_movablecore
= min(totalpages
, required_movablecore
);
6265 corepages
= totalpages
- required_movablecore
;
6267 required_kernelcore
= max(required_kernelcore
, corepages
);
6271 * If kernelcore was not specified or kernelcore size is larger
6272 * than totalpages, there is no ZONE_MOVABLE.
6274 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6277 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6278 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6281 /* Spread kernelcore memory as evenly as possible throughout nodes */
6282 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6283 for_each_node_state(nid
, N_MEMORY
) {
6284 unsigned long start_pfn
, end_pfn
;
6287 * Recalculate kernelcore_node if the division per node
6288 * now exceeds what is necessary to satisfy the requested
6289 * amount of memory for the kernel
6291 if (required_kernelcore
< kernelcore_node
)
6292 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6295 * As the map is walked, we track how much memory is usable
6296 * by the kernel using kernelcore_remaining. When it is
6297 * 0, the rest of the node is usable by ZONE_MOVABLE
6299 kernelcore_remaining
= kernelcore_node
;
6301 /* Go through each range of PFNs within this node */
6302 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6303 unsigned long size_pages
;
6305 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6306 if (start_pfn
>= end_pfn
)
6309 /* Account for what is only usable for kernelcore */
6310 if (start_pfn
< usable_startpfn
) {
6311 unsigned long kernel_pages
;
6312 kernel_pages
= min(end_pfn
, usable_startpfn
)
6315 kernelcore_remaining
-= min(kernel_pages
,
6316 kernelcore_remaining
);
6317 required_kernelcore
-= min(kernel_pages
,
6318 required_kernelcore
);
6320 /* Continue if range is now fully accounted */
6321 if (end_pfn
<= usable_startpfn
) {
6324 * Push zone_movable_pfn to the end so
6325 * that if we have to rebalance
6326 * kernelcore across nodes, we will
6327 * not double account here
6329 zone_movable_pfn
[nid
] = end_pfn
;
6332 start_pfn
= usable_startpfn
;
6336 * The usable PFN range for ZONE_MOVABLE is from
6337 * start_pfn->end_pfn. Calculate size_pages as the
6338 * number of pages used as kernelcore
6340 size_pages
= end_pfn
- start_pfn
;
6341 if (size_pages
> kernelcore_remaining
)
6342 size_pages
= kernelcore_remaining
;
6343 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6346 * Some kernelcore has been met, update counts and
6347 * break if the kernelcore for this node has been
6350 required_kernelcore
-= min(required_kernelcore
,
6352 kernelcore_remaining
-= size_pages
;
6353 if (!kernelcore_remaining
)
6359 * If there is still required_kernelcore, we do another pass with one
6360 * less node in the count. This will push zone_movable_pfn[nid] further
6361 * along on the nodes that still have memory until kernelcore is
6365 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6369 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6370 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6371 zone_movable_pfn
[nid
] =
6372 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6375 /* restore the node_state */
6376 node_states
[N_MEMORY
] = saved_node_state
;
6379 /* Any regular or high memory on that node ? */
6380 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6382 enum zone_type zone_type
;
6384 if (N_MEMORY
== N_NORMAL_MEMORY
)
6387 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6388 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6389 if (populated_zone(zone
)) {
6390 node_set_state(nid
, N_HIGH_MEMORY
);
6391 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6392 zone_type
<= ZONE_NORMAL
)
6393 node_set_state(nid
, N_NORMAL_MEMORY
);
6400 * free_area_init_nodes - Initialise all pg_data_t and zone data
6401 * @max_zone_pfn: an array of max PFNs for each zone
6403 * This will call free_area_init_node() for each active node in the system.
6404 * Using the page ranges provided by memblock_set_node(), the size of each
6405 * zone in each node and their holes is calculated. If the maximum PFN
6406 * between two adjacent zones match, it is assumed that the zone is empty.
6407 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6408 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6409 * starts where the previous one ended. For example, ZONE_DMA32 starts
6410 * at arch_max_dma_pfn.
6412 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6414 unsigned long start_pfn
, end_pfn
;
6417 /* Record where the zone boundaries are */
6418 memset(arch_zone_lowest_possible_pfn
, 0,
6419 sizeof(arch_zone_lowest_possible_pfn
));
6420 memset(arch_zone_highest_possible_pfn
, 0,
6421 sizeof(arch_zone_highest_possible_pfn
));
6423 start_pfn
= find_min_pfn_with_active_regions();
6425 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6426 if (i
== ZONE_MOVABLE
)
6429 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6430 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6431 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6433 start_pfn
= end_pfn
;
6435 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
6436 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
6438 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6439 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6440 find_zone_movable_pfns_for_nodes();
6442 /* Print out the zone ranges */
6443 pr_info("Zone ranges:\n");
6444 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6445 if (i
== ZONE_MOVABLE
)
6447 pr_info(" %-8s ", zone_names
[i
]);
6448 if (arch_zone_lowest_possible_pfn
[i
] ==
6449 arch_zone_highest_possible_pfn
[i
])
6452 pr_cont("[mem %#018Lx-%#018Lx]\n",
6453 (u64
)arch_zone_lowest_possible_pfn
[i
]
6455 ((u64
)arch_zone_highest_possible_pfn
[i
]
6456 << PAGE_SHIFT
) - 1);
6459 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6460 pr_info("Movable zone start for each node\n");
6461 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6462 if (zone_movable_pfn
[i
])
6463 pr_info(" Node %d: %#018Lx\n", i
,
6464 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6467 /* Print out the early node map */
6468 pr_info("Early memory node ranges\n");
6469 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6470 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6471 (u64
)start_pfn
<< PAGE_SHIFT
,
6472 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6474 /* Initialise every node */
6475 mminit_verify_pageflags_layout();
6476 setup_nr_node_ids();
6477 for_each_online_node(nid
) {
6478 pg_data_t
*pgdat
= NODE_DATA(nid
);
6479 free_area_init_node(nid
, NULL
,
6480 find_min_pfn_for_node(nid
), NULL
);
6482 /* Any memory on that node */
6483 if (pgdat
->node_present_pages
)
6484 node_set_state(nid
, N_MEMORY
);
6485 check_for_memory(pgdat
, nid
);
6489 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6491 unsigned long long coremem
;
6495 coremem
= memparse(p
, &p
);
6496 *core
= coremem
>> PAGE_SHIFT
;
6498 /* Paranoid check that UL is enough for the coremem value */
6499 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6505 * kernelcore=size sets the amount of memory for use for allocations that
6506 * cannot be reclaimed or migrated.
6508 static int __init
cmdline_parse_kernelcore(char *p
)
6510 /* parse kernelcore=mirror */
6511 if (parse_option_str(p
, "mirror")) {
6512 mirrored_kernelcore
= true;
6516 return cmdline_parse_core(p
, &required_kernelcore
);
6520 * movablecore=size sets the amount of memory for use for allocations that
6521 * can be reclaimed or migrated.
6523 static int __init
cmdline_parse_movablecore(char *p
)
6525 return cmdline_parse_core(p
, &required_movablecore
);
6528 early_param("kernelcore", cmdline_parse_kernelcore
);
6529 early_param("movablecore", cmdline_parse_movablecore
);
6531 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6533 void adjust_managed_page_count(struct page
*page
, long count
)
6535 spin_lock(&managed_page_count_lock
);
6536 page_zone(page
)->managed_pages
+= count
;
6537 totalram_pages
+= count
;
6538 #ifdef CONFIG_HIGHMEM
6539 if (PageHighMem(page
))
6540 totalhigh_pages
+= count
;
6542 spin_unlock(&managed_page_count_lock
);
6544 EXPORT_SYMBOL(adjust_managed_page_count
);
6546 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6549 unsigned long pages
= 0;
6551 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6552 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6553 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6554 if ((unsigned int)poison
<= 0xFF)
6555 memset(pos
, poison
, PAGE_SIZE
);
6556 free_reserved_page(virt_to_page(pos
));
6560 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6561 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6565 EXPORT_SYMBOL(free_reserved_area
);
6567 #ifdef CONFIG_HIGHMEM
6568 void free_highmem_page(struct page
*page
)
6570 __free_reserved_page(page
);
6572 page_zone(page
)->managed_pages
++;
6578 void __init
mem_init_print_info(const char *str
)
6580 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6581 unsigned long init_code_size
, init_data_size
;
6583 physpages
= get_num_physpages();
6584 codesize
= _etext
- _stext
;
6585 datasize
= _edata
- _sdata
;
6586 rosize
= __end_rodata
- __start_rodata
;
6587 bss_size
= __bss_stop
- __bss_start
;
6588 init_data_size
= __init_end
- __init_begin
;
6589 init_code_size
= _einittext
- _sinittext
;
6592 * Detect special cases and adjust section sizes accordingly:
6593 * 1) .init.* may be embedded into .data sections
6594 * 2) .init.text.* may be out of [__init_begin, __init_end],
6595 * please refer to arch/tile/kernel/vmlinux.lds.S.
6596 * 3) .rodata.* may be embedded into .text or .data sections.
6598 #define adj_init_size(start, end, size, pos, adj) \
6600 if (start <= pos && pos < end && size > adj) \
6604 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6605 _sinittext
, init_code_size
);
6606 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6607 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6608 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6609 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6611 #undef adj_init_size
6613 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6614 #ifdef CONFIG_HIGHMEM
6618 nr_free_pages() << (PAGE_SHIFT
- 10),
6619 physpages
<< (PAGE_SHIFT
- 10),
6620 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6621 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6622 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6623 totalcma_pages
<< (PAGE_SHIFT
- 10),
6624 #ifdef CONFIG_HIGHMEM
6625 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6627 str
? ", " : "", str
? str
: "");
6631 * set_dma_reserve - set the specified number of pages reserved in the first zone
6632 * @new_dma_reserve: The number of pages to mark reserved
6634 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6635 * In the DMA zone, a significant percentage may be consumed by kernel image
6636 * and other unfreeable allocations which can skew the watermarks badly. This
6637 * function may optionally be used to account for unfreeable pages in the
6638 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6639 * smaller per-cpu batchsize.
6641 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6643 dma_reserve
= new_dma_reserve
;
6646 void __init
free_area_init(unsigned long *zones_size
)
6648 free_area_init_node(0, zones_size
,
6649 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6652 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6653 unsigned long action
, void *hcpu
)
6655 int cpu
= (unsigned long)hcpu
;
6657 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6658 lru_add_drain_cpu(cpu
);
6662 * Spill the event counters of the dead processor
6663 * into the current processors event counters.
6664 * This artificially elevates the count of the current
6667 vm_events_fold_cpu(cpu
);
6670 * Zero the differential counters of the dead processor
6671 * so that the vm statistics are consistent.
6673 * This is only okay since the processor is dead and cannot
6674 * race with what we are doing.
6676 cpu_vm_stats_fold(cpu
);
6681 void __init
page_alloc_init(void)
6683 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6687 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6688 * or min_free_kbytes changes.
6690 static void calculate_totalreserve_pages(void)
6692 struct pglist_data
*pgdat
;
6693 unsigned long reserve_pages
= 0;
6694 enum zone_type i
, j
;
6696 for_each_online_pgdat(pgdat
) {
6698 pgdat
->totalreserve_pages
= 0;
6700 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6701 struct zone
*zone
= pgdat
->node_zones
+ i
;
6704 /* Find valid and maximum lowmem_reserve in the zone */
6705 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6706 if (zone
->lowmem_reserve
[j
] > max
)
6707 max
= zone
->lowmem_reserve
[j
];
6710 /* we treat the high watermark as reserved pages. */
6711 max
+= high_wmark_pages(zone
);
6713 if (max
> zone
->managed_pages
)
6714 max
= zone
->managed_pages
;
6716 pgdat
->totalreserve_pages
+= max
;
6718 reserve_pages
+= max
;
6721 totalreserve_pages
= reserve_pages
;
6725 * setup_per_zone_lowmem_reserve - called whenever
6726 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6727 * has a correct pages reserved value, so an adequate number of
6728 * pages are left in the zone after a successful __alloc_pages().
6730 static void setup_per_zone_lowmem_reserve(void)
6732 struct pglist_data
*pgdat
;
6733 enum zone_type j
, idx
;
6735 for_each_online_pgdat(pgdat
) {
6736 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6737 struct zone
*zone
= pgdat
->node_zones
+ j
;
6738 unsigned long managed_pages
= zone
->managed_pages
;
6740 zone
->lowmem_reserve
[j
] = 0;
6744 struct zone
*lower_zone
;
6748 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6749 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6751 lower_zone
= pgdat
->node_zones
+ idx
;
6752 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6753 sysctl_lowmem_reserve_ratio
[idx
];
6754 managed_pages
+= lower_zone
->managed_pages
;
6759 /* update totalreserve_pages */
6760 calculate_totalreserve_pages();
6763 static void __setup_per_zone_wmarks(void)
6765 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6766 unsigned long lowmem_pages
= 0;
6768 unsigned long flags
;
6770 /* Calculate total number of !ZONE_HIGHMEM pages */
6771 for_each_zone(zone
) {
6772 if (!is_highmem(zone
))
6773 lowmem_pages
+= zone
->managed_pages
;
6776 for_each_zone(zone
) {
6779 spin_lock_irqsave(&zone
->lock
, flags
);
6780 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6781 do_div(tmp
, lowmem_pages
);
6782 if (is_highmem(zone
)) {
6784 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6785 * need highmem pages, so cap pages_min to a small
6788 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6789 * deltas control asynch page reclaim, and so should
6790 * not be capped for highmem.
6792 unsigned long min_pages
;
6794 min_pages
= zone
->managed_pages
/ 1024;
6795 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6796 zone
->watermark
[WMARK_MIN
] = min_pages
;
6799 * If it's a lowmem zone, reserve a number of pages
6800 * proportionate to the zone's size.
6802 zone
->watermark
[WMARK_MIN
] = tmp
;
6806 * Set the kswapd watermarks distance according to the
6807 * scale factor in proportion to available memory, but
6808 * ensure a minimum size on small systems.
6810 tmp
= max_t(u64
, tmp
>> 2,
6811 mult_frac(zone
->managed_pages
,
6812 watermark_scale_factor
, 10000));
6814 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6815 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6817 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6818 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6819 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6821 spin_unlock_irqrestore(&zone
->lock
, flags
);
6824 /* update totalreserve_pages */
6825 calculate_totalreserve_pages();
6829 * setup_per_zone_wmarks - called when min_free_kbytes changes
6830 * or when memory is hot-{added|removed}
6832 * Ensures that the watermark[min,low,high] values for each zone are set
6833 * correctly with respect to min_free_kbytes.
6835 void setup_per_zone_wmarks(void)
6837 mutex_lock(&zonelists_mutex
);
6838 __setup_per_zone_wmarks();
6839 mutex_unlock(&zonelists_mutex
);
6843 * Initialise min_free_kbytes.
6845 * For small machines we want it small (128k min). For large machines
6846 * we want it large (64MB max). But it is not linear, because network
6847 * bandwidth does not increase linearly with machine size. We use
6849 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6850 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6866 int __meminit
init_per_zone_wmark_min(void)
6868 unsigned long lowmem_kbytes
;
6869 int new_min_free_kbytes
;
6871 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6872 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6874 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6875 min_free_kbytes
= new_min_free_kbytes
;
6876 if (min_free_kbytes
< 128)
6877 min_free_kbytes
= 128;
6878 if (min_free_kbytes
> 65536)
6879 min_free_kbytes
= 65536;
6881 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6882 new_min_free_kbytes
, user_min_free_kbytes
);
6884 setup_per_zone_wmarks();
6885 refresh_zone_stat_thresholds();
6886 setup_per_zone_lowmem_reserve();
6889 core_initcall(init_per_zone_wmark_min
)
6892 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6893 * that we can call two helper functions whenever min_free_kbytes
6896 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6897 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6901 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6906 user_min_free_kbytes
= min_free_kbytes
;
6907 setup_per_zone_wmarks();
6912 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6913 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6917 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6922 setup_per_zone_wmarks();
6928 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6929 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6934 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6939 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6940 sysctl_min_unmapped_ratio
) / 100;
6944 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6945 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6950 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6955 zone
->min_slab_pages
= (zone
->managed_pages
*
6956 sysctl_min_slab_ratio
) / 100;
6962 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6963 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6964 * whenever sysctl_lowmem_reserve_ratio changes.
6966 * The reserve ratio obviously has absolutely no relation with the
6967 * minimum watermarks. The lowmem reserve ratio can only make sense
6968 * if in function of the boot time zone sizes.
6970 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6971 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6973 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6974 setup_per_zone_lowmem_reserve();
6979 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6980 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6981 * pagelist can have before it gets flushed back to buddy allocator.
6983 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6984 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6987 int old_percpu_pagelist_fraction
;
6990 mutex_lock(&pcp_batch_high_lock
);
6991 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6993 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6994 if (!write
|| ret
< 0)
6997 /* Sanity checking to avoid pcp imbalance */
6998 if (percpu_pagelist_fraction
&&
6999 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7000 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7006 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7009 for_each_populated_zone(zone
) {
7012 for_each_possible_cpu(cpu
)
7013 pageset_set_high_and_batch(zone
,
7014 per_cpu_ptr(zone
->pageset
, cpu
));
7017 mutex_unlock(&pcp_batch_high_lock
);
7022 int hashdist
= HASHDIST_DEFAULT
;
7024 static int __init
set_hashdist(char *str
)
7028 hashdist
= simple_strtoul(str
, &str
, 0);
7031 __setup("hashdist=", set_hashdist
);
7035 * allocate a large system hash table from bootmem
7036 * - it is assumed that the hash table must contain an exact power-of-2
7037 * quantity of entries
7038 * - limit is the number of hash buckets, not the total allocation size
7040 void *__init
alloc_large_system_hash(const char *tablename
,
7041 unsigned long bucketsize
,
7042 unsigned long numentries
,
7045 unsigned int *_hash_shift
,
7046 unsigned int *_hash_mask
,
7047 unsigned long low_limit
,
7048 unsigned long high_limit
)
7050 unsigned long long max
= high_limit
;
7051 unsigned long log2qty
, size
;
7054 /* allow the kernel cmdline to have a say */
7056 /* round applicable memory size up to nearest megabyte */
7057 numentries
= nr_kernel_pages
;
7059 /* It isn't necessary when PAGE_SIZE >= 1MB */
7060 if (PAGE_SHIFT
< 20)
7061 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7063 /* limit to 1 bucket per 2^scale bytes of low memory */
7064 if (scale
> PAGE_SHIFT
)
7065 numentries
>>= (scale
- PAGE_SHIFT
);
7067 numentries
<<= (PAGE_SHIFT
- scale
);
7069 /* Make sure we've got at least a 0-order allocation.. */
7070 if (unlikely(flags
& HASH_SMALL
)) {
7071 /* Makes no sense without HASH_EARLY */
7072 WARN_ON(!(flags
& HASH_EARLY
));
7073 if (!(numentries
>> *_hash_shift
)) {
7074 numentries
= 1UL << *_hash_shift
;
7075 BUG_ON(!numentries
);
7077 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7078 numentries
= PAGE_SIZE
/ bucketsize
;
7080 numentries
= roundup_pow_of_two(numentries
);
7082 /* limit allocation size to 1/16 total memory by default */
7084 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7085 do_div(max
, bucketsize
);
7087 max
= min(max
, 0x80000000ULL
);
7089 if (numentries
< low_limit
)
7090 numentries
= low_limit
;
7091 if (numentries
> max
)
7094 log2qty
= ilog2(numentries
);
7097 size
= bucketsize
<< log2qty
;
7098 if (flags
& HASH_EARLY
)
7099 table
= memblock_virt_alloc_nopanic(size
, 0);
7101 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
7104 * If bucketsize is not a power-of-two, we may free
7105 * some pages at the end of hash table which
7106 * alloc_pages_exact() automatically does
7108 if (get_order(size
) < MAX_ORDER
) {
7109 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
7110 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
7113 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7116 panic("Failed to allocate %s hash table\n", tablename
);
7118 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7119 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7122 *_hash_shift
= log2qty
;
7124 *_hash_mask
= (1 << log2qty
) - 1;
7130 * This function checks whether pageblock includes unmovable pages or not.
7131 * If @count is not zero, it is okay to include less @count unmovable pages
7133 * PageLRU check without isolation or lru_lock could race so that
7134 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7135 * expect this function should be exact.
7137 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7138 bool skip_hwpoisoned_pages
)
7140 unsigned long pfn
, iter
, found
;
7144 * For avoiding noise data, lru_add_drain_all() should be called
7145 * If ZONE_MOVABLE, the zone never contains unmovable pages
7147 if (zone_idx(zone
) == ZONE_MOVABLE
)
7149 mt
= get_pageblock_migratetype(page
);
7150 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7153 pfn
= page_to_pfn(page
);
7154 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7155 unsigned long check
= pfn
+ iter
;
7157 if (!pfn_valid_within(check
))
7160 page
= pfn_to_page(check
);
7163 * Hugepages are not in LRU lists, but they're movable.
7164 * We need not scan over tail pages bacause we don't
7165 * handle each tail page individually in migration.
7167 if (PageHuge(page
)) {
7168 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7173 * We can't use page_count without pin a page
7174 * because another CPU can free compound page.
7175 * This check already skips compound tails of THP
7176 * because their page->_refcount is zero at all time.
7178 if (!page_ref_count(page
)) {
7179 if (PageBuddy(page
))
7180 iter
+= (1 << page_order(page
)) - 1;
7185 * The HWPoisoned page may be not in buddy system, and
7186 * page_count() is not 0.
7188 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7194 * If there are RECLAIMABLE pages, we need to check
7195 * it. But now, memory offline itself doesn't call
7196 * shrink_node_slabs() and it still to be fixed.
7199 * If the page is not RAM, page_count()should be 0.
7200 * we don't need more check. This is an _used_ not-movable page.
7202 * The problematic thing here is PG_reserved pages. PG_reserved
7203 * is set to both of a memory hole page and a _used_ kernel
7212 bool is_pageblock_removable_nolock(struct page
*page
)
7218 * We have to be careful here because we are iterating over memory
7219 * sections which are not zone aware so we might end up outside of
7220 * the zone but still within the section.
7221 * We have to take care about the node as well. If the node is offline
7222 * its NODE_DATA will be NULL - see page_zone.
7224 if (!node_online(page_to_nid(page
)))
7227 zone
= page_zone(page
);
7228 pfn
= page_to_pfn(page
);
7229 if (!zone_spans_pfn(zone
, pfn
))
7232 return !has_unmovable_pages(zone
, page
, 0, true);
7235 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7237 static unsigned long pfn_max_align_down(unsigned long pfn
)
7239 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7240 pageblock_nr_pages
) - 1);
7243 static unsigned long pfn_max_align_up(unsigned long pfn
)
7245 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7246 pageblock_nr_pages
));
7249 /* [start, end) must belong to a single zone. */
7250 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7251 unsigned long start
, unsigned long end
)
7253 /* This function is based on compact_zone() from compaction.c. */
7254 unsigned long nr_reclaimed
;
7255 unsigned long pfn
= start
;
7256 unsigned int tries
= 0;
7261 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7262 if (fatal_signal_pending(current
)) {
7267 if (list_empty(&cc
->migratepages
)) {
7268 cc
->nr_migratepages
= 0;
7269 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7275 } else if (++tries
== 5) {
7276 ret
= ret
< 0 ? ret
: -EBUSY
;
7280 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7282 cc
->nr_migratepages
-= nr_reclaimed
;
7284 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7285 NULL
, 0, cc
->mode
, MR_CMA
);
7288 putback_movable_pages(&cc
->migratepages
);
7295 * alloc_contig_range() -- tries to allocate given range of pages
7296 * @start: start PFN to allocate
7297 * @end: one-past-the-last PFN to allocate
7298 * @migratetype: migratetype of the underlaying pageblocks (either
7299 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7300 * in range must have the same migratetype and it must
7301 * be either of the two.
7303 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7304 * aligned, however it's the caller's responsibility to guarantee that
7305 * we are the only thread that changes migrate type of pageblocks the
7308 * The PFN range must belong to a single zone.
7310 * Returns zero on success or negative error code. On success all
7311 * pages which PFN is in [start, end) are allocated for the caller and
7312 * need to be freed with free_contig_range().
7314 int alloc_contig_range(unsigned long start
, unsigned long end
,
7315 unsigned migratetype
)
7317 unsigned long outer_start
, outer_end
;
7321 struct compact_control cc
= {
7322 .nr_migratepages
= 0,
7324 .zone
= page_zone(pfn_to_page(start
)),
7325 .mode
= MIGRATE_SYNC
,
7326 .ignore_skip_hint
= true,
7328 INIT_LIST_HEAD(&cc
.migratepages
);
7331 * What we do here is we mark all pageblocks in range as
7332 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7333 * have different sizes, and due to the way page allocator
7334 * work, we align the range to biggest of the two pages so
7335 * that page allocator won't try to merge buddies from
7336 * different pageblocks and change MIGRATE_ISOLATE to some
7337 * other migration type.
7339 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7340 * migrate the pages from an unaligned range (ie. pages that
7341 * we are interested in). This will put all the pages in
7342 * range back to page allocator as MIGRATE_ISOLATE.
7344 * When this is done, we take the pages in range from page
7345 * allocator removing them from the buddy system. This way
7346 * page allocator will never consider using them.
7348 * This lets us mark the pageblocks back as
7349 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7350 * aligned range but not in the unaligned, original range are
7351 * put back to page allocator so that buddy can use them.
7354 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7355 pfn_max_align_up(end
), migratetype
,
7361 * In case of -EBUSY, we'd like to know which page causes problem.
7362 * So, just fall through. We will check it in test_pages_isolated().
7364 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7365 if (ret
&& ret
!= -EBUSY
)
7369 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7370 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7371 * more, all pages in [start, end) are free in page allocator.
7372 * What we are going to do is to allocate all pages from
7373 * [start, end) (that is remove them from page allocator).
7375 * The only problem is that pages at the beginning and at the
7376 * end of interesting range may be not aligned with pages that
7377 * page allocator holds, ie. they can be part of higher order
7378 * pages. Because of this, we reserve the bigger range and
7379 * once this is done free the pages we are not interested in.
7381 * We don't have to hold zone->lock here because the pages are
7382 * isolated thus they won't get removed from buddy.
7385 lru_add_drain_all();
7386 drain_all_pages(cc
.zone
);
7389 outer_start
= start
;
7390 while (!PageBuddy(pfn_to_page(outer_start
))) {
7391 if (++order
>= MAX_ORDER
) {
7392 outer_start
= start
;
7395 outer_start
&= ~0UL << order
;
7398 if (outer_start
!= start
) {
7399 order
= page_order(pfn_to_page(outer_start
));
7402 * outer_start page could be small order buddy page and
7403 * it doesn't include start page. Adjust outer_start
7404 * in this case to report failed page properly
7405 * on tracepoint in test_pages_isolated()
7407 if (outer_start
+ (1UL << order
) <= start
)
7408 outer_start
= start
;
7411 /* Make sure the range is really isolated. */
7412 if (test_pages_isolated(outer_start
, end
, false)) {
7413 pr_info("%s: [%lx, %lx) PFNs busy\n",
7414 __func__
, outer_start
, end
);
7419 /* Grab isolated pages from freelists. */
7420 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7426 /* Free head and tail (if any) */
7427 if (start
!= outer_start
)
7428 free_contig_range(outer_start
, start
- outer_start
);
7429 if (end
!= outer_end
)
7430 free_contig_range(end
, outer_end
- end
);
7433 undo_isolate_page_range(pfn_max_align_down(start
),
7434 pfn_max_align_up(end
), migratetype
);
7438 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7440 unsigned int count
= 0;
7442 for (; nr_pages
--; pfn
++) {
7443 struct page
*page
= pfn_to_page(pfn
);
7445 count
+= page_count(page
) != 1;
7448 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7452 #ifdef CONFIG_MEMORY_HOTPLUG
7454 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7455 * page high values need to be recalulated.
7457 void __meminit
zone_pcp_update(struct zone
*zone
)
7460 mutex_lock(&pcp_batch_high_lock
);
7461 for_each_possible_cpu(cpu
)
7462 pageset_set_high_and_batch(zone
,
7463 per_cpu_ptr(zone
->pageset
, cpu
));
7464 mutex_unlock(&pcp_batch_high_lock
);
7468 void zone_pcp_reset(struct zone
*zone
)
7470 unsigned long flags
;
7472 struct per_cpu_pageset
*pset
;
7474 /* avoid races with drain_pages() */
7475 local_irq_save(flags
);
7476 if (zone
->pageset
!= &boot_pageset
) {
7477 for_each_online_cpu(cpu
) {
7478 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7479 drain_zonestat(zone
, pset
);
7481 free_percpu(zone
->pageset
);
7482 zone
->pageset
= &boot_pageset
;
7484 local_irq_restore(flags
);
7487 #ifdef CONFIG_MEMORY_HOTREMOVE
7489 * All pages in the range must be in a single zone and isolated
7490 * before calling this.
7493 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7497 unsigned int order
, i
;
7499 unsigned long flags
;
7500 /* find the first valid pfn */
7501 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7506 zone
= page_zone(pfn_to_page(pfn
));
7507 spin_lock_irqsave(&zone
->lock
, flags
);
7509 while (pfn
< end_pfn
) {
7510 if (!pfn_valid(pfn
)) {
7514 page
= pfn_to_page(pfn
);
7516 * The HWPoisoned page may be not in buddy system, and
7517 * page_count() is not 0.
7519 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7521 SetPageReserved(page
);
7525 BUG_ON(page_count(page
));
7526 BUG_ON(!PageBuddy(page
));
7527 order
= page_order(page
);
7528 #ifdef CONFIG_DEBUG_VM
7529 pr_info("remove from free list %lx %d %lx\n",
7530 pfn
, 1 << order
, end_pfn
);
7532 list_del(&page
->lru
);
7533 rmv_page_order(page
);
7534 zone
->free_area
[order
].nr_free
--;
7535 for (i
= 0; i
< (1 << order
); i
++)
7536 SetPageReserved((page
+i
));
7537 pfn
+= (1 << order
);
7539 spin_unlock_irqrestore(&zone
->lock
, flags
);
7543 bool is_free_buddy_page(struct page
*page
)
7545 struct zone
*zone
= page_zone(page
);
7546 unsigned long pfn
= page_to_pfn(page
);
7547 unsigned long flags
;
7550 spin_lock_irqsave(&zone
->lock
, flags
);
7551 for (order
= 0; order
< MAX_ORDER
; order
++) {
7552 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7554 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7557 spin_unlock_irqrestore(&zone
->lock
, flags
);
7559 return order
< MAX_ORDER
;