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
= zone_page_state(zone
, NR_PAGES_SCANNED
);
1083 __mod_zone_page_state(zone
, 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
= zone_page_state(zone
, NR_PAGES_SCANNED
);
1140 __mod_zone_page_state(zone
, 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 zone that is within its dirty
2916 * limit, such that no single zone holds more than its
2917 * proportional share of globally allowed dirty pages.
2918 * The dirty limits take into account the zone'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 * This may look like it could increase pressure on
2924 * lower zones by failing allocations in higher zones
2925 * before they are full. But the pages that do spill
2926 * over are limited as the lower zones are protected
2927 * by this very same mechanism. It should not become
2928 * a practical burden to them.
2930 * XXX: For now, allow allocations to potentially
2931 * exceed the per-zone dirty limit in the slowpath
2932 * (spread_dirty_pages unset) before going into reclaim,
2933 * which is important when on a NUMA setup the allowed
2934 * zones are together not big enough to reach the
2935 * global limit. The proper fix for these situations
2936 * will require awareness of zones in the
2937 * dirty-throttling and the flusher threads.
2939 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2942 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2943 if (!zone_watermark_fast(zone
, order
, mark
,
2944 ac_classzone_idx(ac
), alloc_flags
)) {
2947 /* Checked here to keep the fast path fast */
2948 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2949 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2952 if (zone_reclaim_mode
== 0 ||
2953 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
2956 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2958 case ZONE_RECLAIM_NOSCAN
:
2961 case ZONE_RECLAIM_FULL
:
2962 /* scanned but unreclaimable */
2965 /* did we reclaim enough */
2966 if (zone_watermark_ok(zone
, order
, mark
,
2967 ac_classzone_idx(ac
), alloc_flags
))
2975 page
= buffered_rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
2976 gfp_mask
, alloc_flags
, ac
->migratetype
);
2978 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
2981 * If this is a high-order atomic allocation then check
2982 * if the pageblock should be reserved for the future
2984 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2985 reserve_highatomic_pageblock(page
, zone
, order
);
2992 * The first pass makes sure allocations are spread fairly within the
2993 * local node. However, the local node might have free pages left
2994 * after the fairness batches are exhausted, and remote zones haven't
2995 * even been considered yet. Try once more without fairness, and
2996 * include remote zones now, before entering the slowpath and waking
2997 * kswapd: prefer spilling to a remote zone over swapping locally.
3002 fair_skipped
= false;
3003 reset_alloc_batches(ac
->preferred_zoneref
->zone
);
3004 z
= ac
->preferred_zoneref
;
3012 * Large machines with many possible nodes should not always dump per-node
3013 * meminfo in irq context.
3015 static inline bool should_suppress_show_mem(void)
3020 ret
= in_interrupt();
3025 static DEFINE_RATELIMIT_STATE(nopage_rs
,
3026 DEFAULT_RATELIMIT_INTERVAL
,
3027 DEFAULT_RATELIMIT_BURST
);
3029 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
3031 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3033 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
3034 debug_guardpage_minorder() > 0)
3038 * This documents exceptions given to allocations in certain
3039 * contexts that are allowed to allocate outside current's set
3042 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3043 if (test_thread_flag(TIF_MEMDIE
) ||
3044 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3045 filter
&= ~SHOW_MEM_FILTER_NODES
;
3046 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3047 filter
&= ~SHOW_MEM_FILTER_NODES
;
3050 struct va_format vaf
;
3053 va_start(args
, fmt
);
3058 pr_warn("%pV", &vaf
);
3063 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3064 current
->comm
, order
, gfp_mask
, &gfp_mask
);
3066 if (!should_suppress_show_mem())
3070 static inline struct page
*
3071 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3072 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3074 struct oom_control oc
= {
3075 .zonelist
= ac
->zonelist
,
3076 .nodemask
= ac
->nodemask
,
3078 .gfp_mask
= gfp_mask
,
3083 *did_some_progress
= 0;
3086 * Acquire the oom lock. If that fails, somebody else is
3087 * making progress for us.
3089 if (!mutex_trylock(&oom_lock
)) {
3090 *did_some_progress
= 1;
3091 schedule_timeout_uninterruptible(1);
3096 * Go through the zonelist yet one more time, keep very high watermark
3097 * here, this is only to catch a parallel oom killing, we must fail if
3098 * we're still under heavy pressure.
3100 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3101 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3105 if (!(gfp_mask
& __GFP_NOFAIL
)) {
3106 /* Coredumps can quickly deplete all memory reserves */
3107 if (current
->flags
& PF_DUMPCORE
)
3109 /* The OOM killer will not help higher order allocs */
3110 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3112 /* The OOM killer does not needlessly kill tasks for lowmem */
3113 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3115 if (pm_suspended_storage())
3118 * XXX: GFP_NOFS allocations should rather fail than rely on
3119 * other request to make a forward progress.
3120 * We are in an unfortunate situation where out_of_memory cannot
3121 * do much for this context but let's try it to at least get
3122 * access to memory reserved if the current task is killed (see
3123 * out_of_memory). Once filesystems are ready to handle allocation
3124 * failures more gracefully we should just bail out here.
3127 /* The OOM killer may not free memory on a specific node */
3128 if (gfp_mask
& __GFP_THISNODE
)
3131 /* Exhausted what can be done so it's blamo time */
3132 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3133 *did_some_progress
= 1;
3135 if (gfp_mask
& __GFP_NOFAIL
) {
3136 page
= get_page_from_freelist(gfp_mask
, order
,
3137 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
3139 * fallback to ignore cpuset restriction if our nodes
3143 page
= get_page_from_freelist(gfp_mask
, order
,
3144 ALLOC_NO_WATERMARKS
, ac
);
3148 mutex_unlock(&oom_lock
);
3154 * Maximum number of compaction retries wit a progress before OOM
3155 * killer is consider as the only way to move forward.
3157 #define MAX_COMPACT_RETRIES 16
3159 #ifdef CONFIG_COMPACTION
3160 /* Try memory compaction for high-order allocations before reclaim */
3161 static struct page
*
3162 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3163 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3164 enum migrate_mode mode
, enum compact_result
*compact_result
)
3167 int contended_compaction
;
3172 current
->flags
|= PF_MEMALLOC
;
3173 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3174 mode
, &contended_compaction
);
3175 current
->flags
&= ~PF_MEMALLOC
;
3177 if (*compact_result
<= COMPACT_INACTIVE
)
3181 * At least in one zone compaction wasn't deferred or skipped, so let's
3182 * count a compaction stall
3184 count_vm_event(COMPACTSTALL
);
3186 page
= get_page_from_freelist(gfp_mask
, order
,
3187 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3190 struct zone
*zone
= page_zone(page
);
3192 zone
->compact_blockskip_flush
= false;
3193 compaction_defer_reset(zone
, order
, true);
3194 count_vm_event(COMPACTSUCCESS
);
3199 * It's bad if compaction run occurs and fails. The most likely reason
3200 * is that pages exist, but not enough to satisfy watermarks.
3202 count_vm_event(COMPACTFAIL
);
3205 * In all zones where compaction was attempted (and not
3206 * deferred or skipped), lock contention has been detected.
3207 * For THP allocation we do not want to disrupt the others
3208 * so we fallback to base pages instead.
3210 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3211 *compact_result
= COMPACT_CONTENDED
;
3214 * If compaction was aborted due to need_resched(), we do not
3215 * want to further increase allocation latency, unless it is
3216 * khugepaged trying to collapse.
3218 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3219 && !(current
->flags
& PF_KTHREAD
))
3220 *compact_result
= COMPACT_CONTENDED
;
3228 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3229 enum compact_result compact_result
, enum migrate_mode
*migrate_mode
,
3230 int compaction_retries
)
3232 int max_retries
= MAX_COMPACT_RETRIES
;
3238 * compaction considers all the zone as desperately out of memory
3239 * so it doesn't really make much sense to retry except when the
3240 * failure could be caused by weak migration mode.
3242 if (compaction_failed(compact_result
)) {
3243 if (*migrate_mode
== MIGRATE_ASYNC
) {
3244 *migrate_mode
= MIGRATE_SYNC_LIGHT
;
3251 * make sure the compaction wasn't deferred or didn't bail out early
3252 * due to locks contention before we declare that we should give up.
3253 * But do not retry if the given zonelist is not suitable for
3256 if (compaction_withdrawn(compact_result
))
3257 return compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3260 * !costly requests are much more important than __GFP_REPEAT
3261 * costly ones because they are de facto nofail and invoke OOM
3262 * killer to move on while costly can fail and users are ready
3263 * to cope with that. 1/4 retries is rather arbitrary but we
3264 * would need much more detailed feedback from compaction to
3265 * make a better decision.
3267 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3269 if (compaction_retries
<= max_retries
)
3275 static inline struct page
*
3276 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3277 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3278 enum migrate_mode mode
, enum compact_result
*compact_result
)
3280 *compact_result
= COMPACT_SKIPPED
;
3285 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3286 enum compact_result compact_result
,
3287 enum migrate_mode
*migrate_mode
,
3288 int compaction_retries
)
3293 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3297 * There are setups with compaction disabled which would prefer to loop
3298 * inside the allocator rather than hit the oom killer prematurely.
3299 * Let's give them a good hope and keep retrying while the order-0
3300 * watermarks are OK.
3302 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3304 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3305 ac_classzone_idx(ac
), alloc_flags
))
3310 #endif /* CONFIG_COMPACTION */
3312 /* Perform direct synchronous page reclaim */
3314 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3315 const struct alloc_context
*ac
)
3317 struct reclaim_state reclaim_state
;
3322 /* We now go into synchronous reclaim */
3323 cpuset_memory_pressure_bump();
3324 current
->flags
|= PF_MEMALLOC
;
3325 lockdep_set_current_reclaim_state(gfp_mask
);
3326 reclaim_state
.reclaimed_slab
= 0;
3327 current
->reclaim_state
= &reclaim_state
;
3329 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3332 current
->reclaim_state
= NULL
;
3333 lockdep_clear_current_reclaim_state();
3334 current
->flags
&= ~PF_MEMALLOC
;
3341 /* The really slow allocator path where we enter direct reclaim */
3342 static inline struct page
*
3343 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3344 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3345 unsigned long *did_some_progress
)
3347 struct page
*page
= NULL
;
3348 bool drained
= false;
3350 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3351 if (unlikely(!(*did_some_progress
)))
3355 page
= get_page_from_freelist(gfp_mask
, order
,
3356 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3359 * If an allocation failed after direct reclaim, it could be because
3360 * pages are pinned on the per-cpu lists or in high alloc reserves.
3361 * Shrink them them and try again
3363 if (!page
&& !drained
) {
3364 unreserve_highatomic_pageblock(ac
);
3365 drain_all_pages(NULL
);
3373 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3378 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3379 ac
->high_zoneidx
, ac
->nodemask
)
3380 wakeup_kswapd(zone
, order
, ac_classzone_idx(ac
));
3383 static inline unsigned int
3384 gfp_to_alloc_flags(gfp_t gfp_mask
)
3386 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3388 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3389 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3392 * The caller may dip into page reserves a bit more if the caller
3393 * cannot run direct reclaim, or if the caller has realtime scheduling
3394 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3395 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3397 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3399 if (gfp_mask
& __GFP_ATOMIC
) {
3401 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3402 * if it can't schedule.
3404 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3405 alloc_flags
|= ALLOC_HARDER
;
3407 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3408 * comment for __cpuset_node_allowed().
3410 alloc_flags
&= ~ALLOC_CPUSET
;
3411 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3412 alloc_flags
|= ALLOC_HARDER
;
3414 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3415 if (gfp_mask
& __GFP_MEMALLOC
)
3416 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3417 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3418 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3419 else if (!in_interrupt() &&
3420 ((current
->flags
& PF_MEMALLOC
) ||
3421 unlikely(test_thread_flag(TIF_MEMDIE
))))
3422 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3425 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3426 alloc_flags
|= ALLOC_CMA
;
3431 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3433 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3436 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3438 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3442 * Maximum number of reclaim retries without any progress before OOM killer
3443 * is consider as the only way to move forward.
3445 #define MAX_RECLAIM_RETRIES 16
3448 * Checks whether it makes sense to retry the reclaim to make a forward progress
3449 * for the given allocation request.
3450 * The reclaim feedback represented by did_some_progress (any progress during
3451 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3452 * any progress in a row) is considered as well as the reclaimable pages on the
3453 * applicable zone list (with a backoff mechanism which is a function of
3454 * no_progress_loops).
3456 * Returns true if a retry is viable or false to enter the oom path.
3459 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3460 struct alloc_context
*ac
, int alloc_flags
,
3461 bool did_some_progress
, int no_progress_loops
)
3467 * Make sure we converge to OOM if we cannot make any progress
3468 * several times in the row.
3470 if (no_progress_loops
> MAX_RECLAIM_RETRIES
)
3474 * Keep reclaiming pages while there is a chance this will lead somewhere.
3475 * If none of the target zones can satisfy our allocation request even
3476 * if all reclaimable pages are considered then we are screwed and have
3479 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3481 unsigned long available
;
3482 unsigned long reclaimable
;
3484 available
= reclaimable
= zone_reclaimable_pages(zone
);
3485 available
-= DIV_ROUND_UP(no_progress_loops
* available
,
3486 MAX_RECLAIM_RETRIES
);
3487 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3490 * Would the allocation succeed if we reclaimed the whole
3493 if (__zone_watermark_ok(zone
, order
, min_wmark_pages(zone
),
3494 ac_classzone_idx(ac
), alloc_flags
, available
)) {
3496 * If we didn't make any progress and have a lot of
3497 * dirty + writeback pages then we should wait for
3498 * an IO to complete to slow down the reclaim and
3499 * prevent from pre mature OOM
3501 if (!did_some_progress
) {
3502 unsigned long writeback
;
3503 unsigned long dirty
;
3505 writeback
= zone_page_state_snapshot(zone
,
3507 dirty
= zone_page_state_snapshot(zone
, NR_FILE_DIRTY
);
3509 if (2*(writeback
+ dirty
) > reclaimable
) {
3510 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3516 * Memory allocation/reclaim might be called from a WQ
3517 * context and the current implementation of the WQ
3518 * concurrency control doesn't recognize that
3519 * a particular WQ is congested if the worker thread is
3520 * looping without ever sleeping. Therefore we have to
3521 * do a short sleep here rather than calling
3524 if (current
->flags
& PF_WQ_WORKER
)
3525 schedule_timeout_uninterruptible(1);
3536 static inline struct page
*
3537 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3538 struct alloc_context
*ac
)
3540 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3541 struct page
*page
= NULL
;
3542 unsigned int alloc_flags
;
3543 unsigned long did_some_progress
;
3544 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3545 enum compact_result compact_result
;
3546 int compaction_retries
= 0;
3547 int no_progress_loops
= 0;
3550 * In the slowpath, we sanity check order to avoid ever trying to
3551 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3552 * be using allocators in order of preference for an area that is
3555 if (order
>= MAX_ORDER
) {
3556 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3561 * We also sanity check to catch abuse of atomic reserves being used by
3562 * callers that are not in atomic context.
3564 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3565 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3566 gfp_mask
&= ~__GFP_ATOMIC
;
3569 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3570 wake_all_kswapds(order
, ac
);
3573 * OK, we're below the kswapd watermark and have kicked background
3574 * reclaim. Now things get more complex, so set up alloc_flags according
3575 * to how we want to proceed.
3577 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3580 * Reset the zonelist iterators if memory policies can be ignored.
3581 * These allocations are high priority and system rather than user
3584 if ((alloc_flags
& ALLOC_NO_WATERMARKS
) || !(alloc_flags
& ALLOC_CPUSET
)) {
3585 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3586 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3587 ac
->high_zoneidx
, ac
->nodemask
);
3590 /* This is the last chance, in general, before the goto nopage. */
3591 page
= get_page_from_freelist(gfp_mask
, order
,
3592 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3596 /* Allocate without watermarks if the context allows */
3597 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3598 page
= get_page_from_freelist(gfp_mask
, order
,
3599 ALLOC_NO_WATERMARKS
, ac
);
3604 /* Caller is not willing to reclaim, we can't balance anything */
3605 if (!can_direct_reclaim
) {
3607 * All existing users of the __GFP_NOFAIL are blockable, so warn
3608 * of any new users that actually allow this type of allocation
3611 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3615 /* Avoid recursion of direct reclaim */
3616 if (current
->flags
& PF_MEMALLOC
) {
3618 * __GFP_NOFAIL request from this context is rather bizarre
3619 * because we cannot reclaim anything and only can loop waiting
3620 * for somebody to do a work for us.
3622 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3629 /* Avoid allocations with no watermarks from looping endlessly */
3630 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3634 * Try direct compaction. The first pass is asynchronous. Subsequent
3635 * attempts after direct reclaim are synchronous
3637 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3643 /* Checks for THP-specific high-order allocations */
3644 if (is_thp_gfp_mask(gfp_mask
)) {
3646 * If compaction is deferred for high-order allocations, it is
3647 * because sync compaction recently failed. If this is the case
3648 * and the caller requested a THP allocation, we do not want
3649 * to heavily disrupt the system, so we fail the allocation
3650 * instead of entering direct reclaim.
3652 if (compact_result
== COMPACT_DEFERRED
)
3656 * Compaction is contended so rather back off than cause
3659 if(compact_result
== COMPACT_CONTENDED
)
3663 if (order
&& compaction_made_progress(compact_result
))
3664 compaction_retries
++;
3666 /* Try direct reclaim and then allocating */
3667 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3668 &did_some_progress
);
3672 /* Do not loop if specifically requested */
3673 if (gfp_mask
& __GFP_NORETRY
)
3677 * Do not retry costly high order allocations unless they are
3680 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_REPEAT
))
3684 * Costly allocations might have made a progress but this doesn't mean
3685 * their order will become available due to high fragmentation so
3686 * always increment the no progress counter for them
3688 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3689 no_progress_loops
= 0;
3691 no_progress_loops
++;
3693 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3694 did_some_progress
> 0, no_progress_loops
))
3698 * It doesn't make any sense to retry for the compaction if the order-0
3699 * reclaim is not able to make any progress because the current
3700 * implementation of the compaction depends on the sufficient amount
3701 * of free memory (see __compaction_suitable)
3703 if (did_some_progress
> 0 &&
3704 should_compact_retry(ac
, order
, alloc_flags
,
3705 compact_result
, &migration_mode
,
3706 compaction_retries
))
3709 /* Reclaim has failed us, start killing things */
3710 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3714 /* Retry as long as the OOM killer is making progress */
3715 if (did_some_progress
) {
3716 no_progress_loops
= 0;
3722 * High-order allocations do not necessarily loop after direct reclaim
3723 * and reclaim/compaction depends on compaction being called after
3724 * reclaim so call directly if necessary.
3725 * It can become very expensive to allocate transparent hugepages at
3726 * fault, so use asynchronous memory compaction for THP unless it is
3727 * khugepaged trying to collapse. All other requests should tolerate
3728 * at least light sync migration.
3730 if (is_thp_gfp_mask(gfp_mask
) && !(current
->flags
& PF_KTHREAD
))
3731 migration_mode
= MIGRATE_ASYNC
;
3733 migration_mode
= MIGRATE_SYNC_LIGHT
;
3734 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3740 warn_alloc_failed(gfp_mask
, order
, NULL
);
3746 * This is the 'heart' of the zoned buddy allocator.
3749 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3750 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3753 unsigned int cpuset_mems_cookie
;
3754 unsigned int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_FAIR
;
3755 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
3756 struct alloc_context ac
= {
3757 .high_zoneidx
= gfp_zone(gfp_mask
),
3758 .zonelist
= zonelist
,
3759 .nodemask
= nodemask
,
3760 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3763 if (cpusets_enabled()) {
3764 alloc_mask
|= __GFP_HARDWALL
;
3765 alloc_flags
|= ALLOC_CPUSET
;
3767 ac
.nodemask
= &cpuset_current_mems_allowed
;
3770 gfp_mask
&= gfp_allowed_mask
;
3772 lockdep_trace_alloc(gfp_mask
);
3774 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3776 if (should_fail_alloc_page(gfp_mask
, order
))
3780 * Check the zones suitable for the gfp_mask contain at least one
3781 * valid zone. It's possible to have an empty zonelist as a result
3782 * of __GFP_THISNODE and a memoryless node
3784 if (unlikely(!zonelist
->_zonerefs
->zone
))
3787 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3788 alloc_flags
|= ALLOC_CMA
;
3791 cpuset_mems_cookie
= read_mems_allowed_begin();
3793 /* Dirty zone balancing only done in the fast path */
3794 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3797 * The preferred zone is used for statistics but crucially it is
3798 * also used as the starting point for the zonelist iterator. It
3799 * may get reset for allocations that ignore memory policies.
3801 ac
.preferred_zoneref
= first_zones_zonelist(ac
.zonelist
,
3802 ac
.high_zoneidx
, ac
.nodemask
);
3803 if (!ac
.preferred_zoneref
) {
3808 /* First allocation attempt */
3809 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3814 * Runtime PM, block IO and its error handling path can deadlock
3815 * because I/O on the device might not complete.
3817 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3818 ac
.spread_dirty_pages
= false;
3821 * Restore the original nodemask if it was potentially replaced with
3822 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3824 if (cpusets_enabled())
3825 ac
.nodemask
= nodemask
;
3826 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3830 * When updating a task's mems_allowed, it is possible to race with
3831 * parallel threads in such a way that an allocation can fail while
3832 * the mask is being updated. If a page allocation is about to fail,
3833 * check if the cpuset changed during allocation and if so, retry.
3835 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
))) {
3836 alloc_mask
= gfp_mask
;
3841 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
) {
3842 if (unlikely(memcg_kmem_charge(page
, gfp_mask
, order
))) {
3843 __free_pages(page
, order
);
3846 __SetPageKmemcg(page
);
3849 if (kmemcheck_enabled
&& page
)
3850 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3852 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3856 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3859 * Common helper functions.
3861 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3866 * __get_free_pages() returns a 32-bit address, which cannot represent
3869 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3871 page
= alloc_pages(gfp_mask
, order
);
3874 return (unsigned long) page_address(page
);
3876 EXPORT_SYMBOL(__get_free_pages
);
3878 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3880 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3882 EXPORT_SYMBOL(get_zeroed_page
);
3884 void __free_pages(struct page
*page
, unsigned int order
)
3886 if (put_page_testzero(page
)) {
3888 free_hot_cold_page(page
, false);
3890 __free_pages_ok(page
, order
);
3894 EXPORT_SYMBOL(__free_pages
);
3896 void free_pages(unsigned long addr
, unsigned int order
)
3899 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3900 __free_pages(virt_to_page((void *)addr
), order
);
3904 EXPORT_SYMBOL(free_pages
);
3908 * An arbitrary-length arbitrary-offset area of memory which resides
3909 * within a 0 or higher order page. Multiple fragments within that page
3910 * are individually refcounted, in the page's reference counter.
3912 * The page_frag functions below provide a simple allocation framework for
3913 * page fragments. This is used by the network stack and network device
3914 * drivers to provide a backing region of memory for use as either an
3915 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3917 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3920 struct page
*page
= NULL
;
3921 gfp_t gfp
= gfp_mask
;
3923 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3924 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3926 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3927 PAGE_FRAG_CACHE_MAX_ORDER
);
3928 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3930 if (unlikely(!page
))
3931 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3933 nc
->va
= page
? page_address(page
) : NULL
;
3938 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3939 unsigned int fragsz
, gfp_t gfp_mask
)
3941 unsigned int size
= PAGE_SIZE
;
3945 if (unlikely(!nc
->va
)) {
3947 page
= __page_frag_refill(nc
, gfp_mask
);
3951 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3952 /* if size can vary use size else just use PAGE_SIZE */
3955 /* Even if we own the page, we do not use atomic_set().
3956 * This would break get_page_unless_zero() users.
3958 page_ref_add(page
, size
- 1);
3960 /* reset page count bias and offset to start of new frag */
3961 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3962 nc
->pagecnt_bias
= size
;
3966 offset
= nc
->offset
- fragsz
;
3967 if (unlikely(offset
< 0)) {
3968 page
= virt_to_page(nc
->va
);
3970 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3973 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3974 /* if size can vary use size else just use PAGE_SIZE */
3977 /* OK, page count is 0, we can safely set it */
3978 set_page_count(page
, size
);
3980 /* reset page count bias and offset to start of new frag */
3981 nc
->pagecnt_bias
= size
;
3982 offset
= size
- fragsz
;
3986 nc
->offset
= offset
;
3988 return nc
->va
+ offset
;
3990 EXPORT_SYMBOL(__alloc_page_frag
);
3993 * Frees a page fragment allocated out of either a compound or order 0 page.
3995 void __free_page_frag(void *addr
)
3997 struct page
*page
= virt_to_head_page(addr
);
3999 if (unlikely(put_page_testzero(page
)))
4000 __free_pages_ok(page
, compound_order(page
));
4002 EXPORT_SYMBOL(__free_page_frag
);
4004 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4008 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4009 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4011 split_page(virt_to_page((void *)addr
), order
);
4012 while (used
< alloc_end
) {
4017 return (void *)addr
;
4021 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4022 * @size: the number of bytes to allocate
4023 * @gfp_mask: GFP flags for the allocation
4025 * This function is similar to alloc_pages(), except that it allocates the
4026 * minimum number of pages to satisfy the request. alloc_pages() can only
4027 * allocate memory in power-of-two pages.
4029 * This function is also limited by MAX_ORDER.
4031 * Memory allocated by this function must be released by free_pages_exact().
4033 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4035 unsigned int order
= get_order(size
);
4038 addr
= __get_free_pages(gfp_mask
, order
);
4039 return make_alloc_exact(addr
, order
, size
);
4041 EXPORT_SYMBOL(alloc_pages_exact
);
4044 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4046 * @nid: the preferred node ID where memory should be allocated
4047 * @size: the number of bytes to allocate
4048 * @gfp_mask: GFP flags for the allocation
4050 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4053 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4055 unsigned int order
= get_order(size
);
4056 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4059 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4063 * free_pages_exact - release memory allocated via alloc_pages_exact()
4064 * @virt: the value returned by alloc_pages_exact.
4065 * @size: size of allocation, same value as passed to alloc_pages_exact().
4067 * Release the memory allocated by a previous call to alloc_pages_exact.
4069 void free_pages_exact(void *virt
, size_t size
)
4071 unsigned long addr
= (unsigned long)virt
;
4072 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4074 while (addr
< end
) {
4079 EXPORT_SYMBOL(free_pages_exact
);
4082 * nr_free_zone_pages - count number of pages beyond high watermark
4083 * @offset: The zone index of the highest zone
4085 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4086 * high watermark within all zones at or below a given zone index. For each
4087 * zone, the number of pages is calculated as:
4088 * managed_pages - high_pages
4090 static unsigned long nr_free_zone_pages(int offset
)
4095 /* Just pick one node, since fallback list is circular */
4096 unsigned long sum
= 0;
4098 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4100 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4101 unsigned long size
= zone
->managed_pages
;
4102 unsigned long high
= high_wmark_pages(zone
);
4111 * nr_free_buffer_pages - count number of pages beyond high watermark
4113 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4114 * watermark within ZONE_DMA and ZONE_NORMAL.
4116 unsigned long nr_free_buffer_pages(void)
4118 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4120 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4123 * nr_free_pagecache_pages - count number of pages beyond high watermark
4125 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4126 * high watermark within all zones.
4128 unsigned long nr_free_pagecache_pages(void)
4130 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4133 static inline void show_node(struct zone
*zone
)
4135 if (IS_ENABLED(CONFIG_NUMA
))
4136 printk("Node %d ", zone_to_nid(zone
));
4139 long si_mem_available(void)
4142 unsigned long pagecache
;
4143 unsigned long wmark_low
= 0;
4144 unsigned long pages
[NR_LRU_LISTS
];
4148 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4149 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
4152 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4155 * Estimate the amount of memory available for userspace allocations,
4156 * without causing swapping.
4158 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4161 * Not all the page cache can be freed, otherwise the system will
4162 * start swapping. Assume at least half of the page cache, or the
4163 * low watermark worth of cache, needs to stay.
4165 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4166 pagecache
-= min(pagecache
/ 2, wmark_low
);
4167 available
+= pagecache
;
4170 * Part of the reclaimable slab consists of items that are in use,
4171 * and cannot be freed. Cap this estimate at the low watermark.
4173 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4174 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4180 EXPORT_SYMBOL_GPL(si_mem_available
);
4182 void si_meminfo(struct sysinfo
*val
)
4184 val
->totalram
= totalram_pages
;
4185 val
->sharedram
= global_page_state(NR_SHMEM
);
4186 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4187 val
->bufferram
= nr_blockdev_pages();
4188 val
->totalhigh
= totalhigh_pages
;
4189 val
->freehigh
= nr_free_highpages();
4190 val
->mem_unit
= PAGE_SIZE
;
4193 EXPORT_SYMBOL(si_meminfo
);
4196 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4198 int zone_type
; /* needs to be signed */
4199 unsigned long managed_pages
= 0;
4200 unsigned long managed_highpages
= 0;
4201 unsigned long free_highpages
= 0;
4202 pg_data_t
*pgdat
= NODE_DATA(nid
);
4204 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4205 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4206 val
->totalram
= managed_pages
;
4207 val
->sharedram
= sum_zone_node_page_state(nid
, NR_SHMEM
);
4208 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4209 #ifdef CONFIG_HIGHMEM
4210 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4211 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4213 if (is_highmem(zone
)) {
4214 managed_highpages
+= zone
->managed_pages
;
4215 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4218 val
->totalhigh
= managed_highpages
;
4219 val
->freehigh
= free_highpages
;
4221 val
->totalhigh
= managed_highpages
;
4222 val
->freehigh
= free_highpages
;
4224 val
->mem_unit
= PAGE_SIZE
;
4229 * Determine whether the node should be displayed or not, depending on whether
4230 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4232 bool skip_free_areas_node(unsigned int flags
, int nid
)
4235 unsigned int cpuset_mems_cookie
;
4237 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4241 cpuset_mems_cookie
= read_mems_allowed_begin();
4242 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
4243 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
4248 #define K(x) ((x) << (PAGE_SHIFT-10))
4250 static void show_migration_types(unsigned char type
)
4252 static const char types
[MIGRATE_TYPES
] = {
4253 [MIGRATE_UNMOVABLE
] = 'U',
4254 [MIGRATE_MOVABLE
] = 'M',
4255 [MIGRATE_RECLAIMABLE
] = 'E',
4256 [MIGRATE_HIGHATOMIC
] = 'H',
4258 [MIGRATE_CMA
] = 'C',
4260 #ifdef CONFIG_MEMORY_ISOLATION
4261 [MIGRATE_ISOLATE
] = 'I',
4264 char tmp
[MIGRATE_TYPES
+ 1];
4268 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4269 if (type
& (1 << i
))
4274 printk("(%s) ", tmp
);
4278 * Show free area list (used inside shift_scroll-lock stuff)
4279 * We also calculate the percentage fragmentation. We do this by counting the
4280 * memory on each free list with the exception of the first item on the list.
4283 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4286 void show_free_areas(unsigned int filter
)
4288 unsigned long free_pcp
= 0;
4292 for_each_populated_zone(zone
) {
4293 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4296 for_each_online_cpu(cpu
)
4297 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4300 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4301 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4302 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4303 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4304 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4305 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4306 " anon_thp: %lu shmem_thp: %lu shmem_pmdmapped: %lu\n"
4308 " free:%lu free_pcp:%lu free_cma:%lu\n",
4309 global_page_state(NR_ACTIVE_ANON
),
4310 global_page_state(NR_INACTIVE_ANON
),
4311 global_page_state(NR_ISOLATED_ANON
),
4312 global_page_state(NR_ACTIVE_FILE
),
4313 global_page_state(NR_INACTIVE_FILE
),
4314 global_page_state(NR_ISOLATED_FILE
),
4315 global_page_state(NR_UNEVICTABLE
),
4316 global_page_state(NR_FILE_DIRTY
),
4317 global_page_state(NR_WRITEBACK
),
4318 global_page_state(NR_UNSTABLE_NFS
),
4319 global_page_state(NR_SLAB_RECLAIMABLE
),
4320 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4321 global_page_state(NR_FILE_MAPPED
),
4322 global_page_state(NR_SHMEM
),
4323 global_page_state(NR_PAGETABLE
),
4324 global_page_state(NR_BOUNCE
),
4325 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4326 global_page_state(NR_ANON_THPS
) * HPAGE_PMD_NR
,
4327 global_page_state(NR_SHMEM_THPS
) * HPAGE_PMD_NR
,
4328 global_page_state(NR_SHMEM_PMDMAPPED
) * HPAGE_PMD_NR
,
4330 global_page_state(NR_FREE_PAGES
),
4332 global_page_state(NR_FREE_CMA_PAGES
));
4334 for_each_populated_zone(zone
) {
4337 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4341 for_each_online_cpu(cpu
)
4342 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4350 " active_anon:%lukB"
4351 " inactive_anon:%lukB"
4352 " active_file:%lukB"
4353 " inactive_file:%lukB"
4354 " unevictable:%lukB"
4355 " isolated(anon):%lukB"
4356 " isolated(file):%lukB"
4364 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4366 " shmem_pmdmapped: %lukB"
4369 " slab_reclaimable:%lukB"
4370 " slab_unreclaimable:%lukB"
4371 " kernel_stack:%lukB"
4378 " writeback_tmp:%lukB"
4379 " pages_scanned:%lu"
4380 " all_unreclaimable? %s"
4383 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4384 K(min_wmark_pages(zone
)),
4385 K(low_wmark_pages(zone
)),
4386 K(high_wmark_pages(zone
)),
4387 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
4388 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
4389 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
4390 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
4391 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
4392 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
4393 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
4394 K(zone
->present_pages
),
4395 K(zone
->managed_pages
),
4396 K(zone_page_state(zone
, NR_MLOCK
)),
4397 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
4398 K(zone_page_state(zone
, NR_WRITEBACK
)),
4399 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
4400 K(zone_page_state(zone
, NR_SHMEM
)),
4401 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4402 K(zone_page_state(zone
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4403 K(zone_page_state(zone
, NR_SHMEM_PMDMAPPED
)
4405 K(zone_page_state(zone
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4407 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
4408 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
4409 zone_page_state(zone
, NR_KERNEL_STACK
) *
4411 K(zone_page_state(zone
, NR_PAGETABLE
)),
4412 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
4413 K(zone_page_state(zone
, NR_BOUNCE
)),
4415 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4416 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
4417 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
4418 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
4419 (!zone_reclaimable(zone
) ? "yes" : "no")
4421 printk("lowmem_reserve[]:");
4422 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4423 printk(" %ld", zone
->lowmem_reserve
[i
]);
4427 for_each_populated_zone(zone
) {
4429 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4430 unsigned char types
[MAX_ORDER
];
4432 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4435 printk("%s: ", zone
->name
);
4437 spin_lock_irqsave(&zone
->lock
, flags
);
4438 for (order
= 0; order
< MAX_ORDER
; order
++) {
4439 struct free_area
*area
= &zone
->free_area
[order
];
4442 nr
[order
] = area
->nr_free
;
4443 total
+= nr
[order
] << order
;
4446 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4447 if (!list_empty(&area
->free_list
[type
]))
4448 types
[order
] |= 1 << type
;
4451 spin_unlock_irqrestore(&zone
->lock
, flags
);
4452 for (order
= 0; order
< MAX_ORDER
; order
++) {
4453 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4455 show_migration_types(types
[order
]);
4457 printk("= %lukB\n", K(total
));
4460 hugetlb_show_meminfo();
4462 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4464 show_swap_cache_info();
4467 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4469 zoneref
->zone
= zone
;
4470 zoneref
->zone_idx
= zone_idx(zone
);
4474 * Builds allocation fallback zone lists.
4476 * Add all populated zones of a node to the zonelist.
4478 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4482 enum zone_type zone_type
= MAX_NR_ZONES
;
4486 zone
= pgdat
->node_zones
+ zone_type
;
4487 if (populated_zone(zone
)) {
4488 zoneref_set_zone(zone
,
4489 &zonelist
->_zonerefs
[nr_zones
++]);
4490 check_highest_zone(zone_type
);
4492 } while (zone_type
);
4500 * 0 = automatic detection of better ordering.
4501 * 1 = order by ([node] distance, -zonetype)
4502 * 2 = order by (-zonetype, [node] distance)
4504 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4505 * the same zonelist. So only NUMA can configure this param.
4507 #define ZONELIST_ORDER_DEFAULT 0
4508 #define ZONELIST_ORDER_NODE 1
4509 #define ZONELIST_ORDER_ZONE 2
4511 /* zonelist order in the kernel.
4512 * set_zonelist_order() will set this to NODE or ZONE.
4514 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4515 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4519 /* The value user specified ....changed by config */
4520 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4521 /* string for sysctl */
4522 #define NUMA_ZONELIST_ORDER_LEN 16
4523 char numa_zonelist_order
[16] = "default";
4526 * interface for configure zonelist ordering.
4527 * command line option "numa_zonelist_order"
4528 * = "[dD]efault - default, automatic configuration.
4529 * = "[nN]ode - order by node locality, then by zone within node
4530 * = "[zZ]one - order by zone, then by locality within zone
4533 static int __parse_numa_zonelist_order(char *s
)
4535 if (*s
== 'd' || *s
== 'D') {
4536 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4537 } else if (*s
== 'n' || *s
== 'N') {
4538 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4539 } else if (*s
== 'z' || *s
== 'Z') {
4540 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4542 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4548 static __init
int setup_numa_zonelist_order(char *s
)
4555 ret
= __parse_numa_zonelist_order(s
);
4557 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4561 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4564 * sysctl handler for numa_zonelist_order
4566 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4567 void __user
*buffer
, size_t *length
,
4570 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4572 static DEFINE_MUTEX(zl_order_mutex
);
4574 mutex_lock(&zl_order_mutex
);
4576 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4580 strcpy(saved_string
, (char *)table
->data
);
4582 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4586 int oldval
= user_zonelist_order
;
4588 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4591 * bogus value. restore saved string
4593 strncpy((char *)table
->data
, saved_string
,
4594 NUMA_ZONELIST_ORDER_LEN
);
4595 user_zonelist_order
= oldval
;
4596 } else if (oldval
!= user_zonelist_order
) {
4597 mutex_lock(&zonelists_mutex
);
4598 build_all_zonelists(NULL
, NULL
);
4599 mutex_unlock(&zonelists_mutex
);
4603 mutex_unlock(&zl_order_mutex
);
4608 #define MAX_NODE_LOAD (nr_online_nodes)
4609 static int node_load
[MAX_NUMNODES
];
4612 * find_next_best_node - find the next node that should appear in a given node's fallback list
4613 * @node: node whose fallback list we're appending
4614 * @used_node_mask: nodemask_t of already used nodes
4616 * We use a number of factors to determine which is the next node that should
4617 * appear on a given node's fallback list. The node should not have appeared
4618 * already in @node's fallback list, and it should be the next closest node
4619 * according to the distance array (which contains arbitrary distance values
4620 * from each node to each node in the system), and should also prefer nodes
4621 * with no CPUs, since presumably they'll have very little allocation pressure
4622 * on them otherwise.
4623 * It returns -1 if no node is found.
4625 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4628 int min_val
= INT_MAX
;
4629 int best_node
= NUMA_NO_NODE
;
4630 const struct cpumask
*tmp
= cpumask_of_node(0);
4632 /* Use the local node if we haven't already */
4633 if (!node_isset(node
, *used_node_mask
)) {
4634 node_set(node
, *used_node_mask
);
4638 for_each_node_state(n
, N_MEMORY
) {
4640 /* Don't want a node to appear more than once */
4641 if (node_isset(n
, *used_node_mask
))
4644 /* Use the distance array to find the distance */
4645 val
= node_distance(node
, n
);
4647 /* Penalize nodes under us ("prefer the next node") */
4650 /* Give preference to headless and unused nodes */
4651 tmp
= cpumask_of_node(n
);
4652 if (!cpumask_empty(tmp
))
4653 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4655 /* Slight preference for less loaded node */
4656 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4657 val
+= node_load
[n
];
4659 if (val
< min_val
) {
4666 node_set(best_node
, *used_node_mask
);
4673 * Build zonelists ordered by node and zones within node.
4674 * This results in maximum locality--normal zone overflows into local
4675 * DMA zone, if any--but risks exhausting DMA zone.
4677 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4680 struct zonelist
*zonelist
;
4682 zonelist
= &pgdat
->node_zonelists
[0];
4683 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4685 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4686 zonelist
->_zonerefs
[j
].zone
= NULL
;
4687 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4691 * Build gfp_thisnode zonelists
4693 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4696 struct zonelist
*zonelist
;
4698 zonelist
= &pgdat
->node_zonelists
[1];
4699 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4700 zonelist
->_zonerefs
[j
].zone
= NULL
;
4701 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4705 * Build zonelists ordered by zone and nodes within zones.
4706 * This results in conserving DMA zone[s] until all Normal memory is
4707 * exhausted, but results in overflowing to remote node while memory
4708 * may still exist in local DMA zone.
4710 static int node_order
[MAX_NUMNODES
];
4712 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4715 int zone_type
; /* needs to be signed */
4717 struct zonelist
*zonelist
;
4719 zonelist
= &pgdat
->node_zonelists
[0];
4721 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4722 for (j
= 0; j
< nr_nodes
; j
++) {
4723 node
= node_order
[j
];
4724 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4725 if (populated_zone(z
)) {
4727 &zonelist
->_zonerefs
[pos
++]);
4728 check_highest_zone(zone_type
);
4732 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4733 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4736 #if defined(CONFIG_64BIT)
4738 * Devices that require DMA32/DMA are relatively rare and do not justify a
4739 * penalty to every machine in case the specialised case applies. Default
4740 * to Node-ordering on 64-bit NUMA machines
4742 static int default_zonelist_order(void)
4744 return ZONELIST_ORDER_NODE
;
4748 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4749 * by the kernel. If processes running on node 0 deplete the low memory zone
4750 * then reclaim will occur more frequency increasing stalls and potentially
4751 * be easier to OOM if a large percentage of the zone is under writeback or
4752 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4753 * Hence, default to zone ordering on 32-bit.
4755 static int default_zonelist_order(void)
4757 return ZONELIST_ORDER_ZONE
;
4759 #endif /* CONFIG_64BIT */
4761 static void set_zonelist_order(void)
4763 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4764 current_zonelist_order
= default_zonelist_order();
4766 current_zonelist_order
= user_zonelist_order
;
4769 static void build_zonelists(pg_data_t
*pgdat
)
4772 nodemask_t used_mask
;
4773 int local_node
, prev_node
;
4774 struct zonelist
*zonelist
;
4775 unsigned int order
= current_zonelist_order
;
4777 /* initialize zonelists */
4778 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4779 zonelist
= pgdat
->node_zonelists
+ i
;
4780 zonelist
->_zonerefs
[0].zone
= NULL
;
4781 zonelist
->_zonerefs
[0].zone_idx
= 0;
4784 /* NUMA-aware ordering of nodes */
4785 local_node
= pgdat
->node_id
;
4786 load
= nr_online_nodes
;
4787 prev_node
= local_node
;
4788 nodes_clear(used_mask
);
4790 memset(node_order
, 0, sizeof(node_order
));
4793 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4795 * We don't want to pressure a particular node.
4796 * So adding penalty to the first node in same
4797 * distance group to make it round-robin.
4799 if (node_distance(local_node
, node
) !=
4800 node_distance(local_node
, prev_node
))
4801 node_load
[node
] = load
;
4805 if (order
== ZONELIST_ORDER_NODE
)
4806 build_zonelists_in_node_order(pgdat
, node
);
4808 node_order
[i
++] = node
; /* remember order */
4811 if (order
== ZONELIST_ORDER_ZONE
) {
4812 /* calculate node order -- i.e., DMA last! */
4813 build_zonelists_in_zone_order(pgdat
, i
);
4816 build_thisnode_zonelists(pgdat
);
4819 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4821 * Return node id of node used for "local" allocations.
4822 * I.e., first node id of first zone in arg node's generic zonelist.
4823 * Used for initializing percpu 'numa_mem', which is used primarily
4824 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4826 int local_memory_node(int node
)
4830 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4831 gfp_zone(GFP_KERNEL
),
4833 return z
->zone
->node
;
4837 #else /* CONFIG_NUMA */
4839 static void set_zonelist_order(void)
4841 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4844 static void build_zonelists(pg_data_t
*pgdat
)
4846 int node
, local_node
;
4848 struct zonelist
*zonelist
;
4850 local_node
= pgdat
->node_id
;
4852 zonelist
= &pgdat
->node_zonelists
[0];
4853 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4856 * Now we build the zonelist so that it contains the zones
4857 * of all the other nodes.
4858 * We don't want to pressure a particular node, so when
4859 * building the zones for node N, we make sure that the
4860 * zones coming right after the local ones are those from
4861 * node N+1 (modulo N)
4863 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4864 if (!node_online(node
))
4866 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4868 for (node
= 0; node
< local_node
; node
++) {
4869 if (!node_online(node
))
4871 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4874 zonelist
->_zonerefs
[j
].zone
= NULL
;
4875 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4878 #endif /* CONFIG_NUMA */
4881 * Boot pageset table. One per cpu which is going to be used for all
4882 * zones and all nodes. The parameters will be set in such a way
4883 * that an item put on a list will immediately be handed over to
4884 * the buddy list. This is safe since pageset manipulation is done
4885 * with interrupts disabled.
4887 * The boot_pagesets must be kept even after bootup is complete for
4888 * unused processors and/or zones. They do play a role for bootstrapping
4889 * hotplugged processors.
4891 * zoneinfo_show() and maybe other functions do
4892 * not check if the processor is online before following the pageset pointer.
4893 * Other parts of the kernel may not check if the zone is available.
4895 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4896 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4897 static void setup_zone_pageset(struct zone
*zone
);
4900 * Global mutex to protect against size modification of zonelists
4901 * as well as to serialize pageset setup for the new populated zone.
4903 DEFINE_MUTEX(zonelists_mutex
);
4905 /* return values int ....just for stop_machine() */
4906 static int __build_all_zonelists(void *data
)
4910 pg_data_t
*self
= data
;
4913 memset(node_load
, 0, sizeof(node_load
));
4916 if (self
&& !node_online(self
->node_id
)) {
4917 build_zonelists(self
);
4920 for_each_online_node(nid
) {
4921 pg_data_t
*pgdat
= NODE_DATA(nid
);
4923 build_zonelists(pgdat
);
4927 * Initialize the boot_pagesets that are going to be used
4928 * for bootstrapping processors. The real pagesets for
4929 * each zone will be allocated later when the per cpu
4930 * allocator is available.
4932 * boot_pagesets are used also for bootstrapping offline
4933 * cpus if the system is already booted because the pagesets
4934 * are needed to initialize allocators on a specific cpu too.
4935 * F.e. the percpu allocator needs the page allocator which
4936 * needs the percpu allocator in order to allocate its pagesets
4937 * (a chicken-egg dilemma).
4939 for_each_possible_cpu(cpu
) {
4940 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4942 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4944 * We now know the "local memory node" for each node--
4945 * i.e., the node of the first zone in the generic zonelist.
4946 * Set up numa_mem percpu variable for on-line cpus. During
4947 * boot, only the boot cpu should be on-line; we'll init the
4948 * secondary cpus' numa_mem as they come on-line. During
4949 * node/memory hotplug, we'll fixup all on-line cpus.
4951 if (cpu_online(cpu
))
4952 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4959 static noinline
void __init
4960 build_all_zonelists_init(void)
4962 __build_all_zonelists(NULL
);
4963 mminit_verify_zonelist();
4964 cpuset_init_current_mems_allowed();
4968 * Called with zonelists_mutex held always
4969 * unless system_state == SYSTEM_BOOTING.
4971 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4972 * [we're only called with non-NULL zone through __meminit paths] and
4973 * (2) call of __init annotated helper build_all_zonelists_init
4974 * [protected by SYSTEM_BOOTING].
4976 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4978 set_zonelist_order();
4980 if (system_state
== SYSTEM_BOOTING
) {
4981 build_all_zonelists_init();
4983 #ifdef CONFIG_MEMORY_HOTPLUG
4985 setup_zone_pageset(zone
);
4987 /* we have to stop all cpus to guarantee there is no user
4989 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4990 /* cpuset refresh routine should be here */
4992 vm_total_pages
= nr_free_pagecache_pages();
4994 * Disable grouping by mobility if the number of pages in the
4995 * system is too low to allow the mechanism to work. It would be
4996 * more accurate, but expensive to check per-zone. This check is
4997 * made on memory-hotadd so a system can start with mobility
4998 * disabled and enable it later
5000 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5001 page_group_by_mobility_disabled
= 1;
5003 page_group_by_mobility_disabled
= 0;
5005 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5007 zonelist_order_name
[current_zonelist_order
],
5008 page_group_by_mobility_disabled
? "off" : "on",
5011 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5016 * Helper functions to size the waitqueue hash table.
5017 * Essentially these want to choose hash table sizes sufficiently
5018 * large so that collisions trying to wait on pages are rare.
5019 * But in fact, the number of active page waitqueues on typical
5020 * systems is ridiculously low, less than 200. So this is even
5021 * conservative, even though it seems large.
5023 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
5024 * waitqueues, i.e. the size of the waitq table given the number of pages.
5026 #define PAGES_PER_WAITQUEUE 256
5028 #ifndef CONFIG_MEMORY_HOTPLUG
5029 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5031 unsigned long size
= 1;
5033 pages
/= PAGES_PER_WAITQUEUE
;
5035 while (size
< pages
)
5039 * Once we have dozens or even hundreds of threads sleeping
5040 * on IO we've got bigger problems than wait queue collision.
5041 * Limit the size of the wait table to a reasonable size.
5043 size
= min(size
, 4096UL);
5045 return max(size
, 4UL);
5049 * A zone's size might be changed by hot-add, so it is not possible to determine
5050 * a suitable size for its wait_table. So we use the maximum size now.
5052 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5054 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5055 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5056 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5058 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5059 * or more by the traditional way. (See above). It equals:
5061 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5062 * ia64(16K page size) : = ( 8G + 4M)byte.
5063 * powerpc (64K page size) : = (32G +16M)byte.
5065 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5072 * This is an integer logarithm so that shifts can be used later
5073 * to extract the more random high bits from the multiplicative
5074 * hash function before the remainder is taken.
5076 static inline unsigned long wait_table_bits(unsigned long size
)
5082 * Initially all pages are reserved - free ones are freed
5083 * up by free_all_bootmem() once the early boot process is
5084 * done. Non-atomic initialization, single-pass.
5086 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5087 unsigned long start_pfn
, enum memmap_context context
)
5089 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5090 unsigned long end_pfn
= start_pfn
+ size
;
5091 pg_data_t
*pgdat
= NODE_DATA(nid
);
5093 unsigned long nr_initialised
= 0;
5094 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5095 struct memblock_region
*r
= NULL
, *tmp
;
5098 if (highest_memmap_pfn
< end_pfn
- 1)
5099 highest_memmap_pfn
= end_pfn
- 1;
5102 * Honor reservation requested by the driver for this ZONE_DEVICE
5105 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5106 start_pfn
+= altmap
->reserve
;
5108 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5110 * There can be holes in boot-time mem_map[]s handed to this
5111 * function. They do not exist on hotplugged memory.
5113 if (context
!= MEMMAP_EARLY
)
5116 if (!early_pfn_valid(pfn
))
5118 if (!early_pfn_in_nid(pfn
, nid
))
5120 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5123 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5125 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5126 * from zone_movable_pfn[nid] to end of each node should be
5127 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5129 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
5130 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
5134 * Check given memblock attribute by firmware which can affect
5135 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5136 * mirrored, it's an overlapped memmap init. skip it.
5138 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5139 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5140 for_each_memblock(memory
, tmp
)
5141 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5145 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5146 memblock_is_mirror(r
)) {
5147 /* already initialized as NORMAL */
5148 pfn
= memblock_region_memory_end_pfn(r
);
5156 * Mark the block movable so that blocks are reserved for
5157 * movable at startup. This will force kernel allocations
5158 * to reserve their blocks rather than leaking throughout
5159 * the address space during boot when many long-lived
5160 * kernel allocations are made.
5162 * bitmap is created for zone's valid pfn range. but memmap
5163 * can be created for invalid pages (for alignment)
5164 * check here not to call set_pageblock_migratetype() against
5167 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5168 struct page
*page
= pfn_to_page(pfn
);
5170 __init_single_page(page
, pfn
, zone
, nid
);
5171 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5173 __init_single_pfn(pfn
, zone
, nid
);
5178 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5180 unsigned int order
, t
;
5181 for_each_migratetype_order(order
, t
) {
5182 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5183 zone
->free_area
[order
].nr_free
= 0;
5187 #ifndef __HAVE_ARCH_MEMMAP_INIT
5188 #define memmap_init(size, nid, zone, start_pfn) \
5189 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5192 static int zone_batchsize(struct zone
*zone
)
5198 * The per-cpu-pages pools are set to around 1000th of the
5199 * size of the zone. But no more than 1/2 of a meg.
5201 * OK, so we don't know how big the cache is. So guess.
5203 batch
= zone
->managed_pages
/ 1024;
5204 if (batch
* PAGE_SIZE
> 512 * 1024)
5205 batch
= (512 * 1024) / PAGE_SIZE
;
5206 batch
/= 4; /* We effectively *= 4 below */
5211 * Clamp the batch to a 2^n - 1 value. Having a power
5212 * of 2 value was found to be more likely to have
5213 * suboptimal cache aliasing properties in some cases.
5215 * For example if 2 tasks are alternately allocating
5216 * batches of pages, one task can end up with a lot
5217 * of pages of one half of the possible page colors
5218 * and the other with pages of the other colors.
5220 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5225 /* The deferral and batching of frees should be suppressed under NOMMU
5228 * The problem is that NOMMU needs to be able to allocate large chunks
5229 * of contiguous memory as there's no hardware page translation to
5230 * assemble apparent contiguous memory from discontiguous pages.
5232 * Queueing large contiguous runs of pages for batching, however,
5233 * causes the pages to actually be freed in smaller chunks. As there
5234 * can be a significant delay between the individual batches being
5235 * recycled, this leads to the once large chunks of space being
5236 * fragmented and becoming unavailable for high-order allocations.
5243 * pcp->high and pcp->batch values are related and dependent on one another:
5244 * ->batch must never be higher then ->high.
5245 * The following function updates them in a safe manner without read side
5248 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5249 * those fields changing asynchronously (acording the the above rule).
5251 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5252 * outside of boot time (or some other assurance that no concurrent updaters
5255 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5256 unsigned long batch
)
5258 /* start with a fail safe value for batch */
5262 /* Update high, then batch, in order */
5269 /* a companion to pageset_set_high() */
5270 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5272 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5275 static void pageset_init(struct per_cpu_pageset
*p
)
5277 struct per_cpu_pages
*pcp
;
5280 memset(p
, 0, sizeof(*p
));
5284 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5285 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5288 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5291 pageset_set_batch(p
, batch
);
5295 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5296 * to the value high for the pageset p.
5298 static void pageset_set_high(struct per_cpu_pageset
*p
,
5301 unsigned long batch
= max(1UL, high
/ 4);
5302 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5303 batch
= PAGE_SHIFT
* 8;
5305 pageset_update(&p
->pcp
, high
, batch
);
5308 static void pageset_set_high_and_batch(struct zone
*zone
,
5309 struct per_cpu_pageset
*pcp
)
5311 if (percpu_pagelist_fraction
)
5312 pageset_set_high(pcp
,
5313 (zone
->managed_pages
/
5314 percpu_pagelist_fraction
));
5316 pageset_set_batch(pcp
, zone_batchsize(zone
));
5319 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5321 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5324 pageset_set_high_and_batch(zone
, pcp
);
5327 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5330 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5331 for_each_possible_cpu(cpu
)
5332 zone_pageset_init(zone
, cpu
);
5334 if (!zone
->zone_pgdat
->per_cpu_nodestats
) {
5335 zone
->zone_pgdat
->per_cpu_nodestats
=
5336 alloc_percpu(struct per_cpu_nodestat
);
5341 * Allocate per cpu pagesets and initialize them.
5342 * Before this call only boot pagesets were available.
5344 void __init
setup_per_cpu_pageset(void)
5348 for_each_populated_zone(zone
)
5349 setup_zone_pageset(zone
);
5352 static noinline __init_refok
5353 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
5359 * The per-page waitqueue mechanism uses hashed waitqueues
5362 zone
->wait_table_hash_nr_entries
=
5363 wait_table_hash_nr_entries(zone_size_pages
);
5364 zone
->wait_table_bits
=
5365 wait_table_bits(zone
->wait_table_hash_nr_entries
);
5366 alloc_size
= zone
->wait_table_hash_nr_entries
5367 * sizeof(wait_queue_head_t
);
5369 if (!slab_is_available()) {
5370 zone
->wait_table
= (wait_queue_head_t
*)
5371 memblock_virt_alloc_node_nopanic(
5372 alloc_size
, zone
->zone_pgdat
->node_id
);
5375 * This case means that a zone whose size was 0 gets new memory
5376 * via memory hot-add.
5377 * But it may be the case that a new node was hot-added. In
5378 * this case vmalloc() will not be able to use this new node's
5379 * memory - this wait_table must be initialized to use this new
5380 * node itself as well.
5381 * To use this new node's memory, further consideration will be
5384 zone
->wait_table
= vmalloc(alloc_size
);
5386 if (!zone
->wait_table
)
5389 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
5390 init_waitqueue_head(zone
->wait_table
+ i
);
5395 static __meminit
void zone_pcp_init(struct zone
*zone
)
5398 * per cpu subsystem is not up at this point. The following code
5399 * relies on the ability of the linker to provide the
5400 * offset of a (static) per cpu variable into the per cpu area.
5402 zone
->pageset
= &boot_pageset
;
5404 if (populated_zone(zone
))
5405 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5406 zone
->name
, zone
->present_pages
,
5407 zone_batchsize(zone
));
5410 int __meminit
init_currently_empty_zone(struct zone
*zone
,
5411 unsigned long zone_start_pfn
,
5414 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5416 ret
= zone_wait_table_init(zone
, size
);
5419 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5421 zone
->zone_start_pfn
= zone_start_pfn
;
5423 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5424 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5426 (unsigned long)zone_idx(zone
),
5427 zone_start_pfn
, (zone_start_pfn
+ size
));
5429 zone_init_free_lists(zone
);
5434 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5435 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5438 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5440 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5441 struct mminit_pfnnid_cache
*state
)
5443 unsigned long start_pfn
, end_pfn
;
5446 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5447 return state
->last_nid
;
5449 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5451 state
->last_start
= start_pfn
;
5452 state
->last_end
= end_pfn
;
5453 state
->last_nid
= nid
;
5458 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5461 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5462 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5463 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5465 * If an architecture guarantees that all ranges registered contain no holes
5466 * and may be freed, this this function may be used instead of calling
5467 * memblock_free_early_nid() manually.
5469 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5471 unsigned long start_pfn
, end_pfn
;
5474 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5475 start_pfn
= min(start_pfn
, max_low_pfn
);
5476 end_pfn
= min(end_pfn
, max_low_pfn
);
5478 if (start_pfn
< end_pfn
)
5479 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5480 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5486 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5487 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5489 * If an architecture guarantees that all ranges registered contain no holes and may
5490 * be freed, this function may be used instead of calling memory_present() manually.
5492 void __init
sparse_memory_present_with_active_regions(int nid
)
5494 unsigned long start_pfn
, end_pfn
;
5497 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5498 memory_present(this_nid
, start_pfn
, end_pfn
);
5502 * get_pfn_range_for_nid - Return the start and end page frames for a node
5503 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5504 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5505 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5507 * It returns the start and end page frame of a node based on information
5508 * provided by memblock_set_node(). If called for a node
5509 * with no available memory, a warning is printed and the start and end
5512 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5513 unsigned long *start_pfn
, unsigned long *end_pfn
)
5515 unsigned long this_start_pfn
, this_end_pfn
;
5521 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5522 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5523 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5526 if (*start_pfn
== -1UL)
5531 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5532 * assumption is made that zones within a node are ordered in monotonic
5533 * increasing memory addresses so that the "highest" populated zone is used
5535 static void __init
find_usable_zone_for_movable(void)
5538 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5539 if (zone_index
== ZONE_MOVABLE
)
5542 if (arch_zone_highest_possible_pfn
[zone_index
] >
5543 arch_zone_lowest_possible_pfn
[zone_index
])
5547 VM_BUG_ON(zone_index
== -1);
5548 movable_zone
= zone_index
;
5552 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5553 * because it is sized independent of architecture. Unlike the other zones,
5554 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5555 * in each node depending on the size of each node and how evenly kernelcore
5556 * is distributed. This helper function adjusts the zone ranges
5557 * provided by the architecture for a given node by using the end of the
5558 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5559 * zones within a node are in order of monotonic increases memory addresses
5561 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5562 unsigned long zone_type
,
5563 unsigned long node_start_pfn
,
5564 unsigned long node_end_pfn
,
5565 unsigned long *zone_start_pfn
,
5566 unsigned long *zone_end_pfn
)
5568 /* Only adjust if ZONE_MOVABLE is on this node */
5569 if (zone_movable_pfn
[nid
]) {
5570 /* Size ZONE_MOVABLE */
5571 if (zone_type
== ZONE_MOVABLE
) {
5572 *zone_start_pfn
= zone_movable_pfn
[nid
];
5573 *zone_end_pfn
= min(node_end_pfn
,
5574 arch_zone_highest_possible_pfn
[movable_zone
]);
5576 /* Check if this whole range is within ZONE_MOVABLE */
5577 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5578 *zone_start_pfn
= *zone_end_pfn
;
5583 * Return the number of pages a zone spans in a node, including holes
5584 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5586 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5587 unsigned long zone_type
,
5588 unsigned long node_start_pfn
,
5589 unsigned long node_end_pfn
,
5590 unsigned long *zone_start_pfn
,
5591 unsigned long *zone_end_pfn
,
5592 unsigned long *ignored
)
5594 /* When hotadd a new node from cpu_up(), the node should be empty */
5595 if (!node_start_pfn
&& !node_end_pfn
)
5598 /* Get the start and end of the zone */
5599 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5600 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5601 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5602 node_start_pfn
, node_end_pfn
,
5603 zone_start_pfn
, zone_end_pfn
);
5605 /* Check that this node has pages within the zone's required range */
5606 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5609 /* Move the zone boundaries inside the node if necessary */
5610 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5611 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5613 /* Return the spanned pages */
5614 return *zone_end_pfn
- *zone_start_pfn
;
5618 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5619 * then all holes in the requested range will be accounted for.
5621 unsigned long __meminit
__absent_pages_in_range(int nid
,
5622 unsigned long range_start_pfn
,
5623 unsigned long range_end_pfn
)
5625 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5626 unsigned long start_pfn
, end_pfn
;
5629 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5630 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5631 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5632 nr_absent
-= end_pfn
- start_pfn
;
5638 * absent_pages_in_range - Return number of page frames in holes within a range
5639 * @start_pfn: The start PFN to start searching for holes
5640 * @end_pfn: The end PFN to stop searching for holes
5642 * It returns the number of pages frames in memory holes within a range.
5644 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5645 unsigned long end_pfn
)
5647 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5650 /* Return the number of page frames in holes in a zone on a node */
5651 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5652 unsigned long zone_type
,
5653 unsigned long node_start_pfn
,
5654 unsigned long node_end_pfn
,
5655 unsigned long *ignored
)
5657 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5658 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5659 unsigned long zone_start_pfn
, zone_end_pfn
;
5660 unsigned long nr_absent
;
5662 /* When hotadd a new node from cpu_up(), the node should be empty */
5663 if (!node_start_pfn
&& !node_end_pfn
)
5666 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5667 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5669 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5670 node_start_pfn
, node_end_pfn
,
5671 &zone_start_pfn
, &zone_end_pfn
);
5672 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5675 * ZONE_MOVABLE handling.
5676 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5679 if (zone_movable_pfn
[nid
]) {
5680 if (mirrored_kernelcore
) {
5681 unsigned long start_pfn
, end_pfn
;
5682 struct memblock_region
*r
;
5684 for_each_memblock(memory
, r
) {
5685 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5686 zone_start_pfn
, zone_end_pfn
);
5687 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5688 zone_start_pfn
, zone_end_pfn
);
5690 if (zone_type
== ZONE_MOVABLE
&&
5691 memblock_is_mirror(r
))
5692 nr_absent
+= end_pfn
- start_pfn
;
5694 if (zone_type
== ZONE_NORMAL
&&
5695 !memblock_is_mirror(r
))
5696 nr_absent
+= end_pfn
- start_pfn
;
5699 if (zone_type
== ZONE_NORMAL
)
5700 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5707 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5708 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5709 unsigned long zone_type
,
5710 unsigned long node_start_pfn
,
5711 unsigned long node_end_pfn
,
5712 unsigned long *zone_start_pfn
,
5713 unsigned long *zone_end_pfn
,
5714 unsigned long *zones_size
)
5718 *zone_start_pfn
= node_start_pfn
;
5719 for (zone
= 0; zone
< zone_type
; zone
++)
5720 *zone_start_pfn
+= zones_size
[zone
];
5722 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5724 return zones_size
[zone_type
];
5727 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5728 unsigned long zone_type
,
5729 unsigned long node_start_pfn
,
5730 unsigned long node_end_pfn
,
5731 unsigned long *zholes_size
)
5736 return zholes_size
[zone_type
];
5739 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5741 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5742 unsigned long node_start_pfn
,
5743 unsigned long node_end_pfn
,
5744 unsigned long *zones_size
,
5745 unsigned long *zholes_size
)
5747 unsigned long realtotalpages
= 0, totalpages
= 0;
5750 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5751 struct zone
*zone
= pgdat
->node_zones
+ i
;
5752 unsigned long zone_start_pfn
, zone_end_pfn
;
5753 unsigned long size
, real_size
;
5755 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5761 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5762 node_start_pfn
, node_end_pfn
,
5765 zone
->zone_start_pfn
= zone_start_pfn
;
5767 zone
->zone_start_pfn
= 0;
5768 zone
->spanned_pages
= size
;
5769 zone
->present_pages
= real_size
;
5772 realtotalpages
+= real_size
;
5775 pgdat
->node_spanned_pages
= totalpages
;
5776 pgdat
->node_present_pages
= realtotalpages
;
5777 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5781 #ifndef CONFIG_SPARSEMEM
5783 * Calculate the size of the zone->blockflags rounded to an unsigned long
5784 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5785 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5786 * round what is now in bits to nearest long in bits, then return it in
5789 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5791 unsigned long usemapsize
;
5793 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5794 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5795 usemapsize
= usemapsize
>> pageblock_order
;
5796 usemapsize
*= NR_PAGEBLOCK_BITS
;
5797 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5799 return usemapsize
/ 8;
5802 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5804 unsigned long zone_start_pfn
,
5805 unsigned long zonesize
)
5807 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5808 zone
->pageblock_flags
= NULL
;
5810 zone
->pageblock_flags
=
5811 memblock_virt_alloc_node_nopanic(usemapsize
,
5815 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5816 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5817 #endif /* CONFIG_SPARSEMEM */
5819 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5821 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5822 void __paginginit
set_pageblock_order(void)
5826 /* Check that pageblock_nr_pages has not already been setup */
5827 if (pageblock_order
)
5830 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5831 order
= HUGETLB_PAGE_ORDER
;
5833 order
= MAX_ORDER
- 1;
5836 * Assume the largest contiguous order of interest is a huge page.
5837 * This value may be variable depending on boot parameters on IA64 and
5840 pageblock_order
= order
;
5842 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5845 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5846 * is unused as pageblock_order is set at compile-time. See
5847 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5850 void __paginginit
set_pageblock_order(void)
5854 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5856 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5857 unsigned long present_pages
)
5859 unsigned long pages
= spanned_pages
;
5862 * Provide a more accurate estimation if there are holes within
5863 * the zone and SPARSEMEM is in use. If there are holes within the
5864 * zone, each populated memory region may cost us one or two extra
5865 * memmap pages due to alignment because memmap pages for each
5866 * populated regions may not naturally algined on page boundary.
5867 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5869 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5870 IS_ENABLED(CONFIG_SPARSEMEM
))
5871 pages
= present_pages
;
5873 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5877 * Set up the zone data structures:
5878 * - mark all pages reserved
5879 * - mark all memory queues empty
5880 * - clear the memory bitmaps
5882 * NOTE: pgdat should get zeroed by caller.
5884 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5887 int nid
= pgdat
->node_id
;
5890 pgdat_resize_init(pgdat
);
5891 #ifdef CONFIG_NUMA_BALANCING
5892 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5893 pgdat
->numabalancing_migrate_nr_pages
= 0;
5894 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5896 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5897 spin_lock_init(&pgdat
->split_queue_lock
);
5898 INIT_LIST_HEAD(&pgdat
->split_queue
);
5899 pgdat
->split_queue_len
= 0;
5901 init_waitqueue_head(&pgdat
->kswapd_wait
);
5902 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5903 #ifdef CONFIG_COMPACTION
5904 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5906 pgdat_page_ext_init(pgdat
);
5908 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5909 struct zone
*zone
= pgdat
->node_zones
+ j
;
5910 unsigned long size
, realsize
, freesize
, memmap_pages
;
5911 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5913 size
= zone
->spanned_pages
;
5914 realsize
= freesize
= zone
->present_pages
;
5917 * Adjust freesize so that it accounts for how much memory
5918 * is used by this zone for memmap. This affects the watermark
5919 * and per-cpu initialisations
5921 memmap_pages
= calc_memmap_size(size
, realsize
);
5922 if (!is_highmem_idx(j
)) {
5923 if (freesize
>= memmap_pages
) {
5924 freesize
-= memmap_pages
;
5927 " %s zone: %lu pages used for memmap\n",
5928 zone_names
[j
], memmap_pages
);
5930 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5931 zone_names
[j
], memmap_pages
, freesize
);
5934 /* Account for reserved pages */
5935 if (j
== 0 && freesize
> dma_reserve
) {
5936 freesize
-= dma_reserve
;
5937 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5938 zone_names
[0], dma_reserve
);
5941 if (!is_highmem_idx(j
))
5942 nr_kernel_pages
+= freesize
;
5943 /* Charge for highmem memmap if there are enough kernel pages */
5944 else if (nr_kernel_pages
> memmap_pages
* 2)
5945 nr_kernel_pages
-= memmap_pages
;
5946 nr_all_pages
+= freesize
;
5949 * Set an approximate value for lowmem here, it will be adjusted
5950 * when the bootmem allocator frees pages into the buddy system.
5951 * And all highmem pages will be managed by the buddy system.
5953 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5956 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5958 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5960 zone
->name
= zone_names
[j
];
5961 spin_lock_init(&zone
->lock
);
5962 spin_lock_init(&zone
->lru_lock
);
5963 zone_seqlock_init(zone
);
5964 zone
->zone_pgdat
= pgdat
;
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
);
5970 lruvec_init(&zone
->lruvec
);
5974 set_pageblock_order();
5975 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5976 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5978 memmap_init(size
, nid
, j
, zone_start_pfn
);
5982 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5984 unsigned long __maybe_unused start
= 0;
5985 unsigned long __maybe_unused offset
= 0;
5987 /* Skip empty nodes */
5988 if (!pgdat
->node_spanned_pages
)
5991 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5992 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5993 offset
= pgdat
->node_start_pfn
- start
;
5994 /* ia64 gets its own node_mem_map, before this, without bootmem */
5995 if (!pgdat
->node_mem_map
) {
5996 unsigned long size
, end
;
6000 * The zone's endpoints aren't required to be MAX_ORDER
6001 * aligned but the node_mem_map endpoints must be in order
6002 * for the buddy allocator to function correctly.
6004 end
= pgdat_end_pfn(pgdat
);
6005 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6006 size
= (end
- start
) * sizeof(struct page
);
6007 map
= alloc_remap(pgdat
->node_id
, size
);
6009 map
= memblock_virt_alloc_node_nopanic(size
,
6011 pgdat
->node_mem_map
= map
+ offset
;
6013 #ifndef CONFIG_NEED_MULTIPLE_NODES
6015 * With no DISCONTIG, the global mem_map is just set as node 0's
6017 if (pgdat
== NODE_DATA(0)) {
6018 mem_map
= NODE_DATA(0)->node_mem_map
;
6019 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6020 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6022 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6025 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6028 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6029 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6031 pg_data_t
*pgdat
= NODE_DATA(nid
);
6032 unsigned long start_pfn
= 0;
6033 unsigned long end_pfn
= 0;
6035 /* pg_data_t should be reset to zero when it's allocated */
6036 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
6038 reset_deferred_meminit(pgdat
);
6039 pgdat
->node_id
= nid
;
6040 pgdat
->node_start_pfn
= node_start_pfn
;
6041 pgdat
->per_cpu_nodestats
= NULL
;
6042 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6043 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6044 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6045 (u64
)start_pfn
<< PAGE_SHIFT
,
6046 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6048 start_pfn
= node_start_pfn
;
6050 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6051 zones_size
, zholes_size
);
6053 alloc_node_mem_map(pgdat
);
6054 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6055 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6056 nid
, (unsigned long)pgdat
,
6057 (unsigned long)pgdat
->node_mem_map
);
6060 free_area_init_core(pgdat
);
6063 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6065 #if MAX_NUMNODES > 1
6067 * Figure out the number of possible node ids.
6069 void __init
setup_nr_node_ids(void)
6071 unsigned int highest
;
6073 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6074 nr_node_ids
= highest
+ 1;
6079 * node_map_pfn_alignment - determine the maximum internode alignment
6081 * This function should be called after node map is populated and sorted.
6082 * It calculates the maximum power of two alignment which can distinguish
6085 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6086 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6087 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6088 * shifted, 1GiB is enough and this function will indicate so.
6090 * This is used to test whether pfn -> nid mapping of the chosen memory
6091 * model has fine enough granularity to avoid incorrect mapping for the
6092 * populated node map.
6094 * Returns the determined alignment in pfn's. 0 if there is no alignment
6095 * requirement (single node).
6097 unsigned long __init
node_map_pfn_alignment(void)
6099 unsigned long accl_mask
= 0, last_end
= 0;
6100 unsigned long start
, end
, mask
;
6104 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6105 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6112 * Start with a mask granular enough to pin-point to the
6113 * start pfn and tick off bits one-by-one until it becomes
6114 * too coarse to separate the current node from the last.
6116 mask
= ~((1 << __ffs(start
)) - 1);
6117 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6120 /* accumulate all internode masks */
6124 /* convert mask to number of pages */
6125 return ~accl_mask
+ 1;
6128 /* Find the lowest pfn for a node */
6129 static unsigned long __init
find_min_pfn_for_node(int nid
)
6131 unsigned long min_pfn
= ULONG_MAX
;
6132 unsigned long start_pfn
;
6135 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6136 min_pfn
= min(min_pfn
, start_pfn
);
6138 if (min_pfn
== ULONG_MAX
) {
6139 pr_warn("Could not find start_pfn for node %d\n", nid
);
6147 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6149 * It returns the minimum PFN based on information provided via
6150 * memblock_set_node().
6152 unsigned long __init
find_min_pfn_with_active_regions(void)
6154 return find_min_pfn_for_node(MAX_NUMNODES
);
6158 * early_calculate_totalpages()
6159 * Sum pages in active regions for movable zone.
6160 * Populate N_MEMORY for calculating usable_nodes.
6162 static unsigned long __init
early_calculate_totalpages(void)
6164 unsigned long totalpages
= 0;
6165 unsigned long start_pfn
, end_pfn
;
6168 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6169 unsigned long pages
= end_pfn
- start_pfn
;
6171 totalpages
+= pages
;
6173 node_set_state(nid
, N_MEMORY
);
6179 * Find the PFN the Movable zone begins in each node. Kernel memory
6180 * is spread evenly between nodes as long as the nodes have enough
6181 * memory. When they don't, some nodes will have more kernelcore than
6184 static void __init
find_zone_movable_pfns_for_nodes(void)
6187 unsigned long usable_startpfn
;
6188 unsigned long kernelcore_node
, kernelcore_remaining
;
6189 /* save the state before borrow the nodemask */
6190 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6191 unsigned long totalpages
= early_calculate_totalpages();
6192 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6193 struct memblock_region
*r
;
6195 /* Need to find movable_zone earlier when movable_node is specified. */
6196 find_usable_zone_for_movable();
6199 * If movable_node is specified, ignore kernelcore and movablecore
6202 if (movable_node_is_enabled()) {
6203 for_each_memblock(memory
, r
) {
6204 if (!memblock_is_hotpluggable(r
))
6209 usable_startpfn
= PFN_DOWN(r
->base
);
6210 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6211 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6219 * If kernelcore=mirror is specified, ignore movablecore option
6221 if (mirrored_kernelcore
) {
6222 bool mem_below_4gb_not_mirrored
= false;
6224 for_each_memblock(memory
, r
) {
6225 if (memblock_is_mirror(r
))
6230 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6232 if (usable_startpfn
< 0x100000) {
6233 mem_below_4gb_not_mirrored
= true;
6237 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6238 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6242 if (mem_below_4gb_not_mirrored
)
6243 pr_warn("This configuration results in unmirrored kernel memory.");
6249 * If movablecore=nn[KMG] was specified, calculate what size of
6250 * kernelcore that corresponds so that memory usable for
6251 * any allocation type is evenly spread. If both kernelcore
6252 * and movablecore are specified, then the value of kernelcore
6253 * will be used for required_kernelcore if it's greater than
6254 * what movablecore would have allowed.
6256 if (required_movablecore
) {
6257 unsigned long corepages
;
6260 * Round-up so that ZONE_MOVABLE is at least as large as what
6261 * was requested by the user
6263 required_movablecore
=
6264 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6265 required_movablecore
= min(totalpages
, required_movablecore
);
6266 corepages
= totalpages
- required_movablecore
;
6268 required_kernelcore
= max(required_kernelcore
, corepages
);
6272 * If kernelcore was not specified or kernelcore size is larger
6273 * than totalpages, there is no ZONE_MOVABLE.
6275 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6278 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6279 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6282 /* Spread kernelcore memory as evenly as possible throughout nodes */
6283 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6284 for_each_node_state(nid
, N_MEMORY
) {
6285 unsigned long start_pfn
, end_pfn
;
6288 * Recalculate kernelcore_node if the division per node
6289 * now exceeds what is necessary to satisfy the requested
6290 * amount of memory for the kernel
6292 if (required_kernelcore
< kernelcore_node
)
6293 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6296 * As the map is walked, we track how much memory is usable
6297 * by the kernel using kernelcore_remaining. When it is
6298 * 0, the rest of the node is usable by ZONE_MOVABLE
6300 kernelcore_remaining
= kernelcore_node
;
6302 /* Go through each range of PFNs within this node */
6303 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6304 unsigned long size_pages
;
6306 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6307 if (start_pfn
>= end_pfn
)
6310 /* Account for what is only usable for kernelcore */
6311 if (start_pfn
< usable_startpfn
) {
6312 unsigned long kernel_pages
;
6313 kernel_pages
= min(end_pfn
, usable_startpfn
)
6316 kernelcore_remaining
-= min(kernel_pages
,
6317 kernelcore_remaining
);
6318 required_kernelcore
-= min(kernel_pages
,
6319 required_kernelcore
);
6321 /* Continue if range is now fully accounted */
6322 if (end_pfn
<= usable_startpfn
) {
6325 * Push zone_movable_pfn to the end so
6326 * that if we have to rebalance
6327 * kernelcore across nodes, we will
6328 * not double account here
6330 zone_movable_pfn
[nid
] = end_pfn
;
6333 start_pfn
= usable_startpfn
;
6337 * The usable PFN range for ZONE_MOVABLE is from
6338 * start_pfn->end_pfn. Calculate size_pages as the
6339 * number of pages used as kernelcore
6341 size_pages
= end_pfn
- start_pfn
;
6342 if (size_pages
> kernelcore_remaining
)
6343 size_pages
= kernelcore_remaining
;
6344 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6347 * Some kernelcore has been met, update counts and
6348 * break if the kernelcore for this node has been
6351 required_kernelcore
-= min(required_kernelcore
,
6353 kernelcore_remaining
-= size_pages
;
6354 if (!kernelcore_remaining
)
6360 * If there is still required_kernelcore, we do another pass with one
6361 * less node in the count. This will push zone_movable_pfn[nid] further
6362 * along on the nodes that still have memory until kernelcore is
6366 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6370 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6371 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6372 zone_movable_pfn
[nid
] =
6373 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6376 /* restore the node_state */
6377 node_states
[N_MEMORY
] = saved_node_state
;
6380 /* Any regular or high memory on that node ? */
6381 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6383 enum zone_type zone_type
;
6385 if (N_MEMORY
== N_NORMAL_MEMORY
)
6388 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6389 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6390 if (populated_zone(zone
)) {
6391 node_set_state(nid
, N_HIGH_MEMORY
);
6392 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6393 zone_type
<= ZONE_NORMAL
)
6394 node_set_state(nid
, N_NORMAL_MEMORY
);
6401 * free_area_init_nodes - Initialise all pg_data_t and zone data
6402 * @max_zone_pfn: an array of max PFNs for each zone
6404 * This will call free_area_init_node() for each active node in the system.
6405 * Using the page ranges provided by memblock_set_node(), the size of each
6406 * zone in each node and their holes is calculated. If the maximum PFN
6407 * between two adjacent zones match, it is assumed that the zone is empty.
6408 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6409 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6410 * starts where the previous one ended. For example, ZONE_DMA32 starts
6411 * at arch_max_dma_pfn.
6413 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6415 unsigned long start_pfn
, end_pfn
;
6418 /* Record where the zone boundaries are */
6419 memset(arch_zone_lowest_possible_pfn
, 0,
6420 sizeof(arch_zone_lowest_possible_pfn
));
6421 memset(arch_zone_highest_possible_pfn
, 0,
6422 sizeof(arch_zone_highest_possible_pfn
));
6424 start_pfn
= find_min_pfn_with_active_regions();
6426 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6427 if (i
== ZONE_MOVABLE
)
6430 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6431 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6432 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6434 start_pfn
= end_pfn
;
6436 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
6437 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
6439 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6440 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6441 find_zone_movable_pfns_for_nodes();
6443 /* Print out the zone ranges */
6444 pr_info("Zone ranges:\n");
6445 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6446 if (i
== ZONE_MOVABLE
)
6448 pr_info(" %-8s ", zone_names
[i
]);
6449 if (arch_zone_lowest_possible_pfn
[i
] ==
6450 arch_zone_highest_possible_pfn
[i
])
6453 pr_cont("[mem %#018Lx-%#018Lx]\n",
6454 (u64
)arch_zone_lowest_possible_pfn
[i
]
6456 ((u64
)arch_zone_highest_possible_pfn
[i
]
6457 << PAGE_SHIFT
) - 1);
6460 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6461 pr_info("Movable zone start for each node\n");
6462 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6463 if (zone_movable_pfn
[i
])
6464 pr_info(" Node %d: %#018Lx\n", i
,
6465 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6468 /* Print out the early node map */
6469 pr_info("Early memory node ranges\n");
6470 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6471 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6472 (u64
)start_pfn
<< PAGE_SHIFT
,
6473 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6475 /* Initialise every node */
6476 mminit_verify_pageflags_layout();
6477 setup_nr_node_ids();
6478 for_each_online_node(nid
) {
6479 pg_data_t
*pgdat
= NODE_DATA(nid
);
6480 free_area_init_node(nid
, NULL
,
6481 find_min_pfn_for_node(nid
), NULL
);
6483 /* Any memory on that node */
6484 if (pgdat
->node_present_pages
)
6485 node_set_state(nid
, N_MEMORY
);
6486 check_for_memory(pgdat
, nid
);
6490 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6492 unsigned long long coremem
;
6496 coremem
= memparse(p
, &p
);
6497 *core
= coremem
>> PAGE_SHIFT
;
6499 /* Paranoid check that UL is enough for the coremem value */
6500 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6506 * kernelcore=size sets the amount of memory for use for allocations that
6507 * cannot be reclaimed or migrated.
6509 static int __init
cmdline_parse_kernelcore(char *p
)
6511 /* parse kernelcore=mirror */
6512 if (parse_option_str(p
, "mirror")) {
6513 mirrored_kernelcore
= true;
6517 return cmdline_parse_core(p
, &required_kernelcore
);
6521 * movablecore=size sets the amount of memory for use for allocations that
6522 * can be reclaimed or migrated.
6524 static int __init
cmdline_parse_movablecore(char *p
)
6526 return cmdline_parse_core(p
, &required_movablecore
);
6529 early_param("kernelcore", cmdline_parse_kernelcore
);
6530 early_param("movablecore", cmdline_parse_movablecore
);
6532 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6534 void adjust_managed_page_count(struct page
*page
, long count
)
6536 spin_lock(&managed_page_count_lock
);
6537 page_zone(page
)->managed_pages
+= count
;
6538 totalram_pages
+= count
;
6539 #ifdef CONFIG_HIGHMEM
6540 if (PageHighMem(page
))
6541 totalhigh_pages
+= count
;
6543 spin_unlock(&managed_page_count_lock
);
6545 EXPORT_SYMBOL(adjust_managed_page_count
);
6547 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6550 unsigned long pages
= 0;
6552 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6553 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6554 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6555 if ((unsigned int)poison
<= 0xFF)
6556 memset(pos
, poison
, PAGE_SIZE
);
6557 free_reserved_page(virt_to_page(pos
));
6561 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6562 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6566 EXPORT_SYMBOL(free_reserved_area
);
6568 #ifdef CONFIG_HIGHMEM
6569 void free_highmem_page(struct page
*page
)
6571 __free_reserved_page(page
);
6573 page_zone(page
)->managed_pages
++;
6579 void __init
mem_init_print_info(const char *str
)
6581 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6582 unsigned long init_code_size
, init_data_size
;
6584 physpages
= get_num_physpages();
6585 codesize
= _etext
- _stext
;
6586 datasize
= _edata
- _sdata
;
6587 rosize
= __end_rodata
- __start_rodata
;
6588 bss_size
= __bss_stop
- __bss_start
;
6589 init_data_size
= __init_end
- __init_begin
;
6590 init_code_size
= _einittext
- _sinittext
;
6593 * Detect special cases and adjust section sizes accordingly:
6594 * 1) .init.* may be embedded into .data sections
6595 * 2) .init.text.* may be out of [__init_begin, __init_end],
6596 * please refer to arch/tile/kernel/vmlinux.lds.S.
6597 * 3) .rodata.* may be embedded into .text or .data sections.
6599 #define adj_init_size(start, end, size, pos, adj) \
6601 if (start <= pos && pos < end && size > adj) \
6605 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6606 _sinittext
, init_code_size
);
6607 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6608 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6609 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6610 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6612 #undef adj_init_size
6614 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6615 #ifdef CONFIG_HIGHMEM
6619 nr_free_pages() << (PAGE_SHIFT
- 10),
6620 physpages
<< (PAGE_SHIFT
- 10),
6621 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6622 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6623 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6624 totalcma_pages
<< (PAGE_SHIFT
- 10),
6625 #ifdef CONFIG_HIGHMEM
6626 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6628 str
? ", " : "", str
? str
: "");
6632 * set_dma_reserve - set the specified number of pages reserved in the first zone
6633 * @new_dma_reserve: The number of pages to mark reserved
6635 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6636 * In the DMA zone, a significant percentage may be consumed by kernel image
6637 * and other unfreeable allocations which can skew the watermarks badly. This
6638 * function may optionally be used to account for unfreeable pages in the
6639 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6640 * smaller per-cpu batchsize.
6642 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6644 dma_reserve
= new_dma_reserve
;
6647 void __init
free_area_init(unsigned long *zones_size
)
6649 free_area_init_node(0, zones_size
,
6650 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6653 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6654 unsigned long action
, void *hcpu
)
6656 int cpu
= (unsigned long)hcpu
;
6658 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6659 lru_add_drain_cpu(cpu
);
6663 * Spill the event counters of the dead processor
6664 * into the current processors event counters.
6665 * This artificially elevates the count of the current
6668 vm_events_fold_cpu(cpu
);
6671 * Zero the differential counters of the dead processor
6672 * so that the vm statistics are consistent.
6674 * This is only okay since the processor is dead and cannot
6675 * race with what we are doing.
6677 cpu_vm_stats_fold(cpu
);
6682 void __init
page_alloc_init(void)
6684 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6688 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6689 * or min_free_kbytes changes.
6691 static void calculate_totalreserve_pages(void)
6693 struct pglist_data
*pgdat
;
6694 unsigned long reserve_pages
= 0;
6695 enum zone_type i
, j
;
6697 for_each_online_pgdat(pgdat
) {
6698 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6699 struct zone
*zone
= pgdat
->node_zones
+ i
;
6702 /* Find valid and maximum lowmem_reserve in the zone */
6703 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6704 if (zone
->lowmem_reserve
[j
] > max
)
6705 max
= zone
->lowmem_reserve
[j
];
6708 /* we treat the high watermark as reserved pages. */
6709 max
+= high_wmark_pages(zone
);
6711 if (max
> zone
->managed_pages
)
6712 max
= zone
->managed_pages
;
6714 zone
->totalreserve_pages
= max
;
6716 reserve_pages
+= max
;
6719 totalreserve_pages
= reserve_pages
;
6723 * setup_per_zone_lowmem_reserve - called whenever
6724 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6725 * has a correct pages reserved value, so an adequate number of
6726 * pages are left in the zone after a successful __alloc_pages().
6728 static void setup_per_zone_lowmem_reserve(void)
6730 struct pglist_data
*pgdat
;
6731 enum zone_type j
, idx
;
6733 for_each_online_pgdat(pgdat
) {
6734 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6735 struct zone
*zone
= pgdat
->node_zones
+ j
;
6736 unsigned long managed_pages
= zone
->managed_pages
;
6738 zone
->lowmem_reserve
[j
] = 0;
6742 struct zone
*lower_zone
;
6746 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6747 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6749 lower_zone
= pgdat
->node_zones
+ idx
;
6750 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6751 sysctl_lowmem_reserve_ratio
[idx
];
6752 managed_pages
+= lower_zone
->managed_pages
;
6757 /* update totalreserve_pages */
6758 calculate_totalreserve_pages();
6761 static void __setup_per_zone_wmarks(void)
6763 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6764 unsigned long lowmem_pages
= 0;
6766 unsigned long flags
;
6768 /* Calculate total number of !ZONE_HIGHMEM pages */
6769 for_each_zone(zone
) {
6770 if (!is_highmem(zone
))
6771 lowmem_pages
+= zone
->managed_pages
;
6774 for_each_zone(zone
) {
6777 spin_lock_irqsave(&zone
->lock
, flags
);
6778 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6779 do_div(tmp
, lowmem_pages
);
6780 if (is_highmem(zone
)) {
6782 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6783 * need highmem pages, so cap pages_min to a small
6786 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6787 * deltas control asynch page reclaim, and so should
6788 * not be capped for highmem.
6790 unsigned long min_pages
;
6792 min_pages
= zone
->managed_pages
/ 1024;
6793 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6794 zone
->watermark
[WMARK_MIN
] = min_pages
;
6797 * If it's a lowmem zone, reserve a number of pages
6798 * proportionate to the zone's size.
6800 zone
->watermark
[WMARK_MIN
] = tmp
;
6804 * Set the kswapd watermarks distance according to the
6805 * scale factor in proportion to available memory, but
6806 * ensure a minimum size on small systems.
6808 tmp
= max_t(u64
, tmp
>> 2,
6809 mult_frac(zone
->managed_pages
,
6810 watermark_scale_factor
, 10000));
6812 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6813 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6815 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6816 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6817 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6819 spin_unlock_irqrestore(&zone
->lock
, flags
);
6822 /* update totalreserve_pages */
6823 calculate_totalreserve_pages();
6827 * setup_per_zone_wmarks - called when min_free_kbytes changes
6828 * or when memory is hot-{added|removed}
6830 * Ensures that the watermark[min,low,high] values for each zone are set
6831 * correctly with respect to min_free_kbytes.
6833 void setup_per_zone_wmarks(void)
6835 mutex_lock(&zonelists_mutex
);
6836 __setup_per_zone_wmarks();
6837 mutex_unlock(&zonelists_mutex
);
6841 * Initialise min_free_kbytes.
6843 * For small machines we want it small (128k min). For large machines
6844 * we want it large (64MB max). But it is not linear, because network
6845 * bandwidth does not increase linearly with machine size. We use
6847 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6848 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6864 int __meminit
init_per_zone_wmark_min(void)
6866 unsigned long lowmem_kbytes
;
6867 int new_min_free_kbytes
;
6869 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6870 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6872 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6873 min_free_kbytes
= new_min_free_kbytes
;
6874 if (min_free_kbytes
< 128)
6875 min_free_kbytes
= 128;
6876 if (min_free_kbytes
> 65536)
6877 min_free_kbytes
= 65536;
6879 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6880 new_min_free_kbytes
, user_min_free_kbytes
);
6882 setup_per_zone_wmarks();
6883 refresh_zone_stat_thresholds();
6884 setup_per_zone_lowmem_reserve();
6887 core_initcall(init_per_zone_wmark_min
)
6890 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6891 * that we can call two helper functions whenever min_free_kbytes
6894 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6895 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6899 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6904 user_min_free_kbytes
= min_free_kbytes
;
6905 setup_per_zone_wmarks();
6910 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6911 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6915 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6920 setup_per_zone_wmarks();
6926 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6927 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6932 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6937 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6938 sysctl_min_unmapped_ratio
) / 100;
6942 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6943 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6948 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6953 zone
->min_slab_pages
= (zone
->managed_pages
*
6954 sysctl_min_slab_ratio
) / 100;
6960 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6961 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6962 * whenever sysctl_lowmem_reserve_ratio changes.
6964 * The reserve ratio obviously has absolutely no relation with the
6965 * minimum watermarks. The lowmem reserve ratio can only make sense
6966 * if in function of the boot time zone sizes.
6968 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6969 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6971 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6972 setup_per_zone_lowmem_reserve();
6977 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6978 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6979 * pagelist can have before it gets flushed back to buddy allocator.
6981 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6982 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6985 int old_percpu_pagelist_fraction
;
6988 mutex_lock(&pcp_batch_high_lock
);
6989 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6991 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6992 if (!write
|| ret
< 0)
6995 /* Sanity checking to avoid pcp imbalance */
6996 if (percpu_pagelist_fraction
&&
6997 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6998 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7004 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7007 for_each_populated_zone(zone
) {
7010 for_each_possible_cpu(cpu
)
7011 pageset_set_high_and_batch(zone
,
7012 per_cpu_ptr(zone
->pageset
, cpu
));
7015 mutex_unlock(&pcp_batch_high_lock
);
7020 int hashdist
= HASHDIST_DEFAULT
;
7022 static int __init
set_hashdist(char *str
)
7026 hashdist
= simple_strtoul(str
, &str
, 0);
7029 __setup("hashdist=", set_hashdist
);
7033 * allocate a large system hash table from bootmem
7034 * - it is assumed that the hash table must contain an exact power-of-2
7035 * quantity of entries
7036 * - limit is the number of hash buckets, not the total allocation size
7038 void *__init
alloc_large_system_hash(const char *tablename
,
7039 unsigned long bucketsize
,
7040 unsigned long numentries
,
7043 unsigned int *_hash_shift
,
7044 unsigned int *_hash_mask
,
7045 unsigned long low_limit
,
7046 unsigned long high_limit
)
7048 unsigned long long max
= high_limit
;
7049 unsigned long log2qty
, size
;
7052 /* allow the kernel cmdline to have a say */
7054 /* round applicable memory size up to nearest megabyte */
7055 numentries
= nr_kernel_pages
;
7057 /* It isn't necessary when PAGE_SIZE >= 1MB */
7058 if (PAGE_SHIFT
< 20)
7059 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7061 /* limit to 1 bucket per 2^scale bytes of low memory */
7062 if (scale
> PAGE_SHIFT
)
7063 numentries
>>= (scale
- PAGE_SHIFT
);
7065 numentries
<<= (PAGE_SHIFT
- scale
);
7067 /* Make sure we've got at least a 0-order allocation.. */
7068 if (unlikely(flags
& HASH_SMALL
)) {
7069 /* Makes no sense without HASH_EARLY */
7070 WARN_ON(!(flags
& HASH_EARLY
));
7071 if (!(numentries
>> *_hash_shift
)) {
7072 numentries
= 1UL << *_hash_shift
;
7073 BUG_ON(!numentries
);
7075 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7076 numentries
= PAGE_SIZE
/ bucketsize
;
7078 numentries
= roundup_pow_of_two(numentries
);
7080 /* limit allocation size to 1/16 total memory by default */
7082 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7083 do_div(max
, bucketsize
);
7085 max
= min(max
, 0x80000000ULL
);
7087 if (numentries
< low_limit
)
7088 numentries
= low_limit
;
7089 if (numentries
> max
)
7092 log2qty
= ilog2(numentries
);
7095 size
= bucketsize
<< log2qty
;
7096 if (flags
& HASH_EARLY
)
7097 table
= memblock_virt_alloc_nopanic(size
, 0);
7099 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
7102 * If bucketsize is not a power-of-two, we may free
7103 * some pages at the end of hash table which
7104 * alloc_pages_exact() automatically does
7106 if (get_order(size
) < MAX_ORDER
) {
7107 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
7108 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
7111 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7114 panic("Failed to allocate %s hash table\n", tablename
);
7116 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7117 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7120 *_hash_shift
= log2qty
;
7122 *_hash_mask
= (1 << log2qty
) - 1;
7128 * This function checks whether pageblock includes unmovable pages or not.
7129 * If @count is not zero, it is okay to include less @count unmovable pages
7131 * PageLRU check without isolation or lru_lock could race so that
7132 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7133 * expect this function should be exact.
7135 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7136 bool skip_hwpoisoned_pages
)
7138 unsigned long pfn
, iter
, found
;
7142 * For avoiding noise data, lru_add_drain_all() should be called
7143 * If ZONE_MOVABLE, the zone never contains unmovable pages
7145 if (zone_idx(zone
) == ZONE_MOVABLE
)
7147 mt
= get_pageblock_migratetype(page
);
7148 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7151 pfn
= page_to_pfn(page
);
7152 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7153 unsigned long check
= pfn
+ iter
;
7155 if (!pfn_valid_within(check
))
7158 page
= pfn_to_page(check
);
7161 * Hugepages are not in LRU lists, but they're movable.
7162 * We need not scan over tail pages bacause we don't
7163 * handle each tail page individually in migration.
7165 if (PageHuge(page
)) {
7166 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7171 * We can't use page_count without pin a page
7172 * because another CPU can free compound page.
7173 * This check already skips compound tails of THP
7174 * because their page->_refcount is zero at all time.
7176 if (!page_ref_count(page
)) {
7177 if (PageBuddy(page
))
7178 iter
+= (1 << page_order(page
)) - 1;
7183 * The HWPoisoned page may be not in buddy system, and
7184 * page_count() is not 0.
7186 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7192 * If there are RECLAIMABLE pages, we need to check
7193 * it. But now, memory offline itself doesn't call
7194 * shrink_node_slabs() and it still to be fixed.
7197 * If the page is not RAM, page_count()should be 0.
7198 * we don't need more check. This is an _used_ not-movable page.
7200 * The problematic thing here is PG_reserved pages. PG_reserved
7201 * is set to both of a memory hole page and a _used_ kernel
7210 bool is_pageblock_removable_nolock(struct page
*page
)
7216 * We have to be careful here because we are iterating over memory
7217 * sections which are not zone aware so we might end up outside of
7218 * the zone but still within the section.
7219 * We have to take care about the node as well. If the node is offline
7220 * its NODE_DATA will be NULL - see page_zone.
7222 if (!node_online(page_to_nid(page
)))
7225 zone
= page_zone(page
);
7226 pfn
= page_to_pfn(page
);
7227 if (!zone_spans_pfn(zone
, pfn
))
7230 return !has_unmovable_pages(zone
, page
, 0, true);
7233 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7235 static unsigned long pfn_max_align_down(unsigned long pfn
)
7237 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7238 pageblock_nr_pages
) - 1);
7241 static unsigned long pfn_max_align_up(unsigned long pfn
)
7243 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7244 pageblock_nr_pages
));
7247 /* [start, end) must belong to a single zone. */
7248 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7249 unsigned long start
, unsigned long end
)
7251 /* This function is based on compact_zone() from compaction.c. */
7252 unsigned long nr_reclaimed
;
7253 unsigned long pfn
= start
;
7254 unsigned int tries
= 0;
7259 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7260 if (fatal_signal_pending(current
)) {
7265 if (list_empty(&cc
->migratepages
)) {
7266 cc
->nr_migratepages
= 0;
7267 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7273 } else if (++tries
== 5) {
7274 ret
= ret
< 0 ? ret
: -EBUSY
;
7278 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7280 cc
->nr_migratepages
-= nr_reclaimed
;
7282 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7283 NULL
, 0, cc
->mode
, MR_CMA
);
7286 putback_movable_pages(&cc
->migratepages
);
7293 * alloc_contig_range() -- tries to allocate given range of pages
7294 * @start: start PFN to allocate
7295 * @end: one-past-the-last PFN to allocate
7296 * @migratetype: migratetype of the underlaying pageblocks (either
7297 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7298 * in range must have the same migratetype and it must
7299 * be either of the two.
7301 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7302 * aligned, however it's the caller's responsibility to guarantee that
7303 * we are the only thread that changes migrate type of pageblocks the
7306 * The PFN range must belong to a single zone.
7308 * Returns zero on success or negative error code. On success all
7309 * pages which PFN is in [start, end) are allocated for the caller and
7310 * need to be freed with free_contig_range().
7312 int alloc_contig_range(unsigned long start
, unsigned long end
,
7313 unsigned migratetype
)
7315 unsigned long outer_start
, outer_end
;
7319 struct compact_control cc
= {
7320 .nr_migratepages
= 0,
7322 .zone
= page_zone(pfn_to_page(start
)),
7323 .mode
= MIGRATE_SYNC
,
7324 .ignore_skip_hint
= true,
7326 INIT_LIST_HEAD(&cc
.migratepages
);
7329 * What we do here is we mark all pageblocks in range as
7330 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7331 * have different sizes, and due to the way page allocator
7332 * work, we align the range to biggest of the two pages so
7333 * that page allocator won't try to merge buddies from
7334 * different pageblocks and change MIGRATE_ISOLATE to some
7335 * other migration type.
7337 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7338 * migrate the pages from an unaligned range (ie. pages that
7339 * we are interested in). This will put all the pages in
7340 * range back to page allocator as MIGRATE_ISOLATE.
7342 * When this is done, we take the pages in range from page
7343 * allocator removing them from the buddy system. This way
7344 * page allocator will never consider using them.
7346 * This lets us mark the pageblocks back as
7347 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7348 * aligned range but not in the unaligned, original range are
7349 * put back to page allocator so that buddy can use them.
7352 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7353 pfn_max_align_up(end
), migratetype
,
7359 * In case of -EBUSY, we'd like to know which page causes problem.
7360 * So, just fall through. We will check it in test_pages_isolated().
7362 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7363 if (ret
&& ret
!= -EBUSY
)
7367 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7368 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7369 * more, all pages in [start, end) are free in page allocator.
7370 * What we are going to do is to allocate all pages from
7371 * [start, end) (that is remove them from page allocator).
7373 * The only problem is that pages at the beginning and at the
7374 * end of interesting range may be not aligned with pages that
7375 * page allocator holds, ie. they can be part of higher order
7376 * pages. Because of this, we reserve the bigger range and
7377 * once this is done free the pages we are not interested in.
7379 * We don't have to hold zone->lock here because the pages are
7380 * isolated thus they won't get removed from buddy.
7383 lru_add_drain_all();
7384 drain_all_pages(cc
.zone
);
7387 outer_start
= start
;
7388 while (!PageBuddy(pfn_to_page(outer_start
))) {
7389 if (++order
>= MAX_ORDER
) {
7390 outer_start
= start
;
7393 outer_start
&= ~0UL << order
;
7396 if (outer_start
!= start
) {
7397 order
= page_order(pfn_to_page(outer_start
));
7400 * outer_start page could be small order buddy page and
7401 * it doesn't include start page. Adjust outer_start
7402 * in this case to report failed page properly
7403 * on tracepoint in test_pages_isolated()
7405 if (outer_start
+ (1UL << order
) <= start
)
7406 outer_start
= start
;
7409 /* Make sure the range is really isolated. */
7410 if (test_pages_isolated(outer_start
, end
, false)) {
7411 pr_info("%s: [%lx, %lx) PFNs busy\n",
7412 __func__
, outer_start
, end
);
7417 /* Grab isolated pages from freelists. */
7418 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7424 /* Free head and tail (if any) */
7425 if (start
!= outer_start
)
7426 free_contig_range(outer_start
, start
- outer_start
);
7427 if (end
!= outer_end
)
7428 free_contig_range(end
, outer_end
- end
);
7431 undo_isolate_page_range(pfn_max_align_down(start
),
7432 pfn_max_align_up(end
), migratetype
);
7436 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7438 unsigned int count
= 0;
7440 for (; nr_pages
--; pfn
++) {
7441 struct page
*page
= pfn_to_page(pfn
);
7443 count
+= page_count(page
) != 1;
7446 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7450 #ifdef CONFIG_MEMORY_HOTPLUG
7452 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7453 * page high values need to be recalulated.
7455 void __meminit
zone_pcp_update(struct zone
*zone
)
7458 mutex_lock(&pcp_batch_high_lock
);
7459 for_each_possible_cpu(cpu
)
7460 pageset_set_high_and_batch(zone
,
7461 per_cpu_ptr(zone
->pageset
, cpu
));
7462 mutex_unlock(&pcp_batch_high_lock
);
7466 void zone_pcp_reset(struct zone
*zone
)
7468 unsigned long flags
;
7470 struct per_cpu_pageset
*pset
;
7472 /* avoid races with drain_pages() */
7473 local_irq_save(flags
);
7474 if (zone
->pageset
!= &boot_pageset
) {
7475 for_each_online_cpu(cpu
) {
7476 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7477 drain_zonestat(zone
, pset
);
7479 free_percpu(zone
->pageset
);
7480 zone
->pageset
= &boot_pageset
;
7482 local_irq_restore(flags
);
7485 #ifdef CONFIG_MEMORY_HOTREMOVE
7487 * All pages in the range must be in a single zone and isolated
7488 * before calling this.
7491 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7495 unsigned int order
, i
;
7497 unsigned long flags
;
7498 /* find the first valid pfn */
7499 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7504 zone
= page_zone(pfn_to_page(pfn
));
7505 spin_lock_irqsave(&zone
->lock
, flags
);
7507 while (pfn
< end_pfn
) {
7508 if (!pfn_valid(pfn
)) {
7512 page
= pfn_to_page(pfn
);
7514 * The HWPoisoned page may be not in buddy system, and
7515 * page_count() is not 0.
7517 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7519 SetPageReserved(page
);
7523 BUG_ON(page_count(page
));
7524 BUG_ON(!PageBuddy(page
));
7525 order
= page_order(page
);
7526 #ifdef CONFIG_DEBUG_VM
7527 pr_info("remove from free list %lx %d %lx\n",
7528 pfn
, 1 << order
, end_pfn
);
7530 list_del(&page
->lru
);
7531 rmv_page_order(page
);
7532 zone
->free_area
[order
].nr_free
--;
7533 for (i
= 0; i
< (1 << order
); i
++)
7534 SetPageReserved((page
+i
));
7535 pfn
+= (1 << order
);
7537 spin_unlock_irqrestore(&zone
->lock
, flags
);
7541 bool is_free_buddy_page(struct page
*page
)
7543 struct zone
*zone
= page_zone(page
);
7544 unsigned long pfn
= page_to_pfn(page
);
7545 unsigned long flags
;
7548 spin_lock_irqsave(&zone
->lock
, flags
);
7549 for (order
= 0; order
< MAX_ORDER
; order
++) {
7550 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7552 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7555 spin_unlock_irqrestore(&zone
->lock
, flags
);
7557 return order
< MAX_ORDER
;