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
)
298 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
300 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
307 * Returns false when the remaining initialisation should be deferred until
308 * later in the boot cycle when it can be parallelised.
310 static inline bool update_defer_init(pg_data_t
*pgdat
,
311 unsigned long pfn
, unsigned long zone_end
,
312 unsigned long *nr_initialised
)
314 unsigned long max_initialise
;
316 /* Always populate low zones for address-contrained allocations */
317 if (zone_end
< pgdat_end_pfn(pgdat
))
320 * Initialise at least 2G of a node but also take into account that
321 * two large system hashes that can take up 1GB for 0.25TB/node.
323 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
324 (pgdat
->node_spanned_pages
>> 8));
327 if ((*nr_initialised
> max_initialise
) &&
328 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
329 pgdat
->first_deferred_pfn
= pfn
;
336 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
340 static inline bool early_page_uninitialised(unsigned long pfn
)
345 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
350 static inline bool update_defer_init(pg_data_t
*pgdat
,
351 unsigned long pfn
, unsigned long zone_end
,
352 unsigned long *nr_initialised
)
358 /* Return a pointer to the bitmap storing bits affecting a block of pages */
359 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
362 #ifdef CONFIG_SPARSEMEM
363 return __pfn_to_section(pfn
)->pageblock_flags
;
365 return page_zone(page
)->pageblock_flags
;
366 #endif /* CONFIG_SPARSEMEM */
369 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
371 #ifdef CONFIG_SPARSEMEM
372 pfn
&= (PAGES_PER_SECTION
-1);
373 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
375 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
376 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
377 #endif /* CONFIG_SPARSEMEM */
381 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
382 * @page: The page within the block of interest
383 * @pfn: The target page frame number
384 * @end_bitidx: The last bit of interest to retrieve
385 * @mask: mask of bits that the caller is interested in
387 * Return: pageblock_bits flags
389 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
391 unsigned long end_bitidx
,
394 unsigned long *bitmap
;
395 unsigned long bitidx
, word_bitidx
;
398 bitmap
= get_pageblock_bitmap(page
, pfn
);
399 bitidx
= pfn_to_bitidx(page
, pfn
);
400 word_bitidx
= bitidx
/ BITS_PER_LONG
;
401 bitidx
&= (BITS_PER_LONG
-1);
403 word
= bitmap
[word_bitidx
];
404 bitidx
+= end_bitidx
;
405 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
408 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
409 unsigned long end_bitidx
,
412 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
415 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
417 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
421 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
422 * @page: The page within the block of interest
423 * @flags: The flags to set
424 * @pfn: The target page frame number
425 * @end_bitidx: The last bit of interest
426 * @mask: mask of bits that the caller is interested in
428 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
430 unsigned long end_bitidx
,
433 unsigned long *bitmap
;
434 unsigned long bitidx
, word_bitidx
;
435 unsigned long old_word
, word
;
437 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
439 bitmap
= get_pageblock_bitmap(page
, pfn
);
440 bitidx
= pfn_to_bitidx(page
, pfn
);
441 word_bitidx
= bitidx
/ BITS_PER_LONG
;
442 bitidx
&= (BITS_PER_LONG
-1);
444 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
446 bitidx
+= end_bitidx
;
447 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
448 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
450 word
= READ_ONCE(bitmap
[word_bitidx
]);
452 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
453 if (word
== old_word
)
459 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
461 if (unlikely(page_group_by_mobility_disabled
&&
462 migratetype
< MIGRATE_PCPTYPES
))
463 migratetype
= MIGRATE_UNMOVABLE
;
465 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
466 PB_migrate
, PB_migrate_end
);
469 #ifdef CONFIG_DEBUG_VM
470 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
474 unsigned long pfn
= page_to_pfn(page
);
475 unsigned long sp
, start_pfn
;
478 seq
= zone_span_seqbegin(zone
);
479 start_pfn
= zone
->zone_start_pfn
;
480 sp
= zone
->spanned_pages
;
481 if (!zone_spans_pfn(zone
, pfn
))
483 } while (zone_span_seqretry(zone
, seq
));
486 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
487 pfn
, zone_to_nid(zone
), zone
->name
,
488 start_pfn
, start_pfn
+ sp
);
493 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
495 if (!pfn_valid_within(page_to_pfn(page
)))
497 if (zone
!= page_zone(page
))
503 * Temporary debugging check for pages not lying within a given zone.
505 static int bad_range(struct zone
*zone
, struct page
*page
)
507 if (page_outside_zone_boundaries(zone
, page
))
509 if (!page_is_consistent(zone
, page
))
515 static inline int bad_range(struct zone
*zone
, struct page
*page
)
521 static void bad_page(struct page
*page
, const char *reason
,
522 unsigned long bad_flags
)
524 static unsigned long resume
;
525 static unsigned long nr_shown
;
526 static unsigned long nr_unshown
;
529 * Allow a burst of 60 reports, then keep quiet for that minute;
530 * or allow a steady drip of one report per second.
532 if (nr_shown
== 60) {
533 if (time_before(jiffies
, resume
)) {
539 "BUG: Bad page state: %lu messages suppressed\n",
546 resume
= jiffies
+ 60 * HZ
;
548 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
549 current
->comm
, page_to_pfn(page
));
550 __dump_page(page
, reason
);
551 bad_flags
&= page
->flags
;
553 pr_alert("bad because of flags: %#lx(%pGp)\n",
554 bad_flags
, &bad_flags
);
555 dump_page_owner(page
);
560 /* Leave bad fields for debug, except PageBuddy could make trouble */
561 page_mapcount_reset(page
); /* remove PageBuddy */
562 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
566 * Higher-order pages are called "compound pages". They are structured thusly:
568 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
570 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
571 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
573 * The first tail page's ->compound_dtor holds the offset in array of compound
574 * page destructors. See compound_page_dtors.
576 * The first tail page's ->compound_order holds the order of allocation.
577 * This usage means that zero-order pages may not be compound.
580 void free_compound_page(struct page
*page
)
582 __free_pages_ok(page
, compound_order(page
));
585 void prep_compound_page(struct page
*page
, unsigned int order
)
588 int nr_pages
= 1 << order
;
590 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
591 set_compound_order(page
, order
);
593 for (i
= 1; i
< nr_pages
; i
++) {
594 struct page
*p
= page
+ i
;
595 set_page_count(p
, 0);
596 p
->mapping
= TAIL_MAPPING
;
597 set_compound_head(p
, page
);
599 atomic_set(compound_mapcount_ptr(page
), -1);
602 #ifdef CONFIG_DEBUG_PAGEALLOC
603 unsigned int _debug_guardpage_minorder
;
604 bool _debug_pagealloc_enabled __read_mostly
605 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
606 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
607 bool _debug_guardpage_enabled __read_mostly
;
609 static int __init
early_debug_pagealloc(char *buf
)
613 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
615 early_param("debug_pagealloc", early_debug_pagealloc
);
617 static bool need_debug_guardpage(void)
619 /* If we don't use debug_pagealloc, we don't need guard page */
620 if (!debug_pagealloc_enabled())
626 static void init_debug_guardpage(void)
628 if (!debug_pagealloc_enabled())
631 _debug_guardpage_enabled
= true;
634 struct page_ext_operations debug_guardpage_ops
= {
635 .need
= need_debug_guardpage
,
636 .init
= init_debug_guardpage
,
639 static int __init
debug_guardpage_minorder_setup(char *buf
)
643 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
644 pr_err("Bad debug_guardpage_minorder value\n");
647 _debug_guardpage_minorder
= res
;
648 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
651 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
653 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
654 unsigned int order
, int migratetype
)
656 struct page_ext
*page_ext
;
658 if (!debug_guardpage_enabled())
661 page_ext
= lookup_page_ext(page
);
662 if (unlikely(!page_ext
))
665 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
667 INIT_LIST_HEAD(&page
->lru
);
668 set_page_private(page
, order
);
669 /* Guard pages are not available for any usage */
670 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
673 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
674 unsigned int order
, int migratetype
)
676 struct page_ext
*page_ext
;
678 if (!debug_guardpage_enabled())
681 page_ext
= lookup_page_ext(page
);
682 if (unlikely(!page_ext
))
685 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
687 set_page_private(page
, 0);
688 if (!is_migrate_isolate(migratetype
))
689 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
692 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
693 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
694 unsigned int order
, int migratetype
) {}
695 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
696 unsigned int order
, int migratetype
) {}
699 static inline void set_page_order(struct page
*page
, unsigned int order
)
701 set_page_private(page
, order
);
702 __SetPageBuddy(page
);
705 static inline void rmv_page_order(struct page
*page
)
707 __ClearPageBuddy(page
);
708 set_page_private(page
, 0);
712 * This function checks whether a page is free && is the buddy
713 * we can do coalesce a page and its buddy if
714 * (a) the buddy is not in a hole &&
715 * (b) the buddy is in the buddy system &&
716 * (c) a page and its buddy have the same order &&
717 * (d) a page and its buddy are in the same zone.
719 * For recording whether a page is in the buddy system, we set ->_mapcount
720 * PAGE_BUDDY_MAPCOUNT_VALUE.
721 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
722 * serialized by zone->lock.
724 * For recording page's order, we use page_private(page).
726 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
729 if (!pfn_valid_within(page_to_pfn(buddy
)))
732 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
733 if (page_zone_id(page
) != page_zone_id(buddy
))
736 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
741 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
743 * zone check is done late to avoid uselessly
744 * calculating zone/node ids for pages that could
747 if (page_zone_id(page
) != page_zone_id(buddy
))
750 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
758 * Freeing function for a buddy system allocator.
760 * The concept of a buddy system is to maintain direct-mapped table
761 * (containing bit values) for memory blocks of various "orders".
762 * The bottom level table contains the map for the smallest allocatable
763 * units of memory (here, pages), and each level above it describes
764 * pairs of units from the levels below, hence, "buddies".
765 * At a high level, all that happens here is marking the table entry
766 * at the bottom level available, and propagating the changes upward
767 * as necessary, plus some accounting needed to play nicely with other
768 * parts of the VM system.
769 * At each level, we keep a list of pages, which are heads of continuous
770 * free pages of length of (1 << order) and marked with _mapcount
771 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
773 * So when we are allocating or freeing one, we can derive the state of the
774 * other. That is, if we allocate a small block, and both were
775 * free, the remainder of the region must be split into blocks.
776 * If a block is freed, and its buddy is also free, then this
777 * triggers coalescing into a block of larger size.
782 static inline void __free_one_page(struct page
*page
,
784 struct zone
*zone
, unsigned int order
,
787 unsigned long page_idx
;
788 unsigned long combined_idx
;
789 unsigned long uninitialized_var(buddy_idx
);
791 unsigned int max_order
;
793 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
795 VM_BUG_ON(!zone_is_initialized(zone
));
796 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
798 VM_BUG_ON(migratetype
== -1);
799 if (likely(!is_migrate_isolate(migratetype
)))
800 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
802 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
804 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
805 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
808 while (order
< max_order
- 1) {
809 buddy_idx
= __find_buddy_index(page_idx
, order
);
810 buddy
= page
+ (buddy_idx
- page_idx
);
811 if (!page_is_buddy(page
, buddy
, order
))
814 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
815 * merge with it and move up one order.
817 if (page_is_guard(buddy
)) {
818 clear_page_guard(zone
, buddy
, order
, migratetype
);
820 list_del(&buddy
->lru
);
821 zone
->free_area
[order
].nr_free
--;
822 rmv_page_order(buddy
);
824 combined_idx
= buddy_idx
& page_idx
;
825 page
= page
+ (combined_idx
- page_idx
);
826 page_idx
= combined_idx
;
829 if (max_order
< MAX_ORDER
) {
830 /* If we are here, it means order is >= pageblock_order.
831 * We want to prevent merge between freepages on isolate
832 * pageblock and normal pageblock. Without this, pageblock
833 * isolation could cause incorrect freepage or CMA accounting.
835 * We don't want to hit this code for the more frequent
838 if (unlikely(has_isolate_pageblock(zone
))) {
841 buddy_idx
= __find_buddy_index(page_idx
, order
);
842 buddy
= page
+ (buddy_idx
- page_idx
);
843 buddy_mt
= get_pageblock_migratetype(buddy
);
845 if (migratetype
!= buddy_mt
846 && (is_migrate_isolate(migratetype
) ||
847 is_migrate_isolate(buddy_mt
)))
851 goto continue_merging
;
855 set_page_order(page
, order
);
858 * If this is not the largest possible page, check if the buddy
859 * of the next-highest order is free. If it is, it's possible
860 * that pages are being freed that will coalesce soon. In case,
861 * that is happening, add the free page to the tail of the list
862 * so it's less likely to be used soon and more likely to be merged
863 * as a higher order page
865 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
866 struct page
*higher_page
, *higher_buddy
;
867 combined_idx
= buddy_idx
& page_idx
;
868 higher_page
= page
+ (combined_idx
- page_idx
);
869 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
870 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
871 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
872 list_add_tail(&page
->lru
,
873 &zone
->free_area
[order
].free_list
[migratetype
]);
878 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
880 zone
->free_area
[order
].nr_free
++;
884 * A bad page could be due to a number of fields. Instead of multiple branches,
885 * try and check multiple fields with one check. The caller must do a detailed
886 * check if necessary.
888 static inline bool page_expected_state(struct page
*page
,
889 unsigned long check_flags
)
891 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
894 if (unlikely((unsigned long)page
->mapping
|
895 page_ref_count(page
) |
897 (unsigned long)page
->mem_cgroup
|
899 (page
->flags
& check_flags
)))
905 static void free_pages_check_bad(struct page
*page
)
907 const char *bad_reason
;
908 unsigned long bad_flags
;
913 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
914 bad_reason
= "nonzero mapcount";
915 if (unlikely(page
->mapping
!= NULL
))
916 bad_reason
= "non-NULL mapping";
917 if (unlikely(page_ref_count(page
) != 0))
918 bad_reason
= "nonzero _refcount";
919 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
920 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
921 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
924 if (unlikely(page
->mem_cgroup
))
925 bad_reason
= "page still charged to cgroup";
927 bad_page(page
, bad_reason
, bad_flags
);
930 static inline int free_pages_check(struct page
*page
)
932 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
935 /* Something has gone sideways, find it */
936 free_pages_check_bad(page
);
940 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
945 * We rely page->lru.next never has bit 0 set, unless the page
946 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
948 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
950 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
954 switch (page
- head_page
) {
956 /* the first tail page: ->mapping is compound_mapcount() */
957 if (unlikely(compound_mapcount(page
))) {
958 bad_page(page
, "nonzero compound_mapcount", 0);
964 * the second tail page: ->mapping is
965 * page_deferred_list().next -- ignore value.
969 if (page
->mapping
!= TAIL_MAPPING
) {
970 bad_page(page
, "corrupted mapping in tail page", 0);
975 if (unlikely(!PageTail(page
))) {
976 bad_page(page
, "PageTail not set", 0);
979 if (unlikely(compound_head(page
) != head_page
)) {
980 bad_page(page
, "compound_head not consistent", 0);
985 page
->mapping
= NULL
;
986 clear_compound_head(page
);
990 static __always_inline
bool free_pages_prepare(struct page
*page
,
991 unsigned int order
, bool check_free
)
995 VM_BUG_ON_PAGE(PageTail(page
), page
);
997 trace_mm_page_free(page
, order
);
998 kmemcheck_free_shadow(page
, order
);
1001 * Check tail pages before head page information is cleared to
1002 * avoid checking PageCompound for order-0 pages.
1004 if (unlikely(order
)) {
1005 bool compound
= PageCompound(page
);
1008 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1011 ClearPageDoubleMap(page
);
1012 for (i
= 1; i
< (1 << order
); i
++) {
1014 bad
+= free_tail_pages_check(page
, page
+ i
);
1015 if (unlikely(free_pages_check(page
+ i
))) {
1019 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1022 if (PageMappingFlags(page
))
1023 page
->mapping
= NULL
;
1024 if (memcg_kmem_enabled() && PageKmemcg(page
)) {
1025 memcg_kmem_uncharge(page
, order
);
1026 __ClearPageKmemcg(page
);
1029 bad
+= free_pages_check(page
);
1033 page_cpupid_reset_last(page
);
1034 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1035 reset_page_owner(page
, order
);
1037 if (!PageHighMem(page
)) {
1038 debug_check_no_locks_freed(page_address(page
),
1039 PAGE_SIZE
<< order
);
1040 debug_check_no_obj_freed(page_address(page
),
1041 PAGE_SIZE
<< order
);
1043 arch_free_page(page
, order
);
1044 kernel_poison_pages(page
, 1 << order
, 0);
1045 kernel_map_pages(page
, 1 << order
, 0);
1046 kasan_free_pages(page
, order
);
1051 #ifdef CONFIG_DEBUG_VM
1052 static inline bool free_pcp_prepare(struct page
*page
)
1054 return free_pages_prepare(page
, 0, true);
1057 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1062 static bool free_pcp_prepare(struct page
*page
)
1064 return free_pages_prepare(page
, 0, false);
1067 static bool bulkfree_pcp_prepare(struct page
*page
)
1069 return free_pages_check(page
);
1071 #endif /* CONFIG_DEBUG_VM */
1074 * Frees a number of pages from the PCP lists
1075 * Assumes all pages on list are in same zone, and of same order.
1076 * count is the number of pages to free.
1078 * If the zone was previously in an "all pages pinned" state then look to
1079 * see if this freeing clears that state.
1081 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1082 * pinned" detection logic.
1084 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1085 struct per_cpu_pages
*pcp
)
1087 int migratetype
= 0;
1089 unsigned long nr_scanned
;
1090 bool isolated_pageblocks
;
1092 spin_lock(&zone
->lock
);
1093 isolated_pageblocks
= has_isolate_pageblock(zone
);
1094 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
1096 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
1100 struct list_head
*list
;
1103 * Remove pages from lists in a round-robin fashion. A
1104 * batch_free count is maintained that is incremented when an
1105 * empty list is encountered. This is so more pages are freed
1106 * off fuller lists instead of spinning excessively around empty
1111 if (++migratetype
== MIGRATE_PCPTYPES
)
1113 list
= &pcp
->lists
[migratetype
];
1114 } while (list_empty(list
));
1116 /* This is the only non-empty list. Free them all. */
1117 if (batch_free
== MIGRATE_PCPTYPES
)
1121 int mt
; /* migratetype of the to-be-freed page */
1123 page
= list_last_entry(list
, struct page
, lru
);
1124 /* must delete as __free_one_page list manipulates */
1125 list_del(&page
->lru
);
1127 mt
= get_pcppage_migratetype(page
);
1128 /* MIGRATE_ISOLATE page should not go to pcplists */
1129 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1130 /* Pageblock could have been isolated meanwhile */
1131 if (unlikely(isolated_pageblocks
))
1132 mt
= get_pageblock_migratetype(page
);
1134 if (bulkfree_pcp_prepare(page
))
1137 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1138 trace_mm_page_pcpu_drain(page
, 0, mt
);
1139 } while (--count
&& --batch_free
&& !list_empty(list
));
1141 spin_unlock(&zone
->lock
);
1144 static void free_one_page(struct zone
*zone
,
1145 struct page
*page
, unsigned long pfn
,
1149 unsigned long nr_scanned
;
1150 spin_lock(&zone
->lock
);
1151 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
1153 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
1155 if (unlikely(has_isolate_pageblock(zone
) ||
1156 is_migrate_isolate(migratetype
))) {
1157 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1159 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1160 spin_unlock(&zone
->lock
);
1163 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1164 unsigned long zone
, int nid
)
1166 set_page_links(page
, zone
, nid
, pfn
);
1167 init_page_count(page
);
1168 page_mapcount_reset(page
);
1169 page_cpupid_reset_last(page
);
1171 INIT_LIST_HEAD(&page
->lru
);
1172 #ifdef WANT_PAGE_VIRTUAL
1173 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1174 if (!is_highmem_idx(zone
))
1175 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1179 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1182 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1185 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1186 static void init_reserved_page(unsigned long pfn
)
1191 if (!early_page_uninitialised(pfn
))
1194 nid
= early_pfn_to_nid(pfn
);
1195 pgdat
= NODE_DATA(nid
);
1197 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1198 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1200 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1203 __init_single_pfn(pfn
, zid
, nid
);
1206 static inline void init_reserved_page(unsigned long pfn
)
1209 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1212 * Initialised pages do not have PageReserved set. This function is
1213 * called for each range allocated by the bootmem allocator and
1214 * marks the pages PageReserved. The remaining valid pages are later
1215 * sent to the buddy page allocator.
1217 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1219 unsigned long start_pfn
= PFN_DOWN(start
);
1220 unsigned long end_pfn
= PFN_UP(end
);
1222 for (; start_pfn
< end_pfn
; start_pfn
++) {
1223 if (pfn_valid(start_pfn
)) {
1224 struct page
*page
= pfn_to_page(start_pfn
);
1226 init_reserved_page(start_pfn
);
1228 /* Avoid false-positive PageTail() */
1229 INIT_LIST_HEAD(&page
->lru
);
1231 SetPageReserved(page
);
1236 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1238 unsigned long flags
;
1240 unsigned long pfn
= page_to_pfn(page
);
1242 if (!free_pages_prepare(page
, order
, true))
1245 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1246 local_irq_save(flags
);
1247 __count_vm_events(PGFREE
, 1 << order
);
1248 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1249 local_irq_restore(flags
);
1252 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1254 unsigned int nr_pages
= 1 << order
;
1255 struct page
*p
= page
;
1259 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1261 __ClearPageReserved(p
);
1262 set_page_count(p
, 0);
1264 __ClearPageReserved(p
);
1265 set_page_count(p
, 0);
1267 page_zone(page
)->managed_pages
+= nr_pages
;
1268 set_page_refcounted(page
);
1269 __free_pages(page
, order
);
1272 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1273 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1275 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1277 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1279 static DEFINE_SPINLOCK(early_pfn_lock
);
1282 spin_lock(&early_pfn_lock
);
1283 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1285 nid
= first_online_node
;
1286 spin_unlock(&early_pfn_lock
);
1292 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1293 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1294 struct mminit_pfnnid_cache
*state
)
1298 nid
= __early_pfn_to_nid(pfn
, state
);
1299 if (nid
>= 0 && nid
!= node
)
1304 /* Only safe to use early in boot when initialisation is single-threaded */
1305 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1307 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1312 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1316 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1317 struct mminit_pfnnid_cache
*state
)
1324 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1327 if (early_page_uninitialised(pfn
))
1329 return __free_pages_boot_core(page
, order
);
1333 * Check that the whole (or subset of) a pageblock given by the interval of
1334 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1335 * with the migration of free compaction scanner. The scanners then need to
1336 * use only pfn_valid_within() check for arches that allow holes within
1339 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1341 * It's possible on some configurations to have a setup like node0 node1 node0
1342 * i.e. it's possible that all pages within a zones range of pages do not
1343 * belong to a single zone. We assume that a border between node0 and node1
1344 * can occur within a single pageblock, but not a node0 node1 node0
1345 * interleaving within a single pageblock. It is therefore sufficient to check
1346 * the first and last page of a pageblock and avoid checking each individual
1347 * page in a pageblock.
1349 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1350 unsigned long end_pfn
, struct zone
*zone
)
1352 struct page
*start_page
;
1353 struct page
*end_page
;
1355 /* end_pfn is one past the range we are checking */
1358 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1361 start_page
= pfn_to_page(start_pfn
);
1363 if (page_zone(start_page
) != zone
)
1366 end_page
= pfn_to_page(end_pfn
);
1368 /* This gives a shorter code than deriving page_zone(end_page) */
1369 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1375 void set_zone_contiguous(struct zone
*zone
)
1377 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1378 unsigned long block_end_pfn
;
1380 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1381 for (; block_start_pfn
< zone_end_pfn(zone
);
1382 block_start_pfn
= block_end_pfn
,
1383 block_end_pfn
+= pageblock_nr_pages
) {
1385 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1387 if (!__pageblock_pfn_to_page(block_start_pfn
,
1388 block_end_pfn
, zone
))
1392 /* We confirm that there is no hole */
1393 zone
->contiguous
= true;
1396 void clear_zone_contiguous(struct zone
*zone
)
1398 zone
->contiguous
= false;
1401 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1402 static void __init
deferred_free_range(struct page
*page
,
1403 unsigned long pfn
, int nr_pages
)
1410 /* Free a large naturally-aligned chunk if possible */
1411 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1412 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1413 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1414 __free_pages_boot_core(page
, MAX_ORDER
-1);
1418 for (i
= 0; i
< nr_pages
; i
++, page
++)
1419 __free_pages_boot_core(page
, 0);
1422 /* Completion tracking for deferred_init_memmap() threads */
1423 static atomic_t pgdat_init_n_undone __initdata
;
1424 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1426 static inline void __init
pgdat_init_report_one_done(void)
1428 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1429 complete(&pgdat_init_all_done_comp
);
1432 /* Initialise remaining memory on a node */
1433 static int __init
deferred_init_memmap(void *data
)
1435 pg_data_t
*pgdat
= data
;
1436 int nid
= pgdat
->node_id
;
1437 struct mminit_pfnnid_cache nid_init_state
= { };
1438 unsigned long start
= jiffies
;
1439 unsigned long nr_pages
= 0;
1440 unsigned long walk_start
, walk_end
;
1443 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1444 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1446 if (first_init_pfn
== ULONG_MAX
) {
1447 pgdat_init_report_one_done();
1451 /* Bind memory initialisation thread to a local node if possible */
1452 if (!cpumask_empty(cpumask
))
1453 set_cpus_allowed_ptr(current
, cpumask
);
1455 /* Sanity check boundaries */
1456 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1457 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1458 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1460 /* Only the highest zone is deferred so find it */
1461 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1462 zone
= pgdat
->node_zones
+ zid
;
1463 if (first_init_pfn
< zone_end_pfn(zone
))
1467 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1468 unsigned long pfn
, end_pfn
;
1469 struct page
*page
= NULL
;
1470 struct page
*free_base_page
= NULL
;
1471 unsigned long free_base_pfn
= 0;
1474 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1475 pfn
= first_init_pfn
;
1476 if (pfn
< walk_start
)
1478 if (pfn
< zone
->zone_start_pfn
)
1479 pfn
= zone
->zone_start_pfn
;
1481 for (; pfn
< end_pfn
; pfn
++) {
1482 if (!pfn_valid_within(pfn
))
1486 * Ensure pfn_valid is checked every
1487 * MAX_ORDER_NR_PAGES for memory holes
1489 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1490 if (!pfn_valid(pfn
)) {
1496 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1501 /* Minimise pfn page lookups and scheduler checks */
1502 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1505 nr_pages
+= nr_to_free
;
1506 deferred_free_range(free_base_page
,
1507 free_base_pfn
, nr_to_free
);
1508 free_base_page
= NULL
;
1509 free_base_pfn
= nr_to_free
= 0;
1511 page
= pfn_to_page(pfn
);
1516 VM_BUG_ON(page_zone(page
) != zone
);
1520 __init_single_page(page
, pfn
, zid
, nid
);
1521 if (!free_base_page
) {
1522 free_base_page
= page
;
1523 free_base_pfn
= pfn
;
1528 /* Where possible, batch up pages for a single free */
1531 /* Free the current block of pages to allocator */
1532 nr_pages
+= nr_to_free
;
1533 deferred_free_range(free_base_page
, free_base_pfn
,
1535 free_base_page
= NULL
;
1536 free_base_pfn
= nr_to_free
= 0;
1539 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1542 /* Sanity check that the next zone really is unpopulated */
1543 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1545 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1546 jiffies_to_msecs(jiffies
- start
));
1548 pgdat_init_report_one_done();
1551 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1553 void __init
page_alloc_init_late(void)
1557 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1560 /* There will be num_node_state(N_MEMORY) threads */
1561 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1562 for_each_node_state(nid
, N_MEMORY
) {
1563 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1566 /* Block until all are initialised */
1567 wait_for_completion(&pgdat_init_all_done_comp
);
1569 /* Reinit limits that are based on free pages after the kernel is up */
1570 files_maxfiles_init();
1573 for_each_populated_zone(zone
)
1574 set_zone_contiguous(zone
);
1578 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1579 void __init
init_cma_reserved_pageblock(struct page
*page
)
1581 unsigned i
= pageblock_nr_pages
;
1582 struct page
*p
= page
;
1585 __ClearPageReserved(p
);
1586 set_page_count(p
, 0);
1589 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1591 if (pageblock_order
>= MAX_ORDER
) {
1592 i
= pageblock_nr_pages
;
1595 set_page_refcounted(p
);
1596 __free_pages(p
, MAX_ORDER
- 1);
1597 p
+= MAX_ORDER_NR_PAGES
;
1598 } while (i
-= MAX_ORDER_NR_PAGES
);
1600 set_page_refcounted(page
);
1601 __free_pages(page
, pageblock_order
);
1604 adjust_managed_page_count(page
, pageblock_nr_pages
);
1609 * The order of subdivision here is critical for the IO subsystem.
1610 * Please do not alter this order without good reasons and regression
1611 * testing. Specifically, as large blocks of memory are subdivided,
1612 * the order in which smaller blocks are delivered depends on the order
1613 * they're subdivided in this function. This is the primary factor
1614 * influencing the order in which pages are delivered to the IO
1615 * subsystem according to empirical testing, and this is also justified
1616 * by considering the behavior of a buddy system containing a single
1617 * large block of memory acted on by a series of small allocations.
1618 * This behavior is a critical factor in sglist merging's success.
1622 static inline void expand(struct zone
*zone
, struct page
*page
,
1623 int low
, int high
, struct free_area
*area
,
1626 unsigned long size
= 1 << high
;
1628 while (high
> low
) {
1632 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1634 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1635 debug_guardpage_enabled() &&
1636 high
< debug_guardpage_minorder()) {
1638 * Mark as guard pages (or page), that will allow to
1639 * merge back to allocator when buddy will be freed.
1640 * Corresponding page table entries will not be touched,
1641 * pages will stay not present in virtual address space
1643 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1646 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1648 set_page_order(&page
[size
], high
);
1652 static void check_new_page_bad(struct page
*page
)
1654 const char *bad_reason
= NULL
;
1655 unsigned long bad_flags
= 0;
1657 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1658 bad_reason
= "nonzero mapcount";
1659 if (unlikely(page
->mapping
!= NULL
))
1660 bad_reason
= "non-NULL mapping";
1661 if (unlikely(page_ref_count(page
) != 0))
1662 bad_reason
= "nonzero _count";
1663 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1664 bad_reason
= "HWPoisoned (hardware-corrupted)";
1665 bad_flags
= __PG_HWPOISON
;
1666 /* Don't complain about hwpoisoned pages */
1667 page_mapcount_reset(page
); /* remove PageBuddy */
1670 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1671 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1672 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1675 if (unlikely(page
->mem_cgroup
))
1676 bad_reason
= "page still charged to cgroup";
1678 bad_page(page
, bad_reason
, bad_flags
);
1682 * This page is about to be returned from the page allocator
1684 static inline int check_new_page(struct page
*page
)
1686 if (likely(page_expected_state(page
,
1687 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1690 check_new_page_bad(page
);
1694 static inline bool free_pages_prezeroed(bool poisoned
)
1696 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1697 page_poisoning_enabled() && poisoned
;
1700 #ifdef CONFIG_DEBUG_VM
1701 static bool check_pcp_refill(struct page
*page
)
1706 static bool check_new_pcp(struct page
*page
)
1708 return check_new_page(page
);
1711 static bool check_pcp_refill(struct page
*page
)
1713 return check_new_page(page
);
1715 static bool check_new_pcp(struct page
*page
)
1719 #endif /* CONFIG_DEBUG_VM */
1721 static bool check_new_pages(struct page
*page
, unsigned int order
)
1724 for (i
= 0; i
< (1 << order
); i
++) {
1725 struct page
*p
= page
+ i
;
1727 if (unlikely(check_new_page(p
)))
1734 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1737 set_page_private(page
, 0);
1738 set_page_refcounted(page
);
1740 arch_alloc_page(page
, order
);
1741 kernel_map_pages(page
, 1 << order
, 1);
1742 kernel_poison_pages(page
, 1 << order
, 1);
1743 kasan_alloc_pages(page
, order
);
1744 set_page_owner(page
, order
, gfp_flags
);
1747 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1748 unsigned int alloc_flags
)
1751 bool poisoned
= true;
1753 for (i
= 0; i
< (1 << order
); i
++) {
1754 struct page
*p
= page
+ i
;
1756 poisoned
&= page_is_poisoned(p
);
1759 post_alloc_hook(page
, order
, gfp_flags
);
1761 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1762 for (i
= 0; i
< (1 << order
); i
++)
1763 clear_highpage(page
+ i
);
1765 if (order
&& (gfp_flags
& __GFP_COMP
))
1766 prep_compound_page(page
, order
);
1769 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1770 * allocate the page. The expectation is that the caller is taking
1771 * steps that will free more memory. The caller should avoid the page
1772 * being used for !PFMEMALLOC purposes.
1774 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1775 set_page_pfmemalloc(page
);
1777 clear_page_pfmemalloc(page
);
1781 * Go through the free lists for the given migratetype and remove
1782 * the smallest available page from the freelists
1785 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1788 unsigned int current_order
;
1789 struct free_area
*area
;
1792 /* Find a page of the appropriate size in the preferred list */
1793 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1794 area
= &(zone
->free_area
[current_order
]);
1795 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1799 list_del(&page
->lru
);
1800 rmv_page_order(page
);
1802 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1803 set_pcppage_migratetype(page
, migratetype
);
1812 * This array describes the order lists are fallen back to when
1813 * the free lists for the desirable migrate type are depleted
1815 static int fallbacks
[MIGRATE_TYPES
][4] = {
1816 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1817 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1818 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1820 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1822 #ifdef CONFIG_MEMORY_ISOLATION
1823 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1828 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1831 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1834 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1835 unsigned int order
) { return NULL
; }
1839 * Move the free pages in a range to the free lists of the requested type.
1840 * Note that start_page and end_pages are not aligned on a pageblock
1841 * boundary. If alignment is required, use move_freepages_block()
1843 int move_freepages(struct zone
*zone
,
1844 struct page
*start_page
, struct page
*end_page
,
1849 int pages_moved
= 0;
1851 #ifndef CONFIG_HOLES_IN_ZONE
1853 * page_zone is not safe to call in this context when
1854 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1855 * anyway as we check zone boundaries in move_freepages_block().
1856 * Remove at a later date when no bug reports exist related to
1857 * grouping pages by mobility
1859 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1862 for (page
= start_page
; page
<= end_page
;) {
1863 /* Make sure we are not inadvertently changing nodes */
1864 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1866 if (!pfn_valid_within(page_to_pfn(page
))) {
1871 if (!PageBuddy(page
)) {
1876 order
= page_order(page
);
1877 list_move(&page
->lru
,
1878 &zone
->free_area
[order
].free_list
[migratetype
]);
1880 pages_moved
+= 1 << order
;
1886 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1889 unsigned long start_pfn
, end_pfn
;
1890 struct page
*start_page
, *end_page
;
1892 start_pfn
= page_to_pfn(page
);
1893 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1894 start_page
= pfn_to_page(start_pfn
);
1895 end_page
= start_page
+ pageblock_nr_pages
- 1;
1896 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1898 /* Do not cross zone boundaries */
1899 if (!zone_spans_pfn(zone
, start_pfn
))
1901 if (!zone_spans_pfn(zone
, end_pfn
))
1904 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1907 static void change_pageblock_range(struct page
*pageblock_page
,
1908 int start_order
, int migratetype
)
1910 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1912 while (nr_pageblocks
--) {
1913 set_pageblock_migratetype(pageblock_page
, migratetype
);
1914 pageblock_page
+= pageblock_nr_pages
;
1919 * When we are falling back to another migratetype during allocation, try to
1920 * steal extra free pages from the same pageblocks to satisfy further
1921 * allocations, instead of polluting multiple pageblocks.
1923 * If we are stealing a relatively large buddy page, it is likely there will
1924 * be more free pages in the pageblock, so try to steal them all. For
1925 * reclaimable and unmovable allocations, we steal regardless of page size,
1926 * as fragmentation caused by those allocations polluting movable pageblocks
1927 * is worse than movable allocations stealing from unmovable and reclaimable
1930 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1933 * Leaving this order check is intended, although there is
1934 * relaxed order check in next check. The reason is that
1935 * we can actually steal whole pageblock if this condition met,
1936 * but, below check doesn't guarantee it and that is just heuristic
1937 * so could be changed anytime.
1939 if (order
>= pageblock_order
)
1942 if (order
>= pageblock_order
/ 2 ||
1943 start_mt
== MIGRATE_RECLAIMABLE
||
1944 start_mt
== MIGRATE_UNMOVABLE
||
1945 page_group_by_mobility_disabled
)
1952 * This function implements actual steal behaviour. If order is large enough,
1953 * we can steal whole pageblock. If not, we first move freepages in this
1954 * pageblock and check whether half of pages are moved or not. If half of
1955 * pages are moved, we can change migratetype of pageblock and permanently
1956 * use it's pages as requested migratetype in the future.
1958 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1961 unsigned int current_order
= page_order(page
);
1964 /* Take ownership for orders >= pageblock_order */
1965 if (current_order
>= pageblock_order
) {
1966 change_pageblock_range(page
, current_order
, start_type
);
1970 pages
= move_freepages_block(zone
, page
, start_type
);
1972 /* Claim the whole block if over half of it is free */
1973 if (pages
>= (1 << (pageblock_order
-1)) ||
1974 page_group_by_mobility_disabled
)
1975 set_pageblock_migratetype(page
, start_type
);
1979 * Check whether there is a suitable fallback freepage with requested order.
1980 * If only_stealable is true, this function returns fallback_mt only if
1981 * we can steal other freepages all together. This would help to reduce
1982 * fragmentation due to mixed migratetype pages in one pageblock.
1984 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1985 int migratetype
, bool only_stealable
, bool *can_steal
)
1990 if (area
->nr_free
== 0)
1995 fallback_mt
= fallbacks
[migratetype
][i
];
1996 if (fallback_mt
== MIGRATE_TYPES
)
1999 if (list_empty(&area
->free_list
[fallback_mt
]))
2002 if (can_steal_fallback(order
, migratetype
))
2005 if (!only_stealable
)
2016 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2017 * there are no empty page blocks that contain a page with a suitable order
2019 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2020 unsigned int alloc_order
)
2023 unsigned long max_managed
, flags
;
2026 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2027 * Check is race-prone but harmless.
2029 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2030 if (zone
->nr_reserved_highatomic
>= max_managed
)
2033 spin_lock_irqsave(&zone
->lock
, flags
);
2035 /* Recheck the nr_reserved_highatomic limit under the lock */
2036 if (zone
->nr_reserved_highatomic
>= max_managed
)
2040 mt
= get_pageblock_migratetype(page
);
2041 if (mt
!= MIGRATE_HIGHATOMIC
&&
2042 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
2043 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2044 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2045 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
2049 spin_unlock_irqrestore(&zone
->lock
, flags
);
2053 * Used when an allocation is about to fail under memory pressure. This
2054 * potentially hurts the reliability of high-order allocations when under
2055 * intense memory pressure but failed atomic allocations should be easier
2056 * to recover from than an OOM.
2058 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
2060 struct zonelist
*zonelist
= ac
->zonelist
;
2061 unsigned long flags
;
2067 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2069 /* Preserve at least one pageblock */
2070 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
2073 spin_lock_irqsave(&zone
->lock
, flags
);
2074 for (order
= 0; order
< MAX_ORDER
; order
++) {
2075 struct free_area
*area
= &(zone
->free_area
[order
]);
2077 page
= list_first_entry_or_null(
2078 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2084 * It should never happen but changes to locking could
2085 * inadvertently allow a per-cpu drain to add pages
2086 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2087 * and watch for underflows.
2089 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
2090 zone
->nr_reserved_highatomic
);
2093 * Convert to ac->migratetype and avoid the normal
2094 * pageblock stealing heuristics. Minimally, the caller
2095 * is doing the work and needs the pages. More
2096 * importantly, if the block was always converted to
2097 * MIGRATE_UNMOVABLE or another type then the number
2098 * of pageblocks that cannot be completely freed
2101 set_pageblock_migratetype(page
, ac
->migratetype
);
2102 move_freepages_block(zone
, page
, ac
->migratetype
);
2103 spin_unlock_irqrestore(&zone
->lock
, flags
);
2106 spin_unlock_irqrestore(&zone
->lock
, flags
);
2110 /* Remove an element from the buddy allocator from the fallback list */
2111 static inline struct page
*
2112 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
2114 struct free_area
*area
;
2115 unsigned int current_order
;
2120 /* Find the largest possible block of pages in the other list */
2121 for (current_order
= MAX_ORDER
-1;
2122 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
2124 area
= &(zone
->free_area
[current_order
]);
2125 fallback_mt
= find_suitable_fallback(area
, current_order
,
2126 start_migratetype
, false, &can_steal
);
2127 if (fallback_mt
== -1)
2130 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2133 steal_suitable_fallback(zone
, page
, start_migratetype
);
2135 /* Remove the page from the freelists */
2137 list_del(&page
->lru
);
2138 rmv_page_order(page
);
2140 expand(zone
, page
, order
, current_order
, area
,
2143 * The pcppage_migratetype may differ from pageblock's
2144 * migratetype depending on the decisions in
2145 * find_suitable_fallback(). This is OK as long as it does not
2146 * differ for MIGRATE_CMA pageblocks. Those can be used as
2147 * fallback only via special __rmqueue_cma_fallback() function
2149 set_pcppage_migratetype(page
, start_migratetype
);
2151 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2152 start_migratetype
, fallback_mt
);
2161 * Do the hard work of removing an element from the buddy allocator.
2162 * Call me with the zone->lock already held.
2164 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2169 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2170 if (unlikely(!page
)) {
2171 if (migratetype
== MIGRATE_MOVABLE
)
2172 page
= __rmqueue_cma_fallback(zone
, order
);
2175 page
= __rmqueue_fallback(zone
, order
, migratetype
);
2178 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2183 * Obtain a specified number of elements from the buddy allocator, all under
2184 * a single hold of the lock, for efficiency. Add them to the supplied list.
2185 * Returns the number of new pages which were placed at *list.
2187 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2188 unsigned long count
, struct list_head
*list
,
2189 int migratetype
, bool cold
)
2193 spin_lock(&zone
->lock
);
2194 for (i
= 0; i
< count
; ++i
) {
2195 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2196 if (unlikely(page
== NULL
))
2199 if (unlikely(check_pcp_refill(page
)))
2203 * Split buddy pages returned by expand() are received here
2204 * in physical page order. The page is added to the callers and
2205 * list and the list head then moves forward. From the callers
2206 * perspective, the linked list is ordered by page number in
2207 * some conditions. This is useful for IO devices that can
2208 * merge IO requests if the physical pages are ordered
2212 list_add(&page
->lru
, list
);
2214 list_add_tail(&page
->lru
, list
);
2216 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2217 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2220 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2221 spin_unlock(&zone
->lock
);
2227 * Called from the vmstat counter updater to drain pagesets of this
2228 * currently executing processor on remote nodes after they have
2231 * Note that this function must be called with the thread pinned to
2232 * a single processor.
2234 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2236 unsigned long flags
;
2237 int to_drain
, batch
;
2239 local_irq_save(flags
);
2240 batch
= READ_ONCE(pcp
->batch
);
2241 to_drain
= min(pcp
->count
, batch
);
2243 free_pcppages_bulk(zone
, to_drain
, pcp
);
2244 pcp
->count
-= to_drain
;
2246 local_irq_restore(flags
);
2251 * Drain pcplists of the indicated processor and zone.
2253 * The processor must either be the current processor and the
2254 * thread pinned to the current processor or a processor that
2257 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2259 unsigned long flags
;
2260 struct per_cpu_pageset
*pset
;
2261 struct per_cpu_pages
*pcp
;
2263 local_irq_save(flags
);
2264 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2268 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2271 local_irq_restore(flags
);
2275 * Drain pcplists of all zones on the indicated processor.
2277 * The processor must either be the current processor and the
2278 * thread pinned to the current processor or a processor that
2281 static void drain_pages(unsigned int cpu
)
2285 for_each_populated_zone(zone
) {
2286 drain_pages_zone(cpu
, zone
);
2291 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2293 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2294 * the single zone's pages.
2296 void drain_local_pages(struct zone
*zone
)
2298 int cpu
= smp_processor_id();
2301 drain_pages_zone(cpu
, zone
);
2307 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2309 * When zone parameter is non-NULL, spill just the single zone's pages.
2311 * Note that this code is protected against sending an IPI to an offline
2312 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2313 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2314 * nothing keeps CPUs from showing up after we populated the cpumask and
2315 * before the call to on_each_cpu_mask().
2317 void drain_all_pages(struct zone
*zone
)
2322 * Allocate in the BSS so we wont require allocation in
2323 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2325 static cpumask_t cpus_with_pcps
;
2328 * We don't care about racing with CPU hotplug event
2329 * as offline notification will cause the notified
2330 * cpu to drain that CPU pcps and on_each_cpu_mask
2331 * disables preemption as part of its processing
2333 for_each_online_cpu(cpu
) {
2334 struct per_cpu_pageset
*pcp
;
2336 bool has_pcps
= false;
2339 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2343 for_each_populated_zone(z
) {
2344 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2345 if (pcp
->pcp
.count
) {
2353 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2355 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2357 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2361 #ifdef CONFIG_HIBERNATION
2363 void mark_free_pages(struct zone
*zone
)
2365 unsigned long pfn
, max_zone_pfn
;
2366 unsigned long flags
;
2367 unsigned int order
, t
;
2370 if (zone_is_empty(zone
))
2373 spin_lock_irqsave(&zone
->lock
, flags
);
2375 max_zone_pfn
= zone_end_pfn(zone
);
2376 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2377 if (pfn_valid(pfn
)) {
2378 page
= pfn_to_page(pfn
);
2380 if (page_zone(page
) != zone
)
2383 if (!swsusp_page_is_forbidden(page
))
2384 swsusp_unset_page_free(page
);
2387 for_each_migratetype_order(order
, t
) {
2388 list_for_each_entry(page
,
2389 &zone
->free_area
[order
].free_list
[t
], lru
) {
2392 pfn
= page_to_pfn(page
);
2393 for (i
= 0; i
< (1UL << order
); i
++)
2394 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2397 spin_unlock_irqrestore(&zone
->lock
, flags
);
2399 #endif /* CONFIG_PM */
2402 * Free a 0-order page
2403 * cold == true ? free a cold page : free a hot page
2405 void free_hot_cold_page(struct page
*page
, bool cold
)
2407 struct zone
*zone
= page_zone(page
);
2408 struct per_cpu_pages
*pcp
;
2409 unsigned long flags
;
2410 unsigned long pfn
= page_to_pfn(page
);
2413 if (!free_pcp_prepare(page
))
2416 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2417 set_pcppage_migratetype(page
, migratetype
);
2418 local_irq_save(flags
);
2419 __count_vm_event(PGFREE
);
2422 * We only track unmovable, reclaimable and movable on pcp lists.
2423 * Free ISOLATE pages back to the allocator because they are being
2424 * offlined but treat RESERVE as movable pages so we can get those
2425 * areas back if necessary. Otherwise, we may have to free
2426 * excessively into the page allocator
2428 if (migratetype
>= MIGRATE_PCPTYPES
) {
2429 if (unlikely(is_migrate_isolate(migratetype
))) {
2430 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2433 migratetype
= MIGRATE_MOVABLE
;
2436 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2438 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2440 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2442 if (pcp
->count
>= pcp
->high
) {
2443 unsigned long batch
= READ_ONCE(pcp
->batch
);
2444 free_pcppages_bulk(zone
, batch
, pcp
);
2445 pcp
->count
-= batch
;
2449 local_irq_restore(flags
);
2453 * Free a list of 0-order pages
2455 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2457 struct page
*page
, *next
;
2459 list_for_each_entry_safe(page
, next
, list
, lru
) {
2460 trace_mm_page_free_batched(page
, cold
);
2461 free_hot_cold_page(page
, cold
);
2466 * split_page takes a non-compound higher-order page, and splits it into
2467 * n (1<<order) sub-pages: page[0..n]
2468 * Each sub-page must be freed individually.
2470 * Note: this is probably too low level an operation for use in drivers.
2471 * Please consult with lkml before using this in your driver.
2473 void split_page(struct page
*page
, unsigned int order
)
2477 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2478 VM_BUG_ON_PAGE(!page_count(page
), page
);
2480 #ifdef CONFIG_KMEMCHECK
2482 * Split shadow pages too, because free(page[0]) would
2483 * otherwise free the whole shadow.
2485 if (kmemcheck_page_is_tracked(page
))
2486 split_page(virt_to_page(page
[0].shadow
), order
);
2489 for (i
= 1; i
< (1 << order
); i
++)
2490 set_page_refcounted(page
+ i
);
2491 split_page_owner(page
, order
);
2493 EXPORT_SYMBOL_GPL(split_page
);
2495 int __isolate_free_page(struct page
*page
, unsigned int order
)
2497 unsigned long watermark
;
2501 BUG_ON(!PageBuddy(page
));
2503 zone
= page_zone(page
);
2504 mt
= get_pageblock_migratetype(page
);
2506 if (!is_migrate_isolate(mt
)) {
2507 /* Obey watermarks as if the page was being allocated */
2508 watermark
= low_wmark_pages(zone
) + (1 << order
);
2509 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2512 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2515 /* Remove page from free list */
2516 list_del(&page
->lru
);
2517 zone
->free_area
[order
].nr_free
--;
2518 rmv_page_order(page
);
2520 /* Set the pageblock if the isolated page is at least a pageblock */
2521 if (order
>= pageblock_order
- 1) {
2522 struct page
*endpage
= page
+ (1 << order
) - 1;
2523 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2524 int mt
= get_pageblock_migratetype(page
);
2525 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2526 set_pageblock_migratetype(page
,
2532 return 1UL << order
;
2536 * Update NUMA hit/miss statistics
2538 * Must be called with interrupts disabled.
2540 * When __GFP_OTHER_NODE is set assume the node of the preferred
2541 * zone is the local node. This is useful for daemons who allocate
2542 * memory on behalf of other processes.
2544 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
,
2548 int local_nid
= numa_node_id();
2549 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2551 if (unlikely(flags
& __GFP_OTHER_NODE
)) {
2552 local_stat
= NUMA_OTHER
;
2553 local_nid
= preferred_zone
->node
;
2556 if (z
->node
== local_nid
) {
2557 __inc_zone_state(z
, NUMA_HIT
);
2558 __inc_zone_state(z
, local_stat
);
2560 __inc_zone_state(z
, NUMA_MISS
);
2561 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2567 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2570 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2571 struct zone
*zone
, unsigned int order
,
2572 gfp_t gfp_flags
, unsigned int alloc_flags
,
2575 unsigned long flags
;
2577 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2579 if (likely(order
== 0)) {
2580 struct per_cpu_pages
*pcp
;
2581 struct list_head
*list
;
2583 local_irq_save(flags
);
2585 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2586 list
= &pcp
->lists
[migratetype
];
2587 if (list_empty(list
)) {
2588 pcp
->count
+= rmqueue_bulk(zone
, 0,
2591 if (unlikely(list_empty(list
)))
2596 page
= list_last_entry(list
, struct page
, lru
);
2598 page
= list_first_entry(list
, struct page
, lru
);
2600 __dec_zone_state(zone
, NR_ALLOC_BATCH
);
2601 list_del(&page
->lru
);
2604 } while (check_new_pcp(page
));
2607 * We most definitely don't want callers attempting to
2608 * allocate greater than order-1 page units with __GFP_NOFAIL.
2610 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2611 spin_lock_irqsave(&zone
->lock
, flags
);
2615 if (alloc_flags
& ALLOC_HARDER
) {
2616 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2618 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2621 page
= __rmqueue(zone
, order
, migratetype
);
2622 } while (page
&& check_new_pages(page
, order
));
2623 spin_unlock(&zone
->lock
);
2626 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2627 __mod_zone_freepage_state(zone
, -(1 << order
),
2628 get_pcppage_migratetype(page
));
2631 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2632 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2633 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2635 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2636 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2637 local_irq_restore(flags
);
2639 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2643 local_irq_restore(flags
);
2647 #ifdef CONFIG_FAIL_PAGE_ALLOC
2650 struct fault_attr attr
;
2652 bool ignore_gfp_highmem
;
2653 bool ignore_gfp_reclaim
;
2655 } fail_page_alloc
= {
2656 .attr
= FAULT_ATTR_INITIALIZER
,
2657 .ignore_gfp_reclaim
= true,
2658 .ignore_gfp_highmem
= true,
2662 static int __init
setup_fail_page_alloc(char *str
)
2664 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2666 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2668 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2670 if (order
< fail_page_alloc
.min_order
)
2672 if (gfp_mask
& __GFP_NOFAIL
)
2674 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2676 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2677 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2680 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2683 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2685 static int __init
fail_page_alloc_debugfs(void)
2687 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2690 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2691 &fail_page_alloc
.attr
);
2693 return PTR_ERR(dir
);
2695 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2696 &fail_page_alloc
.ignore_gfp_reclaim
))
2698 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2699 &fail_page_alloc
.ignore_gfp_highmem
))
2701 if (!debugfs_create_u32("min-order", mode
, dir
,
2702 &fail_page_alloc
.min_order
))
2707 debugfs_remove_recursive(dir
);
2712 late_initcall(fail_page_alloc_debugfs
);
2714 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2716 #else /* CONFIG_FAIL_PAGE_ALLOC */
2718 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2723 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2726 * Return true if free base pages are above 'mark'. For high-order checks it
2727 * will return true of the order-0 watermark is reached and there is at least
2728 * one free page of a suitable size. Checking now avoids taking the zone lock
2729 * to check in the allocation paths if no pages are free.
2731 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2732 int classzone_idx
, unsigned int alloc_flags
,
2737 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2739 /* free_pages may go negative - that's OK */
2740 free_pages
-= (1 << order
) - 1;
2742 if (alloc_flags
& ALLOC_HIGH
)
2746 * If the caller does not have rights to ALLOC_HARDER then subtract
2747 * the high-atomic reserves. This will over-estimate the size of the
2748 * atomic reserve but it avoids a search.
2750 if (likely(!alloc_harder
))
2751 free_pages
-= z
->nr_reserved_highatomic
;
2756 /* If allocation can't use CMA areas don't use free CMA pages */
2757 if (!(alloc_flags
& ALLOC_CMA
))
2758 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2762 * Check watermarks for an order-0 allocation request. If these
2763 * are not met, then a high-order request also cannot go ahead
2764 * even if a suitable page happened to be free.
2766 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2769 /* If this is an order-0 request then the watermark is fine */
2773 /* For a high-order request, check at least one suitable page is free */
2774 for (o
= order
; o
< MAX_ORDER
; o
++) {
2775 struct free_area
*area
= &z
->free_area
[o
];
2784 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2785 if (!list_empty(&area
->free_list
[mt
]))
2790 if ((alloc_flags
& ALLOC_CMA
) &&
2791 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2799 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2800 int classzone_idx
, unsigned int alloc_flags
)
2802 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2803 zone_page_state(z
, NR_FREE_PAGES
));
2806 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
2807 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
2809 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2813 /* If allocation can't use CMA areas don't use free CMA pages */
2814 if (!(alloc_flags
& ALLOC_CMA
))
2815 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2819 * Fast check for order-0 only. If this fails then the reserves
2820 * need to be calculated. There is a corner case where the check
2821 * passes but only the high-order atomic reserve are free. If
2822 * the caller is !atomic then it'll uselessly search the free
2823 * list. That corner case is then slower but it is harmless.
2825 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
2828 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2832 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2833 unsigned long mark
, int classzone_idx
)
2835 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2837 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2838 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2840 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2845 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2847 return local_zone
->node
== zone
->node
;
2850 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2852 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2855 #else /* CONFIG_NUMA */
2856 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2861 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2865 #endif /* CONFIG_NUMA */
2867 static void reset_alloc_batches(struct zone
*preferred_zone
)
2869 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2872 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2873 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2874 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2875 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2876 } while (zone
++ != preferred_zone
);
2880 * get_page_from_freelist goes through the zonelist trying to allocate
2883 static struct page
*
2884 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2885 const struct alloc_context
*ac
)
2887 struct zoneref
*z
= ac
->preferred_zoneref
;
2889 bool fair_skipped
= false;
2890 bool apply_fair
= (alloc_flags
& ALLOC_FAIR
);
2894 * Scan zonelist, looking for a zone with enough free.
2895 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2897 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
2902 if (cpusets_enabled() &&
2903 (alloc_flags
& ALLOC_CPUSET
) &&
2904 !__cpuset_zone_allowed(zone
, gfp_mask
))
2907 * Distribute pages in proportion to the individual
2908 * zone size to ensure fair page aging. The zone a
2909 * page was allocated in should have no effect on the
2910 * time the page has in memory before being reclaimed.
2913 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2914 fair_skipped
= true;
2917 if (!zone_local(ac
->preferred_zoneref
->zone
, zone
)) {
2924 * When allocating a page cache page for writing, we
2925 * want to get it from a zone that is within its dirty
2926 * limit, such that no single zone holds more than its
2927 * proportional share of globally allowed dirty pages.
2928 * The dirty limits take into account the zone's
2929 * lowmem reserves and high watermark so that kswapd
2930 * should be able to balance it without having to
2931 * write pages from its LRU list.
2933 * This may look like it could increase pressure on
2934 * lower zones by failing allocations in higher zones
2935 * before they are full. But the pages that do spill
2936 * over are limited as the lower zones are protected
2937 * by this very same mechanism. It should not become
2938 * a practical burden to them.
2940 * XXX: For now, allow allocations to potentially
2941 * exceed the per-zone dirty limit in the slowpath
2942 * (spread_dirty_pages unset) before going into reclaim,
2943 * which is important when on a NUMA setup the allowed
2944 * zones are together not big enough to reach the
2945 * global limit. The proper fix for these situations
2946 * will require awareness of zones in the
2947 * dirty-throttling and the flusher threads.
2949 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2952 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2953 if (!zone_watermark_fast(zone
, order
, mark
,
2954 ac_classzone_idx(ac
), alloc_flags
)) {
2957 /* Checked here to keep the fast path fast */
2958 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2959 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2962 if (zone_reclaim_mode
== 0 ||
2963 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
2966 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2968 case ZONE_RECLAIM_NOSCAN
:
2971 case ZONE_RECLAIM_FULL
:
2972 /* scanned but unreclaimable */
2975 /* did we reclaim enough */
2976 if (zone_watermark_ok(zone
, order
, mark
,
2977 ac_classzone_idx(ac
), alloc_flags
))
2985 page
= buffered_rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
2986 gfp_mask
, alloc_flags
, ac
->migratetype
);
2988 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
2991 * If this is a high-order atomic allocation then check
2992 * if the pageblock should be reserved for the future
2994 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2995 reserve_highatomic_pageblock(page
, zone
, order
);
3002 * The first pass makes sure allocations are spread fairly within the
3003 * local node. However, the local node might have free pages left
3004 * after the fairness batches are exhausted, and remote zones haven't
3005 * even been considered yet. Try once more without fairness, and
3006 * include remote zones now, before entering the slowpath and waking
3007 * kswapd: prefer spilling to a remote zone over swapping locally.
3012 fair_skipped
= false;
3013 reset_alloc_batches(ac
->preferred_zoneref
->zone
);
3014 z
= ac
->preferred_zoneref
;
3022 * Large machines with many possible nodes should not always dump per-node
3023 * meminfo in irq context.
3025 static inline bool should_suppress_show_mem(void)
3030 ret
= in_interrupt();
3035 static DEFINE_RATELIMIT_STATE(nopage_rs
,
3036 DEFAULT_RATELIMIT_INTERVAL
,
3037 DEFAULT_RATELIMIT_BURST
);
3039 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
3041 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3043 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
3044 debug_guardpage_minorder() > 0)
3048 * This documents exceptions given to allocations in certain
3049 * contexts that are allowed to allocate outside current's set
3052 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3053 if (test_thread_flag(TIF_MEMDIE
) ||
3054 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3055 filter
&= ~SHOW_MEM_FILTER_NODES
;
3056 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3057 filter
&= ~SHOW_MEM_FILTER_NODES
;
3060 struct va_format vaf
;
3063 va_start(args
, fmt
);
3068 pr_warn("%pV", &vaf
);
3073 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3074 current
->comm
, order
, gfp_mask
, &gfp_mask
);
3076 if (!should_suppress_show_mem())
3080 static inline struct page
*
3081 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3082 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3084 struct oom_control oc
= {
3085 .zonelist
= ac
->zonelist
,
3086 .nodemask
= ac
->nodemask
,
3088 .gfp_mask
= gfp_mask
,
3093 *did_some_progress
= 0;
3096 * Acquire the oom lock. If that fails, somebody else is
3097 * making progress for us.
3099 if (!mutex_trylock(&oom_lock
)) {
3100 *did_some_progress
= 1;
3101 schedule_timeout_uninterruptible(1);
3106 * Go through the zonelist yet one more time, keep very high watermark
3107 * here, this is only to catch a parallel oom killing, we must fail if
3108 * we're still under heavy pressure.
3110 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3111 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3115 if (!(gfp_mask
& __GFP_NOFAIL
)) {
3116 /* Coredumps can quickly deplete all memory reserves */
3117 if (current
->flags
& PF_DUMPCORE
)
3119 /* The OOM killer will not help higher order allocs */
3120 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3122 /* The OOM killer does not needlessly kill tasks for lowmem */
3123 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3125 if (pm_suspended_storage())
3128 * XXX: GFP_NOFS allocations should rather fail than rely on
3129 * other request to make a forward progress.
3130 * We are in an unfortunate situation where out_of_memory cannot
3131 * do much for this context but let's try it to at least get
3132 * access to memory reserved if the current task is killed (see
3133 * out_of_memory). Once filesystems are ready to handle allocation
3134 * failures more gracefully we should just bail out here.
3137 /* The OOM killer may not free memory on a specific node */
3138 if (gfp_mask
& __GFP_THISNODE
)
3141 /* Exhausted what can be done so it's blamo time */
3142 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3143 *did_some_progress
= 1;
3145 if (gfp_mask
& __GFP_NOFAIL
) {
3146 page
= get_page_from_freelist(gfp_mask
, order
,
3147 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
3149 * fallback to ignore cpuset restriction if our nodes
3153 page
= get_page_from_freelist(gfp_mask
, order
,
3154 ALLOC_NO_WATERMARKS
, ac
);
3158 mutex_unlock(&oom_lock
);
3164 * Maximum number of compaction retries wit a progress before OOM
3165 * killer is consider as the only way to move forward.
3167 #define MAX_COMPACT_RETRIES 16
3169 #ifdef CONFIG_COMPACTION
3170 /* Try memory compaction for high-order allocations before reclaim */
3171 static struct page
*
3172 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3173 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3174 enum migrate_mode mode
, enum compact_result
*compact_result
)
3177 int contended_compaction
;
3182 current
->flags
|= PF_MEMALLOC
;
3183 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3184 mode
, &contended_compaction
);
3185 current
->flags
&= ~PF_MEMALLOC
;
3187 if (*compact_result
<= COMPACT_INACTIVE
)
3191 * At least in one zone compaction wasn't deferred or skipped, so let's
3192 * count a compaction stall
3194 count_vm_event(COMPACTSTALL
);
3196 page
= get_page_from_freelist(gfp_mask
, order
,
3197 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3200 struct zone
*zone
= page_zone(page
);
3202 zone
->compact_blockskip_flush
= false;
3203 compaction_defer_reset(zone
, order
, true);
3204 count_vm_event(COMPACTSUCCESS
);
3209 * It's bad if compaction run occurs and fails. The most likely reason
3210 * is that pages exist, but not enough to satisfy watermarks.
3212 count_vm_event(COMPACTFAIL
);
3215 * In all zones where compaction was attempted (and not
3216 * deferred or skipped), lock contention has been detected.
3217 * For THP allocation we do not want to disrupt the others
3218 * so we fallback to base pages instead.
3220 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3221 *compact_result
= COMPACT_CONTENDED
;
3224 * If compaction was aborted due to need_resched(), we do not
3225 * want to further increase allocation latency, unless it is
3226 * khugepaged trying to collapse.
3228 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3229 && !(current
->flags
& PF_KTHREAD
))
3230 *compact_result
= COMPACT_CONTENDED
;
3238 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3239 enum compact_result compact_result
, enum migrate_mode
*migrate_mode
,
3240 int compaction_retries
)
3242 int max_retries
= MAX_COMPACT_RETRIES
;
3248 * compaction considers all the zone as desperately out of memory
3249 * so it doesn't really make much sense to retry except when the
3250 * failure could be caused by weak migration mode.
3252 if (compaction_failed(compact_result
)) {
3253 if (*migrate_mode
== MIGRATE_ASYNC
) {
3254 *migrate_mode
= MIGRATE_SYNC_LIGHT
;
3261 * make sure the compaction wasn't deferred or didn't bail out early
3262 * due to locks contention before we declare that we should give up.
3263 * But do not retry if the given zonelist is not suitable for
3266 if (compaction_withdrawn(compact_result
))
3267 return compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3270 * !costly requests are much more important than __GFP_REPEAT
3271 * costly ones because they are de facto nofail and invoke OOM
3272 * killer to move on while costly can fail and users are ready
3273 * to cope with that. 1/4 retries is rather arbitrary but we
3274 * would need much more detailed feedback from compaction to
3275 * make a better decision.
3277 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3279 if (compaction_retries
<= max_retries
)
3285 static inline struct page
*
3286 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3287 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3288 enum migrate_mode mode
, enum compact_result
*compact_result
)
3290 *compact_result
= COMPACT_SKIPPED
;
3295 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3296 enum compact_result compact_result
,
3297 enum migrate_mode
*migrate_mode
,
3298 int compaction_retries
)
3303 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3307 * There are setups with compaction disabled which would prefer to loop
3308 * inside the allocator rather than hit the oom killer prematurely.
3309 * Let's give them a good hope and keep retrying while the order-0
3310 * watermarks are OK.
3312 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3314 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3315 ac_classzone_idx(ac
), alloc_flags
))
3320 #endif /* CONFIG_COMPACTION */
3322 /* Perform direct synchronous page reclaim */
3324 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3325 const struct alloc_context
*ac
)
3327 struct reclaim_state reclaim_state
;
3332 /* We now go into synchronous reclaim */
3333 cpuset_memory_pressure_bump();
3334 current
->flags
|= PF_MEMALLOC
;
3335 lockdep_set_current_reclaim_state(gfp_mask
);
3336 reclaim_state
.reclaimed_slab
= 0;
3337 current
->reclaim_state
= &reclaim_state
;
3339 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3342 current
->reclaim_state
= NULL
;
3343 lockdep_clear_current_reclaim_state();
3344 current
->flags
&= ~PF_MEMALLOC
;
3351 /* The really slow allocator path where we enter direct reclaim */
3352 static inline struct page
*
3353 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3354 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3355 unsigned long *did_some_progress
)
3357 struct page
*page
= NULL
;
3358 bool drained
= false;
3360 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3361 if (unlikely(!(*did_some_progress
)))
3365 page
= get_page_from_freelist(gfp_mask
, order
,
3366 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3369 * If an allocation failed after direct reclaim, it could be because
3370 * pages are pinned on the per-cpu lists or in high alloc reserves.
3371 * Shrink them them and try again
3373 if (!page
&& !drained
) {
3374 unreserve_highatomic_pageblock(ac
);
3375 drain_all_pages(NULL
);
3383 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3388 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3389 ac
->high_zoneidx
, ac
->nodemask
)
3390 wakeup_kswapd(zone
, order
, ac_classzone_idx(ac
));
3393 static inline unsigned int
3394 gfp_to_alloc_flags(gfp_t gfp_mask
)
3396 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3398 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3399 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3402 * The caller may dip into page reserves a bit more if the caller
3403 * cannot run direct reclaim, or if the caller has realtime scheduling
3404 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3405 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3407 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3409 if (gfp_mask
& __GFP_ATOMIC
) {
3411 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3412 * if it can't schedule.
3414 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3415 alloc_flags
|= ALLOC_HARDER
;
3417 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3418 * comment for __cpuset_node_allowed().
3420 alloc_flags
&= ~ALLOC_CPUSET
;
3421 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3422 alloc_flags
|= ALLOC_HARDER
;
3424 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3425 if (gfp_mask
& __GFP_MEMALLOC
)
3426 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3427 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3428 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3429 else if (!in_interrupt() &&
3430 ((current
->flags
& PF_MEMALLOC
) ||
3431 unlikely(test_thread_flag(TIF_MEMDIE
))))
3432 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3435 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3436 alloc_flags
|= ALLOC_CMA
;
3441 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3443 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3446 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3448 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3452 * Maximum number of reclaim retries without any progress before OOM killer
3453 * is consider as the only way to move forward.
3455 #define MAX_RECLAIM_RETRIES 16
3458 * Checks whether it makes sense to retry the reclaim to make a forward progress
3459 * for the given allocation request.
3460 * The reclaim feedback represented by did_some_progress (any progress during
3461 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3462 * any progress in a row) is considered as well as the reclaimable pages on the
3463 * applicable zone list (with a backoff mechanism which is a function of
3464 * no_progress_loops).
3466 * Returns true if a retry is viable or false to enter the oom path.
3469 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3470 struct alloc_context
*ac
, int alloc_flags
,
3471 bool did_some_progress
, int no_progress_loops
)
3477 * Make sure we converge to OOM if we cannot make any progress
3478 * several times in the row.
3480 if (no_progress_loops
> MAX_RECLAIM_RETRIES
)
3484 * Keep reclaiming pages while there is a chance this will lead somewhere.
3485 * If none of the target zones can satisfy our allocation request even
3486 * if all reclaimable pages are considered then we are screwed and have
3489 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3491 unsigned long available
;
3492 unsigned long reclaimable
;
3494 available
= reclaimable
= zone_reclaimable_pages(zone
);
3495 available
-= DIV_ROUND_UP(no_progress_loops
* available
,
3496 MAX_RECLAIM_RETRIES
);
3497 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3500 * Would the allocation succeed if we reclaimed the whole
3503 if (__zone_watermark_ok(zone
, order
, min_wmark_pages(zone
),
3504 ac_classzone_idx(ac
), alloc_flags
, available
)) {
3506 * If we didn't make any progress and have a lot of
3507 * dirty + writeback pages then we should wait for
3508 * an IO to complete to slow down the reclaim and
3509 * prevent from pre mature OOM
3511 if (!did_some_progress
) {
3512 unsigned long writeback
;
3513 unsigned long dirty
;
3515 writeback
= zone_page_state_snapshot(zone
,
3517 dirty
= zone_page_state_snapshot(zone
, NR_FILE_DIRTY
);
3519 if (2*(writeback
+ dirty
) > reclaimable
) {
3520 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3526 * Memory allocation/reclaim might be called from a WQ
3527 * context and the current implementation of the WQ
3528 * concurrency control doesn't recognize that
3529 * a particular WQ is congested if the worker thread is
3530 * looping without ever sleeping. Therefore we have to
3531 * do a short sleep here rather than calling
3534 if (current
->flags
& PF_WQ_WORKER
)
3535 schedule_timeout_uninterruptible(1);
3546 static inline struct page
*
3547 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3548 struct alloc_context
*ac
)
3550 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3551 struct page
*page
= NULL
;
3552 unsigned int alloc_flags
;
3553 unsigned long did_some_progress
;
3554 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3555 enum compact_result compact_result
;
3556 int compaction_retries
= 0;
3557 int no_progress_loops
= 0;
3560 * In the slowpath, we sanity check order to avoid ever trying to
3561 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3562 * be using allocators in order of preference for an area that is
3565 if (order
>= MAX_ORDER
) {
3566 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3571 * We also sanity check to catch abuse of atomic reserves being used by
3572 * callers that are not in atomic context.
3574 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3575 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3576 gfp_mask
&= ~__GFP_ATOMIC
;
3579 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3580 wake_all_kswapds(order
, ac
);
3583 * OK, we're below the kswapd watermark and have kicked background
3584 * reclaim. Now things get more complex, so set up alloc_flags according
3585 * to how we want to proceed.
3587 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3590 * Reset the zonelist iterators if memory policies can be ignored.
3591 * These allocations are high priority and system rather than user
3594 if ((alloc_flags
& ALLOC_NO_WATERMARKS
) || !(alloc_flags
& ALLOC_CPUSET
)) {
3595 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3596 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3597 ac
->high_zoneidx
, ac
->nodemask
);
3600 /* This is the last chance, in general, before the goto nopage. */
3601 page
= get_page_from_freelist(gfp_mask
, order
,
3602 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3606 /* Allocate without watermarks if the context allows */
3607 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3608 page
= get_page_from_freelist(gfp_mask
, order
,
3609 ALLOC_NO_WATERMARKS
, ac
);
3614 /* Caller is not willing to reclaim, we can't balance anything */
3615 if (!can_direct_reclaim
) {
3617 * All existing users of the __GFP_NOFAIL are blockable, so warn
3618 * of any new users that actually allow this type of allocation
3621 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3625 /* Avoid recursion of direct reclaim */
3626 if (current
->flags
& PF_MEMALLOC
) {
3628 * __GFP_NOFAIL request from this context is rather bizarre
3629 * because we cannot reclaim anything and only can loop waiting
3630 * for somebody to do a work for us.
3632 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3639 /* Avoid allocations with no watermarks from looping endlessly */
3640 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3644 * Try direct compaction. The first pass is asynchronous. Subsequent
3645 * attempts after direct reclaim are synchronous
3647 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3653 /* Checks for THP-specific high-order allocations */
3654 if (is_thp_gfp_mask(gfp_mask
)) {
3656 * If compaction is deferred for high-order allocations, it is
3657 * because sync compaction recently failed. If this is the case
3658 * and the caller requested a THP allocation, we do not want
3659 * to heavily disrupt the system, so we fail the allocation
3660 * instead of entering direct reclaim.
3662 if (compact_result
== COMPACT_DEFERRED
)
3666 * Compaction is contended so rather back off than cause
3669 if(compact_result
== COMPACT_CONTENDED
)
3673 if (order
&& compaction_made_progress(compact_result
))
3674 compaction_retries
++;
3676 /* Try direct reclaim and then allocating */
3677 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3678 &did_some_progress
);
3682 /* Do not loop if specifically requested */
3683 if (gfp_mask
& __GFP_NORETRY
)
3687 * Do not retry costly high order allocations unless they are
3690 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_REPEAT
))
3694 * Costly allocations might have made a progress but this doesn't mean
3695 * their order will become available due to high fragmentation so
3696 * always increment the no progress counter for them
3698 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3699 no_progress_loops
= 0;
3701 no_progress_loops
++;
3703 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3704 did_some_progress
> 0, no_progress_loops
))
3708 * It doesn't make any sense to retry for the compaction if the order-0
3709 * reclaim is not able to make any progress because the current
3710 * implementation of the compaction depends on the sufficient amount
3711 * of free memory (see __compaction_suitable)
3713 if (did_some_progress
> 0 &&
3714 should_compact_retry(ac
, order
, alloc_flags
,
3715 compact_result
, &migration_mode
,
3716 compaction_retries
))
3719 /* Reclaim has failed us, start killing things */
3720 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3724 /* Retry as long as the OOM killer is making progress */
3725 if (did_some_progress
) {
3726 no_progress_loops
= 0;
3732 * High-order allocations do not necessarily loop after direct reclaim
3733 * and reclaim/compaction depends on compaction being called after
3734 * reclaim so call directly if necessary.
3735 * It can become very expensive to allocate transparent hugepages at
3736 * fault, so use asynchronous memory compaction for THP unless it is
3737 * khugepaged trying to collapse. All other requests should tolerate
3738 * at least light sync migration.
3740 if (is_thp_gfp_mask(gfp_mask
) && !(current
->flags
& PF_KTHREAD
))
3741 migration_mode
= MIGRATE_ASYNC
;
3743 migration_mode
= MIGRATE_SYNC_LIGHT
;
3744 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3750 warn_alloc_failed(gfp_mask
, order
, NULL
);
3756 * This is the 'heart' of the zoned buddy allocator.
3759 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3760 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3763 unsigned int cpuset_mems_cookie
;
3764 unsigned int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_FAIR
;
3765 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
3766 struct alloc_context ac
= {
3767 .high_zoneidx
= gfp_zone(gfp_mask
),
3768 .zonelist
= zonelist
,
3769 .nodemask
= nodemask
,
3770 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3773 if (cpusets_enabled()) {
3774 alloc_mask
|= __GFP_HARDWALL
;
3775 alloc_flags
|= ALLOC_CPUSET
;
3777 ac
.nodemask
= &cpuset_current_mems_allowed
;
3780 gfp_mask
&= gfp_allowed_mask
;
3782 lockdep_trace_alloc(gfp_mask
);
3784 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3786 if (should_fail_alloc_page(gfp_mask
, order
))
3790 * Check the zones suitable for the gfp_mask contain at least one
3791 * valid zone. It's possible to have an empty zonelist as a result
3792 * of __GFP_THISNODE and a memoryless node
3794 if (unlikely(!zonelist
->_zonerefs
->zone
))
3797 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3798 alloc_flags
|= ALLOC_CMA
;
3801 cpuset_mems_cookie
= read_mems_allowed_begin();
3803 /* Dirty zone balancing only done in the fast path */
3804 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3807 * The preferred zone is used for statistics but crucially it is
3808 * also used as the starting point for the zonelist iterator. It
3809 * may get reset for allocations that ignore memory policies.
3811 ac
.preferred_zoneref
= first_zones_zonelist(ac
.zonelist
,
3812 ac
.high_zoneidx
, ac
.nodemask
);
3813 if (!ac
.preferred_zoneref
) {
3818 /* First allocation attempt */
3819 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3824 * Runtime PM, block IO and its error handling path can deadlock
3825 * because I/O on the device might not complete.
3827 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3828 ac
.spread_dirty_pages
= false;
3831 * Restore the original nodemask if it was potentially replaced with
3832 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3834 if (cpusets_enabled())
3835 ac
.nodemask
= nodemask
;
3836 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3840 * When updating a task's mems_allowed, it is possible to race with
3841 * parallel threads in such a way that an allocation can fail while
3842 * the mask is being updated. If a page allocation is about to fail,
3843 * check if the cpuset changed during allocation and if so, retry.
3845 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
))) {
3846 alloc_mask
= gfp_mask
;
3851 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
) {
3852 if (unlikely(memcg_kmem_charge(page
, gfp_mask
, order
))) {
3853 __free_pages(page
, order
);
3856 __SetPageKmemcg(page
);
3859 if (kmemcheck_enabled
&& page
)
3860 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3862 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3866 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3869 * Common helper functions.
3871 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3876 * __get_free_pages() returns a 32-bit address, which cannot represent
3879 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3881 page
= alloc_pages(gfp_mask
, order
);
3884 return (unsigned long) page_address(page
);
3886 EXPORT_SYMBOL(__get_free_pages
);
3888 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3890 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3892 EXPORT_SYMBOL(get_zeroed_page
);
3894 void __free_pages(struct page
*page
, unsigned int order
)
3896 if (put_page_testzero(page
)) {
3898 free_hot_cold_page(page
, false);
3900 __free_pages_ok(page
, order
);
3904 EXPORT_SYMBOL(__free_pages
);
3906 void free_pages(unsigned long addr
, unsigned int order
)
3909 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3910 __free_pages(virt_to_page((void *)addr
), order
);
3914 EXPORT_SYMBOL(free_pages
);
3918 * An arbitrary-length arbitrary-offset area of memory which resides
3919 * within a 0 or higher order page. Multiple fragments within that page
3920 * are individually refcounted, in the page's reference counter.
3922 * The page_frag functions below provide a simple allocation framework for
3923 * page fragments. This is used by the network stack and network device
3924 * drivers to provide a backing region of memory for use as either an
3925 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3927 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3930 struct page
*page
= NULL
;
3931 gfp_t gfp
= gfp_mask
;
3933 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3934 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3936 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3937 PAGE_FRAG_CACHE_MAX_ORDER
);
3938 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3940 if (unlikely(!page
))
3941 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3943 nc
->va
= page
? page_address(page
) : NULL
;
3948 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3949 unsigned int fragsz
, gfp_t gfp_mask
)
3951 unsigned int size
= PAGE_SIZE
;
3955 if (unlikely(!nc
->va
)) {
3957 page
= __page_frag_refill(nc
, gfp_mask
);
3961 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3962 /* if size can vary use size else just use PAGE_SIZE */
3965 /* Even if we own the page, we do not use atomic_set().
3966 * This would break get_page_unless_zero() users.
3968 page_ref_add(page
, size
- 1);
3970 /* reset page count bias and offset to start of new frag */
3971 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3972 nc
->pagecnt_bias
= size
;
3976 offset
= nc
->offset
- fragsz
;
3977 if (unlikely(offset
< 0)) {
3978 page
= virt_to_page(nc
->va
);
3980 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3983 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3984 /* if size can vary use size else just use PAGE_SIZE */
3987 /* OK, page count is 0, we can safely set it */
3988 set_page_count(page
, size
);
3990 /* reset page count bias and offset to start of new frag */
3991 nc
->pagecnt_bias
= size
;
3992 offset
= size
- fragsz
;
3996 nc
->offset
= offset
;
3998 return nc
->va
+ offset
;
4000 EXPORT_SYMBOL(__alloc_page_frag
);
4003 * Frees a page fragment allocated out of either a compound or order 0 page.
4005 void __free_page_frag(void *addr
)
4007 struct page
*page
= virt_to_head_page(addr
);
4009 if (unlikely(put_page_testzero(page
)))
4010 __free_pages_ok(page
, compound_order(page
));
4012 EXPORT_SYMBOL(__free_page_frag
);
4014 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4018 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4019 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4021 split_page(virt_to_page((void *)addr
), order
);
4022 while (used
< alloc_end
) {
4027 return (void *)addr
;
4031 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4032 * @size: the number of bytes to allocate
4033 * @gfp_mask: GFP flags for the allocation
4035 * This function is similar to alloc_pages(), except that it allocates the
4036 * minimum number of pages to satisfy the request. alloc_pages() can only
4037 * allocate memory in power-of-two pages.
4039 * This function is also limited by MAX_ORDER.
4041 * Memory allocated by this function must be released by free_pages_exact().
4043 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4045 unsigned int order
= get_order(size
);
4048 addr
= __get_free_pages(gfp_mask
, order
);
4049 return make_alloc_exact(addr
, order
, size
);
4051 EXPORT_SYMBOL(alloc_pages_exact
);
4054 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4056 * @nid: the preferred node ID where memory should be allocated
4057 * @size: the number of bytes to allocate
4058 * @gfp_mask: GFP flags for the allocation
4060 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4063 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4065 unsigned int order
= get_order(size
);
4066 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4069 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4073 * free_pages_exact - release memory allocated via alloc_pages_exact()
4074 * @virt: the value returned by alloc_pages_exact.
4075 * @size: size of allocation, same value as passed to alloc_pages_exact().
4077 * Release the memory allocated by a previous call to alloc_pages_exact.
4079 void free_pages_exact(void *virt
, size_t size
)
4081 unsigned long addr
= (unsigned long)virt
;
4082 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4084 while (addr
< end
) {
4089 EXPORT_SYMBOL(free_pages_exact
);
4092 * nr_free_zone_pages - count number of pages beyond high watermark
4093 * @offset: The zone index of the highest zone
4095 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4096 * high watermark within all zones at or below a given zone index. For each
4097 * zone, the number of pages is calculated as:
4098 * managed_pages - high_pages
4100 static unsigned long nr_free_zone_pages(int offset
)
4105 /* Just pick one node, since fallback list is circular */
4106 unsigned long sum
= 0;
4108 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4110 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4111 unsigned long size
= zone
->managed_pages
;
4112 unsigned long high
= high_wmark_pages(zone
);
4121 * nr_free_buffer_pages - count number of pages beyond high watermark
4123 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4124 * watermark within ZONE_DMA and ZONE_NORMAL.
4126 unsigned long nr_free_buffer_pages(void)
4128 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4130 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4133 * nr_free_pagecache_pages - count number of pages beyond high watermark
4135 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4136 * high watermark within all zones.
4138 unsigned long nr_free_pagecache_pages(void)
4140 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4143 static inline void show_node(struct zone
*zone
)
4145 if (IS_ENABLED(CONFIG_NUMA
))
4146 printk("Node %d ", zone_to_nid(zone
));
4149 long si_mem_available(void)
4152 unsigned long pagecache
;
4153 unsigned long wmark_low
= 0;
4154 unsigned long pages
[NR_LRU_LISTS
];
4158 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4159 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
4162 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4165 * Estimate the amount of memory available for userspace allocations,
4166 * without causing swapping.
4168 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4171 * Not all the page cache can be freed, otherwise the system will
4172 * start swapping. Assume at least half of the page cache, or the
4173 * low watermark worth of cache, needs to stay.
4175 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4176 pagecache
-= min(pagecache
/ 2, wmark_low
);
4177 available
+= pagecache
;
4180 * Part of the reclaimable slab consists of items that are in use,
4181 * and cannot be freed. Cap this estimate at the low watermark.
4183 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4184 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4190 EXPORT_SYMBOL_GPL(si_mem_available
);
4192 void si_meminfo(struct sysinfo
*val
)
4194 val
->totalram
= totalram_pages
;
4195 val
->sharedram
= global_page_state(NR_SHMEM
);
4196 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4197 val
->bufferram
= nr_blockdev_pages();
4198 val
->totalhigh
= totalhigh_pages
;
4199 val
->freehigh
= nr_free_highpages();
4200 val
->mem_unit
= PAGE_SIZE
;
4203 EXPORT_SYMBOL(si_meminfo
);
4206 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4208 int zone_type
; /* needs to be signed */
4209 unsigned long managed_pages
= 0;
4210 unsigned long managed_highpages
= 0;
4211 unsigned long free_highpages
= 0;
4212 pg_data_t
*pgdat
= NODE_DATA(nid
);
4214 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4215 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4216 val
->totalram
= managed_pages
;
4217 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
4218 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
4219 #ifdef CONFIG_HIGHMEM
4220 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4221 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4223 if (is_highmem(zone
)) {
4224 managed_highpages
+= zone
->managed_pages
;
4225 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4228 val
->totalhigh
= managed_highpages
;
4229 val
->freehigh
= free_highpages
;
4231 val
->totalhigh
= managed_highpages
;
4232 val
->freehigh
= free_highpages
;
4234 val
->mem_unit
= PAGE_SIZE
;
4239 * Determine whether the node should be displayed or not, depending on whether
4240 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4242 bool skip_free_areas_node(unsigned int flags
, int nid
)
4245 unsigned int cpuset_mems_cookie
;
4247 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4251 cpuset_mems_cookie
= read_mems_allowed_begin();
4252 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
4253 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
4258 #define K(x) ((x) << (PAGE_SHIFT-10))
4260 static void show_migration_types(unsigned char type
)
4262 static const char types
[MIGRATE_TYPES
] = {
4263 [MIGRATE_UNMOVABLE
] = 'U',
4264 [MIGRATE_MOVABLE
] = 'M',
4265 [MIGRATE_RECLAIMABLE
] = 'E',
4266 [MIGRATE_HIGHATOMIC
] = 'H',
4268 [MIGRATE_CMA
] = 'C',
4270 #ifdef CONFIG_MEMORY_ISOLATION
4271 [MIGRATE_ISOLATE
] = 'I',
4274 char tmp
[MIGRATE_TYPES
+ 1];
4278 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4279 if (type
& (1 << i
))
4284 printk("(%s) ", tmp
);
4288 * Show free area list (used inside shift_scroll-lock stuff)
4289 * We also calculate the percentage fragmentation. We do this by counting the
4290 * memory on each free list with the exception of the first item on the list.
4293 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4296 void show_free_areas(unsigned int filter
)
4298 unsigned long free_pcp
= 0;
4302 for_each_populated_zone(zone
) {
4303 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4306 for_each_online_cpu(cpu
)
4307 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4310 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4311 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4312 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4313 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4314 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4315 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4316 " anon_thp: %lu shmem_thp: %lu shmem_pmdmapped: %lu\n"
4318 " free:%lu free_pcp:%lu free_cma:%lu\n",
4319 global_page_state(NR_ACTIVE_ANON
),
4320 global_page_state(NR_INACTIVE_ANON
),
4321 global_page_state(NR_ISOLATED_ANON
),
4322 global_page_state(NR_ACTIVE_FILE
),
4323 global_page_state(NR_INACTIVE_FILE
),
4324 global_page_state(NR_ISOLATED_FILE
),
4325 global_page_state(NR_UNEVICTABLE
),
4326 global_page_state(NR_FILE_DIRTY
),
4327 global_page_state(NR_WRITEBACK
),
4328 global_page_state(NR_UNSTABLE_NFS
),
4329 global_page_state(NR_SLAB_RECLAIMABLE
),
4330 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4331 global_page_state(NR_FILE_MAPPED
),
4332 global_page_state(NR_SHMEM
),
4333 global_page_state(NR_PAGETABLE
),
4334 global_page_state(NR_BOUNCE
),
4335 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4336 global_page_state(NR_ANON_THPS
) * HPAGE_PMD_NR
,
4337 global_page_state(NR_SHMEM_THPS
) * HPAGE_PMD_NR
,
4338 global_page_state(NR_SHMEM_PMDMAPPED
) * HPAGE_PMD_NR
,
4340 global_page_state(NR_FREE_PAGES
),
4342 global_page_state(NR_FREE_CMA_PAGES
));
4344 for_each_populated_zone(zone
) {
4347 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4351 for_each_online_cpu(cpu
)
4352 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4360 " active_anon:%lukB"
4361 " inactive_anon:%lukB"
4362 " active_file:%lukB"
4363 " inactive_file:%lukB"
4364 " unevictable:%lukB"
4365 " isolated(anon):%lukB"
4366 " isolated(file):%lukB"
4374 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4376 " shmem_pmdmapped: %lukB"
4379 " slab_reclaimable:%lukB"
4380 " slab_unreclaimable:%lukB"
4381 " kernel_stack:%lukB"
4388 " writeback_tmp:%lukB"
4389 " pages_scanned:%lu"
4390 " all_unreclaimable? %s"
4393 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4394 K(min_wmark_pages(zone
)),
4395 K(low_wmark_pages(zone
)),
4396 K(high_wmark_pages(zone
)),
4397 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
4398 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
4399 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
4400 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
4401 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
4402 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
4403 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
4404 K(zone
->present_pages
),
4405 K(zone
->managed_pages
),
4406 K(zone_page_state(zone
, NR_MLOCK
)),
4407 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
4408 K(zone_page_state(zone
, NR_WRITEBACK
)),
4409 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
4410 K(zone_page_state(zone
, NR_SHMEM
)),
4411 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4412 K(zone_page_state(zone
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4413 K(zone_page_state(zone
, NR_SHMEM_PMDMAPPED
)
4415 K(zone_page_state(zone
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4417 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
4418 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
4419 zone_page_state(zone
, NR_KERNEL_STACK
) *
4421 K(zone_page_state(zone
, NR_PAGETABLE
)),
4422 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
4423 K(zone_page_state(zone
, NR_BOUNCE
)),
4425 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4426 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
4427 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
4428 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
4429 (!zone_reclaimable(zone
) ? "yes" : "no")
4431 printk("lowmem_reserve[]:");
4432 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4433 printk(" %ld", zone
->lowmem_reserve
[i
]);
4437 for_each_populated_zone(zone
) {
4439 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4440 unsigned char types
[MAX_ORDER
];
4442 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4445 printk("%s: ", zone
->name
);
4447 spin_lock_irqsave(&zone
->lock
, flags
);
4448 for (order
= 0; order
< MAX_ORDER
; order
++) {
4449 struct free_area
*area
= &zone
->free_area
[order
];
4452 nr
[order
] = area
->nr_free
;
4453 total
+= nr
[order
] << order
;
4456 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4457 if (!list_empty(&area
->free_list
[type
]))
4458 types
[order
] |= 1 << type
;
4461 spin_unlock_irqrestore(&zone
->lock
, flags
);
4462 for (order
= 0; order
< MAX_ORDER
; order
++) {
4463 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4465 show_migration_types(types
[order
]);
4467 printk("= %lukB\n", K(total
));
4470 hugetlb_show_meminfo();
4472 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4474 show_swap_cache_info();
4477 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4479 zoneref
->zone
= zone
;
4480 zoneref
->zone_idx
= zone_idx(zone
);
4484 * Builds allocation fallback zone lists.
4486 * Add all populated zones of a node to the zonelist.
4488 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4492 enum zone_type zone_type
= MAX_NR_ZONES
;
4496 zone
= pgdat
->node_zones
+ zone_type
;
4497 if (populated_zone(zone
)) {
4498 zoneref_set_zone(zone
,
4499 &zonelist
->_zonerefs
[nr_zones
++]);
4500 check_highest_zone(zone_type
);
4502 } while (zone_type
);
4510 * 0 = automatic detection of better ordering.
4511 * 1 = order by ([node] distance, -zonetype)
4512 * 2 = order by (-zonetype, [node] distance)
4514 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4515 * the same zonelist. So only NUMA can configure this param.
4517 #define ZONELIST_ORDER_DEFAULT 0
4518 #define ZONELIST_ORDER_NODE 1
4519 #define ZONELIST_ORDER_ZONE 2
4521 /* zonelist order in the kernel.
4522 * set_zonelist_order() will set this to NODE or ZONE.
4524 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4525 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4529 /* The value user specified ....changed by config */
4530 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4531 /* string for sysctl */
4532 #define NUMA_ZONELIST_ORDER_LEN 16
4533 char numa_zonelist_order
[16] = "default";
4536 * interface for configure zonelist ordering.
4537 * command line option "numa_zonelist_order"
4538 * = "[dD]efault - default, automatic configuration.
4539 * = "[nN]ode - order by node locality, then by zone within node
4540 * = "[zZ]one - order by zone, then by locality within zone
4543 static int __parse_numa_zonelist_order(char *s
)
4545 if (*s
== 'd' || *s
== 'D') {
4546 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4547 } else if (*s
== 'n' || *s
== 'N') {
4548 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4549 } else if (*s
== 'z' || *s
== 'Z') {
4550 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4552 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4558 static __init
int setup_numa_zonelist_order(char *s
)
4565 ret
= __parse_numa_zonelist_order(s
);
4567 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4571 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4574 * sysctl handler for numa_zonelist_order
4576 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4577 void __user
*buffer
, size_t *length
,
4580 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4582 static DEFINE_MUTEX(zl_order_mutex
);
4584 mutex_lock(&zl_order_mutex
);
4586 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4590 strcpy(saved_string
, (char *)table
->data
);
4592 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4596 int oldval
= user_zonelist_order
;
4598 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4601 * bogus value. restore saved string
4603 strncpy((char *)table
->data
, saved_string
,
4604 NUMA_ZONELIST_ORDER_LEN
);
4605 user_zonelist_order
= oldval
;
4606 } else if (oldval
!= user_zonelist_order
) {
4607 mutex_lock(&zonelists_mutex
);
4608 build_all_zonelists(NULL
, NULL
);
4609 mutex_unlock(&zonelists_mutex
);
4613 mutex_unlock(&zl_order_mutex
);
4618 #define MAX_NODE_LOAD (nr_online_nodes)
4619 static int node_load
[MAX_NUMNODES
];
4622 * find_next_best_node - find the next node that should appear in a given node's fallback list
4623 * @node: node whose fallback list we're appending
4624 * @used_node_mask: nodemask_t of already used nodes
4626 * We use a number of factors to determine which is the next node that should
4627 * appear on a given node's fallback list. The node should not have appeared
4628 * already in @node's fallback list, and it should be the next closest node
4629 * according to the distance array (which contains arbitrary distance values
4630 * from each node to each node in the system), and should also prefer nodes
4631 * with no CPUs, since presumably they'll have very little allocation pressure
4632 * on them otherwise.
4633 * It returns -1 if no node is found.
4635 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4638 int min_val
= INT_MAX
;
4639 int best_node
= NUMA_NO_NODE
;
4640 const struct cpumask
*tmp
= cpumask_of_node(0);
4642 /* Use the local node if we haven't already */
4643 if (!node_isset(node
, *used_node_mask
)) {
4644 node_set(node
, *used_node_mask
);
4648 for_each_node_state(n
, N_MEMORY
) {
4650 /* Don't want a node to appear more than once */
4651 if (node_isset(n
, *used_node_mask
))
4654 /* Use the distance array to find the distance */
4655 val
= node_distance(node
, n
);
4657 /* Penalize nodes under us ("prefer the next node") */
4660 /* Give preference to headless and unused nodes */
4661 tmp
= cpumask_of_node(n
);
4662 if (!cpumask_empty(tmp
))
4663 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4665 /* Slight preference for less loaded node */
4666 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4667 val
+= node_load
[n
];
4669 if (val
< min_val
) {
4676 node_set(best_node
, *used_node_mask
);
4683 * Build zonelists ordered by node and zones within node.
4684 * This results in maximum locality--normal zone overflows into local
4685 * DMA zone, if any--but risks exhausting DMA zone.
4687 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4690 struct zonelist
*zonelist
;
4692 zonelist
= &pgdat
->node_zonelists
[0];
4693 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4695 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4696 zonelist
->_zonerefs
[j
].zone
= NULL
;
4697 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4701 * Build gfp_thisnode zonelists
4703 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4706 struct zonelist
*zonelist
;
4708 zonelist
= &pgdat
->node_zonelists
[1];
4709 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4710 zonelist
->_zonerefs
[j
].zone
= NULL
;
4711 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4715 * Build zonelists ordered by zone and nodes within zones.
4716 * This results in conserving DMA zone[s] until all Normal memory is
4717 * exhausted, but results in overflowing to remote node while memory
4718 * may still exist in local DMA zone.
4720 static int node_order
[MAX_NUMNODES
];
4722 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4725 int zone_type
; /* needs to be signed */
4727 struct zonelist
*zonelist
;
4729 zonelist
= &pgdat
->node_zonelists
[0];
4731 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4732 for (j
= 0; j
< nr_nodes
; j
++) {
4733 node
= node_order
[j
];
4734 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4735 if (populated_zone(z
)) {
4737 &zonelist
->_zonerefs
[pos
++]);
4738 check_highest_zone(zone_type
);
4742 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4743 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4746 #if defined(CONFIG_64BIT)
4748 * Devices that require DMA32/DMA are relatively rare and do not justify a
4749 * penalty to every machine in case the specialised case applies. Default
4750 * to Node-ordering on 64-bit NUMA machines
4752 static int default_zonelist_order(void)
4754 return ZONELIST_ORDER_NODE
;
4758 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4759 * by the kernel. If processes running on node 0 deplete the low memory zone
4760 * then reclaim will occur more frequency increasing stalls and potentially
4761 * be easier to OOM if a large percentage of the zone is under writeback or
4762 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4763 * Hence, default to zone ordering on 32-bit.
4765 static int default_zonelist_order(void)
4767 return ZONELIST_ORDER_ZONE
;
4769 #endif /* CONFIG_64BIT */
4771 static void set_zonelist_order(void)
4773 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4774 current_zonelist_order
= default_zonelist_order();
4776 current_zonelist_order
= user_zonelist_order
;
4779 static void build_zonelists(pg_data_t
*pgdat
)
4782 nodemask_t used_mask
;
4783 int local_node
, prev_node
;
4784 struct zonelist
*zonelist
;
4785 unsigned int order
= current_zonelist_order
;
4787 /* initialize zonelists */
4788 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4789 zonelist
= pgdat
->node_zonelists
+ i
;
4790 zonelist
->_zonerefs
[0].zone
= NULL
;
4791 zonelist
->_zonerefs
[0].zone_idx
= 0;
4794 /* NUMA-aware ordering of nodes */
4795 local_node
= pgdat
->node_id
;
4796 load
= nr_online_nodes
;
4797 prev_node
= local_node
;
4798 nodes_clear(used_mask
);
4800 memset(node_order
, 0, sizeof(node_order
));
4803 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4805 * We don't want to pressure a particular node.
4806 * So adding penalty to the first node in same
4807 * distance group to make it round-robin.
4809 if (node_distance(local_node
, node
) !=
4810 node_distance(local_node
, prev_node
))
4811 node_load
[node
] = load
;
4815 if (order
== ZONELIST_ORDER_NODE
)
4816 build_zonelists_in_node_order(pgdat
, node
);
4818 node_order
[i
++] = node
; /* remember order */
4821 if (order
== ZONELIST_ORDER_ZONE
) {
4822 /* calculate node order -- i.e., DMA last! */
4823 build_zonelists_in_zone_order(pgdat
, i
);
4826 build_thisnode_zonelists(pgdat
);
4829 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4831 * Return node id of node used for "local" allocations.
4832 * I.e., first node id of first zone in arg node's generic zonelist.
4833 * Used for initializing percpu 'numa_mem', which is used primarily
4834 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4836 int local_memory_node(int node
)
4840 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4841 gfp_zone(GFP_KERNEL
),
4843 return z
->zone
->node
;
4847 #else /* CONFIG_NUMA */
4849 static void set_zonelist_order(void)
4851 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4854 static void build_zonelists(pg_data_t
*pgdat
)
4856 int node
, local_node
;
4858 struct zonelist
*zonelist
;
4860 local_node
= pgdat
->node_id
;
4862 zonelist
= &pgdat
->node_zonelists
[0];
4863 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4866 * Now we build the zonelist so that it contains the zones
4867 * of all the other nodes.
4868 * We don't want to pressure a particular node, so when
4869 * building the zones for node N, we make sure that the
4870 * zones coming right after the local ones are those from
4871 * node N+1 (modulo N)
4873 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4874 if (!node_online(node
))
4876 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4878 for (node
= 0; node
< local_node
; node
++) {
4879 if (!node_online(node
))
4881 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4884 zonelist
->_zonerefs
[j
].zone
= NULL
;
4885 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4888 #endif /* CONFIG_NUMA */
4891 * Boot pageset table. One per cpu which is going to be used for all
4892 * zones and all nodes. The parameters will be set in such a way
4893 * that an item put on a list will immediately be handed over to
4894 * the buddy list. This is safe since pageset manipulation is done
4895 * with interrupts disabled.
4897 * The boot_pagesets must be kept even after bootup is complete for
4898 * unused processors and/or zones. They do play a role for bootstrapping
4899 * hotplugged processors.
4901 * zoneinfo_show() and maybe other functions do
4902 * not check if the processor is online before following the pageset pointer.
4903 * Other parts of the kernel may not check if the zone is available.
4905 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4906 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4907 static void setup_zone_pageset(struct zone
*zone
);
4910 * Global mutex to protect against size modification of zonelists
4911 * as well as to serialize pageset setup for the new populated zone.
4913 DEFINE_MUTEX(zonelists_mutex
);
4915 /* return values int ....just for stop_machine() */
4916 static int __build_all_zonelists(void *data
)
4920 pg_data_t
*self
= data
;
4923 memset(node_load
, 0, sizeof(node_load
));
4926 if (self
&& !node_online(self
->node_id
)) {
4927 build_zonelists(self
);
4930 for_each_online_node(nid
) {
4931 pg_data_t
*pgdat
= NODE_DATA(nid
);
4933 build_zonelists(pgdat
);
4937 * Initialize the boot_pagesets that are going to be used
4938 * for bootstrapping processors. The real pagesets for
4939 * each zone will be allocated later when the per cpu
4940 * allocator is available.
4942 * boot_pagesets are used also for bootstrapping offline
4943 * cpus if the system is already booted because the pagesets
4944 * are needed to initialize allocators on a specific cpu too.
4945 * F.e. the percpu allocator needs the page allocator which
4946 * needs the percpu allocator in order to allocate its pagesets
4947 * (a chicken-egg dilemma).
4949 for_each_possible_cpu(cpu
) {
4950 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4952 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4954 * We now know the "local memory node" for each node--
4955 * i.e., the node of the first zone in the generic zonelist.
4956 * Set up numa_mem percpu variable for on-line cpus. During
4957 * boot, only the boot cpu should be on-line; we'll init the
4958 * secondary cpus' numa_mem as they come on-line. During
4959 * node/memory hotplug, we'll fixup all on-line cpus.
4961 if (cpu_online(cpu
))
4962 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4969 static noinline
void __init
4970 build_all_zonelists_init(void)
4972 __build_all_zonelists(NULL
);
4973 mminit_verify_zonelist();
4974 cpuset_init_current_mems_allowed();
4978 * Called with zonelists_mutex held always
4979 * unless system_state == SYSTEM_BOOTING.
4981 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4982 * [we're only called with non-NULL zone through __meminit paths] and
4983 * (2) call of __init annotated helper build_all_zonelists_init
4984 * [protected by SYSTEM_BOOTING].
4986 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4988 set_zonelist_order();
4990 if (system_state
== SYSTEM_BOOTING
) {
4991 build_all_zonelists_init();
4993 #ifdef CONFIG_MEMORY_HOTPLUG
4995 setup_zone_pageset(zone
);
4997 /* we have to stop all cpus to guarantee there is no user
4999 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
5000 /* cpuset refresh routine should be here */
5002 vm_total_pages
= nr_free_pagecache_pages();
5004 * Disable grouping by mobility if the number of pages in the
5005 * system is too low to allow the mechanism to work. It would be
5006 * more accurate, but expensive to check per-zone. This check is
5007 * made on memory-hotadd so a system can start with mobility
5008 * disabled and enable it later
5010 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5011 page_group_by_mobility_disabled
= 1;
5013 page_group_by_mobility_disabled
= 0;
5015 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5017 zonelist_order_name
[current_zonelist_order
],
5018 page_group_by_mobility_disabled
? "off" : "on",
5021 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5026 * Helper functions to size the waitqueue hash table.
5027 * Essentially these want to choose hash table sizes sufficiently
5028 * large so that collisions trying to wait on pages are rare.
5029 * But in fact, the number of active page waitqueues on typical
5030 * systems is ridiculously low, less than 200. So this is even
5031 * conservative, even though it seems large.
5033 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
5034 * waitqueues, i.e. the size of the waitq table given the number of pages.
5036 #define PAGES_PER_WAITQUEUE 256
5038 #ifndef CONFIG_MEMORY_HOTPLUG
5039 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5041 unsigned long size
= 1;
5043 pages
/= PAGES_PER_WAITQUEUE
;
5045 while (size
< pages
)
5049 * Once we have dozens or even hundreds of threads sleeping
5050 * on IO we've got bigger problems than wait queue collision.
5051 * Limit the size of the wait table to a reasonable size.
5053 size
= min(size
, 4096UL);
5055 return max(size
, 4UL);
5059 * A zone's size might be changed by hot-add, so it is not possible to determine
5060 * a suitable size for its wait_table. So we use the maximum size now.
5062 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5064 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5065 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5066 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5068 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5069 * or more by the traditional way. (See above). It equals:
5071 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5072 * ia64(16K page size) : = ( 8G + 4M)byte.
5073 * powerpc (64K page size) : = (32G +16M)byte.
5075 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5082 * This is an integer logarithm so that shifts can be used later
5083 * to extract the more random high bits from the multiplicative
5084 * hash function before the remainder is taken.
5086 static inline unsigned long wait_table_bits(unsigned long size
)
5092 * Initially all pages are reserved - free ones are freed
5093 * up by free_all_bootmem() once the early boot process is
5094 * done. Non-atomic initialization, single-pass.
5096 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5097 unsigned long start_pfn
, enum memmap_context context
)
5099 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5100 unsigned long end_pfn
= start_pfn
+ size
;
5101 pg_data_t
*pgdat
= NODE_DATA(nid
);
5103 unsigned long nr_initialised
= 0;
5104 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5105 struct memblock_region
*r
= NULL
, *tmp
;
5108 if (highest_memmap_pfn
< end_pfn
- 1)
5109 highest_memmap_pfn
= end_pfn
- 1;
5112 * Honor reservation requested by the driver for this ZONE_DEVICE
5115 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5116 start_pfn
+= altmap
->reserve
;
5118 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5120 * There can be holes in boot-time mem_map[]s handed to this
5121 * function. They do not exist on hotplugged memory.
5123 if (context
!= MEMMAP_EARLY
)
5126 if (!early_pfn_valid(pfn
))
5128 if (!early_pfn_in_nid(pfn
, nid
))
5130 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5133 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5135 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5136 * from zone_movable_pfn[nid] to end of each node should be
5137 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5139 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
5140 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
5144 * Check given memblock attribute by firmware which can affect
5145 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5146 * mirrored, it's an overlapped memmap init. skip it.
5148 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5149 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5150 for_each_memblock(memory
, tmp
)
5151 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5155 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5156 memblock_is_mirror(r
)) {
5157 /* already initialized as NORMAL */
5158 pfn
= memblock_region_memory_end_pfn(r
);
5166 * Mark the block movable so that blocks are reserved for
5167 * movable at startup. This will force kernel allocations
5168 * to reserve their blocks rather than leaking throughout
5169 * the address space during boot when many long-lived
5170 * kernel allocations are made.
5172 * bitmap is created for zone's valid pfn range. but memmap
5173 * can be created for invalid pages (for alignment)
5174 * check here not to call set_pageblock_migratetype() against
5177 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5178 struct page
*page
= pfn_to_page(pfn
);
5180 __init_single_page(page
, pfn
, zone
, nid
);
5181 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5183 __init_single_pfn(pfn
, zone
, nid
);
5188 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5190 unsigned int order
, t
;
5191 for_each_migratetype_order(order
, t
) {
5192 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5193 zone
->free_area
[order
].nr_free
= 0;
5197 #ifndef __HAVE_ARCH_MEMMAP_INIT
5198 #define memmap_init(size, nid, zone, start_pfn) \
5199 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5202 static int zone_batchsize(struct zone
*zone
)
5208 * The per-cpu-pages pools are set to around 1000th of the
5209 * size of the zone. But no more than 1/2 of a meg.
5211 * OK, so we don't know how big the cache is. So guess.
5213 batch
= zone
->managed_pages
/ 1024;
5214 if (batch
* PAGE_SIZE
> 512 * 1024)
5215 batch
= (512 * 1024) / PAGE_SIZE
;
5216 batch
/= 4; /* We effectively *= 4 below */
5221 * Clamp the batch to a 2^n - 1 value. Having a power
5222 * of 2 value was found to be more likely to have
5223 * suboptimal cache aliasing properties in some cases.
5225 * For example if 2 tasks are alternately allocating
5226 * batches of pages, one task can end up with a lot
5227 * of pages of one half of the possible page colors
5228 * and the other with pages of the other colors.
5230 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5235 /* The deferral and batching of frees should be suppressed under NOMMU
5238 * The problem is that NOMMU needs to be able to allocate large chunks
5239 * of contiguous memory as there's no hardware page translation to
5240 * assemble apparent contiguous memory from discontiguous pages.
5242 * Queueing large contiguous runs of pages for batching, however,
5243 * causes the pages to actually be freed in smaller chunks. As there
5244 * can be a significant delay between the individual batches being
5245 * recycled, this leads to the once large chunks of space being
5246 * fragmented and becoming unavailable for high-order allocations.
5253 * pcp->high and pcp->batch values are related and dependent on one another:
5254 * ->batch must never be higher then ->high.
5255 * The following function updates them in a safe manner without read side
5258 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5259 * those fields changing asynchronously (acording the the above rule).
5261 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5262 * outside of boot time (or some other assurance that no concurrent updaters
5265 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5266 unsigned long batch
)
5268 /* start with a fail safe value for batch */
5272 /* Update high, then batch, in order */
5279 /* a companion to pageset_set_high() */
5280 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5282 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5285 static void pageset_init(struct per_cpu_pageset
*p
)
5287 struct per_cpu_pages
*pcp
;
5290 memset(p
, 0, sizeof(*p
));
5294 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5295 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5298 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5301 pageset_set_batch(p
, batch
);
5305 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5306 * to the value high for the pageset p.
5308 static void pageset_set_high(struct per_cpu_pageset
*p
,
5311 unsigned long batch
= max(1UL, high
/ 4);
5312 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5313 batch
= PAGE_SHIFT
* 8;
5315 pageset_update(&p
->pcp
, high
, batch
);
5318 static void pageset_set_high_and_batch(struct zone
*zone
,
5319 struct per_cpu_pageset
*pcp
)
5321 if (percpu_pagelist_fraction
)
5322 pageset_set_high(pcp
,
5323 (zone
->managed_pages
/
5324 percpu_pagelist_fraction
));
5326 pageset_set_batch(pcp
, zone_batchsize(zone
));
5329 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5331 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5334 pageset_set_high_and_batch(zone
, pcp
);
5337 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5340 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5341 for_each_possible_cpu(cpu
)
5342 zone_pageset_init(zone
, cpu
);
5346 * Allocate per cpu pagesets and initialize them.
5347 * Before this call only boot pagesets were available.
5349 void __init
setup_per_cpu_pageset(void)
5353 for_each_populated_zone(zone
)
5354 setup_zone_pageset(zone
);
5357 static noinline __init_refok
5358 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
5364 * The per-page waitqueue mechanism uses hashed waitqueues
5367 zone
->wait_table_hash_nr_entries
=
5368 wait_table_hash_nr_entries(zone_size_pages
);
5369 zone
->wait_table_bits
=
5370 wait_table_bits(zone
->wait_table_hash_nr_entries
);
5371 alloc_size
= zone
->wait_table_hash_nr_entries
5372 * sizeof(wait_queue_head_t
);
5374 if (!slab_is_available()) {
5375 zone
->wait_table
= (wait_queue_head_t
*)
5376 memblock_virt_alloc_node_nopanic(
5377 alloc_size
, zone
->zone_pgdat
->node_id
);
5380 * This case means that a zone whose size was 0 gets new memory
5381 * via memory hot-add.
5382 * But it may be the case that a new node was hot-added. In
5383 * this case vmalloc() will not be able to use this new node's
5384 * memory - this wait_table must be initialized to use this new
5385 * node itself as well.
5386 * To use this new node's memory, further consideration will be
5389 zone
->wait_table
= vmalloc(alloc_size
);
5391 if (!zone
->wait_table
)
5394 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
5395 init_waitqueue_head(zone
->wait_table
+ i
);
5400 static __meminit
void zone_pcp_init(struct zone
*zone
)
5403 * per cpu subsystem is not up at this point. The following code
5404 * relies on the ability of the linker to provide the
5405 * offset of a (static) per cpu variable into the per cpu area.
5407 zone
->pageset
= &boot_pageset
;
5409 if (populated_zone(zone
))
5410 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5411 zone
->name
, zone
->present_pages
,
5412 zone_batchsize(zone
));
5415 int __meminit
init_currently_empty_zone(struct zone
*zone
,
5416 unsigned long zone_start_pfn
,
5419 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5421 ret
= zone_wait_table_init(zone
, size
);
5424 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5426 zone
->zone_start_pfn
= zone_start_pfn
;
5428 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5429 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5431 (unsigned long)zone_idx(zone
),
5432 zone_start_pfn
, (zone_start_pfn
+ size
));
5434 zone_init_free_lists(zone
);
5439 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5440 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5443 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5445 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5446 struct mminit_pfnnid_cache
*state
)
5448 unsigned long start_pfn
, end_pfn
;
5451 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5452 return state
->last_nid
;
5454 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5456 state
->last_start
= start_pfn
;
5457 state
->last_end
= end_pfn
;
5458 state
->last_nid
= nid
;
5463 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5466 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5467 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5468 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5470 * If an architecture guarantees that all ranges registered contain no holes
5471 * and may be freed, this this function may be used instead of calling
5472 * memblock_free_early_nid() manually.
5474 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5476 unsigned long start_pfn
, end_pfn
;
5479 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5480 start_pfn
= min(start_pfn
, max_low_pfn
);
5481 end_pfn
= min(end_pfn
, max_low_pfn
);
5483 if (start_pfn
< end_pfn
)
5484 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5485 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5491 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5492 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5494 * If an architecture guarantees that all ranges registered contain no holes and may
5495 * be freed, this function may be used instead of calling memory_present() manually.
5497 void __init
sparse_memory_present_with_active_regions(int nid
)
5499 unsigned long start_pfn
, end_pfn
;
5502 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5503 memory_present(this_nid
, start_pfn
, end_pfn
);
5507 * get_pfn_range_for_nid - Return the start and end page frames for a node
5508 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5509 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5510 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5512 * It returns the start and end page frame of a node based on information
5513 * provided by memblock_set_node(). If called for a node
5514 * with no available memory, a warning is printed and the start and end
5517 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5518 unsigned long *start_pfn
, unsigned long *end_pfn
)
5520 unsigned long this_start_pfn
, this_end_pfn
;
5526 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5527 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5528 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5531 if (*start_pfn
== -1UL)
5536 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5537 * assumption is made that zones within a node are ordered in monotonic
5538 * increasing memory addresses so that the "highest" populated zone is used
5540 static void __init
find_usable_zone_for_movable(void)
5543 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5544 if (zone_index
== ZONE_MOVABLE
)
5547 if (arch_zone_highest_possible_pfn
[zone_index
] >
5548 arch_zone_lowest_possible_pfn
[zone_index
])
5552 VM_BUG_ON(zone_index
== -1);
5553 movable_zone
= zone_index
;
5557 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5558 * because it is sized independent of architecture. Unlike the other zones,
5559 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5560 * in each node depending on the size of each node and how evenly kernelcore
5561 * is distributed. This helper function adjusts the zone ranges
5562 * provided by the architecture for a given node by using the end of the
5563 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5564 * zones within a node are in order of monotonic increases memory addresses
5566 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5567 unsigned long zone_type
,
5568 unsigned long node_start_pfn
,
5569 unsigned long node_end_pfn
,
5570 unsigned long *zone_start_pfn
,
5571 unsigned long *zone_end_pfn
)
5573 /* Only adjust if ZONE_MOVABLE is on this node */
5574 if (zone_movable_pfn
[nid
]) {
5575 /* Size ZONE_MOVABLE */
5576 if (zone_type
== ZONE_MOVABLE
) {
5577 *zone_start_pfn
= zone_movable_pfn
[nid
];
5578 *zone_end_pfn
= min(node_end_pfn
,
5579 arch_zone_highest_possible_pfn
[movable_zone
]);
5581 /* Check if this whole range is within ZONE_MOVABLE */
5582 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5583 *zone_start_pfn
= *zone_end_pfn
;
5588 * Return the number of pages a zone spans in a node, including holes
5589 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5591 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5592 unsigned long zone_type
,
5593 unsigned long node_start_pfn
,
5594 unsigned long node_end_pfn
,
5595 unsigned long *zone_start_pfn
,
5596 unsigned long *zone_end_pfn
,
5597 unsigned long *ignored
)
5599 /* When hotadd a new node from cpu_up(), the node should be empty */
5600 if (!node_start_pfn
&& !node_end_pfn
)
5603 /* Get the start and end of the zone */
5604 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5605 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5606 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5607 node_start_pfn
, node_end_pfn
,
5608 zone_start_pfn
, zone_end_pfn
);
5610 /* Check that this node has pages within the zone's required range */
5611 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5614 /* Move the zone boundaries inside the node if necessary */
5615 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5616 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5618 /* Return the spanned pages */
5619 return *zone_end_pfn
- *zone_start_pfn
;
5623 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5624 * then all holes in the requested range will be accounted for.
5626 unsigned long __meminit
__absent_pages_in_range(int nid
,
5627 unsigned long range_start_pfn
,
5628 unsigned long range_end_pfn
)
5630 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5631 unsigned long start_pfn
, end_pfn
;
5634 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5635 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5636 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5637 nr_absent
-= end_pfn
- start_pfn
;
5643 * absent_pages_in_range - Return number of page frames in holes within a range
5644 * @start_pfn: The start PFN to start searching for holes
5645 * @end_pfn: The end PFN to stop searching for holes
5647 * It returns the number of pages frames in memory holes within a range.
5649 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5650 unsigned long end_pfn
)
5652 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5655 /* Return the number of page frames in holes in a zone on a node */
5656 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5657 unsigned long zone_type
,
5658 unsigned long node_start_pfn
,
5659 unsigned long node_end_pfn
,
5660 unsigned long *ignored
)
5662 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5663 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5664 unsigned long zone_start_pfn
, zone_end_pfn
;
5665 unsigned long nr_absent
;
5667 /* When hotadd a new node from cpu_up(), the node should be empty */
5668 if (!node_start_pfn
&& !node_end_pfn
)
5671 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5672 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5674 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5675 node_start_pfn
, node_end_pfn
,
5676 &zone_start_pfn
, &zone_end_pfn
);
5677 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5680 * ZONE_MOVABLE handling.
5681 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5684 if (zone_movable_pfn
[nid
]) {
5685 if (mirrored_kernelcore
) {
5686 unsigned long start_pfn
, end_pfn
;
5687 struct memblock_region
*r
;
5689 for_each_memblock(memory
, r
) {
5690 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5691 zone_start_pfn
, zone_end_pfn
);
5692 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5693 zone_start_pfn
, zone_end_pfn
);
5695 if (zone_type
== ZONE_MOVABLE
&&
5696 memblock_is_mirror(r
))
5697 nr_absent
+= end_pfn
- start_pfn
;
5699 if (zone_type
== ZONE_NORMAL
&&
5700 !memblock_is_mirror(r
))
5701 nr_absent
+= end_pfn
- start_pfn
;
5704 if (zone_type
== ZONE_NORMAL
)
5705 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5712 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5713 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5714 unsigned long zone_type
,
5715 unsigned long node_start_pfn
,
5716 unsigned long node_end_pfn
,
5717 unsigned long *zone_start_pfn
,
5718 unsigned long *zone_end_pfn
,
5719 unsigned long *zones_size
)
5723 *zone_start_pfn
= node_start_pfn
;
5724 for (zone
= 0; zone
< zone_type
; zone
++)
5725 *zone_start_pfn
+= zones_size
[zone
];
5727 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5729 return zones_size
[zone_type
];
5732 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5733 unsigned long zone_type
,
5734 unsigned long node_start_pfn
,
5735 unsigned long node_end_pfn
,
5736 unsigned long *zholes_size
)
5741 return zholes_size
[zone_type
];
5744 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5746 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5747 unsigned long node_start_pfn
,
5748 unsigned long node_end_pfn
,
5749 unsigned long *zones_size
,
5750 unsigned long *zholes_size
)
5752 unsigned long realtotalpages
= 0, totalpages
= 0;
5755 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5756 struct zone
*zone
= pgdat
->node_zones
+ i
;
5757 unsigned long zone_start_pfn
, zone_end_pfn
;
5758 unsigned long size
, real_size
;
5760 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5766 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5767 node_start_pfn
, node_end_pfn
,
5770 zone
->zone_start_pfn
= zone_start_pfn
;
5772 zone
->zone_start_pfn
= 0;
5773 zone
->spanned_pages
= size
;
5774 zone
->present_pages
= real_size
;
5777 realtotalpages
+= real_size
;
5780 pgdat
->node_spanned_pages
= totalpages
;
5781 pgdat
->node_present_pages
= realtotalpages
;
5782 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5786 #ifndef CONFIG_SPARSEMEM
5788 * Calculate the size of the zone->blockflags rounded to an unsigned long
5789 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5790 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5791 * round what is now in bits to nearest long in bits, then return it in
5794 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5796 unsigned long usemapsize
;
5798 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5799 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5800 usemapsize
= usemapsize
>> pageblock_order
;
5801 usemapsize
*= NR_PAGEBLOCK_BITS
;
5802 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5804 return usemapsize
/ 8;
5807 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5809 unsigned long zone_start_pfn
,
5810 unsigned long zonesize
)
5812 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5813 zone
->pageblock_flags
= NULL
;
5815 zone
->pageblock_flags
=
5816 memblock_virt_alloc_node_nopanic(usemapsize
,
5820 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5821 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5822 #endif /* CONFIG_SPARSEMEM */
5824 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5826 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5827 void __paginginit
set_pageblock_order(void)
5831 /* Check that pageblock_nr_pages has not already been setup */
5832 if (pageblock_order
)
5835 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5836 order
= HUGETLB_PAGE_ORDER
;
5838 order
= MAX_ORDER
- 1;
5841 * Assume the largest contiguous order of interest is a huge page.
5842 * This value may be variable depending on boot parameters on IA64 and
5845 pageblock_order
= order
;
5847 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5850 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5851 * is unused as pageblock_order is set at compile-time. See
5852 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5855 void __paginginit
set_pageblock_order(void)
5859 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5861 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5862 unsigned long present_pages
)
5864 unsigned long pages
= spanned_pages
;
5867 * Provide a more accurate estimation if there are holes within
5868 * the zone and SPARSEMEM is in use. If there are holes within the
5869 * zone, each populated memory region may cost us one or two extra
5870 * memmap pages due to alignment because memmap pages for each
5871 * populated regions may not naturally algined on page boundary.
5872 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5874 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5875 IS_ENABLED(CONFIG_SPARSEMEM
))
5876 pages
= present_pages
;
5878 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5882 * Set up the zone data structures:
5883 * - mark all pages reserved
5884 * - mark all memory queues empty
5885 * - clear the memory bitmaps
5887 * NOTE: pgdat should get zeroed by caller.
5889 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5892 int nid
= pgdat
->node_id
;
5895 pgdat_resize_init(pgdat
);
5896 #ifdef CONFIG_NUMA_BALANCING
5897 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5898 pgdat
->numabalancing_migrate_nr_pages
= 0;
5899 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5901 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5902 spin_lock_init(&pgdat
->split_queue_lock
);
5903 INIT_LIST_HEAD(&pgdat
->split_queue
);
5904 pgdat
->split_queue_len
= 0;
5906 init_waitqueue_head(&pgdat
->kswapd_wait
);
5907 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5908 #ifdef CONFIG_COMPACTION
5909 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5911 pgdat_page_ext_init(pgdat
);
5913 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5914 struct zone
*zone
= pgdat
->node_zones
+ j
;
5915 unsigned long size
, realsize
, freesize
, memmap_pages
;
5916 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5918 size
= zone
->spanned_pages
;
5919 realsize
= freesize
= zone
->present_pages
;
5922 * Adjust freesize so that it accounts for how much memory
5923 * is used by this zone for memmap. This affects the watermark
5924 * and per-cpu initialisations
5926 memmap_pages
= calc_memmap_size(size
, realsize
);
5927 if (!is_highmem_idx(j
)) {
5928 if (freesize
>= memmap_pages
) {
5929 freesize
-= memmap_pages
;
5932 " %s zone: %lu pages used for memmap\n",
5933 zone_names
[j
], memmap_pages
);
5935 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5936 zone_names
[j
], memmap_pages
, freesize
);
5939 /* Account for reserved pages */
5940 if (j
== 0 && freesize
> dma_reserve
) {
5941 freesize
-= dma_reserve
;
5942 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5943 zone_names
[0], dma_reserve
);
5946 if (!is_highmem_idx(j
))
5947 nr_kernel_pages
+= freesize
;
5948 /* Charge for highmem memmap if there are enough kernel pages */
5949 else if (nr_kernel_pages
> memmap_pages
* 2)
5950 nr_kernel_pages
-= memmap_pages
;
5951 nr_all_pages
+= freesize
;
5954 * Set an approximate value for lowmem here, it will be adjusted
5955 * when the bootmem allocator frees pages into the buddy system.
5956 * And all highmem pages will be managed by the buddy system.
5958 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5961 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5963 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5965 zone
->name
= zone_names
[j
];
5966 spin_lock_init(&zone
->lock
);
5967 spin_lock_init(&zone
->lru_lock
);
5968 zone_seqlock_init(zone
);
5969 zone
->zone_pgdat
= pgdat
;
5970 zone_pcp_init(zone
);
5972 /* For bootup, initialized properly in watermark setup */
5973 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5975 lruvec_init(&zone
->lruvec
);
5979 set_pageblock_order();
5980 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5981 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5983 memmap_init(size
, nid
, j
, zone_start_pfn
);
5987 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5989 unsigned long __maybe_unused start
= 0;
5990 unsigned long __maybe_unused offset
= 0;
5992 /* Skip empty nodes */
5993 if (!pgdat
->node_spanned_pages
)
5996 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5997 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5998 offset
= pgdat
->node_start_pfn
- start
;
5999 /* ia64 gets its own node_mem_map, before this, without bootmem */
6000 if (!pgdat
->node_mem_map
) {
6001 unsigned long size
, end
;
6005 * The zone's endpoints aren't required to be MAX_ORDER
6006 * aligned but the node_mem_map endpoints must be in order
6007 * for the buddy allocator to function correctly.
6009 end
= pgdat_end_pfn(pgdat
);
6010 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6011 size
= (end
- start
) * sizeof(struct page
);
6012 map
= alloc_remap(pgdat
->node_id
, size
);
6014 map
= memblock_virt_alloc_node_nopanic(size
,
6016 pgdat
->node_mem_map
= map
+ offset
;
6018 #ifndef CONFIG_NEED_MULTIPLE_NODES
6020 * With no DISCONTIG, the global mem_map is just set as node 0's
6022 if (pgdat
== NODE_DATA(0)) {
6023 mem_map
= NODE_DATA(0)->node_mem_map
;
6024 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6025 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6027 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6030 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6033 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6034 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6036 pg_data_t
*pgdat
= NODE_DATA(nid
);
6037 unsigned long start_pfn
= 0;
6038 unsigned long end_pfn
= 0;
6040 /* pg_data_t should be reset to zero when it's allocated */
6041 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
6043 reset_deferred_meminit(pgdat
);
6044 pgdat
->node_id
= nid
;
6045 pgdat
->node_start_pfn
= node_start_pfn
;
6046 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6047 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6048 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6049 (u64
)start_pfn
<< PAGE_SHIFT
,
6050 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6052 start_pfn
= node_start_pfn
;
6054 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6055 zones_size
, zholes_size
);
6057 alloc_node_mem_map(pgdat
);
6058 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6059 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6060 nid
, (unsigned long)pgdat
,
6061 (unsigned long)pgdat
->node_mem_map
);
6064 free_area_init_core(pgdat
);
6067 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6069 #if MAX_NUMNODES > 1
6071 * Figure out the number of possible node ids.
6073 void __init
setup_nr_node_ids(void)
6075 unsigned int highest
;
6077 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6078 nr_node_ids
= highest
+ 1;
6083 * node_map_pfn_alignment - determine the maximum internode alignment
6085 * This function should be called after node map is populated and sorted.
6086 * It calculates the maximum power of two alignment which can distinguish
6089 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6090 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6091 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6092 * shifted, 1GiB is enough and this function will indicate so.
6094 * This is used to test whether pfn -> nid mapping of the chosen memory
6095 * model has fine enough granularity to avoid incorrect mapping for the
6096 * populated node map.
6098 * Returns the determined alignment in pfn's. 0 if there is no alignment
6099 * requirement (single node).
6101 unsigned long __init
node_map_pfn_alignment(void)
6103 unsigned long accl_mask
= 0, last_end
= 0;
6104 unsigned long start
, end
, mask
;
6108 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6109 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6116 * Start with a mask granular enough to pin-point to the
6117 * start pfn and tick off bits one-by-one until it becomes
6118 * too coarse to separate the current node from the last.
6120 mask
= ~((1 << __ffs(start
)) - 1);
6121 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6124 /* accumulate all internode masks */
6128 /* convert mask to number of pages */
6129 return ~accl_mask
+ 1;
6132 /* Find the lowest pfn for a node */
6133 static unsigned long __init
find_min_pfn_for_node(int nid
)
6135 unsigned long min_pfn
= ULONG_MAX
;
6136 unsigned long start_pfn
;
6139 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6140 min_pfn
= min(min_pfn
, start_pfn
);
6142 if (min_pfn
== ULONG_MAX
) {
6143 pr_warn("Could not find start_pfn for node %d\n", nid
);
6151 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6153 * It returns the minimum PFN based on information provided via
6154 * memblock_set_node().
6156 unsigned long __init
find_min_pfn_with_active_regions(void)
6158 return find_min_pfn_for_node(MAX_NUMNODES
);
6162 * early_calculate_totalpages()
6163 * Sum pages in active regions for movable zone.
6164 * Populate N_MEMORY for calculating usable_nodes.
6166 static unsigned long __init
early_calculate_totalpages(void)
6168 unsigned long totalpages
= 0;
6169 unsigned long start_pfn
, end_pfn
;
6172 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6173 unsigned long pages
= end_pfn
- start_pfn
;
6175 totalpages
+= pages
;
6177 node_set_state(nid
, N_MEMORY
);
6183 * Find the PFN the Movable zone begins in each node. Kernel memory
6184 * is spread evenly between nodes as long as the nodes have enough
6185 * memory. When they don't, some nodes will have more kernelcore than
6188 static void __init
find_zone_movable_pfns_for_nodes(void)
6191 unsigned long usable_startpfn
;
6192 unsigned long kernelcore_node
, kernelcore_remaining
;
6193 /* save the state before borrow the nodemask */
6194 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6195 unsigned long totalpages
= early_calculate_totalpages();
6196 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6197 struct memblock_region
*r
;
6199 /* Need to find movable_zone earlier when movable_node is specified. */
6200 find_usable_zone_for_movable();
6203 * If movable_node is specified, ignore kernelcore and movablecore
6206 if (movable_node_is_enabled()) {
6207 for_each_memblock(memory
, r
) {
6208 if (!memblock_is_hotpluggable(r
))
6213 usable_startpfn
= PFN_DOWN(r
->base
);
6214 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6215 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6223 * If kernelcore=mirror is specified, ignore movablecore option
6225 if (mirrored_kernelcore
) {
6226 bool mem_below_4gb_not_mirrored
= false;
6228 for_each_memblock(memory
, r
) {
6229 if (memblock_is_mirror(r
))
6234 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6236 if (usable_startpfn
< 0x100000) {
6237 mem_below_4gb_not_mirrored
= true;
6241 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6242 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6246 if (mem_below_4gb_not_mirrored
)
6247 pr_warn("This configuration results in unmirrored kernel memory.");
6253 * If movablecore=nn[KMG] was specified, calculate what size of
6254 * kernelcore that corresponds so that memory usable for
6255 * any allocation type is evenly spread. If both kernelcore
6256 * and movablecore are specified, then the value of kernelcore
6257 * will be used for required_kernelcore if it's greater than
6258 * what movablecore would have allowed.
6260 if (required_movablecore
) {
6261 unsigned long corepages
;
6264 * Round-up so that ZONE_MOVABLE is at least as large as what
6265 * was requested by the user
6267 required_movablecore
=
6268 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6269 required_movablecore
= min(totalpages
, required_movablecore
);
6270 corepages
= totalpages
- required_movablecore
;
6272 required_kernelcore
= max(required_kernelcore
, corepages
);
6276 * If kernelcore was not specified or kernelcore size is larger
6277 * than totalpages, there is no ZONE_MOVABLE.
6279 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6282 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6283 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6286 /* Spread kernelcore memory as evenly as possible throughout nodes */
6287 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6288 for_each_node_state(nid
, N_MEMORY
) {
6289 unsigned long start_pfn
, end_pfn
;
6292 * Recalculate kernelcore_node if the division per node
6293 * now exceeds what is necessary to satisfy the requested
6294 * amount of memory for the kernel
6296 if (required_kernelcore
< kernelcore_node
)
6297 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6300 * As the map is walked, we track how much memory is usable
6301 * by the kernel using kernelcore_remaining. When it is
6302 * 0, the rest of the node is usable by ZONE_MOVABLE
6304 kernelcore_remaining
= kernelcore_node
;
6306 /* Go through each range of PFNs within this node */
6307 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6308 unsigned long size_pages
;
6310 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6311 if (start_pfn
>= end_pfn
)
6314 /* Account for what is only usable for kernelcore */
6315 if (start_pfn
< usable_startpfn
) {
6316 unsigned long kernel_pages
;
6317 kernel_pages
= min(end_pfn
, usable_startpfn
)
6320 kernelcore_remaining
-= min(kernel_pages
,
6321 kernelcore_remaining
);
6322 required_kernelcore
-= min(kernel_pages
,
6323 required_kernelcore
);
6325 /* Continue if range is now fully accounted */
6326 if (end_pfn
<= usable_startpfn
) {
6329 * Push zone_movable_pfn to the end so
6330 * that if we have to rebalance
6331 * kernelcore across nodes, we will
6332 * not double account here
6334 zone_movable_pfn
[nid
] = end_pfn
;
6337 start_pfn
= usable_startpfn
;
6341 * The usable PFN range for ZONE_MOVABLE is from
6342 * start_pfn->end_pfn. Calculate size_pages as the
6343 * number of pages used as kernelcore
6345 size_pages
= end_pfn
- start_pfn
;
6346 if (size_pages
> kernelcore_remaining
)
6347 size_pages
= kernelcore_remaining
;
6348 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6351 * Some kernelcore has been met, update counts and
6352 * break if the kernelcore for this node has been
6355 required_kernelcore
-= min(required_kernelcore
,
6357 kernelcore_remaining
-= size_pages
;
6358 if (!kernelcore_remaining
)
6364 * If there is still required_kernelcore, we do another pass with one
6365 * less node in the count. This will push zone_movable_pfn[nid] further
6366 * along on the nodes that still have memory until kernelcore is
6370 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6374 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6375 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6376 zone_movable_pfn
[nid
] =
6377 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6380 /* restore the node_state */
6381 node_states
[N_MEMORY
] = saved_node_state
;
6384 /* Any regular or high memory on that node ? */
6385 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6387 enum zone_type zone_type
;
6389 if (N_MEMORY
== N_NORMAL_MEMORY
)
6392 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6393 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6394 if (populated_zone(zone
)) {
6395 node_set_state(nid
, N_HIGH_MEMORY
);
6396 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6397 zone_type
<= ZONE_NORMAL
)
6398 node_set_state(nid
, N_NORMAL_MEMORY
);
6405 * free_area_init_nodes - Initialise all pg_data_t and zone data
6406 * @max_zone_pfn: an array of max PFNs for each zone
6408 * This will call free_area_init_node() for each active node in the system.
6409 * Using the page ranges provided by memblock_set_node(), the size of each
6410 * zone in each node and their holes is calculated. If the maximum PFN
6411 * between two adjacent zones match, it is assumed that the zone is empty.
6412 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6413 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6414 * starts where the previous one ended. For example, ZONE_DMA32 starts
6415 * at arch_max_dma_pfn.
6417 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6419 unsigned long start_pfn
, end_pfn
;
6422 /* Record where the zone boundaries are */
6423 memset(arch_zone_lowest_possible_pfn
, 0,
6424 sizeof(arch_zone_lowest_possible_pfn
));
6425 memset(arch_zone_highest_possible_pfn
, 0,
6426 sizeof(arch_zone_highest_possible_pfn
));
6428 start_pfn
= find_min_pfn_with_active_regions();
6430 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6431 if (i
== ZONE_MOVABLE
)
6434 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6435 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6436 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6438 start_pfn
= end_pfn
;
6440 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
6441 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
6443 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6444 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6445 find_zone_movable_pfns_for_nodes();
6447 /* Print out the zone ranges */
6448 pr_info("Zone ranges:\n");
6449 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6450 if (i
== ZONE_MOVABLE
)
6452 pr_info(" %-8s ", zone_names
[i
]);
6453 if (arch_zone_lowest_possible_pfn
[i
] ==
6454 arch_zone_highest_possible_pfn
[i
])
6457 pr_cont("[mem %#018Lx-%#018Lx]\n",
6458 (u64
)arch_zone_lowest_possible_pfn
[i
]
6460 ((u64
)arch_zone_highest_possible_pfn
[i
]
6461 << PAGE_SHIFT
) - 1);
6464 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6465 pr_info("Movable zone start for each node\n");
6466 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6467 if (zone_movable_pfn
[i
])
6468 pr_info(" Node %d: %#018Lx\n", i
,
6469 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6472 /* Print out the early node map */
6473 pr_info("Early memory node ranges\n");
6474 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6475 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6476 (u64
)start_pfn
<< PAGE_SHIFT
,
6477 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6479 /* Initialise every node */
6480 mminit_verify_pageflags_layout();
6481 setup_nr_node_ids();
6482 for_each_online_node(nid
) {
6483 pg_data_t
*pgdat
= NODE_DATA(nid
);
6484 free_area_init_node(nid
, NULL
,
6485 find_min_pfn_for_node(nid
), NULL
);
6487 /* Any memory on that node */
6488 if (pgdat
->node_present_pages
)
6489 node_set_state(nid
, N_MEMORY
);
6490 check_for_memory(pgdat
, nid
);
6494 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6496 unsigned long long coremem
;
6500 coremem
= memparse(p
, &p
);
6501 *core
= coremem
>> PAGE_SHIFT
;
6503 /* Paranoid check that UL is enough for the coremem value */
6504 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6510 * kernelcore=size sets the amount of memory for use for allocations that
6511 * cannot be reclaimed or migrated.
6513 static int __init
cmdline_parse_kernelcore(char *p
)
6515 /* parse kernelcore=mirror */
6516 if (parse_option_str(p
, "mirror")) {
6517 mirrored_kernelcore
= true;
6521 return cmdline_parse_core(p
, &required_kernelcore
);
6525 * movablecore=size sets the amount of memory for use for allocations that
6526 * can be reclaimed or migrated.
6528 static int __init
cmdline_parse_movablecore(char *p
)
6530 return cmdline_parse_core(p
, &required_movablecore
);
6533 early_param("kernelcore", cmdline_parse_kernelcore
);
6534 early_param("movablecore", cmdline_parse_movablecore
);
6536 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6538 void adjust_managed_page_count(struct page
*page
, long count
)
6540 spin_lock(&managed_page_count_lock
);
6541 page_zone(page
)->managed_pages
+= count
;
6542 totalram_pages
+= count
;
6543 #ifdef CONFIG_HIGHMEM
6544 if (PageHighMem(page
))
6545 totalhigh_pages
+= count
;
6547 spin_unlock(&managed_page_count_lock
);
6549 EXPORT_SYMBOL(adjust_managed_page_count
);
6551 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6554 unsigned long pages
= 0;
6556 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6557 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6558 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6559 if ((unsigned int)poison
<= 0xFF)
6560 memset(pos
, poison
, PAGE_SIZE
);
6561 free_reserved_page(virt_to_page(pos
));
6565 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6566 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6570 EXPORT_SYMBOL(free_reserved_area
);
6572 #ifdef CONFIG_HIGHMEM
6573 void free_highmem_page(struct page
*page
)
6575 __free_reserved_page(page
);
6577 page_zone(page
)->managed_pages
++;
6583 void __init
mem_init_print_info(const char *str
)
6585 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6586 unsigned long init_code_size
, init_data_size
;
6588 physpages
= get_num_physpages();
6589 codesize
= _etext
- _stext
;
6590 datasize
= _edata
- _sdata
;
6591 rosize
= __end_rodata
- __start_rodata
;
6592 bss_size
= __bss_stop
- __bss_start
;
6593 init_data_size
= __init_end
- __init_begin
;
6594 init_code_size
= _einittext
- _sinittext
;
6597 * Detect special cases and adjust section sizes accordingly:
6598 * 1) .init.* may be embedded into .data sections
6599 * 2) .init.text.* may be out of [__init_begin, __init_end],
6600 * please refer to arch/tile/kernel/vmlinux.lds.S.
6601 * 3) .rodata.* may be embedded into .text or .data sections.
6603 #define adj_init_size(start, end, size, pos, adj) \
6605 if (start <= pos && pos < end && size > adj) \
6609 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6610 _sinittext
, init_code_size
);
6611 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6612 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6613 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6614 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6616 #undef adj_init_size
6618 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6619 #ifdef CONFIG_HIGHMEM
6623 nr_free_pages() << (PAGE_SHIFT
- 10),
6624 physpages
<< (PAGE_SHIFT
- 10),
6625 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6626 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6627 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6628 totalcma_pages
<< (PAGE_SHIFT
- 10),
6629 #ifdef CONFIG_HIGHMEM
6630 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6632 str
? ", " : "", str
? str
: "");
6636 * set_dma_reserve - set the specified number of pages reserved in the first zone
6637 * @new_dma_reserve: The number of pages to mark reserved
6639 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6640 * In the DMA zone, a significant percentage may be consumed by kernel image
6641 * and other unfreeable allocations which can skew the watermarks badly. This
6642 * function may optionally be used to account for unfreeable pages in the
6643 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6644 * smaller per-cpu batchsize.
6646 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6648 dma_reserve
= new_dma_reserve
;
6651 void __init
free_area_init(unsigned long *zones_size
)
6653 free_area_init_node(0, zones_size
,
6654 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6657 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6658 unsigned long action
, void *hcpu
)
6660 int cpu
= (unsigned long)hcpu
;
6662 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6663 lru_add_drain_cpu(cpu
);
6667 * Spill the event counters of the dead processor
6668 * into the current processors event counters.
6669 * This artificially elevates the count of the current
6672 vm_events_fold_cpu(cpu
);
6675 * Zero the differential counters of the dead processor
6676 * so that the vm statistics are consistent.
6678 * This is only okay since the processor is dead and cannot
6679 * race with what we are doing.
6681 cpu_vm_stats_fold(cpu
);
6686 void __init
page_alloc_init(void)
6688 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6692 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6693 * or min_free_kbytes changes.
6695 static void calculate_totalreserve_pages(void)
6697 struct pglist_data
*pgdat
;
6698 unsigned long reserve_pages
= 0;
6699 enum zone_type i
, j
;
6701 for_each_online_pgdat(pgdat
) {
6702 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6703 struct zone
*zone
= pgdat
->node_zones
+ i
;
6706 /* Find valid and maximum lowmem_reserve in the zone */
6707 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6708 if (zone
->lowmem_reserve
[j
] > max
)
6709 max
= zone
->lowmem_reserve
[j
];
6712 /* we treat the high watermark as reserved pages. */
6713 max
+= high_wmark_pages(zone
);
6715 if (max
> zone
->managed_pages
)
6716 max
= zone
->managed_pages
;
6718 zone
->totalreserve_pages
= max
;
6720 reserve_pages
+= max
;
6723 totalreserve_pages
= reserve_pages
;
6727 * setup_per_zone_lowmem_reserve - called whenever
6728 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6729 * has a correct pages reserved value, so an adequate number of
6730 * pages are left in the zone after a successful __alloc_pages().
6732 static void setup_per_zone_lowmem_reserve(void)
6734 struct pglist_data
*pgdat
;
6735 enum zone_type j
, idx
;
6737 for_each_online_pgdat(pgdat
) {
6738 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6739 struct zone
*zone
= pgdat
->node_zones
+ j
;
6740 unsigned long managed_pages
= zone
->managed_pages
;
6742 zone
->lowmem_reserve
[j
] = 0;
6746 struct zone
*lower_zone
;
6750 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6751 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6753 lower_zone
= pgdat
->node_zones
+ idx
;
6754 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6755 sysctl_lowmem_reserve_ratio
[idx
];
6756 managed_pages
+= lower_zone
->managed_pages
;
6761 /* update totalreserve_pages */
6762 calculate_totalreserve_pages();
6765 static void __setup_per_zone_wmarks(void)
6767 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6768 unsigned long lowmem_pages
= 0;
6770 unsigned long flags
;
6772 /* Calculate total number of !ZONE_HIGHMEM pages */
6773 for_each_zone(zone
) {
6774 if (!is_highmem(zone
))
6775 lowmem_pages
+= zone
->managed_pages
;
6778 for_each_zone(zone
) {
6781 spin_lock_irqsave(&zone
->lock
, flags
);
6782 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6783 do_div(tmp
, lowmem_pages
);
6784 if (is_highmem(zone
)) {
6786 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6787 * need highmem pages, so cap pages_min to a small
6790 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6791 * deltas control asynch page reclaim, and so should
6792 * not be capped for highmem.
6794 unsigned long min_pages
;
6796 min_pages
= zone
->managed_pages
/ 1024;
6797 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6798 zone
->watermark
[WMARK_MIN
] = min_pages
;
6801 * If it's a lowmem zone, reserve a number of pages
6802 * proportionate to the zone's size.
6804 zone
->watermark
[WMARK_MIN
] = tmp
;
6808 * Set the kswapd watermarks distance according to the
6809 * scale factor in proportion to available memory, but
6810 * ensure a minimum size on small systems.
6812 tmp
= max_t(u64
, tmp
>> 2,
6813 mult_frac(zone
->managed_pages
,
6814 watermark_scale_factor
, 10000));
6816 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6817 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6819 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6820 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6821 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6823 spin_unlock_irqrestore(&zone
->lock
, flags
);
6826 /* update totalreserve_pages */
6827 calculate_totalreserve_pages();
6831 * setup_per_zone_wmarks - called when min_free_kbytes changes
6832 * or when memory is hot-{added|removed}
6834 * Ensures that the watermark[min,low,high] values for each zone are set
6835 * correctly with respect to min_free_kbytes.
6837 void setup_per_zone_wmarks(void)
6839 mutex_lock(&zonelists_mutex
);
6840 __setup_per_zone_wmarks();
6841 mutex_unlock(&zonelists_mutex
);
6845 * Initialise min_free_kbytes.
6847 * For small machines we want it small (128k min). For large machines
6848 * we want it large (64MB max). But it is not linear, because network
6849 * bandwidth does not increase linearly with machine size. We use
6851 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6852 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6868 int __meminit
init_per_zone_wmark_min(void)
6870 unsigned long lowmem_kbytes
;
6871 int new_min_free_kbytes
;
6873 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6874 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6876 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6877 min_free_kbytes
= new_min_free_kbytes
;
6878 if (min_free_kbytes
< 128)
6879 min_free_kbytes
= 128;
6880 if (min_free_kbytes
> 65536)
6881 min_free_kbytes
= 65536;
6883 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6884 new_min_free_kbytes
, user_min_free_kbytes
);
6886 setup_per_zone_wmarks();
6887 refresh_zone_stat_thresholds();
6888 setup_per_zone_lowmem_reserve();
6891 core_initcall(init_per_zone_wmark_min
)
6894 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6895 * that we can call two helper functions whenever min_free_kbytes
6898 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6899 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6903 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6908 user_min_free_kbytes
= min_free_kbytes
;
6909 setup_per_zone_wmarks();
6914 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6915 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6919 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6924 setup_per_zone_wmarks();
6930 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6931 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6936 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6941 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6942 sysctl_min_unmapped_ratio
) / 100;
6946 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6947 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6952 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6957 zone
->min_slab_pages
= (zone
->managed_pages
*
6958 sysctl_min_slab_ratio
) / 100;
6964 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6965 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6966 * whenever sysctl_lowmem_reserve_ratio changes.
6968 * The reserve ratio obviously has absolutely no relation with the
6969 * minimum watermarks. The lowmem reserve ratio can only make sense
6970 * if in function of the boot time zone sizes.
6972 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6973 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6975 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6976 setup_per_zone_lowmem_reserve();
6981 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6982 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6983 * pagelist can have before it gets flushed back to buddy allocator.
6985 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6986 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6989 int old_percpu_pagelist_fraction
;
6992 mutex_lock(&pcp_batch_high_lock
);
6993 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6995 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6996 if (!write
|| ret
< 0)
6999 /* Sanity checking to avoid pcp imbalance */
7000 if (percpu_pagelist_fraction
&&
7001 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7002 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7008 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7011 for_each_populated_zone(zone
) {
7014 for_each_possible_cpu(cpu
)
7015 pageset_set_high_and_batch(zone
,
7016 per_cpu_ptr(zone
->pageset
, cpu
));
7019 mutex_unlock(&pcp_batch_high_lock
);
7024 int hashdist
= HASHDIST_DEFAULT
;
7026 static int __init
set_hashdist(char *str
)
7030 hashdist
= simple_strtoul(str
, &str
, 0);
7033 __setup("hashdist=", set_hashdist
);
7037 * allocate a large system hash table from bootmem
7038 * - it is assumed that the hash table must contain an exact power-of-2
7039 * quantity of entries
7040 * - limit is the number of hash buckets, not the total allocation size
7042 void *__init
alloc_large_system_hash(const char *tablename
,
7043 unsigned long bucketsize
,
7044 unsigned long numentries
,
7047 unsigned int *_hash_shift
,
7048 unsigned int *_hash_mask
,
7049 unsigned long low_limit
,
7050 unsigned long high_limit
)
7052 unsigned long long max
= high_limit
;
7053 unsigned long log2qty
, size
;
7056 /* allow the kernel cmdline to have a say */
7058 /* round applicable memory size up to nearest megabyte */
7059 numentries
= nr_kernel_pages
;
7061 /* It isn't necessary when PAGE_SIZE >= 1MB */
7062 if (PAGE_SHIFT
< 20)
7063 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7065 /* limit to 1 bucket per 2^scale bytes of low memory */
7066 if (scale
> PAGE_SHIFT
)
7067 numentries
>>= (scale
- PAGE_SHIFT
);
7069 numentries
<<= (PAGE_SHIFT
- scale
);
7071 /* Make sure we've got at least a 0-order allocation.. */
7072 if (unlikely(flags
& HASH_SMALL
)) {
7073 /* Makes no sense without HASH_EARLY */
7074 WARN_ON(!(flags
& HASH_EARLY
));
7075 if (!(numentries
>> *_hash_shift
)) {
7076 numentries
= 1UL << *_hash_shift
;
7077 BUG_ON(!numentries
);
7079 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7080 numentries
= PAGE_SIZE
/ bucketsize
;
7082 numentries
= roundup_pow_of_two(numentries
);
7084 /* limit allocation size to 1/16 total memory by default */
7086 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7087 do_div(max
, bucketsize
);
7089 max
= min(max
, 0x80000000ULL
);
7091 if (numentries
< low_limit
)
7092 numentries
= low_limit
;
7093 if (numentries
> max
)
7096 log2qty
= ilog2(numentries
);
7099 size
= bucketsize
<< log2qty
;
7100 if (flags
& HASH_EARLY
)
7101 table
= memblock_virt_alloc_nopanic(size
, 0);
7103 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
7106 * If bucketsize is not a power-of-two, we may free
7107 * some pages at the end of hash table which
7108 * alloc_pages_exact() automatically does
7110 if (get_order(size
) < MAX_ORDER
) {
7111 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
7112 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
7115 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7118 panic("Failed to allocate %s hash table\n", tablename
);
7120 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7121 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7124 *_hash_shift
= log2qty
;
7126 *_hash_mask
= (1 << log2qty
) - 1;
7132 * This function checks whether pageblock includes unmovable pages or not.
7133 * If @count is not zero, it is okay to include less @count unmovable pages
7135 * PageLRU check without isolation or lru_lock could race so that
7136 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7137 * expect this function should be exact.
7139 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7140 bool skip_hwpoisoned_pages
)
7142 unsigned long pfn
, iter
, found
;
7146 * For avoiding noise data, lru_add_drain_all() should be called
7147 * If ZONE_MOVABLE, the zone never contains unmovable pages
7149 if (zone_idx(zone
) == ZONE_MOVABLE
)
7151 mt
= get_pageblock_migratetype(page
);
7152 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7155 pfn
= page_to_pfn(page
);
7156 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7157 unsigned long check
= pfn
+ iter
;
7159 if (!pfn_valid_within(check
))
7162 page
= pfn_to_page(check
);
7165 * Hugepages are not in LRU lists, but they're movable.
7166 * We need not scan over tail pages bacause we don't
7167 * handle each tail page individually in migration.
7169 if (PageHuge(page
)) {
7170 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7175 * We can't use page_count without pin a page
7176 * because another CPU can free compound page.
7177 * This check already skips compound tails of THP
7178 * because their page->_refcount is zero at all time.
7180 if (!page_ref_count(page
)) {
7181 if (PageBuddy(page
))
7182 iter
+= (1 << page_order(page
)) - 1;
7187 * The HWPoisoned page may be not in buddy system, and
7188 * page_count() is not 0.
7190 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7196 * If there are RECLAIMABLE pages, we need to check
7197 * it. But now, memory offline itself doesn't call
7198 * shrink_node_slabs() and it still to be fixed.
7201 * If the page is not RAM, page_count()should be 0.
7202 * we don't need more check. This is an _used_ not-movable page.
7204 * The problematic thing here is PG_reserved pages. PG_reserved
7205 * is set to both of a memory hole page and a _used_ kernel
7214 bool is_pageblock_removable_nolock(struct page
*page
)
7220 * We have to be careful here because we are iterating over memory
7221 * sections which are not zone aware so we might end up outside of
7222 * the zone but still within the section.
7223 * We have to take care about the node as well. If the node is offline
7224 * its NODE_DATA will be NULL - see page_zone.
7226 if (!node_online(page_to_nid(page
)))
7229 zone
= page_zone(page
);
7230 pfn
= page_to_pfn(page
);
7231 if (!zone_spans_pfn(zone
, pfn
))
7234 return !has_unmovable_pages(zone
, page
, 0, true);
7237 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7239 static unsigned long pfn_max_align_down(unsigned long pfn
)
7241 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7242 pageblock_nr_pages
) - 1);
7245 static unsigned long pfn_max_align_up(unsigned long pfn
)
7247 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7248 pageblock_nr_pages
));
7251 /* [start, end) must belong to a single zone. */
7252 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7253 unsigned long start
, unsigned long end
)
7255 /* This function is based on compact_zone() from compaction.c. */
7256 unsigned long nr_reclaimed
;
7257 unsigned long pfn
= start
;
7258 unsigned int tries
= 0;
7263 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7264 if (fatal_signal_pending(current
)) {
7269 if (list_empty(&cc
->migratepages
)) {
7270 cc
->nr_migratepages
= 0;
7271 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7277 } else if (++tries
== 5) {
7278 ret
= ret
< 0 ? ret
: -EBUSY
;
7282 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7284 cc
->nr_migratepages
-= nr_reclaimed
;
7286 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7287 NULL
, 0, cc
->mode
, MR_CMA
);
7290 putback_movable_pages(&cc
->migratepages
);
7297 * alloc_contig_range() -- tries to allocate given range of pages
7298 * @start: start PFN to allocate
7299 * @end: one-past-the-last PFN to allocate
7300 * @migratetype: migratetype of the underlaying pageblocks (either
7301 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7302 * in range must have the same migratetype and it must
7303 * be either of the two.
7305 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7306 * aligned, however it's the caller's responsibility to guarantee that
7307 * we are the only thread that changes migrate type of pageblocks the
7310 * The PFN range must belong to a single zone.
7312 * Returns zero on success or negative error code. On success all
7313 * pages which PFN is in [start, end) are allocated for the caller and
7314 * need to be freed with free_contig_range().
7316 int alloc_contig_range(unsigned long start
, unsigned long end
,
7317 unsigned migratetype
)
7319 unsigned long outer_start
, outer_end
;
7323 struct compact_control cc
= {
7324 .nr_migratepages
= 0,
7326 .zone
= page_zone(pfn_to_page(start
)),
7327 .mode
= MIGRATE_SYNC
,
7328 .ignore_skip_hint
= true,
7330 INIT_LIST_HEAD(&cc
.migratepages
);
7333 * What we do here is we mark all pageblocks in range as
7334 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7335 * have different sizes, and due to the way page allocator
7336 * work, we align the range to biggest of the two pages so
7337 * that page allocator won't try to merge buddies from
7338 * different pageblocks and change MIGRATE_ISOLATE to some
7339 * other migration type.
7341 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7342 * migrate the pages from an unaligned range (ie. pages that
7343 * we are interested in). This will put all the pages in
7344 * range back to page allocator as MIGRATE_ISOLATE.
7346 * When this is done, we take the pages in range from page
7347 * allocator removing them from the buddy system. This way
7348 * page allocator will never consider using them.
7350 * This lets us mark the pageblocks back as
7351 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7352 * aligned range but not in the unaligned, original range are
7353 * put back to page allocator so that buddy can use them.
7356 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7357 pfn_max_align_up(end
), migratetype
,
7363 * In case of -EBUSY, we'd like to know which page causes problem.
7364 * So, just fall through. We will check it in test_pages_isolated().
7366 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7367 if (ret
&& ret
!= -EBUSY
)
7371 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7372 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7373 * more, all pages in [start, end) are free in page allocator.
7374 * What we are going to do is to allocate all pages from
7375 * [start, end) (that is remove them from page allocator).
7377 * The only problem is that pages at the beginning and at the
7378 * end of interesting range may be not aligned with pages that
7379 * page allocator holds, ie. they can be part of higher order
7380 * pages. Because of this, we reserve the bigger range and
7381 * once this is done free the pages we are not interested in.
7383 * We don't have to hold zone->lock here because the pages are
7384 * isolated thus they won't get removed from buddy.
7387 lru_add_drain_all();
7388 drain_all_pages(cc
.zone
);
7391 outer_start
= start
;
7392 while (!PageBuddy(pfn_to_page(outer_start
))) {
7393 if (++order
>= MAX_ORDER
) {
7394 outer_start
= start
;
7397 outer_start
&= ~0UL << order
;
7400 if (outer_start
!= start
) {
7401 order
= page_order(pfn_to_page(outer_start
));
7404 * outer_start page could be small order buddy page and
7405 * it doesn't include start page. Adjust outer_start
7406 * in this case to report failed page properly
7407 * on tracepoint in test_pages_isolated()
7409 if (outer_start
+ (1UL << order
) <= start
)
7410 outer_start
= start
;
7413 /* Make sure the range is really isolated. */
7414 if (test_pages_isolated(outer_start
, end
, false)) {
7415 pr_info("%s: [%lx, %lx) PFNs busy\n",
7416 __func__
, outer_start
, end
);
7421 /* Grab isolated pages from freelists. */
7422 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7428 /* Free head and tail (if any) */
7429 if (start
!= outer_start
)
7430 free_contig_range(outer_start
, start
- outer_start
);
7431 if (end
!= outer_end
)
7432 free_contig_range(end
, outer_end
- end
);
7435 undo_isolate_page_range(pfn_max_align_down(start
),
7436 pfn_max_align_up(end
), migratetype
);
7440 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7442 unsigned int count
= 0;
7444 for (; nr_pages
--; pfn
++) {
7445 struct page
*page
= pfn_to_page(pfn
);
7447 count
+= page_count(page
) != 1;
7450 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7454 #ifdef CONFIG_MEMORY_HOTPLUG
7456 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7457 * page high values need to be recalulated.
7459 void __meminit
zone_pcp_update(struct zone
*zone
)
7462 mutex_lock(&pcp_batch_high_lock
);
7463 for_each_possible_cpu(cpu
)
7464 pageset_set_high_and_batch(zone
,
7465 per_cpu_ptr(zone
->pageset
, cpu
));
7466 mutex_unlock(&pcp_batch_high_lock
);
7470 void zone_pcp_reset(struct zone
*zone
)
7472 unsigned long flags
;
7474 struct per_cpu_pageset
*pset
;
7476 /* avoid races with drain_pages() */
7477 local_irq_save(flags
);
7478 if (zone
->pageset
!= &boot_pageset
) {
7479 for_each_online_cpu(cpu
) {
7480 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7481 drain_zonestat(zone
, pset
);
7483 free_percpu(zone
->pageset
);
7484 zone
->pageset
= &boot_pageset
;
7486 local_irq_restore(flags
);
7489 #ifdef CONFIG_MEMORY_HOTREMOVE
7491 * All pages in the range must be in a single zone and isolated
7492 * before calling this.
7495 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7499 unsigned int order
, i
;
7501 unsigned long flags
;
7502 /* find the first valid pfn */
7503 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7508 zone
= page_zone(pfn_to_page(pfn
));
7509 spin_lock_irqsave(&zone
->lock
, flags
);
7511 while (pfn
< end_pfn
) {
7512 if (!pfn_valid(pfn
)) {
7516 page
= pfn_to_page(pfn
);
7518 * The HWPoisoned page may be not in buddy system, and
7519 * page_count() is not 0.
7521 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7523 SetPageReserved(page
);
7527 BUG_ON(page_count(page
));
7528 BUG_ON(!PageBuddy(page
));
7529 order
= page_order(page
);
7530 #ifdef CONFIG_DEBUG_VM
7531 pr_info("remove from free list %lx %d %lx\n",
7532 pfn
, 1 << order
, end_pfn
);
7534 list_del(&page
->lru
);
7535 rmv_page_order(page
);
7536 zone
->free_area
[order
].nr_free
--;
7537 for (i
= 0; i
< (1 << order
); i
++)
7538 SetPageReserved((page
+i
));
7539 pfn
+= (1 << order
);
7541 spin_unlock_irqrestore(&zone
->lock
, flags
);
7545 bool is_free_buddy_page(struct page
*page
)
7547 struct zone
*zone
= page_zone(page
);
7548 unsigned long pfn
= page_to_pfn(page
);
7549 unsigned long flags
;
7552 spin_lock_irqsave(&zone
->lock
, flags
);
7553 for (order
= 0; order
< MAX_ORDER
; order
++) {
7554 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7556 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7559 spin_unlock_irqrestore(&zone
->lock
, flags
);
7561 return order
< MAX_ORDER
;