2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/memremap.h>
47 #include <linux/stop_machine.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page_ext.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66 #include <linux/memcontrol.h>
68 #include <asm/sections.h>
69 #include <asm/tlbflush.h>
70 #include <asm/div64.h>
73 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
74 static DEFINE_MUTEX(pcp_batch_high_lock
);
75 #define MIN_PERCPU_PAGELIST_FRACTION (8)
77 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
78 DEFINE_PER_CPU(int, numa_node
);
79 EXPORT_PER_CPU_SYMBOL(numa_node
);
82 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
84 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
85 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
86 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
87 * defined in <linux/topology.h>.
89 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
90 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
91 int _node_numa_mem_
[MAX_NUMNODES
];
95 * Array of node states.
97 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
98 [N_POSSIBLE
] = NODE_MASK_ALL
,
99 [N_ONLINE
] = { { [0] = 1UL } },
101 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
102 #ifdef CONFIG_HIGHMEM
103 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
105 #ifdef CONFIG_MOVABLE_NODE
106 [N_MEMORY
] = { { [0] = 1UL } },
108 [N_CPU
] = { { [0] = 1UL } },
111 EXPORT_SYMBOL(node_states
);
113 /* Protect totalram_pages and zone->managed_pages */
114 static DEFINE_SPINLOCK(managed_page_count_lock
);
116 unsigned long totalram_pages __read_mostly
;
117 unsigned long totalreserve_pages __read_mostly
;
118 unsigned long totalcma_pages __read_mostly
;
120 int percpu_pagelist_fraction
;
121 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
124 * A cached value of the page's pageblock's migratetype, used when the page is
125 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
126 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
127 * Also the migratetype set in the page does not necessarily match the pcplist
128 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
129 * other index - this ensures that it will be put on the correct CMA freelist.
131 static inline int get_pcppage_migratetype(struct page
*page
)
136 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
138 page
->index
= migratetype
;
141 #ifdef CONFIG_PM_SLEEP
143 * The following functions are used by the suspend/hibernate code to temporarily
144 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
145 * while devices are suspended. To avoid races with the suspend/hibernate code,
146 * they should always be called with pm_mutex held (gfp_allowed_mask also should
147 * only be modified with pm_mutex held, unless the suspend/hibernate code is
148 * guaranteed not to run in parallel with that modification).
151 static gfp_t saved_gfp_mask
;
153 void pm_restore_gfp_mask(void)
155 WARN_ON(!mutex_is_locked(&pm_mutex
));
156 if (saved_gfp_mask
) {
157 gfp_allowed_mask
= saved_gfp_mask
;
162 void pm_restrict_gfp_mask(void)
164 WARN_ON(!mutex_is_locked(&pm_mutex
));
165 WARN_ON(saved_gfp_mask
);
166 saved_gfp_mask
= gfp_allowed_mask
;
167 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
170 bool pm_suspended_storage(void)
172 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
176 #endif /* CONFIG_PM_SLEEP */
178 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
179 unsigned int pageblock_order __read_mostly
;
182 static void __free_pages_ok(struct page
*page
, unsigned int order
);
185 * results with 256, 32 in the lowmem_reserve sysctl:
186 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
187 * 1G machine -> (16M dma, 784M normal, 224M high)
188 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
189 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
190 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
192 * TBD: should special case ZONE_DMA32 machines here - in those we normally
193 * don't need any ZONE_NORMAL reservation
195 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
196 #ifdef CONFIG_ZONE_DMA
199 #ifdef CONFIG_ZONE_DMA32
202 #ifdef CONFIG_HIGHMEM
208 EXPORT_SYMBOL(totalram_pages
);
210 static char * const zone_names
[MAX_NR_ZONES
] = {
211 #ifdef CONFIG_ZONE_DMA
214 #ifdef CONFIG_ZONE_DMA32
218 #ifdef CONFIG_HIGHMEM
222 #ifdef CONFIG_ZONE_DEVICE
227 char * const migratetype_names
[MIGRATE_TYPES
] = {
235 #ifdef CONFIG_MEMORY_ISOLATION
240 compound_page_dtor
* const compound_page_dtors
[] = {
243 #ifdef CONFIG_HUGETLB_PAGE
246 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
251 int min_free_kbytes
= 1024;
252 int user_min_free_kbytes
= -1;
253 int watermark_scale_factor
= 10;
255 static unsigned long __meminitdata nr_kernel_pages
;
256 static unsigned long __meminitdata nr_all_pages
;
257 static unsigned long __meminitdata dma_reserve
;
259 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
260 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
261 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
262 static unsigned long __initdata required_kernelcore
;
263 static unsigned long __initdata required_movablecore
;
264 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
265 static bool mirrored_kernelcore
;
267 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
269 EXPORT_SYMBOL(movable_zone
);
270 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
273 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
274 int nr_online_nodes __read_mostly
= 1;
275 EXPORT_SYMBOL(nr_node_ids
);
276 EXPORT_SYMBOL(nr_online_nodes
);
279 int page_group_by_mobility_disabled __read_mostly
;
281 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
282 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
284 pgdat
->first_deferred_pfn
= ULONG_MAX
;
287 /* Returns true if the struct page for the pfn is uninitialised */
288 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
290 int nid
= early_pfn_to_nid(pfn
);
292 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
299 * Returns false when the remaining initialisation should be deferred until
300 * later in the boot cycle when it can be parallelised.
302 static inline bool update_defer_init(pg_data_t
*pgdat
,
303 unsigned long pfn
, unsigned long zone_end
,
304 unsigned long *nr_initialised
)
306 unsigned long max_initialise
;
308 /* Always populate low zones for address-contrained allocations */
309 if (zone_end
< pgdat_end_pfn(pgdat
))
312 * Initialise at least 2G of a node but also take into account that
313 * two large system hashes that can take up 1GB for 0.25TB/node.
315 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
316 (pgdat
->node_spanned_pages
>> 8));
319 if ((*nr_initialised
> max_initialise
) &&
320 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
321 pgdat
->first_deferred_pfn
= pfn
;
328 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
332 static inline bool early_page_uninitialised(unsigned long pfn
)
337 static inline bool update_defer_init(pg_data_t
*pgdat
,
338 unsigned long pfn
, unsigned long zone_end
,
339 unsigned long *nr_initialised
)
345 /* Return a pointer to the bitmap storing bits affecting a block of pages */
346 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
349 #ifdef CONFIG_SPARSEMEM
350 return __pfn_to_section(pfn
)->pageblock_flags
;
352 return page_zone(page
)->pageblock_flags
;
353 #endif /* CONFIG_SPARSEMEM */
356 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
358 #ifdef CONFIG_SPARSEMEM
359 pfn
&= (PAGES_PER_SECTION
-1);
360 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
362 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
363 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
364 #endif /* CONFIG_SPARSEMEM */
368 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
369 * @page: The page within the block of interest
370 * @pfn: The target page frame number
371 * @end_bitidx: The last bit of interest to retrieve
372 * @mask: mask of bits that the caller is interested in
374 * Return: pageblock_bits flags
376 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
378 unsigned long end_bitidx
,
381 unsigned long *bitmap
;
382 unsigned long bitidx
, word_bitidx
;
385 bitmap
= get_pageblock_bitmap(page
, pfn
);
386 bitidx
= pfn_to_bitidx(page
, pfn
);
387 word_bitidx
= bitidx
/ BITS_PER_LONG
;
388 bitidx
&= (BITS_PER_LONG
-1);
390 word
= bitmap
[word_bitidx
];
391 bitidx
+= end_bitidx
;
392 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
395 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
396 unsigned long end_bitidx
,
399 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
402 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
404 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
408 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
409 * @page: The page within the block of interest
410 * @flags: The flags to set
411 * @pfn: The target page frame number
412 * @end_bitidx: The last bit of interest
413 * @mask: mask of bits that the caller is interested in
415 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
417 unsigned long end_bitidx
,
420 unsigned long *bitmap
;
421 unsigned long bitidx
, word_bitidx
;
422 unsigned long old_word
, word
;
424 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
426 bitmap
= get_pageblock_bitmap(page
, pfn
);
427 bitidx
= pfn_to_bitidx(page
, pfn
);
428 word_bitidx
= bitidx
/ BITS_PER_LONG
;
429 bitidx
&= (BITS_PER_LONG
-1);
431 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
433 bitidx
+= end_bitidx
;
434 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
435 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
437 word
= READ_ONCE(bitmap
[word_bitidx
]);
439 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
440 if (word
== old_word
)
446 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
448 if (unlikely(page_group_by_mobility_disabled
&&
449 migratetype
< MIGRATE_PCPTYPES
))
450 migratetype
= MIGRATE_UNMOVABLE
;
452 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
453 PB_migrate
, PB_migrate_end
);
456 #ifdef CONFIG_DEBUG_VM
457 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
461 unsigned long pfn
= page_to_pfn(page
);
462 unsigned long sp
, start_pfn
;
465 seq
= zone_span_seqbegin(zone
);
466 start_pfn
= zone
->zone_start_pfn
;
467 sp
= zone
->spanned_pages
;
468 if (!zone_spans_pfn(zone
, pfn
))
470 } while (zone_span_seqretry(zone
, seq
));
473 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
474 pfn
, zone_to_nid(zone
), zone
->name
,
475 start_pfn
, start_pfn
+ sp
);
480 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
482 if (!pfn_valid_within(page_to_pfn(page
)))
484 if (zone
!= page_zone(page
))
490 * Temporary debugging check for pages not lying within a given zone.
492 static int bad_range(struct zone
*zone
, struct page
*page
)
494 if (page_outside_zone_boundaries(zone
, page
))
496 if (!page_is_consistent(zone
, page
))
502 static inline int bad_range(struct zone
*zone
, struct page
*page
)
508 static void bad_page(struct page
*page
, const char *reason
,
509 unsigned long bad_flags
)
511 static unsigned long resume
;
512 static unsigned long nr_shown
;
513 static unsigned long nr_unshown
;
516 * Allow a burst of 60 reports, then keep quiet for that minute;
517 * or allow a steady drip of one report per second.
519 if (nr_shown
== 60) {
520 if (time_before(jiffies
, resume
)) {
526 "BUG: Bad page state: %lu messages suppressed\n",
533 resume
= jiffies
+ 60 * HZ
;
535 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
536 current
->comm
, page_to_pfn(page
));
537 __dump_page(page
, reason
);
538 bad_flags
&= page
->flags
;
540 pr_alert("bad because of flags: %#lx(%pGp)\n",
541 bad_flags
, &bad_flags
);
542 dump_page_owner(page
);
547 /* Leave bad fields for debug, except PageBuddy could make trouble */
548 page_mapcount_reset(page
); /* remove PageBuddy */
549 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
553 * Higher-order pages are called "compound pages". They are structured thusly:
555 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
557 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
558 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
560 * The first tail page's ->compound_dtor holds the offset in array of compound
561 * page destructors. See compound_page_dtors.
563 * The first tail page's ->compound_order holds the order of allocation.
564 * This usage means that zero-order pages may not be compound.
567 void free_compound_page(struct page
*page
)
569 __free_pages_ok(page
, compound_order(page
));
572 void prep_compound_page(struct page
*page
, unsigned int order
)
575 int nr_pages
= 1 << order
;
577 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
578 set_compound_order(page
, order
);
580 for (i
= 1; i
< nr_pages
; i
++) {
581 struct page
*p
= page
+ i
;
582 set_page_count(p
, 0);
583 p
->mapping
= TAIL_MAPPING
;
584 set_compound_head(p
, page
);
586 atomic_set(compound_mapcount_ptr(page
), -1);
589 #ifdef CONFIG_DEBUG_PAGEALLOC
590 unsigned int _debug_guardpage_minorder
;
591 bool _debug_pagealloc_enabled __read_mostly
592 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
593 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
594 bool _debug_guardpage_enabled __read_mostly
;
596 static int __init
early_debug_pagealloc(char *buf
)
600 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
602 early_param("debug_pagealloc", early_debug_pagealloc
);
604 static bool need_debug_guardpage(void)
606 /* If we don't use debug_pagealloc, we don't need guard page */
607 if (!debug_pagealloc_enabled())
613 static void init_debug_guardpage(void)
615 if (!debug_pagealloc_enabled())
618 _debug_guardpage_enabled
= true;
621 struct page_ext_operations debug_guardpage_ops
= {
622 .need
= need_debug_guardpage
,
623 .init
= init_debug_guardpage
,
626 static int __init
debug_guardpage_minorder_setup(char *buf
)
630 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
631 pr_err("Bad debug_guardpage_minorder value\n");
634 _debug_guardpage_minorder
= res
;
635 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
638 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
640 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
641 unsigned int order
, int migratetype
)
643 struct page_ext
*page_ext
;
645 if (!debug_guardpage_enabled())
648 page_ext
= lookup_page_ext(page
);
649 if (unlikely(!page_ext
))
652 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
654 INIT_LIST_HEAD(&page
->lru
);
655 set_page_private(page
, order
);
656 /* Guard pages are not available for any usage */
657 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
660 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
661 unsigned int order
, int migratetype
)
663 struct page_ext
*page_ext
;
665 if (!debug_guardpage_enabled())
668 page_ext
= lookup_page_ext(page
);
669 if (unlikely(!page_ext
))
672 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
674 set_page_private(page
, 0);
675 if (!is_migrate_isolate(migratetype
))
676 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
679 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
680 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
681 unsigned int order
, int migratetype
) {}
682 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
683 unsigned int order
, int migratetype
) {}
686 static inline void set_page_order(struct page
*page
, unsigned int order
)
688 set_page_private(page
, order
);
689 __SetPageBuddy(page
);
692 static inline void rmv_page_order(struct page
*page
)
694 __ClearPageBuddy(page
);
695 set_page_private(page
, 0);
699 * This function checks whether a page is free && is the buddy
700 * we can do coalesce a page and its buddy if
701 * (a) the buddy is not in a hole &&
702 * (b) the buddy is in the buddy system &&
703 * (c) a page and its buddy have the same order &&
704 * (d) a page and its buddy are in the same zone.
706 * For recording whether a page is in the buddy system, we set ->_mapcount
707 * PAGE_BUDDY_MAPCOUNT_VALUE.
708 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
709 * serialized by zone->lock.
711 * For recording page's order, we use page_private(page).
713 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
716 if (!pfn_valid_within(page_to_pfn(buddy
)))
719 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
720 if (page_zone_id(page
) != page_zone_id(buddy
))
723 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
728 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
730 * zone check is done late to avoid uselessly
731 * calculating zone/node ids for pages that could
734 if (page_zone_id(page
) != page_zone_id(buddy
))
737 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
745 * Freeing function for a buddy system allocator.
747 * The concept of a buddy system is to maintain direct-mapped table
748 * (containing bit values) for memory blocks of various "orders".
749 * The bottom level table contains the map for the smallest allocatable
750 * units of memory (here, pages), and each level above it describes
751 * pairs of units from the levels below, hence, "buddies".
752 * At a high level, all that happens here is marking the table entry
753 * at the bottom level available, and propagating the changes upward
754 * as necessary, plus some accounting needed to play nicely with other
755 * parts of the VM system.
756 * At each level, we keep a list of pages, which are heads of continuous
757 * free pages of length of (1 << order) and marked with _mapcount
758 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
760 * So when we are allocating or freeing one, we can derive the state of the
761 * other. That is, if we allocate a small block, and both were
762 * free, the remainder of the region must be split into blocks.
763 * If a block is freed, and its buddy is also free, then this
764 * triggers coalescing into a block of larger size.
769 static inline void __free_one_page(struct page
*page
,
771 struct zone
*zone
, unsigned int order
,
774 unsigned long page_idx
;
775 unsigned long combined_idx
;
776 unsigned long uninitialized_var(buddy_idx
);
778 unsigned int max_order
;
780 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
782 VM_BUG_ON(!zone_is_initialized(zone
));
783 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
785 VM_BUG_ON(migratetype
== -1);
786 if (likely(!is_migrate_isolate(migratetype
)))
787 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
789 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
791 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
792 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
795 while (order
< max_order
- 1) {
796 buddy_idx
= __find_buddy_index(page_idx
, order
);
797 buddy
= page
+ (buddy_idx
- page_idx
);
798 if (!page_is_buddy(page
, buddy
, order
))
801 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
802 * merge with it and move up one order.
804 if (page_is_guard(buddy
)) {
805 clear_page_guard(zone
, buddy
, order
, migratetype
);
807 list_del(&buddy
->lru
);
808 zone
->free_area
[order
].nr_free
--;
809 rmv_page_order(buddy
);
811 combined_idx
= buddy_idx
& page_idx
;
812 page
= page
+ (combined_idx
- page_idx
);
813 page_idx
= combined_idx
;
816 if (max_order
< MAX_ORDER
) {
817 /* If we are here, it means order is >= pageblock_order.
818 * We want to prevent merge between freepages on isolate
819 * pageblock and normal pageblock. Without this, pageblock
820 * isolation could cause incorrect freepage or CMA accounting.
822 * We don't want to hit this code for the more frequent
825 if (unlikely(has_isolate_pageblock(zone
))) {
828 buddy_idx
= __find_buddy_index(page_idx
, order
);
829 buddy
= page
+ (buddy_idx
- page_idx
);
830 buddy_mt
= get_pageblock_migratetype(buddy
);
832 if (migratetype
!= buddy_mt
833 && (is_migrate_isolate(migratetype
) ||
834 is_migrate_isolate(buddy_mt
)))
838 goto continue_merging
;
842 set_page_order(page
, order
);
845 * If this is not the largest possible page, check if the buddy
846 * of the next-highest order is free. If it is, it's possible
847 * that pages are being freed that will coalesce soon. In case,
848 * that is happening, add the free page to the tail of the list
849 * so it's less likely to be used soon and more likely to be merged
850 * as a higher order page
852 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
853 struct page
*higher_page
, *higher_buddy
;
854 combined_idx
= buddy_idx
& page_idx
;
855 higher_page
= page
+ (combined_idx
- page_idx
);
856 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
857 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
858 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
859 list_add_tail(&page
->lru
,
860 &zone
->free_area
[order
].free_list
[migratetype
]);
865 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
867 zone
->free_area
[order
].nr_free
++;
871 * A bad page could be due to a number of fields. Instead of multiple branches,
872 * try and check multiple fields with one check. The caller must do a detailed
873 * check if necessary.
875 static inline bool page_expected_state(struct page
*page
,
876 unsigned long check_flags
)
878 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
881 if (unlikely((unsigned long)page
->mapping
|
882 page_ref_count(page
) |
884 (unsigned long)page
->mem_cgroup
|
886 (page
->flags
& check_flags
)))
892 static void free_pages_check_bad(struct page
*page
)
894 const char *bad_reason
;
895 unsigned long bad_flags
;
900 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
901 bad_reason
= "nonzero mapcount";
902 if (unlikely(page
->mapping
!= NULL
))
903 bad_reason
= "non-NULL mapping";
904 if (unlikely(page_ref_count(page
) != 0))
905 bad_reason
= "nonzero _refcount";
906 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
907 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
908 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
911 if (unlikely(page
->mem_cgroup
))
912 bad_reason
= "page still charged to cgroup";
914 bad_page(page
, bad_reason
, bad_flags
);
917 static inline int free_pages_check(struct page
*page
)
919 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
922 /* Something has gone sideways, find it */
923 free_pages_check_bad(page
);
927 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
932 * We rely page->lru.next never has bit 0 set, unless the page
933 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
935 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
937 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
941 switch (page
- head_page
) {
943 /* the first tail page: ->mapping is compound_mapcount() */
944 if (unlikely(compound_mapcount(page
))) {
945 bad_page(page
, "nonzero compound_mapcount", 0);
951 * the second tail page: ->mapping is
952 * page_deferred_list().next -- ignore value.
956 if (page
->mapping
!= TAIL_MAPPING
) {
957 bad_page(page
, "corrupted mapping in tail page", 0);
962 if (unlikely(!PageTail(page
))) {
963 bad_page(page
, "PageTail not set", 0);
966 if (unlikely(compound_head(page
) != head_page
)) {
967 bad_page(page
, "compound_head not consistent", 0);
972 page
->mapping
= NULL
;
973 clear_compound_head(page
);
977 static __always_inline
bool free_pages_prepare(struct page
*page
,
978 unsigned int order
, bool check_free
)
982 VM_BUG_ON_PAGE(PageTail(page
), page
);
984 trace_mm_page_free(page
, order
);
985 kmemcheck_free_shadow(page
, order
);
988 * Check tail pages before head page information is cleared to
989 * avoid checking PageCompound for order-0 pages.
991 if (unlikely(order
)) {
992 bool compound
= PageCompound(page
);
995 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
998 ClearPageDoubleMap(page
);
999 for (i
= 1; i
< (1 << order
); i
++) {
1001 bad
+= free_tail_pages_check(page
, page
+ i
);
1002 if (unlikely(free_pages_check(page
+ i
))) {
1006 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1009 if (PageMappingFlags(page
))
1010 page
->mapping
= NULL
;
1011 if (memcg_kmem_enabled() && PageKmemcg(page
)) {
1012 memcg_kmem_uncharge(page
, order
);
1013 __ClearPageKmemcg(page
);
1016 bad
+= free_pages_check(page
);
1020 page_cpupid_reset_last(page
);
1021 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1022 reset_page_owner(page
, order
);
1024 if (!PageHighMem(page
)) {
1025 debug_check_no_locks_freed(page_address(page
),
1026 PAGE_SIZE
<< order
);
1027 debug_check_no_obj_freed(page_address(page
),
1028 PAGE_SIZE
<< order
);
1030 arch_free_page(page
, order
);
1031 kernel_poison_pages(page
, 1 << order
, 0);
1032 kernel_map_pages(page
, 1 << order
, 0);
1033 kasan_free_pages(page
, order
);
1038 #ifdef CONFIG_DEBUG_VM
1039 static inline bool free_pcp_prepare(struct page
*page
)
1041 return free_pages_prepare(page
, 0, true);
1044 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1049 static bool free_pcp_prepare(struct page
*page
)
1051 return free_pages_prepare(page
, 0, false);
1054 static bool bulkfree_pcp_prepare(struct page
*page
)
1056 return free_pages_check(page
);
1058 #endif /* CONFIG_DEBUG_VM */
1061 * Frees a number of pages from the PCP lists
1062 * Assumes all pages on list are in same zone, and of same order.
1063 * count is the number of pages to free.
1065 * If the zone was previously in an "all pages pinned" state then look to
1066 * see if this freeing clears that state.
1068 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1069 * pinned" detection logic.
1071 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1072 struct per_cpu_pages
*pcp
)
1074 int migratetype
= 0;
1076 unsigned long nr_scanned
;
1077 bool isolated_pageblocks
;
1079 spin_lock(&zone
->lock
);
1080 isolated_pageblocks
= has_isolate_pageblock(zone
);
1081 nr_scanned
= node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
);
1083 __mod_node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
, -nr_scanned
);
1087 struct list_head
*list
;
1090 * Remove pages from lists in a round-robin fashion. A
1091 * batch_free count is maintained that is incremented when an
1092 * empty list is encountered. This is so more pages are freed
1093 * off fuller lists instead of spinning excessively around empty
1098 if (++migratetype
== MIGRATE_PCPTYPES
)
1100 list
= &pcp
->lists
[migratetype
];
1101 } while (list_empty(list
));
1103 /* This is the only non-empty list. Free them all. */
1104 if (batch_free
== MIGRATE_PCPTYPES
)
1108 int mt
; /* migratetype of the to-be-freed page */
1110 page
= list_last_entry(list
, struct page
, lru
);
1111 /* must delete as __free_one_page list manipulates */
1112 list_del(&page
->lru
);
1114 mt
= get_pcppage_migratetype(page
);
1115 /* MIGRATE_ISOLATE page should not go to pcplists */
1116 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1117 /* Pageblock could have been isolated meanwhile */
1118 if (unlikely(isolated_pageblocks
))
1119 mt
= get_pageblock_migratetype(page
);
1121 if (bulkfree_pcp_prepare(page
))
1124 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1125 trace_mm_page_pcpu_drain(page
, 0, mt
);
1126 } while (--count
&& --batch_free
&& !list_empty(list
));
1128 spin_unlock(&zone
->lock
);
1131 static void free_one_page(struct zone
*zone
,
1132 struct page
*page
, unsigned long pfn
,
1136 unsigned long nr_scanned
;
1137 spin_lock(&zone
->lock
);
1138 nr_scanned
= node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
);
1140 __mod_node_page_state(zone
->zone_pgdat
, NR_PAGES_SCANNED
, -nr_scanned
);
1142 if (unlikely(has_isolate_pageblock(zone
) ||
1143 is_migrate_isolate(migratetype
))) {
1144 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1146 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1147 spin_unlock(&zone
->lock
);
1150 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1151 unsigned long zone
, int nid
)
1153 set_page_links(page
, zone
, nid
, pfn
);
1154 init_page_count(page
);
1155 page_mapcount_reset(page
);
1156 page_cpupid_reset_last(page
);
1158 INIT_LIST_HEAD(&page
->lru
);
1159 #ifdef WANT_PAGE_VIRTUAL
1160 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1161 if (!is_highmem_idx(zone
))
1162 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1166 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1169 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1172 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1173 static void init_reserved_page(unsigned long pfn
)
1178 if (!early_page_uninitialised(pfn
))
1181 nid
= early_pfn_to_nid(pfn
);
1182 pgdat
= NODE_DATA(nid
);
1184 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1185 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1187 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1190 __init_single_pfn(pfn
, zid
, nid
);
1193 static inline void init_reserved_page(unsigned long pfn
)
1196 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1199 * Initialised pages do not have PageReserved set. This function is
1200 * called for each range allocated by the bootmem allocator and
1201 * marks the pages PageReserved. The remaining valid pages are later
1202 * sent to the buddy page allocator.
1204 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1206 unsigned long start_pfn
= PFN_DOWN(start
);
1207 unsigned long end_pfn
= PFN_UP(end
);
1209 for (; start_pfn
< end_pfn
; start_pfn
++) {
1210 if (pfn_valid(start_pfn
)) {
1211 struct page
*page
= pfn_to_page(start_pfn
);
1213 init_reserved_page(start_pfn
);
1215 /* Avoid false-positive PageTail() */
1216 INIT_LIST_HEAD(&page
->lru
);
1218 SetPageReserved(page
);
1223 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1225 unsigned long flags
;
1227 unsigned long pfn
= page_to_pfn(page
);
1229 if (!free_pages_prepare(page
, order
, true))
1232 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1233 local_irq_save(flags
);
1234 __count_vm_events(PGFREE
, 1 << order
);
1235 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1236 local_irq_restore(flags
);
1239 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1241 unsigned int nr_pages
= 1 << order
;
1242 struct page
*p
= page
;
1246 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1248 __ClearPageReserved(p
);
1249 set_page_count(p
, 0);
1251 __ClearPageReserved(p
);
1252 set_page_count(p
, 0);
1254 page_zone(page
)->managed_pages
+= nr_pages
;
1255 set_page_refcounted(page
);
1256 __free_pages(page
, order
);
1259 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1260 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1262 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1264 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1266 static DEFINE_SPINLOCK(early_pfn_lock
);
1269 spin_lock(&early_pfn_lock
);
1270 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1272 nid
= first_online_node
;
1273 spin_unlock(&early_pfn_lock
);
1279 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1280 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1281 struct mminit_pfnnid_cache
*state
)
1285 nid
= __early_pfn_to_nid(pfn
, state
);
1286 if (nid
>= 0 && nid
!= node
)
1291 /* Only safe to use early in boot when initialisation is single-threaded */
1292 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1294 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1299 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1303 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1304 struct mminit_pfnnid_cache
*state
)
1311 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1314 if (early_page_uninitialised(pfn
))
1316 return __free_pages_boot_core(page
, order
);
1320 * Check that the whole (or subset of) a pageblock given by the interval of
1321 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1322 * with the migration of free compaction scanner. The scanners then need to
1323 * use only pfn_valid_within() check for arches that allow holes within
1326 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1328 * It's possible on some configurations to have a setup like node0 node1 node0
1329 * i.e. it's possible that all pages within a zones range of pages do not
1330 * belong to a single zone. We assume that a border between node0 and node1
1331 * can occur within a single pageblock, but not a node0 node1 node0
1332 * interleaving within a single pageblock. It is therefore sufficient to check
1333 * the first and last page of a pageblock and avoid checking each individual
1334 * page in a pageblock.
1336 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1337 unsigned long end_pfn
, struct zone
*zone
)
1339 struct page
*start_page
;
1340 struct page
*end_page
;
1342 /* end_pfn is one past the range we are checking */
1345 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1348 start_page
= pfn_to_page(start_pfn
);
1350 if (page_zone(start_page
) != zone
)
1353 end_page
= pfn_to_page(end_pfn
);
1355 /* This gives a shorter code than deriving page_zone(end_page) */
1356 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1362 void set_zone_contiguous(struct zone
*zone
)
1364 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1365 unsigned long block_end_pfn
;
1367 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1368 for (; block_start_pfn
< zone_end_pfn(zone
);
1369 block_start_pfn
= block_end_pfn
,
1370 block_end_pfn
+= pageblock_nr_pages
) {
1372 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1374 if (!__pageblock_pfn_to_page(block_start_pfn
,
1375 block_end_pfn
, zone
))
1379 /* We confirm that there is no hole */
1380 zone
->contiguous
= true;
1383 void clear_zone_contiguous(struct zone
*zone
)
1385 zone
->contiguous
= false;
1388 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1389 static void __init
deferred_free_range(struct page
*page
,
1390 unsigned long pfn
, int nr_pages
)
1397 /* Free a large naturally-aligned chunk if possible */
1398 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1399 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1400 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1401 __free_pages_boot_core(page
, MAX_ORDER
-1);
1405 for (i
= 0; i
< nr_pages
; i
++, page
++)
1406 __free_pages_boot_core(page
, 0);
1409 /* Completion tracking for deferred_init_memmap() threads */
1410 static atomic_t pgdat_init_n_undone __initdata
;
1411 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1413 static inline void __init
pgdat_init_report_one_done(void)
1415 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1416 complete(&pgdat_init_all_done_comp
);
1419 /* Initialise remaining memory on a node */
1420 static int __init
deferred_init_memmap(void *data
)
1422 pg_data_t
*pgdat
= data
;
1423 int nid
= pgdat
->node_id
;
1424 struct mminit_pfnnid_cache nid_init_state
= { };
1425 unsigned long start
= jiffies
;
1426 unsigned long nr_pages
= 0;
1427 unsigned long walk_start
, walk_end
;
1430 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1431 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1433 if (first_init_pfn
== ULONG_MAX
) {
1434 pgdat_init_report_one_done();
1438 /* Bind memory initialisation thread to a local node if possible */
1439 if (!cpumask_empty(cpumask
))
1440 set_cpus_allowed_ptr(current
, cpumask
);
1442 /* Sanity check boundaries */
1443 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1444 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1445 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1447 /* Only the highest zone is deferred so find it */
1448 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1449 zone
= pgdat
->node_zones
+ zid
;
1450 if (first_init_pfn
< zone_end_pfn(zone
))
1454 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1455 unsigned long pfn
, end_pfn
;
1456 struct page
*page
= NULL
;
1457 struct page
*free_base_page
= NULL
;
1458 unsigned long free_base_pfn
= 0;
1461 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1462 pfn
= first_init_pfn
;
1463 if (pfn
< walk_start
)
1465 if (pfn
< zone
->zone_start_pfn
)
1466 pfn
= zone
->zone_start_pfn
;
1468 for (; pfn
< end_pfn
; pfn
++) {
1469 if (!pfn_valid_within(pfn
))
1473 * Ensure pfn_valid is checked every
1474 * MAX_ORDER_NR_PAGES for memory holes
1476 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1477 if (!pfn_valid(pfn
)) {
1483 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1488 /* Minimise pfn page lookups and scheduler checks */
1489 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1492 nr_pages
+= nr_to_free
;
1493 deferred_free_range(free_base_page
,
1494 free_base_pfn
, nr_to_free
);
1495 free_base_page
= NULL
;
1496 free_base_pfn
= nr_to_free
= 0;
1498 page
= pfn_to_page(pfn
);
1503 VM_BUG_ON(page_zone(page
) != zone
);
1507 __init_single_page(page
, pfn
, zid
, nid
);
1508 if (!free_base_page
) {
1509 free_base_page
= page
;
1510 free_base_pfn
= pfn
;
1515 /* Where possible, batch up pages for a single free */
1518 /* Free the current block of pages to allocator */
1519 nr_pages
+= nr_to_free
;
1520 deferred_free_range(free_base_page
, free_base_pfn
,
1522 free_base_page
= NULL
;
1523 free_base_pfn
= nr_to_free
= 0;
1526 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1529 /* Sanity check that the next zone really is unpopulated */
1530 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1532 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1533 jiffies_to_msecs(jiffies
- start
));
1535 pgdat_init_report_one_done();
1538 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1540 void __init
page_alloc_init_late(void)
1544 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1547 /* There will be num_node_state(N_MEMORY) threads */
1548 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1549 for_each_node_state(nid
, N_MEMORY
) {
1550 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1553 /* Block until all are initialised */
1554 wait_for_completion(&pgdat_init_all_done_comp
);
1556 /* Reinit limits that are based on free pages after the kernel is up */
1557 files_maxfiles_init();
1560 for_each_populated_zone(zone
)
1561 set_zone_contiguous(zone
);
1565 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1566 void __init
init_cma_reserved_pageblock(struct page
*page
)
1568 unsigned i
= pageblock_nr_pages
;
1569 struct page
*p
= page
;
1572 __ClearPageReserved(p
);
1573 set_page_count(p
, 0);
1576 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1578 if (pageblock_order
>= MAX_ORDER
) {
1579 i
= pageblock_nr_pages
;
1582 set_page_refcounted(p
);
1583 __free_pages(p
, MAX_ORDER
- 1);
1584 p
+= MAX_ORDER_NR_PAGES
;
1585 } while (i
-= MAX_ORDER_NR_PAGES
);
1587 set_page_refcounted(page
);
1588 __free_pages(page
, pageblock_order
);
1591 adjust_managed_page_count(page
, pageblock_nr_pages
);
1596 * The order of subdivision here is critical for the IO subsystem.
1597 * Please do not alter this order without good reasons and regression
1598 * testing. Specifically, as large blocks of memory are subdivided,
1599 * the order in which smaller blocks are delivered depends on the order
1600 * they're subdivided in this function. This is the primary factor
1601 * influencing the order in which pages are delivered to the IO
1602 * subsystem according to empirical testing, and this is also justified
1603 * by considering the behavior of a buddy system containing a single
1604 * large block of memory acted on by a series of small allocations.
1605 * This behavior is a critical factor in sglist merging's success.
1609 static inline void expand(struct zone
*zone
, struct page
*page
,
1610 int low
, int high
, struct free_area
*area
,
1613 unsigned long size
= 1 << high
;
1615 while (high
> low
) {
1619 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1621 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1622 debug_guardpage_enabled() &&
1623 high
< debug_guardpage_minorder()) {
1625 * Mark as guard pages (or page), that will allow to
1626 * merge back to allocator when buddy will be freed.
1627 * Corresponding page table entries will not be touched,
1628 * pages will stay not present in virtual address space
1630 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1633 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1635 set_page_order(&page
[size
], high
);
1639 static void check_new_page_bad(struct page
*page
)
1641 const char *bad_reason
= NULL
;
1642 unsigned long bad_flags
= 0;
1644 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1645 bad_reason
= "nonzero mapcount";
1646 if (unlikely(page
->mapping
!= NULL
))
1647 bad_reason
= "non-NULL mapping";
1648 if (unlikely(page_ref_count(page
) != 0))
1649 bad_reason
= "nonzero _count";
1650 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1651 bad_reason
= "HWPoisoned (hardware-corrupted)";
1652 bad_flags
= __PG_HWPOISON
;
1653 /* Don't complain about hwpoisoned pages */
1654 page_mapcount_reset(page
); /* remove PageBuddy */
1657 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1658 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1659 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1662 if (unlikely(page
->mem_cgroup
))
1663 bad_reason
= "page still charged to cgroup";
1665 bad_page(page
, bad_reason
, bad_flags
);
1669 * This page is about to be returned from the page allocator
1671 static inline int check_new_page(struct page
*page
)
1673 if (likely(page_expected_state(page
,
1674 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1677 check_new_page_bad(page
);
1681 static inline bool free_pages_prezeroed(bool poisoned
)
1683 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1684 page_poisoning_enabled() && poisoned
;
1687 #ifdef CONFIG_DEBUG_VM
1688 static bool check_pcp_refill(struct page
*page
)
1693 static bool check_new_pcp(struct page
*page
)
1695 return check_new_page(page
);
1698 static bool check_pcp_refill(struct page
*page
)
1700 return check_new_page(page
);
1702 static bool check_new_pcp(struct page
*page
)
1706 #endif /* CONFIG_DEBUG_VM */
1708 static bool check_new_pages(struct page
*page
, unsigned int order
)
1711 for (i
= 0; i
< (1 << order
); i
++) {
1712 struct page
*p
= page
+ i
;
1714 if (unlikely(check_new_page(p
)))
1721 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1724 set_page_private(page
, 0);
1725 set_page_refcounted(page
);
1727 arch_alloc_page(page
, order
);
1728 kernel_map_pages(page
, 1 << order
, 1);
1729 kernel_poison_pages(page
, 1 << order
, 1);
1730 kasan_alloc_pages(page
, order
);
1731 set_page_owner(page
, order
, gfp_flags
);
1734 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1735 unsigned int alloc_flags
)
1738 bool poisoned
= true;
1740 for (i
= 0; i
< (1 << order
); i
++) {
1741 struct page
*p
= page
+ i
;
1743 poisoned
&= page_is_poisoned(p
);
1746 post_alloc_hook(page
, order
, gfp_flags
);
1748 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1749 for (i
= 0; i
< (1 << order
); i
++)
1750 clear_highpage(page
+ i
);
1752 if (order
&& (gfp_flags
& __GFP_COMP
))
1753 prep_compound_page(page
, order
);
1756 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1757 * allocate the page. The expectation is that the caller is taking
1758 * steps that will free more memory. The caller should avoid the page
1759 * being used for !PFMEMALLOC purposes.
1761 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1762 set_page_pfmemalloc(page
);
1764 clear_page_pfmemalloc(page
);
1768 * Go through the free lists for the given migratetype and remove
1769 * the smallest available page from the freelists
1772 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1775 unsigned int current_order
;
1776 struct free_area
*area
;
1779 /* Find a page of the appropriate size in the preferred list */
1780 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1781 area
= &(zone
->free_area
[current_order
]);
1782 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1786 list_del(&page
->lru
);
1787 rmv_page_order(page
);
1789 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1790 set_pcppage_migratetype(page
, migratetype
);
1799 * This array describes the order lists are fallen back to when
1800 * the free lists for the desirable migrate type are depleted
1802 static int fallbacks
[MIGRATE_TYPES
][4] = {
1803 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1804 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1805 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1807 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1809 #ifdef CONFIG_MEMORY_ISOLATION
1810 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1815 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1818 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1821 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1822 unsigned int order
) { return NULL
; }
1826 * Move the free pages in a range to the free lists of the requested type.
1827 * Note that start_page and end_pages are not aligned on a pageblock
1828 * boundary. If alignment is required, use move_freepages_block()
1830 int move_freepages(struct zone
*zone
,
1831 struct page
*start_page
, struct page
*end_page
,
1836 int pages_moved
= 0;
1838 #ifndef CONFIG_HOLES_IN_ZONE
1840 * page_zone is not safe to call in this context when
1841 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1842 * anyway as we check zone boundaries in move_freepages_block().
1843 * Remove at a later date when no bug reports exist related to
1844 * grouping pages by mobility
1846 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1849 for (page
= start_page
; page
<= end_page
;) {
1850 /* Make sure we are not inadvertently changing nodes */
1851 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1853 if (!pfn_valid_within(page_to_pfn(page
))) {
1858 if (!PageBuddy(page
)) {
1863 order
= page_order(page
);
1864 list_move(&page
->lru
,
1865 &zone
->free_area
[order
].free_list
[migratetype
]);
1867 pages_moved
+= 1 << order
;
1873 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1876 unsigned long start_pfn
, end_pfn
;
1877 struct page
*start_page
, *end_page
;
1879 start_pfn
= page_to_pfn(page
);
1880 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1881 start_page
= pfn_to_page(start_pfn
);
1882 end_page
= start_page
+ pageblock_nr_pages
- 1;
1883 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1885 /* Do not cross zone boundaries */
1886 if (!zone_spans_pfn(zone
, start_pfn
))
1888 if (!zone_spans_pfn(zone
, end_pfn
))
1891 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1894 static void change_pageblock_range(struct page
*pageblock_page
,
1895 int start_order
, int migratetype
)
1897 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1899 while (nr_pageblocks
--) {
1900 set_pageblock_migratetype(pageblock_page
, migratetype
);
1901 pageblock_page
+= pageblock_nr_pages
;
1906 * When we are falling back to another migratetype during allocation, try to
1907 * steal extra free pages from the same pageblocks to satisfy further
1908 * allocations, instead of polluting multiple pageblocks.
1910 * If we are stealing a relatively large buddy page, it is likely there will
1911 * be more free pages in the pageblock, so try to steal them all. For
1912 * reclaimable and unmovable allocations, we steal regardless of page size,
1913 * as fragmentation caused by those allocations polluting movable pageblocks
1914 * is worse than movable allocations stealing from unmovable and reclaimable
1917 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1920 * Leaving this order check is intended, although there is
1921 * relaxed order check in next check. The reason is that
1922 * we can actually steal whole pageblock if this condition met,
1923 * but, below check doesn't guarantee it and that is just heuristic
1924 * so could be changed anytime.
1926 if (order
>= pageblock_order
)
1929 if (order
>= pageblock_order
/ 2 ||
1930 start_mt
== MIGRATE_RECLAIMABLE
||
1931 start_mt
== MIGRATE_UNMOVABLE
||
1932 page_group_by_mobility_disabled
)
1939 * This function implements actual steal behaviour. If order is large enough,
1940 * we can steal whole pageblock. If not, we first move freepages in this
1941 * pageblock and check whether half of pages are moved or not. If half of
1942 * pages are moved, we can change migratetype of pageblock and permanently
1943 * use it's pages as requested migratetype in the future.
1945 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1948 unsigned int current_order
= page_order(page
);
1951 /* Take ownership for orders >= pageblock_order */
1952 if (current_order
>= pageblock_order
) {
1953 change_pageblock_range(page
, current_order
, start_type
);
1957 pages
= move_freepages_block(zone
, page
, start_type
);
1959 /* Claim the whole block if over half of it is free */
1960 if (pages
>= (1 << (pageblock_order
-1)) ||
1961 page_group_by_mobility_disabled
)
1962 set_pageblock_migratetype(page
, start_type
);
1966 * Check whether there is a suitable fallback freepage with requested order.
1967 * If only_stealable is true, this function returns fallback_mt only if
1968 * we can steal other freepages all together. This would help to reduce
1969 * fragmentation due to mixed migratetype pages in one pageblock.
1971 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1972 int migratetype
, bool only_stealable
, bool *can_steal
)
1977 if (area
->nr_free
== 0)
1982 fallback_mt
= fallbacks
[migratetype
][i
];
1983 if (fallback_mt
== MIGRATE_TYPES
)
1986 if (list_empty(&area
->free_list
[fallback_mt
]))
1989 if (can_steal_fallback(order
, migratetype
))
1992 if (!only_stealable
)
2003 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2004 * there are no empty page blocks that contain a page with a suitable order
2006 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2007 unsigned int alloc_order
)
2010 unsigned long max_managed
, flags
;
2013 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2014 * Check is race-prone but harmless.
2016 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2017 if (zone
->nr_reserved_highatomic
>= max_managed
)
2020 spin_lock_irqsave(&zone
->lock
, flags
);
2022 /* Recheck the nr_reserved_highatomic limit under the lock */
2023 if (zone
->nr_reserved_highatomic
>= max_managed
)
2027 mt
= get_pageblock_migratetype(page
);
2028 if (mt
!= MIGRATE_HIGHATOMIC
&&
2029 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
2030 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2031 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2032 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
2036 spin_unlock_irqrestore(&zone
->lock
, flags
);
2040 * Used when an allocation is about to fail under memory pressure. This
2041 * potentially hurts the reliability of high-order allocations when under
2042 * intense memory pressure but failed atomic allocations should be easier
2043 * to recover from than an OOM.
2045 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
2047 struct zonelist
*zonelist
= ac
->zonelist
;
2048 unsigned long flags
;
2054 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2056 /* Preserve at least one pageblock */
2057 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
2060 spin_lock_irqsave(&zone
->lock
, flags
);
2061 for (order
= 0; order
< MAX_ORDER
; order
++) {
2062 struct free_area
*area
= &(zone
->free_area
[order
]);
2064 page
= list_first_entry_or_null(
2065 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2071 * It should never happen but changes to locking could
2072 * inadvertently allow a per-cpu drain to add pages
2073 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2074 * and watch for underflows.
2076 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
2077 zone
->nr_reserved_highatomic
);
2080 * Convert to ac->migratetype and avoid the normal
2081 * pageblock stealing heuristics. Minimally, the caller
2082 * is doing the work and needs the pages. More
2083 * importantly, if the block was always converted to
2084 * MIGRATE_UNMOVABLE or another type then the number
2085 * of pageblocks that cannot be completely freed
2088 set_pageblock_migratetype(page
, ac
->migratetype
);
2089 move_freepages_block(zone
, page
, ac
->migratetype
);
2090 spin_unlock_irqrestore(&zone
->lock
, flags
);
2093 spin_unlock_irqrestore(&zone
->lock
, flags
);
2097 /* Remove an element from the buddy allocator from the fallback list */
2098 static inline struct page
*
2099 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
2101 struct free_area
*area
;
2102 unsigned int current_order
;
2107 /* Find the largest possible block of pages in the other list */
2108 for (current_order
= MAX_ORDER
-1;
2109 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
2111 area
= &(zone
->free_area
[current_order
]);
2112 fallback_mt
= find_suitable_fallback(area
, current_order
,
2113 start_migratetype
, false, &can_steal
);
2114 if (fallback_mt
== -1)
2117 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2120 steal_suitable_fallback(zone
, page
, start_migratetype
);
2122 /* Remove the page from the freelists */
2124 list_del(&page
->lru
);
2125 rmv_page_order(page
);
2127 expand(zone
, page
, order
, current_order
, area
,
2130 * The pcppage_migratetype may differ from pageblock's
2131 * migratetype depending on the decisions in
2132 * find_suitable_fallback(). This is OK as long as it does not
2133 * differ for MIGRATE_CMA pageblocks. Those can be used as
2134 * fallback only via special __rmqueue_cma_fallback() function
2136 set_pcppage_migratetype(page
, start_migratetype
);
2138 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2139 start_migratetype
, fallback_mt
);
2148 * Do the hard work of removing an element from the buddy allocator.
2149 * Call me with the zone->lock already held.
2151 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2156 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2157 if (unlikely(!page
)) {
2158 if (migratetype
== MIGRATE_MOVABLE
)
2159 page
= __rmqueue_cma_fallback(zone
, order
);
2162 page
= __rmqueue_fallback(zone
, order
, migratetype
);
2165 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2170 * Obtain a specified number of elements from the buddy allocator, all under
2171 * a single hold of the lock, for efficiency. Add them to the supplied list.
2172 * Returns the number of new pages which were placed at *list.
2174 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2175 unsigned long count
, struct list_head
*list
,
2176 int migratetype
, bool cold
)
2180 spin_lock(&zone
->lock
);
2181 for (i
= 0; i
< count
; ++i
) {
2182 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2183 if (unlikely(page
== NULL
))
2186 if (unlikely(check_pcp_refill(page
)))
2190 * Split buddy pages returned by expand() are received here
2191 * in physical page order. The page is added to the callers and
2192 * list and the list head then moves forward. From the callers
2193 * perspective, the linked list is ordered by page number in
2194 * some conditions. This is useful for IO devices that can
2195 * merge IO requests if the physical pages are ordered
2199 list_add(&page
->lru
, list
);
2201 list_add_tail(&page
->lru
, list
);
2203 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2204 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2207 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2208 spin_unlock(&zone
->lock
);
2214 * Called from the vmstat counter updater to drain pagesets of this
2215 * currently executing processor on remote nodes after they have
2218 * Note that this function must be called with the thread pinned to
2219 * a single processor.
2221 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2223 unsigned long flags
;
2224 int to_drain
, batch
;
2226 local_irq_save(flags
);
2227 batch
= READ_ONCE(pcp
->batch
);
2228 to_drain
= min(pcp
->count
, batch
);
2230 free_pcppages_bulk(zone
, to_drain
, pcp
);
2231 pcp
->count
-= to_drain
;
2233 local_irq_restore(flags
);
2238 * Drain pcplists of the indicated processor and zone.
2240 * The processor must either be the current processor and the
2241 * thread pinned to the current processor or a processor that
2244 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2246 unsigned long flags
;
2247 struct per_cpu_pageset
*pset
;
2248 struct per_cpu_pages
*pcp
;
2250 local_irq_save(flags
);
2251 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2255 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2258 local_irq_restore(flags
);
2262 * Drain pcplists of all zones on the indicated processor.
2264 * The processor must either be the current processor and the
2265 * thread pinned to the current processor or a processor that
2268 static void drain_pages(unsigned int cpu
)
2272 for_each_populated_zone(zone
) {
2273 drain_pages_zone(cpu
, zone
);
2278 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2280 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2281 * the single zone's pages.
2283 void drain_local_pages(struct zone
*zone
)
2285 int cpu
= smp_processor_id();
2288 drain_pages_zone(cpu
, zone
);
2294 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2296 * When zone parameter is non-NULL, spill just the single zone's pages.
2298 * Note that this code is protected against sending an IPI to an offline
2299 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2300 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2301 * nothing keeps CPUs from showing up after we populated the cpumask and
2302 * before the call to on_each_cpu_mask().
2304 void drain_all_pages(struct zone
*zone
)
2309 * Allocate in the BSS so we wont require allocation in
2310 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2312 static cpumask_t cpus_with_pcps
;
2315 * We don't care about racing with CPU hotplug event
2316 * as offline notification will cause the notified
2317 * cpu to drain that CPU pcps and on_each_cpu_mask
2318 * disables preemption as part of its processing
2320 for_each_online_cpu(cpu
) {
2321 struct per_cpu_pageset
*pcp
;
2323 bool has_pcps
= false;
2326 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2330 for_each_populated_zone(z
) {
2331 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2332 if (pcp
->pcp
.count
) {
2340 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2342 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2344 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2348 #ifdef CONFIG_HIBERNATION
2350 void mark_free_pages(struct zone
*zone
)
2352 unsigned long pfn
, max_zone_pfn
;
2353 unsigned long flags
;
2354 unsigned int order
, t
;
2357 if (zone_is_empty(zone
))
2360 spin_lock_irqsave(&zone
->lock
, flags
);
2362 max_zone_pfn
= zone_end_pfn(zone
);
2363 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2364 if (pfn_valid(pfn
)) {
2365 page
= pfn_to_page(pfn
);
2367 if (page_zone(page
) != zone
)
2370 if (!swsusp_page_is_forbidden(page
))
2371 swsusp_unset_page_free(page
);
2374 for_each_migratetype_order(order
, t
) {
2375 list_for_each_entry(page
,
2376 &zone
->free_area
[order
].free_list
[t
], lru
) {
2379 pfn
= page_to_pfn(page
);
2380 for (i
= 0; i
< (1UL << order
); i
++)
2381 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2384 spin_unlock_irqrestore(&zone
->lock
, flags
);
2386 #endif /* CONFIG_PM */
2389 * Free a 0-order page
2390 * cold == true ? free a cold page : free a hot page
2392 void free_hot_cold_page(struct page
*page
, bool cold
)
2394 struct zone
*zone
= page_zone(page
);
2395 struct per_cpu_pages
*pcp
;
2396 unsigned long flags
;
2397 unsigned long pfn
= page_to_pfn(page
);
2400 if (!free_pcp_prepare(page
))
2403 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2404 set_pcppage_migratetype(page
, migratetype
);
2405 local_irq_save(flags
);
2406 __count_vm_event(PGFREE
);
2409 * We only track unmovable, reclaimable and movable on pcp lists.
2410 * Free ISOLATE pages back to the allocator because they are being
2411 * offlined but treat RESERVE as movable pages so we can get those
2412 * areas back if necessary. Otherwise, we may have to free
2413 * excessively into the page allocator
2415 if (migratetype
>= MIGRATE_PCPTYPES
) {
2416 if (unlikely(is_migrate_isolate(migratetype
))) {
2417 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2420 migratetype
= MIGRATE_MOVABLE
;
2423 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2425 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2427 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2429 if (pcp
->count
>= pcp
->high
) {
2430 unsigned long batch
= READ_ONCE(pcp
->batch
);
2431 free_pcppages_bulk(zone
, batch
, pcp
);
2432 pcp
->count
-= batch
;
2436 local_irq_restore(flags
);
2440 * Free a list of 0-order pages
2442 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2444 struct page
*page
, *next
;
2446 list_for_each_entry_safe(page
, next
, list
, lru
) {
2447 trace_mm_page_free_batched(page
, cold
);
2448 free_hot_cold_page(page
, cold
);
2453 * split_page takes a non-compound higher-order page, and splits it into
2454 * n (1<<order) sub-pages: page[0..n]
2455 * Each sub-page must be freed individually.
2457 * Note: this is probably too low level an operation for use in drivers.
2458 * Please consult with lkml before using this in your driver.
2460 void split_page(struct page
*page
, unsigned int order
)
2464 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2465 VM_BUG_ON_PAGE(!page_count(page
), page
);
2467 #ifdef CONFIG_KMEMCHECK
2469 * Split shadow pages too, because free(page[0]) would
2470 * otherwise free the whole shadow.
2472 if (kmemcheck_page_is_tracked(page
))
2473 split_page(virt_to_page(page
[0].shadow
), order
);
2476 for (i
= 1; i
< (1 << order
); i
++)
2477 set_page_refcounted(page
+ i
);
2478 split_page_owner(page
, order
);
2480 EXPORT_SYMBOL_GPL(split_page
);
2482 int __isolate_free_page(struct page
*page
, unsigned int order
)
2484 unsigned long watermark
;
2488 BUG_ON(!PageBuddy(page
));
2490 zone
= page_zone(page
);
2491 mt
= get_pageblock_migratetype(page
);
2493 if (!is_migrate_isolate(mt
)) {
2494 /* Obey watermarks as if the page was being allocated */
2495 watermark
= low_wmark_pages(zone
) + (1 << order
);
2496 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2499 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2502 /* Remove page from free list */
2503 list_del(&page
->lru
);
2504 zone
->free_area
[order
].nr_free
--;
2505 rmv_page_order(page
);
2508 * Set the pageblock if the isolated page is at least half of a
2511 if (order
>= pageblock_order
- 1) {
2512 struct page
*endpage
= page
+ (1 << order
) - 1;
2513 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2514 int mt
= get_pageblock_migratetype(page
);
2515 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2516 set_pageblock_migratetype(page
,
2522 return 1UL << order
;
2526 * Update NUMA hit/miss statistics
2528 * Must be called with interrupts disabled.
2530 * When __GFP_OTHER_NODE is set assume the node of the preferred
2531 * zone is the local node. This is useful for daemons who allocate
2532 * memory on behalf of other processes.
2534 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
,
2538 int local_nid
= numa_node_id();
2539 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2541 if (unlikely(flags
& __GFP_OTHER_NODE
)) {
2542 local_stat
= NUMA_OTHER
;
2543 local_nid
= preferred_zone
->node
;
2546 if (z
->node
== local_nid
) {
2547 __inc_zone_state(z
, NUMA_HIT
);
2548 __inc_zone_state(z
, local_stat
);
2550 __inc_zone_state(z
, NUMA_MISS
);
2551 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2557 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2560 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2561 struct zone
*zone
, unsigned int order
,
2562 gfp_t gfp_flags
, unsigned int alloc_flags
,
2565 unsigned long flags
;
2567 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2569 if (likely(order
== 0)) {
2570 struct per_cpu_pages
*pcp
;
2571 struct list_head
*list
;
2573 local_irq_save(flags
);
2575 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2576 list
= &pcp
->lists
[migratetype
];
2577 if (list_empty(list
)) {
2578 pcp
->count
+= rmqueue_bulk(zone
, 0,
2581 if (unlikely(list_empty(list
)))
2586 page
= list_last_entry(list
, struct page
, lru
);
2588 page
= list_first_entry(list
, struct page
, lru
);
2590 list_del(&page
->lru
);
2593 } while (check_new_pcp(page
));
2596 * We most definitely don't want callers attempting to
2597 * allocate greater than order-1 page units with __GFP_NOFAIL.
2599 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2600 spin_lock_irqsave(&zone
->lock
, flags
);
2604 if (alloc_flags
& ALLOC_HARDER
) {
2605 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2607 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2610 page
= __rmqueue(zone
, order
, migratetype
);
2611 } while (page
&& check_new_pages(page
, order
));
2612 spin_unlock(&zone
->lock
);
2615 __mod_zone_freepage_state(zone
, -(1 << order
),
2616 get_pcppage_migratetype(page
));
2619 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2620 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2621 local_irq_restore(flags
);
2623 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2627 local_irq_restore(flags
);
2631 #ifdef CONFIG_FAIL_PAGE_ALLOC
2634 struct fault_attr attr
;
2636 bool ignore_gfp_highmem
;
2637 bool ignore_gfp_reclaim
;
2639 } fail_page_alloc
= {
2640 .attr
= FAULT_ATTR_INITIALIZER
,
2641 .ignore_gfp_reclaim
= true,
2642 .ignore_gfp_highmem
= true,
2646 static int __init
setup_fail_page_alloc(char *str
)
2648 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2650 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2652 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2654 if (order
< fail_page_alloc
.min_order
)
2656 if (gfp_mask
& __GFP_NOFAIL
)
2658 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2660 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2661 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2664 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2667 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2669 static int __init
fail_page_alloc_debugfs(void)
2671 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2674 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2675 &fail_page_alloc
.attr
);
2677 return PTR_ERR(dir
);
2679 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2680 &fail_page_alloc
.ignore_gfp_reclaim
))
2682 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2683 &fail_page_alloc
.ignore_gfp_highmem
))
2685 if (!debugfs_create_u32("min-order", mode
, dir
,
2686 &fail_page_alloc
.min_order
))
2691 debugfs_remove_recursive(dir
);
2696 late_initcall(fail_page_alloc_debugfs
);
2698 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2700 #else /* CONFIG_FAIL_PAGE_ALLOC */
2702 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2707 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2710 * Return true if free base pages are above 'mark'. For high-order checks it
2711 * will return true of the order-0 watermark is reached and there is at least
2712 * one free page of a suitable size. Checking now avoids taking the zone lock
2713 * to check in the allocation paths if no pages are free.
2715 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2716 int classzone_idx
, unsigned int alloc_flags
,
2721 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2723 /* free_pages may go negative - that's OK */
2724 free_pages
-= (1 << order
) - 1;
2726 if (alloc_flags
& ALLOC_HIGH
)
2730 * If the caller does not have rights to ALLOC_HARDER then subtract
2731 * the high-atomic reserves. This will over-estimate the size of the
2732 * atomic reserve but it avoids a search.
2734 if (likely(!alloc_harder
))
2735 free_pages
-= z
->nr_reserved_highatomic
;
2740 /* If allocation can't use CMA areas don't use free CMA pages */
2741 if (!(alloc_flags
& ALLOC_CMA
))
2742 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2746 * Check watermarks for an order-0 allocation request. If these
2747 * are not met, then a high-order request also cannot go ahead
2748 * even if a suitable page happened to be free.
2750 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2753 /* If this is an order-0 request then the watermark is fine */
2757 /* For a high-order request, check at least one suitable page is free */
2758 for (o
= order
; o
< MAX_ORDER
; o
++) {
2759 struct free_area
*area
= &z
->free_area
[o
];
2768 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2769 if (!list_empty(&area
->free_list
[mt
]))
2774 if ((alloc_flags
& ALLOC_CMA
) &&
2775 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2783 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2784 int classzone_idx
, unsigned int alloc_flags
)
2786 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2787 zone_page_state(z
, NR_FREE_PAGES
));
2790 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
2791 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
2793 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2797 /* If allocation can't use CMA areas don't use free CMA pages */
2798 if (!(alloc_flags
& ALLOC_CMA
))
2799 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2803 * Fast check for order-0 only. If this fails then the reserves
2804 * need to be calculated. There is a corner case where the check
2805 * passes but only the high-order atomic reserve are free. If
2806 * the caller is !atomic then it'll uselessly search the free
2807 * list. That corner case is then slower but it is harmless.
2809 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
2812 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2816 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2817 unsigned long mark
, int classzone_idx
)
2819 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2821 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2822 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2824 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2829 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2831 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2834 #else /* CONFIG_NUMA */
2835 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2839 #endif /* CONFIG_NUMA */
2842 * get_page_from_freelist goes through the zonelist trying to allocate
2845 static struct page
*
2846 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2847 const struct alloc_context
*ac
)
2849 struct zoneref
*z
= ac
->preferred_zoneref
;
2851 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
2854 * Scan zonelist, looking for a zone with enough free.
2855 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2857 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
2862 if (cpusets_enabled() &&
2863 (alloc_flags
& ALLOC_CPUSET
) &&
2864 !__cpuset_zone_allowed(zone
, gfp_mask
))
2867 * When allocating a page cache page for writing, we
2868 * want to get it from a node that is within its dirty
2869 * limit, such that no single node holds more than its
2870 * proportional share of globally allowed dirty pages.
2871 * The dirty limits take into account the node's
2872 * lowmem reserves and high watermark so that kswapd
2873 * should be able to balance it without having to
2874 * write pages from its LRU list.
2876 * XXX: For now, allow allocations to potentially
2877 * exceed the per-node dirty limit in the slowpath
2878 * (spread_dirty_pages unset) before going into reclaim,
2879 * which is important when on a NUMA setup the allowed
2880 * nodes are together not big enough to reach the
2881 * global limit. The proper fix for these situations
2882 * will require awareness of nodes in the
2883 * dirty-throttling and the flusher threads.
2885 if (ac
->spread_dirty_pages
) {
2886 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
2889 if (!node_dirty_ok(zone
->zone_pgdat
)) {
2890 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
2895 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2896 if (!zone_watermark_fast(zone
, order
, mark
,
2897 ac_classzone_idx(ac
), alloc_flags
)) {
2900 /* Checked here to keep the fast path fast */
2901 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2902 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2905 if (node_reclaim_mode
== 0 ||
2906 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
2909 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
2911 case NODE_RECLAIM_NOSCAN
:
2914 case NODE_RECLAIM_FULL
:
2915 /* scanned but unreclaimable */
2918 /* did we reclaim enough */
2919 if (zone_watermark_ok(zone
, order
, mark
,
2920 ac_classzone_idx(ac
), alloc_flags
))
2928 page
= buffered_rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
2929 gfp_mask
, alloc_flags
, ac
->migratetype
);
2931 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
2934 * If this is a high-order atomic allocation then check
2935 * if the pageblock should be reserved for the future
2937 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2938 reserve_highatomic_pageblock(page
, zone
, order
);
2948 * Large machines with many possible nodes should not always dump per-node
2949 * meminfo in irq context.
2951 static inline bool should_suppress_show_mem(void)
2956 ret
= in_interrupt();
2961 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2962 DEFAULT_RATELIMIT_INTERVAL
,
2963 DEFAULT_RATELIMIT_BURST
);
2965 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2967 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2969 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2970 debug_guardpage_minorder() > 0)
2974 * This documents exceptions given to allocations in certain
2975 * contexts that are allowed to allocate outside current's set
2978 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2979 if (test_thread_flag(TIF_MEMDIE
) ||
2980 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2981 filter
&= ~SHOW_MEM_FILTER_NODES
;
2982 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2983 filter
&= ~SHOW_MEM_FILTER_NODES
;
2986 struct va_format vaf
;
2989 va_start(args
, fmt
);
2994 pr_warn("%pV", &vaf
);
2999 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3000 current
->comm
, order
, gfp_mask
, &gfp_mask
);
3002 if (!should_suppress_show_mem())
3006 static inline struct page
*
3007 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3008 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3010 struct oom_control oc
= {
3011 .zonelist
= ac
->zonelist
,
3012 .nodemask
= ac
->nodemask
,
3014 .gfp_mask
= gfp_mask
,
3019 *did_some_progress
= 0;
3022 * Acquire the oom lock. If that fails, somebody else is
3023 * making progress for us.
3025 if (!mutex_trylock(&oom_lock
)) {
3026 *did_some_progress
= 1;
3027 schedule_timeout_uninterruptible(1);
3032 * Go through the zonelist yet one more time, keep very high watermark
3033 * here, this is only to catch a parallel oom killing, we must fail if
3034 * we're still under heavy pressure.
3036 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3037 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3041 if (!(gfp_mask
& __GFP_NOFAIL
)) {
3042 /* Coredumps can quickly deplete all memory reserves */
3043 if (current
->flags
& PF_DUMPCORE
)
3045 /* The OOM killer will not help higher order allocs */
3046 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3048 /* The OOM killer does not needlessly kill tasks for lowmem */
3049 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3051 if (pm_suspended_storage())
3054 * XXX: GFP_NOFS allocations should rather fail than rely on
3055 * other request to make a forward progress.
3056 * We are in an unfortunate situation where out_of_memory cannot
3057 * do much for this context but let's try it to at least get
3058 * access to memory reserved if the current task is killed (see
3059 * out_of_memory). Once filesystems are ready to handle allocation
3060 * failures more gracefully we should just bail out here.
3063 /* The OOM killer may not free memory on a specific node */
3064 if (gfp_mask
& __GFP_THISNODE
)
3067 /* Exhausted what can be done so it's blamo time */
3068 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3069 *did_some_progress
= 1;
3071 if (gfp_mask
& __GFP_NOFAIL
) {
3072 page
= get_page_from_freelist(gfp_mask
, order
,
3073 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
3075 * fallback to ignore cpuset restriction if our nodes
3079 page
= get_page_from_freelist(gfp_mask
, order
,
3080 ALLOC_NO_WATERMARKS
, ac
);
3084 mutex_unlock(&oom_lock
);
3090 * Maximum number of compaction retries wit a progress before OOM
3091 * killer is consider as the only way to move forward.
3093 #define MAX_COMPACT_RETRIES 16
3095 #ifdef CONFIG_COMPACTION
3096 /* Try memory compaction for high-order allocations before reclaim */
3097 static struct page
*
3098 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3099 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3100 enum migrate_mode mode
, enum compact_result
*compact_result
)
3103 int contended_compaction
;
3108 current
->flags
|= PF_MEMALLOC
;
3109 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3110 mode
, &contended_compaction
);
3111 current
->flags
&= ~PF_MEMALLOC
;
3113 if (*compact_result
<= COMPACT_INACTIVE
)
3117 * At least in one zone compaction wasn't deferred or skipped, so let's
3118 * count a compaction stall
3120 count_vm_event(COMPACTSTALL
);
3122 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3125 struct zone
*zone
= page_zone(page
);
3127 zone
->compact_blockskip_flush
= false;
3128 compaction_defer_reset(zone
, order
, true);
3129 count_vm_event(COMPACTSUCCESS
);
3134 * It's bad if compaction run occurs and fails. The most likely reason
3135 * is that pages exist, but not enough to satisfy watermarks.
3137 count_vm_event(COMPACTFAIL
);
3140 * In all zones where compaction was attempted (and not
3141 * deferred or skipped), lock contention has been detected.
3142 * For THP allocation we do not want to disrupt the others
3143 * so we fallback to base pages instead.
3145 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3146 *compact_result
= COMPACT_CONTENDED
;
3149 * If compaction was aborted due to need_resched(), we do not
3150 * want to further increase allocation latency, unless it is
3151 * khugepaged trying to collapse.
3153 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3154 && !(current
->flags
& PF_KTHREAD
))
3155 *compact_result
= COMPACT_CONTENDED
;
3163 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3164 enum compact_result compact_result
, enum migrate_mode
*migrate_mode
,
3165 int compaction_retries
)
3167 int max_retries
= MAX_COMPACT_RETRIES
;
3173 * compaction considers all the zone as desperately out of memory
3174 * so it doesn't really make much sense to retry except when the
3175 * failure could be caused by weak migration mode.
3177 if (compaction_failed(compact_result
)) {
3178 if (*migrate_mode
== MIGRATE_ASYNC
) {
3179 *migrate_mode
= MIGRATE_SYNC_LIGHT
;
3186 * make sure the compaction wasn't deferred or didn't bail out early
3187 * due to locks contention before we declare that we should give up.
3188 * But do not retry if the given zonelist is not suitable for
3191 if (compaction_withdrawn(compact_result
))
3192 return compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3195 * !costly requests are much more important than __GFP_REPEAT
3196 * costly ones because they are de facto nofail and invoke OOM
3197 * killer to move on while costly can fail and users are ready
3198 * to cope with that. 1/4 retries is rather arbitrary but we
3199 * would need much more detailed feedback from compaction to
3200 * make a better decision.
3202 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3204 if (compaction_retries
<= max_retries
)
3210 static inline struct page
*
3211 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3212 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3213 enum migrate_mode mode
, enum compact_result
*compact_result
)
3215 *compact_result
= COMPACT_SKIPPED
;
3220 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3221 enum compact_result compact_result
,
3222 enum migrate_mode
*migrate_mode
,
3223 int compaction_retries
)
3228 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3232 * There are setups with compaction disabled which would prefer to loop
3233 * inside the allocator rather than hit the oom killer prematurely.
3234 * Let's give them a good hope and keep retrying while the order-0
3235 * watermarks are OK.
3237 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3239 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3240 ac_classzone_idx(ac
), alloc_flags
))
3245 #endif /* CONFIG_COMPACTION */
3247 /* Perform direct synchronous page reclaim */
3249 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3250 const struct alloc_context
*ac
)
3252 struct reclaim_state reclaim_state
;
3257 /* We now go into synchronous reclaim */
3258 cpuset_memory_pressure_bump();
3259 current
->flags
|= PF_MEMALLOC
;
3260 lockdep_set_current_reclaim_state(gfp_mask
);
3261 reclaim_state
.reclaimed_slab
= 0;
3262 current
->reclaim_state
= &reclaim_state
;
3264 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3267 current
->reclaim_state
= NULL
;
3268 lockdep_clear_current_reclaim_state();
3269 current
->flags
&= ~PF_MEMALLOC
;
3276 /* The really slow allocator path where we enter direct reclaim */
3277 static inline struct page
*
3278 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3279 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3280 unsigned long *did_some_progress
)
3282 struct page
*page
= NULL
;
3283 bool drained
= false;
3285 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3286 if (unlikely(!(*did_some_progress
)))
3290 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3293 * If an allocation failed after direct reclaim, it could be because
3294 * pages are pinned on the per-cpu lists or in high alloc reserves.
3295 * Shrink them them and try again
3297 if (!page
&& !drained
) {
3298 unreserve_highatomic_pageblock(ac
);
3299 drain_all_pages(NULL
);
3307 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3311 pg_data_t
*last_pgdat
= NULL
;
3313 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3314 ac
->high_zoneidx
, ac
->nodemask
) {
3315 if (last_pgdat
!= zone
->zone_pgdat
)
3316 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3317 last_pgdat
= zone
->zone_pgdat
;
3321 static inline unsigned int
3322 gfp_to_alloc_flags(gfp_t gfp_mask
)
3324 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3326 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3327 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3330 * The caller may dip into page reserves a bit more if the caller
3331 * cannot run direct reclaim, or if the caller has realtime scheduling
3332 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3333 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3335 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3337 if (gfp_mask
& __GFP_ATOMIC
) {
3339 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3340 * if it can't schedule.
3342 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3343 alloc_flags
|= ALLOC_HARDER
;
3345 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3346 * comment for __cpuset_node_allowed().
3348 alloc_flags
&= ~ALLOC_CPUSET
;
3349 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3350 alloc_flags
|= ALLOC_HARDER
;
3353 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3354 alloc_flags
|= ALLOC_CMA
;
3359 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3361 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3364 if (gfp_mask
& __GFP_MEMALLOC
)
3366 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3368 if (!in_interrupt() &&
3369 ((current
->flags
& PF_MEMALLOC
) ||
3370 unlikely(test_thread_flag(TIF_MEMDIE
))))
3376 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3378 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3382 * Maximum number of reclaim retries without any progress before OOM killer
3383 * is consider as the only way to move forward.
3385 #define MAX_RECLAIM_RETRIES 16
3388 * Checks whether it makes sense to retry the reclaim to make a forward progress
3389 * for the given allocation request.
3390 * The reclaim feedback represented by did_some_progress (any progress during
3391 * the last reclaim round) and no_progress_loops (number of reclaim rounds without
3392 * any progress in a row) is considered as well as the reclaimable pages on the
3393 * applicable zone list (with a backoff mechanism which is a function of
3394 * no_progress_loops).
3396 * Returns true if a retry is viable or false to enter the oom path.
3399 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3400 struct alloc_context
*ac
, int alloc_flags
,
3401 bool did_some_progress
, int no_progress_loops
)
3407 * Make sure we converge to OOM if we cannot make any progress
3408 * several times in the row.
3410 if (no_progress_loops
> MAX_RECLAIM_RETRIES
)
3414 * Keep reclaiming pages while there is a chance this will lead
3415 * somewhere. If none of the target zones can satisfy our allocation
3416 * request even if all reclaimable pages are considered then we are
3417 * screwed and have to go OOM.
3419 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3421 unsigned long available
;
3422 unsigned long reclaimable
;
3424 available
= reclaimable
= zone_reclaimable_pages(zone
);
3425 available
-= DIV_ROUND_UP(no_progress_loops
* available
,
3426 MAX_RECLAIM_RETRIES
);
3427 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3430 * Would the allocation succeed if we reclaimed the whole
3433 if (__zone_watermark_ok(zone
, order
, min_wmark_pages(zone
),
3434 ac_classzone_idx(ac
), alloc_flags
, available
)) {
3436 * If we didn't make any progress and have a lot of
3437 * dirty + writeback pages then we should wait for
3438 * an IO to complete to slow down the reclaim and
3439 * prevent from pre mature OOM
3441 if (!did_some_progress
) {
3442 unsigned long write_pending
;
3444 write_pending
= zone_page_state_snapshot(zone
,
3445 NR_ZONE_WRITE_PENDING
);
3447 if (2 * write_pending
> reclaimable
) {
3448 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3454 * Memory allocation/reclaim might be called from a WQ
3455 * context and the current implementation of the WQ
3456 * concurrency control doesn't recognize that
3457 * a particular WQ is congested if the worker thread is
3458 * looping without ever sleeping. Therefore we have to
3459 * do a short sleep here rather than calling
3462 if (current
->flags
& PF_WQ_WORKER
)
3463 schedule_timeout_uninterruptible(1);
3474 static inline struct page
*
3475 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3476 struct alloc_context
*ac
)
3478 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3479 struct page
*page
= NULL
;
3480 unsigned int alloc_flags
;
3481 unsigned long did_some_progress
;
3482 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3483 enum compact_result compact_result
;
3484 int compaction_retries
= 0;
3485 int no_progress_loops
= 0;
3488 * In the slowpath, we sanity check order to avoid ever trying to
3489 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3490 * be using allocators in order of preference for an area that is
3493 if (order
>= MAX_ORDER
) {
3494 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3499 * We also sanity check to catch abuse of atomic reserves being used by
3500 * callers that are not in atomic context.
3502 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3503 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3504 gfp_mask
&= ~__GFP_ATOMIC
;
3507 * The fast path uses conservative alloc_flags to succeed only until
3508 * kswapd needs to be woken up, and to avoid the cost of setting up
3509 * alloc_flags precisely. So we do that now.
3511 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3514 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3515 wake_all_kswapds(order
, ac
);
3518 * Reset the zonelist iterators if memory policies can be ignored.
3519 * These allocations are high priority and system rather than user
3522 if (!(alloc_flags
& ALLOC_CPUSET
) || gfp_pfmemalloc_allowed(gfp_mask
)) {
3523 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3524 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3525 ac
->high_zoneidx
, ac
->nodemask
);
3528 /* This is the last chance, in general, before the goto nopage. */
3529 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3533 /* Allocate without watermarks if the context allows */
3534 if (gfp_pfmemalloc_allowed(gfp_mask
)) {
3536 page
= get_page_from_freelist(gfp_mask
, order
,
3537 ALLOC_NO_WATERMARKS
, ac
);
3542 /* Caller is not willing to reclaim, we can't balance anything */
3543 if (!can_direct_reclaim
) {
3545 * All existing users of the __GFP_NOFAIL are blockable, so warn
3546 * of any new users that actually allow this type of allocation
3549 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3553 /* Avoid recursion of direct reclaim */
3554 if (current
->flags
& PF_MEMALLOC
) {
3556 * __GFP_NOFAIL request from this context is rather bizarre
3557 * because we cannot reclaim anything and only can loop waiting
3558 * for somebody to do a work for us.
3560 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3567 /* Avoid allocations with no watermarks from looping endlessly */
3568 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3572 * Try direct compaction. The first pass is asynchronous. Subsequent
3573 * attempts after direct reclaim are synchronous
3575 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3581 /* Checks for THP-specific high-order allocations */
3582 if (is_thp_gfp_mask(gfp_mask
)) {
3584 * If compaction is deferred for high-order allocations, it is
3585 * because sync compaction recently failed. If this is the case
3586 * and the caller requested a THP allocation, we do not want
3587 * to heavily disrupt the system, so we fail the allocation
3588 * instead of entering direct reclaim.
3590 if (compact_result
== COMPACT_DEFERRED
)
3594 * Compaction is contended so rather back off than cause
3597 if(compact_result
== COMPACT_CONTENDED
)
3601 if (order
&& compaction_made_progress(compact_result
))
3602 compaction_retries
++;
3604 /* Try direct reclaim and then allocating */
3605 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3606 &did_some_progress
);
3610 /* Do not loop if specifically requested */
3611 if (gfp_mask
& __GFP_NORETRY
)
3615 * Do not retry costly high order allocations unless they are
3618 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_REPEAT
))
3622 * Costly allocations might have made a progress but this doesn't mean
3623 * their order will become available due to high fragmentation so
3624 * always increment the no progress counter for them
3626 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3627 no_progress_loops
= 0;
3629 no_progress_loops
++;
3631 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3632 did_some_progress
> 0, no_progress_loops
))
3636 * It doesn't make any sense to retry for the compaction if the order-0
3637 * reclaim is not able to make any progress because the current
3638 * implementation of the compaction depends on the sufficient amount
3639 * of free memory (see __compaction_suitable)
3641 if (did_some_progress
> 0 &&
3642 should_compact_retry(ac
, order
, alloc_flags
,
3643 compact_result
, &migration_mode
,
3644 compaction_retries
))
3647 /* Reclaim has failed us, start killing things */
3648 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3652 /* Retry as long as the OOM killer is making progress */
3653 if (did_some_progress
) {
3654 no_progress_loops
= 0;
3660 * High-order allocations do not necessarily loop after direct reclaim
3661 * and reclaim/compaction depends on compaction being called after
3662 * reclaim so call directly if necessary.
3663 * It can become very expensive to allocate transparent hugepages at
3664 * fault, so use asynchronous memory compaction for THP unless it is
3665 * khugepaged trying to collapse. All other requests should tolerate
3666 * at least light sync migration.
3668 if (is_thp_gfp_mask(gfp_mask
) && !(current
->flags
& PF_KTHREAD
))
3669 migration_mode
= MIGRATE_ASYNC
;
3671 migration_mode
= MIGRATE_SYNC_LIGHT
;
3672 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3678 warn_alloc_failed(gfp_mask
, order
, NULL
);
3684 * This is the 'heart' of the zoned buddy allocator.
3687 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3688 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3691 unsigned int cpuset_mems_cookie
;
3692 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
3693 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
3694 struct alloc_context ac
= {
3695 .high_zoneidx
= gfp_zone(gfp_mask
),
3696 .zonelist
= zonelist
,
3697 .nodemask
= nodemask
,
3698 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3701 if (cpusets_enabled()) {
3702 alloc_mask
|= __GFP_HARDWALL
;
3703 alloc_flags
|= ALLOC_CPUSET
;
3705 ac
.nodemask
= &cpuset_current_mems_allowed
;
3708 gfp_mask
&= gfp_allowed_mask
;
3710 lockdep_trace_alloc(gfp_mask
);
3712 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3714 if (should_fail_alloc_page(gfp_mask
, order
))
3718 * Check the zones suitable for the gfp_mask contain at least one
3719 * valid zone. It's possible to have an empty zonelist as a result
3720 * of __GFP_THISNODE and a memoryless node
3722 if (unlikely(!zonelist
->_zonerefs
->zone
))
3725 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3726 alloc_flags
|= ALLOC_CMA
;
3729 cpuset_mems_cookie
= read_mems_allowed_begin();
3731 /* Dirty zone balancing only done in the fast path */
3732 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3735 * The preferred zone is used for statistics but crucially it is
3736 * also used as the starting point for the zonelist iterator. It
3737 * may get reset for allocations that ignore memory policies.
3739 ac
.preferred_zoneref
= first_zones_zonelist(ac
.zonelist
,
3740 ac
.high_zoneidx
, ac
.nodemask
);
3741 if (!ac
.preferred_zoneref
) {
3746 /* First allocation attempt */
3747 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3752 * Runtime PM, block IO and its error handling path can deadlock
3753 * because I/O on the device might not complete.
3755 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3756 ac
.spread_dirty_pages
= false;
3759 * Restore the original nodemask if it was potentially replaced with
3760 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
3762 if (cpusets_enabled())
3763 ac
.nodemask
= nodemask
;
3764 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3768 * When updating a task's mems_allowed, it is possible to race with
3769 * parallel threads in such a way that an allocation can fail while
3770 * the mask is being updated. If a page allocation is about to fail,
3771 * check if the cpuset changed during allocation and if so, retry.
3773 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
))) {
3774 alloc_mask
= gfp_mask
;
3779 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
) {
3780 if (unlikely(memcg_kmem_charge(page
, gfp_mask
, order
))) {
3781 __free_pages(page
, order
);
3784 __SetPageKmemcg(page
);
3787 if (kmemcheck_enabled
&& page
)
3788 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3790 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3794 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3797 * Common helper functions.
3799 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3804 * __get_free_pages() returns a 32-bit address, which cannot represent
3807 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3809 page
= alloc_pages(gfp_mask
, order
);
3812 return (unsigned long) page_address(page
);
3814 EXPORT_SYMBOL(__get_free_pages
);
3816 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3818 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3820 EXPORT_SYMBOL(get_zeroed_page
);
3822 void __free_pages(struct page
*page
, unsigned int order
)
3824 if (put_page_testzero(page
)) {
3826 free_hot_cold_page(page
, false);
3828 __free_pages_ok(page
, order
);
3832 EXPORT_SYMBOL(__free_pages
);
3834 void free_pages(unsigned long addr
, unsigned int order
)
3837 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3838 __free_pages(virt_to_page((void *)addr
), order
);
3842 EXPORT_SYMBOL(free_pages
);
3846 * An arbitrary-length arbitrary-offset area of memory which resides
3847 * within a 0 or higher order page. Multiple fragments within that page
3848 * are individually refcounted, in the page's reference counter.
3850 * The page_frag functions below provide a simple allocation framework for
3851 * page fragments. This is used by the network stack and network device
3852 * drivers to provide a backing region of memory for use as either an
3853 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3855 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3858 struct page
*page
= NULL
;
3859 gfp_t gfp
= gfp_mask
;
3861 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3862 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3864 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3865 PAGE_FRAG_CACHE_MAX_ORDER
);
3866 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3868 if (unlikely(!page
))
3869 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3871 nc
->va
= page
? page_address(page
) : NULL
;
3876 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3877 unsigned int fragsz
, gfp_t gfp_mask
)
3879 unsigned int size
= PAGE_SIZE
;
3883 if (unlikely(!nc
->va
)) {
3885 page
= __page_frag_refill(nc
, gfp_mask
);
3889 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3890 /* if size can vary use size else just use PAGE_SIZE */
3893 /* Even if we own the page, we do not use atomic_set().
3894 * This would break get_page_unless_zero() users.
3896 page_ref_add(page
, size
- 1);
3898 /* reset page count bias and offset to start of new frag */
3899 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3900 nc
->pagecnt_bias
= size
;
3904 offset
= nc
->offset
- fragsz
;
3905 if (unlikely(offset
< 0)) {
3906 page
= virt_to_page(nc
->va
);
3908 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3911 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3912 /* if size can vary use size else just use PAGE_SIZE */
3915 /* OK, page count is 0, we can safely set it */
3916 set_page_count(page
, size
);
3918 /* reset page count bias and offset to start of new frag */
3919 nc
->pagecnt_bias
= size
;
3920 offset
= size
- fragsz
;
3924 nc
->offset
= offset
;
3926 return nc
->va
+ offset
;
3928 EXPORT_SYMBOL(__alloc_page_frag
);
3931 * Frees a page fragment allocated out of either a compound or order 0 page.
3933 void __free_page_frag(void *addr
)
3935 struct page
*page
= virt_to_head_page(addr
);
3937 if (unlikely(put_page_testzero(page
)))
3938 __free_pages_ok(page
, compound_order(page
));
3940 EXPORT_SYMBOL(__free_page_frag
);
3942 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3946 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3947 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3949 split_page(virt_to_page((void *)addr
), order
);
3950 while (used
< alloc_end
) {
3955 return (void *)addr
;
3959 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3960 * @size: the number of bytes to allocate
3961 * @gfp_mask: GFP flags for the allocation
3963 * This function is similar to alloc_pages(), except that it allocates the
3964 * minimum number of pages to satisfy the request. alloc_pages() can only
3965 * allocate memory in power-of-two pages.
3967 * This function is also limited by MAX_ORDER.
3969 * Memory allocated by this function must be released by free_pages_exact().
3971 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3973 unsigned int order
= get_order(size
);
3976 addr
= __get_free_pages(gfp_mask
, order
);
3977 return make_alloc_exact(addr
, order
, size
);
3979 EXPORT_SYMBOL(alloc_pages_exact
);
3982 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3984 * @nid: the preferred node ID where memory should be allocated
3985 * @size: the number of bytes to allocate
3986 * @gfp_mask: GFP flags for the allocation
3988 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3991 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3993 unsigned int order
= get_order(size
);
3994 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3997 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4001 * free_pages_exact - release memory allocated via alloc_pages_exact()
4002 * @virt: the value returned by alloc_pages_exact.
4003 * @size: size of allocation, same value as passed to alloc_pages_exact().
4005 * Release the memory allocated by a previous call to alloc_pages_exact.
4007 void free_pages_exact(void *virt
, size_t size
)
4009 unsigned long addr
= (unsigned long)virt
;
4010 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4012 while (addr
< end
) {
4017 EXPORT_SYMBOL(free_pages_exact
);
4020 * nr_free_zone_pages - count number of pages beyond high watermark
4021 * @offset: The zone index of the highest zone
4023 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4024 * high watermark within all zones at or below a given zone index. For each
4025 * zone, the number of pages is calculated as:
4026 * managed_pages - high_pages
4028 static unsigned long nr_free_zone_pages(int offset
)
4033 /* Just pick one node, since fallback list is circular */
4034 unsigned long sum
= 0;
4036 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4038 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4039 unsigned long size
= zone
->managed_pages
;
4040 unsigned long high
= high_wmark_pages(zone
);
4049 * nr_free_buffer_pages - count number of pages beyond high watermark
4051 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4052 * watermark within ZONE_DMA and ZONE_NORMAL.
4054 unsigned long nr_free_buffer_pages(void)
4056 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4058 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4061 * nr_free_pagecache_pages - count number of pages beyond high watermark
4063 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4064 * high watermark within all zones.
4066 unsigned long nr_free_pagecache_pages(void)
4068 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4071 static inline void show_node(struct zone
*zone
)
4073 if (IS_ENABLED(CONFIG_NUMA
))
4074 printk("Node %d ", zone_to_nid(zone
));
4077 long si_mem_available(void)
4080 unsigned long pagecache
;
4081 unsigned long wmark_low
= 0;
4082 unsigned long pages
[NR_LRU_LISTS
];
4086 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4087 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
4090 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4093 * Estimate the amount of memory available for userspace allocations,
4094 * without causing swapping.
4096 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4099 * Not all the page cache can be freed, otherwise the system will
4100 * start swapping. Assume at least half of the page cache, or the
4101 * low watermark worth of cache, needs to stay.
4103 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4104 pagecache
-= min(pagecache
/ 2, wmark_low
);
4105 available
+= pagecache
;
4108 * Part of the reclaimable slab consists of items that are in use,
4109 * and cannot be freed. Cap this estimate at the low watermark.
4111 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4112 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4118 EXPORT_SYMBOL_GPL(si_mem_available
);
4120 void si_meminfo(struct sysinfo
*val
)
4122 val
->totalram
= totalram_pages
;
4123 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4124 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4125 val
->bufferram
= nr_blockdev_pages();
4126 val
->totalhigh
= totalhigh_pages
;
4127 val
->freehigh
= nr_free_highpages();
4128 val
->mem_unit
= PAGE_SIZE
;
4131 EXPORT_SYMBOL(si_meminfo
);
4134 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4136 int zone_type
; /* needs to be signed */
4137 unsigned long managed_pages
= 0;
4138 unsigned long managed_highpages
= 0;
4139 unsigned long free_highpages
= 0;
4140 pg_data_t
*pgdat
= NODE_DATA(nid
);
4142 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4143 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4144 val
->totalram
= managed_pages
;
4145 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4146 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4147 #ifdef CONFIG_HIGHMEM
4148 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4149 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4151 if (is_highmem(zone
)) {
4152 managed_highpages
+= zone
->managed_pages
;
4153 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4156 val
->totalhigh
= managed_highpages
;
4157 val
->freehigh
= free_highpages
;
4159 val
->totalhigh
= managed_highpages
;
4160 val
->freehigh
= free_highpages
;
4162 val
->mem_unit
= PAGE_SIZE
;
4167 * Determine whether the node should be displayed or not, depending on whether
4168 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4170 bool skip_free_areas_node(unsigned int flags
, int nid
)
4173 unsigned int cpuset_mems_cookie
;
4175 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4179 cpuset_mems_cookie
= read_mems_allowed_begin();
4180 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
4181 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
4186 #define K(x) ((x) << (PAGE_SHIFT-10))
4188 static void show_migration_types(unsigned char type
)
4190 static const char types
[MIGRATE_TYPES
] = {
4191 [MIGRATE_UNMOVABLE
] = 'U',
4192 [MIGRATE_MOVABLE
] = 'M',
4193 [MIGRATE_RECLAIMABLE
] = 'E',
4194 [MIGRATE_HIGHATOMIC
] = 'H',
4196 [MIGRATE_CMA
] = 'C',
4198 #ifdef CONFIG_MEMORY_ISOLATION
4199 [MIGRATE_ISOLATE
] = 'I',
4202 char tmp
[MIGRATE_TYPES
+ 1];
4206 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4207 if (type
& (1 << i
))
4212 printk("(%s) ", tmp
);
4216 * Show free area list (used inside shift_scroll-lock stuff)
4217 * We also calculate the percentage fragmentation. We do this by counting the
4218 * memory on each free list with the exception of the first item on the list.
4221 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4224 void show_free_areas(unsigned int filter
)
4226 unsigned long free_pcp
= 0;
4231 for_each_populated_zone(zone
) {
4232 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4235 for_each_online_cpu(cpu
)
4236 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4239 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4240 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4241 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4242 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4243 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4244 " free:%lu free_pcp:%lu free_cma:%lu\n",
4245 global_node_page_state(NR_ACTIVE_ANON
),
4246 global_node_page_state(NR_INACTIVE_ANON
),
4247 global_node_page_state(NR_ISOLATED_ANON
),
4248 global_node_page_state(NR_ACTIVE_FILE
),
4249 global_node_page_state(NR_INACTIVE_FILE
),
4250 global_node_page_state(NR_ISOLATED_FILE
),
4251 global_node_page_state(NR_UNEVICTABLE
),
4252 global_node_page_state(NR_FILE_DIRTY
),
4253 global_node_page_state(NR_WRITEBACK
),
4254 global_node_page_state(NR_UNSTABLE_NFS
),
4255 global_page_state(NR_SLAB_RECLAIMABLE
),
4256 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4257 global_node_page_state(NR_FILE_MAPPED
),
4258 global_node_page_state(NR_SHMEM
),
4259 global_page_state(NR_PAGETABLE
),
4260 global_page_state(NR_BOUNCE
),
4261 global_page_state(NR_FREE_PAGES
),
4263 global_page_state(NR_FREE_CMA_PAGES
));
4265 for_each_online_pgdat(pgdat
) {
4267 " active_anon:%lukB"
4268 " inactive_anon:%lukB"
4269 " active_file:%lukB"
4270 " inactive_file:%lukB"
4271 " unevictable:%lukB"
4272 " isolated(anon):%lukB"
4273 " isolated(file):%lukB"
4278 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4280 " shmem_pmdmapped: %lukB"
4283 " writeback_tmp:%lukB"
4285 " pages_scanned:%lu"
4286 " all_unreclaimable? %s"
4289 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4290 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4291 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4292 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4293 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4294 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4295 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4296 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4297 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4298 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4299 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4300 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4301 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4303 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4305 K(node_page_state(pgdat
, NR_SHMEM
)),
4306 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4307 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4308 node_page_state(pgdat
, NR_PAGES_SCANNED
),
4309 !pgdat_reclaimable(pgdat
) ? "yes" : "no");
4312 for_each_populated_zone(zone
) {
4315 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4319 for_each_online_cpu(cpu
)
4320 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4328 " active_anon:%lukB"
4329 " inactive_anon:%lukB"
4330 " active_file:%lukB"
4331 " inactive_file:%lukB"
4332 " unevictable:%lukB"
4333 " writepending:%lukB"
4337 " slab_reclaimable:%lukB"
4338 " slab_unreclaimable:%lukB"
4339 " kernel_stack:%lukB"
4347 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4348 K(min_wmark_pages(zone
)),
4349 K(low_wmark_pages(zone
)),
4350 K(high_wmark_pages(zone
)),
4351 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4352 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4353 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4354 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4355 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4356 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4357 K(zone
->present_pages
),
4358 K(zone
->managed_pages
),
4359 K(zone_page_state(zone
, NR_MLOCK
)),
4360 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
4361 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
4362 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4363 K(zone_page_state(zone
, NR_PAGETABLE
)),
4364 K(zone_page_state(zone
, NR_BOUNCE
)),
4366 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4367 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4368 printk("lowmem_reserve[]:");
4369 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4370 printk(" %ld", zone
->lowmem_reserve
[i
]);
4374 for_each_populated_zone(zone
) {
4376 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4377 unsigned char types
[MAX_ORDER
];
4379 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4382 printk("%s: ", zone
->name
);
4384 spin_lock_irqsave(&zone
->lock
, flags
);
4385 for (order
= 0; order
< MAX_ORDER
; order
++) {
4386 struct free_area
*area
= &zone
->free_area
[order
];
4389 nr
[order
] = area
->nr_free
;
4390 total
+= nr
[order
] << order
;
4393 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4394 if (!list_empty(&area
->free_list
[type
]))
4395 types
[order
] |= 1 << type
;
4398 spin_unlock_irqrestore(&zone
->lock
, flags
);
4399 for (order
= 0; order
< MAX_ORDER
; order
++) {
4400 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4402 show_migration_types(types
[order
]);
4404 printk("= %lukB\n", K(total
));
4407 hugetlb_show_meminfo();
4409 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4411 show_swap_cache_info();
4414 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4416 zoneref
->zone
= zone
;
4417 zoneref
->zone_idx
= zone_idx(zone
);
4421 * Builds allocation fallback zone lists.
4423 * Add all populated zones of a node to the zonelist.
4425 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4429 enum zone_type zone_type
= MAX_NR_ZONES
;
4433 zone
= pgdat
->node_zones
+ zone_type
;
4434 if (populated_zone(zone
)) {
4435 zoneref_set_zone(zone
,
4436 &zonelist
->_zonerefs
[nr_zones
++]);
4437 check_highest_zone(zone_type
);
4439 } while (zone_type
);
4447 * 0 = automatic detection of better ordering.
4448 * 1 = order by ([node] distance, -zonetype)
4449 * 2 = order by (-zonetype, [node] distance)
4451 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4452 * the same zonelist. So only NUMA can configure this param.
4454 #define ZONELIST_ORDER_DEFAULT 0
4455 #define ZONELIST_ORDER_NODE 1
4456 #define ZONELIST_ORDER_ZONE 2
4458 /* zonelist order in the kernel.
4459 * set_zonelist_order() will set this to NODE or ZONE.
4461 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4462 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4466 /* The value user specified ....changed by config */
4467 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4468 /* string for sysctl */
4469 #define NUMA_ZONELIST_ORDER_LEN 16
4470 char numa_zonelist_order
[16] = "default";
4473 * interface for configure zonelist ordering.
4474 * command line option "numa_zonelist_order"
4475 * = "[dD]efault - default, automatic configuration.
4476 * = "[nN]ode - order by node locality, then by zone within node
4477 * = "[zZ]one - order by zone, then by locality within zone
4480 static int __parse_numa_zonelist_order(char *s
)
4482 if (*s
== 'd' || *s
== 'D') {
4483 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4484 } else if (*s
== 'n' || *s
== 'N') {
4485 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4486 } else if (*s
== 'z' || *s
== 'Z') {
4487 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4489 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4495 static __init
int setup_numa_zonelist_order(char *s
)
4502 ret
= __parse_numa_zonelist_order(s
);
4504 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4508 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4511 * sysctl handler for numa_zonelist_order
4513 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4514 void __user
*buffer
, size_t *length
,
4517 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4519 static DEFINE_MUTEX(zl_order_mutex
);
4521 mutex_lock(&zl_order_mutex
);
4523 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4527 strcpy(saved_string
, (char *)table
->data
);
4529 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4533 int oldval
= user_zonelist_order
;
4535 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4538 * bogus value. restore saved string
4540 strncpy((char *)table
->data
, saved_string
,
4541 NUMA_ZONELIST_ORDER_LEN
);
4542 user_zonelist_order
= oldval
;
4543 } else if (oldval
!= user_zonelist_order
) {
4544 mutex_lock(&zonelists_mutex
);
4545 build_all_zonelists(NULL
, NULL
);
4546 mutex_unlock(&zonelists_mutex
);
4550 mutex_unlock(&zl_order_mutex
);
4555 #define MAX_NODE_LOAD (nr_online_nodes)
4556 static int node_load
[MAX_NUMNODES
];
4559 * find_next_best_node - find the next node that should appear in a given node's fallback list
4560 * @node: node whose fallback list we're appending
4561 * @used_node_mask: nodemask_t of already used nodes
4563 * We use a number of factors to determine which is the next node that should
4564 * appear on a given node's fallback list. The node should not have appeared
4565 * already in @node's fallback list, and it should be the next closest node
4566 * according to the distance array (which contains arbitrary distance values
4567 * from each node to each node in the system), and should also prefer nodes
4568 * with no CPUs, since presumably they'll have very little allocation pressure
4569 * on them otherwise.
4570 * It returns -1 if no node is found.
4572 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4575 int min_val
= INT_MAX
;
4576 int best_node
= NUMA_NO_NODE
;
4577 const struct cpumask
*tmp
= cpumask_of_node(0);
4579 /* Use the local node if we haven't already */
4580 if (!node_isset(node
, *used_node_mask
)) {
4581 node_set(node
, *used_node_mask
);
4585 for_each_node_state(n
, N_MEMORY
) {
4587 /* Don't want a node to appear more than once */
4588 if (node_isset(n
, *used_node_mask
))
4591 /* Use the distance array to find the distance */
4592 val
= node_distance(node
, n
);
4594 /* Penalize nodes under us ("prefer the next node") */
4597 /* Give preference to headless and unused nodes */
4598 tmp
= cpumask_of_node(n
);
4599 if (!cpumask_empty(tmp
))
4600 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4602 /* Slight preference for less loaded node */
4603 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4604 val
+= node_load
[n
];
4606 if (val
< min_val
) {
4613 node_set(best_node
, *used_node_mask
);
4620 * Build zonelists ordered by node and zones within node.
4621 * This results in maximum locality--normal zone overflows into local
4622 * DMA zone, if any--but risks exhausting DMA zone.
4624 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4627 struct zonelist
*zonelist
;
4629 zonelist
= &pgdat
->node_zonelists
[0];
4630 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4632 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4633 zonelist
->_zonerefs
[j
].zone
= NULL
;
4634 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4638 * Build gfp_thisnode zonelists
4640 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4643 struct zonelist
*zonelist
;
4645 zonelist
= &pgdat
->node_zonelists
[1];
4646 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4647 zonelist
->_zonerefs
[j
].zone
= NULL
;
4648 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4652 * Build zonelists ordered by zone and nodes within zones.
4653 * This results in conserving DMA zone[s] until all Normal memory is
4654 * exhausted, but results in overflowing to remote node while memory
4655 * may still exist in local DMA zone.
4657 static int node_order
[MAX_NUMNODES
];
4659 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4662 int zone_type
; /* needs to be signed */
4664 struct zonelist
*zonelist
;
4666 zonelist
= &pgdat
->node_zonelists
[0];
4668 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4669 for (j
= 0; j
< nr_nodes
; j
++) {
4670 node
= node_order
[j
];
4671 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4672 if (populated_zone(z
)) {
4674 &zonelist
->_zonerefs
[pos
++]);
4675 check_highest_zone(zone_type
);
4679 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4680 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4683 #if defined(CONFIG_64BIT)
4685 * Devices that require DMA32/DMA are relatively rare and do not justify a
4686 * penalty to every machine in case the specialised case applies. Default
4687 * to Node-ordering on 64-bit NUMA machines
4689 static int default_zonelist_order(void)
4691 return ZONELIST_ORDER_NODE
;
4695 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4696 * by the kernel. If processes running on node 0 deplete the low memory zone
4697 * then reclaim will occur more frequency increasing stalls and potentially
4698 * be easier to OOM if a large percentage of the zone is under writeback or
4699 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4700 * Hence, default to zone ordering on 32-bit.
4702 static int default_zonelist_order(void)
4704 return ZONELIST_ORDER_ZONE
;
4706 #endif /* CONFIG_64BIT */
4708 static void set_zonelist_order(void)
4710 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4711 current_zonelist_order
= default_zonelist_order();
4713 current_zonelist_order
= user_zonelist_order
;
4716 static void build_zonelists(pg_data_t
*pgdat
)
4719 nodemask_t used_mask
;
4720 int local_node
, prev_node
;
4721 struct zonelist
*zonelist
;
4722 unsigned int order
= current_zonelist_order
;
4724 /* initialize zonelists */
4725 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4726 zonelist
= pgdat
->node_zonelists
+ i
;
4727 zonelist
->_zonerefs
[0].zone
= NULL
;
4728 zonelist
->_zonerefs
[0].zone_idx
= 0;
4731 /* NUMA-aware ordering of nodes */
4732 local_node
= pgdat
->node_id
;
4733 load
= nr_online_nodes
;
4734 prev_node
= local_node
;
4735 nodes_clear(used_mask
);
4737 memset(node_order
, 0, sizeof(node_order
));
4740 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4742 * We don't want to pressure a particular node.
4743 * So adding penalty to the first node in same
4744 * distance group to make it round-robin.
4746 if (node_distance(local_node
, node
) !=
4747 node_distance(local_node
, prev_node
))
4748 node_load
[node
] = load
;
4752 if (order
== ZONELIST_ORDER_NODE
)
4753 build_zonelists_in_node_order(pgdat
, node
);
4755 node_order
[i
++] = node
; /* remember order */
4758 if (order
== ZONELIST_ORDER_ZONE
) {
4759 /* calculate node order -- i.e., DMA last! */
4760 build_zonelists_in_zone_order(pgdat
, i
);
4763 build_thisnode_zonelists(pgdat
);
4766 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4768 * Return node id of node used for "local" allocations.
4769 * I.e., first node id of first zone in arg node's generic zonelist.
4770 * Used for initializing percpu 'numa_mem', which is used primarily
4771 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4773 int local_memory_node(int node
)
4777 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4778 gfp_zone(GFP_KERNEL
),
4780 return z
->zone
->node
;
4784 #else /* CONFIG_NUMA */
4786 static void set_zonelist_order(void)
4788 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4791 static void build_zonelists(pg_data_t
*pgdat
)
4793 int node
, local_node
;
4795 struct zonelist
*zonelist
;
4797 local_node
= pgdat
->node_id
;
4799 zonelist
= &pgdat
->node_zonelists
[0];
4800 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4803 * Now we build the zonelist so that it contains the zones
4804 * of all the other nodes.
4805 * We don't want to pressure a particular node, so when
4806 * building the zones for node N, we make sure that the
4807 * zones coming right after the local ones are those from
4808 * node N+1 (modulo N)
4810 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4811 if (!node_online(node
))
4813 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4815 for (node
= 0; node
< local_node
; node
++) {
4816 if (!node_online(node
))
4818 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4821 zonelist
->_zonerefs
[j
].zone
= NULL
;
4822 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4825 #endif /* CONFIG_NUMA */
4828 * Boot pageset table. One per cpu which is going to be used for all
4829 * zones and all nodes. The parameters will be set in such a way
4830 * that an item put on a list will immediately be handed over to
4831 * the buddy list. This is safe since pageset manipulation is done
4832 * with interrupts disabled.
4834 * The boot_pagesets must be kept even after bootup is complete for
4835 * unused processors and/or zones. They do play a role for bootstrapping
4836 * hotplugged processors.
4838 * zoneinfo_show() and maybe other functions do
4839 * not check if the processor is online before following the pageset pointer.
4840 * Other parts of the kernel may not check if the zone is available.
4842 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4843 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4844 static void setup_zone_pageset(struct zone
*zone
);
4847 * Global mutex to protect against size modification of zonelists
4848 * as well as to serialize pageset setup for the new populated zone.
4850 DEFINE_MUTEX(zonelists_mutex
);
4852 /* return values int ....just for stop_machine() */
4853 static int __build_all_zonelists(void *data
)
4857 pg_data_t
*self
= data
;
4860 memset(node_load
, 0, sizeof(node_load
));
4863 if (self
&& !node_online(self
->node_id
)) {
4864 build_zonelists(self
);
4867 for_each_online_node(nid
) {
4868 pg_data_t
*pgdat
= NODE_DATA(nid
);
4870 build_zonelists(pgdat
);
4874 * Initialize the boot_pagesets that are going to be used
4875 * for bootstrapping processors. The real pagesets for
4876 * each zone will be allocated later when the per cpu
4877 * allocator is available.
4879 * boot_pagesets are used also for bootstrapping offline
4880 * cpus if the system is already booted because the pagesets
4881 * are needed to initialize allocators on a specific cpu too.
4882 * F.e. the percpu allocator needs the page allocator which
4883 * needs the percpu allocator in order to allocate its pagesets
4884 * (a chicken-egg dilemma).
4886 for_each_possible_cpu(cpu
) {
4887 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4889 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4891 * We now know the "local memory node" for each node--
4892 * i.e., the node of the first zone in the generic zonelist.
4893 * Set up numa_mem percpu variable for on-line cpus. During
4894 * boot, only the boot cpu should be on-line; we'll init the
4895 * secondary cpus' numa_mem as they come on-line. During
4896 * node/memory hotplug, we'll fixup all on-line cpus.
4898 if (cpu_online(cpu
))
4899 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4906 static noinline
void __init
4907 build_all_zonelists_init(void)
4909 __build_all_zonelists(NULL
);
4910 mminit_verify_zonelist();
4911 cpuset_init_current_mems_allowed();
4915 * Called with zonelists_mutex held always
4916 * unless system_state == SYSTEM_BOOTING.
4918 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4919 * [we're only called with non-NULL zone through __meminit paths] and
4920 * (2) call of __init annotated helper build_all_zonelists_init
4921 * [protected by SYSTEM_BOOTING].
4923 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4925 set_zonelist_order();
4927 if (system_state
== SYSTEM_BOOTING
) {
4928 build_all_zonelists_init();
4930 #ifdef CONFIG_MEMORY_HOTPLUG
4932 setup_zone_pageset(zone
);
4934 /* we have to stop all cpus to guarantee there is no user
4936 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4937 /* cpuset refresh routine should be here */
4939 vm_total_pages
= nr_free_pagecache_pages();
4941 * Disable grouping by mobility if the number of pages in the
4942 * system is too low to allow the mechanism to work. It would be
4943 * more accurate, but expensive to check per-zone. This check is
4944 * made on memory-hotadd so a system can start with mobility
4945 * disabled and enable it later
4947 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4948 page_group_by_mobility_disabled
= 1;
4950 page_group_by_mobility_disabled
= 0;
4952 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4954 zonelist_order_name
[current_zonelist_order
],
4955 page_group_by_mobility_disabled
? "off" : "on",
4958 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4963 * Helper functions to size the waitqueue hash table.
4964 * Essentially these want to choose hash table sizes sufficiently
4965 * large so that collisions trying to wait on pages are rare.
4966 * But in fact, the number of active page waitqueues on typical
4967 * systems is ridiculously low, less than 200. So this is even
4968 * conservative, even though it seems large.
4970 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4971 * waitqueues, i.e. the size of the waitq table given the number of pages.
4973 #define PAGES_PER_WAITQUEUE 256
4975 #ifndef CONFIG_MEMORY_HOTPLUG
4976 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4978 unsigned long size
= 1;
4980 pages
/= PAGES_PER_WAITQUEUE
;
4982 while (size
< pages
)
4986 * Once we have dozens or even hundreds of threads sleeping
4987 * on IO we've got bigger problems than wait queue collision.
4988 * Limit the size of the wait table to a reasonable size.
4990 size
= min(size
, 4096UL);
4992 return max(size
, 4UL);
4996 * A zone's size might be changed by hot-add, so it is not possible to determine
4997 * a suitable size for its wait_table. So we use the maximum size now.
4999 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
5001 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
5002 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
5003 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
5005 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
5006 * or more by the traditional way. (See above). It equals:
5008 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
5009 * ia64(16K page size) : = ( 8G + 4M)byte.
5010 * powerpc (64K page size) : = (32G +16M)byte.
5012 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
5019 * This is an integer logarithm so that shifts can be used later
5020 * to extract the more random high bits from the multiplicative
5021 * hash function before the remainder is taken.
5023 static inline unsigned long wait_table_bits(unsigned long size
)
5029 * Initially all pages are reserved - free ones are freed
5030 * up by free_all_bootmem() once the early boot process is
5031 * done. Non-atomic initialization, single-pass.
5033 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5034 unsigned long start_pfn
, enum memmap_context context
)
5036 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5037 unsigned long end_pfn
= start_pfn
+ size
;
5038 pg_data_t
*pgdat
= NODE_DATA(nid
);
5040 unsigned long nr_initialised
= 0;
5041 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5042 struct memblock_region
*r
= NULL
, *tmp
;
5045 if (highest_memmap_pfn
< end_pfn
- 1)
5046 highest_memmap_pfn
= end_pfn
- 1;
5049 * Honor reservation requested by the driver for this ZONE_DEVICE
5052 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5053 start_pfn
+= altmap
->reserve
;
5055 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5057 * There can be holes in boot-time mem_map[]s handed to this
5058 * function. They do not exist on hotplugged memory.
5060 if (context
!= MEMMAP_EARLY
)
5063 if (!early_pfn_valid(pfn
))
5065 if (!early_pfn_in_nid(pfn
, nid
))
5067 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5070 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5072 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
5073 * from zone_movable_pfn[nid] to end of each node should be
5074 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
5076 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
5077 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
5081 * Check given memblock attribute by firmware which can affect
5082 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5083 * mirrored, it's an overlapped memmap init. skip it.
5085 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5086 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5087 for_each_memblock(memory
, tmp
)
5088 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5092 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5093 memblock_is_mirror(r
)) {
5094 /* already initialized as NORMAL */
5095 pfn
= memblock_region_memory_end_pfn(r
);
5103 * Mark the block movable so that blocks are reserved for
5104 * movable at startup. This will force kernel allocations
5105 * to reserve their blocks rather than leaking throughout
5106 * the address space during boot when many long-lived
5107 * kernel allocations are made.
5109 * bitmap is created for zone's valid pfn range. but memmap
5110 * can be created for invalid pages (for alignment)
5111 * check here not to call set_pageblock_migratetype() against
5114 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5115 struct page
*page
= pfn_to_page(pfn
);
5117 __init_single_page(page
, pfn
, zone
, nid
);
5118 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5120 __init_single_pfn(pfn
, zone
, nid
);
5125 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5127 unsigned int order
, t
;
5128 for_each_migratetype_order(order
, t
) {
5129 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5130 zone
->free_area
[order
].nr_free
= 0;
5134 #ifndef __HAVE_ARCH_MEMMAP_INIT
5135 #define memmap_init(size, nid, zone, start_pfn) \
5136 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5139 static int zone_batchsize(struct zone
*zone
)
5145 * The per-cpu-pages pools are set to around 1000th of the
5146 * size of the zone. But no more than 1/2 of a meg.
5148 * OK, so we don't know how big the cache is. So guess.
5150 batch
= zone
->managed_pages
/ 1024;
5151 if (batch
* PAGE_SIZE
> 512 * 1024)
5152 batch
= (512 * 1024) / PAGE_SIZE
;
5153 batch
/= 4; /* We effectively *= 4 below */
5158 * Clamp the batch to a 2^n - 1 value. Having a power
5159 * of 2 value was found to be more likely to have
5160 * suboptimal cache aliasing properties in some cases.
5162 * For example if 2 tasks are alternately allocating
5163 * batches of pages, one task can end up with a lot
5164 * of pages of one half of the possible page colors
5165 * and the other with pages of the other colors.
5167 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5172 /* The deferral and batching of frees should be suppressed under NOMMU
5175 * The problem is that NOMMU needs to be able to allocate large chunks
5176 * of contiguous memory as there's no hardware page translation to
5177 * assemble apparent contiguous memory from discontiguous pages.
5179 * Queueing large contiguous runs of pages for batching, however,
5180 * causes the pages to actually be freed in smaller chunks. As there
5181 * can be a significant delay between the individual batches being
5182 * recycled, this leads to the once large chunks of space being
5183 * fragmented and becoming unavailable for high-order allocations.
5190 * pcp->high and pcp->batch values are related and dependent on one another:
5191 * ->batch must never be higher then ->high.
5192 * The following function updates them in a safe manner without read side
5195 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5196 * those fields changing asynchronously (acording the the above rule).
5198 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5199 * outside of boot time (or some other assurance that no concurrent updaters
5202 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5203 unsigned long batch
)
5205 /* start with a fail safe value for batch */
5209 /* Update high, then batch, in order */
5216 /* a companion to pageset_set_high() */
5217 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5219 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5222 static void pageset_init(struct per_cpu_pageset
*p
)
5224 struct per_cpu_pages
*pcp
;
5227 memset(p
, 0, sizeof(*p
));
5231 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5232 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5235 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5238 pageset_set_batch(p
, batch
);
5242 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5243 * to the value high for the pageset p.
5245 static void pageset_set_high(struct per_cpu_pageset
*p
,
5248 unsigned long batch
= max(1UL, high
/ 4);
5249 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5250 batch
= PAGE_SHIFT
* 8;
5252 pageset_update(&p
->pcp
, high
, batch
);
5255 static void pageset_set_high_and_batch(struct zone
*zone
,
5256 struct per_cpu_pageset
*pcp
)
5258 if (percpu_pagelist_fraction
)
5259 pageset_set_high(pcp
,
5260 (zone
->managed_pages
/
5261 percpu_pagelist_fraction
));
5263 pageset_set_batch(pcp
, zone_batchsize(zone
));
5266 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5268 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5271 pageset_set_high_and_batch(zone
, pcp
);
5274 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5277 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5278 for_each_possible_cpu(cpu
)
5279 zone_pageset_init(zone
, cpu
);
5281 if (!zone
->zone_pgdat
->per_cpu_nodestats
) {
5282 zone
->zone_pgdat
->per_cpu_nodestats
=
5283 alloc_percpu(struct per_cpu_nodestat
);
5288 * Allocate per cpu pagesets and initialize them.
5289 * Before this call only boot pagesets were available.
5291 void __init
setup_per_cpu_pageset(void)
5295 for_each_populated_zone(zone
)
5296 setup_zone_pageset(zone
);
5299 static noinline __init_refok
5300 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
5306 * The per-page waitqueue mechanism uses hashed waitqueues
5309 zone
->wait_table_hash_nr_entries
=
5310 wait_table_hash_nr_entries(zone_size_pages
);
5311 zone
->wait_table_bits
=
5312 wait_table_bits(zone
->wait_table_hash_nr_entries
);
5313 alloc_size
= zone
->wait_table_hash_nr_entries
5314 * sizeof(wait_queue_head_t
);
5316 if (!slab_is_available()) {
5317 zone
->wait_table
= (wait_queue_head_t
*)
5318 memblock_virt_alloc_node_nopanic(
5319 alloc_size
, zone
->zone_pgdat
->node_id
);
5322 * This case means that a zone whose size was 0 gets new memory
5323 * via memory hot-add.
5324 * But it may be the case that a new node was hot-added. In
5325 * this case vmalloc() will not be able to use this new node's
5326 * memory - this wait_table must be initialized to use this new
5327 * node itself as well.
5328 * To use this new node's memory, further consideration will be
5331 zone
->wait_table
= vmalloc(alloc_size
);
5333 if (!zone
->wait_table
)
5336 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
5337 init_waitqueue_head(zone
->wait_table
+ i
);
5342 static __meminit
void zone_pcp_init(struct zone
*zone
)
5345 * per cpu subsystem is not up at this point. The following code
5346 * relies on the ability of the linker to provide the
5347 * offset of a (static) per cpu variable into the per cpu area.
5349 zone
->pageset
= &boot_pageset
;
5351 if (populated_zone(zone
))
5352 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5353 zone
->name
, zone
->present_pages
,
5354 zone_batchsize(zone
));
5357 int __meminit
init_currently_empty_zone(struct zone
*zone
,
5358 unsigned long zone_start_pfn
,
5361 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5363 ret
= zone_wait_table_init(zone
, size
);
5366 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5368 zone
->zone_start_pfn
= zone_start_pfn
;
5370 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5371 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5373 (unsigned long)zone_idx(zone
),
5374 zone_start_pfn
, (zone_start_pfn
+ size
));
5376 zone_init_free_lists(zone
);
5381 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5382 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5385 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5387 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5388 struct mminit_pfnnid_cache
*state
)
5390 unsigned long start_pfn
, end_pfn
;
5393 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5394 return state
->last_nid
;
5396 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5398 state
->last_start
= start_pfn
;
5399 state
->last_end
= end_pfn
;
5400 state
->last_nid
= nid
;
5405 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5408 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5409 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5410 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5412 * If an architecture guarantees that all ranges registered contain no holes
5413 * and may be freed, this this function may be used instead of calling
5414 * memblock_free_early_nid() manually.
5416 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5418 unsigned long start_pfn
, end_pfn
;
5421 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5422 start_pfn
= min(start_pfn
, max_low_pfn
);
5423 end_pfn
= min(end_pfn
, max_low_pfn
);
5425 if (start_pfn
< end_pfn
)
5426 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5427 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5433 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5434 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5436 * If an architecture guarantees that all ranges registered contain no holes and may
5437 * be freed, this function may be used instead of calling memory_present() manually.
5439 void __init
sparse_memory_present_with_active_regions(int nid
)
5441 unsigned long start_pfn
, end_pfn
;
5444 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5445 memory_present(this_nid
, start_pfn
, end_pfn
);
5449 * get_pfn_range_for_nid - Return the start and end page frames for a node
5450 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5451 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5452 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5454 * It returns the start and end page frame of a node based on information
5455 * provided by memblock_set_node(). If called for a node
5456 * with no available memory, a warning is printed and the start and end
5459 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5460 unsigned long *start_pfn
, unsigned long *end_pfn
)
5462 unsigned long this_start_pfn
, this_end_pfn
;
5468 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5469 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5470 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5473 if (*start_pfn
== -1UL)
5478 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5479 * assumption is made that zones within a node are ordered in monotonic
5480 * increasing memory addresses so that the "highest" populated zone is used
5482 static void __init
find_usable_zone_for_movable(void)
5485 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5486 if (zone_index
== ZONE_MOVABLE
)
5489 if (arch_zone_highest_possible_pfn
[zone_index
] >
5490 arch_zone_lowest_possible_pfn
[zone_index
])
5494 VM_BUG_ON(zone_index
== -1);
5495 movable_zone
= zone_index
;
5499 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5500 * because it is sized independent of architecture. Unlike the other zones,
5501 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5502 * in each node depending on the size of each node and how evenly kernelcore
5503 * is distributed. This helper function adjusts the zone ranges
5504 * provided by the architecture for a given node by using the end of the
5505 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5506 * zones within a node are in order of monotonic increases memory addresses
5508 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5509 unsigned long zone_type
,
5510 unsigned long node_start_pfn
,
5511 unsigned long node_end_pfn
,
5512 unsigned long *zone_start_pfn
,
5513 unsigned long *zone_end_pfn
)
5515 /* Only adjust if ZONE_MOVABLE is on this node */
5516 if (zone_movable_pfn
[nid
]) {
5517 /* Size ZONE_MOVABLE */
5518 if (zone_type
== ZONE_MOVABLE
) {
5519 *zone_start_pfn
= zone_movable_pfn
[nid
];
5520 *zone_end_pfn
= min(node_end_pfn
,
5521 arch_zone_highest_possible_pfn
[movable_zone
]);
5523 /* Check if this whole range is within ZONE_MOVABLE */
5524 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5525 *zone_start_pfn
= *zone_end_pfn
;
5530 * Return the number of pages a zone spans in a node, including holes
5531 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5533 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5534 unsigned long zone_type
,
5535 unsigned long node_start_pfn
,
5536 unsigned long node_end_pfn
,
5537 unsigned long *zone_start_pfn
,
5538 unsigned long *zone_end_pfn
,
5539 unsigned long *ignored
)
5541 /* When hotadd a new node from cpu_up(), the node should be empty */
5542 if (!node_start_pfn
&& !node_end_pfn
)
5545 /* Get the start and end of the zone */
5546 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5547 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5548 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5549 node_start_pfn
, node_end_pfn
,
5550 zone_start_pfn
, zone_end_pfn
);
5552 /* Check that this node has pages within the zone's required range */
5553 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5556 /* Move the zone boundaries inside the node if necessary */
5557 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5558 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5560 /* Return the spanned pages */
5561 return *zone_end_pfn
- *zone_start_pfn
;
5565 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5566 * then all holes in the requested range will be accounted for.
5568 unsigned long __meminit
__absent_pages_in_range(int nid
,
5569 unsigned long range_start_pfn
,
5570 unsigned long range_end_pfn
)
5572 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5573 unsigned long start_pfn
, end_pfn
;
5576 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5577 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5578 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5579 nr_absent
-= end_pfn
- start_pfn
;
5585 * absent_pages_in_range - Return number of page frames in holes within a range
5586 * @start_pfn: The start PFN to start searching for holes
5587 * @end_pfn: The end PFN to stop searching for holes
5589 * It returns the number of pages frames in memory holes within a range.
5591 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5592 unsigned long end_pfn
)
5594 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5597 /* Return the number of page frames in holes in a zone on a node */
5598 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5599 unsigned long zone_type
,
5600 unsigned long node_start_pfn
,
5601 unsigned long node_end_pfn
,
5602 unsigned long *ignored
)
5604 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5605 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5606 unsigned long zone_start_pfn
, zone_end_pfn
;
5607 unsigned long nr_absent
;
5609 /* When hotadd a new node from cpu_up(), the node should be empty */
5610 if (!node_start_pfn
&& !node_end_pfn
)
5613 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5614 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5616 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5617 node_start_pfn
, node_end_pfn
,
5618 &zone_start_pfn
, &zone_end_pfn
);
5619 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5622 * ZONE_MOVABLE handling.
5623 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5626 if (zone_movable_pfn
[nid
]) {
5627 if (mirrored_kernelcore
) {
5628 unsigned long start_pfn
, end_pfn
;
5629 struct memblock_region
*r
;
5631 for_each_memblock(memory
, r
) {
5632 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5633 zone_start_pfn
, zone_end_pfn
);
5634 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5635 zone_start_pfn
, zone_end_pfn
);
5637 if (zone_type
== ZONE_MOVABLE
&&
5638 memblock_is_mirror(r
))
5639 nr_absent
+= end_pfn
- start_pfn
;
5641 if (zone_type
== ZONE_NORMAL
&&
5642 !memblock_is_mirror(r
))
5643 nr_absent
+= end_pfn
- start_pfn
;
5646 if (zone_type
== ZONE_NORMAL
)
5647 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5654 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5655 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5656 unsigned long zone_type
,
5657 unsigned long node_start_pfn
,
5658 unsigned long node_end_pfn
,
5659 unsigned long *zone_start_pfn
,
5660 unsigned long *zone_end_pfn
,
5661 unsigned long *zones_size
)
5665 *zone_start_pfn
= node_start_pfn
;
5666 for (zone
= 0; zone
< zone_type
; zone
++)
5667 *zone_start_pfn
+= zones_size
[zone
];
5669 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5671 return zones_size
[zone_type
];
5674 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5675 unsigned long zone_type
,
5676 unsigned long node_start_pfn
,
5677 unsigned long node_end_pfn
,
5678 unsigned long *zholes_size
)
5683 return zholes_size
[zone_type
];
5686 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5688 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5689 unsigned long node_start_pfn
,
5690 unsigned long node_end_pfn
,
5691 unsigned long *zones_size
,
5692 unsigned long *zholes_size
)
5694 unsigned long realtotalpages
= 0, totalpages
= 0;
5697 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5698 struct zone
*zone
= pgdat
->node_zones
+ i
;
5699 unsigned long zone_start_pfn
, zone_end_pfn
;
5700 unsigned long size
, real_size
;
5702 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5708 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5709 node_start_pfn
, node_end_pfn
,
5712 zone
->zone_start_pfn
= zone_start_pfn
;
5714 zone
->zone_start_pfn
= 0;
5715 zone
->spanned_pages
= size
;
5716 zone
->present_pages
= real_size
;
5719 realtotalpages
+= real_size
;
5722 pgdat
->node_spanned_pages
= totalpages
;
5723 pgdat
->node_present_pages
= realtotalpages
;
5724 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5728 #ifndef CONFIG_SPARSEMEM
5730 * Calculate the size of the zone->blockflags rounded to an unsigned long
5731 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5732 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5733 * round what is now in bits to nearest long in bits, then return it in
5736 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5738 unsigned long usemapsize
;
5740 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5741 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5742 usemapsize
= usemapsize
>> pageblock_order
;
5743 usemapsize
*= NR_PAGEBLOCK_BITS
;
5744 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5746 return usemapsize
/ 8;
5749 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5751 unsigned long zone_start_pfn
,
5752 unsigned long zonesize
)
5754 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5755 zone
->pageblock_flags
= NULL
;
5757 zone
->pageblock_flags
=
5758 memblock_virt_alloc_node_nopanic(usemapsize
,
5762 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5763 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5764 #endif /* CONFIG_SPARSEMEM */
5766 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5768 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5769 void __paginginit
set_pageblock_order(void)
5773 /* Check that pageblock_nr_pages has not already been setup */
5774 if (pageblock_order
)
5777 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5778 order
= HUGETLB_PAGE_ORDER
;
5780 order
= MAX_ORDER
- 1;
5783 * Assume the largest contiguous order of interest is a huge page.
5784 * This value may be variable depending on boot parameters on IA64 and
5787 pageblock_order
= order
;
5789 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5792 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5793 * is unused as pageblock_order is set at compile-time. See
5794 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5797 void __paginginit
set_pageblock_order(void)
5801 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5803 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5804 unsigned long present_pages
)
5806 unsigned long pages
= spanned_pages
;
5809 * Provide a more accurate estimation if there are holes within
5810 * the zone and SPARSEMEM is in use. If there are holes within the
5811 * zone, each populated memory region may cost us one or two extra
5812 * memmap pages due to alignment because memmap pages for each
5813 * populated regions may not naturally algined on page boundary.
5814 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5816 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5817 IS_ENABLED(CONFIG_SPARSEMEM
))
5818 pages
= present_pages
;
5820 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5824 * Set up the zone data structures:
5825 * - mark all pages reserved
5826 * - mark all memory queues empty
5827 * - clear the memory bitmaps
5829 * NOTE: pgdat should get zeroed by caller.
5831 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5834 int nid
= pgdat
->node_id
;
5837 pgdat_resize_init(pgdat
);
5838 #ifdef CONFIG_NUMA_BALANCING
5839 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5840 pgdat
->numabalancing_migrate_nr_pages
= 0;
5841 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5843 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5844 spin_lock_init(&pgdat
->split_queue_lock
);
5845 INIT_LIST_HEAD(&pgdat
->split_queue
);
5846 pgdat
->split_queue_len
= 0;
5848 init_waitqueue_head(&pgdat
->kswapd_wait
);
5849 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5850 #ifdef CONFIG_COMPACTION
5851 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5853 pgdat_page_ext_init(pgdat
);
5854 spin_lock_init(&pgdat
->lru_lock
);
5855 lruvec_init(node_lruvec(pgdat
));
5857 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5858 struct zone
*zone
= pgdat
->node_zones
+ j
;
5859 unsigned long size
, realsize
, freesize
, memmap_pages
;
5860 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5862 size
= zone
->spanned_pages
;
5863 realsize
= freesize
= zone
->present_pages
;
5866 * Adjust freesize so that it accounts for how much memory
5867 * is used by this zone for memmap. This affects the watermark
5868 * and per-cpu initialisations
5870 memmap_pages
= calc_memmap_size(size
, realsize
);
5871 if (!is_highmem_idx(j
)) {
5872 if (freesize
>= memmap_pages
) {
5873 freesize
-= memmap_pages
;
5876 " %s zone: %lu pages used for memmap\n",
5877 zone_names
[j
], memmap_pages
);
5879 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5880 zone_names
[j
], memmap_pages
, freesize
);
5883 /* Account for reserved pages */
5884 if (j
== 0 && freesize
> dma_reserve
) {
5885 freesize
-= dma_reserve
;
5886 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5887 zone_names
[0], dma_reserve
);
5890 if (!is_highmem_idx(j
))
5891 nr_kernel_pages
+= freesize
;
5892 /* Charge for highmem memmap if there are enough kernel pages */
5893 else if (nr_kernel_pages
> memmap_pages
* 2)
5894 nr_kernel_pages
-= memmap_pages
;
5895 nr_all_pages
+= freesize
;
5898 * Set an approximate value for lowmem here, it will be adjusted
5899 * when the bootmem allocator frees pages into the buddy system.
5900 * And all highmem pages will be managed by the buddy system.
5902 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5905 pgdat
->min_unmapped_pages
+= (freesize
*sysctl_min_unmapped_ratio
)
5907 pgdat
->min_slab_pages
+= (freesize
* sysctl_min_slab_ratio
) / 100;
5909 zone
->name
= zone_names
[j
];
5910 zone
->zone_pgdat
= pgdat
;
5911 spin_lock_init(&zone
->lock
);
5912 zone_seqlock_init(zone
);
5913 zone_pcp_init(zone
);
5918 set_pageblock_order();
5919 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5920 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5922 memmap_init(size
, nid
, j
, zone_start_pfn
);
5926 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5928 unsigned long __maybe_unused start
= 0;
5929 unsigned long __maybe_unused offset
= 0;
5931 /* Skip empty nodes */
5932 if (!pgdat
->node_spanned_pages
)
5935 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5936 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5937 offset
= pgdat
->node_start_pfn
- start
;
5938 /* ia64 gets its own node_mem_map, before this, without bootmem */
5939 if (!pgdat
->node_mem_map
) {
5940 unsigned long size
, end
;
5944 * The zone's endpoints aren't required to be MAX_ORDER
5945 * aligned but the node_mem_map endpoints must be in order
5946 * for the buddy allocator to function correctly.
5948 end
= pgdat_end_pfn(pgdat
);
5949 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5950 size
= (end
- start
) * sizeof(struct page
);
5951 map
= alloc_remap(pgdat
->node_id
, size
);
5953 map
= memblock_virt_alloc_node_nopanic(size
,
5955 pgdat
->node_mem_map
= map
+ offset
;
5957 #ifndef CONFIG_NEED_MULTIPLE_NODES
5959 * With no DISCONTIG, the global mem_map is just set as node 0's
5961 if (pgdat
== NODE_DATA(0)) {
5962 mem_map
= NODE_DATA(0)->node_mem_map
;
5963 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5964 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5966 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5969 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5972 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5973 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5975 pg_data_t
*pgdat
= NODE_DATA(nid
);
5976 unsigned long start_pfn
= 0;
5977 unsigned long end_pfn
= 0;
5979 /* pg_data_t should be reset to zero when it's allocated */
5980 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
5982 reset_deferred_meminit(pgdat
);
5983 pgdat
->node_id
= nid
;
5984 pgdat
->node_start_pfn
= node_start_pfn
;
5985 pgdat
->per_cpu_nodestats
= NULL
;
5986 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5987 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5988 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5989 (u64
)start_pfn
<< PAGE_SHIFT
,
5990 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5992 start_pfn
= node_start_pfn
;
5994 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5995 zones_size
, zholes_size
);
5997 alloc_node_mem_map(pgdat
);
5998 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5999 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6000 nid
, (unsigned long)pgdat
,
6001 (unsigned long)pgdat
->node_mem_map
);
6004 free_area_init_core(pgdat
);
6007 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6009 #if MAX_NUMNODES > 1
6011 * Figure out the number of possible node ids.
6013 void __init
setup_nr_node_ids(void)
6015 unsigned int highest
;
6017 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6018 nr_node_ids
= highest
+ 1;
6023 * node_map_pfn_alignment - determine the maximum internode alignment
6025 * This function should be called after node map is populated and sorted.
6026 * It calculates the maximum power of two alignment which can distinguish
6029 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6030 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6031 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6032 * shifted, 1GiB is enough and this function will indicate so.
6034 * This is used to test whether pfn -> nid mapping of the chosen memory
6035 * model has fine enough granularity to avoid incorrect mapping for the
6036 * populated node map.
6038 * Returns the determined alignment in pfn's. 0 if there is no alignment
6039 * requirement (single node).
6041 unsigned long __init
node_map_pfn_alignment(void)
6043 unsigned long accl_mask
= 0, last_end
= 0;
6044 unsigned long start
, end
, mask
;
6048 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6049 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6056 * Start with a mask granular enough to pin-point to the
6057 * start pfn and tick off bits one-by-one until it becomes
6058 * too coarse to separate the current node from the last.
6060 mask
= ~((1 << __ffs(start
)) - 1);
6061 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6064 /* accumulate all internode masks */
6068 /* convert mask to number of pages */
6069 return ~accl_mask
+ 1;
6072 /* Find the lowest pfn for a node */
6073 static unsigned long __init
find_min_pfn_for_node(int nid
)
6075 unsigned long min_pfn
= ULONG_MAX
;
6076 unsigned long start_pfn
;
6079 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6080 min_pfn
= min(min_pfn
, start_pfn
);
6082 if (min_pfn
== ULONG_MAX
) {
6083 pr_warn("Could not find start_pfn for node %d\n", nid
);
6091 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6093 * It returns the minimum PFN based on information provided via
6094 * memblock_set_node().
6096 unsigned long __init
find_min_pfn_with_active_regions(void)
6098 return find_min_pfn_for_node(MAX_NUMNODES
);
6102 * early_calculate_totalpages()
6103 * Sum pages in active regions for movable zone.
6104 * Populate N_MEMORY for calculating usable_nodes.
6106 static unsigned long __init
early_calculate_totalpages(void)
6108 unsigned long totalpages
= 0;
6109 unsigned long start_pfn
, end_pfn
;
6112 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6113 unsigned long pages
= end_pfn
- start_pfn
;
6115 totalpages
+= pages
;
6117 node_set_state(nid
, N_MEMORY
);
6123 * Find the PFN the Movable zone begins in each node. Kernel memory
6124 * is spread evenly between nodes as long as the nodes have enough
6125 * memory. When they don't, some nodes will have more kernelcore than
6128 static void __init
find_zone_movable_pfns_for_nodes(void)
6131 unsigned long usable_startpfn
;
6132 unsigned long kernelcore_node
, kernelcore_remaining
;
6133 /* save the state before borrow the nodemask */
6134 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6135 unsigned long totalpages
= early_calculate_totalpages();
6136 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6137 struct memblock_region
*r
;
6139 /* Need to find movable_zone earlier when movable_node is specified. */
6140 find_usable_zone_for_movable();
6143 * If movable_node is specified, ignore kernelcore and movablecore
6146 if (movable_node_is_enabled()) {
6147 for_each_memblock(memory
, r
) {
6148 if (!memblock_is_hotpluggable(r
))
6153 usable_startpfn
= PFN_DOWN(r
->base
);
6154 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6155 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6163 * If kernelcore=mirror is specified, ignore movablecore option
6165 if (mirrored_kernelcore
) {
6166 bool mem_below_4gb_not_mirrored
= false;
6168 for_each_memblock(memory
, r
) {
6169 if (memblock_is_mirror(r
))
6174 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6176 if (usable_startpfn
< 0x100000) {
6177 mem_below_4gb_not_mirrored
= true;
6181 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6182 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6186 if (mem_below_4gb_not_mirrored
)
6187 pr_warn("This configuration results in unmirrored kernel memory.");
6193 * If movablecore=nn[KMG] was specified, calculate what size of
6194 * kernelcore that corresponds so that memory usable for
6195 * any allocation type is evenly spread. If both kernelcore
6196 * and movablecore are specified, then the value of kernelcore
6197 * will be used for required_kernelcore if it's greater than
6198 * what movablecore would have allowed.
6200 if (required_movablecore
) {
6201 unsigned long corepages
;
6204 * Round-up so that ZONE_MOVABLE is at least as large as what
6205 * was requested by the user
6207 required_movablecore
=
6208 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6209 required_movablecore
= min(totalpages
, required_movablecore
);
6210 corepages
= totalpages
- required_movablecore
;
6212 required_kernelcore
= max(required_kernelcore
, corepages
);
6216 * If kernelcore was not specified or kernelcore size is larger
6217 * than totalpages, there is no ZONE_MOVABLE.
6219 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6222 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6223 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6226 /* Spread kernelcore memory as evenly as possible throughout nodes */
6227 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6228 for_each_node_state(nid
, N_MEMORY
) {
6229 unsigned long start_pfn
, end_pfn
;
6232 * Recalculate kernelcore_node if the division per node
6233 * now exceeds what is necessary to satisfy the requested
6234 * amount of memory for the kernel
6236 if (required_kernelcore
< kernelcore_node
)
6237 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6240 * As the map is walked, we track how much memory is usable
6241 * by the kernel using kernelcore_remaining. When it is
6242 * 0, the rest of the node is usable by ZONE_MOVABLE
6244 kernelcore_remaining
= kernelcore_node
;
6246 /* Go through each range of PFNs within this node */
6247 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6248 unsigned long size_pages
;
6250 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6251 if (start_pfn
>= end_pfn
)
6254 /* Account for what is only usable for kernelcore */
6255 if (start_pfn
< usable_startpfn
) {
6256 unsigned long kernel_pages
;
6257 kernel_pages
= min(end_pfn
, usable_startpfn
)
6260 kernelcore_remaining
-= min(kernel_pages
,
6261 kernelcore_remaining
);
6262 required_kernelcore
-= min(kernel_pages
,
6263 required_kernelcore
);
6265 /* Continue if range is now fully accounted */
6266 if (end_pfn
<= usable_startpfn
) {
6269 * Push zone_movable_pfn to the end so
6270 * that if we have to rebalance
6271 * kernelcore across nodes, we will
6272 * not double account here
6274 zone_movable_pfn
[nid
] = end_pfn
;
6277 start_pfn
= usable_startpfn
;
6281 * The usable PFN range for ZONE_MOVABLE is from
6282 * start_pfn->end_pfn. Calculate size_pages as the
6283 * number of pages used as kernelcore
6285 size_pages
= end_pfn
- start_pfn
;
6286 if (size_pages
> kernelcore_remaining
)
6287 size_pages
= kernelcore_remaining
;
6288 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6291 * Some kernelcore has been met, update counts and
6292 * break if the kernelcore for this node has been
6295 required_kernelcore
-= min(required_kernelcore
,
6297 kernelcore_remaining
-= size_pages
;
6298 if (!kernelcore_remaining
)
6304 * If there is still required_kernelcore, we do another pass with one
6305 * less node in the count. This will push zone_movable_pfn[nid] further
6306 * along on the nodes that still have memory until kernelcore is
6310 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6314 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6315 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6316 zone_movable_pfn
[nid
] =
6317 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6320 /* restore the node_state */
6321 node_states
[N_MEMORY
] = saved_node_state
;
6324 /* Any regular or high memory on that node ? */
6325 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6327 enum zone_type zone_type
;
6329 if (N_MEMORY
== N_NORMAL_MEMORY
)
6332 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6333 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6334 if (populated_zone(zone
)) {
6335 node_set_state(nid
, N_HIGH_MEMORY
);
6336 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6337 zone_type
<= ZONE_NORMAL
)
6338 node_set_state(nid
, N_NORMAL_MEMORY
);
6345 * free_area_init_nodes - Initialise all pg_data_t and zone data
6346 * @max_zone_pfn: an array of max PFNs for each zone
6348 * This will call free_area_init_node() for each active node in the system.
6349 * Using the page ranges provided by memblock_set_node(), the size of each
6350 * zone in each node and their holes is calculated. If the maximum PFN
6351 * between two adjacent zones match, it is assumed that the zone is empty.
6352 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6353 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6354 * starts where the previous one ended. For example, ZONE_DMA32 starts
6355 * at arch_max_dma_pfn.
6357 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6359 unsigned long start_pfn
, end_pfn
;
6362 /* Record where the zone boundaries are */
6363 memset(arch_zone_lowest_possible_pfn
, 0,
6364 sizeof(arch_zone_lowest_possible_pfn
));
6365 memset(arch_zone_highest_possible_pfn
, 0,
6366 sizeof(arch_zone_highest_possible_pfn
));
6368 start_pfn
= find_min_pfn_with_active_regions();
6370 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6371 if (i
== ZONE_MOVABLE
)
6374 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6375 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6376 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6378 start_pfn
= end_pfn
;
6380 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
6381 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
6383 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6384 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6385 find_zone_movable_pfns_for_nodes();
6387 /* Print out the zone ranges */
6388 pr_info("Zone ranges:\n");
6389 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6390 if (i
== ZONE_MOVABLE
)
6392 pr_info(" %-8s ", zone_names
[i
]);
6393 if (arch_zone_lowest_possible_pfn
[i
] ==
6394 arch_zone_highest_possible_pfn
[i
])
6397 pr_cont("[mem %#018Lx-%#018Lx]\n",
6398 (u64
)arch_zone_lowest_possible_pfn
[i
]
6400 ((u64
)arch_zone_highest_possible_pfn
[i
]
6401 << PAGE_SHIFT
) - 1);
6404 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6405 pr_info("Movable zone start for each node\n");
6406 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6407 if (zone_movable_pfn
[i
])
6408 pr_info(" Node %d: %#018Lx\n", i
,
6409 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6412 /* Print out the early node map */
6413 pr_info("Early memory node ranges\n");
6414 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6415 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6416 (u64
)start_pfn
<< PAGE_SHIFT
,
6417 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6419 /* Initialise every node */
6420 mminit_verify_pageflags_layout();
6421 setup_nr_node_ids();
6422 for_each_online_node(nid
) {
6423 pg_data_t
*pgdat
= NODE_DATA(nid
);
6424 free_area_init_node(nid
, NULL
,
6425 find_min_pfn_for_node(nid
), NULL
);
6427 /* Any memory on that node */
6428 if (pgdat
->node_present_pages
)
6429 node_set_state(nid
, N_MEMORY
);
6430 check_for_memory(pgdat
, nid
);
6434 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6436 unsigned long long coremem
;
6440 coremem
= memparse(p
, &p
);
6441 *core
= coremem
>> PAGE_SHIFT
;
6443 /* Paranoid check that UL is enough for the coremem value */
6444 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6450 * kernelcore=size sets the amount of memory for use for allocations that
6451 * cannot be reclaimed or migrated.
6453 static int __init
cmdline_parse_kernelcore(char *p
)
6455 /* parse kernelcore=mirror */
6456 if (parse_option_str(p
, "mirror")) {
6457 mirrored_kernelcore
= true;
6461 return cmdline_parse_core(p
, &required_kernelcore
);
6465 * movablecore=size sets the amount of memory for use for allocations that
6466 * can be reclaimed or migrated.
6468 static int __init
cmdline_parse_movablecore(char *p
)
6470 return cmdline_parse_core(p
, &required_movablecore
);
6473 early_param("kernelcore", cmdline_parse_kernelcore
);
6474 early_param("movablecore", cmdline_parse_movablecore
);
6476 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6478 void adjust_managed_page_count(struct page
*page
, long count
)
6480 spin_lock(&managed_page_count_lock
);
6481 page_zone(page
)->managed_pages
+= count
;
6482 totalram_pages
+= count
;
6483 #ifdef CONFIG_HIGHMEM
6484 if (PageHighMem(page
))
6485 totalhigh_pages
+= count
;
6487 spin_unlock(&managed_page_count_lock
);
6489 EXPORT_SYMBOL(adjust_managed_page_count
);
6491 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6494 unsigned long pages
= 0;
6496 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6497 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6498 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6499 if ((unsigned int)poison
<= 0xFF)
6500 memset(pos
, poison
, PAGE_SIZE
);
6501 free_reserved_page(virt_to_page(pos
));
6505 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6506 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6510 EXPORT_SYMBOL(free_reserved_area
);
6512 #ifdef CONFIG_HIGHMEM
6513 void free_highmem_page(struct page
*page
)
6515 __free_reserved_page(page
);
6517 page_zone(page
)->managed_pages
++;
6523 void __init
mem_init_print_info(const char *str
)
6525 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6526 unsigned long init_code_size
, init_data_size
;
6528 physpages
= get_num_physpages();
6529 codesize
= _etext
- _stext
;
6530 datasize
= _edata
- _sdata
;
6531 rosize
= __end_rodata
- __start_rodata
;
6532 bss_size
= __bss_stop
- __bss_start
;
6533 init_data_size
= __init_end
- __init_begin
;
6534 init_code_size
= _einittext
- _sinittext
;
6537 * Detect special cases and adjust section sizes accordingly:
6538 * 1) .init.* may be embedded into .data sections
6539 * 2) .init.text.* may be out of [__init_begin, __init_end],
6540 * please refer to arch/tile/kernel/vmlinux.lds.S.
6541 * 3) .rodata.* may be embedded into .text or .data sections.
6543 #define adj_init_size(start, end, size, pos, adj) \
6545 if (start <= pos && pos < end && size > adj) \
6549 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6550 _sinittext
, init_code_size
);
6551 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6552 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6553 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6554 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6556 #undef adj_init_size
6558 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6559 #ifdef CONFIG_HIGHMEM
6563 nr_free_pages() << (PAGE_SHIFT
- 10),
6564 physpages
<< (PAGE_SHIFT
- 10),
6565 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6566 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6567 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6568 totalcma_pages
<< (PAGE_SHIFT
- 10),
6569 #ifdef CONFIG_HIGHMEM
6570 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6572 str
? ", " : "", str
? str
: "");
6576 * set_dma_reserve - set the specified number of pages reserved in the first zone
6577 * @new_dma_reserve: The number of pages to mark reserved
6579 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6580 * In the DMA zone, a significant percentage may be consumed by kernel image
6581 * and other unfreeable allocations which can skew the watermarks badly. This
6582 * function may optionally be used to account for unfreeable pages in the
6583 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6584 * smaller per-cpu batchsize.
6586 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6588 dma_reserve
= new_dma_reserve
;
6591 void __init
free_area_init(unsigned long *zones_size
)
6593 free_area_init_node(0, zones_size
,
6594 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6597 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6598 unsigned long action
, void *hcpu
)
6600 int cpu
= (unsigned long)hcpu
;
6602 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6603 lru_add_drain_cpu(cpu
);
6607 * Spill the event counters of the dead processor
6608 * into the current processors event counters.
6609 * This artificially elevates the count of the current
6612 vm_events_fold_cpu(cpu
);
6615 * Zero the differential counters of the dead processor
6616 * so that the vm statistics are consistent.
6618 * This is only okay since the processor is dead and cannot
6619 * race with what we are doing.
6621 cpu_vm_stats_fold(cpu
);
6626 void __init
page_alloc_init(void)
6628 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6632 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6633 * or min_free_kbytes changes.
6635 static void calculate_totalreserve_pages(void)
6637 struct pglist_data
*pgdat
;
6638 unsigned long reserve_pages
= 0;
6639 enum zone_type i
, j
;
6641 for_each_online_pgdat(pgdat
) {
6643 pgdat
->totalreserve_pages
= 0;
6645 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6646 struct zone
*zone
= pgdat
->node_zones
+ i
;
6649 /* Find valid and maximum lowmem_reserve in the zone */
6650 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6651 if (zone
->lowmem_reserve
[j
] > max
)
6652 max
= zone
->lowmem_reserve
[j
];
6655 /* we treat the high watermark as reserved pages. */
6656 max
+= high_wmark_pages(zone
);
6658 if (max
> zone
->managed_pages
)
6659 max
= zone
->managed_pages
;
6661 pgdat
->totalreserve_pages
+= max
;
6663 reserve_pages
+= max
;
6666 totalreserve_pages
= reserve_pages
;
6670 * setup_per_zone_lowmem_reserve - called whenever
6671 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6672 * has a correct pages reserved value, so an adequate number of
6673 * pages are left in the zone after a successful __alloc_pages().
6675 static void setup_per_zone_lowmem_reserve(void)
6677 struct pglist_data
*pgdat
;
6678 enum zone_type j
, idx
;
6680 for_each_online_pgdat(pgdat
) {
6681 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6682 struct zone
*zone
= pgdat
->node_zones
+ j
;
6683 unsigned long managed_pages
= zone
->managed_pages
;
6685 zone
->lowmem_reserve
[j
] = 0;
6689 struct zone
*lower_zone
;
6693 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6694 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6696 lower_zone
= pgdat
->node_zones
+ idx
;
6697 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6698 sysctl_lowmem_reserve_ratio
[idx
];
6699 managed_pages
+= lower_zone
->managed_pages
;
6704 /* update totalreserve_pages */
6705 calculate_totalreserve_pages();
6708 static void __setup_per_zone_wmarks(void)
6710 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6711 unsigned long lowmem_pages
= 0;
6713 unsigned long flags
;
6715 /* Calculate total number of !ZONE_HIGHMEM pages */
6716 for_each_zone(zone
) {
6717 if (!is_highmem(zone
))
6718 lowmem_pages
+= zone
->managed_pages
;
6721 for_each_zone(zone
) {
6724 spin_lock_irqsave(&zone
->lock
, flags
);
6725 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6726 do_div(tmp
, lowmem_pages
);
6727 if (is_highmem(zone
)) {
6729 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6730 * need highmem pages, so cap pages_min to a small
6733 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6734 * deltas control asynch page reclaim, and so should
6735 * not be capped for highmem.
6737 unsigned long min_pages
;
6739 min_pages
= zone
->managed_pages
/ 1024;
6740 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6741 zone
->watermark
[WMARK_MIN
] = min_pages
;
6744 * If it's a lowmem zone, reserve a number of pages
6745 * proportionate to the zone's size.
6747 zone
->watermark
[WMARK_MIN
] = tmp
;
6751 * Set the kswapd watermarks distance according to the
6752 * scale factor in proportion to available memory, but
6753 * ensure a minimum size on small systems.
6755 tmp
= max_t(u64
, tmp
>> 2,
6756 mult_frac(zone
->managed_pages
,
6757 watermark_scale_factor
, 10000));
6759 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6760 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6762 spin_unlock_irqrestore(&zone
->lock
, flags
);
6765 /* update totalreserve_pages */
6766 calculate_totalreserve_pages();
6770 * setup_per_zone_wmarks - called when min_free_kbytes changes
6771 * or when memory is hot-{added|removed}
6773 * Ensures that the watermark[min,low,high] values for each zone are set
6774 * correctly with respect to min_free_kbytes.
6776 void setup_per_zone_wmarks(void)
6778 mutex_lock(&zonelists_mutex
);
6779 __setup_per_zone_wmarks();
6780 mutex_unlock(&zonelists_mutex
);
6784 * Initialise min_free_kbytes.
6786 * For small machines we want it small (128k min). For large machines
6787 * we want it large (64MB max). But it is not linear, because network
6788 * bandwidth does not increase linearly with machine size. We use
6790 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6791 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6807 int __meminit
init_per_zone_wmark_min(void)
6809 unsigned long lowmem_kbytes
;
6810 int new_min_free_kbytes
;
6812 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6813 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6815 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6816 min_free_kbytes
= new_min_free_kbytes
;
6817 if (min_free_kbytes
< 128)
6818 min_free_kbytes
= 128;
6819 if (min_free_kbytes
> 65536)
6820 min_free_kbytes
= 65536;
6822 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6823 new_min_free_kbytes
, user_min_free_kbytes
);
6825 setup_per_zone_wmarks();
6826 refresh_zone_stat_thresholds();
6827 setup_per_zone_lowmem_reserve();
6830 core_initcall(init_per_zone_wmark_min
)
6833 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6834 * that we can call two helper functions whenever min_free_kbytes
6837 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6838 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6842 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6847 user_min_free_kbytes
= min_free_kbytes
;
6848 setup_per_zone_wmarks();
6853 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6854 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6858 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6863 setup_per_zone_wmarks();
6869 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6870 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6872 struct pglist_data
*pgdat
;
6876 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6880 for_each_online_pgdat(pgdat
)
6881 pgdat
->min_slab_pages
= 0;
6884 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
6885 sysctl_min_unmapped_ratio
) / 100;
6889 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6890 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6892 struct pglist_data
*pgdat
;
6896 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6900 for_each_online_pgdat(pgdat
)
6901 pgdat
->min_slab_pages
= 0;
6904 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
6905 sysctl_min_slab_ratio
) / 100;
6911 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6912 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6913 * whenever sysctl_lowmem_reserve_ratio changes.
6915 * The reserve ratio obviously has absolutely no relation with the
6916 * minimum watermarks. The lowmem reserve ratio can only make sense
6917 * if in function of the boot time zone sizes.
6919 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6920 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6922 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6923 setup_per_zone_lowmem_reserve();
6928 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6929 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6930 * pagelist can have before it gets flushed back to buddy allocator.
6932 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6933 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6936 int old_percpu_pagelist_fraction
;
6939 mutex_lock(&pcp_batch_high_lock
);
6940 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6942 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6943 if (!write
|| ret
< 0)
6946 /* Sanity checking to avoid pcp imbalance */
6947 if (percpu_pagelist_fraction
&&
6948 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6949 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6955 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6958 for_each_populated_zone(zone
) {
6961 for_each_possible_cpu(cpu
)
6962 pageset_set_high_and_batch(zone
,
6963 per_cpu_ptr(zone
->pageset
, cpu
));
6966 mutex_unlock(&pcp_batch_high_lock
);
6971 int hashdist
= HASHDIST_DEFAULT
;
6973 static int __init
set_hashdist(char *str
)
6977 hashdist
= simple_strtoul(str
, &str
, 0);
6980 __setup("hashdist=", set_hashdist
);
6984 * allocate a large system hash table from bootmem
6985 * - it is assumed that the hash table must contain an exact power-of-2
6986 * quantity of entries
6987 * - limit is the number of hash buckets, not the total allocation size
6989 void *__init
alloc_large_system_hash(const char *tablename
,
6990 unsigned long bucketsize
,
6991 unsigned long numentries
,
6994 unsigned int *_hash_shift
,
6995 unsigned int *_hash_mask
,
6996 unsigned long low_limit
,
6997 unsigned long high_limit
)
6999 unsigned long long max
= high_limit
;
7000 unsigned long log2qty
, size
;
7003 /* allow the kernel cmdline to have a say */
7005 /* round applicable memory size up to nearest megabyte */
7006 numentries
= nr_kernel_pages
;
7008 /* It isn't necessary when PAGE_SIZE >= 1MB */
7009 if (PAGE_SHIFT
< 20)
7010 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7012 /* limit to 1 bucket per 2^scale bytes of low memory */
7013 if (scale
> PAGE_SHIFT
)
7014 numentries
>>= (scale
- PAGE_SHIFT
);
7016 numentries
<<= (PAGE_SHIFT
- scale
);
7018 /* Make sure we've got at least a 0-order allocation.. */
7019 if (unlikely(flags
& HASH_SMALL
)) {
7020 /* Makes no sense without HASH_EARLY */
7021 WARN_ON(!(flags
& HASH_EARLY
));
7022 if (!(numentries
>> *_hash_shift
)) {
7023 numentries
= 1UL << *_hash_shift
;
7024 BUG_ON(!numentries
);
7026 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7027 numentries
= PAGE_SIZE
/ bucketsize
;
7029 numentries
= roundup_pow_of_two(numentries
);
7031 /* limit allocation size to 1/16 total memory by default */
7033 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7034 do_div(max
, bucketsize
);
7036 max
= min(max
, 0x80000000ULL
);
7038 if (numentries
< low_limit
)
7039 numentries
= low_limit
;
7040 if (numentries
> max
)
7043 log2qty
= ilog2(numentries
);
7046 size
= bucketsize
<< log2qty
;
7047 if (flags
& HASH_EARLY
)
7048 table
= memblock_virt_alloc_nopanic(size
, 0);
7050 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
7053 * If bucketsize is not a power-of-two, we may free
7054 * some pages at the end of hash table which
7055 * alloc_pages_exact() automatically does
7057 if (get_order(size
) < MAX_ORDER
) {
7058 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
7059 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
7062 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7065 panic("Failed to allocate %s hash table\n", tablename
);
7067 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7068 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7071 *_hash_shift
= log2qty
;
7073 *_hash_mask
= (1 << log2qty
) - 1;
7079 * This function checks whether pageblock includes unmovable pages or not.
7080 * If @count is not zero, it is okay to include less @count unmovable pages
7082 * PageLRU check without isolation or lru_lock could race so that
7083 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
7084 * expect this function should be exact.
7086 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7087 bool skip_hwpoisoned_pages
)
7089 unsigned long pfn
, iter
, found
;
7093 * For avoiding noise data, lru_add_drain_all() should be called
7094 * If ZONE_MOVABLE, the zone never contains unmovable pages
7096 if (zone_idx(zone
) == ZONE_MOVABLE
)
7098 mt
= get_pageblock_migratetype(page
);
7099 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7102 pfn
= page_to_pfn(page
);
7103 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7104 unsigned long check
= pfn
+ iter
;
7106 if (!pfn_valid_within(check
))
7109 page
= pfn_to_page(check
);
7112 * Hugepages are not in LRU lists, but they're movable.
7113 * We need not scan over tail pages bacause we don't
7114 * handle each tail page individually in migration.
7116 if (PageHuge(page
)) {
7117 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7122 * We can't use page_count without pin a page
7123 * because another CPU can free compound page.
7124 * This check already skips compound tails of THP
7125 * because their page->_refcount is zero at all time.
7127 if (!page_ref_count(page
)) {
7128 if (PageBuddy(page
))
7129 iter
+= (1 << page_order(page
)) - 1;
7134 * The HWPoisoned page may be not in buddy system, and
7135 * page_count() is not 0.
7137 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7143 * If there are RECLAIMABLE pages, we need to check
7144 * it. But now, memory offline itself doesn't call
7145 * shrink_node_slabs() and it still to be fixed.
7148 * If the page is not RAM, page_count()should be 0.
7149 * we don't need more check. This is an _used_ not-movable page.
7151 * The problematic thing here is PG_reserved pages. PG_reserved
7152 * is set to both of a memory hole page and a _used_ kernel
7161 bool is_pageblock_removable_nolock(struct page
*page
)
7167 * We have to be careful here because we are iterating over memory
7168 * sections which are not zone aware so we might end up outside of
7169 * the zone but still within the section.
7170 * We have to take care about the node as well. If the node is offline
7171 * its NODE_DATA will be NULL - see page_zone.
7173 if (!node_online(page_to_nid(page
)))
7176 zone
= page_zone(page
);
7177 pfn
= page_to_pfn(page
);
7178 if (!zone_spans_pfn(zone
, pfn
))
7181 return !has_unmovable_pages(zone
, page
, 0, true);
7184 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7186 static unsigned long pfn_max_align_down(unsigned long pfn
)
7188 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7189 pageblock_nr_pages
) - 1);
7192 static unsigned long pfn_max_align_up(unsigned long pfn
)
7194 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7195 pageblock_nr_pages
));
7198 /* [start, end) must belong to a single zone. */
7199 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7200 unsigned long start
, unsigned long end
)
7202 /* This function is based on compact_zone() from compaction.c. */
7203 unsigned long nr_reclaimed
;
7204 unsigned long pfn
= start
;
7205 unsigned int tries
= 0;
7210 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7211 if (fatal_signal_pending(current
)) {
7216 if (list_empty(&cc
->migratepages
)) {
7217 cc
->nr_migratepages
= 0;
7218 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7224 } else if (++tries
== 5) {
7225 ret
= ret
< 0 ? ret
: -EBUSY
;
7229 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7231 cc
->nr_migratepages
-= nr_reclaimed
;
7233 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7234 NULL
, 0, cc
->mode
, MR_CMA
);
7237 putback_movable_pages(&cc
->migratepages
);
7244 * alloc_contig_range() -- tries to allocate given range of pages
7245 * @start: start PFN to allocate
7246 * @end: one-past-the-last PFN to allocate
7247 * @migratetype: migratetype of the underlaying pageblocks (either
7248 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7249 * in range must have the same migratetype and it must
7250 * be either of the two.
7252 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7253 * aligned, however it's the caller's responsibility to guarantee that
7254 * we are the only thread that changes migrate type of pageblocks the
7257 * The PFN range must belong to a single zone.
7259 * Returns zero on success or negative error code. On success all
7260 * pages which PFN is in [start, end) are allocated for the caller and
7261 * need to be freed with free_contig_range().
7263 int alloc_contig_range(unsigned long start
, unsigned long end
,
7264 unsigned migratetype
)
7266 unsigned long outer_start
, outer_end
;
7270 struct compact_control cc
= {
7271 .nr_migratepages
= 0,
7273 .zone
= page_zone(pfn_to_page(start
)),
7274 .mode
= MIGRATE_SYNC
,
7275 .ignore_skip_hint
= true,
7277 INIT_LIST_HEAD(&cc
.migratepages
);
7280 * What we do here is we mark all pageblocks in range as
7281 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7282 * have different sizes, and due to the way page allocator
7283 * work, we align the range to biggest of the two pages so
7284 * that page allocator won't try to merge buddies from
7285 * different pageblocks and change MIGRATE_ISOLATE to some
7286 * other migration type.
7288 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7289 * migrate the pages from an unaligned range (ie. pages that
7290 * we are interested in). This will put all the pages in
7291 * range back to page allocator as MIGRATE_ISOLATE.
7293 * When this is done, we take the pages in range from page
7294 * allocator removing them from the buddy system. This way
7295 * page allocator will never consider using them.
7297 * This lets us mark the pageblocks back as
7298 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7299 * aligned range but not in the unaligned, original range are
7300 * put back to page allocator so that buddy can use them.
7303 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7304 pfn_max_align_up(end
), migratetype
,
7310 * In case of -EBUSY, we'd like to know which page causes problem.
7311 * So, just fall through. We will check it in test_pages_isolated().
7313 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7314 if (ret
&& ret
!= -EBUSY
)
7318 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7319 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7320 * more, all pages in [start, end) are free in page allocator.
7321 * What we are going to do is to allocate all pages from
7322 * [start, end) (that is remove them from page allocator).
7324 * The only problem is that pages at the beginning and at the
7325 * end of interesting range may be not aligned with pages that
7326 * page allocator holds, ie. they can be part of higher order
7327 * pages. Because of this, we reserve the bigger range and
7328 * once this is done free the pages we are not interested in.
7330 * We don't have to hold zone->lock here because the pages are
7331 * isolated thus they won't get removed from buddy.
7334 lru_add_drain_all();
7335 drain_all_pages(cc
.zone
);
7338 outer_start
= start
;
7339 while (!PageBuddy(pfn_to_page(outer_start
))) {
7340 if (++order
>= MAX_ORDER
) {
7341 outer_start
= start
;
7344 outer_start
&= ~0UL << order
;
7347 if (outer_start
!= start
) {
7348 order
= page_order(pfn_to_page(outer_start
));
7351 * outer_start page could be small order buddy page and
7352 * it doesn't include start page. Adjust outer_start
7353 * in this case to report failed page properly
7354 * on tracepoint in test_pages_isolated()
7356 if (outer_start
+ (1UL << order
) <= start
)
7357 outer_start
= start
;
7360 /* Make sure the range is really isolated. */
7361 if (test_pages_isolated(outer_start
, end
, false)) {
7362 pr_info("%s: [%lx, %lx) PFNs busy\n",
7363 __func__
, outer_start
, end
);
7368 /* Grab isolated pages from freelists. */
7369 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7375 /* Free head and tail (if any) */
7376 if (start
!= outer_start
)
7377 free_contig_range(outer_start
, start
- outer_start
);
7378 if (end
!= outer_end
)
7379 free_contig_range(end
, outer_end
- end
);
7382 undo_isolate_page_range(pfn_max_align_down(start
),
7383 pfn_max_align_up(end
), migratetype
);
7387 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7389 unsigned int count
= 0;
7391 for (; nr_pages
--; pfn
++) {
7392 struct page
*page
= pfn_to_page(pfn
);
7394 count
+= page_count(page
) != 1;
7397 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7401 #ifdef CONFIG_MEMORY_HOTPLUG
7403 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7404 * page high values need to be recalulated.
7406 void __meminit
zone_pcp_update(struct zone
*zone
)
7409 mutex_lock(&pcp_batch_high_lock
);
7410 for_each_possible_cpu(cpu
)
7411 pageset_set_high_and_batch(zone
,
7412 per_cpu_ptr(zone
->pageset
, cpu
));
7413 mutex_unlock(&pcp_batch_high_lock
);
7417 void zone_pcp_reset(struct zone
*zone
)
7419 unsigned long flags
;
7421 struct per_cpu_pageset
*pset
;
7423 /* avoid races with drain_pages() */
7424 local_irq_save(flags
);
7425 if (zone
->pageset
!= &boot_pageset
) {
7426 for_each_online_cpu(cpu
) {
7427 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7428 drain_zonestat(zone
, pset
);
7430 free_percpu(zone
->pageset
);
7431 zone
->pageset
= &boot_pageset
;
7433 local_irq_restore(flags
);
7436 #ifdef CONFIG_MEMORY_HOTREMOVE
7438 * All pages in the range must be in a single zone and isolated
7439 * before calling this.
7442 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7446 unsigned int order
, i
;
7448 unsigned long flags
;
7449 /* find the first valid pfn */
7450 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7455 zone
= page_zone(pfn_to_page(pfn
));
7456 spin_lock_irqsave(&zone
->lock
, flags
);
7458 while (pfn
< end_pfn
) {
7459 if (!pfn_valid(pfn
)) {
7463 page
= pfn_to_page(pfn
);
7465 * The HWPoisoned page may be not in buddy system, and
7466 * page_count() is not 0.
7468 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7470 SetPageReserved(page
);
7474 BUG_ON(page_count(page
));
7475 BUG_ON(!PageBuddy(page
));
7476 order
= page_order(page
);
7477 #ifdef CONFIG_DEBUG_VM
7478 pr_info("remove from free list %lx %d %lx\n",
7479 pfn
, 1 << order
, end_pfn
);
7481 list_del(&page
->lru
);
7482 rmv_page_order(page
);
7483 zone
->free_area
[order
].nr_free
--;
7484 for (i
= 0; i
< (1 << order
); i
++)
7485 SetPageReserved((page
+i
));
7486 pfn
+= (1 << order
);
7488 spin_unlock_irqrestore(&zone
->lock
, flags
);
7492 bool is_free_buddy_page(struct page
*page
)
7494 struct zone
*zone
= page_zone(page
);
7495 unsigned long pfn
= page_to_pfn(page
);
7496 unsigned long flags
;
7499 spin_lock_irqsave(&zone
->lock
, flags
);
7500 for (order
= 0; order
< MAX_ORDER
; order
++) {
7501 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7503 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7506 spin_unlock_irqrestore(&zone
->lock
, flags
);
7508 return order
< MAX_ORDER
;