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 <trace/events/oom.h>
59 #include <linux/prefetch.h>
60 #include <linux/mm_inline.h>
61 #include <linux/migrate.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/sched/mm.h>
65 #include <linux/page_owner.h>
66 #include <linux/kthread.h>
67 #include <linux/memcontrol.h>
68 #include <linux/ftrace.h>
70 #include <asm/sections.h>
71 #include <asm/tlbflush.h>
72 #include <asm/div64.h>
75 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
76 static DEFINE_MUTEX(pcp_batch_high_lock
);
77 #define MIN_PERCPU_PAGELIST_FRACTION (8)
79 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
80 DEFINE_PER_CPU(int, numa_node
);
81 EXPORT_PER_CPU_SYMBOL(numa_node
);
84 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
86 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
87 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
88 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
89 * defined in <linux/topology.h>.
91 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
92 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
93 int _node_numa_mem_
[MAX_NUMNODES
];
96 /* work_structs for global per-cpu drains */
97 DEFINE_MUTEX(pcpu_drain_mutex
);
98 DEFINE_PER_CPU(struct work_struct
, pcpu_drain
);
100 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
101 volatile unsigned long latent_entropy __latent_entropy
;
102 EXPORT_SYMBOL(latent_entropy
);
106 * Array of node states.
108 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
109 [N_POSSIBLE
] = NODE_MASK_ALL
,
110 [N_ONLINE
] = { { [0] = 1UL } },
112 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
113 #ifdef CONFIG_HIGHMEM
114 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
116 [N_MEMORY
] = { { [0] = 1UL } },
117 [N_CPU
] = { { [0] = 1UL } },
120 EXPORT_SYMBOL(node_states
);
122 /* Protect totalram_pages and zone->managed_pages */
123 static DEFINE_SPINLOCK(managed_page_count_lock
);
125 unsigned long totalram_pages __read_mostly
;
126 unsigned long totalreserve_pages __read_mostly
;
127 unsigned long totalcma_pages __read_mostly
;
129 int percpu_pagelist_fraction
;
130 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
133 * A cached value of the page's pageblock's migratetype, used when the page is
134 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
135 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
136 * Also the migratetype set in the page does not necessarily match the pcplist
137 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
138 * other index - this ensures that it will be put on the correct CMA freelist.
140 static inline int get_pcppage_migratetype(struct page
*page
)
145 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
147 page
->index
= migratetype
;
150 #ifdef CONFIG_PM_SLEEP
152 * The following functions are used by the suspend/hibernate code to temporarily
153 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
154 * while devices are suspended. To avoid races with the suspend/hibernate code,
155 * they should always be called with pm_mutex held (gfp_allowed_mask also should
156 * only be modified with pm_mutex held, unless the suspend/hibernate code is
157 * guaranteed not to run in parallel with that modification).
160 static gfp_t saved_gfp_mask
;
162 void pm_restore_gfp_mask(void)
164 WARN_ON(!mutex_is_locked(&pm_mutex
));
165 if (saved_gfp_mask
) {
166 gfp_allowed_mask
= saved_gfp_mask
;
171 void pm_restrict_gfp_mask(void)
173 WARN_ON(!mutex_is_locked(&pm_mutex
));
174 WARN_ON(saved_gfp_mask
);
175 saved_gfp_mask
= gfp_allowed_mask
;
176 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
179 bool pm_suspended_storage(void)
181 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
185 #endif /* CONFIG_PM_SLEEP */
187 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
188 unsigned int pageblock_order __read_mostly
;
191 static void __free_pages_ok(struct page
*page
, unsigned int order
);
194 * results with 256, 32 in the lowmem_reserve sysctl:
195 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
196 * 1G machine -> (16M dma, 784M normal, 224M high)
197 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
198 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
199 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
201 * TBD: should special case ZONE_DMA32 machines here - in those we normally
202 * don't need any ZONE_NORMAL reservation
204 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
205 #ifdef CONFIG_ZONE_DMA
208 #ifdef CONFIG_ZONE_DMA32
211 #ifdef CONFIG_HIGHMEM
217 EXPORT_SYMBOL(totalram_pages
);
219 static char * const zone_names
[MAX_NR_ZONES
] = {
220 #ifdef CONFIG_ZONE_DMA
223 #ifdef CONFIG_ZONE_DMA32
227 #ifdef CONFIG_HIGHMEM
231 #ifdef CONFIG_ZONE_DEVICE
236 char * const migratetype_names
[MIGRATE_TYPES
] = {
244 #ifdef CONFIG_MEMORY_ISOLATION
249 compound_page_dtor
* const compound_page_dtors
[] = {
252 #ifdef CONFIG_HUGETLB_PAGE
255 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
260 int min_free_kbytes
= 1024;
261 int user_min_free_kbytes
= -1;
262 int watermark_scale_factor
= 10;
264 static unsigned long __meminitdata nr_kernel_pages
;
265 static unsigned long __meminitdata nr_all_pages
;
266 static unsigned long __meminitdata dma_reserve
;
268 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
269 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
270 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
271 static unsigned long __initdata required_kernelcore
;
272 static unsigned long __initdata required_movablecore
;
273 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
274 static bool mirrored_kernelcore
;
276 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
278 EXPORT_SYMBOL(movable_zone
);
279 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
282 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
283 int nr_online_nodes __read_mostly
= 1;
284 EXPORT_SYMBOL(nr_node_ids
);
285 EXPORT_SYMBOL(nr_online_nodes
);
288 int page_group_by_mobility_disabled __read_mostly
;
290 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
291 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
293 unsigned long max_initialise
;
294 unsigned long reserved_lowmem
;
297 * Initialise at least 2G of a node but also take into account that
298 * two large system hashes that can take up 1GB for 0.25TB/node.
300 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
301 (pgdat
->node_spanned_pages
>> 8));
304 * Compensate the all the memblock reservations (e.g. crash kernel)
305 * from the initial estimation to make sure we will initialize enough
308 reserved_lowmem
= memblock_reserved_memory_within(pgdat
->node_start_pfn
,
309 pgdat
->node_start_pfn
+ max_initialise
);
310 max_initialise
+= reserved_lowmem
;
312 pgdat
->static_init_size
= min(max_initialise
, pgdat
->node_spanned_pages
);
313 pgdat
->first_deferred_pfn
= ULONG_MAX
;
316 /* Returns true if the struct page for the pfn is uninitialised */
317 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
319 int nid
= early_pfn_to_nid(pfn
);
321 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
328 * Returns false when the remaining initialisation should be deferred until
329 * later in the boot cycle when it can be parallelised.
331 static inline bool update_defer_init(pg_data_t
*pgdat
,
332 unsigned long pfn
, unsigned long zone_end
,
333 unsigned long *nr_initialised
)
335 /* Always populate low zones for address-contrained allocations */
336 if (zone_end
< pgdat_end_pfn(pgdat
))
339 if ((*nr_initialised
> pgdat
->static_init_size
) &&
340 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
341 pgdat
->first_deferred_pfn
= pfn
;
348 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
352 static inline bool early_page_uninitialised(unsigned long pfn
)
357 static inline bool update_defer_init(pg_data_t
*pgdat
,
358 unsigned long pfn
, unsigned long zone_end
,
359 unsigned long *nr_initialised
)
365 /* Return a pointer to the bitmap storing bits affecting a block of pages */
366 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
369 #ifdef CONFIG_SPARSEMEM
370 return __pfn_to_section(pfn
)->pageblock_flags
;
372 return page_zone(page
)->pageblock_flags
;
373 #endif /* CONFIG_SPARSEMEM */
376 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
378 #ifdef CONFIG_SPARSEMEM
379 pfn
&= (PAGES_PER_SECTION
-1);
380 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
382 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
383 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
384 #endif /* CONFIG_SPARSEMEM */
388 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
389 * @page: The page within the block of interest
390 * @pfn: The target page frame number
391 * @end_bitidx: The last bit of interest to retrieve
392 * @mask: mask of bits that the caller is interested in
394 * Return: pageblock_bits flags
396 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
398 unsigned long end_bitidx
,
401 unsigned long *bitmap
;
402 unsigned long bitidx
, word_bitidx
;
405 bitmap
= get_pageblock_bitmap(page
, pfn
);
406 bitidx
= pfn_to_bitidx(page
, pfn
);
407 word_bitidx
= bitidx
/ BITS_PER_LONG
;
408 bitidx
&= (BITS_PER_LONG
-1);
410 word
= bitmap
[word_bitidx
];
411 bitidx
+= end_bitidx
;
412 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
415 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
416 unsigned long end_bitidx
,
419 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
422 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
424 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
428 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
429 * @page: The page within the block of interest
430 * @flags: The flags to set
431 * @pfn: The target page frame number
432 * @end_bitidx: The last bit of interest
433 * @mask: mask of bits that the caller is interested in
435 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
437 unsigned long end_bitidx
,
440 unsigned long *bitmap
;
441 unsigned long bitidx
, word_bitidx
;
442 unsigned long old_word
, word
;
444 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
446 bitmap
= get_pageblock_bitmap(page
, pfn
);
447 bitidx
= pfn_to_bitidx(page
, pfn
);
448 word_bitidx
= bitidx
/ BITS_PER_LONG
;
449 bitidx
&= (BITS_PER_LONG
-1);
451 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
453 bitidx
+= end_bitidx
;
454 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
455 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
457 word
= READ_ONCE(bitmap
[word_bitidx
]);
459 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
460 if (word
== old_word
)
466 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
468 if (unlikely(page_group_by_mobility_disabled
&&
469 migratetype
< MIGRATE_PCPTYPES
))
470 migratetype
= MIGRATE_UNMOVABLE
;
472 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
473 PB_migrate
, PB_migrate_end
);
476 #ifdef CONFIG_DEBUG_VM
477 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
481 unsigned long pfn
= page_to_pfn(page
);
482 unsigned long sp
, start_pfn
;
485 seq
= zone_span_seqbegin(zone
);
486 start_pfn
= zone
->zone_start_pfn
;
487 sp
= zone
->spanned_pages
;
488 if (!zone_spans_pfn(zone
, pfn
))
490 } while (zone_span_seqretry(zone
, seq
));
493 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
494 pfn
, zone_to_nid(zone
), zone
->name
,
495 start_pfn
, start_pfn
+ sp
);
500 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
502 if (!pfn_valid_within(page_to_pfn(page
)))
504 if (zone
!= page_zone(page
))
510 * Temporary debugging check for pages not lying within a given zone.
512 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
514 if (page_outside_zone_boundaries(zone
, page
))
516 if (!page_is_consistent(zone
, page
))
522 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
528 static void bad_page(struct page
*page
, const char *reason
,
529 unsigned long bad_flags
)
531 static unsigned long resume
;
532 static unsigned long nr_shown
;
533 static unsigned long nr_unshown
;
536 * Allow a burst of 60 reports, then keep quiet for that minute;
537 * or allow a steady drip of one report per second.
539 if (nr_shown
== 60) {
540 if (time_before(jiffies
, resume
)) {
546 "BUG: Bad page state: %lu messages suppressed\n",
553 resume
= jiffies
+ 60 * HZ
;
555 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
556 current
->comm
, page_to_pfn(page
));
557 __dump_page(page
, reason
);
558 bad_flags
&= page
->flags
;
560 pr_alert("bad because of flags: %#lx(%pGp)\n",
561 bad_flags
, &bad_flags
);
562 dump_page_owner(page
);
567 /* Leave bad fields for debug, except PageBuddy could make trouble */
568 page_mapcount_reset(page
); /* remove PageBuddy */
569 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
573 * Higher-order pages are called "compound pages". They are structured thusly:
575 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
577 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
578 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
580 * The first tail page's ->compound_dtor holds the offset in array of compound
581 * page destructors. See compound_page_dtors.
583 * The first tail page's ->compound_order holds the order of allocation.
584 * This usage means that zero-order pages may not be compound.
587 void free_compound_page(struct page
*page
)
589 __free_pages_ok(page
, compound_order(page
));
592 void prep_compound_page(struct page
*page
, unsigned int order
)
595 int nr_pages
= 1 << order
;
597 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
598 set_compound_order(page
, order
);
600 for (i
= 1; i
< nr_pages
; i
++) {
601 struct page
*p
= page
+ i
;
602 set_page_count(p
, 0);
603 p
->mapping
= TAIL_MAPPING
;
604 set_compound_head(p
, page
);
606 atomic_set(compound_mapcount_ptr(page
), -1);
609 #ifdef CONFIG_DEBUG_PAGEALLOC
610 unsigned int _debug_guardpage_minorder
;
611 bool _debug_pagealloc_enabled __read_mostly
612 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
613 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
614 bool _debug_guardpage_enabled __read_mostly
;
616 static int __init
early_debug_pagealloc(char *buf
)
620 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
622 early_param("debug_pagealloc", early_debug_pagealloc
);
624 static bool need_debug_guardpage(void)
626 /* If we don't use debug_pagealloc, we don't need guard page */
627 if (!debug_pagealloc_enabled())
630 if (!debug_guardpage_minorder())
636 static void init_debug_guardpage(void)
638 if (!debug_pagealloc_enabled())
641 if (!debug_guardpage_minorder())
644 _debug_guardpage_enabled
= true;
647 struct page_ext_operations debug_guardpage_ops
= {
648 .need
= need_debug_guardpage
,
649 .init
= init_debug_guardpage
,
652 static int __init
debug_guardpage_minorder_setup(char *buf
)
656 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
657 pr_err("Bad debug_guardpage_minorder value\n");
660 _debug_guardpage_minorder
= res
;
661 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
664 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
666 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
667 unsigned int order
, int migratetype
)
669 struct page_ext
*page_ext
;
671 if (!debug_guardpage_enabled())
674 if (order
>= debug_guardpage_minorder())
677 page_ext
= lookup_page_ext(page
);
678 if (unlikely(!page_ext
))
681 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
683 INIT_LIST_HEAD(&page
->lru
);
684 set_page_private(page
, order
);
685 /* Guard pages are not available for any usage */
686 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
691 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
692 unsigned int order
, int migratetype
)
694 struct page_ext
*page_ext
;
696 if (!debug_guardpage_enabled())
699 page_ext
= lookup_page_ext(page
);
700 if (unlikely(!page_ext
))
703 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
705 set_page_private(page
, 0);
706 if (!is_migrate_isolate(migratetype
))
707 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
710 struct page_ext_operations debug_guardpage_ops
;
711 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
712 unsigned int order
, int migratetype
) { return false; }
713 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
714 unsigned int order
, int migratetype
) {}
717 static inline void set_page_order(struct page
*page
, unsigned int order
)
719 set_page_private(page
, order
);
720 __SetPageBuddy(page
);
723 static inline void rmv_page_order(struct page
*page
)
725 __ClearPageBuddy(page
);
726 set_page_private(page
, 0);
730 * This function checks whether a page is free && is the buddy
731 * we can do coalesce a page and its buddy if
732 * (a) the buddy is not in a hole (check before calling!) &&
733 * (b) the buddy is in the buddy system &&
734 * (c) a page and its buddy have the same order &&
735 * (d) a page and its buddy are in the same zone.
737 * For recording whether a page is in the buddy system, we set ->_mapcount
738 * PAGE_BUDDY_MAPCOUNT_VALUE.
739 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
740 * serialized by zone->lock.
742 * For recording page's order, we use page_private(page).
744 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
747 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
748 if (page_zone_id(page
) != page_zone_id(buddy
))
751 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
756 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
758 * zone check is done late to avoid uselessly
759 * calculating zone/node ids for pages that could
762 if (page_zone_id(page
) != page_zone_id(buddy
))
765 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
773 * Freeing function for a buddy system allocator.
775 * The concept of a buddy system is to maintain direct-mapped table
776 * (containing bit values) for memory blocks of various "orders".
777 * The bottom level table contains the map for the smallest allocatable
778 * units of memory (here, pages), and each level above it describes
779 * pairs of units from the levels below, hence, "buddies".
780 * At a high level, all that happens here is marking the table entry
781 * at the bottom level available, and propagating the changes upward
782 * as necessary, plus some accounting needed to play nicely with other
783 * parts of the VM system.
784 * At each level, we keep a list of pages, which are heads of continuous
785 * free pages of length of (1 << order) and marked with _mapcount
786 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
788 * So when we are allocating or freeing one, we can derive the state of the
789 * other. That is, if we allocate a small block, and both were
790 * free, the remainder of the region must be split into blocks.
791 * If a block is freed, and its buddy is also free, then this
792 * triggers coalescing into a block of larger size.
797 static inline void __free_one_page(struct page
*page
,
799 struct zone
*zone
, unsigned int order
,
802 unsigned long combined_pfn
;
803 unsigned long uninitialized_var(buddy_pfn
);
805 unsigned int max_order
;
807 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
809 VM_BUG_ON(!zone_is_initialized(zone
));
810 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
812 VM_BUG_ON(migratetype
== -1);
813 if (likely(!is_migrate_isolate(migratetype
)))
814 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
816 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
817 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
820 while (order
< max_order
- 1) {
821 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
822 buddy
= page
+ (buddy_pfn
- pfn
);
824 if (!pfn_valid_within(buddy_pfn
))
826 if (!page_is_buddy(page
, buddy
, order
))
829 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
830 * merge with it and move up one order.
832 if (page_is_guard(buddy
)) {
833 clear_page_guard(zone
, buddy
, order
, migratetype
);
835 list_del(&buddy
->lru
);
836 zone
->free_area
[order
].nr_free
--;
837 rmv_page_order(buddy
);
839 combined_pfn
= buddy_pfn
& pfn
;
840 page
= page
+ (combined_pfn
- pfn
);
844 if (max_order
< MAX_ORDER
) {
845 /* If we are here, it means order is >= pageblock_order.
846 * We want to prevent merge between freepages on isolate
847 * pageblock and normal pageblock. Without this, pageblock
848 * isolation could cause incorrect freepage or CMA accounting.
850 * We don't want to hit this code for the more frequent
853 if (unlikely(has_isolate_pageblock(zone
))) {
856 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
857 buddy
= page
+ (buddy_pfn
- pfn
);
858 buddy_mt
= get_pageblock_migratetype(buddy
);
860 if (migratetype
!= buddy_mt
861 && (is_migrate_isolate(migratetype
) ||
862 is_migrate_isolate(buddy_mt
)))
866 goto continue_merging
;
870 set_page_order(page
, order
);
873 * If this is not the largest possible page, check if the buddy
874 * of the next-highest order is free. If it is, it's possible
875 * that pages are being freed that will coalesce soon. In case,
876 * that is happening, add the free page to the tail of the list
877 * so it's less likely to be used soon and more likely to be merged
878 * as a higher order page
880 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)) {
881 struct page
*higher_page
, *higher_buddy
;
882 combined_pfn
= buddy_pfn
& pfn
;
883 higher_page
= page
+ (combined_pfn
- pfn
);
884 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
885 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
886 if (pfn_valid_within(buddy_pfn
) &&
887 page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
888 list_add_tail(&page
->lru
,
889 &zone
->free_area
[order
].free_list
[migratetype
]);
894 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
896 zone
->free_area
[order
].nr_free
++;
900 * A bad page could be due to a number of fields. Instead of multiple branches,
901 * try and check multiple fields with one check. The caller must do a detailed
902 * check if necessary.
904 static inline bool page_expected_state(struct page
*page
,
905 unsigned long check_flags
)
907 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
910 if (unlikely((unsigned long)page
->mapping
|
911 page_ref_count(page
) |
913 (unsigned long)page
->mem_cgroup
|
915 (page
->flags
& check_flags
)))
921 static void free_pages_check_bad(struct page
*page
)
923 const char *bad_reason
;
924 unsigned long bad_flags
;
929 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
930 bad_reason
= "nonzero mapcount";
931 if (unlikely(page
->mapping
!= NULL
))
932 bad_reason
= "non-NULL mapping";
933 if (unlikely(page_ref_count(page
) != 0))
934 bad_reason
= "nonzero _refcount";
935 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
936 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
937 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
940 if (unlikely(page
->mem_cgroup
))
941 bad_reason
= "page still charged to cgroup";
943 bad_page(page
, bad_reason
, bad_flags
);
946 static inline int free_pages_check(struct page
*page
)
948 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
951 /* Something has gone sideways, find it */
952 free_pages_check_bad(page
);
956 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
961 * We rely page->lru.next never has bit 0 set, unless the page
962 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
964 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
966 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
970 switch (page
- head_page
) {
972 /* the first tail page: ->mapping is compound_mapcount() */
973 if (unlikely(compound_mapcount(page
))) {
974 bad_page(page
, "nonzero compound_mapcount", 0);
980 * the second tail page: ->mapping is
981 * page_deferred_list().next -- ignore value.
985 if (page
->mapping
!= TAIL_MAPPING
) {
986 bad_page(page
, "corrupted mapping in tail page", 0);
991 if (unlikely(!PageTail(page
))) {
992 bad_page(page
, "PageTail not set", 0);
995 if (unlikely(compound_head(page
) != head_page
)) {
996 bad_page(page
, "compound_head not consistent", 0);
1001 page
->mapping
= NULL
;
1002 clear_compound_head(page
);
1006 static __always_inline
bool free_pages_prepare(struct page
*page
,
1007 unsigned int order
, bool check_free
)
1011 VM_BUG_ON_PAGE(PageTail(page
), page
);
1013 trace_mm_page_free(page
, order
);
1014 kmemcheck_free_shadow(page
, order
);
1017 * Check tail pages before head page information is cleared to
1018 * avoid checking PageCompound for order-0 pages.
1020 if (unlikely(order
)) {
1021 bool compound
= PageCompound(page
);
1024 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1027 ClearPageDoubleMap(page
);
1028 for (i
= 1; i
< (1 << order
); i
++) {
1030 bad
+= free_tail_pages_check(page
, page
+ i
);
1031 if (unlikely(free_pages_check(page
+ i
))) {
1035 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1038 if (PageMappingFlags(page
))
1039 page
->mapping
= NULL
;
1040 if (memcg_kmem_enabled() && PageKmemcg(page
))
1041 memcg_kmem_uncharge(page
, order
);
1043 bad
+= free_pages_check(page
);
1047 page_cpupid_reset_last(page
);
1048 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1049 reset_page_owner(page
, order
);
1051 if (!PageHighMem(page
)) {
1052 debug_check_no_locks_freed(page_address(page
),
1053 PAGE_SIZE
<< order
);
1054 debug_check_no_obj_freed(page_address(page
),
1055 PAGE_SIZE
<< order
);
1057 arch_free_page(page
, order
);
1058 kernel_poison_pages(page
, 1 << order
, 0);
1059 kernel_map_pages(page
, 1 << order
, 0);
1060 kasan_free_pages(page
, order
);
1065 #ifdef CONFIG_DEBUG_VM
1066 static inline bool free_pcp_prepare(struct page
*page
)
1068 return free_pages_prepare(page
, 0, true);
1071 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1076 static bool free_pcp_prepare(struct page
*page
)
1078 return free_pages_prepare(page
, 0, false);
1081 static bool bulkfree_pcp_prepare(struct page
*page
)
1083 return free_pages_check(page
);
1085 #endif /* CONFIG_DEBUG_VM */
1088 * Frees a number of pages from the PCP lists
1089 * Assumes all pages on list are in same zone, and of same order.
1090 * count is the number of pages to free.
1092 * If the zone was previously in an "all pages pinned" state then look to
1093 * see if this freeing clears that state.
1095 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1096 * pinned" detection logic.
1098 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1099 struct per_cpu_pages
*pcp
)
1101 int migratetype
= 0;
1103 bool isolated_pageblocks
;
1105 spin_lock(&zone
->lock
);
1106 isolated_pageblocks
= has_isolate_pageblock(zone
);
1110 struct list_head
*list
;
1113 * Remove pages from lists in a round-robin fashion. A
1114 * batch_free count is maintained that is incremented when an
1115 * empty list is encountered. This is so more pages are freed
1116 * off fuller lists instead of spinning excessively around empty
1121 if (++migratetype
== MIGRATE_PCPTYPES
)
1123 list
= &pcp
->lists
[migratetype
];
1124 } while (list_empty(list
));
1126 /* This is the only non-empty list. Free them all. */
1127 if (batch_free
== MIGRATE_PCPTYPES
)
1131 int mt
; /* migratetype of the to-be-freed page */
1133 page
= list_last_entry(list
, struct page
, lru
);
1134 /* must delete as __free_one_page list manipulates */
1135 list_del(&page
->lru
);
1137 mt
= get_pcppage_migratetype(page
);
1138 /* MIGRATE_ISOLATE page should not go to pcplists */
1139 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1140 /* Pageblock could have been isolated meanwhile */
1141 if (unlikely(isolated_pageblocks
))
1142 mt
= get_pageblock_migratetype(page
);
1144 if (bulkfree_pcp_prepare(page
))
1147 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1148 trace_mm_page_pcpu_drain(page
, 0, mt
);
1149 } while (--count
&& --batch_free
&& !list_empty(list
));
1151 spin_unlock(&zone
->lock
);
1154 static void free_one_page(struct zone
*zone
,
1155 struct page
*page
, unsigned long pfn
,
1159 spin_lock(&zone
->lock
);
1160 if (unlikely(has_isolate_pageblock(zone
) ||
1161 is_migrate_isolate(migratetype
))) {
1162 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1164 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1165 spin_unlock(&zone
->lock
);
1168 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1169 unsigned long zone
, int nid
)
1171 set_page_links(page
, zone
, nid
, pfn
);
1172 init_page_count(page
);
1173 page_mapcount_reset(page
);
1174 page_cpupid_reset_last(page
);
1176 INIT_LIST_HEAD(&page
->lru
);
1177 #ifdef WANT_PAGE_VIRTUAL
1178 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1179 if (!is_highmem_idx(zone
))
1180 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1184 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1187 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1190 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1191 static void init_reserved_page(unsigned long pfn
)
1196 if (!early_page_uninitialised(pfn
))
1199 nid
= early_pfn_to_nid(pfn
);
1200 pgdat
= NODE_DATA(nid
);
1202 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1203 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1205 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1208 __init_single_pfn(pfn
, zid
, nid
);
1211 static inline void init_reserved_page(unsigned long pfn
)
1214 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1217 * Initialised pages do not have PageReserved set. This function is
1218 * called for each range allocated by the bootmem allocator and
1219 * marks the pages PageReserved. The remaining valid pages are later
1220 * sent to the buddy page allocator.
1222 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1224 unsigned long start_pfn
= PFN_DOWN(start
);
1225 unsigned long end_pfn
= PFN_UP(end
);
1227 for (; start_pfn
< end_pfn
; start_pfn
++) {
1228 if (pfn_valid(start_pfn
)) {
1229 struct page
*page
= pfn_to_page(start_pfn
);
1231 init_reserved_page(start_pfn
);
1233 /* Avoid false-positive PageTail() */
1234 INIT_LIST_HEAD(&page
->lru
);
1236 SetPageReserved(page
);
1241 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1243 unsigned long flags
;
1245 unsigned long pfn
= page_to_pfn(page
);
1247 if (!free_pages_prepare(page
, order
, true))
1250 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1251 local_irq_save(flags
);
1252 __count_vm_events(PGFREE
, 1 << order
);
1253 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1254 local_irq_restore(flags
);
1257 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1259 unsigned int nr_pages
= 1 << order
;
1260 struct page
*p
= page
;
1264 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1266 __ClearPageReserved(p
);
1267 set_page_count(p
, 0);
1269 __ClearPageReserved(p
);
1270 set_page_count(p
, 0);
1272 page_zone(page
)->managed_pages
+= nr_pages
;
1273 set_page_refcounted(page
);
1274 __free_pages(page
, order
);
1277 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1278 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1280 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1282 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1284 static DEFINE_SPINLOCK(early_pfn_lock
);
1287 spin_lock(&early_pfn_lock
);
1288 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1290 nid
= first_online_node
;
1291 spin_unlock(&early_pfn_lock
);
1297 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1298 static inline bool __meminit __maybe_unused
1299 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1300 struct mminit_pfnnid_cache
*state
)
1304 nid
= __early_pfn_to_nid(pfn
, state
);
1305 if (nid
>= 0 && nid
!= node
)
1310 /* Only safe to use early in boot when initialisation is single-threaded */
1311 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1313 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1318 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1322 static inline bool __meminit __maybe_unused
1323 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1324 struct mminit_pfnnid_cache
*state
)
1331 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1334 if (early_page_uninitialised(pfn
))
1336 return __free_pages_boot_core(page
, order
);
1340 * Check that the whole (or subset of) a pageblock given by the interval of
1341 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1342 * with the migration of free compaction scanner. The scanners then need to
1343 * use only pfn_valid_within() check for arches that allow holes within
1346 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1348 * It's possible on some configurations to have a setup like node0 node1 node0
1349 * i.e. it's possible that all pages within a zones range of pages do not
1350 * belong to a single zone. We assume that a border between node0 and node1
1351 * can occur within a single pageblock, but not a node0 node1 node0
1352 * interleaving within a single pageblock. It is therefore sufficient to check
1353 * the first and last page of a pageblock and avoid checking each individual
1354 * page in a pageblock.
1356 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1357 unsigned long end_pfn
, struct zone
*zone
)
1359 struct page
*start_page
;
1360 struct page
*end_page
;
1362 /* end_pfn is one past the range we are checking */
1365 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1368 start_page
= pfn_to_online_page(start_pfn
);
1372 if (page_zone(start_page
) != zone
)
1375 end_page
= pfn_to_page(end_pfn
);
1377 /* This gives a shorter code than deriving page_zone(end_page) */
1378 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1384 void set_zone_contiguous(struct zone
*zone
)
1386 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1387 unsigned long block_end_pfn
;
1389 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1390 for (; block_start_pfn
< zone_end_pfn(zone
);
1391 block_start_pfn
= block_end_pfn
,
1392 block_end_pfn
+= pageblock_nr_pages
) {
1394 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1396 if (!__pageblock_pfn_to_page(block_start_pfn
,
1397 block_end_pfn
, zone
))
1401 /* We confirm that there is no hole */
1402 zone
->contiguous
= true;
1405 void clear_zone_contiguous(struct zone
*zone
)
1407 zone
->contiguous
= false;
1410 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1411 static void __init
deferred_free_range(struct page
*page
,
1412 unsigned long pfn
, int nr_pages
)
1419 /* Free a large naturally-aligned chunk if possible */
1420 if (nr_pages
== pageblock_nr_pages
&&
1421 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1422 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1423 __free_pages_boot_core(page
, pageblock_order
);
1427 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1428 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1429 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1430 __free_pages_boot_core(page
, 0);
1434 /* Completion tracking for deferred_init_memmap() threads */
1435 static atomic_t pgdat_init_n_undone __initdata
;
1436 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1438 static inline void __init
pgdat_init_report_one_done(void)
1440 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1441 complete(&pgdat_init_all_done_comp
);
1444 /* Initialise remaining memory on a node */
1445 static int __init
deferred_init_memmap(void *data
)
1447 pg_data_t
*pgdat
= data
;
1448 int nid
= pgdat
->node_id
;
1449 struct mminit_pfnnid_cache nid_init_state
= { };
1450 unsigned long start
= jiffies
;
1451 unsigned long nr_pages
= 0;
1452 unsigned long walk_start
, walk_end
;
1455 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1456 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1458 if (first_init_pfn
== ULONG_MAX
) {
1459 pgdat_init_report_one_done();
1463 /* Bind memory initialisation thread to a local node if possible */
1464 if (!cpumask_empty(cpumask
))
1465 set_cpus_allowed_ptr(current
, cpumask
);
1467 /* Sanity check boundaries */
1468 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1469 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1470 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1472 /* Only the highest zone is deferred so find it */
1473 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1474 zone
= pgdat
->node_zones
+ zid
;
1475 if (first_init_pfn
< zone_end_pfn(zone
))
1479 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1480 unsigned long pfn
, end_pfn
;
1481 struct page
*page
= NULL
;
1482 struct page
*free_base_page
= NULL
;
1483 unsigned long free_base_pfn
= 0;
1486 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1487 pfn
= first_init_pfn
;
1488 if (pfn
< walk_start
)
1490 if (pfn
< zone
->zone_start_pfn
)
1491 pfn
= zone
->zone_start_pfn
;
1493 for (; pfn
< end_pfn
; pfn
++) {
1494 if (!pfn_valid_within(pfn
))
1498 * Ensure pfn_valid is checked every
1499 * pageblock_nr_pages for memory holes
1501 if ((pfn
& (pageblock_nr_pages
- 1)) == 0) {
1502 if (!pfn_valid(pfn
)) {
1508 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1513 /* Minimise pfn page lookups and scheduler checks */
1514 if (page
&& (pfn
& (pageblock_nr_pages
- 1)) != 0) {
1517 nr_pages
+= nr_to_free
;
1518 deferred_free_range(free_base_page
,
1519 free_base_pfn
, nr_to_free
);
1520 free_base_page
= NULL
;
1521 free_base_pfn
= nr_to_free
= 0;
1523 page
= pfn_to_page(pfn
);
1528 VM_BUG_ON(page_zone(page
) != zone
);
1532 __init_single_page(page
, pfn
, zid
, nid
);
1533 if (!free_base_page
) {
1534 free_base_page
= page
;
1535 free_base_pfn
= pfn
;
1540 /* Where possible, batch up pages for a single free */
1543 /* Free the current block of pages to allocator */
1544 nr_pages
+= nr_to_free
;
1545 deferred_free_range(free_base_page
, free_base_pfn
,
1547 free_base_page
= NULL
;
1548 free_base_pfn
= nr_to_free
= 0;
1550 /* Free the last block of pages to allocator */
1551 nr_pages
+= nr_to_free
;
1552 deferred_free_range(free_base_page
, free_base_pfn
, nr_to_free
);
1554 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1557 /* Sanity check that the next zone really is unpopulated */
1558 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1560 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1561 jiffies_to_msecs(jiffies
- start
));
1563 pgdat_init_report_one_done();
1566 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1568 void __init
page_alloc_init_late(void)
1572 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1575 /* There will be num_node_state(N_MEMORY) threads */
1576 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1577 for_each_node_state(nid
, N_MEMORY
) {
1578 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1581 /* Block until all are initialised */
1582 wait_for_completion(&pgdat_init_all_done_comp
);
1584 /* Reinit limits that are based on free pages after the kernel is up */
1585 files_maxfiles_init();
1588 for_each_populated_zone(zone
)
1589 set_zone_contiguous(zone
);
1593 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1594 void __init
init_cma_reserved_pageblock(struct page
*page
)
1596 unsigned i
= pageblock_nr_pages
;
1597 struct page
*p
= page
;
1600 __ClearPageReserved(p
);
1601 set_page_count(p
, 0);
1604 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1606 if (pageblock_order
>= MAX_ORDER
) {
1607 i
= pageblock_nr_pages
;
1610 set_page_refcounted(p
);
1611 __free_pages(p
, MAX_ORDER
- 1);
1612 p
+= MAX_ORDER_NR_PAGES
;
1613 } while (i
-= MAX_ORDER_NR_PAGES
);
1615 set_page_refcounted(page
);
1616 __free_pages(page
, pageblock_order
);
1619 adjust_managed_page_count(page
, pageblock_nr_pages
);
1624 * The order of subdivision here is critical for the IO subsystem.
1625 * Please do not alter this order without good reasons and regression
1626 * testing. Specifically, as large blocks of memory are subdivided,
1627 * the order in which smaller blocks are delivered depends on the order
1628 * they're subdivided in this function. This is the primary factor
1629 * influencing the order in which pages are delivered to the IO
1630 * subsystem according to empirical testing, and this is also justified
1631 * by considering the behavior of a buddy system containing a single
1632 * large block of memory acted on by a series of small allocations.
1633 * This behavior is a critical factor in sglist merging's success.
1637 static inline void expand(struct zone
*zone
, struct page
*page
,
1638 int low
, int high
, struct free_area
*area
,
1641 unsigned long size
= 1 << high
;
1643 while (high
> low
) {
1647 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1650 * Mark as guard pages (or page), that will allow to
1651 * merge back to allocator when buddy will be freed.
1652 * Corresponding page table entries will not be touched,
1653 * pages will stay not present in virtual address space
1655 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1658 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1660 set_page_order(&page
[size
], high
);
1664 static void check_new_page_bad(struct page
*page
)
1666 const char *bad_reason
= NULL
;
1667 unsigned long bad_flags
= 0;
1669 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1670 bad_reason
= "nonzero mapcount";
1671 if (unlikely(page
->mapping
!= NULL
))
1672 bad_reason
= "non-NULL mapping";
1673 if (unlikely(page_ref_count(page
) != 0))
1674 bad_reason
= "nonzero _count";
1675 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1676 bad_reason
= "HWPoisoned (hardware-corrupted)";
1677 bad_flags
= __PG_HWPOISON
;
1678 /* Don't complain about hwpoisoned pages */
1679 page_mapcount_reset(page
); /* remove PageBuddy */
1682 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1683 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1684 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1687 if (unlikely(page
->mem_cgroup
))
1688 bad_reason
= "page still charged to cgroup";
1690 bad_page(page
, bad_reason
, bad_flags
);
1694 * This page is about to be returned from the page allocator
1696 static inline int check_new_page(struct page
*page
)
1698 if (likely(page_expected_state(page
,
1699 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1702 check_new_page_bad(page
);
1706 static inline bool free_pages_prezeroed(void)
1708 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1709 page_poisoning_enabled();
1712 #ifdef CONFIG_DEBUG_VM
1713 static bool check_pcp_refill(struct page
*page
)
1718 static bool check_new_pcp(struct page
*page
)
1720 return check_new_page(page
);
1723 static bool check_pcp_refill(struct page
*page
)
1725 return check_new_page(page
);
1727 static bool check_new_pcp(struct page
*page
)
1731 #endif /* CONFIG_DEBUG_VM */
1733 static bool check_new_pages(struct page
*page
, unsigned int order
)
1736 for (i
= 0; i
< (1 << order
); i
++) {
1737 struct page
*p
= page
+ i
;
1739 if (unlikely(check_new_page(p
)))
1746 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1749 set_page_private(page
, 0);
1750 set_page_refcounted(page
);
1752 arch_alloc_page(page
, order
);
1753 kernel_map_pages(page
, 1 << order
, 1);
1754 kernel_poison_pages(page
, 1 << order
, 1);
1755 kasan_alloc_pages(page
, order
);
1756 set_page_owner(page
, order
, gfp_flags
);
1759 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1760 unsigned int alloc_flags
)
1764 post_alloc_hook(page
, order
, gfp_flags
);
1766 if (!free_pages_prezeroed() && (gfp_flags
& __GFP_ZERO
))
1767 for (i
= 0; i
< (1 << order
); i
++)
1768 clear_highpage(page
+ i
);
1770 if (order
&& (gfp_flags
& __GFP_COMP
))
1771 prep_compound_page(page
, order
);
1774 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1775 * allocate the page. The expectation is that the caller is taking
1776 * steps that will free more memory. The caller should avoid the page
1777 * being used for !PFMEMALLOC purposes.
1779 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1780 set_page_pfmemalloc(page
);
1782 clear_page_pfmemalloc(page
);
1786 * Go through the free lists for the given migratetype and remove
1787 * the smallest available page from the freelists
1790 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1793 unsigned int current_order
;
1794 struct free_area
*area
;
1797 /* Find a page of the appropriate size in the preferred list */
1798 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1799 area
= &(zone
->free_area
[current_order
]);
1800 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1804 list_del(&page
->lru
);
1805 rmv_page_order(page
);
1807 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1808 set_pcppage_migratetype(page
, migratetype
);
1817 * This array describes the order lists are fallen back to when
1818 * the free lists for the desirable migrate type are depleted
1820 static int fallbacks
[MIGRATE_TYPES
][4] = {
1821 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1822 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1823 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1825 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1827 #ifdef CONFIG_MEMORY_ISOLATION
1828 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1833 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1836 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1839 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1840 unsigned int order
) { return NULL
; }
1844 * Move the free pages in a range to the free lists of the requested type.
1845 * Note that start_page and end_pages are not aligned on a pageblock
1846 * boundary. If alignment is required, use move_freepages_block()
1848 static int move_freepages(struct zone
*zone
,
1849 struct page
*start_page
, struct page
*end_page
,
1850 int migratetype
, int *num_movable
)
1854 int pages_moved
= 0;
1856 #ifndef CONFIG_HOLES_IN_ZONE
1858 * page_zone is not safe to call in this context when
1859 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1860 * anyway as we check zone boundaries in move_freepages_block().
1861 * Remove at a later date when no bug reports exist related to
1862 * grouping pages by mobility
1864 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1870 for (page
= start_page
; page
<= end_page
;) {
1871 if (!pfn_valid_within(page_to_pfn(page
))) {
1876 /* Make sure we are not inadvertently changing nodes */
1877 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1879 if (!PageBuddy(page
)) {
1881 * We assume that pages that could be isolated for
1882 * migration are movable. But we don't actually try
1883 * isolating, as that would be expensive.
1886 (PageLRU(page
) || __PageMovable(page
)))
1893 order
= page_order(page
);
1894 list_move(&page
->lru
,
1895 &zone
->free_area
[order
].free_list
[migratetype
]);
1897 pages_moved
+= 1 << order
;
1903 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1904 int migratetype
, int *num_movable
)
1906 unsigned long start_pfn
, end_pfn
;
1907 struct page
*start_page
, *end_page
;
1909 start_pfn
= page_to_pfn(page
);
1910 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1911 start_page
= pfn_to_page(start_pfn
);
1912 end_page
= start_page
+ pageblock_nr_pages
- 1;
1913 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1915 /* Do not cross zone boundaries */
1916 if (!zone_spans_pfn(zone
, start_pfn
))
1918 if (!zone_spans_pfn(zone
, end_pfn
))
1921 return move_freepages(zone
, start_page
, end_page
, migratetype
,
1925 static void change_pageblock_range(struct page
*pageblock_page
,
1926 int start_order
, int migratetype
)
1928 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1930 while (nr_pageblocks
--) {
1931 set_pageblock_migratetype(pageblock_page
, migratetype
);
1932 pageblock_page
+= pageblock_nr_pages
;
1937 * When we are falling back to another migratetype during allocation, try to
1938 * steal extra free pages from the same pageblocks to satisfy further
1939 * allocations, instead of polluting multiple pageblocks.
1941 * If we are stealing a relatively large buddy page, it is likely there will
1942 * be more free pages in the pageblock, so try to steal them all. For
1943 * reclaimable and unmovable allocations, we steal regardless of page size,
1944 * as fragmentation caused by those allocations polluting movable pageblocks
1945 * is worse than movable allocations stealing from unmovable and reclaimable
1948 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1951 * Leaving this order check is intended, although there is
1952 * relaxed order check in next check. The reason is that
1953 * we can actually steal whole pageblock if this condition met,
1954 * but, below check doesn't guarantee it and that is just heuristic
1955 * so could be changed anytime.
1957 if (order
>= pageblock_order
)
1960 if (order
>= pageblock_order
/ 2 ||
1961 start_mt
== MIGRATE_RECLAIMABLE
||
1962 start_mt
== MIGRATE_UNMOVABLE
||
1963 page_group_by_mobility_disabled
)
1970 * This function implements actual steal behaviour. If order is large enough,
1971 * we can steal whole pageblock. If not, we first move freepages in this
1972 * pageblock to our migratetype and determine how many already-allocated pages
1973 * are there in the pageblock with a compatible migratetype. If at least half
1974 * of pages are free or compatible, we can change migratetype of the pageblock
1975 * itself, so pages freed in the future will be put on the correct free list.
1977 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1978 int start_type
, bool whole_block
)
1980 unsigned int current_order
= page_order(page
);
1981 struct free_area
*area
;
1982 int free_pages
, movable_pages
, alike_pages
;
1985 old_block_type
= get_pageblock_migratetype(page
);
1988 * This can happen due to races and we want to prevent broken
1989 * highatomic accounting.
1991 if (is_migrate_highatomic(old_block_type
))
1994 /* Take ownership for orders >= pageblock_order */
1995 if (current_order
>= pageblock_order
) {
1996 change_pageblock_range(page
, current_order
, start_type
);
2000 /* We are not allowed to try stealing from the whole block */
2004 free_pages
= move_freepages_block(zone
, page
, start_type
,
2007 * Determine how many pages are compatible with our allocation.
2008 * For movable allocation, it's the number of movable pages which
2009 * we just obtained. For other types it's a bit more tricky.
2011 if (start_type
== MIGRATE_MOVABLE
) {
2012 alike_pages
= movable_pages
;
2015 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2016 * to MOVABLE pageblock, consider all non-movable pages as
2017 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2018 * vice versa, be conservative since we can't distinguish the
2019 * exact migratetype of non-movable pages.
2021 if (old_block_type
== MIGRATE_MOVABLE
)
2022 alike_pages
= pageblock_nr_pages
2023 - (free_pages
+ movable_pages
);
2028 /* moving whole block can fail due to zone boundary conditions */
2033 * If a sufficient number of pages in the block are either free or of
2034 * comparable migratability as our allocation, claim the whole block.
2036 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2037 page_group_by_mobility_disabled
)
2038 set_pageblock_migratetype(page
, start_type
);
2043 area
= &zone
->free_area
[current_order
];
2044 list_move(&page
->lru
, &area
->free_list
[start_type
]);
2048 * Check whether there is a suitable fallback freepage with requested order.
2049 * If only_stealable is true, this function returns fallback_mt only if
2050 * we can steal other freepages all together. This would help to reduce
2051 * fragmentation due to mixed migratetype pages in one pageblock.
2053 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2054 int migratetype
, bool only_stealable
, bool *can_steal
)
2059 if (area
->nr_free
== 0)
2064 fallback_mt
= fallbacks
[migratetype
][i
];
2065 if (fallback_mt
== MIGRATE_TYPES
)
2068 if (list_empty(&area
->free_list
[fallback_mt
]))
2071 if (can_steal_fallback(order
, migratetype
))
2074 if (!only_stealable
)
2085 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2086 * there are no empty page blocks that contain a page with a suitable order
2088 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2089 unsigned int alloc_order
)
2092 unsigned long max_managed
, flags
;
2095 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2096 * Check is race-prone but harmless.
2098 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2099 if (zone
->nr_reserved_highatomic
>= max_managed
)
2102 spin_lock_irqsave(&zone
->lock
, flags
);
2104 /* Recheck the nr_reserved_highatomic limit under the lock */
2105 if (zone
->nr_reserved_highatomic
>= max_managed
)
2109 mt
= get_pageblock_migratetype(page
);
2110 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2111 && !is_migrate_cma(mt
)) {
2112 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2113 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2114 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2118 spin_unlock_irqrestore(&zone
->lock
, flags
);
2122 * Used when an allocation is about to fail under memory pressure. This
2123 * potentially hurts the reliability of high-order allocations when under
2124 * intense memory pressure but failed atomic allocations should be easier
2125 * to recover from than an OOM.
2127 * If @force is true, try to unreserve a pageblock even though highatomic
2128 * pageblock is exhausted.
2130 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2133 struct zonelist
*zonelist
= ac
->zonelist
;
2134 unsigned long flags
;
2141 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2144 * Preserve at least one pageblock unless memory pressure
2147 if (!force
&& zone
->nr_reserved_highatomic
<=
2151 spin_lock_irqsave(&zone
->lock
, flags
);
2152 for (order
= 0; order
< MAX_ORDER
; order
++) {
2153 struct free_area
*area
= &(zone
->free_area
[order
]);
2155 page
= list_first_entry_or_null(
2156 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2162 * In page freeing path, migratetype change is racy so
2163 * we can counter several free pages in a pageblock
2164 * in this loop althoug we changed the pageblock type
2165 * from highatomic to ac->migratetype. So we should
2166 * adjust the count once.
2168 if (is_migrate_highatomic_page(page
)) {
2170 * It should never happen but changes to
2171 * locking could inadvertently allow a per-cpu
2172 * drain to add pages to MIGRATE_HIGHATOMIC
2173 * while unreserving so be safe and watch for
2176 zone
->nr_reserved_highatomic
-= min(
2178 zone
->nr_reserved_highatomic
);
2182 * Convert to ac->migratetype and avoid the normal
2183 * pageblock stealing heuristics. Minimally, the caller
2184 * is doing the work and needs the pages. More
2185 * importantly, if the block was always converted to
2186 * MIGRATE_UNMOVABLE or another type then the number
2187 * of pageblocks that cannot be completely freed
2190 set_pageblock_migratetype(page
, ac
->migratetype
);
2191 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2194 spin_unlock_irqrestore(&zone
->lock
, flags
);
2198 spin_unlock_irqrestore(&zone
->lock
, flags
);
2205 * Try finding a free buddy page on the fallback list and put it on the free
2206 * list of requested migratetype, possibly along with other pages from the same
2207 * block, depending on fragmentation avoidance heuristics. Returns true if
2208 * fallback was found so that __rmqueue_smallest() can grab it.
2211 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
2213 struct free_area
*area
;
2214 unsigned int current_order
;
2220 * Find the largest available free page in the other list. This roughly
2221 * approximates finding the pageblock with the most free pages, which
2222 * would be too costly to do exactly.
2224 for (current_order
= MAX_ORDER
-1;
2225 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
2227 area
= &(zone
->free_area
[current_order
]);
2228 fallback_mt
= find_suitable_fallback(area
, current_order
,
2229 start_migratetype
, false, &can_steal
);
2230 if (fallback_mt
== -1)
2234 * We cannot steal all free pages from the pageblock and the
2235 * requested migratetype is movable. In that case it's better to
2236 * steal and split the smallest available page instead of the
2237 * largest available page, because even if the next movable
2238 * allocation falls back into a different pageblock than this
2239 * one, it won't cause permanent fragmentation.
2241 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2242 && current_order
> order
)
2251 for (current_order
= order
; current_order
< MAX_ORDER
;
2253 area
= &(zone
->free_area
[current_order
]);
2254 fallback_mt
= find_suitable_fallback(area
, current_order
,
2255 start_migratetype
, false, &can_steal
);
2256 if (fallback_mt
!= -1)
2261 * This should not happen - we already found a suitable fallback
2262 * when looking for the largest page.
2264 VM_BUG_ON(current_order
== MAX_ORDER
);
2267 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2270 steal_suitable_fallback(zone
, page
, start_migratetype
, can_steal
);
2272 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2273 start_migratetype
, fallback_mt
);
2280 * Do the hard work of removing an element from the buddy allocator.
2281 * Call me with the zone->lock already held.
2283 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
2289 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2290 if (unlikely(!page
)) {
2291 if (migratetype
== MIGRATE_MOVABLE
)
2292 page
= __rmqueue_cma_fallback(zone
, order
);
2294 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
))
2298 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2303 * Obtain a specified number of elements from the buddy allocator, all under
2304 * a single hold of the lock, for efficiency. Add them to the supplied list.
2305 * Returns the number of new pages which were placed at *list.
2307 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2308 unsigned long count
, struct list_head
*list
,
2309 int migratetype
, bool cold
)
2313 spin_lock(&zone
->lock
);
2314 for (i
= 0; i
< count
; ++i
) {
2315 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2316 if (unlikely(page
== NULL
))
2319 if (unlikely(check_pcp_refill(page
)))
2323 * Split buddy pages returned by expand() are received here
2324 * in physical page order. The page is added to the callers and
2325 * list and the list head then moves forward. From the callers
2326 * perspective, the linked list is ordered by page number in
2327 * some conditions. This is useful for IO devices that can
2328 * merge IO requests if the physical pages are ordered
2332 list_add(&page
->lru
, list
);
2334 list_add_tail(&page
->lru
, list
);
2337 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2338 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2343 * i pages were removed from the buddy list even if some leak due
2344 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2345 * on i. Do not confuse with 'alloced' which is the number of
2346 * pages added to the pcp list.
2348 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2349 spin_unlock(&zone
->lock
);
2355 * Called from the vmstat counter updater to drain pagesets of this
2356 * currently executing processor on remote nodes after they have
2359 * Note that this function must be called with the thread pinned to
2360 * a single processor.
2362 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2364 unsigned long flags
;
2365 int to_drain
, batch
;
2367 local_irq_save(flags
);
2368 batch
= READ_ONCE(pcp
->batch
);
2369 to_drain
= min(pcp
->count
, batch
);
2371 free_pcppages_bulk(zone
, to_drain
, pcp
);
2372 pcp
->count
-= to_drain
;
2374 local_irq_restore(flags
);
2379 * Drain pcplists of the indicated processor and zone.
2381 * The processor must either be the current processor and the
2382 * thread pinned to the current processor or a processor that
2385 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2387 unsigned long flags
;
2388 struct per_cpu_pageset
*pset
;
2389 struct per_cpu_pages
*pcp
;
2391 local_irq_save(flags
);
2392 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2396 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2399 local_irq_restore(flags
);
2403 * Drain pcplists of all zones on the indicated processor.
2405 * The processor must either be the current processor and the
2406 * thread pinned to the current processor or a processor that
2409 static void drain_pages(unsigned int cpu
)
2413 for_each_populated_zone(zone
) {
2414 drain_pages_zone(cpu
, zone
);
2419 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2421 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2422 * the single zone's pages.
2424 void drain_local_pages(struct zone
*zone
)
2426 int cpu
= smp_processor_id();
2429 drain_pages_zone(cpu
, zone
);
2434 static void drain_local_pages_wq(struct work_struct
*work
)
2437 * drain_all_pages doesn't use proper cpu hotplug protection so
2438 * we can race with cpu offline when the WQ can move this from
2439 * a cpu pinned worker to an unbound one. We can operate on a different
2440 * cpu which is allright but we also have to make sure to not move to
2444 drain_local_pages(NULL
);
2449 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2451 * When zone parameter is non-NULL, spill just the single zone's pages.
2453 * Note that this can be extremely slow as the draining happens in a workqueue.
2455 void drain_all_pages(struct zone
*zone
)
2460 * Allocate in the BSS so we wont require allocation in
2461 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2463 static cpumask_t cpus_with_pcps
;
2466 * Make sure nobody triggers this path before mm_percpu_wq is fully
2469 if (WARN_ON_ONCE(!mm_percpu_wq
))
2472 /* Workqueues cannot recurse */
2473 if (current
->flags
& PF_WQ_WORKER
)
2477 * Do not drain if one is already in progress unless it's specific to
2478 * a zone. Such callers are primarily CMA and memory hotplug and need
2479 * the drain to be complete when the call returns.
2481 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2484 mutex_lock(&pcpu_drain_mutex
);
2488 * We don't care about racing with CPU hotplug event
2489 * as offline notification will cause the notified
2490 * cpu to drain that CPU pcps and on_each_cpu_mask
2491 * disables preemption as part of its processing
2493 for_each_online_cpu(cpu
) {
2494 struct per_cpu_pageset
*pcp
;
2496 bool has_pcps
= false;
2499 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2503 for_each_populated_zone(z
) {
2504 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2505 if (pcp
->pcp
.count
) {
2513 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2515 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2518 for_each_cpu(cpu
, &cpus_with_pcps
) {
2519 struct work_struct
*work
= per_cpu_ptr(&pcpu_drain
, cpu
);
2520 INIT_WORK(work
, drain_local_pages_wq
);
2521 queue_work_on(cpu
, mm_percpu_wq
, work
);
2523 for_each_cpu(cpu
, &cpus_with_pcps
)
2524 flush_work(per_cpu_ptr(&pcpu_drain
, cpu
));
2526 mutex_unlock(&pcpu_drain_mutex
);
2529 #ifdef CONFIG_HIBERNATION
2531 void mark_free_pages(struct zone
*zone
)
2533 unsigned long pfn
, max_zone_pfn
;
2534 unsigned long flags
;
2535 unsigned int order
, t
;
2538 if (zone_is_empty(zone
))
2541 spin_lock_irqsave(&zone
->lock
, flags
);
2543 max_zone_pfn
= zone_end_pfn(zone
);
2544 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2545 if (pfn_valid(pfn
)) {
2546 page
= pfn_to_page(pfn
);
2548 if (page_zone(page
) != zone
)
2551 if (!swsusp_page_is_forbidden(page
))
2552 swsusp_unset_page_free(page
);
2555 for_each_migratetype_order(order
, t
) {
2556 list_for_each_entry(page
,
2557 &zone
->free_area
[order
].free_list
[t
], lru
) {
2560 pfn
= page_to_pfn(page
);
2561 for (i
= 0; i
< (1UL << order
); i
++)
2562 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2565 spin_unlock_irqrestore(&zone
->lock
, flags
);
2567 #endif /* CONFIG_PM */
2570 * Free a 0-order page
2571 * cold == true ? free a cold page : free a hot page
2573 void free_hot_cold_page(struct page
*page
, bool cold
)
2575 struct zone
*zone
= page_zone(page
);
2576 struct per_cpu_pages
*pcp
;
2577 unsigned long flags
;
2578 unsigned long pfn
= page_to_pfn(page
);
2581 if (!free_pcp_prepare(page
))
2584 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2585 set_pcppage_migratetype(page
, migratetype
);
2586 local_irq_save(flags
);
2587 __count_vm_event(PGFREE
);
2590 * We only track unmovable, reclaimable and movable on pcp lists.
2591 * Free ISOLATE pages back to the allocator because they are being
2592 * offlined but treat HIGHATOMIC as movable pages so we can get those
2593 * areas back if necessary. Otherwise, we may have to free
2594 * excessively into the page allocator
2596 if (migratetype
>= MIGRATE_PCPTYPES
) {
2597 if (unlikely(is_migrate_isolate(migratetype
))) {
2598 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2601 migratetype
= MIGRATE_MOVABLE
;
2604 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2606 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2608 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2610 if (pcp
->count
>= pcp
->high
) {
2611 unsigned long batch
= READ_ONCE(pcp
->batch
);
2612 free_pcppages_bulk(zone
, batch
, pcp
);
2613 pcp
->count
-= batch
;
2617 local_irq_restore(flags
);
2621 * Free a list of 0-order pages
2623 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2625 struct page
*page
, *next
;
2627 list_for_each_entry_safe(page
, next
, list
, lru
) {
2628 trace_mm_page_free_batched(page
, cold
);
2629 free_hot_cold_page(page
, cold
);
2634 * split_page takes a non-compound higher-order page, and splits it into
2635 * n (1<<order) sub-pages: page[0..n]
2636 * Each sub-page must be freed individually.
2638 * Note: this is probably too low level an operation for use in drivers.
2639 * Please consult with lkml before using this in your driver.
2641 void split_page(struct page
*page
, unsigned int order
)
2645 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2646 VM_BUG_ON_PAGE(!page_count(page
), page
);
2648 #ifdef CONFIG_KMEMCHECK
2650 * Split shadow pages too, because free(page[0]) would
2651 * otherwise free the whole shadow.
2653 if (kmemcheck_page_is_tracked(page
))
2654 split_page(virt_to_page(page
[0].shadow
), order
);
2657 for (i
= 1; i
< (1 << order
); i
++)
2658 set_page_refcounted(page
+ i
);
2659 split_page_owner(page
, order
);
2661 EXPORT_SYMBOL_GPL(split_page
);
2663 int __isolate_free_page(struct page
*page
, unsigned int order
)
2665 unsigned long watermark
;
2669 BUG_ON(!PageBuddy(page
));
2671 zone
= page_zone(page
);
2672 mt
= get_pageblock_migratetype(page
);
2674 if (!is_migrate_isolate(mt
)) {
2676 * Obey watermarks as if the page was being allocated. We can
2677 * emulate a high-order watermark check with a raised order-0
2678 * watermark, because we already know our high-order page
2681 watermark
= min_wmark_pages(zone
) + (1UL << order
);
2682 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
2685 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2688 /* Remove page from free list */
2689 list_del(&page
->lru
);
2690 zone
->free_area
[order
].nr_free
--;
2691 rmv_page_order(page
);
2694 * Set the pageblock if the isolated page is at least half of a
2697 if (order
>= pageblock_order
- 1) {
2698 struct page
*endpage
= page
+ (1 << order
) - 1;
2699 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2700 int mt
= get_pageblock_migratetype(page
);
2701 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
2702 && !is_migrate_highatomic(mt
))
2703 set_pageblock_migratetype(page
,
2709 return 1UL << order
;
2713 * Update NUMA hit/miss statistics
2715 * Must be called with interrupts disabled.
2717 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
2720 enum zone_stat_item local_stat
= NUMA_LOCAL
;
2722 if (z
->node
!= numa_node_id())
2723 local_stat
= NUMA_OTHER
;
2725 if (z
->node
== preferred_zone
->node
)
2726 __inc_zone_state(z
, NUMA_HIT
);
2728 __inc_zone_state(z
, NUMA_MISS
);
2729 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
2731 __inc_zone_state(z
, local_stat
);
2735 /* Remove page from the per-cpu list, caller must protect the list */
2736 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
2737 bool cold
, struct per_cpu_pages
*pcp
,
2738 struct list_head
*list
)
2743 if (list_empty(list
)) {
2744 pcp
->count
+= rmqueue_bulk(zone
, 0,
2747 if (unlikely(list_empty(list
)))
2752 page
= list_last_entry(list
, struct page
, lru
);
2754 page
= list_first_entry(list
, struct page
, lru
);
2756 list_del(&page
->lru
);
2758 } while (check_new_pcp(page
));
2763 /* Lock and remove page from the per-cpu list */
2764 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
2765 struct zone
*zone
, unsigned int order
,
2766 gfp_t gfp_flags
, int migratetype
)
2768 struct per_cpu_pages
*pcp
;
2769 struct list_head
*list
;
2770 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2772 unsigned long flags
;
2774 local_irq_save(flags
);
2775 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2776 list
= &pcp
->lists
[migratetype
];
2777 page
= __rmqueue_pcplist(zone
, migratetype
, cold
, pcp
, list
);
2779 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2780 zone_statistics(preferred_zone
, zone
);
2782 local_irq_restore(flags
);
2787 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2790 struct page
*rmqueue(struct zone
*preferred_zone
,
2791 struct zone
*zone
, unsigned int order
,
2792 gfp_t gfp_flags
, unsigned int alloc_flags
,
2795 unsigned long flags
;
2798 if (likely(order
== 0)) {
2799 page
= rmqueue_pcplist(preferred_zone
, zone
, order
,
2800 gfp_flags
, migratetype
);
2805 * We most definitely don't want callers attempting to
2806 * allocate greater than order-1 page units with __GFP_NOFAIL.
2808 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2809 spin_lock_irqsave(&zone
->lock
, flags
);
2813 if (alloc_flags
& ALLOC_HARDER
) {
2814 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2816 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2819 page
= __rmqueue(zone
, order
, migratetype
);
2820 } while (page
&& check_new_pages(page
, order
));
2821 spin_unlock(&zone
->lock
);
2824 __mod_zone_freepage_state(zone
, -(1 << order
),
2825 get_pcppage_migratetype(page
));
2827 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2828 zone_statistics(preferred_zone
, zone
);
2829 local_irq_restore(flags
);
2832 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
2836 local_irq_restore(flags
);
2840 #ifdef CONFIG_FAIL_PAGE_ALLOC
2843 struct fault_attr attr
;
2845 bool ignore_gfp_highmem
;
2846 bool ignore_gfp_reclaim
;
2848 } fail_page_alloc
= {
2849 .attr
= FAULT_ATTR_INITIALIZER
,
2850 .ignore_gfp_reclaim
= true,
2851 .ignore_gfp_highmem
= true,
2855 static int __init
setup_fail_page_alloc(char *str
)
2857 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2859 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2861 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2863 if (order
< fail_page_alloc
.min_order
)
2865 if (gfp_mask
& __GFP_NOFAIL
)
2867 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2869 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2870 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2873 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2876 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2878 static int __init
fail_page_alloc_debugfs(void)
2880 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2883 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2884 &fail_page_alloc
.attr
);
2886 return PTR_ERR(dir
);
2888 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2889 &fail_page_alloc
.ignore_gfp_reclaim
))
2891 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2892 &fail_page_alloc
.ignore_gfp_highmem
))
2894 if (!debugfs_create_u32("min-order", mode
, dir
,
2895 &fail_page_alloc
.min_order
))
2900 debugfs_remove_recursive(dir
);
2905 late_initcall(fail_page_alloc_debugfs
);
2907 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2909 #else /* CONFIG_FAIL_PAGE_ALLOC */
2911 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2916 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2919 * Return true if free base pages are above 'mark'. For high-order checks it
2920 * will return true of the order-0 watermark is reached and there is at least
2921 * one free page of a suitable size. Checking now avoids taking the zone lock
2922 * to check in the allocation paths if no pages are free.
2924 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2925 int classzone_idx
, unsigned int alloc_flags
,
2930 const bool alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2932 /* free_pages may go negative - that's OK */
2933 free_pages
-= (1 << order
) - 1;
2935 if (alloc_flags
& ALLOC_HIGH
)
2939 * If the caller does not have rights to ALLOC_HARDER then subtract
2940 * the high-atomic reserves. This will over-estimate the size of the
2941 * atomic reserve but it avoids a search.
2943 if (likely(!alloc_harder
))
2944 free_pages
-= z
->nr_reserved_highatomic
;
2949 /* If allocation can't use CMA areas don't use free CMA pages */
2950 if (!(alloc_flags
& ALLOC_CMA
))
2951 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2955 * Check watermarks for an order-0 allocation request. If these
2956 * are not met, then a high-order request also cannot go ahead
2957 * even if a suitable page happened to be free.
2959 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2962 /* If this is an order-0 request then the watermark is fine */
2966 /* For a high-order request, check at least one suitable page is free */
2967 for (o
= order
; o
< MAX_ORDER
; o
++) {
2968 struct free_area
*area
= &z
->free_area
[o
];
2977 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2978 if (!list_empty(&area
->free_list
[mt
]))
2983 if ((alloc_flags
& ALLOC_CMA
) &&
2984 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2992 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2993 int classzone_idx
, unsigned int alloc_flags
)
2995 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2996 zone_page_state(z
, NR_FREE_PAGES
));
2999 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3000 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
3002 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3006 /* If allocation can't use CMA areas don't use free CMA pages */
3007 if (!(alloc_flags
& ALLOC_CMA
))
3008 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3012 * Fast check for order-0 only. If this fails then the reserves
3013 * need to be calculated. There is a corner case where the check
3014 * passes but only the high-order atomic reserve are free. If
3015 * the caller is !atomic then it'll uselessly search the free
3016 * list. That corner case is then slower but it is harmless.
3018 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
3021 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3025 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3026 unsigned long mark
, int classzone_idx
)
3028 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3030 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3031 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3033 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
3038 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3040 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3043 #else /* CONFIG_NUMA */
3044 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3048 #endif /* CONFIG_NUMA */
3051 * get_page_from_freelist goes through the zonelist trying to allocate
3054 static struct page
*
3055 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3056 const struct alloc_context
*ac
)
3058 struct zoneref
*z
= ac
->preferred_zoneref
;
3060 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3063 * Scan zonelist, looking for a zone with enough free.
3064 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3066 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3071 if (cpusets_enabled() &&
3072 (alloc_flags
& ALLOC_CPUSET
) &&
3073 !__cpuset_zone_allowed(zone
, gfp_mask
))
3076 * When allocating a page cache page for writing, we
3077 * want to get it from a node that is within its dirty
3078 * limit, such that no single node holds more than its
3079 * proportional share of globally allowed dirty pages.
3080 * The dirty limits take into account the node's
3081 * lowmem reserves and high watermark so that kswapd
3082 * should be able to balance it without having to
3083 * write pages from its LRU list.
3085 * XXX: For now, allow allocations to potentially
3086 * exceed the per-node dirty limit in the slowpath
3087 * (spread_dirty_pages unset) before going into reclaim,
3088 * which is important when on a NUMA setup the allowed
3089 * nodes are together not big enough to reach the
3090 * global limit. The proper fix for these situations
3091 * will require awareness of nodes in the
3092 * dirty-throttling and the flusher threads.
3094 if (ac
->spread_dirty_pages
) {
3095 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3098 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3099 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3104 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
3105 if (!zone_watermark_fast(zone
, order
, mark
,
3106 ac_classzone_idx(ac
), alloc_flags
)) {
3109 /* Checked here to keep the fast path fast */
3110 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3111 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3114 if (node_reclaim_mode
== 0 ||
3115 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3118 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3120 case NODE_RECLAIM_NOSCAN
:
3123 case NODE_RECLAIM_FULL
:
3124 /* scanned but unreclaimable */
3127 /* did we reclaim enough */
3128 if (zone_watermark_ok(zone
, order
, mark
,
3129 ac_classzone_idx(ac
), alloc_flags
))
3137 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3138 gfp_mask
, alloc_flags
, ac
->migratetype
);
3140 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3143 * If this is a high-order atomic allocation then check
3144 * if the pageblock should be reserved for the future
3146 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3147 reserve_highatomic_pageblock(page
, zone
, order
);
3157 * Large machines with many possible nodes should not always dump per-node
3158 * meminfo in irq context.
3160 static inline bool should_suppress_show_mem(void)
3165 ret
= in_interrupt();
3170 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3172 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3173 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3175 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs
))
3179 * This documents exceptions given to allocations in certain
3180 * contexts that are allowed to allocate outside current's set
3183 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3184 if (test_thread_flag(TIF_MEMDIE
) ||
3185 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3186 filter
&= ~SHOW_MEM_FILTER_NODES
;
3187 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3188 filter
&= ~SHOW_MEM_FILTER_NODES
;
3190 show_mem(filter
, nodemask
);
3193 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3195 struct va_format vaf
;
3197 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3198 DEFAULT_RATELIMIT_BURST
);
3200 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3203 pr_warn("%s: ", current
->comm
);
3205 va_start(args
, fmt
);
3208 pr_cont("%pV", &vaf
);
3211 pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask
, &gfp_mask
);
3213 pr_cont("%*pbl\n", nodemask_pr_args(nodemask
));
3215 pr_cont("(null)\n");
3217 cpuset_print_current_mems_allowed();
3220 warn_alloc_show_mem(gfp_mask
, nodemask
);
3223 static inline struct page
*
3224 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3225 unsigned int alloc_flags
,
3226 const struct alloc_context
*ac
)
3230 page
= get_page_from_freelist(gfp_mask
, order
,
3231 alloc_flags
|ALLOC_CPUSET
, ac
);
3233 * fallback to ignore cpuset restriction if our nodes
3237 page
= get_page_from_freelist(gfp_mask
, order
,
3243 static inline struct page
*
3244 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3245 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3247 struct oom_control oc
= {
3248 .zonelist
= ac
->zonelist
,
3249 .nodemask
= ac
->nodemask
,
3251 .gfp_mask
= gfp_mask
,
3256 *did_some_progress
= 0;
3259 * Acquire the oom lock. If that fails, somebody else is
3260 * making progress for us.
3262 if (!mutex_trylock(&oom_lock
)) {
3263 *did_some_progress
= 1;
3264 schedule_timeout_uninterruptible(1);
3269 * Go through the zonelist yet one more time, keep very high watermark
3270 * here, this is only to catch a parallel oom killing, we must fail if
3271 * we're still under heavy pressure.
3273 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
3274 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3278 /* Coredumps can quickly deplete all memory reserves */
3279 if (current
->flags
& PF_DUMPCORE
)
3281 /* The OOM killer will not help higher order allocs */
3282 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3284 /* The OOM killer does not needlessly kill tasks for lowmem */
3285 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3287 if (pm_suspended_storage())
3290 * XXX: GFP_NOFS allocations should rather fail than rely on
3291 * other request to make a forward progress.
3292 * We are in an unfortunate situation where out_of_memory cannot
3293 * do much for this context but let's try it to at least get
3294 * access to memory reserved if the current task is killed (see
3295 * out_of_memory). Once filesystems are ready to handle allocation
3296 * failures more gracefully we should just bail out here.
3299 /* The OOM killer may not free memory on a specific node */
3300 if (gfp_mask
& __GFP_THISNODE
)
3303 /* Exhausted what can be done so it's blamo time */
3304 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3305 *did_some_progress
= 1;
3308 * Help non-failing allocations by giving them access to memory
3311 if (gfp_mask
& __GFP_NOFAIL
)
3312 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3313 ALLOC_NO_WATERMARKS
, ac
);
3316 mutex_unlock(&oom_lock
);
3321 * Maximum number of compaction retries wit a progress before OOM
3322 * killer is consider as the only way to move forward.
3324 #define MAX_COMPACT_RETRIES 16
3326 #ifdef CONFIG_COMPACTION
3327 /* Try memory compaction for high-order allocations before reclaim */
3328 static struct page
*
3329 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3330 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3331 enum compact_priority prio
, enum compact_result
*compact_result
)
3334 unsigned int noreclaim_flag
;
3339 noreclaim_flag
= memalloc_noreclaim_save();
3340 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3342 memalloc_noreclaim_restore(noreclaim_flag
);
3344 if (*compact_result
<= COMPACT_INACTIVE
)
3348 * At least in one zone compaction wasn't deferred or skipped, so let's
3349 * count a compaction stall
3351 count_vm_event(COMPACTSTALL
);
3353 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3356 struct zone
*zone
= page_zone(page
);
3358 zone
->compact_blockskip_flush
= false;
3359 compaction_defer_reset(zone
, order
, true);
3360 count_vm_event(COMPACTSUCCESS
);
3365 * It's bad if compaction run occurs and fails. The most likely reason
3366 * is that pages exist, but not enough to satisfy watermarks.
3368 count_vm_event(COMPACTFAIL
);
3376 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3377 enum compact_result compact_result
,
3378 enum compact_priority
*compact_priority
,
3379 int *compaction_retries
)
3381 int max_retries
= MAX_COMPACT_RETRIES
;
3384 int retries
= *compaction_retries
;
3385 enum compact_priority priority
= *compact_priority
;
3390 if (compaction_made_progress(compact_result
))
3391 (*compaction_retries
)++;
3394 * compaction considers all the zone as desperately out of memory
3395 * so it doesn't really make much sense to retry except when the
3396 * failure could be caused by insufficient priority
3398 if (compaction_failed(compact_result
))
3399 goto check_priority
;
3402 * make sure the compaction wasn't deferred or didn't bail out early
3403 * due to locks contention before we declare that we should give up.
3404 * But do not retry if the given zonelist is not suitable for
3407 if (compaction_withdrawn(compact_result
)) {
3408 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3413 * !costly requests are much more important than __GFP_REPEAT
3414 * costly ones because they are de facto nofail and invoke OOM
3415 * killer to move on while costly can fail and users are ready
3416 * to cope with that. 1/4 retries is rather arbitrary but we
3417 * would need much more detailed feedback from compaction to
3418 * make a better decision.
3420 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3422 if (*compaction_retries
<= max_retries
) {
3428 * Make sure there are attempts at the highest priority if we exhausted
3429 * all retries or failed at the lower priorities.
3432 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3433 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3435 if (*compact_priority
> min_priority
) {
3436 (*compact_priority
)--;
3437 *compaction_retries
= 0;
3441 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3445 static inline struct page
*
3446 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3447 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3448 enum compact_priority prio
, enum compact_result
*compact_result
)
3450 *compact_result
= COMPACT_SKIPPED
;
3455 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3456 enum compact_result compact_result
,
3457 enum compact_priority
*compact_priority
,
3458 int *compaction_retries
)
3463 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3467 * There are setups with compaction disabled which would prefer to loop
3468 * inside the allocator rather than hit the oom killer prematurely.
3469 * Let's give them a good hope and keep retrying while the order-0
3470 * watermarks are OK.
3472 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3474 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3475 ac_classzone_idx(ac
), alloc_flags
))
3480 #endif /* CONFIG_COMPACTION */
3482 /* Perform direct synchronous page reclaim */
3484 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3485 const struct alloc_context
*ac
)
3487 struct reclaim_state reclaim_state
;
3489 unsigned int noreclaim_flag
;
3493 /* We now go into synchronous reclaim */
3494 cpuset_memory_pressure_bump();
3495 noreclaim_flag
= memalloc_noreclaim_save();
3496 lockdep_set_current_reclaim_state(gfp_mask
);
3497 reclaim_state
.reclaimed_slab
= 0;
3498 current
->reclaim_state
= &reclaim_state
;
3500 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3503 current
->reclaim_state
= NULL
;
3504 lockdep_clear_current_reclaim_state();
3505 memalloc_noreclaim_restore(noreclaim_flag
);
3512 /* The really slow allocator path where we enter direct reclaim */
3513 static inline struct page
*
3514 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3515 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3516 unsigned long *did_some_progress
)
3518 struct page
*page
= NULL
;
3519 bool drained
= false;
3521 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3522 if (unlikely(!(*did_some_progress
)))
3526 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3529 * If an allocation failed after direct reclaim, it could be because
3530 * pages are pinned on the per-cpu lists or in high alloc reserves.
3531 * Shrink them them and try again
3533 if (!page
&& !drained
) {
3534 unreserve_highatomic_pageblock(ac
, false);
3535 drain_all_pages(NULL
);
3543 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3547 pg_data_t
*last_pgdat
= NULL
;
3549 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3550 ac
->high_zoneidx
, ac
->nodemask
) {
3551 if (last_pgdat
!= zone
->zone_pgdat
)
3552 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3553 last_pgdat
= zone
->zone_pgdat
;
3557 static inline unsigned int
3558 gfp_to_alloc_flags(gfp_t gfp_mask
)
3560 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3562 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3563 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3566 * The caller may dip into page reserves a bit more if the caller
3567 * cannot run direct reclaim, or if the caller has realtime scheduling
3568 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3569 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3571 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3573 if (gfp_mask
& __GFP_ATOMIC
) {
3575 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3576 * if it can't schedule.
3578 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3579 alloc_flags
|= ALLOC_HARDER
;
3581 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3582 * comment for __cpuset_node_allowed().
3584 alloc_flags
&= ~ALLOC_CPUSET
;
3585 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3586 alloc_flags
|= ALLOC_HARDER
;
3589 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3590 alloc_flags
|= ALLOC_CMA
;
3595 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3597 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3600 if (gfp_mask
& __GFP_MEMALLOC
)
3602 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3604 if (!in_interrupt() &&
3605 ((current
->flags
& PF_MEMALLOC
) ||
3606 unlikely(test_thread_flag(TIF_MEMDIE
))))
3613 * Checks whether it makes sense to retry the reclaim to make a forward progress
3614 * for the given allocation request.
3616 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3617 * without success, or when we couldn't even meet the watermark if we
3618 * reclaimed all remaining pages on the LRU lists.
3620 * Returns true if a retry is viable or false to enter the oom path.
3623 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3624 struct alloc_context
*ac
, int alloc_flags
,
3625 bool did_some_progress
, int *no_progress_loops
)
3631 * Costly allocations might have made a progress but this doesn't mean
3632 * their order will become available due to high fragmentation so
3633 * always increment the no progress counter for them
3635 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3636 *no_progress_loops
= 0;
3638 (*no_progress_loops
)++;
3641 * Make sure we converge to OOM if we cannot make any progress
3642 * several times in the row.
3644 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
3645 /* Before OOM, exhaust highatomic_reserve */
3646 return unreserve_highatomic_pageblock(ac
, true);
3650 * Keep reclaiming pages while there is a chance this will lead
3651 * somewhere. If none of the target zones can satisfy our allocation
3652 * request even if all reclaimable pages are considered then we are
3653 * screwed and have to go OOM.
3655 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3657 unsigned long available
;
3658 unsigned long reclaimable
;
3659 unsigned long min_wmark
= min_wmark_pages(zone
);
3662 available
= reclaimable
= zone_reclaimable_pages(zone
);
3663 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3666 * Would the allocation succeed if we reclaimed all
3667 * reclaimable pages?
3669 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
3670 ac_classzone_idx(ac
), alloc_flags
, available
);
3671 trace_reclaim_retry_zone(z
, order
, reclaimable
,
3672 available
, min_wmark
, *no_progress_loops
, wmark
);
3675 * If we didn't make any progress and have a lot of
3676 * dirty + writeback pages then we should wait for
3677 * an IO to complete to slow down the reclaim and
3678 * prevent from pre mature OOM
3680 if (!did_some_progress
) {
3681 unsigned long write_pending
;
3683 write_pending
= zone_page_state_snapshot(zone
,
3684 NR_ZONE_WRITE_PENDING
);
3686 if (2 * write_pending
> reclaimable
) {
3687 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3693 * Memory allocation/reclaim might be called from a WQ
3694 * context and the current implementation of the WQ
3695 * concurrency control doesn't recognize that
3696 * a particular WQ is congested if the worker thread is
3697 * looping without ever sleeping. Therefore we have to
3698 * do a short sleep here rather than calling
3701 if (current
->flags
& PF_WQ_WORKER
)
3702 schedule_timeout_uninterruptible(1);
3714 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
3717 * It's possible that cpuset's mems_allowed and the nodemask from
3718 * mempolicy don't intersect. This should be normally dealt with by
3719 * policy_nodemask(), but it's possible to race with cpuset update in
3720 * such a way the check therein was true, and then it became false
3721 * before we got our cpuset_mems_cookie here.
3722 * This assumes that for all allocations, ac->nodemask can come only
3723 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
3724 * when it does not intersect with the cpuset restrictions) or the
3725 * caller can deal with a violated nodemask.
3727 if (cpusets_enabled() && ac
->nodemask
&&
3728 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
3729 ac
->nodemask
= NULL
;
3734 * When updating a task's mems_allowed or mempolicy nodemask, it is
3735 * possible to race with parallel threads in such a way that our
3736 * allocation can fail while the mask is being updated. If we are about
3737 * to fail, check if the cpuset changed during allocation and if so,
3740 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3746 static inline struct page
*
3747 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3748 struct alloc_context
*ac
)
3750 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3751 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
3752 struct page
*page
= NULL
;
3753 unsigned int alloc_flags
;
3754 unsigned long did_some_progress
;
3755 enum compact_priority compact_priority
;
3756 enum compact_result compact_result
;
3757 int compaction_retries
;
3758 int no_progress_loops
;
3759 unsigned long alloc_start
= jiffies
;
3760 unsigned int stall_timeout
= 10 * HZ
;
3761 unsigned int cpuset_mems_cookie
;
3764 * In the slowpath, we sanity check order to avoid ever trying to
3765 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3766 * be using allocators in order of preference for an area that is
3769 if (order
>= MAX_ORDER
) {
3770 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3775 * We also sanity check to catch abuse of atomic reserves being used by
3776 * callers that are not in atomic context.
3778 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3779 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3780 gfp_mask
&= ~__GFP_ATOMIC
;
3783 compaction_retries
= 0;
3784 no_progress_loops
= 0;
3785 compact_priority
= DEF_COMPACT_PRIORITY
;
3786 cpuset_mems_cookie
= read_mems_allowed_begin();
3789 * The fast path uses conservative alloc_flags to succeed only until
3790 * kswapd needs to be woken up, and to avoid the cost of setting up
3791 * alloc_flags precisely. So we do that now.
3793 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3796 * We need to recalculate the starting point for the zonelist iterator
3797 * because we might have used different nodemask in the fast path, or
3798 * there was a cpuset modification and we are retrying - otherwise we
3799 * could end up iterating over non-eligible zones endlessly.
3801 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3802 ac
->high_zoneidx
, ac
->nodemask
);
3803 if (!ac
->preferred_zoneref
->zone
)
3806 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3807 wake_all_kswapds(order
, ac
);
3810 * The adjusted alloc_flags might result in immediate success, so try
3813 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3818 * For costly allocations, try direct compaction first, as it's likely
3819 * that we have enough base pages and don't need to reclaim. For non-
3820 * movable high-order allocations, do that as well, as compaction will
3821 * try prevent permanent fragmentation by migrating from blocks of the
3823 * Don't try this for allocations that are allowed to ignore
3824 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
3826 if (can_direct_reclaim
&&
3828 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
3829 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
3830 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
3832 INIT_COMPACT_PRIORITY
,
3838 * Checks for costly allocations with __GFP_NORETRY, which
3839 * includes THP page fault allocations
3841 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
3843 * If compaction is deferred for high-order allocations,
3844 * it is because sync compaction recently failed. If
3845 * this is the case and the caller requested a THP
3846 * allocation, we do not want to heavily disrupt the
3847 * system, so we fail the allocation instead of entering
3850 if (compact_result
== COMPACT_DEFERRED
)
3854 * Looks like reclaim/compaction is worth trying, but
3855 * sync compaction could be very expensive, so keep
3856 * using async compaction.
3858 compact_priority
= INIT_COMPACT_PRIORITY
;
3863 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
3864 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3865 wake_all_kswapds(order
, ac
);
3867 if (gfp_pfmemalloc_allowed(gfp_mask
))
3868 alloc_flags
= ALLOC_NO_WATERMARKS
;
3871 * Reset the zonelist iterators if memory policies can be ignored.
3872 * These allocations are high priority and system rather than user
3875 if (!(alloc_flags
& ALLOC_CPUSET
) || (alloc_flags
& ALLOC_NO_WATERMARKS
)) {
3876 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3877 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3878 ac
->high_zoneidx
, ac
->nodemask
);
3881 /* Attempt with potentially adjusted zonelist and alloc_flags */
3882 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3886 /* Caller is not willing to reclaim, we can't balance anything */
3887 if (!can_direct_reclaim
)
3890 /* Make sure we know about allocations which stall for too long */
3891 if (time_after(jiffies
, alloc_start
+ stall_timeout
)) {
3892 warn_alloc(gfp_mask
& ~__GFP_NOWARN
, ac
->nodemask
,
3893 "page allocation stalls for %ums, order:%u",
3894 jiffies_to_msecs(jiffies
-alloc_start
), order
);
3895 stall_timeout
+= 10 * HZ
;
3898 /* Avoid recursion of direct reclaim */
3899 if (current
->flags
& PF_MEMALLOC
)
3902 /* Try direct reclaim and then allocating */
3903 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3904 &did_some_progress
);
3908 /* Try direct compaction and then allocating */
3909 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3910 compact_priority
, &compact_result
);
3914 /* Do not loop if specifically requested */
3915 if (gfp_mask
& __GFP_NORETRY
)
3919 * Do not retry costly high order allocations unless they are
3922 if (costly_order
&& !(gfp_mask
& __GFP_REPEAT
))
3925 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
3926 did_some_progress
> 0, &no_progress_loops
))
3930 * It doesn't make any sense to retry for the compaction if the order-0
3931 * reclaim is not able to make any progress because the current
3932 * implementation of the compaction depends on the sufficient amount
3933 * of free memory (see __compaction_suitable)
3935 if (did_some_progress
> 0 &&
3936 should_compact_retry(ac
, order
, alloc_flags
,
3937 compact_result
, &compact_priority
,
3938 &compaction_retries
))
3942 /* Deal with possible cpuset update races before we start OOM killing */
3943 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
3946 /* Reclaim has failed us, start killing things */
3947 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3951 /* Avoid allocations with no watermarks from looping endlessly */
3952 if (test_thread_flag(TIF_MEMDIE
) &&
3953 (alloc_flags
== ALLOC_NO_WATERMARKS
||
3954 (gfp_mask
& __GFP_NOMEMALLOC
)))
3957 /* Retry as long as the OOM killer is making progress */
3958 if (did_some_progress
) {
3959 no_progress_loops
= 0;
3964 /* Deal with possible cpuset update races before we fail */
3965 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
3969 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
3972 if (gfp_mask
& __GFP_NOFAIL
) {
3974 * All existing users of the __GFP_NOFAIL are blockable, so warn
3975 * of any new users that actually require GFP_NOWAIT
3977 if (WARN_ON_ONCE(!can_direct_reclaim
))
3981 * PF_MEMALLOC request from this context is rather bizarre
3982 * because we cannot reclaim anything and only can loop waiting
3983 * for somebody to do a work for us
3985 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
3988 * non failing costly orders are a hard requirement which we
3989 * are not prepared for much so let's warn about these users
3990 * so that we can identify them and convert them to something
3993 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
3996 * Help non-failing allocations by giving them access to memory
3997 * reserves but do not use ALLOC_NO_WATERMARKS because this
3998 * could deplete whole memory reserves which would just make
3999 * the situation worse
4001 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4009 warn_alloc(gfp_mask
, ac
->nodemask
,
4010 "page allocation failure: order:%u", order
);
4015 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4016 int preferred_nid
, nodemask_t
*nodemask
,
4017 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4018 unsigned int *alloc_flags
)
4020 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
4021 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4022 ac
->nodemask
= nodemask
;
4023 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
4025 if (cpusets_enabled()) {
4026 *alloc_mask
|= __GFP_HARDWALL
;
4028 ac
->nodemask
= &cpuset_current_mems_allowed
;
4030 *alloc_flags
|= ALLOC_CPUSET
;
4033 lockdep_trace_alloc(gfp_mask
);
4035 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4037 if (should_fail_alloc_page(gfp_mask
, order
))
4040 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
4041 *alloc_flags
|= ALLOC_CMA
;
4046 /* Determine whether to spread dirty pages and what the first usable zone */
4047 static inline void finalise_ac(gfp_t gfp_mask
,
4048 unsigned int order
, struct alloc_context
*ac
)
4050 /* Dirty zone balancing only done in the fast path */
4051 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4054 * The preferred zone is used for statistics but crucially it is
4055 * also used as the starting point for the zonelist iterator. It
4056 * may get reset for allocations that ignore memory policies.
4058 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4059 ac
->high_zoneidx
, ac
->nodemask
);
4063 * This is the 'heart' of the zoned buddy allocator.
4066 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4067 nodemask_t
*nodemask
)
4070 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4071 gfp_t alloc_mask
= gfp_mask
; /* The gfp_t that was actually used for allocation */
4072 struct alloc_context ac
= { };
4074 gfp_mask
&= gfp_allowed_mask
;
4075 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4078 finalise_ac(gfp_mask
, order
, &ac
);
4080 /* First allocation attempt */
4081 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4086 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4087 * resp. GFP_NOIO which has to be inherited for all allocation requests
4088 * from a particular context which has been marked by
4089 * memalloc_no{fs,io}_{save,restore}.
4091 alloc_mask
= current_gfp_context(gfp_mask
);
4092 ac
.spread_dirty_pages
= false;
4095 * Restore the original nodemask if it was potentially replaced with
4096 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4098 if (unlikely(ac
.nodemask
!= nodemask
))
4099 ac
.nodemask
= nodemask
;
4101 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4104 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4105 unlikely(memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
4106 __free_pages(page
, order
);
4110 if (kmemcheck_enabled
&& page
)
4111 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
4113 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4117 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4120 * Common helper functions.
4122 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4127 * __get_free_pages() returns a 32-bit address, which cannot represent
4130 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
4132 page
= alloc_pages(gfp_mask
, order
);
4135 return (unsigned long) page_address(page
);
4137 EXPORT_SYMBOL(__get_free_pages
);
4139 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4141 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4143 EXPORT_SYMBOL(get_zeroed_page
);
4145 void __free_pages(struct page
*page
, unsigned int order
)
4147 if (put_page_testzero(page
)) {
4149 free_hot_cold_page(page
, false);
4151 __free_pages_ok(page
, order
);
4155 EXPORT_SYMBOL(__free_pages
);
4157 void free_pages(unsigned long addr
, unsigned int order
)
4160 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4161 __free_pages(virt_to_page((void *)addr
), order
);
4165 EXPORT_SYMBOL(free_pages
);
4169 * An arbitrary-length arbitrary-offset area of memory which resides
4170 * within a 0 or higher order page. Multiple fragments within that page
4171 * are individually refcounted, in the page's reference counter.
4173 * The page_frag functions below provide a simple allocation framework for
4174 * page fragments. This is used by the network stack and network device
4175 * drivers to provide a backing region of memory for use as either an
4176 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4178 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4181 struct page
*page
= NULL
;
4182 gfp_t gfp
= gfp_mask
;
4184 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4185 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4187 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4188 PAGE_FRAG_CACHE_MAX_ORDER
);
4189 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4191 if (unlikely(!page
))
4192 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4194 nc
->va
= page
? page_address(page
) : NULL
;
4199 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4201 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4203 if (page_ref_sub_and_test(page
, count
)) {
4204 unsigned int order
= compound_order(page
);
4207 free_hot_cold_page(page
, false);
4209 __free_pages_ok(page
, order
);
4212 EXPORT_SYMBOL(__page_frag_cache_drain
);
4214 void *page_frag_alloc(struct page_frag_cache
*nc
,
4215 unsigned int fragsz
, gfp_t gfp_mask
)
4217 unsigned int size
= PAGE_SIZE
;
4221 if (unlikely(!nc
->va
)) {
4223 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4227 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4228 /* if size can vary use size else just use PAGE_SIZE */
4231 /* Even if we own the page, we do not use atomic_set().
4232 * This would break get_page_unless_zero() users.
4234 page_ref_add(page
, size
- 1);
4236 /* reset page count bias and offset to start of new frag */
4237 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4238 nc
->pagecnt_bias
= size
;
4242 offset
= nc
->offset
- fragsz
;
4243 if (unlikely(offset
< 0)) {
4244 page
= virt_to_page(nc
->va
);
4246 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4249 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4250 /* if size can vary use size else just use PAGE_SIZE */
4253 /* OK, page count is 0, we can safely set it */
4254 set_page_count(page
, size
);
4256 /* reset page count bias and offset to start of new frag */
4257 nc
->pagecnt_bias
= size
;
4258 offset
= size
- fragsz
;
4262 nc
->offset
= offset
;
4264 return nc
->va
+ offset
;
4266 EXPORT_SYMBOL(page_frag_alloc
);
4269 * Frees a page fragment allocated out of either a compound or order 0 page.
4271 void page_frag_free(void *addr
)
4273 struct page
*page
= virt_to_head_page(addr
);
4275 if (unlikely(put_page_testzero(page
)))
4276 __free_pages_ok(page
, compound_order(page
));
4278 EXPORT_SYMBOL(page_frag_free
);
4280 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4284 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4285 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4287 split_page(virt_to_page((void *)addr
), order
);
4288 while (used
< alloc_end
) {
4293 return (void *)addr
;
4297 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4298 * @size: the number of bytes to allocate
4299 * @gfp_mask: GFP flags for the allocation
4301 * This function is similar to alloc_pages(), except that it allocates the
4302 * minimum number of pages to satisfy the request. alloc_pages() can only
4303 * allocate memory in power-of-two pages.
4305 * This function is also limited by MAX_ORDER.
4307 * Memory allocated by this function must be released by free_pages_exact().
4309 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4311 unsigned int order
= get_order(size
);
4314 addr
= __get_free_pages(gfp_mask
, order
);
4315 return make_alloc_exact(addr
, order
, size
);
4317 EXPORT_SYMBOL(alloc_pages_exact
);
4320 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4322 * @nid: the preferred node ID where memory should be allocated
4323 * @size: the number of bytes to allocate
4324 * @gfp_mask: GFP flags for the allocation
4326 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4329 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4331 unsigned int order
= get_order(size
);
4332 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4335 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4339 * free_pages_exact - release memory allocated via alloc_pages_exact()
4340 * @virt: the value returned by alloc_pages_exact.
4341 * @size: size of allocation, same value as passed to alloc_pages_exact().
4343 * Release the memory allocated by a previous call to alloc_pages_exact.
4345 void free_pages_exact(void *virt
, size_t size
)
4347 unsigned long addr
= (unsigned long)virt
;
4348 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4350 while (addr
< end
) {
4355 EXPORT_SYMBOL(free_pages_exact
);
4358 * nr_free_zone_pages - count number of pages beyond high watermark
4359 * @offset: The zone index of the highest zone
4361 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4362 * high watermark within all zones at or below a given zone index. For each
4363 * zone, the number of pages is calculated as:
4365 * nr_free_zone_pages = managed_pages - high_pages
4367 static unsigned long nr_free_zone_pages(int offset
)
4372 /* Just pick one node, since fallback list is circular */
4373 unsigned long sum
= 0;
4375 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4377 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4378 unsigned long size
= zone
->managed_pages
;
4379 unsigned long high
= high_wmark_pages(zone
);
4388 * nr_free_buffer_pages - count number of pages beyond high watermark
4390 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4391 * watermark within ZONE_DMA and ZONE_NORMAL.
4393 unsigned long nr_free_buffer_pages(void)
4395 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4397 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4400 * nr_free_pagecache_pages - count number of pages beyond high watermark
4402 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4403 * high watermark within all zones.
4405 unsigned long nr_free_pagecache_pages(void)
4407 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4410 static inline void show_node(struct zone
*zone
)
4412 if (IS_ENABLED(CONFIG_NUMA
))
4413 printk("Node %d ", zone_to_nid(zone
));
4416 long si_mem_available(void)
4419 unsigned long pagecache
;
4420 unsigned long wmark_low
= 0;
4421 unsigned long pages
[NR_LRU_LISTS
];
4425 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4426 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
4429 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4432 * Estimate the amount of memory available for userspace allocations,
4433 * without causing swapping.
4435 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4438 * Not all the page cache can be freed, otherwise the system will
4439 * start swapping. Assume at least half of the page cache, or the
4440 * low watermark worth of cache, needs to stay.
4442 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4443 pagecache
-= min(pagecache
/ 2, wmark_low
);
4444 available
+= pagecache
;
4447 * Part of the reclaimable slab consists of items that are in use,
4448 * and cannot be freed. Cap this estimate at the low watermark.
4450 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
4451 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
4457 EXPORT_SYMBOL_GPL(si_mem_available
);
4459 void si_meminfo(struct sysinfo
*val
)
4461 val
->totalram
= totalram_pages
;
4462 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4463 val
->freeram
= global_page_state(NR_FREE_PAGES
);
4464 val
->bufferram
= nr_blockdev_pages();
4465 val
->totalhigh
= totalhigh_pages
;
4466 val
->freehigh
= nr_free_highpages();
4467 val
->mem_unit
= PAGE_SIZE
;
4470 EXPORT_SYMBOL(si_meminfo
);
4473 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4475 int zone_type
; /* needs to be signed */
4476 unsigned long managed_pages
= 0;
4477 unsigned long managed_highpages
= 0;
4478 unsigned long free_highpages
= 0;
4479 pg_data_t
*pgdat
= NODE_DATA(nid
);
4481 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4482 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4483 val
->totalram
= managed_pages
;
4484 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4485 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4486 #ifdef CONFIG_HIGHMEM
4487 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4488 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4490 if (is_highmem(zone
)) {
4491 managed_highpages
+= zone
->managed_pages
;
4492 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4495 val
->totalhigh
= managed_highpages
;
4496 val
->freehigh
= free_highpages
;
4498 val
->totalhigh
= managed_highpages
;
4499 val
->freehigh
= free_highpages
;
4501 val
->mem_unit
= PAGE_SIZE
;
4506 * Determine whether the node should be displayed or not, depending on whether
4507 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4509 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
4511 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4515 * no node mask - aka implicit memory numa policy. Do not bother with
4516 * the synchronization - read_mems_allowed_begin - because we do not
4517 * have to be precise here.
4520 nodemask
= &cpuset_current_mems_allowed
;
4522 return !node_isset(nid
, *nodemask
);
4525 #define K(x) ((x) << (PAGE_SHIFT-10))
4527 static void show_migration_types(unsigned char type
)
4529 static const char types
[MIGRATE_TYPES
] = {
4530 [MIGRATE_UNMOVABLE
] = 'U',
4531 [MIGRATE_MOVABLE
] = 'M',
4532 [MIGRATE_RECLAIMABLE
] = 'E',
4533 [MIGRATE_HIGHATOMIC
] = 'H',
4535 [MIGRATE_CMA
] = 'C',
4537 #ifdef CONFIG_MEMORY_ISOLATION
4538 [MIGRATE_ISOLATE
] = 'I',
4541 char tmp
[MIGRATE_TYPES
+ 1];
4545 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4546 if (type
& (1 << i
))
4551 printk(KERN_CONT
"(%s) ", tmp
);
4555 * Show free area list (used inside shift_scroll-lock stuff)
4556 * We also calculate the percentage fragmentation. We do this by counting the
4557 * memory on each free list with the exception of the first item on the list.
4560 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4563 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
4565 unsigned long free_pcp
= 0;
4570 for_each_populated_zone(zone
) {
4571 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4574 for_each_online_cpu(cpu
)
4575 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4578 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4579 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4580 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4581 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4582 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4583 " free:%lu free_pcp:%lu free_cma:%lu\n",
4584 global_node_page_state(NR_ACTIVE_ANON
),
4585 global_node_page_state(NR_INACTIVE_ANON
),
4586 global_node_page_state(NR_ISOLATED_ANON
),
4587 global_node_page_state(NR_ACTIVE_FILE
),
4588 global_node_page_state(NR_INACTIVE_FILE
),
4589 global_node_page_state(NR_ISOLATED_FILE
),
4590 global_node_page_state(NR_UNEVICTABLE
),
4591 global_node_page_state(NR_FILE_DIRTY
),
4592 global_node_page_state(NR_WRITEBACK
),
4593 global_node_page_state(NR_UNSTABLE_NFS
),
4594 global_page_state(NR_SLAB_RECLAIMABLE
),
4595 global_page_state(NR_SLAB_UNRECLAIMABLE
),
4596 global_node_page_state(NR_FILE_MAPPED
),
4597 global_node_page_state(NR_SHMEM
),
4598 global_page_state(NR_PAGETABLE
),
4599 global_page_state(NR_BOUNCE
),
4600 global_page_state(NR_FREE_PAGES
),
4602 global_page_state(NR_FREE_CMA_PAGES
));
4604 for_each_online_pgdat(pgdat
) {
4605 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
4609 " active_anon:%lukB"
4610 " inactive_anon:%lukB"
4611 " active_file:%lukB"
4612 " inactive_file:%lukB"
4613 " unevictable:%lukB"
4614 " isolated(anon):%lukB"
4615 " isolated(file):%lukB"
4620 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4622 " shmem_pmdmapped: %lukB"
4625 " writeback_tmp:%lukB"
4627 " all_unreclaimable? %s"
4630 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4631 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4632 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4633 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4634 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4635 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4636 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4637 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4638 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4639 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4640 K(node_page_state(pgdat
, NR_SHMEM
)),
4641 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4642 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4643 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4645 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4647 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4648 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4649 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
4653 for_each_populated_zone(zone
) {
4656 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4660 for_each_online_cpu(cpu
)
4661 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4670 " active_anon:%lukB"
4671 " inactive_anon:%lukB"
4672 " active_file:%lukB"
4673 " inactive_file:%lukB"
4674 " unevictable:%lukB"
4675 " writepending:%lukB"
4679 " kernel_stack:%lukB"
4687 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4688 K(min_wmark_pages(zone
)),
4689 K(low_wmark_pages(zone
)),
4690 K(high_wmark_pages(zone
)),
4691 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4692 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4693 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4694 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4695 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4696 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4697 K(zone
->present_pages
),
4698 K(zone
->managed_pages
),
4699 K(zone_page_state(zone
, NR_MLOCK
)),
4700 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4701 K(zone_page_state(zone
, NR_PAGETABLE
)),
4702 K(zone_page_state(zone
, NR_BOUNCE
)),
4704 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4705 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4706 printk("lowmem_reserve[]:");
4707 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4708 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
4709 printk(KERN_CONT
"\n");
4712 for_each_populated_zone(zone
) {
4714 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4715 unsigned char types
[MAX_ORDER
];
4717 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4720 printk(KERN_CONT
"%s: ", zone
->name
);
4722 spin_lock_irqsave(&zone
->lock
, flags
);
4723 for (order
= 0; order
< MAX_ORDER
; order
++) {
4724 struct free_area
*area
= &zone
->free_area
[order
];
4727 nr
[order
] = area
->nr_free
;
4728 total
+= nr
[order
] << order
;
4731 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4732 if (!list_empty(&area
->free_list
[type
]))
4733 types
[order
] |= 1 << type
;
4736 spin_unlock_irqrestore(&zone
->lock
, flags
);
4737 for (order
= 0; order
< MAX_ORDER
; order
++) {
4738 printk(KERN_CONT
"%lu*%lukB ",
4739 nr
[order
], K(1UL) << order
);
4741 show_migration_types(types
[order
]);
4743 printk(KERN_CONT
"= %lukB\n", K(total
));
4746 hugetlb_show_meminfo();
4748 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4750 show_swap_cache_info();
4753 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4755 zoneref
->zone
= zone
;
4756 zoneref
->zone_idx
= zone_idx(zone
);
4760 * Builds allocation fallback zone lists.
4762 * Add all populated zones of a node to the zonelist.
4764 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4768 enum zone_type zone_type
= MAX_NR_ZONES
;
4772 zone
= pgdat
->node_zones
+ zone_type
;
4773 if (managed_zone(zone
)) {
4774 zoneref_set_zone(zone
,
4775 &zonelist
->_zonerefs
[nr_zones
++]);
4776 check_highest_zone(zone_type
);
4778 } while (zone_type
);
4786 * 0 = automatic detection of better ordering.
4787 * 1 = order by ([node] distance, -zonetype)
4788 * 2 = order by (-zonetype, [node] distance)
4790 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4791 * the same zonelist. So only NUMA can configure this param.
4793 #define ZONELIST_ORDER_DEFAULT 0
4794 #define ZONELIST_ORDER_NODE 1
4795 #define ZONELIST_ORDER_ZONE 2
4797 /* zonelist order in the kernel.
4798 * set_zonelist_order() will set this to NODE or ZONE.
4800 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4801 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4805 /* The value user specified ....changed by config */
4806 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4807 /* string for sysctl */
4808 #define NUMA_ZONELIST_ORDER_LEN 16
4809 char numa_zonelist_order
[16] = "default";
4812 * interface for configure zonelist ordering.
4813 * command line option "numa_zonelist_order"
4814 * = "[dD]efault - default, automatic configuration.
4815 * = "[nN]ode - order by node locality, then by zone within node
4816 * = "[zZ]one - order by zone, then by locality within zone
4819 static int __parse_numa_zonelist_order(char *s
)
4821 if (*s
== 'd' || *s
== 'D') {
4822 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4823 } else if (*s
== 'n' || *s
== 'N') {
4824 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4825 } else if (*s
== 'z' || *s
== 'Z') {
4826 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4828 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4834 static __init
int setup_numa_zonelist_order(char *s
)
4841 ret
= __parse_numa_zonelist_order(s
);
4843 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4847 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4850 * sysctl handler for numa_zonelist_order
4852 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4853 void __user
*buffer
, size_t *length
,
4856 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4858 static DEFINE_MUTEX(zl_order_mutex
);
4860 mutex_lock(&zl_order_mutex
);
4862 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4866 strcpy(saved_string
, (char *)table
->data
);
4868 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4872 int oldval
= user_zonelist_order
;
4874 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4877 * bogus value. restore saved string
4879 strncpy((char *)table
->data
, saved_string
,
4880 NUMA_ZONELIST_ORDER_LEN
);
4881 user_zonelist_order
= oldval
;
4882 } else if (oldval
!= user_zonelist_order
) {
4883 mutex_lock(&zonelists_mutex
);
4884 build_all_zonelists(NULL
, NULL
);
4885 mutex_unlock(&zonelists_mutex
);
4889 mutex_unlock(&zl_order_mutex
);
4894 #define MAX_NODE_LOAD (nr_online_nodes)
4895 static int node_load
[MAX_NUMNODES
];
4898 * find_next_best_node - find the next node that should appear in a given node's fallback list
4899 * @node: node whose fallback list we're appending
4900 * @used_node_mask: nodemask_t of already used nodes
4902 * We use a number of factors to determine which is the next node that should
4903 * appear on a given node's fallback list. The node should not have appeared
4904 * already in @node's fallback list, and it should be the next closest node
4905 * according to the distance array (which contains arbitrary distance values
4906 * from each node to each node in the system), and should also prefer nodes
4907 * with no CPUs, since presumably they'll have very little allocation pressure
4908 * on them otherwise.
4909 * It returns -1 if no node is found.
4911 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4914 int min_val
= INT_MAX
;
4915 int best_node
= NUMA_NO_NODE
;
4916 const struct cpumask
*tmp
= cpumask_of_node(0);
4918 /* Use the local node if we haven't already */
4919 if (!node_isset(node
, *used_node_mask
)) {
4920 node_set(node
, *used_node_mask
);
4924 for_each_node_state(n
, N_MEMORY
) {
4926 /* Don't want a node to appear more than once */
4927 if (node_isset(n
, *used_node_mask
))
4930 /* Use the distance array to find the distance */
4931 val
= node_distance(node
, n
);
4933 /* Penalize nodes under us ("prefer the next node") */
4936 /* Give preference to headless and unused nodes */
4937 tmp
= cpumask_of_node(n
);
4938 if (!cpumask_empty(tmp
))
4939 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4941 /* Slight preference for less loaded node */
4942 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4943 val
+= node_load
[n
];
4945 if (val
< min_val
) {
4952 node_set(best_node
, *used_node_mask
);
4959 * Build zonelists ordered by node and zones within node.
4960 * This results in maximum locality--normal zone overflows into local
4961 * DMA zone, if any--but risks exhausting DMA zone.
4963 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4966 struct zonelist
*zonelist
;
4968 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
4969 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4971 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4972 zonelist
->_zonerefs
[j
].zone
= NULL
;
4973 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4977 * Build gfp_thisnode zonelists
4979 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4982 struct zonelist
*zonelist
;
4984 zonelist
= &pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
];
4985 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4986 zonelist
->_zonerefs
[j
].zone
= NULL
;
4987 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4991 * Build zonelists ordered by zone and nodes within zones.
4992 * This results in conserving DMA zone[s] until all Normal memory is
4993 * exhausted, but results in overflowing to remote node while memory
4994 * may still exist in local DMA zone.
4996 static int node_order
[MAX_NUMNODES
];
4998 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
5001 int zone_type
; /* needs to be signed */
5003 struct zonelist
*zonelist
;
5005 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
5007 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
5008 for (j
= 0; j
< nr_nodes
; j
++) {
5009 node
= node_order
[j
];
5010 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
5011 if (managed_zone(z
)) {
5013 &zonelist
->_zonerefs
[pos
++]);
5014 check_highest_zone(zone_type
);
5018 zonelist
->_zonerefs
[pos
].zone
= NULL
;
5019 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
5022 #if defined(CONFIG_64BIT)
5024 * Devices that require DMA32/DMA are relatively rare and do not justify a
5025 * penalty to every machine in case the specialised case applies. Default
5026 * to Node-ordering on 64-bit NUMA machines
5028 static int default_zonelist_order(void)
5030 return ZONELIST_ORDER_NODE
;
5034 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
5035 * by the kernel. If processes running on node 0 deplete the low memory zone
5036 * then reclaim will occur more frequency increasing stalls and potentially
5037 * be easier to OOM if a large percentage of the zone is under writeback or
5038 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
5039 * Hence, default to zone ordering on 32-bit.
5041 static int default_zonelist_order(void)
5043 return ZONELIST_ORDER_ZONE
;
5045 #endif /* CONFIG_64BIT */
5047 static void set_zonelist_order(void)
5049 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
5050 current_zonelist_order
= default_zonelist_order();
5052 current_zonelist_order
= user_zonelist_order
;
5055 static void build_zonelists(pg_data_t
*pgdat
)
5058 nodemask_t used_mask
;
5059 int local_node
, prev_node
;
5060 struct zonelist
*zonelist
;
5061 unsigned int order
= current_zonelist_order
;
5063 /* initialize zonelists */
5064 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
5065 zonelist
= pgdat
->node_zonelists
+ i
;
5066 zonelist
->_zonerefs
[0].zone
= NULL
;
5067 zonelist
->_zonerefs
[0].zone_idx
= 0;
5070 /* NUMA-aware ordering of nodes */
5071 local_node
= pgdat
->node_id
;
5072 load
= nr_online_nodes
;
5073 prev_node
= local_node
;
5074 nodes_clear(used_mask
);
5076 memset(node_order
, 0, sizeof(node_order
));
5079 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5081 * We don't want to pressure a particular node.
5082 * So adding penalty to the first node in same
5083 * distance group to make it round-robin.
5085 if (node_distance(local_node
, node
) !=
5086 node_distance(local_node
, prev_node
))
5087 node_load
[node
] = load
;
5091 if (order
== ZONELIST_ORDER_NODE
)
5092 build_zonelists_in_node_order(pgdat
, node
);
5094 node_order
[i
++] = node
; /* remember order */
5097 if (order
== ZONELIST_ORDER_ZONE
) {
5098 /* calculate node order -- i.e., DMA last! */
5099 build_zonelists_in_zone_order(pgdat
, i
);
5102 build_thisnode_zonelists(pgdat
);
5105 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5107 * Return node id of node used for "local" allocations.
5108 * I.e., first node id of first zone in arg node's generic zonelist.
5109 * Used for initializing percpu 'numa_mem', which is used primarily
5110 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5112 int local_memory_node(int node
)
5116 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5117 gfp_zone(GFP_KERNEL
),
5119 return z
->zone
->node
;
5123 static void setup_min_unmapped_ratio(void);
5124 static void setup_min_slab_ratio(void);
5125 #else /* CONFIG_NUMA */
5127 static void set_zonelist_order(void)
5129 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
5132 static void build_zonelists(pg_data_t
*pgdat
)
5134 int node
, local_node
;
5136 struct zonelist
*zonelist
;
5138 local_node
= pgdat
->node_id
;
5140 zonelist
= &pgdat
->node_zonelists
[ZONELIST_FALLBACK
];
5141 j
= build_zonelists_node(pgdat
, zonelist
, 0);
5144 * Now we build the zonelist so that it contains the zones
5145 * of all the other nodes.
5146 * We don't want to pressure a particular node, so when
5147 * building the zones for node N, we make sure that the
5148 * zones coming right after the local ones are those from
5149 * node N+1 (modulo N)
5151 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5152 if (!node_online(node
))
5154 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5156 for (node
= 0; node
< local_node
; node
++) {
5157 if (!node_online(node
))
5159 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
5162 zonelist
->_zonerefs
[j
].zone
= NULL
;
5163 zonelist
->_zonerefs
[j
].zone_idx
= 0;
5166 #endif /* CONFIG_NUMA */
5169 * Boot pageset table. One per cpu which is going to be used for all
5170 * zones and all nodes. The parameters will be set in such a way
5171 * that an item put on a list will immediately be handed over to
5172 * the buddy list. This is safe since pageset manipulation is done
5173 * with interrupts disabled.
5175 * The boot_pagesets must be kept even after bootup is complete for
5176 * unused processors and/or zones. They do play a role for bootstrapping
5177 * hotplugged processors.
5179 * zoneinfo_show() and maybe other functions do
5180 * not check if the processor is online before following the pageset pointer.
5181 * Other parts of the kernel may not check if the zone is available.
5183 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5184 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5185 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5186 static void setup_zone_pageset(struct zone
*zone
);
5189 * Global mutex to protect against size modification of zonelists
5190 * as well as to serialize pageset setup for the new populated zone.
5192 DEFINE_MUTEX(zonelists_mutex
);
5194 /* return values int ....just for stop_machine() */
5195 static int __build_all_zonelists(void *data
)
5199 pg_data_t
*self
= data
;
5202 memset(node_load
, 0, sizeof(node_load
));
5205 if (self
&& !node_online(self
->node_id
)) {
5206 build_zonelists(self
);
5209 for_each_online_node(nid
) {
5210 pg_data_t
*pgdat
= NODE_DATA(nid
);
5212 build_zonelists(pgdat
);
5216 * Initialize the boot_pagesets that are going to be used
5217 * for bootstrapping processors. The real pagesets for
5218 * each zone will be allocated later when the per cpu
5219 * allocator is available.
5221 * boot_pagesets are used also for bootstrapping offline
5222 * cpus if the system is already booted because the pagesets
5223 * are needed to initialize allocators on a specific cpu too.
5224 * F.e. the percpu allocator needs the page allocator which
5225 * needs the percpu allocator in order to allocate its pagesets
5226 * (a chicken-egg dilemma).
5228 for_each_possible_cpu(cpu
) {
5229 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5231 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5233 * We now know the "local memory node" for each node--
5234 * i.e., the node of the first zone in the generic zonelist.
5235 * Set up numa_mem percpu variable for on-line cpus. During
5236 * boot, only the boot cpu should be on-line; we'll init the
5237 * secondary cpus' numa_mem as they come on-line. During
5238 * node/memory hotplug, we'll fixup all on-line cpus.
5240 if (cpu_online(cpu
))
5241 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5248 static noinline
void __init
5249 build_all_zonelists_init(void)
5251 __build_all_zonelists(NULL
);
5252 mminit_verify_zonelist();
5253 cpuset_init_current_mems_allowed();
5257 * Called with zonelists_mutex held always
5258 * unless system_state == SYSTEM_BOOTING.
5260 * __ref due to (1) call of __meminit annotated setup_zone_pageset
5261 * [we're only called with non-NULL zone through __meminit paths] and
5262 * (2) call of __init annotated helper build_all_zonelists_init
5263 * [protected by SYSTEM_BOOTING].
5265 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
5267 set_zonelist_order();
5269 if (system_state
== SYSTEM_BOOTING
) {
5270 build_all_zonelists_init();
5272 #ifdef CONFIG_MEMORY_HOTPLUG
5274 setup_zone_pageset(zone
);
5276 /* we have to stop all cpus to guarantee there is no user
5278 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
5279 /* cpuset refresh routine should be here */
5281 vm_total_pages
= nr_free_pagecache_pages();
5283 * Disable grouping by mobility if the number of pages in the
5284 * system is too low to allow the mechanism to work. It would be
5285 * more accurate, but expensive to check per-zone. This check is
5286 * made on memory-hotadd so a system can start with mobility
5287 * disabled and enable it later
5289 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5290 page_group_by_mobility_disabled
= 1;
5292 page_group_by_mobility_disabled
= 0;
5294 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
5296 zonelist_order_name
[current_zonelist_order
],
5297 page_group_by_mobility_disabled
? "off" : "on",
5300 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5305 * Initially all pages are reserved - free ones are freed
5306 * up by free_all_bootmem() once the early boot process is
5307 * done. Non-atomic initialization, single-pass.
5309 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5310 unsigned long start_pfn
, enum memmap_context context
)
5312 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
5313 unsigned long end_pfn
= start_pfn
+ size
;
5314 pg_data_t
*pgdat
= NODE_DATA(nid
);
5316 unsigned long nr_initialised
= 0;
5317 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5318 struct memblock_region
*r
= NULL
, *tmp
;
5321 if (highest_memmap_pfn
< end_pfn
- 1)
5322 highest_memmap_pfn
= end_pfn
- 1;
5325 * Honor reservation requested by the driver for this ZONE_DEVICE
5328 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5329 start_pfn
+= altmap
->reserve
;
5331 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5333 * There can be holes in boot-time mem_map[]s handed to this
5334 * function. They do not exist on hotplugged memory.
5336 if (context
!= MEMMAP_EARLY
)
5339 if (!early_pfn_valid(pfn
)) {
5340 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5342 * Skip to the pfn preceding the next valid one (or
5343 * end_pfn), such that we hit a valid pfn (or end_pfn)
5344 * on our next iteration of the loop.
5346 pfn
= memblock_next_valid_pfn(pfn
, end_pfn
) - 1;
5350 if (!early_pfn_in_nid(pfn
, nid
))
5352 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5355 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5357 * Check given memblock attribute by firmware which can affect
5358 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5359 * mirrored, it's an overlapped memmap init. skip it.
5361 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5362 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5363 for_each_memblock(memory
, tmp
)
5364 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5368 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5369 memblock_is_mirror(r
)) {
5370 /* already initialized as NORMAL */
5371 pfn
= memblock_region_memory_end_pfn(r
);
5379 * Mark the block movable so that blocks are reserved for
5380 * movable at startup. This will force kernel allocations
5381 * to reserve their blocks rather than leaking throughout
5382 * the address space during boot when many long-lived
5383 * kernel allocations are made.
5385 * bitmap is created for zone's valid pfn range. but memmap
5386 * can be created for invalid pages (for alignment)
5387 * check here not to call set_pageblock_migratetype() against
5390 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5391 struct page
*page
= pfn_to_page(pfn
);
5393 __init_single_page(page
, pfn
, zone
, nid
);
5394 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5396 __init_single_pfn(pfn
, zone
, nid
);
5401 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5403 unsigned int order
, t
;
5404 for_each_migratetype_order(order
, t
) {
5405 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5406 zone
->free_area
[order
].nr_free
= 0;
5410 #ifndef __HAVE_ARCH_MEMMAP_INIT
5411 #define memmap_init(size, nid, zone, start_pfn) \
5412 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5415 static int zone_batchsize(struct zone
*zone
)
5421 * The per-cpu-pages pools are set to around 1000th of the
5422 * size of the zone. But no more than 1/2 of a meg.
5424 * OK, so we don't know how big the cache is. So guess.
5426 batch
= zone
->managed_pages
/ 1024;
5427 if (batch
* PAGE_SIZE
> 512 * 1024)
5428 batch
= (512 * 1024) / PAGE_SIZE
;
5429 batch
/= 4; /* We effectively *= 4 below */
5434 * Clamp the batch to a 2^n - 1 value. Having a power
5435 * of 2 value was found to be more likely to have
5436 * suboptimal cache aliasing properties in some cases.
5438 * For example if 2 tasks are alternately allocating
5439 * batches of pages, one task can end up with a lot
5440 * of pages of one half of the possible page colors
5441 * and the other with pages of the other colors.
5443 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5448 /* The deferral and batching of frees should be suppressed under NOMMU
5451 * The problem is that NOMMU needs to be able to allocate large chunks
5452 * of contiguous memory as there's no hardware page translation to
5453 * assemble apparent contiguous memory from discontiguous pages.
5455 * Queueing large contiguous runs of pages for batching, however,
5456 * causes the pages to actually be freed in smaller chunks. As there
5457 * can be a significant delay between the individual batches being
5458 * recycled, this leads to the once large chunks of space being
5459 * fragmented and becoming unavailable for high-order allocations.
5466 * pcp->high and pcp->batch values are related and dependent on one another:
5467 * ->batch must never be higher then ->high.
5468 * The following function updates them in a safe manner without read side
5471 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5472 * those fields changing asynchronously (acording the the above rule).
5474 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5475 * outside of boot time (or some other assurance that no concurrent updaters
5478 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5479 unsigned long batch
)
5481 /* start with a fail safe value for batch */
5485 /* Update high, then batch, in order */
5492 /* a companion to pageset_set_high() */
5493 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5495 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5498 static void pageset_init(struct per_cpu_pageset
*p
)
5500 struct per_cpu_pages
*pcp
;
5503 memset(p
, 0, sizeof(*p
));
5507 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5508 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5511 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5514 pageset_set_batch(p
, batch
);
5518 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5519 * to the value high for the pageset p.
5521 static void pageset_set_high(struct per_cpu_pageset
*p
,
5524 unsigned long batch
= max(1UL, high
/ 4);
5525 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5526 batch
= PAGE_SHIFT
* 8;
5528 pageset_update(&p
->pcp
, high
, batch
);
5531 static void pageset_set_high_and_batch(struct zone
*zone
,
5532 struct per_cpu_pageset
*pcp
)
5534 if (percpu_pagelist_fraction
)
5535 pageset_set_high(pcp
,
5536 (zone
->managed_pages
/
5537 percpu_pagelist_fraction
));
5539 pageset_set_batch(pcp
, zone_batchsize(zone
));
5542 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5544 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5547 pageset_set_high_and_batch(zone
, pcp
);
5550 static void __meminit
setup_zone_pageset(struct zone
*zone
)
5553 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5554 for_each_possible_cpu(cpu
)
5555 zone_pageset_init(zone
, cpu
);
5559 * Allocate per cpu pagesets and initialize them.
5560 * Before this call only boot pagesets were available.
5562 void __init
setup_per_cpu_pageset(void)
5564 struct pglist_data
*pgdat
;
5567 for_each_populated_zone(zone
)
5568 setup_zone_pageset(zone
);
5570 for_each_online_pgdat(pgdat
)
5571 pgdat
->per_cpu_nodestats
=
5572 alloc_percpu(struct per_cpu_nodestat
);
5575 static __meminit
void zone_pcp_init(struct zone
*zone
)
5578 * per cpu subsystem is not up at this point. The following code
5579 * relies on the ability of the linker to provide the
5580 * offset of a (static) per cpu variable into the per cpu area.
5582 zone
->pageset
= &boot_pageset
;
5584 if (populated_zone(zone
))
5585 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5586 zone
->name
, zone
->present_pages
,
5587 zone_batchsize(zone
));
5590 void __meminit
init_currently_empty_zone(struct zone
*zone
,
5591 unsigned long zone_start_pfn
,
5594 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5596 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5598 zone
->zone_start_pfn
= zone_start_pfn
;
5600 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5601 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5603 (unsigned long)zone_idx(zone
),
5604 zone_start_pfn
, (zone_start_pfn
+ size
));
5606 zone_init_free_lists(zone
);
5607 zone
->initialized
= 1;
5610 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5611 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5614 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5616 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5617 struct mminit_pfnnid_cache
*state
)
5619 unsigned long start_pfn
, end_pfn
;
5622 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5623 return state
->last_nid
;
5625 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5627 state
->last_start
= start_pfn
;
5628 state
->last_end
= end_pfn
;
5629 state
->last_nid
= nid
;
5634 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5637 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5638 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5639 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5641 * If an architecture guarantees that all ranges registered contain no holes
5642 * and may be freed, this this function may be used instead of calling
5643 * memblock_free_early_nid() manually.
5645 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5647 unsigned long start_pfn
, end_pfn
;
5650 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5651 start_pfn
= min(start_pfn
, max_low_pfn
);
5652 end_pfn
= min(end_pfn
, max_low_pfn
);
5654 if (start_pfn
< end_pfn
)
5655 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5656 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5662 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5663 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5665 * If an architecture guarantees that all ranges registered contain no holes and may
5666 * be freed, this function may be used instead of calling memory_present() manually.
5668 void __init
sparse_memory_present_with_active_regions(int nid
)
5670 unsigned long start_pfn
, end_pfn
;
5673 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5674 memory_present(this_nid
, start_pfn
, end_pfn
);
5678 * get_pfn_range_for_nid - Return the start and end page frames for a node
5679 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5680 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5681 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5683 * It returns the start and end page frame of a node based on information
5684 * provided by memblock_set_node(). If called for a node
5685 * with no available memory, a warning is printed and the start and end
5688 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5689 unsigned long *start_pfn
, unsigned long *end_pfn
)
5691 unsigned long this_start_pfn
, this_end_pfn
;
5697 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5698 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5699 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5702 if (*start_pfn
== -1UL)
5707 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5708 * assumption is made that zones within a node are ordered in monotonic
5709 * increasing memory addresses so that the "highest" populated zone is used
5711 static void __init
find_usable_zone_for_movable(void)
5714 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5715 if (zone_index
== ZONE_MOVABLE
)
5718 if (arch_zone_highest_possible_pfn
[zone_index
] >
5719 arch_zone_lowest_possible_pfn
[zone_index
])
5723 VM_BUG_ON(zone_index
== -1);
5724 movable_zone
= zone_index
;
5728 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5729 * because it is sized independent of architecture. Unlike the other zones,
5730 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5731 * in each node depending on the size of each node and how evenly kernelcore
5732 * is distributed. This helper function adjusts the zone ranges
5733 * provided by the architecture for a given node by using the end of the
5734 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5735 * zones within a node are in order of monotonic increases memory addresses
5737 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5738 unsigned long zone_type
,
5739 unsigned long node_start_pfn
,
5740 unsigned long node_end_pfn
,
5741 unsigned long *zone_start_pfn
,
5742 unsigned long *zone_end_pfn
)
5744 /* Only adjust if ZONE_MOVABLE is on this node */
5745 if (zone_movable_pfn
[nid
]) {
5746 /* Size ZONE_MOVABLE */
5747 if (zone_type
== ZONE_MOVABLE
) {
5748 *zone_start_pfn
= zone_movable_pfn
[nid
];
5749 *zone_end_pfn
= min(node_end_pfn
,
5750 arch_zone_highest_possible_pfn
[movable_zone
]);
5752 /* Adjust for ZONE_MOVABLE starting within this range */
5753 } else if (!mirrored_kernelcore
&&
5754 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
5755 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5756 *zone_end_pfn
= zone_movable_pfn
[nid
];
5758 /* Check if this whole range is within ZONE_MOVABLE */
5759 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5760 *zone_start_pfn
= *zone_end_pfn
;
5765 * Return the number of pages a zone spans in a node, including holes
5766 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5768 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5769 unsigned long zone_type
,
5770 unsigned long node_start_pfn
,
5771 unsigned long node_end_pfn
,
5772 unsigned long *zone_start_pfn
,
5773 unsigned long *zone_end_pfn
,
5774 unsigned long *ignored
)
5776 /* When hotadd a new node from cpu_up(), the node should be empty */
5777 if (!node_start_pfn
&& !node_end_pfn
)
5780 /* Get the start and end of the zone */
5781 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5782 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5783 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5784 node_start_pfn
, node_end_pfn
,
5785 zone_start_pfn
, zone_end_pfn
);
5787 /* Check that this node has pages within the zone's required range */
5788 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5791 /* Move the zone boundaries inside the node if necessary */
5792 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5793 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5795 /* Return the spanned pages */
5796 return *zone_end_pfn
- *zone_start_pfn
;
5800 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5801 * then all holes in the requested range will be accounted for.
5803 unsigned long __meminit
__absent_pages_in_range(int nid
,
5804 unsigned long range_start_pfn
,
5805 unsigned long range_end_pfn
)
5807 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5808 unsigned long start_pfn
, end_pfn
;
5811 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5812 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5813 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5814 nr_absent
-= end_pfn
- start_pfn
;
5820 * absent_pages_in_range - Return number of page frames in holes within a range
5821 * @start_pfn: The start PFN to start searching for holes
5822 * @end_pfn: The end PFN to stop searching for holes
5824 * It returns the number of pages frames in memory holes within a range.
5826 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5827 unsigned long end_pfn
)
5829 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5832 /* Return the number of page frames in holes in a zone on a node */
5833 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5834 unsigned long zone_type
,
5835 unsigned long node_start_pfn
,
5836 unsigned long node_end_pfn
,
5837 unsigned long *ignored
)
5839 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5840 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5841 unsigned long zone_start_pfn
, zone_end_pfn
;
5842 unsigned long nr_absent
;
5844 /* When hotadd a new node from cpu_up(), the node should be empty */
5845 if (!node_start_pfn
&& !node_end_pfn
)
5848 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5849 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5851 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5852 node_start_pfn
, node_end_pfn
,
5853 &zone_start_pfn
, &zone_end_pfn
);
5854 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5857 * ZONE_MOVABLE handling.
5858 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5861 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
5862 unsigned long start_pfn
, end_pfn
;
5863 struct memblock_region
*r
;
5865 for_each_memblock(memory
, r
) {
5866 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5867 zone_start_pfn
, zone_end_pfn
);
5868 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5869 zone_start_pfn
, zone_end_pfn
);
5871 if (zone_type
== ZONE_MOVABLE
&&
5872 memblock_is_mirror(r
))
5873 nr_absent
+= end_pfn
- start_pfn
;
5875 if (zone_type
== ZONE_NORMAL
&&
5876 !memblock_is_mirror(r
))
5877 nr_absent
+= end_pfn
- start_pfn
;
5884 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5885 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5886 unsigned long zone_type
,
5887 unsigned long node_start_pfn
,
5888 unsigned long node_end_pfn
,
5889 unsigned long *zone_start_pfn
,
5890 unsigned long *zone_end_pfn
,
5891 unsigned long *zones_size
)
5895 *zone_start_pfn
= node_start_pfn
;
5896 for (zone
= 0; zone
< zone_type
; zone
++)
5897 *zone_start_pfn
+= zones_size
[zone
];
5899 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5901 return zones_size
[zone_type
];
5904 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5905 unsigned long zone_type
,
5906 unsigned long node_start_pfn
,
5907 unsigned long node_end_pfn
,
5908 unsigned long *zholes_size
)
5913 return zholes_size
[zone_type
];
5916 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5918 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5919 unsigned long node_start_pfn
,
5920 unsigned long node_end_pfn
,
5921 unsigned long *zones_size
,
5922 unsigned long *zholes_size
)
5924 unsigned long realtotalpages
= 0, totalpages
= 0;
5927 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5928 struct zone
*zone
= pgdat
->node_zones
+ i
;
5929 unsigned long zone_start_pfn
, zone_end_pfn
;
5930 unsigned long size
, real_size
;
5932 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5938 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5939 node_start_pfn
, node_end_pfn
,
5942 zone
->zone_start_pfn
= zone_start_pfn
;
5944 zone
->zone_start_pfn
= 0;
5945 zone
->spanned_pages
= size
;
5946 zone
->present_pages
= real_size
;
5949 realtotalpages
+= real_size
;
5952 pgdat
->node_spanned_pages
= totalpages
;
5953 pgdat
->node_present_pages
= realtotalpages
;
5954 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5958 #ifndef CONFIG_SPARSEMEM
5960 * Calculate the size of the zone->blockflags rounded to an unsigned long
5961 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5962 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5963 * round what is now in bits to nearest long in bits, then return it in
5966 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5968 unsigned long usemapsize
;
5970 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5971 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5972 usemapsize
= usemapsize
>> pageblock_order
;
5973 usemapsize
*= NR_PAGEBLOCK_BITS
;
5974 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5976 return usemapsize
/ 8;
5979 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5981 unsigned long zone_start_pfn
,
5982 unsigned long zonesize
)
5984 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5985 zone
->pageblock_flags
= NULL
;
5987 zone
->pageblock_flags
=
5988 memblock_virt_alloc_node_nopanic(usemapsize
,
5992 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5993 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5994 #endif /* CONFIG_SPARSEMEM */
5996 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5998 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5999 void __paginginit
set_pageblock_order(void)
6003 /* Check that pageblock_nr_pages has not already been setup */
6004 if (pageblock_order
)
6007 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6008 order
= HUGETLB_PAGE_ORDER
;
6010 order
= MAX_ORDER
- 1;
6013 * Assume the largest contiguous order of interest is a huge page.
6014 * This value may be variable depending on boot parameters on IA64 and
6017 pageblock_order
= order
;
6019 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6022 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6023 * is unused as pageblock_order is set at compile-time. See
6024 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6027 void __paginginit
set_pageblock_order(void)
6031 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6033 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
6034 unsigned long present_pages
)
6036 unsigned long pages
= spanned_pages
;
6039 * Provide a more accurate estimation if there are holes within
6040 * the zone and SPARSEMEM is in use. If there are holes within the
6041 * zone, each populated memory region may cost us one or two extra
6042 * memmap pages due to alignment because memmap pages for each
6043 * populated regions may not be naturally aligned on page boundary.
6044 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6046 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6047 IS_ENABLED(CONFIG_SPARSEMEM
))
6048 pages
= present_pages
;
6050 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6054 * Set up the zone data structures:
6055 * - mark all pages reserved
6056 * - mark all memory queues empty
6057 * - clear the memory bitmaps
6059 * NOTE: pgdat should get zeroed by caller.
6061 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
6064 int nid
= pgdat
->node_id
;
6066 pgdat_resize_init(pgdat
);
6067 #ifdef CONFIG_NUMA_BALANCING
6068 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
6069 pgdat
->numabalancing_migrate_nr_pages
= 0;
6070 pgdat
->numabalancing_migrate_next_window
= jiffies
;
6072 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6073 spin_lock_init(&pgdat
->split_queue_lock
);
6074 INIT_LIST_HEAD(&pgdat
->split_queue
);
6075 pgdat
->split_queue_len
= 0;
6077 init_waitqueue_head(&pgdat
->kswapd_wait
);
6078 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6079 #ifdef CONFIG_COMPACTION
6080 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6082 pgdat_page_ext_init(pgdat
);
6083 spin_lock_init(&pgdat
->lru_lock
);
6084 lruvec_init(node_lruvec(pgdat
));
6086 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6088 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6089 struct zone
*zone
= pgdat
->node_zones
+ j
;
6090 unsigned long size
, realsize
, freesize
, memmap_pages
;
6091 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6093 size
= zone
->spanned_pages
;
6094 realsize
= freesize
= zone
->present_pages
;
6097 * Adjust freesize so that it accounts for how much memory
6098 * is used by this zone for memmap. This affects the watermark
6099 * and per-cpu initialisations
6101 memmap_pages
= calc_memmap_size(size
, realsize
);
6102 if (!is_highmem_idx(j
)) {
6103 if (freesize
>= memmap_pages
) {
6104 freesize
-= memmap_pages
;
6107 " %s zone: %lu pages used for memmap\n",
6108 zone_names
[j
], memmap_pages
);
6110 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6111 zone_names
[j
], memmap_pages
, freesize
);
6114 /* Account for reserved pages */
6115 if (j
== 0 && freesize
> dma_reserve
) {
6116 freesize
-= dma_reserve
;
6117 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6118 zone_names
[0], dma_reserve
);
6121 if (!is_highmem_idx(j
))
6122 nr_kernel_pages
+= freesize
;
6123 /* Charge for highmem memmap if there are enough kernel pages */
6124 else if (nr_kernel_pages
> memmap_pages
* 2)
6125 nr_kernel_pages
-= memmap_pages
;
6126 nr_all_pages
+= freesize
;
6129 * Set an approximate value for lowmem here, it will be adjusted
6130 * when the bootmem allocator frees pages into the buddy system.
6131 * And all highmem pages will be managed by the buddy system.
6133 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
6137 zone
->name
= zone_names
[j
];
6138 zone
->zone_pgdat
= pgdat
;
6139 spin_lock_init(&zone
->lock
);
6140 zone_seqlock_init(zone
);
6141 zone_pcp_init(zone
);
6146 set_pageblock_order();
6147 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6148 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6149 memmap_init(size
, nid
, j
, zone_start_pfn
);
6153 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6155 unsigned long __maybe_unused start
= 0;
6156 unsigned long __maybe_unused offset
= 0;
6158 /* Skip empty nodes */
6159 if (!pgdat
->node_spanned_pages
)
6162 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6163 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6164 offset
= pgdat
->node_start_pfn
- start
;
6165 /* ia64 gets its own node_mem_map, before this, without bootmem */
6166 if (!pgdat
->node_mem_map
) {
6167 unsigned long size
, end
;
6171 * The zone's endpoints aren't required to be MAX_ORDER
6172 * aligned but the node_mem_map endpoints must be in order
6173 * for the buddy allocator to function correctly.
6175 end
= pgdat_end_pfn(pgdat
);
6176 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6177 size
= (end
- start
) * sizeof(struct page
);
6178 map
= alloc_remap(pgdat
->node_id
, size
);
6180 map
= memblock_virt_alloc_node_nopanic(size
,
6182 pgdat
->node_mem_map
= map
+ offset
;
6184 #ifndef CONFIG_NEED_MULTIPLE_NODES
6186 * With no DISCONTIG, the global mem_map is just set as node 0's
6188 if (pgdat
== NODE_DATA(0)) {
6189 mem_map
= NODE_DATA(0)->node_mem_map
;
6190 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6191 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6193 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6196 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6199 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6200 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6202 pg_data_t
*pgdat
= NODE_DATA(nid
);
6203 unsigned long start_pfn
= 0;
6204 unsigned long end_pfn
= 0;
6206 /* pg_data_t should be reset to zero when it's allocated */
6207 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6209 pgdat
->node_id
= nid
;
6210 pgdat
->node_start_pfn
= node_start_pfn
;
6211 pgdat
->per_cpu_nodestats
= NULL
;
6212 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6213 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6214 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6215 (u64
)start_pfn
<< PAGE_SHIFT
,
6216 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6218 start_pfn
= node_start_pfn
;
6220 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6221 zones_size
, zholes_size
);
6223 alloc_node_mem_map(pgdat
);
6224 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6225 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
6226 nid
, (unsigned long)pgdat
,
6227 (unsigned long)pgdat
->node_mem_map
);
6230 reset_deferred_meminit(pgdat
);
6231 free_area_init_core(pgdat
);
6234 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6236 #if MAX_NUMNODES > 1
6238 * Figure out the number of possible node ids.
6240 void __init
setup_nr_node_ids(void)
6242 unsigned int highest
;
6244 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6245 nr_node_ids
= highest
+ 1;
6250 * node_map_pfn_alignment - determine the maximum internode alignment
6252 * This function should be called after node map is populated and sorted.
6253 * It calculates the maximum power of two alignment which can distinguish
6256 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6257 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6258 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6259 * shifted, 1GiB is enough and this function will indicate so.
6261 * This is used to test whether pfn -> nid mapping of the chosen memory
6262 * model has fine enough granularity to avoid incorrect mapping for the
6263 * populated node map.
6265 * Returns the determined alignment in pfn's. 0 if there is no alignment
6266 * requirement (single node).
6268 unsigned long __init
node_map_pfn_alignment(void)
6270 unsigned long accl_mask
= 0, last_end
= 0;
6271 unsigned long start
, end
, mask
;
6275 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6276 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6283 * Start with a mask granular enough to pin-point to the
6284 * start pfn and tick off bits one-by-one until it becomes
6285 * too coarse to separate the current node from the last.
6287 mask
= ~((1 << __ffs(start
)) - 1);
6288 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6291 /* accumulate all internode masks */
6295 /* convert mask to number of pages */
6296 return ~accl_mask
+ 1;
6299 /* Find the lowest pfn for a node */
6300 static unsigned long __init
find_min_pfn_for_node(int nid
)
6302 unsigned long min_pfn
= ULONG_MAX
;
6303 unsigned long start_pfn
;
6306 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6307 min_pfn
= min(min_pfn
, start_pfn
);
6309 if (min_pfn
== ULONG_MAX
) {
6310 pr_warn("Could not find start_pfn for node %d\n", nid
);
6318 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6320 * It returns the minimum PFN based on information provided via
6321 * memblock_set_node().
6323 unsigned long __init
find_min_pfn_with_active_regions(void)
6325 return find_min_pfn_for_node(MAX_NUMNODES
);
6329 * early_calculate_totalpages()
6330 * Sum pages in active regions for movable zone.
6331 * Populate N_MEMORY for calculating usable_nodes.
6333 static unsigned long __init
early_calculate_totalpages(void)
6335 unsigned long totalpages
= 0;
6336 unsigned long start_pfn
, end_pfn
;
6339 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6340 unsigned long pages
= end_pfn
- start_pfn
;
6342 totalpages
+= pages
;
6344 node_set_state(nid
, N_MEMORY
);
6350 * Find the PFN the Movable zone begins in each node. Kernel memory
6351 * is spread evenly between nodes as long as the nodes have enough
6352 * memory. When they don't, some nodes will have more kernelcore than
6355 static void __init
find_zone_movable_pfns_for_nodes(void)
6358 unsigned long usable_startpfn
;
6359 unsigned long kernelcore_node
, kernelcore_remaining
;
6360 /* save the state before borrow the nodemask */
6361 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6362 unsigned long totalpages
= early_calculate_totalpages();
6363 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6364 struct memblock_region
*r
;
6366 /* Need to find movable_zone earlier when movable_node is specified. */
6367 find_usable_zone_for_movable();
6370 * If movable_node is specified, ignore kernelcore and movablecore
6373 if (movable_node_is_enabled()) {
6374 for_each_memblock(memory
, r
) {
6375 if (!memblock_is_hotpluggable(r
))
6380 usable_startpfn
= PFN_DOWN(r
->base
);
6381 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6382 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6390 * If kernelcore=mirror is specified, ignore movablecore option
6392 if (mirrored_kernelcore
) {
6393 bool mem_below_4gb_not_mirrored
= false;
6395 for_each_memblock(memory
, r
) {
6396 if (memblock_is_mirror(r
))
6401 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6403 if (usable_startpfn
< 0x100000) {
6404 mem_below_4gb_not_mirrored
= true;
6408 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6409 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6413 if (mem_below_4gb_not_mirrored
)
6414 pr_warn("This configuration results in unmirrored kernel memory.");
6420 * If movablecore=nn[KMG] was specified, calculate what size of
6421 * kernelcore that corresponds so that memory usable for
6422 * any allocation type is evenly spread. If both kernelcore
6423 * and movablecore are specified, then the value of kernelcore
6424 * will be used for required_kernelcore if it's greater than
6425 * what movablecore would have allowed.
6427 if (required_movablecore
) {
6428 unsigned long corepages
;
6431 * Round-up so that ZONE_MOVABLE is at least as large as what
6432 * was requested by the user
6434 required_movablecore
=
6435 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6436 required_movablecore
= min(totalpages
, required_movablecore
);
6437 corepages
= totalpages
- required_movablecore
;
6439 required_kernelcore
= max(required_kernelcore
, corepages
);
6443 * If kernelcore was not specified or kernelcore size is larger
6444 * than totalpages, there is no ZONE_MOVABLE.
6446 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6449 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6450 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6453 /* Spread kernelcore memory as evenly as possible throughout nodes */
6454 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6455 for_each_node_state(nid
, N_MEMORY
) {
6456 unsigned long start_pfn
, end_pfn
;
6459 * Recalculate kernelcore_node if the division per node
6460 * now exceeds what is necessary to satisfy the requested
6461 * amount of memory for the kernel
6463 if (required_kernelcore
< kernelcore_node
)
6464 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6467 * As the map is walked, we track how much memory is usable
6468 * by the kernel using kernelcore_remaining. When it is
6469 * 0, the rest of the node is usable by ZONE_MOVABLE
6471 kernelcore_remaining
= kernelcore_node
;
6473 /* Go through each range of PFNs within this node */
6474 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6475 unsigned long size_pages
;
6477 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6478 if (start_pfn
>= end_pfn
)
6481 /* Account for what is only usable for kernelcore */
6482 if (start_pfn
< usable_startpfn
) {
6483 unsigned long kernel_pages
;
6484 kernel_pages
= min(end_pfn
, usable_startpfn
)
6487 kernelcore_remaining
-= min(kernel_pages
,
6488 kernelcore_remaining
);
6489 required_kernelcore
-= min(kernel_pages
,
6490 required_kernelcore
);
6492 /* Continue if range is now fully accounted */
6493 if (end_pfn
<= usable_startpfn
) {
6496 * Push zone_movable_pfn to the end so
6497 * that if we have to rebalance
6498 * kernelcore across nodes, we will
6499 * not double account here
6501 zone_movable_pfn
[nid
] = end_pfn
;
6504 start_pfn
= usable_startpfn
;
6508 * The usable PFN range for ZONE_MOVABLE is from
6509 * start_pfn->end_pfn. Calculate size_pages as the
6510 * number of pages used as kernelcore
6512 size_pages
= end_pfn
- start_pfn
;
6513 if (size_pages
> kernelcore_remaining
)
6514 size_pages
= kernelcore_remaining
;
6515 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6518 * Some kernelcore has been met, update counts and
6519 * break if the kernelcore for this node has been
6522 required_kernelcore
-= min(required_kernelcore
,
6524 kernelcore_remaining
-= size_pages
;
6525 if (!kernelcore_remaining
)
6531 * If there is still required_kernelcore, we do another pass with one
6532 * less node in the count. This will push zone_movable_pfn[nid] further
6533 * along on the nodes that still have memory until kernelcore is
6537 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6541 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6542 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6543 zone_movable_pfn
[nid
] =
6544 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6547 /* restore the node_state */
6548 node_states
[N_MEMORY
] = saved_node_state
;
6551 /* Any regular or high memory on that node ? */
6552 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6554 enum zone_type zone_type
;
6556 if (N_MEMORY
== N_NORMAL_MEMORY
)
6559 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6560 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6561 if (populated_zone(zone
)) {
6562 node_set_state(nid
, N_HIGH_MEMORY
);
6563 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6564 zone_type
<= ZONE_NORMAL
)
6565 node_set_state(nid
, N_NORMAL_MEMORY
);
6572 * free_area_init_nodes - Initialise all pg_data_t and zone data
6573 * @max_zone_pfn: an array of max PFNs for each zone
6575 * This will call free_area_init_node() for each active node in the system.
6576 * Using the page ranges provided by memblock_set_node(), the size of each
6577 * zone in each node and their holes is calculated. If the maximum PFN
6578 * between two adjacent zones match, it is assumed that the zone is empty.
6579 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6580 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6581 * starts where the previous one ended. For example, ZONE_DMA32 starts
6582 * at arch_max_dma_pfn.
6584 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6586 unsigned long start_pfn
, end_pfn
;
6589 /* Record where the zone boundaries are */
6590 memset(arch_zone_lowest_possible_pfn
, 0,
6591 sizeof(arch_zone_lowest_possible_pfn
));
6592 memset(arch_zone_highest_possible_pfn
, 0,
6593 sizeof(arch_zone_highest_possible_pfn
));
6595 start_pfn
= find_min_pfn_with_active_regions();
6597 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6598 if (i
== ZONE_MOVABLE
)
6601 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6602 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6603 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6605 start_pfn
= end_pfn
;
6608 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6609 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6610 find_zone_movable_pfns_for_nodes();
6612 /* Print out the zone ranges */
6613 pr_info("Zone ranges:\n");
6614 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6615 if (i
== ZONE_MOVABLE
)
6617 pr_info(" %-8s ", zone_names
[i
]);
6618 if (arch_zone_lowest_possible_pfn
[i
] ==
6619 arch_zone_highest_possible_pfn
[i
])
6622 pr_cont("[mem %#018Lx-%#018Lx]\n",
6623 (u64
)arch_zone_lowest_possible_pfn
[i
]
6625 ((u64
)arch_zone_highest_possible_pfn
[i
]
6626 << PAGE_SHIFT
) - 1);
6629 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6630 pr_info("Movable zone start for each node\n");
6631 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6632 if (zone_movable_pfn
[i
])
6633 pr_info(" Node %d: %#018Lx\n", i
,
6634 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6637 /* Print out the early node map */
6638 pr_info("Early memory node ranges\n");
6639 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6640 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6641 (u64
)start_pfn
<< PAGE_SHIFT
,
6642 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6644 /* Initialise every node */
6645 mminit_verify_pageflags_layout();
6646 setup_nr_node_ids();
6647 for_each_online_node(nid
) {
6648 pg_data_t
*pgdat
= NODE_DATA(nid
);
6649 free_area_init_node(nid
, NULL
,
6650 find_min_pfn_for_node(nid
), NULL
);
6652 /* Any memory on that node */
6653 if (pgdat
->node_present_pages
)
6654 node_set_state(nid
, N_MEMORY
);
6655 check_for_memory(pgdat
, nid
);
6659 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6661 unsigned long long coremem
;
6665 coremem
= memparse(p
, &p
);
6666 *core
= coremem
>> PAGE_SHIFT
;
6668 /* Paranoid check that UL is enough for the coremem value */
6669 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6675 * kernelcore=size sets the amount of memory for use for allocations that
6676 * cannot be reclaimed or migrated.
6678 static int __init
cmdline_parse_kernelcore(char *p
)
6680 /* parse kernelcore=mirror */
6681 if (parse_option_str(p
, "mirror")) {
6682 mirrored_kernelcore
= true;
6686 return cmdline_parse_core(p
, &required_kernelcore
);
6690 * movablecore=size sets the amount of memory for use for allocations that
6691 * can be reclaimed or migrated.
6693 static int __init
cmdline_parse_movablecore(char *p
)
6695 return cmdline_parse_core(p
, &required_movablecore
);
6698 early_param("kernelcore", cmdline_parse_kernelcore
);
6699 early_param("movablecore", cmdline_parse_movablecore
);
6701 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6703 void adjust_managed_page_count(struct page
*page
, long count
)
6705 spin_lock(&managed_page_count_lock
);
6706 page_zone(page
)->managed_pages
+= count
;
6707 totalram_pages
+= count
;
6708 #ifdef CONFIG_HIGHMEM
6709 if (PageHighMem(page
))
6710 totalhigh_pages
+= count
;
6712 spin_unlock(&managed_page_count_lock
);
6714 EXPORT_SYMBOL(adjust_managed_page_count
);
6716 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6719 unsigned long pages
= 0;
6721 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6722 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6723 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6724 if ((unsigned int)poison
<= 0xFF)
6725 memset(pos
, poison
, PAGE_SIZE
);
6726 free_reserved_page(virt_to_page(pos
));
6730 pr_info("Freeing %s memory: %ldK\n",
6731 s
, pages
<< (PAGE_SHIFT
- 10));
6735 EXPORT_SYMBOL(free_reserved_area
);
6737 #ifdef CONFIG_HIGHMEM
6738 void free_highmem_page(struct page
*page
)
6740 __free_reserved_page(page
);
6742 page_zone(page
)->managed_pages
++;
6748 void __init
mem_init_print_info(const char *str
)
6750 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6751 unsigned long init_code_size
, init_data_size
;
6753 physpages
= get_num_physpages();
6754 codesize
= _etext
- _stext
;
6755 datasize
= _edata
- _sdata
;
6756 rosize
= __end_rodata
- __start_rodata
;
6757 bss_size
= __bss_stop
- __bss_start
;
6758 init_data_size
= __init_end
- __init_begin
;
6759 init_code_size
= _einittext
- _sinittext
;
6762 * Detect special cases and adjust section sizes accordingly:
6763 * 1) .init.* may be embedded into .data sections
6764 * 2) .init.text.* may be out of [__init_begin, __init_end],
6765 * please refer to arch/tile/kernel/vmlinux.lds.S.
6766 * 3) .rodata.* may be embedded into .text or .data sections.
6768 #define adj_init_size(start, end, size, pos, adj) \
6770 if (start <= pos && pos < end && size > adj) \
6774 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6775 _sinittext
, init_code_size
);
6776 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6777 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6778 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6779 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6781 #undef adj_init_size
6783 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6784 #ifdef CONFIG_HIGHMEM
6788 nr_free_pages() << (PAGE_SHIFT
- 10),
6789 physpages
<< (PAGE_SHIFT
- 10),
6790 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6791 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6792 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6793 totalcma_pages
<< (PAGE_SHIFT
- 10),
6794 #ifdef CONFIG_HIGHMEM
6795 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6797 str
? ", " : "", str
? str
: "");
6801 * set_dma_reserve - set the specified number of pages reserved in the first zone
6802 * @new_dma_reserve: The number of pages to mark reserved
6804 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6805 * In the DMA zone, a significant percentage may be consumed by kernel image
6806 * and other unfreeable allocations which can skew the watermarks badly. This
6807 * function may optionally be used to account for unfreeable pages in the
6808 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6809 * smaller per-cpu batchsize.
6811 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6813 dma_reserve
= new_dma_reserve
;
6816 void __init
free_area_init(unsigned long *zones_size
)
6818 free_area_init_node(0, zones_size
,
6819 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6822 static int page_alloc_cpu_dead(unsigned int cpu
)
6825 lru_add_drain_cpu(cpu
);
6829 * Spill the event counters of the dead processor
6830 * into the current processors event counters.
6831 * This artificially elevates the count of the current
6834 vm_events_fold_cpu(cpu
);
6837 * Zero the differential counters of the dead processor
6838 * so that the vm statistics are consistent.
6840 * This is only okay since the processor is dead and cannot
6841 * race with what we are doing.
6843 cpu_vm_stats_fold(cpu
);
6847 void __init
page_alloc_init(void)
6851 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
6852 "mm/page_alloc:dead", NULL
,
6853 page_alloc_cpu_dead
);
6858 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6859 * or min_free_kbytes changes.
6861 static void calculate_totalreserve_pages(void)
6863 struct pglist_data
*pgdat
;
6864 unsigned long reserve_pages
= 0;
6865 enum zone_type i
, j
;
6867 for_each_online_pgdat(pgdat
) {
6869 pgdat
->totalreserve_pages
= 0;
6871 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6872 struct zone
*zone
= pgdat
->node_zones
+ i
;
6875 /* Find valid and maximum lowmem_reserve in the zone */
6876 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6877 if (zone
->lowmem_reserve
[j
] > max
)
6878 max
= zone
->lowmem_reserve
[j
];
6881 /* we treat the high watermark as reserved pages. */
6882 max
+= high_wmark_pages(zone
);
6884 if (max
> zone
->managed_pages
)
6885 max
= zone
->managed_pages
;
6887 pgdat
->totalreserve_pages
+= max
;
6889 reserve_pages
+= max
;
6892 totalreserve_pages
= reserve_pages
;
6896 * setup_per_zone_lowmem_reserve - called whenever
6897 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6898 * has a correct pages reserved value, so an adequate number of
6899 * pages are left in the zone after a successful __alloc_pages().
6901 static void setup_per_zone_lowmem_reserve(void)
6903 struct pglist_data
*pgdat
;
6904 enum zone_type j
, idx
;
6906 for_each_online_pgdat(pgdat
) {
6907 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6908 struct zone
*zone
= pgdat
->node_zones
+ j
;
6909 unsigned long managed_pages
= zone
->managed_pages
;
6911 zone
->lowmem_reserve
[j
] = 0;
6915 struct zone
*lower_zone
;
6919 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6920 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6922 lower_zone
= pgdat
->node_zones
+ idx
;
6923 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6924 sysctl_lowmem_reserve_ratio
[idx
];
6925 managed_pages
+= lower_zone
->managed_pages
;
6930 /* update totalreserve_pages */
6931 calculate_totalreserve_pages();
6934 static void __setup_per_zone_wmarks(void)
6936 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6937 unsigned long lowmem_pages
= 0;
6939 unsigned long flags
;
6941 /* Calculate total number of !ZONE_HIGHMEM pages */
6942 for_each_zone(zone
) {
6943 if (!is_highmem(zone
))
6944 lowmem_pages
+= zone
->managed_pages
;
6947 for_each_zone(zone
) {
6950 spin_lock_irqsave(&zone
->lock
, flags
);
6951 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6952 do_div(tmp
, lowmem_pages
);
6953 if (is_highmem(zone
)) {
6955 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6956 * need highmem pages, so cap pages_min to a small
6959 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6960 * deltas control asynch page reclaim, and so should
6961 * not be capped for highmem.
6963 unsigned long min_pages
;
6965 min_pages
= zone
->managed_pages
/ 1024;
6966 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6967 zone
->watermark
[WMARK_MIN
] = min_pages
;
6970 * If it's a lowmem zone, reserve a number of pages
6971 * proportionate to the zone's size.
6973 zone
->watermark
[WMARK_MIN
] = tmp
;
6977 * Set the kswapd watermarks distance according to the
6978 * scale factor in proportion to available memory, but
6979 * ensure a minimum size on small systems.
6981 tmp
= max_t(u64
, tmp
>> 2,
6982 mult_frac(zone
->managed_pages
,
6983 watermark_scale_factor
, 10000));
6985 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6986 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6988 spin_unlock_irqrestore(&zone
->lock
, flags
);
6991 /* update totalreserve_pages */
6992 calculate_totalreserve_pages();
6996 * setup_per_zone_wmarks - called when min_free_kbytes changes
6997 * or when memory is hot-{added|removed}
6999 * Ensures that the watermark[min,low,high] values for each zone are set
7000 * correctly with respect to min_free_kbytes.
7002 void setup_per_zone_wmarks(void)
7004 mutex_lock(&zonelists_mutex
);
7005 __setup_per_zone_wmarks();
7006 mutex_unlock(&zonelists_mutex
);
7010 * Initialise min_free_kbytes.
7012 * For small machines we want it small (128k min). For large machines
7013 * we want it large (64MB max). But it is not linear, because network
7014 * bandwidth does not increase linearly with machine size. We use
7016 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7017 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7033 int __meminit
init_per_zone_wmark_min(void)
7035 unsigned long lowmem_kbytes
;
7036 int new_min_free_kbytes
;
7038 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7039 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7041 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7042 min_free_kbytes
= new_min_free_kbytes
;
7043 if (min_free_kbytes
< 128)
7044 min_free_kbytes
= 128;
7045 if (min_free_kbytes
> 65536)
7046 min_free_kbytes
= 65536;
7048 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7049 new_min_free_kbytes
, user_min_free_kbytes
);
7051 setup_per_zone_wmarks();
7052 refresh_zone_stat_thresholds();
7053 setup_per_zone_lowmem_reserve();
7056 setup_min_unmapped_ratio();
7057 setup_min_slab_ratio();
7062 core_initcall(init_per_zone_wmark_min
)
7065 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7066 * that we can call two helper functions whenever min_free_kbytes
7069 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7070 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7074 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7079 user_min_free_kbytes
= min_free_kbytes
;
7080 setup_per_zone_wmarks();
7085 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7086 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7090 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7095 setup_per_zone_wmarks();
7101 static void setup_min_unmapped_ratio(void)
7106 for_each_online_pgdat(pgdat
)
7107 pgdat
->min_unmapped_pages
= 0;
7110 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
7111 sysctl_min_unmapped_ratio
) / 100;
7115 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7116 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7120 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7124 setup_min_unmapped_ratio();
7129 static void setup_min_slab_ratio(void)
7134 for_each_online_pgdat(pgdat
)
7135 pgdat
->min_slab_pages
= 0;
7138 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
7139 sysctl_min_slab_ratio
) / 100;
7142 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7143 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7147 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7151 setup_min_slab_ratio();
7158 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7159 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7160 * whenever sysctl_lowmem_reserve_ratio changes.
7162 * The reserve ratio obviously has absolutely no relation with the
7163 * minimum watermarks. The lowmem reserve ratio can only make sense
7164 * if in function of the boot time zone sizes.
7166 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7167 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7169 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7170 setup_per_zone_lowmem_reserve();
7175 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7176 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7177 * pagelist can have before it gets flushed back to buddy allocator.
7179 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7180 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7183 int old_percpu_pagelist_fraction
;
7186 mutex_lock(&pcp_batch_high_lock
);
7187 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7189 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7190 if (!write
|| ret
< 0)
7193 /* Sanity checking to avoid pcp imbalance */
7194 if (percpu_pagelist_fraction
&&
7195 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7196 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7202 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7205 for_each_populated_zone(zone
) {
7208 for_each_possible_cpu(cpu
)
7209 pageset_set_high_and_batch(zone
,
7210 per_cpu_ptr(zone
->pageset
, cpu
));
7213 mutex_unlock(&pcp_batch_high_lock
);
7218 int hashdist
= HASHDIST_DEFAULT
;
7220 static int __init
set_hashdist(char *str
)
7224 hashdist
= simple_strtoul(str
, &str
, 0);
7227 __setup("hashdist=", set_hashdist
);
7230 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7232 * Returns the number of pages that arch has reserved but
7233 * is not known to alloc_large_system_hash().
7235 static unsigned long __init
arch_reserved_kernel_pages(void)
7242 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7243 * machines. As memory size is increased the scale is also increased but at
7244 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7245 * quadruples the scale is increased by one, which means the size of hash table
7246 * only doubles, instead of quadrupling as well.
7247 * Because 32-bit systems cannot have large physical memory, where this scaling
7248 * makes sense, it is disabled on such platforms.
7250 #if __BITS_PER_LONG > 32
7251 #define ADAPT_SCALE_BASE (64ul << 30)
7252 #define ADAPT_SCALE_SHIFT 2
7253 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7257 * allocate a large system hash table from bootmem
7258 * - it is assumed that the hash table must contain an exact power-of-2
7259 * quantity of entries
7260 * - limit is the number of hash buckets, not the total allocation size
7262 void *__init
alloc_large_system_hash(const char *tablename
,
7263 unsigned long bucketsize
,
7264 unsigned long numentries
,
7267 unsigned int *_hash_shift
,
7268 unsigned int *_hash_mask
,
7269 unsigned long low_limit
,
7270 unsigned long high_limit
)
7272 unsigned long long max
= high_limit
;
7273 unsigned long log2qty
, size
;
7277 /* allow the kernel cmdline to have a say */
7279 /* round applicable memory size up to nearest megabyte */
7280 numentries
= nr_kernel_pages
;
7281 numentries
-= arch_reserved_kernel_pages();
7283 /* It isn't necessary when PAGE_SIZE >= 1MB */
7284 if (PAGE_SHIFT
< 20)
7285 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7287 #if __BITS_PER_LONG > 32
7289 unsigned long adapt
;
7291 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
7292 adapt
<<= ADAPT_SCALE_SHIFT
)
7297 /* limit to 1 bucket per 2^scale bytes of low memory */
7298 if (scale
> PAGE_SHIFT
)
7299 numentries
>>= (scale
- PAGE_SHIFT
);
7301 numentries
<<= (PAGE_SHIFT
- scale
);
7303 /* Make sure we've got at least a 0-order allocation.. */
7304 if (unlikely(flags
& HASH_SMALL
)) {
7305 /* Makes no sense without HASH_EARLY */
7306 WARN_ON(!(flags
& HASH_EARLY
));
7307 if (!(numentries
>> *_hash_shift
)) {
7308 numentries
= 1UL << *_hash_shift
;
7309 BUG_ON(!numentries
);
7311 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7312 numentries
= PAGE_SIZE
/ bucketsize
;
7314 numentries
= roundup_pow_of_two(numentries
);
7316 /* limit allocation size to 1/16 total memory by default */
7318 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7319 do_div(max
, bucketsize
);
7321 max
= min(max
, 0x80000000ULL
);
7323 if (numentries
< low_limit
)
7324 numentries
= low_limit
;
7325 if (numentries
> max
)
7328 log2qty
= ilog2(numentries
);
7331 * memblock allocator returns zeroed memory already, so HASH_ZERO is
7332 * currently not used when HASH_EARLY is specified.
7334 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
7336 size
= bucketsize
<< log2qty
;
7337 if (flags
& HASH_EARLY
)
7338 table
= memblock_virt_alloc_nopanic(size
, 0);
7340 table
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
7343 * If bucketsize is not a power-of-two, we may free
7344 * some pages at the end of hash table which
7345 * alloc_pages_exact() automatically does
7347 if (get_order(size
) < MAX_ORDER
) {
7348 table
= alloc_pages_exact(size
, gfp_flags
);
7349 kmemleak_alloc(table
, size
, 1, gfp_flags
);
7352 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7355 panic("Failed to allocate %s hash table\n", tablename
);
7357 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7358 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7361 *_hash_shift
= log2qty
;
7363 *_hash_mask
= (1 << log2qty
) - 1;
7369 * This function checks whether pageblock includes unmovable pages or not.
7370 * If @count is not zero, it is okay to include less @count unmovable pages
7372 * PageLRU check without isolation or lru_lock could race so that
7373 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7374 * check without lock_page also may miss some movable non-lru pages at
7375 * race condition. So you can't expect this function should be exact.
7377 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7378 bool skip_hwpoisoned_pages
)
7380 unsigned long pfn
, iter
, found
;
7384 * For avoiding noise data, lru_add_drain_all() should be called
7385 * If ZONE_MOVABLE, the zone never contains unmovable pages
7387 if (zone_idx(zone
) == ZONE_MOVABLE
)
7389 mt
= get_pageblock_migratetype(page
);
7390 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
7393 pfn
= page_to_pfn(page
);
7394 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7395 unsigned long check
= pfn
+ iter
;
7397 if (!pfn_valid_within(check
))
7400 page
= pfn_to_page(check
);
7403 * Hugepages are not in LRU lists, but they're movable.
7404 * We need not scan over tail pages bacause we don't
7405 * handle each tail page individually in migration.
7407 if (PageHuge(page
)) {
7408 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7413 * We can't use page_count without pin a page
7414 * because another CPU can free compound page.
7415 * This check already skips compound tails of THP
7416 * because their page->_refcount is zero at all time.
7418 if (!page_ref_count(page
)) {
7419 if (PageBuddy(page
))
7420 iter
+= (1 << page_order(page
)) - 1;
7425 * The HWPoisoned page may be not in buddy system, and
7426 * page_count() is not 0.
7428 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7431 if (__PageMovable(page
))
7437 * If there are RECLAIMABLE pages, we need to check
7438 * it. But now, memory offline itself doesn't call
7439 * shrink_node_slabs() and it still to be fixed.
7442 * If the page is not RAM, page_count()should be 0.
7443 * we don't need more check. This is an _used_ not-movable page.
7445 * The problematic thing here is PG_reserved pages. PG_reserved
7446 * is set to both of a memory hole page and a _used_ kernel
7455 bool is_pageblock_removable_nolock(struct page
*page
)
7461 * We have to be careful here because we are iterating over memory
7462 * sections which are not zone aware so we might end up outside of
7463 * the zone but still within the section.
7464 * We have to take care about the node as well. If the node is offline
7465 * its NODE_DATA will be NULL - see page_zone.
7467 if (!node_online(page_to_nid(page
)))
7470 zone
= page_zone(page
);
7471 pfn
= page_to_pfn(page
);
7472 if (!zone_spans_pfn(zone
, pfn
))
7475 return !has_unmovable_pages(zone
, page
, 0, true);
7478 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7480 static unsigned long pfn_max_align_down(unsigned long pfn
)
7482 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7483 pageblock_nr_pages
) - 1);
7486 static unsigned long pfn_max_align_up(unsigned long pfn
)
7488 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7489 pageblock_nr_pages
));
7492 /* [start, end) must belong to a single zone. */
7493 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7494 unsigned long start
, unsigned long end
)
7496 /* This function is based on compact_zone() from compaction.c. */
7497 unsigned long nr_reclaimed
;
7498 unsigned long pfn
= start
;
7499 unsigned int tries
= 0;
7504 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7505 if (fatal_signal_pending(current
)) {
7510 if (list_empty(&cc
->migratepages
)) {
7511 cc
->nr_migratepages
= 0;
7512 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7518 } else if (++tries
== 5) {
7519 ret
= ret
< 0 ? ret
: -EBUSY
;
7523 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7525 cc
->nr_migratepages
-= nr_reclaimed
;
7527 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7528 NULL
, 0, cc
->mode
, MR_CMA
);
7531 putback_movable_pages(&cc
->migratepages
);
7538 * alloc_contig_range() -- tries to allocate given range of pages
7539 * @start: start PFN to allocate
7540 * @end: one-past-the-last PFN to allocate
7541 * @migratetype: migratetype of the underlaying pageblocks (either
7542 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7543 * in range must have the same migratetype and it must
7544 * be either of the two.
7545 * @gfp_mask: GFP mask to use during compaction
7547 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7548 * aligned, however it's the caller's responsibility to guarantee that
7549 * we are the only thread that changes migrate type of pageblocks the
7552 * The PFN range must belong to a single zone.
7554 * Returns zero on success or negative error code. On success all
7555 * pages which PFN is in [start, end) are allocated for the caller and
7556 * need to be freed with free_contig_range().
7558 int alloc_contig_range(unsigned long start
, unsigned long end
,
7559 unsigned migratetype
, gfp_t gfp_mask
)
7561 unsigned long outer_start
, outer_end
;
7565 struct compact_control cc
= {
7566 .nr_migratepages
= 0,
7568 .zone
= page_zone(pfn_to_page(start
)),
7569 .mode
= MIGRATE_SYNC
,
7570 .ignore_skip_hint
= true,
7571 .gfp_mask
= current_gfp_context(gfp_mask
),
7573 INIT_LIST_HEAD(&cc
.migratepages
);
7576 * What we do here is we mark all pageblocks in range as
7577 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7578 * have different sizes, and due to the way page allocator
7579 * work, we align the range to biggest of the two pages so
7580 * that page allocator won't try to merge buddies from
7581 * different pageblocks and change MIGRATE_ISOLATE to some
7582 * other migration type.
7584 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7585 * migrate the pages from an unaligned range (ie. pages that
7586 * we are interested in). This will put all the pages in
7587 * range back to page allocator as MIGRATE_ISOLATE.
7589 * When this is done, we take the pages in range from page
7590 * allocator removing them from the buddy system. This way
7591 * page allocator will never consider using them.
7593 * This lets us mark the pageblocks back as
7594 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7595 * aligned range but not in the unaligned, original range are
7596 * put back to page allocator so that buddy can use them.
7599 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7600 pfn_max_align_up(end
), migratetype
,
7606 * In case of -EBUSY, we'd like to know which page causes problem.
7607 * So, just fall through. We will check it in test_pages_isolated().
7609 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7610 if (ret
&& ret
!= -EBUSY
)
7614 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7615 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7616 * more, all pages in [start, end) are free in page allocator.
7617 * What we are going to do is to allocate all pages from
7618 * [start, end) (that is remove them from page allocator).
7620 * The only problem is that pages at the beginning and at the
7621 * end of interesting range may be not aligned with pages that
7622 * page allocator holds, ie. they can be part of higher order
7623 * pages. Because of this, we reserve the bigger range and
7624 * once this is done free the pages we are not interested in.
7626 * We don't have to hold zone->lock here because the pages are
7627 * isolated thus they won't get removed from buddy.
7630 lru_add_drain_all();
7631 drain_all_pages(cc
.zone
);
7634 outer_start
= start
;
7635 while (!PageBuddy(pfn_to_page(outer_start
))) {
7636 if (++order
>= MAX_ORDER
) {
7637 outer_start
= start
;
7640 outer_start
&= ~0UL << order
;
7643 if (outer_start
!= start
) {
7644 order
= page_order(pfn_to_page(outer_start
));
7647 * outer_start page could be small order buddy page and
7648 * it doesn't include start page. Adjust outer_start
7649 * in this case to report failed page properly
7650 * on tracepoint in test_pages_isolated()
7652 if (outer_start
+ (1UL << order
) <= start
)
7653 outer_start
= start
;
7656 /* Make sure the range is really isolated. */
7657 if (test_pages_isolated(outer_start
, end
, false)) {
7658 pr_info("%s: [%lx, %lx) PFNs busy\n",
7659 __func__
, outer_start
, end
);
7664 /* Grab isolated pages from freelists. */
7665 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7671 /* Free head and tail (if any) */
7672 if (start
!= outer_start
)
7673 free_contig_range(outer_start
, start
- outer_start
);
7674 if (end
!= outer_end
)
7675 free_contig_range(end
, outer_end
- end
);
7678 undo_isolate_page_range(pfn_max_align_down(start
),
7679 pfn_max_align_up(end
), migratetype
);
7683 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7685 unsigned int count
= 0;
7687 for (; nr_pages
--; pfn
++) {
7688 struct page
*page
= pfn_to_page(pfn
);
7690 count
+= page_count(page
) != 1;
7693 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7697 #ifdef CONFIG_MEMORY_HOTPLUG
7699 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7700 * page high values need to be recalulated.
7702 void __meminit
zone_pcp_update(struct zone
*zone
)
7705 mutex_lock(&pcp_batch_high_lock
);
7706 for_each_possible_cpu(cpu
)
7707 pageset_set_high_and_batch(zone
,
7708 per_cpu_ptr(zone
->pageset
, cpu
));
7709 mutex_unlock(&pcp_batch_high_lock
);
7713 void zone_pcp_reset(struct zone
*zone
)
7715 unsigned long flags
;
7717 struct per_cpu_pageset
*pset
;
7719 /* avoid races with drain_pages() */
7720 local_irq_save(flags
);
7721 if (zone
->pageset
!= &boot_pageset
) {
7722 for_each_online_cpu(cpu
) {
7723 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7724 drain_zonestat(zone
, pset
);
7726 free_percpu(zone
->pageset
);
7727 zone
->pageset
= &boot_pageset
;
7729 local_irq_restore(flags
);
7732 #ifdef CONFIG_MEMORY_HOTREMOVE
7734 * All pages in the range must be in a single zone and isolated
7735 * before calling this.
7738 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7742 unsigned int order
, i
;
7744 unsigned long flags
;
7745 /* find the first valid pfn */
7746 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7751 offline_mem_sections(pfn
, end_pfn
);
7752 zone
= page_zone(pfn_to_page(pfn
));
7753 spin_lock_irqsave(&zone
->lock
, flags
);
7755 while (pfn
< end_pfn
) {
7756 if (!pfn_valid(pfn
)) {
7760 page
= pfn_to_page(pfn
);
7762 * The HWPoisoned page may be not in buddy system, and
7763 * page_count() is not 0.
7765 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7767 SetPageReserved(page
);
7771 BUG_ON(page_count(page
));
7772 BUG_ON(!PageBuddy(page
));
7773 order
= page_order(page
);
7774 #ifdef CONFIG_DEBUG_VM
7775 pr_info("remove from free list %lx %d %lx\n",
7776 pfn
, 1 << order
, end_pfn
);
7778 list_del(&page
->lru
);
7779 rmv_page_order(page
);
7780 zone
->free_area
[order
].nr_free
--;
7781 for (i
= 0; i
< (1 << order
); i
++)
7782 SetPageReserved((page
+i
));
7783 pfn
+= (1 << order
);
7785 spin_unlock_irqrestore(&zone
->lock
, flags
);
7789 bool is_free_buddy_page(struct page
*page
)
7791 struct zone
*zone
= page_zone(page
);
7792 unsigned long pfn
= page_to_pfn(page
);
7793 unsigned long flags
;
7796 spin_lock_irqsave(&zone
->lock
, flags
);
7797 for (order
= 0; order
< MAX_ORDER
; order
++) {
7798 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7800 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7803 spin_unlock_irqrestore(&zone
->lock
, flags
);
7805 return order
< MAX_ORDER
;