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/kasan.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/memremap.h>
46 #include <linux/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <trace/events/oom.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/sched/mm.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66 #include <linux/memcontrol.h>
67 #include <linux/ftrace.h>
68 #include <linux/lockdep.h>
69 #include <linux/nmi.h>
71 #include <asm/sections.h>
72 #include <asm/tlbflush.h>
73 #include <asm/div64.h>
76 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
77 static DEFINE_MUTEX(pcp_batch_high_lock
);
78 #define MIN_PERCPU_PAGELIST_FRACTION (8)
80 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
81 DEFINE_PER_CPU(int, numa_node
);
82 EXPORT_PER_CPU_SYMBOL(numa_node
);
85 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
87 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
89 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
90 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
91 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
92 * defined in <linux/topology.h>.
94 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
95 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
96 int _node_numa_mem_
[MAX_NUMNODES
];
99 /* work_structs for global per-cpu drains */
100 DEFINE_MUTEX(pcpu_drain_mutex
);
101 DEFINE_PER_CPU(struct work_struct
, pcpu_drain
);
103 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
104 volatile unsigned long latent_entropy __latent_entropy
;
105 EXPORT_SYMBOL(latent_entropy
);
109 * Array of node states.
111 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
112 [N_POSSIBLE
] = NODE_MASK_ALL
,
113 [N_ONLINE
] = { { [0] = 1UL } },
115 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
116 #ifdef CONFIG_HIGHMEM
117 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
119 [N_MEMORY
] = { { [0] = 1UL } },
120 [N_CPU
] = { { [0] = 1UL } },
123 EXPORT_SYMBOL(node_states
);
125 /* Protect totalram_pages and zone->managed_pages */
126 static DEFINE_SPINLOCK(managed_page_count_lock
);
128 unsigned long totalram_pages __read_mostly
;
129 unsigned long totalreserve_pages __read_mostly
;
130 unsigned long totalcma_pages __read_mostly
;
132 int percpu_pagelist_fraction
;
133 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
136 * A cached value of the page's pageblock's migratetype, used when the page is
137 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
138 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
139 * Also the migratetype set in the page does not necessarily match the pcplist
140 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
141 * other index - this ensures that it will be put on the correct CMA freelist.
143 static inline int get_pcppage_migratetype(struct page
*page
)
148 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
150 page
->index
= migratetype
;
153 #ifdef CONFIG_PM_SLEEP
155 * The following functions are used by the suspend/hibernate code to temporarily
156 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
157 * while devices are suspended. To avoid races with the suspend/hibernate code,
158 * they should always be called with pm_mutex held (gfp_allowed_mask also should
159 * only be modified with pm_mutex held, unless the suspend/hibernate code is
160 * guaranteed not to run in parallel with that modification).
163 static gfp_t saved_gfp_mask
;
165 void pm_restore_gfp_mask(void)
167 WARN_ON(!mutex_is_locked(&pm_mutex
));
168 if (saved_gfp_mask
) {
169 gfp_allowed_mask
= saved_gfp_mask
;
174 void pm_restrict_gfp_mask(void)
176 WARN_ON(!mutex_is_locked(&pm_mutex
));
177 WARN_ON(saved_gfp_mask
);
178 saved_gfp_mask
= gfp_allowed_mask
;
179 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
182 bool pm_suspended_storage(void)
184 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
188 #endif /* CONFIG_PM_SLEEP */
190 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
191 unsigned int pageblock_order __read_mostly
;
194 static void __free_pages_ok(struct page
*page
, unsigned int order
);
197 * results with 256, 32 in the lowmem_reserve sysctl:
198 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
199 * 1G machine -> (16M dma, 784M normal, 224M high)
200 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
201 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
202 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
204 * TBD: should special case ZONE_DMA32 machines here - in those we normally
205 * don't need any ZONE_NORMAL reservation
207 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
208 #ifdef CONFIG_ZONE_DMA
211 #ifdef CONFIG_ZONE_DMA32
214 #ifdef CONFIG_HIGHMEM
220 EXPORT_SYMBOL(totalram_pages
);
222 static char * const zone_names
[MAX_NR_ZONES
] = {
223 #ifdef CONFIG_ZONE_DMA
226 #ifdef CONFIG_ZONE_DMA32
230 #ifdef CONFIG_HIGHMEM
234 #ifdef CONFIG_ZONE_DEVICE
239 char * const migratetype_names
[MIGRATE_TYPES
] = {
247 #ifdef CONFIG_MEMORY_ISOLATION
252 compound_page_dtor
* const compound_page_dtors
[] = {
255 #ifdef CONFIG_HUGETLB_PAGE
258 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
263 int min_free_kbytes
= 1024;
264 int user_min_free_kbytes
= -1;
265 int watermark_scale_factor
= 10;
267 static unsigned long __meminitdata nr_kernel_pages
;
268 static unsigned long __meminitdata nr_all_pages
;
269 static unsigned long __meminitdata dma_reserve
;
271 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
272 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
273 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
274 static unsigned long __initdata required_kernelcore
;
275 static unsigned long __initdata required_movablecore
;
276 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
277 static bool mirrored_kernelcore
;
279 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
281 EXPORT_SYMBOL(movable_zone
);
282 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
285 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
286 int nr_online_nodes __read_mostly
= 1;
287 EXPORT_SYMBOL(nr_node_ids
);
288 EXPORT_SYMBOL(nr_online_nodes
);
291 int page_group_by_mobility_disabled __read_mostly
;
293 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
296 * Determine how many pages need to be initialized durig early boot
297 * (non-deferred initialization).
298 * The value of first_deferred_pfn will be set later, once non-deferred pages
299 * are initialized, but for now set it ULONG_MAX.
301 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
303 phys_addr_t start_addr
, end_addr
;
304 unsigned long max_pgcnt
;
305 unsigned long reserved
;
308 * Initialise at least 2G of a node but also take into account that
309 * two large system hashes that can take up 1GB for 0.25TB/node.
311 max_pgcnt
= max(2UL << (30 - PAGE_SHIFT
),
312 (pgdat
->node_spanned_pages
>> 8));
315 * Compensate the all the memblock reservations (e.g. crash kernel)
316 * from the initial estimation to make sure we will initialize enough
319 start_addr
= PFN_PHYS(pgdat
->node_start_pfn
);
320 end_addr
= PFN_PHYS(pgdat
->node_start_pfn
+ max_pgcnt
);
321 reserved
= memblock_reserved_memory_within(start_addr
, end_addr
);
322 max_pgcnt
+= PHYS_PFN(reserved
);
324 pgdat
->static_init_pgcnt
= min(max_pgcnt
, pgdat
->node_spanned_pages
);
325 pgdat
->first_deferred_pfn
= ULONG_MAX
;
328 /* Returns true if the struct page for the pfn is uninitialised */
329 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
331 int nid
= early_pfn_to_nid(pfn
);
333 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
340 * Returns false when the remaining initialisation should be deferred until
341 * later in the boot cycle when it can be parallelised.
343 static inline bool update_defer_init(pg_data_t
*pgdat
,
344 unsigned long pfn
, unsigned long zone_end
,
345 unsigned long *nr_initialised
)
347 /* Always populate low zones for address-contrained allocations */
348 if (zone_end
< pgdat_end_pfn(pgdat
))
351 if ((*nr_initialised
> pgdat
->static_init_pgcnt
) &&
352 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
353 pgdat
->first_deferred_pfn
= pfn
;
360 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
364 static inline bool early_page_uninitialised(unsigned long pfn
)
369 static inline bool update_defer_init(pg_data_t
*pgdat
,
370 unsigned long pfn
, unsigned long zone_end
,
371 unsigned long *nr_initialised
)
377 /* Return a pointer to the bitmap storing bits affecting a block of pages */
378 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
381 #ifdef CONFIG_SPARSEMEM
382 return __pfn_to_section(pfn
)->pageblock_flags
;
384 return page_zone(page
)->pageblock_flags
;
385 #endif /* CONFIG_SPARSEMEM */
388 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
390 #ifdef CONFIG_SPARSEMEM
391 pfn
&= (PAGES_PER_SECTION
-1);
392 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
394 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
395 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
396 #endif /* CONFIG_SPARSEMEM */
400 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
401 * @page: The page within the block of interest
402 * @pfn: The target page frame number
403 * @end_bitidx: The last bit of interest to retrieve
404 * @mask: mask of bits that the caller is interested in
406 * Return: pageblock_bits flags
408 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
410 unsigned long end_bitidx
,
413 unsigned long *bitmap
;
414 unsigned long bitidx
, word_bitidx
;
417 bitmap
= get_pageblock_bitmap(page
, pfn
);
418 bitidx
= pfn_to_bitidx(page
, pfn
);
419 word_bitidx
= bitidx
/ BITS_PER_LONG
;
420 bitidx
&= (BITS_PER_LONG
-1);
422 word
= bitmap
[word_bitidx
];
423 bitidx
+= end_bitidx
;
424 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
427 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
428 unsigned long end_bitidx
,
431 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
434 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
436 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
440 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
441 * @page: The page within the block of interest
442 * @flags: The flags to set
443 * @pfn: The target page frame number
444 * @end_bitidx: The last bit of interest
445 * @mask: mask of bits that the caller is interested in
447 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
449 unsigned long end_bitidx
,
452 unsigned long *bitmap
;
453 unsigned long bitidx
, word_bitidx
;
454 unsigned long old_word
, word
;
456 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
458 bitmap
= get_pageblock_bitmap(page
, pfn
);
459 bitidx
= pfn_to_bitidx(page
, pfn
);
460 word_bitidx
= bitidx
/ BITS_PER_LONG
;
461 bitidx
&= (BITS_PER_LONG
-1);
463 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
465 bitidx
+= end_bitidx
;
466 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
467 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
469 word
= READ_ONCE(bitmap
[word_bitidx
]);
471 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
472 if (word
== old_word
)
478 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
480 if (unlikely(page_group_by_mobility_disabled
&&
481 migratetype
< MIGRATE_PCPTYPES
))
482 migratetype
= MIGRATE_UNMOVABLE
;
484 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
485 PB_migrate
, PB_migrate_end
);
488 #ifdef CONFIG_DEBUG_VM
489 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
493 unsigned long pfn
= page_to_pfn(page
);
494 unsigned long sp
, start_pfn
;
497 seq
= zone_span_seqbegin(zone
);
498 start_pfn
= zone
->zone_start_pfn
;
499 sp
= zone
->spanned_pages
;
500 if (!zone_spans_pfn(zone
, pfn
))
502 } while (zone_span_seqretry(zone
, seq
));
505 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
506 pfn
, zone_to_nid(zone
), zone
->name
,
507 start_pfn
, start_pfn
+ sp
);
512 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
514 if (!pfn_valid_within(page_to_pfn(page
)))
516 if (zone
!= page_zone(page
))
522 * Temporary debugging check for pages not lying within a given zone.
524 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
526 if (page_outside_zone_boundaries(zone
, page
))
528 if (!page_is_consistent(zone
, page
))
534 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
540 static void bad_page(struct page
*page
, const char *reason
,
541 unsigned long bad_flags
)
543 static unsigned long resume
;
544 static unsigned long nr_shown
;
545 static unsigned long nr_unshown
;
548 * Allow a burst of 60 reports, then keep quiet for that minute;
549 * or allow a steady drip of one report per second.
551 if (nr_shown
== 60) {
552 if (time_before(jiffies
, resume
)) {
558 "BUG: Bad page state: %lu messages suppressed\n",
565 resume
= jiffies
+ 60 * HZ
;
567 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
568 current
->comm
, page_to_pfn(page
));
569 __dump_page(page
, reason
);
570 bad_flags
&= page
->flags
;
572 pr_alert("bad because of flags: %#lx(%pGp)\n",
573 bad_flags
, &bad_flags
);
574 dump_page_owner(page
);
579 /* Leave bad fields for debug, except PageBuddy could make trouble */
580 page_mapcount_reset(page
); /* remove PageBuddy */
581 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
585 * Higher-order pages are called "compound pages". They are structured thusly:
587 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
589 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
590 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
592 * The first tail page's ->compound_dtor holds the offset in array of compound
593 * page destructors. See compound_page_dtors.
595 * The first tail page's ->compound_order holds the order of allocation.
596 * This usage means that zero-order pages may not be compound.
599 void free_compound_page(struct page
*page
)
601 __free_pages_ok(page
, compound_order(page
));
604 void prep_compound_page(struct page
*page
, unsigned int order
)
607 int nr_pages
= 1 << order
;
609 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
610 set_compound_order(page
, order
);
612 for (i
= 1; i
< nr_pages
; i
++) {
613 struct page
*p
= page
+ i
;
614 set_page_count(p
, 0);
615 p
->mapping
= TAIL_MAPPING
;
616 set_compound_head(p
, page
);
618 atomic_set(compound_mapcount_ptr(page
), -1);
621 #ifdef CONFIG_DEBUG_PAGEALLOC
622 unsigned int _debug_guardpage_minorder
;
623 bool _debug_pagealloc_enabled __read_mostly
624 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
625 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
626 bool _debug_guardpage_enabled __read_mostly
;
628 static int __init
early_debug_pagealloc(char *buf
)
632 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
634 early_param("debug_pagealloc", early_debug_pagealloc
);
636 static bool need_debug_guardpage(void)
638 /* If we don't use debug_pagealloc, we don't need guard page */
639 if (!debug_pagealloc_enabled())
642 if (!debug_guardpage_minorder())
648 static void init_debug_guardpage(void)
650 if (!debug_pagealloc_enabled())
653 if (!debug_guardpage_minorder())
656 _debug_guardpage_enabled
= true;
659 struct page_ext_operations debug_guardpage_ops
= {
660 .need
= need_debug_guardpage
,
661 .init
= init_debug_guardpage
,
664 static int __init
debug_guardpage_minorder_setup(char *buf
)
668 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
669 pr_err("Bad debug_guardpage_minorder value\n");
672 _debug_guardpage_minorder
= res
;
673 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
676 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
678 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
679 unsigned int order
, int migratetype
)
681 struct page_ext
*page_ext
;
683 if (!debug_guardpage_enabled())
686 if (order
>= debug_guardpage_minorder())
689 page_ext
= lookup_page_ext(page
);
690 if (unlikely(!page_ext
))
693 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
695 INIT_LIST_HEAD(&page
->lru
);
696 set_page_private(page
, order
);
697 /* Guard pages are not available for any usage */
698 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
703 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
704 unsigned int order
, int migratetype
)
706 struct page_ext
*page_ext
;
708 if (!debug_guardpage_enabled())
711 page_ext
= lookup_page_ext(page
);
712 if (unlikely(!page_ext
))
715 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
717 set_page_private(page
, 0);
718 if (!is_migrate_isolate(migratetype
))
719 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
722 struct page_ext_operations debug_guardpage_ops
;
723 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
724 unsigned int order
, int migratetype
) { return false; }
725 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
726 unsigned int order
, int migratetype
) {}
729 static inline void set_page_order(struct page
*page
, unsigned int order
)
731 set_page_private(page
, order
);
732 __SetPageBuddy(page
);
735 static inline void rmv_page_order(struct page
*page
)
737 __ClearPageBuddy(page
);
738 set_page_private(page
, 0);
742 * This function checks whether a page is free && is the buddy
743 * we can do coalesce a page and its buddy if
744 * (a) the buddy is not in a hole (check before calling!) &&
745 * (b) the buddy is in the buddy system &&
746 * (c) a page and its buddy have the same order &&
747 * (d) a page and its buddy are in the same zone.
749 * For recording whether a page is in the buddy system, we set ->_mapcount
750 * PAGE_BUDDY_MAPCOUNT_VALUE.
751 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
752 * serialized by zone->lock.
754 * For recording page's order, we use page_private(page).
756 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
759 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
760 if (page_zone_id(page
) != page_zone_id(buddy
))
763 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
768 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
770 * zone check is done late to avoid uselessly
771 * calculating zone/node ids for pages that could
774 if (page_zone_id(page
) != page_zone_id(buddy
))
777 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
785 * Freeing function for a buddy system allocator.
787 * The concept of a buddy system is to maintain direct-mapped table
788 * (containing bit values) for memory blocks of various "orders".
789 * The bottom level table contains the map for the smallest allocatable
790 * units of memory (here, pages), and each level above it describes
791 * pairs of units from the levels below, hence, "buddies".
792 * At a high level, all that happens here is marking the table entry
793 * at the bottom level available, and propagating the changes upward
794 * as necessary, plus some accounting needed to play nicely with other
795 * parts of the VM system.
796 * At each level, we keep a list of pages, which are heads of continuous
797 * free pages of length of (1 << order) and marked with _mapcount
798 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
800 * So when we are allocating or freeing one, we can derive the state of the
801 * other. That is, if we allocate a small block, and both were
802 * free, the remainder of the region must be split into blocks.
803 * If a block is freed, and its buddy is also free, then this
804 * triggers coalescing into a block of larger size.
809 static inline void __free_one_page(struct page
*page
,
811 struct zone
*zone
, unsigned int order
,
814 unsigned long combined_pfn
;
815 unsigned long uninitialized_var(buddy_pfn
);
817 unsigned int max_order
;
819 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
821 VM_BUG_ON(!zone_is_initialized(zone
));
822 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
824 VM_BUG_ON(migratetype
== -1);
825 if (likely(!is_migrate_isolate(migratetype
)))
826 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
828 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
829 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
832 while (order
< max_order
- 1) {
833 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
834 buddy
= page
+ (buddy_pfn
- pfn
);
836 if (!pfn_valid_within(buddy_pfn
))
838 if (!page_is_buddy(page
, buddy
, order
))
841 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
842 * merge with it and move up one order.
844 if (page_is_guard(buddy
)) {
845 clear_page_guard(zone
, buddy
, order
, migratetype
);
847 list_del(&buddy
->lru
);
848 zone
->free_area
[order
].nr_free
--;
849 rmv_page_order(buddy
);
851 combined_pfn
= buddy_pfn
& pfn
;
852 page
= page
+ (combined_pfn
- pfn
);
856 if (max_order
< MAX_ORDER
) {
857 /* If we are here, it means order is >= pageblock_order.
858 * We want to prevent merge between freepages on isolate
859 * pageblock and normal pageblock. Without this, pageblock
860 * isolation could cause incorrect freepage or CMA accounting.
862 * We don't want to hit this code for the more frequent
865 if (unlikely(has_isolate_pageblock(zone
))) {
868 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
869 buddy
= page
+ (buddy_pfn
- pfn
);
870 buddy_mt
= get_pageblock_migratetype(buddy
);
872 if (migratetype
!= buddy_mt
873 && (is_migrate_isolate(migratetype
) ||
874 is_migrate_isolate(buddy_mt
)))
878 goto continue_merging
;
882 set_page_order(page
, order
);
885 * If this is not the largest possible page, check if the buddy
886 * of the next-highest order is free. If it is, it's possible
887 * that pages are being freed that will coalesce soon. In case,
888 * that is happening, add the free page to the tail of the list
889 * so it's less likely to be used soon and more likely to be merged
890 * as a higher order page
892 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)) {
893 struct page
*higher_page
, *higher_buddy
;
894 combined_pfn
= buddy_pfn
& pfn
;
895 higher_page
= page
+ (combined_pfn
- pfn
);
896 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
897 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
898 if (pfn_valid_within(buddy_pfn
) &&
899 page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
900 list_add_tail(&page
->lru
,
901 &zone
->free_area
[order
].free_list
[migratetype
]);
906 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
908 zone
->free_area
[order
].nr_free
++;
912 * A bad page could be due to a number of fields. Instead of multiple branches,
913 * try and check multiple fields with one check. The caller must do a detailed
914 * check if necessary.
916 static inline bool page_expected_state(struct page
*page
,
917 unsigned long check_flags
)
919 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
922 if (unlikely((unsigned long)page
->mapping
|
923 page_ref_count(page
) |
925 (unsigned long)page
->mem_cgroup
|
927 (page
->flags
& check_flags
)))
933 static void free_pages_check_bad(struct page
*page
)
935 const char *bad_reason
;
936 unsigned long bad_flags
;
941 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
942 bad_reason
= "nonzero mapcount";
943 if (unlikely(page
->mapping
!= NULL
))
944 bad_reason
= "non-NULL mapping";
945 if (unlikely(page_ref_count(page
) != 0))
946 bad_reason
= "nonzero _refcount";
947 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
948 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
949 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
952 if (unlikely(page
->mem_cgroup
))
953 bad_reason
= "page still charged to cgroup";
955 bad_page(page
, bad_reason
, bad_flags
);
958 static inline int free_pages_check(struct page
*page
)
960 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
963 /* Something has gone sideways, find it */
964 free_pages_check_bad(page
);
968 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
973 * We rely page->lru.next never has bit 0 set, unless the page
974 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
976 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
978 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
982 switch (page
- head_page
) {
984 /* the first tail page: ->mapping is compound_mapcount() */
985 if (unlikely(compound_mapcount(page
))) {
986 bad_page(page
, "nonzero compound_mapcount", 0);
992 * the second tail page: ->mapping is
993 * page_deferred_list().next -- ignore value.
997 if (page
->mapping
!= TAIL_MAPPING
) {
998 bad_page(page
, "corrupted mapping in tail page", 0);
1003 if (unlikely(!PageTail(page
))) {
1004 bad_page(page
, "PageTail not set", 0);
1007 if (unlikely(compound_head(page
) != head_page
)) {
1008 bad_page(page
, "compound_head not consistent", 0);
1013 page
->mapping
= NULL
;
1014 clear_compound_head(page
);
1018 static __always_inline
bool free_pages_prepare(struct page
*page
,
1019 unsigned int order
, bool check_free
)
1023 VM_BUG_ON_PAGE(PageTail(page
), page
);
1025 trace_mm_page_free(page
, order
);
1028 * Check tail pages before head page information is cleared to
1029 * avoid checking PageCompound for order-0 pages.
1031 if (unlikely(order
)) {
1032 bool compound
= PageCompound(page
);
1035 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1038 ClearPageDoubleMap(page
);
1039 for (i
= 1; i
< (1 << order
); i
++) {
1041 bad
+= free_tail_pages_check(page
, page
+ i
);
1042 if (unlikely(free_pages_check(page
+ i
))) {
1046 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1049 if (PageMappingFlags(page
))
1050 page
->mapping
= NULL
;
1051 if (memcg_kmem_enabled() && PageKmemcg(page
))
1052 memcg_kmem_uncharge(page
, order
);
1054 bad
+= free_pages_check(page
);
1058 page_cpupid_reset_last(page
);
1059 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1060 reset_page_owner(page
, order
);
1062 if (!PageHighMem(page
)) {
1063 debug_check_no_locks_freed(page_address(page
),
1064 PAGE_SIZE
<< order
);
1065 debug_check_no_obj_freed(page_address(page
),
1066 PAGE_SIZE
<< order
);
1068 arch_free_page(page
, order
);
1069 kernel_poison_pages(page
, 1 << order
, 0);
1070 kernel_map_pages(page
, 1 << order
, 0);
1071 kasan_free_pages(page
, order
);
1076 #ifdef CONFIG_DEBUG_VM
1077 static inline bool free_pcp_prepare(struct page
*page
)
1079 return free_pages_prepare(page
, 0, true);
1082 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1087 static bool free_pcp_prepare(struct page
*page
)
1089 return free_pages_prepare(page
, 0, false);
1092 static bool bulkfree_pcp_prepare(struct page
*page
)
1094 return free_pages_check(page
);
1096 #endif /* CONFIG_DEBUG_VM */
1099 * Frees a number of pages from the PCP lists
1100 * Assumes all pages on list are in same zone, and of same order.
1101 * count is the number of pages to free.
1103 * If the zone was previously in an "all pages pinned" state then look to
1104 * see if this freeing clears that state.
1106 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1107 * pinned" detection logic.
1109 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1110 struct per_cpu_pages
*pcp
)
1112 int migratetype
= 0;
1114 bool isolated_pageblocks
;
1116 spin_lock(&zone
->lock
);
1117 isolated_pageblocks
= has_isolate_pageblock(zone
);
1121 struct list_head
*list
;
1124 * Remove pages from lists in a round-robin fashion. A
1125 * batch_free count is maintained that is incremented when an
1126 * empty list is encountered. This is so more pages are freed
1127 * off fuller lists instead of spinning excessively around empty
1132 if (++migratetype
== MIGRATE_PCPTYPES
)
1134 list
= &pcp
->lists
[migratetype
];
1135 } while (list_empty(list
));
1137 /* This is the only non-empty list. Free them all. */
1138 if (batch_free
== MIGRATE_PCPTYPES
)
1142 int mt
; /* migratetype of the to-be-freed page */
1144 page
= list_last_entry(list
, struct page
, lru
);
1145 /* must delete as __free_one_page list manipulates */
1146 list_del(&page
->lru
);
1148 mt
= get_pcppage_migratetype(page
);
1149 /* MIGRATE_ISOLATE page should not go to pcplists */
1150 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1151 /* Pageblock could have been isolated meanwhile */
1152 if (unlikely(isolated_pageblocks
))
1153 mt
= get_pageblock_migratetype(page
);
1155 if (bulkfree_pcp_prepare(page
))
1158 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1159 trace_mm_page_pcpu_drain(page
, 0, mt
);
1160 } while (--count
&& --batch_free
&& !list_empty(list
));
1162 spin_unlock(&zone
->lock
);
1165 static void free_one_page(struct zone
*zone
,
1166 struct page
*page
, unsigned long pfn
,
1170 spin_lock(&zone
->lock
);
1171 if (unlikely(has_isolate_pageblock(zone
) ||
1172 is_migrate_isolate(migratetype
))) {
1173 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1175 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1176 spin_unlock(&zone
->lock
);
1179 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1180 unsigned long zone
, int nid
)
1182 mm_zero_struct_page(page
);
1183 set_page_links(page
, zone
, nid
, pfn
);
1184 init_page_count(page
);
1185 page_mapcount_reset(page
);
1186 page_cpupid_reset_last(page
);
1188 INIT_LIST_HEAD(&page
->lru
);
1189 #ifdef WANT_PAGE_VIRTUAL
1190 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1191 if (!is_highmem_idx(zone
))
1192 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1196 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1199 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
1202 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1203 static void __meminit
init_reserved_page(unsigned long pfn
)
1208 if (!early_page_uninitialised(pfn
))
1211 nid
= early_pfn_to_nid(pfn
);
1212 pgdat
= NODE_DATA(nid
);
1214 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1215 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1217 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1220 __init_single_pfn(pfn
, zid
, nid
);
1223 static inline void init_reserved_page(unsigned long pfn
)
1226 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1229 * Initialised pages do not have PageReserved set. This function is
1230 * called for each range allocated by the bootmem allocator and
1231 * marks the pages PageReserved. The remaining valid pages are later
1232 * sent to the buddy page allocator.
1234 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1236 unsigned long start_pfn
= PFN_DOWN(start
);
1237 unsigned long end_pfn
= PFN_UP(end
);
1239 for (; start_pfn
< end_pfn
; start_pfn
++) {
1240 if (pfn_valid(start_pfn
)) {
1241 struct page
*page
= pfn_to_page(start_pfn
);
1243 init_reserved_page(start_pfn
);
1245 /* Avoid false-positive PageTail() */
1246 INIT_LIST_HEAD(&page
->lru
);
1248 SetPageReserved(page
);
1253 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1255 unsigned long flags
;
1257 unsigned long pfn
= page_to_pfn(page
);
1259 if (!free_pages_prepare(page
, order
, true))
1262 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1263 local_irq_save(flags
);
1264 __count_vm_events(PGFREE
, 1 << order
);
1265 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1266 local_irq_restore(flags
);
1269 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1271 unsigned int nr_pages
= 1 << order
;
1272 struct page
*p
= page
;
1276 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1278 __ClearPageReserved(p
);
1279 set_page_count(p
, 0);
1281 __ClearPageReserved(p
);
1282 set_page_count(p
, 0);
1284 page_zone(page
)->managed_pages
+= nr_pages
;
1285 set_page_refcounted(page
);
1286 __free_pages(page
, order
);
1289 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1290 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1292 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1294 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1296 static DEFINE_SPINLOCK(early_pfn_lock
);
1299 spin_lock(&early_pfn_lock
);
1300 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1302 nid
= first_online_node
;
1303 spin_unlock(&early_pfn_lock
);
1309 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1310 static inline bool __meminit __maybe_unused
1311 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1312 struct mminit_pfnnid_cache
*state
)
1316 nid
= __early_pfn_to_nid(pfn
, state
);
1317 if (nid
>= 0 && nid
!= node
)
1322 /* Only safe to use early in boot when initialisation is single-threaded */
1323 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1325 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1330 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1334 static inline bool __meminit __maybe_unused
1335 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1336 struct mminit_pfnnid_cache
*state
)
1343 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1346 if (early_page_uninitialised(pfn
))
1348 return __free_pages_boot_core(page
, order
);
1352 * Check that the whole (or subset of) a pageblock given by the interval of
1353 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1354 * with the migration of free compaction scanner. The scanners then need to
1355 * use only pfn_valid_within() check for arches that allow holes within
1358 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1360 * It's possible on some configurations to have a setup like node0 node1 node0
1361 * i.e. it's possible that all pages within a zones range of pages do not
1362 * belong to a single zone. We assume that a border between node0 and node1
1363 * can occur within a single pageblock, but not a node0 node1 node0
1364 * interleaving within a single pageblock. It is therefore sufficient to check
1365 * the first and last page of a pageblock and avoid checking each individual
1366 * page in a pageblock.
1368 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1369 unsigned long end_pfn
, struct zone
*zone
)
1371 struct page
*start_page
;
1372 struct page
*end_page
;
1374 /* end_pfn is one past the range we are checking */
1377 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1380 start_page
= pfn_to_online_page(start_pfn
);
1384 if (page_zone(start_page
) != zone
)
1387 end_page
= pfn_to_page(end_pfn
);
1389 /* This gives a shorter code than deriving page_zone(end_page) */
1390 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1396 void set_zone_contiguous(struct zone
*zone
)
1398 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1399 unsigned long block_end_pfn
;
1401 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1402 for (; block_start_pfn
< zone_end_pfn(zone
);
1403 block_start_pfn
= block_end_pfn
,
1404 block_end_pfn
+= pageblock_nr_pages
) {
1406 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1408 if (!__pageblock_pfn_to_page(block_start_pfn
,
1409 block_end_pfn
, zone
))
1413 /* We confirm that there is no hole */
1414 zone
->contiguous
= true;
1417 void clear_zone_contiguous(struct zone
*zone
)
1419 zone
->contiguous
= false;
1422 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1423 static void __init
deferred_free_range(unsigned long pfn
,
1424 unsigned long nr_pages
)
1432 page
= pfn_to_page(pfn
);
1434 /* Free a large naturally-aligned chunk if possible */
1435 if (nr_pages
== pageblock_nr_pages
&&
1436 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1437 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1438 __free_pages_boot_core(page
, pageblock_order
);
1442 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1443 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1444 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1445 __free_pages_boot_core(page
, 0);
1449 /* Completion tracking for deferred_init_memmap() threads */
1450 static atomic_t pgdat_init_n_undone __initdata
;
1451 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1453 static inline void __init
pgdat_init_report_one_done(void)
1455 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1456 complete(&pgdat_init_all_done_comp
);
1460 * Helper for deferred_init_range, free the given range, reset the counters, and
1461 * return number of pages freed.
1463 static inline unsigned long __init
__def_free(unsigned long *nr_free
,
1464 unsigned long *free_base_pfn
,
1467 unsigned long nr
= *nr_free
;
1469 deferred_free_range(*free_base_pfn
, nr
);
1477 static unsigned long __init
deferred_init_range(int nid
, int zid
,
1478 unsigned long start_pfn
,
1479 unsigned long end_pfn
)
1481 struct mminit_pfnnid_cache nid_init_state
= { };
1482 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1483 unsigned long free_base_pfn
= 0;
1484 unsigned long nr_pages
= 0;
1485 unsigned long nr_free
= 0;
1486 struct page
*page
= NULL
;
1490 * First we check if pfn is valid on architectures where it is possible
1491 * to have holes within pageblock_nr_pages. On systems where it is not
1492 * possible, this function is optimized out.
1494 * Then, we check if a current large page is valid by only checking the
1495 * validity of the head pfn.
1497 * meminit_pfn_in_nid is checked on systems where pfns can interleave
1498 * within a node: a pfn is between start and end of a node, but does not
1499 * belong to this memory node.
1501 * Finally, we minimize pfn page lookups and scheduler checks by
1502 * performing it only once every pageblock_nr_pages.
1504 * We do it in two loops: first we initialize struct page, than free to
1505 * buddy allocator, becuse while we are freeing pages we can access
1506 * pages that are ahead (computing buddy page in __free_one_page()).
1508 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
1509 if (!pfn_valid_within(pfn
))
1511 if ((pfn
& nr_pgmask
) || pfn_valid(pfn
)) {
1512 if (meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1513 if (page
&& (pfn
& nr_pgmask
))
1516 page
= pfn_to_page(pfn
);
1517 __init_single_page(page
, pfn
, zid
, nid
);
1524 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
1525 if (!pfn_valid_within(pfn
)) {
1526 nr_pages
+= __def_free(&nr_free
, &free_base_pfn
, &page
);
1527 } else if (!(pfn
& nr_pgmask
) && !pfn_valid(pfn
)) {
1528 nr_pages
+= __def_free(&nr_free
, &free_base_pfn
, &page
);
1529 } else if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1530 nr_pages
+= __def_free(&nr_free
, &free_base_pfn
, &page
);
1531 } else if (page
&& (pfn
& nr_pgmask
)) {
1535 nr_pages
+= __def_free(&nr_free
, &free_base_pfn
, &page
);
1536 page
= pfn_to_page(pfn
);
1537 free_base_pfn
= pfn
;
1542 /* Free the last block of pages to allocator */
1543 nr_pages
+= __def_free(&nr_free
, &free_base_pfn
, &page
);
1548 /* Initialise remaining memory on a node */
1549 static int __init
deferred_init_memmap(void *data
)
1551 pg_data_t
*pgdat
= data
;
1552 int nid
= pgdat
->node_id
;
1553 unsigned long start
= jiffies
;
1554 unsigned long nr_pages
= 0;
1555 unsigned long spfn
, epfn
;
1556 phys_addr_t spa
, epa
;
1559 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1560 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1563 if (first_init_pfn
== ULONG_MAX
) {
1564 pgdat_init_report_one_done();
1568 /* Bind memory initialisation thread to a local node if possible */
1569 if (!cpumask_empty(cpumask
))
1570 set_cpus_allowed_ptr(current
, cpumask
);
1572 /* Sanity check boundaries */
1573 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1574 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1575 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1577 /* Only the highest zone is deferred so find it */
1578 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1579 zone
= pgdat
->node_zones
+ zid
;
1580 if (first_init_pfn
< zone_end_pfn(zone
))
1583 first_init_pfn
= max(zone
->zone_start_pfn
, first_init_pfn
);
1585 for_each_free_mem_range(i
, nid
, MEMBLOCK_NONE
, &spa
, &epa
, NULL
) {
1586 spfn
= max_t(unsigned long, first_init_pfn
, PFN_UP(spa
));
1587 epfn
= min_t(unsigned long, zone_end_pfn(zone
), PFN_DOWN(epa
));
1588 nr_pages
+= deferred_init_range(nid
, zid
, spfn
, epfn
);
1591 /* Sanity check that the next zone really is unpopulated */
1592 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1594 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1595 jiffies_to_msecs(jiffies
- start
));
1597 pgdat_init_report_one_done();
1600 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1602 void __init
page_alloc_init_late(void)
1606 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1609 /* There will be num_node_state(N_MEMORY) threads */
1610 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1611 for_each_node_state(nid
, N_MEMORY
) {
1612 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1615 /* Block until all are initialised */
1616 wait_for_completion(&pgdat_init_all_done_comp
);
1618 /* Reinit limits that are based on free pages after the kernel is up */
1619 files_maxfiles_init();
1621 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
1622 /* Discard memblock private memory */
1626 for_each_populated_zone(zone
)
1627 set_zone_contiguous(zone
);
1631 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1632 void __init
init_cma_reserved_pageblock(struct page
*page
)
1634 unsigned i
= pageblock_nr_pages
;
1635 struct page
*p
= page
;
1638 __ClearPageReserved(p
);
1639 set_page_count(p
, 0);
1642 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1644 if (pageblock_order
>= MAX_ORDER
) {
1645 i
= pageblock_nr_pages
;
1648 set_page_refcounted(p
);
1649 __free_pages(p
, MAX_ORDER
- 1);
1650 p
+= MAX_ORDER_NR_PAGES
;
1651 } while (i
-= MAX_ORDER_NR_PAGES
);
1653 set_page_refcounted(page
);
1654 __free_pages(page
, pageblock_order
);
1657 adjust_managed_page_count(page
, pageblock_nr_pages
);
1662 * The order of subdivision here is critical for the IO subsystem.
1663 * Please do not alter this order without good reasons and regression
1664 * testing. Specifically, as large blocks of memory are subdivided,
1665 * the order in which smaller blocks are delivered depends on the order
1666 * they're subdivided in this function. This is the primary factor
1667 * influencing the order in which pages are delivered to the IO
1668 * subsystem according to empirical testing, and this is also justified
1669 * by considering the behavior of a buddy system containing a single
1670 * large block of memory acted on by a series of small allocations.
1671 * This behavior is a critical factor in sglist merging's success.
1675 static inline void expand(struct zone
*zone
, struct page
*page
,
1676 int low
, int high
, struct free_area
*area
,
1679 unsigned long size
= 1 << high
;
1681 while (high
> low
) {
1685 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1688 * Mark as guard pages (or page), that will allow to
1689 * merge back to allocator when buddy will be freed.
1690 * Corresponding page table entries will not be touched,
1691 * pages will stay not present in virtual address space
1693 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1696 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1698 set_page_order(&page
[size
], high
);
1702 static void check_new_page_bad(struct page
*page
)
1704 const char *bad_reason
= NULL
;
1705 unsigned long bad_flags
= 0;
1707 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1708 bad_reason
= "nonzero mapcount";
1709 if (unlikely(page
->mapping
!= NULL
))
1710 bad_reason
= "non-NULL mapping";
1711 if (unlikely(page_ref_count(page
) != 0))
1712 bad_reason
= "nonzero _count";
1713 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1714 bad_reason
= "HWPoisoned (hardware-corrupted)";
1715 bad_flags
= __PG_HWPOISON
;
1716 /* Don't complain about hwpoisoned pages */
1717 page_mapcount_reset(page
); /* remove PageBuddy */
1720 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1721 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1722 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1725 if (unlikely(page
->mem_cgroup
))
1726 bad_reason
= "page still charged to cgroup";
1728 bad_page(page
, bad_reason
, bad_flags
);
1732 * This page is about to be returned from the page allocator
1734 static inline int check_new_page(struct page
*page
)
1736 if (likely(page_expected_state(page
,
1737 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1740 check_new_page_bad(page
);
1744 static inline bool free_pages_prezeroed(void)
1746 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1747 page_poisoning_enabled();
1750 #ifdef CONFIG_DEBUG_VM
1751 static bool check_pcp_refill(struct page
*page
)
1756 static bool check_new_pcp(struct page
*page
)
1758 return check_new_page(page
);
1761 static bool check_pcp_refill(struct page
*page
)
1763 return check_new_page(page
);
1765 static bool check_new_pcp(struct page
*page
)
1769 #endif /* CONFIG_DEBUG_VM */
1771 static bool check_new_pages(struct page
*page
, unsigned int order
)
1774 for (i
= 0; i
< (1 << order
); i
++) {
1775 struct page
*p
= page
+ i
;
1777 if (unlikely(check_new_page(p
)))
1784 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1787 set_page_private(page
, 0);
1788 set_page_refcounted(page
);
1790 arch_alloc_page(page
, order
);
1791 kernel_map_pages(page
, 1 << order
, 1);
1792 kernel_poison_pages(page
, 1 << order
, 1);
1793 kasan_alloc_pages(page
, order
);
1794 set_page_owner(page
, order
, gfp_flags
);
1797 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1798 unsigned int alloc_flags
)
1802 post_alloc_hook(page
, order
, gfp_flags
);
1804 if (!free_pages_prezeroed() && (gfp_flags
& __GFP_ZERO
))
1805 for (i
= 0; i
< (1 << order
); i
++)
1806 clear_highpage(page
+ i
);
1808 if (order
&& (gfp_flags
& __GFP_COMP
))
1809 prep_compound_page(page
, order
);
1812 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1813 * allocate the page. The expectation is that the caller is taking
1814 * steps that will free more memory. The caller should avoid the page
1815 * being used for !PFMEMALLOC purposes.
1817 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1818 set_page_pfmemalloc(page
);
1820 clear_page_pfmemalloc(page
);
1824 * Go through the free lists for the given migratetype and remove
1825 * the smallest available page from the freelists
1827 static __always_inline
1828 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1831 unsigned int current_order
;
1832 struct free_area
*area
;
1835 /* Find a page of the appropriate size in the preferred list */
1836 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1837 area
= &(zone
->free_area
[current_order
]);
1838 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1842 list_del(&page
->lru
);
1843 rmv_page_order(page
);
1845 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1846 set_pcppage_migratetype(page
, migratetype
);
1855 * This array describes the order lists are fallen back to when
1856 * the free lists for the desirable migrate type are depleted
1858 static int fallbacks
[MIGRATE_TYPES
][4] = {
1859 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1860 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1861 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1863 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1865 #ifdef CONFIG_MEMORY_ISOLATION
1866 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1871 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1874 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1877 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1878 unsigned int order
) { return NULL
; }
1882 * Move the free pages in a range to the free lists of the requested type.
1883 * Note that start_page and end_pages are not aligned on a pageblock
1884 * boundary. If alignment is required, use move_freepages_block()
1886 static int move_freepages(struct zone
*zone
,
1887 struct page
*start_page
, struct page
*end_page
,
1888 int migratetype
, int *num_movable
)
1892 int pages_moved
= 0;
1894 #ifndef CONFIG_HOLES_IN_ZONE
1896 * page_zone is not safe to call in this context when
1897 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1898 * anyway as we check zone boundaries in move_freepages_block().
1899 * Remove at a later date when no bug reports exist related to
1900 * grouping pages by mobility
1902 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1908 for (page
= start_page
; page
<= end_page
;) {
1909 if (!pfn_valid_within(page_to_pfn(page
))) {
1914 /* Make sure we are not inadvertently changing nodes */
1915 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1917 if (!PageBuddy(page
)) {
1919 * We assume that pages that could be isolated for
1920 * migration are movable. But we don't actually try
1921 * isolating, as that would be expensive.
1924 (PageLRU(page
) || __PageMovable(page
)))
1931 order
= page_order(page
);
1932 list_move(&page
->lru
,
1933 &zone
->free_area
[order
].free_list
[migratetype
]);
1935 pages_moved
+= 1 << order
;
1941 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1942 int migratetype
, int *num_movable
)
1944 unsigned long start_pfn
, end_pfn
;
1945 struct page
*start_page
, *end_page
;
1947 start_pfn
= page_to_pfn(page
);
1948 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1949 start_page
= pfn_to_page(start_pfn
);
1950 end_page
= start_page
+ pageblock_nr_pages
- 1;
1951 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1953 /* Do not cross zone boundaries */
1954 if (!zone_spans_pfn(zone
, start_pfn
))
1956 if (!zone_spans_pfn(zone
, end_pfn
))
1959 return move_freepages(zone
, start_page
, end_page
, migratetype
,
1963 static void change_pageblock_range(struct page
*pageblock_page
,
1964 int start_order
, int migratetype
)
1966 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1968 while (nr_pageblocks
--) {
1969 set_pageblock_migratetype(pageblock_page
, migratetype
);
1970 pageblock_page
+= pageblock_nr_pages
;
1975 * When we are falling back to another migratetype during allocation, try to
1976 * steal extra free pages from the same pageblocks to satisfy further
1977 * allocations, instead of polluting multiple pageblocks.
1979 * If we are stealing a relatively large buddy page, it is likely there will
1980 * be more free pages in the pageblock, so try to steal them all. For
1981 * reclaimable and unmovable allocations, we steal regardless of page size,
1982 * as fragmentation caused by those allocations polluting movable pageblocks
1983 * is worse than movable allocations stealing from unmovable and reclaimable
1986 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1989 * Leaving this order check is intended, although there is
1990 * relaxed order check in next check. The reason is that
1991 * we can actually steal whole pageblock if this condition met,
1992 * but, below check doesn't guarantee it and that is just heuristic
1993 * so could be changed anytime.
1995 if (order
>= pageblock_order
)
1998 if (order
>= pageblock_order
/ 2 ||
1999 start_mt
== MIGRATE_RECLAIMABLE
||
2000 start_mt
== MIGRATE_UNMOVABLE
||
2001 page_group_by_mobility_disabled
)
2008 * This function implements actual steal behaviour. If order is large enough,
2009 * we can steal whole pageblock. If not, we first move freepages in this
2010 * pageblock to our migratetype and determine how many already-allocated pages
2011 * are there in the pageblock with a compatible migratetype. If at least half
2012 * of pages are free or compatible, we can change migratetype of the pageblock
2013 * itself, so pages freed in the future will be put on the correct free list.
2015 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2016 int start_type
, bool whole_block
)
2018 unsigned int current_order
= page_order(page
);
2019 struct free_area
*area
;
2020 int free_pages
, movable_pages
, alike_pages
;
2023 old_block_type
= get_pageblock_migratetype(page
);
2026 * This can happen due to races and we want to prevent broken
2027 * highatomic accounting.
2029 if (is_migrate_highatomic(old_block_type
))
2032 /* Take ownership for orders >= pageblock_order */
2033 if (current_order
>= pageblock_order
) {
2034 change_pageblock_range(page
, current_order
, start_type
);
2038 /* We are not allowed to try stealing from the whole block */
2042 free_pages
= move_freepages_block(zone
, page
, start_type
,
2045 * Determine how many pages are compatible with our allocation.
2046 * For movable allocation, it's the number of movable pages which
2047 * we just obtained. For other types it's a bit more tricky.
2049 if (start_type
== MIGRATE_MOVABLE
) {
2050 alike_pages
= movable_pages
;
2053 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2054 * to MOVABLE pageblock, consider all non-movable pages as
2055 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2056 * vice versa, be conservative since we can't distinguish the
2057 * exact migratetype of non-movable pages.
2059 if (old_block_type
== MIGRATE_MOVABLE
)
2060 alike_pages
= pageblock_nr_pages
2061 - (free_pages
+ movable_pages
);
2066 /* moving whole block can fail due to zone boundary conditions */
2071 * If a sufficient number of pages in the block are either free or of
2072 * comparable migratability as our allocation, claim the whole block.
2074 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2075 page_group_by_mobility_disabled
)
2076 set_pageblock_migratetype(page
, start_type
);
2081 area
= &zone
->free_area
[current_order
];
2082 list_move(&page
->lru
, &area
->free_list
[start_type
]);
2086 * Check whether there is a suitable fallback freepage with requested order.
2087 * If only_stealable is true, this function returns fallback_mt only if
2088 * we can steal other freepages all together. This would help to reduce
2089 * fragmentation due to mixed migratetype pages in one pageblock.
2091 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2092 int migratetype
, bool only_stealable
, bool *can_steal
)
2097 if (area
->nr_free
== 0)
2102 fallback_mt
= fallbacks
[migratetype
][i
];
2103 if (fallback_mt
== MIGRATE_TYPES
)
2106 if (list_empty(&area
->free_list
[fallback_mt
]))
2109 if (can_steal_fallback(order
, migratetype
))
2112 if (!only_stealable
)
2123 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2124 * there are no empty page blocks that contain a page with a suitable order
2126 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2127 unsigned int alloc_order
)
2130 unsigned long max_managed
, flags
;
2133 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2134 * Check is race-prone but harmless.
2136 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2137 if (zone
->nr_reserved_highatomic
>= max_managed
)
2140 spin_lock_irqsave(&zone
->lock
, flags
);
2142 /* Recheck the nr_reserved_highatomic limit under the lock */
2143 if (zone
->nr_reserved_highatomic
>= max_managed
)
2147 mt
= get_pageblock_migratetype(page
);
2148 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2149 && !is_migrate_cma(mt
)) {
2150 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2151 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2152 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2156 spin_unlock_irqrestore(&zone
->lock
, flags
);
2160 * Used when an allocation is about to fail under memory pressure. This
2161 * potentially hurts the reliability of high-order allocations when under
2162 * intense memory pressure but failed atomic allocations should be easier
2163 * to recover from than an OOM.
2165 * If @force is true, try to unreserve a pageblock even though highatomic
2166 * pageblock is exhausted.
2168 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2171 struct zonelist
*zonelist
= ac
->zonelist
;
2172 unsigned long flags
;
2179 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2182 * Preserve at least one pageblock unless memory pressure
2185 if (!force
&& zone
->nr_reserved_highatomic
<=
2189 spin_lock_irqsave(&zone
->lock
, flags
);
2190 for (order
= 0; order
< MAX_ORDER
; order
++) {
2191 struct free_area
*area
= &(zone
->free_area
[order
]);
2193 page
= list_first_entry_or_null(
2194 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2200 * In page freeing path, migratetype change is racy so
2201 * we can counter several free pages in a pageblock
2202 * in this loop althoug we changed the pageblock type
2203 * from highatomic to ac->migratetype. So we should
2204 * adjust the count once.
2206 if (is_migrate_highatomic_page(page
)) {
2208 * It should never happen but changes to
2209 * locking could inadvertently allow a per-cpu
2210 * drain to add pages to MIGRATE_HIGHATOMIC
2211 * while unreserving so be safe and watch for
2214 zone
->nr_reserved_highatomic
-= min(
2216 zone
->nr_reserved_highatomic
);
2220 * Convert to ac->migratetype and avoid the normal
2221 * pageblock stealing heuristics. Minimally, the caller
2222 * is doing the work and needs the pages. More
2223 * importantly, if the block was always converted to
2224 * MIGRATE_UNMOVABLE or another type then the number
2225 * of pageblocks that cannot be completely freed
2228 set_pageblock_migratetype(page
, ac
->migratetype
);
2229 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2232 spin_unlock_irqrestore(&zone
->lock
, flags
);
2236 spin_unlock_irqrestore(&zone
->lock
, flags
);
2243 * Try finding a free buddy page on the fallback list and put it on the free
2244 * list of requested migratetype, possibly along with other pages from the same
2245 * block, depending on fragmentation avoidance heuristics. Returns true if
2246 * fallback was found so that __rmqueue_smallest() can grab it.
2248 * The use of signed ints for order and current_order is a deliberate
2249 * deviation from the rest of this file, to make the for loop
2250 * condition simpler.
2252 static __always_inline
bool
2253 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
2255 struct free_area
*area
;
2262 * Find the largest available free page in the other list. This roughly
2263 * approximates finding the pageblock with the most free pages, which
2264 * would be too costly to do exactly.
2266 for (current_order
= MAX_ORDER
- 1; current_order
>= order
;
2268 area
= &(zone
->free_area
[current_order
]);
2269 fallback_mt
= find_suitable_fallback(area
, current_order
,
2270 start_migratetype
, false, &can_steal
);
2271 if (fallback_mt
== -1)
2275 * We cannot steal all free pages from the pageblock and the
2276 * requested migratetype is movable. In that case it's better to
2277 * steal and split the smallest available page instead of the
2278 * largest available page, because even if the next movable
2279 * allocation falls back into a different pageblock than this
2280 * one, it won't cause permanent fragmentation.
2282 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2283 && current_order
> order
)
2292 for (current_order
= order
; current_order
< MAX_ORDER
;
2294 area
= &(zone
->free_area
[current_order
]);
2295 fallback_mt
= find_suitable_fallback(area
, current_order
,
2296 start_migratetype
, false, &can_steal
);
2297 if (fallback_mt
!= -1)
2302 * This should not happen - we already found a suitable fallback
2303 * when looking for the largest page.
2305 VM_BUG_ON(current_order
== MAX_ORDER
);
2308 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2311 steal_suitable_fallback(zone
, page
, start_migratetype
, can_steal
);
2313 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2314 start_migratetype
, fallback_mt
);
2321 * Do the hard work of removing an element from the buddy allocator.
2322 * Call me with the zone->lock already held.
2324 static __always_inline
struct page
*
2325 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
)
2330 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2331 if (unlikely(!page
)) {
2332 if (migratetype
== MIGRATE_MOVABLE
)
2333 page
= __rmqueue_cma_fallback(zone
, order
);
2335 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
))
2339 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2344 * Obtain a specified number of elements from the buddy allocator, all under
2345 * a single hold of the lock, for efficiency. Add them to the supplied list.
2346 * Returns the number of new pages which were placed at *list.
2348 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2349 unsigned long count
, struct list_head
*list
,
2354 spin_lock(&zone
->lock
);
2355 for (i
= 0; i
< count
; ++i
) {
2356 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2357 if (unlikely(page
== NULL
))
2360 if (unlikely(check_pcp_refill(page
)))
2364 * Split buddy pages returned by expand() are received here in
2365 * physical page order. The page is added to the tail of
2366 * caller's list. From the callers perspective, the linked list
2367 * is ordered by page number under some conditions. This is
2368 * useful for IO devices that can forward direction from the
2369 * head, thus also in the physical page order. This is useful
2370 * for IO devices that can merge IO requests if the physical
2371 * pages are ordered properly.
2373 list_add_tail(&page
->lru
, list
);
2375 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2376 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2381 * i pages were removed from the buddy list even if some leak due
2382 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2383 * on i. Do not confuse with 'alloced' which is the number of
2384 * pages added to the pcp list.
2386 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2387 spin_unlock(&zone
->lock
);
2393 * Called from the vmstat counter updater to drain pagesets of this
2394 * currently executing processor on remote nodes after they have
2397 * Note that this function must be called with the thread pinned to
2398 * a single processor.
2400 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2402 unsigned long flags
;
2403 int to_drain
, batch
;
2405 local_irq_save(flags
);
2406 batch
= READ_ONCE(pcp
->batch
);
2407 to_drain
= min(pcp
->count
, batch
);
2409 free_pcppages_bulk(zone
, to_drain
, pcp
);
2410 pcp
->count
-= to_drain
;
2412 local_irq_restore(flags
);
2417 * Drain pcplists of the indicated processor and zone.
2419 * The processor must either be the current processor and the
2420 * thread pinned to the current processor or a processor that
2423 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2425 unsigned long flags
;
2426 struct per_cpu_pageset
*pset
;
2427 struct per_cpu_pages
*pcp
;
2429 local_irq_save(flags
);
2430 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2434 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2437 local_irq_restore(flags
);
2441 * Drain pcplists of all zones on the indicated processor.
2443 * The processor must either be the current processor and the
2444 * thread pinned to the current processor or a processor that
2447 static void drain_pages(unsigned int cpu
)
2451 for_each_populated_zone(zone
) {
2452 drain_pages_zone(cpu
, zone
);
2457 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2459 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2460 * the single zone's pages.
2462 void drain_local_pages(struct zone
*zone
)
2464 int cpu
= smp_processor_id();
2467 drain_pages_zone(cpu
, zone
);
2472 static void drain_local_pages_wq(struct work_struct
*work
)
2475 * drain_all_pages doesn't use proper cpu hotplug protection so
2476 * we can race with cpu offline when the WQ can move this from
2477 * a cpu pinned worker to an unbound one. We can operate on a different
2478 * cpu which is allright but we also have to make sure to not move to
2482 drain_local_pages(NULL
);
2487 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2489 * When zone parameter is non-NULL, spill just the single zone's pages.
2491 * Note that this can be extremely slow as the draining happens in a workqueue.
2493 void drain_all_pages(struct zone
*zone
)
2498 * Allocate in the BSS so we wont require allocation in
2499 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2501 static cpumask_t cpus_with_pcps
;
2504 * Make sure nobody triggers this path before mm_percpu_wq is fully
2507 if (WARN_ON_ONCE(!mm_percpu_wq
))
2510 /* Workqueues cannot recurse */
2511 if (current
->flags
& PF_WQ_WORKER
)
2515 * Do not drain if one is already in progress unless it's specific to
2516 * a zone. Such callers are primarily CMA and memory hotplug and need
2517 * the drain to be complete when the call returns.
2519 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2522 mutex_lock(&pcpu_drain_mutex
);
2526 * We don't care about racing with CPU hotplug event
2527 * as offline notification will cause the notified
2528 * cpu to drain that CPU pcps and on_each_cpu_mask
2529 * disables preemption as part of its processing
2531 for_each_online_cpu(cpu
) {
2532 struct per_cpu_pageset
*pcp
;
2534 bool has_pcps
= false;
2537 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2541 for_each_populated_zone(z
) {
2542 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2543 if (pcp
->pcp
.count
) {
2551 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2553 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2556 for_each_cpu(cpu
, &cpus_with_pcps
) {
2557 struct work_struct
*work
= per_cpu_ptr(&pcpu_drain
, cpu
);
2558 INIT_WORK(work
, drain_local_pages_wq
);
2559 queue_work_on(cpu
, mm_percpu_wq
, work
);
2561 for_each_cpu(cpu
, &cpus_with_pcps
)
2562 flush_work(per_cpu_ptr(&pcpu_drain
, cpu
));
2564 mutex_unlock(&pcpu_drain_mutex
);
2567 #ifdef CONFIG_HIBERNATION
2570 * Touch the watchdog for every WD_PAGE_COUNT pages.
2572 #define WD_PAGE_COUNT (128*1024)
2574 void mark_free_pages(struct zone
*zone
)
2576 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
2577 unsigned long flags
;
2578 unsigned int order
, t
;
2581 if (zone_is_empty(zone
))
2584 spin_lock_irqsave(&zone
->lock
, flags
);
2586 max_zone_pfn
= zone_end_pfn(zone
);
2587 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2588 if (pfn_valid(pfn
)) {
2589 page
= pfn_to_page(pfn
);
2591 if (!--page_count
) {
2592 touch_nmi_watchdog();
2593 page_count
= WD_PAGE_COUNT
;
2596 if (page_zone(page
) != zone
)
2599 if (!swsusp_page_is_forbidden(page
))
2600 swsusp_unset_page_free(page
);
2603 for_each_migratetype_order(order
, t
) {
2604 list_for_each_entry(page
,
2605 &zone
->free_area
[order
].free_list
[t
], lru
) {
2608 pfn
= page_to_pfn(page
);
2609 for (i
= 0; i
< (1UL << order
); i
++) {
2610 if (!--page_count
) {
2611 touch_nmi_watchdog();
2612 page_count
= WD_PAGE_COUNT
;
2614 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2618 spin_unlock_irqrestore(&zone
->lock
, flags
);
2620 #endif /* CONFIG_PM */
2622 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
2626 if (!free_pcp_prepare(page
))
2629 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2630 set_pcppage_migratetype(page
, migratetype
);
2634 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
2636 struct zone
*zone
= page_zone(page
);
2637 struct per_cpu_pages
*pcp
;
2640 migratetype
= get_pcppage_migratetype(page
);
2641 __count_vm_event(PGFREE
);
2644 * We only track unmovable, reclaimable and movable on pcp lists.
2645 * Free ISOLATE pages back to the allocator because they are being
2646 * offlined but treat HIGHATOMIC as movable pages so we can get those
2647 * areas back if necessary. Otherwise, we may have to free
2648 * excessively into the page allocator
2650 if (migratetype
>= MIGRATE_PCPTYPES
) {
2651 if (unlikely(is_migrate_isolate(migratetype
))) {
2652 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2655 migratetype
= MIGRATE_MOVABLE
;
2658 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2659 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2661 if (pcp
->count
>= pcp
->high
) {
2662 unsigned long batch
= READ_ONCE(pcp
->batch
);
2663 free_pcppages_bulk(zone
, batch
, pcp
);
2664 pcp
->count
-= batch
;
2669 * Free a 0-order page
2671 void free_unref_page(struct page
*page
)
2673 unsigned long flags
;
2674 unsigned long pfn
= page_to_pfn(page
);
2676 if (!free_unref_page_prepare(page
, pfn
))
2679 local_irq_save(flags
);
2680 free_unref_page_commit(page
, pfn
);
2681 local_irq_restore(flags
);
2685 * Free a list of 0-order pages
2687 void free_unref_page_list(struct list_head
*list
)
2689 struct page
*page
, *next
;
2690 unsigned long flags
, pfn
;
2692 /* Prepare pages for freeing */
2693 list_for_each_entry_safe(page
, next
, list
, lru
) {
2694 pfn
= page_to_pfn(page
);
2695 if (!free_unref_page_prepare(page
, pfn
))
2696 list_del(&page
->lru
);
2697 set_page_private(page
, pfn
);
2700 local_irq_save(flags
);
2701 list_for_each_entry_safe(page
, next
, list
, lru
) {
2702 unsigned long pfn
= page_private(page
);
2704 set_page_private(page
, 0);
2705 trace_mm_page_free_batched(page
);
2706 free_unref_page_commit(page
, pfn
);
2708 local_irq_restore(flags
);
2712 * split_page takes a non-compound higher-order page, and splits it into
2713 * n (1<<order) sub-pages: page[0..n]
2714 * Each sub-page must be freed individually.
2716 * Note: this is probably too low level an operation for use in drivers.
2717 * Please consult with lkml before using this in your driver.
2719 void split_page(struct page
*page
, unsigned int order
)
2723 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2724 VM_BUG_ON_PAGE(!page_count(page
), page
);
2726 for (i
= 1; i
< (1 << order
); i
++)
2727 set_page_refcounted(page
+ i
);
2728 split_page_owner(page
, order
);
2730 EXPORT_SYMBOL_GPL(split_page
);
2732 int __isolate_free_page(struct page
*page
, unsigned int order
)
2734 unsigned long watermark
;
2738 BUG_ON(!PageBuddy(page
));
2740 zone
= page_zone(page
);
2741 mt
= get_pageblock_migratetype(page
);
2743 if (!is_migrate_isolate(mt
)) {
2745 * Obey watermarks as if the page was being allocated. We can
2746 * emulate a high-order watermark check with a raised order-0
2747 * watermark, because we already know our high-order page
2750 watermark
= min_wmark_pages(zone
) + (1UL << order
);
2751 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
2754 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2757 /* Remove page from free list */
2758 list_del(&page
->lru
);
2759 zone
->free_area
[order
].nr_free
--;
2760 rmv_page_order(page
);
2763 * Set the pageblock if the isolated page is at least half of a
2766 if (order
>= pageblock_order
- 1) {
2767 struct page
*endpage
= page
+ (1 << order
) - 1;
2768 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2769 int mt
= get_pageblock_migratetype(page
);
2770 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
2771 && !is_migrate_highatomic(mt
))
2772 set_pageblock_migratetype(page
,
2778 return 1UL << order
;
2782 * Update NUMA hit/miss statistics
2784 * Must be called with interrupts disabled.
2786 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
2789 enum numa_stat_item local_stat
= NUMA_LOCAL
;
2791 /* skip numa counters update if numa stats is disabled */
2792 if (!static_branch_likely(&vm_numa_stat_key
))
2795 if (z
->node
!= numa_node_id())
2796 local_stat
= NUMA_OTHER
;
2798 if (z
->node
== preferred_zone
->node
)
2799 __inc_numa_state(z
, NUMA_HIT
);
2801 __inc_numa_state(z
, NUMA_MISS
);
2802 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
2804 __inc_numa_state(z
, local_stat
);
2808 /* Remove page from the per-cpu list, caller must protect the list */
2809 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
2810 struct per_cpu_pages
*pcp
,
2811 struct list_head
*list
)
2816 if (list_empty(list
)) {
2817 pcp
->count
+= rmqueue_bulk(zone
, 0,
2820 if (unlikely(list_empty(list
)))
2824 page
= list_first_entry(list
, struct page
, lru
);
2825 list_del(&page
->lru
);
2827 } while (check_new_pcp(page
));
2832 /* Lock and remove page from the per-cpu list */
2833 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
2834 struct zone
*zone
, unsigned int order
,
2835 gfp_t gfp_flags
, int migratetype
)
2837 struct per_cpu_pages
*pcp
;
2838 struct list_head
*list
;
2840 unsigned long flags
;
2842 local_irq_save(flags
);
2843 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2844 list
= &pcp
->lists
[migratetype
];
2845 page
= __rmqueue_pcplist(zone
, migratetype
, pcp
, list
);
2847 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2848 zone_statistics(preferred_zone
, zone
);
2850 local_irq_restore(flags
);
2855 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2858 struct page
*rmqueue(struct zone
*preferred_zone
,
2859 struct zone
*zone
, unsigned int order
,
2860 gfp_t gfp_flags
, unsigned int alloc_flags
,
2863 unsigned long flags
;
2866 if (likely(order
== 0)) {
2867 page
= rmqueue_pcplist(preferred_zone
, zone
, order
,
2868 gfp_flags
, migratetype
);
2873 * We most definitely don't want callers attempting to
2874 * allocate greater than order-1 page units with __GFP_NOFAIL.
2876 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2877 spin_lock_irqsave(&zone
->lock
, flags
);
2881 if (alloc_flags
& ALLOC_HARDER
) {
2882 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2884 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2887 page
= __rmqueue(zone
, order
, migratetype
);
2888 } while (page
&& check_new_pages(page
, order
));
2889 spin_unlock(&zone
->lock
);
2892 __mod_zone_freepage_state(zone
, -(1 << order
),
2893 get_pcppage_migratetype(page
));
2895 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2896 zone_statistics(preferred_zone
, zone
);
2897 local_irq_restore(flags
);
2900 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
2904 local_irq_restore(flags
);
2908 #ifdef CONFIG_FAIL_PAGE_ALLOC
2911 struct fault_attr attr
;
2913 bool ignore_gfp_highmem
;
2914 bool ignore_gfp_reclaim
;
2916 } fail_page_alloc
= {
2917 .attr
= FAULT_ATTR_INITIALIZER
,
2918 .ignore_gfp_reclaim
= true,
2919 .ignore_gfp_highmem
= true,
2923 static int __init
setup_fail_page_alloc(char *str
)
2925 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2927 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2929 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2931 if (order
< fail_page_alloc
.min_order
)
2933 if (gfp_mask
& __GFP_NOFAIL
)
2935 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2937 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2938 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2941 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2944 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2946 static int __init
fail_page_alloc_debugfs(void)
2948 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2951 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2952 &fail_page_alloc
.attr
);
2954 return PTR_ERR(dir
);
2956 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2957 &fail_page_alloc
.ignore_gfp_reclaim
))
2959 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2960 &fail_page_alloc
.ignore_gfp_highmem
))
2962 if (!debugfs_create_u32("min-order", mode
, dir
,
2963 &fail_page_alloc
.min_order
))
2968 debugfs_remove_recursive(dir
);
2973 late_initcall(fail_page_alloc_debugfs
);
2975 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2977 #else /* CONFIG_FAIL_PAGE_ALLOC */
2979 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2984 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2987 * Return true if free base pages are above 'mark'. For high-order checks it
2988 * will return true of the order-0 watermark is reached and there is at least
2989 * one free page of a suitable size. Checking now avoids taking the zone lock
2990 * to check in the allocation paths if no pages are free.
2992 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2993 int classzone_idx
, unsigned int alloc_flags
,
2998 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3000 /* free_pages may go negative - that's OK */
3001 free_pages
-= (1 << order
) - 1;
3003 if (alloc_flags
& ALLOC_HIGH
)
3007 * If the caller does not have rights to ALLOC_HARDER then subtract
3008 * the high-atomic reserves. This will over-estimate the size of the
3009 * atomic reserve but it avoids a search.
3011 if (likely(!alloc_harder
)) {
3012 free_pages
-= z
->nr_reserved_highatomic
;
3015 * OOM victims can try even harder than normal ALLOC_HARDER
3016 * users on the grounds that it's definitely going to be in
3017 * the exit path shortly and free memory. Any allocation it
3018 * makes during the free path will be small and short-lived.
3020 if (alloc_flags
& ALLOC_OOM
)
3028 /* If allocation can't use CMA areas don't use free CMA pages */
3029 if (!(alloc_flags
& ALLOC_CMA
))
3030 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3034 * Check watermarks for an order-0 allocation request. If these
3035 * are not met, then a high-order request also cannot go ahead
3036 * even if a suitable page happened to be free.
3038 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
3041 /* If this is an order-0 request then the watermark is fine */
3045 /* For a high-order request, check at least one suitable page is free */
3046 for (o
= order
; o
< MAX_ORDER
; o
++) {
3047 struct free_area
*area
= &z
->free_area
[o
];
3053 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3054 if (!list_empty(&area
->free_list
[mt
]))
3059 if ((alloc_flags
& ALLOC_CMA
) &&
3060 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
3065 !list_empty(&area
->free_list
[MIGRATE_HIGHATOMIC
]))
3071 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3072 int classzone_idx
, unsigned int alloc_flags
)
3074 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3075 zone_page_state(z
, NR_FREE_PAGES
));
3078 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3079 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
3081 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3085 /* If allocation can't use CMA areas don't use free CMA pages */
3086 if (!(alloc_flags
& ALLOC_CMA
))
3087 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3091 * Fast check for order-0 only. If this fails then the reserves
3092 * need to be calculated. There is a corner case where the check
3093 * passes but only the high-order atomic reserve are free. If
3094 * the caller is !atomic then it'll uselessly search the free
3095 * list. That corner case is then slower but it is harmless.
3097 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
3100 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3104 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3105 unsigned long mark
, int classzone_idx
)
3107 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3109 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3110 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3112 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
3117 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3119 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3122 #else /* CONFIG_NUMA */
3123 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3127 #endif /* CONFIG_NUMA */
3130 * get_page_from_freelist goes through the zonelist trying to allocate
3133 static struct page
*
3134 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3135 const struct alloc_context
*ac
)
3137 struct zoneref
*z
= ac
->preferred_zoneref
;
3139 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3142 * Scan zonelist, looking for a zone with enough free.
3143 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3145 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3150 if (cpusets_enabled() &&
3151 (alloc_flags
& ALLOC_CPUSET
) &&
3152 !__cpuset_zone_allowed(zone
, gfp_mask
))
3155 * When allocating a page cache page for writing, we
3156 * want to get it from a node that is within its dirty
3157 * limit, such that no single node holds more than its
3158 * proportional share of globally allowed dirty pages.
3159 * The dirty limits take into account the node's
3160 * lowmem reserves and high watermark so that kswapd
3161 * should be able to balance it without having to
3162 * write pages from its LRU list.
3164 * XXX: For now, allow allocations to potentially
3165 * exceed the per-node dirty limit in the slowpath
3166 * (spread_dirty_pages unset) before going into reclaim,
3167 * which is important when on a NUMA setup the allowed
3168 * nodes are together not big enough to reach the
3169 * global limit. The proper fix for these situations
3170 * will require awareness of nodes in the
3171 * dirty-throttling and the flusher threads.
3173 if (ac
->spread_dirty_pages
) {
3174 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3177 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3178 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3183 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
3184 if (!zone_watermark_fast(zone
, order
, mark
,
3185 ac_classzone_idx(ac
), alloc_flags
)) {
3188 /* Checked here to keep the fast path fast */
3189 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3190 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3193 if (node_reclaim_mode
== 0 ||
3194 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3197 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3199 case NODE_RECLAIM_NOSCAN
:
3202 case NODE_RECLAIM_FULL
:
3203 /* scanned but unreclaimable */
3206 /* did we reclaim enough */
3207 if (zone_watermark_ok(zone
, order
, mark
,
3208 ac_classzone_idx(ac
), alloc_flags
))
3216 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3217 gfp_mask
, alloc_flags
, ac
->migratetype
);
3219 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3222 * If this is a high-order atomic allocation then check
3223 * if the pageblock should be reserved for the future
3225 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3226 reserve_highatomic_pageblock(page
, zone
, order
);
3236 * Large machines with many possible nodes should not always dump per-node
3237 * meminfo in irq context.
3239 static inline bool should_suppress_show_mem(void)
3244 ret
= in_interrupt();
3249 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3251 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3252 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3254 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs
))
3258 * This documents exceptions given to allocations in certain
3259 * contexts that are allowed to allocate outside current's set
3262 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3263 if (tsk_is_oom_victim(current
) ||
3264 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3265 filter
&= ~SHOW_MEM_FILTER_NODES
;
3266 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3267 filter
&= ~SHOW_MEM_FILTER_NODES
;
3269 show_mem(filter
, nodemask
);
3272 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3274 struct va_format vaf
;
3276 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3277 DEFAULT_RATELIMIT_BURST
);
3279 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3282 va_start(args
, fmt
);
3285 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl\n",
3286 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
3287 nodemask_pr_args(nodemask
));
3290 cpuset_print_current_mems_allowed();
3293 warn_alloc_show_mem(gfp_mask
, nodemask
);
3296 static inline struct page
*
3297 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3298 unsigned int alloc_flags
,
3299 const struct alloc_context
*ac
)
3303 page
= get_page_from_freelist(gfp_mask
, order
,
3304 alloc_flags
|ALLOC_CPUSET
, ac
);
3306 * fallback to ignore cpuset restriction if our nodes
3310 page
= get_page_from_freelist(gfp_mask
, order
,
3316 static inline struct page
*
3317 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3318 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3320 struct oom_control oc
= {
3321 .zonelist
= ac
->zonelist
,
3322 .nodemask
= ac
->nodemask
,
3324 .gfp_mask
= gfp_mask
,
3329 *did_some_progress
= 0;
3332 * Acquire the oom lock. If that fails, somebody else is
3333 * making progress for us.
3335 if (!mutex_trylock(&oom_lock
)) {
3336 *did_some_progress
= 1;
3337 schedule_timeout_uninterruptible(1);
3342 * Go through the zonelist yet one more time, keep very high watermark
3343 * here, this is only to catch a parallel oom killing, we must fail if
3344 * we're still under heavy pressure. But make sure that this reclaim
3345 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3346 * allocation which will never fail due to oom_lock already held.
3348 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
3349 ~__GFP_DIRECT_RECLAIM
, order
,
3350 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3354 /* Coredumps can quickly deplete all memory reserves */
3355 if (current
->flags
& PF_DUMPCORE
)
3357 /* The OOM killer will not help higher order allocs */
3358 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3361 * We have already exhausted all our reclaim opportunities without any
3362 * success so it is time to admit defeat. We will skip the OOM killer
3363 * because it is very likely that the caller has a more reasonable
3364 * fallback than shooting a random task.
3366 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
3368 /* The OOM killer does not needlessly kill tasks for lowmem */
3369 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3371 if (pm_suspended_storage())
3374 * XXX: GFP_NOFS allocations should rather fail than rely on
3375 * other request to make a forward progress.
3376 * We are in an unfortunate situation where out_of_memory cannot
3377 * do much for this context but let's try it to at least get
3378 * access to memory reserved if the current task is killed (see
3379 * out_of_memory). Once filesystems are ready to handle allocation
3380 * failures more gracefully we should just bail out here.
3383 /* The OOM killer may not free memory on a specific node */
3384 if (gfp_mask
& __GFP_THISNODE
)
3387 /* Exhausted what can be done so it's blamo time */
3388 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3389 *did_some_progress
= 1;
3392 * Help non-failing allocations by giving them access to memory
3395 if (gfp_mask
& __GFP_NOFAIL
)
3396 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3397 ALLOC_NO_WATERMARKS
, ac
);
3400 mutex_unlock(&oom_lock
);
3405 * Maximum number of compaction retries wit a progress before OOM
3406 * killer is consider as the only way to move forward.
3408 #define MAX_COMPACT_RETRIES 16
3410 #ifdef CONFIG_COMPACTION
3411 /* Try memory compaction for high-order allocations before reclaim */
3412 static struct page
*
3413 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3414 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3415 enum compact_priority prio
, enum compact_result
*compact_result
)
3418 unsigned int noreclaim_flag
;
3423 noreclaim_flag
= memalloc_noreclaim_save();
3424 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3426 memalloc_noreclaim_restore(noreclaim_flag
);
3428 if (*compact_result
<= COMPACT_INACTIVE
)
3432 * At least in one zone compaction wasn't deferred or skipped, so let's
3433 * count a compaction stall
3435 count_vm_event(COMPACTSTALL
);
3437 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3440 struct zone
*zone
= page_zone(page
);
3442 zone
->compact_blockskip_flush
= false;
3443 compaction_defer_reset(zone
, order
, true);
3444 count_vm_event(COMPACTSUCCESS
);
3449 * It's bad if compaction run occurs and fails. The most likely reason
3450 * is that pages exist, but not enough to satisfy watermarks.
3452 count_vm_event(COMPACTFAIL
);
3460 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3461 enum compact_result compact_result
,
3462 enum compact_priority
*compact_priority
,
3463 int *compaction_retries
)
3465 int max_retries
= MAX_COMPACT_RETRIES
;
3468 int retries
= *compaction_retries
;
3469 enum compact_priority priority
= *compact_priority
;
3474 if (compaction_made_progress(compact_result
))
3475 (*compaction_retries
)++;
3478 * compaction considers all the zone as desperately out of memory
3479 * so it doesn't really make much sense to retry except when the
3480 * failure could be caused by insufficient priority
3482 if (compaction_failed(compact_result
))
3483 goto check_priority
;
3486 * make sure the compaction wasn't deferred or didn't bail out early
3487 * due to locks contention before we declare that we should give up.
3488 * But do not retry if the given zonelist is not suitable for
3491 if (compaction_withdrawn(compact_result
)) {
3492 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3497 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3498 * costly ones because they are de facto nofail and invoke OOM
3499 * killer to move on while costly can fail and users are ready
3500 * to cope with that. 1/4 retries is rather arbitrary but we
3501 * would need much more detailed feedback from compaction to
3502 * make a better decision.
3504 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3506 if (*compaction_retries
<= max_retries
) {
3512 * Make sure there are attempts at the highest priority if we exhausted
3513 * all retries or failed at the lower priorities.
3516 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3517 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3519 if (*compact_priority
> min_priority
) {
3520 (*compact_priority
)--;
3521 *compaction_retries
= 0;
3525 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3529 static inline struct page
*
3530 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3531 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3532 enum compact_priority prio
, enum compact_result
*compact_result
)
3534 *compact_result
= COMPACT_SKIPPED
;
3539 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3540 enum compact_result compact_result
,
3541 enum compact_priority
*compact_priority
,
3542 int *compaction_retries
)
3547 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3551 * There are setups with compaction disabled which would prefer to loop
3552 * inside the allocator rather than hit the oom killer prematurely.
3553 * Let's give them a good hope and keep retrying while the order-0
3554 * watermarks are OK.
3556 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3558 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3559 ac_classzone_idx(ac
), alloc_flags
))
3564 #endif /* CONFIG_COMPACTION */
3566 #ifdef CONFIG_LOCKDEP
3567 struct lockdep_map __fs_reclaim_map
=
3568 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
3570 static bool __need_fs_reclaim(gfp_t gfp_mask
)
3572 gfp_mask
= current_gfp_context(gfp_mask
);
3574 /* no reclaim without waiting on it */
3575 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3578 /* this guy won't enter reclaim */
3579 if ((current
->flags
& PF_MEMALLOC
) && !(gfp_mask
& __GFP_NOMEMALLOC
))
3582 /* We're only interested __GFP_FS allocations for now */
3583 if (!(gfp_mask
& __GFP_FS
))
3586 if (gfp_mask
& __GFP_NOLOCKDEP
)
3592 void fs_reclaim_acquire(gfp_t gfp_mask
)
3594 if (__need_fs_reclaim(gfp_mask
))
3595 lock_map_acquire(&__fs_reclaim_map
);
3597 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
3599 void fs_reclaim_release(gfp_t gfp_mask
)
3601 if (__need_fs_reclaim(gfp_mask
))
3602 lock_map_release(&__fs_reclaim_map
);
3604 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
3607 /* Perform direct synchronous page reclaim */
3609 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3610 const struct alloc_context
*ac
)
3612 struct reclaim_state reclaim_state
;
3614 unsigned int noreclaim_flag
;
3618 /* We now go into synchronous reclaim */
3619 cpuset_memory_pressure_bump();
3620 noreclaim_flag
= memalloc_noreclaim_save();
3621 fs_reclaim_acquire(gfp_mask
);
3622 reclaim_state
.reclaimed_slab
= 0;
3623 current
->reclaim_state
= &reclaim_state
;
3625 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3628 current
->reclaim_state
= NULL
;
3629 fs_reclaim_release(gfp_mask
);
3630 memalloc_noreclaim_restore(noreclaim_flag
);
3637 /* The really slow allocator path where we enter direct reclaim */
3638 static inline struct page
*
3639 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3640 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3641 unsigned long *did_some_progress
)
3643 struct page
*page
= NULL
;
3644 bool drained
= false;
3646 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3647 if (unlikely(!(*did_some_progress
)))
3651 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3654 * If an allocation failed after direct reclaim, it could be because
3655 * pages are pinned on the per-cpu lists or in high alloc reserves.
3656 * Shrink them them and try again
3658 if (!page
&& !drained
) {
3659 unreserve_highatomic_pageblock(ac
, false);
3660 drain_all_pages(NULL
);
3668 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3672 pg_data_t
*last_pgdat
= NULL
;
3674 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3675 ac
->high_zoneidx
, ac
->nodemask
) {
3676 if (last_pgdat
!= zone
->zone_pgdat
)
3677 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3678 last_pgdat
= zone
->zone_pgdat
;
3682 static inline unsigned int
3683 gfp_to_alloc_flags(gfp_t gfp_mask
)
3685 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3687 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3688 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3691 * The caller may dip into page reserves a bit more if the caller
3692 * cannot run direct reclaim, or if the caller has realtime scheduling
3693 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3694 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3696 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3698 if (gfp_mask
& __GFP_ATOMIC
) {
3700 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3701 * if it can't schedule.
3703 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3704 alloc_flags
|= ALLOC_HARDER
;
3706 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3707 * comment for __cpuset_node_allowed().
3709 alloc_flags
&= ~ALLOC_CPUSET
;
3710 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3711 alloc_flags
|= ALLOC_HARDER
;
3714 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3715 alloc_flags
|= ALLOC_CMA
;
3720 static bool oom_reserves_allowed(struct task_struct
*tsk
)
3722 if (!tsk_is_oom_victim(tsk
))
3726 * !MMU doesn't have oom reaper so give access to memory reserves
3727 * only to the thread with TIF_MEMDIE set
3729 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
3736 * Distinguish requests which really need access to full memory
3737 * reserves from oom victims which can live with a portion of it
3739 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
3741 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3743 if (gfp_mask
& __GFP_MEMALLOC
)
3744 return ALLOC_NO_WATERMARKS
;
3745 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3746 return ALLOC_NO_WATERMARKS
;
3747 if (!in_interrupt()) {
3748 if (current
->flags
& PF_MEMALLOC
)
3749 return ALLOC_NO_WATERMARKS
;
3750 else if (oom_reserves_allowed(current
))
3757 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3759 return !!__gfp_pfmemalloc_flags(gfp_mask
);
3763 * Checks whether it makes sense to retry the reclaim to make a forward progress
3764 * for the given allocation request.
3766 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3767 * without success, or when we couldn't even meet the watermark if we
3768 * reclaimed all remaining pages on the LRU lists.
3770 * Returns true if a retry is viable or false to enter the oom path.
3773 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3774 struct alloc_context
*ac
, int alloc_flags
,
3775 bool did_some_progress
, int *no_progress_loops
)
3781 * Costly allocations might have made a progress but this doesn't mean
3782 * their order will become available due to high fragmentation so
3783 * always increment the no progress counter for them
3785 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3786 *no_progress_loops
= 0;
3788 (*no_progress_loops
)++;
3791 * Make sure we converge to OOM if we cannot make any progress
3792 * several times in the row.
3794 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
3795 /* Before OOM, exhaust highatomic_reserve */
3796 return unreserve_highatomic_pageblock(ac
, true);
3800 * Keep reclaiming pages while there is a chance this will lead
3801 * somewhere. If none of the target zones can satisfy our allocation
3802 * request even if all reclaimable pages are considered then we are
3803 * screwed and have to go OOM.
3805 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3807 unsigned long available
;
3808 unsigned long reclaimable
;
3809 unsigned long min_wmark
= min_wmark_pages(zone
);
3812 available
= reclaimable
= zone_reclaimable_pages(zone
);
3813 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3816 * Would the allocation succeed if we reclaimed all
3817 * reclaimable pages?
3819 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
3820 ac_classzone_idx(ac
), alloc_flags
, available
);
3821 trace_reclaim_retry_zone(z
, order
, reclaimable
,
3822 available
, min_wmark
, *no_progress_loops
, wmark
);
3825 * If we didn't make any progress and have a lot of
3826 * dirty + writeback pages then we should wait for
3827 * an IO to complete to slow down the reclaim and
3828 * prevent from pre mature OOM
3830 if (!did_some_progress
) {
3831 unsigned long write_pending
;
3833 write_pending
= zone_page_state_snapshot(zone
,
3834 NR_ZONE_WRITE_PENDING
);
3836 if (2 * write_pending
> reclaimable
) {
3837 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3843 * Memory allocation/reclaim might be called from a WQ
3844 * context and the current implementation of the WQ
3845 * concurrency control doesn't recognize that
3846 * a particular WQ is congested if the worker thread is
3847 * looping without ever sleeping. Therefore we have to
3848 * do a short sleep here rather than calling
3851 if (current
->flags
& PF_WQ_WORKER
)
3852 schedule_timeout_uninterruptible(1);
3864 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
3867 * It's possible that cpuset's mems_allowed and the nodemask from
3868 * mempolicy don't intersect. This should be normally dealt with by
3869 * policy_nodemask(), but it's possible to race with cpuset update in
3870 * such a way the check therein was true, and then it became false
3871 * before we got our cpuset_mems_cookie here.
3872 * This assumes that for all allocations, ac->nodemask can come only
3873 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
3874 * when it does not intersect with the cpuset restrictions) or the
3875 * caller can deal with a violated nodemask.
3877 if (cpusets_enabled() && ac
->nodemask
&&
3878 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
3879 ac
->nodemask
= NULL
;
3884 * When updating a task's mems_allowed or mempolicy nodemask, it is
3885 * possible to race with parallel threads in such a way that our
3886 * allocation can fail while the mask is being updated. If we are about
3887 * to fail, check if the cpuset changed during allocation and if so,
3890 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3896 static inline struct page
*
3897 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3898 struct alloc_context
*ac
)
3900 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3901 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
3902 struct page
*page
= NULL
;
3903 unsigned int alloc_flags
;
3904 unsigned long did_some_progress
;
3905 enum compact_priority compact_priority
;
3906 enum compact_result compact_result
;
3907 int compaction_retries
;
3908 int no_progress_loops
;
3909 unsigned int cpuset_mems_cookie
;
3913 * In the slowpath, we sanity check order to avoid ever trying to
3914 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3915 * be using allocators in order of preference for an area that is
3918 if (order
>= MAX_ORDER
) {
3919 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3924 * We also sanity check to catch abuse of atomic reserves being used by
3925 * callers that are not in atomic context.
3927 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3928 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3929 gfp_mask
&= ~__GFP_ATOMIC
;
3932 compaction_retries
= 0;
3933 no_progress_loops
= 0;
3934 compact_priority
= DEF_COMPACT_PRIORITY
;
3935 cpuset_mems_cookie
= read_mems_allowed_begin();
3938 * The fast path uses conservative alloc_flags to succeed only until
3939 * kswapd needs to be woken up, and to avoid the cost of setting up
3940 * alloc_flags precisely. So we do that now.
3942 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3945 * We need to recalculate the starting point for the zonelist iterator
3946 * because we might have used different nodemask in the fast path, or
3947 * there was a cpuset modification and we are retrying - otherwise we
3948 * could end up iterating over non-eligible zones endlessly.
3950 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3951 ac
->high_zoneidx
, ac
->nodemask
);
3952 if (!ac
->preferred_zoneref
->zone
)
3955 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3956 wake_all_kswapds(order
, ac
);
3959 * The adjusted alloc_flags might result in immediate success, so try
3962 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3967 * For costly allocations, try direct compaction first, as it's likely
3968 * that we have enough base pages and don't need to reclaim. For non-
3969 * movable high-order allocations, do that as well, as compaction will
3970 * try prevent permanent fragmentation by migrating from blocks of the
3972 * Don't try this for allocations that are allowed to ignore
3973 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
3975 if (can_direct_reclaim
&&
3977 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
3978 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
3979 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
3981 INIT_COMPACT_PRIORITY
,
3987 * Checks for costly allocations with __GFP_NORETRY, which
3988 * includes THP page fault allocations
3990 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
3992 * If compaction is deferred for high-order allocations,
3993 * it is because sync compaction recently failed. If
3994 * this is the case and the caller requested a THP
3995 * allocation, we do not want to heavily disrupt the
3996 * system, so we fail the allocation instead of entering
3999 if (compact_result
== COMPACT_DEFERRED
)
4003 * Looks like reclaim/compaction is worth trying, but
4004 * sync compaction could be very expensive, so keep
4005 * using async compaction.
4007 compact_priority
= INIT_COMPACT_PRIORITY
;
4012 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4013 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
4014 wake_all_kswapds(order
, ac
);
4016 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4018 alloc_flags
= reserve_flags
;
4021 * Reset the zonelist iterators if memory policies can be ignored.
4022 * These allocations are high priority and system rather than user
4025 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4026 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
4027 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4028 ac
->high_zoneidx
, ac
->nodemask
);
4031 /* Attempt with potentially adjusted zonelist and alloc_flags */
4032 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4036 /* Caller is not willing to reclaim, we can't balance anything */
4037 if (!can_direct_reclaim
)
4040 /* Avoid recursion of direct reclaim */
4041 if (current
->flags
& PF_MEMALLOC
)
4044 /* Try direct reclaim and then allocating */
4045 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4046 &did_some_progress
);
4050 /* Try direct compaction and then allocating */
4051 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4052 compact_priority
, &compact_result
);
4056 /* Do not loop if specifically requested */
4057 if (gfp_mask
& __GFP_NORETRY
)
4061 * Do not retry costly high order allocations unless they are
4062 * __GFP_RETRY_MAYFAIL
4064 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4067 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4068 did_some_progress
> 0, &no_progress_loops
))
4072 * It doesn't make any sense to retry for the compaction if the order-0
4073 * reclaim is not able to make any progress because the current
4074 * implementation of the compaction depends on the sufficient amount
4075 * of free memory (see __compaction_suitable)
4077 if (did_some_progress
> 0 &&
4078 should_compact_retry(ac
, order
, alloc_flags
,
4079 compact_result
, &compact_priority
,
4080 &compaction_retries
))
4084 /* Deal with possible cpuset update races before we start OOM killing */
4085 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4088 /* Reclaim has failed us, start killing things */
4089 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4093 /* Avoid allocations with no watermarks from looping endlessly */
4094 if (tsk_is_oom_victim(current
) &&
4095 (alloc_flags
== ALLOC_OOM
||
4096 (gfp_mask
& __GFP_NOMEMALLOC
)))
4099 /* Retry as long as the OOM killer is making progress */
4100 if (did_some_progress
) {
4101 no_progress_loops
= 0;
4106 /* Deal with possible cpuset update races before we fail */
4107 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4111 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4114 if (gfp_mask
& __GFP_NOFAIL
) {
4116 * All existing users of the __GFP_NOFAIL are blockable, so warn
4117 * of any new users that actually require GFP_NOWAIT
4119 if (WARN_ON_ONCE(!can_direct_reclaim
))
4123 * PF_MEMALLOC request from this context is rather bizarre
4124 * because we cannot reclaim anything and only can loop waiting
4125 * for somebody to do a work for us
4127 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4130 * non failing costly orders are a hard requirement which we
4131 * are not prepared for much so let's warn about these users
4132 * so that we can identify them and convert them to something
4135 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4138 * Help non-failing allocations by giving them access to memory
4139 * reserves but do not use ALLOC_NO_WATERMARKS because this
4140 * could deplete whole memory reserves which would just make
4141 * the situation worse
4143 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4151 warn_alloc(gfp_mask
, ac
->nodemask
,
4152 "page allocation failure: order:%u", order
);
4157 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4158 int preferred_nid
, nodemask_t
*nodemask
,
4159 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4160 unsigned int *alloc_flags
)
4162 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
4163 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4164 ac
->nodemask
= nodemask
;
4165 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
4167 if (cpusets_enabled()) {
4168 *alloc_mask
|= __GFP_HARDWALL
;
4170 ac
->nodemask
= &cpuset_current_mems_allowed
;
4172 *alloc_flags
|= ALLOC_CPUSET
;
4175 fs_reclaim_acquire(gfp_mask
);
4176 fs_reclaim_release(gfp_mask
);
4178 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4180 if (should_fail_alloc_page(gfp_mask
, order
))
4183 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
4184 *alloc_flags
|= ALLOC_CMA
;
4189 /* Determine whether to spread dirty pages and what the first usable zone */
4190 static inline void finalise_ac(gfp_t gfp_mask
,
4191 unsigned int order
, struct alloc_context
*ac
)
4193 /* Dirty zone balancing only done in the fast path */
4194 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4197 * The preferred zone is used for statistics but crucially it is
4198 * also used as the starting point for the zonelist iterator. It
4199 * may get reset for allocations that ignore memory policies.
4201 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4202 ac
->high_zoneidx
, ac
->nodemask
);
4206 * This is the 'heart' of the zoned buddy allocator.
4209 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4210 nodemask_t
*nodemask
)
4213 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4214 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4215 struct alloc_context ac
= { };
4217 gfp_mask
&= gfp_allowed_mask
;
4218 alloc_mask
= gfp_mask
;
4219 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4222 finalise_ac(gfp_mask
, order
, &ac
);
4224 /* First allocation attempt */
4225 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4230 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4231 * resp. GFP_NOIO which has to be inherited for all allocation requests
4232 * from a particular context which has been marked by
4233 * memalloc_no{fs,io}_{save,restore}.
4235 alloc_mask
= current_gfp_context(gfp_mask
);
4236 ac
.spread_dirty_pages
= false;
4239 * Restore the original nodemask if it was potentially replaced with
4240 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4242 if (unlikely(ac
.nodemask
!= nodemask
))
4243 ac
.nodemask
= nodemask
;
4245 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4248 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4249 unlikely(memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
4250 __free_pages(page
, order
);
4254 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4258 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4261 * Common helper functions.
4263 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4268 * __get_free_pages() returns a 32-bit address, which cannot represent
4271 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
4273 page
= alloc_pages(gfp_mask
, order
);
4276 return (unsigned long) page_address(page
);
4278 EXPORT_SYMBOL(__get_free_pages
);
4280 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4282 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4284 EXPORT_SYMBOL(get_zeroed_page
);
4286 void __free_pages(struct page
*page
, unsigned int order
)
4288 if (put_page_testzero(page
)) {
4290 free_unref_page(page
);
4292 __free_pages_ok(page
, order
);
4296 EXPORT_SYMBOL(__free_pages
);
4298 void free_pages(unsigned long addr
, unsigned int order
)
4301 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4302 __free_pages(virt_to_page((void *)addr
), order
);
4306 EXPORT_SYMBOL(free_pages
);
4310 * An arbitrary-length arbitrary-offset area of memory which resides
4311 * within a 0 or higher order page. Multiple fragments within that page
4312 * are individually refcounted, in the page's reference counter.
4314 * The page_frag functions below provide a simple allocation framework for
4315 * page fragments. This is used by the network stack and network device
4316 * drivers to provide a backing region of memory for use as either an
4317 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4319 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4322 struct page
*page
= NULL
;
4323 gfp_t gfp
= gfp_mask
;
4325 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4326 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4328 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4329 PAGE_FRAG_CACHE_MAX_ORDER
);
4330 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4332 if (unlikely(!page
))
4333 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4335 nc
->va
= page
? page_address(page
) : NULL
;
4340 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4342 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4344 if (page_ref_sub_and_test(page
, count
)) {
4345 unsigned int order
= compound_order(page
);
4348 free_unref_page(page
);
4350 __free_pages_ok(page
, order
);
4353 EXPORT_SYMBOL(__page_frag_cache_drain
);
4355 void *page_frag_alloc(struct page_frag_cache
*nc
,
4356 unsigned int fragsz
, gfp_t gfp_mask
)
4358 unsigned int size
= PAGE_SIZE
;
4362 if (unlikely(!nc
->va
)) {
4364 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4368 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4369 /* if size can vary use size else just use PAGE_SIZE */
4372 /* Even if we own the page, we do not use atomic_set().
4373 * This would break get_page_unless_zero() users.
4375 page_ref_add(page
, size
- 1);
4377 /* reset page count bias and offset to start of new frag */
4378 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4379 nc
->pagecnt_bias
= size
;
4383 offset
= nc
->offset
- fragsz
;
4384 if (unlikely(offset
< 0)) {
4385 page
= virt_to_page(nc
->va
);
4387 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4390 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4391 /* if size can vary use size else just use PAGE_SIZE */
4394 /* OK, page count is 0, we can safely set it */
4395 set_page_count(page
, size
);
4397 /* reset page count bias and offset to start of new frag */
4398 nc
->pagecnt_bias
= size
;
4399 offset
= size
- fragsz
;
4403 nc
->offset
= offset
;
4405 return nc
->va
+ offset
;
4407 EXPORT_SYMBOL(page_frag_alloc
);
4410 * Frees a page fragment allocated out of either a compound or order 0 page.
4412 void page_frag_free(void *addr
)
4414 struct page
*page
= virt_to_head_page(addr
);
4416 if (unlikely(put_page_testzero(page
)))
4417 __free_pages_ok(page
, compound_order(page
));
4419 EXPORT_SYMBOL(page_frag_free
);
4421 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4425 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4426 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4428 split_page(virt_to_page((void *)addr
), order
);
4429 while (used
< alloc_end
) {
4434 return (void *)addr
;
4438 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4439 * @size: the number of bytes to allocate
4440 * @gfp_mask: GFP flags for the allocation
4442 * This function is similar to alloc_pages(), except that it allocates the
4443 * minimum number of pages to satisfy the request. alloc_pages() can only
4444 * allocate memory in power-of-two pages.
4446 * This function is also limited by MAX_ORDER.
4448 * Memory allocated by this function must be released by free_pages_exact().
4450 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4452 unsigned int order
= get_order(size
);
4455 addr
= __get_free_pages(gfp_mask
, order
);
4456 return make_alloc_exact(addr
, order
, size
);
4458 EXPORT_SYMBOL(alloc_pages_exact
);
4461 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4463 * @nid: the preferred node ID where memory should be allocated
4464 * @size: the number of bytes to allocate
4465 * @gfp_mask: GFP flags for the allocation
4467 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4470 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4472 unsigned int order
= get_order(size
);
4473 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4476 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4480 * free_pages_exact - release memory allocated via alloc_pages_exact()
4481 * @virt: the value returned by alloc_pages_exact.
4482 * @size: size of allocation, same value as passed to alloc_pages_exact().
4484 * Release the memory allocated by a previous call to alloc_pages_exact.
4486 void free_pages_exact(void *virt
, size_t size
)
4488 unsigned long addr
= (unsigned long)virt
;
4489 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4491 while (addr
< end
) {
4496 EXPORT_SYMBOL(free_pages_exact
);
4499 * nr_free_zone_pages - count number of pages beyond high watermark
4500 * @offset: The zone index of the highest zone
4502 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4503 * high watermark within all zones at or below a given zone index. For each
4504 * zone, the number of pages is calculated as:
4506 * nr_free_zone_pages = managed_pages - high_pages
4508 static unsigned long nr_free_zone_pages(int offset
)
4513 /* Just pick one node, since fallback list is circular */
4514 unsigned long sum
= 0;
4516 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4518 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4519 unsigned long size
= zone
->managed_pages
;
4520 unsigned long high
= high_wmark_pages(zone
);
4529 * nr_free_buffer_pages - count number of pages beyond high watermark
4531 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4532 * watermark within ZONE_DMA and ZONE_NORMAL.
4534 unsigned long nr_free_buffer_pages(void)
4536 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4538 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4541 * nr_free_pagecache_pages - count number of pages beyond high watermark
4543 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4544 * high watermark within all zones.
4546 unsigned long nr_free_pagecache_pages(void)
4548 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4551 static inline void show_node(struct zone
*zone
)
4553 if (IS_ENABLED(CONFIG_NUMA
))
4554 printk("Node %d ", zone_to_nid(zone
));
4557 long si_mem_available(void)
4560 unsigned long pagecache
;
4561 unsigned long wmark_low
= 0;
4562 unsigned long pages
[NR_LRU_LISTS
];
4566 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4567 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
4570 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4573 * Estimate the amount of memory available for userspace allocations,
4574 * without causing swapping.
4576 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4579 * Not all the page cache can be freed, otherwise the system will
4580 * start swapping. Assume at least half of the page cache, or the
4581 * low watermark worth of cache, needs to stay.
4583 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4584 pagecache
-= min(pagecache
/ 2, wmark_low
);
4585 available
+= pagecache
;
4588 * Part of the reclaimable slab consists of items that are in use,
4589 * and cannot be freed. Cap this estimate at the low watermark.
4591 available
+= global_node_page_state(NR_SLAB_RECLAIMABLE
) -
4592 min(global_node_page_state(NR_SLAB_RECLAIMABLE
) / 2,
4599 EXPORT_SYMBOL_GPL(si_mem_available
);
4601 void si_meminfo(struct sysinfo
*val
)
4603 val
->totalram
= totalram_pages
;
4604 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4605 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
4606 val
->bufferram
= nr_blockdev_pages();
4607 val
->totalhigh
= totalhigh_pages
;
4608 val
->freehigh
= nr_free_highpages();
4609 val
->mem_unit
= PAGE_SIZE
;
4612 EXPORT_SYMBOL(si_meminfo
);
4615 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4617 int zone_type
; /* needs to be signed */
4618 unsigned long managed_pages
= 0;
4619 unsigned long managed_highpages
= 0;
4620 unsigned long free_highpages
= 0;
4621 pg_data_t
*pgdat
= NODE_DATA(nid
);
4623 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4624 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4625 val
->totalram
= managed_pages
;
4626 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4627 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4628 #ifdef CONFIG_HIGHMEM
4629 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4630 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4632 if (is_highmem(zone
)) {
4633 managed_highpages
+= zone
->managed_pages
;
4634 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4637 val
->totalhigh
= managed_highpages
;
4638 val
->freehigh
= free_highpages
;
4640 val
->totalhigh
= managed_highpages
;
4641 val
->freehigh
= free_highpages
;
4643 val
->mem_unit
= PAGE_SIZE
;
4648 * Determine whether the node should be displayed or not, depending on whether
4649 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4651 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
4653 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4657 * no node mask - aka implicit memory numa policy. Do not bother with
4658 * the synchronization - read_mems_allowed_begin - because we do not
4659 * have to be precise here.
4662 nodemask
= &cpuset_current_mems_allowed
;
4664 return !node_isset(nid
, *nodemask
);
4667 #define K(x) ((x) << (PAGE_SHIFT-10))
4669 static void show_migration_types(unsigned char type
)
4671 static const char types
[MIGRATE_TYPES
] = {
4672 [MIGRATE_UNMOVABLE
] = 'U',
4673 [MIGRATE_MOVABLE
] = 'M',
4674 [MIGRATE_RECLAIMABLE
] = 'E',
4675 [MIGRATE_HIGHATOMIC
] = 'H',
4677 [MIGRATE_CMA
] = 'C',
4679 #ifdef CONFIG_MEMORY_ISOLATION
4680 [MIGRATE_ISOLATE
] = 'I',
4683 char tmp
[MIGRATE_TYPES
+ 1];
4687 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4688 if (type
& (1 << i
))
4693 printk(KERN_CONT
"(%s) ", tmp
);
4697 * Show free area list (used inside shift_scroll-lock stuff)
4698 * We also calculate the percentage fragmentation. We do this by counting the
4699 * memory on each free list with the exception of the first item on the list.
4702 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4705 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
4707 unsigned long free_pcp
= 0;
4712 for_each_populated_zone(zone
) {
4713 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4716 for_each_online_cpu(cpu
)
4717 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4720 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4721 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4722 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4723 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4724 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4725 " free:%lu free_pcp:%lu free_cma:%lu\n",
4726 global_node_page_state(NR_ACTIVE_ANON
),
4727 global_node_page_state(NR_INACTIVE_ANON
),
4728 global_node_page_state(NR_ISOLATED_ANON
),
4729 global_node_page_state(NR_ACTIVE_FILE
),
4730 global_node_page_state(NR_INACTIVE_FILE
),
4731 global_node_page_state(NR_ISOLATED_FILE
),
4732 global_node_page_state(NR_UNEVICTABLE
),
4733 global_node_page_state(NR_FILE_DIRTY
),
4734 global_node_page_state(NR_WRITEBACK
),
4735 global_node_page_state(NR_UNSTABLE_NFS
),
4736 global_node_page_state(NR_SLAB_RECLAIMABLE
),
4737 global_node_page_state(NR_SLAB_UNRECLAIMABLE
),
4738 global_node_page_state(NR_FILE_MAPPED
),
4739 global_node_page_state(NR_SHMEM
),
4740 global_zone_page_state(NR_PAGETABLE
),
4741 global_zone_page_state(NR_BOUNCE
),
4742 global_zone_page_state(NR_FREE_PAGES
),
4744 global_zone_page_state(NR_FREE_CMA_PAGES
));
4746 for_each_online_pgdat(pgdat
) {
4747 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
4751 " active_anon:%lukB"
4752 " inactive_anon:%lukB"
4753 " active_file:%lukB"
4754 " inactive_file:%lukB"
4755 " unevictable:%lukB"
4756 " isolated(anon):%lukB"
4757 " isolated(file):%lukB"
4762 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4764 " shmem_pmdmapped: %lukB"
4767 " writeback_tmp:%lukB"
4769 " all_unreclaimable? %s"
4772 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4773 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4774 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4775 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4776 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4777 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4778 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4779 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4780 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4781 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4782 K(node_page_state(pgdat
, NR_SHMEM
)),
4783 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4784 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4785 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4787 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4789 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4790 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4791 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
4795 for_each_populated_zone(zone
) {
4798 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4802 for_each_online_cpu(cpu
)
4803 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4812 " active_anon:%lukB"
4813 " inactive_anon:%lukB"
4814 " active_file:%lukB"
4815 " inactive_file:%lukB"
4816 " unevictable:%lukB"
4817 " writepending:%lukB"
4821 " kernel_stack:%lukB"
4829 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4830 K(min_wmark_pages(zone
)),
4831 K(low_wmark_pages(zone
)),
4832 K(high_wmark_pages(zone
)),
4833 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4834 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4835 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4836 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4837 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4838 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4839 K(zone
->present_pages
),
4840 K(zone
->managed_pages
),
4841 K(zone_page_state(zone
, NR_MLOCK
)),
4842 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4843 K(zone_page_state(zone
, NR_PAGETABLE
)),
4844 K(zone_page_state(zone
, NR_BOUNCE
)),
4846 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4847 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4848 printk("lowmem_reserve[]:");
4849 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4850 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
4851 printk(KERN_CONT
"\n");
4854 for_each_populated_zone(zone
) {
4856 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4857 unsigned char types
[MAX_ORDER
];
4859 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4862 printk(KERN_CONT
"%s: ", zone
->name
);
4864 spin_lock_irqsave(&zone
->lock
, flags
);
4865 for (order
= 0; order
< MAX_ORDER
; order
++) {
4866 struct free_area
*area
= &zone
->free_area
[order
];
4869 nr
[order
] = area
->nr_free
;
4870 total
+= nr
[order
] << order
;
4873 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4874 if (!list_empty(&area
->free_list
[type
]))
4875 types
[order
] |= 1 << type
;
4878 spin_unlock_irqrestore(&zone
->lock
, flags
);
4879 for (order
= 0; order
< MAX_ORDER
; order
++) {
4880 printk(KERN_CONT
"%lu*%lukB ",
4881 nr
[order
], K(1UL) << order
);
4883 show_migration_types(types
[order
]);
4885 printk(KERN_CONT
"= %lukB\n", K(total
));
4888 hugetlb_show_meminfo();
4890 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4892 show_swap_cache_info();
4895 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4897 zoneref
->zone
= zone
;
4898 zoneref
->zone_idx
= zone_idx(zone
);
4902 * Builds allocation fallback zone lists.
4904 * Add all populated zones of a node to the zonelist.
4906 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
4909 enum zone_type zone_type
= MAX_NR_ZONES
;
4914 zone
= pgdat
->node_zones
+ zone_type
;
4915 if (managed_zone(zone
)) {
4916 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
4917 check_highest_zone(zone_type
);
4919 } while (zone_type
);
4926 static int __parse_numa_zonelist_order(char *s
)
4929 * We used to support different zonlists modes but they turned
4930 * out to be just not useful. Let's keep the warning in place
4931 * if somebody still use the cmd line parameter so that we do
4932 * not fail it silently
4934 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
4935 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
4941 static __init
int setup_numa_zonelist_order(char *s
)
4946 return __parse_numa_zonelist_order(s
);
4948 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4950 char numa_zonelist_order
[] = "Node";
4953 * sysctl handler for numa_zonelist_order
4955 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4956 void __user
*buffer
, size_t *length
,
4963 return proc_dostring(table
, write
, buffer
, length
, ppos
);
4964 str
= memdup_user_nul(buffer
, 16);
4966 return PTR_ERR(str
);
4968 ret
= __parse_numa_zonelist_order(str
);
4974 #define MAX_NODE_LOAD (nr_online_nodes)
4975 static int node_load
[MAX_NUMNODES
];
4978 * find_next_best_node - find the next node that should appear in a given node's fallback list
4979 * @node: node whose fallback list we're appending
4980 * @used_node_mask: nodemask_t of already used nodes
4982 * We use a number of factors to determine which is the next node that should
4983 * appear on a given node's fallback list. The node should not have appeared
4984 * already in @node's fallback list, and it should be the next closest node
4985 * according to the distance array (which contains arbitrary distance values
4986 * from each node to each node in the system), and should also prefer nodes
4987 * with no CPUs, since presumably they'll have very little allocation pressure
4988 * on them otherwise.
4989 * It returns -1 if no node is found.
4991 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4994 int min_val
= INT_MAX
;
4995 int best_node
= NUMA_NO_NODE
;
4996 const struct cpumask
*tmp
= cpumask_of_node(0);
4998 /* Use the local node if we haven't already */
4999 if (!node_isset(node
, *used_node_mask
)) {
5000 node_set(node
, *used_node_mask
);
5004 for_each_node_state(n
, N_MEMORY
) {
5006 /* Don't want a node to appear more than once */
5007 if (node_isset(n
, *used_node_mask
))
5010 /* Use the distance array to find the distance */
5011 val
= node_distance(node
, n
);
5013 /* Penalize nodes under us ("prefer the next node") */
5016 /* Give preference to headless and unused nodes */
5017 tmp
= cpumask_of_node(n
);
5018 if (!cpumask_empty(tmp
))
5019 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
5021 /* Slight preference for less loaded node */
5022 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
5023 val
+= node_load
[n
];
5025 if (val
< min_val
) {
5032 node_set(best_node
, *used_node_mask
);
5039 * Build zonelists ordered by node and zones within node.
5040 * This results in maximum locality--normal zone overflows into local
5041 * DMA zone, if any--but risks exhausting DMA zone.
5043 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5046 struct zoneref
*zonerefs
;
5049 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5051 for (i
= 0; i
< nr_nodes
; i
++) {
5054 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5056 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5057 zonerefs
+= nr_zones
;
5059 zonerefs
->zone
= NULL
;
5060 zonerefs
->zone_idx
= 0;
5064 * Build gfp_thisnode zonelists
5066 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5068 struct zoneref
*zonerefs
;
5071 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5072 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5073 zonerefs
+= nr_zones
;
5074 zonerefs
->zone
= NULL
;
5075 zonerefs
->zone_idx
= 0;
5079 * Build zonelists ordered by zone and nodes within zones.
5080 * This results in conserving DMA zone[s] until all Normal memory is
5081 * exhausted, but results in overflowing to remote node while memory
5082 * may still exist in local DMA zone.
5085 static void build_zonelists(pg_data_t
*pgdat
)
5087 static int node_order
[MAX_NUMNODES
];
5088 int node
, load
, nr_nodes
= 0;
5089 nodemask_t used_mask
;
5090 int local_node
, prev_node
;
5092 /* NUMA-aware ordering of nodes */
5093 local_node
= pgdat
->node_id
;
5094 load
= nr_online_nodes
;
5095 prev_node
= local_node
;
5096 nodes_clear(used_mask
);
5098 memset(node_order
, 0, sizeof(node_order
));
5099 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5101 * We don't want to pressure a particular node.
5102 * So adding penalty to the first node in same
5103 * distance group to make it round-robin.
5105 if (node_distance(local_node
, node
) !=
5106 node_distance(local_node
, prev_node
))
5107 node_load
[node
] = load
;
5109 node_order
[nr_nodes
++] = node
;
5114 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5115 build_thisnode_zonelists(pgdat
);
5118 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5120 * Return node id of node used for "local" allocations.
5121 * I.e., first node id of first zone in arg node's generic zonelist.
5122 * Used for initializing percpu 'numa_mem', which is used primarily
5123 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5125 int local_memory_node(int node
)
5129 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5130 gfp_zone(GFP_KERNEL
),
5132 return z
->zone
->node
;
5136 static void setup_min_unmapped_ratio(void);
5137 static void setup_min_slab_ratio(void);
5138 #else /* CONFIG_NUMA */
5140 static void build_zonelists(pg_data_t
*pgdat
)
5142 int node
, local_node
;
5143 struct zoneref
*zonerefs
;
5146 local_node
= pgdat
->node_id
;
5148 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5149 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5150 zonerefs
+= nr_zones
;
5153 * Now we build the zonelist so that it contains the zones
5154 * of all the other nodes.
5155 * We don't want to pressure a particular node, so when
5156 * building the zones for node N, we make sure that the
5157 * zones coming right after the local ones are those from
5158 * node N+1 (modulo N)
5160 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5161 if (!node_online(node
))
5163 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5164 zonerefs
+= nr_zones
;
5166 for (node
= 0; node
< local_node
; node
++) {
5167 if (!node_online(node
))
5169 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5170 zonerefs
+= nr_zones
;
5173 zonerefs
->zone
= NULL
;
5174 zonerefs
->zone_idx
= 0;
5177 #endif /* CONFIG_NUMA */
5180 * Boot pageset table. One per cpu which is going to be used for all
5181 * zones and all nodes. The parameters will be set in such a way
5182 * that an item put on a list will immediately be handed over to
5183 * the buddy list. This is safe since pageset manipulation is done
5184 * with interrupts disabled.
5186 * The boot_pagesets must be kept even after bootup is complete for
5187 * unused processors and/or zones. They do play a role for bootstrapping
5188 * hotplugged processors.
5190 * zoneinfo_show() and maybe other functions do
5191 * not check if the processor is online before following the pageset pointer.
5192 * Other parts of the kernel may not check if the zone is available.
5194 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5195 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5196 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5198 static void __build_all_zonelists(void *data
)
5201 int __maybe_unused cpu
;
5202 pg_data_t
*self
= data
;
5203 static DEFINE_SPINLOCK(lock
);
5208 memset(node_load
, 0, sizeof(node_load
));
5212 * This node is hotadded and no memory is yet present. So just
5213 * building zonelists is fine - no need to touch other nodes.
5215 if (self
&& !node_online(self
->node_id
)) {
5216 build_zonelists(self
);
5218 for_each_online_node(nid
) {
5219 pg_data_t
*pgdat
= NODE_DATA(nid
);
5221 build_zonelists(pgdat
);
5224 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5226 * We now know the "local memory node" for each node--
5227 * i.e., the node of the first zone in the generic zonelist.
5228 * Set up numa_mem percpu variable for on-line cpus. During
5229 * boot, only the boot cpu should be on-line; we'll init the
5230 * secondary cpus' numa_mem as they come on-line. During
5231 * node/memory hotplug, we'll fixup all on-line cpus.
5233 for_each_online_cpu(cpu
)
5234 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5241 static noinline
void __init
5242 build_all_zonelists_init(void)
5246 __build_all_zonelists(NULL
);
5249 * Initialize the boot_pagesets that are going to be used
5250 * for bootstrapping processors. The real pagesets for
5251 * each zone will be allocated later when the per cpu
5252 * allocator is available.
5254 * boot_pagesets are used also for bootstrapping offline
5255 * cpus if the system is already booted because the pagesets
5256 * are needed to initialize allocators on a specific cpu too.
5257 * F.e. the percpu allocator needs the page allocator which
5258 * needs the percpu allocator in order to allocate its pagesets
5259 * (a chicken-egg dilemma).
5261 for_each_possible_cpu(cpu
)
5262 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5264 mminit_verify_zonelist();
5265 cpuset_init_current_mems_allowed();
5269 * unless system_state == SYSTEM_BOOTING.
5271 * __ref due to call of __init annotated helper build_all_zonelists_init
5272 * [protected by SYSTEM_BOOTING].
5274 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
5276 if (system_state
== SYSTEM_BOOTING
) {
5277 build_all_zonelists_init();
5279 __build_all_zonelists(pgdat
);
5280 /* cpuset refresh routine should be here */
5282 vm_total_pages
= nr_free_pagecache_pages();
5284 * Disable grouping by mobility if the number of pages in the
5285 * system is too low to allow the mechanism to work. It would be
5286 * more accurate, but expensive to check per-zone. This check is
5287 * made on memory-hotadd so a system can start with mobility
5288 * disabled and enable it later
5290 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5291 page_group_by_mobility_disabled
= 1;
5293 page_group_by_mobility_disabled
= 0;
5295 pr_info("Built %i zonelists, mobility grouping %s. Total pages: %ld\n",
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
);
5397 __init_single_pfn(pfn
, zone
, nid
);
5402 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5404 unsigned int order
, t
;
5405 for_each_migratetype_order(order
, t
) {
5406 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5407 zone
->free_area
[order
].nr_free
= 0;
5411 #ifndef __HAVE_ARCH_MEMMAP_INIT
5412 #define memmap_init(size, nid, zone, start_pfn) \
5413 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5416 static int zone_batchsize(struct zone
*zone
)
5422 * The per-cpu-pages pools are set to around 1000th of the
5423 * size of the zone. But no more than 1/2 of a meg.
5425 * OK, so we don't know how big the cache is. So guess.
5427 batch
= zone
->managed_pages
/ 1024;
5428 if (batch
* PAGE_SIZE
> 512 * 1024)
5429 batch
= (512 * 1024) / PAGE_SIZE
;
5430 batch
/= 4; /* We effectively *= 4 below */
5435 * Clamp the batch to a 2^n - 1 value. Having a power
5436 * of 2 value was found to be more likely to have
5437 * suboptimal cache aliasing properties in some cases.
5439 * For example if 2 tasks are alternately allocating
5440 * batches of pages, one task can end up with a lot
5441 * of pages of one half of the possible page colors
5442 * and the other with pages of the other colors.
5444 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5449 /* The deferral and batching of frees should be suppressed under NOMMU
5452 * The problem is that NOMMU needs to be able to allocate large chunks
5453 * of contiguous memory as there's no hardware page translation to
5454 * assemble apparent contiguous memory from discontiguous pages.
5456 * Queueing large contiguous runs of pages for batching, however,
5457 * causes the pages to actually be freed in smaller chunks. As there
5458 * can be a significant delay between the individual batches being
5459 * recycled, this leads to the once large chunks of space being
5460 * fragmented and becoming unavailable for high-order allocations.
5467 * pcp->high and pcp->batch values are related and dependent on one another:
5468 * ->batch must never be higher then ->high.
5469 * The following function updates them in a safe manner without read side
5472 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5473 * those fields changing asynchronously (acording the the above rule).
5475 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5476 * outside of boot time (or some other assurance that no concurrent updaters
5479 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5480 unsigned long batch
)
5482 /* start with a fail safe value for batch */
5486 /* Update high, then batch, in order */
5493 /* a companion to pageset_set_high() */
5494 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5496 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5499 static void pageset_init(struct per_cpu_pageset
*p
)
5501 struct per_cpu_pages
*pcp
;
5504 memset(p
, 0, sizeof(*p
));
5508 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5509 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5512 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5515 pageset_set_batch(p
, batch
);
5519 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5520 * to the value high for the pageset p.
5522 static void pageset_set_high(struct per_cpu_pageset
*p
,
5525 unsigned long batch
= max(1UL, high
/ 4);
5526 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5527 batch
= PAGE_SHIFT
* 8;
5529 pageset_update(&p
->pcp
, high
, batch
);
5532 static void pageset_set_high_and_batch(struct zone
*zone
,
5533 struct per_cpu_pageset
*pcp
)
5535 if (percpu_pagelist_fraction
)
5536 pageset_set_high(pcp
,
5537 (zone
->managed_pages
/
5538 percpu_pagelist_fraction
));
5540 pageset_set_batch(pcp
, zone_batchsize(zone
));
5543 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5545 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5548 pageset_set_high_and_batch(zone
, pcp
);
5551 void __meminit
setup_zone_pageset(struct zone
*zone
)
5554 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5555 for_each_possible_cpu(cpu
)
5556 zone_pageset_init(zone
, cpu
);
5560 * Allocate per cpu pagesets and initialize them.
5561 * Before this call only boot pagesets were available.
5563 void __init
setup_per_cpu_pageset(void)
5565 struct pglist_data
*pgdat
;
5568 for_each_populated_zone(zone
)
5569 setup_zone_pageset(zone
);
5571 for_each_online_pgdat(pgdat
)
5572 pgdat
->per_cpu_nodestats
=
5573 alloc_percpu(struct per_cpu_nodestat
);
5576 static __meminit
void zone_pcp_init(struct zone
*zone
)
5579 * per cpu subsystem is not up at this point. The following code
5580 * relies on the ability of the linker to provide the
5581 * offset of a (static) per cpu variable into the per cpu area.
5583 zone
->pageset
= &boot_pageset
;
5585 if (populated_zone(zone
))
5586 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5587 zone
->name
, zone
->present_pages
,
5588 zone_batchsize(zone
));
5591 void __meminit
init_currently_empty_zone(struct zone
*zone
,
5592 unsigned long zone_start_pfn
,
5595 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5597 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5599 zone
->zone_start_pfn
= zone_start_pfn
;
5601 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5602 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5604 (unsigned long)zone_idx(zone
),
5605 zone_start_pfn
, (zone_start_pfn
+ size
));
5607 zone_init_free_lists(zone
);
5608 zone
->initialized
= 1;
5611 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5612 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5615 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5617 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5618 struct mminit_pfnnid_cache
*state
)
5620 unsigned long start_pfn
, end_pfn
;
5623 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5624 return state
->last_nid
;
5626 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5628 state
->last_start
= start_pfn
;
5629 state
->last_end
= end_pfn
;
5630 state
->last_nid
= nid
;
5635 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5638 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5639 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5640 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5642 * If an architecture guarantees that all ranges registered contain no holes
5643 * and may be freed, this this function may be used instead of calling
5644 * memblock_free_early_nid() manually.
5646 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5648 unsigned long start_pfn
, end_pfn
;
5651 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5652 start_pfn
= min(start_pfn
, max_low_pfn
);
5653 end_pfn
= min(end_pfn
, max_low_pfn
);
5655 if (start_pfn
< end_pfn
)
5656 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5657 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5663 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5664 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5666 * If an architecture guarantees that all ranges registered contain no holes and may
5667 * be freed, this function may be used instead of calling memory_present() manually.
5669 void __init
sparse_memory_present_with_active_regions(int nid
)
5671 unsigned long start_pfn
, end_pfn
;
5674 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5675 memory_present(this_nid
, start_pfn
, end_pfn
);
5679 * get_pfn_range_for_nid - Return the start and end page frames for a node
5680 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5681 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5682 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5684 * It returns the start and end page frame of a node based on information
5685 * provided by memblock_set_node(). If called for a node
5686 * with no available memory, a warning is printed and the start and end
5689 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5690 unsigned long *start_pfn
, unsigned long *end_pfn
)
5692 unsigned long this_start_pfn
, this_end_pfn
;
5698 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5699 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5700 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5703 if (*start_pfn
== -1UL)
5708 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5709 * assumption is made that zones within a node are ordered in monotonic
5710 * increasing memory addresses so that the "highest" populated zone is used
5712 static void __init
find_usable_zone_for_movable(void)
5715 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5716 if (zone_index
== ZONE_MOVABLE
)
5719 if (arch_zone_highest_possible_pfn
[zone_index
] >
5720 arch_zone_lowest_possible_pfn
[zone_index
])
5724 VM_BUG_ON(zone_index
== -1);
5725 movable_zone
= zone_index
;
5729 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5730 * because it is sized independent of architecture. Unlike the other zones,
5731 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5732 * in each node depending on the size of each node and how evenly kernelcore
5733 * is distributed. This helper function adjusts the zone ranges
5734 * provided by the architecture for a given node by using the end of the
5735 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5736 * zones within a node are in order of monotonic increases memory addresses
5738 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5739 unsigned long zone_type
,
5740 unsigned long node_start_pfn
,
5741 unsigned long node_end_pfn
,
5742 unsigned long *zone_start_pfn
,
5743 unsigned long *zone_end_pfn
)
5745 /* Only adjust if ZONE_MOVABLE is on this node */
5746 if (zone_movable_pfn
[nid
]) {
5747 /* Size ZONE_MOVABLE */
5748 if (zone_type
== ZONE_MOVABLE
) {
5749 *zone_start_pfn
= zone_movable_pfn
[nid
];
5750 *zone_end_pfn
= min(node_end_pfn
,
5751 arch_zone_highest_possible_pfn
[movable_zone
]);
5753 /* Adjust for ZONE_MOVABLE starting within this range */
5754 } else if (!mirrored_kernelcore
&&
5755 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
5756 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5757 *zone_end_pfn
= zone_movable_pfn
[nid
];
5759 /* Check if this whole range is within ZONE_MOVABLE */
5760 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5761 *zone_start_pfn
= *zone_end_pfn
;
5766 * Return the number of pages a zone spans in a node, including holes
5767 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5769 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5770 unsigned long zone_type
,
5771 unsigned long node_start_pfn
,
5772 unsigned long node_end_pfn
,
5773 unsigned long *zone_start_pfn
,
5774 unsigned long *zone_end_pfn
,
5775 unsigned long *ignored
)
5777 /* When hotadd a new node from cpu_up(), the node should be empty */
5778 if (!node_start_pfn
&& !node_end_pfn
)
5781 /* Get the start and end of the zone */
5782 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5783 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5784 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5785 node_start_pfn
, node_end_pfn
,
5786 zone_start_pfn
, zone_end_pfn
);
5788 /* Check that this node has pages within the zone's required range */
5789 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5792 /* Move the zone boundaries inside the node if necessary */
5793 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5794 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5796 /* Return the spanned pages */
5797 return *zone_end_pfn
- *zone_start_pfn
;
5801 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5802 * then all holes in the requested range will be accounted for.
5804 unsigned long __meminit
__absent_pages_in_range(int nid
,
5805 unsigned long range_start_pfn
,
5806 unsigned long range_end_pfn
)
5808 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5809 unsigned long start_pfn
, end_pfn
;
5812 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5813 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5814 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5815 nr_absent
-= end_pfn
- start_pfn
;
5821 * absent_pages_in_range - Return number of page frames in holes within a range
5822 * @start_pfn: The start PFN to start searching for holes
5823 * @end_pfn: The end PFN to stop searching for holes
5825 * It returns the number of pages frames in memory holes within a range.
5827 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5828 unsigned long end_pfn
)
5830 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5833 /* Return the number of page frames in holes in a zone on a node */
5834 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5835 unsigned long zone_type
,
5836 unsigned long node_start_pfn
,
5837 unsigned long node_end_pfn
,
5838 unsigned long *ignored
)
5840 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5841 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5842 unsigned long zone_start_pfn
, zone_end_pfn
;
5843 unsigned long nr_absent
;
5845 /* When hotadd a new node from cpu_up(), the node should be empty */
5846 if (!node_start_pfn
&& !node_end_pfn
)
5849 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5850 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5852 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5853 node_start_pfn
, node_end_pfn
,
5854 &zone_start_pfn
, &zone_end_pfn
);
5855 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5858 * ZONE_MOVABLE handling.
5859 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5862 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
5863 unsigned long start_pfn
, end_pfn
;
5864 struct memblock_region
*r
;
5866 for_each_memblock(memory
, r
) {
5867 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5868 zone_start_pfn
, zone_end_pfn
);
5869 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5870 zone_start_pfn
, zone_end_pfn
);
5872 if (zone_type
== ZONE_MOVABLE
&&
5873 memblock_is_mirror(r
))
5874 nr_absent
+= end_pfn
- start_pfn
;
5876 if (zone_type
== ZONE_NORMAL
&&
5877 !memblock_is_mirror(r
))
5878 nr_absent
+= end_pfn
- start_pfn
;
5885 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5886 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5887 unsigned long zone_type
,
5888 unsigned long node_start_pfn
,
5889 unsigned long node_end_pfn
,
5890 unsigned long *zone_start_pfn
,
5891 unsigned long *zone_end_pfn
,
5892 unsigned long *zones_size
)
5896 *zone_start_pfn
= node_start_pfn
;
5897 for (zone
= 0; zone
< zone_type
; zone
++)
5898 *zone_start_pfn
+= zones_size
[zone
];
5900 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5902 return zones_size
[zone_type
];
5905 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5906 unsigned long zone_type
,
5907 unsigned long node_start_pfn
,
5908 unsigned long node_end_pfn
,
5909 unsigned long *zholes_size
)
5914 return zholes_size
[zone_type
];
5917 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5919 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5920 unsigned long node_start_pfn
,
5921 unsigned long node_end_pfn
,
5922 unsigned long *zones_size
,
5923 unsigned long *zholes_size
)
5925 unsigned long realtotalpages
= 0, totalpages
= 0;
5928 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5929 struct zone
*zone
= pgdat
->node_zones
+ i
;
5930 unsigned long zone_start_pfn
, zone_end_pfn
;
5931 unsigned long size
, real_size
;
5933 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5939 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5940 node_start_pfn
, node_end_pfn
,
5943 zone
->zone_start_pfn
= zone_start_pfn
;
5945 zone
->zone_start_pfn
= 0;
5946 zone
->spanned_pages
= size
;
5947 zone
->present_pages
= real_size
;
5950 realtotalpages
+= real_size
;
5953 pgdat
->node_spanned_pages
= totalpages
;
5954 pgdat
->node_present_pages
= realtotalpages
;
5955 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5959 #ifndef CONFIG_SPARSEMEM
5961 * Calculate the size of the zone->blockflags rounded to an unsigned long
5962 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5963 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5964 * round what is now in bits to nearest long in bits, then return it in
5967 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5969 unsigned long usemapsize
;
5971 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5972 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5973 usemapsize
= usemapsize
>> pageblock_order
;
5974 usemapsize
*= NR_PAGEBLOCK_BITS
;
5975 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5977 return usemapsize
/ 8;
5980 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5982 unsigned long zone_start_pfn
,
5983 unsigned long zonesize
)
5985 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5986 zone
->pageblock_flags
= NULL
;
5988 zone
->pageblock_flags
=
5989 memblock_virt_alloc_node_nopanic(usemapsize
,
5993 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5994 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5995 #endif /* CONFIG_SPARSEMEM */
5997 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5999 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6000 void __paginginit
set_pageblock_order(void)
6004 /* Check that pageblock_nr_pages has not already been setup */
6005 if (pageblock_order
)
6008 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6009 order
= HUGETLB_PAGE_ORDER
;
6011 order
= MAX_ORDER
- 1;
6014 * Assume the largest contiguous order of interest is a huge page.
6015 * This value may be variable depending on boot parameters on IA64 and
6018 pageblock_order
= order
;
6020 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6023 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6024 * is unused as pageblock_order is set at compile-time. See
6025 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6028 void __paginginit
set_pageblock_order(void)
6032 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6034 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
6035 unsigned long present_pages
)
6037 unsigned long pages
= spanned_pages
;
6040 * Provide a more accurate estimation if there are holes within
6041 * the zone and SPARSEMEM is in use. If there are holes within the
6042 * zone, each populated memory region may cost us one or two extra
6043 * memmap pages due to alignment because memmap pages for each
6044 * populated regions may not be naturally aligned on page boundary.
6045 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6047 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6048 IS_ENABLED(CONFIG_SPARSEMEM
))
6049 pages
= present_pages
;
6051 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6055 * Set up the zone data structures:
6056 * - mark all pages reserved
6057 * - mark all memory queues empty
6058 * - clear the memory bitmaps
6060 * NOTE: pgdat should get zeroed by caller.
6062 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
6065 int nid
= pgdat
->node_id
;
6067 pgdat_resize_init(pgdat
);
6068 #ifdef CONFIG_NUMA_BALANCING
6069 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
6070 pgdat
->numabalancing_migrate_nr_pages
= 0;
6071 pgdat
->numabalancing_migrate_next_window
= jiffies
;
6073 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6074 spin_lock_init(&pgdat
->split_queue_lock
);
6075 INIT_LIST_HEAD(&pgdat
->split_queue
);
6076 pgdat
->split_queue_len
= 0;
6078 init_waitqueue_head(&pgdat
->kswapd_wait
);
6079 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6080 #ifdef CONFIG_COMPACTION
6081 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6083 pgdat_page_ext_init(pgdat
);
6084 spin_lock_init(&pgdat
->lru_lock
);
6085 lruvec_init(node_lruvec(pgdat
));
6087 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6089 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6090 struct zone
*zone
= pgdat
->node_zones
+ j
;
6091 unsigned long size
, realsize
, freesize
, memmap_pages
;
6092 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6094 size
= zone
->spanned_pages
;
6095 realsize
= freesize
= zone
->present_pages
;
6098 * Adjust freesize so that it accounts for how much memory
6099 * is used by this zone for memmap. This affects the watermark
6100 * and per-cpu initialisations
6102 memmap_pages
= calc_memmap_size(size
, realsize
);
6103 if (!is_highmem_idx(j
)) {
6104 if (freesize
>= memmap_pages
) {
6105 freesize
-= memmap_pages
;
6108 " %s zone: %lu pages used for memmap\n",
6109 zone_names
[j
], memmap_pages
);
6111 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6112 zone_names
[j
], memmap_pages
, freesize
);
6115 /* Account for reserved pages */
6116 if (j
== 0 && freesize
> dma_reserve
) {
6117 freesize
-= dma_reserve
;
6118 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6119 zone_names
[0], dma_reserve
);
6122 if (!is_highmem_idx(j
))
6123 nr_kernel_pages
+= freesize
;
6124 /* Charge for highmem memmap if there are enough kernel pages */
6125 else if (nr_kernel_pages
> memmap_pages
* 2)
6126 nr_kernel_pages
-= memmap_pages
;
6127 nr_all_pages
+= freesize
;
6130 * Set an approximate value for lowmem here, it will be adjusted
6131 * when the bootmem allocator frees pages into the buddy system.
6132 * And all highmem pages will be managed by the buddy system.
6134 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
6138 zone
->name
= zone_names
[j
];
6139 zone
->zone_pgdat
= pgdat
;
6140 spin_lock_init(&zone
->lock
);
6141 zone_seqlock_init(zone
);
6142 zone_pcp_init(zone
);
6147 set_pageblock_order();
6148 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6149 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6150 memmap_init(size
, nid
, j
, zone_start_pfn
);
6154 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6155 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6157 unsigned long __maybe_unused start
= 0;
6158 unsigned long __maybe_unused offset
= 0;
6160 /* Skip empty nodes */
6161 if (!pgdat
->node_spanned_pages
)
6164 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6165 offset
= pgdat
->node_start_pfn
- start
;
6166 /* ia64 gets its own node_mem_map, before this, without bootmem */
6167 if (!pgdat
->node_mem_map
) {
6168 unsigned long size
, end
;
6172 * The zone's endpoints aren't required to be MAX_ORDER
6173 * aligned but the node_mem_map endpoints must be in order
6174 * for the buddy allocator to function correctly.
6176 end
= pgdat_end_pfn(pgdat
);
6177 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6178 size
= (end
- start
) * sizeof(struct page
);
6179 map
= alloc_remap(pgdat
->node_id
, size
);
6181 map
= memblock_virt_alloc_node_nopanic(size
,
6183 pgdat
->node_mem_map
= map
+ offset
;
6185 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6186 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
6187 (unsigned long)pgdat
->node_mem_map
);
6188 #ifndef CONFIG_NEED_MULTIPLE_NODES
6190 * With no DISCONTIG, the global mem_map is just set as node 0's
6192 if (pgdat
== NODE_DATA(0)) {
6193 mem_map
= NODE_DATA(0)->node_mem_map
;
6194 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6195 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6197 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6202 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
6203 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6205 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6206 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6208 pg_data_t
*pgdat
= NODE_DATA(nid
);
6209 unsigned long start_pfn
= 0;
6210 unsigned long end_pfn
= 0;
6212 /* pg_data_t should be reset to zero when it's allocated */
6213 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6215 pgdat
->node_id
= nid
;
6216 pgdat
->node_start_pfn
= node_start_pfn
;
6217 pgdat
->per_cpu_nodestats
= NULL
;
6218 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6219 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6220 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6221 (u64
)start_pfn
<< PAGE_SHIFT
,
6222 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6224 start_pfn
= node_start_pfn
;
6226 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6227 zones_size
, zholes_size
);
6229 alloc_node_mem_map(pgdat
);
6231 reset_deferred_meminit(pgdat
);
6232 free_area_init_core(pgdat
);
6235 #ifdef CONFIG_HAVE_MEMBLOCK
6237 * Only struct pages that are backed by physical memory are zeroed and
6238 * initialized by going through __init_single_page(). But, there are some
6239 * struct pages which are reserved in memblock allocator and their fields
6240 * may be accessed (for example page_to_pfn() on some configuration accesses
6241 * flags). We must explicitly zero those struct pages.
6243 void __paginginit
zero_resv_unavail(void)
6245 phys_addr_t start
, end
;
6250 * Loop through ranges that are reserved, but do not have reported
6251 * physical memory backing.
6254 for_each_resv_unavail_range(i
, &start
, &end
) {
6255 for (pfn
= PFN_DOWN(start
); pfn
< PFN_UP(end
); pfn
++) {
6256 mm_zero_struct_page(pfn_to_page(pfn
));
6262 * Struct pages that do not have backing memory. This could be because
6263 * firmware is using some of this memory, or for some other reasons.
6264 * Once memblock is changed so such behaviour is not allowed: i.e.
6265 * list of "reserved" memory must be a subset of list of "memory", then
6266 * this code can be removed.
6269 pr_info("Reserved but unavailable: %lld pages", pgcnt
);
6271 #endif /* CONFIG_HAVE_MEMBLOCK */
6273 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6275 #if MAX_NUMNODES > 1
6277 * Figure out the number of possible node ids.
6279 void __init
setup_nr_node_ids(void)
6281 unsigned int highest
;
6283 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6284 nr_node_ids
= highest
+ 1;
6289 * node_map_pfn_alignment - determine the maximum internode alignment
6291 * This function should be called after node map is populated and sorted.
6292 * It calculates the maximum power of two alignment which can distinguish
6295 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6296 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6297 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6298 * shifted, 1GiB is enough and this function will indicate so.
6300 * This is used to test whether pfn -> nid mapping of the chosen memory
6301 * model has fine enough granularity to avoid incorrect mapping for the
6302 * populated node map.
6304 * Returns the determined alignment in pfn's. 0 if there is no alignment
6305 * requirement (single node).
6307 unsigned long __init
node_map_pfn_alignment(void)
6309 unsigned long accl_mask
= 0, last_end
= 0;
6310 unsigned long start
, end
, mask
;
6314 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6315 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6322 * Start with a mask granular enough to pin-point to the
6323 * start pfn and tick off bits one-by-one until it becomes
6324 * too coarse to separate the current node from the last.
6326 mask
= ~((1 << __ffs(start
)) - 1);
6327 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6330 /* accumulate all internode masks */
6334 /* convert mask to number of pages */
6335 return ~accl_mask
+ 1;
6338 /* Find the lowest pfn for a node */
6339 static unsigned long __init
find_min_pfn_for_node(int nid
)
6341 unsigned long min_pfn
= ULONG_MAX
;
6342 unsigned long start_pfn
;
6345 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6346 min_pfn
= min(min_pfn
, start_pfn
);
6348 if (min_pfn
== ULONG_MAX
) {
6349 pr_warn("Could not find start_pfn for node %d\n", nid
);
6357 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6359 * It returns the minimum PFN based on information provided via
6360 * memblock_set_node().
6362 unsigned long __init
find_min_pfn_with_active_regions(void)
6364 return find_min_pfn_for_node(MAX_NUMNODES
);
6368 * early_calculate_totalpages()
6369 * Sum pages in active regions for movable zone.
6370 * Populate N_MEMORY for calculating usable_nodes.
6372 static unsigned long __init
early_calculate_totalpages(void)
6374 unsigned long totalpages
= 0;
6375 unsigned long start_pfn
, end_pfn
;
6378 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6379 unsigned long pages
= end_pfn
- start_pfn
;
6381 totalpages
+= pages
;
6383 node_set_state(nid
, N_MEMORY
);
6389 * Find the PFN the Movable zone begins in each node. Kernel memory
6390 * is spread evenly between nodes as long as the nodes have enough
6391 * memory. When they don't, some nodes will have more kernelcore than
6394 static void __init
find_zone_movable_pfns_for_nodes(void)
6397 unsigned long usable_startpfn
;
6398 unsigned long kernelcore_node
, kernelcore_remaining
;
6399 /* save the state before borrow the nodemask */
6400 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6401 unsigned long totalpages
= early_calculate_totalpages();
6402 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6403 struct memblock_region
*r
;
6405 /* Need to find movable_zone earlier when movable_node is specified. */
6406 find_usable_zone_for_movable();
6409 * If movable_node is specified, ignore kernelcore and movablecore
6412 if (movable_node_is_enabled()) {
6413 for_each_memblock(memory
, r
) {
6414 if (!memblock_is_hotpluggable(r
))
6419 usable_startpfn
= PFN_DOWN(r
->base
);
6420 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6421 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6429 * If kernelcore=mirror is specified, ignore movablecore option
6431 if (mirrored_kernelcore
) {
6432 bool mem_below_4gb_not_mirrored
= false;
6434 for_each_memblock(memory
, r
) {
6435 if (memblock_is_mirror(r
))
6440 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6442 if (usable_startpfn
< 0x100000) {
6443 mem_below_4gb_not_mirrored
= true;
6447 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6448 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6452 if (mem_below_4gb_not_mirrored
)
6453 pr_warn("This configuration results in unmirrored kernel memory.");
6459 * If movablecore=nn[KMG] was specified, calculate what size of
6460 * kernelcore that corresponds so that memory usable for
6461 * any allocation type is evenly spread. If both kernelcore
6462 * and movablecore are specified, then the value of kernelcore
6463 * will be used for required_kernelcore if it's greater than
6464 * what movablecore would have allowed.
6466 if (required_movablecore
) {
6467 unsigned long corepages
;
6470 * Round-up so that ZONE_MOVABLE is at least as large as what
6471 * was requested by the user
6473 required_movablecore
=
6474 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6475 required_movablecore
= min(totalpages
, required_movablecore
);
6476 corepages
= totalpages
- required_movablecore
;
6478 required_kernelcore
= max(required_kernelcore
, corepages
);
6482 * If kernelcore was not specified or kernelcore size is larger
6483 * than totalpages, there is no ZONE_MOVABLE.
6485 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6488 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6489 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6492 /* Spread kernelcore memory as evenly as possible throughout nodes */
6493 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6494 for_each_node_state(nid
, N_MEMORY
) {
6495 unsigned long start_pfn
, end_pfn
;
6498 * Recalculate kernelcore_node if the division per node
6499 * now exceeds what is necessary to satisfy the requested
6500 * amount of memory for the kernel
6502 if (required_kernelcore
< kernelcore_node
)
6503 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6506 * As the map is walked, we track how much memory is usable
6507 * by the kernel using kernelcore_remaining. When it is
6508 * 0, the rest of the node is usable by ZONE_MOVABLE
6510 kernelcore_remaining
= kernelcore_node
;
6512 /* Go through each range of PFNs within this node */
6513 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6514 unsigned long size_pages
;
6516 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6517 if (start_pfn
>= end_pfn
)
6520 /* Account for what is only usable for kernelcore */
6521 if (start_pfn
< usable_startpfn
) {
6522 unsigned long kernel_pages
;
6523 kernel_pages
= min(end_pfn
, usable_startpfn
)
6526 kernelcore_remaining
-= min(kernel_pages
,
6527 kernelcore_remaining
);
6528 required_kernelcore
-= min(kernel_pages
,
6529 required_kernelcore
);
6531 /* Continue if range is now fully accounted */
6532 if (end_pfn
<= usable_startpfn
) {
6535 * Push zone_movable_pfn to the end so
6536 * that if we have to rebalance
6537 * kernelcore across nodes, we will
6538 * not double account here
6540 zone_movable_pfn
[nid
] = end_pfn
;
6543 start_pfn
= usable_startpfn
;
6547 * The usable PFN range for ZONE_MOVABLE is from
6548 * start_pfn->end_pfn. Calculate size_pages as the
6549 * number of pages used as kernelcore
6551 size_pages
= end_pfn
- start_pfn
;
6552 if (size_pages
> kernelcore_remaining
)
6553 size_pages
= kernelcore_remaining
;
6554 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6557 * Some kernelcore has been met, update counts and
6558 * break if the kernelcore for this node has been
6561 required_kernelcore
-= min(required_kernelcore
,
6563 kernelcore_remaining
-= size_pages
;
6564 if (!kernelcore_remaining
)
6570 * If there is still required_kernelcore, we do another pass with one
6571 * less node in the count. This will push zone_movable_pfn[nid] further
6572 * along on the nodes that still have memory until kernelcore is
6576 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6580 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6581 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6582 zone_movable_pfn
[nid
] =
6583 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6586 /* restore the node_state */
6587 node_states
[N_MEMORY
] = saved_node_state
;
6590 /* Any regular or high memory on that node ? */
6591 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6593 enum zone_type zone_type
;
6595 if (N_MEMORY
== N_NORMAL_MEMORY
)
6598 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6599 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6600 if (populated_zone(zone
)) {
6601 node_set_state(nid
, N_HIGH_MEMORY
);
6602 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6603 zone_type
<= ZONE_NORMAL
)
6604 node_set_state(nid
, N_NORMAL_MEMORY
);
6611 * free_area_init_nodes - Initialise all pg_data_t and zone data
6612 * @max_zone_pfn: an array of max PFNs for each zone
6614 * This will call free_area_init_node() for each active node in the system.
6615 * Using the page ranges provided by memblock_set_node(), the size of each
6616 * zone in each node and their holes is calculated. If the maximum PFN
6617 * between two adjacent zones match, it is assumed that the zone is empty.
6618 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6619 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6620 * starts where the previous one ended. For example, ZONE_DMA32 starts
6621 * at arch_max_dma_pfn.
6623 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6625 unsigned long start_pfn
, end_pfn
;
6628 /* Record where the zone boundaries are */
6629 memset(arch_zone_lowest_possible_pfn
, 0,
6630 sizeof(arch_zone_lowest_possible_pfn
));
6631 memset(arch_zone_highest_possible_pfn
, 0,
6632 sizeof(arch_zone_highest_possible_pfn
));
6634 start_pfn
= find_min_pfn_with_active_regions();
6636 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6637 if (i
== ZONE_MOVABLE
)
6640 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6641 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6642 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6644 start_pfn
= end_pfn
;
6647 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6648 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6649 find_zone_movable_pfns_for_nodes();
6651 /* Print out the zone ranges */
6652 pr_info("Zone ranges:\n");
6653 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6654 if (i
== ZONE_MOVABLE
)
6656 pr_info(" %-8s ", zone_names
[i
]);
6657 if (arch_zone_lowest_possible_pfn
[i
] ==
6658 arch_zone_highest_possible_pfn
[i
])
6661 pr_cont("[mem %#018Lx-%#018Lx]\n",
6662 (u64
)arch_zone_lowest_possible_pfn
[i
]
6664 ((u64
)arch_zone_highest_possible_pfn
[i
]
6665 << PAGE_SHIFT
) - 1);
6668 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6669 pr_info("Movable zone start for each node\n");
6670 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6671 if (zone_movable_pfn
[i
])
6672 pr_info(" Node %d: %#018Lx\n", i
,
6673 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6676 /* Print out the early node map */
6677 pr_info("Early memory node ranges\n");
6678 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6679 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6680 (u64
)start_pfn
<< PAGE_SHIFT
,
6681 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6683 /* Initialise every node */
6684 mminit_verify_pageflags_layout();
6685 setup_nr_node_ids();
6686 for_each_online_node(nid
) {
6687 pg_data_t
*pgdat
= NODE_DATA(nid
);
6688 free_area_init_node(nid
, NULL
,
6689 find_min_pfn_for_node(nid
), NULL
);
6691 /* Any memory on that node */
6692 if (pgdat
->node_present_pages
)
6693 node_set_state(nid
, N_MEMORY
);
6694 check_for_memory(pgdat
, nid
);
6696 zero_resv_unavail();
6699 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6701 unsigned long long coremem
;
6705 coremem
= memparse(p
, &p
);
6706 *core
= coremem
>> PAGE_SHIFT
;
6708 /* Paranoid check that UL is enough for the coremem value */
6709 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6715 * kernelcore=size sets the amount of memory for use for allocations that
6716 * cannot be reclaimed or migrated.
6718 static int __init
cmdline_parse_kernelcore(char *p
)
6720 /* parse kernelcore=mirror */
6721 if (parse_option_str(p
, "mirror")) {
6722 mirrored_kernelcore
= true;
6726 return cmdline_parse_core(p
, &required_kernelcore
);
6730 * movablecore=size sets the amount of memory for use for allocations that
6731 * can be reclaimed or migrated.
6733 static int __init
cmdline_parse_movablecore(char *p
)
6735 return cmdline_parse_core(p
, &required_movablecore
);
6738 early_param("kernelcore", cmdline_parse_kernelcore
);
6739 early_param("movablecore", cmdline_parse_movablecore
);
6741 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6743 void adjust_managed_page_count(struct page
*page
, long count
)
6745 spin_lock(&managed_page_count_lock
);
6746 page_zone(page
)->managed_pages
+= count
;
6747 totalram_pages
+= count
;
6748 #ifdef CONFIG_HIGHMEM
6749 if (PageHighMem(page
))
6750 totalhigh_pages
+= count
;
6752 spin_unlock(&managed_page_count_lock
);
6754 EXPORT_SYMBOL(adjust_managed_page_count
);
6756 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6759 unsigned long pages
= 0;
6761 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6762 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6763 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6764 if ((unsigned int)poison
<= 0xFF)
6765 memset(pos
, poison
, PAGE_SIZE
);
6766 free_reserved_page(virt_to_page(pos
));
6770 pr_info("Freeing %s memory: %ldK\n",
6771 s
, pages
<< (PAGE_SHIFT
- 10));
6775 EXPORT_SYMBOL(free_reserved_area
);
6777 #ifdef CONFIG_HIGHMEM
6778 void free_highmem_page(struct page
*page
)
6780 __free_reserved_page(page
);
6782 page_zone(page
)->managed_pages
++;
6788 void __init
mem_init_print_info(const char *str
)
6790 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6791 unsigned long init_code_size
, init_data_size
;
6793 physpages
= get_num_physpages();
6794 codesize
= _etext
- _stext
;
6795 datasize
= _edata
- _sdata
;
6796 rosize
= __end_rodata
- __start_rodata
;
6797 bss_size
= __bss_stop
- __bss_start
;
6798 init_data_size
= __init_end
- __init_begin
;
6799 init_code_size
= _einittext
- _sinittext
;
6802 * Detect special cases and adjust section sizes accordingly:
6803 * 1) .init.* may be embedded into .data sections
6804 * 2) .init.text.* may be out of [__init_begin, __init_end],
6805 * please refer to arch/tile/kernel/vmlinux.lds.S.
6806 * 3) .rodata.* may be embedded into .text or .data sections.
6808 #define adj_init_size(start, end, size, pos, adj) \
6810 if (start <= pos && pos < end && size > adj) \
6814 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6815 _sinittext
, init_code_size
);
6816 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6817 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6818 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6819 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6821 #undef adj_init_size
6823 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6824 #ifdef CONFIG_HIGHMEM
6828 nr_free_pages() << (PAGE_SHIFT
- 10),
6829 physpages
<< (PAGE_SHIFT
- 10),
6830 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6831 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6832 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6833 totalcma_pages
<< (PAGE_SHIFT
- 10),
6834 #ifdef CONFIG_HIGHMEM
6835 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6837 str
? ", " : "", str
? str
: "");
6841 * set_dma_reserve - set the specified number of pages reserved in the first zone
6842 * @new_dma_reserve: The number of pages to mark reserved
6844 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6845 * In the DMA zone, a significant percentage may be consumed by kernel image
6846 * and other unfreeable allocations which can skew the watermarks badly. This
6847 * function may optionally be used to account for unfreeable pages in the
6848 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6849 * smaller per-cpu batchsize.
6851 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6853 dma_reserve
= new_dma_reserve
;
6856 void __init
free_area_init(unsigned long *zones_size
)
6858 free_area_init_node(0, zones_size
,
6859 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6860 zero_resv_unavail();
6863 static int page_alloc_cpu_dead(unsigned int cpu
)
6866 lru_add_drain_cpu(cpu
);
6870 * Spill the event counters of the dead processor
6871 * into the current processors event counters.
6872 * This artificially elevates the count of the current
6875 vm_events_fold_cpu(cpu
);
6878 * Zero the differential counters of the dead processor
6879 * so that the vm statistics are consistent.
6881 * This is only okay since the processor is dead and cannot
6882 * race with what we are doing.
6884 cpu_vm_stats_fold(cpu
);
6888 void __init
page_alloc_init(void)
6892 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
6893 "mm/page_alloc:dead", NULL
,
6894 page_alloc_cpu_dead
);
6899 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6900 * or min_free_kbytes changes.
6902 static void calculate_totalreserve_pages(void)
6904 struct pglist_data
*pgdat
;
6905 unsigned long reserve_pages
= 0;
6906 enum zone_type i
, j
;
6908 for_each_online_pgdat(pgdat
) {
6910 pgdat
->totalreserve_pages
= 0;
6912 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6913 struct zone
*zone
= pgdat
->node_zones
+ i
;
6916 /* Find valid and maximum lowmem_reserve in the zone */
6917 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6918 if (zone
->lowmem_reserve
[j
] > max
)
6919 max
= zone
->lowmem_reserve
[j
];
6922 /* we treat the high watermark as reserved pages. */
6923 max
+= high_wmark_pages(zone
);
6925 if (max
> zone
->managed_pages
)
6926 max
= zone
->managed_pages
;
6928 pgdat
->totalreserve_pages
+= max
;
6930 reserve_pages
+= max
;
6933 totalreserve_pages
= reserve_pages
;
6937 * setup_per_zone_lowmem_reserve - called whenever
6938 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6939 * has a correct pages reserved value, so an adequate number of
6940 * pages are left in the zone after a successful __alloc_pages().
6942 static void setup_per_zone_lowmem_reserve(void)
6944 struct pglist_data
*pgdat
;
6945 enum zone_type j
, idx
;
6947 for_each_online_pgdat(pgdat
) {
6948 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6949 struct zone
*zone
= pgdat
->node_zones
+ j
;
6950 unsigned long managed_pages
= zone
->managed_pages
;
6952 zone
->lowmem_reserve
[j
] = 0;
6956 struct zone
*lower_zone
;
6960 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6961 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6963 lower_zone
= pgdat
->node_zones
+ idx
;
6964 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6965 sysctl_lowmem_reserve_ratio
[idx
];
6966 managed_pages
+= lower_zone
->managed_pages
;
6971 /* update totalreserve_pages */
6972 calculate_totalreserve_pages();
6975 static void __setup_per_zone_wmarks(void)
6977 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6978 unsigned long lowmem_pages
= 0;
6980 unsigned long flags
;
6982 /* Calculate total number of !ZONE_HIGHMEM pages */
6983 for_each_zone(zone
) {
6984 if (!is_highmem(zone
))
6985 lowmem_pages
+= zone
->managed_pages
;
6988 for_each_zone(zone
) {
6991 spin_lock_irqsave(&zone
->lock
, flags
);
6992 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6993 do_div(tmp
, lowmem_pages
);
6994 if (is_highmem(zone
)) {
6996 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6997 * need highmem pages, so cap pages_min to a small
7000 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7001 * deltas control asynch page reclaim, and so should
7002 * not be capped for highmem.
7004 unsigned long min_pages
;
7006 min_pages
= zone
->managed_pages
/ 1024;
7007 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7008 zone
->watermark
[WMARK_MIN
] = min_pages
;
7011 * If it's a lowmem zone, reserve a number of pages
7012 * proportionate to the zone's size.
7014 zone
->watermark
[WMARK_MIN
] = tmp
;
7018 * Set the kswapd watermarks distance according to the
7019 * scale factor in proportion to available memory, but
7020 * ensure a minimum size on small systems.
7022 tmp
= max_t(u64
, tmp
>> 2,
7023 mult_frac(zone
->managed_pages
,
7024 watermark_scale_factor
, 10000));
7026 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7027 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7029 spin_unlock_irqrestore(&zone
->lock
, flags
);
7032 /* update totalreserve_pages */
7033 calculate_totalreserve_pages();
7037 * setup_per_zone_wmarks - called when min_free_kbytes changes
7038 * or when memory is hot-{added|removed}
7040 * Ensures that the watermark[min,low,high] values for each zone are set
7041 * correctly with respect to min_free_kbytes.
7043 void setup_per_zone_wmarks(void)
7045 static DEFINE_SPINLOCK(lock
);
7048 __setup_per_zone_wmarks();
7053 * Initialise min_free_kbytes.
7055 * For small machines we want it small (128k min). For large machines
7056 * we want it large (64MB max). But it is not linear, because network
7057 * bandwidth does not increase linearly with machine size. We use
7059 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7060 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7076 int __meminit
init_per_zone_wmark_min(void)
7078 unsigned long lowmem_kbytes
;
7079 int new_min_free_kbytes
;
7081 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7082 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7084 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7085 min_free_kbytes
= new_min_free_kbytes
;
7086 if (min_free_kbytes
< 128)
7087 min_free_kbytes
= 128;
7088 if (min_free_kbytes
> 65536)
7089 min_free_kbytes
= 65536;
7091 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7092 new_min_free_kbytes
, user_min_free_kbytes
);
7094 setup_per_zone_wmarks();
7095 refresh_zone_stat_thresholds();
7096 setup_per_zone_lowmem_reserve();
7099 setup_min_unmapped_ratio();
7100 setup_min_slab_ratio();
7105 core_initcall(init_per_zone_wmark_min
)
7108 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7109 * that we can call two helper functions whenever min_free_kbytes
7112 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7113 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7117 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7122 user_min_free_kbytes
= min_free_kbytes
;
7123 setup_per_zone_wmarks();
7128 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7129 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7133 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7138 setup_per_zone_wmarks();
7144 static void setup_min_unmapped_ratio(void)
7149 for_each_online_pgdat(pgdat
)
7150 pgdat
->min_unmapped_pages
= 0;
7153 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
7154 sysctl_min_unmapped_ratio
) / 100;
7158 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7159 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7163 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7167 setup_min_unmapped_ratio();
7172 static void setup_min_slab_ratio(void)
7177 for_each_online_pgdat(pgdat
)
7178 pgdat
->min_slab_pages
= 0;
7181 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
7182 sysctl_min_slab_ratio
) / 100;
7185 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7186 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7190 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7194 setup_min_slab_ratio();
7201 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7202 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7203 * whenever sysctl_lowmem_reserve_ratio changes.
7205 * The reserve ratio obviously has absolutely no relation with the
7206 * minimum watermarks. The lowmem reserve ratio can only make sense
7207 * if in function of the boot time zone sizes.
7209 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7210 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7212 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7213 setup_per_zone_lowmem_reserve();
7218 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7219 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7220 * pagelist can have before it gets flushed back to buddy allocator.
7222 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7223 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7226 int old_percpu_pagelist_fraction
;
7229 mutex_lock(&pcp_batch_high_lock
);
7230 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7232 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7233 if (!write
|| ret
< 0)
7236 /* Sanity checking to avoid pcp imbalance */
7237 if (percpu_pagelist_fraction
&&
7238 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7239 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7245 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7248 for_each_populated_zone(zone
) {
7251 for_each_possible_cpu(cpu
)
7252 pageset_set_high_and_batch(zone
,
7253 per_cpu_ptr(zone
->pageset
, cpu
));
7256 mutex_unlock(&pcp_batch_high_lock
);
7261 int hashdist
= HASHDIST_DEFAULT
;
7263 static int __init
set_hashdist(char *str
)
7267 hashdist
= simple_strtoul(str
, &str
, 0);
7270 __setup("hashdist=", set_hashdist
);
7273 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7275 * Returns the number of pages that arch has reserved but
7276 * is not known to alloc_large_system_hash().
7278 static unsigned long __init
arch_reserved_kernel_pages(void)
7285 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7286 * machines. As memory size is increased the scale is also increased but at
7287 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7288 * quadruples the scale is increased by one, which means the size of hash table
7289 * only doubles, instead of quadrupling as well.
7290 * Because 32-bit systems cannot have large physical memory, where this scaling
7291 * makes sense, it is disabled on such platforms.
7293 #if __BITS_PER_LONG > 32
7294 #define ADAPT_SCALE_BASE (64ul << 30)
7295 #define ADAPT_SCALE_SHIFT 2
7296 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7300 * allocate a large system hash table from bootmem
7301 * - it is assumed that the hash table must contain an exact power-of-2
7302 * quantity of entries
7303 * - limit is the number of hash buckets, not the total allocation size
7305 void *__init
alloc_large_system_hash(const char *tablename
,
7306 unsigned long bucketsize
,
7307 unsigned long numentries
,
7310 unsigned int *_hash_shift
,
7311 unsigned int *_hash_mask
,
7312 unsigned long low_limit
,
7313 unsigned long high_limit
)
7315 unsigned long long max
= high_limit
;
7316 unsigned long log2qty
, size
;
7320 /* allow the kernel cmdline to have a say */
7322 /* round applicable memory size up to nearest megabyte */
7323 numentries
= nr_kernel_pages
;
7324 numentries
-= arch_reserved_kernel_pages();
7326 /* It isn't necessary when PAGE_SIZE >= 1MB */
7327 if (PAGE_SHIFT
< 20)
7328 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7330 #if __BITS_PER_LONG > 32
7332 unsigned long adapt
;
7334 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
7335 adapt
<<= ADAPT_SCALE_SHIFT
)
7340 /* limit to 1 bucket per 2^scale bytes of low memory */
7341 if (scale
> PAGE_SHIFT
)
7342 numentries
>>= (scale
- PAGE_SHIFT
);
7344 numentries
<<= (PAGE_SHIFT
- scale
);
7346 /* Make sure we've got at least a 0-order allocation.. */
7347 if (unlikely(flags
& HASH_SMALL
)) {
7348 /* Makes no sense without HASH_EARLY */
7349 WARN_ON(!(flags
& HASH_EARLY
));
7350 if (!(numentries
>> *_hash_shift
)) {
7351 numentries
= 1UL << *_hash_shift
;
7352 BUG_ON(!numentries
);
7354 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7355 numentries
= PAGE_SIZE
/ bucketsize
;
7357 numentries
= roundup_pow_of_two(numentries
);
7359 /* limit allocation size to 1/16 total memory by default */
7361 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7362 do_div(max
, bucketsize
);
7364 max
= min(max
, 0x80000000ULL
);
7366 if (numentries
< low_limit
)
7367 numentries
= low_limit
;
7368 if (numentries
> max
)
7371 log2qty
= ilog2(numentries
);
7373 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
7375 size
= bucketsize
<< log2qty
;
7376 if (flags
& HASH_EARLY
) {
7377 if (flags
& HASH_ZERO
)
7378 table
= memblock_virt_alloc_nopanic(size
, 0);
7380 table
= memblock_virt_alloc_raw(size
, 0);
7381 } else if (hashdist
) {
7382 table
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
7385 * If bucketsize is not a power-of-two, we may free
7386 * some pages at the end of hash table which
7387 * alloc_pages_exact() automatically does
7389 if (get_order(size
) < MAX_ORDER
) {
7390 table
= alloc_pages_exact(size
, gfp_flags
);
7391 kmemleak_alloc(table
, size
, 1, gfp_flags
);
7394 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7397 panic("Failed to allocate %s hash table\n", tablename
);
7399 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7400 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7403 *_hash_shift
= log2qty
;
7405 *_hash_mask
= (1 << log2qty
) - 1;
7411 * This function checks whether pageblock includes unmovable pages or not.
7412 * If @count is not zero, it is okay to include less @count unmovable pages
7414 * PageLRU check without isolation or lru_lock could race so that
7415 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7416 * check without lock_page also may miss some movable non-lru pages at
7417 * race condition. So you can't expect this function should be exact.
7419 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7421 bool skip_hwpoisoned_pages
)
7423 unsigned long pfn
, iter
, found
;
7426 * For avoiding noise data, lru_add_drain_all() should be called
7427 * If ZONE_MOVABLE, the zone never contains unmovable pages
7429 if (zone_idx(zone
) == ZONE_MOVABLE
)
7433 * CMA allocations (alloc_contig_range) really need to mark isolate
7434 * CMA pageblocks even when they are not movable in fact so consider
7435 * them movable here.
7437 if (is_migrate_cma(migratetype
) &&
7438 is_migrate_cma(get_pageblock_migratetype(page
)))
7441 pfn
= page_to_pfn(page
);
7442 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7443 unsigned long check
= pfn
+ iter
;
7445 if (!pfn_valid_within(check
))
7448 page
= pfn_to_page(check
);
7450 if (PageReserved(page
))
7454 * Hugepages are not in LRU lists, but they're movable.
7455 * We need not scan over tail pages bacause we don't
7456 * handle each tail page individually in migration.
7458 if (PageHuge(page
)) {
7459 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7464 * We can't use page_count without pin a page
7465 * because another CPU can free compound page.
7466 * This check already skips compound tails of THP
7467 * because their page->_refcount is zero at all time.
7469 if (!page_ref_count(page
)) {
7470 if (PageBuddy(page
))
7471 iter
+= (1 << page_order(page
)) - 1;
7476 * The HWPoisoned page may be not in buddy system, and
7477 * page_count() is not 0.
7479 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7482 if (__PageMovable(page
))
7488 * If there are RECLAIMABLE pages, we need to check
7489 * it. But now, memory offline itself doesn't call
7490 * shrink_node_slabs() and it still to be fixed.
7493 * If the page is not RAM, page_count()should be 0.
7494 * we don't need more check. This is an _used_ not-movable page.
7496 * The problematic thing here is PG_reserved pages. PG_reserved
7497 * is set to both of a memory hole page and a _used_ kernel
7506 bool is_pageblock_removable_nolock(struct page
*page
)
7512 * We have to be careful here because we are iterating over memory
7513 * sections which are not zone aware so we might end up outside of
7514 * the zone but still within the section.
7515 * We have to take care about the node as well. If the node is offline
7516 * its NODE_DATA will be NULL - see page_zone.
7518 if (!node_online(page_to_nid(page
)))
7521 zone
= page_zone(page
);
7522 pfn
= page_to_pfn(page
);
7523 if (!zone_spans_pfn(zone
, pfn
))
7526 return !has_unmovable_pages(zone
, page
, 0, MIGRATE_MOVABLE
, true);
7529 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7531 static unsigned long pfn_max_align_down(unsigned long pfn
)
7533 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7534 pageblock_nr_pages
) - 1);
7537 static unsigned long pfn_max_align_up(unsigned long pfn
)
7539 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7540 pageblock_nr_pages
));
7543 /* [start, end) must belong to a single zone. */
7544 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7545 unsigned long start
, unsigned long end
)
7547 /* This function is based on compact_zone() from compaction.c. */
7548 unsigned long nr_reclaimed
;
7549 unsigned long pfn
= start
;
7550 unsigned int tries
= 0;
7555 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7556 if (fatal_signal_pending(current
)) {
7561 if (list_empty(&cc
->migratepages
)) {
7562 cc
->nr_migratepages
= 0;
7563 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7569 } else if (++tries
== 5) {
7570 ret
= ret
< 0 ? ret
: -EBUSY
;
7574 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7576 cc
->nr_migratepages
-= nr_reclaimed
;
7578 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7579 NULL
, 0, cc
->mode
, MR_CMA
);
7582 putback_movable_pages(&cc
->migratepages
);
7589 * alloc_contig_range() -- tries to allocate given range of pages
7590 * @start: start PFN to allocate
7591 * @end: one-past-the-last PFN to allocate
7592 * @migratetype: migratetype of the underlaying pageblocks (either
7593 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7594 * in range must have the same migratetype and it must
7595 * be either of the two.
7596 * @gfp_mask: GFP mask to use during compaction
7598 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7599 * aligned, however it's the caller's responsibility to guarantee that
7600 * we are the only thread that changes migrate type of pageblocks the
7603 * The PFN range must belong to a single zone.
7605 * Returns zero on success or negative error code. On success all
7606 * pages which PFN is in [start, end) are allocated for the caller and
7607 * need to be freed with free_contig_range().
7609 int alloc_contig_range(unsigned long start
, unsigned long end
,
7610 unsigned migratetype
, gfp_t gfp_mask
)
7612 unsigned long outer_start
, outer_end
;
7616 struct compact_control cc
= {
7617 .nr_migratepages
= 0,
7619 .zone
= page_zone(pfn_to_page(start
)),
7620 .mode
= MIGRATE_SYNC
,
7621 .ignore_skip_hint
= true,
7622 .no_set_skip_hint
= true,
7623 .gfp_mask
= current_gfp_context(gfp_mask
),
7625 INIT_LIST_HEAD(&cc
.migratepages
);
7628 * What we do here is we mark all pageblocks in range as
7629 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7630 * have different sizes, and due to the way page allocator
7631 * work, we align the range to biggest of the two pages so
7632 * that page allocator won't try to merge buddies from
7633 * different pageblocks and change MIGRATE_ISOLATE to some
7634 * other migration type.
7636 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7637 * migrate the pages from an unaligned range (ie. pages that
7638 * we are interested in). This will put all the pages in
7639 * range back to page allocator as MIGRATE_ISOLATE.
7641 * When this is done, we take the pages in range from page
7642 * allocator removing them from the buddy system. This way
7643 * page allocator will never consider using them.
7645 * This lets us mark the pageblocks back as
7646 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7647 * aligned range but not in the unaligned, original range are
7648 * put back to page allocator so that buddy can use them.
7651 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7652 pfn_max_align_up(end
), migratetype
,
7658 * In case of -EBUSY, we'd like to know which page causes problem.
7659 * So, just fall through. We will check it in test_pages_isolated().
7661 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7662 if (ret
&& ret
!= -EBUSY
)
7666 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7667 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7668 * more, all pages in [start, end) are free in page allocator.
7669 * What we are going to do is to allocate all pages from
7670 * [start, end) (that is remove them from page allocator).
7672 * The only problem is that pages at the beginning and at the
7673 * end of interesting range may be not aligned with pages that
7674 * page allocator holds, ie. they can be part of higher order
7675 * pages. Because of this, we reserve the bigger range and
7676 * once this is done free the pages we are not interested in.
7678 * We don't have to hold zone->lock here because the pages are
7679 * isolated thus they won't get removed from buddy.
7682 lru_add_drain_all();
7683 drain_all_pages(cc
.zone
);
7686 outer_start
= start
;
7687 while (!PageBuddy(pfn_to_page(outer_start
))) {
7688 if (++order
>= MAX_ORDER
) {
7689 outer_start
= start
;
7692 outer_start
&= ~0UL << order
;
7695 if (outer_start
!= start
) {
7696 order
= page_order(pfn_to_page(outer_start
));
7699 * outer_start page could be small order buddy page and
7700 * it doesn't include start page. Adjust outer_start
7701 * in this case to report failed page properly
7702 * on tracepoint in test_pages_isolated()
7704 if (outer_start
+ (1UL << order
) <= start
)
7705 outer_start
= start
;
7708 /* Make sure the range is really isolated. */
7709 if (test_pages_isolated(outer_start
, end
, false)) {
7710 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
7711 __func__
, outer_start
, end
);
7716 /* Grab isolated pages from freelists. */
7717 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7723 /* Free head and tail (if any) */
7724 if (start
!= outer_start
)
7725 free_contig_range(outer_start
, start
- outer_start
);
7726 if (end
!= outer_end
)
7727 free_contig_range(end
, outer_end
- end
);
7730 undo_isolate_page_range(pfn_max_align_down(start
),
7731 pfn_max_align_up(end
), migratetype
);
7735 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7737 unsigned int count
= 0;
7739 for (; nr_pages
--; pfn
++) {
7740 struct page
*page
= pfn_to_page(pfn
);
7742 count
+= page_count(page
) != 1;
7745 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7749 #ifdef CONFIG_MEMORY_HOTPLUG
7751 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7752 * page high values need to be recalulated.
7754 void __meminit
zone_pcp_update(struct zone
*zone
)
7757 mutex_lock(&pcp_batch_high_lock
);
7758 for_each_possible_cpu(cpu
)
7759 pageset_set_high_and_batch(zone
,
7760 per_cpu_ptr(zone
->pageset
, cpu
));
7761 mutex_unlock(&pcp_batch_high_lock
);
7765 void zone_pcp_reset(struct zone
*zone
)
7767 unsigned long flags
;
7769 struct per_cpu_pageset
*pset
;
7771 /* avoid races with drain_pages() */
7772 local_irq_save(flags
);
7773 if (zone
->pageset
!= &boot_pageset
) {
7774 for_each_online_cpu(cpu
) {
7775 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7776 drain_zonestat(zone
, pset
);
7778 free_percpu(zone
->pageset
);
7779 zone
->pageset
= &boot_pageset
;
7781 local_irq_restore(flags
);
7784 #ifdef CONFIG_MEMORY_HOTREMOVE
7786 * All pages in the range must be in a single zone and isolated
7787 * before calling this.
7790 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7794 unsigned int order
, i
;
7796 unsigned long flags
;
7797 /* find the first valid pfn */
7798 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7803 offline_mem_sections(pfn
, end_pfn
);
7804 zone
= page_zone(pfn_to_page(pfn
));
7805 spin_lock_irqsave(&zone
->lock
, flags
);
7807 while (pfn
< end_pfn
) {
7808 if (!pfn_valid(pfn
)) {
7812 page
= pfn_to_page(pfn
);
7814 * The HWPoisoned page may be not in buddy system, and
7815 * page_count() is not 0.
7817 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7819 SetPageReserved(page
);
7823 BUG_ON(page_count(page
));
7824 BUG_ON(!PageBuddy(page
));
7825 order
= page_order(page
);
7826 #ifdef CONFIG_DEBUG_VM
7827 pr_info("remove from free list %lx %d %lx\n",
7828 pfn
, 1 << order
, end_pfn
);
7830 list_del(&page
->lru
);
7831 rmv_page_order(page
);
7832 zone
->free_area
[order
].nr_free
--;
7833 for (i
= 0; i
< (1 << order
); i
++)
7834 SetPageReserved((page
+i
));
7835 pfn
+= (1 << order
);
7837 spin_unlock_irqrestore(&zone
->lock
, flags
);
7841 bool is_free_buddy_page(struct page
*page
)
7843 struct zone
*zone
= page_zone(page
);
7844 unsigned long pfn
= page_to_pfn(page
);
7845 unsigned long flags
;
7848 spin_lock_irqsave(&zone
->lock
, flags
);
7849 for (order
= 0; order
< MAX_ORDER
; order
++) {
7850 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7852 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7855 spin_unlock_irqrestore(&zone
->lock
, flags
);
7857 return order
< MAX_ORDER
;