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>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <trace/events/oom.h>
59 #include <linux/prefetch.h>
60 #include <linux/mm_inline.h>
61 #include <linux/migrate.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/sched/mm.h>
65 #include <linux/page_owner.h>
66 #include <linux/kthread.h>
67 #include <linux/memcontrol.h>
68 #include <linux/ftrace.h>
69 #include <linux/lockdep.h>
70 #include <linux/nmi.h>
72 #include <asm/sections.h>
73 #include <asm/tlbflush.h>
74 #include <asm/div64.h>
77 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
78 static DEFINE_MUTEX(pcp_batch_high_lock
);
79 #define MIN_PERCPU_PAGELIST_FRACTION (8)
81 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
82 DEFINE_PER_CPU(int, numa_node
);
83 EXPORT_PER_CPU_SYMBOL(numa_node
);
86 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
88 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
90 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
91 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
92 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
93 * defined in <linux/topology.h>.
95 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
96 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
97 int _node_numa_mem_
[MAX_NUMNODES
];
100 /* work_structs for global per-cpu drains */
101 DEFINE_MUTEX(pcpu_drain_mutex
);
102 DEFINE_PER_CPU(struct work_struct
, pcpu_drain
);
104 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
105 volatile unsigned long latent_entropy __latent_entropy
;
106 EXPORT_SYMBOL(latent_entropy
);
110 * Array of node states.
112 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
113 [N_POSSIBLE
] = NODE_MASK_ALL
,
114 [N_ONLINE
] = { { [0] = 1UL } },
116 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
117 #ifdef CONFIG_HIGHMEM
118 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
120 [N_MEMORY
] = { { [0] = 1UL } },
121 [N_CPU
] = { { [0] = 1UL } },
124 EXPORT_SYMBOL(node_states
);
126 /* Protect totalram_pages and zone->managed_pages */
127 static DEFINE_SPINLOCK(managed_page_count_lock
);
129 unsigned long totalram_pages __read_mostly
;
130 unsigned long totalreserve_pages __read_mostly
;
131 unsigned long totalcma_pages __read_mostly
;
133 int percpu_pagelist_fraction
;
134 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
137 * A cached value of the page's pageblock's migratetype, used when the page is
138 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
139 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
140 * Also the migratetype set in the page does not necessarily match the pcplist
141 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
142 * other index - this ensures that it will be put on the correct CMA freelist.
144 static inline int get_pcppage_migratetype(struct page
*page
)
149 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
151 page
->index
= migratetype
;
154 #ifdef CONFIG_PM_SLEEP
156 * The following functions are used by the suspend/hibernate code to temporarily
157 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
158 * while devices are suspended. To avoid races with the suspend/hibernate code,
159 * they should always be called with pm_mutex held (gfp_allowed_mask also should
160 * only be modified with pm_mutex held, unless the suspend/hibernate code is
161 * guaranteed not to run in parallel with that modification).
164 static gfp_t saved_gfp_mask
;
166 void pm_restore_gfp_mask(void)
168 WARN_ON(!mutex_is_locked(&pm_mutex
));
169 if (saved_gfp_mask
) {
170 gfp_allowed_mask
= saved_gfp_mask
;
175 void pm_restrict_gfp_mask(void)
177 WARN_ON(!mutex_is_locked(&pm_mutex
));
178 WARN_ON(saved_gfp_mask
);
179 saved_gfp_mask
= gfp_allowed_mask
;
180 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
183 bool pm_suspended_storage(void)
185 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
189 #endif /* CONFIG_PM_SLEEP */
191 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
192 unsigned int pageblock_order __read_mostly
;
195 static void __free_pages_ok(struct page
*page
, unsigned int order
);
198 * results with 256, 32 in the lowmem_reserve sysctl:
199 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
200 * 1G machine -> (16M dma, 784M normal, 224M high)
201 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
202 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
203 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
205 * TBD: should special case ZONE_DMA32 machines here - in those we normally
206 * don't need any ZONE_NORMAL reservation
208 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
209 #ifdef CONFIG_ZONE_DMA
212 #ifdef CONFIG_ZONE_DMA32
215 #ifdef CONFIG_HIGHMEM
221 EXPORT_SYMBOL(totalram_pages
);
223 static char * const zone_names
[MAX_NR_ZONES
] = {
224 #ifdef CONFIG_ZONE_DMA
227 #ifdef CONFIG_ZONE_DMA32
231 #ifdef CONFIG_HIGHMEM
235 #ifdef CONFIG_ZONE_DEVICE
240 char * const migratetype_names
[MIGRATE_TYPES
] = {
248 #ifdef CONFIG_MEMORY_ISOLATION
253 compound_page_dtor
* const compound_page_dtors
[] = {
256 #ifdef CONFIG_HUGETLB_PAGE
259 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
264 int min_free_kbytes
= 1024;
265 int user_min_free_kbytes
= -1;
266 int watermark_scale_factor
= 10;
268 static unsigned long __meminitdata nr_kernel_pages
;
269 static unsigned long __meminitdata nr_all_pages
;
270 static unsigned long __meminitdata dma_reserve
;
272 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
273 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
274 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
275 static unsigned long __initdata required_kernelcore
;
276 static unsigned long __initdata required_movablecore
;
277 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
278 static bool mirrored_kernelcore
;
280 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
282 EXPORT_SYMBOL(movable_zone
);
283 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
286 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
287 int nr_online_nodes __read_mostly
= 1;
288 EXPORT_SYMBOL(nr_node_ids
);
289 EXPORT_SYMBOL(nr_online_nodes
);
292 int page_group_by_mobility_disabled __read_mostly
;
294 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
297 * Determine how many pages need to be initialized during early boot
298 * (non-deferred initialization).
299 * The value of first_deferred_pfn will be set later, once non-deferred pages
300 * are initialized, but for now set it ULONG_MAX.
302 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
304 phys_addr_t start_addr
, end_addr
;
305 unsigned long max_pgcnt
;
306 unsigned long reserved
;
309 * Initialise at least 2G of a node but also take into account that
310 * two large system hashes that can take up 1GB for 0.25TB/node.
312 max_pgcnt
= max(2UL << (30 - PAGE_SHIFT
),
313 (pgdat
->node_spanned_pages
>> 8));
316 * Compensate the all the memblock reservations (e.g. crash kernel)
317 * from the initial estimation to make sure we will initialize enough
320 start_addr
= PFN_PHYS(pgdat
->node_start_pfn
);
321 end_addr
= PFN_PHYS(pgdat
->node_start_pfn
+ max_pgcnt
);
322 reserved
= memblock_reserved_memory_within(start_addr
, end_addr
);
323 max_pgcnt
+= PHYS_PFN(reserved
);
325 pgdat
->static_init_pgcnt
= min(max_pgcnt
, pgdat
->node_spanned_pages
);
326 pgdat
->first_deferred_pfn
= ULONG_MAX
;
329 /* Returns true if the struct page for the pfn is uninitialised */
330 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
332 int nid
= early_pfn_to_nid(pfn
);
334 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
341 * Returns false when the remaining initialisation should be deferred until
342 * later in the boot cycle when it can be parallelised.
344 static inline bool update_defer_init(pg_data_t
*pgdat
,
345 unsigned long pfn
, unsigned long zone_end
,
346 unsigned long *nr_initialised
)
348 /* Always populate low zones for address-constrained allocations */
349 if (zone_end
< pgdat_end_pfn(pgdat
))
351 /* Xen PV domains need page structures early */
355 if ((*nr_initialised
> pgdat
->static_init_pgcnt
) &&
356 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
357 pgdat
->first_deferred_pfn
= pfn
;
364 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
368 static inline bool early_page_uninitialised(unsigned long pfn
)
373 static inline bool update_defer_init(pg_data_t
*pgdat
,
374 unsigned long pfn
, unsigned long zone_end
,
375 unsigned long *nr_initialised
)
381 /* Return a pointer to the bitmap storing bits affecting a block of pages */
382 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
385 #ifdef CONFIG_SPARSEMEM
386 return __pfn_to_section(pfn
)->pageblock_flags
;
388 return page_zone(page
)->pageblock_flags
;
389 #endif /* CONFIG_SPARSEMEM */
392 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
394 #ifdef CONFIG_SPARSEMEM
395 pfn
&= (PAGES_PER_SECTION
-1);
396 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
398 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
399 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
400 #endif /* CONFIG_SPARSEMEM */
404 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
405 * @page: The page within the block of interest
406 * @pfn: The target page frame number
407 * @end_bitidx: The last bit of interest to retrieve
408 * @mask: mask of bits that the caller is interested in
410 * Return: pageblock_bits flags
412 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
414 unsigned long end_bitidx
,
417 unsigned long *bitmap
;
418 unsigned long bitidx
, word_bitidx
;
421 bitmap
= get_pageblock_bitmap(page
, pfn
);
422 bitidx
= pfn_to_bitidx(page
, pfn
);
423 word_bitidx
= bitidx
/ BITS_PER_LONG
;
424 bitidx
&= (BITS_PER_LONG
-1);
426 word
= bitmap
[word_bitidx
];
427 bitidx
+= end_bitidx
;
428 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
431 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
432 unsigned long end_bitidx
,
435 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
438 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
440 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
444 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
445 * @page: The page within the block of interest
446 * @flags: The flags to set
447 * @pfn: The target page frame number
448 * @end_bitidx: The last bit of interest
449 * @mask: mask of bits that the caller is interested in
451 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
453 unsigned long end_bitidx
,
456 unsigned long *bitmap
;
457 unsigned long bitidx
, word_bitidx
;
458 unsigned long old_word
, word
;
460 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
462 bitmap
= get_pageblock_bitmap(page
, pfn
);
463 bitidx
= pfn_to_bitidx(page
, pfn
);
464 word_bitidx
= bitidx
/ BITS_PER_LONG
;
465 bitidx
&= (BITS_PER_LONG
-1);
467 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
469 bitidx
+= end_bitidx
;
470 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
471 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
473 word
= READ_ONCE(bitmap
[word_bitidx
]);
475 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
476 if (word
== old_word
)
482 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
484 if (unlikely(page_group_by_mobility_disabled
&&
485 migratetype
< MIGRATE_PCPTYPES
))
486 migratetype
= MIGRATE_UNMOVABLE
;
488 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
489 PB_migrate
, PB_migrate_end
);
492 #ifdef CONFIG_DEBUG_VM
493 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
497 unsigned long pfn
= page_to_pfn(page
);
498 unsigned long sp
, start_pfn
;
501 seq
= zone_span_seqbegin(zone
);
502 start_pfn
= zone
->zone_start_pfn
;
503 sp
= zone
->spanned_pages
;
504 if (!zone_spans_pfn(zone
, pfn
))
506 } while (zone_span_seqretry(zone
, seq
));
509 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
510 pfn
, zone_to_nid(zone
), zone
->name
,
511 start_pfn
, start_pfn
+ sp
);
516 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
518 if (!pfn_valid_within(page_to_pfn(page
)))
520 if (zone
!= page_zone(page
))
526 * Temporary debugging check for pages not lying within a given zone.
528 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
530 if (page_outside_zone_boundaries(zone
, page
))
532 if (!page_is_consistent(zone
, page
))
538 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
544 static void bad_page(struct page
*page
, const char *reason
,
545 unsigned long bad_flags
)
547 static unsigned long resume
;
548 static unsigned long nr_shown
;
549 static unsigned long nr_unshown
;
552 * Allow a burst of 60 reports, then keep quiet for that minute;
553 * or allow a steady drip of one report per second.
555 if (nr_shown
== 60) {
556 if (time_before(jiffies
, resume
)) {
562 "BUG: Bad page state: %lu messages suppressed\n",
569 resume
= jiffies
+ 60 * HZ
;
571 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
572 current
->comm
, page_to_pfn(page
));
573 __dump_page(page
, reason
);
574 bad_flags
&= page
->flags
;
576 pr_alert("bad because of flags: %#lx(%pGp)\n",
577 bad_flags
, &bad_flags
);
578 dump_page_owner(page
);
583 /* Leave bad fields for debug, except PageBuddy could make trouble */
584 page_mapcount_reset(page
); /* remove PageBuddy */
585 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
589 * Higher-order pages are called "compound pages". They are structured thusly:
591 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
593 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
594 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
596 * The first tail page's ->compound_dtor holds the offset in array of compound
597 * page destructors. See compound_page_dtors.
599 * The first tail page's ->compound_order holds the order of allocation.
600 * This usage means that zero-order pages may not be compound.
603 void free_compound_page(struct page
*page
)
605 __free_pages_ok(page
, compound_order(page
));
608 void prep_compound_page(struct page
*page
, unsigned int order
)
611 int nr_pages
= 1 << order
;
613 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
614 set_compound_order(page
, order
);
616 for (i
= 1; i
< nr_pages
; i
++) {
617 struct page
*p
= page
+ i
;
618 set_page_count(p
, 0);
619 p
->mapping
= TAIL_MAPPING
;
620 set_compound_head(p
, page
);
622 atomic_set(compound_mapcount_ptr(page
), -1);
625 #ifdef CONFIG_DEBUG_PAGEALLOC
626 unsigned int _debug_guardpage_minorder
;
627 bool _debug_pagealloc_enabled __read_mostly
628 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
629 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
630 bool _debug_guardpage_enabled __read_mostly
;
632 static int __init
early_debug_pagealloc(char *buf
)
636 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
638 early_param("debug_pagealloc", early_debug_pagealloc
);
640 static bool need_debug_guardpage(void)
642 /* If we don't use debug_pagealloc, we don't need guard page */
643 if (!debug_pagealloc_enabled())
646 if (!debug_guardpage_minorder())
652 static void init_debug_guardpage(void)
654 if (!debug_pagealloc_enabled())
657 if (!debug_guardpage_minorder())
660 _debug_guardpage_enabled
= true;
663 struct page_ext_operations debug_guardpage_ops
= {
664 .need
= need_debug_guardpage
,
665 .init
= init_debug_guardpage
,
668 static int __init
debug_guardpage_minorder_setup(char *buf
)
672 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
673 pr_err("Bad debug_guardpage_minorder value\n");
676 _debug_guardpage_minorder
= res
;
677 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
680 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
682 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
683 unsigned int order
, int migratetype
)
685 struct page_ext
*page_ext
;
687 if (!debug_guardpage_enabled())
690 if (order
>= debug_guardpage_minorder())
693 page_ext
= lookup_page_ext(page
);
694 if (unlikely(!page_ext
))
697 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
699 INIT_LIST_HEAD(&page
->lru
);
700 set_page_private(page
, order
);
701 /* Guard pages are not available for any usage */
702 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
707 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
708 unsigned int order
, int migratetype
)
710 struct page_ext
*page_ext
;
712 if (!debug_guardpage_enabled())
715 page_ext
= lookup_page_ext(page
);
716 if (unlikely(!page_ext
))
719 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
721 set_page_private(page
, 0);
722 if (!is_migrate_isolate(migratetype
))
723 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
726 struct page_ext_operations debug_guardpage_ops
;
727 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
728 unsigned int order
, int migratetype
) { return false; }
729 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
730 unsigned int order
, int migratetype
) {}
733 static inline void set_page_order(struct page
*page
, unsigned int order
)
735 set_page_private(page
, order
);
736 __SetPageBuddy(page
);
739 static inline void rmv_page_order(struct page
*page
)
741 __ClearPageBuddy(page
);
742 set_page_private(page
, 0);
746 * This function checks whether a page is free && is the buddy
747 * we can do coalesce a page and its buddy if
748 * (a) the buddy is not in a hole (check before calling!) &&
749 * (b) the buddy is in the buddy system &&
750 * (c) a page and its buddy have the same order &&
751 * (d) a page and its buddy are in the same zone.
753 * For recording whether a page is in the buddy system, we set ->_mapcount
754 * PAGE_BUDDY_MAPCOUNT_VALUE.
755 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
756 * serialized by zone->lock.
758 * For recording page's order, we use page_private(page).
760 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
763 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
764 if (page_zone_id(page
) != page_zone_id(buddy
))
767 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
772 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
774 * zone check is done late to avoid uselessly
775 * calculating zone/node ids for pages that could
778 if (page_zone_id(page
) != page_zone_id(buddy
))
781 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
789 * Freeing function for a buddy system allocator.
791 * The concept of a buddy system is to maintain direct-mapped table
792 * (containing bit values) for memory blocks of various "orders".
793 * The bottom level table contains the map for the smallest allocatable
794 * units of memory (here, pages), and each level above it describes
795 * pairs of units from the levels below, hence, "buddies".
796 * At a high level, all that happens here is marking the table entry
797 * at the bottom level available, and propagating the changes upward
798 * as necessary, plus some accounting needed to play nicely with other
799 * parts of the VM system.
800 * At each level, we keep a list of pages, which are heads of continuous
801 * free pages of length of (1 << order) and marked with _mapcount
802 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
804 * So when we are allocating or freeing one, we can derive the state of the
805 * other. That is, if we allocate a small block, and both were
806 * free, the remainder of the region must be split into blocks.
807 * If a block is freed, and its buddy is also free, then this
808 * triggers coalescing into a block of larger size.
813 static inline void __free_one_page(struct page
*page
,
815 struct zone
*zone
, unsigned int order
,
818 unsigned long combined_pfn
;
819 unsigned long uninitialized_var(buddy_pfn
);
821 unsigned int max_order
;
823 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
825 VM_BUG_ON(!zone_is_initialized(zone
));
826 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
828 VM_BUG_ON(migratetype
== -1);
829 if (likely(!is_migrate_isolate(migratetype
)))
830 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
832 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
833 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
836 while (order
< max_order
- 1) {
837 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
838 buddy
= page
+ (buddy_pfn
- pfn
);
840 if (!pfn_valid_within(buddy_pfn
))
842 if (!page_is_buddy(page
, buddy
, order
))
845 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
846 * merge with it and move up one order.
848 if (page_is_guard(buddy
)) {
849 clear_page_guard(zone
, buddy
, order
, migratetype
);
851 list_del(&buddy
->lru
);
852 zone
->free_area
[order
].nr_free
--;
853 rmv_page_order(buddy
);
855 combined_pfn
= buddy_pfn
& pfn
;
856 page
= page
+ (combined_pfn
- pfn
);
860 if (max_order
< MAX_ORDER
) {
861 /* If we are here, it means order is >= pageblock_order.
862 * We want to prevent merge between freepages on isolate
863 * pageblock and normal pageblock. Without this, pageblock
864 * isolation could cause incorrect freepage or CMA accounting.
866 * We don't want to hit this code for the more frequent
869 if (unlikely(has_isolate_pageblock(zone
))) {
872 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
873 buddy
= page
+ (buddy_pfn
- pfn
);
874 buddy_mt
= get_pageblock_migratetype(buddy
);
876 if (migratetype
!= buddy_mt
877 && (is_migrate_isolate(migratetype
) ||
878 is_migrate_isolate(buddy_mt
)))
882 goto continue_merging
;
886 set_page_order(page
, order
);
889 * If this is not the largest possible page, check if the buddy
890 * of the next-highest order is free. If it is, it's possible
891 * that pages are being freed that will coalesce soon. In case,
892 * that is happening, add the free page to the tail of the list
893 * so it's less likely to be used soon and more likely to be merged
894 * as a higher order page
896 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)) {
897 struct page
*higher_page
, *higher_buddy
;
898 combined_pfn
= buddy_pfn
& pfn
;
899 higher_page
= page
+ (combined_pfn
- pfn
);
900 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
901 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
902 if (pfn_valid_within(buddy_pfn
) &&
903 page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
904 list_add_tail(&page
->lru
,
905 &zone
->free_area
[order
].free_list
[migratetype
]);
910 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
912 zone
->free_area
[order
].nr_free
++;
916 * A bad page could be due to a number of fields. Instead of multiple branches,
917 * try and check multiple fields with one check. The caller must do a detailed
918 * check if necessary.
920 static inline bool page_expected_state(struct page
*page
,
921 unsigned long check_flags
)
923 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
926 if (unlikely((unsigned long)page
->mapping
|
927 page_ref_count(page
) |
929 (unsigned long)page
->mem_cgroup
|
931 (page
->flags
& check_flags
)))
937 static void free_pages_check_bad(struct page
*page
)
939 const char *bad_reason
;
940 unsigned long bad_flags
;
945 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
946 bad_reason
= "nonzero mapcount";
947 if (unlikely(page
->mapping
!= NULL
))
948 bad_reason
= "non-NULL mapping";
949 if (unlikely(page_ref_count(page
) != 0))
950 bad_reason
= "nonzero _refcount";
951 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
952 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
953 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
956 if (unlikely(page
->mem_cgroup
))
957 bad_reason
= "page still charged to cgroup";
959 bad_page(page
, bad_reason
, bad_flags
);
962 static inline int free_pages_check(struct page
*page
)
964 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
967 /* Something has gone sideways, find it */
968 free_pages_check_bad(page
);
972 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
977 * We rely page->lru.next never has bit 0 set, unless the page
978 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
980 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
982 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
986 switch (page
- head_page
) {
988 /* the first tail page: ->mapping is compound_mapcount() */
989 if (unlikely(compound_mapcount(page
))) {
990 bad_page(page
, "nonzero compound_mapcount", 0);
996 * the second tail page: ->mapping is
997 * page_deferred_list().next -- ignore value.
1001 if (page
->mapping
!= TAIL_MAPPING
) {
1002 bad_page(page
, "corrupted mapping in tail page", 0);
1007 if (unlikely(!PageTail(page
))) {
1008 bad_page(page
, "PageTail not set", 0);
1011 if (unlikely(compound_head(page
) != head_page
)) {
1012 bad_page(page
, "compound_head not consistent", 0);
1017 page
->mapping
= NULL
;
1018 clear_compound_head(page
);
1022 static __always_inline
bool free_pages_prepare(struct page
*page
,
1023 unsigned int order
, bool check_free
)
1027 VM_BUG_ON_PAGE(PageTail(page
), page
);
1029 trace_mm_page_free(page
, order
);
1032 * Check tail pages before head page information is cleared to
1033 * avoid checking PageCompound for order-0 pages.
1035 if (unlikely(order
)) {
1036 bool compound
= PageCompound(page
);
1039 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1042 ClearPageDoubleMap(page
);
1043 for (i
= 1; i
< (1 << order
); i
++) {
1045 bad
+= free_tail_pages_check(page
, page
+ i
);
1046 if (unlikely(free_pages_check(page
+ i
))) {
1050 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1053 if (PageMappingFlags(page
))
1054 page
->mapping
= NULL
;
1055 if (memcg_kmem_enabled() && PageKmemcg(page
))
1056 memcg_kmem_uncharge(page
, order
);
1058 bad
+= free_pages_check(page
);
1062 page_cpupid_reset_last(page
);
1063 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1064 reset_page_owner(page
, order
);
1066 if (!PageHighMem(page
)) {
1067 debug_check_no_locks_freed(page_address(page
),
1068 PAGE_SIZE
<< order
);
1069 debug_check_no_obj_freed(page_address(page
),
1070 PAGE_SIZE
<< order
);
1072 arch_free_page(page
, order
);
1073 kernel_poison_pages(page
, 1 << order
, 0);
1074 kernel_map_pages(page
, 1 << order
, 0);
1075 kasan_free_pages(page
, order
);
1080 #ifdef CONFIG_DEBUG_VM
1081 static inline bool free_pcp_prepare(struct page
*page
)
1083 return free_pages_prepare(page
, 0, true);
1086 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1091 static bool free_pcp_prepare(struct page
*page
)
1093 return free_pages_prepare(page
, 0, false);
1096 static bool bulkfree_pcp_prepare(struct page
*page
)
1098 return free_pages_check(page
);
1100 #endif /* CONFIG_DEBUG_VM */
1103 * Frees a number of pages from the PCP lists
1104 * Assumes all pages on list are in same zone, and of same order.
1105 * count is the number of pages to free.
1107 * If the zone was previously in an "all pages pinned" state then look to
1108 * see if this freeing clears that state.
1110 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1111 * pinned" detection logic.
1113 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1114 struct per_cpu_pages
*pcp
)
1116 int migratetype
= 0;
1118 bool isolated_pageblocks
;
1120 spin_lock(&zone
->lock
);
1121 isolated_pageblocks
= has_isolate_pageblock(zone
);
1125 struct list_head
*list
;
1128 * Remove pages from lists in a round-robin fashion. A
1129 * batch_free count is maintained that is incremented when an
1130 * empty list is encountered. This is so more pages are freed
1131 * off fuller lists instead of spinning excessively around empty
1136 if (++migratetype
== MIGRATE_PCPTYPES
)
1138 list
= &pcp
->lists
[migratetype
];
1139 } while (list_empty(list
));
1141 /* This is the only non-empty list. Free them all. */
1142 if (batch_free
== MIGRATE_PCPTYPES
)
1146 int mt
; /* migratetype of the to-be-freed page */
1148 page
= list_last_entry(list
, struct page
, lru
);
1149 /* must delete as __free_one_page list manipulates */
1150 list_del(&page
->lru
);
1152 mt
= get_pcppage_migratetype(page
);
1153 /* MIGRATE_ISOLATE page should not go to pcplists */
1154 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1155 /* Pageblock could have been isolated meanwhile */
1156 if (unlikely(isolated_pageblocks
))
1157 mt
= get_pageblock_migratetype(page
);
1159 if (bulkfree_pcp_prepare(page
))
1162 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1163 trace_mm_page_pcpu_drain(page
, 0, mt
);
1164 } while (--count
&& --batch_free
&& !list_empty(list
));
1166 spin_unlock(&zone
->lock
);
1169 static void free_one_page(struct zone
*zone
,
1170 struct page
*page
, unsigned long pfn
,
1174 spin_lock(&zone
->lock
);
1175 if (unlikely(has_isolate_pageblock(zone
) ||
1176 is_migrate_isolate(migratetype
))) {
1177 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1179 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1180 spin_unlock(&zone
->lock
);
1183 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1184 unsigned long zone
, int nid
, bool zero
)
1187 mm_zero_struct_page(page
);
1188 set_page_links(page
, zone
, nid
, pfn
);
1189 init_page_count(page
);
1190 page_mapcount_reset(page
);
1191 page_cpupid_reset_last(page
);
1193 INIT_LIST_HEAD(&page
->lru
);
1194 #ifdef WANT_PAGE_VIRTUAL
1195 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1196 if (!is_highmem_idx(zone
))
1197 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1201 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
1204 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
, zero
);
1207 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1208 static void __meminit
init_reserved_page(unsigned long pfn
)
1213 if (!early_page_uninitialised(pfn
))
1216 nid
= early_pfn_to_nid(pfn
);
1217 pgdat
= NODE_DATA(nid
);
1219 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1220 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1222 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1225 __init_single_pfn(pfn
, zid
, nid
, true);
1228 static inline void init_reserved_page(unsigned long pfn
)
1231 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1234 * Initialised pages do not have PageReserved set. This function is
1235 * called for each range allocated by the bootmem allocator and
1236 * marks the pages PageReserved. The remaining valid pages are later
1237 * sent to the buddy page allocator.
1239 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1241 unsigned long start_pfn
= PFN_DOWN(start
);
1242 unsigned long end_pfn
= PFN_UP(end
);
1244 for (; start_pfn
< end_pfn
; start_pfn
++) {
1245 if (pfn_valid(start_pfn
)) {
1246 struct page
*page
= pfn_to_page(start_pfn
);
1248 init_reserved_page(start_pfn
);
1250 /* Avoid false-positive PageTail() */
1251 INIT_LIST_HEAD(&page
->lru
);
1253 SetPageReserved(page
);
1258 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1260 unsigned long flags
;
1262 unsigned long pfn
= page_to_pfn(page
);
1264 if (!free_pages_prepare(page
, order
, true))
1267 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1268 local_irq_save(flags
);
1269 __count_vm_events(PGFREE
, 1 << order
);
1270 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1271 local_irq_restore(flags
);
1274 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1276 unsigned int nr_pages
= 1 << order
;
1277 struct page
*p
= page
;
1281 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1283 __ClearPageReserved(p
);
1284 set_page_count(p
, 0);
1286 __ClearPageReserved(p
);
1287 set_page_count(p
, 0);
1289 page_zone(page
)->managed_pages
+= nr_pages
;
1290 set_page_refcounted(page
);
1291 __free_pages(page
, order
);
1294 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1295 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1297 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1299 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1301 static DEFINE_SPINLOCK(early_pfn_lock
);
1304 spin_lock(&early_pfn_lock
);
1305 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1307 nid
= first_online_node
;
1308 spin_unlock(&early_pfn_lock
);
1314 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1315 static inline bool __meminit __maybe_unused
1316 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1317 struct mminit_pfnnid_cache
*state
)
1321 nid
= __early_pfn_to_nid(pfn
, state
);
1322 if (nid
>= 0 && nid
!= node
)
1327 /* Only safe to use early in boot when initialisation is single-threaded */
1328 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1330 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1335 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1339 static inline bool __meminit __maybe_unused
1340 meminit_pfn_in_nid(unsigned long pfn
, int node
,
1341 struct mminit_pfnnid_cache
*state
)
1348 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1351 if (early_page_uninitialised(pfn
))
1353 return __free_pages_boot_core(page
, order
);
1357 * Check that the whole (or subset of) a pageblock given by the interval of
1358 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1359 * with the migration of free compaction scanner. The scanners then need to
1360 * use only pfn_valid_within() check for arches that allow holes within
1363 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1365 * It's possible on some configurations to have a setup like node0 node1 node0
1366 * i.e. it's possible that all pages within a zones range of pages do not
1367 * belong to a single zone. We assume that a border between node0 and node1
1368 * can occur within a single pageblock, but not a node0 node1 node0
1369 * interleaving within a single pageblock. It is therefore sufficient to check
1370 * the first and last page of a pageblock and avoid checking each individual
1371 * page in a pageblock.
1373 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1374 unsigned long end_pfn
, struct zone
*zone
)
1376 struct page
*start_page
;
1377 struct page
*end_page
;
1379 /* end_pfn is one past the range we are checking */
1382 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1385 start_page
= pfn_to_online_page(start_pfn
);
1389 if (page_zone(start_page
) != zone
)
1392 end_page
= pfn_to_page(end_pfn
);
1394 /* This gives a shorter code than deriving page_zone(end_page) */
1395 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1401 void set_zone_contiguous(struct zone
*zone
)
1403 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1404 unsigned long block_end_pfn
;
1406 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1407 for (; block_start_pfn
< zone_end_pfn(zone
);
1408 block_start_pfn
= block_end_pfn
,
1409 block_end_pfn
+= pageblock_nr_pages
) {
1411 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1413 if (!__pageblock_pfn_to_page(block_start_pfn
,
1414 block_end_pfn
, zone
))
1418 /* We confirm that there is no hole */
1419 zone
->contiguous
= true;
1422 void clear_zone_contiguous(struct zone
*zone
)
1424 zone
->contiguous
= false;
1427 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1428 static void __init
deferred_free_range(unsigned long pfn
,
1429 unsigned long nr_pages
)
1437 page
= pfn_to_page(pfn
);
1439 /* Free a large naturally-aligned chunk if possible */
1440 if (nr_pages
== pageblock_nr_pages
&&
1441 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1442 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1443 __free_pages_boot_core(page
, pageblock_order
);
1447 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1448 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1449 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1450 __free_pages_boot_core(page
, 0);
1454 /* Completion tracking for deferred_init_memmap() threads */
1455 static atomic_t pgdat_init_n_undone __initdata
;
1456 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1458 static inline void __init
pgdat_init_report_one_done(void)
1460 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1461 complete(&pgdat_init_all_done_comp
);
1465 * Returns true if page needs to be initialized or freed to buddy allocator.
1467 * First we check if pfn is valid on architectures where it is possible to have
1468 * holes within pageblock_nr_pages. On systems where it is not possible, this
1469 * function is optimized out.
1471 * Then, we check if a current large page is valid by only checking the validity
1474 * Finally, meminit_pfn_in_nid is checked on systems where pfns can interleave
1475 * within a node: a pfn is between start and end of a node, but does not belong
1476 * to this memory node.
1478 static inline bool __init
1479 deferred_pfn_valid(int nid
, unsigned long pfn
,
1480 struct mminit_pfnnid_cache
*nid_init_state
)
1482 if (!pfn_valid_within(pfn
))
1484 if (!(pfn
& (pageblock_nr_pages
- 1)) && !pfn_valid(pfn
))
1486 if (!meminit_pfn_in_nid(pfn
, nid
, nid_init_state
))
1492 * Free pages to buddy allocator. Try to free aligned pages in
1493 * pageblock_nr_pages sizes.
1495 static void __init
deferred_free_pages(int nid
, int zid
, unsigned long pfn
,
1496 unsigned long end_pfn
)
1498 struct mminit_pfnnid_cache nid_init_state
= { };
1499 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1500 unsigned long nr_free
= 0;
1502 for (; pfn
< end_pfn
; pfn
++) {
1503 if (!deferred_pfn_valid(nid
, pfn
, &nid_init_state
)) {
1504 deferred_free_range(pfn
- nr_free
, nr_free
);
1506 } else if (!(pfn
& nr_pgmask
)) {
1507 deferred_free_range(pfn
- nr_free
, nr_free
);
1514 /* Free the last block of pages to allocator */
1515 deferred_free_range(pfn
- nr_free
, nr_free
);
1519 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1520 * by performing it only once every pageblock_nr_pages.
1521 * Return number of pages initialized.
1523 static unsigned long __init
deferred_init_pages(int nid
, int zid
,
1525 unsigned long end_pfn
)
1527 struct mminit_pfnnid_cache nid_init_state
= { };
1528 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1529 unsigned long nr_pages
= 0;
1530 struct page
*page
= NULL
;
1532 for (; pfn
< end_pfn
; pfn
++) {
1533 if (!deferred_pfn_valid(nid
, pfn
, &nid_init_state
)) {
1536 } else if (!page
|| !(pfn
& nr_pgmask
)) {
1537 page
= pfn_to_page(pfn
);
1542 __init_single_page(page
, pfn
, zid
, nid
, true);
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
);
1586 * Initialize and free pages. We do it in two loops: first we initialize
1587 * struct page, than free to buddy allocator, because while we are
1588 * freeing pages we can access pages that are ahead (computing buddy
1589 * page in __free_one_page()).
1591 for_each_free_mem_range(i
, nid
, MEMBLOCK_NONE
, &spa
, &epa
, NULL
) {
1592 spfn
= max_t(unsigned long, first_init_pfn
, PFN_UP(spa
));
1593 epfn
= min_t(unsigned long, zone_end_pfn(zone
), PFN_DOWN(epa
));
1594 nr_pages
+= deferred_init_pages(nid
, zid
, spfn
, epfn
);
1596 for_each_free_mem_range(i
, nid
, MEMBLOCK_NONE
, &spa
, &epa
, NULL
) {
1597 spfn
= max_t(unsigned long, first_init_pfn
, PFN_UP(spa
));
1598 epfn
= min_t(unsigned long, zone_end_pfn(zone
), PFN_DOWN(epa
));
1599 deferred_free_pages(nid
, zid
, spfn
, epfn
);
1602 /* Sanity check that the next zone really is unpopulated */
1603 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1605 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1606 jiffies_to_msecs(jiffies
- start
));
1608 pgdat_init_report_one_done();
1611 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1613 void __init
page_alloc_init_late(void)
1617 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1620 /* There will be num_node_state(N_MEMORY) threads */
1621 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1622 for_each_node_state(nid
, N_MEMORY
) {
1623 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1626 /* Block until all are initialised */
1627 wait_for_completion(&pgdat_init_all_done_comp
);
1629 /* Reinit limits that are based on free pages after the kernel is up */
1630 files_maxfiles_init();
1632 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
1633 /* Discard memblock private memory */
1637 for_each_populated_zone(zone
)
1638 set_zone_contiguous(zone
);
1642 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1643 void __init
init_cma_reserved_pageblock(struct page
*page
)
1645 unsigned i
= pageblock_nr_pages
;
1646 struct page
*p
= page
;
1649 __ClearPageReserved(p
);
1650 set_page_count(p
, 0);
1653 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1655 if (pageblock_order
>= MAX_ORDER
) {
1656 i
= pageblock_nr_pages
;
1659 set_page_refcounted(p
);
1660 __free_pages(p
, MAX_ORDER
- 1);
1661 p
+= MAX_ORDER_NR_PAGES
;
1662 } while (i
-= MAX_ORDER_NR_PAGES
);
1664 set_page_refcounted(page
);
1665 __free_pages(page
, pageblock_order
);
1668 adjust_managed_page_count(page
, pageblock_nr_pages
);
1673 * The order of subdivision here is critical for the IO subsystem.
1674 * Please do not alter this order without good reasons and regression
1675 * testing. Specifically, as large blocks of memory are subdivided,
1676 * the order in which smaller blocks are delivered depends on the order
1677 * they're subdivided in this function. This is the primary factor
1678 * influencing the order in which pages are delivered to the IO
1679 * subsystem according to empirical testing, and this is also justified
1680 * by considering the behavior of a buddy system containing a single
1681 * large block of memory acted on by a series of small allocations.
1682 * This behavior is a critical factor in sglist merging's success.
1686 static inline void expand(struct zone
*zone
, struct page
*page
,
1687 int low
, int high
, struct free_area
*area
,
1690 unsigned long size
= 1 << high
;
1692 while (high
> low
) {
1696 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1699 * Mark as guard pages (or page), that will allow to
1700 * merge back to allocator when buddy will be freed.
1701 * Corresponding page table entries will not be touched,
1702 * pages will stay not present in virtual address space
1704 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1707 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1709 set_page_order(&page
[size
], high
);
1713 static void check_new_page_bad(struct page
*page
)
1715 const char *bad_reason
= NULL
;
1716 unsigned long bad_flags
= 0;
1718 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1719 bad_reason
= "nonzero mapcount";
1720 if (unlikely(page
->mapping
!= NULL
))
1721 bad_reason
= "non-NULL mapping";
1722 if (unlikely(page_ref_count(page
) != 0))
1723 bad_reason
= "nonzero _count";
1724 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1725 bad_reason
= "HWPoisoned (hardware-corrupted)";
1726 bad_flags
= __PG_HWPOISON
;
1727 /* Don't complain about hwpoisoned pages */
1728 page_mapcount_reset(page
); /* remove PageBuddy */
1731 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1732 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1733 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1736 if (unlikely(page
->mem_cgroup
))
1737 bad_reason
= "page still charged to cgroup";
1739 bad_page(page
, bad_reason
, bad_flags
);
1743 * This page is about to be returned from the page allocator
1745 static inline int check_new_page(struct page
*page
)
1747 if (likely(page_expected_state(page
,
1748 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
1751 check_new_page_bad(page
);
1755 static inline bool free_pages_prezeroed(void)
1757 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1758 page_poisoning_enabled();
1761 #ifdef CONFIG_DEBUG_VM
1762 static bool check_pcp_refill(struct page
*page
)
1767 static bool check_new_pcp(struct page
*page
)
1769 return check_new_page(page
);
1772 static bool check_pcp_refill(struct page
*page
)
1774 return check_new_page(page
);
1776 static bool check_new_pcp(struct page
*page
)
1780 #endif /* CONFIG_DEBUG_VM */
1782 static bool check_new_pages(struct page
*page
, unsigned int order
)
1785 for (i
= 0; i
< (1 << order
); i
++) {
1786 struct page
*p
= page
+ i
;
1788 if (unlikely(check_new_page(p
)))
1795 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
1798 set_page_private(page
, 0);
1799 set_page_refcounted(page
);
1801 arch_alloc_page(page
, order
);
1802 kernel_map_pages(page
, 1 << order
, 1);
1803 kernel_poison_pages(page
, 1 << order
, 1);
1804 kasan_alloc_pages(page
, order
);
1805 set_page_owner(page
, order
, gfp_flags
);
1808 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1809 unsigned int alloc_flags
)
1813 post_alloc_hook(page
, order
, gfp_flags
);
1815 if (!free_pages_prezeroed() && (gfp_flags
& __GFP_ZERO
))
1816 for (i
= 0; i
< (1 << order
); i
++)
1817 clear_highpage(page
+ i
);
1819 if (order
&& (gfp_flags
& __GFP_COMP
))
1820 prep_compound_page(page
, order
);
1823 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1824 * allocate the page. The expectation is that the caller is taking
1825 * steps that will free more memory. The caller should avoid the page
1826 * being used for !PFMEMALLOC purposes.
1828 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1829 set_page_pfmemalloc(page
);
1831 clear_page_pfmemalloc(page
);
1835 * Go through the free lists for the given migratetype and remove
1836 * the smallest available page from the freelists
1838 static __always_inline
1839 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1842 unsigned int current_order
;
1843 struct free_area
*area
;
1846 /* Find a page of the appropriate size in the preferred list */
1847 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1848 area
= &(zone
->free_area
[current_order
]);
1849 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1853 list_del(&page
->lru
);
1854 rmv_page_order(page
);
1856 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1857 set_pcppage_migratetype(page
, migratetype
);
1866 * This array describes the order lists are fallen back to when
1867 * the free lists for the desirable migrate type are depleted
1869 static int fallbacks
[MIGRATE_TYPES
][4] = {
1870 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1871 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1872 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1874 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1876 #ifdef CONFIG_MEMORY_ISOLATION
1877 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1882 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1885 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1888 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1889 unsigned int order
) { return NULL
; }
1893 * Move the free pages in a range to the free lists of the requested type.
1894 * Note that start_page and end_pages are not aligned on a pageblock
1895 * boundary. If alignment is required, use move_freepages_block()
1897 static int move_freepages(struct zone
*zone
,
1898 struct page
*start_page
, struct page
*end_page
,
1899 int migratetype
, int *num_movable
)
1903 int pages_moved
= 0;
1905 #ifndef CONFIG_HOLES_IN_ZONE
1907 * page_zone is not safe to call in this context when
1908 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1909 * anyway as we check zone boundaries in move_freepages_block().
1910 * Remove at a later date when no bug reports exist related to
1911 * grouping pages by mobility
1913 VM_BUG_ON(pfn_valid(page_to_pfn(start_page
)) &&
1914 pfn_valid(page_to_pfn(end_page
)) &&
1915 page_zone(start_page
) != page_zone(end_page
));
1921 for (page
= start_page
; page
<= end_page
;) {
1922 if (!pfn_valid_within(page_to_pfn(page
))) {
1927 /* Make sure we are not inadvertently changing nodes */
1928 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1930 if (!PageBuddy(page
)) {
1932 * We assume that pages that could be isolated for
1933 * migration are movable. But we don't actually try
1934 * isolating, as that would be expensive.
1937 (PageLRU(page
) || __PageMovable(page
)))
1944 order
= page_order(page
);
1945 list_move(&page
->lru
,
1946 &zone
->free_area
[order
].free_list
[migratetype
]);
1948 pages_moved
+= 1 << order
;
1954 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1955 int migratetype
, int *num_movable
)
1957 unsigned long start_pfn
, end_pfn
;
1958 struct page
*start_page
, *end_page
;
1960 start_pfn
= page_to_pfn(page
);
1961 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1962 start_page
= pfn_to_page(start_pfn
);
1963 end_page
= start_page
+ pageblock_nr_pages
- 1;
1964 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1966 /* Do not cross zone boundaries */
1967 if (!zone_spans_pfn(zone
, start_pfn
))
1969 if (!zone_spans_pfn(zone
, end_pfn
))
1972 return move_freepages(zone
, start_page
, end_page
, migratetype
,
1976 static void change_pageblock_range(struct page
*pageblock_page
,
1977 int start_order
, int migratetype
)
1979 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1981 while (nr_pageblocks
--) {
1982 set_pageblock_migratetype(pageblock_page
, migratetype
);
1983 pageblock_page
+= pageblock_nr_pages
;
1988 * When we are falling back to another migratetype during allocation, try to
1989 * steal extra free pages from the same pageblocks to satisfy further
1990 * allocations, instead of polluting multiple pageblocks.
1992 * If we are stealing a relatively large buddy page, it is likely there will
1993 * be more free pages in the pageblock, so try to steal them all. For
1994 * reclaimable and unmovable allocations, we steal regardless of page size,
1995 * as fragmentation caused by those allocations polluting movable pageblocks
1996 * is worse than movable allocations stealing from unmovable and reclaimable
1999 static bool can_steal_fallback(unsigned int order
, int start_mt
)
2002 * Leaving this order check is intended, although there is
2003 * relaxed order check in next check. The reason is that
2004 * we can actually steal whole pageblock if this condition met,
2005 * but, below check doesn't guarantee it and that is just heuristic
2006 * so could be changed anytime.
2008 if (order
>= pageblock_order
)
2011 if (order
>= pageblock_order
/ 2 ||
2012 start_mt
== MIGRATE_RECLAIMABLE
||
2013 start_mt
== MIGRATE_UNMOVABLE
||
2014 page_group_by_mobility_disabled
)
2021 * This function implements actual steal behaviour. If order is large enough,
2022 * we can steal whole pageblock. If not, we first move freepages in this
2023 * pageblock to our migratetype and determine how many already-allocated pages
2024 * are there in the pageblock with a compatible migratetype. If at least half
2025 * of pages are free or compatible, we can change migratetype of the pageblock
2026 * itself, so pages freed in the future will be put on the correct free list.
2028 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2029 int start_type
, bool whole_block
)
2031 unsigned int current_order
= page_order(page
);
2032 struct free_area
*area
;
2033 int free_pages
, movable_pages
, alike_pages
;
2036 old_block_type
= get_pageblock_migratetype(page
);
2039 * This can happen due to races and we want to prevent broken
2040 * highatomic accounting.
2042 if (is_migrate_highatomic(old_block_type
))
2045 /* Take ownership for orders >= pageblock_order */
2046 if (current_order
>= pageblock_order
) {
2047 change_pageblock_range(page
, current_order
, start_type
);
2051 /* We are not allowed to try stealing from the whole block */
2055 free_pages
= move_freepages_block(zone
, page
, start_type
,
2058 * Determine how many pages are compatible with our allocation.
2059 * For movable allocation, it's the number of movable pages which
2060 * we just obtained. For other types it's a bit more tricky.
2062 if (start_type
== MIGRATE_MOVABLE
) {
2063 alike_pages
= movable_pages
;
2066 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2067 * to MOVABLE pageblock, consider all non-movable pages as
2068 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2069 * vice versa, be conservative since we can't distinguish the
2070 * exact migratetype of non-movable pages.
2072 if (old_block_type
== MIGRATE_MOVABLE
)
2073 alike_pages
= pageblock_nr_pages
2074 - (free_pages
+ movable_pages
);
2079 /* moving whole block can fail due to zone boundary conditions */
2084 * If a sufficient number of pages in the block are either free or of
2085 * comparable migratability as our allocation, claim the whole block.
2087 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2088 page_group_by_mobility_disabled
)
2089 set_pageblock_migratetype(page
, start_type
);
2094 area
= &zone
->free_area
[current_order
];
2095 list_move(&page
->lru
, &area
->free_list
[start_type
]);
2099 * Check whether there is a suitable fallback freepage with requested order.
2100 * If only_stealable is true, this function returns fallback_mt only if
2101 * we can steal other freepages all together. This would help to reduce
2102 * fragmentation due to mixed migratetype pages in one pageblock.
2104 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2105 int migratetype
, bool only_stealable
, bool *can_steal
)
2110 if (area
->nr_free
== 0)
2115 fallback_mt
= fallbacks
[migratetype
][i
];
2116 if (fallback_mt
== MIGRATE_TYPES
)
2119 if (list_empty(&area
->free_list
[fallback_mt
]))
2122 if (can_steal_fallback(order
, migratetype
))
2125 if (!only_stealable
)
2136 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2137 * there are no empty page blocks that contain a page with a suitable order
2139 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2140 unsigned int alloc_order
)
2143 unsigned long max_managed
, flags
;
2146 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2147 * Check is race-prone but harmless.
2149 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
2150 if (zone
->nr_reserved_highatomic
>= max_managed
)
2153 spin_lock_irqsave(&zone
->lock
, flags
);
2155 /* Recheck the nr_reserved_highatomic limit under the lock */
2156 if (zone
->nr_reserved_highatomic
>= max_managed
)
2160 mt
= get_pageblock_migratetype(page
);
2161 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2162 && !is_migrate_cma(mt
)) {
2163 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2164 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2165 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2169 spin_unlock_irqrestore(&zone
->lock
, flags
);
2173 * Used when an allocation is about to fail under memory pressure. This
2174 * potentially hurts the reliability of high-order allocations when under
2175 * intense memory pressure but failed atomic allocations should be easier
2176 * to recover from than an OOM.
2178 * If @force is true, try to unreserve a pageblock even though highatomic
2179 * pageblock is exhausted.
2181 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2184 struct zonelist
*zonelist
= ac
->zonelist
;
2185 unsigned long flags
;
2192 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2195 * Preserve at least one pageblock unless memory pressure
2198 if (!force
&& zone
->nr_reserved_highatomic
<=
2202 spin_lock_irqsave(&zone
->lock
, flags
);
2203 for (order
= 0; order
< MAX_ORDER
; order
++) {
2204 struct free_area
*area
= &(zone
->free_area
[order
]);
2206 page
= list_first_entry_or_null(
2207 &area
->free_list
[MIGRATE_HIGHATOMIC
],
2213 * In page freeing path, migratetype change is racy so
2214 * we can counter several free pages in a pageblock
2215 * in this loop althoug we changed the pageblock type
2216 * from highatomic to ac->migratetype. So we should
2217 * adjust the count once.
2219 if (is_migrate_highatomic_page(page
)) {
2221 * It should never happen but changes to
2222 * locking could inadvertently allow a per-cpu
2223 * drain to add pages to MIGRATE_HIGHATOMIC
2224 * while unreserving so be safe and watch for
2227 zone
->nr_reserved_highatomic
-= min(
2229 zone
->nr_reserved_highatomic
);
2233 * Convert to ac->migratetype and avoid the normal
2234 * pageblock stealing heuristics. Minimally, the caller
2235 * is doing the work and needs the pages. More
2236 * importantly, if the block was always converted to
2237 * MIGRATE_UNMOVABLE or another type then the number
2238 * of pageblocks that cannot be completely freed
2241 set_pageblock_migratetype(page
, ac
->migratetype
);
2242 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2245 spin_unlock_irqrestore(&zone
->lock
, flags
);
2249 spin_unlock_irqrestore(&zone
->lock
, flags
);
2256 * Try finding a free buddy page on the fallback list and put it on the free
2257 * list of requested migratetype, possibly along with other pages from the same
2258 * block, depending on fragmentation avoidance heuristics. Returns true if
2259 * fallback was found so that __rmqueue_smallest() can grab it.
2261 * The use of signed ints for order and current_order is a deliberate
2262 * deviation from the rest of this file, to make the for loop
2263 * condition simpler.
2265 static __always_inline
bool
2266 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
2268 struct free_area
*area
;
2275 * Find the largest available free page in the other list. This roughly
2276 * approximates finding the pageblock with the most free pages, which
2277 * would be too costly to do exactly.
2279 for (current_order
= MAX_ORDER
- 1; current_order
>= order
;
2281 area
= &(zone
->free_area
[current_order
]);
2282 fallback_mt
= find_suitable_fallback(area
, current_order
,
2283 start_migratetype
, false, &can_steal
);
2284 if (fallback_mt
== -1)
2288 * We cannot steal all free pages from the pageblock and the
2289 * requested migratetype is movable. In that case it's better to
2290 * steal and split the smallest available page instead of the
2291 * largest available page, because even if the next movable
2292 * allocation falls back into a different pageblock than this
2293 * one, it won't cause permanent fragmentation.
2295 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2296 && current_order
> order
)
2305 for (current_order
= order
; current_order
< MAX_ORDER
;
2307 area
= &(zone
->free_area
[current_order
]);
2308 fallback_mt
= find_suitable_fallback(area
, current_order
,
2309 start_migratetype
, false, &can_steal
);
2310 if (fallback_mt
!= -1)
2315 * This should not happen - we already found a suitable fallback
2316 * when looking for the largest page.
2318 VM_BUG_ON(current_order
== MAX_ORDER
);
2321 page
= list_first_entry(&area
->free_list
[fallback_mt
],
2324 steal_suitable_fallback(zone
, page
, start_migratetype
, can_steal
);
2326 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2327 start_migratetype
, fallback_mt
);
2334 * Do the hard work of removing an element from the buddy allocator.
2335 * Call me with the zone->lock already held.
2337 static __always_inline
struct page
*
2338 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
)
2343 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2344 if (unlikely(!page
)) {
2345 if (migratetype
== MIGRATE_MOVABLE
)
2346 page
= __rmqueue_cma_fallback(zone
, order
);
2348 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
))
2352 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2357 * Obtain a specified number of elements from the buddy allocator, all under
2358 * a single hold of the lock, for efficiency. Add them to the supplied list.
2359 * Returns the number of new pages which were placed at *list.
2361 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2362 unsigned long count
, struct list_head
*list
,
2367 spin_lock(&zone
->lock
);
2368 for (i
= 0; i
< count
; ++i
) {
2369 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
2370 if (unlikely(page
== NULL
))
2373 if (unlikely(check_pcp_refill(page
)))
2377 * Split buddy pages returned by expand() are received here in
2378 * physical page order. The page is added to the tail of
2379 * caller's list. From the callers perspective, the linked list
2380 * is ordered by page number under some conditions. This is
2381 * useful for IO devices that can forward direction from the
2382 * head, thus also in the physical page order. This is useful
2383 * for IO devices that can merge IO requests if the physical
2384 * pages are ordered properly.
2386 list_add_tail(&page
->lru
, list
);
2388 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2389 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2394 * i pages were removed from the buddy list even if some leak due
2395 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2396 * on i. Do not confuse with 'alloced' which is the number of
2397 * pages added to the pcp list.
2399 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2400 spin_unlock(&zone
->lock
);
2406 * Called from the vmstat counter updater to drain pagesets of this
2407 * currently executing processor on remote nodes after they have
2410 * Note that this function must be called with the thread pinned to
2411 * a single processor.
2413 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2415 unsigned long flags
;
2416 int to_drain
, batch
;
2418 local_irq_save(flags
);
2419 batch
= READ_ONCE(pcp
->batch
);
2420 to_drain
= min(pcp
->count
, batch
);
2422 free_pcppages_bulk(zone
, to_drain
, pcp
);
2423 pcp
->count
-= to_drain
;
2425 local_irq_restore(flags
);
2430 * Drain pcplists of the indicated processor and zone.
2432 * The processor must either be the current processor and the
2433 * thread pinned to the current processor or a processor that
2436 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2438 unsigned long flags
;
2439 struct per_cpu_pageset
*pset
;
2440 struct per_cpu_pages
*pcp
;
2442 local_irq_save(flags
);
2443 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2447 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2450 local_irq_restore(flags
);
2454 * Drain pcplists of all zones on the indicated processor.
2456 * The processor must either be the current processor and the
2457 * thread pinned to the current processor or a processor that
2460 static void drain_pages(unsigned int cpu
)
2464 for_each_populated_zone(zone
) {
2465 drain_pages_zone(cpu
, zone
);
2470 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2472 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2473 * the single zone's pages.
2475 void drain_local_pages(struct zone
*zone
)
2477 int cpu
= smp_processor_id();
2480 drain_pages_zone(cpu
, zone
);
2485 static void drain_local_pages_wq(struct work_struct
*work
)
2488 * drain_all_pages doesn't use proper cpu hotplug protection so
2489 * we can race with cpu offline when the WQ can move this from
2490 * a cpu pinned worker to an unbound one. We can operate on a different
2491 * cpu which is allright but we also have to make sure to not move to
2495 drain_local_pages(NULL
);
2500 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2502 * When zone parameter is non-NULL, spill just the single zone's pages.
2504 * Note that this can be extremely slow as the draining happens in a workqueue.
2506 void drain_all_pages(struct zone
*zone
)
2511 * Allocate in the BSS so we wont require allocation in
2512 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2514 static cpumask_t cpus_with_pcps
;
2517 * Make sure nobody triggers this path before mm_percpu_wq is fully
2520 if (WARN_ON_ONCE(!mm_percpu_wq
))
2524 * Do not drain if one is already in progress unless it's specific to
2525 * a zone. Such callers are primarily CMA and memory hotplug and need
2526 * the drain to be complete when the call returns.
2528 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2531 mutex_lock(&pcpu_drain_mutex
);
2535 * We don't care about racing with CPU hotplug event
2536 * as offline notification will cause the notified
2537 * cpu to drain that CPU pcps and on_each_cpu_mask
2538 * disables preemption as part of its processing
2540 for_each_online_cpu(cpu
) {
2541 struct per_cpu_pageset
*pcp
;
2543 bool has_pcps
= false;
2546 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2550 for_each_populated_zone(z
) {
2551 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2552 if (pcp
->pcp
.count
) {
2560 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2562 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2565 for_each_cpu(cpu
, &cpus_with_pcps
) {
2566 struct work_struct
*work
= per_cpu_ptr(&pcpu_drain
, cpu
);
2567 INIT_WORK(work
, drain_local_pages_wq
);
2568 queue_work_on(cpu
, mm_percpu_wq
, work
);
2570 for_each_cpu(cpu
, &cpus_with_pcps
)
2571 flush_work(per_cpu_ptr(&pcpu_drain
, cpu
));
2573 mutex_unlock(&pcpu_drain_mutex
);
2576 #ifdef CONFIG_HIBERNATION
2579 * Touch the watchdog for every WD_PAGE_COUNT pages.
2581 #define WD_PAGE_COUNT (128*1024)
2583 void mark_free_pages(struct zone
*zone
)
2585 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
2586 unsigned long flags
;
2587 unsigned int order
, t
;
2590 if (zone_is_empty(zone
))
2593 spin_lock_irqsave(&zone
->lock
, flags
);
2595 max_zone_pfn
= zone_end_pfn(zone
);
2596 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2597 if (pfn_valid(pfn
)) {
2598 page
= pfn_to_page(pfn
);
2600 if (!--page_count
) {
2601 touch_nmi_watchdog();
2602 page_count
= WD_PAGE_COUNT
;
2605 if (page_zone(page
) != zone
)
2608 if (!swsusp_page_is_forbidden(page
))
2609 swsusp_unset_page_free(page
);
2612 for_each_migratetype_order(order
, t
) {
2613 list_for_each_entry(page
,
2614 &zone
->free_area
[order
].free_list
[t
], lru
) {
2617 pfn
= page_to_pfn(page
);
2618 for (i
= 0; i
< (1UL << order
); i
++) {
2619 if (!--page_count
) {
2620 touch_nmi_watchdog();
2621 page_count
= WD_PAGE_COUNT
;
2623 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2627 spin_unlock_irqrestore(&zone
->lock
, flags
);
2629 #endif /* CONFIG_PM */
2631 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
2635 if (!free_pcp_prepare(page
))
2638 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2639 set_pcppage_migratetype(page
, migratetype
);
2643 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
2645 struct zone
*zone
= page_zone(page
);
2646 struct per_cpu_pages
*pcp
;
2649 migratetype
= get_pcppage_migratetype(page
);
2650 __count_vm_event(PGFREE
);
2653 * We only track unmovable, reclaimable and movable on pcp lists.
2654 * Free ISOLATE pages back to the allocator because they are being
2655 * offlined but treat HIGHATOMIC as movable pages so we can get those
2656 * areas back if necessary. Otherwise, we may have to free
2657 * excessively into the page allocator
2659 if (migratetype
>= MIGRATE_PCPTYPES
) {
2660 if (unlikely(is_migrate_isolate(migratetype
))) {
2661 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2664 migratetype
= MIGRATE_MOVABLE
;
2667 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2668 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2670 if (pcp
->count
>= pcp
->high
) {
2671 unsigned long batch
= READ_ONCE(pcp
->batch
);
2672 free_pcppages_bulk(zone
, batch
, pcp
);
2673 pcp
->count
-= batch
;
2678 * Free a 0-order page
2680 void free_unref_page(struct page
*page
)
2682 unsigned long flags
;
2683 unsigned long pfn
= page_to_pfn(page
);
2685 if (!free_unref_page_prepare(page
, pfn
))
2688 local_irq_save(flags
);
2689 free_unref_page_commit(page
, pfn
);
2690 local_irq_restore(flags
);
2694 * Free a list of 0-order pages
2696 void free_unref_page_list(struct list_head
*list
)
2698 struct page
*page
, *next
;
2699 unsigned long flags
, pfn
;
2700 int batch_count
= 0;
2702 /* Prepare pages for freeing */
2703 list_for_each_entry_safe(page
, next
, list
, lru
) {
2704 pfn
= page_to_pfn(page
);
2705 if (!free_unref_page_prepare(page
, pfn
))
2706 list_del(&page
->lru
);
2707 set_page_private(page
, pfn
);
2710 local_irq_save(flags
);
2711 list_for_each_entry_safe(page
, next
, list
, lru
) {
2712 unsigned long pfn
= page_private(page
);
2714 set_page_private(page
, 0);
2715 trace_mm_page_free_batched(page
);
2716 free_unref_page_commit(page
, pfn
);
2719 * Guard against excessive IRQ disabled times when we get
2720 * a large list of pages to free.
2722 if (++batch_count
== SWAP_CLUSTER_MAX
) {
2723 local_irq_restore(flags
);
2725 local_irq_save(flags
);
2728 local_irq_restore(flags
);
2732 * split_page takes a non-compound higher-order page, and splits it into
2733 * n (1<<order) sub-pages: page[0..n]
2734 * Each sub-page must be freed individually.
2736 * Note: this is probably too low level an operation for use in drivers.
2737 * Please consult with lkml before using this in your driver.
2739 void split_page(struct page
*page
, unsigned int order
)
2743 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2744 VM_BUG_ON_PAGE(!page_count(page
), page
);
2746 for (i
= 1; i
< (1 << order
); i
++)
2747 set_page_refcounted(page
+ i
);
2748 split_page_owner(page
, order
);
2750 EXPORT_SYMBOL_GPL(split_page
);
2752 int __isolate_free_page(struct page
*page
, unsigned int order
)
2754 unsigned long watermark
;
2758 BUG_ON(!PageBuddy(page
));
2760 zone
= page_zone(page
);
2761 mt
= get_pageblock_migratetype(page
);
2763 if (!is_migrate_isolate(mt
)) {
2765 * Obey watermarks as if the page was being allocated. We can
2766 * emulate a high-order watermark check with a raised order-0
2767 * watermark, because we already know our high-order page
2770 watermark
= min_wmark_pages(zone
) + (1UL << order
);
2771 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
2774 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2777 /* Remove page from free list */
2778 list_del(&page
->lru
);
2779 zone
->free_area
[order
].nr_free
--;
2780 rmv_page_order(page
);
2783 * Set the pageblock if the isolated page is at least half of a
2786 if (order
>= pageblock_order
- 1) {
2787 struct page
*endpage
= page
+ (1 << order
) - 1;
2788 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2789 int mt
= get_pageblock_migratetype(page
);
2790 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
2791 && !is_migrate_highatomic(mt
))
2792 set_pageblock_migratetype(page
,
2798 return 1UL << order
;
2802 * Update NUMA hit/miss statistics
2804 * Must be called with interrupts disabled.
2806 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
2809 enum numa_stat_item local_stat
= NUMA_LOCAL
;
2811 /* skip numa counters update if numa stats is disabled */
2812 if (!static_branch_likely(&vm_numa_stat_key
))
2815 if (z
->node
!= numa_node_id())
2816 local_stat
= NUMA_OTHER
;
2818 if (z
->node
== preferred_zone
->node
)
2819 __inc_numa_state(z
, NUMA_HIT
);
2821 __inc_numa_state(z
, NUMA_MISS
);
2822 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
2824 __inc_numa_state(z
, local_stat
);
2828 /* Remove page from the per-cpu list, caller must protect the list */
2829 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
2830 struct per_cpu_pages
*pcp
,
2831 struct list_head
*list
)
2836 if (list_empty(list
)) {
2837 pcp
->count
+= rmqueue_bulk(zone
, 0,
2840 if (unlikely(list_empty(list
)))
2844 page
= list_first_entry(list
, struct page
, lru
);
2845 list_del(&page
->lru
);
2847 } while (check_new_pcp(page
));
2852 /* Lock and remove page from the per-cpu list */
2853 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
2854 struct zone
*zone
, unsigned int order
,
2855 gfp_t gfp_flags
, int migratetype
)
2857 struct per_cpu_pages
*pcp
;
2858 struct list_head
*list
;
2860 unsigned long flags
;
2862 local_irq_save(flags
);
2863 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2864 list
= &pcp
->lists
[migratetype
];
2865 page
= __rmqueue_pcplist(zone
, migratetype
, pcp
, list
);
2867 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2868 zone_statistics(preferred_zone
, zone
);
2870 local_irq_restore(flags
);
2875 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2878 struct page
*rmqueue(struct zone
*preferred_zone
,
2879 struct zone
*zone
, unsigned int order
,
2880 gfp_t gfp_flags
, unsigned int alloc_flags
,
2883 unsigned long flags
;
2886 if (likely(order
== 0)) {
2887 page
= rmqueue_pcplist(preferred_zone
, zone
, order
,
2888 gfp_flags
, migratetype
);
2893 * We most definitely don't want callers attempting to
2894 * allocate greater than order-1 page units with __GFP_NOFAIL.
2896 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2897 spin_lock_irqsave(&zone
->lock
, flags
);
2901 if (alloc_flags
& ALLOC_HARDER
) {
2902 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2904 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2907 page
= __rmqueue(zone
, order
, migratetype
);
2908 } while (page
&& check_new_pages(page
, order
));
2909 spin_unlock(&zone
->lock
);
2912 __mod_zone_freepage_state(zone
, -(1 << order
),
2913 get_pcppage_migratetype(page
));
2915 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
2916 zone_statistics(preferred_zone
, zone
);
2917 local_irq_restore(flags
);
2920 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
2924 local_irq_restore(flags
);
2928 #ifdef CONFIG_FAIL_PAGE_ALLOC
2931 struct fault_attr attr
;
2933 bool ignore_gfp_highmem
;
2934 bool ignore_gfp_reclaim
;
2936 } fail_page_alloc
= {
2937 .attr
= FAULT_ATTR_INITIALIZER
,
2938 .ignore_gfp_reclaim
= true,
2939 .ignore_gfp_highmem
= true,
2943 static int __init
setup_fail_page_alloc(char *str
)
2945 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2947 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2949 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2951 if (order
< fail_page_alloc
.min_order
)
2953 if (gfp_mask
& __GFP_NOFAIL
)
2955 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2957 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2958 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2961 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2964 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2966 static int __init
fail_page_alloc_debugfs(void)
2968 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2971 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2972 &fail_page_alloc
.attr
);
2974 return PTR_ERR(dir
);
2976 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2977 &fail_page_alloc
.ignore_gfp_reclaim
))
2979 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2980 &fail_page_alloc
.ignore_gfp_highmem
))
2982 if (!debugfs_create_u32("min-order", mode
, dir
,
2983 &fail_page_alloc
.min_order
))
2988 debugfs_remove_recursive(dir
);
2993 late_initcall(fail_page_alloc_debugfs
);
2995 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2997 #else /* CONFIG_FAIL_PAGE_ALLOC */
2999 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3004 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3007 * Return true if free base pages are above 'mark'. For high-order checks it
3008 * will return true of the order-0 watermark is reached and there is at least
3009 * one free page of a suitable size. Checking now avoids taking the zone lock
3010 * to check in the allocation paths if no pages are free.
3012 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3013 int classzone_idx
, unsigned int alloc_flags
,
3018 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3020 /* free_pages may go negative - that's OK */
3021 free_pages
-= (1 << order
) - 1;
3023 if (alloc_flags
& ALLOC_HIGH
)
3027 * If the caller does not have rights to ALLOC_HARDER then subtract
3028 * the high-atomic reserves. This will over-estimate the size of the
3029 * atomic reserve but it avoids a search.
3031 if (likely(!alloc_harder
)) {
3032 free_pages
-= z
->nr_reserved_highatomic
;
3035 * OOM victims can try even harder than normal ALLOC_HARDER
3036 * users on the grounds that it's definitely going to be in
3037 * the exit path shortly and free memory. Any allocation it
3038 * makes during the free path will be small and short-lived.
3040 if (alloc_flags
& ALLOC_OOM
)
3048 /* If allocation can't use CMA areas don't use free CMA pages */
3049 if (!(alloc_flags
& ALLOC_CMA
))
3050 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3054 * Check watermarks for an order-0 allocation request. If these
3055 * are not met, then a high-order request also cannot go ahead
3056 * even if a suitable page happened to be free.
3058 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
3061 /* If this is an order-0 request then the watermark is fine */
3065 /* For a high-order request, check at least one suitable page is free */
3066 for (o
= order
; o
< MAX_ORDER
; o
++) {
3067 struct free_area
*area
= &z
->free_area
[o
];
3073 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3074 if (!list_empty(&area
->free_list
[mt
]))
3079 if ((alloc_flags
& ALLOC_CMA
) &&
3080 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
3085 !list_empty(&area
->free_list
[MIGRATE_HIGHATOMIC
]))
3091 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3092 int classzone_idx
, unsigned int alloc_flags
)
3094 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3095 zone_page_state(z
, NR_FREE_PAGES
));
3098 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3099 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
3101 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3105 /* If allocation can't use CMA areas don't use free CMA pages */
3106 if (!(alloc_flags
& ALLOC_CMA
))
3107 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3111 * Fast check for order-0 only. If this fails then the reserves
3112 * need to be calculated. There is a corner case where the check
3113 * passes but only the high-order atomic reserve are free. If
3114 * the caller is !atomic then it'll uselessly search the free
3115 * list. That corner case is then slower but it is harmless.
3117 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
3120 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3124 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3125 unsigned long mark
, int classzone_idx
)
3127 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3129 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3130 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3132 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
3137 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3139 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3142 #else /* CONFIG_NUMA */
3143 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3147 #endif /* CONFIG_NUMA */
3150 * get_page_from_freelist goes through the zonelist trying to allocate
3153 static struct page
*
3154 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3155 const struct alloc_context
*ac
)
3157 struct zoneref
*z
= ac
->preferred_zoneref
;
3159 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3162 * Scan zonelist, looking for a zone with enough free.
3163 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3165 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3170 if (cpusets_enabled() &&
3171 (alloc_flags
& ALLOC_CPUSET
) &&
3172 !__cpuset_zone_allowed(zone
, gfp_mask
))
3175 * When allocating a page cache page for writing, we
3176 * want to get it from a node that is within its dirty
3177 * limit, such that no single node holds more than its
3178 * proportional share of globally allowed dirty pages.
3179 * The dirty limits take into account the node's
3180 * lowmem reserves and high watermark so that kswapd
3181 * should be able to balance it without having to
3182 * write pages from its LRU list.
3184 * XXX: For now, allow allocations to potentially
3185 * exceed the per-node dirty limit in the slowpath
3186 * (spread_dirty_pages unset) before going into reclaim,
3187 * which is important when on a NUMA setup the allowed
3188 * nodes are together not big enough to reach the
3189 * global limit. The proper fix for these situations
3190 * will require awareness of nodes in the
3191 * dirty-throttling and the flusher threads.
3193 if (ac
->spread_dirty_pages
) {
3194 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3197 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3198 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3203 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
3204 if (!zone_watermark_fast(zone
, order
, mark
,
3205 ac_classzone_idx(ac
), alloc_flags
)) {
3208 /* Checked here to keep the fast path fast */
3209 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3210 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3213 if (node_reclaim_mode
== 0 ||
3214 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3217 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3219 case NODE_RECLAIM_NOSCAN
:
3222 case NODE_RECLAIM_FULL
:
3223 /* scanned but unreclaimable */
3226 /* did we reclaim enough */
3227 if (zone_watermark_ok(zone
, order
, mark
,
3228 ac_classzone_idx(ac
), alloc_flags
))
3236 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3237 gfp_mask
, alloc_flags
, ac
->migratetype
);
3239 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3242 * If this is a high-order atomic allocation then check
3243 * if the pageblock should be reserved for the future
3245 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3246 reserve_highatomic_pageblock(page
, zone
, order
);
3256 * Large machines with many possible nodes should not always dump per-node
3257 * meminfo in irq context.
3259 static inline bool should_suppress_show_mem(void)
3264 ret
= in_interrupt();
3269 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3271 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3272 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3274 if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs
))
3278 * This documents exceptions given to allocations in certain
3279 * contexts that are allowed to allocate outside current's set
3282 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3283 if (tsk_is_oom_victim(current
) ||
3284 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3285 filter
&= ~SHOW_MEM_FILTER_NODES
;
3286 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3287 filter
&= ~SHOW_MEM_FILTER_NODES
;
3289 show_mem(filter
, nodemask
);
3292 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3294 struct va_format vaf
;
3296 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3297 DEFAULT_RATELIMIT_BURST
);
3299 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3302 va_start(args
, fmt
);
3305 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl\n",
3306 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
3307 nodemask_pr_args(nodemask
));
3310 cpuset_print_current_mems_allowed();
3313 warn_alloc_show_mem(gfp_mask
, nodemask
);
3316 static inline struct page
*
3317 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3318 unsigned int alloc_flags
,
3319 const struct alloc_context
*ac
)
3323 page
= get_page_from_freelist(gfp_mask
, order
,
3324 alloc_flags
|ALLOC_CPUSET
, ac
);
3326 * fallback to ignore cpuset restriction if our nodes
3330 page
= get_page_from_freelist(gfp_mask
, order
,
3336 static inline struct page
*
3337 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3338 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3340 struct oom_control oc
= {
3341 .zonelist
= ac
->zonelist
,
3342 .nodemask
= ac
->nodemask
,
3344 .gfp_mask
= gfp_mask
,
3349 *did_some_progress
= 0;
3352 * Acquire the oom lock. If that fails, somebody else is
3353 * making progress for us.
3355 if (!mutex_trylock(&oom_lock
)) {
3356 *did_some_progress
= 1;
3357 schedule_timeout_uninterruptible(1);
3362 * Go through the zonelist yet one more time, keep very high watermark
3363 * here, this is only to catch a parallel oom killing, we must fail if
3364 * we're still under heavy pressure. But make sure that this reclaim
3365 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3366 * allocation which will never fail due to oom_lock already held.
3368 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
3369 ~__GFP_DIRECT_RECLAIM
, order
,
3370 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3374 /* Coredumps can quickly deplete all memory reserves */
3375 if (current
->flags
& PF_DUMPCORE
)
3377 /* The OOM killer will not help higher order allocs */
3378 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3381 * We have already exhausted all our reclaim opportunities without any
3382 * success so it is time to admit defeat. We will skip the OOM killer
3383 * because it is very likely that the caller has a more reasonable
3384 * fallback than shooting a random task.
3386 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
3388 /* The OOM killer does not needlessly kill tasks for lowmem */
3389 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3391 if (pm_suspended_storage())
3394 * XXX: GFP_NOFS allocations should rather fail than rely on
3395 * other request to make a forward progress.
3396 * We are in an unfortunate situation where out_of_memory cannot
3397 * do much for this context but let's try it to at least get
3398 * access to memory reserved if the current task is killed (see
3399 * out_of_memory). Once filesystems are ready to handle allocation
3400 * failures more gracefully we should just bail out here.
3403 /* The OOM killer may not free memory on a specific node */
3404 if (gfp_mask
& __GFP_THISNODE
)
3407 /* Exhausted what can be done so it's blame time */
3408 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3409 *did_some_progress
= 1;
3412 * Help non-failing allocations by giving them access to memory
3415 if (gfp_mask
& __GFP_NOFAIL
)
3416 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3417 ALLOC_NO_WATERMARKS
, ac
);
3420 mutex_unlock(&oom_lock
);
3425 * Maximum number of compaction retries wit a progress before OOM
3426 * killer is consider as the only way to move forward.
3428 #define MAX_COMPACT_RETRIES 16
3430 #ifdef CONFIG_COMPACTION
3431 /* Try memory compaction for high-order allocations before reclaim */
3432 static struct page
*
3433 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3434 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3435 enum compact_priority prio
, enum compact_result
*compact_result
)
3438 unsigned int noreclaim_flag
;
3443 noreclaim_flag
= memalloc_noreclaim_save();
3444 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3446 memalloc_noreclaim_restore(noreclaim_flag
);
3448 if (*compact_result
<= COMPACT_INACTIVE
)
3452 * At least in one zone compaction wasn't deferred or skipped, so let's
3453 * count a compaction stall
3455 count_vm_event(COMPACTSTALL
);
3457 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3460 struct zone
*zone
= page_zone(page
);
3462 zone
->compact_blockskip_flush
= false;
3463 compaction_defer_reset(zone
, order
, true);
3464 count_vm_event(COMPACTSUCCESS
);
3469 * It's bad if compaction run occurs and fails. The most likely reason
3470 * is that pages exist, but not enough to satisfy watermarks.
3472 count_vm_event(COMPACTFAIL
);
3480 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3481 enum compact_result compact_result
,
3482 enum compact_priority
*compact_priority
,
3483 int *compaction_retries
)
3485 int max_retries
= MAX_COMPACT_RETRIES
;
3488 int retries
= *compaction_retries
;
3489 enum compact_priority priority
= *compact_priority
;
3494 if (compaction_made_progress(compact_result
))
3495 (*compaction_retries
)++;
3498 * compaction considers all the zone as desperately out of memory
3499 * so it doesn't really make much sense to retry except when the
3500 * failure could be caused by insufficient priority
3502 if (compaction_failed(compact_result
))
3503 goto check_priority
;
3506 * make sure the compaction wasn't deferred or didn't bail out early
3507 * due to locks contention before we declare that we should give up.
3508 * But do not retry if the given zonelist is not suitable for
3511 if (compaction_withdrawn(compact_result
)) {
3512 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3517 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3518 * costly ones because they are de facto nofail and invoke OOM
3519 * killer to move on while costly can fail and users are ready
3520 * to cope with that. 1/4 retries is rather arbitrary but we
3521 * would need much more detailed feedback from compaction to
3522 * make a better decision.
3524 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3526 if (*compaction_retries
<= max_retries
) {
3532 * Make sure there are attempts at the highest priority if we exhausted
3533 * all retries or failed at the lower priorities.
3536 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3537 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3539 if (*compact_priority
> min_priority
) {
3540 (*compact_priority
)--;
3541 *compaction_retries
= 0;
3545 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3549 static inline struct page
*
3550 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3551 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3552 enum compact_priority prio
, enum compact_result
*compact_result
)
3554 *compact_result
= COMPACT_SKIPPED
;
3559 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3560 enum compact_result compact_result
,
3561 enum compact_priority
*compact_priority
,
3562 int *compaction_retries
)
3567 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3571 * There are setups with compaction disabled which would prefer to loop
3572 * inside the allocator rather than hit the oom killer prematurely.
3573 * Let's give them a good hope and keep retrying while the order-0
3574 * watermarks are OK.
3576 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3578 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3579 ac_classzone_idx(ac
), alloc_flags
))
3584 #endif /* CONFIG_COMPACTION */
3586 #ifdef CONFIG_LOCKDEP
3587 struct lockdep_map __fs_reclaim_map
=
3588 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
3590 static bool __need_fs_reclaim(gfp_t gfp_mask
)
3592 gfp_mask
= current_gfp_context(gfp_mask
);
3594 /* no reclaim without waiting on it */
3595 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3598 /* this guy won't enter reclaim */
3599 if (current
->flags
& PF_MEMALLOC
)
3602 /* We're only interested __GFP_FS allocations for now */
3603 if (!(gfp_mask
& __GFP_FS
))
3606 if (gfp_mask
& __GFP_NOLOCKDEP
)
3612 void fs_reclaim_acquire(gfp_t gfp_mask
)
3614 if (__need_fs_reclaim(gfp_mask
))
3615 lock_map_acquire(&__fs_reclaim_map
);
3617 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
3619 void fs_reclaim_release(gfp_t gfp_mask
)
3621 if (__need_fs_reclaim(gfp_mask
))
3622 lock_map_release(&__fs_reclaim_map
);
3624 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
3627 /* Perform direct synchronous page reclaim */
3629 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
3630 const struct alloc_context
*ac
)
3632 struct reclaim_state reclaim_state
;
3634 unsigned int noreclaim_flag
;
3638 /* We now go into synchronous reclaim */
3639 cpuset_memory_pressure_bump();
3640 noreclaim_flag
= memalloc_noreclaim_save();
3641 fs_reclaim_acquire(gfp_mask
);
3642 reclaim_state
.reclaimed_slab
= 0;
3643 current
->reclaim_state
= &reclaim_state
;
3645 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3648 current
->reclaim_state
= NULL
;
3649 fs_reclaim_release(gfp_mask
);
3650 memalloc_noreclaim_restore(noreclaim_flag
);
3657 /* The really slow allocator path where we enter direct reclaim */
3658 static inline struct page
*
3659 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3660 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3661 unsigned long *did_some_progress
)
3663 struct page
*page
= NULL
;
3664 bool drained
= false;
3666 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3667 if (unlikely(!(*did_some_progress
)))
3671 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3674 * If an allocation failed after direct reclaim, it could be because
3675 * pages are pinned on the per-cpu lists or in high alloc reserves.
3676 * Shrink them them and try again
3678 if (!page
&& !drained
) {
3679 unreserve_highatomic_pageblock(ac
, false);
3680 drain_all_pages(NULL
);
3688 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3692 pg_data_t
*last_pgdat
= NULL
;
3694 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3695 ac
->high_zoneidx
, ac
->nodemask
) {
3696 if (last_pgdat
!= zone
->zone_pgdat
)
3697 wakeup_kswapd(zone
, order
, ac
->high_zoneidx
);
3698 last_pgdat
= zone
->zone_pgdat
;
3702 static inline unsigned int
3703 gfp_to_alloc_flags(gfp_t gfp_mask
)
3705 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3707 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3708 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3711 * The caller may dip into page reserves a bit more if the caller
3712 * cannot run direct reclaim, or if the caller has realtime scheduling
3713 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3714 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3716 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3718 if (gfp_mask
& __GFP_ATOMIC
) {
3720 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3721 * if it can't schedule.
3723 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3724 alloc_flags
|= ALLOC_HARDER
;
3726 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3727 * comment for __cpuset_node_allowed().
3729 alloc_flags
&= ~ALLOC_CPUSET
;
3730 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3731 alloc_flags
|= ALLOC_HARDER
;
3734 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3735 alloc_flags
|= ALLOC_CMA
;
3740 static bool oom_reserves_allowed(struct task_struct
*tsk
)
3742 if (!tsk_is_oom_victim(tsk
))
3746 * !MMU doesn't have oom reaper so give access to memory reserves
3747 * only to the thread with TIF_MEMDIE set
3749 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
3756 * Distinguish requests which really need access to full memory
3757 * reserves from oom victims which can live with a portion of it
3759 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
3761 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
3763 if (gfp_mask
& __GFP_MEMALLOC
)
3764 return ALLOC_NO_WATERMARKS
;
3765 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3766 return ALLOC_NO_WATERMARKS
;
3767 if (!in_interrupt()) {
3768 if (current
->flags
& PF_MEMALLOC
)
3769 return ALLOC_NO_WATERMARKS
;
3770 else if (oom_reserves_allowed(current
))
3777 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3779 return !!__gfp_pfmemalloc_flags(gfp_mask
);
3783 * Checks whether it makes sense to retry the reclaim to make a forward progress
3784 * for the given allocation request.
3786 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
3787 * without success, or when we couldn't even meet the watermark if we
3788 * reclaimed all remaining pages on the LRU lists.
3790 * Returns true if a retry is viable or false to enter the oom path.
3793 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
3794 struct alloc_context
*ac
, int alloc_flags
,
3795 bool did_some_progress
, int *no_progress_loops
)
3801 * Costly allocations might have made a progress but this doesn't mean
3802 * their order will become available due to high fragmentation so
3803 * always increment the no progress counter for them
3805 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
3806 *no_progress_loops
= 0;
3808 (*no_progress_loops
)++;
3811 * Make sure we converge to OOM if we cannot make any progress
3812 * several times in the row.
3814 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
3815 /* Before OOM, exhaust highatomic_reserve */
3816 return unreserve_highatomic_pageblock(ac
, true);
3820 * Keep reclaiming pages while there is a chance this will lead
3821 * somewhere. If none of the target zones can satisfy our allocation
3822 * request even if all reclaimable pages are considered then we are
3823 * screwed and have to go OOM.
3825 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3827 unsigned long available
;
3828 unsigned long reclaimable
;
3829 unsigned long min_wmark
= min_wmark_pages(zone
);
3832 available
= reclaimable
= zone_reclaimable_pages(zone
);
3833 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
3836 * Would the allocation succeed if we reclaimed all
3837 * reclaimable pages?
3839 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
3840 ac_classzone_idx(ac
), alloc_flags
, available
);
3841 trace_reclaim_retry_zone(z
, order
, reclaimable
,
3842 available
, min_wmark
, *no_progress_loops
, wmark
);
3845 * If we didn't make any progress and have a lot of
3846 * dirty + writeback pages then we should wait for
3847 * an IO to complete to slow down the reclaim and
3848 * prevent from pre mature OOM
3850 if (!did_some_progress
) {
3851 unsigned long write_pending
;
3853 write_pending
= zone_page_state_snapshot(zone
,
3854 NR_ZONE_WRITE_PENDING
);
3856 if (2 * write_pending
> reclaimable
) {
3857 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
3863 * Memory allocation/reclaim might be called from a WQ
3864 * context and the current implementation of the WQ
3865 * concurrency control doesn't recognize that
3866 * a particular WQ is congested if the worker thread is
3867 * looping without ever sleeping. Therefore we have to
3868 * do a short sleep here rather than calling
3871 if (current
->flags
& PF_WQ_WORKER
)
3872 schedule_timeout_uninterruptible(1);
3884 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
3887 * It's possible that cpuset's mems_allowed and the nodemask from
3888 * mempolicy don't intersect. This should be normally dealt with by
3889 * policy_nodemask(), but it's possible to race with cpuset update in
3890 * such a way the check therein was true, and then it became false
3891 * before we got our cpuset_mems_cookie here.
3892 * This assumes that for all allocations, ac->nodemask can come only
3893 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
3894 * when it does not intersect with the cpuset restrictions) or the
3895 * caller can deal with a violated nodemask.
3897 if (cpusets_enabled() && ac
->nodemask
&&
3898 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
3899 ac
->nodemask
= NULL
;
3904 * When updating a task's mems_allowed or mempolicy nodemask, it is
3905 * possible to race with parallel threads in such a way that our
3906 * allocation can fail while the mask is being updated. If we are about
3907 * to fail, check if the cpuset changed during allocation and if so,
3910 if (read_mems_allowed_retry(cpuset_mems_cookie
))
3916 static inline struct page
*
3917 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3918 struct alloc_context
*ac
)
3920 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3921 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
3922 struct page
*page
= NULL
;
3923 unsigned int alloc_flags
;
3924 unsigned long did_some_progress
;
3925 enum compact_priority compact_priority
;
3926 enum compact_result compact_result
;
3927 int compaction_retries
;
3928 int no_progress_loops
;
3929 unsigned int cpuset_mems_cookie
;
3933 * In the slowpath, we sanity check order to avoid ever trying to
3934 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3935 * be using allocators in order of preference for an area that is
3938 if (order
>= MAX_ORDER
) {
3939 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3944 * We also sanity check to catch abuse of atomic reserves being used by
3945 * callers that are not in atomic context.
3947 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3948 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3949 gfp_mask
&= ~__GFP_ATOMIC
;
3952 compaction_retries
= 0;
3953 no_progress_loops
= 0;
3954 compact_priority
= DEF_COMPACT_PRIORITY
;
3955 cpuset_mems_cookie
= read_mems_allowed_begin();
3958 * The fast path uses conservative alloc_flags to succeed only until
3959 * kswapd needs to be woken up, and to avoid the cost of setting up
3960 * alloc_flags precisely. So we do that now.
3962 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3965 * We need to recalculate the starting point for the zonelist iterator
3966 * because we might have used different nodemask in the fast path, or
3967 * there was a cpuset modification and we are retrying - otherwise we
3968 * could end up iterating over non-eligible zones endlessly.
3970 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3971 ac
->high_zoneidx
, ac
->nodemask
);
3972 if (!ac
->preferred_zoneref
->zone
)
3975 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3976 wake_all_kswapds(order
, ac
);
3979 * The adjusted alloc_flags might result in immediate success, so try
3982 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3987 * For costly allocations, try direct compaction first, as it's likely
3988 * that we have enough base pages and don't need to reclaim. For non-
3989 * movable high-order allocations, do that as well, as compaction will
3990 * try prevent permanent fragmentation by migrating from blocks of the
3992 * Don't try this for allocations that are allowed to ignore
3993 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
3995 if (can_direct_reclaim
&&
3997 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
3998 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
3999 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
4001 INIT_COMPACT_PRIORITY
,
4007 * Checks for costly allocations with __GFP_NORETRY, which
4008 * includes THP page fault allocations
4010 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
4012 * If compaction is deferred for high-order allocations,
4013 * it is because sync compaction recently failed. If
4014 * this is the case and the caller requested a THP
4015 * allocation, we do not want to heavily disrupt the
4016 * system, so we fail the allocation instead of entering
4019 if (compact_result
== COMPACT_DEFERRED
)
4023 * Looks like reclaim/compaction is worth trying, but
4024 * sync compaction could be very expensive, so keep
4025 * using async compaction.
4027 compact_priority
= INIT_COMPACT_PRIORITY
;
4032 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4033 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
4034 wake_all_kswapds(order
, ac
);
4036 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4038 alloc_flags
= reserve_flags
;
4041 * Reset the zonelist iterators if memory policies can be ignored.
4042 * These allocations are high priority and system rather than user
4045 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4046 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
4047 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4048 ac
->high_zoneidx
, ac
->nodemask
);
4051 /* Attempt with potentially adjusted zonelist and alloc_flags */
4052 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4056 /* Caller is not willing to reclaim, we can't balance anything */
4057 if (!can_direct_reclaim
)
4060 /* Avoid recursion of direct reclaim */
4061 if (current
->flags
& PF_MEMALLOC
)
4064 /* Try direct reclaim and then allocating */
4065 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4066 &did_some_progress
);
4070 /* Try direct compaction and then allocating */
4071 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4072 compact_priority
, &compact_result
);
4076 /* Do not loop if specifically requested */
4077 if (gfp_mask
& __GFP_NORETRY
)
4081 * Do not retry costly high order allocations unless they are
4082 * __GFP_RETRY_MAYFAIL
4084 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4087 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4088 did_some_progress
> 0, &no_progress_loops
))
4092 * It doesn't make any sense to retry for the compaction if the order-0
4093 * reclaim is not able to make any progress because the current
4094 * implementation of the compaction depends on the sufficient amount
4095 * of free memory (see __compaction_suitable)
4097 if (did_some_progress
> 0 &&
4098 should_compact_retry(ac
, order
, alloc_flags
,
4099 compact_result
, &compact_priority
,
4100 &compaction_retries
))
4104 /* Deal with possible cpuset update races before we start OOM killing */
4105 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4108 /* Reclaim has failed us, start killing things */
4109 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4113 /* Avoid allocations with no watermarks from looping endlessly */
4114 if (tsk_is_oom_victim(current
) &&
4115 (alloc_flags
== ALLOC_OOM
||
4116 (gfp_mask
& __GFP_NOMEMALLOC
)))
4119 /* Retry as long as the OOM killer is making progress */
4120 if (did_some_progress
) {
4121 no_progress_loops
= 0;
4126 /* Deal with possible cpuset update races before we fail */
4127 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4131 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4134 if (gfp_mask
& __GFP_NOFAIL
) {
4136 * All existing users of the __GFP_NOFAIL are blockable, so warn
4137 * of any new users that actually require GFP_NOWAIT
4139 if (WARN_ON_ONCE(!can_direct_reclaim
))
4143 * PF_MEMALLOC request from this context is rather bizarre
4144 * because we cannot reclaim anything and only can loop waiting
4145 * for somebody to do a work for us
4147 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4150 * non failing costly orders are a hard requirement which we
4151 * are not prepared for much so let's warn about these users
4152 * so that we can identify them and convert them to something
4155 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4158 * Help non-failing allocations by giving them access to memory
4159 * reserves but do not use ALLOC_NO_WATERMARKS because this
4160 * could deplete whole memory reserves which would just make
4161 * the situation worse
4163 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4171 warn_alloc(gfp_mask
, ac
->nodemask
,
4172 "page allocation failure: order:%u", order
);
4177 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4178 int preferred_nid
, nodemask_t
*nodemask
,
4179 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4180 unsigned int *alloc_flags
)
4182 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
4183 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4184 ac
->nodemask
= nodemask
;
4185 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
4187 if (cpusets_enabled()) {
4188 *alloc_mask
|= __GFP_HARDWALL
;
4190 ac
->nodemask
= &cpuset_current_mems_allowed
;
4192 *alloc_flags
|= ALLOC_CPUSET
;
4195 fs_reclaim_acquire(gfp_mask
);
4196 fs_reclaim_release(gfp_mask
);
4198 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4200 if (should_fail_alloc_page(gfp_mask
, order
))
4203 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
4204 *alloc_flags
|= ALLOC_CMA
;
4209 /* Determine whether to spread dirty pages and what the first usable zone */
4210 static inline void finalise_ac(gfp_t gfp_mask
,
4211 unsigned int order
, struct alloc_context
*ac
)
4213 /* Dirty zone balancing only done in the fast path */
4214 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4217 * The preferred zone is used for statistics but crucially it is
4218 * also used as the starting point for the zonelist iterator. It
4219 * may get reset for allocations that ignore memory policies.
4221 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4222 ac
->high_zoneidx
, ac
->nodemask
);
4226 * This is the 'heart' of the zoned buddy allocator.
4229 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4230 nodemask_t
*nodemask
)
4233 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4234 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4235 struct alloc_context ac
= { };
4237 gfp_mask
&= gfp_allowed_mask
;
4238 alloc_mask
= gfp_mask
;
4239 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4242 finalise_ac(gfp_mask
, order
, &ac
);
4244 /* First allocation attempt */
4245 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4250 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4251 * resp. GFP_NOIO which has to be inherited for all allocation requests
4252 * from a particular context which has been marked by
4253 * memalloc_no{fs,io}_{save,restore}.
4255 alloc_mask
= current_gfp_context(gfp_mask
);
4256 ac
.spread_dirty_pages
= false;
4259 * Restore the original nodemask if it was potentially replaced with
4260 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4262 if (unlikely(ac
.nodemask
!= nodemask
))
4263 ac
.nodemask
= nodemask
;
4265 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4268 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4269 unlikely(memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
4270 __free_pages(page
, order
);
4274 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4278 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4281 * Common helper functions.
4283 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4288 * __get_free_pages() returns a virtual address, which cannot represent
4291 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
4293 page
= alloc_pages(gfp_mask
, order
);
4296 return (unsigned long) page_address(page
);
4298 EXPORT_SYMBOL(__get_free_pages
);
4300 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4302 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4304 EXPORT_SYMBOL(get_zeroed_page
);
4306 void __free_pages(struct page
*page
, unsigned int order
)
4308 if (put_page_testzero(page
)) {
4310 free_unref_page(page
);
4312 __free_pages_ok(page
, order
);
4316 EXPORT_SYMBOL(__free_pages
);
4318 void free_pages(unsigned long addr
, unsigned int order
)
4321 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4322 __free_pages(virt_to_page((void *)addr
), order
);
4326 EXPORT_SYMBOL(free_pages
);
4330 * An arbitrary-length arbitrary-offset area of memory which resides
4331 * within a 0 or higher order page. Multiple fragments within that page
4332 * are individually refcounted, in the page's reference counter.
4334 * The page_frag functions below provide a simple allocation framework for
4335 * page fragments. This is used by the network stack and network device
4336 * drivers to provide a backing region of memory for use as either an
4337 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4339 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4342 struct page
*page
= NULL
;
4343 gfp_t gfp
= gfp_mask
;
4345 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4346 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4348 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4349 PAGE_FRAG_CACHE_MAX_ORDER
);
4350 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4352 if (unlikely(!page
))
4353 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4355 nc
->va
= page
? page_address(page
) : NULL
;
4360 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4362 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4364 if (page_ref_sub_and_test(page
, count
)) {
4365 unsigned int order
= compound_order(page
);
4368 free_unref_page(page
);
4370 __free_pages_ok(page
, order
);
4373 EXPORT_SYMBOL(__page_frag_cache_drain
);
4375 void *page_frag_alloc(struct page_frag_cache
*nc
,
4376 unsigned int fragsz
, gfp_t gfp_mask
)
4378 unsigned int size
= PAGE_SIZE
;
4382 if (unlikely(!nc
->va
)) {
4384 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4388 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4389 /* if size can vary use size else just use PAGE_SIZE */
4392 /* Even if we own the page, we do not use atomic_set().
4393 * This would break get_page_unless_zero() users.
4395 page_ref_add(page
, size
- 1);
4397 /* reset page count bias and offset to start of new frag */
4398 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4399 nc
->pagecnt_bias
= size
;
4403 offset
= nc
->offset
- fragsz
;
4404 if (unlikely(offset
< 0)) {
4405 page
= virt_to_page(nc
->va
);
4407 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4410 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4411 /* if size can vary use size else just use PAGE_SIZE */
4414 /* OK, page count is 0, we can safely set it */
4415 set_page_count(page
, size
);
4417 /* reset page count bias and offset to start of new frag */
4418 nc
->pagecnt_bias
= size
;
4419 offset
= size
- fragsz
;
4423 nc
->offset
= offset
;
4425 return nc
->va
+ offset
;
4427 EXPORT_SYMBOL(page_frag_alloc
);
4430 * Frees a page fragment allocated out of either a compound or order 0 page.
4432 void page_frag_free(void *addr
)
4434 struct page
*page
= virt_to_head_page(addr
);
4436 if (unlikely(put_page_testzero(page
)))
4437 __free_pages_ok(page
, compound_order(page
));
4439 EXPORT_SYMBOL(page_frag_free
);
4441 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4445 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4446 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4448 split_page(virt_to_page((void *)addr
), order
);
4449 while (used
< alloc_end
) {
4454 return (void *)addr
;
4458 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4459 * @size: the number of bytes to allocate
4460 * @gfp_mask: GFP flags for the allocation
4462 * This function is similar to alloc_pages(), except that it allocates the
4463 * minimum number of pages to satisfy the request. alloc_pages() can only
4464 * allocate memory in power-of-two pages.
4466 * This function is also limited by MAX_ORDER.
4468 * Memory allocated by this function must be released by free_pages_exact().
4470 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4472 unsigned int order
= get_order(size
);
4475 addr
= __get_free_pages(gfp_mask
, order
);
4476 return make_alloc_exact(addr
, order
, size
);
4478 EXPORT_SYMBOL(alloc_pages_exact
);
4481 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4483 * @nid: the preferred node ID where memory should be allocated
4484 * @size: the number of bytes to allocate
4485 * @gfp_mask: GFP flags for the allocation
4487 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4490 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4492 unsigned int order
= get_order(size
);
4493 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
4496 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4500 * free_pages_exact - release memory allocated via alloc_pages_exact()
4501 * @virt: the value returned by alloc_pages_exact.
4502 * @size: size of allocation, same value as passed to alloc_pages_exact().
4504 * Release the memory allocated by a previous call to alloc_pages_exact.
4506 void free_pages_exact(void *virt
, size_t size
)
4508 unsigned long addr
= (unsigned long)virt
;
4509 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4511 while (addr
< end
) {
4516 EXPORT_SYMBOL(free_pages_exact
);
4519 * nr_free_zone_pages - count number of pages beyond high watermark
4520 * @offset: The zone index of the highest zone
4522 * nr_free_zone_pages() counts the number of counts pages which are beyond the
4523 * high watermark within all zones at or below a given zone index. For each
4524 * zone, the number of pages is calculated as:
4526 * nr_free_zone_pages = managed_pages - high_pages
4528 static unsigned long nr_free_zone_pages(int offset
)
4533 /* Just pick one node, since fallback list is circular */
4534 unsigned long sum
= 0;
4536 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4538 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4539 unsigned long size
= zone
->managed_pages
;
4540 unsigned long high
= high_wmark_pages(zone
);
4549 * nr_free_buffer_pages - count number of pages beyond high watermark
4551 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4552 * watermark within ZONE_DMA and ZONE_NORMAL.
4554 unsigned long nr_free_buffer_pages(void)
4556 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4558 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4561 * nr_free_pagecache_pages - count number of pages beyond high watermark
4563 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4564 * high watermark within all zones.
4566 unsigned long nr_free_pagecache_pages(void)
4568 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4571 static inline void show_node(struct zone
*zone
)
4573 if (IS_ENABLED(CONFIG_NUMA
))
4574 printk("Node %d ", zone_to_nid(zone
));
4577 long si_mem_available(void)
4580 unsigned long pagecache
;
4581 unsigned long wmark_low
= 0;
4582 unsigned long pages
[NR_LRU_LISTS
];
4586 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
4587 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
4590 wmark_low
+= zone
->watermark
[WMARK_LOW
];
4593 * Estimate the amount of memory available for userspace allocations,
4594 * without causing swapping.
4596 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
4599 * Not all the page cache can be freed, otherwise the system will
4600 * start swapping. Assume at least half of the page cache, or the
4601 * low watermark worth of cache, needs to stay.
4603 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
4604 pagecache
-= min(pagecache
/ 2, wmark_low
);
4605 available
+= pagecache
;
4608 * Part of the reclaimable slab consists of items that are in use,
4609 * and cannot be freed. Cap this estimate at the low watermark.
4611 available
+= global_node_page_state(NR_SLAB_RECLAIMABLE
) -
4612 min(global_node_page_state(NR_SLAB_RECLAIMABLE
) / 2,
4619 EXPORT_SYMBOL_GPL(si_mem_available
);
4621 void si_meminfo(struct sysinfo
*val
)
4623 val
->totalram
= totalram_pages
;
4624 val
->sharedram
= global_node_page_state(NR_SHMEM
);
4625 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
4626 val
->bufferram
= nr_blockdev_pages();
4627 val
->totalhigh
= totalhigh_pages
;
4628 val
->freehigh
= nr_free_highpages();
4629 val
->mem_unit
= PAGE_SIZE
;
4632 EXPORT_SYMBOL(si_meminfo
);
4635 void si_meminfo_node(struct sysinfo
*val
, int nid
)
4637 int zone_type
; /* needs to be signed */
4638 unsigned long managed_pages
= 0;
4639 unsigned long managed_highpages
= 0;
4640 unsigned long free_highpages
= 0;
4641 pg_data_t
*pgdat
= NODE_DATA(nid
);
4643 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
4644 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
4645 val
->totalram
= managed_pages
;
4646 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
4647 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
4648 #ifdef CONFIG_HIGHMEM
4649 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
4650 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4652 if (is_highmem(zone
)) {
4653 managed_highpages
+= zone
->managed_pages
;
4654 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
4657 val
->totalhigh
= managed_highpages
;
4658 val
->freehigh
= free_highpages
;
4660 val
->totalhigh
= managed_highpages
;
4661 val
->freehigh
= free_highpages
;
4663 val
->mem_unit
= PAGE_SIZE
;
4668 * Determine whether the node should be displayed or not, depending on whether
4669 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4671 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
4673 if (!(flags
& SHOW_MEM_FILTER_NODES
))
4677 * no node mask - aka implicit memory numa policy. Do not bother with
4678 * the synchronization - read_mems_allowed_begin - because we do not
4679 * have to be precise here.
4682 nodemask
= &cpuset_current_mems_allowed
;
4684 return !node_isset(nid
, *nodemask
);
4687 #define K(x) ((x) << (PAGE_SHIFT-10))
4689 static void show_migration_types(unsigned char type
)
4691 static const char types
[MIGRATE_TYPES
] = {
4692 [MIGRATE_UNMOVABLE
] = 'U',
4693 [MIGRATE_MOVABLE
] = 'M',
4694 [MIGRATE_RECLAIMABLE
] = 'E',
4695 [MIGRATE_HIGHATOMIC
] = 'H',
4697 [MIGRATE_CMA
] = 'C',
4699 #ifdef CONFIG_MEMORY_ISOLATION
4700 [MIGRATE_ISOLATE
] = 'I',
4703 char tmp
[MIGRATE_TYPES
+ 1];
4707 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
4708 if (type
& (1 << i
))
4713 printk(KERN_CONT
"(%s) ", tmp
);
4717 * Show free area list (used inside shift_scroll-lock stuff)
4718 * We also calculate the percentage fragmentation. We do this by counting the
4719 * memory on each free list with the exception of the first item on the list.
4722 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4725 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
4727 unsigned long free_pcp
= 0;
4732 for_each_populated_zone(zone
) {
4733 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4736 for_each_online_cpu(cpu
)
4737 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4740 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4741 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4742 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4743 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4744 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4745 " free:%lu free_pcp:%lu free_cma:%lu\n",
4746 global_node_page_state(NR_ACTIVE_ANON
),
4747 global_node_page_state(NR_INACTIVE_ANON
),
4748 global_node_page_state(NR_ISOLATED_ANON
),
4749 global_node_page_state(NR_ACTIVE_FILE
),
4750 global_node_page_state(NR_INACTIVE_FILE
),
4751 global_node_page_state(NR_ISOLATED_FILE
),
4752 global_node_page_state(NR_UNEVICTABLE
),
4753 global_node_page_state(NR_FILE_DIRTY
),
4754 global_node_page_state(NR_WRITEBACK
),
4755 global_node_page_state(NR_UNSTABLE_NFS
),
4756 global_node_page_state(NR_SLAB_RECLAIMABLE
),
4757 global_node_page_state(NR_SLAB_UNRECLAIMABLE
),
4758 global_node_page_state(NR_FILE_MAPPED
),
4759 global_node_page_state(NR_SHMEM
),
4760 global_zone_page_state(NR_PAGETABLE
),
4761 global_zone_page_state(NR_BOUNCE
),
4762 global_zone_page_state(NR_FREE_PAGES
),
4764 global_zone_page_state(NR_FREE_CMA_PAGES
));
4766 for_each_online_pgdat(pgdat
) {
4767 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
4771 " active_anon:%lukB"
4772 " inactive_anon:%lukB"
4773 " active_file:%lukB"
4774 " inactive_file:%lukB"
4775 " unevictable:%lukB"
4776 " isolated(anon):%lukB"
4777 " isolated(file):%lukB"
4782 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4784 " shmem_pmdmapped: %lukB"
4787 " writeback_tmp:%lukB"
4789 " all_unreclaimable? %s"
4792 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
4793 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
4794 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
4795 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
4796 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
4797 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
4798 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
4799 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
4800 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
4801 K(node_page_state(pgdat
, NR_WRITEBACK
)),
4802 K(node_page_state(pgdat
, NR_SHMEM
)),
4803 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
4804 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
4805 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
4807 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
4809 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
4810 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
4811 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
4815 for_each_populated_zone(zone
) {
4818 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4822 for_each_online_cpu(cpu
)
4823 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
4832 " active_anon:%lukB"
4833 " inactive_anon:%lukB"
4834 " active_file:%lukB"
4835 " inactive_file:%lukB"
4836 " unevictable:%lukB"
4837 " writepending:%lukB"
4841 " kernel_stack:%lukB"
4849 K(zone_page_state(zone
, NR_FREE_PAGES
)),
4850 K(min_wmark_pages(zone
)),
4851 K(low_wmark_pages(zone
)),
4852 K(high_wmark_pages(zone
)),
4853 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
4854 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
4855 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
4856 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
4857 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
4858 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
4859 K(zone
->present_pages
),
4860 K(zone
->managed_pages
),
4861 K(zone_page_state(zone
, NR_MLOCK
)),
4862 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
4863 K(zone_page_state(zone
, NR_PAGETABLE
)),
4864 K(zone_page_state(zone
, NR_BOUNCE
)),
4866 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
4867 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
4868 printk("lowmem_reserve[]:");
4869 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4870 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
4871 printk(KERN_CONT
"\n");
4874 for_each_populated_zone(zone
) {
4876 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4877 unsigned char types
[MAX_ORDER
];
4879 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
4882 printk(KERN_CONT
"%s: ", zone
->name
);
4884 spin_lock_irqsave(&zone
->lock
, flags
);
4885 for (order
= 0; order
< MAX_ORDER
; order
++) {
4886 struct free_area
*area
= &zone
->free_area
[order
];
4889 nr
[order
] = area
->nr_free
;
4890 total
+= nr
[order
] << order
;
4893 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4894 if (!list_empty(&area
->free_list
[type
]))
4895 types
[order
] |= 1 << type
;
4898 spin_unlock_irqrestore(&zone
->lock
, flags
);
4899 for (order
= 0; order
< MAX_ORDER
; order
++) {
4900 printk(KERN_CONT
"%lu*%lukB ",
4901 nr
[order
], K(1UL) << order
);
4903 show_migration_types(types
[order
]);
4905 printk(KERN_CONT
"= %lukB\n", K(total
));
4908 hugetlb_show_meminfo();
4910 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
4912 show_swap_cache_info();
4915 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4917 zoneref
->zone
= zone
;
4918 zoneref
->zone_idx
= zone_idx(zone
);
4922 * Builds allocation fallback zone lists.
4924 * Add all populated zones of a node to the zonelist.
4926 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
4929 enum zone_type zone_type
= MAX_NR_ZONES
;
4934 zone
= pgdat
->node_zones
+ zone_type
;
4935 if (managed_zone(zone
)) {
4936 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
4937 check_highest_zone(zone_type
);
4939 } while (zone_type
);
4946 static int __parse_numa_zonelist_order(char *s
)
4949 * We used to support different zonlists modes but they turned
4950 * out to be just not useful. Let's keep the warning in place
4951 * if somebody still use the cmd line parameter so that we do
4952 * not fail it silently
4954 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
4955 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
4961 static __init
int setup_numa_zonelist_order(char *s
)
4966 return __parse_numa_zonelist_order(s
);
4968 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4970 char numa_zonelist_order
[] = "Node";
4973 * sysctl handler for numa_zonelist_order
4975 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4976 void __user
*buffer
, size_t *length
,
4983 return proc_dostring(table
, write
, buffer
, length
, ppos
);
4984 str
= memdup_user_nul(buffer
, 16);
4986 return PTR_ERR(str
);
4988 ret
= __parse_numa_zonelist_order(str
);
4994 #define MAX_NODE_LOAD (nr_online_nodes)
4995 static int node_load
[MAX_NUMNODES
];
4998 * find_next_best_node - find the next node that should appear in a given node's fallback list
4999 * @node: node whose fallback list we're appending
5000 * @used_node_mask: nodemask_t of already used nodes
5002 * We use a number of factors to determine which is the next node that should
5003 * appear on a given node's fallback list. The node should not have appeared
5004 * already in @node's fallback list, and it should be the next closest node
5005 * according to the distance array (which contains arbitrary distance values
5006 * from each node to each node in the system), and should also prefer nodes
5007 * with no CPUs, since presumably they'll have very little allocation pressure
5008 * on them otherwise.
5009 * It returns -1 if no node is found.
5011 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
5014 int min_val
= INT_MAX
;
5015 int best_node
= NUMA_NO_NODE
;
5016 const struct cpumask
*tmp
= cpumask_of_node(0);
5018 /* Use the local node if we haven't already */
5019 if (!node_isset(node
, *used_node_mask
)) {
5020 node_set(node
, *used_node_mask
);
5024 for_each_node_state(n
, N_MEMORY
) {
5026 /* Don't want a node to appear more than once */
5027 if (node_isset(n
, *used_node_mask
))
5030 /* Use the distance array to find the distance */
5031 val
= node_distance(node
, n
);
5033 /* Penalize nodes under us ("prefer the next node") */
5036 /* Give preference to headless and unused nodes */
5037 tmp
= cpumask_of_node(n
);
5038 if (!cpumask_empty(tmp
))
5039 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
5041 /* Slight preference for less loaded node */
5042 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
5043 val
+= node_load
[n
];
5045 if (val
< min_val
) {
5052 node_set(best_node
, *used_node_mask
);
5059 * Build zonelists ordered by node and zones within node.
5060 * This results in maximum locality--normal zone overflows into local
5061 * DMA zone, if any--but risks exhausting DMA zone.
5063 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5066 struct zoneref
*zonerefs
;
5069 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5071 for (i
= 0; i
< nr_nodes
; i
++) {
5074 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5076 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5077 zonerefs
+= nr_zones
;
5079 zonerefs
->zone
= NULL
;
5080 zonerefs
->zone_idx
= 0;
5084 * Build gfp_thisnode zonelists
5086 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5088 struct zoneref
*zonerefs
;
5091 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5092 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5093 zonerefs
+= nr_zones
;
5094 zonerefs
->zone
= NULL
;
5095 zonerefs
->zone_idx
= 0;
5099 * Build zonelists ordered by zone and nodes within zones.
5100 * This results in conserving DMA zone[s] until all Normal memory is
5101 * exhausted, but results in overflowing to remote node while memory
5102 * may still exist in local DMA zone.
5105 static void build_zonelists(pg_data_t
*pgdat
)
5107 static int node_order
[MAX_NUMNODES
];
5108 int node
, load
, nr_nodes
= 0;
5109 nodemask_t used_mask
;
5110 int local_node
, prev_node
;
5112 /* NUMA-aware ordering of nodes */
5113 local_node
= pgdat
->node_id
;
5114 load
= nr_online_nodes
;
5115 prev_node
= local_node
;
5116 nodes_clear(used_mask
);
5118 memset(node_order
, 0, sizeof(node_order
));
5119 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5121 * We don't want to pressure a particular node.
5122 * So adding penalty to the first node in same
5123 * distance group to make it round-robin.
5125 if (node_distance(local_node
, node
) !=
5126 node_distance(local_node
, prev_node
))
5127 node_load
[node
] = load
;
5129 node_order
[nr_nodes
++] = node
;
5134 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5135 build_thisnode_zonelists(pgdat
);
5138 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5140 * Return node id of node used for "local" allocations.
5141 * I.e., first node id of first zone in arg node's generic zonelist.
5142 * Used for initializing percpu 'numa_mem', which is used primarily
5143 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5145 int local_memory_node(int node
)
5149 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5150 gfp_zone(GFP_KERNEL
),
5152 return z
->zone
->node
;
5156 static void setup_min_unmapped_ratio(void);
5157 static void setup_min_slab_ratio(void);
5158 #else /* CONFIG_NUMA */
5160 static void build_zonelists(pg_data_t
*pgdat
)
5162 int node
, local_node
;
5163 struct zoneref
*zonerefs
;
5166 local_node
= pgdat
->node_id
;
5168 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5169 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5170 zonerefs
+= nr_zones
;
5173 * Now we build the zonelist so that it contains the zones
5174 * of all the other nodes.
5175 * We don't want to pressure a particular node, so when
5176 * building the zones for node N, we make sure that the
5177 * zones coming right after the local ones are those from
5178 * node N+1 (modulo N)
5180 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5181 if (!node_online(node
))
5183 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5184 zonerefs
+= nr_zones
;
5186 for (node
= 0; node
< local_node
; node
++) {
5187 if (!node_online(node
))
5189 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5190 zonerefs
+= nr_zones
;
5193 zonerefs
->zone
= NULL
;
5194 zonerefs
->zone_idx
= 0;
5197 #endif /* CONFIG_NUMA */
5200 * Boot pageset table. One per cpu which is going to be used for all
5201 * zones and all nodes. The parameters will be set in such a way
5202 * that an item put on a list will immediately be handed over to
5203 * the buddy list. This is safe since pageset manipulation is done
5204 * with interrupts disabled.
5206 * The boot_pagesets must be kept even after bootup is complete for
5207 * unused processors and/or zones. They do play a role for bootstrapping
5208 * hotplugged processors.
5210 * zoneinfo_show() and maybe other functions do
5211 * not check if the processor is online before following the pageset pointer.
5212 * Other parts of the kernel may not check if the zone is available.
5214 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5215 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5216 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5218 static void __build_all_zonelists(void *data
)
5221 int __maybe_unused cpu
;
5222 pg_data_t
*self
= data
;
5223 static DEFINE_SPINLOCK(lock
);
5228 memset(node_load
, 0, sizeof(node_load
));
5232 * This node is hotadded and no memory is yet present. So just
5233 * building zonelists is fine - no need to touch other nodes.
5235 if (self
&& !node_online(self
->node_id
)) {
5236 build_zonelists(self
);
5238 for_each_online_node(nid
) {
5239 pg_data_t
*pgdat
= NODE_DATA(nid
);
5241 build_zonelists(pgdat
);
5244 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5246 * We now know the "local memory node" for each node--
5247 * i.e., the node of the first zone in the generic zonelist.
5248 * Set up numa_mem percpu variable for on-line cpus. During
5249 * boot, only the boot cpu should be on-line; we'll init the
5250 * secondary cpus' numa_mem as they come on-line. During
5251 * node/memory hotplug, we'll fixup all on-line cpus.
5253 for_each_online_cpu(cpu
)
5254 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5261 static noinline
void __init
5262 build_all_zonelists_init(void)
5266 __build_all_zonelists(NULL
);
5269 * Initialize the boot_pagesets that are going to be used
5270 * for bootstrapping processors. The real pagesets for
5271 * each zone will be allocated later when the per cpu
5272 * allocator is available.
5274 * boot_pagesets are used also for bootstrapping offline
5275 * cpus if the system is already booted because the pagesets
5276 * are needed to initialize allocators on a specific cpu too.
5277 * F.e. the percpu allocator needs the page allocator which
5278 * needs the percpu allocator in order to allocate its pagesets
5279 * (a chicken-egg dilemma).
5281 for_each_possible_cpu(cpu
)
5282 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5284 mminit_verify_zonelist();
5285 cpuset_init_current_mems_allowed();
5289 * unless system_state == SYSTEM_BOOTING.
5291 * __ref due to call of __init annotated helper build_all_zonelists_init
5292 * [protected by SYSTEM_BOOTING].
5294 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
5296 if (system_state
== SYSTEM_BOOTING
) {
5297 build_all_zonelists_init();
5299 __build_all_zonelists(pgdat
);
5300 /* cpuset refresh routine should be here */
5302 vm_total_pages
= nr_free_pagecache_pages();
5304 * Disable grouping by mobility if the number of pages in the
5305 * system is too low to allow the mechanism to work. It would be
5306 * more accurate, but expensive to check per-zone. This check is
5307 * made on memory-hotadd so a system can start with mobility
5308 * disabled and enable it later
5310 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5311 page_group_by_mobility_disabled
= 1;
5313 page_group_by_mobility_disabled
= 0;
5315 pr_info("Built %i zonelists, mobility grouping %s. Total pages: %ld\n",
5317 page_group_by_mobility_disabled
? "off" : "on",
5320 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5325 * Initially all pages are reserved - free ones are freed
5326 * up by free_all_bootmem() once the early boot process is
5327 * done. Non-atomic initialization, single-pass.
5329 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5330 unsigned long start_pfn
, enum memmap_context context
,
5331 struct vmem_altmap
*altmap
)
5333 unsigned long end_pfn
= start_pfn
+ size
;
5334 pg_data_t
*pgdat
= NODE_DATA(nid
);
5336 unsigned long nr_initialised
= 0;
5337 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5338 struct memblock_region
*r
= NULL
, *tmp
;
5341 if (highest_memmap_pfn
< end_pfn
- 1)
5342 highest_memmap_pfn
= end_pfn
- 1;
5345 * Honor reservation requested by the driver for this ZONE_DEVICE
5348 if (altmap
&& start_pfn
== altmap
->base_pfn
)
5349 start_pfn
+= altmap
->reserve
;
5351 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5353 * There can be holes in boot-time mem_map[]s handed to this
5354 * function. They do not exist on hotplugged memory.
5356 if (context
!= MEMMAP_EARLY
)
5359 if (!early_pfn_valid(pfn
)) {
5360 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5362 * Skip to the pfn preceding the next valid one (or
5363 * end_pfn), such that we hit a valid pfn (or end_pfn)
5364 * on our next iteration of the loop.
5366 pfn
= memblock_next_valid_pfn(pfn
, end_pfn
) - 1;
5370 if (!early_pfn_in_nid(pfn
, nid
))
5372 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
5375 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5377 * Check given memblock attribute by firmware which can affect
5378 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
5379 * mirrored, it's an overlapped memmap init. skip it.
5381 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5382 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
5383 for_each_memblock(memory
, tmp
)
5384 if (pfn
< memblock_region_memory_end_pfn(tmp
))
5388 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
5389 memblock_is_mirror(r
)) {
5390 /* already initialized as NORMAL */
5391 pfn
= memblock_region_memory_end_pfn(r
);
5399 * Mark the block movable so that blocks are reserved for
5400 * movable at startup. This will force kernel allocations
5401 * to reserve their blocks rather than leaking throughout
5402 * the address space during boot when many long-lived
5403 * kernel allocations are made.
5405 * bitmap is created for zone's valid pfn range. but memmap
5406 * can be created for invalid pages (for alignment)
5407 * check here not to call set_pageblock_migratetype() against
5410 * Please note that MEMMAP_HOTPLUG path doesn't clear memmap
5411 * because this is done early in sparse_add_one_section
5413 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5414 struct page
*page
= pfn_to_page(pfn
);
5416 __init_single_page(page
, pfn
, zone
, nid
,
5417 context
!= MEMMAP_HOTPLUG
);
5418 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5421 __init_single_pfn(pfn
, zone
, nid
,
5422 context
!= MEMMAP_HOTPLUG
);
5427 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5429 unsigned int order
, t
;
5430 for_each_migratetype_order(order
, t
) {
5431 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5432 zone
->free_area
[order
].nr_free
= 0;
5436 #ifndef __HAVE_ARCH_MEMMAP_INIT
5437 #define memmap_init(size, nid, zone, start_pfn) \
5438 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY, NULL)
5441 static int zone_batchsize(struct zone
*zone
)
5447 * The per-cpu-pages pools are set to around 1000th of the
5448 * size of the zone. But no more than 1/2 of a meg.
5450 * OK, so we don't know how big the cache is. So guess.
5452 batch
= zone
->managed_pages
/ 1024;
5453 if (batch
* PAGE_SIZE
> 512 * 1024)
5454 batch
= (512 * 1024) / PAGE_SIZE
;
5455 batch
/= 4; /* We effectively *= 4 below */
5460 * Clamp the batch to a 2^n - 1 value. Having a power
5461 * of 2 value was found to be more likely to have
5462 * suboptimal cache aliasing properties in some cases.
5464 * For example if 2 tasks are alternately allocating
5465 * batches of pages, one task can end up with a lot
5466 * of pages of one half of the possible page colors
5467 * and the other with pages of the other colors.
5469 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5474 /* The deferral and batching of frees should be suppressed under NOMMU
5477 * The problem is that NOMMU needs to be able to allocate large chunks
5478 * of contiguous memory as there's no hardware page translation to
5479 * assemble apparent contiguous memory from discontiguous pages.
5481 * Queueing large contiguous runs of pages for batching, however,
5482 * causes the pages to actually be freed in smaller chunks. As there
5483 * can be a significant delay between the individual batches being
5484 * recycled, this leads to the once large chunks of space being
5485 * fragmented and becoming unavailable for high-order allocations.
5492 * pcp->high and pcp->batch values are related and dependent on one another:
5493 * ->batch must never be higher then ->high.
5494 * The following function updates them in a safe manner without read side
5497 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5498 * those fields changing asynchronously (acording the the above rule).
5500 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5501 * outside of boot time (or some other assurance that no concurrent updaters
5504 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
5505 unsigned long batch
)
5507 /* start with a fail safe value for batch */
5511 /* Update high, then batch, in order */
5518 /* a companion to pageset_set_high() */
5519 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
5521 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
5524 static void pageset_init(struct per_cpu_pageset
*p
)
5526 struct per_cpu_pages
*pcp
;
5529 memset(p
, 0, sizeof(*p
));
5533 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
5534 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
5537 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
5540 pageset_set_batch(p
, batch
);
5544 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5545 * to the value high for the pageset p.
5547 static void pageset_set_high(struct per_cpu_pageset
*p
,
5550 unsigned long batch
= max(1UL, high
/ 4);
5551 if ((high
/ 4) > (PAGE_SHIFT
* 8))
5552 batch
= PAGE_SHIFT
* 8;
5554 pageset_update(&p
->pcp
, high
, batch
);
5557 static void pageset_set_high_and_batch(struct zone
*zone
,
5558 struct per_cpu_pageset
*pcp
)
5560 if (percpu_pagelist_fraction
)
5561 pageset_set_high(pcp
,
5562 (zone
->managed_pages
/
5563 percpu_pagelist_fraction
));
5565 pageset_set_batch(pcp
, zone_batchsize(zone
));
5568 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
5570 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
5573 pageset_set_high_and_batch(zone
, pcp
);
5576 void __meminit
setup_zone_pageset(struct zone
*zone
)
5579 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
5580 for_each_possible_cpu(cpu
)
5581 zone_pageset_init(zone
, cpu
);
5585 * Allocate per cpu pagesets and initialize them.
5586 * Before this call only boot pagesets were available.
5588 void __init
setup_per_cpu_pageset(void)
5590 struct pglist_data
*pgdat
;
5593 for_each_populated_zone(zone
)
5594 setup_zone_pageset(zone
);
5596 for_each_online_pgdat(pgdat
)
5597 pgdat
->per_cpu_nodestats
=
5598 alloc_percpu(struct per_cpu_nodestat
);
5601 static __meminit
void zone_pcp_init(struct zone
*zone
)
5604 * per cpu subsystem is not up at this point. The following code
5605 * relies on the ability of the linker to provide the
5606 * offset of a (static) per cpu variable into the per cpu area.
5608 zone
->pageset
= &boot_pageset
;
5610 if (populated_zone(zone
))
5611 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
5612 zone
->name
, zone
->present_pages
,
5613 zone_batchsize(zone
));
5616 void __meminit
init_currently_empty_zone(struct zone
*zone
,
5617 unsigned long zone_start_pfn
,
5620 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5622 pgdat
->nr_zones
= zone_idx(zone
) + 1;
5624 zone
->zone_start_pfn
= zone_start_pfn
;
5626 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
5627 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5629 (unsigned long)zone_idx(zone
),
5630 zone_start_pfn
, (zone_start_pfn
+ size
));
5632 zone_init_free_lists(zone
);
5633 zone
->initialized
= 1;
5636 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5637 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5640 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5642 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5643 struct mminit_pfnnid_cache
*state
)
5645 unsigned long start_pfn
, end_pfn
;
5648 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5649 return state
->last_nid
;
5651 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5653 state
->last_start
= start_pfn
;
5654 state
->last_end
= end_pfn
;
5655 state
->last_nid
= nid
;
5660 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5663 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5664 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5665 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5667 * If an architecture guarantees that all ranges registered contain no holes
5668 * and may be freed, this this function may be used instead of calling
5669 * memblock_free_early_nid() manually.
5671 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5673 unsigned long start_pfn
, end_pfn
;
5676 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5677 start_pfn
= min(start_pfn
, max_low_pfn
);
5678 end_pfn
= min(end_pfn
, max_low_pfn
);
5680 if (start_pfn
< end_pfn
)
5681 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5682 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5688 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5689 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5691 * If an architecture guarantees that all ranges registered contain no holes and may
5692 * be freed, this function may be used instead of calling memory_present() manually.
5694 void __init
sparse_memory_present_with_active_regions(int nid
)
5696 unsigned long start_pfn
, end_pfn
;
5699 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5700 memory_present(this_nid
, start_pfn
, end_pfn
);
5704 * get_pfn_range_for_nid - Return the start and end page frames for a node
5705 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5706 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5707 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5709 * It returns the start and end page frame of a node based on information
5710 * provided by memblock_set_node(). If called for a node
5711 * with no available memory, a warning is printed and the start and end
5714 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5715 unsigned long *start_pfn
, unsigned long *end_pfn
)
5717 unsigned long this_start_pfn
, this_end_pfn
;
5723 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5724 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5725 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5728 if (*start_pfn
== -1UL)
5733 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5734 * assumption is made that zones within a node are ordered in monotonic
5735 * increasing memory addresses so that the "highest" populated zone is used
5737 static void __init
find_usable_zone_for_movable(void)
5740 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5741 if (zone_index
== ZONE_MOVABLE
)
5744 if (arch_zone_highest_possible_pfn
[zone_index
] >
5745 arch_zone_lowest_possible_pfn
[zone_index
])
5749 VM_BUG_ON(zone_index
== -1);
5750 movable_zone
= zone_index
;
5754 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5755 * because it is sized independent of architecture. Unlike the other zones,
5756 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5757 * in each node depending on the size of each node and how evenly kernelcore
5758 * is distributed. This helper function adjusts the zone ranges
5759 * provided by the architecture for a given node by using the end of the
5760 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5761 * zones within a node are in order of monotonic increases memory addresses
5763 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5764 unsigned long zone_type
,
5765 unsigned long node_start_pfn
,
5766 unsigned long node_end_pfn
,
5767 unsigned long *zone_start_pfn
,
5768 unsigned long *zone_end_pfn
)
5770 /* Only adjust if ZONE_MOVABLE is on this node */
5771 if (zone_movable_pfn
[nid
]) {
5772 /* Size ZONE_MOVABLE */
5773 if (zone_type
== ZONE_MOVABLE
) {
5774 *zone_start_pfn
= zone_movable_pfn
[nid
];
5775 *zone_end_pfn
= min(node_end_pfn
,
5776 arch_zone_highest_possible_pfn
[movable_zone
]);
5778 /* Adjust for ZONE_MOVABLE starting within this range */
5779 } else if (!mirrored_kernelcore
&&
5780 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
5781 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5782 *zone_end_pfn
= zone_movable_pfn
[nid
];
5784 /* Check if this whole range is within ZONE_MOVABLE */
5785 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5786 *zone_start_pfn
= *zone_end_pfn
;
5791 * Return the number of pages a zone spans in a node, including holes
5792 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5794 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5795 unsigned long zone_type
,
5796 unsigned long node_start_pfn
,
5797 unsigned long node_end_pfn
,
5798 unsigned long *zone_start_pfn
,
5799 unsigned long *zone_end_pfn
,
5800 unsigned long *ignored
)
5802 /* When hotadd a new node from cpu_up(), the node should be empty */
5803 if (!node_start_pfn
&& !node_end_pfn
)
5806 /* Get the start and end of the zone */
5807 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5808 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5809 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5810 node_start_pfn
, node_end_pfn
,
5811 zone_start_pfn
, zone_end_pfn
);
5813 /* Check that this node has pages within the zone's required range */
5814 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5817 /* Move the zone boundaries inside the node if necessary */
5818 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5819 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5821 /* Return the spanned pages */
5822 return *zone_end_pfn
- *zone_start_pfn
;
5826 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5827 * then all holes in the requested range will be accounted for.
5829 unsigned long __meminit
__absent_pages_in_range(int nid
,
5830 unsigned long range_start_pfn
,
5831 unsigned long range_end_pfn
)
5833 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5834 unsigned long start_pfn
, end_pfn
;
5837 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5838 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5839 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5840 nr_absent
-= end_pfn
- start_pfn
;
5846 * absent_pages_in_range - Return number of page frames in holes within a range
5847 * @start_pfn: The start PFN to start searching for holes
5848 * @end_pfn: The end PFN to stop searching for holes
5850 * It returns the number of pages frames in memory holes within a range.
5852 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5853 unsigned long end_pfn
)
5855 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5858 /* Return the number of page frames in holes in a zone on a node */
5859 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5860 unsigned long zone_type
,
5861 unsigned long node_start_pfn
,
5862 unsigned long node_end_pfn
,
5863 unsigned long *ignored
)
5865 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5866 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5867 unsigned long zone_start_pfn
, zone_end_pfn
;
5868 unsigned long nr_absent
;
5870 /* When hotadd a new node from cpu_up(), the node should be empty */
5871 if (!node_start_pfn
&& !node_end_pfn
)
5874 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5875 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5877 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5878 node_start_pfn
, node_end_pfn
,
5879 &zone_start_pfn
, &zone_end_pfn
);
5880 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5883 * ZONE_MOVABLE handling.
5884 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5887 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
5888 unsigned long start_pfn
, end_pfn
;
5889 struct memblock_region
*r
;
5891 for_each_memblock(memory
, r
) {
5892 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5893 zone_start_pfn
, zone_end_pfn
);
5894 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5895 zone_start_pfn
, zone_end_pfn
);
5897 if (zone_type
== ZONE_MOVABLE
&&
5898 memblock_is_mirror(r
))
5899 nr_absent
+= end_pfn
- start_pfn
;
5901 if (zone_type
== ZONE_NORMAL
&&
5902 !memblock_is_mirror(r
))
5903 nr_absent
+= end_pfn
- start_pfn
;
5910 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5911 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5912 unsigned long zone_type
,
5913 unsigned long node_start_pfn
,
5914 unsigned long node_end_pfn
,
5915 unsigned long *zone_start_pfn
,
5916 unsigned long *zone_end_pfn
,
5917 unsigned long *zones_size
)
5921 *zone_start_pfn
= node_start_pfn
;
5922 for (zone
= 0; zone
< zone_type
; zone
++)
5923 *zone_start_pfn
+= zones_size
[zone
];
5925 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5927 return zones_size
[zone_type
];
5930 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5931 unsigned long zone_type
,
5932 unsigned long node_start_pfn
,
5933 unsigned long node_end_pfn
,
5934 unsigned long *zholes_size
)
5939 return zholes_size
[zone_type
];
5942 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5944 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5945 unsigned long node_start_pfn
,
5946 unsigned long node_end_pfn
,
5947 unsigned long *zones_size
,
5948 unsigned long *zholes_size
)
5950 unsigned long realtotalpages
= 0, totalpages
= 0;
5953 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5954 struct zone
*zone
= pgdat
->node_zones
+ i
;
5955 unsigned long zone_start_pfn
, zone_end_pfn
;
5956 unsigned long size
, real_size
;
5958 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5964 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5965 node_start_pfn
, node_end_pfn
,
5968 zone
->zone_start_pfn
= zone_start_pfn
;
5970 zone
->zone_start_pfn
= 0;
5971 zone
->spanned_pages
= size
;
5972 zone
->present_pages
= real_size
;
5975 realtotalpages
+= real_size
;
5978 pgdat
->node_spanned_pages
= totalpages
;
5979 pgdat
->node_present_pages
= realtotalpages
;
5980 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5984 #ifndef CONFIG_SPARSEMEM
5986 * Calculate the size of the zone->blockflags rounded to an unsigned long
5987 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5988 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5989 * round what is now in bits to nearest long in bits, then return it in
5992 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5994 unsigned long usemapsize
;
5996 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5997 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5998 usemapsize
= usemapsize
>> pageblock_order
;
5999 usemapsize
*= NR_PAGEBLOCK_BITS
;
6000 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
6002 return usemapsize
/ 8;
6005 static void __init
setup_usemap(struct pglist_data
*pgdat
,
6007 unsigned long zone_start_pfn
,
6008 unsigned long zonesize
)
6010 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
6011 zone
->pageblock_flags
= NULL
;
6013 zone
->pageblock_flags
=
6014 memblock_virt_alloc_node_nopanic(usemapsize
,
6018 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
6019 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
6020 #endif /* CONFIG_SPARSEMEM */
6022 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6024 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6025 void __paginginit
set_pageblock_order(void)
6029 /* Check that pageblock_nr_pages has not already been setup */
6030 if (pageblock_order
)
6033 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6034 order
= HUGETLB_PAGE_ORDER
;
6036 order
= MAX_ORDER
- 1;
6039 * Assume the largest contiguous order of interest is a huge page.
6040 * This value may be variable depending on boot parameters on IA64 and
6043 pageblock_order
= order
;
6045 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6048 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6049 * is unused as pageblock_order is set at compile-time. See
6050 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6053 void __paginginit
set_pageblock_order(void)
6057 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6059 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
6060 unsigned long present_pages
)
6062 unsigned long pages
= spanned_pages
;
6065 * Provide a more accurate estimation if there are holes within
6066 * the zone and SPARSEMEM is in use. If there are holes within the
6067 * zone, each populated memory region may cost us one or two extra
6068 * memmap pages due to alignment because memmap pages for each
6069 * populated regions may not be naturally aligned on page boundary.
6070 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6072 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6073 IS_ENABLED(CONFIG_SPARSEMEM
))
6074 pages
= present_pages
;
6076 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6080 * Set up the zone data structures:
6081 * - mark all pages reserved
6082 * - mark all memory queues empty
6083 * - clear the memory bitmaps
6085 * NOTE: pgdat should get zeroed by caller.
6087 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
6090 int nid
= pgdat
->node_id
;
6092 pgdat_resize_init(pgdat
);
6093 #ifdef CONFIG_NUMA_BALANCING
6094 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
6095 pgdat
->numabalancing_migrate_nr_pages
= 0;
6096 pgdat
->numabalancing_migrate_next_window
= jiffies
;
6098 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6099 spin_lock_init(&pgdat
->split_queue_lock
);
6100 INIT_LIST_HEAD(&pgdat
->split_queue
);
6101 pgdat
->split_queue_len
= 0;
6103 init_waitqueue_head(&pgdat
->kswapd_wait
);
6104 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6105 #ifdef CONFIG_COMPACTION
6106 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6108 pgdat_page_ext_init(pgdat
);
6109 spin_lock_init(&pgdat
->lru_lock
);
6110 lruvec_init(node_lruvec(pgdat
));
6112 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6114 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6115 struct zone
*zone
= pgdat
->node_zones
+ j
;
6116 unsigned long size
, realsize
, freesize
, memmap_pages
;
6117 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6119 size
= zone
->spanned_pages
;
6120 realsize
= freesize
= zone
->present_pages
;
6123 * Adjust freesize so that it accounts for how much memory
6124 * is used by this zone for memmap. This affects the watermark
6125 * and per-cpu initialisations
6127 memmap_pages
= calc_memmap_size(size
, realsize
);
6128 if (!is_highmem_idx(j
)) {
6129 if (freesize
>= memmap_pages
) {
6130 freesize
-= memmap_pages
;
6133 " %s zone: %lu pages used for memmap\n",
6134 zone_names
[j
], memmap_pages
);
6136 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6137 zone_names
[j
], memmap_pages
, freesize
);
6140 /* Account for reserved pages */
6141 if (j
== 0 && freesize
> dma_reserve
) {
6142 freesize
-= dma_reserve
;
6143 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6144 zone_names
[0], dma_reserve
);
6147 if (!is_highmem_idx(j
))
6148 nr_kernel_pages
+= freesize
;
6149 /* Charge for highmem memmap if there are enough kernel pages */
6150 else if (nr_kernel_pages
> memmap_pages
* 2)
6151 nr_kernel_pages
-= memmap_pages
;
6152 nr_all_pages
+= freesize
;
6155 * Set an approximate value for lowmem here, it will be adjusted
6156 * when the bootmem allocator frees pages into the buddy system.
6157 * And all highmem pages will be managed by the buddy system.
6159 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
6163 zone
->name
= zone_names
[j
];
6164 zone
->zone_pgdat
= pgdat
;
6165 spin_lock_init(&zone
->lock
);
6166 zone_seqlock_init(zone
);
6167 zone_pcp_init(zone
);
6172 set_pageblock_order();
6173 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6174 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6175 memmap_init(size
, nid
, j
, zone_start_pfn
);
6179 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6180 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6182 unsigned long __maybe_unused start
= 0;
6183 unsigned long __maybe_unused offset
= 0;
6185 /* Skip empty nodes */
6186 if (!pgdat
->node_spanned_pages
)
6189 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6190 offset
= pgdat
->node_start_pfn
- start
;
6191 /* ia64 gets its own node_mem_map, before this, without bootmem */
6192 if (!pgdat
->node_mem_map
) {
6193 unsigned long size
, end
;
6197 * The zone's endpoints aren't required to be MAX_ORDER
6198 * aligned but the node_mem_map endpoints must be in order
6199 * for the buddy allocator to function correctly.
6201 end
= pgdat_end_pfn(pgdat
);
6202 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6203 size
= (end
- start
) * sizeof(struct page
);
6204 map
= alloc_remap(pgdat
->node_id
, size
);
6206 map
= memblock_virt_alloc_node_nopanic(size
,
6208 pgdat
->node_mem_map
= map
+ offset
;
6210 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6211 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
6212 (unsigned long)pgdat
->node_mem_map
);
6213 #ifndef CONFIG_NEED_MULTIPLE_NODES
6215 * With no DISCONTIG, the global mem_map is just set as node 0's
6217 if (pgdat
== NODE_DATA(0)) {
6218 mem_map
= NODE_DATA(0)->node_mem_map
;
6219 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6220 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6222 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6227 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
6228 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6230 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
6231 unsigned long node_start_pfn
, unsigned long *zholes_size
)
6233 pg_data_t
*pgdat
= NODE_DATA(nid
);
6234 unsigned long start_pfn
= 0;
6235 unsigned long end_pfn
= 0;
6237 /* pg_data_t should be reset to zero when it's allocated */
6238 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6240 pgdat
->node_id
= nid
;
6241 pgdat
->node_start_pfn
= node_start_pfn
;
6242 pgdat
->per_cpu_nodestats
= NULL
;
6243 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6244 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6245 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6246 (u64
)start_pfn
<< PAGE_SHIFT
,
6247 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6249 start_pfn
= node_start_pfn
;
6251 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6252 zones_size
, zholes_size
);
6254 alloc_node_mem_map(pgdat
);
6256 reset_deferred_meminit(pgdat
);
6257 free_area_init_core(pgdat
);
6260 #ifdef CONFIG_HAVE_MEMBLOCK
6262 * Only struct pages that are backed by physical memory are zeroed and
6263 * initialized by going through __init_single_page(). But, there are some
6264 * struct pages which are reserved in memblock allocator and their fields
6265 * may be accessed (for example page_to_pfn() on some configuration accesses
6266 * flags). We must explicitly zero those struct pages.
6268 void __paginginit
zero_resv_unavail(void)
6270 phys_addr_t start
, end
;
6275 * Loop through ranges that are reserved, but do not have reported
6276 * physical memory backing.
6279 for_each_resv_unavail_range(i
, &start
, &end
) {
6280 for (pfn
= PFN_DOWN(start
); pfn
< PFN_UP(end
); pfn
++) {
6281 if (!pfn_valid(ALIGN_DOWN(pfn
, pageblock_nr_pages
)))
6283 mm_zero_struct_page(pfn_to_page(pfn
));
6289 * Struct pages that do not have backing memory. This could be because
6290 * firmware is using some of this memory, or for some other reasons.
6291 * Once memblock is changed so such behaviour is not allowed: i.e.
6292 * list of "reserved" memory must be a subset of list of "memory", then
6293 * this code can be removed.
6296 pr_info("Reserved but unavailable: %lld pages", pgcnt
);
6298 #endif /* CONFIG_HAVE_MEMBLOCK */
6300 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6302 #if MAX_NUMNODES > 1
6304 * Figure out the number of possible node ids.
6306 void __init
setup_nr_node_ids(void)
6308 unsigned int highest
;
6310 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6311 nr_node_ids
= highest
+ 1;
6316 * node_map_pfn_alignment - determine the maximum internode alignment
6318 * This function should be called after node map is populated and sorted.
6319 * It calculates the maximum power of two alignment which can distinguish
6322 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6323 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6324 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6325 * shifted, 1GiB is enough and this function will indicate so.
6327 * This is used to test whether pfn -> nid mapping of the chosen memory
6328 * model has fine enough granularity to avoid incorrect mapping for the
6329 * populated node map.
6331 * Returns the determined alignment in pfn's. 0 if there is no alignment
6332 * requirement (single node).
6334 unsigned long __init
node_map_pfn_alignment(void)
6336 unsigned long accl_mask
= 0, last_end
= 0;
6337 unsigned long start
, end
, mask
;
6341 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6342 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6349 * Start with a mask granular enough to pin-point to the
6350 * start pfn and tick off bits one-by-one until it becomes
6351 * too coarse to separate the current node from the last.
6353 mask
= ~((1 << __ffs(start
)) - 1);
6354 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6357 /* accumulate all internode masks */
6361 /* convert mask to number of pages */
6362 return ~accl_mask
+ 1;
6365 /* Find the lowest pfn for a node */
6366 static unsigned long __init
find_min_pfn_for_node(int nid
)
6368 unsigned long min_pfn
= ULONG_MAX
;
6369 unsigned long start_pfn
;
6372 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6373 min_pfn
= min(min_pfn
, start_pfn
);
6375 if (min_pfn
== ULONG_MAX
) {
6376 pr_warn("Could not find start_pfn for node %d\n", nid
);
6384 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6386 * It returns the minimum PFN based on information provided via
6387 * memblock_set_node().
6389 unsigned long __init
find_min_pfn_with_active_regions(void)
6391 return find_min_pfn_for_node(MAX_NUMNODES
);
6395 * early_calculate_totalpages()
6396 * Sum pages in active regions for movable zone.
6397 * Populate N_MEMORY for calculating usable_nodes.
6399 static unsigned long __init
early_calculate_totalpages(void)
6401 unsigned long totalpages
= 0;
6402 unsigned long start_pfn
, end_pfn
;
6405 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6406 unsigned long pages
= end_pfn
- start_pfn
;
6408 totalpages
+= pages
;
6410 node_set_state(nid
, N_MEMORY
);
6416 * Find the PFN the Movable zone begins in each node. Kernel memory
6417 * is spread evenly between nodes as long as the nodes have enough
6418 * memory. When they don't, some nodes will have more kernelcore than
6421 static void __init
find_zone_movable_pfns_for_nodes(void)
6424 unsigned long usable_startpfn
;
6425 unsigned long kernelcore_node
, kernelcore_remaining
;
6426 /* save the state before borrow the nodemask */
6427 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
6428 unsigned long totalpages
= early_calculate_totalpages();
6429 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
6430 struct memblock_region
*r
;
6432 /* Need to find movable_zone earlier when movable_node is specified. */
6433 find_usable_zone_for_movable();
6436 * If movable_node is specified, ignore kernelcore and movablecore
6439 if (movable_node_is_enabled()) {
6440 for_each_memblock(memory
, r
) {
6441 if (!memblock_is_hotpluggable(r
))
6446 usable_startpfn
= PFN_DOWN(r
->base
);
6447 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6448 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6456 * If kernelcore=mirror is specified, ignore movablecore option
6458 if (mirrored_kernelcore
) {
6459 bool mem_below_4gb_not_mirrored
= false;
6461 for_each_memblock(memory
, r
) {
6462 if (memblock_is_mirror(r
))
6467 usable_startpfn
= memblock_region_memory_base_pfn(r
);
6469 if (usable_startpfn
< 0x100000) {
6470 mem_below_4gb_not_mirrored
= true;
6474 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
6475 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
6479 if (mem_below_4gb_not_mirrored
)
6480 pr_warn("This configuration results in unmirrored kernel memory.");
6486 * If movablecore=nn[KMG] was specified, calculate what size of
6487 * kernelcore that corresponds so that memory usable for
6488 * any allocation type is evenly spread. If both kernelcore
6489 * and movablecore are specified, then the value of kernelcore
6490 * will be used for required_kernelcore if it's greater than
6491 * what movablecore would have allowed.
6493 if (required_movablecore
) {
6494 unsigned long corepages
;
6497 * Round-up so that ZONE_MOVABLE is at least as large as what
6498 * was requested by the user
6500 required_movablecore
=
6501 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
6502 required_movablecore
= min(totalpages
, required_movablecore
);
6503 corepages
= totalpages
- required_movablecore
;
6505 required_kernelcore
= max(required_kernelcore
, corepages
);
6509 * If kernelcore was not specified or kernelcore size is larger
6510 * than totalpages, there is no ZONE_MOVABLE.
6512 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
6515 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6516 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
6519 /* Spread kernelcore memory as evenly as possible throughout nodes */
6520 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6521 for_each_node_state(nid
, N_MEMORY
) {
6522 unsigned long start_pfn
, end_pfn
;
6525 * Recalculate kernelcore_node if the division per node
6526 * now exceeds what is necessary to satisfy the requested
6527 * amount of memory for the kernel
6529 if (required_kernelcore
< kernelcore_node
)
6530 kernelcore_node
= required_kernelcore
/ usable_nodes
;
6533 * As the map is walked, we track how much memory is usable
6534 * by the kernel using kernelcore_remaining. When it is
6535 * 0, the rest of the node is usable by ZONE_MOVABLE
6537 kernelcore_remaining
= kernelcore_node
;
6539 /* Go through each range of PFNs within this node */
6540 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6541 unsigned long size_pages
;
6543 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
6544 if (start_pfn
>= end_pfn
)
6547 /* Account for what is only usable for kernelcore */
6548 if (start_pfn
< usable_startpfn
) {
6549 unsigned long kernel_pages
;
6550 kernel_pages
= min(end_pfn
, usable_startpfn
)
6553 kernelcore_remaining
-= min(kernel_pages
,
6554 kernelcore_remaining
);
6555 required_kernelcore
-= min(kernel_pages
,
6556 required_kernelcore
);
6558 /* Continue if range is now fully accounted */
6559 if (end_pfn
<= usable_startpfn
) {
6562 * Push zone_movable_pfn to the end so
6563 * that if we have to rebalance
6564 * kernelcore across nodes, we will
6565 * not double account here
6567 zone_movable_pfn
[nid
] = end_pfn
;
6570 start_pfn
= usable_startpfn
;
6574 * The usable PFN range for ZONE_MOVABLE is from
6575 * start_pfn->end_pfn. Calculate size_pages as the
6576 * number of pages used as kernelcore
6578 size_pages
= end_pfn
- start_pfn
;
6579 if (size_pages
> kernelcore_remaining
)
6580 size_pages
= kernelcore_remaining
;
6581 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
6584 * Some kernelcore has been met, update counts and
6585 * break if the kernelcore for this node has been
6588 required_kernelcore
-= min(required_kernelcore
,
6590 kernelcore_remaining
-= size_pages
;
6591 if (!kernelcore_remaining
)
6597 * If there is still required_kernelcore, we do another pass with one
6598 * less node in the count. This will push zone_movable_pfn[nid] further
6599 * along on the nodes that still have memory until kernelcore is
6603 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
6607 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6608 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
6609 zone_movable_pfn
[nid
] =
6610 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
6613 /* restore the node_state */
6614 node_states
[N_MEMORY
] = saved_node_state
;
6617 /* Any regular or high memory on that node ? */
6618 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
6620 enum zone_type zone_type
;
6622 if (N_MEMORY
== N_NORMAL_MEMORY
)
6625 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
6626 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
6627 if (populated_zone(zone
)) {
6628 node_set_state(nid
, N_HIGH_MEMORY
);
6629 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
6630 zone_type
<= ZONE_NORMAL
)
6631 node_set_state(nid
, N_NORMAL_MEMORY
);
6638 * free_area_init_nodes - Initialise all pg_data_t and zone data
6639 * @max_zone_pfn: an array of max PFNs for each zone
6641 * This will call free_area_init_node() for each active node in the system.
6642 * Using the page ranges provided by memblock_set_node(), the size of each
6643 * zone in each node and their holes is calculated. If the maximum PFN
6644 * between two adjacent zones match, it is assumed that the zone is empty.
6645 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6646 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6647 * starts where the previous one ended. For example, ZONE_DMA32 starts
6648 * at arch_max_dma_pfn.
6650 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
6652 unsigned long start_pfn
, end_pfn
;
6655 /* Record where the zone boundaries are */
6656 memset(arch_zone_lowest_possible_pfn
, 0,
6657 sizeof(arch_zone_lowest_possible_pfn
));
6658 memset(arch_zone_highest_possible_pfn
, 0,
6659 sizeof(arch_zone_highest_possible_pfn
));
6661 start_pfn
= find_min_pfn_with_active_regions();
6663 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6664 if (i
== ZONE_MOVABLE
)
6667 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
6668 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
6669 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
6671 start_pfn
= end_pfn
;
6674 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6675 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6676 find_zone_movable_pfns_for_nodes();
6678 /* Print out the zone ranges */
6679 pr_info("Zone ranges:\n");
6680 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6681 if (i
== ZONE_MOVABLE
)
6683 pr_info(" %-8s ", zone_names
[i
]);
6684 if (arch_zone_lowest_possible_pfn
[i
] ==
6685 arch_zone_highest_possible_pfn
[i
])
6688 pr_cont("[mem %#018Lx-%#018Lx]\n",
6689 (u64
)arch_zone_lowest_possible_pfn
[i
]
6691 ((u64
)arch_zone_highest_possible_pfn
[i
]
6692 << PAGE_SHIFT
) - 1);
6695 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6696 pr_info("Movable zone start for each node\n");
6697 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6698 if (zone_movable_pfn
[i
])
6699 pr_info(" Node %d: %#018Lx\n", i
,
6700 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6703 /* Print out the early node map */
6704 pr_info("Early memory node ranges\n");
6705 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6706 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6707 (u64
)start_pfn
<< PAGE_SHIFT
,
6708 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6710 /* Initialise every node */
6711 mminit_verify_pageflags_layout();
6712 setup_nr_node_ids();
6713 for_each_online_node(nid
) {
6714 pg_data_t
*pgdat
= NODE_DATA(nid
);
6715 free_area_init_node(nid
, NULL
,
6716 find_min_pfn_for_node(nid
), NULL
);
6718 /* Any memory on that node */
6719 if (pgdat
->node_present_pages
)
6720 node_set_state(nid
, N_MEMORY
);
6721 check_for_memory(pgdat
, nid
);
6723 zero_resv_unavail();
6726 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6728 unsigned long long coremem
;
6732 coremem
= memparse(p
, &p
);
6733 *core
= coremem
>> PAGE_SHIFT
;
6735 /* Paranoid check that UL is enough for the coremem value */
6736 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6742 * kernelcore=size sets the amount of memory for use for allocations that
6743 * cannot be reclaimed or migrated.
6745 static int __init
cmdline_parse_kernelcore(char *p
)
6747 /* parse kernelcore=mirror */
6748 if (parse_option_str(p
, "mirror")) {
6749 mirrored_kernelcore
= true;
6753 return cmdline_parse_core(p
, &required_kernelcore
);
6757 * movablecore=size sets the amount of memory for use for allocations that
6758 * can be reclaimed or migrated.
6760 static int __init
cmdline_parse_movablecore(char *p
)
6762 return cmdline_parse_core(p
, &required_movablecore
);
6765 early_param("kernelcore", cmdline_parse_kernelcore
);
6766 early_param("movablecore", cmdline_parse_movablecore
);
6768 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6770 void adjust_managed_page_count(struct page
*page
, long count
)
6772 spin_lock(&managed_page_count_lock
);
6773 page_zone(page
)->managed_pages
+= count
;
6774 totalram_pages
+= count
;
6775 #ifdef CONFIG_HIGHMEM
6776 if (PageHighMem(page
))
6777 totalhigh_pages
+= count
;
6779 spin_unlock(&managed_page_count_lock
);
6781 EXPORT_SYMBOL(adjust_managed_page_count
);
6783 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6786 unsigned long pages
= 0;
6788 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6789 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6790 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6791 if ((unsigned int)poison
<= 0xFF)
6792 memset(pos
, poison
, PAGE_SIZE
);
6793 free_reserved_page(virt_to_page(pos
));
6797 pr_info("Freeing %s memory: %ldK\n",
6798 s
, pages
<< (PAGE_SHIFT
- 10));
6802 EXPORT_SYMBOL(free_reserved_area
);
6804 #ifdef CONFIG_HIGHMEM
6805 void free_highmem_page(struct page
*page
)
6807 __free_reserved_page(page
);
6809 page_zone(page
)->managed_pages
++;
6815 void __init
mem_init_print_info(const char *str
)
6817 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6818 unsigned long init_code_size
, init_data_size
;
6820 physpages
= get_num_physpages();
6821 codesize
= _etext
- _stext
;
6822 datasize
= _edata
- _sdata
;
6823 rosize
= __end_rodata
- __start_rodata
;
6824 bss_size
= __bss_stop
- __bss_start
;
6825 init_data_size
= __init_end
- __init_begin
;
6826 init_code_size
= _einittext
- _sinittext
;
6829 * Detect special cases and adjust section sizes accordingly:
6830 * 1) .init.* may be embedded into .data sections
6831 * 2) .init.text.* may be out of [__init_begin, __init_end],
6832 * please refer to arch/tile/kernel/vmlinux.lds.S.
6833 * 3) .rodata.* may be embedded into .text or .data sections.
6835 #define adj_init_size(start, end, size, pos, adj) \
6837 if (start <= pos && pos < end && size > adj) \
6841 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6842 _sinittext
, init_code_size
);
6843 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6844 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6845 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6846 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6848 #undef adj_init_size
6850 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6851 #ifdef CONFIG_HIGHMEM
6855 nr_free_pages() << (PAGE_SHIFT
- 10),
6856 physpages
<< (PAGE_SHIFT
- 10),
6857 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6858 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6859 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6860 totalcma_pages
<< (PAGE_SHIFT
- 10),
6861 #ifdef CONFIG_HIGHMEM
6862 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6864 str
? ", " : "", str
? str
: "");
6868 * set_dma_reserve - set the specified number of pages reserved in the first zone
6869 * @new_dma_reserve: The number of pages to mark reserved
6871 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6872 * In the DMA zone, a significant percentage may be consumed by kernel image
6873 * and other unfreeable allocations which can skew the watermarks badly. This
6874 * function may optionally be used to account for unfreeable pages in the
6875 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6876 * smaller per-cpu batchsize.
6878 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6880 dma_reserve
= new_dma_reserve
;
6883 void __init
free_area_init(unsigned long *zones_size
)
6885 free_area_init_node(0, zones_size
,
6886 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6887 zero_resv_unavail();
6890 static int page_alloc_cpu_dead(unsigned int cpu
)
6893 lru_add_drain_cpu(cpu
);
6897 * Spill the event counters of the dead processor
6898 * into the current processors event counters.
6899 * This artificially elevates the count of the current
6902 vm_events_fold_cpu(cpu
);
6905 * Zero the differential counters of the dead processor
6906 * so that the vm statistics are consistent.
6908 * This is only okay since the processor is dead and cannot
6909 * race with what we are doing.
6911 cpu_vm_stats_fold(cpu
);
6915 void __init
page_alloc_init(void)
6919 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
6920 "mm/page_alloc:dead", NULL
,
6921 page_alloc_cpu_dead
);
6926 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6927 * or min_free_kbytes changes.
6929 static void calculate_totalreserve_pages(void)
6931 struct pglist_data
*pgdat
;
6932 unsigned long reserve_pages
= 0;
6933 enum zone_type i
, j
;
6935 for_each_online_pgdat(pgdat
) {
6937 pgdat
->totalreserve_pages
= 0;
6939 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6940 struct zone
*zone
= pgdat
->node_zones
+ i
;
6943 /* Find valid and maximum lowmem_reserve in the zone */
6944 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6945 if (zone
->lowmem_reserve
[j
] > max
)
6946 max
= zone
->lowmem_reserve
[j
];
6949 /* we treat the high watermark as reserved pages. */
6950 max
+= high_wmark_pages(zone
);
6952 if (max
> zone
->managed_pages
)
6953 max
= zone
->managed_pages
;
6955 pgdat
->totalreserve_pages
+= max
;
6957 reserve_pages
+= max
;
6960 totalreserve_pages
= reserve_pages
;
6964 * setup_per_zone_lowmem_reserve - called whenever
6965 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6966 * has a correct pages reserved value, so an adequate number of
6967 * pages are left in the zone after a successful __alloc_pages().
6969 static void setup_per_zone_lowmem_reserve(void)
6971 struct pglist_data
*pgdat
;
6972 enum zone_type j
, idx
;
6974 for_each_online_pgdat(pgdat
) {
6975 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6976 struct zone
*zone
= pgdat
->node_zones
+ j
;
6977 unsigned long managed_pages
= zone
->managed_pages
;
6979 zone
->lowmem_reserve
[j
] = 0;
6983 struct zone
*lower_zone
;
6987 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6988 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6990 lower_zone
= pgdat
->node_zones
+ idx
;
6991 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6992 sysctl_lowmem_reserve_ratio
[idx
];
6993 managed_pages
+= lower_zone
->managed_pages
;
6998 /* update totalreserve_pages */
6999 calculate_totalreserve_pages();
7002 static void __setup_per_zone_wmarks(void)
7004 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
7005 unsigned long lowmem_pages
= 0;
7007 unsigned long flags
;
7009 /* Calculate total number of !ZONE_HIGHMEM pages */
7010 for_each_zone(zone
) {
7011 if (!is_highmem(zone
))
7012 lowmem_pages
+= zone
->managed_pages
;
7015 for_each_zone(zone
) {
7018 spin_lock_irqsave(&zone
->lock
, flags
);
7019 tmp
= (u64
)pages_min
* zone
->managed_pages
;
7020 do_div(tmp
, lowmem_pages
);
7021 if (is_highmem(zone
)) {
7023 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7024 * need highmem pages, so cap pages_min to a small
7027 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7028 * deltas control asynch page reclaim, and so should
7029 * not be capped for highmem.
7031 unsigned long min_pages
;
7033 min_pages
= zone
->managed_pages
/ 1024;
7034 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7035 zone
->watermark
[WMARK_MIN
] = min_pages
;
7038 * If it's a lowmem zone, reserve a number of pages
7039 * proportionate to the zone's size.
7041 zone
->watermark
[WMARK_MIN
] = tmp
;
7045 * Set the kswapd watermarks distance according to the
7046 * scale factor in proportion to available memory, but
7047 * ensure a minimum size on small systems.
7049 tmp
= max_t(u64
, tmp
>> 2,
7050 mult_frac(zone
->managed_pages
,
7051 watermark_scale_factor
, 10000));
7053 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7054 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7056 spin_unlock_irqrestore(&zone
->lock
, flags
);
7059 /* update totalreserve_pages */
7060 calculate_totalreserve_pages();
7064 * setup_per_zone_wmarks - called when min_free_kbytes changes
7065 * or when memory is hot-{added|removed}
7067 * Ensures that the watermark[min,low,high] values for each zone are set
7068 * correctly with respect to min_free_kbytes.
7070 void setup_per_zone_wmarks(void)
7072 static DEFINE_SPINLOCK(lock
);
7075 __setup_per_zone_wmarks();
7080 * Initialise min_free_kbytes.
7082 * For small machines we want it small (128k min). For large machines
7083 * we want it large (64MB max). But it is not linear, because network
7084 * bandwidth does not increase linearly with machine size. We use
7086 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7087 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7103 int __meminit
init_per_zone_wmark_min(void)
7105 unsigned long lowmem_kbytes
;
7106 int new_min_free_kbytes
;
7108 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7109 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7111 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7112 min_free_kbytes
= new_min_free_kbytes
;
7113 if (min_free_kbytes
< 128)
7114 min_free_kbytes
= 128;
7115 if (min_free_kbytes
> 65536)
7116 min_free_kbytes
= 65536;
7118 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7119 new_min_free_kbytes
, user_min_free_kbytes
);
7121 setup_per_zone_wmarks();
7122 refresh_zone_stat_thresholds();
7123 setup_per_zone_lowmem_reserve();
7126 setup_min_unmapped_ratio();
7127 setup_min_slab_ratio();
7132 core_initcall(init_per_zone_wmark_min
)
7135 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7136 * that we can call two helper functions whenever min_free_kbytes
7139 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7140 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7144 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7149 user_min_free_kbytes
= min_free_kbytes
;
7150 setup_per_zone_wmarks();
7155 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7156 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7160 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7165 setup_per_zone_wmarks();
7171 static void setup_min_unmapped_ratio(void)
7176 for_each_online_pgdat(pgdat
)
7177 pgdat
->min_unmapped_pages
= 0;
7180 zone
->zone_pgdat
->min_unmapped_pages
+= (zone
->managed_pages
*
7181 sysctl_min_unmapped_ratio
) / 100;
7185 int sysctl_min_unmapped_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_unmapped_ratio();
7199 static void setup_min_slab_ratio(void)
7204 for_each_online_pgdat(pgdat
)
7205 pgdat
->min_slab_pages
= 0;
7208 zone
->zone_pgdat
->min_slab_pages
+= (zone
->managed_pages
*
7209 sysctl_min_slab_ratio
) / 100;
7212 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7213 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7217 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7221 setup_min_slab_ratio();
7228 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7229 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7230 * whenever sysctl_lowmem_reserve_ratio changes.
7232 * The reserve ratio obviously has absolutely no relation with the
7233 * minimum watermarks. The lowmem reserve ratio can only make sense
7234 * if in function of the boot time zone sizes.
7236 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7237 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7239 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7240 setup_per_zone_lowmem_reserve();
7245 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7246 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7247 * pagelist can have before it gets flushed back to buddy allocator.
7249 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7250 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7253 int old_percpu_pagelist_fraction
;
7256 mutex_lock(&pcp_batch_high_lock
);
7257 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7259 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7260 if (!write
|| ret
< 0)
7263 /* Sanity checking to avoid pcp imbalance */
7264 if (percpu_pagelist_fraction
&&
7265 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7266 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7272 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7275 for_each_populated_zone(zone
) {
7278 for_each_possible_cpu(cpu
)
7279 pageset_set_high_and_batch(zone
,
7280 per_cpu_ptr(zone
->pageset
, cpu
));
7283 mutex_unlock(&pcp_batch_high_lock
);
7288 int hashdist
= HASHDIST_DEFAULT
;
7290 static int __init
set_hashdist(char *str
)
7294 hashdist
= simple_strtoul(str
, &str
, 0);
7297 __setup("hashdist=", set_hashdist
);
7300 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7302 * Returns the number of pages that arch has reserved but
7303 * is not known to alloc_large_system_hash().
7305 static unsigned long __init
arch_reserved_kernel_pages(void)
7312 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7313 * machines. As memory size is increased the scale is also increased but at
7314 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7315 * quadruples the scale is increased by one, which means the size of hash table
7316 * only doubles, instead of quadrupling as well.
7317 * Because 32-bit systems cannot have large physical memory, where this scaling
7318 * makes sense, it is disabled on such platforms.
7320 #if __BITS_PER_LONG > 32
7321 #define ADAPT_SCALE_BASE (64ul << 30)
7322 #define ADAPT_SCALE_SHIFT 2
7323 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7327 * allocate a large system hash table from bootmem
7328 * - it is assumed that the hash table must contain an exact power-of-2
7329 * quantity of entries
7330 * - limit is the number of hash buckets, not the total allocation size
7332 void *__init
alloc_large_system_hash(const char *tablename
,
7333 unsigned long bucketsize
,
7334 unsigned long numentries
,
7337 unsigned int *_hash_shift
,
7338 unsigned int *_hash_mask
,
7339 unsigned long low_limit
,
7340 unsigned long high_limit
)
7342 unsigned long long max
= high_limit
;
7343 unsigned long log2qty
, size
;
7347 /* allow the kernel cmdline to have a say */
7349 /* round applicable memory size up to nearest megabyte */
7350 numentries
= nr_kernel_pages
;
7351 numentries
-= arch_reserved_kernel_pages();
7353 /* It isn't necessary when PAGE_SIZE >= 1MB */
7354 if (PAGE_SHIFT
< 20)
7355 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7357 #if __BITS_PER_LONG > 32
7359 unsigned long adapt
;
7361 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
7362 adapt
<<= ADAPT_SCALE_SHIFT
)
7367 /* limit to 1 bucket per 2^scale bytes of low memory */
7368 if (scale
> PAGE_SHIFT
)
7369 numentries
>>= (scale
- PAGE_SHIFT
);
7371 numentries
<<= (PAGE_SHIFT
- scale
);
7373 /* Make sure we've got at least a 0-order allocation.. */
7374 if (unlikely(flags
& HASH_SMALL
)) {
7375 /* Makes no sense without HASH_EARLY */
7376 WARN_ON(!(flags
& HASH_EARLY
));
7377 if (!(numentries
>> *_hash_shift
)) {
7378 numentries
= 1UL << *_hash_shift
;
7379 BUG_ON(!numentries
);
7381 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
7382 numentries
= PAGE_SIZE
/ bucketsize
;
7384 numentries
= roundup_pow_of_two(numentries
);
7386 /* limit allocation size to 1/16 total memory by default */
7388 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
7389 do_div(max
, bucketsize
);
7391 max
= min(max
, 0x80000000ULL
);
7393 if (numentries
< low_limit
)
7394 numentries
= low_limit
;
7395 if (numentries
> max
)
7398 log2qty
= ilog2(numentries
);
7400 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
7402 size
= bucketsize
<< log2qty
;
7403 if (flags
& HASH_EARLY
) {
7404 if (flags
& HASH_ZERO
)
7405 table
= memblock_virt_alloc_nopanic(size
, 0);
7407 table
= memblock_virt_alloc_raw(size
, 0);
7408 } else if (hashdist
) {
7409 table
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
7412 * If bucketsize is not a power-of-two, we may free
7413 * some pages at the end of hash table which
7414 * alloc_pages_exact() automatically does
7416 if (get_order(size
) < MAX_ORDER
) {
7417 table
= alloc_pages_exact(size
, gfp_flags
);
7418 kmemleak_alloc(table
, size
, 1, gfp_flags
);
7421 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
7424 panic("Failed to allocate %s hash table\n", tablename
);
7426 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
7427 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
7430 *_hash_shift
= log2qty
;
7432 *_hash_mask
= (1 << log2qty
) - 1;
7438 * This function checks whether pageblock includes unmovable pages or not.
7439 * If @count is not zero, it is okay to include less @count unmovable pages
7441 * PageLRU check without isolation or lru_lock could race so that
7442 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
7443 * check without lock_page also may miss some movable non-lru pages at
7444 * race condition. So you can't expect this function should be exact.
7446 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
7448 bool skip_hwpoisoned_pages
)
7450 unsigned long pfn
, iter
, found
;
7453 * For avoiding noise data, lru_add_drain_all() should be called
7454 * If ZONE_MOVABLE, the zone never contains unmovable pages
7456 if (zone_idx(zone
) == ZONE_MOVABLE
)
7460 * CMA allocations (alloc_contig_range) really need to mark isolate
7461 * CMA pageblocks even when they are not movable in fact so consider
7462 * them movable here.
7464 if (is_migrate_cma(migratetype
) &&
7465 is_migrate_cma(get_pageblock_migratetype(page
)))
7468 pfn
= page_to_pfn(page
);
7469 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
7470 unsigned long check
= pfn
+ iter
;
7472 if (!pfn_valid_within(check
))
7475 page
= pfn_to_page(check
);
7477 if (PageReserved(page
))
7481 * Hugepages are not in LRU lists, but they're movable.
7482 * We need not scan over tail pages bacause we don't
7483 * handle each tail page individually in migration.
7485 if (PageHuge(page
)) {
7486 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
7491 * We can't use page_count without pin a page
7492 * because another CPU can free compound page.
7493 * This check already skips compound tails of THP
7494 * because their page->_refcount is zero at all time.
7496 if (!page_ref_count(page
)) {
7497 if (PageBuddy(page
))
7498 iter
+= (1 << page_order(page
)) - 1;
7503 * The HWPoisoned page may be not in buddy system, and
7504 * page_count() is not 0.
7506 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
7509 if (__PageMovable(page
))
7515 * If there are RECLAIMABLE pages, we need to check
7516 * it. But now, memory offline itself doesn't call
7517 * shrink_node_slabs() and it still to be fixed.
7520 * If the page is not RAM, page_count()should be 0.
7521 * we don't need more check. This is an _used_ not-movable page.
7523 * The problematic thing here is PG_reserved pages. PG_reserved
7524 * is set to both of a memory hole page and a _used_ kernel
7533 bool is_pageblock_removable_nolock(struct page
*page
)
7539 * We have to be careful here because we are iterating over memory
7540 * sections which are not zone aware so we might end up outside of
7541 * the zone but still within the section.
7542 * We have to take care about the node as well. If the node is offline
7543 * its NODE_DATA will be NULL - see page_zone.
7545 if (!node_online(page_to_nid(page
)))
7548 zone
= page_zone(page
);
7549 pfn
= page_to_pfn(page
);
7550 if (!zone_spans_pfn(zone
, pfn
))
7553 return !has_unmovable_pages(zone
, page
, 0, MIGRATE_MOVABLE
, true);
7556 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7558 static unsigned long pfn_max_align_down(unsigned long pfn
)
7560 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7561 pageblock_nr_pages
) - 1);
7564 static unsigned long pfn_max_align_up(unsigned long pfn
)
7566 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
7567 pageblock_nr_pages
));
7570 /* [start, end) must belong to a single zone. */
7571 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
7572 unsigned long start
, unsigned long end
)
7574 /* This function is based on compact_zone() from compaction.c. */
7575 unsigned long nr_reclaimed
;
7576 unsigned long pfn
= start
;
7577 unsigned int tries
= 0;
7582 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
7583 if (fatal_signal_pending(current
)) {
7588 if (list_empty(&cc
->migratepages
)) {
7589 cc
->nr_migratepages
= 0;
7590 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
7596 } else if (++tries
== 5) {
7597 ret
= ret
< 0 ? ret
: -EBUSY
;
7601 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
7603 cc
->nr_migratepages
-= nr_reclaimed
;
7605 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
7606 NULL
, 0, cc
->mode
, MR_CMA
);
7609 putback_movable_pages(&cc
->migratepages
);
7616 * alloc_contig_range() -- tries to allocate given range of pages
7617 * @start: start PFN to allocate
7618 * @end: one-past-the-last PFN to allocate
7619 * @migratetype: migratetype of the underlaying pageblocks (either
7620 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7621 * in range must have the same migratetype and it must
7622 * be either of the two.
7623 * @gfp_mask: GFP mask to use during compaction
7625 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7626 * aligned, however it's the caller's responsibility to guarantee that
7627 * we are the only thread that changes migrate type of pageblocks the
7630 * The PFN range must belong to a single zone.
7632 * Returns zero on success or negative error code. On success all
7633 * pages which PFN is in [start, end) are allocated for the caller and
7634 * need to be freed with free_contig_range().
7636 int alloc_contig_range(unsigned long start
, unsigned long end
,
7637 unsigned migratetype
, gfp_t gfp_mask
)
7639 unsigned long outer_start
, outer_end
;
7643 struct compact_control cc
= {
7644 .nr_migratepages
= 0,
7646 .zone
= page_zone(pfn_to_page(start
)),
7647 .mode
= MIGRATE_SYNC
,
7648 .ignore_skip_hint
= true,
7649 .no_set_skip_hint
= true,
7650 .gfp_mask
= current_gfp_context(gfp_mask
),
7652 INIT_LIST_HEAD(&cc
.migratepages
);
7655 * What we do here is we mark all pageblocks in range as
7656 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7657 * have different sizes, and due to the way page allocator
7658 * work, we align the range to biggest of the two pages so
7659 * that page allocator won't try to merge buddies from
7660 * different pageblocks and change MIGRATE_ISOLATE to some
7661 * other migration type.
7663 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7664 * migrate the pages from an unaligned range (ie. pages that
7665 * we are interested in). This will put all the pages in
7666 * range back to page allocator as MIGRATE_ISOLATE.
7668 * When this is done, we take the pages in range from page
7669 * allocator removing them from the buddy system. This way
7670 * page allocator will never consider using them.
7672 * This lets us mark the pageblocks back as
7673 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7674 * aligned range but not in the unaligned, original range are
7675 * put back to page allocator so that buddy can use them.
7678 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7679 pfn_max_align_up(end
), migratetype
,
7685 * In case of -EBUSY, we'd like to know which page causes problem.
7686 * So, just fall through. test_pages_isolated() has a tracepoint
7687 * which will report the busy page.
7689 * It is possible that busy pages could become available before
7690 * the call to test_pages_isolated, and the range will actually be
7691 * allocated. So, if we fall through be sure to clear ret so that
7692 * -EBUSY is not accidentally used or returned to caller.
7694 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7695 if (ret
&& ret
!= -EBUSY
)
7700 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7701 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7702 * more, all pages in [start, end) are free in page allocator.
7703 * What we are going to do is to allocate all pages from
7704 * [start, end) (that is remove them from page allocator).
7706 * The only problem is that pages at the beginning and at the
7707 * end of interesting range may be not aligned with pages that
7708 * page allocator holds, ie. they can be part of higher order
7709 * pages. Because of this, we reserve the bigger range and
7710 * once this is done free the pages we are not interested in.
7712 * We don't have to hold zone->lock here because the pages are
7713 * isolated thus they won't get removed from buddy.
7716 lru_add_drain_all();
7717 drain_all_pages(cc
.zone
);
7720 outer_start
= start
;
7721 while (!PageBuddy(pfn_to_page(outer_start
))) {
7722 if (++order
>= MAX_ORDER
) {
7723 outer_start
= start
;
7726 outer_start
&= ~0UL << order
;
7729 if (outer_start
!= start
) {
7730 order
= page_order(pfn_to_page(outer_start
));
7733 * outer_start page could be small order buddy page and
7734 * it doesn't include start page. Adjust outer_start
7735 * in this case to report failed page properly
7736 * on tracepoint in test_pages_isolated()
7738 if (outer_start
+ (1UL << order
) <= start
)
7739 outer_start
= start
;
7742 /* Make sure the range is really isolated. */
7743 if (test_pages_isolated(outer_start
, end
, false)) {
7744 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
7745 __func__
, outer_start
, end
);
7750 /* Grab isolated pages from freelists. */
7751 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7757 /* Free head and tail (if any) */
7758 if (start
!= outer_start
)
7759 free_contig_range(outer_start
, start
- outer_start
);
7760 if (end
!= outer_end
)
7761 free_contig_range(end
, outer_end
- end
);
7764 undo_isolate_page_range(pfn_max_align_down(start
),
7765 pfn_max_align_up(end
), migratetype
);
7769 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7771 unsigned int count
= 0;
7773 for (; nr_pages
--; pfn
++) {
7774 struct page
*page
= pfn_to_page(pfn
);
7776 count
+= page_count(page
) != 1;
7779 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7783 #ifdef CONFIG_MEMORY_HOTPLUG
7785 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7786 * page high values need to be recalulated.
7788 void __meminit
zone_pcp_update(struct zone
*zone
)
7791 mutex_lock(&pcp_batch_high_lock
);
7792 for_each_possible_cpu(cpu
)
7793 pageset_set_high_and_batch(zone
,
7794 per_cpu_ptr(zone
->pageset
, cpu
));
7795 mutex_unlock(&pcp_batch_high_lock
);
7799 void zone_pcp_reset(struct zone
*zone
)
7801 unsigned long flags
;
7803 struct per_cpu_pageset
*pset
;
7805 /* avoid races with drain_pages() */
7806 local_irq_save(flags
);
7807 if (zone
->pageset
!= &boot_pageset
) {
7808 for_each_online_cpu(cpu
) {
7809 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7810 drain_zonestat(zone
, pset
);
7812 free_percpu(zone
->pageset
);
7813 zone
->pageset
= &boot_pageset
;
7815 local_irq_restore(flags
);
7818 #ifdef CONFIG_MEMORY_HOTREMOVE
7820 * All pages in the range must be in a single zone and isolated
7821 * before calling this.
7824 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7828 unsigned int order
, i
;
7830 unsigned long flags
;
7831 /* find the first valid pfn */
7832 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7837 offline_mem_sections(pfn
, end_pfn
);
7838 zone
= page_zone(pfn_to_page(pfn
));
7839 spin_lock_irqsave(&zone
->lock
, flags
);
7841 while (pfn
< end_pfn
) {
7842 if (!pfn_valid(pfn
)) {
7846 page
= pfn_to_page(pfn
);
7848 * The HWPoisoned page may be not in buddy system, and
7849 * page_count() is not 0.
7851 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7853 SetPageReserved(page
);
7857 BUG_ON(page_count(page
));
7858 BUG_ON(!PageBuddy(page
));
7859 order
= page_order(page
);
7860 #ifdef CONFIG_DEBUG_VM
7861 pr_info("remove from free list %lx %d %lx\n",
7862 pfn
, 1 << order
, end_pfn
);
7864 list_del(&page
->lru
);
7865 rmv_page_order(page
);
7866 zone
->free_area
[order
].nr_free
--;
7867 for (i
= 0; i
< (1 << order
); i
++)
7868 SetPageReserved((page
+i
));
7869 pfn
+= (1 << order
);
7871 spin_unlock_irqrestore(&zone
->lock
, flags
);
7875 bool is_free_buddy_page(struct page
*page
)
7877 struct zone
*zone
= page_zone(page
);
7878 unsigned long pfn
= page_to_pfn(page
);
7879 unsigned long flags
;
7882 spin_lock_irqsave(&zone
->lock
, flags
);
7883 for (order
= 0; order
< MAX_ORDER
; order
++) {
7884 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7886 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7889 spin_unlock_irqrestore(&zone
->lock
, flags
);
7891 return order
< MAX_ORDER
;