1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/mm/page_alloc.c
5 * Manages the free list, the system allocates free pages here.
6 * Note that kmalloc() lives in slab.c
8 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
9 * Swap reorganised 29.12.95, Stephen Tweedie
10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
11 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
12 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
13 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
14 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
15 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
18 #include <linux/stddef.h>
20 #include <linux/highmem.h>
21 #include <linux/swap.h>
22 #include <linux/interrupt.h>
23 #include <linux/pagemap.h>
24 #include <linux/jiffies.h>
25 #include <linux/memblock.h>
26 #include <linux/compiler.h>
27 #include <linux/kernel.h>
28 #include <linux/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/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/random.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <trace/events/oom.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/mmu_notifier.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>
71 #include <linux/psi.h>
72 #include <linux/padata.h>
73 #include <linux/khugepaged.h>
74 #include <linux/buffer_head.h>
75 #include <asm/sections.h>
76 #include <asm/tlbflush.h>
77 #include <asm/div64.h>
80 #include "page_reporting.h"
82 /* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
83 typedef int __bitwise fpi_t
;
85 /* No special request */
86 #define FPI_NONE ((__force fpi_t)0)
89 * Skip free page reporting notification for the (possibly merged) page.
90 * This does not hinder free page reporting from grabbing the page,
91 * reporting it and marking it "reported" - it only skips notifying
92 * the free page reporting infrastructure about a newly freed page. For
93 * example, used when temporarily pulling a page from a freelist and
94 * putting it back unmodified.
96 #define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0))
99 * Place the (possibly merged) page to the tail of the freelist. Will ignore
100 * page shuffling (relevant code - e.g., memory onlining - is expected to
101 * shuffle the whole zone).
103 * Note: No code should rely on this flag for correctness - it's purely
104 * to allow for optimizations when handing back either fresh pages
105 * (memory onlining) or untouched pages (page isolation, free page
108 #define FPI_TO_TAIL ((__force fpi_t)BIT(1))
111 * Don't poison memory with KASAN (only for the tag-based modes).
112 * During boot, all non-reserved memblock memory is exposed to page_alloc.
113 * Poisoning all that memory lengthens boot time, especially on systems with
114 * large amount of RAM. This flag is used to skip that poisoning.
115 * This is only done for the tag-based KASAN modes, as those are able to
116 * detect memory corruptions with the memory tags assigned by default.
117 * All memory allocated normally after boot gets poisoned as usual.
119 #define FPI_SKIP_KASAN_POISON ((__force fpi_t)BIT(2))
121 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
122 static DEFINE_MUTEX(pcp_batch_high_lock
);
123 #define MIN_PERCPU_PAGELIST_FRACTION (8)
125 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
126 DEFINE_PER_CPU(int, numa_node
);
127 EXPORT_PER_CPU_SYMBOL(numa_node
);
130 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
132 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
134 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
135 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
136 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
137 * defined in <linux/topology.h>.
139 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
140 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
143 /* work_structs for global per-cpu drains */
146 struct work_struct work
;
148 static DEFINE_MUTEX(pcpu_drain_mutex
);
149 static DEFINE_PER_CPU(struct pcpu_drain
, pcpu_drain
);
151 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
152 volatile unsigned long latent_entropy __latent_entropy
;
153 EXPORT_SYMBOL(latent_entropy
);
157 * Array of node states.
159 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
160 [N_POSSIBLE
] = NODE_MASK_ALL
,
161 [N_ONLINE
] = { { [0] = 1UL } },
163 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
164 #ifdef CONFIG_HIGHMEM
165 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
167 [N_MEMORY
] = { { [0] = 1UL } },
168 [N_CPU
] = { { [0] = 1UL } },
171 EXPORT_SYMBOL(node_states
);
173 atomic_long_t _totalram_pages __read_mostly
;
174 EXPORT_SYMBOL(_totalram_pages
);
175 unsigned long totalreserve_pages __read_mostly
;
176 unsigned long totalcma_pages __read_mostly
;
178 int percpu_pagelist_fraction
;
179 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
180 DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON
, init_on_alloc
);
181 EXPORT_SYMBOL(init_on_alloc
);
183 DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON
, init_on_free
);
184 EXPORT_SYMBOL(init_on_free
);
186 static bool _init_on_alloc_enabled_early __read_mostly
187 = IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON
);
188 static int __init
early_init_on_alloc(char *buf
)
191 return kstrtobool(buf
, &_init_on_alloc_enabled_early
);
193 early_param("init_on_alloc", early_init_on_alloc
);
195 static bool _init_on_free_enabled_early __read_mostly
196 = IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON
);
197 static int __init
early_init_on_free(char *buf
)
199 return kstrtobool(buf
, &_init_on_free_enabled_early
);
201 early_param("init_on_free", early_init_on_free
);
204 * A cached value of the page's pageblock's migratetype, used when the page is
205 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
206 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
207 * Also the migratetype set in the page does not necessarily match the pcplist
208 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
209 * other index - this ensures that it will be put on the correct CMA freelist.
211 static inline int get_pcppage_migratetype(struct page
*page
)
216 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
218 page
->index
= migratetype
;
221 #ifdef CONFIG_PM_SLEEP
223 * The following functions are used by the suspend/hibernate code to temporarily
224 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
225 * while devices are suspended. To avoid races with the suspend/hibernate code,
226 * they should always be called with system_transition_mutex held
227 * (gfp_allowed_mask also should only be modified with system_transition_mutex
228 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
229 * with that modification).
232 static gfp_t saved_gfp_mask
;
234 void pm_restore_gfp_mask(void)
236 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
237 if (saved_gfp_mask
) {
238 gfp_allowed_mask
= saved_gfp_mask
;
243 void pm_restrict_gfp_mask(void)
245 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
246 WARN_ON(saved_gfp_mask
);
247 saved_gfp_mask
= gfp_allowed_mask
;
248 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
251 bool pm_suspended_storage(void)
253 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
257 #endif /* CONFIG_PM_SLEEP */
259 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
260 unsigned int pageblock_order __read_mostly
;
263 static void __free_pages_ok(struct page
*page
, unsigned int order
,
267 * results with 256, 32 in the lowmem_reserve sysctl:
268 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
269 * 1G machine -> (16M dma, 784M normal, 224M high)
270 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
271 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
272 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
274 * TBD: should special case ZONE_DMA32 machines here - in those we normally
275 * don't need any ZONE_NORMAL reservation
277 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
] = {
278 #ifdef CONFIG_ZONE_DMA
281 #ifdef CONFIG_ZONE_DMA32
285 #ifdef CONFIG_HIGHMEM
291 static char * const zone_names
[MAX_NR_ZONES
] = {
292 #ifdef CONFIG_ZONE_DMA
295 #ifdef CONFIG_ZONE_DMA32
299 #ifdef CONFIG_HIGHMEM
303 #ifdef CONFIG_ZONE_DEVICE
308 const char * const migratetype_names
[MIGRATE_TYPES
] = {
316 #ifdef CONFIG_MEMORY_ISOLATION
321 compound_page_dtor
* const compound_page_dtors
[NR_COMPOUND_DTORS
] = {
322 [NULL_COMPOUND_DTOR
] = NULL
,
323 [COMPOUND_PAGE_DTOR
] = free_compound_page
,
324 #ifdef CONFIG_HUGETLB_PAGE
325 [HUGETLB_PAGE_DTOR
] = free_huge_page
,
327 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
328 [TRANSHUGE_PAGE_DTOR
] = free_transhuge_page
,
332 int min_free_kbytes
= 1024;
333 int user_min_free_kbytes
= -1;
334 #ifdef CONFIG_DISCONTIGMEM
336 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
337 * are not on separate NUMA nodes. Functionally this works but with
338 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
339 * quite small. By default, do not boost watermarks on discontigmem as in
340 * many cases very high-order allocations like THP are likely to be
341 * unsupported and the premature reclaim offsets the advantage of long-term
342 * fragmentation avoidance.
344 int watermark_boost_factor __read_mostly
;
346 int watermark_boost_factor __read_mostly
= 15000;
348 int watermark_scale_factor
= 10;
350 static unsigned long nr_kernel_pages __initdata
;
351 static unsigned long nr_all_pages __initdata
;
352 static unsigned long dma_reserve __initdata
;
354 static unsigned long arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
355 static unsigned long arch_zone_highest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
356 static unsigned long required_kernelcore __initdata
;
357 static unsigned long required_kernelcore_percent __initdata
;
358 static unsigned long required_movablecore __initdata
;
359 static unsigned long required_movablecore_percent __initdata
;
360 static unsigned long zone_movable_pfn
[MAX_NUMNODES
] __initdata
;
361 static bool mirrored_kernelcore __meminitdata
;
363 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
365 EXPORT_SYMBOL(movable_zone
);
368 unsigned int nr_node_ids __read_mostly
= MAX_NUMNODES
;
369 unsigned int nr_online_nodes __read_mostly
= 1;
370 EXPORT_SYMBOL(nr_node_ids
);
371 EXPORT_SYMBOL(nr_online_nodes
);
374 int page_group_by_mobility_disabled __read_mostly
;
376 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
378 * During boot we initialize deferred pages on-demand, as needed, but once
379 * page_alloc_init_late() has finished, the deferred pages are all initialized,
380 * and we can permanently disable that path.
382 static DEFINE_STATIC_KEY_TRUE(deferred_pages
);
385 * Calling kasan_free_pages() only after deferred memory initialization
386 * has completed. Poisoning pages during deferred memory init will greatly
387 * lengthen the process and cause problem in large memory systems as the
388 * deferred pages initialization is done with interrupt disabled.
390 * Assuming that there will be no reference to those newly initialized
391 * pages before they are ever allocated, this should have no effect on
392 * KASAN memory tracking as the poison will be properly inserted at page
393 * allocation time. The only corner case is when pages are allocated by
394 * on-demand allocation and then freed again before the deferred pages
395 * initialization is done, but this is not likely to happen.
397 static inline void kasan_free_nondeferred_pages(struct page
*page
, int order
,
398 bool init
, fpi_t fpi_flags
)
400 if (static_branch_unlikely(&deferred_pages
))
402 if (!IS_ENABLED(CONFIG_KASAN_GENERIC
) &&
403 (fpi_flags
& FPI_SKIP_KASAN_POISON
))
405 kasan_free_pages(page
, order
, init
);
408 /* Returns true if the struct page for the pfn is uninitialised */
409 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
411 int nid
= early_pfn_to_nid(pfn
);
413 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
420 * Returns true when the remaining initialisation should be deferred until
421 * later in the boot cycle when it can be parallelised.
423 static bool __meminit
424 defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
426 static unsigned long prev_end_pfn
, nr_initialised
;
429 * prev_end_pfn static that contains the end of previous zone
430 * No need to protect because called very early in boot before smp_init.
432 if (prev_end_pfn
!= end_pfn
) {
433 prev_end_pfn
= end_pfn
;
437 /* Always populate low zones for address-constrained allocations */
438 if (end_pfn
< pgdat_end_pfn(NODE_DATA(nid
)))
441 if (NODE_DATA(nid
)->first_deferred_pfn
!= ULONG_MAX
)
444 * We start only with one section of pages, more pages are added as
445 * needed until the rest of deferred pages are initialized.
448 if ((nr_initialised
> PAGES_PER_SECTION
) &&
449 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
450 NODE_DATA(nid
)->first_deferred_pfn
= pfn
;
456 static inline void kasan_free_nondeferred_pages(struct page
*page
, int order
,
457 bool init
, fpi_t fpi_flags
)
459 if (!IS_ENABLED(CONFIG_KASAN_GENERIC
) &&
460 (fpi_flags
& FPI_SKIP_KASAN_POISON
))
462 kasan_free_pages(page
, order
, init
);
465 static inline bool early_page_uninitialised(unsigned long pfn
)
470 static inline bool defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
476 /* Return a pointer to the bitmap storing bits affecting a block of pages */
477 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
480 #ifdef CONFIG_SPARSEMEM
481 return section_to_usemap(__pfn_to_section(pfn
));
483 return page_zone(page
)->pageblock_flags
;
484 #endif /* CONFIG_SPARSEMEM */
487 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
489 #ifdef CONFIG_SPARSEMEM
490 pfn
&= (PAGES_PER_SECTION
-1);
492 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
493 #endif /* CONFIG_SPARSEMEM */
494 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
497 static __always_inline
498 unsigned long __get_pfnblock_flags_mask(struct page
*page
,
502 unsigned long *bitmap
;
503 unsigned long bitidx
, word_bitidx
;
506 bitmap
= get_pageblock_bitmap(page
, pfn
);
507 bitidx
= pfn_to_bitidx(page
, pfn
);
508 word_bitidx
= bitidx
/ BITS_PER_LONG
;
509 bitidx
&= (BITS_PER_LONG
-1);
511 word
= bitmap
[word_bitidx
];
512 return (word
>> bitidx
) & mask
;
516 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
517 * @page: The page within the block of interest
518 * @pfn: The target page frame number
519 * @mask: mask of bits that the caller is interested in
521 * Return: pageblock_bits flags
523 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
526 return __get_pfnblock_flags_mask(page
, pfn
, mask
);
529 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
531 return __get_pfnblock_flags_mask(page
, pfn
, MIGRATETYPE_MASK
);
535 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
536 * @page: The page within the block of interest
537 * @flags: The flags to set
538 * @pfn: The target page frame number
539 * @mask: mask of bits that the caller is interested in
541 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
545 unsigned long *bitmap
;
546 unsigned long bitidx
, word_bitidx
;
547 unsigned long old_word
, word
;
549 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
550 BUILD_BUG_ON(MIGRATE_TYPES
> (1 << PB_migratetype_bits
));
552 bitmap
= get_pageblock_bitmap(page
, pfn
);
553 bitidx
= pfn_to_bitidx(page
, pfn
);
554 word_bitidx
= bitidx
/ BITS_PER_LONG
;
555 bitidx
&= (BITS_PER_LONG
-1);
557 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
562 word
= READ_ONCE(bitmap
[word_bitidx
]);
564 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
565 if (word
== old_word
)
571 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
573 if (unlikely(page_group_by_mobility_disabled
&&
574 migratetype
< MIGRATE_PCPTYPES
))
575 migratetype
= MIGRATE_UNMOVABLE
;
577 set_pfnblock_flags_mask(page
, (unsigned long)migratetype
,
578 page_to_pfn(page
), MIGRATETYPE_MASK
);
581 #ifdef CONFIG_DEBUG_VM
582 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
586 unsigned long pfn
= page_to_pfn(page
);
587 unsigned long sp
, start_pfn
;
590 seq
= zone_span_seqbegin(zone
);
591 start_pfn
= zone
->zone_start_pfn
;
592 sp
= zone
->spanned_pages
;
593 if (!zone_spans_pfn(zone
, pfn
))
595 } while (zone_span_seqretry(zone
, seq
));
598 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
599 pfn
, zone_to_nid(zone
), zone
->name
,
600 start_pfn
, start_pfn
+ sp
);
605 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
607 if (!pfn_valid_within(page_to_pfn(page
)))
609 if (zone
!= page_zone(page
))
615 * Temporary debugging check for pages not lying within a given zone.
617 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
619 if (page_outside_zone_boundaries(zone
, page
))
621 if (!page_is_consistent(zone
, page
))
627 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
633 static void bad_page(struct page
*page
, const char *reason
)
635 static unsigned long resume
;
636 static unsigned long nr_shown
;
637 static unsigned long nr_unshown
;
640 * Allow a burst of 60 reports, then keep quiet for that minute;
641 * or allow a steady drip of one report per second.
643 if (nr_shown
== 60) {
644 if (time_before(jiffies
, resume
)) {
650 "BUG: Bad page state: %lu messages suppressed\n",
657 resume
= jiffies
+ 60 * HZ
;
659 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
660 current
->comm
, page_to_pfn(page
));
661 __dump_page(page
, reason
);
662 dump_page_owner(page
);
667 /* Leave bad fields for debug, except PageBuddy could make trouble */
668 page_mapcount_reset(page
); /* remove PageBuddy */
669 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
673 * Higher-order pages are called "compound pages". They are structured thusly:
675 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
677 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
678 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
680 * The first tail page's ->compound_dtor holds the offset in array of compound
681 * page destructors. See compound_page_dtors.
683 * The first tail page's ->compound_order holds the order of allocation.
684 * This usage means that zero-order pages may not be compound.
687 void free_compound_page(struct page
*page
)
689 mem_cgroup_uncharge(page
);
690 __free_pages_ok(page
, compound_order(page
), FPI_NONE
);
693 void prep_compound_page(struct page
*page
, unsigned int order
)
696 int nr_pages
= 1 << order
;
699 for (i
= 1; i
< nr_pages
; i
++) {
700 struct page
*p
= page
+ i
;
701 set_page_count(p
, 0);
702 p
->mapping
= TAIL_MAPPING
;
703 set_compound_head(p
, page
);
706 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
707 set_compound_order(page
, order
);
708 atomic_set(compound_mapcount_ptr(page
), -1);
709 if (hpage_pincount_available(page
))
710 atomic_set(compound_pincount_ptr(page
), 0);
713 #ifdef CONFIG_DEBUG_PAGEALLOC
714 unsigned int _debug_guardpage_minorder
;
716 bool _debug_pagealloc_enabled_early __read_mostly
717 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
718 EXPORT_SYMBOL(_debug_pagealloc_enabled_early
);
719 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled
);
720 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
722 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled
);
724 static int __init
early_debug_pagealloc(char *buf
)
726 return kstrtobool(buf
, &_debug_pagealloc_enabled_early
);
728 early_param("debug_pagealloc", early_debug_pagealloc
);
730 static int __init
debug_guardpage_minorder_setup(char *buf
)
734 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
735 pr_err("Bad debug_guardpage_minorder value\n");
738 _debug_guardpage_minorder
= res
;
739 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
742 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
744 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
745 unsigned int order
, int migratetype
)
747 if (!debug_guardpage_enabled())
750 if (order
>= debug_guardpage_minorder())
753 __SetPageGuard(page
);
754 INIT_LIST_HEAD(&page
->lru
);
755 set_page_private(page
, order
);
756 /* Guard pages are not available for any usage */
757 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
762 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
763 unsigned int order
, int migratetype
)
765 if (!debug_guardpage_enabled())
768 __ClearPageGuard(page
);
770 set_page_private(page
, 0);
771 if (!is_migrate_isolate(migratetype
))
772 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
775 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
776 unsigned int order
, int migratetype
) { return false; }
777 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
778 unsigned int order
, int migratetype
) {}
782 * Enable static keys related to various memory debugging and hardening options.
783 * Some override others, and depend on early params that are evaluated in the
784 * order of appearance. So we need to first gather the full picture of what was
785 * enabled, and then make decisions.
787 void init_mem_debugging_and_hardening(void)
789 bool page_poisoning_requested
= false;
791 #ifdef CONFIG_PAGE_POISONING
793 * Page poisoning is debug page alloc for some arches. If
794 * either of those options are enabled, enable poisoning.
796 if (page_poisoning_enabled() ||
797 (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC
) &&
798 debug_pagealloc_enabled())) {
799 static_branch_enable(&_page_poisoning_enabled
);
800 page_poisoning_requested
= true;
804 if (_init_on_alloc_enabled_early
) {
805 if (page_poisoning_requested
)
806 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
807 "will take precedence over init_on_alloc\n");
809 static_branch_enable(&init_on_alloc
);
811 if (_init_on_free_enabled_early
) {
812 if (page_poisoning_requested
)
813 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
814 "will take precedence over init_on_free\n");
816 static_branch_enable(&init_on_free
);
819 #ifdef CONFIG_DEBUG_PAGEALLOC
820 if (!debug_pagealloc_enabled())
823 static_branch_enable(&_debug_pagealloc_enabled
);
825 if (!debug_guardpage_minorder())
828 static_branch_enable(&_debug_guardpage_enabled
);
832 static inline void set_buddy_order(struct page
*page
, unsigned int order
)
834 set_page_private(page
, order
);
835 __SetPageBuddy(page
);
839 * This function checks whether a page is free && is the buddy
840 * we can coalesce a page and its buddy if
841 * (a) the buddy is not in a hole (check before calling!) &&
842 * (b) the buddy is in the buddy system &&
843 * (c) a page and its buddy have the same order &&
844 * (d) a page and its buddy are in the same zone.
846 * For recording whether a page is in the buddy system, we set PageBuddy.
847 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
849 * For recording page's order, we use page_private(page).
851 static inline bool page_is_buddy(struct page
*page
, struct page
*buddy
,
854 if (!page_is_guard(buddy
) && !PageBuddy(buddy
))
857 if (buddy_order(buddy
) != order
)
861 * zone check is done late to avoid uselessly calculating
862 * zone/node ids for pages that could never merge.
864 if (page_zone_id(page
) != page_zone_id(buddy
))
867 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
872 #ifdef CONFIG_COMPACTION
873 static inline struct capture_control
*task_capc(struct zone
*zone
)
875 struct capture_control
*capc
= current
->capture_control
;
877 return unlikely(capc
) &&
878 !(current
->flags
& PF_KTHREAD
) &&
880 capc
->cc
->zone
== zone
? capc
: NULL
;
884 compaction_capture(struct capture_control
*capc
, struct page
*page
,
885 int order
, int migratetype
)
887 if (!capc
|| order
!= capc
->cc
->order
)
890 /* Do not accidentally pollute CMA or isolated regions*/
891 if (is_migrate_cma(migratetype
) ||
892 is_migrate_isolate(migratetype
))
896 * Do not let lower order allocations polluate a movable pageblock.
897 * This might let an unmovable request use a reclaimable pageblock
898 * and vice-versa but no more than normal fallback logic which can
899 * have trouble finding a high-order free page.
901 if (order
< pageblock_order
&& migratetype
== MIGRATE_MOVABLE
)
909 static inline struct capture_control
*task_capc(struct zone
*zone
)
915 compaction_capture(struct capture_control
*capc
, struct page
*page
,
916 int order
, int migratetype
)
920 #endif /* CONFIG_COMPACTION */
922 /* Used for pages not on another list */
923 static inline void add_to_free_list(struct page
*page
, struct zone
*zone
,
924 unsigned int order
, int migratetype
)
926 struct free_area
*area
= &zone
->free_area
[order
];
928 list_add(&page
->lru
, &area
->free_list
[migratetype
]);
932 /* Used for pages not on another list */
933 static inline void add_to_free_list_tail(struct page
*page
, struct zone
*zone
,
934 unsigned int order
, int migratetype
)
936 struct free_area
*area
= &zone
->free_area
[order
];
938 list_add_tail(&page
->lru
, &area
->free_list
[migratetype
]);
943 * Used for pages which are on another list. Move the pages to the tail
944 * of the list - so the moved pages won't immediately be considered for
945 * allocation again (e.g., optimization for memory onlining).
947 static inline void move_to_free_list(struct page
*page
, struct zone
*zone
,
948 unsigned int order
, int migratetype
)
950 struct free_area
*area
= &zone
->free_area
[order
];
952 list_move_tail(&page
->lru
, &area
->free_list
[migratetype
]);
955 static inline void del_page_from_free_list(struct page
*page
, struct zone
*zone
,
958 /* clear reported state and update reported page count */
959 if (page_reported(page
))
960 __ClearPageReported(page
);
962 list_del(&page
->lru
);
963 __ClearPageBuddy(page
);
964 set_page_private(page
, 0);
965 zone
->free_area
[order
].nr_free
--;
969 * If this is not the largest possible page, check if the buddy
970 * of the next-highest order is free. If it is, it's possible
971 * that pages are being freed that will coalesce soon. In case,
972 * that is happening, add the free page to the tail of the list
973 * so it's less likely to be used soon and more likely to be merged
974 * as a higher order page
977 buddy_merge_likely(unsigned long pfn
, unsigned long buddy_pfn
,
978 struct page
*page
, unsigned int order
)
980 struct page
*higher_page
, *higher_buddy
;
981 unsigned long combined_pfn
;
983 if (order
>= MAX_ORDER
- 2)
986 if (!pfn_valid_within(buddy_pfn
))
989 combined_pfn
= buddy_pfn
& pfn
;
990 higher_page
= page
+ (combined_pfn
- pfn
);
991 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
992 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
994 return pfn_valid_within(buddy_pfn
) &&
995 page_is_buddy(higher_page
, higher_buddy
, order
+ 1);
999 * Freeing function for a buddy system allocator.
1001 * The concept of a buddy system is to maintain direct-mapped table
1002 * (containing bit values) for memory blocks of various "orders".
1003 * The bottom level table contains the map for the smallest allocatable
1004 * units of memory (here, pages), and each level above it describes
1005 * pairs of units from the levels below, hence, "buddies".
1006 * At a high level, all that happens here is marking the table entry
1007 * at the bottom level available, and propagating the changes upward
1008 * as necessary, plus some accounting needed to play nicely with other
1009 * parts of the VM system.
1010 * At each level, we keep a list of pages, which are heads of continuous
1011 * free pages of length of (1 << order) and marked with PageBuddy.
1012 * Page's order is recorded in page_private(page) field.
1013 * So when we are allocating or freeing one, we can derive the state of the
1014 * other. That is, if we allocate a small block, and both were
1015 * free, the remainder of the region must be split into blocks.
1016 * If a block is freed, and its buddy is also free, then this
1017 * triggers coalescing into a block of larger size.
1022 static inline void __free_one_page(struct page
*page
,
1024 struct zone
*zone
, unsigned int order
,
1025 int migratetype
, fpi_t fpi_flags
)
1027 struct capture_control
*capc
= task_capc(zone
);
1028 unsigned long buddy_pfn
;
1029 unsigned long combined_pfn
;
1030 unsigned int max_order
;
1034 max_order
= min_t(unsigned int, MAX_ORDER
- 1, pageblock_order
);
1036 VM_BUG_ON(!zone_is_initialized(zone
));
1037 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
1039 VM_BUG_ON(migratetype
== -1);
1040 if (likely(!is_migrate_isolate(migratetype
)))
1041 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
1043 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
1044 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
1047 while (order
< max_order
) {
1048 if (compaction_capture(capc
, page
, order
, migratetype
)) {
1049 __mod_zone_freepage_state(zone
, -(1 << order
),
1053 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1054 buddy
= page
+ (buddy_pfn
- pfn
);
1056 if (!pfn_valid_within(buddy_pfn
))
1058 if (!page_is_buddy(page
, buddy
, order
))
1061 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
1062 * merge with it and move up one order.
1064 if (page_is_guard(buddy
))
1065 clear_page_guard(zone
, buddy
, order
, migratetype
);
1067 del_page_from_free_list(buddy
, zone
, order
);
1068 combined_pfn
= buddy_pfn
& pfn
;
1069 page
= page
+ (combined_pfn
- pfn
);
1073 if (order
< MAX_ORDER
- 1) {
1074 /* If we are here, it means order is >= pageblock_order.
1075 * We want to prevent merge between freepages on isolate
1076 * pageblock and normal pageblock. Without this, pageblock
1077 * isolation could cause incorrect freepage or CMA accounting.
1079 * We don't want to hit this code for the more frequent
1080 * low-order merging.
1082 if (unlikely(has_isolate_pageblock(zone
))) {
1085 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1086 buddy
= page
+ (buddy_pfn
- pfn
);
1087 buddy_mt
= get_pageblock_migratetype(buddy
);
1089 if (migratetype
!= buddy_mt
1090 && (is_migrate_isolate(migratetype
) ||
1091 is_migrate_isolate(buddy_mt
)))
1094 max_order
= order
+ 1;
1095 goto continue_merging
;
1099 set_buddy_order(page
, order
);
1101 if (fpi_flags
& FPI_TO_TAIL
)
1103 else if (is_shuffle_order(order
))
1104 to_tail
= shuffle_pick_tail();
1106 to_tail
= buddy_merge_likely(pfn
, buddy_pfn
, page
, order
);
1109 add_to_free_list_tail(page
, zone
, order
, migratetype
);
1111 add_to_free_list(page
, zone
, order
, migratetype
);
1113 /* Notify page reporting subsystem of freed page */
1114 if (!(fpi_flags
& FPI_SKIP_REPORT_NOTIFY
))
1115 page_reporting_notify_free(order
);
1119 * A bad page could be due to a number of fields. Instead of multiple branches,
1120 * try and check multiple fields with one check. The caller must do a detailed
1121 * check if necessary.
1123 static inline bool page_expected_state(struct page
*page
,
1124 unsigned long check_flags
)
1126 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1129 if (unlikely((unsigned long)page
->mapping
|
1130 page_ref_count(page
) |
1134 (page
->flags
& check_flags
)))
1140 static const char *page_bad_reason(struct page
*page
, unsigned long flags
)
1142 const char *bad_reason
= NULL
;
1144 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1145 bad_reason
= "nonzero mapcount";
1146 if (unlikely(page
->mapping
!= NULL
))
1147 bad_reason
= "non-NULL mapping";
1148 if (unlikely(page_ref_count(page
) != 0))
1149 bad_reason
= "nonzero _refcount";
1150 if (unlikely(page
->flags
& flags
)) {
1151 if (flags
== PAGE_FLAGS_CHECK_AT_PREP
)
1152 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1154 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1157 if (unlikely(page
->memcg_data
))
1158 bad_reason
= "page still charged to cgroup";
1163 static void check_free_page_bad(struct page
*page
)
1166 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_FREE
));
1169 static inline int check_free_page(struct page
*page
)
1171 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
1174 /* Something has gone sideways, find it */
1175 check_free_page_bad(page
);
1179 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
1184 * We rely page->lru.next never has bit 0 set, unless the page
1185 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1187 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
1189 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
1193 switch (page
- head_page
) {
1195 /* the first tail page: ->mapping may be compound_mapcount() */
1196 if (unlikely(compound_mapcount(page
))) {
1197 bad_page(page
, "nonzero compound_mapcount");
1203 * the second tail page: ->mapping is
1204 * deferred_list.next -- ignore value.
1208 if (page
->mapping
!= TAIL_MAPPING
) {
1209 bad_page(page
, "corrupted mapping in tail page");
1214 if (unlikely(!PageTail(page
))) {
1215 bad_page(page
, "PageTail not set");
1218 if (unlikely(compound_head(page
) != head_page
)) {
1219 bad_page(page
, "compound_head not consistent");
1224 page
->mapping
= NULL
;
1225 clear_compound_head(page
);
1229 static void kernel_init_free_pages(struct page
*page
, int numpages
)
1233 /* s390's use of memset() could override KASAN redzones. */
1234 kasan_disable_current();
1235 for (i
= 0; i
< numpages
; i
++) {
1236 u8 tag
= page_kasan_tag(page
+ i
);
1237 page_kasan_tag_reset(page
+ i
);
1238 clear_highpage(page
+ i
);
1239 page_kasan_tag_set(page
+ i
, tag
);
1241 kasan_enable_current();
1244 static __always_inline
bool free_pages_prepare(struct page
*page
,
1245 unsigned int order
, bool check_free
, fpi_t fpi_flags
)
1250 VM_BUG_ON_PAGE(PageTail(page
), page
);
1252 trace_mm_page_free(page
, order
);
1254 if (unlikely(PageHWPoison(page
)) && !order
) {
1256 * Do not let hwpoison pages hit pcplists/buddy
1257 * Untie memcg state and reset page's owner
1259 if (memcg_kmem_enabled() && PageMemcgKmem(page
))
1260 __memcg_kmem_uncharge_page(page
, order
);
1261 reset_page_owner(page
, order
);
1266 * Check tail pages before head page information is cleared to
1267 * avoid checking PageCompound for order-0 pages.
1269 if (unlikely(order
)) {
1270 bool compound
= PageCompound(page
);
1273 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1276 ClearPageDoubleMap(page
);
1277 for (i
= 1; i
< (1 << order
); i
++) {
1279 bad
+= free_tail_pages_check(page
, page
+ i
);
1280 if (unlikely(check_free_page(page
+ i
))) {
1284 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1287 if (PageMappingFlags(page
))
1288 page
->mapping
= NULL
;
1289 if (memcg_kmem_enabled() && PageMemcgKmem(page
))
1290 __memcg_kmem_uncharge_page(page
, order
);
1292 bad
+= check_free_page(page
);
1296 page_cpupid_reset_last(page
);
1297 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1298 reset_page_owner(page
, order
);
1300 if (!PageHighMem(page
)) {
1301 debug_check_no_locks_freed(page_address(page
),
1302 PAGE_SIZE
<< order
);
1303 debug_check_no_obj_freed(page_address(page
),
1304 PAGE_SIZE
<< order
);
1307 kernel_poison_pages(page
, 1 << order
);
1310 * As memory initialization might be integrated into KASAN,
1311 * kasan_free_pages and kernel_init_free_pages must be
1312 * kept together to avoid discrepancies in behavior.
1314 * With hardware tag-based KASAN, memory tags must be set before the
1315 * page becomes unavailable via debug_pagealloc or arch_free_page.
1317 init
= want_init_on_free();
1318 if (init
&& !kasan_has_integrated_init())
1319 kernel_init_free_pages(page
, 1 << order
);
1320 kasan_free_nondeferred_pages(page
, order
, init
, fpi_flags
);
1323 * arch_free_page() can make the page's contents inaccessible. s390
1324 * does this. So nothing which can access the page's contents should
1325 * happen after this.
1327 arch_free_page(page
, order
);
1329 debug_pagealloc_unmap_pages(page
, 1 << order
);
1334 #ifdef CONFIG_DEBUG_VM
1336 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1337 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1338 * moved from pcp lists to free lists.
1340 static bool free_pcp_prepare(struct page
*page
)
1342 return free_pages_prepare(page
, 0, true, FPI_NONE
);
1345 static bool bulkfree_pcp_prepare(struct page
*page
)
1347 if (debug_pagealloc_enabled_static())
1348 return check_free_page(page
);
1354 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1355 * moving from pcp lists to free list in order to reduce overhead. With
1356 * debug_pagealloc enabled, they are checked also immediately when being freed
1359 static bool free_pcp_prepare(struct page
*page
)
1361 if (debug_pagealloc_enabled_static())
1362 return free_pages_prepare(page
, 0, true, FPI_NONE
);
1364 return free_pages_prepare(page
, 0, false, FPI_NONE
);
1367 static bool bulkfree_pcp_prepare(struct page
*page
)
1369 return check_free_page(page
);
1371 #endif /* CONFIG_DEBUG_VM */
1373 static inline void prefetch_buddy(struct page
*page
)
1375 unsigned long pfn
= page_to_pfn(page
);
1376 unsigned long buddy_pfn
= __find_buddy_pfn(pfn
, 0);
1377 struct page
*buddy
= page
+ (buddy_pfn
- pfn
);
1383 * Frees a number of pages from the PCP lists
1384 * Assumes all pages on list are in same zone, and of same order.
1385 * count is the number of pages to free.
1387 * If the zone was previously in an "all pages pinned" state then look to
1388 * see if this freeing clears that state.
1390 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1391 * pinned" detection logic.
1393 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1394 struct per_cpu_pages
*pcp
)
1396 int migratetype
= 0;
1398 int prefetch_nr
= READ_ONCE(pcp
->batch
);
1399 bool isolated_pageblocks
;
1400 struct page
*page
, *tmp
;
1404 * Ensure proper count is passed which otherwise would stuck in the
1405 * below while (list_empty(list)) loop.
1407 count
= min(pcp
->count
, count
);
1409 struct list_head
*list
;
1412 * Remove pages from lists in a round-robin fashion. A
1413 * batch_free count is maintained that is incremented when an
1414 * empty list is encountered. This is so more pages are freed
1415 * off fuller lists instead of spinning excessively around empty
1420 if (++migratetype
== MIGRATE_PCPTYPES
)
1422 list
= &pcp
->lists
[migratetype
];
1423 } while (list_empty(list
));
1425 /* This is the only non-empty list. Free them all. */
1426 if (batch_free
== MIGRATE_PCPTYPES
)
1430 page
= list_last_entry(list
, struct page
, lru
);
1431 /* must delete to avoid corrupting pcp list */
1432 list_del(&page
->lru
);
1435 if (bulkfree_pcp_prepare(page
))
1438 list_add_tail(&page
->lru
, &head
);
1441 * We are going to put the page back to the global
1442 * pool, prefetch its buddy to speed up later access
1443 * under zone->lock. It is believed the overhead of
1444 * an additional test and calculating buddy_pfn here
1445 * can be offset by reduced memory latency later. To
1446 * avoid excessive prefetching due to large count, only
1447 * prefetch buddy for the first pcp->batch nr of pages.
1450 prefetch_buddy(page
);
1453 } while (--count
&& --batch_free
&& !list_empty(list
));
1456 spin_lock(&zone
->lock
);
1457 isolated_pageblocks
= has_isolate_pageblock(zone
);
1460 * Use safe version since after __free_one_page(),
1461 * page->lru.next will not point to original list.
1463 list_for_each_entry_safe(page
, tmp
, &head
, lru
) {
1464 int mt
= get_pcppage_migratetype(page
);
1465 /* MIGRATE_ISOLATE page should not go to pcplists */
1466 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1467 /* Pageblock could have been isolated meanwhile */
1468 if (unlikely(isolated_pageblocks
))
1469 mt
= get_pageblock_migratetype(page
);
1471 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
, FPI_NONE
);
1472 trace_mm_page_pcpu_drain(page
, 0, mt
);
1474 spin_unlock(&zone
->lock
);
1477 static void free_one_page(struct zone
*zone
,
1478 struct page
*page
, unsigned long pfn
,
1480 int migratetype
, fpi_t fpi_flags
)
1482 spin_lock(&zone
->lock
);
1483 if (unlikely(has_isolate_pageblock(zone
) ||
1484 is_migrate_isolate(migratetype
))) {
1485 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1487 __free_one_page(page
, pfn
, zone
, order
, migratetype
, fpi_flags
);
1488 spin_unlock(&zone
->lock
);
1491 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1492 unsigned long zone
, int nid
)
1494 mm_zero_struct_page(page
);
1495 set_page_links(page
, zone
, nid
, pfn
);
1496 init_page_count(page
);
1497 page_mapcount_reset(page
);
1498 page_cpupid_reset_last(page
);
1499 page_kasan_tag_reset(page
);
1501 INIT_LIST_HEAD(&page
->lru
);
1502 #ifdef WANT_PAGE_VIRTUAL
1503 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1504 if (!is_highmem_idx(zone
))
1505 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1509 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1510 static void __meminit
init_reserved_page(unsigned long pfn
)
1515 if (!early_page_uninitialised(pfn
))
1518 nid
= early_pfn_to_nid(pfn
);
1519 pgdat
= NODE_DATA(nid
);
1521 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1522 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1524 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1527 __init_single_page(pfn_to_page(pfn
), pfn
, zid
, nid
);
1530 static inline void init_reserved_page(unsigned long pfn
)
1533 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1536 * Initialised pages do not have PageReserved set. This function is
1537 * called for each range allocated by the bootmem allocator and
1538 * marks the pages PageReserved. The remaining valid pages are later
1539 * sent to the buddy page allocator.
1541 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1543 unsigned long start_pfn
= PFN_DOWN(start
);
1544 unsigned long end_pfn
= PFN_UP(end
);
1546 for (; start_pfn
< end_pfn
; start_pfn
++) {
1547 if (pfn_valid(start_pfn
)) {
1548 struct page
*page
= pfn_to_page(start_pfn
);
1550 init_reserved_page(start_pfn
);
1552 /* Avoid false-positive PageTail() */
1553 INIT_LIST_HEAD(&page
->lru
);
1556 * no need for atomic set_bit because the struct
1557 * page is not visible yet so nobody should
1560 __SetPageReserved(page
);
1565 static void __free_pages_ok(struct page
*page
, unsigned int order
,
1568 unsigned long flags
;
1570 unsigned long pfn
= page_to_pfn(page
);
1572 if (!free_pages_prepare(page
, order
, true, fpi_flags
))
1575 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1576 local_irq_save(flags
);
1577 __count_vm_events(PGFREE
, 1 << order
);
1578 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
,
1580 local_irq_restore(flags
);
1583 void __free_pages_core(struct page
*page
, unsigned int order
)
1585 unsigned int nr_pages
= 1 << order
;
1586 struct page
*p
= page
;
1590 * When initializing the memmap, __init_single_page() sets the refcount
1591 * of all pages to 1 ("allocated"/"not free"). We have to set the
1592 * refcount of all involved pages to 0.
1595 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1597 __ClearPageReserved(p
);
1598 set_page_count(p
, 0);
1600 __ClearPageReserved(p
);
1601 set_page_count(p
, 0);
1603 atomic_long_add(nr_pages
, &page_zone(page
)->managed_pages
);
1606 * Bypass PCP and place fresh pages right to the tail, primarily
1607 * relevant for memory onlining.
1609 __free_pages_ok(page
, order
, FPI_TO_TAIL
| FPI_SKIP_KASAN_POISON
);
1612 #ifdef CONFIG_NEED_MULTIPLE_NODES
1615 * During memory init memblocks map pfns to nids. The search is expensive and
1616 * this caches recent lookups. The implementation of __early_pfn_to_nid
1617 * treats start/end as pfns.
1619 struct mminit_pfnnid_cache
{
1620 unsigned long last_start
;
1621 unsigned long last_end
;
1625 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1628 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1630 static int __meminit
__early_pfn_to_nid(unsigned long pfn
,
1631 struct mminit_pfnnid_cache
*state
)
1633 unsigned long start_pfn
, end_pfn
;
1636 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
1637 return state
->last_nid
;
1639 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
1640 if (nid
!= NUMA_NO_NODE
) {
1641 state
->last_start
= start_pfn
;
1642 state
->last_end
= end_pfn
;
1643 state
->last_nid
= nid
;
1649 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1651 static DEFINE_SPINLOCK(early_pfn_lock
);
1654 spin_lock(&early_pfn_lock
);
1655 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1657 nid
= first_online_node
;
1658 spin_unlock(&early_pfn_lock
);
1662 #endif /* CONFIG_NEED_MULTIPLE_NODES */
1664 void __init
memblock_free_pages(struct page
*page
, unsigned long pfn
,
1667 if (early_page_uninitialised(pfn
))
1669 __free_pages_core(page
, order
);
1673 * Check that the whole (or subset of) a pageblock given by the interval of
1674 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1675 * with the migration of free compaction scanner. The scanners then need to
1676 * use only pfn_valid_within() check for arches that allow holes within
1679 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1681 * It's possible on some configurations to have a setup like node0 node1 node0
1682 * i.e. it's possible that all pages within a zones range of pages do not
1683 * belong to a single zone. We assume that a border between node0 and node1
1684 * can occur within a single pageblock, but not a node0 node1 node0
1685 * interleaving within a single pageblock. It is therefore sufficient to check
1686 * the first and last page of a pageblock and avoid checking each individual
1687 * page in a pageblock.
1689 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1690 unsigned long end_pfn
, struct zone
*zone
)
1692 struct page
*start_page
;
1693 struct page
*end_page
;
1695 /* end_pfn is one past the range we are checking */
1698 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1701 start_page
= pfn_to_online_page(start_pfn
);
1705 if (page_zone(start_page
) != zone
)
1708 end_page
= pfn_to_page(end_pfn
);
1710 /* This gives a shorter code than deriving page_zone(end_page) */
1711 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1717 void set_zone_contiguous(struct zone
*zone
)
1719 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1720 unsigned long block_end_pfn
;
1722 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1723 for (; block_start_pfn
< zone_end_pfn(zone
);
1724 block_start_pfn
= block_end_pfn
,
1725 block_end_pfn
+= pageblock_nr_pages
) {
1727 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1729 if (!__pageblock_pfn_to_page(block_start_pfn
,
1730 block_end_pfn
, zone
))
1735 /* We confirm that there is no hole */
1736 zone
->contiguous
= true;
1739 void clear_zone_contiguous(struct zone
*zone
)
1741 zone
->contiguous
= false;
1744 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1745 static void __init
deferred_free_range(unsigned long pfn
,
1746 unsigned long nr_pages
)
1754 page
= pfn_to_page(pfn
);
1756 /* Free a large naturally-aligned chunk if possible */
1757 if (nr_pages
== pageblock_nr_pages
&&
1758 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1759 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1760 __free_pages_core(page
, pageblock_order
);
1764 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1765 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1766 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1767 __free_pages_core(page
, 0);
1771 /* Completion tracking for deferred_init_memmap() threads */
1772 static atomic_t pgdat_init_n_undone __initdata
;
1773 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1775 static inline void __init
pgdat_init_report_one_done(void)
1777 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1778 complete(&pgdat_init_all_done_comp
);
1782 * Returns true if page needs to be initialized or freed to buddy allocator.
1784 * First we check if pfn is valid on architectures where it is possible to have
1785 * holes within pageblock_nr_pages. On systems where it is not possible, this
1786 * function is optimized out.
1788 * Then, we check if a current large page is valid by only checking the validity
1791 static inline bool __init
deferred_pfn_valid(unsigned long pfn
)
1793 if (!pfn_valid_within(pfn
))
1795 if (!(pfn
& (pageblock_nr_pages
- 1)) && !pfn_valid(pfn
))
1801 * Free pages to buddy allocator. Try to free aligned pages in
1802 * pageblock_nr_pages sizes.
1804 static void __init
deferred_free_pages(unsigned long pfn
,
1805 unsigned long end_pfn
)
1807 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1808 unsigned long nr_free
= 0;
1810 for (; pfn
< end_pfn
; pfn
++) {
1811 if (!deferred_pfn_valid(pfn
)) {
1812 deferred_free_range(pfn
- nr_free
, nr_free
);
1814 } else if (!(pfn
& nr_pgmask
)) {
1815 deferred_free_range(pfn
- nr_free
, nr_free
);
1821 /* Free the last block of pages to allocator */
1822 deferred_free_range(pfn
- nr_free
, nr_free
);
1826 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1827 * by performing it only once every pageblock_nr_pages.
1828 * Return number of pages initialized.
1830 static unsigned long __init
deferred_init_pages(struct zone
*zone
,
1832 unsigned long end_pfn
)
1834 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1835 int nid
= zone_to_nid(zone
);
1836 unsigned long nr_pages
= 0;
1837 int zid
= zone_idx(zone
);
1838 struct page
*page
= NULL
;
1840 for (; pfn
< end_pfn
; pfn
++) {
1841 if (!deferred_pfn_valid(pfn
)) {
1844 } else if (!page
|| !(pfn
& nr_pgmask
)) {
1845 page
= pfn_to_page(pfn
);
1849 __init_single_page(page
, pfn
, zid
, nid
);
1856 * This function is meant to pre-load the iterator for the zone init.
1857 * Specifically it walks through the ranges until we are caught up to the
1858 * first_init_pfn value and exits there. If we never encounter the value we
1859 * return false indicating there are no valid ranges left.
1862 deferred_init_mem_pfn_range_in_zone(u64
*i
, struct zone
*zone
,
1863 unsigned long *spfn
, unsigned long *epfn
,
1864 unsigned long first_init_pfn
)
1869 * Start out by walking through the ranges in this zone that have
1870 * already been initialized. We don't need to do anything with them
1871 * so we just need to flush them out of the system.
1873 for_each_free_mem_pfn_range_in_zone(j
, zone
, spfn
, epfn
) {
1874 if (*epfn
<= first_init_pfn
)
1876 if (*spfn
< first_init_pfn
)
1877 *spfn
= first_init_pfn
;
1886 * Initialize and free pages. We do it in two loops: first we initialize
1887 * struct page, then free to buddy allocator, because while we are
1888 * freeing pages we can access pages that are ahead (computing buddy
1889 * page in __free_one_page()).
1891 * In order to try and keep some memory in the cache we have the loop
1892 * broken along max page order boundaries. This way we will not cause
1893 * any issues with the buddy page computation.
1895 static unsigned long __init
1896 deferred_init_maxorder(u64
*i
, struct zone
*zone
, unsigned long *start_pfn
,
1897 unsigned long *end_pfn
)
1899 unsigned long mo_pfn
= ALIGN(*start_pfn
+ 1, MAX_ORDER_NR_PAGES
);
1900 unsigned long spfn
= *start_pfn
, epfn
= *end_pfn
;
1901 unsigned long nr_pages
= 0;
1904 /* First we loop through and initialize the page values */
1905 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, start_pfn
, end_pfn
) {
1908 if (mo_pfn
<= *start_pfn
)
1911 t
= min(mo_pfn
, *end_pfn
);
1912 nr_pages
+= deferred_init_pages(zone
, *start_pfn
, t
);
1914 if (mo_pfn
< *end_pfn
) {
1915 *start_pfn
= mo_pfn
;
1920 /* Reset values and now loop through freeing pages as needed */
1923 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, &spfn
, &epfn
) {
1929 t
= min(mo_pfn
, epfn
);
1930 deferred_free_pages(spfn
, t
);
1940 deferred_init_memmap_chunk(unsigned long start_pfn
, unsigned long end_pfn
,
1943 unsigned long spfn
, epfn
;
1944 struct zone
*zone
= arg
;
1947 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
, start_pfn
);
1950 * Initialize and free pages in MAX_ORDER sized increments so that we
1951 * can avoid introducing any issues with the buddy allocator.
1953 while (spfn
< end_pfn
) {
1954 deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1959 /* An arch may override for more concurrency. */
1961 deferred_page_init_max_threads(const struct cpumask
*node_cpumask
)
1966 /* Initialise remaining memory on a node */
1967 static int __init
deferred_init_memmap(void *data
)
1969 pg_data_t
*pgdat
= data
;
1970 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1971 unsigned long spfn
= 0, epfn
= 0;
1972 unsigned long first_init_pfn
, flags
;
1973 unsigned long start
= jiffies
;
1975 int zid
, max_threads
;
1978 /* Bind memory initialisation thread to a local node if possible */
1979 if (!cpumask_empty(cpumask
))
1980 set_cpus_allowed_ptr(current
, cpumask
);
1982 pgdat_resize_lock(pgdat
, &flags
);
1983 first_init_pfn
= pgdat
->first_deferred_pfn
;
1984 if (first_init_pfn
== ULONG_MAX
) {
1985 pgdat_resize_unlock(pgdat
, &flags
);
1986 pgdat_init_report_one_done();
1990 /* Sanity check boundaries */
1991 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1992 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1993 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1996 * Once we unlock here, the zone cannot be grown anymore, thus if an
1997 * interrupt thread must allocate this early in boot, zone must be
1998 * pre-grown prior to start of deferred page initialization.
2000 pgdat_resize_unlock(pgdat
, &flags
);
2002 /* Only the highest zone is deferred so find it */
2003 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
2004 zone
= pgdat
->node_zones
+ zid
;
2005 if (first_init_pfn
< zone_end_pfn(zone
))
2009 /* If the zone is empty somebody else may have cleared out the zone */
2010 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
2014 max_threads
= deferred_page_init_max_threads(cpumask
);
2016 while (spfn
< epfn
) {
2017 unsigned long epfn_align
= ALIGN(epfn
, PAGES_PER_SECTION
);
2018 struct padata_mt_job job
= {
2019 .thread_fn
= deferred_init_memmap_chunk
,
2022 .size
= epfn_align
- spfn
,
2023 .align
= PAGES_PER_SECTION
,
2024 .min_chunk
= PAGES_PER_SECTION
,
2025 .max_threads
= max_threads
,
2028 padata_do_multithreaded(&job
);
2029 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
2033 /* Sanity check that the next zone really is unpopulated */
2034 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
2036 pr_info("node %d deferred pages initialised in %ums\n",
2037 pgdat
->node_id
, jiffies_to_msecs(jiffies
- start
));
2039 pgdat_init_report_one_done();
2044 * If this zone has deferred pages, try to grow it by initializing enough
2045 * deferred pages to satisfy the allocation specified by order, rounded up to
2046 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
2047 * of SECTION_SIZE bytes by initializing struct pages in increments of
2048 * PAGES_PER_SECTION * sizeof(struct page) bytes.
2050 * Return true when zone was grown, otherwise return false. We return true even
2051 * when we grow less than requested, to let the caller decide if there are
2052 * enough pages to satisfy the allocation.
2054 * Note: We use noinline because this function is needed only during boot, and
2055 * it is called from a __ref function _deferred_grow_zone. This way we are
2056 * making sure that it is not inlined into permanent text section.
2058 static noinline
bool __init
2059 deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2061 unsigned long nr_pages_needed
= ALIGN(1 << order
, PAGES_PER_SECTION
);
2062 pg_data_t
*pgdat
= zone
->zone_pgdat
;
2063 unsigned long first_deferred_pfn
= pgdat
->first_deferred_pfn
;
2064 unsigned long spfn
, epfn
, flags
;
2065 unsigned long nr_pages
= 0;
2068 /* Only the last zone may have deferred pages */
2069 if (zone_end_pfn(zone
) != pgdat_end_pfn(pgdat
))
2072 pgdat_resize_lock(pgdat
, &flags
);
2075 * If someone grew this zone while we were waiting for spinlock, return
2076 * true, as there might be enough pages already.
2078 if (first_deferred_pfn
!= pgdat
->first_deferred_pfn
) {
2079 pgdat_resize_unlock(pgdat
, &flags
);
2083 /* If the zone is empty somebody else may have cleared out the zone */
2084 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
2085 first_deferred_pfn
)) {
2086 pgdat
->first_deferred_pfn
= ULONG_MAX
;
2087 pgdat_resize_unlock(pgdat
, &flags
);
2088 /* Retry only once. */
2089 return first_deferred_pfn
!= ULONG_MAX
;
2093 * Initialize and free pages in MAX_ORDER sized increments so
2094 * that we can avoid introducing any issues with the buddy
2097 while (spfn
< epfn
) {
2098 /* update our first deferred PFN for this section */
2099 first_deferred_pfn
= spfn
;
2101 nr_pages
+= deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
2102 touch_nmi_watchdog();
2104 /* We should only stop along section boundaries */
2105 if ((first_deferred_pfn
^ spfn
) < PAGES_PER_SECTION
)
2108 /* If our quota has been met we can stop here */
2109 if (nr_pages
>= nr_pages_needed
)
2113 pgdat
->first_deferred_pfn
= spfn
;
2114 pgdat_resize_unlock(pgdat
, &flags
);
2116 return nr_pages
> 0;
2120 * deferred_grow_zone() is __init, but it is called from
2121 * get_page_from_freelist() during early boot until deferred_pages permanently
2122 * disables this call. This is why we have refdata wrapper to avoid warning,
2123 * and to ensure that the function body gets unloaded.
2126 _deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2128 return deferred_grow_zone(zone
, order
);
2131 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2133 void __init
page_alloc_init_late(void)
2138 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2140 /* There will be num_node_state(N_MEMORY) threads */
2141 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
2142 for_each_node_state(nid
, N_MEMORY
) {
2143 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
2146 /* Block until all are initialised */
2147 wait_for_completion(&pgdat_init_all_done_comp
);
2150 * The number of managed pages has changed due to the initialisation
2151 * so the pcpu batch and high limits needs to be updated or the limits
2152 * will be artificially small.
2154 for_each_populated_zone(zone
)
2155 zone_pcp_update(zone
);
2158 * We initialized the rest of the deferred pages. Permanently disable
2159 * on-demand struct page initialization.
2161 static_branch_disable(&deferred_pages
);
2163 /* Reinit limits that are based on free pages after the kernel is up */
2164 files_maxfiles_init();
2169 /* Discard memblock private memory */
2172 for_each_node_state(nid
, N_MEMORY
)
2173 shuffle_free_memory(NODE_DATA(nid
));
2175 for_each_populated_zone(zone
)
2176 set_zone_contiguous(zone
);
2180 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2181 void __init
init_cma_reserved_pageblock(struct page
*page
)
2183 unsigned i
= pageblock_nr_pages
;
2184 struct page
*p
= page
;
2187 __ClearPageReserved(p
);
2188 set_page_count(p
, 0);
2191 set_pageblock_migratetype(page
, MIGRATE_CMA
);
2193 if (pageblock_order
>= MAX_ORDER
) {
2194 i
= pageblock_nr_pages
;
2197 set_page_refcounted(p
);
2198 __free_pages(p
, MAX_ORDER
- 1);
2199 p
+= MAX_ORDER_NR_PAGES
;
2200 } while (i
-= MAX_ORDER_NR_PAGES
);
2202 set_page_refcounted(page
);
2203 __free_pages(page
, pageblock_order
);
2206 adjust_managed_page_count(page
, pageblock_nr_pages
);
2207 page_zone(page
)->cma_pages
+= pageblock_nr_pages
;
2212 * The order of subdivision here is critical for the IO subsystem.
2213 * Please do not alter this order without good reasons and regression
2214 * testing. Specifically, as large blocks of memory are subdivided,
2215 * the order in which smaller blocks are delivered depends on the order
2216 * they're subdivided in this function. This is the primary factor
2217 * influencing the order in which pages are delivered to the IO
2218 * subsystem according to empirical testing, and this is also justified
2219 * by considering the behavior of a buddy system containing a single
2220 * large block of memory acted on by a series of small allocations.
2221 * This behavior is a critical factor in sglist merging's success.
2225 static inline void expand(struct zone
*zone
, struct page
*page
,
2226 int low
, int high
, int migratetype
)
2228 unsigned long size
= 1 << high
;
2230 while (high
> low
) {
2233 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
2236 * Mark as guard pages (or page), that will allow to
2237 * merge back to allocator when buddy will be freed.
2238 * Corresponding page table entries will not be touched,
2239 * pages will stay not present in virtual address space
2241 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
2244 add_to_free_list(&page
[size
], zone
, high
, migratetype
);
2245 set_buddy_order(&page
[size
], high
);
2249 static void check_new_page_bad(struct page
*page
)
2251 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
2252 /* Don't complain about hwpoisoned pages */
2253 page_mapcount_reset(page
); /* remove PageBuddy */
2258 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_PREP
));
2262 * This page is about to be returned from the page allocator
2264 static inline int check_new_page(struct page
*page
)
2266 if (likely(page_expected_state(page
,
2267 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
2270 check_new_page_bad(page
);
2274 #ifdef CONFIG_DEBUG_VM
2276 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2277 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2278 * also checked when pcp lists are refilled from the free lists.
2280 static inline bool check_pcp_refill(struct page
*page
)
2282 if (debug_pagealloc_enabled_static())
2283 return check_new_page(page
);
2288 static inline bool check_new_pcp(struct page
*page
)
2290 return check_new_page(page
);
2294 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2295 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2296 * enabled, they are also checked when being allocated from the pcp lists.
2298 static inline bool check_pcp_refill(struct page
*page
)
2300 return check_new_page(page
);
2302 static inline bool check_new_pcp(struct page
*page
)
2304 if (debug_pagealloc_enabled_static())
2305 return check_new_page(page
);
2309 #endif /* CONFIG_DEBUG_VM */
2311 static bool check_new_pages(struct page
*page
, unsigned int order
)
2314 for (i
= 0; i
< (1 << order
); i
++) {
2315 struct page
*p
= page
+ i
;
2317 if (unlikely(check_new_page(p
)))
2324 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
2329 set_page_private(page
, 0);
2330 set_page_refcounted(page
);
2332 arch_alloc_page(page
, order
);
2333 debug_pagealloc_map_pages(page
, 1 << order
);
2336 * Page unpoisoning must happen before memory initialization.
2337 * Otherwise, the poison pattern will be overwritten for __GFP_ZERO
2338 * allocations and the page unpoisoning code will complain.
2340 kernel_unpoison_pages(page
, 1 << order
);
2343 * As memory initialization might be integrated into KASAN,
2344 * kasan_alloc_pages and kernel_init_free_pages must be
2345 * kept together to avoid discrepancies in behavior.
2347 init
= !want_init_on_free() && want_init_on_alloc(gfp_flags
);
2348 kasan_alloc_pages(page
, order
, init
);
2349 if (init
&& !kasan_has_integrated_init())
2350 kernel_init_free_pages(page
, 1 << order
);
2352 set_page_owner(page
, order
, gfp_flags
);
2355 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
2356 unsigned int alloc_flags
)
2358 post_alloc_hook(page
, order
, gfp_flags
);
2360 if (order
&& (gfp_flags
& __GFP_COMP
))
2361 prep_compound_page(page
, order
);
2364 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2365 * allocate the page. The expectation is that the caller is taking
2366 * steps that will free more memory. The caller should avoid the page
2367 * being used for !PFMEMALLOC purposes.
2369 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2370 set_page_pfmemalloc(page
);
2372 clear_page_pfmemalloc(page
);
2376 * Go through the free lists for the given migratetype and remove
2377 * the smallest available page from the freelists
2379 static __always_inline
2380 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
2383 unsigned int current_order
;
2384 struct free_area
*area
;
2387 /* Find a page of the appropriate size in the preferred list */
2388 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
2389 area
= &(zone
->free_area
[current_order
]);
2390 page
= get_page_from_free_area(area
, migratetype
);
2393 del_page_from_free_list(page
, zone
, current_order
);
2394 expand(zone
, page
, order
, current_order
, migratetype
);
2395 set_pcppage_migratetype(page
, migratetype
);
2404 * This array describes the order lists are fallen back to when
2405 * the free lists for the desirable migrate type are depleted
2407 static int fallbacks
[MIGRATE_TYPES
][3] = {
2408 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2409 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
2410 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2412 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
2414 #ifdef CONFIG_MEMORY_ISOLATION
2415 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
2420 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2423 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
2426 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2427 unsigned int order
) { return NULL
; }
2431 * Move the free pages in a range to the freelist tail of the requested type.
2432 * Note that start_page and end_pages are not aligned on a pageblock
2433 * boundary. If alignment is required, use move_freepages_block()
2435 static int move_freepages(struct zone
*zone
,
2436 unsigned long start_pfn
, unsigned long end_pfn
,
2437 int migratetype
, int *num_movable
)
2442 int pages_moved
= 0;
2444 for (pfn
= start_pfn
; pfn
<= end_pfn
;) {
2445 if (!pfn_valid_within(pfn
)) {
2450 page
= pfn_to_page(pfn
);
2451 if (!PageBuddy(page
)) {
2453 * We assume that pages that could be isolated for
2454 * migration are movable. But we don't actually try
2455 * isolating, as that would be expensive.
2458 (PageLRU(page
) || __PageMovable(page
)))
2464 /* Make sure we are not inadvertently changing nodes */
2465 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
2466 VM_BUG_ON_PAGE(page_zone(page
) != zone
, page
);
2468 order
= buddy_order(page
);
2469 move_to_free_list(page
, zone
, order
, migratetype
);
2471 pages_moved
+= 1 << order
;
2477 int move_freepages_block(struct zone
*zone
, struct page
*page
,
2478 int migratetype
, int *num_movable
)
2480 unsigned long start_pfn
, end_pfn
, pfn
;
2485 pfn
= page_to_pfn(page
);
2486 start_pfn
= pfn
& ~(pageblock_nr_pages
- 1);
2487 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
2489 /* Do not cross zone boundaries */
2490 if (!zone_spans_pfn(zone
, start_pfn
))
2492 if (!zone_spans_pfn(zone
, end_pfn
))
2495 return move_freepages(zone
, start_pfn
, end_pfn
, migratetype
,
2499 static void change_pageblock_range(struct page
*pageblock_page
,
2500 int start_order
, int migratetype
)
2502 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
2504 while (nr_pageblocks
--) {
2505 set_pageblock_migratetype(pageblock_page
, migratetype
);
2506 pageblock_page
+= pageblock_nr_pages
;
2511 * When we are falling back to another migratetype during allocation, try to
2512 * steal extra free pages from the same pageblocks to satisfy further
2513 * allocations, instead of polluting multiple pageblocks.
2515 * If we are stealing a relatively large buddy page, it is likely there will
2516 * be more free pages in the pageblock, so try to steal them all. For
2517 * reclaimable and unmovable allocations, we steal regardless of page size,
2518 * as fragmentation caused by those allocations polluting movable pageblocks
2519 * is worse than movable allocations stealing from unmovable and reclaimable
2522 static bool can_steal_fallback(unsigned int order
, int start_mt
)
2525 * Leaving this order check is intended, although there is
2526 * relaxed order check in next check. The reason is that
2527 * we can actually steal whole pageblock if this condition met,
2528 * but, below check doesn't guarantee it and that is just heuristic
2529 * so could be changed anytime.
2531 if (order
>= pageblock_order
)
2534 if (order
>= pageblock_order
/ 2 ||
2535 start_mt
== MIGRATE_RECLAIMABLE
||
2536 start_mt
== MIGRATE_UNMOVABLE
||
2537 page_group_by_mobility_disabled
)
2543 static inline bool boost_watermark(struct zone
*zone
)
2545 unsigned long max_boost
;
2547 if (!watermark_boost_factor
)
2550 * Don't bother in zones that are unlikely to produce results.
2551 * On small machines, including kdump capture kernels running
2552 * in a small area, boosting the watermark can cause an out of
2553 * memory situation immediately.
2555 if ((pageblock_nr_pages
* 4) > zone_managed_pages(zone
))
2558 max_boost
= mult_frac(zone
->_watermark
[WMARK_HIGH
],
2559 watermark_boost_factor
, 10000);
2562 * high watermark may be uninitialised if fragmentation occurs
2563 * very early in boot so do not boost. We do not fall
2564 * through and boost by pageblock_nr_pages as failing
2565 * allocations that early means that reclaim is not going
2566 * to help and it may even be impossible to reclaim the
2567 * boosted watermark resulting in a hang.
2572 max_boost
= max(pageblock_nr_pages
, max_boost
);
2574 zone
->watermark_boost
= min(zone
->watermark_boost
+ pageblock_nr_pages
,
2581 * This function implements actual steal behaviour. If order is large enough,
2582 * we can steal whole pageblock. If not, we first move freepages in this
2583 * pageblock to our migratetype and determine how many already-allocated pages
2584 * are there in the pageblock with a compatible migratetype. If at least half
2585 * of pages are free or compatible, we can change migratetype of the pageblock
2586 * itself, so pages freed in the future will be put on the correct free list.
2588 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2589 unsigned int alloc_flags
, int start_type
, bool whole_block
)
2591 unsigned int current_order
= buddy_order(page
);
2592 int free_pages
, movable_pages
, alike_pages
;
2595 old_block_type
= get_pageblock_migratetype(page
);
2598 * This can happen due to races and we want to prevent broken
2599 * highatomic accounting.
2601 if (is_migrate_highatomic(old_block_type
))
2604 /* Take ownership for orders >= pageblock_order */
2605 if (current_order
>= pageblock_order
) {
2606 change_pageblock_range(page
, current_order
, start_type
);
2611 * Boost watermarks to increase reclaim pressure to reduce the
2612 * likelihood of future fallbacks. Wake kswapd now as the node
2613 * may be balanced overall and kswapd will not wake naturally.
2615 if (boost_watermark(zone
) && (alloc_flags
& ALLOC_KSWAPD
))
2616 set_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
2618 /* We are not allowed to try stealing from the whole block */
2622 free_pages
= move_freepages_block(zone
, page
, start_type
,
2625 * Determine how many pages are compatible with our allocation.
2626 * For movable allocation, it's the number of movable pages which
2627 * we just obtained. For other types it's a bit more tricky.
2629 if (start_type
== MIGRATE_MOVABLE
) {
2630 alike_pages
= movable_pages
;
2633 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2634 * to MOVABLE pageblock, consider all non-movable pages as
2635 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2636 * vice versa, be conservative since we can't distinguish the
2637 * exact migratetype of non-movable pages.
2639 if (old_block_type
== MIGRATE_MOVABLE
)
2640 alike_pages
= pageblock_nr_pages
2641 - (free_pages
+ movable_pages
);
2646 /* moving whole block can fail due to zone boundary conditions */
2651 * If a sufficient number of pages in the block are either free or of
2652 * comparable migratability as our allocation, claim the whole block.
2654 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2655 page_group_by_mobility_disabled
)
2656 set_pageblock_migratetype(page
, start_type
);
2661 move_to_free_list(page
, zone
, current_order
, start_type
);
2665 * Check whether there is a suitable fallback freepage with requested order.
2666 * If only_stealable is true, this function returns fallback_mt only if
2667 * we can steal other freepages all together. This would help to reduce
2668 * fragmentation due to mixed migratetype pages in one pageblock.
2670 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2671 int migratetype
, bool only_stealable
, bool *can_steal
)
2676 if (area
->nr_free
== 0)
2681 fallback_mt
= fallbacks
[migratetype
][i
];
2682 if (fallback_mt
== MIGRATE_TYPES
)
2685 if (free_area_empty(area
, fallback_mt
))
2688 if (can_steal_fallback(order
, migratetype
))
2691 if (!only_stealable
)
2702 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2703 * there are no empty page blocks that contain a page with a suitable order
2705 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2706 unsigned int alloc_order
)
2709 unsigned long max_managed
, flags
;
2712 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2713 * Check is race-prone but harmless.
2715 max_managed
= (zone_managed_pages(zone
) / 100) + pageblock_nr_pages
;
2716 if (zone
->nr_reserved_highatomic
>= max_managed
)
2719 spin_lock_irqsave(&zone
->lock
, flags
);
2721 /* Recheck the nr_reserved_highatomic limit under the lock */
2722 if (zone
->nr_reserved_highatomic
>= max_managed
)
2726 mt
= get_pageblock_migratetype(page
);
2727 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2728 && !is_migrate_cma(mt
)) {
2729 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2730 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2731 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2735 spin_unlock_irqrestore(&zone
->lock
, flags
);
2739 * Used when an allocation is about to fail under memory pressure. This
2740 * potentially hurts the reliability of high-order allocations when under
2741 * intense memory pressure but failed atomic allocations should be easier
2742 * to recover from than an OOM.
2744 * If @force is true, try to unreserve a pageblock even though highatomic
2745 * pageblock is exhausted.
2747 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2750 struct zonelist
*zonelist
= ac
->zonelist
;
2751 unsigned long flags
;
2758 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->highest_zoneidx
,
2761 * Preserve at least one pageblock unless memory pressure
2764 if (!force
&& zone
->nr_reserved_highatomic
<=
2768 spin_lock_irqsave(&zone
->lock
, flags
);
2769 for (order
= 0; order
< MAX_ORDER
; order
++) {
2770 struct free_area
*area
= &(zone
->free_area
[order
]);
2772 page
= get_page_from_free_area(area
, MIGRATE_HIGHATOMIC
);
2777 * In page freeing path, migratetype change is racy so
2778 * we can counter several free pages in a pageblock
2779 * in this loop althoug we changed the pageblock type
2780 * from highatomic to ac->migratetype. So we should
2781 * adjust the count once.
2783 if (is_migrate_highatomic_page(page
)) {
2785 * It should never happen but changes to
2786 * locking could inadvertently allow a per-cpu
2787 * drain to add pages to MIGRATE_HIGHATOMIC
2788 * while unreserving so be safe and watch for
2791 zone
->nr_reserved_highatomic
-= min(
2793 zone
->nr_reserved_highatomic
);
2797 * Convert to ac->migratetype and avoid the normal
2798 * pageblock stealing heuristics. Minimally, the caller
2799 * is doing the work and needs the pages. More
2800 * importantly, if the block was always converted to
2801 * MIGRATE_UNMOVABLE or another type then the number
2802 * of pageblocks that cannot be completely freed
2805 set_pageblock_migratetype(page
, ac
->migratetype
);
2806 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2809 spin_unlock_irqrestore(&zone
->lock
, flags
);
2813 spin_unlock_irqrestore(&zone
->lock
, flags
);
2820 * Try finding a free buddy page on the fallback list and put it on the free
2821 * list of requested migratetype, possibly along with other pages from the same
2822 * block, depending on fragmentation avoidance heuristics. Returns true if
2823 * fallback was found so that __rmqueue_smallest() can grab it.
2825 * The use of signed ints for order and current_order is a deliberate
2826 * deviation from the rest of this file, to make the for loop
2827 * condition simpler.
2829 static __always_inline
bool
2830 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
,
2831 unsigned int alloc_flags
)
2833 struct free_area
*area
;
2835 int min_order
= order
;
2841 * Do not steal pages from freelists belonging to other pageblocks
2842 * i.e. orders < pageblock_order. If there are no local zones free,
2843 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2845 if (alloc_flags
& ALLOC_NOFRAGMENT
)
2846 min_order
= pageblock_order
;
2849 * Find the largest available free page in the other list. This roughly
2850 * approximates finding the pageblock with the most free pages, which
2851 * would be too costly to do exactly.
2853 for (current_order
= MAX_ORDER
- 1; current_order
>= min_order
;
2855 area
= &(zone
->free_area
[current_order
]);
2856 fallback_mt
= find_suitable_fallback(area
, current_order
,
2857 start_migratetype
, false, &can_steal
);
2858 if (fallback_mt
== -1)
2862 * We cannot steal all free pages from the pageblock and the
2863 * requested migratetype is movable. In that case it's better to
2864 * steal and split the smallest available page instead of the
2865 * largest available page, because even if the next movable
2866 * allocation falls back into a different pageblock than this
2867 * one, it won't cause permanent fragmentation.
2869 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2870 && current_order
> order
)
2879 for (current_order
= order
; current_order
< MAX_ORDER
;
2881 area
= &(zone
->free_area
[current_order
]);
2882 fallback_mt
= find_suitable_fallback(area
, current_order
,
2883 start_migratetype
, false, &can_steal
);
2884 if (fallback_mt
!= -1)
2889 * This should not happen - we already found a suitable fallback
2890 * when looking for the largest page.
2892 VM_BUG_ON(current_order
== MAX_ORDER
);
2895 page
= get_page_from_free_area(area
, fallback_mt
);
2897 steal_suitable_fallback(zone
, page
, alloc_flags
, start_migratetype
,
2900 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2901 start_migratetype
, fallback_mt
);
2908 * Do the hard work of removing an element from the buddy allocator.
2909 * Call me with the zone->lock already held.
2911 static __always_inline
struct page
*
2912 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
,
2913 unsigned int alloc_flags
)
2917 if (IS_ENABLED(CONFIG_CMA
)) {
2919 * Balance movable allocations between regular and CMA areas by
2920 * allocating from CMA when over half of the zone's free memory
2921 * is in the CMA area.
2923 if (alloc_flags
& ALLOC_CMA
&&
2924 zone_page_state(zone
, NR_FREE_CMA_PAGES
) >
2925 zone_page_state(zone
, NR_FREE_PAGES
) / 2) {
2926 page
= __rmqueue_cma_fallback(zone
, order
);
2932 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2933 if (unlikely(!page
)) {
2934 if (alloc_flags
& ALLOC_CMA
)
2935 page
= __rmqueue_cma_fallback(zone
, order
);
2937 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
,
2943 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2948 * Obtain a specified number of elements from the buddy allocator, all under
2949 * a single hold of the lock, for efficiency. Add them to the supplied list.
2950 * Returns the number of new pages which were placed at *list.
2952 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2953 unsigned long count
, struct list_head
*list
,
2954 int migratetype
, unsigned int alloc_flags
)
2956 int i
, allocated
= 0;
2958 spin_lock(&zone
->lock
);
2959 for (i
= 0; i
< count
; ++i
) {
2960 struct page
*page
= __rmqueue(zone
, order
, migratetype
,
2962 if (unlikely(page
== NULL
))
2965 if (unlikely(check_pcp_refill(page
)))
2969 * Split buddy pages returned by expand() are received here in
2970 * physical page order. The page is added to the tail of
2971 * caller's list. From the callers perspective, the linked list
2972 * is ordered by page number under some conditions. This is
2973 * useful for IO devices that can forward direction from the
2974 * head, thus also in the physical page order. This is useful
2975 * for IO devices that can merge IO requests if the physical
2976 * pages are ordered properly.
2978 list_add_tail(&page
->lru
, list
);
2980 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2981 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2986 * i pages were removed from the buddy list even if some leak due
2987 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2988 * on i. Do not confuse with 'allocated' which is the number of
2989 * pages added to the pcp list.
2991 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2992 spin_unlock(&zone
->lock
);
2998 * Called from the vmstat counter updater to drain pagesets of this
2999 * currently executing processor on remote nodes after they have
3002 * Note that this function must be called with the thread pinned to
3003 * a single processor.
3005 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
3007 unsigned long flags
;
3008 int to_drain
, batch
;
3010 local_irq_save(flags
);
3011 batch
= READ_ONCE(pcp
->batch
);
3012 to_drain
= min(pcp
->count
, batch
);
3014 free_pcppages_bulk(zone
, to_drain
, pcp
);
3015 local_irq_restore(flags
);
3020 * Drain pcplists of the indicated processor and zone.
3022 * The processor must either be the current processor and the
3023 * thread pinned to the current processor or a processor that
3026 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
3028 unsigned long flags
;
3029 struct per_cpu_pageset
*pset
;
3030 struct per_cpu_pages
*pcp
;
3032 local_irq_save(flags
);
3033 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3037 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3038 local_irq_restore(flags
);
3042 * Drain pcplists of all zones on the indicated processor.
3044 * The processor must either be the current processor and the
3045 * thread pinned to the current processor or a processor that
3048 static void drain_pages(unsigned int cpu
)
3052 for_each_populated_zone(zone
) {
3053 drain_pages_zone(cpu
, zone
);
3058 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
3060 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
3061 * the single zone's pages.
3063 void drain_local_pages(struct zone
*zone
)
3065 int cpu
= smp_processor_id();
3068 drain_pages_zone(cpu
, zone
);
3073 static void drain_local_pages_wq(struct work_struct
*work
)
3075 struct pcpu_drain
*drain
;
3077 drain
= container_of(work
, struct pcpu_drain
, work
);
3080 * drain_all_pages doesn't use proper cpu hotplug protection so
3081 * we can race with cpu offline when the WQ can move this from
3082 * a cpu pinned worker to an unbound one. We can operate on a different
3083 * cpu which is allright but we also have to make sure to not move to
3087 drain_local_pages(drain
->zone
);
3092 * The implementation of drain_all_pages(), exposing an extra parameter to
3093 * drain on all cpus.
3095 * drain_all_pages() is optimized to only execute on cpus where pcplists are
3096 * not empty. The check for non-emptiness can however race with a free to
3097 * pcplist that has not yet increased the pcp->count from 0 to 1. Callers
3098 * that need the guarantee that every CPU has drained can disable the
3099 * optimizing racy check.
3101 static void __drain_all_pages(struct zone
*zone
, bool force_all_cpus
)
3106 * Allocate in the BSS so we wont require allocation in
3107 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
3109 static cpumask_t cpus_with_pcps
;
3112 * Make sure nobody triggers this path before mm_percpu_wq is fully
3115 if (WARN_ON_ONCE(!mm_percpu_wq
))
3119 * Do not drain if one is already in progress unless it's specific to
3120 * a zone. Such callers are primarily CMA and memory hotplug and need
3121 * the drain to be complete when the call returns.
3123 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
3126 mutex_lock(&pcpu_drain_mutex
);
3130 * We don't care about racing with CPU hotplug event
3131 * as offline notification will cause the notified
3132 * cpu to drain that CPU pcps and on_each_cpu_mask
3133 * disables preemption as part of its processing
3135 for_each_online_cpu(cpu
) {
3136 struct per_cpu_pageset
*pcp
;
3138 bool has_pcps
= false;
3140 if (force_all_cpus
) {
3142 * The pcp.count check is racy, some callers need a
3143 * guarantee that no cpu is missed.
3147 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3151 for_each_populated_zone(z
) {
3152 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
3153 if (pcp
->pcp
.count
) {
3161 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
3163 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
3166 for_each_cpu(cpu
, &cpus_with_pcps
) {
3167 struct pcpu_drain
*drain
= per_cpu_ptr(&pcpu_drain
, cpu
);
3170 INIT_WORK(&drain
->work
, drain_local_pages_wq
);
3171 queue_work_on(cpu
, mm_percpu_wq
, &drain
->work
);
3173 for_each_cpu(cpu
, &cpus_with_pcps
)
3174 flush_work(&per_cpu_ptr(&pcpu_drain
, cpu
)->work
);
3176 mutex_unlock(&pcpu_drain_mutex
);
3180 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
3182 * When zone parameter is non-NULL, spill just the single zone's pages.
3184 * Note that this can be extremely slow as the draining happens in a workqueue.
3186 void drain_all_pages(struct zone
*zone
)
3188 __drain_all_pages(zone
, false);
3191 #ifdef CONFIG_HIBERNATION
3194 * Touch the watchdog for every WD_PAGE_COUNT pages.
3196 #define WD_PAGE_COUNT (128*1024)
3198 void mark_free_pages(struct zone
*zone
)
3200 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
3201 unsigned long flags
;
3202 unsigned int order
, t
;
3205 if (zone_is_empty(zone
))
3208 spin_lock_irqsave(&zone
->lock
, flags
);
3210 max_zone_pfn
= zone_end_pfn(zone
);
3211 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
3212 if (pfn_valid(pfn
)) {
3213 page
= pfn_to_page(pfn
);
3215 if (!--page_count
) {
3216 touch_nmi_watchdog();
3217 page_count
= WD_PAGE_COUNT
;
3220 if (page_zone(page
) != zone
)
3223 if (!swsusp_page_is_forbidden(page
))
3224 swsusp_unset_page_free(page
);
3227 for_each_migratetype_order(order
, t
) {
3228 list_for_each_entry(page
,
3229 &zone
->free_area
[order
].free_list
[t
], lru
) {
3232 pfn
= page_to_pfn(page
);
3233 for (i
= 0; i
< (1UL << order
); i
++) {
3234 if (!--page_count
) {
3235 touch_nmi_watchdog();
3236 page_count
= WD_PAGE_COUNT
;
3238 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
3242 spin_unlock_irqrestore(&zone
->lock
, flags
);
3244 #endif /* CONFIG_PM */
3246 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
3250 if (!free_pcp_prepare(page
))
3253 migratetype
= get_pfnblock_migratetype(page
, pfn
);
3254 set_pcppage_migratetype(page
, migratetype
);
3258 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
3260 struct zone
*zone
= page_zone(page
);
3261 struct per_cpu_pages
*pcp
;
3264 migratetype
= get_pcppage_migratetype(page
);
3265 __count_vm_event(PGFREE
);
3268 * We only track unmovable, reclaimable and movable on pcp lists.
3269 * Free ISOLATE pages back to the allocator because they are being
3270 * offlined but treat HIGHATOMIC as movable pages so we can get those
3271 * areas back if necessary. Otherwise, we may have to free
3272 * excessively into the page allocator
3274 if (migratetype
>= MIGRATE_PCPTYPES
) {
3275 if (unlikely(is_migrate_isolate(migratetype
))) {
3276 free_one_page(zone
, page
, pfn
, 0, migratetype
,
3280 migratetype
= MIGRATE_MOVABLE
;
3283 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3284 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
3286 if (pcp
->count
>= READ_ONCE(pcp
->high
))
3287 free_pcppages_bulk(zone
, READ_ONCE(pcp
->batch
), pcp
);
3291 * Free a 0-order page
3293 void free_unref_page(struct page
*page
)
3295 unsigned long flags
;
3296 unsigned long pfn
= page_to_pfn(page
);
3298 if (!free_unref_page_prepare(page
, pfn
))
3301 local_irq_save(flags
);
3302 free_unref_page_commit(page
, pfn
);
3303 local_irq_restore(flags
);
3307 * Free a list of 0-order pages
3309 void free_unref_page_list(struct list_head
*list
)
3311 struct page
*page
, *next
;
3312 unsigned long flags
, pfn
;
3313 int batch_count
= 0;
3315 /* Prepare pages for freeing */
3316 list_for_each_entry_safe(page
, next
, list
, lru
) {
3317 pfn
= page_to_pfn(page
);
3318 if (!free_unref_page_prepare(page
, pfn
))
3319 list_del(&page
->lru
);
3320 set_page_private(page
, pfn
);
3323 local_irq_save(flags
);
3324 list_for_each_entry_safe(page
, next
, list
, lru
) {
3325 unsigned long pfn
= page_private(page
);
3327 set_page_private(page
, 0);
3328 trace_mm_page_free_batched(page
);
3329 free_unref_page_commit(page
, pfn
);
3332 * Guard against excessive IRQ disabled times when we get
3333 * a large list of pages to free.
3335 if (++batch_count
== SWAP_CLUSTER_MAX
) {
3336 local_irq_restore(flags
);
3338 local_irq_save(flags
);
3341 local_irq_restore(flags
);
3345 * split_page takes a non-compound higher-order page, and splits it into
3346 * n (1<<order) sub-pages: page[0..n]
3347 * Each sub-page must be freed individually.
3349 * Note: this is probably too low level an operation for use in drivers.
3350 * Please consult with lkml before using this in your driver.
3352 void split_page(struct page
*page
, unsigned int order
)
3356 VM_BUG_ON_PAGE(PageCompound(page
), page
);
3357 VM_BUG_ON_PAGE(!page_count(page
), page
);
3359 for (i
= 1; i
< (1 << order
); i
++)
3360 set_page_refcounted(page
+ i
);
3361 split_page_owner(page
, 1 << order
);
3362 split_page_memcg(page
, 1 << order
);
3364 EXPORT_SYMBOL_GPL(split_page
);
3366 int __isolate_free_page(struct page
*page
, unsigned int order
)
3368 unsigned long watermark
;
3372 BUG_ON(!PageBuddy(page
));
3374 zone
= page_zone(page
);
3375 mt
= get_pageblock_migratetype(page
);
3377 if (!is_migrate_isolate(mt
)) {
3379 * Obey watermarks as if the page was being allocated. We can
3380 * emulate a high-order watermark check with a raised order-0
3381 * watermark, because we already know our high-order page
3384 watermark
= zone
->_watermark
[WMARK_MIN
] + (1UL << order
);
3385 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
3388 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
3391 /* Remove page from free list */
3393 del_page_from_free_list(page
, zone
, order
);
3396 * Set the pageblock if the isolated page is at least half of a
3399 if (order
>= pageblock_order
- 1) {
3400 struct page
*endpage
= page
+ (1 << order
) - 1;
3401 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
3402 int mt
= get_pageblock_migratetype(page
);
3403 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
3404 && !is_migrate_highatomic(mt
))
3405 set_pageblock_migratetype(page
,
3411 return 1UL << order
;
3415 * __putback_isolated_page - Return a now-isolated page back where we got it
3416 * @page: Page that was isolated
3417 * @order: Order of the isolated page
3418 * @mt: The page's pageblock's migratetype
3420 * This function is meant to return a page pulled from the free lists via
3421 * __isolate_free_page back to the free lists they were pulled from.
3423 void __putback_isolated_page(struct page
*page
, unsigned int order
, int mt
)
3425 struct zone
*zone
= page_zone(page
);
3427 /* zone lock should be held when this function is called */
3428 lockdep_assert_held(&zone
->lock
);
3430 /* Return isolated page to tail of freelist. */
3431 __free_one_page(page
, page_to_pfn(page
), zone
, order
, mt
,
3432 FPI_SKIP_REPORT_NOTIFY
| FPI_TO_TAIL
);
3436 * Update NUMA hit/miss statistics
3438 * Must be called with interrupts disabled.
3440 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
3443 enum numa_stat_item local_stat
= NUMA_LOCAL
;
3445 /* skip numa counters update if numa stats is disabled */
3446 if (!static_branch_likely(&vm_numa_stat_key
))
3449 if (zone_to_nid(z
) != numa_node_id())
3450 local_stat
= NUMA_OTHER
;
3452 if (zone_to_nid(z
) == zone_to_nid(preferred_zone
))
3453 __inc_numa_state(z
, NUMA_HIT
);
3455 __inc_numa_state(z
, NUMA_MISS
);
3456 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
3458 __inc_numa_state(z
, local_stat
);
3462 /* Remove page from the per-cpu list, caller must protect the list */
3464 struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
3465 unsigned int alloc_flags
,
3466 struct per_cpu_pages
*pcp
,
3467 struct list_head
*list
)
3472 if (list_empty(list
)) {
3473 pcp
->count
+= rmqueue_bulk(zone
, 0,
3474 READ_ONCE(pcp
->batch
), list
,
3475 migratetype
, alloc_flags
);
3476 if (unlikely(list_empty(list
)))
3480 page
= list_first_entry(list
, struct page
, lru
);
3481 list_del(&page
->lru
);
3483 } while (check_new_pcp(page
));
3488 /* Lock and remove page from the per-cpu list */
3489 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
3490 struct zone
*zone
, gfp_t gfp_flags
,
3491 int migratetype
, unsigned int alloc_flags
)
3493 struct per_cpu_pages
*pcp
;
3494 struct list_head
*list
;
3496 unsigned long flags
;
3498 local_irq_save(flags
);
3499 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3500 list
= &pcp
->lists
[migratetype
];
3501 page
= __rmqueue_pcplist(zone
, migratetype
, alloc_flags
, pcp
, list
);
3503 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1);
3504 zone_statistics(preferred_zone
, zone
);
3506 local_irq_restore(flags
);
3511 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3514 struct page
*rmqueue(struct zone
*preferred_zone
,
3515 struct zone
*zone
, unsigned int order
,
3516 gfp_t gfp_flags
, unsigned int alloc_flags
,
3519 unsigned long flags
;
3522 if (likely(order
== 0)) {
3524 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3525 * we need to skip it when CMA area isn't allowed.
3527 if (!IS_ENABLED(CONFIG_CMA
) || alloc_flags
& ALLOC_CMA
||
3528 migratetype
!= MIGRATE_MOVABLE
) {
3529 page
= rmqueue_pcplist(preferred_zone
, zone
, gfp_flags
,
3530 migratetype
, alloc_flags
);
3536 * We most definitely don't want callers attempting to
3537 * allocate greater than order-1 page units with __GFP_NOFAIL.
3539 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
3540 spin_lock_irqsave(&zone
->lock
, flags
);
3545 * order-0 request can reach here when the pcplist is skipped
3546 * due to non-CMA allocation context. HIGHATOMIC area is
3547 * reserved for high-order atomic allocation, so order-0
3548 * request should skip it.
3550 if (order
> 0 && alloc_flags
& ALLOC_HARDER
) {
3551 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
3553 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
3556 page
= __rmqueue(zone
, order
, migratetype
, alloc_flags
);
3557 } while (page
&& check_new_pages(page
, order
));
3558 spin_unlock(&zone
->lock
);
3561 __mod_zone_freepage_state(zone
, -(1 << order
),
3562 get_pcppage_migratetype(page
));
3564 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
3565 zone_statistics(preferred_zone
, zone
);
3566 local_irq_restore(flags
);
3569 /* Separate test+clear to avoid unnecessary atomics */
3570 if (test_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
)) {
3571 clear_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
3572 wakeup_kswapd(zone
, 0, 0, zone_idx(zone
));
3575 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
3579 local_irq_restore(flags
);
3583 #ifdef CONFIG_FAIL_PAGE_ALLOC
3586 struct fault_attr attr
;
3588 bool ignore_gfp_highmem
;
3589 bool ignore_gfp_reclaim
;
3591 } fail_page_alloc
= {
3592 .attr
= FAULT_ATTR_INITIALIZER
,
3593 .ignore_gfp_reclaim
= true,
3594 .ignore_gfp_highmem
= true,
3598 static int __init
setup_fail_page_alloc(char *str
)
3600 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
3602 __setup("fail_page_alloc=", setup_fail_page_alloc
);
3604 static bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3606 if (order
< fail_page_alloc
.min_order
)
3608 if (gfp_mask
& __GFP_NOFAIL
)
3610 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
3612 if (fail_page_alloc
.ignore_gfp_reclaim
&&
3613 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
3616 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
3619 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3621 static int __init
fail_page_alloc_debugfs(void)
3623 umode_t mode
= S_IFREG
| 0600;
3626 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
3627 &fail_page_alloc
.attr
);
3629 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
3630 &fail_page_alloc
.ignore_gfp_reclaim
);
3631 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
3632 &fail_page_alloc
.ignore_gfp_highmem
);
3633 debugfs_create_u32("min-order", mode
, dir
, &fail_page_alloc
.min_order
);
3638 late_initcall(fail_page_alloc_debugfs
);
3640 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3642 #else /* CONFIG_FAIL_PAGE_ALLOC */
3644 static inline bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3649 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3651 noinline
bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3653 return __should_fail_alloc_page(gfp_mask
, order
);
3655 ALLOW_ERROR_INJECTION(should_fail_alloc_page
, TRUE
);
3657 static inline long __zone_watermark_unusable_free(struct zone
*z
,
3658 unsigned int order
, unsigned int alloc_flags
)
3660 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3661 long unusable_free
= (1 << order
) - 1;
3664 * If the caller does not have rights to ALLOC_HARDER then subtract
3665 * the high-atomic reserves. This will over-estimate the size of the
3666 * atomic reserve but it avoids a search.
3668 if (likely(!alloc_harder
))
3669 unusable_free
+= z
->nr_reserved_highatomic
;
3672 /* If allocation can't use CMA areas don't use free CMA pages */
3673 if (!(alloc_flags
& ALLOC_CMA
))
3674 unusable_free
+= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3677 return unusable_free
;
3681 * Return true if free base pages are above 'mark'. For high-order checks it
3682 * will return true of the order-0 watermark is reached and there is at least
3683 * one free page of a suitable size. Checking now avoids taking the zone lock
3684 * to check in the allocation paths if no pages are free.
3686 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3687 int highest_zoneidx
, unsigned int alloc_flags
,
3692 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3694 /* free_pages may go negative - that's OK */
3695 free_pages
-= __zone_watermark_unusable_free(z
, order
, alloc_flags
);
3697 if (alloc_flags
& ALLOC_HIGH
)
3700 if (unlikely(alloc_harder
)) {
3702 * OOM victims can try even harder than normal ALLOC_HARDER
3703 * users on the grounds that it's definitely going to be in
3704 * the exit path shortly and free memory. Any allocation it
3705 * makes during the free path will be small and short-lived.
3707 if (alloc_flags
& ALLOC_OOM
)
3714 * Check watermarks for an order-0 allocation request. If these
3715 * are not met, then a high-order request also cannot go ahead
3716 * even if a suitable page happened to be free.
3718 if (free_pages
<= min
+ z
->lowmem_reserve
[highest_zoneidx
])
3721 /* If this is an order-0 request then the watermark is fine */
3725 /* For a high-order request, check at least one suitable page is free */
3726 for (o
= order
; o
< MAX_ORDER
; o
++) {
3727 struct free_area
*area
= &z
->free_area
[o
];
3733 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3734 if (!free_area_empty(area
, mt
))
3739 if ((alloc_flags
& ALLOC_CMA
) &&
3740 !free_area_empty(area
, MIGRATE_CMA
)) {
3744 if (alloc_harder
&& !free_area_empty(area
, MIGRATE_HIGHATOMIC
))
3750 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3751 int highest_zoneidx
, unsigned int alloc_flags
)
3753 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3754 zone_page_state(z
, NR_FREE_PAGES
));
3757 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3758 unsigned long mark
, int highest_zoneidx
,
3759 unsigned int alloc_flags
, gfp_t gfp_mask
)
3763 free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3766 * Fast check for order-0 only. If this fails then the reserves
3767 * need to be calculated.
3772 fast_free
= free_pages
;
3773 fast_free
-= __zone_watermark_unusable_free(z
, 0, alloc_flags
);
3774 if (fast_free
> mark
+ z
->lowmem_reserve
[highest_zoneidx
])
3778 if (__zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3782 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3783 * when checking the min watermark. The min watermark is the
3784 * point where boosting is ignored so that kswapd is woken up
3785 * when below the low watermark.
3787 if (unlikely(!order
&& (gfp_mask
& __GFP_ATOMIC
) && z
->watermark_boost
3788 && ((alloc_flags
& ALLOC_WMARK_MASK
) == WMARK_MIN
))) {
3789 mark
= z
->_watermark
[WMARK_MIN
];
3790 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
,
3791 alloc_flags
, free_pages
);
3797 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3798 unsigned long mark
, int highest_zoneidx
)
3800 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3802 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3803 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3805 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, 0,
3810 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3812 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3813 node_reclaim_distance
;
3815 #else /* CONFIG_NUMA */
3816 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3820 #endif /* CONFIG_NUMA */
3823 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3824 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3825 * premature use of a lower zone may cause lowmem pressure problems that
3826 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3827 * probably too small. It only makes sense to spread allocations to avoid
3828 * fragmentation between the Normal and DMA32 zones.
3830 static inline unsigned int
3831 alloc_flags_nofragment(struct zone
*zone
, gfp_t gfp_mask
)
3833 unsigned int alloc_flags
;
3836 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3839 alloc_flags
= (__force
int) (gfp_mask
& __GFP_KSWAPD_RECLAIM
);
3841 #ifdef CONFIG_ZONE_DMA32
3845 if (zone_idx(zone
) != ZONE_NORMAL
)
3849 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3850 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3851 * on UMA that if Normal is populated then so is DMA32.
3853 BUILD_BUG_ON(ZONE_NORMAL
- ZONE_DMA32
!= 1);
3854 if (nr_online_nodes
> 1 && !populated_zone(--zone
))
3857 alloc_flags
|= ALLOC_NOFRAGMENT
;
3858 #endif /* CONFIG_ZONE_DMA32 */
3862 static inline unsigned int current_alloc_flags(gfp_t gfp_mask
,
3863 unsigned int alloc_flags
)
3866 unsigned int pflags
= current
->flags
;
3868 if (!(pflags
& PF_MEMALLOC_NOCMA
) &&
3869 gfp_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3870 alloc_flags
|= ALLOC_CMA
;
3877 * get_page_from_freelist goes through the zonelist trying to allocate
3880 static struct page
*
3881 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3882 const struct alloc_context
*ac
)
3886 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3891 * Scan zonelist, looking for a zone with enough free.
3892 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3894 no_fallback
= alloc_flags
& ALLOC_NOFRAGMENT
;
3895 z
= ac
->preferred_zoneref
;
3896 for_next_zone_zonelist_nodemask(zone
, z
, ac
->highest_zoneidx
,
3901 if (cpusets_enabled() &&
3902 (alloc_flags
& ALLOC_CPUSET
) &&
3903 !__cpuset_zone_allowed(zone
, gfp_mask
))
3906 * When allocating a page cache page for writing, we
3907 * want to get it from a node that is within its dirty
3908 * limit, such that no single node holds more than its
3909 * proportional share of globally allowed dirty pages.
3910 * The dirty limits take into account the node's
3911 * lowmem reserves and high watermark so that kswapd
3912 * should be able to balance it without having to
3913 * write pages from its LRU list.
3915 * XXX: For now, allow allocations to potentially
3916 * exceed the per-node dirty limit in the slowpath
3917 * (spread_dirty_pages unset) before going into reclaim,
3918 * which is important when on a NUMA setup the allowed
3919 * nodes are together not big enough to reach the
3920 * global limit. The proper fix for these situations
3921 * will require awareness of nodes in the
3922 * dirty-throttling and the flusher threads.
3924 if (ac
->spread_dirty_pages
) {
3925 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3928 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3929 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3934 if (no_fallback
&& nr_online_nodes
> 1 &&
3935 zone
!= ac
->preferred_zoneref
->zone
) {
3939 * If moving to a remote node, retry but allow
3940 * fragmenting fallbacks. Locality is more important
3941 * than fragmentation avoidance.
3943 local_nid
= zone_to_nid(ac
->preferred_zoneref
->zone
);
3944 if (zone_to_nid(zone
) != local_nid
) {
3945 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3950 mark
= wmark_pages(zone
, alloc_flags
& ALLOC_WMARK_MASK
);
3951 if (!zone_watermark_fast(zone
, order
, mark
,
3952 ac
->highest_zoneidx
, alloc_flags
,
3956 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3958 * Watermark failed for this zone, but see if we can
3959 * grow this zone if it contains deferred pages.
3961 if (static_branch_unlikely(&deferred_pages
)) {
3962 if (_deferred_grow_zone(zone
, order
))
3966 /* Checked here to keep the fast path fast */
3967 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3968 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3971 if (!node_reclaim_enabled() ||
3972 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3975 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3977 case NODE_RECLAIM_NOSCAN
:
3980 case NODE_RECLAIM_FULL
:
3981 /* scanned but unreclaimable */
3984 /* did we reclaim enough */
3985 if (zone_watermark_ok(zone
, order
, mark
,
3986 ac
->highest_zoneidx
, alloc_flags
))
3994 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3995 gfp_mask
, alloc_flags
, ac
->migratetype
);
3997 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
4000 * If this is a high-order atomic allocation then check
4001 * if the pageblock should be reserved for the future
4003 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
4004 reserve_highatomic_pageblock(page
, zone
, order
);
4008 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
4009 /* Try again if zone has deferred pages */
4010 if (static_branch_unlikely(&deferred_pages
)) {
4011 if (_deferred_grow_zone(zone
, order
))
4019 * It's possible on a UMA machine to get through all zones that are
4020 * fragmented. If avoiding fragmentation, reset and try again.
4023 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
4030 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
4032 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
4035 * This documents exceptions given to allocations in certain
4036 * contexts that are allowed to allocate outside current's set
4039 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
4040 if (tsk_is_oom_victim(current
) ||
4041 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
4042 filter
&= ~SHOW_MEM_FILTER_NODES
;
4043 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
4044 filter
&= ~SHOW_MEM_FILTER_NODES
;
4046 show_mem(filter
, nodemask
);
4049 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
4051 struct va_format vaf
;
4053 static DEFINE_RATELIMIT_STATE(nopage_rs
, 10*HZ
, 1);
4055 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
4058 va_start(args
, fmt
);
4061 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
4062 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
4063 nodemask_pr_args(nodemask
));
4066 cpuset_print_current_mems_allowed();
4069 warn_alloc_show_mem(gfp_mask
, nodemask
);
4072 static inline struct page
*
4073 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
4074 unsigned int alloc_flags
,
4075 const struct alloc_context
*ac
)
4079 page
= get_page_from_freelist(gfp_mask
, order
,
4080 alloc_flags
|ALLOC_CPUSET
, ac
);
4082 * fallback to ignore cpuset restriction if our nodes
4086 page
= get_page_from_freelist(gfp_mask
, order
,
4092 static inline struct page
*
4093 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
4094 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
4096 struct oom_control oc
= {
4097 .zonelist
= ac
->zonelist
,
4098 .nodemask
= ac
->nodemask
,
4100 .gfp_mask
= gfp_mask
,
4105 *did_some_progress
= 0;
4108 * Acquire the oom lock. If that fails, somebody else is
4109 * making progress for us.
4111 if (!mutex_trylock(&oom_lock
)) {
4112 *did_some_progress
= 1;
4113 schedule_timeout_uninterruptible(1);
4118 * Go through the zonelist yet one more time, keep very high watermark
4119 * here, this is only to catch a parallel oom killing, we must fail if
4120 * we're still under heavy pressure. But make sure that this reclaim
4121 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
4122 * allocation which will never fail due to oom_lock already held.
4124 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
4125 ~__GFP_DIRECT_RECLAIM
, order
,
4126 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
4130 /* Coredumps can quickly deplete all memory reserves */
4131 if (current
->flags
& PF_DUMPCORE
)
4133 /* The OOM killer will not help higher order allocs */
4134 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4137 * We have already exhausted all our reclaim opportunities without any
4138 * success so it is time to admit defeat. We will skip the OOM killer
4139 * because it is very likely that the caller has a more reasonable
4140 * fallback than shooting a random task.
4142 * The OOM killer may not free memory on a specific node.
4144 if (gfp_mask
& (__GFP_RETRY_MAYFAIL
| __GFP_THISNODE
))
4146 /* The OOM killer does not needlessly kill tasks for lowmem */
4147 if (ac
->highest_zoneidx
< ZONE_NORMAL
)
4149 if (pm_suspended_storage())
4152 * XXX: GFP_NOFS allocations should rather fail than rely on
4153 * other request to make a forward progress.
4154 * We are in an unfortunate situation where out_of_memory cannot
4155 * do much for this context but let's try it to at least get
4156 * access to memory reserved if the current task is killed (see
4157 * out_of_memory). Once filesystems are ready to handle allocation
4158 * failures more gracefully we should just bail out here.
4161 /* Exhausted what can be done so it's blame time */
4162 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
4163 *did_some_progress
= 1;
4166 * Help non-failing allocations by giving them access to memory
4169 if (gfp_mask
& __GFP_NOFAIL
)
4170 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
4171 ALLOC_NO_WATERMARKS
, ac
);
4174 mutex_unlock(&oom_lock
);
4179 * Maximum number of compaction retries wit a progress before OOM
4180 * killer is consider as the only way to move forward.
4182 #define MAX_COMPACT_RETRIES 16
4184 #ifdef CONFIG_COMPACTION
4185 /* Try memory compaction for high-order allocations before reclaim */
4186 static struct page
*
4187 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4188 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4189 enum compact_priority prio
, enum compact_result
*compact_result
)
4191 struct page
*page
= NULL
;
4192 unsigned long pflags
;
4193 unsigned int noreclaim_flag
;
4198 psi_memstall_enter(&pflags
);
4199 noreclaim_flag
= memalloc_noreclaim_save();
4201 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
4204 memalloc_noreclaim_restore(noreclaim_flag
);
4205 psi_memstall_leave(&pflags
);
4207 if (*compact_result
== COMPACT_SKIPPED
)
4210 * At least in one zone compaction wasn't deferred or skipped, so let's
4211 * count a compaction stall
4213 count_vm_event(COMPACTSTALL
);
4215 /* Prep a captured page if available */
4217 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
4219 /* Try get a page from the freelist if available */
4221 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4224 struct zone
*zone
= page_zone(page
);
4226 zone
->compact_blockskip_flush
= false;
4227 compaction_defer_reset(zone
, order
, true);
4228 count_vm_event(COMPACTSUCCESS
);
4233 * It's bad if compaction run occurs and fails. The most likely reason
4234 * is that pages exist, but not enough to satisfy watermarks.
4236 count_vm_event(COMPACTFAIL
);
4244 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
4245 enum compact_result compact_result
,
4246 enum compact_priority
*compact_priority
,
4247 int *compaction_retries
)
4249 int max_retries
= MAX_COMPACT_RETRIES
;
4252 int retries
= *compaction_retries
;
4253 enum compact_priority priority
= *compact_priority
;
4258 if (compaction_made_progress(compact_result
))
4259 (*compaction_retries
)++;
4262 * compaction considers all the zone as desperately out of memory
4263 * so it doesn't really make much sense to retry except when the
4264 * failure could be caused by insufficient priority
4266 if (compaction_failed(compact_result
))
4267 goto check_priority
;
4270 * compaction was skipped because there are not enough order-0 pages
4271 * to work with, so we retry only if it looks like reclaim can help.
4273 if (compaction_needs_reclaim(compact_result
)) {
4274 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
4279 * make sure the compaction wasn't deferred or didn't bail out early
4280 * due to locks contention before we declare that we should give up.
4281 * But the next retry should use a higher priority if allowed, so
4282 * we don't just keep bailing out endlessly.
4284 if (compaction_withdrawn(compact_result
)) {
4285 goto check_priority
;
4289 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4290 * costly ones because they are de facto nofail and invoke OOM
4291 * killer to move on while costly can fail and users are ready
4292 * to cope with that. 1/4 retries is rather arbitrary but we
4293 * would need much more detailed feedback from compaction to
4294 * make a better decision.
4296 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4298 if (*compaction_retries
<= max_retries
) {
4304 * Make sure there are attempts at the highest priority if we exhausted
4305 * all retries or failed at the lower priorities.
4308 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
4309 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
4311 if (*compact_priority
> min_priority
) {
4312 (*compact_priority
)--;
4313 *compaction_retries
= 0;
4317 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
4321 static inline struct page
*
4322 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4323 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4324 enum compact_priority prio
, enum compact_result
*compact_result
)
4326 *compact_result
= COMPACT_SKIPPED
;
4331 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
4332 enum compact_result compact_result
,
4333 enum compact_priority
*compact_priority
,
4334 int *compaction_retries
)
4339 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
4343 * There are setups with compaction disabled which would prefer to loop
4344 * inside the allocator rather than hit the oom killer prematurely.
4345 * Let's give them a good hope and keep retrying while the order-0
4346 * watermarks are OK.
4348 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4349 ac
->highest_zoneidx
, ac
->nodemask
) {
4350 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
4351 ac
->highest_zoneidx
, alloc_flags
))
4356 #endif /* CONFIG_COMPACTION */
4358 #ifdef CONFIG_LOCKDEP
4359 static struct lockdep_map __fs_reclaim_map
=
4360 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
4362 static bool __need_reclaim(gfp_t gfp_mask
)
4364 /* no reclaim without waiting on it */
4365 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
4368 /* this guy won't enter reclaim */
4369 if (current
->flags
& PF_MEMALLOC
)
4372 if (gfp_mask
& __GFP_NOLOCKDEP
)
4378 void __fs_reclaim_acquire(void)
4380 lock_map_acquire(&__fs_reclaim_map
);
4383 void __fs_reclaim_release(void)
4385 lock_map_release(&__fs_reclaim_map
);
4388 void fs_reclaim_acquire(gfp_t gfp_mask
)
4390 gfp_mask
= current_gfp_context(gfp_mask
);
4392 if (__need_reclaim(gfp_mask
)) {
4393 if (gfp_mask
& __GFP_FS
)
4394 __fs_reclaim_acquire();
4396 #ifdef CONFIG_MMU_NOTIFIER
4397 lock_map_acquire(&__mmu_notifier_invalidate_range_start_map
);
4398 lock_map_release(&__mmu_notifier_invalidate_range_start_map
);
4403 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
4405 void fs_reclaim_release(gfp_t gfp_mask
)
4407 gfp_mask
= current_gfp_context(gfp_mask
);
4409 if (__need_reclaim(gfp_mask
)) {
4410 if (gfp_mask
& __GFP_FS
)
4411 __fs_reclaim_release();
4414 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
4417 /* Perform direct synchronous page reclaim */
4418 static unsigned long
4419 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
4420 const struct alloc_context
*ac
)
4422 unsigned int noreclaim_flag
;
4423 unsigned long pflags
, progress
;
4427 /* We now go into synchronous reclaim */
4428 cpuset_memory_pressure_bump();
4429 psi_memstall_enter(&pflags
);
4430 fs_reclaim_acquire(gfp_mask
);
4431 noreclaim_flag
= memalloc_noreclaim_save();
4433 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
4436 memalloc_noreclaim_restore(noreclaim_flag
);
4437 fs_reclaim_release(gfp_mask
);
4438 psi_memstall_leave(&pflags
);
4445 /* The really slow allocator path where we enter direct reclaim */
4446 static inline struct page
*
4447 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
4448 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4449 unsigned long *did_some_progress
)
4451 struct page
*page
= NULL
;
4452 bool drained
= false;
4454 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
4455 if (unlikely(!(*did_some_progress
)))
4459 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4462 * If an allocation failed after direct reclaim, it could be because
4463 * pages are pinned on the per-cpu lists or in high alloc reserves.
4464 * Shrink them and try again
4466 if (!page
&& !drained
) {
4467 unreserve_highatomic_pageblock(ac
, false);
4468 drain_all_pages(NULL
);
4476 static void wake_all_kswapds(unsigned int order
, gfp_t gfp_mask
,
4477 const struct alloc_context
*ac
)
4481 pg_data_t
*last_pgdat
= NULL
;
4482 enum zone_type highest_zoneidx
= ac
->highest_zoneidx
;
4484 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, highest_zoneidx
,
4486 if (last_pgdat
!= zone
->zone_pgdat
)
4487 wakeup_kswapd(zone
, gfp_mask
, order
, highest_zoneidx
);
4488 last_pgdat
= zone
->zone_pgdat
;
4492 static inline unsigned int
4493 gfp_to_alloc_flags(gfp_t gfp_mask
)
4495 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
4498 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4499 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4500 * to save two branches.
4502 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
4503 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM
!= (__force gfp_t
) ALLOC_KSWAPD
);
4506 * The caller may dip into page reserves a bit more if the caller
4507 * cannot run direct reclaim, or if the caller has realtime scheduling
4508 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4509 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4511 alloc_flags
|= (__force
int)
4512 (gfp_mask
& (__GFP_HIGH
| __GFP_KSWAPD_RECLAIM
));
4514 if (gfp_mask
& __GFP_ATOMIC
) {
4516 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4517 * if it can't schedule.
4519 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
4520 alloc_flags
|= ALLOC_HARDER
;
4522 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4523 * comment for __cpuset_node_allowed().
4525 alloc_flags
&= ~ALLOC_CPUSET
;
4526 } else if (unlikely(rt_task(current
)) && !in_interrupt())
4527 alloc_flags
|= ALLOC_HARDER
;
4529 alloc_flags
= current_alloc_flags(gfp_mask
, alloc_flags
);
4534 static bool oom_reserves_allowed(struct task_struct
*tsk
)
4536 if (!tsk_is_oom_victim(tsk
))
4540 * !MMU doesn't have oom reaper so give access to memory reserves
4541 * only to the thread with TIF_MEMDIE set
4543 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
4550 * Distinguish requests which really need access to full memory
4551 * reserves from oom victims which can live with a portion of it
4553 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
4555 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
4557 if (gfp_mask
& __GFP_MEMALLOC
)
4558 return ALLOC_NO_WATERMARKS
;
4559 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
4560 return ALLOC_NO_WATERMARKS
;
4561 if (!in_interrupt()) {
4562 if (current
->flags
& PF_MEMALLOC
)
4563 return ALLOC_NO_WATERMARKS
;
4564 else if (oom_reserves_allowed(current
))
4571 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
4573 return !!__gfp_pfmemalloc_flags(gfp_mask
);
4577 * Checks whether it makes sense to retry the reclaim to make a forward progress
4578 * for the given allocation request.
4580 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4581 * without success, or when we couldn't even meet the watermark if we
4582 * reclaimed all remaining pages on the LRU lists.
4584 * Returns true if a retry is viable or false to enter the oom path.
4587 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
4588 struct alloc_context
*ac
, int alloc_flags
,
4589 bool did_some_progress
, int *no_progress_loops
)
4596 * Costly allocations might have made a progress but this doesn't mean
4597 * their order will become available due to high fragmentation so
4598 * always increment the no progress counter for them
4600 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
4601 *no_progress_loops
= 0;
4603 (*no_progress_loops
)++;
4606 * Make sure we converge to OOM if we cannot make any progress
4607 * several times in the row.
4609 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
4610 /* Before OOM, exhaust highatomic_reserve */
4611 return unreserve_highatomic_pageblock(ac
, true);
4615 * Keep reclaiming pages while there is a chance this will lead
4616 * somewhere. If none of the target zones can satisfy our allocation
4617 * request even if all reclaimable pages are considered then we are
4618 * screwed and have to go OOM.
4620 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4621 ac
->highest_zoneidx
, ac
->nodemask
) {
4622 unsigned long available
;
4623 unsigned long reclaimable
;
4624 unsigned long min_wmark
= min_wmark_pages(zone
);
4627 available
= reclaimable
= zone_reclaimable_pages(zone
);
4628 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
4631 * Would the allocation succeed if we reclaimed all
4632 * reclaimable pages?
4634 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
4635 ac
->highest_zoneidx
, alloc_flags
, available
);
4636 trace_reclaim_retry_zone(z
, order
, reclaimable
,
4637 available
, min_wmark
, *no_progress_loops
, wmark
);
4640 * If we didn't make any progress and have a lot of
4641 * dirty + writeback pages then we should wait for
4642 * an IO to complete to slow down the reclaim and
4643 * prevent from pre mature OOM
4645 if (!did_some_progress
) {
4646 unsigned long write_pending
;
4648 write_pending
= zone_page_state_snapshot(zone
,
4649 NR_ZONE_WRITE_PENDING
);
4651 if (2 * write_pending
> reclaimable
) {
4652 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4664 * Memory allocation/reclaim might be called from a WQ context and the
4665 * current implementation of the WQ concurrency control doesn't
4666 * recognize that a particular WQ is congested if the worker thread is
4667 * looping without ever sleeping. Therefore we have to do a short sleep
4668 * here rather than calling cond_resched().
4670 if (current
->flags
& PF_WQ_WORKER
)
4671 schedule_timeout_uninterruptible(1);
4678 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
4681 * It's possible that cpuset's mems_allowed and the nodemask from
4682 * mempolicy don't intersect. This should be normally dealt with by
4683 * policy_nodemask(), but it's possible to race with cpuset update in
4684 * such a way the check therein was true, and then it became false
4685 * before we got our cpuset_mems_cookie here.
4686 * This assumes that for all allocations, ac->nodemask can come only
4687 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4688 * when it does not intersect with the cpuset restrictions) or the
4689 * caller can deal with a violated nodemask.
4691 if (cpusets_enabled() && ac
->nodemask
&&
4692 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
4693 ac
->nodemask
= NULL
;
4698 * When updating a task's mems_allowed or mempolicy nodemask, it is
4699 * possible to race with parallel threads in such a way that our
4700 * allocation can fail while the mask is being updated. If we are about
4701 * to fail, check if the cpuset changed during allocation and if so,
4704 if (read_mems_allowed_retry(cpuset_mems_cookie
))
4710 static inline struct page
*
4711 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
4712 struct alloc_context
*ac
)
4714 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
4715 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
4716 struct page
*page
= NULL
;
4717 unsigned int alloc_flags
;
4718 unsigned long did_some_progress
;
4719 enum compact_priority compact_priority
;
4720 enum compact_result compact_result
;
4721 int compaction_retries
;
4722 int no_progress_loops
;
4723 unsigned int cpuset_mems_cookie
;
4727 * We also sanity check to catch abuse of atomic reserves being used by
4728 * callers that are not in atomic context.
4730 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
4731 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
4732 gfp_mask
&= ~__GFP_ATOMIC
;
4735 compaction_retries
= 0;
4736 no_progress_loops
= 0;
4737 compact_priority
= DEF_COMPACT_PRIORITY
;
4738 cpuset_mems_cookie
= read_mems_allowed_begin();
4741 * The fast path uses conservative alloc_flags to succeed only until
4742 * kswapd needs to be woken up, and to avoid the cost of setting up
4743 * alloc_flags precisely. So we do that now.
4745 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
4748 * We need to recalculate the starting point for the zonelist iterator
4749 * because we might have used different nodemask in the fast path, or
4750 * there was a cpuset modification and we are retrying - otherwise we
4751 * could end up iterating over non-eligible zones endlessly.
4753 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4754 ac
->highest_zoneidx
, ac
->nodemask
);
4755 if (!ac
->preferred_zoneref
->zone
)
4758 if (alloc_flags
& ALLOC_KSWAPD
)
4759 wake_all_kswapds(order
, gfp_mask
, ac
);
4762 * The adjusted alloc_flags might result in immediate success, so try
4765 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4770 * For costly allocations, try direct compaction first, as it's likely
4771 * that we have enough base pages and don't need to reclaim. For non-
4772 * movable high-order allocations, do that as well, as compaction will
4773 * try prevent permanent fragmentation by migrating from blocks of the
4775 * Don't try this for allocations that are allowed to ignore
4776 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4778 if (can_direct_reclaim
&&
4780 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
4781 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
4782 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
4784 INIT_COMPACT_PRIORITY
,
4790 * Checks for costly allocations with __GFP_NORETRY, which
4791 * includes some THP page fault allocations
4793 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
4795 * If allocating entire pageblock(s) and compaction
4796 * failed because all zones are below low watermarks
4797 * or is prohibited because it recently failed at this
4798 * order, fail immediately unless the allocator has
4799 * requested compaction and reclaim retry.
4802 * - potentially very expensive because zones are far
4803 * below their low watermarks or this is part of very
4804 * bursty high order allocations,
4805 * - not guaranteed to help because isolate_freepages()
4806 * may not iterate over freed pages as part of its
4808 * - unlikely to make entire pageblocks free on its
4811 if (compact_result
== COMPACT_SKIPPED
||
4812 compact_result
== COMPACT_DEFERRED
)
4816 * Looks like reclaim/compaction is worth trying, but
4817 * sync compaction could be very expensive, so keep
4818 * using async compaction.
4820 compact_priority
= INIT_COMPACT_PRIORITY
;
4825 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4826 if (alloc_flags
& ALLOC_KSWAPD
)
4827 wake_all_kswapds(order
, gfp_mask
, ac
);
4829 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4831 alloc_flags
= current_alloc_flags(gfp_mask
, reserve_flags
);
4834 * Reset the nodemask and zonelist iterators if memory policies can be
4835 * ignored. These allocations are high priority and system rather than
4838 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4839 ac
->nodemask
= NULL
;
4840 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4841 ac
->highest_zoneidx
, ac
->nodemask
);
4844 /* Attempt with potentially adjusted zonelist and alloc_flags */
4845 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4849 /* Caller is not willing to reclaim, we can't balance anything */
4850 if (!can_direct_reclaim
)
4853 /* Avoid recursion of direct reclaim */
4854 if (current
->flags
& PF_MEMALLOC
)
4857 /* Try direct reclaim and then allocating */
4858 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4859 &did_some_progress
);
4863 /* Try direct compaction and then allocating */
4864 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4865 compact_priority
, &compact_result
);
4869 /* Do not loop if specifically requested */
4870 if (gfp_mask
& __GFP_NORETRY
)
4874 * Do not retry costly high order allocations unless they are
4875 * __GFP_RETRY_MAYFAIL
4877 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4880 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4881 did_some_progress
> 0, &no_progress_loops
))
4885 * It doesn't make any sense to retry for the compaction if the order-0
4886 * reclaim is not able to make any progress because the current
4887 * implementation of the compaction depends on the sufficient amount
4888 * of free memory (see __compaction_suitable)
4890 if (did_some_progress
> 0 &&
4891 should_compact_retry(ac
, order
, alloc_flags
,
4892 compact_result
, &compact_priority
,
4893 &compaction_retries
))
4897 /* Deal with possible cpuset update races before we start OOM killing */
4898 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4901 /* Reclaim has failed us, start killing things */
4902 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4906 /* Avoid allocations with no watermarks from looping endlessly */
4907 if (tsk_is_oom_victim(current
) &&
4908 (alloc_flags
& ALLOC_OOM
||
4909 (gfp_mask
& __GFP_NOMEMALLOC
)))
4912 /* Retry as long as the OOM killer is making progress */
4913 if (did_some_progress
) {
4914 no_progress_loops
= 0;
4919 /* Deal with possible cpuset update races before we fail */
4920 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4924 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4927 if (gfp_mask
& __GFP_NOFAIL
) {
4929 * All existing users of the __GFP_NOFAIL are blockable, so warn
4930 * of any new users that actually require GFP_NOWAIT
4932 if (WARN_ON_ONCE(!can_direct_reclaim
))
4936 * PF_MEMALLOC request from this context is rather bizarre
4937 * because we cannot reclaim anything and only can loop waiting
4938 * for somebody to do a work for us
4940 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4943 * non failing costly orders are a hard requirement which we
4944 * are not prepared for much so let's warn about these users
4945 * so that we can identify them and convert them to something
4948 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4951 * Help non-failing allocations by giving them access to memory
4952 * reserves but do not use ALLOC_NO_WATERMARKS because this
4953 * could deplete whole memory reserves which would just make
4954 * the situation worse
4956 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4964 warn_alloc(gfp_mask
, ac
->nodemask
,
4965 "page allocation failure: order:%u", order
);
4970 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4971 int preferred_nid
, nodemask_t
*nodemask
,
4972 struct alloc_context
*ac
, gfp_t
*alloc_gfp
,
4973 unsigned int *alloc_flags
)
4975 ac
->highest_zoneidx
= gfp_zone(gfp_mask
);
4976 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4977 ac
->nodemask
= nodemask
;
4978 ac
->migratetype
= gfp_migratetype(gfp_mask
);
4980 if (cpusets_enabled()) {
4981 *alloc_gfp
|= __GFP_HARDWALL
;
4983 * When we are in the interrupt context, it is irrelevant
4984 * to the current task context. It means that any node ok.
4986 if (!in_interrupt() && !ac
->nodemask
)
4987 ac
->nodemask
= &cpuset_current_mems_allowed
;
4989 *alloc_flags
|= ALLOC_CPUSET
;
4992 fs_reclaim_acquire(gfp_mask
);
4993 fs_reclaim_release(gfp_mask
);
4995 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4997 if (should_fail_alloc_page(gfp_mask
, order
))
5000 *alloc_flags
= current_alloc_flags(gfp_mask
, *alloc_flags
);
5002 /* Dirty zone balancing only done in the fast path */
5003 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
5006 * The preferred zone is used for statistics but crucially it is
5007 * also used as the starting point for the zonelist iterator. It
5008 * may get reset for allocations that ignore memory policies.
5010 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
5011 ac
->highest_zoneidx
, ac
->nodemask
);
5017 * __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array
5018 * @gfp: GFP flags for the allocation
5019 * @preferred_nid: The preferred NUMA node ID to allocate from
5020 * @nodemask: Set of nodes to allocate from, may be NULL
5021 * @nr_pages: The number of pages desired on the list or array
5022 * @page_list: Optional list to store the allocated pages
5023 * @page_array: Optional array to store the pages
5025 * This is a batched version of the page allocator that attempts to
5026 * allocate nr_pages quickly. Pages are added to page_list if page_list
5027 * is not NULL, otherwise it is assumed that the page_array is valid.
5029 * For lists, nr_pages is the number of pages that should be allocated.
5031 * For arrays, only NULL elements are populated with pages and nr_pages
5032 * is the maximum number of pages that will be stored in the array.
5034 * Returns the number of pages on the list or array.
5036 unsigned long __alloc_pages_bulk(gfp_t gfp
, int preferred_nid
,
5037 nodemask_t
*nodemask
, int nr_pages
,
5038 struct list_head
*page_list
,
5039 struct page
**page_array
)
5042 unsigned long flags
;
5045 struct per_cpu_pages
*pcp
;
5046 struct list_head
*pcp_list
;
5047 struct alloc_context ac
;
5049 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
5050 int nr_populated
= 0;
5052 if (unlikely(nr_pages
<= 0))
5056 * Skip populated array elements to determine if any pages need
5057 * to be allocated before disabling IRQs.
5059 while (page_array
&& page_array
[nr_populated
] && nr_populated
< nr_pages
)
5062 /* Use the single page allocator for one page. */
5063 if (nr_pages
- nr_populated
== 1)
5066 /* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */
5067 gfp
&= gfp_allowed_mask
;
5069 if (!prepare_alloc_pages(gfp
, 0, preferred_nid
, nodemask
, &ac
, &alloc_gfp
, &alloc_flags
))
5073 /* Find an allowed local zone that meets the low watermark. */
5074 for_each_zone_zonelist_nodemask(zone
, z
, ac
.zonelist
, ac
.highest_zoneidx
, ac
.nodemask
) {
5077 if (cpusets_enabled() && (alloc_flags
& ALLOC_CPUSET
) &&
5078 !__cpuset_zone_allowed(zone
, gfp
)) {
5082 if (nr_online_nodes
> 1 && zone
!= ac
.preferred_zoneref
->zone
&&
5083 zone_to_nid(zone
) != zone_to_nid(ac
.preferred_zoneref
->zone
)) {
5087 mark
= wmark_pages(zone
, alloc_flags
& ALLOC_WMARK_MASK
) + nr_pages
;
5088 if (zone_watermark_fast(zone
, 0, mark
,
5089 zonelist_zone_idx(ac
.preferred_zoneref
),
5090 alloc_flags
, gfp
)) {
5096 * If there are no allowed local zones that meets the watermarks then
5097 * try to allocate a single page and reclaim if necessary.
5099 if (unlikely(!zone
))
5102 /* Attempt the batch allocation */
5103 local_irq_save(flags
);
5104 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
5105 pcp_list
= &pcp
->lists
[ac
.migratetype
];
5107 while (nr_populated
< nr_pages
) {
5109 /* Skip existing pages */
5110 if (page_array
&& page_array
[nr_populated
]) {
5115 page
= __rmqueue_pcplist(zone
, ac
.migratetype
, alloc_flags
,
5117 if (unlikely(!page
)) {
5118 /* Try and get at least one page */
5125 * Ideally this would be batched but the best way to do
5126 * that cheaply is to first convert zone_statistics to
5127 * be inaccurate per-cpu counter like vm_events to avoid
5128 * a RMW cycle then do the accounting with IRQs enabled.
5130 __count_zid_vm_events(PGALLOC
, zone_idx(zone
), 1);
5131 zone_statistics(ac
.preferred_zoneref
->zone
, zone
);
5133 prep_new_page(page
, 0, gfp
, 0);
5135 list_add(&page
->lru
, page_list
);
5137 page_array
[nr_populated
] = page
;
5141 local_irq_restore(flags
);
5143 return nr_populated
;
5146 local_irq_restore(flags
);
5149 page
= __alloc_pages(gfp
, 0, preferred_nid
, nodemask
);
5152 list_add(&page
->lru
, page_list
);
5154 page_array
[nr_populated
] = page
;
5158 return nr_populated
;
5160 EXPORT_SYMBOL_GPL(__alloc_pages_bulk
);
5163 * This is the 'heart' of the zoned buddy allocator.
5165 struct page
*__alloc_pages(gfp_t gfp
, unsigned int order
, int preferred_nid
,
5166 nodemask_t
*nodemask
)
5169 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
5170 gfp_t alloc_gfp
; /* The gfp_t that was actually used for allocation */
5171 struct alloc_context ac
= { };
5174 * There are several places where we assume that the order value is sane
5175 * so bail out early if the request is out of bound.
5177 if (unlikely(order
>= MAX_ORDER
)) {
5178 WARN_ON_ONCE(!(gfp
& __GFP_NOWARN
));
5182 gfp
&= gfp_allowed_mask
;
5184 if (!prepare_alloc_pages(gfp
, order
, preferred_nid
, nodemask
, &ac
,
5185 &alloc_gfp
, &alloc_flags
))
5189 * Forbid the first pass from falling back to types that fragment
5190 * memory until all local zones are considered.
5192 alloc_flags
|= alloc_flags_nofragment(ac
.preferred_zoneref
->zone
, gfp
);
5194 /* First allocation attempt */
5195 page
= get_page_from_freelist(alloc_gfp
, order
, alloc_flags
, &ac
);
5200 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
5201 * resp. GFP_NOIO which has to be inherited for all allocation requests
5202 * from a particular context which has been marked by
5203 * memalloc_no{fs,io}_{save,restore}.
5205 alloc_gfp
= current_gfp_context(gfp
);
5206 ac
.spread_dirty_pages
= false;
5209 * Restore the original nodemask if it was potentially replaced with
5210 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
5212 ac
.nodemask
= nodemask
;
5214 page
= __alloc_pages_slowpath(alloc_gfp
, order
, &ac
);
5217 if (memcg_kmem_enabled() && (gfp
& __GFP_ACCOUNT
) && page
&&
5218 unlikely(__memcg_kmem_charge_page(page
, gfp
, order
) != 0)) {
5219 __free_pages(page
, order
);
5223 trace_mm_page_alloc(page
, order
, alloc_gfp
, ac
.migratetype
);
5227 EXPORT_SYMBOL(__alloc_pages
);
5230 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
5231 * address cannot represent highmem pages. Use alloc_pages and then kmap if
5232 * you need to access high mem.
5234 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
5238 page
= alloc_pages(gfp_mask
& ~__GFP_HIGHMEM
, order
);
5241 return (unsigned long) page_address(page
);
5243 EXPORT_SYMBOL(__get_free_pages
);
5245 unsigned long get_zeroed_page(gfp_t gfp_mask
)
5247 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
5249 EXPORT_SYMBOL(get_zeroed_page
);
5251 static inline void free_the_page(struct page
*page
, unsigned int order
)
5253 if (order
== 0) /* Via pcp? */
5254 free_unref_page(page
);
5256 __free_pages_ok(page
, order
, FPI_NONE
);
5260 * __free_pages - Free pages allocated with alloc_pages().
5261 * @page: The page pointer returned from alloc_pages().
5262 * @order: The order of the allocation.
5264 * This function can free multi-page allocations that are not compound
5265 * pages. It does not check that the @order passed in matches that of
5266 * the allocation, so it is easy to leak memory. Freeing more memory
5267 * than was allocated will probably emit a warning.
5269 * If the last reference to this page is speculative, it will be released
5270 * by put_page() which only frees the first page of a non-compound
5271 * allocation. To prevent the remaining pages from being leaked, we free
5272 * the subsequent pages here. If you want to use the page's reference
5273 * count to decide when to free the allocation, you should allocate a
5274 * compound page, and use put_page() instead of __free_pages().
5276 * Context: May be called in interrupt context or while holding a normal
5277 * spinlock, but not in NMI context or while holding a raw spinlock.
5279 void __free_pages(struct page
*page
, unsigned int order
)
5281 if (put_page_testzero(page
))
5282 free_the_page(page
, order
);
5283 else if (!PageHead(page
))
5285 free_the_page(page
+ (1 << order
), order
);
5287 EXPORT_SYMBOL(__free_pages
);
5289 void free_pages(unsigned long addr
, unsigned int order
)
5292 VM_BUG_ON(!virt_addr_valid((void *)addr
));
5293 __free_pages(virt_to_page((void *)addr
), order
);
5297 EXPORT_SYMBOL(free_pages
);
5301 * An arbitrary-length arbitrary-offset area of memory which resides
5302 * within a 0 or higher order page. Multiple fragments within that page
5303 * are individually refcounted, in the page's reference counter.
5305 * The page_frag functions below provide a simple allocation framework for
5306 * page fragments. This is used by the network stack and network device
5307 * drivers to provide a backing region of memory for use as either an
5308 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
5310 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
5313 struct page
*page
= NULL
;
5314 gfp_t gfp
= gfp_mask
;
5316 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5317 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
5319 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
5320 PAGE_FRAG_CACHE_MAX_ORDER
);
5321 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
5323 if (unlikely(!page
))
5324 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
5326 nc
->va
= page
? page_address(page
) : NULL
;
5331 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
5333 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
5335 if (page_ref_sub_and_test(page
, count
))
5336 free_the_page(page
, compound_order(page
));
5338 EXPORT_SYMBOL(__page_frag_cache_drain
);
5340 void *page_frag_alloc_align(struct page_frag_cache
*nc
,
5341 unsigned int fragsz
, gfp_t gfp_mask
,
5342 unsigned int align_mask
)
5344 unsigned int size
= PAGE_SIZE
;
5348 if (unlikely(!nc
->va
)) {
5350 page
= __page_frag_cache_refill(nc
, gfp_mask
);
5354 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5355 /* if size can vary use size else just use PAGE_SIZE */
5358 /* Even if we own the page, we do not use atomic_set().
5359 * This would break get_page_unless_zero() users.
5361 page_ref_add(page
, PAGE_FRAG_CACHE_MAX_SIZE
);
5363 /* reset page count bias and offset to start of new frag */
5364 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
5365 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5369 offset
= nc
->offset
- fragsz
;
5370 if (unlikely(offset
< 0)) {
5371 page
= virt_to_page(nc
->va
);
5373 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
5376 if (unlikely(nc
->pfmemalloc
)) {
5377 free_the_page(page
, compound_order(page
));
5381 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5382 /* if size can vary use size else just use PAGE_SIZE */
5385 /* OK, page count is 0, we can safely set it */
5386 set_page_count(page
, PAGE_FRAG_CACHE_MAX_SIZE
+ 1);
5388 /* reset page count bias and offset to start of new frag */
5389 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5390 offset
= size
- fragsz
;
5394 offset
&= align_mask
;
5395 nc
->offset
= offset
;
5397 return nc
->va
+ offset
;
5399 EXPORT_SYMBOL(page_frag_alloc_align
);
5402 * Frees a page fragment allocated out of either a compound or order 0 page.
5404 void page_frag_free(void *addr
)
5406 struct page
*page
= virt_to_head_page(addr
);
5408 if (unlikely(put_page_testzero(page
)))
5409 free_the_page(page
, compound_order(page
));
5411 EXPORT_SYMBOL(page_frag_free
);
5413 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
5417 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
5418 unsigned long used
= addr
+ PAGE_ALIGN(size
);
5420 split_page(virt_to_page((void *)addr
), order
);
5421 while (used
< alloc_end
) {
5426 return (void *)addr
;
5430 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5431 * @size: the number of bytes to allocate
5432 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5434 * This function is similar to alloc_pages(), except that it allocates the
5435 * minimum number of pages to satisfy the request. alloc_pages() can only
5436 * allocate memory in power-of-two pages.
5438 * This function is also limited by MAX_ORDER.
5440 * Memory allocated by this function must be released by free_pages_exact().
5442 * Return: pointer to the allocated area or %NULL in case of error.
5444 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
5446 unsigned int order
= get_order(size
);
5449 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5450 gfp_mask
&= ~__GFP_COMP
;
5452 addr
= __get_free_pages(gfp_mask
, order
);
5453 return make_alloc_exact(addr
, order
, size
);
5455 EXPORT_SYMBOL(alloc_pages_exact
);
5458 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5460 * @nid: the preferred node ID where memory should be allocated
5461 * @size: the number of bytes to allocate
5462 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5464 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5467 * Return: pointer to the allocated area or %NULL in case of error.
5469 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
5471 unsigned int order
= get_order(size
);
5474 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5475 gfp_mask
&= ~__GFP_COMP
;
5477 p
= alloc_pages_node(nid
, gfp_mask
, order
);
5480 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
5484 * free_pages_exact - release memory allocated via alloc_pages_exact()
5485 * @virt: the value returned by alloc_pages_exact.
5486 * @size: size of allocation, same value as passed to alloc_pages_exact().
5488 * Release the memory allocated by a previous call to alloc_pages_exact.
5490 void free_pages_exact(void *virt
, size_t size
)
5492 unsigned long addr
= (unsigned long)virt
;
5493 unsigned long end
= addr
+ PAGE_ALIGN(size
);
5495 while (addr
< end
) {
5500 EXPORT_SYMBOL(free_pages_exact
);
5503 * nr_free_zone_pages - count number of pages beyond high watermark
5504 * @offset: The zone index of the highest zone
5506 * nr_free_zone_pages() counts the number of pages which are beyond the
5507 * high watermark within all zones at or below a given zone index. For each
5508 * zone, the number of pages is calculated as:
5510 * nr_free_zone_pages = managed_pages - high_pages
5512 * Return: number of pages beyond high watermark.
5514 static unsigned long nr_free_zone_pages(int offset
)
5519 /* Just pick one node, since fallback list is circular */
5520 unsigned long sum
= 0;
5522 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
5524 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
5525 unsigned long size
= zone_managed_pages(zone
);
5526 unsigned long high
= high_wmark_pages(zone
);
5535 * nr_free_buffer_pages - count number of pages beyond high watermark
5537 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5538 * watermark within ZONE_DMA and ZONE_NORMAL.
5540 * Return: number of pages beyond high watermark within ZONE_DMA and
5543 unsigned long nr_free_buffer_pages(void)
5545 return nr_free_zone_pages(gfp_zone(GFP_USER
));
5547 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
5549 static inline void show_node(struct zone
*zone
)
5551 if (IS_ENABLED(CONFIG_NUMA
))
5552 printk("Node %d ", zone_to_nid(zone
));
5555 long si_mem_available(void)
5558 unsigned long pagecache
;
5559 unsigned long wmark_low
= 0;
5560 unsigned long pages
[NR_LRU_LISTS
];
5561 unsigned long reclaimable
;
5565 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
5566 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
5569 wmark_low
+= low_wmark_pages(zone
);
5572 * Estimate the amount of memory available for userspace allocations,
5573 * without causing swapping.
5575 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
5578 * Not all the page cache can be freed, otherwise the system will
5579 * start swapping. Assume at least half of the page cache, or the
5580 * low watermark worth of cache, needs to stay.
5582 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
5583 pagecache
-= min(pagecache
/ 2, wmark_low
);
5584 available
+= pagecache
;
5587 * Part of the reclaimable slab and other kernel memory consists of
5588 * items that are in use, and cannot be freed. Cap this estimate at the
5591 reclaimable
= global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
) +
5592 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE
);
5593 available
+= reclaimable
- min(reclaimable
/ 2, wmark_low
);
5599 EXPORT_SYMBOL_GPL(si_mem_available
);
5601 void si_meminfo(struct sysinfo
*val
)
5603 val
->totalram
= totalram_pages();
5604 val
->sharedram
= global_node_page_state(NR_SHMEM
);
5605 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
5606 val
->bufferram
= nr_blockdev_pages();
5607 val
->totalhigh
= totalhigh_pages();
5608 val
->freehigh
= nr_free_highpages();
5609 val
->mem_unit
= PAGE_SIZE
;
5612 EXPORT_SYMBOL(si_meminfo
);
5615 void si_meminfo_node(struct sysinfo
*val
, int nid
)
5617 int zone_type
; /* needs to be signed */
5618 unsigned long managed_pages
= 0;
5619 unsigned long managed_highpages
= 0;
5620 unsigned long free_highpages
= 0;
5621 pg_data_t
*pgdat
= NODE_DATA(nid
);
5623 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
5624 managed_pages
+= zone_managed_pages(&pgdat
->node_zones
[zone_type
]);
5625 val
->totalram
= managed_pages
;
5626 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
5627 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
5628 #ifdef CONFIG_HIGHMEM
5629 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
5630 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5632 if (is_highmem(zone
)) {
5633 managed_highpages
+= zone_managed_pages(zone
);
5634 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
5637 val
->totalhigh
= managed_highpages
;
5638 val
->freehigh
= free_highpages
;
5640 val
->totalhigh
= managed_highpages
;
5641 val
->freehigh
= free_highpages
;
5643 val
->mem_unit
= PAGE_SIZE
;
5648 * Determine whether the node should be displayed or not, depending on whether
5649 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5651 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
5653 if (!(flags
& SHOW_MEM_FILTER_NODES
))
5657 * no node mask - aka implicit memory numa policy. Do not bother with
5658 * the synchronization - read_mems_allowed_begin - because we do not
5659 * have to be precise here.
5662 nodemask
= &cpuset_current_mems_allowed
;
5664 return !node_isset(nid
, *nodemask
);
5667 #define K(x) ((x) << (PAGE_SHIFT-10))
5669 static void show_migration_types(unsigned char type
)
5671 static const char types
[MIGRATE_TYPES
] = {
5672 [MIGRATE_UNMOVABLE
] = 'U',
5673 [MIGRATE_MOVABLE
] = 'M',
5674 [MIGRATE_RECLAIMABLE
] = 'E',
5675 [MIGRATE_HIGHATOMIC
] = 'H',
5677 [MIGRATE_CMA
] = 'C',
5679 #ifdef CONFIG_MEMORY_ISOLATION
5680 [MIGRATE_ISOLATE
] = 'I',
5683 char tmp
[MIGRATE_TYPES
+ 1];
5687 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
5688 if (type
& (1 << i
))
5693 printk(KERN_CONT
"(%s) ", tmp
);
5697 * Show free area list (used inside shift_scroll-lock stuff)
5698 * We also calculate the percentage fragmentation. We do this by counting the
5699 * memory on each free list with the exception of the first item on the list.
5702 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5705 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
5707 unsigned long free_pcp
= 0;
5712 for_each_populated_zone(zone
) {
5713 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5716 for_each_online_cpu(cpu
)
5717 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5720 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5721 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5722 " unevictable:%lu dirty:%lu writeback:%lu\n"
5723 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5724 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5725 " free:%lu free_pcp:%lu free_cma:%lu\n",
5726 global_node_page_state(NR_ACTIVE_ANON
),
5727 global_node_page_state(NR_INACTIVE_ANON
),
5728 global_node_page_state(NR_ISOLATED_ANON
),
5729 global_node_page_state(NR_ACTIVE_FILE
),
5730 global_node_page_state(NR_INACTIVE_FILE
),
5731 global_node_page_state(NR_ISOLATED_FILE
),
5732 global_node_page_state(NR_UNEVICTABLE
),
5733 global_node_page_state(NR_FILE_DIRTY
),
5734 global_node_page_state(NR_WRITEBACK
),
5735 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
),
5736 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B
),
5737 global_node_page_state(NR_FILE_MAPPED
),
5738 global_node_page_state(NR_SHMEM
),
5739 global_node_page_state(NR_PAGETABLE
),
5740 global_zone_page_state(NR_BOUNCE
),
5741 global_zone_page_state(NR_FREE_PAGES
),
5743 global_zone_page_state(NR_FREE_CMA_PAGES
));
5745 for_each_online_pgdat(pgdat
) {
5746 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
5750 " active_anon:%lukB"
5751 " inactive_anon:%lukB"
5752 " active_file:%lukB"
5753 " inactive_file:%lukB"
5754 " unevictable:%lukB"
5755 " isolated(anon):%lukB"
5756 " isolated(file):%lukB"
5761 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5763 " shmem_pmdmapped: %lukB"
5766 " writeback_tmp:%lukB"
5767 " kernel_stack:%lukB"
5768 #ifdef CONFIG_SHADOW_CALL_STACK
5769 " shadow_call_stack:%lukB"
5772 " all_unreclaimable? %s"
5775 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
5776 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
5777 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
5778 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
5779 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
5780 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
5781 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
5782 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
5783 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
5784 K(node_page_state(pgdat
, NR_WRITEBACK
)),
5785 K(node_page_state(pgdat
, NR_SHMEM
)),
5786 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5787 K(node_page_state(pgdat
, NR_SHMEM_THPS
)),
5788 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)),
5789 K(node_page_state(pgdat
, NR_ANON_THPS
)),
5791 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
5792 node_page_state(pgdat
, NR_KERNEL_STACK_KB
),
5793 #ifdef CONFIG_SHADOW_CALL_STACK
5794 node_page_state(pgdat
, NR_KERNEL_SCS_KB
),
5796 K(node_page_state(pgdat
, NR_PAGETABLE
)),
5797 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
5801 for_each_populated_zone(zone
) {
5804 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5808 for_each_online_cpu(cpu
)
5809 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5818 " reserved_highatomic:%luKB"
5819 " active_anon:%lukB"
5820 " inactive_anon:%lukB"
5821 " active_file:%lukB"
5822 " inactive_file:%lukB"
5823 " unevictable:%lukB"
5824 " writepending:%lukB"
5834 K(zone_page_state(zone
, NR_FREE_PAGES
)),
5835 K(min_wmark_pages(zone
)),
5836 K(low_wmark_pages(zone
)),
5837 K(high_wmark_pages(zone
)),
5838 K(zone
->nr_reserved_highatomic
),
5839 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
5840 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
5841 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
5842 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
5843 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
5844 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
5845 K(zone
->present_pages
),
5846 K(zone_managed_pages(zone
)),
5847 K(zone_page_state(zone
, NR_MLOCK
)),
5848 K(zone_page_state(zone
, NR_BOUNCE
)),
5850 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
5851 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
5852 printk("lowmem_reserve[]:");
5853 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
5854 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
5855 printk(KERN_CONT
"\n");
5858 for_each_populated_zone(zone
) {
5860 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
5861 unsigned char types
[MAX_ORDER
];
5863 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5866 printk(KERN_CONT
"%s: ", zone
->name
);
5868 spin_lock_irqsave(&zone
->lock
, flags
);
5869 for (order
= 0; order
< MAX_ORDER
; order
++) {
5870 struct free_area
*area
= &zone
->free_area
[order
];
5873 nr
[order
] = area
->nr_free
;
5874 total
+= nr
[order
] << order
;
5877 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
5878 if (!free_area_empty(area
, type
))
5879 types
[order
] |= 1 << type
;
5882 spin_unlock_irqrestore(&zone
->lock
, flags
);
5883 for (order
= 0; order
< MAX_ORDER
; order
++) {
5884 printk(KERN_CONT
"%lu*%lukB ",
5885 nr
[order
], K(1UL) << order
);
5887 show_migration_types(types
[order
]);
5889 printk(KERN_CONT
"= %lukB\n", K(total
));
5892 hugetlb_show_meminfo();
5894 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
5896 show_swap_cache_info();
5899 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
5901 zoneref
->zone
= zone
;
5902 zoneref
->zone_idx
= zone_idx(zone
);
5906 * Builds allocation fallback zone lists.
5908 * Add all populated zones of a node to the zonelist.
5910 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
5913 enum zone_type zone_type
= MAX_NR_ZONES
;
5918 zone
= pgdat
->node_zones
+ zone_type
;
5919 if (managed_zone(zone
)) {
5920 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
5921 check_highest_zone(zone_type
);
5923 } while (zone_type
);
5930 static int __parse_numa_zonelist_order(char *s
)
5933 * We used to support different zonlists modes but they turned
5934 * out to be just not useful. Let's keep the warning in place
5935 * if somebody still use the cmd line parameter so that we do
5936 * not fail it silently
5938 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
5939 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
5945 char numa_zonelist_order
[] = "Node";
5948 * sysctl handler for numa_zonelist_order
5950 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
5951 void *buffer
, size_t *length
, loff_t
*ppos
)
5954 return __parse_numa_zonelist_order(buffer
);
5955 return proc_dostring(table
, write
, buffer
, length
, ppos
);
5959 #define MAX_NODE_LOAD (nr_online_nodes)
5960 static int node_load
[MAX_NUMNODES
];
5963 * find_next_best_node - find the next node that should appear in a given node's fallback list
5964 * @node: node whose fallback list we're appending
5965 * @used_node_mask: nodemask_t of already used nodes
5967 * We use a number of factors to determine which is the next node that should
5968 * appear on a given node's fallback list. The node should not have appeared
5969 * already in @node's fallback list, and it should be the next closest node
5970 * according to the distance array (which contains arbitrary distance values
5971 * from each node to each node in the system), and should also prefer nodes
5972 * with no CPUs, since presumably they'll have very little allocation pressure
5973 * on them otherwise.
5975 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5977 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
5980 int min_val
= INT_MAX
;
5981 int best_node
= NUMA_NO_NODE
;
5983 /* Use the local node if we haven't already */
5984 if (!node_isset(node
, *used_node_mask
)) {
5985 node_set(node
, *used_node_mask
);
5989 for_each_node_state(n
, N_MEMORY
) {
5991 /* Don't want a node to appear more than once */
5992 if (node_isset(n
, *used_node_mask
))
5995 /* Use the distance array to find the distance */
5996 val
= node_distance(node
, n
);
5998 /* Penalize nodes under us ("prefer the next node") */
6001 /* Give preference to headless and unused nodes */
6002 if (!cpumask_empty(cpumask_of_node(n
)))
6003 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
6005 /* Slight preference for less loaded node */
6006 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
6007 val
+= node_load
[n
];
6009 if (val
< min_val
) {
6016 node_set(best_node
, *used_node_mask
);
6023 * Build zonelists ordered by node and zones within node.
6024 * This results in maximum locality--normal zone overflows into local
6025 * DMA zone, if any--but risks exhausting DMA zone.
6027 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
6030 struct zoneref
*zonerefs
;
6033 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
6035 for (i
= 0; i
< nr_nodes
; i
++) {
6038 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
6040 nr_zones
= build_zonerefs_node(node
, zonerefs
);
6041 zonerefs
+= nr_zones
;
6043 zonerefs
->zone
= NULL
;
6044 zonerefs
->zone_idx
= 0;
6048 * Build gfp_thisnode zonelists
6050 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
6052 struct zoneref
*zonerefs
;
6055 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
6056 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
6057 zonerefs
+= nr_zones
;
6058 zonerefs
->zone
= NULL
;
6059 zonerefs
->zone_idx
= 0;
6063 * Build zonelists ordered by zone and nodes within zones.
6064 * This results in conserving DMA zone[s] until all Normal memory is
6065 * exhausted, but results in overflowing to remote node while memory
6066 * may still exist in local DMA zone.
6069 static void build_zonelists(pg_data_t
*pgdat
)
6071 static int node_order
[MAX_NUMNODES
];
6072 int node
, load
, nr_nodes
= 0;
6073 nodemask_t used_mask
= NODE_MASK_NONE
;
6074 int local_node
, prev_node
;
6076 /* NUMA-aware ordering of nodes */
6077 local_node
= pgdat
->node_id
;
6078 load
= nr_online_nodes
;
6079 prev_node
= local_node
;
6081 memset(node_order
, 0, sizeof(node_order
));
6082 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
6084 * We don't want to pressure a particular node.
6085 * So adding penalty to the first node in same
6086 * distance group to make it round-robin.
6088 if (node_distance(local_node
, node
) !=
6089 node_distance(local_node
, prev_node
))
6090 node_load
[node
] = load
;
6092 node_order
[nr_nodes
++] = node
;
6097 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
6098 build_thisnode_zonelists(pgdat
);
6101 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
6103 * Return node id of node used for "local" allocations.
6104 * I.e., first node id of first zone in arg node's generic zonelist.
6105 * Used for initializing percpu 'numa_mem', which is used primarily
6106 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
6108 int local_memory_node(int node
)
6112 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
6113 gfp_zone(GFP_KERNEL
),
6115 return zone_to_nid(z
->zone
);
6119 static void setup_min_unmapped_ratio(void);
6120 static void setup_min_slab_ratio(void);
6121 #else /* CONFIG_NUMA */
6123 static void build_zonelists(pg_data_t
*pgdat
)
6125 int node
, local_node
;
6126 struct zoneref
*zonerefs
;
6129 local_node
= pgdat
->node_id
;
6131 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
6132 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
6133 zonerefs
+= nr_zones
;
6136 * Now we build the zonelist so that it contains the zones
6137 * of all the other nodes.
6138 * We don't want to pressure a particular node, so when
6139 * building the zones for node N, we make sure that the
6140 * zones coming right after the local ones are those from
6141 * node N+1 (modulo N)
6143 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
6144 if (!node_online(node
))
6146 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
6147 zonerefs
+= nr_zones
;
6149 for (node
= 0; node
< local_node
; node
++) {
6150 if (!node_online(node
))
6152 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
6153 zonerefs
+= nr_zones
;
6156 zonerefs
->zone
= NULL
;
6157 zonerefs
->zone_idx
= 0;
6160 #endif /* CONFIG_NUMA */
6163 * Boot pageset table. One per cpu which is going to be used for all
6164 * zones and all nodes. The parameters will be set in such a way
6165 * that an item put on a list will immediately be handed over to
6166 * the buddy list. This is safe since pageset manipulation is done
6167 * with interrupts disabled.
6169 * The boot_pagesets must be kept even after bootup is complete for
6170 * unused processors and/or zones. They do play a role for bootstrapping
6171 * hotplugged processors.
6173 * zoneinfo_show() and maybe other functions do
6174 * not check if the processor is online before following the pageset pointer.
6175 * Other parts of the kernel may not check if the zone is available.
6177 static void pageset_init(struct per_cpu_pageset
*p
);
6178 /* These effectively disable the pcplists in the boot pageset completely */
6179 #define BOOT_PAGESET_HIGH 0
6180 #define BOOT_PAGESET_BATCH 1
6181 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
6182 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
6184 static void __build_all_zonelists(void *data
)
6187 int __maybe_unused cpu
;
6188 pg_data_t
*self
= data
;
6189 static DEFINE_SPINLOCK(lock
);
6194 memset(node_load
, 0, sizeof(node_load
));
6198 * This node is hotadded and no memory is yet present. So just
6199 * building zonelists is fine - no need to touch other nodes.
6201 if (self
&& !node_online(self
->node_id
)) {
6202 build_zonelists(self
);
6204 for_each_online_node(nid
) {
6205 pg_data_t
*pgdat
= NODE_DATA(nid
);
6207 build_zonelists(pgdat
);
6210 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
6212 * We now know the "local memory node" for each node--
6213 * i.e., the node of the first zone in the generic zonelist.
6214 * Set up numa_mem percpu variable for on-line cpus. During
6215 * boot, only the boot cpu should be on-line; we'll init the
6216 * secondary cpus' numa_mem as they come on-line. During
6217 * node/memory hotplug, we'll fixup all on-line cpus.
6219 for_each_online_cpu(cpu
)
6220 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
6227 static noinline
void __init
6228 build_all_zonelists_init(void)
6232 __build_all_zonelists(NULL
);
6235 * Initialize the boot_pagesets that are going to be used
6236 * for bootstrapping processors. The real pagesets for
6237 * each zone will be allocated later when the per cpu
6238 * allocator is available.
6240 * boot_pagesets are used also for bootstrapping offline
6241 * cpus if the system is already booted because the pagesets
6242 * are needed to initialize allocators on a specific cpu too.
6243 * F.e. the percpu allocator needs the page allocator which
6244 * needs the percpu allocator in order to allocate its pagesets
6245 * (a chicken-egg dilemma).
6247 for_each_possible_cpu(cpu
)
6248 pageset_init(&per_cpu(boot_pageset
, cpu
));
6250 mminit_verify_zonelist();
6251 cpuset_init_current_mems_allowed();
6255 * unless system_state == SYSTEM_BOOTING.
6257 * __ref due to call of __init annotated helper build_all_zonelists_init
6258 * [protected by SYSTEM_BOOTING].
6260 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
6262 unsigned long vm_total_pages
;
6264 if (system_state
== SYSTEM_BOOTING
) {
6265 build_all_zonelists_init();
6267 __build_all_zonelists(pgdat
);
6268 /* cpuset refresh routine should be here */
6270 /* Get the number of free pages beyond high watermark in all zones. */
6271 vm_total_pages
= nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
6273 * Disable grouping by mobility if the number of pages in the
6274 * system is too low to allow the mechanism to work. It would be
6275 * more accurate, but expensive to check per-zone. This check is
6276 * made on memory-hotadd so a system can start with mobility
6277 * disabled and enable it later
6279 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
6280 page_group_by_mobility_disabled
= 1;
6282 page_group_by_mobility_disabled
= 0;
6284 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
6286 page_group_by_mobility_disabled
? "off" : "on",
6289 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
6293 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
6294 static bool __meminit
6295 overlap_memmap_init(unsigned long zone
, unsigned long *pfn
)
6297 static struct memblock_region
*r
;
6299 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
6300 if (!r
|| *pfn
>= memblock_region_memory_end_pfn(r
)) {
6301 for_each_mem_region(r
) {
6302 if (*pfn
< memblock_region_memory_end_pfn(r
))
6306 if (*pfn
>= memblock_region_memory_base_pfn(r
) &&
6307 memblock_is_mirror(r
)) {
6308 *pfn
= memblock_region_memory_end_pfn(r
);
6316 * Initially all pages are reserved - free ones are freed
6317 * up by memblock_free_all() once the early boot process is
6318 * done. Non-atomic initialization, single-pass.
6320 * All aligned pageblocks are initialized to the specified migratetype
6321 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related
6322 * zone stats (e.g., nr_isolate_pageblock) are touched.
6324 void __meminit
memmap_init_range(unsigned long size
, int nid
, unsigned long zone
,
6325 unsigned long start_pfn
, unsigned long zone_end_pfn
,
6326 enum meminit_context context
,
6327 struct vmem_altmap
*altmap
, int migratetype
)
6329 unsigned long pfn
, end_pfn
= start_pfn
+ size
;
6332 if (highest_memmap_pfn
< end_pfn
- 1)
6333 highest_memmap_pfn
= end_pfn
- 1;
6335 #ifdef CONFIG_ZONE_DEVICE
6337 * Honor reservation requested by the driver for this ZONE_DEVICE
6338 * memory. We limit the total number of pages to initialize to just
6339 * those that might contain the memory mapping. We will defer the
6340 * ZONE_DEVICE page initialization until after we have released
6343 if (zone
== ZONE_DEVICE
) {
6347 if (start_pfn
== altmap
->base_pfn
)
6348 start_pfn
+= altmap
->reserve
;
6349 end_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6353 for (pfn
= start_pfn
; pfn
< end_pfn
; ) {
6355 * There can be holes in boot-time mem_map[]s handed to this
6356 * function. They do not exist on hotplugged memory.
6358 if (context
== MEMINIT_EARLY
) {
6359 if (overlap_memmap_init(zone
, &pfn
))
6361 if (defer_init(nid
, pfn
, zone_end_pfn
))
6365 page
= pfn_to_page(pfn
);
6366 __init_single_page(page
, pfn
, zone
, nid
);
6367 if (context
== MEMINIT_HOTPLUG
)
6368 __SetPageReserved(page
);
6371 * Usually, we want to mark the pageblock MIGRATE_MOVABLE,
6372 * such that unmovable allocations won't be scattered all
6373 * over the place during system boot.
6375 if (IS_ALIGNED(pfn
, pageblock_nr_pages
)) {
6376 set_pageblock_migratetype(page
, migratetype
);
6383 #ifdef CONFIG_ZONE_DEVICE
6384 void __ref
memmap_init_zone_device(struct zone
*zone
,
6385 unsigned long start_pfn
,
6386 unsigned long nr_pages
,
6387 struct dev_pagemap
*pgmap
)
6389 unsigned long pfn
, end_pfn
= start_pfn
+ nr_pages
;
6390 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6391 struct vmem_altmap
*altmap
= pgmap_altmap(pgmap
);
6392 unsigned long zone_idx
= zone_idx(zone
);
6393 unsigned long start
= jiffies
;
6394 int nid
= pgdat
->node_id
;
6396 if (WARN_ON_ONCE(!pgmap
|| zone_idx(zone
) != ZONE_DEVICE
))
6400 * The call to memmap_init_zone should have already taken care
6401 * of the pages reserved for the memmap, so we can just jump to
6402 * the end of that region and start processing the device pages.
6405 start_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6406 nr_pages
= end_pfn
- start_pfn
;
6409 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
6410 struct page
*page
= pfn_to_page(pfn
);
6412 __init_single_page(page
, pfn
, zone_idx
, nid
);
6415 * Mark page reserved as it will need to wait for onlining
6416 * phase for it to be fully associated with a zone.
6418 * We can use the non-atomic __set_bit operation for setting
6419 * the flag as we are still initializing the pages.
6421 __SetPageReserved(page
);
6424 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6425 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6426 * ever freed or placed on a driver-private list.
6428 page
->pgmap
= pgmap
;
6429 page
->zone_device_data
= NULL
;
6432 * Mark the block movable so that blocks are reserved for
6433 * movable at startup. This will force kernel allocations
6434 * to reserve their blocks rather than leaking throughout
6435 * the address space during boot when many long-lived
6436 * kernel allocations are made.
6438 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6439 * because this is done early in section_activate()
6441 if (IS_ALIGNED(pfn
, pageblock_nr_pages
)) {
6442 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
6447 pr_info("%s initialised %lu pages in %ums\n", __func__
,
6448 nr_pages
, jiffies_to_msecs(jiffies
- start
));
6452 static void __meminit
zone_init_free_lists(struct zone
*zone
)
6454 unsigned int order
, t
;
6455 for_each_migratetype_order(order
, t
) {
6456 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
6457 zone
->free_area
[order
].nr_free
= 0;
6461 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
6463 * Only struct pages that correspond to ranges defined by memblock.memory
6464 * are zeroed and initialized by going through __init_single_page() during
6465 * memmap_init_zone().
6467 * But, there could be struct pages that correspond to holes in
6468 * memblock.memory. This can happen because of the following reasons:
6469 * - physical memory bank size is not necessarily the exact multiple of the
6470 * arbitrary section size
6471 * - early reserved memory may not be listed in memblock.memory
6472 * - memory layouts defined with memmap= kernel parameter may not align
6473 * nicely with memmap sections
6475 * Explicitly initialize those struct pages so that:
6476 * - PG_Reserved is set
6477 * - zone and node links point to zone and node that span the page if the
6478 * hole is in the middle of a zone
6479 * - zone and node links point to adjacent zone/node if the hole falls on
6480 * the zone boundary; the pages in such holes will be prepended to the
6481 * zone/node above the hole except for the trailing pages in the last
6482 * section that will be appended to the zone/node below.
6484 static u64 __meminit
init_unavailable_range(unsigned long spfn
,
6491 for (pfn
= spfn
; pfn
< epfn
; pfn
++) {
6492 if (!pfn_valid(ALIGN_DOWN(pfn
, pageblock_nr_pages
))) {
6493 pfn
= ALIGN_DOWN(pfn
, pageblock_nr_pages
)
6494 + pageblock_nr_pages
- 1;
6497 __init_single_page(pfn_to_page(pfn
), pfn
, zone
, node
);
6498 __SetPageReserved(pfn_to_page(pfn
));
6505 static inline u64
init_unavailable_range(unsigned long spfn
, unsigned long epfn
,
6512 void __meminit __weak
memmap_init_zone(struct zone
*zone
)
6514 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6515 unsigned long zone_end_pfn
= zone_start_pfn
+ zone
->spanned_pages
;
6516 int i
, nid
= zone_to_nid(zone
), zone_id
= zone_idx(zone
);
6517 static unsigned long hole_pfn
;
6518 unsigned long start_pfn
, end_pfn
;
6521 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6522 start_pfn
= clamp(start_pfn
, zone_start_pfn
, zone_end_pfn
);
6523 end_pfn
= clamp(end_pfn
, zone_start_pfn
, zone_end_pfn
);
6525 if (end_pfn
> start_pfn
)
6526 memmap_init_range(end_pfn
- start_pfn
, nid
,
6527 zone_id
, start_pfn
, zone_end_pfn
,
6528 MEMINIT_EARLY
, NULL
, MIGRATE_MOVABLE
);
6530 if (hole_pfn
< start_pfn
)
6531 pgcnt
+= init_unavailable_range(hole_pfn
, start_pfn
,
6536 #ifdef CONFIG_SPARSEMEM
6538 * Initialize the hole in the range [zone_end_pfn, section_end].
6539 * If zone boundary falls in the middle of a section, this hole
6540 * will be re-initialized during the call to this function for the
6543 end_pfn
= round_up(zone_end_pfn
, PAGES_PER_SECTION
);
6544 if (hole_pfn
< end_pfn
)
6545 pgcnt
+= init_unavailable_range(hole_pfn
, end_pfn
,
6550 pr_info(" %s zone: %llu pages in unavailable ranges\n",
6554 static int zone_batchsize(struct zone
*zone
)
6560 * The per-cpu-pages pools are set to around 1000th of the
6563 batch
= zone_managed_pages(zone
) / 1024;
6564 /* But no more than a meg. */
6565 if (batch
* PAGE_SIZE
> 1024 * 1024)
6566 batch
= (1024 * 1024) / PAGE_SIZE
;
6567 batch
/= 4; /* We effectively *= 4 below */
6572 * Clamp the batch to a 2^n - 1 value. Having a power
6573 * of 2 value was found to be more likely to have
6574 * suboptimal cache aliasing properties in some cases.
6576 * For example if 2 tasks are alternately allocating
6577 * batches of pages, one task can end up with a lot
6578 * of pages of one half of the possible page colors
6579 * and the other with pages of the other colors.
6581 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
6586 /* The deferral and batching of frees should be suppressed under NOMMU
6589 * The problem is that NOMMU needs to be able to allocate large chunks
6590 * of contiguous memory as there's no hardware page translation to
6591 * assemble apparent contiguous memory from discontiguous pages.
6593 * Queueing large contiguous runs of pages for batching, however,
6594 * causes the pages to actually be freed in smaller chunks. As there
6595 * can be a significant delay between the individual batches being
6596 * recycled, this leads to the once large chunks of space being
6597 * fragmented and becoming unavailable for high-order allocations.
6604 * pcp->high and pcp->batch values are related and generally batch is lower
6605 * than high. They are also related to pcp->count such that count is lower
6606 * than high, and as soon as it reaches high, the pcplist is flushed.
6608 * However, guaranteeing these relations at all times would require e.g. write
6609 * barriers here but also careful usage of read barriers at the read side, and
6610 * thus be prone to error and bad for performance. Thus the update only prevents
6611 * store tearing. Any new users of pcp->batch and pcp->high should ensure they
6612 * can cope with those fields changing asynchronously, and fully trust only the
6613 * pcp->count field on the local CPU with interrupts disabled.
6615 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6616 * outside of boot time (or some other assurance that no concurrent updaters
6619 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
6620 unsigned long batch
)
6622 WRITE_ONCE(pcp
->batch
, batch
);
6623 WRITE_ONCE(pcp
->high
, high
);
6626 static void pageset_init(struct per_cpu_pageset
*p
)
6628 struct per_cpu_pages
*pcp
;
6631 memset(p
, 0, sizeof(*p
));
6634 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
6635 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
6638 * Set batch and high values safe for a boot pageset. A true percpu
6639 * pageset's initialization will update them subsequently. Here we don't
6640 * need to be as careful as pageset_update() as nobody can access the
6643 pcp
->high
= BOOT_PAGESET_HIGH
;
6644 pcp
->batch
= BOOT_PAGESET_BATCH
;
6647 static void __zone_set_pageset_high_and_batch(struct zone
*zone
, unsigned long high
,
6648 unsigned long batch
)
6650 struct per_cpu_pageset
*p
;
6653 for_each_possible_cpu(cpu
) {
6654 p
= per_cpu_ptr(zone
->pageset
, cpu
);
6655 pageset_update(&p
->pcp
, high
, batch
);
6660 * Calculate and set new high and batch values for all per-cpu pagesets of a
6661 * zone, based on the zone's size and the percpu_pagelist_fraction sysctl.
6663 static void zone_set_pageset_high_and_batch(struct zone
*zone
)
6665 unsigned long new_high
, new_batch
;
6667 if (percpu_pagelist_fraction
) {
6668 new_high
= zone_managed_pages(zone
) / percpu_pagelist_fraction
;
6669 new_batch
= max(1UL, new_high
/ 4);
6670 if ((new_high
/ 4) > (PAGE_SHIFT
* 8))
6671 new_batch
= PAGE_SHIFT
* 8;
6673 new_batch
= zone_batchsize(zone
);
6674 new_high
= 6 * new_batch
;
6675 new_batch
= max(1UL, 1 * new_batch
);
6678 if (zone
->pageset_high
== new_high
&&
6679 zone
->pageset_batch
== new_batch
)
6682 zone
->pageset_high
= new_high
;
6683 zone
->pageset_batch
= new_batch
;
6685 __zone_set_pageset_high_and_batch(zone
, new_high
, new_batch
);
6688 void __meminit
setup_zone_pageset(struct zone
*zone
)
6690 struct per_cpu_pageset
*p
;
6693 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
6694 for_each_possible_cpu(cpu
) {
6695 p
= per_cpu_ptr(zone
->pageset
, cpu
);
6699 zone_set_pageset_high_and_batch(zone
);
6703 * Allocate per cpu pagesets and initialize them.
6704 * Before this call only boot pagesets were available.
6706 void __init
setup_per_cpu_pageset(void)
6708 struct pglist_data
*pgdat
;
6710 int __maybe_unused cpu
;
6712 for_each_populated_zone(zone
)
6713 setup_zone_pageset(zone
);
6717 * Unpopulated zones continue using the boot pagesets.
6718 * The numa stats for these pagesets need to be reset.
6719 * Otherwise, they will end up skewing the stats of
6720 * the nodes these zones are associated with.
6722 for_each_possible_cpu(cpu
) {
6723 struct per_cpu_pageset
*pcp
= &per_cpu(boot_pageset
, cpu
);
6724 memset(pcp
->vm_numa_stat_diff
, 0,
6725 sizeof(pcp
->vm_numa_stat_diff
));
6729 for_each_online_pgdat(pgdat
)
6730 pgdat
->per_cpu_nodestats
=
6731 alloc_percpu(struct per_cpu_nodestat
);
6734 static __meminit
void zone_pcp_init(struct zone
*zone
)
6737 * per cpu subsystem is not up at this point. The following code
6738 * relies on the ability of the linker to provide the
6739 * offset of a (static) per cpu variable into the per cpu area.
6741 zone
->pageset
= &boot_pageset
;
6742 zone
->pageset_high
= BOOT_PAGESET_HIGH
;
6743 zone
->pageset_batch
= BOOT_PAGESET_BATCH
;
6745 if (populated_zone(zone
))
6746 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
6747 zone
->name
, zone
->present_pages
,
6748 zone_batchsize(zone
));
6751 void __meminit
init_currently_empty_zone(struct zone
*zone
,
6752 unsigned long zone_start_pfn
,
6755 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6756 int zone_idx
= zone_idx(zone
) + 1;
6758 if (zone_idx
> pgdat
->nr_zones
)
6759 pgdat
->nr_zones
= zone_idx
;
6761 zone
->zone_start_pfn
= zone_start_pfn
;
6763 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
6764 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6766 (unsigned long)zone_idx(zone
),
6767 zone_start_pfn
, (zone_start_pfn
+ size
));
6769 zone_init_free_lists(zone
);
6770 zone
->initialized
= 1;
6774 * get_pfn_range_for_nid - Return the start and end page frames for a node
6775 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6776 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6777 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6779 * It returns the start and end page frame of a node based on information
6780 * provided by memblock_set_node(). If called for a node
6781 * with no available memory, a warning is printed and the start and end
6784 void __init
get_pfn_range_for_nid(unsigned int nid
,
6785 unsigned long *start_pfn
, unsigned long *end_pfn
)
6787 unsigned long this_start_pfn
, this_end_pfn
;
6793 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
6794 *start_pfn
= min(*start_pfn
, this_start_pfn
);
6795 *end_pfn
= max(*end_pfn
, this_end_pfn
);
6798 if (*start_pfn
== -1UL)
6803 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6804 * assumption is made that zones within a node are ordered in monotonic
6805 * increasing memory addresses so that the "highest" populated zone is used
6807 static void __init
find_usable_zone_for_movable(void)
6810 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
6811 if (zone_index
== ZONE_MOVABLE
)
6814 if (arch_zone_highest_possible_pfn
[zone_index
] >
6815 arch_zone_lowest_possible_pfn
[zone_index
])
6819 VM_BUG_ON(zone_index
== -1);
6820 movable_zone
= zone_index
;
6824 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6825 * because it is sized independent of architecture. Unlike the other zones,
6826 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6827 * in each node depending on the size of each node and how evenly kernelcore
6828 * is distributed. This helper function adjusts the zone ranges
6829 * provided by the architecture for a given node by using the end of the
6830 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6831 * zones within a node are in order of monotonic increases memory addresses
6833 static void __init
adjust_zone_range_for_zone_movable(int nid
,
6834 unsigned long zone_type
,
6835 unsigned long node_start_pfn
,
6836 unsigned long node_end_pfn
,
6837 unsigned long *zone_start_pfn
,
6838 unsigned long *zone_end_pfn
)
6840 /* Only adjust if ZONE_MOVABLE is on this node */
6841 if (zone_movable_pfn
[nid
]) {
6842 /* Size ZONE_MOVABLE */
6843 if (zone_type
== ZONE_MOVABLE
) {
6844 *zone_start_pfn
= zone_movable_pfn
[nid
];
6845 *zone_end_pfn
= min(node_end_pfn
,
6846 arch_zone_highest_possible_pfn
[movable_zone
]);
6848 /* Adjust for ZONE_MOVABLE starting within this range */
6849 } else if (!mirrored_kernelcore
&&
6850 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
6851 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
6852 *zone_end_pfn
= zone_movable_pfn
[nid
];
6854 /* Check if this whole range is within ZONE_MOVABLE */
6855 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
6856 *zone_start_pfn
= *zone_end_pfn
;
6861 * Return the number of pages a zone spans in a node, including holes
6862 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6864 static unsigned long __init
zone_spanned_pages_in_node(int nid
,
6865 unsigned long zone_type
,
6866 unsigned long node_start_pfn
,
6867 unsigned long node_end_pfn
,
6868 unsigned long *zone_start_pfn
,
6869 unsigned long *zone_end_pfn
)
6871 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6872 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6873 /* When hotadd a new node from cpu_up(), the node should be empty */
6874 if (!node_start_pfn
&& !node_end_pfn
)
6877 /* Get the start and end of the zone */
6878 *zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6879 *zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6880 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6881 node_start_pfn
, node_end_pfn
,
6882 zone_start_pfn
, zone_end_pfn
);
6884 /* Check that this node has pages within the zone's required range */
6885 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
6888 /* Move the zone boundaries inside the node if necessary */
6889 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
6890 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
6892 /* Return the spanned pages */
6893 return *zone_end_pfn
- *zone_start_pfn
;
6897 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6898 * then all holes in the requested range will be accounted for.
6900 unsigned long __init
__absent_pages_in_range(int nid
,
6901 unsigned long range_start_pfn
,
6902 unsigned long range_end_pfn
)
6904 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
6905 unsigned long start_pfn
, end_pfn
;
6908 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6909 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6910 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6911 nr_absent
-= end_pfn
- start_pfn
;
6917 * absent_pages_in_range - Return number of page frames in holes within a range
6918 * @start_pfn: The start PFN to start searching for holes
6919 * @end_pfn: The end PFN to stop searching for holes
6921 * Return: the number of pages frames in memory holes within a range.
6923 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
6924 unsigned long end_pfn
)
6926 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
6929 /* Return the number of page frames in holes in a zone on a node */
6930 static unsigned long __init
zone_absent_pages_in_node(int nid
,
6931 unsigned long zone_type
,
6932 unsigned long node_start_pfn
,
6933 unsigned long node_end_pfn
)
6935 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6936 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6937 unsigned long zone_start_pfn
, zone_end_pfn
;
6938 unsigned long nr_absent
;
6940 /* When hotadd a new node from cpu_up(), the node should be empty */
6941 if (!node_start_pfn
&& !node_end_pfn
)
6944 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6945 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6947 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6948 node_start_pfn
, node_end_pfn
,
6949 &zone_start_pfn
, &zone_end_pfn
);
6950 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
6953 * ZONE_MOVABLE handling.
6954 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6957 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
6958 unsigned long start_pfn
, end_pfn
;
6959 struct memblock_region
*r
;
6961 for_each_mem_region(r
) {
6962 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
6963 zone_start_pfn
, zone_end_pfn
);
6964 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
6965 zone_start_pfn
, zone_end_pfn
);
6967 if (zone_type
== ZONE_MOVABLE
&&
6968 memblock_is_mirror(r
))
6969 nr_absent
+= end_pfn
- start_pfn
;
6971 if (zone_type
== ZONE_NORMAL
&&
6972 !memblock_is_mirror(r
))
6973 nr_absent
+= end_pfn
- start_pfn
;
6980 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
6981 unsigned long node_start_pfn
,
6982 unsigned long node_end_pfn
)
6984 unsigned long realtotalpages
= 0, totalpages
= 0;
6987 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6988 struct zone
*zone
= pgdat
->node_zones
+ i
;
6989 unsigned long zone_start_pfn
, zone_end_pfn
;
6990 unsigned long spanned
, absent
;
6991 unsigned long size
, real_size
;
6993 spanned
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
6998 absent
= zone_absent_pages_in_node(pgdat
->node_id
, i
,
7003 real_size
= size
- absent
;
7006 zone
->zone_start_pfn
= zone_start_pfn
;
7008 zone
->zone_start_pfn
= 0;
7009 zone
->spanned_pages
= size
;
7010 zone
->present_pages
= real_size
;
7013 realtotalpages
+= real_size
;
7016 pgdat
->node_spanned_pages
= totalpages
;
7017 pgdat
->node_present_pages
= realtotalpages
;
7018 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
7022 #ifndef CONFIG_SPARSEMEM
7024 * Calculate the size of the zone->blockflags rounded to an unsigned long
7025 * Start by making sure zonesize is a multiple of pageblock_order by rounding
7026 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
7027 * round what is now in bits to nearest long in bits, then return it in
7030 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
7032 unsigned long usemapsize
;
7034 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
7035 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
7036 usemapsize
= usemapsize
>> pageblock_order
;
7037 usemapsize
*= NR_PAGEBLOCK_BITS
;
7038 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
7040 return usemapsize
/ 8;
7043 static void __ref
setup_usemap(struct zone
*zone
)
7045 unsigned long usemapsize
= usemap_size(zone
->zone_start_pfn
,
7046 zone
->spanned_pages
);
7047 zone
->pageblock_flags
= NULL
;
7049 zone
->pageblock_flags
=
7050 memblock_alloc_node(usemapsize
, SMP_CACHE_BYTES
,
7052 if (!zone
->pageblock_flags
)
7053 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
7054 usemapsize
, zone
->name
, zone_to_nid(zone
));
7058 static inline void setup_usemap(struct zone
*zone
) {}
7059 #endif /* CONFIG_SPARSEMEM */
7061 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
7063 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
7064 void __init
set_pageblock_order(void)
7068 /* Check that pageblock_nr_pages has not already been setup */
7069 if (pageblock_order
)
7072 if (HPAGE_SHIFT
> PAGE_SHIFT
)
7073 order
= HUGETLB_PAGE_ORDER
;
7075 order
= MAX_ORDER
- 1;
7078 * Assume the largest contiguous order of interest is a huge page.
7079 * This value may be variable depending on boot parameters on IA64 and
7082 pageblock_order
= order
;
7084 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
7087 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
7088 * is unused as pageblock_order is set at compile-time. See
7089 * include/linux/pageblock-flags.h for the values of pageblock_order based on
7092 void __init
set_pageblock_order(void)
7096 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
7098 static unsigned long __init
calc_memmap_size(unsigned long spanned_pages
,
7099 unsigned long present_pages
)
7101 unsigned long pages
= spanned_pages
;
7104 * Provide a more accurate estimation if there are holes within
7105 * the zone and SPARSEMEM is in use. If there are holes within the
7106 * zone, each populated memory region may cost us one or two extra
7107 * memmap pages due to alignment because memmap pages for each
7108 * populated regions may not be naturally aligned on page boundary.
7109 * So the (present_pages >> 4) heuristic is a tradeoff for that.
7111 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
7112 IS_ENABLED(CONFIG_SPARSEMEM
))
7113 pages
= present_pages
;
7115 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
7118 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
7119 static void pgdat_init_split_queue(struct pglist_data
*pgdat
)
7121 struct deferred_split
*ds_queue
= &pgdat
->deferred_split_queue
;
7123 spin_lock_init(&ds_queue
->split_queue_lock
);
7124 INIT_LIST_HEAD(&ds_queue
->split_queue
);
7125 ds_queue
->split_queue_len
= 0;
7128 static void pgdat_init_split_queue(struct pglist_data
*pgdat
) {}
7131 #ifdef CONFIG_COMPACTION
7132 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
)
7134 init_waitqueue_head(&pgdat
->kcompactd_wait
);
7137 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
) {}
7140 static void __meminit
pgdat_init_internals(struct pglist_data
*pgdat
)
7142 pgdat_resize_init(pgdat
);
7144 pgdat_init_split_queue(pgdat
);
7145 pgdat_init_kcompactd(pgdat
);
7147 init_waitqueue_head(&pgdat
->kswapd_wait
);
7148 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
7150 pgdat_page_ext_init(pgdat
);
7151 lruvec_init(&pgdat
->__lruvec
);
7154 static void __meminit
zone_init_internals(struct zone
*zone
, enum zone_type idx
, int nid
,
7155 unsigned long remaining_pages
)
7157 atomic_long_set(&zone
->managed_pages
, remaining_pages
);
7158 zone_set_nid(zone
, nid
);
7159 zone
->name
= zone_names
[idx
];
7160 zone
->zone_pgdat
= NODE_DATA(nid
);
7161 spin_lock_init(&zone
->lock
);
7162 zone_seqlock_init(zone
);
7163 zone_pcp_init(zone
);
7167 * Set up the zone data structures
7168 * - init pgdat internals
7169 * - init all zones belonging to this node
7171 * NOTE: this function is only called during memory hotplug
7173 #ifdef CONFIG_MEMORY_HOTPLUG
7174 void __ref
free_area_init_core_hotplug(int nid
)
7177 pg_data_t
*pgdat
= NODE_DATA(nid
);
7179 pgdat_init_internals(pgdat
);
7180 for (z
= 0; z
< MAX_NR_ZONES
; z
++)
7181 zone_init_internals(&pgdat
->node_zones
[z
], z
, nid
, 0);
7186 * Set up the zone data structures:
7187 * - mark all pages reserved
7188 * - mark all memory queues empty
7189 * - clear the memory bitmaps
7191 * NOTE: pgdat should get zeroed by caller.
7192 * NOTE: this function is only called during early init.
7194 static void __init
free_area_init_core(struct pglist_data
*pgdat
)
7197 int nid
= pgdat
->node_id
;
7199 pgdat_init_internals(pgdat
);
7200 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
7202 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
7203 struct zone
*zone
= pgdat
->node_zones
+ j
;
7204 unsigned long size
, freesize
, memmap_pages
;
7206 size
= zone
->spanned_pages
;
7207 freesize
= zone
->present_pages
;
7210 * Adjust freesize so that it accounts for how much memory
7211 * is used by this zone for memmap. This affects the watermark
7212 * and per-cpu initialisations
7214 memmap_pages
= calc_memmap_size(size
, freesize
);
7215 if (!is_highmem_idx(j
)) {
7216 if (freesize
>= memmap_pages
) {
7217 freesize
-= memmap_pages
;
7220 " %s zone: %lu pages used for memmap\n",
7221 zone_names
[j
], memmap_pages
);
7223 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
7224 zone_names
[j
], memmap_pages
, freesize
);
7227 /* Account for reserved pages */
7228 if (j
== 0 && freesize
> dma_reserve
) {
7229 freesize
-= dma_reserve
;
7230 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
7231 zone_names
[0], dma_reserve
);
7234 if (!is_highmem_idx(j
))
7235 nr_kernel_pages
+= freesize
;
7236 /* Charge for highmem memmap if there are enough kernel pages */
7237 else if (nr_kernel_pages
> memmap_pages
* 2)
7238 nr_kernel_pages
-= memmap_pages
;
7239 nr_all_pages
+= freesize
;
7242 * Set an approximate value for lowmem here, it will be adjusted
7243 * when the bootmem allocator frees pages into the buddy system.
7244 * And all highmem pages will be managed by the buddy system.
7246 zone_init_internals(zone
, j
, nid
, freesize
);
7251 set_pageblock_order();
7253 init_currently_empty_zone(zone
, zone
->zone_start_pfn
, size
);
7254 memmap_init_zone(zone
);
7258 #ifdef CONFIG_FLAT_NODE_MEM_MAP
7259 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
7261 unsigned long __maybe_unused start
= 0;
7262 unsigned long __maybe_unused offset
= 0;
7264 /* Skip empty nodes */
7265 if (!pgdat
->node_spanned_pages
)
7268 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
7269 offset
= pgdat
->node_start_pfn
- start
;
7270 /* ia64 gets its own node_mem_map, before this, without bootmem */
7271 if (!pgdat
->node_mem_map
) {
7272 unsigned long size
, end
;
7276 * The zone's endpoints aren't required to be MAX_ORDER
7277 * aligned but the node_mem_map endpoints must be in order
7278 * for the buddy allocator to function correctly.
7280 end
= pgdat_end_pfn(pgdat
);
7281 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
7282 size
= (end
- start
) * sizeof(struct page
);
7283 map
= memblock_alloc_node(size
, SMP_CACHE_BYTES
,
7286 panic("Failed to allocate %ld bytes for node %d memory map\n",
7287 size
, pgdat
->node_id
);
7288 pgdat
->node_mem_map
= map
+ offset
;
7290 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
7291 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
7292 (unsigned long)pgdat
->node_mem_map
);
7293 #ifndef CONFIG_NEED_MULTIPLE_NODES
7295 * With no DISCONTIG, the global mem_map is just set as node 0's
7297 if (pgdat
== NODE_DATA(0)) {
7298 mem_map
= NODE_DATA(0)->node_mem_map
;
7299 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
7305 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
7306 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
7308 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
7309 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
)
7311 pgdat
->first_deferred_pfn
= ULONG_MAX
;
7314 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
) {}
7317 static void __init
free_area_init_node(int nid
)
7319 pg_data_t
*pgdat
= NODE_DATA(nid
);
7320 unsigned long start_pfn
= 0;
7321 unsigned long end_pfn
= 0;
7323 /* pg_data_t should be reset to zero when it's allocated */
7324 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_highest_zoneidx
);
7326 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
7328 pgdat
->node_id
= nid
;
7329 pgdat
->node_start_pfn
= start_pfn
;
7330 pgdat
->per_cpu_nodestats
= NULL
;
7332 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
7333 (u64
)start_pfn
<< PAGE_SHIFT
,
7334 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
7335 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
);
7337 alloc_node_mem_map(pgdat
);
7338 pgdat_set_deferred_range(pgdat
);
7340 free_area_init_core(pgdat
);
7343 void __init
free_area_init_memoryless_node(int nid
)
7345 free_area_init_node(nid
);
7348 #if MAX_NUMNODES > 1
7350 * Figure out the number of possible node ids.
7352 void __init
setup_nr_node_ids(void)
7354 unsigned int highest
;
7356 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
7357 nr_node_ids
= highest
+ 1;
7362 * node_map_pfn_alignment - determine the maximum internode alignment
7364 * This function should be called after node map is populated and sorted.
7365 * It calculates the maximum power of two alignment which can distinguish
7368 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7369 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7370 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7371 * shifted, 1GiB is enough and this function will indicate so.
7373 * This is used to test whether pfn -> nid mapping of the chosen memory
7374 * model has fine enough granularity to avoid incorrect mapping for the
7375 * populated node map.
7377 * Return: the determined alignment in pfn's. 0 if there is no alignment
7378 * requirement (single node).
7380 unsigned long __init
node_map_pfn_alignment(void)
7382 unsigned long accl_mask
= 0, last_end
= 0;
7383 unsigned long start
, end
, mask
;
7384 int last_nid
= NUMA_NO_NODE
;
7387 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
7388 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
7395 * Start with a mask granular enough to pin-point to the
7396 * start pfn and tick off bits one-by-one until it becomes
7397 * too coarse to separate the current node from the last.
7399 mask
= ~((1 << __ffs(start
)) - 1);
7400 while (mask
&& last_end
<= (start
& (mask
<< 1)))
7403 /* accumulate all internode masks */
7407 /* convert mask to number of pages */
7408 return ~accl_mask
+ 1;
7412 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7414 * Return: the minimum PFN based on information provided via
7415 * memblock_set_node().
7417 unsigned long __init
find_min_pfn_with_active_regions(void)
7419 return PHYS_PFN(memblock_start_of_DRAM());
7423 * early_calculate_totalpages()
7424 * Sum pages in active regions for movable zone.
7425 * Populate N_MEMORY for calculating usable_nodes.
7427 static unsigned long __init
early_calculate_totalpages(void)
7429 unsigned long totalpages
= 0;
7430 unsigned long start_pfn
, end_pfn
;
7433 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7434 unsigned long pages
= end_pfn
- start_pfn
;
7436 totalpages
+= pages
;
7438 node_set_state(nid
, N_MEMORY
);
7444 * Find the PFN the Movable zone begins in each node. Kernel memory
7445 * is spread evenly between nodes as long as the nodes have enough
7446 * memory. When they don't, some nodes will have more kernelcore than
7449 static void __init
find_zone_movable_pfns_for_nodes(void)
7452 unsigned long usable_startpfn
;
7453 unsigned long kernelcore_node
, kernelcore_remaining
;
7454 /* save the state before borrow the nodemask */
7455 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
7456 unsigned long totalpages
= early_calculate_totalpages();
7457 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
7458 struct memblock_region
*r
;
7460 /* Need to find movable_zone earlier when movable_node is specified. */
7461 find_usable_zone_for_movable();
7464 * If movable_node is specified, ignore kernelcore and movablecore
7467 if (movable_node_is_enabled()) {
7468 for_each_mem_region(r
) {
7469 if (!memblock_is_hotpluggable(r
))
7472 nid
= memblock_get_region_node(r
);
7474 usable_startpfn
= PFN_DOWN(r
->base
);
7475 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7476 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7484 * If kernelcore=mirror is specified, ignore movablecore option
7486 if (mirrored_kernelcore
) {
7487 bool mem_below_4gb_not_mirrored
= false;
7489 for_each_mem_region(r
) {
7490 if (memblock_is_mirror(r
))
7493 nid
= memblock_get_region_node(r
);
7495 usable_startpfn
= memblock_region_memory_base_pfn(r
);
7497 if (usable_startpfn
< 0x100000) {
7498 mem_below_4gb_not_mirrored
= true;
7502 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7503 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7507 if (mem_below_4gb_not_mirrored
)
7508 pr_warn("This configuration results in unmirrored kernel memory.\n");
7514 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7515 * amount of necessary memory.
7517 if (required_kernelcore_percent
)
7518 required_kernelcore
= (totalpages
* 100 * required_kernelcore_percent
) /
7520 if (required_movablecore_percent
)
7521 required_movablecore
= (totalpages
* 100 * required_movablecore_percent
) /
7525 * If movablecore= was specified, calculate what size of
7526 * kernelcore that corresponds so that memory usable for
7527 * any allocation type is evenly spread. If both kernelcore
7528 * and movablecore are specified, then the value of kernelcore
7529 * will be used for required_kernelcore if it's greater than
7530 * what movablecore would have allowed.
7532 if (required_movablecore
) {
7533 unsigned long corepages
;
7536 * Round-up so that ZONE_MOVABLE is at least as large as what
7537 * was requested by the user
7539 required_movablecore
=
7540 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
7541 required_movablecore
= min(totalpages
, required_movablecore
);
7542 corepages
= totalpages
- required_movablecore
;
7544 required_kernelcore
= max(required_kernelcore
, corepages
);
7548 * If kernelcore was not specified or kernelcore size is larger
7549 * than totalpages, there is no ZONE_MOVABLE.
7551 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
7554 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7555 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
7558 /* Spread kernelcore memory as evenly as possible throughout nodes */
7559 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7560 for_each_node_state(nid
, N_MEMORY
) {
7561 unsigned long start_pfn
, end_pfn
;
7564 * Recalculate kernelcore_node if the division per node
7565 * now exceeds what is necessary to satisfy the requested
7566 * amount of memory for the kernel
7568 if (required_kernelcore
< kernelcore_node
)
7569 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7572 * As the map is walked, we track how much memory is usable
7573 * by the kernel using kernelcore_remaining. When it is
7574 * 0, the rest of the node is usable by ZONE_MOVABLE
7576 kernelcore_remaining
= kernelcore_node
;
7578 /* Go through each range of PFNs within this node */
7579 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
7580 unsigned long size_pages
;
7582 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
7583 if (start_pfn
>= end_pfn
)
7586 /* Account for what is only usable for kernelcore */
7587 if (start_pfn
< usable_startpfn
) {
7588 unsigned long kernel_pages
;
7589 kernel_pages
= min(end_pfn
, usable_startpfn
)
7592 kernelcore_remaining
-= min(kernel_pages
,
7593 kernelcore_remaining
);
7594 required_kernelcore
-= min(kernel_pages
,
7595 required_kernelcore
);
7597 /* Continue if range is now fully accounted */
7598 if (end_pfn
<= usable_startpfn
) {
7601 * Push zone_movable_pfn to the end so
7602 * that if we have to rebalance
7603 * kernelcore across nodes, we will
7604 * not double account here
7606 zone_movable_pfn
[nid
] = end_pfn
;
7609 start_pfn
= usable_startpfn
;
7613 * The usable PFN range for ZONE_MOVABLE is from
7614 * start_pfn->end_pfn. Calculate size_pages as the
7615 * number of pages used as kernelcore
7617 size_pages
= end_pfn
- start_pfn
;
7618 if (size_pages
> kernelcore_remaining
)
7619 size_pages
= kernelcore_remaining
;
7620 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
7623 * Some kernelcore has been met, update counts and
7624 * break if the kernelcore for this node has been
7627 required_kernelcore
-= min(required_kernelcore
,
7629 kernelcore_remaining
-= size_pages
;
7630 if (!kernelcore_remaining
)
7636 * If there is still required_kernelcore, we do another pass with one
7637 * less node in the count. This will push zone_movable_pfn[nid] further
7638 * along on the nodes that still have memory until kernelcore is
7642 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
7646 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7647 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
7648 zone_movable_pfn
[nid
] =
7649 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
7652 /* restore the node_state */
7653 node_states
[N_MEMORY
] = saved_node_state
;
7656 /* Any regular or high memory on that node ? */
7657 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
7659 enum zone_type zone_type
;
7661 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
7662 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
7663 if (populated_zone(zone
)) {
7664 if (IS_ENABLED(CONFIG_HIGHMEM
))
7665 node_set_state(nid
, N_HIGH_MEMORY
);
7666 if (zone_type
<= ZONE_NORMAL
)
7667 node_set_state(nid
, N_NORMAL_MEMORY
);
7674 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7675 * such cases we allow max_zone_pfn sorted in the descending order
7677 bool __weak
arch_has_descending_max_zone_pfns(void)
7683 * free_area_init - Initialise all pg_data_t and zone data
7684 * @max_zone_pfn: an array of max PFNs for each zone
7686 * This will call free_area_init_node() for each active node in the system.
7687 * Using the page ranges provided by memblock_set_node(), the size of each
7688 * zone in each node and their holes is calculated. If the maximum PFN
7689 * between two adjacent zones match, it is assumed that the zone is empty.
7690 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7691 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7692 * starts where the previous one ended. For example, ZONE_DMA32 starts
7693 * at arch_max_dma_pfn.
7695 void __init
free_area_init(unsigned long *max_zone_pfn
)
7697 unsigned long start_pfn
, end_pfn
;
7701 /* Record where the zone boundaries are */
7702 memset(arch_zone_lowest_possible_pfn
, 0,
7703 sizeof(arch_zone_lowest_possible_pfn
));
7704 memset(arch_zone_highest_possible_pfn
, 0,
7705 sizeof(arch_zone_highest_possible_pfn
));
7707 start_pfn
= find_min_pfn_with_active_regions();
7708 descending
= arch_has_descending_max_zone_pfns();
7710 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7712 zone
= MAX_NR_ZONES
- i
- 1;
7716 if (zone
== ZONE_MOVABLE
)
7719 end_pfn
= max(max_zone_pfn
[zone
], start_pfn
);
7720 arch_zone_lowest_possible_pfn
[zone
] = start_pfn
;
7721 arch_zone_highest_possible_pfn
[zone
] = end_pfn
;
7723 start_pfn
= end_pfn
;
7726 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7727 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
7728 find_zone_movable_pfns_for_nodes();
7730 /* Print out the zone ranges */
7731 pr_info("Zone ranges:\n");
7732 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7733 if (i
== ZONE_MOVABLE
)
7735 pr_info(" %-8s ", zone_names
[i
]);
7736 if (arch_zone_lowest_possible_pfn
[i
] ==
7737 arch_zone_highest_possible_pfn
[i
])
7740 pr_cont("[mem %#018Lx-%#018Lx]\n",
7741 (u64
)arch_zone_lowest_possible_pfn
[i
]
7743 ((u64
)arch_zone_highest_possible_pfn
[i
]
7744 << PAGE_SHIFT
) - 1);
7747 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7748 pr_info("Movable zone start for each node\n");
7749 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
7750 if (zone_movable_pfn
[i
])
7751 pr_info(" Node %d: %#018Lx\n", i
,
7752 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
7756 * Print out the early node map, and initialize the
7757 * subsection-map relative to active online memory ranges to
7758 * enable future "sub-section" extensions of the memory map.
7760 pr_info("Early memory node ranges\n");
7761 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7762 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
7763 (u64
)start_pfn
<< PAGE_SHIFT
,
7764 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
7765 subsection_map_init(start_pfn
, end_pfn
- start_pfn
);
7768 /* Initialise every node */
7769 mminit_verify_pageflags_layout();
7770 setup_nr_node_ids();
7771 for_each_online_node(nid
) {
7772 pg_data_t
*pgdat
= NODE_DATA(nid
);
7773 free_area_init_node(nid
);
7775 /* Any memory on that node */
7776 if (pgdat
->node_present_pages
)
7777 node_set_state(nid
, N_MEMORY
);
7778 check_for_memory(pgdat
, nid
);
7782 static int __init
cmdline_parse_core(char *p
, unsigned long *core
,
7783 unsigned long *percent
)
7785 unsigned long long coremem
;
7791 /* Value may be a percentage of total memory, otherwise bytes */
7792 coremem
= simple_strtoull(p
, &endptr
, 0);
7793 if (*endptr
== '%') {
7794 /* Paranoid check for percent values greater than 100 */
7795 WARN_ON(coremem
> 100);
7799 coremem
= memparse(p
, &p
);
7800 /* Paranoid check that UL is enough for the coremem value */
7801 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
7803 *core
= coremem
>> PAGE_SHIFT
;
7810 * kernelcore=size sets the amount of memory for use for allocations that
7811 * cannot be reclaimed or migrated.
7813 static int __init
cmdline_parse_kernelcore(char *p
)
7815 /* parse kernelcore=mirror */
7816 if (parse_option_str(p
, "mirror")) {
7817 mirrored_kernelcore
= true;
7821 return cmdline_parse_core(p
, &required_kernelcore
,
7822 &required_kernelcore_percent
);
7826 * movablecore=size sets the amount of memory for use for allocations that
7827 * can be reclaimed or migrated.
7829 static int __init
cmdline_parse_movablecore(char *p
)
7831 return cmdline_parse_core(p
, &required_movablecore
,
7832 &required_movablecore_percent
);
7835 early_param("kernelcore", cmdline_parse_kernelcore
);
7836 early_param("movablecore", cmdline_parse_movablecore
);
7838 void adjust_managed_page_count(struct page
*page
, long count
)
7840 atomic_long_add(count
, &page_zone(page
)->managed_pages
);
7841 totalram_pages_add(count
);
7842 #ifdef CONFIG_HIGHMEM
7843 if (PageHighMem(page
))
7844 totalhigh_pages_add(count
);
7847 EXPORT_SYMBOL(adjust_managed_page_count
);
7849 unsigned long free_reserved_area(void *start
, void *end
, int poison
, const char *s
)
7852 unsigned long pages
= 0;
7854 start
= (void *)PAGE_ALIGN((unsigned long)start
);
7855 end
= (void *)((unsigned long)end
& PAGE_MASK
);
7856 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
7857 struct page
*page
= virt_to_page(pos
);
7858 void *direct_map_addr
;
7861 * 'direct_map_addr' might be different from 'pos'
7862 * because some architectures' virt_to_page()
7863 * work with aliases. Getting the direct map
7864 * address ensures that we get a _writeable_
7865 * alias for the memset().
7867 direct_map_addr
= page_address(page
);
7869 * Perform a kasan-unchecked memset() since this memory
7870 * has not been initialized.
7872 direct_map_addr
= kasan_reset_tag(direct_map_addr
);
7873 if ((unsigned int)poison
<= 0xFF)
7874 memset(direct_map_addr
, poison
, PAGE_SIZE
);
7876 free_reserved_page(page
);
7880 pr_info("Freeing %s memory: %ldK\n",
7881 s
, pages
<< (PAGE_SHIFT
- 10));
7886 void __init
mem_init_print_info(void)
7888 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
7889 unsigned long init_code_size
, init_data_size
;
7891 physpages
= get_num_physpages();
7892 codesize
= _etext
- _stext
;
7893 datasize
= _edata
- _sdata
;
7894 rosize
= __end_rodata
- __start_rodata
;
7895 bss_size
= __bss_stop
- __bss_start
;
7896 init_data_size
= __init_end
- __init_begin
;
7897 init_code_size
= _einittext
- _sinittext
;
7900 * Detect special cases and adjust section sizes accordingly:
7901 * 1) .init.* may be embedded into .data sections
7902 * 2) .init.text.* may be out of [__init_begin, __init_end],
7903 * please refer to arch/tile/kernel/vmlinux.lds.S.
7904 * 3) .rodata.* may be embedded into .text or .data sections.
7906 #define adj_init_size(start, end, size, pos, adj) \
7908 if (start <= pos && pos < end && size > adj) \
7912 adj_init_size(__init_begin
, __init_end
, init_data_size
,
7913 _sinittext
, init_code_size
);
7914 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
7915 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
7916 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
7917 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
7919 #undef adj_init_size
7921 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7922 #ifdef CONFIG_HIGHMEM
7926 nr_free_pages() << (PAGE_SHIFT
- 10),
7927 physpages
<< (PAGE_SHIFT
- 10),
7928 codesize
>> 10, datasize
>> 10, rosize
>> 10,
7929 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
7930 (physpages
- totalram_pages() - totalcma_pages
) << (PAGE_SHIFT
- 10),
7931 totalcma_pages
<< (PAGE_SHIFT
- 10)
7932 #ifdef CONFIG_HIGHMEM
7933 , totalhigh_pages() << (PAGE_SHIFT
- 10)
7939 * set_dma_reserve - set the specified number of pages reserved in the first zone
7940 * @new_dma_reserve: The number of pages to mark reserved
7942 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7943 * In the DMA zone, a significant percentage may be consumed by kernel image
7944 * and other unfreeable allocations which can skew the watermarks badly. This
7945 * function may optionally be used to account for unfreeable pages in the
7946 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7947 * smaller per-cpu batchsize.
7949 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
7951 dma_reserve
= new_dma_reserve
;
7954 static int page_alloc_cpu_dead(unsigned int cpu
)
7957 lru_add_drain_cpu(cpu
);
7961 * Spill the event counters of the dead processor
7962 * into the current processors event counters.
7963 * This artificially elevates the count of the current
7966 vm_events_fold_cpu(cpu
);
7969 * Zero the differential counters of the dead processor
7970 * so that the vm statistics are consistent.
7972 * This is only okay since the processor is dead and cannot
7973 * race with what we are doing.
7975 cpu_vm_stats_fold(cpu
);
7980 int hashdist
= HASHDIST_DEFAULT
;
7982 static int __init
set_hashdist(char *str
)
7986 hashdist
= simple_strtoul(str
, &str
, 0);
7989 __setup("hashdist=", set_hashdist
);
7992 void __init
page_alloc_init(void)
7997 if (num_node_state(N_MEMORY
) == 1)
8001 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
8002 "mm/page_alloc:dead", NULL
,
8003 page_alloc_cpu_dead
);
8008 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
8009 * or min_free_kbytes changes.
8011 static void calculate_totalreserve_pages(void)
8013 struct pglist_data
*pgdat
;
8014 unsigned long reserve_pages
= 0;
8015 enum zone_type i
, j
;
8017 for_each_online_pgdat(pgdat
) {
8019 pgdat
->totalreserve_pages
= 0;
8021 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
8022 struct zone
*zone
= pgdat
->node_zones
+ i
;
8024 unsigned long managed_pages
= zone_managed_pages(zone
);
8026 /* Find valid and maximum lowmem_reserve in the zone */
8027 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
8028 if (zone
->lowmem_reserve
[j
] > max
)
8029 max
= zone
->lowmem_reserve
[j
];
8032 /* we treat the high watermark as reserved pages. */
8033 max
+= high_wmark_pages(zone
);
8035 if (max
> managed_pages
)
8036 max
= managed_pages
;
8038 pgdat
->totalreserve_pages
+= max
;
8040 reserve_pages
+= max
;
8043 totalreserve_pages
= reserve_pages
;
8047 * setup_per_zone_lowmem_reserve - called whenever
8048 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
8049 * has a correct pages reserved value, so an adequate number of
8050 * pages are left in the zone after a successful __alloc_pages().
8052 static void setup_per_zone_lowmem_reserve(void)
8054 struct pglist_data
*pgdat
;
8055 enum zone_type i
, j
;
8057 for_each_online_pgdat(pgdat
) {
8058 for (i
= 0; i
< MAX_NR_ZONES
- 1; i
++) {
8059 struct zone
*zone
= &pgdat
->node_zones
[i
];
8060 int ratio
= sysctl_lowmem_reserve_ratio
[i
];
8061 bool clear
= !ratio
|| !zone_managed_pages(zone
);
8062 unsigned long managed_pages
= 0;
8064 for (j
= i
+ 1; j
< MAX_NR_ZONES
; j
++) {
8066 zone
->lowmem_reserve
[j
] = 0;
8068 struct zone
*upper_zone
= &pgdat
->node_zones
[j
];
8070 managed_pages
+= zone_managed_pages(upper_zone
);
8071 zone
->lowmem_reserve
[j
] = managed_pages
/ ratio
;
8077 /* update totalreserve_pages */
8078 calculate_totalreserve_pages();
8081 static void __setup_per_zone_wmarks(void)
8083 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
8084 unsigned long lowmem_pages
= 0;
8086 unsigned long flags
;
8088 /* Calculate total number of !ZONE_HIGHMEM pages */
8089 for_each_zone(zone
) {
8090 if (!is_highmem(zone
))
8091 lowmem_pages
+= zone_managed_pages(zone
);
8094 for_each_zone(zone
) {
8097 spin_lock_irqsave(&zone
->lock
, flags
);
8098 tmp
= (u64
)pages_min
* zone_managed_pages(zone
);
8099 do_div(tmp
, lowmem_pages
);
8100 if (is_highmem(zone
)) {
8102 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
8103 * need highmem pages, so cap pages_min to a small
8106 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
8107 * deltas control async page reclaim, and so should
8108 * not be capped for highmem.
8110 unsigned long min_pages
;
8112 min_pages
= zone_managed_pages(zone
) / 1024;
8113 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
8114 zone
->_watermark
[WMARK_MIN
] = min_pages
;
8117 * If it's a lowmem zone, reserve a number of pages
8118 * proportionate to the zone's size.
8120 zone
->_watermark
[WMARK_MIN
] = tmp
;
8124 * Set the kswapd watermarks distance according to the
8125 * scale factor in proportion to available memory, but
8126 * ensure a minimum size on small systems.
8128 tmp
= max_t(u64
, tmp
>> 2,
8129 mult_frac(zone_managed_pages(zone
),
8130 watermark_scale_factor
, 10000));
8132 zone
->watermark_boost
= 0;
8133 zone
->_watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
8134 zone
->_watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
8136 spin_unlock_irqrestore(&zone
->lock
, flags
);
8139 /* update totalreserve_pages */
8140 calculate_totalreserve_pages();
8144 * setup_per_zone_wmarks - called when min_free_kbytes changes
8145 * or when memory is hot-{added|removed}
8147 * Ensures that the watermark[min,low,high] values for each zone are set
8148 * correctly with respect to min_free_kbytes.
8150 void setup_per_zone_wmarks(void)
8152 static DEFINE_SPINLOCK(lock
);
8155 __setup_per_zone_wmarks();
8160 * Initialise min_free_kbytes.
8162 * For small machines we want it small (128k min). For large machines
8163 * we want it large (256MB max). But it is not linear, because network
8164 * bandwidth does not increase linearly with machine size. We use
8166 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
8167 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
8183 int __meminit
init_per_zone_wmark_min(void)
8185 unsigned long lowmem_kbytes
;
8186 int new_min_free_kbytes
;
8188 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
8189 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
8191 if (new_min_free_kbytes
> user_min_free_kbytes
) {
8192 min_free_kbytes
= new_min_free_kbytes
;
8193 if (min_free_kbytes
< 128)
8194 min_free_kbytes
= 128;
8195 if (min_free_kbytes
> 262144)
8196 min_free_kbytes
= 262144;
8198 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
8199 new_min_free_kbytes
, user_min_free_kbytes
);
8201 setup_per_zone_wmarks();
8202 refresh_zone_stat_thresholds();
8203 setup_per_zone_lowmem_reserve();
8206 setup_min_unmapped_ratio();
8207 setup_min_slab_ratio();
8210 khugepaged_min_free_kbytes_update();
8214 postcore_initcall(init_per_zone_wmark_min
)
8217 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
8218 * that we can call two helper functions whenever min_free_kbytes
8221 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
8222 void *buffer
, size_t *length
, loff_t
*ppos
)
8226 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8231 user_min_free_kbytes
= min_free_kbytes
;
8232 setup_per_zone_wmarks();
8237 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
8238 void *buffer
, size_t *length
, loff_t
*ppos
)
8242 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8247 setup_per_zone_wmarks();
8253 static void setup_min_unmapped_ratio(void)
8258 for_each_online_pgdat(pgdat
)
8259 pgdat
->min_unmapped_pages
= 0;
8262 zone
->zone_pgdat
->min_unmapped_pages
+= (zone_managed_pages(zone
) *
8263 sysctl_min_unmapped_ratio
) / 100;
8267 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8268 void *buffer
, size_t *length
, loff_t
*ppos
)
8272 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8276 setup_min_unmapped_ratio();
8281 static void setup_min_slab_ratio(void)
8286 for_each_online_pgdat(pgdat
)
8287 pgdat
->min_slab_pages
= 0;
8290 zone
->zone_pgdat
->min_slab_pages
+= (zone_managed_pages(zone
) *
8291 sysctl_min_slab_ratio
) / 100;
8294 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8295 void *buffer
, size_t *length
, loff_t
*ppos
)
8299 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8303 setup_min_slab_ratio();
8310 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8311 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8312 * whenever sysctl_lowmem_reserve_ratio changes.
8314 * The reserve ratio obviously has absolutely no relation with the
8315 * minimum watermarks. The lowmem reserve ratio can only make sense
8316 * if in function of the boot time zone sizes.
8318 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8319 void *buffer
, size_t *length
, loff_t
*ppos
)
8323 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8325 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
8326 if (sysctl_lowmem_reserve_ratio
[i
] < 1)
8327 sysctl_lowmem_reserve_ratio
[i
] = 0;
8330 setup_per_zone_lowmem_reserve();
8335 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8336 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8337 * pagelist can have before it gets flushed back to buddy allocator.
8339 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
8340 void *buffer
, size_t *length
, loff_t
*ppos
)
8343 int old_percpu_pagelist_fraction
;
8346 mutex_lock(&pcp_batch_high_lock
);
8347 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
8349 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8350 if (!write
|| ret
< 0)
8353 /* Sanity checking to avoid pcp imbalance */
8354 if (percpu_pagelist_fraction
&&
8355 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
8356 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
8362 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
8365 for_each_populated_zone(zone
)
8366 zone_set_pageset_high_and_batch(zone
);
8368 mutex_unlock(&pcp_batch_high_lock
);
8372 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8374 * Returns the number of pages that arch has reserved but
8375 * is not known to alloc_large_system_hash().
8377 static unsigned long __init
arch_reserved_kernel_pages(void)
8384 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8385 * machines. As memory size is increased the scale is also increased but at
8386 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8387 * quadruples the scale is increased by one, which means the size of hash table
8388 * only doubles, instead of quadrupling as well.
8389 * Because 32-bit systems cannot have large physical memory, where this scaling
8390 * makes sense, it is disabled on such platforms.
8392 #if __BITS_PER_LONG > 32
8393 #define ADAPT_SCALE_BASE (64ul << 30)
8394 #define ADAPT_SCALE_SHIFT 2
8395 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8399 * allocate a large system hash table from bootmem
8400 * - it is assumed that the hash table must contain an exact power-of-2
8401 * quantity of entries
8402 * - limit is the number of hash buckets, not the total allocation size
8404 void *__init
alloc_large_system_hash(const char *tablename
,
8405 unsigned long bucketsize
,
8406 unsigned long numentries
,
8409 unsigned int *_hash_shift
,
8410 unsigned int *_hash_mask
,
8411 unsigned long low_limit
,
8412 unsigned long high_limit
)
8414 unsigned long long max
= high_limit
;
8415 unsigned long log2qty
, size
;
8421 /* allow the kernel cmdline to have a say */
8423 /* round applicable memory size up to nearest megabyte */
8424 numentries
= nr_kernel_pages
;
8425 numentries
-= arch_reserved_kernel_pages();
8427 /* It isn't necessary when PAGE_SIZE >= 1MB */
8428 if (PAGE_SHIFT
< 20)
8429 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
8431 #if __BITS_PER_LONG > 32
8433 unsigned long adapt
;
8435 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
8436 adapt
<<= ADAPT_SCALE_SHIFT
)
8441 /* limit to 1 bucket per 2^scale bytes of low memory */
8442 if (scale
> PAGE_SHIFT
)
8443 numentries
>>= (scale
- PAGE_SHIFT
);
8445 numentries
<<= (PAGE_SHIFT
- scale
);
8447 /* Make sure we've got at least a 0-order allocation.. */
8448 if (unlikely(flags
& HASH_SMALL
)) {
8449 /* Makes no sense without HASH_EARLY */
8450 WARN_ON(!(flags
& HASH_EARLY
));
8451 if (!(numentries
>> *_hash_shift
)) {
8452 numentries
= 1UL << *_hash_shift
;
8453 BUG_ON(!numentries
);
8455 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
8456 numentries
= PAGE_SIZE
/ bucketsize
;
8458 numentries
= roundup_pow_of_two(numentries
);
8460 /* limit allocation size to 1/16 total memory by default */
8462 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
8463 do_div(max
, bucketsize
);
8465 max
= min(max
, 0x80000000ULL
);
8467 if (numentries
< low_limit
)
8468 numentries
= low_limit
;
8469 if (numentries
> max
)
8472 log2qty
= ilog2(numentries
);
8474 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
8477 size
= bucketsize
<< log2qty
;
8478 if (flags
& HASH_EARLY
) {
8479 if (flags
& HASH_ZERO
)
8480 table
= memblock_alloc(size
, SMP_CACHE_BYTES
);
8482 table
= memblock_alloc_raw(size
,
8484 } else if (get_order(size
) >= MAX_ORDER
|| hashdist
) {
8485 table
= __vmalloc(size
, gfp_flags
);
8487 huge
= is_vm_area_hugepages(table
);
8490 * If bucketsize is not a power-of-two, we may free
8491 * some pages at the end of hash table which
8492 * alloc_pages_exact() automatically does
8494 table
= alloc_pages_exact(size
, gfp_flags
);
8495 kmemleak_alloc(table
, size
, 1, gfp_flags
);
8497 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
8500 panic("Failed to allocate %s hash table\n", tablename
);
8502 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8503 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
,
8504 virt
? (huge
? "vmalloc hugepage" : "vmalloc") : "linear");
8507 *_hash_shift
= log2qty
;
8509 *_hash_mask
= (1 << log2qty
) - 1;
8515 * This function checks whether pageblock includes unmovable pages or not.
8517 * PageLRU check without isolation or lru_lock could race so that
8518 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8519 * check without lock_page also may miss some movable non-lru pages at
8520 * race condition. So you can't expect this function should be exact.
8522 * Returns a page without holding a reference. If the caller wants to
8523 * dereference that page (e.g., dumping), it has to make sure that it
8524 * cannot get removed (e.g., via memory unplug) concurrently.
8527 struct page
*has_unmovable_pages(struct zone
*zone
, struct page
*page
,
8528 int migratetype
, int flags
)
8530 unsigned long iter
= 0;
8531 unsigned long pfn
= page_to_pfn(page
);
8532 unsigned long offset
= pfn
% pageblock_nr_pages
;
8534 if (is_migrate_cma_page(page
)) {
8536 * CMA allocations (alloc_contig_range) really need to mark
8537 * isolate CMA pageblocks even when they are not movable in fact
8538 * so consider them movable here.
8540 if (is_migrate_cma(migratetype
))
8546 for (; iter
< pageblock_nr_pages
- offset
; iter
++) {
8547 if (!pfn_valid_within(pfn
+ iter
))
8550 page
= pfn_to_page(pfn
+ iter
);
8553 * Both, bootmem allocations and memory holes are marked
8554 * PG_reserved and are unmovable. We can even have unmovable
8555 * allocations inside ZONE_MOVABLE, for example when
8556 * specifying "movablecore".
8558 if (PageReserved(page
))
8562 * If the zone is movable and we have ruled out all reserved
8563 * pages then it should be reasonably safe to assume the rest
8566 if (zone_idx(zone
) == ZONE_MOVABLE
)
8570 * Hugepages are not in LRU lists, but they're movable.
8571 * THPs are on the LRU, but need to be counted as #small pages.
8572 * We need not scan over tail pages because we don't
8573 * handle each tail page individually in migration.
8575 if (PageHuge(page
) || PageTransCompound(page
)) {
8576 struct page
*head
= compound_head(page
);
8577 unsigned int skip_pages
;
8579 if (PageHuge(page
)) {
8580 if (!hugepage_migration_supported(page_hstate(head
)))
8582 } else if (!PageLRU(head
) && !__PageMovable(head
)) {
8586 skip_pages
= compound_nr(head
) - (page
- head
);
8587 iter
+= skip_pages
- 1;
8592 * We can't use page_count without pin a page
8593 * because another CPU can free compound page.
8594 * This check already skips compound tails of THP
8595 * because their page->_refcount is zero at all time.
8597 if (!page_ref_count(page
)) {
8598 if (PageBuddy(page
))
8599 iter
+= (1 << buddy_order(page
)) - 1;
8604 * The HWPoisoned page may be not in buddy system, and
8605 * page_count() is not 0.
8607 if ((flags
& MEMORY_OFFLINE
) && PageHWPoison(page
))
8611 * We treat all PageOffline() pages as movable when offlining
8612 * to give drivers a chance to decrement their reference count
8613 * in MEM_GOING_OFFLINE in order to indicate that these pages
8614 * can be offlined as there are no direct references anymore.
8615 * For actually unmovable PageOffline() where the driver does
8616 * not support this, we will fail later when trying to actually
8617 * move these pages that still have a reference count > 0.
8618 * (false negatives in this function only)
8620 if ((flags
& MEMORY_OFFLINE
) && PageOffline(page
))
8623 if (__PageMovable(page
) || PageLRU(page
))
8627 * If there are RECLAIMABLE pages, we need to check
8628 * it. But now, memory offline itself doesn't call
8629 * shrink_node_slabs() and it still to be fixed.
8636 #ifdef CONFIG_CONTIG_ALLOC
8637 static unsigned long pfn_max_align_down(unsigned long pfn
)
8639 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8640 pageblock_nr_pages
) - 1);
8643 static unsigned long pfn_max_align_up(unsigned long pfn
)
8645 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8646 pageblock_nr_pages
));
8649 #if defined(CONFIG_DYNAMIC_DEBUG) || \
8650 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
8651 /* Usage: See admin-guide/dynamic-debug-howto.rst */
8652 static void alloc_contig_dump_pages(struct list_head
*page_list
)
8654 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor
, "migrate failure");
8656 if (DYNAMIC_DEBUG_BRANCH(descriptor
)) {
8660 list_for_each_entry(page
, page_list
, lru
)
8661 dump_page(page
, "migration failure");
8665 static inline void alloc_contig_dump_pages(struct list_head
*page_list
)
8670 /* [start, end) must belong to a single zone. */
8671 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
8672 unsigned long start
, unsigned long end
)
8674 /* This function is based on compact_zone() from compaction.c. */
8675 unsigned int nr_reclaimed
;
8676 unsigned long pfn
= start
;
8677 unsigned int tries
= 0;
8679 struct migration_target_control mtc
= {
8680 .nid
= zone_to_nid(cc
->zone
),
8681 .gfp_mask
= GFP_USER
| __GFP_MOVABLE
| __GFP_RETRY_MAYFAIL
,
8686 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
8687 if (fatal_signal_pending(current
)) {
8692 if (list_empty(&cc
->migratepages
)) {
8693 cc
->nr_migratepages
= 0;
8694 ret
= isolate_migratepages_range(cc
, pfn
, end
);
8695 if (ret
&& ret
!= -EAGAIN
)
8697 pfn
= cc
->migrate_pfn
;
8699 } else if (++tries
== 5) {
8704 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
8706 cc
->nr_migratepages
-= nr_reclaimed
;
8708 ret
= migrate_pages(&cc
->migratepages
, alloc_migration_target
,
8709 NULL
, (unsigned long)&mtc
, cc
->mode
, MR_CONTIG_RANGE
);
8712 * On -ENOMEM, migrate_pages() bails out right away. It is pointless
8713 * to retry again over this error, so do the same here.
8719 alloc_contig_dump_pages(&cc
->migratepages
);
8720 putback_movable_pages(&cc
->migratepages
);
8727 * alloc_contig_range() -- tries to allocate given range of pages
8728 * @start: start PFN to allocate
8729 * @end: one-past-the-last PFN to allocate
8730 * @migratetype: migratetype of the underlaying pageblocks (either
8731 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8732 * in range must have the same migratetype and it must
8733 * be either of the two.
8734 * @gfp_mask: GFP mask to use during compaction
8736 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8737 * aligned. The PFN range must belong to a single zone.
8739 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8740 * pageblocks in the range. Once isolated, the pageblocks should not
8741 * be modified by others.
8743 * Return: zero on success or negative error code. On success all
8744 * pages which PFN is in [start, end) are allocated for the caller and
8745 * need to be freed with free_contig_range().
8747 int alloc_contig_range(unsigned long start
, unsigned long end
,
8748 unsigned migratetype
, gfp_t gfp_mask
)
8750 unsigned long outer_start
, outer_end
;
8754 struct compact_control cc
= {
8755 .nr_migratepages
= 0,
8757 .zone
= page_zone(pfn_to_page(start
)),
8758 .mode
= MIGRATE_SYNC
,
8759 .ignore_skip_hint
= true,
8760 .no_set_skip_hint
= true,
8761 .gfp_mask
= current_gfp_context(gfp_mask
),
8762 .alloc_contig
= true,
8764 INIT_LIST_HEAD(&cc
.migratepages
);
8767 * What we do here is we mark all pageblocks in range as
8768 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8769 * have different sizes, and due to the way page allocator
8770 * work, we align the range to biggest of the two pages so
8771 * that page allocator won't try to merge buddies from
8772 * different pageblocks and change MIGRATE_ISOLATE to some
8773 * other migration type.
8775 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8776 * migrate the pages from an unaligned range (ie. pages that
8777 * we are interested in). This will put all the pages in
8778 * range back to page allocator as MIGRATE_ISOLATE.
8780 * When this is done, we take the pages in range from page
8781 * allocator removing them from the buddy system. This way
8782 * page allocator will never consider using them.
8784 * This lets us mark the pageblocks back as
8785 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8786 * aligned range but not in the unaligned, original range are
8787 * put back to page allocator so that buddy can use them.
8790 ret
= start_isolate_page_range(pfn_max_align_down(start
),
8791 pfn_max_align_up(end
), migratetype
, 0);
8795 drain_all_pages(cc
.zone
);
8798 * In case of -EBUSY, we'd like to know which page causes problem.
8799 * So, just fall through. test_pages_isolated() has a tracepoint
8800 * which will report the busy page.
8802 * It is possible that busy pages could become available before
8803 * the call to test_pages_isolated, and the range will actually be
8804 * allocated. So, if we fall through be sure to clear ret so that
8805 * -EBUSY is not accidentally used or returned to caller.
8807 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
8808 if (ret
&& ret
!= -EBUSY
)
8813 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8814 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8815 * more, all pages in [start, end) are free in page allocator.
8816 * What we are going to do is to allocate all pages from
8817 * [start, end) (that is remove them from page allocator).
8819 * The only problem is that pages at the beginning and at the
8820 * end of interesting range may be not aligned with pages that
8821 * page allocator holds, ie. they can be part of higher order
8822 * pages. Because of this, we reserve the bigger range and
8823 * once this is done free the pages we are not interested in.
8825 * We don't have to hold zone->lock here because the pages are
8826 * isolated thus they won't get removed from buddy.
8830 outer_start
= start
;
8831 while (!PageBuddy(pfn_to_page(outer_start
))) {
8832 if (++order
>= MAX_ORDER
) {
8833 outer_start
= start
;
8836 outer_start
&= ~0UL << order
;
8839 if (outer_start
!= start
) {
8840 order
= buddy_order(pfn_to_page(outer_start
));
8843 * outer_start page could be small order buddy page and
8844 * it doesn't include start page. Adjust outer_start
8845 * in this case to report failed page properly
8846 * on tracepoint in test_pages_isolated()
8848 if (outer_start
+ (1UL << order
) <= start
)
8849 outer_start
= start
;
8852 /* Make sure the range is really isolated. */
8853 if (test_pages_isolated(outer_start
, end
, 0)) {
8858 /* Grab isolated pages from freelists. */
8859 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
8865 /* Free head and tail (if any) */
8866 if (start
!= outer_start
)
8867 free_contig_range(outer_start
, start
- outer_start
);
8868 if (end
!= outer_end
)
8869 free_contig_range(end
, outer_end
- end
);
8872 undo_isolate_page_range(pfn_max_align_down(start
),
8873 pfn_max_align_up(end
), migratetype
);
8876 EXPORT_SYMBOL(alloc_contig_range
);
8878 static int __alloc_contig_pages(unsigned long start_pfn
,
8879 unsigned long nr_pages
, gfp_t gfp_mask
)
8881 unsigned long end_pfn
= start_pfn
+ nr_pages
;
8883 return alloc_contig_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
,
8887 static bool pfn_range_valid_contig(struct zone
*z
, unsigned long start_pfn
,
8888 unsigned long nr_pages
)
8890 unsigned long i
, end_pfn
= start_pfn
+ nr_pages
;
8893 for (i
= start_pfn
; i
< end_pfn
; i
++) {
8894 page
= pfn_to_online_page(i
);
8898 if (page_zone(page
) != z
)
8901 if (PageReserved(page
))
8907 static bool zone_spans_last_pfn(const struct zone
*zone
,
8908 unsigned long start_pfn
, unsigned long nr_pages
)
8910 unsigned long last_pfn
= start_pfn
+ nr_pages
- 1;
8912 return zone_spans_pfn(zone
, last_pfn
);
8916 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8917 * @nr_pages: Number of contiguous pages to allocate
8918 * @gfp_mask: GFP mask to limit search and used during compaction
8920 * @nodemask: Mask for other possible nodes
8922 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8923 * on an applicable zonelist to find a contiguous pfn range which can then be
8924 * tried for allocation with alloc_contig_range(). This routine is intended
8925 * for allocation requests which can not be fulfilled with the buddy allocator.
8927 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8928 * power of two then the alignment is guaranteed to be to the given nr_pages
8929 * (e.g. 1GB request would be aligned to 1GB).
8931 * Allocated pages can be freed with free_contig_range() or by manually calling
8932 * __free_page() on each allocated page.
8934 * Return: pointer to contiguous pages on success, or NULL if not successful.
8936 struct page
*alloc_contig_pages(unsigned long nr_pages
, gfp_t gfp_mask
,
8937 int nid
, nodemask_t
*nodemask
)
8939 unsigned long ret
, pfn
, flags
;
8940 struct zonelist
*zonelist
;
8944 zonelist
= node_zonelist(nid
, gfp_mask
);
8945 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
8946 gfp_zone(gfp_mask
), nodemask
) {
8947 spin_lock_irqsave(&zone
->lock
, flags
);
8949 pfn
= ALIGN(zone
->zone_start_pfn
, nr_pages
);
8950 while (zone_spans_last_pfn(zone
, pfn
, nr_pages
)) {
8951 if (pfn_range_valid_contig(zone
, pfn
, nr_pages
)) {
8953 * We release the zone lock here because
8954 * alloc_contig_range() will also lock the zone
8955 * at some point. If there's an allocation
8956 * spinning on this lock, it may win the race
8957 * and cause alloc_contig_range() to fail...
8959 spin_unlock_irqrestore(&zone
->lock
, flags
);
8960 ret
= __alloc_contig_pages(pfn
, nr_pages
,
8963 return pfn_to_page(pfn
);
8964 spin_lock_irqsave(&zone
->lock
, flags
);
8968 spin_unlock_irqrestore(&zone
->lock
, flags
);
8972 #endif /* CONFIG_CONTIG_ALLOC */
8974 void free_contig_range(unsigned long pfn
, unsigned int nr_pages
)
8976 unsigned int count
= 0;
8978 for (; nr_pages
--; pfn
++) {
8979 struct page
*page
= pfn_to_page(pfn
);
8981 count
+= page_count(page
) != 1;
8984 WARN(count
!= 0, "%d pages are still in use!\n", count
);
8986 EXPORT_SYMBOL(free_contig_range
);
8989 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8990 * page high values need to be recalulated.
8992 void __meminit
zone_pcp_update(struct zone
*zone
)
8994 mutex_lock(&pcp_batch_high_lock
);
8995 zone_set_pageset_high_and_batch(zone
);
8996 mutex_unlock(&pcp_batch_high_lock
);
9000 * Effectively disable pcplists for the zone by setting the high limit to 0
9001 * and draining all cpus. A concurrent page freeing on another CPU that's about
9002 * to put the page on pcplist will either finish before the drain and the page
9003 * will be drained, or observe the new high limit and skip the pcplist.
9005 * Must be paired with a call to zone_pcp_enable().
9007 void zone_pcp_disable(struct zone
*zone
)
9009 mutex_lock(&pcp_batch_high_lock
);
9010 __zone_set_pageset_high_and_batch(zone
, 0, 1);
9011 __drain_all_pages(zone
, true);
9014 void zone_pcp_enable(struct zone
*zone
)
9016 __zone_set_pageset_high_and_batch(zone
, zone
->pageset_high
, zone
->pageset_batch
);
9017 mutex_unlock(&pcp_batch_high_lock
);
9020 void zone_pcp_reset(struct zone
*zone
)
9022 unsigned long flags
;
9024 struct per_cpu_pageset
*pset
;
9026 /* avoid races with drain_pages() */
9027 local_irq_save(flags
);
9028 if (zone
->pageset
!= &boot_pageset
) {
9029 for_each_online_cpu(cpu
) {
9030 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
9031 drain_zonestat(zone
, pset
);
9033 free_percpu(zone
->pageset
);
9034 zone
->pageset
= &boot_pageset
;
9036 local_irq_restore(flags
);
9039 #ifdef CONFIG_MEMORY_HOTREMOVE
9041 * All pages in the range must be in a single zone, must not contain holes,
9042 * must span full sections, and must be isolated before calling this function.
9044 void __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
9046 unsigned long pfn
= start_pfn
;
9050 unsigned long flags
;
9052 offline_mem_sections(pfn
, end_pfn
);
9053 zone
= page_zone(pfn_to_page(pfn
));
9054 spin_lock_irqsave(&zone
->lock
, flags
);
9055 while (pfn
< end_pfn
) {
9056 page
= pfn_to_page(pfn
);
9058 * The HWPoisoned page may be not in buddy system, and
9059 * page_count() is not 0.
9061 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
9066 * At this point all remaining PageOffline() pages have a
9067 * reference count of 0 and can simply be skipped.
9069 if (PageOffline(page
)) {
9070 BUG_ON(page_count(page
));
9071 BUG_ON(PageBuddy(page
));
9076 BUG_ON(page_count(page
));
9077 BUG_ON(!PageBuddy(page
));
9078 order
= buddy_order(page
);
9079 del_page_from_free_list(page
, zone
, order
);
9080 pfn
+= (1 << order
);
9082 spin_unlock_irqrestore(&zone
->lock
, flags
);
9086 bool is_free_buddy_page(struct page
*page
)
9088 struct zone
*zone
= page_zone(page
);
9089 unsigned long pfn
= page_to_pfn(page
);
9090 unsigned long flags
;
9093 spin_lock_irqsave(&zone
->lock
, flags
);
9094 for (order
= 0; order
< MAX_ORDER
; order
++) {
9095 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
9097 if (PageBuddy(page_head
) && buddy_order(page_head
) >= order
)
9100 spin_unlock_irqrestore(&zone
->lock
, flags
);
9102 return order
< MAX_ORDER
;
9105 #ifdef CONFIG_MEMORY_FAILURE
9107 * Break down a higher-order page in sub-pages, and keep our target out of
9110 static void break_down_buddy_pages(struct zone
*zone
, struct page
*page
,
9111 struct page
*target
, int low
, int high
,
9114 unsigned long size
= 1 << high
;
9115 struct page
*current_buddy
, *next_page
;
9117 while (high
> low
) {
9121 if (target
>= &page
[size
]) {
9122 next_page
= page
+ size
;
9123 current_buddy
= page
;
9126 current_buddy
= page
+ size
;
9129 if (set_page_guard(zone
, current_buddy
, high
, migratetype
))
9132 if (current_buddy
!= target
) {
9133 add_to_free_list(current_buddy
, zone
, high
, migratetype
);
9134 set_buddy_order(current_buddy
, high
);
9141 * Take a page that will be marked as poisoned off the buddy allocator.
9143 bool take_page_off_buddy(struct page
*page
)
9145 struct zone
*zone
= page_zone(page
);
9146 unsigned long pfn
= page_to_pfn(page
);
9147 unsigned long flags
;
9151 spin_lock_irqsave(&zone
->lock
, flags
);
9152 for (order
= 0; order
< MAX_ORDER
; order
++) {
9153 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
9154 int page_order
= buddy_order(page_head
);
9156 if (PageBuddy(page_head
) && page_order
>= order
) {
9157 unsigned long pfn_head
= page_to_pfn(page_head
);
9158 int migratetype
= get_pfnblock_migratetype(page_head
,
9161 del_page_from_free_list(page_head
, zone
, page_order
);
9162 break_down_buddy_pages(zone
, page_head
, page
, 0,
9163 page_order
, migratetype
);
9167 if (page_count(page_head
) > 0)
9170 spin_unlock_irqrestore(&zone
->lock
, flags
);