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>
76 #include <asm/sections.h>
77 #include <asm/tlbflush.h>
78 #include <asm/div64.h>
81 #include "page_reporting.h"
83 /* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
84 typedef int __bitwise fpi_t
;
86 /* No special request */
87 #define FPI_NONE ((__force fpi_t)0)
90 * Skip free page reporting notification for the (possibly merged) page.
91 * This does not hinder free page reporting from grabbing the page,
92 * reporting it and marking it "reported" - it only skips notifying
93 * the free page reporting infrastructure about a newly freed page. For
94 * example, used when temporarily pulling a page from a freelist and
95 * putting it back unmodified.
97 #define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0))
100 * Place the (possibly merged) page to the tail of the freelist. Will ignore
101 * page shuffling (relevant code - e.g., memory onlining - is expected to
102 * shuffle the whole zone).
104 * Note: No code should rely on this flag for correctness - it's purely
105 * to allow for optimizations when handing back either fresh pages
106 * (memory onlining) or untouched pages (page isolation, free page
109 #define FPI_TO_TAIL ((__force fpi_t)BIT(1))
111 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
112 static DEFINE_MUTEX(pcp_batch_high_lock
);
113 #define MIN_PERCPU_PAGELIST_FRACTION (8)
115 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
116 DEFINE_PER_CPU(int, numa_node
);
117 EXPORT_PER_CPU_SYMBOL(numa_node
);
120 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
122 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
124 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
125 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
126 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
127 * defined in <linux/topology.h>.
129 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
130 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
133 /* work_structs for global per-cpu drains */
136 struct work_struct work
;
138 static DEFINE_MUTEX(pcpu_drain_mutex
);
139 static DEFINE_PER_CPU(struct pcpu_drain
, pcpu_drain
);
141 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
142 volatile unsigned long latent_entropy __latent_entropy
;
143 EXPORT_SYMBOL(latent_entropy
);
147 * Array of node states.
149 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
150 [N_POSSIBLE
] = NODE_MASK_ALL
,
151 [N_ONLINE
] = { { [0] = 1UL } },
153 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
154 #ifdef CONFIG_HIGHMEM
155 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
157 [N_MEMORY
] = { { [0] = 1UL } },
158 [N_CPU
] = { { [0] = 1UL } },
161 EXPORT_SYMBOL(node_states
);
163 atomic_long_t _totalram_pages __read_mostly
;
164 EXPORT_SYMBOL(_totalram_pages
);
165 unsigned long totalreserve_pages __read_mostly
;
166 unsigned long totalcma_pages __read_mostly
;
168 int percpu_pagelist_fraction
;
169 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
170 DEFINE_STATIC_KEY_FALSE(init_on_alloc
);
171 EXPORT_SYMBOL(init_on_alloc
);
173 DEFINE_STATIC_KEY_FALSE(init_on_free
);
174 EXPORT_SYMBOL(init_on_free
);
176 static bool _init_on_alloc_enabled_early __read_mostly
177 = IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON
);
178 static int __init
early_init_on_alloc(char *buf
)
181 return kstrtobool(buf
, &_init_on_alloc_enabled_early
);
183 early_param("init_on_alloc", early_init_on_alloc
);
185 static bool _init_on_free_enabled_early __read_mostly
186 = IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON
);
187 static int __init
early_init_on_free(char *buf
)
189 return kstrtobool(buf
, &_init_on_free_enabled_early
);
191 early_param("init_on_free", early_init_on_free
);
194 * A cached value of the page's pageblock's migratetype, used when the page is
195 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
196 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
197 * Also the migratetype set in the page does not necessarily match the pcplist
198 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
199 * other index - this ensures that it will be put on the correct CMA freelist.
201 static inline int get_pcppage_migratetype(struct page
*page
)
206 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
208 page
->index
= migratetype
;
211 #ifdef CONFIG_PM_SLEEP
213 * The following functions are used by the suspend/hibernate code to temporarily
214 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
215 * while devices are suspended. To avoid races with the suspend/hibernate code,
216 * they should always be called with system_transition_mutex held
217 * (gfp_allowed_mask also should only be modified with system_transition_mutex
218 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
219 * with that modification).
222 static gfp_t saved_gfp_mask
;
224 void pm_restore_gfp_mask(void)
226 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
227 if (saved_gfp_mask
) {
228 gfp_allowed_mask
= saved_gfp_mask
;
233 void pm_restrict_gfp_mask(void)
235 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
236 WARN_ON(saved_gfp_mask
);
237 saved_gfp_mask
= gfp_allowed_mask
;
238 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
241 bool pm_suspended_storage(void)
243 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
247 #endif /* CONFIG_PM_SLEEP */
249 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
250 unsigned int pageblock_order __read_mostly
;
253 static void __free_pages_ok(struct page
*page
, unsigned int order
,
257 * results with 256, 32 in the lowmem_reserve sysctl:
258 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
259 * 1G machine -> (16M dma, 784M normal, 224M high)
260 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
261 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
262 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
264 * TBD: should special case ZONE_DMA32 machines here - in those we normally
265 * don't need any ZONE_NORMAL reservation
267 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
] = {
268 #ifdef CONFIG_ZONE_DMA
271 #ifdef CONFIG_ZONE_DMA32
275 #ifdef CONFIG_HIGHMEM
281 static char * const zone_names
[MAX_NR_ZONES
] = {
282 #ifdef CONFIG_ZONE_DMA
285 #ifdef CONFIG_ZONE_DMA32
289 #ifdef CONFIG_HIGHMEM
293 #ifdef CONFIG_ZONE_DEVICE
298 const char * const migratetype_names
[MIGRATE_TYPES
] = {
306 #ifdef CONFIG_MEMORY_ISOLATION
311 compound_page_dtor
* const compound_page_dtors
[NR_COMPOUND_DTORS
] = {
312 [NULL_COMPOUND_DTOR
] = NULL
,
313 [COMPOUND_PAGE_DTOR
] = free_compound_page
,
314 #ifdef CONFIG_HUGETLB_PAGE
315 [HUGETLB_PAGE_DTOR
] = free_huge_page
,
317 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
318 [TRANSHUGE_PAGE_DTOR
] = free_transhuge_page
,
322 int min_free_kbytes
= 1024;
323 int user_min_free_kbytes
= -1;
324 int watermark_boost_factor __read_mostly
;
325 int watermark_scale_factor
= 10;
327 static unsigned long nr_kernel_pages __initdata
;
328 static unsigned long nr_all_pages __initdata
;
329 static unsigned long dma_reserve __initdata
;
331 static unsigned long arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
332 static unsigned long arch_zone_highest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
333 static unsigned long required_kernelcore __initdata
;
334 static unsigned long required_kernelcore_percent __initdata
;
335 static unsigned long required_movablecore __initdata
;
336 static unsigned long required_movablecore_percent __initdata
;
337 static unsigned long zone_movable_pfn
[MAX_NUMNODES
] __initdata
;
338 static bool mirrored_kernelcore __meminitdata
;
340 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
342 EXPORT_SYMBOL(movable_zone
);
345 unsigned int nr_node_ids __read_mostly
= MAX_NUMNODES
;
346 unsigned int nr_online_nodes __read_mostly
= 1;
347 EXPORT_SYMBOL(nr_node_ids
);
348 EXPORT_SYMBOL(nr_online_nodes
);
351 int page_group_by_mobility_disabled __read_mostly
;
353 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
355 * During boot we initialize deferred pages on-demand, as needed, but once
356 * page_alloc_init_late() has finished, the deferred pages are all initialized,
357 * and we can permanently disable that path.
359 static DEFINE_STATIC_KEY_TRUE(deferred_pages
);
362 * Calling kasan_free_pages() only after deferred memory initialization
363 * has completed. Poisoning pages during deferred memory init will greatly
364 * lengthen the process and cause problem in large memory systems as the
365 * deferred pages initialization is done with interrupt disabled.
367 * Assuming that there will be no reference to those newly initialized
368 * pages before they are ever allocated, this should have no effect on
369 * KASAN memory tracking as the poison will be properly inserted at page
370 * allocation time. The only corner case is when pages are allocated by
371 * on-demand allocation and then freed again before the deferred pages
372 * initialization is done, but this is not likely to happen.
374 static inline void kasan_free_nondeferred_pages(struct page
*page
, int order
)
376 if (!static_branch_unlikely(&deferred_pages
))
377 kasan_free_pages(page
, order
);
380 /* Returns true if the struct page for the pfn is uninitialised */
381 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
383 int nid
= early_pfn_to_nid(pfn
);
385 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
392 * Returns true when the remaining initialisation should be deferred until
393 * later in the boot cycle when it can be parallelised.
395 static bool __meminit
396 defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
398 static unsigned long prev_end_pfn
, nr_initialised
;
401 * prev_end_pfn static that contains the end of previous zone
402 * No need to protect because called very early in boot before smp_init.
404 if (prev_end_pfn
!= end_pfn
) {
405 prev_end_pfn
= end_pfn
;
409 /* Always populate low zones for address-constrained allocations */
410 if (end_pfn
< pgdat_end_pfn(NODE_DATA(nid
)))
413 if (NODE_DATA(nid
)->first_deferred_pfn
!= ULONG_MAX
)
416 * We start only with one section of pages, more pages are added as
417 * needed until the rest of deferred pages are initialized.
420 if ((nr_initialised
> PAGES_PER_SECTION
) &&
421 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
422 NODE_DATA(nid
)->first_deferred_pfn
= pfn
;
428 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
430 static inline bool early_page_uninitialised(unsigned long pfn
)
435 static inline bool defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
441 /* Return a pointer to the bitmap storing bits affecting a block of pages */
442 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
445 #ifdef CONFIG_SPARSEMEM
446 return section_to_usemap(__pfn_to_section(pfn
));
448 return page_zone(page
)->pageblock_flags
;
449 #endif /* CONFIG_SPARSEMEM */
452 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
454 #ifdef CONFIG_SPARSEMEM
455 pfn
&= (PAGES_PER_SECTION
-1);
457 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
458 #endif /* CONFIG_SPARSEMEM */
459 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
462 static __always_inline
463 unsigned long __get_pfnblock_flags_mask(struct page
*page
,
467 unsigned long *bitmap
;
468 unsigned long bitidx
, word_bitidx
;
471 bitmap
= get_pageblock_bitmap(page
, pfn
);
472 bitidx
= pfn_to_bitidx(page
, pfn
);
473 word_bitidx
= bitidx
/ BITS_PER_LONG
;
474 bitidx
&= (BITS_PER_LONG
-1);
476 word
= bitmap
[word_bitidx
];
477 return (word
>> bitidx
) & mask
;
481 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
482 * @page: The page within the block of interest
483 * @pfn: The target page frame number
484 * @mask: mask of bits that the caller is interested in
486 * Return: pageblock_bits flags
488 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
491 return __get_pfnblock_flags_mask(page
, pfn
, mask
);
494 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
496 return __get_pfnblock_flags_mask(page
, pfn
, MIGRATETYPE_MASK
);
500 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
501 * @page: The page within the block of interest
502 * @flags: The flags to set
503 * @pfn: The target page frame number
504 * @mask: mask of bits that the caller is interested in
506 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
510 unsigned long *bitmap
;
511 unsigned long bitidx
, word_bitidx
;
512 unsigned long old_word
, word
;
514 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
515 BUILD_BUG_ON(MIGRATE_TYPES
> (1 << PB_migratetype_bits
));
517 bitmap
= get_pageblock_bitmap(page
, pfn
);
518 bitidx
= pfn_to_bitidx(page
, pfn
);
519 word_bitidx
= bitidx
/ BITS_PER_LONG
;
520 bitidx
&= (BITS_PER_LONG
-1);
522 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
527 word
= READ_ONCE(bitmap
[word_bitidx
]);
529 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
530 if (word
== old_word
)
536 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
538 if (unlikely(page_group_by_mobility_disabled
&&
539 migratetype
< MIGRATE_PCPTYPES
))
540 migratetype
= MIGRATE_UNMOVABLE
;
542 set_pfnblock_flags_mask(page
, (unsigned long)migratetype
,
543 page_to_pfn(page
), MIGRATETYPE_MASK
);
546 #ifdef CONFIG_DEBUG_VM
547 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
551 unsigned long pfn
= page_to_pfn(page
);
552 unsigned long sp
, start_pfn
;
555 seq
= zone_span_seqbegin(zone
);
556 start_pfn
= zone
->zone_start_pfn
;
557 sp
= zone
->spanned_pages
;
558 if (!zone_spans_pfn(zone
, pfn
))
560 } while (zone_span_seqretry(zone
, seq
));
563 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
564 pfn
, zone_to_nid(zone
), zone
->name
,
565 start_pfn
, start_pfn
+ sp
);
570 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
572 if (!pfn_valid_within(page_to_pfn(page
)))
574 if (zone
!= page_zone(page
))
580 * Temporary debugging check for pages not lying within a given zone.
582 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
584 if (page_outside_zone_boundaries(zone
, page
))
586 if (!page_is_consistent(zone
, page
))
592 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
598 static void bad_page(struct page
*page
, const char *reason
)
600 static unsigned long resume
;
601 static unsigned long nr_shown
;
602 static unsigned long nr_unshown
;
605 * Allow a burst of 60 reports, then keep quiet for that minute;
606 * or allow a steady drip of one report per second.
608 if (nr_shown
== 60) {
609 if (time_before(jiffies
, resume
)) {
615 "BUG: Bad page state: %lu messages suppressed\n",
622 resume
= jiffies
+ 60 * HZ
;
624 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
625 current
->comm
, page_to_pfn(page
));
626 __dump_page(page
, reason
);
627 dump_page_owner(page
);
632 /* Leave bad fields for debug, except PageBuddy could make trouble */
633 page_mapcount_reset(page
); /* remove PageBuddy */
634 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
638 * Higher-order pages are called "compound pages". They are structured thusly:
640 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
642 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
643 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
645 * The first tail page's ->compound_dtor holds the offset in array of compound
646 * page destructors. See compound_page_dtors.
648 * The first tail page's ->compound_order holds the order of allocation.
649 * This usage means that zero-order pages may not be compound.
652 void free_compound_page(struct page
*page
)
654 mem_cgroup_uncharge(page
);
655 __free_pages_ok(page
, compound_order(page
), FPI_NONE
);
658 void prep_compound_page(struct page
*page
, unsigned int order
)
661 int nr_pages
= 1 << order
;
664 for (i
= 1; i
< nr_pages
; i
++) {
665 struct page
*p
= page
+ i
;
666 set_page_count(p
, 0);
667 p
->mapping
= TAIL_MAPPING
;
668 set_compound_head(p
, page
);
671 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
672 set_compound_order(page
, order
);
673 atomic_set(compound_mapcount_ptr(page
), -1);
674 if (hpage_pincount_available(page
))
675 atomic_set(compound_pincount_ptr(page
), 0);
678 #ifdef CONFIG_DEBUG_PAGEALLOC
679 unsigned int _debug_guardpage_minorder
;
681 bool _debug_pagealloc_enabled_early __read_mostly
682 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
683 EXPORT_SYMBOL(_debug_pagealloc_enabled_early
);
684 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled
);
685 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
687 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled
);
689 static int __init
early_debug_pagealloc(char *buf
)
691 return kstrtobool(buf
, &_debug_pagealloc_enabled_early
);
693 early_param("debug_pagealloc", early_debug_pagealloc
);
695 static int __init
debug_guardpage_minorder_setup(char *buf
)
699 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
700 pr_err("Bad debug_guardpage_minorder value\n");
703 _debug_guardpage_minorder
= res
;
704 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
707 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
709 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
710 unsigned int order
, int migratetype
)
712 if (!debug_guardpage_enabled())
715 if (order
>= debug_guardpage_minorder())
718 __SetPageGuard(page
);
719 INIT_LIST_HEAD(&page
->lru
);
720 set_page_private(page
, order
);
721 /* Guard pages are not available for any usage */
722 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
727 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
728 unsigned int order
, int migratetype
)
730 if (!debug_guardpage_enabled())
733 __ClearPageGuard(page
);
735 set_page_private(page
, 0);
736 if (!is_migrate_isolate(migratetype
))
737 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
740 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
741 unsigned int order
, int migratetype
) { return false; }
742 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
743 unsigned int order
, int migratetype
) {}
747 * Enable static keys related to various memory debugging and hardening options.
748 * Some override others, and depend on early params that are evaluated in the
749 * order of appearance. So we need to first gather the full picture of what was
750 * enabled, and then make decisions.
752 void init_mem_debugging_and_hardening(void)
754 bool page_poisoning_requested
= false;
756 #ifdef CONFIG_PAGE_POISONING
758 * Page poisoning is debug page alloc for some arches. If
759 * either of those options are enabled, enable poisoning.
761 if (page_poisoning_enabled() ||
762 (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC
) &&
763 debug_pagealloc_enabled())) {
764 static_branch_enable(&_page_poisoning_enabled
);
765 page_poisoning_requested
= true;
769 if (_init_on_alloc_enabled_early
) {
770 if (page_poisoning_requested
)
771 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
772 "will take precedence over init_on_alloc\n");
774 static_branch_enable(&init_on_alloc
);
776 if (_init_on_free_enabled_early
) {
777 if (page_poisoning_requested
)
778 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
779 "will take precedence over init_on_free\n");
781 static_branch_enable(&init_on_free
);
784 #ifdef CONFIG_DEBUG_PAGEALLOC
785 if (!debug_pagealloc_enabled())
788 static_branch_enable(&_debug_pagealloc_enabled
);
790 if (!debug_guardpage_minorder())
793 static_branch_enable(&_debug_guardpage_enabled
);
797 static inline void set_buddy_order(struct page
*page
, unsigned int order
)
799 set_page_private(page
, order
);
800 __SetPageBuddy(page
);
804 * This function checks whether a page is free && is the buddy
805 * we can coalesce a page and its buddy if
806 * (a) the buddy is not in a hole (check before calling!) &&
807 * (b) the buddy is in the buddy system &&
808 * (c) a page and its buddy have the same order &&
809 * (d) a page and its buddy are in the same zone.
811 * For recording whether a page is in the buddy system, we set PageBuddy.
812 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
814 * For recording page's order, we use page_private(page).
816 static inline bool page_is_buddy(struct page
*page
, struct page
*buddy
,
819 if (!page_is_guard(buddy
) && !PageBuddy(buddy
))
822 if (buddy_order(buddy
) != order
)
826 * zone check is done late to avoid uselessly calculating
827 * zone/node ids for pages that could never merge.
829 if (page_zone_id(page
) != page_zone_id(buddy
))
832 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
837 #ifdef CONFIG_COMPACTION
838 static inline struct capture_control
*task_capc(struct zone
*zone
)
840 struct capture_control
*capc
= current
->capture_control
;
842 return unlikely(capc
) &&
843 !(current
->flags
& PF_KTHREAD
) &&
845 capc
->cc
->zone
== zone
? capc
: NULL
;
849 compaction_capture(struct capture_control
*capc
, struct page
*page
,
850 int order
, int migratetype
)
852 if (!capc
|| order
!= capc
->cc
->order
)
855 /* Do not accidentally pollute CMA or isolated regions*/
856 if (is_migrate_cma(migratetype
) ||
857 is_migrate_isolate(migratetype
))
861 * Do not let lower order allocations polluate a movable pageblock.
862 * This might let an unmovable request use a reclaimable pageblock
863 * and vice-versa but no more than normal fallback logic which can
864 * have trouble finding a high-order free page.
866 if (order
< pageblock_order
&& migratetype
== MIGRATE_MOVABLE
)
874 static inline struct capture_control
*task_capc(struct zone
*zone
)
880 compaction_capture(struct capture_control
*capc
, struct page
*page
,
881 int order
, int migratetype
)
885 #endif /* CONFIG_COMPACTION */
887 /* Used for pages not on another list */
888 static inline void add_to_free_list(struct page
*page
, struct zone
*zone
,
889 unsigned int order
, int migratetype
)
891 struct free_area
*area
= &zone
->free_area
[order
];
893 list_add(&page
->lru
, &area
->free_list
[migratetype
]);
897 /* Used for pages not on another list */
898 static inline void add_to_free_list_tail(struct page
*page
, struct zone
*zone
,
899 unsigned int order
, int migratetype
)
901 struct free_area
*area
= &zone
->free_area
[order
];
903 list_add_tail(&page
->lru
, &area
->free_list
[migratetype
]);
908 * Used for pages which are on another list. Move the pages to the tail
909 * of the list - so the moved pages won't immediately be considered for
910 * allocation again (e.g., optimization for memory onlining).
912 static inline void move_to_free_list(struct page
*page
, struct zone
*zone
,
913 unsigned int order
, int migratetype
)
915 struct free_area
*area
= &zone
->free_area
[order
];
917 list_move_tail(&page
->lru
, &area
->free_list
[migratetype
]);
920 static inline void del_page_from_free_list(struct page
*page
, struct zone
*zone
,
923 /* clear reported state and update reported page count */
924 if (page_reported(page
))
925 __ClearPageReported(page
);
927 list_del(&page
->lru
);
928 __ClearPageBuddy(page
);
929 set_page_private(page
, 0);
930 zone
->free_area
[order
].nr_free
--;
934 * If this is not the largest possible page, check if the buddy
935 * of the next-highest order is free. If it is, it's possible
936 * that pages are being freed that will coalesce soon. In case,
937 * that is happening, add the free page to the tail of the list
938 * so it's less likely to be used soon and more likely to be merged
939 * as a higher order page
942 buddy_merge_likely(unsigned long pfn
, unsigned long buddy_pfn
,
943 struct page
*page
, unsigned int order
)
945 struct page
*higher_page
, *higher_buddy
;
946 unsigned long combined_pfn
;
948 if (order
>= MAX_ORDER
- 2)
951 if (!pfn_valid_within(buddy_pfn
))
954 combined_pfn
= buddy_pfn
& pfn
;
955 higher_page
= page
+ (combined_pfn
- pfn
);
956 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
957 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
959 return pfn_valid_within(buddy_pfn
) &&
960 page_is_buddy(higher_page
, higher_buddy
, order
+ 1);
964 * Freeing function for a buddy system allocator.
966 * The concept of a buddy system is to maintain direct-mapped table
967 * (containing bit values) for memory blocks of various "orders".
968 * The bottom level table contains the map for the smallest allocatable
969 * units of memory (here, pages), and each level above it describes
970 * pairs of units from the levels below, hence, "buddies".
971 * At a high level, all that happens here is marking the table entry
972 * at the bottom level available, and propagating the changes upward
973 * as necessary, plus some accounting needed to play nicely with other
974 * parts of the VM system.
975 * At each level, we keep a list of pages, which are heads of continuous
976 * free pages of length of (1 << order) and marked with PageBuddy.
977 * Page's order is recorded in page_private(page) field.
978 * So when we are allocating or freeing one, we can derive the state of the
979 * other. That is, if we allocate a small block, and both were
980 * free, the remainder of the region must be split into blocks.
981 * If a block is freed, and its buddy is also free, then this
982 * triggers coalescing into a block of larger size.
987 static inline void __free_one_page(struct page
*page
,
989 struct zone
*zone
, unsigned int order
,
990 int migratetype
, fpi_t fpi_flags
)
992 struct capture_control
*capc
= task_capc(zone
);
993 unsigned long buddy_pfn
;
994 unsigned long combined_pfn
;
995 unsigned int max_order
;
999 max_order
= min_t(unsigned int, MAX_ORDER
- 1, pageblock_order
);
1001 VM_BUG_ON(!zone_is_initialized(zone
));
1002 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
1004 VM_BUG_ON(migratetype
== -1);
1005 if (likely(!is_migrate_isolate(migratetype
)))
1006 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
1008 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
1009 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
1012 while (order
< max_order
) {
1013 if (compaction_capture(capc
, page
, order
, migratetype
)) {
1014 __mod_zone_freepage_state(zone
, -(1 << order
),
1018 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1019 buddy
= page
+ (buddy_pfn
- pfn
);
1021 if (!pfn_valid_within(buddy_pfn
))
1023 if (!page_is_buddy(page
, buddy
, order
))
1026 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
1027 * merge with it and move up one order.
1029 if (page_is_guard(buddy
))
1030 clear_page_guard(zone
, buddy
, order
, migratetype
);
1032 del_page_from_free_list(buddy
, zone
, order
);
1033 combined_pfn
= buddy_pfn
& pfn
;
1034 page
= page
+ (combined_pfn
- pfn
);
1038 if (order
< MAX_ORDER
- 1) {
1039 /* If we are here, it means order is >= pageblock_order.
1040 * We want to prevent merge between freepages on isolate
1041 * pageblock and normal pageblock. Without this, pageblock
1042 * isolation could cause incorrect freepage or CMA accounting.
1044 * We don't want to hit this code for the more frequent
1045 * low-order merging.
1047 if (unlikely(has_isolate_pageblock(zone
))) {
1050 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1051 buddy
= page
+ (buddy_pfn
- pfn
);
1052 buddy_mt
= get_pageblock_migratetype(buddy
);
1054 if (migratetype
!= buddy_mt
1055 && (is_migrate_isolate(migratetype
) ||
1056 is_migrate_isolate(buddy_mt
)))
1059 max_order
= order
+ 1;
1060 goto continue_merging
;
1064 set_buddy_order(page
, order
);
1066 if (fpi_flags
& FPI_TO_TAIL
)
1068 else if (is_shuffle_order(order
))
1069 to_tail
= shuffle_pick_tail();
1071 to_tail
= buddy_merge_likely(pfn
, buddy_pfn
, page
, order
);
1074 add_to_free_list_tail(page
, zone
, order
, migratetype
);
1076 add_to_free_list(page
, zone
, order
, migratetype
);
1078 /* Notify page reporting subsystem of freed page */
1079 if (!(fpi_flags
& FPI_SKIP_REPORT_NOTIFY
))
1080 page_reporting_notify_free(order
);
1084 * A bad page could be due to a number of fields. Instead of multiple branches,
1085 * try and check multiple fields with one check. The caller must do a detailed
1086 * check if necessary.
1088 static inline bool page_expected_state(struct page
*page
,
1089 unsigned long check_flags
)
1091 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1094 if (unlikely((unsigned long)page
->mapping
|
1095 page_ref_count(page
) |
1097 (unsigned long)page_memcg(page
) |
1099 (page
->flags
& check_flags
)))
1105 static const char *page_bad_reason(struct page
*page
, unsigned long flags
)
1107 const char *bad_reason
= NULL
;
1109 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1110 bad_reason
= "nonzero mapcount";
1111 if (unlikely(page
->mapping
!= NULL
))
1112 bad_reason
= "non-NULL mapping";
1113 if (unlikely(page_ref_count(page
) != 0))
1114 bad_reason
= "nonzero _refcount";
1115 if (unlikely(page
->flags
& flags
)) {
1116 if (flags
== PAGE_FLAGS_CHECK_AT_PREP
)
1117 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1119 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1122 if (unlikely(page_memcg(page
)))
1123 bad_reason
= "page still charged to cgroup";
1128 static void check_free_page_bad(struct page
*page
)
1131 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_FREE
));
1134 static inline int check_free_page(struct page
*page
)
1136 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
1139 /* Something has gone sideways, find it */
1140 check_free_page_bad(page
);
1144 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
1149 * We rely page->lru.next never has bit 0 set, unless the page
1150 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1152 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
1154 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
1158 switch (page
- head_page
) {
1160 /* the first tail page: ->mapping may be compound_mapcount() */
1161 if (unlikely(compound_mapcount(page
))) {
1162 bad_page(page
, "nonzero compound_mapcount");
1168 * the second tail page: ->mapping is
1169 * deferred_list.next -- ignore value.
1173 if (page
->mapping
!= TAIL_MAPPING
) {
1174 bad_page(page
, "corrupted mapping in tail page");
1179 if (unlikely(!PageTail(page
))) {
1180 bad_page(page
, "PageTail not set");
1183 if (unlikely(compound_head(page
) != head_page
)) {
1184 bad_page(page
, "compound_head not consistent");
1189 page
->mapping
= NULL
;
1190 clear_compound_head(page
);
1194 static void kernel_init_free_pages(struct page
*page
, int numpages
)
1198 /* s390's use of memset() could override KASAN redzones. */
1199 kasan_disable_current();
1200 for (i
= 0; i
< numpages
; i
++) {
1201 u8 tag
= page_kasan_tag(page
+ i
);
1202 page_kasan_tag_reset(page
+ i
);
1203 clear_highpage(page
+ i
);
1204 page_kasan_tag_set(page
+ i
, tag
);
1206 kasan_enable_current();
1209 static __always_inline
bool free_pages_prepare(struct page
*page
,
1210 unsigned int order
, bool check_free
)
1214 VM_BUG_ON_PAGE(PageTail(page
), page
);
1216 trace_mm_page_free(page
, order
);
1218 if (unlikely(PageHWPoison(page
)) && !order
) {
1220 * Do not let hwpoison pages hit pcplists/buddy
1221 * Untie memcg state and reset page's owner
1223 if (memcg_kmem_enabled() && PageMemcgKmem(page
))
1224 __memcg_kmem_uncharge_page(page
, order
);
1225 reset_page_owner(page
, order
);
1230 * Check tail pages before head page information is cleared to
1231 * avoid checking PageCompound for order-0 pages.
1233 if (unlikely(order
)) {
1234 bool compound
= PageCompound(page
);
1237 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1240 ClearPageDoubleMap(page
);
1241 for (i
= 1; i
< (1 << order
); i
++) {
1243 bad
+= free_tail_pages_check(page
, page
+ i
);
1244 if (unlikely(check_free_page(page
+ i
))) {
1248 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1251 if (PageMappingFlags(page
))
1252 page
->mapping
= NULL
;
1253 if (memcg_kmem_enabled() && PageMemcgKmem(page
))
1254 __memcg_kmem_uncharge_page(page
, order
);
1256 bad
+= check_free_page(page
);
1260 page_cpupid_reset_last(page
);
1261 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1262 reset_page_owner(page
, order
);
1264 if (!PageHighMem(page
)) {
1265 debug_check_no_locks_freed(page_address(page
),
1266 PAGE_SIZE
<< order
);
1267 debug_check_no_obj_freed(page_address(page
),
1268 PAGE_SIZE
<< order
);
1270 if (want_init_on_free())
1271 kernel_init_free_pages(page
, 1 << order
);
1273 kernel_poison_pages(page
, 1 << order
);
1276 * With hardware tag-based KASAN, memory tags must be set before the
1277 * page becomes unavailable via debug_pagealloc or arch_free_page.
1279 kasan_free_nondeferred_pages(page
, order
);
1282 * arch_free_page() can make the page's contents inaccessible. s390
1283 * does this. So nothing which can access the page's contents should
1284 * happen after this.
1286 arch_free_page(page
, order
);
1288 debug_pagealloc_unmap_pages(page
, 1 << order
);
1293 #ifdef CONFIG_DEBUG_VM
1295 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1296 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1297 * moved from pcp lists to free lists.
1299 static bool free_pcp_prepare(struct page
*page
)
1301 return free_pages_prepare(page
, 0, true);
1304 static bool bulkfree_pcp_prepare(struct page
*page
)
1306 if (debug_pagealloc_enabled_static())
1307 return check_free_page(page
);
1313 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1314 * moving from pcp lists to free list in order to reduce overhead. With
1315 * debug_pagealloc enabled, they are checked also immediately when being freed
1318 static bool free_pcp_prepare(struct page
*page
)
1320 if (debug_pagealloc_enabled_static())
1321 return free_pages_prepare(page
, 0, true);
1323 return free_pages_prepare(page
, 0, false);
1326 static bool bulkfree_pcp_prepare(struct page
*page
)
1328 return check_free_page(page
);
1330 #endif /* CONFIG_DEBUG_VM */
1332 static inline void prefetch_buddy(struct page
*page
)
1334 unsigned long pfn
= page_to_pfn(page
);
1335 unsigned long buddy_pfn
= __find_buddy_pfn(pfn
, 0);
1336 struct page
*buddy
= page
+ (buddy_pfn
- pfn
);
1342 * Frees a number of pages from the PCP lists
1343 * Assumes all pages on list are in same zone, and of same order.
1344 * count is the number of pages to free.
1346 * If the zone was previously in an "all pages pinned" state then look to
1347 * see if this freeing clears that state.
1349 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1350 * pinned" detection logic.
1352 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1353 struct per_cpu_pages
*pcp
)
1355 int migratetype
= 0;
1357 int prefetch_nr
= READ_ONCE(pcp
->batch
);
1358 bool isolated_pageblocks
;
1359 struct page
*page
, *tmp
;
1363 * Ensure proper count is passed which otherwise would stuck in the
1364 * below while (list_empty(list)) loop.
1366 count
= min(pcp
->count
, count
);
1368 struct list_head
*list
;
1371 * Remove pages from lists in a round-robin fashion. A
1372 * batch_free count is maintained that is incremented when an
1373 * empty list is encountered. This is so more pages are freed
1374 * off fuller lists instead of spinning excessively around empty
1379 if (++migratetype
== MIGRATE_PCPTYPES
)
1381 list
= &pcp
->lists
[migratetype
];
1382 } while (list_empty(list
));
1384 /* This is the only non-empty list. Free them all. */
1385 if (batch_free
== MIGRATE_PCPTYPES
)
1389 page
= list_last_entry(list
, struct page
, lru
);
1390 /* must delete to avoid corrupting pcp list */
1391 list_del(&page
->lru
);
1394 if (bulkfree_pcp_prepare(page
))
1397 list_add_tail(&page
->lru
, &head
);
1400 * We are going to put the page back to the global
1401 * pool, prefetch its buddy to speed up later access
1402 * under zone->lock. It is believed the overhead of
1403 * an additional test and calculating buddy_pfn here
1404 * can be offset by reduced memory latency later. To
1405 * avoid excessive prefetching due to large count, only
1406 * prefetch buddy for the first pcp->batch nr of pages.
1409 prefetch_buddy(page
);
1412 } while (--count
&& --batch_free
&& !list_empty(list
));
1415 spin_lock(&zone
->lock
);
1416 isolated_pageblocks
= has_isolate_pageblock(zone
);
1419 * Use safe version since after __free_one_page(),
1420 * page->lru.next will not point to original list.
1422 list_for_each_entry_safe(page
, tmp
, &head
, lru
) {
1423 int mt
= get_pcppage_migratetype(page
);
1424 /* MIGRATE_ISOLATE page should not go to pcplists */
1425 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1426 /* Pageblock could have been isolated meanwhile */
1427 if (unlikely(isolated_pageblocks
))
1428 mt
= get_pageblock_migratetype(page
);
1430 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
, FPI_NONE
);
1431 trace_mm_page_pcpu_drain(page
, 0, mt
);
1433 spin_unlock(&zone
->lock
);
1436 static void free_one_page(struct zone
*zone
,
1437 struct page
*page
, unsigned long pfn
,
1439 int migratetype
, fpi_t fpi_flags
)
1441 spin_lock(&zone
->lock
);
1442 if (unlikely(has_isolate_pageblock(zone
) ||
1443 is_migrate_isolate(migratetype
))) {
1444 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1446 __free_one_page(page
, pfn
, zone
, order
, migratetype
, fpi_flags
);
1447 spin_unlock(&zone
->lock
);
1450 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1451 unsigned long zone
, int nid
)
1453 mm_zero_struct_page(page
);
1454 set_page_links(page
, zone
, nid
, pfn
);
1455 init_page_count(page
);
1456 page_mapcount_reset(page
);
1457 page_cpupid_reset_last(page
);
1458 page_kasan_tag_reset(page
);
1460 INIT_LIST_HEAD(&page
->lru
);
1461 #ifdef WANT_PAGE_VIRTUAL
1462 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1463 if (!is_highmem_idx(zone
))
1464 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1468 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1469 static void __meminit
init_reserved_page(unsigned long pfn
)
1474 if (!early_page_uninitialised(pfn
))
1477 nid
= early_pfn_to_nid(pfn
);
1478 pgdat
= NODE_DATA(nid
);
1480 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1481 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1483 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1486 __init_single_page(pfn_to_page(pfn
), pfn
, zid
, nid
);
1489 static inline void init_reserved_page(unsigned long pfn
)
1492 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1495 * Initialised pages do not have PageReserved set. This function is
1496 * called for each range allocated by the bootmem allocator and
1497 * marks the pages PageReserved. The remaining valid pages are later
1498 * sent to the buddy page allocator.
1500 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1502 unsigned long start_pfn
= PFN_DOWN(start
);
1503 unsigned long end_pfn
= PFN_UP(end
);
1505 for (; start_pfn
< end_pfn
; start_pfn
++) {
1506 if (pfn_valid(start_pfn
)) {
1507 struct page
*page
= pfn_to_page(start_pfn
);
1509 init_reserved_page(start_pfn
);
1511 /* Avoid false-positive PageTail() */
1512 INIT_LIST_HEAD(&page
->lru
);
1515 * no need for atomic set_bit because the struct
1516 * page is not visible yet so nobody should
1519 __SetPageReserved(page
);
1524 static void __free_pages_ok(struct page
*page
, unsigned int order
,
1527 unsigned long flags
;
1529 unsigned long pfn
= page_to_pfn(page
);
1531 if (!free_pages_prepare(page
, order
, true))
1534 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1535 local_irq_save(flags
);
1536 __count_vm_events(PGFREE
, 1 << order
);
1537 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
,
1539 local_irq_restore(flags
);
1542 void __free_pages_core(struct page
*page
, unsigned int order
)
1544 unsigned int nr_pages
= 1 << order
;
1545 struct page
*p
= page
;
1549 * When initializing the memmap, __init_single_page() sets the refcount
1550 * of all pages to 1 ("allocated"/"not free"). We have to set the
1551 * refcount of all involved pages to 0.
1554 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1556 __ClearPageReserved(p
);
1557 set_page_count(p
, 0);
1559 __ClearPageReserved(p
);
1560 set_page_count(p
, 0);
1562 atomic_long_add(nr_pages
, &page_zone(page
)->managed_pages
);
1565 * Bypass PCP and place fresh pages right to the tail, primarily
1566 * relevant for memory onlining.
1568 __free_pages_ok(page
, order
, FPI_TO_TAIL
);
1571 #ifdef CONFIG_NEED_MULTIPLE_NODES
1574 * During memory init memblocks map pfns to nids. The search is expensive and
1575 * this caches recent lookups. The implementation of __early_pfn_to_nid
1576 * treats start/end as pfns.
1578 struct mminit_pfnnid_cache
{
1579 unsigned long last_start
;
1580 unsigned long last_end
;
1584 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1587 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1589 static int __meminit
__early_pfn_to_nid(unsigned long pfn
,
1590 struct mminit_pfnnid_cache
*state
)
1592 unsigned long start_pfn
, end_pfn
;
1595 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
1596 return state
->last_nid
;
1598 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
1599 if (nid
!= NUMA_NO_NODE
) {
1600 state
->last_start
= start_pfn
;
1601 state
->last_end
= end_pfn
;
1602 state
->last_nid
= nid
;
1608 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1610 static DEFINE_SPINLOCK(early_pfn_lock
);
1613 spin_lock(&early_pfn_lock
);
1614 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1616 nid
= first_online_node
;
1617 spin_unlock(&early_pfn_lock
);
1621 #endif /* CONFIG_NEED_MULTIPLE_NODES */
1623 void __init
memblock_free_pages(struct page
*page
, unsigned long pfn
,
1626 if (early_page_uninitialised(pfn
))
1628 __free_pages_core(page
, order
);
1632 * Check that the whole (or subset of) a pageblock given by the interval of
1633 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1634 * with the migration of free compaction scanner. The scanners then need to
1635 * use only pfn_valid_within() check for arches that allow holes within
1638 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1640 * It's possible on some configurations to have a setup like node0 node1 node0
1641 * i.e. it's possible that all pages within a zones range of pages do not
1642 * belong to a single zone. We assume that a border between node0 and node1
1643 * can occur within a single pageblock, but not a node0 node1 node0
1644 * interleaving within a single pageblock. It is therefore sufficient to check
1645 * the first and last page of a pageblock and avoid checking each individual
1646 * page in a pageblock.
1648 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1649 unsigned long end_pfn
, struct zone
*zone
)
1651 struct page
*start_page
;
1652 struct page
*end_page
;
1654 /* end_pfn is one past the range we are checking */
1657 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1660 start_page
= pfn_to_online_page(start_pfn
);
1664 if (page_zone(start_page
) != zone
)
1667 end_page
= pfn_to_page(end_pfn
);
1669 /* This gives a shorter code than deriving page_zone(end_page) */
1670 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1676 void set_zone_contiguous(struct zone
*zone
)
1678 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1679 unsigned long block_end_pfn
;
1681 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1682 for (; block_start_pfn
< zone_end_pfn(zone
);
1683 block_start_pfn
= block_end_pfn
,
1684 block_end_pfn
+= pageblock_nr_pages
) {
1686 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1688 if (!__pageblock_pfn_to_page(block_start_pfn
,
1689 block_end_pfn
, zone
))
1694 /* We confirm that there is no hole */
1695 zone
->contiguous
= true;
1698 void clear_zone_contiguous(struct zone
*zone
)
1700 zone
->contiguous
= false;
1703 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1704 static void __init
deferred_free_range(unsigned long pfn
,
1705 unsigned long nr_pages
)
1713 page
= pfn_to_page(pfn
);
1715 /* Free a large naturally-aligned chunk if possible */
1716 if (nr_pages
== pageblock_nr_pages
&&
1717 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1718 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1719 __free_pages_core(page
, pageblock_order
);
1723 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1724 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1725 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1726 __free_pages_core(page
, 0);
1730 /* Completion tracking for deferred_init_memmap() threads */
1731 static atomic_t pgdat_init_n_undone __initdata
;
1732 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1734 static inline void __init
pgdat_init_report_one_done(void)
1736 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1737 complete(&pgdat_init_all_done_comp
);
1741 * Returns true if page needs to be initialized or freed to buddy allocator.
1743 * First we check if pfn is valid on architectures where it is possible to have
1744 * holes within pageblock_nr_pages. On systems where it is not possible, this
1745 * function is optimized out.
1747 * Then, we check if a current large page is valid by only checking the validity
1750 static inline bool __init
deferred_pfn_valid(unsigned long pfn
)
1752 if (!pfn_valid_within(pfn
))
1754 if (!(pfn
& (pageblock_nr_pages
- 1)) && !pfn_valid(pfn
))
1760 * Free pages to buddy allocator. Try to free aligned pages in
1761 * pageblock_nr_pages sizes.
1763 static void __init
deferred_free_pages(unsigned long pfn
,
1764 unsigned long end_pfn
)
1766 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1767 unsigned long nr_free
= 0;
1769 for (; pfn
< end_pfn
; pfn
++) {
1770 if (!deferred_pfn_valid(pfn
)) {
1771 deferred_free_range(pfn
- nr_free
, nr_free
);
1773 } else if (!(pfn
& nr_pgmask
)) {
1774 deferred_free_range(pfn
- nr_free
, nr_free
);
1780 /* Free the last block of pages to allocator */
1781 deferred_free_range(pfn
- nr_free
, nr_free
);
1785 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1786 * by performing it only once every pageblock_nr_pages.
1787 * Return number of pages initialized.
1789 static unsigned long __init
deferred_init_pages(struct zone
*zone
,
1791 unsigned long end_pfn
)
1793 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1794 int nid
= zone_to_nid(zone
);
1795 unsigned long nr_pages
= 0;
1796 int zid
= zone_idx(zone
);
1797 struct page
*page
= NULL
;
1799 for (; pfn
< end_pfn
; pfn
++) {
1800 if (!deferred_pfn_valid(pfn
)) {
1803 } else if (!page
|| !(pfn
& nr_pgmask
)) {
1804 page
= pfn_to_page(pfn
);
1808 __init_single_page(page
, pfn
, zid
, nid
);
1815 * This function is meant to pre-load the iterator for the zone init.
1816 * Specifically it walks through the ranges until we are caught up to the
1817 * first_init_pfn value and exits there. If we never encounter the value we
1818 * return false indicating there are no valid ranges left.
1821 deferred_init_mem_pfn_range_in_zone(u64
*i
, struct zone
*zone
,
1822 unsigned long *spfn
, unsigned long *epfn
,
1823 unsigned long first_init_pfn
)
1828 * Start out by walking through the ranges in this zone that have
1829 * already been initialized. We don't need to do anything with them
1830 * so we just need to flush them out of the system.
1832 for_each_free_mem_pfn_range_in_zone(j
, zone
, spfn
, epfn
) {
1833 if (*epfn
<= first_init_pfn
)
1835 if (*spfn
< first_init_pfn
)
1836 *spfn
= first_init_pfn
;
1845 * Initialize and free pages. We do it in two loops: first we initialize
1846 * struct page, then free to buddy allocator, because while we are
1847 * freeing pages we can access pages that are ahead (computing buddy
1848 * page in __free_one_page()).
1850 * In order to try and keep some memory in the cache we have the loop
1851 * broken along max page order boundaries. This way we will not cause
1852 * any issues with the buddy page computation.
1854 static unsigned long __init
1855 deferred_init_maxorder(u64
*i
, struct zone
*zone
, unsigned long *start_pfn
,
1856 unsigned long *end_pfn
)
1858 unsigned long mo_pfn
= ALIGN(*start_pfn
+ 1, MAX_ORDER_NR_PAGES
);
1859 unsigned long spfn
= *start_pfn
, epfn
= *end_pfn
;
1860 unsigned long nr_pages
= 0;
1863 /* First we loop through and initialize the page values */
1864 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, start_pfn
, end_pfn
) {
1867 if (mo_pfn
<= *start_pfn
)
1870 t
= min(mo_pfn
, *end_pfn
);
1871 nr_pages
+= deferred_init_pages(zone
, *start_pfn
, t
);
1873 if (mo_pfn
< *end_pfn
) {
1874 *start_pfn
= mo_pfn
;
1879 /* Reset values and now loop through freeing pages as needed */
1882 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, &spfn
, &epfn
) {
1888 t
= min(mo_pfn
, epfn
);
1889 deferred_free_pages(spfn
, t
);
1899 deferred_init_memmap_chunk(unsigned long start_pfn
, unsigned long end_pfn
,
1902 unsigned long spfn
, epfn
;
1903 struct zone
*zone
= arg
;
1906 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
, start_pfn
);
1909 * Initialize and free pages in MAX_ORDER sized increments so that we
1910 * can avoid introducing any issues with the buddy allocator.
1912 while (spfn
< end_pfn
) {
1913 deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1918 /* An arch may override for more concurrency. */
1920 deferred_page_init_max_threads(const struct cpumask
*node_cpumask
)
1925 /* Initialise remaining memory on a node */
1926 static int __init
deferred_init_memmap(void *data
)
1928 pg_data_t
*pgdat
= data
;
1929 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1930 unsigned long spfn
= 0, epfn
= 0;
1931 unsigned long first_init_pfn
, flags
;
1932 unsigned long start
= jiffies
;
1934 int zid
, max_threads
;
1937 /* Bind memory initialisation thread to a local node if possible */
1938 if (!cpumask_empty(cpumask
))
1939 set_cpus_allowed_ptr(current
, cpumask
);
1941 pgdat_resize_lock(pgdat
, &flags
);
1942 first_init_pfn
= pgdat
->first_deferred_pfn
;
1943 if (first_init_pfn
== ULONG_MAX
) {
1944 pgdat_resize_unlock(pgdat
, &flags
);
1945 pgdat_init_report_one_done();
1949 /* Sanity check boundaries */
1950 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1951 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1952 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1955 * Once we unlock here, the zone cannot be grown anymore, thus if an
1956 * interrupt thread must allocate this early in boot, zone must be
1957 * pre-grown prior to start of deferred page initialization.
1959 pgdat_resize_unlock(pgdat
, &flags
);
1961 /* Only the highest zone is deferred so find it */
1962 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1963 zone
= pgdat
->node_zones
+ zid
;
1964 if (first_init_pfn
< zone_end_pfn(zone
))
1968 /* If the zone is empty somebody else may have cleared out the zone */
1969 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1973 max_threads
= deferred_page_init_max_threads(cpumask
);
1975 while (spfn
< epfn
) {
1976 unsigned long epfn_align
= ALIGN(epfn
, PAGES_PER_SECTION
);
1977 struct padata_mt_job job
= {
1978 .thread_fn
= deferred_init_memmap_chunk
,
1981 .size
= epfn_align
- spfn
,
1982 .align
= PAGES_PER_SECTION
,
1983 .min_chunk
= PAGES_PER_SECTION
,
1984 .max_threads
= max_threads
,
1987 padata_do_multithreaded(&job
);
1988 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1992 /* Sanity check that the next zone really is unpopulated */
1993 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1995 pr_info("node %d deferred pages initialised in %ums\n",
1996 pgdat
->node_id
, jiffies_to_msecs(jiffies
- start
));
1998 pgdat_init_report_one_done();
2003 * If this zone has deferred pages, try to grow it by initializing enough
2004 * deferred pages to satisfy the allocation specified by order, rounded up to
2005 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
2006 * of SECTION_SIZE bytes by initializing struct pages in increments of
2007 * PAGES_PER_SECTION * sizeof(struct page) bytes.
2009 * Return true when zone was grown, otherwise return false. We return true even
2010 * when we grow less than requested, to let the caller decide if there are
2011 * enough pages to satisfy the allocation.
2013 * Note: We use noinline because this function is needed only during boot, and
2014 * it is called from a __ref function _deferred_grow_zone. This way we are
2015 * making sure that it is not inlined into permanent text section.
2017 static noinline
bool __init
2018 deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2020 unsigned long nr_pages_needed
= ALIGN(1 << order
, PAGES_PER_SECTION
);
2021 pg_data_t
*pgdat
= zone
->zone_pgdat
;
2022 unsigned long first_deferred_pfn
= pgdat
->first_deferred_pfn
;
2023 unsigned long spfn
, epfn
, flags
;
2024 unsigned long nr_pages
= 0;
2027 /* Only the last zone may have deferred pages */
2028 if (zone_end_pfn(zone
) != pgdat_end_pfn(pgdat
))
2031 pgdat_resize_lock(pgdat
, &flags
);
2034 * If someone grew this zone while we were waiting for spinlock, return
2035 * true, as there might be enough pages already.
2037 if (first_deferred_pfn
!= pgdat
->first_deferred_pfn
) {
2038 pgdat_resize_unlock(pgdat
, &flags
);
2042 /* If the zone is empty somebody else may have cleared out the zone */
2043 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
2044 first_deferred_pfn
)) {
2045 pgdat
->first_deferred_pfn
= ULONG_MAX
;
2046 pgdat_resize_unlock(pgdat
, &flags
);
2047 /* Retry only once. */
2048 return first_deferred_pfn
!= ULONG_MAX
;
2052 * Initialize and free pages in MAX_ORDER sized increments so
2053 * that we can avoid introducing any issues with the buddy
2056 while (spfn
< epfn
) {
2057 /* update our first deferred PFN for this section */
2058 first_deferred_pfn
= spfn
;
2060 nr_pages
+= deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
2061 touch_nmi_watchdog();
2063 /* We should only stop along section boundaries */
2064 if ((first_deferred_pfn
^ spfn
) < PAGES_PER_SECTION
)
2067 /* If our quota has been met we can stop here */
2068 if (nr_pages
>= nr_pages_needed
)
2072 pgdat
->first_deferred_pfn
= spfn
;
2073 pgdat_resize_unlock(pgdat
, &flags
);
2075 return nr_pages
> 0;
2079 * deferred_grow_zone() is __init, but it is called from
2080 * get_page_from_freelist() during early boot until deferred_pages permanently
2081 * disables this call. This is why we have refdata wrapper to avoid warning,
2082 * and to ensure that the function body gets unloaded.
2085 _deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2087 return deferred_grow_zone(zone
, order
);
2090 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2092 void __init
page_alloc_init_late(void)
2097 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2099 /* There will be num_node_state(N_MEMORY) threads */
2100 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
2101 for_each_node_state(nid
, N_MEMORY
) {
2102 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
2105 /* Block until all are initialised */
2106 wait_for_completion(&pgdat_init_all_done_comp
);
2109 * The number of managed pages has changed due to the initialisation
2110 * so the pcpu batch and high limits needs to be updated or the limits
2111 * will be artificially small.
2113 for_each_populated_zone(zone
)
2114 zone_pcp_update(zone
);
2117 * We initialized the rest of the deferred pages. Permanently disable
2118 * on-demand struct page initialization.
2120 static_branch_disable(&deferred_pages
);
2122 /* Reinit limits that are based on free pages after the kernel is up */
2123 files_maxfiles_init();
2128 /* Discard memblock private memory */
2131 for_each_node_state(nid
, N_MEMORY
)
2132 shuffle_free_memory(NODE_DATA(nid
));
2134 for_each_populated_zone(zone
)
2135 set_zone_contiguous(zone
);
2139 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2140 void __init
init_cma_reserved_pageblock(struct page
*page
)
2142 unsigned i
= pageblock_nr_pages
;
2143 struct page
*p
= page
;
2146 __ClearPageReserved(p
);
2147 set_page_count(p
, 0);
2150 set_pageblock_migratetype(page
, MIGRATE_CMA
);
2152 if (pageblock_order
>= MAX_ORDER
) {
2153 i
= pageblock_nr_pages
;
2156 set_page_refcounted(p
);
2157 __free_pages(p
, MAX_ORDER
- 1);
2158 p
+= MAX_ORDER_NR_PAGES
;
2159 } while (i
-= MAX_ORDER_NR_PAGES
);
2161 set_page_refcounted(page
);
2162 __free_pages(page
, pageblock_order
);
2165 adjust_managed_page_count(page
, pageblock_nr_pages
);
2170 * The order of subdivision here is critical for the IO subsystem.
2171 * Please do not alter this order without good reasons and regression
2172 * testing. Specifically, as large blocks of memory are subdivided,
2173 * the order in which smaller blocks are delivered depends on the order
2174 * they're subdivided in this function. This is the primary factor
2175 * influencing the order in which pages are delivered to the IO
2176 * subsystem according to empirical testing, and this is also justified
2177 * by considering the behavior of a buddy system containing a single
2178 * large block of memory acted on by a series of small allocations.
2179 * This behavior is a critical factor in sglist merging's success.
2183 static inline void expand(struct zone
*zone
, struct page
*page
,
2184 int low
, int high
, int migratetype
)
2186 unsigned long size
= 1 << high
;
2188 while (high
> low
) {
2191 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
2194 * Mark as guard pages (or page), that will allow to
2195 * merge back to allocator when buddy will be freed.
2196 * Corresponding page table entries will not be touched,
2197 * pages will stay not present in virtual address space
2199 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
2202 add_to_free_list(&page
[size
], zone
, high
, migratetype
);
2203 set_buddy_order(&page
[size
], high
);
2207 static void check_new_page_bad(struct page
*page
)
2209 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
2210 /* Don't complain about hwpoisoned pages */
2211 page_mapcount_reset(page
); /* remove PageBuddy */
2216 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_PREP
));
2220 * This page is about to be returned from the page allocator
2222 static inline int check_new_page(struct page
*page
)
2224 if (likely(page_expected_state(page
,
2225 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
2228 check_new_page_bad(page
);
2232 #ifdef CONFIG_DEBUG_VM
2234 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2235 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2236 * also checked when pcp lists are refilled from the free lists.
2238 static inline bool check_pcp_refill(struct page
*page
)
2240 if (debug_pagealloc_enabled_static())
2241 return check_new_page(page
);
2246 static inline bool check_new_pcp(struct page
*page
)
2248 return check_new_page(page
);
2252 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2253 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2254 * enabled, they are also checked when being allocated from the pcp lists.
2256 static inline bool check_pcp_refill(struct page
*page
)
2258 return check_new_page(page
);
2260 static inline bool check_new_pcp(struct page
*page
)
2262 if (debug_pagealloc_enabled_static())
2263 return check_new_page(page
);
2267 #endif /* CONFIG_DEBUG_VM */
2269 static bool check_new_pages(struct page
*page
, unsigned int order
)
2272 for (i
= 0; i
< (1 << order
); i
++) {
2273 struct page
*p
= page
+ i
;
2275 if (unlikely(check_new_page(p
)))
2282 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
2285 set_page_private(page
, 0);
2286 set_page_refcounted(page
);
2288 arch_alloc_page(page
, order
);
2289 debug_pagealloc_map_pages(page
, 1 << order
);
2290 kasan_alloc_pages(page
, order
);
2291 kernel_unpoison_pages(page
, 1 << order
);
2292 set_page_owner(page
, order
, gfp_flags
);
2294 if (!want_init_on_free() && want_init_on_alloc(gfp_flags
))
2295 kernel_init_free_pages(page
, 1 << order
);
2298 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
2299 unsigned int alloc_flags
)
2301 post_alloc_hook(page
, order
, gfp_flags
);
2303 if (order
&& (gfp_flags
& __GFP_COMP
))
2304 prep_compound_page(page
, order
);
2307 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2308 * allocate the page. The expectation is that the caller is taking
2309 * steps that will free more memory. The caller should avoid the page
2310 * being used for !PFMEMALLOC purposes.
2312 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2313 set_page_pfmemalloc(page
);
2315 clear_page_pfmemalloc(page
);
2319 * Go through the free lists for the given migratetype and remove
2320 * the smallest available page from the freelists
2322 static __always_inline
2323 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
2326 unsigned int current_order
;
2327 struct free_area
*area
;
2330 /* Find a page of the appropriate size in the preferred list */
2331 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
2332 area
= &(zone
->free_area
[current_order
]);
2333 page
= get_page_from_free_area(area
, migratetype
);
2336 del_page_from_free_list(page
, zone
, current_order
);
2337 expand(zone
, page
, order
, current_order
, migratetype
);
2338 set_pcppage_migratetype(page
, migratetype
);
2347 * This array describes the order lists are fallen back to when
2348 * the free lists for the desirable migrate type are depleted
2350 static int fallbacks
[MIGRATE_TYPES
][3] = {
2351 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2352 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
2353 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2355 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
2357 #ifdef CONFIG_MEMORY_ISOLATION
2358 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
2363 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2366 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
2369 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2370 unsigned int order
) { return NULL
; }
2374 * Move the free pages in a range to the freelist tail of the requested type.
2375 * Note that start_page and end_pages are not aligned on a pageblock
2376 * boundary. If alignment is required, use move_freepages_block()
2378 static int move_freepages(struct zone
*zone
,
2379 struct page
*start_page
, struct page
*end_page
,
2380 int migratetype
, int *num_movable
)
2384 int pages_moved
= 0;
2386 for (page
= start_page
; page
<= end_page
;) {
2387 if (!pfn_valid_within(page_to_pfn(page
))) {
2392 if (!PageBuddy(page
)) {
2394 * We assume that pages that could be isolated for
2395 * migration are movable. But we don't actually try
2396 * isolating, as that would be expensive.
2399 (PageLRU(page
) || __PageMovable(page
)))
2406 /* Make sure we are not inadvertently changing nodes */
2407 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
2408 VM_BUG_ON_PAGE(page_zone(page
) != zone
, page
);
2410 order
= buddy_order(page
);
2411 move_to_free_list(page
, zone
, order
, migratetype
);
2413 pages_moved
+= 1 << order
;
2419 int move_freepages_block(struct zone
*zone
, struct page
*page
,
2420 int migratetype
, int *num_movable
)
2422 unsigned long start_pfn
, end_pfn
;
2423 struct page
*start_page
, *end_page
;
2428 start_pfn
= page_to_pfn(page
);
2429 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
2430 start_page
= pfn_to_page(start_pfn
);
2431 end_page
= start_page
+ pageblock_nr_pages
- 1;
2432 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
2434 /* Do not cross zone boundaries */
2435 if (!zone_spans_pfn(zone
, start_pfn
))
2437 if (!zone_spans_pfn(zone
, end_pfn
))
2440 return move_freepages(zone
, start_page
, end_page
, migratetype
,
2444 static void change_pageblock_range(struct page
*pageblock_page
,
2445 int start_order
, int migratetype
)
2447 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
2449 while (nr_pageblocks
--) {
2450 set_pageblock_migratetype(pageblock_page
, migratetype
);
2451 pageblock_page
+= pageblock_nr_pages
;
2456 * When we are falling back to another migratetype during allocation, try to
2457 * steal extra free pages from the same pageblocks to satisfy further
2458 * allocations, instead of polluting multiple pageblocks.
2460 * If we are stealing a relatively large buddy page, it is likely there will
2461 * be more free pages in the pageblock, so try to steal them all. For
2462 * reclaimable and unmovable allocations, we steal regardless of page size,
2463 * as fragmentation caused by those allocations polluting movable pageblocks
2464 * is worse than movable allocations stealing from unmovable and reclaimable
2467 static bool can_steal_fallback(unsigned int order
, int start_mt
)
2470 * Leaving this order check is intended, although there is
2471 * relaxed order check in next check. The reason is that
2472 * we can actually steal whole pageblock if this condition met,
2473 * but, below check doesn't guarantee it and that is just heuristic
2474 * so could be changed anytime.
2476 if (order
>= pageblock_order
)
2479 if (order
>= pageblock_order
/ 2 ||
2480 start_mt
== MIGRATE_RECLAIMABLE
||
2481 start_mt
== MIGRATE_UNMOVABLE
||
2482 page_group_by_mobility_disabled
)
2488 static inline bool boost_watermark(struct zone
*zone
)
2490 unsigned long max_boost
;
2492 if (!watermark_boost_factor
)
2495 * Don't bother in zones that are unlikely to produce results.
2496 * On small machines, including kdump capture kernels running
2497 * in a small area, boosting the watermark can cause an out of
2498 * memory situation immediately.
2500 if ((pageblock_nr_pages
* 4) > zone_managed_pages(zone
))
2503 max_boost
= mult_frac(zone
->_watermark
[WMARK_HIGH
],
2504 watermark_boost_factor
, 10000);
2507 * high watermark may be uninitialised if fragmentation occurs
2508 * very early in boot so do not boost. We do not fall
2509 * through and boost by pageblock_nr_pages as failing
2510 * allocations that early means that reclaim is not going
2511 * to help and it may even be impossible to reclaim the
2512 * boosted watermark resulting in a hang.
2517 max_boost
= max(pageblock_nr_pages
, max_boost
);
2519 zone
->watermark_boost
= min(zone
->watermark_boost
+ pageblock_nr_pages
,
2526 * This function implements actual steal behaviour. If order is large enough,
2527 * we can steal whole pageblock. If not, we first move freepages in this
2528 * pageblock to our migratetype and determine how many already-allocated pages
2529 * are there in the pageblock with a compatible migratetype. If at least half
2530 * of pages are free or compatible, we can change migratetype of the pageblock
2531 * itself, so pages freed in the future will be put on the correct free list.
2533 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2534 unsigned int alloc_flags
, int start_type
, bool whole_block
)
2536 unsigned int current_order
= buddy_order(page
);
2537 int free_pages
, movable_pages
, alike_pages
;
2540 old_block_type
= get_pageblock_migratetype(page
);
2543 * This can happen due to races and we want to prevent broken
2544 * highatomic accounting.
2546 if (is_migrate_highatomic(old_block_type
))
2549 /* Take ownership for orders >= pageblock_order */
2550 if (current_order
>= pageblock_order
) {
2551 change_pageblock_range(page
, current_order
, start_type
);
2556 * Boost watermarks to increase reclaim pressure to reduce the
2557 * likelihood of future fallbacks. Wake kswapd now as the node
2558 * may be balanced overall and kswapd will not wake naturally.
2560 if (boost_watermark(zone
) && (alloc_flags
& ALLOC_KSWAPD
))
2561 set_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
2563 /* We are not allowed to try stealing from the whole block */
2567 free_pages
= move_freepages_block(zone
, page
, start_type
,
2570 * Determine how many pages are compatible with our allocation.
2571 * For movable allocation, it's the number of movable pages which
2572 * we just obtained. For other types it's a bit more tricky.
2574 if (start_type
== MIGRATE_MOVABLE
) {
2575 alike_pages
= movable_pages
;
2578 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2579 * to MOVABLE pageblock, consider all non-movable pages as
2580 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2581 * vice versa, be conservative since we can't distinguish the
2582 * exact migratetype of non-movable pages.
2584 if (old_block_type
== MIGRATE_MOVABLE
)
2585 alike_pages
= pageblock_nr_pages
2586 - (free_pages
+ movable_pages
);
2591 /* moving whole block can fail due to zone boundary conditions */
2596 * If a sufficient number of pages in the block are either free or of
2597 * comparable migratability as our allocation, claim the whole block.
2599 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2600 page_group_by_mobility_disabled
)
2601 set_pageblock_migratetype(page
, start_type
);
2606 move_to_free_list(page
, zone
, current_order
, start_type
);
2610 * Check whether there is a suitable fallback freepage with requested order.
2611 * If only_stealable is true, this function returns fallback_mt only if
2612 * we can steal other freepages all together. This would help to reduce
2613 * fragmentation due to mixed migratetype pages in one pageblock.
2615 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2616 int migratetype
, bool only_stealable
, bool *can_steal
)
2621 if (area
->nr_free
== 0)
2626 fallback_mt
= fallbacks
[migratetype
][i
];
2627 if (fallback_mt
== MIGRATE_TYPES
)
2630 if (free_area_empty(area
, fallback_mt
))
2633 if (can_steal_fallback(order
, migratetype
))
2636 if (!only_stealable
)
2647 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2648 * there are no empty page blocks that contain a page with a suitable order
2650 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2651 unsigned int alloc_order
)
2654 unsigned long max_managed
, flags
;
2657 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2658 * Check is race-prone but harmless.
2660 max_managed
= (zone_managed_pages(zone
) / 100) + pageblock_nr_pages
;
2661 if (zone
->nr_reserved_highatomic
>= max_managed
)
2664 spin_lock_irqsave(&zone
->lock
, flags
);
2666 /* Recheck the nr_reserved_highatomic limit under the lock */
2667 if (zone
->nr_reserved_highatomic
>= max_managed
)
2671 mt
= get_pageblock_migratetype(page
);
2672 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2673 && !is_migrate_cma(mt
)) {
2674 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2675 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2676 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2680 spin_unlock_irqrestore(&zone
->lock
, flags
);
2684 * Used when an allocation is about to fail under memory pressure. This
2685 * potentially hurts the reliability of high-order allocations when under
2686 * intense memory pressure but failed atomic allocations should be easier
2687 * to recover from than an OOM.
2689 * If @force is true, try to unreserve a pageblock even though highatomic
2690 * pageblock is exhausted.
2692 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2695 struct zonelist
*zonelist
= ac
->zonelist
;
2696 unsigned long flags
;
2703 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->highest_zoneidx
,
2706 * Preserve at least one pageblock unless memory pressure
2709 if (!force
&& zone
->nr_reserved_highatomic
<=
2713 spin_lock_irqsave(&zone
->lock
, flags
);
2714 for (order
= 0; order
< MAX_ORDER
; order
++) {
2715 struct free_area
*area
= &(zone
->free_area
[order
]);
2717 page
= get_page_from_free_area(area
, MIGRATE_HIGHATOMIC
);
2722 * In page freeing path, migratetype change is racy so
2723 * we can counter several free pages in a pageblock
2724 * in this loop althoug we changed the pageblock type
2725 * from highatomic to ac->migratetype. So we should
2726 * adjust the count once.
2728 if (is_migrate_highatomic_page(page
)) {
2730 * It should never happen but changes to
2731 * locking could inadvertently allow a per-cpu
2732 * drain to add pages to MIGRATE_HIGHATOMIC
2733 * while unreserving so be safe and watch for
2736 zone
->nr_reserved_highatomic
-= min(
2738 zone
->nr_reserved_highatomic
);
2742 * Convert to ac->migratetype and avoid the normal
2743 * pageblock stealing heuristics. Minimally, the caller
2744 * is doing the work and needs the pages. More
2745 * importantly, if the block was always converted to
2746 * MIGRATE_UNMOVABLE or another type then the number
2747 * of pageblocks that cannot be completely freed
2750 set_pageblock_migratetype(page
, ac
->migratetype
);
2751 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2754 spin_unlock_irqrestore(&zone
->lock
, flags
);
2758 spin_unlock_irqrestore(&zone
->lock
, flags
);
2765 * Try finding a free buddy page on the fallback list and put it on the free
2766 * list of requested migratetype, possibly along with other pages from the same
2767 * block, depending on fragmentation avoidance heuristics. Returns true if
2768 * fallback was found so that __rmqueue_smallest() can grab it.
2770 * The use of signed ints for order and current_order is a deliberate
2771 * deviation from the rest of this file, to make the for loop
2772 * condition simpler.
2774 static __always_inline
bool
2775 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
,
2776 unsigned int alloc_flags
)
2778 struct free_area
*area
;
2780 int min_order
= order
;
2786 * Do not steal pages from freelists belonging to other pageblocks
2787 * i.e. orders < pageblock_order. If there are no local zones free,
2788 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2790 if (alloc_flags
& ALLOC_NOFRAGMENT
)
2791 min_order
= pageblock_order
;
2794 * Find the largest available free page in the other list. This roughly
2795 * approximates finding the pageblock with the most free pages, which
2796 * would be too costly to do exactly.
2798 for (current_order
= MAX_ORDER
- 1; current_order
>= min_order
;
2800 area
= &(zone
->free_area
[current_order
]);
2801 fallback_mt
= find_suitable_fallback(area
, current_order
,
2802 start_migratetype
, false, &can_steal
);
2803 if (fallback_mt
== -1)
2807 * We cannot steal all free pages from the pageblock and the
2808 * requested migratetype is movable. In that case it's better to
2809 * steal and split the smallest available page instead of the
2810 * largest available page, because even if the next movable
2811 * allocation falls back into a different pageblock than this
2812 * one, it won't cause permanent fragmentation.
2814 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2815 && current_order
> order
)
2824 for (current_order
= order
; current_order
< MAX_ORDER
;
2826 area
= &(zone
->free_area
[current_order
]);
2827 fallback_mt
= find_suitable_fallback(area
, current_order
,
2828 start_migratetype
, false, &can_steal
);
2829 if (fallback_mt
!= -1)
2834 * This should not happen - we already found a suitable fallback
2835 * when looking for the largest page.
2837 VM_BUG_ON(current_order
== MAX_ORDER
);
2840 page
= get_page_from_free_area(area
, fallback_mt
);
2842 steal_suitable_fallback(zone
, page
, alloc_flags
, start_migratetype
,
2845 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2846 start_migratetype
, fallback_mt
);
2853 * Do the hard work of removing an element from the buddy allocator.
2854 * Call me with the zone->lock already held.
2856 static __always_inline
struct page
*
2857 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
,
2858 unsigned int alloc_flags
)
2862 if (IS_ENABLED(CONFIG_CMA
)) {
2864 * Balance movable allocations between regular and CMA areas by
2865 * allocating from CMA when over half of the zone's free memory
2866 * is in the CMA area.
2868 if (alloc_flags
& ALLOC_CMA
&&
2869 zone_page_state(zone
, NR_FREE_CMA_PAGES
) >
2870 zone_page_state(zone
, NR_FREE_PAGES
) / 2) {
2871 page
= __rmqueue_cma_fallback(zone
, order
);
2877 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2878 if (unlikely(!page
)) {
2879 if (alloc_flags
& ALLOC_CMA
)
2880 page
= __rmqueue_cma_fallback(zone
, order
);
2882 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
,
2888 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2893 * Obtain a specified number of elements from the buddy allocator, all under
2894 * a single hold of the lock, for efficiency. Add them to the supplied list.
2895 * Returns the number of new pages which were placed at *list.
2897 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2898 unsigned long count
, struct list_head
*list
,
2899 int migratetype
, unsigned int alloc_flags
)
2903 spin_lock(&zone
->lock
);
2904 for (i
= 0; i
< count
; ++i
) {
2905 struct page
*page
= __rmqueue(zone
, order
, migratetype
,
2907 if (unlikely(page
== NULL
))
2910 if (unlikely(check_pcp_refill(page
)))
2914 * Split buddy pages returned by expand() are received here in
2915 * physical page order. The page is added to the tail of
2916 * caller's list. From the callers perspective, the linked list
2917 * is ordered by page number under some conditions. This is
2918 * useful for IO devices that can forward direction from the
2919 * head, thus also in the physical page order. This is useful
2920 * for IO devices that can merge IO requests if the physical
2921 * pages are ordered properly.
2923 list_add_tail(&page
->lru
, list
);
2925 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2926 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2931 * i pages were removed from the buddy list even if some leak due
2932 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2933 * on i. Do not confuse with 'alloced' which is the number of
2934 * pages added to the pcp list.
2936 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2937 spin_unlock(&zone
->lock
);
2943 * Called from the vmstat counter updater to drain pagesets of this
2944 * currently executing processor on remote nodes after they have
2947 * Note that this function must be called with the thread pinned to
2948 * a single processor.
2950 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2952 unsigned long flags
;
2953 int to_drain
, batch
;
2955 local_irq_save(flags
);
2956 batch
= READ_ONCE(pcp
->batch
);
2957 to_drain
= min(pcp
->count
, batch
);
2959 free_pcppages_bulk(zone
, to_drain
, pcp
);
2960 local_irq_restore(flags
);
2965 * Drain pcplists of the indicated processor and zone.
2967 * The processor must either be the current processor and the
2968 * thread pinned to the current processor or a processor that
2971 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2973 unsigned long flags
;
2974 struct per_cpu_pageset
*pset
;
2975 struct per_cpu_pages
*pcp
;
2977 local_irq_save(flags
);
2978 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2982 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2983 local_irq_restore(flags
);
2987 * Drain pcplists of all zones on the indicated processor.
2989 * The processor must either be the current processor and the
2990 * thread pinned to the current processor or a processor that
2993 static void drain_pages(unsigned int cpu
)
2997 for_each_populated_zone(zone
) {
2998 drain_pages_zone(cpu
, zone
);
3003 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
3005 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
3006 * the single zone's pages.
3008 void drain_local_pages(struct zone
*zone
)
3010 int cpu
= smp_processor_id();
3013 drain_pages_zone(cpu
, zone
);
3018 static void drain_local_pages_wq(struct work_struct
*work
)
3020 struct pcpu_drain
*drain
;
3022 drain
= container_of(work
, struct pcpu_drain
, work
);
3025 * drain_all_pages doesn't use proper cpu hotplug protection so
3026 * we can race with cpu offline when the WQ can move this from
3027 * a cpu pinned worker to an unbound one. We can operate on a different
3028 * cpu which is allright but we also have to make sure to not move to
3032 drain_local_pages(drain
->zone
);
3037 * The implementation of drain_all_pages(), exposing an extra parameter to
3038 * drain on all cpus.
3040 * drain_all_pages() is optimized to only execute on cpus where pcplists are
3041 * not empty. The check for non-emptiness can however race with a free to
3042 * pcplist that has not yet increased the pcp->count from 0 to 1. Callers
3043 * that need the guarantee that every CPU has drained can disable the
3044 * optimizing racy check.
3046 static void __drain_all_pages(struct zone
*zone
, bool force_all_cpus
)
3051 * Allocate in the BSS so we wont require allocation in
3052 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
3054 static cpumask_t cpus_with_pcps
;
3057 * Make sure nobody triggers this path before mm_percpu_wq is fully
3060 if (WARN_ON_ONCE(!mm_percpu_wq
))
3064 * Do not drain if one is already in progress unless it's specific to
3065 * a zone. Such callers are primarily CMA and memory hotplug and need
3066 * the drain to be complete when the call returns.
3068 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
3071 mutex_lock(&pcpu_drain_mutex
);
3075 * We don't care about racing with CPU hotplug event
3076 * as offline notification will cause the notified
3077 * cpu to drain that CPU pcps and on_each_cpu_mask
3078 * disables preemption as part of its processing
3080 for_each_online_cpu(cpu
) {
3081 struct per_cpu_pageset
*pcp
;
3083 bool has_pcps
= false;
3085 if (force_all_cpus
) {
3087 * The pcp.count check is racy, some callers need a
3088 * guarantee that no cpu is missed.
3092 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3096 for_each_populated_zone(z
) {
3097 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
3098 if (pcp
->pcp
.count
) {
3106 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
3108 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
3111 for_each_cpu(cpu
, &cpus_with_pcps
) {
3112 struct pcpu_drain
*drain
= per_cpu_ptr(&pcpu_drain
, cpu
);
3115 INIT_WORK(&drain
->work
, drain_local_pages_wq
);
3116 queue_work_on(cpu
, mm_percpu_wq
, &drain
->work
);
3118 for_each_cpu(cpu
, &cpus_with_pcps
)
3119 flush_work(&per_cpu_ptr(&pcpu_drain
, cpu
)->work
);
3121 mutex_unlock(&pcpu_drain_mutex
);
3125 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
3127 * When zone parameter is non-NULL, spill just the single zone's pages.
3129 * Note that this can be extremely slow as the draining happens in a workqueue.
3131 void drain_all_pages(struct zone
*zone
)
3133 __drain_all_pages(zone
, false);
3136 #ifdef CONFIG_HIBERNATION
3139 * Touch the watchdog for every WD_PAGE_COUNT pages.
3141 #define WD_PAGE_COUNT (128*1024)
3143 void mark_free_pages(struct zone
*zone
)
3145 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
3146 unsigned long flags
;
3147 unsigned int order
, t
;
3150 if (zone_is_empty(zone
))
3153 spin_lock_irqsave(&zone
->lock
, flags
);
3155 max_zone_pfn
= zone_end_pfn(zone
);
3156 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
3157 if (pfn_valid(pfn
)) {
3158 page
= pfn_to_page(pfn
);
3160 if (!--page_count
) {
3161 touch_nmi_watchdog();
3162 page_count
= WD_PAGE_COUNT
;
3165 if (page_zone(page
) != zone
)
3168 if (!swsusp_page_is_forbidden(page
))
3169 swsusp_unset_page_free(page
);
3172 for_each_migratetype_order(order
, t
) {
3173 list_for_each_entry(page
,
3174 &zone
->free_area
[order
].free_list
[t
], lru
) {
3177 pfn
= page_to_pfn(page
);
3178 for (i
= 0; i
< (1UL << order
); i
++) {
3179 if (!--page_count
) {
3180 touch_nmi_watchdog();
3181 page_count
= WD_PAGE_COUNT
;
3183 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
3187 spin_unlock_irqrestore(&zone
->lock
, flags
);
3189 #endif /* CONFIG_PM */
3191 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
3195 if (!free_pcp_prepare(page
))
3198 migratetype
= get_pfnblock_migratetype(page
, pfn
);
3199 set_pcppage_migratetype(page
, migratetype
);
3203 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
3205 struct zone
*zone
= page_zone(page
);
3206 struct per_cpu_pages
*pcp
;
3209 migratetype
= get_pcppage_migratetype(page
);
3210 __count_vm_event(PGFREE
);
3213 * We only track unmovable, reclaimable and movable on pcp lists.
3214 * Free ISOLATE pages back to the allocator because they are being
3215 * offlined but treat HIGHATOMIC as movable pages so we can get those
3216 * areas back if necessary. Otherwise, we may have to free
3217 * excessively into the page allocator
3219 if (migratetype
>= MIGRATE_PCPTYPES
) {
3220 if (unlikely(is_migrate_isolate(migratetype
))) {
3221 free_one_page(zone
, page
, pfn
, 0, migratetype
,
3225 migratetype
= MIGRATE_MOVABLE
;
3228 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3229 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
3231 if (pcp
->count
>= READ_ONCE(pcp
->high
))
3232 free_pcppages_bulk(zone
, READ_ONCE(pcp
->batch
), pcp
);
3236 * Free a 0-order page
3238 void free_unref_page(struct page
*page
)
3240 unsigned long flags
;
3241 unsigned long pfn
= page_to_pfn(page
);
3243 if (!free_unref_page_prepare(page
, pfn
))
3246 local_irq_save(flags
);
3247 free_unref_page_commit(page
, pfn
);
3248 local_irq_restore(flags
);
3252 * Free a list of 0-order pages
3254 void free_unref_page_list(struct list_head
*list
)
3256 struct page
*page
, *next
;
3257 unsigned long flags
, pfn
;
3258 int batch_count
= 0;
3260 /* Prepare pages for freeing */
3261 list_for_each_entry_safe(page
, next
, list
, lru
) {
3262 pfn
= page_to_pfn(page
);
3263 if (!free_unref_page_prepare(page
, pfn
))
3264 list_del(&page
->lru
);
3265 set_page_private(page
, pfn
);
3268 local_irq_save(flags
);
3269 list_for_each_entry_safe(page
, next
, list
, lru
) {
3270 unsigned long pfn
= page_private(page
);
3272 set_page_private(page
, 0);
3273 trace_mm_page_free_batched(page
);
3274 free_unref_page_commit(page
, pfn
);
3277 * Guard against excessive IRQ disabled times when we get
3278 * a large list of pages to free.
3280 if (++batch_count
== SWAP_CLUSTER_MAX
) {
3281 local_irq_restore(flags
);
3283 local_irq_save(flags
);
3286 local_irq_restore(flags
);
3290 * split_page takes a non-compound higher-order page, and splits it into
3291 * n (1<<order) sub-pages: page[0..n]
3292 * Each sub-page must be freed individually.
3294 * Note: this is probably too low level an operation for use in drivers.
3295 * Please consult with lkml before using this in your driver.
3297 void split_page(struct page
*page
, unsigned int order
)
3301 VM_BUG_ON_PAGE(PageCompound(page
), page
);
3302 VM_BUG_ON_PAGE(!page_count(page
), page
);
3304 for (i
= 1; i
< (1 << order
); i
++)
3305 set_page_refcounted(page
+ i
);
3306 split_page_owner(page
, 1 << order
);
3307 split_page_memcg(page
, 1 << order
);
3309 EXPORT_SYMBOL_GPL(split_page
);
3311 int __isolate_free_page(struct page
*page
, unsigned int order
)
3313 unsigned long watermark
;
3317 BUG_ON(!PageBuddy(page
));
3319 zone
= page_zone(page
);
3320 mt
= get_pageblock_migratetype(page
);
3322 if (!is_migrate_isolate(mt
)) {
3324 * Obey watermarks as if the page was being allocated. We can
3325 * emulate a high-order watermark check with a raised order-0
3326 * watermark, because we already know our high-order page
3329 watermark
= zone
->_watermark
[WMARK_MIN
] + (1UL << order
);
3330 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
3333 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
3336 /* Remove page from free list */
3338 del_page_from_free_list(page
, zone
, order
);
3341 * Set the pageblock if the isolated page is at least half of a
3344 if (order
>= pageblock_order
- 1) {
3345 struct page
*endpage
= page
+ (1 << order
) - 1;
3346 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
3347 int mt
= get_pageblock_migratetype(page
);
3348 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
3349 && !is_migrate_highatomic(mt
))
3350 set_pageblock_migratetype(page
,
3356 return 1UL << order
;
3360 * __putback_isolated_page - Return a now-isolated page back where we got it
3361 * @page: Page that was isolated
3362 * @order: Order of the isolated page
3363 * @mt: The page's pageblock's migratetype
3365 * This function is meant to return a page pulled from the free lists via
3366 * __isolate_free_page back to the free lists they were pulled from.
3368 void __putback_isolated_page(struct page
*page
, unsigned int order
, int mt
)
3370 struct zone
*zone
= page_zone(page
);
3372 /* zone lock should be held when this function is called */
3373 lockdep_assert_held(&zone
->lock
);
3375 /* Return isolated page to tail of freelist. */
3376 __free_one_page(page
, page_to_pfn(page
), zone
, order
, mt
,
3377 FPI_SKIP_REPORT_NOTIFY
| FPI_TO_TAIL
);
3381 * Update NUMA hit/miss statistics
3383 * Must be called with interrupts disabled.
3385 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
3388 enum numa_stat_item local_stat
= NUMA_LOCAL
;
3390 /* skip numa counters update if numa stats is disabled */
3391 if (!static_branch_likely(&vm_numa_stat_key
))
3394 if (zone_to_nid(z
) != numa_node_id())
3395 local_stat
= NUMA_OTHER
;
3397 if (zone_to_nid(z
) == zone_to_nid(preferred_zone
))
3398 __inc_numa_state(z
, NUMA_HIT
);
3400 __inc_numa_state(z
, NUMA_MISS
);
3401 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
3403 __inc_numa_state(z
, local_stat
);
3407 /* Remove page from the per-cpu list, caller must protect the list */
3408 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
3409 unsigned int alloc_flags
,
3410 struct per_cpu_pages
*pcp
,
3411 struct list_head
*list
)
3416 if (list_empty(list
)) {
3417 pcp
->count
+= rmqueue_bulk(zone
, 0,
3418 READ_ONCE(pcp
->batch
), list
,
3419 migratetype
, alloc_flags
);
3420 if (unlikely(list_empty(list
)))
3424 page
= list_first_entry(list
, struct page
, lru
);
3425 list_del(&page
->lru
);
3427 } while (check_new_pcp(page
));
3432 /* Lock and remove page from the per-cpu list */
3433 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
3434 struct zone
*zone
, gfp_t gfp_flags
,
3435 int migratetype
, unsigned int alloc_flags
)
3437 struct per_cpu_pages
*pcp
;
3438 struct list_head
*list
;
3440 unsigned long flags
;
3442 local_irq_save(flags
);
3443 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3444 list
= &pcp
->lists
[migratetype
];
3445 page
= __rmqueue_pcplist(zone
, migratetype
, alloc_flags
, pcp
, list
);
3447 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1);
3448 zone_statistics(preferred_zone
, zone
);
3450 local_irq_restore(flags
);
3455 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3458 struct page
*rmqueue(struct zone
*preferred_zone
,
3459 struct zone
*zone
, unsigned int order
,
3460 gfp_t gfp_flags
, unsigned int alloc_flags
,
3463 unsigned long flags
;
3466 if (likely(order
== 0)) {
3468 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3469 * we need to skip it when CMA area isn't allowed.
3471 if (!IS_ENABLED(CONFIG_CMA
) || alloc_flags
& ALLOC_CMA
||
3472 migratetype
!= MIGRATE_MOVABLE
) {
3473 page
= rmqueue_pcplist(preferred_zone
, zone
, gfp_flags
,
3474 migratetype
, alloc_flags
);
3480 * We most definitely don't want callers attempting to
3481 * allocate greater than order-1 page units with __GFP_NOFAIL.
3483 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
3484 spin_lock_irqsave(&zone
->lock
, flags
);
3489 * order-0 request can reach here when the pcplist is skipped
3490 * due to non-CMA allocation context. HIGHATOMIC area is
3491 * reserved for high-order atomic allocation, so order-0
3492 * request should skip it.
3494 if (order
> 0 && alloc_flags
& ALLOC_HARDER
) {
3495 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
3497 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
3500 page
= __rmqueue(zone
, order
, migratetype
, alloc_flags
);
3501 } while (page
&& check_new_pages(page
, order
));
3502 spin_unlock(&zone
->lock
);
3505 __mod_zone_freepage_state(zone
, -(1 << order
),
3506 get_pcppage_migratetype(page
));
3508 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
3509 zone_statistics(preferred_zone
, zone
);
3510 local_irq_restore(flags
);
3513 /* Separate test+clear to avoid unnecessary atomics */
3514 if (test_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
)) {
3515 clear_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
3516 wakeup_kswapd(zone
, 0, 0, zone_idx(zone
));
3519 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
3523 local_irq_restore(flags
);
3527 #ifdef CONFIG_FAIL_PAGE_ALLOC
3530 struct fault_attr attr
;
3532 bool ignore_gfp_highmem
;
3533 bool ignore_gfp_reclaim
;
3535 } fail_page_alloc
= {
3536 .attr
= FAULT_ATTR_INITIALIZER
,
3537 .ignore_gfp_reclaim
= true,
3538 .ignore_gfp_highmem
= true,
3542 static int __init
setup_fail_page_alloc(char *str
)
3544 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
3546 __setup("fail_page_alloc=", setup_fail_page_alloc
);
3548 static bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3550 if (order
< fail_page_alloc
.min_order
)
3552 if (gfp_mask
& __GFP_NOFAIL
)
3554 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
3556 if (fail_page_alloc
.ignore_gfp_reclaim
&&
3557 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
3560 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
3563 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3565 static int __init
fail_page_alloc_debugfs(void)
3567 umode_t mode
= S_IFREG
| 0600;
3570 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
3571 &fail_page_alloc
.attr
);
3573 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
3574 &fail_page_alloc
.ignore_gfp_reclaim
);
3575 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
3576 &fail_page_alloc
.ignore_gfp_highmem
);
3577 debugfs_create_u32("min-order", mode
, dir
, &fail_page_alloc
.min_order
);
3582 late_initcall(fail_page_alloc_debugfs
);
3584 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3586 #else /* CONFIG_FAIL_PAGE_ALLOC */
3588 static inline bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3593 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3595 noinline
bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3597 return __should_fail_alloc_page(gfp_mask
, order
);
3599 ALLOW_ERROR_INJECTION(should_fail_alloc_page
, TRUE
);
3601 static inline long __zone_watermark_unusable_free(struct zone
*z
,
3602 unsigned int order
, unsigned int alloc_flags
)
3604 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3605 long unusable_free
= (1 << order
) - 1;
3608 * If the caller does not have rights to ALLOC_HARDER then subtract
3609 * the high-atomic reserves. This will over-estimate the size of the
3610 * atomic reserve but it avoids a search.
3612 if (likely(!alloc_harder
))
3613 unusable_free
+= z
->nr_reserved_highatomic
;
3616 /* If allocation can't use CMA areas don't use free CMA pages */
3617 if (!(alloc_flags
& ALLOC_CMA
))
3618 unusable_free
+= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3621 return unusable_free
;
3625 * Return true if free base pages are above 'mark'. For high-order checks it
3626 * will return true of the order-0 watermark is reached and there is at least
3627 * one free page of a suitable size. Checking now avoids taking the zone lock
3628 * to check in the allocation paths if no pages are free.
3630 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3631 int highest_zoneidx
, unsigned int alloc_flags
,
3636 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3638 /* free_pages may go negative - that's OK */
3639 free_pages
-= __zone_watermark_unusable_free(z
, order
, alloc_flags
);
3641 if (alloc_flags
& ALLOC_HIGH
)
3644 if (unlikely(alloc_harder
)) {
3646 * OOM victims can try even harder than normal ALLOC_HARDER
3647 * users on the grounds that it's definitely going to be in
3648 * the exit path shortly and free memory. Any allocation it
3649 * makes during the free path will be small and short-lived.
3651 if (alloc_flags
& ALLOC_OOM
)
3658 * Check watermarks for an order-0 allocation request. If these
3659 * are not met, then a high-order request also cannot go ahead
3660 * even if a suitable page happened to be free.
3662 if (free_pages
<= min
+ z
->lowmem_reserve
[highest_zoneidx
])
3665 /* If this is an order-0 request then the watermark is fine */
3669 /* For a high-order request, check at least one suitable page is free */
3670 for (o
= order
; o
< MAX_ORDER
; o
++) {
3671 struct free_area
*area
= &z
->free_area
[o
];
3677 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3678 if (!free_area_empty(area
, mt
))
3683 if ((alloc_flags
& ALLOC_CMA
) &&
3684 !free_area_empty(area
, MIGRATE_CMA
)) {
3688 if (alloc_harder
&& !free_area_empty(area
, MIGRATE_HIGHATOMIC
))
3694 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3695 int highest_zoneidx
, unsigned int alloc_flags
)
3697 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3698 zone_page_state(z
, NR_FREE_PAGES
));
3701 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3702 unsigned long mark
, int highest_zoneidx
,
3703 unsigned int alloc_flags
, gfp_t gfp_mask
)
3707 free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3710 * Fast check for order-0 only. If this fails then the reserves
3711 * need to be calculated.
3716 fast_free
= free_pages
;
3717 fast_free
-= __zone_watermark_unusable_free(z
, 0, alloc_flags
);
3718 if (fast_free
> mark
+ z
->lowmem_reserve
[highest_zoneidx
])
3722 if (__zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3726 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3727 * when checking the min watermark. The min watermark is the
3728 * point where boosting is ignored so that kswapd is woken up
3729 * when below the low watermark.
3731 if (unlikely(!order
&& (gfp_mask
& __GFP_ATOMIC
) && z
->watermark_boost
3732 && ((alloc_flags
& ALLOC_WMARK_MASK
) == WMARK_MIN
))) {
3733 mark
= z
->_watermark
[WMARK_MIN
];
3734 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
,
3735 alloc_flags
, free_pages
);
3741 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3742 unsigned long mark
, int highest_zoneidx
)
3744 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3746 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3747 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3749 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, 0,
3754 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3756 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3757 node_reclaim_distance
;
3759 #else /* CONFIG_NUMA */
3760 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3764 #endif /* CONFIG_NUMA */
3767 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3768 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3769 * premature use of a lower zone may cause lowmem pressure problems that
3770 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3771 * probably too small. It only makes sense to spread allocations to avoid
3772 * fragmentation between the Normal and DMA32 zones.
3774 static inline unsigned int
3775 alloc_flags_nofragment(struct zone
*zone
, gfp_t gfp_mask
)
3777 unsigned int alloc_flags
;
3780 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3783 alloc_flags
= (__force
int) (gfp_mask
& __GFP_KSWAPD_RECLAIM
);
3785 #ifdef CONFIG_ZONE_DMA32
3789 if (zone_idx(zone
) != ZONE_NORMAL
)
3793 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3794 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3795 * on UMA that if Normal is populated then so is DMA32.
3797 BUILD_BUG_ON(ZONE_NORMAL
- ZONE_DMA32
!= 1);
3798 if (nr_online_nodes
> 1 && !populated_zone(--zone
))
3801 alloc_flags
|= ALLOC_NOFRAGMENT
;
3802 #endif /* CONFIG_ZONE_DMA32 */
3806 static inline unsigned int current_alloc_flags(gfp_t gfp_mask
,
3807 unsigned int alloc_flags
)
3810 unsigned int pflags
= current
->flags
;
3812 if (!(pflags
& PF_MEMALLOC_NOCMA
) &&
3813 gfp_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3814 alloc_flags
|= ALLOC_CMA
;
3821 * get_page_from_freelist goes through the zonelist trying to allocate
3824 static struct page
*
3825 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3826 const struct alloc_context
*ac
)
3830 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3835 * Scan zonelist, looking for a zone with enough free.
3836 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3838 no_fallback
= alloc_flags
& ALLOC_NOFRAGMENT
;
3839 z
= ac
->preferred_zoneref
;
3840 for_next_zone_zonelist_nodemask(zone
, z
, ac
->highest_zoneidx
,
3845 if (cpusets_enabled() &&
3846 (alloc_flags
& ALLOC_CPUSET
) &&
3847 !__cpuset_zone_allowed(zone
, gfp_mask
))
3850 * When allocating a page cache page for writing, we
3851 * want to get it from a node that is within its dirty
3852 * limit, such that no single node holds more than its
3853 * proportional share of globally allowed dirty pages.
3854 * The dirty limits take into account the node's
3855 * lowmem reserves and high watermark so that kswapd
3856 * should be able to balance it without having to
3857 * write pages from its LRU list.
3859 * XXX: For now, allow allocations to potentially
3860 * exceed the per-node dirty limit in the slowpath
3861 * (spread_dirty_pages unset) before going into reclaim,
3862 * which is important when on a NUMA setup the allowed
3863 * nodes are together not big enough to reach the
3864 * global limit. The proper fix for these situations
3865 * will require awareness of nodes in the
3866 * dirty-throttling and the flusher threads.
3868 if (ac
->spread_dirty_pages
) {
3869 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3872 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3873 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3878 if (no_fallback
&& nr_online_nodes
> 1 &&
3879 zone
!= ac
->preferred_zoneref
->zone
) {
3883 * If moving to a remote node, retry but allow
3884 * fragmenting fallbacks. Locality is more important
3885 * than fragmentation avoidance.
3887 local_nid
= zone_to_nid(ac
->preferred_zoneref
->zone
);
3888 if (zone_to_nid(zone
) != local_nid
) {
3889 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3894 mark
= wmark_pages(zone
, alloc_flags
& ALLOC_WMARK_MASK
);
3895 if (!zone_watermark_fast(zone
, order
, mark
,
3896 ac
->highest_zoneidx
, alloc_flags
,
3900 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3902 * Watermark failed for this zone, but see if we can
3903 * grow this zone if it contains deferred pages.
3905 if (static_branch_unlikely(&deferred_pages
)) {
3906 if (_deferred_grow_zone(zone
, order
))
3910 /* Checked here to keep the fast path fast */
3911 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3912 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3915 if (node_reclaim_mode
== 0 ||
3916 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3919 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3921 case NODE_RECLAIM_NOSCAN
:
3924 case NODE_RECLAIM_FULL
:
3925 /* scanned but unreclaimable */
3928 /* did we reclaim enough */
3929 if (zone_watermark_ok(zone
, order
, mark
,
3930 ac
->highest_zoneidx
, alloc_flags
))
3938 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3939 gfp_mask
, alloc_flags
, ac
->migratetype
);
3941 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3944 * If this is a high-order atomic allocation then check
3945 * if the pageblock should be reserved for the future
3947 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3948 reserve_highatomic_pageblock(page
, zone
, order
);
3952 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3953 /* Try again if zone has deferred pages */
3954 if (static_branch_unlikely(&deferred_pages
)) {
3955 if (_deferred_grow_zone(zone
, order
))
3963 * It's possible on a UMA machine to get through all zones that are
3964 * fragmented. If avoiding fragmentation, reset and try again.
3967 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3974 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3976 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3979 * This documents exceptions given to allocations in certain
3980 * contexts that are allowed to allocate outside current's set
3983 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3984 if (tsk_is_oom_victim(current
) ||
3985 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3986 filter
&= ~SHOW_MEM_FILTER_NODES
;
3987 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3988 filter
&= ~SHOW_MEM_FILTER_NODES
;
3990 show_mem(filter
, nodemask
);
3993 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3995 struct va_format vaf
;
3997 static DEFINE_RATELIMIT_STATE(nopage_rs
, 10*HZ
, 1);
3999 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
4002 va_start(args
, fmt
);
4005 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
4006 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
4007 nodemask_pr_args(nodemask
));
4010 cpuset_print_current_mems_allowed();
4013 warn_alloc_show_mem(gfp_mask
, nodemask
);
4016 static inline struct page
*
4017 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
4018 unsigned int alloc_flags
,
4019 const struct alloc_context
*ac
)
4023 page
= get_page_from_freelist(gfp_mask
, order
,
4024 alloc_flags
|ALLOC_CPUSET
, ac
);
4026 * fallback to ignore cpuset restriction if our nodes
4030 page
= get_page_from_freelist(gfp_mask
, order
,
4036 static inline struct page
*
4037 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
4038 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
4040 struct oom_control oc
= {
4041 .zonelist
= ac
->zonelist
,
4042 .nodemask
= ac
->nodemask
,
4044 .gfp_mask
= gfp_mask
,
4049 *did_some_progress
= 0;
4052 * Acquire the oom lock. If that fails, somebody else is
4053 * making progress for us.
4055 if (!mutex_trylock(&oom_lock
)) {
4056 *did_some_progress
= 1;
4057 schedule_timeout_uninterruptible(1);
4062 * Go through the zonelist yet one more time, keep very high watermark
4063 * here, this is only to catch a parallel oom killing, we must fail if
4064 * we're still under heavy pressure. But make sure that this reclaim
4065 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
4066 * allocation which will never fail due to oom_lock already held.
4068 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
4069 ~__GFP_DIRECT_RECLAIM
, order
,
4070 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
4074 /* Coredumps can quickly deplete all memory reserves */
4075 if (current
->flags
& PF_DUMPCORE
)
4077 /* The OOM killer will not help higher order allocs */
4078 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4081 * We have already exhausted all our reclaim opportunities without any
4082 * success so it is time to admit defeat. We will skip the OOM killer
4083 * because it is very likely that the caller has a more reasonable
4084 * fallback than shooting a random task.
4086 * The OOM killer may not free memory on a specific node.
4088 if (gfp_mask
& (__GFP_RETRY_MAYFAIL
| __GFP_THISNODE
))
4090 /* The OOM killer does not needlessly kill tasks for lowmem */
4091 if (ac
->highest_zoneidx
< ZONE_NORMAL
)
4093 if (pm_suspended_storage())
4096 * XXX: GFP_NOFS allocations should rather fail than rely on
4097 * other request to make a forward progress.
4098 * We are in an unfortunate situation where out_of_memory cannot
4099 * do much for this context but let's try it to at least get
4100 * access to memory reserved if the current task is killed (see
4101 * out_of_memory). Once filesystems are ready to handle allocation
4102 * failures more gracefully we should just bail out here.
4105 /* Exhausted what can be done so it's blame time */
4106 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
4107 *did_some_progress
= 1;
4110 * Help non-failing allocations by giving them access to memory
4113 if (gfp_mask
& __GFP_NOFAIL
)
4114 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
4115 ALLOC_NO_WATERMARKS
, ac
);
4118 mutex_unlock(&oom_lock
);
4123 * Maximum number of compaction retries wit a progress before OOM
4124 * killer is consider as the only way to move forward.
4126 #define MAX_COMPACT_RETRIES 16
4128 #ifdef CONFIG_COMPACTION
4129 /* Try memory compaction for high-order allocations before reclaim */
4130 static struct page
*
4131 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4132 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4133 enum compact_priority prio
, enum compact_result
*compact_result
)
4135 struct page
*page
= NULL
;
4136 unsigned long pflags
;
4137 unsigned int noreclaim_flag
;
4142 psi_memstall_enter(&pflags
);
4143 noreclaim_flag
= memalloc_noreclaim_save();
4145 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
4148 memalloc_noreclaim_restore(noreclaim_flag
);
4149 psi_memstall_leave(&pflags
);
4152 * At least in one zone compaction wasn't deferred or skipped, so let's
4153 * count a compaction stall
4155 count_vm_event(COMPACTSTALL
);
4157 /* Prep a captured page if available */
4159 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
4161 /* Try get a page from the freelist if available */
4163 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4166 struct zone
*zone
= page_zone(page
);
4168 zone
->compact_blockskip_flush
= false;
4169 compaction_defer_reset(zone
, order
, true);
4170 count_vm_event(COMPACTSUCCESS
);
4175 * It's bad if compaction run occurs and fails. The most likely reason
4176 * is that pages exist, but not enough to satisfy watermarks.
4178 count_vm_event(COMPACTFAIL
);
4186 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
4187 enum compact_result compact_result
,
4188 enum compact_priority
*compact_priority
,
4189 int *compaction_retries
)
4191 int max_retries
= MAX_COMPACT_RETRIES
;
4194 int retries
= *compaction_retries
;
4195 enum compact_priority priority
= *compact_priority
;
4200 if (compaction_made_progress(compact_result
))
4201 (*compaction_retries
)++;
4204 * compaction considers all the zone as desperately out of memory
4205 * so it doesn't really make much sense to retry except when the
4206 * failure could be caused by insufficient priority
4208 if (compaction_failed(compact_result
))
4209 goto check_priority
;
4212 * compaction was skipped because there are not enough order-0 pages
4213 * to work with, so we retry only if it looks like reclaim can help.
4215 if (compaction_needs_reclaim(compact_result
)) {
4216 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
4221 * make sure the compaction wasn't deferred or didn't bail out early
4222 * due to locks contention before we declare that we should give up.
4223 * But the next retry should use a higher priority if allowed, so
4224 * we don't just keep bailing out endlessly.
4226 if (compaction_withdrawn(compact_result
)) {
4227 goto check_priority
;
4231 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4232 * costly ones because they are de facto nofail and invoke OOM
4233 * killer to move on while costly can fail and users are ready
4234 * to cope with that. 1/4 retries is rather arbitrary but we
4235 * would need much more detailed feedback from compaction to
4236 * make a better decision.
4238 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4240 if (*compaction_retries
<= max_retries
) {
4246 * Make sure there are attempts at the highest priority if we exhausted
4247 * all retries or failed at the lower priorities.
4250 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
4251 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
4253 if (*compact_priority
> min_priority
) {
4254 (*compact_priority
)--;
4255 *compaction_retries
= 0;
4259 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
4263 static inline struct page
*
4264 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4265 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4266 enum compact_priority prio
, enum compact_result
*compact_result
)
4268 *compact_result
= COMPACT_SKIPPED
;
4273 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
4274 enum compact_result compact_result
,
4275 enum compact_priority
*compact_priority
,
4276 int *compaction_retries
)
4281 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
4285 * There are setups with compaction disabled which would prefer to loop
4286 * inside the allocator rather than hit the oom killer prematurely.
4287 * Let's give them a good hope and keep retrying while the order-0
4288 * watermarks are OK.
4290 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4291 ac
->highest_zoneidx
, ac
->nodemask
) {
4292 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
4293 ac
->highest_zoneidx
, alloc_flags
))
4298 #endif /* CONFIG_COMPACTION */
4300 #ifdef CONFIG_LOCKDEP
4301 static struct lockdep_map __fs_reclaim_map
=
4302 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
4304 static bool __need_reclaim(gfp_t gfp_mask
)
4306 /* no reclaim without waiting on it */
4307 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
4310 /* this guy won't enter reclaim */
4311 if (current
->flags
& PF_MEMALLOC
)
4314 if (gfp_mask
& __GFP_NOLOCKDEP
)
4320 void __fs_reclaim_acquire(void)
4322 lock_map_acquire(&__fs_reclaim_map
);
4325 void __fs_reclaim_release(void)
4327 lock_map_release(&__fs_reclaim_map
);
4330 void fs_reclaim_acquire(gfp_t gfp_mask
)
4332 gfp_mask
= current_gfp_context(gfp_mask
);
4334 if (__need_reclaim(gfp_mask
)) {
4335 if (gfp_mask
& __GFP_FS
)
4336 __fs_reclaim_acquire();
4338 #ifdef CONFIG_MMU_NOTIFIER
4339 lock_map_acquire(&__mmu_notifier_invalidate_range_start_map
);
4340 lock_map_release(&__mmu_notifier_invalidate_range_start_map
);
4345 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
4347 void fs_reclaim_release(gfp_t gfp_mask
)
4349 gfp_mask
= current_gfp_context(gfp_mask
);
4351 if (__need_reclaim(gfp_mask
)) {
4352 if (gfp_mask
& __GFP_FS
)
4353 __fs_reclaim_release();
4356 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
4359 /* Perform direct synchronous page reclaim */
4360 static unsigned long
4361 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
4362 const struct alloc_context
*ac
)
4364 unsigned int noreclaim_flag
;
4365 unsigned long pflags
, progress
;
4369 /* We now go into synchronous reclaim */
4370 cpuset_memory_pressure_bump();
4371 psi_memstall_enter(&pflags
);
4372 fs_reclaim_acquire(gfp_mask
);
4373 noreclaim_flag
= memalloc_noreclaim_save();
4375 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
4378 memalloc_noreclaim_restore(noreclaim_flag
);
4379 fs_reclaim_release(gfp_mask
);
4380 psi_memstall_leave(&pflags
);
4387 /* The really slow allocator path where we enter direct reclaim */
4388 static inline struct page
*
4389 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
4390 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4391 unsigned long *did_some_progress
)
4393 struct page
*page
= NULL
;
4394 bool drained
= false;
4396 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
4397 if (unlikely(!(*did_some_progress
)))
4401 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4404 * If an allocation failed after direct reclaim, it could be because
4405 * pages are pinned on the per-cpu lists or in high alloc reserves.
4406 * Shrink them and try again
4408 if (!page
&& !drained
) {
4409 unreserve_highatomic_pageblock(ac
, false);
4410 drain_all_pages(NULL
);
4418 static void wake_all_kswapds(unsigned int order
, gfp_t gfp_mask
,
4419 const struct alloc_context
*ac
)
4423 pg_data_t
*last_pgdat
= NULL
;
4424 enum zone_type highest_zoneidx
= ac
->highest_zoneidx
;
4426 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, highest_zoneidx
,
4428 if (last_pgdat
!= zone
->zone_pgdat
)
4429 wakeup_kswapd(zone
, gfp_mask
, order
, highest_zoneidx
);
4430 last_pgdat
= zone
->zone_pgdat
;
4434 static inline unsigned int
4435 gfp_to_alloc_flags(gfp_t gfp_mask
)
4437 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
4440 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4441 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4442 * to save two branches.
4444 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
4445 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM
!= (__force gfp_t
) ALLOC_KSWAPD
);
4448 * The caller may dip into page reserves a bit more if the caller
4449 * cannot run direct reclaim, or if the caller has realtime scheduling
4450 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4451 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4453 alloc_flags
|= (__force
int)
4454 (gfp_mask
& (__GFP_HIGH
| __GFP_KSWAPD_RECLAIM
));
4456 if (gfp_mask
& __GFP_ATOMIC
) {
4458 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4459 * if it can't schedule.
4461 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
4462 alloc_flags
|= ALLOC_HARDER
;
4464 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4465 * comment for __cpuset_node_allowed().
4467 alloc_flags
&= ~ALLOC_CPUSET
;
4468 } else if (unlikely(rt_task(current
)) && !in_interrupt())
4469 alloc_flags
|= ALLOC_HARDER
;
4471 alloc_flags
= current_alloc_flags(gfp_mask
, alloc_flags
);
4476 static bool oom_reserves_allowed(struct task_struct
*tsk
)
4478 if (!tsk_is_oom_victim(tsk
))
4482 * !MMU doesn't have oom reaper so give access to memory reserves
4483 * only to the thread with TIF_MEMDIE set
4485 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
4492 * Distinguish requests which really need access to full memory
4493 * reserves from oom victims which can live with a portion of it
4495 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
4497 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
4499 if (gfp_mask
& __GFP_MEMALLOC
)
4500 return ALLOC_NO_WATERMARKS
;
4501 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
4502 return ALLOC_NO_WATERMARKS
;
4503 if (!in_interrupt()) {
4504 if (current
->flags
& PF_MEMALLOC
)
4505 return ALLOC_NO_WATERMARKS
;
4506 else if (oom_reserves_allowed(current
))
4513 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
4515 return !!__gfp_pfmemalloc_flags(gfp_mask
);
4519 * Checks whether it makes sense to retry the reclaim to make a forward progress
4520 * for the given allocation request.
4522 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4523 * without success, or when we couldn't even meet the watermark if we
4524 * reclaimed all remaining pages on the LRU lists.
4526 * Returns true if a retry is viable or false to enter the oom path.
4529 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
4530 struct alloc_context
*ac
, int alloc_flags
,
4531 bool did_some_progress
, int *no_progress_loops
)
4538 * Costly allocations might have made a progress but this doesn't mean
4539 * their order will become available due to high fragmentation so
4540 * always increment the no progress counter for them
4542 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
4543 *no_progress_loops
= 0;
4545 (*no_progress_loops
)++;
4548 * Make sure we converge to OOM if we cannot make any progress
4549 * several times in the row.
4551 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
4552 /* Before OOM, exhaust highatomic_reserve */
4553 return unreserve_highatomic_pageblock(ac
, true);
4557 * Keep reclaiming pages while there is a chance this will lead
4558 * somewhere. If none of the target zones can satisfy our allocation
4559 * request even if all reclaimable pages are considered then we are
4560 * screwed and have to go OOM.
4562 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4563 ac
->highest_zoneidx
, ac
->nodemask
) {
4564 unsigned long available
;
4565 unsigned long reclaimable
;
4566 unsigned long min_wmark
= min_wmark_pages(zone
);
4569 available
= reclaimable
= zone_reclaimable_pages(zone
);
4570 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
4573 * Would the allocation succeed if we reclaimed all
4574 * reclaimable pages?
4576 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
4577 ac
->highest_zoneidx
, alloc_flags
, available
);
4578 trace_reclaim_retry_zone(z
, order
, reclaimable
,
4579 available
, min_wmark
, *no_progress_loops
, wmark
);
4582 * If we didn't make any progress and have a lot of
4583 * dirty + writeback pages then we should wait for
4584 * an IO to complete to slow down the reclaim and
4585 * prevent from pre mature OOM
4587 if (!did_some_progress
) {
4588 unsigned long write_pending
;
4590 write_pending
= zone_page_state_snapshot(zone
,
4591 NR_ZONE_WRITE_PENDING
);
4593 if (2 * write_pending
> reclaimable
) {
4594 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4606 * Memory allocation/reclaim might be called from a WQ context and the
4607 * current implementation of the WQ concurrency control doesn't
4608 * recognize that a particular WQ is congested if the worker thread is
4609 * looping without ever sleeping. Therefore we have to do a short sleep
4610 * here rather than calling cond_resched().
4612 if (current
->flags
& PF_WQ_WORKER
)
4613 schedule_timeout_uninterruptible(1);
4620 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
4623 * It's possible that cpuset's mems_allowed and the nodemask from
4624 * mempolicy don't intersect. This should be normally dealt with by
4625 * policy_nodemask(), but it's possible to race with cpuset update in
4626 * such a way the check therein was true, and then it became false
4627 * before we got our cpuset_mems_cookie here.
4628 * This assumes that for all allocations, ac->nodemask can come only
4629 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4630 * when it does not intersect with the cpuset restrictions) or the
4631 * caller can deal with a violated nodemask.
4633 if (cpusets_enabled() && ac
->nodemask
&&
4634 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
4635 ac
->nodemask
= NULL
;
4640 * When updating a task's mems_allowed or mempolicy nodemask, it is
4641 * possible to race with parallel threads in such a way that our
4642 * allocation can fail while the mask is being updated. If we are about
4643 * to fail, check if the cpuset changed during allocation and if so,
4646 if (read_mems_allowed_retry(cpuset_mems_cookie
))
4652 static inline struct page
*
4653 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
4654 struct alloc_context
*ac
)
4656 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
4657 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
4658 struct page
*page
= NULL
;
4659 unsigned int alloc_flags
;
4660 unsigned long did_some_progress
;
4661 enum compact_priority compact_priority
;
4662 enum compact_result compact_result
;
4663 int compaction_retries
;
4664 int no_progress_loops
;
4665 unsigned int cpuset_mems_cookie
;
4669 * We also sanity check to catch abuse of atomic reserves being used by
4670 * callers that are not in atomic context.
4672 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
4673 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
4674 gfp_mask
&= ~__GFP_ATOMIC
;
4677 compaction_retries
= 0;
4678 no_progress_loops
= 0;
4679 compact_priority
= DEF_COMPACT_PRIORITY
;
4680 cpuset_mems_cookie
= read_mems_allowed_begin();
4683 * The fast path uses conservative alloc_flags to succeed only until
4684 * kswapd needs to be woken up, and to avoid the cost of setting up
4685 * alloc_flags precisely. So we do that now.
4687 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
4690 * We need to recalculate the starting point for the zonelist iterator
4691 * because we might have used different nodemask in the fast path, or
4692 * there was a cpuset modification and we are retrying - otherwise we
4693 * could end up iterating over non-eligible zones endlessly.
4695 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4696 ac
->highest_zoneidx
, ac
->nodemask
);
4697 if (!ac
->preferred_zoneref
->zone
)
4700 if (alloc_flags
& ALLOC_KSWAPD
)
4701 wake_all_kswapds(order
, gfp_mask
, ac
);
4704 * The adjusted alloc_flags might result in immediate success, so try
4707 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4712 * For costly allocations, try direct compaction first, as it's likely
4713 * that we have enough base pages and don't need to reclaim. For non-
4714 * movable high-order allocations, do that as well, as compaction will
4715 * try prevent permanent fragmentation by migrating from blocks of the
4717 * Don't try this for allocations that are allowed to ignore
4718 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4720 if (can_direct_reclaim
&&
4722 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
4723 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
4724 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
4726 INIT_COMPACT_PRIORITY
,
4732 * Checks for costly allocations with __GFP_NORETRY, which
4733 * includes some THP page fault allocations
4735 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
4737 * If allocating entire pageblock(s) and compaction
4738 * failed because all zones are below low watermarks
4739 * or is prohibited because it recently failed at this
4740 * order, fail immediately unless the allocator has
4741 * requested compaction and reclaim retry.
4744 * - potentially very expensive because zones are far
4745 * below their low watermarks or this is part of very
4746 * bursty high order allocations,
4747 * - not guaranteed to help because isolate_freepages()
4748 * may not iterate over freed pages as part of its
4750 * - unlikely to make entire pageblocks free on its
4753 if (compact_result
== COMPACT_SKIPPED
||
4754 compact_result
== COMPACT_DEFERRED
)
4758 * Looks like reclaim/compaction is worth trying, but
4759 * sync compaction could be very expensive, so keep
4760 * using async compaction.
4762 compact_priority
= INIT_COMPACT_PRIORITY
;
4767 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4768 if (alloc_flags
& ALLOC_KSWAPD
)
4769 wake_all_kswapds(order
, gfp_mask
, ac
);
4771 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4773 alloc_flags
= current_alloc_flags(gfp_mask
, reserve_flags
);
4776 * Reset the nodemask and zonelist iterators if memory policies can be
4777 * ignored. These allocations are high priority and system rather than
4780 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4781 ac
->nodemask
= NULL
;
4782 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4783 ac
->highest_zoneidx
, ac
->nodemask
);
4786 /* Attempt with potentially adjusted zonelist and alloc_flags */
4787 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4791 /* Caller is not willing to reclaim, we can't balance anything */
4792 if (!can_direct_reclaim
)
4795 /* Avoid recursion of direct reclaim */
4796 if (current
->flags
& PF_MEMALLOC
)
4799 /* Try direct reclaim and then allocating */
4800 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4801 &did_some_progress
);
4805 /* Try direct compaction and then allocating */
4806 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4807 compact_priority
, &compact_result
);
4811 /* Do not loop if specifically requested */
4812 if (gfp_mask
& __GFP_NORETRY
)
4816 * Do not retry costly high order allocations unless they are
4817 * __GFP_RETRY_MAYFAIL
4819 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4822 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4823 did_some_progress
> 0, &no_progress_loops
))
4827 * It doesn't make any sense to retry for the compaction if the order-0
4828 * reclaim is not able to make any progress because the current
4829 * implementation of the compaction depends on the sufficient amount
4830 * of free memory (see __compaction_suitable)
4832 if (did_some_progress
> 0 &&
4833 should_compact_retry(ac
, order
, alloc_flags
,
4834 compact_result
, &compact_priority
,
4835 &compaction_retries
))
4839 /* Deal with possible cpuset update races before we start OOM killing */
4840 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4843 /* Reclaim has failed us, start killing things */
4844 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4848 /* Avoid allocations with no watermarks from looping endlessly */
4849 if (tsk_is_oom_victim(current
) &&
4850 (alloc_flags
& ALLOC_OOM
||
4851 (gfp_mask
& __GFP_NOMEMALLOC
)))
4854 /* Retry as long as the OOM killer is making progress */
4855 if (did_some_progress
) {
4856 no_progress_loops
= 0;
4861 /* Deal with possible cpuset update races before we fail */
4862 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4866 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4869 if (gfp_mask
& __GFP_NOFAIL
) {
4871 * All existing users of the __GFP_NOFAIL are blockable, so warn
4872 * of any new users that actually require GFP_NOWAIT
4874 if (WARN_ON_ONCE(!can_direct_reclaim
))
4878 * PF_MEMALLOC request from this context is rather bizarre
4879 * because we cannot reclaim anything and only can loop waiting
4880 * for somebody to do a work for us
4882 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4885 * non failing costly orders are a hard requirement which we
4886 * are not prepared for much so let's warn about these users
4887 * so that we can identify them and convert them to something
4890 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4893 * Help non-failing allocations by giving them access to memory
4894 * reserves but do not use ALLOC_NO_WATERMARKS because this
4895 * could deplete whole memory reserves which would just make
4896 * the situation worse
4898 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4906 warn_alloc(gfp_mask
, ac
->nodemask
,
4907 "page allocation failure: order:%u", order
);
4912 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4913 int preferred_nid
, nodemask_t
*nodemask
,
4914 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4915 unsigned int *alloc_flags
)
4917 ac
->highest_zoneidx
= gfp_zone(gfp_mask
);
4918 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4919 ac
->nodemask
= nodemask
;
4920 ac
->migratetype
= gfp_migratetype(gfp_mask
);
4922 if (cpusets_enabled()) {
4923 *alloc_mask
|= __GFP_HARDWALL
;
4925 * When we are in the interrupt context, it is irrelevant
4926 * to the current task context. It means that any node ok.
4928 if (!in_interrupt() && !ac
->nodemask
)
4929 ac
->nodemask
= &cpuset_current_mems_allowed
;
4931 *alloc_flags
|= ALLOC_CPUSET
;
4934 fs_reclaim_acquire(gfp_mask
);
4935 fs_reclaim_release(gfp_mask
);
4937 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4939 if (should_fail_alloc_page(gfp_mask
, order
))
4942 *alloc_flags
= current_alloc_flags(gfp_mask
, *alloc_flags
);
4944 /* Dirty zone balancing only done in the fast path */
4945 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4948 * The preferred zone is used for statistics but crucially it is
4949 * also used as the starting point for the zonelist iterator. It
4950 * may get reset for allocations that ignore memory policies.
4952 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4953 ac
->highest_zoneidx
, ac
->nodemask
);
4959 * This is the 'heart' of the zoned buddy allocator.
4962 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4963 nodemask_t
*nodemask
)
4966 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4967 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4968 struct alloc_context ac
= { };
4971 * There are several places where we assume that the order value is sane
4972 * so bail out early if the request is out of bound.
4974 if (unlikely(order
>= MAX_ORDER
)) {
4975 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
4979 gfp_mask
&= gfp_allowed_mask
;
4980 alloc_mask
= gfp_mask
;
4981 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4985 * Forbid the first pass from falling back to types that fragment
4986 * memory until all local zones are considered.
4988 alloc_flags
|= alloc_flags_nofragment(ac
.preferred_zoneref
->zone
, gfp_mask
);
4990 /* First allocation attempt */
4991 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4996 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4997 * resp. GFP_NOIO which has to be inherited for all allocation requests
4998 * from a particular context which has been marked by
4999 * memalloc_no{fs,io}_{save,restore}.
5001 alloc_mask
= current_gfp_context(gfp_mask
);
5002 ac
.spread_dirty_pages
= false;
5005 * Restore the original nodemask if it was potentially replaced with
5006 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
5008 ac
.nodemask
= nodemask
;
5010 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
5013 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
5014 unlikely(__memcg_kmem_charge_page(page
, gfp_mask
, order
) != 0)) {
5015 __free_pages(page
, order
);
5019 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
5023 EXPORT_SYMBOL(__alloc_pages_nodemask
);
5026 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
5027 * address cannot represent highmem pages. Use alloc_pages and then kmap if
5028 * you need to access high mem.
5030 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
5034 page
= alloc_pages(gfp_mask
& ~__GFP_HIGHMEM
, order
);
5037 return (unsigned long) page_address(page
);
5039 EXPORT_SYMBOL(__get_free_pages
);
5041 unsigned long get_zeroed_page(gfp_t gfp_mask
)
5043 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
5045 EXPORT_SYMBOL(get_zeroed_page
);
5047 static inline void free_the_page(struct page
*page
, unsigned int order
)
5049 if (order
== 0) /* Via pcp? */
5050 free_unref_page(page
);
5052 __free_pages_ok(page
, order
, FPI_NONE
);
5056 * __free_pages - Free pages allocated with alloc_pages().
5057 * @page: The page pointer returned from alloc_pages().
5058 * @order: The order of the allocation.
5060 * This function can free multi-page allocations that are not compound
5061 * pages. It does not check that the @order passed in matches that of
5062 * the allocation, so it is easy to leak memory. Freeing more memory
5063 * than was allocated will probably emit a warning.
5065 * If the last reference to this page is speculative, it will be released
5066 * by put_page() which only frees the first page of a non-compound
5067 * allocation. To prevent the remaining pages from being leaked, we free
5068 * the subsequent pages here. If you want to use the page's reference
5069 * count to decide when to free the allocation, you should allocate a
5070 * compound page, and use put_page() instead of __free_pages().
5072 * Context: May be called in interrupt context or while holding a normal
5073 * spinlock, but not in NMI context or while holding a raw spinlock.
5075 void __free_pages(struct page
*page
, unsigned int order
)
5077 if (put_page_testzero(page
))
5078 free_the_page(page
, order
);
5079 else if (!PageHead(page
))
5081 free_the_page(page
+ (1 << order
), order
);
5083 EXPORT_SYMBOL(__free_pages
);
5085 void free_pages(unsigned long addr
, unsigned int order
)
5088 VM_BUG_ON(!virt_addr_valid((void *)addr
));
5089 __free_pages(virt_to_page((void *)addr
), order
);
5093 EXPORT_SYMBOL(free_pages
);
5097 * An arbitrary-length arbitrary-offset area of memory which resides
5098 * within a 0 or higher order page. Multiple fragments within that page
5099 * are individually refcounted, in the page's reference counter.
5101 * The page_frag functions below provide a simple allocation framework for
5102 * page fragments. This is used by the network stack and network device
5103 * drivers to provide a backing region of memory for use as either an
5104 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
5106 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
5109 struct page
*page
= NULL
;
5110 gfp_t gfp
= gfp_mask
;
5112 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5113 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
5115 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
5116 PAGE_FRAG_CACHE_MAX_ORDER
);
5117 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
5119 if (unlikely(!page
))
5120 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
5122 nc
->va
= page
? page_address(page
) : NULL
;
5127 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
5129 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
5131 if (page_ref_sub_and_test(page
, count
))
5132 free_the_page(page
, compound_order(page
));
5134 EXPORT_SYMBOL(__page_frag_cache_drain
);
5136 void *page_frag_alloc(struct page_frag_cache
*nc
,
5137 unsigned int fragsz
, gfp_t gfp_mask
)
5139 unsigned int size
= PAGE_SIZE
;
5143 if (unlikely(!nc
->va
)) {
5145 page
= __page_frag_cache_refill(nc
, gfp_mask
);
5149 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5150 /* if size can vary use size else just use PAGE_SIZE */
5153 /* Even if we own the page, we do not use atomic_set().
5154 * This would break get_page_unless_zero() users.
5156 page_ref_add(page
, PAGE_FRAG_CACHE_MAX_SIZE
);
5158 /* reset page count bias and offset to start of new frag */
5159 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
5160 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5164 offset
= nc
->offset
- fragsz
;
5165 if (unlikely(offset
< 0)) {
5166 page
= virt_to_page(nc
->va
);
5168 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
5171 if (unlikely(nc
->pfmemalloc
)) {
5172 free_the_page(page
, compound_order(page
));
5176 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5177 /* if size can vary use size else just use PAGE_SIZE */
5180 /* OK, page count is 0, we can safely set it */
5181 set_page_count(page
, PAGE_FRAG_CACHE_MAX_SIZE
+ 1);
5183 /* reset page count bias and offset to start of new frag */
5184 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5185 offset
= size
- fragsz
;
5189 nc
->offset
= offset
;
5191 return nc
->va
+ offset
;
5193 EXPORT_SYMBOL(page_frag_alloc
);
5196 * Frees a page fragment allocated out of either a compound or order 0 page.
5198 void page_frag_free(void *addr
)
5200 struct page
*page
= virt_to_head_page(addr
);
5202 if (unlikely(put_page_testzero(page
)))
5203 free_the_page(page
, compound_order(page
));
5205 EXPORT_SYMBOL(page_frag_free
);
5207 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
5211 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
5212 unsigned long used
= addr
+ PAGE_ALIGN(size
);
5214 split_page(virt_to_page((void *)addr
), order
);
5215 while (used
< alloc_end
) {
5220 return (void *)addr
;
5224 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5225 * @size: the number of bytes to allocate
5226 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5228 * This function is similar to alloc_pages(), except that it allocates the
5229 * minimum number of pages to satisfy the request. alloc_pages() can only
5230 * allocate memory in power-of-two pages.
5232 * This function is also limited by MAX_ORDER.
5234 * Memory allocated by this function must be released by free_pages_exact().
5236 * Return: pointer to the allocated area or %NULL in case of error.
5238 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
5240 unsigned int order
= get_order(size
);
5243 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5244 gfp_mask
&= ~__GFP_COMP
;
5246 addr
= __get_free_pages(gfp_mask
, order
);
5247 return make_alloc_exact(addr
, order
, size
);
5249 EXPORT_SYMBOL(alloc_pages_exact
);
5252 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5254 * @nid: the preferred node ID where memory should be allocated
5255 * @size: the number of bytes to allocate
5256 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5258 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5261 * Return: pointer to the allocated area or %NULL in case of error.
5263 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
5265 unsigned int order
= get_order(size
);
5268 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5269 gfp_mask
&= ~__GFP_COMP
;
5271 p
= alloc_pages_node(nid
, gfp_mask
, order
);
5274 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
5278 * free_pages_exact - release memory allocated via alloc_pages_exact()
5279 * @virt: the value returned by alloc_pages_exact.
5280 * @size: size of allocation, same value as passed to alloc_pages_exact().
5282 * Release the memory allocated by a previous call to alloc_pages_exact.
5284 void free_pages_exact(void *virt
, size_t size
)
5286 unsigned long addr
= (unsigned long)virt
;
5287 unsigned long end
= addr
+ PAGE_ALIGN(size
);
5289 while (addr
< end
) {
5294 EXPORT_SYMBOL(free_pages_exact
);
5297 * nr_free_zone_pages - count number of pages beyond high watermark
5298 * @offset: The zone index of the highest zone
5300 * nr_free_zone_pages() counts the number of pages which are beyond the
5301 * high watermark within all zones at or below a given zone index. For each
5302 * zone, the number of pages is calculated as:
5304 * nr_free_zone_pages = managed_pages - high_pages
5306 * Return: number of pages beyond high watermark.
5308 static unsigned long nr_free_zone_pages(int offset
)
5313 /* Just pick one node, since fallback list is circular */
5314 unsigned long sum
= 0;
5316 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
5318 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
5319 unsigned long size
= zone_managed_pages(zone
);
5320 unsigned long high
= high_wmark_pages(zone
);
5329 * nr_free_buffer_pages - count number of pages beyond high watermark
5331 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5332 * watermark within ZONE_DMA and ZONE_NORMAL.
5334 * Return: number of pages beyond high watermark within ZONE_DMA and
5337 unsigned long nr_free_buffer_pages(void)
5339 return nr_free_zone_pages(gfp_zone(GFP_USER
));
5341 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
5343 static inline void show_node(struct zone
*zone
)
5345 if (IS_ENABLED(CONFIG_NUMA
))
5346 printk("Node %d ", zone_to_nid(zone
));
5349 long si_mem_available(void)
5352 unsigned long pagecache
;
5353 unsigned long wmark_low
= 0;
5354 unsigned long pages
[NR_LRU_LISTS
];
5355 unsigned long reclaimable
;
5359 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
5360 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
5363 wmark_low
+= low_wmark_pages(zone
);
5366 * Estimate the amount of memory available for userspace allocations,
5367 * without causing swapping.
5369 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
5372 * Not all the page cache can be freed, otherwise the system will
5373 * start swapping. Assume at least half of the page cache, or the
5374 * low watermark worth of cache, needs to stay.
5376 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
5377 pagecache
-= min(pagecache
/ 2, wmark_low
);
5378 available
+= pagecache
;
5381 * Part of the reclaimable slab and other kernel memory consists of
5382 * items that are in use, and cannot be freed. Cap this estimate at the
5385 reclaimable
= global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
) +
5386 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE
);
5387 available
+= reclaimable
- min(reclaimable
/ 2, wmark_low
);
5393 EXPORT_SYMBOL_GPL(si_mem_available
);
5395 void si_meminfo(struct sysinfo
*val
)
5397 val
->totalram
= totalram_pages();
5398 val
->sharedram
= global_node_page_state(NR_SHMEM
);
5399 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
5400 val
->bufferram
= nr_blockdev_pages();
5401 val
->totalhigh
= totalhigh_pages();
5402 val
->freehigh
= nr_free_highpages();
5403 val
->mem_unit
= PAGE_SIZE
;
5406 EXPORT_SYMBOL(si_meminfo
);
5409 void si_meminfo_node(struct sysinfo
*val
, int nid
)
5411 int zone_type
; /* needs to be signed */
5412 unsigned long managed_pages
= 0;
5413 unsigned long managed_highpages
= 0;
5414 unsigned long free_highpages
= 0;
5415 pg_data_t
*pgdat
= NODE_DATA(nid
);
5417 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
5418 managed_pages
+= zone_managed_pages(&pgdat
->node_zones
[zone_type
]);
5419 val
->totalram
= managed_pages
;
5420 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
5421 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
5422 #ifdef CONFIG_HIGHMEM
5423 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
5424 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5426 if (is_highmem(zone
)) {
5427 managed_highpages
+= zone_managed_pages(zone
);
5428 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
5431 val
->totalhigh
= managed_highpages
;
5432 val
->freehigh
= free_highpages
;
5434 val
->totalhigh
= managed_highpages
;
5435 val
->freehigh
= free_highpages
;
5437 val
->mem_unit
= PAGE_SIZE
;
5442 * Determine whether the node should be displayed or not, depending on whether
5443 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5445 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
5447 if (!(flags
& SHOW_MEM_FILTER_NODES
))
5451 * no node mask - aka implicit memory numa policy. Do not bother with
5452 * the synchronization - read_mems_allowed_begin - because we do not
5453 * have to be precise here.
5456 nodemask
= &cpuset_current_mems_allowed
;
5458 return !node_isset(nid
, *nodemask
);
5461 #define K(x) ((x) << (PAGE_SHIFT-10))
5463 static void show_migration_types(unsigned char type
)
5465 static const char types
[MIGRATE_TYPES
] = {
5466 [MIGRATE_UNMOVABLE
] = 'U',
5467 [MIGRATE_MOVABLE
] = 'M',
5468 [MIGRATE_RECLAIMABLE
] = 'E',
5469 [MIGRATE_HIGHATOMIC
] = 'H',
5471 [MIGRATE_CMA
] = 'C',
5473 #ifdef CONFIG_MEMORY_ISOLATION
5474 [MIGRATE_ISOLATE
] = 'I',
5477 char tmp
[MIGRATE_TYPES
+ 1];
5481 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
5482 if (type
& (1 << i
))
5487 printk(KERN_CONT
"(%s) ", tmp
);
5491 * Show free area list (used inside shift_scroll-lock stuff)
5492 * We also calculate the percentage fragmentation. We do this by counting the
5493 * memory on each free list with the exception of the first item on the list.
5496 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5499 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
5501 unsigned long free_pcp
= 0;
5506 for_each_populated_zone(zone
) {
5507 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5510 for_each_online_cpu(cpu
)
5511 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5514 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5515 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5516 " unevictable:%lu dirty:%lu writeback:%lu\n"
5517 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5518 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5519 " free:%lu free_pcp:%lu free_cma:%lu\n",
5520 global_node_page_state(NR_ACTIVE_ANON
),
5521 global_node_page_state(NR_INACTIVE_ANON
),
5522 global_node_page_state(NR_ISOLATED_ANON
),
5523 global_node_page_state(NR_ACTIVE_FILE
),
5524 global_node_page_state(NR_INACTIVE_FILE
),
5525 global_node_page_state(NR_ISOLATED_FILE
),
5526 global_node_page_state(NR_UNEVICTABLE
),
5527 global_node_page_state(NR_FILE_DIRTY
),
5528 global_node_page_state(NR_WRITEBACK
),
5529 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
),
5530 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B
),
5531 global_node_page_state(NR_FILE_MAPPED
),
5532 global_node_page_state(NR_SHMEM
),
5533 global_node_page_state(NR_PAGETABLE
),
5534 global_zone_page_state(NR_BOUNCE
),
5535 global_zone_page_state(NR_FREE_PAGES
),
5537 global_zone_page_state(NR_FREE_CMA_PAGES
));
5539 for_each_online_pgdat(pgdat
) {
5540 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
5544 " active_anon:%lukB"
5545 " inactive_anon:%lukB"
5546 " active_file:%lukB"
5547 " inactive_file:%lukB"
5548 " unevictable:%lukB"
5549 " isolated(anon):%lukB"
5550 " isolated(file):%lukB"
5555 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5557 " shmem_pmdmapped: %lukB"
5560 " writeback_tmp:%lukB"
5561 " kernel_stack:%lukB"
5562 #ifdef CONFIG_SHADOW_CALL_STACK
5563 " shadow_call_stack:%lukB"
5566 " all_unreclaimable? %s"
5569 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
5570 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
5571 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
5572 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
5573 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
5574 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
5575 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
5576 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
5577 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
5578 K(node_page_state(pgdat
, NR_WRITEBACK
)),
5579 K(node_page_state(pgdat
, NR_SHMEM
)),
5580 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5581 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
5582 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
5584 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
5586 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
5587 node_page_state(pgdat
, NR_KERNEL_STACK_KB
),
5588 #ifdef CONFIG_SHADOW_CALL_STACK
5589 node_page_state(pgdat
, NR_KERNEL_SCS_KB
),
5591 K(node_page_state(pgdat
, NR_PAGETABLE
)),
5592 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
5596 for_each_populated_zone(zone
) {
5599 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5603 for_each_online_cpu(cpu
)
5604 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5613 " reserved_highatomic:%luKB"
5614 " active_anon:%lukB"
5615 " inactive_anon:%lukB"
5616 " active_file:%lukB"
5617 " inactive_file:%lukB"
5618 " unevictable:%lukB"
5619 " writepending:%lukB"
5629 K(zone_page_state(zone
, NR_FREE_PAGES
)),
5630 K(min_wmark_pages(zone
)),
5631 K(low_wmark_pages(zone
)),
5632 K(high_wmark_pages(zone
)),
5633 K(zone
->nr_reserved_highatomic
),
5634 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
5635 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
5636 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
5637 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
5638 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
5639 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
5640 K(zone
->present_pages
),
5641 K(zone_managed_pages(zone
)),
5642 K(zone_page_state(zone
, NR_MLOCK
)),
5643 K(zone_page_state(zone
, NR_BOUNCE
)),
5645 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
5646 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
5647 printk("lowmem_reserve[]:");
5648 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
5649 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
5650 printk(KERN_CONT
"\n");
5653 for_each_populated_zone(zone
) {
5655 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
5656 unsigned char types
[MAX_ORDER
];
5658 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5661 printk(KERN_CONT
"%s: ", zone
->name
);
5663 spin_lock_irqsave(&zone
->lock
, flags
);
5664 for (order
= 0; order
< MAX_ORDER
; order
++) {
5665 struct free_area
*area
= &zone
->free_area
[order
];
5668 nr
[order
] = area
->nr_free
;
5669 total
+= nr
[order
] << order
;
5672 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
5673 if (!free_area_empty(area
, type
))
5674 types
[order
] |= 1 << type
;
5677 spin_unlock_irqrestore(&zone
->lock
, flags
);
5678 for (order
= 0; order
< MAX_ORDER
; order
++) {
5679 printk(KERN_CONT
"%lu*%lukB ",
5680 nr
[order
], K(1UL) << order
);
5682 show_migration_types(types
[order
]);
5684 printk(KERN_CONT
"= %lukB\n", K(total
));
5687 hugetlb_show_meminfo();
5689 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
5691 show_swap_cache_info();
5694 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
5696 zoneref
->zone
= zone
;
5697 zoneref
->zone_idx
= zone_idx(zone
);
5701 * Builds allocation fallback zone lists.
5703 * Add all populated zones of a node to the zonelist.
5705 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
5708 enum zone_type zone_type
= MAX_NR_ZONES
;
5713 zone
= pgdat
->node_zones
+ zone_type
;
5714 if (managed_zone(zone
)) {
5715 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
5716 check_highest_zone(zone_type
);
5718 } while (zone_type
);
5725 static int __parse_numa_zonelist_order(char *s
)
5728 * We used to support different zonlists modes but they turned
5729 * out to be just not useful. Let's keep the warning in place
5730 * if somebody still use the cmd line parameter so that we do
5731 * not fail it silently
5733 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
5734 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
5740 char numa_zonelist_order
[] = "Node";
5743 * sysctl handler for numa_zonelist_order
5745 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
5746 void *buffer
, size_t *length
, loff_t
*ppos
)
5749 return __parse_numa_zonelist_order(buffer
);
5750 return proc_dostring(table
, write
, buffer
, length
, ppos
);
5754 #define MAX_NODE_LOAD (nr_online_nodes)
5755 static int node_load
[MAX_NUMNODES
];
5758 * find_next_best_node - find the next node that should appear in a given node's fallback list
5759 * @node: node whose fallback list we're appending
5760 * @used_node_mask: nodemask_t of already used nodes
5762 * We use a number of factors to determine which is the next node that should
5763 * appear on a given node's fallback list. The node should not have appeared
5764 * already in @node's fallback list, and it should be the next closest node
5765 * according to the distance array (which contains arbitrary distance values
5766 * from each node to each node in the system), and should also prefer nodes
5767 * with no CPUs, since presumably they'll have very little allocation pressure
5768 * on them otherwise.
5770 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5772 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
5775 int min_val
= INT_MAX
;
5776 int best_node
= NUMA_NO_NODE
;
5778 /* Use the local node if we haven't already */
5779 if (!node_isset(node
, *used_node_mask
)) {
5780 node_set(node
, *used_node_mask
);
5784 for_each_node_state(n
, N_MEMORY
) {
5786 /* Don't want a node to appear more than once */
5787 if (node_isset(n
, *used_node_mask
))
5790 /* Use the distance array to find the distance */
5791 val
= node_distance(node
, n
);
5793 /* Penalize nodes under us ("prefer the next node") */
5796 /* Give preference to headless and unused nodes */
5797 if (!cpumask_empty(cpumask_of_node(n
)))
5798 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
5800 /* Slight preference for less loaded node */
5801 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
5802 val
+= node_load
[n
];
5804 if (val
< min_val
) {
5811 node_set(best_node
, *used_node_mask
);
5818 * Build zonelists ordered by node and zones within node.
5819 * This results in maximum locality--normal zone overflows into local
5820 * DMA zone, if any--but risks exhausting DMA zone.
5822 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5825 struct zoneref
*zonerefs
;
5828 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5830 for (i
= 0; i
< nr_nodes
; i
++) {
5833 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5835 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5836 zonerefs
+= nr_zones
;
5838 zonerefs
->zone
= NULL
;
5839 zonerefs
->zone_idx
= 0;
5843 * Build gfp_thisnode zonelists
5845 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5847 struct zoneref
*zonerefs
;
5850 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5851 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5852 zonerefs
+= nr_zones
;
5853 zonerefs
->zone
= NULL
;
5854 zonerefs
->zone_idx
= 0;
5858 * Build zonelists ordered by zone and nodes within zones.
5859 * This results in conserving DMA zone[s] until all Normal memory is
5860 * exhausted, but results in overflowing to remote node while memory
5861 * may still exist in local DMA zone.
5864 static void build_zonelists(pg_data_t
*pgdat
)
5866 static int node_order
[MAX_NUMNODES
];
5867 int node
, load
, nr_nodes
= 0;
5868 nodemask_t used_mask
= NODE_MASK_NONE
;
5869 int local_node
, prev_node
;
5871 /* NUMA-aware ordering of nodes */
5872 local_node
= pgdat
->node_id
;
5873 load
= nr_online_nodes
;
5874 prev_node
= local_node
;
5876 memset(node_order
, 0, sizeof(node_order
));
5877 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5879 * We don't want to pressure a particular node.
5880 * So adding penalty to the first node in same
5881 * distance group to make it round-robin.
5883 if (node_distance(local_node
, node
) !=
5884 node_distance(local_node
, prev_node
))
5885 node_load
[node
] = load
;
5887 node_order
[nr_nodes
++] = node
;
5892 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5893 build_thisnode_zonelists(pgdat
);
5896 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5898 * Return node id of node used for "local" allocations.
5899 * I.e., first node id of first zone in arg node's generic zonelist.
5900 * Used for initializing percpu 'numa_mem', which is used primarily
5901 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5903 int local_memory_node(int node
)
5907 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5908 gfp_zone(GFP_KERNEL
),
5910 return zone_to_nid(z
->zone
);
5914 static void setup_min_unmapped_ratio(void);
5915 static void setup_min_slab_ratio(void);
5916 #else /* CONFIG_NUMA */
5918 static void build_zonelists(pg_data_t
*pgdat
)
5920 int node
, local_node
;
5921 struct zoneref
*zonerefs
;
5924 local_node
= pgdat
->node_id
;
5926 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5927 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5928 zonerefs
+= nr_zones
;
5931 * Now we build the zonelist so that it contains the zones
5932 * of all the other nodes.
5933 * We don't want to pressure a particular node, so when
5934 * building the zones for node N, we make sure that the
5935 * zones coming right after the local ones are those from
5936 * node N+1 (modulo N)
5938 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5939 if (!node_online(node
))
5941 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5942 zonerefs
+= nr_zones
;
5944 for (node
= 0; node
< local_node
; node
++) {
5945 if (!node_online(node
))
5947 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5948 zonerefs
+= nr_zones
;
5951 zonerefs
->zone
= NULL
;
5952 zonerefs
->zone_idx
= 0;
5955 #endif /* CONFIG_NUMA */
5958 * Boot pageset table. One per cpu which is going to be used for all
5959 * zones and all nodes. The parameters will be set in such a way
5960 * that an item put on a list will immediately be handed over to
5961 * the buddy list. This is safe since pageset manipulation is done
5962 * with interrupts disabled.
5964 * The boot_pagesets must be kept even after bootup is complete for
5965 * unused processors and/or zones. They do play a role for bootstrapping
5966 * hotplugged processors.
5968 * zoneinfo_show() and maybe other functions do
5969 * not check if the processor is online before following the pageset pointer.
5970 * Other parts of the kernel may not check if the zone is available.
5972 static void pageset_init(struct per_cpu_pageset
*p
);
5973 /* These effectively disable the pcplists in the boot pageset completely */
5974 #define BOOT_PAGESET_HIGH 0
5975 #define BOOT_PAGESET_BATCH 1
5976 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5977 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5979 static void __build_all_zonelists(void *data
)
5982 int __maybe_unused cpu
;
5983 pg_data_t
*self
= data
;
5984 static DEFINE_SPINLOCK(lock
);
5989 memset(node_load
, 0, sizeof(node_load
));
5993 * This node is hotadded and no memory is yet present. So just
5994 * building zonelists is fine - no need to touch other nodes.
5996 if (self
&& !node_online(self
->node_id
)) {
5997 build_zonelists(self
);
5999 for_each_online_node(nid
) {
6000 pg_data_t
*pgdat
= NODE_DATA(nid
);
6002 build_zonelists(pgdat
);
6005 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
6007 * We now know the "local memory node" for each node--
6008 * i.e., the node of the first zone in the generic zonelist.
6009 * Set up numa_mem percpu variable for on-line cpus. During
6010 * boot, only the boot cpu should be on-line; we'll init the
6011 * secondary cpus' numa_mem as they come on-line. During
6012 * node/memory hotplug, we'll fixup all on-line cpus.
6014 for_each_online_cpu(cpu
)
6015 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
6022 static noinline
void __init
6023 build_all_zonelists_init(void)
6027 __build_all_zonelists(NULL
);
6030 * Initialize the boot_pagesets that are going to be used
6031 * for bootstrapping processors. The real pagesets for
6032 * each zone will be allocated later when the per cpu
6033 * allocator is available.
6035 * boot_pagesets are used also for bootstrapping offline
6036 * cpus if the system is already booted because the pagesets
6037 * are needed to initialize allocators on a specific cpu too.
6038 * F.e. the percpu allocator needs the page allocator which
6039 * needs the percpu allocator in order to allocate its pagesets
6040 * (a chicken-egg dilemma).
6042 for_each_possible_cpu(cpu
)
6043 pageset_init(&per_cpu(boot_pageset
, cpu
));
6045 mminit_verify_zonelist();
6046 cpuset_init_current_mems_allowed();
6050 * unless system_state == SYSTEM_BOOTING.
6052 * __ref due to call of __init annotated helper build_all_zonelists_init
6053 * [protected by SYSTEM_BOOTING].
6055 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
6057 unsigned long vm_total_pages
;
6059 if (system_state
== SYSTEM_BOOTING
) {
6060 build_all_zonelists_init();
6062 __build_all_zonelists(pgdat
);
6063 /* cpuset refresh routine should be here */
6065 /* Get the number of free pages beyond high watermark in all zones. */
6066 vm_total_pages
= nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
6068 * Disable grouping by mobility if the number of pages in the
6069 * system is too low to allow the mechanism to work. It would be
6070 * more accurate, but expensive to check per-zone. This check is
6071 * made on memory-hotadd so a system can start with mobility
6072 * disabled and enable it later
6074 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
6075 page_group_by_mobility_disabled
= 1;
6077 page_group_by_mobility_disabled
= 0;
6079 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
6081 page_group_by_mobility_disabled
? "off" : "on",
6084 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
6088 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
6089 static bool __meminit
6090 overlap_memmap_init(unsigned long zone
, unsigned long *pfn
)
6092 static struct memblock_region
*r
;
6094 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
6095 if (!r
|| *pfn
>= memblock_region_memory_end_pfn(r
)) {
6096 for_each_mem_region(r
) {
6097 if (*pfn
< memblock_region_memory_end_pfn(r
))
6101 if (*pfn
>= memblock_region_memory_base_pfn(r
) &&
6102 memblock_is_mirror(r
)) {
6103 *pfn
= memblock_region_memory_end_pfn(r
);
6111 * Initially all pages are reserved - free ones are freed
6112 * up by memblock_free_all() once the early boot process is
6113 * done. Non-atomic initialization, single-pass.
6115 * All aligned pageblocks are initialized to the specified migratetype
6116 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related
6117 * zone stats (e.g., nr_isolate_pageblock) are touched.
6119 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
6120 unsigned long start_pfn
, unsigned long zone_end_pfn
,
6121 enum meminit_context context
,
6122 struct vmem_altmap
*altmap
, int migratetype
)
6124 unsigned long pfn
, end_pfn
= start_pfn
+ size
;
6127 if (highest_memmap_pfn
< end_pfn
- 1)
6128 highest_memmap_pfn
= end_pfn
- 1;
6130 #ifdef CONFIG_ZONE_DEVICE
6132 * Honor reservation requested by the driver for this ZONE_DEVICE
6133 * memory. We limit the total number of pages to initialize to just
6134 * those that might contain the memory mapping. We will defer the
6135 * ZONE_DEVICE page initialization until after we have released
6138 if (zone
== ZONE_DEVICE
) {
6142 if (start_pfn
== altmap
->base_pfn
)
6143 start_pfn
+= altmap
->reserve
;
6144 end_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6148 for (pfn
= start_pfn
; pfn
< end_pfn
; ) {
6150 * There can be holes in boot-time mem_map[]s handed to this
6151 * function. They do not exist on hotplugged memory.
6153 if (context
== MEMINIT_EARLY
) {
6154 if (overlap_memmap_init(zone
, &pfn
))
6156 if (defer_init(nid
, pfn
, zone_end_pfn
))
6160 page
= pfn_to_page(pfn
);
6161 __init_single_page(page
, pfn
, zone
, nid
);
6162 if (context
== MEMINIT_HOTPLUG
)
6163 __SetPageReserved(page
);
6166 * Usually, we want to mark the pageblock MIGRATE_MOVABLE,
6167 * such that unmovable allocations won't be scattered all
6168 * over the place during system boot.
6170 if (IS_ALIGNED(pfn
, pageblock_nr_pages
)) {
6171 set_pageblock_migratetype(page
, migratetype
);
6178 #ifdef CONFIG_ZONE_DEVICE
6179 void __ref
memmap_init_zone_device(struct zone
*zone
,
6180 unsigned long start_pfn
,
6181 unsigned long nr_pages
,
6182 struct dev_pagemap
*pgmap
)
6184 unsigned long pfn
, end_pfn
= start_pfn
+ nr_pages
;
6185 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6186 struct vmem_altmap
*altmap
= pgmap_altmap(pgmap
);
6187 unsigned long zone_idx
= zone_idx(zone
);
6188 unsigned long start
= jiffies
;
6189 int nid
= pgdat
->node_id
;
6191 if (WARN_ON_ONCE(!pgmap
|| zone_idx(zone
) != ZONE_DEVICE
))
6195 * The call to memmap_init_zone should have already taken care
6196 * of the pages reserved for the memmap, so we can just jump to
6197 * the end of that region and start processing the device pages.
6200 start_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6201 nr_pages
= end_pfn
- start_pfn
;
6204 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
6205 struct page
*page
= pfn_to_page(pfn
);
6207 __init_single_page(page
, pfn
, zone_idx
, nid
);
6210 * Mark page reserved as it will need to wait for onlining
6211 * phase for it to be fully associated with a zone.
6213 * We can use the non-atomic __set_bit operation for setting
6214 * the flag as we are still initializing the pages.
6216 __SetPageReserved(page
);
6219 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6220 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6221 * ever freed or placed on a driver-private list.
6223 page
->pgmap
= pgmap
;
6224 page
->zone_device_data
= NULL
;
6227 * Mark the block movable so that blocks are reserved for
6228 * movable at startup. This will force kernel allocations
6229 * to reserve their blocks rather than leaking throughout
6230 * the address space during boot when many long-lived
6231 * kernel allocations are made.
6233 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6234 * because this is done early in section_activate()
6236 if (IS_ALIGNED(pfn
, pageblock_nr_pages
)) {
6237 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
6242 pr_info("%s initialised %lu pages in %ums\n", __func__
,
6243 nr_pages
, jiffies_to_msecs(jiffies
- start
));
6247 static void __meminit
zone_init_free_lists(struct zone
*zone
)
6249 unsigned int order
, t
;
6250 for_each_migratetype_order(order
, t
) {
6251 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
6252 zone
->free_area
[order
].nr_free
= 0;
6256 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
6258 * Only struct pages that correspond to ranges defined by memblock.memory
6259 * are zeroed and initialized by going through __init_single_page() during
6260 * memmap_init_zone().
6262 * But, there could be struct pages that correspond to holes in
6263 * memblock.memory. This can happen because of the following reasons:
6264 * - physical memory bank size is not necessarily the exact multiple of the
6265 * arbitrary section size
6266 * - early reserved memory may not be listed in memblock.memory
6267 * - memory layouts defined with memmap= kernel parameter may not align
6268 * nicely with memmap sections
6270 * Explicitly initialize those struct pages so that:
6271 * - PG_Reserved is set
6272 * - zone and node links point to zone and node that span the page if the
6273 * hole is in the middle of a zone
6274 * - zone and node links point to adjacent zone/node if the hole falls on
6275 * the zone boundary; the pages in such holes will be prepended to the
6276 * zone/node above the hole except for the trailing pages in the last
6277 * section that will be appended to the zone/node below.
6279 static u64 __meminit
init_unavailable_range(unsigned long spfn
,
6286 for (pfn
= spfn
; pfn
< epfn
; pfn
++) {
6287 if (!pfn_valid(ALIGN_DOWN(pfn
, pageblock_nr_pages
))) {
6288 pfn
= ALIGN_DOWN(pfn
, pageblock_nr_pages
)
6289 + pageblock_nr_pages
- 1;
6292 __init_single_page(pfn_to_page(pfn
), pfn
, zone
, node
);
6293 __SetPageReserved(pfn_to_page(pfn
));
6300 static inline u64
init_unavailable_range(unsigned long spfn
, unsigned long epfn
,
6307 void __meminit __weak
memmap_init(unsigned long size
, int nid
,
6309 unsigned long range_start_pfn
)
6311 static unsigned long hole_pfn
;
6312 unsigned long start_pfn
, end_pfn
;
6313 unsigned long range_end_pfn
= range_start_pfn
+ size
;
6317 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6318 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6319 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6321 if (end_pfn
> start_pfn
) {
6322 size
= end_pfn
- start_pfn
;
6323 memmap_init_zone(size
, nid
, zone
, start_pfn
, range_end_pfn
,
6324 MEMINIT_EARLY
, NULL
, MIGRATE_MOVABLE
);
6327 if (hole_pfn
< start_pfn
)
6328 pgcnt
+= init_unavailable_range(hole_pfn
, start_pfn
,
6333 #ifdef CONFIG_SPARSEMEM
6335 * Initialize the hole in the range [zone_end_pfn, section_end].
6336 * If zone boundary falls in the middle of a section, this hole
6337 * will be re-initialized during the call to this function for the
6340 end_pfn
= round_up(range_end_pfn
, PAGES_PER_SECTION
);
6341 if (hole_pfn
< end_pfn
)
6342 pgcnt
+= init_unavailable_range(hole_pfn
, end_pfn
,
6347 pr_info(" %s zone: %llu pages in unavailable ranges\n",
6348 zone_names
[zone
], pgcnt
);
6351 static int zone_batchsize(struct zone
*zone
)
6357 * The per-cpu-pages pools are set to around 1000th of the
6360 batch
= zone_managed_pages(zone
) / 1024;
6361 /* But no more than a meg. */
6362 if (batch
* PAGE_SIZE
> 1024 * 1024)
6363 batch
= (1024 * 1024) / PAGE_SIZE
;
6364 batch
/= 4; /* We effectively *= 4 below */
6369 * Clamp the batch to a 2^n - 1 value. Having a power
6370 * of 2 value was found to be more likely to have
6371 * suboptimal cache aliasing properties in some cases.
6373 * For example if 2 tasks are alternately allocating
6374 * batches of pages, one task can end up with a lot
6375 * of pages of one half of the possible page colors
6376 * and the other with pages of the other colors.
6378 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
6383 /* The deferral and batching of frees should be suppressed under NOMMU
6386 * The problem is that NOMMU needs to be able to allocate large chunks
6387 * of contiguous memory as there's no hardware page translation to
6388 * assemble apparent contiguous memory from discontiguous pages.
6390 * Queueing large contiguous runs of pages for batching, however,
6391 * causes the pages to actually be freed in smaller chunks. As there
6392 * can be a significant delay between the individual batches being
6393 * recycled, this leads to the once large chunks of space being
6394 * fragmented and becoming unavailable for high-order allocations.
6401 * pcp->high and pcp->batch values are related and generally batch is lower
6402 * than high. They are also related to pcp->count such that count is lower
6403 * than high, and as soon as it reaches high, the pcplist is flushed.
6405 * However, guaranteeing these relations at all times would require e.g. write
6406 * barriers here but also careful usage of read barriers at the read side, and
6407 * thus be prone to error and bad for performance. Thus the update only prevents
6408 * store tearing. Any new users of pcp->batch and pcp->high should ensure they
6409 * can cope with those fields changing asynchronously, and fully trust only the
6410 * pcp->count field on the local CPU with interrupts disabled.
6412 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6413 * outside of boot time (or some other assurance that no concurrent updaters
6416 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
6417 unsigned long batch
)
6419 WRITE_ONCE(pcp
->batch
, batch
);
6420 WRITE_ONCE(pcp
->high
, high
);
6423 static void pageset_init(struct per_cpu_pageset
*p
)
6425 struct per_cpu_pages
*pcp
;
6428 memset(p
, 0, sizeof(*p
));
6431 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
6432 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
6435 * Set batch and high values safe for a boot pageset. A true percpu
6436 * pageset's initialization will update them subsequently. Here we don't
6437 * need to be as careful as pageset_update() as nobody can access the
6440 pcp
->high
= BOOT_PAGESET_HIGH
;
6441 pcp
->batch
= BOOT_PAGESET_BATCH
;
6444 static void __zone_set_pageset_high_and_batch(struct zone
*zone
, unsigned long high
,
6445 unsigned long batch
)
6447 struct per_cpu_pageset
*p
;
6450 for_each_possible_cpu(cpu
) {
6451 p
= per_cpu_ptr(zone
->pageset
, cpu
);
6452 pageset_update(&p
->pcp
, high
, batch
);
6457 * Calculate and set new high and batch values for all per-cpu pagesets of a
6458 * zone, based on the zone's size and the percpu_pagelist_fraction sysctl.
6460 static void zone_set_pageset_high_and_batch(struct zone
*zone
)
6462 unsigned long new_high
, new_batch
;
6464 if (percpu_pagelist_fraction
) {
6465 new_high
= zone_managed_pages(zone
) / percpu_pagelist_fraction
;
6466 new_batch
= max(1UL, new_high
/ 4);
6467 if ((new_high
/ 4) > (PAGE_SHIFT
* 8))
6468 new_batch
= PAGE_SHIFT
* 8;
6470 new_batch
= zone_batchsize(zone
);
6471 new_high
= 6 * new_batch
;
6472 new_batch
= max(1UL, 1 * new_batch
);
6475 if (zone
->pageset_high
== new_high
&&
6476 zone
->pageset_batch
== new_batch
)
6479 zone
->pageset_high
= new_high
;
6480 zone
->pageset_batch
= new_batch
;
6482 __zone_set_pageset_high_and_batch(zone
, new_high
, new_batch
);
6485 void __meminit
setup_zone_pageset(struct zone
*zone
)
6487 struct per_cpu_pageset
*p
;
6490 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
6491 for_each_possible_cpu(cpu
) {
6492 p
= per_cpu_ptr(zone
->pageset
, cpu
);
6496 zone_set_pageset_high_and_batch(zone
);
6500 * Allocate per cpu pagesets and initialize them.
6501 * Before this call only boot pagesets were available.
6503 void __init
setup_per_cpu_pageset(void)
6505 struct pglist_data
*pgdat
;
6507 int __maybe_unused cpu
;
6509 for_each_populated_zone(zone
)
6510 setup_zone_pageset(zone
);
6514 * Unpopulated zones continue using the boot pagesets.
6515 * The numa stats for these pagesets need to be reset.
6516 * Otherwise, they will end up skewing the stats of
6517 * the nodes these zones are associated with.
6519 for_each_possible_cpu(cpu
) {
6520 struct per_cpu_pageset
*pcp
= &per_cpu(boot_pageset
, cpu
);
6521 memset(pcp
->vm_numa_stat_diff
, 0,
6522 sizeof(pcp
->vm_numa_stat_diff
));
6526 for_each_online_pgdat(pgdat
)
6527 pgdat
->per_cpu_nodestats
=
6528 alloc_percpu(struct per_cpu_nodestat
);
6531 static __meminit
void zone_pcp_init(struct zone
*zone
)
6534 * per cpu subsystem is not up at this point. The following code
6535 * relies on the ability of the linker to provide the
6536 * offset of a (static) per cpu variable into the per cpu area.
6538 zone
->pageset
= &boot_pageset
;
6539 zone
->pageset_high
= BOOT_PAGESET_HIGH
;
6540 zone
->pageset_batch
= BOOT_PAGESET_BATCH
;
6542 if (populated_zone(zone
))
6543 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
6544 zone
->name
, zone
->present_pages
,
6545 zone_batchsize(zone
));
6548 void __meminit
init_currently_empty_zone(struct zone
*zone
,
6549 unsigned long zone_start_pfn
,
6552 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6553 int zone_idx
= zone_idx(zone
) + 1;
6555 if (zone_idx
> pgdat
->nr_zones
)
6556 pgdat
->nr_zones
= zone_idx
;
6558 zone
->zone_start_pfn
= zone_start_pfn
;
6560 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
6561 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6563 (unsigned long)zone_idx(zone
),
6564 zone_start_pfn
, (zone_start_pfn
+ size
));
6566 zone_init_free_lists(zone
);
6567 zone
->initialized
= 1;
6571 * get_pfn_range_for_nid - Return the start and end page frames for a node
6572 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6573 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6574 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6576 * It returns the start and end page frame of a node based on information
6577 * provided by memblock_set_node(). If called for a node
6578 * with no available memory, a warning is printed and the start and end
6581 void __init
get_pfn_range_for_nid(unsigned int nid
,
6582 unsigned long *start_pfn
, unsigned long *end_pfn
)
6584 unsigned long this_start_pfn
, this_end_pfn
;
6590 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
6591 *start_pfn
= min(*start_pfn
, this_start_pfn
);
6592 *end_pfn
= max(*end_pfn
, this_end_pfn
);
6595 if (*start_pfn
== -1UL)
6600 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6601 * assumption is made that zones within a node are ordered in monotonic
6602 * increasing memory addresses so that the "highest" populated zone is used
6604 static void __init
find_usable_zone_for_movable(void)
6607 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
6608 if (zone_index
== ZONE_MOVABLE
)
6611 if (arch_zone_highest_possible_pfn
[zone_index
] >
6612 arch_zone_lowest_possible_pfn
[zone_index
])
6616 VM_BUG_ON(zone_index
== -1);
6617 movable_zone
= zone_index
;
6621 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6622 * because it is sized independent of architecture. Unlike the other zones,
6623 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6624 * in each node depending on the size of each node and how evenly kernelcore
6625 * is distributed. This helper function adjusts the zone ranges
6626 * provided by the architecture for a given node by using the end of the
6627 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6628 * zones within a node are in order of monotonic increases memory addresses
6630 static void __init
adjust_zone_range_for_zone_movable(int nid
,
6631 unsigned long zone_type
,
6632 unsigned long node_start_pfn
,
6633 unsigned long node_end_pfn
,
6634 unsigned long *zone_start_pfn
,
6635 unsigned long *zone_end_pfn
)
6637 /* Only adjust if ZONE_MOVABLE is on this node */
6638 if (zone_movable_pfn
[nid
]) {
6639 /* Size ZONE_MOVABLE */
6640 if (zone_type
== ZONE_MOVABLE
) {
6641 *zone_start_pfn
= zone_movable_pfn
[nid
];
6642 *zone_end_pfn
= min(node_end_pfn
,
6643 arch_zone_highest_possible_pfn
[movable_zone
]);
6645 /* Adjust for ZONE_MOVABLE starting within this range */
6646 } else if (!mirrored_kernelcore
&&
6647 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
6648 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
6649 *zone_end_pfn
= zone_movable_pfn
[nid
];
6651 /* Check if this whole range is within ZONE_MOVABLE */
6652 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
6653 *zone_start_pfn
= *zone_end_pfn
;
6658 * Return the number of pages a zone spans in a node, including holes
6659 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6661 static unsigned long __init
zone_spanned_pages_in_node(int nid
,
6662 unsigned long zone_type
,
6663 unsigned long node_start_pfn
,
6664 unsigned long node_end_pfn
,
6665 unsigned long *zone_start_pfn
,
6666 unsigned long *zone_end_pfn
)
6668 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6669 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6670 /* When hotadd a new node from cpu_up(), the node should be empty */
6671 if (!node_start_pfn
&& !node_end_pfn
)
6674 /* Get the start and end of the zone */
6675 *zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6676 *zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6677 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6678 node_start_pfn
, node_end_pfn
,
6679 zone_start_pfn
, zone_end_pfn
);
6681 /* Check that this node has pages within the zone's required range */
6682 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
6685 /* Move the zone boundaries inside the node if necessary */
6686 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
6687 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
6689 /* Return the spanned pages */
6690 return *zone_end_pfn
- *zone_start_pfn
;
6694 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6695 * then all holes in the requested range will be accounted for.
6697 unsigned long __init
__absent_pages_in_range(int nid
,
6698 unsigned long range_start_pfn
,
6699 unsigned long range_end_pfn
)
6701 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
6702 unsigned long start_pfn
, end_pfn
;
6705 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6706 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6707 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6708 nr_absent
-= end_pfn
- start_pfn
;
6714 * absent_pages_in_range - Return number of page frames in holes within a range
6715 * @start_pfn: The start PFN to start searching for holes
6716 * @end_pfn: The end PFN to stop searching for holes
6718 * Return: the number of pages frames in memory holes within a range.
6720 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
6721 unsigned long end_pfn
)
6723 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
6726 /* Return the number of page frames in holes in a zone on a node */
6727 static unsigned long __init
zone_absent_pages_in_node(int nid
,
6728 unsigned long zone_type
,
6729 unsigned long node_start_pfn
,
6730 unsigned long node_end_pfn
)
6732 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6733 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6734 unsigned long zone_start_pfn
, zone_end_pfn
;
6735 unsigned long nr_absent
;
6737 /* When hotadd a new node from cpu_up(), the node should be empty */
6738 if (!node_start_pfn
&& !node_end_pfn
)
6741 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6742 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6744 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6745 node_start_pfn
, node_end_pfn
,
6746 &zone_start_pfn
, &zone_end_pfn
);
6747 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
6750 * ZONE_MOVABLE handling.
6751 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6754 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
6755 unsigned long start_pfn
, end_pfn
;
6756 struct memblock_region
*r
;
6758 for_each_mem_region(r
) {
6759 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
6760 zone_start_pfn
, zone_end_pfn
);
6761 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
6762 zone_start_pfn
, zone_end_pfn
);
6764 if (zone_type
== ZONE_MOVABLE
&&
6765 memblock_is_mirror(r
))
6766 nr_absent
+= end_pfn
- start_pfn
;
6768 if (zone_type
== ZONE_NORMAL
&&
6769 !memblock_is_mirror(r
))
6770 nr_absent
+= end_pfn
- start_pfn
;
6777 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
6778 unsigned long node_start_pfn
,
6779 unsigned long node_end_pfn
)
6781 unsigned long realtotalpages
= 0, totalpages
= 0;
6784 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6785 struct zone
*zone
= pgdat
->node_zones
+ i
;
6786 unsigned long zone_start_pfn
, zone_end_pfn
;
6787 unsigned long spanned
, absent
;
6788 unsigned long size
, real_size
;
6790 spanned
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
6795 absent
= zone_absent_pages_in_node(pgdat
->node_id
, i
,
6800 real_size
= size
- absent
;
6803 zone
->zone_start_pfn
= zone_start_pfn
;
6805 zone
->zone_start_pfn
= 0;
6806 zone
->spanned_pages
= size
;
6807 zone
->present_pages
= real_size
;
6810 realtotalpages
+= real_size
;
6813 pgdat
->node_spanned_pages
= totalpages
;
6814 pgdat
->node_present_pages
= realtotalpages
;
6815 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
6819 #ifndef CONFIG_SPARSEMEM
6821 * Calculate the size of the zone->blockflags rounded to an unsigned long
6822 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6823 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6824 * round what is now in bits to nearest long in bits, then return it in
6827 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
6829 unsigned long usemapsize
;
6831 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
6832 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
6833 usemapsize
= usemapsize
>> pageblock_order
;
6834 usemapsize
*= NR_PAGEBLOCK_BITS
;
6835 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
6837 return usemapsize
/ 8;
6840 static void __ref
setup_usemap(struct pglist_data
*pgdat
,
6842 unsigned long zone_start_pfn
,
6843 unsigned long zonesize
)
6845 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
6846 zone
->pageblock_flags
= NULL
;
6848 zone
->pageblock_flags
=
6849 memblock_alloc_node(usemapsize
, SMP_CACHE_BYTES
,
6851 if (!zone
->pageblock_flags
)
6852 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6853 usemapsize
, zone
->name
, pgdat
->node_id
);
6857 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
6858 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
6859 #endif /* CONFIG_SPARSEMEM */
6861 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6863 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6864 void __init
set_pageblock_order(void)
6868 /* Check that pageblock_nr_pages has not already been setup */
6869 if (pageblock_order
)
6872 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6873 order
= HUGETLB_PAGE_ORDER
;
6875 order
= MAX_ORDER
- 1;
6878 * Assume the largest contiguous order of interest is a huge page.
6879 * This value may be variable depending on boot parameters on IA64 and
6882 pageblock_order
= order
;
6884 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6887 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6888 * is unused as pageblock_order is set at compile-time. See
6889 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6892 void __init
set_pageblock_order(void)
6896 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6898 static unsigned long __init
calc_memmap_size(unsigned long spanned_pages
,
6899 unsigned long present_pages
)
6901 unsigned long pages
= spanned_pages
;
6904 * Provide a more accurate estimation if there are holes within
6905 * the zone and SPARSEMEM is in use. If there are holes within the
6906 * zone, each populated memory region may cost us one or two extra
6907 * memmap pages due to alignment because memmap pages for each
6908 * populated regions may not be naturally aligned on page boundary.
6909 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6911 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6912 IS_ENABLED(CONFIG_SPARSEMEM
))
6913 pages
= present_pages
;
6915 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6918 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6919 static void pgdat_init_split_queue(struct pglist_data
*pgdat
)
6921 struct deferred_split
*ds_queue
= &pgdat
->deferred_split_queue
;
6923 spin_lock_init(&ds_queue
->split_queue_lock
);
6924 INIT_LIST_HEAD(&ds_queue
->split_queue
);
6925 ds_queue
->split_queue_len
= 0;
6928 static void pgdat_init_split_queue(struct pglist_data
*pgdat
) {}
6931 #ifdef CONFIG_COMPACTION
6932 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
)
6934 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6937 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
) {}
6940 static void __meminit
pgdat_init_internals(struct pglist_data
*pgdat
)
6942 pgdat_resize_init(pgdat
);
6944 pgdat_init_split_queue(pgdat
);
6945 pgdat_init_kcompactd(pgdat
);
6947 init_waitqueue_head(&pgdat
->kswapd_wait
);
6948 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6950 pgdat_page_ext_init(pgdat
);
6951 lruvec_init(&pgdat
->__lruvec
);
6954 static void __meminit
zone_init_internals(struct zone
*zone
, enum zone_type idx
, int nid
,
6955 unsigned long remaining_pages
)
6957 atomic_long_set(&zone
->managed_pages
, remaining_pages
);
6958 zone_set_nid(zone
, nid
);
6959 zone
->name
= zone_names
[idx
];
6960 zone
->zone_pgdat
= NODE_DATA(nid
);
6961 spin_lock_init(&zone
->lock
);
6962 zone_seqlock_init(zone
);
6963 zone_pcp_init(zone
);
6967 * Set up the zone data structures
6968 * - init pgdat internals
6969 * - init all zones belonging to this node
6971 * NOTE: this function is only called during memory hotplug
6973 #ifdef CONFIG_MEMORY_HOTPLUG
6974 void __ref
free_area_init_core_hotplug(int nid
)
6977 pg_data_t
*pgdat
= NODE_DATA(nid
);
6979 pgdat_init_internals(pgdat
);
6980 for (z
= 0; z
< MAX_NR_ZONES
; z
++)
6981 zone_init_internals(&pgdat
->node_zones
[z
], z
, nid
, 0);
6986 * Set up the zone data structures:
6987 * - mark all pages reserved
6988 * - mark all memory queues empty
6989 * - clear the memory bitmaps
6991 * NOTE: pgdat should get zeroed by caller.
6992 * NOTE: this function is only called during early init.
6994 static void __init
free_area_init_core(struct pglist_data
*pgdat
)
6997 int nid
= pgdat
->node_id
;
6999 pgdat_init_internals(pgdat
);
7000 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
7002 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
7003 struct zone
*zone
= pgdat
->node_zones
+ j
;
7004 unsigned long size
, freesize
, memmap_pages
;
7005 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
7007 size
= zone
->spanned_pages
;
7008 freesize
= zone
->present_pages
;
7011 * Adjust freesize so that it accounts for how much memory
7012 * is used by this zone for memmap. This affects the watermark
7013 * and per-cpu initialisations
7015 memmap_pages
= calc_memmap_size(size
, freesize
);
7016 if (!is_highmem_idx(j
)) {
7017 if (freesize
>= memmap_pages
) {
7018 freesize
-= memmap_pages
;
7021 " %s zone: %lu pages used for memmap\n",
7022 zone_names
[j
], memmap_pages
);
7024 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
7025 zone_names
[j
], memmap_pages
, freesize
);
7028 /* Account for reserved pages */
7029 if (j
== 0 && freesize
> dma_reserve
) {
7030 freesize
-= dma_reserve
;
7031 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
7032 zone_names
[0], dma_reserve
);
7035 if (!is_highmem_idx(j
))
7036 nr_kernel_pages
+= freesize
;
7037 /* Charge for highmem memmap if there are enough kernel pages */
7038 else if (nr_kernel_pages
> memmap_pages
* 2)
7039 nr_kernel_pages
-= memmap_pages
;
7040 nr_all_pages
+= freesize
;
7043 * Set an approximate value for lowmem here, it will be adjusted
7044 * when the bootmem allocator frees pages into the buddy system.
7045 * And all highmem pages will be managed by the buddy system.
7047 zone_init_internals(zone
, j
, nid
, freesize
);
7052 set_pageblock_order();
7053 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
7054 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
7055 memmap_init(size
, nid
, j
, zone_start_pfn
);
7059 #ifdef CONFIG_FLAT_NODE_MEM_MAP
7060 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
7062 unsigned long __maybe_unused start
= 0;
7063 unsigned long __maybe_unused offset
= 0;
7065 /* Skip empty nodes */
7066 if (!pgdat
->node_spanned_pages
)
7069 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
7070 offset
= pgdat
->node_start_pfn
- start
;
7071 /* ia64 gets its own node_mem_map, before this, without bootmem */
7072 if (!pgdat
->node_mem_map
) {
7073 unsigned long size
, end
;
7077 * The zone's endpoints aren't required to be MAX_ORDER
7078 * aligned but the node_mem_map endpoints must be in order
7079 * for the buddy allocator to function correctly.
7081 end
= pgdat_end_pfn(pgdat
);
7082 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
7083 size
= (end
- start
) * sizeof(struct page
);
7084 map
= memblock_alloc_node(size
, SMP_CACHE_BYTES
,
7087 panic("Failed to allocate %ld bytes for node %d memory map\n",
7088 size
, pgdat
->node_id
);
7089 pgdat
->node_mem_map
= map
+ offset
;
7091 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
7092 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
7093 (unsigned long)pgdat
->node_mem_map
);
7094 #ifndef CONFIG_NEED_MULTIPLE_NODES
7096 * With no DISCONTIG, the global mem_map is just set as node 0's
7098 if (pgdat
== NODE_DATA(0)) {
7099 mem_map
= NODE_DATA(0)->node_mem_map
;
7100 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
7106 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
7107 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
7109 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
7110 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
)
7112 pgdat
->first_deferred_pfn
= ULONG_MAX
;
7115 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
) {}
7118 static void __init
free_area_init_node(int nid
)
7120 pg_data_t
*pgdat
= NODE_DATA(nid
);
7121 unsigned long start_pfn
= 0;
7122 unsigned long end_pfn
= 0;
7124 /* pg_data_t should be reset to zero when it's allocated */
7125 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_highest_zoneidx
);
7127 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
7129 pgdat
->node_id
= nid
;
7130 pgdat
->node_start_pfn
= start_pfn
;
7131 pgdat
->per_cpu_nodestats
= NULL
;
7133 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
7134 (u64
)start_pfn
<< PAGE_SHIFT
,
7135 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
7136 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
);
7138 alloc_node_mem_map(pgdat
);
7139 pgdat_set_deferred_range(pgdat
);
7141 free_area_init_core(pgdat
);
7144 void __init
free_area_init_memoryless_node(int nid
)
7146 free_area_init_node(nid
);
7149 #if MAX_NUMNODES > 1
7151 * Figure out the number of possible node ids.
7153 void __init
setup_nr_node_ids(void)
7155 unsigned int highest
;
7157 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
7158 nr_node_ids
= highest
+ 1;
7163 * node_map_pfn_alignment - determine the maximum internode alignment
7165 * This function should be called after node map is populated and sorted.
7166 * It calculates the maximum power of two alignment which can distinguish
7169 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7170 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7171 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7172 * shifted, 1GiB is enough and this function will indicate so.
7174 * This is used to test whether pfn -> nid mapping of the chosen memory
7175 * model has fine enough granularity to avoid incorrect mapping for the
7176 * populated node map.
7178 * Return: the determined alignment in pfn's. 0 if there is no alignment
7179 * requirement (single node).
7181 unsigned long __init
node_map_pfn_alignment(void)
7183 unsigned long accl_mask
= 0, last_end
= 0;
7184 unsigned long start
, end
, mask
;
7185 int last_nid
= NUMA_NO_NODE
;
7188 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
7189 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
7196 * Start with a mask granular enough to pin-point to the
7197 * start pfn and tick off bits one-by-one until it becomes
7198 * too coarse to separate the current node from the last.
7200 mask
= ~((1 << __ffs(start
)) - 1);
7201 while (mask
&& last_end
<= (start
& (mask
<< 1)))
7204 /* accumulate all internode masks */
7208 /* convert mask to number of pages */
7209 return ~accl_mask
+ 1;
7213 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7215 * Return: the minimum PFN based on information provided via
7216 * memblock_set_node().
7218 unsigned long __init
find_min_pfn_with_active_regions(void)
7220 return PHYS_PFN(memblock_start_of_DRAM());
7224 * early_calculate_totalpages()
7225 * Sum pages in active regions for movable zone.
7226 * Populate N_MEMORY for calculating usable_nodes.
7228 static unsigned long __init
early_calculate_totalpages(void)
7230 unsigned long totalpages
= 0;
7231 unsigned long start_pfn
, end_pfn
;
7234 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7235 unsigned long pages
= end_pfn
- start_pfn
;
7237 totalpages
+= pages
;
7239 node_set_state(nid
, N_MEMORY
);
7245 * Find the PFN the Movable zone begins in each node. Kernel memory
7246 * is spread evenly between nodes as long as the nodes have enough
7247 * memory. When they don't, some nodes will have more kernelcore than
7250 static void __init
find_zone_movable_pfns_for_nodes(void)
7253 unsigned long usable_startpfn
;
7254 unsigned long kernelcore_node
, kernelcore_remaining
;
7255 /* save the state before borrow the nodemask */
7256 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
7257 unsigned long totalpages
= early_calculate_totalpages();
7258 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
7259 struct memblock_region
*r
;
7261 /* Need to find movable_zone earlier when movable_node is specified. */
7262 find_usable_zone_for_movable();
7265 * If movable_node is specified, ignore kernelcore and movablecore
7268 if (movable_node_is_enabled()) {
7269 for_each_mem_region(r
) {
7270 if (!memblock_is_hotpluggable(r
))
7273 nid
= memblock_get_region_node(r
);
7275 usable_startpfn
= PFN_DOWN(r
->base
);
7276 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7277 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7285 * If kernelcore=mirror is specified, ignore movablecore option
7287 if (mirrored_kernelcore
) {
7288 bool mem_below_4gb_not_mirrored
= false;
7290 for_each_mem_region(r
) {
7291 if (memblock_is_mirror(r
))
7294 nid
= memblock_get_region_node(r
);
7296 usable_startpfn
= memblock_region_memory_base_pfn(r
);
7298 if (usable_startpfn
< 0x100000) {
7299 mem_below_4gb_not_mirrored
= true;
7303 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7304 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7308 if (mem_below_4gb_not_mirrored
)
7309 pr_warn("This configuration results in unmirrored kernel memory.\n");
7315 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7316 * amount of necessary memory.
7318 if (required_kernelcore_percent
)
7319 required_kernelcore
= (totalpages
* 100 * required_kernelcore_percent
) /
7321 if (required_movablecore_percent
)
7322 required_movablecore
= (totalpages
* 100 * required_movablecore_percent
) /
7326 * If movablecore= was specified, calculate what size of
7327 * kernelcore that corresponds so that memory usable for
7328 * any allocation type is evenly spread. If both kernelcore
7329 * and movablecore are specified, then the value of kernelcore
7330 * will be used for required_kernelcore if it's greater than
7331 * what movablecore would have allowed.
7333 if (required_movablecore
) {
7334 unsigned long corepages
;
7337 * Round-up so that ZONE_MOVABLE is at least as large as what
7338 * was requested by the user
7340 required_movablecore
=
7341 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
7342 required_movablecore
= min(totalpages
, required_movablecore
);
7343 corepages
= totalpages
- required_movablecore
;
7345 required_kernelcore
= max(required_kernelcore
, corepages
);
7349 * If kernelcore was not specified or kernelcore size is larger
7350 * than totalpages, there is no ZONE_MOVABLE.
7352 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
7355 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7356 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
7359 /* Spread kernelcore memory as evenly as possible throughout nodes */
7360 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7361 for_each_node_state(nid
, N_MEMORY
) {
7362 unsigned long start_pfn
, end_pfn
;
7365 * Recalculate kernelcore_node if the division per node
7366 * now exceeds what is necessary to satisfy the requested
7367 * amount of memory for the kernel
7369 if (required_kernelcore
< kernelcore_node
)
7370 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7373 * As the map is walked, we track how much memory is usable
7374 * by the kernel using kernelcore_remaining. When it is
7375 * 0, the rest of the node is usable by ZONE_MOVABLE
7377 kernelcore_remaining
= kernelcore_node
;
7379 /* Go through each range of PFNs within this node */
7380 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
7381 unsigned long size_pages
;
7383 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
7384 if (start_pfn
>= end_pfn
)
7387 /* Account for what is only usable for kernelcore */
7388 if (start_pfn
< usable_startpfn
) {
7389 unsigned long kernel_pages
;
7390 kernel_pages
= min(end_pfn
, usable_startpfn
)
7393 kernelcore_remaining
-= min(kernel_pages
,
7394 kernelcore_remaining
);
7395 required_kernelcore
-= min(kernel_pages
,
7396 required_kernelcore
);
7398 /* Continue if range is now fully accounted */
7399 if (end_pfn
<= usable_startpfn
) {
7402 * Push zone_movable_pfn to the end so
7403 * that if we have to rebalance
7404 * kernelcore across nodes, we will
7405 * not double account here
7407 zone_movable_pfn
[nid
] = end_pfn
;
7410 start_pfn
= usable_startpfn
;
7414 * The usable PFN range for ZONE_MOVABLE is from
7415 * start_pfn->end_pfn. Calculate size_pages as the
7416 * number of pages used as kernelcore
7418 size_pages
= end_pfn
- start_pfn
;
7419 if (size_pages
> kernelcore_remaining
)
7420 size_pages
= kernelcore_remaining
;
7421 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
7424 * Some kernelcore has been met, update counts and
7425 * break if the kernelcore for this node has been
7428 required_kernelcore
-= min(required_kernelcore
,
7430 kernelcore_remaining
-= size_pages
;
7431 if (!kernelcore_remaining
)
7437 * If there is still required_kernelcore, we do another pass with one
7438 * less node in the count. This will push zone_movable_pfn[nid] further
7439 * along on the nodes that still have memory until kernelcore is
7443 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
7447 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7448 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
7449 zone_movable_pfn
[nid
] =
7450 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
7453 /* restore the node_state */
7454 node_states
[N_MEMORY
] = saved_node_state
;
7457 /* Any regular or high memory on that node ? */
7458 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
7460 enum zone_type zone_type
;
7462 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
7463 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
7464 if (populated_zone(zone
)) {
7465 if (IS_ENABLED(CONFIG_HIGHMEM
))
7466 node_set_state(nid
, N_HIGH_MEMORY
);
7467 if (zone_type
<= ZONE_NORMAL
)
7468 node_set_state(nid
, N_NORMAL_MEMORY
);
7475 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7476 * such cases we allow max_zone_pfn sorted in the descending order
7478 bool __weak
arch_has_descending_max_zone_pfns(void)
7484 * free_area_init - Initialise all pg_data_t and zone data
7485 * @max_zone_pfn: an array of max PFNs for each zone
7487 * This will call free_area_init_node() for each active node in the system.
7488 * Using the page ranges provided by memblock_set_node(), the size of each
7489 * zone in each node and their holes is calculated. If the maximum PFN
7490 * between two adjacent zones match, it is assumed that the zone is empty.
7491 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7492 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7493 * starts where the previous one ended. For example, ZONE_DMA32 starts
7494 * at arch_max_dma_pfn.
7496 void __init
free_area_init(unsigned long *max_zone_pfn
)
7498 unsigned long start_pfn
, end_pfn
;
7502 /* Record where the zone boundaries are */
7503 memset(arch_zone_lowest_possible_pfn
, 0,
7504 sizeof(arch_zone_lowest_possible_pfn
));
7505 memset(arch_zone_highest_possible_pfn
, 0,
7506 sizeof(arch_zone_highest_possible_pfn
));
7508 start_pfn
= find_min_pfn_with_active_regions();
7509 descending
= arch_has_descending_max_zone_pfns();
7511 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7513 zone
= MAX_NR_ZONES
- i
- 1;
7517 if (zone
== ZONE_MOVABLE
)
7520 end_pfn
= max(max_zone_pfn
[zone
], start_pfn
);
7521 arch_zone_lowest_possible_pfn
[zone
] = start_pfn
;
7522 arch_zone_highest_possible_pfn
[zone
] = end_pfn
;
7524 start_pfn
= end_pfn
;
7527 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7528 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
7529 find_zone_movable_pfns_for_nodes();
7531 /* Print out the zone ranges */
7532 pr_info("Zone ranges:\n");
7533 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7534 if (i
== ZONE_MOVABLE
)
7536 pr_info(" %-8s ", zone_names
[i
]);
7537 if (arch_zone_lowest_possible_pfn
[i
] ==
7538 arch_zone_highest_possible_pfn
[i
])
7541 pr_cont("[mem %#018Lx-%#018Lx]\n",
7542 (u64
)arch_zone_lowest_possible_pfn
[i
]
7544 ((u64
)arch_zone_highest_possible_pfn
[i
]
7545 << PAGE_SHIFT
) - 1);
7548 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7549 pr_info("Movable zone start for each node\n");
7550 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
7551 if (zone_movable_pfn
[i
])
7552 pr_info(" Node %d: %#018Lx\n", i
,
7553 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
7557 * Print out the early node map, and initialize the
7558 * subsection-map relative to active online memory ranges to
7559 * enable future "sub-section" extensions of the memory map.
7561 pr_info("Early memory node ranges\n");
7562 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7563 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
7564 (u64
)start_pfn
<< PAGE_SHIFT
,
7565 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
7566 subsection_map_init(start_pfn
, end_pfn
- start_pfn
);
7569 /* Initialise every node */
7570 mminit_verify_pageflags_layout();
7571 setup_nr_node_ids();
7572 for_each_online_node(nid
) {
7573 pg_data_t
*pgdat
= NODE_DATA(nid
);
7574 free_area_init_node(nid
);
7576 /* Any memory on that node */
7577 if (pgdat
->node_present_pages
)
7578 node_set_state(nid
, N_MEMORY
);
7579 check_for_memory(pgdat
, nid
);
7583 static int __init
cmdline_parse_core(char *p
, unsigned long *core
,
7584 unsigned long *percent
)
7586 unsigned long long coremem
;
7592 /* Value may be a percentage of total memory, otherwise bytes */
7593 coremem
= simple_strtoull(p
, &endptr
, 0);
7594 if (*endptr
== '%') {
7595 /* Paranoid check for percent values greater than 100 */
7596 WARN_ON(coremem
> 100);
7600 coremem
= memparse(p
, &p
);
7601 /* Paranoid check that UL is enough for the coremem value */
7602 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
7604 *core
= coremem
>> PAGE_SHIFT
;
7611 * kernelcore=size sets the amount of memory for use for allocations that
7612 * cannot be reclaimed or migrated.
7614 static int __init
cmdline_parse_kernelcore(char *p
)
7616 /* parse kernelcore=mirror */
7617 if (parse_option_str(p
, "mirror")) {
7618 mirrored_kernelcore
= true;
7622 return cmdline_parse_core(p
, &required_kernelcore
,
7623 &required_kernelcore_percent
);
7627 * movablecore=size sets the amount of memory for use for allocations that
7628 * can be reclaimed or migrated.
7630 static int __init
cmdline_parse_movablecore(char *p
)
7632 return cmdline_parse_core(p
, &required_movablecore
,
7633 &required_movablecore_percent
);
7636 early_param("kernelcore", cmdline_parse_kernelcore
);
7637 early_param("movablecore", cmdline_parse_movablecore
);
7639 void adjust_managed_page_count(struct page
*page
, long count
)
7641 atomic_long_add(count
, &page_zone(page
)->managed_pages
);
7642 totalram_pages_add(count
);
7643 #ifdef CONFIG_HIGHMEM
7644 if (PageHighMem(page
))
7645 totalhigh_pages_add(count
);
7648 EXPORT_SYMBOL(adjust_managed_page_count
);
7650 unsigned long free_reserved_area(void *start
, void *end
, int poison
, const char *s
)
7653 unsigned long pages
= 0;
7655 start
= (void *)PAGE_ALIGN((unsigned long)start
);
7656 end
= (void *)((unsigned long)end
& PAGE_MASK
);
7657 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
7658 struct page
*page
= virt_to_page(pos
);
7659 void *direct_map_addr
;
7662 * 'direct_map_addr' might be different from 'pos'
7663 * because some architectures' virt_to_page()
7664 * work with aliases. Getting the direct map
7665 * address ensures that we get a _writeable_
7666 * alias for the memset().
7668 direct_map_addr
= page_address(page
);
7670 * Perform a kasan-unchecked memset() since this memory
7671 * has not been initialized.
7673 direct_map_addr
= kasan_reset_tag(direct_map_addr
);
7674 if ((unsigned int)poison
<= 0xFF)
7675 memset(direct_map_addr
, poison
, PAGE_SIZE
);
7677 free_reserved_page(page
);
7681 pr_info("Freeing %s memory: %ldK\n",
7682 s
, pages
<< (PAGE_SHIFT
- 10));
7687 #ifdef CONFIG_HIGHMEM
7688 void free_highmem_page(struct page
*page
)
7690 __free_reserved_page(page
);
7691 totalram_pages_inc();
7692 atomic_long_inc(&page_zone(page
)->managed_pages
);
7693 totalhigh_pages_inc();
7698 void __init
mem_init_print_info(const char *str
)
7700 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
7701 unsigned long init_code_size
, init_data_size
;
7703 physpages
= get_num_physpages();
7704 codesize
= _etext
- _stext
;
7705 datasize
= _edata
- _sdata
;
7706 rosize
= __end_rodata
- __start_rodata
;
7707 bss_size
= __bss_stop
- __bss_start
;
7708 init_data_size
= __init_end
- __init_begin
;
7709 init_code_size
= _einittext
- _sinittext
;
7712 * Detect special cases and adjust section sizes accordingly:
7713 * 1) .init.* may be embedded into .data sections
7714 * 2) .init.text.* may be out of [__init_begin, __init_end],
7715 * please refer to arch/tile/kernel/vmlinux.lds.S.
7716 * 3) .rodata.* may be embedded into .text or .data sections.
7718 #define adj_init_size(start, end, size, pos, adj) \
7720 if (start <= pos && pos < end && size > adj) \
7724 adj_init_size(__init_begin
, __init_end
, init_data_size
,
7725 _sinittext
, init_code_size
);
7726 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
7727 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
7728 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
7729 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
7731 #undef adj_init_size
7733 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7734 #ifdef CONFIG_HIGHMEM
7738 nr_free_pages() << (PAGE_SHIFT
- 10),
7739 physpages
<< (PAGE_SHIFT
- 10),
7740 codesize
>> 10, datasize
>> 10, rosize
>> 10,
7741 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
7742 (physpages
- totalram_pages() - totalcma_pages
) << (PAGE_SHIFT
- 10),
7743 totalcma_pages
<< (PAGE_SHIFT
- 10),
7744 #ifdef CONFIG_HIGHMEM
7745 totalhigh_pages() << (PAGE_SHIFT
- 10),
7747 str
? ", " : "", str
? str
: "");
7751 * set_dma_reserve - set the specified number of pages reserved in the first zone
7752 * @new_dma_reserve: The number of pages to mark reserved
7754 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7755 * In the DMA zone, a significant percentage may be consumed by kernel image
7756 * and other unfreeable allocations which can skew the watermarks badly. This
7757 * function may optionally be used to account for unfreeable pages in the
7758 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7759 * smaller per-cpu batchsize.
7761 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
7763 dma_reserve
= new_dma_reserve
;
7766 static int page_alloc_cpu_dead(unsigned int cpu
)
7769 lru_add_drain_cpu(cpu
);
7773 * Spill the event counters of the dead processor
7774 * into the current processors event counters.
7775 * This artificially elevates the count of the current
7778 vm_events_fold_cpu(cpu
);
7781 * Zero the differential counters of the dead processor
7782 * so that the vm statistics are consistent.
7784 * This is only okay since the processor is dead and cannot
7785 * race with what we are doing.
7787 cpu_vm_stats_fold(cpu
);
7792 int hashdist
= HASHDIST_DEFAULT
;
7794 static int __init
set_hashdist(char *str
)
7798 hashdist
= simple_strtoul(str
, &str
, 0);
7801 __setup("hashdist=", set_hashdist
);
7804 void __init
page_alloc_init(void)
7809 if (num_node_state(N_MEMORY
) == 1)
7813 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
7814 "mm/page_alloc:dead", NULL
,
7815 page_alloc_cpu_dead
);
7820 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7821 * or min_free_kbytes changes.
7823 static void calculate_totalreserve_pages(void)
7825 struct pglist_data
*pgdat
;
7826 unsigned long reserve_pages
= 0;
7827 enum zone_type i
, j
;
7829 for_each_online_pgdat(pgdat
) {
7831 pgdat
->totalreserve_pages
= 0;
7833 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7834 struct zone
*zone
= pgdat
->node_zones
+ i
;
7836 unsigned long managed_pages
= zone_managed_pages(zone
);
7838 /* Find valid and maximum lowmem_reserve in the zone */
7839 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
7840 if (zone
->lowmem_reserve
[j
] > max
)
7841 max
= zone
->lowmem_reserve
[j
];
7844 /* we treat the high watermark as reserved pages. */
7845 max
+= high_wmark_pages(zone
);
7847 if (max
> managed_pages
)
7848 max
= managed_pages
;
7850 pgdat
->totalreserve_pages
+= max
;
7852 reserve_pages
+= max
;
7855 totalreserve_pages
= reserve_pages
;
7859 * setup_per_zone_lowmem_reserve - called whenever
7860 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7861 * has a correct pages reserved value, so an adequate number of
7862 * pages are left in the zone after a successful __alloc_pages().
7864 static void setup_per_zone_lowmem_reserve(void)
7866 struct pglist_data
*pgdat
;
7867 enum zone_type i
, j
;
7869 for_each_online_pgdat(pgdat
) {
7870 for (i
= 0; i
< MAX_NR_ZONES
- 1; i
++) {
7871 struct zone
*zone
= &pgdat
->node_zones
[i
];
7872 int ratio
= sysctl_lowmem_reserve_ratio
[i
];
7873 bool clear
= !ratio
|| !zone_managed_pages(zone
);
7874 unsigned long managed_pages
= 0;
7876 for (j
= i
+ 1; j
< MAX_NR_ZONES
; j
++) {
7878 zone
->lowmem_reserve
[j
] = 0;
7880 struct zone
*upper_zone
= &pgdat
->node_zones
[j
];
7882 managed_pages
+= zone_managed_pages(upper_zone
);
7883 zone
->lowmem_reserve
[j
] = managed_pages
/ ratio
;
7889 /* update totalreserve_pages */
7890 calculate_totalreserve_pages();
7893 static void __setup_per_zone_wmarks(void)
7895 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
7896 unsigned long lowmem_pages
= 0;
7898 unsigned long flags
;
7900 /* Calculate total number of !ZONE_HIGHMEM pages */
7901 for_each_zone(zone
) {
7902 if (!is_highmem(zone
))
7903 lowmem_pages
+= zone_managed_pages(zone
);
7906 for_each_zone(zone
) {
7909 spin_lock_irqsave(&zone
->lock
, flags
);
7910 tmp
= (u64
)pages_min
* zone_managed_pages(zone
);
7911 do_div(tmp
, lowmem_pages
);
7912 if (is_highmem(zone
)) {
7914 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7915 * need highmem pages, so cap pages_min to a small
7918 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7919 * deltas control async page reclaim, and so should
7920 * not be capped for highmem.
7922 unsigned long min_pages
;
7924 min_pages
= zone_managed_pages(zone
) / 1024;
7925 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7926 zone
->_watermark
[WMARK_MIN
] = min_pages
;
7929 * If it's a lowmem zone, reserve a number of pages
7930 * proportionate to the zone's size.
7932 zone
->_watermark
[WMARK_MIN
] = tmp
;
7936 * Set the kswapd watermarks distance according to the
7937 * scale factor in proportion to available memory, but
7938 * ensure a minimum size on small systems.
7940 tmp
= max_t(u64
, tmp
>> 2,
7941 mult_frac(zone_managed_pages(zone
),
7942 watermark_scale_factor
, 10000));
7944 zone
->watermark_boost
= 0;
7945 zone
->_watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7946 zone
->_watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7948 spin_unlock_irqrestore(&zone
->lock
, flags
);
7951 /* update totalreserve_pages */
7952 calculate_totalreserve_pages();
7956 * setup_per_zone_wmarks - called when min_free_kbytes changes
7957 * or when memory is hot-{added|removed}
7959 * Ensures that the watermark[min,low,high] values for each zone are set
7960 * correctly with respect to min_free_kbytes.
7962 void setup_per_zone_wmarks(void)
7964 static DEFINE_SPINLOCK(lock
);
7967 __setup_per_zone_wmarks();
7972 * Initialise min_free_kbytes.
7974 * For small machines we want it small (128k min). For large machines
7975 * we want it large (256MB max). But it is not linear, because network
7976 * bandwidth does not increase linearly with machine size. We use
7978 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7979 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7995 int __meminit
init_per_zone_wmark_min(void)
7997 unsigned long lowmem_kbytes
;
7998 int new_min_free_kbytes
;
8000 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
8001 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
8003 if (new_min_free_kbytes
> user_min_free_kbytes
) {
8004 min_free_kbytes
= new_min_free_kbytes
;
8005 if (min_free_kbytes
< 128)
8006 min_free_kbytes
= 128;
8007 if (min_free_kbytes
> 262144)
8008 min_free_kbytes
= 262144;
8010 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
8011 new_min_free_kbytes
, user_min_free_kbytes
);
8013 setup_per_zone_wmarks();
8014 refresh_zone_stat_thresholds();
8015 setup_per_zone_lowmem_reserve();
8018 setup_min_unmapped_ratio();
8019 setup_min_slab_ratio();
8022 khugepaged_min_free_kbytes_update();
8026 postcore_initcall(init_per_zone_wmark_min
)
8029 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
8030 * that we can call two helper functions whenever min_free_kbytes
8033 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
8034 void *buffer
, size_t *length
, loff_t
*ppos
)
8038 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8043 user_min_free_kbytes
= min_free_kbytes
;
8044 setup_per_zone_wmarks();
8049 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
8050 void *buffer
, size_t *length
, loff_t
*ppos
)
8054 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8059 setup_per_zone_wmarks();
8065 static void setup_min_unmapped_ratio(void)
8070 for_each_online_pgdat(pgdat
)
8071 pgdat
->min_unmapped_pages
= 0;
8074 zone
->zone_pgdat
->min_unmapped_pages
+= (zone_managed_pages(zone
) *
8075 sysctl_min_unmapped_ratio
) / 100;
8079 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8080 void *buffer
, size_t *length
, loff_t
*ppos
)
8084 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8088 setup_min_unmapped_ratio();
8093 static void setup_min_slab_ratio(void)
8098 for_each_online_pgdat(pgdat
)
8099 pgdat
->min_slab_pages
= 0;
8102 zone
->zone_pgdat
->min_slab_pages
+= (zone_managed_pages(zone
) *
8103 sysctl_min_slab_ratio
) / 100;
8106 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8107 void *buffer
, size_t *length
, loff_t
*ppos
)
8111 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8115 setup_min_slab_ratio();
8122 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8123 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8124 * whenever sysctl_lowmem_reserve_ratio changes.
8126 * The reserve ratio obviously has absolutely no relation with the
8127 * minimum watermarks. The lowmem reserve ratio can only make sense
8128 * if in function of the boot time zone sizes.
8130 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8131 void *buffer
, size_t *length
, loff_t
*ppos
)
8135 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8137 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
8138 if (sysctl_lowmem_reserve_ratio
[i
] < 1)
8139 sysctl_lowmem_reserve_ratio
[i
] = 0;
8142 setup_per_zone_lowmem_reserve();
8147 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8148 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8149 * pagelist can have before it gets flushed back to buddy allocator.
8151 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
8152 void *buffer
, size_t *length
, loff_t
*ppos
)
8155 int old_percpu_pagelist_fraction
;
8158 mutex_lock(&pcp_batch_high_lock
);
8159 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
8161 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8162 if (!write
|| ret
< 0)
8165 /* Sanity checking to avoid pcp imbalance */
8166 if (percpu_pagelist_fraction
&&
8167 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
8168 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
8174 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
8177 for_each_populated_zone(zone
)
8178 zone_set_pageset_high_and_batch(zone
);
8180 mutex_unlock(&pcp_batch_high_lock
);
8184 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8186 * Returns the number of pages that arch has reserved but
8187 * is not known to alloc_large_system_hash().
8189 static unsigned long __init
arch_reserved_kernel_pages(void)
8196 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8197 * machines. As memory size is increased the scale is also increased but at
8198 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8199 * quadruples the scale is increased by one, which means the size of hash table
8200 * only doubles, instead of quadrupling as well.
8201 * Because 32-bit systems cannot have large physical memory, where this scaling
8202 * makes sense, it is disabled on such platforms.
8204 #if __BITS_PER_LONG > 32
8205 #define ADAPT_SCALE_BASE (64ul << 30)
8206 #define ADAPT_SCALE_SHIFT 2
8207 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8211 * allocate a large system hash table from bootmem
8212 * - it is assumed that the hash table must contain an exact power-of-2
8213 * quantity of entries
8214 * - limit is the number of hash buckets, not the total allocation size
8216 void *__init
alloc_large_system_hash(const char *tablename
,
8217 unsigned long bucketsize
,
8218 unsigned long numentries
,
8221 unsigned int *_hash_shift
,
8222 unsigned int *_hash_mask
,
8223 unsigned long low_limit
,
8224 unsigned long high_limit
)
8226 unsigned long long max
= high_limit
;
8227 unsigned long log2qty
, size
;
8232 /* allow the kernel cmdline to have a say */
8234 /* round applicable memory size up to nearest megabyte */
8235 numentries
= nr_kernel_pages
;
8236 numentries
-= arch_reserved_kernel_pages();
8238 /* It isn't necessary when PAGE_SIZE >= 1MB */
8239 if (PAGE_SHIFT
< 20)
8240 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
8242 #if __BITS_PER_LONG > 32
8244 unsigned long adapt
;
8246 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
8247 adapt
<<= ADAPT_SCALE_SHIFT
)
8252 /* limit to 1 bucket per 2^scale bytes of low memory */
8253 if (scale
> PAGE_SHIFT
)
8254 numentries
>>= (scale
- PAGE_SHIFT
);
8256 numentries
<<= (PAGE_SHIFT
- scale
);
8258 /* Make sure we've got at least a 0-order allocation.. */
8259 if (unlikely(flags
& HASH_SMALL
)) {
8260 /* Makes no sense without HASH_EARLY */
8261 WARN_ON(!(flags
& HASH_EARLY
));
8262 if (!(numentries
>> *_hash_shift
)) {
8263 numentries
= 1UL << *_hash_shift
;
8264 BUG_ON(!numentries
);
8266 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
8267 numentries
= PAGE_SIZE
/ bucketsize
;
8269 numentries
= roundup_pow_of_two(numentries
);
8271 /* limit allocation size to 1/16 total memory by default */
8273 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
8274 do_div(max
, bucketsize
);
8276 max
= min(max
, 0x80000000ULL
);
8278 if (numentries
< low_limit
)
8279 numentries
= low_limit
;
8280 if (numentries
> max
)
8283 log2qty
= ilog2(numentries
);
8285 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
8288 size
= bucketsize
<< log2qty
;
8289 if (flags
& HASH_EARLY
) {
8290 if (flags
& HASH_ZERO
)
8291 table
= memblock_alloc(size
, SMP_CACHE_BYTES
);
8293 table
= memblock_alloc_raw(size
,
8295 } else if (get_order(size
) >= MAX_ORDER
|| hashdist
) {
8296 table
= __vmalloc(size
, gfp_flags
);
8300 * If bucketsize is not a power-of-two, we may free
8301 * some pages at the end of hash table which
8302 * alloc_pages_exact() automatically does
8304 table
= alloc_pages_exact(size
, gfp_flags
);
8305 kmemleak_alloc(table
, size
, 1, gfp_flags
);
8307 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
8310 panic("Failed to allocate %s hash table\n", tablename
);
8312 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8313 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
,
8314 virt
? "vmalloc" : "linear");
8317 *_hash_shift
= log2qty
;
8319 *_hash_mask
= (1 << log2qty
) - 1;
8325 * This function checks whether pageblock includes unmovable pages or not.
8327 * PageLRU check without isolation or lru_lock could race so that
8328 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8329 * check without lock_page also may miss some movable non-lru pages at
8330 * race condition. So you can't expect this function should be exact.
8332 * Returns a page without holding a reference. If the caller wants to
8333 * dereference that page (e.g., dumping), it has to make sure that it
8334 * cannot get removed (e.g., via memory unplug) concurrently.
8337 struct page
*has_unmovable_pages(struct zone
*zone
, struct page
*page
,
8338 int migratetype
, int flags
)
8340 unsigned long iter
= 0;
8341 unsigned long pfn
= page_to_pfn(page
);
8342 unsigned long offset
= pfn
% pageblock_nr_pages
;
8344 if (is_migrate_cma_page(page
)) {
8346 * CMA allocations (alloc_contig_range) really need to mark
8347 * isolate CMA pageblocks even when they are not movable in fact
8348 * so consider them movable here.
8350 if (is_migrate_cma(migratetype
))
8356 for (; iter
< pageblock_nr_pages
- offset
; iter
++) {
8357 if (!pfn_valid_within(pfn
+ iter
))
8360 page
= pfn_to_page(pfn
+ iter
);
8363 * Both, bootmem allocations and memory holes are marked
8364 * PG_reserved and are unmovable. We can even have unmovable
8365 * allocations inside ZONE_MOVABLE, for example when
8366 * specifying "movablecore".
8368 if (PageReserved(page
))
8372 * If the zone is movable and we have ruled out all reserved
8373 * pages then it should be reasonably safe to assume the rest
8376 if (zone_idx(zone
) == ZONE_MOVABLE
)
8380 * Hugepages are not in LRU lists, but they're movable.
8381 * THPs are on the LRU, but need to be counted as #small pages.
8382 * We need not scan over tail pages because we don't
8383 * handle each tail page individually in migration.
8385 if (PageHuge(page
) || PageTransCompound(page
)) {
8386 struct page
*head
= compound_head(page
);
8387 unsigned int skip_pages
;
8389 if (PageHuge(page
)) {
8390 if (!hugepage_migration_supported(page_hstate(head
)))
8392 } else if (!PageLRU(head
) && !__PageMovable(head
)) {
8396 skip_pages
= compound_nr(head
) - (page
- head
);
8397 iter
+= skip_pages
- 1;
8402 * We can't use page_count without pin a page
8403 * because another CPU can free compound page.
8404 * This check already skips compound tails of THP
8405 * because their page->_refcount is zero at all time.
8407 if (!page_ref_count(page
)) {
8408 if (PageBuddy(page
))
8409 iter
+= (1 << buddy_order(page
)) - 1;
8414 * The HWPoisoned page may be not in buddy system, and
8415 * page_count() is not 0.
8417 if ((flags
& MEMORY_OFFLINE
) && PageHWPoison(page
))
8421 * We treat all PageOffline() pages as movable when offlining
8422 * to give drivers a chance to decrement their reference count
8423 * in MEM_GOING_OFFLINE in order to indicate that these pages
8424 * can be offlined as there are no direct references anymore.
8425 * For actually unmovable PageOffline() where the driver does
8426 * not support this, we will fail later when trying to actually
8427 * move these pages that still have a reference count > 0.
8428 * (false negatives in this function only)
8430 if ((flags
& MEMORY_OFFLINE
) && PageOffline(page
))
8433 if (__PageMovable(page
) || PageLRU(page
))
8437 * If there are RECLAIMABLE pages, we need to check
8438 * it. But now, memory offline itself doesn't call
8439 * shrink_node_slabs() and it still to be fixed.
8446 #ifdef CONFIG_CONTIG_ALLOC
8447 static unsigned long pfn_max_align_down(unsigned long pfn
)
8449 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8450 pageblock_nr_pages
) - 1);
8453 static unsigned long pfn_max_align_up(unsigned long pfn
)
8455 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8456 pageblock_nr_pages
));
8459 /* [start, end) must belong to a single zone. */
8460 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
8461 unsigned long start
, unsigned long end
)
8463 /* This function is based on compact_zone() from compaction.c. */
8464 unsigned int nr_reclaimed
;
8465 unsigned long pfn
= start
;
8466 unsigned int tries
= 0;
8468 struct migration_target_control mtc
= {
8469 .nid
= zone_to_nid(cc
->zone
),
8470 .gfp_mask
= GFP_USER
| __GFP_MOVABLE
| __GFP_RETRY_MAYFAIL
,
8475 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
8476 if (fatal_signal_pending(current
)) {
8481 if (list_empty(&cc
->migratepages
)) {
8482 cc
->nr_migratepages
= 0;
8483 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
8489 } else if (++tries
== 5) {
8490 ret
= ret
< 0 ? ret
: -EBUSY
;
8494 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
8496 cc
->nr_migratepages
-= nr_reclaimed
;
8498 ret
= migrate_pages(&cc
->migratepages
, alloc_migration_target
,
8499 NULL
, (unsigned long)&mtc
, cc
->mode
, MR_CONTIG_RANGE
);
8502 putback_movable_pages(&cc
->migratepages
);
8509 * alloc_contig_range() -- tries to allocate given range of pages
8510 * @start: start PFN to allocate
8511 * @end: one-past-the-last PFN to allocate
8512 * @migratetype: migratetype of the underlaying pageblocks (either
8513 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8514 * in range must have the same migratetype and it must
8515 * be either of the two.
8516 * @gfp_mask: GFP mask to use during compaction
8518 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8519 * aligned. The PFN range must belong to a single zone.
8521 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8522 * pageblocks in the range. Once isolated, the pageblocks should not
8523 * be modified by others.
8525 * Return: zero on success or negative error code. On success all
8526 * pages which PFN is in [start, end) are allocated for the caller and
8527 * need to be freed with free_contig_range().
8529 int alloc_contig_range(unsigned long start
, unsigned long end
,
8530 unsigned migratetype
, gfp_t gfp_mask
)
8532 unsigned long outer_start
, outer_end
;
8536 struct compact_control cc
= {
8537 .nr_migratepages
= 0,
8539 .zone
= page_zone(pfn_to_page(start
)),
8540 .mode
= MIGRATE_SYNC
,
8541 .ignore_skip_hint
= true,
8542 .no_set_skip_hint
= true,
8543 .gfp_mask
= current_gfp_context(gfp_mask
),
8544 .alloc_contig
= true,
8546 INIT_LIST_HEAD(&cc
.migratepages
);
8549 * What we do here is we mark all pageblocks in range as
8550 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8551 * have different sizes, and due to the way page allocator
8552 * work, we align the range to biggest of the two pages so
8553 * that page allocator won't try to merge buddies from
8554 * different pageblocks and change MIGRATE_ISOLATE to some
8555 * other migration type.
8557 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8558 * migrate the pages from an unaligned range (ie. pages that
8559 * we are interested in). This will put all the pages in
8560 * range back to page allocator as MIGRATE_ISOLATE.
8562 * When this is done, we take the pages in range from page
8563 * allocator removing them from the buddy system. This way
8564 * page allocator will never consider using them.
8566 * This lets us mark the pageblocks back as
8567 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8568 * aligned range but not in the unaligned, original range are
8569 * put back to page allocator so that buddy can use them.
8572 ret
= start_isolate_page_range(pfn_max_align_down(start
),
8573 pfn_max_align_up(end
), migratetype
, 0);
8577 drain_all_pages(cc
.zone
);
8580 * In case of -EBUSY, we'd like to know which page causes problem.
8581 * So, just fall through. test_pages_isolated() has a tracepoint
8582 * which will report the busy page.
8584 * It is possible that busy pages could become available before
8585 * the call to test_pages_isolated, and the range will actually be
8586 * allocated. So, if we fall through be sure to clear ret so that
8587 * -EBUSY is not accidentally used or returned to caller.
8589 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
8590 if (ret
&& ret
!= -EBUSY
)
8595 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8596 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8597 * more, all pages in [start, end) are free in page allocator.
8598 * What we are going to do is to allocate all pages from
8599 * [start, end) (that is remove them from page allocator).
8601 * The only problem is that pages at the beginning and at the
8602 * end of interesting range may be not aligned with pages that
8603 * page allocator holds, ie. they can be part of higher order
8604 * pages. Because of this, we reserve the bigger range and
8605 * once this is done free the pages we are not interested in.
8607 * We don't have to hold zone->lock here because the pages are
8608 * isolated thus they won't get removed from buddy.
8611 lru_add_drain_all();
8614 outer_start
= start
;
8615 while (!PageBuddy(pfn_to_page(outer_start
))) {
8616 if (++order
>= MAX_ORDER
) {
8617 outer_start
= start
;
8620 outer_start
&= ~0UL << order
;
8623 if (outer_start
!= start
) {
8624 order
= buddy_order(pfn_to_page(outer_start
));
8627 * outer_start page could be small order buddy page and
8628 * it doesn't include start page. Adjust outer_start
8629 * in this case to report failed page properly
8630 * on tracepoint in test_pages_isolated()
8632 if (outer_start
+ (1UL << order
) <= start
)
8633 outer_start
= start
;
8636 /* Make sure the range is really isolated. */
8637 if (test_pages_isolated(outer_start
, end
, 0)) {
8638 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8639 __func__
, outer_start
, end
);
8644 /* Grab isolated pages from freelists. */
8645 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
8651 /* Free head and tail (if any) */
8652 if (start
!= outer_start
)
8653 free_contig_range(outer_start
, start
- outer_start
);
8654 if (end
!= outer_end
)
8655 free_contig_range(end
, outer_end
- end
);
8658 undo_isolate_page_range(pfn_max_align_down(start
),
8659 pfn_max_align_up(end
), migratetype
);
8662 EXPORT_SYMBOL(alloc_contig_range
);
8664 static int __alloc_contig_pages(unsigned long start_pfn
,
8665 unsigned long nr_pages
, gfp_t gfp_mask
)
8667 unsigned long end_pfn
= start_pfn
+ nr_pages
;
8669 return alloc_contig_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
,
8673 static bool pfn_range_valid_contig(struct zone
*z
, unsigned long start_pfn
,
8674 unsigned long nr_pages
)
8676 unsigned long i
, end_pfn
= start_pfn
+ nr_pages
;
8679 for (i
= start_pfn
; i
< end_pfn
; i
++) {
8680 page
= pfn_to_online_page(i
);
8684 if (page_zone(page
) != z
)
8687 if (PageReserved(page
))
8690 if (page_count(page
) > 0)
8699 static bool zone_spans_last_pfn(const struct zone
*zone
,
8700 unsigned long start_pfn
, unsigned long nr_pages
)
8702 unsigned long last_pfn
= start_pfn
+ nr_pages
- 1;
8704 return zone_spans_pfn(zone
, last_pfn
);
8708 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8709 * @nr_pages: Number of contiguous pages to allocate
8710 * @gfp_mask: GFP mask to limit search and used during compaction
8712 * @nodemask: Mask for other possible nodes
8714 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8715 * on an applicable zonelist to find a contiguous pfn range which can then be
8716 * tried for allocation with alloc_contig_range(). This routine is intended
8717 * for allocation requests which can not be fulfilled with the buddy allocator.
8719 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8720 * power of two then the alignment is guaranteed to be to the given nr_pages
8721 * (e.g. 1GB request would be aligned to 1GB).
8723 * Allocated pages can be freed with free_contig_range() or by manually calling
8724 * __free_page() on each allocated page.
8726 * Return: pointer to contiguous pages on success, or NULL if not successful.
8728 struct page
*alloc_contig_pages(unsigned long nr_pages
, gfp_t gfp_mask
,
8729 int nid
, nodemask_t
*nodemask
)
8731 unsigned long ret
, pfn
, flags
;
8732 struct zonelist
*zonelist
;
8736 zonelist
= node_zonelist(nid
, gfp_mask
);
8737 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
8738 gfp_zone(gfp_mask
), nodemask
) {
8739 spin_lock_irqsave(&zone
->lock
, flags
);
8741 pfn
= ALIGN(zone
->zone_start_pfn
, nr_pages
);
8742 while (zone_spans_last_pfn(zone
, pfn
, nr_pages
)) {
8743 if (pfn_range_valid_contig(zone
, pfn
, nr_pages
)) {
8745 * We release the zone lock here because
8746 * alloc_contig_range() will also lock the zone
8747 * at some point. If there's an allocation
8748 * spinning on this lock, it may win the race
8749 * and cause alloc_contig_range() to fail...
8751 spin_unlock_irqrestore(&zone
->lock
, flags
);
8752 ret
= __alloc_contig_pages(pfn
, nr_pages
,
8755 return pfn_to_page(pfn
);
8756 spin_lock_irqsave(&zone
->lock
, flags
);
8760 spin_unlock_irqrestore(&zone
->lock
, flags
);
8764 #endif /* CONFIG_CONTIG_ALLOC */
8766 void free_contig_range(unsigned long pfn
, unsigned int nr_pages
)
8768 unsigned int count
= 0;
8770 for (; nr_pages
--; pfn
++) {
8771 struct page
*page
= pfn_to_page(pfn
);
8773 count
+= page_count(page
) != 1;
8776 WARN(count
!= 0, "%d pages are still in use!\n", count
);
8778 EXPORT_SYMBOL(free_contig_range
);
8781 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8782 * page high values need to be recalulated.
8784 void __meminit
zone_pcp_update(struct zone
*zone
)
8786 mutex_lock(&pcp_batch_high_lock
);
8787 zone_set_pageset_high_and_batch(zone
);
8788 mutex_unlock(&pcp_batch_high_lock
);
8792 * Effectively disable pcplists for the zone by setting the high limit to 0
8793 * and draining all cpus. A concurrent page freeing on another CPU that's about
8794 * to put the page on pcplist will either finish before the drain and the page
8795 * will be drained, or observe the new high limit and skip the pcplist.
8797 * Must be paired with a call to zone_pcp_enable().
8799 void zone_pcp_disable(struct zone
*zone
)
8801 mutex_lock(&pcp_batch_high_lock
);
8802 __zone_set_pageset_high_and_batch(zone
, 0, 1);
8803 __drain_all_pages(zone
, true);
8806 void zone_pcp_enable(struct zone
*zone
)
8808 __zone_set_pageset_high_and_batch(zone
, zone
->pageset_high
, zone
->pageset_batch
);
8809 mutex_unlock(&pcp_batch_high_lock
);
8812 void zone_pcp_reset(struct zone
*zone
)
8814 unsigned long flags
;
8816 struct per_cpu_pageset
*pset
;
8818 /* avoid races with drain_pages() */
8819 local_irq_save(flags
);
8820 if (zone
->pageset
!= &boot_pageset
) {
8821 for_each_online_cpu(cpu
) {
8822 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
8823 drain_zonestat(zone
, pset
);
8825 free_percpu(zone
->pageset
);
8826 zone
->pageset
= &boot_pageset
;
8828 local_irq_restore(flags
);
8831 #ifdef CONFIG_MEMORY_HOTREMOVE
8833 * All pages in the range must be in a single zone, must not contain holes,
8834 * must span full sections, and must be isolated before calling this function.
8836 void __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
8838 unsigned long pfn
= start_pfn
;
8842 unsigned long flags
;
8844 offline_mem_sections(pfn
, end_pfn
);
8845 zone
= page_zone(pfn_to_page(pfn
));
8846 spin_lock_irqsave(&zone
->lock
, flags
);
8847 while (pfn
< end_pfn
) {
8848 page
= pfn_to_page(pfn
);
8850 * The HWPoisoned page may be not in buddy system, and
8851 * page_count() is not 0.
8853 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
8858 * At this point all remaining PageOffline() pages have a
8859 * reference count of 0 and can simply be skipped.
8861 if (PageOffline(page
)) {
8862 BUG_ON(page_count(page
));
8863 BUG_ON(PageBuddy(page
));
8868 BUG_ON(page_count(page
));
8869 BUG_ON(!PageBuddy(page
));
8870 order
= buddy_order(page
);
8871 del_page_from_free_list(page
, zone
, order
);
8872 pfn
+= (1 << order
);
8874 spin_unlock_irqrestore(&zone
->lock
, flags
);
8878 bool is_free_buddy_page(struct page
*page
)
8880 struct zone
*zone
= page_zone(page
);
8881 unsigned long pfn
= page_to_pfn(page
);
8882 unsigned long flags
;
8885 spin_lock_irqsave(&zone
->lock
, flags
);
8886 for (order
= 0; order
< MAX_ORDER
; order
++) {
8887 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8889 if (PageBuddy(page_head
) && buddy_order(page_head
) >= order
)
8892 spin_unlock_irqrestore(&zone
->lock
, flags
);
8894 return order
< MAX_ORDER
;
8897 #ifdef CONFIG_MEMORY_FAILURE
8899 * Break down a higher-order page in sub-pages, and keep our target out of
8902 static void break_down_buddy_pages(struct zone
*zone
, struct page
*page
,
8903 struct page
*target
, int low
, int high
,
8906 unsigned long size
= 1 << high
;
8907 struct page
*current_buddy
, *next_page
;
8909 while (high
> low
) {
8913 if (target
>= &page
[size
]) {
8914 next_page
= page
+ size
;
8915 current_buddy
= page
;
8918 current_buddy
= page
+ size
;
8921 if (set_page_guard(zone
, current_buddy
, high
, migratetype
))
8924 if (current_buddy
!= target
) {
8925 add_to_free_list(current_buddy
, zone
, high
, migratetype
);
8926 set_buddy_order(current_buddy
, high
);
8933 * Take a page that will be marked as poisoned off the buddy allocator.
8935 bool take_page_off_buddy(struct page
*page
)
8937 struct zone
*zone
= page_zone(page
);
8938 unsigned long pfn
= page_to_pfn(page
);
8939 unsigned long flags
;
8943 spin_lock_irqsave(&zone
->lock
, flags
);
8944 for (order
= 0; order
< MAX_ORDER
; order
++) {
8945 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8946 int page_order
= buddy_order(page_head
);
8948 if (PageBuddy(page_head
) && page_order
>= order
) {
8949 unsigned long pfn_head
= page_to_pfn(page_head
);
8950 int migratetype
= get_pfnblock_migratetype(page_head
,
8953 del_page_from_free_list(page_head
, zone
, page_order
);
8954 break_down_buddy_pages(zone
, page_head
, page
, 0,
8955 page_order
, migratetype
);
8956 if (!is_migrate_isolate(migratetype
))
8957 __mod_zone_freepage_state(zone
, -1, migratetype
);
8961 if (page_count(page_head
) > 0)
8964 spin_unlock_irqrestore(&zone
->lock
, flags
);