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/migrate.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/sched/mm.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66 #include <linux/memcontrol.h>
67 #include <linux/ftrace.h>
68 #include <linux/lockdep.h>
69 #include <linux/nmi.h>
70 #include <linux/psi.h>
71 #include <linux/padata.h>
72 #include <linux/khugepaged.h>
74 #include <asm/sections.h>
75 #include <asm/tlbflush.h>
76 #include <asm/div64.h>
79 #include "page_reporting.h"
81 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
82 static DEFINE_MUTEX(pcp_batch_high_lock
);
83 #define MIN_PERCPU_PAGELIST_FRACTION (8)
85 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
86 DEFINE_PER_CPU(int, numa_node
);
87 EXPORT_PER_CPU_SYMBOL(numa_node
);
90 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
92 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
94 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
95 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
96 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
97 * defined in <linux/topology.h>.
99 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
100 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
103 /* work_structs for global per-cpu drains */
106 struct work_struct work
;
108 static DEFINE_MUTEX(pcpu_drain_mutex
);
109 static DEFINE_PER_CPU(struct pcpu_drain
, pcpu_drain
);
111 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
112 volatile unsigned long latent_entropy __latent_entropy
;
113 EXPORT_SYMBOL(latent_entropy
);
117 * Array of node states.
119 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
120 [N_POSSIBLE
] = NODE_MASK_ALL
,
121 [N_ONLINE
] = { { [0] = 1UL } },
123 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
124 #ifdef CONFIG_HIGHMEM
125 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
127 [N_MEMORY
] = { { [0] = 1UL } },
128 [N_CPU
] = { { [0] = 1UL } },
131 EXPORT_SYMBOL(node_states
);
133 atomic_long_t _totalram_pages __read_mostly
;
134 EXPORT_SYMBOL(_totalram_pages
);
135 unsigned long totalreserve_pages __read_mostly
;
136 unsigned long totalcma_pages __read_mostly
;
138 int percpu_pagelist_fraction
;
139 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
140 #ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
141 DEFINE_STATIC_KEY_TRUE(init_on_alloc
);
143 DEFINE_STATIC_KEY_FALSE(init_on_alloc
);
145 EXPORT_SYMBOL(init_on_alloc
);
147 #ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
148 DEFINE_STATIC_KEY_TRUE(init_on_free
);
150 DEFINE_STATIC_KEY_FALSE(init_on_free
);
152 EXPORT_SYMBOL(init_on_free
);
154 static int __init
early_init_on_alloc(char *buf
)
159 ret
= kstrtobool(buf
, &bool_result
);
162 if (bool_result
&& page_poisoning_enabled())
163 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_alloc\n");
165 static_branch_enable(&init_on_alloc
);
167 static_branch_disable(&init_on_alloc
);
170 early_param("init_on_alloc", early_init_on_alloc
);
172 static int __init
early_init_on_free(char *buf
)
177 ret
= kstrtobool(buf
, &bool_result
);
180 if (bool_result
&& page_poisoning_enabled())
181 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_free\n");
183 static_branch_enable(&init_on_free
);
185 static_branch_disable(&init_on_free
);
188 early_param("init_on_free", early_init_on_free
);
191 * A cached value of the page's pageblock's migratetype, used when the page is
192 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
193 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
194 * Also the migratetype set in the page does not necessarily match the pcplist
195 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
196 * other index - this ensures that it will be put on the correct CMA freelist.
198 static inline int get_pcppage_migratetype(struct page
*page
)
203 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
205 page
->index
= migratetype
;
208 #ifdef CONFIG_PM_SLEEP
210 * The following functions are used by the suspend/hibernate code to temporarily
211 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
212 * while devices are suspended. To avoid races with the suspend/hibernate code,
213 * they should always be called with system_transition_mutex held
214 * (gfp_allowed_mask also should only be modified with system_transition_mutex
215 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
216 * with that modification).
219 static gfp_t saved_gfp_mask
;
221 void pm_restore_gfp_mask(void)
223 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
224 if (saved_gfp_mask
) {
225 gfp_allowed_mask
= saved_gfp_mask
;
230 void pm_restrict_gfp_mask(void)
232 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
233 WARN_ON(saved_gfp_mask
);
234 saved_gfp_mask
= gfp_allowed_mask
;
235 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
238 bool pm_suspended_storage(void)
240 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
244 #endif /* CONFIG_PM_SLEEP */
246 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
247 unsigned int pageblock_order __read_mostly
;
250 static void __free_pages_ok(struct page
*page
, unsigned int order
);
253 * results with 256, 32 in the lowmem_reserve sysctl:
254 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
255 * 1G machine -> (16M dma, 784M normal, 224M high)
256 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
257 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
258 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
260 * TBD: should special case ZONE_DMA32 machines here - in those we normally
261 * don't need any ZONE_NORMAL reservation
263 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
] = {
264 #ifdef CONFIG_ZONE_DMA
267 #ifdef CONFIG_ZONE_DMA32
271 #ifdef CONFIG_HIGHMEM
277 static char * const zone_names
[MAX_NR_ZONES
] = {
278 #ifdef CONFIG_ZONE_DMA
281 #ifdef CONFIG_ZONE_DMA32
285 #ifdef CONFIG_HIGHMEM
289 #ifdef CONFIG_ZONE_DEVICE
294 const char * const migratetype_names
[MIGRATE_TYPES
] = {
302 #ifdef CONFIG_MEMORY_ISOLATION
307 compound_page_dtor
* const compound_page_dtors
[NR_COMPOUND_DTORS
] = {
308 [NULL_COMPOUND_DTOR
] = NULL
,
309 [COMPOUND_PAGE_DTOR
] = free_compound_page
,
310 #ifdef CONFIG_HUGETLB_PAGE
311 [HUGETLB_PAGE_DTOR
] = free_huge_page
,
313 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
314 [TRANSHUGE_PAGE_DTOR
] = free_transhuge_page
,
318 int min_free_kbytes
= 1024;
319 int user_min_free_kbytes
= -1;
320 #ifdef CONFIG_DISCONTIGMEM
322 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
323 * are not on separate NUMA nodes. Functionally this works but with
324 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
325 * quite small. By default, do not boost watermarks on discontigmem as in
326 * many cases very high-order allocations like THP are likely to be
327 * unsupported and the premature reclaim offsets the advantage of long-term
328 * fragmentation avoidance.
330 int watermark_boost_factor __read_mostly
;
332 int watermark_boost_factor __read_mostly
= 15000;
334 int watermark_scale_factor
= 10;
336 static unsigned long nr_kernel_pages __initdata
;
337 static unsigned long nr_all_pages __initdata
;
338 static unsigned long dma_reserve __initdata
;
340 static unsigned long arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
341 static unsigned long arch_zone_highest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
342 static unsigned long required_kernelcore __initdata
;
343 static unsigned long required_kernelcore_percent __initdata
;
344 static unsigned long required_movablecore __initdata
;
345 static unsigned long required_movablecore_percent __initdata
;
346 static unsigned long zone_movable_pfn
[MAX_NUMNODES
] __initdata
;
347 static bool mirrored_kernelcore __meminitdata
;
349 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
351 EXPORT_SYMBOL(movable_zone
);
354 unsigned int nr_node_ids __read_mostly
= MAX_NUMNODES
;
355 unsigned int nr_online_nodes __read_mostly
= 1;
356 EXPORT_SYMBOL(nr_node_ids
);
357 EXPORT_SYMBOL(nr_online_nodes
);
360 int page_group_by_mobility_disabled __read_mostly
;
362 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
364 * During boot we initialize deferred pages on-demand, as needed, but once
365 * page_alloc_init_late() has finished, the deferred pages are all initialized,
366 * and we can permanently disable that path.
368 static DEFINE_STATIC_KEY_TRUE(deferred_pages
);
371 * Calling kasan_free_pages() only after deferred memory initialization
372 * has completed. Poisoning pages during deferred memory init will greatly
373 * lengthen the process and cause problem in large memory systems as the
374 * deferred pages initialization is done with interrupt disabled.
376 * Assuming that there will be no reference to those newly initialized
377 * pages before they are ever allocated, this should have no effect on
378 * KASAN memory tracking as the poison will be properly inserted at page
379 * allocation time. The only corner case is when pages are allocated by
380 * on-demand allocation and then freed again before the deferred pages
381 * initialization is done, but this is not likely to happen.
383 static inline void kasan_free_nondeferred_pages(struct page
*page
, int order
)
385 if (!static_branch_unlikely(&deferred_pages
))
386 kasan_free_pages(page
, order
);
389 /* Returns true if the struct page for the pfn is uninitialised */
390 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
392 int nid
= early_pfn_to_nid(pfn
);
394 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
401 * Returns true when the remaining initialisation should be deferred until
402 * later in the boot cycle when it can be parallelised.
404 static bool __meminit
405 defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
407 static unsigned long prev_end_pfn
, nr_initialised
;
410 * prev_end_pfn static that contains the end of previous zone
411 * No need to protect because called very early in boot before smp_init.
413 if (prev_end_pfn
!= end_pfn
) {
414 prev_end_pfn
= end_pfn
;
418 /* Always populate low zones for address-constrained allocations */
419 if (end_pfn
< pgdat_end_pfn(NODE_DATA(nid
)))
423 * We start only with one section of pages, more pages are added as
424 * needed until the rest of deferred pages are initialized.
427 if ((nr_initialised
> PAGES_PER_SECTION
) &&
428 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
429 NODE_DATA(nid
)->first_deferred_pfn
= pfn
;
435 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
437 static inline bool early_page_uninitialised(unsigned long pfn
)
442 static inline bool defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
448 /* Return a pointer to the bitmap storing bits affecting a block of pages */
449 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
452 #ifdef CONFIG_SPARSEMEM
453 return section_to_usemap(__pfn_to_section(pfn
));
455 return page_zone(page
)->pageblock_flags
;
456 #endif /* CONFIG_SPARSEMEM */
459 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
461 #ifdef CONFIG_SPARSEMEM
462 pfn
&= (PAGES_PER_SECTION
-1);
464 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
465 #endif /* CONFIG_SPARSEMEM */
466 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
470 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
471 * @page: The page within the block of interest
472 * @pfn: The target page frame number
473 * @mask: mask of bits that the caller is interested in
475 * Return: pageblock_bits flags
477 static __always_inline
478 unsigned long __get_pfnblock_flags_mask(struct page
*page
,
482 unsigned long *bitmap
;
483 unsigned long bitidx
, word_bitidx
;
486 bitmap
= get_pageblock_bitmap(page
, pfn
);
487 bitidx
= pfn_to_bitidx(page
, pfn
);
488 word_bitidx
= bitidx
/ BITS_PER_LONG
;
489 bitidx
&= (BITS_PER_LONG
-1);
491 word
= bitmap
[word_bitidx
];
492 return (word
>> bitidx
) & mask
;
495 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
498 return __get_pfnblock_flags_mask(page
, pfn
, mask
);
501 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
503 return __get_pfnblock_flags_mask(page
, pfn
, MIGRATETYPE_MASK
);
507 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
508 * @page: The page within the block of interest
509 * @flags: The flags to set
510 * @pfn: The target page frame number
511 * @mask: mask of bits that the caller is interested in
513 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
517 unsigned long *bitmap
;
518 unsigned long bitidx
, word_bitidx
;
519 unsigned long old_word
, word
;
521 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
522 BUILD_BUG_ON(MIGRATE_TYPES
> (1 << PB_migratetype_bits
));
524 bitmap
= get_pageblock_bitmap(page
, pfn
);
525 bitidx
= pfn_to_bitidx(page
, pfn
);
526 word_bitidx
= bitidx
/ BITS_PER_LONG
;
527 bitidx
&= (BITS_PER_LONG
-1);
529 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
534 word
= READ_ONCE(bitmap
[word_bitidx
]);
536 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
537 if (word
== old_word
)
543 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
545 if (unlikely(page_group_by_mobility_disabled
&&
546 migratetype
< MIGRATE_PCPTYPES
))
547 migratetype
= MIGRATE_UNMOVABLE
;
549 set_pfnblock_flags_mask(page
, (unsigned long)migratetype
,
550 page_to_pfn(page
), MIGRATETYPE_MASK
);
553 #ifdef CONFIG_DEBUG_VM
554 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
558 unsigned long pfn
= page_to_pfn(page
);
559 unsigned long sp
, start_pfn
;
562 seq
= zone_span_seqbegin(zone
);
563 start_pfn
= zone
->zone_start_pfn
;
564 sp
= zone
->spanned_pages
;
565 if (!zone_spans_pfn(zone
, pfn
))
567 } while (zone_span_seqretry(zone
, seq
));
570 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
571 pfn
, zone_to_nid(zone
), zone
->name
,
572 start_pfn
, start_pfn
+ sp
);
577 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
579 if (!pfn_valid_within(page_to_pfn(page
)))
581 if (zone
!= page_zone(page
))
587 * Temporary debugging check for pages not lying within a given zone.
589 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
591 if (page_outside_zone_boundaries(zone
, page
))
593 if (!page_is_consistent(zone
, page
))
599 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
605 static void bad_page(struct page
*page
, const char *reason
)
607 static unsigned long resume
;
608 static unsigned long nr_shown
;
609 static unsigned long nr_unshown
;
612 * Allow a burst of 60 reports, then keep quiet for that minute;
613 * or allow a steady drip of one report per second.
615 if (nr_shown
== 60) {
616 if (time_before(jiffies
, resume
)) {
622 "BUG: Bad page state: %lu messages suppressed\n",
629 resume
= jiffies
+ 60 * HZ
;
631 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
632 current
->comm
, page_to_pfn(page
));
633 __dump_page(page
, reason
);
634 dump_page_owner(page
);
639 /* Leave bad fields for debug, except PageBuddy could make trouble */
640 page_mapcount_reset(page
); /* remove PageBuddy */
641 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
645 * Higher-order pages are called "compound pages". They are structured thusly:
647 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
649 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
650 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
652 * The first tail page's ->compound_dtor holds the offset in array of compound
653 * page destructors. See compound_page_dtors.
655 * The first tail page's ->compound_order holds the order of allocation.
656 * This usage means that zero-order pages may not be compound.
659 void free_compound_page(struct page
*page
)
661 mem_cgroup_uncharge(page
);
662 __free_pages_ok(page
, compound_order(page
));
665 void prep_compound_page(struct page
*page
, unsigned int order
)
668 int nr_pages
= 1 << order
;
671 for (i
= 1; i
< nr_pages
; i
++) {
672 struct page
*p
= page
+ i
;
673 set_page_count(p
, 0);
674 p
->mapping
= TAIL_MAPPING
;
675 set_compound_head(p
, page
);
678 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
679 set_compound_order(page
, order
);
680 atomic_set(compound_mapcount_ptr(page
), -1);
681 if (hpage_pincount_available(page
))
682 atomic_set(compound_pincount_ptr(page
), 0);
685 #ifdef CONFIG_DEBUG_PAGEALLOC
686 unsigned int _debug_guardpage_minorder
;
688 bool _debug_pagealloc_enabled_early __read_mostly
689 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
690 EXPORT_SYMBOL(_debug_pagealloc_enabled_early
);
691 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled
);
692 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
694 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled
);
696 static int __init
early_debug_pagealloc(char *buf
)
698 return kstrtobool(buf
, &_debug_pagealloc_enabled_early
);
700 early_param("debug_pagealloc", early_debug_pagealloc
);
702 void init_debug_pagealloc(void)
704 if (!debug_pagealloc_enabled())
707 static_branch_enable(&_debug_pagealloc_enabled
);
709 if (!debug_guardpage_minorder())
712 static_branch_enable(&_debug_guardpage_enabled
);
715 static int __init
debug_guardpage_minorder_setup(char *buf
)
719 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
720 pr_err("Bad debug_guardpage_minorder value\n");
723 _debug_guardpage_minorder
= res
;
724 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
727 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
729 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
730 unsigned int order
, int migratetype
)
732 if (!debug_guardpage_enabled())
735 if (order
>= debug_guardpage_minorder())
738 __SetPageGuard(page
);
739 INIT_LIST_HEAD(&page
->lru
);
740 set_page_private(page
, order
);
741 /* Guard pages are not available for any usage */
742 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
747 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
748 unsigned int order
, int migratetype
)
750 if (!debug_guardpage_enabled())
753 __ClearPageGuard(page
);
755 set_page_private(page
, 0);
756 if (!is_migrate_isolate(migratetype
))
757 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
760 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
761 unsigned int order
, int migratetype
) { return false; }
762 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
763 unsigned int order
, int migratetype
) {}
766 static inline void set_page_order(struct page
*page
, unsigned int order
)
768 set_page_private(page
, order
);
769 __SetPageBuddy(page
);
773 * This function checks whether a page is free && is the buddy
774 * we can coalesce a page and its buddy if
775 * (a) the buddy is not in a hole (check before calling!) &&
776 * (b) the buddy is in the buddy system &&
777 * (c) a page and its buddy have the same order &&
778 * (d) a page and its buddy are in the same zone.
780 * For recording whether a page is in the buddy system, we set PageBuddy.
781 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
783 * For recording page's order, we use page_private(page).
785 static inline bool page_is_buddy(struct page
*page
, struct page
*buddy
,
788 if (!page_is_guard(buddy
) && !PageBuddy(buddy
))
791 if (page_order(buddy
) != order
)
795 * zone check is done late to avoid uselessly calculating
796 * zone/node ids for pages that could never merge.
798 if (page_zone_id(page
) != page_zone_id(buddy
))
801 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
806 #ifdef CONFIG_COMPACTION
807 static inline struct capture_control
*task_capc(struct zone
*zone
)
809 struct capture_control
*capc
= current
->capture_control
;
811 return unlikely(capc
) &&
812 !(current
->flags
& PF_KTHREAD
) &&
814 capc
->cc
->zone
== zone
? capc
: NULL
;
818 compaction_capture(struct capture_control
*capc
, struct page
*page
,
819 int order
, int migratetype
)
821 if (!capc
|| order
!= capc
->cc
->order
)
824 /* Do not accidentally pollute CMA or isolated regions*/
825 if (is_migrate_cma(migratetype
) ||
826 is_migrate_isolate(migratetype
))
830 * Do not let lower order allocations polluate a movable pageblock.
831 * This might let an unmovable request use a reclaimable pageblock
832 * and vice-versa but no more than normal fallback logic which can
833 * have trouble finding a high-order free page.
835 if (order
< pageblock_order
&& migratetype
== MIGRATE_MOVABLE
)
843 static inline struct capture_control
*task_capc(struct zone
*zone
)
849 compaction_capture(struct capture_control
*capc
, struct page
*page
,
850 int order
, int migratetype
)
854 #endif /* CONFIG_COMPACTION */
856 /* Used for pages not on another list */
857 static inline void add_to_free_list(struct page
*page
, struct zone
*zone
,
858 unsigned int order
, int migratetype
)
860 struct free_area
*area
= &zone
->free_area
[order
];
862 list_add(&page
->lru
, &area
->free_list
[migratetype
]);
866 /* Used for pages not on another list */
867 static inline void add_to_free_list_tail(struct page
*page
, struct zone
*zone
,
868 unsigned int order
, int migratetype
)
870 struct free_area
*area
= &zone
->free_area
[order
];
872 list_add_tail(&page
->lru
, &area
->free_list
[migratetype
]);
876 /* Used for pages which are on another list */
877 static inline void move_to_free_list(struct page
*page
, struct zone
*zone
,
878 unsigned int order
, int migratetype
)
880 struct free_area
*area
= &zone
->free_area
[order
];
882 list_move(&page
->lru
, &area
->free_list
[migratetype
]);
885 static inline void del_page_from_free_list(struct page
*page
, struct zone
*zone
,
888 /* clear reported state and update reported page count */
889 if (page_reported(page
))
890 __ClearPageReported(page
);
892 list_del(&page
->lru
);
893 __ClearPageBuddy(page
);
894 set_page_private(page
, 0);
895 zone
->free_area
[order
].nr_free
--;
899 * If this is not the largest possible page, check if the buddy
900 * of the next-highest order is free. If it is, it's possible
901 * that pages are being freed that will coalesce soon. In case,
902 * that is happening, add the free page to the tail of the list
903 * so it's less likely to be used soon and more likely to be merged
904 * as a higher order page
907 buddy_merge_likely(unsigned long pfn
, unsigned long buddy_pfn
,
908 struct page
*page
, unsigned int order
)
910 struct page
*higher_page
, *higher_buddy
;
911 unsigned long combined_pfn
;
913 if (order
>= MAX_ORDER
- 2)
916 if (!pfn_valid_within(buddy_pfn
))
919 combined_pfn
= buddy_pfn
& pfn
;
920 higher_page
= page
+ (combined_pfn
- pfn
);
921 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
922 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
924 return pfn_valid_within(buddy_pfn
) &&
925 page_is_buddy(higher_page
, higher_buddy
, order
+ 1);
929 * Freeing function for a buddy system allocator.
931 * The concept of a buddy system is to maintain direct-mapped table
932 * (containing bit values) for memory blocks of various "orders".
933 * The bottom level table contains the map for the smallest allocatable
934 * units of memory (here, pages), and each level above it describes
935 * pairs of units from the levels below, hence, "buddies".
936 * At a high level, all that happens here is marking the table entry
937 * at the bottom level available, and propagating the changes upward
938 * as necessary, plus some accounting needed to play nicely with other
939 * parts of the VM system.
940 * At each level, we keep a list of pages, which are heads of continuous
941 * free pages of length of (1 << order) and marked with PageBuddy.
942 * Page's order is recorded in page_private(page) field.
943 * So when we are allocating or freeing one, we can derive the state of the
944 * other. That is, if we allocate a small block, and both were
945 * free, the remainder of the region must be split into blocks.
946 * If a block is freed, and its buddy is also free, then this
947 * triggers coalescing into a block of larger size.
952 static inline void __free_one_page(struct page
*page
,
954 struct zone
*zone
, unsigned int order
,
955 int migratetype
, bool report
)
957 struct capture_control
*capc
= task_capc(zone
);
958 unsigned long buddy_pfn
;
959 unsigned long combined_pfn
;
960 unsigned int max_order
;
964 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
966 VM_BUG_ON(!zone_is_initialized(zone
));
967 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
969 VM_BUG_ON(migratetype
== -1);
970 if (likely(!is_migrate_isolate(migratetype
)))
971 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
973 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
974 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
977 while (order
< max_order
- 1) {
978 if (compaction_capture(capc
, page
, order
, migratetype
)) {
979 __mod_zone_freepage_state(zone
, -(1 << order
),
983 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
984 buddy
= page
+ (buddy_pfn
- pfn
);
986 if (!pfn_valid_within(buddy_pfn
))
988 if (!page_is_buddy(page
, buddy
, order
))
991 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
992 * merge with it and move up one order.
994 if (page_is_guard(buddy
))
995 clear_page_guard(zone
, buddy
, order
, migratetype
);
997 del_page_from_free_list(buddy
, zone
, order
);
998 combined_pfn
= buddy_pfn
& pfn
;
999 page
= page
+ (combined_pfn
- pfn
);
1003 if (max_order
< MAX_ORDER
) {
1004 /* If we are here, it means order is >= pageblock_order.
1005 * We want to prevent merge between freepages on isolate
1006 * pageblock and normal pageblock. Without this, pageblock
1007 * isolation could cause incorrect freepage or CMA accounting.
1009 * We don't want to hit this code for the more frequent
1010 * low-order merging.
1012 if (unlikely(has_isolate_pageblock(zone
))) {
1015 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1016 buddy
= page
+ (buddy_pfn
- pfn
);
1017 buddy_mt
= get_pageblock_migratetype(buddy
);
1019 if (migratetype
!= buddy_mt
1020 && (is_migrate_isolate(migratetype
) ||
1021 is_migrate_isolate(buddy_mt
)))
1025 goto continue_merging
;
1029 set_page_order(page
, order
);
1031 if (is_shuffle_order(order
))
1032 to_tail
= shuffle_pick_tail();
1034 to_tail
= buddy_merge_likely(pfn
, buddy_pfn
, page
, order
);
1037 add_to_free_list_tail(page
, zone
, order
, migratetype
);
1039 add_to_free_list(page
, zone
, order
, migratetype
);
1041 /* Notify page reporting subsystem of freed page */
1043 page_reporting_notify_free(order
);
1047 * A bad page could be due to a number of fields. Instead of multiple branches,
1048 * try and check multiple fields with one check. The caller must do a detailed
1049 * check if necessary.
1051 static inline bool page_expected_state(struct page
*page
,
1052 unsigned long check_flags
)
1054 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1057 if (unlikely((unsigned long)page
->mapping
|
1058 page_ref_count(page
) |
1060 (unsigned long)page
->mem_cgroup
|
1062 (page
->flags
& check_flags
)))
1068 static const char *page_bad_reason(struct page
*page
, unsigned long flags
)
1070 const char *bad_reason
= NULL
;
1072 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1073 bad_reason
= "nonzero mapcount";
1074 if (unlikely(page
->mapping
!= NULL
))
1075 bad_reason
= "non-NULL mapping";
1076 if (unlikely(page_ref_count(page
) != 0))
1077 bad_reason
= "nonzero _refcount";
1078 if (unlikely(page
->flags
& flags
)) {
1079 if (flags
== PAGE_FLAGS_CHECK_AT_PREP
)
1080 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1082 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1085 if (unlikely(page
->mem_cgroup
))
1086 bad_reason
= "page still charged to cgroup";
1091 static void check_free_page_bad(struct page
*page
)
1094 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_FREE
));
1097 static inline int check_free_page(struct page
*page
)
1099 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
1102 /* Something has gone sideways, find it */
1103 check_free_page_bad(page
);
1107 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
1112 * We rely page->lru.next never has bit 0 set, unless the page
1113 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1115 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
1117 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
1121 switch (page
- head_page
) {
1123 /* the first tail page: ->mapping may be compound_mapcount() */
1124 if (unlikely(compound_mapcount(page
))) {
1125 bad_page(page
, "nonzero compound_mapcount");
1131 * the second tail page: ->mapping is
1132 * deferred_list.next -- ignore value.
1136 if (page
->mapping
!= TAIL_MAPPING
) {
1137 bad_page(page
, "corrupted mapping in tail page");
1142 if (unlikely(!PageTail(page
))) {
1143 bad_page(page
, "PageTail not set");
1146 if (unlikely(compound_head(page
) != head_page
)) {
1147 bad_page(page
, "compound_head not consistent");
1152 page
->mapping
= NULL
;
1153 clear_compound_head(page
);
1157 static void kernel_init_free_pages(struct page
*page
, int numpages
)
1161 /* s390's use of memset() could override KASAN redzones. */
1162 kasan_disable_current();
1163 for (i
= 0; i
< numpages
; i
++)
1164 clear_highpage(page
+ i
);
1165 kasan_enable_current();
1168 static __always_inline
bool free_pages_prepare(struct page
*page
,
1169 unsigned int order
, bool check_free
)
1173 VM_BUG_ON_PAGE(PageTail(page
), page
);
1175 trace_mm_page_free(page
, order
);
1178 * Check tail pages before head page information is cleared to
1179 * avoid checking PageCompound for order-0 pages.
1181 if (unlikely(order
)) {
1182 bool compound
= PageCompound(page
);
1185 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1188 ClearPageDoubleMap(page
);
1189 for (i
= 1; i
< (1 << order
); i
++) {
1191 bad
+= free_tail_pages_check(page
, page
+ i
);
1192 if (unlikely(check_free_page(page
+ i
))) {
1196 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1199 if (PageMappingFlags(page
))
1200 page
->mapping
= NULL
;
1201 if (memcg_kmem_enabled() && PageKmemcg(page
))
1202 __memcg_kmem_uncharge_page(page
, order
);
1204 bad
+= check_free_page(page
);
1208 page_cpupid_reset_last(page
);
1209 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1210 reset_page_owner(page
, order
);
1212 if (!PageHighMem(page
)) {
1213 debug_check_no_locks_freed(page_address(page
),
1214 PAGE_SIZE
<< order
);
1215 debug_check_no_obj_freed(page_address(page
),
1216 PAGE_SIZE
<< order
);
1218 if (want_init_on_free())
1219 kernel_init_free_pages(page
, 1 << order
);
1221 kernel_poison_pages(page
, 1 << order
, 0);
1223 * arch_free_page() can make the page's contents inaccessible. s390
1224 * does this. So nothing which can access the page's contents should
1225 * happen after this.
1227 arch_free_page(page
, order
);
1229 if (debug_pagealloc_enabled_static())
1230 kernel_map_pages(page
, 1 << order
, 0);
1232 kasan_free_nondeferred_pages(page
, order
);
1237 #ifdef CONFIG_DEBUG_VM
1239 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1240 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1241 * moved from pcp lists to free lists.
1243 static bool free_pcp_prepare(struct page
*page
)
1245 return free_pages_prepare(page
, 0, true);
1248 static bool bulkfree_pcp_prepare(struct page
*page
)
1250 if (debug_pagealloc_enabled_static())
1251 return check_free_page(page
);
1257 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1258 * moving from pcp lists to free list in order to reduce overhead. With
1259 * debug_pagealloc enabled, they are checked also immediately when being freed
1262 static bool free_pcp_prepare(struct page
*page
)
1264 if (debug_pagealloc_enabled_static())
1265 return free_pages_prepare(page
, 0, true);
1267 return free_pages_prepare(page
, 0, false);
1270 static bool bulkfree_pcp_prepare(struct page
*page
)
1272 return check_free_page(page
);
1274 #endif /* CONFIG_DEBUG_VM */
1276 static inline void prefetch_buddy(struct page
*page
)
1278 unsigned long pfn
= page_to_pfn(page
);
1279 unsigned long buddy_pfn
= __find_buddy_pfn(pfn
, 0);
1280 struct page
*buddy
= page
+ (buddy_pfn
- pfn
);
1286 * Frees a number of pages from the PCP lists
1287 * Assumes all pages on list are in same zone, and of same order.
1288 * count is the number of pages to free.
1290 * If the zone was previously in an "all pages pinned" state then look to
1291 * see if this freeing clears that state.
1293 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1294 * pinned" detection logic.
1296 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1297 struct per_cpu_pages
*pcp
)
1299 int migratetype
= 0;
1301 int prefetch_nr
= 0;
1302 bool isolated_pageblocks
;
1303 struct page
*page
, *tmp
;
1307 * Ensure proper count is passed which otherwise would stuck in the
1308 * below while (list_empty(list)) loop.
1310 count
= min(pcp
->count
, count
);
1312 struct list_head
*list
;
1315 * Remove pages from lists in a round-robin fashion. A
1316 * batch_free count is maintained that is incremented when an
1317 * empty list is encountered. This is so more pages are freed
1318 * off fuller lists instead of spinning excessively around empty
1323 if (++migratetype
== MIGRATE_PCPTYPES
)
1325 list
= &pcp
->lists
[migratetype
];
1326 } while (list_empty(list
));
1328 /* This is the only non-empty list. Free them all. */
1329 if (batch_free
== MIGRATE_PCPTYPES
)
1333 page
= list_last_entry(list
, struct page
, lru
);
1334 /* must delete to avoid corrupting pcp list */
1335 list_del(&page
->lru
);
1338 if (bulkfree_pcp_prepare(page
))
1341 list_add_tail(&page
->lru
, &head
);
1344 * We are going to put the page back to the global
1345 * pool, prefetch its buddy to speed up later access
1346 * under zone->lock. It is believed the overhead of
1347 * an additional test and calculating buddy_pfn here
1348 * can be offset by reduced memory latency later. To
1349 * avoid excessive prefetching due to large count, only
1350 * prefetch buddy for the first pcp->batch nr of pages.
1352 if (prefetch_nr
++ < pcp
->batch
)
1353 prefetch_buddy(page
);
1354 } while (--count
&& --batch_free
&& !list_empty(list
));
1357 spin_lock(&zone
->lock
);
1358 isolated_pageblocks
= has_isolate_pageblock(zone
);
1361 * Use safe version since after __free_one_page(),
1362 * page->lru.next will not point to original list.
1364 list_for_each_entry_safe(page
, tmp
, &head
, lru
) {
1365 int mt
= get_pcppage_migratetype(page
);
1366 /* MIGRATE_ISOLATE page should not go to pcplists */
1367 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1368 /* Pageblock could have been isolated meanwhile */
1369 if (unlikely(isolated_pageblocks
))
1370 mt
= get_pageblock_migratetype(page
);
1372 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
, true);
1373 trace_mm_page_pcpu_drain(page
, 0, mt
);
1375 spin_unlock(&zone
->lock
);
1378 static void free_one_page(struct zone
*zone
,
1379 struct page
*page
, unsigned long pfn
,
1383 spin_lock(&zone
->lock
);
1384 if (unlikely(has_isolate_pageblock(zone
) ||
1385 is_migrate_isolate(migratetype
))) {
1386 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1388 __free_one_page(page
, pfn
, zone
, order
, migratetype
, true);
1389 spin_unlock(&zone
->lock
);
1392 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1393 unsigned long zone
, int nid
)
1395 mm_zero_struct_page(page
);
1396 set_page_links(page
, zone
, nid
, pfn
);
1397 init_page_count(page
);
1398 page_mapcount_reset(page
);
1399 page_cpupid_reset_last(page
);
1400 page_kasan_tag_reset(page
);
1402 INIT_LIST_HEAD(&page
->lru
);
1403 #ifdef WANT_PAGE_VIRTUAL
1404 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1405 if (!is_highmem_idx(zone
))
1406 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1410 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1411 static void __meminit
init_reserved_page(unsigned long pfn
)
1416 if (!early_page_uninitialised(pfn
))
1419 nid
= early_pfn_to_nid(pfn
);
1420 pgdat
= NODE_DATA(nid
);
1422 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1423 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1425 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1428 __init_single_page(pfn_to_page(pfn
), pfn
, zid
, nid
);
1431 static inline void init_reserved_page(unsigned long pfn
)
1434 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1437 * Initialised pages do not have PageReserved set. This function is
1438 * called for each range allocated by the bootmem allocator and
1439 * marks the pages PageReserved. The remaining valid pages are later
1440 * sent to the buddy page allocator.
1442 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1444 unsigned long start_pfn
= PFN_DOWN(start
);
1445 unsigned long end_pfn
= PFN_UP(end
);
1447 for (; start_pfn
< end_pfn
; start_pfn
++) {
1448 if (pfn_valid(start_pfn
)) {
1449 struct page
*page
= pfn_to_page(start_pfn
);
1451 init_reserved_page(start_pfn
);
1453 /* Avoid false-positive PageTail() */
1454 INIT_LIST_HEAD(&page
->lru
);
1457 * no need for atomic set_bit because the struct
1458 * page is not visible yet so nobody should
1461 __SetPageReserved(page
);
1466 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1468 unsigned long flags
;
1470 unsigned long pfn
= page_to_pfn(page
);
1472 if (!free_pages_prepare(page
, order
, true))
1475 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1476 local_irq_save(flags
);
1477 __count_vm_events(PGFREE
, 1 << order
);
1478 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1479 local_irq_restore(flags
);
1482 void __free_pages_core(struct page
*page
, unsigned int order
)
1484 unsigned int nr_pages
= 1 << order
;
1485 struct page
*p
= page
;
1489 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1491 __ClearPageReserved(p
);
1492 set_page_count(p
, 0);
1494 __ClearPageReserved(p
);
1495 set_page_count(p
, 0);
1497 atomic_long_add(nr_pages
, &page_zone(page
)->managed_pages
);
1498 set_page_refcounted(page
);
1499 __free_pages(page
, order
);
1502 #ifdef CONFIG_NEED_MULTIPLE_NODES
1504 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1506 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1509 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1511 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
1512 struct mminit_pfnnid_cache
*state
)
1514 unsigned long start_pfn
, end_pfn
;
1517 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
1518 return state
->last_nid
;
1520 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
1521 if (nid
!= NUMA_NO_NODE
) {
1522 state
->last_start
= start_pfn
;
1523 state
->last_end
= end_pfn
;
1524 state
->last_nid
= nid
;
1529 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1531 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1533 static DEFINE_SPINLOCK(early_pfn_lock
);
1536 spin_lock(&early_pfn_lock
);
1537 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1539 nid
= first_online_node
;
1540 spin_unlock(&early_pfn_lock
);
1544 #endif /* CONFIG_NEED_MULTIPLE_NODES */
1546 void __init
memblock_free_pages(struct page
*page
, unsigned long pfn
,
1549 if (early_page_uninitialised(pfn
))
1551 __free_pages_core(page
, order
);
1555 * Check that the whole (or subset of) a pageblock given by the interval of
1556 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1557 * with the migration of free compaction scanner. The scanners then need to
1558 * use only pfn_valid_within() check for arches that allow holes within
1561 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1563 * It's possible on some configurations to have a setup like node0 node1 node0
1564 * i.e. it's possible that all pages within a zones range of pages do not
1565 * belong to a single zone. We assume that a border between node0 and node1
1566 * can occur within a single pageblock, but not a node0 node1 node0
1567 * interleaving within a single pageblock. It is therefore sufficient to check
1568 * the first and last page of a pageblock and avoid checking each individual
1569 * page in a pageblock.
1571 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1572 unsigned long end_pfn
, struct zone
*zone
)
1574 struct page
*start_page
;
1575 struct page
*end_page
;
1577 /* end_pfn is one past the range we are checking */
1580 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1583 start_page
= pfn_to_online_page(start_pfn
);
1587 if (page_zone(start_page
) != zone
)
1590 end_page
= pfn_to_page(end_pfn
);
1592 /* This gives a shorter code than deriving page_zone(end_page) */
1593 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1599 void set_zone_contiguous(struct zone
*zone
)
1601 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1602 unsigned long block_end_pfn
;
1604 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1605 for (; block_start_pfn
< zone_end_pfn(zone
);
1606 block_start_pfn
= block_end_pfn
,
1607 block_end_pfn
+= pageblock_nr_pages
) {
1609 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1611 if (!__pageblock_pfn_to_page(block_start_pfn
,
1612 block_end_pfn
, zone
))
1617 /* We confirm that there is no hole */
1618 zone
->contiguous
= true;
1621 void clear_zone_contiguous(struct zone
*zone
)
1623 zone
->contiguous
= false;
1626 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1627 static void __init
deferred_free_range(unsigned long pfn
,
1628 unsigned long nr_pages
)
1636 page
= pfn_to_page(pfn
);
1638 /* Free a large naturally-aligned chunk if possible */
1639 if (nr_pages
== pageblock_nr_pages
&&
1640 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1641 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1642 __free_pages_core(page
, pageblock_order
);
1646 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1647 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1648 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1649 __free_pages_core(page
, 0);
1653 /* Completion tracking for deferred_init_memmap() threads */
1654 static atomic_t pgdat_init_n_undone __initdata
;
1655 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1657 static inline void __init
pgdat_init_report_one_done(void)
1659 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1660 complete(&pgdat_init_all_done_comp
);
1664 * Returns true if page needs to be initialized or freed to buddy allocator.
1666 * First we check if pfn is valid on architectures where it is possible to have
1667 * holes within pageblock_nr_pages. On systems where it is not possible, this
1668 * function is optimized out.
1670 * Then, we check if a current large page is valid by only checking the validity
1673 static inline bool __init
deferred_pfn_valid(unsigned long pfn
)
1675 if (!pfn_valid_within(pfn
))
1677 if (!(pfn
& (pageblock_nr_pages
- 1)) && !pfn_valid(pfn
))
1683 * Free pages to buddy allocator. Try to free aligned pages in
1684 * pageblock_nr_pages sizes.
1686 static void __init
deferred_free_pages(unsigned long pfn
,
1687 unsigned long end_pfn
)
1689 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1690 unsigned long nr_free
= 0;
1692 for (; pfn
< end_pfn
; pfn
++) {
1693 if (!deferred_pfn_valid(pfn
)) {
1694 deferred_free_range(pfn
- nr_free
, nr_free
);
1696 } else if (!(pfn
& nr_pgmask
)) {
1697 deferred_free_range(pfn
- nr_free
, nr_free
);
1703 /* Free the last block of pages to allocator */
1704 deferred_free_range(pfn
- nr_free
, nr_free
);
1708 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1709 * by performing it only once every pageblock_nr_pages.
1710 * Return number of pages initialized.
1712 static unsigned long __init
deferred_init_pages(struct zone
*zone
,
1714 unsigned long end_pfn
)
1716 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1717 int nid
= zone_to_nid(zone
);
1718 unsigned long nr_pages
= 0;
1719 int zid
= zone_idx(zone
);
1720 struct page
*page
= NULL
;
1722 for (; pfn
< end_pfn
; pfn
++) {
1723 if (!deferred_pfn_valid(pfn
)) {
1726 } else if (!page
|| !(pfn
& nr_pgmask
)) {
1727 page
= pfn_to_page(pfn
);
1731 __init_single_page(page
, pfn
, zid
, nid
);
1738 * This function is meant to pre-load the iterator for the zone init.
1739 * Specifically it walks through the ranges until we are caught up to the
1740 * first_init_pfn value and exits there. If we never encounter the value we
1741 * return false indicating there are no valid ranges left.
1744 deferred_init_mem_pfn_range_in_zone(u64
*i
, struct zone
*zone
,
1745 unsigned long *spfn
, unsigned long *epfn
,
1746 unsigned long first_init_pfn
)
1751 * Start out by walking through the ranges in this zone that have
1752 * already been initialized. We don't need to do anything with them
1753 * so we just need to flush them out of the system.
1755 for_each_free_mem_pfn_range_in_zone(j
, zone
, spfn
, epfn
) {
1756 if (*epfn
<= first_init_pfn
)
1758 if (*spfn
< first_init_pfn
)
1759 *spfn
= first_init_pfn
;
1768 * Initialize and free pages. We do it in two loops: first we initialize
1769 * struct page, then free to buddy allocator, because while we are
1770 * freeing pages we can access pages that are ahead (computing buddy
1771 * page in __free_one_page()).
1773 * In order to try and keep some memory in the cache we have the loop
1774 * broken along max page order boundaries. This way we will not cause
1775 * any issues with the buddy page computation.
1777 static unsigned long __init
1778 deferred_init_maxorder(u64
*i
, struct zone
*zone
, unsigned long *start_pfn
,
1779 unsigned long *end_pfn
)
1781 unsigned long mo_pfn
= ALIGN(*start_pfn
+ 1, MAX_ORDER_NR_PAGES
);
1782 unsigned long spfn
= *start_pfn
, epfn
= *end_pfn
;
1783 unsigned long nr_pages
= 0;
1786 /* First we loop through and initialize the page values */
1787 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, start_pfn
, end_pfn
) {
1790 if (mo_pfn
<= *start_pfn
)
1793 t
= min(mo_pfn
, *end_pfn
);
1794 nr_pages
+= deferred_init_pages(zone
, *start_pfn
, t
);
1796 if (mo_pfn
< *end_pfn
) {
1797 *start_pfn
= mo_pfn
;
1802 /* Reset values and now loop through freeing pages as needed */
1805 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, &spfn
, &epfn
) {
1811 t
= min(mo_pfn
, epfn
);
1812 deferred_free_pages(spfn
, t
);
1822 deferred_init_memmap_chunk(unsigned long start_pfn
, unsigned long end_pfn
,
1825 unsigned long spfn
, epfn
;
1826 struct zone
*zone
= arg
;
1829 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
, start_pfn
);
1832 * Initialize and free pages in MAX_ORDER sized increments so that we
1833 * can avoid introducing any issues with the buddy allocator.
1835 while (spfn
< end_pfn
) {
1836 deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1841 /* An arch may override for more concurrency. */
1843 deferred_page_init_max_threads(const struct cpumask
*node_cpumask
)
1848 /* Initialise remaining memory on a node */
1849 static int __init
deferred_init_memmap(void *data
)
1851 pg_data_t
*pgdat
= data
;
1852 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1853 unsigned long spfn
= 0, epfn
= 0;
1854 unsigned long first_init_pfn
, flags
;
1855 unsigned long start
= jiffies
;
1857 int zid
, max_threads
;
1860 /* Bind memory initialisation thread to a local node if possible */
1861 if (!cpumask_empty(cpumask
))
1862 set_cpus_allowed_ptr(current
, cpumask
);
1864 pgdat_resize_lock(pgdat
, &flags
);
1865 first_init_pfn
= pgdat
->first_deferred_pfn
;
1866 if (first_init_pfn
== ULONG_MAX
) {
1867 pgdat_resize_unlock(pgdat
, &flags
);
1868 pgdat_init_report_one_done();
1872 /* Sanity check boundaries */
1873 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1874 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1875 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1878 * Once we unlock here, the zone cannot be grown anymore, thus if an
1879 * interrupt thread must allocate this early in boot, zone must be
1880 * pre-grown prior to start of deferred page initialization.
1882 pgdat_resize_unlock(pgdat
, &flags
);
1884 /* Only the highest zone is deferred so find it */
1885 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1886 zone
= pgdat
->node_zones
+ zid
;
1887 if (first_init_pfn
< zone_end_pfn(zone
))
1891 /* If the zone is empty somebody else may have cleared out the zone */
1892 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1896 max_threads
= deferred_page_init_max_threads(cpumask
);
1898 while (spfn
< epfn
) {
1899 unsigned long epfn_align
= ALIGN(epfn
, PAGES_PER_SECTION
);
1900 struct padata_mt_job job
= {
1901 .thread_fn
= deferred_init_memmap_chunk
,
1904 .size
= epfn_align
- spfn
,
1905 .align
= PAGES_PER_SECTION
,
1906 .min_chunk
= PAGES_PER_SECTION
,
1907 .max_threads
= max_threads
,
1910 padata_do_multithreaded(&job
);
1911 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1915 /* Sanity check that the next zone really is unpopulated */
1916 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1918 pr_info("node %d deferred pages initialised in %ums\n",
1919 pgdat
->node_id
, jiffies_to_msecs(jiffies
- start
));
1921 pgdat_init_report_one_done();
1926 * If this zone has deferred pages, try to grow it by initializing enough
1927 * deferred pages to satisfy the allocation specified by order, rounded up to
1928 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1929 * of SECTION_SIZE bytes by initializing struct pages in increments of
1930 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1932 * Return true when zone was grown, otherwise return false. We return true even
1933 * when we grow less than requested, to let the caller decide if there are
1934 * enough pages to satisfy the allocation.
1936 * Note: We use noinline because this function is needed only during boot, and
1937 * it is called from a __ref function _deferred_grow_zone. This way we are
1938 * making sure that it is not inlined into permanent text section.
1940 static noinline
bool __init
1941 deferred_grow_zone(struct zone
*zone
, unsigned int order
)
1943 unsigned long nr_pages_needed
= ALIGN(1 << order
, PAGES_PER_SECTION
);
1944 pg_data_t
*pgdat
= zone
->zone_pgdat
;
1945 unsigned long first_deferred_pfn
= pgdat
->first_deferred_pfn
;
1946 unsigned long spfn
, epfn
, flags
;
1947 unsigned long nr_pages
= 0;
1950 /* Only the last zone may have deferred pages */
1951 if (zone_end_pfn(zone
) != pgdat_end_pfn(pgdat
))
1954 pgdat_resize_lock(pgdat
, &flags
);
1957 * If someone grew this zone while we were waiting for spinlock, return
1958 * true, as there might be enough pages already.
1960 if (first_deferred_pfn
!= pgdat
->first_deferred_pfn
) {
1961 pgdat_resize_unlock(pgdat
, &flags
);
1965 /* If the zone is empty somebody else may have cleared out the zone */
1966 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1967 first_deferred_pfn
)) {
1968 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1969 pgdat_resize_unlock(pgdat
, &flags
);
1970 /* Retry only once. */
1971 return first_deferred_pfn
!= ULONG_MAX
;
1975 * Initialize and free pages in MAX_ORDER sized increments so
1976 * that we can avoid introducing any issues with the buddy
1979 while (spfn
< epfn
) {
1980 /* update our first deferred PFN for this section */
1981 first_deferred_pfn
= spfn
;
1983 nr_pages
+= deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1984 touch_nmi_watchdog();
1986 /* We should only stop along section boundaries */
1987 if ((first_deferred_pfn
^ spfn
) < PAGES_PER_SECTION
)
1990 /* If our quota has been met we can stop here */
1991 if (nr_pages
>= nr_pages_needed
)
1995 pgdat
->first_deferred_pfn
= spfn
;
1996 pgdat_resize_unlock(pgdat
, &flags
);
1998 return nr_pages
> 0;
2002 * deferred_grow_zone() is __init, but it is called from
2003 * get_page_from_freelist() during early boot until deferred_pages permanently
2004 * disables this call. This is why we have refdata wrapper to avoid warning,
2005 * and to ensure that the function body gets unloaded.
2008 _deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2010 return deferred_grow_zone(zone
, order
);
2013 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2015 void __init
page_alloc_init_late(void)
2020 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2022 /* There will be num_node_state(N_MEMORY) threads */
2023 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
2024 for_each_node_state(nid
, N_MEMORY
) {
2025 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
2028 /* Block until all are initialised */
2029 wait_for_completion(&pgdat_init_all_done_comp
);
2032 * The number of managed pages has changed due to the initialisation
2033 * so the pcpu batch and high limits needs to be updated or the limits
2034 * will be artificially small.
2036 for_each_populated_zone(zone
)
2037 zone_pcp_update(zone
);
2040 * We initialized the rest of the deferred pages. Permanently disable
2041 * on-demand struct page initialization.
2043 static_branch_disable(&deferred_pages
);
2045 /* Reinit limits that are based on free pages after the kernel is up */
2046 files_maxfiles_init();
2049 /* Discard memblock private memory */
2052 for_each_node_state(nid
, N_MEMORY
)
2053 shuffle_free_memory(NODE_DATA(nid
));
2055 for_each_populated_zone(zone
)
2056 set_zone_contiguous(zone
);
2060 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2061 void __init
init_cma_reserved_pageblock(struct page
*page
)
2063 unsigned i
= pageblock_nr_pages
;
2064 struct page
*p
= page
;
2067 __ClearPageReserved(p
);
2068 set_page_count(p
, 0);
2071 set_pageblock_migratetype(page
, MIGRATE_CMA
);
2073 if (pageblock_order
>= MAX_ORDER
) {
2074 i
= pageblock_nr_pages
;
2077 set_page_refcounted(p
);
2078 __free_pages(p
, MAX_ORDER
- 1);
2079 p
+= MAX_ORDER_NR_PAGES
;
2080 } while (i
-= MAX_ORDER_NR_PAGES
);
2082 set_page_refcounted(page
);
2083 __free_pages(page
, pageblock_order
);
2086 adjust_managed_page_count(page
, pageblock_nr_pages
);
2091 * The order of subdivision here is critical for the IO subsystem.
2092 * Please do not alter this order without good reasons and regression
2093 * testing. Specifically, as large blocks of memory are subdivided,
2094 * the order in which smaller blocks are delivered depends on the order
2095 * they're subdivided in this function. This is the primary factor
2096 * influencing the order in which pages are delivered to the IO
2097 * subsystem according to empirical testing, and this is also justified
2098 * by considering the behavior of a buddy system containing a single
2099 * large block of memory acted on by a series of small allocations.
2100 * This behavior is a critical factor in sglist merging's success.
2104 static inline void expand(struct zone
*zone
, struct page
*page
,
2105 int low
, int high
, int migratetype
)
2107 unsigned long size
= 1 << high
;
2109 while (high
> low
) {
2112 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
2115 * Mark as guard pages (or page), that will allow to
2116 * merge back to allocator when buddy will be freed.
2117 * Corresponding page table entries will not be touched,
2118 * pages will stay not present in virtual address space
2120 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
2123 add_to_free_list(&page
[size
], zone
, high
, migratetype
);
2124 set_page_order(&page
[size
], high
);
2128 static void check_new_page_bad(struct page
*page
)
2130 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
2131 /* Don't complain about hwpoisoned pages */
2132 page_mapcount_reset(page
); /* remove PageBuddy */
2137 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_PREP
));
2141 * This page is about to be returned from the page allocator
2143 static inline int check_new_page(struct page
*page
)
2145 if (likely(page_expected_state(page
,
2146 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
2149 check_new_page_bad(page
);
2153 static inline bool free_pages_prezeroed(void)
2155 return (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
2156 page_poisoning_enabled()) || want_init_on_free();
2159 #ifdef CONFIG_DEBUG_VM
2161 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2162 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2163 * also checked when pcp lists are refilled from the free lists.
2165 static inline bool check_pcp_refill(struct page
*page
)
2167 if (debug_pagealloc_enabled_static())
2168 return check_new_page(page
);
2173 static inline bool check_new_pcp(struct page
*page
)
2175 return check_new_page(page
);
2179 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2180 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2181 * enabled, they are also checked when being allocated from the pcp lists.
2183 static inline bool check_pcp_refill(struct page
*page
)
2185 return check_new_page(page
);
2187 static inline bool check_new_pcp(struct page
*page
)
2189 if (debug_pagealloc_enabled_static())
2190 return check_new_page(page
);
2194 #endif /* CONFIG_DEBUG_VM */
2196 static bool check_new_pages(struct page
*page
, unsigned int order
)
2199 for (i
= 0; i
< (1 << order
); i
++) {
2200 struct page
*p
= page
+ i
;
2202 if (unlikely(check_new_page(p
)))
2209 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
2212 set_page_private(page
, 0);
2213 set_page_refcounted(page
);
2215 arch_alloc_page(page
, order
);
2216 if (debug_pagealloc_enabled_static())
2217 kernel_map_pages(page
, 1 << order
, 1);
2218 kasan_alloc_pages(page
, order
);
2219 kernel_poison_pages(page
, 1 << order
, 1);
2220 set_page_owner(page
, order
, gfp_flags
);
2223 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
2224 unsigned int alloc_flags
)
2226 post_alloc_hook(page
, order
, gfp_flags
);
2228 if (!free_pages_prezeroed() && want_init_on_alloc(gfp_flags
))
2229 kernel_init_free_pages(page
, 1 << order
);
2231 if (order
&& (gfp_flags
& __GFP_COMP
))
2232 prep_compound_page(page
, order
);
2235 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2236 * allocate the page. The expectation is that the caller is taking
2237 * steps that will free more memory. The caller should avoid the page
2238 * being used for !PFMEMALLOC purposes.
2240 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2241 set_page_pfmemalloc(page
);
2243 clear_page_pfmemalloc(page
);
2247 * Go through the free lists for the given migratetype and remove
2248 * the smallest available page from the freelists
2250 static __always_inline
2251 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
2254 unsigned int current_order
;
2255 struct free_area
*area
;
2258 /* Find a page of the appropriate size in the preferred list */
2259 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
2260 area
= &(zone
->free_area
[current_order
]);
2261 page
= get_page_from_free_area(area
, migratetype
);
2264 del_page_from_free_list(page
, zone
, current_order
);
2265 expand(zone
, page
, order
, current_order
, migratetype
);
2266 set_pcppage_migratetype(page
, migratetype
);
2275 * This array describes the order lists are fallen back to when
2276 * the free lists for the desirable migrate type are depleted
2278 static int fallbacks
[MIGRATE_TYPES
][3] = {
2279 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2280 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
2281 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2283 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
2285 #ifdef CONFIG_MEMORY_ISOLATION
2286 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
2291 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2294 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
2297 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2298 unsigned int order
) { return NULL
; }
2302 * Move the free pages in a range to the free lists of the requested type.
2303 * Note that start_page and end_pages are not aligned on a pageblock
2304 * boundary. If alignment is required, use move_freepages_block()
2306 static int move_freepages(struct zone
*zone
,
2307 struct page
*start_page
, struct page
*end_page
,
2308 int migratetype
, int *num_movable
)
2312 int pages_moved
= 0;
2314 for (page
= start_page
; page
<= end_page
;) {
2315 if (!pfn_valid_within(page_to_pfn(page
))) {
2320 if (!PageBuddy(page
)) {
2322 * We assume that pages that could be isolated for
2323 * migration are movable. But we don't actually try
2324 * isolating, as that would be expensive.
2327 (PageLRU(page
) || __PageMovable(page
)))
2334 /* Make sure we are not inadvertently changing nodes */
2335 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
2336 VM_BUG_ON_PAGE(page_zone(page
) != zone
, page
);
2338 order
= page_order(page
);
2339 move_to_free_list(page
, zone
, order
, migratetype
);
2341 pages_moved
+= 1 << order
;
2347 int move_freepages_block(struct zone
*zone
, struct page
*page
,
2348 int migratetype
, int *num_movable
)
2350 unsigned long start_pfn
, end_pfn
;
2351 struct page
*start_page
, *end_page
;
2356 start_pfn
= page_to_pfn(page
);
2357 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
2358 start_page
= pfn_to_page(start_pfn
);
2359 end_page
= start_page
+ pageblock_nr_pages
- 1;
2360 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
2362 /* Do not cross zone boundaries */
2363 if (!zone_spans_pfn(zone
, start_pfn
))
2365 if (!zone_spans_pfn(zone
, end_pfn
))
2368 return move_freepages(zone
, start_page
, end_page
, migratetype
,
2372 static void change_pageblock_range(struct page
*pageblock_page
,
2373 int start_order
, int migratetype
)
2375 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
2377 while (nr_pageblocks
--) {
2378 set_pageblock_migratetype(pageblock_page
, migratetype
);
2379 pageblock_page
+= pageblock_nr_pages
;
2384 * When we are falling back to another migratetype during allocation, try to
2385 * steal extra free pages from the same pageblocks to satisfy further
2386 * allocations, instead of polluting multiple pageblocks.
2388 * If we are stealing a relatively large buddy page, it is likely there will
2389 * be more free pages in the pageblock, so try to steal them all. For
2390 * reclaimable and unmovable allocations, we steal regardless of page size,
2391 * as fragmentation caused by those allocations polluting movable pageblocks
2392 * is worse than movable allocations stealing from unmovable and reclaimable
2395 static bool can_steal_fallback(unsigned int order
, int start_mt
)
2398 * Leaving this order check is intended, although there is
2399 * relaxed order check in next check. The reason is that
2400 * we can actually steal whole pageblock if this condition met,
2401 * but, below check doesn't guarantee it and that is just heuristic
2402 * so could be changed anytime.
2404 if (order
>= pageblock_order
)
2407 if (order
>= pageblock_order
/ 2 ||
2408 start_mt
== MIGRATE_RECLAIMABLE
||
2409 start_mt
== MIGRATE_UNMOVABLE
||
2410 page_group_by_mobility_disabled
)
2416 static inline void boost_watermark(struct zone
*zone
)
2418 unsigned long max_boost
;
2420 if (!watermark_boost_factor
)
2423 * Don't bother in zones that are unlikely to produce results.
2424 * On small machines, including kdump capture kernels running
2425 * in a small area, boosting the watermark can cause an out of
2426 * memory situation immediately.
2428 if ((pageblock_nr_pages
* 4) > zone_managed_pages(zone
))
2431 max_boost
= mult_frac(zone
->_watermark
[WMARK_HIGH
],
2432 watermark_boost_factor
, 10000);
2435 * high watermark may be uninitialised if fragmentation occurs
2436 * very early in boot so do not boost. We do not fall
2437 * through and boost by pageblock_nr_pages as failing
2438 * allocations that early means that reclaim is not going
2439 * to help and it may even be impossible to reclaim the
2440 * boosted watermark resulting in a hang.
2445 max_boost
= max(pageblock_nr_pages
, max_boost
);
2447 zone
->watermark_boost
= min(zone
->watermark_boost
+ pageblock_nr_pages
,
2452 * This function implements actual steal behaviour. If order is large enough,
2453 * we can steal whole pageblock. If not, we first move freepages in this
2454 * pageblock to our migratetype and determine how many already-allocated pages
2455 * are there in the pageblock with a compatible migratetype. If at least half
2456 * of pages are free or compatible, we can change migratetype of the pageblock
2457 * itself, so pages freed in the future will be put on the correct free list.
2459 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2460 unsigned int alloc_flags
, int start_type
, bool whole_block
)
2462 unsigned int current_order
= page_order(page
);
2463 int free_pages
, movable_pages
, alike_pages
;
2466 old_block_type
= get_pageblock_migratetype(page
);
2469 * This can happen due to races and we want to prevent broken
2470 * highatomic accounting.
2472 if (is_migrate_highatomic(old_block_type
))
2475 /* Take ownership for orders >= pageblock_order */
2476 if (current_order
>= pageblock_order
) {
2477 change_pageblock_range(page
, current_order
, start_type
);
2482 * Boost watermarks to increase reclaim pressure to reduce the
2483 * likelihood of future fallbacks. Wake kswapd now as the node
2484 * may be balanced overall and kswapd will not wake naturally.
2486 boost_watermark(zone
);
2487 if (alloc_flags
& ALLOC_KSWAPD
)
2488 set_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
2490 /* We are not allowed to try stealing from the whole block */
2494 free_pages
= move_freepages_block(zone
, page
, start_type
,
2497 * Determine how many pages are compatible with our allocation.
2498 * For movable allocation, it's the number of movable pages which
2499 * we just obtained. For other types it's a bit more tricky.
2501 if (start_type
== MIGRATE_MOVABLE
) {
2502 alike_pages
= movable_pages
;
2505 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2506 * to MOVABLE pageblock, consider all non-movable pages as
2507 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2508 * vice versa, be conservative since we can't distinguish the
2509 * exact migratetype of non-movable pages.
2511 if (old_block_type
== MIGRATE_MOVABLE
)
2512 alike_pages
= pageblock_nr_pages
2513 - (free_pages
+ movable_pages
);
2518 /* moving whole block can fail due to zone boundary conditions */
2523 * If a sufficient number of pages in the block are either free or of
2524 * comparable migratability as our allocation, claim the whole block.
2526 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2527 page_group_by_mobility_disabled
)
2528 set_pageblock_migratetype(page
, start_type
);
2533 move_to_free_list(page
, zone
, current_order
, start_type
);
2537 * Check whether there is a suitable fallback freepage with requested order.
2538 * If only_stealable is true, this function returns fallback_mt only if
2539 * we can steal other freepages all together. This would help to reduce
2540 * fragmentation due to mixed migratetype pages in one pageblock.
2542 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2543 int migratetype
, bool only_stealable
, bool *can_steal
)
2548 if (area
->nr_free
== 0)
2553 fallback_mt
= fallbacks
[migratetype
][i
];
2554 if (fallback_mt
== MIGRATE_TYPES
)
2557 if (free_area_empty(area
, fallback_mt
))
2560 if (can_steal_fallback(order
, migratetype
))
2563 if (!only_stealable
)
2574 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2575 * there are no empty page blocks that contain a page with a suitable order
2577 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2578 unsigned int alloc_order
)
2581 unsigned long max_managed
, flags
;
2584 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2585 * Check is race-prone but harmless.
2587 max_managed
= (zone_managed_pages(zone
) / 100) + pageblock_nr_pages
;
2588 if (zone
->nr_reserved_highatomic
>= max_managed
)
2591 spin_lock_irqsave(&zone
->lock
, flags
);
2593 /* Recheck the nr_reserved_highatomic limit under the lock */
2594 if (zone
->nr_reserved_highatomic
>= max_managed
)
2598 mt
= get_pageblock_migratetype(page
);
2599 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2600 && !is_migrate_cma(mt
)) {
2601 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2602 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2603 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2607 spin_unlock_irqrestore(&zone
->lock
, flags
);
2611 * Used when an allocation is about to fail under memory pressure. This
2612 * potentially hurts the reliability of high-order allocations when under
2613 * intense memory pressure but failed atomic allocations should be easier
2614 * to recover from than an OOM.
2616 * If @force is true, try to unreserve a pageblock even though highatomic
2617 * pageblock is exhausted.
2619 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2622 struct zonelist
*zonelist
= ac
->zonelist
;
2623 unsigned long flags
;
2630 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->highest_zoneidx
,
2633 * Preserve at least one pageblock unless memory pressure
2636 if (!force
&& zone
->nr_reserved_highatomic
<=
2640 spin_lock_irqsave(&zone
->lock
, flags
);
2641 for (order
= 0; order
< MAX_ORDER
; order
++) {
2642 struct free_area
*area
= &(zone
->free_area
[order
]);
2644 page
= get_page_from_free_area(area
, MIGRATE_HIGHATOMIC
);
2649 * In page freeing path, migratetype change is racy so
2650 * we can counter several free pages in a pageblock
2651 * in this loop althoug we changed the pageblock type
2652 * from highatomic to ac->migratetype. So we should
2653 * adjust the count once.
2655 if (is_migrate_highatomic_page(page
)) {
2657 * It should never happen but changes to
2658 * locking could inadvertently allow a per-cpu
2659 * drain to add pages to MIGRATE_HIGHATOMIC
2660 * while unreserving so be safe and watch for
2663 zone
->nr_reserved_highatomic
-= min(
2665 zone
->nr_reserved_highatomic
);
2669 * Convert to ac->migratetype and avoid the normal
2670 * pageblock stealing heuristics. Minimally, the caller
2671 * is doing the work and needs the pages. More
2672 * importantly, if the block was always converted to
2673 * MIGRATE_UNMOVABLE or another type then the number
2674 * of pageblocks that cannot be completely freed
2677 set_pageblock_migratetype(page
, ac
->migratetype
);
2678 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2681 spin_unlock_irqrestore(&zone
->lock
, flags
);
2685 spin_unlock_irqrestore(&zone
->lock
, flags
);
2692 * Try finding a free buddy page on the fallback list and put it on the free
2693 * list of requested migratetype, possibly along with other pages from the same
2694 * block, depending on fragmentation avoidance heuristics. Returns true if
2695 * fallback was found so that __rmqueue_smallest() can grab it.
2697 * The use of signed ints for order and current_order is a deliberate
2698 * deviation from the rest of this file, to make the for loop
2699 * condition simpler.
2701 static __always_inline
bool
2702 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
,
2703 unsigned int alloc_flags
)
2705 struct free_area
*area
;
2707 int min_order
= order
;
2713 * Do not steal pages from freelists belonging to other pageblocks
2714 * i.e. orders < pageblock_order. If there are no local zones free,
2715 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2717 if (alloc_flags
& ALLOC_NOFRAGMENT
)
2718 min_order
= pageblock_order
;
2721 * Find the largest available free page in the other list. This roughly
2722 * approximates finding the pageblock with the most free pages, which
2723 * would be too costly to do exactly.
2725 for (current_order
= MAX_ORDER
- 1; current_order
>= min_order
;
2727 area
= &(zone
->free_area
[current_order
]);
2728 fallback_mt
= find_suitable_fallback(area
, current_order
,
2729 start_migratetype
, false, &can_steal
);
2730 if (fallback_mt
== -1)
2734 * We cannot steal all free pages from the pageblock and the
2735 * requested migratetype is movable. In that case it's better to
2736 * steal and split the smallest available page instead of the
2737 * largest available page, because even if the next movable
2738 * allocation falls back into a different pageblock than this
2739 * one, it won't cause permanent fragmentation.
2741 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2742 && current_order
> order
)
2751 for (current_order
= order
; current_order
< MAX_ORDER
;
2753 area
= &(zone
->free_area
[current_order
]);
2754 fallback_mt
= find_suitable_fallback(area
, current_order
,
2755 start_migratetype
, false, &can_steal
);
2756 if (fallback_mt
!= -1)
2761 * This should not happen - we already found a suitable fallback
2762 * when looking for the largest page.
2764 VM_BUG_ON(current_order
== MAX_ORDER
);
2767 page
= get_page_from_free_area(area
, fallback_mt
);
2769 steal_suitable_fallback(zone
, page
, alloc_flags
, start_migratetype
,
2772 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2773 start_migratetype
, fallback_mt
);
2780 * Do the hard work of removing an element from the buddy allocator.
2781 * Call me with the zone->lock already held.
2783 static __always_inline
struct page
*
2784 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
,
2785 unsigned int alloc_flags
)
2791 * Balance movable allocations between regular and CMA areas by
2792 * allocating from CMA when over half of the zone's free memory
2793 * is in the CMA area.
2795 if (alloc_flags
& ALLOC_CMA
&&
2796 zone_page_state(zone
, NR_FREE_CMA_PAGES
) >
2797 zone_page_state(zone
, NR_FREE_PAGES
) / 2) {
2798 page
= __rmqueue_cma_fallback(zone
, order
);
2804 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2805 if (unlikely(!page
)) {
2806 if (alloc_flags
& ALLOC_CMA
)
2807 page
= __rmqueue_cma_fallback(zone
, order
);
2809 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
,
2814 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2819 * Obtain a specified number of elements from the buddy allocator, all under
2820 * a single hold of the lock, for efficiency. Add them to the supplied list.
2821 * Returns the number of new pages which were placed at *list.
2823 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2824 unsigned long count
, struct list_head
*list
,
2825 int migratetype
, unsigned int alloc_flags
)
2829 spin_lock(&zone
->lock
);
2830 for (i
= 0; i
< count
; ++i
) {
2831 struct page
*page
= __rmqueue(zone
, order
, migratetype
,
2833 if (unlikely(page
== NULL
))
2836 if (unlikely(check_pcp_refill(page
)))
2840 * Split buddy pages returned by expand() are received here in
2841 * physical page order. The page is added to the tail of
2842 * caller's list. From the callers perspective, the linked list
2843 * is ordered by page number under some conditions. This is
2844 * useful for IO devices that can forward direction from the
2845 * head, thus also in the physical page order. This is useful
2846 * for IO devices that can merge IO requests if the physical
2847 * pages are ordered properly.
2849 list_add_tail(&page
->lru
, list
);
2851 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2852 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2857 * i pages were removed from the buddy list even if some leak due
2858 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2859 * on i. Do not confuse with 'alloced' which is the number of
2860 * pages added to the pcp list.
2862 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2863 spin_unlock(&zone
->lock
);
2869 * Called from the vmstat counter updater to drain pagesets of this
2870 * currently executing processor on remote nodes after they have
2873 * Note that this function must be called with the thread pinned to
2874 * a single processor.
2876 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2878 unsigned long flags
;
2879 int to_drain
, batch
;
2881 local_irq_save(flags
);
2882 batch
= READ_ONCE(pcp
->batch
);
2883 to_drain
= min(pcp
->count
, batch
);
2885 free_pcppages_bulk(zone
, to_drain
, pcp
);
2886 local_irq_restore(flags
);
2891 * Drain pcplists of the indicated processor and zone.
2893 * The processor must either be the current processor and the
2894 * thread pinned to the current processor or a processor that
2897 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2899 unsigned long flags
;
2900 struct per_cpu_pageset
*pset
;
2901 struct per_cpu_pages
*pcp
;
2903 local_irq_save(flags
);
2904 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2908 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2909 local_irq_restore(flags
);
2913 * Drain pcplists of all zones on the indicated processor.
2915 * The processor must either be the current processor and the
2916 * thread pinned to the current processor or a processor that
2919 static void drain_pages(unsigned int cpu
)
2923 for_each_populated_zone(zone
) {
2924 drain_pages_zone(cpu
, zone
);
2929 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2931 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2932 * the single zone's pages.
2934 void drain_local_pages(struct zone
*zone
)
2936 int cpu
= smp_processor_id();
2939 drain_pages_zone(cpu
, zone
);
2944 static void drain_local_pages_wq(struct work_struct
*work
)
2946 struct pcpu_drain
*drain
;
2948 drain
= container_of(work
, struct pcpu_drain
, work
);
2951 * drain_all_pages doesn't use proper cpu hotplug protection so
2952 * we can race with cpu offline when the WQ can move this from
2953 * a cpu pinned worker to an unbound one. We can operate on a different
2954 * cpu which is allright but we also have to make sure to not move to
2958 drain_local_pages(drain
->zone
);
2963 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2965 * When zone parameter is non-NULL, spill just the single zone's pages.
2967 * Note that this can be extremely slow as the draining happens in a workqueue.
2969 void drain_all_pages(struct zone
*zone
)
2974 * Allocate in the BSS so we wont require allocation in
2975 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2977 static cpumask_t cpus_with_pcps
;
2980 * Make sure nobody triggers this path before mm_percpu_wq is fully
2983 if (WARN_ON_ONCE(!mm_percpu_wq
))
2987 * Do not drain if one is already in progress unless it's specific to
2988 * a zone. Such callers are primarily CMA and memory hotplug and need
2989 * the drain to be complete when the call returns.
2991 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2994 mutex_lock(&pcpu_drain_mutex
);
2998 * We don't care about racing with CPU hotplug event
2999 * as offline notification will cause the notified
3000 * cpu to drain that CPU pcps and on_each_cpu_mask
3001 * disables preemption as part of its processing
3003 for_each_online_cpu(cpu
) {
3004 struct per_cpu_pageset
*pcp
;
3006 bool has_pcps
= false;
3009 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3013 for_each_populated_zone(z
) {
3014 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
3015 if (pcp
->pcp
.count
) {
3023 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
3025 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
3028 for_each_cpu(cpu
, &cpus_with_pcps
) {
3029 struct pcpu_drain
*drain
= per_cpu_ptr(&pcpu_drain
, cpu
);
3032 INIT_WORK(&drain
->work
, drain_local_pages_wq
);
3033 queue_work_on(cpu
, mm_percpu_wq
, &drain
->work
);
3035 for_each_cpu(cpu
, &cpus_with_pcps
)
3036 flush_work(&per_cpu_ptr(&pcpu_drain
, cpu
)->work
);
3038 mutex_unlock(&pcpu_drain_mutex
);
3041 #ifdef CONFIG_HIBERNATION
3044 * Touch the watchdog for every WD_PAGE_COUNT pages.
3046 #define WD_PAGE_COUNT (128*1024)
3048 void mark_free_pages(struct zone
*zone
)
3050 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
3051 unsigned long flags
;
3052 unsigned int order
, t
;
3055 if (zone_is_empty(zone
))
3058 spin_lock_irqsave(&zone
->lock
, flags
);
3060 max_zone_pfn
= zone_end_pfn(zone
);
3061 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
3062 if (pfn_valid(pfn
)) {
3063 page
= pfn_to_page(pfn
);
3065 if (!--page_count
) {
3066 touch_nmi_watchdog();
3067 page_count
= WD_PAGE_COUNT
;
3070 if (page_zone(page
) != zone
)
3073 if (!swsusp_page_is_forbidden(page
))
3074 swsusp_unset_page_free(page
);
3077 for_each_migratetype_order(order
, t
) {
3078 list_for_each_entry(page
,
3079 &zone
->free_area
[order
].free_list
[t
], lru
) {
3082 pfn
= page_to_pfn(page
);
3083 for (i
= 0; i
< (1UL << order
); i
++) {
3084 if (!--page_count
) {
3085 touch_nmi_watchdog();
3086 page_count
= WD_PAGE_COUNT
;
3088 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
3092 spin_unlock_irqrestore(&zone
->lock
, flags
);
3094 #endif /* CONFIG_PM */
3096 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
3100 if (!free_pcp_prepare(page
))
3103 migratetype
= get_pfnblock_migratetype(page
, pfn
);
3104 set_pcppage_migratetype(page
, migratetype
);
3108 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
3110 struct zone
*zone
= page_zone(page
);
3111 struct per_cpu_pages
*pcp
;
3114 migratetype
= get_pcppage_migratetype(page
);
3115 __count_vm_event(PGFREE
);
3118 * We only track unmovable, reclaimable and movable on pcp lists.
3119 * Free ISOLATE pages back to the allocator because they are being
3120 * offlined but treat HIGHATOMIC as movable pages so we can get those
3121 * areas back if necessary. Otherwise, we may have to free
3122 * excessively into the page allocator
3124 if (migratetype
>= MIGRATE_PCPTYPES
) {
3125 if (unlikely(is_migrate_isolate(migratetype
))) {
3126 free_one_page(zone
, page
, pfn
, 0, migratetype
);
3129 migratetype
= MIGRATE_MOVABLE
;
3132 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3133 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
3135 if (pcp
->count
>= pcp
->high
) {
3136 unsigned long batch
= READ_ONCE(pcp
->batch
);
3137 free_pcppages_bulk(zone
, batch
, pcp
);
3142 * Free a 0-order page
3144 void free_unref_page(struct page
*page
)
3146 unsigned long flags
;
3147 unsigned long pfn
= page_to_pfn(page
);
3149 if (!free_unref_page_prepare(page
, pfn
))
3152 local_irq_save(flags
);
3153 free_unref_page_commit(page
, pfn
);
3154 local_irq_restore(flags
);
3158 * Free a list of 0-order pages
3160 void free_unref_page_list(struct list_head
*list
)
3162 struct page
*page
, *next
;
3163 unsigned long flags
, pfn
;
3164 int batch_count
= 0;
3166 /* Prepare pages for freeing */
3167 list_for_each_entry_safe(page
, next
, list
, lru
) {
3168 pfn
= page_to_pfn(page
);
3169 if (!free_unref_page_prepare(page
, pfn
))
3170 list_del(&page
->lru
);
3171 set_page_private(page
, pfn
);
3174 local_irq_save(flags
);
3175 list_for_each_entry_safe(page
, next
, list
, lru
) {
3176 unsigned long pfn
= page_private(page
);
3178 set_page_private(page
, 0);
3179 trace_mm_page_free_batched(page
);
3180 free_unref_page_commit(page
, pfn
);
3183 * Guard against excessive IRQ disabled times when we get
3184 * a large list of pages to free.
3186 if (++batch_count
== SWAP_CLUSTER_MAX
) {
3187 local_irq_restore(flags
);
3189 local_irq_save(flags
);
3192 local_irq_restore(flags
);
3196 * split_page takes a non-compound higher-order page, and splits it into
3197 * n (1<<order) sub-pages: page[0..n]
3198 * Each sub-page must be freed individually.
3200 * Note: this is probably too low level an operation for use in drivers.
3201 * Please consult with lkml before using this in your driver.
3203 void split_page(struct page
*page
, unsigned int order
)
3207 VM_BUG_ON_PAGE(PageCompound(page
), page
);
3208 VM_BUG_ON_PAGE(!page_count(page
), page
);
3210 for (i
= 1; i
< (1 << order
); i
++)
3211 set_page_refcounted(page
+ i
);
3212 split_page_owner(page
, order
);
3214 EXPORT_SYMBOL_GPL(split_page
);
3216 int __isolate_free_page(struct page
*page
, unsigned int order
)
3218 unsigned long watermark
;
3222 BUG_ON(!PageBuddy(page
));
3224 zone
= page_zone(page
);
3225 mt
= get_pageblock_migratetype(page
);
3227 if (!is_migrate_isolate(mt
)) {
3229 * Obey watermarks as if the page was being allocated. We can
3230 * emulate a high-order watermark check with a raised order-0
3231 * watermark, because we already know our high-order page
3234 watermark
= zone
->_watermark
[WMARK_MIN
] + (1UL << order
);
3235 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
3238 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
3241 /* Remove page from free list */
3243 del_page_from_free_list(page
, zone
, order
);
3246 * Set the pageblock if the isolated page is at least half of a
3249 if (order
>= pageblock_order
- 1) {
3250 struct page
*endpage
= page
+ (1 << order
) - 1;
3251 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
3252 int mt
= get_pageblock_migratetype(page
);
3253 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
3254 && !is_migrate_highatomic(mt
))
3255 set_pageblock_migratetype(page
,
3261 return 1UL << order
;
3265 * __putback_isolated_page - Return a now-isolated page back where we got it
3266 * @page: Page that was isolated
3267 * @order: Order of the isolated page
3268 * @mt: The page's pageblock's migratetype
3270 * This function is meant to return a page pulled from the free lists via
3271 * __isolate_free_page back to the free lists they were pulled from.
3273 void __putback_isolated_page(struct page
*page
, unsigned int order
, int mt
)
3275 struct zone
*zone
= page_zone(page
);
3277 /* zone lock should be held when this function is called */
3278 lockdep_assert_held(&zone
->lock
);
3280 /* Return isolated page to tail of freelist. */
3281 __free_one_page(page
, page_to_pfn(page
), zone
, order
, mt
, false);
3285 * Update NUMA hit/miss statistics
3287 * Must be called with interrupts disabled.
3289 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
3292 enum numa_stat_item local_stat
= NUMA_LOCAL
;
3294 /* skip numa counters update if numa stats is disabled */
3295 if (!static_branch_likely(&vm_numa_stat_key
))
3298 if (zone_to_nid(z
) != numa_node_id())
3299 local_stat
= NUMA_OTHER
;
3301 if (zone_to_nid(z
) == zone_to_nid(preferred_zone
))
3302 __inc_numa_state(z
, NUMA_HIT
);
3304 __inc_numa_state(z
, NUMA_MISS
);
3305 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
3307 __inc_numa_state(z
, local_stat
);
3311 /* Remove page from the per-cpu list, caller must protect the list */
3312 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
3313 unsigned int alloc_flags
,
3314 struct per_cpu_pages
*pcp
,
3315 struct list_head
*list
)
3320 if (list_empty(list
)) {
3321 pcp
->count
+= rmqueue_bulk(zone
, 0,
3323 migratetype
, alloc_flags
);
3324 if (unlikely(list_empty(list
)))
3328 page
= list_first_entry(list
, struct page
, lru
);
3329 list_del(&page
->lru
);
3331 } while (check_new_pcp(page
));
3336 /* Lock and remove page from the per-cpu list */
3337 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
3338 struct zone
*zone
, gfp_t gfp_flags
,
3339 int migratetype
, unsigned int alloc_flags
)
3341 struct per_cpu_pages
*pcp
;
3342 struct list_head
*list
;
3344 unsigned long flags
;
3346 local_irq_save(flags
);
3347 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3348 list
= &pcp
->lists
[migratetype
];
3349 page
= __rmqueue_pcplist(zone
, migratetype
, alloc_flags
, pcp
, list
);
3351 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1);
3352 zone_statistics(preferred_zone
, zone
);
3354 local_irq_restore(flags
);
3359 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3362 struct page
*rmqueue(struct zone
*preferred_zone
,
3363 struct zone
*zone
, unsigned int order
,
3364 gfp_t gfp_flags
, unsigned int alloc_flags
,
3367 unsigned long flags
;
3370 if (likely(order
== 0)) {
3372 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3373 * we need to skip it when CMA area isn't allowed.
3375 if (!IS_ENABLED(CONFIG_CMA
) || alloc_flags
& ALLOC_CMA
||
3376 migratetype
!= MIGRATE_MOVABLE
) {
3377 page
= rmqueue_pcplist(preferred_zone
, zone
, gfp_flags
,
3378 migratetype
, alloc_flags
);
3384 * We most definitely don't want callers attempting to
3385 * allocate greater than order-1 page units with __GFP_NOFAIL.
3387 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
3388 spin_lock_irqsave(&zone
->lock
, flags
);
3393 * order-0 request can reach here when the pcplist is skipped
3394 * due to non-CMA allocation context. HIGHATOMIC area is
3395 * reserved for high-order atomic allocation, so order-0
3396 * request should skip it.
3398 if (order
> 0 && alloc_flags
& ALLOC_HARDER
) {
3399 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
3401 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
3404 page
= __rmqueue(zone
, order
, migratetype
, alloc_flags
);
3405 } while (page
&& check_new_pages(page
, order
));
3406 spin_unlock(&zone
->lock
);
3409 __mod_zone_freepage_state(zone
, -(1 << order
),
3410 get_pcppage_migratetype(page
));
3412 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
3413 zone_statistics(preferred_zone
, zone
);
3414 local_irq_restore(flags
);
3417 /* Separate test+clear to avoid unnecessary atomics */
3418 if (test_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
)) {
3419 clear_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
3420 wakeup_kswapd(zone
, 0, 0, zone_idx(zone
));
3423 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
3427 local_irq_restore(flags
);
3431 #ifdef CONFIG_FAIL_PAGE_ALLOC
3434 struct fault_attr attr
;
3436 bool ignore_gfp_highmem
;
3437 bool ignore_gfp_reclaim
;
3439 } fail_page_alloc
= {
3440 .attr
= FAULT_ATTR_INITIALIZER
,
3441 .ignore_gfp_reclaim
= true,
3442 .ignore_gfp_highmem
= true,
3446 static int __init
setup_fail_page_alloc(char *str
)
3448 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
3450 __setup("fail_page_alloc=", setup_fail_page_alloc
);
3452 static bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3454 if (order
< fail_page_alloc
.min_order
)
3456 if (gfp_mask
& __GFP_NOFAIL
)
3458 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
3460 if (fail_page_alloc
.ignore_gfp_reclaim
&&
3461 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
3464 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
3467 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3469 static int __init
fail_page_alloc_debugfs(void)
3471 umode_t mode
= S_IFREG
| 0600;
3474 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
3475 &fail_page_alloc
.attr
);
3477 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
3478 &fail_page_alloc
.ignore_gfp_reclaim
);
3479 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
3480 &fail_page_alloc
.ignore_gfp_highmem
);
3481 debugfs_create_u32("min-order", mode
, dir
, &fail_page_alloc
.min_order
);
3486 late_initcall(fail_page_alloc_debugfs
);
3488 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3490 #else /* CONFIG_FAIL_PAGE_ALLOC */
3492 static inline bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3497 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3499 static noinline
bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3501 return __should_fail_alloc_page(gfp_mask
, order
);
3503 ALLOW_ERROR_INJECTION(should_fail_alloc_page
, TRUE
);
3505 static inline long __zone_watermark_unusable_free(struct zone
*z
,
3506 unsigned int order
, unsigned int alloc_flags
)
3508 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3509 long unusable_free
= (1 << order
) - 1;
3512 * If the caller does not have rights to ALLOC_HARDER then subtract
3513 * the high-atomic reserves. This will over-estimate the size of the
3514 * atomic reserve but it avoids a search.
3516 if (likely(!alloc_harder
))
3517 unusable_free
+= z
->nr_reserved_highatomic
;
3520 /* If allocation can't use CMA areas don't use free CMA pages */
3521 if (!(alloc_flags
& ALLOC_CMA
))
3522 unusable_free
+= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3525 return unusable_free
;
3529 * Return true if free base pages are above 'mark'. For high-order checks it
3530 * will return true of the order-0 watermark is reached and there is at least
3531 * one free page of a suitable size. Checking now avoids taking the zone lock
3532 * to check in the allocation paths if no pages are free.
3534 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3535 int highest_zoneidx
, unsigned int alloc_flags
,
3540 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3542 /* free_pages may go negative - that's OK */
3543 free_pages
-= __zone_watermark_unusable_free(z
, order
, alloc_flags
);
3545 if (alloc_flags
& ALLOC_HIGH
)
3548 if (unlikely(alloc_harder
)) {
3550 * OOM victims can try even harder than normal ALLOC_HARDER
3551 * users on the grounds that it's definitely going to be in
3552 * the exit path shortly and free memory. Any allocation it
3553 * makes during the free path will be small and short-lived.
3555 if (alloc_flags
& ALLOC_OOM
)
3562 * Check watermarks for an order-0 allocation request. If these
3563 * are not met, then a high-order request also cannot go ahead
3564 * even if a suitable page happened to be free.
3566 if (free_pages
<= min
+ z
->lowmem_reserve
[highest_zoneidx
])
3569 /* If this is an order-0 request then the watermark is fine */
3573 /* For a high-order request, check at least one suitable page is free */
3574 for (o
= order
; o
< MAX_ORDER
; o
++) {
3575 struct free_area
*area
= &z
->free_area
[o
];
3581 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3582 if (!free_area_empty(area
, mt
))
3587 if ((alloc_flags
& ALLOC_CMA
) &&
3588 !free_area_empty(area
, MIGRATE_CMA
)) {
3592 if (alloc_harder
&& !free_area_empty(area
, MIGRATE_HIGHATOMIC
))
3598 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3599 int highest_zoneidx
, unsigned int alloc_flags
)
3601 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3602 zone_page_state(z
, NR_FREE_PAGES
));
3605 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3606 unsigned long mark
, int highest_zoneidx
,
3607 unsigned int alloc_flags
, gfp_t gfp_mask
)
3611 free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3614 * Fast check for order-0 only. If this fails then the reserves
3615 * need to be calculated.
3620 fast_free
= free_pages
;
3621 fast_free
-= __zone_watermark_unusable_free(z
, 0, alloc_flags
);
3622 if (fast_free
> mark
+ z
->lowmem_reserve
[highest_zoneidx
])
3626 if (__zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3630 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3631 * when checking the min watermark. The min watermark is the
3632 * point where boosting is ignored so that kswapd is woken up
3633 * when below the low watermark.
3635 if (unlikely(!order
&& (gfp_mask
& __GFP_ATOMIC
) && z
->watermark_boost
3636 && ((alloc_flags
& ALLOC_WMARK_MASK
) == WMARK_MIN
))) {
3637 mark
= z
->_watermark
[WMARK_MIN
];
3638 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
,
3639 alloc_flags
, free_pages
);
3645 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3646 unsigned long mark
, int highest_zoneidx
)
3648 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3650 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3651 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3653 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, 0,
3658 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3660 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3661 node_reclaim_distance
;
3663 #else /* CONFIG_NUMA */
3664 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3668 #endif /* CONFIG_NUMA */
3671 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3672 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3673 * premature use of a lower zone may cause lowmem pressure problems that
3674 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3675 * probably too small. It only makes sense to spread allocations to avoid
3676 * fragmentation between the Normal and DMA32 zones.
3678 static inline unsigned int
3679 alloc_flags_nofragment(struct zone
*zone
, gfp_t gfp_mask
)
3681 unsigned int alloc_flags
;
3684 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3687 alloc_flags
= (__force
int) (gfp_mask
& __GFP_KSWAPD_RECLAIM
);
3689 #ifdef CONFIG_ZONE_DMA32
3693 if (zone_idx(zone
) != ZONE_NORMAL
)
3697 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3698 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3699 * on UMA that if Normal is populated then so is DMA32.
3701 BUILD_BUG_ON(ZONE_NORMAL
- ZONE_DMA32
!= 1);
3702 if (nr_online_nodes
> 1 && !populated_zone(--zone
))
3705 alloc_flags
|= ALLOC_NOFRAGMENT
;
3706 #endif /* CONFIG_ZONE_DMA32 */
3710 static inline unsigned int current_alloc_flags(gfp_t gfp_mask
,
3711 unsigned int alloc_flags
)
3714 unsigned int pflags
= current
->flags
;
3716 if (!(pflags
& PF_MEMALLOC_NOCMA
) &&
3717 gfp_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3718 alloc_flags
|= ALLOC_CMA
;
3725 * get_page_from_freelist goes through the zonelist trying to allocate
3728 static struct page
*
3729 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3730 const struct alloc_context
*ac
)
3734 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3739 * Scan zonelist, looking for a zone with enough free.
3740 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3742 no_fallback
= alloc_flags
& ALLOC_NOFRAGMENT
;
3743 z
= ac
->preferred_zoneref
;
3744 for_next_zone_zonelist_nodemask(zone
, z
, ac
->highest_zoneidx
,
3749 if (cpusets_enabled() &&
3750 (alloc_flags
& ALLOC_CPUSET
) &&
3751 !__cpuset_zone_allowed(zone
, gfp_mask
))
3754 * When allocating a page cache page for writing, we
3755 * want to get it from a node that is within its dirty
3756 * limit, such that no single node holds more than its
3757 * proportional share of globally allowed dirty pages.
3758 * The dirty limits take into account the node's
3759 * lowmem reserves and high watermark so that kswapd
3760 * should be able to balance it without having to
3761 * write pages from its LRU list.
3763 * XXX: For now, allow allocations to potentially
3764 * exceed the per-node dirty limit in the slowpath
3765 * (spread_dirty_pages unset) before going into reclaim,
3766 * which is important when on a NUMA setup the allowed
3767 * nodes are together not big enough to reach the
3768 * global limit. The proper fix for these situations
3769 * will require awareness of nodes in the
3770 * dirty-throttling and the flusher threads.
3772 if (ac
->spread_dirty_pages
) {
3773 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3776 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3777 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3782 if (no_fallback
&& nr_online_nodes
> 1 &&
3783 zone
!= ac
->preferred_zoneref
->zone
) {
3787 * If moving to a remote node, retry but allow
3788 * fragmenting fallbacks. Locality is more important
3789 * than fragmentation avoidance.
3791 local_nid
= zone_to_nid(ac
->preferred_zoneref
->zone
);
3792 if (zone_to_nid(zone
) != local_nid
) {
3793 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3798 mark
= wmark_pages(zone
, alloc_flags
& ALLOC_WMARK_MASK
);
3799 if (!zone_watermark_fast(zone
, order
, mark
,
3800 ac
->highest_zoneidx
, alloc_flags
,
3804 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3806 * Watermark failed for this zone, but see if we can
3807 * grow this zone if it contains deferred pages.
3809 if (static_branch_unlikely(&deferred_pages
)) {
3810 if (_deferred_grow_zone(zone
, order
))
3814 /* Checked here to keep the fast path fast */
3815 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3816 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3819 if (node_reclaim_mode
== 0 ||
3820 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3823 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3825 case NODE_RECLAIM_NOSCAN
:
3828 case NODE_RECLAIM_FULL
:
3829 /* scanned but unreclaimable */
3832 /* did we reclaim enough */
3833 if (zone_watermark_ok(zone
, order
, mark
,
3834 ac
->highest_zoneidx
, alloc_flags
))
3842 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3843 gfp_mask
, alloc_flags
, ac
->migratetype
);
3845 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3848 * If this is a high-order atomic allocation then check
3849 * if the pageblock should be reserved for the future
3851 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3852 reserve_highatomic_pageblock(page
, zone
, order
);
3856 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3857 /* Try again if zone has deferred pages */
3858 if (static_branch_unlikely(&deferred_pages
)) {
3859 if (_deferred_grow_zone(zone
, order
))
3867 * It's possible on a UMA machine to get through all zones that are
3868 * fragmented. If avoiding fragmentation, reset and try again.
3871 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3878 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3880 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3883 * This documents exceptions given to allocations in certain
3884 * contexts that are allowed to allocate outside current's set
3887 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3888 if (tsk_is_oom_victim(current
) ||
3889 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3890 filter
&= ~SHOW_MEM_FILTER_NODES
;
3891 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3892 filter
&= ~SHOW_MEM_FILTER_NODES
;
3894 show_mem(filter
, nodemask
);
3897 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3899 struct va_format vaf
;
3901 static DEFINE_RATELIMIT_STATE(nopage_rs
, 10*HZ
, 1);
3903 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3906 va_start(args
, fmt
);
3909 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
3910 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
3911 nodemask_pr_args(nodemask
));
3914 cpuset_print_current_mems_allowed();
3917 warn_alloc_show_mem(gfp_mask
, nodemask
);
3920 static inline struct page
*
3921 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3922 unsigned int alloc_flags
,
3923 const struct alloc_context
*ac
)
3927 page
= get_page_from_freelist(gfp_mask
, order
,
3928 alloc_flags
|ALLOC_CPUSET
, ac
);
3930 * fallback to ignore cpuset restriction if our nodes
3934 page
= get_page_from_freelist(gfp_mask
, order
,
3940 static inline struct page
*
3941 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3942 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3944 struct oom_control oc
= {
3945 .zonelist
= ac
->zonelist
,
3946 .nodemask
= ac
->nodemask
,
3948 .gfp_mask
= gfp_mask
,
3953 *did_some_progress
= 0;
3956 * Acquire the oom lock. If that fails, somebody else is
3957 * making progress for us.
3959 if (!mutex_trylock(&oom_lock
)) {
3960 *did_some_progress
= 1;
3961 schedule_timeout_uninterruptible(1);
3966 * Go through the zonelist yet one more time, keep very high watermark
3967 * here, this is only to catch a parallel oom killing, we must fail if
3968 * we're still under heavy pressure. But make sure that this reclaim
3969 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3970 * allocation which will never fail due to oom_lock already held.
3972 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
3973 ~__GFP_DIRECT_RECLAIM
, order
,
3974 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3978 /* Coredumps can quickly deplete all memory reserves */
3979 if (current
->flags
& PF_DUMPCORE
)
3981 /* The OOM killer will not help higher order allocs */
3982 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3985 * We have already exhausted all our reclaim opportunities without any
3986 * success so it is time to admit defeat. We will skip the OOM killer
3987 * because it is very likely that the caller has a more reasonable
3988 * fallback than shooting a random task.
3990 * The OOM killer may not free memory on a specific node.
3992 if (gfp_mask
& (__GFP_RETRY_MAYFAIL
| __GFP_THISNODE
))
3994 /* The OOM killer does not needlessly kill tasks for lowmem */
3995 if (ac
->highest_zoneidx
< ZONE_NORMAL
)
3997 if (pm_suspended_storage())
4000 * XXX: GFP_NOFS allocations should rather fail than rely on
4001 * other request to make a forward progress.
4002 * We are in an unfortunate situation where out_of_memory cannot
4003 * do much for this context but let's try it to at least get
4004 * access to memory reserved if the current task is killed (see
4005 * out_of_memory). Once filesystems are ready to handle allocation
4006 * failures more gracefully we should just bail out here.
4009 /* Exhausted what can be done so it's blame time */
4010 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
4011 *did_some_progress
= 1;
4014 * Help non-failing allocations by giving them access to memory
4017 if (gfp_mask
& __GFP_NOFAIL
)
4018 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
4019 ALLOC_NO_WATERMARKS
, ac
);
4022 mutex_unlock(&oom_lock
);
4027 * Maximum number of compaction retries wit a progress before OOM
4028 * killer is consider as the only way to move forward.
4030 #define MAX_COMPACT_RETRIES 16
4032 #ifdef CONFIG_COMPACTION
4033 /* Try memory compaction for high-order allocations before reclaim */
4034 static struct page
*
4035 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4036 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4037 enum compact_priority prio
, enum compact_result
*compact_result
)
4039 struct page
*page
= NULL
;
4040 unsigned long pflags
;
4041 unsigned int noreclaim_flag
;
4046 psi_memstall_enter(&pflags
);
4047 noreclaim_flag
= memalloc_noreclaim_save();
4049 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
4052 memalloc_noreclaim_restore(noreclaim_flag
);
4053 psi_memstall_leave(&pflags
);
4056 * At least in one zone compaction wasn't deferred or skipped, so let's
4057 * count a compaction stall
4059 count_vm_event(COMPACTSTALL
);
4061 /* Prep a captured page if available */
4063 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
4065 /* Try get a page from the freelist if available */
4067 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4070 struct zone
*zone
= page_zone(page
);
4072 zone
->compact_blockskip_flush
= false;
4073 compaction_defer_reset(zone
, order
, true);
4074 count_vm_event(COMPACTSUCCESS
);
4079 * It's bad if compaction run occurs and fails. The most likely reason
4080 * is that pages exist, but not enough to satisfy watermarks.
4082 count_vm_event(COMPACTFAIL
);
4090 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
4091 enum compact_result compact_result
,
4092 enum compact_priority
*compact_priority
,
4093 int *compaction_retries
)
4095 int max_retries
= MAX_COMPACT_RETRIES
;
4098 int retries
= *compaction_retries
;
4099 enum compact_priority priority
= *compact_priority
;
4104 if (compaction_made_progress(compact_result
))
4105 (*compaction_retries
)++;
4108 * compaction considers all the zone as desperately out of memory
4109 * so it doesn't really make much sense to retry except when the
4110 * failure could be caused by insufficient priority
4112 if (compaction_failed(compact_result
))
4113 goto check_priority
;
4116 * compaction was skipped because there are not enough order-0 pages
4117 * to work with, so we retry only if it looks like reclaim can help.
4119 if (compaction_needs_reclaim(compact_result
)) {
4120 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
4125 * make sure the compaction wasn't deferred or didn't bail out early
4126 * due to locks contention before we declare that we should give up.
4127 * But the next retry should use a higher priority if allowed, so
4128 * we don't just keep bailing out endlessly.
4130 if (compaction_withdrawn(compact_result
)) {
4131 goto check_priority
;
4135 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4136 * costly ones because they are de facto nofail and invoke OOM
4137 * killer to move on while costly can fail and users are ready
4138 * to cope with that. 1/4 retries is rather arbitrary but we
4139 * would need much more detailed feedback from compaction to
4140 * make a better decision.
4142 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4144 if (*compaction_retries
<= max_retries
) {
4150 * Make sure there are attempts at the highest priority if we exhausted
4151 * all retries or failed at the lower priorities.
4154 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
4155 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
4157 if (*compact_priority
> min_priority
) {
4158 (*compact_priority
)--;
4159 *compaction_retries
= 0;
4163 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
4167 static inline struct page
*
4168 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4169 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4170 enum compact_priority prio
, enum compact_result
*compact_result
)
4172 *compact_result
= COMPACT_SKIPPED
;
4177 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
4178 enum compact_result compact_result
,
4179 enum compact_priority
*compact_priority
,
4180 int *compaction_retries
)
4185 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
4189 * There are setups with compaction disabled which would prefer to loop
4190 * inside the allocator rather than hit the oom killer prematurely.
4191 * Let's give them a good hope and keep retrying while the order-0
4192 * watermarks are OK.
4194 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4195 ac
->highest_zoneidx
, ac
->nodemask
) {
4196 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
4197 ac
->highest_zoneidx
, alloc_flags
))
4202 #endif /* CONFIG_COMPACTION */
4204 #ifdef CONFIG_LOCKDEP
4205 static struct lockdep_map __fs_reclaim_map
=
4206 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
4208 static bool __need_fs_reclaim(gfp_t gfp_mask
)
4210 gfp_mask
= current_gfp_context(gfp_mask
);
4212 /* no reclaim without waiting on it */
4213 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
4216 /* this guy won't enter reclaim */
4217 if (current
->flags
& PF_MEMALLOC
)
4220 /* We're only interested __GFP_FS allocations for now */
4221 if (!(gfp_mask
& __GFP_FS
))
4224 if (gfp_mask
& __GFP_NOLOCKDEP
)
4230 void __fs_reclaim_acquire(void)
4232 lock_map_acquire(&__fs_reclaim_map
);
4235 void __fs_reclaim_release(void)
4237 lock_map_release(&__fs_reclaim_map
);
4240 void fs_reclaim_acquire(gfp_t gfp_mask
)
4242 if (__need_fs_reclaim(gfp_mask
))
4243 __fs_reclaim_acquire();
4245 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
4247 void fs_reclaim_release(gfp_t gfp_mask
)
4249 if (__need_fs_reclaim(gfp_mask
))
4250 __fs_reclaim_release();
4252 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
4255 /* Perform direct synchronous page reclaim */
4256 static unsigned long
4257 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
4258 const struct alloc_context
*ac
)
4260 unsigned int noreclaim_flag
;
4261 unsigned long pflags
, progress
;
4265 /* We now go into synchronous reclaim */
4266 cpuset_memory_pressure_bump();
4267 psi_memstall_enter(&pflags
);
4268 fs_reclaim_acquire(gfp_mask
);
4269 noreclaim_flag
= memalloc_noreclaim_save();
4271 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
4274 memalloc_noreclaim_restore(noreclaim_flag
);
4275 fs_reclaim_release(gfp_mask
);
4276 psi_memstall_leave(&pflags
);
4283 /* The really slow allocator path where we enter direct reclaim */
4284 static inline struct page
*
4285 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
4286 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4287 unsigned long *did_some_progress
)
4289 struct page
*page
= NULL
;
4290 bool drained
= false;
4292 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
4293 if (unlikely(!(*did_some_progress
)))
4297 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4300 * If an allocation failed after direct reclaim, it could be because
4301 * pages are pinned on the per-cpu lists or in high alloc reserves.
4302 * Shrink them and try again
4304 if (!page
&& !drained
) {
4305 unreserve_highatomic_pageblock(ac
, false);
4306 drain_all_pages(NULL
);
4314 static void wake_all_kswapds(unsigned int order
, gfp_t gfp_mask
,
4315 const struct alloc_context
*ac
)
4319 pg_data_t
*last_pgdat
= NULL
;
4320 enum zone_type highest_zoneidx
= ac
->highest_zoneidx
;
4322 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, highest_zoneidx
,
4324 if (last_pgdat
!= zone
->zone_pgdat
)
4325 wakeup_kswapd(zone
, gfp_mask
, order
, highest_zoneidx
);
4326 last_pgdat
= zone
->zone_pgdat
;
4330 static inline unsigned int
4331 gfp_to_alloc_flags(gfp_t gfp_mask
)
4333 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
4336 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4337 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4338 * to save two branches.
4340 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
4341 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM
!= (__force gfp_t
) ALLOC_KSWAPD
);
4344 * The caller may dip into page reserves a bit more if the caller
4345 * cannot run direct reclaim, or if the caller has realtime scheduling
4346 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4347 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4349 alloc_flags
|= (__force
int)
4350 (gfp_mask
& (__GFP_HIGH
| __GFP_KSWAPD_RECLAIM
));
4352 if (gfp_mask
& __GFP_ATOMIC
) {
4354 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4355 * if it can't schedule.
4357 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
4358 alloc_flags
|= ALLOC_HARDER
;
4360 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4361 * comment for __cpuset_node_allowed().
4363 alloc_flags
&= ~ALLOC_CPUSET
;
4364 } else if (unlikely(rt_task(current
)) && !in_interrupt())
4365 alloc_flags
|= ALLOC_HARDER
;
4367 alloc_flags
= current_alloc_flags(gfp_mask
, alloc_flags
);
4372 static bool oom_reserves_allowed(struct task_struct
*tsk
)
4374 if (!tsk_is_oom_victim(tsk
))
4378 * !MMU doesn't have oom reaper so give access to memory reserves
4379 * only to the thread with TIF_MEMDIE set
4381 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
4388 * Distinguish requests which really need access to full memory
4389 * reserves from oom victims which can live with a portion of it
4391 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
4393 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
4395 if (gfp_mask
& __GFP_MEMALLOC
)
4396 return ALLOC_NO_WATERMARKS
;
4397 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
4398 return ALLOC_NO_WATERMARKS
;
4399 if (!in_interrupt()) {
4400 if (current
->flags
& PF_MEMALLOC
)
4401 return ALLOC_NO_WATERMARKS
;
4402 else if (oom_reserves_allowed(current
))
4409 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
4411 return !!__gfp_pfmemalloc_flags(gfp_mask
);
4415 * Checks whether it makes sense to retry the reclaim to make a forward progress
4416 * for the given allocation request.
4418 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4419 * without success, or when we couldn't even meet the watermark if we
4420 * reclaimed all remaining pages on the LRU lists.
4422 * Returns true if a retry is viable or false to enter the oom path.
4425 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
4426 struct alloc_context
*ac
, int alloc_flags
,
4427 bool did_some_progress
, int *no_progress_loops
)
4434 * Costly allocations might have made a progress but this doesn't mean
4435 * their order will become available due to high fragmentation so
4436 * always increment the no progress counter for them
4438 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
4439 *no_progress_loops
= 0;
4441 (*no_progress_loops
)++;
4444 * Make sure we converge to OOM if we cannot make any progress
4445 * several times in the row.
4447 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
4448 /* Before OOM, exhaust highatomic_reserve */
4449 return unreserve_highatomic_pageblock(ac
, true);
4453 * Keep reclaiming pages while there is a chance this will lead
4454 * somewhere. If none of the target zones can satisfy our allocation
4455 * request even if all reclaimable pages are considered then we are
4456 * screwed and have to go OOM.
4458 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4459 ac
->highest_zoneidx
, ac
->nodemask
) {
4460 unsigned long available
;
4461 unsigned long reclaimable
;
4462 unsigned long min_wmark
= min_wmark_pages(zone
);
4465 available
= reclaimable
= zone_reclaimable_pages(zone
);
4466 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
4469 * Would the allocation succeed if we reclaimed all
4470 * reclaimable pages?
4472 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
4473 ac
->highest_zoneidx
, alloc_flags
, available
);
4474 trace_reclaim_retry_zone(z
, order
, reclaimable
,
4475 available
, min_wmark
, *no_progress_loops
, wmark
);
4478 * If we didn't make any progress and have a lot of
4479 * dirty + writeback pages then we should wait for
4480 * an IO to complete to slow down the reclaim and
4481 * prevent from pre mature OOM
4483 if (!did_some_progress
) {
4484 unsigned long write_pending
;
4486 write_pending
= zone_page_state_snapshot(zone
,
4487 NR_ZONE_WRITE_PENDING
);
4489 if (2 * write_pending
> reclaimable
) {
4490 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4502 * Memory allocation/reclaim might be called from a WQ context and the
4503 * current implementation of the WQ concurrency control doesn't
4504 * recognize that a particular WQ is congested if the worker thread is
4505 * looping without ever sleeping. Therefore we have to do a short sleep
4506 * here rather than calling cond_resched().
4508 if (current
->flags
& PF_WQ_WORKER
)
4509 schedule_timeout_uninterruptible(1);
4516 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
4519 * It's possible that cpuset's mems_allowed and the nodemask from
4520 * mempolicy don't intersect. This should be normally dealt with by
4521 * policy_nodemask(), but it's possible to race with cpuset update in
4522 * such a way the check therein was true, and then it became false
4523 * before we got our cpuset_mems_cookie here.
4524 * This assumes that for all allocations, ac->nodemask can come only
4525 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4526 * when it does not intersect with the cpuset restrictions) or the
4527 * caller can deal with a violated nodemask.
4529 if (cpusets_enabled() && ac
->nodemask
&&
4530 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
4531 ac
->nodemask
= NULL
;
4536 * When updating a task's mems_allowed or mempolicy nodemask, it is
4537 * possible to race with parallel threads in such a way that our
4538 * allocation can fail while the mask is being updated. If we are about
4539 * to fail, check if the cpuset changed during allocation and if so,
4542 if (read_mems_allowed_retry(cpuset_mems_cookie
))
4548 static inline struct page
*
4549 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
4550 struct alloc_context
*ac
)
4552 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
4553 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
4554 struct page
*page
= NULL
;
4555 unsigned int alloc_flags
;
4556 unsigned long did_some_progress
;
4557 enum compact_priority compact_priority
;
4558 enum compact_result compact_result
;
4559 int compaction_retries
;
4560 int no_progress_loops
;
4561 unsigned int cpuset_mems_cookie
;
4565 * We also sanity check to catch abuse of atomic reserves being used by
4566 * callers that are not in atomic context.
4568 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
4569 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
4570 gfp_mask
&= ~__GFP_ATOMIC
;
4573 compaction_retries
= 0;
4574 no_progress_loops
= 0;
4575 compact_priority
= DEF_COMPACT_PRIORITY
;
4576 cpuset_mems_cookie
= read_mems_allowed_begin();
4579 * The fast path uses conservative alloc_flags to succeed only until
4580 * kswapd needs to be woken up, and to avoid the cost of setting up
4581 * alloc_flags precisely. So we do that now.
4583 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
4586 * We need to recalculate the starting point for the zonelist iterator
4587 * because we might have used different nodemask in the fast path, or
4588 * there was a cpuset modification and we are retrying - otherwise we
4589 * could end up iterating over non-eligible zones endlessly.
4591 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4592 ac
->highest_zoneidx
, ac
->nodemask
);
4593 if (!ac
->preferred_zoneref
->zone
)
4596 if (alloc_flags
& ALLOC_KSWAPD
)
4597 wake_all_kswapds(order
, gfp_mask
, ac
);
4600 * The adjusted alloc_flags might result in immediate success, so try
4603 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4608 * For costly allocations, try direct compaction first, as it's likely
4609 * that we have enough base pages and don't need to reclaim. For non-
4610 * movable high-order allocations, do that as well, as compaction will
4611 * try prevent permanent fragmentation by migrating from blocks of the
4613 * Don't try this for allocations that are allowed to ignore
4614 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4616 if (can_direct_reclaim
&&
4618 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
4619 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
4620 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
4622 INIT_COMPACT_PRIORITY
,
4628 * Checks for costly allocations with __GFP_NORETRY, which
4629 * includes some THP page fault allocations
4631 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
4633 * If allocating entire pageblock(s) and compaction
4634 * failed because all zones are below low watermarks
4635 * or is prohibited because it recently failed at this
4636 * order, fail immediately unless the allocator has
4637 * requested compaction and reclaim retry.
4640 * - potentially very expensive because zones are far
4641 * below their low watermarks or this is part of very
4642 * bursty high order allocations,
4643 * - not guaranteed to help because isolate_freepages()
4644 * may not iterate over freed pages as part of its
4646 * - unlikely to make entire pageblocks free on its
4649 if (compact_result
== COMPACT_SKIPPED
||
4650 compact_result
== COMPACT_DEFERRED
)
4654 * Looks like reclaim/compaction is worth trying, but
4655 * sync compaction could be very expensive, so keep
4656 * using async compaction.
4658 compact_priority
= INIT_COMPACT_PRIORITY
;
4663 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4664 if (alloc_flags
& ALLOC_KSWAPD
)
4665 wake_all_kswapds(order
, gfp_mask
, ac
);
4667 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4669 alloc_flags
= current_alloc_flags(gfp_mask
, reserve_flags
);
4672 * Reset the nodemask and zonelist iterators if memory policies can be
4673 * ignored. These allocations are high priority and system rather than
4676 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4677 ac
->nodemask
= NULL
;
4678 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4679 ac
->highest_zoneidx
, ac
->nodemask
);
4682 /* Attempt with potentially adjusted zonelist and alloc_flags */
4683 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4687 /* Caller is not willing to reclaim, we can't balance anything */
4688 if (!can_direct_reclaim
)
4691 /* Avoid recursion of direct reclaim */
4692 if (current
->flags
& PF_MEMALLOC
)
4695 /* Try direct reclaim and then allocating */
4696 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4697 &did_some_progress
);
4701 /* Try direct compaction and then allocating */
4702 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4703 compact_priority
, &compact_result
);
4707 /* Do not loop if specifically requested */
4708 if (gfp_mask
& __GFP_NORETRY
)
4712 * Do not retry costly high order allocations unless they are
4713 * __GFP_RETRY_MAYFAIL
4715 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4718 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4719 did_some_progress
> 0, &no_progress_loops
))
4723 * It doesn't make any sense to retry for the compaction if the order-0
4724 * reclaim is not able to make any progress because the current
4725 * implementation of the compaction depends on the sufficient amount
4726 * of free memory (see __compaction_suitable)
4728 if (did_some_progress
> 0 &&
4729 should_compact_retry(ac
, order
, alloc_flags
,
4730 compact_result
, &compact_priority
,
4731 &compaction_retries
))
4735 /* Deal with possible cpuset update races before we start OOM killing */
4736 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4739 /* Reclaim has failed us, start killing things */
4740 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4744 /* Avoid allocations with no watermarks from looping endlessly */
4745 if (tsk_is_oom_victim(current
) &&
4746 (alloc_flags
& ALLOC_OOM
||
4747 (gfp_mask
& __GFP_NOMEMALLOC
)))
4750 /* Retry as long as the OOM killer is making progress */
4751 if (did_some_progress
) {
4752 no_progress_loops
= 0;
4757 /* Deal with possible cpuset update races before we fail */
4758 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4762 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4765 if (gfp_mask
& __GFP_NOFAIL
) {
4767 * All existing users of the __GFP_NOFAIL are blockable, so warn
4768 * of any new users that actually require GFP_NOWAIT
4770 if (WARN_ON_ONCE(!can_direct_reclaim
))
4774 * PF_MEMALLOC request from this context is rather bizarre
4775 * because we cannot reclaim anything and only can loop waiting
4776 * for somebody to do a work for us
4778 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4781 * non failing costly orders are a hard requirement which we
4782 * are not prepared for much so let's warn about these users
4783 * so that we can identify them and convert them to something
4786 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4789 * Help non-failing allocations by giving them access to memory
4790 * reserves but do not use ALLOC_NO_WATERMARKS because this
4791 * could deplete whole memory reserves which would just make
4792 * the situation worse
4794 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4802 warn_alloc(gfp_mask
, ac
->nodemask
,
4803 "page allocation failure: order:%u", order
);
4808 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4809 int preferred_nid
, nodemask_t
*nodemask
,
4810 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4811 unsigned int *alloc_flags
)
4813 ac
->highest_zoneidx
= gfp_zone(gfp_mask
);
4814 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4815 ac
->nodemask
= nodemask
;
4816 ac
->migratetype
= gfp_migratetype(gfp_mask
);
4818 if (cpusets_enabled()) {
4819 *alloc_mask
|= __GFP_HARDWALL
;
4821 * When we are in the interrupt context, it is irrelevant
4822 * to the current task context. It means that any node ok.
4824 if (!in_interrupt() && !ac
->nodemask
)
4825 ac
->nodemask
= &cpuset_current_mems_allowed
;
4827 *alloc_flags
|= ALLOC_CPUSET
;
4830 fs_reclaim_acquire(gfp_mask
);
4831 fs_reclaim_release(gfp_mask
);
4833 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4835 if (should_fail_alloc_page(gfp_mask
, order
))
4838 *alloc_flags
= current_alloc_flags(gfp_mask
, *alloc_flags
);
4840 /* Dirty zone balancing only done in the fast path */
4841 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4844 * The preferred zone is used for statistics but crucially it is
4845 * also used as the starting point for the zonelist iterator. It
4846 * may get reset for allocations that ignore memory policies.
4848 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4849 ac
->highest_zoneidx
, ac
->nodemask
);
4855 * This is the 'heart' of the zoned buddy allocator.
4858 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4859 nodemask_t
*nodemask
)
4862 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4863 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4864 struct alloc_context ac
= { };
4867 * There are several places where we assume that the order value is sane
4868 * so bail out early if the request is out of bound.
4870 if (unlikely(order
>= MAX_ORDER
)) {
4871 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
4875 gfp_mask
&= gfp_allowed_mask
;
4876 alloc_mask
= gfp_mask
;
4877 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4881 * Forbid the first pass from falling back to types that fragment
4882 * memory until all local zones are considered.
4884 alloc_flags
|= alloc_flags_nofragment(ac
.preferred_zoneref
->zone
, gfp_mask
);
4886 /* First allocation attempt */
4887 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4892 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4893 * resp. GFP_NOIO which has to be inherited for all allocation requests
4894 * from a particular context which has been marked by
4895 * memalloc_no{fs,io}_{save,restore}.
4897 alloc_mask
= current_gfp_context(gfp_mask
);
4898 ac
.spread_dirty_pages
= false;
4901 * Restore the original nodemask if it was potentially replaced with
4902 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4904 ac
.nodemask
= nodemask
;
4906 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4909 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4910 unlikely(__memcg_kmem_charge_page(page
, gfp_mask
, order
) != 0)) {
4911 __free_pages(page
, order
);
4915 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4919 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4922 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
4923 * address cannot represent highmem pages. Use alloc_pages and then kmap if
4924 * you need to access high mem.
4926 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4930 page
= alloc_pages(gfp_mask
& ~__GFP_HIGHMEM
, order
);
4933 return (unsigned long) page_address(page
);
4935 EXPORT_SYMBOL(__get_free_pages
);
4937 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4939 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4941 EXPORT_SYMBOL(get_zeroed_page
);
4943 static inline void free_the_page(struct page
*page
, unsigned int order
)
4945 if (order
== 0) /* Via pcp? */
4946 free_unref_page(page
);
4948 __free_pages_ok(page
, order
);
4951 void __free_pages(struct page
*page
, unsigned int order
)
4953 if (put_page_testzero(page
))
4954 free_the_page(page
, order
);
4955 else if (!PageHead(page
))
4957 free_the_page(page
+ (1 << order
), order
);
4959 EXPORT_SYMBOL(__free_pages
);
4961 void free_pages(unsigned long addr
, unsigned int order
)
4964 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4965 __free_pages(virt_to_page((void *)addr
), order
);
4969 EXPORT_SYMBOL(free_pages
);
4973 * An arbitrary-length arbitrary-offset area of memory which resides
4974 * within a 0 or higher order page. Multiple fragments within that page
4975 * are individually refcounted, in the page's reference counter.
4977 * The page_frag functions below provide a simple allocation framework for
4978 * page fragments. This is used by the network stack and network device
4979 * drivers to provide a backing region of memory for use as either an
4980 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4982 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4985 struct page
*page
= NULL
;
4986 gfp_t gfp
= gfp_mask
;
4988 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4989 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4991 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4992 PAGE_FRAG_CACHE_MAX_ORDER
);
4993 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4995 if (unlikely(!page
))
4996 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4998 nc
->va
= page
? page_address(page
) : NULL
;
5003 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
5005 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
5007 if (page_ref_sub_and_test(page
, count
))
5008 free_the_page(page
, compound_order(page
));
5010 EXPORT_SYMBOL(__page_frag_cache_drain
);
5012 void *page_frag_alloc(struct page_frag_cache
*nc
,
5013 unsigned int fragsz
, gfp_t gfp_mask
)
5015 unsigned int size
= PAGE_SIZE
;
5019 if (unlikely(!nc
->va
)) {
5021 page
= __page_frag_cache_refill(nc
, gfp_mask
);
5025 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5026 /* if size can vary use size else just use PAGE_SIZE */
5029 /* Even if we own the page, we do not use atomic_set().
5030 * This would break get_page_unless_zero() users.
5032 page_ref_add(page
, PAGE_FRAG_CACHE_MAX_SIZE
);
5034 /* reset page count bias and offset to start of new frag */
5035 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
5036 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5040 offset
= nc
->offset
- fragsz
;
5041 if (unlikely(offset
< 0)) {
5042 page
= virt_to_page(nc
->va
);
5044 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
5047 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5048 /* if size can vary use size else just use PAGE_SIZE */
5051 /* OK, page count is 0, we can safely set it */
5052 set_page_count(page
, PAGE_FRAG_CACHE_MAX_SIZE
+ 1);
5054 /* reset page count bias and offset to start of new frag */
5055 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5056 offset
= size
- fragsz
;
5060 nc
->offset
= offset
;
5062 return nc
->va
+ offset
;
5064 EXPORT_SYMBOL(page_frag_alloc
);
5067 * Frees a page fragment allocated out of either a compound or order 0 page.
5069 void page_frag_free(void *addr
)
5071 struct page
*page
= virt_to_head_page(addr
);
5073 if (unlikely(put_page_testzero(page
)))
5074 free_the_page(page
, compound_order(page
));
5076 EXPORT_SYMBOL(page_frag_free
);
5078 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
5082 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
5083 unsigned long used
= addr
+ PAGE_ALIGN(size
);
5085 split_page(virt_to_page((void *)addr
), order
);
5086 while (used
< alloc_end
) {
5091 return (void *)addr
;
5095 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5096 * @size: the number of bytes to allocate
5097 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5099 * This function is similar to alloc_pages(), except that it allocates the
5100 * minimum number of pages to satisfy the request. alloc_pages() can only
5101 * allocate memory in power-of-two pages.
5103 * This function is also limited by MAX_ORDER.
5105 * Memory allocated by this function must be released by free_pages_exact().
5107 * Return: pointer to the allocated area or %NULL in case of error.
5109 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
5111 unsigned int order
= get_order(size
);
5114 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5115 gfp_mask
&= ~__GFP_COMP
;
5117 addr
= __get_free_pages(gfp_mask
, order
);
5118 return make_alloc_exact(addr
, order
, size
);
5120 EXPORT_SYMBOL(alloc_pages_exact
);
5123 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5125 * @nid: the preferred node ID where memory should be allocated
5126 * @size: the number of bytes to allocate
5127 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5129 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5132 * Return: pointer to the allocated area or %NULL in case of error.
5134 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
5136 unsigned int order
= get_order(size
);
5139 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5140 gfp_mask
&= ~__GFP_COMP
;
5142 p
= alloc_pages_node(nid
, gfp_mask
, order
);
5145 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
5149 * free_pages_exact - release memory allocated via alloc_pages_exact()
5150 * @virt: the value returned by alloc_pages_exact.
5151 * @size: size of allocation, same value as passed to alloc_pages_exact().
5153 * Release the memory allocated by a previous call to alloc_pages_exact.
5155 void free_pages_exact(void *virt
, size_t size
)
5157 unsigned long addr
= (unsigned long)virt
;
5158 unsigned long end
= addr
+ PAGE_ALIGN(size
);
5160 while (addr
< end
) {
5165 EXPORT_SYMBOL(free_pages_exact
);
5168 * nr_free_zone_pages - count number of pages beyond high watermark
5169 * @offset: The zone index of the highest zone
5171 * nr_free_zone_pages() counts the number of pages which are beyond the
5172 * high watermark within all zones at or below a given zone index. For each
5173 * zone, the number of pages is calculated as:
5175 * nr_free_zone_pages = managed_pages - high_pages
5177 * Return: number of pages beyond high watermark.
5179 static unsigned long nr_free_zone_pages(int offset
)
5184 /* Just pick one node, since fallback list is circular */
5185 unsigned long sum
= 0;
5187 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
5189 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
5190 unsigned long size
= zone_managed_pages(zone
);
5191 unsigned long high
= high_wmark_pages(zone
);
5200 * nr_free_buffer_pages - count number of pages beyond high watermark
5202 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5203 * watermark within ZONE_DMA and ZONE_NORMAL.
5205 * Return: number of pages beyond high watermark within ZONE_DMA and
5208 unsigned long nr_free_buffer_pages(void)
5210 return nr_free_zone_pages(gfp_zone(GFP_USER
));
5212 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
5214 static inline void show_node(struct zone
*zone
)
5216 if (IS_ENABLED(CONFIG_NUMA
))
5217 printk("Node %d ", zone_to_nid(zone
));
5220 long si_mem_available(void)
5223 unsigned long pagecache
;
5224 unsigned long wmark_low
= 0;
5225 unsigned long pages
[NR_LRU_LISTS
];
5226 unsigned long reclaimable
;
5230 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
5231 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
5234 wmark_low
+= low_wmark_pages(zone
);
5237 * Estimate the amount of memory available for userspace allocations,
5238 * without causing swapping.
5240 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
5243 * Not all the page cache can be freed, otherwise the system will
5244 * start swapping. Assume at least half of the page cache, or the
5245 * low watermark worth of cache, needs to stay.
5247 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
5248 pagecache
-= min(pagecache
/ 2, wmark_low
);
5249 available
+= pagecache
;
5252 * Part of the reclaimable slab and other kernel memory consists of
5253 * items that are in use, and cannot be freed. Cap this estimate at the
5256 reclaimable
= global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
) +
5257 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE
);
5258 available
+= reclaimable
- min(reclaimable
/ 2, wmark_low
);
5264 EXPORT_SYMBOL_GPL(si_mem_available
);
5266 void si_meminfo(struct sysinfo
*val
)
5268 val
->totalram
= totalram_pages();
5269 val
->sharedram
= global_node_page_state(NR_SHMEM
);
5270 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
5271 val
->bufferram
= nr_blockdev_pages();
5272 val
->totalhigh
= totalhigh_pages();
5273 val
->freehigh
= nr_free_highpages();
5274 val
->mem_unit
= PAGE_SIZE
;
5277 EXPORT_SYMBOL(si_meminfo
);
5280 void si_meminfo_node(struct sysinfo
*val
, int nid
)
5282 int zone_type
; /* needs to be signed */
5283 unsigned long managed_pages
= 0;
5284 unsigned long managed_highpages
= 0;
5285 unsigned long free_highpages
= 0;
5286 pg_data_t
*pgdat
= NODE_DATA(nid
);
5288 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
5289 managed_pages
+= zone_managed_pages(&pgdat
->node_zones
[zone_type
]);
5290 val
->totalram
= managed_pages
;
5291 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
5292 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
5293 #ifdef CONFIG_HIGHMEM
5294 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
5295 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5297 if (is_highmem(zone
)) {
5298 managed_highpages
+= zone_managed_pages(zone
);
5299 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
5302 val
->totalhigh
= managed_highpages
;
5303 val
->freehigh
= free_highpages
;
5305 val
->totalhigh
= managed_highpages
;
5306 val
->freehigh
= free_highpages
;
5308 val
->mem_unit
= PAGE_SIZE
;
5313 * Determine whether the node should be displayed or not, depending on whether
5314 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5316 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
5318 if (!(flags
& SHOW_MEM_FILTER_NODES
))
5322 * no node mask - aka implicit memory numa policy. Do not bother with
5323 * the synchronization - read_mems_allowed_begin - because we do not
5324 * have to be precise here.
5327 nodemask
= &cpuset_current_mems_allowed
;
5329 return !node_isset(nid
, *nodemask
);
5332 #define K(x) ((x) << (PAGE_SHIFT-10))
5334 static void show_migration_types(unsigned char type
)
5336 static const char types
[MIGRATE_TYPES
] = {
5337 [MIGRATE_UNMOVABLE
] = 'U',
5338 [MIGRATE_MOVABLE
] = 'M',
5339 [MIGRATE_RECLAIMABLE
] = 'E',
5340 [MIGRATE_HIGHATOMIC
] = 'H',
5342 [MIGRATE_CMA
] = 'C',
5344 #ifdef CONFIG_MEMORY_ISOLATION
5345 [MIGRATE_ISOLATE
] = 'I',
5348 char tmp
[MIGRATE_TYPES
+ 1];
5352 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
5353 if (type
& (1 << i
))
5358 printk(KERN_CONT
"(%s) ", tmp
);
5362 * Show free area list (used inside shift_scroll-lock stuff)
5363 * We also calculate the percentage fragmentation. We do this by counting the
5364 * memory on each free list with the exception of the first item on the list.
5367 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5370 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
5372 unsigned long free_pcp
= 0;
5377 for_each_populated_zone(zone
) {
5378 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5381 for_each_online_cpu(cpu
)
5382 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5385 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5386 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5387 " unevictable:%lu dirty:%lu writeback:%lu\n"
5388 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5389 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5390 " free:%lu free_pcp:%lu free_cma:%lu\n",
5391 global_node_page_state(NR_ACTIVE_ANON
),
5392 global_node_page_state(NR_INACTIVE_ANON
),
5393 global_node_page_state(NR_ISOLATED_ANON
),
5394 global_node_page_state(NR_ACTIVE_FILE
),
5395 global_node_page_state(NR_INACTIVE_FILE
),
5396 global_node_page_state(NR_ISOLATED_FILE
),
5397 global_node_page_state(NR_UNEVICTABLE
),
5398 global_node_page_state(NR_FILE_DIRTY
),
5399 global_node_page_state(NR_WRITEBACK
),
5400 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
),
5401 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B
),
5402 global_node_page_state(NR_FILE_MAPPED
),
5403 global_node_page_state(NR_SHMEM
),
5404 global_zone_page_state(NR_PAGETABLE
),
5405 global_zone_page_state(NR_BOUNCE
),
5406 global_zone_page_state(NR_FREE_PAGES
),
5408 global_zone_page_state(NR_FREE_CMA_PAGES
));
5410 for_each_online_pgdat(pgdat
) {
5411 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
5415 " active_anon:%lukB"
5416 " inactive_anon:%lukB"
5417 " active_file:%lukB"
5418 " inactive_file:%lukB"
5419 " unevictable:%lukB"
5420 " isolated(anon):%lukB"
5421 " isolated(file):%lukB"
5426 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5428 " shmem_pmdmapped: %lukB"
5431 " writeback_tmp:%lukB"
5432 " kernel_stack:%lukB"
5433 #ifdef CONFIG_SHADOW_CALL_STACK
5434 " shadow_call_stack:%lukB"
5436 " all_unreclaimable? %s"
5439 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
5440 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
5441 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
5442 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
5443 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
5444 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
5445 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
5446 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
5447 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
5448 K(node_page_state(pgdat
, NR_WRITEBACK
)),
5449 K(node_page_state(pgdat
, NR_SHMEM
)),
5450 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5451 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
5452 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
5454 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
5456 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
5457 node_page_state(pgdat
, NR_KERNEL_STACK_KB
),
5458 #ifdef CONFIG_SHADOW_CALL_STACK
5459 node_page_state(pgdat
, NR_KERNEL_SCS_KB
),
5461 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
5465 for_each_populated_zone(zone
) {
5468 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5472 for_each_online_cpu(cpu
)
5473 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5482 " reserved_highatomic:%luKB"
5483 " active_anon:%lukB"
5484 " inactive_anon:%lukB"
5485 " active_file:%lukB"
5486 " inactive_file:%lukB"
5487 " unevictable:%lukB"
5488 " writepending:%lukB"
5499 K(zone_page_state(zone
, NR_FREE_PAGES
)),
5500 K(min_wmark_pages(zone
)),
5501 K(low_wmark_pages(zone
)),
5502 K(high_wmark_pages(zone
)),
5503 K(zone
->nr_reserved_highatomic
),
5504 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
5505 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
5506 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
5507 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
5508 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
5509 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
5510 K(zone
->present_pages
),
5511 K(zone_managed_pages(zone
)),
5512 K(zone_page_state(zone
, NR_MLOCK
)),
5513 K(zone_page_state(zone
, NR_PAGETABLE
)),
5514 K(zone_page_state(zone
, NR_BOUNCE
)),
5516 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
5517 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
5518 printk("lowmem_reserve[]:");
5519 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
5520 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
5521 printk(KERN_CONT
"\n");
5524 for_each_populated_zone(zone
) {
5526 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
5527 unsigned char types
[MAX_ORDER
];
5529 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5532 printk(KERN_CONT
"%s: ", zone
->name
);
5534 spin_lock_irqsave(&zone
->lock
, flags
);
5535 for (order
= 0; order
< MAX_ORDER
; order
++) {
5536 struct free_area
*area
= &zone
->free_area
[order
];
5539 nr
[order
] = area
->nr_free
;
5540 total
+= nr
[order
] << order
;
5543 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
5544 if (!free_area_empty(area
, type
))
5545 types
[order
] |= 1 << type
;
5548 spin_unlock_irqrestore(&zone
->lock
, flags
);
5549 for (order
= 0; order
< MAX_ORDER
; order
++) {
5550 printk(KERN_CONT
"%lu*%lukB ",
5551 nr
[order
], K(1UL) << order
);
5553 show_migration_types(types
[order
]);
5555 printk(KERN_CONT
"= %lukB\n", K(total
));
5558 hugetlb_show_meminfo();
5560 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
5562 show_swap_cache_info();
5565 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
5567 zoneref
->zone
= zone
;
5568 zoneref
->zone_idx
= zone_idx(zone
);
5572 * Builds allocation fallback zone lists.
5574 * Add all populated zones of a node to the zonelist.
5576 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
5579 enum zone_type zone_type
= MAX_NR_ZONES
;
5584 zone
= pgdat
->node_zones
+ zone_type
;
5585 if (managed_zone(zone
)) {
5586 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
5587 check_highest_zone(zone_type
);
5589 } while (zone_type
);
5596 static int __parse_numa_zonelist_order(char *s
)
5599 * We used to support different zonlists modes but they turned
5600 * out to be just not useful. Let's keep the warning in place
5601 * if somebody still use the cmd line parameter so that we do
5602 * not fail it silently
5604 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
5605 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
5611 char numa_zonelist_order
[] = "Node";
5614 * sysctl handler for numa_zonelist_order
5616 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
5617 void *buffer
, size_t *length
, loff_t
*ppos
)
5620 return __parse_numa_zonelist_order(buffer
);
5621 return proc_dostring(table
, write
, buffer
, length
, ppos
);
5625 #define MAX_NODE_LOAD (nr_online_nodes)
5626 static int node_load
[MAX_NUMNODES
];
5629 * find_next_best_node - find the next node that should appear in a given node's fallback list
5630 * @node: node whose fallback list we're appending
5631 * @used_node_mask: nodemask_t of already used nodes
5633 * We use a number of factors to determine which is the next node that should
5634 * appear on a given node's fallback list. The node should not have appeared
5635 * already in @node's fallback list, and it should be the next closest node
5636 * according to the distance array (which contains arbitrary distance values
5637 * from each node to each node in the system), and should also prefer nodes
5638 * with no CPUs, since presumably they'll have very little allocation pressure
5639 * on them otherwise.
5641 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5643 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
5646 int min_val
= INT_MAX
;
5647 int best_node
= NUMA_NO_NODE
;
5649 /* Use the local node if we haven't already */
5650 if (!node_isset(node
, *used_node_mask
)) {
5651 node_set(node
, *used_node_mask
);
5655 for_each_node_state(n
, N_MEMORY
) {
5657 /* Don't want a node to appear more than once */
5658 if (node_isset(n
, *used_node_mask
))
5661 /* Use the distance array to find the distance */
5662 val
= node_distance(node
, n
);
5664 /* Penalize nodes under us ("prefer the next node") */
5667 /* Give preference to headless and unused nodes */
5668 if (!cpumask_empty(cpumask_of_node(n
)))
5669 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
5671 /* Slight preference for less loaded node */
5672 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
5673 val
+= node_load
[n
];
5675 if (val
< min_val
) {
5682 node_set(best_node
, *used_node_mask
);
5689 * Build zonelists ordered by node and zones within node.
5690 * This results in maximum locality--normal zone overflows into local
5691 * DMA zone, if any--but risks exhausting DMA zone.
5693 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5696 struct zoneref
*zonerefs
;
5699 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5701 for (i
= 0; i
< nr_nodes
; i
++) {
5704 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5706 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5707 zonerefs
+= nr_zones
;
5709 zonerefs
->zone
= NULL
;
5710 zonerefs
->zone_idx
= 0;
5714 * Build gfp_thisnode zonelists
5716 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5718 struct zoneref
*zonerefs
;
5721 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5722 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5723 zonerefs
+= nr_zones
;
5724 zonerefs
->zone
= NULL
;
5725 zonerefs
->zone_idx
= 0;
5729 * Build zonelists ordered by zone and nodes within zones.
5730 * This results in conserving DMA zone[s] until all Normal memory is
5731 * exhausted, but results in overflowing to remote node while memory
5732 * may still exist in local DMA zone.
5735 static void build_zonelists(pg_data_t
*pgdat
)
5737 static int node_order
[MAX_NUMNODES
];
5738 int node
, load
, nr_nodes
= 0;
5739 nodemask_t used_mask
= NODE_MASK_NONE
;
5740 int local_node
, prev_node
;
5742 /* NUMA-aware ordering of nodes */
5743 local_node
= pgdat
->node_id
;
5744 load
= nr_online_nodes
;
5745 prev_node
= local_node
;
5747 memset(node_order
, 0, sizeof(node_order
));
5748 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5750 * We don't want to pressure a particular node.
5751 * So adding penalty to the first node in same
5752 * distance group to make it round-robin.
5754 if (node_distance(local_node
, node
) !=
5755 node_distance(local_node
, prev_node
))
5756 node_load
[node
] = load
;
5758 node_order
[nr_nodes
++] = node
;
5763 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5764 build_thisnode_zonelists(pgdat
);
5767 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5769 * Return node id of node used for "local" allocations.
5770 * I.e., first node id of first zone in arg node's generic zonelist.
5771 * Used for initializing percpu 'numa_mem', which is used primarily
5772 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5774 int local_memory_node(int node
)
5778 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5779 gfp_zone(GFP_KERNEL
),
5781 return zone_to_nid(z
->zone
);
5785 static void setup_min_unmapped_ratio(void);
5786 static void setup_min_slab_ratio(void);
5787 #else /* CONFIG_NUMA */
5789 static void build_zonelists(pg_data_t
*pgdat
)
5791 int node
, local_node
;
5792 struct zoneref
*zonerefs
;
5795 local_node
= pgdat
->node_id
;
5797 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5798 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5799 zonerefs
+= nr_zones
;
5802 * Now we build the zonelist so that it contains the zones
5803 * of all the other nodes.
5804 * We don't want to pressure a particular node, so when
5805 * building the zones for node N, we make sure that the
5806 * zones coming right after the local ones are those from
5807 * node N+1 (modulo N)
5809 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5810 if (!node_online(node
))
5812 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5813 zonerefs
+= nr_zones
;
5815 for (node
= 0; node
< local_node
; node
++) {
5816 if (!node_online(node
))
5818 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5819 zonerefs
+= nr_zones
;
5822 zonerefs
->zone
= NULL
;
5823 zonerefs
->zone_idx
= 0;
5826 #endif /* CONFIG_NUMA */
5829 * Boot pageset table. One per cpu which is going to be used for all
5830 * zones and all nodes. The parameters will be set in such a way
5831 * that an item put on a list will immediately be handed over to
5832 * the buddy list. This is safe since pageset manipulation is done
5833 * with interrupts disabled.
5835 * The boot_pagesets must be kept even after bootup is complete for
5836 * unused processors and/or zones. They do play a role for bootstrapping
5837 * hotplugged processors.
5839 * zoneinfo_show() and maybe other functions do
5840 * not check if the processor is online before following the pageset pointer.
5841 * Other parts of the kernel may not check if the zone is available.
5843 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5844 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5845 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5847 static void __build_all_zonelists(void *data
)
5850 int __maybe_unused cpu
;
5851 pg_data_t
*self
= data
;
5852 static DEFINE_SPINLOCK(lock
);
5857 memset(node_load
, 0, sizeof(node_load
));
5861 * This node is hotadded and no memory is yet present. So just
5862 * building zonelists is fine - no need to touch other nodes.
5864 if (self
&& !node_online(self
->node_id
)) {
5865 build_zonelists(self
);
5867 for_each_online_node(nid
) {
5868 pg_data_t
*pgdat
= NODE_DATA(nid
);
5870 build_zonelists(pgdat
);
5873 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5875 * We now know the "local memory node" for each node--
5876 * i.e., the node of the first zone in the generic zonelist.
5877 * Set up numa_mem percpu variable for on-line cpus. During
5878 * boot, only the boot cpu should be on-line; we'll init the
5879 * secondary cpus' numa_mem as they come on-line. During
5880 * node/memory hotplug, we'll fixup all on-line cpus.
5882 for_each_online_cpu(cpu
)
5883 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5890 static noinline
void __init
5891 build_all_zonelists_init(void)
5895 __build_all_zonelists(NULL
);
5898 * Initialize the boot_pagesets that are going to be used
5899 * for bootstrapping processors. The real pagesets for
5900 * each zone will be allocated later when the per cpu
5901 * allocator is available.
5903 * boot_pagesets are used also for bootstrapping offline
5904 * cpus if the system is already booted because the pagesets
5905 * are needed to initialize allocators on a specific cpu too.
5906 * F.e. the percpu allocator needs the page allocator which
5907 * needs the percpu allocator in order to allocate its pagesets
5908 * (a chicken-egg dilemma).
5910 for_each_possible_cpu(cpu
)
5911 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5913 mminit_verify_zonelist();
5914 cpuset_init_current_mems_allowed();
5918 * unless system_state == SYSTEM_BOOTING.
5920 * __ref due to call of __init annotated helper build_all_zonelists_init
5921 * [protected by SYSTEM_BOOTING].
5923 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
5925 unsigned long vm_total_pages
;
5927 if (system_state
== SYSTEM_BOOTING
) {
5928 build_all_zonelists_init();
5930 __build_all_zonelists(pgdat
);
5931 /* cpuset refresh routine should be here */
5933 /* Get the number of free pages beyond high watermark in all zones. */
5934 vm_total_pages
= nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
5936 * Disable grouping by mobility if the number of pages in the
5937 * system is too low to allow the mechanism to work. It would be
5938 * more accurate, but expensive to check per-zone. This check is
5939 * made on memory-hotadd so a system can start with mobility
5940 * disabled and enable it later
5942 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5943 page_group_by_mobility_disabled
= 1;
5945 page_group_by_mobility_disabled
= 0;
5947 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
5949 page_group_by_mobility_disabled
? "off" : "on",
5952 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5956 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
5957 static bool __meminit
5958 overlap_memmap_init(unsigned long zone
, unsigned long *pfn
)
5960 static struct memblock_region
*r
;
5962 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5963 if (!r
|| *pfn
>= memblock_region_memory_end_pfn(r
)) {
5964 for_each_mem_region(r
) {
5965 if (*pfn
< memblock_region_memory_end_pfn(r
))
5969 if (*pfn
>= memblock_region_memory_base_pfn(r
) &&
5970 memblock_is_mirror(r
)) {
5971 *pfn
= memblock_region_memory_end_pfn(r
);
5979 * Initially all pages are reserved - free ones are freed
5980 * up by memblock_free_all() once the early boot process is
5981 * done. Non-atomic initialization, single-pass.
5983 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5984 unsigned long start_pfn
, enum meminit_context context
,
5985 struct vmem_altmap
*altmap
)
5987 unsigned long pfn
, end_pfn
= start_pfn
+ size
;
5990 if (highest_memmap_pfn
< end_pfn
- 1)
5991 highest_memmap_pfn
= end_pfn
- 1;
5993 #ifdef CONFIG_ZONE_DEVICE
5995 * Honor reservation requested by the driver for this ZONE_DEVICE
5996 * memory. We limit the total number of pages to initialize to just
5997 * those that might contain the memory mapping. We will defer the
5998 * ZONE_DEVICE page initialization until after we have released
6001 if (zone
== ZONE_DEVICE
) {
6005 if (start_pfn
== altmap
->base_pfn
)
6006 start_pfn
+= altmap
->reserve
;
6007 end_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6011 for (pfn
= start_pfn
; pfn
< end_pfn
; ) {
6013 * There can be holes in boot-time mem_map[]s handed to this
6014 * function. They do not exist on hotplugged memory.
6016 if (context
== MEMINIT_EARLY
) {
6017 if (overlap_memmap_init(zone
, &pfn
))
6019 if (defer_init(nid
, pfn
, end_pfn
))
6023 page
= pfn_to_page(pfn
);
6024 __init_single_page(page
, pfn
, zone
, nid
);
6025 if (context
== MEMINIT_HOTPLUG
)
6026 __SetPageReserved(page
);
6029 * Mark the block movable so that blocks are reserved for
6030 * movable at startup. This will force kernel allocations
6031 * to reserve their blocks rather than leaking throughout
6032 * the address space during boot when many long-lived
6033 * kernel allocations are made.
6035 * bitmap is created for zone's valid pfn range. but memmap
6036 * can be created for invalid pages (for alignment)
6037 * check here not to call set_pageblock_migratetype() against
6040 if (!(pfn
& (pageblock_nr_pages
- 1))) {
6041 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
6048 #ifdef CONFIG_ZONE_DEVICE
6049 void __ref
memmap_init_zone_device(struct zone
*zone
,
6050 unsigned long start_pfn
,
6051 unsigned long nr_pages
,
6052 struct dev_pagemap
*pgmap
)
6054 unsigned long pfn
, end_pfn
= start_pfn
+ nr_pages
;
6055 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6056 struct vmem_altmap
*altmap
= pgmap_altmap(pgmap
);
6057 unsigned long zone_idx
= zone_idx(zone
);
6058 unsigned long start
= jiffies
;
6059 int nid
= pgdat
->node_id
;
6061 if (WARN_ON_ONCE(!pgmap
|| zone_idx(zone
) != ZONE_DEVICE
))
6065 * The call to memmap_init_zone should have already taken care
6066 * of the pages reserved for the memmap, so we can just jump to
6067 * the end of that region and start processing the device pages.
6070 start_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6071 nr_pages
= end_pfn
- start_pfn
;
6074 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
6075 struct page
*page
= pfn_to_page(pfn
);
6077 __init_single_page(page
, pfn
, zone_idx
, nid
);
6080 * Mark page reserved as it will need to wait for onlining
6081 * phase for it to be fully associated with a zone.
6083 * We can use the non-atomic __set_bit operation for setting
6084 * the flag as we are still initializing the pages.
6086 __SetPageReserved(page
);
6089 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6090 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6091 * ever freed or placed on a driver-private list.
6093 page
->pgmap
= pgmap
;
6094 page
->zone_device_data
= NULL
;
6097 * Mark the block movable so that blocks are reserved for
6098 * movable at startup. This will force kernel allocations
6099 * to reserve their blocks rather than leaking throughout
6100 * the address space during boot when many long-lived
6101 * kernel allocations are made.
6103 * bitmap is created for zone's valid pfn range. but memmap
6104 * can be created for invalid pages (for alignment)
6105 * check here not to call set_pageblock_migratetype() against
6108 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6109 * because this is done early in section_activate()
6111 if (!(pfn
& (pageblock_nr_pages
- 1))) {
6112 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
6117 pr_info("%s initialised %lu pages in %ums\n", __func__
,
6118 nr_pages
, jiffies_to_msecs(jiffies
- start
));
6122 static void __meminit
zone_init_free_lists(struct zone
*zone
)
6124 unsigned int order
, t
;
6125 for_each_migratetype_order(order
, t
) {
6126 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
6127 zone
->free_area
[order
].nr_free
= 0;
6131 void __meminit __weak
memmap_init(unsigned long size
, int nid
,
6133 unsigned long range_start_pfn
)
6135 unsigned long start_pfn
, end_pfn
;
6136 unsigned long range_end_pfn
= range_start_pfn
+ size
;
6139 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6140 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6141 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6143 if (end_pfn
> start_pfn
) {
6144 size
= end_pfn
- start_pfn
;
6145 memmap_init_zone(size
, nid
, zone
, start_pfn
,
6146 MEMINIT_EARLY
, NULL
);
6151 static int zone_batchsize(struct zone
*zone
)
6157 * The per-cpu-pages pools are set to around 1000th of the
6160 batch
= zone_managed_pages(zone
) / 1024;
6161 /* But no more than a meg. */
6162 if (batch
* PAGE_SIZE
> 1024 * 1024)
6163 batch
= (1024 * 1024) / PAGE_SIZE
;
6164 batch
/= 4; /* We effectively *= 4 below */
6169 * Clamp the batch to a 2^n - 1 value. Having a power
6170 * of 2 value was found to be more likely to have
6171 * suboptimal cache aliasing properties in some cases.
6173 * For example if 2 tasks are alternately allocating
6174 * batches of pages, one task can end up with a lot
6175 * of pages of one half of the possible page colors
6176 * and the other with pages of the other colors.
6178 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
6183 /* The deferral and batching of frees should be suppressed under NOMMU
6186 * The problem is that NOMMU needs to be able to allocate large chunks
6187 * of contiguous memory as there's no hardware page translation to
6188 * assemble apparent contiguous memory from discontiguous pages.
6190 * Queueing large contiguous runs of pages for batching, however,
6191 * causes the pages to actually be freed in smaller chunks. As there
6192 * can be a significant delay between the individual batches being
6193 * recycled, this leads to the once large chunks of space being
6194 * fragmented and becoming unavailable for high-order allocations.
6201 * pcp->high and pcp->batch values are related and dependent on one another:
6202 * ->batch must never be higher then ->high.
6203 * The following function updates them in a safe manner without read side
6206 * Any new users of pcp->batch and pcp->high should ensure they can cope with
6207 * those fields changing asynchronously (acording to the above rule).
6209 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6210 * outside of boot time (or some other assurance that no concurrent updaters
6213 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
6214 unsigned long batch
)
6216 /* start with a fail safe value for batch */
6220 /* Update high, then batch, in order */
6227 /* a companion to pageset_set_high() */
6228 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
6230 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
6233 static void pageset_init(struct per_cpu_pageset
*p
)
6235 struct per_cpu_pages
*pcp
;
6238 memset(p
, 0, sizeof(*p
));
6241 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
6242 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
6245 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
6248 pageset_set_batch(p
, batch
);
6252 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
6253 * to the value high for the pageset p.
6255 static void pageset_set_high(struct per_cpu_pageset
*p
,
6258 unsigned long batch
= max(1UL, high
/ 4);
6259 if ((high
/ 4) > (PAGE_SHIFT
* 8))
6260 batch
= PAGE_SHIFT
* 8;
6262 pageset_update(&p
->pcp
, high
, batch
);
6265 static void pageset_set_high_and_batch(struct zone
*zone
,
6266 struct per_cpu_pageset
*pcp
)
6268 if (percpu_pagelist_fraction
)
6269 pageset_set_high(pcp
,
6270 (zone_managed_pages(zone
) /
6271 percpu_pagelist_fraction
));
6273 pageset_set_batch(pcp
, zone_batchsize(zone
));
6276 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
6278 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
6281 pageset_set_high_and_batch(zone
, pcp
);
6284 void __meminit
setup_zone_pageset(struct zone
*zone
)
6287 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
6288 for_each_possible_cpu(cpu
)
6289 zone_pageset_init(zone
, cpu
);
6293 * Allocate per cpu pagesets and initialize them.
6294 * Before this call only boot pagesets were available.
6296 void __init
setup_per_cpu_pageset(void)
6298 struct pglist_data
*pgdat
;
6300 int __maybe_unused cpu
;
6302 for_each_populated_zone(zone
)
6303 setup_zone_pageset(zone
);
6307 * Unpopulated zones continue using the boot pagesets.
6308 * The numa stats for these pagesets need to be reset.
6309 * Otherwise, they will end up skewing the stats of
6310 * the nodes these zones are associated with.
6312 for_each_possible_cpu(cpu
) {
6313 struct per_cpu_pageset
*pcp
= &per_cpu(boot_pageset
, cpu
);
6314 memset(pcp
->vm_numa_stat_diff
, 0,
6315 sizeof(pcp
->vm_numa_stat_diff
));
6319 for_each_online_pgdat(pgdat
)
6320 pgdat
->per_cpu_nodestats
=
6321 alloc_percpu(struct per_cpu_nodestat
);
6324 static __meminit
void zone_pcp_init(struct zone
*zone
)
6327 * per cpu subsystem is not up at this point. The following code
6328 * relies on the ability of the linker to provide the
6329 * offset of a (static) per cpu variable into the per cpu area.
6331 zone
->pageset
= &boot_pageset
;
6333 if (populated_zone(zone
))
6334 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
6335 zone
->name
, zone
->present_pages
,
6336 zone_batchsize(zone
));
6339 void __meminit
init_currently_empty_zone(struct zone
*zone
,
6340 unsigned long zone_start_pfn
,
6343 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6344 int zone_idx
= zone_idx(zone
) + 1;
6346 if (zone_idx
> pgdat
->nr_zones
)
6347 pgdat
->nr_zones
= zone_idx
;
6349 zone
->zone_start_pfn
= zone_start_pfn
;
6351 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
6352 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6354 (unsigned long)zone_idx(zone
),
6355 zone_start_pfn
, (zone_start_pfn
+ size
));
6357 zone_init_free_lists(zone
);
6358 zone
->initialized
= 1;
6362 * get_pfn_range_for_nid - Return the start and end page frames for a node
6363 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6364 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6365 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6367 * It returns the start and end page frame of a node based on information
6368 * provided by memblock_set_node(). If called for a node
6369 * with no available memory, a warning is printed and the start and end
6372 void __init
get_pfn_range_for_nid(unsigned int nid
,
6373 unsigned long *start_pfn
, unsigned long *end_pfn
)
6375 unsigned long this_start_pfn
, this_end_pfn
;
6381 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
6382 *start_pfn
= min(*start_pfn
, this_start_pfn
);
6383 *end_pfn
= max(*end_pfn
, this_end_pfn
);
6386 if (*start_pfn
== -1UL)
6391 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6392 * assumption is made that zones within a node are ordered in monotonic
6393 * increasing memory addresses so that the "highest" populated zone is used
6395 static void __init
find_usable_zone_for_movable(void)
6398 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
6399 if (zone_index
== ZONE_MOVABLE
)
6402 if (arch_zone_highest_possible_pfn
[zone_index
] >
6403 arch_zone_lowest_possible_pfn
[zone_index
])
6407 VM_BUG_ON(zone_index
== -1);
6408 movable_zone
= zone_index
;
6412 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6413 * because it is sized independent of architecture. Unlike the other zones,
6414 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6415 * in each node depending on the size of each node and how evenly kernelcore
6416 * is distributed. This helper function adjusts the zone ranges
6417 * provided by the architecture for a given node by using the end of the
6418 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6419 * zones within a node are in order of monotonic increases memory addresses
6421 static void __init
adjust_zone_range_for_zone_movable(int nid
,
6422 unsigned long zone_type
,
6423 unsigned long node_start_pfn
,
6424 unsigned long node_end_pfn
,
6425 unsigned long *zone_start_pfn
,
6426 unsigned long *zone_end_pfn
)
6428 /* Only adjust if ZONE_MOVABLE is on this node */
6429 if (zone_movable_pfn
[nid
]) {
6430 /* Size ZONE_MOVABLE */
6431 if (zone_type
== ZONE_MOVABLE
) {
6432 *zone_start_pfn
= zone_movable_pfn
[nid
];
6433 *zone_end_pfn
= min(node_end_pfn
,
6434 arch_zone_highest_possible_pfn
[movable_zone
]);
6436 /* Adjust for ZONE_MOVABLE starting within this range */
6437 } else if (!mirrored_kernelcore
&&
6438 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
6439 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
6440 *zone_end_pfn
= zone_movable_pfn
[nid
];
6442 /* Check if this whole range is within ZONE_MOVABLE */
6443 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
6444 *zone_start_pfn
= *zone_end_pfn
;
6449 * Return the number of pages a zone spans in a node, including holes
6450 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6452 static unsigned long __init
zone_spanned_pages_in_node(int nid
,
6453 unsigned long zone_type
,
6454 unsigned long node_start_pfn
,
6455 unsigned long node_end_pfn
,
6456 unsigned long *zone_start_pfn
,
6457 unsigned long *zone_end_pfn
)
6459 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6460 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6461 /* When hotadd a new node from cpu_up(), the node should be empty */
6462 if (!node_start_pfn
&& !node_end_pfn
)
6465 /* Get the start and end of the zone */
6466 *zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6467 *zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6468 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6469 node_start_pfn
, node_end_pfn
,
6470 zone_start_pfn
, zone_end_pfn
);
6472 /* Check that this node has pages within the zone's required range */
6473 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
6476 /* Move the zone boundaries inside the node if necessary */
6477 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
6478 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
6480 /* Return the spanned pages */
6481 return *zone_end_pfn
- *zone_start_pfn
;
6485 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6486 * then all holes in the requested range will be accounted for.
6488 unsigned long __init
__absent_pages_in_range(int nid
,
6489 unsigned long range_start_pfn
,
6490 unsigned long range_end_pfn
)
6492 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
6493 unsigned long start_pfn
, end_pfn
;
6496 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6497 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6498 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6499 nr_absent
-= end_pfn
- start_pfn
;
6505 * absent_pages_in_range - Return number of page frames in holes within a range
6506 * @start_pfn: The start PFN to start searching for holes
6507 * @end_pfn: The end PFN to stop searching for holes
6509 * Return: the number of pages frames in memory holes within a range.
6511 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
6512 unsigned long end_pfn
)
6514 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
6517 /* Return the number of page frames in holes in a zone on a node */
6518 static unsigned long __init
zone_absent_pages_in_node(int nid
,
6519 unsigned long zone_type
,
6520 unsigned long node_start_pfn
,
6521 unsigned long node_end_pfn
)
6523 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6524 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6525 unsigned long zone_start_pfn
, zone_end_pfn
;
6526 unsigned long nr_absent
;
6528 /* When hotadd a new node from cpu_up(), the node should be empty */
6529 if (!node_start_pfn
&& !node_end_pfn
)
6532 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6533 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6535 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6536 node_start_pfn
, node_end_pfn
,
6537 &zone_start_pfn
, &zone_end_pfn
);
6538 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
6541 * ZONE_MOVABLE handling.
6542 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6545 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
6546 unsigned long start_pfn
, end_pfn
;
6547 struct memblock_region
*r
;
6549 for_each_mem_region(r
) {
6550 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
6551 zone_start_pfn
, zone_end_pfn
);
6552 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
6553 zone_start_pfn
, zone_end_pfn
);
6555 if (zone_type
== ZONE_MOVABLE
&&
6556 memblock_is_mirror(r
))
6557 nr_absent
+= end_pfn
- start_pfn
;
6559 if (zone_type
== ZONE_NORMAL
&&
6560 !memblock_is_mirror(r
))
6561 nr_absent
+= end_pfn
- start_pfn
;
6568 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
6569 unsigned long node_start_pfn
,
6570 unsigned long node_end_pfn
)
6572 unsigned long realtotalpages
= 0, totalpages
= 0;
6575 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6576 struct zone
*zone
= pgdat
->node_zones
+ i
;
6577 unsigned long zone_start_pfn
, zone_end_pfn
;
6578 unsigned long spanned
, absent
;
6579 unsigned long size
, real_size
;
6581 spanned
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
6586 absent
= zone_absent_pages_in_node(pgdat
->node_id
, i
,
6591 real_size
= size
- absent
;
6594 zone
->zone_start_pfn
= zone_start_pfn
;
6596 zone
->zone_start_pfn
= 0;
6597 zone
->spanned_pages
= size
;
6598 zone
->present_pages
= real_size
;
6601 realtotalpages
+= real_size
;
6604 pgdat
->node_spanned_pages
= totalpages
;
6605 pgdat
->node_present_pages
= realtotalpages
;
6606 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
6610 #ifndef CONFIG_SPARSEMEM
6612 * Calculate the size of the zone->blockflags rounded to an unsigned long
6613 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6614 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6615 * round what is now in bits to nearest long in bits, then return it in
6618 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
6620 unsigned long usemapsize
;
6622 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
6623 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
6624 usemapsize
= usemapsize
>> pageblock_order
;
6625 usemapsize
*= NR_PAGEBLOCK_BITS
;
6626 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
6628 return usemapsize
/ 8;
6631 static void __ref
setup_usemap(struct pglist_data
*pgdat
,
6633 unsigned long zone_start_pfn
,
6634 unsigned long zonesize
)
6636 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
6637 zone
->pageblock_flags
= NULL
;
6639 zone
->pageblock_flags
=
6640 memblock_alloc_node(usemapsize
, SMP_CACHE_BYTES
,
6642 if (!zone
->pageblock_flags
)
6643 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6644 usemapsize
, zone
->name
, pgdat
->node_id
);
6648 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
6649 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
6650 #endif /* CONFIG_SPARSEMEM */
6652 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6654 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6655 void __init
set_pageblock_order(void)
6659 /* Check that pageblock_nr_pages has not already been setup */
6660 if (pageblock_order
)
6663 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6664 order
= HUGETLB_PAGE_ORDER
;
6666 order
= MAX_ORDER
- 1;
6669 * Assume the largest contiguous order of interest is a huge page.
6670 * This value may be variable depending on boot parameters on IA64 and
6673 pageblock_order
= order
;
6675 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6678 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6679 * is unused as pageblock_order is set at compile-time. See
6680 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6683 void __init
set_pageblock_order(void)
6687 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6689 static unsigned long __init
calc_memmap_size(unsigned long spanned_pages
,
6690 unsigned long present_pages
)
6692 unsigned long pages
= spanned_pages
;
6695 * Provide a more accurate estimation if there are holes within
6696 * the zone and SPARSEMEM is in use. If there are holes within the
6697 * zone, each populated memory region may cost us one or two extra
6698 * memmap pages due to alignment because memmap pages for each
6699 * populated regions may not be naturally aligned on page boundary.
6700 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6702 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6703 IS_ENABLED(CONFIG_SPARSEMEM
))
6704 pages
= present_pages
;
6706 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6709 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6710 static void pgdat_init_split_queue(struct pglist_data
*pgdat
)
6712 struct deferred_split
*ds_queue
= &pgdat
->deferred_split_queue
;
6714 spin_lock_init(&ds_queue
->split_queue_lock
);
6715 INIT_LIST_HEAD(&ds_queue
->split_queue
);
6716 ds_queue
->split_queue_len
= 0;
6719 static void pgdat_init_split_queue(struct pglist_data
*pgdat
) {}
6722 #ifdef CONFIG_COMPACTION
6723 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
)
6725 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6728 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
) {}
6731 static void __meminit
pgdat_init_internals(struct pglist_data
*pgdat
)
6733 pgdat_resize_init(pgdat
);
6735 pgdat_init_split_queue(pgdat
);
6736 pgdat_init_kcompactd(pgdat
);
6738 init_waitqueue_head(&pgdat
->kswapd_wait
);
6739 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6741 pgdat_page_ext_init(pgdat
);
6742 spin_lock_init(&pgdat
->lru_lock
);
6743 lruvec_init(&pgdat
->__lruvec
);
6746 static void __meminit
zone_init_internals(struct zone
*zone
, enum zone_type idx
, int nid
,
6747 unsigned long remaining_pages
)
6749 atomic_long_set(&zone
->managed_pages
, remaining_pages
);
6750 zone_set_nid(zone
, nid
);
6751 zone
->name
= zone_names
[idx
];
6752 zone
->zone_pgdat
= NODE_DATA(nid
);
6753 spin_lock_init(&zone
->lock
);
6754 zone_seqlock_init(zone
);
6755 zone_pcp_init(zone
);
6759 * Set up the zone data structures
6760 * - init pgdat internals
6761 * - init all zones belonging to this node
6763 * NOTE: this function is only called during memory hotplug
6765 #ifdef CONFIG_MEMORY_HOTPLUG
6766 void __ref
free_area_init_core_hotplug(int nid
)
6769 pg_data_t
*pgdat
= NODE_DATA(nid
);
6771 pgdat_init_internals(pgdat
);
6772 for (z
= 0; z
< MAX_NR_ZONES
; z
++)
6773 zone_init_internals(&pgdat
->node_zones
[z
], z
, nid
, 0);
6778 * Set up the zone data structures:
6779 * - mark all pages reserved
6780 * - mark all memory queues empty
6781 * - clear the memory bitmaps
6783 * NOTE: pgdat should get zeroed by caller.
6784 * NOTE: this function is only called during early init.
6786 static void __init
free_area_init_core(struct pglist_data
*pgdat
)
6789 int nid
= pgdat
->node_id
;
6791 pgdat_init_internals(pgdat
);
6792 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6794 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6795 struct zone
*zone
= pgdat
->node_zones
+ j
;
6796 unsigned long size
, freesize
, memmap_pages
;
6797 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6799 size
= zone
->spanned_pages
;
6800 freesize
= zone
->present_pages
;
6803 * Adjust freesize so that it accounts for how much memory
6804 * is used by this zone for memmap. This affects the watermark
6805 * and per-cpu initialisations
6807 memmap_pages
= calc_memmap_size(size
, freesize
);
6808 if (!is_highmem_idx(j
)) {
6809 if (freesize
>= memmap_pages
) {
6810 freesize
-= memmap_pages
;
6813 " %s zone: %lu pages used for memmap\n",
6814 zone_names
[j
], memmap_pages
);
6816 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6817 zone_names
[j
], memmap_pages
, freesize
);
6820 /* Account for reserved pages */
6821 if (j
== 0 && freesize
> dma_reserve
) {
6822 freesize
-= dma_reserve
;
6823 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6824 zone_names
[0], dma_reserve
);
6827 if (!is_highmem_idx(j
))
6828 nr_kernel_pages
+= freesize
;
6829 /* Charge for highmem memmap if there are enough kernel pages */
6830 else if (nr_kernel_pages
> memmap_pages
* 2)
6831 nr_kernel_pages
-= memmap_pages
;
6832 nr_all_pages
+= freesize
;
6835 * Set an approximate value for lowmem here, it will be adjusted
6836 * when the bootmem allocator frees pages into the buddy system.
6837 * And all highmem pages will be managed by the buddy system.
6839 zone_init_internals(zone
, j
, nid
, freesize
);
6844 set_pageblock_order();
6845 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6846 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6847 memmap_init(size
, nid
, j
, zone_start_pfn
);
6851 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6852 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6854 unsigned long __maybe_unused start
= 0;
6855 unsigned long __maybe_unused offset
= 0;
6857 /* Skip empty nodes */
6858 if (!pgdat
->node_spanned_pages
)
6861 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6862 offset
= pgdat
->node_start_pfn
- start
;
6863 /* ia64 gets its own node_mem_map, before this, without bootmem */
6864 if (!pgdat
->node_mem_map
) {
6865 unsigned long size
, end
;
6869 * The zone's endpoints aren't required to be MAX_ORDER
6870 * aligned but the node_mem_map endpoints must be in order
6871 * for the buddy allocator to function correctly.
6873 end
= pgdat_end_pfn(pgdat
);
6874 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6875 size
= (end
- start
) * sizeof(struct page
);
6876 map
= memblock_alloc_node(size
, SMP_CACHE_BYTES
,
6879 panic("Failed to allocate %ld bytes for node %d memory map\n",
6880 size
, pgdat
->node_id
);
6881 pgdat
->node_mem_map
= map
+ offset
;
6883 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6884 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
6885 (unsigned long)pgdat
->node_mem_map
);
6886 #ifndef CONFIG_NEED_MULTIPLE_NODES
6888 * With no DISCONTIG, the global mem_map is just set as node 0's
6890 if (pgdat
== NODE_DATA(0)) {
6891 mem_map
= NODE_DATA(0)->node_mem_map
;
6892 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6898 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
6899 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6901 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6902 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
)
6904 pgdat
->first_deferred_pfn
= ULONG_MAX
;
6907 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
) {}
6910 static void __init
free_area_init_node(int nid
)
6912 pg_data_t
*pgdat
= NODE_DATA(nid
);
6913 unsigned long start_pfn
= 0;
6914 unsigned long end_pfn
= 0;
6916 /* pg_data_t should be reset to zero when it's allocated */
6917 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_highest_zoneidx
);
6919 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6921 pgdat
->node_id
= nid
;
6922 pgdat
->node_start_pfn
= start_pfn
;
6923 pgdat
->per_cpu_nodestats
= NULL
;
6925 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6926 (u64
)start_pfn
<< PAGE_SHIFT
,
6927 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6928 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
);
6930 alloc_node_mem_map(pgdat
);
6931 pgdat_set_deferred_range(pgdat
);
6933 free_area_init_core(pgdat
);
6936 void __init
free_area_init_memoryless_node(int nid
)
6938 free_area_init_node(nid
);
6941 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
6943 * Initialize all valid struct pages in the range [spfn, epfn) and mark them
6944 * PageReserved(). Return the number of struct pages that were initialized.
6946 static u64 __init
init_unavailable_range(unsigned long spfn
, unsigned long epfn
)
6951 for (pfn
= spfn
; pfn
< epfn
; pfn
++) {
6952 if (!pfn_valid(ALIGN_DOWN(pfn
, pageblock_nr_pages
))) {
6953 pfn
= ALIGN_DOWN(pfn
, pageblock_nr_pages
)
6954 + pageblock_nr_pages
- 1;
6958 * Use a fake node/zone (0) for now. Some of these pages
6959 * (in memblock.reserved but not in memblock.memory) will
6960 * get re-initialized via reserve_bootmem_region() later.
6962 __init_single_page(pfn_to_page(pfn
), pfn
, 0, 0);
6963 __SetPageReserved(pfn_to_page(pfn
));
6971 * Only struct pages that are backed by physical memory are zeroed and
6972 * initialized by going through __init_single_page(). But, there are some
6973 * struct pages which are reserved in memblock allocator and their fields
6974 * may be accessed (for example page_to_pfn() on some configuration accesses
6975 * flags). We must explicitly initialize those struct pages.
6977 * This function also addresses a similar issue where struct pages are left
6978 * uninitialized because the physical address range is not covered by
6979 * memblock.memory or memblock.reserved. That could happen when memblock
6980 * layout is manually configured via memmap=, or when the highest physical
6981 * address (max_pfn) does not end on a section boundary.
6983 static void __init
init_unavailable_mem(void)
6985 phys_addr_t start
, end
;
6987 phys_addr_t next
= 0;
6990 * Loop through unavailable ranges not covered by memblock.memory.
6993 for_each_mem_range(i
, &start
, &end
) {
6995 pgcnt
+= init_unavailable_range(PFN_DOWN(next
),
7001 * Early sections always have a fully populated memmap for the whole
7002 * section - see pfn_valid(). If the last section has holes at the
7003 * end and that section is marked "online", the memmap will be
7004 * considered initialized. Make sure that memmap has a well defined
7007 pgcnt
+= init_unavailable_range(PFN_DOWN(next
),
7008 round_up(max_pfn
, PAGES_PER_SECTION
));
7011 * Struct pages that do not have backing memory. This could be because
7012 * firmware is using some of this memory, or for some other reasons.
7015 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt
);
7018 static inline void __init
init_unavailable_mem(void)
7021 #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
7023 #if MAX_NUMNODES > 1
7025 * Figure out the number of possible node ids.
7027 void __init
setup_nr_node_ids(void)
7029 unsigned int highest
;
7031 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
7032 nr_node_ids
= highest
+ 1;
7037 * node_map_pfn_alignment - determine the maximum internode alignment
7039 * This function should be called after node map is populated and sorted.
7040 * It calculates the maximum power of two alignment which can distinguish
7043 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7044 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7045 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7046 * shifted, 1GiB is enough and this function will indicate so.
7048 * This is used to test whether pfn -> nid mapping of the chosen memory
7049 * model has fine enough granularity to avoid incorrect mapping for the
7050 * populated node map.
7052 * Return: the determined alignment in pfn's. 0 if there is no alignment
7053 * requirement (single node).
7055 unsigned long __init
node_map_pfn_alignment(void)
7057 unsigned long accl_mask
= 0, last_end
= 0;
7058 unsigned long start
, end
, mask
;
7059 int last_nid
= NUMA_NO_NODE
;
7062 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
7063 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
7070 * Start with a mask granular enough to pin-point to the
7071 * start pfn and tick off bits one-by-one until it becomes
7072 * too coarse to separate the current node from the last.
7074 mask
= ~((1 << __ffs(start
)) - 1);
7075 while (mask
&& last_end
<= (start
& (mask
<< 1)))
7078 /* accumulate all internode masks */
7082 /* convert mask to number of pages */
7083 return ~accl_mask
+ 1;
7087 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7089 * Return: the minimum PFN based on information provided via
7090 * memblock_set_node().
7092 unsigned long __init
find_min_pfn_with_active_regions(void)
7094 return PHYS_PFN(memblock_start_of_DRAM());
7098 * early_calculate_totalpages()
7099 * Sum pages in active regions for movable zone.
7100 * Populate N_MEMORY for calculating usable_nodes.
7102 static unsigned long __init
early_calculate_totalpages(void)
7104 unsigned long totalpages
= 0;
7105 unsigned long start_pfn
, end_pfn
;
7108 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7109 unsigned long pages
= end_pfn
- start_pfn
;
7111 totalpages
+= pages
;
7113 node_set_state(nid
, N_MEMORY
);
7119 * Find the PFN the Movable zone begins in each node. Kernel memory
7120 * is spread evenly between nodes as long as the nodes have enough
7121 * memory. When they don't, some nodes will have more kernelcore than
7124 static void __init
find_zone_movable_pfns_for_nodes(void)
7127 unsigned long usable_startpfn
;
7128 unsigned long kernelcore_node
, kernelcore_remaining
;
7129 /* save the state before borrow the nodemask */
7130 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
7131 unsigned long totalpages
= early_calculate_totalpages();
7132 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
7133 struct memblock_region
*r
;
7135 /* Need to find movable_zone earlier when movable_node is specified. */
7136 find_usable_zone_for_movable();
7139 * If movable_node is specified, ignore kernelcore and movablecore
7142 if (movable_node_is_enabled()) {
7143 for_each_mem_region(r
) {
7144 if (!memblock_is_hotpluggable(r
))
7147 nid
= memblock_get_region_node(r
);
7149 usable_startpfn
= PFN_DOWN(r
->base
);
7150 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7151 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7159 * If kernelcore=mirror is specified, ignore movablecore option
7161 if (mirrored_kernelcore
) {
7162 bool mem_below_4gb_not_mirrored
= false;
7164 for_each_mem_region(r
) {
7165 if (memblock_is_mirror(r
))
7168 nid
= memblock_get_region_node(r
);
7170 usable_startpfn
= memblock_region_memory_base_pfn(r
);
7172 if (usable_startpfn
< 0x100000) {
7173 mem_below_4gb_not_mirrored
= true;
7177 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7178 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7182 if (mem_below_4gb_not_mirrored
)
7183 pr_warn("This configuration results in unmirrored kernel memory.\n");
7189 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7190 * amount of necessary memory.
7192 if (required_kernelcore_percent
)
7193 required_kernelcore
= (totalpages
* 100 * required_kernelcore_percent
) /
7195 if (required_movablecore_percent
)
7196 required_movablecore
= (totalpages
* 100 * required_movablecore_percent
) /
7200 * If movablecore= was specified, calculate what size of
7201 * kernelcore that corresponds so that memory usable for
7202 * any allocation type is evenly spread. If both kernelcore
7203 * and movablecore are specified, then the value of kernelcore
7204 * will be used for required_kernelcore if it's greater than
7205 * what movablecore would have allowed.
7207 if (required_movablecore
) {
7208 unsigned long corepages
;
7211 * Round-up so that ZONE_MOVABLE is at least as large as what
7212 * was requested by the user
7214 required_movablecore
=
7215 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
7216 required_movablecore
= min(totalpages
, required_movablecore
);
7217 corepages
= totalpages
- required_movablecore
;
7219 required_kernelcore
= max(required_kernelcore
, corepages
);
7223 * If kernelcore was not specified or kernelcore size is larger
7224 * than totalpages, there is no ZONE_MOVABLE.
7226 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
7229 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7230 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
7233 /* Spread kernelcore memory as evenly as possible throughout nodes */
7234 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7235 for_each_node_state(nid
, N_MEMORY
) {
7236 unsigned long start_pfn
, end_pfn
;
7239 * Recalculate kernelcore_node if the division per node
7240 * now exceeds what is necessary to satisfy the requested
7241 * amount of memory for the kernel
7243 if (required_kernelcore
< kernelcore_node
)
7244 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7247 * As the map is walked, we track how much memory is usable
7248 * by the kernel using kernelcore_remaining. When it is
7249 * 0, the rest of the node is usable by ZONE_MOVABLE
7251 kernelcore_remaining
= kernelcore_node
;
7253 /* Go through each range of PFNs within this node */
7254 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
7255 unsigned long size_pages
;
7257 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
7258 if (start_pfn
>= end_pfn
)
7261 /* Account for what is only usable for kernelcore */
7262 if (start_pfn
< usable_startpfn
) {
7263 unsigned long kernel_pages
;
7264 kernel_pages
= min(end_pfn
, usable_startpfn
)
7267 kernelcore_remaining
-= min(kernel_pages
,
7268 kernelcore_remaining
);
7269 required_kernelcore
-= min(kernel_pages
,
7270 required_kernelcore
);
7272 /* Continue if range is now fully accounted */
7273 if (end_pfn
<= usable_startpfn
) {
7276 * Push zone_movable_pfn to the end so
7277 * that if we have to rebalance
7278 * kernelcore across nodes, we will
7279 * not double account here
7281 zone_movable_pfn
[nid
] = end_pfn
;
7284 start_pfn
= usable_startpfn
;
7288 * The usable PFN range for ZONE_MOVABLE is from
7289 * start_pfn->end_pfn. Calculate size_pages as the
7290 * number of pages used as kernelcore
7292 size_pages
= end_pfn
- start_pfn
;
7293 if (size_pages
> kernelcore_remaining
)
7294 size_pages
= kernelcore_remaining
;
7295 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
7298 * Some kernelcore has been met, update counts and
7299 * break if the kernelcore for this node has been
7302 required_kernelcore
-= min(required_kernelcore
,
7304 kernelcore_remaining
-= size_pages
;
7305 if (!kernelcore_remaining
)
7311 * If there is still required_kernelcore, we do another pass with one
7312 * less node in the count. This will push zone_movable_pfn[nid] further
7313 * along on the nodes that still have memory until kernelcore is
7317 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
7321 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7322 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
7323 zone_movable_pfn
[nid
] =
7324 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
7327 /* restore the node_state */
7328 node_states
[N_MEMORY
] = saved_node_state
;
7331 /* Any regular or high memory on that node ? */
7332 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
7334 enum zone_type zone_type
;
7336 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
7337 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
7338 if (populated_zone(zone
)) {
7339 if (IS_ENABLED(CONFIG_HIGHMEM
))
7340 node_set_state(nid
, N_HIGH_MEMORY
);
7341 if (zone_type
<= ZONE_NORMAL
)
7342 node_set_state(nid
, N_NORMAL_MEMORY
);
7349 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7350 * such cases we allow max_zone_pfn sorted in the descending order
7352 bool __weak
arch_has_descending_max_zone_pfns(void)
7358 * free_area_init - Initialise all pg_data_t and zone data
7359 * @max_zone_pfn: an array of max PFNs for each zone
7361 * This will call free_area_init_node() for each active node in the system.
7362 * Using the page ranges provided by memblock_set_node(), the size of each
7363 * zone in each node and their holes is calculated. If the maximum PFN
7364 * between two adjacent zones match, it is assumed that the zone is empty.
7365 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7366 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7367 * starts where the previous one ended. For example, ZONE_DMA32 starts
7368 * at arch_max_dma_pfn.
7370 void __init
free_area_init(unsigned long *max_zone_pfn
)
7372 unsigned long start_pfn
, end_pfn
;
7376 /* Record where the zone boundaries are */
7377 memset(arch_zone_lowest_possible_pfn
, 0,
7378 sizeof(arch_zone_lowest_possible_pfn
));
7379 memset(arch_zone_highest_possible_pfn
, 0,
7380 sizeof(arch_zone_highest_possible_pfn
));
7382 start_pfn
= find_min_pfn_with_active_regions();
7383 descending
= arch_has_descending_max_zone_pfns();
7385 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7387 zone
= MAX_NR_ZONES
- i
- 1;
7391 if (zone
== ZONE_MOVABLE
)
7394 end_pfn
= max(max_zone_pfn
[zone
], start_pfn
);
7395 arch_zone_lowest_possible_pfn
[zone
] = start_pfn
;
7396 arch_zone_highest_possible_pfn
[zone
] = end_pfn
;
7398 start_pfn
= end_pfn
;
7401 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7402 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
7403 find_zone_movable_pfns_for_nodes();
7405 /* Print out the zone ranges */
7406 pr_info("Zone ranges:\n");
7407 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7408 if (i
== ZONE_MOVABLE
)
7410 pr_info(" %-8s ", zone_names
[i
]);
7411 if (arch_zone_lowest_possible_pfn
[i
] ==
7412 arch_zone_highest_possible_pfn
[i
])
7415 pr_cont("[mem %#018Lx-%#018Lx]\n",
7416 (u64
)arch_zone_lowest_possible_pfn
[i
]
7418 ((u64
)arch_zone_highest_possible_pfn
[i
]
7419 << PAGE_SHIFT
) - 1);
7422 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7423 pr_info("Movable zone start for each node\n");
7424 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
7425 if (zone_movable_pfn
[i
])
7426 pr_info(" Node %d: %#018Lx\n", i
,
7427 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
7431 * Print out the early node map, and initialize the
7432 * subsection-map relative to active online memory ranges to
7433 * enable future "sub-section" extensions of the memory map.
7435 pr_info("Early memory node ranges\n");
7436 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7437 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
7438 (u64
)start_pfn
<< PAGE_SHIFT
,
7439 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
7440 subsection_map_init(start_pfn
, end_pfn
- start_pfn
);
7443 /* Initialise every node */
7444 mminit_verify_pageflags_layout();
7445 setup_nr_node_ids();
7446 init_unavailable_mem();
7447 for_each_online_node(nid
) {
7448 pg_data_t
*pgdat
= NODE_DATA(nid
);
7449 free_area_init_node(nid
);
7451 /* Any memory on that node */
7452 if (pgdat
->node_present_pages
)
7453 node_set_state(nid
, N_MEMORY
);
7454 check_for_memory(pgdat
, nid
);
7458 static int __init
cmdline_parse_core(char *p
, unsigned long *core
,
7459 unsigned long *percent
)
7461 unsigned long long coremem
;
7467 /* Value may be a percentage of total memory, otherwise bytes */
7468 coremem
= simple_strtoull(p
, &endptr
, 0);
7469 if (*endptr
== '%') {
7470 /* Paranoid check for percent values greater than 100 */
7471 WARN_ON(coremem
> 100);
7475 coremem
= memparse(p
, &p
);
7476 /* Paranoid check that UL is enough for the coremem value */
7477 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
7479 *core
= coremem
>> PAGE_SHIFT
;
7486 * kernelcore=size sets the amount of memory for use for allocations that
7487 * cannot be reclaimed or migrated.
7489 static int __init
cmdline_parse_kernelcore(char *p
)
7491 /* parse kernelcore=mirror */
7492 if (parse_option_str(p
, "mirror")) {
7493 mirrored_kernelcore
= true;
7497 return cmdline_parse_core(p
, &required_kernelcore
,
7498 &required_kernelcore_percent
);
7502 * movablecore=size sets the amount of memory for use for allocations that
7503 * can be reclaimed or migrated.
7505 static int __init
cmdline_parse_movablecore(char *p
)
7507 return cmdline_parse_core(p
, &required_movablecore
,
7508 &required_movablecore_percent
);
7511 early_param("kernelcore", cmdline_parse_kernelcore
);
7512 early_param("movablecore", cmdline_parse_movablecore
);
7514 void adjust_managed_page_count(struct page
*page
, long count
)
7516 atomic_long_add(count
, &page_zone(page
)->managed_pages
);
7517 totalram_pages_add(count
);
7518 #ifdef CONFIG_HIGHMEM
7519 if (PageHighMem(page
))
7520 totalhigh_pages_add(count
);
7523 EXPORT_SYMBOL(adjust_managed_page_count
);
7525 unsigned long free_reserved_area(void *start
, void *end
, int poison
, const char *s
)
7528 unsigned long pages
= 0;
7530 start
= (void *)PAGE_ALIGN((unsigned long)start
);
7531 end
= (void *)((unsigned long)end
& PAGE_MASK
);
7532 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
7533 struct page
*page
= virt_to_page(pos
);
7534 void *direct_map_addr
;
7537 * 'direct_map_addr' might be different from 'pos'
7538 * because some architectures' virt_to_page()
7539 * work with aliases. Getting the direct map
7540 * address ensures that we get a _writeable_
7541 * alias for the memset().
7543 direct_map_addr
= page_address(page
);
7544 if ((unsigned int)poison
<= 0xFF)
7545 memset(direct_map_addr
, poison
, PAGE_SIZE
);
7547 free_reserved_page(page
);
7551 pr_info("Freeing %s memory: %ldK\n",
7552 s
, pages
<< (PAGE_SHIFT
- 10));
7557 #ifdef CONFIG_HIGHMEM
7558 void free_highmem_page(struct page
*page
)
7560 __free_reserved_page(page
);
7561 totalram_pages_inc();
7562 atomic_long_inc(&page_zone(page
)->managed_pages
);
7563 totalhigh_pages_inc();
7568 void __init
mem_init_print_info(const char *str
)
7570 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
7571 unsigned long init_code_size
, init_data_size
;
7573 physpages
= get_num_physpages();
7574 codesize
= _etext
- _stext
;
7575 datasize
= _edata
- _sdata
;
7576 rosize
= __end_rodata
- __start_rodata
;
7577 bss_size
= __bss_stop
- __bss_start
;
7578 init_data_size
= __init_end
- __init_begin
;
7579 init_code_size
= _einittext
- _sinittext
;
7582 * Detect special cases and adjust section sizes accordingly:
7583 * 1) .init.* may be embedded into .data sections
7584 * 2) .init.text.* may be out of [__init_begin, __init_end],
7585 * please refer to arch/tile/kernel/vmlinux.lds.S.
7586 * 3) .rodata.* may be embedded into .text or .data sections.
7588 #define adj_init_size(start, end, size, pos, adj) \
7590 if (start <= pos && pos < end && size > adj) \
7594 adj_init_size(__init_begin
, __init_end
, init_data_size
,
7595 _sinittext
, init_code_size
);
7596 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
7597 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
7598 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
7599 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
7601 #undef adj_init_size
7603 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7604 #ifdef CONFIG_HIGHMEM
7608 nr_free_pages() << (PAGE_SHIFT
- 10),
7609 physpages
<< (PAGE_SHIFT
- 10),
7610 codesize
>> 10, datasize
>> 10, rosize
>> 10,
7611 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
7612 (physpages
- totalram_pages() - totalcma_pages
) << (PAGE_SHIFT
- 10),
7613 totalcma_pages
<< (PAGE_SHIFT
- 10),
7614 #ifdef CONFIG_HIGHMEM
7615 totalhigh_pages() << (PAGE_SHIFT
- 10),
7617 str
? ", " : "", str
? str
: "");
7621 * set_dma_reserve - set the specified number of pages reserved in the first zone
7622 * @new_dma_reserve: The number of pages to mark reserved
7624 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7625 * In the DMA zone, a significant percentage may be consumed by kernel image
7626 * and other unfreeable allocations which can skew the watermarks badly. This
7627 * function may optionally be used to account for unfreeable pages in the
7628 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7629 * smaller per-cpu batchsize.
7631 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
7633 dma_reserve
= new_dma_reserve
;
7636 static int page_alloc_cpu_dead(unsigned int cpu
)
7639 lru_add_drain_cpu(cpu
);
7643 * Spill the event counters of the dead processor
7644 * into the current processors event counters.
7645 * This artificially elevates the count of the current
7648 vm_events_fold_cpu(cpu
);
7651 * Zero the differential counters of the dead processor
7652 * so that the vm statistics are consistent.
7654 * This is only okay since the processor is dead and cannot
7655 * race with what we are doing.
7657 cpu_vm_stats_fold(cpu
);
7662 int hashdist
= HASHDIST_DEFAULT
;
7664 static int __init
set_hashdist(char *str
)
7668 hashdist
= simple_strtoul(str
, &str
, 0);
7671 __setup("hashdist=", set_hashdist
);
7674 void __init
page_alloc_init(void)
7679 if (num_node_state(N_MEMORY
) == 1)
7683 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
7684 "mm/page_alloc:dead", NULL
,
7685 page_alloc_cpu_dead
);
7690 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7691 * or min_free_kbytes changes.
7693 static void calculate_totalreserve_pages(void)
7695 struct pglist_data
*pgdat
;
7696 unsigned long reserve_pages
= 0;
7697 enum zone_type i
, j
;
7699 for_each_online_pgdat(pgdat
) {
7701 pgdat
->totalreserve_pages
= 0;
7703 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7704 struct zone
*zone
= pgdat
->node_zones
+ i
;
7706 unsigned long managed_pages
= zone_managed_pages(zone
);
7708 /* Find valid and maximum lowmem_reserve in the zone */
7709 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
7710 if (zone
->lowmem_reserve
[j
] > max
)
7711 max
= zone
->lowmem_reserve
[j
];
7714 /* we treat the high watermark as reserved pages. */
7715 max
+= high_wmark_pages(zone
);
7717 if (max
> managed_pages
)
7718 max
= managed_pages
;
7720 pgdat
->totalreserve_pages
+= max
;
7722 reserve_pages
+= max
;
7725 totalreserve_pages
= reserve_pages
;
7729 * setup_per_zone_lowmem_reserve - called whenever
7730 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7731 * has a correct pages reserved value, so an adequate number of
7732 * pages are left in the zone after a successful __alloc_pages().
7734 static void setup_per_zone_lowmem_reserve(void)
7736 struct pglist_data
*pgdat
;
7737 enum zone_type j
, idx
;
7739 for_each_online_pgdat(pgdat
) {
7740 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
7741 struct zone
*zone
= pgdat
->node_zones
+ j
;
7742 unsigned long managed_pages
= zone_managed_pages(zone
);
7744 zone
->lowmem_reserve
[j
] = 0;
7748 struct zone
*lower_zone
;
7751 lower_zone
= pgdat
->node_zones
+ idx
;
7753 if (!sysctl_lowmem_reserve_ratio
[idx
] ||
7754 !zone_managed_pages(lower_zone
)) {
7755 lower_zone
->lowmem_reserve
[j
] = 0;
7758 lower_zone
->lowmem_reserve
[j
] =
7759 managed_pages
/ sysctl_lowmem_reserve_ratio
[idx
];
7761 managed_pages
+= zone_managed_pages(lower_zone
);
7766 /* update totalreserve_pages */
7767 calculate_totalreserve_pages();
7770 static void __setup_per_zone_wmarks(void)
7772 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
7773 unsigned long lowmem_pages
= 0;
7775 unsigned long flags
;
7777 /* Calculate total number of !ZONE_HIGHMEM pages */
7778 for_each_zone(zone
) {
7779 if (!is_highmem(zone
))
7780 lowmem_pages
+= zone_managed_pages(zone
);
7783 for_each_zone(zone
) {
7786 spin_lock_irqsave(&zone
->lock
, flags
);
7787 tmp
= (u64
)pages_min
* zone_managed_pages(zone
);
7788 do_div(tmp
, lowmem_pages
);
7789 if (is_highmem(zone
)) {
7791 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7792 * need highmem pages, so cap pages_min to a small
7795 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7796 * deltas control async page reclaim, and so should
7797 * not be capped for highmem.
7799 unsigned long min_pages
;
7801 min_pages
= zone_managed_pages(zone
) / 1024;
7802 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7803 zone
->_watermark
[WMARK_MIN
] = min_pages
;
7806 * If it's a lowmem zone, reserve a number of pages
7807 * proportionate to the zone's size.
7809 zone
->_watermark
[WMARK_MIN
] = tmp
;
7813 * Set the kswapd watermarks distance according to the
7814 * scale factor in proportion to available memory, but
7815 * ensure a minimum size on small systems.
7817 tmp
= max_t(u64
, tmp
>> 2,
7818 mult_frac(zone_managed_pages(zone
),
7819 watermark_scale_factor
, 10000));
7821 zone
->watermark_boost
= 0;
7822 zone
->_watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7823 zone
->_watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7825 spin_unlock_irqrestore(&zone
->lock
, flags
);
7828 /* update totalreserve_pages */
7829 calculate_totalreserve_pages();
7833 * setup_per_zone_wmarks - called when min_free_kbytes changes
7834 * or when memory is hot-{added|removed}
7836 * Ensures that the watermark[min,low,high] values for each zone are set
7837 * correctly with respect to min_free_kbytes.
7839 void setup_per_zone_wmarks(void)
7841 static DEFINE_SPINLOCK(lock
);
7844 __setup_per_zone_wmarks();
7849 * Initialise min_free_kbytes.
7851 * For small machines we want it small (128k min). For large machines
7852 * we want it large (256MB max). But it is not linear, because network
7853 * bandwidth does not increase linearly with machine size. We use
7855 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7856 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7872 int __meminit
init_per_zone_wmark_min(void)
7874 unsigned long lowmem_kbytes
;
7875 int new_min_free_kbytes
;
7877 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7878 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7880 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7881 min_free_kbytes
= new_min_free_kbytes
;
7882 if (min_free_kbytes
< 128)
7883 min_free_kbytes
= 128;
7884 if (min_free_kbytes
> 262144)
7885 min_free_kbytes
= 262144;
7887 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7888 new_min_free_kbytes
, user_min_free_kbytes
);
7890 setup_per_zone_wmarks();
7891 refresh_zone_stat_thresholds();
7892 setup_per_zone_lowmem_reserve();
7895 setup_min_unmapped_ratio();
7896 setup_min_slab_ratio();
7899 khugepaged_min_free_kbytes_update();
7903 postcore_initcall(init_per_zone_wmark_min
)
7906 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7907 * that we can call two helper functions whenever min_free_kbytes
7910 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7911 void *buffer
, size_t *length
, loff_t
*ppos
)
7915 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7920 user_min_free_kbytes
= min_free_kbytes
;
7921 setup_per_zone_wmarks();
7926 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7927 void *buffer
, size_t *length
, loff_t
*ppos
)
7931 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7936 setup_per_zone_wmarks();
7942 static void setup_min_unmapped_ratio(void)
7947 for_each_online_pgdat(pgdat
)
7948 pgdat
->min_unmapped_pages
= 0;
7951 zone
->zone_pgdat
->min_unmapped_pages
+= (zone_managed_pages(zone
) *
7952 sysctl_min_unmapped_ratio
) / 100;
7956 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7957 void *buffer
, size_t *length
, loff_t
*ppos
)
7961 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7965 setup_min_unmapped_ratio();
7970 static void setup_min_slab_ratio(void)
7975 for_each_online_pgdat(pgdat
)
7976 pgdat
->min_slab_pages
= 0;
7979 zone
->zone_pgdat
->min_slab_pages
+= (zone_managed_pages(zone
) *
7980 sysctl_min_slab_ratio
) / 100;
7983 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7984 void *buffer
, size_t *length
, loff_t
*ppos
)
7988 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7992 setup_min_slab_ratio();
7999 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8000 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8001 * whenever sysctl_lowmem_reserve_ratio changes.
8003 * The reserve ratio obviously has absolutely no relation with the
8004 * minimum watermarks. The lowmem reserve ratio can only make sense
8005 * if in function of the boot time zone sizes.
8007 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8008 void *buffer
, size_t *length
, loff_t
*ppos
)
8012 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8014 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
8015 if (sysctl_lowmem_reserve_ratio
[i
] < 1)
8016 sysctl_lowmem_reserve_ratio
[i
] = 0;
8019 setup_per_zone_lowmem_reserve();
8023 static void __zone_pcp_update(struct zone
*zone
)
8027 for_each_possible_cpu(cpu
)
8028 pageset_set_high_and_batch(zone
,
8029 per_cpu_ptr(zone
->pageset
, cpu
));
8033 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8034 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8035 * pagelist can have before it gets flushed back to buddy allocator.
8037 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
8038 void *buffer
, size_t *length
, loff_t
*ppos
)
8041 int old_percpu_pagelist_fraction
;
8044 mutex_lock(&pcp_batch_high_lock
);
8045 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
8047 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8048 if (!write
|| ret
< 0)
8051 /* Sanity checking to avoid pcp imbalance */
8052 if (percpu_pagelist_fraction
&&
8053 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
8054 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
8060 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
8063 for_each_populated_zone(zone
)
8064 __zone_pcp_update(zone
);
8066 mutex_unlock(&pcp_batch_high_lock
);
8070 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8072 * Returns the number of pages that arch has reserved but
8073 * is not known to alloc_large_system_hash().
8075 static unsigned long __init
arch_reserved_kernel_pages(void)
8082 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8083 * machines. As memory size is increased the scale is also increased but at
8084 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8085 * quadruples the scale is increased by one, which means the size of hash table
8086 * only doubles, instead of quadrupling as well.
8087 * Because 32-bit systems cannot have large physical memory, where this scaling
8088 * makes sense, it is disabled on such platforms.
8090 #if __BITS_PER_LONG > 32
8091 #define ADAPT_SCALE_BASE (64ul << 30)
8092 #define ADAPT_SCALE_SHIFT 2
8093 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8097 * allocate a large system hash table from bootmem
8098 * - it is assumed that the hash table must contain an exact power-of-2
8099 * quantity of entries
8100 * - limit is the number of hash buckets, not the total allocation size
8102 void *__init
alloc_large_system_hash(const char *tablename
,
8103 unsigned long bucketsize
,
8104 unsigned long numentries
,
8107 unsigned int *_hash_shift
,
8108 unsigned int *_hash_mask
,
8109 unsigned long low_limit
,
8110 unsigned long high_limit
)
8112 unsigned long long max
= high_limit
;
8113 unsigned long log2qty
, size
;
8118 /* allow the kernel cmdline to have a say */
8120 /* round applicable memory size up to nearest megabyte */
8121 numentries
= nr_kernel_pages
;
8122 numentries
-= arch_reserved_kernel_pages();
8124 /* It isn't necessary when PAGE_SIZE >= 1MB */
8125 if (PAGE_SHIFT
< 20)
8126 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
8128 #if __BITS_PER_LONG > 32
8130 unsigned long adapt
;
8132 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
8133 adapt
<<= ADAPT_SCALE_SHIFT
)
8138 /* limit to 1 bucket per 2^scale bytes of low memory */
8139 if (scale
> PAGE_SHIFT
)
8140 numentries
>>= (scale
- PAGE_SHIFT
);
8142 numentries
<<= (PAGE_SHIFT
- scale
);
8144 /* Make sure we've got at least a 0-order allocation.. */
8145 if (unlikely(flags
& HASH_SMALL
)) {
8146 /* Makes no sense without HASH_EARLY */
8147 WARN_ON(!(flags
& HASH_EARLY
));
8148 if (!(numentries
>> *_hash_shift
)) {
8149 numentries
= 1UL << *_hash_shift
;
8150 BUG_ON(!numentries
);
8152 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
8153 numentries
= PAGE_SIZE
/ bucketsize
;
8155 numentries
= roundup_pow_of_two(numentries
);
8157 /* limit allocation size to 1/16 total memory by default */
8159 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
8160 do_div(max
, bucketsize
);
8162 max
= min(max
, 0x80000000ULL
);
8164 if (numentries
< low_limit
)
8165 numentries
= low_limit
;
8166 if (numentries
> max
)
8169 log2qty
= ilog2(numentries
);
8171 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
8174 size
= bucketsize
<< log2qty
;
8175 if (flags
& HASH_EARLY
) {
8176 if (flags
& HASH_ZERO
)
8177 table
= memblock_alloc(size
, SMP_CACHE_BYTES
);
8179 table
= memblock_alloc_raw(size
,
8181 } else if (get_order(size
) >= MAX_ORDER
|| hashdist
) {
8182 table
= __vmalloc(size
, gfp_flags
);
8186 * If bucketsize is not a power-of-two, we may free
8187 * some pages at the end of hash table which
8188 * alloc_pages_exact() automatically does
8190 table
= alloc_pages_exact(size
, gfp_flags
);
8191 kmemleak_alloc(table
, size
, 1, gfp_flags
);
8193 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
8196 panic("Failed to allocate %s hash table\n", tablename
);
8198 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8199 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
,
8200 virt
? "vmalloc" : "linear");
8203 *_hash_shift
= log2qty
;
8205 *_hash_mask
= (1 << log2qty
) - 1;
8211 * This function checks whether pageblock includes unmovable pages or not.
8213 * PageLRU check without isolation or lru_lock could race so that
8214 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8215 * check without lock_page also may miss some movable non-lru pages at
8216 * race condition. So you can't expect this function should be exact.
8218 * Returns a page without holding a reference. If the caller wants to
8219 * dereference that page (e.g., dumping), it has to make sure that it
8220 * cannot get removed (e.g., via memory unplug) concurrently.
8223 struct page
*has_unmovable_pages(struct zone
*zone
, struct page
*page
,
8224 int migratetype
, int flags
)
8226 unsigned long iter
= 0;
8227 unsigned long pfn
= page_to_pfn(page
);
8228 unsigned long offset
= pfn
% pageblock_nr_pages
;
8230 if (is_migrate_cma_page(page
)) {
8232 * CMA allocations (alloc_contig_range) really need to mark
8233 * isolate CMA pageblocks even when they are not movable in fact
8234 * so consider them movable here.
8236 if (is_migrate_cma(migratetype
))
8242 for (; iter
< pageblock_nr_pages
- offset
; iter
++) {
8243 if (!pfn_valid_within(pfn
+ iter
))
8246 page
= pfn_to_page(pfn
+ iter
);
8249 * Both, bootmem allocations and memory holes are marked
8250 * PG_reserved and are unmovable. We can even have unmovable
8251 * allocations inside ZONE_MOVABLE, for example when
8252 * specifying "movablecore".
8254 if (PageReserved(page
))
8258 * If the zone is movable and we have ruled out all reserved
8259 * pages then it should be reasonably safe to assume the rest
8262 if (zone_idx(zone
) == ZONE_MOVABLE
)
8266 * Hugepages are not in LRU lists, but they're movable.
8267 * THPs are on the LRU, but need to be counted as #small pages.
8268 * We need not scan over tail pages because we don't
8269 * handle each tail page individually in migration.
8271 if (PageHuge(page
) || PageTransCompound(page
)) {
8272 struct page
*head
= compound_head(page
);
8273 unsigned int skip_pages
;
8275 if (PageHuge(page
)) {
8276 if (!hugepage_migration_supported(page_hstate(head
)))
8278 } else if (!PageLRU(head
) && !__PageMovable(head
)) {
8282 skip_pages
= compound_nr(head
) - (page
- head
);
8283 iter
+= skip_pages
- 1;
8288 * We can't use page_count without pin a page
8289 * because another CPU can free compound page.
8290 * This check already skips compound tails of THP
8291 * because their page->_refcount is zero at all time.
8293 if (!page_ref_count(page
)) {
8294 if (PageBuddy(page
))
8295 iter
+= (1 << page_order(page
)) - 1;
8300 * The HWPoisoned page may be not in buddy system, and
8301 * page_count() is not 0.
8303 if ((flags
& MEMORY_OFFLINE
) && PageHWPoison(page
))
8307 * We treat all PageOffline() pages as movable when offlining
8308 * to give drivers a chance to decrement their reference count
8309 * in MEM_GOING_OFFLINE in order to indicate that these pages
8310 * can be offlined as there are no direct references anymore.
8311 * For actually unmovable PageOffline() where the driver does
8312 * not support this, we will fail later when trying to actually
8313 * move these pages that still have a reference count > 0.
8314 * (false negatives in this function only)
8316 if ((flags
& MEMORY_OFFLINE
) && PageOffline(page
))
8319 if (__PageMovable(page
) || PageLRU(page
))
8323 * If there are RECLAIMABLE pages, we need to check
8324 * it. But now, memory offline itself doesn't call
8325 * shrink_node_slabs() and it still to be fixed.
8332 #ifdef CONFIG_CONTIG_ALLOC
8333 static unsigned long pfn_max_align_down(unsigned long pfn
)
8335 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8336 pageblock_nr_pages
) - 1);
8339 static unsigned long pfn_max_align_up(unsigned long pfn
)
8341 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8342 pageblock_nr_pages
));
8345 /* [start, end) must belong to a single zone. */
8346 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
8347 unsigned long start
, unsigned long end
)
8349 /* This function is based on compact_zone() from compaction.c. */
8350 unsigned int nr_reclaimed
;
8351 unsigned long pfn
= start
;
8352 unsigned int tries
= 0;
8354 struct migration_target_control mtc
= {
8355 .nid
= zone_to_nid(cc
->zone
),
8356 .gfp_mask
= GFP_USER
| __GFP_MOVABLE
| __GFP_RETRY_MAYFAIL
,
8361 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
8362 if (fatal_signal_pending(current
)) {
8367 if (list_empty(&cc
->migratepages
)) {
8368 cc
->nr_migratepages
= 0;
8369 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
8375 } else if (++tries
== 5) {
8376 ret
= ret
< 0 ? ret
: -EBUSY
;
8380 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
8382 cc
->nr_migratepages
-= nr_reclaimed
;
8384 ret
= migrate_pages(&cc
->migratepages
, alloc_migration_target
,
8385 NULL
, (unsigned long)&mtc
, cc
->mode
, MR_CONTIG_RANGE
);
8388 putback_movable_pages(&cc
->migratepages
);
8395 * alloc_contig_range() -- tries to allocate given range of pages
8396 * @start: start PFN to allocate
8397 * @end: one-past-the-last PFN to allocate
8398 * @migratetype: migratetype of the underlaying pageblocks (either
8399 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8400 * in range must have the same migratetype and it must
8401 * be either of the two.
8402 * @gfp_mask: GFP mask to use during compaction
8404 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8405 * aligned. The PFN range must belong to a single zone.
8407 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8408 * pageblocks in the range. Once isolated, the pageblocks should not
8409 * be modified by others.
8411 * Return: zero on success or negative error code. On success all
8412 * pages which PFN is in [start, end) are allocated for the caller and
8413 * need to be freed with free_contig_range().
8415 int alloc_contig_range(unsigned long start
, unsigned long end
,
8416 unsigned migratetype
, gfp_t gfp_mask
)
8418 unsigned long outer_start
, outer_end
;
8422 struct compact_control cc
= {
8423 .nr_migratepages
= 0,
8425 .zone
= page_zone(pfn_to_page(start
)),
8426 .mode
= MIGRATE_SYNC
,
8427 .ignore_skip_hint
= true,
8428 .no_set_skip_hint
= true,
8429 .gfp_mask
= current_gfp_context(gfp_mask
),
8430 .alloc_contig
= true,
8432 INIT_LIST_HEAD(&cc
.migratepages
);
8435 * What we do here is we mark all pageblocks in range as
8436 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8437 * have different sizes, and due to the way page allocator
8438 * work, we align the range to biggest of the two pages so
8439 * that page allocator won't try to merge buddies from
8440 * different pageblocks and change MIGRATE_ISOLATE to some
8441 * other migration type.
8443 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8444 * migrate the pages from an unaligned range (ie. pages that
8445 * we are interested in). This will put all the pages in
8446 * range back to page allocator as MIGRATE_ISOLATE.
8448 * When this is done, we take the pages in range from page
8449 * allocator removing them from the buddy system. This way
8450 * page allocator will never consider using them.
8452 * This lets us mark the pageblocks back as
8453 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8454 * aligned range but not in the unaligned, original range are
8455 * put back to page allocator so that buddy can use them.
8458 ret
= start_isolate_page_range(pfn_max_align_down(start
),
8459 pfn_max_align_up(end
), migratetype
, 0);
8464 * In case of -EBUSY, we'd like to know which page causes problem.
8465 * So, just fall through. test_pages_isolated() has a tracepoint
8466 * which will report the busy page.
8468 * It is possible that busy pages could become available before
8469 * the call to test_pages_isolated, and the range will actually be
8470 * allocated. So, if we fall through be sure to clear ret so that
8471 * -EBUSY is not accidentally used or returned to caller.
8473 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
8474 if (ret
&& ret
!= -EBUSY
)
8479 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8480 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8481 * more, all pages in [start, end) are free in page allocator.
8482 * What we are going to do is to allocate all pages from
8483 * [start, end) (that is remove them from page allocator).
8485 * The only problem is that pages at the beginning and at the
8486 * end of interesting range may be not aligned with pages that
8487 * page allocator holds, ie. they can be part of higher order
8488 * pages. Because of this, we reserve the bigger range and
8489 * once this is done free the pages we are not interested in.
8491 * We don't have to hold zone->lock here because the pages are
8492 * isolated thus they won't get removed from buddy.
8495 lru_add_drain_all();
8498 outer_start
= start
;
8499 while (!PageBuddy(pfn_to_page(outer_start
))) {
8500 if (++order
>= MAX_ORDER
) {
8501 outer_start
= start
;
8504 outer_start
&= ~0UL << order
;
8507 if (outer_start
!= start
) {
8508 order
= page_order(pfn_to_page(outer_start
));
8511 * outer_start page could be small order buddy page and
8512 * it doesn't include start page. Adjust outer_start
8513 * in this case to report failed page properly
8514 * on tracepoint in test_pages_isolated()
8516 if (outer_start
+ (1UL << order
) <= start
)
8517 outer_start
= start
;
8520 /* Make sure the range is really isolated. */
8521 if (test_pages_isolated(outer_start
, end
, 0)) {
8522 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8523 __func__
, outer_start
, end
);
8528 /* Grab isolated pages from freelists. */
8529 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
8535 /* Free head and tail (if any) */
8536 if (start
!= outer_start
)
8537 free_contig_range(outer_start
, start
- outer_start
);
8538 if (end
!= outer_end
)
8539 free_contig_range(end
, outer_end
- end
);
8542 undo_isolate_page_range(pfn_max_align_down(start
),
8543 pfn_max_align_up(end
), migratetype
);
8546 EXPORT_SYMBOL(alloc_contig_range
);
8548 static int __alloc_contig_pages(unsigned long start_pfn
,
8549 unsigned long nr_pages
, gfp_t gfp_mask
)
8551 unsigned long end_pfn
= start_pfn
+ nr_pages
;
8553 return alloc_contig_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
,
8557 static bool pfn_range_valid_contig(struct zone
*z
, unsigned long start_pfn
,
8558 unsigned long nr_pages
)
8560 unsigned long i
, end_pfn
= start_pfn
+ nr_pages
;
8563 for (i
= start_pfn
; i
< end_pfn
; i
++) {
8564 page
= pfn_to_online_page(i
);
8568 if (page_zone(page
) != z
)
8571 if (PageReserved(page
))
8574 if (page_count(page
) > 0)
8583 static bool zone_spans_last_pfn(const struct zone
*zone
,
8584 unsigned long start_pfn
, unsigned long nr_pages
)
8586 unsigned long last_pfn
= start_pfn
+ nr_pages
- 1;
8588 return zone_spans_pfn(zone
, last_pfn
);
8592 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8593 * @nr_pages: Number of contiguous pages to allocate
8594 * @gfp_mask: GFP mask to limit search and used during compaction
8596 * @nodemask: Mask for other possible nodes
8598 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8599 * on an applicable zonelist to find a contiguous pfn range which can then be
8600 * tried for allocation with alloc_contig_range(). This routine is intended
8601 * for allocation requests which can not be fulfilled with the buddy allocator.
8603 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8604 * power of two then the alignment is guaranteed to be to the given nr_pages
8605 * (e.g. 1GB request would be aligned to 1GB).
8607 * Allocated pages can be freed with free_contig_range() or by manually calling
8608 * __free_page() on each allocated page.
8610 * Return: pointer to contiguous pages on success, or NULL if not successful.
8612 struct page
*alloc_contig_pages(unsigned long nr_pages
, gfp_t gfp_mask
,
8613 int nid
, nodemask_t
*nodemask
)
8615 unsigned long ret
, pfn
, flags
;
8616 struct zonelist
*zonelist
;
8620 zonelist
= node_zonelist(nid
, gfp_mask
);
8621 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
8622 gfp_zone(gfp_mask
), nodemask
) {
8623 spin_lock_irqsave(&zone
->lock
, flags
);
8625 pfn
= ALIGN(zone
->zone_start_pfn
, nr_pages
);
8626 while (zone_spans_last_pfn(zone
, pfn
, nr_pages
)) {
8627 if (pfn_range_valid_contig(zone
, pfn
, nr_pages
)) {
8629 * We release the zone lock here because
8630 * alloc_contig_range() will also lock the zone
8631 * at some point. If there's an allocation
8632 * spinning on this lock, it may win the race
8633 * and cause alloc_contig_range() to fail...
8635 spin_unlock_irqrestore(&zone
->lock
, flags
);
8636 ret
= __alloc_contig_pages(pfn
, nr_pages
,
8639 return pfn_to_page(pfn
);
8640 spin_lock_irqsave(&zone
->lock
, flags
);
8644 spin_unlock_irqrestore(&zone
->lock
, flags
);
8648 #endif /* CONFIG_CONTIG_ALLOC */
8650 void free_contig_range(unsigned long pfn
, unsigned int nr_pages
)
8652 unsigned int count
= 0;
8654 for (; nr_pages
--; pfn
++) {
8655 struct page
*page
= pfn_to_page(pfn
);
8657 count
+= page_count(page
) != 1;
8660 WARN(count
!= 0, "%d pages are still in use!\n", count
);
8662 EXPORT_SYMBOL(free_contig_range
);
8665 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8666 * page high values need to be recalulated.
8668 void __meminit
zone_pcp_update(struct zone
*zone
)
8670 mutex_lock(&pcp_batch_high_lock
);
8671 __zone_pcp_update(zone
);
8672 mutex_unlock(&pcp_batch_high_lock
);
8675 void zone_pcp_reset(struct zone
*zone
)
8677 unsigned long flags
;
8679 struct per_cpu_pageset
*pset
;
8681 /* avoid races with drain_pages() */
8682 local_irq_save(flags
);
8683 if (zone
->pageset
!= &boot_pageset
) {
8684 for_each_online_cpu(cpu
) {
8685 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
8686 drain_zonestat(zone
, pset
);
8688 free_percpu(zone
->pageset
);
8689 zone
->pageset
= &boot_pageset
;
8691 local_irq_restore(flags
);
8694 #ifdef CONFIG_MEMORY_HOTREMOVE
8696 * All pages in the range must be in a single zone and isolated
8697 * before calling this.
8700 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
8706 unsigned long flags
;
8707 unsigned long offlined_pages
= 0;
8709 /* find the first valid pfn */
8710 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
8714 return offlined_pages
;
8716 offline_mem_sections(pfn
, end_pfn
);
8717 zone
= page_zone(pfn_to_page(pfn
));
8718 spin_lock_irqsave(&zone
->lock
, flags
);
8720 while (pfn
< end_pfn
) {
8721 if (!pfn_valid(pfn
)) {
8725 page
= pfn_to_page(pfn
);
8727 * The HWPoisoned page may be not in buddy system, and
8728 * page_count() is not 0.
8730 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
8736 * At this point all remaining PageOffline() pages have a
8737 * reference count of 0 and can simply be skipped.
8739 if (PageOffline(page
)) {
8740 BUG_ON(page_count(page
));
8741 BUG_ON(PageBuddy(page
));
8747 BUG_ON(page_count(page
));
8748 BUG_ON(!PageBuddy(page
));
8749 order
= page_order(page
);
8750 offlined_pages
+= 1 << order
;
8751 del_page_from_free_list(page
, zone
, order
);
8752 pfn
+= (1 << order
);
8754 spin_unlock_irqrestore(&zone
->lock
, flags
);
8756 return offlined_pages
;
8760 bool is_free_buddy_page(struct page
*page
)
8762 struct zone
*zone
= page_zone(page
);
8763 unsigned long pfn
= page_to_pfn(page
);
8764 unsigned long flags
;
8767 spin_lock_irqsave(&zone
->lock
, flags
);
8768 for (order
= 0; order
< MAX_ORDER
; order
++) {
8769 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8771 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
8774 spin_unlock_irqrestore(&zone
->lock
, flags
);
8776 return order
< MAX_ORDER
;
8779 #ifdef CONFIG_MEMORY_FAILURE
8781 * Set PG_hwpoison flag if a given page is confirmed to be a free page. This
8782 * test is performed under the zone lock to prevent a race against page
8785 bool set_hwpoison_free_buddy_page(struct page
*page
)
8787 struct zone
*zone
= page_zone(page
);
8788 unsigned long pfn
= page_to_pfn(page
);
8789 unsigned long flags
;
8791 bool hwpoisoned
= false;
8793 spin_lock_irqsave(&zone
->lock
, flags
);
8794 for (order
= 0; order
< MAX_ORDER
; order
++) {
8795 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8797 if (PageBuddy(page_head
) && page_order(page_head
) >= order
) {
8798 if (!TestSetPageHWPoison(page
))
8803 spin_unlock_irqrestore(&zone
->lock
, flags
);